Abstract: Natural fibres have been used to reinforce materials for over 3,000 years. More recently they have been employed in combination with plastics. Many types of natural fibres have been investigated for use in plastics including coir, luffa, flax, hemp, jute, sisal, and banana. Natural fibres have the advantage that they are renewable resources and have marketing appeal. These agricultural wastes can be used to prepare fibre reinforced polypropylene composites for commercial use. Application of composite materials to structures has presented the need for the engineering analysis the present work focuses on the fabrication of polymer matrix composites by using natural fibres like coir, and luffa which are abundant nature in desired shapes by the help of various structures of patterns and calculating its material characteristics (tensile strength, flexural modulus, flexural rigidity, hardness number,% gain of water) by conducting tests like tensile test, flexural test, hardness test, water absorption test, impact test, density test, SEM analysis and their results are measured on sections of the material and make use of the natural fibre reinforced polypropylene composite material for automotive seat shell manufacturing.
Keywords: Natural Fibres, Polypropylene, Tensile Strength, Flexural Test, Hardness Test, Water Absorption Test, Density Test, Impact Test, SEM.


This system of trails offers excellent variety for the novice skier. There are warm-up shelters at Willow Creek group use area and at the trailhead. The trail system is accessible via Murray Hill Road (1 km west of Hwy. 41 about 7 km south of Elkwater Lake.


text:
Martin Eliasson, född 1987, är en svensk skådespelare. Eliasson är utbildad vid Teaterhögskolan i Stockholm 2007–2010.

Filmografi

Teater

Roller (ej komplett)

Referenser

Externa länkar

Svenska skådespelare
Män
Födda 1987
Levande personer

redpajama_set_name: RedPajamaWikipedia


In 2005, a group of Episcopal Church members visited a remote community located quite literally "at the end of the road" in eastern Zambia.
They found people suffering and dying from malaria because they had no understanding of malaria prevention and no access to nets and effective treatment.
Realizing these communities were beyond the reach of the national health system, the group was inspired by the idea of using the church to teach malaria prevention and deliver nets in the isolated communities it served.


text:
\section{Introduction}
An understanding of the hydrodynamics of a quasi-2D fluid interface coupled to a bulk 3D subphase is crucial to modeling the dynamics of a wide variety of biological systems such as lipid membranes~(\cite{StoneMcConnell1995}), bacterial biofilms~(\cite{Petroff_etal2005}), and algae colonies~(\cite{Drescher_etal2009}). One notable theoretical and experimental study of such a system was conducted by~\cite{Alexander_etal2006}, who examined the tension-driven closing of a cavity punctured in a PDMS monolayer situated on a flat water-air interface.
The authors derived an analytical solution for the axisymmetric fluid motion, predicting that the area of the cavity closes at a fixed rate that depends only on the ratio of monolayer line tension to bulk viscosity; by fitting experimental data in a linear regime of the area vs. time plot, they obtained an estimate for the line tension. The same authors later reapplied this model along with improved experimental methods to obtain a more accurate value for the monolayer line tension, which they reported to be $0.69\pm 0.02$ pN in~\cite{Zou_etal2010}.

The reduction of this problem to the fitting of a single parameter hinges on a crucial assumption: the monolayer viscosity is vanishingly small. While there is experimental evidence supporting the claim that the film dynamics is dominated by subphase viscosity rather than monolayer viscosity~(\cite{Mann_etal1995}), and while there are strongly linear regimes in the experimental area vs. time data in both~\cite{Alexander_etal2006} and~\cite{Zou_etal2010}, the data as a whole is visibly nonlinear, especially at later times when the hole size is small. This indicates that the inviscid assumption may not hold as well as previously thought and that viscous effects of the monolayer may be playing a role in the closure process.

Here we revisit the theoretical model proposed by~\cite{Alexander_etal2006} and amend it by considering the effects of a regularizing monolayer viscosity. This simple change preserves much of the structure of the problem but introduces some notable differences. We find that while the bulk equations are unchanged in the axisymmetric case, the boundary conditions can depend strongly on this monolayer viscosity, especially in regimes where the cavity radius is small relative to the Saffman-Delbr\"uck length--that is, the ratio of the 2D monolayer and 3D bulk viscosities.
In this regime, the predicted dependence of cavity area on time becomes noticeably nonlinear,
which impacts the fitting of experimental data and consequently suggests that these previous studies have underestimated the edge tension by roughly one order of magnitude.

\section{Summary of the original model}

We begin by reviewing the system description given in~\cite{Alexander_etal2006}. Consider a molecularly thin (so essentially two-dimensional) fluid monolayer situated on a three-dimensional half-space of Stokes fluid with flow field $\boldsymbol{u}$ and viscosity $\mu$.  The domain of the monolayer is taken to be the annulus centered at the origin in the $z=0$ plane, $\mathcal{D} = \{(r,0): 0< R_i< r < R_o\}$, where $R_o$ can be infinite. The interface is assumed to be planar for all times, and the flow field of the interface, $\boldsymbol{U} = \boldsymbol{u}(z=0)$, is assumed to have no $z$-component. If the monolayer is 2D incompressible, then the radial component of $\boldsymbol{U}$, which we denote by  $U(r)$, satisfies
\begin{equation}
    \frac{1}{r}\frac{\mathrm{d}}{\mathrm{d}r} (rU)= 0
    \label{divUeqn}
\end{equation}
so that it necessarily has the form
\begin{equation}
U(r) = \frac{F}{r}
\label{Ueqn}
\end{equation}
for some constant $F$ when $R_i <r <R_o$. In the absence of tangential stresses, the tangential component of $\boldsymbol{U}$ vanishes.

In deriving the momentum equation,~\cite{Alexander_etal2006} employ the so-called ``hydrostatic approximation'': the monolayer viscosity is so small that the film may be treated as inviscid. Hence, it is simply the pressure gradient that balances the shear forces from the fluid subphase where it is in contact with the monolayer. Elsewhere, a stress-free interface is assumed:
\begin{equation}
\left.\mu \frac{\partial u}{\partial z}\right|_{z=0} = 0\text{ , } 0<r<R_i
\label{momeqn1}
\end{equation}
\begin{equation}
\left.\mu \frac{\partial u}{\partial z}\right|_{z=0} = -\frac{\mathrm{d}P}{\mathrm{d}r}\text{ , } R_i<r<R_o
\label{momeqn2}
\end{equation}
\begin{equation}
\left.\mu \frac{\partial u}{\partial z}\right|_{z=0} = 0\text{ , } r>R_o
\label{momeqn3}
\end{equation}
where $u$ is the radial component of $\boldsymbol{u}$ and $P$ is the 2D pressure inside of the monolayer. Using standard Hankel transform methods, an equivalent set of triple integral equations can be derived:
\begin{equation}
\int_0^\infty \mathrm{d}k~ k b(k) J_1(kr) = 0\text{ , } 0<r<R_i
\label{tie1}
\end{equation}
\begin{equation}
\int_0^\infty \mathrm{d}k~ b(k) J_1(kr) =  \frac{\mu F}{r} \text{, }R_i<r<R_o
\label{tie2}
\end{equation}
\begin{equation}
\int_0^\infty \mathrm{d}k~ k b(k) J_1(kr) = 0\text{ , } r>R_o
\label{tie3}
\end{equation}
where we have defined $k$ to be the wavenumber and
\begin{equation}
b(k) = \int_0^\infty \mathrm{d}r~ r  \mu \frac{\partial u}{\partial z}(r,z=0) J_1(kr).
\label{bdef}
\end{equation}

The problem is then closed by enforcing the boundary conditions of normal stress balance. In this case, these are simply  the Young-Laplace relations
\begin{equation}
-P_i^- = -P_i^+  - \frac{\gamma}{R_i}
\label{YLeqn1}
\end{equation}
\begin{equation}
-P_o^+ = -P_o^- + \frac{\gamma}{R_o}
\label{YLeqn2}
\end{equation}
where the superscript plus and minus represent limits from the right and left, respectively. Since the cavity does not contain a significant concentration of molecules, the pressures inside of the cavity and at infinity are negligible, and Eqns.~(\ref{YLeqn1}) and~(\ref{YLeqn2}) can be combined into a single equation for the internal pressure difference at the interfaces,
\begin{equation}
P_o^- -P_i^+ = \gamma \left(\frac{1}{R_o} + \frac{1}{R_i}\right).
\label{YLeqn3}
\end{equation}
The kinematic boundary condition relates the change in radius with respect to time $t$ and the fluid velocity at the boundary:
\begin{equation}
\frac{\mathrm{d}R_i}{\mathrm{d}t} =U(R_i) = \frac{F}{R_i}.
\label{kbc}
\end{equation}
The problem is readily solved by converting the triple integral equations into a singular integral equation and numerically inverting to solve for the shear stress at each time step; for details the reader is referred to~\cite{Jia_etal2021}. However, in the limit of $R_o\to \infty$, the triple integral equations Eqns.~(\ref{tie1})-(\ref{tie3}) admit a simple analytical solution
\begin{equation}
b(k) = \mu F\frac{\sin k R_i}{k R_i}.
\label{bsoln}
\end{equation}
Employing the Hankel inversion theorem and substituting into the momentum equation yields  (cf. Formula~(6.693.1) of~\cite{GradshteynRyzhik2007}, differentiate with respect to $\alpha$, let $\nu \to 0$, and take a negative sign)
\begin{equation}
-\frac{\mathrm{d}P}{\mathrm{d}r} = \mu F\int_0^\infty \mathrm{d}k~ k \frac{\sin kR_i}{kR_i }J_1(kr) = \frac{\mu F}{r\sqrt{r^2-R_i^2}} \chi(r>R_i),
\end{equation}
where $\chi$ is a characteristic function. The monolayer pressure is then
\begin{equation}
P =- \mu F\frac{\cos^{-1} (R_i/r)}{R_i}
\label{Peqn}
\end{equation}
where the constant of integration has been taken to be zero. This gives
\begin{equation}
P_o^- - P_i^+ = -\frac{\pi \mu F}{2R_i},
\end{equation}
which, when combined with Eqn.~(\ref{YLeqn3}), produces the simple result
\begin{equation}
F =- \frac{2 \gamma}{\pi\mu}.
\label{Fresult}
\end{equation}
Since $dA/dt = 2\pi F$, the inviscid model predicts that the hole simply closes via ``flow by curvature'': the area of the cavity decreases linearly at a rate independent of  $R_i$ until it fully closes. As a consequence, the radial surface velocity at the interface $U(R_i) =F/R_i$ diverges as the hole radius goes to zero in this model.

For completeness, we remark that if $0<r<R_i$,
\begin{equation}
    U(r) = \frac{1}{\mu}\int_0^\infty \mathrm{d}k~b(k)J_1(kr) = \frac{F}{r}\left[1-\sqrt{1 - \left(\frac{r}{R_i}\right)^2}\right]
\end{equation}
gives the surface velocity inside of the cavity. As expected, the flow is not incompressible in this region.

\section{Adjusting the model}

The formulation as presented rests on the assumption that the film is surface inviscid
and therefore the surface shear stress is in  equilibrium with the surface pressure inside $\mathcal{D}$
for all times. We will amend the above treatment by allowing for the possibility of a monolayer viscosity. We now model the surface phase as governed by the incompressible two-dimensional Stokes equations, again forced by the surface shear stress of the bulk phase. In polar coordinates for an axisymmetric system these equations are:
\begin{equation}
\frac{1}{r} \frac{\mathrm{d}}{\mathrm{d}r}(rU) = 0
\label{newdivfree}
\end{equation}
\begin{equation}
\left. \mu \frac{\partial u}{\partial z}\right|_{z=0} = \chi(R_i<r<R_o) \left(-\frac{\mathrm{d}P}{\mathrm{d}r} + \eta \mathcal{L}[U]\right),
\label{momeqn}
\end{equation}
where $\eta$ is the monolayer viscosity and $\mathcal{L} = \partial_{rr} + (1/r)\partial_r -1/r^2$. As before, Eqn.~(\ref{newdivfree}) implies $U=F/r$ for some constant $F$. Amending Eqns.~(\ref{YLeqn1}) and (\ref{YLeqn2}), the stress balance at the interfaces becomes
\begin{equation}
-P_i^- = -P_i^+ -2\eta \frac{F}{R_i^2} - \frac{\gamma}{R_i}
\label{YLeqn1new}
\end{equation}
\begin{equation}
-P_o^+ = -P_o^- -2\eta \frac{F}{R_o^2} + \frac{\gamma}{R_o}.
\label{YLeqn2new}
\end{equation}
The form of the kinematic boundary condition Eqn.~(\ref{kbc}) is unchanged. In keeping with~\cite{Alexander_etal2006}, we will focus on the $R_o\to\infty$ limit with $P_i^-=P_o^+ = 0$.

It is instructive to consider the dimensionless version of the above equations. We choose $R_i$ to be the length scale, $V=\gamma/(\mu R_i)$ to be the velocity scale, and $\mu V$ to be the pressure scale. Identifying dimensionless quantities with their dimensional counterparts, the resulting momentum balance is
\begin{equation}
    \left. \frac{\partial u}{\partial z}\right|_{z=0} = \chi({r}>R_i)\left(-\frac{\mathrm{d}P}{\mathrm{d}r} + \frac{\eta/\mu}{R_i} \mathcal{L}[U]\right)
\end{equation}
which gives the dimensionless parameter $\beta = \ell_{\mathrm{SD}}/R_i$; here, $\ell_{\mathrm{SD}} = \eta/\mu$ is the Saffman-Delbr\"uck length for membranes. The corresponding dimensionless stress balance at the inner radius is
\begin{equation}
    -P_i^+ - 2 \beta F =1.

\end{equation}
We now discriminate between two subtle yet distinct cases. If $\beta = 0$, the monolayer viscosity drops out of the problem completely, and the solution follows the prescription of~\cite{Alexander_etal2006} outlined  above. The constant $F$ necessarily scales like $VR_i$, presaging the general form of Eqn.~(\ref{Fresult}).
On the other hand, when $\beta >0$, the monolayer viscosity continues to play no role in the bulk. This is because the radial annular flow $U=F/r$ is both incompressible and irrotational so that $\mathcal{L}[U]=0$.
Thus, regardless of $\beta$,  Eqns.~(\ref{momeqn1})-(\ref{momeqn3}) hold, so that Eqns.~(\ref{bsoln}) and (\ref{Peqn}) for $b(k)$ and $P$ are common to both scenarios. The effects of $\beta >0$ only materialize at the boundary, where an additional viscosity term emerges, and become non-negligible as $R_i$ goes to zero.

Taking the difference of Eqns.~(\ref{YLeqn1new}) and (\ref{YLeqn2new}), setting $P_i^- = P_o^+=0$ as before, and using Eqn.~(\ref{Peqn}) for $P$ gives the corrected
\begin{equation}
F = -\frac{\gamma}{ (2\eta/R_i )+ (\pi\mu/2)}.
\label{newFeqn}
\end{equation}
Note that $\eta>0$ regularizes $F$ so that $F\to 0$ as $R_i\to 0$, whereas $F$ is independent of $R_i$ in the $\beta=0$ surface inviscid case (Fig.~\ref{Fplots}a). The kinematic boundary condition can then be integrated to obtain an explicit relation for the cavity area $A$ as a function of time
\begin{equation}
A(t) = \frac{4}{\pi \mu^2} \left[2\eta - \sqrt{4\eta^2 + \pi \gamma \mu(t-t^*) }\right]^2,
\label{Avstnew}
\end{equation}
where $t^* = (2\eta R_{i,0} + \pi\mu R_{i,0}^2/4 )/\gamma$ is the closing time of the cavity written in terms of the initial radius $R_{i,0}$. If this result is substituted back into Eqn.~(\ref{newFeqn}), we find an explicit relation for $F$ as a function of time:
\begin{equation}
    F(t) = - \frac{2\gamma}{\pi \mu} \left(1 - \frac{1}{\sqrt{1 + \pi \mu \gamma (t^*-t)/(4\eta^2)}}\right)
\end{equation}
If $\eta \to 0$ in this expression, we recover Eqn.~(\ref{Fresult}). On the other hand, fixing $\eta$ and expanding in small $t^*-t$ gives the result
\begin{equation}
    F(t) = -\frac{2\gamma}{\pi \mu}\left[ \frac{\pi \mu \gamma}{8\eta^2} (t^*-t) + \hdots\right] = -\frac{\gamma^2}{4\eta^2} (t^*-t) + \hdots
\end{equation}
which demonstrates the rapid variation of $F$ to zero as the cavity closes in the  case of a viscous monolayer.

\begin{figure}
\centering
\includegraphics[scale=0.165]{lf_plot_F.png}
\includegraphics[scale=0.165]{lf_comparison_vary_eta_v2.png}
\caption
 (a) The constant $F$ from Eqn.~(\ref{newFeqn}), which determines the rate of decrease of the cavity area, as a function of time for different values of the parameter $\beta=\eta/(\mu R_{i,0})$, with $R_{i,0}$ the initial cavity radius. Parameters: $\gamma = 0.01$, $\mu = 10$. Note that $F(t^*)$ is not zero when $\eta=0$, while $F$ increases to zero linearly with a slope proportional to $\eta^{-2}$ when $\eta>0$ and the hole radius is small compared to the Saffman-Delbr\"uck length $\ell_{\mathrm{SD}}=\eta/\mu$. (b) Increasing monolayer viscosity slows down the closing of the cavity. Same parameters. The cavity area exhibits an initial linear small $\beta$ regime followed by a quadratic large $\beta$ regime as the cavity radius becomes comparable to $\ell_{\mathrm{SD}}$.}
\label{Fplots}
\end{figure}

The surface inviscid result of linearly decreasing area found by~\cite{Alexander_etal2006} is a valid approximation for early times if monolayer viscosity is indeed small, as Fig.~\ref{Fplots}a illustrates. However, the predicted slope of $-4\gamma/\mu$ does not hold as well for intermediate times in the presence of nonzero viscosity.
The $O(\beta)$ perturbation to the slope at early times can be found by calculating
\begin{equation}
    \frac{\mathrm{d}A}{\mathrm{d}t}|_{t=0} = 2\pi F|_{t=0} = -\frac{4\gamma}{\mu} \left(1 - \frac{2\eta}{\sqrt{\pi \mu \gamma t^*}} + \hdots\right)
\end{equation}
where we have taken $\eta$ sufficiently smaller than $\mu R_i$. Thus, the line tension value obtained from fitting data to the inviscid model is likely an underestimate.

In the opposite regime where the hole becomes sufficiently small, the viscous stress dominates, and $F \sim -\gamma R_i/(2\eta) $. That is, the cavity area changes  quadratically with time in this regime, and the inviscid monolayer model consequently underestimates the closure time.
The experimental data in Figure 6 of~\cite{Alexander_etal2006}
demonstrate a prominent quadratic-like slowing when the hole is small that may be representative of a monolayer viscosity. Figure~\ref{newfitplot}a compares the authors' original linear fit to the result of fitting to the modified area vs. time relation Eqn.~(\ref{Avstnew}); the modification allows for a more accurate description of a broader range of data. The fit parameters were found to be a line tension of $\gamma = 5.54\times 10^{-12}$ N and monolayer viscosity of $\eta = 6.80\times 10^{-7}$ kg/s, for the value of $\mu = 1.063\times 10^{-3}$ kg/m$\text{ s}$ used in~\cite{Alexander_etal2006}. The corresponding Saffman-Delbr\"uck length is $\ell_{\mathrm{SD}} = 0.64$ mm, which gives a $\beta$ that is $O(1)$ at the initial time and confirms that the layer should not be treated as inviscid.

Figure~\ref{newfitplot}b compares the same fit with the more recent experimental data from~\cite{Zou_etal2010} with a horizontal shift selected so that there is maximum overlap (the data in the original image were also shifted in this manner); again, we see a strong agreement between the modified theory and the experiment.

\begin{figure}
    \centering

    \includegraphics[scale=0.179]{lf_newfit_v2.png}
    \includegraphics[scale=0.204]{Langmuir film/zou_data_fit_edit.png}
    \caption{(a) A reproduction of Figure 6 of~\cite{Alexander_etal2006} showing five different runs of experimental hole sizes as a function of time. As in the original paper, each run has been shifted horizontally to maximize overlap. The data are nonlinear when the hole becomes small, which could possibly be an effect of monolayer viscosity. The blue line is the linear fit that appeared in the paper originally; the red line is the fit of Eqn.~(23) which uses monolayer viscosity as an additional fit parameter and more accurately describes a broader range of data. The line tension and monolayer viscosity obtained from fitting are $\gamma = 5.54\times 10^{-12}$ N and $\eta = 6.80\times 10^{-7}$ kg/s.  {(b) A reproduction of Figure 4 from~\cite{Zou_etal2010}, plotting the fit with the same parameters with a time shift on top of the experimental data. The vertical axis is on a base 10 log scale.}}
    \label{newfitplot}
\end{figure}

\section{Conclusion}

Effectively, two regimes comprise the closing of a (sufficiently large) cavity in a Langmuir film. The first is a tension-dominated regime where the area decreases linearly. This is followed by a viscosity-dominated regime where the area decreases quadratically just as the hole is about to close, effectively regularizing the singularity. The two regimes can be delineated by the dimensionless parameter $\beta$, which is a ratio of the Saffman-Delbr\"uck length to the cavity radius.

We applied our theory to the experiments of~\cite{Alexander_etal2006}. By allowing for a monolayer viscosity in the model they proposed for the closing of a Langmuir film, the improved theory matches the original experiment more closely over a broader range of data. From fitting, we find a line tension of approximately 5.5 pN, which is the same order of magnitude as the previously reported values of $0.69\pm 0.02$ pN from~\cite{Zou_etal2010} and $1.1\pm 0.3$ pN from~\cite{Mann_etal1992}, but is different enough to see that the effects of monolayer viscosity are perhaps not as negligible for this system as the authors believed.

As mentioned above, the vanishing of $\eta$ from the bulk equations is a consequence of the symmetries of this particular problem. The effects of monolayer viscosity in a nonannular domain should be investigated as well. The flow field of a disk-shaped monolayer of actively rotating colloidal magnets has already produced one example of an axisymmetric system where monolayer viscosity plays a nontrivial role in the bulk~(\cite{Jia_etal2021}); presumably there are many others. It would be interesting to study the effects of a surface viscosity on domain relaxation in nonaxisymmetric Langmuir films, akin to the work done by~\cite{Alexander_etal2007}.

{\bf Acknowledgements:}
MJS acknowledges support by the National Science Foundation under awards DMR-1420073 (NYU MRSEC) and DMR-2004469.

\bibliographystyle{jfm}

\section{Introduction}
An understanding of the hydrodynamics of a quasi-2D fluid interface coupled to a bulk 3D subphase is crucial to modeling the dynamics of a wide variety of biological systems such as lipid membranes~(\cite{StoneMcConnell1995}), bacterial biofilms~(\cite{Petroff_etal2005}), and algae colonies~(\cite{Drescher_etal2009}). One notable theoretical and experimental study of such a system was conducted by~\cite{Alexander_etal2006}, who examined the tension-driven closing of a cavity punctured in a PDMS monolayer situated on a flat water-air interface.
The authors derived an analytical solution for the axisymmetric fluid motion, predicting that the area of the cavity closes at a fixed rate that depends only on the ratio of monolayer line tension to bulk viscosity; by fitting experimental data in a linear regime of the area vs. time plot, they obtained an estimate for the line tension. The same authors later reapplied this model along with improved experimental methods to obtain a more accurate value for the monolayer line tension, which they reported to be $0.69\pm 0.02$ pN in~\cite{Zou_etal2010}.

The reduction of this problem to the fitting of a single parameter hinges on a crucial assumption: the monolayer viscosity is vanishingly small. While there is experimental evidence supporting the claim that the film dynamics is dominated by subphase viscosity rather than monolayer viscosity~(\cite{Mann_etal1995}), and while there are strongly linear regimes in the experimental area vs. time data in both~\cite{Alexander_etal2006} and~\cite{Zou_etal2010}, the data as a whole is visibly nonlinear, especially at later times when the hole size is small. This indicates that the inviscid assumption may not hold as well as previously thought and that viscous effects of the monolayer may be playing a role in the closure process.

Here we revisit the theoretical model proposed by~\cite{Alexander_etal2006} and amend it by considering the effects of a regularizing monolayer viscosity. This simple change preserves much of the structure of the problem but introduces some notable differences. We find that while the bulk equations are unchanged in the axisymmetric case, the boundary conditions can depend strongly on this monolayer viscosity, especially in regimes where the cavity radius is small relative to the Saffman-Delbr\"uck length--that is, the ratio of the 2D monolayer and 3D bulk viscosities.
In this regime, the predicted dependence of cavity area on time becomes noticeably nonlinear,
which impacts the fitting of experimental data and consequently suggests that these previous studies have underestimated the edge tension by roughly one order of magnitude.

\section{Summary of the original model}

We begin by reviewing the system description given in~\cite{Alexander_etal2006}. Consider a molecularly thin (so essentially two-dimensional) fluid monolayer situated on a three-dimensional half-space of Stokes fluid with flow field $\boldsymbol{u}$ and viscosity $\mu$.  The domain of the monolayer is taken to be the annulus centered at the origin in the $z=0$ plane, $\mathcal{D} = \{(r,0): 0< R_i< r < R_o\}$, where $R_o$ can be infinite. The interface is assumed to be planar for all times, and the flow field of the interface, $\boldsymbol{U} = \boldsymbol{u}(z=0)$, is assumed to have no $z$-component. If the monolayer is 2D incompressible, then the radial component of $\boldsymbol{U}$, which we denote by  $U(r)$, satisfies
\begin{equation}
    \frac{1}{r}\frac{\mathrm{d}}{\mathrm{d}r} (rU)= 0
    \label{divUeqn}
\end{equation}
so that it necessarily has the form
\begin{equation}
U(r) = \frac{F}{r}
\label{Ueqn}
\end{equation}
for some constant $F$ when $R_i <r <R_o$. In the absence of tangential stresses, the tangential component of $\boldsymbol{U}$ vanishes.

In deriving the momentum equation,~\cite{Alexander_etal2006} employ the so-called ``hydrostatic approximation'': the monolayer viscosity is so small that the film may be treated as inviscid. Hence, it is simply the pressure gradient that balances the shear forces from the fluid subphase where it is in contact with the monolayer. Elsewhere, a stress-free interface is assumed:
\begin{equation}
\left.\mu \frac{\partial u}{\partial z}\right|_{z=0} = 0\text{ , } 0<r<R_i
\label{momeqn1}
\end{equation}
\begin{equation}
\left.\mu \frac{\partial u}{\partial z}\right|_{z=0} = -\frac{\mathrm{d}P}{\mathrm{d}r}\text{ , } R_i<r<R_o
\label{momeqn2}
\end{equation}
\begin{equation}
\left.\mu \frac{\partial u}{\partial z}\right|_{z=0} = 0\text{ , } r>R_o
\label{momeqn3}
\end{equation}
where $u$ is the radial component of $\boldsymbol{u}$ and $P$ is the 2D pressure inside of the monolayer. Using standard Hankel transform methods, an equivalent set of triple integral equations can be derived:
\begin{equation}
\int_0^\infty \mathrm{d}k~ k b(k) J_1(kr) = 0\text{ , } 0<r<R_i
\label{tie1}
\end{equation}
\begin{equation}
\int_0^\infty \mathrm{d}k~ b(k) J_1(kr) =  \frac{\mu F}{r} \text{, }R_i<r<R_o
\label{tie2}
\end{equation}
\begin{equation}
\int_0^\infty \mathrm{d}k~ k b(k) J_1(kr) = 0\text{ , } r>R_o
\label{tie3}
\end{equation}
where we have defined $k$ to be the wavenumber and
\begin{equation}
b(k) = \int_0^\infty \mathrm{d}r~ r  \mu \frac{\partial u}{\partial z}(r,z=0) J_1(kr).
\label{bdef}
\end{equation}

The problem is then closed by enforcing the boundary conditions of normal stress balance. In this case, these are simply  the Young-Laplace relations
\begin{equation}
-P_i^- = -P_i^+  - \frac{\gamma}{R_i}
\label{YLeqn1}
\end{equation}
\begin{equation}
-P_o^+ = -P_o^- + \frac{\gamma}{R_o}
\label{YLeqn2}
\end{equation}
where the superscript plus and minus represent limits from the right and left, respectively. Since the cavity does not contain a significant concentration of molecules, the pressures inside of the cavity and at infinity are negligible, and Eqns.~(\ref{YLeqn1}) and~(\ref{YLeqn2}) can be combined into a single equation for the internal pressure difference at the interfaces,
\begin{equation}
P_o^- -P_i^+ = \gamma \left(\frac{1}{R_o} + \frac{1}{R_i}\right).
\label{YLeqn3}
\end{equation}
The kinematic boundary condition relates the change in radius with respect to time $t$ and the fluid velocity at the boundary:
\begin{equation}
\frac{\mathrm{d}R_i}{\mathrm{d}t} =U(R_i) = \frac{F}{R_i}.
\label{kbc}
\end{equation}
The problem is readily solved by converting the triple integral equations into a singular integral equation and numerically inverting to solve for the shear stress at each time step; for details the reader is referred to~\cite{Jia_etal2021}. However, in the limit of $R_o\to \infty$, the triple integral equations Eqns.~(\ref{tie1})-(\ref{tie3}) admit a simple analytical solution
\begin{equation}
b(k) = \mu F\frac{\sin k R_i}{k R_i}.
\label{bsoln}
\end{equation}
Employing the Hankel inversion theorem and substituting into the momentum equation yields  (cf. Formula~(6.693.1) of~\cite{GradshteynRyzhik2007}, differentiate with respect to $\alpha$, let $\nu \to 0$, and take a negative sign)
\begin{equation}
-\frac{\mathrm{d}P}{\mathrm{d}r} = \mu F\int_0^\infty \mathrm{d}k~ k \frac{\sin kR_i}{kR_i }J_1(kr) = \frac{\mu F}{r\sqrt{r^2-R_i^2}} \chi(r>R_i),
\end{equation}
where $\chi$ is a characteristic function. The monolayer pressure is then
\begin{equation}
P =- \mu F\frac{\cos^{-1} (R_i/r)}{R_i}
\label{Peqn}
\end{equation}
where the constant of integration has been taken to be zero. This gives
\begin{equation}
P_o^- - P_i^+ = -\frac{\pi \mu F}{2R_i},
\end{equation}
which, when combined with Eqn.~(\ref{YLeqn3}), produces the simple result
\begin{equation}
F =- \frac{2 \gamma}{\pi\mu}.
\label{Fresult}
\end{equation}
Since $dA/dt = 2\pi F$, the inviscid model predicts that the hole simply closes via ``flow by curvature'': the area of the cavity decreases linearly at a rate independent of  $R_i$ until it fully closes. As a consequence, the radial surface velocity at the interface $U(R_i) =F/R_i$ diverges as the hole radius goes to zero in this model.

For completeness, we remark that if $0<r<R_i$,
\begin{equation}
    U(r) = \frac{1}{\mu}\int_0^\infty \mathrm{d}k~b(k)J_1(kr) = \frac{F}{r}\left[1-\sqrt{1 - \left(\frac{r}{R_i}\right)^2}\right]
\end{equation}
gives the surface velocity inside of the cavity. As expected, the flow is not incompressible in this region.

\section{Adjusting the model}

The formulation as presented rests on the assumption that the film is surface inviscid
and therefore the surface shear stress is in  equilibrium with the surface pressure inside $\mathcal{D}$
for all times. We will amend the above treatment by allowing for the possibility of a monolayer viscosity. We now model the surface phase as governed by the incompressible two-dimensional Stokes equations, again forced by the surface shear stress of the bulk phase. In polar coordinates for an axisymmetric system these equations are:
\begin{equation}
\frac{1}{r} \frac{\mathrm{d}}{\mathrm{d}r}(rU) = 0
\label{newdivfree}
\end{equation}
\begin{equation}
\left. \mu \frac{\partial u}{\partial z}\right|_{z=0} = \chi(R_i<r<R_o) \left(-\frac{\mathrm{d}P}{\mathrm{d}r} + \eta \mathcal{L}[U]\right),
\label{momeqn}
\end{equation}
where $\eta$ is the monolayer viscosity and $\mathcal{L} = \partial_{rr} + (1/r)\partial_r -1/r^2$. As before, Eqn.~(\ref{newdivfree}) implies $U=F/r$ for some constant $F$. Amending Eqns.~(\ref{YLeqn1}) and (\ref{YLeqn2}), the stress balance at the interfaces becomes
\begin{equation}
-P_i^- = -P_i^+ -2\eta \frac{F}{R_i^2} - \frac{\gamma}{R_i}
\label{YLeqn1new}
\end{equation}
\begin{equation}
-P_o^+ = -P_o^- -2\eta \frac{F}{R_o^2} + \frac{\gamma}{R_o}.
\label{YLeqn2new}
\end{equation}
The form of the kinematic boundary condition Eqn.~(\ref{kbc}) is unchanged. In keeping with~\cite{Alexander_etal2006}, we will focus on the $R_o\to\infty$ limit with $P_i^-=P_o^+ = 0$.

It is instructive to consider the dimensionless version of the above equations. We choose $R_i$ to be the length scale, $V=\gamma/(\mu R_i)$ to be the velocity scale, and $\mu V$ to be the pressure scale. Identifying dimensionless quantities with their dimensional counterparts, the resulting momentum balance is
\begin{equation}
    \left. \frac{\partial u}{\partial z}\right|_{z=0} = \chi({r}>R_i)\left(-\frac{\mathrm{d}P}{\mathrm{d}r} + \frac{\eta/\mu}{R_i} \mathcal{L}[U]\right)
\end{equation}
which gives the dimensionless parameter $\beta = \ell_{\mathrm{SD}}/R_i$; here, $\ell_{\mathrm{SD}} = \eta/\mu$ is the Saffman-Delbr\"uck length for membranes. The corresponding dimensionless stress balance at the inner radius is
\begin{equation}
    -P_i^+ - 2 \beta F =1.

\end{equation}
We now discriminate between two subtle yet distinct cases. If $\beta = 0$, the monolayer viscosity drops out of the problem completely, and the solution follows the prescription of~\cite{Alexander_etal2006} outlined  above. The constant $F$ necessarily scales like $VR_i$, presaging the general form of Eqn.~(\ref{Fresult}).
On the other hand, when $\beta >0$, the monolayer viscosity continues to play no role in the bulk. This is because the radial annular flow $U=F/r$ is both incompressible and irrotational so that $\mathcal{L}[U]=0$.
Thus, regardless of $\beta$,  Eqns.~(\ref{momeqn1})-(\ref{momeqn3}) hold, so that Eqns.~(\ref{bsoln}) and (\ref{Peqn}) for $b(k)$ and $P$ are common to both scenarios. The effects of $\beta >0$ only materialize at the boundary, where an additional viscosity term emerges, and become non-negligible as $R_i$ goes to zero.

Taking the difference of Eqns.~(\ref{YLeqn1new}) and (\ref{YLeqn2new}), setting $P_i^- = P_o^+=0$ as before, and using Eqn.~(\ref{Peqn}) for $P$ gives the corrected
\begin{equation}
F = -\frac{\gamma}{ (2\eta/R_i )+ (\pi\mu/2)}.
\label{newFeqn}
\end{equation}
Note that $\eta>0$ regularizes $F$ so that $F\to 0$ as $R_i\to 0$, whereas $F$ is independent of $R_i$ in the $\beta=0$ surface inviscid case (Fig.~\ref{Fplots}a). The kinematic boundary condition can then be integrated to obtain an explicit relation for the cavity area $A$ as a function of time
\begin{equation}
A(t) = \frac{4}{\pi \mu^2} \left[2\eta - \sqrt{4\eta^2 + \pi \gamma \mu(t-t^*) }\right]^2,
\label{Avstnew}
\end{equation}
where $t^* = (2\eta R_{i,0} + \pi\mu R_{i,0}^2/4 )/\gamma$ is the closing time of the cavity written in terms of the initial radius $R_{i,0}$. If this result is substituted back into Eqn.~(\ref{newFeqn}), we find an explicit relation for $F$ as a function of time:
\begin{equation}
    F(t) = - \frac{2\gamma}{\pi \mu} \left(1 - \frac{1}{\sqrt{1 + \pi \mu \gamma (t^*-t)/(4\eta^2)}}\right)
\end{equation}
If $\eta \to 0$ in this expression, we recover Eqn.~(\ref{Fresult}). On the other hand, fixing $\eta$ and expanding in small $t^*-t$ gives the result
\begin{equation}
    F(t) = -\frac{2\gamma}{\pi \mu}\left[ \frac{\pi \mu \gamma}{8\eta^2} (t^*-t) + \hdots\right] = -\frac{\gamma^2}{4\eta^2} (t^*-t) + \hdots
\end{equation}
which demonstrates the rapid variation of $F$ to zero as the cavity closes in the  case of a viscous monolayer.

\begin{figure}
\centering
\includegraphics[scale=0.165]{lf_plot_F.png}
\includegraphics[scale=0.165]{lf_comparison_vary_eta_v2.png}
\caption
 (a) The constant $F$ from Eqn.~(\ref{newFeqn}), which determines the rate of decrease of the cavity area, as a function of time for different values of the parameter $\beta=\eta/(\mu R_{i,0})$, with $R_{i,0}$ the initial cavity radius. Parameters: $\gamma = 0.01$, $\mu = 10$. Note that $F(t^*)$ is not zero when $\eta=0$, while $F$ increases to zero linearly with a slope proportional to $\eta^{-2}$ when $\eta>0$ and the hole radius is small compared to the Saffman-Delbr\"uck length $\ell_{\mathrm{SD}}=\eta/\mu$. (b) Increasing monolayer viscosity slows down the closing of the cavity. Same parameters. The cavity area exhibits an initial linear small $\beta$ regime followed by a quadratic large $\beta$ regime as the cavity radius becomes comparable to $\ell_{\mathrm{SD}}$.}
\label{Fplots}
\end{figure}

The surface inviscid result of linearly decreasing area found by~\cite{Alexander_etal2006} is a valid approximation for early times if monolayer viscosity is indeed small, as Fig.~\ref{Fplots}a illustrates. However, the predicted slope of $-4\gamma/\mu$ does not hold as well for intermediate times in the presence of nonzero viscosity.
The $O(\beta)$ perturbation to the slope at early times can be found by calculating
\begin{equation}
    \frac{\mathrm{d}A}{\mathrm{d}t}|_{t=0} = 2\pi F|_{t=0} = -\frac{4\gamma}{\mu} \left(1 - \frac{2\eta}{\sqrt{\pi \mu \gamma t^*}} + \hdots\right)
\end{equation}
where we have taken $\eta$ sufficiently smaller than $\mu R_i$. Thus, the line tension value obtained from fitting data to the inviscid model is likely an underestimate.

In the opposite regime where the hole becomes sufficiently small, the viscous stress dominates, and $F \sim -\gamma R_i/(2\eta) $. That is, the cavity area changes  quadratically with time in this regime, and the inviscid monolayer model consequently underestimates the closure time.
The experimental data in Figure 6 of~\cite{Alexander_etal2006}
demonstrate a prominent quadratic-like slowing when the hole is small that may be representative of a monolayer viscosity. Figure~\ref{newfitplot}a compares the authors' original linear fit to the result of fitting to the modified area vs. time relation Eqn.~(\ref{Avstnew}); the modification allows for a more accurate description of a broader range of data. The fit parameters were found to be a line tension of $\gamma = 5.54\times 10^{-12}$ N and monolayer viscosity of $\eta = 6.80\times 10^{-7}$ kg/s, for the value of $\mu = 1.063\times 10^{-3}$ kg/m$\text{ s}$ used in~\cite{Alexander_etal2006}. The corresponding Saffman-Delbr\"uck length is $\ell_{\mathrm{SD}} = 0.64$ mm, which gives a $\beta$ that is $O(1)$ at the initial time and confirms that the layer should not be treated as inviscid.

Figure~\ref{newfitplot}b compares the same fit with the more recent experimental data from~\cite{Zou_etal2010} with a horizontal shift selected so that there is maximum overlap (the data in the original image were also shifted in this manner); again, we see a strong agreement between the modified theory and the experiment.

\begin{figure}
    \centering

    \includegraphics[scale=0.179]{lf_newfit_v2.png}
    \includegraphics[scale=0.204]{Langmuir film/zou_data_fit_edit.png}
    \caption{(a) A reproduction of Figure 6 of~\cite{Alexander_etal2006} showing five different runs of experimental hole sizes as a function of time. As in the original paper, each run has been shifted horizontally to maximize overlap. The data are nonlinear when the hole becomes small, which could possibly be an effect of monolayer viscosity. The blue line is the linear fit that appeared in the paper originally; the red line is the fit of Eqn.~(23) which uses monolayer viscosity as an additional fit parameter and more accurately describes a broader range of data. The line tension and monolayer viscosity obtained from fitting are $\gamma = 5.54\times 10^{-12}$ N and $\eta = 6.80\times 10^{-7}$ kg/s.  {(b) A reproduction of Figure 4 from~\cite{Zou_etal2010}, plotting the fit with the same parameters with a time shift on top of the experimental data. The vertical axis is on a base 10 log scale.}}
    \label{newfitplot}
\end{figure}

\section{Conclusion}

Effectively, two regimes comprise the closing of a (sufficiently large) cavity in a Langmuir film. The first is a tension-dominated regime where the area decreases linearly. This is followed by a viscosity-dominated regime where the area decreases quadratically just as the hole is about to close, effectively regularizing the singularity. The two regimes can be delineated by the dimensionless parameter $\beta$, which is a ratio of the Saffman-Delbr\"uck length to the cavity radius.

We applied our theory to the experiments of~\cite{Alexander_etal2006}. By allowing for a monolayer viscosity in the model they proposed for the closing of a Langmuir film, the improved theory matches the original experiment more closely over a broader range of data. From fitting, we find a line tension of approximately 5.5 pN, which is the same order of magnitude as the previously reported values of $0.69\pm 0.02$ pN from~\cite{Zou_etal2010} and $1.1\pm 0.3$ pN from~\cite{Mann_etal1992}, but is different enough to see that the effects of monolayer viscosity are perhaps not as negligible for this system as the authors believed.

As mentioned above, the vanishing of $\eta$ from the bulk equations is a consequence of the symmetries of this particular problem. The effects of monolayer viscosity in a nonannular domain should be investigated as well. The flow field of a disk-shaped monolayer of actively rotating colloidal magnets has already produced one example of an axisymmetric system where monolayer viscosity plays a nontrivial role in the bulk~(\cite{Jia_etal2021}); presumably there are many others. It would be interesting to study the effects of a surface viscosity on domain relaxation in nonaxisymmetric Langmuir films, akin to the work done by~\cite{Alexander_etal2007}.

{\bf Acknowledgements:}
MJS acknowledges support by the National Science Foundation under awards DMR-1420073 (NYU MRSEC) and DMR-2004469.

\bibliographystyle{jfm}

redpajama_set_name: RedPajamaArXiv


text:
Home Animation PalmCon is this Saturday September 21st!
PalmCon is this Saturday September 21st!
Joe Fauvel
PalmCon: The Palm Beach County Comic Book and Collectibles Show
When: September 21st 2013 from 10:00 AM to 6:00 PM
Where: The Palm Beach County Convention Center – 650 Okeechobee Boulevard West Palm Beach, FL 33401
Admission: $9.00 for Adults at the door – $7.00 in advance (on-line), $5.00 for kids 4-13 at the door – $4.00 in advance (on-line), FREE for children 3 and under.
PalmCon: The Palm Beach Comic Book and Collectibles Show is Palm Beach County's only comic convention of its kind. This is the third year for PalmCon and for the first year we are moving to the Palm Beach County Convention Center occupying over 50,000 square feet of convention space. As with years past, we strive to bring Palm Beach County the best in comics, animation, and pop-culture while providing a fun and safe family friendly atmosphere.
We are pleased to have film and television actor Deep Roy as one of our guests. Most know him for his role as all of the Oompa Loompas in Tim Burton's Charlie and the Chocolate Factory. Deep Roy also holds the honor of being the only actor to appear on screen in all three major science-fiction franchises – Doctor Who, Star Trek and Star Wars. He has also appeared in Transformers, The NeverEnding Story, Flash Gordon, Return to Oz, and he had a recurring role in the HBO series Eastbound and Down. Other media guests include Jim Decker and Robert Z'Dar who is known for his B-movie roles but has also appeared in mainstream films such as Tango and Cash.
PalmCon will also play host to some top names in comics including Ethan Van Sciver who is know for his work at DC Comics on Green Lantern, the Flash and most recently Batman. Returning this year will be comic book legend Jose Delbo who has been in the industry for years working on such titles as Wonder Woman, The Transformers, The Twilight Zone and The ThunderCats. Joining us for the first time will be Allen Bellman who is best known for his work on Captain America back in the 1940s at the start of the "golden age of comic books". Also making a rare convention appearance will be Carlos Castellanos the cocreator of the wildly popular nationally syndicated comic strip Baldo.
Other attractions at PalmCon will include an appearance by the 501st Legion and the Mandalorian Mercs known for their movie accurate Star Wars costumes and community involvement. Also arriving in time for the show will be a replica of the Ghostbusters's car Ecto-1 along with the Carolina and Miami Ghostbusters fan groups. As an added bonus to PalmCon this year we are bringing in the Art of Akira Exhibit that features original hand panted cells and production art from Japan's most famous animated film – Akira. PalmCon continues to receive an amazing amount of support from the local comic scene. Most of the major comic shops in South Florida will be represented at PalmCon along with over 100 vendors, artists, publishers and filmmakers. There will be a raffle, a costume contest, and the Indie-Film Screening Room showing short films created by local filmmakers.
This event grew out of Martin T. Pierro's love for the small hotel and mall comic shows that were a staple of his childhood days in West Palm Beach. In recent years there has been a resurgence of interest in comic book characters (as evident by the recent blockbuster films The Avengers, Iron Man 3 and The Dark Knight Rises), so it seemed a perfect time to bring these types of shows back to Palm Beach County.
More information and a complete guest/vendor list can be found here:
www.cosmictimes.net/palmcon
Feel free to contact Martin with any questions or comments here:
561.601.4137 – PalmCon@CosmicTimes.net
Cosmic Times
PalmCon
Previous articleWizard World Plans Massive Expansion for 2014; Adds Seven Cities to Their Comic Con Tour
Next articleLas Vegas Comic Expo 2013 to Show It's Chic to be Geek in Vegas
http://www.crycomic.com/
Artist of CRY and a Jedi Master.
PalmCon wants YOUR input!
Melbourne Toy and Comic Con is March 19th!
Baltimore Comic-Con 2017 Tickets Now On-Sale

redpajama_set_name: RedPajamaCommonCrawl


text:
El nombre de Basílica de Santo Domingo es el nombre de varios edificios religiosos, catalogados como basílicas en honor a algún santo llamado ''Domingo'.

Basílicas

Argentina
 Basílica de Santo Domingo, en la ciudad de Córdoba.

Italia
Basílica di San Domenico
 Basílica de Santo Domingo, en la localidad de Barletta, Apulia.
 Basílica de Santo Domingo, en la localidad de Bolonia, Emilia-Romagna.
 Basílica de Santo Domingo, en la localidad de Cremona, Lombardía.
 Basílica de Santo Domingo, en la localidad de Lecce, Apulia.
 Basílica de Santo Domingo, en la localidad de Nápoles, Campania.
 Basílica de Santo Domingo, en la localidad de Perugia, Umbría.
 Basílica de Santo Domingo, en la localidad de Siena, Toscana.

Perú
 Basílica de Santo Domingo, en la ciudad de Lima.


Winter is almost done and was not only late, but a rather ill-mannered no-show in my garden this year. Here in Central Texas, the trees are flowering and leafing out with abandon, seemingly racing one another to full-fledged foliage. Even so, the only plants that are weirdly early in my gardens are the Shumard Oaks–they don't normally flush new growth until the very end of February or beginning of March.
But like an excellent and welcomed dinner guest, the Golden Groundsel, Packera obovata, is right on time in preparation for its flower show. One of our earliest bloomers, the bloom stalks have arisen and will brighten this shady area in the next few weeks.
…the foliage of this tidy, woodland wildflower is what I find most appealing about this North American beauty. Evergreen and ever-lush, the plant forms a colony of finely serrated, ovate leaves and those make up the "staple" foliage of the plant, year round.
A sprinkling of rain in the last 24 hours is the only rain for the past month.
As the plant prepares for flowering, the foliage connected to the bloom pedicels develops a more fern-like, deeply serrated character.
The two-fer foliage quality of this wildflower is captivating.
…and a handsome ground-cover throughout the year.
Perhaps the blooms will be up and running in time for Garden Bloggers' Bloom Day in March!
In celebration of February foliage, thanks to Christina's lovely Creating my own garden of the Hesperides. Check out her Garden Bloggers' Foliage Day meme for a look at foliage from many gardens.
This entry was posted in Golden Groundsel, Packera obovata, Uncategorized and tagged Garden Bloggers' Foliage Day, GBFD by Tina. Bookmark the permalink.
Packera obovata, is a real beauty, maybe it is something I could grow here. Does it tolerate cold, if the soil is free draining? Thanks for joining GBFD this month Tina.
Yes to both of your questions! My soil is rather clayey and the Golden Groundsel has grown just fine, spreading slowly over the years. My climate is probably similar to yours–hot-n-dry for the summers, wetter in winter, though I'll bet we're not quite as cold as you are. This is a native to a large area of North America, so I don't know whether it would be invasive where you are–probably not–but let me know if you grow it and how it does for you.
Thanks for that. Clay would make your soil moister than mine.
Also, this plant has a wide range in North America and lives in much colder climates than mine, so I imagine it would do well for you. Let me know!
It's so pretty and such a nice addition to the early spring garden. I've had Golden Groundsel on my list for a while and hope to add it one day. I think I need to find it at a plant sale that specializes in native plants.
Shirley, I think I bought mine at BSN, but the WC has it on their spring plant sale list most years–if you're in Austin for that. Good luck with your search.
Your golden groundsel is a really lovely plant Tina, I like the expression two-fer, the double whammy of foliage is a winner and the flowers lovely too.
Thanks, Julie–I really like it quite a bit. Ha–I don't know where that expression comes from (two-fer); I guess I should look it up. 🙂 It's a lovely plant, all around–"double whammy" is a good description, too!
Oh, yes, it does appear it will be blooming nicely for the next GBBD! It looks so fresh and optimistic. The blooms and the foliage are wonderful!
That's a great description, Beth: fresh and optimistic. It's a very spring-y plant, I would agree with that.
I find the two different leaf shapes fascinating and the tiny flowers so cheerful. I imagine I would smile each time I looked at this plant in bloom. This is one I'll keep in mind for the shady spots.
It's definitely a plant that brings on a smile, Tracy. Golden Groundsel is a terrific, shade-tolerant perennial.
I'd been excited, thinking I had some Golden Groundsel appearing in an unmulched bed, but it turns out it was yellow blooming dandelion variants, a weed by most standards, and not the two-staged native I'd hoped for. The leaves are roughly similar, but the flowers not nearly so prominent. Close….but no cigar!
Now that I have this post for reference, I doubt I'll be tricked so easily again, but I'm such a sucker for yellow flowers appearing on almost any sort of rosette. So cheery and bright in those shady corners. I'm keeping an eye out for it now at my favorite nursery. I'm not putting in m/any new plants due to the rough weather we're having, but tried and true natives are always welcome here!
Let's see: yellow blooms and puffy, wind-borne seeds–might be Golden Groundsel or dandies! 🙂 I've never had my GGs seed out successfully, despite allowing them to go to seed each year. I don't know if it's the mulch in my gardens or if maybe the wind really does carry the seeds elsewhere, though in my 'hood that would mean their getting mowed as soon as they're established. If you can find a four inch or larger pot, you'll be in GG business, though–I hope that happens, because these are something to really look forward to.


The Voice coach Alicia Keys took center stage at the Staples Center as the host of the 61st annual show. Some big names who performed tonight included Miley Cyrus, Shawn Mendes, Camila Cabello Red Hot Chili Peppers, Post Malone and more. On Feb. 4, E! News confirmed that the ultra popular K-pop band BTSwill be among the presenters at the Grammys, which caused much fanfare among their massive fan base. They made their red carpet debut and gushed about their wonderful fan base.
The Grammy Awards honor music that was released between Oct. 1, 2017 and Sept. 30, 2018 so, just like every year, the nomination categories are stacked with talent.Cardi B, Bad Bunny and J Balvin's hit song "I Like It" goes against the likes of Drake's "God's Plan," Childish Gambino's "This Is America," Bradley Cooper and Lady Gagas "Shallow" and more for Record of the Year. We can expect to see the A Star Is Born co-stars performing the nominated song, which they practiced live a few weeks ago during a surprise duet in Las Vegas at one of Gaga's Enigma shows.
While there's always something to talk about inside the show (helloBlue Ivy Carter urging her parents Beyonce and Jay-Z to chill), there's a ton to discuss in terms of red carpet moments, too. For starters, let's talk about Cardi B's absolutely iconic outfit and her PDA-filled moment with her husband, Offset.
The 2019 Grammys are sure to be filled with a ton of noteworthy moments, so E! News has got you covered with everything you didn't see on TV.
CeeLo Green and his date arrived at the show decked out in all sparkles and made their way through the Staples Center crowd together. In a sweet fan-girl moment, Miley Cyrus' godmother Dolly Parton raised her hands in the air while the "Nothing Breaks Like a Heart" singer performed alongside Shawn Mendes.
Tracee Ellis Ross also busted out her best moves during Miley and Shawn's beautiful performance and rocked out in the front row of the show.
Lady Gaga, who had just won the award for Best Pop Duo/Group Performance, danced along to Janelle Monae's performance, too. She even got everyone else in her row to get up and start dancing, including Mark Ronson!
Host Alicia Keys' husband Swizz Beatz chatted with Key's mom at one point and shared a huge laugh.
Meghan Trainor and her husband Daryl Sabara bopped along to Post Malone's set that he did with Red Hot Chili Peppers. Other attendees who loved Posty's performance include Ashlee Simpson, Evan Rossand Miguel and his wife Nazanin Mandi.
Katy Perry brought out a Hello Kitty mirror to check her makeup before getting ready to perform with Kacey Musgraves.
The crowd at the Grammys absolutely loved H.E.R.'s performance, too, and understandably so. Swizz Beatz, Robin Thicke, Ricky Martin and Chloe and Halle were dancing to the words during her set.
Sisters Noah and Miley Cyrus rocked out to Lady Gaga's "Shallow." Miley seemed the know every word to the song and stood with her arm linked in Noah's.
Later on in the show, the Grammys host gave a spectacular mash up on songs, which she sang not long after Cardi B's epic performance that involved twerking on a piano and much more. Keys watched Cardi's entire act and waved her hands in the air while doing so.
The "No One" singer stunned the crowd while she played not one, but two pianos! Her husband was loving every moment, just like everyone else in the crowd. When she finished the medley of songs, Keys jumped up and down backstage with some of her crew. Her entire band cheered and celebrated with her, too.
Like other award shows of the past, A-Rod looked like his girlfriend J.Lo's biggest fan as she sang beautifully onstage during the Motown tribute. He had a huge smile on his face and nodded his head along to the music. He gave everyone around him hugs when it was all over. Similarly, Maren Morris got up out of her seat and swayed to the songs. On the opposite end of the spectrum, Post Malone looked a little bored during the tribute and sat sipping his drink.
Once back in their seats, Offset put his arm around his wife and they two snuggled up a bit during Brandi Carlile's performance. At one point, the Migos rapper kissed her shoulder.
Dua Lipa took home the trophy for Best New Artist, and Gaga was here for it. She cheered super loud for the "New Rules" singer and blew kisses at her after Lipa's speech got cut off at the end. Around this same time, Post Malone got up and ran through the aisle.
Posty truly seemed to be having the most fun of the night. He shared a huge bear hug with Swizz Beatz and the music producer whispered something into Malone's ear. The "White Iverson" artist got onstage after the show with a cigarette in his hand and took lots of photos with fans. The Joanne artist also stood onstage and high-fived fans.
What a night! This year's show was filled with talented musical acts, tributes and more. Make sure to check out the complete list of winners here.


Hypotrichosis is a very common problem. The phenomenon of losing hair from a particular region of the body like eyelashes, eyebrows, and often scalp. This magical potion is regularly used by celebrities like actresses and models to enhance their appearance. Latisse is usually recommended to be purchased with prescription from a cosmetic surgeon but a very feasible option is to purchase latisse without a prescription. The generic name for latisse is bimatoprost. This medicine is an analog/prod rug of prostaglandins to reduce hyper ophthalmic pressure and treat glaucoma. It reduces intraocular pressure by easing the flow of the aqueous fluid of the eyes. It is a topical drug in the solution or serum form. Each pack is substituted with a number of applicators. One applicator is used per eye per day. The same should not be used for both eyes. It must be discarded after used once.
Where To Buy Bimatoprost online?
The best way for latisse is to order for eyelash growth is than from any specialized pharmacy. The hassle can be avoided by the click of a button using the internet services. There are a variety of generic bimatoprost available with best combinations and offers. It does not matter how much you buy but where to buy latisse has just one destination. The whole experience is very fulfilling. It is very easy to select the drug. If you are unsure about the dosage, then just ping the available customer care execute in the chartroom. They can explain you in details, especially regarding the pros and cons of the drug, the application process, safety, storage, etc.
What Is The Secret Behind The Success of Bimatoprost?
The 85% raise in the sales in the recent past credits the success of bimatoprost. The users claim that they are extremely satisfied with the product. There are millions of uses with billions of packets sold each year in the United States alone. The nearly no harmful side effect gives huge thumbs up to the researchers to introduce the product to the society. The result is phenomenal as in about eight weeks time one can get thicker, fuller and longeyelashes than the ones they were born with. So, no need to spend your money on those expensive eye products and fake eyelashes.
Hypotrichosis is a genetic disorder and can never be completely cured except for gene therapy, just like ageing. It can be controlled by a drug but it can never revert back to being normal. So, if you want to keep enjoying those luscious long eyelashes, continue using them. As soon as you stop the serum you will notice the depletion in the eyelash growth. One must always store the serum in a cool place. The information leaflet must be read very carefully and if there are any doubts, just contact the online customer care executives. Currently, this drug is being tested for other possible uses like for treating male pattern baldness. Bimatoprost is not recommended for children. As it is a topical drug, thus it does not interfere with your medicines for chronic illness.
The herpes virus will not basically be completely rooted out of skin but the Valacyclovir medicine for herpes will slowly and steadily target the affected area. Let us look in detail how this medicine treats the herpes.
Target the skin cells on which there is some abnormity. The deformations like tingling, red spots, and uneasy structures are the result of herpes virus residing in your skin layer. Any of herpes treatments first of all targets the core issue that is herpes spreading. The growth herpes virus can be arrested by use of Valtrex medicine as it makes a shield for the other skin in such a way that herpes virus cannot approach new areas of skin.
Basically, this medicine for herpes makes the skin anesthetic while making it sedative at the same time. Thus the herpes treatments starts this way, first slowing down the spreading of herpes virus which ultimately makes it lesser and lesser till it is eliminated.
Herpes can also be treated with proper isolation of herpes affected area from other body parts. For example, you touch the affected part of skin then touch on other area like eyes etc. will hasten the growth of herpes virus and herpes treatments will receive a major blow.
"Does this prevent spread of herpes?" There are more questions like that adds to the controversies about herpes. Basically, we all know that every medicine has its critics just for surplus reasons. Now the question "Does this prevent spread of Herpes?" is totally baseless because we all know the answer that this is specially designed medicine for herpes treatments. More fuel to the controversy is added by the it's side effects that are part & parcel of the every Valacyclovir medicine consumed.
Also, there was a growing concern that people order online, no prescription whatsoever is done. Does it mean it is harmful for people? The physicians have settled for one view that it is safe to order valtrex online, no prescription is required.
There was a time when people used to cure their insomnia by taking drugs. There are many drugs available that treat you with insomnia that is, lack of sleep. Now there are times when people need drugs to "avoid excessive sleeping." In some work profiles, it is mentioned that you should be flexible with rotational shifts that can include night shifts, day shifts any time. This makes the sleeping duration in mess, and such people are fatigued all the time.
Just take the case of Alex Hughes, the call center executive in Detroit, who works in rotational shifts. He says only thing that is helping him with his job is the nuvigil drug. Okay, let us tell you how the Armodafinil drug is helping Alex with his job. Let's see what he says.
"I was very happy when I got a high paying call center job. But the shady deal was I had to compromise with my sleep. The night shifts are really very hectic. I used to sleep on the desk itself, even while on-job. My body started feeling exhausted and all I needed was to sleep all day and night. I even took two days comp-off. But the same problem continued after I joined after couple of days. I had to do something with my sleep. It was affecting my work. I went to my doctor. He suggested me nuvigil dosage per day three hours before the night. The day I took the pills, at night at work, I wondered where I got this energy from. Previously by that time, I used to be all down and my eye-lids always fighting to come down. But from that day onwards, I am better performer now as sleep is miles away. Also, it makes me feeling refreshed. I am also planning for Armodafinil weight loss pills once I get used to this. The best part is I never did really face any Armodafinil side-effects because I paid the nuvigil cost for a genuine and authentic waklert drug. Also, I stick to the adherent guidelines by not crossing the nuvigil dosage level."
Thus, the Armodafinil dosage plays very important role in treating work shift disorder. That should be strictly followed and only taken after doctor's recommendation. The Armodafinil side-effects are not very frequent because this smart drug is considered a safe bet for everybody, not everybody there are some exceptions in it.
See, there are different types of disorders that are treated with this drug. Given the nuvigil costs have also been reasonable recently, more and more chemists are selling the prescribed waklert drug. The basic nuvigil dosage 150mg or 250mg in the morning, a single dose per day. This is the general recommended dosage for nuvigil. However, one can check with the doctor if any alterations can be made in the Armodafinil dosage.
In many countries in the world like USA, UK, Canada, one needs to get a medical prescription by licensed doctor for purchase of medicine for sleep disorder. The online this drug market in fore-mentioned countries is very saturated as there are lot of customer slooking for provigil buy online.
Are provigil really smart drugs that are naturally safe?
The biological enhancements in your body by use of this are worth mentioning and amazing. This medicine order online are in great demand only due to the fact that the this drugs are really very smart drugs. Not only very smart drugs, they are naturally safe too. This drugs can be consumed by normal adults every day and the dosage permitted is 100 mg to 250 mg. This are the safe limits for the drugs if you have medicine after ordering online and haven't read the leaflet.
Even small dosage of this can be very powerful.
Keep the this dosage to minimum till you do not feel accustomed with it.
The active agent known as Adrifinil, that is present in waklert as well, is the source of chemical reactions that takes place in your nervous system after consumption.
Adrifinil gets converted into modafinil ingredient after the former has been properly absorbed and digested by the body.
Online provigil drugs are available in various mg quantities varying from low to high power.
Online drug providing stores may provide you the half information about the product, in order to sell the esteemed drug. It is therefore, your compulsion to check with the doctor or get the authentic information.
There are few online medicine providers allowing you to buy smart drug online without prescription, although they can be taken, but doctor's advice is always handy.
Buying modafinil online with genuineness is not very simple as you think. You need to do a lot of research before placing modafinil order online. What type suits you, what is the desired quantity and others stuff.
If you plan to purchase medicine online, the basic question that comes to mind is where to buy provigil online? There are number of online portals that offer cheap modafinil online. Before placing a modafinil order online, check out your medical condition with your doctor whether you are permitted to drugs buy online.
This treats the syndrome called obstructive sleep apnea, narcolepsy, and hypopnea, thus getting you feel rejuvenated and refreshed all the time. The question is, who uses the provigil drug?
This drug has been become the first-choice drug for businessmen, and high-post employees. It is one of the drugs that 'claims' to keep you in the best state of mind possible. And you know what the best part is, (or the worst part, whatever) is its legalization in many parts of the globe. Due to this, anyone can buy this online any time whenever required. Has this over-stardom of buying this medicine online created negative impact in our society?
One cannot shoo away from the endless debates about provigil. The online pharmacy industry is growing at a very rapid place. It is wondered by critics why this buy online trend has attracted lot of youngsters? Yes, the marketing strategy can be possible where to buy Modafinil online has become such a great phenomenon among young students.
Shaun A. Garson, medical researcher & analyst from Toronto, conducts the research on various types and calculates its cumulative analysis on long term effect of the drug in our population. He has conducted many surveys on online pharmacy industry and also on the trends on how one comes to the point to order provigil online.
But the main target group that forms a chunk of group that are buying Modafinil online are working professionals, who want to abstain from sleepiness. But the it controversies refuses to bog down. The critics say that making Provigil online available so easily is not worth it. The upcoming generation will be ordering this online even for non-existing reasons. It is not good for any generation to thrive only on drugs, because at some point, they are fabricated and man-made. They also slam the online pharmacy providers for promoting the 'Modafinil buy online' crusade that is adding more and more buyers of this day by day.
Where to buy Modafinil online?
The doctor prescribes you to buy Modafinil from certified local drug store or to buy Modafinil online. You can search on the internet where to buy Modafinil online. It will give you a list of online this providers according to your location. If you turn your location feature on, it can show plenty of related places where to buy Modafinil online.


text:
San Diego Comic-Con Scheduling Begins: Wednesday & Thursday Highlights Include 'Arrow,' 'Twilight,' 'Oz,' 'Expendables' And More
Posted on Thursday, June 28th, 2012 by Germain Lussier
It's coming. San Diego Comic-Con 2012 is mere days away, kicking off Wednesday night July 11 for preview night and then getting into full gear Thursday July 12. If you can believe it, this year, more than others, is jam packed with goodness, even with studios like Paramount generally bowing out. Movie panels have spilled into neighboring hotels, TV panels have finally cracked Hall H (on days before Sunday, which was once the TV day in H) and more.
Below, we'll link to the full schedule and also pull out the Movie and TV related highlights for Wednesday and Thursday. Check back the rest of the week for the rest of the schedule, which includes Iron Man 3, The Hobbit, Man of Steel, Breaking Bad, Game of Thrones and much more.
Head to the Comic Con site to see the full schedule of amazing events. Here are just a few highlights for Wednesday and Thursday.
6:00-9:45 Wednesday Special Sneak Peek Pilot Screenings— Comic-Con and Warner Bros. Television proudly continue their annual Preview Night tradition, with exclusive world premiere screenings of the pilot episodes of five of the most highly anticipated TV series pilots of the 2012–13 television season: 666 Park Avenue, Arrow, The Following, Revolution and Cult. Ballroom 20
11:15-12:00 DreamWorks Animation— DreamWorks Animation's chief creative officer Bill Damaschke anchors a diverse group of filmmakers to demo and discuss the artistic ambition and technical innovation that goes into moviemaking at DreamWorks Animation. Moderated by Anthony Breznican fromEntertainment Weekly.Indigo Ballroom, Hilton San Diego Bayfront
12:45-1:45 The Twilight Saga: Breaking Dawn-Part 2— Summit Entertainment presents a sneak peek at the highly anticipated conclusion of The Twilight Saga films. This is a must-see for fans interested in the story's final chapter. You will be shown exclusive footage from The Twilight Saga: Breaking Dawn-Part 2 and be treated to a cast and filmmaker Q&A session providing details on the epic finale. Hall H
2:05-3:05 Walt Disney Studios: Frankenweenie, Oz The Great and Powerful, andWreck-it Ralph— Walt Disney Studios hosts a Q&A panel featuring the imaginative director ofFrankenweenie, Tim Burton (Alice in Wonderland); a special look at the world of Oz The Great and Powerful with director Sam Raimi (Spider-Man trilogy); and the illustrious voice cast of Walt Disney Animation Studios' Wreck-It Ralph, including John C. Reilly (Step Brothers) andSarah Silverman (The Sarah Silverman Program), and director Rich Moore (Futurama).Hall H
3:00-4:00 Hotel Transylvania— Welcome to Hotel Transylvania, Dracula's lavish five-stake resort, where monsters and their families can live it up, free to be the monsters they are without humans to bother them. On one special weekend, Dracula has invited some of his best friends-Frankenstein and his bride, the Mummy, the Invisible Man, the Werewolf family, and more-to celebrate his beloved daughter Mavis's 118th birthday. For Drac, catering to all these legendary monsters is no problem-but everything could change for the overprotective dad when one ordinary guy stumbles upon the hotel and takes a shine to Mavis. Animation superstar Genndy Tartakovsky, who previously created Dexter's Laboratory and Star Wars: Clone Wars, among other projects, takes the helm of this project for his first feature film, and takes the stage to tell you all about it. Indigo Ballroom, Hilton San Diego Bayfront
4:00-5:00 Wilfred: Screening and Q&A— Elijah Wood (Lord of the Rings) stars as Ryan, a young man struggling unsuccessfully to make his way in the world until he forms a unique friendship with Wilfred, his neighbor's canine pet, played by Jason Gann (The Wedge), who co-created and starred in the Australian version of Wilfred in 2007. While everyone else sees Wilfred as just a dog, Ryan sees a crude and surly man in cheap dog suit. Elijah and Jason join Wilfred co-stars Fiona Gubelmann (Don't Trust the B** in Apt 23), and Dorian Brown(Roommates) as well as showrunner/executive producer David Zuckerman (Family Guy) and executive producer/director Randall Einhorn (The Office) to discuss bringing this unique live-action comedy to life. Indigo Ballroom, Hilton San Diego Bayfront
4:30-5:30 Masters of the Web— The annual gathering of some of the most prominent and influential film pundits on the web discuss the film industry, writing for film online, film fandom, and a whole lot more. Moderated by star of the new Lionsgate film Dredd, Karl Urban(Star Trek, Lord of the Rings: Return of the King), with special surprise cast members from the film. Panelists include Mike Sampson (ScreenCrush.com), Jen Yamato (MovieLine.com),Mali Elfman (ScreenCrave.com), Erik Davis (Movies.com), Steve "Frosty" Weintraub(Colider.com), Grae Drake (Fandango.com), Jenna Busch (Cocktails with Stan Lee), andEdward Douglas (ComingSoon.net), and hosted by John Campea (AMC Theatres). AMC is generously providing free movies passes to all attendees of the panel this year! Room 24ABC
4:45-5:45 The Expendables 2-Real American Heroes— Sylvester Stallone and the legendary cast of the sequel to 2010's smash hit film preview the real-deal muscles, weapons, skills, and explosions that went into making a film even bigger and badder than the original.Terry Crews, Randy Couture, Dolph Lundgren, Jean Claude Van Damme, and Arnold Schwarzenegger will join the panel discussion. Hall H
6:15-8:15 The Virtual Drive-In— Come with us again to those thrilling days of yesteryear where one of the few places you could see offbeat genre films was at your local drive-in, huddled safely in your car as the summer sky darkened around you. At least that was the germ of an idea that gave birth to this panel last year, and the reception by those fans who attended was so positive they're doing it again. So, welcome to the second edition of the Virtual Drive-In, where you will preview three twisted tales by some talented filmmakers who will all be appearing on the panel to discuss their work and take your questions. Moderated byRobert Meyer Burnett. The featured films are: Branded, Crave, Coldwater. Hall H
7:00-8:00 Inside The Batmobile— No vehicle has ever captured fans' imagination like the Batmobile. Be the first to see an exclusive Comic-Con, 22-minute sneak peek at the upcoming documentary The Batmobile, an in-depth examination of its many incarnations and impressive history. A panel discussion will follow the screening featuring distinguished Batman expertsGeorge Barris, designer of the famed 1966 Batmobile; Andy Smith, builder of the modern-day Dark Knight "Tumbler"; respected producer/author Michael Uslan (The Boy Who Loved Batman); Ralph Cirella and Jon Hein, hosts of GEEKTIME! Sirius-XM Howard 101; and a few surprise guests. Stay to the end, when a drawing among all panel attendees will determine which lucky five fans can sit in a Batmobile-which is on display all weekend in the "Batcave" between Hall H and the Bayfront Hilton. Room 6DE
8:30-10:00 Dr. Horrible's Sing-Along Blog Sing-Along— Join the fun as the California Browncoats screen Internet sensation Dr. Horrible's Sing-Along Blog-coming back with call back sheets so you can play along during the screening. Enter our costume contest: horrible prizes awarded to the best version of each character from the show. DO NOT BOUNCE.Room 6BCF
8:30-10:30 Comic-Con Episode IV: A Fan's Hope— San Diego Comic-Con premiere screening of the ultimate fanboy documentary from executive producers Stan Lee, Joss Whedon, Harry Knowles, and Thomas Tull. Q&A to follow with director Morgan Spurlock(Warrior Poets) and special surprise guests. Ballroom 20
/Tweeted, Comic-Con,


text:
Biografia
Gianluca Barbera è nato a Reggio Emilia il 15 febbraio 1965. Ha trascorso l'infanzia e l'adolescenza a Correggio per poi trasferirsi per alcuni anni a Milano e stabilirsi definitivamente a Siena, tra le colline del Chianti. Ha compiuto studi giuridici e filosofici. Ha cominciato a lavorare in ambito editoriale nel 1995, prima alla Logos Edizioni, poi alla Alpha Test. Nel 2000 è stato tra gli ideatori di Sironi Editore insieme con Giulio Mozzi. In seguito ha fondato e diretto fino al 2015 la casa editrice Barbera Editore. Nell'ottobre 2015 ha costituito Melville edizioni

Dal 2016 al 2018 è stato direttore editoriale di Edizioni Theoria.

Attività letteraria
Nel 2011 ha pubblicato Il dittatore utopista, biografia anno per anno di Muammar Gheddafi. Del 2014 è Storia di Anna Frank (Rusconi Libri).

Sempre nel 2014 ha pubblicato il romanzo filosofico Finis mundi (Gallucci editore) e nel 2015 il volume di riflessioni filosofiche Breviario universale (Barney edizioni). Nel 2016 ha dato alle stampe il romanzo picaresco La truffa come una delle belle arti, col quale è stato finalista al Premio Neri Pozza (2015), finalista al Premio Letterario Chianti (2017) e finalista al Premio Internazionale di Letteratura Città di Como (2017).

Nel gennaio 2018 ha pubblicato il volume di interviste filosofiche Idee viventi. Il pensiero filosofico in Italia oggi. A maggio dello stesso anno ha dato alle stampe Magellano, romanzo che ha riscosso un successo di pubblico e di critica e che racconta la storia della prima circumnavigazione del globo. Con questo romanzo Barbera si è aggiudicato il Premio Nazionale di Narrativa e Poesia Città di Fabriano (2018), il Premio come miglior romanzo storico al Premio Internazionale di Letteratura Città di Como (2018), il Premio Scrittori con Gusto, il Premio Marincovich, il Premio La cultura del mare ed è risultato finalista al Premio Costa Smeralda e al Premio Acqui Storia. È stato inoltre candidato al Premio Strega. "Magellano" è stato tradotto in Portogallo e in Brasile ed è oggetto di una trasposizione teatrale con la voce narrante di Cochi Ponzoni e le musiche di Luca Garlaschelli. Nel 2019 ha pubblicato il romanzo "Marco Polo", liberamente ispirato alla vita e alle avventure del celebre esploratore veneziano, miglior romanzo di avventura al Premio Città di Como.
Del 2020 è il romanzo "Il viaggio dei viaggi" (Solferino) e del 2021 il romanzo "Mediterraneo" (Solferino), che è stato insignito del Premio Emilio Salgàri 2022. Nel 2022 sono usciti "L'ultima notte di Raul Gardini" (Chiarelettere), che ha ottenuto grande attenzione da parte del pubblico e della critica, "Magellano e il tesoro delle Molucche" (Rizzoli), romanzo avventuroso per ragazzi, sulle orme dei grandi classici di avventura, da Stevenson a London e Salgari, e "Atlante dantesco. I luoghi di Dante e della Divina Commedia" (Rizzoli). Del gennaio 2023 è il romanzo d'inchiesta "Il segreto del Gran Maestro" (Chiarelettere) mentre di marzo è "Se il diavolo" (Polidoro), immaginaria biografia di Georges Simenon con tanto di patto col diavolo.

Barbera è altresì autore di numerosi racconti apparsi su riviste e quotidiani ("Fernandel", "Maltese Narrazioni", "'tina", "Inchiostro", "Ellin Selae", "Achab", "succedeoggi.it", "linkiesta.it", "globalist.it", "pangeanews.it", "il Giornale") e in antologie (Giovani cosmetici, a cura di Giulia Belloni).

Collabora alle pagine culturali del "Giornale" e del Sole24Ore.com, e scrive di letteratura sulle riviste on-line "Pangea" e Letteratitudine". Suoi articoli sono apparsi inoltre su "La Lettura-Corriere della Sera", "Robinson-la Repubblica", "Domani" e "Il Resto del Carlino".

Opere

Romanzi

 Finis mundi (Gallucci editore, 2014)
 La truffa come una delle belle arti (Aliberti compagnia editoriale, 2016, finalista al Premio Neri Pozza, finalista al Premio Letterario Chianti, finalista al Premio Internazionale di Letteratura Città di Como)
 Magellano (Castelvecchi, 2018, vincitore del Premio Nazionale di Narrativa e Poesia Città di Fabriano, premio speciale come miglior romanzo storico al Premio Internazionale di letteratura Città di Como, Premio Scrittori con Gusto, Premio Marincovich, finalista al Premio Costa Smeralda, candidato al Premio Strega, Premio La cultura del mare, finalista Premio Acqui Storia)
Marco Polo (Castelvecchi, 2019, Miglior romanzo di avventura al Premio Internazionale di letteratura Città di Como)
La leggenda di Jesse James (Stampa Alternativa, 2019)
Il viaggio dei viaggi (Solferino, 2020, Finalista al Premio Acqui Storia, Finalista al premio Città di Como)
 Mediterraneo (Solferino, 2021, Premio Emilio Salgàri)
L'ultima notte di Raul Gardini (Chiarelettere, 2022)
Magellano e il tesoro delle Molucche (Rizzoli, 2022)
Se il diavolo (Alessandro Polidoro Editore, 2023)
Il segreto del Gran Maestro (Chiarelettere, 2023)

Racconti

 Zio Tibia ("Fernandel" n. 3/2002)
 Denti marci ("Il Maltese Narrazioni" n. 29, anno 2002)
 Viaggiare che bellezza ("'tina", 2002)
 Africa mia! ("Fernandel" n. 1/2003)
 Autoritratto con padre ("Fernandel", n. 1/2004)
 L'orchestra di Edipo ("Fernandel" n. 1/2005)
 Non voglio del romanticismo (Giovani cosmetici, a cura di Giulia Belloni, Sartorio, 2008)
 Il terrore ("il Giornale", 15 agosto 2015)
 Cani infernali ("succedeoggi.it", 2015)
 Giustizia è fatta ("Achab" n. 5/2016)
 Robinson Crusoe ("Il Giornale", 13 maggio 2020)

Saggi e varia

 Il dittatore utopista (BE, 2011)

 Storia di Anna Frank (Rusconi Libri, 2014)
 Idee viventi. Il pensiero filosofico in Italia oggi (Mimesis, 2018)
 Atlante dantesco. I luoghi di Dante e della Divina Commedia (Rizzoli, 2022)

Premi e riconoscimenti

 2015 - Finalista al Premio Neri Pozza
2016 - Finalista al Premio Internazionale di Letteratura Città di Como
2017 - Finalista al Premio Letterario Chianti
2018 - Premio speciale come miglior romanzo storico al Premio Internazionale di Letteratura Città di Como
 2018 - Premio Nazionale di Narrativa e Poesia Città di Fabriano
2019 - Premio Scrittori con Gusto
2019 - Premio Marincovich
2019 - Finalista al Premio Costa Smeralda
2019 - Candidato al Premio Strega
2019 - Finalista Premio Acqui Storia
2019 - Premio La cultura del mare
2019 - Premio per il miglior romanzo di avventura al Premio Internazionale di letteratura Città di Como
2020 - Finalista Premio Acqui Storia
2020 - Finalista Premio Città di Como
2022 - Premio Emilio Salgari

Note

Voci correlate
 Sironi editore
 Giulio Mozzi
 Barbera editore
 Rusconi Libri
 Fernandel
 II Giornale
Premio internazionale di letteratura Città di como
Castelvecchi Editore
Mimesis
Linkiesta

Collegamenti esterni
La truffa come una delle belle arti


Here you can view a huge range of replacement ink pads of all sizes. All of our ink pads are made with the highest quality materials and are great prices. Customers can simply choose the ink pad they require and follow the simple steps in to purchase it online. WE have a huge range of different colour ink pads to fit in to every machine brand. Our replacement ink pads are available all year round and so we always have what you need. Finally, if you have any problems using the site just give us a call. We'll be happy to help.


text:
Q: How to prevent certificate pinning failure in an Azure Mobile App on iOS? Based on recommendations from a security firm, we hardened our iOS mobile app against man in the middle attacks by implementing certificate pinning.
This week, my app began failing, with error: -999 failures, with the app reporting that the HTTP calls were cancelled. Subsequent investigation seems to show the problem to be that Microsoft updated their SSL certificates for *.azurewebsites.net.
Here's part of the old certificate I had pinned in my app:
Subject Name
    Common Name: *.azurewebsites.net

Issuer Name
    Country: US
    State/Province: Washington
    Locality: Redmond
    Organization: Microsoft Corporation
    Organizational Unit: Microsoft IT
--> Common Name: Microsoft IT SSL SHA2

Here's that same part for the new certificate I pulled tonight:
Subject Name
    Common Name: *.azurewebsites.net

Issuer Name
    Country: US
    State/Province: Washington
    Locality: Redmond
    Organization: Microsoft Corporation
    Organizational Unit: Microsoft IT
--> Common Name: Microsoft IT TLS CA 4

The Not Valid Before and Not Valid After dates are also different (newer certificate runs from 12/17/2017 thru 12/17/2019).
Fortunately, we haven't yet rolled out app out live to customers (but we're close, so this is scary). Obviously, this kind of service shut down once we have customers is completely unacceptable.
My question is: how can I avoid this issue biting me in the future?
I can think of 2 potential solutions, but I'm not sure exactly how Microsoft updates their certificates, and I can't find any information about that (my Google-fu might perhaps be lacking tonight).

*

*Solution 1: Learn when Microsoft will be updating their certificates and grab the new one as soon as it's released, putting it in my app ASAP.

*Solution 2: Provide my own SSL certificate that's pinned in the app.

Solution 1 seems problematic, as I can't currently find any information on when/how/why Microsoft updates these certificates, and given that it was less than 3 days from the new cert being issued before the old cert was inoperable, I just don't see this as a valid solution.
Solution 2 seems more attractive, as it would seem to place this more under my control, but I'm unclear on how I could do it. I can't issue a certificate against one of Microsoft's addresses. Do I issue it over a domain I control and set up some kind of forwarding to Microsoft's service?
Can someone give me the best, most secure way to accomplish this? I'm open to a "Solution 3", if I have missed something.

redpajama_set_name: RedPajamaStackExchange


Here are some fascinating new translation stats.
"How many translations are published in English and how accurate is the often quoted figure of 3%? Which are the most translated languages and which literatures are we missing out on? A new report from Literature Across Frontiers (LAF), Publishing translated literature in the United Kingdom and Ireland: 1990 – 2012, finally answers many questions surrounding translation statistics. The report, prepared by Alexandra Büchler and Giulia Trentacosti, is a welcome addition to the translation reports and surveys published on LAF's website and will be launched in electronic format on Monday 13th April, on the occasion of the London International Book Fair 2015.
The key findings presented by the report are based on analysis of two distinct data sets: raw data extracted from the British National Bibliography for the period 1990 – 2012 and processed data for the period 2000 – 2012. The raw data make it possible to produce statistics comparable to those published by other book markets, while the manually processed data provide an annual list of literary translations comprising fiction, poetry, drama, children's books and creative non-fiction, so far for the period 2000 - 2012. The processed data sets have been further analysed with respect to genre and source language.
Thanks for sharing the informaton.


text:
Community group announces call to action to end local violence
by Jim E. Winburn • January 30, 2015
TCAL co-founder Pharaoh Mitchell speaks at a press conference Jan. 29 outside the Antelope Valley Courthouse to address violence in the community. (Photo by Jim E. Winburn)
LANCASTER – The Community Action League held a press conference at the Antelope Valley Courthouse Thursday to recruit local participation in the fight against violence.
TCAL co-founder V. Jesse Smith told the handful of people gathered outside the courthouse that members of the community must add to the solutions to stop senseless acts of violence in the Antelope Valley.
"A young man, striving to become a musician, was killed in his garage because of reckless shooting – unnecessarily. Palmdale High School vandalized – unnecessarily," Smith said. "We got to decide at this point to take a stand. We rise up when racism is strong in this community, so we must also rise up when violence rears its ugly head in this community."
Though recently published crime statistics for the city of Palmdale show the crime rate to be at its lowest in the past 20 years, some in the community remain vocal regarding the visibility of violence throughout neighborhoods.
The latest murder took place in Lancaster Jan. 17, when 30-year-old Johnnie "June" Jones III was shot to death after an argument in the 45400 block of Corkwood Avenue.
"This right here is a travesty," league co-founder Pharaoh Mitchell said at the press conference. "This senseless violence that is going on in our community should not be going on. We have to be here to protect our community, and unnecessary crimes like this should not be going on."
Although Lancaster officials introduced an Administration Citation Program on Tuesday to counter what is seen as an increasing criminal impact on local businesses and residents, The Community Action League proposed a different approach to take their community back from violent offenders.
TCAL members outlined a few strategies and programs that would require participation from residents and stakeholders to combat local violence, such as forming a Community Violence Intervention and Prevention Committee to address the needs of families impacted by violence.
"Another one would be to call upon the municipalities, both Lancaster as well as Palmdale, and most importantly our county officials, to begin to identify possible resources to create a Violence Reduction Department in both municipalities that will partner with local CBOs (community based organizations) so we can begin to strategize to reduce violence in our communities," Ansar "Stan" Muhammad announced.
The league stated in their press release that the proposed Violence Reduction Department would be similar to the Los Angeles-based model of the Gang Reduction Youth Development Department, while suggesting the organization would be funded by Palmdale and Lancaster.
Members of the league also recognized the importance of working with law enforcement in the ongoing effort to make neighborhoods safer.
"We can't just hope that law enforcement will take care of this problem. This is not just a law enforcement problem – this is a community problem," Mitchell said. "If you're not reporting these crimes, you're just as guilty as the person committing these crimes. Do not condone any violence in any form in our community."
Emmett Murrell, executive director of Murrell's Farm and Boys Home, said the greatest strategy for reducing violence is to embrace the community's future through its next generation of leaders.
"I think it's paramount that we pull together the young men who can have a positive impact on the maturation of the youngsters as they begin to develop and become stakeholders of the community where they have been too long without," said Murrell. "We're hoping as a result of this, we're setting up opportunities for them not only to further their education but to get the kind of skills that are going to be needed."
TCAL is hosting an upcoming town hall meeting in Palmdale to provide more details about their goals and programs, while seeking input from the public on how to prevent crime in the community.
The town hall will take place at 6:30 p.m. Wednesday, Feb. 4 at the Larry Chimbole Cultural Center, 38350 Sierra Highway in Palmdale.
Jim E. Winburn is freelance reporter covering news of public interest.
Filed Under: Lancaster, Palmdale
14 comments for "Community group announces call to action to end local violence"
Son of the Anti Rex says
This organisation loses credibility with a homophone and anti Semite like Stan Muhammad at the helm. How can they be taken seriously with that type of person in leadership?
War Monger says
How about attacking:
Welfare Fraud
Disability Fraud
Food stamp Fraud
Fatherless families
Deadbeat Dads
Junior High Gangsters
Mothers without a Wedding Ring
Black "Leaders" getting in the Game for the Money
Our Ghettos
Pimps
Bad Teachers
Bully Cops
TERRY JONES says
YOU SOUND LIKE A RIGHT WING REPUBLICAN RACIST
Shadow says
Terry Jones:
Not a racist. I think black leaders need to look within the black community and reform the culture rather than trying to say that blacks are victims of outside forces that need to be reformed. Black culture is a mess and just trying to turn the blind eye to that is disingenuous.
351 says
Is that the chump from J & Challenger with the news papers? Sucka… He will never give me a paper or a bean pie! Not sure why though. It can't be because I happen to be Caucasian because racism is wrong. Right? Or is it only wrong when white people practice it? Brown Pride… Not racist. Black Power… Not racist. Black college… Not racist. Black History Month… Not racist. Miss Black America. .. Not racist. . I stand by the truth that the WHITE, CHRISTIAN, HETEROSEXUAL, AMERICAN MALE is the most discriminated upon person on the modern day Earth-
done says
How can this TCAL group expect anyone to take them seriously when they associate with nation of islam goons?
I WENT SCHOOL WITH JUNE… HE WOULD BE MISSED
I FEEL SORRY FOR HIS FAMILY….
Wasn't there an article here in the AV Times stating that the crime rate in Palmdale has gone down? Yup that's right,,,, and elephants can fly!
Doc Rivers says
I love it, bring South Central LA solutions while spending other peoples money. This group is in search of a cause besides being part of a Justice Dept. lawsuit against both cities costing taxpayers millions of dollars. Lets see who runs for political office out of this group.
Marquez says
Open your eyes people, look who's comitting the crimes here in the AV. I love living here in North Central LA. Keep brining in the scum.
eris says
The black ppl just no one wants to say it
Marq says
Thank you very much, it's about time someone said the truth!!!!
TiredOfIdiots says
It's not just black people idiots! It's Hispanics, Whites, Blacks etc committing crimes! You sound so stupid and rascist!
Truth says
"Even allowing for the existence of discrimination in the criminal justice system, the higher rates of crime among black Americans cannot be denied," wrote James Q. Wilson and Richard Herrnstein in their classic 1985 study, "Crime and Human Nature." "Every study of crime using official data shows blacks to be overrepresented among persons arrested, convicted, and imprisoned for street crimes."
Read more: http://www.washingtontimes.com/news/2014/jul/21/family-secret-what-the-left-wont-tell-you-about-bl/#ixzz3RJ6ITGMN
Follow us: @washtimes on Twitter


With April in full swing, many people are already basking in the sunshine and thinking about the summer ahead. For some, it feels as if the fresh spring air is symbolic of a fresh start. So, of course, one of the most popular activities to partake in, at this time of year, is "spring cleaning". Getting set for the summer by getting rid of the clutter can help invigorate you and feel renewed.
Many believe that when you unclutter your physical surroundings, it helps to clarify your goals and better prepare you for your next step. Organization is key to running a successful business. Gregory lists a number of steps that can be taken so that your business can utilize the concept of spring cleaning to clear a path to a brighter future.
"Clean of your desk", she writes. The simple task of having a neat and tidy workstation will ensure that your assignments are completed free of distraction. Sometimes, employees get caught up in what feels like an overwhelming number of different projects simply because they cannot remember just how many they have to complete. Unkept files and miscealleaneous documents strewn all over a desk is only cause for confusion.
Ensuring that you are organized will help you stick to a schedule that will allow time for all of your tasks to be completed. Gregory writes that workers should "get rid of 'rolling' tasks by getting them done, delegating the work or removing them from your list entirely." Procrastination, evidently, is an example of clutter and disorganization.
Keeping your contact list up to date, sometimes means making contact with those on the list. "Touching base" helps your clients remember that you haven't forgotten them. This encourages loyalty in addition to potentially re-opening doors for further business with these clients.
"Schedule a meeting with a colleague, or even competitor, to explore a collaborative effort," says Gregory. Sometimes the creation of a new project or joint venture is just what is needed to provide that extra boost to your company during the advent of a new season.
Of course, there are many ways that businesses can being their own spring cleaning regiments. If you haven't begun yours yet, you might want to get to it. You may just find that it will help for your upcoming summer to be your most successful season yet.