text:
\section{Introduction}
The problem of spin injection has been a subject of intense study since the
proposal of the electronic analog of the electro-optic modulator. \cite{datta}
Since then the entire field of spintronics has been developed. The main idea
lies in the possibility of controlling the spin of charge carriers, thereby
adding an additional degree of freedom to existing semiconductor-based
electronics.
A number of novel electronics devices based on this idea have been proposed,
such as reprogrammable logic devices, spin valves, spin-injection
diodes, and devices utilizing giant magnetoresistance
(see, for instance, Ref. \onlinecite{spintronics}).
A major challenge in the field has been the creation of spin-polarized
currents in nonmagnetic semiconductors.  One  approach is the use of
ferromagnetic contacts as spin sources.  A spin polarization of the
current is expected from the different conductivities resulting
from the different densities of states for spin-up and spin-down
electrons in the ferromagnet.
Significant progress in molecular beam epitaxy  has allowed
growth of high quality, virtually defect-free junctions between
magnetic materials and semiconductor substrates, and
films of ferromagnetic metals such as Fe or Co grown epitaxially on
semiconductor structures are promising candidates for spin injection.

Zhu and co-authors \cite{Zhu} have
demonstrated efficiencies of 2\% for
injection of spin-polarized electrons from a metal into a semiconductor
for a GaAs/(In,Ga)As light emitting diode (LED) covered with Fe.
Moreover, Hanbicki {\it et al}. \cite{Hanbicki}
have managed to achieve a spin injection efficiency of 30\%.
In the latter case, an Fe film grown on an AlGaAs/GaAs quantum well LED
structure was used.
In both cases it was suggested that the spin injection arises from
tunneling of spin-polarized electrons from the metal into the semiconductor
across the Schottky barrier formed at the interface.
Such a tunneling process is believed to be responsible for
the spin injection since it is not affected by the conductivity
mismatch \cite{Rashba} between the metal and semiconductor that
severely limits the spin-injection efficiency in the diffusive transport
regime.
A remarkable consequence of such a
mechanism is that it is independent of temperature.  In fact, in
Refs. \onlinecite{Zhu} and \onlinecite{Hanbicki},
nearly constant tunneling efficiencies  of 2\% and 30\% were observed for a
range of temperatures from 2 K to 300 K and  from 90 K to 240 K, respectively.
Recently spin injection efficiencies of 13\% have been
reported at 5 K across a Fe/GaAs(110) interface, \cite{Jonker_new} and
6\% across a Fe/Al$_x$Ga$_{1-x}$As/GaAs Schottky contact at 295 K. \cite{Minnesota_new}
At the moment, the room temperature record of 32\% is held by CoFe/MgO
injectors grown on $p$-GaAs(100) substrates. \cite{Parkin}

The electronic structure of the metal/semiconductor
interface plays an important role in spin-dependent transport properties
across such junctions.
For the case of the Fe/GaAs(001) interface, a number of first-principles
studies have been carried out.  Green's function
methods have been used to study the electronic structure, charge transfer,
and spin polarization in Fe/GaAs/Fe(001) tunnel junctions in which the
interface geometry is atomically abrupt and
ideal.\cite{Butler,Dederichs1,Vlaic}
It was noted that the
calculated magnetic properties at the interface are sensitive to the
interface structure, indicating that structural relaxations could be
important.\cite{Dederichs1}  Other studies have focused on the initial stages
of growth of Fe on GaAs and have considered how
structural relaxation and intermixing of metal and semiconductor atoms affect
magnetic properties of thin films of Fe on GaAs. \cite{Erwin,Mirbt,Kim}
Still lacking is an understanding of how details of the
atomic arrangement at the interface affect properties directly relevant to spin
injection, such as Schottky barrier heights  and the nature of
the interface-induced states in the semiconductor gap through which
spins may tunnel.
In this paper, we address this by considering structural models
for the (001) interface between Fe and GaAs that allow for different
degrees of intermixing and relaxation. The
effects of interface structure on potential, charge, and magnetization
profiles, Schottky barrier heights, spin-polarized densities of states,
and interface-induced gap states are investigated.
The results are discussed in connection
with potential spin-injection applications.

The paper is organized in the following way.
Computational details are given in Section II.
In Section III we describe and discuss the structures considered
and the resulting
structural, electronic, and magnetic properties.
Conclusions are presented in Section IV.

\section{Computational Details}

The bulk lattice constants of bcc Fe (2.866 \AA) and zinc-blende GaAs (5.654 \AA)
differ by almost exactly a factor of two. Therefore, an interface consisting
of a (001) Fe slab placed on the (001) surface of GaAs has a lattice mismatch
of 1.36\%.
The close lattice match
helps keep the concentration of defects at such interfaces relatively low.
In this work, interfaces were modeled using
supercells consisting of nine layers of Fe
and nine layers of semiconductor atoms (five As and four Ga, or vice versa, depending
on the semiconductor surface termination.)
This is sufficient to ensure that the adjacent
interfaces do not interact with each other, as confirmed by both total energy
calculations and macroscopic averages of the electrostatic potential and charge.

The calculations were performed with the VASP program, \cite{vasp}
an {\it ab initio} density functional
code that uses the planewave pseudopotential method. The generalized gradient
approximation
was used to treat the exchange-correlation part of the electron-electron
interaction.\cite{GGA1,GGA2} All calculations employed ultrasoft pseudopotentials \cite{Vanderbilt} and planewave basis sets with a kinetic energy cut off of
370 eV.
Monkhorst-Pack meshes\cite{Monkhorst-Pack}
of $8\times 8\times 4$ {\bf k}-points were used to sample the
Brillouin zone, and Gaussian smearing of electronic states
($\sigma = 0.2$ eV) was used to achieve faster convergence of
Brillouin zone sums with respect to the number of {\bf k}-points.

\section{Results}

\subsection{Structure}

The Fe/GaAs interface structures considered in this work are shown in Fig. \ref{fig: ABC}.
\begin{figure}[tbfh]
\includegraphics[width=3.4 in,height=2.0 in]{ABC4.eps}
\caption{Three models for the structure of the $1\times1$ interface
between As-terminated GaAs(001) and Fe(001) surfaces.
Model A is an abrupt interface, model B  has one layer containing
both metal and semiconductor atoms, and model C has two intermixed
layers.
\label{fig: ABC}}
\end{figure}
While the bare GaAs(001) surface reconstructs to form dimers on the surface,
\cite{dimers}
recent calculations  suggest that these dimers become unstable upon
adsorption of Fe.\cite{Erwin}    Therefore,
in this work, we consider 1$\times$1 interfaces only.  We assume
the Fe(001) and GaAs(001) slabs are aligned so that in the first complete
metal layer, sites that would have been occupied by semiconductor atoms in the
absence of the interface are now occupied by metal atoms. An abrupt
interface like this with no intermixing of metal and semiconductor
atoms will be referred to as model A (as in Ref. \onlinecite{Erwin}). In model B, the bcc metal structure is
partially continued into the first semiconductor layer so that metal atoms occupy
sites that are normally empty in the first layer of the semiconductor.
In model C, metal atoms  occupy interstitial sites in the second semiconductor layer as well.
Both As- and Ga-terminated interfaces can
be grown experimentally, and therefore, both are considered here.
We find that for the supercells of the size considered in this work,
model C is never energetically favorable. This agrees with
Ref. \onlinecite{Erwin},
where it was found that model C has lower energy only for coverages of Fe
not exceeding two monolayers. Therefore we focus on models A and B.

The comparison of total energies of models A and B is not physically meaningful
since the interfaces have different numbers of atoms. The formation energies
of these models are, on the other hand, physically comparable and given by
\begin{equation}
E_{form}=E_t-\sum_{i}N_i\mu_i .
\label{eq: form_energy}
\end{equation}
Here, $E_t$ is the total energy of the supercell, $N_i$ is the number of atoms
of the type $i$ in the cell, and $\mu_i$ is the chemical potential of the $i$-th
atom. Thus, all energies from the model B calculations were adjusted by
twice the value of the chemical potential for Fe,
since each supercell contains two equivalent interfaces.
Test calculations of the formation energy
using supercells with one A interface and one B interface
confirm that the supercells are large enough to ensure that the interaction
between interfaces in negligible.

Since electronic and magnetic properties may differ significantly as a
result of small changes in structural parameters, we have relaxed all
the interface models
considered. In our calculations the interfaces were relaxed with respect to two
parameters: the distance between the adjacent Fe and As (or Ga) layers, $d_1$,
and the distance between the first two layers in the GaAs slab, $d_2$
(see Fig. \ref{fig: ABC}). The in-plane lattice constant was fixed at the bulk
GaAs value, $a_0 = 5.654$ \AA.
The results of the relaxation
are presented in Table \ref{tab: relaxation}.
\begin{table}[t]
\caption{Interlayer relaxations, in units of the GaAs lattice constant $a_0$.
Here, $\Delta d_1$ is the difference between the relaxed and ideal ($0.25a_0$)
separation  of adjacent Fe and As (Ga) planes at the interface, and
$\Delta d_2$ is the change in the distance between the first two
planes in the GaAs slab.
\label{tab: relaxation}}
 \begin{ruledtabular}
\begin{tabular}{ccccc}
  & \multicolumn{2}{c}{As-terminated} & \multicolumn{2}{c}{Ga-terminated} \\
\hline
  & $\Delta d_1$ & $\Delta d_2$ & $\Delta d_1$ & $\Delta d_2$ \\
\hline
Model A & 0.0 & 0.025 & 0.022 & 0.017 \\
Model B & 0.017 & 0.068 & 0.018 & 0.058
\end{tabular}
 \end{ruledtabular}
\end{table}
For As-terminated model A, the distance between As and Fe planes remains at
the ideal value of
0.25$a_0$, while the separation between the first plane of As and the
adjacent plane of Ga is stretched
by 10\%. With Ga-termination, both $d_1$ and $d_2$ increase by
similar amounts in model A. In model B, which has the intermixed layer,
the first two planes of the semiconductor slab are
repelled considerably farther apart, regardless of the termination.
It was previously pointed out
that lowering the concentration of atoms in the interface region is
energetically favorable in model B, since the electrons from the extra Fe
atoms  in the intermixed layer
fill antibonding orbitals and weaken the interface bonding.\cite{Erwin}

The results of the formation energy calculations for the ideal and relaxed interfaces are
summarized in Table \ref{tab: energies}.
\begin{table}[b]
\caption{Formation energy differences, in eV per
1$\times$1 interface unit cell.  With As-termination,  the
abrupt interface of model A is favored, while with Ga-termination,
the intermixed interface  of model B is preferred.
\label{tab: energies}}
 \begin{ruledtabular}
\begin{tabular}{ccc}
  & As-terminated & Ga-terminated \\
\hline
  & Ideal - Relaxed & Ideal - Relaxed \\
\hline
Model A & 0.046 & 0.059  \\
Model B & 0.282 & 0.291   \\
\hline
& Model A - Model B & Model A - Model B \\
\hline
Ideal &   -0.400  &  0.318   \\
Relaxed & -0.164  &  0.551
\end{tabular}
 \end{ruledtabular}
\end{table}
For both ideal and relaxed geometries, model A is energetically favored for
As-terminated interfaces, and model B is favored for Ga-terminated
interfaces.
This results from an interplay between optimization of the coordination of the
metal  and semiconductor atoms and the relative strengths of the
metal-cation and metal-anion bonds.  Because of stronger $pd$ hybridization,
the Fe-As bond is more stable than the Fe-Ga bond. \cite{Mirbt}
For model A, the interface Fe site is six-fold
coordinated, with four Fe neighbors in the second metal layer and two
semiconductor neighbors in the first semiconductor layer.  While  putting
Fe atoms in
interstitial sites in the first semiconductor layer fully coordinates
the interface Fe sites in model B, it also significantly weakens the bonding
between the first two semiconductor layers, which become overcoordinated.
At the As-terminated interface, the strong Fe-As bonds compensate for
the undercoordination of the Fe sites, making model A favorable, while
at the Ga-terminated interface, the weak interaction between
Fe and Ga favors full coordination of Fe interface sites, as in model B.

\subsection{Schottky Barriers and Electronic Structure}
Figure \ref{fig: DOS} shows the calculated site-projected
densities of states (DOS) for atoms in different layers in
the relaxed As-terminated model A. The general features are similar
for all the structural models considered. The DOS in the most bulk-like
layers of the supercell closely resembles the DOS of bulk Fe or GaAs.
Near the interface, a peak develops in the DOS at the Fermi level.
The peak is largest in the first Fe layer and decreases into both the
GaAs and Fe slabs. In the first few GaAs layers,
states spread throughout the entire band gap of bulk GaAs, though
the gap is practically recovered in the layer farthest from the interface.
Bardeen \cite{Bardeen} estimated that surface
states with density $\sim 10^{13}$ eV$^{-1}$ cm$^{-2}$
would effectively pin the Fermi level close to the
charge neutrality level in the semiconductor gap.
Our calculations for the relaxed As-terminated model A, for example,
yield values of DOS at the Fermi level
of $\sim 2 \times 10^{15}$ eV$^{-1}$ cm$^{-2}$ in the first Fe layer, and
$\sim 1 \times 10^{14}$ eV$^{-1}$ cm$^{-2}$
in the first two layers of the GaAs slab.
These may be sufficient to pin the Fermi level, which consequently affects
the Schottky barrier height (SBH).   We will return to examine
the nature of these mid-gap states, their spin polarization, and
their role in spin tunneling
in section D.

As mentioned, Schottky barriers may be a necessary mechanism
for overcoming the conductivity mismatch for the injection of spin from a
ferromagnetic metal into a semiconductor.
Schottky barrier heights can be evaluated from first principles using a
macroscopic average method combined with the supercell
approach. \cite{Baldereschi}
Two necessary
conditions are: 1) the supercell contains two equivalent interfaces, which
eliminates any electric fields that might be present due to unbalanced
charges, and 2) the supercell is sufficiently large so the bulk charge
and potential properties are recovered in the most bulk-like layers of the
supercell. In such a way an isolated interface is accurately
modeled using  a supercell.

\begin{figure}[tbf]
\includegraphics[width=3.4 in,height=4.0 in]{dos_by_layer2.eps}
\caption{Site-projected densities of states  for atoms in different
atomic layers of the relaxed GaAs/Fe(001)  supercell
with As-terminated model A interfaces.
The bottom panel represents the semiconductor layer farthest from the interface
(As \#5),  and the top panel represents
the most bulk-like layer of Fe (Fe \#5).  The vertical line at zero energy
indicates the Fermi level. In each panel, the vertical scale
runs from 0 to 1.8 states/eV/atom.
\label{fig: DOS}}
\end{figure}

The calculation of the $p$-type Schottky barrier height, $\phi_p$,
is split into two parts:
\begin{equation}
\phi_p = \Delta E_v + \Delta V.
\label{eq: schottky}
\end{equation}
The band structure term,
\begin{equation}
\Delta E_v = E_F - E_v,
\label{eq: band_term}
\end{equation}
is the difference between the Fermi level $E_F$ in the metal and the valence
band edge in the semiconductor $E_v$, where each is measured with respect to
the average electrostatic potential in the corresponding bulk material.
The band structure term is calculated from separate
bulk calculations for the two constituents of the Schottky contact. This term
implicitly includes all quantum mechanical effects as well as the exchange-correlation
part of the potential.

The other contribution to $\phi_p$ is the potential line-up across the
interface $\Delta V$.  This potential line-up is related to
the dipole moment of the charge profile,\cite{Baldereschi}
depends on the structure of the interface, and therefore cannot be
calculated simply from two bulk calculations.
It is the difference between the macroscopic averages of the electrostatic
potential in two bulk-like regions of the supercell.
As an example, Fig. \ref{fig: pot_As} shows the planar average over the $x-y$ plane
and the macroscopic average of the electrostatic
potential computed for the superlattice with As-terminated relaxed model A
interfaces.
The macroscopic average lacks the bulk-like
oscillations present in the planar average,
and thereby allows one to extract the desired potential
line-up $\Delta V$.
The macroscopic average, however, does not provide reliable information
about potential behavior in the close vicinity of the interface since
the resolution of the method is limited to the lattice period, the
GaAs lattice constant $a_0$ in our case.
There is a notable difference between the planar average and the macroscopic average in the
vicinity of the interface.

\begin{figure}[tbf]
\includegraphics[width=3.0 in,height=2.70 in]{potential1.eps}
\caption{Planar and macroscopic averages of the electrostatic
potential calculated for the relaxed As-terminated  model A supercell.
The potential is plotted as a function of $z$, the position  of
atomic layers along the axis of the supercell.
The potential line-up $\Delta V$ needed for the Schottky barrier
height calculation is given by the difference between the two plateaus
in the macroscopically averaged potential.
\label{fig: pot_As}}
\end{figure}

We have calculated the $p$-type SBH for the ideal and relaxed structures
described in the previous section.
Since it is electrons that are injected from Fe into GaAs in spin injection
experiments, the $n$-type SBH is of more interest.
To obtain the $n$-type SBH from our calculations, we subtract the
calculated $p$-type SBH from the experimental GaAs band gap of 1.52 eV. \cite{Aspnes}
The results are presented in Table \ref{tab: schottky}.
\begin{table}[b]
\caption{ Calculated {\sl n}-type Schottky barrier heights (in eV)
for ideal and relaxed geometries.  Interfaces with intermixing (model B)
have lower barrier heights than abrupt interfaces (model A).
\label{tab: schottky}}
 \begin{ruledtabular}
\begin{tabular}{ccccc}
  & \multicolumn{2}{c}{As-terminated} & \multicolumn{2}{c}{Ga-terminated} \\
\hline
  & Ideal & Relaxed & Ideal & Relaxed \\
\hline
Model A & 0.87 & 0.82 & 1.01 & 1.08 \\
Model B & 0.58 & 0.64 & 0.69 & 0.89
\end{tabular}
 \end{ruledtabular}
\end{table}
The calculated SBH is sensitive to structural changes, and the differences
between the SBH values in Table \ref{tab: schottky} show the magnitude of
changes one can expect for different interface structures.
Intermixing of metal and semiconductor atoms at the interface
decreases the $n$-type Schottky barrier height significantly (by about
0.2-0.3 eV), while the effect of interlayer relaxation is generally weaker.
This level of sensitivity of SBH values to interface structure is
consistent with the observed dependence of measured SBHs
on growth conditions.
For Fe/GaAs interfaces fabricated by metal
evaporation in ultrahigh vacuum, SBHs in the range of 0.72-0.75 eV have
been reported.\cite{experiment}  More recent experiments on As-terminated
atomically clean (001) interfaces grown by molecular beam epitaxy
have yielded barriers
around 0.90-0.92 eV.\cite{experiment_Jonker1,experiment_Jonker2}
In the latter work, the samples had sufficiently low interface defect
concentrations that Fermi-level pinning by antisite defects was suppressed.
\cite{experiment_Jonker1, experiment_Jonker2}
Our calculated results for the energetically favored
geometries, i.e. As-terminated relaxed model A and
Ga-terminated relaxed model B,
are close to the SBH values obtained for these clean samples.
Overall, the present results compare more favorably to experiments than
earlier density-functional calculations of the $p$-type SBH at
ideal Fe/GaAs (110) interfaces.\cite{Mark}

\subsection{Charge Distribution and Magnetic Moments}

To investigate the redistribution of charge that
gives rise to the Schottky barrier, we have computed the charge within
Wigner-Seitz spheres centered on atomic sites.\cite{WS}
We have also compared the planar-averaged charge in the interface region to
the planar-averaged charge in the bulk-like regions and to the planar-averaged
superposition of atomic charges.
The qualitative features of the
charge redistribution deduced from the sphere charges
are consistent with those suggested by the planar-averaged charge.
Figure \ref{fig: WZ} shows the difference
between the charge inside the spheres in the supercell and in the bulk.
\begin{figure}[t]
\includegraphics[width=3.0 in,height=2.50 in]{Ch_WZ.eps}
\caption{Difference between the charge inside the atomic spheres for
the supercell and bulk GaAs and Fe, plotted as a function of distance $z$
along the direction normal to the interface. The upper panels show results for
relaxed As-terminated models A and B, and the lower panels show results for
relaxed Ga-terminated models A and B.
In the intermixed layer in model B,
the higher point represents the charge difference for the As
or Ga atom and the lower point represents that for the Fe atom.
\label{fig: WZ}}
\end{figure}
At the abrupt interface (model A),
there is an evident transfer of charge from the
interface Fe layer into the semiconducting slab, regardless of the
semiconductor termination. In  Ref. \onlinecite{Dederichs1}, it was
found that for unrelaxed abrupt interfaces, the interface Fe loses more
charge to Ga neighbors than to As neighbors.  We find that this
difference is enhanced when the interlayer distances are allowed to relax.
Interface Fe atoms also lose significant charge to the interstitial region
where bond formation takes place.   The redistribution of
charge is limited to regions close to the interface. By the third
semiconductor layer, the charge within the spheres has nearly recovered
to bulk values.

In model B, Fe sites in the first full Fe layer are fully coordinated,
so the local charge around these sites is much closer to the bulk value than
in model A.  The charge redistribution takes place primarily within the
intermixed layer, where the Fe sites are undercoordinated and the
semiconductor sites are overcoordinated.  While the amount of
local charge lost by Fe sites in the intermixed layer is about the same
for both terminations ($\sim0.2e$), with Ga-termination, the Ga sites in the
intermixed layer gain electrons while with As-termination, the As interface
sites lose electrons, indicating a transfer of charge into interstitial
regions in the Fe-As intermixed layer.

\begin{figure}[t]
\includegraphics[width=3.0 in,height=2.50 in]{Mag_all_aver.eps}
\caption{ Local magnetic moments plotted as a function of distance $z$
along the direction normal to the interface.
The upper panels show results for
relaxed As-terminated models A and B, and the lower panels show results for
relaxed Ga-terminated models A and B.
In the intermixed layer in model B,
the higher data point represents the Fe moment
while the lower data point represents the Ga or As moment.
\label{fig: mag}}
\end{figure}
Fig. \ref{fig: mag} shows the local magnetic moments across the Fe/GaAs
interface for all four structurally relaxed models.
The magnetic moments were calculated from the
integrated spin-polarized DOS within the Wigner-Seitz spheres.
There is a small enhancement of the magnetic moment near the Fe
interface in comparison to the bulk-like moment of $\sim$2.3$\mu_B$
in the central Fe layer.  This is similar what was found in
Ref.[\onlinecite{Vlaic}]. Since the Fe moment at the interface is
sensitive to the Fe-As(Ga) bond length and can be quenched by
reducing the bond length by a few percent,\cite{Mirbt} the relaxation of the
interlayer distances near the interface is important.
In model A the enhancement of the Fe moment at the interface ranges from
0.1$\mu_B$ for As termination to 0.3$\mu_B$ for Ga termination.
Model B has a larger enhancement of the magnetic
moment at the Fe sites located in the intermixed layer, with spin moments
$\sim0.4\mu_B$ larger than at the bulk-like sites.
These results, which indicate that Fe is ferromagnetic at the GaAs
interface, are consistent with recent experiments on the Fe/GaAs
(100)-4$\times$6 interface\cite{bulk_like} where bulk-like spin magnetic moments were
observed using x-ray magnetic circular dichroism.
In our calculations, all four structural models also have small induced
opposite magnetic moments in the first semiconductor layer
with the approximate values of  0.04$\mu_B$ and 0.02$\mu_B$ for
As-terminated models A and B, respectively, and
0.08$\mu_B$ and 0.09$\mu_B$ for Ga-terminated models A and B, respectively.

\subsection{Spin-Polarization and Interface States}
\begin{figure}[t]
\includegraphics[width=3.0 in,height=2.5 in]{SP.eps}
\caption{Local majority-spin (circles)
and minority-spin (diamonds) densities of states at the Fermi
level in different atomic layers. The top panels show results for
relaxed As-terminated models A and B, and the bottom panels show results
for relaxed Ga-terminated models A and B.
The vertical scale, in units of states/eV/atom, is kept the
same in all panels to facilitate comparisons.
\label{fig: SP}}
\end{figure}

Figure \ref{fig: SP} shows the local majority (spin-up)
and minority (spin-down) densities of states calculated
at the Fermi energy for the relaxed As- and Ga-terminated models A and B.
Each point on the curves corresponds to an atomic layer.
In all four cases the majority-spin DOS is largest at the center
of the Fe slab and decays monotonically towards and across the interface
into the GaAs slab.
At the same time the minority-spin DOS exhibits a sharp peak in the vicinity
of the interface on the Fe side and decreases into the center of the Fe slab.
In the GaAs slab both majority and minority DOS decay exponentially,
but the dominance of the minority states is preserved throughout the GaAs slab.
Hence, close to the interface on the Fe side,  the spin polarization reverses
sign and peaks because of the large
difference between spin-up and spin-down density of states.
While model B exhibits such a reversal with relatively modest
differences between spin-up and spin-down DOS,
model A shows significantly larger values of spin polarization.

Similar behavior of the spin-dependent DOS at the Fermi level has
been observed both theoretically and experimentally
for the free Fe surface. \cite{surf1,surf2}
A peak in the scanning tunneling spectra of the Fe(001) surface
was attributed to
a minority-spin surface band located about 0.3 eV above the Fermi level
at the $\bar{\Gamma}$ point in the two-dimensional Brillouin zone.
We find analogous behavior at the Fe/GaAs interface, with the
increase in minority spin DOS at the Fermi level
at the interface attibutable to $d$ states
localized on Fe interface sites.  The valence charge
density for one of these interface states at the As-terminated
abrupt interface is shown in Fig. \ref{fig: surf_state}.
This $d_{3z^2-r^2}$-derived  Shockley-like state, located about 0.4 eV
above the Fermi level
at the $\Gamma$ point, produces high densities of states within the
GaAs band gap and decays evanescently into the GaAs slab.
At the intermixed interfaces of model B, analogous states
localized on the Fe sites in the intermixed layer are found near
the Fermi level, but because of the stronger influence of the
reduced symmetry of GaAs compared to Fe, some of these interface states
are more clearly a mixture of $d_{3z^2-r^2}$ and $d_{xy}$ character,
with lobes pointing along the $z$ and $x=\pm y$ directions. (The
$x$ and $y$ directions are along the cubic axes of both the bcc Fe and
zinc-blende GaAs lattices.)

\begin{figure}[t]
\includegraphics[height=3.0 in]{074_gray.eps}
\caption{Valence charge density of a minority-spin interface state at
the $\Gamma$-point in the relaxed As-terminated model A supercell.
The top half of the figure contains Fe layers
and the bottom half contains GaAs layers.
This state lies about 0.4 eV above the Fermi level.
\label{fig: surf_state}}
\end{figure}

These interface states likely play a role in
Fermi-level pinning,
which experimentally manifests as an insensitivity of the SBH
to the metal workfunction.
Our calculations suggest that at the defect-free interface,
the Fermi level is pinned by
Fe minority-spin interface states, supporting the
metal-induced gap states (MIGS) model \cite{MIGs,MIGs2}
rather than the semiconductor surface state model. \cite{Bardeen}
This also agrees with recent experiments on the pressure dependence
of metal/GaAs Schottky barrier heights, \cite{experiment_Jonker2} which
support the MIGS model for atomically clean Fe/GaAs interfaces.
A notable difference between the interface states we find and MIGS suggested
in the original works \cite{MIGs,MIGs2} is that the interface states in our case are
localized at the interface and are not derived from the metal bulk
states.

To quantify the decay of the spin polarized DOS
into the GaAs, we have performed additional large supercell calculations
using the relaxed interface geometries, increasing the number of atomic layers
in the GaAs slab to 17.
A large number of {\bf k}-points was used in the DOS calculations
(24$\times$24$\times$4),
and a Gaussian broadening of states with $\sigma=0.1$ eV was used.
We fit the DOS at the Fermi level in the GaAs slab
to the functional form $e^{-2\kappa z}$, where $\kappa$ is a decay constant,
and $z$ is the distance
from the interface. The decay constants $\kappa_{\uparrow,\downarrow}$
for states with different spin, and corresponding decay lengths
$l_{\uparrow,\downarrow}$, are listed in Table \ref{tab: decay}.
\begin{figure}[t]
\includegraphics[width=3.0 in,height=2.70 in]{decay_gauss0.1.eps}
\caption{The site-projected GaAs DOS at the Fermi level as a function of the
distance from the Fe slab. The majority-spin DOS are plotted with circles  and
the minority-spin DOS are plotted with triangles.
The upper panels correspond to As-terminated models A and B, and the
lower panels correspond to Ga-terminated models A and B.   The
DOS are in units of states/eV/atom.
\label{fig: decay}}
\end{figure}
Semi-logarithmic plots of the majority- and minority-spin DOS at the Fermi
level in the GaAs slab are shown in Fig. \ref{fig: decay},
along with the fitted exponentials (dashed lines).
Each point corresponds to an atomic layer, and data corresponding to the
intermixed layer in model B was omitted since this layer contains both
Fe and semiconductor atoms.
At the Fermi level the minority-spin states continue to dominate the
majority-spin states throughout the GaAs slab. There is a significant proximity
effect in the sense that the {\sl ratio} of the DOS corresponding to the
two spin states does not change significantly.
In other words, the spin polarization of the states at the Fermi
level remains virtually constant into the bulk of GaAs, even
as the magnitude of the DOS decays exponentially.

\begin{table}[h]
\caption{Decay constants $\kappa_{\uparrow,\downarrow}$ (in \AA$^{-1}$) for majority and
minority states and corresponding decay lengths $l_{\uparrow,\downarrow}$ (in \AA).
\label{tab: decay}}
\begin{ruledtabular}
\begin{tabular}{ccccc}
  & \multicolumn{2}{c}{As-terminated} & \multicolumn{2}{c}{Ga-terminated} \\
\hline
  & $\kappa_{\uparrow}$ & $\kappa_{\downarrow}$ & $\kappa_{\uparrow}$ & $\kappa_{\downarrow}$ \\
\hline
Model A & 0.17 & 0.16 & 0.15 & 0.16 \\
Model B & 0.16 & 0.14 & 0.15 & 0.18 \\
\hline
  & $l_{\uparrow}$ & $l_{\downarrow}$ & $l_{\uparrow}$ & $l_{\downarrow}$ \\
\hline
Model A & 3.0 & 3.1 & 3.3 & 3.1 \\
Model B & 3.2 & 3.5 & 3.4 & 3.0
\end{tabular}
 \end{ruledtabular}
\end{table}
The calculated decay constants $\kappa_{\uparrow,\downarrow}$ listed in Table \ref{tab: decay}
show that there is not a significant difference between the decay of
spin-up and spin-down states for a given structure geometry.
Such behavior is expected (assuming that the effective masses of
spin-up and spin-down electrons do not differ significantly) since
states of the same
energy should have the same decay constants unless the potential barriers
for the two particles differ.
The similarities of decay constants show that the Schottky barrier
heights for both spin-up and spin-down electrons are the same, which
is reasonable since the GaAs slab is essentially non-magnetic.
This finding, however, is in
contrast with results of calculations of the electronic
properties of Co/Al$_2$O$_3$/Co magnetic tunnel junctions, \cite{Tsymbal}
where different decay constants for the spin-polarized states at the Fermi
energy in Al$_2$O$_3$, and therefore different potential barrier heights,
were obtained for electrons of opposite spins.
In terms of structure dependence, we find that the interfaces with intermixing
of metal and semiconductor atoms tend to have longer decay lengths than
abrupt interfaces, which is consistent with trends in the calculated
Schottky barrier heights.

\begin{figure}[t]
\includegraphics[width=2.5 in]{symmetry3.eps}
\caption{Schematic flat-band diagram showing
that electrons from bulk states near the Fermi level in Fe
tunnel through decaying gap states in the Schottky barrier
into states near the conduction band minimum in GaAs.
(Note that the width of the barrier region is typically
much larger than the decay length of the gap states.)
In both majority and minority spin channels, there
are bulk-like states in each region that are
compatible by symmetry.  Only in the minority spin channel are
there interface-derived gap states of the right symmetry near
the Fermi level.
\label{fig: symm}}
\end{figure}

While detailed transport calculations, using, for
example, the Landauer or Kubo formalisms,  are needed for
quantitative predictions regarding spin-polarized current,
symmetry considerations allow us to make some qualitative arguments
about the spin-injection process through the interface.
Electrons tunnel from bulk states near the Fermi level in Fe
through evanescently decaying gap states in the Schottky barrier region into
states near the conduction band minimum in bulk GaAs (Fig. \ref{fig: symm}).
The states participating in this transport process must be compatible
by symmetry.
In the approximation that transport across the interface is dominated by
carriers with wave vector perpendicular to the interface, we focus on
states with ${\bf k}_{\parallel} \approx 0$ (i.e., along the $\Delta$
direction in the cubic Brillioun zone of both GaAs and Fe).
The $1\times1$ interface considered here
has $C_{2v}$ symmetry, and so does the lowest conduction band of
GaAs (indexed as ${\Delta}_1^{GaAs}$).  In the Schottky barrier region,
the most important bulk states in the complex band structure
are those with the longest decay length.  In GaAs, these states have
${\Delta}_1^{GaAs}$ symmetry as well.\cite{Mavropoulos}
Therefore, if we consider only bulk-like states, carriers must originate
from states in the bulk Fe bandstructure that are compatible by symmetry with
${\Delta}_1^{GaAs}$ states.  In the majority-spin band structure of Fe,
the $d_{3z^2-r^2}$-derived band, indexed as $\Delta_1^{Fe}$,
crosses the Fermi level  and
satisfies the symmetry requirement.  In the minority-spin band structure,
the $d_{xy}$-derived band, indexed as $\Delta_{2^\prime}^{Fe}$,
crosses the Fermi level and satisfies the symmetry requirement.
Since the $\Delta_1^{Fe}$ band has some $s$ character
as well as $d_{3z^2-r^2}$ character, it is expected that
the coupling of states across the interface will be
stronger in the majority channel.
Thus, considering only bulk-like states, the majority spin
current would be expected to dominate. In fact, transport calculations
based on the Landauer formalism support this conclusion.\cite{Dederichs2}

However, in addition to bulk-like states, interface states
may play a role in the tunneling process.  The interface
states in the vicinity of the Fermi level all have minority spin.
Arising from $d_{3z^2-r^2}$ and $d_{xy}$ orbitals on interface
Fe sites, and resonant with the bulk Fe $\Delta_{2^\prime}^{Fe}$ minority
band that crosses $E_F$, these states provide additional symmetry-compatible
gap states for tunneling  of minority spins through the barrier.    Hence
the presence of these interface states close to the Fermi level  could
reduce the spin polarization of the tunneling current, or even reverse
its sign.  In Table  \ref{tab: interface},
we list the energy of the symmetry-compatible
interface states within 0.5 eV of the Fermi level at the $\Gamma$ point
for different structural models.  These states typically
have dispersions of a few tenths of eV across the Brillouin zone.
Since the proximity of these interface states to the Fermi level
depends on the atomic structure at the interface,
we expect the spin polarization of the injected current
to be sensitive to interface structure as well.
Measurements of the sign of the circular polarization of
electroluminescence from  Fe/GaAs spin LEDs  indicate
injection of minority spins,\cite{Hanbicki}  opposite to what
is predicted from transport calculations for ideal junctions.\cite{Dederichs2}
The present results indicate that details of the interface structure, such as
the degree of intermixing and relaxation, likely
contribute to this discrepancy.

\begin{table}[tbhf]
\caption{Energy of symmetry-compatible minority-spin interface states
within 0.5 eV
of the Fermi level.  Energies are in eV and measured relative to
the Fermi level.
\label{tab: interface}}
 \begin{ruledtabular}
\begin{tabular}{ccccc}
  & \multicolumn{2}{c}{As-terminated} & \multicolumn{2}{c}{Ga-terminated} \\
\hline
  & Ideal & Relaxed & Ideal & Relaxed \\
\hline
Model A & 0.15, 0.16, 0.37 & 0.31, 0.39, 0.39 & N/A & 0.43 \\
Model B & 0.34, 0.41 & 0.16, 0.48  & -0.02 & 0.12, 0.28 \\
\end{tabular}
 \end{ruledtabular}
\end{table}

\section{Conclusions}
We have investigated the electronic and magnetic properties of
Fe/GaAs (001) interfaces using density functional calculations.
Two structural models were compared: one with an abrupt interface and
one with intermixing of metal and semiconductor atoms.
Both As- and Ga-terminations were considered,  and interlayer
separations were relaxed.  Due to differences in Fe-As and Fe-Ga
bonding, the  As-terminated structure favors the abrupt  interface
while the Ga-terminated structure favors intermixing at the interface.
Magnetization profiles show bulk-like magnetic moments at the interfaces.
In all cases, charge is transferred from Fe to GaAs, creating
Schottky barriers that vary in height depending on details of the
interface structure. In general, the SBHs are less sensitive to
interlayer relaxations than to the nature of the interface, with intermixing
of atoms at the interface leading to smaller $n$-type barrier heights.
In all the structural models considered, the minority-spin
Fe interface state induces  states of $\Delta_1^{GaAs}$ symmetry
within the semiconductor gap. These states lead
to a reversal of the sign of the spin polarization of the density of states
near the interface (compared to the Fe bulk), and
this spin polarization of the density of states at the Fermi level
persists well into the semiconductor.  These interface-induced gap
states (which also are likely to play a major part in pinning of the Fermi
level) provide an additional channel
for tunneling of minority spins.  The proximity of these interface
states to the Fermi level, which affects the
magnitude and possibly the sign of the spin polarization of the
tunneling current, varies significantly with interface structure.

\acknowledgments
We would like to acknowledge support from the National Science Foundation,
Grant No. DMR-0210717, and the Office of Naval Research, Grant No.
N00014-02-1-1046.
We also thank the National Partnership for Advanced Computational
Infrastructure for a supercomputing allocation.

redpajama_set_name: RedPajamaArXiv


What's the best edge/ border for my flower bed?
that are rottening and would prefer not to use that again.
What do you have available? Red bricks, flashing, cinder block? Larger rocks?
Your options are pretty limitless. Are you looking for a raised edge or flat border. Assuming raised due to having timbers. This link has multiple border ideas.. The bottles are pretty unique and might be a little iffy for me if mowing and weed-eating next to them. Rusty pipes cut down would look neat. Copper would be way to expensive and someone might take during the night... Bowling balls are interesting and you could add flat marbles for a design on them and would be amazing.. I just made a garden ball with one.
At my house I used bricks as the existing hardscape already had bricks in the design. This just repeated the use for a more cohesive appearance. What is in your hardscape that bears repeating?


A client of ours just complained to us about an issue that is going on for a long time.
Eight out of ten times they do not print at first try.
Client isolation is off, people can reach other places in the network.
Can you please help us here?
Can you please confirm If the AP is set to Static channel?


text:
Home TV Shows The Night Manager Season 2 Updates
The Night Manager Season 2 Updates
It has been over 3 years since season 1 of The Night Manager aired. Although season 1 covered most of John le Carre's books( based on book MI6) there's still room for season 3 we suppose!
It is a noteworthy thing that the season of The Night Manager is being considered.
John le Carré's work was an independent novel and as per Charles Cumming(season 2 writer), the author has never enabled adjustments of his accounts to have a spin-off not founded on one of his books.
All things considered, le Carré has given the undertaking his official gift however the season 2 writers have been vowed to stay silent on its plot.
While plot stays hush-hush, the new composing group has affirmed making a subsequent season that is both dedicated to the world made by le Carré's and matches the main season in quality is vital.
Regardless of whether The Night Manager season 2 will be completely unique or obtain components from other le Carré books is not yet clear yet.
The screenwriter for Night Manager, David Farr will not return as drama-action show Hanna is keeping him busy. Same case with executive Susanne Bier who dreads she wouldn't do her "very best work the second time around," as indicated by Radio Times in an interview.
With respect to which cast individuals could return for the show's subsequent season, many stars from season' 1 like Tom Hiddleston, Hugh Laurie, and Elizabeth Debicki have been intrigued to be there for season 2.
Charles Cumming, the writer has expressed a few characters would return while there would be some others who will not, so it looks likely that in any event a couple of unique cast individuals will highlight in The Night Manager season 2 when it at long last occurs, depending on their busy schedules.
David Farr
John le Carre's books
The Night Manager Season 2
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Easy Season 4: Release Date Revealed!

redpajama_set_name: RedPajamaCommonCrawl


You passed your test, now what?
Before you can actually begin judging you will need to obtain a Safety & Risk Management Certification and a few professional memberships. The Safety & Risk Management Certification you need to obtain is through USA Gymnastic. This is an online course that discusses and reviews safety and risk management topics related to the sport of gymnastics. After you take the course, you must then take and pass (75%) a written multiple choice test. This certification is valid for four years.
Once you pass the Safety & Risk Management Certification, you can then apply for your USA Gymnastics Professional Membership. Applying for your membership includes passing a Background Screening, if you are 18 years or older. Your background screening is valid until July 31, two years from your approval. Once approved, your USA Gymnastics Professional Membership will be granted and will expire on July 31 of each year.
In addition to your USA Gymnastics Professional membership, you will also need to become a Professional member of the National Association of Women's Gymnastics Judges (NAWGJ). Like your USA Gymnastics membership, your NAWGJ membership will expire on July 31 of each year.
If you intend on judging for other organizations like the Amateur Athletic Union (AAU) or High School gymnastics, you will have to become members of these organizations as well.
NAWGJ requires all professional members wear their official uniform. The uniform is a navy blue suit with the official NAWGJ patch on the breast of the jacket, a white blouse, and professional dress shoes (dark navy blue or black). The official uniform can be ordered from Land's End.
First year judges are permitted to wait until their second year of judging to buy the official uniform. Until then, first year judges must wear a navy blue jacket, navy blue slacks and/or skirt, white blouse, and professional dress shoes.
Finally, as part of being an active member of NAWGJ each judge must obtain a specific number of continuing professional education (CPE) hours a year. A year is defined as August 1 – July 31.
"NAWGJ expects a judge to 'want to continue to improve' no matter how long he/she has judged. Judges who think that judging a lot means you don't have to attend clinics or prepare for each meet is not doing the gymnasts justice. Also how long you have been around or 'meets you have had the privilege of judging' doesn't make you better than the next person" states Evelyn Chandler.
Each rating level is required to obtain a specific number of clinic hours a year towards their CPE total. These clinic hours can be obtained from State, Regional or National Congress, Clinics, Courses or Symposiums. The remaining CPE hours can be obtained from coaching (6 hrs.), in-gym with coaches & gymnasts (6 hrs.), volunteering (4 hrs.), or pre-approved video or live practice judging (3 hrs.).
Becoming a women's gymnastics judge is personally rewarding and an honor. Your knowledge of the deductions, rules, and policies is appreciate by all those you work with; fellow judges, coaches, and athletes.
"Having judged for two and a half decades now, I find that there are so many things that are very rewarding with judging. It gives me great pleasure to "give back" to the sport and volunteer my time, knowledge and services, whether that as the Sate Judging Director or as a line judge for a Regional competition", admits Susan.
To obtain more information about becoming a Women's Gymnastics Judge, you can find the contact information for your local State Judging Director (SJD) by clicking here.


text:
Tim's Cheap Phones Make It Americas' Top Pick: Corporate Brazil
Tim Participacoes SA (TIMP3)'s strategy to focus its mobile-phone sales on Brazil's lower-income families is making the stock the industry's top pick in the Americas.
Tim, the Brazilian unit of Italy's largest phone company, has a consensus analyst rating of 4.45, the highest among the biggest 40 telephone companies by revenue in the Americas, according to data compiled by Bloomberg. The figure, which is the average within a range of one to five, with five being the highest, compares with a 4.36 and 4.33 rating for runners-up Telefonica Brasil SA and U.S.-based CenturyLink Inc. (CTL), respectively.
Tim, Brazil's second-largest wireless carrier after Telefonica's mobile unit Vivo, is gaining market share as it boosts sales to consumers who don't spend a lot of time surfing the Internet or watching videos on their phones, according to Richard Dineen, an analyst with HSBC Holdings Plc.
"Tim focused more on supplying customers with voice and cheaper phones that are really more suitable to more limited data usage, like browsing social networks," Dineen, who has the equivalent of a buy rating on the stock, said in a July 2 telephone interview from New York. "They have the right handsets, the right marketing messages. They designed the right voice and data packages."
Telefonos de Mexico SAB, the fixed-line unit of America Movil SAB, has an analyst rating of 1.67, the lowest in the Americas among major companies, according to Bloomberg data. America Movil SAB is delisting Telefonos de Mexico shares.
Tim has advanced 22 percent this year, the best performer on the MSCI Brazil/Telecommunications Services index, which slid 1.1 percent. The company trades at 19.6 times its reported earnings, compared with a 9.2 ratio for Telefonica Brasil.
Rio de Janeiro-based Tim operated 26.9 percent of all mobile phones in Brazil as of May, up from 25.3 percent a year earlier, making it the second-biggest carrier in Brazil, according to telecommunications regulator Anatel. Vivo's market share of 29.6 percent was little changed from 29.5 percent a year earlier. Oi SA (OIBR4)'s share fell to 18.6 percent from 19.4 percent.
Tim's focus on the faster-growing market of mobile phones makes it a more appealing stock than Oi and Telefonica Brasil, which also offer landlines, said Luis Fernando Azevedo, an analyst at Banco Bradesco SA's brokerage.
"Tim is a wireless carrier and has been benefiting tremendously from this fast-growing segment," Azevedo, who rates the stock outperform, said in a telephone interview from Sao Paulo. "While others operate fixed lines, which dilute earnings because the segment has been shrinking in recent years, Tim is almost a pure wireless player."
Expanding GDP
Bradesco's outperform rating, which is the equivalent of buy, means that the stock's return is expected to exceed the benchmark Bovespa index's gain by 10 percent in the next 12 months.
Demand for mobile phones in Brazil, the world's second- largest emerging economy, is increasing even as growth is forecast by analysts in a central bank survey to slow to 2.05 percent this year. Gross domestic product expanded 2.7 percent in 2011, down from 7.5 percent in 2010, while the number of wireless-service subscribers rose 19 percent to 242 million in the period, according to Anatel.
Tim's plan to increase investments in broadband Internet may erode its earnings outlook, said Alex Pardellas, an analyst at CGD Securities in Sao Paulo.
Tim said in a statement in December it plans to invest 7.5 billion reais ($3.7 billion) through 2013 to double its fiber- optic network in Brazil. It aims to provide high-speed Internet to 1 million residential customers in Sao Paulo and Rio de Janeiro states.
Swelling Middle Class
"Tim has engaged in an ambitious plan to offer fixed broadband services," Pardellas, who rates the stock the equivalent of hold, said in a June 29 telephone interview. "I am a bit cautious as to how they plan to roll this out. They are arriving late compared with peers."
Growth in the mobile-phone industry has led to a worsening in quality of the services provided because carriers weren't ready for a sudden increase in demand, Communications Minister Paulo Bernardo said on June 14 in an interview with a pool of radio stations. Bernardo didn't name any particular carrier.
Tim declined to comment, according to a press official who asked not to be identified by name, citing company policy.
Tim will likely benefit further as more consumers buy mobile phones, said Augusto Lange, who helps manage 1.5 billion reais, including Tim shares, at Neo Investimentos in Sao Paulo. Brazil's middle class, defined as households with annual incomes of at least 12,000 reais, swelled by 31 million in the past decade, according to a study from the country's Strategic Affairs Ministry.
"Mobiles are in demand in Brazil," Lange said. "Tim is the company best positioned to capture the growth."
To contact the reporters on this story: Lucia Kassai in Sao Paulo at lkassai@bloomberg.net; Ney Hayashi in Sao Paulo at ncruz4@bloomberg.net
To contact the editors responsible for this story: Jessica Brice at jbrice1@bloomberg.net; David Papadopoulos at papadopoulos@bloomberg.net
More News: Latin America · Emerging Markets
Bloomberg/AC


text:
Doctors +
Patient + Family
Hematology and Oncology Fellowship Program
Why Should You Choose the Tufts Cancer Center?
Community Oncology
Cancer Center in Framingham
Cancer Center in Stoneham
Genitourinary Oncology Program
Patient-centered Care for Genitourinary Cancers
Genitourinary (GU) cancers range from common malignancies like prostate cancer to relatively rare conditions such as testicular cancer. Whatever your concerns, you want the best possible care, so you can get back to your family, work and day-to-day life as soon as possible.
The Genitourinary Oncology Program includes experts from across Tufts Medical Center working together to offer personalized recommendations and leading-edge care for cancers of the male urinary tract and genitals.
Our team provides comprehensive diagnosis and treatment for all GU tumors, such as:
Bladder and other urothelial cancers
Which Treatment Option Is Right for Me?
The experts of the Genitourinary Oncology Program have a great deal of experience caring for patients with GU cancer. Nevertheless, we understand that the most effective treatment programs result from close collaboration among the patient, family and health care team. That's why our doctors take the time to learn about your individual concerns, explain your options and answer your questions before recommending a care plan.
Prostate cancer screening
Pre-treatment evaluations and second opinions
Active surveillance for low-risk tumors
Minimally invasive (robotic/laparoscopic) surgery
Radiation therapy, including state-of-the-art intensity-modulated external beam therapy
Medical therapeutics such as hormone therapy, chemotherapy and tumor vaccines
What If I Need Surgery?
If your GU tumor requires surgery, you understandably may be concerned about the discomfort and potential complications of traditional, or "open," procedures. Fortunately, our surgeons have extensive experience with minimally invasive surgical techniques. We use the latest laparoscopic and robot-assisted technology to minimize your pain, risk and recovery time.
During laparoscopic surgery, also known as keyhole surgery, doctors insert a camera and specialized surgical instruments through small incisions in your abdomen to take a tissue sample (biopsy) or perform more-complicated procedures.
Our advanced, robot-assisted da Vinci Surgical System gives our physicians enhanced visualization, dexterity and precision. As a result, we can perform delicate and complex surgery, such as removing all or part of a kidney, through incisions as small as the tip of your finger.
A Team of Leaders
Effective treatment for complex GU cancers requires a team of experts working in close collaboration. The doctors of the Genitourinary Oncology Program meet weekly to coordinate care for patients. In addition, our nurses, dietitians, social workers and other support staff work with our physicians to integrate services and provide a comprehensive, individualized care plan.
Doctors + Care Team
Request Appointment for Gennaro A. Carpinito, MD, FACS
Gennaro A. Carpinito, MD, FACS
Virtual Appointments Available
Title(s): Urologist-in-Chief, Tufts Medical Center; Chair and Charles M. Whitney Professor, Department of Urology, Tufts University School of Medicine
Department(s): Urology
Appt. Phone: 617-636-6317
Fax #: 617-636-5349
Uro-oncology with special interest in kidney and prostate cancers, da Vinci Robot-assisted minimally invasive urological surgeries, ablative and reconstructive laparoscopic urological surgeries, radical nephrectomy, nephroureterectomy, partial nephrectomy, adrenalectomy, radical prostatectomy, pyeloplasty, minimally invasive endoscopic procedures and SWL (shock wave lithotripsy)
View Full Profile for Gennaro A. Carpinito, MD, FACS
Request Appointment for Thomas A. DiPetrillo, MD
Thomas A. DiPetrillo, MD
Title(s): Radiation Oncologist; Vice Chairman; Assistant Professor, Tufts University School of Medicine
Department(s): Radiation Oncology
Oncologic consultation for general radiotherapy, lung, highdose remote afterloading and intraoperative brachytherapy
View Full Profile for Thomas A. DiPetrillo, MD
Request Appointment for Kathryn Huber, MD, PhD
Kathryn Huber, MD, PhD
Title(s): Radiation Oncologist; Assistant Professor, Tufts University School of Medicine
Radiotherapy for lung cancer, gastrointestinal tract cancers, breast and head and neck cancers, thoracic tumors
View Full Profile for Kathryn Huber, MD, PhD
Request Appointment for Tony Luongo, MD
Tony Luongo, MD
Title(s): Urologist; Assistant Professor, Tufts University School of Medicine
Uro-oncology with special interest in bladder cancer, stone disease, general urology
View Full Profile for Tony Luongo, MD
Request Appointment for Paul Mathew, MD
Paul Mathew, MD
Title(s): Hematologist/Oncologist; Associate Professor, Tufts University School of Medicine
Department(s): Medicine, Hematology/Oncology
Clinical care of genitourinary cancers with a special emphasis on prostate cancer, modeling bone metastases and experimental therapeutics in prostate cancer and other genitourinary malignancies
View Full Profile for Paul Mathew, MD
Stephen P. Naber, MD, PhD
Title(s): Senior Pathologist; Medical Director, Biorepository; Associate Professor, Tufts University School of Medicine
Department(s): Pathology and Laboratory Medicine
General surgical pathology, breast pathology, oncologic pathology
View Full Profile for Stephen P. Naber, MD, PhD
The urologists, oncologists and radiation oncologists in the Genitourinary Oncology Program at Tufts Medical Center are paving the way with research that charts new paths to discovery in a field where there still remains much to learn.
Our physicians not only have clinical expertise in prostate and other cancers, they direct clinical and translational research focused on better understanding how these cancers grow, spread and impact quality of life. For example, Dr. Carpinito's research is focused on finding new therapeutic strategies that improve both survival and quality of life for people with prostate and other urological cancer.
Referring Physician Resources
We appreciate the importance of maintaining close relationships with referring physicians and will communicate with you throughout your patient's course of treatment.
Thomas DiPetrillo, MD discusses when to get screened and how new treatment options are more precise than ever.


These two verses really and truly touches my heart. We, the baptised are God's chosen people. So what is Paul saying in these two verses- He is calling us holy and dearly loved.. Then, what does he say. He is encouraging us to clothe ourselves with compassion, kindness, humility, gentleness and patience. Meaning. that he wants us to be compassionate, kind, humble, gentle and patient. He goes further to say that he wants us to forgive one another. He says, 'Forgive as the Lord forgave you'. Paul continues to tell us that He wants us to put on love which binds all these virtues together in perfect Unity. It is very important for us to be Loving. Paul wants us to clothe ourselves with all these virtues but above all, he wants us to put on LOVE.
I would like to add here that we being God's chosen people, it is important for us to be holy – And to be holy means to be compassionate, kind, gentle, humble, patient and loving. How can we say that we are God's chosen people and be just the opposite to what Paul is calling us to be.
Let us spend some time in meditation and slowly but surely surrender ourselves to God who will change us into people with all these virtues. So it is important for us to surrender ourselves to God and allow Him to work on us. You and I are unfinished products …. For God is still working on us.
God is our Shepherd and we Iike sheep have all gone astray, so God laid all our iniquity upon His Son Jesus Christ so that we the sheep would be saved and redeemed. So, let our prayer be ' Shepherd me O God beyond my wants, beyond my fears from death into life'.


uniIT deals with the University of Graz's information and communication infrastructure and provides a host of special services for students which facilitate and support studying and working at the university.
For example, uniIT provides PC workstations at two training centres on the research campus, administers Webmail, WLAN and learning platforms and offers students certain software at discounted prices.
uniIT is also the first port of call for computer-related questions and problems. Enquiries are dealt with by e-mail or phone and in person at the infopoint in RESOWI and at the infopoint in the WALL building.


text:
Point Pleasant Register on Facebook
Point Pleasant Register on Twitter
Posted on April 30, 2018 by Point Pleasant Register
Point avenges Generals, 15-7
By Scott Jones - sjones@aimmediamidwest.com
POINT PLEASANT, W.Va. — Plenty of runs to spare.
The Point Pleasant baseball team trailed for one inning in a non-conference contest on Saturday against visiting Winfield, as the Big Blacks earned a 15-7 victory in Mason County.
PPHS (10-9) surrendered four runs in the top of the first but closed the deficit to 4-3 in the bottom of the inning, as Carter Smith connected on a two-run home run and Austin Richardson followed with a solo shot.
The Big Blacks knotted the game at 4-all in the second, as Miles Williams provided a solo home run with two outs.
Point Pleasant took control of the game in the third — highlighted by Williams second home run of the contest — as it manufactured seven runs on six hits to take an 11-4 advantage.
Winfield narrowed the margin to 11-6 in the fourth, as a double by Landon Fairchild scored Nicholas Ferguson and Peyton Stover.
PPHS extended its lead to 15-6 in the fifth, as it sent nine hitters to the plate and collected four runs on four hits, one walk and an error.
The Generals countered with one run over the span of the final two of play, as the Big Blacks closed out an eight-run victory.
Williams was the winning pitcher of record for Point Pleasant, as he surrendered seven runs, 10 hits, two walks, while striking out four hitters in six innings of work. Williams also led PPHS at the plate with three hits, including two home runs, with three RBI and four runs scored.
Kyelar Morrow provided one inning of relief for the hosts, allowing no runs, no hits with one strikeout.
On the offensive side, Brody Jeffers had three hits, while Richardson, Carter Smith, Alec Smith, Tucker Mayes and Hunter Blain each finished with two safeties apiece, respectively.
Richardson led PPHS with five runs batted in, as Jeffers provided two RBI. Blain and Carter Smith also had one RBI apiece.
Joel Beattie had one hit to conclude the offensive totals for the Big Blacks.
The win for Point Pleasant earned a season split with Winfield, having lost an 8-6 decision to the Generals on April 2 in Putnam County.
By Scott Jones
sjones@aimmediamidwest.com
Scott Jones can be reached at 740-446-2342, ext 2106.
Point Pleasant WV, 25550
Follow @pp_register
Hi! A visitor to our site felt the following article might be of interest to you: Point avenges Generals, 15-7. Here is a link to that story: http://www.mydailyregister.com/sports/27204/point-avenges-generals-15-7


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What are the best foods to take care of the kidney. The kidneys are a fundamental organ for the correct maintenance of the organism? Its main function is to prevent diseases by eliminating waste through urine. These substances are generated mainly by the intake of food and beverages, so that nutrition plays a basic role in the health of our kidneys.


text:
Virgil Donati's tips for building control, speed and finding your voice on the drums
By Stuart Williams 17 May 2020
Plus! The first look at Virgil's play-though of Pinprick, from his latest album, Ruiniation
(Image credit: Virgil Donati)
The word 'downtime' clearly doesn't enter into Virgil Donati's lexicon regularly. A drummer since the age of three years-old, Virgil's wider emergence came in the early 90s after leaving his native Australia for the US, quickly becoming recognised as one of the driving forces in progressive drumming. Virgil has been prolific in his musical output ever since, as well as constantly striving to evolve and grow as a drummer.
When he hasn't been busy behind the drum kit for his own compositions and projects with some of the world's most revered technical instrumentalists, the Australian powerhouse has delivered hundreds of clinics and masterclasses, as well as educational materials such as his book, Double Bass Drum Freedom and Power Drumming - the classic instructional video that cemented him in the minds of drummers for the past three decades.
His most recent album, Ruination was released late in 2019, and is testament to his un-ending search for development of his craft, combining a career of learning across jazz, fusion, metal and prog to create a diverse, yet highly-listenable cocktail of modern progressive music.
We spoke to Virgil, who was generous enough to offer us his top tips for developing speed, finding your own voice and the importance of improvisation, as well as unveiling a brand new play-through video of Pinprick from Ruination.
Choose your grip
"I guess we've got to go back to the beginning. When I started playing it was back in the 60s. I was barely three years old and the exposure I had to drummers at the time were all playing traditional grip. In those days it was very common. So as a young boy I didn't even question it, I thought that was just the way you had to play drums, I just copied what I saw and what I thought was the way to do it.
Over the years I became obsessed with developing my touch and technique that way, so then even when I realised you could play matched-grip, I just persevered. I'd made a choice, it was feeling good to me so I just stuck with it. I think over the years I developed it to a point where I was able to be quite flexible with it.
So I could use traditional grip in any context, even some pretty hard playing. I played in a lot of hard rock and metal bands when I was much younger and I felt that I'd developed the ability to get what I needed from traditional grip. So it wasn't necessarily that I thought it was the only way, I just became obsessed and decided I wanted to refine it as much as I could.
I want to be honest - just because I do it doesn't mean I think it's the best way to do it. In fact, I'd go as far as saying that if I were to start all over again, I'd play matched grip. But I've put too much time and effort, too many years into developing a touch, feel and sensitivity with that left hand.
The fact that I don't have to rely on flipping the stick over in order to play powerful backbeats means that I don't find the need to have to change. But having said that, it was a long road to get there, and it takes probably a lot more maintenance than my right hand. So in that regard it makes sense to follow the matched grip.
But it was mainly getting out and playing the gigs. Growing up in Australia, it was a very fertile place when it came to the number of gigs, I was playing six or seven nights a week for many years, and that was really what knocked my hands into shape. That and the practice that I'd do during the day. So it was a combination of being put in those situations where you had to play to a high level and with power. I went through about 6-12 months of blisters when I was 15/16 years old, then all of a sudden that wasn't an issue anymore, and I felt like I had the capacity and endurance to play through a gig.
Develop control
I think you have to consider all of the different possibilities when practicing. I think there's a lot of attention paid - and a lot is said - about finger control. But playing with your fingers is important, sometimes I think it's over-emphasised. But I think there needs to be more attention paid to wrist control. Because essentially on a drum kit, rather than just a snare drum or a pad, we're dealing with different surfaces and tensions and different potential for rebound. The rates of speed that we require to move around the kit, I feel that we really need to rely more on wrists than fingers. That was really made apparent to me back in the 90s when I had the good fortune to meet Rob Carson, who at the time was the rudimental champion in the US. Those guys really drill their hands to an unbelievable level. I had some lessons with him and he confirmed my suspicions. A lot of that information I'm still passing on now at my masterclasses and workshops. It's a great way to develop that horsepower that you need for today's styles of music.
The drum core stuff has an advantage because they're just playing the one drum and it's a very, very tight surface. They're getting so much back from the drum, but at the same time they're putting that energy to extreme use in terms of endurance and speed. But a lot of their endurance is coming because of the fact that they've got a wide control between each element: they can cross over between fingers and wrists far more effectively and deeply than say, the average drum set drummer could.
So, because I've worked on that, I can use my wrists from slow to very fast tempos before my fingers are going to need to kick in. Whereas perhaps, if someone hasn't worked so much on their wrist control, they're only going to get to a certain speed before they lose control. The control factor is the biggest issue when it comes to speed and playing from your wrists. It's important to address that because otherwise at some point you're going to sacrifice power for speed if you don't have that control.
"I'd go as far as saying that if I were to start all over again, I'd play matched grip." Virgil Donati (Image credit: Virgil Donati)
The first thing to do is to just isolate the two techniques [wrist strokes and finger rebounds]. Obviously, if you haven't explored much in terms of playing from the wrist then the way to do that is to use what's called a 'locked grip'. In other words, to stop your fingers from influencing the stroke, you just lightly hold the stick against the palm of your hand with your fingers. Don't allow your fingers to come away from the stick, and that way you'll be using your wrist for every stroke.
A great way to practice that is to start one-handed. Start with your left or right hand and do accent patterns. The one I like to do is a triplet exercise with a strong accent on the downbeat, starting with the stick in a high position. Then the two un-accented notes are played from a very low position, still from the wrist even though they're played a lot lower position. The other concept behind this is that you're developing control from the wrists, you're not just bashing with every note. You have this contrast, and that starts to also build that control.
It's the only time I'll really recommend doing an exercise from slow to fast. Start slowly, concentrating and scanning everything to make sure you're doing everything with control. Then you gradually speed up to the point of challenging yourself, where you're out of your comfort zone. The one thing that I always like to recommend is to not ignore the fundamentals. The basics of hand technique and rudiments. Rudiments are basic hand-to-hand patterns that each you basic independence, so don't approach them too flippantly. They require some work. If you spend time working on sticking patterns, and do it intelligently - look at your hand and observe the movement and arc of the stick - are your hands relaxed? Is the fulcrum in the right place? You keep working on that and over the years you develop a sweet spot. You can talk about it, but it's hard to put your finger on what the elements are apart from nuanced details.
For a while I did basic exercises where you go from one finger to the next and try and get control over that. But really, in your general playing, it's all about a feel - it becomes a combination of these techniques, including arm strokes where you're using a part of your arm pivoting as well for bigger accents. Ultimately it's a combination of those two elements, but by isolating and strengthening both your fingers and your wrists, you improve your overall technique. For your fingers, I'd probably do combinations of exercises between your hands. Maybe three right, three left, six right. Then three left, three right, six left. Come up with variations of those types of patterns to draw them out longer, just to help get the endurance with your fingers.
Rudiments aren't just for your hands
"I guess the rudiments on the feet stemmed from my approach, my concept of playing double bass drums. It came from more of a rhythmic approach than a rigid metal single stroke approach. What I was interested in was to create rhythms and play ideas with double bass drums and grooves.
So anything I practiced with double bass drums, I'd do it with my hands playing some sort of groove or time along with it. I never really isolated my feet. I wanted to play rhythms, not just see how far I could push a single stroke roll.
To that end I used to experiment with different combinations of singles: three-stroke singles, fives, sevens and combining them in different patterns. Then I did the same with inserting various 32nd-notes in-between 16th-note combinations, and that creates some really nice patterns.
I experimented a little with flams as well, and then ultimately got into double strokes. I thought 'That could be and interesting way to play long, continuous rolls', in lieu of single strokes. Single strokes tend to have that really rigid sound about them I thought that with double strokes you'd probably get this really nice, rolling effect. Because you're going to get variations between each stroke. There's no way you're going to get every note 100% even in terms of velocity. So that in itself creates a nice alternative feel to playing single strokes.
So I explored that, and I wasn't entirely sure of the potential of where you could take it. This was back in about 1991 I think. I just experimented with it for about a year until I got it to a point where I thought, 'Ok, this really works, you can really build some speed with this'. Around that time was when I did my second instructional video - Power Drumming - that was the first time I played those double strokes publicly. So now that's remained part of my arsenal."
"I haven't explored all options with bass drums, I basically stick to the fundamentals which is just pivoting at the ankles. I never really explored the heel/toe thing. Everything just comes from a combination of my leg and pivoting at the ankle. So you can compare that to the wrist and finger techniques, its kind of analogous to that.
The only thing that does occur is when my doubles get to a certain speed, there's a kind of sliding. I think it's kind of a natural mechanism that kicks in, your feet just start to slide forward on that second beat. That may look a bit like the heel/toe thing, but it's not. I think it may have something to do with the body's mechanism to keep energy circulating, to stop tension from building. It's not a practiced movement, it just unconsciously kicks in.
If I find some time one day, maybe I'll give the heel/toe technique a try, but I'm not sure I have the patience at this point in my career to sit down and learn a totally different technique! I think I've been well-served this far, the way I've done it."
Develop your weaker foot
"I think perhaps just playing with the left foot. Play exercises - if anyone gets the chance - I wrote a book on bass drum technique called Double Bass Drum Freedom. It's out there and it's basically got everything I've ever worked on, but the first chapter addresses the issue of getting your weaker foot to move when it hasn't done nearly as much as your other foot.
The first thing is getting some feel and movement into that foot. But another thing to try is to do everything you do with your main foot with your other foot. If you're working on grooves, swap feet while you're practicing. This is what practice is for - to work on problem areas and weak points - so that's what I would recommend."
Speed comes slowly
"There's got to be a balance. You've got to deal with the fundamentals. It depends on where you are in the timeline of your development: if you've just taken up drums in the last six months, I'm not going to tell you to push yourself to any extreme. But in a nutshell, just work out the fundamentals.
Work on the hands, do it with control and with patience, then at a certain point you do have to start pushing your limits. Now, that's dangerous because in the hands of someone who doesn't quite have a grasp on their technique, or the control and awareness to play things as they should in terms of sounding even, they perhaps need some guidance from a teacher.
But at some point, you do need to start pushing yourself beyond your comfort zone because it's the only way you get to see what's on the other side. But do it with understanding. Go to a point where it's really challenging, it may even hurt a little bit, and then just pull back. Now you've got your point for where you need to get to. You can practice for six months or a year and that will become part of your comfort zone, then you can go to the next level.
I guess you can draw analogies to athletes, or a workout in a gym. How do you build muscle? You push yourself a little. You go to the point where it might challenge you, but you get stronger for it. It's very similar."
Trust your instincts
"I spoke about not bypassing the fundamentals. That gives you a strong foundation, but from there you need to be prepared to work hard and develop a unique voice. In order to achieve that, you need to have an amount of trust in your own vision. Don't allow yourself to be dragged around and become disillusioned by other people's opinIons. We can all get sidetracked by that - and they are only opinions.
At some point, you've got to have faith in yourself, be true to your convictions and just forge that path for yourself. And always remember that nothing worthwhile comes without unrelenting effort. You've just got to work for it, and that's my ultimate advice for younger drummers.
It takes years for the creative process to evolve, so you've got to have patience. You're going to be confronted with your mechanical challenges, but also the musical and rhythmical challenges. And then you've got to learn how to interact with other musicians. So it's a drawn-out process. For me right now, it's about finding the balance between feelings and ideas. Ideas are great, they're pre-conceived. But the ability to be able to sit down at a drum kit and be able to unite those qualities of ideas and feeling, to me it's the apex. Where you can just sit and improvise and create something beautiful."https://www.youtube.com/watch?v=x9XdPjxReDc
Feel can be learned
"That kind of freedom comes from the work that you put into your rhythmic expression on the drums: your ability to express yourself, exploring rhythmic possibilities in your practice, becoming comfortable with each unit of every beat, understanding where you are within the pulse, counting.
Becoming deeply intimate with rhythm so that it becomes part of your feel. It's your inventory of options. Your brain is storing all of these possibilities and this ability to hear things and understand them, and being able to call upon them in the moment - that's what improvisation is.
So when we talk about feel, it sometimes seems like people might have this idea that feel is just this thing that exists in us that we draw upon - just a natural thing that you can't tamper with.
But no, feel is something you have to develop too. You can feel what comes naturally to you, only as far as your limitations are. So you need to enhance that, so that you can 'feel' more things. That sounds a bit deep, but it's true! The important thing is to keep striving, that's the beauty of art."
Virgil Donati's latest album, Ruination, is out now.


Acquisition of property for industry within City of Henderson and its Extraterritorial Jurisdiction (ETJ).
Support and Expand Job Training opportunities such as Welding School/Plumbing School/Electrical School or other vocations.
Aggressively pursue every industrial lead.
Provide Leadership – The community expects us to provide leadership, and we will.
Maintain a strong community presence by participating in the Chamber or Commerce, City of Henderson, Main Street and other community organizations.
Visitation schedule in the industrial community – Maintain a schedule to personally visit industrial and other businesses in the community.
Work to develop a stronger higher education presence in Henderson, most likely through Kilgore College and Henderson ISD, but perhaps also through UT Tyler and/or Stephen F Austin University.
Work with the City, Chamber and development community to engage a developer to develop new residential homes within Henderson and an apartment complex.
Work with the City, Rusk County Airport and TXDOT Aviation to extend the runway at Rusk County Airport to 5,000 feet. Evaluate benefits of extending additional water and sewer infrastructure to Rusk County Airport area.


text:
Q: wrong # args: should be "_o3 self class proc file optx opty" When I ran the tcl code, the following error appeared:
wrong # args: should be "o3 self class proc file optx opty"
(Simulator namtrace-all-wireless line 1)
invoked from within
"$ns namtrace-all-wireless $namtracefd"
(file "test1.tcl" line 26)
How should I modify my tcl code to make the program run correctly.
This is code script in tcl file:
set opt(ifqlen) 50
set opt(nn) 6
set opt(rp) AODV
set opt(chan) Channel/WirelessChannel
set opt(prop) Propagation/TwoRayGround
set opt(netif) Phy/WirelessPhy
set opt(mac) Mac/S-MAC
#set opt(mac) Mac/LMAC
set opt(ifq) Queue/DropTail/PriQueue
set opt(x) 2000
set opt(y) 500
set opt(ll) LL
set opt(stop) 1000
set opt(energymodel) EnergyModel
set opt(initialenergy) 1000
set opt(receivepower) 0.3682
set opt(transmitpower) 0.3442
set opt(idlepower) 0.3442
set opt(sleeppower) 5.0e-5
set opt(transitionpower) 0.05
set opt(transitiontime) 0.0005
set ns_ [new Simulator]
set tracefd [open 1Sthreenodes.tr w]
$ns_ trace-all $tracefd
set namtracefd [open 1Sthreenodes.nam w]
$ns_ namtrace-all-wireless $namtracefd
set topo [new Topography]
$topo load_flatgrid $opt(x) $opt(y)
set channel [new Channel/WirelessChannel]
$ns_ node-config -adhocRouting $opt(rp) \
                                -llType $opt(ll) \
                                -macType $opt(mac) \
                                -ifqType $opt(ifq) \
                                -ifqLen $opt(ifqlen)
                                -antType $opt(ant) \
                                -propType $opt(prop) \
                                -phyTyenter code herepe $opt(netif) \
                                -channel $channel \
                                -topoInstance $topo \
                                -energyModel $opt(energymodel)\
                                -txPower $opt(transmitpower)\
                                -rxPower $opt(receivepower)\
                                -idlePower $opt(idlepower)\
                                -sleepPower $opt(sleeppower)\
                                -transitionPower $opt(transitionpower)\
                                -transitionTime $opt(transitiontime)\
                                -initialEnergy $opt(initialenergy)\
                                -agentTrace ON \
                                -routerTrace ON \
                                -macTrace ON \
                                -movementTrace OFF
for {set i 0} {$i < $opt(nn)} {incr i} {
          set node_($i) [$ns_ node]
          $node_($i) random-motion 0;
}
for {set i 0} {$i < $opt(nn)} {
     $node_($i) set X_ [expr $i*200]
     $node_($i) set Y_ [expr $opt(y)/2]
     $node_($i) set Z_ 0.0
}
set udp_(0) [new Agent/UDP]
$ns_ attach-agent $node_(0) $udp_(0)
set null_(0) [new Agent/Null]
$ns_ attach-agent $node_(5) $null_(0)
$ns_ connect $udp_(0) $null_(0)
set cbr_(0) [new Application/Traffic/CBR]
$cbr_(0) set packetSize_ 512
$cbr_(0) set interval_ 1.0
$cbr_(0) set random_ 1
$cbr_(0) set maxpkts_ 1000
$cbr_(0) attach-agent $udp_(0)
$ns_ at 10.0 "$cbr_(0) start"
for {set i 0} {$i < $opt(nn)} {incr i} {
    $ns_ at $opt(stop).0 "$node_($i) reset";
}
$ns_ at $opt(stop).0 "stop"
$ns_ at $opt(stop).01 "puts \"NS EXITING...\"; $ns_ halt"
proc stop {} {
     global ns_ tracefd
     $ns_ flush-trace
     close $tracefd
}
puts "starting simulation..."
$ns_ run

A:
wrong # args: should be ... optx opty

One of several typos: The original line 26 should be $ns_ namtrace-all-wireless $namtracefd $opt(x) $opt(y)
Snippet, examples editing
-set opt(mac) Mac/S-MAC
+set opt(mac) Mac/SMAC          ;# edit to the ns2 default SMAC

+set opt(ant)    Antenna/OmniAntenna     ;# antenna model missing

+set opt(x) 2000      ;# area added
+set opt(y) 500

+# create God
+create-god [expr $opt(nn)]     ;# missing god

 $ns_ node-config -adhocRouting $opt(rp) \
                                 -llType $opt(ll) \
                                 -macType $opt(mac) \
                                 -ifqType $opt(ifq) \
-                                -ifqLen $opt(ifqlen)     (missing \)
+                                -ifqLen $opt(ifqlen) \
                                 -antType $opt(ant) \
                                 -propType $opt(prop) \
-                                -phyTyenter code herepe $opt(netif) \ (!!)
-                                -channel $channel \      (surplus ?)
+                                -phyType $opt(netif) \
+                                -channelType $opt(chan) \   (missing line)

+# Define initial node position in nam    (missing definition)
+for {set i 0} {$i < $opt(nn)} {incr i} {
+$ns_ initial_node_pos $node_($i) 40

-$ns_ at 10.0 "$cbr_(0) start"
+$ns_ at 10.0 "$cbr_(0) start"          ;# forbidden character " edited

-$ns_ at $opt(stop).0 "stop"
+$ns_ at $opt(stop).0 "stop"            ;# forbidden character " edited

An edited file example is here https://drive.google.com/file/d/1OP49HAAhxHumWacE_qsSq1gFBZkLi0ak/view?usp=sharing
NAM complains "node 6 not defined". Suggest: Edit nn to 7 nodes.
Second example = 2-zhang-test1.tcl, with node positions https://drive.google.com/drive/folders/1aTFX1vJs2k0IchPCqq6cpj_UKeTHch31?usp=sharing : Special SMAC example Energy_wireless-4x4-grid+4__flows.tcl is included.

SMAC-examples-4.tar.gz
https://drive.google.com/file/d/1nO4aZWwL7wkmAlVOGGZI40-kjl4bqeb0/view?usp=sharing
ns2 Energy model examples https://drive.google.com/file/d/1g8WnlHHHnNXBLc0rwJY4i1z9uieKtl9s/view?usp=sharing
All ~2500 ex https://drive.google.com/drive/folders/0B7S255p3kFXNSmRYb2lGcDRUdWs?usp=sharing

redpajama_set_name: RedPajamaStackExchange


MLS# 14043707 - Built by Altura Homes - CONST. COMPLETED Apr 15 ~ Beautiful 422 with granite counter tops in kitchen, tile in all wet areas, stainless appliances (minus fridge), full sod, sprinkler and fence included.. Also has a garden tub with separate shower. A must see!


A school in Worthing claims its children are in danger after they've been left without a traffic crossing guard.
Two girls and a boy - all thirteen - have been arrested on suspicion of arson in connection with a fire at a former school in Sussex.
Firefighters were called to the site of the old Grays School in Western Road, Newhaven, earlier today.
Despite being trashed by vandals and forced to close for more than a week, the St Francis Special School in Fareham re-opened today thanks to the work of staff and volunteers.
Thousands of pounds of damage was caused during the break-in, with windows smashed, roof tiles ripped off, and graffiti on the walls.
It was the fourth time the school, described as a lifeline for many families, has been vandalised in months.
The headteacher says those responsible should return to the school to see the children who were so badly affected. Kerry Swain reports.
The Isle of Wight Council has started the formal process of appeal to the High Court, for clarification on a matter of law over unauthorised school absences and the fines imposed on parents.
The appeal comes after an Isle of Wight Magistrates' Court decided that a father who had taken his child on holiday during term time had 'no case to answer'. The man had failed to pay a fine imposed on him for taking his child out of school - it was deemed an 'unauthorised absence'.
"The recent media attention given to this case shows that there is interest, concern and, above all, uncertainty as to what constitutes 'regular attendance' for the purposes of the legislation in question. This is not a question that can be resolved by any local authority.
"The decision made by the magistrates was made on a point of law. The Isle of Wight Council has received clear advice that the magistrates may have failed to interpret and apply the law correctly in making their decision. Where the law created by Parliament is uncertain, the Appeal Courts have the ability to lay down a binding ruling as to the correct interpretation of the law.
Jon Platt from the Isle of Wight won his case earlier this month. He had refused to pay a £120 fine for taking his 6-year-old daughter on holiday in term time.
A father from Kent says his wife killed herself after the strain of looking after their autistic daughter became too much when they didn't get the help they wanted from social services.
Daniel Barnett's wife Carol had a history of depression and alcohol problems but, he says, the authorities should have done more for their daughter.
He wants Kent County Council to send her to a specialist residential school to help her develop - the council says she's better off at home. David Johns has the story.
Many schools have business classes nowadays but how about their own vineyard?
Well, pupils at Buckswood School outside Hastings are learning the science, production and art of wine making - and they've got their own vintage to prove it.
Andy Dickenson reports and speaks to head teacher Mark Redsell, pupils Tom Milne and Alexandria Roberts, and local winemaker Alex Carr-Taylor.
Pupils have been using a special on-site machine to recycle leftovers from their school dinners. It's called a Ridan Composter, and is part of a pilot scheme backed by Oxfordshire Green Schools. The resulting muck is then used to grow vegetables in the school garden. Cary Johnston reports.
He's just 14-years-old but Gavin Kapuscinkski has started a campaign to keep his secondary school open. Yesterday, Kent County Council announced plans to shut the Chaucer School in Canterbury. Tom Savvides taks to Gavin, parent Sue Tomkinson and councillor Robert Gough.
Six hundred students will have to move schools in Canterbury after drastic action by the council. The Chaucer school in the city, which was in special measures, has been forced to close after failing to turn itself around. This report by Tom Savvides includes a promotional school video.


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It's a good idea to choose an activity that will cause long term success. You've got to love exactly what you do, but if you cannot discover sufficient work to obtain you through the winter season, exactly what's the point? So do a little research study, read the documents and ask individuals on the jobsite exactly what they earn and where they see the trade in five years. You might be amazed.
Trade unions have a long history of teaching employees through using apprenticeship training. This important training consists of on the job training and in class/in lab research study. Here's the very best part; they typically pay for it too. "Earn while you discover", is their motto. Sometimes you can earn as much as 60 college credits that are transferable when you participate in a certified apprentice training program. Keep in mind: Steer clear of the non-union counterparts; these phony apprenticeship programs are often little bit more than scams and are the shiner of the construction industry.
If you think a high school diploma doesn't have much to do with success in the construction market, you're incorrect. With a diploma you can be accepted into a range of certified apprenticeship programs that will invest 10s of countless dollars in your training. And research studies show that you will earn around $5000.00 more each year if you have a diploma than if you don't. That's a lot of money throughout a profession. Classes are frequently available in the evenings for working specialists. Sign up today to earn yours.
Tardiness is a sure fire way to obtain laid off in construction. Possibly you operated in an office environment and it didn't seem like it was that huge a deal, but in construction, it's a big deal. Safety meetings are usually carried out at the start of a shift, and by not existing, you're risking the life of every worker on the task. Not to mention it's simply bad business. Construction workers are paid by the hour worked. Do your career, your coworkers and your foreman a favor, show up on time every day. Even a worker with sub par abilities who appears on time will outlast a worker with good abilities who has a routine of appearing late.
By its very nature construction suggests change; different areas, various conditions and different trades all working for a common cause, conclusion of the project. This means that although each trade has a set schedule, that schedule is likely to change when conditions on the task require it. Therefore you have to be flexible too. You might be asked to work overtime to finish a job, perhaps there's wire to be drawn in and you're only midway done, or the drywall has to be completed this evening because the painters are coming in the early morning. Whatever the situation is, it's a great idea to be versatile. Think about working the overtime. Not everyone can, but individuals who do are a lot more likely to remain used through completion of a task.
It's a truth; individuals will always take pleasure in working with other individuals that have an excellent attitude. Ask yourself, "Would you rather work with a person who enjoys his work or someone who is constantly grumbling and unpleasant?" Exactly. You're going to be investing a great deal of time with your coworkers. Some of them you are going to like and a few of them you might not. Have an excellent mindset, enjoy yourself and leave all your problems in your home.
By following these six guidelines for success in the construction market, you'll have gainful work and have a lot of enjoyable at the same time. With a little preparation, you can reach your goals, avoid that next layoff and create the life you want.
UK's Premier construction recruitment agency offering temporary trades, labour, plant operators based in Stretford Court, England, HR6 9. construction recruitment agency specializing in residential & commercial contracts.


VA Form 2793 is a United States Department of Veterans Affairs form also known as the "Shop Data Sheet (artificial Limbs)".
The latest fillable PDF version of the VA 2793 was issued on March 1, 2002 and can be downloaded down below or found on the Veterans Affairs Forms website.
form is solicited under authority of Title 38, "Veterans Benefits", and will be used to assist us in evaluating your facility. It will not be used for any other purpose.
which you may be entitled.
23. IS SHOP EQUIPPED WITH PARALLEL BARS FOR WALKING TRAINING?
25. IS SHOP EQUIPPED WITH RAMPS?