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Georgia Plays Clemson in Four Weeks: Why Tajh Boyd will Struggle against Georgia's Defense
Posted by dudeyoucrazy
Clemson quarterback Tajh Boyd has played in 34 career games. In 28 of those games he has posted the following combined statistical passing line:
496 completions in 792 attempts for 6,774 yards, 64 TDs and 24 INTs.
Got all that? Those numbers yield a total efficiency number of 155.08.
In his six other games he has compiled this statistical line:
122 completions in 197 attempts for 1,279 yards, 9 TDs and 4 INTs.
That generates a passer efficiency number of 127.48.
Via.
Is that spread significant? Yes. The first efficiency number would have ranked 16th in the country last season. The second number would have ranked 73rd?
You know what my favorite part of this random data comparison is? The six games in which Boyd was considerably less impressive are Boyd's six career games against SEC defenses.
Georgia's defense is still an SEC defense.
That's all I got/
If you've missed out on any portion of the Clemson Countdown of Insults, the archive is as follows:
The Founding of Clemson
The PeeAndre Hopkins Incident
Clemson's Unknown Offense
Clemson vs. the SEC
Clemson is the new Georgia Tech
Dabo Swinney is crazy
Remembering the last game
Clemson's Really Good Defense
Clemson's Rock
Georgia Fans > Clemson Fans
Clemsoning is a thing courtesy of Urban Dictionary
Sammy Potkins Talks Trash
The Dumbest Tradition in College Football
Georgia Beats Clemson in Academics
Richt is Better than Dabo
Posted in Blog, Georgia Bulldogs, SEC
Tags: Clemson, SEC, UGA
Georgia plays Clemson in 9 weeks: Here's What Urban Dictionary Has to Say About It
I found this on UrbanDictionary.com. And, please note that it was published on January 10, 2012 by someone who is not me.
Posted in ACC, Blog, SEC
Tags: ACC, Clemson, SEC, UGA
Georgia Fans–Let's Talk About the "Elephant" In The Room
Posted by Jennifer
My Fellow Georgia fans, we need to talk.
A new football season begins in a mere (67) days. Most of the us as Georgia fans would agree that there's a lot to look forward to, including an offense that has the potential to be one of the most potent in years, a (mostly) promising new defense, and a renewed belief in the power of the Red and Black.
But with so much ahead of us, I'm afraid there might be a bit of a distraction that is making us look back, perhaps a more than we should. A bit of Bulldog Baggage that might need to be dispatched with.
Not that clinging to past glories as well as goof-ups a little too tightly has ever been a problem for us, right, my fellow 'Dawgs?
For years, our conference rivals and regional foes have mocked us for fixating on a certain running back from Wrightsville and a miracle play at the Cocktail Party that secured our National Title bid. That happened over 30 years ago. Then there's those of us who endured Georgia Football in the the '90s. These were the days of "Play Away Ray" Goff and the painfully unfulfilled potential of the Donnan years. Sometimes it seems that this lost generation of Georgia fans still carries that weight on their psyche, often deep down still unsure that we could ever be among the College Football elite. Even now. (Ask people who were in Athens in the '90s and they'll likely tell you that back then dreaming big was a 8-4 season and a Carquest Bowl appearance.)
One way or the other, I think it's fair to say that we've frequently been guilty of a collective preoccupation with the past, whether remembering it too fondly or too bitterly.
But now, there's one thing hanging over our collective heads, although this time it is a single night not so long ago. It had moments of ecstasy only to end in agony. And I think it's time address it once and for all and move on. It's that proverbial Elephant in the Room. Or perhaps the "Elephant" that we faced on the field on that first day of December last year.
Of course I'm referring to the 2012 SEC Title Game…the true National Championship Game.
I don't need to rehash the details too much. But everyone knows what that game meant to us. Everyone agrees that it was an important moment not only considering the stakes (a shot at a national title, which would've been poetic considering it would've been against Notre Dame, just like the last one) but also that it made us believe–finally–that we deserved to be there.
It was also a loss that cut deeper than anything I've ever seen. And the effects are still lingering. There are still stories out there about it despite that it was over 6 months ago. Check out any YouTube video of the game and you'll likely find fresh comments still rolling in. From fans on all sides, too.
The fascination as well as the devastation that still remains is understandable, for both players and fans. I completely understand when Mike Bobo recently told the players that they were probably "never gonna get over it" and had to just "learn to live with it". I get why Aaron Murray eventually stopped watching the last play video while Chris Conley has watched it repeatedly in an effort to process it all.
I have to say I get it on a personal level….I mean, it's not like I haven't found myself watching the last 1 minute and 51 seconds of that game over and over while listening to Steely Dan's classic song "Deacon Blues" refer to the Crimson Tide as the "winners in the world"… (with the protagonist of the song professing to want a name when he loses…)
OK, maybe that's just me. In fact I'm sure it is. (You don't need to tell me how weird and nerdy that reference is, not to mention it making me sound very old–I already know!)
But there's a difference between the players, coaches, and fans here. The players and coaches lived this game in a way we never will. They have the right to deal with things in their own way. But as for us fans, well….I think we have an obligation to put it all in proper perspective before the 2013 season starts.
In other words, Bulldog Nation, it's time for some Tough Love.
This I will consider my final word on it all:
–We played our hearts out. We matched what was thrown at us. They just got one more lucky break than we did. Plain and simple. It could've easily gone the other way. Even the usually overconfident Nick Saban probably needed a drink after this one, saying that the last quarter gave him "a heart attack".
–There was complete respect on both sides of the football, which unless it's Bowl Season is often hard to come by in the SEC. Even now, whenever I meet a 'Bama fan I get nothing but warm regard, and always give it right back. That this still happens as though the game was last Saturday shows that this was a truly one for the ages. We should remember to feel privileged to have been a part of it.
— The "Spike the Ball" talk has to stop. Right now. And for good. So there might have been a way stop the clock in so doing, and we might've had another shot at glory. But just because we might have stopped the clock does not guarantee that the next play might not have been tipped and ruined, too. It doesn't guarantee that a turnover might not have happened. And as likely as it would've been, it does NOT guarantee that we would've gone to the title and steamrolled Notre Dame. OK, in all honesty we probably would've, but that's not the point. The point is not to assume that altering one call would've meant everything else would've stayed the same. Change one thing and who knows what kind of butterfly effect it might have precipitated. The truth is we'll never know what might have happened. Ever.
–And that is OK. It has to be.
–We almost got there. This would've been inconceivable three years ago. Or five years ago. Lord knows it would've been a pipe dream 15 years ago! The best thing that came of this is that we can now believe that we are capable of great things, that we deserve to be on the National Stage, and that we will continue to be a contender. Even when it we started showing up at SEC title games on a regular basis in the last few years, a genuine shot at a national title seemed as likely my winning The Voice. Now I believe we can make it to the ultimate College Football contest (though I don't hold out hope for my making team Blake or team Adam any time soon…) and believing is an essential part of the journey.
So Georgia fans, I feel your pain. And your joy. Seriously, I do. But it's all in the way that you interpret it. I see this game as the ultimate motivation, a harbinger of good things to come, a prelude for what might well be a magical season. But all the same in the past. This is one way to look at it.
Or we could just fuss and fume about firing coaches, Spiking Balls, and bemoaning how it will be another 32 years before we have prayer for another National Title. Doesn't sound like much fun to me.
The choice is yours, my fellow fans….make it the right one!
Next week…..Who are the most loyal fans in the SEC? The answer may surprise you!
–Jennifer Rohner, Chief Cultural Correspondent
@jennifer_rohner
Tags: Alabama, SEC, UGA
In-depth look at the 2013 Gamecock Defense: More Experienced than Georgia?
Posted by Johnathan Barnes
Recently our fearless leader here at DudeYouCrazy spoke on Jadeveon Clowney and the hype surrounding him. He also said he figured I would be speaking soon about the Gamecock defense. What do you know? He was right about something Gamecock related!
Now, we all know how hard South Carolina was hit by attrition on the defensive side of the ball. If you have been under a rock since January, we lost just about everyone on the defensive side of the ball. Hard hitter DJ Swearinger is gone, and his presence will be more than missed. Long time starter at Defensive End, Devin Taylor is also gone to the NFL. Our two-deep at our Linebacker and Spur spots are depleted. The team that takes the field on August 29th will feature almost as much inexperience as Georgia's.
Now, how should I break this down? Positives & Negatives? By position? By random tidbits of information? Let's do this by position, so I can at least show how we have more experience than UGA, since I'm sure that statement above will be taken some sort of way by our rabid sick mutt beloved Dawg brothers.
This position returns the most experience even after losing Akeem Auguste.
The group will be led by veteran corner, Victor Hampton (pictured above). Victor had issues when he first came to Carolina, mostly maturity issues. He was briefly dismissed from the team but returned not long after. Since then, his maturity off the field has been the best you could ask for. He learned his lesson, and has played lights out. He knows the opportunities that are within reach and he will play the best season possible. Will he get beat? I'm sure he will a couple of times. Show me a corner that has never gotten beat… Don't worry, I'll wait.
Also returning, will be Jimmy Legree. Jimmy saw limited action last season in a back up role to Akeem Auguste. He did play while Akeem was injured the first few games of the season. When he was on the field, he impressed. If I remember correctly, he had two pick-6's. He has enough experience and talent that he will hold his own this season.
I guess you can consider this a strength to our team. (Sarcasm, sorry, its a habit…) We return All-World Defensive End, Jadeveon Clowney, but lose the disruptive force of Devin Taylor. Now, last season, Devin Taylor was extremely limited by Brad Lawing, former D-Line Coach. As silly as that sounds, Devin was used primarily to contain on his side. Even sillier, right? Answer me this, how many plays did he make last season? He had more pass deflections than sacks. No slight to him, but he was a victim of the system.
To replace Devin Taylor, we bring in fifth year Senior, Chaz Sutton. Under Deke Adams, expect him to play like there is no tomorrow. Deke will bring a much more aggressive approach, and Chaz Sutton is an excellent pass rusher.
At the other side will be Jadeveon Clowney. That is all.
Clowney registered 13.5 sacks, and 23.5 tackles for loss this past season. After the bowl game, the expectations surrounding him went to heights further than Vincent Smiths helmet. As Drew said in a previous article, it was Vincent Smith, not anyone of note. You're right, but you put ANY runningback into that situation and he is destroyed. When Clowney is in your face before the ball is fully in your hands, I don't care if you're the size of William Perry, you're going down.
Back to Clowney. I expect his expectations to far surpass his actual performance solely due to the fact that there will likely be two or three blockers on him at all times. Enter Chaz Sutton and Kelcey Quarles (more on him later). With the attention Clowney gets, expect the rest of the D-Line (and inexperience Linebackers) to get more one-on-one time. So while I fully expect Clowney to fall short of EXPECTATIONS (not quality play), I also expect the overall performance of the defensive line to rise in meteoric fashion. Let's face it though, when one of your expectations involves on field homicide, it's a good thing you don't rise to the occasion. Expect Gerald Dixon to get some time in rotation.
Defensive TackleThe big guys in the middle. Everyone loves these guys.
The big name among Defensive Tackles at South Carolina, is Kelcey Quarles. This man is huge, I've seen him in person. I wouldn't even want to have him jump on a dog pile. He has a tendency to lose on run plays, but he's still a solid playmaker. Adding yet another year of workouts though could help him in that department. Expect the rotation to include Philip Dukes, Gerald Dixon Jr (yes, there are two Gerald Dixon's on the roster. Same father, different mothers, same name.), and JT Surratt.
Once again, the Defensive Line will be very strong.
Our safety positions return players who all have some experience. Brison Williams locked down the Strong Safety spot last year next to DJ Swearinger, so we are safe there, barring some unforeseen circumstance. TJ Gurley is another safety with experience, he was seen in place of DJ Swearinger while he was suspended a game for a jaw jarring hit. Kadetrix Marcus saw time on special teams, so hopefully he is at least acclimated to the college atmosphere.
Not much worry in the secondary, folks.
Now for the BIG problem.
Linebackers/Spur
http://upload.wikimedia.org/wikipedia/en/f/f5/Question_mark.PNG
We lost five in the Linebacking corps. Not good.
Look for Kelvin Rainey (former tight end, had 6 interceptions in spring training) and Kaiwan Lewis to hold down the Linebacker positions. (SC runs a 4-2-5, thus two linebackers.) Kelvin Rainey will either solidify his position as a Linebacker, or will be overtaken by Ced Cooper when he returns from his injury. Either way, this group has about four tackles worth of experience.
The upside you may ask? Talent. This group is the most physically gifted and talented group USC has recruited under Spurrier. The group WILL be a strength eventually. I doubt it will be August 29th. I'm looking more along the October games to where they start clicking. 2014 by the time they are a true strength.
Now, let's take a glance at the Spur. If you aren't sure what a spur is, it is a Safety/Linebacker Hybrid position. This will be locked down by Sharod Golightly. I assure you one thing about him, he does NOT go lightly. He's a hard hitter, and should be one of the first to really feel at home on the field in this group.
Let me simplify all of this.
Defensive Line: A+
Cornerbacks: A-
Safeties: B
Linebackers: D (B+/A for Talent and Upside)
Spur: B-
I think the way our line plays will be the determining factor of the play of the linebackers. If the line plays to it's potential, it will surely cause mistakes by the offense, which should (hopefully) help the linebackers. The defense has the talent, but this question still remains: When will the Linebackers take the next step and play to the quality of the rest of the defense?
As always, it's Great to be a Gamecock!
JB, signing out.
//Follow me on Twitter @jbarnes24dyc
//E-Mail me at jbarnes24dyc@yahoo.com
Posted in Blog, Georgia Bulldogs, SEC, South Carolina Gamecocks
Tags: SEC, South Carolina, UGA
Georgia plays Clemson in 11 Weeks: It's Going to Rock Like Dwayne Johnson
Clemson's rock broke. Except it's not Clemson's it is actually Howard's. This is devastating to all. The importance of that rock that was used as a doorstop Clemson head coach Frank Howard for years cannot be overstated.
Clemson doesn't stand a chance.
The Rock.
Posted in ACC, Blog, Georgia Bulldogs
Tags: Clemson, UGA


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Correction: Meng, X., et al. Neuroprotective Effects of Radix Scrophulariae on Cerebral Ischemia and Reperfusion Injury via MAPK Pathways. Molecules 2018, 23, 2401
Investigation of the In Vivo Metabolism of Sibirioside A and Angoroside C in Rats by HPLC-ESI-IT-TOF-MSn
El-Taweel, S. H.
Al-Ahmadi, A. O.
Alhaddad, O.
Okasha, R. M.
Cationic Cyclopentadienyliron Complex as a Novel and Successful Nucleating Agent on the Crystallization Behavior of the Biodegradable PHB Polymer
Safaa H. El-Taweel
1,2,*,
Arwa O. Al-Ahmadi
Omaima Alhaddad
Rawda M. Okasha
1,*
Department of Chemistry, Taibah University, 30002 Al-Madinah Al-Munawarah, Saudi Arabia
Chemistry Department, Faculty of Science, Cairo University, Orman-Giza, P.O. 12613, Egypt
Authors to whom correspondence should be addressed.
Molecules 2018, 23(10), 2703; https://doi.org/10.3390/molecules23102703
Received: 30 September 2018 / Revised: 13 October 2018 / Accepted: 15 October 2018 / Published: 19 October 2018
Cationic cyclopentadienyliron (CpFe+) is one of the most fruitful organometallic moieties that has been utilized to mediate the facile synthesis of a massive number of macromolecules. However, the ability of this compound to function as a nucleating agent to improve other macromolecule properties has not been explored. This report scrutinizes the influence of the cationic complex as a novel nucleating agent on the spherulitic morphology, crystal structure, and isothermal and non-isothermal crystallization behavior of the Poly(3-hydroxybutyrate) (PHB) bacterial origin. The incorporation of the CpFe+ into the PHB materials caused a significant increase in its spherulitic numbers with a remarkable reduction in the spherulitic sizes. Unlike other nucleating agents, the SEM imageries exhibited a good dispersion without forming agglomerates of the CpFe+ moieties in the PHB matrix. Moreover, according to the FTIR analysis, the cationic organoiron complex has a strong interaction with the PHB polymeric chains via the coordination with its ester carbonyl. Yet, the XRD results revealed that this incorporation had no significant effect on the PHB crystalline structure. Though the CpFe+ had no effect on the polymer's crystal structure, it accelerated outstandingly the melt crystallization of the PHB. Meanwhile, the crystallization half-times (t0.5) of the PHB decreased dramatically with the addition of the CpFe+. The isothermal and non-isothermal crystallization processes were successfully described using the Avrami model and a modified Avrami model, as well as a combination of the Avrami and Ozawa methods. Finally, the effective activation energy of the PHB/CpFe+ nanocomposites was much lower than those of their pure counterparts, which supported the heterogeneous nucleation mechanism with the organometallic moieties, indicating that the CpFe+ is a superior nucleating agent for this class of polymer.
Keywords: cationic organoiron complex; bacterial Poly(3-hydroxybutyrate) (PHB); nanocomposites; spherulitic morphology; crystal structure; isothermal and non-isothermal crystallization; thermal stability; FTIR analysis cationic organoiron complex; bacterial Poly(3-hydroxybutyrate) (PHB); nanocomposites; spherulitic morphology; crystal structure; isothermal and non-isothermal crystallization; thermal stability; FTIR analysis
The development of biopolymers has attracted great interest over the years as a replacement for petroleum polymers. The key feature of this interest arises from the detrimental impact of traditional polymers on the world's ecosystems. As a result, many researchers seek to exploit the synthesis of polymeric materials from renewable resources that will not persist in the environment after disposal [1,2,3,4]. Successful examples in this field include the synthesis of thermoplastic starch, poly(hydroxyalkanoic acid)s (PHAs), poly(lactic) acid, and their blends or copolymers with other biopolymers [5,6].
Among the poly(hydroxyalkanoic acid)s, polyester of 3-hydroxybutyrate (PHB) is an attractive example of a biodegradable and biocompatible polymer [7,8], which could be accessible via bacteria as intracellular carbon and energy storage compounds and accumulated as granules in the cytoplasm of cells [9,10]. This thermoplastic polymer has also been recognized as one of the most promising biopolymers in packaging and biomedical applications [11,12].
A general comparison of biodegradable polymers to traditional classes revealed certain drawbacks that pose challenges to their commercial applications. For example, in the case of PHB, its manufacturability has been limited due to its stiff and brittle character, narrow processing window, and high cost [13,14,15]. Another obstacle is the slow crystallization rate of PHB [14,15], when processed under conventional injection, molding, and/or extrusion methods, which have resulted in poor dimensional stability and low tackiness.
Several strategies have been reported to overcome some of the aforementioned disadvantages [16,17]. One of these strategies involves the insertion of nucleating agents into the PHB matrix in order to manipulate its crystallization rate, which makes it competitive with synthetic thermoplastic polymers. Various reports have revealed that the addition of nucleating agents to PHB has resulted in a significant improvement in thermal, mechanical, and other physical properties. Examples of these nucleating agents have included the following: NH4Cl [18], melamine [19], boron nitride [20,21], talc [22,23], cyanuric acid [24], cyclodextrin [25], lignin [26], and thermally reduced graphene (TRG) [27]. Recent examples have incorporated nanofillers, such as multi-walled carbon nanotubes [28,29], TiO2, and ZnO nanoparticles [30], graphite nanosheets [31], and WS2 inorganic nanotubes [32].
Despite the prevalence of previous studies that have explored a tremendous number of nucleating agents, this topic continues to be researched in order to overcome the drawbacks that have been associated with such nucleating agents [33,34,35,36,37,38,39,40,41,42,43]. For instance, some of the nucleating agents face an agglomeration issue inside the polymer matrix, which is attributed to the variance in surface energy [35]. This usually occurs with slow solvent evaporation or via the interface of the inorganic filler with the organic polymeric matrix. As a solution, researchers have made several attempts to modify the polymer matrix–filler interface through the incorporation of coupling agents, such as silane, onto the filler surface, which can enhance the interfacial bonding strength of the composites and improved its dispersity [34,44,45]. Meanwhile, examining new classes of nucleating agents remains one of the most successful strategies.
Over the past two decades, our work has been focused on utilizing the cationic cyclopentadienyl iron moieties in designing novel classes of monomeric and polymeric materials [46,47,48,49]. The intense electron withdrawing ability of the positively charged iron center facilitates nucleophilic substitution and addition reactions on the arene rings and allows for the production of these macromolecules under mild conditions. Furthermore, the iron complex demonstrates several advantages over other π-coordinated metallic moieties due to its chemical versatility, stability, low cost, and low toxicity [50,51,52,53].
This work presents the first example of exploring the effect of the CpFe+ complex as a novel nucleating agent on the isothermal and non-isothermal crystallization behavior of PHB using Differential Scanning Calorimetry (DSC) and polarized optical microscopy (POM). The crystallization kinetics and the activation energy have also been analyzed using several models, such as Avrami, Ozawa, a combination Avrami and Ozawa model, and the differential isoconversional method of Friedman.
2.1. Polarized Optical Microscopy
Figure 1 represents the polarized optical micrographs of the PHB and PHB/CpFe+ nanocomposites at the isothermal crystallization condition, 100 °C. The obtained results revealed that the size of the PHB's spherulite was found to be as large as 1 mm, while the spherulite number was extremely small. This behavior could be attributed to the exceptional purity of the PHB that was prepared via bacterial origin [14]. It is also illustrated in Figure 1 that the PHB and PHB/CpFe+ nanocomposites displayed a Maltese cross section with regular extinction rings. The presence of the cationic cyclopentadienyliron (CpFe+) moieties led to the production of smaller spherulites than that existing in the pure PHB, where the CpFe+ nanoparticles were trapped in the center of the spherulites in the form of brown colored dots. Also, the CpFe+ particles were well distributed in the PHB matrix, which is clearly seen in the SEM images in Figure 2. Moreover, increasing the amount of the CpFe+ correspondingly increased the number of small spherulites. These results categorized the CpFe+ as one of the most highly efficient nucleating agents of PHB.
2.2. Scanning Electron Microscope (SEM)
The morphologies of the PHB and PHB/CpFe+ nanocomposites were examined using scanning electron microscope (SEM). Figure 2 elucidates the smooth, fractured surface of the pure PHB. Upon the combination of the cationic iron moieties with the PHB, the images revealed a remarkable distribution of the CpFe+ species without forming agglomerates in the polymer matrix. This behavior remained incessant while increasing the nucleating agent ratio. Additionally, the incorporation of the iron moieties into the polymer matrix triggered the formation of the helical structures of the polymer chains during the crystallization process, which can be observed in some of the SEM images [54,55,56].
2.3. FTIR Analysis
The FTIR spectra of the CpFe+ moiety, pure PHB, and PHB/CpFe+ nanocomposites with a 99:1%, respectively, are illustrated in Figure 3. It is well known that the amorphous melt of the pure PHB can be crystalized during the cooling process, forming an antiparallel helical structure due to the formation of hydrogen bonds within the polymer matrix [55]. Meanwhile, preparing the blend sheets required the cast film samples to be molten between a hot melt press at 200 °C for 2 min. This process allowed for the decomplexation of the arene ring of the cationic iron moieties [47,48,49], which increased the possibility of forming a dipole interaction within the helical structure through the chlorine terminal atoms of the arene rings, as seen in Scheme 1. The decoordination of the arene ring could be confirmed via the FTIR spectra. For instance, the pure cationic cylopentadienyliron complex exhibited an out of plan bending peak, corresponding to the complexed arene C–H at 816 cm−1, while their stretching bands were observed at 469 and 553 cm−1. These peaks were shifted to a higher frequency, 1055 and 1410 cm−1, after the decoordination process and the blending with the PHB polymer; in addition, the spectrum exhibited a disappearance of the complexed arene C–H band at 3097 cm−1. On the other hand, the cyclopentadienyliron moieties became more susceptible to the coordination with the ester carbonyl of the polymer, as seen in Scheme 1. This finding has been verified via the obtained spectra. As can be seen from Figure 3, the characteristic peak at 1719 cm−1 in the pure PHB spectrum was assigned to the ester carbonyl group within the polymer matrix. Upon blending the polymeric materials with the CpFe+ complex, a decrease in the carbonyl stretching frequency was observed while maintaining its value, which confirmed the formation of a chelating complexation to the cationic iron moieties. Furthermore, the frequencies of the complexed cyclopentadienyl C–H stretching band and the CH3 bands of the PHB chains, in the range of 2901–2987 cm−1, were increased after the blending process with the preservation of their values, which supported the complexation behavior of the iron centers towards the PHB matrix
2.4. X-ray Results
Figure 4 shows the X-ray diffractograms of the pure PHB, CpFe+, and the PHB/CpFe+ nanocomposites. The characteristic Bragg reflection peaks of the CpFe+ complex can be observed at 2θ = 19.77, 20.08, and 21.48, which is indexed on the bases of the face centered cubic (FCC) structure of iron and found to be identical to those reported for the standard iron metal. The average crystal size of the CpFe+ was calculated, according to the Scherrer equation, and found to be around 42 nm. However, blending this organometallic complex with the PHB, followed by the thermal processing of the prepared sheets, enhanced the tendency of the iron center to coordinate with the ester carbonyl of the polymer as described previously and illustrated in Scheme 1. This coordination behavior of the CpFe+ was one of major factors that facilitated the excellent distribution of the metallic centers within the polymer matrix. Furthermore, the coordination process led to the disappearance of the diffraction peaks of the CpFe+ moiety at the (021) area. On the other hand, the metallic moieties exhibited a crystal matching with the polymeric materials that was evidenced by the perfect alignment of the diffraction peaks, which can be observed through the growth of its peaks at the (101) and (110) areas. It is also noticeable that the diffraction peaks of the PHB became sharper and narrower than the pure PHB ones with the increasing of the percentage of the iron complex, which is an indication of the increasing crystallinity of the modified polymer. Utilizing the Scherrer equation, the pure PHB exhibited a crystal size of 32.7 nm, while the PHB/CpFe+ nanocomposites displayed crystal sizes of 35.5, 36.8, and 37.2 nm for 0.5%, 1%, and 3% of the CpFe+ nanocomposites. In spite of the fact that the diffraction peaks of the modified polymeric materials retained their values, which suggested that the presence of the metallic moieties did not alter the structure of the polymer, increasing the ratio of the iron moieties reduced the intermolecular interactions between the C=O group and the CH3 group of the PHB due to the formation of a coordination interaction with the CpFe+ complex. This behavior resulted in the increase of the intensity and the narrowing of the (110) peak area with a value of 2θ (16.88°) (marked with asterisk). In order to verify the consistency of this performance, an extra ratio of the CpFe+ (10%) was blended with the PHB. Figure 4 (bottom) elucidates a comparison of the XRD patterns of the PHB blended with 1%, 3%, and 10% of the CpFe+ nanocomposites, which substantiates the previous findings.
2.5. Thermal Properties
The Differential Scanning Calorimetry (DSC) cooling curves of the PHB and its nanocomposites are presented in Figure 5 and exhibited an exothermic peak corresponding to the PHB crystallization. It is well known that a higher value of the crystallization temperature, Tc, is an indication of a faster crystallization rate. The values of the crystallization temperatures (Tc) and the crystallization enthalpy (∆Hc) are reported in Table 1.
The composition of the PHB nanocomposites manipulates the position and shape of the crystallization peak. The presence of the cationic iron (CpFe+) complexes in the PHB matrix resulted in a shift of the crystallization peaks to a higher temperature, Figure 5a, by 26 °C for all the PHB nanocomposites. The crystallization peaks of all the PHB nanocomposites maintained their values upon the addition of different ratios of CpFe+ complexes. These results could be attributed to the presence of the strong interaction between the organoiron centers (CpFe+) and the PHB matrix. As can be seen in Figure 5, the appearance of the crystallization peaks of the PHB nanocomposites became sharper and narrower compared with those of the pure PHB, which demonstrated that the CpFe+ acts as an efficient nucleating agent and suggested that the PHB crystallization occurs through a heterogeneous nucleating mechanism [18,19,20,21,22,23,24,25,26,27,28,29,30,31,32]. Therefore, the values of the ∆Hc for all the PHB nanocomposites were higher than those of the pure PHB. Figure 5b presents the DSC heating curves of the PHB and its nanocomposites, while the values of their glass transition temperature (Tg), cold crystallization temperature (TCC), and melting temperature (Tm) are listed in Table 1. The obtained results revealed that the values of the glass transition temperatures of the PHB and its PHB/CpFe+ nanocomposites were around 2 °C, which was independent of the PHB composition.
It has been established that the heat capacity of the glass transition temperature of amorphous polymers is much higher than those of crystalline ones. Thus, the values of the heat capacities for the PHB in its nanocomposites are lower than those of the pure PHB. Less intense broad exothermic cold crystallization peaks were detected for the nanocomposites during the second heating scan, as shown in Figure 5b and Table 1. These results revealed that the CpFe+ in the PHB nanocomposites prompted almost complete PHB crystallization during a cooling scan with 20 K/min. Meanwhile, above 150 °C, endothermic melting peaks were detected in the second heating scans, as shown in Figure 5b. The pure PHB and the PHB nanocomposites had similar values with respect to melting temperatures. These results indicated that the CpFe+ did not have a significant effect on the crystal structure of the PHB, which was in a good agreement with the XRD results, as shown in Figure 4. A similar trend was reported for the PHB with other nucleating agents [20,26,32,57]. It is worth mentioning that the width of the half height of the melting peak became narrower in comparison to the PHB. The degree of crystallinity was calculated from Equation (1) and reported in Table 1. In conclusion, the DSC results confirmed that the CpFe+ moieties had a significant increase in the degree of crystallinity, which suggests that the CpFe+ is an efficient nucleating agent for the PHB in PHB nanocomposites, as shown in Table 1.
X c = Δ H m − Δ H c c Δ H m ° × w
2.6. Isothermal Crystallization Kinetics
The isothermal crystallization behavior of the pure PHB and its nanocomposites were investigated by rapidly cooling the melt (70 °C/min) to the selected crystallization temperature, ranging from 90° to 128 °C. The exothermic crystallization peaks were recorded as a function of the crystallization time. It is crucial to note that the crystallization peaks were broader at higher crystallization temperatures (Tc), indicating a lower crystallization rate. Figure 6 represents the relative crystallinity (X(t)) as a function of the crystallization time (t/min) at 120 °C, the selected crystallization temperature. X(t) was estimated by the analysis of the heat flow of the isothermal crystallization peaks with time, t , with the following Equation (2):
X ( t ) = ∫ 0 t ∂ H ∂ t dt ∫ 0 ∞ ∂ H ∂ t dt
The numerator represents the integrated heat flow generated until time t, and the denominator is the total heat flow produced in the isothermal crystallization until t = ∞. It can be detected that in the X(t) range, between 0.2 and 0.8, the curves are straight. The isothermal crystallization kinetics of the PHB and its nanocomposites were analyzed based on the Avrami Equation, Equation (3):
X ( t ) = 1 − exp ( − kt n )
The plot of ( log ( − ln ( 1 − X ( t ) ) ) as a function of log(t), derived from Equation (3), creates a linear line with the intercept and slope known as log k and n, respectively. n is the Avrami exponent, k is the overall crystallization kinetic rate constant, and t is the time of crystallization process. The values of k and n depend on the nucleation mechanism and the growth geometry. From Figure 6, it can be concluded that Avrami model, Equation (3), was applicable for describing the isothermal behavior of the PHB nanocomposites.
The crystallization parameters, k, n, and t0.5, are all reported in Table 2. t0.5 is defined as the time at which the relative crystallinity is 50%. As seen in Table 2, t0.5 decreased with the decrease of the crystallization temperature and increased the percentage of the CpFe+ in the PHB/nanocomposites, which is a required behavior for processing the polymer materials. These results indicated that the rate of the PHB crystallization process is faster when the super cooling temperature is higher within the selected crystallization temperature range. At the given crystallization temperature, 120 °C, the t0.5 of the PHB crystallization process in the PHB nanocomposites was much lower than that of the pure analogues, while all the curves of the isothermal crystallization kinetics were almost parallel with each other, as shown in Figure 6. This revealed that the crystallization mechanism of the PHB in its nanocomposites was the same, where their n values were almost constant and approximately equal to 2. The value of n can be attributed to the presence of thermal crystallization during the crystallization process [58]. Another possible explanation reported in the literature [59] is that the PHB crystals can either develop sporadically as rods or instantaneously as disks. The rate constant, k, which is related to both the nucleation and the growth processes, increased with the decrease in the crystallization temperature and the increase of the ratio of the CpFe+ complex. For instance, at 120 °C, the crystallization rate of the PHB with the incorporation of 3 % of the CpFe+ moieties was found to be 87% faster than that of its pure analogue. These results verify the hypothesis that CpFe+ is a superior nucleating agent for this type of polymer.
2.7. Non-Isothermal Crystallization Kinetics
In the polymer processing techniques, the temperature changes continuously. Therefore, investigating the crystallization kinetics under non-isothermal conditions was essential. In general, the exothermic crystallization peak becomes broader and shifts to lower temperatures with the increasing of the cooling rate of all the PHB samples. The dependence of the crystallization temperature (Tc) on the cooling rate for the PHB/nanocomposites is shown in Figure 7.
The attained data disclosed that the crystallization temperature of the PHB in its nanocomposites was higher than those of the pure counterparts for all the studied cooling rates. These results indicated that the enhancement of the crystallization temperature arises from the presence of the CpFe+ moieties. The relative crystallinity X(T) was evaluated from the DSC experimental data in Figure 8 by applying Equation (4), as follows:
X ( T ) = ∫ T 0 T ( ∂ H ∂ t ) ∂ t ∫ T 0 T ∞ ( ∂ H ∂ t ) ∂ t
The T0 and T∞ are the onset and the end crystallization temperature, respectively, and the ∂ H is the enthalpy of the process while the temperature is converted into the time scale, using Equation (5) as follows:
t = | T − T 0 | φ
The T is the temperature at the crystallization time, and the φ is the cooling rate. The relative crystallinity (X(t)) versus the time curves is plotted in Figure 8 where all the curves exhibited the same sigmoidal shape and are shifted to a shorter time with increasing the cooling rates.
The Avrami model [60], the Ozawa model [61], and the combination of the Avrami and Ozawa models (the MO approach) are most frequently used to analyze the non-isothermal experimental crystallization data [62]. Regarding the cooling rate ( φ ), Jeziorny stated that the value of kt should be effectively corrected [63], and it can be calculated by Equation (6), as follows:
log k c = log ( k t ) φ
Figure 9 displays plots of log ( − ln ( 1 − X ( t ) ) ) versus log ( t ) . The non-isothermal parameters, crystallization rate constant ( k t ), and Avrami exponent ( n ) were estimated by inserting the experimental data of the X(t) to be in the range of 0.2–0.8, using Equation (3), as listed in Table 3. The Avrami exponent values, n, for the non-isothermal crystallization process were found to be approximately 3, which was higher than those of the isothermal crystallization for both the pure PHB and PHB nanocomposites.
It is well known that the Avrami equation assumes that during the isothermal crystallization process, the nucleation rate remains constant. However, the nucleation rate is not constant when the PHB samples are crystallized under non-isothermal crystallization conditions [26]. Therefore, the n values for the non-isothermal crystallization kinetics are higher than those under the isothermal ones. This infers that much more complicated processes occur during the melt of non-isothermal crystallization [58]. Other possible explanations that appear in the literature are that n and kt are two adjustable parameters [62,63,64]. Additionally, the kt values, at any given composition, increase by increasing the cooling rate and, at any given cooling rate, increase with the increase in the content of the CpFe+. A similar trend was detected for an inverse half-life time of crystallization, as shown in Table 3.
Combining both the Avrami and Ozawa models was proposed by Liu [62] at a given value of relative crystallinity X(t), as in the following Equation (7):
log ( k ) + n log ( t ) = log ( k 0 ( T ) ) − m 0 log ( φ )
After rearrangement, it became Equation (8):
log ( φ ) = log F ( T ) − b log ( t )
The b is the ratio of the Avrami exponent (n) to the Ozawa exponent (m):
b = n/m
F ( T ) = [ k O ( T ) / k ] 1 m
Figure 10 exhibits log ( φ ) as a function of log(t) at a certain relative crystallinity (20%, 40%, 60%, and 80%) for the PHB/ CpFe+ nanocomposites. A good linearity was achieved for all the PHB samples, as shown in Figure 10. The values of log F ( T ) were determined by the intercept of the lines according to Equation (8) and are reported in Table 4. The F(T) value significantly shifted to higher values with the increase of the degree of the crystallinity. Moreover, for a given X(t), the F(T) values of the PHB/CpFe+ nanocomposites decreased with increase of the CpFe+ content, indicating a pronounced effect of CpFe+.
2.8. An Effective Activation Energy of Non-Isothermal Crystallization
Several models in the literature have been proposed to determine the effective activation energy [65]. The isoconversional model is the most applicable model to evaluate the activation energy under a variety of heating and/or cooling rates [66]. The main assumption of this model is that at a constant relative crystallinity, the reaction rate is only a function of the temperature, as follows in Equation (9):
[ d the ln ( X ( t ) / t ) dT − 1 ] x ( t ) = − E X ( t ) R
The subscript X ( t ) refers to the values corresponding to a given relative crystallinity. Plotting d ln ( X ( t ) / t ) versus dT − 1 at different cooling rates at a given X ( t ) gives a straight line with regression around 0.97. The dependence of the effective activation energy on the relative crystallinity is shown in Figure 11a. It can be discerned that the effective activation energy has a negative value and increases (shifts to a more positive value) with the increase of the relative degree of the crystallinity for the pure PHB and its nanocomposites, Figure 11. This trend was reported previously in the literature.
Vyazovkin [65] stated that the experimental activation energy takes greater negative values at low extents of conversion that correspond to temperatures closer to the melting point. Negative values of the effective activation energy mean that the crystallization rate decreases with increasing temperatures (the anti-Arrhenius process) [67]. Our results showed that the effective activation energy of the pure PHB increased slightly with the extent of the crystallization from −38 to −41 kJ mol − 1 . A similar trend was observed for pure PHB in [68].
In general, the effective activation energy of the pure PHB in its nanocomposites is much lower than that of the pure form. The lowest activation energy value was obtained at the PHB/CpFe+ ratio of 97:3. The reduction of the effective activation energy values in the nanocomposites has been attributed to the occurrence of the heterogeneous nucleation mechanism with the organometallic moieties, which can be distinguished in the polarized optical microscopy images, Figure 1.
The activation energy is closely related to the transport of the macromolecular chains to the growing surface and nucleation steps [65]. Figure 11b elucidates the dependence of the effective activation energy on the average temperature. The average temperature can be estimated by an average crystallization temperature related to a given relative crystallinity. As noticed from Figure 11b, the effective activation energy exhibited more negative values at higher average temperatures, which is consistent with the previous report [65]. The combination of the CpFe+ moieties with the PHB prompted the formation of more nuclei at high crystallization temperatures, which, consequently, has the lowest effective activation energy.
2.9. Thermal Gravimetric Analysis
The thermal stability of the PHB in the nanocomposites was determined using TGA and DTGA, as shown in Figure 12, and summarized in Table 5. The maximum degradation temperature of the pure PHB was achieved at 288 °C. Moreover, the CpFe+ complex was degraded by two steps. The initial degradation step corresponded to the cleavage of the arene ring, while the second step was comprised of the decomposition of the organic moieties. The maxima degradation temperatures of the CpFe+ for the first and second steps were 243 °C and 410 °C, respectively. On the other hand, the PHB/CpFe+ nanocomposites decomposed through a one-step degradation mechanism, which was found to be higher than that of the pure PHB by 10 °C. Furthermore, the thermal degradation temperatures of the PHB/ CpFe+ nanocomposites were almost constant and were independent of their ratios, as shown in Table 5 This result implies that the introduction of the CpFe+ complex improved the thermal stability of the PHB due to the strong chemical interaction, as described previously in the text.
3. Materials and Methods
The pure bacterial Poly(3-hydroxybutyrate) (PHB), in the form of white powder, was kindly provided by Dr. Haenggi, Biomer Company, Germany. The PHB was more than 98%, the content of the polyhydroxyvalerate (PHV) was less than 1%, and the remaining cell membrane and membrane lipids were ca. 1%. The weight average molecular weight was about 600,000 g/mol. The melt flow rate (MFR) at 180 °C with 2.16 kg was 10 g/10 min; methylene chloride (99.9%) was supplied from Sigma Aldrich, Germany. No further purification was performed on the materials. The η6-arene-η5-cyclopentadienyliron complex (CpFe+) was prepared in accordance with the previously reported methodology [69]. The structural identity of the iron complex was confirmed using spectroscopic analysis. For example, the 1H NMR spectrum exhibited two singlet resonances at 5.6 and 6.9 ppm, which corresponded to the equivalent cyclopentadienyl protons and the complexed aromatic arene protons, respectively. In the meantime, the FTIR spectrum displayed an out of plan bending peak, corresponding to the complexed arene C–H at 816 cm−1, while their stretching bands were observed at 3097, 469, and 553 cm−1. Furthermore, the frequencies of the complexed cyclopentadienyl C–H stretching band resonated in the range of 2901–2987 cm−1.
3.1. Preparation of Blends
PHB/CpFe+ composites with different weight ratios were prepared through a casting film technique using methylene chloride as a solvent. For each film, approximately 2.00 g of the total sample were mixed and dissolved in 50 mL of methylene chloride with stirring at 40 °C for 45 min to ensure the complete dissolution of both components. After that, the solution was kept at room temperature for 120 min and then casted onto a glass Petri dish at room temperature to slowly evaporate the solvent and to form homogenously a film. The cast film samples were molten between hot melt press at 200 °C for 2 min. The thickness of the specimen was measured using a digital micrometer and was found to be 0.67 ± 0.01 mm.
3.2. Characterization
The spherulitic morphologies of the samples were examined on an Olympus CX31 polarizing optical microscope (POM) equipped with a digital camera system, E330. Samples weighing 3–5 mg were melted on glass slips with cover slips to form 20–50 mm thick films. Each specimen was melted at 200 °C for 2 min on a hot stage and then was cooled to the selected crystallization temperature of 100 °C. The polarized optical micrographs were recorded after 1 h annealing at the crystallization temperature of 100 °C.
Wide angle X-ray diffraction, XRD, measurements were conducted by a Shimadzu XRD-6100 X-ray diffractometer with Cu-Kα radiation (λ = 0.154 nm, 40 kV, and 30 mA). The X-ray diffraction patterns were carried out at ambient temperature in the 2θ range of 10–80° with a scanning step and rate of 0.02° and 2°/min, respectively.
The transition temperatures of the samples were detected using a differential scanning colorimeter DSC-Q2000 from TA instruments Co. with a Universal Analysis 2000. The DSC temperature and heat flow were calibrated with indium according to the methodology mentioned previously [70]. All the experiments were carried out under a nitrogen atmosphere (30 mL/min). The samples were first heated from −50 °C to 200 °C to eliminate their thermal history and enhance their thermal contact at a heating rate of 20 °C; subsequently, they were cooled to −50 °C at a rate of 20 °C/min and then were reheated to 200 °C at a rate of 20 °C/min (second heating rate). The data of the first heating run are not discussed here. The crystallization temperature ( T C ) and its enthalpy ( Δ H C ) were detected through the cooling curve. The glass transition temperature ( T g ) was estimated as the midpoint of the specific heat capacity step from the second heating run. The cold crystallization temperature ( T C C ), the melting temperature ( T m ), and their enthalpies ( Δ H C C and Δ H m ) were determined from the respective exothermal and endothermal processes in the DSC second heating run. The overall crystallinity ( χ c ) of the PHB in the blend was calculated with Equation (1).
Δ H m and Δ H c c are the experimental melting and cold crystallization enthalpy, respectively. w is the weight fraction of the PHB in the blend, and Δ H m ° is the melting enthalpy of 100% crystalline of PHB, which is taken as 146 J/g [15].
For the study of the non-isothermal crystallization, the samples were heated to 200 °C rapidly and held for 2 min, and then, the DSC curves were recorded during cooling at various cooling rates (5, 10, 15, and 20 °C/min). The crystallization temperature during cooling ( T C ) and the enthalpy of crystallization on cooling ( Δ H C ) were determined from these scans.
Thermogravimetric analysis, TGA, measurements were conducted using a TA Instruments SDT-Q600 thermal analyzer at a heating rate of 20 °C/min under a nitrogen atmosphere with a purge of 20 mL/min from 20 to 700 °C. The sample mass was about 2–5 mg, and it was placed in an alumina crucible.
This study represents the first example of employing the cationic cyclopentadienyliron (CpFe+) complex as a nucleating agent for the enhancement of the properties of the PHB biodegradable polymer. The influence of this metallic complex on the crystallization behavior of the bacterial PHB has been studied profoundly. The new nucleating agent displayed an excellent distribution into the polymer matrix without any sign of agglomeration. Meanwhile, the blending process was assisted by the coordination of the CpFe+ with the ester carbonyl of the polymer chains. Furthermore, the incorporation of the CpFe+ had a multitude of outcomes. For instance, merging the cationic organoiron complex into the PHB materials shifted the melt crystallization temperature 26 °C higher than that of its pure analogue. It also promptly increased the crystallization rate of the bacterial PHB by 87% with no influence on the polymeric crystal lattice. The isothermal and non-isothermal crystallization behaviors of the polymer have been elucidated using the Avrami model, the modified Avrami model, and the combination Avrami and Ozawa model. In addition, the presence of the cationic nucleating agent lowered the effective activation energy of the PHB, owing to its heterogeneous nucleation mechanism with the polymer matrix, which is an indication of a faster crystallization rate that leads to a shortened production cycle time for the polymer processing techniques. All these results signify that the CpFe+ is a superior novel nucleating agent and that the complex has been deemed to be a good candidate for high-temperature polymer processing techniques and commodity applications.
S.H.E.-T. and R.M.O. conceived of and designed the experiments; S.H.E.-T., A.O.A.-A., O.A., and R.M.O. performed the experiments; S.H.E.-T. and R.M.O. analyzed the data and wrote the paper. All the authors discussed the results and commented on the final manuscript.
The authors gratefully acknowledge the Deanship of Scientific Research, Taibah University for the support of this research work with project no. 7023/36. The authors express their gratitude to Nessrin Kattan for her assistance with the XRD and SEM analysis, and finally, the authors also acknowledge Malak T. Mahmoud for her editing assistance.
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Sample Availability: Samples of the compounds are available from the authors.
Figure 1. Polarized light optical micrographs of Poly(3-hydroxybutyrate) (PHB) spherulites of the pure PHB and PHB/CpFe+ nanocomposites with ratios of (a) 100:0, (b) 99.5:0.5, (c) 99:1, and (d) 97:3, respectively, after the isothermal crystallization at 100 °C scale bar 200 µm.
Figure 2. SEM micrographs of the pure PHB and PHB/ CpFe+ nanocomposites with 0.5%, 1%, and 3% of the CpFe+ moieties (right); zoomed-in image of the 97:3% of PHB/CpFe+ (left) that shows the helix structure with x 2200, scale bar 10 µm.
Figure 3. FTIR spectra of the CpFe+ complex, pure PHB, and PHB/ CpFe+ nanocomposites.
Scheme 1. Proposed mechanism of the PHB/CpFe+ interaction.
Figure 4. XRD pattern of pure PHB and PHB/ CpFe+ nanocomposites with ratios of 100:0, 99.5:0.5, 99:1, 97:3 respectively (top). XRD pattern of a higher ratio of CpFe+ 1%, 3%, and 10% (bottom).
Figure 5. DSC curves of the pure PHB and PHB/CpFe+ nanocomposites; (a) cooling curves from the melt at a cooling rate 20 °C/min, (b) second heating curves with a heating rate 20 °C/min.
Figure 6. Relative crystallinity ( X ( t ) ) (right) and its corresponding typical Avrami plot (left) in the isothermal crystallization process for the pure PHB and PHB/ CpFe+ nanocomposites.
Figure 7. A maximum crystallization temperature as a function of a cooling rate for the non-isothermally crystallized pure PHB and PHB/ CpFe+ nanocomposites.
Figure 8. Relative crystallinity as a function of crystallization temperatures and time in the non-isothermal crystallization process for the pure PHB and PHB/CpFe+ nanocomposites at various cooling rates.
Figure 9. Typical Avrami plots of log ( 1 − ln ( 1 − X ( t ) ) versus log ( t ) of the pure PHB and PHB/CpFe+ nanocomposites that non-isothermally crystallized at various cooling rates.
Figure 10. Plots of log ( φ ) versus log ( t ) for the pure PHB and PHB/CpFe+ nanocomposites that non-isothermally crystallized at a given X(t).
Figure 11. Dependence of the effective activation energy of the pure PHB and PHB/CpFe+ nanocomposites on (a) X ( t ) and (b) average temperature.
Figure 12. Thermogravimetry and differential thermogravimetry curves of the pure PHB and PHB/CpFe+ nanocomposites.
Table 1. Thermal parameters of the pure PHB and PHB/CpFe+ nanocomposites from DSC (cool and second heating) curves.
Name of PHB Samples
T c ± 1
Δ H c ± 5
T g ± 2
Δ C p
T c c ± 1
Δ H c c ± 5
T m ± 1
( Δ H m − Δ H c c ) ± 5
χ c
J/g
J/g°C
PHB:CpFe+ 100:0 71 59 3 0.21 95 8 170 72 50
99.5:0.5 97 13 72 2 0.16 105 4 170 7 87 60
99:1 97 13 72 2 0.17 104 7 169 7 86 60
Table 2. Isothermal crystallization kinetics parameters of the pure PHB and PHB/ CpFe+ nanocomposites based on the Avrami model.
logk
k × 10 − 2
t 0.99
min−1
PHB:CpFe+
(100:0) 90 3 −0.23 59. 19 1 1.07 2.1
94 2 −0.24 58.2 1 1.08 2.52
100 2 −0.62 24.01 1 1.71 4.05
118 2 −2.45 0. 35 1 11.5 29
120 2 −2.80 0.16 1 16.7 37.2
124 2 −3.13 0.055 1 19.2 39.3
99.5:0.5 120 2 −1.41 3.88 1 4.05 9.63
124 2 −2.29 0.52 1 9.75 21.4
128 2 −2.98 0.1 1 18.1 38.3
99:1 120 2 −0.99 10.06 1 2.69 6.58
128 2 −2.53 0.29 1 12.7 29
124 2 −1.62 2.37 1 5.4 13.2
128 2 −2.68 0.21 1 13 28.2
Table 3. Non-isothermal crystallization kinetics parameters of the pure PHB and PHB/CpFe+ nanocomposites based on the modified Avrami model.
Δ t i n c
Δ H c
log k t
k t × 10 − 2
K c
CRP × 10 − 2
°C /min
PHB:CpFe+ 100:0 5 16.9 102 83.4 3 −1.3 5.13 0.55 1 2.5 2.72
10 9.14 91 72.1 3 −0.86 13.83 0.81 1 1.8
99.5:0.5 5 15.7 112 91.5 3 −0.99 10.06 0.63 1 2 6.36
10 8.09 109 87.9 3 −0.24 58.16 0.91 1 1.1
15 5.53 105 85.4 3 0.11 131.2 0.99 1 0.8
99:1 5 15.6 112 93.8 3 −0.97 10.71 0.64 1 1.9 5.12
10 8.07 107 87.4 3 −0.35 44.5 0.92 1 1.2
97:3 5 15.8 113 90.9 3 −0.90 12.49 0.66 1 1.8 6.5
10 8.06 110 85.8 3 −0.15 70.08 0.97 1 1
15 5.5 106 84 3 0.17 148.3 1.02 1 0.8
20 4.21 104 81.9 3 0.4 251.7 1.05 1 0.6
Table 4. F ( T ) and b values by MO approach for pure PHB and PHB/CpFe+ nanocomposites.
Kinetics Parameter
X ( t )
PHB:CpFe+ 100:0 F ( T ) 15.83 23.59 29.10 33.80
b −1.56 −1.52 −1.45 −1.36
R 2 0.997 0.993 0.993 0.995
99.5:0.5 F ( T ) 7.239 8.903 10.047 11.122
b −1.496 −1.509 −1.522 −1.522
99:1 F ( T ) 6.978 8.669 9.825 10.889
97:3 F ( T ) 6.546 7.965 8.940 9.882
Table 5. Thermal stability parameters of PHB and PHB/ CpFe+ nanocomposites.
PHB Phase
T o n s e t
T m a x
T e n d
PHB:CpFe+ 100:0 280 288 293
99.5:0.5 287 297 303
99:1 287 297 303
90:10 287 300 306
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text:
Primary School Geography Encyclopedia
Reading Maps
Weather in the UK
Types of Settlement
Secondary Industries
UK Commodities and Trade
Comparing Lancashire and Yorkshire
Environmental Issues at Seaside Resorts
The Lake District National Park
Islands of Greece
Landscape of Italy
Climate of Italy
Food and Drink in Italy
Landmarks in Italy
Settlements in Spain
Farming and Tourism in Spain
Landscape and Climate
The Amazon River
The Mississippi River
Water Supplies
The Source of a River
The River Profile
Streams and Rapids
Meanders
Flood Plains and Flooding
The Mouth of a River
The River Severn
The Longest Rivers
Uses of Rivers
The Structure of the Earth
Types of Rocks
Rocks and the Landscape
Uses of Rocks
Types of Soils
Climate Types
Physical Factors Affecting Climate
Equatorial Regions
The Kayapo Tribe
Savanna Regions
Monsoon Regions
Polar and Tundra Regions
Changing Land Use
World Countries > United States of America >
Florida is the most south-eastern state in the USA and is located on a peninsula (surrounded on three sides by water). Nicknamed 'the Sunshine state', it is famous for its palm trees and hot climate (with average July temperatures of about 32oC).
Whilst Florida is a very flat state with no mountains, it does have a very long coastline with lots of beaches, such as Miami Beach and Palm Beach where people like sunbathing and surfing. At the southernmost tip of Florida is a chain of 4,500 islands called the Florida Keys which are also popular holiday destinations.
The Everglades National Park is located in south Florida. It is mostly covered in swamp lamp and lots of animals like: the American alligator, Florida panther and the manatee live there.
Orlando is a large city located in the centre of Florida and is where many theme parks have been built, including: Walt Disney World Resort, Universal Orlando Resort and SeaWorld. Tourism is the largest industry in Florida, with over 60 million people visiting each year.
The Kennedy Space Centre, where many NASA space flights have been launched, is also a popular attraction.


An Ambidextrous Gaming mouse with laser sensor with a shockingly brilliant 8200 DPI.
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More links for "**B Grade** Krypton Dual Chassis Gaming Mouse - Black/Blue"


See how SW Audio Visual supported the seventh FIFA Women's World Cup in Vancouver BC, a 24 team international football tournament with 52 matches over 30 days.
SW facilitated all stadium press center services for representatives of the international media, including staging, audio, TV lighting, press feed audio distribution, simultaneous interpretation and many more services. SW also provided distributed multichannel video feeds to over 120 televisions in the venue and provided large LED screens for the FIFA Fan Zone.


AWith our Africa Airways series flying high we felt it is time to introduce a new compilation focusing on the unique contribution from some of Africa's most recognised female artists and some lesser known ones for good measure. We are excited to be launching this on Women's Day 2018 as our way to highlight the incredible, yet under-acknowledged musical contribution that African women have given to the funky sounds of Africa. Taking our cue from the Alice Walker essay "In Search of Our Mothers' Gardens", the creative sparks that inspired this collection of songs were formed in their Mothers' Gardens by Mothers who paved the way for their daughters to keep the creativity of black women alive through their strength and resilience. Whilst we have a bit more of a message with this one, we wouldn't be Africa Seven if it wasn't damn funky at the same time!
We kick things off with the infectious sound of South-African Letta Mbulu. Letta started her career playing alongside fellow heavyweights Miriam Makeba and Hugh Masekela as cast members of King Kong in the 1950's and has since gone on to become one of the most influential south-African artists, even featuring on Michael Jackson songs, as well as being recognised for her contribution both musically and to that of the country's liberation struggles. With a crate-digger, secret weapon version of her classic Kilimanjiro single, "Kilimanjiro, Take Us Higher" is longer and has all the disco groove and delight you need and desire from such a star.
Uta Bella takes over from Letta, with a powerful Africa Seven return. "Enyin" is a glamorous disco scorcher heightened by glittering keys and irresistible West African vocals. One of Nigeria's unsung pioneers, and first female pop bandleader, Mona Finnih continues the flow with an effortless boogie number "Ani Kewa Jo" which just keeps on giving for nearly 7 glorious minutes. This devastating 80's number "Nou Ke Sa Inmew" from Cida Desvarieux follows up Uta and is dealt in two halves. Firstly a hit of beautiful vocals and slap bass controls the floor before handing over to the powerful guitar riffs and horns which groove out for the rest of this number. Wrapping up the first side with a classy reggae inspired number "Time Waits For No One" is Christy Essien, the grand dame of Nigerian pop, who was never far away from the issues affecting women in the Nigerian music industry.
Side two, enter Togolese singer Akofa Akoussah causing a storm with "Tango", delicate at times yet with a ferocious, unforgiving energy. Next a more obscure offering from Carmen Ezumah with vintage afro goodness in the form of "Tala Tala". Moving on, we have the Nigerian Lijadu sisters (dubbed "the West African Pointer Sisters") with one of their most notable hits "Danger". Our penultimate offering is another dose of obscurity, sandwiched between two greats, with Kenyan Bakambi N'Kela's uncompromising "Kilimanjoro".
Mothers' Garden finishes the way we started. With another one of Africa's leading ladies and music royalty, Miriam Makeba. Nicknamed Mother Africa, Miriam is famed for her huge musical contributions, her role in fighting the apartheid and for becoming a UN Ambassador. "Xica Da Silva" is a cover of Jorge Ben and the slow, hypnotic rhythm allows for the power of Miriam's voice to shine through.


This was our best game so far this season against a strong gowerton side the boys offloading skills was very good on the day with fast hands and good skill levels which the boys have been working hard on in training.
The forwards were making some seroius yards and carrying well into the defensive line and braking the gain line which was very good to see.
Both coaches was happy with the boys for the effort shown in attack and going forward however we gave away two very soft tries straight from kick off which we must address apart from those missed tackles the boys were good in defense.
More of the same boys please.


text:
Amazon's First NFL Streaming Season Big Success
By Thoinot Arbeau
Judging by the success Amazon's first NFL Streaming Season had, it seems that the media house had made a good call. It seems that Amazon has set out to conquer the sports programming market, as it has already disclosed plans to bid for Premier League streaming rights. On top of that, its recent partnership with CBS, among other things, seems like another move in the same direction. But, nothing is certain for now.
Amazon's First NFL Streaming Season: Is It the Last?
The question to ask right now is whether Amazon is serious about sports. We can draw the answer to this question from a recent interview the head of Amazon Sports gave. In this interview, contrary to all of the signs, he said that nothing is yet set in stone. He added that Amazon Sports is still "in the early stages" and we have to wait and see how things are going to develop. He concluded by saying that he is happy with how things are progressing so far, as well with the response Amazon customers have had.
Amazon has already had a taste of sports programming before, especially with tennis in the United Kingdom. However, this is the biggest investment in this field so far, with $50 million paid for 10 games, plus one bonus game on Christmas.
What Viewers Thought About Amazon NFL Streaming
The audience generally seemed to like the development of Amazon streaming a lot. On average, the most loyal sports audience was in the District of Columbia, Utah, Oregon, Colorado, and Washington. Already loyal viewers who spend much time on Amazon Prime, spent the most time on NFL, 63 minutes on average.
Another thing that viewers liked a lot was the quality of the stream. Contrary to what usual online streaming sometimes look like, this one was pristine. Viewers report that the Amazon NFL stream was better quality than that on Twitter and other streaming services. On top of that, some report that it was even faster and more responsive than some Cable Televisions.
Sports are definitely a streaming programming option that will not vanish anytime soon. No wonder then that Amazon's first NFL streaming season was a huge success. Have you contributed to it? If not, which other sports would you like Amazon to cover in the future? Give us your answers below.


Get ready to party and kick up your paws with this designer Embroidered Shamrock Dog Collar by Mirage!
The Embroidered Shamrock Dog Collar will have your dog surrounded with the luck! Collar is made of faux leather with shamrock embroidered design. Buckle collar to adjust to the length needed with no slipping. Great for St. Patrick's Day and year round for your Irish loving dog!
The Shamrock dog collar (ultra cool !!!
Posted On 04/26/17 by Shelley Huber from Live Oak, FL Yes, Shelley Huber recommends this product!
Posted On 02/05/17 by Tiffany P from Fort Myers , FL Yes, Tiffany P recommends this product!
Perfect durable collar for my dog to wear for st. Patrick's day!
Love the site, but some of the pictures are very limited. You should definitely consider putting up more pics of each product, as dogs are so different in shape and size, with the pics on you site it is very difficult to determine the fit of the item.


text:
Founding of the 13 American Colonies
The Thirteen Colonies were the British Colonies on the Atlantic coast of North America founded between 1607 (Virginia) and 1733 (Georgia). Individual colonies began collaborating at the Albany Congress of 1754 to demand more rights and set...
John Harvard, Namesake of Harvard College
John Harvard was an English minister in America, "a godly gentleman and a lover of learning", whose deathbed bequest to the "schoale or Colledge" recently undertaken by the Massachusetts Bay Colony was so gratefully received that it was con...
Jan Lievens, Dutch Painter
Jan Lievens was a Dutch painter, usually associated with Rembrandt, working in a similar style. In his early years he was a student of Pieter Lastman in Amsterdam. After two years he began his career as an independent artist at age of fourt...
Michiel de Ruyter, Dutch Admiral
Michiel Adriaenszoon de Ruyter is the most famous and one of the most skilled admirals in Dutch history. De Ruyter is most famous for his role in the Anglo-Dutch Wars of the 17th century. He fought the English and French in these wars and s...
Anna Maria van Schurman, Female Scholar
Anna Maria van Schurman was a German-born Dutch painter, engraver, poet, and scholar, who is best known for her exceptional learning and her defense of female education. A highly educated woman by seventeenth century standards, she excelled...
Holy R. Emperors
Ferdinand III of Hapsburg
Ferdinand III of Hapsburg, Holy Roman emperor (1637 – 57), archduke of Austria (1621 – 57), king of Hungary (1625 – 57) and king of Bohemia (1627 – 57). Denied command of the Habsburg armies in the Thirty Years' War, Ferdinand conspired to...
John Milton, Writer of Paradise Lost
John Milton was an English poet, polemicist, and civil servant for the Commonwealth of England. He is best known for his epic poem Paradise Lost. He was a scholarly man of letters, a polemical writer, and an official serving under Oliver Cr...
Frederick III, King of Denmark and Norway
Frederick III was king of Denmark and Norway from 1648 until his death. He also governed under the name Frederick II as diocesan administrator (colloquially referred to as prince-bishop) of the Prince-Bishopric of Verden (1623–29 and again...
Jacob van Wassenaer Obdam, Admiral
Jacob, Banner Lord of Wassenaer, Lord Obdam, Hensbroek, Spanbroek, Opmeer, Zuidwijk and Kernhem, was a Dutch Lieutenant-Admiral, and supreme commander of the confederate Dutch navy. The name Obdam was then also spelled as Opdam. British con...
Stuyvesant, Governor New York - 1646
Peter Stuyvesant served as the last Dutch director-general of the colony of New Netherland from 1647 until it was ceded provisionally to the English in 1664, after which it was renamed New York. He was a major figure in the early history of...
Adriaen van Ostade, Dutch Painter
Adriaen van Ostade was a Dutch Golden Age painter of genre works. He and his brother were pupils of Frans Hals and like him, spent most of their lives in Haarlem. In 1662 and again in 1663 he is registered as deacon of the St. Luke guild...
D'Artagnan, The Three Musketeers
Charles Ogier de Batz de Castelmore, Comte d'Artagnan served Louis XIV as captain of the Musketeers of the Guard and died at the Siege of Maastricht in the Franco-Dutch War. A fictionalized account of his life by Gatien de Courtilz de Sandr...
Pope Innocent XI
Pope Innocent XI, born Benedetto Odescalchi, was Pope from 1676 to 1689. Odescalchi was a strong papal candidate after the death of Pope Clement IX (1667–69) in 1669, but the French government rejected him. After Pope Clement X (1670–76) di...
Bartholomeus van der Helst, Dutch Painter
Bartholomeus van der Helst was a Dutch portrait painter. In Amsterdam Van der Helst was a contemporary of Rembrandt. He soon became the most popular painter of portraits in that city, his flattering portrayals in the style of Anthony van Dy...
Gerrit Dou, Painter
Gerrit Dou, also known as Gerard and Douw or Dow, was a Dutch Golden Age painter, whose small, highly-polished paintings are typical of the Leiden fijnschilders. He specialised in genre scenes and is noted for his trompe l'oeil "niche" pain...


I have some quick artwork to show you this morning. Do you remember that it is National Scrapbooking Day tomorrow? We are celebrating the whole weekend at Archiver's, so I am on my way to work. Lots of fun things going on in a lot of places for NSD!
The first project I am showing you fits into two challenges - Tuesday Trigger at Moxie Fab (the picture below) and the Heart 2 Heart challenge which is using two ribbons.
This next project is an altered canvas. You can pick them up at our local craft stores in a variety of sizes. I needed a gift, and I thought this would be lovely. First I sprayed the canvas with wheatfields glimmer mist. It's such a nice base for additional work. From there, I used a glimmer screen and sprayed again with moonlight glimmer mist. I did the same with the flowers - two coats of glimmer mist. The letter was cut with my Slice, and I covered it with glossy accents for extra shine.
Finally, I put together a page with some photos we toook of Chanel last week. What a cutie!! I've used Bo Bunny papers for this, AC Thickers, CTMH ribbon, and some random accessories. You have to admit this is a way cute picture of our beagle sleeping with her favorite toy!!
I'll be back later this evening to check out what everyone is up to today!!
Wow, you are amazing! these are gorgeous.
Simply wonderful! I love those flowers you used sweetie!
love the hardware you used on the trigger card!
Beautiful cards and layout, and as usual, you blow me away with your talent with flowers.
I love your H2H card, and the altered canvas is out of this world! I really need to get out my glimmer mists and try something on a canvas. This is an inspiration!
Thanks for playing along with H2H this week. Your card is beautiful! Love the canvas as well! I bought some a few days ago, just haven't played with them yet. Thanks for the inspiration!
Wow your projects are all beautiful! Thanks for playing along with us at Heart 2 Heart Challenges!
Nice projects. Love the H2H challenge entry. And...BEAGLES!!!! We have 2 Beagles. Can't have stuffed toys - the younger one would destroy them. Beagles are the BEST!


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In a House of Lies
A cold case involving a missing private investigator threatens to unearth skeletons from Rebus's past in this "must-read" mystery (Tana French).
Former Detective John Rebus' retirement is disrupted once again when skeletal remains are identified as a private investigator who went missing over a decade earlier. The remains, found in a rusted car in the East Lothian woods, not far from Edinburgh, quickly turn into a cold case murder investigation. Rebus' old friend, Siobhan Clarke is assigned to the case, but neither of them could have predicted what buried secrets the investigation will uncover.
Rebus remembers the original case -- a shady land deal -- all too well. After the investigation stalled, the family of the missing man complained that there was a police cover-up. As Clarke and her team investigate the cold case murder, she soon learns a different side of her mentor, a side he would prefer to keep in the past. A gripping story of corruption and consequences, this new novel demonstrates that Rankin and Rebus are still at the top of their game.
PUBLISHERS WEEKLY OCT 29, 2018
The discovery of the body of Stuart Bloom, who went missing in 2008, in his car trunk in an isolated wooded area drives Edgar finalist Rankin's intricate 24th Rebus novel (after 2017's Rather Be the Devil). Bloom's ankles being secured with police handcuffs raises questions about the original, possibly corrupt police investigation into the man's disappearance. Semiretired copper John Rebus isn't afraid to step on official toes as he assists Det. Insp. Siobhan Clarke, Det. Insp. Malcolm Fox, and the other members of Police Scotland's Major Crime Division in their efforts to find Bloom's killer. Their attention focuses on low-budget film producer Jackie Ness, who shot a movie called Zombies v Bravehearts in 2008 on the land where the car was found and in which Bloom served as an extra. Meanwhile, Rebus reopens the case of 17-year-old Ellis Meilke, who was sent to prison for the stabbing murder of his girlfriend. In both cases, the path to justice involves making some hard ethical choices. Rankin remains a master of the contemporary police procedural. Author tour.
More Books by Ian Rankin
Knots and Crosses
The Complaints
Standing in Another Man's Grave
Resurrection Men
Saints of the Shadow Bible


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Osteogenesis imperfecta (OI) is a disease that causes weak bones that break easily. It is known as brittle bone disease. Sometimes the bones break for no known reason. OI can also cause many other problems such as weak muscles, brittle teeth, and hearing loss. About 20,000 to 50,000 people in the United States have OI.
What Causes Osteogenesis Imperfecta?
OI is caused by one of several genes that aren't working properly. Genes carry our hereditary (family) information. We each have two copies of most genes: one set from each parent. Genes are what make you look like your biological family.
Each of the genes that cause OI plays a role in how the body makes collagen. Collagen is a material in bones that helps make them strong. When these genes aren't working properly, there isn't enough collagen, or the collagen doesn't work properly. This leads to weak bones that break easily.
Most children inherit the gene that doesn't work properly from one parent. Some inherit it from both parents. In some cases, neither parent passes on this gene. Instead, the gene stops working properly soon after the child is conceived.
What Are the Symptoms of Osteogenesis Imperfecta?
All people with osteogenesis imperfecta have brittle bones. OI can range from mild to severe and symptoms vary from person to person. Some of the symptoms that people with OI may have are:
Malformed bones
Short, small body
Sclera (whites of the eyes) that look blue, purple, or gray
Triangular face
Barrel-shaped rib cage
Curved spine
Brittle teeth
Hearing loss (often starting in 20s or 30s)
Type 1 collagen that does not work well
Not enough collagen.
What Are Some Types of Osteogenesis Imperfecta?
There are 8 main types of osteogenesis imperfecta. People with types 2, 3, 7, and 8 tend to have severe symptoms. People with types 4, 5, and 6 tend to have more moderate symptoms. People with type 1 tend to have mild symptoms.
How Is Osteogenesis Imperfecta Diagnosed?
No single test can identify osteogenesis imperfecta. To diagnose OI, doctors look at:
Results from a physical exam
X rays.
Your doctor may also test your collagen (from skin) or genes (from blood). It may take a few weeks to learn the results of the tests. These tests spot OI in 9 out of 10 people who have it.
How Is Osteogenesis Imperfecta Treated?
Although there is no cure for OI, symptoms can be managed. Treatments for OI may include:
Care for broken bones
Care for brittle teeth
Use of wheelchairs, braces, and other aids
One type of surgery is called "rodding." Metal rods are put inside the long bones to:
Strengthen them
Fix bone malformations
Prevent bone malformations.
A healthy lifestyle also helps people with OI. You can help prevent broken bones and maintain your health if you:
Exercise (swimming, water therapy, walking)
Eat a balanced diet
Do not drink a lot of alcohol and caffeine
Do not take steroid medicines.
Proper care helps children and adults who have OI to:
Make bones more dense
Keep muscles strong.
What Research Is Being Done on Osteogenesis Imperfecta?
No medications are approved to treat OI. But, experts are trying to learn more about:
Genes that cause OI.
Medications to help people with OI grow.
Drugs to make bones stronger.
Better devices to use in surgery.
-NIH


The Mini 2 is cylindrical dash cam from the Chinese manufacturer DDPai. This camera has nearly identical specifications as the popular DDPai M6 Plus but there are some key differences. The DDPai Mini 2 is based on the same HiSilicon Hi3516D processor and Omnivision OV4689 CMOS sensor as the M6 Plus. This combination allows for 1440p at 25fps, 1296p at 30fps or 1080p at 30fps recording. Bit rate is not the highest at approximately 10.5Mbps.
Video quality during the day is very good and at night it is good. Like the M6 Plus, owners are quite pleased with the video quality from this camera. While the night time video is bright, the footage is more grainy / noisy then competing cameras like the A119.
The camera comes with WiFi and G-Sensor but no LCD screen. A small remote button is provided as well. When pressing the remote button, the camera will save a 10 second clip (5 seconds before the incident and 5 seconds after) and sends this video to your smartphone automatically via WiFi. Note that downloading the video clips via WiFi to your phone will save the files on the phone's internal memory not on a phone's SD card if available.
Like the M6 Plus, the Mini 2 comes with time-lapse parking mode which records 1 fps while the car is parked. In parking mode the camera records at 20Mbps and draws approximately the same amount of power as if the camera was operating normally. There have been some complaints that the camera runs hot during parking mode.
Overall some advantages over the M6 Plus but also some disadvantages. We would like to thank our members Yooshaw and runtohell121 for providing detailed reviews of this camera in our forum.
Like the M6 Plus, you can connect the Mini 2 with the Mini 1 via WiFI to work as a dual camera system. (NOTE: The Mini 2 or another M6 Plus will NOT work as a dual camera system – apparently you cannot have 2 cameras with the same processor for this to work). This essentially creates a wireless dual camera set-up. You can pair the cameras by putting the remotes next to each other and clicking both 5 times.
Our member Yooshaw provided the following photo comparing the size of the SG9665GC (left), DDpai Mini 2 (middle) and Mobius (right).
Some owners have complained that the camera records blocky video when in parking mode. This typically happens in hotter temperatures and when recording at 1440p. There is no known solution to this problem.
Some owners indicate that the camera will occasionally reboot while driving or in parking mode. One possible reason is that when the camera overheats, it restarts. No known solutions exist for this problem.
The DDPai Mini 2 has similar specs and video quality to the popular DDPai M6 Plus but with a cylindrical shape, no GPS and capacitor instead of battery. At the lower price point of approximately $100, the camera at first site appears to be a reasonable buy. However, initial reliability is a bit concerning especially if you are looking to use this camera in a hot climate.
See what other owners have to say about the DDPai Mini 2 on our forum.
Final Word Video quality is good but initial reliability is a concern if you are using this in a hot climate.