Pham H.H.,MST Inc |
Taylor C.D.,MST Inc |
Henson N.J.,Los Alamos National Laboratory
Journal of Physical Chemistry B | Year: 2013
We introduce a procedure of quantum chemical calculations (B3P86/6-31G**) to study carboxylic acid dimerization and its correlation with temperature and properties of the solvent. Benzoic acid is chosen as a model system for studying dimerization via hydrogen bonding. Organic solvents are simulated using the self-consistent reaction field (SCRF) method with the polarized continuum model (PCM). The cyclic dimer is the most stable structure both in gas phase and solution. Dimer mono- and dihydrates could be found in the gas phase if acid molecules are in contact with water vapor. However, the formation of these hydrated conformers is very limited and cyclic dimer is the principal conformer to coexist with monomer acid in solution. Solvation of the cyclic dimer is more favorable compared to other complexes, partially due to the diminishing of hydrogen bonding capability and annihilation of dipole moments. Solvents have a strong effect on inducing dimer dissociation and this dependence is more pronounced at low dielectric constants. By accounting for selected terms in the total free energy of solvation, the solvation entropy could be incorporated to predict the dimer behavior at elevated temperatures. The temperature dependence of benzoic acid dimerization obtained by this technique is in good agreement with available experimental measurements, in which a tendency of dimer to dissociate is observed with increased temperatures. In addition, dimer breakup is more sensitive to temperature in low dielectric environments rather than in solvents with a higher dielectric constant. © 2012 American Chemical Society.
Infarct tissue characterization in implantable cardioverter-defibrillator recipients for primary versus secondary prevention following myocardial infarction: A study with contrast-enhancement cardiovascular magnetic resonance imaging
Olimulder M.A.G.M.,MST Inc |
Kraaier K.,MST Inc |
Galjee M.A.,MST Inc |
Scholten M.F.,MST Inc |
And 5 more authors.
International Journal of Cardiovascular Imaging | Year: 2013
Knowledge about potential differences in infarct tissue characteristics between patients with prior life-threatening ventricular arrhythmia versus patients receiving prophylactic implantable cardioverter-defibrillator (ICD) might help to improve the current risk stratification in myocardial infarction (MI) patients who are considered for ICD implantation. In a consecutive series of (ICD) recipients for primary and secondary prevention following MI, we used contrast-enhanced (CE) cardiovascular magnetic resonance (CMR) imaging to evaluate differences in infarct tissue characteristics. Cine-CMR measurements included left ventricular end-diastolic and end-systolic volumes (EDV, ESV), left ventricular ejection fraction (LVEF), wall motion score index (WMSI), and mass. CE-CMR images were analyzed for core, peri, and total infarct size, infarct localization (according to coronary artery territory), and transmural extent. In this study, 95 ICD recipients were included. In the primary prevention group (n = 66), LVEF was lower (23 ± 9 % vs. 31 ± 14 %; P < 0.01), ESV and WMSI were higher (223 ± 75 ml vs. 184 ± 97 ml, P = 0.04, and 1.89 ± 0.52 vs. 1.47 ± 0.68; P < 0.01), and anterior infarct localization was more frequent (P = 0.02) than in the secondary prevention group (n = 29). There were no differences in infarct tissue characteristics between patients treated for primary versus secondary prevention (P > 0.6 for all). During 21 ± 9 months of follow-up, 3 (5 %) patients in the primary prevention group and 9 (31 %) in the secondary prevention group experienced appropriate ICD therapy for treatment of ventricular arrhythmia (P < 0.01). There was no difference in infarct tissue characteristics between recipients of ICD for primary versus secondary prevention, while the secondary prevention group showed a higher frequency of applied ICD therapy for ventricular arrhythmia. © 2012 The Author(s).
McCabe R.J.,MST Inc |
Beyerlein I.J.,Los Alamos National Laboratory |
Carpenter J.S.,MST Inc |
Mara N.A.,MST Inc |
Mara N.A.,Los Alamos National Laboratory
Nature Communications | Year: 2014
Numerous recent studies have focused on the effects of grain size on deformation twinning in nanocrystalline fcc metals. However, grain size alone cannot explain many observed twinning characteristics. Here we show that the propensity for twinning is dependent on the applied stress, grain orientation and stacking fault energy. The lone factor for twinning dependent on grain size is the stress necessary to nucleate partial dislocations from a boundary. We use bulk processing of controlled nanostructures coupled with unique orientation mapping at the nanoscale to show the profound effect of crystal orientation on deformation twinning. Our theoretical model reveals an orientation-dependent critical threshold stress for twinning, which is presented in the form of a generalized twinnability map. Our findings provide a newfound orientation-based explanation for the grain size effect: as grain size decreases the applied stress needed for further deformation increases, thereby allowing more orientations to reach the threshold stress for twinning. © 2014 Macmillan Publishers Limited. All rights reserved.
Zheng S.,Los Alamos National Laboratory |
Beyerlein I.J.,Los Alamos National Laboratory |
Carpenter J.S.,MST Inc |
Kang K.,Los Alamos National Laboratory |
And 4 more authors.
Nature Communications | Year: 2013
Bulk nanostructured metals can attribute both exceptional strength and poor thermal stability to high interfacial content, making it a challenge to utilize them in high-temperature environments. Here we report that a bulk two-phase bimetal nanocomposite synthesised via severe plastic deformation uniquely possesses simultaneous high-strength and high thermal stability. For a bimetal spacing of 10 nm, this composite achieves an order of magnitude increase in hardness of 4.13 GPa over its constituents and maintains it (4.07 GPa), even after annealing at 500C for 1 h. It owes this extraordinary property to an atomically well-ordered bimaterial interface that results from twin-induced crystal reorientation, persists after extreme strains and prevails over the entire bulk. This discovery proves that interfaces can be designed within bulk nanostructured composites to radically outperform previously prepared bulk nanocrystalline materials, with respect to both mechanical and thermal stability. © 2013 Macmillan Publishers Limited. All rights reserved.
Prakash S.,MST Inc |
Puri V.K.,SIU |
NCEE 2014 - 10th U.S. National Conference on Earthquake Engineering: Frontiers of Earthquake Engineering | Year: 2014
Foundations failures have been observed during several earthquakes because of excessive settlement and tilt. The problem of settlement due to dynamic loads has been the subject of research since early sixties. Shallow foundations subjected to static and seismic loads have mostly been designed using pseudo-static approach, the settlement and tilt of the foundation was also calculated using the static methods. Empirical equations for calculation of settlement and tilt of foundations subjected to static loads and moments have also been used for estimating the settlement and tilt for the seismic case. Earlier studies have indicated that the cyclic shear stresses induced by the earthquake ground motion are the main cause of seismic settlements. Vertical accelerations generally do not result in significant settlements unless they exceed about 1g. The research effort has therefore been directed towards determining the shear strains induced in the soil deposits and correlating these strains with the settlements. Simplified procedures similar to ones used for liquefaction analysis have also been used for estimating shear strains in soil deposits due to earthquake which is assumed equal to volumetric strain. The settlement can then be estimated using the volumetric strain and the thickness of the deposit. For the case of a layered deposit, the strain in each layer may be calculated and total settlement obtained as the cumulative settlement. The settlement calculated in this manner generally represents the settlement of soil deposits in the free field i.e. as if the structure was not there. The foundation may experience additional settlement due loads and moments imposed on the foundation by the earthquake. There has been considerable research effort devoted to estimate these additional settlements by considering the reduction in shear modulus of soil by induced shear strains. The total settlement of the structure due to earthquake shaking may be obtained as the sum of these two components of settlement. Charts based on simplifying assumptions are available to determine the post volumetric strain for soils, both non-liquefiable and likely to liquefy using the normalized standard penetration data or relative density of sand and the factor of safety against liquefaction.
MST Inc | Date: 2011-07-05
Wall plaques made of plastic or wood. Athletic apparel, namely, shirts, pants, jackets, footwear, hats and caps, athletic uniforms; Baseball caps; Baseball caps and hats; Golf shirts; Hooded sweat shirts; Long-sleeved shirts; Night shirts; Shirts; Shirts and short-sleeved shirts; Short-sleeved or long-sleeved t-shirts; Short-sleeved shirts; Sleep shirts; Sport shirts; Sweat pants; Sweat shirts; T-shirts; Wearable garments and clothing, namely, shirts; Wind shirts.
MST Inc | Date: 2011-08-23
News Article | May 26, 2015
4K, or UHD as it's otherwise known, has come a long way since the Asus PQ321 monitor launched at an eye-watering $3500 (~£2300) back in 2013. These days, adding a decent 60Hz 3840×2160 monitor to your gaming setup can cost as little as £350 (~$500), provided you can deal with lesser TN panels over their mostly superior, but far pricier IPS and IGZO counterparts. Aside from the benefits of a larger workspace, or increased sharpness with desktop scaling, the PC—and not the console—is the only place where you can game at native 4K, and at a distance where such a high resolution makes a visible difference. While you can technically play almost any PC game at 4K, doing so is an enormous strain on resources. Despite huge advances in GPU technology, 4K is still very much the realm of the enthusiast, where £500 (~$700) graphics cards are all but required to play the latest games. That's not to say you can't play in 4K with a mid-range card, but it all depends on the sacrifices you're willing to make to rendering quality and frame rate in exchange for all those extra pixels. For a lot of people, myself included, part of the joy of playing games on a PC is a smooth 60 FPS-or-higher frame rate, something that the Xbox One and PlayStation 4 have famously had a hard time hitting at just 1080p. While budget GPUs like Nvidia's GTX 750 Ti do an admirable job of 1080p60 in many games, even high-end cards like the GTX 980 can struggle with 4K at 60 FPS. For a solid 60 FPS, an SLI or Crossfire setup is the way to go. The folks over at Digital Foundry tested high-end single-card solutions with a range of games at high and ultra settings, with only the $1000 Titan X managing to push an average frame rate of over 60 FPS in some games. Note that's an average frame rate. As a proud owner of a Titan X and a 4K monitor, I've experienced drops down as low as 30 FPS during gameplay. Unfortunately, for fans of team red, AMD's high-end R9 290X is some way off even that level of performance, which is no surprise given the card is based off the company's rapidly ageing 2013 Hawaii architecture: only in Call Of Duty: Advanced Warfare does it manage to push over 60 FPS. Those wanting an AMD card for 4K would be advised to hold out for the company's long overdue architecture refresh, which is rumoured to be released later this year in the form of the R9 390 and 390X. The arrival of high-bandwidth memory (HBM) may possibly allow for single-GPU 4K gaming, but we'll have to wait until a new AMD graphics card arrives at the Ars Orbiting HQ for testing. Stepping up to a Crossfire or SLI setup will net you the required performance for 4K gaming, but there are some trade-offs aside from the higher cost. More GPUs means more heat to be funnelled out of your PC case, which can affect the performance of other components, particularly if you're using cards that vent air inside the case and you're not pushing enough air through the case to push the heat out. You'll also need to make sure your power supply can handle the increased power consumption of multiple GPUs, while also making sure your motherboard and processor supply enough PCIe lanes for the amount of cards you're using. This isn't really a concern for two or even three-way setups, but for those hell-bent on running four GPUs—despite the diminishing returns on performance—or M.2 SSDs, note that the latest Nvidia cards require at least an 8X slot in order to work in SLI. At around £500 (~$620), AMD's R9 295X2 (which combines two R9 290Xs onto a single card) is the cheapest dual-GPU option, and it works wonders in 4K for games that are Crossfire-optimized, although you'll have to make room for its 30.7cm length and 120mm watercooling radiator, as well as adhere to strict power supply requirements for its monster 500W TDP. A pair of GTX 970s will net you similar performance for around £530, and with only a 165W TDP per card. Just bear in mind that its famous VRAM issues do begin to have an effect when gaming at 4K—resulting in a larger frame-time variance and thus the dreaded microstutter—thanks to the far larger textures being loaded into memory. There are some steps you can take to increase performance, though. Turning down texture resolution and expensive effects like HBAO+ will naturally net you a few extra frames. If you're not keen on dropping the image quality, then switching off antialiasing is a good option. Not only is AA one of the most expensive post-processing effects you can use, it's also one of the least noticeable when gaming at 4K, thanks to the intrinsic effect of high pixel density smoothing out jaggies. If you can live with 30 FPS, then the likes of a single GTX 970 or higher paired with a decent quad-core CPU and fast SSD will do the trick. While you won't currently find a panel that runs above 60Hz (at least until they start to come equipped with DisplayPort 1.3 or higher), you can take your pick from a range of manufacturers and panel types. Generally, TN will give you the best grey-to-grey response times in exchange for poorer colour reproduction and viewing angles, while the opposite is true for IPS, which'll give you great colour reproduction and viewing angles but higher response times. Keep an eye on inputs too: until recently few 4K monitors came equipped with the HDMI 2.0 ports required for 60Hz. This isn't so much of an issue for the PC, where DisplayPort is king, but it's worth thinking about if you you'll want to add a 4K streaming box or similar down the line. Look out for 4K monitors that might actually be two 1920×2160 displays stitched together. This was common in the early days of 4K when the requisite scalers weren't available. While these monitors work well, because they make use of DisplayPort's Multi-Stream Transport (MST) standard, it cuts down on the number of monitors you can attach to your PC. They also don't behave well with games that fix menus and UI elements to a particular display, where they end up looking squished. Finally, there's variable refresh rate technology to consider. This matches the refresh rate of the display to the frame rate of your game, eliminating artefacts such as screen tearing when v-sync is turned off, and judder and input lag when it's turned on. Nvidia brands its tech as G-Sync, while AMD's is called FreeSync. Both have their positives and negatives, but on the whole, Nvidia's tech results in an overall smoother experience, thanks to the way it handles lower frame rates. Given how difficult it is to run 4K games at 60 FPS, variable refresh rate technology can provide excellent results, giving you much smoother gameplay when running above 30 FPS but below 60 FPS. At the moment, the only 4K monitors you can buy are G-Sync models, but Samsung is due to release a range of 4K monitors with FreeSync over the coming months.
News Article | August 26, 2015
It's no surprise that Samsung launches new Note devices at the end of every summer, but I honestly wasn't really considering buying one this year. With all of the new sub-$450 Android smartphones, likely new Nexus, iPhone 6S Plus, and flagship Lumia devices I figured I would save up my PayPal phone fund for one or more of those. While one of these other phones would satisfy me, regular readers know I tend to purchase the best smartphones and the Samsung Galaxy Note 5 is currently the top dog. Thus, I couldn't resist trying one for myself and the awesome T-Force team, lead by Chris, worked to get the phone into my hands quickly after the T-Mobile website failed to capture the shipping method I selected. As you can see, there is nothing missing from the Galaxy Note 5. Actually, Samsung leads with the fastest available RAM, fastest internal storage, new fast wireless charging technology, and magnetic secure transmission (MST) wireless payment technology. Combined with the other leading specifications, there is nothing else out there that beats the Samsung Galaxy Note 5. The Samsung Galaxy S6 Edge blew me away when I first opened up the retail box and that same feeling occurred when I opened up the Galaxy Note 5. Samsung was able to take its new design and improve it in the Note 5 with curved edges on the back, along with minimal side, top, and bottom bezels. The Galaxy Note 5 feels even more expensive than it is, clearly outclassing the new lower cost Android smartphones. The display is absolutely stunning and with the minimal bezels I can't stop staring at it. Fonts can be changed in style and size, but I do notice that some widgets appear with very small text that can't be changed. The front and back are Gorilla Glass with a metal, beveled edge frame around the entire phone. The front glass transitions nicely into the metal frame. There are four breaks in the frame, two each at the top and bottom, that help with the cellular signal. The 3.5mm headset jack, microUSB port, speaker, and S Pen silo are all found along the bottom. In order to remove the S Pen, you simply press down on the S Pen top and then pull it out. There are reports that people have been putting the S Pen in the silo with the telescoping end first. If you are writing normally on the display, there is no rational reason someone would have the wrong end pointed toward the device and S Pen, but I guess not even Samsung can design a product for everyone. Hardware home buttons help me improve my efficiency and the one on the Note 5 is perfect. The fingerprint scanner performs flawlessly, even better for me than the iPhone 6 Plus. I've been using the double press to launch the camera and am no longer ever missing a shot. Speaking of the camera, Samsung goes toe-to-toe with the LG G4 as two of the best smartphone cameras available today. The camera software is easy and powerful with full support for RAW in Pro mode. The flash next to the camera continues to serve as the heart rate monitor while the S Health software also helps you capture SpO2 and stress. Two key features missing from the new Galaxy Note 5 are the removable battery and microSD card. A third missing feature that may be important to a few is the infrared transmitter. I wrote about and lamented the loss of the removable battery and microSD card, but when I sat down and took a serious look at my own usage of smartphones over the past five years I found that these are not issues at all for me. Samsung made design trade-offs that resulted in these removals and I'm just fine with them. The Samsung Galaxy Note 5 runs the latest version of Android with TouchWiz. TouchWiz has been lightened up significantly while also providing users with the ability to customize their experiences. You will still find quick actions in the notification shade, but you can limit what appears there to just one row of icons and in any order you prefer. The app launcher screens can be organized however you like or you can just tap the A-Z icon to view your app shortcuts in alphabetical order. You can change up the home screen panel grid. It's also very easy to apply a theme to change up the entire look of your Note 5. There are a few Samsung, Microsoft, and T-Mobile apps installed out of the box, but the number of Google apps has been reduced and you can disable or hide many of these preloaded apps. A press and hold of the home button launches Google Now. You can also switch that up to Cortana if you desire. A double press launches the camera. The camera software is very functional with capture controls positioned over on the right edge and other quick settings on the left. You can tap into different modes, including selective focus, panorama, slow motion, YouTube live broadcast, and more. There is support for downloading and repositioning other modes too. An integrated photo editor is present while you can also now quickly and easily create collages right from the photo viewer. I discover something new just about every day and one thing I found on the Note 5 is that the contacts application now provides search results containing individual contact information for the associates of my engineering firm, through Exchange, without me even having those individuals in any contact list. With the Note 5 I am able to have an advanced business device. S Pen functionality has been enhanced with the ability to slide out the S Pen when the device display is off and write a note in white ink on a black display. With the display on, sliding out the S Pen pops out a new Air Command launcher with action memo, smart select, screen write, and S Note icons. There are also two available spots in the list for you to designate two other applications to launch with Air Command. The 64GB iPhone 6 Plus is $849 while the T-Mobile Samsung Galaxy Note 5 is $780 so I think there is some confusion about pricing when I read articles stating that the new Note 5 is more expensive than the Apple iPhone. The Galaxy Note 5 is $70 less than the comparable iPhone 6 Plus and offers more in terms of cutting edge technology. Thus, the price should not be a con for the Note 5 as it doesn't compare directly with the less-featured smartphones. There is no other competition when it comes to a true phablet that integrates the use of a stylus. Primary large screen flagship competitors include the Galaxy S6, LG G4, HTC One M9, and Apple iPhone 6 Plus. The Note 5 has more to offer than all of these. I loved the new design of the Galaxy S6 Edge, but the terrible battery life forced me to return it to T-Mobile. Thus, when I saw the Galaxy Note 5 announced with a similar design, awesome dark blue color, larger integrated battery, and S Pen functionality at an $80 lower selling price than the S6 Edge I immediately placed my order. I actually just sold my Apple iPhone 6 Plus with the intent to purchase the next iPhone, but the capabilities of the Note 5 have me questioning whether or not I will make that purchase. I've been using the Note 5 for a week, including during my daily train commute, while out and about with family and friends, while traveling across the country, and during very long days working and playing in New York City. So far, it has performed amazingly well with my only issue being that the battery still does not last as long as the iPhone 6 Plus I used for the last year. It gets me through a full, busy day, but just barely. I owned a couple of Notes over the years, but never fully embraced the S Pen. The cool new pop-out S Pen and functionality so far has me writing quite a few notes and using the S Pen more than I ever have in the past. I will continue to evaluate if the S Pen is an important element, but even if it turns out not to be so the T-Mobile Samsung Galaxy Note 5 is the best Samsung Galaxy phone yet released. I awarded the Galaxy Note 4 a 9/10 rating and followed that up with a review of the Galaxy Note Edge with a contributor's rating of 9.5/10. Last year's Notes impressed me with design improvements over previous Notes, but Samsung took the design even further this year with the Galaxy Note 5. As a result, I'm giving the Note 5 my highest Galaxy Note rating. Some may rant about the loss of microSD and a removable battery, but as I clearly detailed earlier these are not a concern to me and likely not a concern for the majority of smartphone buyers. The ability to more easily handle the Note 5, thanks to the reduction in width and curved glass back, and improved S Pen functionality make the Note 5 a device I plan to thoroughly integrate into my daily life.