Graphane Nanoribbons: A Theoretical Study

In this study, we investigate the electronic and magnetic properties of graphane nanoribbons. We find that zigzag and armchair graphane nanoribbons with H-passivated edges are nonmagnetic semiconductors. While bare armchair ribbons are also nonmagnetic, adjacent dangling bonds of bare zigzag ribbons have antiferromagnetic ordering at the same edge. Band gaps of the H-passivated zigzag and armchair nanoribbons exponentially depend on their width. Detailed analysis of adsorption of C, O, Si, Pt, Ti, V and Fe atoms on the graphane ribbon surface reveal that functionalization of graphane ribbons is possible via these adatoms. It is found that C, O, V and Pt atoms have tendency to replace H atoms of graphane. We showed that significant spin polarizations in graphane can be achieved through creation of domains of H-vacancies and CH-divacancies.Comment: Accepted for publication in Phys. Rev. B 81, xxxx (2010); http://link.aps.org/doi/10.1103/PhysRevB.81.20541

Magnetization of Graphane by Dehydrogenation

Each single hydrogen vacancy created at the surface of graphane gives rise to a local unpaired spin. For domains of hydrogen vacancies the situation is, however complex and depends on the size and geometry of domains, as well as whether the domains are single- or double-sided. In single-sided domains, hydrogen atoms at the other side are relocated to pair the spins of adjacent carbon atoms by forming pi-bonds. Owing to the different characters of exchange coupling in different ranges and interplay between unpaired spin and the binding geometry of hydrogen, vacancy domains can attain sizable net magnetic moments. Our results based on the first-principles calculations suggest that the size and ordering of magnetic moments of hydrogen vacancy domains with thin walls can be used for future data storage and spintronics applications.Comment: 4 pages, 3 figures (published in Applied Physics Letters

FABRIC: A Framework for the Design and Evaluation of Collaborative Robots with Extended Human Adaptation

A limitation for collaborative robots (cobots) is their lack of ability to adapt to human partners, who typically exhibit an immense diversity of behaviors. We present an autonomous framework as a cobot's real-time decision-making mechanism to anticipate a variety of human characteristics and behaviors, including human errors, toward a personalized collaboration. Our framework handles such behaviors in two levels: 1) short-term human behaviors are adapted through our novel Anticipatory Partially Observable Markov Decision Process (A-POMDP) models, covering a human's changing intent (motivation), availability, and capability; 2) long-term changing human characteristics are adapted by our novel Adaptive Bayesian Policy Selection (ABPS) mechanism that selects a short-term decision model, e.g., an A-POMDP, according to an estimate of a human's workplace characteristics, such as her expertise and collaboration preferences. To design and evaluate our framework over a diversity of human behaviors, we propose a pipeline where we first train and rigorously test the framework in simulation over novel human models. Then, we deploy and evaluate it on our novel physical experiment setup that induces cognitive load on humans to observe their dynamic behaviors, including their mistakes, and their changing characteristics such as their expertise. We conduct user studies and show that our framework effectively collaborates non-stop for hours and adapts to various changing human behaviors and characteristics in real-time. That increases the efficiency and naturalness of the collaboration with a higher perceived collaboration, positive teammate traits, and human trust. We believe that such an extended human adaptation is key to the long-term use of cobots.Comment: The article is in review for publication in International Journal of Robotics Researc

Impact of chromium histidinate on high fat diet induced obesity in rats

Background: Chromium (Cr) is an essential trace element that has garnered interest for use as a weight loss aid, but its molecular mechanism in obesity is not clear. In this study, an attempt has been made to investigate the effects of chromium histidinate (CrHis) on glucose transporter-2 (GLUT-2), nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), nuclear factor-kappa B (NF-kappa B p65) and the oxidative stress marker 4-hydroxynonenal adducts (HNE) expressions in liver of rats fed high fat diet (HFD). Methods: Male Wistar rats (n = 40, 8 wk-old) were divided into four groups. Group I was fed a standard diet (12% of calories as fat); Group II was fed a standard diet and supplemented with 110 mu g CrHis/kg BW/d; Group III was fed a HFD (40% of calories as fat); Group IV was fed HFD and supplemented with 110 mu g CrHis/kg BW/d. Results: Rats fed HFD possessed greater serum insulin (40 vs. 33 pmol/L) and glucose (158 vs. 143 mg/dL) concentration and less liver Cr (44 vs. 82 mu g/g) concentration than rats fed the control diet. However, rats supplemented with CrHis had greater liver Cr and serum insulin and lower glucose concentration in rats fed HFD (P < 0.05). The hepatic nuclear factor-kappa B (NF-kappa B p65) and HNE were increased in high fat group compared to control group, but reduced by the CrHis administration (P < 0.05). The levels of hepatic Nrf2 and HO-1 were increased by supplementation of CrHis (P < 0.05). Conclusion: These findings demonstrate that supplementation of CrHis is protective against obesity, at least in part, through Nrf2-mediated induction of HO-1 in rats fed high fat diet.Nutrition 21, Inc., NY, USAThe study was funded by Nutrition 21, Inc., NY, USA. Nutrition 21 also supplied the chromium histidinate used in the study. James Komorowskiis an employee of Nutrition 21, the distributors of chromium histidinateunder a license from the USDA

Does regular physical activity in children affect the quality of life?

Purpose: The purpose of this study was to investigate the effect of regular physical activity on quality of life. Procedure: The participants were 60 children (aged 8-12) composed of girls (n=15 age:10.67 ± 0.89 year; height:145.66 ± 5.40cm; weight:43.6 ± 5.51kg) and boys (n=15 age:10.66 ± 0.81 year; height:142. 2 ± 5.05cm; weight:42.73 ± 6.76kg) who were performing regular physical training, and girls (n=15 age:11 ± 0.81year; height:144.33 ± 3.04cm; weight:47.8 ± 4.47kg) and boys (n=15 age:10.66 ± 0.81year; height:142.2 ± 5.05cm; weight:42.73 ± 6.76kg) who were not performing regular physical training. Height - weight measurements and The Inventory of Turkish Children's Quality of Pediatric Life 4.0 (PedsQL 4.0) were implemented. All collected data's descriptive analysis and the difference between 2 groups were compared with test of significance of difference between two independent groups. Main findings: There was no statistically significant difference in quality of life of between the girls who were performing regular physical training and not (p>0.05). Boys' who were performing regular physical training quality of life in terms of physical health and social functions was higher than those who were not performing regular physical training (p<0.05). Girls who were performing regular physical training had lower quality of life with regard to physical status than boys (p<0.05). Conclusions: According to results of this study, it was determined that children especially boys who were performing regular physical activity had better quality of life in terms of physical health and social functions. © JPES

Does morbid obesity influence the success and complication rates of extracorporeal shockwave lithotripsy for upper ureteral stones?

WOS: 000360378600005PubMed ID: 26328193Objective: The aim of the current study was to investigate whether obesity influences the outcome of extracorporeal shockwave lithotripsy (ESWL) treatment for upper ureteral stones. Material and methods: This is a retrospective study of 134 patients who underwent ESWL between June 2011 and May 2014. Patients were divided into 2 groups. Group 1 comprised 94 patients of normal weight, and group 2 comprised 40 morbidly obese patients. Patients in both groups had upper ureteral stones. Results: The mean age of groups 1 and 2 was 45.6 +/- 12.1 and 45.3 +/- 15.5 years, respectively (p=0.98). There was no significant difference in demographic variables between the groups. The mean stone size in Groups 1 and 2 was 81.7 +/- 25.7 mm(2) and 86.3 +/- 22.4 mm(2), respectively (p=0.51), the mean body mass index (BMI) was 27.4 +/- 2.9 and 42.9 +/- 2.1, respectively (p<0.01), the mean number of ESWL sessions was 2.4 +/- 0.6 and 2.4 +/- 0.7, respectively (p=0.97), and the mean follow-up time was 7.1 +/- 3.4 and 6.6 +/- 2.8 weeks, respectively (p=0.67). The overall stone-free rate was 82% in group 1 and 67% in group 2 (p=0.01). Conclusion: It is well-known that morbidly obese patients have higher rates of anesthesia-related problems due to the comorbidities commonly observed in this population. In the current study, we found that ESWL is a safe and acceptable treatment option for morbidly obese patients with upper ureteral stones

Effects of artificial weathering on the surface properties of coated radiata pine

Radiata pine boards were coated with two different methods A and B both beginning with a hydro primer and finishing with a mat oil but method A using an acrylic high gloss coating and method B three layers of an acrylic sealer in between. The samples were subjected to aging processes for 144 h, 288 h, and 432 h by using UV-A 340 nm lamps. The CIE L*a*b* and CIE L*C*H* coordinates were determined (L*, a*, b*, C*, ho*, ΔE*), gloss (perpendicular (⊥) and parallel (//) to the grain at 20°, 60°, and 85° angles) and surface adhesion strength via the pull-off method were tested before and after weathering.&nbsp; Results have shown that lightness (L*), decreases with weathering for both varnish applications with a higher decrease for the B coating system. Redness increased for both applications with no significant differences. At the same time there was a yellowing of the samples along the weathering period. Parallel and perpendicular gloss decreased for 20º and 60º angles while it increased for 85º angle. The adhesion strength of method A was higher and its decrease with weathering was smaller than for method B. Both varnish applications have proven to confer some protection against wood discoloration, but method A showed the best results and is therefore the best method to be used by radiata pine

Enhanced Second Harmonic Generation from Coupled Asymmetric Plasmonic Metal Nanostructures

We show that second harmonic generation can be enhanced by Fano resonant coupling of asymmetric plasmonic metal nanostructures. We develop a theoretical model examining the effects of electromagnetic interaction between two metal nanostructures on the second harmonic generation. We compare the second harmonic generation efficiency of a single plasmonic metal nanostructure with that of two coupled ones. We show that second harmonic generation from a single metal nanostructure can be enhanced about 30 times by attaching a second metal nanostructure with a 10 times higher quality factor than that of the first one. The origin of this enhancement is Fano resonant coupling of the two metal nanostructures. We support our findings on Fano enhancement of second harmonic generation by an experimental study of a coupled plasmonic system composed of a silver nanoparticle and a silver nanowire on glass surface in which the ratio of the quality factors are also estimated to be around 10 times