bluuebunny/crossref_metadata_2025 huggingface dataset:
Conservation and divergence within the clathrin interactome of Trypanosoma cruzi
Authors: Kalb Ligia Cristina , Frederico Yohana Camila A. , Boehm Cordula , Moreira Claudia Maria do Nascimento , Soares Maurilio José , Field Mark C.
Published: August 2016

Trypanosomatids are parasitic protozoa with a significant burden on human health. African and American trypanosomes are causative agents of Nagana and Chagas disease respectively, and speciated about 300 million years ago. These parasites have highly distinct life cycles, pathologies, transmission strategies and surface proteomes, being dominated by the variant surface glycoprotein (African) or mucins (American) respectively. In African trypanosomes clathrin-mediated trafficking is responsible for endocytosis and post-Golgi transport, with several mechanistic aspects distinct from higher organisms. Using clathrin light chain (TcCLC) and EpsinR (TcEpsinR) as affinity handles, we identified candidate clathrin-associated proteins (CAPs) in Trypanosoma cruzi; the cohort includes orthologs of many proteins known to mediate vesicle trafficking, but significantly not the AP-2 adaptor complex. Several trypanosome-specific proteins common with African trypanosomes, were also identified. Fluorescence microscopy revealed localisations for TcEpsinR, TcCLC and TcCHC at the posterior region of trypomastigote cells, coincident with the flagellar pocket and Golgi apparatus. These data provide the first systematic analysis of clathrin-mediated trafficking in T. cruzi, allowing comparison between protein cohorts and other trypanosomes and also suggest that clathrin trafficking in at least some life stages of T. cruzi may be AP-2-independent.
Effect of assisted hatching on pregnancy outcomes: a systematic review and meta-analysis of randomized controlled trials
Authors: Li Da , Yang Da-Lei , An Jing , Jiao Jiao , Zhou Yi-Ming , Wu Qi-Jun , Wang Xiu-Xia
Published: August 2016

Emerging evidence suggests that assisted hatching (AH) techniques may improve clinical pregnancy rates, particularly in poor prognosis patients; however, there still remains considerable uncertainty. We conducted a meta-analysis to verify the effect of AH on pregnancy outcomes. We searched for related studies published in PubMed, Web of Science and Cochrane library databases from start dates to October 10, 2015. Totally, 36 randomized controlled trials with 6459 participants were included. Summary odds ratios (ORs) with 95% confidence intervals (CIs) for whether by AH or not were estimated. We found a significant increase in clinical pregnancy (OR = 1.16, 95% CI = 1.00–1.36, I2 = 48.3%) and multiple pregnancy rates (OR = 1.50, 95% CI = 1.11–2.01, I2 = 44.0%) with AH when compared to the control. Numerous subgroup analyses stratified by hatching method, conception mode, extent of AH, embryos transfer status and previous failure history were also carried out. Interestingly, significant results of clinical pregnancy as well as multiple pregnancy rates were observed among women who received intracytoplasmic sperm injection and who received AH which the zona were completely removed. In summary, this meta-analysis supports that AH was associated with an increased chance of achieving clinical pregnancy and multiple pregnancy. Whether AH significantly changes live birth and miscarriage rates needs further investigations.
Neuroanatomical bases of effortful control: evidence from a large sample of young healthy adults using voxel-based morphometry
Authors: Nouchi Rui , Takeuchi Hikaru , Taki Yasuyuki , Sekiguchi Atsushi , Kotozaki Yuka , Nakagawa Seishu , Miyauchi Carlos Makoto , Iizuka Kunio , Yokoyama Ryoichi , Shinada Takamitsu , Yamamoto Yuki , Hanawa Sugiko , Araki Tsuyoshi , Sassa Yuko , Kawashima Ryuta
Published: August 2016

Effortful control (EC) is a base of individuality in cognition and psychological adjustment. EC is defined as a capacity to control responses and behaviors. We investigated associations between individual differences of EC and regional gray and white matter volume (rGMV/rGMV) in 374 men and 306 women (age, 20.61 ± 1.82 years) using Japanese version of Effortful control scale (J-ECS). J-ECS consists of three subscales such as inhibitory control (IC), activation control (ACTC), and attentional control (ATC). Results showed that (a) IC was associated with larger rGMV in the dorsal part of anterior cingulate cortex (dACC), the supplementary motor area (SMA) and the pre SMA and larger rWMV in the dACC, (b) ACTC was correlated with smaller rGMV in the insula and the putamen, and (c) ATC was associated with larger rWMV in the inferior frontal gyrus, orbital frontal gyrus, ACC, and insula. Our study revealed key neuroanatomical correlations between EC and rGMV and rWMV.
Evaluation of VDR gene polymorphisms in Trypanosoma cruzi infection and chronic Chagasic cardiomyopathy
Authors: Leon Rodriguez Daniel A , Carmona F David , González Clara Isabel , Martin Javier
Published: August 2016

Vitamin D is an important modulator of the immune response. It acts over several immune cell types where the Vitamin D receptor (VDR) is expressed. Due to the high relevance of this signaling pathway, several studies have investigated the possible influence of genes involved in the metabolism of Vitamin D and its receptor in different human diseases. Here, we analyzed whether four single-nucleotide polymorphisms of the VDR gene (rs731236, rs7975232, rs1544410 and rs2228570) are involved in the susceptibility to infection by Trypanosoma cruzi and/or to chronic Chagas cardiomyopathy (CCC) in a Colombian endemic population for this parasite. Our results showed that the rs2228570*A allele is associated with CCC development (P = 4.46E−03, OR = 1.51). In summary, the data presented in this report suggest that variation within the VDR gene may affect the immune response against T. cruzi, increasing the probability of cardiac complications in infected individuals.
Deformable Self-Propelled Micro-Object Comprising Underwater Oil Droplets
Authors: Banno Taisuke , Asami Arisa , Ueno Naoko , Kitahata Hiroyuki , Koyano Yuki , Asakura Kouichi , Toyota Taro
Published: August 2016

The self-propelled motion with deformation of micrometer-sized soft matter in water has potential application not only for underwater carriers or probes in very narrow spaces but also for understanding cell locomotion in terms of non-equilibrium physics. As far as we know, there have been no reports about micrometer-sized self-propelled soft matter mimicking amoeboid motion underwater. Here, we report an artificial molecular system of underwater oil droplets exhibiting self-propelled motion with deformation as an initial experimental model. We describe the heterogeneity in a deformable self-propelled oil droplet system in aqueous and oil phases and at their interface based on the behavior and interaction of surfactant and oil molecules. The current results have great importance for scientific frontiers such as developing deformable micro-swimmers and exploring the emergence of self-locomotion of oil droplet-type protocells.
Reciprocity in spatial evolutionary public goods game on double-layered network
Authors: Kim Jinho , Yook Soon-Hyung , Kim Yup
Published: August 2016

Spatial evolutionary games have mainly been studied on a single, isolated network. However, in real world systems, many interaction topologies are not isolated but many different types of networks are inter-connected to each other. In this study, we investigate the spatial evolutionary public goods game (SEPGG) on double-layered random networks (DRN). Based on the mean-field type arguments and numerical simulations, we find that SEPGG on DRN shows very rich interesting phenomena, especially, depending on the size of each layer, intra-connectivity, and inter-connected couplings, the network reciprocity of SEPGG on DRN can be drastically enhanced through the inter-connected coupling. Furthermore, SEPGG on DRN can provide a more general framework which includes the evolutionary dynamics on multiplex networks and inter-connected networks at the same time.
Oxalate-mediated long-range antiferromagnetism order in Fe2(C2O4)3·4H2O
Authors: Rousse G. , Rodríguez-Carvajal J.
Published: August 2016

Neutron powder diffraction and susceptibility measurements reveal the long range antiferromagnetic order mediated by oxalate molecules in Fe2(C2O4)3·4H2O.
Lithium-excess olivine electrode for lithium rechargeable batteries
Authors: Park Kyu-Young , Park Inchul , Kim Hyungsub , Yoon Gabin , Gwon Hyeokjo , Cho Yongbeom , Yun Young Soo , Kim Jung-Joon , Lee Seongsu , Ahn Docheon , Kim Yunok , Kim Haegyeom , Hwang Insang , Yoon Won-Sub , Kang Kisuk
Published: August 2016

This article introduces a new type of ‘lithium-excess Li1+xFe1−xPO4’ cathode material for lithium rechargeable batteries.
Regioselective and stereoselective sulfonylation of alkynylcarbonyl compounds in water
Authors: Li Wenyi , Yin Guoxing , Huang Lei , Xiao Yan , Fu Zhimin , Xin Xiu , Liu Fang , Li Zhizhang , He Weimin
Published: August 2016

A simple and efficient route for the synthesis of Z-β-sulfonyl-α,β-unsaturated carbonyl compounds by using water as the solvent and hydrogen source is developed.
CO2-Catalysed aldol condensation of 5-hydroxymethylfurfural and acetone to a jet fuel precursor
Authors: Lee Roland , Vanderveen Jesse R. , Champagne Pascale , Jessop Philip G.
Published: August 2016

CO2 can act as a catalyst for the production of bio-jet fuel precursors through aldol condensation.
Supramolecular ensemble of PBI derivative and copper nanoparticles: a light harvesting antenna for photocatalytic C(sp2)–H functionalization
Authors: Kaur Sandeep , Kumar Manoj , Bhalla Vandana
Published: August 2016

A supramolecular ensemble of triazole-appended perylene bisimide (PBI) derivative 4 and in situ generated copper nanoparticles (CuNPs) serves as a light-harvesting antenna in photocatalytic C(sp2)–H alkynylation and amination reactions of arenes under mild and eco-friendly conditions.
A lab-on-a-disc with reversible and thermally stable diaphragm valves
Authors: Kim Tae-Hyeong , Sunkara Vijaya , Park Juhee , Kim Chi-Ju , Woo Hyun-Kyung , Cho Yoon-Kyoung
Published: August 2016

This paper reports a robust, reversible and thermally stable valving technique on a lab-on-a-disc.
Energy generation from water flow over a reduced graphene oxide surface in a paper–pencil device
Authors: Arun Ravi Kumar , Singh Preeti , Biswas Gautam , Chanda Nripen , Chakraborty Suman
Published: August 2016

We report an ultra-low-cost device for energy conversion by exploiting the capillary flow of an electrolyte on a filter paper matrix in which a naturally deposited gradient of reduced graphene oxide is induced through chemical synthesis.
Enantioselective synthesis of spiro[indoline-3,4′-pyrano[2,3-c]pyrazole] derivatives via an organocatalytic asymmetric Michael/cyclization cascade reaction
Authors: Xie Jin , Xing Xiao-Yu , Sha Feng , Wu Zhi-Yan , Wu Xin-Yan
Published: August 2016

Pyrazolones have been firstly employed to react with isatylidene malononitriles, and chiral multicyclic spirooxindoles have been constructed with a low loading of commercially available catalysts.
Photo-cleavable nucleotides for primer free enzyme mediated DNA synthesis
Authors: Mathews Anu Stella , Yang Haikang , Montemagno Carlo
Published: August 2016

The synthesis and characterization of eight 3′-Omodified 2′-deoxyribonucleoside triphosphates for template-less enzyme mediated photo-triggered “stop–start” DNA synthesis is presented.
Mycobacterial carbonic anhydrase inhibition with phenolic acids and esters: kinetic and computational investigations
Authors: Cau Ylenia , Mori Mattia , Supuran Claudiu T. , Botta Maurizio
Published: August 2016

Phenolic acids and their ester derivatives show specific inhibition of beta-carbonic anhydrases fromMycobacterium tuberculosis, and are interesting anti-mycobacterial leads.
Efficient click-addition sequence for polymer–polymer couplings
Authors: Brendel Johannes C. , Gody Guillaume , Perrier Sébastien
Published: August 2016

Controlled radical polymerization methods and click chemistry form a versatile toolbox for creating complex polymer architectures.
Probing the causes of thermal hysteresis using tunable Nagg micelles with linear and brush-like thermoresponsive coronas
Authors: Blackman L. D. , Gibson M. I. , O'Reilly R. K.
Published: August 2016

Self-assembled thermoresponsive polymers in aqueous solution have great potential as smart, switchable materials for use in biomedical applications.
Is biopolymer hair a multi-responsive smart material?
Authors: Xiao Xueliang , Hu Jinlian , Gui Xiaoting , Lu Jing , Luo Hongsheng
Published: August 2016

A twin-netpoint-switch structure model for animal hair has been proposed for interpreting different shape memory abilities when exposure on different external stimuli, where a twin-netpoint/single-switch structure is for the stimulus of water, heat and UV-light, and a single-netpoint/twin-switch structure is for the stimulus of redox agent.
Development of a novel curing system for low temperature curing of resins with the aid of nanotechnology and ultraviolet radiation
Authors: Ashraf Munir , Irshad Farida , Umar Jawairia , Farooq Assad , Ashraf Mohammad Azeem
Published: August 2016

In this research work, low temperature curing of crease recovery finishes was done with the help of ZnO nanoparticles as catalyst in the presence of UV radiation. The results were compared with the conventional catalyst and thermal curing system.
A hydroxyl-functionalized microporous organic polymer for capture and catalytic conversion of CO2
Authors: Zhang Xiao , Lv Yan-Zong , Liu Xiao-Liang , Du Guo-Jing , Yan Shi-Hao , Liu Jian , Zhao Zhen
Published: August 2016

A novel hydroxyl-functionalized microporous organic polymer (HF-MOP) exhibited good CO2capture performance and excellent catalytic activity in cycloaddition reaction.
Facile synthesis of an Al-doped carbon-coated Li4Ti5O12 anode for high-rate lithium-ion batteries
Authors: Yin Pei-Sin , Peng Hao-Ting , Xiao Yaoming , Lin Tsung-Wu , Lin Jeng-Yu
Published: August 2016

Sol–gel synthesized LTAO/C composites demonstrated capacity retention of 97.9% at 20C after 100 cycles.
Phase-transfer catalyzed enantioselective α-alkylation of α-acyloxymalonates: construction of chiral α-hydroxy quaternary stereogenic centers
Authors: Ha Min Woo , Choi Sujee , Kim Seek , Lee Jun Young , Lee Jae Kyun , Lee Jeeyeon , Hong Suckchang , Park Hyeung-geun
Published: August 2016

The enantioselective synthesis of α-acyloxy-α-alkylmalonates was developed as an efficient method for producing chiral α-tertiary alcohols, which are potentially valuable intermediates in the synthesis of natural products and pharmaceuticals.
Direct visualization of solid electrolyte interphase on Li4Ti5O12 by in situ AFM
Authors: Wang Shuwei , Yang Kai , Gao Fei , Wang Deyu , Shen Cai
Published: August 2016

Whether Li4Ti5O12 has a solid electrolyte interphase (SEI) layer on the electrode surface has been the subject of controversy for a long time due to the delicate nature of this SEI layer and the lack of reliable characterization tools.
Nanoscale iron carboxylate metal organic frameworks as drug carriers for magnetically aided intracellular delivery
Authors: Sethi Komal , Sharma Shalini , Roy Indrajit
Published: August 2016

We report the synthesis, characterisation, and magnetically controlled drug delivery applications of drug-encapsulated iron carboxylate nanoscale metal organic frameworks (NMOFs).
Understanding structural characteristics of out-of-register hIAPP amyloid proteins via molecular dynamics
Authors: Baek Inchul , Lee Myeongsang , Na Sungsoo
Published: August 2016

We investigated characteristics of out-of-register (OOR) hIAPP amyloids. By varying the length size of OOR hIAPP, we found 8 layers is most stable. In addition, OOR hIAPP has relative structural instability than in-register hAIPP.
Templated dewetting: designing entirely self-organized platforms for photocatalysis
Authors: Altomare Marco , Nguyen Nhat Truong , Schmuki Patrik
Published: August 2016

Noble metal dewetting on self-organized TiO2 nanotubes – nanoscopic design of photocatalysts towards green H2 generation.
Effects of interfacial layers on the photoelectrochemical properties of tantalum nitride photoanodes for solar water splitting
Authors: Wang Chizhong , Hisatomi Takashi , Minegishi Tsutomu , Nakabayashi Mamiko , Shibata Naoya , Katayama Masao , Domen Kazunari
Published: August 2016

A Ta3N5photoanode incorporating a Nb4N5interlayer exhibits an oriented Ta3N5grain layer and an enhanced photocurrent for water splitting.
New biocompatible hydroxy double salts and their drug delivery properties
Authors: Kaassis Abdessamad Y. A. , Wei Min , Williams Gareth R.
Published: August 2016

Two novel biocompatible hydroxy double salts (HDSs) have been synthesised, loaded with the drug naproxen, and formulated into tablets.
New anisopleural spindle-like nonlinear optic (NLO) chromophores with a D–D′–π–A′–A or D–A′–π–D′–A structure: interesting optical behavior and DFT calculation results
Authors: Li Chuangyang , Li Ming , Li Yao , Shi Zuosen , Li Zong-Jun , Wang Xibin , Sun Jian , Sun Jingwen , Zhang Daming , Cui Zhanchen
Published: August 2016

S-Chromophores showed larger DFT calculation μβ and red-shifted λmax which indicated more effective intermolecular charge transfer.
CaAlSiN3:Eu2+ translucent ceramic: a promising robust and efficient red color converter for solid state laser displays and lighting
Authors: Li Shuxing , Zhu Qiangqiang , Wang Le , Tang Daiming , Cho Yujin , Liu Xuejian , Hirosaki Naoto , Nishimura Toshiyuki , Sekiguchi Takashi , Huang Zhengren , Xie Rong-Jun
Published: August 2016

Translucent CaAlSiN3:Eu2+ ceramic with a unique microstructure shows enhanced thermal stability and high quantum efficiency.
Energy balance, body composition, sedentariness and appetite regulation: pathways to obesity
Authors: Hopkins Mark , Blundell John E.
Published: August 2016

Energy balance is not a simple algebraic sum of energy expenditure and energy intake as often depicted in communications. Energy balance is a dynamic process and there exist reciprocal effects between food intake and energy expenditure. An important distinction is that of metabolic and behavioural components of energy expenditure. These components not only contribute to the energy budget directly, but also by influencing the energy intake side of the equation. It has recently been demonstrated that resting metabolic rate (RMR) is a potential driver of energy intake, and evidence is accumulating on the influence of physical activity (behavioural energy expenditure) on mechanisms of satiety and appetite control. These effects are associated with changes in leptin and insulin sensitivity, and in the plasma levels of gastrointestinal (GI) peptides such as glucagon-like peptide-1 (GLP-1), ghrelin and cholecystokinin (CCK). The influence of fat-free mass on energy expenditure and as a driver of energy intake directs attention to molecules emanating from skeletal tissue as potential appetite signals. Sedentariness (physical inactivity) is positively associated with adiposity and is proposed to be a source of overconsumption and appetite dysregulation. The molecular signals underlying these effects are not known but represent a target for research.
Epigenetic control of exercise training-induced cardiac hypertrophy by miR-208
Authors: Soci Ursula Paula Renó , Fernandes Tiago , Barauna Valerio Garrone , Hashimoto Nara Yumi , de Fátima Alves Mota Gloria , Rosa Kaleizu Teodoro , Irigoyen Maria Claudia , Philips Michael Ian , de Oliveira Edilamar Menezes
Published: August 2016

Aerobic exercise-induced cardiac hypertrophy (CH) is a physiological response involving accurate orchestration of gene and protein expression of contractile and metabolic components. The microRNAs: miR-208a, miR-208b and miR-499 are each encoded by a myosin gene and thus are also known as ‘MyomiRs’, regulating several mRNA targets that in turn regulate CH and metabolic pathways. To understand the role of myomiRs in the fine-tuning of cardiac myosin heavy chain (MHC) isoform expression by exercise training-induced physiological hypertrophy, Wistar rats were subjected to two different swim training protocols. We observed that high-volume swim training (T2), improved cardiac diastolic function, induced CH and decreased the expression of miR-208a and miR-208b. Consequently, the increased expression of their targets, sex determining region y-related transcription factor 6 (Sox6), Med13, Purβ, specificity proteins (Sp)/Krüppel-like transcription factor 3 (SP3) and HP1β (heterochromatin protein 1β) was more prominent in T2, thus converging to modulate cardiac metabolic and contractile adaptation by exercise training, with an improvement in the α-MHC/β-MHC ratio, bypassing the increase in PPARβ and histone deacetylase (HDAC) class I and II regulation. Altogether, we conclude that high-volume swim training finely assures physiological cardiac remodelling by epigenetic regulation of myomiRs, because inhibition of miR-208a and miR-208b increases the expression of their target proteins and stimulates the interaction among metabolic, contractile and epigenetic genes.
Administration of tauroursodeoxycholic acid prevents endothelial dysfunction caused by an oral glucose load
Authors: Walsh Lauren K. , Restaino Robert M. , Neuringer Martha , Manrique Camila , Padilla Jaume
Published: August 2016

Postprandial hyperglycaemia leads to a transient impairment in endothelial function; however, the mechanisms remain largely unknown. Previous work in cell culture models demonstrate that high glucose results in endoplasmic reticulum (ER) stress and, in animal studies, ER stress has been implicated as a cause of endothelial dysfunction. In the present study, we tested the hypothesis that acute oral administration of tauroursodeoxycholic acid (TUDCA, 1500 mg), a chemical chaperone known to alleviate ER stress, would prevent hyperglycaemia-induced endothelial dysfunction. In 12 young healthy subjects (seven men, five women), brachial artery flow-mediated dilation (FMD) was assessed at baseline, and at 60 and 120 min after an oral glucose challenge. Subjects were tested on two separate visits in a single-blind randomized cross-over design: after oral ingestion of TUDCA or placebo capsules. FMD was reduced from baseline during hyperglycaemia under the placebo condition (−32% at 60 min and −28% at 120 min post oral glucose load; P<0.05 from baseline) but not under the TUDCA condition (−4% at 60 min and +0.3% at 120 min post oral glucose load; P>0.05 from baseline). Postprandial plasma glucose and insulin were not altered by TUDCA ingestion. Plasma oxidative stress markers 3-nitrotyrosine and thiobarbituric acid reactive substance (TBARS) remained unaltered throughout the oral glucose challenge in both conditions. These results suggest that hyperglycaemia-induced endothelial dysfunction can be mitigated by oral administration of TUDCA, thus supporting the hypothesis that ER stress may contribute to endothelial dysfunction during postprandial hyperglycaemia.
Passive switched‐capacitor filter with complex poles for high‐speed applications
Authors: Payandehnia P. , Maghami H. , Kareppagoudr M. , Temes G.C.
Published: August 2016

A novel complex‐pole switched‐capacitor lowpass filter topology is presented. The proposed scheme features sharper roll‐off in the frequency response and reduced in‐band loss compared with a real‐pole filter. It provides higher stop‐band rejection for the same bandwidth. Hence, the required filter order and chip area are reduced. These improvements are achieved without adding more active blocks to the real‐pole filter, and with minimal added complexity. The proposed filter has the same low‐output thermal noise level as the real‐pole filter. These features, combined with a wide‐frequency tuning range, make the filter suitable for high‐speed, low‐noise, and low‐power applications. A fourth‐order 200 MS/s filter prototype was designed in 0.18 µm Asahi Kasei Microdevices Corporation CMOS technology. Simulations verify that the average in‐band loss is reduced by 3.2 dB compared with the real‐pole filter. The 3 dB cut‐off frequency can be tuned from 470 kHz to 17.5 MHz with 100 dB maximum stop‐band rejection.
Delayed quadratic buck converter
Authors: Vázquez Nimrod , Reyes‐Malanche Josue Augusto , Vázquez Eslí , Osorio Rene , Hernández Claudia
Published: August 2016

Nowadays, the microprocessors family normally require for the input source not only low voltage but also high current. There exists an increasing necessity for developing new applied techniques on topologies and control strategies, which may be able to fulfil such requirements. Although a considerable amount of applications use the conventional buck converter for step‐down for DC/DC conversion, when a high step‐down conversion is required is a much better choice to implement the quadratic buck converter (QBC); however, the problem for obtaining a high step‐down conversion at wide duty ratio still remains. This document proposes the delayed quadratic buck converter, which offers a very high‐step‐down dc–dc conversion with a wide duty cycle. The QBC is modified in its topology by adding an inductor, which allows us to obtain for the duty cycle a higher increment than this normally obtained by a quadratic one. Converter behaviour and analysis are illustrated. Experimental results are also shown for a conversion from 36 to 1.5 V and an output power of 20 W.
Permanent partial shading detection for protection of photovoltaic panels against hot spotting
Authors: Ghanbari Teymoor
Published: August 2016

Hot spot of photovoltaic (PV) panels leads to early degradation and even permanent damage of them. Partial shading is the main cause of hot spotting. Conventional bypass diodes are not able to rectify hot spotting perfectly and more efficient techniques are necessary. In this study, a simple technique is proposed for detection of partial shading and protection of the panels against hot spotting. Moreover, a strategy is used for discrimination between permanent and temporary partial shadings. Equivalent DC impedance of the panel is utilised to detect partial shading. Then, the shaded panel is open circuited using a simple relay to prevent hot spotting. The detection is confirmed or declined by measuring Thevenin impedance of the panel in a reclosing strategy. In the reclosing strategy, the panel is reconnected to the PV system for temporary partial shadings or disconnected from the system for permanent partial shading. The Thevenin impedance is calculated using open circuit voltage and short circuit current of the panel measured by a current sensor and a simple resistive voltage divider. The performance of the proposed method is evaluated using some experiments. The results confirm the performance of the technique for prevention of hot spotting.
Tunable VO2/Au hyperbolic metamaterial
Authors: Prayakarao S. , Mendoza B. , Devine A. , Kyaw C. , van Dover R. B. , Liberman V. , Noginov M. A.
Published: August 2016

Vanadium dioxide (VO2) is known to have a semiconductor-to-metal phase transition at ∼68 °C. Therefore, it can be used as a tunable component of an active metamaterial. The lamellar metamaterial studied in this work is composed of subwavelength VO2 and Au layers and is designed to undergo a temperature controlled transition from the optical hyperbolic phase to the metallic phase. VO2 films and VO2/Au lamellar metamaterial stacks have been fabricated and studied in electrical conductivity and optical (transmission and reflection) experiments. The observed temperature-dependent changes in the reflection and transmission spectra of the metamaterials and VO2 thin films are in a good qualitative agreement with theoretical predictions. The demonstrated optical hyperbolic-to-metallic phase transition is a unique physical phenomenon with the potential to enable advanced control of light-matter interactions.
Aluminum-catalyzed silicon nanowires: Growth methods, properties, and applications
Authors: Hainey Mel F. , Redwing Joan M.
Published: August 2016

Metal-mediated vapor-liquid-solid (VLS) growth is a promising approach for the fabrication of silicon nanowires, although residual metal incorporation into the nanowires during growth can adversely impact electronic properties particularly when metals such as gold and copper are utilized. Aluminum, which acts as a shallow acceptor in silicon, is therefore of significant interest for the growth of p-type silicon nanowires but has presented challenges due to its propensity for oxidation. This paper summarizes the key aspects of aluminum-catalyzed nanowire growth along with wire properties and device results. In the first section, aluminum-catalyzed nanowire growth is discussed with a specific emphasis on methods to mitigate aluminum oxide formation. Next, the influence of growth parameters such as growth temperature, precursor partial pressure, and hydrogen partial pressure on nanowire morphology is discussed, followed by a brief review of the growth of templated and patterned arrays of nanowires. Aluminum incorporation into the nanowires is then discussed in detail, including measurements of the aluminum concentration within wires using atom probe tomography and assessment of electrical properties by four point resistance measurements. Finally, the use of aluminum-catalyzed VLS growth for device fabrication is reviewed including results on single-wire radial p-n junction solar cells and planar solar cells fabricated with nanowire/nanopyramid texturing.
High-resolution measurements of the DT neutron spectrum using new CD foils in the Magnetic Recoil neutron Spectrometer (MRS) on the National Ignition Facility
Authors: Gatu Johnson M. , Frenje J. A. , Bionta R. M. , Casey D. T. , Eckart M. J. , Farrell M. P. , Grim G. P. , Hartouni E. P. , Hatarik R. , Hoppe M. , Kilkenny J. D. , Li C. K. , Petrasso R. D. , Reynolds H. G. , Sayre D. B. , Schoff M. E. , Séguin F. H. , Skulina K. , Yeamans C. B.
Published: August 2016

The Magnetic Recoil neutron Spectrometer (MRS) on the National Ignition Facility measures the DT neutron spectrum from cryogenically layered inertial confinement fusion implosions. Yield, areal density, apparent ion temperature, and directional fluid flow are inferred from the MRS data. This paper describes recent advances in MRS measurements of the primary peak using new, thinner, reduced-area deuterated plastic (CD) conversion foils. The new foils allow operation of MRS at yields 2 orders of magnitude higher than previously possible, at a resolution down to ∼200 keV FWHM.
Warhead verification as inverse problem: Applications of neutron spectrum unfolding from organic-scintillator measurements
Authors: Lawrence Chris C. , Febbraro Michael , Flaska Marek , Pozzi Sara A. , Becchetti F. D.
Published: August 2016

Verification of future warhead-dismantlement treaties will require detection of certain warhead attributes without the disclosure of sensitive design information, and this presents an unusual measurement challenge. Neutron spectroscopy—commonly eschewed as an ill-posed inverse problem—may hold special advantages for warhead verification by virtue of its insensitivity to certain neutron-source parameters like plutonium isotopics. In this article, we investigate the usefulness of unfolded neutron spectra obtained from organic-scintillator data for verifying a particular treaty-relevant warhead attribute: the presence of high-explosive and neutron-reflecting materials. Toward this end, several improvements on current unfolding capabilities are demonstrated: deuterated detectors are shown to have superior response-matrix condition to that of standard hydrogen-base scintintillators; a novel data-discretization scheme is proposed which removes important detector nonlinearities; and a technique is described for re-parameterizing the unfolding problem in order to constrain the parameter space of solutions sought, sidestepping the inverse problem altogether. These improvements are demonstrated with trial measurements and verified using accelerator-based time-of-flight calculation of reference spectra. Then, a demonstration is presented in which the elemental compositions of low-Z neutron-attenuating materials are estimated to within 10%. These techniques could have direct application in verifying the presence of high-explosive materials in a neutron-emitting test item, as well as other for treaty verification challenges.
Design and first plasma measurements of the ITER-ECE prototype radiometer
Authors: Austin M. E. , Brookman M. W. , Rowan W. L. , Danani S. , Bryerton E. W. , Dougherty P.
Published: August 2016

On ITER, second harmonic optically thick electron cyclotron emission (ECE) in the range of 220-340 GHz will supply the electron temperature (Te). To investigate the requirements and capabilities prescribed for the ITER system, a prototype radiometer covering this frequency range has been developed by Virginia Diodes, Inc. The first plasma measurements with this instrument have been carried out on the DIII-D tokamak, with lab bench tests and measurements of third through fifth harmonic ECE from high Te plasmas. At DIII-D the instrument shares the transmission line of the Michelson interferometer and can simultaneously acquire data. Comparison of the ECE radiation temperature from the absolutely calibrated Michelson and the prototype receiver shows that the ITER radiometer provides accurate measurements of the millimeter radiation across the instrument band.
Charge carrier dynamics and surface plasmon interaction in gold nanorod-blended organic solar cell
Authors: Rana Aniket , Gupta Neeraj , Lochan Abhiram , Sharma G. D. , Chand Suresh , Kumar Mahesh , Singh Rajiv K.
Published: August 2016

The inclusion of plasmonic nanoparticles into organic solar cell enhances the light harvesting properties that lead to higher power conversion efficiency without altering the device configuration. This work defines the consequences of the nanoparticle overloading amount and energy transfer process between gold nanorod and polymer (active matrix) in organic solar cells. We have studied the hole population decay dynamics coupled with gold nanorods loading amount which provides better understanding about device performance limiting factors. The exciton and plasmon together act as an interacting dipole; however, the energy exchange between these two has been elucidated via plasmon resonance energy transfer (PRET) mechanism. Further, the charge species have been identified specifically with respect to their energy levels appearing in ultrafast time domain. The specific interaction of these charge species with respective surface plasmon resonance mode, i.e., exciton to transverse mode of oscillation and polaron pair to longitudinal mode of oscillations, has been explained. Thus, our analysis reveals that PRET enhances the carrier population density in polymer via non-radiative process beyond the concurrence of a particular plasmon resonance oscillation mode and polymer absorption range. These findings give new insight and reveal specifically the factors that enhance and control the performance of gold nanorods blended organic solar cells. This work would lead in the emergence of future plasmon based efficient organic electronic devices.
Particle-in-cell study of the ion-to-electron sheath transition
Authors: Scheiner Brett , Baalrud Scott D. , Hopkins Matthew M. , Yee Benjamin T. , Barnat Edward V.
Published: August 2016

The form of a sheath near a small electrode, with bias changing from below to above the plasma potential, is studied using 2D particle-in-cell simulations. When the electrode is biased within Te/2e below the plasma potential, the electron velocity distribution functions (EVDFs) exhibit a loss-cone type truncation due to fast electrons overcoming the small potential difference between the electrode and plasma. No sheath is present in this regime, and the plasma remains quasineutral up to the electrode. The EVDF truncation leads to a presheath-like density and flow velocity gradients. Once the bias exceeds the plasma potential, an electron sheath is present. In this case, the truncation driven behavior persists, but is accompanied by a shift in the maximum value of the EVDF that is not present in the negative bias cases. The flow moment has significant contributions from both the flow shift of the EVDF maximum, and the loss-cone truncation.
Case of study: Photovoltaic faults recognition method based on data mining techniques
Authors: Serrano-Luján Lucia , Cadenas Jose Manuel , Faxas-Guzmán Juan , Urbina Antonio
Published: August 2016

Data Mining techniques have been applied to data collected from a 222 kWp CdTe (Cadmium Telluride) photovoltaic (PV) generator to predict faults or special conditions that occurs due to shadows, bad weather, soiling, and technical faults. Five types of errors have been distinguished and its impact on the PV system performance has been evaluated. Up to date, this computing approach has needed the simultaneous measurement of environmental attributes that an array of sensors collected. This study presents a model to assess the state of the PV (photovoltaic) generator and an algorithm that classifies its state without measuring ambient conditions. The result of a 222 kWp CdTe PV case study shows how the application of computing learning algorithms can be used to improve the management and performance of the photovoltaic generators and underlines the environmental parameters as clue attributes to find faults during the PV performance. Although the application of this method requires computational effort, the result deals with an easy-implementing decision tree, which can be installed in small device.
Near-bandgap optical properties of pseudomorphic GeSn alloys grown by molecular beam epitaxy
Authors: D'Costa Vijay Richard , Wang Wei , Yeo Yee-Chia
Published: August 2016

We investigated the compositional dependence of the near-bandgap dielectric function and the E0 critical point in pseudomorphic Ge1-xSnx alloys grown on Ge (100) substrate by molecular beam epitaxy. The complex dielectric functions were obtained using spectroscopic ellipsometry from 0.5 to 4.5 eV at room temperature. Analogous to the E1 and E1+Δ1 transitions, a model consisting of the compositional dependence of relaxed alloys along with the strain contribution predicted by the deformation potential theory fully accounts for the observed compositional dependence in pseudomorphic alloys.
Optimization schemes for efficient multiple exciton generation and extraction in colloidal quantum dots
Authors: Damtie Fikeraddis A. , Karki Khadga J. , Pullerits Tõnu , Wacker Andreas
Published: August 2016

Multiple exciton generation (MEG) is a process in which more than one electron hole pair is generated per absorbed photon. It allows us to increase the efficiency of solar energy harvesting. Experimental studies have shown the multiple exciton generation yield of 1.2 in isolated colloidal quantum dots. However real photoelectric devices require the extraction of electron hole pairs to electric contacts. We provide a systematic study of the corresponding quantum coherent processes including extraction and injection and show that a proper design of extraction and injection rates enhances the yield significantly up to values around 1.6.
Impact of water dilution and cation tail length on ionic liquid characteristics: Interplay between polar and non-polar interactions
Authors: Hegde Govind A. , Bharadwaj Vivek S. , Kinsinger Corey L. , Schutt Timothy C. , Pisierra Nichole R. , Maupin C. Mark
Published: August 2016

The recalcitrance of lignocellulosic biomass poses a major challenge that hinders the economical utilization of biomass for the production of biofuel, plastics, and chemicals. Ionic liquids have become a promising solvent that addresses many issues in both the pretreatment process and the hydrolysis of the glycosidic bond for the deconstruction of cellulosic materials. However, to make the use of ionic liquids economically viable, either the cost of ionic liquids must be reduced, or a less expensive solvent (e.g., water) may be added to reduce the overall amount of ionic liquid used in addition to reducing the viscosity of the binary liquid mixture. In this work, we employ atomistic molecular dynamics simulations to investigate the impact of water dilution on the overall liquid structure and properties of three imidazolium based ionic liquids. It is found that ionic liquid-water mixtures exhibit characteristics that can be grouped into two distinct regions, which are a function of the ionic liquid concentration. The trends observed in each region are found to correlate with the ordering in the local structure of the ionic liquid that arises from the dynamic interactions between the ion pairs. Simulation results suggest that there is a high level of local ordering in the molecular structure at high concentrations of ionic liquids that is driven by the aggregation of the cationic tails and the anion-water interactions. It is found that as the concentration of ionic liquids in the binary mixture is decreased, there is a point at which the competing self and cross interaction energies between the ionic liquid and water shifts away from a cation-anion dominated regime, which results in a significant change in the mixture properties. This break point, which occurs around 75% w/w ionic liquids, corresponds to the point at which water molecules percolate into the ionic liquid network disrupting the ionic liquids’ nanostructure. It is observed that as the cationic alkyl tail length increases, the changes in the binary mixtures’ properties become more pronounced.
MHD effects and heat transfer for the UCM fluid along with Joule heating and thermal radiation using Cattaneo-Christov heat flux model
Authors: Shah S. , Hussain S. , Sagheer M.
Published: August 2016

Present study examines the numerical analysis of MHD flow of Maxwell fluid with thermal radiation and Joule heating by considering the recently developed Cattaneo-Christov heat flux model which explains the time relaxation characteristics for the heat flux. The objective is to analyze the governing parameters such as viscoelastic fluid parameter, Magnetic parameter, Eckert and Prandtl number’s impact on the velocity and temperature profiles through graphs and tables. Suitable similarity transformations have been used to reduce the formulated PDEs into a system of coupled non-linear ODEs. Shooting technique has been invoked for finding the numerical solutions of the dimensionless velocity and temperature profiles. Additionally, the MATLAB built-in routine bvp4c has also been used to verify and strengthen the results obtained by shooting method. From some special cases of the present work, a comparison with the previously published results has been presented.
Effect of fluid motion on the impact erosion by a micro-particle on quartz crystals
Authors: Cai D. H. , Qi H. , Wen D. H. , Zhang L. , Yuan Q. L. , Chen Z. Z.
Published: August 2016

Abrasive slurry jet (ASJ) is a promising technology to process a variety of materials with advantages of high flexibility, no heat affected zone and high cutting efficiency. In this paper, the impressions generated on a quartz crystal specimen by the impacts of micro-particles laden in a water flow and the associated impact erosion mechanisms are presented and discussed in order to effectively and efficiently control the machining quality. Both brittle and ductile mode erosions coexist in the machining process due to the influence of the fluid motion on the trajectories of particles near the target surface. Large-scale craters produced by brittle conchoidal fractures associated with crashed zone, radial and lateral cracks, dominate the erosion process at large jet impact angles while small-scale craters involving micro-ploughing and micro-cutting are produced by the ductile mode erosion at small jet impact angles. The relation between the process parameters and the overall average volume of craters has also been quantitatively analyzed. A combination of small jet impact angle and abrasive particles and low water pressure is preferred for improving the surface quality after the ASJ machining process caused by the more formation of ductile mode induced craters on the target material, but it is at the sacrifice of the material removal rate as well.
Resonant TMR inversion in LiF/EuS based spin-filter tunnel junctions
Authors: Liu Fen , Yang Yihang , Xue Qian , Gao Zhiwei , Chen Aixi , Miao Guo-Xing
Published: August 2016

Resonant tunneling can lead to inverse tunnel magnetoresistance when impurity levels rather than direct tunneling dominate the transport process. We fabricated hybrid magnetic tunnel junctions of CoFe/LiF/EuS/Ti, with an epitaxial LiF energy barrier joined with a polycrystalline EuS spin-filter barrier. Due to the water solubility of LiF, the devices were fully packaged in situ. The devices showed sizeable positive TMR up to 16% at low bias voltages but clearly inverted TMR at higher bias voltages. The TMR inversion depends sensitively on the thickness of LiF, and the tendency of inversion disappears when LiF gets thick enough and recovers its intrinsic properties.
Theoretical study of the decomposition pathways and products of C5- perfluorinated ketone (C5 PFK)
Authors: Fu Yuwei , Wang Xiaohua , Li Xi , Yang Aijun , Han Guohui , Lu Yanhui , Wu Yi , Rong Mingzhe
Published: August 2016

Due to the high global warming potential (GWP) and increasing environmental concerns, efforts on searching the alternative gases to SF6, which is predominantly used as insulating and interrupting medium in high-voltage equipment, have become a hot topic in recent decades. Overcoming the drawbacks of the existing candidate gases, C5- perfluorinated ketone (C5 PFK) was reported as a promising gas with remarkable insulation capacity and the low GWP of approximately 1. Experimental measurements of the dielectric strength of this novel gas and its mixtures have been carried out, but the chemical decomposition pathways and products of C5 PFK during breakdown are still unknown, which are the essential factors in evaluating the electric strength of this gas in high-voltage equipment. Therefore, this paper is devoted to exploring all the possible decomposition pathways and species of C5 PFK by density functional theory (DFT). The structural optimizations, vibrational frequency calculations and energy calculations of the species involved in a considered pathway were carried out with DFT-(U)B3LYP/6-311G(d,p) method. Detailed potential energy surface was then investigated thoroughly by the same method. Lastly, six decomposition pathways of C5 PFK decomposition involving fission reactions and the reactions with a transition states were obtained. Important intermediate products were also determined. Among all the pathways studied, the favorable decomposition reactions of C5 PFK were found, involving C-C bond ruptures producing Ia and Ib in pathway I, followed by subsequent C-C bond ruptures and internal F atom transfers in the decomposition of Ia and Ib presented in pathways II + III and IV + V, respectively. Possible routes were pointed out in pathway III and lead to the decomposition of IIa, which is the main intermediate product found in pathway II of Ia decomposition. We also investigated the decomposition of Ib, which can undergo unimolecular reactions to give the formation of IV a, IV b and products of CF3 + CF-CF3 in pathway IV. Although IV a is dominant to a lesser extent due to its relative high energy barrier, its complicated decomposition pathway V was also studied and CF3, C = CF2 as well as C-CF3 species were found as the ultimate products. To complete the decomposition of C5 PFK, pathway V I of Ic decomposition was fully explored and the final products were obtained. Therefore, the integrate decomposition scheme of C5 PFK was proposed, which contains six pathways and forty-eight species (including all the reactants, products and transition states). This work is hopeful to lay a theoretical basis for the insulating properties of C5 PFK.