bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrogen Storage on Graphene Sheet: Physisorption, Diffusion and Chemisorbed Pathways by First Principles Calculations / Magazynowanie Wodoru Na Arkuszu Grafenu: Analiza Ścieżek Fizykosorpcji, Dyfuzji I Chemisorpcji Metodą Obliczeń Ab Initio
Authors: Costanzo F. , Silvestrelli P.L. , Ancilotto F.
Published: June 2015

Hydrogen is frequently touted as the “fuel of the future” because of its huge potential as clean energy source, although the large-scale adoption of this technology has yet to be realized. One of the remaining barriers to the utilization of hydrogen energy is an efficient and inexpensive means of hydrogen storage. In this work we investigate the nature of this process by first principle calculation.

In particular, we study the way in which the H2 molecule can interact with graphene sheet through physisorption and chemisorption mechanism.

The first mechanism involves the condensation of the hydrogen molecule on the graphene as a result of weak van der Waals forces, while the chemisorption mechanism involves the preliminary dissociation of the H2 molecule and the subsequent reaction of hydrogen atoms with the unsatured C-C bonds to form C-H bonds.

To study carefully the possible physisorbed configurations on the graphene sheet, we take in to account van der Waals (vdW) interactions in DFT using the new method (DFT/vdW-WF) recently developed in our group and based on the concept of maximally localized Wannier functions.

There are three possible way in which the H2 molecule can adapt to the structure of graphene: the hollow, the bridge and the top site called H, B and T configurations, respectively. We find the hollow site to be most stable physisorbed state with a binding energy of -50 meV. This value, in agreement with experimental results, is also compared with other vdW-correction methods as described in the following paper.

Diffusion of the physisorbed configurations on the graphene sheet and activated reaction pathways in which the molecule starts from a physisorbed configuration to end up in a chemisorbed configurations have also been studied.
The Physical and Numerical Mesoscale Modeling of Cold Wire Drawing Process of Hardly Deformable Biocompatible Magnesium Alloys / Fizyczne I Numeryczne Modelowanie W Mezo Skali Procesu Ciągnienia Na Zimno Trudno Odkształcalnych Stopów Magnezu O Podwyższonej Biozgodności
Authors: Milenin A. , Kustra P. , Byrska-Wójcik D.
Published: June 2015

The problem of determination of the cold low diameter wire (diameter less than 0.1mm) drawing process parameters for hardly deformable biocompatible magnesium alloys by using the mathematical mesoscale model is described in the paper. The originality of the considered alloys (MgCa0.8, A×30) is the intergranular fracture mechanism associated with small strains (0.07-0.09). In previous authors works it was proven that the material state directly before appearance of the microcracks is in the optimal state from the point of view of the recovery of the plasticity by annealing. The forecasting of this material state in drawing process requires the development of the model of intergranular fracture initiation and using this model in two cases:

- modeling of the in-situ tests, what allows calibrating and validating of the model;

- modeling of the drawing process, what allows optimizing of the drawing parameters.

A new model of the microcracks initiation in mesoscale using the boundary element method is proposed. The in-situ tests, which allowed observing the microstructure evolution during deformation, are used for the calibration and validation purpose. The model was implemented into self-developed FE software Drawing2d, which is dedicated to the drawing process. The results of mesoscale simulation were verified by the experimental drawing process of 0.07 mm diameter wires according to developed technology. It was shown by analysis of microstructure that the model allows forecasting the microcracks initiation during the wire drawing process.
Hybrid Adhesive Bonded and Riveted Joints – Influence of Rivet Geometrical Layout on Strength of Joints / Połączenia Hybrydowe Klejowo-Nitowe - Wpływ Geometrii Rozmieszczenia Nitów Na Wytrzymałość Połączeń
Authors: Sadowski T. , Zarzeka-Raczkowska E.
Published: June 2015

The hybrid adhesive bonded and riveted joints have wider and wider application in different branches of engineering: aerospace, mechanical, civil etc. The hybrid joints’ strength is 1.5 to 3 times higher than only adhesive bonded joints’ strength. The hybrid joints characterize higher reliability during long-term working.

In this article we present the influence of rivets’ lay-out geometry on the hybrid adhesive bonded/riveted joints response to mechanical loading. Experimental research was carried using 3-D digital image correlation system ARAMIS. This system enables monitoring of the deformation processes of the hybrid joint specimen up to failure. We analysed the state of deformation of the adhesive bonded double-lap joints reinforced by different numbers of rivets. The hybrid joint specimens were subjected to the uniaxial tensile test. Moreover, the influence of geometry of individual number of rivets’ layout (rivets arranged in one or more rows) for hybrid joint strength was studied.

Experimental research was completed and supported by the computer simulations of the whole deformation processes of metal layers (aluminum), adhesive layers and rivets. Numerical simulations were conducted with the ABAQUS programme. The analysis of stress concentrations in different parts of the hybrid joint and their behaviour up to failure were investigated.

Finally, the analysis and the comparison of the obtained results confirmed the influence of rivets’ lay-out geometry not only on rivets joints but also on the hybrid adhesive bonded/riveted joints.
Numerical Analysis of Rolling Extrusion Process of a Hollow Hub / Analiza Numeryczna Procesu Przepychania Obrotowego Piasty Drążonej
Authors: Bartnicki J.
Published: June 2015

This paper presents the results of numerical calculations of rolling extrusion process of a hollow hub. Simulations were made by means of software Deform 3D in three dimensional state of strain. Distributions of effective stress, effective strain and damage criterion in the rolled extruded product were analyzed. Verification of metal flow during process allowed to design tools for experimental verification in PO-2 laboratory rolling - extrusion aggregate. For these needs also process force parameters were calculated.
The Influence of Radiation Model on the Distribution of Heat Flux in the Pusher Furnace / Wpływ Modelu Promieniowania Na Rozkład Gęstości Strumienia Ciepła W Piecu Przepychowym
Authors: Gołdasz A. , Malinowski Z. , Telejko T. , Rywotycki M. , Szajding A.
Published: June 2015

A three dimensional numerical model of the heat exchange during a charge heating process in a pusher furnace, using the finite element method, was used in this study. The radiative heat exchange in the furnace chamber was carried out based on two methods: the zone method and the method of basing on the average configuration ratio. In the zone method the flux of radiation energy reaching the surface of the heated charge was determined by performing calculations of brightness in a multi-surface closed system which is the pusher furnace chamber filled with an emitting-absorbing medium. In the second case an average configuration ratio was used by setting the radiation energy flux through linking the walls temperature with the furnace atmosphere temperature.
Application of CAE Systems in Forming of Drawpieces with Use Rubber-Pad Forming Processes / Zastosowanie Systemów CAE W Projektowaniu Procesów Tłoczenia Z Użyciem Odkształcalnych Narzędzi
Authors: Woźniak D. , Głowacki M. , Hojny M. , Pieja T.
Published: June 2015

This article shows example result of computer simulations supporting production process of bearing housing of aircraft engine. Verification of both deep drawing process project and tools design were carried out using finite element models implemented in eta/Dynaform 5.8.1 system and LS-DYNA solver. Wrinkling and fracture of the material were the main phenomena subjected to the investigation on the way of numerical analysis. A number of computer simulations were carried out in aim to analyze the deformation and strain distribution in the final product, as well as to eliminate the mentioned defects. In addition the comparison of results of both industrial tests and computer simulation was done.
The Effect of Stand-Off Distance on the Structure and Properties of Zirconium – Carbon Steel Bimetal Produced by Explosion Welding / Wpływ Odległości Blach Na Strukturę I Własności Bimetalu Cyrkon - Stal Wytworzonego Technologią Zgrzewania Wybuchowego
Authors: Prażmowski M. , Paul H.
Published: June 2015

This study focuses on the effect of the stand-off distance between the bonded plates on the properties of zirconium (Zr700) - steel (P355NL2) bimetal produced by explosion welding.

Bonding trials were carried out in parallel arrangement at constant detonation velocity. The analyses of microstructural transformations occurring in the bond zone and mechanical properties of the clad were performed for as-bonded welds, i.e. immediately following explosion welding. A general description of the obtained welds was made (height and length of the wave was determined) and the quantitative fraction of the melt zones was calculated along the bond’s length. Using optical microscopy and scanning electron microscopy (SEM) enabled the assessment of the quality of the formed bonds, initial identification of phases and quantitative analysis of the individual phases on the longitudinal section. The microhardness results were used in the analysis of hardening changes at the interface area.

The completed research proves the potential to obtain a proper bond for zirconium/carbon steel sheets. A strong effect of the stand-off distance on the strength properties of the fabricated plates was observed, and the ’direction’ of these transformations was pointed out. Optical microscopy and SEM examinations allowed determining the characteristic of the bond interface for diverse stand-off distances. It was established that increasing the stand-off distance between the plates causes the reduction of the melt area along the length of the bond, which improves strength properties of the bimetal. The analysis of the strength distribution performed based on the microhardness measurements showed that the changes occur within the distances up to 500µm from the bond interface and the highest hardening, for both zirconium and steel, is directly at the interface and then successively decreases.
Thermo-Mechanical Analysis of a Lever Preform Forming from Magnesium Alloy AZ31 / Termomechaniczna Analiza Kształtowania Przedkuwki Dźwigni Ze Stopu Magnezu AZ31
Authors: Tomczak J. , Pater Z. , Bulzak T.
Published: June 2015

This paper presents the results of numerical analysis of metal forming process of a lever preform from magnesium alloy AZ31, which will be used as a semi-finished product in the forging process of a lever part. Presently, the lever forging is formed from semi-finished product in the form of a bar, which is connected with large material losses. Numerical simulations were made for two different metal forming methods: forging longitudinal rolling and cross-wedge rolling. Calculations were conducted basing on finite element method (FEM), applying commercial software DEFORM-3D. Geometrical models used in calculations were discussed. Simulations, made in conditions of three dimensional state of strain, allowed for determining distributions of strain intensity, temperature, cracking criterion, and mainly for determining the possibility of a lever preform manufacturing on the basis of rolling processes. Considering the obtained results of numerical simulations, the design of tools for semi-finished products rolling was worked out; these semi-finished products will be used for experimental verification of the lever preforms forming.
Numerical Modelling of Thermal and Structural Strain in Laser Welding Process / Modelowanie Numeryczne Odkształceń Cieplnych I Strukturalnych W Procesie Spawania Techniką Laserową
Authors: Piekarska W. , Kubiak M. , Saternus Z.
Published: June 2015

This work concerns numerical modelling of thermal and structural strain, resulting in heating and cooling of laser butt-welded joints. Numerical analysis of strain is carried out in Abaqus FEA. Through the use of additional author’s subroutines, the structural strain caused by phase transformations during heating and cooling of welded elements is taken into account in the analysis. V.I. Machnienko models as well as Continuous Heating Transformation (CHT) and Continuous Cooling Transformation (CCT) diagrams for S355 steel are implemented into UEXPAN subroutine in order to determine the kinetics of phase transformation in the solid state. The model takes into account thermomechanical properties of the base material varying with temperature.

The paper presents results of numerical simulation of temperature field, predicted structural composition, thermal and structural strain in laser butt-welded joints.
Forging on Hammer of Rim Forging from Titanium Alloy Ti6Al4V / Kucie Na Młocieodkuwki Felgi Ze Stopu Tytanu Ti6Al4V
Authors: Gontarz A. , Pater Z. , Drozdowski K.
Published: June 2015

This paper presents the research results of hammer forging process of a plane wheel rim forging from titanium alloy Ti6Al4V. The research works were divided into two stages. The first concerned the theoretical analysis based on numerical simulations of the worked out forging technology. Distributions of temperature, strain, damage criterion according to Cockroft-Latham, material flow kinematics and force parameters were evaluated. It was stated that the danger of overheating and material cracking in the forging does not exist. Large force values present in the process means that problems with tools durability may appear. Satisfactory results of the theoretical analysis provided the basis for conducting the second stage of the research works, that is experimental tests in industrial conditions. After dies making forging tests were made in one Polish forging plants, in which a product of good quality was obtained. Manufactured forgings were free from cracks, shape faults and fulfilled requirements concerning mechanical properties.
Investigation of Sheet-Titanium Forming with Flexible Tool – Experiment and Simulation / Badanie Kształtowania Blach Tytanowych Z Wykorzystaniem Elastycznego Narzędzia - Doświadczenie I Symulacja
Authors: Adamus J. , Lacki P.
Published: June 2015

In the paper the results of investigation of sheet-titanium forming with flexible tool are presented. Titanium alloy sheets belong to a group of materials which are very hard to deform at ambient temperature. To improve sheet formability forming technology using a semi-flexible tool was implemented. Experiments were carried out on a specially designed for this purpose device. Due to the application of a rubber pad the stress state similar to triaxial compression was produced in the deformed material. Such a stress state made it possible to obtain higher material deformation without risk of fracture. The numerical simulations were used for analysing the flexible forming process. The ADINA System basing on the Finite Element Method (FEM) was applied.
Impact of TV Commercials on Persuasive Speech: A Critical Review
Authors: Begum Minowara
Published: June 2015

With the growth of global economy, TV commercials not only have added a new dimension to the communication process throughout the world, but also have been widely recognized as authentic materials that can be beneficial to the need-based learners. This paper attempts to analyze the performance of two groups of students’ persuasive speech presentations, one in the traditional mode and the other was with TV commercials to examine the impact of using TV commercials in the language classroom. This paper includes the result of a survey conducted on the students of Stamford University Bangladesh. It also discusses the limitations of using TV commercials in the context of learning EFL (English as Foreign Language)/ESL (English as Second Language), particularly in Bangladesh. DOI: http://dx.doi.org/10.3126/nelta.v19i1-2.12078 Journal of NELTA, Vol 19 No. 1-2, December 2014: 32-46
Mediation in Peer Interaction
Authors: Dawadi Saraswati
Published: June 2015

This article examines the strategies used by the high-level English as a foreign language learners to mediate understanding in peer interactions. The data was generated from peer interactions of post graduate level students in their regular classroom. It was found that the students were able to understand communicative intent of their peers and provide support to each other; they worked collaboratively and co-constructed knowledge. They used different strategies to mediate understanding. The major strategies included: repetition, elaboration, definition, contextual cues, scaffolding, paralinguistic cues and real life examples. DOI: http://dx.doi.org/10.3126/nelta.v19i1-2.12079   Journal of NELTA, Vol 19 No. 1-2, December 2014: 47-55
Expectation of Tertiary Students of Bangladesh from ELT Classrooms
Authors: Haque Saifa
Published: June 2015

Expectation influences motivation and performance in Second Language Acquisition (SLA). Students’ expectation also plays a significant role in curriculum development. This paper focuses on the expectations of the students in an English language classroom and how they want to be taught. From a study on 45 students of Stamford University Bangladesh, the researcher tried to find students’ expectations about content, factors behind the expectations and effects of expectations in a language classroom using semi-structured interviews. It was found that students have expectations regarding their course content, teaching-learning style and education management. Several factors such as professional need, education background, social beliefs, personal goals and personality of the students worked behind their expectations and their expectations played a significant role in their classroom behavior and performance. DOI: http://dx.doi.org/10.3126/nelta.v19i1-2.12080 Journal of NELTA, Vol 19 No. 1-2, December 2014: 56-64
Smart Teacher Smart Class Portal in Enhancing Secondary School English Teachers’ English Language Teaching Knowledge in Bangladesh
Authors: Ropum SM Kamruddin , Arafat Md Yasin
Published: June 2015

Smart teacher smart class (STSC) is a portal developed by Dnet which contains curriculum, teachers’ guide, education policy, textbook, lesson plan, multimedia contents, and teaching-learning strategies on different subjects aiming to provide content and pedagogical support to the secondary school teachers in Bangladesh. Making an offline CD, the STSC portal is provided to the respective teachers of secondary schools Dnet works with. The regular use of the STSC portal helps the teachers to improve their knowledge about effective teaching-learning techniques. The study was designed as one group pre-test post-test quasi-experimental method to find the effect of STSC portal on secondary school English teachers’ English language teaching knowledge (ELTK). Twenty eight English teachers from 14 secondary schools were selected purposively to form the group and the tests were administered on them considering 6 months intervention (STSC portal) period. The test was adapted from Cambridge language teaching knowledge (TKT) test focusing on different ELT aspects. The tests scores of the teachers were categorized in 4 knowledge levels: limited, basic, deep and extensive. The findings of the study show that the STSC portal induces a significant improvement of the teachers’ ELTK. Most of the teachers showed better performances in the post-test than the pre-test. Moreover, significance (0.001) and effect size score (0.91) also depict a clear and large effect in enhancing teachers’ ELTK. DOI: http://dx.doi.org/10.3126/nelta.v19i1-2.12087 Journal of NELTA, Vol 19 No. 1-2, December 2014: 147-157
Editorial Vol.19(1-2)
Authors: Shrestha Prithvi N , Dhakal Khagendra Raj , Ojha Laxmi Prasad , Rana Lal Bahadur , Rawal Hima
Published: June 2015

DOI: http://dx.doi.org/10.3126/nelta.v19i1-2.12669 Journal of NELTA, Vol 19 No. 1-2, December 2014: V-VII
The Transcriptional Repressor, MtrR, of the mtrCDE Efflux Pump Operon of Neisseria gonorrhoeae Can Also Serve as an Activator of “off Target” Gene (glnE) Expression
Authors: Johnson Paul , Shafer William
Published: June 2015

MtrR is a well-characterized repressor of the Neisseria gonorrhoeae mtrCDE efflux pump operon. However, results from a previous transcriptional profiling study suggested that MtrR also represses or activates expression of at least sixty genes outside of the mtr locus. Evidence that MtrR can directly repress so-called “off target” genes has previously been reported; in particular, MtrR was shown to directly repress glnA, which encodes glutamine synthetase. In contrast, evidence for the ability of MtrR to directly activate expression of gonococcal genes has been lacking; herein, we provide such evidence. We now report that MtrR has the ability to directly activate expression of glnE, which encodes the dual functional adenyltransferase/deadenylase enzyme GlnE that modifies GlnA resulting in regulation of its role in glutamine biosynthesis. With its capacity to repress expression of glnA, the results presented herein emphasize the diverse and often opposing regulatory properties of MtrR that likely contributes to the overall physiology and metabolism of N. gonorrhoeae.
Stearoyl-CoA Desaturase-1: Is It the Link between Sulfur Amino Acids and Lipid Metabolism?
Authors: Poloni Soraia , Blom Henk , Schwartz Ida
Published: June 2015

An association between sulfur amino acids (methionine, cysteine, homocysteine and taurine) and lipid metabolism has been described in several experimental and population-based studies. Changes in the metabolism of these amino acids influence serum lipoprotein concentrations, although the underlying mechanisms are still poorly understood. However, recent evidence has suggested that the enzyme stearoyl-CoA desaturase-1 (SCD-1) may be the link between these two metabolic pathways. SCD-1 is a key enzyme for the synthesis of monounsaturated fatty acids. Its main substrates C16:0 and C18:0 and products palmitoleic acid (C16:1) and oleic acid (C18:1) are the most abundant fatty acids in triglycerides, cholesterol esters and membrane phospholipids. A significant suppression of SCD-1 has been observed in several animal models with disrupted sulfur amino acid metabolism, and the activity of SCD-1 is also associated with the levels of these amino acids in humans. This enzyme also appears to be involved in the etiology of metabolic syndromes because its suppression results in decreased fat deposits (regardless of food intake), improved insulin sensitivity and higher basal energy expenditure. Interestingly, this anti-obesogenic phenotype has also been described in humans and animals with sulfur amino acid disorders, which is consistent with the hypothesis that SCD-1 activity is influenced by these amino acids, in particularly cysteine, which is a strong and independent predictor of SCD-1 activity and fat storage. In this narrative review, we discuss the evidence linking sulfur amino acids, SCD-1 and lipid metabolism.
In Vivo Cytogenotoxicity of Electronic Waste Leachate from Iloabuchi Electronic Market, Diobu, Rivers State, Nigeria on Allium Cepa
Authors: Babatunde Bolaji , Anabuike Felicity
Published: June 2015

The human and environmental impact of electronic waste is increasing due to its careless disposal. Cytogenotoxicity of electronic waste from Iloabuchi electronic market, Diobu, Rivers State was investigated using the Allium cepa bioassay comprised of the root elongation and chromosome aberration tests. Leachate samples of e-waste analysed were above maximum permissible limits. Toxicity to root growth of A. cepa was evaluated at concentrations of 5%, 10%, 25%, 50%, and 100% showed root growth inhibition at all concentrations of the samples compared to the control and root growth inhibition was concentration dependent. An effective concentration (EC50) at which root growth amounted to 50 % of control for the sample was 37.5%. Various morphological defects of the onion roots were observed including short, crochet roots, C-tumor roots and severe toxic effects where no growth was observed. In the in vivo genotoxity assay, all samples lowered the frequency of mitotic cells in the meristematic region of the roots at statistically significant levels (P < 0.05) compared to the control and mitotic inhibition was also concentration dependent. There was significant induction of aberrations at all concentrations tested compared to control. The high metal content of the e-waste leachate may be responsible for observed cytotoxicity in A. cepa roots cells.
Security of Supply in European Electricity Markets—Determinants of Investment Decisions and the European Energy Union
Authors: Ellenbeck Saskia , Beneking Andreas , Ceglarz Andrzej , Schmidt Peter , Battaglini Antonella
Published: June 2015

The European Union and its Member States are seeking to decarbonize their energy systems, including the electricity sector and, at the same time, pursue market integration. However, renewable energy (RE) deployment and the liberalization of the energy-only market have raised concerns at the national level about the security of electricity supplies in the future. Some actors consider the lack of sufficient investments in generation capacities a threat to supply security. As a consequence, it was proposed that capacity markets solve these problems. The underlying assumption is that the market design is the only determining factor for investments in security of supply options. In this article, we question this narrow view and identify further determinants of the investment decisions of electricity market participants. Based on the insights of institutional sociology and economics, we understand the market to be a social institution that structures the behavioural expectations of market participants. Derived from the theoretical conceptualization and based on qualitative literature review and own work, we find four determinants for investment behaviour beyond the formal market design: Material opportunities, strategic actor behavior and identity, focusing events and discursive expectations about the future. With this perspective, we discuss the introduction of a European Energy Union as a possible tool that might have a great impact on the more informal determinants such as expectations about the future and the construction of a European energy narrative.
Extended Kalman Filter with a Fuzzy Method for Accurate Battery Pack State of Charge Estimation
Authors: Sepasi Saeed , Roose Leon , Matsuura Marc
Published: June 2015

As the world moves toward greenhouse gas reduction, there is increasingly active work around Li-ion chemistry-based batteries as an energy source for electric vehicles (EVs), hybrid electric vehicles (HEVs) and smart grids. In these applications, the battery management system (BMS) requires an accurate online estimation of the state of charge (SOC) in a battery pack. This estimation is difficult, especially after substantial battery aging. In order to address this problem, this paper utilizes SOC estimation of Li-ion battery packs using a fuzzy-improved extended Kalman filter (fuzzy-IEKF) for Li-ion cells, regardless of their age. The proposed approach introduces a fuzzy method with a new class and associated membership function that determines an approximate initial value applied to SOC estimation. Subsequently, the EKF method is used by considering the single unit model for the battery pack to estimate the SOC for following periods of battery use. This approach uses an adaptive model algorithm to update the model for each single cell in the battery pack. To verify the accuracy of the estimation method, tests are done on a LiFePO4 aged battery pack consisting of 120 cells connected in series with a nominal voltage of 432 V.
Quantitative Vulnerability Assessment of Cyber Security for Distribution Automation Systems
Authors: Ye Xiaming , Zhao Junhua , Zhang Yan , Wen Fushuan
Published: June 2015

The distribution automation system (DAS) is vulnerable to cyber-attacks due to the widespread use of terminal devices and standard communication protocols. On account of the cost of defense, it is impossible to ensure the security of every device in the DAS. Given this background, a novel quantitative vulnerability assessment model of cyber security for DAS is developed in this paper. In the assessment model, the potential physical consequences of cyber-attacks are analyzed from two levels: terminal device level and control center server level. Then, the attack process is modeled based on game theory and the relationships among different vulnerabilities are analyzed by introducing a vulnerability adjacency matrix. Finally, the application process of the proposed methodology is illustrated through a case study based on bus 2 of the Roy Billinton Test System (RBTS). The results demonstrate the reasonability and effectiveness of the proposed methodology.
Upgrading a Shrouded Wind Turbine with a Self-Adaptive Flanged Diffuser
Authors: Hu Jun-Feng , Wang Wen-Xue
Published: June 2015

In this paper, a self-adaptive flange is proposed for the wind turbine shrouded by a flanged diffuser to reduce the wind loads acting on the flanged diffuser at high wind velocities. The self-adaptive flange can maintain the advantages of the flanged diffuser at wind velocities lower than the rated velocity and reduce the wind loads acting on the diffuser and blades at higher wind velocities. Numerical analyses of fluid-structure interactions are carried out to investigate the flow field around the diffuser with a self-adaptive flange and the variation of wind load acting on the diffuser due to the reconfiguration of the self-adaptive flange at various wind velocities. Numerical results show that the wind load acting on the total flanged diffuser can be reduced by about 35% at 60 m/s due to the reconfiguration of the self-adaptive flange.
Spatial Variation of Biomass Carbon Density in a Subtropical Region of Southeastern China
Authors: Fu Weijun , Fu Zhuojing , Ge Hongli , Ji Biyong , Jiang Peikun , Li Yongfu , Wu Jiasen , Zhao Keli
Published: June 2015

Spatial pattern information of forest biomass carbon (FBC) density in forest ecosystems plays an important role in evaluating carbon sequestration potentials and forest management. The spatial variation of FBC density in a subtropical region of southeastern China was studied using geostatistics combined with Moran’s I and geographical information systems (GIS). Forest biomass carbon density values were variable, ranging from 0.12 Mg ha−1 to 182.12 Mg ha−1, with an average of 27.33 Mg ha−1. The FBC density had the strongest positive correlation with forest age, followed by forest litter and elevation. The FBC density had significant positive spatial autocorrelation revealed by global Moran’s I. Clear spatial patterns were observed based on local Moran’s I. High FBC density values were mainly distributed in the northwestern and southwestern parts of Zhejiang province, which were related to adopting long-term policy of forest conservation in these areas, while low FBC density values located in the middle part and southeastern coastal area of the study area due to low forest coverage and intensive management of economic forests. The Moran’s I combined with geostatistical interpolation proved to be a useful tool for studying spatial variation of FBC density.
How Moral Codes Evolve in a Trust Game
Authors: Rabanal Jean , Friedman Daniel
Published: June 2015

This paper analyzes the dynamic stability of moral codes in a two population trust game. Guided by a moral code, members of one population, the Trustors, are willing to punish members of the other population, the Trustees, who defect. Under replicator dynamics, adherence to the moral code has unstable oscillations around an interior Nash Equilibrium (NE), but under smoothed best response dynamics we obtain convergence to Quantal Response Equilibrium (QRE).
Selection of Reliable Reference Genes for Gene Expression Studies of a Promising Oilseed Crop, Plukenetia volubilis, by Real-Time Quantitative PCR
Authors: Niu Longjian , Tao Yan-Bin , Chen Mao-Sheng , Fu Qiantang , Li Chaoqiong , Dong Yuling , Wang Xiulan , He Huiying , Xu Zeng-Fu
Published: June 2015

Real-time quantitative PCR (RT-qPCR) is a reliable and widely used method for gene expression analysis. The accuracy of the determination of a target gene expression level by RT-qPCR demands the use of appropriate reference genes to normalize the mRNA levels among different samples. However, suitable reference genes for RT-qPCR have not been identified in Sacha inchi (Plukenetia volubilis), a promising oilseed crop known for its polyunsaturated fatty acid (PUFA)-rich seeds. In this study, using RT-qPCR, twelve candidate reference genes were examined in seedlings and adult plants, during flower and seed development and for the entire growth cycle of Sacha inchi. Four statistical algorithms (delta cycle threshold (ΔCt), BestKeeper, geNorm, and NormFinder) were used to assess the expression stabilities of the candidate genes. The results showed that ubiquitin-conjugating enzyme (UCE), actin (ACT) and phospholipase A22 (PLA) were the most stable genes in Sacha inchi seedlings. For roots, stems, leaves, flowers, and seeds from adult plants, 30S ribosomal protein S13 (RPS13), cyclophilin (CYC) and elongation factor-1alpha (EF1α) were recommended as reference genes for RT-qPCR. During the development of reproductive organs, PLA, ACT and UCE were the optimal reference genes for flower development, whereas UCE, RPS13 and RNA polymerase II subunit (RPII) were optimal for seed development. Considering the entire growth cycle of Sacha inchi, UCE, ACT and EF1α were sufficient for the purpose of normalization. Our results provide useful guidelines for the selection of reliable reference genes for the normalization of RT-qPCR data for seedlings and adult plants, for reproductive organs, and for the entire growth cycle of Sacha inchi.
Graft Remodeling following Transcrestal Sinus Floor Elevation via the Gel-Pressure Technique (GPT) and Pasteous Nano-Crystalline Hydroxyapatite Bone Substitute
Authors: Pommer Bernhard , Unger Ewald , Busenlechner Dieter , Haas Robert , Mailath-Pokorny Georg , Fürhauser Rudolf , Watzek Georg
Published: June 2015

Bone grafting of the maxillary sinus is attempted to compensate for sinus pneumatization and permit reliable insertion of endosseous dental implants for prosthetic rehabilitation. The aim of the present clinical investigation was to study bone regeneration four months after transcrestal sinus floor elevation via the Gel-Pressure Technique (GPT) and application of pasteous nano-crystalline hydroxyapatite bone substitute. A total of 25 patients with deficient alveolar ridges in the posterior maxilla (mean residual bone height: 4.7 ± 1.8 mm) were subjected to 32 flapless transcrestal sinus floor augmentations and simultaneous insertion of 40 implants. Sinus membrane elevation height averaged 11.2 ± 2.7 mm and minimal vertical graft resorption of 0.1 mm was observed after four months. Radiographic bone density averaged 460 Hounsfield units in regions adjacent to the native jawbone (1 to 7 mm distance), while reduction of bone density by −7.2%, −11.3%, −14.8%, −19.6% and −22.7% was recorded in more apical regions of 8, 9, 10, 11, and ≥12 mm distance to the original sinus floor, respectively. The results suggest that graft remodeling is completed up to a distance of 7 mm within a healing period of four months after sinus augmentation using nano-crystalline hydroxyapatite bone substitute material.
Microleakage of Different Self-Adhesive Materials for Lithium Disilicate CAD/CAM Crowns
Authors: Naumova Ella , Valta Alexander , Schaper Katharina , Arnold Wolfgang. , Piwowarczyk Andree
Published: June 2015

Objectives: To evaluate the microleakage and marginal gap of various luting materials after cementing ceramic crowns. Methods: Cervical margins of human molars were designed as circular chamfers. Cementation of full-contour ceramic crowns was conducted with zinc-phosphate cement (Harvard cement), resin cement (Panavia F 2.0) and self-adhesive resin cements (RelyX Unicem, BifixSE, MaxCem Elite, PermaCem2.0, G-Cem). Aging of specimens was performed in artificial saliva, at 37 °C for four weeks and thermocycling. The marginal gap was measured with a scanning electron microscope and silver precipitation within the microleakage. All data were compared statistically. Results: Independent of the margin preparation, the highest median value for microleakage was 320.2 μm (Harvard cement), and the lowest was 0 μm (Panavia F 2.0). The median value for enamel was 0 µm and for dentin 270.9 μm (p < 0.001), which was independent of the luting material. The marginal and absolute marginal gaps were not significantly different between the tested materials. There was no correlation between microleakage and the marginal gaps. Conclusion: Significant differences in microleakage were found between the tested luting materials (p < 0.05). Independent from the luting materials, the microleakage in dentin showed significantly higher values than in enamel.
Synthesis of a Novel Cysteine-Incorporated Anthraquinone Derivative and Its Structural Properties
Authors: Nomoto Akihiro , Taniguchi Toshihide , Minatobe Yuta , Katao Syouhei , Kakiuchi Kiyomi , Yano Shigenobu , Ogawa Akiya
Published: June 2015

A novel cysteine-incorporated anthraquinone derivative was synthesized, and its molecular structure was determined by X-ray crystal analysis. Each mercapto group was located separately and did not form a disulfide bond, and hydrogen bondings and π-π interaction were observed from the packing structure.
Long Non-Coding RNAs Dysregulation and Function in Glioblastoma Stem Cells
Authors: Zhang Xiaoqin , Kiang Karrie , Zhang Grace , Leung Gilberto
Published: June 2015

Glioblastoma multiforme (GBM), the most common form of primary brain tumor, is highly resistant to current treatment paradigms and has a high rate of recurrence. Recent advances in the field of tumor-initiating cells suggest that glioblastoma stem cells (GSCs) may be responsible for GBM’s rapid progression, treatment resistance, tumor recurrence and ultimately poor clinical prognosis. Understanding the biologically significant pathways that mediate GSC-specific characteristics offers promises in the development of novel biomarkers and therapeutics. Long non-coding RNAs (lncRNAs) have been increasingly implicated in the regulation of cancer cell biological behavior through various mechanisms. Initial studies strongly suggested that lncRNA expressions are highly dysregulated in GSCs and may play important roles in determining malignant phenotypes in GBM. Here, we review available evidence on aberrantly expressed lncRNAs identified by high throughput microarray profiling studies in GSCs. We also explore the potential functional pathways by analyzing their interactive proteins and miRNAs, with a view to shed lights on how this novel class of molecular candidates may mediate GSC maintenance and differentiation.
Low-Density Lipoprotein Receptor-Related Protein 6 (LRP6) Is a Novel Nutritional Therapeutic Target for Hyperlipidemia, Non-Alcoholic Fatty Liver Disease, and Atherosclerosis
Authors: Go Gwang-woong
Published: June 2015

Low-density lipoprotein receptor-related protein 6 (LRP6) is a member of the low-density lipoprotein receptor family and has a unique structure, which facilitates its multiple functions as a co-receptor for Wnt/β-catenin signaling and as a ligand receptor for endocytosis. The role LRP6 plays in metabolic regulation, specifically in the nutrient-sensing pathway, has recently garnered considerable interest. Patients carrying an LRP6 mutation exhibit elevated levels of LDL cholesterol, triglycerides, and fasting glucose, which cooperatively constitute the risk factors of metabolic syndrome and atherosclerosis. Since the discovery of this mutation, the general role of LRP6 in lipid homeostasis, glucose metabolism, and atherosclerosis has been thoroughly researched. These studies have demonstrated that LRP6 plays a role in LDL receptor-mediated LDL uptake. In addition, when the LRP6 mutant impaired Wnt-LRP6 signaling, hyperlipidemia, non-alcoholic fatty liver disease, and atherosclerosis developed. LRP6 regulates lipid homeostasis and body fat mass via the nutrient-sensing mechanistic target of the rapamycin (mTOR) pathway. Furthermore, the mutant LRP6 triggers atherosclerosis by activating platelet-derived growth factor (PDGF)-dependent vascular smooth muscle cell differentiation. This review highlights the exceptional opportunities to study the pathophysiologic contributions of LRP6 to metabolic syndrome and cardiovascular diseases, which implicate LRP6 as a latent regulator of lipid metabolism and a novel therapeutic target for nutritional intervention.
Warpage Analysis of Electroplated Cu Films on Fiber-Reinforced Polymer Packaging Substrates
Authors: Kim Cheolgyu , Lee Tae-Ik , Kim Min , Kim Taek-Soo
Published: June 2015

This paper presents a warpage analysis method that predicts the warpage behavior of electroplated Cu films on glass fiber-reinforced polymer (GFRP) packaging substrates. The analysis method is performed using the following sequence: fabricate specimens for scanning 3D contours, transform 3D data into curvatures, compute the built-in stress of the film using a stress-curvature analytic model, and verify it through comparisons of the finite element method (FEM) simulations with the measured data. The curvature is used to describe the deflection and warpage modes and orientations of the specimen. Two primary factors that affect the warpage behavior of the electroplated Cu film on FRP substrate specimens are investigated. The first factor is the built-in stress in a Cu film that explains the room temperature warpage of the specimen under no thermal process. The second factor is the misfit of the coefficient of thermal expansion (CTE) between the Cu and FRP layer, which is a dominant factor during the temperature change. The calculated residual stress, and predicted curvatures using FEM simulation throughout the reflow process temperature range between 25 and 180 °C are proven to be accurate by the comparison of the FEM simulations and experiment measurements.
Retrieval of Cirrus Cloud Optical Depth under Day and Night Conditions from MODIS Collection 6 Cloud Property Data
Authors: Heidinger Andrew , Li Yue , Baum Bryan , Holz Robert , Platnick Steven , Yang Ping
Published: June 2015

This paper presents a technique to generate cirrus optical depth and particle effective size estimates from the cloud emissivities at 8.5, 11 and 12 μm contained in the Collection-6 (C6) MYD06 cloud product. This technique employs the latest scattering models and scattering radiative transfer approximations to estimate cloud optical depth and particle effective size using efficient analytical formulae. Two scattering models are tested. The first is the same scattering model as that used in the C6 MYD06 solar reflectance products. The second model is an empirical model derived from radiometric consistency. Both models are shown to generate optical depths that compare well to those from constrained CALIPSO retrievals and MYD06. In terms of effective radius retrievals, the results from the radiometric empirical model agree more closely with MYD06 than those from the C6 model. This analysis is applied to AQUA/MODIS data collocated with CALIPSO/CALIOP during January 2010.
A Least Squares Collocation Method for Accuracy Improvement of Mobile LiDAR Systems
Authors: Mao Qingzhou , Zhang Liang , Li Qingquan , Hu Qingwu , Yu Jianwei , Feng Shaojun , Ochieng Washington , Gong Hanlu
Published: June 2015

In environments that are hostile to Global Navigation Satellites Systems (GNSS), the precision achieved by a mobile light detection and ranging (LiDAR) system (MLS) can deteriorate into the sub-meter or even the meter range due to errors in the positioning and orientation system (POS). This paper proposes a novel least squares collocation (LSC)-based method to improve the accuracy of the MLS in these hostile environments. Through a thorough consideration of the characteristics of POS errors, the proposed LSC-based method effectively corrects these errors using LiDAR control points, thereby improving the accuracy of the MLS. This method is also applied to the calibration of misalignment between the laser scanner and the POS. Several datasets from different scenarios have been adopted in order to evaluate the effectiveness of the proposed method. The results from experiments indicate that this method would represent a significant improvement in terms of the accuracy of the MLS in environments that are essentially hostile to GNSS and is also effective regarding the calibration of misalignment.
Consistent Positive Co-Variation between Fluctuating Asymmetry and Sexual Trait Size: A Challenge to the Developmental Instability-Sexual Selection Hypothesis
Authors: Polak Michal , Hooker Kassie , Tyler Frances
Published: June 2015

The developmental instability (DI)-sexual selection hypothesis proposes that large size and symmetry in secondary sexual traits are favored by sexual selection because they reveal genetic quality. A critical prediction of this hypothesis is that there should exist negative correlations between trait fluctuating asymmetry (FA) and size of condition dependent sexual traits; condition dependent traits should reveal an organism’s overall health and vigor, and be influenced by a multitude of genetic loci. Here, we tested for the predicted negative FA-size correlations in the male sex comb of Drosophila bipectinata. Among field-caught males from five widely separated geographic localities, FA-size correlations were consistently positive, despite evidence that sex comb size is condition dependent. After controlling for trait size, FA was significantly negatively correlated with body size within several populations, indicating that developmental instability in the comb may reveal individual genetic quality. We suggest the possibility that condition dependent traits in some cases tap into independent units of the genome (a restricted set of genes), rather than signaling overall genetic properties of the organism. There were pronounced among-population differences in both comb FA and size, and these traits were positively correlated across populations, recapitulating the within-population patterns. We conclude that the results are inconsistent with the DI-sexual selection hypothesis, and discuss potential reasons for positive FA-size co-variation in sexual traits.
Analysis of Ergot Alkaloids
Authors: Crews Colin
Published: June 2015

The principles and application of established and newer methods for the quantitative and semi-quantitative determination of ergot alkaloids in food, feed, plant materials and animal tissues are reviewed. The techniques of sampling, extraction, clean-up, detection, quantification and validation are described. The major procedures for ergot alkaloid analysis comprise liquid chromatography with tandem mass spectrometry (LC-MS/MS) and liquid chromatography with fluorescence detection (LC-FLD). Other methods based on immunoassays are under development and variations of these and minor techniques are available for specific purposes.