bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of a Microfluidic System for Red Blood Cell Aggregation Investigation
Authors: Mehri R. , Mavriplis C. , Fenech M.
Published: April 2014

The purpose of this paper is to design a microfluidic apparatus capable of providing controlled flow conditions suitable for red blood cell (RBC) aggregation analysis. The linear velocity engendered from the controlled flow provides constant shear rates used to qualitatively analyze RBC aggregates. The design of the apparatus is based on numerical and experimental work. The numerical work consists of 3D numerical simulations performed using a research computational fluid dynamics (CFD) solver, Nek5000, while the experiments are conducted using a microparticle image velocimetry system. A Newtonian model is tested numerically and experimentally, then blood is tested experimentally under several conditions (hematocrit, shear rate, and fluid suspension) to be compared to the simulation results. We find that using a velocity ratio of 4 between the two Newtonian fluids, the layer corresponding to blood expands to fill 35% of the channel thickness where the constant shear rate is achieved. For blood experiments, the velocity profile in the blood layer is approximately linear, resulting in the desired controlled conditions for the study of RBC aggregation under several flow scenarios.
Flow Boiling Enhancement in Microtubes With Crosslinked pHEMA Coatings and the Effect of Coating Thickness
Authors: Çıkım Taha , Armağan Efe , Ozaydin Ince Gozde , Koşar Ali
Published: April 2014

In this experimental study, flow boiling in mini/microtubes was investigated with surface enhancements provided by crosslinked polyhydroxyethylmethacrylate (pHEMA) coatings, which were used as a crosslinker coating type with different thicknesses (∼50 nm, 100 nm, and 150 nm) on inner microtube walls. Flow boiling heat transfer experiments were conducted on microtubes (with inner diameters of 249 μm, 507 μm, and 908 μm) coated with crosslinked pHEMA coatings. pHEMA nanofilms were deposited with initiated chemical vapor deposition (iCVD) technique. De-ionized water was utilized as the working fluid in this study. Experimental results obtained from coated microtubes were compared to their plain surface counterparts at two different mass fluxes (5000 kg/m2 s and 20,000 kg/m2 s), and significant enhancements in critical heat flux (up to 29.7%) and boiling heat transfer (up to 126.2%) were attained. The enhancement of boiling heat transfer was attributed to the increase in nucleation site density and incidence of bubbles departing from surface due to porous structure of crosslinked pHEMA coatings. The underlying mechanism was explained with suction-evaporation mode. Moreover, thicker pHEMA coatings resulted in larger enhancements in both CHF and boiling heat transfer.
Richardson Extrapolation-Based Discretization Uncertainty Estimation for Computational Fluid Dynamics
Authors: Phillips Tyrone S. , Roy Christopher J.
Published: April 2014

This study investigates the accuracy of various Richardson extrapolation-based discretization error and uncertainty estimators for problems in computational fluid dynamics (CFD). Richardson extrapolation uses two solutions on systematically refined grids to estimate the exact solution to the partial differential equations (PDEs) and is accurate only in the asymptotic range (i.e., when the grids are sufficiently fine). The uncertainty estimators investigated are variations of the grid convergence index and include a globally averaged observed order of accuracy, the factor of safety method, the correction factor method, and least-squares methods. Several 2D and 3D applications to the Euler, Navier–Stokes, and Reynolds-Averaged Navier–Stokes (RANS) with exact solutions and a 2D turbulent flat plate with a numerical benchmark are used to evaluate the uncertainty estimators. Local solution quantities (e.g., density, velocity, and pressure) have much slower grid convergence on coarser meshes than global quantities, resulting in nonasymptotic solutions and inaccurate Richardson extrapolation error estimates; however, an uncertainty estimate may still be required. The uncertainty estimators are applied to local solution quantities to evaluate accuracy for all possible types of convergence rates. Extensions were added where necessary for treatment of cases where the local convergence rate is oscillatory or divergent. The conservativeness and effectivity of the discretization uncertainty estimators are used to assess the relative merits of the different approaches.
Unsteady Conduction in a Horizontal Solid Cylinder Cooled by Natural Convection: Alternate Lumped Criterion in Terms of the Solid Material
Authors: Campo Antonio , Sieres Jaime
Published: April 2014

Within the framework of the potent lumped model, unsteady heat conduction takes place in a solid body whose space–mean temperature varies with time. Conceptually, the lumped model subscribes to the notion that the external convective resistance at the body surface dominates the internal conductive resistance inside the body. For forced convection heat exchange between a solid body and a neighboring fluid, the criterion entails to the lumped Biot number Bil=(h¯/ks)(V/A)<0.1, in which the mean convective coefficient h¯ depends on the impressed fluid velocity. However, for natural convection heat exchange between a solid body and a fluid, the mean convective coefficient h¯ depends on the solid-to-fluid temperature difference. As a consequence, the lumped Biot number must be modified to read Bil=(h¯max/ks)(V/A)<0.1, wherein h¯max occurs at the initial temperature Ti for cooling or at a future temperature Tfut for heating. In this paper, the equivalence of the lumped Biot number criterion is deduced from the standpoint of the solid thermal conductivity through the solid-to-fluid thermal conductivity ratio.
Design, Evaluation and Performance Analysis of Staged Low Emission Combustors
Authors: Khandelwal Bhupendra , Banjo Olamilekan , Sethi Vishal
Published: April 2014

The most uncertain and challenging part in the design of a gas turbine has long been the combustion chamber. There has been a large number of experimentations in industry and universities alike to better understand the dynamic and complex processes that occur inside a combustion chamber. This study concentrates on gas turbine combustors, as a whole, and formulates a theoretical design procedure for staged combustors, in particular. Not much of the literature currently available in the public domain provides intensive study on designing staged combustors. The work covers an extensive study of the design methods applied in conventional combustor designs, which includes the reverse flow combustor and the axial flow annular combustors. The knowledge acquired from this study is then applied to develop a theoretical design methodology for double staged (radial and axial) low emission annular combustors. Additionally, a model combustor is designed for each type, radial and axial, of staging using the developed methodology. A prediction of the performance of the model combustors is executed. The main conclusion is that the dimensions of the model combustors obtained from the developed design methodology are within the feasibility limits. The comparison between the radially staged and the axially staged combustor has yielded the predicted results such as a lower NOx prediction for the latter and a shorter combustor length for the former. The NOx emission results of the new combustor models are found to be in the range of 50–60 ppm. However, the predicted NOx results are only very crude and need further detailed study.
High Load (21 Bar IMEP) Dual Fuel RCCI Combustion Using Dual Direct Injection
Authors: Lim Jae Hyung , Reitz Rolf D.
Published: April 2014

Dual-fuel reactivity controlled compression ignition (RCCI) combustion has shown high thermal efficiency and superior controllability with low NOx and soot emissions. However, as in other low temperature combustion (LTC) strategies, the combustion control using low exhaust gas recirculation (EGR) or a high compression ratio at high load conditions has been a challenge. The objective of this work was to examine the efficacy of using dual direct injectors for combustion phasing control of high load RCCI combustion. The present computational work demonstrates that 21 bar gross indicated mean effective pressure (IMEP) RCCI is achievable using dual direct injection. The simulations were done using the KIVA3V-Release 2 code with a discrete multicomponent fuel evaporation model, coupled with sparse analytical Jacobian solver for describing the chemistry of the two fuels (iso-octane and n-heptane). In order to identify an optimum injection strategy a nondominated sorting genetic algorithm II (NSGA II), which is a multiobjective genetic algorithm, was used. The goal of the optimization was to find injection timings and mass splits among the multiple injections that simultaneously minimize the six objectives: soot, nitrogen oxide (NOx), carbon monoxide (CO), unburned hydrocarbon (UHC), indicated specific fuel consumption (ISFC), and ringing intensity. The simulations were performed for a 2.44 liter, heavy-duty engine with a 15:1 compression ratio. The speed was 1800 rev/min and the intake valve closure (IVC) conditions were maintained at 3.42 bar, 90 °C, and 46% EGR. The resulting optimum condition has 12.6 bar/deg peak pressure rise rate, 158 bar maximum pressure, and 48.7% gross indicated thermal efficiency. The NOx, CO, and soot emissions are very low.
Saturation Nucleate Boiling and Correlations for PF-5060 Dielectric Liquid on Inclined Rough Copper Surfaces
Authors: El-Genk Mohamed S. , Suszko Arthur
Published: April 2014

Saturation pool boiling experiments of degassed PF-5060 dielectric liquid investigated nucleate boiling on 13 Cu surfaces with average roughness, Ra, of 0.039 (smooth polished) to 1.79 μm at six inclination angles, θ, from 0 deg (upward facing) to 180 deg (downward facing). Values of the nucleate boiling heat transfer coefficient, hNB, in the upward facing orientation increase with increasing surface roughness and are correlated in terms of the applied heat flux, q: hNB = A qB. The exponent “B” decreases from 0.81 to 0.69 as Ra increases from 0.039 to 1.79 μm, while the coefficient “A” increases with Ra to the power 0.24. The values of the maximum heat transfer coefficient, hMNB, which occurs near the end of the fully developed nucleate boiling region, increase with increasing Ra and decreasing inclination angle. In the upward facing orientation, hNB increases by ∼58% with increasing Ra from 0.134 to 1.79 μm, while hMNB increases by more than 150% compared with that on smooth-polished Cu. Values of hMNB in the downward facing orientation are ∼40% of those in the upward facing orientation.
Filament-Based Fabrication and Performance Analysis of Fiber Bragg Grating Sensors Using Ultrashort Pulse Laser
Authors: Ahmed Farid , Jun Martin B. G.
Published: April 2014

The method of ultrashort pulse filamentation induced refractive index modification is employed to inscribe fiber Bragg grating (FBG) in single-mode optical fiber (SMF). Line-by-line index inscription technique is used to write refractive index modulation in the core of SMF. The proposed pulse filamentation based index modification enables controlled and flexible writing of FBGs in optical fibers. Performance analysis of the fabricated FBG has been carried out for temperature, contact force, pressure, and axial strain sensing. The in-fiber FBG exhibits sensing performance very similar to FBGs commercially available to date. Then, the written FBG is engineered to demonstrate highly sensitive contact force sensor.
Draft Genome Sequences of Two
Arcobacter
Strains Isolated from Human Feces
Authors: Adam Zaky , Whiteduck-Léveillée Kerri , Cloutier Michel , Chen Wen , Lewis Christopher T. , Lévesque C. André , Topp Edward , Lapen David R. , Tambong James T. , Talbot Guylaine , Khan Izhar U. H.
Published: April 2014

Arcobacter
species are members of the family
Campylobacteraceae
and are considered emerging enteropathogens and potential zoonotic agents. Here, we report the draft genome sequences of two
Arcobacter
strains isolated from human feces in an effort to provide further genetic resources for understanding the pathogenic dynamics and diversity of this important genus.
Genome Sequence of the Acrystalliferous Bacillus thuringiensis Serovar Israelensis Strain 4Q7, Widely Used as a Recombination Host
Authors: Jeong Haeyoung , Park Seung-Hwan , Choi Soo-Keun
Published: April 2014

Bacillus thuringiensis
serovar israelensis is well known for its mosquitocidal activity and has long been used as a biopesticide. Herein, we present the genome sequence of
B. thuringiensis
serovar israelensis strain 4Q7, a plasmid-cured derivative with higher transformation efficiency than wild types.
Improved Hybrid Genome Assemblies of Two Strains of Bacteroides xylanisolvens, SD_CC_1b and SD_CC_2a, Obtained Using Illumina and 454 Sequencing Technologies
Authors: Ramaraj Thiruvarangan , Sundararajan Anitha , Schilkey Faye D. , DelVecchio Vito G. , Donlon Mildred , Ziemer Cherie , Mudge Joann
Published: April 2014

Bacteroides xlyanisolvens
strains (SD_CC_1b, SD_CC_2a) isolated from human feces were grown on crystalline cellulose. Cellulolytic properties are not common in
Bacteroides
species. Here, we report improved genome sequences of both of the
B. xlyanisolvens
strains.
De Novo
Assembly of the Quorum-Sensing
Pandoraea
sp. Strain RB-44 Complete Genome Sequence Using PacBio Single-Molecule Real-Time Sequencing Technology
Authors: Ee Robson , Lim Yan-Lue , Yin Wai-Fong , Chan Kok-Gan
Published: April 2014

We report the first complete genome sequence of
Pandoraea
sp. strain RB-44, which was found to possess quorum-sensing properties. To the best of our knowledge, this is the first documentation of both a complete genome sequence and quorum-sensing properties of a
Pandoraea
species.
Complete Genome Sequence of a Porcine Circovirus 2 Strain Isolated in Central China
Authors: Guo Guan-Peng , Pan Xin-Long , Cheng Kun , Fu Peng-Fei , Yang Ming-Fan , Chen Hong-Ying
Published: April 2014

We report here the complete genome sequence of the porcine circovirus type 2 (PCV2) XZBK strain, isolated from central China. This is the first report of a member of the 1B subgroup of PCV2b central China. This finding will help in understanding the epidemiology and molecular characteristics of PCV2.
Draft Genome Sequences of
Psychrobacter
Strains JCM 18900, JCM 18901, JCM 18902, and JCM 18903, Isolated Preferentially from Frozen Aquatic Organisms
Authors: Kudo Toshiaki , Kidera Akihiro , Kida Muneaki , Kawauchi Ayumi , Shimizu Ryo , Nakahara Tomomi , Zhang Xiaochi , Yamada Akinori , Amano Masao , Hamada Yuki , Taniyama Shigeto , Arakawa Osamu , Yoshida Asami , Oshima Kenshiro , Suda Wataru , Kuwahara Hirokazu , Nogi Yuichi , Kitamura Keiko , Yuki Masahiro , Iida Toshiya , Moriya Shigeharu , Inoue Tetsushi , Hongoh Yuichi , Hattori Masahira , Ohkuma Moriya
Published: April 2014

Four
Psychrobacter
strains, JCM 18900, JCM 18901, JCM 18902, and JCM 18903, related to either
Psychrobacter nivimaris
or
Psychrobacter cibarius
, were isolated from frozen marine animals. The genome information of these four strains will be useful for studies of their physiology and adaptation properties to frozen conditions.
ST elevation without myocardial infarction
Authors: Bitar Zouheir Ibrahim , Swede Mohammad , Almerri Khaled
Published: April 2014

Acute myocarditis may mimic myocardial infarction because the affected patients report ‘classical’ chest pain; the ECG changes and echocardiography are identical to those observed in acute coronary syndromes, and serum markers are increased. We describe a case with ST segment elevation on admission ECG, and coronary angiography was normal. Cardiac magnetic resonance with myocardial delayed enhancement sequences is a non-invasive alternative for diagnosing myocarditis.
Juvenile dermatomyositis in a Nigerian girl
Authors: Adelowo Olufemi , Nwankwo Madu , Olaosebikan Hakeem
Published: April 2014

Juvenile dermatomyositis is an autoimmune connective tissue disease occurring in children less than 16 years old. It is part of a heterogeneous group of muscle diseases called idiopathic Iiflammatory myopathies. It had previously been reported in black Africans resident in UK. However, there is no documented case reported from Africa. The index sign of heliotrope rashes is often difficult to visualise in the black skin. An 11-year-old Nigerian girl presenting with clinical, laboratory and histopathological features of juvenile dermatomyositis is presented here. It is hoped that this case will heighten the index of suspicion of this condition among medical practitioners in Africa.
Aneurysmal bone cyst of the ethmoid bone
Authors: Janjua Noor , Cresswell Manuela , Sharma Rishi , Maheshwar Arcot
Published: April 2014

A 90-year-old woman presented with headache and diplopia, and a mass in the nasal cavity and paranasal sinuses was found on CT scan. The patient underwent examination under anaesthesia showing a mass arising from the ethmoid, apparently from the nasal septum. Biopsies taken showed an aneurysmal bone cyst. The patient opted against surgery and has been managed conservatively. A second CT scan 4 years later showed significant increase in size.
HELLP syndrome preceded by intrahepatic cholestasis of pregnancy: one serious itch
Authors: Jebbink Jiska , Tabbers Merit , Afink Gijs , Beuers Ulrich , Elferink Ronald Oude , Ris-Stalpers Carrie , van der Post Joris
Published: April 2014

We present four women with seven ongoing pregnancies. Five pregnancies were complicated by intrahepatic cholestasis of pregnancy (ICP) and severe haemolysis, elevated liver enzymes and low platelets (HELLP) syndrome with uncommon maternal morbidity. The combination of ICP and HELLP syndrome has not previously been reported. Awareness is warranted to accurately identify this combination of pregnancy-specific diseases with severe maternal morbidity.
Splenic flexure volvulus in which posture advice was effective
Authors: Ueda Takeshi , Katsurai Takaaki
Published: April 2014

A previously healthy 35-year-old woman suffered from recurrent abdominal pain which had occurred once a week since the age of 23 years. Abdominal CT showed splenic flexure volvulus. Therapeutic colonoscopy was performed successfully, but the frequency of pain attacks remained at once a week. The attacks began after she started to work mainly in a standing position, and never happened while lying down. Therefore, we thought they were induced by forward sigmoid flexure due to gravity. Posture advice, including the knee–chest position and abdominal compression using colonic intraluminal pressure for the resolution of incomplete volvulus during pain attacks, was effective. The severity and frequency of the pain attacks decreased from once a week to once a month. This is the first report of splenic flexure volvulus in which posture advice was effective. Posture advice as a measure to resolve recurrent splenic flexure volvulus should be attempted before surgery.
Bearing capacity and settlement of circular shallow foundations using a nonlinear constitutive relationship
Authors: McMahon B.T. , Haigh S.K. , Bolton M.D.
Published: April 2014

The design of shallow foundations is dominated by issues of settlement rather than bearing capacity per se. The ability to predict the settlement of foundations at a given factor of safety is hence of key importance in design. In this paper, the energy method for a linear-elastic, perfectly plastic method utilizing the von Mises’ yield criterion with associated flow developed and reported by McMahon et al. in 2013 is extended to consider the nonlinear behaviour of soil. The energy method is used to investigate the load–settlement behaviour of shallow foundations by utilizing an ellipsoidal cavity-expansion mechanism and deformation fields within the boundaries of the classical Hill and Prandtl mechanisms. An elastic mechanism obtained from an analysis in ABAQUS was also investigated using this energy method. The upper-bound approach demonstrates that the cavity-expansion mechanism produces a better solution at small values of settlement, whereas at greater settlements the Prandtl mechanism is shown to produce a more optimal upper-bound solution.
Integrating standing value estimations into tree marking guidelines to meet wood supply objectives
Authors: Havreljuk Filip , Achim Alexis , Auty David , Bédard Steve , Pothier David
Published: April 2014

The identification of low-vigor trees with potential for sawlog production is a key objective of tree marking guidelines used for partial cuts in northern hardwoods. The aim of this study was to measure the impact of various vigor-related defects on the monetary value of hardwoods. To achieve this, we sampled 64 sugar maple (Acer saccharum Marshall) and 32 yellow birch (Betula alleghaniensis Britton) trees from two locations in southern Quebec, Canada. We identified over 420 defects, which were grouped into 8 categories. The trees were then harvested and processed into lumber, and the value per unit volume of each stem was calculated from the value of the product assortment (lumber, chips, and sawdust). We found that visible evidence of fungal infections (sporocarps and (or) stroma) and cracks had the largest negative influence on value in both species. A model that included these defects was almost as good at predicting value as one that included a specifically designed quality classification. A more accurate assessment of value could be achieved using wood decay assessment tools and (or) by considering site-specific variables. Results from this study showed that visual identification of fungal infections and cracks could be used to enhance tree marking guidelines for hardwoods. This would meet both the silvicultural objective of selection cuts, by removing low-vigor trees, and the wood supply objective, by improving stem quality assessment prior to harvest.
Design-based treatment of missing data in forest inventories using canopy heights from aerial laser scanning
Authors: Corona Piermaria , Chirici Gherardo , Franceschi Sara , Maffei Daniela , Marcheselli Marzia , Pisani Caterina , Fattorini Lorenzo
Published: April 2014

Nonresponse is often a problem in forest inventories. It may arise when sample plots are inaccessible because of hazardous terrain. To account for this problem, the use of nonresponse calibration weighting is considered in a complete design-based framework, i.e., both nonresponse and survey variables are viewed as fixed characteristics of the plots. Information derived from remotely sensed data is exploited to compensate for the missing plots. Calibration is performed adopting canopy height from airborne laser scanning as an auxiliary variable. Conditions for approximate unbiasedness of the calibration estimator in two-phase inventories are derived, and some estimators of the sampling variance are proposed. Results from one-phase inventories are achieved as a particular case. Dummy variables are introduced in the presence of different forest types. Monte Carlo results support the validity of the procedure. An application to a forest survey carried out in Central Italy is performed.
Obtaining multiwalled and single-walled carbon nanotubes and nanocomposites
Authors: Abdullin Khabibulla A. , Batryshev Didar G. , Chihray Eugene V. , Gabdullin Maratbek T. , Ismailov Daniyar V. , Kim Bog G. , Togambaeva Altynay K.
Published: April 2014

In this paper we considered three methods of carbon nanotube (CNT) synthesis: chemical vapor deposition in a fixed and fluidized bed rector, and pyrolysis of nebulized solutions of ferrocene in carbon precursor solvents. The latter method has a high CNT yield and allows multiwalled (MWCNTs) as well as single-walled nanotubes (SWCNTs) to be obtained. The samples were analyzed by scanning electron microscopy and Raman spectroscopy. The optimal technological conditions giving a maximum yield of CNTs were studied. A CNT–copper composite was obtained by electroplating or by electroless Cu deposition on the SWCNT layer. MWCNTs were grown on silica fibers and electrical properties of the composite were measured. It was found that electrical resistance of the composite is pressure dependent and its conductivity can be easily varied changing the conditions of synthesis.
Perturbations of Keplerian orbits in stationary spherically symmetric spacetimes
Authors: Ruggiero Matteo Luca
Published: April 2014

We study spherically symmetric perturbations determined by alternative theories of gravity to the gravitational field of a central mass in General Relativity (GR). In particular, we focus on perturbations in the form of power laws and calculate their effect on the secular variations of the orbital elements of a Keplerian orbit. We show that, to lowest approximation order, only the argument of pericenter and mean anomaly undergo secular variations; furthermore, we calculate the variation of the orbital period. We give analytic expressions for these variations which can be used to constrain the impact of alternative theories of gravity.
Effective Cooperations Through Non-Monetary Exchanges: A Computational Framework
Authors: Rodrigues Maíra R. , Luck Michael
Published: April 2014

Today there is an increase in the number of cooperative initiatives in different domains to make tools and data available to global communities free or charge. Such cooperative systems are open, heterogeneous, dynamic, and lack a formal payment system. Incentivising cooperation in these scenarios is essential to maintain their effectiveness. Therefore, there is a recognised need to move away from an ad hoc approach to one in which cooperation is supported and encouraged. The agent-oriented paradigm has been advocated as a natural way to design and implement systems that are distributed and heterogeneous. However, developing an agent-oriented system for today's cooperative systems is challenging. It requires a means not only to provide non-monetary incentives for service providers, but also to consider the level of quality of cooperations, in terms of the quality of provided and received services. In this context, the key contribution of this paper is a framework for non-monetary interactions among self-interested agents, in which the motivation to cooperate and the bases for analysing cooperations come from Piaget's theory of exchange values. Our framework includes a computational model of these values, which defines how exchange values are accumulated and spent by interacting agents. We illustrate how our framework can be used by agents to analyze cooperations and to take decisions about them, and provide an empirical evaluation.
SYNTHESIS AND CHARACTERISATION OF ELECTROSPUN CHITOSAN MEMBRANES REINFORCED BY HALLOYSITE NANOTUBES
Authors: GOVINDASAMY K. , FERNANDOPULLE C. , PASBAKHSH POORIA , GOH K. L.
Published: April 2014

We report on the electrospinning method to synthesize and characterise chitosan membranes reinforced by halloysite nanotubes (HNTs). The synthesis process addressed two levels of HNTs concentration, i.e., 2 and 5 wt.%. Tensile testing was carried out to determine the strength (σ), strain (ε) at σ and elastic modulus (E) of the membranes. Tensile test data revealed that the membranes reinforced with 5 wt.% HNTs yielded the highest E (0.153 ± 0.02 GPa) and strength (22.53 ± 8.57 MPa). Electron micrographs of the fractured surfaces showed uniform dispersions of HNTs in the chitosan matrix. Infrared spectra indicated interactions between chitosan and inner and outer surfaces of HNTs. Thermogravimetric analysis demonstrated an increase in thermal stability with the addition of HNTs. Membranes immersed in simulated body fluid system for 28 days revealed the formation of dense apatite blocks with the addition of HNTs. Surface roughness increased with the addition of HNTs resulted a rise in degree of contact angle.
METHOD OF FUNDAMENTAL SOLUTIONS FOR NONLINEAR SKIN BIOHEAT MODEL
Authors: ZHANG ZE-WEI , WANG HUI , QIN QING-HUA
Published: April 2014

In this paper, the method of fundamental solution (MFS) coupling with the dual reciprocity method (DRM) is developed to solve nonlinear steady state bioheat transfer problems. A two-dimensional nonlinear skin model with temperature-dependent blood perfusion rate is studied. Firstly, the original bioheat transfer governing equation with nonlinear term induced by temperature-dependent blood perfusion rate is linearized with the Taylor's expansion technique. Then, the linearized governing equation with specified boundary conditions is solved using a meshless approach, in which the DRM and the MFS are employed to obtain particular and homogeneous solutions, respectively. Several numerical examples involving linear, quadratic and exponential relations between temperature and blood perfusion rate are tested to verify the efficiency and accuracy of the proposed meshless model in solving nonlinear steady state bioheat transfer problems, and also the sensitivity of coefficients in the expression of temperature-dependent blood perfusion rate is analyzed for investigating the influence of blood perfusion rate to temperature distribution in skin tissues.
HOW PRODUCT, OPERATIONS, AND MARKETING SOURCES OF IDEAS INFLUENCE INNOVATION AND ENTREPRENEURIAL PERFORMANCE IN AUSTRALIAN SMEs
Authors: DE ZUBIELQUI GRACIELA CORRAL , LINDSAY NOEL J. , O'CONNOR ALLAN
Published: April 2014

In this paper we have used structural equation modelling to examine the inter-relationships among specific intangible resources — product, operations, and marketing sources of ideas — as they relate to innovation and firm performance. Prior studies founded upon the Resource Based View (RBV) of the firm, have focused on the relationship between innovation and firm performance or resources and firm performance, but have not examined both simultaneously. Our study reveals how the sources of ideas, as valuable strategic firm resources, directly, and/or indirectly via innovation activities, contribute to firm performance. We find that marketing sources of ideas directly influences firm performance and that product and operations sources of ideas do not. Indirectly, however, all three sources of idea resources (marketing, operational, and product) contribute to firm performance via the innovation construct. Thus, ideas, and where they come from, are crucial to understanding innovation and firm performance. Innovation is a key component in the structural model because it partially mediates the marketing idea sources-performance relationship. It also provides the basis for interaction effects among operations and product resources and firm performance. Therefore, including innovation in the conceptual model improves the model specification as it increases insight into the resource-performance relationship.
MODULATING CH3NH3PbI3 PEROVSKITE CRYSTALLIZATION BEHAVIOR THROUGH PRECURSOR CONCENTRATION
Authors: FU KUNWU , LIM SWEE SIEN , FANG YANAN , BOIX PABLO P. , MATHEWS NRIPAN , SUM TZE CHIEN , WONG LYDIA H. , MHAISALKAR SUBODH
Published: April 2014

Perovskite-based photovoltaic devices have recently achieved impressively high efficiencies beyond 15% and gained great interest. We show here the formation of perovskite cluster overlayer structures which consist of individual perovskite grains on top of mesoporous TiO 2 films, coexisting with the randomly distributed nanocrystals within the films. Perovskite solution concentration was found to play an important role in modulating the perovskite crystallization and cluster overlayer formation process. Absorbance increase in visible wavelength range and shift of photoluminescence (PL) responses of perovskite films due to the effect of precursor concentration change were observed and investigated in detail. The crystallographic analysis of the CH 3 NH 3 PbI 3 films shows a gradual decrease of the perovskite lattice parameters and shrinkage of unit volume as precursor solution concentration increases, which is correlated to the changes of optical properties. Finally, perovskite-based solar cell device performance was enhanced at higher precursor concentration.
On the complexity of average path length for biological networks and patterns
Authors: Asif Waqar , Qureshi Hassaan Khaliq , Iqbal Adnan , Rajarajan Muttukrishnan
Published: April 2014

Path length calculation is a frequent requirement in studies related to graph theoretic problems such as genetics. Standard method to calculate average path length (APL) of a graph requires traversing all nodes in the graph repeatedly, which is computationally expensive for graphs containing large number of nodes. We propose a novel method to calculate APL for graphs commonly required in the studies of genetics. The proposed method is computationally less expensive and less time-consuming compared to standard method.
On the cohomology of weakly almost periodic group representations
Authors: Bader Uri , Rosendal Christian , Sauer Roman
Published: April 2014

We initiate a study of cohomological aspects of weakly almost periodic group representations on Banach spaces, in particular, isometric representations on reflexive Banach spaces. Using the Ryll–Nardzewski fixed point theorem, we prove a vanishing result for the restriction map (with respect to a subgroup) in the reduced cohomology of weakly periodic representations. Combined with the Alaoglu–Birkhoff decomposition theorem, this generalizes and complements theorems on continuous group cohomology by several authors.
Correlation of the nappe stack in the Ibero-Armorican arc across the Bay of Biscay: a joint French–Spanish project
Authors: Ballèvre Michel , Martínez Catalán José R. , López-Carmona Alicia , Pitra Pavel , Abati Jacobo , Fernández Rubén Díez , Ducassou Céline , Arenas Ricardo , Bosse Valérie , Castiñeiras Pedro , Fernández-Suárez Javier , Gómez Barreiro Juan , Paquette Jean-Louis , Peucat Jean-Jacques , Poujol Marc , Ruffet Gilles , Sánchez Martínez Sonia
Published: April 2014

A correlation between allochthonous units exposed in the NW Iberian Massif and the southern Armorican Massif is carried out based on lithological associations, structural position, age and geochemistry of protoliths and tectonometamorphic evolution. The units on both sides of the Bay of Biscay are grouped into Upper, Middle and Lower allochthons, whereas an underlying allochthonous thrust sheet identified in both massifs is referred to as the Parautochthon. The Lower Allochthon represents a fragment of the outermost edge of Gondwana that underwent continental subduction shortly after the closure of a Palaeozoic ocean which, in turn, is represented by the Middle Allochthon. The latter consists of supra-subduction ophiolites and metasedimentary sequences alternating with basic, mid-ocean ridge basalt (MORB)-type volcanics, with inheritances suggesting the proximity of a continental domain. Seafloor spreading began at the Cambro-Ordovician boundary and oceanic crust was still formed during the Late Devonian, covering the lifetime of the Rheic Ocean, which is possibly represented by the Middle Allochthon. The opening of the oceanic domain was related to pulling apart the peri-Gondwanan continental magmatic arc, which is represented by the Upper Allochthon.
Fun and Games in Berkeley: The Early Years (1956–2013)
Authors: Tinoco Ignacio
Published: April 2014

Life at Berkeley for the past 57 years involved research on the thermodynamics, kinetics, and spectroscopic properties of RNA to better understand its structures, interactions, and functions. We (myself and all the graduate students and postdocs who shared in the fun) began with dinucleoside phosphates and slowly worked our way up to megadalton-sized RNA molecular motors. We used UV absorption, circular dichroism, circular intensity differential scattering, fluorescence, NMR, and single-molecule methods. We learned a lot and had fun doing it.
Progress and Challenges in Control of Chemical Processes
Authors: Lee Jay H. , Lee Jong Min
Published: April 2014

This review covers key developments and trends in chemical process control during the past two decades. Control methodologies and related supporting technologies are covered, and recent trends in applications are also examined. After the widespread adoption of model-based techniques by industry, control interest has begun to move beyond the traditional realm of readily measured variables to include chemical compositions and particle features. However, the shift is being slowed by the shortage of accurate, reliable, and inexpensive sensing devices. Although the past two decades saw no new major theoretical or methodological advances, several important incremental improvements and extensions have been made to help the ripening of the technologies developed in the preceding two decades. Control is regaining its importance owing to society's renewed focus on energy and the maturation of various emerging technologies, but a community-wide consensus on what general problems should be solved is lacking.
Downhole Fluid Analysis and Asphaltene Science for Petroleum Reservoir Evaluation
Authors: Mullins Oliver C. , Pomerantz Andrew E. , Zuo Julian Y. , Dong Chengli
Published: April 2014

Petroleum reservoirs are enshrouded in mysteries associated with all manner of geologic and fluid complexities that Mother Nature can inspire. Efficient exploitation of petroleum reservoirs mandates elucidation of these complexities; downhole fluid analysis (DFA) has proven to be indispensable for understanding both fluids and reservoir architecture. Crude oil consists of dissolved gases, liquids, and dissolved solids, known as the asphaltenes. These different fluid components exhibit fluid gradients vertically and laterally, which are best revealed by DFA, with its excellent precision and accuracy. Compositional gradient analysis falls within the purview of thermodynamics. Gas-liquid equilibria can be treated with a cubic equation of state (EoS), such as the Peng-Robinson EoS, a modified van der Waals EoS. In contrast, the first EoS for asphaltene gradients, the Flory-Huggins-Zuo (FHZ) EoS, was developed only recently. The resolution of the asphaltene molecular and nanocolloidal species in crude oil, which is codified in the Yen-Mullins model of asphaltenes, enabled the development of this EoS. The combination of DFA characterization of gradients of reservoir crude oil with the cubic EoS and FHZ EoS analyses brings into view wide-ranging reservoir concerns, such as reservoir connectivity, fault-block migration, heavy oil gradients, tar mat formation, huge disequilibrium fluid gradients, and even stochastic variations of reservoir fluids. New petroleum science and DFA technology are helping to offset the increasing costs and technical difficulties of exploiting ever-more-remote petroleum reservoirs.
Electrochemical Energy Engineering: A New Frontier of Chemical Engineering Innovation
Authors: Gu Shuang , Xu Bingjun , Yan Yushan
Published: April 2014

One of the grand challenges facing humanity today is a safe, clean, and sustainable energy system where combustion no longer dominates. This review proposes that electrochemical energy conversion could set the foundation for such an energy system. It further suggests that a simple switch from an acid to a base membrane coupled with innovative cell designs may lead to a new era of affordable electrochemical devices, including fuel cells, electrolyzers, solar hydrogen generators, and redox flow batteries, for which recent progress is discussed using the authors' work as examples. It also notes that electrochemical energy engineering will likely become a vibrant subdiscipline of chemical engineering and a fertile ground for chemical engineering innovation. To realize this vision, it is necessary to incorporate fundamental electrochemistry and electrochemical engineering principles into the chemical engineering curriculum.
Limitations of Certification and Supply Chain Standards for Environmental Protection in Commodity Crop Production
Authors: Waldman Kurt B. , Kerr John M.
Published: April 2014

Motivated by recent increases in water pollution in major US agricultural watersheds and by the shortcomings of government programs to control non–point source pollution, this paper examines the prospects for using product certification (ecolabeling) and business-to-business supply chain standards for environmental protection in commodity crop production. We introduce the sources of demand for certification and supply chain standards and the political and economic context in which they have expanded since the 1990s. We explore how various agrifood certification and supply chain standards have been used to achieve changes in production methods and/or in product attributes to meet social goals, and we discuss the prospects for applying these models to commodity crops. We conclude that the nature of corn and soybean production, distribution, and consumption—with numerous sales outlets and invisible consumption as part of processed foods and other products—makes certification schemes to limit agricultural pollution unrealistic and supply chain standards extremely challenging.
(Invited) Holistic View on Chemical Processes in Li-O2 Battery from Operando Spatiotemporal Study
Authors: Shui Jianglan , Okasinski John , Kenesei Peter , Almer Jon , Liu Di-Jia
Published: April 2014

Li-O2 battery has drawn an increasing interests due to its potential for the future energy storage in transportation application. At present, the understanding on the electrochemical processes at individual region (anode, cathode and separator) and their interdependence are still limited due to convoluted reactions. In this report, we will discuss our recent spatiotemporal investigation on the operating Li-O2 batteries under the cycling condition using the most representative design and materials in the field. We were able not only to reveal individually the changes at anode, cathode and separator, but also to assemble these data under the same discharge-charge time domain. Such information provides a holistic view of the chemical processes at different regions and their interdependence inside of a working battery.
Electrochemical Properties of NaCuO2 for Sodium-Ion Secondary Batteries
Authors: Ono Yoko , Yui Yuhki , Hayashi Masahiko , Asakura Kaoru , Kitabayashi Hiroto , Takahashi Kazue I.
Published: April 2014

Charge-discharge properties of NaCuO2 as a positive electrode were evaluated for sodium-ion secondary batteries in two voltage ranges. When the test was started with the discharge process in the voltage range of 0.75 to 3.0 V, about 0.6 mol/0.6 mol of sodium ions were inserted/extracted from NaCuO2 during the first discharge/charge process (The capacities were 140 and 141 mAh/g). On the other hand, when the test was started with the charge process in the voltage range of 1.7 – 4.2 V, about 0.6mol /0.2 mol of sodium ions were extracted/inserted to NaCuO2 in the first process (The capacities were 134 and 55 mAh/g). These amounts are almost in agreement with the analytical values. The results suggest that NaCuO2 has a potential to be used as a positive electrode material for sodium-ion secondary batteries.
In Situ XRD Study of the Phase Evolution in LixMn1.5Ni0.5O4 as 4.7-Volt Positive Electrode Materials for Li-Ion Batteries
Authors: Zhu Wen , Liu Dong , Trottier Julie , Hovington Pierre , Gagnon Catherine , Guerfi Abdelbast , Zaghib Karim , Mauger Alain , Groult Henri , Julien Christian M
Published: April 2014

In situ X-ray diffraction has been carried out to study the structural changes of the bare and Cr-doped LiMn1.5Ni0.5O4 crystallized samples in the disordered phase (Fd

m space group) are investigated during the galvanostatic charge/discharge process at C/24 rate. The de-intercalation of lithium proceeds through a series of first-order phase transitions with two regions of two-phase coexistence. The phase diagram is analyzed and discussed, together with the differences among different results reported in the literature.
Bulk and Surface Modification of LiMn1.5Ni0.5O4 as 4.7-Volt Positive Electrode Material for Li-Ion Batteries
Authors: Liu Dong , Hamel-Paquet J , Trottier Julie , Barray F , Gariépy Vincent , Gagnon Catherine , Hovington Pierre , Guerfi Abdelbast , Zaghib Karim , Mauger Alain , Groult Henri , Julien Christian M
Published: April 2014

Lithium-insertion compounds with the spinel structure become active element of a new generation of Li-ion batteries, namely the 4.7-V positive electrodes that improve the technologies of energy storage and electric transportation. The compound considered here is the bulk and surface modified LiMn1.5Ni0.5O4 (LMN) spinel. We report the structural and electrochemical features of Cr-doped LMN phase and the LiFePO4-coated LMN structure. Emphasis is placed on the control of physical properties that is needed to guarantee the reliability and the optimum electrochemical performance of these materials.
Effect of the Carbonization on the LiFePO4 Particles of Positive Electrode for Rechargeable Lithium Batteries
Authors: Gariépy Vincent , Vediappan Kumaran , Hovington Pierre , Trottier Julie , Gagnon Catherine , Barray F , Guerfi Abdelbast , Zaghib Karim , Mauger Alain , Groult Henri , Julien Christian M
Published: April 2014

In addition of the poor intrinsic conductivity of LiFePO4 particle, surface effects become increasingly important, and can eventually dominate the physical and the chemical properties when the size decreases below 100 nm. Carbon coating appeared to overcome the drawback of highly resistive LiFePO4 powders and to cure the disordered surface layer that reduces the electrochemical performance of non-coated sample. Here, we analyze the effect of the carbon coating on the LiFePO4 particles that meets a worldwide success as a positive electrode for commercial Li-ion batteries.
Negative Capacitance Tunnel Field Effect Transistor: A Novel Device with Low Subthreshold Swing and High on Current
Authors: Chowdhury Nadim , Azad S. M. Farhaduzzaman , Khosru Quazi D. M.
Published: April 2014

In this paper we propose a modiﬁed structure of TFET incorporating ferroelectric oxide as the complementary gate dielectric operating in negative capacitance zone, called the Negative Capacitance Tunnel FET (NCTFET). The proposed device effectively combines two different mechanisms of lowering the sub threshold swing (SS) for a transistor garnering a further lowered one compared to conventional TFET. A simple yet accurate analytical tunnel current model for the proposed device is also presented here. The developed analytical model demonstrates high ON current at low VGS and exhibits lower SS.