bluuebunny/crossref_metadata_2025 huggingface dataset:
Improved Peripheral Nerve Regeneration in Streptozotocin-Induced Diabetic Rats by Oral Lumbrokinase
Authors: Lee Han-Chung , Hsu Yuan-Man , Tsai Chin-Chuan , Ke Cherng-Jyh , Yao Chun-Hsu , Chen Yueh-Sheng
Published: March 2015

We assessed the therapeutic effects of lumbrokinase, a group of enzymes extracted from the earthworm, on peripheral-nerve regeneration using well-defined sciatic nerve lesion paradigms in diabetic rats induced by the injection of streptozotocin (STZ). We found that lumbrokinase therapy could improve the rats' circulatory blood flow and promote the regeneration of axons in a silicone rubber conduit after nerve transection. Lumbrokinase treatment could also improve the neuromuscular functions with better nerve conductive performances. Immunohistochemical staining showed that lumbrokinase could dramatically promote calcitonin gene-related peptide (CGRP) expression in the lamina I–II regions in the dorsal horn ipsilateral to the injury and cause a marked increase in the number of macrophages recruited within the distal nerve stumps. In addition, the lumbrokinase could stimulate the secretion of interleukin-1 (IL-1), nerve growth factor (NGF), platelet-derived growth factor (PDGF), and transforming growth factor-β (TGF-β) in dissected diabetic sciatic nerve segments. In conclusion, the administration of lumbrokinase after nerve repair surgery in diabetic rats was found to have remarkable effects on promoting peripheral nerve regeneration and functional recovery.
Anti-Oxidative and Anti-Inflammatory Effects of Lobelia chinensis In Vitro and In Vivo
Authors: Li Kun-Cheng , Ho Yu-Ling , Huang Guan-Jhong , Chang Yuan-Shiun
Published: March 2015

Lobelia chinensis Lour (LcL) is a popular herb that has been widely used as folk medicine in China for the treatment of fever, lung cancer, and inflammation for hundreds of years. Recently, several studies have shown that the anti-inflammatory properties were correlated with the inhibition of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) from the NF-κB pathway. The aim of this study was to evaluate the anti-oxidative and anti-inflammatory activities of L. chinensis. Both suppressive activities on LPS-induced nitric oxide production in RAW264.7 macrophages in vitro and the acute rat lung injury model in vivo were studied. The results showed that the methanol extract of LcL and its fractions within the range of 62.5–250 μg/mL did not induce cytotoxicity (p < 0.001). The ethyl acetate fraction of LcL showed better NO inhibition activity than other fractions. On the other hand, the Lc-EA (62.5, 125, 250 mg/kg) pretreated rats showed a decrease in the pro-inflammatory cytokines (TNF-α, IL-β, IL-6) and inhibited iNOS, COX-2 expression through the NF-κB pathway. These results suggested that L. chinensis exhibited an anti-inflammatory effect through the NF-κB pathways.
Toward understanding tautomeric switching in 4-hydroxynaphthaldehyde and its dimers: A DFT and quantum topology study
Authors: El-Amri Aeshah , Elroby Shaaban A. , Kühn Oliver , Hilal Rifaat H.
Published: March 2015

The electronic structures and stabilities of all benzenoid (enol) and quinonoid (keto) forms of 4-hydroxynaphthaldehyde (ALD-14) have been investigated using density functional theory (DFT) with a range of functionals and basis sets. The anti-enol form represents the global minimum energy structure. Low rotation barriers of both the hydroxyl and the aldehyde groups characterize this form. Fourier analysis of the potential energy function for rotation indicate that the conformational preference of ALD-14 is determined by both the dipole–dipole repulsion and bond moments interactions. Further, three different ALD-14 dimer complexes are investigated, i.e. head-to-tail (HT), head-to-head (HH), and stacked (S) forms. The analysis of natural bond order, quantum topology features of the Laplacian of the electron density, binding energies and structural parameters of these dimers point to comparable stabilities of the HT and S-dimers, with a preference for a stacking contact. The origin of its stability can be traced to π-conjugative, H-bonding and dispersion interactions.
Task-Based Information Interaction Evaluation
Authors: Järvelin Kalervo , Vakkari Pertti , Arvola Paavo , Baskaya Feza , Järvelin Anni , Kekäläinen Jaana , Keskustalo Heikki , Kumpulainen Sanna , Saastamoinen Miamaria , Savolainen Reijo , Sormunen Eero
Published: March 2015

Evaluation is central in research and development of information retrieval (IR). In addition to designing and implementing new retrieval mechanisms, one must also show through rigorous evaluation that they are effective. A major focus in IR is IR mechanisms’ capability of ranking relevant documents optimally for the users, given a query. Searching for information in practice involves searchers, however, and is highly interactive. When human searchers have been incorporated in evaluation studies, the results have often suggested that better ranking does not necessarily lead to better search task, or work task, performance. Therefore, it is not clear which system or interface features should be developed to improve the effectiveness of human task performance. In the present article, we focus on the evaluation of task-based information interaction (TBII). We give special emphasis to learning tasks to discuss TBII in more concrete terms. Information interaction is here understood as behavioral and cognitive activities related to task planning, searching information items, selecting between them, working with them, and synthesizing and reporting. These five generic activities contribute to task performance and outcome and can be supported by information systems. In an attempt toward task-based evaluation, we introduce program theory as the evaluation framework. Such evaluation can investigate whether a program consisting of TBII activities and tools works and how it works and, further, provides a causal description of program (in)effectiveness. Our goal in the present article is to structure TBII on the basis of the five generic activities and consider the evaluation of each activity using the program theory framework. Finally, we combine these activity-based program theories in an overall evaluation framework for TBII. Such an evaluation is complex due to the large number of factors affecting information interaction. Instead of presenting tested program theories, we illustrate how the evaluation of TBII should be accomplished using the program theory framework in the evaluation of systems and behaviors, and their interactions, comprehensively in context.
Visual Enhancement of MR Angiography Images to Facilitate Planning of Arteriovenous Malformation Interventions
Authors: Abhari Kamyar , Baxter John S. H. , Khan Ali R. , Peters Terry M. , Ribaupierre Sandrine De , Eagleson Roy
Published: March 2015

The primary purpose of medical image visualization is to improve patient outcomes by facilitating the inspection, analysis, and interpretation of patient data. This is only possible if the users’ perceptual and cognitive limitations are taken into account during every step of design, implementation, and evaluation of interactive displays. Visualization of medical images, if executed effectively and efficiently, can empower physicians to explore patient data rapidly and accurately with minimal cognitive effort. This article describes a specific case study in biomedical visualization system design and evaluation, which is the visualization of MR angiography images for planning arteriovenous malformation (AVM) interventions. The success of an AVM intervention greatly depends on the surgeon gaining a full understanding of the anatomy of the malformation and its surrounding structures. Accordingly, the purpose of this study was to investigate the usability of visualization modalities involving contour enhancement and stereopsis in the identification and localization of vascular structures using objective user studies. Our preliminary results indicate that contour enhancement, particularly when combined with stereopsis, results in improved performance enhancement of the perception of connectivity and relative depth between different structures.
Adrenal fasciculata cells express T-type and rapidly and slowly activating L-type Ca2+ channels that regulate cortisol secretion
Authors: Enyeart John J. , Enyeart Judith A.
Published: March 2015

In whole cell patch-clamp recordings, we characterized the L-type Ca2+ currents in bovine adrenal zona fasciculata (AZF) cells and explored their role, along with the role of T-type channels, in ACTH- and angiotensin II (ANG II)-stimulated cortisol secretion. Two distinct dihydropyridine-sensitive L-type currents were identified, both of which were activated at relatively hyperpolarized potentials. One activated with rapid kinetics and, in conjunction with Northern blotting and PCR, was determined to be Cav1.3. The other, expressed in approximately one-half of AZF cells, activated with extremely slow voltage-dependent kinetics and combined properties not previously reported for an L-type Ca2+ channel. The T-type Ca2+ channel antagonist 3,5-dichloro- N-[1-(2,2-dimethyl-tetrahydro-pyran-4-ylmethyl)-4-fluoro-piperidin-4-ylmethyl]-benzamide (TTA-P2) inhibited Cav3.2 current in these cells, as well as ACTH- and ANG II-stimulated cortisol secretion, at concentrations that did not affect L-type currents. In contrast, nifedipine specifically inhibited L-type currents and cortisol secretion, but less effectively than TTA-P2. Diphenylbutylpiperidine Ca2+ antagonists, including pimozide, penfluridol, and fluspirilene, and the dihydropyridine niguldipine blocked Cav3.2 and L-type currents and inhibited ACTH-stimulated cortisol secretion with similar potency. This study shows that bovine AZF cells express three Ca2+ channels, the voltage-dependent gating and kinetics of which could orchestrate complex mechanisms linking peptide hormone receptors to cortisol secretion through action potentials or sustained depolarization. The function of the novel, slowly activating L-type channel is of particular interest in this respect. Regardless, the well-correlated selective inhibition of T- and L-type currents and ACTH- and ANG II-stimulated cortisol secretion by TTA-P2 and nifedipine establish the critical importance of these channels in AZF cell physiology.
Macrophage deficiency in osteopetrotic (op/op) mice inhibits activation of satellite cells and prevents hypertrophy in single soleus fibers
Authors: Ohira T. , Wang X. D. , Ito T. , Kawano F. , Goto K. , Izawa T. , Ohno H. , Kizaki T. , Ohira Y.
Published: March 2015

Effects of macrophage on the responses of soleus fiber size to hind limb unloading and reloading were studied in osteopetrotic homozygous ( op/ op) mice with inactivated mutation of macrophage colony-stimulating factor (M-CSF) gene and in wild-type (+/+) and heterozygous (+/ op) mice. The basal levels of mitotically active and quiescent satellite cell (−46 and −39% vs. +/+, and −40 and −30% vs. +/ op) and myonuclear number (−29% vs. +/+ and −28% vs. +/ op) in fibers of op/ op mice were significantly less than controls. Fiber length and sarcomere number in op/ op were also less than +/+ (−22%) and +/ op (−21%) mice. Similar trend was noted in fiber cross-sectional area (CSA, −15% vs. +/+, P = 0.06, and −14% vs. +/ op, P = 0.07). The sizes of myonuclear domain, cytoplasmic volume per myonucleus, were identical in all types of mice. The CSA, length, and the whole number of sarcomeres, myonuclei, and mitotically active and quiescent satellite cells, as well as myonuclear domain, in single muscle fibers were decreased after 10 days of unloading in all types of mice, although all of these parameters in +/+ and +/ op mice were increased toward the control values after 10 days of reloading. However, none of these levels in op/ op mice were recovered. Data suggest that M-CSF and/or macrophages are important to activate satellite cells, which cause increase of myonuclear number during fiber hypertrophy. However, it is unclear why their responses to general growth and reloading after unloading are different.
Impairment of hepatic nuclear factor-4α binding to theStim1promoter contributes to high glucose-induced upregulation of STIM1 expression in glomerular mesangial cells
Authors: Wang Yanxia , Chaudhari Sarika , Ren Yuezhong , Ma Rong
Published: March 2015

The present study was carried out to investigate if hepatic nuclear factor (HNF)4α contributed to the high glucose-induced increase in stromal interacting molecule (STIM)1 protein abundance in glomerular mesangial cells (MCs). Western blot and immunofluorescence experiments showed HNF4α expression in MCs. Knockdown of HNF4α using a small interfering RNA approach significantly increased mRNA expression levels of both STIM1 and Orai1 and protein expression levels of STIM1 in cultured human MCs. Consistently, overexpression of HNF4α reduced expressed STIM1 protein expression in human embryonic kidney-293 cells. Furthermore, high glucose treatment did not significantly change the abundance of HNF4α protein in MCs but significantly attenuated HNF4α binding activity to the Stim1 promoter. Moreover, knockdown of HNF4α significantly augmented store-operated Ca2+entry, which is known to be gated by STIM1 and has recently been found to be antifibrotic in MCs. In agreement with those results, knockdown of HNF4α significantly attenuated the fibrotic response of high glucose. These results suggest that HNF4α negatively regulates STIM1 transcription in MCs. High glucose increases STIM1 expression levels by impairing HNF4α binding activity to the Stim1 promoter, which subsequently releases Stim1 transcription from HNF4α repression. Since the STIM1-gated store-operated Ca2+entry pathway in MCs has an antifibrotic effect, inhibition of HNF4α in MCs might be a potential therapeutic option for diabetic kidney disease.
Neurosteroids increase tonic GABAergic inhibition in the lateral section of the central amygdala in mice
Authors: Romo-Parra H. , Blaesse P. , Sosulina L. , Pape H.-C.
Published: March 2015

Neurosteroids are formed de novo in the brain and can modulate both inhibitory and excitatory neurotransmission. Recent evidence suggests that the anxiolytic effects of neurosteroids are mediated by the amygdala, a key structure for emotional and cognitive behaviors. Tonic inhibitory signaling via extrasynaptic type A γ-aminobutyric acid receptors (GABAARs) is known to be crucially involved in regulating network activity in various brain regions including subdivisions of the amygdala. Here we provide evidence for the existence of tonic GABAergic inhibition generated by the activation of δ-subunit-containing GABAARs in neurons of the lateral section of the mouse central amygdala (CeAl). Furthermore, we show that neurosteroids play an important role in the modulation of tonic GABAergic inhibition in the CeAl. Taken together, these findings provide new mechanistic insights into the effects of pharmacologically relevant neurosteroids in the amygdala and might be extrapolated to the regulation of anxiety.
Population coding in area V4 during rapid shape detections
Authors: Weiner Katherine F. , Ghose Geoffrey M.
Published: March 2015

While previous studies have suggested that neuronal correlations are common in visual cortex over a range of timescales, the effect of correlations on rapid visually based decisions has received little attention. We trained Macaca mulatta to saccade to a peripherally presented shape embedded in dynamic noise as soon as the shape appeared. While the monkeys performed the task, we recorded from neuronal populations (5–29 cells) using a microelectrode array implanted in area V4, a visual area thought to be involved in form perception. While modest correlations were present between cells during visual stimulation, their magnitude did not change significantly subsequent to the appearance of a shape. We quantified the reliability and temporal precision with which neuronal populations signaled the appearance of the shape and predicted the animals' choices using mutual information analyses. To study the impact of correlations, we shuffled the activity from each cell across observations while retaining stimulus-dependent modulations in firing rate. We found that removing correlations by shuffling across trials minimally affected the reliability or timing with which pairs, or larger groups of cells, signaled the presence of a shape. To assess the downstream impact of correlations, we also studied how shuffling affected the ability of V4 populations to predict behavioral choices. Surprisingly, shuffling created a modest increase in the accuracy of such predictions, suggesting that the reliability of downstream neurons is slightly compromised by activity correlations. Our findings are consistent with neuronal correlations having a minimal effect on the reliability and timing of rapid perceptual decisions.
A Micro-TEHL Finite Line Contact Model for a Helical Gear Pair
Authors: Liu Mingyong , Zhu Caichao , Liu Huaiju
Published: March 2015

A micro-TEHL finite line contact model for a helical gear pair is developed by considering sinusoidal waviness on tooth surfaces. Effects of working conditions, the amplitude, and the wavelength of the waviness roughness on the lubrication performance are studied. Results show that surface roughness has a significant influence on the pressure, the temperature, and so forth. The pressure within the nominal contact zone for a rough-surface case fluctuates around the smooth-surface solution. For the working conditions studied, at local area within the contact zone, the maximum pressure may be 50% higher than the smooth-surface result. The film contraction at the outlet zone becomes more remarkable. The film temperature also fluctuates regularly. As the amplitude of the roughness increases, the local pressure within the nominal contact zone increases while the minimum film thickness decreases. As the wavelength of the roughness decreases, the local pressure and the temperature within the nominal contact zone increase while the film thickness decreases. Effect of wavelength on the lubrication performance is more evident along the rolling speed direction than along the contact line direction.
Effects of Solidity Ratio on Performance of OWC Impulse Turbine
Authors: Cui Ying , Liu Zhen
Published: March 2015

Oscillating water column (OWC) wave energy converters, which are capable of extracting power from ocean waves, have been constructed and adopted worldwide. An essential component of an OWC system is the impulse turbine, which plays a significant role in converting the energy of bidirectional airflow into mechanical shaft power. To optimize the starting characteristics and conversion efficiencies of impulse turbines, a considerable number of studies have been conducted to improve their geometric construction. This paper verifies a numerical model established in FLUENT 14.5 with preexisting experimental data and subsequently explores the effects of the solidity ratio on turbine performance. The results show that the coherence between computed and measured data is satisfactory. In addition, they reveal that a solidity ratio of 0.63 is suitable and is recommended for future research.
Numerical Simulation of Heat Transfer in Finned Tube of Heat Recovery Unit Using Fluid-Solid Coupled Method
Authors: Wei Lin , Zhu Guorong , Jin Zhijiang
Published: March 2015

Heat recovery unit (HRU) is a heat exchange device in drying process. In HRU, room air is preheated by waste hot air and then transported to drying oven to remove moisture, which helps to save both energy and time. The main purpose of this paper is to build a heat transfer model of HRU and study its characteristics. A numerical method based on fluid-solid coupling was used to calculate the heat transfer between tube and fluids, and the actual structure was simplified to improve computation efficiency. The results were validated by theoretical calculation and experiments. Effects of Reynolds number (Re) on outlet temperature, Nusselt number, and pressure drop were investigated. It was found that the thermal resistance of shell side is large, by reducing which the total heat transfer coefficient can be improved. The difference between finned tube and smooth tube is in the shell side. Larger Re of shell side leads to good heat transfer performance but also larger pressure drop which increases the flow resistance.
The Effect of Wettability on the Dynamical Behaviors of Single-Walled Carbon Nanotube
Authors: Yan Yan , Li Weizhong , Wang Wenquan
Published: March 2015

The dynamical behaviors of single-walled carbon nanotube (SWCNT) with the internal and external wettability are studied based on a multiple flexible shell model in the paper. The SWCNT-water system comprises five constituent parts, that is, the SWCNT, the absorbed inner and outer layers of water molecules, the water in the center of the SWCNT, and the water surrounding the absorbed outer water layer. Here we consider the absorbed water layers as infinitesimally thin shells, which interact with the nanotube via a continuum Lennard-Jones potential, and the water in the center of the SWCNT and the counterpart surrounding the absorbed outer water layer as the potential flow. It is found that the interactions of SWCNT and the water layer are responsible for an upshift in the frequency of the SWCNT and the total upshift is approximately the sum of the two corresponding upshifts. The vdW interactions also cause the increase of the frequency of internal and external water shells. We hope that the paper can offer a new modeling approach to determine whether carbon nanotubes have adsorbed fluids inside their pores and could be used for detecting changes in their filling state.
A Theoretical Comparative Study on Nanorefrigerant Performance in a Single-Stage Vapor-Compression Refrigeration Cycle
Authors: Aktas Melih , Dalkilic Ahmet Selim , Celen Ali , Cebi Alican , Mahian Omid , Wongwises Somchai
Published: March 2015

The topic of nanofluid heat transfer is certainly of interest to the heat transfer community. Nanorefrigerants are a type of nanofluids that are mixtures of nanoparticles and pure refrigerants. This paper focuses on five different nanorefrigerants with Al2O3 nanoparticles and their pure fluids: R12, R134a, R430a, R436a, and R600a. The coefficient of performance (COP) and compressor work for various evaporation and condensation temperatures are investigated. A method is developed to estimate the performance characteristics of nanorefrigerants in the refrigerant cycles for the nonsuperheating/subcooling case and superheating/subcooling case. The enthalpy of nanorefrigerants is obtained through the density. The validation process of the proposed method was accomplished with the available data in the literature. The results indicate that COP is enhanced by adding nanoparticles to the pure refrigerant and maximum values obtained using the R600a/Al2O3 mixture.
Passing Stages Division of the Pedestrians and Bicycles Conglomeration at Signalized Intersection of Chinese City
Authors: Xu Ting , Liu Jinguang , Dai Shuai
Published: March 2015

This paper mainly studies how to divide the passing stages of the pedestrians and bicycles conglomeration at signalized intersection in Chinese urban area. The conception of pedestrians and bicycles conglomeration is defined after analyzing the two-stage characteristics of pedestrians and bicycles groups. Seven intersections were chosen in Beijing as examples. After video analysis, the real-time displacement and the real-time velocities of seven intersections in one signal cycle are extracted. It is found that the procedure of pedestrians and bicycles passing the intersection can be divided into two stages, which shows distinct characteristics. Video records taken from the observational survey are used to extract the real displacement of pedestrians and bicycles and the passing behaviors images. A new approach is presented to calculate the occupation ratio of the pedestrians and bicycles conglomeration, based on the “suppositional grids” division of the effective crosswalks. Finally, the grey relational analysis is applied to divide the mixed groups’ passing stages based on the occupation ratio of conglomeration. A signalized intersection in Beijing is presented as a case study, and the passing stages are clustered into four stages from initial five stages and the results indicate that the trend of change in different stages is obvious.
Design, Simulation, and Optimization of a Frequency-Tunable Vibration Energy Harvester That Uses a Magnetorheological Elastomer
Authors: Sun Wan , Jung Jeehyun , Wang Xiao Yu , Kim Pilkee , Seok Jongwon , Jang Duk-young
Published: March 2015

This study focuses on the design, simulation, and load power optimization for the development of a novel frequency-tunable electromagnetic vibrational energy harvester. The unique characteristic of a magnetorheological elastomer (MRE) is utilized, that the shear modulus can be varied by changing the strength of an applied magnetic field. The electromagnetic energy harvester is fabricated, the external electric circuit is connected, and the performance is evaluated through a series of experiments. The resonant frequencies and the parasitic damping constant are measured experimentally for different tuning magnet gap distances, which validate the application of the MRE to the development of a frequency-tunable energy harvesting system. The harvested energy of the system is measured by the voltage across the load resistor. The maximum load power is attained by optimizing the external circuit connected to the coil system. The analysis results are presented for harvesting the maximum load power in terms of the coil parameters and external circuit resistance. The optimality of the load resistance is validated by comparing the analytical results with experimental results. The optimal load resistances under various resonance frequencies are also found for the design and composition of the optimal energy harvesting circuit of the energy harvester system.
Design and Analysis of a Thermoelectric Module to Improve the Operational Life
Authors: Bakhtiaryfard Leila , Chen Yeong Shu
Published: March 2015

This work proposes a method for reducing mechanical stresses induced in thermoelectric (TE) structure to increase the operational life of the device. For this purpose, based on preliminary studies of the deformation and stress contours of existing thermoelectric modules, a new circular arrangement for the thermoelements layout is designed. Numerical simulations for various geometries of TE modules have been done to investigate their thermomechanical/structural behavior under the same operating conditions. Simulation results show a significant reduction in the shear stress, the von Mises stress, and the total deflection relative to the existing rectangular layout design. In order to prove our finite element analysis is correct, two experiments have been done: 1) shear testing for stress analysis; 2) shadow moiré technique for deformation analysis. The result obtained from experiments is then compared with the results from their simulated model in ANSYS. There is pretty good agreement between manual calculation, experiments, and simulation results. In addition to all these, theoretical calculations of the stresses result from the bending moment and transverse shear force have been done. It is concluded that the new layout reduced the maximum stresses and the total deflections, which can greatly influence the operation lifetime of the components of the thermoelectric module.
On the Emissivity and Absorptivity of Plastic Shading Nets under Natural Conditions
Authors: Abdel-Ghany Ahmed M. , Al-Helal Ibrahim M. , Shady Mohamed R.
Published: March 2015

It is impossible to directly measure the thermal radiative properties of shading nets because of the net's perforated structure and the difficulty to distinguish the transmitted, reflected, and emitted radiation on the net surface. In addition, Kirchhoff's identity was derived for an object in thermal equilibrium and exchanges only thermal radiation with its surrounding, and the assumption that is valid for an object exchanging solar and thermal radiation and convection with the surrounding is unclear. This study was to (i) develop a theoretical model to predict the absorptivity, α n; transmissivity, τ n; reflectivity, ρ n; and emissivity, ∊ n, of plastic nets and (ii) examine the equality (∊ n = α n) under natural conditions. Nets with different porosities, texture structures, and colors were tacked onto a wooden frame, fixed horizontally over a black substrate. Thermal radiation balance was applied to the net-substrate system. The model input parameters (i.e., the thermal radiation fluxes below and above the net; the net and substrate temperatures) were measured on sunny days. The estimated values of α n and τ n were in the ranges 0.41–0.82 and 0.16–0.55, respectively, whereas ρ n ≤ 0.08 for the nets tested. Under the steady-state natural conditions, ∊ n = α n for a net in thermal equilibrium. However, the solar and thermal radiation absorbed by the net did not equal the emitted radiation.
Determining Commuting Behaviour from Monitoring Technologies
Authors: You Yuting , Wang Wei , Yang Min , Thompson Russell G.
Published: March 2015

The study of commuting behaviour has always been one significant focus of people to reach comprehensive knowledge of transport-related scenarios. Similarly, commuting behaviour, as one of the four major physical activities people engaged in during daily life, gained much attention in aspect of health fields. This paper, with the sample data collected by The Australian Diabetes, Obesity and Lifestyle (AusDiab) study, discusses the process of how to utilize data obtained from GPS and inclinometer device, along with basic information about participants to conduct travel survey, and reconstructing participant's commuting behaviour. In the analyses of the sample, the procedure of datasets integration through DELPHI programming and protocols established to determine corresponding commuting behaviour are discussed. The details of commuting behaviour illustrated in this study included travel mode, travel duration, allocation of trip stages, and corresponding level of physical activities. This paper discusses a promise for applying advanced technologies in travel survey instead of traditional ones in terms of accuracy and reliability; it discusses the feasibility to discover the coherent relationship between health outcome and commuting behaviour from travel-tracking technologies.
The Helical Oscillating Heat Pipe: Flow Pattern Behaviour Study
Authors: Sriudom Y. , Rittidech S. , Chompookham T.
Published: March 2015

This research aims to study the effect of evaporator temperature, pitch distance, and working fluid on the internal flow pattern and the heat transfer characteristics of the helical oscillating heat pipe. A Pyrex tube with an inner diameter of 2.4 mm was used to study the flow pattern in the evaporator section. The pitch distance varied at 1, 1.5, and 2 cm. Water and R-123 were used as working fluid with a filling ratio of 80% by total volume. In the evaporator section, the water temperature varied at 60, 75, and 90°C to supply heat to the heat pipe. In the condenser section, air with a temperature of 25°C was used as heat sink. From the results, it was found that 4 internal flow patterns, bubble flow, slug flow, annular flow, and stratified wavy flow, were observed in the evaporator section for both working fluids. The heat transfer rate decreased when the pitch distance was increased from 1 to 2 cm. The maximum heat flux was 2,132.6 and 1,773.4 W/m2 for the working fluid of R-123 and water, respectively. Both occurred at a pitch distance of 1 cm and an evaporator temperature of 90°C.
Study on the Seepage and Stability of Carbon Dioxide Geological Storage in Scrap Metal Mine: A Finite Difference Analysis
Authors: Li Qingwen , Qiao Lan , Ma Siwei , Dasgupta Gautam , Wang Liping , Li Yuan
Published: March 2015

The carbon dioxide geological storage is one of the most effective ways to slow down the earth's climate warming. The ideal location for storage is in the deep scrap mines. Because of the characteristics of the deep underground condition, the long-term mechanical stability must have close relationship with the geostress fields and permeability, whose development can determine and reflect the mechanical behaviors of carbon dioxide geological storage. The permeability of host rock is affected by existing joints and discontinuity surfaces. Furthermore, as the liquid carbon dioxide is injected into the geological storage, the injection pressure and buoyancy force will change the state of geostress obviously. In this paper, based on mechanical properties of the host rock (granite), coupled brittle shear constitutive model was adopted and the analysis module was implemented in software FLAC3D. Then, with the in situ survey of joints in the host rock and the monitoring of in situ geostress, the permeability characteristics and geostress inverse analysis were input in FLAC3D. At last, fluid-solid coupled model was used to analyze the seepage characteristics of each phase after the injection and long-term storage of liquid carbon dioxide. Therefore, the systematic analysis of the storage stability of carbon dioxide geological could be carried out.
Optimizing the Heat Dissipation of an Electric Vehicle Battery Pack
Authors: Hwang Hsiu-Ying , Chen Yi-Shin , Chen Jia-Shiun
Published: March 2015

Battery packs are critical components to electric vehicles. They are designed to last for the designed life cycles. Temperature affects the performance and life span of batteries. Maintaining stable and evenly distributed temperatures within the operating temperature range among all modules and battery cells is one of key factors to prolong the life of battery packs. This paper studied the effects of the ventilation locations of the inlets and outlets and the gaps among battery cells on the rate of heat dissipation and temperature distribution in the pack. An existing battery pack was used as a baseline design. A computational fluid dynamics model was created to analyze the temperature distribution and air flow conditions. The design intent is to keep the package changes to the minimum but with better cooling efficiency. The results show that the locations and shapes of inlets and outlets have significant impact on the battery heat dissipation. A design is proposed to minimize the temperature variation among all battery cells. The temperature difference between highest and lowest ones for the evaluated event is reduced from 6.04°C to 3.67°C with 39% improvements, and the heat dissipation rate is improved with 3.8%.
Research on Effective Electric-Mechanical Coupling Coefficient of Sandwich Type Piezoelectric Ultrasonic Transducer Using Bending Vibration Mode
Authors: Zhang Qiang , Shi Shengjun , Chen Weishan
Published: March 2015

An analytical model on electromechanical coupling coefficient and the length optimization of a bending piezoelectric ultrasonic transducer are proposed. The piezoelectric transducer consists of 8 PZT elements sandwiched between four thin electrodes, and the PZT elements are clamped by a screwed connection between fore beam and back beam. Firstly, bending vibration model of the piezoelectric transducer is built based on the Timoshenko beam theory. Secondly, the analytical model of effective electromechanical coupling coefficient is built based on the bending vibration model. Energy method and electromechanical equivalent circuit method are involved in the modelling process. To validate the analytical model, sandwich type piezoelectric transducer example in second order bending vibration mode is analysed. Effective electromechanical coupling coefficient of the transducer is optimized with simplex reflection technique, and the optimized ratio of length of the transducers is obtained. Finally, experimental prototypes of the sandwich type piezoelectric transducers are fabricated. Bending vibration mode and impedance of the experimental prototypes are tested, and electromechanical coupling coefficient is obtained according to the testing results. Results show that the analytical model is in good agreement with the experimental model.
Simulator Evaluation of Drivers’ Performance on Rural Highways in relation to Drivers’ Visual Attention Demands
Authors: Qin Yaqin , Xiong Jian , Jiang Yubo , Guo Fengxiang , Wan Huasen , Jiang Lianghua , Jia Xianguang
Published: March 2015

Aim of the study is to investigate, by means of a driving simulator experiment, drivers’ performance in terms of lateral position, speed, deceleration, steering angle, and breaking times on a divided two-lane rural highway in relation to drivers’ visual attention (VD). In the experiment, the virtual scene of twenty different geometric alignment sections without traffic and the VD testing were designed. Twenty-three experienced drivers with the calibration of attention capacity participated in a 30 km drive in an interactive fixed-base simulator. Each participant was required to drive with the controlled speed of 60 km/h along the central lane as repeating random number and was evaluated on VD and driving performances. Three different data analysis techniques were used: (a) statistical tests and hypothesis test of curvature change rate (CCR) of the geometric alignments, visual attention demands, and driving performance data, (b) correlation analysis of VD, CCRs, and driving behaviors, and (c) regression analysis of the VD and CCRs. Results have showed that the driving performance can be effectively influenced by the highway alignment and a prediction model built in this study can evaluate the drivers’ visual attention demands before the highway constructed. The interactions among VD, driving behavior, and CCRs were also found.
Research on Robot Surface Tracking Motion Based on Force Control of Six-Axis Wrist Force Sensor
Authors: Wang Zhijun , Liu Wanyu , Cui Bingyan , He Jing , Li Zhanxian , Zhao Yongsheng
Published: March 2015

In order to reduce the environmental contact force and make the operation task completed successfully, the robot is frequently required with force perception and active compliance control. Based on the six-axis wrist force sensor measuring, a robot model of surface tracking motion is proposed, and its force control algorithm and experiment are studied. The measurement principle of the six-axis wrist force sensor and the inadequacy of the sensor measuring the six-dimensional force online are introduced firstly. The surface tracking motion model and its coordinate system are established. On this basis, the relationship between the pose adjustment of surface tracking motion and the measuring results of the six-axis wrist force sensor is deduced. At last, the experimental study of the surface tracking robot system that applied the force control algorithm is conducted. The experiment shows that the robot can adjust the current position and orientation in real time according to the six-axis wrist force sensor measuring, which demonstrates the feasibility of the surface tracking motion model and the correctness of the force control algorithm.
Preparation and Characterization of Silver Liquid Thin Films for Magnetic Fluid Deformable Mirror
Authors: Zhang Lianchao
Published: March 2015

Silver liquid thin film, formed by silver nanoparticles stacking and spreading on the surface of the liquid, is one of the important parts of magnetic fluid deformable mirror. First, silver nanoparticles were prepared by liquid phase chemical reduction method using sodium citrate as reducing agent and stabilizer and silver nitrate as precursor. Characterization of silver nanoparticles was studied using X-ray diffractometer, UV-vis spectrophotometer, and transmission electron microscope (TEM). The results showed that silver nanoparticles are spherical and have a good monodispersity. Additionally, the effect of the reaction conditions on the particle size of silver is obvious. And then silver liquid thin films were prepared by oil-water two-phase interface technology using as-synthesized silver nanoparticles. Properties of the film were investigated using different technology. The results showed that the film has good reflectivity and the particle size has a great influence on the reflectivity of the films. SEM photos showed that the liquid film is composed of multilayer silver nanoparticles. In addition, stability of the film was studied. The results showed that after being stored for 8 days under natural conditions, the gloss and reflectivity of the film start to decrease.
Study on Driver's Fixation Variation at Entrance and Inside Sections of Tunnel on Highway
Authors: Yan Ying , Yuan Huazhi , Wang Xiaofei , Xu Ting , Liu Haoxue
Published: March 2015

How drivers’ visual characteristics change as they pass tunnels was studied. Firstly, nine drivers’ test data at tunnel entrance and inside sections using eye movement tracking devices were recorded. Then the transfer function of BP artificial neural network was employed to simulate and analyze the variation of the drivers’ eye movement parameters. The relation models between eye movement parameters and the distance of the tunnels were established. In the analysis of the fixation point distributions, the analytic coordinates of fixations in visual field were clustered to obtain different visual area of fixations by utilizing dynamic cluster theory. The results indicated that, at 100 meters before the entrance, the average fixation duration increased, but the fixations number decreased substantially. After 100 meters into the tunnel, the fixation duration started to decrease first and then increased. The variations of drivers’ fixation points demonstrated such a pattern of change as scatter, focus, and scatter again. While driving through the tunnels, drivers presented a long time fixation. Nearly 61.5% subjects’ average fixation duration increased significantly. In the tunnel, these drivers pay attention to seven fixation points areas from the car dashboard area to the road area in front of the car.
A Novel Method for Bending Stiffness Evaluation of Bus Body
Authors: Na Jingxin , Yuan Zheng , Gao Jianfeng
Published: March 2015

Bending stiffness is an important factor to determine the mechanical performance of bus body skeleton. Traditional computational method for bending stiffness is sensitive to local deformation and load applications, which often results in great fluctuation to the computational results. This paper proposes an advanced computational method for bending stiffness based on deformable feature curve of bus body. Firstly, the feature point collection from the deformation of bus body under bending conditions is extracted. Secondly, all the feature points are processed by means of coordinate transformation and then the feature curve of bus body deformation is established via piecewise cubic curve-fitting. Lastly, the expected value of bending stiffness of bus body is obtained through the stiffness samples which are computed according to the feature curve. Furthermore, a FORTRAN program is written to implement the method. Compared with the traditional methods, the validity and stability of this method are verified via several numerical examples. This method is meaningful to the conceptual design of a bus body, as the experimental measures are difficult to be carried out in the early stage.
A Numerical Analysis on Nanofluid Mixed Convection in Triangular Cross-Sectioned Ducts Heated by a Uniform Heat Flux
Authors: Manca Oronzio , Nardini Sergio , Ricci Daniele , Tamburrino Salvatore
Published: March 2015

In this paper, results obtained by the numerical investigation on laminar mixed convection in triangular ducts, filled with nanofluids, are presented in order to evaluate the fluid dynamic and thermal features of the considered geometry by considering Al2O3/water based nanofluids. The system is heated by a constant and uniform heat flux also along the perimeter of the triangular duct section in H2 mode as thermal boundary condition and the single-phase model has been assigned for a Reynolds number value equal to 100. Results are given for different nanoparticle volume concentrations and Richardson number values ranging from 0% to 5% and from 0 to 5, respectively. Results, presented for the fully developed regime flow, show the enhancement of average convective heat transfer coefficients values for increasing values of Richardson number and particle fractions. However, wall shear stress and required pumping power profiles increase as expected. The PEC analysis showed that the use of nanofluids in mixed convection seems slightly convenient. It should be underlined that, at the moment, experimental data are not available to compare the numerical proposed model for mixed convection in horizontal triangular ducts with nanofluids.
Corrected Statistical Energy Analysis Model for Car Interior Noise
Authors: Putra A. , Al Munawir  , Farid W. M.
Published: March 2015

Statistical energy analysis (SEA) is a well-known method to analyze the flow of acoustic and vibration energy in a complex structure. For an acoustic space where significant absorptive materials are present, direct field component from the sound source dominates the total sound field rather than a reverberant field, where the latter becomes the basis in constructing the conventional SEA model. Such environment can be found in a car interior and thus a corrected SEA model is proposed here to counter this situation. The model is developed by eliminating the direct field component from the total sound field and only the power after the first reflection is considered. A test car cabin was divided into two subsystems and by using a loudspeaker as a sound source, the power injection method in SEA was employed to obtain the corrected coupling loss factor and the damping loss factor from the corrected SEA model. These parameters were then used to predict the sound pressure level in the interior cabin using the injected input power from the engine. The results show satisfactory agreement with the directly measured SPL.
A New Sampling Approach for Response Surface Method Based Reliability Analysis and Its Application
Authors: Meng Xin-Jia , Jing Shi-Kai , Zhang Li-Xiang , Liu Ji-Hong , Yang Hai-Cheng
Published: March 2015

A response surface method based on the all sample point interpolation approach (ASPIA) is proposed to improve the efficiency of reliability computation. ASPIA obtains new sample points through linear interpolation. These new sample points are occasionally extremely dense, thus easily generating an ill-conditioned problem for approximation functions. A mobile most probable failure point strategy is used to solve this problem. The advantage of the proposed method is proven by two numerical examples. With the ASPIA, the approximated process can rapidly approach the actual limit equation with accuracy. Additionally, there are no difficulties in applying the proposed ASPIA to the response surface model with or without cross terms. Solution results for the numerical examples indicate that the use of the response surface function with cross terms increases time cost, but result accuracy cannot be improved significantly. Finally, the proposed method is successfully used to analyze the reliability of the hydraulic cylinder of a forging hydraulic press by combining MATLAB and ANSYS software. The engineering example confirms the practicality of this method.