bluuebunny/crossref_metadata_2025 huggingface dataset:
Differences in Neuromuscular Control and Quadriceps Morphology Between Potential Copers and Noncopers Following Anterior Cruciate Ligament Injury
Authors: MacLeod Toran D. , Snyder-Mackler Lynn , Buchanan Thomas S.
Published: November 2013

Study Design

Prospective cross-sectional study.

Objectives

To compare knee muscle morphology and voluntary neuromuscular control in individuals who sustained an anterior cruciate ligament (ACL) injury and were identified as being capable of avoiding surgery (potential copers) and those who were recommended for surgery (noncopers), within 6 months of injury.

Background

Quadriceps atrophy and poor neuromuscular control have been found in noncopers. However, the reasons why some noncopers may be able to avoid surgery remain elusive.

Methods

Twenty participants (10 ACL-deficient noncopers and 10 ACL-deficient potential copers) were included in this study. Axial spin-echo, T1-weighted magnetic resonance imaging data of the lower extremities were captured. The volume and maximum cross-sectional area (CSA) of each muscle of the quadriceps and hamstrings were calculated following digital reconstruction. In addition, voluntary neuromuscular control was evaluated using an established target-matching task that required participants to produce static isometric loads across the knee joint. Electromyography was acquired from 5 muscles as participants performed the target-matching task. Circular statistics were used to calculate a specificity index to describe how well focused each muscle was activated toward its primary direction of muscle action. The ACL-deficient limb was then compared to the uninvolved limb of the noncopers and potential copers.

Results

The vasti (vastus medialis and vastus intermedius) of the involved limb of the noncopers were significantly smaller (P<.031) in comparison to those of their uninvolved limb. The potential copers' vastus lateralis maximum CSA (P = .047), total quadriceps muscle volume (P = .020) and maximum CSA (P = .015), and quadriceps-hamstring ratio volume (P = .021) and maximum CSA (P = .007) demonstrated quadriceps atrophy. However, only the ACL-deficient limb of the older (mean ± SD age, 27.4 ± 11.4 versus 19.9 ± 3.3 years; P = .032) and lower-activity-level (3.3 ± 0.5 versus 3.6 ± 0.5; P = .098) noncoper group demonstrated reduced rectus femoris (P = .057) and lateral hamstring (P = .064) neuromuscular control in comparison to their uninvolved limb.

Conclusion

These findings suggest that quadriceps and hamstring muscle function, rather than muscle size, may be an important factor in the varied response early after ACL injury. J Orthop Sports Phys Ther 2014;44(2):76–84. Epub 21 November 2013. doi:10.2519/jospt.2014.4876
Toward Participatory Communal Citizenship
Authors: Knight Michelle G. , Watson Vaughn W. M.
Published: November 2013

Rendering visible African immigrants’ shared and differing experiences of civic learning and action, the authors present findings from in-depth semi-structured interviews with second- and 1.5-generation African immigrants in New York City. Drawing on an interdisciplinary framework of African immigrant identities constructions and civic engagement, we highlight a multilayered view of civic teaching, learning, and action within and across contexts of families, identities, and schooling in the United States, Africa, and globally. In so doing, the research affirms African immigrant youth’s racial and ethnic identities toward broadened understandings of civic engagement such as participatory communal citizenship. The findings support the need for teacher educator preparation for immigrant youth and curriculum within secondary schools in a diverse U.S. society.
The Direct Arylation of Benzoquinones with Arylboronic Acid Promoted by Iron(II) Oxalate
Authors: Huang Yibo , Guan Dan
Published: November 2013

Arylations of various quinones with several arylboronic acids have been developed. The reactions proceed readily at ambient temperature using iron(II) oxalate as a catalyst and potassium persulfate as a co-oxidant. The mechanism is presumed to proceed through a nucleophilic radical addition to the quinone with in situ reoxidation of the resulting dihydroquinone.
Synthesis, Antimalarial and Antileishmanial Activity of Novel 13-Benzyl-15,16-Bisnorlabdane Derivatives
Authors: Salazar Franklin J. , Quintero Alberto , de Domínguez Neira Gamboa , Concepción Juan L. , Acosta María E. , Tropper Eleonora , Villamizar José E.
Published: November 2013

Twelve 13-benzyl-15,16-bisnorlabdanes in which the C-13 and C-14 substituents are varied have been prepared from the naturally occurring labdane diterpene (+)-manool. These synthesised compounds were evaluated for antimalarial activity, in vitro as hemozoin formation inhibitors and in vivo against Plasmodium berghei. These derivatives were also assayed for antileishmanial activity against Leishmania mexicana.
Indium-Catalysed Multicomponent Reaction of Acetals with Dibenzylamine and Alkynes
Authors: Zhang Xue-Lin , Wu Qin-Pei , Zhang Qing-Shan
Published: November 2013

A reaction of acetals with dibenzylamine and alkynes to form propargylamines has been developed via the activation of both C(sp3)-O and C(sp)-H bonds by InCl3. The iminium ion has been found to be the key intermediate.
Solvent-Free One-Pot Synthesis of 2-Thioxodihydro-1H-Imidazole-4,5-Dione using a Multi-Component Reaction of Oxalyl Chloride
Authors: Hossaini Zinatossadat
Published: November 2013

A series of 2-thioxodihydro-1 H-imidazole-4,5-dione derivatives are synthesised via a one-pot multicomponent reaction of primary amines, aryl isothiocyanates and oxalyl chloride under solvent-free conditions at 70 °C in good yields.
DNA Damage Response in Plants: Conserved and Variable Response Compared to Animals
Authors: Yoshiyama Kaoru , Sakaguchi Kengo , Kimura Seisuke
Published: November 2013

The genome of an organism is under constant attack from endogenous and exogenous DNA damaging factors, such as reactive radicals, radiation, and genotoxins. Therefore, DNA damage response systems to sense DNA damage, arrest cell cycle, repair DNA lesions, and/or induce programmed cell death are crucial for maintenance of genomic integrity and survival of the organism. Genome sequences revealed that, although plants possess many of the DNA damage response factors that are present in the animal systems, they are missing some of the important regulators, such as the p53 tumor suppressor. These observations suggest differences in the DNA damage response mechanisms between plants and animals. In this review the DNA damage responses in plants and animals are compared and contrasted. In addition, the function of SUPPRESSOR OF GAMMA RESPONSE 1 (SOG1), a plant-specific transcription factor that governs the robust response to DNA damage, is discussed.
A Novel Glass Polyalkenoate Cement for Fixation and Stabilisation of the Ribcage, Post Sternotomy Surgery: An ex-Vivo Study
Authors: Alhalawani Adel , Curran Declan , Pingguan-Murphy Belinda , Boyd Daniel , Towler Mark
Published: November 2013

This study investigates the use of gallium (Ga) based glass polyalkenoate cements (GPCs) as a possible alternative adhesive in sternal fixation, post sternotomy surgery. The glass series consists of a Control (CaO–ZnO–SiO2), and LGa-1 and LGa-2 which contain Ga at the expense of zinc (Zn) in 0.08 mol% increments. The additions of Ga resulted in increased working time (75 s to 137 s) and setting time (113 to 254 s). Fourier Transform Infrared (FTIR) analysis indicated that this was a direct result of increased unreacted poly(acrylic acid) (PAA) and the reduction of crosslink formation during cement maturation. LGa samples (0.16 wt % Ga) resulted in an altered ion release profile, particularly for 30 days analysis, with maximum Ca2+, Zn2+, Si4+ and Ga3+ ions released into the distilled water. The additions of Ga resulted in increased roughness and decreased contact angles during cement maturation. The presence of Ga has a positive effect on the compressive strength of the samples with strengths increasing over 10 MPa at 7 days analysis compared to the 1 day results. The additions of Ga had relatively no effect on the flexural strength. Tensile testing of bovine sterna proved that the LGa samples (0.16 wt % Ga) are comparable to the Control samples.
Rapid Microwave Synthesis, Characterization and Reactivity of Lithium Nitride Hydride, Li4NH
Authors: Tapia-Ruiz Nuria , Sorbie Natalie , Vaché Nicolas , Hoang Tuan , Gregory Duncan
Published: November 2013

Lithium nitride hydride, Li4NH, was synthesised from lithium nitride and lithium hydride over minute timescales, using microwave synthesis methods in the solid state for the first time. The structure of the microwave-synthesised powders was confirmed by powder X-ray diffraction [tetragonal space group I41/a; a = 4.8864(1) Å, c = 9.9183(2) Å] and the nitride hydride reacts with moist air under ambient conditions to produce lithium hydroxide and subsequently lithium carbonate. Li4NH undergoes no dehydrogenation or decomposition [under Ar(g)] below 773 K. A tetragonal–cubic phase transition, however, occurs for the compound at ca. 770 K. The new high temperature (HT) phase adopts an anti-fluorite structure (space group Fm 3̅ m; a = 4.9462(3) Å) with N3− and H− ions disordered on the 4a sites. Thermal treatment of Li4NH under nitrogen yields a stoichiometric mixture of lithium nitride and lithium imide (Li3N and Li2NH respectively).
Activation of RhoA,B,C by Yersinia Cytotoxic Necrotizing Factor (CNFy) Induces Apoptosis in LNCaP Prostate Cancer Cells
Authors: Augspach Anke , List Joachim , Wolf Philipp , Bielek Heike , Schwan Carsten , Elsässer-Beile Ursula , Aktories Klaus , Schmidt Gudula
Published: November 2013

Prostate cancer is the most common malignancy, accounting for about 25% of all incident cases among men in industrialized countries. The human androgen-dependent prostate cancer cell line LNCaP, which is derived from a metastatic lesion of human prostatic adenocarcinoma, is frequently used to study prostate cancer associated signaling pathways in vitro. Recently it was described that Rho GTPase activation in these cells leads to apoptotic responses. We used the bacterial toxins CNFy and CNF1, which specifically and directly activate Rho GTPases by deamidation of a single glutamine. We asked whether these Rho activators could induce apoptosis in LNCaP cells. Our results indicate that RhoA activation, induced by CNFy, does lead to intrinsic apoptosis of the cells. Analysis of the underlying signaling pathway reveals that apoptosis induction requires the activity of Rho kinase (ROCK) and myosin activation, an apoptotic pathway previously identified in cancer stem cells.
Epithelial-to-Mesenchymal Transition Enhances the Cardioprotective Capacity of Human Amniotic Epithelial Cells
Authors: Roy Rajika , Kukucka Marian , Messroghli Daniel , Kunkel Désirée , Brodarac Andreja , Klose Kristin , Geißler Sven , Becher Peter Moritz , Kang Sung Keun , Choi Yeong-Hoon , Stamm Christof
Published: November 2013

The amniotic epithelium consists of cells exhibiting mature epitelial cell characteristics, but also varying degrees of stemness. We tested the hypothesis that induction of epithelial-to-mesenchymal transition (EMT) in amniotic epitelial cells (AECs) derived from human placenta enhances their capacity to support the ischemic myocardium. In response to incubation with transforming growth factor-β1 (TGF-β1) protein, AECs lost their cobblestone morphology and acquired a fibroblastoid shape, associated with downregulation of E-cadherin, upregulation of N-cadherin, Akt phosphorylation, and intracellular periostin translocation. EMT—AECs displayed greatly enhanced mobility and secreted gelatinase activity compared with naive AECs. The surface presentation of CD105 and CD73 decreased, and RNA microarray analysis mirrored the loss of epithelial characteristics and transcriptional profile. Unmodified AECs and EMT—AECs were then injected intramyocardially in fully immunocompetent mice after permanent LAD ligation, and heart function was followed by MRI as well as 2D speckle tracking echocardiography after 4 weeks. EMT—AEC-treated infarct hearts displayed better global systolic function and improved longitudinal strain rate in the area of interest. Although no signals of human cells were detectable by histology, infarct size was smaller in EMT—AEC-treated hearts, associated with fewer TUNEL-positive cells and upregulation of periostin, while blood vessel density was increased in both ACE- and EMT—AEC-treated hearts. We conclude that EMT enhances the cardioprotective effects of human AECs.
Evolution of leaf anatomy and photosynthetic pathways in Portulacaceae
Authors: Ocampo Gilberto , Koteyeva Nuria K. , Voznesenskaya Elena V. , Edwards Gerald E. , Sage Tammy L. , Sage Rowan F. , Columbus J. Travis
Published: November 2013

• Premise of the study: Portulacaceae is a family with a remarkable diversity in photosynthetic pathways. This lineage not only has species with different C4 biochemistry (NADP‐ME and NAD‐ME types) and C3‐C4 intermediacy, but also displays different leaf anatomical configurations. Here we addressed the evolutionary history of leaf anatomy and photosynthetic pathways in Portulacaceae.

• Methods: Photosynthetic pathways were assessed based on leaf anatomy and carbon isotope ratios. Information on the NADP‐ME and NAD‐ME C4 variants was obtained from the literature. The evolutionary relationships and trait evolution were estimated under a Bayesian framework, and divergence times were calibrated using the ages obtained in a previous study.

• Key results: C4 photosynthesis is the main pathway in Portulacaceae. One clade (Cryptopetala), however, includes species that have non‐Kranz anatomy and C3 type isotope values, two of which are C3‐C4 intermediates. The ancestral leaf anatomy for the family is uncertain. The analysis showed one origin of the C4 pathway, which was lost in the Cryptopetala clade. Nevertheless, when a second analysis was performed taking into account the limited number of species with NAD‐ME and NADP‐ME data, a secondary gain of the C4 pathway from a C3‐C4 intermediate was inferred.

• Conclusions: The C4 pathway evolved ca. 23 Myr in the Portulacaceae. The number of times that the pathway evolved in the family is uncertain. The diversity of leaf anatomical types and C4 biochemical variants suggest multiple independent origins of C4 photosynthesis. Evidence for a switch from C4 to C3‐C4 intermediacy supports the hypothesis that intermediates represent a distinct successful strategy.
Les établissements scolaires face aux dispositifs d'éducation artistique et culturelle
Authors: Montoya Nathalie
Published: November 2013

À partir de la ré-exploitation de deux ensembles d’enquêtes réalisées en Seine-Saint-Denis et en Rhône-Alpes, cet article revient sur le développement des dispositifs liés à l’éducation artistique et culturelle dans les établissements scolaires du second degré. Parallèlement à l’État et aux initiatives prises par les acteurs culturels, les collectivités territoriales ont développé une offre complexe de dispositifs qui finit par composer un ensemble pluriel et disparate selon les territoires. Cette inégalité est accentuée ou compensée par la diversité des ressources disponibles au sein des établissements scolaires pour s’emparer de cette offre. Ces enquêtes nous permettent de conclure à l’efficacité propre des dispositifs qui président à l’institutionnalisation paradoxale d’un nouveau champ de l’action publique, traversé par des tensions sans cesse réactivées, au croisement des politiques éducatives et de l’action culturelle.
Créativité-habitude : le divorce improbable du travail enseignant. Le cas de l'éducation physique et sportive.
Authors: Jelen Nathalie , Necker Sophie
Published: November 2013

À partir de l’analyse de matériaux issus d’une enquête qualitative auprès d’enseignants du secondaire, combinant entretiens et observations in situ , cet article vise à examiner l’interaction entre deux phases de l’activité du travail : la créativité et l’habitude. Comment, dans les pratiques enseignantes, se déclinent, se distinguent et interagissent créativité et habitude ? Quels sont les facteurs qui les induisent ? Comment et sous quelles conditions la création devient-elle routine et la routine source de création ? Nous discuterons de leur complémentarité en étudiant l’activité de l’enseignant, sa recherche d’une relative stabilité dans les interactions sociales visant à favoriser l’apprentissage des élèves en EPS. Ainsi, l’analyse du travail « en train de se faire » met en évidence différents facteurs agissant sur l’articulation créativité/habitude. Les processus et procédés distinctifs identifiés renvoient aux caractéristiques des acteurs, aux diverses interactions sociales hors et dans la classe (face aux élèves, avec les collègues) ainsi qu’au poids des attendus sociaux et de l’évaluation subjective des effets de l’expérimentation.
Using Emotion Map System to Implement the Generative Chinese Style Music with Wu Xing Theory
Authors: Huang Chih-Fang , Lin En-Ju
Published: November 2013

Wu Xing is an ancient mysterious Chinese philosophy applied to many fields. The Music Emotion Classification (MEC) refers to the music cognition of mind with the categorized emotion result mapping to music parameters. Many researchers focused the topic on the MEC with theory and experiment development in the past decades. This chapter mainly discusses the possibility to synthesize the meta-level algorithmic music based on the analysis result from the previous research, with the proposed Emotion Map System (EMS) mapped into the innovated Wu Xing Emotion Map System (WXEMS), which indicates the emotion situation based on the X-Y coordinate movement in the WXEMS plane. The MEC result shown in the EMS/WXEMS trajectory controls the algorithmic music variation with the proposed mapping rules. In addition, the generative music varies smoothly according to the correspondent WXEMS data changed with any emotion transition, which can apply the technology into the generative background music in Chinese style using the proposed Wu Xing Automated Music System (WXAMS).
The Promotion of European Tourism in the Emerging Countries
Authors: Cipolla-Ficarra Francisco V. , Quiroga Alejandra , Ficarra Valeria M.
Published: November 2013

The authors present the different communication strategies used for the promotion of European tourism in the emerging countries, through Power Point and pyramidal marketing. They also research the veracity and the persuasion strategies used in textual, visual, and hearing information, which go with the images in the interactive presentations. Finally, an analysis technique is presented to detect the possible potential tourists divided in relation to age, education, and knowledge of the use of computers or other interactive systems of mobile multimedia.
Generic Textile Structure Editor
Authors: Győry Georges
Published: November 2013

Non-rectilinear structures dominate traditional Andean weaving patterns. A systematic description is essential for enabling weavers to document and secure intellectual property rights and for preserving their rich cultural heritage. The author presents a system for modelling non-rectilinear as well as rectilinear weaving patterns; it is the first of its kind. The authors have implemented an editor demonstrating the capabilities of the approach and show its application.
Communication Technologies for Older Adults in Retirement Communities
Authors: Bowers Lauren , Rebola Claudia B. , Vela Patricio
Published: November 2013

This chapter presents the research, development, and findings of a communication technology developed to enable older adults living in retirement communities to share public events. The project draws reference from the fields of industrial design, universal design, and computer science to design a technology for residents at a retirement community. Residents were included in the design process by evaluating designed technologies. This study demonstrates the relevance of designing simple yet innovative technologies that meet the needs of older adults.
MLW and Bilingualism
Authors: De Luise Daniela López , Hisgen Débora
Published: November 2013

The language acquisition and generation process is complex and non-linear. The child goes through a series of progressive stages with distinct characteristics. The statistic study of production by age or linguistic groups can be complemented with linguistic models based on morphosyntactic wavelet technology to improve the understanding of concurrent phenomena, which underlie linguistic reasoning.
Fostering Early Literacy Skills with Technology
Authors: Sullivan Pamela M. , Baker Marianne
Published: November 2013

In this chapter, the authors provide an overview of research literature for technology use with emergent-stage literacy learners. They review the overall research on technology for young children, then look at literacy and the role of technology in the classroom. The authors outline the development of literacy skills in the emergent stage (commonly defined as birth to age five). Finally, they use the framework established by the previous studies and the developmental sequence of the emergent stage to critically evaluate several literacy apps and e-books aimed at these learners. The authors finish with a selection of resources for selecting and using technology to foster these early literacy skills.
Framing Complexity
Authors: Loveless Douglas J. , Bodle Aaron
Published: November 2013

This chapter introduces digital animation as an arts-based research medium by laying a theoretical foundation for its use and describing how it can become a participatory methodology. The authors link research through digital animation to performance, ethnodrama, film, photography, and visual arts traditions leading to a rationale for using animation as a qualitative research tool. A vignette of an ongoing ethnography contextualizes animation as a process and as a product. In this chapter, the authors argue that digital animation (1) facilitates the use of metaphorical imagery to vividly and emotively capture lived experiences and (2) invites a unique audience into the research discourse.
Bionic Flexible Wings Design of the Flapper
Authors: Dong Ben Zheng , Li Chang Long , Ji Ai Hong
Published: November 2013

The fixed-wing aircrafts rely mainly on thrust generated by engine and lift produced by wings to keep flying, so there are strict requirements on their speeds and attack angles. The flappers can hover freely in the air like insects because they have different flight principles and forms compared with fixed-wing aircrafts. The flapper is consisted of the flapping-wing, the flapping-wing mechanism and the drive. The flapping-wing is used to generate lifts and thrusts while the wing mechanism and the drive provide main power to the flapping wing. Traditionally, flapper uses rigid wing to provide lift and thrust force. The researches of the insect flapping wing process indicate insect wings would produce certain flexibility and umbrella effect in this process. Based on the above research, the compression molding is employed to manufacture the bionic flexible wing in this article. Whats more, in order to imitate the umbrella deformations at the wing tips, IPMC (Ionic Polymer Metal-Composites) are fixed on the flexible wings to achieve umbrella deformations.
Drag Reduction Study about Bird Feather Herringbone Riblets
Authors: Chen Hua Wei , Rao Fu Gang , Zhang De Yuan , Shang Xiao Peng
Published: November 2013

Flying bird has gradually formed airworthy structures e.g. streamlined shape and hollow shaft of feather to improve flying performance by millions of years natural selection. As typical property of flight feather, herringbone-type riblets can be observed along the shaft of each feather, which caused by perfect alignment of barbs. Why bird feather have such herringbone-type riblets has not been extensively discussed until now. In this paper, microstructures of secondary feathers are investigated through SEM photo of various birds involving adult pigeons, wild goose and magpie. Their structural parameters of herringbone riblets of secondary flight feather are statistically obtained. Based on quantitative analysis of feathers structure, one novel biomimetic herringbone riblets with narrow smooth edge are proposed to reduce surface drag. In comparison with traditional microgroove riblets and other drag reduction structures, the drag reduction rate of the proposed biomimetic herringbone riblets is experimentally clarified up to 15%, much higher than others. Moreover, the drag reduction mechanism of herringbone riblets are also confirmed and exploited by CFD.
Propulsive Performance of Flexible Fin with Fluid-Structure Interaction Study
Authors: Liu Bo , Xu Min , Wang Lei , Yang Jie , Zhang Shi Wu
Published: November 2013

Fluid-structure interaction (FSI), which solves the coupling between solid and fluid, has more and more been adopted by researchers to better study interaction between the hydrodynamic and structural flexibility. In this paper we adopt FSI and study a model simplified from the pectoral fin of Koi Carp. Flexibility is a comprehensive assessment of soft structures, it not only relates to the material constitutive parameter, but also relates to the apparent morphology parameter. The Young’s modulus and moment of inertia are two typical parameters. In this paper we first investigate the Young’s modulus’ effect on the propulsive performance, the fluid structures are analyzed and the motions are presented, then we discuss the moment of inertia, their thrust forces are compared. Results show that proper flexibility can greatly increase the thrust forces while too flexible fin’s behavior is worse. Moreover, the bending stiffness, a uniform parameter combines the material property and morphology parameter, is explored. It is found out that even for the same bending stiffness, different couples of Young’s modulus and moment of inertia will lead to different propulsive performance. These findings will provide a useful guidance for the design and manufacture of novel flexible underwater bio-mimetic vehicles.
Analysis of Characteristics and Applications of IPMC Material Using Nafion Membrane
Authors: Xu Yan , Zhao Gang , Zhu Yu Min , Yang Li Ming , Ma Chang Shun , Sun Zhuang Zhi , Sui Zhi Yang
Published: November 2013

In order to improve the IPMC artificial muscle output force, research the forming process of the Nafion membrane, prepare the different thickness of the Nafion membrane, select the Nafion membrane of 1 mm and 2 mm for preparation IPMC, test the output force of IPMC samples end. The results show that, with the thickness of base film increasing, IPMC tip output force increases. Based on the characteristics of low drive voltage of IPMC material and high response deformation, design a kind of imitation raie propulsion system. The power supply voltage of the device is 1 ~ 3 v, through controlling the change of driving voltage amplitude which load on the IPMC material and the change of frequency to control the speed of imitation raie propulsion system. From the underwater actual testing, the highest travelling speed is 1 cm/s. Through the experiment effectively proves the feasibility of IPMC material as an actuator.
Research on the Performance Influence of Second Adhesive to Friction Materials
Authors: Peng Jie , Liu Yu Cheng , Yan Zhi Feng , Wang Bao Gang , Lin Fu Dong , Zhuang Jian , Ma Yun Hai
Published: November 2013

The friction materials have many species and they are being used widely, but people have higher requests to friction materials along with the development of technology. the friction material of this expermental optimization formula have the advantages of suitable and stable friction coefficient under high temperature, low wear rate, good restoration characteristics and so on. It can effcetively reduce heat fade of friction and wear under high temperature barking. fricton and wear performance of friction material with second adhesive is better than common preparation friction material , it has higher friction coefficient and lower wear rate, It was determined by physical chemical properities of tin and sulfer. while heating or wearing, the temperature of friction material reach melting temperature of tin, it will become molten state, and sulfer has strong oxidation, on the one hand, tin and sulfer occurred chemical reaction, generating sulfide, stannous (one sulfide tin),on the other hand, while the sulfer is being molten state, it will absorb some abrasive dust, at the same time of generating sulfide, abrasive dust will be adsorb and solidify to pits of friction surface, forming abrasive dust membrane, let the friction coefficient of sample become stable rapidly, reducing the wear rate of friction material.
Power Supply Design of Magnetic Resonance Sounding Equipment for Detecting Mine Groundwater
Authors: Sun Chen , Lin Jun
Published: November 2013

On the basis of the principles and characteristics of the various switching power supply, we have designed a high-power supply which can be used for the magnetic resonance sounding equipment for detecting mine ground water. The characteristics of the switching power supply are the full-bridge converter as the main power topology and the SG3525 chip as the core of the control. The high frequency PWM signal generated by the SG3525 can drive the four power switch tubes of the full-bridge circuit to conduct alternately thought the IR2110, so we can get continuous and stable DC output voltage. The design of the switching power supply has a lot of advantages, such as high efficiency, low noise, high stability, and small volume weight.
Design and Simulation of a PAM Based Bionic Elbow Joint
Authors: Hao Li Na , Xiang Chao Qun , Peng Yuan , Xu Xiao Yu , Wang Qi Long
Published: November 2013

A bionic elbow joint driven by motor is lack of flexibility. So a good option is to improve the flexible and power density ratio. This paper has designed a 3-DOF bionic elbow joint based on pneumatic artificial muscle, and the simulation and forward kinematics analysis have been done. The simulation results show that the structure scheme is feasible, and the movement is smooth. This structure can improve the generalization of the bionic joint and then lay a foundation in the serialization and standardization of the transmission part.
Dynamic Electromyographic Models to Assess Elbow Joint Torque
Authors: Chen Wan Zhong , Fan Yue Yu , Lei Jun , Sun Bao Feng
Published: November 2013

Many studies have investigated the relationship between surface EMG and joint torque. Most studies have used EMG amplitude to assess elbow joint torque with dynamic models. In this paper, we used signal length and normalized zero crossing rates together with EMG amplitude to assess elbow joint torque with EMG-to-Torque models. We compared the performance of single feature EMG-to-Torque models and multi-feature EMG-to-Torque models by calculating the RMS error between estimated torque and true torque. The results show that multi-channel and multiple feature combination is superior to that of the single feature only. In this study, surface EMG signals were recorded from biceps and triceps muscles of 15 subjects. Single-channel and single feature linear model, multi-channel and single-feature model, multi-channel and single-feature model, multi-channel and multi-feature linear model were all used to assess elbow joint torque. The lowest RMS error is 7.6% achieved by four-channel multi-feature 18-order linear model.
Tracking Time Variant Neuron Tuning Properties of Brain Machine Interfaces
Authors: Liao Yu Xi , Li Hong Bao , Chen Xi , Zhang Qiao Sheng , Wang Yi Wen , Zheng Xiao Xiang
Published: November 2013

Tuning properties of neurons, which represent how information is encoded in neural firing, are well accepted as time variant. For a steady-performed brain machine interface (BMI), the decoding algorithm should be able to catch this change in time. Unfortunately, an assumption-less tuning property is too complicate to trace. Simplifying the tuning curve to linear or exponential one may lose important information. We propose to approximate the tuning curve with multiple Gaussian functions, and modeled the non-stationary tuning curves by the changes on the Gaussian parameters. Applied on in vivo neural data when the monkey is performing a 2-dimension tracking task, we found the non-stationary tuning properties can be tracked by the changes on parameters of Gaussian components, which greatly decreases the number of parameters need to be observed. Following this idea, we can design an adaptive method by updating parameters of tuning model.
Design and Realization of a Wearable Hip-Airbag System for Fall Protection
Authors: Zhang Qi , Li Hui Qi , Ning Yun Kun , Liang Ding , Zhao Guo Ru
Published: November 2013

Nowadays falls are a serious problem for elderly people with the coming of aged society in the world. According to statistics,hip fracture accounts for the most of the deaths and costs of all the fall-induced injury. This paper presented an airbag system of hip protection, which included air source, sensors, microcontroller, gas circuit and airbags. A six-axial inertial sensor module that integrated an embedded three-axis MEMS accelerometer and three-axis MEMS gyroscope was used to collect human motion data, and a one-axis obliquity sensor was used to collect human angle data. The microcontroller was employed to recognize the activities of daily living (ADL) and falls based on fall detection algorithm and the collected data from sensors. The gas circuit was triggered once the event that the fall would be inevitable was confirmed by the microcontroller, then the compressed gas would fill into airbags through the gas circuit rapidly. Therefore, a buffer would appear between the human body and the ground before the body impacting the ground, which would reduce the impact of the human body. Compressed CO2 was selected as the air source after we tested several kinds of gas. A 16g CO2 pressurized cylinder could provide enough pressure and volume to inflate quickly the airbags. In order to improve the reliability of the gas circuit, a needle valve was optimized from the several designed structures by the experimental optimization methods. Finally, the airbag system was tested in various designed trials. The results indicated that the system gained the satisfaction for the design requirements and would be potential to apply to the protection of hip joint in the fall high-risk people in the future.
Coupling Function and Mechanism of the Bionic Coupling Functional Surface (BCFS) Caused by the Dual Factors of Form and Flexible Material
Authors: Tian Li Mei , Wang Yin Ci , Gao Zhi Hua , Bu Zhao Guo , Ren Lu Quan , Gao Jiu Hao
Published: November 2013

Some living creatures have special structures on their body surfaces, such as smooth and elastic epidermis with subcutaneous tissue having non-smooth structures under certain conditions. The elastic epidermis coupled with non-smooth structures has a special function called bio-coupling functional surface. Imitating this functional surface and applying it in engineering has a potential to solve some engineering problems. Based on the simulation method of fluid-structure interaction (FSI), simulation calculation of the bionic functional surface coupled by the two factors, form and flexible materials was conduct using ADINA software. A viscous and weakly compressible transient flow was selected as a working medium, a discrete solver was selected in numerical calculation and the basic model was chosen as a turbulence model. It is assumed that the coupling surface of the form/flexible materials results is large deformation and large strain. The boundary condition of fluid-structure interaction was set as the calculation surface. The simulation results showed that this coupling is a dynamic process, in which the two factors (form and flexible materials) are influenced by the flow field. As the pressure and velocity of the flow field increase, the coupling process changes from partial coupling to complete coupling, the pressure drag decreased due to the maximum effective stress of bionic coupling surface is very small and the smooth and flexible materials can redistribute pressure by absorbing and releasing energy, the pressure drag thus formed is decreased. Moreover, non-smooth structures (form factor) coupled with flexible materials reduced velocity of working face and minimise energy losses effectively, enabling the bionic coupling surface to reduce drag.
Influence of Jet Hole Configuration on Drag Reduction of Bionic Jet Surface
Authors: Gu Yun Qing , Ru Jing , Gang Zhao , Li Zhao Yuan , Liu Wen Bo , Farid Khattak Muhammad
Published: November 2013

According to the jet hole configuration mode of bionic jet surface and its influence on the drag reduction, as the basic form of jet hole configuration is the isosceles triangle elements, so this was used to establish the computational model of jet hole configuration. In this case, the height and base of the triangles were considered as variable. The SST k-ω turbulence model was used to simulate and research the drag reduction characteristics of bionic jet surface in different configuration modes of jet holes at the main flow field velocity value of 20m/s and the jet velocity value of 0.4~2.0m/s. Also the influence of different configurations of height and base on drag reduction characteristics of bionic jet surface was studied, which got the optimum size of jet hole configuration. Results show that in triangle configuration elements, the drag reduction characteristics of bionic jet surface can be influenced by the jet hole of different configurations of height and base; the drag reduction of bionic jet surface reaches the peak of 32.74% at 8mm height, 11mm base, and the jet velocity value of 2.0m/s. At the same flow field velocity, the drag reduction rate results achieved by experimental tests and by numerical simulation were changing consistently and were found same, which verifies correctness of numerical simulation results.
Wind Tunnel Test for Drag Reduction of Airfoil Bionic Soft Surface
Authors: Zhang Xue Peng , Wang Yong Hua , Ren Lu Quan
Published: November 2013

The soft surface of birds and aquatic organisms in the nature can effectively reduce the drag. Inspired by the fact,in this paper, an attempt is made to stick silicone rubber soft surface on the surfaces of NACA 4412 and NACA 6409 airfoils. The drags, lifts and lift-drag ratios of airfoils with soft and rigid surfaces in 5 different thickness were compared through wind tunnel test under the condition of α = 0 °. The results show that most of the bionic soft surfaces play the role of reducing the aerodynamic drag, and also increasing the lift at the same time, in which the soft surface of 0.6mm had the most significant effect of drag reduction and lift increasing.
Insect Olfactory Receptors as Essential Detectors for Volatile Chemicals in Biomimetic Odorant Sensors
Authors: Liu Yan , Chen Qian , Man Ya Hui , Wu Wen Jian
Published: November 2013

Insect has a highly sensitive and accurate discrimination capacity for sensing odorants in the environment, though its olfactory system is much simpler than mammalians. Insect olfactory receptor (OR) proteins play key roles in odor detection and discrimination. Unlike the complex olfactory signaling in mammalian, the insect ORs can be directly gated by odorants, and can function without the co-expression of downstream signaling molecules. Therefore, insect ORs hold great promise as detectors in a biosensor for detection of volatile chemicals. Several important OR genes in Drosophila, which respond to explosive vapor or related precursors such as PTEN and 2-ehtyl-hexanol, have been reported. The present work screened and selected OR genes which are sensitive to explosive vapor and related precursors by calcium imaging and electrophysiological techniques. Furthermore, a biomimetic odorant sensor which co-expresses these OR genes and a companion receptor Or83b in living cells is being constructed, in order to classify unknown volatile chemicals and detect specific types of illicit substances. This study provides an alternative way for the construction of odorant sensors, comparing to the traditional electronic noses which are not as sensitive and accurate as natural noses, and would promote the development and application of biomimetic odorant sensors in a range of applications such as security and environmental monitoring.
The Research on Noise Reduction Device Based on Micropore Structure of Honeycomb
Authors: Yao Yong Ming , Liu Shun An , Shang Tao , Lu Yao , Yang Lu Hong , Zhou Xu Hui
Published: November 2013

Cavitation noise is the major source of noise in fluid power transmission system. Noise value is the most important index to measure the quality of equipments. So reducing noise is the primary goal. Honeycomb called a natural miracle has unique structure and good acoustic performance. A kind of noise reduction device was presented in this paper based on micropore structure of honeycomb and micro-perforated panel theory. The design idea and design scheme of the device had been discussed. Then simulation of the device had been done in order to optimize the design ,the number and position of cavitation had been assured and the open porosity was selected as a judgment index. The results of simulation indicated the device added to fluid system could reduce cavitation noise effectively. The device was made and added to the water circuits in experiment field. Eliminating interference of environmental noise,the noise of water circuits system used the device was decreased by 3dB or so compared with system without the device.
Optimal Distribution Strategy for Vehicle Active Yaw Moment Using Bio-Inspired Computing
Authors: Zhao Jian , Luo Jia Qing , Wu Jian , Deng Wei Wen , Zhu Bing
Published: November 2013

This article aims to propose an optimized active yaw moment distribution strategy to improve vehicle safety and stability effectively. A controller based on a 2 DOF vehicle model and a PID controller is designed for the target active yaw moment, which is further allocated into longitudinal tire forces optimally by a particle swarm optimization (PSO) algorithm. The optimal distribution strategy is analyzed using Carsim and Matlab/Simulink co-simulation. The results show that the vehicle handling and stability are improved effectively through the lower workload of the actuators by the proposed control strategy.
Second-Order Statistics-Based Multi-Parameter Estimation of Near-Field Acoustic Sources
Authors: Li Xin Bo , Liu Nan Nan , Jiang Nan , Long Xiao Bo , Jiao Xiao Yang
Published: November 2013

In this paper, a new approach based on the second-order statistics (SOS) and acoustic vector sensor (AVS) array is proposed, for localization estimation of near-field acoustic narrowband sources. Firstly, we choose the centrosymmetric uniform linear-array as the AVS arrangement, and the array is consistent with the coordinate axis direction of the acoustic vector-sensor. This estimation method makes good use of the acquisition information from the AVS, such as one-dimensional sound pressure and three-dimensional particle velocity, and has shown preferable performance for the parameter estimation of direction-of-arrival (DOA) and range of target acoustic sources in the near field. The estimation algorithm expands the near-ﬁeld array manifold of one single acoustic vector sensor to the acoustic vector-sensor’s uniform linear-array, and the near-ﬁeld acoustic vector sensor linear array output model is deduced. The autocorrelation and cross-correlation function of the velocity field and the pressure field are used to construct the rotational invariance frame, which helps to extract the expected information. Consequently, the closed-form solutions of the incident source’s DOA and range are derived explicitly through the parameter pairing operation. The proposed method reduces the computational burden and has good spatial recognition ability and high resolution in the case of limited array elements. It also has better engineering application prospect. Eventually, the performance of the method is verified by Monte Carlo simulation experiments.
Aeroelastic Tailoring of Oscillating Supersonic Wing with External Stores
Authors: Abdullah Nur Azam , Sulaeman Erwin
Published: November 2013

This paper presents aeroelastic tailoring optimization of a swept back supersonic wing with external stores using composite structure material for the wing skin. The analysis has been conducted to calculate the flutter speeds at several altitudes ranging from a negative altitude of-7,943 ft until 30000 ft. MSC Nastran software is used to determine the flutter speed. The objective is to get the lowest possible wing weight by varying the wing skin composite fly angle and thickness as the optimization variables and by considering flutter speed as the optimization constraint. The constraint is imposed such that the flutter speed should be similar or higher than flutter speed of a previously investigated supersonic wing having similar planform but using aluminum as wing skin. The use of composite suggested that each composite layer thickness and fiber angle can be manipulated to achieve the target. The present results indicate that the weight of the composite wing skin can be reduced by 70 % compared to the aluminum wing skin while retaining similar or better flutter speed boundary envelope.
Optical Characterization of Chrysotile for the Real Time Detection
Authors: Ahn Ho Sang , Song Seung Yeon , Ahn Jae Hwan , Jang Dae Gyu , Joo Jin Chul
Published: November 2013

We measured chrominance of chrysotile powder using a colorimeter and a luminance meter under different light sources with seven color filters to test feasibility for the real time asbestos detector development. Chrysotile powder was prepared by heating asbestos fabric at 150 °C for 1hr and hydrochloric acid treatment was followed to remove other elements. Refractive index liquid was used as a color changing analyte to observe the change in chrominance of chrysotile. From the measurements, it revealed that a colorimeter was more suitable for the chrysotile detection by the maximum change in chrominance, especially in the short wave length range of blue regions. A luminance meter was not able to separate the difference in chrominance depending on different color and light sources regardless dyeing. It might be due to that reflected light from chrysotile particle was relatively weaker than that from illuminated area. It is our suggestion that the real time monitoring of asbestos in indoor air can be possible using a color sensor, specified to the unique wavelength of dyed chrysotile based on our chrominance data.
The Model of the Pearl River Water Pollution Based on Reaction Diffusion Equation
Authors: Huang Guan Jia , Fang Shao Mei , Xian Jian , Jiang Jie Mei
Published: November 2013

In this paper, we study the Pearl River cadmium spill. Based on the reaction diffusion equations, we can monitor the concentration of pollutants any time. We find that in 20 kilometers distance from pollution sources, the concentration of cadmium is high. At last, we improve the model.
Hyperbranched Polysiloxane Functionalized Graphene Oxide via Polyhydrosilylation
Authors: Zhang Meng Meng , Yan Hong Xia , Gong Chao , Feng Yi Chen
Published: November 2013

A novel method to functionalize graphene oxide (GO) by hyperbranched polysiloxane via polyhydrosilylation is reported, taking advantage of hyperbranched polysiloxane that possesses good properties such as low viscosity, good rheology, good solubility and high reactivity. The changes in GO surface morphology, chemistry and physical conditions at different stages are characterized by Fourier-transform infrared spectra (FT-IR), X-ray photoelectron spectroscopy (XPS) and Transmission electron microscopy (TEM). XPS analysis shows that the oxygen content of GO is 29.90% and the silicon content of hyperbranched polysiloxane grafted graphene oxide (HBPGO) is 18.66%. The results indicate that hyperbranched polysiloxane is successfully grafted onto the surface of GO and this novel nanostructure may have potential applications in composites.