Search results for: safety mechanisms
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1327

Search results for: safety mechanisms

817 Manufacturing Process of S-Glass Fiber Reinforced PEKK Prepregs

Authors: Nassier A. Nassir, Robert Birch, Zhongwei Guan

Abstract:

The aim of this study is to investigate the fundamental science/technology related to novel S-glass fiber reinforced polyether- ketone-ketone (GF/PEKK) composites and to gain insight into bonding strength and failure mechanisms. Different manufacturing techniques to make this high-temperature pre-impregnated composite (prepreg) were conducted i.e. mechanical deposition, electrostatic powder deposition, and dry powder prepregging techniques. Generally, the results of this investigation showed that it was difficult to control the distribution of the resin powder evenly on the both sides of the fibers within a specific percentage. Most successful approach was by using a dry powder prepregging where the fibers were coated evenly with an adhesive that served as a temporary binder to hold the resin powder in place onto the glass fiber fabric.

Keywords: Dry powder technique, PEKK, S-glass, thermoplastic prepreg.

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816 Multi-Functional Insect Cuticles: Informative Designs for Man-Made Surfaces

Authors: Hsuan-Ming S Hu, Jolanta A Watson, Bronwen W Cribb, Gregory S Watson

Abstract:

Biomimicry has many potential benefits as many technologies found in nature are superior to their man-made counterparts. As technological device components approach the micro and nanoscale, surface properties such as surface adhesion and friction may need to be taken into account. Lowering surface adhesion by manipulating chemistry alone might no longer be sufficient for such components and thus physical manipulation may be required. Adhesion reduction is only one of the many surface functions displayed by micro/nano-structured cuticles of insects. Here, we present a mini review of our understanding of insect cuticle structures and the relationship between the structure dimensions and the corresponding functional mechanisms. It may be possible to introduce additional properties to material surfaces (indeed multi-functional properties) based on the design of natural surfaces.

Keywords: Biomimicry, micro/nanostructures, self-cleaning surfaces, superhydrophobicity

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815 Two Points Crossover Genetic Algorithm for Loop Layout Design Problem

Authors: Xu LiYun, Briand Florent, Fan GuoLiang

Abstract:

The loop-layout design problem (LLDP) aims at optimizing the sequence of positioning of the machines around the cyclic production line. Traffic congestion is the usual criteria to minimize in this type of problem, i.e. the number of additional cycles spent by each part in the network until the completion of its required routing sequence of machines. This paper aims at applying several improvements mechanisms such as a positioned-based crossover operator for the Genetic Algorithm (GA) called a Two Points Crossover (TPC) and an offspring selection process. The performance of the improved GA is measured using well-known examples from literature and compared to other evolutionary algorithms. Good results show that GA can still be competitive for this type of problem against more recent evolutionary algorithms.

Keywords: Crossover, genetic algorithm, layout design problem, loop-layout, manufacturing optimization.

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814 A Theoretical Framework on Using Social Stories with the Creative Arts for Individuals on the Autistic Spectrum

Authors: R. Bawazir, P. Jones

Abstract:

Social Stories are widely used to teach social and communication skills or concepts to individuals on the autistic spectrum. This paper presents a theoretical framework for using Social Stories in conjunction with the creative arts. The paper argues that Bandura’s social learning theory can be used to explain the mechanisms behind Social Stories and the way they influence changes in response, while Gardner’s multiple intelligences theory can be used simultaneously to demonstrate the role of the creative arts in learning. By using Social Stories with the creative arts for individuals on the autistic spectrum, the aim is to meet individual needs and help individuals with autism to develop in different areas of learning and communication.

Keywords: Individuals on the autistic spectrum, social stories, creative arts, theoretical framework.

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813 Nanosize Structure Phase States in the Titanium Surface Layers after Electroexplosive Carburizing and Subsequent Electron Beam Treatment

Authors: Victor E. Gromov, Evgenii A. Budovskikh, Ludmila P. Bashchenko, Yurii F. Ivanov, Anna V. Ionina, Nina A. Soskova, Guoyi Tang

Abstract:

The peculiarities of the nanoscale structure-phase states formed after electroexplosive carburizing and subsequent electron-beam treatment of technically pure titanium surface in different regimes are established by methods of transmission electron diffraction microscopy and physical mechanisms are discussed. Electroexplosive carburizing leads to surface layer formation (40 m thickness) with increased (in 3.5 times) microhardness. It consists of β-titanium, graphite (monocrystals 100-150 nm, polycrystals 5-10 nm, amorphous particles 3-5nm), TiC (5-10 nm), β-Ti02 (2-20nm). After electron-beam treatment additionally increasing the microhardness the surface layer consists of TiC.

Keywords: nanoscale, phase, structure, titanium

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812 Applying Fuzzy Analytic Hierarchy Process for Evaluating Service Quality of Online Auction

Authors: Chien-Hua Wang, Meng-Ying Chou, Chin-Tzong Pang

Abstract:

This paper applies fuzzy AHP to evaluate the service quality of online auction. Service quality is a composition of various criteria. Among them many intangible attributes are difficult to measure. This characteristic introduces the obstacles for respondents on reply in the survey. So as to overcome this problem, we invite fuzzy set theory into the measurement of performance and use AHP in obtaining criteria. We found the most concerned dimension of service quality is Transaction Safety Mechanism and the least is Charge Item. Other criteria such as information security, accuracy and information are too vital.

Keywords: Fuzzy set theory, AHP, Online auction, Service quality

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811 Measuring Innovative and Entrepreneurial Networks Performance

Authors: Luís Farinha, João J. Ferreira

Abstract:

Nowadays innovation represents a challenge crucial to remaining globally competitive. This study seeks to develop a conceptual model aimed at measuring the dynamic interactions of the triple/quadruple helix, balancing innovation and entrepreneurship initiatives as pillars of regional competitiveness – the Regional Helix Scoreboard (RHS). To this aim, different strands of literature are identified according to their focus on specific regional competitiveness governance mechanisms. We put forward an overview of the state-of-the-art of research and is duly assessed in order to develop and propose a framework of analysis that enables an integrated approach in the context of collaborative dynamics. We conclude by presenting the RHS for the study of regional competitiveness dynamics, which integrates and associates different backgrounds and identifies a number of key performance indicators for research challenges.

Keywords: Entrepreneurship, KPIs, innovation, performance measurement, regional competitiveness, regional helix scoreboard.

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810 Concurrency without Locking in Parallel Hash Structures used for Data Processing

Authors: Ákos Dudás, Sándor Juhász

Abstract:

Various mechanisms providing mutual exclusion and thread synchronization can be used to support parallel processing within a single computer. Instead of using locks, semaphores, barriers or other traditional approaches in this paper we focus on alternative ways for making better use of modern multithreaded architectures and preparing hash tables for concurrent accesses. Hash structures will be used to demonstrate and compare two entirely different approaches (rule based cooperation and hardware synchronization support) to an efficient parallel implementation using traditional locks. Comparison includes implementation details, performance ranking and scalability issues. We aim at understanding the effects the parallelization schemes have on the execution environment with special focus on the memory system and memory access characteristics.

Keywords: Lock-free synchronization, mutual exclusion, parallel hash tables, parallel performance

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809 Motion Protection System Design for a Parallel Motion Platform

Authors: Dongsu Wu, Hongbin Gu

Abstract:

A motion protection system is designed for a parallel motion platform with subsided cabin. Due to its complex structure, parallel mechanism is easy to encounter interference problems including link length limits, joints limits and self-collision. Thus a virtual spring algorithm in operational space is developed for the motion protection system to avoid potential damages caused by interference. Simulation results show that the proposed motion protection system can effectively eliminate interference problems and ensure safety of the whole motion platform.

Keywords: Motion protection, motion platform, parallelmechanism, Stewart platform, collision avoidance.

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808 Design and Fabrication of a Column-Climber Robot (Koala Robot)

Authors: Maziar Sadeghi, Amir Moradi

Abstract:

This paper proposes a robot able to climb Columns. This robot is not dependent on the diameter and material of the columns. Some climbing robots have been designed up to now but Koala robot was designed and fabricated for climbing columns exclusively. Simple kinematics of climbing in the nature inspired us to design this robot. We used two linear mechanisms to grip the column. The gripper consists of a DC motor and a power screw mechanism with a linear bushing as a guide. This mechanism provides enough force to grip the column. In addition we needed an actuator for climbing the column; hence, two pneumatic jacks were used. All the mechanical parts were designed according to the exerted forces and operational condition. The prototype can be simply installed and controlled on the column by an inexperienced operator. This robot is intended for inspection and surveillance of pipes in oil industries and power poles in electric industries.

Keywords: Robot, Column-climber, Gripping mechanism, Koala.

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807 Temperature-Dependence of Hardness and Wear Resistance of Stellite Alloys

Authors: S. Kapoor, R. Liu, X. J. Wu, M. X. Yao

Abstract:

A group of Stellite alloys are studied in consideration of temperature effects on their hardness and wear resistance. The hardness test is conducted on a micro-hardness tester with a hot stage equipped that allows heating the specimen up to 650°C. The wear resistance of each alloy is evaluated using a pin-on-disc tribometer with a heating furnace built-in that provides the temperature capacity up to 450°C. The experimental results demonstrate that the hardness and wear resistance of Stellite alloys behave differently at room temperature and at high temperatures. The wear resistance of Stellite alloys at room temperature mainly depends on their carbon content and also influenced by the tungsten content in the alloys. However, at high temperatures the wear mechanisms of Stellite alloys become more complex, involving multiple factors. The relationships between chemical composition, microstructure, hardness and wear resistance of these alloys are studied, with focus on temperature effect on these relations.

Keywords: Stellite alloy, temperature, hardness, wear resistance

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806 Towards Better Understanding of the Concept of Tacit Knowledge – A Cognitive Approach

Authors: Ilkka J. Virtanen

Abstract:

Tacit knowledge has been one of the most discussed and contradictory concepts in the field of knowledge management since the mid 1990s. The concept is used relatively vaguely to refer to any type of information that is difficult to articulate, which has led to discussions about the original meaning of the concept (adopted from Polanyi-s philosophy) and the nature of tacit knowing. It is proposed that the subject should be approached from the perspective of cognitive science in order to connect tacit knowledge to empirically studied cognitive phenomena. Some of the most important examples of tacit knowing presented by Polanyi are analyzed in order to trace the cognitive mechanisms of tacit knowing and to promote better understanding of the nature of tacit knowledge. The cognitive approach to Polanyi-s theory reveals that the tacit/explicit typology of knowledge often presented in the knowledge management literature is not only artificial but totally opposite approach compared to Polanyi-s thinking.

Keywords: Cognitive science, explicit knowledge, knowledgemanagement, tacit knowledge.

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805 An Analysis of the Themes of Alcoholic Beverage Advertisements in Thailand after the Enactment of the Alcoholic Beverage Control Act of 2008

Authors: Arishai Akraudom

Abstract:

The objective of this research was to study the themes of alcoholic beverage advertisements in Thailand after the enactment of the 2008 Alcoholic Beverage Control Act. Data was collected through textual analysis of 35 television and cinema advertisements for alcoholic beverage products broadcast in Thailand. Nine themes were identified, seven of which were themes that had previously been used before the new law (i.e. power, competition, friendship, Thainess, success, romance and safety) and two of which were new themes (volunteerism and conservation) that were introduced as a form of adaptation and negotiation in response to the new law.

Keywords: Alcoholic Beverage Control Act 2008, Alcohol Advertising, Analysis of Themes, Narrative Structure, Health Communication.

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804 Analytical Study on Threats to Wetland Ecosystems and their Solutions in the Framework of the Ramsar Convention

Authors: Ehsan Daryadel, Farhad Talaei

Abstract:

Wetlands are one of the most important ecosystems on Earth. Nevertheless, various challenges threaten these ecosystems and disrupt their ecological character. Among these, the effects of human-based threats are more devastating. Following mass degradation of wetlands during 1970s, the Ramsar Convention on Wetlands (Ramsar, Iran, 1971) was concluded to conserve wetlands of international importance and prevent destruction and degradation of such ecosystems through wise use of wetlands as a mean to achieve sustainable development in all over the world. Therefore, in this paper, efforts have been made to analyze threats to wetlands and then investigate solutions in the framework of the Ramsar Convention. Finally, in order to operate these mechanisms, this study concludes that all states should in turn make their best effort to improve and restore global wetlands through preservation of environmental standards and close contribution and also through taking joint measures with other states effectively.

Keywords: Ramsar Convention, Threats, Wetland Ecosystems, Wise Use.

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803 WormHex: A Volatile Memory Analysis Tool for Retrieval of Social Media Evidence

Authors: Norah Almubairik, Wadha Almattar, Amani Alqarni

Abstract:

Social media applications are increasingly being used in our everyday communications. These applications utilise end-to-end encryption mechanisms which make them suitable tools for criminals to exchange messages. These messages are preserved in the volatile memory until the device is restarted. Therefore, volatile forensics has become an important branch of digital forensics. In this study, the WormHex tool was developed to inspect the memory dump files for Windows and Mac based workstations. The tool supports digital investigators by enabling them to extract valuable data written in Arabic and English through web-based WhatsApp and Twitter applications. The results confirm that social media applications write their data into the memory, regardless of the operating system running the application, with there being no major differences between Windows and Mac.

Keywords: Volatile memory, REGEX, digital forensics, memory acquisition

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802 Investigation on the Stability of Rock Slopes Subjected to Tension Cracks via Limit Analysis

Authors: W. Wu, S. Utili

Abstract:

Based on the kinematic approach of limit analysis, a full set of upper bound solutions for the stability of homogeneous rock slopes subjected to tension cracks are obtained. The generalized Hoek-Brown failure criterion is employed to describe the non-linear strength envelope of rocks. In this paper, critical failure mechanisms are determined for cracks of known depth but unspecified location, cracks of known location but unknown depth, and cracks of unspecified location and depth. It is shown that there is a nearly up to 50% drop in terms of the stability factors for the rock slopes intersected by a tension crack compared with intact ones. Tables and charts of solutions in dimensionless forms are presented for ease of use by practitioners.

Keywords: Hoek-Brown failure criterion, limit analysis, rock slope, tension cracks.

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801 Detection of New Attacks on Ubiquitous Services in Cloud Computing and Countermeasures

Authors: L. Sellami, D. Idoughi, P. F. Tiako

Abstract:

Cloud computing provides infrastructure to the enterprise through the Internet allowing access to cloud services at anytime and anywhere. This pervasive aspect of the services, the distributed nature of data and the wide use of information make cloud computing vulnerable to intrusions that violate the security of the cloud. This requires the use of security mechanisms to detect malicious behavior in network communications and hosts such as intrusion detection systems (IDS). In this article, we focus on the detection of intrusion into the cloud sing IDSs. We base ourselves on client authentication in the computing cloud. This technique allows to detect the abnormal use of ubiquitous service and prevents the intrusion of cloud computing. This is an approach based on client authentication data. Our IDS provides intrusion detection inside and outside cloud computing network. It is a double protection approach: The security user node and the global security cloud computing.

Keywords: Cloud computing, intrusion detection system, privacy, trust.

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800 Fatigue Behavior of Dissimilar Welded Monel400 and SS316 by FSW

Authors: Aboozar Aghaei, Kamran Dehghani

Abstract:

In the present work, the dissimilar Monel400 and SS316 were joined by Friction Stir Welding (FSW). The applied rotating speed was 400 rpm, whereas the traverse speed varied between 50 and 150 mm/min. At a constant rotating speed, the sound welds were obtained at the welding speeds of 50 mm/min and 100 mm/min. However, a groove-like defect was formed when the welding speed exceeded 100 mm/min. The mechanical properties of the joints were evaluated using tensile and fatigue tests. The fatigue strength of dissimilar FSWed specimens was higher than that of both Monel400 and SS316. To study the failure behavior of FSWed specimens, the fracture surfaces were analyzed using a Scanning Electron Microscope (SEM). The failure analysis indicates that different mechanisms may contribute to the fracture of welds. This was attributed to the dissimilar characteristics of dissimilar materials exhibiting different failure behaviors.

Keywords: Frictions stir welding, FSW, stainless steel, Monel400, mechanical properties.

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799 Fabrication and Characterization of Al/Methyl Orange/n-Si Heterojunction Diode

Authors: Muhammad Tahir, Muhammad H. Sayyad, Dil N. Khan, Fazal Wahab

Abstract:

Herein, the organic semiconductor methyl orange (MO), is investigated for the first time for its electronic applications. For this purpose, Al/MO/n-Si heterojunction is fabricated through economical cheap and simple “drop casting” technique. The currentvoltage (I-V) measurements of the device are made at room temperature under dark conditions. The I-V characteristics of Al/MO/n-Si junction exhibits asymmetrical and rectifying behavior that confirms the formation of diode. The diode parameters such as rectification ratio (RR), turn on voltage (Vturn on), reverse saturation current (I0), ideality factor (n), barrier height ( b f ), series resistance (Rs) and shunt resistance (Rsh) are determined from I-V curves using Schottky equations. These values of these parameters are also extracted and verified by applying Cheung’s functions. The conduction mechanisms are explained from the forward bias I-V characteristics using the power law.

Keywords: Electrical properties, Organic/inorganic heterojunction diode, Methyl Orange, Cheungs Functions

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798 Understanding Narrative Transformations of Ebola in Negotiations of Epidemic Risk

Authors: N. W. Paul, M. Banerjee

Abstract:

Discussing the nexus between global health policy and local practices, this article addresses the recent Ebola outbreak as a role model for narrative co-constructions of epidemic risk. We will demonstrate in how far a theory-driven and methodologically rooted analysis of narrativity can help to improve mechanisms of prevention and intervention whenever epidemic risk needs to be addressed locally in order to contribute to global health. Analyzing the narrative transformation of Ebola, we will also address issues of transcultural problem-solving and of normative questions at stake. In this regard, we seek to contribute to a better understanding of a key question of global health and justice as well as to the underlying ethical questions. By highlighting and analyzing the functions of narratives, this paper provides a translational approach to refine our practices by which we address epidemic risk, be it on the national, the transnational or the global scale.

Keywords: Ebola, Epidemic Risk, Medical Ethics, Medical Humanities.

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797 A Finite Element Model for Estimating Young-s Modulus of Carbon Nanotube Reinforced Composites Incorporating Elastic Cross-Links

Authors: Kaveh PourAkbar Saffar, Nima JamilPour, Ahmad Raeisi Najafi, Gholamreza Rouhi, Ahmad Reza Arshi, Abdolhossein Fereidoon

Abstract:

The presence of chemical bonding between functionalized carbon nanotubes and matrix in carbon nanotube reinforced composites is modeled by elastic beam elements representing covalent bonding characteristics. Neglecting other reinforcing mechanisms in the composite such as relatively weak interatomic Van der Waals forces, this model shows close results to the Rule of Mixtures model-s prediction for effective Young-s modulus of a Representative Volume Element of composite for small volume fractions (~1%) and high aspect ratios (L/D>200) of CNTs.

Keywords: Beam Element, Carbon Nanotube Reinforced Composite, Cross-link, Young's modulus.

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796 Governance through Cooperation: Solvit System and its Role in the Correct Implementation of the European Law by the National Public Administrations

Authors: C. Mătusescu, C. Mares, C. Gilia

Abstract:

The Implementation of the Union law faces major challenges today. If for a long period of time, the Community and the Union have persevered in their legislative vocation, now one can notice that this large legislative quantity has complicated the task of knowledge and of application the European standards. Under these circumstances, it became necessary, in order to give effectiveness to the European legislation, the development of some operational application criteria and the generation of some new implementation tools. The correct application of the European Union legislation by the national public administrations was considered by the European Commission as being crucial for further integration and proper functioning of the internal market. Among the initiatives launched in the past years to promote the exchange of good administrative practices in the correct application of European Union legislation, SOLVIT net has proved to be one of the most effective.

Keywords: Cooperation, European law, informal mechanisms, internal market, SOLVIT.

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795 Stability of Electrical Drives Supplied by a Three Level Inverter

Authors: M. S. Kelaiaia, H. Labar, S. Kelaiaia, T. Mesbah

Abstract:

The development of the power electronics has allowed increasing the precision and reliability of the electrical devices, thanks to the adjustable inverters, as the Pulse Wide Modulation (PWM) applied to the three level inverters, which is the object of this study. The authors treat the relation between the law order adopted for a given system and the oscillations of the electrical and mechanical parameters of which the tolerance depends on the process with which they are integrated (paper factory, lifting of the heavy loads, etc.).Thus, the best choice of the regulation indexes allows us to achieve stability and safety training without investment (management of existing equipment). The optimal behavior of any electric device can be achieved by the minimization of the stored electrical and mechanical energy.

Keywords: Multi level inverter, PWM, Harmonics, oscillation, control.

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794 Diagnosis of Hate Schemas in Prisoners with Antisocial Personality Disorder (ASPD)

Authors: Barbara Gawda

Abstract:

The aim of this study is to show innovative techniques that describe the effectiveness of individuals diagnosed with antisocial personality disorders (ASPD). The author presents information about hate schemas regarding persons with ASPD and their understanding of the role of hate. The data of 60 prisoners with ASPD, 40 prisoners without ASPD, and 60 men without antisocial tendencies, has been analyzed. The participants were asked to describe their hate inspired by a photograph. The narrative discourse was analyzed, the three groups were compared. The results show the differences between the inmates with ASPD, those without ASPD, and the controls. The antisocial individuals describe hate as an ambivalent feeling with low emotional intensity, i.e., actors (in stories) are presented more as positives than as partners. They use different mechanisms to keep them from understanding the meaning of the emotional situation. The schema's characteristics were expressed in narratives attributed to high Psychopathy.

Keywords: Antisocial personality disorder, Emotional narratives, Hate schemas, Psychopathy

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793 Evaluating Service Quality of Online Auction by Fuzzy MCDM

Authors: Wei-Hsuan Lee, Chien-Hua Wang, Chin-Tzong Pang

Abstract:

This paper applies fuzzy set theory to evaluate the service quality of online auction. Service quality is a composition of various criteria. Among them many intangible attributes are difficult to measure. This characteristic introduces the obstacles for respondent in replying to the survey. So as to overcome this problem, we invite fuzzy set theory into the measurement of performance. By using AHP in obtaining criteria and TOPSIS in ranking, we found the most concerned dimension of service quality is Transaction Safety Mechanism and the least is Charge Item. Regarding to the most concerned attributes are information security, accuracy and information.

Keywords: AHP, Fuzzy set theory, TOPSIS, Online auction, Servicequality

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792 Tailoring the Sharpness of Tungsten Nanotips via Laser Irradiation Enhanced Etching in KOH

Authors: D. D. Wang, J.C. Lam, Z. H. Mai

Abstract:

Controlled modification of appropriate sharpness for nanotips is of paramount importance to develop novel materials and functional devices at a nanometer resolution. Herein, we present a reliable and unique strategy of laser irradiation enhanced physicochemical etching to manufacture super sharp tungsten tips with reproducible shape and dimension as well as high yields (~80%). The corresponding morphology structure evolution of tungsten tips and laser-tip interaction mechanisms were systematically investigated and discussed using field emission scanning electron microscope (SEM) and physical optics statistics method with different fluences under 532 nm laser irradiation. This work paves the way for exploring more accessible metallic tips applications with tunable apex diameter and aspect ratio, and, furthermore, facilitates the potential sharpening enhancement technique for other materials used in a variety of nanoscale devices.

Keywords: Tungsten tip sharpening, Laser irradiation, Physicochemical etching, Light-matter interaction.

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791 A Competitiveness Analysis of the Convention Tourism of China's Macao Special Administrative Region

Authors: Linda, Sau-ling Lai

Abstract:

This paper explored the use of Importance- Performance Analysis in assessing the competitiveness of China-s Macao Special Administrative Region as a city for international conventions. Determinants of destination choice for convention tourists are grouped under three factors, namely the convention factor, the city factor and the tourism factor. Attributes of these three factors were studied through a survey with the convention participants and exhibitors of Macao SAR. Results indicate that the city boasts of strong traditional tourist attractions and infrastructure, but is deficient in specialized convention experts and promotion mechanisms. A reflection on the findings suggests that an urban city such as the Macao SAR can co-develop its the convention and the traditional tourism for a synergistic effect. With proper planning and co-ordination, both areas of the city-s tourism industry will grow as they feed off each other.

Keywords: Convention Tourism, Importance-Performance Analysis, Destination Selection, Competitiveness

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790 Fast Prototyping for Atmospheric Plasma Sources Integration into Air Hand Dryers

Authors: Abdel Majid Kassir, Joël Sonnard, Ludovic Roulin, Martine Baudin, Gilles Courret, Wolfram Manuel Brück

Abstract:

Motivated by the current COVID-19 pandemic and the need to find alternative methods to contain and battle it, the purpose of this innovative project is to conceive a disinfection module equipped with a cold atmospheric plasma source. Such a plasma source was developed for a potential integration into pulsed air hand dryers. This type of plasma is known for its ability to generate reactive oxygen and nitrogen species that initiate bio-molecular reactions involved in bacterial and viral deactivation mechanisms. This study shows how additive manufacturing helped accelerate the prototyping of a nozzle allowing the preservation of the plasma flow from circulation cells and external interferences in the discharge’s surrounding.

Keywords: Cold atmospheric plasma, hand disinfection, hand sanitization, bacterial and viral deactivation, plasma chemistry.

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789 Micromechanical Modeling of Fiber-Matrix Debonding in Unidirectional Composites

Authors: M. Palizvan, M. T. Abadi, M. H. Sadr

Abstract:

Due to variations in damage mechanisms in the microscale, the behavior of fiber-reinforced composites is nonlinear and difficult to model. To make use of computational advantages, homogenization method is applied to the micro-scale model in order to minimize the cost at the expense of detail of local microscale phenomena. In this paper, the effective stiffness is calculated using the homogenization of nonlinear behavior of a composite representative volume element (RVE) containing fiber-matrix debonding. The damage modes for the RVE are considered by using cohesive elements and contacts for the cohesive behavior of the interface between fiber and matrix. To predict more realistic responses of composite materials, different random distributions of fibers are proposed besides square and hexagonal arrays. It was shown that in some cases, there is quite different damage behavior in different fiber distributions. A comprehensive comparison has been made between different graphs.

Keywords: Homogenization, cohesive zone model, fiber-matrix debonding, RVE.

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788 Perception of Farmers and Agricultural Professionals on Changes in Productivity and Water Resources in Ethiopia

Authors: D. Mojo, Y. Todo, P. Matous

Abstract:

In this paper, perceptions of actors on changes in crop productivity, quantity and quality of water, and determinants of their perception are analyzed using descriptive statistics and ordered logit model. Data collected from 297 Ethiopian farmers and 103 agricultural professionals from December 2009 to January 2010 are employed. Results show that the majority of the farmers and professionals recognized decline in water resources, reasoning climate changes and soil erosion as some of the causes. However, there is a variation in views on changes in productivity. The household asset, education level, age and geographical positions are found to affect farmers- perception on changes in crop productivity. But, the study underlines that there is no evidence that farmers- economic status, age, or education level affects recognition of degradation of water resources. Thus, more focus shall be given on providing them different coping mechanisms and alternative resource conserving technologies than educating about the problems.

Keywords: Agricultural Sustainability, Ethiopia, Perception, Productivity, Water Resources

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