Search results for: electromagnetic forming

Authors: Sachin Mahajan, Ghizal Ansari

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TeO2-WO3-Li2O glass doped erbium ions (1mol %) and embedded silver nanoparticles( Ag NPs) has successfully been prepared by melt quenching technique and increasing the heat-treatment duration. The amorphous nature of the glass is determined by X-ray diffraction method, and the presences of silver nanoparticles are confirmed using Transmission Electron Microscopy analysis. TEM image reveals that the Ag NPs are dispersed homogeneously with average size 18 nm. From the UV-Vis absorption spectra, the surface plasmon resonance (SPR) peaks are detected at 550 and 578 nm. Under 980 nm excitation wavelengths, enhancement of red upconversion fluorescence and near-infrared broadband emission around 1550nm of Er3+ ions doped tellurite glasses containing Ag NPs have been observed. The observed enhancement of Er3+ emission is mainly attributed to the local field effects of Ag NPs causes an intensified electromagnetic field around NPs. For observed enhancement involved mechanisms are discussed.

Keywords: erbium ions, silver nanoparticle, surface plasmon resonance, upconversion emission

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Authors: Marcos Bosques-Perez, Walter Izquierdo, Harold Martin, Liangdon Deng, Josue Rodriguez, Thony Yan, Mercedes Cabrerizo, Armando Barreto, Naphtali Rishe, Malek Adjouadi

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Aerial imagery is a powerful tool when it comes to analyzing temporal changes in ecosystems and extracting valuable information from the observed scene. It allows us to identify and assess various elements such as objects, structures, textures, waterways, and shadows. To extract meaningful information, multispectral cameras capture data across different wavelength bands of the electromagnetic spectrum. In this study, the collected multispectral aerial images were subjected to principal component analysis (PCA) to identify independent and uncorrelated components or features that extend beyond the visible spectrum captured in standard RGB images. The results demonstrate that these principal components contain unique characteristics specific to certain wavebands, enabling effective object identification and image segmentation.

Keywords: big data, image processing, multispectral, principal component analysis

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Authors: A. El Amri, M. El Yakhloufi Haddou, A. Khamlichi

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The numerical simulation based on the Finite Element Method (FEM) is widely used in academic institutes and in the industry. It is a useful tool to predict many phenomena present in the classical manufacturing forming processes such as fracture. But, the results of such numerical model depend strongly on the parameters of the constitutive behavior model. The influences of thermal and mechanical loads cause damage. The temperature and strain rate dependent materials’ properties and their modelling are discussed. A Johnson-Cook Model of damage has been selected for the numerical simulations. Virtual software called the ABAQUS 6.11 is used for finite element analysis. This model was introduced in order to give information concerning crack initiation during thermal and mechanical loads.

Keywords: thermo-mechanical fatigue, failure, numerical simulation, fracture, damage

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Authors: Abbas Al-Refaie

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The research examines the factors that affect customer churn (CC) in the Jordanian telecom industry. A total of 700 surveys were distributed. Cluster analysis revealed three main clusters. Results showed that CC and customer satisfaction (CS) were the key determinants in forming the three clusters. In two clusters, the center values of CC were high, indicating that the customers were loyal and SC was expensive and time- and energy-consuming. Still, the mobile service provider (MSP) should enhance its communication (COM), and value added services (VASs), as well as customer complaint management systems (CCMS). Finally, for the third cluster the center of the CC indicates a poor level of loyalty, which facilitates customers churn to another MSP. The results of this study provide valuable feedback for MSP decision makers regarding approaches to improving their performance and reducing CC.

Keywords: cluster analysis, telecom industry, switching cost, customer churn

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Authors: Thong Lantharthong, Nattchote Rugthaicharoencheep, Att Phayomhom

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This paper presents the electrical effect of two neighboring distribution substation during the construction phase. The size of auxiliary grounding grid have an effect on entire grounding system. The bigger the size of auxiliary grounding grid, the lower the GPR and maximum touch voltage, with the exception that when the two grids are unconnected, i.e. the bigger the size of auxiliary grounding grid, the higher the maximum step voltage. The results in this paper could be served as design guideline of grounding system, and perhaps remedy of some troublesome grounding grids in power distribution’s system. Modeling and simulation is carried out on the Current Distribution Electromagnetic interference Grounding and Soil structure (CDEGS) program. The simulation results exhibit the design and analysis of power system grounding and perhaps could be set as a standard in grounding system design and modification in distribution substations.

Keywords: grounding system, touch voltage, step voltage, safety criteria

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Authors: Talha Sareshwala

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The purpose of this research paper is to help entrepreneurs build an environment of trust, transparency and accountability necessary for fostering long term investment, financial stability and business integrity and to guide future Entrepreneurs into a promising future. The study presents a broader review on Corporate Governance, starting from its definition and antecedents. This is the most important aspect of ethical business. In fact, the 3 main pillars of corporate governance are: Transparency; Accountability; Security. The combination of these 3 pillars in running a company successfully and forming solid professional relationships among its stakeholders, which includes key managerial employees and, most important, the shareholders This paper is sharing an experience how an entrepreneur can act as a catalyst while ensuring them that ethics and transparency do pay in business when followed in true spirit and action.

Keywords: business, entrepreneur, ethics, governance, transparency.

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Authors: Muazzam A. Khan, Muhammad Wasim

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Vehicular adhoc network (VANET) Cars for network (VANET) allowing vehicles to talk to each other, which is committed to building a strong network of mobile vehicles is technical. In VANETs vehicles are equipped with special devices that can get and share info with the atmosphere and other vehicles in the network. Depending on this data security and safety of the vehicles can be enhanced. Broadcast routing is dispersion of any audio or visual medium of mass communication scattered audience distribute audio and video content, but usually using electromagnetic radiation (waves). The lack of server or fixed infrastructure media messages in VANETs plays an important role for every individual application. Broadcast Message VANETs still open research challenge and requires some effort to come to good solutions. This paper starts with a brief introduction of VANET, its applications, and the law of the message-trends in this network starts. This work provides an important and comprehensive study of reliable broadcast routing in VANET scenario.

Keywords: vehicular ad-hoc network , broadcasting, networking protocols, traffic pattern, low intensity conflict

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Authors: Ahmet Afyon, Dursun Yagiz, Kutret Gezer, Aziz Turkoglu

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This study was conducted in order to contribute to Turkey’s macrofungus flora. The fungi samples forming the study material were collected from Afyonkarahisar province in 2009. The photos of mushrooms were taken in their own habitats. Their tastes, odors and clours were determined. These samples were brought to the laboratory. The microscopic properties of fungi were determined in the laboratory. The fungi were identified according to their macroscopic and microscopic features with the help of written literature. The identified macrofungi are; Limacella furnace (Letell.) E.-J. Gilbert from the Amanitaceae familia, Marasmiellus vaiillantii (Pers.) Singer from Omphalotaceae familia, Mycena flos-nivium Kuhner from Mycenaceae familia. With this study, it has been contributed to Turkey’s macrofungi flora and biodiversity.

Keywords: Afyonkarahisar, macrofungi, records, Turkey

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Authors: Ahmed Nour El Islam Ayad, Wafa Krika, Abdelghani Ayad, Moulay Larab, Houari Boudjella, Farid Benhamida

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The purpose of this study is to evaluate the magnetic emission of underground electric cable of high voltage, because these power lines generate electromagnetic interaction with other objects near to it. The aim of this work shows a numerical simulation of the magnetic field of buried 400 kV line in three cases: permanent and transient states of short circuit and the last case with the presence of the harmonics at different positions as a function of time variation, with finite element resolution using Comsol Multiphysics software. The results obtained showed that the amplitude and distribution of the magnetic flux density change in the transient state and the presence of harmonics. The results of this work calculate the magnetic field generated by the underground lines in order to evaluate and know their impact on ecology and health.

Keywords: underground, electric power cables, cables crossing, harmonic, emission

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Authors: Shahzad Hassan, Kamran Saeed

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People are always in search of Wi-Fi hotspots because Internet is a major demand nowadays. But like all other technologies, there is still room for improvement in the Wi-Fi technology with regards to the speed and quality of connectivity. In order to address these aspects, Harald Haas, a professor at the University of Edinburgh, proposed what we know as the Li-Fi (Light Fidelity). Li-Fi is a new technology in the field of wireless communication to provide connectivity within a network environment. It is a two-way mode of wireless communication using light. Basically, the data is transmitted through Light Emitting Diodes which can vary the intensity of light very fast, even faster than the blink of an eye. From the research and experiments conducted so far, it can be said that Li-Fi can increase the speed and reliability of the transfer of data. This paper pays particular attention on the assessment of the performance of this technology. In other words, it is a 5G technology which uses LED as the medium of data transfer. For coverage within the buildings, Wi-Fi is good but Li-Fi can be considered favorable in situations where large amounts of data are to be transferred in areas with electromagnetic interferences. It brings a lot of data related qualities such as efficiency, security as well as large throughputs to the table of wireless communication. All in all, it can be said that Li-Fi is going to be a future phenomenon where the presence of light will mean access to the Internet as well as speedy data transfer.

Keywords: communication, LED, Li-Fi, Wi-Fi

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Authors: Shigeyuki Haruyama, I Made Gatot Karohika, Akinori Sato, Didik Nurhadiyanto, Ken Kaminishi

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Contact width and contact stress are important design parameters for optimizing corrugated metal gasket performance based on elastic and plastic contact stress. In this study, we used a three-layer metal gasket with Al, Cu, Ni as the outer layer, respectively. A finite element method was employed to develop simulation solution. The gasket model was simulated by using two simulation stages which are forming and tightening simulation. The simulation result shows that aluminum with tangent modulus, Ehal = Eal/150 has the highest slope for contact width. The slope of contact width for plastic mode gasket was higher than the elastic mode gasket.

Keywords: contact width, contact stress, layer, metal gasket, corrugated, simulation

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Authors: Lukáš Klein, Karel Žídek

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Hyperspectral imaging counts among the most frequently used multidimensional sensing methods. While there are many approaches to capturing a hyperspectral data cube, optical compression is emerging as a valuable tool to reduce the setup complexity and the amount of data storage needed. Hyperspectral compressive imagers have been created in the past; however, they have primarily focused on relatively narrow sections of the electromagnetic spectrum. A broader spectral study of samples can provide helpful information, especially for applications involving the harmonic generation and advanced material characterizations. We demonstrate a broadband hyperspectral microscope based on the single-pixel camera principle. Captured spatially encoded data are processed to reconstruct a hyperspectral cube in a combined visible and near-infrared spectrum (from 400 to 2500 nm). Hyperspectral cubes can be reconstructed with a spectral resolution of up to 3 nm and spatial resolution of up to 7 µm (subject to diffraction) with a high compressive ratio.

Keywords: compressive imaging, hyperspectral imaging, near-infrared spectrum, single-pixel camera, visible spectrum

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Authors: Lula Chou

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At the turn of the 20th century, Chicago faced a large real estate boom and technological advances through industrialization that led to the rise of the commercial skyscrapers. Focusing on creating a Midwest regional character and new functional meanings of structural art, architects like Sullivan, Adler, Burnham, and Root dominated the first Chicago School of Architecture. After they spearheaded the arena of modern skyscrapers, other cities in the United States like New York soon followed the trend. While battling with eclecticism and Beaux-Arts beliefs in decorative style, Chicago architects adapted Classical monumentality into their modern expressions that emphasized organicism and functionalism. With various experiments of material possibilities in the steel-framed constructions, Chicago architecture succeeded in forming humanitarian aesthetics alongside fulfilling functional requirements of the new generation.

Keywords: Chicago school, modernity, monumentality, skyscrapers, Sullivan

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Authors: I. Touaїbia, E. Azzag, O. Narjes

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Power supply networks are growing continuously and their reliability is getting more important than ever. The complexity of the whole network comprises numerous components that can fail and interrupt the power supply for the end user. Underground distribution systems are normally exposed to permanent faults, due to specific construction characteristics. In these systems, visual inspection cannot be performed. In order to enhance service restoration, accurate fault location techniques must be applied. This paper describes the different faults that affect the underground distribution system of SONELGAZ (National Society of Electricity and Gas of Algeria), and cable fault location procedure with impulse reflection method (TDR), based in the analyses of the cable response of the electromagnetic impulse, allows cable fault prelocation. The results are obtained from real test in the underground distribution feeder from electrical network of energy distribution company of Souk-Ahras, in order to know the influence of cable characteristics in the types and frequency of faults.

Keywords: distribution networks, fault location, TDR, underground cable

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Authors: Johannes J. Schneider, Mathias S. Weyland, Peter Eggenberger Hotz, William D. Jamieson, Oliver Castell, Alessia Faggian, Rudolf M. Füchslin

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Agglomerations of polydisperse systems of spherical particles are created in computer simulations using a simplified stochastic-hydrodynamic model: Particles sink to the bottom of the cylinder, taking into account gravity reduced by the buoyant force, the Stokes friction force, the added mass effect, and random velocity changes. Two types of particles are considered, with one of them being able to create connections to neighboring particles of the same type, thus forming a network within the agglomeration at the bottom of a cylinder. Decreasing the fraction of these particles, a percolation transition occurs. The critical regime is determined by investigating the maximum cluster size and the percolation susceptibility.

Keywords: binary system, maximum cluster size, percolation, polydisperse

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Authors: Arthur Baraov

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Nearly all rocket and spacecraft propulsion concepts in existence today can be linked one way or the other to one of the two ancient warfare devices: the gun and the sling. Chemical, thermoelectric, ion, nuclear thermal and electromagnetic rocket engines – all fall into the first group which, for obvious reasons, can be categorized as “hot” space propulsion concepts. Space elevator, orbital tower, rolling satellite, orbital skyhook, tether propulsion and gravitational assist – are examples of the second category which lends itself for the title “cold” space propulsion concepts. The “hot” space propulsion concepts skyrocketed – literally and figuratively – from the naïve ideas of Jules Verne to the manned missions to the Moon. On the other hand, with the notable exception of gravitational assist, hardly any of the “cold” space propulsion concepts made any progress in terms of practical application. Why is that? This article aims to show that the right answer to this question has the potential comparable by its implications and practical consequences to that of transition from Jules Verne’s stillborn and impractical conceptions of space flight to cogent and highly fertile ideas of Konstantin Tsiolkovsky and Yuri Kondratyuk.

Keywords: propulsion, rocket, rollet, spacecraft

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Authors: Arzu Javadova

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The complex of sedimentary deposits that make up the West Turkmen Basin is almost completely hidden under the Quaternary formations. The most ancient deposits emerging on the surface in some places are the deposits of the Red Color Suite of the Pliocene. Miocene deposits are exposed only at the Western end of the Kopet Dag. The main object of stratigraphic, including micropaleontological studies, were the deposits of the Quaternary and Pliocene forming marine and coastal structures. The identified stratigraphic units have certain characteristic Ostracod complexes. The fauna of the Ostracod acquires special significance in the stratification of Neogene and Quaternary deposits. Ostracods of the Neogene, Pliocene and Quaternary deposits of the West Turkmen depression are represented by a large part of the species common in the corresponding deposits of Azerbaijan and Iran.

Keywords: neogene, quaternary, turkmenistan, south caspian basin, ostracoda, foraminifera, biostratigraphy, paleontology

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Authors: Anil Kumar Pandey

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A compact planar monopole antenna with dual-band operation suitable for wireless local area network (WLAN) application is presented in this paper. The antenna occupies an overall area of 18 ×12 mm². The antenna is fed by a coplanar waveguide (CPW) transmission line and it combines two folded strips, which radiates at 2.4 and 5.2 GHz. In the proposed antenna, by optimally selecting the antenna dimensions, dual-band resonant modes with a much wider impedance matching at the higher band can be produced. Prototypes of the obtained optimized design have been simulated using EM solver. The simulated results explore good dual-band operation with -10 dB impedance bandwidths of 50 MHz and 2400 MHz at bands of 2.4 and 5.2 GHz, respectively, which cover the 2.4/5.2/5.8 GHz WLAN operating bands. Good antenna performances such as radiation patterns and antenna gains over the operating bands have also been observed. The antenna with a compact size of 18×12×1.6 mm³ is designed on an FR4 substrate with a dielectric constant of 4.4.

Keywords: CPW antenna, dual-band, electromagnetic simulation, wireless local area network (WLAN)

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Authors: Jiajia Peng

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Tinnitus is one of the common symptoms of ear diseases and is characterized by an abnormal perception of sound without external stimulation. Tinnitus is agony and seriously affects the life of the general population by approximately 1%. Sleep disturbance is a common problem in patients with tinnitus. Lack of sleep will lead to the accumulation of metabolites in the brain and cannot be cleared in time. These substances enhance sympathetic nerve reactivity in the auditory system, resulting in tinnitus occurrence or aggravation. Then, tinnitus may aggravate sleep disturbance, thus forming a vicious circle. Through a systematic review of the relevant literature, we summarize the research on tinnitus and sleep. Although the results suggest that tinnitus is often accompanied by sleep disturbance, the impact of unfavorable sleep habits on tinnitus is not clear. In particular, the relationships between sleep behaviors and other chronic diseases have been revealed. To reduce the incidence rate of tinnitus, clinicians should pay attention to the relevance between different sleep behaviors and tinnitus.

Keywords: tinnitus, sleep, sleep factor, sleep behavior

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Authors: Eric Huang, Coleman DeLude, Justin Romberg, Saibal Mukhopadhyay, Madhavan Swaminathan

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High performance computing (HPC) based emulators can be used to model the scattering from multiple stationary and moving targets for RADAR applications. These emulators rely on the RADAR Cross Section (RCS) of the targets being available in complex scenarios. Representing the RCS using tables generated from electromagnetic (EM) simulations is often times cumbersome leading to large storage requirement. This paper proposed a spherical harmonic based anisotropic scatterer model to represent the RCS of complex targets. The problem of finding the locations and reflection profiles of all scatterers can be formulated as a linear least square problem with a special sparsity constraint. This paper solves this problem using a modified Orthogonal Matching Pursuit algorithm. The results show that the spherical harmonic based scatterer model can effectively represent the RCS data of complex targets.

Keywords: RADAR, RCS, high performance computing, point scatterer model

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Authors: Ming Su, Ziqiang Mu

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This paper proposes a synthesis method for nonuniform linear antenna arrays that combine Gaussian process regression (GPR) and genetic algorithm (GA). In this method, the GPR model can be used to calculate the array radiation pattern in the presence of mutual coupling effects, and then the GA is used to optimize the excitations and locations of the elements so as to generate the desired radiation pattern. In this paper, taking a 9-element nonuniform linear array as an example and the desired radiation pattern corresponding to a Chebyshev distribution as the optimization objective, optimize the excitations and locations of the elements. Finally, the optimization results are verified by electromagnetic simulation software CST, which shows that the method is effective.

Keywords: nonuniform linear antenna arrays, GPR, GA, mutual coupling effects, active element pattern

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Authors: Daurenbek Kuleimenov, Elmira Otar

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Market institutions extension within transit societies contributes to constituting the new type of middle class and households livelihood strategies. The middle class households as an example of prosperity in many cases encourage the ordinary ones to do the same economic actions. Therefore, practices of using market institutions by middle class households in transit societies, which are mostly characterized by huge influence of traditional attitudes, can carry habitual features for the whole society. Market institutions consumption habit of the middle class households makes them trendsetters of economic habits of other households while adapting to the market economy. Moreover different social-economic positions of households lead them to different consuming results such as worsening or improving household economy due to indebtedness.

Keywords: middle class, households, market institutions, transition

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Authors: Ashoke Priyadarshana Premananda

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As per the suggestions of previously conducted research in Counseling Psychology, the necessity of forming culture- friendly approaches has been strongly emphasized by a number of scholars in the field. In response to that, Multicultural-model of Buddhist Based Cognitive Behavioral Therapy (MMBCBT) has been formed as a culture-friendly therapeutic approach to address psychological disturbances (depression) in late adulthood. Elderly population in the world is on the rise by leaps and bounds, and forming a culture-based therapeutic model which is blended with Buddhist teachings has been the major objective of the study. Buddhist teachings and cultural applications, which were mapped onto Cognitive Behavioral Therapy (CBT) in the West, ultimately resulted in MMBCBT. Therefore, MMBCBT is a blend of cultural therapeutic techniques and the essence of certain Buddhist teachings extracted from five crucial suttas, which include CBT principles. In the process of mapping, MeghiyaSutta, GirimānandaSutta, SallekhaSutta, DvedhāvitakkaSutta, and Vitakka- SaṇṭhānaSutta have been taken into consideration mainly because of their cognitive behavioral content. The practical components of Vitakka- Saṇṭhānasutta (Aññanimittapabbaṃ) and Sallekhasutta (SallekhaPariyāya and CittuppādaPariyāya) have been used in the model while mindfulness of breathing was also carried out with the participants. Basically, multi-cultural therapeutic approaches of MMBCBT aim at modifying behavior (behavioral modification), whereas the rest is centered to the cognitive restructuring process. Therefore, MMBCBT is endowed with Behavioral Therapy (BT) and Cognitive Therapy(CT). In order to find out the validation of MMBCBT as a newly formed approach, it was then followed by mixed research (quantitative and qualitative research) with a sample selected from the elderly population following the purposive sampling technique. 40 individuals were selected from three elderly homes as per the purposive sampling technique. Elderly people identified to be depressed via Geriatric Depression Scale underwent MMBCBT for two weeks continuously while action research was being conducted simultaneously. Additionally, a Focus Group interview was carried out to support the action research. As per the research findings, people who identified depressed prior to the exposure to MMBCBT were found to be showing positive changes after they were exposed to the model. “Paired Sample t test” showed that the Multicultural Model of Buddhist based Cognitive Behavioral Therapy reduced depression of elderly people (The mean value (x̄) of the sample (level of depression) before the model was 10.7 whereas the mean value after the model was 7.5.). Most importantly, MMBCBT has been found to be effectively used with people from all walks of life despite religious diversities.

Keywords: buddhist psychotherapy, cognitive behavioral therapy in buddhism, counseling in cultural context, gerontology, and buddhism

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Authors: Zhang Yu, Ding Yi

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The discussion about elements of cultural heritage and their relevance among the ancient villages is comparably insufficient. The protection work is strongly influenced by touristic development and cultural gimmick, resulting in low protection efficiency and many omissions. Historical villages as the cultural settlement patterns bear a large number of heritage relics. They were regionally scattered with a clear characteristic of gathering. First of all, this study proposes the association and similarities of the forming mechanism between four historic cultural villages in Mian Mountain. Secondly, the study reveals that these villages own the strategic pass, underground passage, and the mountain barrier. Thirdly, based on the differentiated characteristics of villages’ space, the study discusses about the integrated conservation from three levels: the regional heritage conservation, the cultural line shaping, and the featured brand building.

Keywords: conservation, fortress, historical villages, Mian Moutain

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Authors: K. Urukundu, K. A. Aravind, Pradeep M. Nirgude, K. Sandhya

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Transmission of bulk power over a long distance through HVDC transmission lines is gaining importance. This is because the transfer of bulk power through HVDC, from generating stations to load centers over long distances is more economical. However, these HVDC transmission lines create environmental and interference effects under the right of way of the line due to the ionization of the surrounding atmosphere in the vicinity of HVDC lines. The measurement of ground-level electric field and ionic current density is essential for the evaluation of human effects due to electromagnetic interference of the HVDC transmission line. In this paper, experimental laboratory results of the ground-level electric field under the miniature model of 800 kV monopole HVDC line of length 8 meters are presented in lateral configuration with different heights of the conductor from the ground plane. The results are compared with the simulated test results obtained through Finite Element based software.

Keywords: bundle, conductor, hexagonal, transmission line, ground-level electric field

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Authors: Poonam Yadav, Dong Bok Lee

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In this study, the Ti-6Al-4V alloy was isothermally and cyclically oxidized at 800oC for 40 hours in air, and its oxidation behavior was characterized in terms of its oxidation rate, scaling rate, and scale spallation tendency. The isothermal oxidation tests indicated that Ti-6Al-4V oxidized fast and almost linearly, forming thick oxide scales. However, the scales that formed during isothermal oxidation were adherent. The cyclic oxidation tests indicated that the scales that formed on Ti-6Al-4V were highly susceptible to spallation owing to the large growth stress arisen and the thermal stress imposed during thermal cyclings. The formed scales frequently delaminated into several pieces owing to the excessive stress aroused by the repetitive thermal shock. Particularly, excessive oxidation and heavy spallation occurred at the edge of Ti-6Al-4V during cyclic oxidation.

Keywords: cyclic, isothermal, oxidation, spallation

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Authors: Indra Bahadur Bhandari, Narayan Panthi, Ishwar Koirala, Devendra Adhikari

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We have used a theoretical model based on the assumption of compound formation in binary alloys to study the thermodynamic, microscopic, and surface properties of Bi-Pb and In-Pb liquid alloys. A review of the phase diagrams for these alloys shows that one of the stable complexes for Bi-Pb liquid alloy is BiPb3; also, that InPb is a stable phase in liquid In-Pb alloys. Using the same interaction parameters that are fitted for the free energy of mixing, we have been able to compute the bulk and thermodynamic properties of the alloys. From our observations, we are able to show that the Bi-Pb liquid alloy exhibits compound formation over the whole concentration range and the In-Pb alloys undergo phase separation. With regards to surface properties, Pb segregates more to the surface in In-Pb alloys than in Bi-Pb alloys. The viscosity isotherms have a positive deviation from ideality for both Bi-Pb and In-Pb alloys.

Keywords: asymmetry, Bi-Pb, deviation, In-Pb, interaction parameters

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Authors: Yang Luo, Chang Nyung Kim

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This study numerically analyzes a steady-state, three-dimensional liquid-metal magnetohydrodynamic flows in a conduit with multiple channels under a uniform magnetic field. The geometry of the conduit is of a four-parallel-channels system including one inflow channel and three outflow channels. The liquid-metal flows in the inflow channel, then turns 1800 in the transition segment, finally flows into three different outflow channels simultaneously. This kind of channel system can induce counter flow and co-flow, which is rarely investigated before. The axial velocity in the side layer near the first partitioning wall, which is located between the inflow channel and the first outflow channel, is the highest. ‘M-shaped’ velocity profiles are obtained in the side layers of the inflow and outflow channels. The interdependency of the current, fluid velocity, pressure, electric potential is examined in order to describe the electromagnetic characteristics of the liquid-metal flows.

Keywords: liquid-metal, multiple channels, magnetic field, magnetohydrodynamic

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Authors: Hyeong-Jin Kim, Jong Kook Lee

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Zirconia has biological, mechanical and optical properties, so, it used as a dental implant material in human body. But, it is difficult to form directly bonding with living tissues after the procedure and induces the falling away from implanted parts of the body. To improve this phenomenon, it is essential to increase the surface roughness of zirconia implants and induce a forming-ability of strong bonds. In this study, we performed a room temperature spray coating on zirconia specimen to obtain a highly roughened zirconia surface. To get optimal surface roughness, we controlled the distance between the nozzle and the substrate, coating times and powder condition. Bonding microstructure, surface roughness, and chemical composition of the coating layer were observed by SEM, XRD and roughness tester.

Keywords: implant, aerosoldeposition, zirconia, dental

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Authors: Grzegorz Raniszewski, Zbigniew Kolacinski, Lukasz Szymanski, Slawomir Wiak, Lukasz Pietrzak, Dariusz Koza

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One of the most promising area for carbon nanotubes (CNTs) application is medicine. One of the most devastating diseases is cancer. Carbon nanotubes may be used as carriers of a slowly released drug. It is possible to use of electromagnetic waves to destroy cancer cells by the carbon nanotubes (CNTs). In our research we focused on thermal ablation by ferromagnetic carbon nanotubes (Fe-CNTs). In the cancer cell hyperthermia functionalized carbon nanotubes are exposed to radio frequency electromagnetic field. Properly functionalized Fe-CNTs join the cancer cells. Heat generated in nanoparticles connected to nanotubes warm up nanotubes and then the target tissue. When the temperature in tumor tissue exceeds 316 K the necrosis of cancer cells may be observed. Several techniques can be used for Fe-CNTs synthesis. In our work, we use high-temperature methods where arc-discharge is applied. Low-temperature systems are microwave plasma with assisted chemical vapor deposition (MPCVD) and hybrid physical-chemical vapor deposition (HPCVD). In the arc discharge system, the plasma reactor works with a pressure of He up to 0,5 atm. The electric arc burns between two graphite rods. Vapors of carbon move from the anode, through a short arc column and forms CNTs which can be collected either from the reactor walls or cathode deposit. This method is suitable for the production of multi-wall and single-wall CNTs. A disadvantage of high-temperature methods is a low purification, short length, random size and multi-directional distribution. In MPCVD system plasma is generated in waveguide connected to the microwave generator. Then containing carbon and ferromagnetic elements plasma flux go to the quartz tube. The additional resistance heating can be applied to increase the reaction effectiveness and efficiency. CNTs nucleation occurs on the quartz tube walls. It is also possible to use substrates to improve carbon nanotubes growth. HPCVD system involves both chemical decomposition of carbon containing gases and vaporization of a solid or liquid source of catalyst. In this system, a tube furnace is applied. A mixture of working and carbon-containing gases go through the quartz tube placed inside the furnace. As a catalyst ferrocene vapors can be used. Fe-CNTs may be collected then either from the quartz tube walls or on the substrates. Low-temperature methods are characterized by higher purity product. Moreover, carbon nanotubes from tested CVD systems were partially filled with the iron. Regardless of the method of Fe-CNTs synthesis the final product always needs to be purified for applications in medicine. The simplest method of purification is an oxidation of the amorphous carbon. Carbon nanotubes dedicated for cancer cell thermal ablation need to be additionally treated by acids for defects amplification on the CNTs surface what facilitates biofunctionalization. Application of ferromagnetic nanotubes for cancer treatment is a promising method of fighting with cancer for the next decade. Acknowledgment: The research work has been financed from the budget of science as a research project No. PBS2/A5/31/2013

Keywords: arc discharge, cancer, carbon nanotubes, CVD, thermal ablation

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