Search results for: shear force

Authors: Peter R. Alfieri

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The principal aim of this research and presentation is to give global and personal perspective of the migratory diaspora and how it is perceived by a substantial majority that relies on the media’s portrayal of migratory movements. Since its Greek origins the word “diaspora” has taken on several connotations, but none has surpassed its use in regard to the human element; because since before the dawn of history, man has had to struggle for survival. That survival was a struggle against the elements and other natural enemies, but none as tenacious and relentless as other men. Many have used the term diaspora to describe the spread of certain ethnic groups resulting in new generations in new places; but has the human diaspora been as haphazard as that of spores? The quest for survival has spawned migrations that are not quite that simple, even though it has several similarities to plant spores or dandelion seeds flying throughout the atmosphere. Man kind has constantly migrated in search of food, shelter, and safety. When they were able to find food and shelter, they would inform others who would venture to the new place. Information, whether through word of mouth, written material, or visual communications, has been a moving force in man’s life; and it spurred migrants in their quest for better environments. Today we pride ourselves in being able to communicate instantly with anyone anywhere in the world, and we are privileged to see most of what is happening in the world thanks to the highly developed modern media. Is Media a “wind/force” instrumental in propelling the diaspora throughout the world? The media has been the tool that has incentive many migratory, but unfortunately it is also the means responsible for many misconceptions regarding migrants and their hosts. Has the Media presented an unbiased view of the migrant or has it been the means that generated negative or prejudiced views of the migrant and, perhaps, the host environment? Some examples were easily seen in 19th century the United States where they advertised the following, “Help needed, Irish need not apply”. How do immigrants circumvent latent barriers that are not as obvious as the ones just mentioned? Some immigrants return home and have children that decide to emigrate. It is a perpetual cycle in the search for self-improvement. The stories that are brought back might be inspiration for the new generation of emigrants. Poverty, hunger, and political turmoil spur most migrations. The majority learn from others or through the media about certain destinations that will provide one or several opportunities to improve their existence. Many of those migrants suffer untold hardships to succeed. When they succeed, they provide a great incentive for their children to obtain an education or skill that will insure them a better life. Although the new environment may contribute greatly to a successful career, most immigrants do not forget their own struggle. They see the media’s portrayal of other migrants from all over the globe. Some try to communicate to others the true feelings of despair felt by immigrants, because they are all brothers and sisters in the perennial struggle for a better life. “HOPE” for a better life drives the immigrant toward the unknown and it has helped overcome the obstacles that present themselves challenging every newcomer. Hope and perseverance strengthen the resolve of the migrant in his struggle to survive.

Keywords: media, migration, heath, education, obstacles

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Authors: Evgeniya Orlova, Dmitriy Feoktistov, Geniy Kuznetsov

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Spreading of a droplet over a solid substrate is a key phenomenon observed in the following engineering applications: thin film coating, oil extraction, inkjet printing, and spray cooling of heated surfaces. Droplet cooling systems are known to be more effective than film or rivulet cooling systems. It is caused by the greater evaporation surface area of droplets compared with the film of the same mass and wetting surface. And the greater surface area of droplets is connected with the curvature of the interface. Location of the droplets on the cooling surface influences on the heat transfer conditions. The close distance between the droplets provides intensive heat removal, but there is a possibility of their coalescence in the liquid film. The long distance leads to overheating of the local areas of the cooling surface and the occurrence of thermal stresses. To control the location of droplets is possible by changing the roughness, structure and chemical composition of the surface. Thus, control of spreading can be implemented. The most important characteristic of spreading of droplets on solid surfaces is a dynamic contact angle, which is a function of the contact line speed or capillary number. However, there is currently no universal equation, which would describe the relationship between these parameters. This paper presents the results of the experimental studies of water droplet spreading on metal substrates with different surface roughness. The effect of the droplet growth rate and the surface roughness on spreading characteristics was studied at low capillary numbers. The shadow method using high speed video cameras recording up to 10,000 frames per seconds was implemented. A droplet profile was analyzed by Axisymmetric Drop Shape Analyses techniques. According to change of the dynamic contact angle and the contact line speed three sequential spreading stages were observed: rapid increase in the dynamic contact angle; monotonous decrease in the contact angle and the contact line speed; and form of the equilibrium contact angle at constant contact line. At low droplet growth rate, the dynamic contact angle of the droplet spreading on the surfaces with the maximum roughness is found to increase throughout the spreading time. It is due to the fact that the friction force on such surfaces is significantly greater than the inertia force; and the contact line is pinned on microasperities of a relief. At high droplet growth rate the contact angle decreases during the second stage even on the surfaces with the maximum roughness, as in this case, the liquid does not fill the microcavities, and the droplet moves over the “air cushion”, i.e. the interface is a liquid/gas/solid system. Also at such growth rates pulsation of liquid flow was detected; and the droplet oscillates during the spreading. Thus, obtained results allow to conclude that it is possible to control spreading by using the surface roughness and the growth rate of droplets on surfaces as varied factors. Also, the research findings may be used for analyzing heat transfer in rivulet and drop cooling systems of high energy equipment.

Keywords: contact line speed, droplet growth rate, dynamic contact angle, shadow system, spreading

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Authors: Panagiotis Svarnas, Polykarpos Papadopoulos

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Atmospheric-pressure cold plasmas continue to gain increasing interest for various applications due to their unique properties, like cost-efficient production, high chemical reactivity, low gas temperature, adaptability, etc. Numerous designs have been proposed for these plasmas production in terms of electrode configuration, driving voltage waveform and working gas(es). However, in order to exploit most of the advantages of these systems, the majority of the designs are based on dielectric-barrier discharges (DBDs) either in filamentary or glow regimes. A special category of the DBD-based atmospheric-pressure cold plasmas refers to the so-called plasma jets, where a carrier noble gas is guided by the dielectric barrier (usually a hollow cylinder) and left to flow up to the atmospheric air where a complicated hydrodynamic interplay takes place. Although it is now well established that these plasmas are generated due to ionizing waves reminding in many ways streamer propagation, they exhibit discrete characteristics which are better mirrored on the terms 'guided streamers' or 'plasma bullets'. These 'bullets' travel with supersonic velocities both inside the dielectric barrier and the channel formed by the noble gas during its penetration into the air. The present work is devoted to the interpretation of the electro-hydrodynamic effects that take place downstream of the dielectric barrier opening, i.e., in the noble gas-air mixing area where plasma bullet propagate under the influence of local electric fields in regions of variable noble gas concentration. Herein, we focus on the role of the local space charge and the residual ionic charge left behind after the bullet propagation in the gas flow field modification. The study communicates both experimental and numerical results, coupled in a comprehensive manner. The plasma bullets are here produced by a custom device having a quartz tube as a dielectric barrier and two external ring-type electrodes driven by sinusoidal high voltage at 10 kHz. Helium gas is fed to the tube and schlieren photography is employed for mapping the flow field downstream of the tube orifice. Mixture mass conservation equation, momentum conservation equation, energy conservation equation in terms of temperature and helium transfer equation are simultaneously solved, leading to the physical mechanisms that govern the experimental results. Namely, we deal with electro-hydrodynamic effects mainly due to momentum transfer from atomic ions to neutrals. The atomic ions are left behind as residual charge after the bullet propagation and gain energy from the locally created electric field. The electro-hydrodynamic force is eventually evaluated.

Keywords: atmospheric-pressure plasmas, dielectric-barrier discharges, schlieren photography, electro-hydrodynamic force

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Authors: V. Yu. Shungin, A. V. Popov

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At present, one of the main tasks of Russian shipbuilding yards is implementation of new technologies and replacement of main process equipment. In particular, conventional bending technologies with dies are being replaced with resource-saving methods of rotation (roller) banding. Such rolling bending is performed by multiple rolling of a plat in special bending rollers. Studies, conducted in JSC SSTC, allowed developing a theory of rotation bending, methods for calculation of process parameters, requirements to roller presses and bending accessories. This technology allows replacing old and expensive presses with new cheaper roller ones, having less power consumption and bending force. At first, roller presses were implemented in ship repair, however now they are widely employed at major shipbuilding yards. JSC SSTC develops bending technology and carries out design, manufacturing and delivery of roller presses.

Keywords: bending/straightening machines, rotational bending, ship hull structures, multifunctional bending

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Authors: Monika Singh

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A carbon nanotube thin film coated on dielectric interface is employed to produce THz surface plasma wave (SPW). The carbon nanotube has its plasmon frequency in the THz range. The SPW field falls off away from the metal film both inside the dielectric as well as in free space. An amplitude modulated laser pulse normally incident, from free space on slow wave structure, exert a modulation frequency ponderomotive force on the free electrons of the CNT film and resonantly excite the THz surface plasma wave at the modulation frequency. Carbon nanotube based plasmonic nano-structure materials provides potentially more versatile approach to tightly confined surface modes in the THz range in comparison to noble metals.

Keywords: surface plasmons, surface waves, thin films, THz radiation

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Authors: Elisabet Liljeblad, Tomas Karlsson, Torbjorn Sundberg, Anita Kullen

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The magnetospheric magnetic field data from the MESSENGER spacecraft is investigated to establish the presence of ultra-low frequency (ULF) waves in connection to 131 previously observed nonlinear Kelvin-Helmholtz waves (KHWs) at Mercury. Distinct ULF signatures are detected in 44 out of the 131 magnetospheric traversals prior to or after observing a KHW. In particular, 39 of these 44 ULF events are highly coherent at the frequency of maximum power spectral density. The waves observed at the dayside, which appears mainly at the duskside and naturally following the KHW occurrence asymmetry, are significantly different to the events behind the dawn-dusk terminator and have the following distinct wave characteristics: they oscillate clearly in the perpendicular (azimuthal) direction to the mean magnetic field with a wave normal angle more in the parallel than the perpendicular direction, increase in absolute ellipticity with distance from noon, are almost exclusively right-hand polarized, and are observed mainly for frequencies in the range 0.02-0.04 Hz. These results indicate that the dayside ULF waves are likely to shear Alfvén waves driven by KHWs at the magnetopause, which in turn manifests the importance of the Kelvin-Helmholtz instability in terms of mass transport throughout the Mercury magnetosphere.

Keywords: ultra-low frequency waves, kelvin-Helmholtz instability, magnetospheric processes, mercury, messenger, energy and momentum transfer in planetary environments

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Authors: Sa’ed Abed, Mohammad H. Al Shayeji, Ovais Ahmed, Sahel Alouneh

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Session Initiation Protocol (SIP) is a signaling layer protocol for building, adjusting and ending sessions among participants including Internet conferences, telephone calls and multimedia distribution. SIP facilitates user movement by proxying and forwarding requests to the present location of the user. In this paper, we provide a formal Specification and Description Language (SDL) and Message Sequence Chart (MSC) to model and define the Internet Engineering Task Force (IETF) SIP protocol and its sample services resulted from informal SIP specification. We create an “Abstract User Interface” using case analysis so that can be applied to identify SIP services more explicitly. The issued sample SIP features are then used as case scenarios; they are revised in MSCs format and validated to their corresponding SDL models.

Keywords: modeling, MSC, SDL, SIP, validating

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Authors: K. M. Kheiralla, M. A. Ali, M. Y. Abdelgalil, N. E. Mohamed, G. Boutsis

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The present study focus on integrated geophysical surveys carried out in the mineralization zone in Erkowit region, Eastern Sudan to determine the extensions of the potential ore deposits on the topographically high hilly area and under the cover of alluvium along the nearby wadi and to locate other occurrences if any. The magnetic method (MAG) and the electrical resistivity tomography (ERT) were employed for the survey. Eleven traverses were aligned approximately at right angles to the general strike of the rock formations. The disseminated sulfides are located on the alteration shear zone which is composed of granitic and dioritic highly ferruginated rock occupying the southwestern and central parts of the area, this was confirmed using thin and polished sections mineralogical analysis. The magnetic data indicates low magnetic values for wadi sedimentary deposits in its southern part of the area, and high anomalies which are suspected as gossans due to magnetite formed during wall rock alteration consequent to mineralization. The significant ERT images define low resistivity zone as traced as sheared zones which may associated with the main loci of ore deposition. The study designates that correlation of magnetic and ERT anomalies with lithology are extremely useful in mineral exploration due to variations in some specific physical properties of rocks.

Keywords: ERT, magnetic, mineralization, Red Sea, Sudan

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Authors: Iris Käppler, Paul Matthäi, Chokri Cherif

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In the scope of application of technical textiles, Non-Crimp Fabrics are increasingly used. In general, NCF exhibit excellent load bearing properties, but caused by the manufacturing process, there are some remaining disadvantages which have to be reduced. Regarding to this, a novel technique of processing NCF was developed substituting the binding-thread by an adhesive. This stitch-free method requires new manufacturing concept as well as new basic methods to prove adhesion of glue at fibres and textiles. To improve adhesion properties and the wettability of carbon-fibres by the adhesive, oxyfluorination was used. The modification of carbon-fibres by oxyfluorination was investigated via scanning electron microscope, X-ray photo electron spectroscopy and single fibre tensiometry. Special tensile tests were developed to determine the maximum force required for detachment.

Keywords: non-crimp fabric, adhesive, stitch-free, high-performance fibre

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Authors: Hsien Hao Teng

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This study uses numerical simulation to analyze the aerodynamic characteristics of the 53-degree Lambda wing with a sweep angle and mainly discusses the numerical simulation results and physical characteristics of the wall y+. Use the commercial software Fluent to execute Mach number 0.15; when the angle of attack attitude is between 0 degrees and 27 degrees, the physical characteristics of the overall aerodynamic force are analyzed, especially when the fluid separation and vortex structure changes are discussed under the condition of high angle of attack, it will affect The instability of pitching moment. In the numerical calculation, the use of wall y+ and turbulence model will affect the prediction of vortex generation and the difference in structure. The analysis results are compared with experimental data to discuss the trend of the aerodynamic characteristics of the Lambda wing.

Keywords: lambda wing, wall function, turbulence model, computational fluid dynamics

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Authors: Andri Hidayat, Zufialdi Zakaria, Raden Irvan Sophian

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Batam city within next five years are expected to experience water crisis. Sei Gong dam which is located in the Sijantung village, Galang District, Batam City, Riau Islands Province is one of 13 dams that will be built to solve the problems of raw water crisis in the Batam city. The purpose of this study are to determine the condition of engineering geology around Sei Gong Dam area, knowing the value of the soil bearing capacity and recommended pile foundation, and knowing the characteristics of the soil consolidation as one of the factors that affect the incidence of soil subsidence. Based on calculations for shallow foundation in general - soil shear condition and local - soil condition indicates that the highest value in ultimate soil bearing capacity (qu) for each depth was in the square foundations at two meters depth. The zonations of shallow foundation of the research area are divided into five zones, they are bearing capacity zone <10 ton/m2, bearing capacity zone 10-15 ton/m2, bearing capacity zone 15-20 ton/m2, bearing capacity zone 20-25 ton/m2, and bearing capacity zone >25 ton/m2. Based on the parameters of soil engineering analysis, Sei Gong Dam areas at the middle part has a higher value for land subsidence.

Keywords: ultimate bearing capacity, type of foundation, consolidation, land subsidence, Batam

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Authors: Walid El Kamash

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Sand columns (or granular piles) can be employed as soil strengthening for flexible constructions such as road embankments, oil storage tanks in addition to multistory structures. The challenge of embedding the sand columns in soft soil is that the surrounding soft soil cannot avail the enough confinement stress in order to keep the form of the sand column. Therefore, the sand columns which were installed in such soil will lose their ability to perform needed load-bearing capacity. The encasement, besides increasing the strength and stiffness of the sand column, prevents the lateral squeezing of sands when the column is installed even in extremely soft soils, thus enabling quicker and more economical installation. This paper investigates the improvement in load capacity of the sand column by encasement through a comprehensive parametric study using the 3-D finite difference analysis for the soft clay of soil in Egypt. Moreover, the study was extended to include a comparison study between encased sand column and Deep Mixed columns (DM). The study showed that confining the sand by geosynthetic resulted in an increment of shear strength. That result paid the attention to use encased sand stone rather than deep mixed columns due to relative high permeability of the first material.

Keywords: encased sand column, Deep mixed column, numerical analysis, improving soft soil

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Authors: Enrique Castañeda, Tomas Hernadez, Mario Ulloa

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Recent studies related to submarine pipelines under high pressure, temperature and buried, forces us to make bibliographical and documentary research to make us of references applicable to our problem. This paper presents an experimental methodology to the implementation of results obtained in a scale model, bibliography soil mechanics and finite element simulation. The model consists of a tank of 0.60 x 0.90 x 0.60 basis equipped high side windows, tires and digital hardware devices for measuring different variables to be applied to the model, where the mechanical properties of the soil are determined, simulation of drag a pipeline buried in a non-cohesive seafloor of the Gulf of Mexico, estimate the failure surface and application of each of the variables for the determination of mechanical elements.

Keywords: static friction coefficient, maximum passive force resistant soil, normal, tangential stress

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Authors: Niloufar Ghoreishi, Ali Nekouzadeh

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The stability of the flight during maneuvering and in response to probable perturbations is one of the most essential features of an aircraft that should be analyzed and designed for. In this study, we derived the non-linear governing equations of aircraft dynamics during the climb/descend phase and simulated a model aircraft. The corresponding force and moment dimensionless coefficients of the model and their variations with elevator angle and other relevant aerodynamic parameters were measured experimentally. The short-period mode and phugoid mode response were simulated by solving the governing equations numerically and then compared with the desired stability parameters for the particular level, category, and class of the aircraft model. To meet the target stability, a controller was designed and used. This resulted in significant improvement in the stability parameters of the flight.

Keywords: flight stability, phugoid mode, short period mode, climb phase, damping coefficient

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Authors: Mahtab Assadian, Mohd Hasbullah Idris, Mostafa Rezazadeh Shirdar, Mohammad Mahdi Taheri, ‎S. Izman

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Corrosion behaviour and surface roughness of magnesium substrate were investigated after NaOH pretreatment in different concentrations (1, 5, and 10 molar) and duration of (10 min, 30 min, 1 h, 3 h, 6 h and 24 h). Creation of Mg(OH)2 barrier layer after pretreatment enhanced corrostion resistance as well as wettability of substrate surface. Characterization including Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) was conducted to detect the existence of this barrier layer. Surface roughness and wettability of substrate was evaluated using atomic force microscopy (AFM) and contact angle measurement respectively. It is found that magnesium treated by 1M NaOH for 30 min reveals higher corrosion resistance and lower water contact angle of substrate surface. In addition, this investigation indicates that pH value of SBF solution is strongly influenced by different time and concentration of alkaline pretreatment.

Keywords: magnesium, NaOH pretreatment, corrosion resistance, wettability

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Authors: Abhit Kumar

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The world is full of master slave Telemanipulator where the doctor’s masters the console and the surgical arm perform the operations, i.e. these robots are passive robots, what the world needs to focus is that in use of these passive robots we are acquiring doctors for operating these console hence the utilization of the concept of robotics is still not fully utilized ,hence the focus should be on active robots, Auto Surgical-Emissive Hand use the similar concept of active robotics where this anthropomorphic hand focuses on the autonomous surgical, emissive and scanning operation, enabled with the vision of 3 way emission of Laser Beam/-5°C < ICY Steam < 5°C/ TIC embedded in palm of the anthropomorphic hand and structured in a form of 3 way disc. Fingers of AS-EH (Auto Surgical-Emissive Hand) as called, will have tactile, force, pressure sensor rooted to it so that the mechanical mechanism of force, pressure and physical presence on the external subject can be maintained, conversely our main focus is on the concept of “emission” the question arises how all the 3 non related methods will work together that to merged in a single programmed hand, all the 3 methods will be utilized according to the need of the external subject, the laser if considered will be emitted via a pin sized outlet, this radiation is channelized via a thin channel which further connect to the palm of the surgical hand internally leading to the pin sized outlet, here the laser is used to emit radiation enough to cut open the skin for removal of metal scrap or any other foreign material while the patient is in under anesthesia, keeping the complexity of the operation very low, at the same time the TIC fitted with accurate temperature compensator will be providing us the real time feed of the surgery in the form of heat image, this gives us the chance to analyze the level, also ATC will help us to determine the elevated body temperature while the operation is being proceeded, the thermal imaging camera in rooted internally in the AS-EH while also being connected to the real time software externally to provide us live feedback. The ICY steam will provide the cooling effect before and after the operation, however for more utilization of this concept we can understand the working of simple procedure in which If a finger remain in icy water for a long time it freezes the blood flow stops and the portion become numb and isolated hence even if you try to pinch it will not provide any sensation as the nerve impulse did not coordinated with the brain hence sensory receptor did not got active which means no sense of touch was observed utilizing the same concept we can use the icy stem to be emitted via a pin sized hole on the area of concern ,temperature below 273K which will frost the area after which operation can be done, this steam can also be use to desensitized the pain while the operation in under process. The mathematical calculation, algorithm, programming of working and movement of this hand will be installed in the system prior to the procedure, since this AS-EH is a programmable hand it comes with the limitation hence this AS-EH robot will perform surgical process of low complexity only.

Keywords: active robots, algorithm, emission, icy steam, TIC, laser

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Authors: Ahsan Ali Khan

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During past few years, researchers are emphasizing more on the need of safety in construction industry. This need of safety is an important issue in developing countries. As due to development they are facing huge construction growth. This research is done to evaluate labor safety condition in construction industry of Pakistan. The research carried out through questionnaire survey at different construction sites. Useful data are gathered from these sites which then factor analyzed resulting in five factors. These factors reflect that most of the workers are aware of the safety need, but they divert this responsibility towards management and claim that the work is more essential for management instead of safety. Moreover, those work force which is unaware of safety state that there is lack of any training and guidance from upper management which lead to many unfavorable events on construction sites. There is need of implementation safety activities by management like training, formulation of rules and policies. This research will be helpful to divert management attention towards safety need so they will make efforts for safety of their manpower—the workers.

Keywords: labor's safety, management role, Pakistan, safety factors

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Authors: Ehsan Sadie

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The use of steel braces in concrete structures has been considered by researchers in recent decades due to its easy implementation, economics and the ability to create skylights in braced openings compared to shear wall openings as well as strengthening weak concrete structures to earthquakes. The purpose of this article is to improve and strengthen concrete structures with steel bracing. In addition, cases such as different numbers of steel braces in different openings of concrete structures and interaction between concrete frames and metal braces have been studied. In this paper, by performing static nonlinear analysis and examining ductility, the relative displacement of floors, examining the performance of samples, and determining the coefficient of behavior of composite frames (concrete frames with metal bracing), the behavior of reinforced concrete frames is compared with frame without bracing. The results of analyzes and studies show that the addition of metal bracing increases the strength and stiffness of the frame and reduces the ductility and lateral displacement of the structure. In general, the behavior of the structure against earthquakes will be improved.

Keywords: behavior coefficient, bracing, concrete structure, convergent bracing, earthquake, linear static analysis, nonlinear analysis, pushover curve

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Authors: Jongho Park, Taekyun Kim, Jungbhin You, Sungnam Hong, Sun-Kyu Park

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The deterioration of the reinforced concrete is continuously accelerated due to aging of the reinforced concrete, enlargement of the structure, increase if the self-weight due to the manhattanization and cracking due to external force. Also, due to the abnormal climate phenomenon, cracking of reinforced concrete structures is accelerated. Therefore, research on the Textile Reinforced Concrete (TRC) which replaced reinforcement with textile is under study. However, in previous studies, adhesion performance to single yarn was examined without parameters, which does not reflect the effect of fiber twisting and concrete strength. In the present paper, the effect of concrete strength and embedded length on 2400tex (gram per 1000 meters) and 640tex textile were investigated. The result confirm that the increasing compressive strength of the concrete did not affect the pullout strength. However, as the embedded length increased, the pullout strength tended to increase gradually, especially at 2400tex with more twists.

Keywords: textile, TRC, pullout, strength, embedded length, concrete

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Authors: Tirtha Raj Dhakal, Brian Davidson, Bob Farquharson

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Institutional design is important if water resources are to be managed efficiently. In Nepal, the supply of water in both farmer- and agency-managed irrigation systems is inefficient because of the weak institutional frameworks. This type of inefficiency is linked with collective problems such as non-excludability of irrigation water, inadequate recognition of property rights and externalities. Irrigation scheme surveys from Nepal as well as existing literature revealed that the Nepalese irrigation sector is facing many issues such as low cost recovery, inadequate maintenance of the schemes and inefficient allocation and utilization of irrigation water. The institutional practices currently in place also fail to create/force any incentives for farmers to use water efficiently and to pay for its use. This, thus, compels the need of refined institutional framework that can address the collective problems and improve irrigation efficiency.

Keywords: agency-managed, cost recovery, farmer-managed, institutional design

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Authors: David Rafetseder, Walter Bauer, Florian Poltschak, Wolfgang Amrhein

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A flat double-stator linear induction machine (DSLIM) with a short squirrel-cage mover is designed for high thrust force at moderate speed < 5m/s. The performance and motor parameters are determined on the basis of a 2D time-transient simulation with the finite element (FE) software Maxwell 2015. Design guidelines and transformation rules for space vector theory of the LIM are presented. Resulting thrust calculated by flux and current vectors is compared with the FE results showing good coherence and reduced noise. The parameters of the equivalent circuit model are obtained.

Keywords: equivalent circuit model, finite element model, linear induction motor, space vector theory

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Authors: Dahmani Aziz, Mekdad Yousra

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The intellectual capital is an important source of profitability and the main supporter of the competitive where this study examines the contribution of expenditure on intellectual capital in the performance of industrial enterprises Algerian, and through a case study Sonatrach as the most important industrial enterprises in Algeria and the driving force of the Algerian economy. It has been the use of value-added intellectual coefficient (VAIC) in measuring the contribution of intellectual capital and analyzing data Sonatrach during the period from the year 2001 until the year 2012, and test the validity of hypotheses using Stepwise Regression model through the SPSS statistical software, and the study has proved the existence of a positive relationship between spending on human capital and financial performance and a stronger degree relationship between the structural capital and economic performance.

Keywords: industrial enterprise, intellectual capital, performance, economy of Algeria, spending

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Authors: S. Kamil Akin, Turgut Acikara

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In recent years the world and our country has experienced several explosion events occurred due to terrorist attacks and accidents. In these explosion events many people have lost their lives and many buildings have been damaged. If structures were designed taking the blast loads into account, these results may not have happened or the casualties would have been less. In this thesis analysis of the protection walls have been conducted to prevent the building damage from blast loads. These analyzes was carried out for two different types of wall, concrete and reinforced concrete. Analyses were carried out on four different thicknesses of each wall element. In each wall element the stresses and displacements of the exposed surface due to the detonation charge has been calculated. The limit shear stress and displacement of the wall element according to their material properties has been taken into account. As the result of the analyses the standoff distances and TNT equivalent amount has been determined. According to equivalent TNT amounts and standoff distances the structural response of the protective wall elements has been observed. These structural responses have been observed by ABAQUS finite element package. Explosion loads were brought into effect to the protective wall element models by using the ABAQUS / CONWEP.

Keywords: blast loading, blast wave, TNT equivalent method, CONWEP, finite element analysis, detonation

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Authors: Etienne Gatera

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Many studies have been conducted on SDT. Most of them focus on developed countries because of influencing factors such as; education, health, labor force, female labor force participation, industrialization, urbanization and migration. However, this thesis project paper aims to assess the impact of the total fertility rate (TFR) on the trends of the SDR in Rwanda. We will mainly be based in Rwanda after the 1994 genocide. Rwanda is located in East Africa, with approximately 13 million inhabitants. Thus, after the 1994 Tutsi genocide. The population growth rate exploded out of control with 6.17 children per woman in 1995. However, it's declined to 4.2 in 2014-2015 and declining to 4.1% in 2019-2020. Respectively with 3.4 children per woman in urban areas and 4.3 in rural areas. According to the National Institute of Statistics of Rwanda. Rwanda's population is expected to continue to grow for the rest of the century and reach 33.35 million people in 2099, with 2.1 children per woman in 2050. However, this project document aims to demonstrate the impact of the TFR on SDT trends in Rwanda. Thus, the decline in the TFR in Rwanda began with the introduction of family planning practices, which now account for 47.5% in 2019. Childbearing with three children for rural women compared to two children in the city, the increase in Divorce and separation caused by the behavior called "Kuza n'ijoro" or "coming at night" similar to cohabitation in developed countries. The decline in remarriage is caused by single mothers behavior who prefer to raise their children rather than remarry. Therefore, the study used probability sampling with (Stratified random sampling) method with a survey questionnaire of 1067 respondents in the 5 Districts (3 in rural areas and two in urban areas), with the target group of women Age between 15-49. The study demonstrated that the age of marriage in rural areas is two years higher than in urban areas. Divorce is more common in urban is with 6.2% with 5.2% in rural areas. However, separation is more common in rural areas than in urban areas, with a lower rate of 3%, due to the higher system called "Kuza n'ijoro" or "come at night", similar to cohabitation in developed countries. The study revealed that more than 85% of divorced people prefer to remain single, which confirms the low remarriage rate. Childbearing has started to decrease, especially for young singles in urban areas, due to the economic situation, with national statistics showing that unemployment in the youth community is still 16% higher. Therefore, the study concluded by confirming the hypothesis based on the results of the TFR indicators such as marriage, remarriage, divorce, separation, divorce, Kuza n'ijoro, childbearing] and abortion. The study consists of four sections, an introduction and background, a review of the literature, a description of the data and methodology, an analysis of the data, discussion results and a conclusion.

Keywords: Kuza n'ijoro, Rwanda, second demographic transition (SDT), total fertility rate (TFR)

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Authors: Y. Sefir, Z. Aziz, S. Cherid, Z. F. Meghoufel, F. Bendahama, S. Terkhi, B. Bouadjemi. A. Zitouni S. Bentata

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This work is to study the effect of the variation of structural parameters on the band structure in the quasiperiodic Fibonacci superlattices AlxGa1-xAs/GaAs using the formalism of the transfer matrix and Airy function. Our results show that increasing the width of Fibonacci’s wells of allows to the confinement of subminibands with a widening of minigaps, this causes a consistent and coherent fragmentation. The barrier thickness of Fibonacci bf acts on the width of subminibands by controlling the interaction force between neighboring eigenstates. Its increase gives rise to singularly extended states. The barrier height Fibonacci Vf permit to control the degree of structural disorder in these structures. The variation of these parameters permits the design of laser with modulated wavelength.

Keywords: transmission coefficient – Quasiperiodic superlattices- singularly localized and extended states- structural parameters- Laser with modulated wavelength

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Authors: M. Zain, Thaung H. Aung, Naveed Anwar

Abstract:

During the service life, a structure may experience extreme loading conditions. The current study proposes a new methodology that covers the effect of uncertainty involved in gravity loadings on key structural elements of new and complex structures by emphasizing on a very realistic assumption that allows the 'Performance-Based Assessment' to be executed on the structure against the gravity loadings. The methodology does not require the complete removal of an element, instead, it permits the incremental reduction in the capacity of key structural elements and preserves the same stiffness of the member in each case of capacity loss. To demonstrate the application of the proposed methodology, a 13 story complex structure is selected that comprises of a diverse structural configuration. The results ensure the structural integrity against the applied gravity loadings, as well as the effectiveness of the proposed methodology.

Keywords: force-deformation relationship, gravity loading, incremental capacity reduction, multi-linear plastic link element, SAP2000, stiffness

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Authors: Naod Mekonnen Anega

Abstract:

The very objective of this paper was to empirically identify technology tailored determinants to the adoption and adoption intensity (extent of use) of agricultural water management technologies in Meda Welabu Woreda, Oromia regional state, Ethiopia. Meda Welabu Woreda which is one of the administrative Woredas of the Oromia regional state was selected purposively as this Woreda is one of the Woredas in the region where small scale irrigation practices and the use of agricultural water management technologies can be found among smallholders. Using the existence water management practices (use of water management technologies) and land use pattern as a criterion Genale Mekchira Kebele is selected to undergo the study. A total of 200 smallholders were selected from the Kebele using the technique developed by Krejeie and Morgan. The study employed the Logit and Tobit models to estimate and identify the economic, social, geographical, household, institutional, psychological, technological factors that determine adoption and adoption intensity of water management technologies. The study revealed that while 55 of the sampled households are adopters of agricultural water management technology the rest 140 were non adopters of the technologies. Among the adopters included in the sample 97% are using river diversion technology (traditional) with traditional canal while the rest 7% percent are using pond with treadle pump technology. The Logit estimation reveled that while adoption of river diversion is positively and significantly affected by membership to local institutions, active labor force, income, access to credit and land ownership, adoption of treadle pump technology is positively and significantly affected by family size, education level, access to credit, extension contact, income, access to market, and slope. The Logit estimation also revealed that whereas, group action requirement, distance to farm, and size of active labor force negative and significantly influenced adoption of river diversion, age and perception has negatively and significantly influenced adoption decision of treadle pump technology. On the other hand, the Tobit estimation reveled that while adoption intensity (extent of use) of agricultural water management is positively and significantly affected by education, credit, and extension contact, access to credit, access to market and income. This study revealed that technology tailored study on adoption of Agricultural water management technologies (AWMTs) should be considered to indentify and scale up best agricultural water management practices. In fact, in countries like Ethiopia, where there is difference in social, economic, cultural, environmental and agro ecological conditions even within the same Kebele technology tailored study that fit the condition of each Kebele would help to identify and scale up best practices in agricultural water management.

Keywords: water management technology, adoption, adoption intensity, smallholders, technology tailored approach

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Authors: Athmane Bakhta, Sebastien Leclaire, David Vidal, Francois Bertrand, Mohamed Cheriet

Abstract:

This work presents a new three-dimensional variational model proposed for the simulation of ink seepage into paper sheets at the fiber level. The model, inspired by the Hising model, takes into account a finite volume of ink and describes the system state through gravity, cohesion, and adhesion force interactions. At the mesoscopic scale, the paper substrate is modeled using a discretized fiber structure generated using a numerical deposition procedure. A modified Monte Carlo method is introduced for the simulation of the ink dynamics. Besides, a multiphase lattice Boltzmann method is suggested to fine-tune the mesoscopic variational model parameters, and it is shown that the ink seepage behaviors predicted by the proposed model can resemble those predicted by a method relying on first principles.

Keywords: fibrous media, lattice Boltzmann, modelling and simulation, Monte Carlo, variational model

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Authors: Mohd Raish Ansari, Tauheed Alam Khan

Abstract:

This research paper is a comparative study of the belt truss in the Regular RC frame structure at the different positions of the floor. The method used in this research is the response spectrum method with the help of the ETABS Software, there are six models in this paper with belt truss. The Indian standard code used in this work are IS 456:2000, IS 800:2007, IS 875 part-1, IS 875 part-1, and IS 1893 Part-1:2016. The cross-section of the belt truss is the I-section, a grade of steel that is made up of Mild Steel. The basic model in this research paper is the same, only position of the belt truss is going to change, and the dimension of the belt truss is remain constant for all models. The plan area of all models is 24.5 meters x 28 meters, and the model has G+20, where the height of the ground floor is 3.5 meters, and all floor height is 3.0 meters remains constant. This comparative research work selected some important seismic parameters to check the stability of all models, the parameters are base shear, fundamental period, storey overturning moment, and maximum storey displacement.

Keywords: belt truss, RC frames structure, ETABS, response spectrum analysis, special moment resisting frame

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Authors: Shivi Rastogi, Suman Pant

Abstract:

Khadi is an Indian fabric and also known by another name “Khaddar”. During pre-independence era, the movement of khadi manufacturing gained momentum. Over the years, khadi fabrics that were generally considered as the “second skin” of the Swadesh revolutionists changed its uniqueness. It underwent a metamorphosis from that of a patriot’s fabric, and a farmer’s apparel, to become a “fashion fabric”. Drape of garment is governed by draping quality of fabric used. Drape is an essential parameter to decide both appearance and handle of fabric. It is also a secondary determinant of fabric mechanical properties as influenced by the low stress properties, like bending length, formability, tensile and shear properties and compressibility of the fabric. In finishing, fabric is treated to add something to coat the fabric or fiber and thereby temporarily or permanently fix. Film forming agents such as thermoplastic and thermosetting resins and other surface deposits alter hand. In this study, resins were used to modify fabric hand. Three types of resins have been applied on the khadi fabric at three concentration. The effect of these finishes on drapeability, crease recovery, stiffness, tearing strength and smoothness of khadi fabrics were assessed. Silicone gave good results in imparting properties specially drape, smoothness and softness and hand of cotton and khadi fabric. KES result also showed that silicone treated samples enhanced THV rating amongst all treated samples when compared to the control fabric.

Keywords: crease recovery, drapeability, KES, silicone, THV

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