Search results for: parental influence

Authors: Aitor Bilbao, Dragos Axinte, John Billingham

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The inverse problem in Energy Beam (EB) Processes consists of defining the control parameters, in particular the 2D beam path (position and orientation of the beam as a function of time), to arrive at a prescribed solution (freeform surface). This inverse problem is well understood for conventional machining, because the cutting tool geometry is well defined and the material removal is a time independent process. In contrast, EB machining is achieved through the local interaction of a beam of particular characteristics (e.g. energy distribution), which leads to a surface-dependent removal rate. Furthermore, EB machining is a time-dependent process in which not only the beam varies with the dwell time, but any acceleration/deceleration of the machine/beam delivery system, when performing raster paths will influence the actual geometry of the surface to be generated. Two different EB processes, Abrasive Water Machining (AWJM) and Pulsed Laser Ablation (PLA), are studied. Even though they are considered as independent different technologies, both can be described as time-dependent processes. AWJM can be considered as a continuous process and the etched material depends on the feed speed of the jet at each instant during the process. On the other hand, PLA processes are usually defined as discrete systems and the total removed material is calculated by the summation of the different pulses shot during the process. The overlapping of these shots depends on the feed speed and the frequency between two consecutive shots. However, if the feed speed is sufficiently slow compared with the frequency, then consecutive shots are close enough and the behaviour can be similar to a continuous process. Using this approximation a generic continuous model can be described for both processes. The inverse problem is usually solved for this kind of process by simply controlling dwell time in proportion to the required depth of milling at each single pixel on the surface using a linear model of the process. However, this approach does not always lead to the good solution since linear models are only valid when shallow surfaces are etched. The solution of the inverse problem is improved by using a discrete adjoint optimization algorithm. Moreover, the calculation of the Jacobian matrix consumes less computation time than finite difference approaches. The influence of the dynamics of the machine on the actual movement of the jet is also important and should be taken into account. When the parameters of the controller are not known or cannot be changed, a simple approximation is used for the choice of the slope of a step profile. Several experimental tests are performed for both technologies to show the usefulness of this approach.

Keywords: abrasive waterjet machining, energy beam processes, inverse problem, pulsed laser ablation

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Authors: Fares Alsewailem

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Material recycling of thermoplastic waste offers practical solution for municipal solid waste reduction. Post-consumer plastics such as polyethylene (PE), polyethyleneterephtalate (PET), and polystyrene (PS) may be separated from each other by physical methods such as density difference and hence processed as single plastic, however one should be cautious about the contaminants presence in the waste stream inform of paper, glue, etc. since these articles even in trace amount may deteriorate properties of the recycled plastics especially the mechanical properties. furthermore, melt processing methods used to recycle thermoplastics such as extrusion and compression molding may induce degradation of some of the recycled plastics such as PET and PS. In this research, it is shown that care should be taken when processing recycled plastics by melt processing means in two directions, first contaminants should be extremely minimized, and secondly melt processing steps should also be minimum.

Keywords: Recycling, PET, PS, HDPE, mechanical

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Authors: Anjli Pathak, Harshit Sosan Lakra, Smriti Mishra

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The increasing urbanization affects the external environment in which people exist and imposes livelihood vulnerability to shocks and stresses. Although research on the linkages between urbanization and vulnerability has been increasing, only a few studies have examined the caste/ethnicity in livelihood vulnerability. In this study, we explore how physical capital influences vulnerability among indigenous people in the context of livelihood. The study identifies the dimensions and indicators of physical capital that influence the profile of household vulnerability in the livelihood-building process. The result identified five dimensions and 19 indicators of livelihood vulnerability. The study also visualizes the inter-relationship between physical capital and other livelihood capital in formulating the livelihood vulnerability framework.

Keywords: urbanization, livelihood vulnerability, indigenous people, physical capital

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Authors: Rim Zgueb, Noureddine Yacoubi

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The work concerns thermo-mechanical properties of cement Sorel mixed with different proportions of glass powder. Five specimens were developed. Four different glass powder mixtures were developed 5%, 10%, 15% and 20% with one control sample without glass powder. The research presented in this study focused on evaluating the effects of replacing portion of glass powder with various percentages of cement Sorel. The influence of the glass powder on the thermal conductivity, thermal diffusivity, bulk density and compressive strength of the cement Sorel at 28 days of curing were determined. The thermal property of cement was measured by using Photothermal deflection technique PTD. The results revealed that the glass powder additive affected greatly on the thermal properties of the cement.

Keywords: cement sorel, photothermal deflection technique, thermal conductivity, thermal diffusivity

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Authors: K. -H. Yang

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In the past, the quay crane operations have been well studied. There were a certain number of scheduling algorithms for quay crane operations, but without considering some nuisance factors that might disrupt the quay crane operations. For example, bad grapples make a crane unable to load or unload containers or a sudden strong breeze stops operations temporarily. Although these disruptive conditions randomly occur, they influence the efficiency of quay crane operations. The disruption is not considered in the operational procedures nor is evaluated in advance for its impacts. This study applies simulation and optimization approaches to develop structures of pre-analysis and post-analysis for the Quay Crane Scheduling Problem to deal with disruptive scenarios for quay crane operation. Numerical experiments are used for demonstrations for the validity of the developed approaches.

Keywords: disruptive quay crane scheduling, pre-analysis, post-analysis, disruption

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Authors: M. Sandeep Kumar, Vasu Velagapudi, A. Venugopal

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When machining is carried out on a workpiece, residual stresses are induced in the workpiece due to nonuniform thermal and mechanical loads. These stresses play a vital role in the surface integrity of the final product or the output. Inconel 718 is commonly used in critical structural components of aircraft engines due to its properties at high temperatures. Therefore it is important to keep down the stresses induced due to machining. This can be achieved through proper lubricating conditions. In this work, experiments were carried out to check the influence of the developed nanofluid as cutting fluids on residual stresses developed during the course of machining. The results of MQL/Nanofluids were compared with MQL/Vegetable oil and dry machining lubricating condition. Results indicate the reduction in residual stress with the use of MQL/Nanofluid.

Keywords: nanofluids, MQL, residual stress, Inconel-718

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Authors: Szymon Kuczynski

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Poland is characterized by the presence of numerous sedimentary basins and hydrocarbon provinces. Since 2006 exploration for hydrocarbons in Poland become gradually more focus on new unconventional targets, particularly on the shale gas potential of the Upper Ordovician and Lower Silurian in the Baltic-Podlasie-Lublin Basin. The first forecast prepared by US Energy Information Administration in 2011 indicated to 5.3 Tcm of natural gas. In 2012, Polish Geological Institute presented its own forecast which estimated maximum reserves on 1.92 Tcm. The difference in the estimates was caused by problems with calculations of the initial amount of adsorbed, as well as free, gas trapped in shale rocks (GIIP - Gas Initially in Place). This value is dependent from sorption capacity, gas saturation and mutual interactions between gas, water, and rock. Determination of the reservoir type in the initial exploration phase brings essential knowledge, which has an impact on decisions related to the production. The study of porosity impact for phase envelope shift eliminates errors and improves production profitability. Confinement phenomenon affects flow characteristics, fluid properties, and phase equilibrium. The thermodynamic behavior of confined fluids in porous media is subject to the basic considerations for industrial applications such as hydrocarbons production. In particular the knowledge of the phase equilibrium and the critical properties of the contained fluid is essential for the design and optimization of such process. In pores with a small diameter (nanopores), the effect of the wall interaction with the fluid particles becomes significant and occurs in shale formations. Nano pore size is similar to the fluid particles’ diameter and the area of particles which flow without interaction with pore wall is almost equal to the area where this phenomenon occurs. The molecular simulation studies have shown an effect of confinement to the pseudo critical properties. Therefore, the critical parameters pressure and temperature and the flow characteristics of hydrocarbons in terms of nano-scale are under the strong influence of fluid particles with the pore wall. It can be concluded that the impact of a single pore size is crucial when it comes to the nanoscale because there is possible the above-described effect. Nano- porosity makes it difficult to predict the flow of reservoir fluid. Research are conducted to explain the mechanisms of fluid flow in the nanopores and gas extraction from porous media by desorption.

Keywords: adsorption, capillary condensation, phase envelope, nanopores, unconventional natural gas

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Authors: E. V. Fakhrutdinova, Y. S. Kolesnikova, E. A. Karasik, V. M. Zagidullina

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Poverty as the social and economic phenomenon exists in any society and represents a many-sided problem. In this sense it is universal and for many centuries serves as a research objects for scientists. Special attention to a problem of poverty in Russia is caused, first of all, by the critical growth of inequality and by scales of expansion of poverty, considerable decrease in the level and quality of life of the population, decrease in availability of education during the period of reforming. The expansion of poverty on the working members of society, youth, which has to provide reproduction of the population is alarming. As poverty is the reason of weakening of national security of the country, degradation of the population, decline in the quality of the human capital, complication of a demographic situation, strengthening of social contradictions in society, so far as the reduction of poverty, so, the increase in production. Poverty: the characteristic of an economic situation of the individual or social group at which they can't satisfy certain minimum requirements necessary for life, preservations of working capacity and reproduction. Poverty became one of the critical factors expelling people from the system of the institutional interactions reducing social space in which their relations were building breaking their social identity. Complication of the problem of poverty in modern society happened due to penetration of the related relations into many spheres of life. It is known that negative consequences of poverty display not only at the personal level of the poor person, but also at the level of interpersonal social interactions, decline in the quality and level of development of the human capital, and also at social and economic system in general. We conducted a research on the influence of education on the change of poverty level of the population. We consider education as a resource for an increase of the income and social mobility. Dependence of the income of the population on the level of education, availability of education (level of education and quality of education) on the level of income of families is found. Differentiation of quality and number of educational services for children depending on the level of the income of families is revealed. Influence of a factor of poverty on the availability of education is also studied. We consider expenses on education as the limiter of access to education. We consider education as a factor of fixation and aggravation of a property inequality. In the solution of problems of poverty the defining condition is the state regulation of social and economic development by means of creation of the effective institutional environment. The state has to develop measures for an increase of availability of various services to all categories of citizens, in particular services of health care and education, especially for poor citizens enters. The special attention regarding an increase of availability of education services has to be paid to creation of system of social elevators.

Keywords: poverty, education, human capital, quality of life

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Authors: Nesrin Köken, Esin A. Güvel, Nilgün Kızılcan

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This work presents synthesis of α,ω-dithienyl terminated poly(ethylene glycol) (PEGTh) capable for further chain extension by either chemical or electrochemical polymerization. PEGTh was characterized by FTIR and 1H-NMR. Further, copolymerization of PEGTh and pyrrole (Py) was performed by chemical oxidative polymerization using ceric (IV) salt as an oxidant (PPy-PEGTh). PEG without end group modification was used directly to prepare copolymers with Py by Ce (IV) salt (PPy-PEG). Block copolymers with mole ratio of pyrrole to PEGTh (PEG) 50:1 and 10:1 were synthesized. The electrical conductivities of copolymers PPy-PEGTh and PPy-PEG were determined by four-point probe technique. Influence of the synthetic route and content of the insulating segment on conductivity and yield of the copolymers were investigated.

Keywords: chemical oxidative polymerization, conducting polymer, poly(ethylene glycol), polypyrrole

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Authors: Naufal Ahmad Rijalul Alam

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This article presents a quality of education for the poor people in Indonesia and the offering of strategy to be done. It also investigates the influence of Islamic Education which stands behind the religious values in developing effort of government to respond the problem with using humanities approaches in medium society. The offering strategy resulted in four agenda: 1) building a shared commitment, 2) encouraging the improvement of the quality of public and private schools, 3) encouraging the use of 'the indicator of disaffection' for gifted children, and 4) encouraging the enlargement of vocational training centers and polytechnics. The conclusion is that the quality of education can be increased with these four agenda, although they are not too easy because it deals with other factors such as the economy, politics, and culture which is happening in the country.

Keywords: quality education, poor people, strategy of Islamic education, medium community

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Authors: Tadele Tesfaw, Ajit Pal Singh, Abebaw Mekonnen Gezahegn

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Welding is a basic manufacturing process for making components or assemblies. Recent welding economics research has focused on developing the reliable machinery database to ensure optimum production. Research on welding of materials like steel is still critical and ongoing. Welding input parameters play a very significant role in determining the quality of a weld joint. The metal active gas (MAG) welding parameters are the most important factors affecting the quality, productivity and cost of welding in many industrial operations. The aim of this study is to investigate the optimization process parameters for metal active gas welding for 60x60x5mm dead mild steel plate work-piece using Taguchi method to formulate the statistical experimental design using semi-automatic welding machine. An experimental study was conducted at Bishoftu Automotive Industry, Bishoftu, Ethiopia. This study presents the influence of four welding parameters (control factors) like welding voltage (volt), welding current (ampere), wire speed (m/min.), and gas (CO2) flow rate (lit./min.) with three different levels for variability in the welding hardness. The objective functions have been chosen in relation to parameters of MAG welding i.e., welding hardness in final products. Nine experimental runs based on an L9 orthogonal array Taguchi method were performed. An orthogonal array, signal-to-noise (S/N) ratio and analysis of variance (ANOVA) are employed to investigate the welding characteristics of dead mild steel plate and used in order to obtain optimum levels for every input parameter at 95% confidence level. The optimal parameters setting was found is welding voltage at 22 volts, welding current at 125 ampere, wire speed at 2.15 m/min and gas flow rate at 19 l/min by using the Taguchi experimental design method within the constraints of the production process. Finally, six conformations welding have been carried out to compare the existing values; the predicated values with the experimental values confirm its effectiveness in the analysis of welding hardness (quality) in final products. It is found that welding current has a major influence on the quality of welded joints. Experimental result for optimum setting gave a better hardness of welding condition than initial setting. This study is valuable for different material and thickness variation of welding plate for Ethiopian industries.

Keywords: Weld quality, metal active gas welding, dead mild steel plate, orthogonal array, analysis of variance, Taguchi method

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Authors: Khishig-Undrakh Mijgee, Yerkyejan Amanbyek, Yilina, Bayarkhuu Agvaanbayar, Anudari Chingiskhuu

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The study of happiness focuses on how people perceive their well-being, the ways they seek happiness, and the factors that affect their feelings of happiness, including self-esteem, depression, satisfaction, and the quality of life. Researchers also aim to explore the relationship between happiness, self-esteem, depression, satisfaction, and quality of life, with the goal of assessing people's sense of achievement. Happiness is strongly linked to an individual's sense of achievement and overall life satisfaction. In this article, we will discuss the findings of a study that examines the feelings of happiness and the factors that influence them among 562 high school students.

Keywords: happiness, high school students, feelings of happiness, happiness level

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Authors: Eva Kotlánová

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After recession that began in 2007 in the United States and subsequently spilled over the Europe we could expect recovery of economic growth. According to the last estimation of economic progress of European countries, this recovery is not strong enough. Among others, it will depend on economic policy, where and in which way, the economic indicators will proceed. Economic theories postulate that the economic subjects prefer stably, continual economic policy without repeated and strong fluctuations. This policy is perceived as support of economic growth. Mostly in crises period, when the government must cope with consequences of recession, the economic policy becomes unpredictable for many subjects and economic policy uncertainty grows, which have negative influence on economic growth. The aim of this paper is to use panel regression to prove or disprove this hypothesis on the example of five largest European economies in the period 2008–2012.

Keywords: economic crises in Europe, economic policy, uncertainty, panel analysis regression

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Authors: Muhaimin Bin Sulam, Abdul Mutalib Embong, Azelin Mohamed Noor

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This paper presents the reinvention of the role of education (tarbiyyah) in the social influence of organizations focusing on the sustainability of a specific religio-political organization. The objective of the paper is to describe how the position secured by education could transform the organization while maintaining its objective and vision. The study employed the qualitative approach that involves data from conducted interviews. An analysis on the role political leaders play in educating the organization in the context of ideological struggle is also analyzed. The process description also evaluates how education could intellectualize its followers and members which inspires them to submit to their leaders and the organization. This extensive cultivation of religio-political doctrine could offer a new interpretation on politics.

Keywords: religiopolitical organization, Malaysia, education (Tarbiyyah), followers, political movement

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Authors: Reham Alwazzan

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Ibn Sina (d. 1037) is perhaps the most important philosopher of the pre-modern era. Among his many contributions, the proof for the existence of the necessary existent stands out. Ibn Sina proceeds to extract each of God’s attributes (sifat) from His necessary existence. Although his ideas met with resistance in some quarters, they found a warm reception in the Akbarian school, particularly in the works of Sadr al-Din al-Qunawi (d. 1274) and ‘Abd al-Razzaq al-Qashani (d. 1335). This paper argues that the influence of Ibn Sina’s concept of necessity (wujub) had a great impact on the founder of the Akbarian school, Muhyi al-Din ibn ‘Arabi (d. 1240). Ibn ‘Arabi reformulates God’s necessary existence (wujud) as God’s necessary/metaphysical mercy (rahma) in order to extract all of the divine names from this primary attribute of God. Even as he denies all influences and insists his work is the product of spiritual unveiling (kashf), Ibn ‘Arabi seems to be following the same path delineated by his illustrious predecessor, if in his own way.

Keywords: existence, Ibn ‘Arabi, Ibn Sina, mercy, necessity

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Authors: B. S. Jayashankarbabu, Karisiddappa

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The finite element method is used to obtain the elastic buckling load factor for square isotropic plate containing circular, square and rectangular cutouts. ANSYS commercial finite element software had been used in the study. The applied inplane loads considered are uniaxial and biaxial compressions. In all the cases the load is distributed uniformly along the plate outer edges. The effects of the size and shape of concentric cutouts with different plate thickness ratios and the influence of plate edge condition, such as SSSS, CCCC and mixed boundary condition SCSC on the plate buckling strength have been considered in the analysis.

Keywords: concentric cutout, elastic buckling, finite element method, inplane loads, thickness ratio

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Authors: Miroslav H. Hristov, Velizar A. Vassilev, Georgi K. Dukendjiev

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Due to the constant development of measurement systems and the aim for computerization, unavoidable improvements are made for the main disadvantages of air gauges. With the appearance of the air-electronic measuring devices, some of their disadvantages are solved. The output electrical signal allows them to be included in the modern systems for measuring information processing and process management. Producer efforts are aimed at reducing the influence of supply pressure and measurement system setup errors. Increased accuracy requirements and preventive error measures are due to the main uses of air electronic systems - measurement of geometric dimensions in the automotive industry where they are applied as modules in measuring systems to measure geometric parameters, form, orientation and location of the elements.

Keywords: air-electronic, geometrical parameters, improvement, measurement systems

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Authors: S. M. Hashemy Shahdany

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Equitable water delivery becomes one of the main concerns for water authorities in arid regions. Due to water scarcity, providing reliable amount of water is not possible for most of the irrigation districts in arid regions. In this paper, water level difference control is applied to keep the water level errors equal in adjacent reaches. Distant downstream decentralized configurations of the control method are designed and tested under a realistic scenario shows canal operation under water shortage. The simulation results show that the difference controllers share the water level error among all of the users in a fair way. Therefore, water deficit has a similar influence on downstream as well as upstream and water offtakes.

Keywords: equitable water distribution, precise agriculture, sustainable agriculture, water shortage

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Authors: Maria Vueba, Tchilissila A. Simoes

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Angola has a deficient health system characterized by reduced human and material resources. Nurses are the main actors combating different types of diseases simultaneously dealing with a lack of essentials tools and means. In this study, we aimed to assess the organizational commitment and job satisfaction of 51 health professionals from a maternity ward in Lubango, Angola. Participants completed the Organizational Commitment Questionnaire and the Job Satisfaction Scale and demonstrated a strong commitment towards the maternal facility, despite the majority of them were not satisfied with their work. Moreover, the gender and years of service seemed to not influence the level of commitment and satisfaction among the professionals. These results show the need for organizational restructuration (i.e., wages, career progression, supervision) to increase job satisfaction in this institution.

Keywords: Africa, health professionals, organizational commitment, work satisfaction

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Authors: Rahmat Ali, Beenish Khan, Aftabullah, Abid A. Shah

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This research is an attempt to investigate the wide range of events using acoustic emission (AE) sensors of the concrete cubes subjected to different stress condition loading and unloading of concrete cubes. A total of 27 specimens were prepared and tested including 18 cubic (6”x6”x6”) and nine cylindrical (4”x8”) specimens were molded from three batches of concrete using w/c of 0.40, 0.50, and 0.60. The compressive strength of concrete was determined from concrete cylinder specimens. The deterioration of concrete was evaluated using the occurrence of felicity and Kaiser effects at each stress condition. It was found that acoustic emission hits usually exceeded when damage increases. Additionally, the correlation between AE techniques and the load applied were determined by plotting the normalized values. The influence of w/c on sensitivity of the AE technique in detecting concrete damages was also investigated.

Keywords: acoustic emission, concrete, felicity ratio, sensors

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Authors: Mohammad Javad Mollakazemi, Farhad Asadi

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In this paper a real-time obstacle avoidance approach for both autonomous and non-autonomous dynamical systems (DS) is presented. In this approach the original dynamics of the controller which allow us to determine safety margin can be modulated. Different common types of DS increase the robot’s reactiveness in the face of uncertainty in the localization of the obstacle especially when robot moves very fast in changeable complex environments. The method is validated by simulation and influence of different autonomous and non-autonomous DS such as important characteristics of limit cycles and unstable DS. Furthermore, the position of different obstacles in complex environment is explained. Finally, the verification of avoidance trajectories is described through different parameters such as safety factor.

Keywords: limit cycles, nonlinear dynamical system, real time obstacle avoidance, safety margin

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Authors: A. Ja, J. Belabid, A. Cheddadi

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This paper reports the numerical simulation of double diffusive natural convection flows within a horizontal annular filled with a saturated porous medium. The analysis concerns the influence of the different parameters governing the problem, namely, the Rayleigh number Ra, the Lewis number Le and the buoyancy ratio N, on the heat and mass transfer and on the flow structure, in the case of a fixed radius ratio R = 2. The numerical model used for the discretization of the dimensionless equations governing the problem is based on the finite difference method, using the ADI scheme. The study is focused on steady-state solutions in the cooperation situation.

Keywords: natural convection, double-diffusion, porous medium, annular geometry, finite differences

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Authors: Harun Çoban, Aydın Akın

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In this study, the effects of different dose zinc application from soil and foliar on drying yield and some quality characters of raisins ‘Sultana’ were investigated. The experiment was conducted in randomized blocks with four replications, zinc treatment was used at one time (before pre- bloom) and from foliar in three times (pre-bloom, fruit set, and veraison). At harvest, both soil and foliar zinc sulphate applications increased the amount of fresh grapes per vine. Fresh grapes were dried on the drying place. However, the most efficient applications for drying yield and quality of raisins were observed from foliar. Therefore, it was preferred that foliar application dosage level at 0.10 %.

Keywords: zinc, raisins, soil application, foliar application, sultana, expertise value

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Authors: Hadj Miloua, Abbes Azzi

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The objective of the present paper is to understand, predict and modeled the fire behavior in confined and open area in different conditions and diverse fuels such as liquid pool fire and the vegetative materials. The distinctive problems are a ventilated road tunnel used for urban transport, by the characterization installations of ventilation and his influence in the mode of smoke dispersion and the flame shape. A general investigation is relatively traditional, based on the modeling and simulation the scenario of the pool fire interacted with wind ventilation by the use of numerical software fire dynamic simulator FDS ver.5 to simulate the fire in ventilated tunnel. The second simulation by WFDS.5 is Wildland fire which is always occurs in forest and rangeland fire environments and will thus have an impact on people, property and resources.

Keywords: fire, road tunnel, simulation, vegetation, wildland

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Authors: Ram Mohan, Mahendran Samykano, Shyam Aravamudhan

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Metallic nanowires with sub-micron and hundreds of nanometer diameter have a diversity of applications in nano/micro-electromechanical systems (NEMS/MEMS). Characterizing the mechanical properties of such sub-micron and nano-scale metallic nanowires are tedious; require sophisticated and careful experimentation to be performed within high-powered microscopy systems (scanning electron microscope (SEM), atomic force microscope (AFM)). Also, needed are nanoscale devices for placing the nanowires; loading them with the intended conditions; obtaining the data for load–deflection during the deformation within the high-powered microscopy environment poses significant challenges. Even picking the grown nanowires and placing them correctly within a nanoscale loading device is not an easy task. Mechanical characterizations through experimental methods for such nanowires are still very limited. Various techniques at different levels of fidelity, resolution, and induced errors have been attempted by material science and nanomaterial researchers. The methods for determining the load, deflection within the nanoscale devices also pose a significant problem. The state of the art is thus still at its infancy. All these factors result and is seen in the wide differences in the characterization curves and the reported properties in the current literature. In this paper, we discuss and present our experimental method, results, and discussions of uniaxial tensile loading and the development of subsequent stress–strain characteristics curves for Nickel nanowires. Nickel nanowires in the diameter range of 220–270 nm were obtained in our laboratory via an electrodeposition method, which is a solution based, template method followed in our present work for growing 1-D Nickel nanowires. Process variables such as the presence of magnetic field, its intensity; and varying electrical current density during the electrodeposition process were found to influence the morphological and physical characteristics including crystal orientation, size of the grown nanowires1. To further understand the correlation and influence of electrodeposition process variables, associated formed structural features of our grown Nickel nanowires to their mechanical properties, careful experiments within scanning electron microscope (SEM) were conducted. Details of the uniaxial tensile characterization, testing methodology, nanoscale testing device, load–deflection characteristics, microscopy images of failure progression, and the subsequent stress–strain curves are discussed and presented.

Keywords: uniaxial tensile characterization, nanowires, electrodeposition, stress-strain, nickel

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Authors: Maryamosadat Ghasemi, Reza Amrollahi

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Plasma equilibrium geometry has a great influence on the confinement and magnetohydrodynamic stability in tokamaks. The poloidal field (PF) system of a tokamak should be able to support this plasma equilibrium geometry. In this work the prepared numerical code based on radial basis functions are presented and used to solve the Grad–Shafranov (GS) equation for the axisymmetric equilibrium of tokamak plasma. The radial basis functions (RBFs) which is a kind of numerical meshfree method (MFM) for solving partial differential equations (PDEs) has appeared in the last decade and is developing significantly in the last few years. This technique is applied in this study to obtain the equilibrium configuration for Alborz Tokamak. The behavior of numerical solution convergences show the validation of this calculations.

Keywords: equilibrium, grad–shafranov, radial basis functions, Alborz Tokamak

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Authors: Belen Montero, Carmen Ramirez, Maite Rico, Rebeca Bouza, Irene Derungs

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Starch is a promising polymer for producing biocomposite materials because it is renewable, completely biodegradable and easily available at a low cost. Thermoplastic starches (TPS) can be obtained after the disruption and plasticization of native starch with a plasticizer. In this work, the solvent casting method was used to obtain TPS films from wheat starch plasticized with glycerol and reinforced with nanocellulose (CNC). X-ray diffraction analysis was used to follow the evolution of the crystallinity. The native wheat starch granules have shown a profile corresponding to A-type crystal structures typical for cereal starches. When TPS films are analyzed a high amorphous halo centered on 19º is obtained, indicating the plasticization process is completed. SEM imaging was made in order to analyse the morphology. The image from the raw wheat starch granules shows a bimodal granule size distribution with some granules in large round disk-shape forms (A-type) and the others as smaller spherical particles (B-type). The image from the neat TPS surface shows a continuous surface. No starch aggregates or swollen granules can be seen so, the plasticization process is complete. In the surfaces of reinforced TPS films aggregates are seen as the CNC concentration in the matrix increases. The CNC influence on the mechanical properties of TPS films has been studied by dynamic mechanical analysis. A direct relation exists between the storage modulus values, E’, and the CNC content in reinforced TPS films: higher is the content of nanocellulose in the composite, higher is the value of E’. This reinforcement effect can be explained by the appearance of a strong and crystalline nanoparticle-TPS interphase. Thermal stability of films was analysed by TGA. It has not observed any influence on the behaviour related to the thermal degradation of films with the incorporation of the CNC. Finally, the resistance to the water absorption films was analysed following the standard UNE-EN ISO 1998:483. The percentage of water absorbed by the samples at each time was calculated. The addition of 5 wt % of CNC to the TPS matrix leads to a significant improvement in the moisture resistance of the starch based material decreasing their diffusivity. It has been associated to the formation of a nanocrystal network that prevents swelling of the starch and therefore water absorption and to the high crystallinity of cellulose compared to starch. As a conclusion, the wheat film reinforced with 5 wt % of cellulose nanocrystals seems to be a good alternative for short-life applications into the packaging industry, because of its greatest rigidity, thermal stability and moisture sorption resistance.

Keywords: biocomposites, nanocellulose, starch, wheat

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Authors: Pamela Del Rosario, Elisabetta Palumbo, Marzia Traverso

Abstract:

The building sector plays an important role in addressing pressing environmental issues such as climate change and resource scarcity. The energy performance of buildings is considerably affected by the external envelope. In fact, a considerable proportion of the building energy demand is due to energy losses through the windows. Nevertheless, according to literature, to pay attention only to the contribution of windows to the building energy performance, i.e., their influence on energy use during building operation, could result in a partial evaluation. Hence, it is important to consider not only the building energy performance but also the environmental performance of windows, and this not only during the operational stage but along its complete life cycle. Life Cycle Assessment (LCA) according to ISO 14040:2006 and ISO 14044:2006+A1:2018 is one of the most adopted and robust methods to evaluate the environmental performance of products throughout their complete life cycle. This life-cycle based approach avoids the shift of environmental impacts of a life cycle stage to another, allowing to allocate them to the stage in which they originated and to adopt measures that optimize the environmental performance of the product. Moreover, the LCA method is widely implemented in the construction sector to assess whole buildings as well as construction products and materials. LCA is regulated by the European Standards EN 15978:2011, at the building level, and EN 15804:2012+A2:2019, at the level of construction products and materials. In this work, the environmental performance of wooden windows was assessed by implementing the LCA method and adopting primary data. More specifically, the emphasis is given to embedded and operational impacts. Furthermore, correlations are made between these environmental impacts and aspects such as type of wood and window transmittance. In the particular case of the operational impacts, special attention is set on the definition of suitable maintenance scenarios that consider the potential climate influence on the environmental impacts. For this purpose, a literature review was conducted, and expert consultation was carried out. The study underlined the variability of the embedded environmental impacts of wooden windows by considering different wood types and transmittance values. The results also highlighted the need to define appropriate maintenance scenarios for precise assessment results. It was found that both the service life and the window maintenance requirements in terms of treatment and its frequency are highly dependent not only on the wood type and its treatment during the manufacturing process but also on the weather conditions of the place where the window is installed. In particular, it became evident that maintenance-related environmental impacts were the highest for climate regions with the lowest temperatures and the greatest amount of precipitation.

Keywords: embedded impacts, environmental performance, life cycle assessment, LCA, maintenance stage, operational impacts, wooden windows

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Authors: Seyedehzahra Mirrahimi

Abstract:

This paper investigates the effect of variations in window and ceiling heights on cooling inside an architectural training studio with a full-width window. For architectural training, students use the studio more often than they use ordinary classrooms. Therefore, studio dimensions and size, and the window position, directly influence the cooling load. Energy for cooling is one of the most expensive costs in the studio because of the high activity levels of students during the warm season. The methodology of analysis involves measuring energy changes in the Energy Plus software in Kish Island. It was proved that the cooling energy in an architecture studio can be increased by changing window levels and ceiling heights to add a range of cooling energy.

Keywords: cooling energy, Energy Plus, studio classroom, window position

Procedia PDF Downloads 277

Authors: Septiany Trisnaningtyas

Abstract:

Purpose: This research aims to examine the factors affecting the profitability of pharmaceutical company during the Covid-19 Pandemic in Indonesia. A sharp decline in the number of patients coming to the hospital for treatment during the pandemic has an impact on the growth of the pharmaceutical sector and brought major changes in financial position and business performance. Pharmaceutical companies that provide products related to the Covid-19 pandemic can survive and continue to grow. This study investigates the factors affecting the profitability of pharmaceutical company during the Covid-19 Pandemic in Indonesia associated with the number of Covid-19 cases. Design/methodology/approach: This study uses panel-data regression models to evaluate the influence of the number of Covid-19 confirmed cases on profitability of ninelisted pharmaceuticalcompanies in Indonesia. This research is based on four independent variables that were empirically examined for their relationship with profitability. These variables are liquidity (current ratio), growth rate (sales growth), firm size (total sales), and market power (the Lerner index). Covid-19 case is used as moderating variable. Data of nine pharmaceutical companies listed on the Indonesia Stock Exchange covering the period of 2018–2021 were extracted from companies’ quarterly annual reports. Findings: In the period during Covid-19, company growth (sales growth) and market power (lerner index) have a positive and significant relationship to ROA and ROE. Total of confirmed Covid-19 cases has a positive and significant relationship to ROA and is proven to have a moderating effect between company’s growth (sales growth) to ROA and ROE and market power (Lerner index) to ROA. Research limitations/implications: Due to data availability, this study only includes data from nine listed pharmaceutical companies in Indonesian Stock exchange and quarterly annual reportscovering the period of 2018-2021. Originality/value: This study focuses onpharmaceutical companies in Indonesia during Covid-19 pandemic. Previous study analyzes the data from pharmaceutical companies’ annual reports since 2014 and focus on universal health coverage (national health insurance) implementation from the Indonesian government. This study analyzes the data using fixed effect panel-data regression models to evaluate the influence of Covid-19 confirmed cases on profitability. Pooled ordinary least squares regression and fixed effects were used to analyze the data in previous study. This study also investigate the moderating effect of Covid-19 confirmed cases to profitability in relevant with the pandemic situation.

Keywords: profitability, indonesia, pharmaceutical, Covid-19

Procedia PDF Downloads 104