Search results for: convergence process

Authors: Somaye Eskandary

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Polycyclic aromatic hydrocarbons (PAHs) are present in crude oil and its derivatives contaminate soil and also increase carcinogen and mutagen contamination, which is a concern for researchers. Land farming is one of the methods that remove pollutants from the soil by native microorganisms. It seems that this technology is cost-effective, environmentally friendly and causes less debris problem to be disposed. This study aimed to refine the polycyclic aromatic hydrocarbons from oil-contaminated soil using the land farming method. In addition to examine the concentration of polycyclic aromatic hydrocarbons by GC-FID, some characteristics such as soil microbial respiration and dehydrogenase, peroxidase, urease, acid and alkaline phosphatase enzyme concentration were also measured. The results showed that after land farming process the concentrations of some polycyclic aromatic hydrocarbons dropped to 50 percent. The results showed that the enzyme concentration is reduced by reducing the concentration of hydrocarbons and microbial respiration. These results emphasize the process of land farming for removal of polycyclic aromatic hydrocarbons from soil by indigenous microorganisms.

Keywords: soil contamination, gas chromatography, native microorganisms, soil enzymes, microbial respiration, carcinogen

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Authors: Mahdi Fakoor, Seyed Mohammad Navid Ghoreishi

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Composite patching is a common way for reinforcing the cracked pipes and cylinders. The effects of composite patch reinforcement on fracture parameters of a cracked pipe depend on a variety of parameters such as number of layers, angle, thickness, and material of each layer. Therefore, stacking sequence optimization of composite patch becomes crucial for the applications of cracked pipes. In this study, in order to obtain the optimal stacking sequence for a composite patch that has minimum weight and maximum resistance in propagation of cracks, a coupled Multi-Objective Genetic Algorithm (MOGA) and Finite Element Method (FEM) process is proposed. This optimization process has done for longitudinal and transverse semi-elliptical cracks and optimal stacking sequences and Pareto’s front for each kind of cracks are presented. The proposed algorithm is validated against collected results from the existing literature.

Keywords: multi objective optimization, pareto front, composite patch, cracked pipe

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Authors: Barry Majeed, Eka Febriana, Seto Julianto

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Kepulauan Seribu National Parks is a marine preservation region in Indonesia. It is located in 5°23' - 5°40' LS, 106°25' - 106°37' BT North of Jakarta City. Covered with area 107,489 ha, Kepulauan Seribu has a lot of tourism spots such as cluster islands, fringing reef and many more. Kepulauan Seribu is also nominated as Strategic Tourism Region In Indonesia (KSPN). So, these islands have a lot of potential sides more than preservation function as a national park, hence the development of sustainable geotourism. The aim of this study is for enhancing the development of eco-geotourism in Kepulauan Seribu. This study concern for three main aspect of eco-geotourism such as tourism, form and process. Study for the tourism aspect includes attractions, accommodations, tours, activities, interpretation, and planning & management in Kepulauan Seribu. Study for the form aspect focused on the carbonate platform situated between two islands. Primarily in carbonate reef such as head coral, branchy coral, platy coral that created the carbonate sequence in Kepulauan Seribu. Study for the process aspect primarily discussed the process of forming of carbonate from carbonate factory later becomes Kepulauan Seribu. Study for the regional geology of Kepulauan Seribu has been conducted and suggested that Kepulauan Seribu lithologies are mainly quarternary limestone. In this study, primary data was taken from an observation of quarternary carbonate platform between two islands from Hati Island, Macan Island, Bulat Island, Ubi Island and Kelapa Island. From this observation, the best routes for tourist have been made from Island to Island. Qualitative methods such as depth interview to the local people in purposive sampling also have been made. Finally, this study also giving education about geological site – carbonate sequence - in Kepulauan Seribu for the local wisdom so that this study can support the development of sustainable eco-geotourism in Kepulauan Seribu.

Keywords: carbonate factory, carbonate platform, geotourism, Kepulauan Seribu

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Authors: Hassan Zare, Mohammad Jahedi, Mohammad Reza Toroghinejad, Mahmoud Meratian, Marko Knezevic

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In this study, the carbon nanotube (CNT) reinforced Al matrix nanocomposites were fabricated by ECAP. Equal Channel Angular Pressing (ECAP) process is one of the most important methods for powder densification due to the presence of shear strain. This method samples with variety passes (one, two, four and eight passes) in C route were prepared at room temperature. A few study about metal matrix nanocomposite reinforced carbon nanotube done, the reaction intersection of interface and carbon nanotube cause to reduce the efficiency of nanocomposite. In this paper, we checked mechanical and physical properties of aluminum-CNT composite that manufactured by ECAP when the composite is deformed. The non-agglomerated CNTs were distributed homogeneously with 2% consolidation in the Aluminum matrix. The ECAP process was performed on the both monolithic and composite with distributed CNT samples for 8 passes.

Keywords: powder metallurgy, ball mill attrition, ultrasonic, consolidation

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Authors: Cagri Mollamahmutoglu, Aykut Levent, Ali Mercan

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Micro-beams are one of the most common components of Nano-Electromechanical Systems (NEMS) and Micro Electromechanical Systems (MEMS). For this reason, static bending, buckling, and free vibration analysis of micro-beams have been the subject of many studies. In addition, micro-beams restrained with elastic type foundations have been of particular interest. In the analysis of microstructures, closed-form solutions are proposed when available, but most of the time solutions are based on numerical methods due to the complex nature of the resulting differential equations. Thus, a robust and efficient solution method has great importance. In this study, a mixed finite element formulation is obtained for a functionally graded Timoshenko micro-beam resting on two-parameter elastic foundation. In the formulation modified couple stress theory is utilized for the micro-scale effects. The equation of motion and boundary conditions are derived according to Hamilton’s principle. A functional, derived through a scientific procedure based on Gateaux Differential, is proposed for the bending and buckling analysis which is equivalent to the governing equations and boundary conditions. Most important advantage of the formulation is that the mixed finite element formulation allows usage of C₀ type continuous shape functions. Thus shear-locking is avoided in a built-in manner. Also, element matrices are sparsely populated and can be easily calculated with closed-form integration. In this framework results concerning the effects of micro-scale length parameter, power-law parameter, aspect ratio and coefficients of partially or fully continuous elastic foundation over the static bending, buckling, and free vibration response of FG-micro-beam under various boundary conditions are presented and compared with existing literature. Performance characteristics of the presented formulation were evaluated concerning other numerical methods such as generalized differential quadrature method (GDQM). It is found that with less computational burden similar convergence characteristics were obtained. Moreover, formulation also includes a direct calculation of the micro-scale related contributions to the structural response as well.

Keywords: micro-beam, functionally graded materials, two-paramater elastic foundation, mixed finite element method

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Authors: Dmytro Symak

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Drying is a complex technologic, thermal and energy process. Energy cost of drying processes in many cases is the most costly stage of production, and can be over 50% of total costs. As we know, in Ukraine over 85% of Portland cement is produced moist, and the finished product energy costs make up to almost 60%. During the wet cement production, energy costs make up over 5500 kJ / kg of clinker, while during the dry only 3100 kJ / kg, that is, switching to a dry Portland cement will allow result into double cutting energy costs. Therefore, to study raw materials drying process in the manufacture of Portland cement is very actual task. The fine ferrous materials drying (small pyrites, red mud, clay Kyoko) is recommended to do by filtration method, that is one of the most intense. The essence of filtration method drying lies in heat agent filtering through a stationary layer of wet material, which is located on the perforated partition, in the "layer-dispersed material - perforated partition." For the optimum drying purposes, it is necessary to establish the dependence of pressure loss in the layer of dispersed material, and the values of heat and mass transfer, depending on the speed of the gas flow filtering. In our research, the experimentally determined pressure loss in the layer of dispersed material was generalized based on dimensionless complexes in the form and coefficients of heat exchange. We also determined the relation between the coefficients of mass and heat transfer. As a result of theoretic and experimental investigations, it was possible to develop a methodology for calculating the optimal parameters for the thermal agent and the main parameters for the filtration drying installation. The comparison of calculated by known operating expenses methods for the process of small pyrites drying in a rotating drum and filtration method shows to save up to 618 kWh per 1,000 kg of dry material and 700 kWh during filtration drying clay.

Keywords: drying, cement, heat and mass transfer, filtration method

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Authors: Martha Lilia Del Rio Duque, Michelle Bonatti, Katharina Loehr, Marcos Lana, Tatiana Rodriguez, Stefan Sieber

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Nowadays, most agricultural practices can reduce the ability of ecosystems to provide goods and services. To enhance environmentally friendly food production and to maximize social and economic benefits, sustainable land use systems (SLUS) are one of the most critical strategies increasingly/strongly promoted by donors organizations, international agencies, and policymakers. This process involves the question of how SLUS can be scaled out also large-scale landscapes and not merely isolated experiments. As SLUS are context-specific strategies, diffusion and replication of successful SLUS in Colombia required the identification of main factors that facilitate this scaling out process. We applied a case study approach to investigate the scaling out process of SLUS in cocoa and livestock sector within peacebuilding territories in Colombia, specifically, in Cesar and Caqueta region. These two regions are contrasting, but both have a current trend of increasing land degradation. Presently in Colombia, Caqueta is one of the most deforested departments, and Cesar has some most degraded soils. Following a qualitative research approach, 19 semi-structured interviews and 2 focus groups were conducted with agroforestry experts in both regions to analyze (1) what does it mean a sustainable land use system in Cocoa/Livestock, specifically in Caqueta or Cesar and (2) to identify the key elements at the level of the following dimensions: biophysical, economic and profitability, market, social, policy and institutions that can explain how and why SLUS are replicated and spread among more producers. The Interviews were coded and analyzed using MAXQDA to identify, analyze and report patterns (themes) within data. As the results show, key themes, among which: premium market, solid regional markets and price stability, water availability and management, generational renewal, land use knowledge and diversification, producer organization and certifications are crucial to understand how the SLUS can have an impact across large-scale landscapes and how the scaling out process can be set up best in order to be successful across different contexts. The analysis further reveals which key factors might affect SLUS efficiency.

Keywords: agroforestry, cocoa sector, Colombia, livestock sector, sustainable land use system

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Authors: Lamzira Ebralidze, Aleksandre Tsertsvadze, Dali Berashvili, Aliosha Bakuridze

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Nowadays, there is an increasing demand for biologically active substances from vegetable, animal, and mineral resources. In terms of the use of natural compounds, pharmaceutical, cosmetic, and nutrition industry has big interest. The biggest drawback of conventional extraction methods is the need to use a large volume of organic extragents. The removal of the organic solvent is a multi-stage process. And their absolute removal cannot be achieved, and they still appear in the final product as impurities. A large amount of waste containing organic solvent damages not only human health but also has the harmful effects of the environment. Accordingly, researchers are focused on improving the extraction methods, which aims to minimize the use of organic solvents and energy sources, using alternate solvents and renewable raw materials. In this context, green extraction principles were formed. Green Extraction is a need of today’s environment. Green Extraction is the concept, and it totally corresponds to the challenges of the 21st century. The extraction of biologically active compounds based on green extraction principles is vital from the view of preservation and maintaining biodiversity. Novel technologies of green extraction are known, such as "cold methods" because during the extraction process, the temperature is relatively lower, and it doesn’t have a negative impact on the stability of plant compounds. Novel technologies provide great opportunities to reduce or replace the use of organic toxic solvents, the efficiency of the process, enhance excretion yield, and improve the quality of the final product. The objective of the research is the development of green technologies of flavonoids containing preparations. Methodology: At the first stage of the research, flavonoids containing preparations (Tincture Herba Leonuri, flamine, rutine) were prepared based on conventional extraction methods: maceration, bismaceration, percolation, repercolation. At the same time, the same preparations were prepared based on green technologies, microwave-assisted, UV extraction methods. Product quality characteristics were evaluated by pharmacopeia methods. At the next stage of the research technological - economic characteristics and cost efficiency of products prepared based on conventional and novel technologies were determined. For the extraction of flavonoids, water is used as extragent. Surface-active substances are used as co-solvent in order to reduce surface tension, which significantly increases the solubility of polyphenols in water. Different concentrations of water-glycerol mixture, cyclodextrin, ionic solvent were used for the extraction process. In vitro antioxidant activity will be studied by the spectrophotometric method, using DPPH (2,2-diphenyl-1- picrylhydrazyl) as an antioxidant assay. The advantage of green extraction methods is also the possibility of obtaining higher yield in case of low temperature, limitation extraction process of undesirable compounds. That is especially important for the extraction of thermosensitive compounds and maintaining their stability.

Keywords: extraction, green technologies, natural resources, flavonoids

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Authors: Surinder Pal, Ajay Gupta, Johny Khajuria

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Casting simulation helps visualize mold filling and casting solidification; predict related defects like cold shut, shrinkage porosity and hard spots; and optimize the casting design to achieve the desired quality with high yield. Flow and solidification of molten metals are, however, a very complex phenomenon that is difficult to simulate correctly by conventional computational techniques, especially when the part geometry is intricate and the required inputs (like thermo-physical properties and heat transfer coefficients) are not available. Simulation software is based on the process of modeling a real phenomenon with a set of mathematical formulas. It is, essentially, a program that allows the user to observe an operation through simulation without actually performing that operation. Simulation software is used widely to design equipment so that the final product will be as close to design specs as possible without expensive in process modification. Simulation software with real-time response is often used in gaming, but it also has important industrial applications. When the penalty for improper operation is costly, such as airplane pilots, nuclear power plant operators, or chemical plant operators, a mockup of the actual control panel is connected to a real-time simulation of the physical response, giving valuable training experience without fear of a disastrous outcome. The all casting simulation software has own requirements, like magma cast has only best for crack simulation. The latest generation software Auto CAST developed at IIT Bombay provides a host of functions to support method engineers, including part thickness visualization, core design, multi-cavity mold design with common gating and feeding, application of various feed aids (feeder sleeves, chills, padding, etc.), simulation of mold filling and casting solidification, automatic optimization of feeders and gating driven by the desired quality level, and what-if cost analysis. IIT Bombay has developed a set of applications for the foundry industry to improve casting yield and quality. Casting simulation is a fast and efficient solution for process for advanced tool which is the result of more than 20 years of collaboration with major industrial partners and academic institutions around the world. In this paper the process of casting simulation is studied.

Keywords: casting simulation software’s, simulation technique’s, casting simulation, processes

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Authors: A. Saravanan, B. R. Huang, C. J. Yeh, K. C. Leou, I. N. Lin

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A new class of ultra-nano diamond-graphite nano-hybrid (DGH) composite materials containing nano-sized diamond needles was developed at low temperature process. Such kind of diamond- graphite nano-hybrid composite nanowires exhibit high electrical conductivity and excellent electron field emission (EFE) properties. Few earlier reports mention that addition of N2 gas to the growth plasma requires high growth temperature (800°C) to trigger the dopants to generate the conductivity in the films. High growth temperature is not familiar with the Si-based device fabrications. We have used a novel process such as bias-enhanced-grown (beg) MPECVD process to grow diamond films at low substrate temperature (450°C). We observed that the beg-N/UNCD films thus obtained possess high conductivity of σ=987 S/cm, ever reported for diamond films with excellent Electron field emission (EFE) properties. TEM investigation indicated that these films contain needle-like diamond grains about 5 nm in diameter and hundreds of nanometers in length. Each of the grains was encased in graphitic layers about tens of nano-meters in thickness. These materials properties suitable for more specific applications, such as high conductivity for electron field emitters, high robustness for microplasma cathodes and high electrochemical activity for electro-chemical sensing. Subsequently, other hand, the highly conducting DGH films were coated on vertically aligned ZnO nanorods, there is no prior nucleation or seeding process needed due to the use of BEG method. Such a composite structure provides significant enhancement in the field emission characteristics of the cold cathode was observed with ultralow turn on voltage 1.78 V/μm with high EFE current density of 3.68 mA/ cm2 (at 4.06V/μm) due to decoration of DGH material on ZnO nanorods. The DGH/ZNRs based device get stable emission for longer duration of 562min than bare ZNRs (104min) without any current degradation because the diamond coating protects the ZNRs from ion bombardment when they are used as the cathode for microplasma devices. The potential application of these materials is demonstrated by the plasma illumination measurements that ignited the plasma at the minimum voltage by 290 V. The photoresponse (Iphoto/Idark) behavior of the DGH/ZNRs based photodetectors exhibits a much higher photoresponse (1202) than bare ZNRs (229). During the process the electron transport is easy from ZNRs to DGH through graphitic layers, the EFE properties of these materials comparable to other primarily used field emitters like carbon nanotubes, graphene. The DGH/ZNRs composite also providing a possibility of their use in flat panel, microplasma and vacuum microelectronic devices.

Keywords: bias-enhanced nucleation and growth, ZnO nanorods, electrical conductivity, electron field emission, photo-detectors

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Authors: Alma Gómez-Loredo, José González-Valdez, Jorge Benavides, Marco Rito-Palomares

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Fucoxanthin is a carotenoid that exerts multiple beneficial effects on human health, including antioxidant, anti-cancer, antidiabetic and anti-obesity activity; making the development of a whole process for its production and recovery an important contribution. In this work, the lab-scale production and purification of fucoxanthin in Isocrhysis galbana have been studied. In batch cultures, low light intensities (13.5 μmol/m2s) and bubble agitation were the best conditions for production of the carotenoid with product yields of up to 0.143 mg/g. After fucoxanthin ethanolic extraction from biomass and hexane partition, further recovery and purification of the carotenoid has been accomplished by means of alcohol – salt Aqueous Two-Phase System (ATPS) extraction followed by an ultrafiltration (UF) step. An ATPS comprised of ethanol and potassium phosphate (Volume Ratio (VR) =3; Tie-line Length (TLL) 60% w/w) presented a fucoxanthin recovery yield of 76.24 ± 1.60% among the studied systems and was able to remove 64.89 ± 2.64% of the carotenoid and chlorophyll pollutants. For UF, the addition of ethanol to the original recovered ethanolic ATPS stream to a final relation of 74.15% (w/w) resulted in a reduction of approximately 16% of the protein contents, increasing product purity with a recovery yield of about 63% of the compound in the permeate stream. Considering the production, extraction and primary recovery (ATPS and UF) steps, around a 45% global fucoxanthin recovery should be expected. Although other purification technologies, such as Centrifugal Partition Chromatography are able to obtain fucoxanthin recoveries of up to 83%, the process developed in the present work does not require large volumes of solvents or expensive equipment. Moreover, it has a potential for scale up to commercial scale and represents a cost-effective strategy when compared to traditional separation techniques like chromatography.

Keywords: aqueous two-phase systems, fucoxanthin, Isochrysis galbana, microalgae, ultrafiltration

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Authors: Liang Fang

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The development of the large suburban residential area is a product of the leap development during the rapid urbanization process in China. On the process of the large-scale development of large settlements in a short time, various problems arose in the suburban residential area, such as spatial layout being disorder, basic facilities construction lagging behind and being unreasonable, residential neighborhood space and street culture missing. Aimed at the contradictions mentioned above, exploring a way is imminent to construct appropriate residential area. We select a typical Liangzhu Culture Village in Hangzhou and put forward functional composite residential area of fine development strategy, along which business promotes and assists community autonomy and then a good community culture is constructed. All in all, the development and construction mode, contributing to an all-people and full-time participation, is beneficial to create a harmonious community of sustainable development, which gives good implication to a single enterprise development city real estate projects.

Keywords: community autonomy, development and construction mode, functional composite, suburban large residential area

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Authors: Yas Barzegaar, Atrin Barzegar

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The aim of this research is to develop an intelligent system to analyze the risk level of wheat flour product manufacturing system. The model consists of five Fuzzy Inference Systems in two different layers to analyse the risk of a wheat flour product manufacturing system. The first layer of the model consists of four Fuzzy Inference Systems with three criteria. The output of each one of the Physical, Chemical, Biological and Environmental Failures will be the input of the final manufacturing systems. The proposed model based on Mamdani Fuzzy Inference Systems gives a performance ranking of wheat flour products manufacturing systems. The first step is obtaining data to identify the failure modes from expert’s opinions. The second step is the fuzzification process to convert crisp input to a fuzzy set., then the IF-then fuzzy rule applied through inference engine, and in the final step, the defuzzification process is applied to convert the fuzzy output into real numbers.

Keywords: failure modes, fuzzy rules, fuzzy inference system, risk assessment

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Authors: Lina Lauciene, Vaida Andruleviciute, Ingrida Sinkeviciene, Mindaugas Malakauskas, Loreta Serniene

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Dairy product manufacturers constantly are looking for new markets for their production. And in most cases, the problem of product compliance with the composition requirements of foreign products is highlighted. This is especially true of the composition of milk fat in dairy products. It is well known that there are many factors such as feeding ratio, season, cow breed, stage of lactation that affect the fatty acid composition in milk. However, there is less evidence on the impact of the technological process on the composition of fatty acids in raw milk and products made from it. In this study the influence of the technological process on fat composition in 82% fat butter, 15% fat curd, 3.6% fat yogurt and 2.5% fat UHT milk was determined. The samples were collected at each stage of production, starting with raw milk and ending with the final product in the Lithuanian milk-processing company. Fatty acids methyl esters were quantified using a GC (Clarus 680, Perkin Elmer) equipped with flame ionization detector (FID) and a capillary column SP-2560, 100 m x 0.25 mm id x 0.20 µm. Fatty acids peaks were identified using Supelco® 37 Component FAME Mix. The concentration of each fatty acid was expressed in percent of the total fatty acid amount. In the case of UHT milk production, it was compared raw milk, cream, milk mixture, and UHT milk but significant differences were not estimated between these stages. Analyzing stages of the yogurt production (raw milk, pasteurized milk, and milk with a starter culture and yogurt), no significant changes were detected between stages as well. A slight difference was observed with C4:0 - a percentage of this fatty acid was less (p=0.053) in the final stage than in milk with the starter culture. During butter production, the composition of fatty acids in raw cream, buttermilk, and butter did not change significantly. Only C14:0 decreased in the butter then compared to buttermilk. The curd fatty acid analysis showed the increase of C6:0, C8:0, C10:0, C11:0, C12:0 C14:0 and C17:0 at the final stage when compared to raw milk, cream, milk mixture, and whey. Meantime the increase of C18:1n9c (in comparison with milk mixture and curd) and C18:2n6c (in comparison with raw milk, milk mixture, and curd) was estimated in cream. The results of this study suggest that the technological process did not affect the composition of fatty acids in UHT milk, yogurt, butter, and curd but had the impact on the concentration of individual fatty acids. In general, all of the fatty acids from the raw milk were converted into the final product, only some of them slightly changed the concentration. Therefore, in order to ensure an appropriate composition of certain fatty acids in the final product, producers must carefully choose the raw milk. Acknowledgment: This research was funded by Lithuanian Ministry of Agriculture (No. MT-17-13).

Keywords: dairy products, fat composition, fatty acids, technological process

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Authors: Saima Yaqoob

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Due to advancement in technologies and cutting cost competition, especially in manufacturing business, organizations are now becoming more focused toward achieving exceptional quality standards with low manufacturing cost. In this concern, many process improvement strategies are becoming popular in the way of increasing productivity and output. Lean manufacturing principles are among one of them, increasingly used for improving productivity by reducing wastages. Many success factors are involved in lean implementation. But, the role of senior management is most important in developing the lean culture in an organization. Purpose of this study is to investigate the perception of executive level management related to the successful implementation of lean practices and its comparison with the existing practices in the organization. In order to collect data, survey questionnaire comprised of eight statements rendering the critical success factors were sent to the top management of fifty (50) automotive manufacturing companies of Karachi. After analyzing their feedbacks, the trend of lean manufacturing principles and the commitment of senior management toward its implementation was identified in the manufacturing industries of Karachi, Pakistan.

Keywords: lean manufacturing, process improvement, senior management, perception, involvement, waste reduction

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Authors: Edison A. Bonifaz

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In this work, a numerical procedure is proposed to design dense multi-material structures using the Directed Energy Deposition (DED) process. A thermo-mechanical finite element model to predict thermal cycles and residual stresses is presented. A numerical layer build-up procedure coupled with a moving heat flux was constructed to minimize strains and residual stresses that result in the multi-layer deposition of an AISI 316 austenitic steel on an AISI 304 austenitic steel substrate. To simulate the DED process, the automated interface of the ABAQUS AM module was used to define element activation and heat input event data as a function of time and position. Of this manner, the construction of ABAQUS user-defined subroutines was not necessary. Thermal cycles and thermally induced stresses created during the multi-layer deposition metal AM pool crystallization were predicted and validated. Results were analyzed in three independent metal layers of three different experiments. The one-way heat and material deposition toolpath used in the analysis was created with a MatLab path script. An optimal combination of feedstock and heat input printing parameters suitable for fabricating multi-material dense structures in the directed energy deposition metal AM process was established. At constant power, it can be concluded that the lower the heat input, the lower the peak temperatures and residual stresses. It means that from a design point of view, the one-way heat and material deposition processing toolpath with the higher welding speed should be selected.

Keywords: event series, thermal cycles, residual stresses, multi-pass welding, abaqus am modeler

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Authors: Aibek Kukpayev, Dhawal Shah

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Combustion of sour fuels containing high amount of sulfur leads to the formation of sulfur oxides, which adversely harm the environment and has a negative impact on human health. Considering this, several legislations have been imposed to bring down the sulfur content in fuel to less than 10 ppm. In recent years, novel deep eutectic solvents (DESs) have been developed to achieve deep desulfurization, particularly to extract thiophenic compounds from liquid fuels. These novel DESs, considered as analogous to ionic liquids are green, eco-friendly, inexpensive, and sustainable. We herein, using molecular dynamic simulation, analyze the interactions of metal-based DESs with model oil consisting of thiophenic compounds. The DES used consists of polyethylene glycol (PEG-200) as a hydrogen bond donor, choline chloride (ChCl) or tetrabutyl ammonium chloride (TBAC) as a hydrogen bond acceptor, and cobalt chloride (CoCl₂) as metal salt. In particular, the combination of ChCl: PEG-200:CoCl₂ at a ratio 1:2:1 and the combination of TBAC:PEG-200:CoCl₂ at a ratio 1:2:0.25 were simulated, separately, with model oil consisting of octane and thiophenes at 25ᵒC and 1 bar. The results of molecular dynamics simulations were analyzed in terms of interaction energies between different components. The simulations revealed a stronger interaction between DESs/thiophenes as compared with octane/thiophenes, suggestive of an efficient desulfurization process. In addition, our analysis suggests that the choice of hydrogen bond acceptor strongly influences the efficiency of the desulfurization process. Taken together, the results also show the importance of the metal ion, although present in small amount, in the process, and the role of the polymer in desulfurization of the model fuel.

Keywords: deep eutectic solvents, desulfurization, molecular dynamics simulations, thiophenes

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Authors: Erin M. Durke, Monica L. McEntee, Meilu He, Suresh Dhaniyala

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Aerosols are one of the most important and significant surfaces in the atmosphere. They can influence weather, absorption, and reflection of light, and reactivity of atmospheric constituents. A notable feature of aerosol particles is the presence of a surface charge, a characteristic imparted via the aerosolization process. The existence of charge can complicate the interrogation of aerosol particles, so many researchers remove or neutralize aerosol particles before characterization. However, the charge is present in real-world samples, and likely has an effect on the physical and chemical properties of an aerosolized material. In our studies, we aerosolized different materials in an attempt to characterize the charge imparted via the aerosolization process and determine what impact it has on the aerosolized materials’ properties. The metal oxides, TiO₂ and SiO₂, were aerosolized expulsively and then characterized, using several different techniques, in an effort to determine the surface charge imparted upon the particles via the aerosolization process. Particle charge distribution measurements were conducted via the employment of a custom scanning mobility particle sizer. The results of the charge distribution measurements indicated that expulsive generation of 0.2 µm SiO₂ particles produced aerosols with upwards of 30+ charges on the surface of the particle. Determination of the degree of surface charging led to the use of non-traditional techniques to explore the impact of additional surface charge on the overall reactivity of the metal oxides, specifically TiO₂. TiO₂ was aerosolized, again expulsively, onto a gold-coated tungsten mesh, which was then evaluated with transmission infrared spectroscopy in an ultra-high vacuum environment. The TiO₂ aerosols were exposed to O₂, H₂, and CO, respectively. Exposure to O₂ resulted in a decrease in the overall baseline of the aerosol spectrum, suggesting O₂ removed some of the surface charge imparted during aerosolization. Upon exposure to H₂, there was no observable rise in the baseline of the IR spectrum, as is typically seen for TiO₂, due to the population of electrons into the shallow trapped states and subsequent promotion of the electrons into the conduction band. This result suggests that the additional charge imparted via aerosolization fills the trapped states, therefore no rise is seen upon exposure to H₂. Dosing the TiO₂ aerosols with CO showed no adsorption of CO on the surface, even at lower temperatures (~100 K), indicating the additional charge on the aerosol surface prevents the CO molecules from adsorbing to the TiO₂ surface. The results observed during exposure suggest that the additional charge imparted via aerosolization impacts the interaction with each probe gas.

Keywords: aerosols, charge, reactivity, infrared

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Authors: Bharti Verma, Chandrajit Balomajumder

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Water pollution is escalated owing to industrialization and random ejection of one or more toxic heavy metal ions from the semiconductor industry, electroplating, metallurgical, mining, chemical manufacturing, tannery industries, etc., In semiconductor industry various kinds of chemicals in wafers preparation are used . Fluoride, toxic solvent, heavy metals, dyes and salts, suspended solids and chelating agents may be found in wastewater effluent of semiconductor manufacturing industry. Also in the chrome plating, in the electroplating industry, the effluent contains heavy amounts of Chromium. Since Cr(VI) is highly toxic, its exposure poses an acute risk of health. Also, its chronic exposure can even lead to mutagenesis and carcinogenesis. On the contrary, Cr (III) which is naturally occurring, is much less toxic than Cr(VI). Discharge limit of hexavalent chromium and trivalent chromium are 0.05 mg/L and 5 mg/L, respectively. There are numerous methods such as adsorption, chemical precipitation, membrane filtration, ion exchange, and electrochemical methods for the heavy metal removal. The present study focuses on the removal of Chromium ions by using flat sheet UF5kDa membrane. The Ultra filtration membrane process is operated above micro filtration membrane process. Thus separation achieved may be influenced due to the effect of Sieving and Donnan effect. Ultrafiltration is a promising method for the rejection of heavy metals like chromium, fluoride, cadmium, nickel, arsenic, etc. from effluent water. Benefits behind ultrafiltration process are that the operation is quite simple, the removal efficiency is high as compared to some other methods of removal and it is reliable. Polyamide membranes have been selected for the present study on rejection of Cr(VI) from feed solution. The objective of the current work is to examine the rejection of Cr(VI) from aqueous feed solutions by flat sheet UF5kDa membranes with different parameters such as pressure, feed concentration and pH of the feed. The experiments revealed that with increasing pressure, the removal efficiency of Cr(VI) is increased. Also, the effect of pH of feed solution, the initial dosage of chromium in the feed solution has been studied. The membrane has been characterized by FTIR, SEM and AFM before and after the run. The mass transfer coefficients have been estimated. Membrane transport parameters have been calculated and have been found to be in a good correlation with the applied model.

Keywords: heavy metal removal, membrane process, waste water treatment, ultrafiltration

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Authors: Jefferson Camacho Mejía, Jenny Paola Forero Pachón, Luis Carlos Gómez Flórez

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Action research is a qualitative research methodology, which leads the researcher to delve into the problems of a community in order to understand its needs in depth and finally, to propose actions that lead to a change of social paradigm. Although this methodology had its beginnings in the human sciences, it has attracted increasing interest and acceptance in the field of information systems research since the 1990s. The countless possibilities offered nowadays by the use of Information Technologies (IT) in the development of different socio-economic activities have meant a change of social paradigm and the emergence of the so-called information and knowledge society. According to this, governments, large corporations, small entrepreneurs and in general, organizations of all kinds are using IT to virtualize their processes, taking them from the physical environment to the digital environment. However, there is a potential risk for organizations related with exposing valuable information without an appropriate framework for protecting it. This paper shows progress in the development of a methodological design to manage the information security risks associated with the IT-based processes virtualization, by applying the principles of the action research methodology and it is the result of a systematic review of the scientific literature. This design consists of seven fundamental stages. These are distributed in the three stages described in the action research methodology: 1) Observe, 2) Analyze and 3) Take actions. Finally, this paper aims to offer an alternative tool to traditional information security management methodologies with a view to being applied specifically in the planning stage of IT-based process virtualization in order to foresee risks and to establish security controls before formulating IT solutions in any type of organization.

Keywords: action research, information security, information technology, methodological design, process virtualization, risk management

Procedia PDF Downloads 165

Authors: Gavin Hutama Farandiarta, Hegi Adi Prabowo, Istiara Rizqillah Hanifah, Millati Hanifah Saprudin, Raden Iqrafia Ashna

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The increase of the petroleum’s consumption rate encourages industries to optimize and increase the activity in processing crude oil into petroleum. However, although the result gives a lot of benefits to humans worldwide, it also gives negative impact to the environment. One of the negative impacts of processing crude oil is the soil will be contaminated by petroleum sewage sludge. This petroleum sewage sludge, contains hydrocarbon compound and it can be calculated by Total Petroleum Hydrocarbon (TPH).Petroleum sludge waste is accounted as hazardous and toxic. The soil contamination caused by the petroleum sludge is very hard to get rid of. However, there is a way to manage the soil that is contaminated by petroleum sludge, which is by using heat (thermal desorption) in the process of remediation. There are several factors that affect the success rate of the remediation with the help of heat which are temperature, time, and air pressure in the desorption column. The remediation process using the help of heat is an alternative in soil recovery from the petroleum pollution which highly effective, cheap, and environmentally friendly that produces uncontaminated soil and the petroleum that can be used again.

Keywords: petroleum sewage sludge, remediation soil, thermal desorption, total petroleum hydrocarbon (TPH)

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Authors: Leila Rashidian

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Temperature rise on Earth has had harmful effects on the Earth's surface and has led to change in precipitation patterns all around the world. The present research was aimed to study the process of climate change according to the data simulation in future and compare these parameters with current situation in the studied stations in Semnan province including Garmsar, Shahrood and Semnan. In this regard, LARS-WG software, HADCM₃ model and A₂ scenario were used for the 2010-2030 period. In this model, climatic parameters such as maximum and minimum temperature, precipitation and radiation were used daily. The obtained results indicated that there will be a 4.4% increase in precipitation in Semnan province compared with the observed data, and in general, there will be a 1.9% increase in temperature. This temperature rise has significant impact on precipitation patterns. Most of precipitation will be raining (torrential rains in some cases). According to the results, from west to east, the country will experience more temperature rise and will be warmer.

Keywords: climate change, Semnan province, Lars.WG model, climate parameters, HADCM₃ model

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Authors: Mohammad E. Nikoofal, Mehmet Gumus

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Besides the many benefits of outsourcing, firms are still concerned about the lack of critical information regarding both the risk levels and actions of their suppliers that are just a few links away. In this paper, we study the effectiveness of audit for the manufacturer in managing her supplier’s process improvement effort when the supplier is privately informed about his disruption risk and actions. By comparing the agency costs associated with the optimal menu of contracts with and without audit, we completely characterize the value of audit for all the cases from the perspectives of both manufacturer, and supplier as well as total supply chain. First, the analysis of value of audit from the manufacturer’s perspective shows that she can strictly benefit from auditing her supplier’s actions. To the best of our knowledge, this result has not been documented before in the principal-agent literature under a standard setting where the agent is assumed to be risk-neutral and not protected by limited liability constraints. Second, we find that not only the manufacturer but also the supplier can strictly benefit from audit. Third, the audit enables the manufacturer to customize her contract offerings based on the reliability of the supplier. Finally, by analyzing the impact of problem parameters on the value of audit, we identify the conditions under which an audit would be beneficial for individual supply chain parties as well as total supply chain.

Keywords: supply disruption, adverse selection, moral hazard incentives, audit

Procedia PDF Downloads 462

Authors: Ahmad N. Abu-Baker

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This study investigated the corrosion of a group of heritage silver-copper alloy coins and their conservation treatment by potentiostatic methods. The corrosion products of the coins were characterized by a combination of scanning electron microscopy/ energy-dispersive X-ray spectroscopy (SEM/EDX) and X-ray diffraction (XRD) analyses. Cathodic polarization curves, measured by linear sweep voltammetry (LSV), also identified the corrosion products and the working conditions to treat the coins using a potentiostatic reduction method, which was monitored by chronoamperometry. The corrosion products showed that the decay mechanisms were dominated by selective attack on the copper-rich phases of the silver-copper alloys, which is consistent with an internal galvanic corrosion phenomenon, which leads to the deposition of copper corrosion products on the surface of the coins. Silver chloride was also detected on the coins, which reflects selective corrosion of the silver-rich phases under different chemical environments. The potentiostatic treatment showed excellent effectiveness in determining treatment parameters and monitoring the reduction process of the corrosion products on the coins, which helped to preserve surface details in the cleaning process and to prevent over-treatment.

Keywords: silver alloys, corrosion, conservation, heritage

Procedia PDF Downloads 140

Authors: Hamidrza Joodaki

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The most complex issue in urban land use planning is site selection that needs to assess the verity of elements and factors. Multi Criteria Decision Making (MCDM) methods are the best approach to deal with complex problems. In this paper, combination of the analytical hierarchy process (AHP) model and FUZZY logic was used as MCDM methods to select the best site for gas station in the 4th gas zone of Tehran. The first and the most important step in FUZZY-AHP model is selection of criteria and sub-criteria. Population, accessibility, proximity and natural disasters were considered as the main criteria in this study. After choosing the criteria, they were weighted based on AHP by EXPERT CHOICE software, and FUZZY logic was used to enhance accuracy and to approach the reality. After these steps, criteria layers were produced and weighted based on FUZZY-AHP model in GIS. Finally, through ARC GIS software, the layers were integrated and the 4th gas zone in TEHRAN was selected as the best site to locate gas station.

Keywords: multiple criteria decision making (MCDM), analytic hierarchy process (AHP), FUZZY logic, geographic information system (GIS)

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Authors: Priti Rani, Rajni Johar, P. S. Jassal

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The magnetic chitosan beads (MCB) were synthesized using co-precipitation method and made to react with epichlorohydrin (ECH) to get the cross-linked derivative (ECH-MCB). The beads were characterized by FTIR, SEM, EDX, and TGA. It is found that zinc metal ion sorption efficiency of ECH-MCB is significantly higher than MCB. Various factors affecting the uptake behavior of metal ions, such as pH, adsorbent dosage, contact time, and temperature effects, were investigated. The adsorption parameters fitted well with Langmuir and Freundlich isotherms. The equilibrium parameter RL values support that the adsorption (0 < RL < 1) is favorable and spontaneous process. The thermodynamic parameters confirm that it is an endothermic reaction, which results in an increase in the randomness of adsorption process. The beads were regenerated using ethylene diamine tetraacetic acid (EDTA) for further use. These beads prove as promising materials for the removal of pollutants from industrial wastewater. Water samples from Yamuna and Hindon rivers were analysed for the detection of Zn (II) ions.

Keywords: chitosan magnetic beads, EDTA, epichlorohydrin, removal efficiency

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Authors: Alvarez Barrantes, Robert Dorrell, Christopher Hackney, Anne Baar, Roberto Fernandez, Daniel Parsons

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Microplastic particles entering fluvial environments are deposited with natural sediments. Their settling properties can change by the absorption or adsorption of contaminants, organic matter, and organisms. These deposits include positively, neutrally, and negatively buoyant particles. This study aims to understand how plastic particles of different densities interact with natural sediments as they settle and how they are stored within the sediment deposit. The results of this study contribute to a better understanding of the deposition of microplastic particles and associated pollution in rivers. A set of 48 experiments was designed to investigate the settling process of microplastic particles in freshwater. The experimental work describes the vertical variation of cohesive and/or non-cohesive sediment versus microplastic densities in deposited sediment. The experiment consisted of adding microplastic particles, sediment, and water in a waterproof carton tube of a height of 24 cm and a diameter of 5 cm. The plastic selected is positively, neutrally, and negatively buoyant. The sediments consist of sand and clay with four different concentrations. The mixture of materials was shaken until is thoroughly mixed and left to settle for 24 hours. After the settlement, the tubes were frozen at -20 °C to be able to cut them and measure the thickness of the deposits and analyze the sediment and plastic distribution. The most representative experiments were repeated in a glass tube of the same size; to analyse the influences of current flows and depositional process. Finally, the glass tube experiments were used to study organic materials adsorption in plastic, settling the sample for four months. Defined microplastic layers were identified as the density of the plastic change. Preliminary results show that most of the positive buoyancy particles floated, neutral buoyancy particles form a layer above the sediment and negative buoyancy particles mixed with the sediment. The vertical grain size distribution of the deposits was analysed to determine deposition variation with and without plastic. It is expected that the positively buoyant particles are trapped in the sediment by the currents flows and sink due to organic material adsorption. Finally, the experiments will explain how microplastic particles, including positively buoyant ones, are stored in natural sediment deposits.

Keywords: microplastic adsorption process, microplastic deposition in natural sediment, microplastic pollution in rivers, storages of positive buoyancy microplastic particles

Procedia PDF Downloads 194

Authors: Sara Mostofian

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The nuclear industry is a technology that can fulfill future energy needs but requires special attention to ensure safety and reliability while minimizing any environmental impact. To meet these expectations, the nuclear industry is exploring different reactor technologies for power production. Several designs are under development and the technical viability of these new designs is the subject of many ongoing studies. One of these studies considers the radioactive emissions and radioactive waste generated during the life of a nuclear power production plant to allow a successful license process. For all the modern technologies, a good understanding of the radioactivity generated in the process systems of the plant is essential. Some of that understanding may be gleaned from the performance of some prototype reactors of similar design that operated decades ago. This paper presents how, with that understanding, a model can be developed to estimate the emissions as well as the radioactive waste during the normal operation of a nuclear power plant. The model would predict the radioactive material concentrations in different waste streams. Using this information, the radioactive emission and waste generated during the life of these new technologies can be estimated during the early stages of the design of the plant.

Keywords: SMRs, activity transport, model, radioactive waste

Procedia PDF Downloads 109

Authors: Wheyming Song, Ssu-Ping Lin

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The primary advantage of package-on-package (PoP) packaging is that since it has less volume, it weighs less. But this is also related to its principal drawback, which is warpage. This research investigates how PoP package warpage patterns are affected by assembling process parameters, including substrate temperature, injection speed, injection temperature, and compound forces. We also investigate how warpage patterns are affected by the location of the silicon chip. The methodologies used in this research are design of experiment and warpage simulation via ANSYS. We propose a regression model to predict the warpage value as a function of substrate temperature, injection speed, injection temperature, and compound forces. Our results show that interaction effects exist between substrate temperature and compound forces and between injection speed and injection temperature. Therefore, determining the optimal values for substrate temperature, compound forces, injection speed, and injection temperature cannot be done individually. Also, our results show that the warpage patterns based on the location of silicon chips can be classified into 11 groups, with the largest warpage occurring at the left-most and right-most sides.

Keywords: package-on-package, warpage, design of experiment, simulation

Procedia PDF Downloads 306

Authors: B. Gechbaia, K. Goletiani, G. Gabedava, N. Mikeltadze

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At this stage, Georgia is a country which is actively involved in the European integration process, for which the primary priority is effective integration in the European education system. The modern Georgian higher education system is the process of establishing a new sociocultural reality, whose main priorities are determined by the Quality System as a continuous cycle of planning, implementation, checking and acting. Obviously, in this situation, the issue of management of education institutions comes out in the foreground, since the proper planning and implementation of personnel management processes is one of the main determinants of the company's performance. At the same time, one of the most important factors is the psychological comfort of the personnel, ensuring their protection and efficiency of stress management policy. The purpose of this research is to determine how intensely the relationship is between the psychological comfort of the personnel and the efficiency of the quality system in the institution as the quality assurance mechanisms of educational institutions affect the stability of personnel, prevention and management of the stressful situation. The research was carried out within the framework of the Internal Grant Project «The Role of Organizational Culture in the Process of Settlement of Management of Stress and Conflict, Georgian Reality and European Experience » of the Batumi Navigation Teaching University, based on the analysis of the survey results of target groups. The small-scale research conducted by us has revealed that the introduction of quality assurance system and its active implementation increased the quality of management of Georgian educational institutions, increased the level of universal engagement in internal and external processes and as a result, it has improved the quality of education as well as social and psychological comfort indicators of the society.

Keywords: quality assurance, effective management, stability of personnel, psychological comfort, stress management

Procedia PDF Downloads 155