Search results for: pressure loss coefficients

Authors: K. Rusnakova, D. Gerych, M. Stehlik

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Postural stability is a complex process involving actions of biomechanical, motor, sensory and central nervous system components. Numerous joint systems, muscles involved, the complexity of sporting movements and situations require perfect coordination of the body's movement patterns. To adapt to a constantly changing situation in such a dynamic environment as physical performance, optimal input of information from visual, vestibular and somatosensory sensors are needed. Combat soldiers are required to perform physically and mentally demanding tasks in adverse conditions, and poor postural stability has been identified as a risk factor for lower extremity musculoskeletal injury. The aim of this study is to investigate whether some personality traits are related to the performance of static postural stability among soldiers of combat troops. NEO personality inventory (NEO-PI-R) was used to identify personality traits and the Nintendo Wii Balance Board was used to assess static postural stability of soldiers. Postural stability performance was assessed by changes in center of pressure (CoP) and center of gravity (CoG). A posturographic test was performed for 60 s with eyes opened during quiet upright standing. The results showed that facets of neuroticism and conscientiousness personality traits were significantly correlated with measured parameters of CoP and CoG. This study can help for better understanding the relationship between personality traits and static postural stability. The results can be used to optimize the training process at the individual level.

Keywords: neuroticism, conscientiousness, postural stability, combat troops

Procedia PDF Downloads 135

Authors: Esmaeil Asadzadeh, Mehtab Alam

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Well documented records of the past failures of the structures reveals that the progressive collapse of structures is one of the major reasons for dramatic human loss and economical consequences. Progressive collapse is the failure mechanism in which the structure fails gradually due to the sudden removal of the structural elements. The sudden removal of some structural elements results in the excessive redistributed loads on the others. This sudden removal may be caused by any sudden loading resulted from local explosion, impact loading and terrorist attacks. Hyperbolic thin walled concrete shell structures being an important part of nuclear and thermal power plants are always prone to such terrorist attacks. In concrete structures, the gradual failure would take place by generation of initial cracks and its propagation in the supporting columns along with the tower shell leading to the collapse of the entire structure. In this study the mechanism of progressive collapse for such high raised towers would be simulated employing the finite element method. The aim of this study would be providing clear conceptual step-by-step descriptions of various procedures for progressive collapse analysis using commercially available finite element structural analysis software’s, with the aim that the explanations would be clear enough that they will be readily understandable and will be used by practicing engineers. The study would be carried out in the following procedures: 1. Provide explanations of modeling, simulation and analysis procedures including input screen snapshots; 2. Interpretation of the results and discussions; 3. Conclusions and recommendations.

Keywords: progressive collapse, cooling towers, finite element analysis, crack generation, reinforced concrete

Procedia PDF Downloads 478

Authors: Muganyizi Jonas Bisheko, G. Rejikumar

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Reducing post-harvest losses could be a sustainable solution to enhance the food and income security of smallholder farmers in developing countries. While various research institutions have come up with a number of innovative post-harvest technologies for reducing post-harvest losses, most of them have not been extensively adopted by smallholder farmers. Despite this gap, the synthesized information about the major constraints of post-harvest technology is scarce. This study has been conducted to fill this gap and show the implications of the findings for future post-harvest research. The developed search strategy retrieved 2201 studies. However, after excluding duplicates, title, abstract and full article screening, a total of 41 documents were identified. The major findings are: (i) there is an outstanding deficiency of systematic evidence of the effect of climate change, off-farm income and sources of post-harvest information on the adoption of improved post-harvest technologies; (ii) there is very limited information on adoption constraints pertaining to matters of policy, rules and regulations; (iii) there is very thin literature on behavioral constraints associated with limited adoption of improved post-harvest technologies; (iv) most of the studies focused on post-harvest storage technologies (47%) followed by overall post-harvest management practices (25%), processing technologies (19%) and packaging technologies (3%). Much of the information was found on Cereals (58%), especially maize (44%); (v) geographically, Sub-Saharan Africa accounted for 79% of the reviewed interventions, while South Asia occupied only 21%. The findings of this review are intended to guide various post-harvest technologists and decision-makers in addressing the challenge of huge post-harvest losses.

Keywords: constraints, post-harvest loss, post-harvest technology , smallholder farmer

Procedia PDF Downloads 230

Authors: Guozhen Li, Philip Hall, Nick Miles, Tao Wu, Jie Dong

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This paper presents a Euler-Lagrange model of the water-particles multiphase flows in a Vorsyl separator where particles with different densities are separated. A series of particles with their densities ranging from 760 kg/m³ to 1380 kg/m³ were fed into the Vorsyl separator with water by means of tangential inlet. The simulation showed that the feed materials acquired centrifugal force which allows most portion of the particles with a density less than water to move to the center of the separator, enter the vortex finder and leave the separator through the bottom outlet. While the particles heavier than water move to the wall, reach the throat area and leave the separator through the side outlet. The particles were thus separated and particles collected at the bottom outlet are pure and clean. The influence of particle density on separation efficiency was investigated which demonstrated a positive correlation of the separation efficiency with increasing density difference between medium liquid and the particle. In addition, the influence of the split ratio on the performance was studied which showed that the separation efficiency of the Vorsyl separator can be improved by the increase of split ratio. The simulation also suggested that the Vorsyl separator may not function when the feeding velocity is smaller than a certain critical feeding in velocity. In addition, an increasing feeding velocity gives rise to increased pressure drop, however does not necessarily increase the separation efficiency.

Keywords: Vorsyl separator, separation efficiency, CFD, split ratio

Procedia PDF Downloads 343

Authors: Julius Denafas, Irina Kliopova, Gintaras Denafas

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Three opportunities for implementation of industrial ecology principles in the real industrial production of c-Si solar cells and modules are presented in this study. It includes: material flow dematerialisation, product modification and industrial symbiosis. Firstly, it is shown how the collaboration between R&D institutes and industry helps to achieve significant reduction of material consumption by a) refuse from phosphor silicate glass cleaning process and b) shortening of silicon nitride coating production step. Secondly, it was shown how the modification of solar module design can reduce the CO2 footprint for this product and enhance waste prevention. It was achieved by implementing a frameless glass/glass solar module design instead of glass/backsheet with aluminium frame. Such a design change is possible without purchasing new equipment and without loss of main product properties like efficiency, rigidity and longevity. Thirdly, industrial symbiosis in the solar cell production is possible in such case when manufacturing waste (silicon wafer and solar cell breakage) also used solar modules are collected, sorted and supplied as raw-materials to other companies involved in the production chain of c-Si solar cells. The obtained results showed that solar cells produced from recycled silicon can have a comparable electrical parameters like produced from standard, commercial silicon wafers. The above mentioned work was performed at solar cell producer Soli Tek R&D in the frame of H2020 projects CABRISS and Eco-Solar.

Keywords: manufacturing, process optimisation, recycling, solar cells, solar modules, waste prevention

Procedia PDF Downloads 136

Authors: Obinna K. Ihesiulor, Krishna Shankar, Paul Smith, Alan Fien

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Excessive fretting wear at the taper-trunnion junction (trunnionosis) apparently contributes to the high failure rates of hip implants. Implant wear and corrosion lead to the release of metal particulate debris and subsequent release of metal ions at the taper-trunnion surface. This results in a type of metal poisoning referred to as metallosis. The consequences of metal poisoning include; osteolysis (bone loss), osteoarthritis (pain), aseptic loosening of the prosthesis and revision surgery. Follow up after revision surgery, metal debris particles are commonly found in numerous locations. Background: A stable connection between the femoral ball head (taper) and stem (trunnion) is necessary to prevent relative motions and corrosion at the taper junction. Hence, the importance of component assembly cannot be over-emphasized. Therefore, the aim of this study is to determine the influence of head-stem junction assembly by press fitting and the subsequent disengagement/disassembly on the connection strength between the taper ball head and stem. Methods: CoCr femoral heads were assembled with High stainless hydrogen steel stem (trunnion) by Push-in i.e. press fit; and disengaged by Pull-out test. The strength and stability of the two connections were evaluated by measuring the head pull-out forces according to ISO 7206-10 standards. Findings: The head-stem junction strength linearly increases with assembly forces.

Keywords: wear, modular hip prosthesis, taper head-stem, force assembly and disassembly

Procedia PDF Downloads 393

Authors: Sarra Boughaba

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The α-aminophosphonates have received considerable attention in organic and medicinal chemistry because of their structural resemblance with α-amino acids. They are used as antitumor agents, anti-inflammatory and antibiotics. As a result, a number of procedures have been developed for their synthesis. However, many of these methods suffer from some disadvantages such as long reaction times, environmental pollution caused by utilization of organic solvents, and expensive catalyst. On the other hand, thiazole components, particularly 2-aminothiazole is an important class of heterocyclic compounds. They appear in the structure of natural products and biologically actives compounds, thiamine (vitamin-B), and some antibiotics drugs (penicillin, micrococcin). In the past few years, heteropolyacids have received great attention as environmentally benign catalysts for organic synthetic processes, they possess unique physicochemical properties, such as super-acidity, high thermal and chemical stability, ability to accept and release electrons and high proton mobility, and the possibility of varying their acidity and oxidizing potential. In this study, an efficient and eco-friendly process has been developed for the synthesis of α-aminophosphonates containing aminothiazole moiety via Kabachnik-Field reaction catalyzed by H₆P₂W₁₈O₆₂.14H₂O as reusable catalyst, by condensation of aromatic aldehydes, 2-aminothiazole and triethylphosphite under free conditions. The X-ray crystallographic data of obtained compounds were provided. The main advantages of our protocol include the absence of solvent in the reaction, easy work-up, short reaction time, atom-economy and reusability of catalyst without significant loss of its activity.

Keywords: aminophosphonates, green synthesis, H₆P₂W₁₈O₆₂.14H₂O catalyst, x-ray study

Procedia PDF Downloads 111

Authors: Ahmed Mozamel, Kemal Yildizli

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Due to mechanical energy losses and a competitive of minimizing these losses and increases the machine efficiency, the need for contactless gearing system has raised. In this work, one stage of mechanical planetary gear transmission system integrated with one stage of magnetic planetary gear system is designed as a two-stage hybrid gearbox system. The permanent magnets internal energy in the form of the magnetic field is used to create meshing between contactless magnetic rotors in order to provide self-system protection against overloading and decrease the mechanical loss of the transmission system by eliminating the friction losses. Classical methods, such as analytical, tabular method and the theory of elasticity are used to calculate the planetary gear design parameters. The finite element method (ANSYS Maxwell) is used to predict the behaviors of a magnetic gearing system. The concentric magnetic gearing system has been modeled and analyzed by using 2D finite element method (ANSYS Maxwell). In addition to that, design and manufacturing processes of prototype components (a planetary gear, concentric magnetic gear, shafts and the bearings selection) of a gearbox system are investigated. The output force, the output moment, the output power and efficiency of the hybrid gearbox system are experimentally evaluated. The viability of applying a magnetic force to transmit mechanical power through a non-contact gearing system is presented. The experimental test results show that the system is capable to operate continuously within the range of speed from 400 rpm to 3000 rpm with the reduction ratio of 2:1 and maximum efficiency of 91%.

Keywords: hybrid gearbox, mechanical gearboxes, magnetic gears, magnetic torque

Procedia PDF Downloads 150

Authors: Geeta Kumari, Prabu Vairakannu

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Coal is the largest fossil fuel. In India, around 37 % of coal resources found at a depth of more than 300 meters. In India, more than 70% of electricity production depends on coal. Coal on combustion produces greenhouse and pollutant gases such as CO₂, SOₓ, NOₓ, and H₂S etc. Underground coal gasification (UCG) technology is an efficient and an economic in-situ clean coal technology, which converts these unmineable coals into valuable calorific gases. The UCG syngas (mainly H₂, CO, CH₄ and some lighter hydrocarbons) which can utilized for the production of electricity and manufacturing of various useful chemical feedstock. It is an inherent clean coal technology as it avoids ash disposal, mining, transportation and storage problems. Gasification of underground coal using steam as a gasifying medium is not an easy process because sending superheated steam to deep underground coal leads to major transportation difficulties and cost effective. Therefore, for reducing this problem, we have used CO₂ as a gasifying medium, which is a major greenhouse gas. This paper focus laboratory scale underground coal gasification experiment on a coal block by using CO₂ as a gasifying medium. In the present experiment, first, we inject oxygen for combustion for 1 hour and when the temperature of the zones reached to more than 1000 ºC, and then we started supplying of CO₂ as a gasifying medium. The gasification experiment was performed at an atmospheric pressure of CO₂, and it was found that the amount of CO produced due to Boudouard reaction (C+CO₂  2CO) is around 35%. The experiment conducted to almost 5 hours. The maximum gas composition observed, 35% CO, 22 % H₂, and 11% CH4 with LHV 248.1 kJ/mol at CO₂/O₂ ratio 0.4 by volume.

Keywords: underground coal gasification, clean coal technology, calorific value, syngas

Procedia PDF Downloads 225

Authors: Chien-Kuo Chang, You-Syuan Wu, Min-Chiu Wu, Bharath-Kumar Boyanapalli

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The electrical treeing mechanism in epoxy resin insulation is a critical area of study concerning the degradation of high-voltage electrical equipment. In this study, we conducted pressure-induced degradation experiments on epoxy resin specimens using a needle-plane electrode structure to simulate electrical treeing. The specimens featured two different defect spacings, allowing for detailed observation facilitated by time-lapse photography. Our investigation revealed four distinct stages of insulation degradation: initial dark tree growth, filamentary tree growth, reverse tree growth, and eventual insulation breakdown. The initial dark treeing stage, though shortest in duration, exhibited a thicker main branch and shorter branching, ceasing upon the appearance of filamentary treeing. Filamentary treeing manifested in two forms: dark filamentary treeing during the resin's glassy state, characterized by branching structures, and fuzzy filamentary treeing during the rubbery state, resembling white feathers. The channels formed by filamentary treeing were observed to be as narrow as a few micrometers and continued to grow until the end of the experiment. Additionally, the transition to reverse treeing occurred when filamentary treeing reached the ground electrode, with the earliest manifestation being growth from the ground electrode towards the high-voltage end.

Keywords: epoxy resin insulation, high-voltage equipment, electrical treeing mechanism

Procedia PDF Downloads 71

Authors: Panasbodee Thachaopas, Duangdorm Gamnerdsap, Waraporn Inthip, Arissara Pungpa

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LDD’s IM Farm or Land Development Department’s Integrated Management Farm is the agricultural simulation application developed by Land Development Department relies on actual data in simulation game to grow 12 cash crops which are rice, corn, cassava, sugarcane, soybean, rubber tree, oil palm, pineapple, longan, rambutan, durian, and mangosteen. Launching in simulation game, players could select preferable areas for cropping from base map or Orthophoto map scale 1:4,000. Farm management is simulated from field preparation to harvesting. The system uses soil group, and present land use database to facilitate player to know whether what kind of crop is suitable to grow in each soil groups and integrate LDD’s data with other agencies which are soil types, soil properties, soil problems, climate, cultivation cost, fertilizer use, fertilizer price, socio-economic data, plant diseases, weed, pest, interest rate for taking on loan from Bank for Agriculture and Agricultural Cooperatives (BAAC), labor cost, market prices. These mentioned data affect the cost and yield differently to each crop. After completing, the player will know the yield, income and expense, profit/loss. The player could change to other crops that are more suitable to soil groups for optimal yields and profits.

Keywords: agricultural simulation, smart farmer, web application, factors of agricultural production

Procedia PDF Downloads 195

Authors: Sepideh Jabbari Behnam, Shadabeh Gashtasbi Iraei, Elnaz Mohsenin, MohammadAli Aghajani

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Urban neighborhoods, as important urban forming cells, play a key role in creating urban texture and integrated form. Nowadays, most of neighborhood divisions are based on urban management systems but without considering social issues and the other aspects of urban life. This can cause problems such as providing inappropriate services for city dwellers, the loss of local identity and etc. In this regard for regenerating of such neighborhoods, it is essential to locate neighborhood centers with appropriate access and services for all residents. The main objective of this article is reaching to the location of neighborhood centers in a way that, most of issues relating to the physical features (such as the form of access network and texture permeability and etc.) and other qualities such as land uses, densities and social and economic features can be done simultaneously. This paper attempts to use methods of spatial analysis in order to surveying spatial structure and space syntax of urban textures and Urban Network Analysis Systems. This can be done by one of GIS toolbars which is named UNA (Urban Network Analysis) with the use of its five functions (include: Reach, Betweenness, Gravity, Closeness, Straightness).These functions were written according to space syntax theory and offer its relating output. This paper tries to locate and evaluate the optimal location of neighborhood centers in order to create local centers. This is done through weighing of each of these functions and taking into account of spatial features.

Keywords: evaluate optimal location, Local centers, location of neighborhood centers, Spatial analysis, Urban network

Procedia PDF Downloads 460

Authors: Pawitchaya Srijaiwong, Surin Khomfoi

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There are several solutions to supply electricity to an island in Thailand such as diesel generation, submarine power cable, and renewable energy power generation. However, each alternative has its own limitation like fuel and pollution of diesel generation, submarine power cable length resulting in loss of cable and cost of investment, and potential of renewable energy in the local area. This paper shows microgrid system which is a new alternative for power supply to an island. It integrates local power plant from renewable energy, energy storage system, and microgrid controller. The suitable renewable energy power generation on an island is selected from geographic location and potential evaluation. Thus, photovoltaic system and hydro power plant are taken into account. The capacity of energy storage system is also estimated by transient stability study in order to supply electricity demand sufficiently under normal condition. Microgrid controller plays an important role in conducting, communicating and operating for both sources and loads on an island so that its functions are discussed in this study. The conceptual design of microgrid operation is investigated in order to analyze the reliability and power quality. The result of this study shows that microgrid is able to operate in parallel with the main grid and in case of islanding. It is applicable for electricity supply to an island and a remote area. The advantages of operating microgrid on an island include the technical aspect like improving reliability and quality of power system and social aspects like outage cost saving and CO₂ reduction.

Keywords: energy storage, islanding, microgrid, renewable energy

Procedia PDF Downloads 323

Authors: R. C. Law, Shirley Kang, T. Y. Hin, M. Z. Abdullah

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LED technology has been evolving aggressively in recent years from incandescent bulb during older days to as small as chip scale package. It will continue to stay bright in future. As such, there is tremendous pressure to stay competitive in the market by optimizing products to next level of performance and reliability with the shortest time to market. This changes the conventional way of product design and development to virtual prototyping by means of Computer Aided Engineering (CAE). It comprises of the deployment of Finite Element Method (FEM) and Computational Fluid Dynamic (CFD). FEM accelerates the investigation for early detection of failures such as crack, improve the thermal performance of system and enhance solder joint reliability. CFD helps to simulate the flow pattern of molding material as a function of different temperature, molding parameters settings to evaluate failures like voids and displacement. This paper will briefly discuss the procedures and applications of FEM in thermal stress, solder joint reliability and CFD of compression molding in LED CSP. Integration of virtual prototyping in product development had greatly reduced the time to market. Many successful achievements with minimized number of evaluation iterations required in the scope of material, process setting, and package architecture variant have been materialized with this approach.

Keywords: LED, chip scale packaging (CSP), computational fluid dynamic (CFD), virtual prototyping

Procedia PDF Downloads 284

Authors: Allyne Topaz

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Intraoral dehiscence compromises free fibula flaps following mandibular reconstruction. Salivary contamination risks thrombosis of microvascular anastomosis and hardware infection. The superficial temporal artery islandized flap (STAIF) offers an efficient, non-microsurgical reconstructive option for regaining intraoral competency for a time sensitive complication. Methods: The STAIF flap is based on the superficial temporal artery coursing along the anterior hairline. The flap is mapped with assistance of the doppler probe. The width of the skin paddle is taken based on the ability to close the donor site. The flap is taken down to the level of the zygomatic arch and tunneled into the mouth. Results: We present a case of a patient who underwent mandibular reconstruction with a free fibula flap after a traumatic shotgun wound. The patient developed repeated intraoral dehiscence following failed local buccal and floor of mouth flaps leading to salivary contamination of the flap and hardware. The intraoral dehiscence was successfully salvaged on the third attempt with a STAIF flap. Conclusions: Intraoral dehiscence creates a complication requiring urgent attention to prevent loss of free fibula flap after mandibular reconstruction. The STAIF is a non-microsurgical option for restoring intraoral competency. This robust, axially vascularized skin paddle may be split for intra- and extra-oral coverage, as needed and can be an important tool in the reconstructive armamentarium.

Keywords: free fibula flap, intraoral dehiscence, mandibular reconstruction, superficial temporal artery islandized flap

Procedia PDF Downloads 131

Authors: Kunthida Kulprateepunya, Napat Boontiam, Bunthita Phuasa, Chatsuda Kankayant, Bantoeng Polsawat, Sumran Poontong

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Frailty is the thin line between good health and illness. The syndrome is more common in the elderly who transition from strong to weak. (Vulnerability). Fragility can prevent and promote healthy recovery before it goes into disability. This research and development aim to analyze the situation analysis of frailty of the elderly, develop a program, and evaluate the effect of a health promotion program to prevent and solve the problem of frailty among the elderly. The research consisted of 3 phases: 1) analysis of the frailty situation, 2) development of a model, 3) evaluation of the effectiveness of the model. Samples were 328, 122 elderlies using the multi-stage random sampling method. The research instrument was a frailty questionnaire use of the five symptoms, the main characteristics were muscle weakness, slow walking, low physical activity. Fatigue and unintentional weight loss, criteria frailty use more than or equal to three or more symptoms are frailty. Data were analyzed by descriptive and t-test dependent test statistics. The findings showed three parts. First, frailty in the elderly was 23.05 percentage and 56.70% pre-frailty. Second, it was development of a health promotion program to prevent and solve the problem of frailty the elderly with a combination of Nine-Square Exercise, Elastic Band Exercise, Elastic Coconut Shell. Third, evaluation of the effectiveness of the model by comparison of the elderly's get up and go test, the average time before using the program was 14.42 and after using the program was 8.57. It was statistically significant at the .05 level. In conclusion, the findings can used to develop guidelines to promote the health of the frailty elderly.

Keywords: elderly, fragile, nine-square exercise, elastic coconut shell

Procedia PDF Downloads 103

Authors: F. Deng, R. Sanchez, A. Beltran, S. Maestre

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The high nutritional value associated with seafood is related to the presence of essential trace elements. Moreover, seafood is considered an important source of energy, proteins, and long-chain polyunsaturated fatty acids. Generally, seafood is consumed cooked. Consequently, the nutritional value could be degraded. Seafood, such as fish, shellfish, and seaweed, could be considered as one of the main iodine sources. The deficient or excessive consumption of iodine could cause dysfunction and pathologies related to the thyroid gland. The main objective of this work is to evaluated iodine stability in hake (Merluccius) undergone different culinary techniques. The culinary process considered were: boiling, steaming, microwave cooking, baking, cooking en papillote (twisted cover with the shape of a sweet wrapper) and coating with a batter of flour and deep-frying. The determination of iodine was carried by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Regarding sample handling strategies, liquid-liquid extraction has demonstrated to be a powerful pre-concentration and clean-up approach for trace metal analysis by ICP techniques. Extraction with tetramethylammonium hydroxide (TMAH reagent) was used as a sample preparation method in this work. Based on the results, it can be concluded that the stability of iodine was degraded with the cooking processes. The major degradation was observed for the boiling and microwave cooking processes. The content of iodine in hake decreased up to 60% and 52%, respectively. However, if the boiling cooking liquid is preserved, this loss that has been generated during cooking is reduced. Only when the fish was cooked by following the cooking en papillote process the iodine content was preserved.

Keywords: cooking process, ICP-MS, iodine, hake

Procedia PDF Downloads 137

Authors: Bhavita S. Dave, Chandresh H. Solanki, Atul K. Desai

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Soils of Greater Himalayas mostly pertain to Leh & Ladakh, Lahaul & Sppiti, & high reaches to Uttarakhand. The moisture regime is aridic. The arid zone starts from Baralacha pass in Lahaul and covers the entire Spiti valley in the district of Lahaul & Spiti, Himachal Pradesh of India. Here, the present study is an attempt to determine the suction value of soil collected from the arid zone of Spiti valley for different freezing-thawing cycles considering the climate ranges of Spiti valley. Suction is the basic and most important parameter which influences the behavior of unsaturated soil. It is essential to determine the suction value of unsaturated soil before other tests like shear test, and permeability. Basically, it is the negative pore water pressure in partially saturated soil measured in terms of the height of the water column. The filter paper method has been used for the study as an economical approach to evaluate suction. It is the only method from which both contact and non-contact suction can be deduced. In this study, soil specimens were subjected to 0, 1, 3, & 5 freezing-thawing (F-T) cycles for different degrees of saturation to have a wide range of suction, and soil freezing characteristic curves (SFCC) were formulated for all F-T cycles. The result data collected from the experiments have shown best-fitted values using Fredlund & Xing model for each SFCC.

Keywords: suction, arid region soil, soil freezing characteristic curve, freezing-thawing cycle

Procedia PDF Downloads 223

Authors: Rogelio Omar Corona-Núñez, Alma Mendoza-Ponce

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The Tropical Dry Forest not only is one of the most important tropical ecosystems in terms of area, but also it is one of the most degraded ecosystems. However, little is known about the degradation impacts on carbon stocks, therefore in carbon emissions. There are different studies which explain its deforestation dynamics, but there is still a lack of understanding of how they correlate to carbon losses. Recently different authors have built current biomass maps for the tropics and Mexico. However, it is not clear how well they predict at the local scale, and how they can be used to estimate carbon emissions. This study quantifies the forest net carbon losses by comparing the potential carbon stocks and the different current biomass maps in the Southern Pacific coast in Oaxaca, Mexico. The results show important differences in the current biomass estimates with not a clear agreement. However, by the aggregation of the information, it is possible to infer the general patterns of biomass distribution and it can identify the driving forces of the carbon emissions. This study estimated that currently ~44% of the potential carbon stock estimated for the region is still present. A total of 6,764 GgC has been emitted due to deforestation and degradation of the forest at a rate of above ground biomass loss of 66.4 Mg ha-1. Which, ~62% of the total carbon emissions can be regarded as being due to forest degradation. Most of carbon losses were identified in places suitable for agriculture, close to rural areas and to roads while the lowest losses were accounted in places with high water stress and within the boundaries of the National Protected Area. Moreover, places not suitable for agriculture, but close to the coast showed carbon losses as a result of urban settlements.

Keywords: above ground biomass, deforestation, degradation, driving forces, tropical deciduous forest

Procedia PDF Downloads 181

Authors: Hala Demerdash, Ola M. Zanaty, Emad Eldin Arida

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Background: This study investigated the micoRNA expression changes induced by Sevoflurane and Propofol and their effects on liver functions. Patients and methods: The study was designed as randomized controlled study, carried out on 200 adult patients, scheduled for major surgeries under general anesthesia (GA). Patients were randomly divided into four groups; groups SC and PC included chronic hepatitis C (CHC) patients where SC group are patients receiving Sevoflurane, and PC group are patients receiving Propofol anesthesia. While S and P groups included non- hepatitis patients; S group are patients receiving Sevoflurane and P group are patients receiving Propofol. Anesthesia in Group S and SC patients was maintained by sevoflurane, while anesthesia in Group P and PC patients was maintained by propofol infusion. Blood samples were analyzed for PT, PTT and liver enzymes. Serum samples were analyzed for microRNA before and after surgery. Results: Results show miRNA-122 and miRNA-21 were absent in serum of S and P groups in pre-operative samples. However, they were expressed in SC and PC groups. In post-operative samples; miRNA-122 revealed an increased expression in all groups; with more exaggerated response in SC group. On the other hand miRNA-21 revealed increased expression in both SC and PC groups; a slight expression in S group with absent expression in P group. There was a post-operative negative correlation between miR-122 and ALT (r=-0.46) in SC group and (r=-0.411) in PC group and positive correlation between ALT and miR-21 (r=0.335) in SC group and (r=0.379) in PC group. The amount of blood loss was positively correlated with miR-122 (r=0.366) in SC group and (r=0.384) in PC group. Conclusion: Propofol anesthesia is safer than Sevoflurane anesthesia in patients with CHC. Sevoflurane and Propofol anesthesia affect miRNA expression in both CHC and non-hepatitis patients.

Keywords: anesthesia, chronic hepatitis C, micoRNA, propofol, sevoflurane

Procedia PDF Downloads 339

Authors: Warda L. Panondi, Norihiro Izumi

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Sedimentation is a significant threat to the sustainability of reservoirs and their watershed. In the Philippines, the Pulangi watershed experienced a high sediment loss mainly due to land conversions and plantations that showed critical erosion rates beyond the tolerable limit of -10 ton/ha/yr in all of its sub-basin. From this event, the prediction of runoff volume and sediment yield is essential to examine using the country's soil conservation techniques realistically. In this research, the Pulangi watershed was modeled using the soil water assessment tool (SWAT) to predict its watershed basin's annual runoff and sediment yield. For the calibration and validation of the model, the SWAT-CUP was utilized. The model was calibrated with monthly discharge data for 1990-1993 and validated for 1994-1997. Simultaneously, the sediment yield was calibrated in 2014 and validated in 2015 because of limited observed datasets. Uncertainty analysis and calculation of efficiency indexes were accomplished through the SUFI-2 algorithm. According to the coefficient of determination (R2), Nash Sutcliffe efficiency (NSE), King-Gupta efficiency (KGE), and PBIAS, the calculation of streamflow indicates a good performance for both calibration and validation periods while the sediment yield resulted in a satisfactory performance for both calibration and validation. Therefore, this study was able to identify the most critical sub-basin and severe needs of soil conservation. Furthermore, this study will provide baseline information to prevent floods and landslides and serve as a useful reference for land-use policies and watershed management and sustainability in the Pulangi watershed.

Keywords: Pulangi watershed, sediment yield, streamflow, SWAT model

Procedia PDF Downloads 202

Authors: Deepika, Kashika Kapoor, Nistha Khanna, Lakshmi, Archna Kumar

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Plant-parasitic nematodes cause major loss in global food production and destroying at least 21.3% of food annually. About 4100 species of plant-parasitic nematodes are reported, out of this, Meloidogyne species is prominent and worldwide in distribution. Observing the harmful effects of chemical based nematicides, there is a great need for an eco-friendly, highly efficient, sustainable control measure for Meloidogyne. Therefore, In vitro study was carried out to observe the impact of volatile cues obtained from the Tagetes erecta leaves on plant parasitic nematodes. Volatile cues were collected from marigold leaves. For chemical characterization, GCMS (Gas Chromatography Mass Spectrometry) profiling was conducted. VOCs (Volatile Organic Compounds) profile of marigold indicated the presence of several types of alkanes, alkenes varying in number and quantity. Status of nematodes population by counting the live and dead individuals after applying a definite volume (100µl) of extract was recorded at different concentrations (100%, 50%, 25%) with contrast of control (hexane) during different time durations i.e.,24hr, 48hr and 72hr. Result indicated that mortality increases with increasing time (72hr) and concentration (100%) i.e., 50%. Thus, application of prominent compound present in Marigold in pure form may be tested individually or in combination to find out the most efficient active compound/s, which may be highly useful in eco-friendly management of targeted plant parasitic nematode.

Keywords: plant-parasitic nematode, meloidogyne, tagetes erecta, volatile organic compounds

Procedia PDF Downloads 162

Authors: Georgi Vendramin, Aurea Lúcia, Yamamoto, Carlos Itsuo, Souza Melegari, N. Samuel

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This article describes the development of a model that uses a method where openings are represented by single glass and double glass. The model is based on a healthy balance equations purely theoretical and empirical data. Simplified equations are derived through a synthesis of the measured data obtained from meteorological stations. The implementation of the model in a design tool integrated buildings is discussed in this article, to better punctuate the requirements of comfort and energy efficiency in architecture and engineering. Sustainability, energy efficiency, and the integration of alternative energy systems and concepts are beginning to be incorporated into designs for new buildings and renovations to existing buildings. Few means have existed to effectively validate the potential performance benefits of the design concepts. It was used a method of degree-days for an assessment of the energy performance of a building showed that the design of the architectural design should always be considered the materials used and the size of the openings. The energy performance was obtained through the model, considering the location of the building Central Park Shopping Mall, in the city of Cascavel - PR. Obtained climatic data of these locations and in a second step, it was obtained the coefficient of total heat loss in the building pre-established so evaluating the thermal comfort and energy performance. This means that the more openings in buildings in Cascavel – PR, installed to the east side, they may be higher because the glass added to the geometry of architectural spaces will cause the environment conserve energy.

Keywords: sustainable design, energy modeling, design validation, degree-days methods

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Authors: John P. Ulhøi

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Firms are faced with pressure to stay innovative and entrepreneurial while at the same time leaving lighter ecological footprints. Traditionally inspiration for new product development (NPD) has come from the creative in-house staff and from the marketplace. Often NPD offered by this approach has proven to be (far from) optimal for its purpose or highly (resource and energy) efficient. More recently, a bio-inspired NPD approach has surfaced under the banner of biomimetics. Biomimetics refers to inspiration from and translations of designs, systems, processes, and or specific properties that exist in nature. The principles and structures working in nature have evolved over a long period of time enable them to be optimized for the purpose and resource and energy-efficient. These characteristics reflect the raison d'être behind the field of biomimetics. While biological expertise is required to understand and explain such natural and biological principles and structures, engineers are needed to translate biological design and processes into synthetic applications. It can, therefore, hardly be surprising, biomimetics long has gained a solid foothold in both biology and engineering. The commercial adoption of biomimetic applications in new production development (NDP) in industry, however, does not quite reflect a similar growth. Differently put, this situation suggests that something is missing in the biomimetic-NPD-equation, thus acting as a brake towards the wider commercial application of biomimetics and thus the use of eco-materials and design in the industry. This paper closes some of that gap. Before concluding, avenues for future research and implications for practice will be briefly sketched out.

Keywords: biomimetics, eco-materials, NPD, commercialization

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Authors: jihen ayadi sellami

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The rapid evolution of the global financial landscape has led to increased attention to corporate tax policies and the need to understand the factors that influence their tax behavior. In order to mitigate any residual loss for shareholders resulting from tax aggressiveness and resolve the agency problem, appropriate systems that separate the function of management from that of controlling are needed. In this context of growing concerns to limit aggressive corporate taxation practices through governance, this study discusses. Its aims is to examine the influence of six key characteristics of the board of directors (board size, diligence, CEO duality, presence of audit committees, gender diversity and independence of directors), given a governance mechanism, on the tax decisions of non-financial corporations in the United State. In fact, using a sample of 90 non-financial US firms from S&P 500 over a period of 4 years going from 2014 to 2017, the results based on a multivariate linear regression highlight significant associations between these characteristics and corporate tax policy. Notably, larger board, gender diversity, diligence and increased director independence appear to play an important role in reducing aggressive taxation. While duality has a positive and significant correlation with tax aggressiveness, that can be explained by the fact that the manager did properly exploit his specific position within the company. These findings contribute to a deeper understanding of how board characteristics can influence corporate tax management, providing avenues for more effective corporate governance and more responsible tax decision-making

Keywords: tax aggressiveness, board of directors, board size, CEO duality, audit committees, gender diversity, director independence, diligence, corporate governance, united states

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Authors: Abdellatif Chebboub

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Agricultural production is sensitive to weather and thus directly affected by climate change. Plausible estimates of these climate change impacts require combined use of climate, crop, and economic models. Results from previous studies vary substantially due to differences in models, scenarios, and data. This paper is part of a collective effort to systematically integrate these three types of models. We focus on the economic component of the assessment, investigating how nine global economic models of agriculture represent endogenous responses to seven standardized climate change scenarios produced by two climate and five crop models. These responses include adjustments in yields, area, consumption, and international trade. We apply biophysical shocks derived from the Intergovernmental Panel on Climate Change’s representative concentration pathway with end-of-century radiative forcing of 8.5 W/m2. The mean biophysical yield effect with no incremental CO2 fertilization is a 17% reduction globally by 2050 relative to a scenario with unchanging climate. Endogenous economic responses reduce yield loss to 11%, increase area of major crops by 11%, and reduce consumption by 3%. Agricultural production, cropland area, trade, and prices show the greatest degree of variability in response to climate change, and consumption the lowest. The sources of these differences include model structure and specification; in particular, model assumptions about ease of land use conversion, intensification, and trade. This study identifies where models disagree on the relative responses to climate shocks and highlights research activities needed to improve the representation of agricultural adaptation responses to climate change.

Keywords: climate change, agriculture, weather change, danger of climate change

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Authors: Lenuta Kloetzer, Alexandra C. Blaga, Dan Cascaval, Alexandra Tucaliuc, Anca I. Galaction

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Rosmarinic acid, an ester of caffeic acid and 3-(3,4-dihydroxyphenyl) lactic acid, is considered a valuable compound for the pharmaceutical and cosmetic industries due to its antimicrobial, antioxidant, antiviral, anti-allergic, and anti-inflammatory effects. It can be obtained by extraction from vegetable or animal materials, by chemical synthesis and biosynthesis. Indifferent of the method used for rosmarinic acid production, the separation and purification process implies high amount of raw materials and laborious stages leading to high cost for and limitations of the separation technology. This study focused on separation of rosmarinic acid by synergic reactive extraction with a mixture of two extractants, one acidic (acid di-(2ethylhexyl) phosphoric acid, D2EHPA) and one with basic character (Amberlite LA-2). The studies were performed in experimental equipment consisting of an extraction column where the phases’ mixing was made by mean of a perforated disk with 45 mm diameter and 20% free section, maintained at the initial contact interface between the aqueous and organic phases. The vibrations had a frequency of 50 s⁻¹ and 5 mm amplitude. The extraction was carried out in two solvents with different dielectric constants (n-heptane and dichloromethane) in which the extractants mixture of varying concentration was dissolved. The pH-value of initial aqueous solution was varied between 1 and 7. The efficiency of the studied extraction systems was quantified by distribution and synergic coefficients. For calculating these parameters, the rosmarinic acid concentration in the initial aqueous solution and in the raffinate have been measured by HPLC. The influences of extractants concentrations and solvent polarity on the efficiency of rosmarinic acid separation by synergic extraction with a mixture of Amberlite LA-2 and D2EHPA have been analyzed. In the reactive extraction system with a constant concentration of Amberlite LA-2 in the organic phase, the increase of D2EHPA concentration leads to decrease of the synergic coefficient. This is because the increase of D2EHPA concentration prevents the formation of amine adducts and, consequently, affects the hydrophobicity of the interfacial complex with rosmarinic acid. For these reasons, the diminution of synergic coefficient is more important for dichloromethane. By maintaining a constant value of D2EHPA concentration and increasing the concentration of Amberlite LA-2, the synergic coefficient could become higher than 1, its highest values being reached for n-heptane. Depending on the solvent polarity and D2EHPA amount in the solvent phase, the synergic effect is observed for Amberlite LA-2 concentrations over 20 g/l dissolved in n-heptane. Thus, by increasing the concentration of D2EHPA from 5 to 40 g/l, the minimum concentration value of Amberlite LA-2 corresponding to synergism increases from 20 to 40 g/l for the solvent with lower polarity, namely, n-heptane, while there is no synergic effect recorded for dichloromethane. By analysing the influences of the main factors (organic phase polarity, extractant concentration in the mixture) on the efficiency of synergic extraction of rosmarinic acid, the most important synergic effect was found to correspond to the extractants mixture containing 5 g/l D2EHPA and 40 g/l Amberlite LA-2 dissolved in n-heptane.

Keywords: Amberlite LA-2, di(2-ethylhexyl) phosphoric acid, rosmarinic acid, synergic effect

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Authors: Ahmed Ramadhan Al-Obaidi, Jassim Alhamid

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In this investigation, the flow pattern, characteristics of thermal-hydraulic, and improvement of heat transfer performance are evaluated using a numerical technique in three dimensions corrugated pipe heat exchanger. The modification was made under different corrugated pipe geometrical parameters, including corrugated ring angle (CRA), distance between corrugated ring (DBCR), and corrugated diameter (CD), the range of Re number from 2000 to 12000. The numerical results are validated with available experimental data. The numerical outcomes reveal that there is an important change in flow field behaviour and a significant increase in friction factor and improvement in heat transfer performance owing to the use of the corrugated shape in the heat exchanger pipe as compared to the conventional smooth pipe. Using corrugated pipe with different configurations makes the flow more turbulence, flow separation, boundary layer distribution, flow mixing, and that leads to augmenting the performance of heat transfer. Moreover, the value of pressure drop, and the Nusselt number increases as the corrugated pipe geometrical parameters increase. Furthermore, the corrugation configuration shapes have an important influence on the thermal evaluation performance factor, and the maximum value was more than 1.3. Numerical simulation can be performed to predict the various geometrical configurations effects on fluid flow, thermal performance, and heat transfer enhancement.

Keywords: corrugated ring angle, corrugated diameter, Nusselt number, heat transfer

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Authors: Armanul Hoque Shaon, Md Baizid Mahmud, Askander Nobi, Md. Raju Ahmed, Md. Jiabul Hoque

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In the Internet of Things (IoT), devices are linked to the internet through a wireless network, allowing them to collect and transmit data without the need for a human operator. Agriculture relies heavily on wireless sensors, which are a vital component of the Internet of Things (IoT). This kind of wireless sensor network monitors physical or environmental variables like temperatures, sound, vibration, pressure, or motion without relying on a central location or sink and collaboratively passes its data across the network to be analyzed. As the primary source of plant nutrients, the soil is critical to the agricultural industry's continued growth. We're excited about the prospect of developing an Internet of Things (IoT) solution. To arrange the network, the sink node collects groundwater levels and sends them to the Gateway, which centralizes the data and forwards it to the sensor nodes. The sink node gathers soil moisture data, transmits the mean to the Gateways, and then forwards it to the website for dissemination. The web server is in charge of storing and presenting the moisture in the soil data to the web application's users. Soil characteristics may be collected using a networked method that we developed to improve rice production. Paddy land is running out as the population of our nation grows. The success of this project will be dependent on the appropriate use of the existing land base.

Keywords: IoT based agriculture monitoring, intelligent irrigation, communicating network, rice production

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Authors: E. E. S. Uy, T. Noda, K. Nakai, J. R. Dungca

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Cyclic threshold shear strain is the cyclic shear strain amplitude that serves as the indicator of the development of pore water pressure. The parameter can be obtained by performing either cyclic triaxial test, shaking table test, cyclic simple shear or resonant column. In a cyclic triaxial test, other researchers install measuring devices in close proximity of the soil to measure the parameter. In this study, an attempt was made to estimate the cyclic threshold shear strain parameter using full-field measurement technique. The technique uses a camera to monitor and measure the movement of the soil. For this study, the technique was incorporated in a strain-controlled consolidated undrained cyclic triaxial test. Calibration of the camera was first performed to ensure that the camera can properly measure the deformation under cyclic loading. Its capacity to measure deformation was also investigated using a cylindrical rubber dummy. Two-dimensional image processing was implemented. Lucas and Kanade optical flow algorithm was applied to track the movement of the soil particles. Results from the full-field measurement technique were compared with the results from the linear variable displacement transducer. A range of values was determined from the estimation. This was due to the nonhomogeneous deformation of the soil observed during the cyclic loading. The minimum values were in the order of 10-2% in some areas of the specimen.

Keywords: cyclic loading, cyclic threshold shear strain, full-field measurement, optical flow

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