Search results for: Heavy metal recovery

Authors: Bamikole J. Adeyemi, Prashant Jadhawar, Lateef Akanji

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Theoretically, there exist two mathematical interfaces (fluid-solid and fluid-fluid) when a liquid film is present on solid surfaces. These interfaces overlap if the mineral surface is oil-wet or mixed wet, and therefore, the effects of disjoining pressure are significant on both boundaries. Hence, dewetting is a necessary process that could detach oil from the mineral surface. However, if the thickness of the thin water film directly in contact with the surface is large enough, disjoining pressure can be thought to be zero at the liquid-liquid interface. Recent studies show that the integration of fluid-fluid interactions with fluid-rock interactions is an important step towards a holistic approach to understanding smart water effects. Experiments have shown that the brine solution can alter the micro forces at oil-water interfaces, and these ion-specific interactions lead to oil emulsion formation. The natural emulsifiers present in crude oil behave as polyelectrolytes when the oil interfaces with low salinity water. Wettability alteration caused by low salinity waterflooding during Enhanced Oil Recovery (EOR) process results from the activities of divalent ions. However, polyelectrolytes are said to lose their viscoelastic property with increasing cation concentrations. In this work, the influence of cation concentrations on the dynamics of viscoelastic liquid-liquid interfaces is numerically investigated. The resultant ion concentrations at the crude oil/brine interfaces were estimated using a surface complexation model. Subsequently, the ion concentration parameter is integrated into a mathematical model to describe its effects on the dynamics of a viscoelastic interfacial thin film. The film growth, stability, and rupture were measured after different time steps for three types of fluids (Newtonian, purely elastic and viscoelastic fluids). The interfacial films respond to exposure time in a similar manner with an increasing growth rate, which resulted in the formation of more droplets with time. Increased surfactant accumulation at the interface results in a higher film growth rate which leads to instability and subsequent formation of more satellite droplets. Purely elastic and viscoelastic properties limit film growth rate and consequent film stability compared to the Newtonian fluid. Therefore, low salinity and reduced concentration of the potential determining ions in injection water will lead to improved interfacial viscoelasticity.

Keywords: liquid-liquid interfaces, surfactant concentrations, potential determining ions, residual oil mobilization

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Authors: Afifa Hafidh, Fathi Touati, Ahmed Hichem Hamzaoui, Sayda Somrani

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The objective of the present study has been to synthesize and to characterize silica hybrid materials using sol-gel technic and to investigate their properties. Silica materials were successfully fabricated using various bi-functional 1,3,4-thiadiazoles and tetraethoxysilane (TEOS) as co-precursors via a facile one-pot sol-gel pathway. TEOS was introduced at room temperature with 1,3,4-thiadiazole 2,5-difunctiunal adducts, in ethanol as solvent and using HCl acid as catalyst. The sol-gel process lead to the formation of monolithic, coloured and transparent gels. TEOS was used as a principal network forming agent. The incorporation of 1,3,4-thiadiazole molecules was realized by attachment of these later onto a silica matrix. This allowed covalent linkage between organic and inorganic phases and lead to the formation of Si-N and Si-S bonds. The prepared hybrid materials were characterized by Fourier transform infrared, NMR ²⁹Si and ¹³C, scanning electron microscopy and nitrogen absorption-desorption measurements. The optic and magnetic properties of hybrids are studied respectively by ultra violet-visible spectroscopy and electron paramagnetic resonance. It was shown in this work, that heterocyclic moieties were successfully attached in the hybrid skeleton. The formation of the Si-network composed of cyclic units (Q3 structures) connected by oxygen bridges (Q4 structures) was proved by ²⁹Si NMR spectroscopy. The Brunauer-Elmet-Teller nitrogen adsorption-desorption method shows that all the prepared xerogels have isotherms type IV and are mesoporous solids. The specific surface area and pore volume of these materials are important. The obtained results show that all materials are paramagnetic semiconductors. The data obtained by Nuclear magnetic resonance ²⁹Si and Fourier transform infrared spectroscopy, show that Si-OH and Si-NH groups existing in silica hybrids can participate in adsorption interactions. The obtained materials containing reactive centers could exhibit adsorption properties of metal ions due to the presence of OH and NH functionality in the mesoporous frame work. Our design of a simple method to prepare hybrid materials may give interest of the development of mesoporous hybrid systems and their use within the domain of environment in the future.

Keywords: hybrid materials, sol-gel process, 1, 3, 4-thiadaizole, TEOS

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Authors: Irene Buj-Corral, Ali Bagheri, Alejandro Dominguez-Fernandez

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In recent years, use of ceramic prostheses as an implant in some parts of body has become common. In the present study, research has focused on replacement of the acetabulum bone, which is a part of the pelvis bone. Metallic prostheses have shown some problems such as release of metal ions into patient's blood. In addition, fracture of liners and squeezing between surface of femoral head and inner surface of acetabulum have been reported. Ceramic prostheses have the advantage of low debris and high strength, although they are more difficult to be manufactured than metallic ones. Specifically, new designs try to attempt an acetabulum in which the outer surface will be porous for proliferation of cells and fixation of the prostheses by means of osteointegration, while inner surface must be smooth enough to assure that the movement between femoral head and inner surface will be carried out with on feasibility. In the present study, 3D printing technologies are used for manufacturing ceramic prostheses. In Fused Deposition Modelling (FDM) process, 3D printed plastic prostheses are obtained by means of melting of a plastic filament and subsequent deposition on a glass surface. A similar process is applied to ceramics in which ceramic powders need to be mixed with a liquid polymer before depositing them. After 3D printing, parts are subjected to a sintering process in an oven so that they can achieve final strength. In the present paper, influence of printing parameters on surface roughness 3D printed ceramic parts are presented. Three parameter full factorial design of experiments was used. Selected variables were layer height, infill and nozzle diameter. Responses were average roughness Ra and mean roughness depth Rz. Regression analysis was applied to responses in order to obtain mathematical models for responses. Results showed that surface roughness depends mainly on layer height and nozzle diameter employed, while infill was found not to be significant. In order to get low surface roughness, low layer height and low infill should be selected. As a conclusion, layer height and infill are important parameters for obtaining good surface finish in ceramic 3D printed prostheses. However, use of too low infill could lead to prostheses with low mechanical strength. Such prostheses could not be able to bear the static and dynamic charges to which they are subjected once they are implanted in the body. This issue will be addressed in further research.

Keywords: ceramic, hip prostheses, surface roughness, 3D printing

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Authors: Zakia Hammouni

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Healthcare professionals’ well-being is becoming a priority during this Covid-19 pandemic due to stress, fatigue, and workload. Well before this pandemic, contemporary hospitals are endowed with environmental attributes that contribute to achieving well-being within their environment with the emphasis on the patient. The patient-centered care approach has been followed by the patient-centered design approach. Studies that have focused on the physical environment in hospitals have dealt with the patient's recovery process and his well-being. Prior scientific literature has placed less emphasis on the healthcare professionals’ interactions within the physical environment and to guide hospital designers to make evidence-based design choices to meet the needs and expectations of hospital users by considering, in addition to patients, healthcare professionals. This paper examines these issues related to the daily stress of professionals who provide care in a hospital environment. In this exploratory study, the interest was to grasp the issues related to this environment and explores the current realities of newly built hospitals based on design approaches and what attributes of the physical setting support healthcare professional’s well-being. Within a constructivist approach, this study was conducted in two care units in a new hospital in a big city in Canada before the Covid-19 pandemic (august 2nd to November 2nd 2018). A spatial evaluation of these care units allowed us to understand the interaction of health professionals in their work environment, to understand the spatial behavior of these professionals, and the narratives from 44 interviews of various healthcare professionals. The mental images validated the salient components of the hospital environment as perceived by these healthcare professionals. Thematic analysis and triangulation of the data set were conducted. Among the key attributes promoting the healthcare professionals’ well-being as revealed by the healthcare professionals are the overall light-color atmosphere in the hospital and care unit, particularly in the corridors and public areas of the hospital, the maintenance and cleanliness. The presence of the art elements also brings well-being to the health professionals as well as panoramic views from the staff lounge and corridors of the care units or elevator lobbies. Despite the overall positive assessment of this environment, some attributes need to be improved to ensure the well-being of healthcare professionals and to provide them with a restructuring environment. These are the supply of natural light, softer colors, sufficient furniture, comfortable seating in the restroom, and views, which are important in allowing these healthcare professionals to recover from their work stress. Noise is another attribute that needs to be further improved in the hospital work environment, especially in the nursing workstations and consultant's room. In conclusion, this study highlights the importance of providing healthcare professionals with work and rest areas that allow them to resist the stress they face, particularly during periods of extreme stress and fatigue such as a Covid-19 pandemic.

Keywords: healthcare facilities, healthcare professionals, physical environment, well-being

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Authors: Ashima Sharma, Tapan K. Chaudhuri

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Human Serum Albumin (HSA) is one of the most demanded therapeutic protein with immense biotechnological applications. The current source of HSA is human blood plasma. Blood is a limited and an unsafe source as it possesses the risk of contamination by various blood derived pathogens. This issue led to exploitation of various hosts with the aim to obtain an alternative source for the production of the rHSA. But, till now no host has been proven to be effective commercially for rHSA production because of their respective limitations. Thus, there exists an indispensable need to promote non-animal derived rHSA production. Of all the host systems, Escherichia coli is one of the most convenient hosts which has contributed in the production of more than 30% of the FDA approved recombinant pharmaceuticals. E. coli grows rapidly and its culture reaches high cell density using inexpensive and simple substrates. The fermentation batch turnaround number for E. coli culture is 300 per year, which is far greater than any of the host systems available. Therefore, E. coli derived recombinant products have more economical potential as fermentation processes are cheaper compared to the other expression hosts available. Despite of all the mentioned advantages, E. coli had not been successfully adopted as a host for rHSA production. The major bottleneck in exploiting E. coli as a host for rHSA production was aggregation i.e. majority of the expressed recombinant protein was forming inclusion bodies (more than 90% of the total expressed rHSA) in the E. coli cytosol. Recovery of functional rHSA form inclusion body is not preferred because it is tedious, time consuming, laborious and expensive. Because of this limitation, E. coli host system was neglected for rHSA production for last few decades. Considering the advantages of E. coli as a host, the present work has targeted E. coli as an alternate host for rHSA production through resolving the major issue of inclusion body formation associated with it. In the present study, we have developed a novel and innovative method for enhanced soluble and functional production of rHSA in E.coli (~60% of the total expressed rHSA in the soluble fraction) through modulation of the cellular growth, folding and environmental parameters, thereby leading to significantly improved and enhanced -expression levels as well as the functional and soluble proportion of the total expressed rHSA in the cytosolic fraction of the host. Therefore, in the present case we have filled in the gap in the literature, by exploiting the most well studied host system Escherichia coli which is of low cost, fast growing, scalable and ‘yet neglected’, for the enhancement of functional production of HSA- one of the most crucial biomolecule for clinical and biotechnological applications.

Keywords: enhanced functional production of rHSA in E. coli, recombinant human serum albumin, recombinant protein expression, recombinant protein processing

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Authors: Saad Mohamed Elsaid Onaizah

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One of the reasons for the intensive use of pesticides is to protect agricultural crops and orchards from pests or agricultural worms. The period of time that pesticides stay inside the soil is estimated at about (2) to (12) weeks. Perhaps the most important reason that led to groundwater pollution is the easy leakage of these harmful pesticides from the soil into the aquifers. This research aims to find the best ways to use trated activated charcoal with gold nitrate solution; For the purpose of removing the deadly pesticides from the aqueous solution by adsorption phenomenon. The most used pesticides in Egypt were selected, such as Malathion, Methomyl Abamectin and, Thiamethoxam. Activated charcoal doped with gold ions was prepared by applying chemical and thermal treatments to activated charcoal using gold nitrate solution. Adsorption of studied pesticide onto activated carbon /Au was mainly by chemical adsorption forming complex with the gold metal immobilised on activated carbon surfaces. Also, gold atom was considered as a catalyst to cracking the pesticide molecule. Gold activated charcoal is a low cost material due to the use of very low concentrations of gold nitrate solution. its notice the great ability of activated charcoal in removing selected pesticides due to the presence of the positive charge of the gold ion, in addition to other active groups such as functional oxygen and lignin cellulose. The presence of pores of different sizes on the surface of activated charcoal is the driving force for the good adsorption efficiency for the removal of the pesticides under study The surface area of the prepared char as well as the active groups were determined using infrared spectroscopy and scanning electron microscopy. Some factors affecting the ability of activated charcoal were applied in order to reach the highest adsorption capacity of activated charcoal, such as the weight of the charcoal, the concentration of the pesticide solution, the time of the experiment, and the pH. Experiments showed that the maximum limit revealed by the batch adsorption study for the adsorption of selected insecticides was in contact time (80) minutes at pH (7.70). These promising results were confirmed, and by establishing the practical application of the developed system, the effect of various operating factors with equilibrium, kinetic and thermodynamic studies is evident, using the Langmuir application on the effectiveness of the absorbent material with absorption capacities higher than most other adsorbents.

Keywords: waste water, pesticides pollution, adsorption, activated carbon

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Authors: Raju Chhetri

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Agroforestry is one of the main sources of livelihood among the people of Nepal. In particular, this is the only one mode of livelihood among the Chepangs. The monster earthquake (7.3 MW) that hit the country on the 25th of April in 2015 and many of its aftershocks had devastating effects. As a result, not only the big structures collapsed, it incurred great losses on fabrication, collection centers, schools, markets and other necessary service centers. Although there were a large number of aftershocks after the monster earthquake, the most devastating aftershock took place on 12th May, 2015, which measured 6.3 richter scale. Consequently, it caused more destruction of houses, further calamity to the lives of people, and public life got further perdition. This study was mainly carried out to find out the food security and market situation of Agroforestry product of the Chepang community in Raksirang VDC (one of the severely affected VDCs of Makwanpur district) due to the earthquake. A total of 40 households (12 percent) were randomly selected as a sample in ward number 7 only. Questionnaires and focus groups were used to gather primary data. Additional, two Focus Group Discussions (FGD) were convened in the study area to get some descriptive information on this study. Estimated 370 hectares of land, which was full of Agroforestry plantation, ruptured by the earthquake. It caused severe damages to the households, and a serious loss of food-stock, up to 60-80 percent (maize, millet, and rice). Instead of regular cereal intake, banana (Muas Paradisca) consumption was found ‘high scale’ in the emergency period. The market price of rice (37-44 NRS/Kg) increased by 18.9 percent. Some difference in the income range before and after the earthquake was observed. Before earthquake, sale of Agroforestry, and livestock products were continuing, but after the earthquake, Agroforestry product sale is the only one means of livelihood among Chepangs. Nearly 50-60 percent Agroforestry production of banana (Mass Paradisca), citrus (Citrus Lemon), pineapple (Ananus comosus) and broom grass (Thysanolaena maxima) declined, excepting for cash income from the residual. Heavy demands of Agroforestry product mentioned above lay high farm gate prices (50-100 percent) helps surveyed the community to continue livelihood from its sale. Out of the survey samples, 30 households (75 percent) respondents migrated to safe location due to land rupture, ongoing aftershocks, and landslides. Overall food security situation in this community is acute and challenging for the days to come. Immediate and long term both response from a relief agency concerning food, shelter and safe stocking of Agroforestry product is required to keep secured livelihood in Chepang community.

Keywords: earthquake, rupture, agroforestry, livelihood, indigenous, food security

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Authors: Okpala Charles Chikwendu, Ezeanyim Okechukwu Chiedu, Onukwuli Somto Kenneth

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The demand for lightweight and fuel-efficient automobiles has led to the use of fiber-reinforced polymer composites in place of traditional metal parts. Coir, a natural fiber, offers qualities such as low cost, good tensile strength, and biodegradability, making it a potential filler material for automotive components. However, poor interfacial adhesion between coir and polymeric matrices has been a challenge. To address poor interfacial adhesion with polymeric matrices due to their moisture content and method of preparation, the extracted coir was chemically treated using NaOH. To develop a side view mirror encasement by investigating the mechanical effect of fiber percentage composition, fiber length and percentage composition of Epoxy in a coir fiber reinforced composite, polyester was adopted as the resin for the mold, while that of the product is Epoxy. Coir served as the filler material for the product. Specimens with varied compositions of fiber loading (15, 30 and 45) %, length (10, 15, 20, 30 and 45) mm, and (55, 70, 85) % weight of epoxy resin were fabricated using hand lay-up technique, while those specimens were later subjected to mechanical tests (Tensile, Flexural and Impact test). The results of the mechanical test showed that the optimal solution for the input factors is coir at 45%, epoxy at 54.543%, and 45mm coir length, which was used for the development of a vehicle’s side view mirror encasement. The optimal solutions for the response parameters are 49.333 Mpa for tensile strength, flexural for 57.118 Mpa, impact strength for 34.787 KJ/M2, young modulus for 4.788 GPa, stress for 4.534 KN, and 20.483 mm for strain. The models that were developed using Design Expert software revealed that the input factors can achieve the response parameters in the system with 94% desirability. The study showed that coir is quite durable for filler material in an epoxy composite for automobile applications and that fiber loading and length have a significant effect on the mechanical behavior of coir fiber-reinforced epoxy composites. The coir's low density, considerable tensile strength, and bio-degradability contribute to its eco-friendliness and potential for reducing the environmental hazards of synthetic automotive components.

Keywords: coir, composite, coir fiber, coconut husk, polymer, automobile, mechanical test

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Authors: S. Chuenchooklin, S. Taweepong, U. Pangnakorn

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This research was conducted in the Mae Sot Watershed whereas located in the Moei River Basin at the Upper Salween River Basin in Tak Province, Thailand. The Mae Sot Municipality is the largest urbanized in Tak Province and situated in the midstream of the Mae Sot Watershed. It usually faces flash flood problem after heavy rain due to poor flood management has been reported since economic rapidly bloom up in recently years. Its catchment can be classified as ungauged basin with lack of rainfall data and no any stream gaging station was reported. It was attached by most severely flood event in 2013 as the worst studied case for those all communities in this municipality. Moreover, other problems are also faced in this watershed such shortage water supply for domestic consumption and agriculture utilizations including deterioration of water quality and landslide as well. The research aimed to increase capability building and strengthening the participation of those local community leaders and related agencies to conduct better water management in urban area was started by mean of the data collection and illustration of appropriated application of some short period rainfall forecasting model as the aim for better flood relief plan and management through the hydrologic model system and river analysis system programs. The authors intended to apply the global rainfall data via the integrated data viewer (IDV) program from the Unidata with the aim for rainfall forecasting in short period of 7 - 10 days in advance during rainy season instead of real time record. The IDV product can be present in advance period of rainfall with time step of 3 - 6 hours was introduced to the communities. The result can be used to input to either the hydrologic modeling system model (HEC-HMS) or the soil water assessment tool model (SWAT) for synthesizing flood hydrographs and use for flood forecasting as well. The authors applied the river analysis system model (HEC-RAS) to present flood flow behaviors in the reach of the Mae Sot stream via the downtown of the Mae Sot City as flood extents as water surface level at every cross-sectional profiles of the stream. Both models of HMS and RAS were tested in 2013 with observed rainfall and inflow-outflow data from the Mae Sot Dam. The result of HMS showed fit to the observed data at dam and applied at upstream boundary discharge to RAS in order to simulate flood extents and tested in the field, and the result found satisfied. The result of IDV’s rainfall forecast data was compared to observed data and found fair. However, it is an appropriate tool to use in the ungauged catchment to use with flood hydrograph and river analysis models for future efficient flood relief plan and management.

Keywords: global rainfall, flood forecast, hydrologic modeling system, river analysis system

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Authors: Sina Kazemi, Farshid Torabi, Todd Peterson

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Drilling in shale formations is frequently time-consuming, challenging, and fraught with mechanical failures such as stuck pipes or hole packing off when the cutting removal rate is not sufficient to clean the bottom hole. Crossing the heavy oil shale and sand reservoirs with active shale and microfractures is generally associated with severe fluid losses causing a reduction in the rate of the cuttings removal. These circumstances compromise a well’s integrity and result in a lower rate of penetration (ROP). This study presents collective results of field studies and theoretical analysis conducted on data from South Pars and North Dome in an Iran-Qatar offshore field. Solutions to complications related to drilling in shale formations are proposed through systemically analyzing and applying modeling techniques to select field mud logging data. Field data measurements during actual drilling operations indicate that in a shale formation where the return flow of polymer mud was almost lost in the upper dolomite layer, the performance of hole cleaning and ROP progressively change when higher string rotations are initiated. Likewise, it was observed that this effect minimized the force of rotational torque and improved well integrity in the subsequent casing running. Given similar geologic conditions and drilling operations in reservoirs targeting shale as the producing zone like the Bakken formation within the Williston Basin and Lloydminster, Saskatchewan, a drill bench dynamic modeling simulation was used to simulate borehole cleaning efficiency and mud optimization. The results obtained by altering RPM (string revolution per minute) at the same pump rate and optimized mud properties exhibit a positive correlation with field measurements. The field investigation and developed model in this report show that increasing the speed of string revolution as far as geomechanics and drilling bit conditions permit can minimize the risk of mechanically stuck pipes while reaching a higher than expected ROP in shale formations. Data obtained from modeling and field data analysis, optimized drilling parameters, and hole cleaning procedures are suggested for minimizing the risk of a hole packing off and enhancing well integrity in shale reservoirs. Whereas optimization of ROP at a lower pump rate maintains the wellbore stability, it saves time for the operator while reducing carbon emissions and fatigue of mud motors and power supply engines.

Keywords: ROP, circulating density, drilling parameters, return flow, shale reservoir, well integrity

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Authors: Hsiao-Lin Fang

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The Patient Self-Determination Act is based on the belief that each life is unique. The act regards each patient as an autonomous entity and explicitly protects the patient’s rights to know and make decisions and choices while ensuring that the patient’s wish for a peaceful end is granted. Even when the patient is unconscious and unable to express himself/herself, the patient’s self-determination and its exercise are still protected under the law. The act also ensures that healthcare professionals (HCPs) have a specific set of rules to follow and complete legal protection when their patients are unable to express themselves clearly. This report is about a 55-year-old female patient who weighed 110 kg and was diagnosed with acute type A aortic dissection. The case was that the patient suddenly felt backache and nausea during sleep before daybreak and was therefore transferred to this hospital from the original one. After the doctor explained the patient’s conditions, it was concluded that surgery was necessary. However, the patient’s family was immediately against the surgery after having heard its possible complications. Nevertheless, the patient was still willing to receive the surgery. Being at odds with her family, the patient decided to sign the surgery agreement herself and agreed to receive the two surgical procedures: (1) ascending aorta replacement and (2) innominate artery debranching. After the surgery, the patient did not regain consciousness and therefore received computed tomography scanning of the brain, which revealed false lumen involving proximal left common carotid artery, left subclavian artery and innominate artery, and severe compression of the true lumen with total/subtotal occlusion in the left common carotid artery. On the following day, the doctor discussed two further surgical procedures: (1) endografting for descending aorta and (2) endografting for left common carotid artery and subclavian artery with the family. However, as the patient’s postoperative recovery of consciousness only reached the level of stupor and her family had no intention of subsequent healthcare for the patient, the family made the joint decision three days later to have the endotracheal tube removed from the patient and let her die a natural death. Suggestion: An advance directive (AD) can be created beforehand. Once the patient is in a special clinical state (e.g., terminal illness, permanent vegetative state, etc.), the AD can determine whether to sustain the patient’s life through ‘medical intervention’ or to respect the patient’s rights to choose a peaceful end and receive palliative care. Through the expression of self-determination, it is possible to respect the patient’s medical practice autonomy and protect the patient’s dignity and right to a peaceful end, thereby respecting and supporting the patient’s decision. This also allows the three sides: the patient, the family and the medical team to understand the patient’s true wish in the process of advance care planning (ACP) and thereby promote harmony in the HCP-patient relationship.

Keywords: intensive care unit patient, cardiovascular surgery, self-determination, advance directive

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Authors: Marita Pigłowska, Beata Kurc, Paweł Daszkiewicz

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Railway vehicles are divided into two groups: traction (powered) vehicles and wagons. The traction vehicles include locomotives (line and shunting), railcars (sometimes referred to as railbuses), and multiple units (electric and diesel), consisting of several or a dozen carriages. In vehicles with diesel traction, fuel energy (petrol, diesel, or compressed gas) is converted into mechanical energy directly in the internal combustion engine or via electricity. In the latter case, the combustion engine generator produces electricity that is then used to drive the vehicle (diesel-electric drive or electric transmission). In Poland, such a solution dominates both in heavy linear and shunting locomotives. The classic diesel drive is available for the lightest shunting locomotives, railcars, and passenger diesel multiple units. Vehicles with electric traction do not have their own source of energy -they use pantographs to obtain electricity from the traction network. To determine the competitiveness of the hydrogen propulsion system, it is essential to understand how it works. The basic elements of the construction of a railway vehicle drive system that uses hydrogen as a source of traction force are fuel cells, batteries, fuel tanks, traction motors as well as main and auxiliary converters. The compressed hydrogen is stored in tanks usually located on the roof of the vehicle. This resource is supplemented with the use of specialized infrastructure while the vehicle is stationary. Hydrogen is supplied to the fuel cell, where it oxidizes. The effect of this chemical reaction is electricity and water (in two forms -liquid and water vapor). Electricity is stored in batteries (so far, lithium-ion batteries are used). Electricity stored in this way is used to drive traction motors and supply onboard equipment. The current generated by the fuel cell passes through the main converter, whose task is to adjust it to the values required by the consumers, i.e., batteries and the traction motor. The work will attempt to construct a fuel cell with unique electrodes. This research is a trend that connects industry with science. The first goal will be to obtain hydrogen on a large scale in tube furnaces, to thoroughly analyze the obtained structures (IR), and to apply the method in fuel cells. The second goal is to create low-energy energy storage and distribution station for hydrogen and electric vehicles. The scope of the research includes obtaining a carbon variety and obtaining oxide systems on a large scale using a tubular furnace and then supplying vehicles. Acknowledgments: This work is supported by the Polish Ministry of Science and Education, project "The best of the best! 4.0", number 0911/MNSW/4968 – M.P. and grant 0911/SBAD/2102—B.K.

Keywords: railway, hydrogen, fuel cells, hybrid vehicles

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Authors: Ekta, G. K. Darbha

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Nanotechnology offers the potential of simultaneously increasing efficiency as compared to their bulk material as well as reducing harmful environmental impacts of pesticides in field of agriculture. The term nanopesticide covers different pesticides that are cumulative of several surfactants, polymers, metal ions, etc. of nanometer size ranges from 1-1000 nm and exhibit abnormal behavior (high efficacy and high specific surface area) of nanomaterials. Commercial formulations of pesticides used by farmers nowadays cannot be used effectively due to a number of problems associated with them. For example, more than 90% of applied formulations are either lost in the environment or unable to reach the target area required for effective pest control. Around 20−30% of pesticides are lost through emissions. A number of factors (application methods, physicochemical properties of the formulations, and environmental conditions) can influence the extent of loss during application. It is known that among various formulations, polymer-based formulations show the greatest potential due to their greater efficacy, slow release and protection against premature degradation of active ingredient as compared to other commercial formulations. However, the nanoformulations can have a significant effect on the fate of active ingredient as well as may release some new ingredients by reacting with existing soil contaminants. Environmental fate of these newly generated species is still not explored very well which is essential to field scale experiments and hence a lot to be explored in the field of environmental fate, nanotoxicology, transport properties and stability of such formulations. In our preliminary work, we have synthesized polymer based nanoformulation of commercially used weedicide atrazine. Atrazine belongs to triazine class of herbicide, which is used in the effective control of seed germinated dicot weeds and grasses. It functions by binding to the plastoquinone-binding protein in PS-II. Plant death results from starvation and oxidative damage caused by breakdown in electron transport system. The stability of the suspension of nanoformulation containing herbicide has been evaluated by considering different parameters like polydispersity index, particle diameter, zeta-potential under different environmental relevance condition such as pH range 4-10, temperature range from 25°C to 65°C and stability of encapsulation also have been studied for different amount of added polymer. Morphological characterization has been done by using SEM.

Keywords: atrazine, nanoformulation, nanopesticide, nanotoxicology

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Authors: Phillipa Denise Peart

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Black Asian and Minority Ethnic (BAME) people are more at risk of developing mental health disorders because they are more exposed to unfavorable social, economic, and environmental circumstances. These include housing, education, employment, community development, stigma, and discrimination. However, the majority of BAME mental health intervention studies focus on treatment with therapeutically effective drugs and use basic economic methods to evaluate their effectiveness; as a result, little is invested in the economic assessment of psychosocial interventions in BAME mental health. The UK government’s austerity programme and reduced funds for mental health services, has increased the need for the evaluation and assessment of initiatives to focus on value for money. The No Health without Mental Health policy (2011) provides practice guidance to practitioners, but there is little or no mention of the need to provide mental health initiatives targeted at BAME communities that are effective in terms of their impact and the cost-effectiveness. This, therefore, appears to contradict with and is at odds with the wider political discourse, which suggests there should be an increasing focus on health economic evaluation. As a consequence, it could be argued that whilst such policies provide direction to organisations to provide mental health services to the BAME community, by not requesting effective governance, assurance, and evaluation processes, they are merely paying lip service to address these problems and not helping advance knowledge and practice through evidence-based approaches. As a result, BAME communities suffer due to lack of efficient resources that can aid in the recovery process. This research study explores the mental health initiatives targeted at BAME communities, and analyses the techniques used when examining the cost effectiveness of mental health initiatives for BAME mental health communities. Using critical discourse analysis as an approach and method, mental health services will be selected as case studies, and their evaluations will be examined, alongside the political drivers that frame, shape, and direct their work. In doing so, it will analyse what the mental health policies initiatives are, how the initiatives are directed and demonstrate how economic models of evaluation are used in mental health programmes and how the value for money impacts and outcomes are articulated by mental health programme staff. It is anticipated that this study will further our understanding in order to provide adequate mental health resources and will deliver creative, supportive research to ensure evaluation is effective for the government to provide and maintain high quality and efficient mental health initiatives targeted at BAME communities.

Keywords: black, Asian and ethnic minority, economic models, mental health, health policy

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Authors: Hsin-Yueh Chang, Pin-Chen Liao, Jo-Shu Chang, Chun-Yen Chen

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Biofuel has drawn much attention as a potential substitute to fossil fuels. However, biodiesel from waste oil, oil crops or other oil sources can only satisfy partial existing demands for transportation. Due to the feature of being clean, green and viable for mass production, using microalgae as a feedstock for biodiesel is regarded as a possible solution for a low-carbon and sustainable society. In particular, Thraustochytrium sp. BM2, an indigenous heterotrophic microalga, possesses the potential for metabolizing glycerol to produce lipids. Hence, it is being considered as a promising microalgae-based oil source for biodiesel production and other applications. This study was to optimize the culture pH, scale up, assess the feasibility of producing microalgal lipid from crude glycerol and apply operation strategies following optimal results from shake flask system in a 5L stirred-tank fermenter for further enhancing lipid productivities. Cultivation of Thraustochytrium sp. BM2 without pH control resulted in the highest lipid production of 3944 mg/L and biomass production of 4.85 g/L. Next, when initial glycerol and corn steep liquor (CSL) concentration increased five times (50 g and 62.5 g, respectively), the overall lipid productivity could reach 124 mg/L/h. However, when using crude glycerol as a sole carbon source, direct addition of crude glycerol could inhibit culture growth. Therefore, acid and metal salt pretreatment methods were utilized to purify the crude glycerol. Crude glycerol pretreated with acid and CaCl₂ had the greatest overall lipid productivity 131 mg/L/h when used as a carbon source and proved to be a better substitute for pure glycerol as carbon source in Thraustochytrium sp. BM2 cultivation medium. Engineering operation strategies such as fed-batch and semi-batch operation were applied in the cultivation of Thraustochytrium sp. BM2 for the improvement of lipid production. In cultivation of fed-batch operation strategy, harvested biomass 132.60 g and lipid 69.15 g were obtained. Also, lipid yield 0.20 g/g glycerol was same as in batch cultivation, although with poor overall lipid productivity 107 mg/L/h. In cultivation of semi-batch operation strategy, overall lipid productivity could reach 158 mg/L/h due to the shorter cultivation time. Harvested biomass and lipid achieved 232.62 g and 126.61 g respectively. Lipid yield was improved from 0.20 to 0.24 g/g glycerol. Besides, product costs of three kinds of operation strategies were also calculated. The lowest product cost 12.42 $NTD/g lipid was obtained while employing semi-batch operation strategy and reduced 33% in comparison with batch operation strategy.

Keywords: heterotrophic microalga Thrasutochytrium sp. BM2, microalgal lipid, crude glycerol, fermentation strategy, biodiesel

Procedia PDF Downloads 148

Authors: Ezzati Givi M., Hoveizi E., Nezhad Marani N.

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Platinum-based anticancer therapeutics are the most widely used drugs in clinical chemotherapy but have major limitations and various side effects in clinical applications. Gonadotoxicity and sterility is one of the most common complications for cancer survivors, which seem to be drug-specific and dose-related. Therefore, many efforts have been dedicated to discovering a new structure of platinum-based anticancer agents with improved therapeutic index, fewer side effects. In this regard, new Pt(II)-phosphane complexes containing heterocyclic thionate ligands (PCTL) have been synthesized, which show more potent antitumor activities in comparison to cisplatin. Cisplatin, the best leading metal-based antitumor drug in the field, induces testicular toxicity on Leydig and Sertoli cells leading to serious side effects such as azoospermia and infertility. Therefore in the present study, we aimed to investigate the cytotoxicity effect of PCTL on mice TM4 Sertoli cells with particular emphasis on the role of autophagy in comparison to cisplatin. In this study, an MTT assay was performed to evaluate the IC50 of PCTL and to analyze the TM3 Leydig cell's viability. Cells morphology was evaluated via invert microscope and Changing in morphology for nuclei swelling or autophagic vacuoles formation were assessed by DAPI and MDC staining. Testosterone production in the culture medium was measured using an ELISA kit. Finally, the expression of Autophagy-related genes, Atg5, Beclin1 and p62, were analyzed by qPCR. Based on the obtained results by MTT, the IC50 value of PCTL was 50 μM in TM3 cells and cytotoxic effects was in a dose- and time-dependent manner. Cells morphological changes investigated by inverted microscopy, DAPI, and MDC staining which showed the cytotoxic concentrations of PCTL was significantly higher than cisplatin in the treated TM3 Leydig cells. The results of PCR showed a lack of expression of the p62, Atg5 and Beclin1 gene in TM3 cells treated with PCTL in comparison to cisplatin and control groups. It should be noted that the effects of 25 μM PCTL concentration on TM3 cells have been associated with increased testosterone production and secretion, which requires further study to explain the possible causes and involved molecular mechanisms. The results of the study showed that the PCTL had less-lethal effects on TM3 cells in comparison to cisplatin and probably did not induce autophagy in TM3 cells.

Keywords: platinum-based anticancer agents, cisplatin, Leydig TM3 cells, autophagy

Procedia PDF Downloads 128

Authors: S. Gariani, I. Shyha

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Cutting titanium alloys are usually accompanied with low productivity, poor surface quality, short tool life and high machining costs. This is due to the excessive generation of heat at the cutting zone and difficulties in heat dissipation due to relatively low heat conductivity of this metal. The cooling applications in machining processes are crucial as many operations cannot be performed efficiently without cooling. Improving machinability, increasing productivity, enhancing surface integrity and part accuracy are the main advantages of cutting fluids. Conventional fluids such as mineral oil-based, synthetic and semi-synthetic are the most common cutting fluids in the machining industry. Although, these cutting fluids are beneficial in the industries, they pose a great threat to human health and ecosystem. Vegetable oils (VOs) are being investigated as a potential source of environmentally favourable lubricants, due to a combination of biodegradability, good lubricous properties, low toxicity, high flash points, low volatility, high viscosity indices and thermal stability. Fatty acids of vegetable oils are known to provide thick, strong, and durable lubricant films. These strong lubricating films give the vegetable oil base stock a greater capability to absorb pressure and high load carrying capacity. This paper details preliminary experimental results when turning Ti-6Al-4V. The impact of various VO-based cutting fluids, cutting tool materials, working conditions was investigated. The full factorial experimental design was employed involving 24 tests to evaluate the influence of process variables on average surface roughness (Ra), tool wear and chip formation. In general, Ra varied between 0.5 and 1.56 µm and Vasco1000 cutting fluid presented comparable performance with other fluids in terms of surface roughness while uncoated coarse grain WC carbide tool achieved lower flank wear at all cutting speeds. On the other hand, all tools tips were subjected to uniform flank wear during whole cutting trails. Additionally, formed chip thickness ranged between 0.1 and 0.14 mm with a noticeable decrease in chip size when higher cutting speed was used.

Keywords: cutting fluids, turning, Ti-6Al-4V, vegetable oils, working conditions

Procedia PDF Downloads 279

Authors: Hachul Jung, Ahee Kim, Sanghoon Lee, Dahye Kwon, Songwoo Yoon, Jinhee Moon

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We fabricated a wearable patch device including novel patch type flexible dry electrode based on carbon nanofibers (CNFs) and silicone-based elastomer (MED 6215) for real-time ECG monitoring. There are many methods to make flexible conductive polymer by mixing metal or carbon-based nanoparticles. In this study, CNFs are selected for conductive nanoparticles because carbon nanotubes (CNTs) are difficult to disperse uniformly in elastomer compare with CNFs and silver nanowires are relatively high cost and easily oxidized in the air. Wearable patch is composed of 2 parts that dry electrode parts for recording bio signal and sticky patch parts for mounting on the skin. Dry electrode parts were made by vortexer and baking in prepared mold. To optimize electrical performance and diffusion degree of uniformity, we developed unique mixing and baking process. Secondly, sticky patch parts were made by patterning and detaching from smooth surface substrate after spin-coating soft skin adhesive. In this process, attachable and detachable strengths of sticky patch are measured and optimized for them, using a monitoring system. Assembled patch is flexible, stretchable, easily skin mountable and connectable directly with the system. To evaluate the performance of electrical characteristics and ECG (Electrocardiography) recording, wearable patch was tested by changing concentrations of CNFs and thickness of the dry electrode. In these results, the CNF concentration and thickness of dry electrodes were important variables to obtain high-quality ECG signals without incidental distractions. Cytotoxicity test is conducted to prove biocompatibility, and long-term wearing test showed no skin reactions such as itching or erythema. To minimize noises from motion artifacts and line noise, we make the customized wireless, light-weight data acquisition system. Measured ECG Signals from this system are stable and successfully monitored simultaneously. To sum up, we could fully utilize fabricated wearable patch devices for real-time ECG monitoring easily.

Keywords: carbon nanofibers, ECG monitoring, flexible dry electrode, wearable patch

Procedia PDF Downloads 185

Authors: Sudikshya Bhandari, Jonathan K. London

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Barpak in northern Nepal represents a unique identity expressed through the local rituals, values, lifeways and the styles of vernacular architecture. The traditional residential buildings and construction practices adopted by the dominant ethnic groups: Ghales and Gurungs, reflect environmental, social, cultural and economic concerns. However, most of these buildings did not survive the Gorkha earthquake in 2015 that made many residents skeptical about their strength to resist future disasters. This led Barpak residents to prefer modern housing designs primarily for the strength but additionally for convenience and access to earthquake relief funds. Post-earthquake reconstruction has transformed the cohesive community, developed over hundreds of years into a haphazard settlement with the imposition of externally-driven building models. Housing guidelines provided for the community reconstruction and earthquake resilience have been used as a singular template, similar to other communities on different geographical locations. The design and construction of these buildings do not take into account the local, historical, environmental, social, cultural and economic context of Barpak. In addition to the physical transformation of houses and the settlement, the consequences continue to develop challenges to sustainability. This paper identifies the major challenges for environmental sustainability with the construction of new houses in post-earthquake Barpak. Mixed methods such as interviews, focus groups, site observation, and documentation, and analysis of housing and neighborhood design have been used for data collection. The discernible changing situation of this settlement due to the new housing has included reduced climatic adaptation and thermal comfort, increased consumption of agricultural land and water, minimized use of local building materials, and an increase in energy demand. The research has identified that reconstruction housing practices happening in Barpak, while responding to crucial needs for disaster recovery and resilience, are also leading this community towards an unsustainable future. This study has also integrated environmental, social, cultural and economic parameters into an assessment framework that could be used to develop place-based design guidelines in the context of other post-earthquake reconstruction efforts. This framework seeks to minimize the unintended repercussions of unsustainable reconstruction interventions, support the vitality of vernacular architecture and traditional lifeways and respond to context-based needs in coordination with residents.

Keywords: earthquake, environment, reconstruction, sustainability

Procedia PDF Downloads 115

Authors: S. Wesebaum, S. Willeke

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Production companies are faced with an increasingly turbulent business environment, which demands very high production volumes- and delivery date flexibility. If a decoupling by storage stages is not possible (e.g. at a contract manufacturing company) or undesirable from a logistical point of view, load scattering effects the production processes. ‘Load’ characterizes timing and quantity incidence of production orders (e.g. in work content hours) to workstations in the production, which results in specific capacity requirements. Insufficient coordination between load (demand capacity) and capacity supply results in heavy load scattering, which can be described by deviations and uncertainties in the input behavior of a capacity unit. In order to respond to fluctuating loads, companies try to implement consistent and realizable input behavior using the capacity supply available. For example, a uniform and high level of equipment capacity utilization keeps production costs down. In contrast, strong load scattering at workstations leads to performance loss or disproportionately fluctuating WIP, whereby the logistics objectives are affected negatively. Options for reducing load scattering are e.g. shifting the start and end dates of orders, batch splitting and outsourcing of operations or shifting to other workstations. This leads to an adjustment of load to capacity supply, and thus to a reduction of load scattering. If the adaptation of load to capacity cannot be satisfied completely, possibly flexible capacity must be used to ensure that the performance of a workstation does not decrease for a given load. Where the use of flexible capacities normally raises costs, an adjustment of load to capacity supply reduces load scattering and, in consequence, costs. In the literature you mostly find qualitative statements for describing load scattering. Quantitative evaluation methods that describe load mathematically are rare. In this article the authors discuss existing approaches for calculating load scattering and their various disadvantages such as lack of opportunity for normalization. These approaches are the basis for the development of our mathematical quantification approach for describing load scattering that compensates the disadvantages of the current quantification approaches. After presenting our mathematical quantification approach, the method of batch splitting will be described. Batch splitting allows the adaptation of load to capacity to reduce load scattering. After describing the method, it will be explicitly analyzed in the context of the logistic curve theory by Nyhuis using the stretch factor α1 in order to evaluate the impact of the method of batch splitting on load scattering and on logistic curves. The conclusion of this article will be to show how the methods and approaches presented can help companies in a turbulent environment to quantify the occurring work load scattering accurately and apply an efficient method for adjusting work load to capacity supply. In this way, the achievements of the logistical objectives are increased without causing additional costs.

Keywords: batch splitting, production logistics, production planning and control, quantification, load scattering

Procedia PDF Downloads 399

Authors: H. Ishii, S. Araki, H. Yamamoto

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In recent years, the carbon dioxide (CO2) separation technology is required in terms of the reduction of emission of global warming gases and the efficient use of fossil fuels. Since the emission amount of CO2 gas occupies the large part of greenhouse effect gases, it is considered that CO2 have the most influence on global warming. Therefore, we need to establish the CO2 separation technologies with high efficiency at low cost. In this study, we focused on the membrane separation compared with conventional separation technique such as distillation or cryogenic separation. In this study, we prepared carbonate-ceramic dual-phase membranes to separate CO2 at high temperature. As porous ceramic substrate, the (Pr0.9La0.1)2(Ni0.74Cu0.21Ga0.05)O4+σ, La0.6Sr0.4Ti0.3 Fe0.7O3 and Ca0.8Sr0.2Ti0.7Fe0.3O3-α (PLNCG, LSTF and CSTF) were examined. PLNCG, LSTF and CSTF have the perovskite structure. The perovskite structure has high stability and shows ion-conducting doped by another metal ion. PLNCG, LSTF and CSTF have perovskite structure and has high stability and high oxygen ion diffusivity. PLNCG, LSTF and CSTF powders were prepared by a solid-phase process using the appropriate carbonates or oxides. To prepare porous substrates, these powders mixed with carbon black (20 wt%) and a few drops of polyvinyl alcohol (5 wt%) aqueous solution. The powder mixture were packed into stainless steel mold (13 mm) and uniaxially pressed into disk shape under a pressure of 20 MPa for 1 minute. PLNCG, LSTF and CSTF disks were calcined in air for 6 h at 1473, 1573 and 1473 K, respectively. The carbonate mixture (Li2CO3/Na2CO3/K2CO3: 42.5/32.5/25 in mole percent ratio) was placed inside a crucible and heated to 793 K. Porous substrates were infiltrated with the molten carbonate mixture at 793 K. Crystalline structures of the fresh membranes and after the infiltration with the molten carbonate mixtures were determined by X-ray diffraction (XRD) measurement. We confirmed the crystal structure of PLNCG and CSTF slightly changed after infiltration with the molten carbonate mixture. CO2 permeation experiments with PLNCG-carbonate, LSTF-carbonate and CSTF-carbonate membranes were carried out at 773-1173 K. The gas mixture of CO2 (20 mol%) and He was introduced at the flow rate of 50 ml/min to one side of membrane. The permeated CO2 was swept by N2 (50 ml/min). We confirmed the effect of ceramic materials and temperature on the CO2 permeation at high temperature.

Keywords: membrane, perovskite structure, dual-phase, carbonate

Procedia PDF Downloads 367

Authors: Mohammad Afzal Khan, Fatimah Alanazi, Hala Abdalrahman Ahmed, Talal Shamma, Kilian Kelly, Mohammed A. Hammad, Abdullah O. Alawad, Abdullah Mohammed Assiri, Dieter Clemens Broering

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Lung transplantation is a life-saving surgical replacement of diseased lungs in patients with end-stage respiratory malfunctions. Despite the remarkable short-term recovery, long-term lung survival continues to face several significant challenges, including chronic rejection and severe toxic side-effects due to global immunosuppression. Stem cell-based immunotherapy has been recognized as a crucial immunoregulatory regimen in various preclinical and clinical studies. Despite initial therapeutic outcomes, conventional stem cells face key limitations. The Cymerus™ manufacturing facilitates the production of a virtually limitless supply of consistent human induced pluripotent stem cell (iPSC)-derived mesenchymal stem cells, which could play a key role in selective immunosuppression and graft repair during rejection. Here, we demonstrated the impact of iPSC-derived human MSCs on the development of immune-tolerance and long-term graft survival in mouse orthotopic airway allografts. BALB/c→C57BL/6 allografts were reconstituted with iPSC-derived MSCs (2 million/transplant/ at d0), and allografts were examined for regulatory T cells (Tregs), oxygenation, microvascular blood flow, airway epithelium and collagen deposition during rejection. We demonstrated that iPSC-derived MSC treatment leads to significant increase in tissue expression of hTSG-6 protein, followed by an upregulation of mouse Tregs and IL-5, IL-10, IL-15 cytokines, which augments graft microvascular blood flow and oxygenation, and thereby maintained a healthy airway epithelium and prevented the subepithelial deposition of collagen at d90 post-transplantation. Collectively, these data confirmed that iPSC-derived MSC-mediated immunosuppression has potential to establish immune-tolerance and rescue allograft from sustained hypoxic/ischemic phase and subsequently limits long-term airway epithelial injury and collagen progression, which therapeutically warrant a study of Cymerus iPSC-derived MSCs as a potential management option for immunosuppression in transplant recipients.

Keywords: stem cell therapy, immunotolerance, regulatory T cells, hypoxia and ischemia, microvasculature

Procedia PDF Downloads 158

Authors: Muhammad Naveed Babur, Maria Liaqat

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Background & Objective: People with disabilities especially neurological disabilities have many unmet health and rehabilitation needs, face barriers in accessing mainstream health-care services, and consequently have poor health. There are not sufficient epidemiological studies from Pakistan which assess barriers to neurorehabilitation and ways to counter it. Objectives: The objective of the study was to determine the challenges and to evaluate the barriers for neuro-rehabilitation services in developing countries. Methods: This is Exploratory sequential qualitative study based on the Panel discussion forum in International rehabilitation sciences congress and national rehabilitation conference 2017. Panel group discussion has been conducted in February 2017 with a sample size of eight professionals including Rehabilitation medicine Physician, Physical Therapist, Speech Language therapist, Occupational Therapist, Clinical Psychologist and rehabilitation nurse working in multidisciplinary/Interdisciplinary team. A comprehensive audio-videography have been developed, recorded, transcripted and documented. Data was transcribed and thematic analysis along with characteristics was drawn manually. Data verification was done with the help of two separate coders. Results: After extraction of two separate coders following results are emerged. General category themes are disease profile, demographic profile, training and education, research, barriers, governance, global funding, informal care, resources and cultural beliefs and public awareness. Barriers identified at the level are high cost, stigma, lengthy course of recovery. Hospital related barriers are lack of social support and individually tailored goal setting processes. Organizational barriers identified are lack of basic diagnostic facilities, lack of funding and human resources. Recommendations given by panelists were investment in education, capacity building, infrastructure, governance support, strategies to promote communication and realistic goals. Conclusion: It is concluded that neurorehabilitation in developing countries need attention in following categories i.e. disease profile, demographic profile, training and education, research, barriers, governance, global funding, informal care, resources and cultural beliefs and public awareness. This study also revealed barriers at the level of patient, hospital, organization. Recommendations were also given by panelists.

Keywords: disability, neurorehabilitation, telerehabilitation, disability

Procedia PDF Downloads 191

Authors: Osamede Asowata, Christo Pienaar, Johan Bekker

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Photovoltaic (PV) modules may become a trend for future PV systems because of their greater flexibility in distributed system expansion, easier installation due to their nature, and higher system-level energy harnessing capabilities under shaded or PV manufacturing mismatch conditions. This is as compared to the single or multi-string inverters. Novel residential scale PV arrays are commonly connected to the grid by a single DC–AC inverter connected to a series, parallel or series-parallel string of PV panels, or many small DC–AC inverters which connect one or two panels directly to the AC grid. With an increasing worldwide interest in sustainable energy production and use, there is renewed focus on the power electronic converter interface for DC energy sources. Three specific examples of such DC energy sources that will have a role in distributed generation and sustainable energy systems are the photovoltaic (PV) panel, the fuel cell stack, and batteries of various chemistries. A high-efficiency inverter using Metal Oxide Semiconductor Field-Effect Transistors (MOSFETs) for all active switches is presented for a non-isolated photovoltaic and AC-module applications. The proposed configuration features a high efficiency over a wide load range, low ground leakage current and low-output AC-current distortion with no need for split capacitors. The detailed power stage operating principles, pulse width modulation scheme, multilevel bootstrap power supply, and integrated gate drivers for the proposed inverter is described. Experimental results of a hardware prototype, show that not only are MOSFET efficient in the system, it also shows that the ground leakage current issues are alleviated in the proposed inverter and also a 98 % maximum associated driver circuit is achieved. This, in turn, provides the need for a possible photovoltaic panel switching technique. This will help to reduce the effect of cloud movements as well as improve the overall efficiency of the system.

Keywords: grid connected photovoltaic (PV), Matlab efficiency simulation, maximum power point tracking (MPPT), module integrated converters (MICs), multilevel converter, series connected converter

Procedia PDF Downloads 127

Authors: Md. Rashel Sheikh

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The shipbuilding industry in Bangladesh had become a fast-growing industry in recent years when it began to export newly built ships. The various activities of shipbuilding industries in their limited, confined spaces added occupational worker exposures to chemicals, dusts, and metal fumes. The aim of this literature search is to identify the potential sources of occupational health hazards in shipyards and to promote the regulation of appropriate personal protective equipment (PPE) for the workers. In shipyards, occupational workers are involved in various activities, such as the manufacture, repair, maintenance, dismantling of boats and ships, building small ocean-going vessels and ferries. The occupational workers in the shipbuilding industry suffer from a number of hazardous issues, such as asthma, dermatitis, hearing deficits, and musculoskeletal disorders. The use of modern technologies, such as underwater plasma welding, electron beam welding, and friction stir welding and laser cutting and welding, and appropriate PPE (i.e., long-sleeved shirt and long pants, shoes plus socks, safety masks, chemical resistant gloves, eyewear, face shield, and respirators) can help reduce the occupational exposure to environmental hazards created by different activities in the shipyards. However, most shipyards in Bangladesh use traditional methods, e.g., flame cutting and arc, that add hazardous waste and pollutants to the environment in and around the shipyard. The safety and security of occupational workers in the shipyard workplace are very important. It is the primary responsibility of employers to ensure the safety and security of occupational workers in the shipyards. Employers must use advanced technologies and supply adequate and appropriate PPE for the workers. There are a number of accidents and illnesses that happen daily in the shipyard industries in Bangladesh due to the negligence and lack of adequate technologies and appropriate PPE. In addition, there are no specific regulations and implementations available to use the PPE. It is essential to have PPE regulations and strict enforcement for the adoption of PPE in the shipbuilding industries in Bangladesh. Along with the adoption of PPE with regular health examinations, health education to the workers regarding occupational hazards and lifestyle diseases are also important and require reinforcement. Monitoring health and safety hazards in shipyards are essential to enhance worker protection, and ensure worker safety, and mitigate workplace injuries and illnesses.

Keywords: shipbuilding Industries, health education, occupational health hazards, personal protective equipment, shipyard workers, occupational workers, shipyards

Procedia PDF Downloads 165

Authors: Anne Giles

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Humans naturally wish they could forget traumatic experiences. To help prevent future harm, however, the human brain has evolved to retain data about experiences of threat, alarm, or violation. When given compassionate support and assistance with thinking helpfully and realistically about traumatic events, most people can adjust to experiencing hardships, albeit with residual sad, unfortunate memories. Persistent, recurrent, intrusive memories, difficulty sleeping, emotion dysregulation, and avoidance of reminders, however, may be symptoms of Post-traumatic Stress Disorder (PTSD). Brain scans show that PTSD affects brain functioning. We currently have no physical means of restoring the system of brain structures and functions involved with PTSD. Medications may ease some symptoms but not others. However, forms of "talk therapy" with cognitive components have been found by researchers to reduce, even resolve, a broad spectrum of trauma symptoms. Many cultures have taboos against talking about hardships. Individuals may present themselves to mental health care professionals with severe, disabling trauma symptoms but, because of cultural norms, be unable to speak about them. In China, for example, relationship expectations may include the belief, "Bad things happening in the family should stay in the family (jiāchǒu bùkě wàiyán 家丑不可外扬)." The concept of "family (jiā 家)" may include partnerships, close and extended families, communities, companies, and the nation itself. In contrast to many trauma therapies, Cognitive Processing Therapy (CPT) for Post-traumatic Stress Disorder asks its participants to focus not on "what" happened but on "why" they think the trauma(s) occurred. The question "why" activates and exercises cognitive functioning. Brain scans of individuals with PTSD reveal executive functioning portions of the brain inadequately active, with emotion centers overly active. CPT conceptualizes PTSD as a network of cognitive distortions that keep an individual "stuck" in this under-functioning and over-functioning dynamic. Through asking participants forms of the question "why," plus offering a protocol for examining answers and relinquishing unhelpful beliefs, CPT assists individuals in consciously reactivating the cognitive, executive functions of their brains, thus restoring normal functioning and reducing distressing trauma symptoms. The culturally sensitive components of CPT that allow people to "talk about it without talking about it" may offer the possibility for worldwide relief from symptoms of trauma.

Keywords: cognitive processing therapy (CPT), cultural norms, post-traumatic stress disorder (PTSD), trauma recovery

Procedia PDF Downloads 213

Authors: Leonard Simoni, Ilir Alimehmeti, Ervina Shirka, Endri Hasimi, Ndricim Kallashi, Verona Beka, Suerta Kabili, Artan Goda

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Background: Diabetes Mellitus type 2, small vessel calibre, stented length of vessel, complex lesion morphology, and prior bypass surgery have resulted risk factors for In-Stent Restenosis (ISR). However, there are some contradictory results about body mass index (BMI) as a risk factor for ISR. Purpose: We want to identify clinical, lesional and procedural factors that can predict clinical ISR in our patients. Methods: Were enrolled 759 patients who underwent first-time elective PCI with Bare Metal Stents (BMS) from September 2011 to December 2013 in our Department of Cardiology and followed them for at least 1.5 years with a median of 862 days (2 years and 4 months). Only the patients re-admitted with ischemic heart disease underwent control coronary angiography but no routine angiographic control was performed. Patients were categorized in ISR and non-ISR groups and compared between them. Multivariate analysis - Binary Logistic Regression: Forward Conditional Method was used to identify independent predictive risk factors. P was considered statistically significant when <0.05. Results: ISR compared to non-ISR individuals had a significantly lower BMI (25.7±3.3 vs. 26.9±3.7, p=0.004), higher risk anatomy (LM + 3-vessel CAD) (23% vs. 14%, p=0.03), higher number of stents/person used (2.1±1.1 vs. 1.75±0.96, p=0.004), greater length of stents/person used (39.3±21.6 vs. 33.3±18.5, p=0.01), and a lower use of clopidogrel and ASA (together) (95% vs. 99%, p=0.012). They also had a higher, although not statistically significant, prevalence of Diabetes Mellitus (42% vs. 32%, p=0.072) and a greater number of treated vessels (1.36±0.5 vs. 1.26±0.5, p=0.08). In the multivariate analysis, Diabetes Mellitus type 2 and multiple stents used were independent predictors risk factors for In-Stent Restenosis, OR 1.66 [1.03-2.68], p=0.039, and OR 1.44 [1.16-1.78,] p=0.001, respectively. On the other side higher BMI and use of clopidogrel and ASA together resulted protective factors OR 0.88 [0.81-0.95], p=0.001 and OR 0.2 [0.06-0.72] p=0.013, respectively. Conclusion: Diabetes Mellitus and multiple stents are strong predictive risk factors, whereas the use of clopidogrel and ASA together are protective factors for clinical In-Stent Restenosis. Paradoxically High BMI is a protective factor for In-stent Restenosis, probably related to a larger diameter of vessels and consequently a larger diameter of stents implanted in these patients. Further studies are needed to clarify this finding.

Keywords: body mass index, diabetes mellitus, in-stent restenosis, percutaneous coronary intervention

Procedia PDF Downloads 210

Authors: Mo'ath F. Bataineh

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Exercise is highly effective against obesity. Milk contains several components that support exercising and physical performance. However, there is a lack of published studies on the relationship between camel milk and ability to exercise. A pilot study was conducted with the purpose of comparing the impact of milk type (Cow vs Camel) compared with water on physical performance. Seven male obese participants (age: 20.3 ± 1.5 years; BMI: 35.7 ± 2.7 kg/m2; resting heart rate: 92.7 ± 4.7 beats per minute; training frequency: 4.4 ± 0.8 days/week) were recruited for this pilot study. In a randomized counterbalanced crossover design, participants took part in 3 trials that included ingesting 3 different pre workout drinks in a random order. The pre workout drinks were water (W), whole cow milk (CW), and whole camel milk (CM). On each trial day, participants were asked to report to the laboratory after an overnight fasting. Following a 15-minute short recovery period after their arrival to the laboratory, each participant was presented with a 500 ml of the assigned experimental drink and were asked to ingest it in one minute and at least 120 minutes prior to performing the 6-minute walk test. All drinks were presented at room temperature. Trials with different experimental drinks were performed on separate days. Participants were given at least 4 days of washout period between trials. The trial order was randomized to avoid bias due to learning effect. The 6-minute walk test was performed by all participants and immediately at the conclusion of the test, the covered distance in meters and the rating of perceived exertion (RPE) were recorded. All data were analysed using SPSS software (Version 29.0). The repeated measures ANOVA testing of collected data showed a significant main effect for treatment on covered distance in meters, F (2, 8) = 5.794, p=0.028 with a large effect size (partial eta squared (ηp2) =0.592). Also, LSD post hoc pairwise comparison analysis revealed that Camel milk and Cow milk were significantly (p = 0.044 and p = 0.020 respectively) superior to water in improving the covered distance during the test and that Camel milk tended to be better than Cow’s milk. The RPE values were not significantly different between experimental drinks (p>0.05). In conclusion, milk is superior to water as a pre workout drink, and camel milk is comparable to cow’s milk in enhancing ability to support a higher level of performance compared with water, therefore, camel milk could be used to replace cow’s milk as a suitable pre-exercise drink without expecting any negative consequences on physical performance. The fact that these positive results were obtained with obese individuals should encourage using camel milk without the fear of disturbing physical performance in other weight categories.

Keywords: camel milk, cow milk, obesity, physical performance, pre-workout drink

Procedia PDF Downloads 43

Authors: Zhanna Yermekova, Sergey Roslyakov

Abstract:

Solution combustion synthesis (SCS) is the unique method which multiple times has proved itself as an effective and efficient approach for the versatile synthesis of a variety of materials. It has significant advantages such as relatively simple handling process, high rates of product synthesis, mixing of the precursors on a molecular level, and fabrication of the nanoproducts as a result. Nowadays, an overwhelming majority of solution combustion investigations performed through the volume combustion synthesis (VCS) where the entire liquid precursor is heated until the combustion self-initiates throughout the volume. Less amount of the experiments devoted to the steady-state self-propagating mode of SCS. Under the beforementioned regime, the precursor solution is dried until the gel-like media, and later on, the gel substance is locally ignited. In such a case, a combustion wave propagates in a self-sustaining mode as in conventional solid combustion synthesis. Even less attention is given to the impregnated active layer (IAL) mode of solution combustion. An IAL approach to the synthesis is implying that the solution combustion of the precursors should be initiated on the surface of the third chemical or inside the third substance. This work is aiming to emphasize an underestimated role of the impregnated active layer mode of the solution combustion synthesis for the fundamental studies of the combustion mechanisms. It also serves the purpose of popularizing the technical terms and clarifying the difference between them. In order to do so, the solution combustion synthesis of γ-FeNi (PDF#47-1417) alloy has been accomplished within short (seconds) one-step reaction of metal precursors with hexamethylenetetramine (HTMA) fuel. An idea of the special role of the Ni in a process of alloy formation was suggested and confirmed with the particularly organized set of experiments. The first set of experiments were conducted in a conventional steady-state self-propagating mode of SCS. An alloy was synthesized as a single monophasic product. In two other experiments, the synthesis was divided into two independent processes which are possible under the IAL mode of solution combustion. The sequence of the process was changed according to the equations which are describing an Experiment A and B below: Experiment A: Step 1. Fe(NO₃)₃*9H₂O + HMTA = FeO + gas products; Step 2. FeO + Ni(NO₃)₂*6H₂O + HMTA = Ni + FeO + gas products; Experiment B: Step 1. Ni(NO₃)₂*6H₂O + HMTA = Ni + gas products; Step 2. Ni + Fe(NO₃)₃*9H₂O + HMTA = Fe₃Ni₂+ traces (Ni + FeO). Based on the IAL experiment results, one can see that combustion of the Fe(NO₃)₃9H₂O on the surface of the Ni is leading to the alloy formation while presence of the already formed FeO does not affect the Ni(NO₃)₂*6H₂O + HMTA reaction in any way and Ni is the main product of the synthesis.

Keywords: alloy, hexamethylenetetramine, impregnated active layer mode, mechanism, solution combustion synthesis

Procedia PDF Downloads 134

Authors: Narges Shayesteh Moghaddam

Abstract:

Tungsten (W), a refractory metal known for its remarkably high melting temperature, offers tremendous potential for use in challenging environments prevalent in sectors such as space exploration, defense, and nuclear industries. Additive manufacturing, especially the Laser Powder-Bed Fusion (LPBF) technique, emerges as a beneficial method for fabricating tungsten parts. This technique enables the production of intricate components while simultaneously reducing production lead times and associated costs. However, the inherent brittleness of tungsten and its tendency to crack under high-temperature conditions pose significant challenges to the manufacturing process. Our research primarily focuses on the process of rolling tungsten parts in a layer-by-layer manner in LPBF and the subsequent changes in microstructure. Our objective is not only to identify the alterations in the microstructure but also to assess their implications on the physical properties and performance of the fabricated tungsten parts. To examine these aspects, we conducted an extensive series of experiments that included the fabrication of tungsten samples through LPBF and subsequent characterization using advanced materials analysis techniques. These investigations allowed us to scrutinize shifts in various microstructural features, including, but not limited to, grain size and grain boundaries occurring during the rolling process. The results of our study provide crucial insights into how specific factors, such as plastic deformation occurring during the rolling process, influence the microstructural characteristics of the fabricated parts. This information is vital as it provides a foundation for understanding how the parameters of the layer-by-layer rolling process affect the final tungsten parts. Our research significantly broadens the current understanding of microstructural evolution in tungsten parts produced via the layer-by-layer rolling process in LPBF. The insights obtained will play a pivotal role in refining and optimizing manufacturing parameters, thus improving the mechanical properties of tungsten parts and, therefore, enhancing their performance. Furthermore, these findings will contribute to the advancement of manufacturing techniques, facilitating the wider application of tungsten parts in various high-demand sectors. Through these advancements, this research represents a significant step towards harnessing the full potential of tungsten in high-temperature and high-stress applications.

Keywords: additive manufacturing, rolling, tungsten, refractory materials

Procedia PDF Downloads 97