Search results for: initial letter fluency
2973 Characterization of Ethanol-Air Combustion in a Constant Volume Combustion Bomb Under Cellularity Conditions
Authors: M. Reyes, R. Sastre, P. Gabana, F. V. Tinaut
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In this work, an optical characterization of the ethanol-air laminar combustion is presented in order to investigate the origin of the instabilities developed during the combustion, the onset of the cellular structure and the laminar burning velocity. Experimental tests of ethanol-air have been developed in an optical cylindrical constant volume combustion bomb equipped with a Schlieren technique to record the flame development and the flame front surface wrinkling. With this procedure, it is possible to obtain the flame radius and characterize the time when the instabilities are visible through the cell's apparition and the cellular structure development. Ethanol is an aliphatic alcohol with interesting characteristics to be used as a fuel in Internal Combustion Engines and can be biologically synthesized from biomass. Laminar burning velocity is an important parameter used in simulations to obtain the turbulent flame speed, whereas the flame front structure and the instabilities developed during the combustion are important to understand the transition to turbulent combustion and characterize the increment in the flame propagation speed in premixed flames. The cellular structure is spontaneously generated by volume forces, diffusional-thermal and hydrodynamic instabilities. Many authors have studied the combustion of ethanol air and mixtures of ethanol with other fuels. However, there is a lack of works that investigate the instabilities and the development of a cellular structure in ethanol flames, a few works as characterized the ethanol-air combustion instabilities in spherical flames. In the present work, a parametrical study is made by varying the fuel/air equivalence ratio (0.8-1.4), initial pressure (0.15-0.3 MPa) and initial temperature (343-373K), using a design of experiments type I-optimal. In reach mixtures, it is possible to distinguish the cellular structure formed by the hydrodynamic effect and by from the thermo-diffusive. Results show that ethanol-air flames tend to stabilize as the equivalence ratio decreases in lean mixtures and develop a cellular structure with the increment of initial pressure and temperature.Keywords: ethanol, instabilities, premixed combustion, schlieren technique, cellularity
Procedia PDF Downloads 662972 Multi-Template Molecularly Imprinted Polymer: Synthesis, Characterization and Removal of Selected Acidic Pharmaceuticals from Wastewater
Authors: Lawrence Mzukisi Madikizela, Luke Chimuka
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Removal of organics from wastewater offers a better water quality, therefore, the purpose of this work was to investigate the use of molecularly imprinted polymer (MIP) for the elimination of selected organics from water. A multi-template MIP for the adsorption of naproxen, ibuprofen and diclofenac was synthesized using a bulk polymerization method. A MIP was synthesized at 70°C by employing 2-vinylpyridine, ethylene glycol dimethacrylate, toluene and 1,1’-azobis-(cyclohexanecarbonitrile) as functional monomer, cross-linker, porogen and initiator, respectively. Thermogravimetric characterization indicated that the polymer backbone collapses at 250°C and scanning electron microscopy revealed the porous and roughness nature of the MIP after elution of templates. The performance of the MIP in aqueous solutions was evaluated by optimizing several adsorption parameters. The optimized adsorption conditions were 50 mg of MIP, extraction time of 10 min, a sample pH of 4.6 and the initial concentration of 30 mg/L. The imprinting factors obtained for naproxen, ibuprofen and diclofenac were 1.25, 1.42, and 2.01, respectively. The order of selectivity for the MIP was; diclofenac > ibuprofen > naproxen. MIP showed great swelling in water with an initial swelling rate of 2.62 g/(g min). The synthesized MIP proved to be able to adsorb naproxen, ibuprofen and diclofenac from contaminated deionized water, wastewater influent and effluent.Keywords: adsorption, molecularly imprinted polymer, multi template, pharmaceuticals
Procedia PDF Downloads 3032971 A Furaneol-Containing Glass-Ionomer Cement for Enhanced Antibacterial Activity
Authors: Dong Xie, Yuling Xu, Leah Howard
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Secondary caries is found to be one of the main reasons to the restoration failure of dental restoratives. To prevent secondary caries formation, dental restoratives ought to be made antibacterial. In this study, a natural fruit component furaneol was tethered onto polyacid, the formed polyacid was used to formulate the light-curable glass-ionomer cements, and then the effect of this new antibacterial compound on compressive strength (CS) and antibacterial activity of the formed cement was evaluated. Fuji II LC glass powders were used as fillers. Compressive strength (CS) and S. mutans viability were used to evaluate the mechanical strength and antibacterial activity of the formed cement. The experimental cement showed a significant antibacterial activity, accompanying with an initial CS reduction. Increasing the compound loading significantly decreased the S. mutans viability from 5 to 81% and also reduced the initial CS of the formed cements from 4 to 58%. The cement loading with 7% antibacterial polymer showed 168 MPa, 7.8 GPa, 243 MPa, 46 MPa, and 57 MPa in yield strength, modulus, CS, diametral tensile strength and flexural strength, respectively, as compared to 141, 6.9, 236, 42 and 53 for Fuji II LC. The cement also showed an antibacterial function to other bacteria. No human saliva effect was noticed. It is concluded that the experimental cement may potentially be developed to a permanent antibacterial cement.Keywords: antibacterial, dental materials, strength, cell viability
Procedia PDF Downloads 3172970 Compatibility of Copolymer-Based Grinding Aids and Sulfonated Acetone-Formaldehyde Superplasticizer
Authors: Zhang Tailong
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Compatibility between sulfonated acetone-formalehyde superplasticizer (SAF) and copolymer-based grinding aids (GA) were studied by fluidity, Zeta potential, setting time of cement pasts, initial slump and slump flow of concrete and compressive strength of concrete. ESEM, MIP, and XRD were used to investigate the changing of microstructure of interior concrete. The results indicated that GA could noticeably enhance the dispersion ability of SAF. It was found that better fluidity and slump-keeping ability of cement paste were obtained in the case of GA. In addition, GA and SAF together had a certain retardation effect on hydration of cement paste. With increasing of the GA dosage, the dispersion ability and retardation effect of admixture increased. The compressive strength of the sample made with SAF and GA after 28 days was higher than that of the control sample made only with SAF. The initial slump and slump flow of concrete increased by 10.0% and 22.9%, respectively, while 0.09 wt.% GA was used. XRD examination indicated that new products were not found in the case of GA. In addition, more dense arrangement of hydrates and lower porosity of the specimen were observed by ESEM and MIP, which contributed to higher compressive strength.Keywords: copolymer-based grinding aids, superplasiticizer, compatibility, microstructure, cement, concrete
Procedia PDF Downloads 2462969 Extraction of Road Edge Lines from High-Resolution Remote Sensing Images Based on Energy Function and Snake Model
Authors: Zuoji Huang, Haiming Qian, Chunlin Wang, Jinyan Sun, Nan Xu
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In this paper, the strategy to extract double road edge lines from acquired road stripe image was explored. The workflow is as follows: the road stripes are acquired by probabilistic boosting tree algorithm and morphological algorithm immediately, and road centerlines are detected by thinning algorithm, so the initial road edge lines can be acquired along the road centerlines. Then we refine the results with big variation of local curvature of centerlines. Specifically, the energy function of edge line is constructed by gradient feature and spectral information, and Dijkstra algorithm is used to optimize the initial road edge lines. The Snake model is constructed to solve the fracture problem of intersection, and the discrete dynamic programming algorithm is used to solve the model. After that, we could get the final road network. Experiment results show that the strategy proposed in this paper can be used to extract the continuous and smooth road edge lines from high-resolution remote sensing images with an accuracy of 88% in our study area.Keywords: road edge lines extraction, energy function, intersection fracture, Snake model
Procedia PDF Downloads 3382968 Pedagogical Agency: A Basic Capacity to Carry out a Humanizing and Democratic Pedagog
Authors: Priscilla Echeverria
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For us grown up in neoliberal societies, it is not always clear that we have not only incorporated an economic logic into our subjectivities, but a technical reason, an instrumental way of relationship with the environment inspired in a control interest that constantly dehumanizes us as takes away our capacity of action, becoming mere objects or bureaucrats, stripped of our citizen dimension to participate in social and political issues responsibly and creatively. To restore the capacity of action -agency- is urgent in our societies to strengthen better democracies. On this, the formal educational system plays a crucial role, which in turn needs teachers prepared to understand their role as integral educators instead of mere curriculum managers. For this reason, initial teacher formation (ITF) programs must assume the responsibility of helping them to develop an ethical/political/epistemic pedagogical agency to deal with a technical school culture and, in turn, able to relate to their students in democratic ways to help them to develop their agency capacities. By highlighting a perspective of education as the opposite of technocracy and bureaucracy, this talk precisely addresses ITF as a crucial and formative space to restore a perspective of what a critical education can look like, enabling pedagogy students with pedagogical agency capacities to, in turn, allow their future students to develop it. This discussion is part of my doctoral research, "The importance of developing the capacity for ethical-political-epistemic agency in novice teachers during initial teacher formation to contribute to social justice", which I currently develop in the Educational Research program of the University of Lancaster, United Kingdom, as a Conicyt fellow for the 2019 cohort. This presentation specifically offers preliminary results of the analysis of critical incidents as a research methodological tool to analyse the capacity of pedagogical agency deployed by novice teachers in their first pedagogical experiences in the Chilean context.Keywords: initial teacher formation, pedagogical agency, pedagogical interaction, hidden curriculum, critical pedagogy, social justice
Procedia PDF Downloads 1122967 Preparation and Fabrication of Lithium Disilicate Glass Ceramic as Dental Crowns via Hot Pressing Method
Authors: A. Srion, W. Thepsuwan, N. Monmaturapoj
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Two Lithium disilicate (LD) glass ceramics based on SiO2-Li2O-K2O-Al2O3 system were prepared through glass melting method and then fabricated into dental crowns via hot pressing at 850˚C and 900˚C in order to study the effect of the pressing temperatures on theirs phase formation and microstructure. The factor such as heat treatment temperature (as-cast glass, 600˚C and 700˚C) of the glass ceramics used to press was also investigated the effect of an initial microstructure before pressing. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to determine phase formation and microstructure of the samples, respectively. X-ray diffraction result shows that the main crystalline structure was Li2Si2O5 by having Li3PO4, Li0.6Al0.6Si2O6, Li2SiO3, Ca5 (PO4)3F, SiO2 as minor phases. Glass compositions with different heat treatment temperatures exhibited a difference phase formation but have less effect during pressing. Scanning electron microscopy analysis showed microstructure of lath-like of Li2Si2O5 in all glasses. With increasing the initial heat treatment temperature, the longer the lath-like crystals of lithium disilicate were increased especially when using glass heat treatment at 700˚C followed by pressing at 900˚C. This could be suggested that LD1 heat treatment at 700˚C which pressing at 900˚C presented the best formation by hot pressing and compiled microstructure.Keywords: lithium disilicate, hot pressing, dental crown, microstructure
Procedia PDF Downloads 3252966 Preparation and Characterization of Biosorbent from Cactus (Opuntia ficus-indica) cladodes and its Application for Dye Removal from Aqueous Solution
Authors: Manisha Choudhary, Sudarsan Neogi
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Malachite green (MG), an organic basic dye, has been widely used for the dyeing purpose, as well as a fungicide and antiseptic in aquaculture industry to control fish parasites and disease. However, MG has now turned out to be an extremely controversial compound due to its adverse impact on living beings. Due to high toxicity, proper treatment of wastewater containing MG is utmost important. Among different available technologies, adsorption process is one of the most efficient and cost-effective treatment method due to its simplicity of design, ease of operation and regeneration of used materials. Nonetheless, commercial activated carbon is expensive leading the researchers to focus on utilizing natural resources. In the present work, a species of cactus, Opuntia ficus-indica (OFI), was used to develop a highly efficient, low-cost powdered activated carbon by chemical activation using NaOH. The biosorbent was characterized by Fourier-transform infrared spectroscopy, field emission scanning electron microscope, energy-dispersive X-ray spectroscopy, Brunauer–Emmett–Teller (BET) and X-ray diffraction analysis. Batch adsorption studies were performed to remove MG from an aqueous solution as a function of contact time, initial solution pH, initial dye concentration, biosorbent dosages, the presence of salt and temperature. By increasing the initial dye concentration from 100 to 500 mg/l, adsorption capacity increased from 165.45 to 831.58 mg/g. The adsorption kinetics followed the pseudo-second-order model and the chemisorption mechanisms were revealed. The electrostatic attractions and chemical interactions were observed between amino and hydroxyl groups of the biosorbent and amine groups of the dye. The adsorption was solely controlled by film diffusion. Different isotherm models were used to fit the adsorption data. The excellent recovery of adsorption efficiency after the regeneration of biosorbent indicated the high potential of this adsorbent to remove MG from aqueous solution and an excellent cost-effective biosorbent for wide application in wastewater treatment.Keywords: adsorption, biosorbent, cactus, malachite green
Procedia PDF Downloads 3742965 The Effect of Mist Cooling on Sexual Behavior and Semen Quality of Sahiwal Bulls
Authors: Khalid Ahmed Elrabie Abdelrasoul
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The present study was carried out on Sahiwal cattle bulls maintained at the Artificial Breeding Complex, NDRI, Karnal, Hayana, India, to assess the effect of cooling using mist cooling and fanning on Sahiwal bulls in the dry hot summer season. Fourteen Sahiwal bulls were divided into two groups of seven each. Sexual behavior and semen quality traits considered were: Reaction time (RT), Dismounting time (DMT), Total time taken in mounts (TTTM), Flehmen response (FR), Erection Score (ES), Protrusion Score (PS), Intensity of thrust (ITS), Temperament Score (TS), Libido Score (LS), Semen volume, Physical appearance, Mass activity, Initial progressive motility, Non-eosinophilic spermatozoa count (NESC) and post thaw motility percent. Data were analyzed by least squares technique. Group-1 was the control, whereas group-2 (treatment group) bulls were exposed to mist cooling and fanning (thrice a day 15 min each) in the dry hot summer season. Group-2 showed significantly (p < 0.01) higher value in DMT (sec), ES, PS, ITS, LS, semen volume (ml), semen color density, mass activity, initial motility, progressive motility and live sperm.Keywords: mist cooling, Sahiwal bulls, semen quality, sexual behavior
Procedia PDF Downloads 3202964 Desalination via Electrodialysis: A Newly Designed Fixed Bed Reactor Powered by Renewable Energy Source
Authors: Hend Mesbah, Yehia Youssef, Ibrahim Hassan, Shaaban Nosier, Ahmed El-Shazly, Ahmed Helal
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The problem of drinking water shortage is becoming more crucial nowadays as a result of the increased demand due to the population growth and the rise in the standard living. In recent years, desalination using electrodialysis powered by solar energy (PV-ED) is being widely used to help provide treated water and reduce the scarcity in water supply. In the present study, a water desalination laboratory scale ED cell with a fixed bed circulation system was designed, developed, and tested. The effect of three parameters (namely, cell voltage , flowrate, and salt concentration) on the removal percentage of salt ions was studied. The cell voltage was adjusted at 3 , 4 and 6 V. A flow rate of 5, 10, and 20 ml/s and an initial salt concentration of 2000, 5000, and 7000 ppm were investigated. The maximum salt percentage removal obtained was 52.5% at the lowest initial concentration (2000 ppm) and at the highest cell voltage (6 V). There was no significant effect of the flow rate on the removal percentage. A model of PV module has also been developed to calculate the dimensions of a solar cell based on the amount of energy consumed and it was calculated from the Overall ED cell voltage.Keywords: desalination, electrodialysis, solar desalination, photovoltaic electrodialysis
Procedia PDF Downloads 1462963 Addressing Ophthalmic and Vascular Diabetic Complications in South Asians
Authors: Haaris Khan, Farhad Udwadia
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South Asians are the fastest-growing immigrant population in Canada and are 3-4 times more likely to develop diabetes. In a primary care setting, language barriers continue to persist as a prominent obstacle when delivering crucial health information. Given the abundance of languages in the South Asian community and the varying levels of English fluency, there is compelling evidence that these language barriers can adversely impact health outcomes. The microvascular and macrovascular complications of poor diabetic management are well established and universally recognized. However, these are often difficult concepts to grasp for even individuals fluent in English. In order to lessen the burden of language barriers, we developed a comprehensive guide in various languages that discuss the complications and screening guidelines for diabetic and prediabetic patients. The guide is presented in the form of a pamphlet, with an electronic version being constructed as well, that provides basic information on diabetic retinopathy, neuropathy and nephropathy as well as the screening recommendations. We also conducted a review of the literature around the topic and incorporated our findings into our project. Our goal is for primary care physicians to have this resource and to be able to provide the link or pamphlet to patients in need. Our presentation also provides a comprehensive overview of some of the other barriers that individuals in the South Asian community face when seeking care. Given the staggering number of individuals in the South Asian community with diabetes and the morbidity and mortality associated with diabetes and its complications, effective community-specific strategies are needed to mitigate the potential consequences of poor diabetes management.Keywords: diabetes, patient education, ophthalmology, vascular surgery
Procedia PDF Downloads 2072962 The Data-Driven Localized Wave Solution of the Fokas-Lenells Equation using PINN
Authors: Gautam Kumar Saharia, Sagardeep Talukdar, Riki Dutta, Sudipta Nandy
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The physics informed neural network (PINN) method opens up an approach for numerically solving nonlinear partial differential equations leveraging fast calculating speed and high precession of modern computing systems. We construct the PINN based on strong universal approximation theorem and apply the initial-boundary value data and residual collocation points to weekly impose initial and boundary condition to the neural network and choose the optimization algorithms adaptive moment estimation (ADAM) and Limited-memory Broyden-Fletcher-Golfard-Shanno (L-BFGS) algorithm to optimize learnable parameter of the neural network. Next, we improve the PINN with a weighted loss function to obtain both the bright and dark soliton solutions of Fokas-Lenells equation (FLE). We find the proposed scheme of adjustable weight coefficients into PINN has a better convergence rate and generalizability than the basic PINN algorithm. We believe that the PINN approach to solve the partial differential equation appearing in nonlinear optics would be useful to study various optical phenomena.Keywords: deep learning, optical Soliton, neural network, partial differential equation
Procedia PDF Downloads 1262961 Hash Based Block Matching for Digital Evidence Image Files from Forensic Software Tools
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Internet use, intelligent communication tools, and social media have all become an integral part of our daily life as a result of rapid developments in information technology. However, this widespread use increases crimes committed in the digital environment. Therefore, digital forensics, dealing with various crimes committed in digital environment, has become an important research topic. It is in the research scope of digital forensics to investigate digital evidences such as computer, cell phone, hard disk, DVD, etc. and to report whether it contains any crime related elements. There are many software and hardware tools developed for use in the digital evidence acquisition process. Today, the most widely used digital evidence investigation tools are based on the principle of finding all the data taken place in digital evidence that is matched with specified criteria and presenting it to the investigator (e.g. text files, files starting with letter A, etc.). Then, digital forensics experts carry out data analysis to figure out whether these data are related to a potential crime. Examination of a 1 TB hard disk may take hours or even days, depending on the expertise and experience of the examiner. In addition, it depends on examiner’s experience, and may change overall result involving in different cases overlooked. In this study, a hash-based matching and digital evidence evaluation method is proposed, and it is aimed to automatically classify the evidence containing criminal elements, thereby shortening the time of the digital evidence examination process and preventing human errors.Keywords: block matching, digital evidence, hash list, evaluation of digital evidence
Procedia PDF Downloads 2552960 Epididymis in the Agouti (Dasyprocta azarae): Light Microscope Study
Authors: Bruno C. Schimming, Leandro L. Martins, PatríCia F. F. Pinheiro, Raquel F. Domeniconi, FabríCio S. Oliveira
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The agouti is a wildlife rodent that can be used as an alternative source of animal protein and this species has been raised in captivity in Brazil with the aim of providing meat. Thus, the knowledge of their reproductive biology and morphology of the reproductive organs is important. The objective of this study was to describe the morphology of epididymis in the Azara’s agouti, by light microscopy. Samples of epididymis were obtained from five adult Azara’s agouti (Dasyprocta azarae) during castration surgery performed at the Municipal Zoo of Catanduva, Brazil. Fragments of the epididymal regions (initial segment, caput, corpus and cauda) were collected. The biological samples were immediately fixed in paraformaldehyde for 24 hours, followed by histologic procedures comprising embedding in ParaplastTM (Sigma, St. Louis, MO, USA), sections of 5 µm, and staining with HE and Masson’s trichrome. The epididymis was a highly convoluted tubule that links the testis to the vas deferens. The epithelium lining was pseudostratified columnar surrounded by a periductal stroma. The epithelium contains several cell types: principal, basal, apical, clear, and hallo cells. Principal cells were the most abundant cell type. There were observed also migratory cells named halo cells. The caput epididymis was divided into two different regions: initial segment and caput. The initial segment has a very wide lumen, a high epithelium with conspicuous microvilli and the lumen was wide with exfoliated material. The other region of the caput epididymis, showed a lower epithelium when compared with the initial segment, large amounts of spermatozoa in the lumen, and a cytoplasmic vacuolization. This region presented many narrows cells. Many spermatozoa appeared in the lumen of corpus epididymis. The cauda region had a lower epithelium than the other epididymal regions in the agouti. The cauda epithelium presented plicae protruding into the lumen. Large amounts of spermatozoa are also present in the lumen. Small microvilli uniformly arranged so as to form a kind of “brush border” are observed on the apical surface of the cauda epithelium. The pattern of the epithelium lining the duct of the agouti epididymis does not differ greatly from that reported to other mammals, such as domestic and wildlife animals. These findings can cooperate with future investigations especially those related to rational exploration of these animals. All experimental procedures were approved by the institutional ethics committee (CEUA 796/2015). This study was supported by FAPESP (Grants 2015/23822-1).Keywords: wildlife, testis excurrent ducts, epididymis, morphology
Procedia PDF Downloads 2362959 Computational Model of Human Cardiopulmonary System
Authors: Julian Thrash, Douglas Folk, Michael Ciracy, Audrey C. Tseng, Kristen M. Stromsodt, Amber Younggren, Christopher Maciolek
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The cardiopulmonary system is comprised of the heart, lungs, and many dynamic feedback mechanisms that control its function based on a multitude of variables. The next generation of cardiopulmonary medical devices will involve adaptive control and smart pacing techniques. However, testing these smart devices on living systems may be unethical and exceedingly expensive. As a solution, a comprehensive computational model of the cardiopulmonary system was implemented in Simulink. The model contains over 240 state variables and over 100 equations previously described in a series of published articles. Simulink was chosen because of its ease of introducing machine learning elements. Initial results indicate that physiologically correct waveforms of pressures and volumes were obtained in the simulation. With the development of a comprehensive computational model, we hope to pioneer the future of predictive medicine by applying our research towards the initial stages of smart devices. After validation, we will introduce and train reinforcement learning agents using the cardiopulmonary model to assist in adaptive control system design. With our cardiopulmonary model, we will accelerate the design and testing of smart and adaptive medical devices to better serve those with cardiovascular disease.Keywords: adaptive control, cardiopulmonary, computational model, machine learning, predictive medicine
Procedia PDF Downloads 1782958 International Classification of Primary Care as a Reference for Coding the Demand for Care in Primary Health Care
Authors: Souhir Chelly, Chahida Harizi, Aicha Hechaichi, Sihem Aissaoui, Leila Ben Ayed, Maha Bergaoui, Mohamed Kouni Chahed
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Introduction: The International Classification of Primary Care (ICPC) is part of the morbidity classification system. It had 17 chapters, and each is coded by an alphanumeric code: the letter corresponds to the chapter, the number to a paragraph in the chapter. The objective of this study is to show the utility of this classification in the coding of the reasons for demand for care in Primary health care (PHC), its advantages and limits. Methods: This is a cross-sectional descriptive study conducted in 4 PHC in Ariana district. Data on the demand for care during 2 days in the same week were collected. The coding of the information was done according to the CISP. The data was entered and analyzed by the EPI Info 7 software. Results: A total of 523 demands for care were investigated. The patients who came for the consultation are predominantly female (62.72%). Most of the consultants are young with an average age of 35 ± 26 years. In the ICPC, there are 7 rubrics: 'infections' is the most common reason with 49.9%, 'other diagnoses' with 40.2%, 'symptoms and complaints' with 5.5%, 'trauma' with 2.1%, 'procedures' with 2.1% and 'neoplasm' with 0.3%. The main advantage of the ICPC is the fact of being a standardized tool. It is very suitable for classification of the reasons for demand for care in PHC according to their specificity, capacity to be used in a computerized medical file of the PHC. Its current limitations are related to the difficulty of classification of some reasons for demand for care. Conclusion: The ICPC has been developed to provide healthcare with a coding reference that takes into account their specificity. The CIM is in its 10th revision; it would gain from revision to revision to be more efficient to be generalized and used by the teams of PHC.Keywords: international classification of primary care, medical file, primary health care, Tunisia
Procedia PDF Downloads 2652957 Preventative Maintenance, Impact on the Optimal Replacement Strategy of Secondhand Products
Authors: Pin-Wei Chiang, Wen-Liang Chang, Ruey-Huei Yeh
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This paper investigates optimal replacement and preventative maintenance policies of secondhand products under a Finite Planning Horizon (FPH). Any consumer wishing to replace their product under FPH would have it undergo minimal repairs. The replacement provided would be required to undergo periodical preventive maintenance done to avoid product failure. Then, a mathematical formula for disbursement cost for products under FPH can be derived. Optimal policies are then obtained to minimize cost. In the first of two segments of the paper, a model for initial product purchase of either new or secondhand products is used. This model is built by analyzing product purchasing price, surplus value of product, as well as the minimal repair cost. The second segment uses a model for replacement products, which are also secondhand products with no limit on usage. This model analyzes the same components as the first as well as expected preventative maintenance cost. Using these two models, a formula for the expected final total cost can be developed. The formula requires four variables (optimal preventive maintenance level, preventive maintenance frequency, replacement timing, age of replacement product) to find minimal cost requirement. Based on analysis of the variables using the expected total final cost model, it was found that the purchasing price and length of ownership were directly related. Also, consumers should choose the secondhand product with the higher usage for replacement. Products with higher initial usage upon acquisition require an earlier replacement schedule. In this case, replacements should be made with a secondhand product with less usage. In addition, preventative maintenance also significantly reduces cost. Consumers that plan to use products for longer periods of time replace their products later. Hence these consumers should choose the secondhand product with lesser initial usage for replacement. Preventative maintenance also creates significant total cost savings in this case. This study provides consumers with a method of calculating both the ideal amount of usage of the products they should purchase as well as the frequency and level of preventative maintenance that should be conducted in order to minimize cost and maintain product function.Keywords: finite planning horizon, second hand product, replacement, preventive maintenance, minimal repair
Procedia PDF Downloads 4732956 Investigating Naming and Connected Speech Impairments in Moroccan AD Patients
Authors: Mounia El Jaouhari, Mira Goral, Samir Diouny
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Introduction: Previous research has indicated that language impairments are recognized as a feature of many neurodegenerative disorders, including non-language-led dementia subtypes such as Alzheimer´s disease (AD). In this preliminary study, the focal aim is to quantify the semantic content of naming and connected speech samples of Moroccan patients diagnosed with AD using two tasks taken from the culturally adapted and validated Moroccan version of the Boston Diagnostic Aphasia Examination. Methods: Five individuals with AD and five neurologically healthy individuals matched for age, gender, and education will participate in the study. Participants with AD will be diagnosed on the basis of the Moroccan version of the Diagnostic and Statistial Manual of Mental Disorders (DSM-4) screening test, the Moroccan version of the Mini Mental State Examination (MMSE) test scores, and neuroimaging analyses. The participants will engage in two tasks taken from the MDAE-SF: 1) Picture description and 2) Naming. Expected findings: Consistent with previous studies conducted on English speaking AD patients, we expect to find significant word production and retrieval impairments in AD patients in all measures. Moreover, we expect to find category fluency impairments that further endorse semantic breakdown accounts. In sum, not only will the findings of the current study shed more light on the locus of word retrieval impairments noted in AD, but also reflect the nature of Arabic morphology. In addition, the error patterns are expected to be similar to those found in previous AD studies in other languages.Keywords: alzheimer's disease, anomia, connected speech, semantic impairments, moroccan arabic
Procedia PDF Downloads 1422955 Enhanced Peroxidase Production by Raoultella Species
Authors: Ayodeji O. Falade, Leonard V. Mabinya, Uchechukwu U. Nwodo, Anthony I. Okoh
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Given the high-utility of peroxidase, its production in large amount is of utmost importance. Over the years, actinomycetes have been the major peroxidase-producing bacteria. Consequently, other classes of bacteria with peroxidase production potentials are underexplored. This study, therefore, sought to enhance peroxidase production by a Raoultella species, a new ligninolytic proteobacteria strain, by determining the optimum culture conditions (initial pH, incubation temperature and agitation speed) for peroxidase production under submerged fermentation using the classical process of one variable at a time and supplementing the fermentation medium with some lignin model and inorganic nitrogen compounds. Subsequently, the time-course assay was carried out under optimized conditions. Then, some agricultural residues were valorized for peroxidase production under solid state fermentation. Peroxidase production was optimal at initial pH 5, incubation temperature of 35 °C and agitation speed of 150 rpm with guaiacol and ammonium chloride as the best inducer and nitrogen supplement respectively. Peroxidase production by the Raoultella species was optimal at 72 h with specific productivity of 16.48 ± 0.89 U mg⁻¹. A simultaneous production of a non-peroxide dependent extracellular enzyme which suggests probable laccase production was observed with specific productivity of 13.63 ± 0.45 U mg⁻¹ while sawdust gave the best peroxidase yield under solid state fermentation. In conclusion, peroxidase production by the Raoultella species was increased by 3.40-fold.Keywords: enzyme production, ligninolytic bacteria, peroxidase, proteobacteria
Procedia PDF Downloads 2712954 Comparison of the Thermal Behavior of Different Crystal Forms of Manganese(II) Oxalate
Authors: B. Donkova, M. Nedyalkova, D. Mehandjiev
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Sparingly soluble manganese oxalate is an appropriate precursor for the preparation of nanosized manganese oxides, which have a wide range of technological application. During the precipitation of manganese oxalate, three crystal forms could be obtained – α-MnC₂O₄.2H₂O (SG C2/c), γ-MnC₂O₄.2H₂O (SG P212121) and orthorhombic MnC₂O₄.3H₂O (SG Pcca). The thermolysis of α-MnC₂O₄.2H₂O has been extensively studied during the years, while the literature data for the other two forms has been quite scarce. The aim of the present communication is to highlight the influence of the initial crystal structure on the decomposition mechanism of these three forms, their magnetic properties, the structure of the anhydrous oxalates, as well as the nature of the obtained oxides. For the characterization of the samples XRD, SEM, DTA, TG, DSC, nitrogen adsorption, and in situ magnetic measurements were used. The dehydration proceeds in one step with α-MnC₂O₄.2H2O and γ-MnC₂O₄.2H₂O, and in three steps with MnC₂O₄.3H2O. The values of dehydration enthalpy are 97, 149 and 132 kJ/mol, respectively, and the last two were reported for the first time, best to our knowledge. The magnetic measurements show that at room temperature all samples are antiferomagnetic, however during the dehydration of α-MnC₂O₄.2H₂O the exchange interaction is preserved, for MnC₂O₄.3H₂O it changes to ferromagnetic above 35°C, and for γ-MnC₂O₄.2H₂O it changes twice from antiferomagnetic to ferromagnetic above 70°C. The experimental results for magnetic properties are in accordance with the computational results obtained with Wien2k code. The difference in the initial crystal structure of the forms used determines different changes in the specific surface area during dehydration and different extent of Mn(II) oxidation during decomposition in the air; both being highest at α-MnC₂O₄.2H₂O. The isothermal decomposition of the different oxalate forms shows that the type and physicochemical properties of the oxides, obtained at the same annealing temperature depend on the precursor used. Based on the results from the non-isothermal and isothermal experiments, and from different methods used for characterization of the sample, a comparison of the nature, mechanism and peculiarities of the thermolysis of the different crystal forms of manganese oxalate was made, which clearly reveals the influence of the initial crystal structure. Acknowledgment: 'Science and Education for Smart Growth', project BG05M2OP001-2.009-0028, COST Action MP1306 'Modern Tools for Spectroscopy on Advanced Materials', and project DCOST-01/18 (Bulgarian Science Fund).Keywords: crystal structure, magnetic properties, manganese oxalate, thermal behavior
Procedia PDF Downloads 1712953 ALEF: An Enhanced Approach to Arabic-English Bilingual Translation
Authors: Abdul Muqsit Abbasi, Ibrahim Chhipa, Asad Anwer, Saad Farooq, Hassan Berry, Sonu Kumar, Sundar Ali, Muhammad Owais Mahmood, Areeb Ur Rehman, Bahram Baloch
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Accurate translation between structurally diverse languages, such as Arabic and English, presents a critical challenge in natural language processing due to significant linguistic and cultural differences. This paper investigates the effectiveness of Facebook’s mBART model, fine-tuned specifically for sequence-tosequence (seq2seq) translation tasks between Arabic and English, and enhanced through advanced refinement techniques. Our approach leverages the Alef Dataset, a meticulously curated parallel corpus spanning various domains to capture the linguistic richness, nuances, and contextual accuracy essential for high-quality translation. We further refine the model’s output using advanced language models such as GPT-3.5 and GPT-4, which improve fluency, coherence, and correct grammatical errors in translated texts. The fine-tuned model demonstrates substantial improvements, achieving a BLEU score of 38.97, METEOR score of 58.11, and TER score of 56.33, surpassing widely used systems such as Google Translate. These results underscore the potential of mBART, combined with refinement strategies, to bridge the translation gap between Arabic and English, providing a reliable, context-aware machine translation solution that is robust across diverse linguistic contexts.Keywords: natural language processing, machine translation, fine-tuning, Arabic-English translation, transformer models, seq2seq translation, translation evaluation metrics, cross-linguistic communication
Procedia PDF Downloads 72952 Case Scenario Simulation concerning Eventual Ship Sourced Oil Spill, Expansion and Response Process in Istanbul Strait
Authors: Cihat Aşan
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Istanbul Strait is a crucial and narrow waterway, not only having a role in linking two continents but also has a crossover mission for the petroleum, which is the biggest energy resource, between its supply and demand sources. Besides its substantial features, sensitivities like around 18 million populations in surroundings, military facilities, ports, oil lay down areas etc. also brings the high risk to use of Istanbul Strait. Based on the statistics of Turkish Ministry of Transportation, Maritime and Communication, although the number of vessel passage in Istanbul Strait is declining, tonnage of hazardous and flammable cargo like oil and chemical transportation is increasing and subsequently the risk of oil pollution, loss of life and property is also rising. Based on the mentioned above; it is crucial to be prepared for the initial and subsequent response to eventual ship sourced oil spill which may cause to block the Strait for an unbearable duration. In this study; preconditioned Istanbul Strait sensitive areas studies has been taken into account and possible oil spill scenario is loaded to PISCES 2 (Potential Incident Simulation Control and Evaluation System) decision support system for the determined specific sea area. Consequences of the simulation like oil expanding process, required number and types of assets to response, had in hand and evaluated.Keywords: Istanbul strait, oil spill, PISCES simulator, initial response
Procedia PDF Downloads 3432951 Optimization of Operational Water Quality Parameters in a Drinking Water Distribution System Using Response Surface Methodology
Authors: Sina Moradi, Christopher W. K. Chow, John Van Leeuwen, David Cook, Mary Drikas, Patrick Hayde, Rose Amal
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Chloramine is commonly used as a disinfectant in drinking water distribution systems (DWDSs), particularly in Australia and the USA. Maintaining a chloramine residual throughout the DWDS is important in ensuring microbiologically safe water is supplied at the customer’s tap. In order to simulate how chloramine behaves when it moves through the distribution system, a water quality network model (WQNM) can be applied. In this work, the WQNM was based on mono-chloramine decomposition reactions, which enabled prediction of mono-chloramine residual at different locations through a DWDS in Australia, using the Bentley commercial hydraulic package (Water GEMS). The accuracy of WQNM predictions is influenced by a number of water quality parameters. Optimization of these parameters in order to obtain the closest results in comparison with actual measured data in a real DWDS would result in both cost reduction as well as reduction in consumption of valuable resources such as energy and materials. In this work, the optimum operating conditions of water quality parameters (i.e. temperature, pH, and initial mono-chloramine concentration) to maximize the accuracy of mono-chloramine residual predictions for two water supply scenarios in an entire network were determined using response surface methodology (RSM). To obtain feasible and economical water quality parameters for highest model predictability, Design Expert 8.0 software (Stat-Ease, Inc.) was applied to conduct the optimization of three independent water quality parameters. High and low levels of the water quality parameters were considered, inevitably, as explicit constraints, in order to avoid extrapolation. The independent variables were pH, temperature and initial mono-chloramine concentration. The lower and upper limits of each variable for two water supply scenarios were defined and the experimental levels for each variable were selected based on the actual conditions in studied DWDS. It was found that at pH of 7.75, temperature of 34.16 ºC, and initial mono-chloramine concentration of 3.89 (mg/L) during peak water supply patterns, root mean square error (RMSE) of WQNM for the whole network would be minimized to 0.189, and the optimum conditions for averaged water supply occurred at pH of 7.71, temperature of 18.12 ºC, and initial mono-chloramine concentration of 4.60 (mg/L). The proposed methodology to predict mono-chloramine residual can have a great potential for water treatment plant operators in accurately estimating the mono-chloramine residual through a water distribution network. Additional studies from other water distribution systems are warranted to confirm the applicability of the proposed methodology for other water samples.Keywords: chloramine decay, modelling, response surface methodology, water quality parameters
Procedia PDF Downloads 2242950 Cognitive Impairment in Chronic Renal Patients on Hemodialysis
Authors: Fabiana Souza Orlandi, Juliana Gomes Duarte, Gabriela Dutra Gesualdo
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Chronic renal disease (CKD), accompanied by hemodialysis, causes chronic renal failure in a number of situations that compromises not only physical, personal and environmental aspects, but also psychological, social and family aspects. Objective: To verify the level of cognitive impairment of chronic renal patients on hemodialysis. Methodology: This is a descriptive, cross-sectional study. The present study was performed in a Dialysis Center of a city in the interior of the State of São Paulo. The inclusion criteria were: being 18 years or older; have a medical diagnosis of CKD; being in hemodialysis treatment in this unit; and agree to participate in the research, with the signature of the Informed Consent (TCLE). A total of 115 participants were evaluated through the Participant Characterization Instrument and the Addenbrooke Cognitive Exam - Revised Version (ACE-R), being scored from 0 to 100, stipulating the cut-off note for the complete battery <78 and subdivided into five domains: attention and guidance; memory; fluency; language; (66.9%) and caucasian (54.7%), 53.7 (±14.8) years old. Most of the participants were retired (74.7%), with incomplete elementary schooling (36.5%) and the average time of treatment was 46 months. Most of the participants (61.3%) presented impairment in the area of attention and orientation, 80.4% in the spatial visual domain. Regarding the total ACE-R score, 75.7% of the participants presented scores below the established cut grade. Conclusion: There was a high percentage (75.7%) below the cut-off score established for ACE-R, suggesting that there may be some cognitive impairment among these participants, since the instrument only performs a screening on cognitive health. The results of the study are extremely important so that possible interventions can be traced in order to minimize impairment, thus improving the quality of life of chronic renal patients.Keywords: cognition, chronic renal insufficiency, adult health, dialysis
Procedia PDF Downloads 3652949 Investigating Teachers’ Approaches in Teaching English and Students’ Communicative Ability in a Tertiary College
Authors: Adel Ben Mohamed
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The widespread use of the English language around the world has pushed many countries to consider such a language as a top priority in their educational system. One of these countries is the Sultanate of Oman. In this frame, the Omani government has allocated huge budgets as well as resources in order to implement the English language in its education system. The importance of English is prevalent in Oman. This is clearly noticeable through remarkable signs. For instance, most of the official documents in Oman are in both Arabic (the mother tongue) or English. In addition to that, there is a mushroom of English language institutes all over the country. In 2020, there are over fourteen English language institutes and centers in Oman (esl base, 2020). Moreover, these days most of the Omani parents are sending their children for tuition to learn the English language. Hence, it is apparent that the Sultanate of Oman is giving a great value to the importance of English in attaining various goals. However, in the world of work, what is more, important today is fluency rather than accuracy. Therefore, many people go for communication English rather than technical English. For example, Oman Daily Observer newspaper published a job advertisement of a sale assistant on 23rd of November 2020, recommended that speaking very well English is a must to be hired for the position (Oman Observer, 2020). In line with this and because of the great importance of the English language in Oman, the ministry of higher education has placed much emphasis on this official foreign language. Therefore, in the Omani educational system, all post -secondary students must sit for one year in one of the higher education institutions as a General Foundation Programmes (GFP) prior to moving to their respective majors in diploma level. Accordingly, the implementation of any teaching approach is determined by different factors: some are directly linked to teachers while others are related to organizational variables.Keywords: teaching approaches, communicative, ability, investigating
Procedia PDF Downloads 932948 Stable Time Reversed Integration of the Navier-Stokes Equation Using an Adjoint Gradient Method
Authors: Jurriaan Gillissen
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This work is concerned with stabilizing the numerical integration of the Navier-Stokes equation (NSE), backwards in time. Applications involve the detection of sources of, e.g., sound, heat, and pollutants. Stable reverse numerical integration of parabolic differential equations is also relevant for image de-blurring. While the literature addresses the reverse integration problem of the advection-diffusion equation, the problem of numerical reverse integration of the NSE has, to our knowledge, not yet been addressed. Owing to the presence of viscosity, the NSE is irreversible, i.e., when going backwards in time, the fluid behaves, as if it had a negative viscosity. As an effect, perturbations from the perfect solution, due to round off errors or discretization errors, grow exponentially in time, and reverse integration of the NSE is inherently unstable, regardless of using an implicit time integration scheme. Consequently, some sort of filtering is required, in order to achieve a stable, numerical, reversed integration. The challenge is to find a filter with a minimal adverse affect on the accuracy of the reversed integration. In the present work, we explore an adjoint gradient method (AGM) to achieve this goal, and we apply this technique to two-dimensional (2D), decaying turbulence. The AGM solves for the initial velocity field u0 at t = 0, that, when integrated forward in time, produces a final velocity field u1 at t = 1, that is as close as is feasibly possible to some specified target field v1. The initial field u0 defines a minimum of a cost-functional J, that measures the distance between u1 and v1. In the minimization procedure, the u0 is updated iteratively along the gradient of J w.r.t. u0, where the gradient is obtained by transporting J backwards in time from t = 1 to t = 0, using the adjoint NSE. The AGM thus effectively replaces the backward integration by multiple forward and backward adjoint integrations. Since the viscosity is negative in the adjoint NSE, each step of the AGM is numerically stable. Nevertheless, when applied to turbulence, the AGM develops instabilities, which limit the backward integration to small times. This is due to the exponential divergence of phase space trajectories in turbulent flow, which produces a multitude of local minima in J, when the integration time is large. As an effect, the AGM may select unphysical, noisy initial conditions. In order to improve this situation, we propose two remedies. First, we replace the integration by a sequence of smaller integrations, i.e., we divide the integration time into segments, where in each segment the target field v1 is taken as the initial field u0 from the previous segment. Second, we add an additional term (regularizer) to J, which is proportional to a high-order Laplacian of u0, and which dampens the gradients of u0. We show that suitable values for the segment size and for the regularizer, allow a stable reverse integration of 2D decaying turbulence, with accurate results for more then O(10) turbulent, integral time scales.Keywords: time reversed integration, parabolic differential equations, adjoint gradient method, two dimensional turbulence
Procedia PDF Downloads 2242947 Effect of the Soil-Foundation Interface Condition in the Determination of the Resistance Domain of Rigid Shallow Foundations
Authors: Nivine Abbas, Sergio Lagomarsino, Serena Cattari
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The resistance domain of a generally loaded rigid shallow foundation is normally represented as an interaction diagram limited by a failure surface in the three dimensional (3D) load space (N, V, M), where N is the vertical centric load component, V is the horizontal load component and M is the bending moment component. Usually, this resistance domain is constructed neglecting the foundation sliding mechanism that take place at the level of soil-foundation interface once the applied horizontal load exceeds the interface frictional resistance of the foundation. This issue is translated in the literature by the fact that the failure limit in the (2D) load space (N, V) is constructed as a parabola having an initial slope, at the center of the coordinate system, that depends, in some works, only of the soil friction angle, and in other works, has an empirical value. However, considering a given geometry of the foundation lying on a given soil type, the initial slope of the failure limit must change, for instance, when varying the roughness of the foundation surface at its interface with the soil. The present study discusses the effect of the soil-foundation interface condition on the construction of the resistance domain, and proposes a correction to be applied to the failure limit in order to overcome this effect.Keywords: soil-foundation interface, sliding mechanism, soil shearing, resistance domain, rigid shallow foundation
Procedia PDF Downloads 4602946 Predictors of Clinical Failure After Endoscopic Lumbar Spine Surgery During the Initial Learning Curve
Authors: Daniel Scherman, Daniel Madani, Shanu Gambhir, Marcus Ling Zhixing, Yingda Li
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Objective: This study aims to identify clinical factors that may predict failed endoscopic lumbar spine surgery to guide surgeons with patient selection during the initial learning curve. Methods: This is an Australasian prospective analysis of the first 105 patients to undergo lumbar endoscopic spine decompression by 3 surgeons. Modified MacNab outcomes, Oswestry Disability Index (ODI) and Visual Analogue Score (VAS) scores were utilized to evaluate clinical outcomes at 6 months postoperatively. Descriptive statistics and Anova t-tests were performed to measure statistically significant (p<0.05) associations between variables using GraphPad Prism v10. Results: Patients undergoing endoscopic lumbar surgery via an interlaminar or transforaminal approach have overall good/excellent modified MacNab outcomes and a significant reduction in post-operative VAS and ODI scores. Regardless of the anatomical location of disc herniations, good/excellent modified MacNab outcomes and significant reductions in VAS and ODI were reported post-operatively; however, not in patients with calcified disc herniations. Patients with central and foraminal stenosis overall reported poor/fair modified MacNab outcomes. However, there were significant reductions in VAS and ODI scores post-operatively. Patients with subarticular stenosis or an associated spondylolisthesis reported good/excellent modified MacNab outcomes and significant reductions in VAS and ODI scores post-operatively. Patients with disc herniation and concurrent degenerative stenosis had generally poor/fair modified MacNab outcomes. Conclusion: The outcomes of endoscopic spine surgery are encouraging, with a low complication and reoperation rate. However, patients with calcified disc herniations, central canal stenosis or a disc herniation with concurrent degenerative stenosis present challenges during the initial learning curve and may benefit from traditional open or other minimally invasive techniques.Keywords: complications, lumbar disc herniation, lumbar endoscopic spine surgery, predictors of failed endoscopic spine surgery
Procedia PDF Downloads 1542945 Modeling the Performance of Natural Sand-Bentonite Barriers after Infiltration with Polar and Non-Polar Hydrocarbon Leachates
Authors: Altayeb Qasem, Mousa Bani Baker, Amani Nawafleh
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The complexity of the sand-bentonite liner barrier system calls for an adequate model that reflects the conditions depending on the barrier materials and the characteristics of the permeates which lead to hydraulic conductivity changes when liners infiltrated with polar, no-polar, miscible and immiscible liquids. This paper is dedicated to developing a model for evaluating the hydraulic conductivity in the form of a simple indicator for the compatibility of the liner versus leachate. Based on two liner compositions (95% sand: 5% bentonite; and 90% sand: 10% bentonite), two pressures (40 kPa and 100 kPa), and three leachates: water, ethanol and biofuel. Two characteristics of the leacahtes were used: viscosity of permeate and its octanol-water partitioning coefficient (Kow). Three characteristics of the liners mixtures were evaluated which had impact on the hydraulic conductivity of the liner system: the initial content of bentonite (%), the free swelling index, and the shrinkage limit of the initial liner’s mixture. Engineers can use this modest tool to predict a potential liner failure in sand-bentonite barriers.Keywords: liner performance, sand-bentonite barriers, viscosity, free swelling index, shrinkage limit, octanol-water partitioning coefficient, hydraulic conductivity, theoretical modeling
Procedia PDF Downloads 4132944 Evaluating the Fire Resistance of Offshore Tubular K-Joints Subjected to Balanced Axial Loads
Authors: Neda Azari Dodaran, Hamid Ahmadi
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Results of 405 finite element (FE) analyses were used in the present research to study the effect of the joint geometry on the ultimate strength and initial stiffness of tubular K-joints subjected to axial loading at fire-induced elevated temperatures. The FE models were validated against the data available from experimental tests. Structural behavior under different temperatures (200ºC, 400ºC, 500ºC, and 700ºC) was investigated and compared to the behavior at ambient temperature (20ºC). A parametric study was conducted to investigate the effect of dimensionless geometrical parameters (β, γ, θ, and τ) on the ultimate strength and initial stiffness. Afterwards, ultimate strength data extracted from the FE analyses were compared with the values calculated from the equations proposed by available design codes in which the ultimate strength of the joint at elevated temperatures is obtained by replacing the yield stress of the steel at ambient temperature with the corresponding value at elevated temperature. It was indicated that this method may not have acceptable accuracy for K-joints under axial loading. Hence, a design formula was developed, through nonlinear regression analyses, to determine the ultimate strength of K-joints subjected to balanced axial loads at elevated temperatures.Keywords: axial loading, elevated temperature, parametric equation, static strength, tubular K-joint
Procedia PDF Downloads 149