Search results for: effective mass fraction
12524 An Investigation on MgAl₂O₄ Based Mould System in Investment Casting Titanium Alloy
Authors: Chen Yuan, Nick Green, Stuart Blackburn
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The investment casting process offers a great freedom of design combined with the economic advantage of near net shape manufacturing. It is widely used for the production of high value precision cast parts in particularly in the aerospace sector. Various combinations of materials have been used to produce the ceramic moulds, but most investment foundries use a silica based binder system in conjunction with fused silica, zircon, and alumino-silicate refractories as both filler and coarse stucco materials. However, in the context of advancing alloy technologies, silica based systems are struggling to keep pace, especially when net-shape casting titanium alloys. Study has shown that the casting of titanium based alloys presents considerable problems, including the extensive interactions between the metal and refractory, and the majority of metal-mould interaction is due to reduction of silica, present as binder and filler phases, by titanium in the molten state. Cleaner, more refractory systems are being devised to accommodate these changes. Although yttria has excellent chemical inertness to titanium alloy, it is not very practical in a production environment combining high material cost, short slurry life, and poor sintering properties. There needs to be a cost effective solution to these issues. With limited options for using pure oxides, in this work, a silica-free magnesia spinel MgAl₂O₄ was used as a primary coat filler and alumina as a binder material to produce facecoat in the investment casting mould. A comparison system was also studied with a fraction of the rare earth oxide Y₂O₃ adding into the filler to increase the inertness. The stability of the MgAl₂O₄/Al₂O₃ and MgAl₂O₄/Y₂O₃/Al₂O₃ slurries was assessed by tests, including pH, viscosity, zeta-potential and plate weight measurement, and mould properties such as friability were also measured. The interaction between the face coat and titanium alloy was studied by both a flash re-melting technique and a centrifugal investment casting method. The interaction products between metal and mould were characterized using x-ray diffraction (XRD), scanning electron microscopy (SEM) and Energy Dispersive X-Ray Spectroscopy (EDS). The depth of the oxygen hardened layer was evaluated by micro hardness measurement. Results reveal that introducing a fraction of Y₂O₃ into magnesia spinel can significantly increase the slurry life and reduce the thickness of hardened layer during centrifugal casting.Keywords: titanium alloy, mould, MgAl₂O₄, Y₂O₃, interaction, investment casting
Procedia PDF Downloads 10312523 Computational Fluid Dynamics (CFD) Modeling of Local with a Hot Temperature in Sahara
Authors: Selma Bouasria, Mahi Abdelkader, Abbès Azzi, Herouz Keltoum
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This paper reports concept was used into the computational fluid dynamics (CFD) code cfx through user-defined functions to assess ventilation efficiency inside (forced-ventilation local). CFX is a simulation tool which uses powerful computer and applied mathematics, to model fluid flow situations for the prediction of heat, mass and momentum transfer and optimal design in various heat transfer and fluid flow processes to evaluate thermal comfort in a room ventilated (highly-glazed). The quality of the solutions obtained from CFD simulations is an effective tool for predicting the behavior and performance indoor thermo-aéraulique comfort.Keywords: ventilation, thermal comfort, CFD, indoor environment, solar air heater
Procedia PDF Downloads 61912522 Effect of Control Lasers Polarization on Absorption Coefficient and Refractive Index of a W-Type 4- Level Cylindrical Quantum Dot in the Presence Of Electromagnetically Induced Transparency (ETI)
Authors: Marziehossadat Moezzi
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In this paper, electromagnetically induced transparency (EIT) is investigated in a cylindrical quantum dot (QD) with a parabolic confinement potential. We study the effect of control lasers polarization on absorption coefficient, refractive index and also on the generation of the double transparency windows in this system. Considering an effective mass method, the time-independent Schrödinger equation is solved to obtain the energy structure of the QD. Also, we study the effect of structural characteristics of the QD on refraction and absorption of the QD in the presence of EIT.Keywords: electromagnetically induced transparency, cylindrical quantum dot, absorption coefficient, refractive index
Procedia PDF Downloads 19212521 Vibration Damping Properties of Electrorheological Materials Based on Chitosan/Perlite Composite
Authors: M. Cabuk, M. Yavuz, T. A. Yesil, H. I. Unal
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Electrorheological (ER) fluids are a class of smart materials exhibiting reversible changes in their rheological and mechanical properties under an applied electric field (E). ER fluids generally are composed of polarisable solid particles dispersed in non-conducting oil. ER fluids are fluids which exhibit. The resistance to motion of the ER fluid can be controlled by adjusting the applied E, due to their fast and reversible changes in their rheological properties presence of E. In this study, a series of chitosan/expanded perlite (CS/EP) composites with different chitosan mass fractions (10%, 20%, and 50%) was used. Characterizations of the composites were carried out by Fourier Transform Infrared (FTIR), X-ray diffraction (XRD) and Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) techniques. Antisedimentation stability and dielectric properties of the composites were also determined. The effects of volume fraction, electric field strength, shear rate, shear stress, and temperature onto ER properties of the CS/EP composite particles dispersed in silicone oil (SO) were investigated in detail. Vibration damping behavior of the CS/EP composites were determined as a function of frequence, storage (Gʹ) and loss (Gʹ ʹ) moduli. It was observed that ER response of the CS/EP/SO ER fluids increased with increasing electric field strength and exhibited the typical shear thinning non-Newtonian viscoelastic behaviors with increasing shear rate. The maximum yield stress was obtained with 1250 Pa under E = 3 kV/mm. Further, the CS/EP/SO ER fluids were observed to sensitive to vibration control by showing reversible viscosity enhancements (Gʹ > Gʹ ʹ). Acknowledgements: The authors thank the TÜBİTAK (214Z199) for the financial support of this work.Keywords: chitosan, electrorheology, perlite, vibration control
Procedia PDF Downloads 23012520 Performances Analysis and Optimization of an Adsorption Solar Cooling System
Authors: Nadia Allouache
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The use of solar energy in cooling systems is an interesting alternative to the increasing demand of energy in the world and more specifically in southern countries where the needs of refrigeration and air conditioning are tremendous. This technique is even more attractive with regards to environmental issues. This study focuses on performances analysis and optimization of solar reactor of an adsorption cooling machine working with activated carbon-methanol pair. The modeling of the adsorption cooling machine requires the resolution of the equation describing the energy and mass transfer in the tubular adsorber that is the most important component of the machine. The results show the poor heat conduction inside the porous medium and the resistance between the metallic wall and the bed engender the important temperature gradient and a great difference between the metallic wall and the bed temperature; this is considered as the essential causes decreasing the performances of the machine. For fixed conditions of functioning, the total desorbed mass presents a maximum for an optimal value of the height of the adsorber; this implies the existence of an optimal dimensioning of the adsorber.Keywords: solar cooling system, performances Analysis, optimization, heat and mass transfer, activated carbon-methanol pair, numerical modeling
Procedia PDF Downloads 43212519 A Comprehensive Evaluation of the Bus Rapid Transit Project from Gazipur to Airport at Dhaka Focusing on Environmental Impacts
Authors: Swapna Begum, Higano Yoshiro
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Dhaka is the capital city of Bangladesh. It is considered as one of the traffic congested cities in the world. The growth of the population of this city is increasing day by day. The land use pattern and the increased socio-economic characteristics increase the motor vehicle ownership of this city. The rapid unplanned urbanization and poor transportation planning have deteriorated the transport environment of this city. Also, the huge travel demand with non-motorized traffics on streets is accounted for enormous traffic congestion in this city. The land transport sector in Dhaka is mainly dependent on road transport comprised of both motorized and non-motorized modes of travel. This improper modal mix and the un-integrated system have resulted in huge traffic congestion in this city. Moreover, this city has no well-organized public transport system and any Mass Transit System to cope with this ever increasing demand. Traffic congestion causes serious air pollution and adverse impact on the economy by deteriorating the accessibility, level of service, safety, comfort and operational efficiency. Therefore, there is an imperative need to introduce a well-organized, properly scheduled mass transit system like (Bus Rapid Transit) BRT minimizing the existing problems.Keywords: air pollution, BRT, mass transit, traffic congestion
Procedia PDF Downloads 39512518 Nonlinear Analysis of Torsionally Loaded Steel Fibred Self-Compacted Concrete Beams Reinforced by GFRP Bars
Authors: Khaled Saad Eldin Mohamed Ragab
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This paper investigates analytically the torsion behavior of steel fibered high strength self compacting concrete beams reinforced by GFRP bars. Nonlinear finite element analysis on 12 beams specimens was achieved by using ANSYS software. The nonlinear finite element analysis program ANSYS is utilized owing to its capabilities to predict either the response of reinforced concrete beams in the post elastic range or the ultimate strength of a reinforced concrete beams produced from steel fiber reinforced self compacting concrete (SFRSCC) and reinforced by GFRP bars. A general description of the finite element method, theoretical modeling of concrete and reinforcement are presented. In order to verify the analytical model used in this research using test results of the experimental data, the finite element analysis were performed. Then, a parametric study of the effect ratio of volume fraction of steel fibers in ordinary strength concrete, the effect ratio of volume fraction of steel fibers in high strength concrete, and the type of reinforcement of stirrups were investigated. A comparison between the experimental results and those predicted by the existing models are presented. Results and conclusions thyat may be useful for designers have been raised and represented.Keywords: nonlinear analysis, torsionally loaded, self compacting concrete, steel fiber reinforced self compacting concrete (SFRSCC), GFRP bars and sheets
Procedia PDF Downloads 44912517 Major Incident Tier System in the Emergency Department: An Approach
Authors: Catherine Bernard, Paul Ransom
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Recent events have prompted emergency planners to re-evaluate their emergency response to major incidents and mass casualties. At the Royal Sussex County Hospital, we have adopted a tiered system comprised of three levels, anticipating an increasing P1, P2 or P3 load. This will aid planning in the golden period between Major Incident ‘Standby,’ and ‘Declared’. Each tier offers step-by-step instructions on appropriate patient movement within and out of the department, as well as suggestions for overflow areas and additional staffing levels. This system can be adapted to individual hospitals and provides concise instructions to be followed in a potentially overwhelming situation.Keywords: disaster planning, emergency preparedness, major incident planning, mass casualty event
Procedia PDF Downloads 36712516 The "Street Less Traveled": Body Image and Its Relationship with Eating Attitudes, Influence of Media and Self-Esteem among College Students
Authors: Aditya Soni, Nimesh Parikh, R. A. Thakrar
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Background: A cross-sectional study looked to focus body image satisfaction, heretofore under investigated arena in our setting. This study additionally examined the relationship of body mass index, influence of media and self-esteem. Our second objective was to assess whether there was any relationship between body image dissatisfaction and gender. Methods: A cross-sectional study using body image satisfaction described in words was undertaken, which also explored relationship with body mass index (BMI), influence of media, self-esteem and other selected co-variables such as socio-demographic details, overall satisfaction in life, and particularly in academic/professional life, current health status using 5-item based Likert scale. Convenience sampling was used to select participants of both genders aged from 17 to 32 on a sample size of 303 participants. Results : The body image satisfaction had significant relationship with Body mass index (P<0.001), eating attitude (P<0.001), influence of media (P<0.001) and self-esteem (P<0.001). Students with low weight had a significantly higher prevalence of body image satisfaction while overweight students had a significantly higher prevalence of dissatisfaction (P<0.001). Females showed more concern about body image as compared to males. Conclusions: Generally, this study reveals that the eating attitude, influence of the media and self-esteem is significantly related to the body image. On an empowering note, this level needs to be saved for overall mental and sound advancement of people. Proactive preventive measures could be started in foundations on identity improvement, acknowledgement of self and individual contrasts while keeping up ideal weight and dynamic life style.Keywords: body image, body mass index, media, self-esteem
Procedia PDF Downloads 56812515 CFD Modeling of Mixing Enhancement in a Pitted Micromixer by High Frequency Ultrasound Waves
Authors: Faezeh Mohammadi, Ebrahim Ebrahimi, Neda Azimi
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Use of ultrasound waves is one of the techniques for increasing the mixing and mass transfer in the microdevices. Ultrasound propagation into liquid medium leads to stimulation of the fluid, creates turbulence and so increases the mixing performance. In this study, CFD modeling of two-phase flow in a pitted micromixer equipped with a piezoelectric with frequency of 1.7 MHz has been studied. CFD modeling of micromixer at different velocity of fluid flow in the absence of ultrasound waves and with ultrasound application has been performed. The hydrodynamic of fluid flow and mixing efficiency for using ultrasound has been compared with the layout of no ultrasound application. The result of CFD modeling shows well agreements with the experimental results. The results showed that the flow pattern inside the micromixer in the absence of ultrasound waves is parallel, while when ultrasound has been applied, it is not parallel. In fact, propagation of ultrasound energy into the fluid flow in the studied micromixer changed the hydrodynamic and the forms of the flow pattern and caused to mixing enhancement. In general, from the CFD modeling results, it can be concluded that the applying ultrasound energy into the liquid medium causes an increase in the turbulences and mixing and consequently, improves the mass transfer rate within the micromixer.Keywords: CFD modeling, ultrasound, mixing, mass transfer
Procedia PDF Downloads 17112514 Limitation of Parallel Flow in Three-Dimensional Elongated Porous Domain Subjected to Cross Heat and Mass Flux
Authors: Najwa Mimouni, Omar Rahli, Rachid Bennacer, Salah Chikh
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In the present work 2D and 3D numerical simulations of double diffusion natural convection in an elongated enclosure filled with a binary fluid saturating a porous medium are carried out. In the formulation of the problem, the Boussinesq approximation is considered and cross Neumann boundary conditions are specified for heat and mass walls conditions. The numerical method is based on the control volume approach with the third order QUICK scheme. Full approximation storage (FAS) with full multigrid (FMG) method is used to solve the problem. For the explored large range of the controlling parameters, we clearly evidenced that the increase in the depth of the cavity i.e. the lateral aspect ratio has an important effect on the flow patterns. The 2D perfect parallel flows obtained for a small lateral aspect ratio are drastically destabilized by increasing the cavity lateral dimension. This yields a 3D fluid motion with a much more complicated flow pattern and the classically studied 2D parallel flows are impossible.Keywords: bifurcation, natural convection, heat and mass transfer, parallel flow, porous media
Procedia PDF Downloads 46312513 Primary Fallopian Tube Carcinoma: A Case Report
Authors: Mary Abigail T. Ty, Mary Jocelyn Yu-Laygo, Jocelyn Z. Mariano
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This is a case of L.S.T., a 61 year old, G6P4 (3124) who presented with a one month history of intermittent, brownish, watery, non foul smelling vaginal discharge. There were no other accompanying symptoms. On rectovaginal examination, a palpable adnexal mass on the left was appreciated, with the lower border measuring 3 cm. The mass was non-tender, had irregular borders and solid areas. On transvaginal sonography, it revealed a left pelvic mass measuring 3 x 4 x 2 cm, with a Sassone score of 9. It had vascularization. The primary consideration was Ovarian Newgrowth, probably malignant in nature. CA-125 results were slightly elevated at 43.2 u/ml (NV: 0-35 u/ml). After intraoperative evaluation, the left fallopian tube was converted into a 9 x 4.5 x 3 cm bulbous cystic mass with solid areas. On cut section, the ampullary portion of the fallopian tube contained necrotic and friable looking tissues. Specimen was sent for frozen section and results revealed adenocarcinoma of the left fallopian tube. Patient subsequently underwent complete surgical staging with unremarkable post-operative course. The Surg Ico pathologic diagnosis was G6P4 (3124) Fallopian tube serous cystadenocarcinoma stage 1. The mean incidence of PFTC is 3.6 per million women yearly. This is associated with a generally low survival rate. The primary diagnosis is very difficult to establish because only 0–10% of patients suffering from PFTC are diagnosed pre-operatively. Symptoms play a very important role in the discovery of this disease, because there will be no presentation to the hospital without symptoms. The most common of which may be vaginal bleeding, abdominal pain, a palpable mass and ascites. A conglomerate of manifestations may be encountered, but not at all times. This is termed hydrops tubae profluens where there is presence of colicky pain with relief from intermittent passage of serosanguinous vaginal discharge. The significance of this report is to emphasize the rarity of the case and how the dilemma in the diagnosis is almost always present despite ancillary procedures.Keywords: fallopian tube carcinoma, prognosis, rare, risk factors
Procedia PDF Downloads 31512512 Synthesis and Characterization of Mass Catalysts Based on Cobalt and Molybdenum
Authors: Nassira Ouslimani
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The electronic structure of transition metals gives them many catalytic possibilities in many types of reactions, particularly cobalt and molybdenum. It is in this context that this study is part of the synthesis and characterization of mass catalysts based on cobalt and molybdenum Co1₋xMoO4 (X=0 and X=0.5 and X=1). The two catalysts were prepared by Co-precipitation using ammonia as a precipitating agent and one by precipitation. The samples obtained were analyzed by numerous physic-chemical analysis techniques: ATG-ATD-DSC, DRX-HT, SEM-EDX, and the elemental composition of the catalysts was verified by SAA as well as the FTIR. The ATG-DSC shows a mass loss for all the catalysts of approximately 8%, corresponding to the loss of water and the decomposition of nitrates. The DRX-HT analysis allows the detection of the two CoMoO4 phases with diffraction peaks which increase with the increase in temperature. The results of the FTIR analysis made it possible to highlight the vibration modes of the bonds of the structure of the prepared catalysts. The SEM images of the solids show very different textures with almost homogeneous surfaces with a more regular particle size distribution and a more defined grain shape. The EDX analysis showed the presence of the elements Co, Mo, and O in proportions very close to the nominal proportions. Finally, the actual composition, evaluated by SAA, is close to the theoretical composition fixed during the preparation. This testifies to the good conditions for the preparation of the catalysts by the co-precipitation method.Keywords: catalytic, molybdenum, coprecipitation, cobalt, ammonia
Procedia PDF Downloads 7912511 Body Mass Components in Young Soccer Players
Authors: Elizabeta Sivevska, Sunchica Petrovska, Vaska Antevska, Lidija Todorovska, Sanja Manchevska, Beti Dejanova, Ivanka Karagjozova, Jasmina Pluncevic Gligoroska
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Introduction: Body composition plays an important role in the selection of young soccer players and it is associated with their successful performance. The most commonly used model of body composition divides the body into two compartments: fat components and fat-free mass (muscular and bone components). The aims of the study were to determine the body composition parameters of young male soccer players and to show the differences in age groups. Material and methods: A sample of 52 young male soccer players, with an age span from 9 to 14 years were divided into two groups according to the age (group 1 aged 9 to 12 years and group 2 aged 12 to 14 years). Anthropometric measurements were taken according to the method of Mateigka. The following measurements were made: body weight, body height, circumferences (arm, forearm, thigh and calf), diameters (elbow, knee, wrist, ankle) and skinfold thickness (biceps, triceps, thigh, leg, chest, abdomen). The measurements were used in Mateigka’s equations. Results: Body mass components were analyzed as absolute values (in kilograms) and as percentage values: the muscular component (MC kg and MC%), the bone component (BCkg and BC%) and the body fat (BFkg and BF%). The group up to 12 years showed the following mean values of the analyzed parameters: MM=21.5kg; MM%=46.3%; BC=8.1kg; BC%=19.1%; BF= 6.3kg; BF%= 15.7%. The second group aged 12-14 year had mean values of body composition parameters as follows: MM=25.6 kg; MM%=48.2%; BC = 11.4 kg; BC%=21.6%; BF= 8.5 kg; BF%= 14. 7%. Conclusions: The young soccer players aged 12 up to 14 years who are in the pre-pubertal phase of growth and development had higher bone component (p<0.05) compared to younger players. There is no significant difference in muscular and fat body component between the two groups of young soccer players.Keywords: body composition, young soccer players, body fat, fat-free mass
Procedia PDF Downloads 44812510 Comprehending the Relationship between the Red Blood Cells of a Protein 4.1 -/- Patient and Those of Healthy Controls: A Comprehensive Analysis of Tandem Mass Spectrometry Data
Authors: Ahmed M. Hjazi, Bader M. Hjazi
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Protein 4.1 is a crucial component of complex interactions between the cytoskeleton and other junctional complex proteins. When the gene encoding this protein is altered, resulting in reduced expression, or when the protein is absent, the red cell undergoes a significant structural change. This research aims to achieve a deeper comprehension of the biochemical effects of red cell protein deficiency. A Tandem Mass Spectrometry Analysis (TMT-MS/MS) of patient cells lacking protein 4.1 compared to three healthy controls was achieved by the Proteomics Institute of the University of Bristol. The SDS-PAGE and Western blotting were utilized on the original patient sample and controls to partially confirm TMT MS/MS data analysis of the protein-4.1-deficient cells. Compared to healthy controls, protein levels in samples lacking protein 4.1 had a significantly higher concentration of proteins that probably originated from reticulocytes. This could occur if the patient has an elevated reticulocyte count. The increase in chaperone and reticulocyte-associated proteins was most notable in this study. This may result from elevated quantities of reticulocytes in patients with hereditary elliptocytosis.Keywords: hereditary elliptocytosis, protein 4.1, red cells, tandem mass spectrometry data.
Procedia PDF Downloads 6912509 Chemical and Biological Examination of De-Oiled Indian Propolis
Authors: Harshada Vaidya-Kannur, Dattatraya Naik
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Propolis, one of the beehive products also referred as bee-glue is sticky dark coloured complex mixture of compounds. The volatile oil can be isolated from the propolis by hydrodistillation. The mark that is left behind after the removal of volatile oil is referred as the de-oiled propolis. Antioxidant as well as anti-inflammatory properties of total ethanolic extract of de-oiled propolis (TEEDP) was investigated. Another lot of deoiled propolis was successively exacted with hexane, ethyl acetate and ethanol. Activities of these fractions were also determined. Antioxidant activity was determined by studying ABTS, DPPH and NO radical scavenging. Determination of anti-inflammatory activity was carried out by topical TPA induced mouse ear oedema model. It is noteworthy that ethyl acetate fraction of deoiled propolis (EAFDP) exhibited 49.45 % TEAC activity at the concentration 0.2 mg/ml which is equivalent to the activity of trolox at the concentration 0.2 mg/ml. Its DPPH scavenging activity (72.56%) was closely comparable to that of trolox (75%). However its NO scavenging activity was comparatively low. From IC50 values it could be concluded that the efficiency of scavenging ABTS radicals by the de-oiled propolis was more pronounced as compared to scavenging of other radicals. Studies by TPA induced mouse ear inflammation model indicated that the de-oiled propolis of Indian origin had significant topical anti-inflammatory activity. The EAFDP was found to be the most active fraction for this activity also. The purification of EAFP yielded six pure crystalline compounds. These compounds were identified by their physical data and spectral data.Keywords: anti-inflammatory activity, anti-oxidant activity, column chromatography, de-oiled propolis
Procedia PDF Downloads 28212508 Triangular Libration Points in the R3bp under Combined Effects of Oblateness, Radiation and Power-Law Profile
Authors: Babatunde James Falaye, Shi Hai Dong, Kayode John Oyewumi
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We study the effects of oblateness up to J4 of the primaries and power-law density profile (PDP) on the linear stability of libration location of an innitesimal mass within the framework of restricted three body problem (R3BP), by using a more realistic model in which a disc with PDP is rotating around the common center of the system mass with perturbed mean motion. The existence and stability of triangular equilibrium points have been explored. It has been shown that triangular equilibrium points are stable for 0 < μ < μc and unstable for μc ≤ μ ≤ 1/2, where c denotes the critical mass parameter. We find that, the oblateness up to J2 of the primaries and the radiation reduces the stability range while the oblateness up to J4 of the primaries increases the size of stability both in the context where PDP is considered and ignored. The PDP has an eect of about ≈0:01 reduction on the application of c to Earth-Moon and Jupiter-Moons systems. We find that the comprehensive effects of the perturbations have a stabilizing proclivity. However, the oblateness up to J2 of the primaries and the radiation of the primaries have tendency for instability, while coecients up to J4 of the primaries have stability predisposition. In the limiting case c = 0, and also by setting appropriate parameter(s) to zero, our results are in excellent agreement with the ones obtained previously. Libration points play a very important role in space mission and as a consequence, our results have a practical application in space dynamics and related areas. The model may be applied to study the navigation and station-keeping operations of spacecraft (innitesimal mass) around the Jupiter (more massive) -Callisto (less massive) system, where PDP accounts for the circumsolar ring of asteroidal dust, which has a cloud of dust permanently in its wake.Keywords: libration points, oblateness, power-law density profile, restricted three-body problem
Procedia PDF Downloads 31612507 Use of PET Fibers for Enhancing the Ductility of Exterior RC Beam-Column Connections Subjected to Reversed Cyclic Loading
Authors: Comingstarful Marthong, Shembiang Marthong
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Application of Polyethylene terephthalate (PET) fiber for enhancing the seismic performance of exterior RC beam-column connections in substitution of steel fibers is experimentally investigated. The study involves the addition of Polyethylene terephthalate (PET) fiber-reinforced concrete, i.e., PFRC at the joint region of the connection. The PET fiber of 0.5% volume fraction used in the PFRC mix is obtained by hand cutting of post-consumer PET bottles. Specimens design as per relevant codes was casted and tested to reverse cyclic loading. PFRC specimen was also casted and subjected to similar loading sequence. Test results established that addition of PET fibers in the joint region is effective in enhancing the displacement ductility and energy dissipation capacity. The improvement of damage indices and principal tensile stresses of PFRC specimens gave experimental evidence of the suitability of PET fibers as a discrete reinforcement in the substitution of steel fiber for structural use.Keywords: beam-column connections, polyethylene terephthalate fibers reinforced concrete, joint region, ductility, seismic capacity
Procedia PDF Downloads 27412506 Exploring Stakeholders’ Perceptions of the Implementation of the Door-to-Door Vaccination Campaign for the Oral Polio Vaccine (NOPV2) In Uganda: A Qualitative Study
Authors: Elizabeth B. Katana, Brenda N. Simbwa, Josephine Namayanja, Bob O. Amodan, Edirisa J. Nsubuga, Eva A. O. Laker
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Background: Understanding stakeholders’ perceptions towards the implementation of a mass vaccination campaign is important to ensure the design of better strategies to address challenges. We explored stakeholders’ perceptions of the implementation of a nationwide door-to-door mass vaccination campaign for the oral polio vaccine (nOPV2) in Uganda for the two rounds that occurred in January and November 2022. Methods: A qualitative study was conducted among stakeholders who participated in the campaign implementation from 8 districts in Uganda using random sampling. We conducted 46 In-depth interviews lasting 30 – 40 minutes with 6 national/central supervisors, 12 district, 14 sub-county, and 14 parish-level supervisors. Stakeholders were asked about their experiences in the campaign implementation, including challenges faced and their opinions of the campaign impact and use of the door-to-door strategy. Data were analyzed thematically in line with the major campaign activities. Results: Most of the stakeholders were primarily concerned about poor planning, inadequate training of vaccination teams, community resistance including schools, challenges with recruitment and teaming of vaccinators, poor and delayed payments, lack of logistics and motivation for vaccination teams, the timing of the activities and implementing amidst COVID-19 and Ebola. The stakeholders believed that the first round was not well planned and implemented, while the second round was leveraged in their previous experiences. On the other hand, some positive experiences were noted with regard to communication, advocacy and mobilization, vaccine delivery and distribution, district readiness assessments, and cold chain management. Conclusion: This study identified many challenges that were faced in the implementation of the door-to-door mass campaign for nOPV2 in Uganda. This study identified that more needs to be done to improve door-to-door mass campaigns with a focus on motivating the implementers. These findings highlight the need for conducting performance reviews, improved planning, especially routine updates and verification of target populations and training in microplanning, and adequate mapping of community resistance to inform the implementation of future mass campaigns.Keywords: mass polio vaccination campaigns, door-to-door strategy, stakeholders' perceptions, implementation challenges
Procedia PDF Downloads 6012505 Mechanism of pH Sensitive Flocculation for Organic Load and Colour Reduction in Landfill Leachate
Authors: Brayan Daniel Riascos Arteaga, Carlos Costa Perez
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Landfill leachate has an important fraction of humic substances, mainly humic acids (HAs), which often represent more than half value of COD, specially in liquids proceeded from composting processes of organic fraction of solid wastes. We propose in this article a new method of pH sensitive flocculation for COD and colour reduction in landfill leachate based on the chemical properties of HAs. Landfill leachate with a high content of humic acids can be efficiently treated by pH sensitive flocculation at pH 2.0, reducing COD value in 86.1% and colour in 84.7%. Mechanism of pH sensitive flocculation is based in protonation first of phenolic groups and later of carboxylic acid groups in the HAs molecules, resulting in a reduction of Zeta potential value. For pH over neutrality, carboxylic acid and phenolic groups are ionized and Zeta potential increases in absolute value, maintaining HAs in suspension as colloids and conducting flocculation to be obstructed. Ionized anionic groups (carboxylates) can interact electrostatically with cations abundant in leachate (site binding) aiding to maintain HAs in suspension. Simulation of this situation and ideal visualization of Zeta potential behavior is described in the paper and aggregation of molecules by H-bonds is proposed as the main step in separation of HAs from leachate and reduction of COD value in this complex liquid. CHNS analysis, FT-IR spectrometry and UV–VIS spectrophotometry show chemical elements content in the range of natural and commercial HAs, clear aromaticity and carboxylic acids and phenolic groups presence in the precipitate from landfill leachateKeywords: landfill leachate, humic acids, COD, chemical treatment, flocculation
Procedia PDF Downloads 6512504 Between an Idea and the Experiment: Dome Houses in Warsaw
Authors: Zaguła Artur, Jaruga-rozdolska Anna
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The idea of prefabricated dwellings dates back to the earliest times; however, it was during the modern era that it became one of the main thoughts that stimulated the imagination of architects. The system of prefabrication invented by Ford had inspired them to try to create a system or prototype that could become the basis for the mass 'production' of houses. The attempts made by Le Corbusier, Buckminster Fuller or Charles and Ray Eames, among others, are well known in this regard. The economic attractiveness of replicable, mass-producible houses meant that experiments in this area were undertaken in both the West and the East. Among such attempts was the project of dome-shaped houses conceived by the architect and inventor Andrzej Iwanicki and realised between 1961 and 1966 in Warsaw's Okęcie district on Ustrzycka Street.Keywords: dome houses, polish modernism, postwar modernism, modernist houses
Procedia PDF Downloads 10212503 Energy Saving Study of Mass Rapid Transit by Optimal Train Coasting Operation
Authors: Artiya Sopharak, Tosaphol Ratniyomchai, Thanatchai Kulworawanichpong
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This paper presents an energy-saving study of Mass Rapid Transit (MRT) using an optimal train coasting operation. For the dynamic train movement with four modes of operation, including accelerating mode, constant speed or cruising mode, coasting mode, and braking mode are considered in this study. The acceleration rate, the deceleration rate, and the starting coasting point are taken into account the optimal train speed profile during coasting mode with considering the energy saving and acceptable travel time comparison to the based case with no coasting operation. In this study, the mathematical method as a Quadratic Search Method (QDS) is conducted to carry out the optimization problem. A single train of MRT services between two stations with a distance of 2 km and a maximum speed of 80 km/h is taken to be the case study. Regarding the coasting mode operation, the results show that the longer distance of costing mode, the less energy consumption in cruising mode and the less braking energy. On the other hand, the shorter distance of coasting mode, the more energy consumption in cruising mode and the more braking energy.Keywords: energy saving, coasting mode, mass rapid transit, quadratic search method
Procedia PDF Downloads 29212502 Distance Learning in Vocational Mass Communication Courses during COVID-19 in Kuwait: A Media Richness Perspective of Students’ Perceptions
Authors: Husain A. Murad, Ali A. Dashti, Ali Al-Kandari
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The outbreak of Coronavirus during the Spring semester of 2020 brought new challenges for the teaching of vocational mass communication courses at universities in Kuwait. Using the Media Richness Theory (MRT), this study examines the response of 252 university students on mass communication programs. A questionnaire regarding their perceptions and preferences concerning modes of instruction on vocational courses online, focusing on the four factors of MRT: immediacy of feedback, capacity to include personal focus, conveyance of multiple cues, and variety of language. The outcomes show that immediacy of feedback predicted all criterion variables: suitability of distance learning (DL) for teaching vocational courses, sentiments of students toward DL, perceptions of easiness of evaluation of DL coursework, and the possibility of retaking DL courses. Capacity to include personal focus was another positive predictor of the criterion variables. It predicted students’ sentiments toward DL and the possibility of retaking DL courses. The outcomes are discussed in relation to implications for using DL, as well as constructing an agenda for DL research.Keywords: distance learning, media richness theory, traditional learning, vocational media courses
Procedia PDF Downloads 6412501 The Sources of Anti-Immigrant Sentiments in Russia
Authors: Anya Glikman, Anastasia Gorodzeisky
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Since the late 1990th labor immigration and its consequences on the society have become one of the most frequently discussed and debated issues in Russia. Social scientists point that the negative attitudes towards immigrants among Russian majority population is widespread, and their level, at least, twice as high as their level in most other European countries. Moreover, recent study by Gorodzeisky, Glikman and Maskyleison (2014) demonstrates that the two sets of individual level predictors of anti-foreigner sentiment – socio-economic status and conservative views and ideologies – that have been repeatedly proved in research in Western countries are not effective in predicting of anti-foreigner sentiment in Post-Socialist Russia. Apparently, the social mechanisms underlying anti-foreigner sentiment in Western countries, which are characterized by stable regimes and relatively long immigration histories, do not play a significant role in the explanation of anti-foreigner sentiment in Post-Socialist Russia. The present study aims to examine alternative possible sources of anti-foreigner sentiment in Russia while controlling for socio-economic position of individuals and conservative views. More specifically, following the research literature on the topic worldwide, we aim to examine whether and to what extent human values (such as tradition, universalism, safety and power), ethnic residential segregation, fear of crime and exposure to mass media affect anti-foreigner sentiments in Russia. To do so, we estimate a series of multivariate regression equations using the data obtained from 2012 European Social Survey. The national representative sample consists of 2337 Russian born respondents. Descriptive results reveal that about 60% percent of Russians view the impact of immigrants on the country in negative terms. Further preliminary analysis show that anti-foreigner sentiments are associated with exposer to mass media as well as with fear of crime. Specifically, respondents who devoted more time watching news on TV channels and respondents who express higher levels of fear of crime tend to report higher levels of anti-immigrants sentiments. The findings would be discussed in light of sociological perspective and the context of Russian society.Keywords: anti-immigrant sentiments, fear of crime, human values, mass media, Russia
Procedia PDF Downloads 44912500 Single Cell Sorter Driven by Resonance Vibration of Cell Culture Substrate
Authors: Misa Nakao, Yuta Kurashina, Chikahiro Imashiro, Kenjiro Takemura
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The Research Goal: With the growing demand for regenerative medicine, an effective mass cell culture process is required. In a repetitive subculture process for proliferating cells, preparing single cell suspension which does not contain any cell aggregates is highly required because cell aggregates often raise various undesirable phenomena, e.g., apoptosis and decrease of cell proliferation. Since cell aggregates often occur in cell suspension during conventional subculture processes, this study proposes a single cell sorter driven by a resonance vibration of a cell culture substrate. The Method and the Result: The single cell sorter is simply composed of a cell culture substrate and a glass pipe vertically placed against the cell culture substrate with a certain gap corresponding to a cell diameter. The cell culture substrate is made of biocompatible stainless steel with a piezoelectric ceramic disk glued to the bottom side. Applying AC voltage to the piezoelectric ceramic disk, an out-of-plane resonance vibration with a single nodal circle of the cell culture substrate can be excited at 5.5 kHz. By doing so, acoustic radiation force is emitted, and then cell suspension containing only single cells is pumped into the pipe and collected. This single cell sorter is effective to collect single cells selectively in spite of its quite simple structure. We collected C2C12 myoblast cell suspension by the single cell sorter with the vibration amplitude of 12 µmp-p and evaluated the ratio of single cells in number against the entire cells in the suspension. Additionally, we cultured the collected cells for 72 hrs and measured the number of cells after the cultivation in order to evaluate their proliferation. As a control sample, we also collected cell suspension by conventional pipetting, and evaluated the ratio of single cells and the number of cells after the 72-hour cultivation. The ratio of single cells in the cell suspension collected by the single cell sorter was 98.2%. This ratio was 9.6% higher than that collected by conventional pipetting (statistically significant). Moreover, the number of cells cultured for 72 hrs after the collection by the single cell sorter yielded statistically more cells than that collected by pipetting, resulting in a 13.6% increase in proliferated cells. These results suggest that the cell suspension collected by the single cell sorter driven by the resonance vibration hardly contains cell aggregates whose diameter is larger than the gap between the cell culture substrate and the pipe. Consequently, the cell suspension collected by the single cell sorter maintains high cell proliferation. Conclusions: In this study, we developed a single cell sorter capable of sorting and pumping single cells by a resonance vibration of a cell culture substrate. The experimental results show the single cell sorter collects single cell suspension which hardly contains cell aggregates. Furthermore, the collected cells show higher proliferation than that of cells collected by conventional pipetting. This means the resonance vibration of the cell culture substrate can benefit us with the increase in efficiency of mass cell culture process for clinical applications.Keywords: acoustic radiation force, cell proliferation, regenerative medicine, resonance vibration, single cell sorter
Procedia PDF Downloads 25312499 Development of the Food Market of the Republic of Kazakhstan in the Field of Milk Processing
Authors: Gulmira Zhakupova, Tamara Tultabayeva, Aknur Muldasheva, Assem Sagandyk
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The development of technology and production of products with increased biological value based on the use of natural food raw materials are important tasks in the policy of the food market of the Republic of Kazakhstan. For Kazakhstan, livestock farming, in particular sheep farming, is the most ancient and developed industry and way of life. The history of the Kazakh people is largely connected with this type of agricultural production, with established traditions using dairy products from sheep's milk. Therefore, the development of new technologies from sheep’s milk remains relevant. In addition, one of the most promising areas for the development of food technology for therapeutic and prophylactic purposes is sheep milk products as a source of protein, immunoglobulins, minerals, vitamins, and other biologically active compounds. This article presents the results of research on the study of milk processing technology. The objective of the study is to study the possibilities of processing sheep milk and its role in human nutrition, as well as the results of research to improve the technology of sheep milk products. The studies were carried out on the basis of sanitary and hygienic requirements for dairy products in accordance with the following test methods. To perform microbiological analysis, we used the method for identifying Salmonella bacteria (Horizontal method for identifying, counting, and serotyping Salmonella) in a certain mass or volume of product. Nutritional value is a complex of properties of food products that meet human physiological needs for energy and basic nutrients. The protein mass fraction was determined by the Kjeldahl method. This method is based on the mineralization of a milk sample with concentrated sulfuric acid in the presence of an oxidizing agent, an inert salt - potassium sulfate, and a catalyst - copper sulfate. In this case, the amino groups of the protein are converted into ammonium sulfate dissolved in sulfuric acid. The vitamin composition was determined by HPLC. To determine the content of mineral substances in the studied samples, the method of atomic absorption spectrophotometry was used. The study identified the technological parameters of sheep milk products and determined the prospects for researching sheep milk products. Microbiological studies were used to determine the safety of the study product. According to the results of the microbiological analysis, no deviations from the norm were identified. This means high safety of the products under study. In terms of nutritional value, the resulting products are high in protein. Data on the positive content of amino acids were also obtained. The results obtained will be used in the food industry and will serve as recommendations for manufacturers.Keywords: dairy, milk processing, nutrition, colostrum
Procedia PDF Downloads 4312498 Seasonal Influence on Environmental Indicators of Beach Waste
Authors: Marcus C. Garcia, Giselle C. Guimarães, Luciana H. Yamane, Renato R. Siman
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The environmental indicators and the classification of beach waste are essential tools to diagnose the current situation and to indicate ways to improve the quality of this environment. The purpose of this paper was to perform a quali-quantitative analysis of the beach waste on the Curva da Jurema Beach (Espírito Santo - Brazil). Three transects were used with equidistant positioning over the total length of the beach for the solid waste collection. Solid wastes were later classified according to their use and primary raw material from the low and high summer season. During the low season, average values of 7.10 items.m-1, 18.22 g.m-1 and 0.91 g.m-2 were found for the whole beach, and transect 3 contributed the most waste, with the total sum of items equal to 999 (49%), a total mass of 5.62 kg and a total volume of 21.31 L. During the high summer season, average values of 8.22 items.m-1, 54.40 g.m-1 and 2.72 g.m-2 were found, with transect 2 contributing the most to the total sum with 1,212 items (53%), a total mass of 10.76 kg and a total volume of 51.99 L. Of the total collected, plastic materials represented 51.4% of the total number of items, 35.9% of the total mass and 68% of the total volume. The implementation of reactive and proactive measures is necessary so that the management of the solid wastes on Curva da Jurema Beach is in accordance with principles of sustainability.Keywords: beach solid waste, environmental indicators, quali-quantitative analysis, waste management
Procedia PDF Downloads 29912497 Evaluation on Effective Size and Hysteresis Characteristics of CHS Damper
Authors: Daniel Y. Abebe, Jaehyouk Choi
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This study aims to evaluate the effective size and hysteresis characteristics of Circular Hollow Steel (CHS) damper. CHS damper is among steel dampers which are used widely for seismic energy dissipation because they are easy to install, maintain and are low cost. CHS damper dissipates seismic energy through metallic deformation due to the geometrical elasticity of circular shape and fatigue resistance around connection part. After calculating the effective size, which is found to be height to diameter ratio of √ ("3”), nonlinear FE analyses were conducted to evaluate the hysteresis characteristics. To verify the analysis simulation quasi static loading was carried out and the result was compared and satisfactory result was obtained.Keywords: SS400 steel, circular hollow steel damper, effective size, quasi static loading, FE analysis
Procedia PDF Downloads 41912496 Formulation of Mortars with Marine Sediments
Authors: Nor-Edine Abriak, Mouhamadou Amar, Mahfoud Benzerzour
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The transition to a more sustainable economy is directed by a reduction in the consumption of raw materials in equivalent production. The recovery of byproducts and especially the dredged sediment as mineral addition in cements matrix represents an alternative to reduce raw material consumption and construction sector’s carbon footprint. However, the efficient use of sediment requires adequate and optimal treatment. Several processing techniques have so far been applied in order to improve some physicochemical properties. The heat treatment by calcination was effective in removing the organic fraction and activates the pozzolanic properties. In this article, the effect of the optimized heat treatment of marine sediments in the physico-mechanical and environmental properties of mortars are shown. A finding is that the optimal substitution of a portion of cement by treated sediments by calcination at 750 °C helps to maintain or improve the mechanical properties of the cement matrix in comparison with a standard reference mortar. The use of calcined sediment enhances mortar behavior in terms of mechanical strength and durability. From an environmental point of view and life cycle, mortars formulated containing treated sediments are considered inert with respect to the inert waste storage facilities reference (ISDI-France).Keywords: sediment, calcination, cement, reuse
Procedia PDF Downloads 17512495 Aerobic Training Combined with Nutritional Guidance as an Effective Strategy for Improving Aerobic Fitness and Reducing BMI in Inactive Adults
Authors: Leif Inge Tjelta, Gerd Lise Nordbotten, Cathrine Nyhus Hagum, Merete Hagen Helland
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Overweight and obesity can lead to numerous health problems, and inactive people are more often overweight and obese compared to physically active people. Even a moderate weight loss can improve cardiovascular and endocrine disease risk factors. The aim of the study was to examine to what extent overweight and obese adults starting up with two weekly intensive running sessions had an increase in aerobic capacity, reduction in BMI and waist circumference and changes in body composition after 33 weeks of training. An additional aim was to see if there were differences between participants who, in addition to training, also received lifestyle modification education, including practical cooking (nutritional guidance and training group (NTG =32)) compared to those who were not given any nutritional guidance (training group (TG=40)). 72 participants (49 women), mean age of 46.1 ( ± 10.4) were included. Inclusion Criteria: Previous untrained and inactive adults in all age groups, BMI ≥ 25, desire to become fitter and reduce their BMI. The two weekly supervised training sessions consisted of 10 min warm up followed by 20 to 21 min effective interval running where the participants’ heart rate were between 82 and 92% of hearth rate maximum. The sessions were completed with ten minutes whole body strength training. Measures of BMI, waist circumference (WC) and 3000m running time were performed at the start of the project (T1), after 15 weeks (T2) and at the end of the project (T3). Measurements of fat percentage, muscle mass, and visceral fat were performed at T1 and T3. Twelve participants (9 women) from both groups, who all scored around average on the 3000 m pre-test, were chosen to do a VO₂max test at T1 and T3. The NTG were given ten theoretical sessions (80 minutes each) and eight practical cooking sessions (140 minutes each). There was a significant reduction in bout groups for WC and BMI from T1 to T2. There was not found any further reduction from T2 to T3. Although not significant, NTG reduced their WC more than TG. For both groups, the percentage reduction in WC was similar to the reduction in BMI. There was a decrease in fat percentage in both groups from pre-test to post-test, whereas, for muscle mass, a small, but insignificant increase was observed for both groups. There was a decrease in 3000m running time for both groups from T1 to T2 as well as from T2 to T3. The difference between T2 and T3 was not statistically significant. The 12 participants who tested VO₂max had an increase of 2.86 ( ± 3.84) mlkg⁻¹ min⁻¹ in VO₂max and 3:02 min (± 2:01 min) reduction in running time over 3000 m from T1 until T3. There was a strong, negative correlation between the two variables. The study shows that two intensive running session in 33 weeks can increase aerobic fitness and reduce BMI, WC and fat percent in inactive adults. Cost guidance in addition to training will give additional effect.Keywords: interval training, nutritional guidance, fitness, BMI
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