Search results for: standard penetration test
2380 Flocculation and Settling Rate Studies of Clean Coal Fines at Different Flocculants Dosage, pH Values, Bulk Density and Particle Size
Authors: Patel Himeshkumar Ashokbhai, Suchit Sharma, Arvind Kumar Garg
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The results obtained from settling test of coal fines are used as an important tool to select the dewatering equipment such as thickeners, centrifuges and filters. Coal being hydrophobic in nature does not easily settle when mixed with water. Coal slurry that takes longer time to release water is highly undesirable because it poses additional challenge during sedimentation, centrifuge and filtration. If filter cake has higher than permitted moisture content then it not only creates handling problems but inflated freight costs and reduction in input and productivity for coke oven charges. It is to be noted that coal fines drastically increase moisture percentage in filter cake hence are to be minimized. To increase settling rate of coal fines in slurry chemical substances called flocculants or coagulants are added that cause coal particles to flocculate or coalesce into larger particles. These larger particles settle at faster rate and have higher settling velocity. Other important factors affecting settling rate are flocculent dosage, slurry or pulp density and particle size. Hence in this paper we tried to study the settling characteristic of clean coal fines by varying one of the four factors namely 1. Flocculant Dosage (acryl-amide) 2. pH of the water 3. Bulk density 4. Particle size of clean coal fines in settling experiment and drew important conclusions. Result of this paper will be much useful not only for coal beneficiation plant design but also for cost reduction of coke production facilities.Keywords: bulk density, coal fines, flocculants, flocculation, settling velocity, pH
Procedia PDF Downloads 3222379 Comparative Histological, Immunohistochemical and Biochemical Study on the Effect of Vit. C, Vit. E, Gallic Acid and Silymarin on Carbon Tetrachloride Model of Liver Fibrosis in Rats
Authors: Safaa S. Hassan, Mohammed H. Elbakry, Safwat A. Mangoura, Zainab M. Omar
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Background: Liver fibrosis is the main reason for increased mortality in chronic liver disease. It has no standard treatment. Antioxidants from a variety of sources are capable of slowing or preventing oxidation of other molecules. Aim: to evaluate the hepatoprotective effect of vit. C, vit. E and gallic acid in comparison to silymarin in the rat model of carbon tetrachloride induced liver fibrosis and their possible mechanisms of action. Material& Methods: A total number of 60 adult male albino rats 160-200gm were divided into six equal groups; received subcutaneous (s.c) injection for 8 weeks. Group I: as control. Group II: received 1.5 mL/kg of CCL4 .Group III: CCL4 and co- treatment with silymarin 100mg/kg p.o. daily. Group IV: CCL4 and co-treatment with vit. C 50mg/kg p.o. daily. Group V: CCL4 and co-treatment with vit. E 200mg/kg. p.o. Group VI: CCL4 and co-treatment with Gallic acid 100mg/kg. p.o. daily. Liver was processed for histological and immunohistochemical examination. Levels of AST, ALT, ALP, reduced GSH, MDA, SOD and hydroxyproline concentration were measured and evaluated statistically. Results: Light and electron microscopic examination of liver of group II exhibited foci of altered cells with dense nuclei and vacuolated, granular cytoplasm, mononuclear cell infiltration in portal areas, profuse collagen fiber deposits were found around portal tract, more intense staining α-SMA-positive cells occupied most of the liver fibrosis tissue, electron lucent areas in the cytoplasm of the hepatocytes, margination of nuclear chromatin. Treatment by any of the antioxidants variably reduced the hepatic structural changes induced by CCL4. Biochemical analysis showed that carbon tetrachloride significantly increased the levels of serum AST, ALT, ALP, hepatic malondialdehyde and hydroxyproline content. Moreover, it decreased the activities of superoxide dismutase and glutathione. Treatment with silymarin, gallic acid, vit. C and vit. E decreased significantly the AST, ALT, and ALP levels in plasma, MDA and hydroxyproline and increased the activities of SOD and glutathione in liver tissue. The effect of administration of CCl4 was improved with the used antioxidants in variable degrees. The most efficient antioxidant was silymarin followed by gallic acid and vit. C then vit. E. It is possibly due to their antioxidant effect, free radical scavenging properties and the reduction of oxidant dependent activation and proliferation of HSCs. Conclusion: So these antioxidants can be a promising drugs candidate for ameliorating liver fibrosis better than the use of the drugs and their side effects.Keywords: antioxidant, ccl4, gallic acid, liver fibrosis
Procedia PDF Downloads 2712378 Hardware-In-The-Loop Relative Motion Control: Theory, Simulation and Experimentation
Authors: O. B. Iskender, K. V. Ling, V. Dubanchet, L. Simonini
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This paper presents a Guidance and Control (G&C) strategy to address spacecraft maneuvering problem for future Rendezvous and Docking (RVD) missions. The proposed strategy allows safe and propellant efficient trajectories for space servicing missions including tasks such as approaching, inspecting and capturing. This work provides the validation test results of the G&C laws using a Hardware-In-the-Loop (HIL) setup with two robotic mockups representing the chaser and the target spacecraft. Through this paper, the challenges of the relative motion control in space are first summarized, and in particular, the constraints imposed by the mission, spacecraft and, onboard processing capabilities. Second, the proposed algorithm is introduced by presenting the formulation of constrained Model Predictive Control (MPC) to optimize the fuel consumption and explicitly handle the physical and geometric constraints in the system, e.g. thruster or Line-Of-Sight (LOS) constraints. Additionally, the coupling between translational motion and rotational motion is addressed via dual quaternion based kinematic description and accordingly explained. The resulting convex optimization problem allows real-time implementation capability based on a detailed discussion on the computational time requirements and the obtained results with respect to the onboard computer and future trends of space processors capabilities. Finally, the performance of the algorithm is presented in the scope of a potential future mission and of the available equipment. The results also cover a comparison between the proposed algorithms with Linear–quadratic regulator (LQR) based control law to highlight the clear advantages of the MPC formulation.Keywords: autonomous vehicles, embedded optimization, real-time experiment, rendezvous and docking, space robotics
Procedia PDF Downloads 1242377 Maximum Likelihood Estimation Methods on a Two-Parameter Rayleigh Distribution under Progressive Type-Ii Censoring
Authors: Daniel Fundi Murithi
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Data from economic, social, clinical, and industrial studies are in some way incomplete or incorrect due to censoring. Such data may have adverse effects if used in the estimation problem. We propose the use of Maximum Likelihood Estimation (MLE) under a progressive type-II censoring scheme to remedy this problem. In particular, maximum likelihood estimates (MLEs) for the location (µ) and scale (λ) parameters of two Parameter Rayleigh distribution are realized under a progressive type-II censoring scheme using the Expectation-Maximization (EM) and the Newton-Raphson (NR) algorithms. These algorithms are used comparatively because they iteratively produce satisfactory results in the estimation problem. The progressively type-II censoring scheme is used because it allows the removal of test units before the termination of the experiment. Approximate asymptotic variances and confidence intervals for the location and scale parameters are derived/constructed. The efficiency of EM and the NR algorithms is compared given root mean squared error (RMSE), bias, and the coverage rate. The simulation study showed that in most sets of simulation cases, the estimates obtained using the Expectation-maximization algorithm had small biases, small variances, narrower/small confidence intervals width, and small root of mean squared error compared to those generated via the Newton-Raphson (NR) algorithm. Further, the analysis of a real-life data set (data from simple experimental trials) showed that the Expectation-Maximization (EM) algorithm performs better compared to Newton-Raphson (NR) algorithm in all simulation cases under the progressive type-II censoring scheme.Keywords: expectation-maximization algorithm, maximum likelihood estimation, Newton-Raphson method, two-parameter Rayleigh distribution, progressive type-II censoring
Procedia PDF Downloads 1612376 Hydraulic Optimization of an Adjustable Spiral-Shaped Evaporator
Authors: Matthias Feiner, Francisco Javier Fernández García, Michael Arneman, Martin Kipfmüller
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To ensure reliability in miniaturized devices or processes with increased heat fluxes, very efficient cooling methods have to be employed in order to cope with small available cooling surfaces. To address this problem, a certain type of evaporator/heat exchanger was developed: It is called a swirl evaporator due to its flow characteristic. The swirl evaporator consists of a concentrically eroded screw geometry in which a capillary tube is guided, which is inserted into a pocket hole in components with high heat load. The liquid refrigerant R32 is sprayed through the capillary tube to the end face of the blind hole and is sucked off against the injection direction in the screw geometry. Its inner diameter is between one and three millimeters. The refrigerant is sprayed into the pocket hole via a small tube aligned in the center of the bore hole and is sucked off on the front side of the hole against the direction of injection. The refrigerant is sucked off in a helical geometry (twisted flow) so that it is accelerated against the hot wall (centrifugal acceleration). This results in an increase in the critical heat flux of up to 40%. In this way, more heat can be dissipated on the same surface/available installation space. This enables a wide range of technical applications. To optimize the design for the needs in various fields of industry, like the internal tool cooling when machining nickel base alloys like Inconel 718, a correlation-based model of the swirl-evaporator was developed. The model is separated into 3 subgroups with overall 5 regimes. The pressure drop and heat transfer are calculated separately. An approach to determine the locality of phase change in the capillary and the swirl was implemented. A test stand has been developed to verify the simulation.Keywords: helically-shaped, oil-free, R-32, swirl-evaporator, twist-flow
Procedia PDF Downloads 1072375 Landscape Pattern Evolution and Optimization Strategy in Wuhan Urban Development Zone, China
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With the rapid development of urbanization process in China, its environmental protection pressure is severely tested. So, analyzing and optimizing the landscape pattern is an important measure to ease the pressure on the ecological environment. This paper takes Wuhan Urban Development Zone as the research object, and studies its landscape pattern evolution and quantitative optimization strategy. First, remote sensing image data from 1990 to 2015 were interpreted by using Erdas software. Next, the landscape pattern index of landscape level, class level, and patch level was studied based on Fragstats. Then five indicators of ecological environment based on National Environmental Protection Standard of China were selected to evaluate the impact of landscape pattern evolution on the ecological environment. Besides, the cost distance analysis of ArcGIS was applied to simulate wildlife migration thus indirectly measuring the improvement of ecological environment quality. The result shows that the area of land for construction increased 491%. But the bare land, sparse grassland, forest, farmland, water decreased 82%, 47%, 36%, 25% and 11% respectively. They were mainly converted into construction land. On landscape level, the change of landscape index all showed a downward trend. Number of patches (NP), Landscape shape index (LSI), Connection index (CONNECT), Shannon's diversity index (SHDI), Aggregation index (AI) separately decreased by 2778, 25.7, 0.042, 0.6, 29.2%, all of which indicated that the NP, the degree of aggregation and the landscape connectivity declined. On class level, the construction land and forest, CPLAND, TCA, AI and LSI ascended, but the Distribution Statistics Core Area (CORE_AM) decreased. As for farmland, water, sparse grassland, bare land, CPLAND, TCA and DIVISION, the Patch Density (PD) and LSI descended, yet the patch fragmentation and CORE_AM increased. On patch level, patch area, Patch perimeter, Shape index of water, farmland and bare land continued to decline. The three indexes of forest patches increased overall, sparse grassland decreased as a whole, and construction land increased. It is obvious that the urbanization greatly influenced the landscape evolution. Ecological diversity and landscape heterogeneity of ecological patches clearly dropped. The Habitat Quality Index continuously declined by 14%. Therefore, optimization strategy based on greenway network planning is raised for discussion. This paper contributes to the study of landscape pattern evolution in planning and design and to the research on spatial layout of urbanization.Keywords: landscape pattern, optimization strategy, ArcGIS, Erdas, landscape metrics, landscape architecture
Procedia PDF Downloads 1632374 Gender and Language: Exploring Sociolinguistic Differences
Authors: Marvelyn F. Carolino, Charlene R. Cunanan, Gellien Faith O. Masongsong, Berlinda A. Ofrecio
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This study delves into the language usage differences among men, women, and individuals with other gender preferences. It specifically centers on the sociolinguistic aspects within the English majors at the College of Education of Rizal Technological University-Pasig, spanning from the first-year to fourth-year levels. The researchers employed a triangulation approach for data collection, utilizing a validated self-made questionnaire, interviews, and observations. The results revealed that language usage among different genders is influenced by a combination of cultural norms, social dynamics, and technological factors. Cultural norms significantly shape how respondents use language, as they conform to expected speech patterns based on their gender. Social factors, such as peer pressure, were found to impact language usage for individuals of all genders. This influence was viewed as constructive for personal development rather than inhibiting performance or communication. In terms of technological factors, respondents strongly agreed that the time spent on social media and educational applications influenced their language use. These platforms provided opportunities to expand and enhance their vocabulary. Additionally, the study employed hypothesis testing through the z-test formula to assess the impact of demographic profiles on language usage differences among genders. The results indicated that gender, economic status, locality, and ethnicity did not show statistically significant differences in language use. This lack of significant variation in findings was attributed to the relatively homogeneous demographic profile of respondents, primarily composed of females with low-income backgrounds and Tagalog ethnicity. This demographic similarity likely minimized the diversity of responses.Keywords: gender, language, sociolinguistics, differences
Procedia PDF Downloads 972373 Compensation Strategies and Their Effects on Employees' Motivation and Organizational Citizenship Behaviour in Some Manufacturing Companies in Lagos, Nigeria
Authors: Ade Oyedijo
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This paper reports the findings of a study on the strategic and organizational antecedents and effects of two opposing pay patterns used by some manufacturing companies in Lagos Nigeria with particular reference to the behavioural correlates of the pay strategies considered. The assumed relationship between pay strategies and some organizational correlates such as business and corporate strategies and firm size was considered problematic in view of their likely implications for employee motivation and citizenship behaviour and firm performance. The survey research method was used for the study. Structured, close ended questions were used to collect primary data from the respondents. A multipart Likert scale was used to measure the pay orientations of the respondent firms and the job and organizational involvement of the respondent employees. Utilizing hierarchical linear regression method and "t-test" to analyze the data obtained from 48 manufacturing companies of various sizes and strategies, it was found that the dominant pattern of employee compensation in the sampled manufacturing companies. The study also revealed that the choice of a pay strategy was strongly influenced by organizational size as well as the type of business and corporate level strategies adopted by afirm. Firms pursuing a strategy of related and unrelated diversification are more likely to adopt the algorithmic compensation system than single product firms because of their relatively larger size and scope. However; firms that pursue a competitive advantage through a business level strategy of cost efficiency are more likely to use the experiential, variable pay strategy. The study found that an algorithmic compensation strategy is as effective as experiential compensation strategy in the promotion of organizational citizenship behaviour and motivation of employees.Keywords: compensation, corporate strategy, business strategy, motivation, citizenship behaviour, algorithmic, experiential, organizational commitment, work environment
Procedia PDF Downloads 3882372 Cardiac Arrest after Cardiac Surgery
Authors: Ravshan A. Ibadov, Sardor Kh. Ibragimov
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Objective. The aim of the study was to optimize the protocol of cardiopulmonary resuscitation (CPR) after cardiovascular surgical interventions. Methods. The experience of CPR conducted on patients after cardiovascular surgical interventions in the Department of Intensive Care and Resuscitation (DIR) of the Republican Specialized Scientific-Practical Medical Center of Surgery named after Academician V. Vakhidov is presented. The key to the new approach is the rapid elimination of reversible causes of cardiac arrest, followed by either defibrillation or electrical cardioversion (depending on the situation) before external heart compression, which may damage sternotomy. Careful use of adrenaline is emphasized due to the potential recurrence of hypertension, and timely resternotomy (within 5 minutes) is performed to ensure optimal cerebral perfusion through direct massage. Out of 32 patients, cardiac arrest in the form of asystole was observed in 16 (50%), with hypoxemia as the cause, while the remaining 16 (50%) experienced ventricular fibrillation caused by arrhythmogenic reactions. The age of the patients ranged from 6 to 60 years. All patients were evaluated before the operation using the ASA and EuroSCORE scales, falling into the moderate-risk group (3-5 points). CPR was conducted for cardiac activity restoration according to the American Heart Association and European Resuscitation Council guidelines (Ley SJ. Standards for Resuscitation After Cardiac Surgery. Critical Care Nurse. 2015;35(2):30-38). The duration of CPR ranged from 8 to 50 minutes. The ARASNE II scale was used to assess the severity of patients' conditions after CPR, and the Glasgow Coma Scale was employed to evaluate patients' consciousness after the restoration of cardiac activity and sedation withdrawal. Results. In all patients, immediate chest compressions of the necessary depth (4-5 cm) at a frequency of 100-120 compressions per minute were initiated upon detection of cardiac arrest. Regardless of the type of cardiac arrest, defibrillation with a manual defibrillator was performed 3-5 minutes later, and adrenaline was administered in doses ranging from 100 to 300 mcg. Persistent ventricular fibrillation was also treated with antiarrhythmic therapy (amiodarone, lidocaine). If necessary, infusion of inotropes and vasopressors was used, and for the prevention of brain edema and the restoration of adequate neurostatus within 1-3 days, sedation, a magnesium-lidocaine mixture, mechanical intranasal cooling of the brain stem, and neuroprotective drugs were employed. A coordinated effort by the resuscitation team and proper role allocation within the team were essential for effective cardiopulmonary resuscitation (CPR). All these measures contributed to the improvement of CPR outcomes. Conclusion. Successful CPR following cardiac surgical interventions involves interdisciplinary collaboration. The application of an optimized CPR standard leads to a reduction in mortality rates and favorable neurological outcomes.Keywords: cardiac surgery, cardiac arrest, resuscitation, critically ill patients
Procedia PDF Downloads 522371 Retrospective Statistical Study on the Evolution of Brucellosis during the Last Decade (2011-2021) in Medea, Algeria
Authors: Mammar Khames, Mustapha Oumouna
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Brucellosis is one of the most common zoonoses in the world. It represents a serious threat to human health; the existence of brucellosis in Algeria dates back to the beginning of the 19th century. Its transmission to humans is through coccobacilli of the genus Brucella following direct contact with contaminated animals or indirectly through the consumption of their unpasteurized dairy products. The present investigation covers a retrospective study on human brucellosis in the district of Medea over a period from 2011 to 2021 at the level of two public health establishments. In the first place, it is at the level of the Directorate of Public Health and in the infectious department level at Medea Hospital, and at the level of the directorate of agricultural services in the third place. The results showed that during these eleven years of study, 795 cases were collected from the department of health and population, and 141 cases were collected from the infectious department of the district of Medea. A total of 56 cases of bovine brucellosis were obtained from the directorate of agricultural services of the district of Medea. Human brucellosis affects all age groups with different percentages, but the rate has been higher in the 20-44 age group, with a predominance of men. However, the geographic distribution map of the cases shows that the western part of the district was the most affected. A cohort of 141 cases was hospitalized at the infectious service level of Medea Hospital. They were 89 men and 52 women. The most common age reached is [20-44] years. The majority were of rural origin. Two serological reactions were performed for diagnosis: the buffered antigen test and Wright's serodiagnosis. Bovine brucellosis affects all age groups with different percentages, but the rate was higher in the 2-to-4-year age group, with a predominance of females. From these data, we conclude that brucellosis has a strong spread in the region studied.Keywords: human brucellosis, serology, Medea, Algeria
Procedia PDF Downloads 622370 Shape Memory Alloy Structural Damper Manufactured by Selective Laser Melting
Authors: Tiziana Biasutti, Daniela Rigamonti, Lorenzo Palmiotti, Adelaide Nespoli, Paolo Bettini
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Aerospace industry is based on the continuous development of new technologies and solutions that allows constant improvement of the systems. Shape Memory Alloys are smart materials that can be used as dampers due to their pseudoelastic effect. The purpose of the research was to design a passive damper in Nitinol, manufactured by Selective Laser Melting, for space applications to reduce vibration between different structural parts in space structures. The powder is NiTi (50.2 at.% of Ni). The structure manufactured by additive technology allows us to eliminate the presence of joint and moving parts and to have a compact solution with high structural strength. The designed dampers had single or double cell structures with three different internal angles (30°, 45° and 60°). This particular shape has damping properties also without the pseudoelastic effect. For this reason, the geometries were reproduced in different materials, SS316L and Ti6Al4V, to test the geometry loss factor. The mechanical performances of these specimens were compared to the ones of NiTi structures, pointing out good damping properties of the designed structure and the highest performances of the NiTi pseudoelastic effect. The NiTi damper was mechanically characterized by static and dynamic tests and with DSC and microscope observations. The experimental results were verified with numerical models and with some scaled steel specimens in which optical fibers were embedded. The realized structure presented good mechanical and damping properties. It was observed that the loss factor and the dissipated energy increased with the angles of the cells.Keywords: additive manufacturing, damper, nitinol, pseudo elastic effect, selective laser melting, shape memory alloys
Procedia PDF Downloads 1052369 Screening Psychological Wellness in a South African Banking Industry: Psychometric Properties of the Sense of Coherence-29 Questionnaire and Multifactor Leadership Questionnaire
Authors: Nisha Harry, Keshia Sing
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Orientation: The Multifactor Leadership Questionnaire (MLF) and the sense of coherence-29 (SCS) is an effective tools to assess the prevalence and underlying structures of empirically based taxonomies related to leadership and wellbeing. Research purpose: The purpose of the study was to test the psychometric properties of the SCS and Multifactor Leadership Questionnaire (MLQ) to screen for psychological wellness indices within the banking industry in South Africa. Motivation for the study: The contribution of these two instruments for the purpose of determining psychological wellness in a banking work environment is unique. Research design, approach, or method: The sample consisted of (N = 150) financial staff employed in a South African banking organisation. The age of the sample was: 37% (30 -40 yrs), 31% (20-30 yrs), 26% (40- 50 yrs), and 6% (50+yrs), of which 52% were males, 48% were females. The white race group was the majority at 29%, African at 26%, Coloured at 23%, and Indian was 22%. Main findings: Results from the exploratory factor analysis revealed a two-factor structure as the most satisfactory. Confirmatory factor analyses revealed the two-factor model displayed better good of-fit indices. Practical implications: The factor structure of the Sense of Coherence-29 scale (SCS), and the Multifactor Leadership Questionnaire (MLQ), have a value-added focus to determine psychological wellness within banking staff. It is essential to take into account these constructs when developing employee wellness interventions. Contribution/value add: Understanding the psychometric properties of the SCS, the self-reported form, and the MLQ questionnaire contributes to screening psychological wellness indices such as coping within the banking industry in a developing country like South Africa. Leaders are an important part of the implementation process of organisational employee wellness practices.Keywords: factorial structure, leadership, measurement invariance, psychological wellness, sense of coherence
Procedia PDF Downloads 1062368 Effect of Phaseolus vulgaris Inoculation on P. vulgaris and Zea mays Growth and Yield Cultivated in Intercropping
Authors: Nour Elhouda Abed, Bedj Mimi, Wahid Slimani, Mourad Atif, Abdelhakim Ouzzane, Hocine Irekti, Abdelkader Bekki
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The most frequent system of cereal production in Algeria is fallow-wheat. This is an extensive system that meets only the half needs some cereals and fodder demand. Resorption of fallow has become a strategic necessity to ensure food security in response to the instability of supply and the persistence of higher food prices on the world market. Despite several attempts to replace the fallow by crop cultures, choosing the best crop remains. Today, the agronomic and economic interests of legumes are demonstrated. However, their crop culture remains marginalized because of the weakness and instability of their performance. In the context of improving legumes and cereals crops as well as fallow resorption, we undertook to test, in the field, the effect of rhizobial inoculation of Phaseolus vulgaris in association with Zea Mays. We firstly studied the genetic diversity of rhizobial strains that nodulate P.vulgaris isolated from fifteen (15) different regions. ARDRA had shown 18 different genetic profiles. Symbiotic characterization highlighted a strain that highly significantly improved the fresh and dry weight of the host plant, in comparison to the negative control (un-inoculated) and the positive control (inoculated with the reference strain CIAT 899). In the field, the selected strain increased significantly the growth and yield of P.vulgaris and Zea Mays comparing to the non-inoculated control. However, the mix inoculation (selected strain+ Ciat 899) had not given the best parameters showing, thus, no synergy between the strains. These results indicate the replacing fallow by a crop legume in intercropping with cereals crops.Keywords: fallow, intercropping, inoculation, legumes-cereals
Procedia PDF Downloads 3652367 Post-Anesthetic Recovery: The Best Moment to Apply Positive Pressure in Airway in Postoperative Bariatric Surgery
Authors: Eli Maria Pazzianotto-Forti, Patrícia Brigatto, Letícia Baltieri, Carolina Moraes Da Costa, Maura Rigoldi Simoes Da Rocha, Irineu Rasera Jr
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The application of positive pressure in airway can contribute to the restoration of lung volumes, capacities and prevent respiratory complications. The aim was to investigate the use of Bilevel Positive Airway Pressure (BIPAP) in morbidly obese in two moments in postoperative bariatric surgery: In the post-anesthetic recovery (PAR) and on the 1st postoperative day (1stPO). Twenty morbidly obese, aged between 25 and 55 years, underwent pulmonary function test and chest X-ray preoperatively and on the day of discharge (2nd day after surgery). They were randomly allocated in groups. GPAR: received BIPAP treatment in PAR, for an hour and G1stPO: received BIPAP for one hour, on the 1stPO. There were significant reductions in slow vital capacity (SVC) (p=0.0007), inspiratory reserve volume (IRV) (p=0.0016) and forced vital capacity (FVC) (p=0.0013) in the postoperative in GPAR and the expiratory reserve volume (ERV) remained (p=0.4446). In the G1stPO, there were significant reductions for: SVC p=<0.0001, ERV p=0.0191, IRV p= 0.0026 and FVC p=<0.0001. Comparing between groups, the SVC (p=0.0027) and FVC (p=0.0028) showed significant difference between the treatments. However, the GPAR showed fewer declines of these capacities. To the ERV (p= 0.1646) and IRV (p=0.3973) there was no significant difference between groups. The atelectasis prevalence was 10% for the GPAR and 30% for G1stPO, with significant difference between the proportions (p = 0.0027). The lowest reduction in SVC and FVC happens when positive pressure is applied in PAR. Thus, the use of BIPAP in the PAR can promote a restoration of ERV and contribute to the reduction of atelectasis. FAPESP 2013/06334-8.Keywords: atelectasis, bariatric surgery, physiotherapy, pulmonary function, positive pressure
Procedia PDF Downloads 4032366 Knowledge and Practice of Family Planning among Rural Women in Ogun State, South West Nigeria
Authors: Tope Olubodun
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Background: Family planning practices help individuals and couples avoid unwanted pregnancies, regulate intervals between pregnancies, and determine the number of children in the family. Family planning is an effective intervention for promoting maternal health, but its acceptability and utilization are impeded by many factors in Southwest Nigeria. Aim: This study was conducted to assess women’s knowledge and practice of family planning in two rural communities in Ogun State, Southwest Nigeria, and to determine factors associated with the utilization of family planning among these women. Methods: This was a cross-sectional study conducted among 561 women of reproductive age selected by multistage sampling. The data collection was done using interviewer-administered questionnaires. Data obtained were analyzed using IBM SPSS Statistics version 20. Frequencies were generated, and chi-square test was used to explore associations. The level of significance was set at 0.05. Result: The majority of the respondents were aware of family planning 410 (73.1%). The method most commonly known was male condom 348 (62.0%), then pills 276 (49.2%) and injectables 231(41.3%). The commonest sources of information on family planning were health workers 158 (26.8%), outreaches 162 (27.5%) and TV/radio 136 (23.1%). Respondents that had used family planning, however, only constituted forty–five percent. The methods commonly used were injectables 104 (39.2%) and pills 85 (32.1%). Reasons for choosing not to use family planning include the desire for more children 78 (26.3%), because spouse does not support family planning 56 (18.9%), fear of unbearable side effects 44 (14.9%), and poor knowledge of the methods of family planning as well as where the services can be obtained 39 (13.2%). There is a statistically significant association between age, ethnicity, education, occupation, average monthly income, and use of family planning. Conclusion: Campaigns that promote male involvement in family planning, use of family planning for child spacing, and dispelling of fears is recommended to improve the practice of family planning among such a group of women.Keywords: family planning, rural, knowledge, practice
Procedia PDF Downloads 1502365 Synergistic Effect of Curcumin and Insulin on GLUT4 Translocation in C2C12 Cell
Authors: Javad Mohiti-Ardekani, Shabodin Asadii, Ali Moradi
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Introduction: Curcumin, the yellow pigment in turmeric, has been shown as an anti-diabetic agent for centuries but only in recent few years, its mechanism of action has been under investigation. Some studies showed that curcumin might exert its anti-diabetic effect via increasing glucose transporter isotype-4 (GLUT4) gene and glycoprotein contents in cells. To investigate this possibility, we investigate the effects of extract and commercial curcumin with and without insulin on GLUT4 translocation from intracellular compartments of nuclear or endoplasmic reticulum membranes (N/ER) into the cytoplasmic membrane (CM). Methods and Material: C2C12 myoblastic cell line were seeded in DMEM plus 20 % FBS and differentiated to myotubes using 2 % horse serum. After myotubes formation, 40 µmolar Extract and Commercial curcumin, with or without insulin as intervention, and as control 1 % DMSO were added for 3 h. Cells were washed and homogenized followed by ultracentrifuge fractionation, protein separation by SDS-PAGE and GLUT4 detection using semi-quantitative Western blotting. Data analysis was done by two independent samples t-test for comparison of mean ± SD of GLUT4 percent in categories. GLUT4 contents were higher in CM groups curcumin and curcumin with insulin in comparison to 1 % DMSO-treated myotubes control group. Results: As our results have shown extract and commercial curcumin induces GLUT4 translocation from intra-cell into cell surface. The results have also shown synergic effect of curcumin on translocation of GLUT4 from intra-cell into cell surface in the presence of 100 nm insulin. Discussion: We conclude that curcumin may be a choice of type-2 diabetes mellitus treatment because its extract and commercial enhances GLUT4 contents in CM where it facilitates glucose entrance into the cell. However, it is necessary to trace the signaling pathways which are activated by curcumin.Keywords: Curcumin, insulin, Diabetes type-2, GLUT4
Procedia PDF Downloads 2422364 Effect of Whole Body Vibration on Posture Stability and Planter Pressure in Patients with Diabetic Neuropathy
Authors: Azza M. Atya, Mahmoud M. Nasser
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Background/ /Significance: Peripheral neuropathy is one of the long term serious complications of diabetes, which may attribute to postural instability and alteration of planter pressure. Whole body vibration (WBV) is a somatosensory stimulation type of exercise that has been emerged in sport training and rehabilitation of neuromuscular disorders. Purpose: The aim of this study was to investigate the effect of whole Body Vibration on antroposterior (AP), mediolateral (ML) posture stability and planter foot pressure in patients with diabetic neuropathy. Subjects: forty diabetic patients with moderate peripheral neuropathy aged from 35 to 50 years, were randomly assigned to WBV group (n=20) and control group (n=20). Methods and Materials: the WBV intervention consisted of three session weekly for 8 weeks (frequency 20 Hz, peak-to peak displacement 4mm, acceleration 3.5 g). Biodex balance system was used for postural stability assessment and the foot scan plate was used to measure the mean peak pressure under the first and lesser metatarsals. The main Outcome measures were antroposterior stability index (APSI), mediolateral stability index (MLSI), overall stability index (OSI),and mean peak foot pressure. Analyses: Statistical analysis was performed using the SPSS software package (SPSS for Windows Release 18.0). T-test was used to compare between the pre- and post-treatment values between and within groups. Results: For the 40 study participants (18male and 22 females) there were no between-group differences at baseline. At the end of 8 weeks, Subjects in WBV group experienced significant increase in postural stability with a reduction of mean peak of planter foot pressure (P<0.05) compared with the control group. Conclusion: The result suggests that WBV is an effective therapeutic modality for increasing postural stability and reducing planter pressure in patients with diabetic neuropathy.Keywords: whole body vibration, diabetic neuropathy, posture stability, foot pressure
Procedia PDF Downloads 3812363 The Evaluation for Interfacial Adhesion between SOFC and Metal Adhesive in the High Temperature Environment
Authors: Sang Koo Jeon, Seung Hoon Nahm, Oh Heon Kwon
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The unit cell of solid oxide fuel cell (SOFC) must be stacked as several layers type to obtain the high power. The most of researcher have concerned about the performance of stacked SOFC rather than the structural stability of stacked SOFC and especially interested how to design for reducing the electrical loss and improving the high efficiency. Consequently, the stacked SOFC able to produce the electrical high power and related parts like as manifold, gas seal, bipolar plate were developed to optimize the stack design. However, the unit cell of SOFC was just layered on the interconnector without the adhesion and the hydrogen and oxygen were injected to the interfacial layer in the high temperature. On the operating condition, the interfacial layer can be the one of the weak point in the stacked SOFC. Therefore the evaluation of the structural safety for the failure is essentially needed. In this study, interfacial adhesion between SOFC and metal adhesive was estimated in the high temperature environment. The metal adhesive was used to strongly connect the unit cell of SOFC with interconnector and provide the electrical conductivity between them. The four point bending test was performed to measure the interfacial adhesion. The unit cell of SOFC and SiO2 wafer were diced and then attached by metal adhesive. The SiO2 wafer had the center notch to initiate a crack from the tip of the notch. The modified stereomicroscope combined with the CCD camera and system for measuring the length was used to observe the fracture behavior. Additionally, the interfacial adhesion was evaluated in the high temperature condition because the metal adhesive was affected by high temperature. Also the specimen was exposed in the furnace during several hours and then the interfacial adhesion was evaluated. Finally, the interfacial adhesion energy was quantitatively determined and compared in the each condition.Keywords: solid oxide fuel cell (SOFC), metal adhesive, adhesion, high temperature
Procedia PDF Downloads 5202362 Identification and Validation of Co-Dominant Markers for Selection of the CO-4 Anthracnose Disease Resistance Gene in Common Bean Cultivar G2333
Authors: Annet Namusoke, Annet Namayanja, Peter Wasswa, Shakirah Nampijja
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Common bean cultivar G2333 which offers broad resistance for anthracnose has been widely used as a source of resistance in breeding for anthracnose resistance. The cultivar is pyramided with three genes namely CO-4, CO-5 and CO-7 and of these three genes, the CO-4 gene has been found to offer the broadest resistance. The main aim of this work was to identify and validate easily assayable PCR based co-dominant molecular markers for selection of the CO-4 gene in segregating populations derived from crosses of G2333 with RWR 1946 and RWR 2075, two commercial Andean cultivars highly susceptible to anthracnose. Marker sequences for the study were obtained by blasting the sequence of the COK-4 gene in the Phaseolus gene database. Primer sequence pairs that were not provided from the Phaseolus gene database were designed by the use of Primer3 software. PCR conditions were optimized and the PCR products were run on 6% HPAGE gel. Results of the polymorphism test indicated that out of 18 identified markers, only two markers namely BM588 and BM211 behaved co-dominantly. Phenotypic evaluation for reaction to anthracnose disease was done by inoculating 21days old seedlings of three parents, F1 and F2 populations with race 7 of Colletotrichum lindemuthianum in the humid chamber. DNA testing of the BM588 marker onto the F2 segregating population of the crosses RWR 1946 x G 2333 and RWR 2075 x G2333 further revealed that the marker BM588 co-segregated with disease resistance with co-dominance of two alleles of 200bp and 400bp, fitting the expected segregation ratio of 1:2:1. The BM588 marker was significantly associated with disease resistance and gave promising results for marker assisted selection of the CO-4 gene in the breeding lines. Activities to validate the BM211 marker are also underway.Keywords: codominant, Colletotrichum lindemuthianum, MAS, Phaseolus vulgaris
Procedia PDF Downloads 2912361 Experimental Study on Strength Development of Low Cement Concrete Using Mix Design for Both Binary and Ternary Mixes
Authors: Mulubrhan Berihu, Supratic Gupta, Zena Gebriel
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Due to the design versatility, availability, and cost efficiency, concrete is continuing to be the most used construction material on earth. However, the production of Portland cement, the primary component of concrete mix is causing to have a serious effect on environmental and economic impacts. This shows there is a need to study using of supplementary cementitious materials (SCMs). The most commonly used supplementary cementitious materials are wastes and the use of these industrial waste products has technical, economical and environmental benefits besides the reduction of CO2 emission from cement production. The study aims to document the effect on strength property of concrete due to use of low cement by maximizing supplementary cementitious materials like fly ash or marble powder. Based on the different mix proportion of pozzolana and marble powder a range of mix design was formulated. The first part of the project is to study the strength of low cement concrete using fly ash replacement experimentally. The test results showed that using up to 85 kg/m3 of cement is possible for plain concrete works like hollow block concrete to achieve 9.8 Mpa and the experimental results indicates that strength is a function of w/b. In the second part a new set of mix design has been carried out with fly ash and marble powder to study the strength of both binary and ternary mixes. In this experimental study, three groups of mix design (c+FA, c+FA+m and c+m), four sets of mixes for each group were taken up. Experimental results show that c+FA has maintained the best strength and impermeability whereas c+m obtained less compressive strength, poorer permeability and split tensile strength. c+FA shows a big difference in gaining of compressive strength from 7 days to 28 days compression strength compared to others and this obviously shows the slow rate of hydration of fly ash concrete. As the w/b ratio increases the strength decreases significantly. At the same time higher permeability has been seen in the specimens which were tested for three hours than one hour.Keywords: efficiency factor, cement content, compressive strength, mix proportion, w/c ratio, water permeability, SCMs
Procedia PDF Downloads 2072360 Mechanical Behavior of Corroded RC Beams Strengthened by NSM CFRP Rods
Authors: Belal Almassri, Amjad Kreit, Firas Al Mahmoud, Raoul François
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Corrosion of steel in reinforced concrete leads to several major defects. Firstly, a reduction in the crosssectional area of the reinforcement and in its ductility results in premature bar failure. Secondly, the expansion of the corrosion products causes concrete cracking and steel–concrete bond deterioration and also affects the bending stiffness of the reinforced concrete members, causing a reduction in the overall load-bearing capacity of the reinforced concrete beams. This paper investigates the validity of a repair technique using Near Surface Mounted (NSM) carbon-fibre-reinforced polymer (CFRP) rods to restore the mechanical performance of corrosion-damaged RC beams. In the NSM technique, the CFRP rods are placed inside pre-cut grooves and are bonded to the concrete with epoxy adhesive. Experimental results were obtained on two beams: a corroded beam that had been exposed to natural corrosion for 25 years and a control beam, (both are 3 m long) repaired in bending only. Each beam was repaired with one 6-mm-diameter NSM CFRP rod. The beams were tested in a three-point bending test up to failure. Overall stiffness and crack maps were studied before and after the repair. Ultimate capacity, ductility and failure mode were also reviewed. Finally some comparisons were made between repaired and non-repaired beams in order to assess the effectiveness of the NSM technique. The experimental results showed that the NSM technique improved the overall characteristics (ultimate load capacity and stiffness) of the control and corroded beams and allowed sufficient ductility to be restored to the repaired corroded elements, thus restoring the safety margin, despite the non-classical mode of failure that occurred in the corroded beam, with the separation of the concrete cover due to corrosion products.Keywords: carbon fibre, corrosion, strength, mechanical testing
Procedia PDF Downloads 4472359 Using Large Databases and Interviews to Explore the Temporal Phases of Technology-Based Entrepreneurial Ecosystems
Authors: Elsie L. Echeverri-Carroll
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Entrepreneurial ecosystems have become an important concept to explain the birth and sustainability of technology-based entrepreneurship within regions. However, as a theoretical concept, the temporal evolution of entrepreneurship systems remain underdeveloped, making it difficult to understand their dynamic contributions to entrepreneurs. This paper argues that successful technology-based ecosystems go over three cumulative spawning stages: corporate spawning, entrepreneurial spawning, and community spawning. The importance of corporate incubation in vibrant entrepreneurial ecosystems is well documented in the entrepreneurial literature. Similarly, entrepreneurial spawning processes for venture capital-backed startups are well documented in the financial literature. In contrast, there is little understanding of both the third stage of entrepreneurial spawning (when a community of entrepreneurs become a source of firm spawning) and the temporal sequence in which spawning effects occur in a region. We test this three-stage model of entrepreneurial spawning using data from two large databases on firm births—the Secretary of State (160,000 observations) and the National Establishment Time Series (NEST with 150,000 observations)—and information collected from 60 1½-hour interviews with startup founders and representatives of key entrepreneurial organizations. This temporal model is illustrated with case study of Austin, Texas ranked by the Kauffman Foundation as the number one entrepreneurial city in the United States in 2015 and 2016. The 1½-year study founded by the Kauffman Foundation demonstrates the importance of taken into consideration the temporal contributions of both large and entrepreneurial firms in understanding the factors that contribute to the birth and growth of technology-based entrepreneurial regions. More important, these learnings could offer an important road map for regions that pursue to advance their entrepreneurial ecosystems.Keywords: entrepreneurial ecosystems, entrepreneurial industrial clusters, high-technology, temporal changes
Procedia PDF Downloads 2712358 The Acute Effects of a Warm-Up Including Different Dynamic Stretching on Hamstring Stiffness, Flexibility, and Strength
Authors: Che Hsiu Chen, Kuo Wei Tseng, Zih Jian Huang, Hon Wen Cheng
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A typical warm-up contains both stretching exercises and jogging. The static stretching prior to training or competition may cause detrimental effects to athletic performance. However, it is unclear whether different types of dynamic stretching exercises had different acute effects on knee flexors stiffness, flexibility, and strength. The purpose of this study was to analyze the knee flexors stiffness, flexibility, and strength gains after dynamic straight leg raise (DSLR) and dynamic modified toe-touch (MTT) stretching. Sixteen healthy university active men (height 176.27 ± 4.03 cm; weight 72.27 ± 8.90 kg; age 22.09 ± 2.31 years). After 5 minutes (8km/h) of running subjects performed 2 randomly ordered stretching protocols: DSLR and MTT stretching protocols. There were a total of six, 30 seconds bouts of dynamic stretching (15 repetitions) with 30seconds rest between bouts. The outcome measures were maximal voluntary isokinetic concentric hamstring strength (60°/s), muscle flexibility test by passive straight leg raise (PSLR), active straight leg raise (ASLR), and muscle stiffness using ultrasound Acoustic Radiation Forced Impulse (ARFI) elastography before and immediately after stretching. The muscle stiffness and concentric strength decreased significantly (p < .05), the flexibility no significant change after DSLR protocol (p > .05). The concentric strength decreased significantly (p < .05), the flexibility and muscle stiffness no significant change after MTT protocol (p > .05), whereas no significant differences were found for the DSLR and MTT. Our findings suggest that dynamic stretching (30s x 6 bouts) resulted in change in muscle stiffness or may be induced slack in the musculotendinous unit thereby, reducing force production. Therefore, 30s x 6 bouts of dynamic stretching adversely affects efforts of hamstring muscle maximal concentric strength.Keywords: sport injury, ultrasound, eccentric exercise, performance
Procedia PDF Downloads 2842357 An Effective Modification to Multiscale Elastic Network Model and Its Evaluation Based on Analyses of Protein Dynamics
Authors: Weikang Gong, Chunhua Li
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Dynamics plays an essential role in function exertion of proteins. Elastic network model (ENM), a harmonic potential-based and cost-effective computational method, is a valuable and efficient tool for characterizing the intrinsic dynamical properties encoded in biomacromolecule structures and has been widely used to detect the large-amplitude collective motions of proteins. Gaussian network model (GNM) and anisotropic network model (ANM) are the two often-used ENM models. In recent years, many ENM variants have been proposed. Here, we propose a small but effective modification (denoted as modified mENM) to the multiscale ENM (mENM) where fitting weights of Kirchhoff/Hessian matrixes with the least square method (LSM) is modified since it neglects the details of pairwise interactions. Then we perform its comparisons with the original mENM, traditional ENM, and parameter-free ENM (pfENM) on reproducing dynamical properties for the six representative proteins whose molecular dynamics (MD) trajectories are available in http://mmb.pcb.ub.es/MoDEL/. In the results, for B-factor prediction, mENM achieves the best performance among the four ENM models. Additionally, it is noted that with the weights of the multiscale Kirchhoff/Hessian matrixes modified, interestingly, the modified mGNM/mANM still has a much better performance than the corresponding traditional ENM and pfENM models. As to dynamical cross-correlation map (DCCM) calculation, taking the data obtained from MD trajectories as the standard, mENM performs the worst while the results produced by the modified mENM and pfENM models are close to those from MD trajectories with the latter a little better than the former. Generally, ANMs perform better than the corresponding GNMs except for the mENM. Thus, pfANM and the modified mANM, especially the former, have an excellent performance in dynamical cross-correlation calculation. Compared with GNMs (except for mGNM), the corresponding ANMs can capture quite a number of positive correlations for the residue pairs nearly largest distances apart, which is maybe due to the anisotropy consideration in ANMs. Furtherly, encouragingly the modified mANM displays the best performance in capturing the functional motional modes, followed by pfANM and traditional ANM models, while mANM fails in all the cases. This suggests that the consideration of long-range interactions is critical for ANM models to produce protein functional motions. Based on the analyses, the modified mENM is a promising method in capturing multiple dynamical characteristics encoded in protein structures. This work is helpful for strengthening the understanding of the elastic network model and provides a valuable guide for researchers to utilize the model to explore protein dynamics.Keywords: elastic network model, ENM, multiscale ENM, molecular dynamics, parameter-free ENM, protein structure
Procedia PDF Downloads 1202356 Measurement of Magnetic Properties of Grainoriented Electrical Steels at Low and High Fields Using a Novel Single
Authors: Nkwachukwu Chukwuchekwa, Joy Ulumma Chukwuchekwa
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Magnetic characteristics of grain-oriented electrical steel (GOES) are usually measured at high flux densities suitable for its typical applications in power transformers. There are limited magnetic data at low flux densities which are relevant for the characterization of GOES for applications in metering instrument transformers and low frequency magnetic shielding in magnetic resonance imaging medical scanners. Magnetic properties such as coercivity, B-H loop, AC relative permeability and specific power loss of conventional grain oriented (CGO) and high permeability grain oriented (HGO) electrical steels were measured and compared at high and low flux densities at power magnetising frequency. 40 strips comprising 20 CGO and 20 HGO, 305 mm x 30 mm x 0.27 mm from a supplier were tested. The HGO and CGO strips had average grain sizes of 9 mm and 4 mm respectively. Each strip was singly magnetised under sinusoidal peak flux density from 8.0 mT to 1.5 T at a magnetising frequency of 50 Hz. The novel single sheet tester comprises a personal computer in which LabVIEW version 8.5 from National Instruments (NI) was installed, a NI 4461 data acquisition (DAQ) card, an impedance matching transformer, to match the 600 minimum load impedance of the DAQ card with the 5 to 20 low impedance of the magnetising circuit, and a 4.7 Ω shunt resistor. A double vertical yoke made of GOES which is 290 mm long and 32 mm wide is used. A 500-turn secondary winding, about 80 mm in length, was wound around a plastic former, 270 mm x 40 mm, housing the sample, while a 100-turn primary winding, covering the entire length of the plastic former was wound over the secondary winding. A standard Epstein strip to be tested is placed between the yokes. The magnetising voltage was generated by the LabVIEW program through a voltage output from the DAQ card. The voltage drop across the shunt resistor and the secondary voltage were acquired by the card for calculation of magnetic field strength and flux density respectively. A feedback control system implemented in LabVIEW was used to control the flux density and to make the induced secondary voltage waveforms sinusoidal to have repeatable and comparable measurements. The low noise NI4461 card with 24 bit resolution and a sampling rate of 204.8 KHz and 92 KHz bandwidth were chosen to take the measurements to minimize the influence of thermal noise. In order to reduce environmental noise, the yokes, sample and search coil carrier were placed in a noise shielding chamber. HGO was found to have better magnetic properties at both high and low magnetisation regimes. This is because of the higher grain size of HGO and higher grain-grain misorientation of CGO. HGO is better CGO in both low and high magnetic field applications.Keywords: flux density, electrical steel, LabVIEW, magnetization
Procedia PDF Downloads 2912355 Amblyopia and Eccentric Fixation
Authors: Kristine Kalnica-Dorosenko, Aiga Svede
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Amblyopia or 'lazy eye' is impaired or dim vision without obvious defect or change in the eye. It is often associated with abnormal visual experience, most commonly strabismus, anisometropia or both, and form deprivation. The main task of amblyopia treatment is to ameliorate etiological factors to create a clear retinal image and, to ensure the participation of the amblyopic eye in the visual process. The treatment of amblyopia and eccentric fixation is usually associated with problems in the therapy. Eccentric fixation is present in around 44% of all patients with amblyopia and in 30% of patients with strabismic amblyopia. In Latvia, amblyopia is carefully treated in various clinics, but eccentricity diagnosis is relatively rare. Conflict which has developed relating to the relationship between the visual disorder and the degree of eccentric fixation in amblyopia should to be rethoughted, because it has an important bearing on the cause and treatment of amblyopia, and the role of the eccentric fixation in this case. Visuoscopy is the most frequently used method for determination of eccentric fixation. With traditional visuoscopy, a fixation target is projected onto the patient retina, and the examiner asks to look straight directly at the center of the target. An optometrist then observes the point on the macula used for fixation. This objective test provides clinicians with direct observation of the fixation point of the eye. It requires patients to voluntarily fixate the target and assumes the foveal reflex accurately demarcates the center of the foveal pit. In the end, by having a very simple method to evaluate fixation, it is possible to indirectly evaluate treatment improvement, as eccentric fixation is always associated with reduced visual acuity. So, one may expect that if eccentric fixation in amlyopic eye is found with visuoscopy, then visual acuity should be less than 1.0 (in decimal units). With occlusion or another amblyopia therapy, one would expect both visual acuity and fixation to improve simultaneously, that is fixation would become more central. Consequently, improvement in fixation pattern by treatment is an indirect measurement of improvement of visual acuity. Evaluation of eccentric fixation in the child may be helpful in identifying amblyopia in children prior to measurement of visual acuity. This is very important because the earlier amblyopia is diagnosed – the better the chance of improving visual acuity.Keywords: amblyopia, eccentric fixation, visual acuity, visuoscopy
Procedia PDF Downloads 1572354 Design of Low-Emission Catalytically Stabilized Combustion Chamber Concept
Authors: Annapurna Basavaraju, Andreas Marn, Franz Heitmeir
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The Advisory Council for Aeronautics Research in Europe (ACARE) is cognizant for the overall reduction of NOx emissions by 80% in its vision 2020. Moreover small turbo engines have higher fuel specific emissions compared to large engines due to their limited combustion chamber size. In order to fulfill these requirements, novel combustion concepts are essential. This motivates to carry out the research on the current state of art, catalytic stabilized combustion chamber using hydrogen in small jet engines which are designed and investigated both numerically and experimentally during this project. Catalytic combustion concepts can also be adopted for low caloric fuels and are therefore not constrained to only hydrogen. However, hydrogen has high heating value and has the major advantage of producing only the nitrogen oxides as pollutants during the combustion, thus eliminating the interest on other emissions such as Carbon monoxides etc. In the present work, the combustion chamber is designed based on the ‘Rich catalytic Lean burn’ concept. The experiments are conducted for the characteristic operating range of an existing engine. This engine has been tested successfully at Institute of Thermal Turbomachinery and Machine Dynamics (ITTM), Technical University Graz. One of the facts that the efficient combustion is a result of proper mixing of fuel-air mixture, considerable significance is given to the selection of appropriate mixer. This led to the design of three diverse configurations of mixers and is investigated experimentally and numerically. Subsequently the best mixer would be equipped in the main combustion chamber and used throughout the experimentation. Furthermore, temperatures and pressures would be recorded at various locations inside the combustion chamber and the exhaust emissions will also be analyzed. The instrumented combustion chamber would be inspected at the engine relevant inlet conditions for nine different sets of catalysts at the Hot Flow Test Facility (HFTF) of the institute.Keywords: catalytic combustion, gas turbine, hydrogen, mixer, NOx emissions
Procedia PDF Downloads 3032353 A Study of Teachers’ View on Modern Methods of Teaching Regarding the Quality of Instruction in Shiraz High Schools
Authors: Nasrin Badrkhani
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Teaching is an interaction between the teacher, student, and the concept being taught, especially within the classroom setting. As society increasingly values thoughtful and creative individuals, there is a growing need to adopt modern, active teaching methods. These methods should engage students in activities that foster problem-solving, creativity, cooperation, and scientific thinking skills. Modern teaching methods emphasize student involvement, gradual and continuous learning (process-centered approaches), and holistic evaluation of students' abilities and talents. A shift from teacher-centered to student-centered teaching is crucial. Among these modern methods are group work, role-playing, group discussions, and activities that engage students in evaluating societal values. This research employs a survey and a 38-question Likert scale questionnaire to explore teachers' perspectives on the impact of modern teaching methods on the quality of education. The study also examines the relationship between these perspectives and variables such as gender, major, and teaching experience. The statistical population consists of high school teachers in Shiraz, Iran, with sampling done using the Morgan table. Discriminant analysis was used for the initial analysis of the questions, and Cronbach's Alpha test was employed for the final examination. SPSS Software was used for statistical analysis, including T-tests and one-way ANOVA. The results indicate that teachers in this city generally have positive attitudes towards the use of modern teaching methods, except when it comes to engaging in judgments concerning societal values. There is no significant difference in viewpoints based on gender or educational background. The findings are consistent with similar studies conducted both within Iran and internationally.Keywords: learning, modern methods, student, teacher, teaching
Procedia PDF Downloads 222352 Sentiment Analysis of Fake Health News Using Naive Bayes Classification Models
Authors: Danielle Shackley, Yetunde Folajimi
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As more people turn to the internet seeking health-related information, there is more risk of finding false, inaccurate, or dangerous information. Sentiment analysis is a natural language processing technique that assigns polarity scores to text, ranging from positive, neutral, and negative. In this research, we evaluate the weight of a sentiment analysis feature added to fake health news classification models. The dataset consists of existing reliably labeled health article headlines that were supplemented with health information collected about COVID-19 from social media sources. We started with data preprocessing and tested out various vectorization methods such as Count and TFIDF vectorization. We implemented 3 Naive Bayes classifier models, including Bernoulli, Multinomial, and Complement. To test the weight of the sentiment analysis feature on the dataset, we created benchmark Naive Bayes classification models without sentiment analysis, and those same models were reproduced, and the feature was added. We evaluated using the precision and accuracy scores. The Bernoulli initial model performed with 90% precision and 75.2% accuracy, while the model supplemented with sentiment labels performed with 90.4% precision and stayed constant at 75.2% accuracy. Our results show that the addition of sentiment analysis did not improve model precision by a wide margin; while there was no evidence of improvement in accuracy, we had a 1.9% improvement margin of the precision score with the Complement model. Future expansion of this work could include replicating the experiment process and substituting the Naive Bayes for a deep learning neural network model.Keywords: sentiment analysis, Naive Bayes model, natural language processing, topic analysis, fake health news classification model
Procedia PDF Downloads 962351 Autoimmune Diseases Associated with Primary Biliary Cirrhosis: A Retrospective Study of 51 Patients
Authors: Soumaya Mrabet, Imen Akkari, Amira Atig, Elhem Ben Jazia
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Introduction: Primary biliary cirrhosis (PBC) is a cholestatic cholangitis of unknown etiology. It is frequently associated with autoimmune diseases, which explains their systematic screening. The aim of our study was to determine the prevalence and the type of autoimmune disorders associated with PBC and to assess their impact on the prognosis of the disease. Material and methods: It is a retrospective study over a period of 16 years (2000-2015) including all patients followed for PBC. In all these patients we have systematically researched: dysthyroidism (thyroid balance, antithyroid autoantibodies), type 1 diabetes, dry syndrome (ophthalmologic examination, Schirmer test and lip biopsy in case of Presence of suggestive clinical signs), celiac disease(celiac disease serology and duodenal biopsies) and dermatological involvement (clinical examination). Results: Fifty-one patients (50 women and one men) followed for PBC were collected. The Mean age was 54 years (37-77 years). Among these patients, 30 patients(58.8%) had at least one autoimmune disease associated with PBC. The discovery of these autoimmune diseases preceded the diagnosis of PBC in 8 cases (26.6%) and was concomitant, through systematic screening, in the remaining cases. Autoimmune hepatitis was found in 12 patients (40%), defining thus an overlap syndrome. Other diseases were Hashimoto's thyroiditis (n = 10), dry syndrome (n = 7), Gougerot Sjogren syndrome (n=6), celiac disease (n = 3), insulin-dependent diabetes (n = 1), scleroderma (n = 1), rheumatoid arthritis (n = 1), Biermer Anemia (n=1) and Systemic erythematosus lupus (n=1). The two groups of patients with PBC with or without associated autoimmune disorders were comparable for bilirubin levels, Child-Pugh score, and response to treatment. Conclusion: In our series, the prevalence of autoimmune diseases in PBC was 58.8%. These diseases were dominated by autoimmune hepatitis and Hashimoto's thyroiditis. Even if their association does not seem to alter the prognosis, screening should be systematic in order to institute an early and adequate management.Keywords: autoimmune diseases, autoimmune hepatitis, primary biliary cirrhosis, prognosis
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