Search results for: lower and middle Siwaliks
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 7159

Search results for: lower and middle Siwaliks

5449 Mechanical and Tribological Performances of (Nb: H-D: a-C) Thin Films for Biomedical Applications

Authors: Sara Khamseh, Kambiz Javanruee, Hamid Khorsand

Abstract:

Plenty of metallic materials are used for biomedical applications like hip joints and screws. Besides, it is reported that metal platforms such as stainless steel show significant deterioration because of wear and friction. The surface of metal substrates has been coated with a variety of multicomponent coatings to prevail these problems. The carbon-based multicomponent coatings such as metal-added amorphous carbon and diamond coatings are crucially important because of their remarkable tribological performance and chemical stability. In the current study, H-D contained Nb: (a-C) multicomponent coatings (H-D: hexagonal diamond, a-C: amorphous carbon) coated on A 304 steel substrates using an unbalanced magnetron (UBM) sputtering system. The effects of Nb and H-D content and ID/IG ratio on microstructure, mechanical and tribological characteristics of (Nb: H-D: a-C) composite coatings were investigated. The results of Raman spectroscopy represented that a-C phase with a Graphite-like structure (GLC with high value of sp2 carbon bonding) is formed, and its domain size increased with increasing Nb content of the coatings. Moreover, the Nb played a catalyst for the formation of the H-D phase. The nanoindentation hardness value of the coatings ranged between ~17 to ~35 GPa and (Nb: H-D: a-C) composite coatings with more H-D content represented higher hardness and plasticity index. It seems that the existence of extra-hard H-D particles straightly increased hardness. The tribological performance of the coatings was evaluated using the pin-on-disc method under the wet environment of SBF (Simulated Body Fluid). The COF value of the (Nb: H-D: a-C) coatings decreased with an increasing ID/IG ratio. The lower coefficient of friction is a result of the lamelliform array of graphitic domains. Also, the wear rate of the coatings decreased with increasing H-D content of the coatings. Based on the literature, a-C coatings with high hardness and H3/E2 ratio represent lower wear rates and better tribological performance. According to the nanoindentation analysis, hardness and H3/E2 ratio of (Nb: H-D: a-C) multicomponent coatings increased with increasing H-D content, which in turn decreased the wear rate of the coatings. The mechanical and tribological potency of (Nb: H-D: a-C) composite coatings on A 304 steel substrates paved the way for the development of innovative advanced coatings to ameliorate the performance of A 304 steel for biomedical applications.

Keywords: COF, mechanical properties, (Nb: H-D: a-C) coatings, wear rate

Procedia PDF Downloads 105
5448 Evaluation of Flow Alteration under Climate Change Scenarios for Disaster Risk Management in Lower Mekong Basin: A Case Study in Prek Thnot River in Cambodia

Authors: Vathanachannbo Veth, Ilan Ich, Sophea Rom Phy, Ty Sok, Layheang Song, Sophal Try, Chantha Oeurng

Abstract:

Climate change is one of the major global challenges inducing disaster risks and threatening livelihoods and communities through adverse impacts on food and water security, ecosystems, and services. Prek Thnot River Basin of Cambodia is one of the largest tributaries in the Lower Mekong that has been exposed to hazards and disasters, particularly floods and is said to be the effect of climate change. Therefore, the assessment of precipitation and streamflow changes under the effect of climate change was proposed in this river basin using Soil Water Assessment Tool (SWAT) model and different flow indices under baseline (1997 to 2011) and climate change scenarios (RCP2.6 and RCP8.5 with three General Circulation Models (GCMs): GFDL, GISS, and IPSL) in two time-horizons: near future (the 2030s: 2021 to 2040) and medium future (2060s: 2051 to 2070). Both intensity and frequency indices compared with the historical extreme rainfall indices significantly change in the GFDL under the RCP8.5 for both 2030s and 2060s. The average rate change of Rx1day, Rx10day, SDII, and R20mm in the 2030s and 2060s of both RCP2.6 and RCP8.5 was found to increase in GFDL and decrease in both GISS and IPSL. The mean percentage change of the flow analyzed in the IHA tool (Group1) indicated that the flow in the Prek Thnot River increased in GFDL for both RCP2.6 and RCP8.5 in both 2030s and 2060s, oppositely in GISS, the flow decreases. Moreover, the IPSL affected the flow by increasing in five months (January, February, October, November, and December), and in the other seven months, the flow decreased accordingly. This study provides water resources managers and policymakers with a wide range of precipitation and water flow projections within the Prek Thnot River Basin in the context of plausible climate change scenarios.

Keywords: IHA, climate change, disaster risk, Prek Thnot River Basin, Cambodia

Procedia PDF Downloads 106
5447 Effect of Lowering the Proportion of Chlorella vulgaris in Fish Feed on Tilapia's Immune System

Authors: Hamza A. Pantami, Khozizah Shaari, Intan S. Ismail, Chong C. Min

Abstract:

Introduction: Tilapia is the second-highest harvested freshwater fish species in Malaysia, available in almost all fish farms and markets. Unfortunately, tilapia culture in Malaysia is highly affected by Aeromonas hydrophila and Streptococcus agalactiae, which affect the production rate and consequently pose a direct negative economic impact. Reliance on drugs to control or reduce bacterial infections has been led to contamination of water bodies and development of drug resistance, as well as gave rise to toxicity issues in downstream fish products. Resorting to vaccines have helped curb the problem to a certain extent, but a more effective solution is still required. Using microalgae-based feed to enhance the fish immunity against bacterial infection offers a promising alternative. Objectives: This study aims to evaluate the efficacy of Chlorella vulgaris at lower percentage incorporation in feeds for an immune boost of tilapia in a shorter time. Methods: The study was in two phases. The safety concentration studies at 500 mg/kg-1 and the administration of cultured C. vulgaris biomass via incorporation into fish feed for five different groups in three weeks. Group 1 was the control (0% incorporation), whereas group 2, 3, 4 and 5 received 0.625%, 1.25%, 2.5% and 5% incorporation respectively. The parameters evaluated were the blood profile, serum lysozyme activity (SLA), serum bactericidal activity (SBA), phagocytosis activity (PA), respiratory burst activity (RBA), and lymphoproliferation activity (LPA). The data were analyzed via ANOVA using SPSS (version 16). Further testing was done using Tukey’s test. All tests were performed at the 95% confidence interval (p < 0.05). Results: There were no toxic signs in tilapia fish at 500 mg/kg-1. Treated groups showed significantly better immune parameters compared to the control group (p < 0.05). Conclusions: C. vulgaris crude biomass in a fish meal at a lower incorporation level of 5% can increase specific and non-specific immunity in tilapia fish in a shorter time duration.

Keywords: Chlorella vulgaris, hematology profile, immune boost, lymphoproliferation

Procedia PDF Downloads 111
5446 Application of Flue Gas Recirculation in Fluidized Bed Combustor for Energy Efficiency Enhancement

Authors: Chien-Song Chyang

Abstract:

For a fluidized-bed combustion system, excess air ratio (EAR) and superficial velocity are major operating parameters affecting combustion behaviors, and these 2 factors are dependent variables since both fluidizing gas and combustion-supporting agent are air. EAR will change when superficial velocity alters, so that the effect of superficial velocity and/or EAR on combustion behaviors cannot be examined under a specific condition. When stage combustion is executed, one can discuss the effect of EAR under a certain specific superficial velocity, but the flow rate of secondary air and EAR are dependent. In order to investigate the effect of excess air ratio on the combustion behavior of a fluidized combustion system, the flue gas recirculation was adapted by the author in 2007. We can maintain a fixed flow rate of primary gas or secondary gas and change excess oxygen as an independent variable by adjusting the recirculated flue gas appropriately. In another word, we can investigate the effect of excess oxygen on the combustion behavior at a certain primary gas flow, or at a certain hydrodynamics conditions. This technique can be used at a lower turndown ratio to maintain the residual oxygen in the flue gas at a certain value. All the experiments were conducted in a pilot scale fluidized bed combustor. The fluidized bed combustor can be divided into four parts, i.e., windbox, distributor, combustion chamber, and freeboard. The combustion chamber with a cross-section of 0.8 m × 0.4 m was constructed of 6 mm carbon steel lined with 150 mm refractory to reduce heat loss. Above the combustion chamber, the freeboard is 0.64 m in inner diameter. A total of 27 tuyeres with orifices of 5 and 3 mm inside diameters mounted on a 6 mm stainless-steel plate were used as the gas distributor with an open-area-ratio of 0.52%. The Primary gas and secondary gas were fixed at 3 Nm3/min and 1 Nm3/min respectively. The bed temperature was controlled by three heat transfer tubes inserted into the bubbling bed zone. The experimental data shows that bed temperature, CO and NO emissions increase with the stoichiometric oxygen of the primary gas. NO emissions decrease with the stoichiometric oxygen of the primary. Compared with part of primary air substituted with nitrogen, a lower NO emission can be obtained while flue gas recirculation applies as part of primary air.

Keywords: fluidized bed combustion, flue gas circulation, NO emission, recycle

Procedia PDF Downloads 179
5445 The Characteristics of Static Plantar Loading in the First-Division College Sprint Athletes

Authors: Tong-Hsien Chow

Abstract:

Background: Plantar pressure measurement is an effective method for assessing plantar loading and can be applied to evaluating movement performance of the foot. The purpose of this study is to explore the sprint athletes’ plantar loading characteristics and pain profiles in static standing. Methods: Experiments were undertaken on 80 first-division college sprint athletes and 85 healthy non-sprinters. ‘JC Mat’, the optical plantar pressure measurement was applied to examining the differences between both groups in the arch index (AI), three regional and six distinct sub-regional plantar pressure distributions (PPD), and footprint characteristics. Pain assessment and self-reported health status in sprint athletes were examined for evaluating their common pain areas. Results: Findings from the control group, the males’ AI fell into the normal range. Yet, the females’ AI was classified as the high-arch type. AI values of the sprint group were found to be significantly lower than the control group. PPD were higher at the medial metatarsal bone of both feet and the lateral heel of the right foot in the sprint group, the males in particular, whereas lower at the medial and lateral longitudinal arches of both feet. Footprint characteristics tended to support the results of the AI and PPD, and this reflected the corresponding pressure profiles. For the sprint athletes, the lateral knee joint and biceps femoris were the most common musculoskeletal pains. Conclusions: The sprint athletes’ AI were generally classified as high arches, and that their PPD were categorized between the features of runners and high-arched runners. These findings also correspond to the profiles of patellofemoral pain syndrome (PFPS)-related plantar pressure. The pain profiles appeared to correspond to the symptoms of high-arched runners and PFPS. The findings reflected upon the possible link between high arches and PFPS. The correlation between high-arched runners and PFPS development is worth further studies.

Keywords: sprint athletes, arch index, plantar pressure distributions, high arches, patellofemoral pain syndrome

Procedia PDF Downloads 339
5444 High School Female-Adolescents' Weight Control Practices in Hawassa Town, Ethiopia

Authors: Beruk Berhanu Desalegn, Gelana Mulu

Abstract:

Adolescence, especially for females, is a period of an ongoing risk behavior that triggers development of adverse health outcomes during adulthood. This study aimed to investigate the weight control practice and its associated factors among high school female-adolescents in Hawassa town, Ethiopia. A school-based cross-sectional study was conducted on 552 female-adolescents in Hawassa town. The study was conducted between December, 2020 to January, 2021. SPSS version 26 was used to analyse the data from the pre-tested questionnaire of socio-demographic, economic, socio-cultural, and related information. Among the total female-adolescents, 38.6% [95% CI= 34.5-42.8%] took on weight control practices. The study further revealed the condition of the weight control practice to be healthy (20.5%), unhealthy(25.9%, and the rest to be both healthyand unhealthy(7.8%). The multivariate regression model, cutoff p < 0.05, disclosed that predicters like late adolescent age [AOR=1.98; 95% CI=1.33-2.95], middle wealth status [AOR=2.72; 95% CI=1.60-4.63], high wealth status [AOR=5.69; 95% CI=3.43-9.46], normal BMI [AOR=2.36; 95% CI=1.18-4.71], overweight [AOR=2.45; 95% CI=1.13-5.28], mild depression [AOR=1.72; 95% CI=1.12-2.66] and dissatisfied own mid-torso body image [AOR=2.68; 95% CI=1.52-4.73] were found to have significant association with weight control practice. Therefore, it may be benefiting to consider the findings of this study for interventions associated with female adolescents weight control practices.

Keywords: female-adolescents, highschool, weight control practice, Ethiopia

Procedia PDF Downloads 72
5443 Analyzing Preservice Teachers’ Attitudes toward Technology

Authors: Ahmet Oguz Akturk, Kemal Izci, Gurbuz Caliskan, Ismail Sahin

Abstract:

Rapid developments in technology are to necessitate societies to closely follow technological developments and change themselves to adopt those developments. It is obvious that one of the areas that are impacted from technological developments is education. Analyzing preservice teachers’ attitudes toward technology is crucial for both educational and professional purposes since teacher candidates are essential for educating future individual living in technological age. In this study, it is aimed to analyze preservice teachers’ attitudes toward technology and some variables (e.g., gender, daily internet usage and possessed technological devices) that predicting those attitudes. In this study, relational survey model used as research method and 329 preservice teachers who are studying in a large university located at the middle part of Turkey are voluntarily participated. Results of the study showed that mostly preservice teachers displayed positive attitudes toward technology while male preservice teachers’ attitudes toward technology was more positive than female preservice teachers. In order to analyze predicting factors for preservice teachers’ attitudes toward technology, stepwise multiple regressions were utilized. The results of stepwise multiple regression showed that daily internet use was the most strong predicting factor for predicting preservice teachers’ attitudes toward technology.

Keywords: attitudes toward technology, preservice teachers, gender, stepwise multiple regression analysis

Procedia PDF Downloads 291
5442 Development of Fuzzy Logic Control Ontology for E-Learning

Authors: Muhammad Sollehhuddin A. Jalil, Mohd Ibrahim Shapiai, Rubiyah Yusof

Abstract:

Nowadays, ontology is common in many areas like artificial intelligence, bioinformatics, e-commerce, education and many more. Ontology is one of the focus areas in the field of Information Retrieval. The purpose of an ontology is to describe a conceptual representation of concepts and their relationships within a particular domain. In other words, ontology provides a common vocabulary for anyone who needs to share information in the domain. There are several ontology domains in various fields including engineering and non-engineering knowledge. However, there are only a few available ontology for engineering knowledge. Fuzzy logic as engineering knowledge is still not available as ontology domain. In general, fuzzy logic requires step-by-step guidelines and instructions of lab experiments. In this study, we presented domain ontology for Fuzzy Logic Control (FLC) knowledge. We give Table of Content (ToC) with middle strategy based on the Uschold and King method to develop FLC ontology. The proposed framework is developed using Protégé as the ontology tool. The Protégé’s ontology reasoner, known as the Pellet reasoner is then used to validate the presented framework. The presented framework offers better performance based on consistency and classification parameter index. In general, this ontology can provide a platform to anyone who needs to understand FLC knowledge.

Keywords: engineering knowledge, fuzzy logic control ontology, ontology development, table of content

Procedia PDF Downloads 300
5441 Evaluation of Non-Pharmacological Method-Transcervical Foley Catheter and Misoprostol to Intravaginal Misoprostol for Preinduction Cervical Ripening

Authors: Krishna Dahiya, Esha Charaya

Abstract:

Induction of labour is a common obstetrical intervention. Around 1 in every 4 patient undergo induction of labour for different indications Purpose: To study the efficacy of the combination of Foley bulb and vaginal misoprostol in comparison to vaginal misoprostol alone for cervical ripening and induction of labour. Methods: A prospective randomised study was conducted on 150 patients with term singleton pregnancy admitted for induction of labour. Seventy-five patients were induced with both Foley bulb, and vaginal misoprostol and another 75 were given vaginal misoprostol alone for induction of labour. Both groups were then compared with respect to change in Bishop score, induction to the active phase of labour interval, induction delivery interval, duration of labour, maternal complications and neonatal outcomes. Data was analysed using statistical software SPSS version 11.5. Tests with P,.05 were considered significant. Results: The two groups were comparable with respect to maternal age, parity, gestational age, indication for induction, and initial Bishop scores. Both groups had a significant change in Bishop score (2.99 ± 1.72 and 2.17 ± 1.48 respectively with statistically significant difference (p=0.001 S, 95% C.I. -0.1978 to 0.8378). Mean induction to delivery interval was significantly lower in the combination group (11.76 ± 5.89 hours) than misoprostol group (14.54 ± 7.32 hours). Difference was of 2.78 hours (p=0.018,S, 95% CI -5.1042 to -0.4558). Induction to delivery interval was significantly lower in nulliparous women of combination group (13.64 ± 5.75 hours) than misoprostol group (18.4±7.09 hours), and the difference was of 4.76 hours (p=0.002, S, 95% CI 1.0465 to 14.7335). There was no difference between the groups in the mode of delivery, infant weight, Apgar score and intrapartum complications. Conclusion: From the present study it was concluded that addition of Foley catheter to vaginal misoprostol have the synergistic effect and results in early cervical ripening and delivery. These results suggest that the combination may be used to achieve timely and safe delivery in the presence of an unfavorable cervix. A combination of the Foley bulb and vaginal misoprostol resulted in a shorter induction-to-delivery time when compared with vaginal misoprostol alone without increasing labor complications.

Keywords: Bishop score, Foley catheter, induction of labor, misoprostol

Procedia PDF Downloads 306
5440 Effects of Magnetization Patterns on Characteristics of Permanent Magnet Linear Synchronous Generator for Wave Energy Converter Applications

Authors: Sung-Won Seo, Jang-Young Choi

Abstract:

The rare earth magnets used in synchronous generators offer many advantages, including high efficiency, greatly reduced the size, and weight. The permanent magnet linear synchronous generator (PMLSG) allows for direct drive without the need for a mechanical device. Therefore, the PMLSG is well suited to translational applications, such as wave energy converters and free piston energy converters. This manuscript compares the effects of different magnetization patterns on the characteristics of double-sided PMLSGs in slotless stator structures. The Halbach array has a higher flux density in air-gap than the Vertical array, and the advantages of its performance and efficiency are widely known. To verify the advantage of Halbach array, we apply a finite element method (FEM) and analytical method. In general, a FEM and an analytical method are used in the electromagnetic analysis for determining model characteristics, and the FEM is preferable to magnetic field analysis. However, the FEM is often slow and inflexible. On the other hand, the analytical method requires little time and produces accurate analysis of the magnetic field. Therefore, the flux density in air-gap and the Back-EMF can be obtained by FEM. In addition, the results from the analytical method correspond well with the FEM results. The model of the Halbach array reveals less copper loss than the model of the Vertical array, because of the Halbach array’s high output power density. The model of the Vertical array is lower core loss than the model of Halbach array, because of the lower flux density in air-gap. Therefore, the current density in the Vertical model is higher for identical power output. The completed manuscript will include the magnetic field characteristics and structural features of both models, comparing various results, and specific comparative analysis will be presented for the determination of the best model for application in a wave energy converting system.

Keywords: wave energy converter, permanent magnet linear synchronous generator, finite element method, analytical method

Procedia PDF Downloads 304
5439 Rethinking Flâneur: Strolling Spectators in Harlem in Toni Morrison's Jazz

Authors: Yoonjeogn Kim

Abstract:

The concept of flâneur means a walking observer with subjectivity in the urban city and at the same time, an idiomatic and unnamed existence in public. In the modern city, an individual, flâneur walking on the street, observes the street and collects the memories of the past, during which process the individual comes to understand what the past means. However, the concept tends to be narrowly applied to the white middle-class males, thereby excluding females and other marginalized groups. This paper expands the concept to examine black immigrants and black women, who traditionally fall outside the scope of the flâneur. Placing the black immigrants on the trajectory of literary figure of flâneur by reading Tony Morrison's Jazz, this essay revisits the relationship between street and characters in Jazz. In particular, this essay focuses on characters strolling on the street as well as their surroundings. Based on the traditional characteristics of the flâneur, this essay explicates how the black characters in Jazz are reinvented as the flâneur and moving observers with their autonomy to stroll around the city, while the city, which used to be an observer watching and predicting what happens to the characters, takes a position as a mere onlooker. This paper concludes with illustrating the black characters stroll on the street in Harlem and thereby recreating ordinary people living in Harlem as flâneur.

Keywords: jazz, the arcades project, flâneur, flânerie, street, city

Procedia PDF Downloads 175
5438 Challenges and Opportunities of Intercultural Communication in Afghanistan

Authors: Kefayatullah Wahidi

Abstract:

This article examines the challenges and opportunities of intercultural communication in Afghanistan. Afghanistan, with its ancient history and location on the Silk Road, connects the great civilizations of the world. This country holds a sensitive strategic and geopolitical position in the Middle East. In Afghanistan, various ethnic groups live, each with distinct linguistic, religious, and racial cultures. In today's world, elements such as identity, religion, and culture form the main components of international political relations. In some cases, these factors can even overshadow the materialistic and self-interest-driven aspects of international relations. Therefore, we used a qualitative case study method (using interviews) for this research. In this context, we attempted to discuss the issues and problems related to the challenges and opportunities of intercultural communication, with the participation of a sample of 12 Afghan people. The findings of this research show that Afghanistan is facing many challenges in the field of intercultural communication. Cultural dissatisfaction, linguistic and religious differences, and cultural sanctions are among the major challenges that can cause tensions and a lack of mutual understanding. At the same time, intercultural communication is an opportunity to increase mutual understanding, cultural exchange, and constructive interactions. Please note that I have made some minor edits for clarity and grammar, but the overall content remains the same.

Keywords: cultural dissatisfactions, language differences, intercultural communication, Afghanistan

Procedia PDF Downloads 47
5437 Investigating the Influence of the Ferro Alloys Consumption on the Slab Product Standard Cost with Different Grades Using Regression Analysis (A Case Study of Iran's Iron and Steel Industry)

Authors: Iman Fakhrian, Ali Salehi Manzari

Abstract:

Consistent Profitability is one of the most important priorities in manufacturing companies. One of the fundamental factors for increasing the companies profitability is cost management. Isfahan's mobarakeh steel company is one of the largest producers of the slab product grades in the middle east. Raw material cost constitutes about 70% of the company's expenditures. The costs of the ferro alloys have a remarkable contribution of the raw material costs. This research aims to determine the ferro alloys which have significant effect on the variability of the standard cost of the slab product grades. Used data in this study were collected from standard costing system of isfahan's mobarakeh steel company in 2022. The results of conducting the regression analysis model show that expense items: 03020, 03045, 03125, 03130 and 03150 have dominant role in variability of the standard cost of the slab product grades. In other words, the mentioned ferro alloys have noticeable and significant role in variability of the standard cost of the slab product grades.

Keywords: consistent profitability, ferro alloys, slab product grades, regression analysis

Procedia PDF Downloads 72
5436 Measuring the Effect of Ventilation on Cooking in Indoor Air Quality by Low-Cost Air Sensors

Authors: Andres Gonzalez, Adam Boies, Jacob Swanson, David Kittelson

Abstract:

The concern of the indoor air quality (IAQ) has been increasing due to its risk to human health. The smoking, sweeping, and stove and stovetop use are the activities that have a major contribution to the indoor air pollution. Outdoor air pollution also affects IAQ. The most important factors over IAQ from cooking activities are the materials, fuels, foods, and ventilation. The low-cost, mobile air quality monitoring (LCMAQM) sensors, is reachable technology to assess the IAQ. This is because of the lower cost of LCMAQM compared to conventional instruments. The IAQ was assessed, using LCMAQM, during cooking activities in a University of Minnesota graduate-housing evaluating different ventilation systems. The gases measured are carbon monoxide (CO) and carbon dioxide (CO2). The particles measured are particle matter (PM) 2.5 micrometer (µm) and lung deposited surface area (LDSA). The measurements are being conducted during April 2019 in Como Student Community Cooperative (CSCC) that is a graduate housing at the University of Minnesota. The measurements are conducted using an electric stove for cooking. The amount and type of food and oil using for cooking are the same for each measurement. There are six measurements: two experiments measure air quality without any ventilation, two using an extractor as mechanical ventilation, and two using the extractor and windows open as mechanical and natural ventilation. 3The results of experiments show that natural ventilation is most efficient system to control particles and CO2. The natural ventilation reduces the concentration in 79% for LDSA and 55% for PM2.5, compared to the no ventilation. In the same way, CO2 reduces its concentration in 35%. A well-mixed vessel model was implemented to assess particle the formation and decay rates. Removal rates by the extractor were significantly higher for LDSA, which is dominated by smaller particles, than for PM2.5, but in both cases much lower compared to the natural ventilation. There was significant day to day variation in particle concentrations under nominally identical conditions. This may be related to the fat content of the food. Further research is needed to assess the impact of the fat in food on particle generations.

Keywords: cooking, indoor air quality, low-cost sensor, ventilation

Procedia PDF Downloads 113
5435 Creation of Greater Mekong Subregion Regional Competitiveness through Cluster Mapping

Authors: Danuvasin Charoen

Abstract:

This research investigates cluster development in the area called the Greater Mekong Subregion (GMS), which consists of Thailand, the People’s Republic of China (PRC), the Yunnan Province and Guangxi Zhuang Autonomous Region, Myanmar, the Lao People’s Democratic Republic (Lao PDR), Cambodia, and Vietnam. The study utilized Porter’s competitiveness theory and the cluster mapping approach to analyze the competitiveness of the region. The data collection consists of interviews, focus groups, and the analysis of secondary data. The findings identify some evidence of cluster development in the GMS; however, there is no clear indication of collaboration among the components in the clusters. GMS clusters tend to be stand-alone. The clusters in Vietnam, Lao PDR, Myanmar, and Cambodia tend to be labor intensive, whereas the clusters in Thailand and the PRC (Yunnan) have the potential to successfully develop into innovative clusters. The collaboration and integration among the clusters in the GMS area are promising, though it could take a long time. The most likely relationship between the GMS countries could be, for example, suppliers of the low-end, labor-intensive products will be located in the low income countries such as Myanmar, Lao PDR, and Cambodia, and these countries will be providing input materials for innovative clusters in the middle income countries such as Thailand and the PRC.

Keywords: cluster, GMS, competitiveness, development

Procedia PDF Downloads 263
5434 On the Stability Exact Analysis of Tall Buildings with Outrigger System

Authors: Mahrooz Abed, Amir R. Masoodi

Abstract:

Many structural lateral systems are used in tall buildings such as rigid frames, braced frames, shear walls, tubular structures and core structures. Some efficient structures for drift control and base moment reduction in tall buildings is outrigger and belt truss systems. When adopting outrigger beams in building design, their location should be in an optimum position for an economical design. A range of different strategies has been employed to identify the optimum locations of these outrigger beams under wind load. However, there is an absence of scientific research or case studies dealing with optimum outrigger location using buckling analysis. In this paper, one outrigger system is considered at the middle of height of structure. The optimum location of outrigger will be found based on the buckling load limitation. The core of structure is modeled by a clamped tapered beam. The exact stiffness matrix of tapered beam is formulated based on the Euler-Bernoulli theory. Finally, based on the buckling load of structure, the optimal location of outrigger will be found.

Keywords: tall buildings, outrigger system, buckling load, second-order effects, Euler-Bernoulli beam theory

Procedia PDF Downloads 399
5433 Teaching the Temperature Dependence of Electrical Resistance of Materials through Arduino Investigation

Authors: Vinit Srivastava, Abhay Singh Thakur, Shivam Dubey, Rahul Vaish, Bharat Singh Rajpurohit

Abstract:

This study examines the problem of students' poor comprehension of the thermal dependence of resistance by investigating this idea using an evidence-based inquiry approach. It suggests a practical exercise to improve secondary school students' comprehension of how materials' resistance to temperature changes. The suggested exercise uses an Arduino and Peltier device to test the resistance of aluminum and graphite at various temperatures. The study attempts to close the knowledge gap between the theoretical and practical facets of the subject, which students frequently find difficult to grasp. With the help of a variety of resistors made of various materials and pencils of varying grades, the Arduino experiment investigates the resistance of a metallic conductor (aluminum) and a semiconductor (graphite) at various temperatures. The purpose of the research is to clarify for students the relationship between temperature and resistance and to emphasize the importance of resistor material choice and measurement methods in obtaining precise and stable resistance values over dynamic temperature variations. The findings show that while the resistance of graphite decreases with temperature, the resistance of metallic conductors rises with temperature. The results also show that as softer lead pencils or pencils of a lower quality are used, the resistance values of the resistors drop. In addition, resistors showed greater stability at lower temperatures when their temperature coefficients of resistance (TCR) were smaller. Overall, the results of this article show that the suggested experiment is a useful and practical method for teaching students about resistance's relationship to temperature. It emphasizes how crucial it is to take into account the resistor material selection and the resistance measurement technique when designing and picking out resistors for various uses. The results of the study are anticipated to guide the creation of more efficient teaching methods to close the gap between science education's theoretical and practical components.

Keywords: electrical resistance, temperature dependence, science education, inquiry-based activity, resistor stability

Procedia PDF Downloads 76
5432 The Influence of Ecologically -Valid High- and Low-Volume Resistance Training on Muscle Strength and Size in Trained Men

Authors: Jason Dellatolla, Scott Thomas

Abstract:

Much of the current literature pertaining to resistance training (RT) volume prescription lacks ecological validity, and very few studies investigate true high-volume ranges. Purpose: The present study sought to investigate the effects of ecologically-valid high- vs low-volume RT on muscular size and strength in trained men. Methods: This study systematically randomized trained, college-aged men into two groups: low-volume (LV; n = 4) and high-volume (HV; n = 5). The sample size was affected by COVID-19 limitations. Subjects followed an ecologically-valid 6-week RT program targeting both muscle size and strength. RT occurred 3x/week on non-consecutive days. Over the course of six weeks, LVR and HVR gradually progressed from 15 to 23 sets/week and 30 to 46 sets/week of lower-body RT, respectively. Muscle strength was assessed via 3RM tests in the squat, stiff-leg deadlift (SL DL), and leg press. Muscle hypertrophy was evaluated through a combination of DXA, BodPod, and ultrasound (US) measurements. Results: Two-way repeated-measures ANOVAs indicated that strength in all 3 compound lifts increased significantly among both groups (p < 0.01); between-group differences only occurred in the squat (p = 0.02) and SL DL (p = 0.03), both of which favored HVR. Significant pre-to-post-study increases in indicators of hypertrophy were discovered for lean body mass in the legs via DXA, overall fat-free mass via BodPod, and US measures of muscle thickness (MT) for the rectus femoris, vastus intermedius, vastus medialis, vastus lateralis, long-head of the biceps femoris, and total MT. Between-group differences were only found for MT of the vastus medialis – favoring HVR. Moreover, each additional weekly set of lower-body RT was associated with an average increase in MT of 0.39% in the thigh muscles. Conclusion: We conclude that ecologically-valid RT regimens significantly improve muscular strength and indicators of hypertrophy. When HVR is compared to LVR, HVR provides significantly greater gains in muscular strength but has no greater effect on hypertrophy over the course of 6 weeks in trained, college-aged men.

Keywords: ecological validity, hypertrophy, resistance training, strength

Procedia PDF Downloads 115
5431 Central Vascular Function and Relaxibility in Beta-thalassemia Major Patients vs. Sickle Cell Anemia Patients by Abdominal Aorta and Aortic Root Speckle Tracking Echocardiography

Authors: Gehan Hussein, Hala Agha, Rasha Abdelraof, Marina George, Antoine Fakhri

Abstract:

Background: β-Thalassemia major (TM) and sickle cell disease (SCD) are inherited hemoglobin disorders resulting in chronic hemolytic anemia. Cardiovascular involvement is an important cause of morbidity and mortality in these groups of patients. The narrow border is between overt myocardial dysfunction and clinically silent left ventricular (LV) and / or right ventricular (RV) dysfunction in those patients. 3 D Speckle tracking echocardiography (3D STE) is a novel method for the detection of subclinical myocardial involvement. We aimed to study myocardial affection in SCD and TM using 3D STE, comparing it with conventional echocardiography, correlate it with serum ferritin level and lactate dehydrogenase (LDH). Methodology: Thirty SCD and thirty β TM patients, age range 4-18 years, were compared to 30 healthy age and sex matched control group. Cases were subjected to clinical examination, laboratory measurement of hemoglobin level, serum ferritin, and LDH. Transthoracic color Doppler echocardiography, 3D STE, tissue Doppler echocardiography, and aortic speckle tracking were performed. Results: significant reduction in global longitudinal strain (GLS), global circumferential strain (GCS), and global area strain (GAS) in SCD and TM than control (P value <0.001) there was significantly lower aortic speckle tracking in patients with TM and SCD than control (P value< 0.001). LDH was significantly higher in SCD than both TM and control and it correlated significantly positive mitral inflow E, (p value:0.022 and 0.072. r: 0.416 and -0.333 respectively) lateral E/E’ (p value.<0.001and 0.818. r. 0.618 and -0. 044.respectively) and septal E/E’ (p value 0.007 and 0.753& r value 0.485 and -0.060 respectively) in SCD but not TM and significant negative correlation between LDH and aortic root speckle tracking (value 0.681& r. -0.078.). The potential diagnostic accuracy of LDH in predicting vascular dysfunction as represented by aortic root GCS with a sensitivity 74% and aortic root GCS was predictive of LV dysfunction in SCD patients with sensitivity 100% Conclusion: 3D STE LV and RV systolic dysfunction in spite of their normal values by conventional echocardiography. SCD showed significantly lower right ventricular dysfunction and aortic root GCS than TM and control. LDH can be used to screen patients for cardiac dysfunction in SCD, not in TM

Keywords: thalassemia major, sickle cell disease, 3d speckle tracking echocardiography, LDH

Procedia PDF Downloads 171
5430 Ergonomics Aspects of Work with Computers

Authors: Leena Korpinen, Rauno Pääkkönen, Fabriziomaria Gobba

Abstract:

This paper is based on a large questionnaire study. The paper presents how all participants and subgroups (upper- and lower-level white-collar workers) answered the question, “Have you had an ache, pain, or numbness, which you associate with desktop computer use, in the different body parts during the last 12 months?’ 14.6% of participants (19.4% of women and 8.2% of men) reported that they had often or very often physical symptoms in the neck. Even if our results cannot prove a causal relation of symptoms with computer use, show that workers believe that computer use can influence their wellbeing: This is important when devising treatment modalities to decrease these physical symptoms.

Keywords: ergonomics, work, computer, symptoms

Procedia PDF Downloads 404
5429 Cytology and Flow Cytometry of Three Japanese Drosera Species

Authors: Santhita Tungkajiwangkoon, Yoshikazu Hoshi

Abstract:

Three Japaneses Drosera species are the good model to study genome organization with highly specialized morphological group for insect trapping, and has revealed anti-inflammatory, and antibacterial effects, so there must be a reason for botanists are so appealing in these plants. Cytology and Flow cytometry were used to investigate the genetic stability and ploidy estimation in three related species. The cytological and Flow cytometry analysis were done in Drosera rotundifolia L., Drosera spatulata Labill and Drosera tokaiensis. The cytological studies by fluorescence staining (DAPI) showed that D. tokaiensis was an alloploid (2n=6x=60, hexaploid) which is a natural hybrid polyploids of D. rotundifolia and D. spatulata. D. rotundifolia was a diploid with the middle size of metaphase chromosomes (2n=2x=20) as a paternal origin and D. spatulata was a tetraploid with small size of metaphase chromosome (2n=4x=40) as a maternal origin. We confirmed by Flow cytometry analysis to determine the ploidy level and DNA content of the plants. The 2C-DNA values of D. rotundiflolia were 2.8 pg, D. spatulata was 1.6 pg and D. tokaiensis was 3.9 pg. However, 2C- DNA values of D. tokaiensis should be related from their parents but in the present study the 2C-DNA values of D. tokaiensis was no relation from the theoretical of hybrids representing additive parental. Possibility of D. tokaiensis is a natural hybrid, which is also hybridization in natural evolution can cause the genome reduction in plant.

Keywords: drosera, hybrid, cytology, flow cytometry

Procedia PDF Downloads 384
5428 The Effect of Supplementary Cementitious Materials on Fresh and Hardened Properties of Self-Compacting Concretes

Authors: Akram Salah Eddine Belaidi, Said Kenai, El-Hadj Kadri, Benchaâ Benabed, Hamza Soualhi

Abstract:

Self-compacting concrete (SCC) was developed in the middle of the 1980’s in Japan. SCC flows alone under its dead weight and consolidates itself without any entry of additional compaction energy and without segregation. As an integral part of a SCC, self-compacting mortars (SCM) may serve as a basis for the mix design of concrete since the measurement of the rheological properties of SCCs. This paper discusses the effect of using natural pozzolana (PZ) and marble powder (MP) in two alternative systems ratios PZ/MP = 1 and 1/3 of the performance of the SCC. A total of 11 SCC’s were prepared having a constant water-binder (w/b) ratio of 0.40 and total cementitious materials content of 475 kg/m3. Then, the fresh properties of the mortars were tested for mini-slump flow diameter and mini-V-funnel flow time for SCMs and Slumps flow test, L-Box height ratio, V-Funnel flow time and sieve stability for SCC. Moreover, the development in the compressive strength was determined at 3, 7, 28, 56, and 90 days. Test results have shown that using of ternary blends improved the fresh properties of the mixtures. The compressive strength of SCC at 90 days with 30% of PZ and MP was similar to those of ordinary concrete use in situ.

Keywords: self-compacting mortar, self-compacting concrete, natural pozzolana, marble powder, rheology, compressive strength

Procedia PDF Downloads 376
5427 The Cost-Effectiveness of Pancreatic Surgical Cancer Care in the US vs. the European Union: Results of a Review of the Peer-Reviewed Scientific Literature

Authors: Shannon Hearney, Jeffrey Hoch

Abstract:

While all cancers are costly to treat, pancreatic cancer is a notoriously costly and deadly form of cancer. Across the world there are a variety of treatment centers ranging from small clinics to large, high-volume hospitals as well as differing structures of payment and access. It has been noted that centers that treat a high volume of pancreatic cancer patients have higher quality of care, it is unclear if that care is cost-effective. In the US there is no clear consensus on the cost-effectiveness of high-volume centers for the surgical care of pancreatic cancer. Other European countries, like Finland and Italy have shown that high-volume centers have lower mortality rates and can have lower costs, there however, is still a gap in knowledge about these centers cost-effectiveness globally. This paper seeks to review the current literature in Europe and the US to gain a better understanding of the state of high-volume pancreatic surgical centers cost-effectiveness while considering the contextual differences in health system structure. A review of major reference databases such as Medline, Embase and PubMed will be conducted for cost-effectiveness studies on the surgical treatment of pancreatic cancer at high-volume centers. Possible MeSH terms to be included, but not limited to, are: “pancreatic cancer”, “cost analysis”, “cost-effectiveness”, “economic evaluation”, “pancreatic neoplasms”, “surgical”, “Europe” “socialized medicine”, “privatized medicine”, “for-profit”, and “high-volume”. Studies must also have been available in the English language. This review will encompass European scientific literature, as well as those in the US. Based on our preliminary findings, we anticipate high-volume hospitals to provide better care at greater costs. We anticipate that high-volume hospitals may be cost-effective in different contexts depending on the national structure of a healthcare system. Countries with more centralized and socialized healthcare may yield results that are more cost-effective. High-volume centers may differ in their cost-effectiveness of the surgical care of pancreatic cancer internationally especially when comparing those in the United States to others throughout Europe.

Keywords: cost-effectiveness analysis, economic evaluation, pancreatic cancer, scientific literature review

Procedia PDF Downloads 92
5426 A Shift in Approach from Cereal Based Diet to Dietary Diversity in India: A Case Study of Aligarh District

Authors: Abha Gupta, Deepak K. Mishra

Abstract:

Food security issue in India has surrounded over availability and accessibility of cereal which is regarded as the only food group to check hunger and improve nutrition. Significance of fruits, vegetables, meat and other food products have totally been neglected given the fact that they provide essential nutrients to the body. There is a need to shift the emphasis from cereal-based approach to a more diverse diet so that aim of achieving food security may change from just reducing hunger to an overall health. This paper attempts to analyse how far dietary diversity level has been achieved across different socio-economic groups in India. For this purpose, present paper sets objectives to determine (a) percentage share of different food groups to total food expenditure and consumption by background characteristics (b) source of and preference for all food items and, (c) diversity of diet across socio-economic groups. A cross sectional survey covering 304 households selected through proportional stratified random sampling was conducted in six villages of Aligarh district of Uttar Pradesh, India. Information on amount of food consumed, source of consumption and expenditure on food (74 food items grouped into 10 major food groups) was collected with a recall period of seven days. Per capita per day food consumption/expenditure was calculated through dividing consumption/expenditure by household size and number seven. Food variety score was estimated by giving 0 values to those food groups/items which had not been eaten and 1 to those which had been taken by households in last seven days. Addition of all food group/item score gave result of food variety score. Diversity of diet was computed using Herfindahl-Hirschman index. Findings of the paper show that cereal, milk, roots and tuber food groups contribute a major share in total consumption/expenditure. Consumption of these food groups vary across socio-economic groups whereas fruit, vegetables, meat and other food consumption remain low and same. Estimation of dietary diversity show higher concentration of diet due to higher consumption of cereals, milk, root and tuber products and dietary diversity slightly varies across background groups. Muslims, Scheduled caste, small farmers, lower income class, food insecure, below poverty line and labour families show higher concentration of diet as compared to their counterpart groups. These groups also evince lower mean intake of number of food item in a week due to poor economic constraints and resultant lower accessibility to number of expensive food items. Results advocate to make a shift from cereal based diet to dietary diversity which not only includes cereal and milk products but also nutrition rich food items such as fruits, vegetables, meat and other products. Integrating a dietary diversity approach in food security programmes of the country would help to achieve nutrition security as hidden hunger is widespread among the Indian population.

Keywords: dietary diversity, food Security, India, socio-economic groups

Procedia PDF Downloads 340
5425 Primary and Secondary Big Bangs Theory of Creation of Universe

Authors: Shyam Sunder Gupta

Abstract:

The current theory for the creation of the universe, the Big Bang theory, is widely accepted but leaves some unanswered questions. It does not explain the origin of the singularity or what causes the Big Bang. The theory of the Big Bang also does not explain why there is such a huge amount of dark energy and dark matter in our universe. Also, there is a question related to one universe or multiple universes which needs to be answered. This research addresses these questions using the Bhagvat Puran and other Vedic scriptures as the basis. There is a Unique Pure Energy Field that is eternal, infinite, and finest of all and never transforms when in its original form. The Carrier Particles of Unique Pure Energy are Param-anus- Fundamental Energy Particles. Param-anus and a combination of these particles create bigger particles from which the Universe gets created. For creation to initiate, Unique Pure Energy is represented in three phases: positive phase energy, neutral phase eternal time energy and negative phase energy. Positive phase energy further expands in three forms of creative energies (CE1, CE2andCE3). From CE1 energy, three energy modes, mode of activation, mode of action, and mode of darkness, were created. From these three modes, 16 Principles, subtlest forms of energies, namely Pradhan, Mahat-tattva, Time, Ego, Intellect, Mind, Sound, Space, Touch, Air, Form, Fire, Taste, Water, Smell, and Earth, get created. In the Mahat-tattva, dominant in the Mode of Darkness, CE1 energy creates innumerable primary singularities from seven principles: Pradhan, Mahat-tattva, Ego, Sky, Air, Fire, and Water. CE1 energy gets divided as CE2 and enters, along with three modes and time, in each singularity, and primary Big Bang takes place, and innumerable Invisible Universes get created. Each Universe has seven coverings of 7 principles, and each layer is 10 times thicker than the previous layer. By energy CE2, space in Invisible Universe under the coverings is divided into two halves. In the lower half, the process of evolution gets initiated, and seeds of 24 elements get created, out of which 5 fundamental elements, building blocks of matter, Sky, Air, Fire, Water and Earth, create seeds of stars, planets, galaxies and all other matter. Since 5 fundamental elements get created out of the mode of darkness, it explains why there is so much dark energy and dark matter in our Universe. This process of creation, in the lower half of Invisible universe continues for 2.16 billion years. Further, in the lower part of the energy field, exactly at the Centre of Invisible Universe, Secondary Singularity is created, through which, by force of Mode of Action, Secondary Big Bang takes place and Visible Universe gets created in the shape of Lotus Flower, expanding into upper part. Visible matter starts appearing after a gap of 360,000 years. Within the Visible Universe, a small part gets created known as the Phenomenal Material World, which is our Solar System, the sun being in the Centre. Diameter of Solar planetary system is 6.4 billion km.

Keywords: invisible universe, phenomenal material world, primary Big Bang, secondary Big Bang, singularities, visible universe

Procedia PDF Downloads 91
5424 Rethinking Nigeria's Foreign Policy in the Age of Global Terrorism

Authors: Shuaibu Umar Abdul

Abstract:

This paper examines Nigeria’s foreign policy in the age of global terrorism. It worth saying that the threat of ‘terrorism’ is not peculiar to Western and Middle Eastern countries alone, its tentacles are now spreading all over, Africa inclusive. The issue of domestic terrorism in Nigeria has become pervasive since the return of democratic rule in 1999. This development has never been a witness in any form throughout the year of statehood in Nigeria, the issues of banditry, armed robbery, ritual killing, and criminal activities like kidnapping and pipeline vandalization, the breakdown of law and order, poorly managed infrastructural facilities and corruption remain synonymous to Nigeria. These acts of terrorism no doubt have constituted a challenge that necessitates the paradigm shift in Nigeria’s foreign policy. The study employed the conceptual framework of analysis to lead interrogation; secondary sources were used to generate data while descriptive and content analysis were considered for data presentation and interpretation. In view of the interrogation and discussion on the subject matter, the paper revealed that Nigerian government underrated and underestimated the strength of terrorism within and outside her policy hence, it becomes difficult to address. As a response to the findings and conclusion of the study, the paper recommends among others that Nigeria’s foreign policy has to be rethought, reshaped and remodeled in cognizance to the rising global terrorism for peace, growth and development in the country.

Keywords: foreign policy, globe, Nigeria, rethinking, terrorism

Procedia PDF Downloads 360
5423 A Comparative Study of the Techno-Economic Performance of the Linear Fresnel Reflector Using Direct and Indirect Steam Generation: A Case Study under High Direct Normal Irradiance

Authors: Ahmed Aljudaya, Derek Ingham, Lin Ma, Kevin Hughes, Mohammed Pourkashanian

Abstract:

Researchers, power companies, and state politicians have given concentrated solar power (CSP) much attention due to its capacity to generate large amounts of electricity whereas overcoming the intermittent nature of solar resources. The Linear Fresnel Reflector (LFR) is a well-known CSP technology type for being inexpensive, having a low land use factor, and suffering from low optical efficiency. The LFR was considered a cost-effective alternative option to the Parabolic Trough Collector (PTC) because of its simplistic design, and this often outweighs its lower efficiency. The LFR has been found to be a promising option for directly producing steam to a thermal cycle in order to generate low-cost electricity, but also it has been shown to be promising for indirect steam generation. The purpose of this important analysis is to compare the annual performance of the Direct Steam Generation (DSG) and Indirect Steam Generation (ISG) of LFR power plants using molten salt and other different Heat Transfer Fluids (HTF) to investigate their technical and economic effects. A 50 MWe solar-only system is examined as a case study for both steam production methods in extreme weather conditions. In addition, a parametric analysis is carried out to determine the optimal solar field size that provides the lowest Levelized Cost of Electricity (LCOE) while achieving the highest technical performance. As a result of optimizing the optimum solar field size, the solar multiple (SM) is found to be between 1.2 – 1.5 in order to achieve as low as 9 Cent/KWh for the direct steam generation of the linear Fresnel reflector. In addition, the power plant is capable of producing around 141 GWh annually and up to 36% of the capacity factor, whereas the ISG produces less energy at a higher cost. The optimization results show that the DSG’s performance overcomes the ISG in producing around 3% more annual energy, 2% lower LCOE, and 28% less capital cost.

Keywords: concentrated solar power, levelized cost of electricity, linear Fresnel reflectors, steam generation

Procedia PDF Downloads 111
5422 Evaluation of Medication Administration Process in a Paediatric Ward

Authors: Zayed Alsulami, Asma Aldosseri, Ahmed Ezziden, Abdulrahman Alonazi

Abstract:

Children are more susceptible to medication errors than adults. Medication administration process is the last stage in the medication treatment process and most of the errors detected in this stage. Little research has been undertaken about medication errors in children in the Middle East countries. This study was aimed to evaluate how the paediatric nurses adhere to the medication administration policy and also to identify any medication preparation and administration errors or any risk factors. An observational, prospective study of medication administration process from when the nurses preparing patient medication until administration stage (May to August 2014) was conducted in Saudi Arabia. Twelve paediatric nurses serving 90 paediatric patients were observed. 456 drug administered doses were evaluated. Adherence rate was variable in 7 steps out of 16 steps. Patient allergy information, dose calculation, drug expiry date were the steps in medication administration with lowest adherence rates. 63 medication preparation and administration errors were identified with error rate 13.8% of medication administrations. No potentially life-threating errors were witnessed. Few logistic and administrative factors were reported. The results showed that the medication administration policy and procedure need an urgent revision to be more sensible for nurses in practice. Nurses’ knowledge and skills regarding the medication administration process should be improved.

Keywords: medication sasfety, paediatric, medication errors, paediatric ward

Procedia PDF Downloads 397
5421 Study of Morning-Glory Spillway Structure in Hydraulic Characteristics by CFD Model

Authors: Mostafa Zandi, Ramin Mansouri

Abstract:

Spillways are one of the most important hydraulic structures of dams that provide the stability of the dam and downstream areas at the time of flood. Morning-Glory spillway is one of the common spillways for discharging the overflow water behind dams, these kinds of spillways are constructed in dams with small reservoirs. In this research, the hydraulic flow characteristics of a morning-glory spillways are investigated with CFD model. Two dimensional unsteady RANS equations were solved numerically using Finite Volume Method. The PISO scheme was applied for the velocity-pressure coupling. The mostly used two-equation turbulence models, k- and k-, were chosen to model Reynolds shear stress term. The power law scheme was used for discretization of momentum, k , and  equations. The VOF method (geometrically reconstruction algorithm) was adopted for interface simulation. The results show that the fine computational grid, the input speed condition for the flow input boundary, and the output pressure for the boundaries that are in contact with the air provide the best possible results. Also, the standard wall function is chosen for the effect of the wall function, and the turbulent model k -ε (Standard) has the most consistent results with experimental results. When the jet is getting closer to end of basin, the computational results increase with the numerical results of their differences. The lower profile of the water jet has less sensitivity to the hydraulic jet profile than the hydraulic jet profile. In the pressure test, it was also found that the results show that the numerical values of the pressure in the lower landing number differ greatly in experimental results. The characteristics of the complex flows over a Morning-Glory spillway were studied numerically using a RANS solver. Grid study showed that numerical results of a 57512-node grid had the best agreement with the experimental values. The desired downstream channel length was preferred to be 1.5 meter, and the standard k-ε turbulence model produced the best results in Morning-Glory spillway. The numerical free-surface profiles followed the theoretical equations very well.

Keywords: morning-glory spillway, CFD model, hydraulic characteristics, wall function

Procedia PDF Downloads 77
5420 The Effectiveness of Probiotics in the Treatment of Minimal Hepatic Encephalopathy Among Patients with Cirrhosis: An Expanded Meta-Analysis

Authors: Erwin Geroleo, Higinio Mappala

Abstract:

Introduction Overt Hepatic Encephalopathy (OHE) is the most dreaded outcome of liver cirrhosis. Aside from the triggering factors which are already known to precipitate OHE, there is growing evidence that an altered gut microbiota profile (dysbiosis) can also trigger OHE. MHE is the mildest form of hepatic encephalopathy(HE), affecting about one-third of patients with cirrhosis, and close 80% of patients with cirrhosis and manifests as abnormalities in central nervous system function. Since these symptoms are subclinical most patients are not being treated to prevent OHE. The gut microbiota have been evaluated by several studies as a therapeutic option for MHE, especially in decreasing the levels of ammonia, thus preventing progression to OHE Objectives This study aims to evaluate the efficacy of probiotics in terms of reduction of ammonia levels in patient with minimal hepatic encephalopathies and to determine if Probiotics has role in the prevention of progression to overt hepatic encephalopathy in adult patients with minimal hepatic encephalopathy (MHE) Methods and Analysis The literature search strategy was restricted to human studies in adults subjects from 2004 to 2022. The Jadad Score Calculation was utilized in the assessment of the final studies included in this study. Eight (8) studies were included. Cochrane’s Revman Web, the Fixed Effects model and the Ztest were all used in the overall analysis of the outcomes. A p value of less than 0.0005 was statistically significant. Results. These results show that Probiotics significantly lowers the level of Ammonia in Cirrhotic patients with OHE. It also shows that the use of Probiotics significantly prevents the progression of MHE to OHE. The overall risk of bias graph indicates low risk of publication bias among the studies included in the meta-analysis. Main findings This research found that plasma ammonia concentration was lower among participants treated with probiotics (p<0.00001).) Ammonia level of the probiotics group is lower by 13.96 μmol/ on the average. Overall risk of developing overt hepatic encephalopathy in the probiotics group is shown to be decreased by 15% as compared to the placebo group Conclusion The analysis showed that compared with placebo, probiotics can decrease serum ammonia, may improve MHE and may prevent OHE.

Keywords: minimal hepatic encephalopathy, probiotics, liver cirrhosis, overt hepatic encephalopathy

Procedia PDF Downloads 52