Search results for: effective reproduction number
Commenced in January 2007
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Edition: International
Paper Count: 18417

Search results for: effective reproduction number

17607 Effects of Channel Orientation on Heat Transfer in a Rotating Rectangular Channel with Jet Impingement Cooling and Film Coolant Extraction

Authors: Hua Li, Hongwu Deng

Abstract:

The turbine blade's leading edge is usually cooled by jet impingement cooling technology due to the heaviest heat load. For a rotating turbine blade, however, the channel orientation (β, the angle between the jet direction and the rotating plane) could play an important role in influencing the flow field and heat transfer. Therefore, in this work, the effects of channel orientation (from 90° to 180°) on heat transfer in a jet impingement cooling channel are experimentally investigated. Furthermore, the investigations are conducted under an isothermal boundary condition. Both the jet-to-target surface distance and jet-to-jet spacing are three times the jet hole diameter. The jet Reynolds number is 5,000, and the maximum jet rotation number reaches 0.24. The results show that the rotation-induced variations of heat transfer are different in each channel orientation. In the cases of 90°≤β≤135°, a vortex generated in the low-radius region of the supply channel changes the mass-flowrate distribution in each jet hole. Therefore, the heat transfer in the low-radius region decreases with the rotation number, whereas the heat transfer in the high-radius region increases, indicating that a larger temperature gradient in the radial direction could appear in the turbine blade's leading edge. When 135°<β≤180°; however, the heat transfer of the entire stagnant zone decreases with the rotation number. The rotation-induced jet deflection is the primary factor that weakens the heat transfer, and jets cannot reach the target surface at high rotation numbers. For the downstream regions, however, the heat transfer is enhanced by 50%-80% in every channel orientation because the dead zone is broken by the rotation-induced secondary flow in the impingement channel.

Keywords: heat transfer, jet impingement cooling, channel orientation, high rotation number, isothermal boundary

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17606 Feature Evaluation Based on Random Subspace and Multiple-K Ensemble

Authors: Jaehong Yu, Seoung Bum Kim

Abstract:

Clustering analysis can facilitate the extraction of intrinsic patterns in a dataset and reveal its natural groupings without requiring class information. For effective clustering analysis in high dimensional datasets, unsupervised dimensionality reduction is an important task. Unsupervised dimensionality reduction can generally be achieved by feature extraction or feature selection. In many situations, feature selection methods are more appropriate than feature extraction methods because of their clear interpretation with respect to the original features. The unsupervised feature selection can be categorized as feature subset selection and feature ranking method, and we focused on unsupervised feature ranking methods which evaluate the features based on their importance scores. Recently, several unsupervised feature ranking methods were developed based on ensemble approaches to achieve their higher accuracy and stability. However, most of the ensemble-based feature ranking methods require the true number of clusters. Furthermore, these algorithms evaluate the feature importance depending on the ensemble clustering solution, and they produce undesirable evaluation results if the clustering solutions are inaccurate. To address these limitations, we proposed an ensemble-based feature ranking method with random subspace and multiple-k ensemble (FRRM). The proposed FRRM algorithm evaluates the importance of each feature with the random subspace ensemble, and all evaluation results are combined with the ensemble importance scores. Moreover, FRRM does not require the determination of the true number of clusters in advance through the use of the multiple-k ensemble idea. Experiments on various benchmark datasets were conducted to examine the properties of the proposed FRRM algorithm and to compare its performance with that of existing feature ranking methods. The experimental results demonstrated that the proposed FRRM outperformed the competitors.

Keywords: clustering analysis, multiple-k ensemble, random subspace-based feature evaluation, unsupervised feature ranking

Procedia PDF Downloads 332
17605 Identifying Physiological Markers That Are Sensitive to Cognitive Load in Preschoolers

Authors: Priyashri Kamlesh Sridhar, Suranga Nanayakkara

Abstract:

Current frameworks in assessment follow lesson delivery and rely heavily on test performance or teacher’s observations. This, however, neglects the underlying cognitive load during the learning process. Identifying the pivotal points when the load occurs helps design effective pedagogies and tools that respond to learners’ cognitive state. There has been limited research on quantifying cognitive load in preschoolers, real-time. In this study, we recorded electrodermal activity and heart rate variability (HRV) from 10 kindergarteners performing executive function tasks and Johnson Woodcock test of cognitive abilities. Preliminary findings suggest that there are indeed sensitive task-dependent markers in skin conductance (number of SCRs and average amplitude of SCRs) and HRV (mean heart rate and low frequency component) captured during the learning process.

Keywords: early childhood, learning, methodologies, pedagogies

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17604 Effect of Lifestyle Modification for Two Years on Obesity and Metabolic Syndrome Components in Elementary Students: A Community-Based Trial

Authors: Bita Rabbani, Hossein Chiti, Faranak Sharifi, Saeedeh Mazloomzadeh

Abstract:

Background: Lifestyle modifications, especially improving nutritional patterns and increasing physical activity, are the most important factors in preventing obesity and metabolic syndrome in children and adolescents. For this purpose, the following interventional study was designed to investigate the effects of educational programs for students, as well as changes in diet and physical activity, on obesity and components of the metabolic syndrome. Methods: This study is part of an interventional research project (elementary school) conducted on all students of Sama schools in Zanjan and Abhar in three levels of elementary, middle, and high school, including 1000 individuals in Zanjan (intervention group) and 1000 individuals (control group) in Abhar in 2011. Interventions were based on educating students, teachers, and parents, changes in food services, and physical activity. We primarily measured anthropometric indices, fasting blood sugar, lipid profiles, and blood pressure and completed standard nutrition and physical activity questionnaires. Also, blood insulin levels were randomly measured in a number of students. Data analysis was done by SPSS software version 16.0. Results: Overall, 589 individuals (252 male, 337 female) entered the case group, and 803 individuals (344 male, 459 female) entered the control group. After two years of intervention, mean waist circumference (63.8 ± 10.9) and diastolic BP (63.8 ± 10.4) were significantly lower; however, mean systolic BP (10.1.0 ± 12.5), food score (25.0 ± 5.0) and drinking score (12.1 ± 2.3) were higher in the intervention group (p<0.001). Comparing components of metabolic syndrome between the second year and at time of recruitment within the intervention group showed that although number of overweight/obese individuals, individuals with hypertriglyceridemia and high LDL increased, abdominal obesity, high BP, hyperglycemia, and insulin resistance decreased (p<0.001). On the other hand, in the control group, number of individuals with high BP increased significantly. Conclusion: The prevalence of abdominal obesity and hypertension, which are two major components of metabolic syndrome, are much higher in our study than in other regions of country. However, interventions for modification of diet and increase in physical activity are effective in lowering their prevalence.

Keywords: metabolic syndrome, obesity, life style, nutrition, hypertension

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17603 Public Relations Challenges in Georgia: Marketing Communications and Strategies

Authors: Marine Kobalava

Abstract:

Modern forms of public relations function in an integrated manner together with marketing communication in business companies. This ensures continuity of communication, elimination of duplication in activities, reduction of costs, and strengthening and efficient use of communication means. There exist a number of challenges in implementing integrated forms of public relations in Georgia, especially in terms of marketing communications and strategies. Objectives: The goal of the study is to reveal public relations challenges in Georgian business companies and to develop recommendations along with perfecting marketing communications and strategies. Methodologies: Bibliographic and empirical research has been conducted. Analysis, induction, synthesis, and other methods have been used. Contributions: The challenges of Public relations in Georgia are identified; the perception of different population groups on integrated forms of PR is determined; effective forms of marketing communication are defined; mechanisms for developing marketing strategies are proposed.

Keywords: public relations, challenges, marketing communication, strategy

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17602 Numerical Solution of Steady Magnetohydrodynamic Boundary Layer Flow Due to Gyrotactic Microorganism for Williamson Nanofluid over Stretched Surface in the Presence of Exponential Internal Heat Generation

Authors: M. A. Talha, M. Osman Gani, M. Ferdows

Abstract:

This paper focuses on the study of two dimensional magnetohydrodynamic (MHD) steady incompressible viscous Williamson nanofluid with exponential internal heat generation containing gyrotactic microorganism over a stretching sheet. The governing equations and auxiliary conditions are reduced to a set of non-linear coupled differential equations with the appropriate boundary conditions using similarity transformation. The transformed equations are solved numerically through spectral relaxation method. The influences of various parameters such as Williamson parameter γ, power constant λ, Prandtl number Pr, magnetic field parameter M, Peclet number Pe, Lewis number Le, Bioconvection Lewis number Lb, Brownian motion parameter Nb, thermophoresis parameter Nt, and bioconvection constant σ are studied to obtain the momentum, heat, mass and microorganism distributions. Moment, heat, mass and gyrotactic microorganism profiles are explored through graphs and tables. We computed the heat transfer rate, mass flux rate and the density number of the motile microorganism near the surface. Our numerical results are in better agreement in comparison with existing calculations. The Residual error of our obtained solutions is determined in order to see the convergence rate against iteration. Faster convergence is achieved when internal heat generation is absent. The effect of magnetic parameter M decreases the momentum boundary layer thickness but increases the thermal boundary layer thickness. It is apparent that bioconvection Lewis number and bioconvection parameter has a pronounced effect on microorganism boundary. Increasing brownian motion parameter and Lewis number decreases the thermal boundary layer. Furthermore, magnetic field parameter and thermophoresis parameter has an induced effect on concentration profiles.

Keywords: convection flow, similarity, numerical analysis, spectral method, Williamson nanofluid, internal heat generation

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17601 Information Technology Governance Implementation and Its Determinants in the Egyptian Market

Authors: Nariman O. Kandil, Ehab K. Abou-Elkheir, Amr M. Kotb

Abstract:

Effective IT governance guarantees the strategic alignment of IT and business goals, risk mitigation control, and better IT and business performance. This study seeks to examine empirically the extent of IT governance implementation within the firms listed on the Egyptian stock exchange (EGX30) and its determinants. Accordingly, 18 semi-structured interviews face to face, phone, and video-conferencing interviews using various tools (e.g., WebEx, Zoom, and Microsoft Teams) were undertaken at the interviewees’ offices in Egypt between the end of November 2019 and the end of August 2020. Results suggest that there are variances in the extent of IT Governance (ITG) implementation within the firms listed on the Egyptian stock exchange (EGX30), mainly caused by the industry type and internal and external triggers. The results also suggest that the organization size, the type of auditor, the criticality of the industry, the effective processes & KPIs, and the information intensity expertise of the CIO have a significant impact on IT governance implementation within the firms.

Keywords: effective IT governance, Egyptian market, information security, risk controls

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17600 Analysing Environmental Licensing of Infrastructure Projects in Brazil

Authors: Ronaldo Seroa Da Motta, Gabriela Santiago

Abstract:

The main contribution of this study is the identification of the factors influencing the environmental licensing process of infrastructure projects in Brazil. These factors will be those that reflect the technical characteristics of the project, the corporate governance of the entrepreneur, and the institutional and regulatory governance of the environmental agency, including the number of interventions by non-licensing agencies. The model conditions these variables to the licensing processing time of 34 infrastructure projects. Our results indicated that the conditions would be more sensitive to the type of enterprise, complexity as in gas pipelines and hydroelectric plants in the most vulnerable biome with a greater value of the enterprise or the entrepreneur's assets, together with the number of employees of the licensing agency. The number of external interventions by other non-licensing institutions does not affect the licensing time. Such results challenge the current criticism that environmental licensing has been often pointed out as a barrier to speed up investments in infrastructure projects in Brazil due to the participation of civil society and other non-licensing institutions.

Keywords: environmental licensing, condionants, Brazil, timing process

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17599 Improvement of Mechanical Properties of Saline Soils by Fly Ash: Effect of Freeze-Thaw Cycles

Authors: Zhuo Cheng, Gaohang Cui, Yang Zheng, Zhiqiang-Pan

Abstract:

To explore the effect of freeze-thaw cycles on saline soil mechanical properties of fly ash, this study examined the influence of different numbers of freezing and thawing cycles, fly ash content, and moisture content of saline soil in unconfined compression tests and triaxial shear tests. With increased fly ash content, the internal friction angle, cohesion, unconfined compressive strength, and shear strength of the improved soil increased at first and then decreased. Using the Desk-Expert 8.0 software and based on significance analysis theory, the number of freeze-thaw cycles, fly ash content, water content, and the interactions between various factors on the mechanical properties of saline soil were studied. The results showed that the number of freeze-thaw cycles had a significant effect on the mechanical properties of saline soil, while the fly ash content had a weakly significant effect. At the same time, interaction between the number of freeze-thaw cycles and the water content had a significant effect on the unconfined compressive strength and the cohesion of saline soil, and the interaction between fly ash content and the number of freeze-thaw cycles only had a significant effect on the unconfined compressive strength.

Keywords: fly ash, saline soil, seasonally frozen area, significance analysis, qualitative analysis

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17598 Lactic Acid, Citric Acid, and Potassium Bitartrate Non-Hormonal Prescription Vaginal PH Modulator Gel for the Prevention of Pregnancy

Authors: Shanna Su, Kathleen Vincent

Abstract:

Introduction: A non-hormonal prescription vaginal pH modulator (VPM) gel (Phexxi®), with active ingredients lactic acid, citric acid, and potassium bitartrate, has recently been approved for the prevention of pregnancy in the United States. The objective of this review is to compile the evidence available from published preclinical and clinical trials to support its use. Areas covered: PubMed was searched for published literature on VPM gel. Two Phase III trials were found on the clinicaltrials.gov database. The results demonstrated that VPM gel is safe, with minimal side effects, and effective (cumulative 6-7 cycle pregnancy rate of 4.1-13.65%, (Pearl Index 27.5) as a contraceptive. Microbicidal effects suggest the potential for the prevention of sexually transmitted infections (STIs); currently, a Phase III clinical trial is being conducted to evaluate the prevention of chlamydia and gonorrhea. Expert opinion: Non-hormonal reversible contraceptive options have been limited to the highly effective copper-releasing intrauterine device that requires insertion by a trained clinician and less effective coitally-associated barrier and spermicide options which are typically available over-the-counter. Spermicides, which improve the efficacy of barrier devices, may increase the risk of Human Immunodeficiency Virus (HIV)/STIs. VPM gel provides a new safe, effective non-hormonal contraceptive option with the potential for prevention of STIs.

Keywords: citric acid, lactic acid, non-hormonal contraception, potassium bitartrate, topical vaginal contraceptive, vaginal pH modulator gel

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17597 Prospective Cohort Study on Sequential Use of Catheter with Misoprostol vs Misoprostol Alone for Second Trimester Medical Abortion

Authors: Hanna Teklu Gebregziabher

Abstract:

Background: A variety of techniques for medical termination of second-trimester pregnancy can be used, but there is no consensus about which is the best. Even though most evidence suggests the combined use of intracervical Foley catheter and vaginal misoprostol is safe, effective, and acceptable method for termination of second-trimester pregnancy, which is comparable to mifepristone-misoprostol combination regimen with lower cost and no additional maternal risks. The use of mifepristone and misoprostol alone with no other procedure is still the most common procedure in different institutions for 2nd-trimester pregnancy. Methods: A cross-sectional comparative prospective study design is employed on women who were admitted for 2nd-trimester medical abortion and medical abortion failed or if there was no change in cervical status after 24 hours of 1st dose of misoprostol. The study was conducted at St. Paulose Hospital Millennium Medical College. A sample of 44 participants in each arm was necessary to give a two-tailed test, a type 1 error of 5%, 80% statistical power, and a 1:1 ratio among groups. Thus, a total of 94 cases, 47 from each arm, were recruited. Data was entered and cleaned by using Epi-info and analyzed using SPSS version 29.0 statistical software and was presented in descriptive and tabular forms. Different variables were cross-tabulated and compared for significant differences and statistical analysis using the chi-square test and independent t-test, to conclude. Result: There was a significant difference between the two groups on induction to expulsion time and number of doses used. The mean ± SD of induction to expulsion time for those used misoprostol alone was 48.09 ± 11.86 and those who used trans-cervical catheter sequentially with misoprostol were 36.7 ±6.772. Conclusion: The use of a trans-cervical Foley catheter in conjunction with misoprostol in a sequential manner is a more effective, safe, and easily accessible procedure. In addition, the cost of utilizing the catheter is less compared to the cost of misoprostol and is readily available. As a good substitute, we advised using Trans-cervical Catether even for medical abortions performed in the second trimester.

Keywords: second trimester, medical abortion, catheter, misoprostol

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17596 Evaluation of the Risk Factors on the Incidence of Adjacent Segment Degeneration After Anterior Neck Discectomy and Fusion

Authors: Sayyed Mostafa Ahmadi, Neda Raeesi

Abstract:

Background and Objectives: Cervical spondylosis is a common problem that affects the adult spine and is the most common cause of radiculopathy and myelopathy in older patients. Anterior discectomy and fusion is a well-known technique in degenerative cervical disc disease. However, one of the late undesirable complications is adjacent disc degeneration, which affects about 91% of patients in ten years. Many factors can be effective in causing this complication, but some are still debatable. Discovering these risk factors and eliminating them can improve the quality of life. Methods: This is a retrospective cohort study. All patients who underwent anterior discectomy and fusion surgery in the neurosurgery ward of Imam Khomeini Hospital between 2013 and 2016 were evaluated. Their demographic information was collected. All patients were visited and examined for radiculopathy, myelopathy, and muscular force. At the same visit, all patients were asked to have a facelift, and neck profile, as well as a neck MRI(General Tesla 3). Preoperative graphs were used to measure the diameter of the cervical canal(Pavlov ratio) and to evaluate sagittal alignment(Cobb Angle). Preoperative MRI of patients was reviewed for anterior and posterior longitudinal ligament calcification. Result: In this study, 57 patients were studied. The mean age of patients was 50.63 years, and 49.1% were male. Only 3.5% of patients had anterior and posterior longitudinal ligament calcification. Symptomatic ASD was observed in 26.6%. The X-rays and MRIs showed evidence of 80.7% radiological ASD. Among patients who underwent one-level surgery, 20% had symptomatic ASD, but among patients who underwent two-level surgery, the rate of ASD was 50%.In other words, the higher the number of surfaces that are operated and fused, the higher the probability of symptomatic ASD(P-value <0.05). The X-rays and MRIs showed 80.7% of radiological ASD. Among patients who underwent surgery at one level, 78% had radiological ASD, and this number was 92% among patients who underwent two-level surgery(P-value> 0.05). Demographic variables such as age, sex, height, weight, and BMI did not have a significant effect on the incidence of radiological ASD(P-value> 0.05), but sex and height were two influential factors on symptomatic ASD(P-value <0.05). Other related variables such as family history, smoking and exercise also have no significant effect(P-value> 0.05). Radiographic variables such as Pavlov ratio and sagittal alignment were also unaffected by the incidence of radiological and symptomatic ASD(P-value> 0.05). The number of surgical surfaces and the incidence of anterior and posterior longitudinal ligament calcification before surgery also had no statistically significant effect(P-value> 0.05). In the study of the ability of the neck to move in different directions, none of these variables are statistically significant in the two groups with radiological and symptomatic ASD and the non-affected group(P-value> 0.05). Conclusion: According to the findings of this study, this disease is considered to be a multifactorial disease. The incidence of radiological ASD is much higher than symptomatic ASD (80.7% vs. 26.3%) and sex, height and number of fused surfaces are the only factors influencing the incidence of symptomatic ASD and no variable influences radiological ASD.

Keywords: risk factors, anterior neck disectomy and fusion, adjucent segment degeneration, complication

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17595 Strategic Maintenance Management of Built Facilities in an Organisation

Authors: Anita D. Adamu, Winston M. W. Shakantu

Abstract:

Maintenance management is no longer a stand-alone activity. It has now assumed a strategic position in many organisations that have recognised its importance in achieving primary goals and a key aspect of effective management of facilities. This paper aims at providing an understanding of the role and function of strategic management in creating and sustaining an effective maintenance management system in an organisation. The background provides an articulated concept and principles of strategic management. The theoretical concepts paved way for a conceptual framework for which strategic management can be integrated into the maintenance management system of an organisation to improve effectiveness in the maintenance of facilities.

Keywords: facilities, maintenance management, organisations, strategic management

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17594 Proposing Problem-Based Learning as an Effective Pedagogical Technique for Social Work Education

Authors: Christine K. Fulmer

Abstract:

Social work education is competency based in nature. There is an expectation that graduates of social work programs throughout the world are to be prepared to practice at a level of competence, which is beneficial to both the well-being of individuals and community. Experiential learning is one way to prepare students for competent practice. The use of Problem-Based Learning (PBL) is a form experiential education that has been successful in a number of disciplines to bridge the gap between the theoretical concepts in the classroom to the real world. PBL aligns with the constructivist theoretical approach to learning, which emphasizes the integration of new knowledge with the beliefs students already hold. In addition, the basic tenants of PBL correspond well with the practice behaviors associated with social work practice including multi-disciplinary collaboration and critical thinking. This paper makes an argument for utilizing PBL in social work education.

Keywords: social work education, problem-based learning, pedagogy, experiential learning, constructivist theoretical approach

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17593 Determination of Some Agricultural Characters of Developed Pea (Pisum sativum L.) Lines

Authors: Ercan Ceyhan, Mehmet Ali Avci

Abstract:

This research was made during the 2015 growing periods in the trial filed of ‘Research Station for Department of Field Crops, Agricultural Faculty, Selcuk University’ according to ‘Randomized Blocks Design’ with 3 replications. Research material was the following pea lines; PS16, PS18, PS21, PS23, PS24, PS25, PS36, PS47, PS49, PS51, PS54, PS58, PS67, PS69, PS71, PS73, PS83, PS84, PS87 and PSKY and three cultivars and other 2 commercial varieties named as Bolero, Rondo and Ultrello. Some agronomical characteristics such as plant height (cm) number of pod per plant number of seed per pod number of seed per plant 100 seed weight (g) and seed yield (kg ha-1) were determined. Results of the research implicated that the new developed lines were superior compared with the control (commercial) varieties by means of most of the characteristics. Nevertheless, similar researches should be continued in different locations and years.

Keywords: agricultural characters, pea, Pisum sativum, seed yield

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17592 A Proof for Goldbach's Conjecture

Authors: Hashem Sazegar

Abstract:

In 1937, Vinograd of Russian Mathematician proved that each odd large number can be shown by three primes. In 1973, Chen Jingrun proved that each odd number can be shown by one prime plus a number that has maximum two primes. In this article, we state one proof for Goldbach’conjecture. Introduction: Bertrand’s postulate state for every positive integer n, there is always at least one prime p, such that n < p < 2n. This was first proved by Chebyshev in 1850, which is why postulate is also called the Bertrand-Chebyshev theorem. Legendre’s conjecture states that there is a prime between n2 and (n+1)2 for every positive integer n, which is one of the four Landau’s problems. The rest of these four basic problems are; (i) Twin prime conjecture: There are infinitely many primes p such that p+2 is a prime. (ii) Goldbach’s conjecture: Every even integer n > 2 can be written asthe sum of two primes. (iii) Are there infinitely many primes p such that p−1 is a perfect square? Problems (i), (ii), and (iii) are open till date.

Keywords: Bertrand-Chebyshev theorem, Landau’s problems, twin prime, Legendre’s conjecture, Oppermann’s conjecture

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17591 Study on the Effects of Geometrical Parameters of Helical Fins on Heat Transfer Enhancement of Finned Tube Heat Exchangers

Authors: H. Asadi, H. Naderan Tahan

Abstract:

The aim of this paper is to investigate the effect of geometrical properties of helical fins in double pipe heat exchangers. On the other hand, the purpose of this project is to derive the hydraulic and thermal design tables and equations of double heat exchangers with helical fins. The numerical modeling is implemented to calculate the considered parameters. Design tables and correlated equations are generated by repeating the parametric numerical procedure for different fin geometries. Friction factor coefficient and Nusselt number are calculated for different amounts of Reynolds, fluid Prantle and fin twist angles for the range of laminar fluid flow in annular tube with helical fins. Results showed that friction factor coefficient and Nusselt number will be increased for higher Reynolds numbers and fins’ twist angles in general. These two parameters follow different patterns in response to Reynolds number increment. Thermal performance factor is defined to analyze these different patterns. Temperature and velocity contours are plotted against twist angle and number of fins to describe the changes in flow patterns in different geometries of twisted finned annulus. Finally twisted finned annulus friction factor coefficient, Nusselt Number and thermal performance factor are correlated by simulating the model in different design points.

Keywords: double pipe heat exchangers, heat exchanger performance, twisted fins, computational fluid dynamics

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17590 Design and Development of High Strength Aluminium Alloy from Recycled 7xxx-Series Material Using Bayesian Optimisation

Authors: Alireza Vahid, Santu Rana, Sunil Gupta, Pratibha Vellanki, Svetha Venkatesh, Thomas Dorin

Abstract:

Aluminum is the preferred material for lightweight applications and its alloys are constantly improving. The high strength 7xxx alloys have been extensively used for structural components in aerospace and automobile industries for the past 50 years. In the next decade, a great number of airplanes will be retired, providing an obvious source of valuable used metals and great demand for cost-effective methods to re-use these alloys. The design of proper aerospace alloys is primarily based on optimizing strength and ductility, both of which can be improved by controlling the additional alloying elements as well as heat treatment conditions. In this project, we explore the design of high-performance alloys with 7xxx as a base material. These designed alloys have to be optimized and improved to compare with modern 7xxx-series alloys and to remain competitive for aircraft manufacturing. Aerospace alloys are extremely complex with multiple alloying elements and numerous processing steps making optimization often intensive and costly. In the present study, we used Bayesian optimization algorithm, a well-known adaptive design strategy, to optimize this multi-variable system. An Al alloy was proposed and the relevant heat treatment schedules were optimized, using the tensile yield strength as the output to maximize. The designed alloy has a maximum yield strength and ultimate tensile strength of more than 730 and 760 MPa, respectively, and is thus comparable to the modern high strength 7xxx-series alloys. The microstructure of this alloy is characterized by electron microscopy, indicating that the increased strength of the alloy is due to the presence of a high number density of refined precipitates.

Keywords: aluminum alloys, Bayesian optimization, heat treatment, tensile properties

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17589 Targeting Trypanosoma brucei Using Antibody Drug Conjugates against the Transferrin Receptor

Authors: Camilla Trevor, Matthew K. Higgins, Andrea Gonzalez-Munoz, Mark Carrington

Abstract:

Trypanosomiasis is a devastating disease affecting both humans and livestock in sub-Saharan Africa. The diseases are caused by infection with African trypanosomes, protozoa transmitted by tsetse flies. Treatment currently relies on the use of chemotherapeutics with ghastly side effects. Here, we describe the development of effective antibody-drug conjugates that target the T. brucei transferrin receptor. The receptor is essential for trypanosome growth in a mammalian host but there are approximately 12 variants of the transferrin receptor in the genome. Two of the most divergent variants were used to generate recombinant monoclonal immunoglobulin G using phage display and we identified cross-reactive antibodies that bind both variants using phage ELISA, fluorescence resonance energy transfer assays and surface plasmon resonance. Fluorescent antibodies were used to demonstrate uptake into trypanosomes in culture. Toxin-conjugated antibodies were effective at killing trypanosomes at sub-nanomolar concentrations. The approach of using antibody-drug conjugates has proven highly effective.

Keywords: antibody-drug conjugates, phage display, transferrin receptor, trypanosomes

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17588 A Greener Approach towards the Synthesis of an Antimalarial Drug Lumefantrine

Authors: Luphumlo Ncanywa, Paul Watts

Abstract:

Malaria is a disease that kills approximately one million people annually. Children and pregnant women in sub-Saharan Africa lost their lives due to malaria. Malaria continues to be one of the major causes of death, especially in poor countries in Africa. Decrease the burden of malaria and save lives is very essential. There is a major concern about malaria parasites being able to develop resistance towards antimalarial drugs. People are still dying due to lack of medicine affordability in less well-off countries in the world. If more people could receive treatment by reducing the cost of drugs, the number of deaths in Africa could be massively reduced. There is a shortage of pharmaceutical manufacturing capability within many of the countries in Africa. However one has to question how Africa would actually manufacture drugs, active pharmaceutical ingredients or medicines developed within these research programs. It is quite likely that such manufacturing would be outsourced overseas, hence increasing the cost of production and potentially limiting the full benefit of the original research. As a result the last few years has seen major interest in developing more effective and cheaper technology for manufacturing generic pharmaceutical products. Micro-reactor technology (MRT) is an emerging technique that enables those working in research and development to rapidly screen reactions utilizing continuous flow, leading to the identification of reaction conditions that are suitable for usage at a production level. This emerging technique will be used to develop antimalarial drugs. It is this system flexibility that has the potential to reduce both the time was taken and risk associated with transferring reaction methodology from research to production. Using an approach referred to as scale-out or numbering up, a reaction is first optimized within the laboratory using a single micro-reactor, and in order to increase production volume, the number of reactors employed is simply increased. The overall aim of this research project is to develop and optimize synthetic process of antimalarial drugs in the continuous processing. This will provide a step change in pharmaceutical manufacturing technology that will increase the availability and affordability of antimalarial drugs on a worldwide scale, with a particular emphasis on Africa in the first instance. The research will determine the best chemistry and technology to define the lowest cost manufacturing route to pharmaceutical products. We are currently developing a method to synthesize Lumefantrine in continuous flow using batch process as bench mark. Lumefantrine is a dichlorobenzylidine derivative effective for the treatment of various types of malaria. Lumefantrine is an antimalarial drug used with artemether for the treatment of uncomplicated malaria. The results obtained when synthesizing Lumefantrine in a batch process are transferred into a continuous flow process in order to develop an even better and reproducible process. Therefore, development of an appropriate synthetic route for Lumefantrine is significant in pharmaceutical industry. Consequently, if better (and cheaper) manufacturing routes to antimalarial drugs could be developed and implemented where needed, it is far more likely to enable antimalarial drugs to be available to those in need.

Keywords: antimalarial, flow, lumefantrine, synthesis

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17587 Scheduling Tasks in Embedded Systems Based on NoC Architecture

Authors: D. Dorota

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This paper presents a method to generate and schedule task in the architecture of embedded systems based on the simulated annealing. This method takes into account the attribute of divisibility of tasks. A proposal represents the process in the form of trees. Despite the fact that the architecture of Network-on-Chip (NoC) is an interesting alternative to a bus architecture based on multi-processors systems, it requires a lot of work that ensures the optimization of communication. This paper proposes an effective approach to generate dedicated NoC topology solving communication problems. Network NoC is generated taking into account the energy consumption and resource issues. Ultimately generated is minimal, dedicated NoC topology. The proposed solution is assumed to be a simple router design and the minimum number of lines.

Keywords: Network-on-Chip, NoC-based embedded systems, scheduling task in embedded systems, simulated annealing

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17586 Designing Effective Serious Games for Learning and Conceptualization Their Structure

Authors: Zahara Abdulhussan Al-Awadai

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Currently, serious games play a significant role in education, sparking an increasing interest in using games for purposes beyond mere entertainment. In this research, we investigate the main requirements and aspects of designing and developing effective serious games for learning and developing a conceptual model to describe the structure of serious games with a focus on both aspects of serious games. The main contributions of this approach are to facilitate the design and development of serious games in a flexible and easy-to-use way and also to support the cooperative work between the multidisciplinary developer team.

Keywords: game development, game design, requirements, serious games, serious game model.

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17585 Climate Impact-Minimizing Road Infrastructure Layout for Growing Cities

Authors: Stanislovas Buteliauskas, Aušrius Juozapavičius

Abstract:

City road transport contributes significantly to climate change, and the ongoing world urbanization is only increasing the problem. The paper describes a city planning concept minimizing the number of vehicles on the roads while increasing overall mobility. This becomes possible by utilizing a recently invented two-level road junction with a unique property of serving both as an intersection of uninterrupted traffic and an easily accessible transport hub capable of accumulating private vehicles, and therefore becoming an especially effective park-and-ride solution, and a logistics or business center. Optimized layouts of city road infrastructure, living and work areas, and major roads are presented. The layouts are suitable both for the development of new cities as well as for the expansion of existing ones. Costs of the infrastructure and a positive impact on climate are evaluated in comparison to current city growth patterns.

Keywords: congestion, city infrastructure, park-and-ride, road junctions

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17584 Investigating the Potential of a Blended Format for the Academic Reading Module Course Redesign

Authors: Reham Niazi, Marwa Helmy, Susanne Rizzo

Abstract:

This classroom action research is designed to explore the possibility of adding effective online content to supplement and add learning value to the current reading module. The aim of this research was two-fold, first to investigate students’ acceptance of and interactivity with online components, chosen to orient students with the content, and to pave the way for more in-class activities and skill practice. Secondly, the instructor aimed to examine students’ willingness to have the course contact hours remain the same with some online components to be done at home (flipped approach) or if students were open to turn the class into a blended format with two scenarios; either to have the current contact hours and apply the blended and in this case the face to face component will be less or keep the number of face to face classes the same and add more online structured classes as part of the course hours.

Keywords: blended learning, flipped classroom, graduate students, education

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17583 Investigation of Some Sperm Quality Parameters of Farmed and Wild-Caught Meagre (Argyrosomus regius Asso, 1801)

Authors: Şefik Surhan Tabakoğlu, Hipolito Fernández-Palacios, Dominique Schuchardt, Mahmut Ali Gökçe, Celal Erbaş, Oğuz Taşbozan

Abstract:

This study aimed to clarify some sperm quality parameters such as volumetric sperm quantity, motility, motility duration, sperm density, total number of spermatozoa and pH of meagre (Argyrosomus regius ASSO, 1801) individuals kept in farming conditions and caught from wild (las palmas, gran canary). The sperm was collected in glass tubes graded in millimetres and sperm volume registered immediately following collection by abdominal massage. The sperm quality parameters including motility, total number of spermatozoa and spermatozoa density were determined with computer assisted sperm analysis (CASA) program. The duration of spermatozoa movement was assessed using a sensitive chronometer (1/100s) that was started simultaneously with the addition of activation solution into the sample. Sperm pH was measured with standard pH electrodes within five minutes of sampling. At the end of the study, while amount of sperm (5.20±0.33 ml), duration of motility (7.23±0.7 m) and total number of spermatozoa (131.40±12.22 x10^9) were different statistically (p < 0,05), motility (% 81.03±6.59), pH (7.30±0.08), sperm density (25.27±9.42 x10^9/ml) and morphologic parameters were not significantly different between the two groups. According to our results, amount of sperm, duration of motility and total number of spermatozoa were better in farmed group than that of the other group.

Keywords: Seriola rivoliana, meagre, sperm quality, motility, motility duration

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17582 Anti-crisis Public Relations and Aspects of Effective Management in Georgian Companies

Authors: Marine Kobalava

Abstract:

Introduction. The paper substantiates the crucial role of anti-crisis PR in managing the image and reputation of companies. The critical situation caused by the Covid-19 virus in various countries of the world and the actions taken have had a significant negative impact on the image of companies and public groups. The mentioned circumstance has caused some problems for companies’ products in terms of customer demand. Accordingly, the main goal of PR has become to achieve the optimal relationship between companies and society with effective management. It should also be taken into account that the range of action of PR in crisis situations is much wider than that of advertising. In the paper, Public Relations is evaluated as a determining factor of the companies' prestige, its reliability, which has a decisive effect on the goodwill, trust, and general reputation of the public towards the company. The purpose of the study is to reveal the challenges of anti-crisis PR in Georgian companies and to develop recommendations on effective management mechanisms. Methodologies. Analysis, induction, synthesis, and other methods are used in the paper; Matrix and SWOT analysis are constructed. Ways of establishing and implementing an anti-crisis PR system in companies are proposed. The main aspects of anti-crisis management are identified by using the matrix of the choice of diversification strategy of the companies' activities, the possibilities of making adequate decisions using PR are studied according to the characteristics of the companies' activities and priority directions. Conclusion. The paper draws conclusions on modern problems of anti-crisis PR, offers recommendations on ways to solve it through PR strategies.

Keywords: anti-crisis PR, effective management, company, PR strategy

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17581 Using Multi-Arm Bandits to Optimize Game Play Metrics and Effective Game Design

Authors: Kenny Raharjo, Ramon Lawrence

Abstract:

Game designers have the challenging task of building games that engage players to spend their time and money on the game. There are an infinite number of game variations and design choices, and it is hard to systematically determine game design choices that will have positive experiences for players. In this work, we demonstrate how multi-arm bandits can be used to automatically explore game design variations to achieve improved player metrics. The advantage of multi-arm bandits is that they allow for continuous experimentation and variation, intrinsically converge to the best solution, and require no special infrastructure to use beyond allowing minor game variations to be deployed to users for evaluation. A user study confirms that applying multi-arm bandits was successful in determining the preferred game variation with highest play time metrics and can be a useful technique in a game designer's toolkit.

Keywords: game design, multi-arm bandit, design exploration and data mining, player metric optimization and analytics

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17580 Natural Convection in Wavy-Wall Cavities Filled with Power-Law Fluid

Authors: Cha’o-Kuang Chen, Ching-Chang Cho

Abstract:

This paper investigates the natural convection heat transfer performance in a complex-wavy-wall cavity filled with power-law fluid. In performing the simulations, the continuity, Cauchy momentum and energy equations are solved subject to the Boussinesq approximation using a finite volume method. The simulations focus specifically on the effects of the flow behavior index in the power-law model and the Rayleigh number on the flow streamlines, isothermal contours and mean Nusselt number within the cavity. The results show that pseudoplastic fluids have a better heat transfer performance than Newtonian or dilatant fluids. Moreover, it is shown that for Rayleigh numbers greater than Ra=103, the mean Nusselt number has a significantly increase as the flow behavior index is decreased.

Keywords: non-Newtonian fluid, power-law fluid, natural convection, heat transfer enhancement, cavity, wavy wall

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17579 Characteristics of the Wake behind a Heated Cylinder in Relatively High Reynolds Number

Authors: Morteza Khashehchi, Kamel Hooman

Abstract:

Thermal effects on the dynamics and stability of the flow past a circular cylinder operating in the mixed convection regime is studied experimentally for Reynolds number (ReD) between 1000 and 4000, and different cylinder wall temperatures (Tw) between 25 and 75°C by means of Particle Image Velocimetry (PIV). The experiments were conducted in a horizontal wind tunnel with the heated cylinder placed horizontally. With such assumptions, the direction of the thermally induced buoyancy force acting on the fluid surrounding the heated cylinder would be perpendicular to the flow direction. In each experiment, to acquire 3000 PIV image pairs, the temperature and Reynolds number of the approach flow were held constant. By adjusting different temperatures in different Reynolds numbers, the corresponding Richardson number (RiD = Gr/Re^2) was varied between 0:0 (unheated) and 10, resulting in a change in the heat transfer process from forced convection to mixed convection. With increasing temperature of the wall cylinder, significant modifications of the wake flow pattern and wake vortex shedding process were clearly revealed. For cylinder at low wall temperature, the size of the wake and the vortex shedding process are found to be quite similar to those of an unheated cylinder. With high wall temperature, however, the high temperature gradient in the wake shear layer creates a type of vorticity with opposite sign to that of the shear layer vorticity. This temperature gradient vorticity weakens the strength of the shear layer vorticity, causing delay in reaching the recreation point. In addition to the wake characteristics, the shedding frequency for the heated cylinder is determined for all aforementioned cases. It is found that, as the cylinder wall is heated, the organization of the vortex shedding is altered and the relative position of the first detached vortices with respect to the second one is changed. This movement of the first detached vortex toward the second one increases the frequency of the shedding process. It is also found that the wake closure length decreases with increasing the Richardson number.

Keywords: heated cylinder, PIV, wake, Reynolds number

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17578 Role of Alternative Dispute Resolution (ADR) in Advancing UN-SDG 16 and Pathways to Justice in Kenya: Opportunities and Challenges

Authors: Thomas Njuguna Kibutu

Abstract:

The ability to access justice is an important facet of securing peaceful, just, and inclusive societies, as recognized by Goal 16 of the 2030 Agenda for Sustainable Development. Goal 16 calls for peace, justice, and strong institutions to promote the rule of law and access to justice at a global level. More specifically, Target 16.3 of the Goal aims to promote the rule of law at the national and international levels and ensure equal access to justice for all. On the other hand, it is now widely recognized that Alternative Dispute Resolution (hereafter, ADR) represents an efficient mechanism for resolving disputes outside the adversarial conventional court system of litigation or prosecution. ADR processes include but are not limited to negotiation, reconciliation, mediation, arbitration, and traditional conflict resolution. ADR has a number of advantages, including being flexible, cost-efficient, time-effective, and confidential, and giving the parties more control over the process and the results, thus promoting restorative justice. The methodology of this paper is a desktop review of books, journal articles, reports and government documents., among others. The paper recognizes that ADR represents a cornerstone of Africa’s, and more specifically, Kenya’s, efforts to promote inclusive, accountable, and effective institutions and achieve the objectives of goal 16. In Kenya, and not unlike many African countries, there has been an outcry over the backlog of cases that are yet to be resolved in the courts and the statistics have shown that the numbers keep on rising. While ADR mechanisms have played a major role in reducing these numbers, access to justice in the country remains a big challenge, especially to the subaltern. There is, therefore, a need to analyze the opportunities and challenges facing the application of ADR mechanisms as tools for accessing justice in Kenya and further discuss various ways in which we can overcome these challenges to make ADR an effective alternative to dispute resolution. The paper argues that by embracing ADR across various sectors and addressing existing shortcomings, Kenya can, over time, realize its vision of a more just and equitable society. This paper discusses the opportunities and challenges of the application of ADR in Kenya with a view to sharing the lessons and challenges with the wider African continent. The paper concludes that ADR mechanisms can provide critical pathways to justice in Kenya and the African continent in general but come with distinct challenges. The paper thus calls for concerted efforts of respective stakeholders to overcome these challenges.

Keywords: mediation, arbitration, negotiation, reconsiliation, Traditional conflict resolution, sustainable development

Procedia PDF Downloads 26