Search results for: moving load and nonlinear behavior of poor soil
Commenced in January 2007
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Paper Count: 15290

Search results for: moving load and nonlinear behavior of poor soil

4520 An Attempt on Antimicrobial Studies of Lanthanide Schiff Base Complexes

Authors: Lekha Logu

Abstract:

The coordination behavior of the newly synthesized Schiff base ligands, 4-bromo-2-((p-tolyl imino) methyl) phenol obtained by condensing para-toluidine with 5-bromo salicylaldehyde and N-(3,4-dichloro benzylidene)-4-methylbenzenamine obtained by condensing Para-toluidine with 3,4-dichloro benzaldehyde in ethanolic medium has been explored in this current study. The synthesized Schiff’s base ligands were complexed with lanthanide nitrate salts yielding [LnL(NO3)2(H2O)2]NO3, (Ln=Pr, Sm). Elemental analysis, conductance measurement, and spectral techniques like Nuclear Magnetic Resonance (NMR), Ultraviolet-visible (UV-Vis) and Fourier Transform Infrared (FTIR) have been used to characterize Schiff’s base ligands and their lanthanide metal complexes. An attempt has been made on these complexes for their antimicrobial activity against the gram-positive and gram-negative bacterial species like Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Klebsiella pneumonia and fungal species like Canadida and Aspergillus.

Keywords: lanthanide complexes, Schiff's base, antimicrobial assay, synthesis, characterization

Procedia PDF Downloads 69
4519 A Reflection on the Professional Development Journey of Science Educators

Authors: M. Shaheed Hartley

Abstract:

Science and mathematics are regarded as gateway subjects in South Africa as they are the perceived route to careers in science, engineering, technology and mathematics (STEM). One of the biggest challenges that the country faces is the poor achievement of learners in these two learning areas in the external high school exit examination. To compound the problem many national and international benchmark tests paint a bleak picture of the state of science and mathematics in the country. In an attempt to address this challenge, the education department of the Eastern Cape Province invited the Science Learning Centre of the University of the Western Cape to provide training to their science teachers in the form of a structured course conducted on a part-time basis in 2010 and 2011. The course was directed at improving teachers’ content knowledge, pedagogical strategies and practical and experimental skills. A total of 41 of the original 50 science teachers completed the course and received their certificates in 2012. As part of their continuous professional development, 31 science teachers enrolled for BEd Hons in science education in 2013 and 28 of them completed the course in 2014. These students graduated in 2015. Of the 28 BEd Hons students who completed the course 23 registered in 2015 for Masters in Science Education and were joined by an additional 3 students. This paper provides a reflection by science educators on the training, supervision and mentorship provided to them as students of science education. The growth and development of students through their own reflection and understanding as well as through the eyes of the lecturers and supervisors that took part in the training provide the evaluation of the professional development process over the past few years. This study attempts to identify the merits, challenges and limitations of this project and the lessons to be learnt on such projects. It also documents some of the useful performance indicators with a view to developing a framework for good practice for such programmes.

Keywords: reflection, science education, professional development, rural schools

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4518 Effect of Different Diesel Fuels on Formation of the Cavitation Phenomena

Authors: Mohammadreza Nezamirad, Sepideh Amirahmadian, Nasim Sabetpour, Azadeh Yazdi, Amirmasoud Hamedi

Abstract:

Cavitation inside the diesel injector nozzle is investigated numerically in this study. Reynolds Stress Navier Stokes set of equations (RANS) are utilized to investigate flow behavior inside the nozzle numerically. Moreover, K-ε turbulent model is found to be a better approach comparing to K-ω turbulent model. Winklhofer rectangular shape nozzle is also simulated in order to verify the current numerical scheme, and with, mass flow rate approach, the current solution is verified. Afterward, a six-hole real-size nozzle was simulated, and it was found that among different fuels used in this study with the same condition, diesel fuel provides the largest length of cavitation. Also, it was found that at the same boundary condition, RME fuel leads to the highest value of discharge coefficient and mass flow rate.

Keywords: cavitation, diesel fuel, CFD, real size nozzle, discharge coefficient

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4517 Shear Strengthening of Reinforced Concrete Deep Beam Using Fiber Reinforced Polymer Strips

Authors: Ruqaya H. Aljabery

Abstract:

Reinforced Concrete (RC) deep beams are one of the main critical structural elements in terms of safety since significant loads are carried in a short span. The shear capacity of these sections cannot be predicted accurately by the current design codes like ACI and EC2; thus, they must be investigated. In this research, non-linear behavior of RC deep beams strengthened in shear with Fiber Reinforced Polymer (FRP) strips, and the efficiency of FRP in terms of enhancing the shear capacity in RC deep beams are examined using Finite Element Analysis (FEA), which is conducted using the software ABAQUS. The effect of several parameters on the shear capacity of the RC deep beam are studied in this paper as well including the effect of the cross-sectional area of the FRP strip and the shear reinforcement area to the spacing ratio (As/S), and it was found that FRP enhances the shear capacity significantly and can be a substitution of steel stirrups resulting in a more economical design.

Keywords: Abaqus, concrete, deep beam, finite element analysis, FRP, shear strengthening, strut-and-tie

Procedia PDF Downloads 150
4516 The Influence of Website Quality on Customer E-Satisfaction in Low Cost Airline

Authors: Zainab Khalifah, Wong Chiet Bing, Noor Hazarina Hashim

Abstract:

The evolution of customer behavior in purchasing products or services through the Internet leads to airline companies engaging in the e-ticketing process in order to maintain their business. A well-designed website is vitally significant for the airline companies to provide effective communication, support, and competitive advantage. This study was conducted to identify the dimensions of website quality for low cost airline and to investigate the relationship between the website quality and customer e-satisfaction at low cost airline. A total of 381 responses were conveniently collected among local passengers at Low Cost Carrier Terminal, Kuala Lumpur via questionnaire distribution. This study found that the five determinant factors of website quality for AirAsia were Information Content, Navigation, Responsiveness, Personalization, and Security and Privacy. The results of this study revealed that there is a positive relationship between the five dimensions of website quality and customer e-satisfaction, and also information content was the most significant contributor to customer e-satisfaction.

Keywords: website quality, customer e-satisfaction, low cost airline, e-ticketing

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4515 An Investigation on the Need to Provide Environmental Sanitation Facilities to Informal Settlement in Shagari Low-Cost Katsina State for Sustainable Built Environment

Authors: Abdullahi Mannir Rawayau

Abstract:

This paper identifies the problems that have aided the decoy to adequate basic infrastructural amenities, sub-standard housing, over-crowding, poor ventilation in homes and work places, sanitation, and non-compliance with building bye-laws and regulation. The paper also asserts the efficient disposal of solid and liquid waste is one of the challenges in the informal areas due to threats on the environment and public health. Sanitation services in the informal settlements have been found to be much lower compared to the average for unban. Bearing in mind a factor which prevents sustainable sanitation in informal areas which include low incomes, insecure tenure, low education levels, difficulty topography and transitory populations, and this study aim to identify effective strategies for achieving sustainable sanitation with specific reference to the informal settlement. Using the Shanghai Low-Cost as a case study. The primary data collected was through observation and interview method. Similarly, the secondary data used for the study was collected through literature reviews from extent studies with specific reference to informal settlement. A number of strategies towards achieving sustainable sanitation in the study were identified here in classified into three (3):- Advocacy and capacity building, infrastructural provision and institutionalization of systems and processes. The paper concludes with the premise on the need to build alliances between the government and stakeholders concerned with sanitation provision through the creation of sanitation and employ adaptable technology. Provision of sanitation facilities in public areas and to establish a statutory body for timely response to sanitation waste management in Katsina. It is imperative to check and prevent further decay for harmonious living and sustainable development.

Keywords: built environment, sanitation, facilities, settlement

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4514 Influence of Wind Induced Fatigue Damage in the Reliability of Wind Turbines

Authors: Emilio A. Berny-Brandt, Sonia E. Ruiz

Abstract:

Steel tubular towers serving as support structures for large wind turbines are subject to several hundred million stress cycles arising from the turbulent nature of the wind. This causes high-cycle fatigue which can govern tower design. The practice of maintaining the support structure after wind turbines reach its typical 20-year design life have become common, but without quantifying the changes in the reliability on the tower. There are several studies on this topic, but most of them are based on the S-N curve approach using the Miner’s rule damage summation method, the de-facto standard in the wind industry. However, the qualitative nature of Miner’s method makes desirable the use of fracture mechanics to measure the effects of fatigue in the capacity curve of the structure, which is important in order to evaluate the integrity and reliability of these towers. Temporal and spatially varying wind speed time histories are simulated based on power spectral density and coherence functions. Simulations are then applied to a SAP2000 finite element model and step-by-step analysis is used to obtain the stress time histories for a range of representative wind speeds expected during service conditions of the wind turbine. Rainflow method is then used to obtain cycle and stress range information of each of these time histories and a statistical analysis is performed to obtain the distribution parameters of each variable. Monte Carlo simulation is used here to evaluate crack growth over time in the tower base using the Paris-Erdogan equation. A nonlinear static pushover analysis to assess the capacity curve of the structure after a number of years is performed. The capacity curves are then used to evaluate the changes in reliability of a steel tower located in Oaxaca, Mexico, where wind energy facilities are expected to grow in the near future. Results show that fatigue on the tower base can have significant effects on the structural capacity of the wind turbine, especially after the 20-year design life when the crack growth curve starts behaving exponentially.

Keywords: crack growth, fatigue, Monte Carlo simulation, structural reliability, wind turbines

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4513 Mathematical Modeling of Avascular Tumor Growth and Invasion

Authors: Meitham Amereh, Mohsen Akbari, Ben Nadler

Abstract:

Cancer has been recognized as one of the most challenging problems in biology and medicine. Aggressive tumors are a lethal type of cancers characterized by high genomic instability, rapid progression, invasiveness, and therapeutic resistance. Their behavior involves complicated molecular biology and consequential dynamics. Although tremendous effort has been devoted to developing therapeutic approaches, there is still a huge need for new insights into the dark aspects of tumors. As one of the key requirements in better understanding the complex behavior of tumors, mathematical modeling and continuum physics, in particular, play a pivotal role. Mathematical modeling can provide a quantitative prediction on biological processes and help interpret complicated physiological interactions in tumors microenvironment. The pathophysiology of aggressive tumors is strongly affected by the extracellular cues such as stresses produced by mechanical forces between the tumor and the host tissue. During the tumor progression, the growing mass displaces the surrounding extracellular matrix (ECM), and due to the level of tissue stiffness, stress accumulates inside the tumor. The produced stress can influence the tumor by breaking adherent junctions. During this process, the tumor stops the rapid proliferation and begins to remodel its shape to preserve the homeostatic equilibrium state. To reach this, the tumor, in turn, upregulates epithelial to mesenchymal transit-inducing transcription factors (EMT-TFs). These EMT-TFs are involved in various signaling cascades, which are often associated with tumor invasiveness and malignancy. In this work, we modeled the tumor as a growing hyperplastic mass and investigated the effects of mechanical stress from surrounding ECM on tumor invasion. The invasion is modeled as volume-preserving inelastic evolution. In this framework, principal balance laws are considered for tumor mass, linear momentum, and diffusion of nutrients. Also, mechanical interactions between the tumor and ECM is modeled using Ciarlet constitutive strain energy function, and dissipation inequality is utilized to model the volumetric growth rate. System parameters, such as rate of nutrient uptake and cell proliferation, are obtained experimentally. To validate the model, human Glioblastoma multiforme (hGBM) tumor spheroids were incorporated inside Matrigel/Alginate composite hydrogel and was injected into a microfluidic chip to mimic the tumor’s natural microenvironment. The invasion structure was analyzed by imaging the spheroid over time. Also, the expression of transcriptional factors involved in invasion was measured by immune-staining the tumor. The volumetric growth, stress distribution, and inelastic evolution of tumors were predicted by the model. Results showed that the level of invasion is in direct correlation with the level of predicted stress within the tumor. Moreover, the invasion length measured by fluorescent imaging was shown to be related to the inelastic evolution of tumors obtained by the model.

Keywords: cancer, invasion, mathematical modeling, microfluidic chip, tumor spheroids

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4512 Efficacy of Phonological Awareness Intervention for People with Language Impairment

Authors: I. Wardana Ketut, I. Suparwa Nyoman

Abstract:

This study investigated the form and characteristic of speech sound produced by three Balinese subjects who have recovered from aphasia as well as intervened their language impairment on side of linguistic and neuronal aspects of views. The failure of judging the speech sound was caused by impairment of motor cortex that indicated there were lesions in left hemispheric language zone. Sound articulation phenomena were in the forms of phonemes deletion, replacement or assimilation in individual words and meaning building for anomic aphasia. Therefore, the Balinese sound patterns were stimulated by showing pictures to the subjects and recorded to recognize what individual consonants or vowels they unclearly produced and to find out how the sound disorder occurred. The physiology of sound production by subject’s speech organs could not only show the accuracy of articulation but also any level of severity the lesion they suffered from. The subjects’ speech sounds were investigated, classified and analyzed to know how poor the lingual units were and observed to clarify weaknesses of sound characters occurred either for place or manner of articulation. Many fricative and stopped consonants were replaced by glottal or palatal sounds because the cranial nerve, such as facial, trigeminal, and hypoglossal underwent impairment after the stroke. The phonological intervention was applied through a technique called phonemic articulation drill and the examination was conducted to know any change has been obtained. The finding informed that some weak articulation turned into clearer sound and simple meaning of language has been conveyed. The hierarchy of functional parts of brain played important role of language formulation and processing. From this finding, it can be clearly emphasized that this study supports the role of right hemisphere in recovery from aphasia is associated with functional brain reorganization.

Keywords: aphasia, intervention, phonology, stroke

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4511 On Four Models of a Three Server Queue with Optional Server Vacations

Authors: Kailash C. Madan

Abstract:

We study four models of a three server queueing system with Bernoulli schedule optional server vacations. Customers arriving at the system one by one in a Poisson process are provided identical exponential service by three parallel servers according to a first-come, first served queue discipline. In model A, all three servers may be allowed a vacation at one time, in Model B at the most two of the three servers may be allowed a vacation at one time, in model C at the most one server is allowed a vacation, and in model D no server is allowed a vacation. We study steady the state behavior of the four models and obtain steady state probability generating functions for the queue size at a random point of time for all states of the system. In model D, a known result for a three server queueing system without server vacations is derived.

Keywords: a three server queue, Bernoulli schedule server vacations, queue size distribution at a random epoch, steady state

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4510 Non-Destructive Static Damage Detection of Structures Using Genetic Algorithm

Authors: Amir Abbas Fatemi, Zahra Tabrizian, Kabir Sadeghi

Abstract:

To find the location and severity of damage that occurs in a structure, characteristics changes in dynamic and static can be used. The non-destructive techniques are more common, economic, and reliable to detect the global or local damages in structures. This paper presents a non-destructive method in structural damage detection and assessment using GA and static data. Thus, a set of static forces is applied to some of degrees of freedom and the static responses (displacements) are measured at another set of DOFs. An analytical model of the truss structure is developed based on the available specification and the properties derived from static data. The damages in structure produce changes to its stiffness so this method used to determine damage based on change in the structural stiffness parameter. Changes in the static response which structural damage caused choose to produce some simultaneous equations. Genetic Algorithms are powerful tools for solving large optimization problems. Optimization is considered to minimize objective function involve difference between the static load vector of damaged and healthy structure. Several scenarios defined for damage detection (single scenario and multiple scenarios). The static damage identification methods have many advantages, but some difficulties still exist. So it is important to achieve the best damage identification and if the best result is obtained it means that the method is Reliable. This strategy is applied to a plane truss. This method is used for a plane truss. Numerical results demonstrate the ability of this method in detecting damage in given structures. Also figures show damage detections in multiple damage scenarios have really efficient answer. Even existence of noise in the measurements doesn’t reduce the accuracy of damage detections method in these structures.

Keywords: damage detection, finite element method, static data, non-destructive, genetic algorithm

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4509 Use of Waste Tire Rubber Alkali-Activated-Based Mortars in Repair of Concrete Structures

Authors: Mohammad Ebrahim Kianifar, Ehsan Ahmadi

Abstract:

Reinforced concrete structures experience local defects such as cracks over their lifetime under various environmental loadings. Consequently, they are repaired by mortars to avoid detrimental effects such as corrosion of reinforcement, which in long-term may lead to strength loss of a member or collapse of structures. However, repaired structures may need multiple repairs due to changes in load distribution, and thus, lack of compatibility between mortar and substrate concrete. On the other hand, waste tire rubber alkali-activated (WTRAA)-based materials have very high potential to be used as repair mortars because of their ductility and flexibility, which may delay the failure of repair mortar and thus, provide sufficient compatibility. Hence, this work presents a pioneering study on suitability of WTRAA-based materials as mortars for the repair of concrete structures through an experimental program. To this end, WTRAA mortars with 15% aggregate replacement, alkali-activated (AA) mortars, and ordinary mortars are made to repair a number of concrete beams. The WTRAA mortars are composed of slag as base material, sodium hydroxide as an alkaline activator, and different gradations of waste tire rubber (fine and coarse gradations). Flexural tests are conducted on the concrete beams repaired by the ordinary, AA, and WTRAA mortars. It is found that, despite having lower compressive strength and modulus of elasticity, the WTRAA and AA mortars increase the flexural strength of the repaired beams, give compatible failures, and provide sufficient mortar-concrete interface bondings. The ordinary mortars, however, show incompatible failure modes. This study demonstrates the promising application of WTRAA mortars in the practical repairs of concrete structures.

Keywords: alkali-activated mortars, concrete repair, mortar compatibility, flexural strength, waste tire rubber

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4508 A Constitutive Model of Ligaments and Tendons Accounting for Fiber-Matrix Interaction

Authors: Ratchada Sopakayang, Gerhard A. Holzapfel

Abstract:

In this study, a new constitutive model is developed to describe the hyperelastic behavior of collagenous tissues with a parallel arrangement of collagen fibers such as ligaments and tendons. The model is formulated using a continuum approach incorporating the structural changes of the main tissue components: collagen fibers, proteoglycan-rich matrix and fiber-matrix interaction. The mechanical contribution of the interaction between the fibers and the matrix is simply expressed by a coupling term. The structural change of the collagen fibers is incorporated in the constitutive model to describe the activation of the fibers under tissue straining. Finally, the constitutive model can easily describe the stress-stretch nonlinearity which occurs when a ligament/tendon is axially stretched. This study shows that the interaction between the fibers and the matrix contributes to the mechanical tissue response. Therefore, the model may lead to a better understanding of the physiological mechanisms of ligaments and tendons under axial loading.

Keywords: constitutive model, fiber-matrix, hyperelasticity, interaction, ligament, tendon

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4507 Potential of Castor Bean (Ricinus Communis L.) for Phytoremediation of Soils Contaminated with Heavy Metals

Authors: Violina Angelova, Mariana Perifanova-Nemska, Krasimir Ivanov

Abstract:

The aim of this research was to investigate the potential for the use of Ricinus communis L. (castor oil plant) to remediate metal-polluted sites. This study was performed in industrially polluted soils containing high concentrations of Zn, Pb and Cd, situated at different distances (0.3, 2.0 and 15.0 km) from the source of pollution - the Non-Ferrous Metal Works near Plovdiv, Bulgaria. On reaching commercial ripeness, the castor oil plants were gathered and the contents of heavy metals in their different parts – roots, stems, leaves and seeds, were determined after dry ashing. Physico-chemical characterization, total, DTPA extractable and water-soluble metals in rhizospheric soil samples were carried. Translocation factors (TFs) were also determined. The quantitative measurements were carried out with ICP. A soxhlet extraction was used for the extraction of the oil, using hexane as solvent. The oil was recovered by simple distillation of the solvent. The residual oil obtained was investigated for physicochemical parameters and fatty acid composition. Bioaccumulation factor and translocation factor values (BAF and TF > 1) were greater than one suggesting efficient accumulation in the shoot. The castor oil plant may be preferred as a good candidate for phytoremediation (phytoextraction). These results indicate that R. communis has good potential for removing Pb from contaminated soils attributed to its fast growth, high biomass, strong absorption and accumulation for Pb. The concentrations of heavy metals in the oil were low as seed coats accumulated the highest concentrations of Cd and Pb. In addition, the result of the fatty acid composition analysis confirms the oil to be of good quality and can be used for industrial purposes such as cosmetics, soaps and paint.

Keywords: castor bean, heavy metals, phytoremediation, polluted soils

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4506 Tribological Properties of Non-Stick Coatings Used in Bread Baking Process

Authors: Maurice Brogly, Edwige Privas, Rajesh K. Gajendran, Sophie Bistac

Abstract:

Anti-sticky coatings based on perfluoroalkoxy (PFA) coatings are widely used in food processing industry especially for bread making. Their tribological performance, such as low friction coefficient, low surface energy and high heat resistance, make them an appropriate choice for anti-sticky coating application in moulds for food processing industry. This study is dedicated to evidence the transfer of contaminants from the coating due to wear and thermal ageing of the mould. The risk of contamination is induced by the damage of the coating by bread crust during the demoulding stage. The study focuses on the wear resistance and potential transfer of perfluorinated polymer from the anti-sticky coating. Friction between perfluorinated coating and bread crust is modeled by a tribological pin-on-disc test. The cellular nature of the bread crust is modeled by a polymer foam. FTIR analysis of the polymer foam after friction allow the evaluation of the transfer from the perfluorinated coating to polymer foam. Influence of thermal ageing on the physical, chemical and wear properties of the coating are also investigated. FTIR spectroscopic results show that the increase of PFA transfer onto the foam counterface is associated to the decrease of the friction coefficient. Increasing lubrication by film transfer results in the decrease of the friction coefficient. Moreover increasing the friction test parameters conditions (load, speed and sliding distance) also increase the film transfer onto the counterface. Thermal ageing increases the hydrophobic character of the PFA coating and thus also decreases the friction coefficient.

Keywords: fluorobased polymer coatings, FTIR spectroscopy, non-stick food moulds, wear and friction

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4505 The Key Role of Yttrium Oxide on Devitrification Resilience of Barium Gallo-germanate Glasses: Physicochemical Properties and Crystallization Study

Authors: Samar Aoujia, Théo Guérineaub, Rayan Zaitera, Evelyne Fargina, Younès Messaddeqb, Thierry Cardinala

Abstract:

Two barium gallo-germanate glass series were elaborated to investigate the effect of the yttrium introduction on the glass physicochemical properties and crystallization behavior. One to twenty mol% of YO3/2 were either added into the glass matrix or substituted for gallium oxide. The glass structure was studied by Raman spectroscopy, and the thermal, optical, thermo-mechanical and physical properties are examined. The introduction of yttrium ions in both glass series increases the glass transition temperature, crystallization temperature, softening temperature, coefficient of linear thermal expansion and density. Through differential scanning calorimetry and X-ray diffraction analyses, it was found that competition occurs between the gallo-germanate zeolite-type phase and the yttrium-containing phase. From 13 mol% of YO3/2, the yttrium introduction impedes the formation of surface crystallization in these glasses.

Keywords: photonic, heavy-metal oxide, glass, crystallization

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4504 ACO-TS: an ACO-based Algorithm for Optimizing Cloud Task Scheduling

Authors: Fahad Y. Al-dawish

Abstract:

The current trend by a large number of organizations and individuals to use cloud computing. Many consider it a significant shift in the field of computing. Cloud computing are distributed and parallel systems consisting of a collection of interconnected physical and virtual machines. With increasing request and profit of cloud computing infrastructure, diverse computing processes can be executed on cloud environment. Many organizations and individuals around the world depend on the cloud computing environments infrastructure to carry their applications, platform, and infrastructure. One of the major and essential issues in this environment related to allocating incoming tasks to suitable virtual machine (cloud task scheduling). Cloud task scheduling is classified as optimization problem, and there are several meta-heuristic algorithms have been anticipated to solve and optimize this problem. Good task scheduler should execute its scheduling technique on altering environment and the types of incoming task set. In this research project a cloud task scheduling methodology based on ant colony optimization ACO algorithm, we call it ACO-TS Ant Colony Optimization for Task Scheduling has been proposed and compared with different scheduling algorithms (Random, First Come First Serve FCFS, and Fastest Processor to the Largest Task First FPLTF). Ant Colony Optimization (ACO) is random optimization search method that will be used for assigning incoming tasks to available virtual machines VMs. The main role of proposed algorithm is to minimizing the makespan of certain tasks set and maximizing resource utilization by balance the load among virtual machines. The proposed scheduling algorithm was evaluated by using Cloudsim toolkit framework. Finally after analyzing and evaluating the performance of experimental results we find that the proposed algorithm ACO-TS perform better than Random, FCFS, and FPLTF algorithms in each of the makespaan and resource utilization.

Keywords: cloud Task scheduling, ant colony optimization (ACO), cloudsim, cloud computing

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4503 A Case Study of Response to Dual Genotype Chronic Hepatitis C/HIV Co-Infection to Fixed Dose Sofosbuvir/Ledipasvir

Authors: Tabassum Yasmin, Hamid Pahlevan

Abstract:

HIV/Hepatitis C co-infection treatments have evolved substantially and they have similar sustained virologic response rates as those of Hepatitis C monoinfected population. There are a few studies on therapy of patients with dual genotypes, especially in HIV/Hepatic C coinfected group. Most studies portrayed case reports of dual genotype chronic Hepatitis C coinfection treatment with Sofosbuvir/Ledipasvir and Ribavirin. A 79-year-old male with a history of HIV on Truvada and Isentress had chronic Hepatitis C with 1a and 2 genotypes. The patient has a history of alcohol intake for 40 years but recently stopped drinking alcohol. He has a history of intravenous drug use in the past and currently is not using any recreational drugs. Patient has Fibro score of 0.7 with Metavir score F2 to F4. AFP is 3.2. The HCV RNA is 493,034 IU/ML. The HBV viral DNA is < 1.30 (not detected). The CD4 is 687CU/MM. The FIB 4 is 3.34 with APRI index 0.717. The HIV viral load is 101 copies/ML. MRI abdomen did not show any liver abnormality. Fixed dose Sofosbuvir/Ledipasvir was used for therapy without Ribavirin. He tolerated medication except for some minor gastrointestinal side effects like abdominal bloating. He demonstrated 100% adherence rate. Patient completed 12 weeks of therapy. HCV RNA was undetectable at 4 and 12 weeks. He achieved SVR at week 12 and subsequently had undetectable RNA for 2 years. Dual genotype prevalence in chronic hepatitis C population is rare, especially in HIV/hepatic coinfection. Our case demonstrates that dual genotypic cases can still be successfully treated with Direct Acting Antiviral agents. The newer agents for therapy for pan genotypes were not available at the time the patient was being treated. We demonstrated that dual agent therapy was still able to maintain SVR in our patient.

Keywords: HIV/Hepatitis C, SVR (sustained virologic response), DAA (direct active antiviral agents, dual genotype

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4502 The Effectiveness of Gamified Learning on Student Learning in Computer Science Education: A Systematic Review (2010-2018)

Authors: Shurui Bai, Biyun Huang, Khe Foon Hew

Abstract:

Gamification is defined as the use of game design elements in non-game contexts. The primary purpose of using gamification in an educational context is to engage students in school activities such that their likelihood of completion is increased. But how actually effective is gamification in improving student learning? In order to answer this question, this paper provides a systematic review of prior research studies on gamification in K-12 and university contexts limited to computer science discipline. Unlike other published gamification review works, we specifically analyzed comparison-based studies in quasi-experiment, historical control, and randomization rather than studies with mere anecdotal or phenomenological results. The main purpose for this is to discuss possible causal effects of gamified practices on student performance, behavior change, and perceptual skills following an integrative model. Implications for practice are discussed, along with several suggestions for future research studies.

Keywords: computer science, gamification, learning performance, systematic review

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4501 Effect of Concrete Strength on the Bond Between Carbon Fiber Reinforced Polymer and Concrete in Hot Weather

Authors: Usama Mohamed Ahamed

Abstract:

This research deals with the bond behavior of carbon FRP composite wraps adhered/bonded to the surface of the concrete. Four concrete mixes were designed to achieve a concrete compressive strength of 18, 22.5,25 and 30 MP after 28 days of curing. The focus of the study is on bond degradation when the hybrid structure is exposed to hot weather conditions. Specimens were exposed to 50 0C temperature duration 6 months and other specimens were sustained in laboratory temperature ( 20-24) 0C. Upon removing the specimens from their conditioning environment, tension tests were performed in the machine using a specially manufactured concrete cube holder. A lightweight mortar layer is used to protect the bonded carbon FRP layer on the concrete surface. The results show that the higher the concrete's compressive, the higher the bond strength. The high temperature decreases the bond strength between concrete and carbon fiber-reinforced polymer. The use of a protection layer is essential for concrete exposed to hot weather.

Keywords: concrete, bond, hot weather and carbon fiber, carbon fiber reinforced polymers

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4500 Word of Mouth and Its Impact on Marketing

Authors: Fatima Naz, Ayesha Tariq

Abstract:

In view of growing of the internet users for e-commerce and taking into account, the emergent impact of word of mouth phenomenon this research has different aims. The aims of this study were built following dissimilar discussion with teachers and colleagues enlightening that word of mouth information for online purchasing do not have the same effect for everybody. Then they were born following dissimilar researchers together with what was already done in previous researches and what was completed. As a result different aims were drawn; the initial aim of this research is to study the attention of the customers in the word of mouth to power their online purchasing activities. The next aim is to analyze the people influenced by the interest of word of mouth. The following aim is to examine the marketing behavior bearing in mind the internet progress and word of mouth, their consideration for word of mouth marketing. In the form of research questions the aims of the study are: 1) How community utilizes and multiplies word of mouth information about online purchasing experience? 2) How communities perceive the word of mouth marketing? 3) How marketers take the word of mouth phenomenon and how they handle it?

Keywords: belief, power, inspiration, self-expression, positive attitude to online marketing, forwarding of contents, purchasing decision, standard marketing

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4499 Forecasting of Scaffolding Work Comfort Parameters Based on Data from Meteorological Stations

Authors: I. Szer, J. Szer, M. Pieńko, A. Robak, P. Jamińska-Gadomska

Abstract:

Work at height, such as construction works on scaffoldings, is associated with a considerable risk. Scaffolding workers are usually exposed to changing weather conditions what can additionally increase the risk of dangerous situations. Therefore, it is very important to foresee the risk of adverse conditions to which the worker may be exposed. The data from meteorological stations may be used to asses this risk. However, the dependency between weather conditions on a scaffolding and in the vicinity of meteorological station, should be determined. The paper presents an analysis of two selected environmental parameters which have influence on the behavior of workers – air temperature and wind speed. Measurements of these parameters were made between April and November of 2016 on ten scaffoldings located in different parts of Poland. They were compared with the results taken from the meteorological stations located closest to the studied scaffolding. The results gathered from the construction sites and meteorological stations were not the same, but statistical analyses have shown that they were correlated.

Keywords: scaffolding, health and safety at work, temperature, wind velocity

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4498 Bioefficacy of Diclosulam for Controlling Weeds in Soybean [Glycine Max (L.) Merrill] and Its Carry Over Effect on Succeeding Wheat (Triticum Aestivum) Crop

Authors: Pratap Sing, Chaman. K. Jadon, H. P. Meena, D. L.yadav, S. L. Yadav, Uditi Dhakad

Abstract:

The experiment was conducted at Agricultural Research Station, Agriculture University, Kota, Rajasthan, India during kharif and rabi 2020-21 and 2021-22 to study the biofficacy of diclosulam and its residual effect on succeeding wheat crop. The treatments comprised of Diclosulam 84 % WDG viz. 6.25, 12.50, 25.00 and 37.50 g/ha as pre emergence (PE), Pendimethalin 30% EC 3.33 l/ha, Sulfentrazon 48% SC 750 g/ha, hand weeding at 30 and 45 DAS and weedy check, were evaluated in randomized block design in three replications. The experimental soil was clay in texture and non-calcareous. Experimental field was mainly dominated by grasses-Echinochloa colonum, E.crusgalli,Cynodon dactylon, Sedges-Cyperus rotundus and broad leaved weeds Celosia argentea and Digera arvensis.The result revealed that application of Diclosulam 84 % WDG 25 g/ha PE was found effective in controlling mostly weed species and registered higher weed control efficiency 81.2, 74.3, 69.6 per cent at 30, 45 days after sowing and at harvest. Diclosulam 84 % WDG (6.25-25.0 g/ha) was found selective to the soybean crop as no any phytotoxicity symptoms were observed. Among the herbicidal treatments, Diclosulam 84 % WDG 25 g/ha registered maximum and significantly higher soybean seed yield (1889 and 1431 kg/ha during kharif 2020 and 2021, respectively and was at par with Sulfentrazone 48% SC 750 g/ha and over weedy check( 1027 and 667 kg/ha).The wheat crop growth, yield attributes and seed yield were not influenced due to carry over effect of the Diclosulam 84 % WDG( 6.25-25.0 g/ha) and no any phytotoxicity symptoms were observed. Henceforth, the Diclosulam 84 % WDG 25.0 g/ha as pre emergence may be used in the soybean for effective weed control without carry over effect on succeeding wheat crop.

Keywords: Diclosulam, soybean, carry over effect, succeeding wheat

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4497 Reburning Characteristics of Biomass Syngas in a Pilot Scale Heavy Oil Furnace

Authors: Sang Heon Han, Daejun Chang, Won Yang

Abstract:

NOx reduction characteristics of syngas fuel were numerically investigated for the 2MW pilot scale heavy oil furnace of KITECH (Korea Institute of Industrial Technology). The secondary fuel and syngas was fed into the furnace with two purposes- partial replacement of main fuel and reburning of NOx. Some portion of syngas was fed into the flame zone to partially replace the heavy oil, while the other portion was fed into the furnace downstream to reduce NOx generation. The numerical prediction was verified by comparing it with the experimental results. Syngas of KITECH’s experiment, assumed to be produced from biomass, had very low calorific value and contained 3% hydrocarbon. This study investigated the precise behavior of NOx generation and NOx reduction as well as thermo-fluidic characteristics inside the furnace, which was unavailable with experiment. In addition to 3% hydrocarbon syngas, 5%, and 7% hydrocarbon syngas were numerically tested as reburning fuels to analyze the effect of hydrocarbon proportion to NOx reduction. The prediction showed that the 3% hydrocarbon syngas is as much effective as 7% hydrocarbon syngas in reducing NOx.

Keywords: syngas, reburning, heavy oil, furnace

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4496 Evidence-Based Policy Making to Improve Human Security in Pakistan

Authors: Ayesha Akbar

Abstract:

Pakistan is moving from a security state to a welfare state despite several security challenges both internal and external. Human security signifies a varied approach in different regions depending upon the leadership and policy priorities. The link between human development and economic growth is not automatic. It has to be created consciously by forward-looking policies and strategies by national governments. There are seven components or categories of human security these include: Economic Security, Personal Security, Health Security, Environmental Security, Food Security, Community Security and Political Security. The increasing interest of the international community to clearly understand the dimensions of human security provided the grounds to Pakistani scholars as well to ponder on the issue and delineate lines of human security. A great deal of work has been either done or in process to evaluate human security indicators in Pakistan. Notwithstanding, after having been done a great deal of work the human security in Pakistan is not satisfactory. A range of deteriorating indicators of human development that lies under the domain of human security leaves certain inquiries to be answered. What are the dimensions of human security in Pakistan? And how are they being dealt from the perspective of policy and institution in terms of its operationalization in Pakistan? Is the human security discourse reflects evidence-based policy changes. The methodology is broadly based on qualitative methods that include interviews, content analysis of policy documents. Pakistan is among the most populous countries in the world and faces high vulnerability to climate change. Literacy rate has gone down with the surge of youth bulge to accommodate in the job market. Increasing population is creating food problems as the resources have not been able to compete with the raising demands of food and other social amenities of life. Majority of the people are facing acute poverty. Health outcomes are also not satisfactory with the high infant and maternal mortality rate. Pakistan is on the verge of facing water crisis as the water resources are depleting so fast with the high demand in agriculture and energy sector. Pakistan is striving hard to deal with the declining state of human security but the dilemma is lack of resources that hinders in meeting up with the emerging demands. The government requires to bring about more change with scaling-up economic growth avenues with enhancing the capacity of human resources. A modern performance drive culture with the integration of technology is required to deliver efficient and effective service delivery. On an already fast track process of reforms; e-governance and evidence based policy mechanism is being instilled in the government process for better governance and evidence based decisions.

Keywords: governance, human development index, human security, Pakistan, policy

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4495 Family Firm Internationalization: Identification of Alternative Success Pathways

Authors: Sascha Kraus, Wolfgang Hora, Philipp Stieg, Thomas Niemand, Ferdinand Thies, Matthias Filser

Abstract:

In most countries, small and medium-sized enterprises (SME) are the backbone of the economy due to their impact on job creation, innovation and wealth creation. Moreover, the ongoing globalization makes it inevitable – even for SME that traditionally focused on their domestic markets – to internationalize their business activities to realize further growth and survive in international markets. Thus, internationalization has become one of the most common growth strategies for SME and has received increasing scholarly attention over the last two decades. One the downside internationalization can be also regarded as the most complex strategy that a firm can undertake. Particularly for family firms, that are often characterized by limited financial capital, a risk-averse nature and limited growth aspirations, it could be argued that family firms are more likely to face greater challenges when taking the pathway to internationalization. Especially the triangulation of family, ownership, and management (so-called ‘familiness’) manifests in a unique behavior and decision-making process which is often characterized by the importance given to noneconomic goals and distinguishes a family firm from other businesses. Taking this into account, the concept of socio-emotional wealth (SEW) has been evolved to describe the behavior of family firms. In order to investigate how different internal and external firm characteristics shape internationalization success of family firms, we drew on a sample consisting of 297 small and medium-sized family firms from Germany, Austria, Switzerland, and Liechtenstein. Thus, we include SEW as essential family firm characteristic and added the two major intra-organizational characteristics, entrepreneurial orientation (EO), absorptive capacity (AC) as well as collaboration intensity (CI) and relational knowledge (RK) as two major external network characteristics. Based on previous research we assume that these characteristics are important to explain internationalization success of family firm SME. Regarding the data analysis, we applied a Fuzzy Set Qualitative Comparative Analysis (fsQCA), an approach that allows identifying configurations of firm characteristics, specifically used to study complex causal relationships where traditional regression techniques reach their limits. Results indicate that several combinations of these family firm characteristics can lead to international success, with no permanently required key characteristic. Instead, there are many roads to walk down for family firms to achieve internationalization success. Consequently, our data states that family owned SME are heterogeneous and internationalization is a complex and dynamic process. Results further show that network related characteristics occur in all sets, thus represent an essential element in the internationalization process of family owned SME. The contribution of our study is twofold, as we investigate different forms of international expansion for family firms and how to improve them. First, we are able to broaden the understanding of the intersection between family firm and SME internationalization with respect to major intra-organizational and network-related variables. Second, from a practical perspective, we offer family firm owners a basis for setting up internal capabilities to achieve international success.

Keywords: entrepreneurial orientation, family firm, fsQCA, internationalization, socio-emotional wealth

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4494 Determining Sources of Sediments at Nkula Dam in the Middle Shire River, Malawi, Using Mineral Magnetic Approach

Authors: M. K. Mzuza, W. Zhang, L. S. Chapola, M. Tembo

Abstract:

Shire River is the largest and longest river in Malawi emptying its water into the Zambezi River in Mozambique. Siltation is now a major problem in the Shire River due to catchment degradation. This study analysed soil samples from tributaries of the Shire River to determine sources of sediments that cause siltation using the mineral magnetic approach. Bulk sediments and separated particle size fractions of representative samples were collected from tributaries on the western and eastern sides of the Shire River, and Nkula Dam. Eastern tributaries showed relatively higher ferrimagnetic mineral contents and ferrimagnetic to anti ferromagnetic ratios than western tributaries. Sediments from both sides of the Shire River were distinguished by χARM, SIRM versus χlf and S-100 versus SIRM. Findings in this study showed that most of the sediments originated from the western part of the Shire River. Tributaries on the eastern side of the Shire River had higher values for concentration related parameters (χlf, χfd, χARM, SIRM, HIRM, S-100, and χARM/SIRM) than tributaries on the western side. Bulky and detailed magnetic measurements carried out on particle size fractions provided additional confirmation of magnetic contrasts between the two sides of the river suggesting differences in lithology, topography, climate and weather regimes in the catchments. This study demonstrated that the magnetic approach can provide a reliable means of understanding major sediment sources of Nkula Dam and similar situations. It can also help to assess future variations in sediment composition resulting from catchment changes

Keywords: ferrimagnetic minerals, Shire River, tributaries rivers, particle size , topography

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4493 Isolation and Identification of Microorganisms from Marine-Associated Samples under Laboratory Conditions

Authors: Sameen Tariq, Saira Bano, Sayyada Ghufrana Nadeem

Abstract:

The Ocean, which covers over 70% of the world's surface, is wealthy in biodiversity as well as a rich wellspring of microorganisms with huge potential. The oceanic climate is home to an expansive scope of plants, creatures, and microorganisms. Marine microbial networks, which incorporate microscopic organisms, infections, and different microorganisms, enjoy different benefits in biotechnological processes. Samples were collected from marine environments, including soil and water samples, to cultivate the uncultured marine organisms by using Zobell’s medium, Sabouraud’s dextrose agar, and casein media for this purpose. Following isolation, we conduct microscopy and biochemical tests, including gelatin, starch, glucose, casein, catalase, and carbohydrate hydrolysis for further identification. The results show that more gram-positive and gram-negative bacteria. The isolation process of marine organisms is essential for understanding their ecological roles, unraveling their biological secrets, and harnessing their potential for various applications. Marine organisms exhibit remarkable adaptations to thrive in the diverse and challenging marine environment, offering vast potential for scientific, medical, and industrial applications. The isolation process plays a crucial role in unlocking the secrets of marine organisms, understanding their biological functions, and harnessing their valuable properties. They offer a rich source of bioactive compounds with pharmaceutical potential, including antibiotics, anticancer agents, and novel therapeutics. This study is an attempt to explore the diversity and dynamics related to marine microflora and their role in biofilm formation.

Keywords: marine microorganisms, ecosystem, fungi, biofilm, gram-positive, gram-negative

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4492 50+ Customers' Behavior in the Financial Market of the Czech Republic

Authors: K. Matušínská, H. Starzyczná, M. Stoklasa

Abstract:

The paper deals with behaviour of the segment 50+ in the financial market in the Czech Republic. This segment could be said as the strong market power and it can be a crucial business potential for financial business units. The main defined objective of this paper is analysis of the customers´ behaviour of the segment 50-60 years in the financial market in the Czech Republic and proposal making of the suitable marketing approach to satisfy their demands in the area of product, price, distribution and marketing communication policy. This paper is based on data from one part of primary marketing research. Paper determinates the basic problem areas as well as definition of financial services marketing, defining the primary research problem, hypothesis and primary research methodology. Finally suitable marketing approach to selected sub-segment at age of 50-60 years is proposed according to marketing research findings.

Keywords: population aging in the Czech Republic, segment 50-60 years, financial services marketing, marketing research, marketing approach

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4491 Experiment and Analytical Study on Fire Resistance Performance of Slot Type Concrete-Filled Tube

Authors: Bum Yean Cho, Heung-Youl Kim, Ki-Seok Kwon, Kang-Su Kim

Abstract:

In this study, a full-scale test and analysis (numerical analysis) of fire resistance performance of bare CFT column on which slot was used instead of existing welding method to connect the steel pipe on the concrete-filled tube were conducted. Welded CFT column is known to be vulnerable to high or low temperature because of low brittleness of welding part. As a result of a fire resistance performance test of slot CFT column after removing the welding part and fixing it by a slot which was folded into the tube, slot type CFT column indicated the improved fire resistance performance than welded CFT column by 28% or more. And as a result of conducting finite element analysis of slot type column using ABAQUS, analysis result proved the reliability of the test result in predicting the fire behavior and fire resistance hour.

Keywords: CFT (concrete-filled tube) column, fire resistance performance, slot, weld

Procedia PDF Downloads 184