Search results for: fixed effect model

Authors: M. Alam, P. Seshaiyer

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The rupture predictability of intracranial aneurysm is one of the most important parameters for physicians in surgical treatment. As most of the intracranial aneurysms are asymptomatic, still the rupture potential of both symptomatic and asymptomatic lesions is relatively unknown. Moreover, an intracranial aneurysm constrained by a nerve tissue might be a common scenario for a physician to deal with during the treatment process. Here, we perform a computational modeling of nerve tissue constrained intracranial saccular aneurysm to show a protective role of constrained tissue on the aneurysm. A comparative parametric study of the model also performs taking long constraint, medium constraint, short constraint, point contact, narrow neck aneurysm, wide neck aneurysm as parameters for the analysis. Results show that contact constraint aneurysm generates less stress near the fundus compared to no constraint aneurysm, hence works as a protective wall for the aneurysm not to be ruptured.

Keywords: rupture potential, intracranial saccular aneurysm, anisotropic hyper-elastic material, finite element analysis

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Authors: Amelia J. McFarland, Andrew K. Davey, Shailendra Anoopkumar-Dukie

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Microglia are the resident macrophage population of the central nervous system (CNS), contributing to both innate and adaptive immune response, and brain homeostasis. Activation of microglia occurs in response to a multitude of pathogenic stimuli in their microenvironment; this induces morphological and functional changes, resulting in a state of acute neuroinflammation which facilitates injury resolution. Adequate microglial function is essential for the health of the neuroparenchyma, with microglial dysfunction implicated in numerous CNS pathologies. Given the critical role that these macrophage-derived cells play in CNS homeostasis, there is a high demand for microglial models suitable for use in neuroscience research. The isolation of primary human microglia, however, is both difficult and costly, with microglial activation an unwanted but inevitable result of the extraction process. Consequently, there is a need for the development of alternative experimental models which exhibit morphological, biochemical and functional characteristics of human microglia without the difficulties associated with primary cell lines. In this study, our aim was to evaluate whether THP-1 human peripheral blood monocytes would display microglial-like qualities following an induced differentiation, and, therefore, be suitable for use as surrogate microglia. To achieve this aim, THP-1 human peripheral blood monocytes from acute monocytic leukaemia were differentiated with a range of phorbol 12-myristate 13-acetate (PMA) concentrations (50-200 nM) using two different protocols: a 5-day continuous PMA exposure or a 3-day continuous PMA exposure followed by a 5-day rest in normal media. In each protocol and at each PMA concentration, microglial-like cell morphology was assessed through crystal violet staining and the presence of CD-14 microglial / macrophage cell surface marker. Lipopolysaccharide (LPS) from Escherichia coli (055: B5) was then added at a range of concentrations from 0-10 mcg/mL to activate the PMA-differentiated THP-1 cells. Functional microglial-like behavior was evaluated by quantifying the release of prostaglandin (PG)-E2 and pro-inflammatory cytokines interleukin (IL)-1β and tumour necrosis factor (TNF)-α using mediator-specific ELISAs. Furthermore, production of global reactive oxygen species (ROS) and nitric oxide (NO) were determined fluorometrically using dichlorodihydrofluorescein diacetate (DCFH-DA) and diaminofluorescein diacetate (DAF-2-DA) respectively. Following PMA-treatment, it was observed both differentiation protocols resulted in cells displaying distinct microglial morphology from 10 nM PMA. Activation of differentiated cells using LPS significantly augmented IL-1β, TNF-α and PGE2 release at all LPS concentrations under both differentiation protocols. Similarly, a significant increase in DCFH-DA and DAF-2-DA fluorescence was observed, indicative of increases in ROS and NO production. For all endpoints, the 5-day continuous PMA treatment protocol yielded significantly higher mediator levels than the 3-day treatment and 5-day rest protocol. Our data, therefore, suggests that the differentiation of THP-1 human monocyte cells with PMA yields a homogenous microglial-like population which, following stimulation with LPS, undergo activation to release a range of pro-inflammatory mediators associated with microglial activation. Thus, the use of PMA-differentiated THP-1 cells represents a suitable microglial model for in vitro research.

Keywords: differentiation, lipopolysaccharide, microglia, monocyte, neuroscience, THP-1

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Authors: Amit Sharma, J. N. Sharma

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This paper deals with the study of reflection and transmission characteristics of acoustic waves at the interface of a semiconductor halfspace and elastic solid. The amplitude ratios (reflection and transmission coefficients) of reflected and transmitted waves to that of incident wave varying with the incident angles have been examined for the case of quasi-longitudinal wave. The special cases of normal and grazing incidence have also been derived with the help of Gauss elimination method. The mathematical model consisting of governing partial differential equations of motion and charge carriers diffusion of n-type semiconductors and elastic solid has been solved both analytically and numerically in the study. The numerical computations of reflection and transmission coefficients has been carried out by using MATLAB programming software for silicon (Si) semiconductor and copper elastic solid. The computer simulated results have been plotted graphically for Si semiconductors. The study may be useful in semiconductors, geology, and seismology in addition to surface acoustic wave (SAW) devices.

Keywords: quasilongitudinal, reflection and transmission, semiconductors, acoustics

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Authors: Jay J. Vora, Vishvesh J. Badheka

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This work attempts to investigate the effect of oxide fluxes on 6mm thick Reduced Activation ferritic/martensitic steels (RAFM) during Activated TIG (A-TIG) welding. Six different fluxes Al₂O₃, Co₃O₄, CuO, HgO, MoO₃, and NiO were mixed with methanol for conversion into paste and bead-on-plate experiments were then carried out. This study, systematically investigates the influence of oxide-based flux powder and carrier solvent composition on the weld bead shape, geometric shape of weld bead and dominant depth enhancing mechanism in tungsten inert gas (TIG) welding of reduced activation ferritic/martensitic (RAFM) steel. It was inferred from the study that flux Co₃O₄ and MoO₃ imparted full and secure (more than 6mm) penetration with methanol owing to dual mechanism of reversed Marangoni and arc construction. The use of methanol imparted good spreadabilty and coverability and ultimately higher peak temperatures were observed with its use owing to stronger depth enhancing mechanisms than use of acetone with same oxide fluxes and welding conditions.

Keywords: A-TIG, flux, oxides, penetration, RAFM, temperature, welding

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Authors: Amao Funmilayo Lanrewaju, T. Ogunlade

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The paper examines the causes and characteristics of informal settlements and outdoor advertisement in the evaluation of quality of environment. The paper identifies the problems that have aided informal settlements to: Urbanization, poverty, growth of informal sector, non-affordability of land and housing shortage. The paper asserts that the informal settlements have serious adverse effects on the people’s health, their built environment and quality of life. The secondary data was obtained from books, journals and seminar papers. The paper argues that, although the urban upgrading possesses great potential for improving quality of built environment in informal settlements, there is a need to repackage the upgrading exercise so that majority can benefit from it. It is necessary to incorporate community participation into the urban upgrading in order to assist the very poor that cannot take care of their housing consumption needs. Therefore, government is encouraged to see informal settlements as a solution to new city planning rather than problem to the urban areas. This paper suggests the implementation of policies and planning, physical infrastructural development, social economic improvement, environment and health improvement. Government, private and communities interventions on informal settlements are required in order to prevent further decay for sustainable development.

Keywords: quality of environment, informal settlements, urban upgrading, outdoor advertisement

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Authors: Yi-De Liu

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For many European cities, a key motivation in developing event strategies is to use event as a catalyst for urban regeneration. One type of event that is particularly used as a means of urban development is the European Capital of Culture (ECOC) initiative. Based on a case study of the 2008 ECOC Liverpool, this paper aims at conceptualising the significance of major event for a city’s economic, cultural and social regenerations. In terms of economic regeneration, the role of the ECOC is central in creating Liverpool’s visitor economy and reshaping city image. Liverpool planned different themes for eight consecutive years as a way to ensure economic sustainability. As far as cultural regeneration is concerned, the ECOC contributed to the cultural regeneration of Liverpool by stimulating cultural participation and interest from the demand side, as well as improving cultural provision and collaboration within the cultural sector from the supply side. So as to social regeneration, Liverpool treated access development as a policy guideline and considered the ECOC as an opportunity to enhance the sense of place. The most significant lesson learned from Liverpool is its long-term planning and efforts made to integrate the ECOC into the overall urban development strategy. As a result, a more balanced and long-term effect on urban regeneration could be achieved.

Keywords: cultural event, urban regeneration, european capital of culture, Liverpool

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Authors: Upal Barua

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Crash risk at intersections is a critical safety issue. This paper examines the effectiveness of removing an existing off-set at an intersection by realignment, in reducing crashes. Empirical Bayes method was applied to conduct a before-and-after study to assess the effect of this safety improvement. The Transportation Safety Improvement Program in Austin Transportation Department completed several safety improvement projects at high crash intersections with a view to reducing crashes. One of the common safety improvement techniques applied was the realignment of intersection approaches removing an existing off-set. This paper illustrates how this safety improvement technique is applied at a high crash intersection from inception to completion. This paper also highlights the significant crash reductions achieved from this safety improvement technique applying Empirical Bayes method in a before-and-after study. The result showed that realignment of intersection approaches removing an existing off-set can reduce crashes by 53%. This paper also features the state of the art techniques applied in planning, engineering, designing and construction of this safety improvement, key factors driving the success, and lessons learned in the process.

Keywords: crash risk, intersection, off-set, safety improvement technique, before-and-after study, empirical Bayes method

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Authors: Amornnat Thuppia, Pornrut Rabintossaporn, Suphaket Saenthaweesuk, Nuntiya Somparn

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The aim of this present study was to determine the antioxidant effects and its mechanism of aqueous leaves extract of Bauhinia acuminata (BA) in rat. The extract was screened for its phytochemical contents and antioxidant activity in vitro. Moreover, the extract was studied in rats to evaluate its effects in vivo. Rats were orally administered with the extract at the dose of 50, 100 and 200 mg/kg for 28 days. Phytochemical screening of plant extracts showed the presence of saponin, alkaloid, cardiac glycosides, flavonoids, tannin and steroid compounds. The extract contained phenolic compounds 53.36 ± 1.01 mg of gallic acid equivalents per gram BA extract. The free radical scavenging activity assessed by DPPH assay gave IC50 of 44.47 ± 2.83 µg/mL, which is relatively lower than that of BHT with IC50 of 12.34 ± 1.14µg/mL. In the animals, the extract was well tolerated by the animals throughout the 28 days of study as shown by normal serum levels AST, ALP, ALT, BUN and Cr as well as normal histology of liver and pancreatic and kidney tissue. Significantly, reduction of serum oxidative stress markers malondialdehyde (MDA) was found in rat treated with BA extract compared with control. Taken together, this study provides evidence that Bauhinia acuminata (BA) exhibits direct antioxidant properties and induces cytoprotective enzyme in vivo.

Keywords: Bauhinia acuminata, antioxidant, malondialdehyde (MDA), oxidative marker

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Authors: Michael Alsop, Hannah Heitz, Prathiba Natesan Batley, Marion Hambrick, Jason Immekus

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The impacts of cultural engagement on individuals’ health and well-being have been well documented. The purposes of this study were to create an instrument to measure wellbeing constructs, including cultural wellbeing, and explore the relationships between cultural wellbeing and other wellbeing constructs (e.g., emotional, social, physical, spiritual). A sample of 358 participants attending concerts performed by a civic orchestra in the southeastern United States completed a questionnaire designed to measure eight wellbeing constructs. Split-half exploratory, confirmatory factor analyses resulted in the retention of four wellbeing constructs: general, emotional, financial, and cultural. Structural equation modeling showed statistically significant relationships between cultural wellbeing and other wellbeing constructs. In addition to the indirect effect of financial wellbeing on emotional and general wellbeing through cultural wellbeing, there were also direct statistically significant relationships (i.e., moderator). This highlights the importance of removing financial barriers to cultural engagement and the relationship between cultural wellbeing on emotional and general wellbeing. Additionally, the retained cultural wellbeing items focused primarily on community features, indicating the value of community-based cultural engagement opportunities.

Keywords: cultural wellbeing, cultural engagement, factor analysis, structural equation modeling

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Authors: Fatih Tarlak

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Predictive microbiology can be considered as an important field in food microbiology in which it uses predictive models to describe the microbial growth in different food products. Predictive models estimate the growth of microorganisms quickly, efficiently, and in a cost-effective way as compared to traditional methods of enumeration, which are long-lasting, expensive, and time-consuming. The mathematical models used in predictive microbiology are mainly categorised as primary and secondary models. The primary models are the mathematical equations that define the growth data as a function of time under a constant environmental condition. The secondary models describe the effects of environmental factors, such as temperature, pH, and water activity (aw) on the parameters of the primary models, including the maximum specific growth rate and lag phase duration, which are the most critical growth kinetic parameters. The combination of primary and secondary models provides valuable information to set limits for the quantitative detection of the microbial spoilage and assess product shelf-life.

Keywords: shelf-life, growth model, predictive microbiology, simulation

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Authors: Mohammad Zamzam, Wesam Bachir, Imad Asaad

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Several studies have produced estimates of Er:YAG laser parameters and specifications but there is still insufficient data for reliable selection of laser parameters. As a consequence, there is a heightened need for ideal specifications of Er:YAG laser to reduce the amount of enamel ablation. The objective of this paper is to investigate the influence of Er:YAG laser parameters, energy level and pulse duration, on orthodontic composite removal after bracket debonding. The sample consisted of 45 cuboids of orthodontic composite made by plastic moulds. The samples were divided into three groups, each was irradiated with Er:YAG laser set at different energy levels and three values for pulse durations (50 µs, 100 µs, and 300 µs). Geometrical parameters (depth and area) of cavities formed by laser irradiation were determined. ANCOVA test showed statistically significant difference (p < 0.0.5) between the groups indicating a potential effect of laser pulse duration on the geometrical parameters after controlling laser energy level. A post-hoc Bonferroni test ranked the 50µ Er:YAG laser pulse as the most influential factor for all geometrical parameters in removing remnant composite from enamel surface. Also, 300 mJ laser pulses caused the largest removal of the composite. The results of the present study demonstrated the efficacy of 50 µs and 300 mJ Er:YAG laser pulse for removal of remnant orthodontic composite.

Keywords: enamel, Er:YAG, geometrical parameters, orthodontic composite, remnant composite

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Authors: Nien-Te Kuo, Yi-Sung Cheng, Kuo-Chien Chang

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Cultural festival tourism is now seen by many as an opportunity to facilitate community development because it has significant influences on the economic, social, cultural, and political aspects of local communities. The potential for tourist attraction has been recognized as a useful tool to strengthen local economies from governments. However, most community festivals in Taiwan are short-lived, often only lasting for a few years or occasionally not making it past a one-off event. Researchers suggested that most governments and other stakeholders do not recognize the importance of building a partnership with residents when developing community tourism. Thus, the sustainable community tourism development still remains a key issue in the existing literature. The success of community tourism is related to the attitudes and lifestyles of local residents. In order to maintain sustainable tourism, residents need to be seen as development partners. Residents’ support intention for tourism development not only helps to increase awareness of local culture, history, the natural environment, and infrastructure, but also improves the interactive relationship between the host community and tourists. Furthermore, researchers have identified the social capital theory as the core of sustainable community tourism development. The social capital of residents has been seen as a good way to solve issues of tourism governance, forecast the participation behavior and improve support intention of residents. In addition, previous studies have pointed out the role of community participation and place identity in increasing resident support intention for tourism development. A lack of place identity is one of the main reasons that community tourism has become a mere formality and is not sustainable. It refers to how much residents participate during tourism development and is mainly influenced by individual interest. Scholars believed that the place identity of residents is the soul of community festivals. It shows the community spirit to visitors and has significant impacts on tourism benefits and support intention of residents in community tourism development. Although the importance of community participation and place identity have been confirmed by both governmental and non-governmental organizations, real-life execution still needs to be improved. This study aimed to use social capital theory to investigate the social structure between community residents, participation levels in festival tourism, degrees of place identity, and resident support intention for future community tourism development, and the causal relationship that these factors have with cultural festival tourism. A quantitative research approach was employed to examine the proposed model. Structural equation model was used to test and verify the proposed hypotheses. This was a case study of the Kaohsiung Zuoying Wannian Folklore Festival. The festival was located in the Zuoying District of Kaohsiung City, Taiwan. The target population of this study was residents who attended the festival. The results reveal significant correlations among social capital, community participation, place identity and support intention. The results also confirm that impacts of social capital on support intention were significantly mediated by community participation and place identity. Practical suggestions were provided for tourism operators and policy makers. This work was supported by the Ministry of Science and Technology of Taiwan, Republic of China, under the grant MOST-105-2410-H-328-013.

Keywords: community participation, place identity, social capital, support intention

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Authors: Marcela Parra-Vargas, Ana Sandoval-Rodriguez, Roberto Rodriguez-Echevarria, Jose Dominguez-Rosales, Juan Armendariz-Borunda

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Non-alcoholic fatty liver disease (NAFLD) is characterized by an excess of hepatic lipids, and it is to author’s best knowledge, the most prevalent chronic liver disorder. Anthocyanin-rich food consumption is linked to health benefits in metabolic disorders associated with obesity and NAFLD, although the precise functional role of anthocyanidin delphinidin (Dp) has yet to be established. The aim of this study was to investigate the effect of the Dp in NAFLD metabolic alterations by evaluating prevention or amelioration of hepatic lipid accumulation, as well as molecular mechanisms in two experimental obesity-related models of NALFD. In vitro: HepG2 cells were incubated with sodium palmitate (PA, 1 mM) to induce lipotoxic damage, and concomitantly treated with Dp (180 uM) for 24 h. Subsequently, total lipid accumulation was measured by colorimetric staining with Oil Red O, and total intrahepatic triglycerides were determined by an enzymatic assay. To assess molecular mechanisms, cells were pre-treated with PA for 24 h and then exposed to Dp for 1 h. In vivo: four-week-old male C57BL/6Nhsd mice were allocated in two main groups. Mice were fed with standard diet (control) or high-fat and high-carbohydrate diet (45% fat, HFD) for 16 wk to induce NAFLD. Then HFD was divided into subgroups: one treated orally with Dp (15 mg/kg bw, HFD-Dp) every day for 4 wk, while HFD group treated with vehicle (DMSO). Weight and fasting glucose were recorded weekly, while dietary ingestion was measured daily. Insulin tolerance test was performed at the end of treatment. Liver histology was evaluated with H&E and Masson’s trichrome stain. RT-PCR was used to evaluate gene expression and Western Blot to determine levels of protein in both experimental models. Parametric data were analyzed with one-way ANOVA and Tukey’s post-hoc test. Kruskal-Wallis and Mann-Whitney U test for non-parametric data, and P < 0.5 were considered significant. Dp prevented hepatic lipid accumulation by PA in HepG2 hepatocytes. Furthermore, Dp down-regulated gene expression of SREBP1c, FAS, and CPT1a without modifying AMPK phosphorylation levels. In vivo, Dp oral administration did not ameliorate lipid metabolic alterations raised by HFD. Adiposity, dietary ingestion, fasting glucose, and insulin sensitivity after Dp treatment remained similar to HFD group. Histological analysis showed hepatic damage in HFD groups and no differences between HFD and HFD-Dp groups were found. Hepatic gene expression of ACC and FAS were not altered by HFD. SREBP1c was similar in both HFD and HFD-Dp groups. No significant changes were observed in SREBP1c, ACC, and FAS adipose tissue gene expression by HFD or Dp treatment. Additionally, immunoblotting analysis revealed no changes in pathway SIRT1-LKB-AMPK and PPAR alpha by both HFD groups compared to control. In conclusion, the antioxidant Dp may provoke beneficial effects in the prevention of hepatic lipid accumulation. Nevertheless, the oral dose administrated in mice that simulated the total intake of anthocyanins consumed daily by humans has no effect as a treatment on hepatic lipid metabolic alterations and histological abnormalities associated with exposure to chronic HFD. A healthy lifestyle with regular intake of antioxidants such as anthocyanins may prevent metabolic alterations in NAFLD.

Keywords: anthocyanins, antioxidants, delphinidin, non-alcoholic fatty liver disease, obesity

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Authors: Hossein Shokouhmand, Seyyed Mostafa Saadat

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In this paper, the effect of thermal dispersion on the performance of plate heat exchangers (PHEs) with sinusoidal plates is investigated. In this regard, the PHE is considered as a porous medium. The important property of a porous medium is porosity that is defined as the total fluid volume divided by the total volume occupied by the solid and fluid. A 2D array of parallel sinusoidal plates with laminar periodically developed forced convection and single-phase constant property flows and conduction in a homogenous solid phase in two directions is considered. The array of flows is counter and the flows heat capacities are equal. Numerical study of conjugate heat transfer and axial conduction in the solid phase with different plate thicknesses showed that there is an optimal porosity in which the efficiency of heat transfer is up to 4% more than the time when the porosity is near one. It is shown that the optimal porosity at zero angle of inclination depends both on Reynolds number and the aspect ratio. The optimal porosity increased while either the Reynolds number or waviness of plates increased.

Keywords: plate heat exchanger, optimal porosity, efficiency, aspect ratio

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Authors: S. B. Kumbalavati, J. D. Mallapur, K. Y. Bendigeri

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A mobile Ad-hoc network (MANET) is a multihop wireless network where nodes communicate each other without any pre-deployed infrastructure. There is no central administrating unit. Hence, MANET is generally prone to many of the attacks. These attacks may alter, release or deny data. These attacks are nothing but intrusions. Intrusion is a set of actions that attempts to compromise integrity, confidentiality and availability of resources. A major issue in the design and operation of ad-hoc network is sharing the common spectrum or common channel bandwidth among all the nodes. We are performing intrusion detection using game theory approach. Game theory is a mathematical tool for analysing problems of competition and negotiation among the players in any field like marketing, e-commerce and networking. In this paper mathematical model is developed using game theory approach and intruders are detected and removed. Bandwidth utilization is estimated and comparison is made between bandwidth utilization with intrusion detection technique and without intrusion detection technique. Percentage of intruders and efficiency of the network is analysed.

Keywords: ad-hoc network, IDS, game theory, sensor networks

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Authors: Alime Cengiz, Talip Kahyaoglu

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Roasting process has the major importance to obtain desired aromatic taste of nuts. In this study, two kinds of roasting process were applied to hulled sesame seeds - vacuum oven and hot air roasting. Efficiency of Gene Expression Programming (GEP), a new soft computing technique of evolutionary algorithm that describes the cause and effect relationships in the data modelling system, and response surface methodology (RSM) were examined in the modelling of roasting processes over a range of temperature (120-180°C) for various times (30-60 min). Color attributes (L*, a*, b*, Browning Index (BI)), textural properties (hardness and fracturability) and moisture content were evaluated and modelled by RSM and GEP. The GEP-based formulations and RSM approach were compared with experimental results and evaluated according to correlation coefficients. The results showed that both GEP and RSM were found to be able to adequately learn the relation between roasting conditions and physical and textural parameters of roasted seeds. However, GEP had better prediction performance than the RSM with the high correlation coefficients (R2 >0.92) for the all quality parameters. This result indicates that the soft computing techniques have better capability for describing the physical changes occuring in sesame seeds during roasting process.

Keywords: genetic expression programming, response surface methodology, roasting, sesame seed

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Authors: Ferzat Anka

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Many types of problems can be solved using traditional analytical methods. However, these methods take a long time and cause inefficient use of resources. In particular, different approaches may be required in solving complex and global engineering problems that we frequently encounter in real life. The bigger and more complex a problem, the harder it is to solve. Such problems are called Nondeterministic Polynomial time (NP-hard) in the literature. The main reasons for recommending different metaheuristic algorithms for various problems are the use of simple concepts, the use of simple mathematical equations and structures, the use of non-derivative mechanisms, the avoidance of local optima, and their fast convergence. They are also flexible, as they can be applied to different problems without very specific modifications. Thanks to these features, it can be easily embedded even in many hardware devices. Accordingly, this approach can also be used in trend application areas such as IoT, big data, and parallel structures. Indeed, the metaheuristic approaches are algorithms that return near-optimal results for solving large-scale optimization problems. This study is focused on the new metaheuristic method that has been merged with the chaotic approach. It is based on the chaos theorem and helps relevant algorithms to improve the diversity of the population and fast convergence. This approach is based on Chimp Optimization Algorithm (ChOA), that is a recently introduced metaheuristic algorithm inspired by nature. This algorithm identified four types of chimpanzee groups: attacker, barrier, chaser, and driver, and proposed a suitable mathematical model for them based on the various intelligence and sexual motivations of chimpanzees. However, this algorithm is not more successful in the convergence rate and escaping of the local optimum trap in solving high-dimensional problems. Although it and some of its variants use some strategies to overcome these problems, it is observed that it is not sufficient. Therefore, in this study, a newly expanded variant is described. In the algorithm called Ex-ChOA, hybrid models are proposed for position updates of search agents, and a dynamic switching mechanism is provided for transition phases. This flexible structure solves the slow convergence problem of ChOA and improves its accuracy in multidimensional problems. Therefore, it tries to achieve success in solving global, complex, and constrained problems. The main contribution of this study is 1) It improves the accuracy and solves the slow convergence problem of the ChOA. 2) It proposes new hybrid movement strategy models for position updates of search agents. 3) It provides success in solving global, complex, and constrained problems. 4) It provides a dynamic switching mechanism between phases. The performance of the Ex-ChOA algorithm is analyzed on a total of 8 benchmark functions, as well as a total of 2 classical and constrained engineering problems. The proposed algorithm is compared with the ChoA, and several well-known variants (Weighted-ChoA, Enhanced-ChoA) are used. In addition, an Improved algorithm from the Grey Wolf Optimizer (I-GWO) method is chosen for comparison since the working model is similar. The obtained results depict that the proposed algorithm performs better or equivalently to the compared algorithms.

Keywords: optimization, metaheuristic, chimp optimization algorithm, engineering constrained problems

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Authors: M. Krishna

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The study was intended to identify if scalp cooling therapy is effective on preventing chemotherapy-induced hair loss among cancer patients. Critical literature of non-randomized controlled trials was used to investigate whether scalp cooling therapy is effective on preventing chemotherapy-induced alopecia. The review identified that scalp cooling therapy is effective on preventing chemotherapy-induced alopecia. Most of the patients receiving chemotherapy experience alopecia. It is also perceived as the worst effect of chemotherapy. This may be severe and lead the patients to withdraw the chemo treatment. The image disturbance caused by alopecia will make the patient depressed and will lead to declined immunity. With the knowledge on effectiveness of scalp cooling therapy on preventing chemotherapy-induced alopecia, patient undergoing chemotherapy will not be hesitant to undergo the treatment. Patients are recommended to go through scalp cooling therapy every chemo cycle and the proper therapy duration is 30 minutes before, during chemo. The suggested duration of the scalp cooling therapy is 45-90 minutes for an effective and positive outcome. This finding is excluding other factors of alopecia such as menopause, therapeutic drugs, poor hair density, liver function problems, and drug regimes.

Keywords: alopecia, cancer, chemotherapy, scalp cooling therapy

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Authors: Bimrisha Mali

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The present study investigates the type of errors English as a second language (ESL) learners produce using the definite article ‘the’. The participants were provided a questionnaire on the learner's ability test. The questionnaire consists of three cloze tests and two free composition tests. Each participant's response was received in the form of written data. A total of 78 participants from three government schools participated in the study. The participants are high-school students from Rural Assam. Assam is a north-eastern state of India. Their age ranged between 14-15. The medium of instruction and the communication among the students take place in the local language, i.e., Assamese. Pit Corder’s steps for conducting error analysis have been followed for the analysis procedure. Four types of errors were found (1) deletion of the definite article, (2) use of the definite article as modifiers as adjectives, (3) incorrect use of the definite article with singular proper nouns, (4) substitution of the definite article by the indefinite article ‘a’. Classifiers in Assamese that express definiteness is used with nouns, adjectives, and numerals. It is found that native language (L1) transfer plays a pivotal role in the learners’ errors. The analysis reveals the learners' inability to acquire the semantic connotation of definiteness in English due to native language (L1) interference.

Keywords: definite article error, l1 transfer, error analysis, ESL

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Authors: Aliasghar Baziar, Hassan Masoumi, Alireza Ale Saadi

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The control of the response of electric motors plays a significant role in the damping of transient responses. In this regard, this paper presents a static VAR compensator (SVC) based on a fuzzy logic which is applied to an industrial power network consisting of three phase synchronous, asynchronous and DC motor loads. The speed and acceleration variations of a specific machine are the inputs of the proposed fuzzy logic controller (FLC). In order to verify the effectiveness and proficiency of the proposed Fuzzy Logic based SVC (FLSVC), several non-linear time-domain digital simulation tests are performed. The proposed fuzzy model can properly control the response of electric motors. The results show that the FLSVC is successful to improve the voltage profile significantly over a wide range of operating conditions and disturbances thus improving the overall dynamic performance of the network.

Keywords: fuzzy logic controller, VAR compensator, single cage asynchronous motor, DC motor

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Authors: Fanqiang Kong, Chending Bian

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In this work, we exploit two assumed properties of the abundances of the observed signatures (endmembers) in order to reconstruct the abundances from hyperspectral data. Joint-sparsity is the first property of the abundances, which assumes the adjacent pixels can be expressed as different linear combinations of same materials. The second property is rank-deficiency where the number of endmembers participating in hyperspectral data is very small compared with the dimensionality of spectral library, which means that the abundances matrix of the endmembers is a low-rank matrix. These assumptions lead to an optimization problem for the sparse unmixing model that requires minimizing a combined l_2,p-norm and nuclear norm. We propose a variable splitting and augmented Lagrangian algorithm to solve the optimization problem. Experimental evaluation carried out on synthetic and real hyperspectral data shows that the proposed method outperforms the state-of-the-art algorithms with a better spectral unmixing accuracy.

Keywords: hyperspectral unmixing, joint-sparse, low-rank representation, abundance estimation

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Authors: Mohamed M. El Gendy, Ibrahim A. El Arabi, Rafeek W. Abdel-Missih, Omar A. Kandil

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Nonlinear analysis is one of the most important design and safety tools in structural engineering. Based on the finite-element method, a geometrical and material nonlinear analysis of large span reinforced concrete arches is carried out considering soil-structure interaction. The concrete section details and reinforcement distribution are taken into account. The behavior of soil is considered via Winkler's and continuum models. A computer program (NARC II) is specially developed in order to follow the structural behavior of large span reinforced concrete arches up to failure. The results obtained by the proposed model are compared with available literature for verification. This work confirmed that the geometrical and material nonlinearities, as well as soil structure interaction, have considerable influence on the structural response of reinforced concrete arches.

Keywords: nonlinear analysis, reinforced concrete arched structure, soil-structure interaction, geotechnical engineering

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Authors: Maizatulnisa Othman, Mohamad Bukhari, Zahurin Halim, Souad A. Muhammad, Khalisani Khalid

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Sandwich structure composites produced by epoxy core and aluminium skin were developed as potential building materials. Interface bonding between core and skin was controlled by varying kenaf content. Five different weight percentage of kenaf loading ranging from 10 wt% to 50 wt% were employed in the core manufacturing in order to study the mechanical properties of the sandwich composite. Properties of skin aluminium with epoxy were found to be affected by drying time of the adhesive. Mechanical behavior of manufactured sandwich composites in relation with properties of constituent materials was studied. It was found that 30 wt% of kenaf loading contributed to increase the flexural strength and flexural modulus up to 102 MPa and 32 Gpa, respectively. Analysis were done on the flatwise and edgewise compression test. For flatwise test, it was found that 30 wt% of fiber loading could withstand maximum force until 250 kN, with compressive strength results at 96.94 MPa. However, at edgewise compression test, the sandwich composite with same fiber loading only can withstand 31 kN of the maximum load with 62 MPa of compressive strength results.

Keywords: sandwich structure composite, epoxy, aluminium, kenaf fiber

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Authors: Amanda Cristina de Oliveira, Elias de Souza Monteiro Filho, Roberta Ceriani

Abstract:

Liquid-liquid extraction in aqueous two-phase systems (ATPSs) constitutes a powerful tool for purifying bio-materials, such as cells, organelles, proteins, among others. In this work, the extraction of the bovine serum albumin (BSA) has been studied in systems formed by polyethylene glycol (PEG) (1500, 4000, and 6000 g.mol⁻¹) + potassium sodium tartrate + water at 303.15°K. Phase diagrams were obtained by turbidimetry and Merchuk’s method (1998). The experimental tie-lines were described using the Othmer-Tobias and Bancroft correlations. ATPSs were correlated with the nonrandom two-liquid (NRTL) model. The results were considered excellent according to global root-mean-square deviations found which were between 0,72 and 1,13%. The concentrations of the proteins in each phase were determined by spectrophotometry at 280 nm, finding partition efficiencies greater than 71%.

Keywords: aqueous two phases systems, bovine serum albumin , liquid-liquid extraction, polyethylene glycol

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Authors: Changqiao Wu, Guoqing Ding, Xin Chen

Abstract:

In this paper, ways of modeling dynamic measurement systems are discussed. Specially, for linear system with single-input single-output, it could be modeled with shallow neural network. Then, gradient based optimization algorithms are used for searching the proper coefficients. Besides, method with normal equation and second order gradient descent are proposed to accelerate the modeling process, and ways of better gradient estimation are discussed. It shows that the mathematical essence of the learning objective is maximum likelihood with noises under Gaussian distribution. For conventional gradient descent, the mini-batch learning and gradient with momentum contribute to faster convergence and enhance model ability. Lastly, experimental results proved the effectiveness of second order gradient descent algorithm, and indicated that optimization with normal equation was the most suitable for linear dynamic models.

Keywords: dynamic system modeling, neural network, normal equation, second order gradient descent

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Authors: Shih-Ting Fu

Abstract:

This study aimed to investigate the influence of influencer marketing on fan satisfaction, purchase intention, and team identification. The research employed a questionnaire survey targeting the Chinese Professional Baseball League (CPBL). The sample included 205 participants, encompassing both existing CPBL fans and individuals with no prior baseball viewing habits. The survey assessed the impact of influencer marketing on participants' knowledge, attitudes, and behaviors related to the CPBL. Additionally, it evaluated team identification, fan satisfaction, and purchase intention. Data analysis using SPSS software aimed to identify correlations and effects among the variables. Findings revealed that influencer marketing has a significant positive impact on fan satisfaction, purchase intention, and team identification. Notably, further analysis indicated that the personal characteristics and charisma of influencers significantly influenced fans' perceptions, leading to increased purchase intention and satisfaction. This effect was even stronger than the influence of influencers' expertise and information dissemination regarding sports events or products.

Keywords: influencer marketing, fan satisfaction, team identification, purchase intention, Chinese professional baseball league (CPBL)

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Authors: N. Isnaini, S. Wahjuningsih

Abstract:

Fig fruit is the fruit of a tropical plant with content of flavanoids, vitamins A, C, and E which are antioxidants that effectively prevent and neutralize free radicals. This study was conducted to evaluate the supplementation of fig fruit extract in a physiological NaCl-based diluent on sperm motility and viability of native chicken semen after cooling. Semen was collected from 4 male mature chocks using massage method. Fresh semen evaluated for colour, pH, volume, concentration, mass motility, individual motility, life sperm and sperm abnormality. Semen was diluted with physiological NaCl-based extender supplemented with different levels of fig fruit extract (0, 10, 20 and 30 %) v/v with the ratio of 1 semen: 4 diluter. Semen used had mass motility of 2+ and motility of 70%. Immediately after dilution semen was stored in 3-5 °C and sperm motility and viability percentage were observed at 0, 12 and 24 h. The obtained data were analyze with Analysis of Variant (ANOVA) and Least Significant Difference were determined. The experiment was designed using completely random design (4 treatments and 10 replications). The results showed that the level of fig fruit extract had very significant effect (P < 0,01) on sperm motility and viability percentage in 0, 12 and 24 h of cooling. It can be concluded that the best fig fruit extract level for resulting optimal sperm motility and viability was 10%.

Keywords: chock, antioxidant, fig fruit extract, sperm

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Authors: Moudar Zgoul, Hashem Alkhaldi

Abstract:

A large number of transportable LPG cylinders are manufactured annually for domestic use. These LPG cylinders are manufactured from mild steel and filled maximally with 12.5 kg liquefied gas under internal pressure of 0.6 N/mm² at a temperature of 50°C. Many millions of such LPG cylinders are in daily use mainly, for purposes of space heating, water heating, and cooking. Thereby, they are imposed to severe conditions leading to their failure. Each year not less than 5000 of these LPG cylinders fail, some of those failures cause damage and loss in lives and properties. In this work, LPG cylinders were investigated; Stress calculations and deformations under dynamic (impact) loadings were carried out to simulate the effects of such loads on the cylinders while in service. Analysis of the LPG cylinders was carried out using the finite element method; shell and cylindrical elements were used at the top, bottom, and in middle (weld region), permitting elastic-plastic analysis for a thin-walled LPG cylinder. Variables such as maximum stresses and maximum deflections under the effect of impact loading were investigated in this work. Results showed that the maximum stresses reach 680 MPa when dropped from 3m-height. The maximum radial deformation occurs at the cylinder’s top in case of the top-position impact. This information should be useful for enhancing the strength of such cylinders and to for prolonging their service life.

Keywords: dynamic analysis, finite element method, impact load, LPG cylinders

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Authors: Samir Srairi

Abstract:

This paper investigates the impact of the internal corporate governance on bank performance by constructing a corporate governance index (CGI) for 27 Islamic banks operating in five Arab Gulf countries. Using content analysis on the banks’ annual reports for 3 years (2011-2013), the index construction uses information on six important corporate governance mechanisms, namely board structure, risk management, transparency and disclosure, audit committee, Sharia supervisory board and investment account holders. The results demonstrate that Islamic banks adhere to 54% of the attributes addressed in the CGI. The most frequently reported and disclosed elements are Sharia supervisory board followed by board structure and risk management. The findings related to countries revealed that only two countries, the United Arab Emirates and Bahrain, possess a higher level of CGI. Our regression results provide evidence that Islamic banks with higher levels of corporate governance report high operating performance measured by return on assets and net interest margin. Finally, as of the effect of internal and external factors, we identified four variables that were associated with bank performance, namely size, equity, risk and concentration.

Keywords: governance mechanisms, corporate governance index, bank performance, Islamic banks, GCC countries

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Authors: Marzia Hoque Tania, Oishy Roy, ASW Kurny, Fahmida Gulshan

Abstract:

This paper presents results of the investigation on the characterization of silica sand of northern region of Bangladesh on the basis of material composition, particle shape, and size, density, transportation, crystallinity, etc. before and after upgradation. The raw sand samples collected from Nilphamari and Lalmonirhat district were studied and compared for the prospect silica as a high valued commodity rather than heavy minerals. The raw sand particles were colorful in appearance with varying particle size distribution. Scanning Electron Microscopy (SEM) showed uniformity in grain size and mineralogical composition. X-ray fluorescence (XRF) analysis indicated the silica content of the as-received sample to be 75%. Thermogravimetric and Differential Thermal Analysis (DTA) did not detect the presence of any organic material. These tests revealed the sample to be alpha-quartz. Samples were washed with organic and inorganic acid with a combination of varying rotation speed, concentration, solid-liquid ratio. Experiments showed the silica content could be enhanced to more than 85% by washing with 15% sulphuric acid in room temperature. Beneficiation can be improved in further work considering the effect of varying temperature or advanced technology.

Keywords: beneficiation, characterization, commercial grade sand, glass sand, silica, upgradation

Procedia PDF Downloads 125