Search results for: ethical values

Authors: Meral Tuncbilek, Duygu Sac, Irem Durmaz, Rengul Cetin Atalay

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Nucleoside analogs are a pharmacologically diverse family that includes cytotoxic compounds, antiviral agents, and immunosuppressive molecules. Purine nucleoside derivatives such as fludarabine, cladribine, and pentostatin are significant drugs used in chemotherapy for the treatment of solid tumors and hematological malignancies. In this study, we synthesized novel purine ribonucleoside analogs containing a 4-(4-substituted phenylsulfonyl) piperazine in the substituent at N6- and O-substituted sulfonyl group at 5’-position as putative cytotoxic agents. The newly obtained compounds were then characterized for their cytotoxicity in human cancer cell lines. The 5’, 6-disubstituted 9-(β-D-ribofuranosyl)purine derivatives (44-67) were readily obtained from commercially available inosine in seven steps in very cost effective synthesis approach. The newly synthesized compounds were first evaluated for their anti-tumor activities against human liver (Huh7), colon (HCT116) and breast (MCF7) carcinoma cell lines. The IC50 values were in micromolar concentrations with 5’, 6-disubstituted purine nucleoside derivatives. Time-dependent IC50 values for each molecule were also calculated in comparison with known cytotoxic agents Camptothecin (CPT), 5-Fluorouracil (5-FU), Cladribine, Pentostatine and Fludarabine. N6-(4-trifluoromethyl phenyl) / N6-(4-bromophenyl) and 5’-O-(4-methoxybenzene sulfonyl) / 5’-O-(benzenesulfonyl) derivatives 54, 64 displayed the best cytotoxic activity with IC50 values of 8.8, 7 µM against MCF7 cell line. The N6-(4-methylphenyl) analog 50 was also very active (IC50= 10.7 μM) against HCT116 cell line. Furthermore, compound 64 had a better cytotoxic activity than the known cell growth inhibitors 5-FU and Fludarabine on Huh7 (1.5 vs 30.7, 29.9 μM for 5-FU and Fludarabine).

Keywords: cytotoxic activity, Huh7, HCT116, MCF7, nucleoside, synthesis

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Authors: Said Al Saifi

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This paper proposes a conceptual model for understanding the impact of organisational culture on knowledge management processes and their link with organisational performance. It is suggested that organisational culture should be assessed as a multi-level construct comprising artifacts, espoused beliefs and values, and underlying assumptions. A holistic view of organisational culture and knowledge management processes, and their link with organisational performance, is presented. A comprehensive review of previous literature was undertaken in the development of the conceptual model. Taken together, the literature and the proposed model reveal possible relationships between organisational culture, knowledge management processes, and organisational performance. Potential implications of organisational culture levels for the creation, sharing, and application of knowledge are elaborated. In addition, the paper offers possible new insight into the impact of organisational culture on various knowledge management processes and their link with organisational performance. A number of possible relationships between organisational culture factors, knowledge management processes, and their link with organisational performance were employed to examine such relationships. The research model highlights the multi-level components of organisational culture. These are: the artifacts, the espoused beliefs and values, and the underlying assumptions. Through a conceptualisation of the relationships between organisational culture, knowledge management processes, and organisational performance, the study provides practical guidance for practitioners during the implementation of knowledge management processes. The focus of previous research on knowledge management has been on understanding organisational culture from the limited perspective of promoting knowledge creation and sharing. This paper proposes a more comprehensive approach to understanding organisational culture in that it draws on artifacts, espoused beliefs and values, and underlying assumptions, and reveals their impact on the creation, sharing, and application of knowledge which can affect overall organisational performance.

Keywords: knowledge application, knowledge creation, knowledge management, knowledge sharing, organisational culture, organisational performance

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Authors: Saeed Talamkhani, Seyed Abolhassan Naeini

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In recent years, the occurrence of several liquefactions in sandy soils containing various values of clay content has shown that in addition to silty sands, clayey sands are also susceptible to liquefaction. Therefore, it is necessary to investigate the properties of these soil compositions and their behavioral characteristics. This paper presents the effect of clay fines on the undrained shear strength of sands at various confining pressures. For this purpose, a series of unconsolidated undrained triaxial shear tests were carried out on clean sand and sand mixed with 5, 10, 15, 20, and 30 percent of clay fines. It was found that the presence of clay particle in sandy specimens change the dilative behavior to contraction. The result also showed that increasing the clay fines up to 10 percent causes to increase the potential for liquefaction, and decreases it at higher values fine content. These results reveal the important role of clay particles in changing the undrained strength of the sandy soil.

Keywords: clayey sand, liquefaction, triaxial test, undrained shear strength

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Authors: Angie Al Habib, Khalid Al Siyabi

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To measure or asses any government’s efficiency we need to measure the performance of this government in regards to the quality of the service it provides. Using a technological platform in service provision became a trend and a public demand. It is also a public need to make sure these services are aligned to values and to the whole government’s strategy, vision and goals as well. Providing services using technology tools and channels can enhance the internal business process and also help establish many essential values to government services like transparency and excellence, since in order to establish e-services many standards and policies must be put in place to enable the handing over of decision making to a mature system oriented mechanism. There was no doubt that the Sultanate of Oman wanted to enhance its services and move it towards automation and establishes a smart government as well as links its services to life events. Measuring government efficiency is very essential in achieving social security and economic growth, since it can provide a clear dashboard of all projects and improvements. Based on this data we can improve the strategies and align the country goals to them.

Keywords: government, maturity, Oman, performance, service

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Authors: Pui-Lai To, E-Ping Sung

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With the flourishing development of online shopping, an increasing number of customers see online shopping as an entertaining experience. Because the online consumer has a double identity as a shopper and an Internet user, online shopping should offer hedonic values of shopping and Internet usage. The purpose of this study is to investigate hedonic online shopping motivations from the perspectives of traditional hedonic value and flow theory. The study adopted a focus group interview method, including two online and two offline interviews. Four focus groups of shoppers consisted of online professionals, online college students, offline professionals and offline college students. The results of the study indicate that traditional hedonic values and dimensions of flow theory exist in the online shopping environment. The study indicated that online shoppers seem to appreciate being able to learn things and grow to become competitive achievers online. Comparisons of online hedonic motivations between groups are conducted. This study serves as a basis for the future growth of Internet marketing.

Keywords: flow theory, hedonic motivation, internet shopping

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Authors: Su Yen Chen

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ChatGPT has shown both strengths and limitations in clinical, educational, and research settings, raising important concerns about accuracy, transparency, and ethical use. Despite an improved understanding of user acceptance and satisfaction, there is still a gap in how general AI perceptions translate into practical applications within healthcare. This study focuses on examining the perceptions of ChatGPT's impact among 266 healthcare majors in Taiwan, exploring its implications for their career development, as well as its utility in clinical practice, medical education, and research. By employing a structured survey with precisely defined subscales, this research aims to probe the breadth of ChatGPT's applications within healthcare, assessing both the perceived benefits and the challenges it presents. Additionally, to further enhance the comprehensiveness of our methodology, we have incorporated qualitative data collection methods, which provide complementary insights to the quantitative findings. The findings from the survey reveal that perceptions and usage of ChatGPT among healthcare majors vary significantly, influenced by factors such as its perceived utility, risk, novelty, and trustworthiness. Graduate students and those who perceive ChatGPT as more beneficial and less risky are particularly inclined to use it more frequently. This increased usage is closely linked to significant impacts on personal career development. Furthermore, ChatGPT's perceived usefulness and novelty contribute to its broader impact within the healthcare domain, suggesting that both innovation and practical utility are key drivers of acceptance and perceived effectiveness in professional healthcare settings. Trust emerges as an important factor, especially in clinical settings where the stakes are high. The trust that healthcare professionals place in ChatGPT significantly affects its integration into clinical practice and influences outcomes in medical education and research. The reliability and practical value of ChatGPT are thus critical for its successful adoption in these areas. However, an interesting paradox arises with regard to the ease of use. While making ChatGPT more user-friendly is generally seen as beneficial, it also raises concerns among users who have lower levels of trust and perceive higher risks associated with its use. This complex interplay between ease of use and safety concerns necessitates a careful balance, highlighting the need for robust security measures and clear, transparent communication about how AI systems work and their limitations. The study suggests several strategic approaches to enhance the adoption and integration of AI in healthcare. These include targeted training programs for healthcare professionals to increase familiarity with AI technologies, reduce perceived risks, and build trust. Ensuring transparency and conducting rigorous testing are also vital to foster trust and reliability. Moreover, comprehensive policy frameworks are needed to guide the implementation of AI technologies, ensuring high standards of patient safety, privacy, and ethical use. These measures are crucial for fostering broader acceptance of AI in healthcare, as the study contributes to enriching the discourse on AI's role by detailing how various factors affect its adoption and impact.

Keywords: ChatGPT, healthcare, survey study, IT adoption, behaviour, applcation, concerns

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Authors: Adrian O'Hagan, Robert McLoughlin

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Considerable focus in the world of insurance risk quantification is placed on modeling loss values from lines of business (LOBs) that possess upper tail dependence. Copulas such as the Joe, Gumbel and Student-t copula may be used for this purpose. The copula structure imparts a desired level of tail dependence on the joint distribution of claims from the different LOBs. Alternatively, practitioners may possess historical or simulated data that already exhibit upper tail dependence, through the impact of catastrophe events such as hurricanes or earthquakes. In these circumstances, it is not desirable to induce additional upper tail dependence when modeling the joint distribution of the loss values from the individual LOBs. Instead, it is of interest to accurately assess the degree of tail dependence already present in the data. The empirical copula and its associated upper tail dependence coefficient are presented in this paper as robust, efficient means of achieving this goal.

Keywords: empirical copula, extreme events, insurance loss reserving, upper tail dependence coefficient

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Authors: Zhang Xue

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Urban public green spaces have evolved from classical private gardens and have expanded into multi-dimensional space value attributes such as scale and property rights. Among them, ecological, environmental value, social interaction value, and commercial, economic value have become consensual value characteristics. From the perspective of institutional economics, urban public green spaces, as a type of non-exclusive and non-competitive public good, express the social connotation of spatial "publicness" and multiple values are its important attributes. However, due to the positive externality characteristics of public green spaces, the cost-benefit functions between subjects are inconsistent, leading to issues such as the "anti-commons tragedy" of transitional management, lack of public sense of space responsibility, and weakened public nature. It is necessary to enhance the "publicness" of urban public green spaces through effective institutional arrangements, inclusive planning participation, and humane management measures, promoting urban public openness and the enhancement of multiple values.

Keywords: public green spaces, publicness, governance, institutional economics

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Authors: Roza Dzierzak, Waldemar Wojcik, Piotr Kacejko

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Analysis of the texture of medical images consists of determining the parameters and characteristics of the examined tissue. The main goal is to assign the analyzed area to one of two basic groups: as a healthy tissue or a tissue with pathological changes. The CT images of the thoracic lumbar spine from 15 healthy patients and 15 with confirmed osteoporosis were used for the analysis. As a result, 120 samples with dimensions of 50x50 pixels were obtained. The set of features has been obtained based on the histogram, gradient, run-length matrix, co-occurrence matrix, autoregressive model, and Haar wavelet. As a result of the image analysis, 290 descriptors of textural features were obtained. The dimension of the space of features was reduced by the use of three selection methods: Fisher coefficient (FC), mutual information (MI), minimization of the classification error probability and average correlation coefficients between the chosen features minimization of classification error probability (POE) and average correlation coefficients (ACC). Each of them returned ten features occupying the initial place in the ranking devised according to its own coefficient. As a result of the Fisher coefficient and mutual information selections, the same features arranged in a different order were obtained. In both rankings, the 50% percentile (Perc.50%) was found in the first place. The next selected features come from the co-occurrence matrix. The sets of features selected in the selection process were evaluated using six classification tree methods. These were: decision stump (DS), Hoeffding tree (HT), logistic model trees (LMT), random forest (RF), random tree (RT) and reduced error pruning tree (REPT). In order to assess the accuracy of classifiers, the following parameters were used: overall classification accuracy (ACC), true positive rate (TPR, classification sensitivity), true negative rate (TNR, classification specificity), positive predictive value (PPV) and negative predictive value (NPV). Taking into account the classification results, it should be stated that the best results were obtained for the Hoeffding tree and logistic model trees classifiers, using the set of features selected by the POE + ACC method. In the case of the Hoeffding tree classifier, the highest values of three parameters were obtained: ACC = 90%, TPR = 93.3% and PPV = 93.3%. Additionally, the values of the other two parameters, i.e., TNR = 86.7% and NPV = 86.6% were close to the maximum values obtained for the LMT classifier. In the case of logistic model trees classifier, the same ACC value was obtained ACC=90% and the highest values for TNR=88.3% and NPV= 88.3%. The values of the other two parameters remained at a level close to the highest TPR = 91.7% and PPV = 91.6%. The results obtained in the experiment show that the use of classification trees is an effective method of classification of texture features. This allows identifying the conditions of the spongy tissue for healthy cases and those with the porosis.

Keywords: classification, feature selection, texture analysis, tree algorithms

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Authors: Zeid A. Alothman

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Silver nanoparticle (AgNP) has been synthesized using adrenaline. Adrenaline readily undergoes an autoxidation reaction in an alkaline medium with the dissolved oxygen to form adrenochrome, thus behaving as a mild reducing agent for the dissolved oxygen. This reducing behavior of adrenaline when employed to reduce Ag(+) ions yielded a large enhancement in the intensity of absorbance in the visible region. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) studies have been performed to confirm the surface morphology of AgNPs. Further, the metallic nanoparticles with size greater than 2 nm caused a strong and broad absorption band in the UV-visible spectrum called surface plasmon band or Mie resonance. The formation of AgNPs caused the large enhancement in the absorbance values with λmax at 436 nm through the excitation of the surface plasmon band. The formation of AgNPs was adapted to for the quantitative assessment of adrenaline using spectrophotometry with lower detection limit and higher precision values.

Keywords: silver nanoparticle, adrenaline, XRD, TEM, analysis

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Authors: Ovett Nwosimiri

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African tradition and what it entails are the content of African concepts of knowledge. The study of African concepts of knowledge is also known as African epistemology. In other words, African epistemology is a branch of African philosophy that deals with knowledge. This branch of African philosophy engages with the nature and concept of knowledge, the ways in which knowledge can be gained, the ways in which one can justify an epistemic claim or validate a knowledge claim and the limit of human knowledge, etc. The protagonists of African epistemology based their argument for a distinctive or unique African epistemology on the premise or proposition “that each race is endowed with a distinctive nature and embodies in its civilization a particular spirit”. All human beings share some certain basic values and perceptions irrespective of where you come from, and this idea actually fosters some forms of interaction between people from different nationality. Africans like other people share in some certain values, perceptions, and interaction with the rest of the world. These basic values, perceptions, and interaction that Africans share with the rest of the word prompted African people to attempt to “modernize” their societies or develop some forms of their tradition in harmony with the ethos of the contemporary world. Based on the above ideas, it would be interesting to investigate if such (African) epistemology is still unique. The advocates of African epistemology focus on the externalist notion of justification and neglect the idea that both the internalist and externalist notion of justification are needed in order to arrive at a coherent and well-founded account of epistemic justification. Thus, this paper will critically examine the claims that there is a unique African epistemology (a mode of knowing that is peculiar to Africans, and that African mode of knowing is social, monism and situated notion of knowledge), and the grounds for justifying beliefs and epistemic claims.

Keywords: internalist, externalist, knowledge, justification

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Authors: Gulcan Ozerim, Gunay Anlas

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In shape memory alloys, upon loading, stress increases around crack tip and a martensitic phase transformation occurs in early stages. In many studies the stress distribution in the vicinity of the crack tip is represented by using linear elastic fracture mechanics (LEFM) although the pseudo-elastic behavior results in a nonlinear stress-strain relation. In this study, the HRR singularity (Hutchinson, Rice and Rosengren), that uses Rice’s path independent J-integral, is tried to formulate the stress distribution around the crack tip. In HRR approach, the Ramberg-Osgood model for the stress-strain relation of power-law hardening materials is used to represent the elastic-plastic behavior. Although it is recoverable, the inelastic portion of the deformation in martensitic transformation (up to the end of transformation) resembles to that of plastic deformation. To determine the constants of the Ramberg-Osgood equation, the material’s response is simulated in ABAQUS using a UMAT based on ZM (Zaki-Moumni) thermo-mechanically coupled model, and the stress-strain curve of the material is plotted. An edge cracked shape memory alloy (Nitinol) plate is loaded quasi-statically under mode I and modeled using ABAQUS; the opening stress values ahead of the cracked tip are calculated. The stresses are also evaluated using the asymptotic equations of both LEFM and HRR. The results show that in the transformation zone around the crack tip, the stress values are much better represented when the HRR singularity is used although the J-integral does not show path independent behavior. For the nodes very close to the crack tip, the HRR singularity is not valid due to the non-proportional loading effect and high-stress values that go beyond the transformation finish stress.

Keywords: crack, HRR singularity, shape memory alloys, stress distribution

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Authors: Vikas Kumar

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The present study is carried out to investigate the magneto-viscous effects on incompressible ferrofluid flow over a porous rotating disc with suction or injection on the surface of the disc subjected to a magnetic field. The flow under consideration is axi-symmetric steady ferrofluid flow of electrically non-conducting fluid. Karman’s transformation is used to convert the governing boundary layer equations involved in the problem to a system of non linear coupled differential equations. The solution of this system is obtained by using power series approximation. The flow characteristics i.e. radial, tangential, axial velocities and boundary layer displacement thickness are calculated for various values of MFD (magnetic field dependent) viscosity and for different values of suction injection parameter. Besides this, skin friction coefficients are also calculated on the surface of the disk. Thus, the obtained results are presented numerically and graphically in the paper.

Keywords: axi-symmetric, ferrofluid, magnetic field, porous rotating disk

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Authors: Rasaq A. Kareem, Sulyman O. Salawu

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The study of Soret and Dufour effect on variable viscosity and thermal conductivity of an inclined magnetic field with dissipation in non-Darcy porous medium over a continuously stretching sheet for power-law variation in the sheet temperature and concentration are investigated. The viscosity of the fluid flow and thermal conductivity are considered to vary as a function of temperature. The local similarity solutions for different values of the physical parameters are presented for velocity, temperature and concentration. The result shows that variational increase in the values of Soret and Dufour parameters increase the temperature and concentration distribution. Finally, the effects of skin friction, Nusselt and Sherwood numbers which are of physical and engineering interest are considered and discussed.

Keywords: Dufour, non-Darcy Flow, Soret, thermal conductivity, variable viscosity

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Authors: Charlotte Jeavons, Charitini Stavropoulous, Nicolas Drey

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Background: Over one-third of five-year-olds and almost half of all eight-year-olds in the UK have obvious caries experience that can be detected by visual screening techniques. School-based caries preventions programs to apply fluoride varnish to young children’s teeth operate in many areas in the UK. Their aim is to reduce dental caries in children. The Department of Health guidance (2009) on consent states information must be provided to parents to enable informed autonomous decision-making prior to any treatment involving their young children. Fluoride varnish schemes delivered in primary schools use letters for this purpose. Parents are expected to return these indicating their consent or refusal. A large proportion of parents do not respond. In the absence of positive consent, these children are excluded from the program. Non-response is more common in deprived areas creating inequality. The reason for this is unknown. The consent process used is underpinned by the ethical theory of deontology that is prevalent in clinical dentistry and widely accepted in bio-ethics. Objective: To investigate parents’ views, understanding and experience of the fluoride varnish program taking place in their child’s school, including their views about the practical consent arrangements. Method: Schools participating in the fluoride varnish scheme operating in Enfield, North London, were asked to take part. Parents with children in nursery, reception, or year one were invited to participate via semi-structured interviews and focus groups. Thematic analysis was conducted. Findings: 40 parents were recruited from eight schools. The global theme of ‘trust’ was identified as the strongest influence on parental responses. Six themes were identified; protecting children from harm is viewed by parents as their role, parents have the capability to decide but lack confidence, sharing responsibility for their child’s oral health with the State is welcomed by a parent, existing relationships within parents’ social networks strongly influences consent decisions, official dental information is not communicated effectively, sending a letter to parents’ and excluding them from meeting dental practitioners is ineffective. The information delivered via a letter was not strongly identified by parents as influencing their response. Conclusions: Personal contact with the person(s) providing information and requesting consent has a greater impact on parental consent responses than written information provided alone. This demonstrates that traditional bio-ethical ideas about rational decision-making where emotions are transcended and interference is not justified unless preventing harm to an unaware person are outdated. Parental decision-making is relational and the consent process should be adapted to reflect this. The current system that has a deontology view of decision making at its core impoverishes parental autonomy and may, ultimately, increase dental inequalities as a result.

Keywords: consent, decision, ethics, fluoride, parents

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Authors: Nurfirdawati Muhamad Hanafi, Azmanirah Ab Rahman, Marina Ibrahim Mukhtar, Jamil Ahmad, Sarebah Warman

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This study was conducted to generate empirical evidence on validity and reliability of the item of Competency Assessment Implementation (CAI) Instrument using Rasch Model for polythomous data aided by Winstep software version 3.68. The construct validity was examined by analyzing the point-measure correlation index (PTMEA), in fit and outfit MNSQ values; meanwhile the reliability was examined by analyzing item reliability index. A survey technique was used as the major method with the CAI instrument on 156 teachers from vocational schools. The results have shown that the reliability of CAI Instrument items were between 0.80 and 0.98. PTMEA Correlation is in positive values, in which the item is able to distinguish between the ability of the respondent. Statistical data obtained shows that out of 154 items, 12 items from the instrument suggested to be omitted. This study is hoped could bring a new direction to the process of data analysis in educational research.

Keywords: competency assessment, reliability, validity, item analysis

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Authors: Elnaz Erfani, Elahe Erfni

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In this study, 96h LC50 values of dichromate potassium (K2Cr2O7), a highly toxicant heavy metal on sobaity seabream, Sparidebtex hasta of average weight mean weight 3.24 g; mean length 5.35cm was determined. At first, for rang finding test, fish were exposed to K2Cr2O7 at several selected concentrations 5, 10, 20, 30, 40, 50 and 60 mg/L, then fish exposed to five concentrations control, 40, 45, 50 and 55 mg/L of K2Cr2O7 for LC50-96h. The experiment was carried out in triplicate, and 21 fish per each treatment, Physicochemical properties of water were measured continuously throughout the experiment. The temperature, pH, dissolved oxygen and salinity were 26 ◦c, 7.05, 8.84 mgO2 L-1 and 37.5 ppt, respectively. A number of mortality and behavioral responses of fish were recorded after 24, 48, 72 and 96 h. LC50 values were determined with probate analysis. The 96 hour LC50 value of K2Cr2O7 to the fish was found to be 48.82 ppm. In addition, behavioural changes increased with increased concentration. The results obtained in this study clearly revealed the fact that it is necessary to control the use of a heavy metal such as dichromate potassium.

Keywords: marin fish- lc50, dicromat potassium, lc50, mortality

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Authors: Ahmed Arkoazi, Hussein Znad, Ranjeet Utikar

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The synergistic impact and optimization of gas flow rate, concentration of CO₂, and light intensity on CO₂ biofixation rate were investigated using wastewater as a medium to cultivate Chlorella vulgaris under different conditions (gas flow rate 1-8 L/min), CO₂ concentration (0.03-7%), and light intensity (150-400 µmol/m².s)). Response Surface Methodology and Box-Behnken experimental Design were applied to find optimum values for gas flow rate, CO₂ concentration, and light intensity. The optimum values of the three independent variables (gas flow rate, concentration of CO₂, and light intensity) and desirability were 7.5 L/min, 3.5%, and 400 µmol/m².s, and 0.904, respectively. The highest amount of biomass produced and CO₂ biofixation rate at optimum conditions were 5.7 g/L, 1.23 gL^-1d^-1, respectively. The synergistic effect between gas flow rate and concentration of CO₂, and between gas flow rate and light intensity was significant on the three responses, while the effect between CO₂ concentration and light intensity was less significant on CO₂ biofixation rate. The results of this study could be highly helpful when using microalgae for CO₂ biofixation in wastewater treatment.

Keywords: bubble column reactor, gas holdup, hydrodynamics, sparger

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Authors: Amel Hamma, Allesandro Pegoretti

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Kenaf fibres, with two aspect ratios, were melt compounded with two types of biopolymers named starch grafted polypropylene, and then blends compression molded to form plates of 1 mm thick. Results showed that processing induced variation of fibres length which is quantified by optical microscopy observations. Young modulus, stress at break and impact resistance values of starch-grafted-polypropylenes were remarkably improved by kenaf fibres for both matrixes and demonstrated best values when G906PJ were used as matrix. These results attest the good interfacial bonding between the matrix and fibres even in the absence of any interfacial modification. Vicat Softening Point and storage modules were also improved due to the reinforcing effect of fibres. Moreover, short-term tensile creep tests have proven that kenaf fibres remarkably improve the creep stability of composites. The creep behavior of the investigated materials was successfully modeled by the four parameters Burgers model.

Keywords: creep behaviour, kenaf fibres, mechanical properties, starch-grafted-polypropylene

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Authors: Nizar Souiden, Riadh Ladhari

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Like tobacco and alcohol, recreational marijuana falls under the umbrella of ‘sin’ industries’. Notwithstanding this general negative image surrounding marijuana use, some scholars argue that most of the widely believed claims made about recreational marijuana users are irrelevant and that marijuana use can even improve individuals’ decision-making. This study intends to shed light on this particular product category (i.e., marijuana) often overlooked or portrayed as taboo from a business view. More specifically, it investigates whether legalizing the consumption of recreational marijuana would be perceived as ethical and whether companies/organizations involved in the commercialization of this particular product would be held socially responsible. Based on primary data collected in Canada, this study aims to answer the following questions: 1) What moral thoughts do individuals hold with regard to the consumption of recreational marijuana? 2) How do these moral thoughts determine consumers’ attitude toward the consumption of recreational marijuana? Regardless of the legalization of recreational marijuana in some countries such as Canada, probing people’s opinions, and investigating their attitudes toward the consumption of recreational marijuana is of important interest to different stakeholders such as consumers, public organizations, private businesses, and trade associations.

Keywords: recreational marijuana, moral thoughts, ethics, attitude

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Authors: Mustafa M. Donma, Orkide Donma

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The impact of metabolic syndrome (MetS) on cognition and functions of the brain is being investigated. Iron deficiency and deficiencies of B9 (folate) as well as B12 (cobalamin) vitamins are best-known nutritional anemias. They are associated with cognitive disorders and learning difficulties. The antidepressant effects of vitamin D are known and the deficiency state affects mental functions negatively. The aim of this study is to investigate possible correlations of MetS with serum brain-derived neurotrophic factor (BDNF), iron, folate, cobalamin and vitamin D in pediatric patients. 30 children, whose age- and sex-dependent body mass index (BMI) percentiles vary between 85 and 15, 60 morbid obese children with above 99^th percentiles constituted the study population. Anthropometric measurements were taken. BMI values were calculated. Age- and sex-dependent BMI percentile values were obtained using the appropriate tables prepared by the World Health Organization (WHO). Obesity classification was performed according to WHO criteria. Those with MetS were evaluated according to MetS criteria. Serum BDNF was determined by enzyme-linked immunosorbent assay. Serum folate was analyzed by an immunoassay analyzer. Serum cobalamin concentrations were measured using electrochemiluminescence immunoassay. Vitamin D status was determined by the measurement of 25-hydroxycholecalciferol [25-hydroxy vitamin D3, 25(OH)D] using high performance liquid chromatography. Statistical evaluations were performed using SPSS for Windows, version 16. The p values less than 0.05 were accepted as statistically significant. Although statistically insignificant, lower folate and cobalamin values were found in MO children compared to those observed for children with normal BMI. For iron and BDNF values, no alterations were detected among the groups. Significantly decreased vitamin D concentrations were noted in MO children with MetS in comparison with those in children with normal BMI (p ≤ 0.05). The positive correlation observed between iron and BDNF in normal-BMI group was not found in two MO groups. In THE MetS group, the partial correlation among iron, BDNF, folate, cobalamin, vitamin D controlling for waist circumference and BMI was r = -0.501; p ≤ 0.05. None was calculated in MO and normal BMI groups. In conclusion, vitamin D should also be considered during the assessment of pediatric MetS. Waist circumference and BMI should collectively be evaluated during the evaluation of MetS in children. Within this context, BDNF appears to be a key biochemical parameter during the examination of obesity degree in terms of mental functions, cognition and learning capacity. The association observed between iron and BDNF in children with normal BMI was not detected in MO groups possibly due to development of inflammation and other obesity-related pathologies. It was suggested that this finding may contribute to mental function impairments commonly observed among obese children.

Keywords: brain-derived neurotrophic factor, iron, vitamin B9, vitamin B12, vitamin D

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Authors: Vivek Upadhayay, Siddharth Deshmukh

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In recent years utilization of renewable energy sources has increased majorly because of the increase in global warming concerns. Organization these days are generally operated by Micro grid or smart grid on a small level. Power optimization and optimal load tripping is possible in a smart grid based industry. In any plant or industry loads can be divided into different categories based on their importance to the plant and power requirement pattern in the working days. Coming up with an idea to divide loads in different such categories and providing different power management algorithm to each category of load can reduce the power cost and can come handy in balancing stability and reliability of power. An objective function is defined which is subjected to a variable that we are supposed to minimize. Constraint equations are formed taking difference between the power usages pattern of present day and same day of previous week. By considering the objectives of minimal load tripping and optimal power distribution the proposed problem formulation is a multi-object optimization problem. Through normalization of each objective function, the multi-objective optimization is transformed to single-objective optimization. As a result we are getting the optimized values of power required to each load for present day by use of the past values of the required power for the same day of last week. It is quite a demand response scheduling of power. These minimized values then will be distributed to each load through an algorithm used to optimize the power distribution at a greater depth. In case of power storage exceeding the power requirement, profit can be made by selling exceeding power to the main grid.

Keywords: power flow optimization, power trading enhancement, smart grid, multi-object optimization

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Authors: Abdullah Ay, Şehnaz Şener

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It is of great importance to reveal their current status and conduct research in this direction for the sustainable use and protection of lakes, which are among the most important water resources for meeting water needs and ensuring ecological balance. In this context, the purpose of this study is to determine the hydrogeochemical properties, as well as water quality and usability characteristics of Işıklı Lake within the Lakes Region of Turkey. Işıklı Lake is a tectonic lake located in the Aegean Region of Turkey. The lake has a surface area of approximately 36 km². Temperature (T), electrical conductivity (EC) and hydrogen ion concentration (pH), dissolved oxygen (%, mg/l), Oxidation Reduction Potential (ORP; mV), and amount of dissolved solids in water (TDS; mg/l) of water samples taken from the lake values were determined by in situ analysis. Major ion and heavy metal analyses were carried out under laboratory conditions. Additionally, the relationship between major ion concentrations and TDS values of Işıklı Lake water samples was determined by correlation analysis. According to the results obtained, it is seen that especially Mg, Ca and HCO₃ ions are dominant in the lake water, and it has been determined that the lake water is in the Ca-Mg-HCO₃ water facies. According to statistical analysis, a strong and positive relationship was found between the TDS value and bicarbonate and calcium (R² = 0.61 and 0.7, respectively). However, no significant relationship was detected between the TDS value and other chemical elements. Although the waters are generally in water quality class I, they are in class IV in terms of sulfur and aluminum. It is included in the water quality class. This situation is due to the rock-water interaction in the region. When the analysis results of the lake water were compared with the drinking water limit values specified by TSE-266 (2005) and WHO (2017), it was determined that it was not suitable for drinking water use in terms of Pb, Se, As, and Cr. When the waters were evaluated in terms of pollution, it was determined that 50% of the samples carried pollution loads in terms of Al, As, Fe, NO3, and Cu.

Keywords: Işıklı Lake, water chemistry, water quality, pollution, arsenic, Denizli

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Authors: Emad Rashwan, M. Mousa, Ayman EL Sabagh, Celaleddin Barutcular

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Flax is a potential winter crop for Egypt that can be grown for both seed and fiber. The study was conducted during two successive winter seasons of 2013/2014, and 2014/2015 in the experimental farm of El-Gemmeiza Agricultural Research Station, Agriculture research Centre, Egypt. The objective of this work was to evaluate the effect of irrigation intervals (25, 35 and 45) on the seed yield and quality of flax cultivars (Sakha1, Giza9 and Giza10). Obtained results indicate that highly significant for all studied traits among irrigation intervals except oil percentage that was not significant in both seasons. Irrigated flax plants every 35 days gave the maximum values for all characters. In contrast, irrigation every 45 days gave the minimum values for all studied characters under this study. In respect to cultivars, significant differences in most yield and quality characters were found. Furthermore, the performance of Sakha1 cultivar was superior in total plant height, main stem diameter, seed index, seed, oil, biological and straw yield /ha as well as fiber length and fiber fineness. Meanwhile, Giza9 and Giza10 cultivars were surpassed in fiber yield/hand fiber percentage, respectively. The interactions between irrigation intervals and flax cultivars were highly significant for total plant height, main stem diameter, seed, oil, biological and straw yields /ha. Based on the results, all flax cultivars recorded the maximum values for major traits were measured under irrigation of flax plants every 35 days.

Keywords: flax, fiber, irrigation intervals, oil, seed yield

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Authors: Ahmed Ghachem, Johann Colomba, Denis Prud'homme, Martin Brochu

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Background: Inactive obese postmenopausal women, are at greater risk for metabolic complications. On the other hand, high levels of cardiorespiratory fitness (CRF) are associated with a lower risk of metabolic complications. Objective: To compare inactive obese postmenopausal women displaying ‘lower’ vs ‘higher’ levels of CRF for body composition, metabolic profile, inflammatory profile and measures of energy expenditure. Methods: 132 women (age: 57.6 ± 4.8 yrs; BMI: 32.3 ± 4.6 kg/m2; Peak VO2: 17.81 ± 3.02 ml O2•kg-1•min-1) were studied. They were first divided into tertiles based on their CRF. Then, women in the first (< 16.51 ml O2•min-1•kg-1) and second tertiles (16.51 to 19.22 ml O2•min-1•kg-1) were combined (N= 88), and compared with those in the third tertile (> 19.22 ml O2•min-1•kg-1) (N= 44). Variables of interest were: Peak VO2 (stationary bike), body composition (DXA), body fat distribution (CT scan), glucose homeostasis (fasting state and euglycemic/ hyperinsulinemic clamp), fasting lipids, resting blood pressure, inflammatory profile and energy expenditure (DLW). Results: Both CRF groups (lower= 16.0 ± 2.0 ml O2•kg-1•min-1 vs higher= 21.2 ± 1.7 ml O2•kg-1•min-1; p < 0.001) were similar for age. Significant differences were observed between groups for body composition; with lower values for body weight, BMI, fat mass and visceral fat in women with higher CRF (p between 0.001 and 0.005). Also, women with higher CRF had lower values for fasting insulin (13.4 ± 4.5 vs 15.6 ± 6.6 μU/ml; p = 0.03) and CRP levels (2.31 ± 1.97 vs 3.83 ± 3.24 mg/liter; p = 0.001); and higher values for glucose disposal (6.71 ± 1.78 vs 5.92 ± 1.67 mg/kg/min; p = 0.01). However, these differences were no longer significant after controlling for visceral adipose tissue accumulations. Finally, no significant difference was observed between groups for the other variables of interest. Conclusion: Our results suggest that, among inactive overweight/obese postmenopausal women, those with higher CRF levels have a better metabolic profile; which is caused by lower visceral fat accumulations.

Keywords: cardiorespiratory fitness, metabolic profile, menopause, obesity

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Authors: E. Hovad, J. H. Walther, P. Larsen, J. Thorborg, J. H. Hattel

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In sand casting of metal parts for the automotive industry such as brake disks and engine blocks, the molten metal is poured into a sand mold to get its final shape. The DISAMATIC molding process is a way to construct these sand molds for casting of steel parts and in the present work numerical simulations of this process are presented. During the process green sand is blown into a chamber and subsequently squeezed to finally obtain the sand mould. The sand flow is modelled with the Discrete Element method (DEM) and obtaining the correct material parameters for the simulation is the main goal. Different tests will be used to find or calibrate the DEM parameters needed; Poisson ratio, Young modulus, rolling friction coefficient, sliding friction coefficient and coefficient of restitution (COR). The Young modulus and Poisson ratio are found from compression tests of the bulk material and subsequently used in the DEM model according to the Hertz-Mindlin model. The main focus will be on calibrating the rolling resistance and sliding friction in the DEM model with respect to the behavior of “real” sand piles. More specifically, the surface profile of the “real” sand pile will be compared to the sand pile predicted with the DEM for different values of the rolling and sliding friction coefficients. When the DEM parameters are found for the particle-particle (sand-sand) interaction, the particle-wall interaction parameter values are also found. Here the sliding coefficient will be found from experiments and the rolling resistance is investigated by comparing with observations of how the green sand interacts with the chamber wall during experiments and the DEM simulations will be calibrated accordingly. The coefficient of restitution will be tested with different values in the DEM simulations and compared to video footages of the DISAMATIC process. Energy dissipation will be investigated in these simulations for different particle sizes and coefficient of restitution, where scaling laws will be considered to relate the energy dissipation for these parameters. Finally, the found parameter values are used in the overall discrete element model and compared to the video footage of the DISAMATIC process.

Keywords: discrete element method, physical properties of materials, calibration, granular flow

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Authors: Huseyin Canci

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Chlorophylls are green photosynthetic pigment in plants. Therefore, photosynthesis in plants occurs in the leaves. Roles of chlorophylls help plants to get energy from light. The aim of the present study is to compare of chlorophyll contents in some bean species including common bean (Phaseolus vulgaris L.) and runner bean (P. coccineous L.) and genotypes. This research was carried out in fields of Faculty of Agriculture, Akdeniz University in Antalya. Species and genotypes were grown in 2 m single row and 50 cm row spacing. A randomized blocks design was used with two replications. Totally, 124 beans species and genotypes which 122 common beans and 2 runner beans were sown on February, 17th 2014 by hand. Chlorophyll a + b (SPAD values) were determined seedling stage, days to flowering 50% and pod setting stage on bean genotypes. Results showed that there were significant differences for genotypes, stages and interaction of genotypes X stages. There was statistically significant relationships between yield and chlorophyll content of bean species and genotypes.

Keywords: bean, chlorophyll, Phaseolus, SPAD values

Procedia PDF Downloads 237

Authors: Mohammed H. Rady, Mohd Sukri Mustapa, S Shamsudin, M. A. Lajis, A. Wagiman

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The present study is aimed at investigating microhardness and density of aluminium alloy chips when subjected to various settings of preheating temperature and preheating time. Three values of preheating temperature were taken as 450 °C, 500 °C, and 550 °C. On the other hand, three values of preheating time were chosen (1, 2, 3) hours. The influences of the process parameters (preheating temperature and time) were analyzed using Design of Experiments (DOE) approach whereby full factorial design with center point analysis was adopted. The total runs were 11 and they comprise of two factors of full factorial design with 3 center points. The responses were microhardness and density. The results showed that the density and microhardness increased with decreasing the preheating temperature. The results also found that the preheating temperature is more important to be controlled rather than the preheating time in microhardness analysis while both the preheating temperature and preheating time are important in density analysis. It can be concluded that setting temperature at 450 °C for 1 hour resulted in the optimum responses.

Keywords: AA6061, density, DOE, hot extrusion, microhardness

Procedia PDF Downloads 345

Authors: Shreya Srivastava, Sushovan Ghosh, Sagnik Dey

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Aerosols directly affect Earth’s radiation budget by scattering and absorbing incoming solar radiation and outgoing terrestrial radiation. While the uncertainty in aerosol radiative forcing (ARF) has decreased over the years, it is still higher than that of greenhouse gas forcing, particularly in the South Asian region, due to high heterogeneity in their chemical properties. Understanding the Spatio-temporal heterogeneity of aerosol composition is critical in improving climate prediction. Studies using satellite data, in-situ and aircraft measurements, and models have investigated the Spatio-temporal variability of aerosol characteristics. In this study, we have taken aerosol data from Multi-angle Imaging Spectro-Radiometer (MISR) level-2 version 23 aerosol products retrieved at 4.4 km and radiation data from Clouds and the Earth’s Radiant Energy System (CERES, spatial resolution=1ox1o) for 21 years (2000-2021) over the Indian subcontinent. MISR aerosol product includes size and shapes segregated aerosol optical depth (AOD), Angstrom exponent (AE), and single scattering albedo (SSA). Additionally, 74 aerosol mixtures are included in version 23 data that is used for aerosol speciation. We have seasonally mapped aerosol optical and microphysical properties from MISR for India at quarter degrees resolution. Results show strong Spatio-temporal variability, with a constant higher value of AOD for the Indo-Gangetic Plain (IGP). The contribution of small-size particles is higher throughout the year, spatially during winter months. SSA is found to be overestimated where absorbing particles are present. The climatological map of short wave (SW) ARF at the top of the atmosphere (TOA) shows a strong cooling except in only a few places (values ranging from +2.5o to -22.5o). Cooling due to aerosols is higher in the absence of clouds. Higher negative values of ARF are found over the IGP region, given the high aerosol concentration above the region. Surface ARF values are everywhere negative for our study domain, with higher values in clear conditions. The results strongly correlate with AOD from MISR and ARF from CERES.

Keywords: aerosol Radiative forcing (ARF), aerosol composition, single scattering albedo (SSA), CERES

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Authors: Mehmet Yavuz Hüseyinca, Şuayip Küpeli

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Sandstones from Upper Eocene - Oligocene Tepeköy formation (Member of Mezgit Group) that exposed on the eastern edge of Tuz Gölü (Salt Lake) were analyzed for their rare earth element (REE) contents. Average concentrations of ΣREE, ΣLREE (Total light rare earth elements) and ΣHREE (Total heavy rare earth elements) were determined as 31.37, 26.47 and 4.55 ppm respectively. These values are lower than UCC (Upper continental crust) which indicates grain size and/or CaO dilution effect. The chondrite-normalized REE pattern is characterized by the average ratios of (La/Yb)cn = 6.20, (La/Sm)cn = 4.06, (Gd/Lu)cn = 1.10, Eu/Eu* = 0.99 and Ce/Ce* = 0.94. Lower values of ΣLREE/ΣHREE (Average 5.97) and (La/Yb)cn suggest lower fractionation of overall REE. Moreover (La/Sm)cn and (Gd/Lu)cn ratios define less inclined LREE and almost flat HREE pattern when compared with UCC. Almost no Ce anomaly (Ce/Ce*) emphasizes that REE were originated from terrigenous material. Also depleted LREE and no Eu anomaly (Eu/Eu*) suggest an undifferentiated mafic provenance for the sandstones.

Keywords: central Anatolia, provenance, rare earth elements, REE, Tepeköy sandstone

Procedia PDF Downloads 466