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Valorization of Wastes from Power Plant, Steel-Making and Palm Oil Industries as Partial Sand Substitute in Concrete
No full textFor long, the growing amount of solid wastes from various industries has created disposal issues and caused serious environmental concerns. Increased efforts have been carried out to recycle and valorize the industrial wastes into use as concrete-making materials. Due to the current growth of construction industries around the world, natural sand is depleting rapidly and as such raises environmental issues such as erosion, flooding and disruption of eco-system. Sourcing alternative materials to replace sand in concrete would be ideal in promoting sustainability for the environment as well as the construction industry. Therefore, this research explores the potential of utilizing local industrial wastes such as palm oil clinker from the palm oil industry, coal bottom ash from power plant as well as steel slag from the steel-making industry as partial sand substitute in concrete. Based on the tested concrete properties such as compressive strength, splitting tensile strength, sorptivity and shrinkage, it was found that incorporation of these industrial wastes at 50% replacement level generally did not cause substantial negative impact to the resulting concrete. In terms of the optimum concrete performance, it is suggested to incorporate these industrial wastes at 30% replacement level
Concurrent Mastoid Cellulitis and Langerhans Cells Histiocytosis: A Challenging Diagnosis
No full textLangerhans cell histiocytosis (LCH) is a rare proliferative disorder, which commonly arises in the bone and may involve other systems. To date, the diagnosis of temporal bone LCH remains a challenge as it may masquerade as a common ear infection. We report a case of a child who presented to us with persistent bilateral ear discharge for four months and was not responding to treatment. Her condition subsequently worsened, with clinical features and radiological findings suggestive of mastoid cellulitis. Nevertheless, further histopathology study revealed LCH
Treatment of Cotton by β-Cyclodextrin/Triclosan Inclusion Complex and Factors Affecting Antimicrobial Properties
No full textThe efficacy of antimicrobial treatment of cotton fabrics depends on various parameters of the coating process, such as the chemical nature and concentration of the antimicrobial agent, the composition of the crosslinking formulation, and the curing temperature. The inclusion complex of triclosan with β-cyclodextrin (βCD) was synthesized and characterized by FTIR, XRD, NMR, Raman, SEM, and TGA. The minimum inhibitory concentration and minimum bactericidal concentration of the complex against Klebsiella pneumoniae and Staphylococcus aureus were compared to those of its precursor. A multifactorial study included an evaluation of the effects of triclosan complexation with β-cyclodextrin, a comparison between the glyoxal and tetracarboxylic acid as crosslinkers, an investigation of the effect of crosslinker and catalyst concentrations, and a comparison of curing at 120°C and 180°C. The cotton was characterized by FTIR-ATR, the micrographs of treated samples were obtained by SEM and the weight add-on was calculated. The bactericidal properties were determined according to AATCC-147. The correlation between the coating process parameters and the antimicrobial efficacy was determined. The optimal combination leading to the highest weight add-on and the antimicrobial coating that was most durable to multiple detergent washes at an elevated temperature was the use of complexed triclosan grafted onto the cotton in the presence of tetracarboxylic acid, followed by curing at 180°C. The curing temperatures were 120°C (P=0.002) and 180°C (P=0.008), catalysts were 1 % and 2 % aluminium sulfate and sodium hypophosphite (P<0.001), and the crosslinkers were 5 % and 10 % glyoxal and butanetetracarboxylic acid (P<0.001); these parameters significantly enhanced the antimicrobial properties of the treated fabrics. The study showed that βCD did not have antimicrobial activity, while the βCD/triclosan-treated textile exhibited potential antimicrobial properties. Overall, the bactericidal activity of fabrics can be enhanced by using βCD/triclosan with 10 % butanetetracarboxylic acid as a cross-linker and 5 % sodium hypophosphite as a catalyst at a curing temperature of 180°C
A comparison of structural equation modeling approaches with DeLone & McLean's model: A case study of radio-frequency identification user satisfaction in Malaysian university libraries
No full textThis paper focuses on the application of mathematical theories in the study of information system (IS) success factors. The main objective is to apply Delone and McLean's IS success model for radio-frequency identification (RFID) sustainability in Malaysian university libraries. Two approaches are applied to estimate user satisfaction, such as the Bayesian and maximum likelihood estimation approaches. In order to identify the best approach, four mathematical indices are used, namely root mean squared error, absolute error, mean absolute percentage error, and the coefficient of determination. The results reveal that Bayesian estimation provides good fit to the data, unlike the model with the maximum likelihood estimator. This study addresses the causes for this difference between the two approaches, as well as the potential merits and shortcomings of the maximum likelihood approach. The current study presents a novel and practical modeling and prediction concept for researchers and experts in the field of computer science
Tobacco use and attitudes towards tobacco control activities of Malaysian dental students
No full textTobacco usage among dental students and the amount of training they received may have an impact on tobacco cessation activities undertaken for their patients. This study aims to assess Malaysian dental students' tobacco use, exposure to second-hand smoke and their attitude towards tobacco control activities and curriculum. This was a cross-sectional study using a self-administered questionnaire adapted from the Global Health Professions Students Survey (GHPSS). The questionnaire was distributed to all Malaysian fourth and fifth year dental students in four public dental schools (n=372), namely University of Malaya (UM), Universiti Teknologi Mara (UiTM), Universiti Kebangsaan Malaysia (UKM) and Universiti Sains Islam Malaysia (USIM). The data were analysed using descriptive and chi square tests. In total, (n=349) respondents completed the questionnaire, yielding a 93.8% response rate. Although the prevalence of Malaysian dental students who 'ever smoked' was 21.2%, the prevalence of current smokers was low (2.3%). About 62% and 39% of students reported having been exposed to second-hand smoke in public and at home, respectively. USIM students were significantly less likely to recall having received training about approaches to smoking cessation (52.9%, p < 0.001). Significantly fewer smokers than non-smokers agreed on tobacco banning policy. Regardless of their smoking status, the majority of dental students showed positive attitudes towards dentists' role in tobacco cessation. Tobacco user among Malaysian dental students was low. There were statistically significant differences between ever smokers and non-smokers' attitudes towards tobacco banning policy. The majority of dental students showed positive attitudes towards dentists' role in tobacco cessation
Features of Islamic Children’s Books in English: A Case Study of Books Published in Malaysia
No full textThe purpose of this study is to investigate the elements of Islamic children’s books that are written in English by focusing on books that are available in the Malaysian market and published in Malaysia. This study applies the content analysis method, by examining the selected books of their subject matter as well as the language. The results of the study reveal that Islamic books written for children in English are distinctive in terms of the content and language features
Improving Malaysian adolescent sexual and reproductive health: An Internet-based health promotion programme as a potential intervention
No full textObjective: Internet-based health promotion offers a promising approach to fostering healthy sexual behaviour among adolescents. The objective of this study was to identify the potential of an Internet-based programme to improve sexual and reproductive health (SRH) knowledge among Malaysian young people. Design: A pre-test/post-test design was used to study the potential of the Malaysian Care for Adolescent Project (MyCAP) website for online SRH education. Created by health professionals, the SRH module provides detailed and accurate information about the male and female reproductive systems, the stages of adolescent development, puberty (bodily development, menstruation and wet dreams), teenage pregnancy, sexually transmitted infections (STIs) and social situations such as avoiding premarital sex. Setting: A total of 209 young adolescents aged 12 years were recruited from a school in Lembah Pantai, Kuala Lumpur. Method: Students were randomly assigned to either an Internet-based or a conventional method group. The Internet-based intervention group consisted of 101 young people (50 boys and 51 girls), while the conventional method group consisted of 108 participants (62 boys and 46 girls). Results: Using the Internet-based method, there was an increase of 3.88 in the mean knowledge score of participants from pre- to post-intervention. The Internet-based method had a greater eta-squared score of 0.59 compared to the conventional method, which had an eta-squared score of 0.41 (p <.001). Conclusion: The results revealed that the Internet-based method significantly improved adolescents’ knowledge of SRH. Since the majority of students have access to the Internet, using online learning could provide an alternative educational method for teaching SRH
Tracking error plus damping injection control of non-minimum phase processes
No full textThis work proposes a passivity-based approach to deal with the output-tracking-error problem for a large class of nonlinear chemical processes including non-minimum phase systems. More precisely, in that framework, the system dynamics is firstly written into the relaxing (pseudo) port-Hamiltonian representation which does not necessarily require the positive semi-definite property of the damping matrix. Then, a reference trajectory associated with a certain structure passing through a desired equilibrium point (i.e., the set-point) is chosen so that the error dynamics can be globally asymptotically stabilized at the origin thanks to the assignment of an appropriate damping injection. This method is subsequently illustrated for a benchmark of multiple reactions systems, namely Van de Vusse reaction system. The numerical simulations show the applications of the proposed approach
Viral Load and Sequence Analysis Reveal the Symptom Severity, Diversity, and Transmission Clusters of Rhinovirus Infections
No full textBackground Rhinovirus (RV) is one of the main viral etiologic agents of acute respiratory illnesses. Despite the heightened disease burden caused by RV, the viral factors that increase the severity of RV infection, the transmission pattern, and seasonality of RV infections remain unclear. Methods An observational study was conducted among 3935 patients presenting with acute upper respiratory illnesses in the ambulatory settings between 2012 and 2014. Results The VP4/VP2 gene was genotyped from all 976 RV-positive specimens, where the predominance of RV-A (49%) was observed, followed by RV-C (38%) and RV-B (13%). A significant regression in median nasopharyngeal viral load (VL) (P <.001) was observed, from 883 viral copies/μL at 1-2 days after symptom onset to 312 viral copies/μL at 3-4 days and 158 viral copies/μL at 5-7 days, before declining to 35 viral copies/μL at ≥8 days. In comparison with RV-A (median VL, 217 copies/μL) and RV-B (median VL, 275 copies/μL), RV-C-infected subjects produced higher VL (505 copies/μL; P <.001). Importantly, higher RV VL (median, 348 copies/μL) was associated with more severe respiratory symptoms (Total Symptom Severity Score ≥17, P =.017). A total of 83 phylogenetic-based transmission clusters were identified in the population. It was observed that the relative humidity was the strongest environmental predictor of RV seasonality in the tropical climate. Conclusions Our findings underline the role of VL in increasing disease severity attributed to RV-C infection, and unravel the factors that fuel the population transmission dynamics of RV
Quasi-Solid Polymer Electrolyte Composed of poly(1-vinylpyrrolidone-co-vinyl acetate) Copolymer and the Influence of Its Composition on Electrochemical Properties and the Performances of Dye-Sensitized Solar Cells
No full textPoly(1-vinylpyrrolidone-co-vinyl acetate)-based quasi-solid polymer electrolytes doped with potassium iodide are prepared. The highest room temperature ionic conductivity of 1.72 mS cm−1 is obtained. The dielectric studies are performed to understand the ion conduction mechanism. Fourier transform infrared study has been performed to understand complexation of the poly(1-vinylpyrrolidone-co-vinyl acetate)-based quasi-solid polymer electrolytes. The best power energy conversion efficiency (η) obtained is 2.94% with short circuit current density (Jsc) of 8.05 mA cm−2, open circuit voltage (Voc) of 0.58 V, and fill factor of 63% under standard light intensity of 100 mW cm−2 irradiation