19672 research outputs found
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Improved visible-light photocatalytic activity of TiO 2 co-doped with copper and iodine
No full textCu-I-co-doped TiO 2 photocatalysts active to visible light absorption were prepared by hydrothermal method and calcined at various temperatures (350 °C, 450 °C, and 550 °C). The co-doped powders at 350 °C displayed the highest experimental Brunauer–Emmett–Teller surface area and lowest photoluminescence intensity, which demonstrated that a decrease in electron–hole recombination process. The synthesis of co-doped TiO 2 was performed at this optimized temperature. In the co-doped sample, the Cu 2+ doped TiO 2 lattice created a major “red-shift” in the absorption edge due to the presence of the 3d Cu states, whereas the amount of red-shift from the I 5+ doping in the TiO 2 lattice was minor. Interestingly, the presence of Cu 2+ species also boosted the reduction of I 5+ ions to the lower multi-valance state I − in the TiO 2 lattice by trapping the photogenerated electrons, which resulted in effective separation of the photogenerated charges. The Cu-I-co-doped TiO 2 was able to degrade methyl orange dye under visible-light irradiation with improved photocatalytic activity compared with the single metal-doped TiO 2 and pure TiO 2 because of the strong visible light absorption and effective separation of photogenerated charges caused by the synergistic effects of Cu and I co-dopants
Harmonization of food trade standards and regulations in ASEAN: the case of Malaysia's food imports
No full textRegulatory heterogeneity continues to be identified as a challenge for food trade in the Association of Southeast Asian Nations (ASEAN) as the progress of harmonization of food standards among member states remains slow. Using a new and comprehensive database on nontariff measures (NTMs), this article examines the coverage, frequency, and diversity of NTMs for the food sector in Malaysia, and then estimates their impact on food imports from ASEAN. The food sector in Malaysia is found to be highly regulated, dominated by technical measures, namely, labeling for sanitary and phytosanitary and technical barriers to trade reasons, product quality, and restricted substances. The empirical results subsequently verify that, overall, technical measures are import restrictive. This article therefore contends that harmonization of food standards and regulations at the regional level is important for enhancing trade. However, building common ground for food safety regulations should be NTM- and sector-specific, to realize progress in terms of regulatory convergence. This is particularly true for the food sector, since complete harmonization is not practical and not politically feasible
A facile chemical route synthesis and characterization of CdSe/ZnO nanocomposite
No full textThe controlled synthesis of CdSe/ZnO-nanocomposite fabrication by facile chemical route has been successfully performed. Crystalline structure was examined by XRD patterns, while the morphology was investigated was carried out using typical electron microscopic investigations of SEM and HR-TEM equipped with electron dispersion spectroscopy (EDS) analogous to the detection of chemical elements in hybrid composite. The typical SEM image of fabricated CdSe/ZnO-nanomaterial and the grain size was found to 12 nm. The elemental composition of CdSe/ZnO-nanomaterial was analyzed by energy dispersive X-ray spectrometry (EDS). The HR-TEM images of CdSe/ZnO NPs confirm the agglomerated particles neck with their neighbors and form hexagonal shapes. The UV–visible absorption spectroscopy was used to analyze the optical properties. From UV absorption spectrum, a broad peak at 405 nm was observed. The photoluminescence (PL) spectrum was also used to determine the optical properties. The PL spectrum shows the maximum was slightly red-shifted to 625 nm. At various frequencies and at an ambient condition of temperatures, the dielectric studies such as dielectric constant, dielectric loss and AC conductivity properties were investigated. Furthermore, we have studied the current density–voltage of CdSe/ZnO-nanocomposite
Prevalence of malnutrition and associated factors among community-dwelling older persons in Sri Lanka: a cross-sectional study
No full textBackground: Malnutrition in older persons is a public health concern. This study aimed to estimate the prevalence of malnutrition and its associated factors among community-dwelling older persons in Sri Lanka. Methods: A cross-sectional study was conducted in the Kandy district, Sri Lanka. The nutritional status of older persons was assessed using the Mini Nutritional Assessment -Short Form (MNA-SF). A standardised questionnaire was used to record factors associated with malnutrition: demographic characteristics, financial characteristics, food and appetite, lifestyle, psychological characteristics, physical characteristics, disease and care, oral health, and social factors. Complex sample multinomial logistic regression analysis was performed. Results: Among the 999 participants included in the study, 748 (69.3%) were females and 251 (25.1%) were males. The mean age was 70.80 years (95% CI: 70.13, 71.47). The prevalence of malnutrition, risk of malnutrition and well-nutrition was 12.5%, 52.4% and 35.1% respectively. In the multivariate model, hypertension (adjusted OR = 1.71; 95% CI: 1.02, 2.89), alcohol consumption (aOR = 4.06; 95% CI: 1.17, 14.07), and increased age (aOR = 1.06; 95% CI: 1.01, 1.11) were positively associated with malnutrition. An increased number of people living with the older person (aOR: 0.91; 95% CI: 0.85, 0.97) was a protective factor among those at risk for malnutrition. Conclusion: Both the prevalence of malnutrition and risk of malnutrition were commonly observed among community-dwelling older persons in Sri Lanka. The associated factors identified in this study might help public health professionals to implement necessary interventions that improve the nutritional status of this population
In-service Training for Chemistry Teachers’ Proficiency: The Intermediary Effect of Collaboration Based on Teaching Experience
No full textThis research determined the effect of in-service training, collaboration and teacher proficiency on chemistry subject based on teaching experience. A total of 184 teachers were involved in this study, only 64 of which had less than 10 years of teaching experience. The data were collected via questionnaires and analysed using the software SPSS AMOS 23. The MANOVA test indicated significant differences between in-service training and collaboration based on teachers' teaching experience and parallel results between teacher proficiency in chemistry and teaching experience. The SEM test showed that collaboration has a different intermediary effect on the relationship between in-service training and teacher proficiency. Therefore, chemistry teachers with less teaching experience required additional in-service training and collaboration to enhance their proficiency, whereas experienced chemistry teachers only required in-service training. Results of this study implied that schools should organize collaborative activities that involve teachers with various experiences. Teamwork and collaboration are expected to enhance teacher proficiency in the subject
Maintenance of high-rise residential buildings
No full textPurpose: Preventive maintenance is an effective maintenance strategy to ensure the constant and efficient usage of building systems and their components. The reactive-based maintenance as the main strategy in high-rise residential buildings is a concern as the maintenance output resulting from the strategy could not achieve the standard level of performance. The purpose of this paper is to identify the characteristics of preventive maintenance and establish the relationship with maintenance performance in high-rise residential buildings. Design/methodology/approach: The characteristics of preventive maintenance and maintenance performance parameters were identified through the literature review. A quantitative approach was adopted, where a questionnaire was distributed to the maintenance personnel of high-rise residential buildings. Then, ranking analysis and correlation were conducted to produce findings that help to achieve the research objectives. Findings: The research findings indicate that there are seven maintenance characteristics significantly correlated with maintenance performance indicators (maintenance costs deviation, time variance of maintenance work, customer service and downtime rate). It is recommended that these characteristics are considered during the execution of preventive maintenance as they have a significant effect on the maintenance performance. Originality/value: The extensive literature suggests the relationship between the characteristics of preventive maintenance and maintenance performance, but is still questionable. Thus, this research investigates the relationship between preventive maintenance characteristic and maintenance performance for high-rise residential buildings in Malaysia. The findings of the research can act as a guide for maintenance personnel to optimise maintenance performance by focusing on the highlighted preventive maintenance characteristics
The nature of well-being objective function in tax-free regime of ethico-economics
No full textPurpose: The purpose of this study is to explain the effect of a tax-free regime of socioeconomics in the social well-being function. This paper carries on the message that has been recognized in the economic theory and by many for a long time now. This is that the incidence of all forms of taxes – direct and indirect taxes – proves to cause inequitable distribution of wealth. The rich still comprises the top 1 per cent of the income earners despite the existence of heavy tax burden. This paper goes beyond this observation and its explanation to make the case that the tax regime also causes distortionary effects in the generalized system of social and economic relations. Design/methodology/approach: In the midst of the generalized system of simulating the well-being function, subject to what is called the circular causation system of the endogenous variables is explained by the critical parameter of the epistemic nature in the unity of knowledge by complementarities between the variables signifying the good choices. Findings: This paper also contrarily establishes and explains the nature of equitable production and distribution of income in society at large. The tax-free regime is explained to generate and sustain balanced inter-causality between the critical variables in the generalized system of equations for simulating the well-being function. Some of the special properties of the evolutionary learning kind of the well-being simulation problem in the tax-free regime are brought out. Research limitations/implications: Empirical work could follow. Practical implications: Of special interest are the Arab Middle Eastern countries, most of which do not levy tax on households; with a small rate on businesses. Social implications: This paper goes beyond this observation and its explanation to make the case that the tax regime also causes distortionary effects in the generalized system of social and economic relations. Most importantly, the presence of tax regime disturbs the balanced forms of inter-causality between the critical variables of the social and economic type. The social well-being is thus eroded in the midst of a tax regime. Originality/value: This paper is a rare one of its kind to bring out the question surrounding the tax-free regimes usually practiced in Islamic fiscal theory and today adopted by many Muslim countries in the Middle East
Reactivity of Anodically Generated 4-Methoxystilbene Cation Radicals: The Influence of Ortho-Substituted Hydroxymethyl, Aminomethyl, and Carboxylic Acid Groups
No full textThe effect of ortho′-substituted side chains bearing nucleophilic groups such as CH 2 OH, CH 2 NHR, and CO 2 H on the reactivity of anodically generated 4-methoxy- and 3,4-dimethoxystilbene cation radicals was investigated, and results were compared with those of substrates where the nucleophilic groups such as OH and NHR are directly attached to the aromatic ring. It was found that when ortho′-substituted groups such as CH 2 OH or CH 2 NHR are present in the other ring, only direct intramolecular cation-nucleophile reactions occur to give bisbenzopyrans or bisisoquinolines. Crossover products (previously obtained when the ortho′ substituents were OH and NH 2 ) such as the fused benzoxepanes/fused benzoazepanes were not formed. When the ortho′ substituent is COOH, direct intramolecular cation-nucleophile reaction occurs to give the corresponding bis-δ-lactones in high yield. The presence of an additional 3-methoxy substituent resulted in the formation of other fused polycyclic products due to competing aromatic substitution reactions. Reaction pathways leading to the different products and reasons for the difference in behavior shown by the present stilbenes are presented. The results have provided additional insight into the reactivity and behavior of anodically generated stilbene cation radicals
Fostering political participation among students of Pesantren through new media in Madura
No full textThere are 911 of Islamic boarding schools in Madura. However, the students do not have easy access to the media via the Internet as expected. This is particularly due to some restrictions imposed by the schools on them in accessing the Internet. This resulted in the study of communication action between students of Islamic boarding schools and the new internet media; that is, how the schools and students can absorb the use of new media among students and how they play roles in political participation through new internet media. The present study employs a qualitative approach using ethnographic observations. The study uses Rogers' (1986) theory on the diffusion of innovation organizations and individuals, Roth's (1980) theory on political participation, and Wilson's (1980) theory on the pyramid of political participation. Based on diffusion of organizational innovation, it was found that the Banyuanyar Islamic boarding schools accept the existence of the Internet, but they experience lack of computer equipment (hardware), application program (software), as well as lack of experts and skills to use the facilities. As for the communication action, the use of the Internet gains wide acceptance. Most of the students even have basic knowledge to use the Internet before they enter school. The existence of media facilities may lead to the breach of rules by the students with regard to the policies of pesantren. Some efforts are needed to identify ethical violations in communication actions undertaken by the students in the use of the Internet. On the one hand, the identification of the Internet provides freedom space, but on the other, the pesantren does not have virtual security officers to deal with digital violations that may be committed by the students. The early identification of an effort is necessary to anticipate the adoption of innovations and to make boarding school students media-intelligent. In term of the tendency of political participation, the students of pesantren Banyuanyar are participative in political activities. The policy made by the pesantren leaders plays a pivotal role in political participation. The education on political participation among students of pesantren through new media is reflected in the flow of information that is accessible everywhere, particularly electronic media, which has contributed significantly to developing the mindset of the people, especially among the students of pesantren
Nonclonal Chromosomal Aberrations in Childhood Leukemia Survivors
No full textBackground: Survivors of childhood cancer are at risk of developing a second malignancy. One possible mechanism for neoplastic transformation of cells is through induction of persistent genomic instability. This study aims to seek evidence of chromosomal instability in long-term childhood leukemia survivors (CLS) in one of the largest pediatric academic oncology centers in South East Asia. Methods: 50 asymptomatic (subjects have remained leukemia-free since treatment cessation) CLS and 50 healthy controls were recruited in this cross-sectional study. Of 50 CLS, 44 had acute lymphoblastic leukemia and 6 had acute myeloid leukemia. G-banded karyotyping was performed on unstimulated peripheral blood leukocytes of all subjects. Results: CLS had significantly higher occurrence of karyotypic abnormalities compared to controls. Five CLS harbored six nonclonal abnormalities (mostly aneuploidy) while none were found in controls. Conclusion: Subpopulations with nonclonal chromosomal aberrations were present in peripheral blood leukocytes of our cohort of childhood leukemia long-term survivors