103790 research outputs found
Sort by
Activating science teachers' knowledge and lifelong journey on their pprofessional development
Full text linkHuman resource development is the backbone to a nation economic devel6pment. In fact the two are so intricately intertwined that it is safe to say that the higher the nation's level of technical know-hows and supremacy, everything else the same, the higher is its state of economic development and vice versa. The starting point of a nation's technical and scientific advancement is traceable to appropriate science teacher training programmes ofthe nation. In the case of Malaysia, although several changes have been made in the past to suit and reflect the needs of the country's technical manpower requirements, it is regrettable to note that thus far the desirable results have not been promising. It is contended that the major shortcoming lies in the less than effective professional development of science teachers inservice program practiced in the counqy. Lack of innovativeness· of the programme and lack of aoility toteach with passion amongst science teachers probably are major reasons for this. Against this background and -in an effort to activate the science teachers' knowledge and lifelong journey of continuous, school-based professional development, the SMIT TeReC portal was embarked allowing the science teachers the opportunities for networking and the sharing of on-line materials
Forensic differentiation of Malaysia biodiesel and illicit fuels using GC-FID and GC–MS techniques
Full text linkIllegal, unreported, and unregulated (IUU) fishing poses a serious threat to marine biodiversity and economic stability, particularly in coastal nations like Malaysia, where the smuggling of government-subsidized fuel is often linked to IUU activities. This study presents a forensic approach using gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC–MS) to chemically characterize and differentiate between legally distributed Malaysia biodiesel blends (B7 and B10) and illicit fuels seized from vessels involved in maritime violations. A total of 29 fuel samples from detained vessels in Kuala Terengganu and Mersing were compared with 20 reference biodiesel samples from major Malaysia fuel brands. GC-FID revealed hydrocarbon ranges of C10–C29 in biodiesel, with additional FAME peaks near n-C19 and n-C21, while IUU fuels showed wider ranges (C10–C33) but no FAMEs. GC–MS confirmed key biomarkers—bicyclic sesquiterpanes, adamantanes, isoprenoids, PAHs, and FAMEs—highlighting methyl palmitate (C16:0) and methyl oleate (C18:1) as diagnostic of biodiesel. Multivariate analyses (HCA and PCA) further separated B7, B10 and IUU samples, with subtle differences between B7 and B10 attributed to feedstock or blending variation. This study is the first to combine GC-FID, GC–MS, and chemometric analyses (PCA and HCA) into a forensic framework for differentiating Malaysian biodiesel blends (B7, B10) from illicit maritime fuels. By leveraging diagnostic biomarkers beyond FAMEs, the approach enables robust classification and provenance analysis. This integrated strategy provides evidential value for maritime law enforcement, advancing fuel forensics in Southeast Asia. These findings display the utility of chromatographic techniques in maritime law enforcement, enabling fuel source attribution and supporting legal proceedings. Despite promising results, limitations such as restricted sample coverage, lack of replicate analysis, and absence of a chromatographic fingerprint database highlight the need for further validation. The study advocates for the development of an integrated GC-based forensic framework to enhance Malaysia's capability in combatting fuel smuggling and IUU fishing activities
From attachment and support to college students' well-being: a systematic review through the lens of self-determination theory
Full text linkThis systematic review synthesized empirical evidence on the relationships among adult attachment, social support, self-determination and subjective well-being among college students. Following PRISMA guidelines, we systematically searched the Web of Science, Scopus, PsycINFO, and Google Scholar databases (2004-2024), yielding 22 eligible studies (20 cross-sectional, 2 longitudinal). The results indicated that both adult attachment and social support influenced subjective well-being through the satisfaction of basic psychological needs. Secure attachment and high levels of social support were positively associated with subjective well-being, whereas anxious and avoidant attachment styles were negatively associated. The satisfaction of basic psychological needs (autonomy, competence, and relatedness) emerged as a crucial mediating mechanism, with consistent patterns across different cultural contexts, although the sources and effects of social support varied culturally. Despite methodological limitations, including predominantly cross-sectional designs and restricted sample representativeness, this review provides valuable insights for enhancing college students' well-being through improving attachment relationships, strengthening social support networks, and facilitating basic psychological needs satisfaction. Future research should employ more longitudinal designs, expand sample diversity, and examine cultural moderators
The effect of temperature and storage time off semen samples on the spermatozoa deoxyribonucleic acid (DNA) fragmentation
Full text linkDNA fragmentation analysis is essential for evaluating sperm DNA integrity, which affects fertilization, embryo development, and pregnancy outcomes. However, many Indonesian laboratories lack access to this testing due to limited availability of commercial kits. This study aimed to assess the effects of storage temperature and duration on sperm DNA fragmentation by comparing fresh semen samples with those stored under various conditions. This post-test-only experimental study was conducted at the Biomedical Laboratory, Faculty of Medicine, Universitas Airlangga, Surabaya, from March to October 2023. Semen samples were collected from ten normozoospermic men aged 20-35 years. The samples were divided into four groups: fresh samples (P1), samples stored in a cool box (7-8 °C) for 3 hours (P2), and samples stored in a freezer at-16 °C for 3 days (P3) and 7 days (P4). DNA fragmentation was assessed using the Sperm Chromatin Dispersion (SCD) method. The Shapiro-Wilk test was used for normality. Depending on data distribution, paired t-tests or Wilcoxon signed-rank tests were applied. No significant differences were found in DNA fragmentation index between fresh and stored samples: P1 vs. P2 (p = 0.257), P1 vs. P3 (p = 0.705), and P1 vs. P4 (p = 0.102), indicating DNA stability. Sperm DNA fragmentation remains stable under the tested storage conditions. Semen samples can be stored at 7-8 °C for 3 hours or frozen at-16 °C for up to 7 days without compromising DNA integrity
Au@MOF-199 functionalized graphene oxide nanocomposite for simultaneous electrochemical detection of dopamine and uric acid
No full textSimultaneous detection of dopamine (DA) and uric acid (UA) in biological fluids is critical for diagnosing neurological and metabolic disorders. However, traditional enzymatic sensors are plagued by enzyme denaturation, limited shelf life, and poor batch-to-batch reproducibility. To address these limitations, a nonenzymatic electrochemical sensor based on a graphene oxide-gold nanoparticle-MOF-199 (GO-Au@MOF-199) nanocomposite was developed to simultaneously detect DA and UA. The ternary hybrid material was synthesized via a solvothermal method, leveraging the high surface area of MOF-199, the excellent catalytic activity of Au nanoparticles, and the superior electron transport properties of GO. The designed GO-Au@MOF-199 composites possess a large surface area (205 m2 g−1), exhibiting excellent electroanalytical capability for the detection of DA and UA. This innovative sensor, constructed on screen-printed electrodes (SPEs), exhibited distinct cathodic peak separation for DA and UA, enabling selective and sensitive dual-analyte detection. The sensor exhibited a wide linear detection range (0.1–100 μM) along with low limits of detection (LODs) of 16 nM for DA and 25 nM for UA, as well as high sensitivities of 2001 μA mM−1 cm−2 (for DA) and 1281 μA mM−1 cm−2 (for UA). Moreover, the sensor exhibited excellent operational stability (<7 % signal loss after 1000 cycles) and high recovery rates (95.7–112.9 %) in spiked urine samples, confirming its robustness and applicability for real biological samples. This work presents a robust and efficient sensing platform, showcasing the synergistic integration of nanomaterials for real-time analysis, with strong potential for point-of-care diagnostics and clinical monitoring of metabolic biomarkers
Enhancing aviation sustainability: bimetallic Ni–Co catalysts for bio-jet fuel from palm kernel oil
No full textThe production of bio-jet fuel from renewable sources such as palm kernel oil (PKO) biomass has been extensively been studied for the production of transportation fuel due to its availability. Hence, this study was focused on the production of bio-jet fuel (BJF; C8-C16) derived from PKO via catalytic deoxygenation (DO) reaction under H2-free environment over Nix-Cox supported on magnetite (Fe3O4) catalyst. The Ni and Co concentrations have been kept within 0.5–0.75 wt% to optimize the synergistic interaction between the metals and the support. The result indicated that Ni0.5-Co0.5/Fe3O4 catalyst exhibited high surface area (156.75 m2g−1) with weak (437.1 μmol/g) + strong (14601.0 μmol/g) acidic sites. In a preliminary PKO catalytic DO study conducted at 350℃ for 3 h using a 5 wt% catalyst loading under an inert N2 atmosphere, the results revealed that the Ni0.5-Co0.5/Fe3O4 catalyst exhibited higher DO activity, achieving approximately 91 % hydrocarbon selectivity. The majority of the product was in the BJF (C8-C16) fraction, accounting for 95 %. The data also showed that the Ni0.5-Co0.5/Fe3O4 catalyst was more selective towards BJF, with a selectivity value of 77 %, the highest observed for the C11 carbon chain. Based on the kinetic and deactivation study of the Ni0.5-Co0.5/Fe3O4 catalyst over a 500mins DO reaction, the results revealed that the primary cause of catalyst deactivation was coking activity. It also appeared that a higher DO temperature (350℃) positively affected coking activity. Interestingly, a longer reaction time at a lower DO temperature mitigated coking activity, with coke deposition reaching approximately 5 wt%. The Ni0.5-Co0.5/Fe3O4 catalyst demonstrates significant commercial viability for industrial bio-jet fuel production owing to its exceptional deoxygenation efficacy and adequate coking resistance
Environmentally sustainable production of biodiesel from low-cost lipid feedstock using a zirconium-based metal-organic framework sulfonated solid catalyst
Full text linkHeterogeneous acidic Zr-MOF (metal-organic framework) catalyst, UiO-66/SO3H was synthesized for palm fatty acid distillate (PFAD)-methanol esterification. The characterizations for catalyst precursor and active catalyst were carried out using infrared spectroscopy, ammonia-temperature desorption analysis, thermogravimetric analyser, X-ray diffraction, surface textural analyser, and field emission scanning microscopy. The surface area of UiO-66 and UiO-66/SO3H was 714.77 m2/g and 503.02 m2/g, respectively. Meanwhile, the acidity strength shown an increase in values, rising from 3.14 mmol/g to 7.98 mmol/g. Throughout the catalytic screening test under fixed parameters, UiO-66/SO3H produced 72.3% of fatty acid methyl ester (FAME) while 45.9% catalyzed by UiO-66. Then, UiO-66/SO3H was selected for response surface methodology-central composite design (RSM-CCD) optimization. Following 31 experiments, the optimized conditions were determined to be 75 °C, 1.3 h, 4.2 wt% catalyst, and a methanol to PFAD molar ratio of 21:1, resulting in a yield of 98.6% FAME. Reusability tests demonstrated that the catalyst maintained its activity for seven cycles, averaging 72.4% yield but subsequently dropping to 53.8% after the eighth cycle. Environmental sustainability was evaluated using life-cycle assessment (LCA) across seven impact categories: global warming potential, stratospheric ozone depletion, acidification potential, terrestrial ecotoxicity, freshwater ecotoxicity, marine ecotoxicity, and fossil resource scarcity. LCA analysis revealed that the PFAD process had a substantial global warming impact, with the exception of microalgae-based biodiesel. The PFAD process has lower acidification potential than soybean or lignocellulosic biomass. Our advanced biodiesel production method, with minimal methanol and low electricity, is an environmentally friendly alternative
Influence of residual palm oil in pressed mesocarp fiber on extracellular enzyme secretion and morphological characteristics of fungal biomass during solid-state fermentation
No full textOil palm mesocarp fiber, a lignocellulosic by-product of the crude palm oil extraction process, contains residual oil within its fibrous matrix. While mesocarp fiber from oil-bearing fruits has gained attention as a carbon source in solid-state fermentation, the role of residual oil in microbial adaptation and enzyme secretion remains unclear. This study examines the effect of residual oil on enzyme production by comparing oily mesocarp fiber (OMF) and deoiled mesocarp fiber (DeMF) as solid matrices for solid-state fermentation using Trichoderma reesei RUT-C30. Lipase and (hemi)cellulolytic enzyme activities were assessed under varying moisture content and pH conditions alongside fungal biomass morphology. OMF promoted higher lipase production, reaching 24.79 IU per gram dry solid (GDS) at a 1:3.5 solid-to-liquid ratio (SLR). In comparison, DeMF enhanced (hemi)cellulolytic enzyme activity, with CMCase peaking at a 1:1.5 SLR, while xylanase and β-glucosidase activity peaking at pH 7.5 under buffered conditions. Furthermore, residual oil exhibited an antifungal effect at pH 7.5, reducing fungal biomass and extracellular enzyme yields. These findings provide valuable insights into the role of residual oil in solid-state fermentation, highlighting its dual function as a lipase inducer and a potential inhibitor under certain conditions
A novel two-derivative multistep collocation method with fitting-techniques with application to Duffing problem
Full text linkThe general k-step fifth-order two-derivative linear multistep collocation method (TDLMM5) using collocation technique with Gegenbauer polynomial as basis function is derived for direct integrating second-order ordinary differential equation in the form u″(t)=f(t,u(t)) with periodic solution. Fifth-order two-derivative linear multistep method with various collocation points and off-set points is developed using collocation and interpolation approach. Order, stability, consistency and convergence of TDLMM5 are analyzed and discussed. Then, trigonometrically-fitting technique is adapted into TDLMM5 by setting u(t) as the linear combination of the functions {sin(λt),cos(λt)},λ∈R and turn the coefficients of TDLMM5 into frequency-dependent. Numerical experiment is conducted to verify the proposed method is superior compared to other existing methods in the literature with similar order. Additionally, the trigonometrically-fitted TDLMM5, denoted as TFTDLMM5, is applied to the well-known damped and driven oscillator problem, known as the Duffing problem. The outcome demonstrates that the proposed method is still successful in modeling this real-world application problem
Research on strain-responsive Arsenene/SnSeS heterojunction for digital media technology: a first-principles calculations
No full textThe rapid advancement of artificial intelligence and big data has led to a significant increase in global demand for data storage and information transmission, raising concerns regarding capacity and efficiency. Consequently, the development of novel stimulus-responsive materials has emerged as a critical area of research. This study presents the construction of a new Arsenene/SnSeS heterojunction and employs first-principles methods to manipulate its electronic and optical properties through the application of strain. The computational findings reveal that the Arsenene/SnSeS heterojunction demonstrates remarkable stability and favorable electronic characteristics. Notably, the bandgap of the heterojunction is smaller than that of both the Arsenene monolayer and the SnSeS monolayer, thereby facilitating enhanced charge transfer. Furthermore, the electronic properties of the Arsenene/SnSeS heterojunction can be effectively modulated by strain, which induces redshift or blueshift in the optical absorption peaks. These research outcomes offer valuable insights for the advancement of intelligent stimulus-responsive materials