Displaying publications 1 - 20 of 120 in total

  1. Rosedale JL
    Matched MeSH terms: Sunlight
  2. Ng, K.M., Adam, N.M., Azmi, B.Z.
    A numerical simulation of UPM Solar Bowl is presented in this paper. The numerical analysis considereda general model of solar bowl, which was divided into three modules: (a) reflection characterisation ofthe bowl, (b) solar flux density along the receiver, and (c) radiation contour mapping of the receiver.The governing equations are resolved in a segregated manner using Matlab programming environment.The influence of the tropical clear sky irradiance on the collector was numerically studied, whereas thecollector performance in time domain was also quantified. Single reflection is a major element in thermalconcentration. It was observed that solar flux density of collector substantially deteriorated during offsolar noon hour, in which during 08:00 and 16:00 under clear sky of tropics, the percentage reductionof flux density is over 82% at all points of the receiver. The simulated radiation contour mapping of thereceiver supports the finding. Other results of the UPM Solar Bowl simulation model are also shownand discussed.
    Matched MeSH terms: Sunlight
  3. Prabhu N, Saravanan D, Kumarasamy S
    Environ Sci Pollut Res Int, 2023 Sep;30(42):95086-95105.
    PMID: 37582893 DOI: 10.1007/s11356-023-28807-z
    Solar energy provides desired thermal energy for diverse applications, including industrial heating, domestic cooking, power generation, desalination, and agri-food preservation. Despite extensive research on solar drying from the scientific community, there are limited practical applications for small-scale use. This review attempts to analyze the design features of three specific types of dryers for food drying applications: solar evacuated tube dryers, biomass dryers, and hybrid solar dryers. The thermal performance of the three dryers is evaluated in terms of drying time, moisture removal, and temperature attained during drying. The review also assesses the prospects of solar dryers, highlighting the need for further research into innovative designs and advanced drying capabilities. The study provides valuable information for enhancing dryer performance with various integrated solutions.
    Matched MeSH terms: Sunlight*
  4. Chong KK, Wong CW, Siaw FL, Yew TK, Ng SS, Liang MS, et al.
    Sensors (Basel), 2009;9(10):7849-65.
    PMID: 22408483 DOI: 10.3390/s91007849
    A novel on-axis general sun-tracking formula has been integrated in the algorithm of an open-loop sun-tracking system in order to track the sun accurately and cost effectively. Sun-tracking errors due to installation defects of the 25 m(2) prototype solar concentrator have been analyzed from recorded solar images with the use of a CCD camera. With the recorded data, misaligned angles from ideal azimuth-elevation axes have been determined and corrected by a straightforward changing of the parameters' values in the general formula of the tracking algorithm to improve the tracking accuracy to 2.99 mrad, which falls below the encoder resolution limit of 4.13 mrad.
    Matched MeSH terms: Sunlight
  5. Samedani B, Juraimi AS, Anwar MP, Rafii MY, Sheikh Awadz SH, Anuar AR
    ScientificWorldJournal, 2013;2013:308646.
    PMID: 24163618 DOI: 10.1155/2013/308646
    Axonopus compressus is one of the native soft grass species in oil palm in Malaysia which can be used as a cover crop. The competitive ability of A. compressus to overcome A. gangetica was studied using multiple-density, multiple-proportion replacements series under a glasshouse and full sunlight conditions in a poly bag for 10 weeks. A. compressus produced more dry weight and leaf area when competing against A. gangetica than in monoculture at both densities in the full sunlight and at high density in the shade. Moreover, the relative yield and relative crowding coefficients also indicated A. compressus is a stronger competitor than A. gangetica at both densities in the full sunlight and high density in the shade. It seemed that A. gangetica plants in the shade did not compete with each other and were more competitive against A. compressus as could influence A. compressus height in the shade. It is concluded that although suppression of A. gangetica by A. compressus occurred under full sunlight, irrespective of plant density, this ability reduced under shade as A. compressus density decreased. The result suggests that A. compressus in high density could be considered as a candidate for cover crops under oil palm canopy.
    Matched MeSH terms: Sunlight*
  6. Klomp DA, Stuart-Fox D, Das I, Ord TJ
    Biol Lett, 2017 Feb;13(2).
    PMID: 28179410 DOI: 10.1098/rsbl.2016.0979
    Effective communication requires animal signals to be readily detected by receivers in the environments in which they are typically given. Certain light conditions enhance the visibility of colour signals and these conditions can vary depending on the orientation of the sun and the position of the signaller. We tested whether Draco sumatranus gliding lizards modified their position relative to the sun to enhance the conspicuousness of their throat-fan (dewlap) during social display to conspecifics. The dewlap was translucent, and we found that lizards were significantly more likely to orient themselves perpendicular to the sun when displaying. This increases the dewlap's radiance, and likely, its conspicuousness, by increasing the amount of light transmitted through the ornament. This is a rare example of a behavioural adaptation for enhancing the visibility of an ornament to distant receivers.
    Matched MeSH terms: Sunlight*
  7. Chan XY, Arumugam R, Choo SW, Yin WF, Chan KG
    Genome Announc, 2013;1(4).
    PMID: 23950114 DOI: 10.1128/genomeA.00540-13
    Tropical seawater harbors a rich diversity of microorganisms as a result of its nutrient-rich environment, constant supply of sufficient sunlight, and warm climate. In this report, we present the complexity of the microbial diversity of the surface seawater of the Georgetown coast as determined using next-generation sequencing technology.
    Matched MeSH terms: Sunlight
  8. Pazikadin AR, Rifai D, Ali K, Mamat NH, Khamsah N
    Sensors (Basel), 2020 Nov 25;20(23).
    PMID: 33255797 DOI: 10.3390/s20236744
    Photovoltaic (PV) systems need measurements of incident solar irradiance and PV surface temperature for performance analysis and monitoring purposes. Ground-based network sensor measurement is preferred in many near real-time operations such as forecasting and photovoltaic (PV) performance evaluation on the ground. Hence, this study proposed a Fuzzy compensation scheme for temperature and solar irradiance wireless sensor network (WSN) measurement on stand-alone solar photovoltaic (PV) system to improve the sensor measurement. The WSN installation through an Internet of Things (IoT) platform for solar irradiance and PV surface temperature measurement was fabricated. The simulation for the solar irradiance Fuzzy Logic compensation (SIFLC) scheme and Temperature Fuzzy Logic compensation (TFLC) scheme was conducted using Matlab/Simulink. The simulation result identified that the scheme was used to compensate for the error temperature and solar irradiance sensor measurements over a variation temperature and solar irradiance range from 20 to 60 °C and from zero up to 2000 W/m2. The experimental results show that the Fuzzy Logic compensation scheme can reduce the sensor measurement error up to 17% and 20% for solar irradiance and PV temperature measurement.
    Matched MeSH terms: Sunlight
  9. Maazullah Khan, Abdurab, Muhammad Hanif, Mansoor Khan Khattak, Muhammad Ramzan
    Sains Malaysiana, 2018;47:1061-1067.
    Air heating by solar collectors is renewable technology providing hot air for different purposes. The present research
    emphasizes on analysis of energy, exergy and efficiency of a flat plate solar air heater. The analysis model was tested
    on five different air mass flow rates of 0.5 (Natural), 1.31, 2.11, 2.72 and 3.03 kgs-1 under three different tilt angles of
    25, 35 (Recommended) and 50o
    . The data was replicated three times making a total of 45 treatments. A two factorial
    completely randomized design was used to find if there is any significant difference among the treatments. The results
    showed that the solar collector gave better performance at air mass flow of 3.03 kgs-1 under tilt of 35o
    . At maximum
    air mass flow rate of 3.03 kgs-1and optimum tilt angle of 35o
    the maximum energetic efficiency of 51%, while minimum
    exergetic efficiency of 24% and maximum overall efficiency of 71% were recorded. It was concluded that to get maximum
    thermal efficiencies of 71% from flat plate solar collector used as an air heater must be operated at high air mass flow
    rates of 3.03 kgs-1under 35o
    tilt angle at Peshawar, Pakistan.
    Matched MeSH terms: Sunlight
  10. Jaaz AH, Hasan HA, Sopian K, Kadhum AAH, Gaaz TS, Al-Amiery AA
    Materials (Basel), 2017 Aug 01;10(8).
    PMID: 28763048 DOI: 10.3390/ma10080888
    This paper discusses the effect of jet impingement of water on a photovoltaic thermal (PVT) collector and compound parabolic concentrators (CPC) on electrical efficiency, thermal efficiency and power production of a PVT system. A prototype of a PVT solar water collector installed with a jet impingement and CPC has been designed, fabricated and experimentally investigated. The efficiency of the system can be improved by using jet impingement of water to decrease the temperature of the solar cells. The electrical efficiency and power output are directly correlated with the mass flow rate. The results show that electrical efficiency was improved by 7% when using CPC and jet impingement cooling in a PVT solar collector at 1:00 p.m. (solar irradiance of 1050 W/m² and an ambient temperature of 33.5 °C). It can also be seen that the power output improved by 36% when using jet impingement cooling with CPC, and 20% without CPC in the photovoltaic (PV) module at 1:30 p.m. The short-circuit current ISC of the PV module experienced an improvement of ~28% when using jet impingement cooling with CPC, and 11.7% without CPC. The output of the PV module was enhanced by 31% when using jet impingement cooling with CPC, and 16% without CPC.
    Matched MeSH terms: Sunlight
  11. Chew YH, Tang JY, Tan LJ, Choi BWJ, Tan LL, Chai SP
    Chem Commun (Camb), 2019 May 28;55(44):6265-6268.
    PMID: 31086906 DOI: 10.1039/c9cc01449g
    The engineering of surface oxygen vacancies (OVs) in WO3 was primitively done using a facile solvothermal method. The photocatalytic activities of the as-prepared samples were studied by evaluating their performances in the photocatalytic OER. The best sample (W-3) yielded 57.6 μmol of O2 in 6 h under the illumination of simulated sunlight.
    Matched MeSH terms: Sunlight
  12. Aminah H, Naimah C, Rajabarizan R, Mohd Noor M
    Sains Malaysiana, 2013;42:257-263.
    A factorial experiment of three light intensities and three fertiliser levels was carried out on the potted seedlings of neobalanocarpus heimii as stock plants for subsequent rooting of cuttings. Light intensities used were 25%, 50% and 100% of the open sunlight and the fertilizer levels were 0 g, 1 g and 2 g plant-1 month-1. Results of 11 months after potting showed that the stock plants treated with 1 g and 2 g fertilizer had significantly better height and diameter increments than those without fertilizer in all light intensities tried. On the other hand, no significant effect of light intensity was obtained in height and diameter increments of the stock plants. Survival of stock plants of more than 86% was obtained in all light intensities tried with or without fertilizer application. Test on rooting of subsequent cuttings showed that light intensity of 25% and 0 g fertiliser, to stock plants gave the highest rooting percentage (73%) and the number of roots (2.0). The general trend showed that rooting decreased to below 60% when intensity of light was increased. In terms of size, cuttings with diameter between 1.2 mm and 2.3 mm is recommended as it yielded rooting of 65% to 75%. For practical application, a combination of 25% light intensity and 1 g of fertilizer plant-1 month-1 can be applied to the stock plants to maintain their healthy growth for continuous production of cutting materials for rooting.
    Matched MeSH terms: Sunlight
  13. Sabry AH, Hasan WZW, Ab Kadir M, Radzi MAM, Shafie S
    PLoS One, 2017;12(9):e0185012.
    PMID: 28934271 DOI: 10.1371/journal.pone.0185012
    The main tool for measuring system efficiency in homes and offices is the energy monitoring of the household appliances' consumption. With the help of GUI through a PC or smart phone, there are various applications that can be developed for energy saving. This work describes the design and prototype implementation of a wireless PV-powered home energy management system under a DC-distribution environment, which allows remote monitoring of appliances' energy consumptions and power rate quality. The system can be managed by a central computer, which obtains the energy data based on XBee RF modules that access the sensor measurements of system components. The proposed integrated prototype framework is characterized by low power consumption due to the lack of components and consists of three layers: XBee-based circuit for processing and communication architecture, solar charge controller, and solar-battery-load matching layers. Six precise analogue channels for data monitoring are considered to cover the energy measurements. Voltage, current and temperature analogue signals were accessed directly from the remote XBee node to be sent in real time with a sampling frequency of 11-123 Hz to capture the possible surge power. The performance shows that the developed prototype proves the DC voltage matching concept and is able to provide accurate and precise results.
    Matched MeSH terms: Sunlight
  14. Khalik WF, Ho LN, Ong SA, Voon CH, Wong YS, Yusoff N, et al.
    Chemosphere, 2017 Oct;184:112-119.
    PMID: 28586651 DOI: 10.1016/j.chemosphere.2017.05.160
    The photocatalytic fuel cell (PFC) system was developed in order to study the effect of several operating parameters in degradation of Reactive Black 5 (RB5) and its electricity generation. Light irradiation, initial dye concentration, aeration, pH and cathode electrode are the operating parameters that might give contribution in the efficiency of PFC system. The degradation of RB5 depends on the presence of light irradiation and solar light gives better performance to degrade the azo dye. The azo dye with low initial concentration decolorizes faster compared to higher initial concentration and presence of aeration in PFC system would enhance its performance. Reactive Black 5 rapidly decreased at higher pH due to the higher amount of OH generated at higher pH and Pt-loaded carbon (Pt/C) was more suitable to be used as cathode in PFC system compared to Cu foil and Fe foil. The rapid decolorization of RB5 would increase their voltage output and in addition, it would also increase their Voc, Jsc and Pmax. The breakage of azo bond and aromatic rings was confirmed through UV-Vis spectrum and COD analysis.
    Matched MeSH terms: Sunlight
  15. Udaya Kumar V, Pavan G, Murti K, Kumar R, Dhingra S, Haque M, et al.
    Clin Nutr ESPEN, 2021 Dec;46:21-32.
    PMID: 34857198 DOI: 10.1016/j.clnesp.2021.09.727
    The catastrophic pandemic engendered due to the Novel coronavirus (COVID-19) outbreak which causes severe clinical afflictions on the respiratory system has severely high morbidity and mortality rates. The requirement of novel compounds is at utmost importance due to lack of targeted drug molecule to treat the afflictions and restrict the viral infection and for the usage of prophylactic treatment to avoid the spread of the infection is of utmost importance. Vitamin D is one such naturally available multifunctional molecule, which plays an eminent role in the immune system and instigation of numerous cellular pathways further promoting health benefits and enhancing the human quality of life. This article reviews the current standpoint scenario and future prevalence of vitamin D supplementation in the management of covid-19 patients. Novel findings of Vitamin D suggest that along with regulation of cell growth, neuroprotective and mood-stabilizing effects, it regulates the immune response also modulate cytokine Interleukin-6 (IL-6) by inducing progesterone-induced blocking factor (PIBF), given the IL-6 levels are considerably high in COVID-19 patients which increases the further complications. Vitamin D also have its effect on angiotensin converting enzyme (ACEII) inhibitor through which the COVID-19 virus makes cell entry. Numerous research data elucidate the play of Vitamin D, in complications of COVID-19 including the most common comorbid conditions, neurological manifestations and immunological aspects makes it an ideal molecule for adjuvant therapy. Including Vitamin D as add-on therapy in the management of COVID-19 might aid the arrest of infection and helps fight this arduous epidemic.
    Matched MeSH terms: Sunlight
  16. Bauer M, Glenn T, Achtyes ED, Alda M, Agaoglu E, Altınbaş K, et al.
    J Psychosom Res, 2022 Sep;160:110982.
    PMID: 35932492 DOI: 10.1016/j.jpsychores.2022.110982
    OBJECTIVE: Circadian rhythm disruption is commonly observed in bipolar disorder (BD). Daylight is the most powerful signal to entrain the human circadian clock system. This exploratory study investigated if solar insolation at the onset location was associated with the polarity of the first episode of BD I. Solar insolation is the amount of electromagnetic energy from the Sun striking a surface area of the Earth.

    METHODS: Data from 7488 patients with BD I were collected at 75 sites in 42 countries. The first episode occurred at 591 onset locations in 67 countries at a wide range of latitudes in both hemispheres. Solar insolation values were obtained for every onset location, and the ratio of the minimum mean monthly insolation to the maximum mean monthly insolation was calculated. This ratio is largest near the equator (with little change in solar insolation over the year), and smallest near the poles (where winter insolation is very small compared to summer insolation). This ratio also applies to tropical locations which may have a cloudy wet and clear dry season, rather than winter and summer.

    RESULTS: The larger the change in solar insolation throughout the year (smaller the ratio between the minimum monthly and maximum monthly values), the greater the likelihood the first episode polarity was depression. Other associated variables were being female and increasing percentage of gross domestic product spent on country health expenditures. (All coefficients: P ≤ 0.001).

    CONCLUSION: Increased awareness and research into circadian dysfunction throughout the course of BD is warranted.

    Matched MeSH terms: Sunlight
  17. Idris A, Hassan N, Rashid R, Ngomsik AF
    J Hazard Mater, 2011 Feb 15;186(1):629-35.
    PMID: 21168966 DOI: 10.1016/j.jhazmat.2010.11.101
    Physical adsorption and photocatalytic reduction of Cr(VI) in magnetic separable beads were investigated. In order to elucidate the kinetics of photocatalytic process, operating parameters such as catalyst dosage and the initial concentration were examined in detail. It was observed that the reduction rate of Cr(VI) increased with an increase in the catalyst loading, as this translated into an increase in the number of available active sites. Critical scrutiny of the percentage of the initial reduction rate versus time at various initial concentration of Cr(VI) revealed that the rate of substrate conversion decreased as the initial concentration increased. The kinetic analysis of the photoreduction showed that the removal of Cr(VI) satisfactory obeyed the pseudo first-order kinetic according to the Langmuir-Hinshelwood (L-H) model and the absorption of Cr(VI) on the magnetic beads surfaces was the controlling step in the entire reduction process. Furthermore, desorption experiments by elution of the loaded gels with sodium hydroxide indicated that the magnetic photocatalyst beads could be reused without significant losses of their initial properties even after 3 adsorption-desorption cycles.
    Matched MeSH terms: Sunlight*
  18. Ghazvinian H, Mousavi SF, Karami H, Farzin S, Ehteram M, Hossain MS, et al.
    PLoS One, 2019;14(5):e0217634.
    PMID: 31150467 DOI: 10.1371/journal.pone.0217634
    Solar energy is a major type of renewable energy, and its estimation is important for decision-makers. This study introduces a new prediction model for solar radiation based on support vector regression (SVR) and the improved particle swarm optimization (IPSO) algorithm. The new version of algorithm attempts to enhance the global search ability for the PSO. In practice, the SVR method has a few parameters that should be determined through a trial-and-error procedure while developing the prediction model. This procedure usually leads to non-optimal choices for these parameters and, hence, poor prediction accuracy. Therefore, there is a need to integrate the SVR model with an optimization algorithm to achieve optimal choices for these parameters. Thus, the IPSO algorithm, as an optimizer is integrated with SVR to obtain optimal values for the SVR parameters. To examine the proposed model, two solar radiation stations, Adana, Antakya and Konya, in Turkey, are considered for this study. In addition, different models have been tested for this prediction, namely, the M5 tree model (M5T), genetic programming (GP), SVR integrated with four different optimization algorithms SVR-PSO, SVR-IPSO, Genetic Algorithm (SVR-GA), FireFly Algorithm (SVR-FFA) and the multivariate adaptive regression (MARS) model. The sensitivity analysis is performed to achieve the highest accuracy level of the prediction by choosing different input parameters. Several performance measuring indices have been considered to examine the efficiency of all the prediction methods. The results show that SVR-IPSO outperformed M5T and MARS.
    Matched MeSH terms: Sunlight*
  19. Khalik WF, Ho LN, Ong SA, Voon CH, Wong YS, Yusuf SY, et al.
    Chemosphere, 2018 Jul;202:467-475.
    PMID: 29579681 DOI: 10.1016/j.chemosphere.2018.03.113
    The role of azo dye Reactive Black 5 (RB5) as an electron donor and/or electron acceptor could be distinguished in dual chamber of photocatalytic fuel cell (PFC). The introduction of RB5 in anode chamber increased the voltage generation in the system since degradation of RB5 might produce electrons which also would transfer through external circuit to the cathode chamber. The removal efficiency of RB5 with open and closed circuit was 8.5% and 13.6%, respectively and removal efficiency for open circuit was low due to the fact that recombination of electron-hole pairs might happen in anode chamber since without connection to the cathode, electron cannot be transferred. The degradation of RB5 in cathode chamber with absence of oxygen showed that electrons from anode chamber was accepted by dye molecules to break its azo bond. The presence of oxygen in cathode chamber would improve the oxygen reduction rate which occurred at Platinum-loaded carbon (Pt/C) cathode electrode. The Voc, Jsc and Pmax for different condition of ultrapure water at cathode chamber also affected their fill factor. The transportation of protons to cathode chamber through Nafion membrane could decrease the pH of ultrapure water in cathode chamber and undergo hydrogen evolution reaction in the absence of oxygen which then increased degradation rate of RB5 as well as its electricity generation.
    Matched MeSH terms: Sunlight*
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links