608 research outputs found
A Comparative Modeling and Analysis of Voltage Variation by Using Spectrogram
In this paper, the power quality (PQ) disturbance which is the voltage variations consist of voltage swell, sag and interruption are model and analyze. Different types of voltage variations PQ disturbances models are developed and created by using MATLAB/Simulink as well as mathematical models. The mathematical and Simulink model are used to compare in terms of time-frequency representation (TFR). The Simulink models include shutting down enormouscapacities from system to resemble voltage swell, large loads energizing and three-phase fault to simulate voltage sag as well as implementing permanent three-phase fault to simulate voltage interruption. The signals generated are analyzed by using linear time-frequency distribution (TFD). The signal parameters such as root mean square voltage (Vrms), total harmonic distortion (THD) and power value are estimated from the TFR to identify the characteristics of the voltage variation. The results of analysis on the PQ disturbance waveforms generated are identical to the actual real-time PQ signals and the models can be modified to any desired situation respectively. The PQ waveforms obtained are suitable to be further analyzed
The impact of novel coronavirus (2019-nCoV) pandemic movement control order (MCO) on dengue cases in Peninsular Malaysia
This study has highlighted the trend of recently-reported dengue cases after the implementation of the Movement Control Orders (MCOs) caused due to COVID-19 pandemic in Malaysia. The researchers used the dengue surveillance data published by the Malaysian Ministry of Health during the 3 phases of MCO (which ranged between 17th March 2020 and 28th April 2020) was used for determining the cumulative number of dengue patients. Thereafter, the dengue cases were mapped using the Geographical Information System (GIS). The results indicated that during the 42 days of MCO in Peninsular Malaysia, 11,242 total cases of dengue were reported. The daily trend of the dengue cases showed a decrease from 7268 cases that occurred before the MCOs to 4662 dengue cases that occurred during the initial 14 days of the COVID-19 pandemic (i.e., MCO I), to 3075 cases occurring during the MCO II and 3505 dengue cases noted during MCO III. The central peninsular region showed a maximal decrease in new dengue cases (52.62%), followed by the northern peninsular region (1.89%); eastern coastal region (1.25%) and the southern peninsular region (1.14%) during the initial MCO implementation. However, an increase in the new dengue cases was noted during the MCO III period, wherein all states showed an increase in the new dengue cases as compared during MCO II. The decrease in the pattern was not solely based on the MCO, hence, further investigation is necessary after considering different influencing factors. These results have important implication for future large-scale risk assessment, planning and hazard mitigation on dengue management
Evaluation of the protective efficacy of immunoglobulin Y (IgY- antibodies) prepared against Walterinnesia aegyptia snake venom in Saudi Arabia
Four groups of eight chickens were immunized intramuscularly with Walterinnesia aegyptia snake venoms mixed with Freund's complete adjuvant during the period from 1st October 2009 to 1st October 2011 at the Center of Excellence in Biotechnology Research, King Saud University, Saudi Arabia. Three weeks later, the injections were repeated with the venoms in incomplete Freund's adjuvant. Three boosters were given with the venoms at three weeks intervals. The immunoglobulin Y (IgY)-antibodies was extracted by ammonium sulphate-caprylic acid method, the antibody titer were tested by enzyme linked immunosorbant assay and the protective efficacies of the extracted immunoglobulins were performed. IgY-preparation extracted by ammonium sulphate-caprylic acid method showed lack of low molecular weight bands (non-immunoglobulin proteins) and the bands representing IgY-antibodies, which have molecular weights ranging from 180 to 200 kDa, appeared sharp and clear. Moreover, evaluation of the protective value of the IgY - antibodies prepared revealed that, one milliliter of extracted IgY-antibodies containing 15 mg/ml anti-W. aegyptia venom specific IgY could produce 100% protection against 50 LD50 and 75% protection against 60 LD50. Laying hens could be used as an alternative source of polyclonal antibodies against W. aegyptia snake venoms due to several advantages as compared with mammals traditionally used for such purpose.Keywords: Snake venom, Walterinnesia aegyptia, immunoglobulins Y, protective efficacy, caprylic aci
Recommended from our members
Motives for Participation and Amount of Physical Activity among Kelantan Chinese Adolescents
This work was supported by the Universiti Sains Malaysia Short Term Grant (Grant Scheme No. 304/PPSP/61313082).Background: Engaging in regular physical activity (PA) has become a worldwide issue for the prevention of numerous chronic diseases; therefore, is important to increase students’ desires to engage in PA by triggering their motivation. The purpose of this study was to examine the relationships between the motives for participating in PA and the amount of PA that secondary Chinese school students in Kelantan undertake. Methods: The participants consisted of 304 Chinese secondary school students (males = 165, females = 139) with a mean age of 13.55 years old (SD = 0.57) who volunteered to complete three measures, consisting of a demographic information form, the physical activity and leisure motivation scale for youth-Chinese version (PALMS-Y-C) and the Godin leisure-time exercise questionnaire-Chinese version (GLTEQ-C). Results: There were significant positive correlations between all the seven PA participation motives with amount of exercise (Enjoyment: r = 0.16, P = 0.010; Mastery: r = 0.23, P < 0.001; Competition: r = 0.21, P = 0.001; Affiliation: r = 0.22, P < 0.001; Psychological condition: r = 0.26, P < 0.001; Appearance: r = 0.20, P = 0.001; Physical condition: r = 0.20, P = 0.001). There were also significant mean differences among sweating exercise frequency categories in all the seven areas of PA participation motives (Enjoyment: P = 0.003, Mastery: P < 0.001, Competition: P = 0.001, Affiliation: P = 0.001, Psychological condition: P = 0.038, Appearance = 0.002, Physical condition: P = 0.004). Conclusion: The present study provided insight into how to promote PA in Kelantan Chinese school-aged children by specifically targeting their motives. Interventions targeting these motives could increase the amount of PA among Kelantan Chinese youths
Bringing fuel poverty forward from post-intervention evaluations to design and decision-making stages
A framework to identify and prioritise the key sustainability indicators: Assessment of heating systems in the built environment
Sustainability indicators (SIs) are important instruments to quantify, analyse, and communicate complex sustainability information, with a history of application in energy research. It is critical to identify an effective set of indicators which can holistically evaluate the energy systems encompassing the three facets of sustainability: environment, economy, and society. However, the literature has been lacking in either proportionally representing the sustainability dimensions or reflecting the stakeholders’ preferences. This paper develops a framework to identify and prioritise a set of SIs, critically reviewed to ensure reflection of a wide array of factors and conceptions of what sustainability entails. The developed framework utilises a series of methods within three phases: identification, refinement, and prioritisation. Applying the proposed framework to building heating technologies, a set of 22 SIs consisting of 4 economic, 8 environmental, and 10 social indicators were identified. According to the results, the economic indicators of Operation & Maintenance Cost and Net Present Value were found to be the most impactful factors, while environmental SIs contribute the most to the overall sustainability weight. The identified indicators apply to the assessment of heating systems and policies, and the proposed framework could more broadly support analysis of key sustainability criteria in various fields
Modulation of Sn concentration in ZnO nanorod array: intensification on the conductivity and humidity sensing properties
Tin (Sn)-doped zinc oxide (ZnO) nanorod arrays (TZO) were synthesized onto aluminum-doped ZnO-coated glass substrate via a facile sonicated sol–gel immersion method for humidity sensor applications. These nanorod arrays were grown at different Sn concentrations ranging from 0.6 to 3 at.%. X-ray diffraction patterns showed that the deposited TZO arrays exhibited a wurtzite structure. The stress/strain condition of the ZnO film metamorphosed from tensile strain/compressive stress to compressive strain/tensile stress when the Sn concentrations increased. Results indicated that 1 at.% Sn doping of TZO, which has the lowest tensile stress of 0.14 GPa, generated the highest conductivity of 1.31 S cm− 1. In addition, 1 at.% Sn doping of TZO possessed superior sensitivity to a humidity of 3.36. These results revealed that the optimum performance of a humidity-sensing device can be obtained mainly by controlling the amount of extrinsic element in a ZnO film
Planning energy interventions in buildings and tackling fuel poverty: Can two birds be fed with one scone?
Energy retrofitting and renovations are an inseparable part of decarbonisation strategies in the building sector. These measures are often tied up with several social factors that can potentially impact the wellbeing of households and the community if the end-user requirements are not carefully considered. Fuel poverty is one of these social factors that is an essential consideration for designing effective, just, and user-centred interventions, but it is often overlooked in engineering processes. Therefore, this article seeks to re-connect the notion of fuel poverty to practice by bringing it forward from the post-intervention assessments to the design and decision-making stages. To do so, a new indicator, Potential Fuel Poverty Index (PFPI), is developed to obtain the likelihood of fuel poverty that future interventions can pose to the households. The PFPI presents a more targeted analysis of fuel poverty by reflecting the socio-spatial characterisation of the households. Using the PFPI, fuel poverty can be observed as a design/decision factor at the early stages of sketching interventions, in conjunction with other economic, environmental, and technical factors. Finally, the utility of the developed method is demonstrated using a real case study in the UK, assessing the impact of heat decarbonisation through heat pumps on fuel poverty
Effect of renal sympathetic nerve on adrenergically and angiotensin II-induced renal vasoconstriction in normal Wistar-Kyoto rats
- …