144 research outputs found

    Mycotoxins-Induced Oxidative Stress and Disease

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    Smart cards and the fingerprint: a framework for user identification and authentication

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    Access control has been a great concern in this Information and Communication Technology (ICT) era. The need to control access to certain information and resources has been taken seriously by the ICT community. This research believes that no single security method, algorithm, key or procedure is entirely secure. Hence, a combination of multiple security components is mandatory to provide a high level of protection against fraud and other threats. This research combines two security components, which are the smart card and fingerprint recognition. It looks into the vulnerabilities of magnetic-stripe cards and Personal Identification Numbers (PIN) or passwords widely used in systems today. As a result, the research proposed a framework for user identification and authentication in automatic-teller-machine (ATM) systems using fingerprints and smart cards as opposed to the PIN and magnetic-stripe cards

    Spatial variations of rain intensity over a short length propagation for 5G links based on a rain gauge network

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    Millimeter-wave (mm-wave) frequency range is among operating bands designated for terrestrial 5G networks. A critical challenge of link-budgeting in mm-wave 5G networks is the precise estimation of rain attenuation for short-path links. The difficulties are further amplified in tropical and subtropical regions where the rainfall rate has a higher intensity. Different models have been proposed to predict rain attenuation. The distance factor is an important parameter in predicting total attenuation from specific rain attenuation. This study investigates the distance factor based on rain gauge networks and measured rain attenuation at 26 GHz for a 300 m link in Malaysia. Considerable discrepancies between available models were observed especially when applied for shorter path links. Also, significant variability of rain intensity is observed from the rain gauge network. This study recommends further investigation of the distance factor for a shorter link. Hence, a measurement campaign incorporating rain gauge networks was established to examine spatial variations of rain intensity over a less than 1 km link. The motivation is to develop a suitable distance factor model for 5G mm-wave propagation

    ASSESSMENT OF SEASONAL VARIABILITY FOR WIND SPEED AND SIGNIFICANT WAVE HEIGHT USING SATELLITE ALTIMETER OVER MALAYSIAN SEAS

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    Malaysia is located in the equatorial region and experienced climate hot, humid and rainy throughout the year. These have brought four monsoon seasons to Malaysia which can be categorised as Northeast monsoon, Southwest monsoon, First-inter monsoon and Second-inter monsoon. Although Malaysia is surrounded by large scale marine resources, the lack of understanding in seasonal variability has affected the spatial and temporal analysis. Thus, this study will highlight the assessment of seasonal variability of wind speed and significant wave height over the Malaysian seas. For more than two decades satellite altimeter data were used to generate a prolonged trend of regional ocean wind speed and significant wave height in order to study the monsoons in Malaysia. A set of wind speed and significant wave height data are compared with the in-situ measurement to validate the accuracy of the wind speed and significant wave height observation using the satellite altimeter. Two selected buoys were using as benchmarks and assessed using the statistical analysis by conducting a root mean square error and a correlation calculation. Seasonal variations assessment is conducted with significance to analyse the monsoon effect towards the wind speed and significant wave height condition. As a result, both ocean parameters present a good value of root mean square error and positive correlation which were 0.7976 (wind speed) and 0.92 (significant wave height), which proves the measurement from satellite altimeter is reliable to use. In addition, the seasonal variation assessment illustrates during the Northeast monsoon, each part of the Malaysian seas experienced with great wind speed and significant wave height

    The protective effects of adenosine deaminase inhibitor and ouercetin against hepatocellular carcinoma induced by thioacetamide in male rats via downregulation of iNOS, Ki67 and Pan-CK

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    The liver is the largest and most vulnerable organ in the body, several factors can cause liver cirrhosis and the onset of hepatocellular carcinoma. This study aims to investigate the possibility for adenosine deaminase inhibitor (EHNA) which reduces liver injury, neutrophil infiltration and the levels of proinflammatory cytokines and also it is considering as a target of liver cirrhosis and beginning of hepatocellular carcinoma protective, quercetin which is one of the most common flavonoids has an antioxidant, antitumor and chemopreventive effect on the liver-induced preneoplastic lesions and their combination against thioacetamide as a hepatotoxic and a carcinogenic compound. Biochemical, histopathological and immunohistochemical studies were carried out on male albino rats model to evaluate this possibility. Thioacetamide-treated rats showed a significant increase in liver function tests, alpha-fetoprotein level, expression of inducible Nitric Oxide Synthesis (iNOS), Ki67 and Pan-Cytokeratin (Pan-CK) in hepatic tissue of rats. The results of the present study show that treatment with quercetin, EHNA or their combination attenuated changes in liver functions, histopathological changes, reduced collagen deposition and decreased the expression of iNOS, Ki67 and Pan-CK induced by thioacetamide

    TaqMan real-time PCR assay for relative quantitation of white spot syndrome virus infection in Penaeus monodon Fabricius exposed to ammonia.

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    White spot disease is caused by a highly virulent pathogen, the white spot syndrome virus (WSSV). The disease is usually triggered by changes in environmental parameters causing severe losses to the shrimp industry. This study was undertaken to quantify the relative WSSV load in shrimp exposed to ammonia, using a TaqMan-based real-time PCR, and their subsequent susceptibility to WSSV. Shrimp were exposed to different levels of total ammonia nitrogen (TAN) (8.1, 3.8 and 1.1 mg L−1) for 10 days and challenged with WSSV by feeding WSSV-positive shrimp. WSSV was detected simultaneously in haemolymph, gills and pereopods at four hours post-infection. The TaqMan real-time PCR assay showed a highly dynamic detection limit that spanned over 6 log10 concentrations of DNA and high reproducibility (standard deviation 0.33–1.42) and small correlation of variability (CV) (1.89–3.85%). Shrimp exposed to ammonia had significantly higher (P < 0.01) WSSV load compared to the positive control, which was not exposed to ammonia. Shrimp exposed to 8.1 mg L−1 of TAN had the highest (P < 0.01) WSSV load in all three organs in comparison with those exposed to 3.8 and 1.1 mg L−1 of TAN. However, haemolymph had significantly higher (P < 0.01) viral load compared to the gills and pereopods. Results showed that shrimp exposed to ammonia levels as low as 1.1 mg L−1 (TAN) had increased susceptibility to WSSV

    ESTABLISHMENT OF NEW FITTED GEOID MODEL IN UNIVERSITI TEKNOLOGI MALAYSIA

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    The purpose of this study is to produce fitted geoid for Universiti Teknologi Malaysia (UTM), Johor Bahru by using precise levelling and 3D GNSS control network technique. This study focuses on the theory, computation method and analysis of fitted geoid around Universiti Teknologi Malaysia. The computation of accuracy fitted geoid model is based on the GNSS levelling and Precise Levelling. The achieved accuracy of UTM Fitted Geoid Model is at 8&thinsp;mm. In conclusion, this research can contribute to Universiti Teknologi Malaysia by providing good UTM fitted geoid model that can give better accuracy for various purposes of work related to surveying and mapping

    Reliability of wind speed data from satellite altimeter to support wind turbine energy

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    Satellite altimeter has proven itself to be one of the important tool to provide good quality information in oceanographic study. Nowadays, most countries in the world have begun in implementation the wind energy as one of their renewable energy for electric power generation. Many wind speed studies conducted in Malaysia using conventional method and scientific technique such as anemometer and volunteer observing ships (VOS) in order to obtain the wind speed data to support the development of renewable energy. However, there are some limitations regarding to this conventional method such as less coverage for both spatial and temporal and less continuity in data sharing by VOS members. Thus, the aim of this research is to determine the reliability of wind speed data by using multi-mission satellite altimeter to support wind energy potential in Malaysia seas. Therefore, the wind speed data are derived from nine types of satellite altimeter starting from year 1993 until 2016. Then, to validate the reliability of wind speed data from satellite altimeter, a comparison of wind speed data form ground-truth buoy that located at Sabah and Sarawak is conducted. The validation is carried out in terms of the correlation, the root mean square error (RMSE) calculation and satellite track analysis. As a result, both techniques showing a good correlation with value positive 0.7976 and 0.6148 for point located at Sabah and Sarawak Sea, respectively. It can be concluded that a step towards the reliability of wind speed data by using multi-mission satellite altimeter can be achieved to support renewable energy

    The implementation of modern geocentric datum: a review

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    A dynamic datum denotes a coordinate datum in real-time linked with the International Terrestrial Reference Frame (ITRF) in order to provide a dynamic ITRF-like datum to the users. The ITRF is dynamic and updating every few years as its stations' coordinates consider the motion of earth's tectonic plate and other deformations. This paper is an effort to review the implementation of dynamic geocentric datum techniques from a few countries. An overview of dynamic geocentric datum implements Malaysia, Australia, New Zealand, Uzbekistan, Israel and Brunei will be summarized to support the future application. Thus, a review consists of a type of datum; datum parameters, reference frame and epoch will be discussed and outlined. This initiative is the significance for the advancement of the future datum development

    The presence of geophysical loadings in gps observations using general least squares approaches

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    The earth's crust undergoes natural deformation due to the geophysical loadings that consist of the earth body tide, ocean tide loading, atmospheric pressure loading and pole tide. This periodic displacement is generated by the changes of the gravitational attraction between the moon and the sun acting upon the earth's rotation, along with the temporal atmospheric changes and the variability of the ocean tide. The study of the geophysical loadings is important in the geodesy field as the magnitude of the signals is significant and can contribute to errors in space geodetic measurements such as Global Positioning System (GPS), Very-Long Baseline Interferometry (VLBI) and Altimeter. This study is conducted to evaluate the percentage of geophysical loadings in GPS observations by adopting general least square approaches. The presence of the geophysical loadings indicates that as many as 76% to 93% of the geophysical loadings signal are contained in the GPS time series. The findings reveal that earth body tide signals are more significant if compared to ocean tide loading signals because the magnitude of the earth body tide is greater than that of the ocean tide loading and it affects the coordinate system particularly at up component. Results illustrated the potential of GPS to provide the local parameters of the geophysical loadings that are beneficial for earth tidal modelling and that can be used to improve the quality of space geodetic measurements
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