2,468 research outputs found
Monthly and Diurnal Variability of Rain Rate and Rain Attenuation during the Monsoon Period in Malaysia
Rain is the major source of attenuation for microwave propagation above 10 GHz. In tropical and equatorial regions where the rain intensity is higher, designing a terrestrial and earth-to-satellite microwave links is very critical and challenging at these frequencies. This paper presents the preliminary results of rain effects in a 23 GHz terrestrial point-to-point communication link 1.3km long. The experimental test bed had been set up at Skudai, Johor Bahru, Malaysia. In this area, a monsoon equatorial climate prevails and the rainfall rate can reach values well above 100mm/h with significant monthly and diurnal variability. Hence, it is necessary to implement a mitigation technique for maintaining an adequate radio link performance for the action of very heavy rain. Since we now know that the ULPC (Up Link Power Control) cannot guarantee the desired performance, a solution based on frequency band diversity is proposed in this paper. Here, a secondary radio link operating in a frequency not affected by rain (C band for instance) is placed parallel with the main link. Under no rain or light rain conditions, the secondary link carries without priority radio signals. When there is an outage of the main link due to rain, the secondary link assumes the priority traffic. The outcome of the research shows a solution for higher operating frequencies during rainy events
MOLECULAR CHARACTERIZATION BY USING RANDOM AMPLIFIED POLYMORPHIC DNA (RAPD) ANALYSIS OF SALMONELLA ENTERITIDIS ISOLATES RECOVERED FROM AVIAN AND HUMAN SOURCES
Random amplified polymorphic DNA (RAPD) analysis was applied for molecular characterization of five Salmonella enteritidis strains from different avian sources and human cases of infection. A total of 16 primers were used and only five primers showed good discriminatory power for all five isolates. Dendrogram showed a common lineage among all five isolates. There was a close genetic relationship among isolates of eggs and human sources, while there was less pronounced homology among isolates of broiler meat and human sources. On the basis of results we have found that an endemic strain of S. enteritidis is prevalent between the poultry derived food and humans which gives us an insight to genetic diversity of S. enteritidis from these sources
Green and Sustainable Commercial Property Demand in Malaysia and Nigeria
Green building is redefining real estate practices and commercial properties are attracting greater attention of the paradigm shift. Nevertheless, in many countries including Malaysia and Nigeria, green building investment is still beset with uncertainties about the anticipated returns and benefits. The aim of this study is to identify the predictive factors and variables that motivate decisions to demand and invest in green commercial properties, and to apply discriminant analysis technique to assess if there are significant differences in perception between the real estate development team in Malaysia and Nigeria based on the identified variables. The result showed a significant discriminant function separating the two countries based on their perception of the variables. The green building motivation attributes favoured Malaysia. The Wilks’ Lambda’s F test and the standardized discriminant function coefficients, indicated that there are significant differences in perception between the real estate development team in Malaysia and Nigeria as measured by personal and altruistic environmental motivations, corporate conscience responsibility motivations and economic and financial motivations. However, economic and financial motivation variables were found to have showed the most predictive power in accounting for the differences in perception. Keywords: green building, real estate investment, sustainability, motivations, perceptions
PREPARATION OF CONJUGATE FOR USE IN AN ELISA FOR HUMORAL IMMUNE RESPONSE AGAINST EGG DROP SYNDROME VIRUS IN LAYER CHICKS
An indirect enzyme-linked immunosorbent assay (ELISA) was performed for the detection of antibodies against Egg Drop Syndrome (EDS) virus. Virus identification was done through haemaggluti- nation inhibition (HI) test using known antisera. Antichicken immunoglobulins were raised in goats and purified by ammonium sulphate precipitation technique. These goat-antichicken immunoglobulins were conjugated with horseradish peroxidase. Twenty-seven serum samples were collected from a layers flock vaccinated against EDS and specific antibodies were determined by using a horseradish conjugate
CO2 methanation over mesoporous silica based catalyst: a comprehensive study
The abundance presence of CO2 released into the atmosphere has gained numerous consideration for an effective method to mitigate the CO2 build up and recycling the carbon resource. Among the catalytic reactions, the methanation of CO2 has been an indispensable reaction to transform toxic CO2 into methane which can be use as energy carrier or valuable chemical. The application of heterogeneous catalyst in CO2 methanation plays a significant role due to its effectiveness and stability which led to lower costs for large scale production. This article discussed the recent developments of silica based catalyst for CO2 methanation with emphasized on its physicochemical properties and catalytic performance. In summary, the nature of silica support material such as morphology, textural properties and nature of basicity has a great influence on its catalytic performance towards CO2 methanation
MAPPING OF HIGHLY HETEROGENEOUS URBAN STRUCTURE TYPE FOR FLOOD VULNERABILITY ASSESSMENT
Vulnerability plays an important role in risk assessment. For flood vulnerability assessment, the map and characteristics of elements-at-risk at different scales are strongly required depending on the risk and vulnerability assessment requirements. This study proposes a methodology to classify urban structure type by combining object-based image classification and different high resolution remote sensing data. In this study, a high resolution satellite image and LiDAR have been acquired over Kota Bharu, Kelantan which consists of highly heterogeneous urban structure type (UST) classes. The first stage is data pre-processing that includes orthorectification and pansharpening of Geoeye satellite image, image resampling for normalised Digital Surface Model (nDSM) and followed by image segmentation for creating meaningful objects. The second stage comprises of derivation of image features, generation of training and testing datasets, and classification of UST. The classification was based on three types of machine learning classifiers, i.e. Random Forest (RF), Support Vector Machine (SVM) and Classification and Regression Tree (CART). The results obtained from the classification processes were compared using individual omission and commission error, overcall accuracy and Kappa coefficient. The results show that Random Forest classifier with all image features achieved the highest overall accuracy (93.5%) and Kappa coefficient (0.94). This is followed by CART classifier with overall accuracy of 93.7% and Kappa coefficient of 0.92. Finally, SVM classifier produced the lowest overall accuracy and Kappa coefficient with 88.6% and 0.86, respectively. The UST classification result can be further used to assist detailed building characterisation for large scale flood vulnerability assessment
Impact of integrated community-facility interventions model on neonatal mortality in rural Bangladesh- a quasi-experimental study
Background Neonatal mortality remains unacceptably high in many countries. WHO recommends that all newborns be assessed during the postnatal period and should seek prompt medical care if there is any danger sign. However, in many developing countries, only a small proportion of women receive postnatal care. Also, the quality of care in public health facilities is suboptimal. Methods We designed an intervention package that included community health worker-assisted pregnancy and birth surveillance, post-natal visits to assess newborns on the first, third, seventh and twenty-eighth days of birth, referral for facility-based care, and establishing a newborn stabilization unit at the first level referral health facility. We did a quasi-experimental, propensity-score matched, controlled study in the Sylhet region of Bangladesh. We used a cross-sectional survey method at baseline and endline to measure the effect of our intervention. We considered two indicators for the primary outcome–(a) all-cause neonatal mortality rate and (b) case fatality of severe illness. Secondary outcomes were the proportion of neonates with signs and symptoms of severe illness who sought care in a hospital or a medically qualified provider. Results Our sample size was 9,940 live births (4,257 at baseline, 5,683 at end line). Our intervention was significantly associated with a 39% reduction (aRR = 0.61, 95% CI: 0.40–0.93; p = 0.046) in the risk of neonatal mortality and 45% reduction (aRR = 0.55, 95% CI: 0.35–0.86; p = 0.001) in the risk of case fatality of severe illness among newborns in rural Bangladesh. The intervention significantly increased the care-seeking for severe illness at the first-level referral facility (DID 36.6%; 95% CI % 27.98 to 45.22; p<0.001). Interpretation Our integrated community-facility interventions model resulted in early identification of severely sick neonates, early care seeking and improved treatment. The interventions led to a significant reduction in all-cause neonatal mortality and case fatality from severe illness
Ab initio prediction of pressure-induced structural phase transition of superconducting FeSe
External pressure driven phase transitions of FeSe are predicted using
\textit{ab initio} calculations. The calculations reveal that -FeSe
takes transitions to NiAs-type, MnP-type, and CsCl-type FeSe. Transitions from
NiAs-type to MnP-type and CsCl-type FeSe is also predicted. MnP-type FeSe is
also found to be able to transform to CsCl-type FeSe, which is easier from
-FeSe than the transition to MnP-type FeSe, but comparable to the
transition from NiAs-type FeSe. The calculated electronic structures show that
all phases of FeSe are metallic, but the ionic interaction between Fe-Se bonds
becomes stronger and the covalent interaction becomes weaker when the
structural phase transition occurs from -FeSe to the other phases of
FeSe. The experimentally observed decrease in of superconducting
-FeSe at high pressure may be due to a structural/magnetic instability,
which exists at high pressure. The results suggest us to increase the
of -FeSe if such phase transitions are frustrated by suitable methods.Comment: Accepted for publications in J. Phys.: Condens. Matter (2012
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