16 research outputs found
Dope-Dyeing of Polyvinyl Alcohol (PVA) Nanofibres with Remazol Yellow FG
The lack of aesthetic properties of electrospun nanofibres in terms of colour appearance is the drive in this preliminary study. This research is conducted to study the dyeing behaviour and colorimetric properties of electrospun nanofibres blended with Remazol Yellow FG reactive dye using dope-dyeing method via electrospinning process. This paper reports the colorimetric properties of dyed poly vinyl alcohol (PVA) nanofibres within the range of 2.5 wt.% to 12.5 wt.% dye content. The electrospinning parameters were fixed at the electrospinning distance of 10 cm, constant feed rate of 0.5 mL/h and applied voltage of 15 kV. The resulting impregnated dye of 10 wt.% exhibits acceptable colour difference of dyed PVA nanofibres, with a mean fibre diameter of 177.1 ± 11.5 nm. The SEM micrographs show the effect of dye content on morphology and fibre diameter upon the increment of dye used. Further increase of dye content adversely affects the jet stability during the electrospinning, resulting in macroscopic dropping phenomenon. The presence of all prominent peaks of Remazol dye in the PVA nanofibers was supported with FTIR analysis. The addition of dye into the nanofibres has resulted in the enhancement of thermal stability of the PVA as demonstrated by TGA analysi
Flood Prediction Using Geographical Information System (GIS) Application at Sungai Sembrong
The occurrence of flood disaster in Malaysia has received much attention due to its negative impact towards society, environment and economy. In hydrological field, researchers are interested in flood prediction analysis and it is no longer a stranger in this area. The latest flood incident that hit Sg. Sembrong, Batu Pahat, Johor, Malaysia in 2007 is considered as the worst flood occurrence in Johor. This study focused on the effectiveness of using Geographical Information System (GIS) to predict flood at Sg. Sembrong. The combination of hydrological model and water balance model that takes into consideration the minimum, maximum and average temperature data for January 2007 is used to illustrate the predicted flood area for future reference. The results from the analysis showed that flood does not occur at the minimum and average rainfall, 17.2mm and 2mm respectively. However, with the maximum rainfall of 203mm, it is expected that 9983ha of land will be affected with 2m water level rise. In can be concluded that GIS is a suitable tool for the provision of preliminary information of flood, and it can be a powerful tool in aiding flood analysis, problem solving and provides rational, accurate and efficient decision making
Volumetric change calculation for a rock quarry using UAV photogrammetry
Nowadays, the volume calculation of rock quarry is incorrect and a slow process because it is manually conducted. To improve this performance, the use of Unmanned Aerial Vehicles (UAV) Photogrammetry shall be applied to obtain exact area mapping, volume data of rock quarry for active, non-active area and 6 total stockpiles and to verify soil profile of quarry area. The area which conducts rock excavation is known as active area whereas a non-active will be explore in the following 2 years. Meanwhile, the total 6 stockpile is the 6 different quarry rocks. The UAV is a type of photogrammetry that allow for the effective monitoring or mapping of large areas of land and existing infrastructure within a very short time compared to conventional techniques. The best of UAV is it can take the whole image of quarry area. Given that the main idea of the research presented here is to develop new applications to calculate the volume of rock quarry area. In this study, there are three main stages that need to be accomplished to get the data. The first stage is flying the UAV and capturing image at the quarry, followed by image processing and transform it into a 3D map and final stage is to calculate the volume and the determining the soil profile and contour of the quarry. To classify the materials, a DJI Phantom 4 Pro was used to fly over a quarry area in Min Fong Quarry Sdn. Bhd. This image can be transfer to pix4DMapper and Global Mapper software to produce a mapping area of quarry. Then, the calculation of the volume of rock quarry was conducted and obtain the soil profile of that study area. This observation took 2 months periodically to oversee the volumetric change in the rock quarry. The result of analysis showed that, there were differences and decreasing in the volume of rock quarry for each month
Field evaluation of infiltration models under oil palm plantation with reference to stemflow & througfall areas
Sensitivity analysis of a FAO penman monteith for potential evapotranspiration to climate change
Sensitivity of the FAO Penman-Monteith (FPM) potential evapotranspiration (PET) model under tropical climates has been studied in the present study. A total of 17 meteorological stations covering Peninsular Malaysia starting from 1987-2003 were used as model inputs. A sensitivity analysis (SA) was carried out using the graphical method for temperature, wind speed and solar radiation within the possible range of ±20% with increments of 5%. From the comparison done on the sensitivity of PET to climatic change, the Kuala Krai station gave the highest percentage change in terms of temperature (±6%). The highest percentage change for wind speed (±2%) and solar radiation (±17%) were shown at the Alor Setar and Kuala Krai stations, respectively. The Alor Setar station had the lowest percentage change for temperature (±0.3%) and solar radiation (±9.9). The lowest percentage change of wind speed (± 0.2%) was observed at the Kuala Krai station. PET percentage changes have a positive correlation to the percentage change of all climatic variables except for the Cameron Highlands station. Results revealed that solar radiation has the most significant effect on PET (±14%), followed by temperature (±4%) and wind speed (±1%). Taken together, these results suggest that solar radiation plays an important role in estimating PET in Peninsular Malaysia
Study on The Effectiveness of Egg Tray and Coir Fibre as A Sound Absorber
Sound or noise pollution has become one major issues to the community especially those who lived in the urban areas. It does affect the activity of human life. This excessive noise is mainly caused by machines, traffic, motor vehicles and also any unwanted sounds that coming from outside and even from the inside of the building. Such as a loud music. Therefore, the installation of sound absorption panel is one way to reduce the noise pollution inside a building. The selected material must be a porous and hollow in order to absorb high frequency sound. This study was conducted to evaluate the potential of egg tray and coir fibre as a sound absorption panel. The coir fibre has a good coefficient value which make it suitable as a sound absorption material and can replace the traditional material; syntactic and wooden material. The combination of pyramid shape of egg tray can provide a large surface for uniform sound reflection. This study was conducted by using a panel with size 1 m x 1 m with a thickness of 6 mm. This panel consist of egg tray layer, coir fibre layer and a fabric as a wrapping for the aesthetic value. Room reverberation test has been carried to find the loss of reverberation time (RT). Result shows that, a reverberation time reading is on low frequency, which is 125 Hz to 1600 Hz. Within these frequencies, this panel can shorten the reverberation time of 5.63s to 3.60s. Hence, from this study, it can be concluded that the selected materials have the potential as a good sound absorption panel. The comparison is made with the previous research that used egg tray and kapok as a sound absorption panel
Study on The Effectiveness of Egg Tray and Coir Fibre as A Sound Absorber
Sound or noise pollution has become one major issues to the community especially those who lived in the urban areas. It does affect the activity of human life. This excessive noise is mainly caused by machines, traffic, motor vehicles and also any unwanted sounds that coming from outside and even from the inside of the building. Such as a loud music. Therefore, the installation of sound absorption panel is one way to reduce the noise pollution inside a building. The selected material must be a porous and hollow in order to absorb high frequency sound. This study was conducted to evaluate the potential of egg tray and coir fibre as a sound absorption panel. The coir fibre has a good coefficient value which make it suitable as a sound absorption material and can replace the traditional material; syntactic and wooden material. The combination of pyramid shape of egg tray can provide a large surface for uniform sound reflection. This study was conducted by using a panel with size 1 m x 1 m with a thickness of 6 mm. This panel consist of egg tray layer, coir fibre layer and a fabric as a wrapping for the aesthetic value. Room reverberation test has been carried to find the loss of reverberation time (RT). Result shows that, a reverberation time reading is on low frequency, which is 125 Hz to 1600 Hz. Within these frequencies, this panel can shorten the reverberation time of 5.63s to 3.60s. Hence, from this study, it can be concluded that the selected materials have the potential as a good sound absorption panel. The comparison is made with the previous research that used egg tray and kapok as a sound absorption panel
Flood prediction using Geographical Information System (GIS) application at Sungai Sembrong
The occurrence of flood disaster in Malaysia has received much attention due to its negative impact towards society, environment and economy. In hydrological field, researchers are interested in flood prediction analysis and it is no longer a stranger in this area. The latest flood incident that hit Sg. Sembrong, Batu Pahat, Johor, Malaysia in 2007 is considered as the worst flood occurrence in Johor. This study focused on the effectiveness of using Geographical Information System (GIS) to predict flood at Sg. Sembrong. The combination of hydrological model and water balance model that takes into consideration the minimum, maximum and average temperature data for January 2007 is used to illustrate the predicted flood area for future reference. The results from the analysis showed that flood does not occur at the minimum and average rainfall, 17.2mm and 2mm respectively. However, with the maximum rainfall of 203mm, it is expected that 9983ha of land will be affected with 2m water level rise. In can be concluded that GIS is a suitable tool for the provision of preliminary information of flood, and it can be a powerful tool in aiding flood analysis, problem solving and provides rational, accurate and efficient decision making
Low serum high density lipoprotein cholesterol concentration is an independent predictor for enhanced inflammation and endothelial activation.
BACKGROUND:Inflammation, endothelial activation and oxidative stress have been established as key events in the initiation and progression of atherosclerosis. High-density lipoprotein cholesterol (HDL-c) is protective against atherosclerosis and coronary heart disease, but its association with inflammation, endothelial activation and oxidative stress is not well established. OBJECTIVES:(1) To compare the concentrations of biomarkers of inflammation, endothelial activation and oxidative stress in subjects with low HDL-c compared to normal HDL-c; (2) To examine the association and correlation between HDL-c and these biomarkers and (3) To determine whether HDL-c is an independent predictor of these biomarkers. METHODS:422 subjects (mean age±SD = 43.2±11.9 years) of whom 207 had low HDL-c concentrations (HDL-c <1.0 mmol/L and <1.3 mmol/L for males and females respectively) and 215 normal controls (HDL-c ≥1.0 and ≥1.3 mmol/L for males and females respectively) were recruited in this study. The groups were matched for age, gender, ethnicity, smoking status, diabetes mellitus and hypertension. Fasting blood samples were collected for analysis of biomarkers of inflammation [high-sensitivity C-reactive protein (hsCRP) and Interleukin-6 (IL-6)], endothelial activation [soluble Vascular Cell Adhesion Molecule-1 (sVCAM-1), soluble Intercellular Adhesion Molecule-1 (sICAM-1) and E-selectin)] and oxidative stress [F2-Isoprostanes, oxidized Low Density Lipoprotein (ox-LDL) and Malondialdehyde (MDA)]. RESULTS:Subjects with low HDL-c had greater concentrations of inflammation, endothelial activation and oxidative stress biomarkers compared to controls. There were negative correlations between HDL-c concentration and biomarkers of inflammation (IL-6, p = 0.02), endothelial activation (sVCAM-1 and E-selectin, p = 0.029 and 0.002, respectively), and oxidative stress (MDA and F2-isoprostane, p = 0.036 and <0.0001, respectively). Multiple linear regression analysis showed HDL-c as an independent predictor of IL-6 (p = 0.02) and sVCAM-1 (p<0.03) after correcting for various confounding factors. CONCLUSION:Low serum HDL-c concentration is strongly correlated with enhanced status of inflammation, endothelial activation and oxidative stress. It is also an independent predictor for enhanced inflammation and endothelial activation, which are pivotal in the pathogenesis of atherosclerosis and atherosclerosis-related complications