22 research outputs found
Reliability of wind speed data from satellite altimeter to support wind turbine energy
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
Exploring spatio-temporal wave pattern using unsupervised technique
The sea waves are the up and down movements of water in the sea. The various heights of sea waves are known as significant wave heights. Each type of wave has their own characteristics based on their significant wave heights. The aim of this research is to explore spatio-temporal wave patterns and their effects on Tok Jembal coastal areas. For this study, the monthly wave data were obtained from the satellite altimeters that have been processed using Radar Altimeter Database System (RADS). The Self Organizing Map (SOM) method was used to extract the spatio-temporal wave height patterns from the monthly wave height data. From the clustering results, six number of clusters were extracted and then each of these clusters was categorized into specific type of wave heights. In addition, time series of Landsat satellite images were used to observe the coastal changes at Tok Jembal areas. Finally, we analyzed the effects of spatio-temporal wave patterns towards the occurrences of coastal erosion along the coastal areas. This study has discovered that the wave heights along the coastal areas fall in slight category and showed less effects on the erosion. From the visual interpretation of time- series images (10 years gap) also proved that the erosion can be considered as moderate. Overall, this study could benefit the coastal management especially for shoreline monitoring where early action can be taken when there are signs of erosion along the coast
Mothers' beliefs about infant teething in Enugu, South-east Nigeria: a cross sectional study
<p>Abstract</p> <p>Background</p> <p>Parents and Health Care Workers have traditionally attributed a variety of symptoms to teething in young children. Some of these symptoms may however connote underlying serious medical condition in a child. There is little evidence to support these beliefs despite their implications on management of a symptomatic teething child. This study therefore seeks determine the beliefs and problems mothers associate with teething in Enugu, South-east Nigeria.</p> <p>Findings</p> <p>A cross-sectional survey involving sixty mothers presenting at a Children's clinic in Enugu metropolis using questionnaire. More than 90% of the respondents thought that babies can experience medical problems as a result of teething. The commonest medical problems perceived to be associated with teething were fever (71.7%), loose stools (58.3%) and vomiting (35%).</p> <p>Conclusion</p> <p>Mothers still associate a variety of symptoms of childhood illnesses to teething and this association is not evidence based and could lead to delayed interventions, increased morbidity and mortality of children. It is important therefore that mothers and health workers caring for young children are educated on the need to seek prompt medical attentions in a symptomatic child.</p
Functional implant prosthodontic score of a one-year prospective study on three different connections for single-implant restorations
Aim The aim of this prospective clinical trial was to analyze, using the Functional Implant Prosthodontic Score (FIPS), the clinical resultsof three different abutment-implant connections (1 hexagon vs 2 conical types) single-unit restorations after one year of clinical service.
Material and methods Thirty patients were restored with cement-retained crowns on soft tissue level implants (10 TTc Windmix, 10 TTk Windmix and 10 Aadva GC) in posterior sites and followed-up for 1 year. FIPS was applied for objective outcome assessment beside clinical and radiographic examinations. Five variables were defined for evaluation, resulting in a maximum score of 10 per implant restoration. The patients’ level of satisfaction was recorded and correlated with FIPS.
Results All implants and connected crowns revealed survival rates of 100% without any biological or technical complications after three years of loading. The total FIPS recorded for group 1 was 44, 43 in group 2 and 42 in group 3. The mean total FIPS score was 8.6±1.1, ranging from 6 to 10. The variable “bone” revealed the highest scores (2.0; range: 2–2), as well “occlusion” (2.0; range: 2–2). Mean scores for “design” (1.7 ±0.4; range: 1–2), “mucosa” (1.6±0.5; range: 1–2), and “interproximal” (1.5±0.6; range: 1–2) were more challenging to satisfy. The patients expressed a high level of functional satisfaction (80.5±2.5; range: 65–100). No type of connection showed to be superior to the other two. No statistically significant differences were found among the three tested groups. A significant correlation was found between FIPS and the subjective patients’ perception with a coefficient of 0.80 (P < 0.0001).
Conclusions The findings of the clinical trial indicated the great potential of both conical and hexagon connections and their good performance after 1 year of clinical service. FIPS showed to be an objective and reliable instrument to assess implant success
ASSESSMENT OF SEASONAL VARIABILITY FOR WIND SPEED AND SIGNIFICANT WAVE HEIGHT USING SATELLITE ALTIMETER OVER MALAYSIAN SEAS
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
ESTABLISHMENT OF NEW FITTED GEOID MODEL IN UNIVERSITI TEKNOLOGI MALAYSIA
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 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
Cucumeropsis mannii seed oil ameliorates Bisphenol‐A‐induced adipokines dysfunctions and dyslipidemia
From Wiley via Jisc Publications RouterHistory: received 2022-12-25, rev-recd 2023-01-07, accepted 2023-02-06, pub-electronic 2023-02-18Article version: VoRPublication status: PublishedThis study demonstrated the therapeutic potentials of Cucumeropsis mannii seed oil (CMSO) capable of alleviating BPA‐induced dyslipidemia and adipokine dysfunction. In this study, we evaluated the effects of CMSO on adipokine dysfunctions and dyslipidemia in bisphenol‐A (BPA)‐induced male Wistar rats. Six‐week‐old 36 albino rats of 100–200 g weight were assigned randomly to six groups, which received varied doses of BPA and/or CMSO. The administration of BPA and CMSO was done at the same time for 42 days by oral intubation. The adipokine levels and lipid profile were measured in adipose tissue and plasma using standard methods. BPA induced significant (p < .05) increases in triglycerides, cholesterol, leptin, LDL‐C, and atherogenic and coronary risk indices in adipose tissue and plasma, as well as a decrease in adiponectin and HDL‐C levels in Group II animals. BPA administration significantly (p < .05) elevated Leptin levels and reduced adiponectin levels. BPA plus CMSO reduced triglycerides, cholesterol, leptin, LDL‐C, and atherogenic and coronary risk indices while increasing adiponectin levels and HDL‐C in adipose tissue and plasma (p < .05). The results showed that BPA exposure increased adipose tissue as well as serum levels of the atherogenic index, triglycerides, cholesterol, coronary risk index, LDL‐C, leptin, and body weight with decreased adiponectin levels and HDL‐C. Treatment with CMSO reduced the toxicities caused by BPA in rats by modulating the body weight, adiponectin/leptin levels, and lipid profiles in serum and adipose tissue. This study has shown that CMSO ameliorates BPA‐induced dyslipidemia and adipokine dysfunctions. We suggest for further clinical trial to establish the clinical applications
Assessment of satellite altimeter's dual frequency ionospheric delay in tropical regions compared to global ionospheric models
The rapid development of satellite altimeters has brought about a remarkable feat of innovation in the field of ionosphere studies as they can measure the ionosphere using an on-board instrument called dual frequency sensor. Some methods that can be used to measure the ionosphere are by using satellite altimeters, Global Positioning Systems (GPS), and Ionosondes. Most of the wellknown agencies such as NASA and ESA are working hard to study the ionosphere by producing their own Global Ionospheric Models (GIMs). However, factors like point based monitoring techniques and the scarcity of monitoring stations in tropical regions could deteriorate the quality of these GIMs. This study aimed to assess the performance of the satellite altimeter derived ionospheric delay compared to GIMs over tropical regions especially in Malaysian Seas. Three GIMs were used for the purpose of this study namely the IRI2007, Jet Propulsion Lab (JPL) GIM and the NOAA Ionosphere Climatology 2009 (NIC09). This study used the Radar Altimeter Database System (RADS) to extract ionospheric corrections from Malaysian seas. The expected result was to evaluate the ionospheric delay pattern in marine areas in tropical regions from 2009 until 2016. It was found that the performance of the satellite altimeter's ionospheric delay works best with the IRI2007 with a root mean square error (RMSE) value of 1.1115cm. Furthermore, the data from satellite altimeter was in a good understanding with the latitudinal variation of the ionosphere since the study area's ionosphere is characterized by the presence of the Equatorial Ionospheric Anomaly (EIA) and a strong amplitude magnetic signature of the equatorial electrojet (EEJ). In conclusion, satellite altimetry could be a useful data source for the under observed areas such as the tropical regions
Interpretation of atmospheric wet delay in the tropical region using space-based radiometer system
Due to the inherent advantages of monitoring from space, and developments in sensor technology, satellite altimeters have brought about a revolution in the field of weather forecasting as they can measure atmospheric conditions using an onboard instrument called a passive microwave radiometer over the ocean areas. Since tropospheric wet delay in the atmosphere is one of the limiting factors to satellite altimeter measurement range, it is important for weather and climate predictions. The methods that can be used to measure wet delay are satellite altimeter, Global Positioning Systems (GPS), and Radiosonde. Weather satellites offer some potential advantages over conventional methods as they can cover marine areas, whereas conventional weather networks cover only about 20% of the globe, which are land areas using point -based solutions. A combination of these methods will improve tropospheric wet delay studies. The focus of this study was to evaluate wet delay data using radiometer measurements for tropical regions. The 10 altimeter missions used for this study consisted of ERS-1, ERS-2, Envisat, Jason-1, Jason-2, Jason-3, SARAL, Sentinel, TOPEX, and Poseidon. This study used the Radar Altimeter Database System or RADS to extract wet tropospheric corrections from radiometer measurements in the Malaysian region. The expected result was to evaluate the wet delay pattern in marine areas in tropical regions during the monsoon season. This study would also verify wet delay data from satellite altimeters with GPSderived data at 12 GPS MyRTKnet Stations in Malaysia and the European Centre for Medium- Range Weather Forecast (ECMWF) Global Tropospheric model. The verification results showed that the RMSE between altimetry-derived wet delay with GPS-derived wet delay and the ECMWF model were both about 1cm to 15cm. The observed data also gave reasonable values for the wet and dry seasons because the MyRTKnet and the ECMWF model from satellite altimeters only had slight differences. Altimetry-derived wet delay studies are very important to climate and weather forecasting and many kinds of research in marine areas and tropical regions
Analysis of upwelling events in the southern South China Sea using multi-mission satellite altimeter
Upwelling is a vital ocean behaviour, especially for the Fisheries Industry, where upwelling will help to detect fish ground at a particular ocean area. However, the study of upwelling is minimal and not well understood due to some reasons and constraints, such as limited observation. Upwelling lacks a comprehensive in-situ observation system where it relies on limited information collected from the ground-truthing execution such as ships, buoys, and current meter. This study aims to analyse the upwelling pattern in the southern region of the South China Sea by using a multi-mission satellite altimeter. In order to derive the physical oceanography that involves upwelling, such as sea surface height (SSH), Mean Dynamic Topography (MDT), and the Sea Level Anomaly (SLA), the Radar Altimeter Database System is used. Five Satellite Altimeter mission is used in this study, which is JASON-2, JASON-3, CYROSAT2, SARAL, SENTINAL3A from 2013 to 2017. Validation is made using a statistical method showing a good correlation between Altimetry data and Tidal Data at tide gauge, which is 0.84 to 0.97, respectively. Also, monthly altimetry derived Geostrophic Current was assessed by analysing the current pattern where it shows a similarity with a previous study where the current velocity is 0.5ms-1 to 2ms-1. From the result, eddies can be seen in the seasonal and monthly Absolute Geostrophic Ocean Current (AGOC) map, indicating the present presence of upwelling. In conclusion, this study will benefit other researchers in terms of both upwelling and eddy studies