Search

Since the launch of the Sentinel-1 Synthetic Aperture Radar (SAR) in 2014 by the European Space Agency (ESA), there has been renewed interest in SAR data for various application, including DEM derivation with SAR Interferometry (InSAR) technique. However, the success of the InSAR technique in deriving DEM with Sentinel-1 SAR which has been largely acknowledged in sparsely vegetated regions, remains controversial in the densely vegetated environment due to certain challenges, which have rarely been reported. The aim of this study is to highlight some of the obstacles of InSAR DEM derivation with Sentinel-1 SAR over densely vegetated humid tropical environment. Suitable Sentinel-1 image pairs over part of Johor, Peninsular Malaysia, determined in terms of perpendicular and temporal baselines using the Alaska Satellite Facility (ASF) online baseline computation tool, were downloaded from the ASF archive and processed accordingly using the Sentinel Application Platform (SNAP). Difficulty in acquiring suitable image pairs, phase decorrelation and poor coherence, and unwrapping problems are some of the encountered challenges of InSAR DEM derivation with Sentinel-1 SAR in the densely vegetated humid tropics reported in this study. This study shall provide to the geoscientific community insights on InSAR DEM derivation with Sentinel-1 SAR in densely vegetated environments and initiate discussion on the technique’s promise in such environments.

The Malaysian government implemented the Movement Control Order (MCO) from March 18 to May 13, 2020, in an effort to curb the coronavirus disease outbreak that had spread throughout the nation. Utilizing data from GOSAT, GOSAT-2, OCO-2, OCO-3, and TROPOMI, the total column-averaged dry-air mole fraction of carbon dioxide and methane (referred as XCO2 and XCH4) is employed to examine the patterns of both gases throughout the MCO as well as from the same period the prior and following year. The Inverse Distance Weighting (IDW) interpolation method is utilized in mapping the XCO2 and XCH4 for the industrial areas in Peninsular Malaysia. The results revealed that even MCO is implemented, the XCO2 and XCH4 in the industrial areas are increasing year by year. By using satellites data, the XCO2 and XCH4 from large areas can be monitored continuously.

When assessing the state of the climate system, industrial area heat (IAH) is one of the most critical variables for energy auditing. Thermal infrared (TIR) remote sensing techniques were used to track the surface temperature and microclimate impacts in an industrial environment by analysing in-situ data and their relationship with industrial features to characterise their impacts on human health and climate change. Based on TIR data, this study used an automatic detection method for industrial area heat (IAH). The IAH data is first retrieved, then the local abnormal high-temperature pixels are extracted using PIX4D software for UAV and split window for Landsat 8, and finally, the hotspot targets are identified using the spatial autocorrelation Moran's analysis tool available in the ArcGIS ESRI environment. The correlations (R2) between in-situ measurement and satellite-based industrial emissions at PGI were 0.85 with an RMSE of + 3.37 and 0.89 with an RMSE of + 1.42 at KSM. The detection accuracy of IAH methods is dominant. IAH accounted for 20% of the cool- and hot spots areas in the entire study area. The total cool-spots had a higher polygons per km2 (3.5 n/km2) value than the total hot-spots (0.6 n/km2) value, while LEVEL-3 and LEVEL-2 had the lowest values, while the highest values were always found in LEVEL-1, with approximately 50 % IAH variation between the previous and next level. Moving from the total average cool-spot to the total average hot-spot classes generally increased about 5 °C. Between the most extreme cool- and hot-spot levels (LEVEL-3) for PG in the overall industrial area, a mean IAH increase of approximately 34.7 °C and 58.5 °C was observed.

Measuring high spatial/temporal industrial heat emission (IHE) is an important step in industrial climate studies. The availability of MODIS data products provides up endless possibilities for both large-area and long-term study. nevertheless, inadequate for monitoring industrial areas. Thus, Thermal sharpening is a common method for obtaining thermal images with higher spatial resolution regularly. In this study, the efficiency of the TsHARP technique for improving the low resolution of the MODIS data product was investigated using Landsat-8 TIR images over the Klang Industrial area in Peninsular Malaysia (PM). When compared to UAV TIR fine thermal images, sharpening resulted in mean absolute differences of about 25 °C, with discrepancies increasing as the difference between the ambient and target resolutions increased. To estimate IHE, the related factors (normalized) industrial area index as NDBI, NDSI, and NDVI were examined. The results indicate that IHE has a substantial positive correlation with NDBI and NDSI (R2 = 0.88 and 0.95, respectively), but IHE and NDVI have a strong negative correlation (R2 = 0.87). The results showed that MODIS LST at 1000 m resolution can be improved to 100 m with a significant correlation R2 = 0.84 and RMSE of 2.38 °C using Landsat 8 TIR images at 30 m, and MODIS LST at 1000 m resolution can still be improved to 100 m with significant correlation R2 = 0.89 and RMSE of 2.06 °C using aggregated Landsat-8 TIR at 100 m resolution. Similarly, Landsat-8 TIR at 100 m resolution was still improved to 30 m and used with aggregate UAV TIR at 5 m resolution with a significant correlation R2 = 0.92 and RMSE of 1.38 °C. Variation has been proven to have a significant impact on the accuracy of the model used. This result is consistent with earlier studies that utilized NDBI as a downscaling factor in addition to NDVI and other spectral indices and achieved lower RMSE than techniques that simply used NDVI. As a result, it is suggested that the derived IHE map is suitable for analyzing industrial thermal environments at 1:10,000 50,000 scales, and may therefore be used to assess the environmental effect.

The focus of this paper is to evaluate the performance of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data for target detection of hydrothermal alteration zones associated with geothermal (GT) springs as proxy for narrowing areas of interest. The study employed the Per-pixel Spectral Angle Mapper (SAM) and the Sub-pixel Linear Spectral Unmixing (LSU) algorithms for spectral information extraction by using the ASTER satellite image data. In both cases, image endmember spectra specifically for kaolinite, alunite, and illite and calcite zones were selected and extracted by using the Analytical Imaging and Geophysics (AIG)-developed processing methods. The results of the analysis show that both SAM and LSU discriminated targets of interest better when employing image spectra and poorly when using library spectra. However, the Per-pixel SAM is unsuitable for target detection and more suited where the objective of the investigation is to classify whole scene and not particular targets as in this case. The LSU was found to be effective for discriminating alterations associated with the thermal springs especially where image endmember spectra are employed for analysis, thus recommended for prefeasibility mapping of GT related resources.

Sentinel-2 satellite Multispectral Image (MSI) is one of the recent advancement of satellite optical imaging for detecting and tracking oil spills. MSI equipped with enhanced radiometric and spatial resolutions, apart from relatively high temporal resolution of every 5 days revisit capability. Both systematic errors of the geometric and radiometric of level 1 and 2 data were successfully treated before any data download for users’ levels applications. As such, leaving the random errors, crucially to be minimized to enable oil spill detection and tracking due to non-discernible absolute signatures of spills against the scene background and the look-alikes. The magnitude of these random errors’ minimization and the efficacy of the MSI absolute signatures within visible bands for oil spills is very crucial. However, it is rarely reported; in fact, it is a new issue to be addressed accordingly. The calibrating tool was created with oil spill spots revealed by the official authorities. Whereas, the spill pixels are identified in the corresponding pre-processed Sentinel MSI image using region growing segmentation algorithm. These spill pixels grown were analyzed against the RGB bands, logistically regressed against the oil spill via a spectral library of the crude oil type. Originated from Arabian Gulf region with an average film thickness of 0.5 to 4 mm; reporting a calibrating function in a form gain and bias corrections for RGB bands, respectively. The results indicated that calibrated MSI spill pixels have higher correlation (r2 > 0.85, p

Variation of land cover status, like clearance of forest for agricultural (oil palm) plantation activities, may lead to rapid landscape development. Also, it may cause climate variation effects like excessive rainfall and flooding, which may result in loss of properties and lives. Agricultural (oil palm) plantation‟s dispersed canopy and the open surface of the ground compared to primary forest cause much more runoff and streamflow or discharge. Hence, this paper analyses the land-use changes and evaluate its influence on water yield using the Soil Water Assessment Tools model. Quantitative and qualitative assessment to examine the successive variation from forest to agriculture has been carried out between 2000 and 2010. The results indicate that the conversion of forest to agriculture has a significant influence on hydrological properties of the study area, which cause average water yield increase by 1.93% in the area between 2000 and 2010. Which, in turn, can lead to dryer during the dry season and wetter during rainy seasons. Furthermore, forest and water body are directly proportional. Similarly, forest and agriculture are inversely proportional with R2 > 0.85, p = 0.001. The study shows the ability of Landsat in monitoring the assessment of forest to agriculture, which causes changes in hydrology. This study offers a useful input of planning and sustainable management of surface and water resources.

These Mapping and estimation of seagrass total above-ground carbon (STAGC) using satellite-based techniques are required to fast-track the achievement of the 2020 agenda on Sustainable Development Goals (SDG) 14th. This attainment is possible as seagrass habitats provide a critical coastal ecosystem for storing blue carbon stock, sediment accumulation, fisheries production and stabilisation of coastal environment. However, seagrasses are generally declining across the globe due to anthropogenic disturbance, resulting in a prolonged growth rate of seagrasses that varies according to the species compositions. Therefore, this study aims at mapping and estimation of seagrass total above-ground carbon (STAGC) using Landsat ETM+ in the coastline of Penang. These satellite images were calibrated with Bottom Reflected Index (BRI) and Depth Invariant Index (DII) to compare the estimate of the STAGC for more accuracy. The leaving radiances of the seagrass were correlated with the corresponding in-situ measurements to predict seagrass carbon. This established relationship with BRI image shown a healthy correlation with STAGB (R2 = 0.992, p ≤ 0.001). Whereas the STAGB versus DII relationship has less accuracy (R2 = 0.955, p ≤ 0.01), adjusted R2 = 0.980 and 0.978 were recorded for both BRI and DII STAGC estimate using the logistic model. Therefore, careful management of blue carbon stock is essential, as this study shall contribute to achieving targets 14.2 and 14.5 of SDG 14th by the United Nations.

The focus of this paper is to comparatively evaluate the performance of ASTER and Hyperion data for target detection of hydrothermal alteration zones associated with geothermal (GT) springs in an unexplored savannah region. The study employed the partial subpixel unmixing Mixture Tuned Match Filtering algorithm for spectral information extraction using the multispectral and hyperspectral satellite data. In both cases, image endmember spectra specifically for kaolinite, alunite, and illite and calcite zones were selected and extracted by using the Analytical Imaging and Geophysics (AIG)-developed processing methods. The results show that the Hyperion, despite its distortions, can effectively discriminate associated alteration zones better than ASTER. Consequently, Hyperspectral data and analysis are thus recommended for use in similar unexplored regions for GT resource detection and monitoring.

The presence of the deep-water flathead, Bembradium magnoculum Kishimoto, Kawai, Tashiro et Aungtonya, 2019, from the north-eastern Indian Ocean is reported for the first time. The species was previously known only from a single specimen collected off Phuket, Thailand, eastern Andaman Sea. One specimen measuring 101 mm SL was collected by the Fishery Oceanographic Research Vessel (FORV) Sagar Sampada with a demersal trawl (HSDT crustacean version) on the insular shelf north of Car Nicobar Island, Nicobar Islands, at 362 m depth. The specimen is described, and the new distributional record from the north-eastern Indian Ocean is confirmed.

This paper proposes a smart real-time health monitoring structured for hospitals' distributor based on wearable health data sensors. Health data were received from multiple heterogeneous wearable sensors, such as electrocardiogram (ECG), oxygen saturation sensor (SpO2), blood pressure monitor, and non-sensory measurement (text frame), from 500 patients with different symptoms. Triage level and healthcare services were identified based on the new four-level remote triage and package localization (4LRTPL). The numbers of healthcare services that represent hospital status were collected from 12 hospitals located in Baghdad city. This study constructed a decision matrix based on the crossover of “multi-healthcare services” and “hospital list” within Tier 4. The hospitals were then ranked using multi-criteria decision-making (MCDM) techniques, namely, integrated analytic hierarchy process (AHP) and vlsekriterijumskaoptimizacija i kompromisnoresenje (VIKOR). Mean ± standard deviation was computed to ensure that the hospital ranking undergoes systematic ranking for objective validation. This research provided scenarios and checklist benchmarking to evaluate the proposed and existing health recommender frameworks. Results corroborated that: 1) the integration of AHP and VIKOR effectively solved hospital selection problems; 2) in the objective validation, significant differences were recognized between the scores of groups, indicating that the ranking results were identical; 3) in evaluation, the proposed framework exhibited an advantage over the benchmark framework with a percentage of 56.25%; and 4) hospitals with multiple healthcare services received the highest ranks, whereas hospitals with fewer healthcare services received low ranks.

The site preference of some transition metals during B2-type ordering has been investigated in the ternary Cu0.5(Zn1–xMx)0.5 alloys with M = Ti, V, Ag, Au, Cr, Mn, Fe, Co, Ni, Nb, Mo, Hf, Ta, W, Re or Pt (x ≤ 0.01). The statistic-o-thermodynamical theory combined with the electronic theory of alloys has been used to calculate the partial ordering energies, partial short range order parameters and the order-disorder transformation temperatures. The values of partial short range order parameters have been used to determine the site preference of the metal M. The analysis shows that the metals M can be divided into two groups with regard to lattice site occupancy. One group comprising of Cr, Mn, Fe, Co, Ni, Nb, Mo, Hf, Ta, W, Re or Pt was found to prefer Zn sublattice sites, while the second group of Ti, V, Ag or Au atoms prefer Cu sublattice sites. It is found that order-disorder transformation temperature and the site preference of metal M both depend strongly on the partial ordering energies and ternary alloying addition of metal M.

This paper surveyed the literature on the criteria of student performance in various educational domains in order to establish the coherent taxonomy and figure out the gap on this pivotal research area. The significant search for articles focused on: 1) student evaluation; 2) education-related; and 3) criteria and domain. The three reliable databases are the Web of Science, ScienceDirect, and IEEE Xplore. These databases are sufficiently broad to cover education and technical literature. The set comprised 178 articles. The biggest group (170/178) included various evaluation criteria and domains. Most domains (84/170) covered criteria, such as performance and skills. Another group (8/178) utilized surveys and reviews to characterize the evaluation criteria for specific specializations. Since 2012, researchers have investigated the process of student evaluation in several domains. Regardless of class, the challenges that prohibited the full adoption of evaluation criteria were the focus of articles and recommended mitigations. Although research areas on student evaluation differed, the results were evenly pivotal. This paper affirms the existing research and provides the supplemental areas for future work.

The recently developed pyroelectric spectroscopic technique has been used to measure the thermal diffusivity of solids. The method has been applied to conductors and insulator where by the thermal wave is measured at various lateral distances on the sample between laser illuminated line and pyroelectric sensor position. The thermal diffusivity is obtained from the gradient of the plot of thermal wave signal versus the lateral distance. A good agreement to the previously reported thermal diffusivity value has been obtained for aluminium, copper and spray paint that is 0.809 cm2s-1, 1.128 3cm2s-1 and 1.547 x 10-3 cm2s-1 respectively.

Shahr-e-Babak tract of the Kerman metalogenic belt is one of the most potential segments of Urumieh–Dokhtar (Sahand-Bazman) magmatic arc. This area encompasses several porphyry copper deposits in exploration, development and exploitation hierarchy. The aim of this study is to map hydrothermal alterations caused by early Cenozoic magmatic intrusions in Shahr-e-Babak area. To this purpose, mineral mapping methods including band combinations, ratios and multiplications as well as PCA and MNF data space transforms in SWIR and VNIR for both ASTER and OLI sensors. Alteration zones according to spectral signatures of each type of alteration mineral assemblages such as argillic, phyllic and propylitic are successfully mapped. For enhancing the target areas false color composites and HSI-RGB color space transform are performed on developed band combinations. Previous studies have proven the robust application of ASTER in geology and mineral exploration; nonetheless, the results of this investigation prove applicability of OLI sensor from landsat-8 for alteration mapping. According to the results, evidently OLI sensor data can accurately map alteration zones. Additionally, the 12-bit quantization of OLI data is its privilege over 8-bit data of ASTER in VNIR and SWIR, thus OLI high quality results, which makes it easy to distinguish targets with enhanced color contrast between the altered and unaltered rocks.

Geological investigations in Antarctica confront many difficulties due to its remoteness and extreme environmental conditions. In this study, the applications of Landsat-8 data were investigated to extract geological information for lithological and alteration mineral mapping in poorly exposed lithologies in inaccessible domains such in Antarctica. The north-eastern Graham Land, Antarctic Peninsula (AP) was selected in this study to conduct a satellite-based remote sensing mapping technique. Continuum Removal (CR) spectral mapping tool and Independent Components Analysis (ICA) were applied to Landsat-8 spectral bands to map poorly exposed lithologies at regional scale. Pixels composed of distinctive absorption features of alteration mineral assemblages associated with poorly exposed lithological units were detected by applying CR mapping tool to VNIR and SWIR bands of Landsat-8.Pixels related to Si-O bond emission minima features were identified using CR mapping tool to TIR bands in poorly mapped andunmapped zones in north-eastern Graham Land at regional scale. Anomaly pixels in the ICA image maps related to spectral featuresof Al-O-H, Fe, Mg-O-H and CO3 groups and well-constrained lithological attributions from felsic to mafic rocks were detectedusing VNIR, SWIR and TIR datasets of Landsat-8. The approach used in this study performed very well for lithological andalteration mineral mapping with little available geological data or without prior information of the study region.

Geothermal systems are essentially associated with hydrothermal alteration mineral assemblages such as iron oxide/hydroxide, clay, sulfate, carbonate and silicate groups. Blind and fossilized geothermal systems are not characterized by obvious surface manifestations like hot springs, geysers and fumaroles, therefore, they could not be easily identifiable using conventional techniques. In this investigation, the applicability of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) were evaluated in discriminating hydrothermal alteration minerals associated with geothermal systems as a proxy in identifying subtle Geothermal systems at Yankari Park in northeastern Nigeria. The area is characterized by a number of thermal springs such as Wikki and Mawulgo. Feature-oriented Principal Component selection (FPCS) was applied to ASTER data based on spectral characteristics of hydrothermal alteration minerals for a systematic and selective extraction of the information of interest. Application of FPCS analysis to bands 5, 6 and 8 and bands 1, 2, 3 and 4 datasets of ASTER was used for mapping clay and iron oxide/hydroxide minerals in the zones of Wikki and Mawulgo thermal springs in Yankari Park area. Field survey using GPS and laboratory analysis, including X-ray Diffractometer (XRD) and Analytical Spectral Devices (ASD) were carried out to verify the image processing results. The results indicate that ASTER dataset reliably and complementarily be used for reconnaissance stage of targeting subtle alteration mineral assemblages associated with geothermal systems.

Identification of high potential risk and susceptible zones for natural hazards of geological origin is one of the most important applications of advanced remote sensing technology. Yearly, several landslides occur during heavy monsoon rainfall in Kelantan River basin, Peninsular Malaysia. Flooding and subsequent landslide occurrences generated significant damage to livestock, agricultural produce, homes and businesses in the Kelantan River basin. In this study, remote sensing data from the recently launched Landsat-8 and Phased Array type L-band Synthetic Aperture Radar-2 (PALSAR-2) on board the Advanced Land Observing Satellite-2 (ALOS-2) were used to map geologic structural and topographical features in the Kelantan River basin for identification of high potential risk and susceptible zones for landslides and flooding areas. The data were processed for a comprehensive analysis of major geological structures and detailed characterizations of lineaments, drainage patterns and lithology at both regional and district scales. The analytical hierarchy process (AHP) approach was used for landslide susceptibility mapping. Several factors such as slope, aspect, soil, lithology, normalized difference vegetation index (NDVI), land cover, distance to drainage, precipitation, distance to fault and distance to the road were extracted from remote sensing satellite data and fieldwork to apply the AHP approach. Directional convolution filters were applied to ALOS-2 data for identifying linear features in particular directions and edge enhancement in the spatial domain. Results indicate that lineament occurrence at regional scale was mainly linked to the N–S trending of the Bentong–Raub Suture Zone (BRSZ) in the west and Lebir Fault Zone in the east of the Kelantan state. The combination of different polarization channels produced image maps that contain important information related to water bodies, wetlands and lithological units. The N–S, NE–SW and NNE–SSW lineament trends and dendritic, sub-dendritic and rectangular drainage patterns were detected in the Kelantan River basin. The analysis of field investigation data indicates that many of flooded areas were associated with high potential risk zones for hydrogeological hazards such as wetlands, urban areas, floodplain scroll, meander bend, dendritic and sub-dendritic drainage patterns, which are located in flat topographic regions. Numerous landslide points were located in a rectangular drainage system that is associated with a topographic slope of metamorphic and quaternary rock units. Consequently, structural and topographical geology maps were produced for Kelantan River basin using PALSAR-2 data, which could be broadly applicable for landslide hazard mapping and identification of high potential risk zone for hydrogeological hazards. Geohazard mitigation programs could be conducted in the landslide recurrence regions and flooded areas to reduce natural catastrophes leading to loss of life and financial investments in the Kelantan River basin. In this investigation, Landsat-8 and ALOS-2 have proven to successfully provide advanced Earth observation satellite data for disaster monitoring in tropical environments.

In this study, the recently launched Phased Array type L-band Synthetic Aperture Radar-2 (PALSAR-2) onboard the Advanced Land Observing Satellite-2 (ALOS-2), remote sensing data were used to map geologic structural and topographical features in the Kelantan river basin for identification of high potential risk and susceptible zones for landslides and flooding areas. A ScanSAR and two fine mode dual polarization level 3.1 images cover Kelantan state were processed for comprehensive analysis of major geological structures and detailed characterizations of lineaments, drainage patterns and lithology at both regional and district scales. Red-Green-Blue (RGB) colour-composite was applied to different polarization channels of PALSAR-2 data to extract variety of geological information. Directional convolution filters were applied to the data for identifying linear features in particular directions and edge enhancement in the spatial domain. Results derived from ScanSAR image indicate that lineament occurrence at regional scale was mainly linked to the N-S trending of the Bentong-Raub Suture Zone (BRSZ) in the west and Lebir Fault Zone in the east of the Kelantan state. Combination of different polarization channels produced image maps contain important information related to water bodies, wetlands and lithological units for the Kelantan state using fine mode observation data. The N-S, NE-SW and NNE-SSW lineament trends were identified in the study area using directional filtering. Dendritic, sub-dendritic and rectangular drainage patterns were detected in the Kelantan river basin. The analysis of field investigations data indicate that many of flooded areas were associated with high potential risk zones for hydro-geological hazards such as wetlands, urban areas, floodplain scroll, meander bend, dendritic and sub-dendritic drainage patterns, which are located in flat topograghy regions. Numerous landslide points were located in rectangular drainage system that associated with topographic slope of metamorphic and Quaternary rock units. Some large landslides were associated with N-S, NNE-SSW and NE-SW trending fault zones. Consequently, structural and topographical geology maps were produced for Kelantan river basin using PALSAR-2 data, which could be broadly applicable for landslide hazard mapping and identification of high potential risk zone for hydro-geological hazards.

Remote sensing imagery is capable to provide a solution to overcome the difficulties associated with geological field mapping in the Antarctic. Advanced optical and radar satellite imagery is the most applicable tool for mapping and identification of inaccessible regions in Antarctic. Consequently, an improved scientific research using remote sensing technology would be essential to provide new and more complete lithological and structural data to fill the numerous knowledge gaps on Antarctica’s geology. In this investigation, Oscar coast area in Graham Land, Antarctic Peninsula (AP) was selected to conduct a remote sensing study using Landsat-7 Thematic Mapper (TM), Landsat-8 and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data. Contrast-enhanced Red-Green-Blue (RGB) composites, band ratios and Relative Band Depth (RBD) image processing techniques were applied to Landsat-8 and ASTER dataset for establishing the spectral separation of the main lithologic groups exposed in the study area. The outcomes of this investigation demonstrated the applications of SWIR and TIR bands of the multispectral remote sensing datasets to identify lithological units and producing geological maps with suitable accuracy of ice-free rock regions in the Antarctic Peninsula. The results could be extended to map coverage of non-investigated regions further east and validated previously inferred geological observations concerning other rocks and mineral deposits throughout the Antarctica.

Increasing frequency, intensity, and geographic distribution of Harmful algal blooms (HABs) poses a serious threat to the coastal fish/shellfish aquaculture and fisheries in Malaysian bays. Rising in sea level, shoreline erosion, stresses on fisheries, population pressure, interference of land-use and lack of institutional capabilities for integrated management make major challenges. Recent investigations and satellite observations indicate HABs originated from specific coast that have favourable geographic, geomorphic and coastal geology conditions to bring the green macro algae from the coast offshore. Therefore, the identification of high HABs frequented bays using remote sensing and geology investigations in Malaysian waters is required to reduce future challenges in this unique case. This research implemented comprehensive geomorphic and coastal geology investigations combined with remote sensing digital image processing approach to identify Malaysian bays frequented with HABs occurrence in Malaysian waters territory. The landscape and geomorphological features of the Malaysian bays were constructed from the Phased Array type L-band Synthetic Aperture Radar (PALSAR) remote sensing satellite data combined with field observations and surveying. The samples for laboratory analysis were collected from the sediment stations with different distance across shorelines features and watersheds of the Johor Bahru estuary. This research identified that semi-enclosed bays such as Kuala Lumpur and Johor Bahru bays with connection to estuaries have high potential to be frequented with HABs occurrence.

Yearly, several landslides ensued during heavy monsoons rainfall in Kelantan river basin, peninsular Malaysia, which are obviously connected to geological structures and topographical features of the region. In this study, the recently launched Phased Array type L-band Synthetic Aperture Radar-2 (PALSAR-2) onboard the Advanced Land Observing Satellite-2 (ALOS-2), remote sensing data were used to map geological structural and topographical features in the Kelantan river basin for identification of high potential risk and susceptible zones for landslides. Adaptive Local Sigma filter was selected and applied to accomplish speckle reduction and preserving both edges and features in PALSAR-2 fine mode observation images. Different polarization images were integrated to enhance geological structures. Additionally, directional filters were applied to the PALSAR-2 Local Sigma resultant image for edge enhancement and detailed identification of linear features. Several faults, drainage patterns and lithological contact layers were identified at regional scale. In order to assess the results, fieldwork and GPS survey were conducted in the landslide affected zones in the Kelantan river basin. Results demonstrate the most of the landslides were associated with N-S, NNW-SSE and NE-SW trending faults, angulated drainage pattern and metamorphic and Quaternary units. Consequently, structural and topographical geology maps were produced for Kelantan river basin using PALSAR-2 data, which could be broadly applicable for landslide hazard mapping.

The Bentong-Raub Suture Zone (BRSZ) of Peninsular Malaysia is one of the significant structural zones in Sundaland, Southeast Asia. It forms the boundary between the Gondwana-derived Sibumasu terrane in the west and Sukhothai arc in the east. The BRSZ is also genetically related to the sediment-hosted/orogenic gold deposits associated with the major lineaments and form-lines in the central gold belt Central Gold Belt of Peninsular Malaysia. In tropical environments, heavy tropical rainforest and intense weathering makes it impossible to map geological structures over long distances. Advances in remote sensing technology allow the application of Synthetic Aperture Radar (SAR) data in geological structural analysis for tropical environments. In this investigation, the Phased Array type L-band Synthetic Aperture Radar (PALSAR) satellite remote sensing data were used to analyse major geological structures in Peninsular Malaysia and provide detailed characterization of lineaments and form-lines in the BRSZ, as well as its implication for sediment-hosted/orogenic gold exploration in tropical environments. The major geological structure directions of the BRSZ are N-S, NNE-SSW, NE-SW and NW-SE, which derived from directional filtering analysis to PALSAR data. The pervasive array of N-S faults in the study area and surrounding terrain is mainly linked to the N-S trending of the Suture Zone. N-S striking lineaments are often cut by younger NE-SW and NW-SE-trending lineaments. Gold mineralized trends lineaments are associated with the intersection of N-S, NE-SW, NNW-SSE and ESE-WNW faults and curvilinear features in shearing and alteration zones. Lineament analysis on PALSAR satellite remote sensing data is a useful tool for detecting the boundary between the Gondwana-derived terranes and major geological features associated with suture zone especially for large inaccessible regions in tropical environments.

Exploiting geothermal (GT) resources requires first and foremost locating suitable areas for its development. The focus of this paper is to explore the applicability of mapping GT related anomalies by identifying mineralogy and lithological features at regional scale using image enhancement techniques on Landsat 8 satellite data. A combination of established Band ratios from literature were implemented on Landsat 8 optical bands using innovative digital image processing and knowledge-based spectral information extraction techniques which enhanced surface mineralogy and possible alteration areas of interest. The results indicate that ratios using bands; 7/4, 6/3, 5/7 and 6/7, 4/3, 5/6 and 7/5, 5/4, 6/7 respectively as RGB, were unique but corroborative in enhancing and identifying; clay rich rocks, iron oxides, micas, carbonates and possible hydrothermal alteration zones related to GT anomaly. The results could have implication for GT exploration in especially unexplored regions where expensive airborne surveys are unaffordable. Keywords: Band ratios, Landsat 8 (OLI), Geothermal, Minerals

This research investigates the integration of the Phased Array type L-band Synthetic Aperture Radar (PALSAR) and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite data for geological mapping applications in tropical environments. The eastern part of the central belt of peninsular Malaysia has been investigated to identify structural features and mineral mapping using PALSAR and ASTER data. Adaptive local sigma and directional filters were applied to PALSAR data for detecting geological structure elements in the study area. The vegetation, mineralogic and lithologic indices for ASTER bands were tested in tropical climate. Lineaments (fault and fractures) and curvilinear (anticline or syncline) were detected using PALSAR fused image of directional filters (N-S, NE-SW, and NW-SE).Vegetation index image map show vegetation cover by fusing ASTER VNIR bands. High concentration of clay minerals zone was detected using fused image map derived from ASTER SWIR bands. Fusion of ASTER TIR bands produced image map of the lithological units. Results indicate that data integration and data fusion from PALSAR and ASTER sources enhanced information extraction for geological mapping in tropical environments.

Landsat Thematic Mapper (TM) and Shuttle Radar Topography Mission (SRTM) data were used to produce geological maps in tropical environments. Lineament, lithology and landform maps were produced for all states in peninsular Malaysia in this study. Kedah, Perak and Terengganu states have been selected as case studies to demonstrate the results of the data and techniques used. Directional filtering technique was applied to Landsat TM bands 4, 5 and 3 for lineament mapping. The lithology map was produced using Landsat TM bands combination consist of bands 4, 3 and 2. Digital elevation model and landform map were produced using SRTM data in 3 Dimension (3D) and 2 Dimension (2D) perspective views, respectively. The produced geological maps and the remote sensing data and methods applied in this study are mostly appropriate for hazard risk mapping applications and mineral exploration projects in the peninsular Malaysia and tropical environments.

This study evaluates the capability of Earth Observing-1 (EO1) Advanced Land Imager (ALI) data for hydrothermal alteration mapping in the Meiduk and Sar Cheshmeh porphyry copper mining districts, SE Iran. Feature-oriented principal components selection, 4/2, 8/9, 5/4 band ratioing were applied to ALI data for enhancing the hydrothermally altered rocks associated with porphyry copper mineralization, lithological units and vegetation. Mixture-tuned matched-filtering (MTMF) was tested to discriminate the hydrothermal alteration areas of porphyry copper mineralization from surrounding environment using the shortwave infrared bands of ALI. Results indicate that the tested methods are able to yield spectral information for identifying vegetation, iron oxide/hydroxide and clay minerals, lithological units and the discrimination of hydrothermally altered rocks from unaltered rocks using ALI data.

Studying the ophiolite complexes using multispectral remote sensing satellite data are interesting because of high diversity of minerals and the source of podiform chromitites. This research developed an approach to discriminate lithological units and detecting host rock of chromitite bodies within ophiolitic complexes using the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Landsat Thematic Mapper (TM) satellite data. Three main ophiolite complexes located in south of Iran have been selected for the study. Spectral transform techniques, including minimum noise fraction (MNF) and specialized band ratio were employed to detect different rock units and the identification of high-potential areas of chromite ore deposits within ophiolitic complexes. A specialized band ratio (4/1, 4/5, 4/7) of ASTER, MNF components and Spectral Angle Mapper (SAM) on ASTER and Landsat TM data were used to distinguish ophiolitic rock units. Results show that the specialized band ratio was able to identify different rock units and serpentinized dunite as host rock of chromitites within ophiolitic complexes, appropriately. MNF components of ASTER and Landsat TM data were suitable to distinguish ophiolitic rock complexes at a regional scale. The integration of SAM and Feature Level Fusion (FLF) used in this investigation discriminated the ophiolitic rock units and prepared detailed geological map for the study area. Accordingly, high potential areas (serpentinite dunite) were identified in the study area for chromite exploration targets.The approach used in this research offers the image processing techniques as a robust, reliable, fast and cost-effective method for detecting serpentinized dunite as host rock of chromitite bodies within vast ophiolite complexes using ASTER and Landsat TM satellite data.

The Bentong-Raub Suture Zone (BRSZ) of peninsular Malaysia was selected as case study to evaluate the capability of the Phased Array type L-band Synthetic Aperture Radar (PALSAR) satellite remote sensing data for structural geology mapping in tropical environments. The structural elements in the BRSZ were enhanced using multi-polarization configuration of PALSAR data at a regional scale. Adaptive local sigma and directional filters were applied to PALSAR data for detailed structural mapping. Numerous tectonic lineaments with consistent variation in trend, length and density were detected in the study area. Structural analysis of the BRSZ reveals that two distinct parts can be defined, a western part affected mainly by ductile fabrics in the Cameron Highlands and an eastern part affected mainly by brittle deformation in the BRSZ. Ductile deformation indicates several generation of folding in the Cameron Highlands. Several faults, joints and fractures represent brittle deformation events in the BRSZ. The results of this study demonstrate the usefulness of PALSAR satellite remote sensing data for mapping geological structures in tropical environments.

The Kinta River, draining an area of 2566 km2, originates in the Korbu Mountain in Perak, Malaysia, and flows through heterogeneous, mixed land uses ranging from extensive forests to mining, rubber and oil palm plantations, and urban development. A land use change analysis of the Kinta River catchment was carried out together with assessment of the long-term trend in rainfall and sediment fluxes. The Mann-Kendall test was used to examine and assess the long-term trends in rainfall and its relationship with the sediment discharge trend. The land use analysis shows that forests, water bodies and mining land declined whilst built and agricultural land use increased significantly. This has influenced the sediment flux of the catchment. However, most of the rainfall stations and river gauging stations are experiencing an increasing trends, except at Kinta river at Tg. Rambutan. Sediment flux shows a net erosion for the period from 1961 to 1969. The total annual sediment discharge in the Kinta River catchment was low with an average rate of 1,757 t/km2/year. From 1970 to 1985, the annual sediment yield rose to an average rate of 4062 t/km2/year. Afterwards, from 1986 to 1993, the total annual sediment discharge decreased to an average rate of 1,306 t/km2/year and increased back during the period 1994 to 2000 to 2109 t/km2/year. From 2001 to 2006 the average sediment flux rate declined to 865 t/km2/year. The decline was almost 80% from the 1970s. High sediment flux in the early 1970s is partly associated with reduced tin mining activities in the area. This decreasing trend in sediment delivery leaving the Kinta River catchment is expected to continue dropping in the future.

This paper utilized the Landsat-8 image data to map the lithology’s of Plateau state north central Nigeria. This is includes the rocks, with particular emphasis on their description and classification. We are living in geologic times and sciences that provide adequate knowledge of the natures of what we live on so as to preserve and have means of sustaining human life. Plateau State is covered by four scenes of Landsat Data, and to describe the lithology’s, each scene was processed to produce images. Two different false colour composite images of Landsat-8 (FCC 7, 5 and 3 and BR composites) in RGB were generated and used for the production of 1:100,000 geological map of the study area. The identification of predominant biotitic granitic rocks was revealed and that are distributed along the Jos-Bukuru complex and underlying almost half of the entire state. Moreover, the other rock complexes such as basalts and rhyolites volcanic rocks were also discriminated. This study indicates that Landsat-8 image data has great capability to discriminate lithological units and the production of up-to-date geological maps at regional scale and could be applicable in other regions of the African continent.

Despite simulation games (SGs) being a novel pedagogical tool that can soundly represent real environments to enhance students' learning outcomes, knowledge, and skills, there is still a lack of an overview of the current theoretical understanding of using simulation games as a pedagogical method to develop K-12 learning outcomes. Taking an explanatory perspective, we examined the recent empirical studies in simulation games through a systematic search method following the PRISMA guidelines, and then discussed the benefits, limitations, and recommendations of using simulation games in K-12 education during the period of 2016 and continued to 2021 via six databases: Web of Science, Scopus, and ScienceDirect, ERC, ERIC, IEEE. Twenty-four papers were identified as the result of the data extraction process. We identified the benefits and limitations of implementing learning games in k-12 education. Findings revealed that simulation games used as teaching tools could develop student learning outcomes across the different subjects owing to features such as learners' engagement and motivation, a safe interactive environment, and increased academic performance and achievements. An important avenue for future research is to examine a new insights into and practical advice on the meaningful inclusion of simulation games in K-12 education.

Investigating the human health effects of atmospheric particulate matter (PM) using satellite data are gaining more attention due to their wide spatial coverage and temporal advantages. Such epidemiological studies are, however, susceptible to bias errors and resulted in poor predictive output in some locations. Current methods calibrate aerosol optical depth (AOD) retrieved from MODIS to further predict PM. The recent satellite-based AOD calibration uses a mixed effects model to predict location-specific PM on a daily basis. The shortcomings of this daily AOD calibration are for areas of high probability of persistent cloud cover throughout the year such as in the humid tropical region along the equatorial belt. Contaminated pixels due to clouds causes radiometric errors in the MODIS AOD, thus causes poor predictive power on air quality. In contrary, a periodic assessment is more practical and robust especially in minimizing these cloud-related contaminations. In this paper, a simple yet robust calibration approach based on monthly AOD period is presented. We adopted the statistical fitting method with the adjustment technique to improve the predictive power of MODIS AOD. The adjustment was made based on the long-term observation (2001–2006) of PM10-AOD residual error characteristic. Furthermore, we also incorporated the ground PM measurement into the model as a weighting to reduce the bias of the MODIS-derived AOD value. Results indicated that this robust approach with monthly AOD calibration reported an improved average accuracy of PM10 retrieval from MODIS data by 50% compared to widely used calibration methods based on linear regression models, in addition to enabling further spatial patterns of periodic PM exposure to be undertaken.

We reported, for the first time, to the best of our knowledge, the production of erbium doped willemite-based glass-ceramic using waste material. In this work, a willemite-based glass-ceramic was prepared from waste material to obtain excellent crystallinity and then doped with trivalent erbium (Er3+) to yield ([(ZnO)0.5(SLS)0.5]1−x[Er2O3]x) final composition where x=3 wt%. The samples were sintered at various temperatures (500–1100°C) to study the effects of sintering temperatures on microstructure and physical properties of the samples. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) were used to determine structural changes and functional groups in the samples, respectively. Field-emission scanning electron microscopy (FE-SEM) equipped with energy dispersive X-ray was used to observe surface morphology and to detect presence of elements in the samples. Findings showed that average grain size of the Er3+ doped glass-ceramic sample increased as a function of the sintering temperature and the optimum temperature was 900°C.

Polycrystalline samples with the chemical formula CaCu3Ti4-xZrxO12 (x=0, 0.02, 0.1, 0.2, 0.5, and 0.1) CCTZO were synthesized from metal nitrate solutions by the sol-gel method, followed by conventional and microwave heat treatments. The X-ray diffraction pattern of powder calcined at 800°C in conventional furnace for 3 h showed formation of a single phase. The crystal structure did not change on doping with zirconium and it remained cubic in the five studied compositions. The surface morphology of samples sintered at 1000°C in microwave furnace for 10 min was observed using a high resolution scanning electron microscope (HR-SEM). The grain sizes were in the range of 250 nm–5 μm for these samples. HRSEM results show that doping with Zr enhanced grain growth or densification. Energy dispersive X-ray spectroscopy (EDX) confirmed the presence of Zr. The dielectric characteristics of Zr doped CCTO were studied with an LCR meter in the frequency range of 50 Hz–1 MHz. A very high dielectric constant 21,500 was observed for the sample doped with Zr (0.02 mol%) at 50 Hz.

In order to study the response of human breast cancer cells' exposure to nanoparticle, iron oxide (α-Fe2O3) nanoparticles were synthesized by a simple low temperature combustion method using Fe(NO3)3·9H2O as raw material. X-ray diffraction studies confirmed that the resultant powders are pure α-Fe2O3. Transmission electron microscopy study revealed the spherical shape of the primary particles, and the size of the iron oxide nanoparticles is in the range of 19 nm. The magnetic hysteresis loops demonstrated that the sample exposed ferromagnetic behaviors with a relatively low coercivity. The cytotoxicity of α-Fe2O3 nanoparticle was also evaluated on human breast cancer cells to address the current deficient knowledge of cellular response to nanoparticle exposure.