Scientia Bruneiana最新文献

{"title":"The dynamic avifaunal assemblage of a fragmented urbanised habitat at Universiti Brunei Darussalam","authors":"Haslina Razali, Remya Kottarathu Kalarikkal, Guat Lian Ang, Ulmar Grafe","doi":"10.46537/scibru.v21i1.135","DOIUrl":"https://doi.org/10.46537/scibru.v21i1.135","url":null,"abstract":"Urbanisation reshapes ecosystems and fundamentally influences species assemblages. Urban habitats are also highly dynamic with changes taking place on both spatial and temporal scales. The campus of Universiti Brunei Darussalam is an example of an urban habitat consisting of a mosaic of green spaces, fragments of kerangas forest, planted native and ornamental plants as well as building infrastructure, roads and pathways. The aim of this study is to provide an insight into the bird assemblages found within the university campus. Two survey periods were conducted in 2006/2007 and in 2019/2020 using the line transect method. A total of 49 bird species belonging to 23 families and 10 orders were recorded in this study. No evidence of differences in species richness was observed between the two surveys after exclusion of migrants. Insectivores were the most species-rich followed by omnivores, granivores, carnivores and frugivores. As predicted, there was a higher number of non-forest dependent bird species than forest-dependent species. Vegetation cover was lower in 2007 than in 2019, but species composition was similar between the surveys, and the co-occurrence of bird species was random. Even though the bird diversity was considered depauperated, it was comprised of a wide range of species classified as residents, migrants and waterbirds, indicating their ability to tolerate urbanisation. More studies are required to confirm that bird species are surviving and reproducing in this urban habitat.","PeriodicalId":332684,"journal":{"name":"Scientia Bruneiana","volume":"6 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138590012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Current Status of FMD and Detection of Foot and Mouth Disease in Goats using ELISA method in Brunei Darussalam","authors":"Kahrani Ishak, Pg Aimi Fadzilah Pg Hj Kamis","doi":"10.46537/scibru.v20i1.127","DOIUrl":"https://doi.org/10.46537/scibru.v20i1.127","url":null,"abstract":"Brunei Darussalam has been recognized as a free Foot and Mouth Disease country.  Nonetheless, control efforts must be done to maintain this status. A reliable and precise diagnostic test is needed for rapid detection which can make fast decision making by national authorities. This study is not only aim to update current status of FMD in the country but also to proof that the ELISA method used in Veterinary Laboratory Services of Brunei Darussalam is reliable and sufficient to detect presence of FMD. From data collection for the past 5 years, none of the blood serum collected from goat were detected with FMD which confirms that the country is free from FMD. The ELISA test conducted has been validated and accredited to ISO / IEC 17025:2017 since 2019 and has also participated in Proficiency Testing with satisfactory result which confirms that the test is sufficient to detect the presence of this disease. The method achieved 98% and 100% for Diagnostic Sensitivity and Diagnostic Specificity, with null false positive and only 1 false negative. The test also showed satisfactory in terms of repeatability, reproducibility and selectivity. With these satisfactory validation procedures, the country can use ELISA test method as one of the control efforts to prevent and control the spread of FMD if it happens.","PeriodicalId":332684,"journal":{"name":"Scientia Bruneiana","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128362039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new record of the fern Syngramma quinata in Brunei Darussalam","authors":"D. Cicuzza, T. Grafe, N. H. Zaini, M. Ruslan, S. Yu","doi":"10.46537/scibru.v19i2.128","DOIUrl":"https://doi.org/10.46537/scibru.v19i2.128","url":null,"abstract":"In this study, Syngramma quinata was newly recorded for Brunei Darussalam. The species is distributed from Peninsular Malaysia to Fiji but absent in Java and southwestern Indonesia. The record confirms the species’ preference for forest and its distribution close to streams and in shady habitats. While its distribution is frequent in the eastern part of the region (Papua and Solomon Islands), the species is rare in Borneo, Sumatra and Sulawesi. Therefore, this new record fills a gap in the distribution and ecology of this species.","PeriodicalId":332684,"journal":{"name":"Scientia Bruneiana","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124069752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reconnaissance geochemical and geophysical exploration for gold at Iri gold field, north central Nigeria","authors":"A. Aliyu, N. Waziri, H. L. Mohammad, MohammedSalih A. Mohammed, Apeh Aromeh Gideon","doi":"10.46537/scibru.v18i2.93","DOIUrl":"https://doi.org/10.46537/scibru.v18i2.93","url":null,"abstract":"Reconnaissance geochemical and geophysical exploration for gold was carried out at IRI Gold field. Geological mapping was conducted and rocks, soils and sediments samples were collected. The outcome revealed rocks of the basement complex of Nigeria made up of mainly, Migmatite Gneiss, Older Granite and the Schist. The major lithology in the area is silicified sheared rocks and large quartz vein. Isolated occurrence of undifferentiated schist was found as parent material on which quartzite intruded possibly during a major geological activity. Shattering of the rocks left boulders and rubbles of quartzite all around two major ridges within the study area. The rocks have shown weak geochemical anomaly except in two locations were positive anomalies were observed and identified as target for further exploration. Gold veins are prominent in the area suggesting potential gold mineralization. Interpretation of the aeromagnetic data give the orientations of the structural features, the major structural trend in the area is NE-SW. The lineaments extracted from the magnetic data range in length from 46.43m to about 1251.66m. Most of the lineaments extracted from the area are subsurface within the quartz-mica and migmatites while some of them have surface expressions even though not clearly defined. These magnetic lineaments could be the contacts between two rock types of contrasting magnetic   susceptibility   or   edges   of   structures   that   could   be faults or intrusive bodies. Interpreted satellite data show several subsurface structures which could be hosts to gold mineralization in the area. Results of the geochemical analysis of rocks, soils and sediments were super imposed on the interpreted aeromagnetic data and similar geochemical and geophysical signatures were established. \u0000  \u0000Index Terms: Gold mineralization, aeromagnetic data, geochemical data, schist belt, Nigeria","PeriodicalId":332684,"journal":{"name":"Scientia Bruneiana","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129044829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Amphibian species diversity in the proposed extension of the Bukit Teraja Protection Forest, Brunei Darussalam","authors":"Hanyrol H. Ahmad Sah, T. Grafe","doi":"10.46537/SCIBRU.V18I1.88","DOIUrl":"https://doi.org/10.46537/SCIBRU.V18I1.88","url":null,"abstract":"Amphibian species diversity was investigated within the lowland mixed-dipterocarp forest of the proposed extension of the Bukit Teraja Protection Forest (BTPF), Brunei Darussalam in north-west Borneo. A combination of both visual encounter and acoustic sampling techniques were conducted opportunistically as well as in six selected stream transects, each containing five 5x10m plots. A total of 39 species of frogs from seven families (Bufonidae, Ceratobatrachidae, Dicroglossidae, Megophryidae, Microhylidae, Ranidae, and Rhacophoridae) were identified from the BTPF. Most notably, four new records for Brunei were discovered: Hylarana nicobariensis, Kaloula baleata, Limnonectes malesianus, and Microhyla perparva. This brings the total number of amphibian species in Brunei Darussalam to 84. Canonical correspondence analysis showed that out of 13 measured environmental variables maximum stream depth and % soil/sand of ground cover were significantly correlated with anuran assemblage composition. Species overlap between the proposed extension of the Bukit Teraja Protection Forest and the Ulu Temburong National Park (UTNP) determined by the coefficient of biogeographic resemblance (CBR) showed low species complementarity between these two regions. This emphasizes the need to upgrade the proposed extension of the BTPF to a protection forest to ensure the conservation of regional amphibian biodiversity.","PeriodicalId":332684,"journal":{"name":"Scientia Bruneiana","volume":"338 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123129081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Acacia invasion on leaf litter nutrient and soil properties of coastal Kerangas forests in Brunei Darussalam","authors":"A. Yusoff, K. Tennakoon, S. Jaafar, Dk Nur Amal Nazira Pg Zaman, R. Sukri","doi":"10.46537/SCIBRU.V18I1.87","DOIUrl":"https://doi.org/10.46537/SCIBRU.V18I1.87","url":null,"abstract":"Exotic Acacia were introduced to Brunei Darussalam in the 1990s for plantation forestry and land rehabilitation but are now regarded as invasive. We assessed the effects of Acacia on litter nutrient composition and soil physicochemical properties of Brunei’s coastal Kerangas (heath) forests. Soil and litter samples were collected from ten 20 x 20 m plots in Acacia-invaded Kerangas forests (IKF) and ten uninvaded (UKF) plots. Soil samples were analyzed for pH, gravimetric water content and nutrient concentrations whereas litter samples were analyzed for total nutrients only. We recorded significantly higher concentrations of litter total N and P in the IKF than the UKF plots. In contrast, no significant differences were detected in soil properties, except for topsoil available P and subsoil exchangeable Ca which were both lower in the IKF plots. A significant positive correlation was detected between litter N and topsoil N in the IKF plots. We suggest that the fairly recent timescale of Acacia invasion (< 25 years) of the IKF sites resulted in the lack of significant increase of soil nutrients. In conclusion, Acacia invasion into Brunei’s forests can potentially alter both leaf litter and soil physicochemical properties of Kerangas forests, in particular affecting nutrient availability. This alteration of ecosystem may further enhance the invasion success of Acacia, making restoration attempts more challenging.","PeriodicalId":332684,"journal":{"name":"Scientia Bruneiana","volume":"111 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126882093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of a Reservoir Fluid Based on an Analysis of Intrinsic Properties Using the Adaptive Batzle-Wang Method in Field “M”","authors":"M. Rosid, Muhammad Iksan, Reza Wardhana, M. Haidar","doi":"10.46537/SCIBRU.V17I2.79","DOIUrl":"https://doi.org/10.46537/SCIBRU.V17I2.79","url":null,"abstract":"The physical properties and phases of a fluid under reservoir conditions are different from those under surface conditions. The value of a fluid property may change as a result of changes in pressure and temperature. An analysis of the intrinsic properties of fluids is carried out to obtain a fluid model that corresponds to fluid conditions in a reservoir. This study uses the Adaptive Batzle-Wang model, which combines thermodynamic relationships, empirical data trends, and experimental fluid data from the laboratory to estimate the effects of pressure and temperature on fluid properties. The Adaptive Batzle-Wang method is used because the usual Batzle-Wang method is less suitable for describing the physical properties of a fluid under the conditions in the field studied here. The Batzle-Wang fluid model therefore needs to be modified to obtain a fluid model that adjusts to the fluid conditions in each study area. In this paper, the Adaptive Batzle-Wang model is used to model three types of fluid i.e. oil, gas, and water. By making use of data on the intrinsic fluid properties such as the specific gravity of the gases (G), the Gas-Oil Ratio (GOR), the Oil FVF (Bo), the API values, the Salinity, and the Fluid Density obtained from laboratory experiments, the Batzle-Wang fluid model is converted into the Adaptive Batzle-Wang model by adding equations for the intrinsic fluid properties under the pressure and temperature conditions in the field reservoir. The results obtained are the values of the bulk modulus (K), the density (ρ), and the P-wave velocity (Vp) of the fluid under reservoir conditions. The correlation coefficient of the Adaptive Batzle-Wang model with the fluid data from the laboratory experiments is 0.95. The model is well able to calculate the fluid properties corresponding to the conditions in this field reservoir. The model also generates a unique value for the fluid properties in each study area. So, it can adjust to the pressure and temperature conditions of the field reservoir under study. The Adaptive Batzle-Wang method can therefore be applied to fields for which laboratory fluid data is available, especially fields with a high reservoir pressure and temperature. The results of the fluid modeling can then be used for rock physics and Fluid Replacement Model analysis.","PeriodicalId":332684,"journal":{"name":"Scientia Bruneiana","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129904603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From fruit waste to enzymes","authors":"Y. Y. Chin, Roemah Goeting, Yabit Alas, Pooja Shivanand","doi":"10.46537/SCIBRU.V17I2.75","DOIUrl":"https://doi.org/10.46537/SCIBRU.V17I2.75","url":null,"abstract":"Domestic and municipal solid wastes pose environmental concerns and health risks, suggesting the importance of reduced waste disposal. Food waste accounts for the highest percentage of solid waste in Brunei. An effective strategy is to convert food waste into beneficial products such as enzymes and biofertilizers. This study reports utilization of inedible fruit peels as substrates for enzyme production. A fermentation medium prepared by adding fruit peels, brown sugar and water was allowed to ferment over a period of time. Total carbohydrate content was found to be highest in the fermented orange sample (37.87 ± 4.7 mg/mL) followed by pineapple and banana samples, 11.98 ± 1.45 mg/mL and 10.60 ± 0.45 mg/mL, respectively. Pineapple sample showed the highest concentration of reducing sugar (11.93 mg/mL at week 2 and 3.31 mg/mL after 3 months). Enzyme assay showed that citrus fruits like oranges, yield high activities of enzymes like protease (0.129 U/mL), α-amylase (7.261 ± 0.83 U/mL) and cellulase (0.514 ± 0.03 U/mL). This fermentation product of kitchen waste is economical as it uses cheap raw materials, free of chemical additives and hence eco-friendly.","PeriodicalId":332684,"journal":{"name":"Scientia Bruneiana","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121131157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phytochemical characterization of essential oils from shoots, mature leaves and branchlets of Litsea elliptica (Lauraceae) collected in Brunei Darussalam","authors":"M. Pillai, Farazimah Yakop, Nurzaidah binti Metussin, M. H. S. Hamid, Hartini Yasin, Hj Mohamed bin Hj Abdul Majid, D. Young","doi":"10.46537/SCIBRU.V17I2.77","DOIUrl":"https://doi.org/10.46537/SCIBRU.V17I2.77","url":null,"abstract":"Essential oils from shoots, mature leaves and branchlets of Litsea elliptica were analyzed for their phytochemical compositions by GC-MS. A total of 12 compounds were identified from all three essential oils of L. elliptica.7-Decen-2-one (44.60%), 9-decen-2-ol (23.65%) and 2,7-octadienyl acetate (13.80%) were the major constituents of the essential oil from the shoots. p-Menthan-8-ol, (18.57%), 7-decen-2-one (10.62%), 9-decen-2-ol (25.09%) and α-terpineol (34.54%) were the major constituents of the essential oil from the mature leaves. Geranyl acetate (58.51%) and α-terpineol (20.95%) were the major constituents of the essential oil from the branchlets. L. elliptica has therapeutic applications in traditional medicine. Essential oils and/or extracts from various parts of this plant are reported to have promising biological and pharmacological activities.","PeriodicalId":332684,"journal":{"name":"Scientia Bruneiana","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114612055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of Rock Physics Models by Combining the Differential Effective Medium (DEM) and Adaptive Batzle-Wang Methods in “R” Field, East Java","authors":"M. Haidar, Reza Wardhana, M. Iskan, M. Rosid","doi":"10.46537/SCIBRU.V17I2.78","DOIUrl":"https://doi.org/10.46537/SCIBRU.V17I2.78","url":null,"abstract":"The pore systems in carbonate reservoirs are more complex than the pore systems in clastic rocks. There are three types of pores in carbonate rocks: interparticle pores, stiff pores and cracks. The complexity of the pore types can lead to changes in the P-wave velocity by up to 40%, and carbonate reservoir characterization becomes difficult when the S-wave velocity is estimated using the dominant interparticle pore type only. In addition, the geometry of the pores affects the permeability of the reservoir. Therefore, when modelling the elastic modulus of the rock it is important to take into account the complexity of the pore types in carbonate rocks. The Differential Effective Medium (DEM) is a method for modelling the elastic modulus of the rock that takes into account the heterogeneity in the types of pores in carbonate rocks by adding pore-type inclusions little by little into the host material until the required proportion of the material is reached. In addition, the model is optimized by calculating the bulk modulus of the fluid filler porous rock under reservoir conditions using the Adaptive Batzle-Wang method. Once a fluid model has been constructed under reservoir conditions, the model is entered as input for the P-wave velocity model, which is then used to estimate the velocity of the S-wave and the proportion of primary and secondary pore types in the rock. Changes in the characteristics of the P-wave which are sensitive to the presence of fluid lead to improvements in the accuracy of the P-wave model, so the estimated S-wave velocity and the calculated ratio of primary and secondary pores in the reservoir are more reliable.","PeriodicalId":332684,"journal":{"name":"Scientia Bruneiana","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129441839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}