A Survey of Heart Rot in Some Plantations of Acacia mangium Willd. In Sabah.

Only 4% of thinnings had heart rot which appeared to originate from thinning wounds. In the older trees, the average incidence of heart rot was 35.5%. -from Author

Bioassay of Some Forest Plantation Soil Fungi on Coptotermes curvignathus Holmgren (Isoptera: Rhinotermitidae)

Four isolates of soil fungi with different concentrations (1.0 x 106 conidia/ml, 1.0 x 107 conidia/ml, and 1.0 x 108 conidia/ml) were tested on Subterranean termites, Coptotermes curvignathus that colonized the stems of Acacia mangium stands in Sabah Softwood Berhad (SSB) and Sabah Forest Development Authority (SAFODA) in Sabah, Malaysia. Determination of LT50 found that Trichosporonoides sp. and Helicocephalum sp. recorded the earliest LT50 which is at Day-3 for concentration of 1.0 x 106 conidia/ml. Rhopalomyces sp. was the earliest for concentration of 1.0 x 107 conidia/ml which is at Day-2, whilst, Trichosporonoides sp. and Rhopalomyces sp. were the earliest for concentration of 1.0 x 108 conidia/ml which is at Day-2. LC50 indicated that only Rhopalomyces sp. was capable of causing 50% death at 1.0 x 107 conidia/ml. Extrapolation of curve for Helicocephalum sp., MSK B and Trichosporonoides sp. gave estimate for LC50 at concentration of 1.5 x 1011 conidia/ml, 6.3 x 1018 conidia/ml and 2.0 x 109 conidia/ml. All concentrations used (1.0 x 106, 1.0 x 107 and 1.0 x 108 conidia/ml) showed capability by fungi to caused mortality on C. curvignathus that differ significantly (t=4.508; df=270; P=0.000) between isolates and control. In this study, Trichosporonoides sp., Rhopalomyces sp., Helicocephalum sp. and MSK B have shown entomopathogenic activity against C. curvignathus. Accordingly, Trichosporonoides sp. and Rhopalomyces sp. have the potential based on their LT50 and LC50 to be used as effective biological control against C. curvignathus

Analysis of stone mastic asphalt (SMA) slab dimensions for evaluation of the newly developed roller compactor (Turamesin)

Stone Mastic Asphalt (SMA) is one type of asphalt mixture which is highly dependent on the method of compaction as compared to conventional Hot Mix Asphalt (HMA) mixture. A suitable laboratory compaction method which can closely simulate field compaction is evidently needed as future trend in asphalt pavement industry all over the world is gradually changing over to the SMA due to its excellent performance characteristics. This study was conducted to evaluate the SMA slab mixtures compacted using a newly developed Turamesin roller compactor, designed to cater for laboratory compaction in field simulation conditions. As the newly developed compaction device, there is a need for evaluating the compacted slab dimensions (which include length, width, and thickness), analyzing the consistency of the measured parameters to verify the homogeneity of the compacted slabs and determining the reliability of Turamesin. A total of 15 slabs from three different types of asphalt mixtures were compacted, measured, and analyzed for their consistencies in terms of length, width, and thickness. Based on study the conducted, the compacted slabs were found to have problems in terms of the improperly compacted section of about 30 mm length at both ends of the slabs and the differences in the thickness between left- and right-side of the slab which were due to unequal load distribution from the roller compactor. The results obtained from this study have led to the development of Turamesin as an improved laboratory compaction device

Fungal colonization and decay in tropical bamboo species

The development of fungal colonization and decay in the culms of a tropical bamboo Gigantochloa scortechinii, through ground contact tests in a tropical soil were described. Observations were made using Scanning Electron Microscopy (SEM). Both untreated and samples treated with either Borax-Boric Acid mixture (BBA) Ammoniacal Copper Quaternary (ACQ) ammonium compound or Copper-Chrome-arsenic (CCA) were investigated. Over 24-months of exposure, untreated and ineffectively treated culms exhibited extensive degradation and colonisation of all tissues (ground tissue parenchyma, fibers and vascular elements) by fungi. Fungal colonists were observed in the cell lumina, the degraded cell walls and in the intercellular spaces. The morphology of decay was a characteristic of degradation by white and soft rot fungi and occasionally, was accompanied by bacterial attack. In contrast, the tissues of culms that had received effective preservative treatments had restricted hyphal colonisation with infrequent hypal invasion into cell via pits; or without cell wall degradation

Chemical, Colour and Strength Changes of Eco-friendly Hot Oil Treatment on 15 Year-old Cultivated Acacia Hybrid

The chemical, colour and strength properties of thermally modified cultivated 15-year-old Acacia hybrid were investigated. Logs of A. hybrid were harvested and cut at the bottom, middle and top sections. The wood later underwent hot oilthermal modification using palm oil at temperatures 180°C, 200°C and 220°C for 30, 60 and 90 min. Untreated wood was used as control. The hot oil thermal modification process caused some features changed in the chemical composition, colour appearances and strength properties of A. hybrid wood. Parameters such as temperatures and treatment time were closely monitored as they influence the chemical, colour and strength changes in the treated wood. Temperatures of 180°C, 200°C and 220°C, and treatment time of 1 hr, 2 hrs. and 3 hrs. were used in the study. The degradation in holocellulose, cellulose, and hemicellulose contents was recognized when acacia woods were exposed to oil thermally modified process. Holocellulose and celulose degraded with the increasing of treatment temperature and duration of heating exposure, while lignin showed the increment in content through this treatment. The colour changes in the sapwood and heartwood were measured using the Minolta Chroma-meter CR-310 and the results are presented according to the CIE L*a*b* colour co-ordinates system. The results show that temperature at certain treatment time enhanced and darkened the treated wood. The colour of the treated sapwood can be enhanced to match the colour of the natural A. hybrid heartwood. The strength properties of the oil heat treated A. hybrid wood decreases in values of both MOR and MOE throughout thetreatment process. The decreases in values were influenced by temperature and duration of the treatment

Anatomical properties and microstructures features of four cultivated bamboo gigantochloa species

Anatomical properties and microstructure features of four (4) cultivated species of popular tropical bamboo genus Gigantochloa were studied. Gigantochloa brang, G. levis, G. scotechinii and G. wrayi of age-group 3 were selected, harvested and processed for the anatomical and microstructure studies. The studies focussed mainly on the vascular bundles and fiber cells located at the internodes and nodes 8 at the outer, middle and inner layers of the bamboo. The sizes of the vascular bundles length, vascular bundles width, fiber length, fiber diameter, fiber lumens diameter, fiber walls thickness and fiber Runkle’s ratio were measured between each of the species in relation to the samples positions at the internodes, nodes, and positions in the cross-section of the bamboo culms. The results in the fibers morphology studies showed that the fibers for each species has different lengths, diameters, cell walls thickness and lumen sizes. The size of vascular bundle is smaller at outer position and become bigger at the inner position. All the four (4) bamboo species exhibited similar in characteristics but having different sizes in anatomy and microstructure features

Chemical, colour and strength changes of hot oil treatment process on 15-year-old cultivated acacia hybrid

The chemical, color and strength properties of thermally modified cultivated 15-year-old Acacia hybrid were investigated. Logs of A. hybrid were harvested and cut at the bottom, middle and top sections. The wood later underwent hot oil thermal modification using palm oil at temperatures 180, 200 and 220ºC for 30,60 and 90 min. Untreated wood was used as control. The hot oil thermal modification process caused some features changed in the chemical composition, color appearances and strength properties of A. hybrid wood. Parameters such as temperatures and treatment time were closely monitored as they influence the chemical, color and strength changes in the treated wood. Temperatures of 180, 200 and 220ºC, and treatment time of 1,2 and 3 h. were used in the study. The degradation in holocellulose, cellulose, and hemicellulose contents was recognized when acacia woods were exposed to oil thermally modified process. Holocellulose and cellulose degraded with the increasing of treatment temperature and duration of heating exposure, while lignin showed the increment in content through this treatment. The color changes in the sapwood and heartwood were measured using the Minolta Chroma-meter CR-310 and the results are presented according to the CIE L* a*b* color co-ordinates system. The results show that temperature at certain treatment time enhanced and darkened the treated wood. The color of the treated sapwood can be enhanced to match the color of the natural. A hybrid heartwood. The strength properties of the oil heat treated A. hybrid wood decreases in values of both MOR and MOE throughout the treatment process. The decreases in values were influenced by temperature and duration of the treatmen

Sleep Deprivation and Study Habits Effects toward Medical Imaging Students, UiTM Puncak Alam

This study aimed to investigate the effects of sleep deprivation and study habits during online distance learning (ODL) among students. The objective of this study is to evaluate the relationship between sleep deprivation and study habits with academic performance among students during ODL. A cross-sectional survey is used through an online platform. The questionnaire was distributed to 191 students in Medical Imaging course. The data being analyzed using SPSS software version 26. Most students had poor sleep (n=130, 68.1%) and poor study habits (n=136, 71.2%). There is no significant correlation between sleep deprivation (X2=0.31, df=2, p=0.855) and study habits (X2=1.26, df=2, p=0.533) on student’s academic performance. Keywords: sleep deprivation; study habits; e-learning; academic performance eISSN: 2398-4287 © 2022. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open-access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under the responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians/Africans/Arabians), and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia. DOI: https://doi.org/10.21834/ebpj.v7i21.373

Strength and Durability of Bamboo Treated Through an Oil-curing Process

Investigations on the strength and performance of an oil-cured bamboo Gigantochloa scortechinii in a 12 months ground contact tests show that the bamboo experienced some reduction in their strength properties and greatly enhanced the durability against biodegradation agents. The MoE value in bending strength were reduced by 13 to 42% in green and 3 to 29% in air-dried condition. In the MoR modulus in the bending strength, the value were reduced by 10 to 35% in green and 2 to 31% in air-dried condition. The compression strength were reduced by 18 to 33% in green and 14 to 27% in air-dried condition. The shear strength were reduced in the ranged between 16 to 58% in green and 14 to 54% in air-dried samples. An overall decreased in weight loss also occurred of oil-cured samples after 12 months of ground contact tests. Green condition sample recorded a decreased in weight loss between 4 to 33% and 4 to 33% in air-dried samples. Control samples that are composed of untreated bamboo and rubberwood experienced weight loss of about 48 and 40%, respectively. An oil-cured bamboo performed much better compared to those of untreated in the ground contact tests. The weight loss in term of percentage after 12 months tests varies from 4 to 34% with samples oil-cured at higher temperature and longer duration losing less weight