ABSTRACT. The 17 Malaysian Scindapsus species were investigated numerically using morphological and anatomical characters. These data were used to establish interspecies relationships. Numerical analyses, using MVSP Plus Version 2.2 on the data matrix containing 37 characters, were employed concentrating on nearest neighbour cluster analysis and furthest neighbour cluster analysis. The analyses show three constant clustered groups: (1) Scindapsus beccarii and S. crassipes, (2) S.hederaceus, S. pictus, S. perakensis and S. longistipitatus and, (3) S. coriaceus, S. rupestris and S. borneensis. This study proposed S. havilandii be excluded from the genus Scindapsus.
ABSTRAK. Kajian ini bertujuan menentukan kepekatan logam berat iaitu Pb, Cd, Zn, Fe dan Cu di dalam Meretrix sp. dan sedimen di kawasan pesisir pantai Bongawan dan Lok Kawi, Sabah. Logam berat dianalisis menggunakan ICP-OES setelah tisu Meretrix sp. dan sedimen dihadamkan menggunakan larutan aqua regia (HNO3: HCl). Hasil analisis menunjukkan kepekatan Pb, Cd, Zn, Fe dan Cu dalam Meretrix sp. adalah masing-masing dalam julat 0.08 – 0.50 mgkg-1, < 0.01 - 0.05 mgkg-1, 5.46 – 12.0 mgkg-1, 78.54 – 237.45 mgkg-1 dan 0.45 – 1.2 mgkg-1 manakala dalam sedimen adalah masing-masing berjulat 0.25 – 2.95 mgkg-1, < 0.01 – 0.35 mgkg-1, 1.22 – 16.35 mgkg-1, 422.0 – 1028.95 mgkg-1 dan 0.13 – 1.90 mgkg-1. Analisis korelasi Pearson menunjukkan terdapatnya pengaruh kepekatan logam berat daripada sedimen dalam Meretrix sp. yang signifikan pada aras p < 0.01 khususnya bagi logam Pb, Cd dan Zn. Ini turut dibuktikan daripada nilai pengiraan faktor biokepekatan (BCF) di antara sedimen dan Meretrix sp. yang berada pada julat logam Pb (0.12 – 0.56), Cd (0.14 – 4.00), Zn (0.73 – 6.52), Fe (0.12 – 0.56) dan Cu (0.16 – 5.14) masing-masing. Secara keseluruhannya, kepekatan semua logam berat dalam Meretrix sp. tidak melebihi had yang ditetapkan dalam Akta Makanan 1983.
KATAKUNCI. Logam berat, ICP-OES, sedimen, aqua regia, Meretrix sp.
ABSTRACT. A comparative study of organic and conventional farming system at two planting fields was conducted in Sabah Tea Plantation to determine the effect of management practices on soil nitrogen and pH, as well as leaf size and major polyphenol and caffeine content. Soil and leaves samples were from two selected fields; B29 (conventional field) and NO3 (organic field) in Sabah Tea Plantation, and were analyzed using UV spectrophotometer and high performance liquid chromatography methods. Organic farming system resulted in significantly higher soil pH (4.14), leaf length (15.14 cm), leaf width (7.33 cm) as well as major polyphenol content in tea shoot (172.42 mg/g) as compared to conventional farming system with soil pH (3.38), leaf length (13.19 cm), leaf width (5.58 cm) and major polyphenol content in tea shoot (107.03 mg/g). On the other hand, conventional farming system produced higher levels of ammonium (332.4 kg/ha) and nitrate (39.0 kg/ha) content in soil as compared to organic farming system (45.2 and 19.2 kg/ha, respectively). No significant difference in caffeine, epicatechin, epicatechin gallate and epigallocatechin content in leaves was observed between the two farming systems. The study provides some basic knowledge on soil nitrogen and pH level as well as tea major polyphenol and caffeine content in tea shoot of organic and conventional farming in Sabah Tea Plantation.
KEYWORDS. Caffeine, Conventional, Nitrogen, Organic, Polyphenol
ABSTRACT.This paper presentsthe atomistic scale study of the effects of local heating during nanoindentation into Silicon (Si). Nanoindentation techniques and experiments with fundamental principles of MD simulations were at first introduced.The indentation processesof indentation depths an order of magnitude much smaller than experimental values and over indentation times several orders of magnitude shorter. The effects of local heating were studied using Force-Depths (F-D) curves and snapshots. The influences of the indentation speeds and temperature on the deformative behaviour of Silicon (Si) were also discussed. The force-depth curves signified the temperature influence on silicon during retraction for thermalized speeds, implying that the topology of the silicon surface did not change after tip retraction. Snapshots of the simulations into Si showed that slower indentation speeds would exhibit a decrease in the number of heated atoms.
KEYWORDS. Nanoindentation, indentation depths, indentation speeds, thermalized,simulations.
ABSTRACT. This paper describes the importance of geological engineering inputs to landslide hazard occurrences in the Trusmadi Formation slopes, Sabah, Malaysia. The Trusmadi Formation regionally consists of two major structural orientations NW-SE and NE-SW. It consists mostly of dark grey shale with thin bedded sandstone, typical of a turbidite deposit. This unit has been subjected to low grade metamorphism, producing slate, phyllite and meta-sediment as well as intense tectonic deformation producing disrupted or brecciated beds. Quartz veins are quite widespread within the joints on sandstone beds. The shale is dark grey when fresh but changes to light grey and brown when weathered. The weathered materials are unstable and may experience sliding due to high pore water pressure, steep, hummocky or rugged slopes and intensively geomorphologic processes. Engineering properties of fifty five (55) soil samples indicated that the failure materials mainly consist of poorly graded materials of silty clay soils and and are characterized by low to intermediate plasticity content (12 % to 23 %), containing inactive to normal clay (0.43 to 1.47), very high to medium swelling (7.98 to 9.28), low to high water content (5 % to 25 %), specific gravity from 2.61 to 2.69, low permeability (8.78 X 10-3 to 3.28 X 10-3 cm/s), friction angle ()from 7.72˚ to 26.65˚ and cohesion (C) from 5.11 KPa to 15.34 KPa. The rock properties of twenty five (25) samples indicated that the point load strength index and the uniaxial compressive strength range were moderately weak. The geological influence had transformed the Trusmadi Formation slopes to be highly unstable and susceptible to landslide occurrences. Six (6) related main parameters were attributed: 1) local and regional geology, 2) hydrological and geohydrological, 3) mineralogical and micro structures, 4) local discontinuities structures, 5) physical and engineering properties of soil and rock, and 6) geomorphological processes which can help in evaluating landslide problems in Trusmadi Formation slopes. In conclusion, the geological factor evaluation should be prioritised and take into consideration in the initial step in all infrastructure programmes and may play a vital role in landslide hazard and risk assessment to ensure public safety.
KEYWORDS. Geological Factors, Landslide Hazard Identification (LHI), Trusmadi Formation