Preparation and characterization of magnetite (Fe3O4) nanoparticles By Sol-Gel method

The magnetite (Fe3O4) nanoparticles were successfully synthesized and annealed under vacuum at different temperature. The Fe3O4 nanoparticles prepared via sol-gel assisted method and annealed at 200-400ºC were characterized by Fourier Transformation Infrared Spectroscopy (FTIR), X-ray Diffraction spectra (XRD), Field Emission Scanning Electron Microscope (FESEM) and Atomic Force Microscopy (AFM). The XRD result indicate the presence of Fe3O4 nanoparticles, and the Scherer`s Formula calculated the mean particles size in range of 2-25 nm. The FESEM result shows that the morphologies of the particles annealed at 400ºC are more spherical and partially agglomerated, while the EDS result indicates the presence of Fe3O4 by showing Fe-O group of elements. AFM analyzed the 3D and roughness of the sample; the Fe3O4 nanoparticles have a minimum diameter of 79.04 nm, which is in agreement with FESEM result. In many cases, the synthesis of Fe3O4 nanoparticles using FeCl3 and FeCl2 has not been achieved, according to some literatures, but this research was able to obtained Fe3O4 nanoparticles base on the characterization results

Reclassifying forest type to a new forest class based on vegetation and lithology characteristics using geographic information system at southern Johore, Malaysia

Recently forest resources management with regard to precision forestry concept has been highlighted by forest managers, in order to fulfill the demand on quality and reliable information about forest area. According to the Malaysian National Forestry Act 1984, forest is classified into several types by general classification which is based on vegetation types broadly into dipterocarp forest, peat swamp forest and mangrove forest. In applying precision forestry approach, details classification and information are required to render more accurate about managed forest. Therefore, this study was carried out to reclassify forest type to a new forest class based on vegetation and lithology characteristic using GIS technique. Ten new classes were successfully generated and mapped by fusing layer of forest vegetation types and lithology layer in Southern Johore, namely Dipterocarp-Igneous, Dipterocarp-Sediment, Dipterocarp-Alluvial, Peat-Igneous, Peat-Sediment, Peat-Alluvial, Mangrove-Igneous, Mangrove-Sediment, Mangrove-Alluvial and Limestone forest. In this study, Syzygium spp. (19.83 %) was found in abundance in two new forest classes; Dipterocarp-Igneous and Dipterocarp-Sediment forest in Hulu Sedili Permanent Forest Reserve (PFR). Beside that, Elateriospermum tapos (9.92 %) and family of Lauraceae (7.22 %) were found to be the most dominant species in the Dipterocarp-Sediment forest, while Macaranga spp. (11.21 %) and Elateriospermum tapos (11.02 %) found dominant in Dipterocarp-Igneous forest. From the sample plot, Dipterocarpaceae family constituted only 3.09 % whereas the non-Dipterocarpaceae family was 96.91 %. Hence, this study indicated that there is variation in species dominancy at different lithology of the same forest vegetation site

Mangrove mapping using Landsat imagery and aerial photographs: Kemaman District, Terengganu, Malaysia

Classification and distribution of mangrove vegetation are vital information for the proper development of a mangrove management plan. In this study, classification for the mangroves of the district of Kemaman were done using both 1 : 5000 aerial photographs and Landsat TM imageries. The coverage by aerial photographs is limited to the coastal and estuarine areas only. Thus, for areas further upstream of the aerial photo coverage, Landsat TM imageries were used. Analysis of aerial photographs and remote sensing images revealed that the mangroves of Kemaman could be classified into 14 different classes of vegetation. All the 14 classes were identified from areas covered by the aerial photographs. For areas covered by the Landsat images only 7 classes of vegetation were identified. The accuracy for aerial photograph and Landsat images are 91.2% and 87.8%, respectively. It can be concluded that although both techniques are useful in determining the mangrove vegetation classes, the large 1 : 5000 aerial photographs are more accurate and provided more detailed information comparatively

Rice Yield Estimation Using Below Cloud Remote Sensing Images Acquired by Unmanned Airborne Vehicle System

A method using unmanned airborne vehicle system (UAVS) and image processing technique to enable estimation of rice yield was developed. A digital Tetracam camera was mounted on a CropCam unmanned airborne vehicle (UAV) to acquire red (R), green (G) and near infrared (NIR) images of rice crops at the height of 300 m above ground.  NIR and R values were used to calculate normalised difference vegetation index (NDVI) value. Relationships between yield versus R, G, NIR and NDVI values were analysed. Results showed that the highest relationship was found in NDVI followed by R, G and NIR with coefficient of determination (r2) values of 0.748, 0.727, 0.395 and 0.014 respectively. Therefore, a yield estimation model using NDVI value was developed from the linear regression analysis. The results showed that the model was capable of estimating rice yield with an average accuracy value of 80.3%

THE INFLUENCES OF JOB PERFORMANCE, WORK-LIFE BALANCE AND ORGANIZATIONAL JUSTICE ON EMPLOYEES’ CAREER SATISFACTION

Purpose of study: This study is conducted to identify the relationships between job performance, work-life balance and organizational justice towards employee's career satisfaction from one of the manufacturing companies in the north of Malaysia. Methodology: The study is done by utilizing a random sample of 240 employees in the company. Type of investigation is a correlation study and it is cross-sectional on time horizon. The unit of analysis is an individual level; therefore, all employees in the company have chances to serve as the participants in this study. Data has been analysed from 148 respondents. Results: Results show significant and positive relationships between job performance, work-life balance and organizational justice towards employees' career satisfaction. Organizational justice is the most significant factor in career satisfaction in this study (β=.83, p=.00). Other factors such as job performance (β=.71, p=.00), and work-life balance (β=.71, p=.00) also positively correlated with employees’ career satisfaction. Implications/Applications: These significant results imply that managers should provide good elements of justice in the company to raise the level of their employee's career satisfaction. At the same time, the employees should maintain a higher level of job performance as well as to manage the good working life balance in them

Occurrence of Pedunculate Barnacle, Octolasmis Spp. in Blue Swimming Crab, Portunus Pelagicus [Tingkat Kejadian Pedunculate Barnacle, Octolasmis Spp. Pada Rajungan, Portunus Pelagicus]

Barnacle (teritip) adalah simbion yang dalam jumlah besar akan membahayakan kepiting. Teritip tersebut berpengaruh pada pernapasan, aktivitas normal dan pertumbuhan kepiting. Prevalensi, intensitas rata-rata dan identifikasi pedunculate barnacle, Octolasmis spp. pada rajungan, Portunus pelagicus dari daerah pesisir Kuala Terengganu telah diteliti. Kekhasan lokasi dari berbagai spesies Octolasmis telah diperiksa. Kepiting telah diukur dan ditimbang. Kepiting dieuthanasi dengan cara dimasukkan kedalam es sampai tidak bergerak. Octolasmis diamati dari permukaan tubuh dan insang (branchial chamber). Octolasmis diamati pada tiap insang. Prevalensi dan intensitas rata-rata dihitung. Octolasmis diawetkan dalam alcohol 70 % dan mounting menggunakan Jeli gliserin untuk membuat slide permanen. Semua kepiting 13 ekor telah terinfestasi oleh empat spesies Octolasmis, yaitu 218 Octolasmis angulata, 191 Octolasmis warwickii, 16 Octolasmis tridens dan 218 Octolasmis lowei. Octolasmis angulate menunjukkan prevalensi paling tinggi (84,62%) dan prevalensi paling rendah adalah O. lowei (23,08%) dan O. warwickii(23,08%). Teritip menyerang insang, karapas, abdomen dan juga kaki jalan.Teritip paling sering ditemukan pada bagian insang 371 ekor (57,70%) dibandingkan pada bagian lain, 272 ekor (42,30%). Distribusi teritip pada penelitian ini menunjukkan bahwa bagian distal lebih rentan mengalami infestasi Octolasmis spp. Namun, teritip tidak menunjukkan kekhasan lokasi pada daerah insang bergantung pada arus air

Assessing Cross anisotropy of Small-Strain Stiffness Using the Resonant Column apparatus

Almost all soils exhibit cross-anisotropic stiffness to some extent. However, measuring the cross anisotropic properties of soils is difficult because of the need to determine the 3 independent stiffness parameters Eν, Eh, Gνh, and the associated Poisson’s ratios, nνh and nhh. Current techniques that are employed, for example using bender elements or field geophysics, are not always reliable, whilst preparing specimens in different orientations and subsequent testing using standard laboratory techniques has practical constraints. The resonant column is a laboratory apparatus that has been extensively used to measure the torsional stiffness (Gνh). Relatively recent development has also allowed the Stokoe resonant column to measure Young’s modulus from flexural excitation of the specimen. The apparatus has also been used to determine Eν through axial oscillation. Thus a modified resonant column apparatus can apply four different excitations (flexure in two directions, torsion and longitudinal excitation) to a soil. This paper reports a series of dynamic finite element numerical simulations of physical tests in the resonant column apparatus, carried out to model both the apparatus and a cross-anisotropic soil specimen. Forward modelling has been carried out to determine the impact of different degrees of anisotropy on the resonant frequencies of ‘specimens’ with their axes of anisotropy aligned in different directions relative to the vertical axis of the apparatus. Methods of determining the elastic parameters from these data are assessed

Energy-absorption buildup factors and specific absorbed fractions of energy for bioactive glasses

In the present work, effective atomic numbers Zeff, energy-absorption buildup factors EABF and specific absorbed fractions of energy (Φ) for different bioactive glasses have been calculated in the present work. Geometric-Progression (G-P) fitting method was used for computation of EABF. The computed EABF is used to estimate the values of Φ. It is shown that the EABF and Φ are dependent on Zeff and mean free path. In addition, EABF and Φ were the largest for S4 and S7.The results in this work could be useful in choosing a suitable type of these glasses which in turn are able to resist possible radiation damages at human body and to determine the thickness and shape of the bioactive glasses needed

Penggunaan Metode Semiempirik AM1 Untuk Pemilihan Monomer Fungsional Efektif Pada Prasintesis Polimer Tercetak Diazinon

Pemilihan monomer fungsional yang efektif untuk sintesis Molecular Imprinted Polymer (MIP)untuk diazinon dapat dilakukan dengan pendekatan kimia komputasi dengan menerapkan metode semiempirik AM1. Proses seleksi menggunakan parametermomen dipol, energi interaksi, dan ikatan hidrogen yang terbentuk. Energi interaksi yang optimum menunjukkan kompleks yang terbentuk stabildan mengindikasikan MIP akan dapat terbentuk baik.Semua perhitungan pada penelitian ini dilakukan dengan menggunakan software Hyperchem 7.5. Hasil penelitian menunjukkan monomer fungsional efektif untuk prasintesis polimer tercetak diazinon yaitu akrilamida, asam akrilat, asam metakrilat, hidroksi etil metakrilat, asam urokanat, asam itakonat, dan asam urokanat etil ester. Hasil ini secara teoritik dapat memberikan informasi mengenai monomer fungsional efektif yang dapat digunakan sebagai pertimbangan sintesis MIP untuk diazinon dengan selektivitas relatif baik

Directional felling within selective management system of Peninsular Malaysia: comparison between current and extended techniques

Directional felling has been implemented in Peninsular Malaysia as part of the Selective Management System (SMS) to obtain optimum yield from the forest resources while reducing damage to the environment and residual trees. Some questions regarding its effectiveness have been questioned a few times, resulting in a joint research project at Ulu Jelai Forest Reserve, Pahang, Malaysia to compare between the current directional felling technique and the new (extended) techniques, in terms of accuracy of tree felling, volume of felling logs, expected damage on residual trees, and time taken for tree felling. For this study, 38 trees were felled with the current and extended techniques. By using the extended technique, 91.3% of the trees were felled within the 0°-5° range, and 100% within the 0°-10° range, compared to 28.01% (within the 0°-5° range) using the current technique. The extended technique also recorded higher volume recovery (14% higher) and lower damage on the residual trees by almost 50%. However, the extended technique took longer time, i.e. 4.56 minutes per tree, as compared to 2.50 minutes. The main contributor to the difference is the presence of gauge cut in the extended technique. Generally, the studies suggest that the extended technique is preferred as it is safer to the feller and surrounding people, while reducing the collateral damage on the harvested trees, as well as the residual trees