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11.
Bazil Taha?AhmedEmail author Miguel Calvo?Ramón Leandro?De?Haro Ariet 《Wireless Personal Communications》2004,31(1-2):19-31
The uplink capacity and the interference statistics (mean and variance) of the sectors of the cigar-shaped W-CDMA microcell are studied. A model with eighteen sectors is used to analyze the uplink. The microcells are assumed to exist in a long tunnel with at least nine base stations. The hybrid model of propagation is used in the calculations. The capacity and the interference statistics of the sectors are studied in terms of the most important parameters: sector radius, specific attenuation factor, antenna sidelobe levels, bend losses and the power control standard deviation error. 相似文献
12.
Bazil Taha-Ahmed Miguel Calvo-Ramón Leandro Haro-Ariet 《Wireless Personal Communications》2007,43(2):355-367
In this paper, we present an analytical model to quantify the effect of the Ultra-Wide Band (UWB) transmitters on the CDMA-PCS
downlink range and normalized capacity. The effect is given for different configuration and environments. Our analysis shows
that, for a single UWB transmitter, an UWB power density of −78dBm/MHz is the maximum permitted power density to have only
PCS macrocell capacity reduction of 1% when the distance between the PCS mobile and the UWB transmitter is 1 m. For the multiple
UWB transmitters case, a power density of −80dBm/MHz, is the maximum permitted power density to have only PCS macrocell capacity
reduction of 1% when the distance between the PCS mobile and the UWB transmitter is 1 m. 相似文献
13.
Mohd Basyaruddin Abdul Rahman Noraini Abdul Ghani Nik Ghazali Nik Salleh Mahiran Basri Raja Noor Zaliha Abdul Rahman Abu Bakar Salleh 《Journal of Coatings Technology and Research》2011,8(2):229-236
Of late, UV-curable products are gaining attention in the wood industry because of the effectiveness and efficiency of this
method. UV-curable surface coatings are widely used because of their excellent properties and because they are environmentally
friendly products. In this study, immobilized Candida antarctica lipase B was used to catalyze formation of liquid wax esters, such as adipate esters, via a solvent-free process. The adipate
esters formed were then used as UV-curable reactants in the wood coating formulations, consisting of epoxy acrylate, additives,
and a photoinitiator. The performance of the products was evaluated by coating them onto glass tiles (using gel content, hardness,
and scratch resistance tests) and wood panels (using adhesion, impact, and heat resistance tests). The coated film from this
formulation performed well during the evaluation tests. The gel content exhibited more than 90% polymerization, while the
pendulum hardness gave a value of 55.25%. Both analyses were significant in determining the effect of irradiation cycles.
A scratch test was also carried out to verify the resistance of the coating. The maximum weight load which can be resisted
by the wax esters formulation is 4.5 N. 相似文献
14.
Syafinaz Zainol Mahiran Basri Hamidon Bin Basri Ahmad Fuad Shamsuddin Siti Salwa Abdul-Gani Roghayeh Abedi Karjiban Emilia Abdul-Malek 《International journal of molecular sciences》2012,13(10):13049-13064
Response surface methodology (RSM) was utilized to investigate the influence of the main emulsion composition; mixture of palm and medium-chain triglyceride (MCT) oil (6%–12% w/w), lecithin (1%–3% w/w), and Cremophor EL (0.5%–1.5% w/w) as well as the preparation method; addition rate (2–20 mL/min), on the physicochemical properties of palm-based nanoemulsions. The response variables were the three main emulsion properties; particle size, zeta potential and polydispersity index. Optimization of the four independent variables was carried out to obtain an optimum level palm-based nanoemulsion with desirable characteristics. The response surface analysis showed that the variation in the three responses could be depicted as a quadratic function of the main composition of the emulsion and the preparation method. The experimental data could be fitted sufficiently well into a second-order polynomial model. The optimized formulation was stable for six months at 4 °C. 相似文献
15.
Izuddin Abdul Rahman Raja Noor Zaliha Raja Abdul Rahman Abu Bakar Salleh Mahiran Basri 《Journal of surfactants and detergents》2013,16(3):427-434
The use of enzymes in detergent formulations is becoming popular due to the concerns about the environment. T1 lipase (E.C. 3.1.1.3) was evaluated for its stability and performance in dishwashing along with other common components of an automatic dishwashing detergent. Therefore, the process of formulating the detergent would depend on the stability of T1 lipase, which may also reflect the performance during the washing. T1 lipase was mostly stable in nonionic surfactants, especially those that were made of polyhydric alcohols. T1 lipase was also stable in a mixture of sodium carbonate and glycine. However, sodium carbonate alone destabilized T1 lipase possibly due to the interaction between carbonates and Ca2+. These results indicated that polyhydric alcohols and glycine had stabilizing effects on T1 lipase. The dishwashing performance was evaluated in term of percent soil removed. The dishwashing performance of the formulated detergent was positively affected by the increase in temperature but negatively affected by the presence of hard water, specifically Ca2+ and Mg2+. However, T1 lipase was not negatively affected by the presence of hard water, and this enzyme was enhanced by the presence of polyacrylates. The presence of Ca2+ improved the structural integrity of T1 lipase. It is generally known that most enzymes that depend on Ca2+ for their structural integrity would be greatly destabilized in the presence of metal chelators; thus, stabilizing strategies such as adding glycine would be essential to maintain enzyme activity during the wash. 相似文献
16.
Salina Mat Radzi Mahiran Basri Abu Bakar Salleh Arbakariya Ariff Rosfarizan Mohammad Mohammad Basyaruddin Abdul Rahman Raja Noor Zaliha Raja Abdul Rahman 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2006,81(3):374-380
An optimisation study of the large‐scale enzymatic synthesis of a liquid wax ester from oleic acid and oleyl alcohol using Novozym 435 was carried out. Investigations were performed in batch mode with a stirred tank reactor (STR) with one multi‐bladed impeller. Response surface methodology (RSM) based on a five‐level, three‐variable central composite rotatable design (CCRD) was used to evaluate the interactive effects of various parameters. The parameters are amount of enzyme (A) (90–120 g), impeller speed (B) (100–400 rpm) and temperature (C) (40–60 °C). The optimum conditions derived via RSM at a fixed reaction time of 1 h were successfully optimised as A = 104 g, B = 388.0 rpm and C = 49.7 °C. The actual experimental yield was 96.7% under the optimum conditions, which compared well with the maximum predicted value of 97.6%. Copyright © 2005 Society of Chemical Industry 相似文献
17.
Bazil Taha Ahmed Miguel Calvo Ramón Leandro De Haro Ariet 《Wireless Personal Communications》2004,31(1):19-31
The uplink capacity and the interference statistics (mean and variance) of the sectors of the cigar-shaped W-CDMA microcell are studied. A model with eighteen sectors is used to analyze the uplink. The microcells are assumed to exist in a long tunnel with at least nine base stations. The hybrid model of propagation is used in the calculations. The capacity and the interference statistics of the sectors are studied in terms of the most important parameters: sector radius, specific attenuation factor, antenna sidelobe levels, bend losses and the power control standard deviation error. 相似文献
18.
The capacity and the interference statistics (mean value and variance) of the sectors of the cigar-shaped Wideband Code Division
Multiple Access microcells are studied. The two-slope propagation model is used in the analysis. A model of five microcells
is used to calculate the uplink capacity and interference statistics assuming highways cigar-shaped microcells. The capacity
and the interference statistics of the microcell are studied for different sector range, propagation exponent, antenna side
lobe levels and different standard deviation of the power control error. It is noticed that the quasi-maximum uplink sector
capacity can be got when the sector range R is between 600 and 1,200 m and the sidelobe level of the directive antenna used
in each sector is on the order of −15 dB. 相似文献
19.
20.
Akselrod-Ballin A. Galun M. Gomori J.M. Filippi M. Valsasina P. Basri R. Brandt A. 《IEEE transactions on bio-medical engineering》2009,56(10):2461-2469
We introduce a multiscale approach that combines segmentation with classification to detect abnormal brain structures in medical imagery, and demonstrate its utility in automatically detecting multiple sclerosis (MS) lesions in 3-D multichannel magnetic resonance (MR) images. Our method uses segmentation to obtain a hierarchical decomposition of a multichannel, anisotropic MR scans. It then produces a rich set of features describing the segments in terms of intensity, shape, location, neighborhood relations, and anatomical context. These features are then fed into a decision forest classifier, trained with data labeled by experts, enabling the detection of lesions at all scales. Unlike common approaches that use voxel-by-voxel analysis, our system can utilize regional properties that are often important for characterizing abnormal brain structures. We provide experiments on two types of real MR images: a multichannel proton-density-, T2-, and T1-weighted dataset of 25 MS patients and a single-channel fluid attenuated inversion recovery (FLAIR) dataset of 16 MS patients. Comparing our results with lesion delineation by a human expert and with previously extensively validated results shows the promise of the approach. 相似文献