In this study, a novel matrix method based on collocation points is proposed to solve some linear and nonlinear integro-differential equations with variable coefficients under the mixed conditions. The solutions are obtained by means of Dickson and Taylor polynomials. The presented method transforms the equation and its conditions into matrix equations which comply with a system of linear algebraic equations with unknown Dickson coefficients, via collocation points in a finite interval. While solving the matrix equation, the Dickson coefficients and the polynomial approximation are obtained. Besides, the residual error analysis for our method is presented and illustrative examples are given to demonstrate the validity and applicability of the method.
A novel rapid ion colorimetric sensing material for iron(III) ions was developed from poly(γ-glutamic acid) and 3,4-dihydro-3-(2′-ethyl hydroxyl)-6-ethyl-1,3,2H-benzoxazine (ethyl-Bx). The benzoxazine as an ionophore segment was grafted into γ-PGA backbone via the esterification reaction, which is a simple and effective reaction. The structure of γ-PGA-graft-ethyl-Bx was characterized by using FT-IR and 1H-NMR. The most attainable degree of conversion was 25%. The γ-PGA-graft-ethyl-Bx showed a highly selective and sensitive recognition toward iron(III), which was clearly observable with the naked eye. The iron(III) ions sensing property of γ-PGA-graft-ethyl-Bx was further examined by using photometric titration method. After the interaction between the γ-PGA-graft-ethyl-Bx and iron(III) ions was formed, the solution of the polymer in dimethyl sulfoxide was changed from clear and colorless to red color, resulting in the shift of the maximum wavelength from UV to visible range.
This paper proposed an efficient modification of homotopy perturbation transform method (HPTM), namely modified homotopy perturbation transform method (MHPTM) for the solution of third order boundary layer equation on semi-infinite domain. The technique was based on the application of Laplace transform to boundary layers in fluid mechanics. The nonlinear terms can be easily handled by the use of He’s polynomials. The Pade´ approximants, that often show superior performance over series approximations, were effectively used in the analysis to capture the essential behavior of the boundary layer equation on infinity. We then conduct a comparative study between the MHPTM and the existing results with the help of third order boundary layer equation. The results obtained indicated that the MHPTM was effective and promising.
A novel bimetallic double thiocyanate-bridged ruthenium and tungsten metal complex containing bipyridyl and dithiolene co-ligands was synthesized and the behavior of the complex as a dye-sensitizer for a photoelectrochemical (PEG) cell for a direct water splitting reaction was investigated. The ligands and metal complexes were characterized on the basis of elemental analysis as well as uv-Vis, Fourier transform infrared ( Pim) and nuclear magnetic resonance (11I and 13C NMR) spectroscopy. Cyclic voltammetry of the bimetallic complex showed multiple redox couples, in which half potentials E 112 at 0 .625 , 0.05 and 0.61 V were assigned as the formal redox processes of Ru(III)IRu(II) reduction, W(IV)IW(V) and W(V)IW(VI) oxidations, respectively. Photocurrent measurements were performed in homogeneous system and TiO2 was used as the photoanode for photocurrent measurements. Current density generated by the bimetallic complex was higher than that of N3 commercial dye which suggested that the bimetallic complex donated more electrons to the semiconductor.
A novel silver nanoparticles (Ag NPs)-based optical sensing probe has been developed for the detection of Japanese Encephalitis virus (JEV). Ag NPs were initially deposited onto amine functionalized glass slides. Subsequently, JEV antibodies were self-assembled onto surfaces of Ag NPs to form optical sensing probes. The detection of JEV antigen was observed via changes in light absorbance by Ag NPs upon occurrence of JEV antigen-antibody bindings. A highly sensitive and rapid optical sensing probe for JEV antigen with a detection limit of 12.8 ng/mL (for S/N ratio = 3) and an analysis assay time of 1 h had been demonstrated.
The primary source of water on many small islands is the fragile freshwater lens that floats on saline water in its shallow aquifer. The management of such a limited groundwater resource on these islands is seriously constrained by the occurrence of seawater intrusion. Sipadan Island, the renowned and only oceanic island in Malaysia, had experienced in the over-extraction of its groundwater for more than ten years to cater for freshwater demand associated with tourism activities. This paper discusses the output of modelling of seawater intrusion into the island’s aquifer using SEAWAT-2000. The findings indicated that the island’s coastal aquifer has been encroached by seawater. The infiltration of isochlor (chloride concentration) of 2.5 and 45% of seawater and freshwater mixing ratios has moved 63.4 m and 12.7 m inland from the coastline, respectively. The upconing event at the pumping well, as simulated by the three-dimensional model, showed that 14.5% of seawater-freshwater mixing ratio took place below the bottom of each well. Intensive and unregulated exploitation of groundwater from such an unconfined aquifer of the island by pumping wells contributed to the upconing. In order to protect the fresh groundwater resources in the study area from seawater intrusion, adjustment of groundwater pumping rate is needed. This study showed that the model is useful in demonstrating the mechanism and movement of freshwater-seawater interface in the island, and thus provide a powerful management tool for such an aquifer.
A distinct element approach has been introduced for simulating the plugging performance of granular lost circulation materials (LCM) in a fracture. This approach solves the fully coupled fracture walls, fluid and particles system in an interactive environment. The effects of the particle shape, size distribution and concentration on the fracture-plugging performance of the granular LCM have been investigated using the three-dimensional particle flow code (PFC3D). The simulated results showed that the irregular granular LCM could plug a fracture width larger than the sieving granulation by single-particle bridging type. The particle size distribution (PSD) of LCM dominates the plugging depth and efficiency in a fracture and there exists an optimum concentration for maximum effect of LCM additives.
Pollen morphology of 24 species of Vatica L. had been investigated using light and scanning electron microscopes. Vatica is a stenopalynous genus, the pollens are radially symmetrical, isopolar, subprolate to suboblate sometimes prolate rarely oblate, all tricolpate. Exine ornamentation varies from thin to medium reticulate. On the basis of pollen shape two groups of Vatica have been recognized. Within the genus pollen diversity is valuable for identification and delimiting species.
A phytosociological study on the flora and vegetation community of Palaquium gutta (Hook.f.) Baill. was carried out in
Compartment 13 of Ayer Hitam Forest Reserve, Selangor. The main objectives of this study were to identify, characterize
and classify the P. gutta community which is naturally distributed in Ayer Hitam Forest Reserve. A total of 10 plots (30×30
m in size) were constructed according to the line transect method. The vegetation sampling and data analysis were done
according to the Braun-Blanquet approach. The results showed that there were 59 species belonging to 54 genera and 34
families in the form of herbs, shrubs, understorey trees and also canopy tree layers. The most common species in the study
area were P. gutta and Endospermum diadenum (Miq.) Airy Shaw. The phytosociological study identified a community
of Palaquium gutta-Endospermum. diadenum along with two sub-communities known as Dracaena sp. sub-community
and Streblus elongatus sub-community. The results also showed that most of the species belong to the Euphorbiaceae.
This indicates that the forest is a secondary forest.
The Malaysian Department of Environment-Water Quality Index (DOE-WQI) was determined for the Terengganu River basin which is located at the coastal water of the southern South China Sea between July and October 2008. Monthly samplings were carried out at ten sampling stations within the basin. Six parameters listed in DOE-WQI were measured based on standard methods: pH, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS) and ammonical nitrogen (AN). The results indicated the impact of various anthropogenic activities which contribute to high values of BOD, COD, TSS and AN at middle and downstream stations, as compared with the upstream of the basin. The reverses were true for the pH and DO values. The DOE-WQI ranged from 71.5-94.6% (mean 86.9%), which corresponded to a classification status range from slightly polluted to clean. With respect to the Malaysia National Water Quality Standards (NWQS), the level of most of the parameters measured remained at Class I which is suitable for the sustainable conservation of the natural environment, for water supply without treatment and as well as for very sensitive aquatic species. It is suggested that monitoring should be carried out continuously for proper management of this river basin.
Solanum nigrum L. is a species highly valued for its medicinal properties. In the present study, an efficient propagation system was established by using five explants of S. nigrum namely, roots, leaves, rooted hypocotyls, nodal segments and petioles. Various types of plant growth regulators (PGRs) were used to determine the most effective hormone combination for callus induction and organogenesis. Zeatin (ZT), thidiazuron (TDZ), kinetin (Kin) and indole-3-acetic acid (IAA) were found to induce multiple shoots. Shoot organogenesis was induced in the five explants. The highest mean for number of shoots per petioles (31.54±5.76) and rooted hypocotyls (44.00±1.51) with a 100% induction rate was obtained on Murashige and Skoog (MS) medium fortified with 0.4 mg/L IAA and 3.0 mg/L ZT. MS medium containing 0.4 mg/L IAA and 3.0 mg/L TDZ was found to be optimal for shoot regeneration of roots, leaves and nodal segments. The highest regeneration frequency (100%) with mean numbers of shoots equal to 38.77±6.87 for roots, 42.73±7.75 for leaves and 56.73±7.98 for nodal segments was produced. Regenerated shoots rooted effectively on half-strength MS medium and acclimatized successfully in soil with a 100% survival rate and normal growth. The protocol can be used for the large-scale propagation of S. nigrum to meet the increasing demand of commercial cultivation.
A qualitative analysis of the individual compounds in Litsea fulva (locally known as ‘Medang’) essential oils was performed by comprehensive two-dimensional gas chromatography (GC × GC) coupled with time-of-flight mass spectrometer (TOF/MS) for the identification of the resolved peaks. Litsea fulva essential oil was found to contain 98 identifiable peaks with 32 compounds were identified with good matches. These compounds identified included 30 hydrocarbons, 22 alcohols, five acids, 16 ketones, five aldehydes, 12 esters, six ethers and two other compounds. The L. fulva leaf oil contained alcohols and ethers, with 34.09% and 24.38%, respectively. The major components of these oils were cis-Z-α-bisabolene epoxide (9.51%), trans-Z-α-bisabolene epoxide (8.36%), C13H20O2 (7.39%), longipinocarvone (5.68%), τ-Cadinol (4.24%), C15H24O (4.98%) and α-cadinol (3.95%). The study also showed that the comprehensive two-dimensional gas chromatography (GC × GC) is a better and more powerful separation tool in GC and an identification tool for analyzing complex volatile oils compared with the one-dimensional GC.
The objective of this study was to assess the effectiveness of the 5A’s smoking cessation intervention (5A’s) to that of brief advice (BA) conducted by dentists. A single-blinded randomized controlled trial was designed to compare the effectiveness of the interventions. Six Dental Public Health specialists were recruited, randomized and trained to participate in this trial. Two hundred and fifty patients were required on both arms. The main outcome measures were biochemically validated self-reported abstinence and behaviour change at 6-months follow-up. The odd of quitters in 5A’s intervention was 3.81 (95% CI: 1.87-7.76; p= 0.00) times higher compared to BA. After controlling other factors, the odds ratio for the 5A’s was 1.90 (95% CI: 0.652-5.547; p=0.24) higher compared to BA. The 5A’s was found to be more effective in initiating positive behaviour change compared to BA. However, after controlling other factors, there was no difference in the effectiveness although the odds ratio was slightly higher in 5A’s.
Many researchers have developed various economic ordering quantity models by assuming an infinite time horizon and constant demand rate. However due to rapid technological advancement, shorter product life cycle and severe competition, those assumptions are no longer realistic. In this paper, we complement that shortcoming by considering an inventory model that satisfies a continuous time-varying demand rate for a finite time horizon when trade credit period and unit cash discount are allowed. The time horizon consists of n different cycles with equal or different cycles length. The trade credit period was assumed to be proportional to the cycle length. We developed mathematical models and presented a numerical example to support the effectiveness of these models.
A retrospective study of the incidence of Giant Papillary Conjunctivitis (GPC) seen in the Optometry clinic in Universiti Kebangsaan Malaysia from 1989 to 1994 was carried out. In the period of the 6 years, 37 contact wearers were diagnosed to have GPC. Of the 37 patients, 21 were Malays (57%), 12 were Chinese (32%) and the remaining 4 patients were Indians (11%). 18 or 48% of those with GPC were soft lens wearers, 46% of the wearers (17 patients) were rigid gas permeable lens wearers and 1 of the patients seen was a hard (PMMA) wearer (3%) and the other one was a disposable lens wearer (3%). Thirty patients were female (81%) and 7 (19%) were male. The age range of those with GPC were between 9 to 60 years old.
Study site: Optometry clinic, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
X-ray computed tomography (XCT) became an important instrument for quality assurance in industry products as a
non-destructive testing tool for inspection, evaluation, analysis and dimensional metrology. Thus, a high-quality image
is required. Due to the polychromatic nature of X-ray energy in XCT, this leads to errors in attenuation coefficient
which is generally known as beam hardening artifact. This leads to a distortion or blurring-like cupping and streak in
the reconstruction images, where a significant decrease in imaging quality is observed. In this paper, recent research
publications regarding common practical correction methods that were adopted to improve an imaging quality have been
discussed. It was observed from the discussion and evaluation, that a problem behind beam hardening reduction for the
multi-materials object, especially in the absence of prior information about X-ray spectrum and material characterizations
would be a significant research contribution, if the correction could be achieved without the need to perform forward
projections and multiple reconstructions.
Selenium (Se) has been recognized as an essential nutrient for humans. Plant foods are the predominant source of selenium and majority of dietary selenium is absorbed depending on the type of food consumed. Nowadays, green tea is becoming increasingly popular for its prominent health benefits, including the ability to supplement selenium in organically bound, natural food form. The selenium content of Se-enriched green tea is influenced by the selenium level of local soils in which it is grown. However, selenium content of plants can also be improved by artificial fortification methods. In this review, the chemical speciation and biological functions of selenium, fortification methods, biological activities and nutraceutical applications of Se-enriched green tea are discussed. This review provides insights into the current research and the importance of Se-enriched green tea in the enrichment of human nutrition and health.
This paper attempts to give a detailed review and provide a complete description on the technology, physics and modeling of various Multi-Gate MOSFETs. It consists of a synopsis of mathematical depiction of the potential distribution along the channel of various MG-MOSFETS which can be made to enable fast computer analysis of device behavior. This serves a link between process technology and circuit design. This review demonstrates that this technology is strongly desired in nanoscale domain and there is a plenty demand for analytical model which can explain the physics and operation of the devices perfectly.
Sperata aor is a freshwater catfish of Bagridae family which is distributed throughout Indian subcontinent including India, Bangladesh, Pakistan, Nepal and Myanmar. It is a popular food fish due to its good taste and high nutritional value. Recently it has also made its entry in domestic ornamental fish markets of India and has been reported to have moderate export price too. Earlier, few works on different aspects of its morphology and biology have been carried out but no consolidated review is available on these aspects. Therefore, the current work was done to sum up all available information on these aspects to fill the information gap that will be beneficial to its future fishery. Considering all available information, knowledge on food and feeding habit of this fish species is satisfactory, except detail information on spatial variation of its breeding periodicity, proper information on other aspects are still lacking. No work has been conducted to examine its captive culture potential or for induced breeding. Further work should be done to explore its future fishery.
For testing the homogeneity of variances, modifications of well-known tests are known which combine rigorous theory with resampling (bootstrap). We propose versions of these tests, which are computationally simpler (although asymptotically equivalent). The earlier procedures used the smooth bootstrap with two thousand bootstrap replications per sample whereas our proposals use only the classical bootstrap (or percentile method) with just one thousand bootstrap replications per sample, and also required much less computing time. Our proposals cover the Ansari-Bradley-, Mood- and Klotz-tests. We explain their superiority over the existing methodologies available in textbooks and packages.