A good quality of rainfall data is highly necessary in hydrological and meteorological analyses. Lack
of quality in rainfall data will influence the process of analyses and subsequently, produce misleading
results. Thus, this study is aimed to propose modified missing rainfall data treatment methods that
produced more accurate estimation results. In this study, the old normal ratio method and the
modified normal ratio based on trimmed mean are combined with geographical coordinate method.
The performances of these modified methods were tested on various levels of the missing data of 36
years complete daily rainfall records from eighteen meteorology stations in Peninsular Malaysia. The
results indicated that both modified methods improved the estimation of missing rainfall values at the
target station based on the least error measurements. Modified normal ratio based on trimmed mean
with geographical coordinate method is found to be the most appropriate method for station Batu
Kurau and Sg. Bernam while modified old normal ratio with geographical coordinate is the most
accurate in estimating the missing data at station Genting Klang.
This study investigates the effect of oxalic acid at different concentrations as doping agent on
the electrical properties of polyaniline (PANI). The polymerization of aniline to produce
PANI was carried out in media containing oxalic acid at 0.08 M, 0.09 M, 0.1 M, 0.2 M and
0.3 M in the presence of ammonium persulphate as oxidizing agent. The successful formation
of PANI doped with oxalic acid was confirmed by FTIR and the morphology studied using
XRD. An impedance investigation on the series of PANI formed revealed that doping in 0.1M
oxalic acid produced PANI of the highest conductivity of 2.52 x 10-6
Scm-1.
The interrelationship between freshwater availability with the growing population and climate change
estimates is complex. This article investigates climate change role in freshwater resources availability. This
is critical issue as freshwater is vital resource for life, and it is in stake as it is depleted worldwide.
Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) was
discussed. This paper elucidates the climate model downscaling methods used by scholars for future
projections. The applications of modelling could provide a holistic approach based on historical data to
predict the effect of climate change on the availability of freshwater. However, the people variability
uncertainties dominate assessments of freshwater stress, whilst climate change projections uncertainties are
more hypothesized to play a smaller role than people.
The Pandanus species (Pandanaceae family) was investigated, in order to set up a library of their chromatographic profiles. From a literature review, the most common Pandanus plant that was greatly examined was P. amaryllifolius (the fragrant screw pine), followed by P. sanderi. Here, the chromatographic data from an extract of a relatively unfamiliar Pandanus is also presented. The leaves of P. monotheca were extracted by using methanol. Later, the extract was filtered, prior to a Reversed-Phase High Performance Liquid Chromatography (RP-HPLC) experiments. The automated system was set to run by gradient elution (acetonitrile:water). The flow rate was maintained at 1 ml/min, otherwise stated in a number of attempts. The ultra-violet absorbance of the Pandanus’ constituents was measured via Multiple Wavelength Detector. From the chromatogram, the major peaks for Pandanus’ compounds were eluted (λ = 220, 260 and 360 nm) and the retention times were recorded. The lower absorbance readings of other minor peaks could be due to various minor secondary metabolites, such as the furolignan. The different elution time depends on the polarity of the composition. In short, Pandanus’ phytochemicals could be obtained via alcoholic extraction. The utilisation of modern chromatographic applications enables the scientists to discover and subsequently, purify single component of the complex natural mixtures. This finding can be beneficial to the research areas in botanical study, pharmacognostical assessment and biotechnology industry. It is aimed that more
Pandanus species could be learnt for the future.
In this study the role of Polymer flooding as one of the most efficient processes to enhance oil
recovery (EOR) is discussed. As we know, Polyhydroxybutyrate (PHB) is a bio-based polymer that
has potential application for use in polymer flooding. This polymer is reviewed with particular
emphasis on the effect of concentration, shear rate, salinity, hardness and temperature on polymer
viscosity. Initial findings showed that PHB owned higher resistant as compared to mechanical
degradation and thermal stability of HPAM as well as XG.
Anthropogenic CO2 emissions has led to global climate change and widely contributed to global
warming since its concentration has been increasing over time. It has attracted vast attention
worldwide. Currently, the different CO2 capture technologies available include absorption, solid
adsorption and membrane separation. Chemical absorption technology is regarded as the most
mature technology and is commercially used in the industry. However, the key challenge is to
find the most efficient solvent in capturing CO2. This paper reviews several types of CO2 capture
technologies and the various factors influencing the CO2 absorption process, resulting in the
development of a novel solvent for CO2 capture.
The electrical resistivity and flexural strength of plastic composites reinforced with pineapple leaf particles (PCPLP) is presented. PCPLP were produced using different plastic materials; Polyethylene (PE) and Polypropylene (PP), and different plastic pineapple leaf particle ratios; 50:50 and 70:30. The PCPLP were tested and evaluated with respect to electrical resistivity and flexural strength according to ASTM D257 and D790, respectively. The results indicate that PCPLP made from PP exhibits better electrical resistance than PE, which may be attributed to the better frequency insulation behaviour ofPP. PCPLP using the higher ratio of 70:30 also exhibited better electrical resistance than the lower 50:50 ratio. Cellulose materials inherently influence the electrical resistance of plastic composites, due to their natural propensity to absorb moisture. The PCPLP produced using a ratio of 50:50 for both PP and PE composites exhibited better MOE results than the 70:30 composites, however the converse is true with respect to the MOR. MOE of PCPLP was increased with increasing pineapple leaf particles content due to the greater matrix stiffness of this natural particle with respect to plastic matrix. However, high percentage offiller particles in the matrix (70:30 ratio) has reduced the toughness in the composite structure due to the lost ofphysical contact between high accumulated particles.
Accurate inspection of welded materials is important in relation to achieve acceptable standards. Radiography, a non-destructive test method, is commonly used to evaluate the internal condition of a material with respect to defect detection. The presence of noise in low resolution of radiographic images significantly complicates analysis; therefore attaining higher quality radiographic images makes defect detection more readily achievable. This paper presents a study pertaining to the quality enhancement of radiographic images with respect to different types of defects. A series of digital radiographic weld flaw images were smoothed using multiple smoothing techniques to remove inherent noise followed by top and bottom hat morphological transformations. Image quality was evaluated quantitatively with respect to SNR, PSNR and MAE. The results indicate that smoothing enhances the quality of radiographic images, thereby promoting defect detection with the respect to original radiographic images.
Collagen was extracted from catfish (Clarias gariepnus) waste using 0.5M acetic acid and its subsequent precipitation in 2.6M NaCl. The resultant collagen was analysed with respect to its moisture content and physicochemical properties including yield, pH, protein content, colour, odour and thermal stability. A yield of 16.4% and positive collagen attributes indicate that catfish waste has potential as a collagen source. The snowy white, crystal-like and light textured collagen comprises of 5.97% protein and 0.46% moisture, and exhibits a pH of 4.75. Sensory evaluation indicates that the collagen has a slight fishy odour. Viscosity analysis indicates a steady decrease with increasing temperature over the range considered (20-50°C). The pale colour exhibited and limited odour emitted by the extracted collagen indicate that catfish waste collagen could be applied in the food industry without resulting in any undesirable food products attributes. Differential Scanning Calorimetry (DSC) analysis indicated that the collagen exhibits good thermal stability and denatures at a high temperature in a similar manner to mammalian collagen.
Molecular self-assembly is ubiquitous in nature and has emerged as a new approach to produce new materials in chemistry, engineering, nanotechnology, polymer science and materials. Molecular self-assembly has been attracting increasing interest from the scientific community in recent years due to its importance in understanding biology and a variety of diseases at the molecular level. In the last few years, considerable advances have been made in the use of peptides as building blocks to produce biological materials for wide range of applications, including fabricating novel supra-molecular structures and scaffolding for tissue repair. The study of biological self-assembly systems represents a significant advancement in molecular engineering and is a rapidly growing scientific and engineering field that crosses the boundaries of existing disciplines. Many self-assembling systems are range from bi- and tri-block copolymers to DNA structures as well as simple and complex proteins and peptides. The ultimate goal is to harness molecular self-assembly such that design and control of bottom-up processes is achieved thereby enabling exploitation of structures developed at the meso- and macro-scopic scale for the purposes of life and non-life science applications. Such aspirations can be achieved through understanding the fundamental principles behind the selforganisation and self-synthesis processes exhibited by biological systems.
Tinospora crispa Miers (Menispermaceae) is a climbing vine with stems rich in warts. The plant is called Akar Seruntum or Patawali in Malaysia and is widely used for treating skin complaints, malaria, bacterial abscess, high blood pressure and diabetes. In the present study, the stems of T. crispa were collected from the locality and succesively extracted with petroleum ether, followed by chloroform and ethanol. The insecticidal active extract (ethanol extract) was subjected to column chromatography of silica gel eluted with a gradient mobile phase containing hexane, chloroform and ethanol. Among the chemical constituents isolated are n-tetracosyl trans-ferulate and n-octacosyl alcohol, along with three known aporphine alkaloids; N-formylnornuciferine, N-acetylnornuciferine and lysicamine. All compounds were identified by comparing their spectroscopic data (UV, IR, 1H NMR, MS) with data from corresponding values in the literature. Isolation of n-tetracosyl trans-ferulate and noctacosyl alcohol is reported the first time for T. crispa.
Silver catfish (Pangasius sutchi) skin gelatin was extracted to determine the effects of extraction time on the functional properties of the gelatin in terms of solubility, protein solubility as a function of pH and sodium chloride concentration, emulsifying capacity and stability, water holding capacity, fat binding capacities and foaming properties. Silver catfish skins were washed in sodium chloride (NaCl) solution prior to pre-treatment in sodium hydroxide (NaOH) and acetic acid solution. Gelatin was extracted at 50ºC for 6, 8, 10 and 12 hours extraction time followed by freeze drying. The extraction of silver catfish skin gelatin at 50 ºC for 12 hours was more effective than extraction at 6, 8 and 10 hours where the gelatin was characterized by higher emulsifying capacity (52.63%), emulsifying stability (47.83%), water holding capacity (31.78 mL/g), fat binding capacities (54.76%), foaming capacity (41.47 mL) and foaming stability (56.42%) than gelatins extracted at other extraction time. The longer the extraction time, the better the functional properties of the gelatin. Based on its good functional properties, silver catfish skin gelatin may be useful in various food applications such as soups, sauces and gravies.
Polymers and organic materials that are exposed to sunlight undergo photooxidation, which leads to deterioration of their physical properties. To allow adequate performance under outdoor conditions, synthetic polymers require additives such as antioxidants and UV absorbers. A major problem with optimising polymer formulations to maximise their working life span is that accelerated weathering tests are empirical. The conditions differ significantly from real weathering situations, and samples require lengthy irradiation period. Degradation may not be apparent in the early stages of exposure, although this is when products such as hydroperoxides are formed which later cause acceleration of oxidation. A simple way of quantifying the number of free radicals presents in organic materials following exposure to light or heat is by measuring chemiluminescence (CL) emission. Most polymers emit CL when they undergo oxidative degradation, and it originates from the bimolecular reaction of macroperoxy radicals which creates an excited carbonyl.
This paper outlines the application of chemometrics and pattern recognition tools to classify palm oil using Fourier Transform Mid Infrared spectroscopy (FT-MIR). FT-MIR spectroscopy is used as an effective analytical tool in order to categorise the oil into the category of unused palm oil and used palm oil for frying. The samples used in this study consist of 28 types of pure palm oil, and 28 types of frying palm oils. FT-MIR spectral was obtained in absorbance mode at the spectral range from 650 cm -1 to 4000 cm -1 using FT-MIR-ATR sample handling. The aim of this work is to develop fast method in discriminating the palm oils by implementing Partial Least Square Discriminant Analysis (PLS-DA), Learning Vector Quantisation (LVQ) and Support Vector Machine (SVM). Raw FT-MIR spectra were subjected to Savitzky-Golay smoothing and standardized before developing the classification models. The classification model was validated through finding the value of percentage correctly classified by test set for every model in order to show which classifier provided the best classification. In order to improve the performance of the classification model, variable selection method known as t-statistic method was applied. The significant variable in developing classification model was selected through this method. The result revealed that PLSDA classifier of the standardized data with application of t-statistic showed the best performance with highest percentage correctly classified among the classifiers.
Aluminium (Al) is a low cost, lightweight and corrosion resistant material, which corrodes when exposed to pitting agents. Palm olein exhibits characteristics, which indicate its suitability as a corrosion inhibitor. Tween 20, hexane and diethyl triamine were used as additives to Palm olein to form the inhibitor formulation POT2OHA. The inhibition efficiency (IE) and behaviour of the POT2OHA were determined using potentiodynamic polarization in which Al 6061 samples were immersed in a 1 M HC1 solution at 26, 50 and 70 °C in the presence of different POT2OHA concentrations: 0, 0.03, 0.07, 0.10, 0.13 and 0.17 M The IE increased with increasing POT2OHA concentration, but decreased with increasing temperature. The work presented indicates that POT2OHA is a mixed-type inhibitor capable of inhibiting both corrosive anodic and cathodic reactions. According to the Langmuir isotherm results POT2OHA adsorbs on the A16061 surface through semiphys iosorption and/or semi-chemisorption. The POT2OHA adsorption mechanism on Al 6061 takes through the protonation of micelles by the HC1 solution, whereby protonated micelles in the presence of chloride ions adsorb on both cathodic and anodic surface corrosion sites.
Malaria parasites, Plasmodium can infect a wide range of hosts including humans and rodents. There are two copies of mitogen activated protein kinases (MAPKs) in Plasmodium, namely MAPK1 and MAPK2. The MAPKs have been studied extensively in the human Plasmodium, P. falciparum. However, the MAPKs from other Plasmodium species have not been characterized and it is therefore the premise of presented study to characterize the MAPKs from other Plasmodium species-P. vivax, P knowlesi, P berghei, P chabaudi and P.yoelli using a series of publicly available bioinformatic tools. In silico data indicates that all Plasmodium MAPKs are nuclear-localized and contain both a nuclear localization signal (NLS) and a Leucine-rich nuclear export signal (NES). The activation motifs of TDY and TSH were found to be fully conserved in Plasmodium MAPK1 and MAPK2, respectively. The detailed manual inspection of a multiple sequence alignment (MSA) construct revealed a total of 17 amino acid stack patterns comprising of different amino acids present in MAPK1 and MAPK2 respectively, with respect to rodent and human Plasmodia. It is proposed that these amino acid stack patterns may be useful in explaining the disparity between rodent and human Plasmodium MAPKs.
Cyclic guanosine monophosphate (cGMP) is a second messenger molecule involved in the intracellular signalling mechanism which is important in a wide range of cellular process including metabolism, gene expression, cell proliferation and cell death. This study was conducted to determine the effect of fresh (FCC)) and thermoxidized carotino oil (TCO) on erythrocyte cGMP levels from Sprague dawley rats. A total of 30 Sprague dawley rats were randomly segregated into three groups: the first of which was placed on a Fresh Carotino Oil (FCO) diet, the second on a Thermoxidized Carotino Oil (TCO) diet and the control group on commercial rat chow only for a period of 6 and 9 weeks. The two oil diets comprised of 20% (w.10 of each oil mixed with commercial rat,feed. The enzyme immunoassays, performed in week 6, revealed that the erythrocytes cGMP levels for the FCO and TCO groups were 66.198±3.193 pmol/mL and 61.990±6.318 ptnol/mL respectively, and were significantly (p
Mercury emission into the atmosphere is a global concern due to its detrimental effects on human health in general. The two main sources of mercury emission are natural sources and anthropogenic sources. Mercury emission from natural sources include volcanic activity, weathering of rocks, water movement and biological processes which are obviously inevitable. The anthropogenic sources of mercury emission are from coal combustion, cement production and waste incineration. Thus, in order to reduce mercury emission it is appropriate to investigate how mercury is released from the anthropogenic sources and consequently the mercury removal technology that can be implemented in order to reduce mercury emission into the atmosphere. Many alternatives have been developed to reduce mercury emission and the recent application of activated carbon showed high potential in the adsorption of elemental mercury. This paper discusses the ability of activated carbon and variable parameters that influence mercury removal efficiency in flue gas.
Anion clay hydrotalcite MgA1C0 3 with a Mg/A1 molar ratio of 3:1 was synthesized by co-precipitation at room temperature and pressure. The physicochemical properties were evaluated using Powder X-Ray Diffraction (PXRD), Fourier Transform Infrared (FTIR) spectroscopy and Thermogravimetric Analysis (TGA). The efficacy of anion clay hydrotalcite in the removal ofCcf- from aqueous solutions was investigated with respect to contact time, initial concentration, pH, adsorbent dosage and temperature. The Cd2- removal increased with the increased in contact time, adsorbent dosage, pH and initial concentration. Adsorption decreases with increasing initial concentration and temperature, for which the latter is indicative of an exothermic process. The equilibrium adsorption capacity of MgA1C0 3 was evaluated using linear Langmuir and Freundlich isotherms with respect to the separation factor, RL.
Recently, research and development in the field of drug delivery systems (DDS) facilitating site-specific therapy has reached significant progression. DDS based on polymer micelles, coated micro- and nanoparticles, and various prodrug systems including water-soluble polymer have been prepared and extensively studied as novel drugs designed for cancer chemotherapy and brain delivery. Since polymers are going to be used in human, this study has the interest of testing two types of polymer, polyimides (PI) and polyphenylenevinylene (PPV) on neuronal cells. The objective of this study was to determine the possible neurotoxicity and potential neuroprotective effects of PI and PPV towards SH-SY5Y neuronal cells challenged by hydrogen peroxide (1120) as an oxidant. Cells were pretreated with either PI or PPV for 1 hour followed by incubation for 24 hour with 100 ,uM of 11201. MTS • assay was used to assess cell viability. Results show that PI and PPV are not harmful within the concentration up to 10 pM and 100 pM, respectively. However, PI and PPV do not protect neuronal cells against toxicity induced by H2O, or further up the cell death.