The importance of zeolite surface area and pore volume in adsorption processes has been much reported in literature. In addition to that, structural framework and pore network system may also influence the adsorption capacity and selectivity of methane on zeolite. This paper discusses the characteristics of methane adsorption based on several physical properties of the adsorbents such as surface area, pore volume, pore network system and its interaction with adsorbate. The study, using FTIR spectroscopy showed that the adsorbed methane at room temperature was detected in the FTIR region between 3200 cm–1 – 1200 cm–1. Based on the physical properties of the adsorbents and the FTIR spectra of adsorbed methane, the surface area was not the only factor that determined methane adsorption; in fact the type of pore network system of the adsorbent also affected the interaction, thus affecting the adsorption of methane in zeolite.
Ordered microporous NaY zeolite and mesoporous copper oxide are high performance material as catalysts and adsorbents. The copper oxide-NaY zeolite modification in combination of their physicochemical properties could provide excellent opportunities for the creation of new gas adsorbents. In this study, modified NaY zeolite properties and methane adsorptive characteristics were investigated by dispersing copper oxide onto the NaY zeolite structure using the thermal dispersion method. The structures of the copper oxide modified zeolites were characterized by powder X-ray diffraction and Micromeritics ASAP 2000, while the methane adsorption characteristics were analyzed using a thermogravimetric analyzer. The results revealed that types of copper oxide, copper oxide loading concentration, calcination temperature and calcination time greatly affected the modified zeolite structure and gas methane adsorption characteristics.
In this study the effects of phosphorus and nitrogen levels, temperature and light-dark cycle on the algal growth potential (AGP) of an Antarctic Chlorococcum isolated from an ephemeral stream at Reeve Hill, Antarctica was investigated. The highest AGP was attained when the cultures were grown at high nitrogen concentration (329.87 mg NO3-N/l) and low phosphorus concentration (2.6 mg PO4-P/l) at 4ºC on a 12 h:12 h light-dark cycle. The results showed that Chlorococcum sp. required a high concentration of nitrogen, low concentration of phosphorus, low temperature with equal lengths of light and dark period (12 h:12 h) for optimum growth.
Since its invention, polyimide (PI) has been widely used in micro-electro-mechanical system (MEMS) devices. For fabrication, the PI membrane, PI-2723 HD-Microsystems was used as the membrane material due to its Young's modulus of 2.7 GPa and its film thickness could easily be controlled by changing the speed of the spin coater system. The application PI as membrane structure on silicon wafers therefore gave a much better mechanical performance then conventional membranes made of silicon dioxide (SiO2) or silicon nitride (Si3N4) layers. The fabrication of PI membrane was the same as for SiO2 and Si3N4 membranes; the basic step was to etch a side of the silicon wafer using wet anisotropic etching. This paper proposes an effective process for fabrication of PI membrane with f ast and little supervision. In this process, a dual step process was wet anisotropic etching of single crystal silicon using pottasium hydroxyl (KOH) with different concentrations and temperature processes. For the first process, 45% KOH under boiling temperature was used to etch at least 90%–95% of the silicon. In the second process, the silicon was submerged in 45% KOH with temperature at 70ºC–80ºC to etch away the residual silicon until a clean and transparent PI membrane was achieved. Using this method, the fabrication of PI membrane could be generated fast.
Research and development trends will continue to design innovative composite foods in which muscle proteins are combined with non-conventional animal products, non-meat proteins and functional food additives, many of which have lost their original inherent properties and characteristics. Composite food are products with meat, non-meat proteins, fats, carbohydrates and functional ingredients such as pre-emulsion, probiotics, enzymes, bioactives, peptides, hormones, emulsifiers, gelatin, animal fats/oils, alcohol and visceral tissues. Traceability of halal meat raw materials should start at the point of animal breeding, production to the stage of halal slaughter, processing operations and final point of consumption. Traceability of food additives used in the food industry remains a major hurdle for the Muslim community seeking halal food. The processes and technological advancements made in raw material processing, ingredient extractions, modifications, purification and resynthesized into many food ingredients make the question of traceability and solving of the materials and processes that are halal a monumental task. Food is only halal if the entire food chain from farm to table, is processed, handled and stored in accordance with the syariah and/or halal standards or guidelines, such as in the Jabatan Kemajuan Islam Malaysia (JAKIM): General guidelines, Malaysia Standards MS 1500:2009 and Codex Alimentarius (Food Labeling). Here lies the challenge and importance of traceability to verify the ‘wholesomeness’ of the sources of halal raw materials and final meat-based food products.
A study was undertaken to estimate the histological changes of gingival enlargement induced by
Cyclosporin A (CsA) and Nifedipine, separately and in combination. Twelve adult rabbits were divided equally into four main groups. The first group received 10 mg/kg/day Nifedipine, the second received 10 mg/kg/day CsA, and the third received a combination of 10 mg/kg /day Nifedipine and CsA by gastric feeding. The fourth was regarded as a control group. Animals were given the drugs from day 1 of the experiment until day 70. They were then sacrificed for histological purposes. Results showed increase in the thickness of the epithelium with keratosis and acanthosis, and also increased vascularity. Collagen fibres and fibroblasts at different rates in the three histological groups were observed. Significant alveolar bone resorption with increased marrow spaces filled with fatty tissue were found in the CsA group. Non-significant changes in the alveolar bone of the Nifedipine group while subsequent bone resorption and bone deposition were seen in the combination group. These changes could be due to the effect of both drugs. Significant changes in the gingiva and the alveolar bone were shown in the three experimental groups compared with the control group.
Molecular markers have been intensively used in assisting breeding to reduce the time taken by conventional breeding as well as helping introgression of specific traits. Baseline analysis of known markers is crucial in developing a genetic database on disease and pest resistance for local rice germplasm which does not yet
exist. In this study seven local rice varieties, including the popular MR219 and MRQ 74 and MRQ 76 (newly developed aromatic rice varieties), together with a foreign variety, Intani-2, were screened for genetic markers related to pest and disease resistance. One hundred and twenty-two type-related markers (SSR, STS, InDel and Allele-specific) for genes resistant to bacterial leaf blight, blast and brown planthopper were screened using PCR amplification and validated by sequencing. It was found that each variety had its own pattern of resistance. Using allele-specific markers namely pBPH9, pTA248 and Pisbdom were found to be the most efficient way to screen for the targeted genes. Of the seven varieties, MR219 and MR232 were found to have the highest distribution of markers for resistance genes against pest and diseases studied.
This article uses finite volume and finite element methods for optimization of the artificial hair cell sensor. The performance of the sensor was investigated for different materials such as sicon and polysilicon and by varying hair cell dimensions including width and length. The silicon material which has low young modulus was proposed based on the simulation performance. The performance of the hair cell sensor was achieved by increasing the hair cell length while increasing the width did not significantly influence the performance. The
performance of the sensor was studied for its viscous force, deflection, von mises stress and sensitivity. From the simulation, the hair cell with a length of 1600 µm and 80 µm width was suggested for the subsequent analysis. Another way to improve the performance was by modifying the hair cell geometry and it was proved that the modified hair cell was more sensitive, based on the deflection. The angle of flow that hit the hair cell also affected the deflection of the sensor where the zero angle flow which was parallel to the substrate was the most effective angle. The limitations of the performance of hair cell for various fluid velocity were also discussed in this paper.
Nowadays, construction and demolition waste has become a major issue to environmental problems faced by many countries. This concern comes from the inefficiencies of waste management which includes the waste generated from construction and demolition activities. In Malaysia, there is a lack of database records on construction waste and this has affected proper management planning of the waste. As there is a lack of policy on construction waste management, control on construction waste disposal is very hazy and this has aggravated environmental problems and exhausted landfill usage and increased illegal dumping. This paper reviews the critical issues on construction waste management and also discusses several estimation models on construction waste generation from several countries. Based on the review, most of the countries faced problems regarding construction waste management and the models developed were considered as one of the methods which could be adopted for better management of construction wastes.
In December 2009, at the UN Climate Change Conference COP 15 in Copenhagen, the Prime Minister of Malaysia, the Rt. Hon. Mohd Najib Abdul Razak, had announced that “Malaysia is adopting an indicator of a voluntary reduction of up to 40% in terms of emissions intensity of GDP by the year 2020 compared to 2005 levels. This indicator is conditional on receiving the transfer of technology and finance of adequate and effective levels from Annex 1 partners, that correspond to what is required in order to achieve this indicator”. Malaysia also needs to decouple its GDP from its current relatively high carbon-based energy demand. In trying to meet both these targets, we need to intensify our research efforts in energy-based areas. As government funding in R&D is limited as the aim is for research to be private-sector driven, and with the grim global economic scenario today, it is most unlikely that Malaysia will get any assistance financially or technologically from Annex 1 nations. It is therefore proposed that Malaysia considers implementing a dedicated carbon cess on petroleum products to fund R&D in the country. (Copied from article).
Awareness and sensitivity on the subject of green technology are currently commanding the attention of the world in the light of rising energy costs and the threat of global warming. Many countries are now recognizing the benefits of researching into and using green technology to reduce their carbon and water footprints and to minimize waste. (Copied from article).
Thoracic trunk shift and Coronal balance are main features to be considered while planning
treatment for scoliosis patients. Thoracic trunk shift refers to deviation of trunk from its
normal position. Coronal balance refers to deviation of seventh cervical bone from sacrum
in coronal plane. After undergoing scoliosis correction surgery, these two parameters are
measured by surgeons using radiograph images to make sure the scoliosis curve progression
is stopped and whether vertebral alignment is back to normal. Since the relationship
between thoracic trunk shift and coronal balance in the post-operated scoliotic patients is
questionable, this study is done to find the correlation between thoracic trunk shift and
coronal balance in the thoracic scoliosis patients who underwent correction surgery at least a
year before from the date of taking radiographs. Radiographs of 24 patients were collected.
Statistical analysis was done using paired sample ‘t’ test, with ‘p’ value of 0.05 as the level of
significance. The mean millimetre measurement of thoracic trunk shift and coronal balance
was found to be 27.62 mm and 10.50 mm. Results of our study showed that there is a 10.18%
of relation in between the post thoracic trunk shift and coronal balance of those 24 patients.
Exploiting the merits of superconducting properties, a series of thermal profile was employed
to modify the melt-textured growth of Y−Ba−CuO bulk with BaTiO3 epitaxial
crystal seed. Two thermal routes were used whereby multiple heatings of the samples were
conducted at 940 ◦C and 960 ◦C before elevating to 1040 ◦C and 1070 ◦C, respectively. Our
finding shows that the optimum melt-textured growth window is narrow within the temperature
range of 1010−1040 ◦C. Above the peritectic temperature, partial decomposition of
YBa2Cu3O7−δ (Y123) into YBa2Cu3O5 (Y211) leads to the formation of Y211 multigrains
embedded in the matrix of Y123. The values of Tc for the superconducting Y123 obtained
using the two routes are 78 K and 71 K. The lower Tc suggests the presence of structural
distortion and non-stoichiometry of the samples.
As textile production flourishes nowadays, the amount of dyed wastewater entering the
water body has also increased. Dyes could have serious negative impacts to the environment
and also the human health, hence, they need to be removed from the water body. In this
study, layered double hydroxide (LDH) of manganese/aluminium (MnAl) was synthesised
to be used as a potential adsorbent to remove methyl orange (MO) dye due to its unique
lamellar structure which provides LDH with high anion adsorption and exchange ability.
MnAl was synthesized by using co-precipitation method and characterized by powder X-ray
diffraction (PXRD), Fourier-Transform Infrared Spectroscopy (FTIR), Inductively coupled
plasma atomic emission spectroscopy (ICP-AES) and Carbon, Hydrogen, Nitrogen, Sulphur
(CHNS) elemental analysers, and Accelerated Surface Area and Porosity Analyzer (ASAP).
Adsorption studies were conducted at different contact times and dosages of MnAl to evaluate
the performance of MnAl in removing MO from water. Kinetic and isotherm models were
tested using pseudo-first order, pseudo-second order, Langmuir isotherm and Freundlich
isotherm. MnAl LDH was found to be perfectly fitted into pseudo-second order and Langmuir
isotherm.
Several binary and ternary medium- and long-chain triacylglycerol (MLCT)-enriched margarine formulations were examined for their solid fat content, heating profile, polymorphism and textural properties. MLCT feedstock was produced through enzymatic esterification of capric and stearic acids with glycerol. The binary formulations were produced by mixing MLCT feedstock blend (40%–90%) and palm olein (10%–60%) with 10% increments (w/w). Solid fat profiles of commercial margarines were used as a reference to determine the suitability of the formulations for margarine production. The solid fat content of the binary formulations of MO 82 and MO 91 (M, MLCT, O, palm olein) were similar to the commercial margarines at 25°C which met the basic requirement for efficient dough consistency. Ternary formulations using reduced MLCT feedstock blend proportion (from 80%–90% to 60%–70%) were also developed. The reduction of MLCT feedstock blend was
done as it had the highest production cost (3USD/kg) in comparison to palm olein (0.77USD/kg) and palm stearin (0.7USD/kg). The proportions of 5%–15% of palm stearin were substituted with palm olein in MO 64 and MO 73 (M, MLCT; O, palm olein) formulations with 5% increment (w/w). As a result, MOS 702010 and MOS 603010 (M, MLCT; O, palm olein; S, palm stearin) margarine formulations showed similar SFC % to the commercial margarines at 25ºC. These formulations were subsequently chosen to produce margarines. The onset melting and complete melting points of MLCT-enriched margarine formulations were high (51.04ºC –57.93ºC) due to the presence of a high amount of long chain saturated fatty acids. Most of the formulations showed β΄- crystals. MOS 702010 was selected as the best formulation due to values for textural parameters comparable (P
Malaysia is currently poised to introduce its Science, Technology and Innovation (STI) Policy and Act to bolster the nation's efforts at economic and social transformation. In championing this initiative, the Academy of Sciences Malaysia, while continuing to advise the Government on STI issues of the day, has made major strides in taking stock of the country's STI strengths in the various sectors of the economy as well as weaknesses that need to be addressed in terms of human capital development. In this article, the author examines the level of research expertise presently in the country in the field of chemistry, and elaborates on the four key areas of energy, catalysis and chemical synthesis, materials science and biological chemistry which will be researched globally in the next few decades that we would also need to be engaged upon to remain competitive. Intended for a wider audience than chemists alone, the descriptive sections in the article by and large belie an interdisciplinary flavour. The article also advocates the need for a more thorough road mapping exercise of the STI efforts in chemistry across the spectrum of academia and industry and makes some recommendations towards forging strong collaborations in research between the universities, public research institutes and the industry which are seen as vital in providing cross-cutting chemical solutions throughout the value chains and to the success of technologies identified as critical to the nation.
An analysis of the power spectral density of ultra-wideband (UWB) signals is presented in order to evaluate the effects of cumulative interference from multiple UWB devices on victim narrowband systems in their overlay bands like WiFi (i.e. IEEE802.11a) and 3rdG systems (Universal mobile telecommunications system/wideband code division multiple access). In this paper, the performances are studied through the bit-error-rate as a function of signal-to-noise ratio as well as signal-to-interference power ratio using computer simulation and exploiting the realistic channel model (i.e. modified Saleh-Valenzuela model). Several modifications of a generic Gaussian pulse waveform with lengths in the order of nanoseconds were used to generate UWB spectra. Different kinds of pulse modulation (i.e. antipodal and orthogonal) schemes were also taken into account.
A 2.4 GHz variable-gain low noise amplifier (VGLNA) intended for use in a Wide-band Code Division
Multiple Access receiver was designed in 0.18 um CMOS process for low voltage and low power applications. Rivaling classical designs using voltage mode approach, this design used the current mode approach, utilizing the current mirror principle to obtain a controllable gain range from 8.26 dB to 16.95 dB with good input and output return losses. By varying the current through the widths of transistors and a bias resistor, the VGLNA was capable of exhibiting 8 dB gain tuning range without degrading the noise figure. Therefore, higher gain was possible at lower current and thus at lower power consumption. Total power consumption simulated was 4.63 mW from a 1 V supply and this gave a gain/power quotient of 3.66 dB/mW. Comparing this with available published data, it was observed that this work demonstrated a good gain tuning range and the lowest noise figure with such power consumption.
Radiation pre-vulcanised natural rubber latex (RVNRL) prepared by using gamma irradiation technique has many advantages over the conventionally prepared sulphur pre-vulcanised natural rubber latex (SPVL). Despite the fact that many potential latex dipped products can be made from RVNRL, little effort was made to fully commercialise the products because of the inferior strength of RVNRL products compared to SPVL products. An attempt was made to improve the tensile strength of RVNRL by combining both radiation and peroxide vulcanisation in order to ensure that the products will not tear or fail, and has sufficient stretch. Hexanediol diacrylate (HDDA) plays the main role as sensitizer during radiation vulcanisation and tert-butyl hydroperoxide (t-BHPO) as the co-sensitizer in peroxide vulcanisation. Pre-vulcanised natural rubber latex dipped films via hybrid radiation and peroxidation vulcanisations obtained showed tensile strength of 26.7 MPa, an increment of more than 15% compared to controlled film (22.5 MPa). Besides, the crosslink percentage of the rubber films also showed around 5% increment from 90.7% to 95.6%.
Considering its excellent thermal stability, alkyl phosphonium surfactant: triisobutyl(methyl)phosphonium
(TIBMP) was used in this research as an intercalant for surface
modification of Na+-MMT via ion exchange process forming organomontmorillonite
(OMMT). The OMMT was then used as filler in poly(methyl methacrylate) (PMMA) via
melt intercalation technique. OMMT decomposed at a higher temperature than commercial
alkyammonium modified MMT. Exfoliated and intercalated types of nanocomposites
are obtained from PMMA/OMMTs at low and high content of OMMT loading, depending
on the space of those clay platelets had to disperse in PMMA. The ability of OMMT to
carry a certain load applied in PMMA matrix enhances the tensile strength in all composites.
TIBMP are compatible with PMMA matrix, and significantly improves the tensile
properties of PMMA composites.