Physical and acoustic properties of petroleum and renewable based polyurethane foam filled with shorea leprosula

Physical and acoustic properties of petroleum-based polyurethane (PU) and renewable based polyurethane (RPU) foam composites filled with Shorea Leprosula (Red Meranti) fiber filler has been investigated. Shorea Leprosula wood dust namely as SL was used as the filler. RPU was used with hope to substitute the current polyurethane. This research was carried out to investigate the physical and acoustical properties and the ability of polymer foam composites (PF) towards sound absorption coefficient (SAC) based on the wood fiber size with range of 150-200 μm (powder), 250-300 μm (fibrous) and 900-1000 μm (flakes). 5 wt%, 10 wt%, 15 wt% and 20 wt% of SL filler content and thickness of 10 mm, 20 mm and 30 mm were used for each PF sample. PF samples have been tested by using Impedance Tube test, Scanning Electron Microscopy (SEM) and Mettler Toledo Density kit. As a result, the sound absorption coefficient (SAC) shows value at achievable frequency range at low (0-1500 Hz) and high (1501-6000 Hz) frequency absorption level. PU with powder fiber size (UP20), average pore size with 425.4 μm (smallest), and density 857.9 kg/m3 (highest) shows better sound behaviour with SAC value of 0.2478 and 0.9598 at low and high frequency absorption level. Meanwhile, for RPU with powder fiber size (RP20), average pore size with 479.8 μm (smallest), and density 839.0 kg/m3 (highest) shows better sound behaviour with SAC value of 0.2478 and 0.9940 at low frequency and high frequency absorption level. Moreover, UP20 and RP20 give the highest SAC value with 30 mm in thickness 0.9037 and 0.9909, and 0.9784 and 0.9809 at low and high frequency absorption level respectively. In conclusion, acoustical characteristics of PF samples shows the ability to influence the absorption coefficient of polymeric foam at different frequency levels. Both type of PF produce is suitable for sound absorbing materials for indoor and outdoor sound applications

Removal of Chromium from Aqueous Stream Using Aluminium Oxide (Synthesized by Simple Precipitation Method) as an Adsorbent

Several studies have been done on discovering the potential of alumina as an adsorbent to remove heavy metal such as chromium. The purpose of this project is to analyse and study effect of initial concentration of chromium, contact time between adsorbent and chromium, and also adsorption kinetics of adsorbent. For this project, to remove chromium from aqueous stream, the potential of aluminium oxide has been explored. Aluminium oxide which was used was synthesized by simple precipitation method where it produced by reaction between aluminium chloride and ammonium hydroxide. The capability of synthesized aluminium oxide to remove chromium by adsorption was compared with commercial aluminium oxide. Based on the FESEM result, the pictures of both morphologies showed that synthesized aluminium oxide had better structure and more uniform pores than commercial aluminium oxide. Batch adsorption kinetic studies showed that the adsorption of chromium ion was strongly affected by initial chromium ion concentration. The amount of chromium ion adsorption on aluminium oxide was increased with initial chromium ion concentration which was from 20 ppm until 80 ppm. It also was found that the amount of adsorption was increased with contact time at a fixed solution pH, amount of adsorbent, initial chromium ion concentration, temperature and velocity of stirring until the equilibrium concentration was achieved at 180 minutes (3 hours). A kinetic experiment for adsorption of chromium ion on aluminium oxide was followed pseudo-second-order kinetics because of higher regression coefficients, R2 which is 0.9776 and theoretical equilibrium sorption capacity, qe (17.361 mg/g) was more similar with respect to experimental qe (14.5473 mg/g). For adsorption isotherm, Langmuir adsorption equations reasonably describe the adsorption isotherm within this chromium ion concentration range. Based on the Langmuir isotherm, R2 is 0.886. In this project, it was clearly proven that synthesized aluminium oxide was better than commercial aluminium oxide in terms of the morphology and also the capability of adsorbing chromium which adsorbed 14.5473 mg/g and 12.7326 mg/g respectively. As conclusion, considering the high capability of aluminium oxide synthesized by simple precipitation method as an adsorbent of chromium in aqueous solution via adsorption, it is essential to encourage more researches by manipulating the morphology of aluminium oxide in order to resolve the pollution of chromium in waste water

Efficient cultivation of Kluyveromyces Lactis in high cell density culture in fed-batch cultivation system

Kluyveromyces lactis is beneficial and well-known yeast due to its status of GRAS that has made the yeast as a vital microorganism for the subject of studies and also the applications of industry such as a possible source of single-cell protein with expected probiotic properties, oligonuci eotide-derived flavour enhancers and lactic acid. In addition,High Cell Density Cultivation (HCDC) of K. lactis has been scientifically and biotechnologically important trend in improving microbial mass and product formation substantially.More importantly,fed-batch strategy has been identified as another effective mean to increase the yield by preventing substrate limitation or inhibition through maintaining medium substrate concentration at a low level during cultivation.In this study,there were two system cultivations have been employed which was batch cultivation and fed-batch cultivation. Further studies have been done under batch cultivation on the aeration effect and dissolved The results showed that 1.0 v/v/inin aeration rate gave relatively high cell dry weight, CDW, 18.6 gIL. On the contrary, the results from DO stat value of 60% showed substantial increment with CDW of 28.7 gIL.As for the fed-batch study, constant feeding rate strategy has been applied with two different feeding substrates i.e complete media and mono-lactate. The CDW harvested for complete media had showed remarkable result, 59.75 g/L as compared to CDW produced from lactose as a sole feeding substrate, 44.75 g/L.02,DO

Design of Transmission Line Tower and Its Performances

Many tower failure cases are reported due to several conditions such as broken wire condition, earth wire broken, vandalism and also earthquake. The lower failures can be avoided by identifying the damage mechanism and improving the tower design. The tower can be designed using different codes of practices. However, currently, there is no comparison being made regarding the load acting on tower bodies if the tower design according to different codes of practices

Modulation of gut microbiome by probiotics in obesity and related metabolic abnormalities / Mohd Shafiq Aazmi

Accumulating evidence suggests that the aberrant taxonomic composition of gut microbiota is one of the etiological factor in the development of obesity. With the inherent plasticity of gut microbiota structure, it provides a new avenue for the application of biotherapeutics to modulate the shifted structure of microbiota in obesity. Lately, much attention has been focused on probiotic as a biotherapeutics candidate for obesity. In contrast, knowledge on the modulating effects of probiotic on the obese gut microbiota structure is still limited and should be evaluated. The present study aims to elucidate the inherent plasticity of gut microbiota and the dynamic response of the host metabolism during the induction of high-fat-diet-induced obesity and upon the amelioration of obesity by probiotics in obese rat models. Two probiotic candidates; (i) single strain Lactobacillus casei strain Shirota (LAB13) and (ii) probiotic cocktail LACTO-5™ (L. rhamnosus, L. acidophilus, B. subtilis, B. longum and S. thermophilus) were supplemented to the obese rats at doses of 1 ×109 CFU per/day/rat for 12 weeks. The probiotic treatment started after the induction of obesity using high fat diet (HFD, 60% fat). The heterogeneity of gut microbiota structure and its functional complement genes were profiled from the faecal samples of rats from each intervention group (n=3/group) using shotgun metagenomics sequencing. Phenotypically, the weight gain, energy intake, subcutaneous fat, total fat weights, total cholesterol, leptin, ratio of TC to HDL-c and leptin to adiponectin in obese rats were significantly reduced by the supplementation of both probiotics. These confirmed the anti-obesity, hypocholesterolemic and hypoleptinemia effects of both probiotics

Waste tyre powder-based activated carbons by Co2 activation for methylene blue and phenol removal

The development of industries in Malaysia has led to water pollution. Adsorption is an effective technique in the treatment of wastewater as it utilizes low cost adsorbent, no sludge generation, and simple to operate. Pyrolysis waste tyre powder is a suitable precursor of activated carbon due to its high carbon content, less commercial value and abundantly available. This work aims to evaluate the adsorption properties of activated carbons prepared from pyrolysed waste tyre powder for the removal of positively charged methylene blue and negatively charged phenol from water. The activated carbons were prepared by physical activation using carbon dioxide at activation temperatures of 900 to 1000 °C for 2 to 8 h. The resultant activated carbons were modified with hydrofluoric acid followed by nitric acid, and were characterized for Brunauer–Emmett–Teller surface area, pH value at the point of zero charge, scanning electron microscope, functional groups and thermal gravimetric analysis. The adsorption of methylene blue and phenol were studied at varying concentrations (5 - 200 mg/L), contact times (5 min - 72 h) and temperatures (30 - 60 oC). The isotherm, kinetics and thermodynamics models were employed to describe the adsorption data. The specific surface area of activated carbons increased with activation temperature and time. The maximum adsorption of methylene blue is 132 mg/g. The oxidized activated carbon showed an increase of methylene blue adsorption from 102 mg/g (bulk) to 107 mg/g. However, the phenol adsorption decreased from 48 to 39 mg/g after oxidation. The equilibrium data of methylene blue adsorption fitted well with the Langmuir and Redlich-Peterson models, while that of phenol adsorption obeyed the Freundlich isotherm. The kinetics data of both model pollutants could be described by the pseudo-second-order model. The rate-limiting step in the adsorption of methylene blue and phenol could be dominated by pore diffusion. The positive enthalpy change and entropy change indicate that the adsorption of methylene blue is endothermic and spontaneous at high temperatures, while the phenol adsorption is exothermic and spontaneous at low temperatures. In conclusion, the activated carbons prepared are feasible to be used as an adsorbent

TENSILE AND FLEXURAL PROPERTIES OF COMMINGLED KENAF/PET REINFORCED POLYPROPYLENE HYBRID COMPOSITES

Commingled hybrid composite has a potential to improve further the physical and mechanical properties. However, very limited studies have been done on commingled hybrid composite. Therefore, this project was proposed to study the effects of commingled hybrid composite of PP/kenaf/PET on tensile and flexural properties. The PP/kenaf/PET composite was manufactured by compression moulding. Due to the constraint of mould cavity, only two compositions were produced i.e. 85/10/5 and 85/5/10 (PP/kenaf/PET) wt.%. Tensile strengths of commingled 85/5/10 were increased by 48% and 13% compared to neat PP and non-commingled 85/5/10, respectively. However, commingled hybrid composite showed an adverse effect to tensile modulus and flexural properties compared to that of non-commingled composite

Apa sainsnya petua, azimat dan nujum?

Masyarakat Melayu sekian lama telah didendangkan dengan segala ilmu lama daripada nenek moyang mereka. Ilmu orang-orang Melayu ini dizahirkan dalam bentuk petua, azimat, bernujum dan banyak lagi yang dianggap sebagai suatu yang kolot, tidak rasional dan tidak mempunyai nilai sains. Penjajahan Tanah Melayu oleh Portugis, Belanda dan Inggeris telah menjadi pencetus kepada budaya ilmu berorientasi barat dalam kalangan orang Melayu. Inggeris sebagai contoh telah membuka sedikit ruang kepada golongan elit Melayu mengikuti pengajian beroriantasikan Barat, secara tidak langsung telah mula mengubah persepsi masyarakat Melayu terhadap ilmu tradisional Melayu serta mereka ini mula menilai semula ilmu tradisional Melayu berasaskan nilai baru yang dipelajari. Dalam makalah ini diperjelaskan aspek-aspek sains dan teknologi amnya dan matematik khususnya dalam ilmu petua, nujum dan azimat. Aspek ini bukanlah hanya kerana mahu memadankan ilmu ini dengan ilmu sains sekarang tetapi mahu penyelidik sekarang melihat ilmu ini daripada sisi dan sudut yang berlainan. Aspek sains dan matematik yang dapat dilihat adalah seperti pengiraan hari dalam pembinaan rumah, pemberian nama anak berdasarkan tarikh lahirnya dan pengiraan bintang-bintang disentuh dalam makalah ini

Teknologi masyarakat Minangkabau dalam Perang Padri di Sumatera Barat

Perang Padri merupakan perang saudara yang telah berlaku di Sumatera Barat iaitu di kawasan Minangkabau pada tahun 1803 hinggalah 1838. Ianya berlaku akibat pertelagahan antara kaum yang memegang Adat dan kaum Padri yang berpegang teguh dengan Islam. Pihak Adat kemudiannya bergabung dengan Belanda untuk menyingkirkan kekuasaan pihak Padri. Apa yang menjadi persoalan adalah mengapakah Belanda mengambil masa yang begitu lama untuk menundukkan perjuangan kaum Padri. Oleh yang demikian, makalah ini akan membincangkan tentang persediaan yang dilakukan oleh kaum Padri bagi mempertahankan tanah airnya daripada dijajah oleh Belanda. Persediaan pejuang Padri adalah daripada sudut strategi peperangan, binaan kubu pertahanan yang kuat dan juga penggunaan persenjataan. Pihak Belanda sendiri mengakui kesukaran untuk mengalahkan pihak Padri sehinggakan masalah ini sampai kepada raja di Belanda. Boleh dikatakan persediaan yang dilakukan oleh pejuang Padri ini merupakan sebuah pencapaian teknologi atau etno-teknologi bagi masyarakat Minang. Ianya kurang dibincangkan kerana beberapa penulis sebelum ini tidak melihat persiapan ini sebagai suatu bentuk teknologi yang datang daripada pemikiran masyarakat Minangkabau

Study on sediment characteristics and prediction of sediment load at Galing River

A study on sediment was conducted at the various station in Galing River. There were three secondary data and one new data that will used in this research. Secondary data was consumed from three different days in order to take the samples which are 28/02/13, 13/03/13 and 27/03/13 and the latest data was conducted on 15/11/2017. This study was conducted to determine the sediment characteristic such as sediment concentration, size, density, and sediment load with the factors influencing sediment transportation. Four sampling stations were chosen, the first one with to data at upstream Galing River (Station 1 and Station 4), mid-stream Galing River (Station 2) and downstream Galing River (Station 3). Parameter were collected at the station, such as river discharge values or flow rate, depth and wide of river and the density of the river. In this study, sediment grain size is acquired through sieve analysis. For sediment concentration (mg/L), it is measured by Total Suspended Solid (TSS). While, sediment load is calculated by using Duboy’s sediment transport function. It is preferred to use Duboy’s as all samples passed this function's requirement compare than other function. Duboy’s function required median size (D50) and mean grain size (Dm). Overall, the findings of the study show that the sizes of sediment at Galing River based on Wentworth scale fall between (0.71 to 1.0mm) which indicates coarse sand type and has one sizes between (1mm to 2mm) which indicates very coarse sand. On the other hand, the average suspended sediment concentration recorded for each station shows varying values. The values were 0.010mg/L at Station 1, 0.022mg/L at Station 2, 0.015mg/L at Station 3 and 0.034mg/L at Station 4. For sediment load, the values were the highest at the station between four different days at Station 1, Station 2, Station 3 and Station 4 were 0.8009 kg/sec-m, 0.8500kg/sec-m, 5.8442kg/sec-m and 0.5222 kg/sec-m respectively. Lastly, factors influencing sediment transportation at Galing River were identified where the factors are size of sediment, rainfall, vegetal covers, human's activities (effluent and garbage), river's hydraulic (flow rate), soil erosion and river's geometric (width and depth)