Grain size analysis of surface fluvial sediments in rivers in Kelantan, Malaysia

Grain size spectrum and textural parameters for the fluvial sediment bed in seven tropical rivers of Kelantan, Malaysia are presented in this article. The samples were collected from six tributaries to the main Sungai Kelantan spanning approximately 248 km stretch of water streams. Sand or gravel dominated river was identified for each river using the sediment composition analysis. Textural pattern shows complicated profiles of mean size and no consistent decreasing grain size and gradation parameter were observed towards the downstream flow. Most of the samples fall under the category of either very poorly sorted or poorly sorted and has very platykurtic kurtosis distributions. CM diagram (C=one percentile in microns and M = median grain size in microns) suggested that the deposition of fine-grained sediment for samples with median grain size d50 <1 mm are either by rolling, rolling and saltation or saltation and suspension

The interaction between oscillating-grid turbulence and a sediment layer

The critical conditions for incipient sediment motion induced by oscillating-grid generated turbulence interacting with a sloping sediment layer were investigated experimentally. Near-spherical monodisperse sediments were used throughout with relative densities of 1.2 and 2.5 and mean diameters(d)ranging between 80 and 1087 μm. Interaction characteristics were analysed in terms of the critical Shields parameter θc, defined using the peak root mean square (r.m.s) horizontal velocity component in the near-bed region. Bed slope effects on θc were investigated by tilting the bed (and the grid) at angles between 0 and the repose limit. In all cases, the grid was aligned to be parallel to the bed surface, so that the oscillation direction is always normal to bed surface. The measured values of θc on a horizontal bed were comparable to the values reported in the traditional Shields diagram with θc seen to increase monotonically for hydraulically smooth bedforms and to be approximately constant for hydraulically rough bedforms. To account for bed slope effects, the measured values of θc were compared with a force-balance model based on the conditions for incipient grain motion on a sloping bed. For hydraulically smooth bedforms, where the bed roughness is small compared to the boundary-layer depth, the model was derived to account for how viscous stresses act to damp the drag and lift forces acting on the near surface sediment. For hydraulically rough bedforms, where this viscous-damping effect is not present, the model assumes the standard approach with the drag and lift forces scaling with the square of the near-bed (inviscid)velocity scale. In both cases the model predicts the bedforms to become more mobile as the bed slope is increased. However, the damping effect of the viscous sublayer acts as a stabilizing influenced for hydraulically smooth bedforms, to reduce the rate at which the bed mobility increases with bed slope. The measured values of θc in the hydraulically rough bedforms were in agreement with the trends predicted by this model. However, measured θc in smooth bed cases were lower than predicted, and fall on the hydraulically rough trend when bed slope is < 20. When the bed slope reaches the repose limit, θc falls between the smooth-bed and rough-bed cases. Measurements of sediment trajectories due to the turbulence interacting with the bed were obtained, for a range of impact conditions. Observations of the sediment trajectories during the interaction show the individual sediment grains to be predominantly displaced in a circular 'splash'. Data showed that the ‘splash’ feature and particle entrainment within the turbulence structure was within one eddy turnover time

Effect of aeration and dilution on continuous bioethanol production in a packed-bed bioreactor by saccharomyces cerevisiae

Stability of cell growth was achieved continuously at a steady state in a packed-bed bioreactor. The highest productivity of ethanol was achieved (0.02 g/L/h) when 0.003 vvm was employed. The productivity of bioethanol increases when dilution rate increases. The highest production of 0.037 g/L/h was recorded when the dilution rate (D) was at 0.05 per hour. The production of bioethanol was sucessfully maintained in a non 100% anaerobic condition. The best aeration for the continous production of bioethanol in a condition of steady state growth was at an aeration rate of 0.003 vvm

Physiological and growth response of rice plants (Oryza sativa L.) to Trichoderma spp. inoculants

Trichoderma spp., a known beneficial fungus is reported to have several mechanisms to enhance plant growth. In this study, the effectiveness of seven isolates of Trichoderma spp. to promote growth and increase physiological performance in rice was evaluated experimentally using completely randomized design under greenhouse condition. This study indicated that all the Trichoderma spp. isolates tested were able to increase several rice physiological processes which include net photosynthetic rate, stomatal conductance, transpiration, internal CO(2) concentration and water use efficiency. These Trichoderma spp. isolates were also able to enhance rice growth components including plant height, leaf number, tiller number, root length and root fresh weight. Among the Trichoderma spp. isolates, Trichoderma sp. SL2 inoculated rice plants exhibited greater net photosynthetic rate (8.66 μmolCO(2) m(−2) s(−1)), internal CO(2) concentration (336.97 ppm), water use efficiency (1.15 μmoCO(2)/mmoH(2)O), plant height (70.47 cm), tiller number (12), root length (22.5 cm) and root fresh weight (15.21 g) compared to the plants treated with other Trichoderma isolates tested. We conclude that beneficial fungi can be used as a potential growth promoting agent in rice cultivation

Threshold criteria for incipient sediment motion on an inclined bedform in the presence of oscillating-grid turbulence

Here, we report laboratory experiments to investigate the threshold criteria for incipient sediment motion in the presence of oscillating-grid turbulence, with the bed slope inclined at angles between the horizontal and the repose limit for the sediment. A set of nine mono-disperse sediment types was used with size ranges normally associated with either the hydraulically-smooth or transitional regimes. Measurements of the (turbulent) fluid velocity field, in the region between the grid and bedform's surface, were obtained using two-dimensional particle imaging velocimetry. Statistical analysis of the velocity data showed that the turbulence had a anisotropic structure, due to the net transfer of energy from the normal to the tangential velocity components in the near-bed region, and that the fluctuations were dominant compared to the secondary mean flow. The sediment threshold criteria for horizontal bedforms were compared with, and found to be in good qualitative agreement with the standard Shields curve. For non-horizontal bedforms, the bed mobility was found to increase with increasing bed slope, and the threshold criteria were compared with previously-reported theoretical models, based on simple force-balance arguments

Youth Awareness Level towards Sustainable Development Goals (SDGs) in Greater Kuala Lumpur

In 2015, the United Nations initiated the Sustainable development goals (SDGs) to address the global changes while ensuring better and sustainable actions for the future. Among Asian countries, Malaysia has also made an effort to integrate the SDGs into its national development plan. In this study, the awareness level of youth from high schools in Greater Kuala Lumpur towards Sustainable Development Goals has been assessed through questionnaires with 60 questions given to 421 respondents. Sufficient levels of feedbacks for the whole population were acquired (Confidence level: 95%, Margin of error: 5%). Five schools were selected and grouped into 3 types: high-performance school (national merit of excellence), cluster school (state level merit of excellence), and daily school (normal achievement). The results of the Spearman Rho correlation showed a significant but weak relationship [r= 0.435] between attitude and practice for all schools. Interestingly, the statistical test showed a negligible relationship between knowledge and attitude, and knowledge and practice, indicating a low attitude to practice SDGs amongst youth although equipped with adequate knowledge. The study also found that high-performance schools showed the highest score for all knowledge, attitude, and practice

Optimisation of ammonium tartrate and glucose concentration for gamma linolenic acid production by Cunninghamella sp. 2A1.

The effects of ammonium tartrate and glucose concentration on biomass, lipid and GLA accumulation in Cunninghamella sp. 2A1 were investigated using Response Surface Methodology (RSM). Cultivation was carried out in 250 mL shake flask containing 100 mL of nitrogen limiting medium (with various combinations of concentration of ammonium tartrate (1-3 g/L) and glucose (30-60 g/L) at 30°C and 250 rpm agitation for 120 h. The concentration of both compounds significantly affected the biomass, lipid and GLA yield (p<0.05), with the production of each of them being represented by quadratic models. Higher concentration of ammonium tartrate and glucose (2.99 and 59.33 g/L, respectively) was required for enhanced biomass production whereas low nitrogen content with excess glucose was otherwise favoured for lipid and GLA production. Ammonium tartrate and glucose concentration at 1 and 43 g/L, respectively were estimated by the model and proven to give the highest lipid production and GLA yield of 31.06 % (g/g biomass) and 4.15 ×10-2 (g/g lipid less biomass), respectively

Medium Optimization for the Production of Lipidless Biomass By Cunninghamella sp. 2A1 Using Response Surface Methodology

A statistical design approach has been used to optimize the production of biomass by Cunninghamella sp. 2A1, evaluated based on lipidless biomass. A 2^3 full factorial central composite design (CCD) was chosen to study the combined effects of three factors; ammonium tartrate, peptone and glucose concentrations. The p-value for each factor was <0.05 suggesting that these factors have significant effects on the production of lipidless biomass. The production is represented by a linear model with p-value <0.0001. The optimized medium consisting of 3.86g/L ammonium tartrate, 55.84g/L glucose and 7.73g/L peptone predicted a lipidless biomass of 16.83g/L. Results from four replications based on the optimized medium produced an average of 18.48g/L lipidless biomass, which is in close agreement with the predicted value. The coefficient for glucose was the highest indicating it to be the most significant factor affecting lipidless biomass production

Hybrid systems for robotic navigations

This paper presents a development of hardware and software of hybrid systems for autonomous robot navigation. The task for this robot is to navigate through a given field and throwing shuttlecocks through a hoop to dedicated zones. It is vital for the robot to have navigational systems for robot movement. This work develops a robot with hybrid systems using encoder, digital fiber sensor and fiber optic sensor. This work embraced mechanical parts and programming parts for robot navigations. To achieve this smooth navigation, rotary encoder was embedded on the robot tails, and left and right side of the robot. This will enable the robot to move in correct positioning. Furthermore, digital fiber sensor is used for color detection as each color gives difference response, and fiber optic sensor for detection of hindrance or fence. The hybrid approach is observed to be competent for the robot to navigate autonomously and effectively in unknown environments. It has been shown that the motion of the robot can be operated as target conditions and shows that color and hindrance or fence plays an important role in navigation system

DNA Isolation and Optimization of ISSR-PCR Reaction System in Oryza sativa L.

Inter simple sequence repeats (ISSRs) have been utilized widely for molecular markers in analyzing the genetic diversity and phylogenetic and regions in the genome flanked by microsatellite sequences. PCR amplification of these regions using a single primer yields multiple amplification products that can be used as a dominant multilocus marker system for the study of genetic variation in various organisms. For this study provides, DNA isolation, adjusting in six factors (Buffer, MgCl2, dNTPs, ISSR primers, Template DNA and Taq polymerase) at six levels, and optimization of PCR temperature for the ISSR reaction was 60-45 °C, primers screening on indica rice (Oryza sativa). In this research, simple method of DNA isolation by using seedling. The objective of the present investigation was to assess the optimizations and quantification. Has been shown that stalk enhanced the maximum value of genomic. The results show that 100 ISSR primers were examined as well as, 56 ISSR primers was productively amplified. Optimum components for PCR reactions were 5.0 μl of 5X PCR Buffer, 1.5 μl of 25mM MgCl2, 1 μl of 10 mM dNTP, 1 μl of 10 Μm ISSR primers, 2 μl Template DNA, and 0.1 μl of 5 units/ml Taq polymerase. Based on this study, has brought out some information on the relationship between these ISSR primers will be applied further for molecular profiling as well as response evaluation in rice varietie