Fluvial processes in compound straight channels: a laboratory investigation

Floods are become frequent occurrence in every part of the world. The field of flood hydraulics has been keenly studied to enhance the understanding on its processes and impacts to the environment. The main impacts of frequent floods incidents are soil erosion phenomenon which leads to sedimentation problems in the drainage and river systems. It is extremely important to understand the sedimentation process and the flow behaviour patterns in the water course for post-flood events. Experimental investigations on the overbank flow in mobile bed straight channels have been undertaken. Significant changes on the bed morphology due to the changes in flow behaviour are studied. The findings on roughness coefficient, lateral distribution of stream-wise velocity, secondary currents, bed shear stress and bed formation are presented in this paper. Results show that the resistance coefficient increased with flow depth in the channel and the increments are about 32% and 42% for floodplain and main channel sections respectively

Flood flow characteristics and bed load transport in non-vegetated compound straight channels

Floods are the most common natural disasters in Malaysia and have damaged structures, infrastructures, crops and even causes fatalities. It may also lead to erosion and sedimentation in rivers and this will result to complex river behaviour. A hydraulic laboratory experimental study was carried out. Also, flood flow and sediment transport in straight compound channels involving flow resistance, distribution of depth-averaged velocity, stream-wise vorticity patterns, channel bed morphology and bed load transport rate in non-vegetated compound straight mobile bed channels were investigated. The finding showed that the Darcy Weisbach friction factor f increased by 40% and 54% for floodplain and main channel, respectively when relative flood flow depth increase from 0.30 to 0.50. The small bed load transport rates of 0.09 g/s and 0.03 g/s for shallow and deep overbank flows, respectively were measured due to effect of very gentle or mild channel bed slope which was fixed at a gradient of 0.1%

Torrefaction of palm biomass briquettes at different temperature

The climate change has driven towards transformation from the high energy dependence on fossil fuel to inexhaustible renewable energy such as solar, wind, mini hydro and biomass. In Malaysia, abundant of palm biomass residues are produced during the processing of fresh fruit bunch. Therefore it is inevitable to harness these bioenergy sources in order to prevent waste accumulation at adjacent to palm mills. In order to utilize such bioenergy sources and to cope with the fast growing demand of energy, combination technique of densification and torrefaction is one of the potential ways to be practised. In the present study, the physical and combustion properties of torrefied empty fruit bunch (EFB) briquettes were investigated experimentally with constant nitrogen flow rate of 1 l/min, for various torrefaction temperatures (225 °C-300 °C). Before torrefaction process, EFB briquettes were initially produced under controlled condition with compaction pressure of 7 MPa and briquetting temperature of 150 °C. In general, the torrefied EFB briquettes were successfully produced in the present study. The results show that an increase in torrefaction temperature from 225°C to 300℃ causes a significant increase in gross calorific value (from around 17400 kJ/kg to 25000 kJ/kg), fixed carbon content (from 16.2% to 46.2%) and ash content (from 2.4% to 17.2%). On the other hand, relaxed density and volatile matter decrease, from 1017 kg/m3 to 590 kg/m3 and from 73.1% to 29.7%, respectively. As a conclusion, the gross calorific value and fixed carbon content are improved due to torrefaction. In addition, it was found that gross calorific value and moisture content of the torrefied EFB briquettes fulfil the requirement for commercial briquette production as stated by DIN51731 (gross calorific value>17500 kJ/kg and moisture content <10%)

The Role of Solar Wind Hydrogen in Space Weathering: Insights from Laboratory-Irradiated Northwest Africa 12008

Micrometeoroid impacts, solar wind plasma interactions, and regolith gardening drive the complicated and nuanced mechanism of space weathering (or optical maturation); a process by which a materials optical properties are changed as a result of chemical and physical alterations at the surface of grains on airless bodies. Reddened slopes, attenuated absorption bands, and an overall reduction in albedo in the visible and near-IR wavelength ranges are primarily the result of native iron nanoparticle (npFe0) production within glassy rims that form from sputtering and vaporization. The sizes and abundance of these particles provide information about the relative surface exposure age of a particular grain. In addition, many studies have indicated that composition greatly affects the rate at which optical maturation occurs. Despite our understanding of how npFe0 affects optical signatures, the relative roles of micrometeoroid bombardment and solar wind interactions remains undetermined. To simulate the early effects of weathering by the solar wind and to determine thresholds for optical change with respect to a given mineral phase, we irradiated a fine-grained lunar basalt with 1 keV H+ to a fluence of 6.4 x 1016 H+ per sq.cm. Surface alterations within four phases have been evaluated using transmission electron microscopy (TEM). We found that for a given fluence of H+, the extent of damage acquired by each grain was dependent on its composition. No npFe(0) was produced in any of the phases evaluated in this study. These results are consistent with many previous studies conducted using ions of similar energy, but they also provide valuable information about the onset of space weathering and the role of the solar wind during the early stages of optical maturation

A three competing species model for wastewater treatment: case study on Taman Timur oxidation pond, Johor Bahru

Oxidation pond techniques have practically proved to be effective for wastewater treatment process (WWTP) because of their low construction and operating cost. Cumbersome sampling is required to monitor the dynamics of the WWTP which also involves enormous costly work. Deterministic model accommodating the correlation between the amount of phototrophic bacteria in a product called mPHO (bioproduct used to improve water quality) and pollutant (bacteria E.coli and Coliform) existing in oxidation pond is developed to facilitate the analysis of this process. This study presents ordinary differential equation model for an oxidation pond to investigate the effect of mPHO on the degradation of pollutant. The model consists of a system of ordinary differential equations (ODE) with coupled reaction equations for the pollutant and phototrophic bacteria. The parameters of the model is estimated using the real data collected from an aerobic oxidation pond located in Taman Timor, Johor, Malaysia to illustrate a real life application of this model. The simulation results provide a better understanding of the ecological system in the oxidation pond

Crop-based irrigation operations in the North West Frontier Province of Pakistan. Vol.II: Research approach and interpretation. Final Report

Irrigation management / Crop-based irrigation / Research / Irrigation canals / Water demand / Performance evaluation / Agricultural production / Pakistan / North West Frontier Province

Application of ANFIS in Predicting of TiAlN Coatings Hardness

In this paper, a new approach in predicting the hardness of Titanium Aluminum Nitrite (TiAlN) coatings using Adaptive Neuro-Fuzzy Inference System (ANFIS) is implemented. TiAlN coated cutting tool is widely used in machining due to its excellent properties. The TiAlN coatings were formed using Physical Vapor Deposition (PVD) magnetron sputtering process. The substrate sputtering power, bias voltage and temperature were selected as the input parameters and the hardness as an output of the process. A statistical design of experiment called Response Surface Methodology (RSM) was used in collecting optimized data. The ANFIS model was trained using the limited experimental data. The triangular, trapezoidal, bell and Gaussian shapes of membership functions were used for inputs as well as output. The results of ANFIS model were validated with the testing data and compared with fuzzy and nonlinear RSM hardness models in terms of the root mean square error (RMSE) and model prediction accuracy. The result indicated that the ANFIS model using 3-3-3 triangular shapes membership function obtained better result compared to the fuzzy and nonlinear RSM hardness models. The result also indicated that the ANFIS model could predict the output response in high prediction accuracy even using limited training data

Dynamical behavior of a cancer growth model with chemotherapy and boosting of the immune system

In this study, we set up and analyze a cancer growth model that integrates a chemotherapy drug with the impact of vitamins in boosting and strengthening the immune system. The aim of this study is to determine the minimal amount of treatment required to eliminate cancer, which will help to reduce harm to patients. It is assumed that vitamins come from organic foods and beverages. The chemotherapy drug is added to delay and eliminate tumor cell growth and division. To that end, we suggest the tumor-immune model, composed of the interaction of tumor and immune cells, which is composed of two ordinary differential equations. The model’s fundamental mathematical properties, such as positivity, boundedness, and equilibrium existence, are examined. The equilibrium points’ asymptotic stability is analyzed using linear stability. Then, global stability and persistence are investigated using the Lyapunov strategy. The occurrence of bifurcations of the model, such as of trans-critical or Hopf type, is also explored. Numerical simulations are used to verify the theoretical analysis. The Runge–Kutta method of fourth order is used in the simulation of the model. The analytical study and simulation findings show that the immune system is boosted by regular vitamin consumption, inhibiting the growth of tumor cells. Further, the chemotherapy drug contributes to the control of tumor cell progression. Vitamin intake and chemotherapy are treated both individually and in combination, and in all situations, the minimal level required to eliminate the cancer is determined