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In tropical agroecosystems, limited N availability remains a major impediment to increasing yield. A 15N‐recovery experiment was conducted in 13 diverse tropical agroecosystems. The objectives were to determine the total recovery of one single 15N application of inorganic or organic N during three to six growing seasons and to establish whether the losses of N are governed by universal principles. Between 7 and 58% (average of 21%) of crop N uptake during the first growing season was derived from fertilizer. On average, 79% of crop N was derived from the soil. When 15N‐labeled residues were applied, in the first growing season 4% of crop N was derived from the residues. Average recoveries of 15N‐labeled fertilizer and residue in crops after the first growing season were 33 and 7%, respectively. Corresponding recoveries in the soil were 38 and 71%. An additional 6% of the fertilizer and 9.1% of the residue was recovered by crops during subsequent growing seasons. There were no significant differences in total 15N recovery (average 54%) between N from fertilizer and N from residue. After five growing seasons, more residue N (40%) than fertilizer N (18%) was recovered in the soil, better sustaining the soil organic matter N content. Long‐term total recoveries of 15N‐labeled fertilizer or residue in the crop and soil were similar. Soil N remained the primary source of N for crops. As higher rainfall and temperature tend to cause higher 15N losses, management practices to improve N use efficiency and reduce losses in wet tropical regions will remain a challenge.

This paper objective is to share design revolution of waste and delivery valve that contribute to the overall pump performance. In this paper, 3 new designs of waste and delivery valve pump are presented with comprehensive internal flow analysis using computational fluid dynamics (CFD) simulation over 4 cases that have been deeply study for one of the design chosen. 4 cases involving opening and closing both valve or either one. 0.265m height size of customized waste valve with an opening limiter and spring was used to demonstrate cyclic closing and opening valve operation extended up to 0.164m gap. Based on result, this characteristics contribute to 10-20% waste water reduction and enhancement of flow rate height up to 80m. Apart from that this paper also share some of pressure (dynamic, total, static), velocity (x, y, z axis) simulation including the vector flow were under different flow cases.

The hydro-pneumatic accumulator is broadly used in heavy industry as leaking compensator. Lately, much interest has been developed to study the component as energy storage. The important element in the selection of accumulator is performance. Hence, research was conducted to examine the use of thermal process condition and its impingement on the accumulator as an energy store. For charging process, the performance is influenced by the thermal process because it involves temperature change and heat transfer. Both processes are producing a different performance. The storage system is planned to be adapted in the dual hybrid driveline. A simulation study has been conducted by using Automation Studio software which focusses on two different processes called isothermal and adiabatic. The process has involved a schematic design, functional testing, parameter setting, and pretense. The result has shown that the thermal process affected the fluid power parameters such as power, effective storage capacity, and temperature differentials. The isothermal process produced higher effective volume compared to adiabatic process, stored higher power and had lower temperature differentials. Regarding charging speed, the adiabatic was faster. However, it was a lack of storage capacity.

Hydraulic ram pump is device that can lift water to the higher position without use of external energy. Several ways have been tested to decrease the water waste rate to maximize efficiency. The purpose of this research work is to develop a new design of hydraulic pump and conduct simulation study to justify improvement of the design. Major addition on making threaded waste valve system in order to control the opening and closing of the valve. At the same time reduce time taken for creating enough momentum and hammering effect. The results revealed that with the advancement of the proposed well improve designs, the water losses at waste valve reducing about 20-30% compare to existing design across the mass flow rate of 0.10 kg/s.The min/max velocity and pressure along the pipeline also has been increase for both open and closed condition.

Composite titanium dioxide (TiO2) and zinc oxide (ZnO) thin films were deposited on indium tin oxide (ITO) substrates using sol-gel spin coating technique. The electrical and physical characterizations of three different sol-gel spin coating speed were investigated using two-probe current-voltage (I-V) measurement, field emission scanning electron microscopy (FESEM) and surface profiler (SP) respectively. The I-V measurement results showed the pinched hysteresis loop for every single of devices thus indicate that all the devices are memristive. ROFF/RON ratio which was defined from the hysteresis loop of device with higher spin speed was slightly higher compared to others.

Plug-in hybrid electric motorcycle (PHEM) is an alternative to promote sustainability lower emissions. However, the PHEM overall system packaging is constrained by limited space in a motorcycle chassis. In this paper, a chassis applying the concept of a Chopper is analysed to apply in PHEM. The chassis 3dimensional (3D) modelling is built with CAD software. The PHEM power-train components and drive-train mechanisms are intergraded into the 3D modelling to ensure the chassis provides sufficient space. Besides that, a human dummy model is built into the 3D modelling to ensure the rider?s ergonomics and comfort. The chassis 3D model then undergoes stress-strain simulation. The simulation predicts the stress distribution, displacement and factor of safety (FOS). The data are used to identify the critical point, thus suggesting the chassis design is applicable or need to redesign/ modify to meet the require strength. Critical points mean highest stress which might cause the chassis to fail. This point occurs at the joints at triple tree and bracket rear absorber for a motorcycle chassis. As a conclusion, computational analysis predicts the stress distribution and guideline to develop a safe prototype chassis.

Simulation by convenient software, the same as FLUENT, was used to predict the friction factor and Nusselt number for forced convection heat transfer of TiO2-water nanofluid. The range of Reynolds number is from 10000 to 100000 to be turbulent flow in a horizontal straight tube with heat flux 5000 w/m2 around it. The volume fraction of nanoparticle was (0.25%, 0.5%, 0.75% and 1%) and diameter of particle is 27 nm. The results show that the friction factor and Nusselt number are increasing with increasing of volume fraction. Results compared with the experimental data available in literature and there are good agreements.

Nano-magnesium oxide (Nano-MgO) had successfully deposited on glass substrate using sol-gel spin coating technique at different drying temperature (100, 200 and 300degC). The dielectric layer properties of deposited nano-MgO films were investigated in terms of its resistivity, leakage current density, relative permittivity, topology and morphology respectively. Changing in drying temperature resulted in variation of nano-MgO films properties and film dried at 200degC has compact, uniform, less porous and in nano size that lead to the enhancement in relative permittivity value.

One-dimensional engine model is developed to simulate spark ignition engine processes in a 4-stroke, 4 cylinders gasoline engine. Physically, the baseline engine is inline cylinder engine with 3-valves per cylinder. Currently, the engine's mixture is formed by external mixture formation using piston-type carburettor. The model of the engine is based on one-dimensional equation of the gas exchange process, isentropic compression and expansion, progressive engine combustion process, and accounting for the heat transfer and frictional losses as well as the effect of valves overlapping. The model is tested for 2000, 3000 and 4000 rpm of engine speed and validated using experimental engine data. Results showed that the engine is able to simulate engine's combustion process and produce reasonable prediction. However, by comparing with experimental data, major discrepancy is noticeable especially on the 2000 and 4000 rpm prediction. At low and high engine speed, simulated cylinder pressures tend to under predict the measured data. Whereas the cylinder temperatures always tend to over predict the measured data at all engine speed. The most accurate prediction is obtained at medium engine speed of 3000 rpm. Appropriate wall heat transfer setup is vital for more precise calculation of cylinder pressure and temperature. More heat loss to the wall can lower cylinder temperature. On the hand, more heat converted to the useful work mean an increase in cylinder pressure. Thus, instead of wall heat transfer setup, the Wiebe combustion parameters are needed to be carefully evaluated for better results.