Interactive Effects of Silicon and Soil pH on Growth,Yield and Nutrient Uptake of Maize

Silicon - Priming crop seeds with silicon (Si) to withstand various abiotic stresses is a novel approach. As soil pH affects dissolution of Si pools and Si uptake by plant, evaluation of this...     

EXPERIMENTAL STUDY ON DRYING OF CHILLI IN A COMBINED MICROWAVE-VACUUM-ROTARY DRUM DRYER

This paper presents new data on drying chilli in a microwave-vacuum-rotary drum dryer. This novel technique is designed to combine the advantages of vacuum drying and evenly dispersed microwave energy in a rotary drum. The drying kinetic and the specific energy consumption at particular product moisture content were measured experimentally. Moreover, the effect of pressure inside the chamber and the rotational speed of the drum were also determined.     

Formation of LiNi0.5Co0.5VO4 nano-crystals by solvothermal reaction

LiNi_0.5Co_0.5VO₄ nano-crystals were solvothermally prepared using a mixture of LiOH·H₂O, Ni(NO₃)₂·6H₂O, Co(NO₃)₂·6H₂O and NH₄VO₃ in isopropanol at 150–200 °C followed by 300–600 °C calcination to form powders. TGA curves of the solvothermal products show weight losses due to evaporation and decomposition processes. The purified products seem to form at 500 °C and above. The products analyzed by XRD, selected area electron diffraction (SAED), energy dispersive X-ray (EDX) and atomic absorption spectrophotometer (AAS) correspond to LiNi_0.5Co_0.5VO₄. V–O stretching vibrations of VO₄ tetrahedrons analyzed using FTIR and Raman spectrometer are in the range of 620–900 cm⁻¹. A solvothermal reaction at 150 °C for 10 h followed by calcination at 600 °C for 6 h yields crystals with lattice parameter of 0.8252 ± 0.0008 nm. Transmission electron microscope (TEM) images clearly show that the solvothermal temperatures play a more important role in the size formation than the reaction times.     

Facile sonochemical synthesis and photocatalysis of Ag nanoparticle/ZnWO_4-nanorod nanocomposites

A facile sonochemical method was developed to synthesize metallic Ag spherical nanoparticles on the surface of ZnWO_4 nanorods by forming heterostructure Ag/ZnWO_4 nanocomposites.The Ag/ZnWO_4 nanocomposites were characterized by X-ray powder diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),field emission scanning electron microscopy(FESEM),transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS).The experimental results showed that fcc metallic Ag nanoparticles were supported on surface of monoclinic sanmartinite ZnWO_4 nanorods.The Ag3d_(3/2) and Ag 3 d_(5/2) peaks have well-separated binding energies of 6.00 eV,certifying the existence of metallic Ag.The Ag/ZnWO_4 nanocomposites were evaluated for photodegradation of methylene blue(MB)induced by ultraviolet-visible(UV-Vis)radiation.In this research,heterostructure 10 wt% Ag nanoparticle/ZnWO_4-nanorod composites have the highest photocatalytic activity of 99%degradation of MB within 60 min.The increase in photocatalytic activity was the result of photoinduced electrons in conduction band of ZnWO_4 that effectively diffused to metallic Ag spherical nanoparticles and the inhibition of electron-hole recombination process.     

Predicting performance of radial flow type impeller of centrifugal pump using CFD

The main objective of this work is to use the computational fluid dynamics (CFD) technique in analyzing and predicting the performance of a radial flow-type impeller of centrifugal pump. The impeller analyzed is at the following design condition: flow rate of 528 m³/hr; speed of 1450 rpm; and head of 20 m or specific speed (N_s) of 3033 1/min in US-Units. The first stage involves the mesh generation and refinement on domain of the designed impeller. The second stage deals with the identification of initial and boundary conditions of the mesh-equipped module. In the final stage, various results are calculated and analyzed for factors affecting impeller performance. The results indicate that the total head rise of the impeller at the design point is approximately 19.8 m. The loss coefficient of the impeller is 0.015 when 0.6 < Q/Q_design < 1.2. Maximum hydraulic efficiency of impeller is 0.98 at Q/Q_design = 0.7. Based on the comparison of the theoretical head coefficient and static pressure rise coefficient between simulation results and experimental data, from previous work reported in the literature [Guelich, Kreiselpumpen, Springer, Berlin, 2004], it is possible to use this method to simulate the performance of a radial-flow type impeller of a centrifugal pump. This paper was recommended for publication in revised form by Associate Editor Seungbae Lee Somchai Wongwises is currently a Professor of Mechanical Engineering at King Mongkut’s University of Technology Thonburi, Bangmod, Thailand. He received his Doktor Ingenieur (Dr.Ing.) in Mechanical Engineering from the University of Hannover, Germany, in 1994. His research interests include two-phase flow, heat transfer enhancement, and thermal system design. Professor Wongwises is the head of the Fluid Mechanics, Thermal Engineering and Two-Phase Flow Research Laboratory (FUTURE). Suthep Kaewnai obtained a B. S. degree in Mechanical Engineering, 1980 from the King Monkut’s University of Technology Thonburi and M. S. degree in Mechanical Engineering, 1983 from Chulalongkorn University. He is currently an assistant professor at King Mongkut’s University of Technology Thonburi. Suthep’s research interests are in the area of pumps and small hydroturbine. Manuspong Chamaoot received a B. S. degree, 1972 and M.S. degree in Mechanical Engineering, 1979 from the King Monkut’s University of Technology Thonburi. He is currently an assistant professor at King Monkut’s University of Technology Thonburi. His research interests are in the field of mechanical vibration for rotating equipment and computational fluid dynamics.     

Experimental and numerical studies on heat transfer enhancement for air conditioner condensers using a wavy fin with a rectangular winglet

Journal of Mechanical Science and Technology - The air side thermal performance of wavy fins with rectangular winglets are studied using experimental and numerical methods. The following parameters...