Fatigue performance of thermal spray coatings on carbon steel: a review

This paper contributes to a review of the research of the fatigue behaviour of thermal spray coatings on carbon steel. Previous studies provide the experimental characterization of the fatigue resistance of coated carbon steel. Different coating powders were deposited to a different type of carbon steels. Also, S-N curves were drawn from axial- and rotating bending fatigue test to determine the fatigue strength or fatigue limit of the samples. Thermal spray coatings showed great improvement to the work hardening effect but worsen the fatigue life due to the inclusion of oxide and pores, the presence of stress concentrators, and high microcrack density. Moreover, the effects of the surrounding environment have also resulted in pros and cons towards the fatigue strength. An improvement, however, can be done with the shot peening treatment, which significantly increases the compressive residual stress at interfaces of coating/substrate. The high compressive residual stress could delay the crack nucleation, thus increasing the fatigue life of the coated part

Effect of powdered seed of Nigella sativa administration on sub-chronic and chronic lead acetate induced hemato-biochemical and histopathological changes in Sprague Dawley rats

Lead acetate (PbAC) toxicity can occur by either ingestion or inhalation from contaminated surfaces or from the environment. Nigella sativa is a natural product with immense pharmacological properties, which include antioxidant, antibacterial, and antianemia properties. It has been showed to counter the effect of PbAC-induced hematological and biochemical changes in short-term studies. This study hypothesized that the N. sativa (NS) administration will ameliorate the deleterious effects of chronic PbAC toxicity in rats. A total of 75 Sprague Dawley rats were divided into three groups of 25 rats, and each group was further sub-divided into five groups of five rats each. Group 1 rats (negative control) were given distilled water, group 2 (positive control; PC) were given 10 mg/kg of lead acetate (PbAC) daily, and groups 3 (T1), 4 (T2), and 5 (T3) were each given 10 mg/kg of PbAC followed by graded concentrations of powdered seeds of NS; 100, 150, and 200 mg/kg, respectively. Five rats in each group were euthanized at 30, 60, and 90 days for collection of whole blood and selected organs. Whole blood was collected after euthanized via cardio puncture and used to evaluate the complete blood profile, while plasma was used for biochemical analysis. Tissue samples of the liver and kidney were fixed with 10% buffered formalin, processed, and stained with H&E and periodic acid–Schiff (PAS) for the liver. Aggression and fear were increased in the PbAC-exposed group and absent in the T3 group. There was a lower (p < 0.05) red blood cell count (RBC), packed cell volume (PCV), mean corpuscular hemoglobin concentration (MCHC), and lymphocyte count in the PC and T1 groups only. Biochemical analysis revealed elevated (p < 0.05) liver enzyme and creatinine levels in the PC and T1 groups on day 90 for AST and day 30 for ALT and creatinine. The level of alkaline phosphatase (ALP) was higher (p < 0.05) in the PC at 30 and 60 days of sampling. Other parameters, such as WBCs, prothrombin, urea, and cholesterol, were not significant in all groups. Histopathological lesions in the liver and kidneys were more severe in the PC and T1 groups, while the T2 and T3 groups showed mild lesions resulting from N. sativa administration. There was a decrease (p < 0.05) in the total PAS-stained area signifying glycogen depletion in the PC, T1, and T2 groups at 60 days and a higher distribution of the PAS-stained areas (p < 0.05) in the T3 group. At 90 days, the PC group had a lower (p < 0.05) distribution of PAS-stained areas in comparison to the other groups. The results showed the therapeutic potential of N. sativa extract in modulating both hematological and biochemical alterations induced by chronic lead acetate administration in rats

Zingiber zerumbet (L.) Smith: A Review of Its Ethnomedicinal, Chemical, and Pharmacological Uses

Zingiber zerumbet Sm., locally known to the Malay as “Lempoyang,” is a perennial herb found in many tropical countries, including Malaysia. The rhizomes of Z. zerumbet, particularly, have been regularly used as food flavouring and appetizer in various Malays' cuisines while the rhizomes extracts have been used in Malay traditional medicine to treat various types of ailments (e.g., inflammatory- and pain-mediated diseases, worm infestation and diarrhea). Research carried out using different in vitro and in vivo assays of biological evaluation support most of these claims. The active pharmacological component of Z. zerumbet rhizomes most widely studied is zerumbone. This paper presents the botany, traditional uses, chemistry, and pharmacology of this medicinal plant

Bidirectional Antenna for 2.4-ghz WLAN Application Inside Train

In this paper, a bidirectional antenna is presented for a WLAN application inside monorail train. The Yagi Uda antenna has directional characteristic that is suitable for the long path service area. The design concept of the proposed antenna has two directional antennas combined pointed in opposite direction which only involves the driven element and directors. The Yagi Uda design of bidirectional antenna operates in the frequency band of 2.4 GHz. The antenna is proposed with a thickness of 1.6mm and relative permittivity of 4.3 on FR4 substratum. Resonant frequency is set at 2.42 GHz with a bandwidth of 390 MHz from simulation work. The proposed antenna also met the estimated antenna bandwidth at a range of 2.23 GHz-2.63 GHz, and the bidirectional pattern. Both simulated and measured result are well matched

Selection of a high yielding soybean variety, Binasoybean-2 from collected germplasm

More than two hundred soybean germplasm collected from local and exotic sources were put into evaluation to select desirable ones for directly use as varieties or for future usage as breeding materials. Through observation trials thirteen germplasm were selected considering their better agronomic performance. Selected germplasm were evaluated through different trials at soybean growing areas of Bangladesh during 2007 to 2010. The germplasm, BAU-S/109 produced significantly higher seed yield than control varieties Sohag and BARIsoybean-5 in most of the trials. Over three years trial, BAU-S/109 produced mean seed yield of 2711 kg ha-1 while Sohag and BARIsoybean-5 produced 2224 and 2227 kg ha-1 seed yield, respectively. BAU-S/109 also produced the higher number of branches and pods plant-1 along with higher 100-seed weight. Results of yield trials indicated that BAU-S/109 was suitable for cultivation in Bangladesh. BAU-S/80 was found to be moderately tolerant to soybean yellow mosaic virus and also showed lower insect infestation than control varieties. On the basis of better performance, Bangladesh Institute of Nuclear Agriculture (BINA) applied for registration of BAU-S/109 to the National Seed Board (NSB) of Bangladesh. Consequently, the NSB of Bangladesh registered BAU-S/109 as an improved soybean variety in 2011 as Binasoybean-2 for commercial cultivation

Circle grid fractal plate as a turbulent generator for premixed flame: an overview

This review paper focuses to ascertain a new approach in turbulence generation on the structure of premixed flames and external combustion using a fractal grid pattern. This review paper discusses the relationship between fractal pattern and turbulence flow. Many researchers have explored the fractal pattern as a new concept of turbulence generators, but researchers rarely study fractal turbulence generators on the structure premixed flame. The turbulent flow field characteristics have been studied tand investigated in a premixed combustion application. In terms of turbulence intensity, most researchers used fractal grid that can be tailored so that they can design the characteristic needed in premixed flame. This approach makes it extremely difficult to determine the exact turbulent burning velocity on the velocity fluctuation of the flow. The decision to carry out additional research on the effect circle grid fractal plate as a turbulent generator for premixed flame should depends on the blockage ratio and fractal pattern of the grid. 1

Enhanced Performance of DTC-DSC of Induction Machine utilizing 3-Level Cascade H-Bridge Multilevel Inverter

The paper presents a new 3L DTC-DSC scheme for induction motor driver by selecting proper voltage vector for medium and high application. In conventional 3L DTC two different voltage vectors are assigned to vary flux for low speed, medium speed and high speed applications. This paper purposes a scheme for low speed operation of induction machines by using the same technique as conventional 3L DTC. However for a high speed operation, only a single voltage vector is applied thus resulting dodecagon flux locus.The new scheme also improves the torque capabalities and the dynamic of torque performances