Sizing Cracks in Power Plant Components Using Array Based Ultrasonic Techniques

New techniques developed using the array transducer, to image and size the bottom-surface and near-through-wall crack-like defects in thick carbon steel components are discussed. Three studies are reported here including (a) Optimal beam steering angle for focused and unfocused inspection using phased array method for bottom-surface crack sizing. (b) A front wall correction algorithm for sizing of near-through-wall crack-like defects. (c) A small aperture technique for sizing of near-through-wall crack-like defects. A Finite Difference Time Domain (FDTD) based simulation was used to study and verify the experimental observations. The application of time domain scheme relative arrival time technique (RATT), to measure the size of the near-through wall crack-like defects for the leak before break (LBB) criterion, was also investigated and found to be insufficient. A conventional SAFT algorithm was used for improving the sizing using the small aperture technique.     

Investigations on the thermal effects in non-circular journal bearings

A comparative study based on the thermal performance of elliptical and offset-halves journal bearings has been carried out by solving energy equation while assuming Parabolic Temperature Profile Approximation across the fluid film for faster computation of temperatures. Investigation for the rise in oil film temperatures, thermal pressures, load capacity, and power loss for three commercially available grade oils have been carried out for bearing configurations under study. It has been found that the offset-halves journal bearing runs cooler when compared with elliptical journal bearing profile with minimum power loss and good load capacity using Oil 2 as lubricant for which minimum thermal degradation has been observed.     

Versatility of Radio Frequency Identification (RFID) Tags in the Pharmaceutical Industry

Abstract

Radio Frequency Identification (RFID) technology can be applied to a number of pharmaceutical processes, as ample of information can be stored and read rapidly from an RFID tag. Applications may range from inventory control, to access control, to telemedicine, to supply chain management and, most importantly, in combatting counterfeit products. Overall health care services can be improved by using this technology. This technology is gaining popularity in various fields, but is still costly and regulatory considerations are restricting its use. This paper explains the basics of RFID technology and some potential applications related to the pharmaceutical industry.     

Development of ANN model and study the effect of temperature on strain ratio and sensitivity index of EDD steel

Anisotropy and strain rate sensitivity index (m) plays a very important role in the formability of materials. In the present investigation strain ratios in 0°, 45° and 90° to the rolling direction and the strain rate sensitivity index were calculated at different temperatures. After developing the data from experiments, Artificial Neural Network (ANN) models are trained for different properties. Trained ANN models are used to calculate different strain ratios and sensitivity index at unknown temperatures. The results are promising and the percentage error in ANN prediction is found to be around 10%.     

Enhanced Mechanical Properties and Corrosion Behavior of Biodegradable Mg-Zn/HA Composite

Metallurgical and Materials Transactions A - Magnesium (Mg) and its alloys have shown potential for use in the biomedical industry due to their excellent biological performance and biodegradability...     

Reuse potential of municipal wastewater treatment facility effluents for sustainable water resource management in Ulsan,Korea

Effluent qualities of five municipal wastewater treatment facilities (MWWTFs) in Ulsan were evaluated to examine their reuse potential. Effluent from Yongyeon (Y) MWWTF, Onsan (O) MWWTF and Bangeojin (B) MWWTFs can be used as cooling water without further treatment. As evident from Langelier saturation index and Ryzner index values, reuse of treated effluent from OMWWTF and BMWWTFs is recommended by controlling the pH to reduce the scale-forming potential of effluent. However, effluents from these MWWTFs need additional treatment to remove residual dissolved constituents before reuse as boiler water. Besides, effluent from Hoiya (H) MWWTF and Unyang (U) MWWTFs can be reused for agricultural irrigation without any additional treatment. Based on the scientific results obtained from this investigation, proper application of technology and promotion of public awareness to change the traditional mindset for treated effluent reuse could immensely contribute towards conserving local water resources and addressing global environmental problems on a regional basis.     

Cold Model Investigations of Melting of Ice in a Gas-Stirred Vessel

The melting of steel scrap in high temperature liquid iron melt is investigated by conducting cold model experiments of the melting of ice sample of different geometries and sizes in an argon-stirred vessel containing water. The melting process of ice samples is observed using a high-speed camera. Design of experiments is based on similarity criteria. The relationships between non-dimensional groups related to heat transfer (Nu, Re, Pr, and Gr) are derived for different experimental conditions. The results are compared with those reported in the literature. The heat transfer coefficient is estimated as a function of mixing power and is found to be in good agreement with the calculated values obtained by using reported relationships in literature.     

Preparation and electrical properties of xCaRuO3/(1 − x)CaTiO3 perovskite composites

CaRuO₃-CaTiO₃ ceramic composites were prepared by sintering for short times for potential applications in the areas of electronic ceramics. Scanning electron microscopy and energy dispersive X-ray analysis showed two separate phases, CaRuO₃ and CaTiO₃ in the composite. Conductivity data, measured by the four-probe method, showed that the composites have high electrical conductivity when x ≥ 0.19 in xCaRuO₃-(1 − x)CaTiO₃ composites. Furthermore, the nanoparticle of calcium ruthenate prepared by reverse micelle synthesis was used to be conductive agent for the composite. The result shows that the use of nano-sized calcium ruthenate enabled higher electrical conductivity to be maintained down to x = 0.09.     

机械手式抛丸系统在发动机缸体清理中的应用

1．缸体的内部清理 水冷发动机的气缸体和上曲轴箱常铸成一体。气缸体一般用灰铸铁铸成，其上部的圆柱形空腔称为气缸，下半部为支承曲轴的曲轴箱，其内腔为曲轴运动的空间。在气缸体内部铸有许多加强筋，冷却水套和润滑油道等。     

Application of electromagnetic impact technique for welding copper-to-stainless steel sheets

The ability to manufacture a product using different metal combinations greatly increases flexibility in design and production. Joining of dissimilar metal combinations like Copper-to-Stainless Steel (Cu-to-SS) is, however, a challenging task owing to the large differences in physical and chemical properties. The application of electromagnetic (EM) impact technique is demonstrated for welding copper (Cu) to stainless steel (SS) sheets. The welding Cu-to-SS is accomplished by using Al drivers to accelerate Cu and SS work sheets. The tensile shear strength test and the metallographic studies are carried out for Cu-to-SS EM welds.