Adaptation of Cardinal Points Symmetry Landmarks Distribution Model to in-vivo B-Mode Ultrasound Images of Transverse Cross-section of Carotid Arteries

The geometry of the imaged transverse cross-section of carotid arteries in in-vivo B-mode ultrasound images are most times irregular, unsymmetrical, full of speckles and usually non-uniform. We had earlier developed a technique of cardinal point symmetry landmark distribution model (CPS-LDM) to completely characterize the Region of Interest (ROI) of the geometric shape of thick-walled simulated B-mode ultrasound images of carotid artery imaged in the transverse plane, but this was based on the symmetric property of the image. In this paper, this developed technique was applied to completely characterize the region of interest of the geometric shape of in-vivo B-mode ultrasound images of non-uniform carotid artery imaged in the transverse plane. In order to adapt the CPS-LD Model to the in-vivo carotid artery images, the single VS-VS vertical symmetry line common to the four ROIs of the symmetric image is replaced with each ROI having its own VS-VS vertical symmetry line. This adjustment enables the in-vivo carotid artery images possess symmetric properties, hence, ensuring that all mathematical operations of the CPS-LD Model are conveniently applied to them. This adaptability was observed to work well in segmenting the in-vivo carotid artery images. This paper shows the adaptive ability of the developed CPS-LD Model to successfully annotate and segment in-vivo B-mode ultrasound images of carotid arteries in the transverse cross-sectional plane either they are symmetrical or unsymmetrical.

Thermomechanical Analysis of Friction Stir Welding by Using a New Velocity-Based Model for Tool-Workpiece Interaction

The friction stir spot welding test was designed to measure the coefficient of friction on the tool-workpiece contact interface under different tool rotation speeds. The boundary velocity of the workpiece material was calculated based on the stress state of the material on the contact interface. An integrated computational fluid dynamics (CFD) model of friction stir welding (FSW) was established based on the matrix's coefficient of friction and boundary velocity to simulate heat and mass transfer. A more realistic boundary velocity distribution was acquired. A method was introduced to predict strain along a streamline by integrating the strain rate along with the streamline's reverse. The nephogram of strain on the transverse cross-section of weldment displays that strain at the advancing side (AS) is more significant than that at the retreating side (RS), and strain increases as the distance from the shoulder surface decrease. Strain in some regions can be tremendous if the material flows through the rotation flow zone. Wall heat flux on tool-workpiece contact interface at RS is more significant than that at AS. The maximum temperature was observed at the front part of RS. The model is validated since the predicted temperature profile agrees well with corresponding experimental results.

Characterization of activated charcoal microstructure porosity of cashewnut shell (Anacardium occidentale L.)

Cashew nut (Anacardium occidentale L.) shell is abundantly available as waste from chasew nut processing industries. Cashew nut shell is potentially used for activated charcoal. This paper characterize the porosity microstructure of activated charcoal made from cashew nut shells which is physically activated at various activation temperatures. Initially, cashew nut shells were collected and carbonized at 500°C for 3 hours. Then, the charcoal was activated at 800°C and 1000°C for 60 minutes. The characterization of microstructure porosity of cashew nut shell activated charcoal at transverse cross-section was carried out at 500 times magnification of 10 kV Scanning Electron Microscope (SEM) using a grain-shaped test sample. Observation of the porosity formed on the sample surface included pore size and frequency. Observation data were arranged in tabulated form and analyzed descriptively. The results showed that the frequency of pores in charcoal activated at 1000°C tended to be higher than that of charcoal activated at 800°C. The higher activation temperature increased the pore diameter of the charcoal and decreased the clogging residue. Keywords: mesoporous, pyrolysis, hydrocarbon

Effects of CNTs addition on the microstructure and microhardness of stainless steel alloy/carbon-manganese non-alloyed steel welding

In recent years some progress has been made about the addition of Carbon Nanotubes (CNTs) in the stainless steel metal matrix by pulsed Gas Tungsten Arc Welding (P-GTAW). Despite that, there is lack of information regarding to microstructural modifications induced by CNTs in dissimilar welding. In this sense, we present the welding of nanocomposite based on Nickel/Carbon Nanotubes-stainless steel 316L alloy (Ni/CNTs-SS 316L), as the welding metal, on carbon-manganese (C-Mn) non-alloyed structural steel, as the base metal. The microstructure of manufactured specimens with/without nanocomposite was characterized by: optical microscopy; Raman spectroscopy; scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) and electron backscattering diffraction (EBSD). Moreover, Vickers tests were performed from the welding metal (WM) to the base metal (BM) before/after temper treatment in order to investigate the microhardness changes. The results show that dilution rate and grain size for specimen with nanocomposite was higher than without nanocomposite; the CNTs affected the misorientation angle and texture of the WM; the topside microhardness from WM with Ni-CNTs was on average 30.40% higher than BM; and, in transverse cross-section microhardness was 31% higher than control sample on average at fusion line zone. These results indicate that addition of CNTs in the metallic matrix by dissimilar welding is a fertile ground for new studies applicable to manufacturing industry.

The Effect of Top Surface Lubrication on the Friction Stir Welding of Polycarbonate Sheets

In this work, top surface lubrication during friction stir welding of polycarbonate sheets was applied. A homogenous layer of Paraffin wax has been placed on the top surface of the joint area with a width that ensures to cover the shoulder diameter. Then FSW was applied using conventional FSW tool with rotating pin and shoulder at different FSW parameters (Rotation speeds of 1 000, 1500, 2 000 min–1 and welding speeds of 25, 50, 75,100 mm/min). The main objective of using the wax is to act as a lubricant that reduces the friction between the shoulder and the polycarbonate surface. The joints produced were investigated in terms of surface quality, internal defects, and mechanical properties. During FSW the wax is melted and played as lubricant between the tool shoulder and the polycarbonate surface and resulted in defect-free surface with no thickness reduction of the original plate. The transverse cross-section showed defect-free joints for the majority of the FSW parameters investigated. Tensile testing results showed a reduction of the tensile strength after FSW, and an enhancement in the tensile strength with the increase of welding speed or rotation speed. The fracture occurs at the joint zone and the fracture surface investigation using SEM showed the existence of spherulitic structure in the weld joint.

Dissimilar Friction Stir Welding of AA2024 and AISI 1018: Microstructure and Mechanical Properties

This study investigated the effect of the friction stir welding rotation rate and welding speed on the quality and properties of the dissimilar joints between aluminum and carbon steel. Plates of 4 mm thickness from both AA2024 and AISI 1018 were successfully friction stir butt welded at rotation speeds of 200, 250, and 300 rpm and welding speeds of 25, 50, and 75 mm/min. The joint quality was investigated along the top surface and the transverse cross-sections. Further investigation using scanning electron microscopy was conducted to assess the intermetallic layers and the grain refining in the stir zone. The mechanical properties were investigated using tensile testing for two samples for each weld that wire cut perpendicular to the welding direction and the hardness profiles were obtained along the transverse cross-section. Both the top surface and the transverse cross-section macrographs indicated defect free joints at a rotation rate of 250 rpm with the different welding speeds. The intermetallic compounds (IMCs) formation was significantly affected by the heat input, where there is no formation of IMCs at the Al/steel interfaces when higher traverse speed (75 mm/min) or lower rotation speed (200 rpm) were used, which gave the maximum tensile strength of about 230 MPa at the low rotation speed (200 rpm) along with 3.2% elongation. This is attributed to the low amount of heat input (22.32 J/mm) experienced. At the low traverse speed (25 mm/min and 250 rpm), a continuous layer of Al-rich IMCs FeAl3 is formed at the joint interface due to the high heat input experienced (79.5 J/mm). The formation of the IMCs facilitates fracture and reduced the tensile strength of the joint to about 98 MPa. The fracture mechanism was found to be of mixed mode and characterized by a cleavage pattern and dimples. The hardness profiles indicated a reduction in the hardness at the aluminum side and an increase at the steel side.

Sanitary Gravity Sewer Design using Sewer GEMS Software Connect Edition for Utsav Vihar, Karala

The paper presents modeling, design and analysis of sewage network of Utsav Vihar by means of SewerGEMS software which helps in the achievement of project results in a shorter period of time in an effective way and at reasonable prices. In the present study the sewerage was designed for Utsav Vihar area in North – West Delhi District. SewerGEMS software eases the designing for engineers because of unique features to offer a fully dynamic and multi-platform sanitary and combined sewer modeling solution which otherwise tends to consume a lot of time and energy. The software uses derived equations and theorems for calculating the hydraulic model. It enables engineers to analyze all sanitary and combined sewer networks in a single package. The hydraulic design section includes the calculation and determination of the transit, total flow and hydraulic modeling for network pipes diameters or slopes. The application generates reports, layouts, longitudinal or transverse cross section.

Density Distribution in Wood of European Birch (Betula pendula Roth.)

The aim of the presented research is to perform a comprehensive analysis of wood density variability on the longitudinal and transverse cross-section of log trees at the age of 70 to 72 years of Betula pendula Roth. and the creation of density distribution maps. Furthermore, the determination proportion of juvenile and mature wood was done. Wood density was determined with a non-destructive method using an isotopic densimeter. It was found that the wood location, both in cross-section and longitudinal section of the trunk, had a statistically significant effect on the average density of birch wood. The average density of whole logs was significantly higher than the average density at the breast height. On the cross-section, the distribution of average densities determined at the breast height, as well as on ¼ of the log height, properly depicted the distribution of average densities on the cross-section determined for the whole logs. The geographical direction (north–south) did not have a statistically significant effect on the distribution of average densities on the cross-section of the tested birch logs.