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This study aims to predict and to examine the springback of CP2 Titanium sheets in hydroforming with membrane diaphragm process, which is the branch of hydroforming process. The Hydroforming with Membrane Diaphragm was used for experimental investigation, in which specified CP2 titanium sheets were bent with various radii and angles on a specifically designed die. Springback results were then used to validate the finite element model constructed previously. Results show that the numerical model of this study can be used to predict the approximate springback values. Thus, the scrap quantities of the sheet metal titanium products can be reduced by making some modifications on the die, such as the springback compensation based on the obtained approximate springback values.

3D printing plays an important role in manufacturing of parts. Recent developments in 3D printing technology enable to print various shapes, sizes, and functional surfaces. The printed surfaces can have texture topology, which enables changing wetting state from hydrophilic to hydrophobic. This requires proper setting of printing parameters. In the present study, 3D printing of samples from titanium alloy (Ti-6Al-4V) is carried out. The resulting surface topology is examined using the analytical tools. The wetting state of 3D printed sample surfaces is assessed incorporating the contact angle method. The surface free energy of the printed samples is determined adopting the liquid contact angle technique. It is found that printed surfaces possess hydrophobic wetting state with droplet contact angle of 135° ± 5°. The droplet contact angle hysteresis is of the order of 36°, which causes pinning of the droplet on the surface. The surface free energy is determined as 54.2 mJ/m2. [ABSTRACT FROM AUTHOR]

Additive manufacturing of Ti6Al4V alloy film is considered and the morphological and metallurgical characteristics of the film are investigated. Analytical tools are used to characterise the printed alloy layer. The surface texture and microhardness of the layer are examined and the friction coefficient of the layer surface is assessed using the micro-tribometer. It is found that the alloy layer manufactured is free from large-scale asperities including micro-cracks and deep voids; however, few small pores sites are apparent on the surface because of the gasification and air release from the loose powders during the processing Microhardness of the top surface is higher than that of conventionally produced alloy surface. The friction coefficient of the surface remains lower than that of the conventional alloy surface. In the central region of the layer cross section, the columnar structures are developed and slanted grains are formed in the close region of the top and the bottom surface of the layer. [ABSTRACT FROM AUTHOR]

We investigated the protective effects of L. deliciosus and A. cylindracea supplementation against carbon tetrachloride (CCI4) induced oxidative stress by measuring levels of adenosine deaminase (ADA) and myeloperoxidase (MPO), and by observing histopathological changes in liver and kidney tissues of rats. We divided 36 rats into six groups: control, CCl4, L. deliciosus, A. cylindracea, CCl4 + L. deliciosus, and CCl4 + A. cylindracea. We found that administration of CCI4, A. cylindracea, and CCl4 + A. cylindracea increased MPO and ADA levels. We observed severe hepato-renal degenerative and necrotic lesions in the CCI4, A. cylindracea and CCl4 + A. cylindracea groups. Severe lesions of the liver and kidney were not observed with A. cylindracea administration. CCI4 induced hepato-renal lesions were ameliorated by L. deliciosus extract supplementation. L. deliciosus could be an important dietary antioxidant for preventing histologic lesions in liver and kidney due to CCI4 induced oxidative stress in rats. [ABSTRACT FROM AUTHOR]

The therapeutic potential and antioxidant capacity of Ferula elaeochytris extract (FE) in the liver, kidney and pancreas of rats with diabetes induced by streptozotocin (STZ) was assessed using biochemistry, histopathology and immunohistochemistry. Forty adult Wistar albino male rats were divided randomly into five groups of eight rats each. The normal control (NC) group was untreated. The diabetes control (DC) group was treated with STZ to induce diabetes. The diabetes + acarbose group (DAC) was treated with STZ, then with acarbose daily for 28 days. The diabetes + FE (DFE) group was treated with STZ, then FE daily for 28 days. DC rats had inflammatory cell infiltration, hydropic degeneration and necrosis, whereas the DFE rats exhibited nearly normal histology. Insulin immunostaining in the pancreatic beta cells was decreased in the DC group compared to the NC group, whereas the DFE group was similar to the NC group. Many serum biomarkers of damage to liver, kidneys or pancreas were elevated in the DC group compared to the NC group; these biomarkers were decreased in the DFE group. The DC group exhibited increased malondialdehyde levels and decreased levels of the antioxidant defense system constituents compared to the NC group. The level of biomarkers the DFE group was close to the NC group. FE exhibited a protective effect against tissue damage owing to its antioxidant activities and to its ability to effect regeneration of β-cells in STZ induced diabetic rats. [ABSTRACT FROM AUTHOR]

In the study 32 Wistar albino rats were divided into four group as control (Group Control, n=8), methotrexate (Group MTX, n=8), MTX + UDS (Group MTX+UDS, n=8) and Urtica dioica seed extract (UDS) (Group UDS, n=8). After the trial, blood and post-necropsy testicular tissue samples were taken. Histopathological examinations showed that methotrexate had an adverse impact on spermatogenesis by damaging testicles; however, such damages were substantially decreased in the Group MTX+UDS. In the immunohistochemical examinations glutathione peroxidase ' (GPx') immunoreactive areas was higher in the Group MTX + UDS compared to the Group MTX.Biochemical examinations revealed that the level of malondialdehyde (MDA), glutathione (GSH), glutathione S-transferase (GST) and catalase (CAT) enzymes levels statistically significantly differenced (p<0.001) in the Group MTX compared to the control, UDS and MTX+UDS groups. There were significant (p<0.05) differences the Group MTX from Group MTX+UDS. such as density, motility, dead-live sperm rate and abnormal sperm rate. Our study results showed that UDS prevented the damage occurred in the testicles according to histopathological, immunohistochemical, biochemical and spermatological findings. [ABSTRACT FROM AUTHOR]

Objective: This study aims to investigate the antioxidant properties and protective effects of Heracleum persicum (HP) extract in streptozotocin (STZ)-induced diabetic rats. Material and Methods: Forty-two Wistar albino male rats were divided into six groups including Control (C); Diabetes mellitus (DM); DM+Akarboz 20 mg/kg; DM+100 mg/kg HP extract (HP1); DM+200 mg/kg HP extract (HP2) and DM+400 mg/kg HP extract (HP3). Experimental diabetes was established by a single-dose [45 mg/kg, intra-peritoneal (i.p)] STZ injection. Essential dosages of HP extracts and Akarboz were applied with gastric gavage for 21 day. Results: In histopathological evaluation of the stained liver and kidney sections of diabetic rats showed degeneration and necrosis of hepatocytes, inflammatory cell infiltration and hydropic degeneration and necrosis in tubulus epithelial cells, disorder of glomerular structure and lymphocyte infiltration. These histopathological changes were ameliorated in the HP-treated rats depending on the dose level. Glutathione peroxidase 1 (GPx-1) immunoreactivity was detected in hepatocytes of liver and tubule epithelial cells of kidney. We have shown that treatment with extracts of HP modulates GPx-1 expression in HP-treated rats. STZ-induced degenerative changes in beta-cells caused decreases in the number of functioning beta-cells and insulin immunoreactivity in the pancreas of the diabetic rats. The pancreas of HP-treated rats were improved and the number of immunoreactive ß cells were significantly increased. Conclusion: Our data suggests that the STZ-induced immunohistochemical and histopathological alterations could be prevented by HP extract probably due to possess the ability to regenerate ß-cells. [ABSTRACT FROM AUTHOR]

The existing policy frameworks surrounding the launch of man-made objects and expeditions into space are largely unequipped to deal with the long-term consequences of debris accumulation beyond the Earth's atmosphere. This has serious implications for all telecommunications satellites. As space-faring actors (who are increasingly from the private sector, in addition to government-affiliated) become more involved with these activities, fragmentation from a variety of sources (colloquially grouped as space debris) will only continue to proliferate before outright impeding the ability of humans to conduct operations in space altogether. This paper proposes, as a solution, the implementation of adaptive governance structures with regards to the issue of space debris. This solution takes place in the form of collaborative/flexible endeavors between the United Nations Office for Outer Space Affairs (UNOOSA), International Telecommunication Union (ITU), private sector spaceflight corporations, and governmental space agencies to mitigate space debris pileup. Through the usage of new technologies to spearhead space debris cleanup, non-partisan economic incentives, and clarification on acceptable environmental conditions for satellite launches, an adaptive governance model for handling space debris is key to making space safe for communication and research. • The accumulation of orbital space debris poses serious dangers to the long-term sustainability of communications. • The rate of space debris growth (and instances of debris impacting human-made objects) will be exponential over time. • There have already been efforts made to track, mitigate, and even remove debris, but most are accompanied by shortcomings. • The archaic, set-in-stone nature of traditional government policies can inhibit developments for addressing space debris. • Adaptive governance implementation is a feasible means of addressing space debris and preserving communications structures. [ABSTRACT FROM AUTHOR]

Laser cutting of large diameter hole in aluminum foam is carried out and morphological changes in the cutting section are examined using scanning electron microscopes, energy dispersive spectroscopy and X-ray diffraction. The thermal stress fields in the cutting section are computed in line with the experimental conditions. Finite element code is incorporated in the numerical simulations. It is found that the cut section is free from defects such as large size burrs and dross attachments. The thermal stress predicted is less than the yielding limit of the workpiece. The presence of air trapped within the pores prior to laser irradiation in the workpiece results in the formation of oxide compounds at the cut sections. [ABSTRACT FROM AUTHOR]

In the present study, laser cutting of 7050 aluminum alloy sheets reinforced with Al2O3 and B4C particles are carried out. The cut geometry is examined using scanning electron microscope and the optical microscope. The lump parameter analysis technique is used to formulate and determine the kerf width size. The predictions for kerf width are compared with experimental data. The percentage kerf width size variation along the cut edges is determined and the influence of the laser power level and duty cycle of the laser pulses on the percentage kerf width size variation is examined. It is found that 7050 aluminum alloy reinforced with 20% Al2O3 composite results in relatively large kerf width size as compared to its counter parts that corresponding to 7050 aluminum alloy reinforced with 20% B4C composite. The kerf width size predicted agreed with the experimental data for both composites. [ABSTRACT FROM AUTHOR]