Optimization of tribological properties in A356/10SiC/5Gr hybrid composite using Taguchi method

In present study, the tribological behavior of hybrid composites with A356 aluminum alloy matrix reinforced with 10 wt.% of SiC and 5 wt.% of graphite was investigated using the Taguchi method. The composites were produced by the compocasting procedure. The tribological properties were studied using block-on-disk tribometer under lubricated sliding conditions at different normal loads (40N, 80N and 120N), sliding speeds (0.25 m/s, 0.5 m/s and 1 m/s) and sliding distances (150 m, 300 m and 1200 m). Analysis of the wear rate results was performed using the ANOVA technique. The lowest level of wear rate corresponded to the contact conditions with normal load of 40N, sliding speed of 1.0 m/s and sliding distance of 1200 m

WEAR BEHAVIOUR OF HYBRID ZA27/SIC/GRAPHITE COMPOSITES UNDER DRY SLIDING CONDITIONS

The paper deals with tribological behaviour of hybrid composites based on ZA27 alloy reinforced with silicon-carbide (SiC) and graphite (Gr) particles. The tested sample contains 5% of SiC and 1% Gr particles. The experimental tests were performed on a “block-on-disc” tribometer. The main tribological parameter in the analysis was wear scar width, obtained by variation of normal loads and sliding speeds, under dry sliding conditions. Through observation of the changes in wear scar widths in dry sliding conditions, corresponding conclusions were made.Publishe

Robust stability of linear perturbed discrete systems with multiple time-delay

The paper presents some new sufficient conditions, independent of delay, for the asymptotic stability of a particular class of linear perturbed time-delay systems with multiple delays. The proposed criteria introduce a smaller number of assumptions and are expressed in more natural and simpler mathematical forms. Numerical results are presented to support and illustrate the derived results

Wear characteristics of hybrid composites based on ZA27 alloy reinforced with silicon carbide and graphite particles

Publishe

Subcutaneous and Intraosseous Fat Necrosis Associated with Chronic Pancreatitis

Background: Extra-abdominal manifestations of fat necrosis, like subcutaneous fat necrosis, polyarthritis, and polyserositis may appear with an occurrence rate of about 0.8%, wherein intraosseous fat necrosis is a more rare complication of pancreatitis, with few reports in English literature. Case report: A 34-year-old male with a 15-year-history of alcohol abuse was hospitalized several times in the last few years because of attacks of relapsed chronic pancreatitis. After the last attack, pancreatitis came in a stable state (“burned out”) with no symptoms and signs of the disease. The patient had been free of symptoms for 28 months since the last admission when he came with sub-febrile temperature, huge pain, swelling, and erythema in the area of the left lateral malleolar region with propagation in the foot. Blood biochemistry was normal. Conventional radiography showed multiple sites of osteolysis in the left calcaneus. Images on multislice computed tomography (MSCT) with 3D reconstruction revealed hypodense focuses that corresponded to osteonecrosis areas and bone marrow edema in the left calcaneus. Conclusions: The possibility of intraosseous fat necrosis should be considered in situations of unexplained polyarthritis or panniculitis, particularly in individuals with alcohol abuse or pancreatic disease

Isolated Spleen Metastases of Endometrial Cancer: A Case Report

Background: Isolated splenic metastases from endometrial cancer, which is a relatively common malignancy, are extremely rare findings; to date, only 14 cases have been reported in the literature. Case Summary: We report a patient with isolated splenic metastases of endometrial cancer 3 years after radical surgery of the primary tumor. The patient was successfully treated by splenectomy and six cycles of paclitaxel. Fifty months after splenectomy, she was alive and well, and with no evidence of disease. Conclusion: Isolated spleen metastasis of endometrial cancer is very rare. Radical surgery and adjuvant therapy may offer excellent long-term survival

Microbial profile of food contact surfaces in foodservice establishments

Purpose - The purpose of this paper is to investigate the microbial profile of food contact surfaces (FCS) in foodservice industry of Serbia. Design/methodology/approach - The research covered 21,485 samples collected from 1,085 foodservice establishments during a period of 43 months. Results were deployed in terms of food contact materials, types of FCS and types of foodservice establishments. Findings - Highest share of results = 2 log(10) CFU/cm(2) were present on plastic surfaces during Autumn, while on ceramic and stainless steel surfaces highest share were observed during the Summer season. Take-away food establishments had the highest share of results = 2 log(10) CFU/cm(2) for both stainless steel and plastic surfaces. Highest share of stainless steel surfaces with microbial load = 2 log(10) CFU/cm(2) were cutlery, dishes and knives. Plastic dishes had the highest share of results = 2 log(10) CFU/cm(2) while cutting boards had the majority of results between 1 log(10) CFU/cm(2) and 2 log(10) CFU/cm(2). Research limitations/implications - Limitations of the research stem from the discussion of the nature of the FCS like porosity and other physical characteristics. Practical implications-This research has a practical application in terms of establishing process hygiene levels depending on types of food contact materials and types of FCS and seasonal variations. Originality/value - The findings of this study are worthy, in respect to possible correlation between seasonal variation and process hygiene requirements and can facilitate a better understanding of microbial risks associated with food preparation