Surface Modification Inspired by Malayopython Reticulatus for Friction Control

This research is to study the frictional characteristics of a real Malayopython Reticulatus snake ventral scales and to evaluate its feasibility as an inspiration for surface modification designs. Two types of experiments were carried out at different sliding directions and surfaces to analyze the frictional characteristics of snake ventral scales. From this study, snakeskin demonstrates frictional anisotropy and it is prominent under wet condition. Based on these findings, surface designs inspired by snakeskin is suitable for parts or components that are subjected to directional friction especially in wet conditions

Laser-Assisted High Speed Machining of 316 Stainless Steel: The Effect of Water-Soluble Sago Starch Based Cutting Fluid on Surface Roughness and Tool Wear

Laser-assisted high speed milling is a subtractive machining method that employs a laser to thermally soften a difficult-to-cut material’s surface in order to enhance machinability at a high material removal rate with improved surface finish and tool life. However, this machining with high speed leads to high friction between workpiece and tool, and can result in high temperatures, impairing the surface quality. Use of conventional cutting fluid may not effectively control the heat generation. Besides, vegetable-based cutting fluids are invariably a major source of food insecurity of edible oils which is traditionally used as a staple food in many countries. Thus, the primary objective of this study is to experimentally investigate the effects of water-soluble sago starch-based cutting fluid on surface roughness and tool’s flank wear using response surface methodology (RSM) while machining of 316 stainless steel. In order to observe the comparison, the experiments with same machining parameters are conducted with conventional cutting fluid. The prepared water-soluble sago starch based cutting fluid showed excellent cooling and lubricating performance. Therefore, in comparison to the machining using conventional cutting fluid, a decrease of 48.23% in surface roughness and 38.41% in flank wear were noted using presented approach. Furthermore, using the extreme learning machine (ELM), the obtained data is modeled to predict surface roughness and flank wear and showed good agreement between observations and predictions

Friction measurement of modified PDMS surfaces inspired by Malayopython Reticulatus

The lack of limbs on snakes enables its ventral scales to be in almost constant contact with the substrate. Their skin is presumably adapted to generate high and low friction to slither. This frictional characteristics in snakes were hypothesized to be contributed by the be tooth-shaped or denticle-like microstructures found on the snake ventral scales. The frictional properties of the microstructures found on snake ventral scales was studied and its feasibility as an inspiration for surface modifications was observed. This study was carried out to analyze the frictional anisotropy exhibit by the snake ventral scale microstructures and also how it changes the frictional properties of the PDMS surface when the microstructures are replicated on to it. The PDMS embedded-elastomeric stamping method was used in this experiment to replicate the snake ventral scales onto the PDMS. Based on the data collected the microstructures on the snake ventral scales does exhibit frictional anisotropy. The PDMS with replicated snakeskin microstructures displays higher COF compared to PDMS with smooth surface. When sliding on most types of surfaces, the COF of real snakeskin and replicated snakeskin is higher if the surface is semi wet. Whereas for smooth PDMS the COF is lower when the surfaces are semi wet. Generally, from both experiments, when the replicated snakeskin is sliding on the surface in the lateral direction, it is observed that the COF is the lowest followed by the caudal then the rostral direction

Antibacterial Properties of Snakeskin Inspired PDMS Surfaces Layered with Poly-DL-Lactic Acid Nanosheet

The increment of sterilization resistant bacteria minimizes the effectiveness of disinfectants which leads researchers into studying other means in minimizing bacterial contamination on surfaces. Hence, this study plans to investigate surfaces with the ability to discourage bacterial adhesion and reduces the need for frequent sterilization. This study tested the feasibility of applying snakeskin inspired microstructures onto a polydimethylsiloxane (PDMS) surface to reduce bacterial adhesion and increase its antibacterial properties. In theory, the microstructure of snakeskin is smaller or about the same size as a bacterium making it unfeasible for bacterial adhesion. The embeddedelastomeric stamping method was used for the biomimicry of snakeskin onto PDMS surfaces. The replicated snakeskin and controlled (no microstructure) PDMS samples were layered with Poly-DL-lactic acid (PDLLA) nanosheet of different thickness. Then, the morphology of the surfaces was observed using a scanning electron microscope. The surface of the samples was tested with Staphylococcus aureus and Bacillus with compliance of the ISO 22196 standard to evaluate the antimicrobial activity. Our results revealed, surfaces with snakeskin microstructures displayed a 16% reduction in bacterial adhesion compared to flat PDMS. Whereas the presence of nanosheet does not significantly affect the adhesion of bacteria on the replicated snakeskin. These findings suggest that surfaces with the presence of snakeskin microstructures possess antibacterial property

L'EMBOLIE GRAISSEUSE, COMPLICATION TYPIQUE DES FRACTURES DE LA CEINTURE PELVIENNE ET DES MEMBRES INFERIEURS. PRESENTATION DE 5 PATIENTS

Five cases of fat embolism were recognized within 30 mth. Fat embolism is not a clinical entity but rather an aspect of the posttraumatic microembolism with a predominance in lipids. A therapeutic protocol is proposed comprising: heparin, lipostabil, rheomacrodex and albumin.SCOPUS: NotDefined.jinfo:eu-repo/semantics/publishe

L'EMBOLIE GRAISSEUSE, COMPLICATION TYPIQUE DES FRACTURES DE LA CEINTURE PELVIENNE ET DES MEMBRES INFERIEURS

SCOPUS: NotDefined.jinfo:eu-repo/semantics/publishe

LE TRAITEMENT DE LA CLAUDICATION INTERMITTENTE PAR REENTRAINEMENT PHYSIQUE DU PATIENT NON HOSPITALISE. EVALUATION DE SON EFFICACITE SUR UN GROUPE DE 40 MALADES

The treatment of intermittent claudication by physical re-training of a patient with lower limb arteriopathy is not new (Alpert 1969, Cachovan 1976, Kindler 1965, Schoop 1964). It gives an effective improvement of walking distance and of physical performance capacity. Most programs used need the patient to be kept in a hospital and thus entail a significant social cost. We have set up a program for the retraining of patients that are not hospitalized and have checked the short and long term action achieved. The walking distance, the maximum performance in specific exercises, the walking exercises on a tread mill, are studied during the X 133clearance. The total leg blood flow before and after an arterial occlusive hyperhemic test is studied simultaneously.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

ARTERIOPATHIE PAR INTOXICATION A L'ERGOT. A PROPS D'UN CAS. REVUE DE LA LITTERATURE

SCOPUS: NotDefined.jinfo:eu-repo/semantics/publishe

COMPLICATIONS VASCULAIRES DANS UN CAS D'ANEMIE HEMOLYTIQUE PAR DEFICIT EN PYRUVATE KINASE

SCOPUS: ar.jinfo:eu-repo/semantics/publishe