Multi-objective optimization framework complying IEEE 802.15.6 communication standards for wireless body area networks

Wireless Networks - Wireless body area network (WBAN) routing protocols are primarily designed for improvement of network performance parameters such as network lifetime, throughput and latency....     

Fracture and flexural characterization of SiCw/SiC composites at room and elevated temperatures

The fracture and flexural behaviour of monolithic SiC and SiC-whisker reinforced SiC composites (SiC_w/SiC) has been investigated at room and elevated temperatures. Flexure and fracture tests were conducted in a four-point beam configuration at 23 °C, 800 °C and 1200 °C to study the effects of whisker reinforcements especially in respect of mechanical and thermal stability at high energy environments. Flexural strengths and fracture toughness data within the test temperature range are presented in graphical as well as in Weibull form, and experimental observations are analysed and discussed. Increase in flexural strength as well as in fracture toughness has been observed with the whisker reinforcement. However, it was found that the trend discontinues after a certain range of temperature. Post-failure analyses have been performed with the scanning electron microscope (SEM). Formation of glass phase has been observed at the whisker/matrix interface and the crack growth was found to be shifting from intergranular to transgranular with the rise in temperature. Effects of whisker reinforcement and the degradation of flexural and fracture properties at elevated temperature are investigated. Ultrasonic velocity measurements have been performed through the thickness of the untested as well as fractured specimen, and the variation in the sonic wave velocity is discussed in this paper.     

Hygrothermal influence on the interlaminar shear strength of Kevlar-graphite/epoxy hybrid composites

The hygrothermal influence on the interlaminar shear strength of Kevlar 49-graphite/epoxy hybrid composite was investigated in the temperature range –50 to 150 ° C. Moisture was introduced into the specimen by immersion in distilled water until a specified weight gain occurred. Two material lay-up were used in this investigation. In Kev 49/T-300/Kev 49, Kevlar 49 and graphite prepreg tapes were used as outer and centre layer, respectively and in T-300/Kev 49/T-300, it was vice versa. In both cases the tapes were alternated until the total thickness was achieved. The results show that interlaminar shear strength change with the ply sequence of hybrid laminates. The interlaminar shear strength of T-300/Kev 49/T-300 is relatively higher than that of Kev 49/T-300/Kev 49. The interlaminar shear strength of both T-300/Kev 49/T-300 and Kev 49/T-300/Kev 49 decrease with the increase of temperature in the range –50 to 150 ° C. The addition of moisture further degrade the interlaminar shear strength in the same temperature range. Close physical observation showed clear evidence of interlaminar shear failure for most of the specimens.     

FEELS: fuzzy based energy efficient and low SAR routing protocol for wireless body area networks

Wireless Networks - A patient's body gets exposed to RF radiation due to node data transmissions in a Wireless Body Area Network (WBAN). Therefore, in addition to energy efficiency, the adverse...     

The effects of alcohol and tobacco use on troop readiness

Prior studies have documented the ill effects of cigarette smoking on soldier athletic performance. We examined the effects, if any, of cigarette smoking and alcohol use on troop readiness. A group of 510 soldiers was examined. They answered an initial questionnaire and then were followed in sick call for a 2-month period. The results of the study confirmed that cigarette smoking impacted adversely on athletic performance. However, we were unable to quantitate increased time off or away from duty as a result of cigarette smoking and alcohol use.     

Variability of the midfacial muscles: analysis of 50 hemifacial cadaver dissections

The region of the midface represents a challenging area to both reconstructive and aesthetic surgeons. An anatomic study was performed that attempted to identify patterns and variations of the muscular anatomy. The goals of this study were twofold: to identify patterns and variability of the midfacial muscles that might impact on reconstructive efforts and to attempt to correlate this anatomy with features of the overlying soft tissues, specifically the nasolabial crease. Fifty hemifacial cadaver dissections were performed. The information collected was assembled into a large data base, and statistical significance was analyzed using Fisher's exact probability test. Results demonstrated that, although a great degree of variability exists with respect to the midfacial muscles, seven distinct patterns of these muscles did emerge. The most common pattern was the presence of a levator alae nasi, levator labii superioris, and zygomaticus major, which occurred in 44 percent of specimens. Specimens that possessed a risorius, zygomaticus minor, or both, were relatively uncommon. The consistent presence of the levators suggests adding a superior vector to recreate a smile in facial reanimation surgery. Two important anatomic variations were noted. A bifid zygomaticus major was found to be present in 34 percent of individuals. Because the inferior bundle had a dermocutaneous insertion, this anomaly may represent the anatomic correlate of a cheek "dimple." A second anomaly noted was the lateral cheek crease, which appeared to be associated with a cutaneous attachment from the underlying platysma muscle. However, no correlation could be found for facial muscle pattern and the overlying nasolabial crease structure. This lack of correlation may indicate that the facial muscles alone do not dictate the structure of the nasolabial crease and that other dynamic factors are involved in determining this feature of the aging face.     

Relative maxillary retrusion as a natural consequence of aging: combining skeletal and soft-tissue changes into an integrated model of midfacial aging

Depletion of intracellular calcium stores by agonist stimulation is coupled to calcium influx across the plasma membrane, a process termed capacitative calcium entry. Capacitative calcium entry was examined in cultured guinea pig enteric glial cells exposed to endothelin 3. Endothelin 3 (10 nM) caused mobilization of intracellular calcium stores followed by influx of extracellular calcium. This capacitative calcium influx was inhibited by Ni2+ (89 +/- 2%) and by La3+ (78 +/- 2%) but was not affected by L-, N-, or P-type calcium channel blockers. Chelerythrine, a specific antagonist of protein kinase C, dose-dependently inhibited capacitative calcium entry. The nitric oxide synthase inhibitor NG-nitro-L-arginine decreased calcium influx in a dose-dependent manner. The combination of chelerythrine and NG-nitro-L-arginine produced synergistic inhibitory effects. Capacitative calcium entry occurs in enteric glial cells via lanthanum-inhibitable channels through a process regulated by protein kinase C and nitric oxide.