The influence of the collagen fibre network of muscle on the compliance and tensile strength of muscle samples subjected to loads at right angles to the muscle fibre axis

The pattern of subdivision of a muscle into fibre bundles by the perimysium was examined as a possible source of within sample variability of meat toughness attributable to the connective tissue component. It was shown that the pattern of subdivision into fibre bundles relates to the tendom surfaces and influences the compliance and toughness of a meat sample. In addition it was shown that greater plasticity of raw meat samples results in greater compliance under load. The procedure of defining sample orientation relative to the geometry of the component parts enables some of the within sample variability to be explained and controlled.     

Muscle composition and fatty acid profile in lambs fattened in drylot or pasture

The effects of two fattening systems on muscle composition and fatty acid profile were determined in an experiment using samples of the longissimus dorsi (LD) muscle of 24 ram lambs (slaughter weight 29–31 kg). The fattening systems were: (i) drylot (a mixture of maize, soybean, wheat and minerals) and (ii) grazing (Cynodon dactylon). The lambs fattened in the drylot system presented higher fat levels (p<0.01), but lower concentrations of moisture (p<0.01) and cholesterol (p<0.05). The lipid content presented a negative correlation with moisture and protein. In lambs fattened in the drylot system increasing levels of fatness of LD muscle were associated with a decrease (p<0.05) in myristic and palmitic acids, but myristic, palmitic and linoleic acids increased (p<0.05) as the cholesterol levels of the muscles increased.     

CMOS-compatible optical rib waveguides defined by local oxidation of silicon

The local oxidation of silicon process is shown to be an effective means of defining optical rib waveguides in silicon on insulator while maintaining the surface planarity required for CMOS integration. Experimental waveguides have shown singlemode operation and losses of less than 1 dB/cm in the telecommunications band around 1550 nm     

Close-spaced fused fibre wavelength division multiplexers with very low polarisation sensitivity

The authors describe the fabrication of high performance narrowband fused fibre wavelength multiplexers. A twisting technique is employed to reduce the polarisation sensitivity. Unlike other polarisation quenching methods, twisting maintains the intrinsically good temperature stability of the device. The twisting mechanism has been studied theoretically using a model with a realistic coupler cross-section.<>     

投射光线

luminus Devices公司的工程师们测试高亮度LED,它们可照亮舞台、屏幕、商店和街道.作者:Martin Rowe, Senior Technical Editor Test & Measurement World 美国马萨诸塞州比尔里卡一当照明设计师Kevin Adams为Green Day在百老汇上演的音乐剧<美国白痴>(American Idiot)设计照明时,他想用白光照亮舞台.     

Air-water exchange of polychlorinated biphenyls in the Delaware River

The air-water exchange of polychlorinated biphenyls (PCBs) often results in net volatilization, which is thought to be the most important loss process for PCBs in many systems. Previous investigations of the air-water exchange of PCBs have been hampered by difficulties in treatment of the uncertainty in the calculation of air/water fugacity ratios. This work presents a new framework for the treatment of uncertainty, where uncertainty in physical constants is handled differently from random measurement uncertainty associated with random samples, and it further investigates the sorption of PCBs to colloids (dissolved organic carbon). Simultaneous measurements of PCBs in the air and water of five water quality management zones of the Delaware River were taken in 2002 in support of the total maximum daily load (TMDL) process. Gas-phase concentrations of IPCBs ranged from 110 to 1350 pg m(-3), while dissolved water concentrations were between 420 and 1650 pg L(-1). Shallow slopes of log Koc vs. log Kow plots indicated a colloidal contribution to the apparent dissolved-phase concentrations, such that a three-phase partitioning model was applied. Fugacity ratios for individual congeners were calculated under the most conservative assumptions, and their values (log-transformed) were examined via a single-sample T-test to determine whether they were significantly less than 1 at the 95% confidence level. This method demonstrated that air-water exchange resulted in net volatilization in all zones over all cruises for all but seven high molecular weight congeners. Calculated net fluxes ranged from +360 to +3000 ng m(-2) d(-1) for sigma PCBs. The colloidal correction decreased the volatilization flux of sigma PCBs by approximately 30%. The decachlorinated congener (PCB 209), exhibited unusually high concentrations in the suspended solids, especially in the southern portions of the river, indicating that there is a distinct source of PCB 209 in the Delaware River.