Nonlinearly strain-chirped fiber Bragg grating with an adjustabledispersion slope

In this letter, we demonstrate an adjustable dispersion slope compensator for waveform distortion compensation based on a nonlinearly strain-chirped fiber Bragg grating. The dispersion slope of the device can be tuned up to -18.9 ps/nm² with a bandwidth >2.4 nm. After transmission through a 120-km-long dispersion-shifted fiber, the resulting waveform distortion for a 2.65-ps pulse is successfully compensated by using this device     

Interface quality of SiGe oxide prepared by RF plasma anodisation

The latest progress in RF plasma anodisation of SiGe alloys at 80°C is reported. Compared with the authors' previous results, considerable improvement in interfacial quality has been achieved. However, unlike the thermally grown samples. No negative fixed oxide charges were found     

Characterization of anterior cruciate ligament cells and bone marrow stromal cells on various biodegradable polymeric films

In this study, the adhesion, proliferation and morphology of rabbit anterior cruciate ligament (ACL) cells and bone marrow stromal cells (bMSCs) on synthetic biodegradable polymeric films were investigated. Tissue culture polystyrene (TCP) was used as control. Seven biodegradable polymers were used; they are as follows: poly(-caprolactone) (PCL), poly( -lactide) ( -PLA), poly( -lactide) ( -PLA), PLA/PCL (50:50), PLA/PCL (75:25), high molecular weight (HMW) poly( -lactide–co-glycolide (PLGA50:50) and HMW PLGA75:25. Polymeric film substrates were manufactured using solvent spin-casting technique. After 8 h of cell culture, a high percentage of ACL cells was found attached to PLGA50:50 (38.6±8.4%) and TCP (39.3±6.1%) as compared to the other six polymeric films (p≤0.001). As for bMSCs, 76.4±10%, 76.3±16% and 76.1±19% of seeded bMSCs were adhered to TCP, PLGA50:50 and PLGA75:25, respectively. These were significantly more than those of the other five polymeric films (p<0.001). At Day 5, bMSCs were found to proliferate faster on TCP (by 7±0.8-fold of initial cell seeding number), -PLA (by 5.6±1.6-fold), PLGA50:50 (by 9.3±1.3-fold) and PLGA75:25 (by 5.8±1.3-fold) than on PCL, PLLA and PCL/PLA (50:50, 25:75) (p<0.001). ACL cells had a greater fold expansion on TCP (by 3.5±0.2-fold), PLGA50:50 (by 3.1±0.4-fold) and PLGA75:25 (by 3.9±0.4-fold) than on the other five polymer substrates (p<0.001). From these results, HMW PLGA (50:50, 75:25) was shown more likely to allow bMSCs and ACL cells to attach and proliferate, and bMSCs attached and proliferated faster than ACL cells.     

Some effective control chart procedures for reliability monitoring

Control charts are widely used for process monitoring in the manufacturing industry. Little research is available on their use to monitor the failure process of components or systems, which is important for equipment performance monitoring. Some Shewhart control charts, especially those for the number of defects, can be used for monitoring the number of failures per fixed interval; however, they are not effective especially when the failure frequency becomes small. A recent control scheme based on the cumulative quantity between observations of defects has been proposed which can be easily adopted to monitor the failure process for exponentially distributed inter-failure time. An investigation of its use for reliability monitoring is presented in this paper and the scheme can be easily extended to monitor inter-failure times that follow other distributions such as the Weibull distribution. Furthermore, the scheme is extended to the monitoring of time required to observe a fixed number of failures. The advantages of this scheme include the fact that the scheme does not require any subjective sample size, can be used for both high and low reliability items and can detect process improvement even in a high-reliability environment.     

Analysis of cholesterol and desmosterol in cultured cells without organic solvent extraction

Cultured cell sterols such as cholesterol and desmosterol are usually extracted into organic solvents before they are quantified with cholesterol esterase and oxidase. A method to quantify these cultured cell sterols using cholesterol enzymes without prior organic solvent extraction is described. In this method, a suspension or monolayer of cultured L-M, U-937, or PC-12 cells is digested with 0.1% sodium dodecyl sulfate (SDS), and the digest treated with microbial cholesterol enzymes. The quantity of oxidized sterols produced by the reaction can be measured easily with high-pressure liquid chromatography, when a mixture of sterols is present, or by the production of hydrogen peroxide when only one sterol is present. This method is easier and safer to use than solvent extraction and can greatly expedite the quantitation of cultured cell sterols. Preliminary data show that other lipids such as choline phospholipids, triglycerides, and fatty acids can also be directly quantified in SDS cell digest by using specific enzymes to transform these lipids into hydrogen peroxides.     

Influence of a partner on tolerance for a self-administered electric shock.

Ss were tested alone in setting the maximum electric shock they could tolerate and in another situation in which a partner apparently shared the shock. It was found that shock tolerance was significantly higher in the situation involving a partner and it was concluded that "the perceived sharing of stress contributes importantly to stress tolerance." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Determining the steady-state temperature field in a cracked plate with heat transfer from the lateral surfaces

The heat conduction problem is considered in the case of a plate with a thermally insulated straight crack and with a given prior temperature field in the solid plate. The heat transfer from the plate to the ambient medium is assumed to follow Newton's law.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 23, No. 1, pp. 126–131, July, 1972.     

Recovery of photoinduced reversible dark States utilized for molecular diffusion measurements

For a spatially restricted excitation volume, the effective modulation of the excitation in time is influenced by the passage times of the molecules through the excitation volume. By applying an additional time-modulated excitation, the buildup of photoinduced reversible dark states in fluorescent molecules can be made to vary significantly with their passage times through the excitation volume. The variations in the dark state populations are reflected by the time-averaged fluorescence intensity, which thus can be used to characterize the mobilities of the molecules. The concept was experimentally verified by measuring the fluorescence response of freely diffusing cyanine fluorophores (Cy5), undergoing trans-cis isomerization when subject to time-modulated excitation in a focused laser beam. From the fluorescence response, and by applying a simple photodynamic model, the transition times of the Cy5 molecules could be well reproduced when applying different laminar flow speeds through the detection volume. The presented approach puts no constraints on sample concentration, no requirements for high time resolution or sensitivity in the detection, nor requires a high fluorescence brightness of the characterized molecules. This can make the concept useful for a broad range of biomolecular mobility studies.     

Limited economic evaluation to assess the effectiveness of a university-wide office ergonomics program

The objective of this research was to evaluate the effectiveness and provide a limited economic evaluation of an office ergonomics program at a major university from 1995 to 2007. The relationship between office-related recordable injuries, reported lost time, severity of these injuries, and the Workers' Compensation (WC) paid was analyzed and the corresponding incident cost was calculated. Two major datasets analyzed were OSHA 200/300 logs (1991-2007) and WC claims paid (1999-2007). Since the beginning of the office ergonomics program in 1995 and through 2007 (13-year period), the number of office cumulative trauma disorder (CTD) cases decreased by 53%. Since the official start (in 1999) of a 50-50 cost share agreement for office equipment purchases between the university's Safety and Health Department (SHD) and the university departments evaluated, it was observed that the incident rate decreased by 63%, Total Days Away/restrict or Transfer (DART) rate decreased by 41%, Lost Time Case (LTC) rate decreased by 71% and office-related carpal tunnel syndrome decreased by almost 50%. The long-term goal of this research is to demonstrate the self-sustainability of an office ergonomics program by showing that equipment costs are eventually offset by a decrease in WC claims paid and lost time from office-related injuries and illnesses. While limited, this research helps in cost-justifying the implementation of future office ergonomics programs for large organizations.