A multi-point optical fibre sensor for condition monitoring in process water systems based on pattern recognition

Preliminary results are presented for a multi-point optical fibre sensor designed to detect the presence of chemical species in water at spatial intervals of greater than 20 m. The sensor is addressed using optical time domain reflectometry (OTDR) with a spatial resolution of 10 m. The optical signals arising from the OTDR are highly complex due to interfering effects from external parameters such as localised fibre straining and temperature changes. Because of this level of complexity it has been found advantageous to use artificial neural networks (ANNs) as classifiers on the OTDR signals. The preliminary system has been trained initially to recognise only the presence of water, although it is planned to extend this capability to recognise the presence of contaminants in the water such as bacteria and chemical pollutants. Initial investigations show that different contaminants and interfering parameters (cross-sensitivities) may give rise to characteristic signatures on the OTDR signal which may be identified by the pattern recognition software.     

欧洲制冷技术新法规正式出台

2000年10月1日EG2037／2000开始生效,届时1994年12月15日颁布的EG3093／94失效。新规定基本上是根据1995年“蒙特利尔议定书”缔约国会议,并在欧洲范围内已经承担的义务上进行修订的,同时还引入了一个许可体系,该体系不仅仅是引入,而且要消除破坏臭氧层物质材料。1 法规的适用范围 在条款1中,对法规的适用范围作了简要说明,包括：生产、进口和出口、使用、回收、再生加工、处理和消毁,以及对破坏臭氧层的CFC、HCFC和该物质的衍生物的规定。该法规条款、章节内容的说明主要集中在制冷技术方面。 新的欧盟法规针对CFC和HCFC主…     

ESA’s Drop Tower Utilisation Activities 2000 to 2011

The European Space Research and Technology Center ESTEC, ESA’s premises in Noordwijk, The Netherlands, has a long lasting cooperation with the ZARM-FAB (Centre of Applied Space Technology and Microgravity—Drop Tower Operation and Service Company) in Bremen on the utilization of the Drop Tower for ground-based microgravity research and space hardware development studies. During the period January 2000 to December 2011 ESA will have procured in total some 840 drops addressing a variety of scientific and technological disciplines. The experiments are usually carried out in campaigns of 15 to 20 drops each, with an annual average of about 5 campaigns. The cooperation agreement between ESA and the ZARM-FAB includes experiment preparation advice by ZARM’s experts, the integration of the hardware into the drop capsule, dedicated safety reviews, the execution of the drop or catapult experiments, the post-flight payload de-integration as well as the handover of acquired data to the experimenters. The experiment hardware itself is provided by the scientists or has to be procured from sources outside of ESA’s drop tower utilization contract. ESA appreciates the cooperation of the ZARM-FAB in Bremen whose drop- and catapult facility provides excellent microgravity quality, is operated by a highly competent, flexible and extremely supportive expert team, allows campaign integration at relatively short notice throughout the entire year, offers real-time experiment operations and immediately after each drop delivers experiment results and provides on-site hardware modification possibilities.     

Prediction of the intramuscular fat content in loin muscle of pig carcasses by quantitative time-resolved ultrasound

A novel method for non-destructive intramuscular fat (IMF) estimation via spectral ultrasound backscatter analysis of signals obtained from pig carcasses early post mortem is described. A commercial hand-held ultrasound device (center frequency: 2.7 MHz) was modified to focus the sound beam to the longissimus muscle at the 2nd/3rd last rib. Time-resolved ultrasound backscatter signals of loin muscle were recorded 45 min p.m. on 82 pig carcass sides. Backfat width (d_BF = 18.9 ± 3.8 mm) and muscle attenuation (α_muscle = .77 ± .15 dB MHz^− 1 cm^− 1) were assessed from the measured pulse echo data. Other propagation properties of skin, backfat and muscle tissue obtained in a previous investigation were incorporated into the signal pre-processing to minimize parameter estimation artifacts. Spectral and cepstral parameters were derived from time-gated backscattered signals measured in the central muscle region. The range of intramuscular fat (IMF) determined by ether extraction was representative for German pig populations (.7% ≤ IMF_chem ≤ 3.6%, coefficient of variation CV(IMF_chem) = 44.8%). Variations of IMF were associated with variations of backfat width (CV(d_BF) = 20.2%), muscle attenuation (CV(α_muscle) = 19.3%), and slope of the backscattered amplitude spectrum (CV(m) = 28.8%). A full cross validated multiple linear regression model using these parameters resulted in good predictability of IMF_chem (R² = .76, RMSEP = .34%). Among all tested carcasses, 73% could be correctly classified into one of three IMF classes (LOW: < 1%, MID: 1-2%, HIGH: > 2%). Using a single threshold (2% IMF), about 92% of all carcasses were correctly classified. With respect to the inherent variability of IMF within a single muscle and the different tissue volumes used for the chemical and ultrasound based IMF estimations the remaining prediction errors are acceptable. Compared to previous ultrasound based studies, the number of acoustic parameters used for the IMF prediction could be reduced. Moreover, the used parameters are based on time-of-flight and spectral slope estimations, which are i) more robust with respect to measurement artifacts and ii) have a causal link to structural variations associated with IMF variations in pork loin.     

Experimental and modeling approach to study sorption of dissolved hydrophobic organic contaminants to microbial biofilms

A biofilm reactor was developed to investigate the sorption of polycyclic aromatic hydrocarbons (PAH) as model compounds for hydrophobic organic contaminants (HOC) to intact microbial biofilms at environmentally realistic concentrations. When operated as a differential column batch reactor, the system can be used to study the thermodynamics as well as the kinetics of the exchange of HOC between an aqueous phase and microbial biofilms. Organic carbon normalized partition coefficients (K(oc)) for phenanthrene, fluoranthene and pyrene were at the lower end of those known for other organic sorbents. Intra-biofilm diffusion coefficients (D) were calculated from decrease in solute concentration over time using a model for diffusion through a plane sheet and ranged from 0.23 to 0.45x10(-9)cm(2)s(-1) for the three PAH. These diffusion coefficients are about four orders of magnitude lower than those reported in literature for free aqueous solution. These data and the experimental approach presented here are useful to assess the importance of microbial biofilms for exchange processes of HOC in heterogeneous systems such as water distribution systems, membranes and aquifers, sewer systems or surface soils.     

Humanistic outcomes in the hypertension and COPD arms of a multicenter outcomes study

OBJECTIVE: To evaluate the effects of pharmaceutical care on selected humanistic outcomes in patients with hypertension or chronic obstructive pulmonary disease (COPD). DESIGN: Clinic patients with hypertension or COPD were randomly assigned to a treatment group (pharmaceutical care) or a control group (traditional pharmacy care) over a six-month period. Clinical pharmacists and pharmacy residents conducted the protocols. There were 133 evaluable patients (63 treatment, 70 control) in the hypertension study arm and 98 evaluable patients (43 treatment, 55 control) in the COPD study arm. The Pharmaceutical Care Questionnaire evaluated patient satisfaction with care. Tests specific to the disease states assessed disease and disease management knowledge. Quality of life (QOL) was evaluated using the Health Status Questionnaire 2.0 (HSQ 2.0) in the COPD arm; in the hypertension arm, the Hypertension/Lipid TyPE Specification Form 5.1 was used. SETTING: Ambulatory care centers of 10 Department of Veterans Affairs (DVA) medical centers and 1 university medical center. INTERVENTIONS: Patient-centered pharmaceutical care model (employing standardized care) implemented by clinical pharmacy residents. MAIN OUTCOME MEASURES: Satisfaction with pharmaceutical care, disease and disease management knowledge, and QOL. RESULTS: Statistically significant differences in most satisfaction items were found, with treatment patients expressing greater satisfaction. Treatment groups in both arms strongly agreed that pharmacists helped them with confidence in use of their medication and understanding of their illness, gave complete explanations about their medications, made them feel that their care was a priority, and followed up on their questions and concerns. In the hypertension arm, treatment patients demonstrated significant increases in knowledge scores. Trends in QOL were positive for both hypertension groups, with a significant decrease found in number of treatment patients reporting problems with sexual function. In the COPD arm, improvement trends were significantly stronger for treatment patients. CONCLUSION: Although patients were not dissatisfied with traditional pharmacy care, they were more satisfied overall with the pharmaceutical care model.     

FPGA价格不是衡量系统成本的最好指标

大多数工程师都知道现有三种基本的FPGA技术:反熔丝、FLASH和SRAM.其中,SRAM是迄今为止应用范围最广的架构,主要因为它具有可重编程能力,而反熔丝FPGA只提供一次可编程(OTP)方案.……     

EEG alpha spindles and prolonged brake reaction times during auditory distraction in an on-road driving study

Driver distraction is responsible for a substantial number of traffic accidents. This paper describes the impact of an auditory secondary task on drivers’ mental states during a primary driving task. N = 20 participants performed the test procedure in a car following task with repeated forced braking on a non-public test track. Performance measures (provoked reaction time to brake lights) and brain activity (EEG alpha spindles) were analyzed to describe distracted drivers. Further, a classification approach was used to investigate whether alpha spindles can predict drivers’ mental states.     

Avoiding the potential pitfalls of using negative priming tasks in developmental studies: Assessing inhibitory control in children, adolescents, and adults.

Despite being ignored, visual distractors often produce traceable negative priming (NP) effects that can be used to investigate inhibitory processes. Robust NP effects are typically found with young adults, but not with children. Using 2 different NP tasks, the authors compared NP in 5 different age groups spanning 5 to 25 years of age. The 1st task revealed comparable NP between all age groups, but a linear decrease in NP through childhood to early adulthood. In the 2nd task, NP decreased linearly into adulthood, with children actually showing larger NP than adults. This Age Group ? NP interaction was eliminated, however, when reaction time data were log transformed to control for age differences in overall processing speed. When appropriately transformed data were used, both experiments showed that NP was intact and comparable between children, adolescents, and adults, and suggested that an inhibitory process is fully developed by early childhood. The results highlight how potential pitfalls might be avoided when comparing NP in children and adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)