Treatment of spent metalworking fluids

Metalworking fluids (MWFs) are widely used for cooling and lubricating during the machining process. The worldwide annual usage is estimated to exceed 2 x 10(9)l and the waste could be more than ten times the usage, as the MWFs have to be diluted prior to use. For UK industry the disposal cost is estimated to be up to pound16 million per year. Used MWFs cause high levels of contamination and rancid odours due to the presence of complex chemicals, biocides, etc., so that their treatment and final disposal must be handled carefully. Conventionally this has been done by combined physical and chemical methods but, with tightened legislation, these routes are no longer acceptable. Now, biological treatment is being increasingly adopted as it seems to offer an alternative with the potential for significant cost saving. However, there are significant difficulties in operating bioreactors, such as maintenance of the stability of the microbial communities present in activated sludge plants (ASP). In order to resolve these problems, four major areas need to be considered: (1) the composition of the spent MWF and its inherent biodegradability, (2) the recalcitrant compounds existing in waste MWFs and their impact on microbes, (3) the nature of the microbial consortia and means of optimising it, e.g, temperature and the practical design of the bioreactor and (4) the requirements for nutrient supplements and optimal control conditions. The potential importance of understanding the microbial community has been studied by the use of molecular biological techniques such as polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), fatty acid methyl ester (FAME) and fluorescent in situ hybridization (FISH). The application of attached biofilm bioreactors and thermophilic aerobic technology (TAT) has also been studied. This review describes recent advances in each of these areas.     

Interaction between grounding pads used for RF ablation therapy and magnetic resonance imaging

Objectives: To characterize artifacts and imaging problems in the presence of conductive grounding pads for RF ablation therapy as well as potential heating problems due to induction of eddy currents in the pads. Strategies for avoidance of those problems are developed. Materials and methods: Underlying principles of interactions between grounding pads and MR imaging are reported. Influential parameters, e.g., orientation in relation to the magnetic field, shape of the grounding pad, sequence type (spin-echo versus gradient echo) and magnetic field strength (0.2 T, 1.5 T, 3 T) were varied in systematic phantom studies. Heating effects due to induced eddy currents were estimated theoretically and measured by infrared imaging in an adapted set-up. Results: MR imaging artifacts are markedly dependent on the orientation and geometrical shape of the grounding pads. Visible signal extinction artifacts were more pronounced using spin-echo techniques than in gradient echo images and increased for higher field strengths. Suitable incisions in the grounding pad reduced eddy currents markedly and minimized image artifacts. Heating problems due to induced eddy currents by the RF transmitted for MR imaging were excluded by phantom measurements. Conclusions: Suitable positioning of the grounding pads and adaptation of their geometry provide clearly reduced artifacts in MR imaging.     

Evaluation of training in patient handling and moving skills among hospital and home care personnel

The aim of the study was to evaluate the training programme in patient handling and moving skills according to the Stockholm Training Concept. The evaluation focused on work technique, musculoskeletal problems, job strain and the experience of the person being transferred. The training programme consisted of two models of learning: traditional groups and quality circles. Fifty-one people employed at geriatric hospitals and in primary care, participated in the training programme. For the evaluation, the participants were video-recorded in one standardized transfer situation: moving the patient from bed to wheelchair, before and after the training. The participants' work technique during the patient transfer was assessed using seven items. A questionnaire covering individual factors, physical exertion, job strain, and musculoskeletal problems, was filled in by the participants before training and also six months after. The results showed improvements in six of the seven work technique items, directly after training. A decrease in the participants' physical exertion during transfers of patients from 'bed to chair' was shown six months after completion of the training programme. There was no significant decrease in the participants' musculoskeletal problems and job strain after training. Ninety-eight per cent of the participants were positive about having participated in the training. Training in patient handling and moving skills led to improved work technique. The participants improved their transfer technique and experienced less discomfort during the transfer, and patients experienced greater comfort and safety when being transferred.     

Integrated design and operation of a transparent optical network: a systematic approach to include physical layer awareness and cost function [Topics in Optical Communications]

The manner and exact timing of the evolution of the widely used DWDM infrastructure to a transparent optical network is judged on economic circumstances and network performance. In this context this article elaborates on a methodology developed within the Project 1ST NOBEL, for integrating cost functions and other design constraints into the planning of a DWDM network while considering this evolution perspective to a transparent optical network. This systematic approach builds upon the experience of static network design and is substantiated by specific examples in this article     

Consumption of fruits and vegetables in relation to the risk of developing acute coronary syndromes; the CARDIO2000 case-control study

Background

The relation between diet and human health has long been investigated. The aim of this work is to evaluate the association between CHD risk and the consumption of fruit and vegetable, in a large sample of cardiac patients and controls.

Methods

Stratified sampling from all Greek regions, consisted of 848 (700 males, 58 ± 10 years old and 148 females, 65 ± 9 years old) randomly selected patients, admitted to the cardiology clinic for a first event of an acute coronary syndrome (ACS). In addition we selected 1078 frequency paired, by sex-age-region, controls in the same hospitals but without any clinical suspicion of CHD. Using validated food-frequency questionnaires we assessed total diet, including fruit and vegetable intake, on a weekly basis. Multiple logistic regression analysis estimated the relative risk of developing ACS by level of fruits and vegetables intake after taking into account the effect of several potential confounders.

Results

Data analysis revealed that the benefit of fruit or vegetable consumption increases proportionally by the number of servings consumed (P for trend < 0.001). After adjusting for the conventional cardiovascular risk factors, those in the upper quintile of fruit consumption (5 or more items/day) had 72% lower risk for CHD (odds ratio = 0.28, 95% CI 0.11 – 0.54, P < 0.001), compared with those in the lowest quintile of intake (<1 items/day). Similarly, consumption of vegetable more than 3 days / week was associated with 70% lower risk for CHD (odds ratio = 0.30, 95% CI 0.22 – 0.40, P < 0.001), compared with those that they did not consume vegetables. Of particular interest, a 10% reduction in coronary risk was observed for every one piece of fruit consumed per day (odds ratio = 0.90, 95% CI 0.85 – 0.97, P = 0.004).

Conclusions

Consumption of fruits and vegetables seems to offer significant protection against CHD.

     

Use of information on the manufacture of samples for the optical characterization of multilayers through a global optimization

We present a procedure for the optical characterization of thin-film stacks from spectrophotometric data. The procedure overcomes the intrinsic limitations arising in the numerical determination of many parameters from reflectance or transmittance spectra measurements. The key point is to use all the information available from the manufacturing process in a single global optimization process. The method is illustrated by a case study of solgel applications.     

Work measurement for estimating food preparation time of a bioregenerative diet

During space missions, such as the prospective Mars mission, crew labor time is a strictly limited resource. The diet for such a mission (based on crops grown in a bioregenerative life support system) will require astronauts to prepare their meals essentially from raw ingredients. Time spent on food processing and preparation is time lost for other purposes. Recipe design and diet planning for a space mission should therefore incorporate the time required to prepare the recipes as a critical factor. In this study, videotape analysis of an experienced chef was used to develop a database of recipe preparation time. The measurements were highly consistent among different measurement teams. Data analysis revealed a wide variation between the active times of different recipes, underscoring the need for optimization of diet planning. Potential uses of the database developed in this study are discussed and illustrated in this work.     

Transfer of Salmonella and Campylobacter from stainless steel to romaine lettuce

The degree of transfer of Campylobacter jejuni and Salmonella enterica serovar Typhimurium was evaluated from a stainless steel contact surface to a ready-to-eat food (lettuce). Stainless steel coupons (25 cm2) were inoculated with a 20-microl drop of either C. jejuni or Salmonella Typhimurium to provide an inoculum level of approximately 10(6) CFU/28 mm2. Wet and dry lettuce (Lactuca sativa var. longifolia) pieces (9 cm2) were placed onto the inoculated stainless steel surface for 10 s after the designated inoculum drying time (0 to 80 min for C. jejuni; 0 to 120 min for Salmonella Typhimurium), which was followed by the recovery and enumeration of transferred pathogens (lettuce) and residual surface pathogens (stainless steel coupons). For transfers of Salmonella Typhimurium to dry lettuce, there was an increase from 36 to 66% in the percent transfer of the initial inoculum load during the first 60 min of sampling and then a precipitous drop from 66 to 6% in percent transfer. The transfer of Salmonella Typhimurium to wet lettuce ranged from 23 to 31%, with no statistically significant difference between recoveries over the entire 120-min sampling period. For C. jejuni, the mean percent transfer ranged from 16 to 38% for dry lettuce and from 15 to 27% for wet lettuce during the 80-min sampling period. The results of this study indicate that relatively high numbers of bacteria may be transferred to a food even 1 to 2 h after surface contamination. These findings can be used to support future projects aimed at estimating the degree of risk associated with poor handling practices of ready-to-eat foods.     

Usability issues concerning child restraint system harness design

A study was conducted to assess usability issues relating to child restraint system (CRS) harness design. Four convertible child restraint systems representing a wide variety of design features were used. Forty-two participants installed two child test dummies in both forward- and rear-facing configurations either inside or outside a test vehicle. Observer-scored checklists determined the degree to which each harness was installed correctly. Participant-scored questionnaires evaluated the 'ease-of-use' of various design features. While the percentage of correct installations exceeded 83% for all designs when installed in the forward-facing configuration, in the rear-facing position (that intended for children under 9-10 kg), there was a significant (between 65 and 89%) percentage of incorrect installations for all models. This finding is of particular interest and may be indicative of a more generalized problem with 'convertible' CRS designs when they are used in the rear-facing configuration. Furthermore, while certain design features were perceived by users as providing significantly better protection in the event of a collision, these also tended to be the features that were misused most often. The benefits and costs of various design features are discussed, and a method to test harness design usability is presented.