Castrol (United Kingdom)

This tutorial review focuses on recent advances in technologies for enzyme immobilisation, enabling their cost-effective use in the bio-based economy and continuous processing in general. The application of enzymes, particularly in aqueous media, is generally on a single use, throw-away basis which is neither cost-effective nor compatible with a circular economy concept. This shortcoming can be overcome by immobilising the enzyme as an insoluble recyclable solid, that is as a heterogeneous catalyst.

OBJECTIVE: To determine whether screening for a blast mechanism of concussion identifies individuals at higher risk of persistent postconcussive symptoms (PCS). SETTING: United States Army post. PARTICIPANTS: 3952 US Army infantry soldiers were administered anonymous surveys 3 to 6 months after returning from a yearlong deployment to Iraq. MAIN OUTCOME MEASURES: Self-reported concussion (defined as an injury that resulted in being "dazed, confused, or 'seeing stars'"; "not remembering the injury"; or "losing consciousness [knocked out]): Patient Health Questionnaire 15-item scale for physical symptoms and PCS; Posttraumatic Stress Disorder Checklist; and Patient Health Questionnaire depression module. RESULTS: Of the 587 soldiers (14.9% of the total sample) who met criteria for concussion, 201 (34.2%) reported loss of consciousness, and 373 (63.5%) reported only an alteration of consciousness without loss of consciousness; 424 (72.2%) reported a blast mechanism, and 150 (25.6%) reported a nonblast mechanism. Among soldiers who lost consciousness, blast mechanism was significantly associated with headaches and tinnitus 3 to 6 months postdeployment compared with a nonblast mechanism. However, among the larger group of soldiers reporting concussions without loss of consciousness, blast was not associated with adverse health outcomes. CONCLUSIONS: Blast mechanism of concussion was inconsistently associated with PCS, depending on the definition of concussion utilized. A self-reported history of blast mechanism was not associated with persistent PCS for the majority of US soldiers with concussions.

Abstract The effects of motorway runoff on the water quality, sediment quality, and biota of small streams were investigated over a 12-month period. Downstream of motorway runoff discharges there was an increase in the sediment concentrations of total hydrocarbons, aromatic hydrocarbons, and heavy metals and an increase in the water concentrations of heavy metals and selected anions. Hydrocarbon contamination of sediments was positively correlated with potential contaminant loading (i.e., length of road drained/stream size). The greatest effect was observed at Pigeon Bridge Brook, a small stream receiving drainage from a 1,500-m stretch of the Ml motorway. The dominant PAHs in contaminated sediment at this site were phenanthrene, pyrene, and fluoranthene, whereas the dominant metals were zinc, cadmium, chromium, and lead. Differences between the station upstream and downstream of discharges in the diversity and composition of the macroinvertebrate assemblages were detected in four out of the seven streams surveyed. However, there was no evidence of an effect on either the diversity or abundance of epilithic algae. The diversity of the aquatic hyphomycete assemblage was only affected at the most impacted site. Reductions in macroinvertebrate diversity were associated with reductions in the processing of leaf litter and a change from an assemblage based on benthic algae and coarse particulate organic matter to one dependent upon fine particulate organic matter.

The effects of motorway runoff on the water quality, sediment quality, and biota of small streams were investigated over a 12-month period. Downstream of motorway runoff discharges there was an increase in the sediment concentrations of total hydrocarbons, aromatic hydrocarbons, and heavy metals and an increase in the water concentrations of heavy metals and selected anions. Hydrocarbon contamination of sediments was positively correlated with potential contaminant loading (i.e., length of road drained/stream size). The greatest effect was observed at Pigeon Bridge Brook, a small stream receiving drainage from a 1,500-m stretch of the Ml motorway. The dominant PAHs in contaminated sediment at this site were phenanthrene, pyrene, and fluoranthene, whereas the dominant metals were zinc, cadmium, chromium, and lead. Differences between the station upstream and downstream of discharges in the diversity and composition of the macroinvertebrate assemblages were detected in four out of the seven streams surveyed. However, there was no evidence of an effect on either the diversity or abundance of epilithic algae. The diversity of the aquatic hyphomycete assemblage was only affected at the most impacted site. Reductions in macroinvertebrate diversity were associated with reductions in the processing of leaf litter and a change from an assemblage based on benthic algae and coarse particulate organic matter to one dependent upon fine particulate organic matter.

Abstract Previous studies have provided prima facie evidence that runoff from the Ml motorway, UK, affects both the quality of the receiving water and the biota living there, in sites short distances from point sources —i.e., possible worst-case situations. Because discharges contain a wide variety of contaminants, both the identification of toxicants and the establishment of causal relationships between observed changes in water/sediment quality and biology are often difficult. In this particular case, the problem was addressed by conducting a series of toxicity tests using the benthic amphipod Gammarus pulex. The abundance of this species was greatly reduced downstream of the point where motorway runoff entered the stream. Stream water contaminated with motorway runoff was not toxic to G. pulex. However, exposure to contaminated sediments resulted in a slight reduction in survival over 14 d, and sediment manipulation experiments identified hydrocarbons, copper, and zinc as potential toxicants. Spiking experiments confirmed the importance of hydrocarbons, and fractionation studies indicated that most of the observed toxicity was due to the fraction containing polycyclic aromatic hydrocarbons. Animals exposed to contaminated sediments and water spiked with sediment extract accumulated aromatic hydrocarbons in direct proportion to exposure concentrations.

A combined single-source precursor approach has been developed for the deposition of thin films of Cr-doped molybdenum disulfide (MoS2) by aerosol-assisted chemical vapor deposition (AACVD). Tris(diethyldithiocarbamato)chromium(III) can also be used for the deposition of chromium sulfide (CrS). Films have been analyzed by a range of techniques including scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, Raman spectroscopy, and powder X-ray diffraction (pXRD) to elucidate film morphology, composition, and crystallinity. The presence of Cr in the MoS2 films produces a number of striking morphological, crystallographic, and nanomechanical changes to the deposited films. The chromium dopant appears to be uniform throughout the MoS2 from the scanning transmission electron microscopy (STEM) EDX spectrum imaging of nanosheets produced by liquid-phase exfoliation of the thin films in N-methyl-2-pyrollidone.

The application of the droplet quartz crystal microbalance (QCM) to the measurement of viscosity for industrial oils is reported. In this approach a small-volume droplet of fluid is investigated via its influence on the resonant frequency of a quartz oscillator. The droplet QCM viscosity response is investigated for a selection of industrial oils, including commercial automotive lubricants, heavy fuel oils, calibration oils and used automotive lubricating oils. This approach shows significant analytical promise for distinguishing between heavy fuel oils dyed to indicate their duty status. It is also demonstrated that lubricating oils aged in engine tests exhibit an enhanced QCM viscosity response than accepted viscosity measurements would otherwise indicate. The locus at which the viscosity response saturates due to violation of the small loading approximation (extreme viscosities) is identified and found to be qualitatively consistent with established equivalent circuit models. The identification of commercial lubricating oils is observed to be unreliable on the basis of viscosity response alone.

Direct observations on nanopillars composed of molybdenum disulfide (MoS2) and chromium-doped MoS2 and their response to compressive stress have been made. Time-resolved transmission electron microscopy (TEM) during compression of the submicrometer diameter pillars of MoS2- and Cr-doped MoS2 (Cr: 0, 10, and 50 at %) allow the deformation process of the material to be observed and can be directly correlated with mechanical response to applied load. The addition of chromium to the MoS2 changed the failure mode from plastic deformation to catastrophic brittle fracture, an effect that was more pronounced as chromium content increased.

Water-based metalworking fluids (MWFs) may cause both irritant and allergic contact dermatitis. Several well-known MWF allergens are available for patch testing, but considering the wide variety of possible components used in MWF, our diagnostic arsenal covers only a small part of potential allergens. We therefore selected 13 frequently used MWF components that might be sensitizers and had not yet been tested routinely. In 5 centres, 233 dermatitis patients with present or past occupational exposure to MWF were patch tested with this and other panels. Only 7 patients showed positive reactions to the study panel. Allergic reactions to the emulsifier diglycolamine [syn. 2-(2-aminoethoxy) ethanol] were seen in 5 patients, and 1 patient each reacted positively to 2-amino-2-ethyl-1,3-propanediol (AEPD) and methyldiethanolamine (MDEA). Clinical relevance of the reactions to diglycolamine was unequivocally proven by its presence in the MWF from the patients' workplace in 3 cases. Diglycolamine seems to be an important MWF allergen, independently from monoethanolamine and diethanolamine. A test concentration of 1% petrolatum (pet.) appears to be appropriate. The importance of AEPD and MDEA as MWF allergens still remains to be established. The lack of positive test reactions to the other MWF components tested may be due to their low-sensitizing potential or too low a patch test concentration being used.

Commercial scanning white light interference microscopes are able to map surface topography to very high resolution and can thus measure very small amounts of wear on rubbed surfaces. These instruments are therefore being increasingly used to study aspects of mild wear. It is shown in this Technical Note that, when used on surfaces that have been rubbed in lubricants containing the antiwear additive zinc dialkyldithiophosphate (ZDDP), some white light interference microscopes can produce an apparent but spurious wear measurement. The transparent and relatively thick antiwear film generated by ZDDP on rubbed surfaces produces an optical path difference that is incorrectly interpreted as wear. It is thus suggested that surfaces that have been rubbed in lubricants containing ZDDP or other thick film-forming additives should be treated to remove tribofilms prior to wear measurement using scanning interference microscopy.

OBJECTIVE: The California heat illness prevention study (CHIPS) devised methodology and collected physiological data to assess heat related illness (HRI) risk in Latino farmworkers. METHODS: Bilingual researchers monitored HRI across a workshift, recording core temperature, work rate (metabolic equivalents [METs]), and heart rate at minute intervals. Hydration status was assessed by changes in weight and blood osmolality. Personal data loggers and a weather station measured exposure to heat. Interviewer administered questionnaires were used to collect demographic and occupational information. RESULTS: California farmworkers (n = 588) were assessed. Acceptable quality data was obtained from 80% of participants (core temperature) to 100% of participants (weight change). Workers (8.3%) experienced a core body temperature more than or equal to 38.5 °C and 11.8% experienced dehydration (lost more than 1.5% of body weight). CONCLUSIONS: Methodology is presented for the first comprehensive physiological assessment of HRI risk in California farmworkers.

Operationally exhausted metal working fluids are chemically mixed, produced in large quantities (400 000 tonnes year in the U.K.), and potentially environmentally toxic. It is essential to develop more reliable and economical approaches for their disposal. We investigated the effectiveness of a defined bacterial consortium, constructed specifically for treating metal-working fluid (MWF), and contrasted its performance to that of undefined inocula from activated sludge. Construction of the consortium was based on knowledge of the diversity of bacterial communities that naturally colonize MWF and determination of their catabolic abilities and tolerance to the chemical constituents. Chemical analysis of the inoculated MWF bioreactor revealed that, after 100 h at 28 degrees C, the defined inoculum reduced the pollution load by over 80% from an initial chemical oxygen demand of approximately 48 000 mg L(-)(1). The inocula performance was approximately 50% more effective than that of the undefined microbial community from the activated sludge. Furthermore, the performance of the constructed consortium was more reproducible than that of an undefined community, an essential feature for bioaugmentation treatment of industrial wastes.

The aim of this research was to determine the effectiveness of a strategy for constructing microbial consortia for treating chemically mixed industrial effluent, based on a more thorough understanding of communities within waste metal-working fluids (MWFs). Complementary phenotypic and genotypic methods revealed that the microbial communities in spent MWFs had low diversity and were very similar in species composition in samples originating from different locations and uses. Of 65 bacterial isolates studied, only 9 species were identified using fatty acid methyl ester (FAME) analysis. The results of genotypic analysis by denaturing gradient gel electrophoresis (DGGE) were congruent with observations made using FAME analysis. The metabolic potential of the isolates was assessed in terms of assimilation ability and tolerance of co-contaminants. The three isolates, selected (Clavibacter michiganensis, Methylobacterium mesophilicum, and Rhodococcus erythropolis) to form a consortium, were representative of three of the four most abundant populations and when combined could utilise or tolerate all of the individual MWF components, including the biocide and the recalcitrant compound benzotriazole.

OBJECTIVE: Determine compliance with and effectiveness of California regulations in reducing farmworkers' heat-related illness (HRI) risk and identify main factors contributing to HRI. METHODS: In a cross-sectional study of Latino farmworkers, core body temperature (CBT), work rate, and environmental temperature (WBGT) were monitored over a work shift by individual ingestible thermistors, accelerometers, and weather stations, respectively. Multiple logistic modeling was used to identify risk factors for elevated CBT. RESULTS: Although farms complied with Cal/OSHA regulations, worker training of HRI prevention and hydration replacement rates were insufficient. In modeling (AOR [95% CI]) male sex (3.74 [1.22 - 11.54]), WBGT (1.22 [1.08 - 1.38]), work rate (1.004 [1.002 - 1.006]), and increased BMI (1.11 [1.10 - 1.29]) were all independently associated with elevated CBT. CONCLUSION: Risk of HRI was exacerbated by work rate and environmental temperature despite farms following Cal/OSHA regulations.

A review is undertaken of the important trends in engine lubricant performance tests that have taken place over the last 10-15 years. Lubricant formulations are driven by industry standard specifications, original equipment manufacturer requirements, and consumer needs. A review is given of the important specifications and associated performance tests, and how these have impacted on lubricant development. The key trends are, firstly, the need for improved fuel economy, secondly, the need for improved oxidation stability, thirdly, the need for improved handling of contaminants (e.g. soot), and, fourthly, the recent move to lubricants containing low levels of sulphur, phosphorus, and sulphated ash, for after-treatment device compatibility reasons.

<div class="htmlview paragraph">This paper investigates some of the parameters involved in the mechanism of poisoning of automotive three-way catalysts and Lambda sensors by means of a purpose designed engine test procedure. The aged catalysts have been examined both in terms of their conversion efficiency and surface chemical properties by SEM and EPMA techniques. Lambda sensors were also aged in the test engine and their sensitivity to lubricant phosphorus content and exhaust gas temperature examined.</div> <div class="htmlview paragraph">Results from 55 engine tests on 24 oils formulated with differing chemistries confirm that there is a strong link, which is statistically significant (99% confidence level), between lubricant phosphorus content and catalyst performance, but surprisingly oil consumption does not appear significant. The mechanism whereby the oil is combusted is proposed as being a determining factor. High phosphorus type oils reduced oxygen sensor performance, particularly at low exhaust temperatures (urban duty). Little or no sensor deterioration was evident when using low phosphorus oils.</div>

PURPOSE: Patients with chronic obstructive pulmonary disease (COPD) have body balance deficits, with consequent fall risk. It is possible that body sway in patients with COPD affects their ability to perform daily activities. The purpose of this study was to determine whether body balance is similar in patients with COPD and healthy persons when performing static and dynamic activities. In addition, we wanted to assess whether impairment of balance is related to the presence of falls in patients with COPD. METHODS: This is a cross-sectional study, in which every spirometric classification in patients with COPD (mild, moderate, severe, and very severe degrees) and age-matched healthy subjects was assessed. Subjects who were current smokers and patients who underwent physical training in the last 6 months prior to the start of the study were excluded. Static balance was assessed by computerized posturography and dynamic body balance using the Berg Balance Scale. RESULTS: Ninety-three patients with COPD and 39 healthy persons were evaluated. Mean age was 67.3 (10.8) and 65.1 (9.7) years and mean forced expiratory volume in 1 second (FEV1) was 50.4 (19.0) and 89.2 (23.6) for patients with COPD and healthy individuals, respectively. The impairment of body balance was higher for the group of patients with COPD (P = .0005). Patients with greater impairment in body balance had greater incidence of falls, and body balance was more affected with age in patients with COPD than in healthy persons. CONCLUSION: Impairment of body balance is more frequent in patients with COPD than in healthy persons while performing dynamic activities, and a greater incidence of falls activities was also found for this group.

The tribological performance of the cast iron/Al—Si alloy system lubricated in the boundary regime, using lubricants containing zinc dialkyldithiophosphate (ZDDP) and molybdenum dithiocarbamate (MoDTC) additives have been investigated. The results obtained are discussed in relation to the performance of these additives in cast iron/steel (ferrous)-based material systems. Tribological tests were conducted on a Plint reciprocating test machine (TE 77) in the contact conditions comparable to the conditions in the piston ring/cylinder liner system of the internal combustion engine. Surface sensitive analytical techniques such as environmental scanning electron microscopy and energy dispersive X-ray analysis have been used to determine the nature of the wear occurring as well as the chemical nature of the tribofilms formed on the Al—Si material. It has been shown that the MoDTC additive, added into a ZDDP-containing lubricant, improves the effectiveness of friction reduction in a completely ferrous system and a cast iron/Al—Si system. In terms of wear, an increase in MoDTC concentration (from 0.22 to 1.2 wt%) in the ZDDP-containing lubricant resulted in an antagonistic effect on the anti-wear performance of ferrous materials but improved the effect on Al—Si alloys. The tribofilm formation and wear mechanisms are discussed in relation to recent literature and it is shown that additives strongly affect both the processes.

The information explosion era provides the foundation for a technological solution to enable the visually impaired to more independent living in the community. This paper first provides a review of assistive technologies for visually impaired people. Current technology allows applications to be efficiently distributed and operated on mobile and handheld devices. Thus, this paper also summarizes recent developments of assistive technologies in mobile interaction. It then presents the Wireless Intelligent Assistive Navigation Management System Using SmartGuide Devices for visually impaired people. The “SmartGuide” of the system is built as a standalone portable handheld device. The system is to assist blind and low vision people to walk around independently especially in dynamic changing environments. It also includes a camera sensor network to enhance monitoring capabilities for an extra level of security and reliability. Finally, the paper presents an improved system with some new designs involving mobile interaction.

Hazardous materials releases can cause substantial morbidity and mortality, but very few studies have systemically investigated them. We analyzed responses by Massachusetts' six district hazardous materials (HAZMAT) teams from the time of their inception through February 1994. Spills, leaks, and other escapes of materials caused or contributed to 67 of 85 (79%) incidents. Transportation-related accidents accounted for 13 of 83 (16%), whereas the remainder of the releases occurred at fixed facilities. The chemicals most frequently involved were various hydrocarbons and corrosive materials. Most incidents (60 of 85 [70%]) had no reported injuries. Civilians were injured in 18 of 85 (21%) incidents; regular fire fighter and/or police were injured in eight of 85 (9%) incidents; and HAZMAT team members in one of 85 incidents (1%). Systematic study is needed to identify preventable causes of HAZMAT responses as well as ideas for better control of secondary health effects.