Electronic lighting interference

This article presents empirical laboratory and field data documenting electromagnetic interference between high-efficiency electronic lighting and certain other electronic devices. Typical equipment involved are power-line carrier systems, security systems, and remote controls for televisions and VCRs. Reported cases involving both electronic lighting emissions and immunity in building power systems are summarized according to basic interference mechanisms. To illustrate the potential complexities of this problem, the article describes a case where high-efficiency lighting interfered with a hearing aid. The discussion of the case includes a field survey, laboratory investigations, and recommended solutions to the problem. To conserve energy, electric utilities have carried out demand-side management (DSM) programs that include installing electronic lighting in commercial and government buildings. Millions of electronic ballasts and compact fluorescent lamps (CFLs) have been installed. Several cases of new electronic lighting interfering with other appliances have been documented and are being studied by the Electric Power Research Institute (EPRI) Power Electronics Applications Center (PEAC). This research will help to determine how appliances interact with radiated and conducted emissions from ballasts. Although these cases do not represent a large percentage of installations, lighting manufacturers have risen to the challenge of identifying design solutions to several of the problems that have been identified.     

A report on HIPERLAN standardization

HIPERLAN is the new European standard for radio LANs currently being formulated by ETSI RES10 for operation at 5 GHz and 17 GHz. It will be suitable for radio replacement of wired LANs and for ad hoc networking providing a user data rate of 10–20 Mbit/s. This paper is a review of the work of ETSI RES10 on the formulation of the HIPERLAN standard. The origins of ETSI RES10 are documented. The targets set for HIPERLAN and the problems in achieving these targets are discussed. The paper reviews the technical arguments for and against the proposed solutions to these problems, concentrating on the design of the transmission scheme and the channel access mechanism. The discussions leading to significant decisions about the standard are summarized. If the FCC in the United States of America allocate the equivalent 5 GHz band to unlicensed wireless LAN systems, many of these discussions will be revisited for future standards in this band. The paper will be of interest to anyone in academia or industry wishing to be brought quickly up to date with the state of the standard in order to focus their research or development activities. The paper also gives a general insight into the technical side of the standards formulation process in ETSI.     

Dosimetric models for thorium and practical problems in assessing intakes

An overview is given of the models recommended by the International Commission on Radiological Protection (ICRP) for assessing intakes and doses, and summarises biokinetic data obtained after the deposition of different chemical compounds of thorium in the rat lung. The results emphasise the importance of using material-specific data rather than default reference values for absorption into blood. The limitations of external monitoring of the chest or urine analysis are discussed, and comments made on alternative strategies for radiological protection of the worker.     

Exploring the utility of NOAA AVHRR middle infrared reflectance to monitor the impacts of ENSO-induced drought stress on Sabah rainforests

The ever-wet tropics are under threat from ENSO events and there is a need for a monitoring system to analyse and describe their responses to such events. This letter explores the relative value of using NOAA AVHRR middle infrared (MIR) reflectance data and NDVI data for the monitoring of ENSO-related drought stress of a tropical forest ecosystem in Sabah, Malaysia. Relationships between rainfall and MIR reflectance were examined. Correlation coefficients are generally large and significant (at 0.1 level) while those between rainfall and NDVI were small and insignificant. This letter concludes that there is potential in using MIR reflectance for monitoring the effects of ENSO-induced drought stress on these forests and this has a bearing on how NOAA AVHRR data may be used to further our knowledge on the impacts of ENSO events on tropical forest environments.     

A naturalistic decision-making perspective on anaesthetists’ rule-related behaviour

As a widely recognised feature of work activity, procedural violations have been of considerable interest to human factors specialists, and several models have been proposed to aid in understanding their occurrence. A common feature of these models is that they depict violations as being, to a greater or lesser extent, intentional; therefore, rule-related behaviour could be reconceptualised as an exercise in decision-making. In this paper, we examine anaesthetists’ use of rules from the perspective of naturalistic decision-making. Doing so suggests that their rule-related behaviour is a product of the extent to which following a rule is consistent with other principles that guide their decision-making. Observational and interview data from 23 consultant anaesthetists indicated the presence of three such principles: “doing the right thing”; “doing what works in the circumstances”; and “using one’s skills and expertise”. Hence, rule-related behaviour in this setting is better understood as a form of situated action than as the following or breaking of rules per se. We discuss the implications of this view for understanding why violations occur, and how to address them.     

Nonclinical model for assessing gastric effects of bisphosphonates

Mechanisms by which ketones potentiate manganese-bilirubin (Mn-BR)-induced cholestasis are unknown. The purpose of the present study was to investigate the effect of methyl isobutyl ketone (MiBK), a widely used ketonic solvent, at the level of the bile canalicular membrane (BCM) and to verify if altered membrane lipid dynamics could be involved in MiBK-potentiated Mn-BR cholestasis. Male Sprague-Dawley rats were exposed 4 hr/day for 3 days to MiBK vapors (200 or 600 ppm). Eighteen hours after the last exposure, manganese (Mn, 4.5 mg/kg) was given i.v. followed 15 min later by bilirubin (BR, 25 mg/kg). Rats were killed 30 min after BR; liver cell plasma membranes (bile canalicular and sinusoidal), microsomes, mitochondria, and cytosol were isolated by differential centrifugation. Lipids were extracted and cholesterol was measured in each fraction. After Mn-BR and MiBK exposure (600 ppm), results indicated a marked increase in BCM cholesterol content compared to rats exposed to air only. This increase was greater than that due to Mn-BR or MiBK given alone. Also, results indicated that cholesterol increased in a dose-related fashion in BCM after MiBK exposure, whereas PM cholesterol remained unaltered. To identify the source of the increased BCM cholesterol and to permit distinction between de novo cholesterol synthesis and subcellular shifts, the hepatic lipid pool was labeled in vivo with [3H]-cholesterol and [2-14C]-mevalonic acid, a cholesterol synthesis precursor. Results showed that after 600 ppm MiBK exposure, 14C-labeled cholesterol was greater than 3H-labeled cholesterol, indicating that the contribution of de novo cholesterol synthesis to the total cholesterol content of the various isolated hepatocellular fractions was more important than the contribution of intracellular pools. Therefore, increased BCM cholesterol content and enhanced accumulation of newly synthesized cholesterol appear to be involved in MiBK potentiation of Mn-BR-induced cholestasis.