In this paper, we investigate a friendly spectrally shaped radar waveform design that can be used in a spectral band being utilized by one or more communication systems. We specifically consider ...legacy communication systems as opposed to cooperative communication systems to address the ever present problem of legacy technologies. This radar waveform is able to share the spectrum with the existing communication systems such that its detection performance is not compromised while trying to help the legacy systems maintain their own symbol error rates (SERs). We show with various scenarios that the spectrally shaped radar waveform outperforms the traditional wideband pulse waveform in terms of detection performance with the communication signals acting as interference to the radar. Moreover, SERs of the legacy systems employing quaternary phase-shift keying modulation in the presence of the shaped radar waveform (acting as interference) outperform SERs of systems under traditional radar pulse interference. These SERs are very close to theoretical noise-only SERs.
Full-mouth rehabilitation can be challenging due to the complexity of restoring the vertical dimension of occlusion (VDO) and replacing missing teeth. In partially edentulous patients, the concept of ...a bonded composite resin prototype for increasing the VDO has previously been applied through the use of an overlay removable partial denture (RPD) with acrylic resin covering the existing dentition. Unfortunately, this type of prosthesis does not always accurately model the function and phonetics intended for the definitive prostheses, and the esthetic result often is less than ideal. It would be advantageous if direct bonding could be used with the patient's existing RPD to model the increased VDO, but this approach has not been reported in the literature. This case report describes the direct bonding of an existing RPD to create a prototype for increased VDO in a partially edentulous patient with a skeletal Class II malocclusion. The successful outcome has been maintained for more than 1 year.
Noise is defined as "unwanted sound." Aircraft noise is one, if not the most detrimental environmental effect of aviation. It can cause community annoyance, disrupt sleep, adversely affect academic ...performance of children, and could increase the risk for cardiovascular disease of people living in the vicinity of airports. In some airports, noise constrains air traffic growth. This consensus paper was prepared by the Impacts of Science Group of the Committee for Aviation Environmental Protection of the International Civil Aviation Organization and summarizes the state of the science of noise effects research in the areas of noise measurement and prediction, community annoyance, children's learning, sleep disturbance, and health. It also briefly discusses civilian supersonic aircraft as a future source of aviation noise.
Integrated understanding of urban land, groundwater (shallow and deep), baseflow and surface-water quality relationships is required for effective urban water-quality management. Chemical quality ...data from across these media have been collected for the Birmingham (UK) aquifer—River Tame conurbation to assess chemical transport from contaminated land to groundwater to baseflow to surface water. Although metals concentrations were high in soils, low leachability and attenuation caused concentrations in groundwaters and baseflow discharging to surface water to be generally low with only sporadic elevated concentrations attributed to localised point sources. Hydrocarbon VOCs (volatile organic compounds) were similarly absent or at low concentration attributable to their ready natural attenuation. Chlorinated VOCs, however, were widely encountered in groundwater, discharging as baseflow to surface water and impacting surface-water quality. This is attributed to their DNAPL (dense nonaqueous-phase liquid) properties and relative recalcitrance although there was some evidence of biodegradation, albeit insufficient to protect surface water and groundwater abstraction receptors. Some inorganic trends were evident across the various media; nitrate was the most significant quality concern. Generic conclusions are drawn on urban water-quality management and the need for risk-based management strategies to optimise use of urban, sporadically contaminated groundwater in conjunction with surface water highlighted.
NASA Langley Research Center has conducted three groups of studies on human response to sonic booms: laboratory, "inhome," and field. The laboratory studies were designed to: (1) quantify loudness ...and annoyance response to a wide range of shaped sonic boom signatures and (2) assess several noise descriptors as estimators of sonic boom subjective effects. The studies were conducted using a sonic boom simulator capable of generating and playing, with high fidelity, both user-prescribed and recorded boom waveforms to test subjects. Results showed that sonic boom waveform shaping provided substantial reductions in loudness and annoyance and that perceived level was the best estimator of subjective effects. Booms having asymmetrical waveforms were found to be less loud than symmetrical waveforms of equivalent perceived level. Subjective responses to simulated ground-reflected waveforms were fully accounted for by perceived level. The inhome study presented participants with simulated sonic booms played within their normal home environment. The results showed that the equal energy theory of annoyance applied to a variety of multiple sonic boom exposures. The field studies concluded that sonic boom annoyance is greater than that in a conventional aircraft noise environment with the same continuous equivalent noise exposure.
Backgroundmesothelioma mortality rates in GB have increased tenfold over the last four decades and are currently the highest of any country worldwide. The mesothelioma register contains all deaths ...mentioning mesothelioma and includes area of residence and occupation of the deceased.Aimto update descriptive analyses of mortality trends by geographical area and last occupation of the deceased to provide evidence about past sources of mesothelioma risk in the GB population.MethodsStandardised Mortality Ratios (SMRs) were calculated for local and unitary authority areas; Proportional Mortality Ratios (PMRs) were calculated for categories derived from Standard Occupation Classification coding of job titles from death certificates. Temporal trends in SMRs and PMRs over the period 1981–2014 were examined using Generalised Additive Models (GAMs).Resultsthe influence of geographically-specific sources of past asbestos exposure is still seen in recent mesothelioma mortality rates; areas with the highest SMRs in males tend to be those known to contain large industrial sites that used asbestos such as shipyards. However, the strong effect of asbestos exposures in jobs associated with construction work – which would have been geographically less heterogeneous – is seen in analyses by occupation, and temporal trends suggest that such exposures continued for longer than those associated with specific locations.Conclusionsthese results reflect the legacy of widespread industrial asbestos use in GB and particularly emphasise the effect of exposures within the building industry which are likely to have continued after those in specific industries such as shipbuilding and manufacturing were substantially reduced.
ObjectivesWe examined the mortality of a historic cohort of workers in Great Britain with measured blood lead levels (BLLs).MethodsSMRs were calculated with the population of Great Britain as the ...external comparator. Trends in mortality with mean and maximum BLLs and assessed lead exposure were examined using Cox regression.ResultsMean follow-up length among the 9122 study participants was 29.2 years and 3466 deaths occurred. For all causes and all malignant neoplasms, the SMRs were statistically significantly raised. For disease groups of a priori interest, the SMR was significantly raised for lung cancer but not for stomach, brain, kidney, bladder or oesophageal cancers. The SMR was not increased for non-malignant kidney disease but was borderline significantly increased for circulatory diseases, for ischaemic heart disease (IHD) and cerebrovascular disease (CVD). No significant trends with exposure were observed for the cancers of interest, but for circulatory diseases and IHD, there was a statistically significant trend for increasing HR with mean and maximum BLLs.ConclusionsThis study found an excess of lung cancer, although the risk was not clearly associated with increasing BLLs. It also found marginally significant excesses of IHD and CVD, the former being related to mean and maximum BLLs. The finding for IHD may have been due to lead, but could also have been due to other dust exposure associated with lead exposure and possibly tobacco smoking. Further work is required to clarify this and the carcinogenicity of lead.
In this paper, we investigate spectrally adaptive radar transmit waveform design and its effects on an active communication system. We specifically look at waveform design for point targets. The ...transmit waveform is optimized by accounting for the modulation spectrum of the communication system while trying to efficiently use the remaining spectrum. With the use of spectrally-matched radar waveform, we show that the SER detection performance of the communication system is minimally affected compared to the SER performance with a classical non-adaptive pulsed radar waveform. Moreover, we show the detection performance of the adaptive waveform is less impacted by the active communication compared to that of the pulsed radar waveform design. In other words the radar is able to coexist with a friendly communication system and thus share the spectrum with a friendly communication system.
Objectives We report on the first ever analysis of a UK cohort of workers with blood lead level measurements that was assembled in the late 1970s. Method As an alternative to mean and maximum blood ...lead levels, we carried out an exposure assessment that assigned workers to high, medium or low exposure to lead. We additionally assessed whether workers would be exposed to an important level of relevant co-carcinogens. Results 3466 deaths were observed among 7770 men and 1352 women. The SMRs for all causes (109, 95% CI 105–112) and all malignant neoplasms (113,107–120) were significantly raised. SMRs for oesophageal, stomach, bladder, brain and kidney cancer and non-malignant kidney disease were not raised, but were raised for lung cancer (142,129–157). The SMR for circulatory diseases (105,99–100) was of borderline significance. No trends were observed for mean or maximum blood lead level or assessed lead exposure for any of the cancers of a priori interest, but a significant association was found for circulatory diseases (ischaemic heart disease) with mean and maximum blood lead level. Conclusions The excess of lung cancer is possibly to be due to tobacco smoking. This study provides strong evidence to support an association between increased lead exposure and increased risk of ischaemic heart disease mortality. The study is, however, limited by the lack of complete occupational histories for the included participants.
PDF
