Wind velocity effects on sampling rate of NO2 badge.

The effects of wind velocity on a sampling rate of a nitrogen dioxide (NO2) diffusive badge were experimentally determined using a turntable. The use of a turntable permits the collection of the large amounts of data that are needed for statistically reliable results at several wind velocities in one experiment. The regression model for the wind effect determined by these experiments was closely correlated with data previously gathered from experiments using wind tunnels. Experiments at two different relative humidities, 35% and 60%, were performed and analyzed by a simple least square regression model. A multi-regression model containing two independent variables, wind velocity and relative humidity, also was developed. The multi-regression model was useful at relative humidity between 20% and 60% and wind velocity between 0 and 7 meter per second (m/sec).     

Proposed modification to the inhalable aerosol convention applicable to realistic workplace wind speeds

The current convention for sampling inhalable aerosols was based on several mannequin studies performed in wind tunnels at wind speeds between 0.5 and 4 m s(-1). In reality, as we now know, the wind speed in most modern indoor working environments is generally at or below ～0.2 m s(-1). Inhalability studies performed in calm air aerosol chambers have shown that human aspiration efficiency at essentially zero wind speed is not consistent with the existing inhalable aerosol convention, calling into question the universal applicability of the current standard. More recently, experiments were carried out in a new hybrid wind tunnel-calm air chamber at more representative workplace wind speeds, between ～0.1 and 0.5 m s(-1), to fill in this knowledge gap. Comparing these new data to both the existing inhalable aerosol convention and a recently proposed alternative for low wind movement suggests that, while the existing inhalable aerosol convention remains appropriate for wind speeds above ～0.2 m s(-1), the modified version is more appropriate for the range below ～0.2 m s(-1).     

Effects of wind speed on aerosol spray penetration in adult mosquito bioassay cages

Bioassay cages are commonly used to assess efficacy of insecticides against adult mosquitoes in the field. To correlate adult mortality readings to insecticidal efficacy and/or spray application parameters properly, it is important to know how the cage used in the bioassay interacts with the spray cloud containing the applied insecticide. This study compared the size of droplets, wind speed, and amount of spray material penetrating cages and outside of cages in a wind tunnel at different wind speeds. Two bioassay cages, Center for Medical, Agricultural and Veterinary Entomology (CMAVE) and Circle, were evaluated. The screen materials used on these cages reduced the size of droplets, wind speed, and amount of spray material inside the cages as compared to the spray cloud and wind velocity outside of the cages. When the wind speed in the dispersion tunnel was set at 0.6 m/sec (1.3 mph), the mean wind speed inside of the CMAVE Bioassay Cage and Circle Cage was 0.045 m/sec (0.10 mph) and 0.075 m/sec (0.17 mph), respectively. At air velocities of 2.2 m/sec (4.9 mph) in the dispersion tunnel, the mean wind speed inside of the CMAVE Bioassay Cage and Circle Cage was 0.83 m/sec (1.86 mph) and 0.71 m/sec (1.59 mph), respectively. Consequently, there was a consistent 50-70% reduction of spray material penetrating the cages compared to the spray cloud that approached the cages. These results provide a better understanding of the impact of wind speed, cage design, and construction on ultra-low-volume spray droplets.     

双位定风量装置的应用分析

文章介绍了在洁净手术部净化空调系统中的双位定风量装置，如何在手术室处于使用时（动态）和值机时（静态）起到其应有的作用。简述了设定双位定风量装置的两种恒定风量。     

How the factoid of wind turbines causing ‘vibroacoustic disease’ came to be ‘irrefutably demonstrated’

Objective : In recent years, claims have proliferated in cyberspace that wind turbines cause a large variety of symptoms and diseases. One of these, “vibroacoustic disease” (VAD) is frequently mentioned. The aim of this study is to examine the quality of the evidence on how VAD came to be associated with wind turbine exposure by wind farm opponents. Methods: Searches of the web (Google advanced) and major research databases for papers on VAD and wind turbines. Self‐citation analysis of research papers on VAD. Results: Google returned 24,700 hits for VAD and wind turbines. Thirty‐five research papers on VAD were found, none reporting any association between VAD and wind turbines. Of the 35 papers, 34 had a first author from a single Portuguese research group. Seventy‐four per cent of citations to these papers were self‐citations by the group. Median self‐citation rates in science are around 7%. Two unpublished case reports presented at conferences were found asserting that VAD was “irrefutably demonstrated” to be caused by wind turbines. The quality of these reports was abject. Conclusions: VAD has received virtually no scientific recognition beyond the group who coined and promoted the concept. There is no evidence of even rudimentary quality that vibroacoustic disease is associated with or caused by wind turbines. Implications: The claim that wind turbines cause VAD is a factoid that has gone ‘viral’ in cyberspace and may be contributing to nocebo effects among those living near turbines.     

Impact of wind turbine noise in the Netherlands

The Dutch government aims at an increase of wind energy up to 6 000 MW in 2020 by placing new wind turbines on land or offshore. At the same time, the existing noise legislation for wind turbines is being reconsidered. For the purpose of establishing a new noise reception limit value expressed in L den , the impact of wind turbine noise under the given policy targets needs to be explored. For this purpose, the consequences of different reception limit values for the new Dutch noise legislation have been studied, both in terms of effects on the population and regarding sustainable energy policy targets. On the basis of a nation-wide noise map containing all wind turbines in The Netherlands, it is calculated that 3% of the inhabitants of The Netherlands are currently exposed to noise from wind turbines above 28 dB(A) at the faηade. Newly established dose-response relationships indicate that about 1500 of these inhabitants are likely to be severely annoyed inside their dwellings. The available space for new wind turbines strongly depends on the noise limit value that will be chosen. This study suggests an outdoor A-weighted reception limit of L den = 45 dB as a trade-off between the need for protection against noise annoyance and the feasibility of national targets for renewable energy.     

A Survey of Wind Speeds in Indoor Workplaces

The applicability of the inhalable convention for sampling aerosols relies on its being a valid model for typical sampling environments. The current convention is based on measurements carried out in external wind speeds between 1 and 4 · m= s^-1 . However these measurements show a degree of wind speed dependence, and it is uncertain at present how valid the convention is for describing human aspiration efficiency outside these wind speed limits. Following concerns that wind speeds in many indoor workplaces may be significantly below this range, measurements have been made in 55 work areas covering a wide range of workplaces. Measurements have concentrated on ‘background’ wind speeds where the influence of specific air movement sources is minimised. The pooled wind speed measurements show a highly skewed distribution with an arithmetic mean of approximately 0.3 ·m= s^-1 . Approximately 85% of all individual measurements were below this mean value. No obvious correlation was found between wind speed distribution parameters and industry type, room size or ventilation type. A limited number of comparisons were made between static anemometers and devices mounted on workers. It was found that modal wind speeds experience by workers were typically 0.05 ·m= s^-1 higher than those measured using a static anemometer. These measurements agreed well with previously published data for similar work- places as well as houses. Crown copyright ©1998 Published by Elsevier Science Ltd on behalf of British Occupational Hygiene Society.     

Aerosol penetration relative to sentinel cage configuration and orientation

Aerosol movement into 4 different sentinel cage configurations at 0 degrees, 30 degrees and 60 degrees orientation relative to the aerosol flow in a wind tunnel was studied using a quartz crystal microbalance cascade impactor. The data suggest that a cylinder, screened on all sides, with the longitudinal axis perpendicular to the ground would provide a consistent cage profile to the wind regardless of wind direction changes and thereby reduce aerosol environment variability among cages.     

Performance study of personal inhalable aerosol samplers at ultra-low wind speeds

The assessment of personal inhalable aerosol samplers in a controlled laboratory setting has not previously been carried out at the ultra-low wind speed conditions that represent most modern workplaces. There is currently some concern about whether the existing inhalable aerosol convention is appropriate at these low wind speeds and an alternative has been suggested. It was therefore important to assess the performance of the most common personal samplers used to collect the inhalable aerosol fraction, especially those that were designed to match the original curve. The experimental set-up involved use of a hybrid ultra-low speed wind tunnel/calm air chamber and a rotating, heating breathing mannequin to measure the inhalable fraction of aerosol exposure. The samplers that were tested included the Institute of Occupational Medicine (IOM), Button, and GSP inhalable samplers as well as the closed-face cassette sampler that has been (and still is) widely used by occupational hygienists in many countries. The results showed that, down to ～0.2 m s(-1), the samplers matched the current inhalability criterion relatively well but were significantly greater than this at the lowest wind speed tested. Overall, there was a significant effect of wind speed on sampling efficiency, with lower wind speeds clearly associated with an increase in sampling efficiency.     

A wind tunnel bioassay system for screening mosquito repellents

A wind tunnel bioassay system to screen mosquito repellents is described. A wind tunnel is utilized to exploit the upwind flight response of host-seeking mosquitoes. Mosquitoes within the wind tunnel are activated with human breath, fly upwind, and land on heated chick skins. This behavioral sequence results in a consistently high percentage of the test population approaching repellent or control stimuli. The bioassay system is calibrated with diethyl methylbenzamide against Aedes aegypti and demonstrates a reproducible dose-response relationship. The persistence of diethyl methyl benzamide after a 1-h period is also recorded. The design of the bioassay system permits simultaneous, independent testing of 3 candidate repellents. The wind tunnel bioassay system is compared to other techniques for evaluating mosquito repellents.     

风力发电场职业性危害风险辨识与防控措施要点

目的 提出风力发电场的职业病防控措施,为行政监管部门分类监管提供参考,为用人单位职业病防治管理提供指导。方法 在工程分析的基础上,系统地辨识了风力发电场可能存在或产生的主要职业病危害因素及其分布情况。结果 风力发电场可能存在或产生的职业病危害因素主要为工频电磁场和六氟化硫。结论 风电场应该从多个方面加强管理与防护,切实保证劳动者的人身健康与权益。     

Wind turbine noise, annoyance and self-reported health and well-being in different living environments

Objectives

To evaluate the prevalence of perception and annoyance due to wind turbine noise among people living near the turbines, and to study relations between noise and perception/annoyance, with focus on differences between living environments.

Methods

A cross‐sectional study was carried out in seven areas in Sweden across dissimilar terrain and different degrees of urbanisation. A postal questionnaire regarding living conditions including response to wind turbine noise was completed by 754 subjects. Outdoor A‐weighted sound pressure levels (SPLs) were calculated for each respondent. Perception and annoyance due to wind turbine noise in relation to SPLs was analysed with regard to dissimilarities between the areas.

Results

The odds of perceiving wind turbine noise increased with increasing SPL (OR 1.3; 95% CI 1.25 to 1.40). The odds of being annoyed by wind turbine noise also increased with increasing SPLs (OR 1.1; 95% CI 1.01 to 1.25). Perception and annoyance were associated with terrain and urbanisation: (1) a rural area increased the risk of perception and annoyance in comparison with a suburban area; and (2) in a rural setting, complex ground (hilly or rocky terrain) increased the risk compared with flat ground. Annoyance was associated with both objective and subjective factors of wind turbine visibility, and was further associated with lowered sleep quality and negative emotions.

Conclusion

There is a need to take the unique environment into account when planning a new wind farm so that adverse health effects are avoided. The influence of area‐related factors should also be considered in future community noise research.Wind power is a relatively new form of electricity generation that has a low impact on the environment compared with other power sources¹ and is also favoured by the public, at least by those who do not have a wind turbine project in their own community.² One disadvantage is the noise that inevitably emits from the rotor blades. Typically, sound power levels of a modern wind turbine range from 98–104 dB(A) at a wind speed of 8 m/s, which result in 33–40 dB(A) at a dwelling 500 m away, though this depends on meteorological and ground conditions. Sound pressure levels (SPLs) of this low magnitude are not considered a problem when it comes to other sources of community noise, such as road traffic and aircraft, but two circumstances increase the risk of negative perception of the sound from wind turbines: the sound character and the localisation. The sound is amplitude modulated by the pace of the rotor blades, which gives a rhythmical swishing sound. Such sounds are known to be more easily perceived than an even sound³ and possibly also are more negatively appraised. In a rural environment the turbines are prominent and, because the rotor blades move in an otherwise fairly still environment, they are likely to draw visual attention.We do not know the prevalence of perception and possible effects of wind turbine noise at a generalised level because only a few studies have been carried out. In an investigation of the impact of wind turbines on people living near them in a flat landscape, a dose‐response relation between A‐weighted SPL and annoyance due to wind turbine noise was found.⁴ The relation was, however, moderated by the respondents'' attitude to the visual impact of the turbines on the landscape. In a Danish study, also carried out in a flat landscape, the angle from the subject to the hub of the wind turbine was more correlated to perception of the noise than SPL was.⁵ There are therefore reasons to believe that the prevalence of noise annoyance may be influenced by the variation in visibility of the wind turbines between different landscapes, such as a flat landscape and a hilly ground.In one study, interviews with 15 subjects revealed additional possible associations between landscape and perception of wind turbine noise.⁶ The subjects'' personal values relating to the living environment appeared to influence how the noise from the wind turbines was perceived. Some, who considered the countryside as a place for economic growth and technical achievements, were indifferent to noise exposure from the wind turbines. Others, who emphasised that the countryside should be a quiet and peaceful place for relaxation, felt that the noise intruded their privacy and hence had a negative impact on their quality of life. People in the latter category would presumably seek living environments consistent with their needs, and may therefore be overrepresented in areas they perceive as quiet and peaceful. It could therefore be hypothesised that exposure from wind turbines would be more negatively appraised in an area that is perceived as unspoiled than in an area where several human activities take place.     

A recirculation aerosol wind tunnel for evaluating aerosol samplers and measuring particle penetration through protective clothing materials

A recirculation aerosol wind tunnel was designed to maintain a uniform airflow and stable aerosol size distribution for evaluating aerosol sampler performance and determining particle penetration through protective clothing materials. The oval-shaped wind tunnel was designed to be small enough to fit onto a lab bench, have optimized dimensions for uniformity in wind speed and particle size distributions, sufficient mixing for even distribution of particles, and minimum particle losses. Performance evaluation demonstrates a relatively high level of spatial uniformity, with a coefficient of variation of 1.5-6.2% for wind velocities between 0.4 and 2.8 m s(-1) and, in this range, 0.8-8.5% for particles between 50 and 450 nm. Aerosol concentration stabilized within the first 5-20 min with, approximately, a count median diameter of 135 nm and geometric standard deviation of 2.20. Negligible agglomerate growth and particle loss are suggested. The recirculation design appears to result in unique features as needed for our research.     

Weather and the risk of sudden infant death syndrome: the effect of wind

STUDY OBJECTIVE—To examine and identify relations between sudden infant death syndrome (SIDS) and wind, particularly the föhn wind, in Christchurch, New Zealand.
DESIGN—A retrospective epidemiological study combining details of regional hourly meteorological variables and reported SIDS cases.
SETTING—Christchurch, New Zealand, between 1968 and 1997 inclusively.
PARTICIPANTS—All 646 infants reported as dying from SIDS within the greater Christchurch region.
MAIN RESULTS—Analysis of 1968-1989 data revealed nine wind variables significantly related to SIDS. When compared with corresponding variables calculated over the 1990-1997 period, only the northerly wind on the day of death and the southerly wind three days before a SIDS death had estimated associations with similar effect size and sign. However, both these variables had confidence intervals that included unity.
CONCLUSIONS—No evidence was found to suspect that föhn winds influenced SIDS occurrence. The relations identified between SIDS incidence and wind, after controlling for the effects of temperature and trend, were tenuous and relatively small. More data are necessary to substantiate whether northerly winds on the day of death or southerly winds occurring three days before a death are truly associated with SIDS. It seems that wind has little, if any effect on SIDS incidence in Christchurch.


     

城市生活垃圾好氧堆肥工艺强制通风设计计算

通过对城市生活垃圾综合处理技术中好氧堆肥工艺的强制通风系统所需风量及管路压力损失的分析，提出了风量和压力损失的计算方法，为选择风机提供依据。     

生活垃圾填埋作业面恶臭影响的气象因素分析

利用前期研究得到的作业面恶臭源强数据,以某一大型填埋场作业面为研究对象,采用面源高斯扩散模型分析了作业面在不同季节、风速和稳定度等气象条件下对周围恶臭影响情况.结果表明：不同季节气温和气象稳定度对填埋作业面的恶臭影响范围作用很大,而风速的影响表现为小风速时影响范围大,而大风速时尽管散发源强增大,但由于扩散输送条件变好,恶臭的影响范围反而变小.对于填埋作业面达10000m2的填埋场,在气温大于26℃、稳定度E、风速持续小于3 m/s的气象条件下,作业面对下风向的恶臭影响距离可达8 km以上.     

Hospital admissions for asthma and acute bronchitis in El Paso, Texas: do age, sex, and insurance status modify the effects of dust and low wind events?

Background

El Paso County (Texas) is prone to still air inversions and is one of the dust “hot spots” in North America. In this context, we examined the sub-lethal effects of airborne dust and low wind events on human respiratory health (i.e., asthma and acute bronchitis) between 2000 and 2003, when 110 dust and 157 low wind events occurred. Because environmental conditions may not affect everyone the same, we explored the effects of dust and low wind within three age groups (children, adults, and the elderly), testing for effect modifications by sex and insurance status, while controlling for weather and air pollutants.

Methods

We used a case-crossover design using events matched with referent days on the same day-of-the-week, month, and year with conditional logistic regression to estimate the probability of hospital admission, while controlling for apparent temperature (lag 1), nitrogen dioxide, and particulate matter of 2.5 μm or less.

Results

Children (aged 1–17) were 1.19 (95% confidence interval: 1.00–1.41) times more likely to be hospitalized for asthma three days after a low wind event, and 1.33 (95% CI: 1.01–1.75) times more likely to be hospitalized for acute bronchitis one day after a dust event than on a clear day. Girls were more sensitive to acute bronchitis hospitalizations after dust events (1.83, 95% CI: 1.09–3.08) than boys, but less sensitive than boys to acute bronchitis hospitalizations after low wind events (0.68, 95% CI: 0.46−1.00). We found general trends with regard to dust and low wind events being associated with increased odds of hospitalization for asthma and bronchitis amongst all ages and adults (aged 18–64). Adults covered by Medicaid and adults without health insurance had higher risks of hospitalization for asthma and acute bronchitis after both low wind and dust events.

Conclusions

Results suggest that there were respiratory health effects associated with dust and low wind events in El Paso, with stronger impacts among children and poor adults. Girls and boys with acute bronchitis were differentially sensitive to dust and low wind events.     

Directional frequency correction for the star meteorological joint frequency computer program

Atmospheric dispersion computer programs are widely used to simulate air and surface exposures from airborne and deposited radionuclides. For longer-term emissions (i.e., occurring for a year or longer), many of these models use joint frequency tables, which summarize the frequency of occurrence of specific ranges of wind speed and direction as a function of stability categories to define the atmospheric dispersion conditions. This paper addresses directional limitations of a computer code, STAR (STability ARray), that has been historically used to generate these joint frequency tables. As part of an effort to provide an updated version of the STAR code, directional limitations were found stemming from the manner in which the reported direction data are stored in joint frequency data tables. The STAR code provides tabular frequency summaries based on sixteen 22.5-degree wind direction sectors. Surface observation data in the CD-144 format from the United States National Oceanographic and Oceanic Administration (NOAA) is read by the STAR program. For 1964 and later years the wind direction has been reported in CD-144 datasets as 10-degree increments instead of the 22.5-degree sector direction codes used in prior years. When 10-degree data are input, the process by which the STAR code puts each wind direction occurrence into the 22.5-degree sectors results in a consistent positive bias for cardinal direction sectors (north, south, east, and west), and a consistent negative bias for all the other sectors. Individual entries in the joint frequencies summaries with high wind frequencies tend to be overestimated by up to about 30% or underestimated down to about -10%. A larger range of changes is seen for entries with lower wind frequencies. To avoid these errors, it is recommended that joint frequencies generated by the STAR program be checked for this directional bias. If the NOAA observational data are for 1964 or later years and generated by the original EPA STAR program, it is likely that the bias will be in the dataset. To be certain, it is best to regenerate the STAR data summary using a revised version of the STAR program (STARR) or an alterative program that better handles the binning of wind directions.     

上海市吴淞工业区PM10和18种无机元素污染状况调查

[目的]了解吴淞工业区空气中PM10和无机元素污染状况。[方法]在上海市吴淞工业区选择一个监测点，使用自动滤式颗粒物收集仪(automatic cartridge collection unit，ACCU)系统进行为期3个月、8个不同风向的PM10采样。对采集的样品进行了PM10浓度分析，并使用质子激发X荧光发射(proton-induced X-ray emission，PIXE)方法分析了18种无机元素浓度。[结果]由分析结果可知，在8个不同风向，PM10和绝大部分无机元素有着一个低浓度和高浓度风向区域，变化趋势基本相同，变化范围差异较大，有1至3个风向对该测点PM10和绝大部分无机元素浓度水平有着明显影响。PM10最高和最低浓度分别出现在西北-北(NW-N)和东-东南(E-SE)风向，最高浓度是最低浓度的3．9倍；18个无机元素最高与最低浓度之比的范围从2．55到35．30，且大部分无机元素的最高浓度出现在南-西南(S-SW)或西南-西(SW-W)风向，最低浓度出现在东北-东(NE-E)风向。[结论]各风向的浓度水平与采样点周围居民住宅区、交通道路和不同类型工厂等分布情况明显相关。