Optimization of one-step pelletization technology of Jiuwei Xifeng granules by response surface methodology / 中国中药杂志

Using the qualified rates of particles as the evaluation indexes, the impact tactors of one-step pelletization technology of Jiuwei Xifeng granules were selected from six factors by the Plackett-Burman experimental design and the levels of non-significant factors were identified. According to the Plackett-Burman experimental design, choosing the qualified rates of particles and angle of repose as the evaluation indexes, three levels of the three factors were selected by Box-Behnken of central composite design to optimize the experimental. The best conditions were as follows: the fluid extract was sprayed with frequency of 29 r . min-1, inlet air temperature was 90 °C, the frequency of fan was 34 Hz. Under the response surface methodology optimized scheme, the average experimental results are similar to the predicted values, and surface methodology could be used in the optimization of one-step pelletization for Chinese materia medica.

Effect of septoplasty or in combination with out fracture of the inferior turbinate on the airflow field and nasal airway / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To explore the effect of septoplasty or in combination with out fracture of the inferior turbinate in patients with nasal septum deviation on the airflow field and the nasal airway structure.</p><p><b>METHODS</b>Six patients with nasal septum deviation underwent spiral CT imaging scans before surgery and during the follow-up. The 3D finite element meshes of the nasal airway were developed from the above CT scans. Given three preconditions, the nasal airflow fields were described by the Navier-Stokes and continuity equations at the inspiratory flow rate of 12 L/min. The whole airflow patterns were obtained and then compared with the airflow filed and airway structure changes before and after surgery. SPSS 12.0 software was used to analyze the data.</p><p><b>RESULTS</b>Before surgery, area of the common airway and the middle and ventral medial regions in the concave side were (1.61 ± 0.18), (0.40 ± 0.10), (0.40 ± 0.14) cm(2) respectively, and those of convex side were (1.30 ± 0.18), (0.33 ± 0.05), (0.36 ± 0.10) cm(2) respectively. The differences between both sides were of no statistical significance (Z value was 1.782, 1.363, 0.526 respectively, all P > 0.05). Airflow of the above airways were (361 ± 68), (131 ± 25), (100 ± 28) ml respectively in concave side and (178 ± 33), (59 ± 26), (59 ± 18) ml respectively in convex side, which differences were significant statistically (Z value were 2.207, 2.201, 2.201 respectively, all P < 0.05). The inferior turbinate in concave side [(0.93 ± 0.10) cm] was statistically (Z = 2.214, P < 0.05) bigger than that in convex side [(0.58 ± 0.12) cm] before surgery. The airflow fields were in disorder in both ill-airways. After surgery, area of the common airway was (2.55 ± 0.44) cm(2) in concave side and (2.20 ± 0.72) cm(2) in convex side respectively, and area of the middle and ventral medial regions in the convex side were (0.58 ± 0.13), (0.81 ± 0.26) cm(2) respectively, which differences were of significance statistically when comparing to areas before surgery (Z value were 2.201, 2.201, 2.201, 2.201, P < 0.05). The airflow passed through nasal airway orderly in both sides. But the thickness of inferior turbinate was (0.73 ± 0.08) cm in concave side after surgery, which difference was significant statistically in comparison to that before surgery (Z = 2.264, P < 0.05). Consequently, nasal resistance decreased from (0.41 ± 0.03) kPa×L(-1)×s(-1) to (0.16 ± 0.01) kPa×L(-1)×s(-1) after surgery, the difference was significantly (Z = -2.207, P = 0.027).</p><p><b>CONCLUSION</b>Septoplasty or in combination with out fracture of the inferior turbinate, followed by the self-adaptation consecutively, could improve the airway and breathing capacity of the nose.</p>

Numerical simulation study on effects of ambient temperature on airflow in the nasal cavity / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To study the aerodynamics of the normal human nasal cavity under different ambient temperatures.</p><p><b>METHODS</b>Based on CT scanning, a model of a healthy adult's nasal cavity was established using computational fluid dynamics software from Fluent. Airflow in this model was simulated and calculated at ambient temperatures of 0 °C, 24 °C, and 37 °C during periodic breathing.</p><p><b>RESULTS</b>Ambient temperature only had an impact on the temperature in the nasal cavity during the inspiratory phase, and the temperature distribution was not symmetrical in the inspiratory acceleration and deceleration phases. The ambient temperature significantly affected airflow speed in main nasal passages during the inspiratory process, but had little impact on flow status (proportion and streamline of airflow in different nasal passages). Temperature differences increased the irregular air movement within sinuses. The anterior nasal segment, including the area between the valve and the head of the middle turbinate, was the most effective part of the nasal airway in heating the ambient air.</p><p><b>CONCLUSIONS</b>Our findings describe the effects of ambient temperature on airflow parameters in the nasal cavity within a single respiratory cycle. This data is more comprehensively and accurately to determine the relationship between nasal cavity aerodynamics and physiological functions.</p>

Aerodynamics study on pressure changes inside pressure-type whole-body plethysmograph produced by flowing air / 生理学报

When using pressure-type plethysmography to test lung function of rodents, calculation of lung volume is always based on Boyle's law. The precondition of Boyle's law is that perfect air is static. However, air in the chamber is flowing continuously when a rodent breathes inside the chamber. Therefore, Boyle's law, a principle of air statics, may not be appropriate for measuring pressure changes of flowing air. In this study, we deduced equations for pressure changes inside pressure-type plethysmograph and then designed three experiments to testify the theoretic deduction. The results of theoretic deduction indicated that increased pressure was generated from two sources: one was based on Boyle's law, and the other was based on the law of conservation of momentum. In the first experiment, after injecting 0.1 mL, 0.2 mL, 0.4 mL of air into the plethysmograph, the pressure inside the chamber increased sharply to a peak value, then promptly decreased to horizontal pressure. Peak values were significantly higher than the horizontal values (P<0.001). This observation revealed that flowing air made an extra effect on air pressure in the plethysmograph. In the second experiment, the same volume of air was injected into the plethysmograph at different frequencies (0, 0.5, 1, 2, 3 Hz) and pressure changes inside were measured. The results showed that, with increasing frequencies, the pressure changes in the chamber became significantly higher (P<0.001). In the third experiment, small animal ventilator and pipette were used to make two types of airflow with different functions of time. The pressure changes produced by the ventilator were significantly greater than those produced by the pipette (P<0.001). Based on the data obtained, we draw the conclusion that, the flow of air plays a role in pressure changes inside the plethysmograph, and the faster the airflow is, the higher the pressure changes reach. Furthermore, the type of airflow also influences the pressure changes.

Effect of barn ventilation on blood gas status and some physiological traits of dairy cows.

Twenty Holstein friesian and Brown swiss cows were used to investigate the effect of insufficient in barn ventilation on blood gas status and some physiological traits of the cows. Animals were kept in mechanically ventilated barn in stall barn (I); and the ventilation funnels of the barn were closed to simulate traditional habits of the region's breeders (II); then cows were transfered open-shed barn (III). For each experimental of 10 days period, respiration and pulse rates and blood gas of animals were measured. Temperature, relative humidity, CO2 and NH3 concentrations were recorded in each barns. In mechanically ventilated barn, climatic and atmospheric gas was in normal ranges for the cows but in unventilated barn they were at the upper levels. In experiment II, blood pH was decreased without pCO2 change. The highest blood pO2 and HCO3(-) levels were found when the animals were kept in open-shed barn (III). Measured parameters were not influenced by breed of the cows. Blood pH, pO2 HCO3(-), respiration and pulse rates of the cows were significantly affected by barn types (p < 0.05 and p < 0.01). Respiration and pulse rates were higher in inadequate (II) barn conditions than those of open-shed. Higher levels of gases, especially carbon dioxide, in the unventilated barn significantly influenced biological parameters of cows. It is concluded that poor ventilation caused considerable changes in physiologic parameters of the cows and can potentially affect animal health and production.

Effects of drop acceleration and deceleration on particle capture in a cross-flow gravity tower at intermediate drop Reynolds numbers.

Cross-flow gravity towers are particle scrubbing devices in which water is sprayed from the top into particle-laden flow moving horizontally. Models for predicting particle capture assume drops traveling at terminal velocity and potential flow (ReD > 1000) around it, however, Reynolds numbers in the intermediate range of 1 to 1000 are common in gravity towers. Drops are usually injected at velocities greater than their terminal velocities (as in nozzles) or from near rest (perforated tray) and they accelerate/decelerate to their terminal velocity in the tower. Also, the effects of intermediate drop Reynolds number on capture efficiency have been simulated for (a) drops at their terminal velocity and (b) drops accelerating/decelerating to their terminal velocity. Tower efficiency based on potential flow about the drop is 40%-50% greater than for 200 mm drops traveling at their terminal velocity. The corresponding values for 500 mm drops are about 10%-20%. The drop injection velocity is important operating parameter. Increase in tower efficiency by about 40% for particles smaller than 5 mm is observed for increase in injection velocity from 0 to 20 m/s for 200 and 500mm drops.

Use of wind data for estimating horizontal dilution potential of atmosphere.

In this study, a new methodology is suggested for estimating horizontal dilution potential of an area using wind data. The mean wind speed and wind direction variation are used as a measure of linear and angular spread of pollutants in the atmosphere. A formula is developed for estimating the potential of horizontal spread of pollutants in an area wherein only the wind speed and direction are used. The methodology is further applied to monitor wind data of one year. It is found that there is a very smooth variation of horizontal dilution potential over a year with limited dilution during post monsoon period and a high dilution in pre monsoon period.

Self-reported Cabin Environment and Work-related Musculoskeletal Disorders (WMSDs) among Female Flight Attendants on Long-haul International Flights / 항공우주의학회지

Physical environmental factors have been found to increase the risk for work-related musculoskeletal disorders (WMSDs) in a variety of occupations. To date little is known about the influence of physical environmental factors in the cabin of an airplane on WMSDs among flight attendants. The purpose of this study was to examine the relationship between self-reported physical environment factors in the cabin and WMSDs in the neck, shoulder, upper back, and lower back among U.S. female flight attendants on long-haul international flights. A cross-sectional mailed survey was conducted with 185 female fight attendants working on long-haul international flights. The physical environment measure included 12 items regarding cabin-air quality, noise, lighting, and whole-body vibration. WMSDs were measured by the Nordic Musculoskeletal Questionnaire and the National Institute for Occupational Safety and Health Symptom Survey. The percentage of flight attendants who had WMSDs for each body region varied from 31% to 54%. The majority (>80%) of the flight attendants often or always experienced low humidity, stuffy air, and little air movement while working in the cabin. Being frequently exposed to unfavorable cabin environmental factors increased the risk of neck (OR=2.89), shoulder (OR=2.96), and upper-back WMSDs (OR=2.14). Cabin environmental factors should be taken into account when examining the risk factors for WMSDs.

Aerial and tidal transport of mosquito control pesticides into the Florida Keys National Marine Sanctuary

This project was undertaken as the initial monitoring program to determine if mosquito adulticides applied along the Florida Keys cause adverse ecological effects in the Florida Keys National Marine Sanctuary (FKNMS). The study monitored the distribution and persistence of two mosquito adulticides, permethrin and dibrom (naled), during three separate routine applications by the Florida Keys Mosquito Control District. The approach was to determine if toxic concentrations of the pesticides entered the FKNMS by aerial drift or tidal transport. The amount of pesticide entering the FKNMS by way of aerial drift was monitored by collection on glass fiber filter pads, set on floats in a grid pattern on either side of the FKNMS. Permethrin was recovered from filter pads on the leeward side for each of the three applications, ranging from 0.5 to 50.1 microg/m(2) throughout the study. Tidal current transport was monitored by collection of surface and subsurface water samples at each grid site. Tidal transport of naled and dichlorvos (naled degradation product) was apparent in the adjacent waters of the FKNMS. These compounds were detected in subsurface, offshore water at 0.1 to 0.6 microg/1, 14 hr after application. Permethrin was not detected in offshore water samples; however, concentrations ranging from 5.1 to 9.4 microg/l were found in surface water from the canal system adjacent to the application route. Comparison of the observed environmental concentrations with toxicity data (permethrin LC-50, 96 hr for Mysidopsis bahia = 0.02 microg/l) indicated a potential hazard to marine invertebrates in the canals with possible tidal transport to other areas

Prediction and analysis model of temperature and its application to a natural ventilation multi-span plastic greenhouse equipped with insect-proof screen / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The natural ventilation widely used in greenhouses has advantages of saving energy and reducing expense. In order to provide information for climate control of greenhouse, a model was developed to predict the variation of air temperature in the naturally ventilated greenhouse equipped with insect-proof screen. Roof ventilation and combined roof and sidewall ventilation were considered in the model. This model was validated against the results of experiments conducted in the greenhouse when the wind was parallel to the gutters. The model parameters were determined by the least squares method. In the used model, effects of wind speed and window opening height on the air temperature variation were analyzed. Comparison between two types of ventilation showed that there existed a necessary ventilation rate which results in air temperature decrease in natural ventilation under special climatic conditions. In our experiments when wind speed was less than 3.2 ms(-1), wind had a more gradual effect on greenhouse temperature for roof ventilation, compared with combined roof and sidewall ventilation, which had greater air temperature decrease than roof ventilation only.

Air movement, gender and risk of sick building headache among employees in a Jakarta office.

Even though office buildings are usually equipped with ventilation system or air conditioning to create a comfortable working environment, yet there is still found a number of sick building syndrome (SBS) symptoms. One of the symptoms of SBS is SBS headache. Therefore, it is crucial to identify risk factors related to SBS headache. Cases were subjects who have suffered SBS headache, and controls were subjects who did not suffered headache for the last one month. Cases and controls were selected through a survey on all of employees in the said office during the period of May to August 2002. Total respondents were 240 employees including 36 people suffered SBS headache (15%). Compared to the normal air movement, faster air movement decreased the risk of SBS headache by 57% [adjusted odds ratio (OR) = 0.43; 95% confidence intervals (CI): 0.19-0.95]. Female employees, compared to the males ones, had a higher risk of getting SBS headache by almost three times (adjusted OR = 2.96: 95% CI: 1.29-6.75). Employees who had breakfast irregularly, had a lower risk to SBS headache than those who have breakfast regularly (adjusted OR=0.31; 95% CI: 0.09-0.84). Temperature, humidity and smoking habits were not noted correlated to SBS headache. Female workers had greater risk of suffering SBS headache. In addition slower air movement increased the risk of SBS headache. Therefore, it is recommended to improve the progress of air in order to reduce the risk of SBS headache, especially for female workplace.

Effect of harvesting operations on fungal spore populations of air.

Agricultural practices such as harvesting of crops cause the pathogens to disseminate in abundance and may cause diseases, like skin and respiratory allergies in an epidemic form. Also the farm workers were likely to be exposed repeatedly to high doses of fungal spore allergens from crop harvesting operations. At Srikakulam, located in North Coastal Andhra Pradesh, India, the major crops grown include rice and sugarcane. As part of a major study on the airspora of Srikakulam the effect of harvesting of these two crops on aerial spore concentrations was studied through rotorod trappings. The results showed an enormous increase in the spore load not only of the fungi pathogenic to the crop but also saprophytic fungi while the crop was harvested. The increase in the pathogenic fungal spores was large as evidenced by the increase of the rice crop pathogens as Trichoconis padwickii, Ustilaginoidea virens, Cochilobolus oryzae etc.

Sick Building Syndrome in Office Workers / 대한산업의학회지

A cross-sectional study was conducted to evaluate the relationship between sick building syndrome (SBS) and the factors affecting SBS among 90 office workers. The study consisted of 1) a review of previous environmental investigations, 2) measurements of COy temperature, and relative humidity (RH), 3) a questionnaire survey of symptom prevalence and perception of environmental conditions using the National Institute for Occupational Safety and Health Indoor Air Quality (NIOSH IAQ) questionnaire, and 4) confidential interview and a review of medical records of employees having respiratory symptoms. COy temperature, and RH measured on the day of questionnaire survey were within the recommended range by American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). Sixty-six percent of respondents were women and 60% considered their job description either "managerial (28%) "or "professional (32%)". Respondents had worked in the building for an average of 5.8 years. Forty-four percent reported having SBS defined as "having one or more symptoms that had occurred at work one or more days a week and tended to get better when away from work". Sex(p=0.001), duration of computer use(p=0.02), use of laser printer (p=0.02), use of cleanser or other office chemicals (p=0.004), feeling too little air movement (p=0.001), feeling air too dry(p=0.001), and unsatisfied with the current job(p=0.02) were related to an increased prevalence of SBS. Use of cleanser or other office chemicals (pO. 01), feeling too little air movement (p=0.01), and feeling air too dry (p=0.02) remained significant predictors of SBS when adjusting other variables by logistic regression analysis. The results of medical record review revealed a discrepancy in the number of diagnosed asthma cases by personal physician and an independent physician. Although this study contains several .limitations (e. g., cross-sectional study, small numbers of study, subjects, etc.), these results indicated that SBS is related to personal, environmental, and psychosocial factors and the precision of diagnosis is critical when evaluating environment-relatedness during disease cluster investigation.

A Study on Air Pollution and Thermal Factors in Underground Shopping Center of Pusan Area / 예방의학회지

For the purpose of preparing the fundamental data on air pollution in underground shopping center and also contributing to the health improvement of resident, the authors measured the level of SO2, NO2, TSP, CO, CO2 and also some related factors as air temperature, air movement, relative humidity and mean radiation temperature at inside and outside of underground shopping center in Pusan from January to February and from July to August 1994. The results were as follows: 1. The mean concentration of CO within the underground shopping center was 3.1+/-1.3ppm in winter and 2.1+/-0.9 ppm in summer. There was a negative correlation (p<0.01) between inner CO concentration and temperature in summer and no correlation between inner CO concentration and outer CO concentration in underground shopping center 2. The mean concentration of C02 within the underground shopping center was 876+/-353 ppm in winter and 757+/-125 ppm in summer. There was a negative correlation (P<0.01) between inner CO2 concentration and air movement in summer and positive correlation (p<0.05) between inner CO2 oncentration and outer CO2 concentration in underground shopping center. 3. The mean concentration SO2 within a underground shopping center was 0.036+/-0.019ppm in winter and 0.040+/-0.013ppm in summer. There was a positive correlation(p<0.01) between inner SO2 concentration and positive correlation between inner SO2 concentration and outer SO2 concentration in summer and winter in Underground shopping center. 4. The mean concentration of NO2 within a underground shopping center was 0.052+/-0.038ppm in winter and 0.042+/-0.016ppm in summer. There was a no correlation between inner NO2 concentration and thermal factors in summer and winter and low correlation between inner NO2 concentration in underground shopping center. 5. The mean concentration of TSP within a underground shopping center was 430+/-214 microgram/m3 in winter, 366+/-73 microgram/m3 in summer, and very in excess of the atmospheric environmental quality standards of Korea(150 microgram/m3). There was low correlation between inner TSP concentration and temperature in summer and high correlation between inner TSP concentration and outer TSP concentration in underground shopping center.

Mathematical models for estimation of gas pollutant dispersion

A mathematical model for computation of gas concentration due to its dispersion has been formulated. The equations deduced are suitable for estimation of gas concentration, within the limits of our study as shown by significance of the overall regression and most of the factors studied. The concentration of NO2 is inversely proportion to the height of the sampling station, and proportional to distance from traffic and population activities and from the sea. The level of pollution was inversely proportioned to wind speed. Day pollution concentrations were higher than night levels

Study of the air pollution problem in a solid waste dumping site and adjacent area in Alexandria

Open dumping is the main method of disposal in Alexandria and is responsible for many nuisances such as evolution of heavy clouds of smoke, fly ash, irritating and noxious gases, malodors, etc. Gases and airborne and settled dust were sampled during winter season and analyzed to their constituents. High concentrations of gases and dust were encountered at stations located in dump site [I-IV] followed by those located downwind of dump site [V and XI]. High particulate concentrations were found in station VII located in industrial area and station VI exposed to traffic activities in the Agricultural highway. Other stations located upwind were not affected. Percent organic, sulfate and chloride content were found to be higher in dust collected from the dump site [I-IV] than the city site [V-XV]. Finally it was concluded that the other sites located around the dump area may be affected by dump site at different prevailing wind directions