The prediction of the mean hourly average maximum ground level concentration of sulphur dioxide at Tilbury

1974 ◽  
Vol 8 (6) ◽  
pp. 543-554 ◽  
Author(s):  
D.J. Moore
Keyword(s):  
Sulphur Dioxide ◽  
Ground Level ◽  
Ground Level Concentration ◽  
Average Maximum ◽  
The Mean

scholarly journals Large-Eddy Simulations of a Drizzling, Stratocumulus-Topped Marine Boundary Layer

2009 ◽  
Vol 137 (3) ◽  
pp. 1083-1110 ◽  
Author(s):  
Andrew S. Ackerman ◽  
Margreet C. vanZanten ◽  
Bjorn Stevens ◽  
Verica Savic-Jovcic ◽  
Christopher S. Bretherton ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Marine Boundary Layer ◽  
Cloud Water ◽  
Large Eddy Simulations ◽  
Cloud Base ◽  
Entrainment Rate ◽  
Liquid Water Path ◽  
Average Maximum ◽  
Large Eddy ◽  
The Mean

Abstract Cloud water sedimentation and drizzle in a stratocumulus-topped boundary layer are the focus of an intercomparison of large-eddy simulations. The context is an idealized case study of nocturnal stratocumulus under a dry inversion, with embedded pockets of heavily drizzling open cellular convection. Results from 11 groups are used. Two models resolve the size distributions of cloud particles, and the others parameterize cloud water sedimentation and drizzle. For the ensemble of simulations with drizzle and cloud water sedimentation, the mean liquid water path (LWP) is remarkably steady and consistent with the measurements, the mean entrainment rate is at the low end of the measured range, and the ensemble-average maximum vertical wind variance is roughly half that measured. On average, precipitation at the surface and at cloud base is smaller, and the rate of precipitation evaporation greater, than measured. Including drizzle in the simulations reduces convective intensity, increases boundary layer stratification, and decreases LWP for nearly all models. Including cloud water sedimentation substantially decreases entrainment, decreases convective intensity, and increases LWP for most models. In nearly all cases, LWP responds more strongly to cloud water sedimentation than to drizzle. The omission of cloud water sedimentation in simulations is strongly discouraged, regardless of whether or not precipitation is present below cloud base.

scholarly journals An Analytical Simple Formula for the Ground Level Concentration from a Point Source

Atmosphere ◽  
2011 ◽  
Vol 2 (2) ◽  
pp. 21-35 ◽  
Author(s):  
Tiziano Tirabassi ◽  
Alessandro Tiesi ◽  
Marco T. Vilhena ◽  
Bardo E.J. Bodmann ◽  
Daniela Buske
Keyword(s):  
Point Source ◽  
Simple Formula ◽  
Ground Level ◽  
Ground Level Concentration

scholarly journals Do experienced physiotherapists apply equal magnitude of force during a grade I central pa on the cervical spine?

2004 ◽  
Vol 60 (4) ◽  
Author(s):  
M. Conradie ◽  
E. Smit ◽  
M. Louw ◽  
M. Prinsloo ◽  
L. Loubser ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Spinal Disorders ◽  
Joint Mobilization ◽  
Treatment Techniques ◽  
Average Maximum ◽  
Manual Examination ◽  
The Mean ◽  
The Difference ◽  
Posterior Anterior ◽  
Selection Of

Background and purpose: Physiotherapists frequently use central posterior-anterior (PA) joint mobilization techniques for assessing and managing spinal disorders. Manual examination findings provide the basis for the selection of treatment techniques. From the literature it is evident that the level of reliability varies when physiotherapists perform different mobilization techniques. Repeatability of mobilization techniques is important for better physiotherapy management. The aim of the study was to determine whether experienced physiotherapists apply equal magnitude of force during a grade I central PA mobilisation technique on the cervical spine. Another aim was to determine the variation in the magnitude of forceapplied by each individual physiotherapist. Subjects: Sample of convenience, consisting of sixteen (n=16) selected qualified physiotherapists with experience inOrthopaedic Manual Therapy.Methods: A grade I central PA was performed on the Flexiforce TM sensors positioned on C6 of the same asymptomatic model to measure the applied magnitude of force. Two separate measurements, each lasting 30-seconds, were obtained.Results: The average maximum peak force applied by the majority of physiotherapists (87.5%) was between 10.95gand 72g. The difference in the forces applied for the two measurements ranged between 0.64g and 24.4g. The BlandAltman scatterplot determined the mean of the difference between measurement one and two, calculated for the group, was zero. When comparing the two measurements, little variation was noted in the forces applied, as well as the coefficient of variation for each physiotherapist.Conclusion and Discussion: Current results demonstrated good intra-therapist and moderate to good inter-therapist repeatability. Further research is required to generalize results.

scholarly journals High Terrestrial Radiation Level in an Active Tin-Mine at Jos South, Nigeria

2020 ◽  
Vol 24 (3) ◽  
pp. 435-442 ◽  
Author(s):  
M. Atipo ◽  
O. Olarinoye ◽  
B. Awojoyogbe ◽  
M. Kolo
Keyword(s):  
Gamma Radiation ◽  
Dose Rate ◽  
Technological Development ◽  
Absorbed Dose ◽  
Ground Level ◽  
Absorbed Dose Rate ◽  
Lifetime Cancer Risk ◽  
Radiation Level ◽  
Background Gamma Radiation ◽  
The Mean

Mineral mining and milling can be a source of national economic and technological development. However, mining of minerals has been confirmed to disturb the natural distribution of radioisotopes in the soil, air and water bodies in the biota. In an attempt to evaluate the radiological burden resulting from tin mining activities at Rayfield-Du area of Jos, the background gamma-radiation level in the mine was measured via a well calibratedhand-held dosimeter placed at 1 m above ground level. The mean absorbed dose rate, annual effective dose rate and excess lifetime cancer risk for the mine was 0.83 μSvh-1; 1.44 mSv-1 and 0.005 respectively. Generally, dose rates were higher in the mine pits and processing areas as compared to administrative areas of the mine. The mean measured dose rate and calculated dose parameters for the mine were all high when compared to the regulatory limit for public exposure. The potential of developing radiation-induced health defects as a result of high radiation absorbed dose rate by the miners and dwellers around the mine is highly probable.  Keywords: Gamma-radiation; mine; absorbed dose rate; radiation exposure.

scholarly journals Status of Air Pollution Regulations Affecting Gas Turbines in 80 Nations

1974 ◽  
Author(s):  
R. J. Ketterer ◽  
N. R. Dibelius
Keyword(s):  
Air Pollution ◽  
Carbon Monoxide ◽  
Sulfur Dioxide ◽  
Gas Turbines ◽  
Ground Level ◽  
Oxides Of Nitrogen ◽  
Ground Level Concentration ◽  
Pollution Emissions ◽  
Air Pollution Emissions

This paper summarizes regulations from 80 countries covering air pollution emissions from gas turbines. The paper includes emission and ground level concentration standards for particulates, sulfur dioxide, oxides of nitrogen, visible emissions, and carbon monoxide.

scholarly journals Observation of sensible and latent heat flux profiles with lidar

2020 ◽  
Vol 13 (6) ◽  
pp. 3221-3233 ◽  
Author(s):  
Andreas Behrendt ◽  
Volker Wulfmeyer ◽  
Christoph Senff ◽  
Shravan Kumar Muppa ◽  
Florian Späth ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Heat Flux ◽  
Latent Heat ◽  
Latent Heat Flux ◽  
Sensible Heat Flux ◽  
Ground Level ◽  
Sensible Heat ◽  
Flux Divergence ◽  
Convective Boundary ◽  
The Mean

Abstract. We present the first measurement of the sensible heat flux (H) profile in the convective boundary layer (CBL) derived from the covariance of collocated vertical-pointing temperature rotational Raman lidar and Doppler wind lidar measurements. The uncertainties of the H measurements due to instrumental noise and limited sampling are also derived and discussed. Simultaneous measurements of the latent heat flux profile (L) and other turbulent variables were obtained with the combination of water-vapor differential absorption lidar (WVDIAL) and Doppler lidar. The case study uses a measurement example from the HOPE (HD(CP)2 Observational Prototype Experiment) campaign, which took place in western Germany in 2013 and presents a cloud-free well-developed quasi-stationary CBL. The mean boundary layer height zi was at 1230 m above ground level. The results show – as expected – positive values of H in the middle of the CBL. A maximum of (182±32) W m−2, with the second number for the noise uncertainty, is found at 0.5 zi. At about 0.7 zi, H changes sign to negative values above. The entrainment flux was (-62±27) W m−2. The mean sensible heat flux divergence in the observed part of the CBL above 0.3 zi was −0.28 W m−3, which corresponds to a warming of 0.83 K h−1. The L profile shows a slight positive mean flux divergence of 0.12 W m−3 and an entrainment flux of (214±36) W m−2. The combination of H and L profiles in combination with variance and other turbulent parameters is very valuable for the evaluation of large-eddy simulation (LES) results and the further improvement and validation of turbulence parameterization schemes.

scholarly journals Boundary layer evolution over the central Himalayas from radio wind profiler and model simulations

2016 ◽  
Vol 16 (16) ◽  
pp. 10559-10572 ◽  
Author(s):  
Narendra Singh ◽  
Raman Solanki ◽  
Narendra Ojha ◽  
Ruud H. H. Janssen ◽  
Andrea Pozzer ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Mixed Layer ◽  
Surface Ozone ◽  
Wrf Model ◽  
Ground Level ◽  
Wind Profiler ◽  
Pollution Transport ◽  
Local Boundary ◽  
The Mean

Abstract. We investigate the time evolution of the Local Boundary Layer (LBL) for the first time over a mountain ridge at Nainital (79.5° E, 29.4° N, 1958 m a.m.s.l.) in the central Himalayan region, using a radar wind profiler (RWP) during November 2011 to March 2012, as a part of the Ganges Valley Aerosol Experiment (GVAX). We restrict our analysis to clear–sunny days, resulting in a total of 78 days of observations. The standard criterion of the peak in the signal-to-noise ratio (S ∕ N) profile was found to be inadequate in the characterization of mixed layer (ML) top at this site. Therefore, we implemented a criterion of S ∕ N > 6 dB for the characterization of the ML and the resulting estimations are shown to be in agreement with radiosonde measurements over this site. The daytime average (05:00–10:00 UTC) observed boundary layer height ranges from 440 ± 197 m in November (late autumn) to 766 ± 317 m above ground level (a.g.l.) in March (early spring). The observations revealed a pronounced impact of mountain topography on the LBL dynamics during March, when strong winds (> 5.6 m s−1) lead to LBL heights of 650 m during nighttime. The measurements are further utilized to evaluate simulations from the Weather Research and Forecasting (WRF) model. WRF simulations captured the day-to-day variations up to an extent (r2 = 0.5), as well as the mean diurnal variations (within 1σ variability). The mean biases in the daytime average LBL height vary from −7 % (January) to +30 % (February) between model and observations, except during March (+76 %). Sensitivity simulations using a mixed layer model (MXL/MESSy) indicated that the springtime overestimation of LBL would lead to a minor uncertainty in simulated surface ozone concentrations. However, it would lead to a significant overestimation of the dilution of black carbon aerosols at this site. Our work fills a gap in observations of local boundary layer over this complex terrain in the Himalayas, and highlights the need for year-long simultaneous measurements of boundary layer dynamics and air quality to better understand the role of lower tropospheric dynamics in pollution transport.

The safety of dental extractions in patients with hematologic malignancies.

1989 ◽  
Vol 7 (6) ◽  
pp. 798-802 ◽  
Author(s):  
S K Williford ◽  
P L Salisbury ◽  
J E Peacock ◽  
J M Cruz ◽  
B L Powell ◽  
...  
Keyword(s):  
Wound Healing ◽  
Myeloproliferative Disorders ◽  
Hematologic Malignancies ◽  
Maximum Temperature ◽  
Average Maximum ◽  
Average Maximum Temperature ◽  
Sources Of Infection ◽  
The Mean ◽  
Risk For Bleeding ◽  
Dental Infections

Dental disorders have been recognized as major sources of infection in patients with hematologic malignancies (HM). Management of severe dental infections usually includes dental extractions (DE), but the safety of extractions in patients with HM who are at risk for bleeding, sepsis, and poor wound healing has not been well established. In conjunction with an aggressive program of dental care, 142 DE were performed in 26 patients with acute leukemia, myelodysplastic syndromes, and myeloproliferative disorders. Granulocytopenia (less than 1,000 granulocytes/microL) was present during or within ten days following surgery in 14 patients. In these 14 patients (101 DE), the mean granulocyte count was less than 450/microL, with a median duration of granulocytopenia following surgery of 32 days (range, four to 169 days). Thrombocytopenia (less than 100,000 platelets/microL) occurred during or within two days following surgery in 13 patients (80 DE), with a mean platelet count of 63,500/microL. Transfusions were given for platelet counts less than 50,000/microL. All DE were performed without significant complications. Bleeding was minor to moderate and easily controlled with local measures; no patient required transfusion due to hemorrhage. Average maximum temperature 24 hours after DE was 37.7 degrees C. No episodes of bacteremia were documented within ten days of DE. Minor delay in wound healing was observed in two patients. We conclude that DE can be safely performed in patients with HM in combination with aggressive supportive care.

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