scholarly journals Wind Characteristics in Mountainous Valleys Obtained through Field Measurement

2021 ◽  
Vol 11 (16) ◽  
pp. 7717
Author(s):  
Feng Wang ◽  
Xinming Chen ◽  
Rui He ◽  
Yan Liu ◽  
Jianming Hao ◽  
...  
Keyword(s):  
Wind Field ◽  
Measurement Data ◽  
Western China ◽  
Observation Instruments ◽  
Wind Characteristics ◽  
The Mean ◽  
Set Up ◽  
One Year ◽  
Fluctuating Wind ◽  
Observation Period

The wind characteristics of the mountainous environment in Western China are extremely complex. Many advances have occurred in the study of wind characteristics in plains or hilly areas. However, some limitations remain in the study of mountain passes and riverbanks. We selected a mountain pass and river beach in a certain area as the research objects, then set up observation instruments at different locations to establish temporary observation stations to collect more than one year of measured data. By processing the measurement data during the observation period, the mean wind characteristics and fluctuating wind characteristics of the area were obtained. Through comparison with the standard, we found strong nonstationary characteristics of the wind, such as large deviations between the wind field characteristics values in the standard and measured values, proving the need for wind field observations of mountain passes and riverbanks.

scholarly journals Retrieval of stratospheric and tropospheric BrO columns from multi-axis DOAS measurements at Reunion Island (21° S, 56° E)

2007 ◽  
Vol 7 (3) ◽  
pp. 8261-8308 ◽  
Author(s):  
N. Theys ◽  
M. Van Roozendael ◽  
F. Hendrick ◽  
C. Fayt ◽  
C. Hermans ◽  
...  
Keyword(s):  
Measurement Data ◽  
Retrieval Algorithm ◽  
Reunion Island ◽  
Spectral Measurements ◽  
Réunion Island ◽  
One Year ◽  
Chemical Fields ◽  
Latitudinal Band ◽  
Observation Period ◽  
Good Agreement

Abstract. Spectral measurements of BrO using zenith-sky and off-axis viewing geometries are combined in a linear multiple regression retrieval algorithm to provide stratospheric and tropospheric BrO vertical columns. One year of measurement data are investigated over Reunion-Island (20.9° S, 55.5° E), from July 2004 to July 2005. No seasonal variations of the retrieved BrO columns could be observed, in line with previous studies. A comparison between the stratospheric columns retrieved at 45°, 80°, 85°, 87.5° and 92.5° solar zenith angles and photochemical simulations initialized by chemical fields from the 3-D-CTM SLIMCAT and further constrained by observed NO2 profiles shows a good agreement only by considering a contribution from the very short-lived organic bromine substances to the stratospheric inorganic bromine budget, of 6 to 8 pptv. Furthermore, stratospheric BrO profiles retrieved from late twilight zenith-sky observations are consistent with a total inorganic bromine (Bry) loading of approximately 23 pptv. This represents 6 to 7 pptv more than can be supplied by long-lived organic bromine sources, and therefore supports an added contribution from very short-lived organic bromine substances as recently suggested in several other studies. Moreover strong evidences are presented for the existence of a substantial amount of BrO in the tropical free-troposphere, around 6 km altitude, possibly supplied by the decomposition of short-lived biogenic bromine organic compounds. Tropospheric BrO vertical columns of 1.1±0.45×1013 molec/cm2 are derived for the entire observation period. Comparisons between ground-based BrO vertical columns and total BrO columns derived from SCIAMACHY (onboard the ENVISAT satellite) nadir observations in a latitudinal band centered around 21° S present a good level of consistency, which further strengthens the conclusions of our study.

scholarly journals Wind speed modeling based on measurement data to predict future wind speed with modified Rayleigh model

2021 ◽  
Vol 12 (3) ◽  
pp. 1823
Author(s):  
Suwarno Suwarno ◽  
Rohana Rohana
Keyword(s):  
Wind Speed ◽  
Measurement Data ◽  
Rayleigh Distribution ◽  
Scale Factor ◽  
Percentage Error ◽  
Monthly Data ◽  
Wind Speeds ◽  
Wind Characteristics ◽  
One Year ◽  
The Many

The development of modeling wind speed plays a very important in helping to obtain the actual wind speed data for the benefit of the power plant planning in the future. The wind speed in this paper is obtained from a PCE-FWS 20 type measuring instrument with a duration of 30 minutes which is accumulated into monthly data for one year (2019). Despite the many wind speed modeling that has been done by researchers. Modeling wind speeds proposed in this study were obtained from the modified Rayleigh distribution. In this study, the Rayleigh scale factor (<em>C<sub>r</sub></em>) and modified Rayleigh scale factor (<em>C<sub>m</sub></em>) were calculated. The observed wind speed is compared with the predicted wind characteristics. The data fit test used correlation coefficient (R<sup>2</sup>), root means square error (RMSE), and mean absolute percentage error (MAPE). The results of the proposed modified Rayleigh model provide very good results for users.

scholarly journals Retrieval of stratospheric and tropospheric BrO columns from multi-axis DOAS measurements at Reunion Island (21° S, 56° E)

2007 ◽  
Vol 7 (18) ◽  
pp. 4733-4749 ◽  
Author(s):  
N. Theys ◽  
M. Van Roozendael ◽  
F. Hendrick ◽  
C. Fayt ◽  
C. Hermans ◽  
...  
Keyword(s):  
Measurement Data ◽  
Retrieval Algorithm ◽  
Reunion Island ◽  
Spectral Measurements ◽  
Réunion Island ◽  
One Year ◽  
Chemical Fields ◽  
Latitudinal Band ◽  
Observation Period ◽  
Good Agreement

Abstract. Spectral measurements of BrO using zenith-sky and off-axis viewing geometries are combined in a linear multiple regression retrieval algorithm to provide stratospheric and tropospheric BrO vertical columns. One year of measurement data are investigated over Reunion-Island (20.9° S, 55.5° E), from August 2004 to June 2005. A comparison between the stratospheric columns retrieved at 45°, 80°, 85°, 87.5° and 92.5° solar zenith angles and photochemical simulations initialized by chemical fields from the 3-D-CTM SLIMCAT and further constrained by observed NO2 profiles shows a good agreement only by considering a contribution from the very short-lived organic bromine substances to the stratospheric inorganic bromine budget, of 6 to 8 pptv. Furthermore, stratospheric BrO profiles retrieved from late twilight zenith-sky observations are consistent with a total inorganic bromine (Bry) loading of approximately 23 pptv. This represents 6 to 7 pptv more than can be supplied by long-lived organic bromine sources, and therefore supports an added contribution from very short-lived organic bromine substances as recently suggested in several other studies. Moreover strong evidences are presented for the existence of a substantial amount of BrO in the tropical free-troposphere, around 6 km altitude, possibly supplied by the decomposition of short-lived biogenic bromine organic compounds. Tropospheric BrO vertical columns of 1.1±0.45×1013 molec/cm² are derived for the entire observation period. Comparisons between ground-based BrO vertical columns and total BrO columns derived from SCIAMACHY (onboard the ENVISAT satellite) nadir observations in a latitudinal band centered around 21° S present a good level of consistency, which further strengthens the conclusions of our study.

Wind tunnel tests on the characteristics of wind fields over a simplified gorge

2016 ◽  
Vol 20 (10) ◽  
pp. 1599-1611 ◽  
Author(s):  
Peng Hu ◽  
Yongle Li ◽  
Yan Han ◽  
CS Cai ◽  
Guoji Xu
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Wind Direction ◽  
Wind Field ◽  
Small Range ◽  
Wind Fields ◽  
Wind Speeds ◽  
Mean Wind Speed ◽  
Wind Characteristics ◽  
The Mean

Characteristics of wind fields over the gorge or valley terrains are becoming more and more important to the structural wind engineering. However, the studies on this topic are very limited. To obtain the fundamental characteristics information about the wind fields over a typical gorge terrain, a V-shaped simplified gorge, which was abstracted from some real deep-cutting gorges where long-span bridges usually straddle, was introduced in the present wind tunnel studies. Then, the wind characteristics including the mean wind speed, turbulence intensity, integral length scale, and the wind power spectrum over the simplified gorge were studied in a simulated atmospheric boundary layer. Furthermore, the effects of the oncoming wind field type and oncoming wind direction on these wind characteristics were also investigated. The results show that compared with the oncoming wind, the wind speeds at the gorge center become larger, but the turbulence intensities and the longitudinal integral length scales become smaller. Generally, the wind fields over the gorge terrain can be approximately divided into two layers, that is, the gorge inner layer and the gorge outer layer. The different oncoming wind field types have remarkable effects on the mean wind speed ratios near the ground. When the angle between the oncoming wind and the axis of the gorge is in a certain small range, such as smaller than 10°, the wind fields are very close to those associated with the wind direction of 0°. However, when the angle is in a larger range, such as larger than 20°, the wind fields in the gorge will significantly change. The research conclusions can provide some references for civil engineering practices regarding the characteristics of wind fields over the real gorge terrains.

scholarly journals Large Eddy simulation of the fluctuating wind environment at a bridge site in the mountainous area

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Longfei Xing ◽  
Mingjin Zhang ◽  
Yongle Li ◽  
Zhijie Zhang ◽  
Dianguo Yin
Keyword(s):  
Time History ◽  
Mountainous Area ◽  
Wind Flow ◽  
Bridge Site ◽  
Wind Environment ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Wind Characteristics ◽  
The Mean ◽  
Fluctuating Wind

AbstractTo have a comprehensive understanding of the complex wind environment at a bridge site in the mountainous area, a numerical simulation study of the wind environment under the mean and the fluctuating wind flow conditions was carried out and the results were compared. First, according to the weighted amplitude wave superposition (WAWS) method, the fluctuating wind speed time history was compiled by UDF. And the wind speed time history was added to the inlet boundary of a numerical empty wind tunnel to verify the feasibility of the simulation method of the fluctuating wind. Then, with a bridge in the mountainous area in Yunnan as the engineering background, a numerical simulation study of the wind environment of the bridge site area under the mean wind flow and the fluctuating wind flow was carried out by using FLUENT. The study indicates that Large Eddy Simulation (LES) method more accurate than Reynold average method with a sufficient number of grids and a short enough time step. The average wind characteristics of the bridge site under the mean wind and the fluctuating wind are not much different. The fluctuating wind characteristics at the bridge site are mainly affected by the terrain and the pulsating component of the wind flow. There are different terrain pulsation effects at the bridge site under different incoming flow directions.

COMPARATIVE EVALUATION OF THE CAUSES OF DEATH IN A COHORT OF WORKERS IN THE MINING AND ENRICHMENT OF CHRYSOTILE ASBESTOS

2021 ◽  
Author(s):  
E.V. Kovalevskiy ◽  
◽  
J. Schüz ◽  
S.V. Kashanskiy ◽  
◽  
...  
Keyword(s):  
Comparative Evaluation ◽  
Causes Of Death ◽  
Malignant Neoplasms ◽  
Chrysotile Asbestos ◽  
Asbestos Fibers ◽  
Occupationally Exposed ◽  
The Mean ◽  
One Year ◽  
Observation Period

Abstract. A retrospective cohort study was carried out to investigate the mortality of workers occupationally exposed to dust containing chrysotile asbestos fibers. In its chemical and physical properties, it differs from the fibers of other types of asbestos and is the only type of asbestos that is currently approved for use in many countries of the world. The members of the cohort are current and former employees who have worked for at least one year at the production sites of the complex of enterprises for the mining and enrichment of chrysotile asbestos (JSC «Uralasbest», Asbest, Sverdlovsk region) in the period from 01.01.1975 to 31.12.2010. Of the 35837 members of the cohort, 12729 (35.5%) people died (2373 of them were malignant neoplasms of various localizations, including 10 mesotheliomas), 18799 (52.5%) were alive at the end of the observation period (2015), and 4309 people (12.0%) were censored by the end of 2015. The mean follow-up period was 21.7 years for men and 25.9 years for women. The average age at death was 59.4 years for men and 66.5 years for women. This paper presents a general comparative evaluation of the causes of death of cohort members. Further processing of data obtained is currently underway.

Experience of cohort formation and data collection in a retrospective cohort epidemiological study

2021 ◽  
Vol 61 (4) ◽  
pp. 253-266
Author(s):  
Evgeny V. Kovalevskiy ◽  
Joachim Schüz ◽  
Igor V. Bukhtiyarov ◽  
Sergey V. Kashanskiy
Keyword(s):  
Retrospective Cohort ◽  
Malignant Neoplasms ◽  
Chrysotile Asbestos ◽  
Asbestos Fibers ◽  
The World ◽  
Occupationally Exposed ◽  
The Mean ◽  
One Year ◽  
Observation Period

A retrospective cohort study was carried out to investigate the mortality of workers occupationally exposed to dust containing chrysotile asbestos fibers. In its chemical and physical properties, it differs from the fibers of other types of asbestos and is the only type of asbestos that is currently approved for use in many countries of the world. The members of the cohort are current and former employees who have worked for at least one year at the production sites of the complex of enterprises for the mining and enrichment of chrysotile asbestos (JSC "Uralasbest", Asbest, Sverdlovsk region) in the period from 01.01.1975 to 31.12.2010. Of the 35,837 members of the cohort, 12,729 (35.5%) people died (2,373 of them were malignant neoplasms of various localizations, including 10 mesotheliomas), 18,799 (52.5%) were alive at the end of the observation period (2015), and 4,309 people (12.0%) were censored by the end of 2015. The mean follow-up period was 21.7 years for men and 25.9 years for women. The average age at death was 59.4 years for men and 66.5 years for women. It is currently the world's largest cohort of workers in the field.

HRA Model for Hypercholesterolemia Based on a Longitudinal Health Database

1998 ◽  
Vol 37 (02) ◽  
pp. 130-133
Author(s):  
T. Kishimoto ◽  
Y. Iida ◽  
K. Yoshida ◽  
M. Miyakawa ◽  
H. Sugimori ◽  
...  
Keyword(s):  
Total Cholesterol ◽  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Model Analysis ◽  
Serum Total Cholesterol ◽  
Hazards Model ◽  
The Mean ◽  
Health Database ◽  
Observation Period

AbstractTo evaluate the risk factors for hypercholesterolemia, we examined 4,371 subjects (3,207 males and 1,164 females) who received medical checkups more than twice at an AMHTS in Tokyo during the period from 1976 through 1991; and whose serum total cholesterol was under 250 mg/dl. The mean follow-up duration was 6.6 years. A self-registering questionnaire was administered at the time of the health checkup. The endpoint of this study was the onset of hypercholesterolemia when the level of serum total cholesterol was 250 mg/dl and over. We compared two prognosis groups (normal and hypercholesterol) in terms of age, examination findings and lifestyle. After assessing each variable, we employed Cox's proportional hazards model analysis to determine the factors related to the occurrence of hypercholesterolemia. According to proportional hazards model analysis, total cholesterol, triglyceride and smoking at the beginning, and hypertension during the observation period were selected in males; and total cholesterol at the beginning and age were selected in females to determine the factors related to the occurrence of hypercholesterolemia.

Pharmacokinetics and Tolerability of Factor XIII Concentrates Prepared from Human Placenta or Plasma: a Crossover Randomised Study

1995 ◽  
Vol 74 (02) ◽  
pp. 622-625 ◽  
Author(s):  
H H Brackmann ◽  
R Egbring ◽  
A Ferster ◽  
P Fondu ◽  
J M Girardel ◽  
...  
Keyword(s):  
Factor Xiii ◽  
Bleeding Events ◽  
Serious Adverse Events ◽  
Double Blind ◽  
Randomised Study ◽  
The Mean ◽  
Blind Crossover Study ◽  
Double Blind Crossover Study ◽  
Fxiii Activity ◽  
Observation Period

SummaryThe pharmacokinetics and tolerability of factor XIII (FXIII) from plasma were compared with those of FXIII from placenta in a randomised, double-blind, crossover study involving 13 patients with congenital FXIII deficiency. Both FXIII activity and FXIII antigen were monitored. No difference was seen in the mean half-lives of the two preparations (9.3 days and 9.1 days for plasma and placenta FXIII activity, respectively). Response was similar for both preparations, but was slightly greater for FXIII from plasma.Similar results were found for recovery (65% vs 60%). The area under the data completed by extrapolation was significantly higher for FXIII from plasma. No differences between preparations in terms of efficacy or tolerability were observed. It can be concluded that treatment with FXIII concentrate from plasma is as efficient as with FXIII concentrate from placenta in terms of recovery and half-life. Both preparations were equivalent in terms of safety during the observation period. With the administration of monthly injections of approximately 30 U/kg serious bleeding events were prevented and no other serious adverse events occurred.

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