A Numerical computation of airflow over Iraq

2020 ◽  
Author(s):  
Firas Sabeeh Basheer1 ◽  
Wedyan Ghalib Nassif ◽  
Hazim H.Hussain Al-Saleem
Keyword(s):  
Surface Roughness ◽  
Wind Speed ◽  
Weather Forecast ◽  
Natural Properties ◽  
Mountainous Regions ◽  
The Earth ◽  
Trend Data ◽  
Bodies Of Water ◽  
The Impact ◽  
Analyze Data

Abstract The best way to understand the general atmosphere system is to collect and analyze data, identify the variables that occur in the upper and lower classes, and compare them with other values in favor of comparing them to other studies and research. Studies have been conducted in this research by analyzing the wind speed and direction and comparing it with the surface roughness to reach a concept by dividing the regions of Iraq on the basis of the surface roughness that affects the wind speed near the surface. The research aims to know the effect of air flow on the nature of the earth's surface and its effect on the different regions in Iraq. The methods used in the study depend on the hourly rates of surface roughness, wind speed and direction taken from the European-Mediterranean Weather Forecast (ECMWF) for a full year 2016 from 34 stations over Iraq. Results obtained from wind speed analysis and trend data. The highest value of wind speed (6.5 m / s) in the less rough areas (0-50 m) is concentrated in the semi-desert in the southern and western regions of the country (Anbar, Najaf and Smawa) and the lowest wind speed (1.8 m / s) for the rough areas (11- 72 m) in the mountainous regions in the northern part of the state. The importance of the results enables us to know the movement of air in this layer in terms of its weakness or strength according to the nature of the surface of the earth, as it has formed (barren lands, bodies of water, mountainous areas), which can be used in future studies to monitor the movement and speed of winds and to determine the natural properties of the air layer in contact with the surface of the earth. This requires knowledge of the impact of temperature, wind speed and direction in dividing the layers of Iraq on the basis of surface roughness.

scholarly journals A Novel Sea Surface Roughness Parameterization Based on Wave State and Sea Foam

2021 ◽  
Vol 9 (3) ◽  
pp. 246
Author(s):  
Difu Sun ◽  
Junqiang Song ◽  
Xiaoyong Li ◽  
Kaijun Ren ◽  
Hongze Leng
Keyword(s):  
Surface Roughness ◽  
Wind Speed ◽  
Drag Coefficient ◽  
Sea Surface ◽  
High Wind Speed ◽  
Wave State ◽  
Wind Speeds ◽  
Sea Surface Roughness ◽  
Extreme Wind ◽  
The Impact

A wave state related sea surface roughness parameterization scheme that takes into account the impact of sea foam is proposed in this study. Using eight observational datasets, the performances of two most widely used wave state related parameterizations are examined under various wave conditions. Based on the different performances of two wave state related parameterizations under different wave state, and by introducing the effect of sea foam, a new sea surface roughness parameterization suitable for low to extreme wind conditions is proposed. The behaviors of drag coefficient predicted by the proposed parameterization match the field and laboratory measurements well. It is shown that the drag coefficient increases with the increasing wind speed under low and moderate wind speed conditions, and then decreases with increasing wind speed, due to the effect of sea foam under high wind speed conditions. The maximum values of the drag coefficient are reached when the 10 m wind speeds are in the range of 30–35 m/s.

scholarly journals An Examination of Wind Decay, Sustained Wind Speed Forecasts, and Gust Factors for Recent Tropical Cyclones in the Mid-Atlantic Region of the United States

2015 ◽  
Vol 30 (1) ◽  
pp. 153-176 ◽  
Author(s):  
Bryce Tyner ◽  
Anantha Aiyyer ◽  
Jonathan Blaes ◽  
Donald Reid Hawkins
Keyword(s):  
Surface Roughness ◽  
Wind Speed ◽  
Tropical Cyclones ◽  
Surface Wind ◽  
Software Tool ◽  
Weather Forecast ◽  
The United States ◽  
Atlantic Region ◽  
Wind Speeds ◽  
Gust Factors

Abstract In this study, several analyses were conducted that were aimed at improving sustained wind speed and gust forecasts for tropical cyclones (TCs) affecting coastal regions. An objective wind speed forecast analysis of recent TCs affecting the mid-Atlantic region was first conducted to set a benchmark for improvement. Forecasts from the National Digital Forecast Database were compared to observations and surface wind analyses in the region. The analysis suggests a general overprediction of sustained wind speeds, especially for areas affected by the strongest winds. Currently, National Weather Service Weather Forecast Offices use a software tool known as the Tropical Cyclone Forecast/Advisory (TCM) wind tool (TCMWindTool) to develop their wind forecast grids. The tool assumes linear decay in the sustained wind speeds when interpolating the National Hurricane Center 12–24-hourly TCM product to hourly grids. An analysis of postlandfall wind decay for recent TCs was conducted to evaluate this assumption. Results indicate that large errors in the forecasted wind speeds can emerge, especially for stronger storms. Finally, an analysis of gust factors for recent TCs affecting the region was conducted. Gust factors associated with weak sustained wind speeds are shown to be highly variable but average around 1.5. The gust factors decrease to values around 1.2 for wind speeds above 40 knots (kt; 1 kt = 0.51 m s−1) and are in general insensitive to the wind direction, suggesting local rather than upstream surface roughness largely dictates the gust factor at a given location. Forecasters are encouraged to increase land reduction factors used in the TCMWindTool and to modify gust factors to account for factors including the sustained wind speed and local surface roughness.

Formation of Lunar Craters and Bright Rays as a Result of Meteorite Impacts

1962 ◽  
Vol 14 ◽  
pp. 415-418
Author(s):  
K. P. Stanyukovich ◽  
V. A. Bronshten
Keyword(s):  
Explosive Charge ◽  
The Moon ◽  
Meteorite Impacts ◽  
The Earth ◽  
Lunar Craters ◽  
The Impact

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.

Mechanisms of liver damage in COVID-19

2020 ◽  
Vol 1 (19) ◽  
pp. 39-46
Author(s):  
T. V. Pinchuk ◽  
N. V. Orlova ◽  
T. G. Suranova ◽  
T. I. Bonkalo
Keyword(s):  
Hepatocellular Carcinoma ◽  
Liver Transplantation ◽  
Risk Factor ◽  
Liver Disease ◽  
Liver Function ◽  
Liver Damage ◽  
The World ◽  
Coronavirus Infection ◽  
The Impact ◽  
Analyze Data

At the end of 2019, a new coronavirus (SARS-CoV-2) was discovered in China, causing the coronavirus infection COVID-19. The ongoing COVID-19 pandemic poses a major challenge to health systems around the world. There is still little information on how infection affects liver function and the significance of pre-existing liver disease as a risk factor for infection and severe COVID-19. In addition, some drugs used to treat the new coronavirus infection are hepatotoxic. In this article, we analyze data on the impact of COVID-19 on liver function, as well as on the course and outcome of COVID-19 in patients with liver disease, including hepatocellular carcinoma, or those on immunosuppressive therapy after liver transplantation.

Prediction of Atmospheric Turbulence Characteristics for Surface Boundary Layer using Empirical Spectral Methods

2020 ◽  
Author(s):  
Yagya Dutta Dwivedi ◽  
Vasishta Bhargava Nukala ◽  
Satya Prasad Maddula ◽  
Kiran Nair
Keyword(s):  
Boundary Layer ◽  
Time Series ◽  
Surface Roughness ◽  
Wind Speed ◽  
Atmospheric Turbulence ◽  
Surface Boundary ◽  
Low Frequencies ◽  
Surface Boundary Layer ◽  
Power Spectral ◽  
Mean Wind Speed

Abstract Atmospheric turbulence is an unsteady phenomenon found in nature and plays significance role in predicting natural events and life prediction of structures. In this work, turbulence in surface boundary layer has been studied through empirical methods. Computer simulation of Von Karman, Kaimal methods were evaluated for different surface roughness and for low (1%), medium (10%) and high (50%) turbulence intensities. Instantaneous values of one minute time series for longitudinal turbulent wind at mean wind speed of 12 m/s using both spectra showed strong correlation in validation trends. Influence of integral length scales on turbulence kinetic energy production at different heights is illustrated. Time series for mean wind speed of 12 m/s with surface roughness value of 0.05 m have shown that variance for longitudinal, lateral and vertical velocity components were different and found to be anisotropic. Wind speed power spectral density from Davenport and Simiu profiles have also been calculated at surface roughness of 0.05 m and compared with k−1 and k−3 slopes for Kolmogorov k−5/3 law in inertial sub-range and k−7 in viscous dissipation range. At high frequencies, logarithmic slope of Kolmogorov −5/3rd law agreed well with Davenport, Harris, Simiu and Solari spectra than at low frequencies.

Water as a Blessing and a Transient Resource: A Call to Re-Define Modern Attitudes towards Water in Light of Job 14:7–12

2018 ◽  
Vol 26 (2) ◽  
Author(s):  
Jonathan Kivatsi Kavusa
Keyword(s):  
Human Life ◽  
Renewable Resource ◽  
Dead Tree ◽  
Responsible Management ◽  
The Earth ◽  
Metaphor Theory ◽  
Bodies Of Water ◽  
Ecological Potential

This article explores the ecological potential in Job 14:7–12. The metaphor in Job 14 praises the life-giving potential of water to revive a dead tree before presenting its transient character, similar to human life. The article investigates the question of why the author of Job finds it appropriate to use water and water-related images to contrast the potential of water to revive a dead tree with the transient mortals who disappear at death like great bodies of water in times of drought. Using elements of historical, critical, and literary approaches, as well as metaphor theory, and applying the Earth Bible Principle of intrinsic worth, this article argues that water should not be viewed as a limitlessly renewable resource, but a precious gift requiring responsible management.

scholarly journals Smoothing additive manufactured parts using ns-pulsed laser radiation

2021 ◽  
Author(s):  
Florian Kuisat ◽  
Fernando Lasagni ◽  
Andrés Fabián Lasagni
Keyword(s):  
Surface Roughness ◽  
Mechanical Performance ◽  
State Of The Art ◽  
Pulsed Laser ◽  
Industrial Applications ◽  
Laser Source ◽  
Pulsed Laser Radiation ◽  
Current State ◽  
The Impact

AbstractIt is well known that the surface topography of a part can affect its mechanical performance, which is typical in additive manufacturing. In this context, we report about the surface modification of additive manufactured components made of Titanium 64 (Ti64) and Scalmalloy®, using a pulsed laser, with the aim of reducing their surface roughness. In our experiments, a nanosecond-pulsed infrared laser source with variable pulse durations between 8 and 200 ns was applied. The impact of varying a large number of parameters on the surface quality of the smoothed areas was investigated. The results demonstrated a reduction of surface roughness Sa by more than 80% for Titanium 64 and by 65% for Scalmalloy® samples. This allows to extend the applicability of additive manufactured components beyond the current state of the art and break new ground for the application in various industrial applications such as in aerospace.

Effectiveness of Auctions in Securing Price Support for Farmers: The Case of a Grain Market in India

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Neha Gupta
Keyword(s):  
Lower Cost ◽  
Secondary Data ◽  
Price Support ◽  
Minimum Support ◽  
Minimum Price ◽  
Support Price ◽  
The Government ◽  
Nonparametric Estimates ◽  
The Impact ◽  
Analyze Data

Abstract This paper reviews rice procurement operations of Government of India from the standpoints of cost of procurement as well as effectiveness in supporting farmers’ incomes. The two channels in use for procuring rice till 2015, were custom milling of rice and levy. In the first, the government bought paddy directly from farmers at the minimum support price (MSP) and got it milled from private millers; while in the second, it purchased rice from private millers at a pre-announced levy price thus providing indirect price support to farmers. Secondary data reveal that levy, despite implying lower cost of procurement was discriminated against till about a decade back and eventually abolished in 2015 in favor of custom milling, better trusted to provide minimum price support. We analyze data from auctions of paddy from a year when levy was still important to investigate its impact on farmers’ revenues. We use semi-nonparametric estimates of millers’ values to simulate farmers’ expected revenues and find these to be rather close to the MSP; a closer analysis shows that bidder competition is critical to this result. Finally, we use our estimates to quantify the impact of change in levy price on farmers’ revenues and use this to discuss ways to revive the levy channel.

scholarly journals The ground-level ozone concentration is inversely correlated with the number of COVID-19 cases in Warsaw, Poland

2021 ◽  
Author(s):  
Oskar Wiśniewski ◽  
Wiesław Kozak ◽  
Maciej Wiśniewski
Keyword(s):  
Wind Speed ◽  
Ozone Concentration ◽  
Inverse Correlation ◽  
Ground Level ◽  
Viral Agent ◽  
The Novel ◽  
Weather Factors ◽  
Ground Level Ozone ◽  
The Many ◽  
The Impact

AbstractCOVID-19, which is a consequence of infection with the novel viral agent SARS-CoV-2, first identified in China (Hubei Province), has been declared a pandemic by the WHO. As of September 10, 2020, over 70,000 cases and over 2000 deaths have been recorded in Poland. Of the many factors contributing to the level of transmission of the virus, the weather appears to be significant. In this work, we analyze the impact of weather factors such as temperature, relative humidity, wind speed, and ground-level ozone concentration on the number of COVID-19 cases in Warsaw, Poland. The obtained results show an inverse correlation between ground-level ozone concentration and the daily number of COVID-19 cases.

scholarly journals Measurement of the Sea Surface Height with Airborne GNSS Reflectometry and Delay Bias Calibration

2021 ◽  
Vol 13 (15) ◽  
pp. 3014
Author(s):  
Feng Wang ◽  
Dongkai Yang ◽  
Guodong Zhang ◽  
Jin Xing ◽  
Bo Zhang ◽  
...  
Keyword(s):  
Wind Speed ◽  
Arrival Time ◽  
Elevation Angle ◽  
Satellite System ◽  
Sea Surface Height ◽  
Antenna Pattern ◽  
Sea Surface ◽  
Observation Method ◽  
Global Navigation Satellite ◽  
The Impact

Sea surface height can be measured with the delay between reflected and direct global navigation satellite system (GNSS) signals. The arrival time of a feature point, such as the waveform peak, the peak of the derivative waveform, and the fraction of the peak waveform is not the true arrival time of the specular signal; there is a bias between them. This paper aims to analyze and calibrate the bias to improve the accuracy of sea surface height measured by using the reflected signals of GPS CA, Galileo E1b and BeiDou B1I. First, the influencing factors of the delay bias, including the elevation angle, receiver height, wind speed, pseudorandom noise (PRN) code of GPS CA, Galileo E1b and BeiDou B1I, and the down-looking antenna pattern are explored based on the Z-V model. The results show that (1) with increasing elevation angle, receiver height, and wind speed, the delay bias tends to decrease; (2) the impact of the PRN code is uncoupled from the elevation angle, receiver height, and wind speed, so the delay biases of Galileo E1b and BeiDou B1I can be derived from that of GPS CA by multiplication by the constants 0.32 and 0.54, respectively; and (3) the influence of the down-looking antenna pattern on the delay bias is lower than 1 m, which is less than that of other factors; hence, the effect of the down-looking antenna pattern is ignored in this paper. Second, an analytical model and a neural network are proposed based on the assumption that the influence of all factors on the delay bias are uncoupled and coupled, respectively, to calibrate the delay bias. The results of the simulation and experiment show that compared to the meter-level bias before the calibration, the calibrated bias decreases the decimeter level. Based on the fact that the specular points of several satellites are visible to the down-looking antenna, the multi-observation method is proposed to calibrate the bias for the case of unknown wind speed, and the same calibration results can be obtained when the proper combination of satellites is selected.

Sign in / Sign up

Export Citation Format

Share Document