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The study of landfill sites is one of the most important subjects in engineering geology. The landfill site selection involves various elements such as engineering, science, and politics. In this case study, landfill site selection was performed by developing a multi-criteria decision analysis (MCDA) method in the Gharehchai basin, Hamedan province, west of Iran. Fuzzy membership functions (FMFs) resultant from GIS analysis are base of this method. Twelve different criteria including surface water, water table, geologic unit permeability, soil type, slope, distance to faults and sinkholes, main roads, residential areas, distance from water well and Qanat, Normalized Difference Vegetation Index (NDVI), wind speed and direction and distance from special land use were used to landfill site selection. The fuzzy-based MCDA technique can help the decision-makers to understand the complete estimation process and make a better decision to select a proper site for landfills. FMFs were used to standardize the criteria to be applied in the development of a landfill site suitability map. Lastly, a suitability map was prepared by fuzzy overlay analyses (Gamma operator), and appropriate areas were recognized and checked. The results comparison indicated that among the Fuzzy Gamma values, the value 0, gives a more conservative area of the most suitable class that is much more limited than the other Fuzzy Gamma values. The results by Fuzzy Gamma value equal to 0 shows that 97.51% of the study area is unsuitable, 1.91% least suitable, 0.54% moderately suitable and 0.15% is most suitable for landfill construction. [ABSTRACT FROM AUTHOR]

Recently, a considerable number of research and development projects have focused on automatic vessels. A highly realistic simulator is needed to validate control algorithms for autonomous vessels. For instance, when considering the automatic berthing/unberthing of a vessel, the effect of wind in such low-speed operations cannot be ignored because of the low rudder performance during slow harbor maneuvers. Therefore, a simulator used to validate an automatic berthing/unberthing control algorithm should be able to reproduce the time histories of wind speed and wind direction realistically. Therefore, in our first report on this topic, to obtain the wind speed distribution, we proposed a simple algorithm to generate the time series and distribution of wind speed only from the mean wind speed. However, for wind direction, the spectral distribution could not be determined based on our literature surveys, and hence, a simple method for estimating the coefficients of the stochastic differential equation (SDE) could not be proposed. In this study, we propose a new methodology for generating the time history of wind direction based on the results of Kuwajima et al.'s work. They proposed a regression equation of the standard deviation of wind direction variation for the mean wind speed. In this study, we assumed that the wind direction distribution can be represented by a linear filter as in our previous paper, and its coefficients are derived from Kuwajima's proposed equation. Then, as in the previous report, the time series of wind speed and wind direction can be calculated easily by analytically solving the one-dimensional SDE. The joint probability density functions of wind speed and wind direction obtained by computing them independently agree well with the measurement results. [ABSTRACT FROM AUTHOR]

Surface‐based temperature inversions (SBIs) are frequent and strong in valleys of north‐central Yukon, which drive annual average surface lapse rates that are strongly inverted (≤1.19°C 100 m−1) within the first 100 to 150 vertical meters. This study aims to test the relationship of SBI breakup with local microclimate factors determining the influence on surface lapse rate breakup patterns. A field study was conducted using elevational transect analysis. SBI breakup in the non‐winter season had a strong relationship between the diurnal cycle of increased solar radiation, warming of the surface, and development of atmospheric turbulence in the form of increased wind speed. SBIs during these non‐winter seasons had a peak breakup time of 4 to 8 h following sunrise. Wintertime SBIs often persisted past the diurnal cycle and broke up independent of solar radiation, contributing significantly to the inverted average surface lapse rates. Mechanisms of SBI breakup during the winter are likely more synoptic in nature and one possible mechanism could be shallow cold air flows. Current classification of SBI duration as persistent or transient was reviewed and adjusted, and SBIs with a duration of 18 to 22 h were removed due to the breakup of those events being related to the diurnal cycle. Key messages: Non‐winter surface‐based temperature inversions (SBIs) primarily dissipate in association with the diurnal cycle of increased solar radiation warming the surface.Wintertime SBI breakup is not driven primarily by the same diurnal cycle, as solar radiation alone is not sufficient, leading to semi‐permanent wintertime SBIs.SBIs that are 18 to 22 h in duration were frequently still broken up diurnally, and therefore the persistent SBI event duration classification should be revised to ≥24 h. [ABSTRACT FROM AUTHOR]

With the increasing lifespan of bridges, various forms of deterioration will inevitably occur. The bridge health monitoring system enables direct monitoring of the loads (such as wind, temperature, and vehicles) experienced by the bridge during operation, as well as the corresponding vibration response of the bridge structure (including main beam deformation, tower top displacement, cable acceleration, etc.). These data provide valuable insights into the safety and durability of the bridge during its operational lifetime. However, the challenge lies in extracting meaningful information from the vast amount of collected data. This article focuses on the Fuyu Bridge as a research case and analyzes the variations in environmental factors, such as temperature, humidity, wind load, and structural vibration responses (main beam and cable), obtained from the Fuyu Bridge's structural health monitoring system. It also conducts a structural safety assessment during the operational period of the bridge. Furthermore, the research explores the relationship between environmental factors, load effects, and structural response to establish a foundation for future structural safety assessments of the Fuyu Bridge during its operational period. For instance, changes in environmental factors or load effects can be used to predict structural responses. Additionally, this study provides access to the structural health monitoring data of the Fuyu Bridge, facilitating data‐driven research for other scholars in the field. [ABSTRACT FROM AUTHOR]

The greenhouse environment suitable for crop growth usually depends on reasonable ventilation, and outdoor air flow state and indoor crop height are important factors affecting the ventilation effect. This study conducted simulation and experimental research on corn cultivation in an eight-span plastic greenhouse, analyzing the effects of outdoor wind speed, wind direction, and indoor crop height variations on the uniformity of temperature and relative humidity distribution as well as the air flow dynamics within the greenhouse. The study shows that as outdoor wind speed increases from 0.5 m/s to 2.5 m/s, for every 1 m/s increment, temperatures decrease by 2.2 °C and 0.9 °C, respectively. The increase in outdoor wind speed resulted in uniformity of greenhouse temperature and humidity along the vertical height, but exacerbated the degree of inhomogeneity in the east-west direction. The change in outdoor wind direction leads to differences in airflow direction and ventilation volume. On the south side of the greenhouse, while temperature is lower, the relative humidity is higher, with maximum differences in temperature and humidity between the north and south sides being 0.6 °C and 1.5 %, respectively, when the northeast wind blows. The east wind has the best cooling effect. The uneven degree of temperature and humidity distribution in the east and west direction of the greenhouse is positively correlated with crop height. This study can provide valuable insights for adjusting and optimizing natural ventilation strategies in large multi-span greenhouses.

Influences of animals, time of day, air temperature and relative humidity, wind speed and direction on ammonia concentrations were investigated. A case study on a typical summer day from 7:00 to approximately 24:00 CEST (moderate wind speed, variable cloudiness and maximum global radiation higher than 950 W/m2) in west–central Poland is presented. Concentrations of this gas were measured at four heights (0.1–1.5 m), which were changed every 5 min, using a Nitrolux 1000 photoacoustic spectrometer. A micrometeorological station was established to also measure the surface energy budget components. The results presented are the average for each hour and for the entire day. The fine structure of concentration profiles, plume detection and uncertainty of ammonia flux calculation are also presented. The highest NH3 concentrations were at a 0.5 m height between 16:00 and 17:00 h when cows were grazing, but the lowest concentrations were between 23:00 and 24:00 h at the height of 1.5 m. The ammonia concentration increased with increasing air temperature and was the highest with a westerly wind direction and decreased with increasing air relative humidity. The greatest influence on the ammonia concentration was related to the presence of cows and the time of day, while a slightly smaller influence was noted in terms of air temperature and wind direction. A case study is suitable for presenting local effects, inhomogeneities and quantifying uncertainties in the bidirectional ammonia flux calculation. [ABSTRACT FROM AUTHOR]

The study presented in this article focuses on the temporal dynamics of wind energy production at the Taïba Ndiaye wind farm in Senegal, with a capacity of 158.7 MW. The monthly and seasonal distribution of production shows a strong trend, with maximums recorded between December and May (winter and spring) at around 1800 MWh, and minimums between July and November (summer and autumn) with production below 500 MWh. The diurnal cycle representation exhibits variation with a marked cycle, particularly between November and April. Night-time production is higher than daytime production by more than 43%. The effects of 100-m wind on the farm production are also analysed and show a positive correlation between wind speed and production throughout the year. Production peaks observed in winter and spring are caused by strong winds (approximately 8.5 m/s), while the lowest levels recorded during the summer season are due to weather conditions characterized by weak winds (less than 4 m/s). Similarly, optimal wind directions are observed in winter and spring, periods of maximum production, when the winds blow between the northwest and northeast. [ABSTRACT FROM AUTHOR]

Lake of the Woods spans two geological regions: the Precambrian Shield and the Glacial Lake Agassiz Lakebed. The lake watershed's complex topography influences wind speeds and directions. We study wind variability over Lake of the Woods using reanalysis data and wind observations at seven sites. A wind variability index is proposed as a measure of lake-wide spread in wind direction. Our results show that the directional variability depends on wind speeds, with higher variability at lower speeds. The wind variability also changes throughout the year; it is more pronounced in spring (Apr-Jun) and fall (Sep-Oct) and less pronounced during winter (Dec-Jan). Observed wind directions are 60% more variable than reanalysis wind, indicating a need for higher-resolution reanalysis to resolve local wind effects due to topographic changes. Based on the statistical hierarchical clustering method, our analysis shows that geographically variable wind can be grouped into three regions to represent the predominant wind directions accurately. Clustering results also suggest spatial coverage gaps in the existing meteorological observation network. We reassess the existing network and propose a new meteorological observation site in the southeast basin near Morson, Ontario. Our study is of significance for water quality management because the wind is the key driver of water circulation, transport, and mixing in the lake, and accurate wind measurements are necessary to better constrain the underpinning physical, biological, and biochemical processes in mechanistic ecological models. [ABSTRACT FROM AUTHOR]

The autonomous operations of marine vehicles have recently attracted significant attention. In particular, automation of harbor operations, such as autonomous docking or berthing, is a challenging target. In low-speed harbor operations, the external disturbance of wind is a non-negligible factor. Therefore, the stochastic behavior of gusty wind should be considered in numerical simulations. This study presents a practical computational scheme for generating random wind velocity fields. In the proposed method, the von Kármán's spectrum [1] and Hino's wind speed spectrum [2] were fitted by a degree of freedom (1DoF) filter driven by the Wiener process. The corresponding Itô's equation had the form of the Ornstein–Uhlenbeck process. By employing the analytical solution of the Ornstein–Uhlenbeck process, the wind process was successfully generated without time series repetition. Furthermore, the wind speed and direction processes were also generated from the measured drift and diffusion terms. The spectra of these numerical results are consistent with the observed spectra. [ABSTRACT FROM AUTHOR]

Mapping radon (222Rn) distribution patterns in the coastal sea is a widely applied method for localizing and quantifying submarine groundwater discharge (SGD). While the literature reports a wide range of successful case studies, methodical problems that might occur in shallow wind-exposed coastal settings are generally neglected. This paper evaluates causes and effects that resulted in a failure of the radon approach at a distinct shallow wind-exposed location in the Baltic Sea. Based on a simple radon mass balance model, we discuss the effect of both wind speed and wind direction as causal for this failure. We show that at coastal settings, which are dominated by gentle submarine slopes and shallow waters, both parameters have severe impact on coastal radon distribution patterns, thus impeding their use for SGD investigation. In such cases, the radon approach needs necessarily to allow for the impact of wind speed and wind direction not only during but also prior to the field campaign. [ABSTRACT FROM AUTHOR]

Even though wind, water depth, and shear stress are important factors governing sediment resuspension in lakes, their actual relations to total suspended solids (TSS) distribution in natural environments have not been well elucidated. This study aims to elucidate the impact of the wind on the spatio-temporal variation of TSS in Tonle Sap Lake, Cambodia, during low-water (March and June, R2 = 0.49) than the vectorized average (R2 = 0.30) and inverse of the ratio of distance (R2 = 0.31). Spatial interpolation showed that the wind speed and direction on the lake were 50 mg/L) than that in the high-water season. The TSS concentration during the low-water season was empirically described by wind speed (W), water depth (D), and shear stress (τ_wave) with a function of W3, W3/D, and exp(W/D) or exp(τ_wave), depending on the location in the lake. The critical shear stress due to wind-induced waves at most of the places in the lake was higher than the total shear stress indicated. Sedimentation was predominant in December and June, and erosion (siltation) was dominant in March. Most of the siltation in March was dominant in the southern part of the lake.

BACKGROUND: This work reports a combined, field‐scale spray drift deposition and plant bioassay study for a pre‐mixture of the herbicides mesotrione and s‐metolachlor. Wind direction data and field dimensions were used to evaluate the potential for spray drift to bypass downwind sampling devices. Variability in resulting spray drift across downwind distances was assessed alongside wind speed measured at on‐site weather stations. Measured wind angles were used to geometrically adjust traveled drift particle distances and enabling isolation of wind direction impact from wind speed. Further, the use of single and multiple in‐field monitoring locations was compared to quantify the benefit of higher‐resolution meteorological sampling. RESULTS: Generally, increased wind speed resulted in significantly greater herbicide deposition at distances proximal to the edge of the spray zone. According to the drift deposition curves that included wind speed data from single and multiple onsite weather stations, trials with relatively higher wind speeds were associated with greater spray drift deposition at relatively close sampling distances downwind from the application area. Only marginal improvement of linear mixed‐effects model fit was observed when including data from three weather stations, compared to the fit from a single weather station or absence of weather data in the model. Using tomato and lettuce plant bioassay species, the overall no‐effect distance was 3.0 m (10 ft). CONCLUSION: Results from this study are informative to refine pesticide risk assessment for non‐target plants and indicate that a single weather station is sufficient to capture potential influential effects from wind speed and direction on spray drift. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The objective of this research work is to analyze wind characteristics and to assess wind power potential by selecting the best fit probability distribution function of Jhimpir Sindh Pakistan. This type of detailed investigation helps wind power generation companies in selecting suitable wind turbine and provides information of wind characteristics of potential site. Eight probability distribution functions are tested on the wind speed data from January 2015 to July 2018. Frequency bins of Weibull and Rayleigh distribution with maximum probabilities of 0.1210 and 0.1143 are most closest representation of our data. In order to, quantitatively analysis which distribution function is best fitting the local wind regime, we have applied the coefficient-of-determination, Kolmogorov-Smirnov, Chi square, Cramer-von Mises, Anderson-Darling tests along with Akaike information and Bayesian information criterion. These statistical test are used to rank the empirical distribution functions in order to identify two distribution function better fitting the actual wind speed data. After selecting two best fitted distribution functions, we analyze wind power potential and compare the error of wind power density based on these distribution functions (Weibull and Rayleigh). The power densities reported varied from 73.67 to 648.73W/m2. Results indicate that power densities of Weibull and Rayleigh for the candidate site are 84.67–698.65W/m2 and 83.67–1021.4W/m2, respectively. The highest error for Weibull and Rayleigh are 0.1850 and 0.5745, respectively. Whereas lowest error are 0.0178 and 0.0180, respectively. Complete analysis suggested that Weibull distribution function is the most suitable for Jhimpir Sindh Pakistan and the studied site is suitable for wind power production. In addition, comprehensive analysis of wind direction at the candidate site suggested that Eastern and Southeastern wind directions are predominant with 38.52% and 33.24% of the total time.

This study strives to present a preliminary assessment of wind characteristics and the regime for Cappadocia Airport in Turkey by in-depth a holistic and precise comparative analysis. For this purpose, the parameters of the well-accepted Weibull distribution, namely shape and scale parameters, are determined by a variety of estimation methods. Furthermore, the distribution of wind direction and speed over a period of 2015 and 2017 is investigated. Several well-known statistical tools, including Root Mean Square Error (RMSE), R-squared (R2) and Chi-squared (X2), are conducted to analyze comparatively the fitting performance and efficiency of the estimation methods to wind data. This study reveals that the wind speed remains equal to or greater than around three (m/s) 61.12% of the time and the prevailing wind direction is between 290o and 335o, consistent with the runway orientation. The value of the shape parameter ranges from 2.4368 to 4.093, while the scale parameter is in the range from 3.4793 to 4.2349. Consequently, in light of the statistical indicators, it is clearly observed that Empirical Method of Justus (EMJ) and Empirical Method of Lysen (EML) with RMSE of 0.0392, R2 of 0.9865, and X2 of 0.0016, respectively, exhibit more excellent ability in estimating the Weibull parameters in comparison with other numerical methods and also are the most suitable methods in determining the wind characteristics and wind profile of the airport. This study may attract the attention of academics, industrial researchers and policymakers intending to establish the runway orientation at an airport. [ABSTRACT FROM AUTHOR]

The cooling performance of air-cooled condenser (ACC) is susceptible to adverse impacts of ambient winds. In this work, three kinds of lateral double-layered deflectors installed under the ACC platform are proposed to weaken the unfavorable effects of cross winds. Through CFD simulation methods, the main parameters of thermo-flow performances of a 2×660 MW direct dry cooling system are obtained, by which it can be concluded that the deflectors can effectively reduce the inlet air temperatures while enhance the mass flow rates of upwind fans due to the guiding effect, especially at high wind speeds, while the improvement of cooling capacity of ACCs in the 0° wind direction is weak. The inclined-vertical deflectors are superior to others in performance improvement of ACCs for all cases, which can reduce the turbine back pressure by 12.15% when the wind speed is 12 m/s, so they can be applied to the performance enhancement of ACCs under windy conditions in practical engineering. [ABSTRACT FROM AUTHOR]

This study focuses on modelling tropospheric ozone using neural networks to predict its concentration depending on environmental parameters. Predicting tropospheric ozone concentration is an important task, especially in recreational areas, since it harms human health. Considering the great complexity in describing the mechanisms of formation and destruction of tropospheric ozone and their dependence on a number of factors (temperature, humidity, pressure, wind speed and direction) the authors have suggested using Neural Networks to predict it. The selection of the network configuration and the algorithm for its training largely depends on the type of initial data available to researchers. The following fundamental factors were taken into account: temperature, humidity, and wind direction. The selected Neural Networks have been applied to a dataset obtained from the Russian Federation. From the obtained results, the best forecasting accuracy was achieved by using a Feed-Forward Back-Propagation Artificial Neural Network with 3 layers. The accuracy of prediction of the artificial neural networks against the measured data was evaluated using the Index of Agreement (IOA), which was estimated at 0.87, which equals other work in this field. This level of accuracy is equivalent to previous advances, but the standard software and built-in neural network configurations were used. The presented results have also confirmed that the wind speed and direction have a significant impact on the forecast accuracy – excluding wind speed reduces the IOA to 0.839; excluding wind speed and direction reduces the IOA to 0.0.807.

Based on the measurement data obtained during the 121th cruise of the RV Professor Vodyanitsky , regularities were established between spatial distribution of quantitative characteristics and phytoplankton species composition, chlorophyll a concentration, and hydrometeorological parameters of the environment on the southern Crimean coast in the spring 2022. Chlorophyll a concentration was compared with satellite observation data of high spatial resolution. In selected areas with different shelf depths, the features of the distribution of phytoplankton indicators under conditions of changing hydrometeorological parameters were studied. The mechanisms of vertical water exchange were described. In coastal waters of the Crimea (Foros–Novy Svet), with intense western wind contributing to Ekman upwelling and low water temperature is a consequence of the upwelling, rather high values of phytoplankton biomass and abundance and chlorophyll a concentration were recorded, which were accompanied by the highest values of oxygen content. In the area of Sudak–Feodosiya, with intense northeastern wind and waves and with quite high water temperature, low dissolved oxygen, low values of phytoplankton biomass and abundance and chlorophyll a concentration were registered. Apparently, in Sevastopol area, Ekman upwelling arises under the effect of northern and northwestern winds. In three regions, dinoflagellate microalgae prevailed in spring 2022 in phytoplankton biomass. Those accounted for 52, 66, 81 % of the total number of species identified in the regions: Foros–Novy Svet, Sudak–Feodosiya, near Sevastopol, respectively. Thus, the main mechanisms were analyzed, which drive spatial distribution of quantitative characteristics and species composition of the phytoplankton community in the Crimean coastal water area with different shelf depths in spring. • The mechanisms of vertical mixing are studied.. • Particular attention is paid to the effect of wind–wave characteristics on phytoplankton distribution in the shelf areas on the southern Crimean coast (Black Sea) in spring. • Western and southwestern winds positively affect the phytoplankton on the Foros–Yalta area. Northeastern winds and waves adversely affect phytoplankton abundance in the Sudak–Feodosiya area. • The prevalence of dinoflagellates in phytoplankton biomass is determined. [ABSTRACT FROM AUTHOR]

Environmental wind is a random phenomenon in both speed and direction, though it can be forecasted to some extent. An example of that is a gust which is an abrupt, but short-time change in wind speed and direction. Being a free and clean source for small-scale energy scavenging, attraction of wind is rapidly growing in the world of energy harvesters. In this paper, a leaf-like flapping wind energy harvester is introduced as the base structure in which a short-span airfoil is attached to the free end of a double-deck cantilever beam. A flap mechanism inspired by scales on sharks' skin and a tail mechanism inspired by birds' horizontal tail are proposed for integration to the base harvester to make it adaptive with respect to wind speed and direction, respectively. The use of the flap mechanism increases the leaf flapping frequency by +2.1 to +11.5 Hz at wind speeds of 1.5 to 6.0 m s -1 . Therefore, since the output power of a vibrational harvester is a function of vibration frequency, a figure of merit or an efficiency parameter related to the output power will increase, as well. On the other hand, if there is a misalignment between the harvester's heading and wind direction due to change of the latter one, the harvesting performance deteriorates. Although the base harvester can realign in certain ranges of sideslip angle at each wind speed, when the tail mechanism is integrated into that, it broadens the range of realignable sideslip angles at all the investigated wind speeds by up to 80∘., (Creative Commons Attribution license.)

The odor pollution is a real problem that could threat a city and influence negatively the health of people. The odor is formed from invincible substances and several previous researches in both fields of chemical and meteorological specialization have created visualization maps for odor as an intending to locate the odor source, substances, and affected areas. This research aims to benefit from previous studies in the architectural field in providing a visualization for the odor in the city especially in the residential areas. The objective of the research is to create an assessment of the odor sources and affected residential areas in three different settings in Tripoli city, as a smellscape with considering one environmental factor that is the wind as an influencing element in the dispersion of odor in the city. The study depends on ArcGIS map to set the odor different location sources, and the affected residential areas by these sources in Tripoli city. The study of wind is conducted based on the GFS model (Global Forecast System) to find out the changed wind direction and speed between 21st to 31st of May in Tripoli city. The data collected is visualized as first in pivot tables for each wind speed category, these tables help to find out the role of wind in the dispersion of odor in each of the selected residential areas. The results show that visualizing the data in pivot tables helps in conducting the influence of wind in spreading the odor in the selected residential areas in Tripoli city. The outcome of this study is to benefit from the wind study to define one of the factors that influence the odor dispersion in each of the selected areas and according to the different odor sources that help in assessing the odor pollution in each area. [ABSTRACT FROM AUTHOR]

The original MicRAWinD (Microwave Radiometric Algorithm for Wind Direction retrieval) algorithm planned for use in reconstructing the near-surface wind direction in the Convergence space experiment (SE) is presented. The possibility of determining the wind direction based on radiometric measurements in two swaths of the radiometer stems from the anisotropy of surface radiation, which is manifested most clearly in the third Stokes parameter. Combining the results of measurements at different frequencies with their reliability factored in, one can improve the accuracy of reconstructing the wind direction. A new algorithm for enhancing the reliability of measurements which takes the real errors in measuring brightness temperatures into account is proposed. The algorithm has been tested with real data provided by the WindSat radiometric system. The results are compared with the Remote Sensing Systems (RSS) reconstruction data. A surface region with different geophysical parameters (sea surface temperature, vapor content, wind speed and direction, and cloud water content) is chosen for this comparison. The reconstruction algorithm involves solving the direct problem of calculating the radio brightness temperatures at linear ±45° polarizations with subsequent calculations of the third Stokes parameter for 37, 18.7, and 10.7 GHz. The initial meteorological parameters for the direct problem are products provided by RSS. The sensitivity of radiometric instruments is taken into account in the simulation process. The solution of the inverse problem and the comparison results demonstrate that this algorithm retrieves the wind direction with fine qualitative agreement both from the results of radiometric observations at a single frequency and from multifrequency data. [ABSTRACT FROM AUTHOR]

Although ultrasonic wind meter is widely used in wind speed measurement, the disadvantages of the ultrasonic wind meter structure by its measurement way still exist. The ultrasonic probe will stop on the way of the wind, which in turn produces a shadow area at the back of the probe, probe produce turbulence ahead. Therefore, it will result in error during the process of our normal wind speed measurement. At present, the ultrasonic wind speed Angle compensation formula is deduced by using the wind speed compensation formula on the path. The measurement data and the compensation formula are used for fitting comparison. It is observed that the Angle compensation function of wind and ultrasonic path fits well with the measured data, and the wind speed error after compensation is reduced from 14.65 % to 1.74 %. The modified measurement of accuracy of wind speed and direction can be used in two-dimensional ultrasonic orthogonal wind array model. [ABSTRACT FROM AUTHOR]

This paper presents a novel copula-based approach to model the joint cumulative distribution function (JCDF) of wind speed and direction for wind-resistant design of engineering structures. Copula functions enable the JCDF to be obtained with the corresponding marginal distributions of wind speed and wind direction. The daily maximum wind speed recorded during 1971–2017 in Dali, China, was collected and used as the data source. The Weibull distribution was applied to represent the marginal distribution of wind speed; meanwhile, the marginal distribution of wind direction was modeled by the von Mises distribution. The Farlie-Gumbel-Morgenstern (FGM) and four commonly used Archimedean copulas were employed to construct the continuous bivariate JCDF of wind speed and direction. The simulation results were compared with those obtained using the traditional methods, i.e., the approaches based on multiplication rules and angular-linear (AL) model. The statistics of the coefficient of determination R2 and root-mean-squared error (RMSE) obtained in the regression analysis were used to judge the goodness of fit of each approach. The analytical results show that the approach based on copulas can not only yield good JCDF estimations of wind speed and direction, but also provide an effective and practical way to predict the extreme wind speed at a certain return period. Moreover, the estimated extreme wind speed varies significantly in the 16 directions and the predicted extreme wind speed in the studied region will be unreliable when neglecting the joint effect of wind speed and direction. [ABSTRACT FROM AUTHOR]

Information about wind is widely used in many sectors of the economy. Wind also causes many dangerous and extreme weather events. Modern climate changes require a certain revision of weather patterns previously accepted for the area. This article provides information on the current space and time distribution of wind characteristics within the territory of Morocco. During the period of 2005-2014 some monthly average wind speed values and data on repeatability of wind directions by gradations were obtained on the basis of physical and statistical analysis of results of observations of wind speed and directions performed at 26 stations . The authors defined the character of distribution of monthly averages of wind speed within the territory and its seasonal changes. Most of the territory is covered by mountains of Morocco which encourages development of local winds. At central and northern regions of Morocco predominance of weak winds due to complex orography of terrain is observed. In the central part of Morocco there is a region with the lowest values of wind speed. Formation of the wind regime at the coastal stations takes place in a developed breeze circulation. Wind speed and direction are significantly different at the nearby stations, such as Larache and Chefchaouen, Meknes and Fez. Increase of wind during the warmer half of a year was revealed at all stations. Nature of annual variation of average wind speed at the stations allows us to split the stations into two groups. The first group includes the stations where the average wind speed increases in summer and decreases in winter. The second group includes the stations where the average wind speed increases in spring and decreases in autumn. In the southern part and along the coast, where the terrain is flat, an increase of wind speed is observed. On open plains of the southern part of Atlantic coast during all seasons wind has a direction corresponding to direction of trade winds of the Northern hemisphere. It should be noted that the main factor forming air circulation within the territory of Morocco is represented by trade winds the intensity of which nearly doubles from summer to winter. Formation of wind directions at the stations takes place mainly under the influence of terrain of the area. At many stations predominant wind direction in January changes by 180º in comparison to the respective July values. Therefore, characteristics of the wind regime of Morocco in 2005-2014 consist in increase of wind speed in the coastal zone and decrease thereof in mountain areas together with presence of two types of annual variation of wind speed depending on physical and geographical conditions.

Fugitive particle emission of enclosed storage yards in iron and steel plant is a complicated and multivariable problem, which will have negative impacts on the environment and economy. Researchers have discussed methodologies of emission estimation in open storage yards, but rarely focused on enclosed ones. However, enclosed storage yards are commonly adopted in most industries in China. This paper links onsite observation and computational fluid dynamics (CFD) to estimate the impact of fugitive PM10 emissions from enclosed storage yards on the open air. By collecting and analyzing PM10 samples at three sites inside the yard and one site outside, The result shows that PM10 concentration is in the range of 7.3 ± 1.5~13.4 ± 4.2 mg/m3, which is extremely high in an enclosed storage yard, and significantly influences workers’ health inside and outside atmospheric aerosols. The CFD model simulation is conducted by considering particle deposition, particle emission sources of shovel loader and road dust emission, as well as different wind direction and wind speed. The result shows that PM10 discharge rate from the enclosed area to open-air is significantly influenced by wind velocity and direction, e.g., the result of northwest wind with wind speed in 12.7 m/s is eight times higher than wind speed in 2.5 m/s with the same wind direction, and are 47 and 62 times higher than the east and west wind direction with the same wind speed in 12.7 m/s, respectively. In this case, the PM10 discharge rate is about 131.7 ton/year, which contains about 38~55 ton/year iron-relating particles. This will directly contribute PM10 to open-air and may produce secondary aerosols, due to heterogeneous catalytic reaction. This work identifies the important contribution of fugitive emissions and provides an approach for fugitive emission estimation of industries to the surrounding air. The results provide a reference for material yard zoning and fugitive emission control from minimizing influence from the meteorological condition and reducing source discharge inside.

Abstract: This paper presents an analysis of the experimental measurements of the azimuthal anisotropy of the microwave emissions of a rough water surface. The experimental data were obtained using microwave radiometers with operating frequencies of ~37 GHz (a wavelength of ~8 mm) on the oceanographic platform of the Black Sea Hydrophysical Experimental Facility of the Russian Academy of Sciences in the period from 2005 to 2016. This paper describes the azimuthal anisotropy effect, experimental studies, measurement methods, and data processing. A qualitative comparison of the measurement results with the model calculations and other experimental studies of anisotropy was performed. It was shown that there is a strong sensitivity of the variation in the radio emissions of a rough water surface, both to the wind speed and to its direction at different incidence observation angles. [ABSTRACT FROM AUTHOR]

Vehicle wind speed measurement has always been a vital issue when assessing the aerodynamic performance of a high-speed train in cross winds. Conventional anemometers are not applicable in the extreme environment caused by trains. In this paper, a new wind speed measurement method is proposed, and a cylindrical anemometer to simultaneously measure the wind speed and direction is presented. The instrument consists of a cylinder with 12 evenly distributed holes that connect to 12 differential pressure sensors. Thus, the pressure distribution developed by the wind on the lateral surface of the cylinder is obtained. Then, theoretical relations among three neighboring pressure maxima and the wind speed and wind direction are formulated and validated with a wind tunnel test, where the fabricated anemometer is rotated at 10° intervals under a wind speed of 5–60 m/s. Field tests are conducted to assess the environmental adaptability of the proposed anemometer. The experimental results show that the proposed method and developed anemometer can be applied for air flow measurements and have high accuracy, reliability, and durability. [ABSTRACT FROM AUTHOR]

The work addressed a study on pollution caused by traffic on the highway. In particular, it was considered the concentration of pollutant, resulting from the passage of vehicles on the freeway. Five different stations (sensors and samples) used to collect data. The data collection period around six months. Also, the following parameters were detected: wind speed and direction, temperature and traffic flow rate. Data processed with Multivariate Analysis and Artificial Neural Network approach. The best model it obtained with Artificial Neural Network approach. In fact, this model presented the best fit to the experimental data.

Wind speed and direction are important parameters in meteorological observation. A solid wind sensor is needed with a small quadcopter for boundary layer meteorological observation. In this paper, the principle of a cylindrical two-dimensional wind sensor is reported and the data from wind tunnel experiments are analyzed. A model is proposed to describe the distribution of the pressure difference across a diameter of a cylinder, and the wind sensor is fabricated with MEMS (Micro-Electro-Mechanical System) differential pressure sensors. The wind sensor cylinder has a small size with a diameter of 30 mm and a height of 80 mm. In wind tunnel tests in the range of 1 to 40 m/s, the relative speed measuring errors and the direction measuring errors of the prototype are no more than ± (0.2 + 0.03 V) m/s (V is standard wind speed) and 5°, respectively. An inclination angle model is proposed to correct the influence of tilt angle on the quadcopter platform, the wind sensor can maintain the original wind speed and direction measurement accuracy within the 30° inclination range after compensation.

Gaining knowledge on weather patterns, trends and the influence of their extremes on various crop production yields and quality continues to be a quest by scientists, agriculturists, and managers. Precise and timely information aids decision-making, which is widely accepted as intrinsically necessary for increased production and improved quality. Studies in this research domain, especially those related to data mining and interpretation are being carried out by the authors and their colleagues. Some of this work that relates to data definition, description, analysis, and modelling is described in this paper. This includes studies that have evaluated extreme dry/wet weather events against reported yield at different scales in general. They indicate the effects of weather extremes such as prolonged high temperatures, heavy rainfall, and severe wind gusts. Occurrences of these events are among the main weather extremes that impact on many crops worldwide. Wind gusts are difficult to anticipate due to their rapid manifestation and yet can have catastrophic effects on crops and buildings. This paper examines the use of data mining methods to reveal patterns in the weather conditions, such as time of the day, month of the year, wind direction, speed, and severity using a data set from a single location. Case study data is used to provide examples of how the methods used can elicit meaningful information and depict it in a fashion usable for management decision making. Historical weather data acquired between 2008 and 2012 has been used for this study from telemetry devices installed in a vineyard in the north of New Zealand. The results show that using data mining techniques and the local weather conditions, such as relative pressure, temperature, wind direction and speed recorded at irregular intervals, can produce new knowledge relating to wind gust patterns for vineyard management decision making.

Indoor pollen concentrations are an underestimated human health issue. In this study, we measured hourly indoor birch pollen concentrations on 8 days in April 2015 with portable pollen traps in five rooms of a university building at Freising, Germany. These data were compared to the respective outdoor values right in front of the rooms and to background pollen data. The rooms were characterized by different aspects and window ventilation schemes. Meteorological data were equally measured directly in front of the windows. Outdoor concentration could be partly explained with phenological data of 56 birches in the surrounding showing concurrent high numbers of trees attaining flowering stages. Indoor pollen concentrations were lower than outdoor concentrations: mean indoor/outdoor (I/O) ratio was highest in a room with fully opened window and additional mechanical ventilation (.75), followed by rooms with fully opened windows (.35, .12) and lowest in neighboring rooms with tilted window (.19) or windows only opened for short ventilation (.07). Hourly I/O ratios depended on meteorology and increased with outside temperature and wind speed oriented perpendicular to the window opening. Indoor concentrations additionally depended on the previously measured concentrations, indicating accumulation of pollen inside the rooms even after the full flowering period. [ABSTRACT FROM AUTHOR]

Wind speed and direction are important parameters in meteorological observation. Solid wind sensor has needed with small Quadcopter for boundary layer meteorological observation. In this paper the principle of a cylindrical two-dimensional wind sensor is reported by analyzing the data from wind tunnel experiments. A model is proposed to describe the distribution of the pressure difference across a diameter of a cylinder and the wind sensor is fabricated with MEMS differential pressure sensors. In wind tunnel tests in range of 1~40 m/s, the relative speed measuring errors and the direction measuring errors of the prototype are no more than ±(0.2 + 0.03 V) m/s and 5° respectively.

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Copyright of Vatten is the property of Foreningen Vatten and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The simulation of synthetic wind time series is strictly necessary, among others, to assess the risk of structures and systems, to model the dynamic of morphological features like dunes, or to investigate the potential of wind energy in a certain location. For all these applications, a tool able to simulate time series of wind speed and direction is required. In this paper we propose a methodology for the simulation of bivariate non-stationary time series of wind speed and direction. This methodology takes into account the circular nature of the wind direction, as well as the mean annual cycle of both wind speed and direction. For modelling the joint distribution of the two variables, wind speed is modelled conditioned to the wind direction. For modelling short-term self- and cross-dependency among the variables a Vector Autoregressive (VAR) model of order p is used, with an innovation process at time t that depends on the value taken by the variables at time t −1, based on the use of a mixture of multivariate normal distributions. The proposed methodology is applied to a case study, simulating several synthetic series, of the same length as the original series. The simulated series satisfactorily captures the characteristics of averaging or common data (i.e. with low or moderate speed) and, under certain independence conditions, the directional extreme value distribution of the wind speed is also properly reproduced. [ABSTRACT FROM AUTHOR]

Using three daily measurements of wind speed and direction from synoptic weather station data in SE Niger, we examined the diurnal, seasonal and interannual time-scale of Sahel climate variability between 1950 and 1992. The seasonal wind patterns are closely related to the temperatures and West African monsoon dynamics. The transitions between the two seasons are marked by an important increase in calms (wind speed < 0.5 m s −1 ). Such variations are related to meridional shifts of the Inter Tropical Discontinuity (ITD) and Inter Tropical Convergence Zone (ITCZ). Interannual fluctuations of annual wind speeds are consistent with Sahel rainfall variability. Dry years, such as in 1969–1973 and 1983–1986 periods, are associated with negative anomalies in wind speeds mainly due to an increase in calms and dry conditions. Nevertheless, we note several differences: the first period is associated with a yearly increase in the annual mean speed, while the second is associated with a decrease. Differences could be related to changes in atmospheric circulation, especially regarding the strength and latitudinal position of Tropical and African Easterly jets. [ABSTRACT FROM AUTHOR]

In this paper, curve-fitting and intensity-level-selection (ILS)-based algorithms for wind parameter extraction from shipborne X-band nautical radar images are investigated. First, to exclude the rain cases and low-backscatter images, a data quality control process is designed for both algorithms. An additional process is then introduced for the ILS-based method to improve the accuracy of wind measurements, including the recognition of blockages and islands in the temporally integrated radar images. For the low sea states, a dual-curve-fitting is proposed. These wind algorithms are tested using radar images and shipborne anemometer data collected on the east coast of Canada. It is shown that the dual-curve-fitting algorithm produces improvements in the mean differences between the radar and the anemometer results for wind direction and speed of about 5.7° and 0.3 m/s, respectively, under sea states with significant wave height lower than 2.30 m. Also, a harmonic function that is least-squares fitted to the selected range distances vector as a function of antenna look direction is applied. Compared with the original ILS-based algorithm, the modified procedure reduces the standard deviation for wind direction and speed by about 4° and 0.2 m/s, respectively. Finally, the performance of these two modified methods are compared. [ABSTRACT FROM PUBLISHER]

In China, an increasing number of cyclists commute on urban streets. Cyclists are usually exposed to high traffic-related particulate matter (PM) concentrations. The distribution of cycling exposure concentrations may be affected by meteorological conditions under different street configurations. To investigate these impacts, we collected concentrations of PM 2.5 and PM 10 at the breathing height of cyclists and meteorological data in two differently oriented streets and an open road in Fuzhou. Relative exposure concentrations (RECs) were determined by subtracting the background concentration and monitoring intervals were determined with the minimisation of the coefficient variation of traffic to identify the impacts of meteorology (e.g., wind speed and wind direction) on REC distribution. Wind speed had the most significant impact on REC and explained 26–63% of the variation in REC. Higher RECs (>6 μg/m3) were mainly distributed at lower wind speeds (<2 m/s), while lower RECs (<3 μg/m3) were dominant when the wind speed exceeded 4 m/s. Temperature and relative humidity were not significantly correlated with the REC. Parallel winds can improve the dispersion of particles. In the up-wind condition, RECs on the leeward side were 2 μg/m3 higher than those on the windward side because of the accumulation of particles caused by the vortex effect, especially in the west-east streets with residential roadside buildings with strip pattern features. More building gaps on both sides of the streets could weaken the vortex effect, and RECs on the leeward side decreased faster with increasing wind speed. These results can be used to propose strategies for reducing cycling exposure. • Relative exposure concentration (REC) improved the identification of meteorological factors. • Wind speed can explain 26–63% of the variation in cycling REC. • Parallel wind can better benefit the dispersion of particles. • Buildings with strip pattern features can increase REC on the leeward side. • More gaps between buildings can benefit the dispersion of pollutants in urban streets. [ABSTRACT FROM AUTHOR]

This study evaluated the effect of wind speed and direction and surrounding maize field on the air exchange rate (ACH) and indoor air velocity in a dairy cow building with hybrid ventilation, which combined auto-controlled natural and partial mechanical pit ventilation. The standard k − ε turbulence model and standard wall function were applied in CFD modeling with extension of capability to account for the aerodynamics effect of surrounding maize plant canopy in the wind domain by using user defined functions (UDF). This extended model was validated by on-site measured velocities and temperatures. A reasonably good agreement was found between simulated and measured results. The wind speed influenced ACH greatly while modeling the maize field had little effect on ACH with low wind speed. With wind speed of 3.86 m s −1 in validation case, modeling the maize field reduced total ACH by 24%, ACH via bottom openings on the sidewall by 89.7% and air speed measured upwind by 71%. The results revealed that the plant canopy had the most significant effect on ACH through the opening on the sidewall. With the variation of wind direction from 0° to 90°, the difference of ACH could be 60%. [ABSTRACT FROM AUTHOR]

Gaining knowledge on weather patterns, trends and the influence of their extremes on various crop production yields and quality continues to be a quest by scientists, agriculturists, and managers. Precise and timely information aids decision-making, which is widely accepted as intrinsically necessary for increased production and improved quality. Studies in this research domain, especially those related to data mining and interpretation are being carried out by the authors and their colleagues. Some of this work that relates to data definition, description, analysis, and modelling is described in this paper. This includes studies that have evaluated extreme dry/wet weather events against reported yield at different scales in general. They indicate the effects of weather extremes such as prolonged high temperatures, heavy rainfall, and severe wind gusts. Occurrences of these events are among the main weather extremes that impact on many crops worldwide. Wind gusts are difficult to anticipate due to their rapid manifestation and yet can have catastrophic effects on crops and buildings. This paper examines the use of data mining methods to reveal patterns in the weather conditions, such as time of the day, month of the year, wind direction, speed, and severity using a data set from a single location. Case study data is used to provide examples of how the methods used can elicit meaningful information and depict it in a fashion usable for management decision making. Historical weather data acquired between 2008 and 2012 has been used for this study from telemetry devices installed in a vineyard in the north of New Zealand. The results show that using data mining techniques and the local weather conditions, such as relative pressure, temperature, wind direction and speed recorded at irregular intervals, can produce new knowledge relating to wind gust patterns for vineyard management decision making. [ABSTRACT FROM AUTHOR]

In order to determine the effect of wind-induced waves (influenced by wind velocity and direction) on the dynamics of optical properties in shallow lakes, we determined the short-term variability of the inherent optical properties (IOPs) in Meiliang Bay, Lake Taihu, China, by examining high-frequency data collected between 8 and 21 September 2010 from meteorology and optical sensors. The absorption and beam attenuation coefficients under strong winds were significantly higher than those under weak and moderate winds ( t test, P < 0.001). Significant correlations were found between absorption, scattering, beam attenuation, and wind speed, showing that the hydrodynamic process was an important factor that influenced the instantaneous IOPs of the water. However, the different wind directions have a different effect degree on the IOPs. Western wind is the most important driven wind direction of this site. In addition, significant correlations were found between b(440), c(440), b(677), c(677), b(440), and turbidity under each wind direction ( P < 0.001). Exponential and hyperbolic exponent models of the absorption and beam attenuation coefficients were fitted, and linear models between a(677), c(677), and turbidity were developed. Thus, in shallow lakes such as Lake Taihu, using real-time high-frequency monitoring of the turbidity to deduce the water IOPs could be an efficient and practical approach. Our study will be helpful in monitoring the IOPs and in improving the accuracy of bio-optical models to estimate water quality parameters in Lake Taihu. [ABSTRACT FROM AUTHOR]

Changes and distribution of ozone concentration in the area of high‐voltage transmission lines were investigated. The investigation on ozone concentration changes was performed with application of two methods: by using an ozone analyser and by passive samplers. The role of an accumulating element was performed by a glass‐fiber filter installed in a passive sampler. It was impregnated with a 1.2‐di(4‐pyridyl)ethylene and acetate acid solution. The impact of meteorological parameters on the passive sampler efficiency and ozone concentration variation is discussed. These parameters can increase or decrease the real concentration value in comparison with the concentration obtained by co‐located continuously running ozone analyser. Ozone concentration near high‐voltage lines varied from 10 to 51 ppb, and “background” ozone concentration changed from 3 to 50 ppb during the investigation period. The average concentrations were 28.1 and 27.5 ppb near the lines and “background” during the whole experiment period. The wind direction from “background” location to the high‐voltage lines prevailed during the experiment. The obtained results by different methods demonstrated good agreement; the difference between ozone concentrations was from 1 to 24% for individual cases. Santrauka Tirta ozono koncentracijos kitimas ir pasiskirstymas ties aukštosios įtampos perdavimo linijomis. Ozono koncentracija matuota dviem metodais – ozono analizatoriumi ir pasyviaisiais kaupikliais. Pasyviajame kaupiklyje kaip kaupiantysis elementas buvo naudojamas stiklo pluošto filtras, impregnuotas 1,2-di(4-pyridyl)etileno ir acetatinės rūgšties tirpalu. Vėjo greitis, vėjo kryptis, UV spinduliuotė, temperatūra ir santykinė oro drėgmė gali turėti įtakos pasyviųjų kaupiklių efektyvumui bei ozono koncentracijos pasiskirstymui, todėl kartu tirti ir meteorologiniai parametrai (temperatūra, santykinė oro drėgmė, vėjo greitis ir kryptis). Tyrimo laikotarpiu ozono koncentracija ties aukštosios įtampos tiekimo linijomis kito nuo 10 iki 51 ppb, o nutolusioje per 222 m vietovėje, kuri buvo traktuojama kaip foninė, – nuo 3 iki 50 ppb. Išmatuota vidutinė ozono koncentracija foninėje vietoje buvo 27,5 ppb, o ties linijomis – 28,1 ppb. Eksperimento metu vyravo pietryčių krypties vėjas, t. y. nuo foninės vietos – aukštosios įtampos tiekimo linijų link. Nustatant ozono koncentraciją skirtingais metodais duomenys pakankamai sutapo, pavieniais atvejais nesutapimas svyravo nuo 1 iki 24 %. Резюме Исследовалось изменение и распределение концентрации озона в районе высоковольтных линий электропередач. Концентрация озона измерялась двумя методами: анализаторами озона УФ-поглощения непрерывного действия и с использованием пассивных сорбентов. В качестве сорбента использовался фильтр из стекловолокна, пропитанный 1,2-ди(4-пиридил)этиленом и уксусной кислотой. Параллельно непрерывно измерялась температура и относительная влажность воздуха, скорость и направление ветра. Исследования показали, что концентрация озона в течение эксперимента изменялась в интервале от 10 до 51 ррb у линии и от 3 до 50 ррb на «фоновой» точке, удаленной от линий электропередач на расстояние 222 м. В течение эксперимента почти половину времени преобладал боковой ветер по отношению к высоковольтным линиям со стороны фоновой точки. Средние измеренные концентрации озона составляли 27,5 ррb на «фоновой» точке и 28,1 ррb – у линий. Результаты измерения концентрации озона как анализаторами непрерывного действия, так и по методике с использованием пассивных сорбентов показали хорошее совпадение: разница составляла 2–15% и лишь в отдельных случаях 24%. First Published Online: 14 Oct 2010 Reikšminiai žodžiai: aukštosios įtampos tiekimo linijos, ozono koncentracija, pasyvusis kaupiklis, meteorologiniai parametrai, vėjo greitis, vėjo kryptis, temperatūra, santykinė drėgmė. Ключевые слова: высоковольтные линии электропередач, концентрация озона, пассивные сорбенты, метеорологическиe параметры, cкорость и направление ветра, температура и относительная влажность воздуха.

Short-term wind measurements at a candidate wind turbine installation site strive to capture a fingerprint of candidate site wind conditions. Coupling this fingerprint with a historical data set from a nearby reference station enables the projection of the candidate site's longer-term wind characteristics. This paper focuses on the historic wind datasets compiled by the Meteorological Office of Malta International Airport, Luqa. As the only station having in excess of 20 years of wind speed and direction data, this database is significant and useful as a long-term reference station. The position of the Maltese island makes this station a useful node for weather-related data and for validation of computational tools in the central Mediterranean region. The focus of this paper is primarily on a period when the station and measurement equipment went through an upgrade and relocation. A downward shift of 0.75 ms-1 in the wind speed was identified. The analyses presented in this paper identify and test hypotheses for this shift including aspects such as the station's relocation, the use of new sensors, using a different monitoring structure type and other factors. [ABSTRACT FROM AUTHOR]

Abstract: Ambient winds are one of the key issues in the design and operation of indirect dry cooling system in a power plant. It is of benefit to the optimization of air-cooled heat exchangers and dry-cooling towers to investigate the impacts of ambient winds on the thermo-flow performances of indirect dry cooling system. Based on a representative 4 × 660 MW dry cooling power plant with the flue gas desulfurization and stack installed inside the dry-cooling tower, the physical and mathematical models of the air-side fluid and heat flows at various wind speeds and in various wind directions are developed. The velocity, pressure and temperature fields are presented, and the flow rate and heat rejection for the air-cooled heat exchangers and cooling towers are obtained by using CFD simulations. The results show that the fluid and heat flows of indirect dry cooling system are dominated by the wind induced and buoyancy driven air flows, which are the results of balance between the inertial force, and pressure, viscous and buoyancy forces. In the absence of ambient winds, the hot plume discharge experiences a reverse pressure gradient. The thermo-flow performances of indirect dry cooling system are deteriorated with increasing the wind speed at low wind speeds, but get improved at high wind speeds despite of the hot air penetration through parts of the air-cooled heat exchanger. The frontal finned tube bundles of air-cooled heat exchanger are superior to other finned tube bundles in thermo-flow performances. It will contribute to the proposal of measures against the adverse impacts of ambient winds for the indirect dry cooling system in a power plant. [Copyright &y& Elsevier]

Abstract: Ambient winds may deteriorate the thermo-flow performances of air-cooled condensers, so it is of use to take measures against the adverse impacts of winds upon the air-cooled condensers in a power plant. On the basis of a 2×600MW direct dry cooling power plant, a new trapezoidal array of air-cooled condensers is proposed. The computational models of the air-side fluid and heat flows of the air-cooled condensers in a trapezoidal array at various wind speeds and in various wind directions are developed, and the velocity and temperature fields are presented by using CFD simulations. The volumetric flow rate, inlet air temperature and heat rejection for different condenser cells are obtained and compared with those of the current air-cooled condensers in the rectangular array. The results show that the reversed flows arose in the upwind condenser cells at high wind speeds disappear due to the trapezoidal array of air-cooled condensers, resulting in a lowered inlet air temperature and an increased heat rejection of the upwind condenser cells. The hot plume recirculation in the wind direction of 0° becomes very weak and only appears at one side near the main buildings. The thermo-flow performances are improved to a certain extent thanks to the trapezoidal array of air-cooled condensers. It is recommended that air-cooled condensers in a power plant take the form of trapezoidal array to restrain the adverse impacts of ambient winds. [Copyright &y& Elsevier]

. 1. Farrow light traps have been used in Australia since the 1970s to monitor locusts only, but catch variability has not been explained. Four light traps were operated at North Bourke, northern New South Wales, to study catch variability. 2. Habitat did not influence catch composition (non-metric multidimensional scaling/analyses of similarity) or similarity. Assemblages of Orthoptera differed only modestly between December and March, whereas assemblages of macrolepidoptera differed strongly between December, March and April. 3. Twenty-two species of Orthoptera were caught and seven analysed. Kruskal-Wallis ranking tests showed that the largest catches of a species of cricket were obtained when the dominant wind direction was from the SE, whereas the largest catches of three acridid species were obtained when the wind was from the NW. Catch variability of two acridids could be explained by temperature (Generalised linear models); the smallest acridid by wind speed and of the cricket and two acridids by moon surface illumination ( K). 4. Eighty-two species of macrolepidoptera were identified and 17 analysed. The largest catches of a noctuid were obtained when the wind was from the SW; an oenosandrid was only caught when the wind was from the SE or NE. Catch variability of two noctuids, an arctiid and an oenosandrid could be explained by temperature; three noctuids, an arctiid, a cossid and a psychid by relative humidity; a noctuid by wind speed; and two noctuids and two oenosandrids by K. 5. To facilitate comparisons of catches and interpret long-term population trends, catch variability should be standardised for meteorological/lunar conditions. [ABSTRACT FROM AUTHOR]

Abstract: Ambient wind plays important roles in the thermo-flow performances of air-cooled condensers, but the wind effect mainly imposes on the upwind and bilateral condenser cells and will decay immediately. It is of benefit to the design and operation optimization of air-cooled condensers in a power plant to investigate the wind effect and its decay characteristics. On the basis of a representative 2 × 600 MW direct dry cooling power plant, the physical and mathematical models of the air-side fluid and heat flows for the air-cooled condensers at various ambient wind speeds and directions are set up. The velocity and temperature fields are presented and the volumetric flow rate, inlet air temperature and heat rejection for different condenser cells are obtained by using CFD simulation. The results show that the reversed flows happened in the upwind condenser cells lead to the high inlet air temperature, worsening the cooling capability of air at high wind speeds. Due to the combined behavior of hot plume discharge and ambient wind, the wind effect decays rapidly along the wind direction. At the wind direction of 90°, the deficiencies of the thermo-flow performances of air-cooled condensers are mainly resulted from the flow rate decrease of the upwind condenser cells, not the hot plume recirculation. The hot plume recirculation flows play adverse roles in deteriorating the performances of air-cooled condensers at the wind direction of 0°. [Copyright &y& Elsevier]

Abstract: In this paper we introduce the method of measurement of wind speed and direction based on an embedded system with multiple ultrasonic sensor. The system includes front-end circuits and back-end circuits. The Front-end circuits include the sensor''s low-voltage drive circuit, preamplifier circuit, filter circuit, the voltage comparator circuit and the signal isolation circuit. Back-end circuits include the signal generator circuit, the signal detection circuit, FIFO circuit, LCD driver circuit and UART protocol Circuit. Using low voltage drive drives the sensor can reduce the debugging of the system. The system can launch and receive ultrasonic signal, and get the time of flight of ultrasonic signal according to design precision after verification. All control and processing are in Field Programmable Gate Array (FPGA). FPGA is the very key factor in system design. [Copyright &y& Elsevier]