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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 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]

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]

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]

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.

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]

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]

Abstract: Wind-break wall is considered to be an effective way to weaken the inlet flow distortions and hot plume recirculation of air-cooled condensers in a power plant. It is of use to investigate the effects of wind-break wall configurations on the thermo-flow performances of air-cooled condensers. The physical and mathematical models of the air-side fluid and heat flows for the air-cooled condensers in a representative 2 × 600 MW direct dry cooling power plant are established with three different configurations of the wind-break wall. The volumetric flow rate and heat rejection of the air-cooled condensers are calculated and compared on the basis of the simulation results of air velocity and temperature fields at various ambient wind speeds and directions. The results show that the thermo-flow performances of the air-cooled condensers are improved by the extensions of the inner and outer walkways and elevation of the wind-break wall, especially at the wind directions ranging between 0° and 90°. The improvement thanks to the width increase of the inner or outer walkway is superior to that resulting from the elevated wind-break wall. [Copyright &y& Elsevier]

The aerodynamic behavior of tens of axial flow fans incorporated with air-cooled condensers in a power plant is different from that of an individual fan. Investigation of the aerodynamic characteristics of axial flow fan array benefits its design optimization and running regulation. Based on a representative 2×600 MW direct-dry cooling power plant, the flow rate of each fan and the overall flow rate of the fan array are obtained in the absence of ambient wind and at various wind speeds and directions, using CFD simulation. The cluster factor of each fan and the average cluster factor of the fan array are calculated and analyzed. Results show that the cluster factors are different from each other and that the cluster effect with ambient wind is significantly different from the cluster effect with no wind. The fan at the periphery of the array or upwind of the ambient wind generally has a small cluster factor. The average cluster factor of the array decreases with the increasing wind speeds and also varies widely with wind direction. The cluster effect of the axial flow fan array can be applied to optimize the design and operation of air-cooled condensers in a power plant. [ABSTRACT FROM AUTHOR]

Abstract: Ambient winds may lead to poor fan performance, exhaust air recirculation and mal-distribution of the air across the tube bundles of the air-cooled condensers in a power plant. Investigations of the impacts of the ambient winds on the air-cooled condensers are key area of focus. Based on a representative 2×600MW direct dry cooling power plant, the physical and mathematical models of the air-side fluid and heat flow in the air-cooled condensers at various ambient wind speeds and directions are set up by introducing the radiator model to the fin-tube bundles. The volumetric flow rate, inlet air temperature and heat rejection for different air-cooled condensers as a whole, condenser cells and fin-tube bundles are obtained by using CFD simulation. The results show that the thermo-flow performances for the air-cooled condenser as a whole, condenser cells and heat exchanger bundles vary widely in space. The thermal performances of the air-cooled condensers, condenser cells and fin-tube bundles at the downstream are generally superior to those at the upwind. It is of use for the upwind fan regulations and the A-frame condenser cell geometric optimization to investigate the space characteristics of the thermal performance for the air-cooled condensers in a power plant. [Copyright &y& Elsevier]

The natural wind plays disadvantageous roles in the operation of air-cooled steam condensers in power plant. It is of use to take various measures against the adverse effect of wind for the performance improvement of air-cooled condensers. Based on representative 2×600 MW direct air-cooled power plant, three ways that can arrange and optimize the flow field of cooling air thus enhance the heat transfer of air-cooled condensers were proposed. The physical and mathematical models of air-cooled condensers with various flow leading measures were presented and the flow and temperature fields of cooling air were obtained by CFD simulation. The back pressures of turbine were calculated for different measures on the basis of the heat transfer model of air-cooled condensers. The results show that the performance of air-cooled condensers is improved thus the back pressure of turbine is lowered to some extent by taking measures against the adverse impact of natural wind. [ABSTRACT FROM AUTHOR]

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The Athabasca Oil Sands Area (AOSA) in Alberta, Canada, is considered to have a high density of weather stations. Therefore, our objective was to determine an optimal network for the wind data measurement that could sufficiently represent the wind variability in the area. We used available historical data records of the weather stations in the three networks in AOSA, i.e., oil sands monitoring (OSM) water quantity program (WQP) and Wood Buffalo Environmental Association (WBEA) edge sites (ES) and meteorological towers (MT) of the air program. Both graphical and quantitative methods were implemented to find the correlations and similarities in the measurements between weather stations in each network. The graphical method (wind rose diagram) was found as a functional tool to understand the patterns of wind directions, but it was not appropriate to quantify and compare between wind speed data of weather stations. Therefore, we applied the quantitative method of the Pearson correlation coefficient (r) and absolute average error (AAE) in finding a relationship between the wind data of station pairs and the percentage of similarity (PS) method in quantifying the closeness/similarity. In the correlation analyses, we found weak to strong correlations in the wind data of OSM WQP (r = 0.04–0.69) and WBEA ES (r = 0.32–0.77), and a strong correlation (r = 0.33–0.86) in most of the station pairs of the WBEA MT network. In the case of AAE, we did not find any acceptable value within the standard operating procedure (SOP) threshold when logically combining the values of the u and v components together. In the similarity analysis, minor similarities were identified between the stations in the three networks. Hence, we presumed that all weather stations would be required to measure wind data in the AOSA. [ABSTRACT FROM AUTHOR]

Real-time monitoring of the wind vector, including wind speed and direction, is significant for crop management and production in agricultural environment. However, traditional wind vector sensors are difficult to meet the needs of modern sustainable agriculture due to their considerable size, low accuracy, and lack of energy supply. Hence, there is a great need for wind vector sensors that can respond super-sensitively to environmental stimuli without external power supply. Herein, a transparent and degradable hydroxyethyl cellulose film was introduced to fabricate a triboelectric nanogenerator (TENG) based on the slit effect for wind energy harvesting and self-powered wind vector monitoring. The maximum output voltage of slit-effect-enabled TENG (SE-TENG) is up to ~ 600 V under a wind speed of 7 m/s, and various agricultural sensors can be continuously driven. Furthermore, an omnidirectional wind energy harvester (OWEH) composed of eight SE-TENGs and an electrometer data-acquisition board was assembled to monitor the wind directions and speed ranging from 0.5 to 10 m/s accurately. This work poses an effective and green method for wind vector monitoring in agricultural environment and demonstrates the potential of TENG technology in intelligent agriculture. [Display omitted] • An omnidirectional wind energy harvester (OWEH) assembled from eight slit-effect-enabled TENGs (SE-TENG) was designed. • OWEH can acquire wind vector information in any direction. • An electrometer data acquisition (DAQ) board was designed to match OWEH for wirelessly real-time transmission of data. • OWEH can also efficiently harvest wind energy in any direction to drive a variety of agricultural sensors. [ABSTRACT FROM AUTHOR]

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 FROM AUTHOR]

In this paper, a high-precision and large-range wind speed and direction measuring method is proposed, which can solve the problem that traditional Time of Flight (ToF) method and phase detection method cannot simultaneously take into account measuring accuracy and measurement range. Firstly, based on the binary amplitude modulation and cross-correlation algorithms, the coded pulses combination is designed to measure time difference that the ultrasonic wave arrives different ultrasonic receivers. Because the coded pulses combination can obtain sharper correlation peaks, a more accurate time-difference measurement result can be gained, comparing with the traditional ToF method. Then, for further improving measuring accuracy and resolution of wind speed, a high-precision ±180° digital phase detection method based on double D flip-flops is proposed. Next, by combining time-difference and phase-difference measurement results, the measuring range of wind speed is extended and measuring accuracy is improved. Finally, a wind speed and direction measuring system is set up based on the proposed method. The experimental results show that the wind speed measuring accuracy is ±2%, the resolution is 0.05 m/s and the measurement range can theoretically reach several hundred meters per second; the wind direction measuring accuracy is ±5° and the resolution is 0.5°. At the same time, the standard deviations of the experimental results which are less than 10% demonstrate the stability of the system. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]