The Black Caribs—Native Resistance to British Penetration Into the Windward Side of St. Vincent 1763–1773

In cylindrical roller bearings, the drag effect may be induced by the rolling element translating in a fluid environment of the bearing cavity. In this article, the computational fluid dynamics method and experimental tests are employed to analyse its flow characteristics and pressure distribution. The results indicate that the pressure difference between the windward side and the leeward side of the cylinder is raised in view of it blocking the flow field. Four whirl vortexes are formed in four outlets of two wedge-shaped areas between the front part of the cylindrical surface and adjacent walls for the cylinder of L/ D = 1.5 at Re = 4.5 × 103. Vortex shedding is found in the direction of cylinder axis at Re = 4.5 × 104. The relationship between drag coefficient and Reynolds number is illustrated, obviously higher than that of the two-dimensional cylinder in open space.

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2.5D Flexible Wind Sensor Using Differential Plate Capacitors

Sensors ◽

10.3390/s21093101 ◽

2021 ◽

Vol 21 (9) ◽

pp. 3101

Author(s):

Yu Wan ◽

Zhenxiang Yi

Keyword(s):

Wind Speed ◽

Wind Direction ◽

Parallel Plate ◽

Electrode Array ◽

Copper Electrode ◽

Windward Side ◽

Leeward Side ◽

Electrode Layer ◽

Young’S Moduli ◽

Speed Up

In this paper, a novel 2.5-dimensional (2.5D) flexible wind sensor is proposed based on four differential plate capacitors. This design consists of a windward pillar, two electrode layers, and a support layer, which are all made of polydimethylsiloxane (PDMS) with different Young’s moduli. A 2 mm × 2 mm copper electrode array is located on each electrode layer, forming four parallel plate capacitors as the sensitive elements. The wind in the xy-plane tilts the windward pillar, decreasing two capacitances on the windward side and increasing two capacitances on the leeward side. The wind in the z-axis depresses the windward pillar, resulting in an increase of all four capacitances. Experiments demonstrate that this sensor can measure the wind speed up to 23.9 m/s and the wind direction over the full 360° range of the xy-plane. The sensitivities of wind speed are close to 4 fF·m−1·s and 3 fF·m−1·s in the xy-plane and z-axis, respectively.

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William Apess' Manhood Native Resistance in Jacksonian America

MELUS ◽

10.1093/melus/31.1.123 ◽

2006 ◽

Vol 31 (1) ◽

pp. 123-146 ◽

Cited By ~ 2

Author(s):

L. Bayers

Keyword(s):

William Apess ◽

Native Resistance ◽

Jacksonian America

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Computational Analysis to Factor Wind into the Design of an Architectural Environment

Modelling and Simulation in Engineering ◽

10.1155/2015/234601 ◽

2015 ◽

Vol 2015 ◽

pp. 1-10 ◽

Cited By ~ 3

Author(s):

Hassam Nasarullah Chaudhry ◽

John Kaiser Calautit ◽

Ben Richard Hughes

Keyword(s):

Fluid Dynamics ◽

Power Generation ◽

Computational Fluid Dynamics ◽

Three Dimensional ◽

Numerical Data ◽

Navier Stokes ◽

Windward Side ◽

Average Value ◽

Continuity Equations ◽

Prevailing Wind Direction

The effect of wind distribution on the architectural domain of the Bahrain Trade Centre was numerically analysed using computational fluid dynamics (CFD). Using the numerical data, the power generation potential of the building-integrated wind turbines was determined in response to the prevailing wind direction. The three-dimensional Reynolds-averaged Navier-Stokes (RANS) equations along with the momentum and continuity equations were solved for obtaining the velocity and pressure field. Simulating a reference wind speed of 6 m/s, the findings from the study quantified an estimate power generation of 6.4 kW indicating a capacity factor of 2.9% for the benchmark model. At the windward side of the building, it was observed that the layers of turbulence intensified in inverse proportion to the height of the building with an average value of 0.45 J/kg. The air velocity was found to gradually increase in direct proportion to the elevation with the turbine located at higher altitude receiving maximum exposure to incoming wind. This work highlighted the potential of using advanced computational fluid dynamics in order to factor wind into the design of any architectural environment.

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Air movement and heat loss from sheep. II. Thermal insulation of fleece in wind

Proceedings of the Royal Society of London Series B Biological Sciences ◽

10.1098/rspb.1980.0091 ◽

1980 ◽

Vol 209 (1175) ◽

pp. 209-217 ◽

Cited By ~ 16

Keyword(s):

Thermal Diffusivity ◽

Heat Loss ◽

Thermal Insulation ◽

General Relation ◽

Windward Side ◽

Leeward Side ◽

Sensible Heat ◽

Bulk Resistance ◽

Air Movement ◽

Dimensionless Constant

Penetration of an animal’s coat by wind reduces its thermal insulation and increases heat loss to the environment. From studies of the sensible heat loss from a life-sized model sheep covered with fleece, the average fleece resistance r¯ f (s cm -1 ) was related to windspeed u (m s -1 ) by 1/ r¯ f ( u ) = l/ r¯ f (0) + cu , where c is a dimensionless constant. As c is expected to be inversely proportional to coat depth Î , the more general relation k¯ ( u ) = k¯ (0) + c'u was evaluated, where k¯ = Î / r¯ f is the thermal diffusivity (cm 2 s -1 ) of the fleece and c' = cÎ is another constant (cm). The orientation of the model to the wind had little effect on the bulk resistance of the fleece, but the resistance on the windward side was substantially lower than on the leeward side.

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Position of cones within cone clusters determines seed survival in black spruce during wildfire

Canadian Journal of Forest Research ◽

10.1139/cjfr-2018-0209 ◽

2019 ◽

Vol 49 (2) ◽

pp. 121-127 ◽

Cited By ~ 4

Author(s):

T.B. Splawinski ◽

D.F. Greene ◽

S.T. Michaletz ◽

S. Gauthier ◽

D. Houle ◽

...

Keyword(s):

Black Spruce ◽

Seed Viability ◽

Heat Fluxes ◽

Wake Flow ◽

Windward Side ◽

Fire Intensity ◽

Burned Area ◽

Individual Plant ◽

Buoyant Plumes ◽

Porous Bodies

It has recently become clear that the regeneration density of serotinous species within a burned area declines with local fire intensity. It is assumed that this occurs because variation in local fire intensity leads to variation in incident heat fluxes and, ultimately, seed necrosis. We argue here that this same relationship between incident heat flux and seed necrosis is important at the scale of individual plant crowns. Using Picea mariana (Mill.) B.S.P. (black spruce), we show that postfire seed viability increases with crown height, depth into the crown, and angle from wind direction (with the windward side enjoying greater viability). All three effects are what one would expect given the physics of buoyant plumes, interactions of moving fire lines with wake flow around cylinders, and heat transfer in porous bodies such as a tree crown. We conclude by discussing the broader consequences of cone cluster size and global change on regeneration in serotinous species.

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Arsenic and Heavy Metals Contamination of Soils Around Oyu Tolgoi and Tavan Tolgoi Mines, Located in The South Gobi Desert of Mongolia

International Journal of Engineering & Technology ◽

10.14419/ijet.v7i2.23.11955 ◽

2018 ◽

Vol 7 (2.23) ◽

pp. 260

Author(s):

Galbadrakh Ragchaa ◽

Temujin Enkhbat ◽

Enkhtor Lkhamsuren

Keyword(s):

Inductively Coupled Plasma ◽

Essential Elements ◽

Soil Samples ◽

Heavy Elements ◽

Open Pit ◽

Windward Side ◽

Gobi Desert ◽

Central Mongolia ◽

Inductively Coupled ◽

The Government

In this work inductively coupled plasma - mass spectrometry (ICP-MS) method was used to determine content of harmful to human health heavy elements such as As, Cd, Cr, Pb, Th, U, and other essential elements Zn, Cu, Ni in soil samples collected around fence of two largest in Asia copper (Oyu Tolgoi) and coal (Tavan Tolgoi) deposits. The analyses revealed average content of arsenic in the examined soil samples is exceeding 1.4 times the maximum permissible limit. It is consistent with many previous studies emphasizing on a high occurrence of arsenic in soils, well waters of North and Central Mongolia. But the contents of copper in soil samples collected from three leeward locations of the copper mine Oyu Tolgoi are up to 2.18 times higher than the maximum permitted content established by the government standard of Mongolia. The contents of Cd, Ni, Pb, U, and Zn in soil probes collected from leeward locations of Ukhaa Khudag open pit mine of Tavan Tolgoi coal deposit are higher than that of in probes collected from the windward side of that by factor ranging from 1.34 to 1.64. These facts indicate possible transport and spread of heavy elements by wind from these intense operating open pit mines into adjacent dry and windy deserted region of Mongolia.

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Dust-related impacts of mining operations on rangeland vegetation and soil: a case study in Yazd province, Iran

10.21203/rs.3.rs-245412/v1 ◽

2021 ◽

Author(s):

Shahab IbrahimPour ◽

Alireza KhavaninZadeh ◽

Ruhollah Taghizadeh mehrjardi ◽

Hans De Boeck ◽

Alvina Gul

Keyword(s):

Seed Germination ◽

Vegetation Cover ◽

Microbial Respiration ◽

Germination Rate ◽

Windward Side ◽

Leeward Side ◽

Mining Operations ◽

Soil Microbial ◽

Soil Microbial Respiration ◽

The Impact

Abstract Destructive mining operations are affecting large areas of natural ecosystems, especially in arid lands. The present study aims at investigating the impact of iron mine exploitation on vegetation and soil in Nodoushan (Yazd province, central Iran). Based on the dominant wind, topography, slope, vegetation and soil of the area, soil and vegetation parameters close to the mine were recorded and analyzed according to the distance from the mine. In order to obtain the vegetation cover, a transect and plot on the windward and leeward side of the mine, with 100 m intervals and three replicates at each sampling location was used, yielding 96 soil samples. The amount of dust on the vegetation, the seed weight and seed germination rate of Artemisia sp. as the dominant species within the area, and the soil microbial respiration were measured. The relationship between vegetation cover and distance from the mine was not linear, which was due to an interplay between pollution from the mine and local grazing, while other factors did increase or decrease linearly. The results showed that, as the distance from the mine increased, the weight of 1000 seeds of Artemisia sp. was significantly increased from 271 to 494 mg and seed germination rate and soil microbial respiration were significantly increased from 11.7 to 48.4 % and from 4.5 to 5.9 mg CO2 g− 1 soil day− 1 respectively, while the amount of dust significantly decreased from 43.5 to 6 mg (g plant)−1 between the distance of 100 to 600 m from the mine in the leeward direction. A similar trend was observed in the windward side, though negative effects were lower compared to the same distance along the leeward sample locations. The direct and indirect effects on plant growth and health from mining impacts generally decreased linearly with increasing distance from the mine, up to at least 600 m. Our study serves as a showcase for the potential of bio-indicators as a cost-effective method for assessing impacts of mining activities on the surrounding environment.

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Isotopic hydrograph separation in two small mountain catchments during multiple events

Cuadernos de Investigación Geográfica ◽

10.18172/cig.3344 ◽

2018 ◽

Vol 44 (2) ◽

pp. 453 ◽

Cited By ~ 1

Author(s):

L. Holko ◽

S. Bičárová ◽

J. Hlavčo ◽

M. Danko ◽

Z. Kostka

Keyword(s):

Isotopic Composition ◽

Elevation Gradient ◽

Rain Gauge ◽

Windward Side ◽

Storm Event ◽

Hydrograph Separation ◽

Tatra Mountains ◽

Isotopic Signatures ◽

Water Fractions ◽

End Members

Two-component isotopic hydrograph separation (IHS) was developed to determine the event- and pre-event components of a single storm event. Its application for several sucessive events requires repeated determination of isotopic signatures of end-members (precipitation, pre-event component) for each event. The existence of several possible alternative signatures results in differences in calculated contributions of event-/pre- event components. This article addresses the question of how big the differences could be in small mountain catchments with different methods for detemining the end member signatures. We analyzed data on isotopic composition of daily/event precipitation at different elevations in two catchments located in the highest part of the Carpathians in July 2014.The isotopic composition of streamflow sampled every 4-6 hours was analyzed as well. Elevational gradients of δ18O and δ2H in precipitation in the study period were -0.18 ‰ 100 m-1 and -1.1 ‰ 100 m-1, respectively. An elevation gradient in deuterium excess (0.29 ‰ 100 m-1) was also found. Precipitation on the windward side of the mountains was isotopically lighter than expected for a given rain gauge elevation. Five large rainfall-runoff events occurred in the study period in the meso-scale catchment of the Jalovecký creek (Western Tatra Mountains, area 22.2 km2) and in the headwater catchment of the Škaredý creek (High Tatra Mountains, area 1.4 km2). Isotopic hydrograph separation was conducted using eight options for the isotopic signatures of event and pre-event water. The isotopic signature of the event water (rainfall) was alternatively represented by data from high or low elevations. Pre-event water was represented either by the streamflow before the event or by the value taken from the statistics of the long-term data on isotopic composition of the stream. Both isotopes (18O and 2H) were used to calculate event water fractions during peak flows of individual events. Calculated peak flow event water fractions were below 0.2-0.3 for most events. However, the differences in calculated event water fractions for alternative isotopic composition of end-members were significant even if we did not take into account changes in isotopic composition during individual rainfalls. Coefficients of variation for event water fractions calculated for various options varied during individual events from 0.14 to 0.36. It is therefore perhaps better to use a range of possible values instead of a single accurate number to interpret the IHS results. Hydrograph separations based on 18O and 2H provided similar results.

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FAÇADE DESIGN EFFECT ON CROSS-VENTILATION IN TAIWANESE SCHOOL BUILDINGS

Journal of Green Building ◽

10.3992/jgb.8.2.90 ◽

2013 ◽

Vol 8 (2) ◽

pp. 90-111 ◽

Cited By ~ 2

Author(s):

W.H. Chiang ◽

H.H. Hsu ◽

J.S. Huang

Keyword(s):

Numerical Scheme ◽

Wind Profile ◽

Incident Angle ◽

Three Dimensional ◽

Windward Side ◽

School Buildings ◽

Breathing Zone ◽

Air Exchange Rate ◽

Computational Fluid Dynamics Cfd ◽

Shading Devices

This study performed a three-dimensional numerical prediction for the induced airflow patterns and mean age of air (MAGE) around and inside a naturally ventilated school building, while accounting for the wind profile effect. Various fenestrations, hallways, and shading devices on the windward side of building were analyzed to determine how they affected wind velocity, the incident angle of airflow, and MAGE distribution inside classrooms. The numerical scheme is based on a commercial computational fluid dynamics (CFD) code, PHOENICS. The incline of incoming wind was observed on higher floors that decreased the air exchange rate in the simulated room. The inclined airflow could be effectively deflected downward through the breathing zone by hallways, 1.2-m shades as overhangs, and 0.6-m louvers. Based on this research, an appropriate combination of external attachments on the windward side of building façade can be utilized to enhance ventilation in school buildings. (See Appendix 1 for nomenclature.)

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