The control section

2006 ◽  
pp. 4-10
Keyword(s):  
Control Section

Determination of Soil Moisture Control Section Using Undisturbed Cores

Soil Horizons ◽  
1988 ◽  
Vol 29 (1) ◽  
pp. 1
Author(s):  
Ken Scheffe
Keyword(s):  
Soil Moisture ◽  
Moisture Control ◽  
Control Section

Omissions, Agency, and Control

2017 ◽  
Author(s):  
Michael J. Zimmerman
Keyword(s):  
Subjunctive Conditionals ◽  
Control Section ◽  
And Control

This chapter focuses on two questions: How is omission related to action? Are our omissions within our control? Section 5.1 examines the question whether the control that we have over our actions and their consequences may be understood partly in terms of subjunctive conditionals. Section 5.2 examines the question whether the control that we have over our omissions and their consequences may be understood in the same way as the control that we have over our actions and their consequences is to be understood. Section 5.3 discusses the moral and legal significance of the conclusions reached in the preceding sections.

scholarly journals Semi-Transparent Organic Photovoltaics Applied as Greenhouse Shade for Spring and Summer Tomato Production in Arid Climate

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1152
Author(s):  
Rebekah Waller ◽  
Murat Kacira ◽  
Esther Magadley ◽  
Meir Teitel ◽  
Ibrahim Yehia
Keyword(s):  
Solar Radiation ◽  
Organic Photovoltaics ◽  
Crop Production ◽  
Production Systems ◽  
High Light ◽  
Growth And Yield ◽  
Control Group ◽  
Tomato Crop ◽  
Tomato Production ◽  
Control Section

Recognizing the growing interest in the application of organic photovoltaics (OPVs) with greenhouse crop production systems, in this study we used flexible, roll-to-roll printed, semi-transparent OPV arrays as a roof shade for a greenhouse hydroponic tomato production system during a spring and summer production season in the arid southwestern U.S. The wavelength-selective OPV arrays were installed in a contiguous area on a section of the greenhouse roof, decreasing the transmittance of all solar radiation wavelengths and photosynthetically active radiation (PAR) wavelengths (400–700 nm) to the OPV-shaded area by approximately 40% and 37%, respectively. Microclimate conditions and tomato crop growth and yield parameters were measured in both the OPV-shaded (‘OPV’) and non-OPV-shaded (‘Control’) sections of the greenhouse. The OPV shade stabilized the canopy temperature during midday periods with the highest solar radiation intensities, performing the function of a conventional shading method. Although delayed fruit development and ripening in the OPV section resulted in lower total yields compared to the Control section (24.6 kg m−2 and 27.7 kg m−2, respectively), after the fourth (of 10 total) harvests, the average weekly yield, fruit number, and fruit mass were not significantly different between the treatment (OPV-shaded) and control group. Light use efficiency (LUE), defined as the ratio of total fruit yield to accumulated PAR received by the plant canopy, was nearly twice as high as the Control section, with 21.4 g of fruit per mole of PAR for plants in the OPV-covered section compared to 10.1 g in the Control section. Overall, this study demonstrated that the use of semi-transparent OPVs as a seasonal shade element for greenhouse production in a high-light region is feasible. However, a higher transmission of PAR and greater OPV device efficiency and durability could make OPV shades more economically viable, providing a desirable solution for co-located greenhouse crop production and renewable energy generation in hot and high-light intensity regions.

Mechanism Analysis and Experimental Research on the Interception of Nitrogen and Phosphorus Pollutants by Gullies in Northern China

2011 ◽  
Vol 250-253 ◽  
pp. 3392-3396
Author(s):  
Yu Jia Song ◽  
Hui Qing Liu
Keyword(s):  
Total Phosphorus ◽  
Nitrate Nitrogen ◽  
Northern China ◽  
Careful Analysis ◽  
Ammonia Nitrogen ◽  
Mechanism Analysis ◽  
Nitrogen And Phosphorus ◽  
Urban Sewage ◽  
Control Section ◽  
Nitrogen Pollutants

The discharge of urban sewage and agricultural non-point source pollutants is the main reason causing eutrophication in gullies in most cities of northern China. Based on a careful analysis on the ecological structure and ecological characteristics of a gully, this article preliminarily studies the interception and degradation mechanisms of nitrogen pollutants by the gully. Meanwhile, to take gullies in Changchun as the object of the study, this article carries out an experiment on the interception effect of nitrogen pollutants by gullies. This experiment respectively establishes a control section in the upper and lower reaches of a gully, and takes water samples four times in each section from May to August to determine total nitrogen, total phosphorus, nitrate nitrogen, ammonia nitrogen and salinity. The result shows: the gully plays some role in the interception of pollutants; total phosphorus accounts for the largest interception in pollutants in the experimented gully section, with the relative interception rate of 27.46%, followed by ammonia nitrogen, with the interception rate of 21.80%, which is the result of the combined effects of aquatic plants, microorganisms and sediment in the gully.

Minimum threshold value of smectite for vertic properties

Soil Research ◽  
2000 ◽  
Vol 38 (1) ◽  
pp. 189 ◽  
Author(s):  
S. K. Shirsath ◽  
T. Bhattacharyya ◽  
D. K. Pal
Keyword(s):  
Significant Positive Correlation ◽  
Threshold Value ◽  
Soil Taxonomy ◽  
Minimum Threshold ◽  
Positive Correlation ◽  
Red Soils ◽  
Control Section

From a significant positive correlation between linear extensibility (LE) and the smectite content in the soil control section (SCS) of 8 soils (2 red soils, Alfisols, and 6 black soils, Vertisols, and their intergrades), the present study indicates an excellent compatibility between the marked shrink–swell characteristics and the smectitic mineralogy. The initiation of vertic properties at LE of 6 in shrink–swell soils corresponded to a minimum threshold value of 20% smectite. In order to highlight the inherent relationship between vertic properties and the swelling minerals, the mineralogy class for shrink–swell soils in US Soil Taxonomy should be only smectitic.

Discussion of “Streeter on Open-Channel Control Section”

1940 ◽  
Vol 105 (1) ◽  
pp. 752-763
Author(s):  
V. L. Streeter ◽  
Emery H. Willes ◽  
Robert O. Thomas ◽  
Frank S. Bailey ◽  
George E. Barnes
Keyword(s):  
Open Channel ◽  
Control Section ◽  
Channel Control
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