scholarly journals Root Zone Temperatures of Viburnum odoratissimum Grown in the Multipot Box System and Conventional Systems: Measurement and Analyses of Temperature Profiles and Predicting Root Zone Temperatures

HortScience ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 808-818 ◽  
Author(s):  
Suat Irmak ◽  
D.Z. Haman ◽  
A. Irmak ◽  
J.W. Jones ◽  
B. Tonkinson ◽  
...  
Keyword(s):  
Plant Growth ◽  
Air Temperature ◽  
Root Zone ◽  
Extreme Temperature ◽  
Ambient Air ◽  
Plant Production ◽  
Test Plant ◽  
Root Zone Temperature ◽  
Ambient Air Temperature ◽  
Viburnum Odoratissimum

This research study evaluates the effectiveness of a recently introduced irrigation-plant production system, multipot box system (MPBS), for moderating root zone temperature (RZT) compared with the conventional nursery containers. The study also deals with the development, calibration, and validation of a series of models that can be used to predict maximum (max) and minimum (min) RZTs using commonly available input variables. The Viburnum odoratissimum (Ker.-gawl.) was used as the test plant. Models were calibrated in the fall growing season and validated during the summer. The RZT was used as the dependent variable while the max and min air temperatures (Tmax and Tmin) and/or incoming solar radiation (Rs) were used as independent variables. The color of the MPBS had an effect on plant growth. Plants grown in the white MPBS had higher growth indices, shoot and root dry weights, and number of stems as compared with the plants in the black MPBS or the conventional (control) system (CS). White MPBS maintained cooler RZTs than the max air temperature during both seasons. Also, white MPBS maintained cooler RZTs than the black MPBS and CS during the two seasons. In both seasons, water temperature in the black MPBS was higher than the temperature in the white MPBS contributing to the high RZTs in the black MPBS. The RZT of the black MPBS and CS exceeded the critical value (40 °C), which is cited in the literatures as negatively impacting root growth, water and nutrient uptake, leaf area, plant survival, root and shoot dry weights, water status, and photosynthesis. The RZT in the CS was above 45 °C for most of the summer season and plants were exposed to this extreme temperature for a few hours a day during most of the summer. The white MPBS provided a better environment and enhanced plant growth. For regions where ambient air temperature ranged from 2 to 41 °C, the white MPBS can provide adequate and effective RZT protection for plants grown in No. 1, 3.8-L standard black conventional containers. Predicted RZT values were well correlated with measured values in all systems. Rs did not have an effect on predicting RZTmax in the MPBS treatments. Wind speed did not contribute to predicting RZT in any production systems. The root mean square error between measured and predicted RZT was relatively low ranging from 0.9 to 2.8 °C. Models were able to explain at least 74% of the variability in RZTs using only Tmax, Tmin, and/or Rs. Models developed in this study should be applicable for estimating RZTs when similar management and cultural practices are present. Models of this study are practical, simple, and applicable to predict RZTs where ambient air temperature ranges from 1.9 to 40 °C. Model results should not be extrapolated beyond these limits.

scholarly journals Evaluation of hilling efficiency as a method of protection of vine against winter cold in Québec

OENO One ◽  
2000 ◽  
Vol 34 (3) ◽  
pp. 83
Author(s):  
Yvon Jolivet ◽  
Jean-Marie Dubois
Keyword(s):  
Cold Tolerance ◽  
Air Temperature ◽  
Root Zone ◽  
Ambient Air ◽  
Temperature Measurements ◽  
Automatic Data ◽  
Root Zone Temperature ◽  
Temperature Variations ◽  
Air Mass ◽  
The Earth

<p style="text-align: justify;">Extreme minimum temperatures during wintertime sometimes dropping to -35°C can damage the latent buds of hybrid vines whose tolerance to cold temperatures is between -20°C and -30°C and accordingly can compromise their survival. To counter these adverse effects, the majority of winegrowers in Québec cover their vine stocks with 40 to 60 cm of earth taken between the rows. Based on temperature measurements registered within the earth ridges and between the rows it is possible to describe temperature variations near the fruit buds and in the root zone of the <em>Vitis vinifera</em> L. var. Melon. Temperature measurements were carried out during the 1994- 1995 cold season in a vineyard near Sherbrooke, Québec. Five 95 cm long thermocables were installed in the ground, in a straight line and perpendicular to the hilling lines. The thermocables were connected to an automatic data acquisition system. Results show that with hilling, under at least 15 cm of earth, it is possible to conserve the latent buds of the vine at temperatures superior to their cold tolerance threshold as defined by the Leddet exotherms (- 13°C) whether or not in the presence of snow cover. In fact, the minimum temperature reached in the bud zone was never lower than -2°C even when the minimum air temperature reached -33°C. However, because of their higher elevation in relation to the ground, these ridges are more exposed on the one hand to surface climatic elements such as wind and radiation and, on the other hand, this form of micro-topography permits the dissipation of internal ground heat more rapidly than a flat surface. In the Fall, when there is still little snow accumulation on the ground, the upper portion of the ridges remains free of snow and the first centimeters of ground on the surface can present temperature variations in the order of 10°C within 24 hours, while the ground surface between the ridges remains thermally quite stable because of the presence of snow. The thawing periods of January, often accompanied by showers, also affect temperature conditions within these ridges all the way down to the root zone. For example, the January 17, 1995 rain shower (15.6 mm of rain) produced an elevation of 6°C in average temperatures in the bud zone. When the hot air mass responsible for the thawing is replaced by a cold air mass accompanied by snowfall, the earth ridge freshly covered by snow conserves temperatures above the cold tolerance threshold of the buds even if the ambient air temperature drops to -20°C (27 January 1995). Results of this research show that hilling is an efficient method for combating heavy winter colds towards protecting the latent buds of the vine but its impact on the elevation of temperatures at the roots remains minimal because it maintains the root zone temperature 1 to 2°C higher than the same zone without hilling. Given that the tolerance to cold of roots is from -8 to -10°C, this gain of a few degrees nevertheless increases the vine's chances of survival.</p>

Treatment of a Municipal Leachate Under Multi-Variable Conditions

1982 ◽  
Vol 17 (1) ◽  
pp. 135-148
Author(s):  
P.T. Wong ◽  
D.S. Mavinic
Keyword(s):  
Air Temperature ◽  
Nutrient Loading ◽  
Ambient Air ◽  
Removal Rates ◽  
Ambient Air Temperature

Abstract The treatability of a municipal leachate (BOD5 = 8090 mg/L) was investigated, by aerobic biostabilization, at a nutrient loading of BOD5:N:P of 100:3.2:1.1. The first stage effluents were subsequently polished by lime-magnesium coagulation. The ranges of ambient air temperature and sludge age studied were 5° to 25°C and 5 to 20 days, respectively. In the biostabilization phase, a BOD5:N:P loading of 100:3.2:1.1 was found to be “adequate” for treatment. Organic and metal removals in the first stage units were excellent. Under all conditions investigated, except for the two units close to washout conditions (5-day sludge age units at 5° and 10°C), BOD5 and COD removals of at least 99.4 and 96.4 percent, respectively, were achieved. Similarly, removal rates for most of the metals monitored were greater than 90 percent. In general, the removal of residual contaminants was not enhanced significantly by the addition of magnesium in the lime-magnesium polishing step.

scholarly journals Ambient Air Temperature Assisted Crystallization for Inorganic CsPbI2Br Perovskite Solar Cells

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3398
Author(s):  
Yi Long ◽  
Kun Liu ◽  
Yongli Zhang ◽  
Wenzhe Li
Keyword(s):  
Solar Cells ◽  
Air Temperature ◽  
High Performance ◽  
Defect Density ◽  
Perovskite Solar Cells ◽  
Ambient Air ◽  
Dark Phase ◽  
High Quality ◽  
Ambient Air Temperature ◽  
Air Atmosphere

Inorganic cesium lead halide perovskites, as alternative light absorbers for organic–inorganic hybrid perovskite solar cells, have attracted more and more attention due to their superb thermal stability for photovoltaic applications. However, the humid air instability of CsPbI2Br perovskite solar cells (PSCs) hinders their further development. The optoelectronic properties of CsPbI2Br films are closely related to the quality of films, so preparing high-quality perovskite films is crucial for fabricating high-performance PSCs. For the first time, we demonstrate that the regulation of ambient temperature of the dry air in the glovebox is able to control the growth of CsPbI2Br crystals and further optimize the morphology of CsPbI2Br film. Through controlling the ambient air temperature assisted crystallization, high-quality CsPbI2Br films are obtained, with advantages such as larger crystalline grains, negligible crystal boundaries, absence of pinholes, lower defect density, and faster carrier mobility. Accordingly, the PSCs based on as-prepared CsPbI2Br film achieve a power conversion efficiency of 15.5% (the maximum stabilized power output of 15.02%). Moreover, the optimized CsPbI2Br films show excellent robustness against moisture and oxygen and maintain the photovoltaic dark phase after 3 h aging in an air atmosphere at room temperature and 35% relative humidity (R.H.). In comparison, the pristine films are completely converted to the yellow phase in 1.5 h.

Evaluation of the influence of ambient air temperature and air velocity on mortar cement durability using a forced convection solar dryer

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Younes Bahammou ◽  
Mounir Kouhila ◽  
Haytem Moussaoui ◽  
Hamza Lamsyehe ◽  
Zakaria Tagnamas ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Forced Convection ◽  
Air Temperature ◽  
Building Materials ◽  
Ambient Air ◽  
Physical Significance ◽  
Drying Process ◽  
Air Velocity ◽  
Content Type ◽  
Ambient Air Temperature

PurposeThis work aims to study the hydrothermal behavior of mortar cement toward certain environmental factors (ambient air temperature and air velocity) based on its drying kinetics data. The objective is to provide a better understanding and controlling the stability of mortar structures, which integrate the sorption phenomenon, drying process, air pressure and intrinsic characteristics. This leads to predict the comportment of mortar structures in relation with main environmental factors and minimize the risk of cracking mortar structures at an early age.Design/methodology/approachThermokinetic study was carried out in natural and forced convection solar drying at three temperatures 20, 30 and 40°C and three air velocities (1, 3 and 5 m.s-1). The empirical and semiempirical models tested successfully describe the drying kinetics of mortar. These models simulate the drying process of water absorbed by capillarity, which is the most common humidity transfer mechanism in building materials and contain parameters with physical significance, which integrate the effect of several environmental factors and intrinsic characteristics of mortar structures.FindingsThe models simulate the drying process of water absorbed by capillarity, which is the most common humidity transfer mechanism in building materials and contain parameters with physical significance, which integrate the effect of several environmental factors and intrinsic characteristics of mortar structures. The average activation energy obtained expressed the temperature effect on the mortar diffusivity. The drying constant and the diffusion coefficient can be used to predict the influence of these environmental factors on the drying behavior of various building materials and therefore on their durability.Originality/valueEvaluation of the effect of several environmental factors and intrinsic characteristics of mortar structures on their durability.

scholarly journals Outdoor PM2.5, Ambient Air Temperature, and Asthma Symptoms in the Past 14 Days among Adults with Active Asthma

10.1289/ehp92 ◽  
2016 ◽  
Vol 124 (12) ◽  
pp. 1882-1890 ◽  
Author(s):  
Maria C. Mirabelli ◽  
Ambarish Vaidyanathan ◽  
W. Dana Flanders ◽  
Xiaoting Qin ◽  
Paul Garbe
Keyword(s):  
Air Temperature ◽  
Ambient Air ◽  
The Past ◽  
Asthma Symptoms ◽  
Ambient Air Temperature

EFFECTS OF LOW FLUCTUATING TEMPERATURES ON FARM ANIMALS.: III. INFLUENCE OF AMBIENT AIR TEMPERATURE ON FEED INTAKE OF LACTATING HOLSTEIN-FRIESIAN COWS

1958 ◽  
Vol 38 (2) ◽  
pp. 148-159 ◽  
Author(s):  
M. A. MacDonald ◽  
J. M. Bell
Keyword(s):  
Milk Production ◽  
Air Temperature ◽  
Low Temperatures ◽  
Ambient Air ◽  
Feed Consumption ◽  
Ambient Temperatures ◽  
Ambient Air Temperature ◽  
Holstein Friesian ◽  
Cent Level ◽  
Friesian Cows

This report presents effects of low temperatures on the feed consumption and efficiency of milk production of six mature, lactating, Holstein-Friesian cows that were confined in stanchions for three fortnightly experimental periods during which ambient temperatures measured in degree-hours per day (d-h/day) ranged from 110 to 1152 and daily minimum ambient air temperature (DMAAT) varied from 0° to 38°F. Applying results obtained, it was calculated that as temperatures decreased, i.e., d-h/day increased from 100 to 1200 and DMAAT decreased from 40° to 0°F, average daily intakes of total dry matter, hay, and gross and digestible Calories increased approximately 6.4 lb., 5.3 lb., 13 Therms and 9 Therms, respectively. Each of these increases was statistically significant at the 1 per cent level. Reductions in temperature also decreased gross and net caloric efficiencies of milk production approximately 10 and 8.5 per cent, respectively. These decreases were significant at the 2 per cent level. No correlation was evident between crude protein utilization and temperature.Results indicated that thermal stress was not overcome adequately by supplementary hay intake alone and that appetite stimulation by low temperatures had a carry-over effect continuing at least 24 hours. For continued efficient milk production during winters where low ambient temperatures are prevalent these results suggest it is necessary to provide some form of building insulation, ambient heat and/or provide a high energy supplement to otherwise adequate production rations.

scholarly journals Research On Solar Energy Collector With Cell Polycarbonate Absorber

2015 ◽  
Vol 1 ◽  
pp. 213
Author(s):  
Henriks Putāns ◽  
Viktorija Zagorska ◽  
Imants Ziemelis ◽  
Zanis Jesko
Keyword(s):  
Experimental Investigation ◽  
Solar Radiation ◽  
Air Temperature ◽  
Heat Carrier ◽  
Heat Insulation ◽  
Ambient Air ◽  
Maximum Temperature ◽  
Experimental Examination ◽  
Ambient Air Temperature ◽  
Flat Plate Solar Collector

A flat plate solar collector with cell polycarbonate absorber and transparent cover has been made and its experimental investigation carried out. The collector consists of a wooden box, into which, a layer of heat insulation with a mirror film and 4 mm thick cell polycarbonate sheet, as the absorber, are placed. The coherence between collector’s efficiency, heat carrier and ambient air temperature, as well as intensity of the solar radiation and heat power in the experimental investigation has been obtained. During the experimental examination the maximum temperature of the heat carrier reached 80˚C at the intensity of solar radiation about 0.8 kW/m2 and ambient air temperature around 32˚C. The efficiency of the collector reached 33-60%, depending on the intensity of solar radiation and surrounding air temperature.

The effect of ambient air temperature on cardiovascular and respiratory mortality in Thessaloniki, Greece

2019 ◽  
Vol 647 ◽  
pp. 1351-1358 ◽  
Author(s):  
Panayiotis Kouis ◽  
Maria Kakkoura ◽  
Konstantinos Ziogas ◽  
Anastasia Κ. Paschalidou ◽  
Stefania I. Papatheodorou
Keyword(s):  
Air Temperature ◽  
Ambient Air ◽  
Respiratory Mortality ◽  
Ambient Air Temperature
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