MICROCLIMATE CONTROL IN GREENHOUSES BASED ON PHYTOMONITORING DATA AND MOLLIER PHASE DIAGRAM

Due to the importance of generating energy sustainably, with the Sun being a large solar power plant for the Earth, we study the cross-correlations between the main meteorological variables (global solar radiation, air temperature, and relative air humidity) from a global cross-correlation perspective to efficiently capture solar energy. This is done initially between pairs of these variables, with the Detrended Cross-Correlation Coefficient, ρDCCA, and subsequently with the recently developed Multiple Detrended Cross-Correlation Coefficient, {boldsymbol{DM}}{{boldsymbol{C}}}_{{bf{x}}}^{{bf{2}}}. We use the hourly data from three meteorological stations of the Brazilian Institute of Meteorology located in the state of Bahia (Brazil). Initially, with the original data, we set up a color map for each variable to show the time dynamics. After, ρDCCA was calculated, thus obtaining a positive value between the global solar radiation and air temperature, and a negative value between the global solar radiation and air relative humidity, for all time scales. Finally, for the first time, was applied {boldsymbol{DM}}{{boldsymbol{C}}}_{{bf{x}}}^{{bf{2}}} to analyze cross-correlations between three meteorological variables at the same time. On taking the global radiation as the dependent variable, and assuming that {boldsymbol{DM}}{{boldsymbol{C}}}_{{bf{x}}}^{{bf{2}}}={bf{1}} (which varies from 0 to 1) is the ideal value for the capture of solar energy, our analysis finds some patterns (differences) involving these meteorological stations with a high intensity of annual solar radiation.

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Experimental investigation on water vapor permeability in porous dust layers on cold fin surface of heat exchanger

This study aimed to determine the most frequent occurrence times of daily extremes of air temperature and relative humidity in Santa Maria, RS, Brazil. Hourly data from 2002 to 2019 were obtained from an automatic weather station belonging to INMET. The relative frequencies of the times of occurrence of the daily minimum and maximum air temperatures were calculated for each month. The results allowed knowing the times of occurrence of the daily maximum and minimum air temperatures and relative humidity in Santa Maria, RS, Brazil. Thus, it is possible to obtain greater accuracy in the estimation of chill hours, duration of vernalization periods, and in the quantification of stresses caused by inadequate values of these variables in agriculture. The daily minimum air temperature is most frequently recorded at 7:00 a.m., varying from 6:00 a.m. to 8:00 a.m. throughout the year. The daily maximum air temperature occurs most frequently at 4:00 p.m., while in December and January, it is delayed to 5:00 p.m. The daily maximum relative air humidity occurs most frequently at 7:00 a.m., varying from 7:00 a.m. to 9:00 a.m. throughout the year. The daily minimum relative air humidity, on the other hand, occurs most frequently at 5:00 p.m., varying from 4:00 p.m. to 6:00 p.m. in the different months of the year.

"Recycling of most of the consumables in manned spacecraft becomes essential in extended missions. The most urgent task is to supply a continuous stream of breathable oxygen to the cabin to balance the consumption. This can be derived from the metabolically produced carbon dioxide. In recent years several systems have been developed for that purpose. They consist essentially of some device to remove the CO2 so as to keep its concentration in the cabin atmosphere below a prescribed level, followed by a reactor to decompose the CO2 eventually into O2 which is recycled to the cabin. One particular method has been adopted by NASA as the most practical and reliable method for missions lasting six months or more. The recovery of O2 from CO2 is achieved in three steps. First, CO2 is concentrated and mixed with H2 in an electrochemical cell (sometimes called a hydrogen depolarized cell or HDC); the mixture is then transferred to a catalytic reactor where it is converted into water and CH4, the methane is then dumped into space; and finally the water vapor is electrolysed in a special electrolysis cell (called water vapor electrolysis cell or WVE) to O2 which is recycled to the cabin and H2 which is transferred to the concentrator. Electrochemical CO2 concentration provides several advantages. The process is continuous and the equivalent weight of the system needed to maintain the atmospheric level of C02 concentration (0.25 nw Hg) is considerably lower than the adsorption systems which do the same duty. C02 compressors which are frequently needed in other systems, e.g., in the vacuum desorption from molecular sieves, are totally eliminated. In addition, the concentration of C02 protects the catalyst in the Sabatier reactor from contamination by the cabin air and supplies the CO2/H2 mixture in proper ratio to the reactor. The development of the device was undertaken in the past five years by two private contractors, Life Systems, Inc., and Hamilton Standard Division of United Technologies. The designs agree in principle but differ in detailed mechanical design and operating conditions. One of the major problems encountered in designing the C02 concentrator is the need to use a concentrated carbonate solution as a cell electrolyte. The air temperature and humidity determine the electrolyte concentration at steady-state. At a high air relative humidity the electrolyte becomes more dilute and increases in volume. This may lead to electrolyte run-off in the gas cavities and is avoided in the Hamilton Standard design by providing a reservoir to absorb the excess electrolyte at humid conditions. At a low air relative humidity the concentration of the electrolyte increases and may exceed the solubility limit. In that case precipitation would commence which may lead to the crossover of the H2 to the air stream causing a hazardous condition. This should be avoided by proper selection of the carbonate electrolyte and air humidity. K2CO3 was first used but was replaced by CS2CO3 which has a higher solubility. Still, this did not allow for cell operation at air relative humidities below about 60 percent. Below this limit the cell performance decreased because of the loss of electrolyte and precipitation of CsHC03 at the anode. It was necessary to use extensive humidity controllers at the air inlet which added to the total system weight and power requirements. Through its efforts to overcome this problem, Hamilton Standard introduced aqueous solutions of a new electrolyte, TMAC or tetramethyl ammonium carbonate, which have such low water vapor pressures that they can be used safely for air relative humidities as low as 35 percent without significant change in performance. Very recently, Hamilton Standard completed the design and fabrication of a full-scale device for use in one-man air revitalization systems and finished a 90-day test program to demonstrate the maintainability and durability of the device with a predicted life of two years (Huddleston and Aylward, 1975 a,b,c). The HDC and WVE cells are connected electrically in series so that the energy produced by the fuel cell reactions in the HDC cell is utilized in the water vapor electrolysis. The cost of air revitalization in a spacecraft is measured in millions of dollars and the final design and operation of the system should lead to the minimum cost for a certain duty. The economy of the system is based on two factors: minimum system equivalent weight and minimum power requirements. The weight appears in cost of propellant needed to accelerate the spacecraft and it includes the weight of the HDC cells, WVE cells, Sabatier reactor and other auxiliary equipment. The power requirements are functions of the current densities used and the electrical efficiency of the cells. The total system cost depends greatly on the performance of the HDC cell. For example, a low CO2 transfer efficiency would result in additional cost of the power needed to make Hg and O2 from the H2O produced in the HDC cell. A poor H2/CO2 flow to the Sabatier reactor would lead to a low conversion efficiency which requires additional amounts of the expensive catalyst and would add to the weight of the system. The decrease in cell performance if precipitation occurs would require extra cells adding to the system weight. It is clear that an optimum design of the system is unattainable without a mathematical model that describes the performance of the HDC cell under all possible conditions. Lin and Winnick (1974) developed a fundamental model of the early versions of the device which used CS2CO3 electrolyte. The model was based on the steady-state transport equations and kinetics of the reactions which take place in the cell. Since then, several changes have taken place in the Hamilton Standard design; new electrodes and matrix materials were used and a new electrolyte was employed. It was necessary to develop a new model for the units which use TMAC electrolyte. The model should be able to simulate the new test data and predict the cell performance under all practical conditions. In that way a clear basis for design evaluation can be obtained and optimization studies can be started. This work describes the development of this mathematical model. The starting point will be to review all information pertaining to the electrochemical CO2 concentration. This is followed by a brief description of the cell design, test data and their accuracy, and all useful information concerning the new electrolyte and modifications of the cell design. Chapter IV summarizes the equations which form the basis of the steady-state mathematical model. The important model parameters are then evaluated and used to predict the cell performance over a wide range of operating conditions. Conclusions and recommendations of areas of possible improvements are finally presented."--Introduction.

SUMMARYThe production of winter wheat (Triticum aestivumL.) is affected by crop population structures and field microclimates. This 3-year study assessed the effect of different precision planting patterns and irrigation conditions on relative humidity (RH), air and soil temperature within the canopy, intercepted photosynthetically active radiation (iPAR), evapotranspiration (ET), water productivity (WP) and grain yields. Field experiments were conducted from 2011 to 2014 on a two-factor split-plot design with three replicates. The experiments involved three precision planting patterns (single row, alternating single and twin rows [hereafter ‘single–twin’] and twin row) and three irrigation treatments (0 mm (I0), 90 mm (I90) and 180 mm (I180)). Planting patterns and irrigation treatments exerted a significant effect on RH, air and soil temperature, iPAR,ET,WPand grain yield. The lowest RH and iPAR levels were detected in the single row pattern. When the irrigation treatment was identical, the highest soil and air temperatures were detected in the single row pattern, followed by the single–twin row and twin row patterns. Compared with the single row, the single–twin and twin row patterns increasedETby 0·3 and 1·4,WPby 4·7 and 5·7% and yields by 6·0 and 7·9%, respectively. Compared with I0, the I90and I180irrigation treatments increasedETby 0·3 and 1·4%, andWPby 4·7 and 5·7%, respectively. The grain yields of the twin row pattern were 5·8 and 1·7% higher than those of the single row and single–twin row patterns, respectively. Compared with I0, I90increased yield by 19·3%. The twin row pattern improved crop structure and farmland microclimate by increasing RH and iPAR, and reducing soil and air temperatures, thus increasing grain yield. These results indicated that a twin row pattern effectively improved grain yield at I0. On the basis of iPAR,WPand grain yield, it was concluded that a twin row pattern combined with an I90irrigation treatment provided optimal cropping conditions for the North China plain.

Enhancing crop yield in hydroponic greenhouses: Integrating latent heat storage and forced ventilation systems for improved thermal stratification

It is well known that water vapor and carbon dioxide in the air have several infrared bands where these gases absorb and emit radiative energy. Therefore the radiative heat absorbed by room moisture may not be neglected in the prediction of room air temperature. Glicksman and Chen(1998) carried out numerical analysis and showed that the effect of radiative heat absorbed by room air moisture should be considered in the prediction of temperature distribution in large enclosed spaces. In this paper the analysis method of the radiative energy absorbed by room moisture is shown and some examples simulated by this method are presented. (1) The numerical analysis with temperature of walls as a given boundary condition was carried out. The simulated results with 25%, 50%, 75% relative humidity were compared to the case with absolutely dry air and the impact of radiative heat absorbed by room moisture on air temperature was confirmed. The effect of moisture on air temperature was remarkable especially when the temperature difference between walls was large and the volume of space was big. (2) The interactive simulation of convective and radiative heat transfer was conducted with the moisture's effect on air temperature simultaneously. The results showed that the impact of the radiative heat absorbed by room moisture appeared not only in air temperature but in the surface temperatures of walls.

Emergence from the water ofAnax juniusDrury normally occurred after sunset. The onset was affected independently by water temperature and air temperature; low water temperature and high air temperature delayed the onset of emergence. In the field, the net vrtical distance travelled above the water, before ecdysis, was positively correlated with air temperature. In the laboratory, the vertical distance travelled above the water was greatest when air and water temperatures were approximately the same. The average speed of climbing to the first resting position above the water surface was faster at high than low water temperature, but the average speed of climbing from there to the final position, where ecdysis occurred, was reduced due to the effects of air temperature and humidity. Air temperatures below 12.6 °C were found to retard ecdysis and larvae returned to the water and emerged early the following day making the final process of emergence and ecdysis diurnal instead of nocturnal. The duration of ecdysis was shorter at high than low air temperatures and only the first three stages, as arbitrarily defined, were longer at low than high relative humidity; stage 4, shortened with low relative humidity. This study shows thatA.Junius, emerging from the water is affected at first by the temperature experienced when submerged, but it becomes gradually and cumulatively affected by air temperature and humidity while climbing to the ecdysial position and moulting.

Water vapour plays a key role in the Earth's energy balance. Almost 50% of the absorbed solar radiation at the surface is used to cool the surface, through evaporation, and warm the atmosphere, through release of latent heat. Latent heat is the single largest factor in warming the atmosphere and in transporting heat from low to high latitudes. Water vapour is also the dominant greenhouse gas and contributes to a warming of the climate system by some 24°C (Kondratev 1972). However, water vapour is a passive component in the troposphere as it is uniquely determined by temperature and should therefore be seen as a part of the climate feedback system. In this short overview, we will first describe the water on planet Earth and the role of the hydrological cycle: the way water vapour is transported between oceans and continents and the return of water via rivers to the oceans. Generally water vapour is well observed and analysed; however, there are considerable obstacles to observing precipitation, in particular over the oceans. The response of the hydrological cycle to global warming is far reaching. Because different physical processes control the change in water vapour and evaporation/precipitation, this leads to a more extreme distribution of precipitation making, in general, wet areas wetter and dry areas dryer. Another consequence is a transition towards more intense precipitation. It is to be expected that the changes in the hydrological cycle as a consequence of climate warming may be more severe that the temperature changes.

Role of street trees in mitigating effects of heat and drought at highly sealed urban sites

Hospitals and healthcare facilities are the most important application areas for heating, cooling,air conditioning and ventilation systems (HVAC). In this study, the applications of HVACsystems in critical area such as intensive care room and operating room are explained for theQaladze hospital in Sulaymaniyah, Iraq. HVAC systems used in hospital have been examined,and solutions have been presented for the problems in terms of HVAC standards and energy.Indoor air temperature, indoor relative humidity, and supply air temperature measurementswere made in different parts of the hospital and analyzed according to HVAC standards. TheHVAC Standards were compared with each other. In general, it has been determined that theindoor air temperature and relative humidity are within the limits determined in the standards.Despite the changes in summer and winter seasons, the relative humidity was found to bearound 30% and room temperatures around 24ºC. It was determined that the change in indoortemperature and relative humidity depends on the density in the hospital. All components of theair handling unit and HVAC systems should be constantly checked to improve the thermalconditions and indoor air quality in the various rooms in the hospital and to keep the parametersbetween the maximum and minimum values determined in the standards.

During the total solar eclipse on March 29, 2006 [1], researchers in Kislovodsk measured variations in the flux of the total shortwave radiation, meteorological elements (wind speed and direction and relative air humidity), and turbulence parameters in the surface atmospheric layer, vertical profiles of air temperature in the layer 0‐600 m, functions of particle size distribution (0.20‐1.50 µ m), and concentrations of light ions. It was found that the decrease in the maximum air temperature caused by the eclipse reached 3.5°C in the surface atmospheric layer and approximately 2°C at an altitude of 600 m a.s.l. After the full phase of the eclipse, turbulent kinetic energy decreased by a factor of 2.5, dispersion of the vertical component of the wind speed decreased by a factor of 2.3, turbulent heat flux decreased by a factor of 3.5, and dispersion of turbulent pulsations of air temperature decreased by a factor of 10. Despite the long history of investigations of eclipses [2], the influence of the solar eclipses on processes in the boundary atmospheric layer has not yet been studied sufficiently enough [3‐5]. It is clear that a solar eclipse should lead to variations in the thermal regime of the boundary atmospheric layer, increase in the relative air humidity, and consequent increase in the size of aerosol particles. Variations in the parameters of aerosol along with other factors can change notably the electric characteristics of the surface atmosphere [6]. Decrease in the near-surface air temperature can also lead to variations in the turbulence regime. In order to study the quantitative variations in the above-mentioned parameters of the lower atmosphere during the total solar eclipse in the last decade of March in Kislovodsk (altitude ~900 m a.s.l.), the following measurements were carried out at the urban meteorological station: flux F of total shortwave radiation (CNR1 net radiometer (Kipp and Zonen, Netherlands); accuracy ± 10 W/m 2 ), meteorological parameters (accuracy of measurements: air temperature ± 0.3°C , relative humidity ± 5% , components of wind speed ± 0.15 m/s), turbulent pulsations (digitization step 0.1 s) of three components of wind speed and air temperature using a Meteo-2M acoustic meteorological station (Institute of Atmospheric Optics, Tomsk), vertical profiles of air temperature (time averaging 5 min, spatial averaging 50 m, accuracy of measurements ± 0.5°C ) in layer 0‐ 600 m (MTP-5 UHF microwave profiler of the Central Aerological Observatory [8]), concentrations of negative light ions using a SIGMA-1 counter of aeroions (accuracy of each measurement ± 30% , time constant 1.5 s, mobility of ions >0.4 cm 2 / W · s), and distribution function of the dry base of aerosol particles in the size range 0.20‐1.50 µ m (LAS-P laser spectrometer of aerosols, averaging time of differential countable concentrations of particles 15 s, and random error of measurements of countable concentrations 20%). Calibration of the laser spectrometer was carried out using nuclear filters, which allowed us to increase the accuracy of determination of the boundaries of the particle size ranges determined by the spectrometer.

To determine the effectiveness of rehabilitation on improving ecosystem functions, we examined net photosynthetic rate (P N), tree species composition, soil enzyme activities, and the microclimate (air and soil temperature, relative humidity) of an area on Mt. Makiling that has been rehabilitated and protected from fire for over 12 years. After it was last burned extensively in 1991, restoration was initiated by planting Acacia mangium and Acacia auriculiformis. We selected three areas to study in 2003. Two areas were rehabilitated with A. mangium and A. auriculiformis, and one was still dominated by Imperata cylindrica and Saccharum spontaneum. P N of A. mangium and A. auriculiformis showed significantly lower values than those of I. cylindrica and S. spontaneum. The Acacia plantations had more naturally regenerated tree species than the grassland. Additionally, more tree species appeared in the A. mangium plantation than in the A. auriculiformis plantation. Ficus spetica was present in all of the study sites. Dehydrogenase and phosphatase activities were significantly higher in soil under the Acacia plantations than under grassland. Grassland showed higher air temperature, relative humidity, and soil temperature as well as a larger variation per hour in these parameters compared to the Acacia plantations. The highest air temperature, relative humidity, and soil temperature were measured in April during the dry season. From the regression analysis, soil temperature was significantly correlated with air temperature. Hence plantations, as a rehabilitation activity for grassland, promote natural regeneration and stabilize the microclimate. This stabilization of the microclimate affects establishment and growth of naturally occurring tree species.

Relative humidity (RH) is one of the key variables for understanding the water, energy, and carbon exchange between the Earth and the atmosphere. Traditional methods for deriving RH from remotely sensed data usually require ground meteorological observations or are limited to clear-sky conditions, thereby making it a significant challenge to obtain spatially complete RH under all-sky conditions, especially over the regions with sparse meteorological instruments for observation. To this end, a new approach for deriving all-sky RH entirely based on Moderate Resolution Imaging Spectroradiometer (MODIS) data was proposed in the present study. Two key assumptions in the approach under cloudy conditions are that the actual water vapor is linearly related to the total precipitable water vapor (PWV) and that air temperature is linearly related to land surface temperature (LST). Results from a total of 30 AmeriFlux stations proved the aforementioned assumptions based on MODIS data collected over a study period of three years from 2009 to 2011. For different aridity conditions, RH retrieval revealed reasonable accuracy with a root-mean-square error (RMSE) of approximately 15.3% over an arid and semiarid region, whereas a comparable RMSE of 17.0% was obtained over a humid area. Further results also indicated that the aforementioned linear relationships were generally temporally stable, thereby indicating that the proposed method can be used to obtain all-sky RH at a regional or global scale entirely based on MOD06_L2-derived LST and MOD05_L2-derived PWV data given that the assumed linear relationships can be easily determined by historical MOD07_L2-derived atmospheric profiles.