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Metal-organic frameworks (MOFs) are providing a new class of organic desiccant materials that possess interesting physical and adsorption characteristics. In this study, MOFs of type (i) HKUST-1, (ii) CPO-27(Ni), (iii) MIL-101(Cr) and (iv) MIL-53), are studied for greenhouse desiccant air-conditioning application. Water vapor adsorption equilibrium data of the MOFs are obtained from the literature. The adsorption equilibrium models of Dubinin-Astakhov (D-A) and Guggnheim-Anderson-de Boer (GAB) are used to represent the adsorption uptake data, and thereby adsorption isotherms are developed for various temperatures. Optimized parameters of the models are provided accordingly. Among the studied MOFs, the MIL-101(Cr) shows the highest water vapor adsorption uptake of 1.45 kg/kg at a relative pressure of 0.90 and temperature of 25°C. The CPO-27(Ni) exhibits type-I adsorption isotherm according to IUPAC classification. Greenhouse airconditioning application is studied for three demand categories based on required relative humidity of 60%, 40%, and 20%. Steady-state moisture cycled by the MOF based desiccant system is estimated. It has been found that different MOF adsorbents provide optimum desiccant unit based on available regeneration temperature. Results showed that the CPO-27(Ni) is not found applicable for required RH < 20%, whereas, MIL-101(Cr) and MIL-53 are applicable for all RH ranges. [ABSTRACT FROM AUTHOR]

This study explores evaporative cooling options for greenhouse air-conditioning for the climatic conditions of Multan (Pakistan). Greenhouse requires temperature and humidity control unit to optimize the environment inside the greenhouse for plants. In this regard, three low-cost lab-scale experimental evaporative cooling (EC) systems (i.e. direct EC (DEC), indirect EC (IEC), and Maisotsenko cycle EC (MEC)) were developed. The thermodynamic performance of the developed systems was analyzed from the viewpoints of the temperature gradient, relative humidity, vapor pressure deficit, and wet bulb, and dew point effectiveness. The MEC, DEC, and IEC systems created a temperature gradient of 18- 21°C, 20-28°C, 27-31°C at ambient temperature 28- 400C for 15th May for the climatic conditions of Multan. The spatiotemporal evaluation of temperature, relative humidity, and vapor pressure deficit (VPD) revealed that plain areas of Pakistan including Punjab province received severe temperature peaks. Whereas relative humidity peaked in monsoon season across the plain areas. Whereas for VPD, plain areas of Pakistan faced severe peaks in the summer months which can be optimized using the MEC system for greenhouse air-conditioning. Thus, the results conclude the MEC system as an optimum air-conditioning option for greenhouse air-conditioning. [ABSTRACT FROM AUTHOR]

In this study water adsorption onto silica gel are experimentally measured and isotherm data successfully correlated with Guggenheim-Anderson-de Boer (GAB) model. The Silica gel/water pair is compared with four different adsorbent-refrigerant pairs from the literature (i.e. KOH activated phenol resin based activated carbon (KOH6-PR)/ethanol pair, activated carbon (Maxsorb III)/methanol pair, zeolite (AQSOA-Z02)/water pair and polymer (PS-II)/water pair. The cooling performance parameters like specific cooling energy (SCE) and coefficient of performance (COP) of ideal adsorption cooling cycle employing each pair are evaluated by using a time independent thermodynamic model. The Dühring (i.e. P-T-W) diagram containing the ideal cycle operative at evaporator and regeneration temperatures of 10 °C and 80 °C, respectively, is constructed. Also, ideal cycle performances of adsorption system are evaluated for the evaporator temperatures of 5°C and 10°C while having the regeneration temperatures range of 55°C to 80°C. It is found that among the selected adsorbents-refrigerant pairs Maxsorb III/methanol pair has the maximum SCE and COP, at 10°C evaporator temperature, of 898.19 kJ/kg and 0.807 respectively. While minimum SCE and COP is attributed to silica gel/water pair. [ABSTRACT FROM AUTHOR]

We studied the amelioration potential of jambul (Syzygium cumini) fruit extract (JE) on fluoride ion (F) mediated behavioral alterations and hepato-nephronal histopathologies in four groups (n=10 per group) of adult male mice. Two groups, control (C) and jambul (J), were fed F-free water for 15 days while the other two groups, NaF (F) and NaF + jambul (F+J), were given 50 ppm F (from NaF) in drinking water on days 1-10 and F-free water + 0.25mL JE 12-hourly on days 11-15. The daily water intake in each group was recorded for the first 10 days. All animals were subjected to performance behaviors (balance beam bar, orientation, and climbing activities) on days 11-15 (post F-exposure period) and sacrificed to recover liver and kidneys on day 16. The organs were processed for microtomy and H & E staining. The daily water intake throughout the F-exposure period (days 1-10) in C and J groups remained constant apart from minute fluctuations while a persistent gradual decline was observed in F and F+J group animals. The mean water consumption (mL/g body weight/day) was significantly lower in F (0.0878±0.00239) and F+J (0.0873±0.00238) than in C (0.1231±000.597) and J (0.1229±0.0006) groups. Although the mean time taken to complete the balance beam bar, orientation, and climbing activities decreased gradually during the period of study (days 11-15) in all 4 groups, it remained persistently higher in F and F+J groups than in C and J groups. Hepatic histopathologies observed in F group animals included cytoplasmic vacuolations and disfigured nuclei of the hepatocytes, misaligned hepatic cords, and enlarged sinusoids and central lobular veins. Reversal of these pathological signs, with hepatic tissue regeneration and rehabilitation of the hepato-lobular arrangement, was seen in F+J group. No obvious signs of pathology were seen in histological sections of kidney in F group. Micrometric data revealed significantly higher (p≤0.05) mean percent fractional weight of liver and cross-sectional area (CSA) of hepatocytes in F (6.23±0.32 g/100 g bw and 317.26±12.08 µ², respectively) than C (5.3±0.25 g/100 g bw and 270.09±9.1 µ²), J (5.15±0.19 g/100 g bw, and 247.37±7.24 µ²) and F+J (5.72±0.15 g/100 g bw, and 179.21± 5.9µ²) groups. The nephronal micrometric data for the endothelial brush border thickness of the proximal tubules and the CSAs of glomeruli and proximal tubules showed significantly lower mean values in F (4.92±0.38 µ, 1712.9±97.6 µ², and 816.8±34.88 µ², respectively) as compared to C (6.66±0.17 µ, 2265.8±110 µ², and 1283±66.12 µ²), J (6.92±0.13 µ, 1898±113.2 µ², and 1097.3±35.3 µ²) and F+J (6.91±0.16 µ, 1841.6±95.3 µ², and 1042.4±43.3 µ²) groups. Conversely the mean luminal CSA of the proximal tubules was significantly increased in F (199.6±14.06 µ²) compared to C (123.1±5.56 µ²), J (88.12±5.25 µ²), and F+J (119.1±6.94 µ²) groups. The results showed that fluoride exposure in mice leads to various hepato-renal histopathologies and alterations in performance behaviors. These toxicities were convincingly ameliorated with JE treatment. [ABSTRACT FROM AUTHOR]