Numerical simulation on effect of irrigation conditions on water temperature distribution in a paddy field

Water management methods regulate water temperature in paddy fields, which affects rice growth and the environment. To understand the effect of irrigation conditions on water temperature in a paddy field, water temperature distribution under 42 different irrigation models including the use of ICT water management, which enables remote and automatic irrigation, was simulated using a physical model of heat balance. The following results were obtained: (1) Irrigation water temperature had a more significant effect on paddy water temperature close to the inlet. As the distance from the inlet increased, the water temperature converged to an equilibrium, which was determined by meteorological conditions and changes in water depth. (2) Increasing the irrigation rate with higher irrigation water amount increased the extent and magnitude of the effects of the irrigation water temperature. (3) When total irrigation water amount was the same, increasing the irrigation rate decreased the time-averaged temperature gradient effect over time across the paddy field. (4) Irrigation during the lowest and highest paddy water temperatures effectively decreased and increased the equilibrium water temperature, respectively. The results indicate that irrigation management can be used to alter and control water temperature in paddy fields, and showed the potential of ICT water management in enhancing the effect of water management in paddy fields. Our results demonstrated that a numerical simulation using a physical model for water temperature distribution is useful for revealing effective water management techniques under various irrigation methods and meteorological conditions.

Efficacy of benzyladenine for compensating the reduction in soybean productivity under low water supply

Undoubtedly, drought is a negative consequence of climate change. Farmers have to deal with this issue and may be forced to irrigate their crops with less water than required, however reduction in productivity is anticipated. Thus, two–year field trials were conducted to assess the impact of irrigation regimes (60, 80 and 100% of crop evapotranspiration, denoted ET60, ET80, and ET100, respectively) and benzyladenine rates (0, 50, 100, 150 and 200 mg L−1, symbolized as BA0, BA50, BA100, BA150, BA200, respectively) on soybean. Findings clarified that the maximum increases in plant height and net assimilation rate were obtained with the interactions of ET100 or ET80 x BA200 or BA150 in both seasons. ET80 x BA200 (in both seasons) and ET100 x BA150 (in the first season) were as similar as ET100 x BA200 for enhancing pods number plant−1. Irrigation water use efficiency progressively increased with decreasing irrigation water amount and increasing benzyladenine rate. In conclusion, the reduction in seed yield due to lowering water supply up to 80% of crop evapotranspiration (with saving 20% of irrigation water) could be compensated using benzyladenine, 150 mg L−1, thus it should be involved in soybean irrigation programs.

Physical Characteristics and Compressive Strength of Na-Geopolymer Paste Designed by a Taguchi Method

Geopolymer paste is a revolutionary building material that the chemical activity of inorganic molecules will create. It is an alternative to traditional Portland cement and is more Eco-friendly. This analysis aimed to classify the mixtures and their process parameters suitable for the development of Geo-polymer paste with one of the ultimate compressive powers, the highest-lowest porosity, and the lowest-lowest final and initial setting time. In the experimental design of the Geo-polymer-based-metakaolin, a Taguchi methodology has been utilized. Five variables parameters were chosen that are mostly to influence the properties of the geopolymer. These are the quantity of Si, alkali, the proportion of alkali reagents, duration of blending, and water amount. These variables’ influence has been calculated at 7 and 28 days on compressive strengths, porosity, density, and setting time. The analysis indicates that the strong compressive strength (115MPa) of Geopolymer paste could be achieved with the formula (1Na2O. Al2O3. 3.8SiO2.xH2O) utilizing suitable processing conditions under which the molar ratio of alkali silicate to alkali hydroxide must be held within the range of 3.25-3.02.

An Inter-loop Approach on Hydrothermal Carbonization of Sewage Sludge for the Production of Biochar and Its Application as an Adsorbent for Lead-acid Battery Recycling

This work presents an inter-loop approach in which the hydrothermal carbonization (HTC) of sewage sludge allows the production of biochars capable of removing iron ions, which usually harm the lead-acid batteries performance, from spent sulfuric acid without any activation step. The HTC process was performed at three different water/biomass ratios under 180 ºC by 24 h, and except for water, no additional chemical input was used. The moisture content of the sludges ranged from 76 to 91 wt.%. Biochars were characterized by XRD, FTIR, SEM, TGA and N2 adsorption-desorption. Results suggest a high dependence of their textural and surface properties on the water amount inside the reactor vessel. The expressive presence of multiple mineral phases in the sewage sludge allowed the formation of a hydrophilic surface, which was fundamental for the iron ions adsorption at strong acidic conditions. Porosity was strongly influenced by the water/biomass ratio, with biochar’s surface displaying pore dimensions in nano and micro domains. Furthermore, the non-activated biochar presented an adsorption capacity up to 148 mgFe g-1, whereas the commercial activated carbon “as received” achieved 178 mgFe g-1. Results show the potential of the HTC technique for sewage sludge conversion into biochar without pre-drying, and the possibility of interconnecting two or more industrial processes in order to make them cleaner and more sustainable, matching the principles of circular economy.

Evaluation of different cooling management strategies for lactating Holstein × Gir dairy cows

Heat stress negatively impacts production, reproduction, and health of ruminants and strategies to alleviate these losses are warranted. Therefore, 4 experiments evaluated different cooling strategies on vaginal temperature (VT) of Holstein × Gir cows. Experiment 1 compared different amounts of water (2- or 4-L) over a 1-hour period from 1000 to 1100 h and 1600 to 1700 h. Experiment 2 evaluated the effects of sprinkling duration (in hours; 1- or 2-H), whereas Exp. 3 evaluated the effects of water amount (4- or 8-L) applied for 1- or 2-H. Lastly, the effects of a cooling strategy on specific hours of the day, starting at either 0700 (T-1) or 1100 h (T-2; Exp. 4), were evaluated. In all experiments, 12 Holstein × Gir cows were used in a 2 × 2 Latin Square Design containing 2 periods of 6 days each. Temperature and humidity index (THI) were recorded hourly and VT was recorded every 10-min throughout the experiments. As expected, an hour effect was observed for THI (P < 0.0001), which peaked early in the afternoon. In Exp. 1, a treatment × hour interaction was observed (P < 0.0001) for VT, as animals assigned to receive 4-L had a reduced VT at 1100, 1600, 1700, and 2300 h (P ≤ 0.03). During the cooling applications, cows receiving 4-L for 1 hour had a reduced VT from 60 to 150 minutes (P ≤ 0.04). In Exp. 2, a treatment × hour interaction was observed (P < 0.0001) for VT, as animals assigned to receive 4-L of water for 2-H had a reduced VT at 1200 h (P = 0.05). Moreover, during the cooling process, VT was reduced for 2-H cows from 140 to 170 min after the beginning of the cooling process (P ≤ 0.05). In Exp. 3, animals assigned to receive 4-L+2H had a reduced VT at 1200, 1700, 1800, and 1900 h (P < 0.001). A treatment × hour interaction was observed (P < 0.0001), as VT was reduced for 4-L+2-H cows from 130 to 180 min after the beginning of the cooling process (P ≤ 0.05). In Exp. 4, by the time when the first cooling cycle of T-1 was applied (0700 h), T-1 cows consistently had (P ≤ 0.05) a reduced VT up to the hottest hours and greatest THI of the day (1400 and 1500 h). This pattern was maintained until the end of the last cooling cycle, whereas T-2 cows had a reduced VT. In summary, 4 L of water over a 5-min cycle for a period of 2 hours twice a day maintained VT of Holstein × Gir cows at lower levels. Moreover, the hour at which the first cooling cycle starts also should be considered when evaluating the efficacy of a cooling strategy for an entire day.

Water loss in swimming pool filter backwashing processes in the Balearic Islands (Spain)

Swimming pools are a major contributor to water consumption in our community. However, the high water loss associated with filter cleaning is unknown. In this work, we investigate the current procedures for filter backwashing in public swimming pools by questionnaires to owners and managers. Then, we use the collected data to estimate their environmental and economic costs. Besides, we measure several parameters in the field during the process performed in four representative swimming pools. The investigation revealed that the water loss associated with filter cleaning in public swimming pools arises to 5.5 million m3 water per year, which represents an expense of 13.96 million €. Based on our results, the followed protocols were inappropriate in most cases, indicating that even the required water amount would be higher. The most suitable parameters for filter backwashing monitoring were combined chlorine, ammonium, turbidity and chemical oxygen demand (COD). The necessity for specific strategies and legislation for the management of these installations, the treatment of the generated wastewater, as the implementation of different technological solutions to reduce water loss are discussed.

THE EFFECT OF IRRIGATION DOSES ON THE PRODUCTIVITY OF Citrus clementina variety “Fina Berkane”, A VARIETY OF CLEMENTINE PRODUCED IN TRIFFA PLAIN, NORTH EASTERN MOROCCO

Morocco is a Mediterranean country with an economy based on exporting agricultural products mainly to Europe. However, the ongoing climate change characterized by the frequency and the intensity of drought, along with the regularity of the rainfall is undeniably affecting the productivity of major agricultural products in Morocco. Citriculture is one of the key pillars of agricultural products in Moroccan conditions and the productivity of citriculture is tightly related to water management. To reduce this dependency under climatic change, a pilot study, over three years, has been launched to assess the effect of water stress on the production of clementine (Citrus clementina 'Berkane Clementine'). This study was carried out on the clementine, variety "Fina Berkane" at the Triffa plain, Northeastern Morocco. This variety was grafted on Volkameria rootstock with a density of 3m x 6m. Experimental variety was planted during October 2012, in loam-clay soil equipped with a drip irrigation system. Four doses of water irrigation (60%, 80%, 100%, and the conventional irrigation dose⩾120%) were tested based on the real water demand of the studied plant. Throughout the three-year monitoring, the effect of used water amount on the various parameters including yield, fruit size, and fruit quality have been studied. Results of the study revealed that the treatment 100% ETc provided a high number of fruits, yield, and a good quality ratio. It was also well reported that adopting a dose of 80% ETc could save a significant amount of irrigation water (more than 40% ETc) compared to the conventional irrigation dose (⩾120% ETc) without significantly affecting either the yield or the desired caliber profile (marketable standard).

ANALYTICAL STUDY OF RATE VOLUME LIQUID WATER CONTENT IN LOW CLOUDS OVER IRAQ

Iraq suffers a severe declining catastrophic in water resources; due to disagreement Share water to the neighboring countries Turkey, Syria and Iran. As well as the water policy in Iraq is unclear, the management of Iraq water have no strategic plan to treat the severe decrease in water sources. In this study, adopted eight climatic stations, are available at Iraqi general meteorological organization. The low clouds data 24 observations per day had been taken, from 1975 to 2005. For this purpose, the researchers determined the distribution of the stations and water amount at the Iraq using (GIS) Technique. It has found the annual average liquid water content calculated from the Low cloud only is 2585742648 m3, and the annual average Rainfall from the low cloud is 2563537 m3. In addition, the net LWC is 2583179111 m3, so there are great opportunities to Enhancement rain from Low Clouds. To get the greatest benefit from the main low – level clouds in supplying liquid water for cloud seeding, must be given a serious attention to observing four clouds type (Sc5, Cb9, Sc8 and Cu2).