22 research outputs found
Influence of Soil Layers on the Infiltration Rates and Cumulative Infiltration Using Modified Green Ampt Model in the HYDROL-INF Simulation Environment
No full textSoil profiles are generally heterogeneous and consist of various horizontal layers due to geological processes, the formation of crusts, or other artificial or man-made activities. To quantify infiltration into these heterogeneous soil profiles, the Modified Green-Ampt Model (MGAM) is a physically-based hydrologic model that can efficiently perform under both steady and unsteady rainfall events. Based on the secondary data, this study sought to determine the effect of changing soil layers (soil textures) on infiltration rates and cumulative infiltrations in in both laboratory and field settings. Different scenarios were analyzed by rearranging soil layers and evaluating their impacts on corresponding infiltration rates and cumulative infiltrations. Simulations were run with HYDROL-INF software environment using MGAM. Three scenarios were considered for a laboratory experiment with two different types of soil texture coupled with five different soil profiles. Similarly, four scenarios were considered for the field experiments with five different types of soil texture couple with eight different soil profiles. The simulated infiltration rates and cumulative infiltrations were found to vary with soil layer change scenarios. The simulated cumulative infiltrations, ponding times, infiltrating rates at ponding, and total depth of wetting front at ponding of a five-layered laboratory soil column were identical for the three scenarios. Simulated cumulative infiltrations were 33.16, 23.65, 21.29, and 42.77 cm, respectively, for scenarios (combinations) 1, 2, 3, and 4 in the eight-layered soil profile in the field scenarios. Infiltration rates among scenarios at ponding were identical (0.46 to 0.53 cm/h) with field scenario data
Evaluation of microbial fuel cell (MFC) for bioelectricity generation and pollutants removal from sugar beet processing wastewater (SBPW)
No full textAbstractBioelectricity generation from biodegradable compounds using microbial fuel cells (MFCs) offers an opportunity for simultaneous wastewater treatment. This study evaluated the synergy of electricity generation by the MFC while reducing pollutants from sugar beet processing wastewater (SBPW). A simple dual-chamber MFC was constructed with inexpensive materials without using catalysts. Raw SBPW was diluted to several concentrations (chemical oxygen demand (COD) of 505 to 5,750 mg L−1) and fed as batch-mode into the MFC without further modification. A power density of 14.9 mW m−2 as power output was observed at a COD concentration of 2,565 mg L−1. Coulombic efficiency varied from 6.21% to 0.73%, indicating diffusion of oxygen through the cation exchange membrane and other methanogenesis and fermentation processes occurring in the anode chamber. In this study, &gt;97% of the COD and up to 100% of the total suspended solids removals were observed from MFC-treated SBPW. Scanning electron microscopy of anode indicated that a diverse community of microbial consortia was active for electricity generation and wastewater treatment. This study demonstrated that SBPW can be used as a substrate in the MFC to generate electricity as well as to treat for pollutant removal.</jats:p
Urbanization and Its Potential Impact on the Peak Discharge from the Watershed of the Upper Merced River in California
No full textUrbanization is an unavoidable process that influences many components of a watershed, and thus hydrologic processes are severely affected by changes in land use due to this urbanization. During this study, the objective was to assess the impact of urbanization on the peak discharge of a watershed in accordance with the outcome of this research. For this purpose, Watershed Modeling System (WMS) software and Hydrologic Engineering Center- Hydrologic Modeling System (HEC-HMS) model were used for simulating various land-use scenarios of Merced County, in the central part of California, USA. Simulation results were analyzed to assess the impact of land-use changes on the peak discharge of the watershed. The results showed that approximately 18% peak discharge was increased at the sub-basin level and approximately 2% peak discharge was increased at the final outlet. In the future, the study could help researchers, policymakers, and structural designers to foresee and prevent the unpleasant effects of urbanization so that they can take specific measures to prevent calamities beforehand. Keywords: Watershed-modeling, urbanization, land use, peak discharge, WMS, HEC-HMS. DOI: 10.7176/CER/14-7-02 Publication date: November 30th 202
Evaluation of Using an Infrared Temperature Sensor for Plant Surface Temperature Based Greenhouse Climate Control
No full textInfluence of Soil Layers on the Infiltration Rates and Cumulative Infiltration Using Modified Green Ampt Model in the HYDROL-INF Simulation Environment
No full textSoil profiles are generally heterogeneous and consist of various horizontal layers due to geological processes, the formation of crusts, or other artificial or man-made activities. To quantify infiltration into these heterogeneous soil profiles, the Modified Green-Ampt Model (MGAM) is a physically-based hydrologic model that can efficiently perform under both steady and unsteady rainfall events. Based on the secondary data, this study sought to determine the effect of changing soil layers (soil textures) on infiltration rates and cumulative infiltrations in in both laboratory and field settings. Different scenarios were analyzed by rearranging soil layers and evaluating their impacts on corresponding infiltration rates and cumulative infiltrations. Simulations were run with HYDROL-INF software environment using MGAM. Three scenarios were considered for a laboratory experiment with two different types of soil texture coupled with five different soil profiles. Similarly, four scenarios were considered for the field experiments with five different types of soil texture couple with eight different soil profiles. The simulated infiltration rates and cumulative infiltrations were found to vary with soil layer change scenarios. The simulated cumulative infiltrations, ponding times, infiltrating rates at ponding, and total depth of wetting front at ponding of a five-layered laboratory soil column were identical for the three scenarios. Simulated cumulative infiltrations were 33.16, 23.65, 21.29, and 42.77 cm, respectively, for scenarios (combinations) 1, 2, 3, and 4 in the eight-layered soil profile in the field scenarios. Infiltration rates among scenarios at ponding were identical (0.46 to 0.53 cm/h) with field scenario data
Effects of low Pre-Night Temperature on Microclimate, Fruit Yield, and Energy Consumption of Greenhouse Tomatoes Grown with a Raised-Trough Production System
No full text
The effect of feeding high fat diet to beef cattle on manure composition and gaseous emission from a feedlot pen surface
No full textAbstract Background Dietary manipulation is a common practice to mitigate gaseous emission from livestock production facilities, and the variation of fat level in the diet has shown great influence on ruminal volatile fatty acids (VFA) and enteric methane generation. The changes in dietary fat levels influence rumen chemistry that could modify manure nutrient composition along with odor and gaseous emissions from manure management facilities. Methods A field experiment was carried out on beef cattle feedlots to investigate the effect of four levels of dietary fat concentrations (3 to 5.5 %) on the manure composition and gaseous emissions (methane-CH4, nitrous oxide-N2O, carbon dioxide-CO2 and hydrogen sulfide-H2S) from the feedlot pen surface. The experiment was carried out over a 5-month period from June to October during North Dakota’s summer-fall climatic condition. Air and manure sampling was conducted five times at a 20–30 day intervals. Results Overall, this research indicated that fat levels in diet have no or little effect on the nutrient composition of manure and gaseous emission from the pens with cattle fed with different diet. Though significant variation of gaseous emission and manure composition were observed between different sampling periods, no effect of high fat diet was observed on manure composition and gaseous emission. Conclusions It can be concluded that addition of fat to animal diet may not have any impact on gaseous emission and manure compositions
