EFFECT OF AIRFLOW RATE, LEACHING, AND PRESUBMERGENCE ON AMMONIA VOLATILIZATION AND APPARENT DENITRIFICATION LOSS OF NITROGEN FROM A SUBMERGED SOIL1

Soil Science ◽  
1989 ◽  
Vol 147 (2) ◽  
pp. 116-125 ◽  
Author(s):  
J. C. KATYAL ◽  
M. F. CARTER
2020 ◽  
Vol 38 (9A) ◽  
pp. 1257-1275
Author(s):  
Wisam M. Mareed ◽  
Hasanen M. Hussen

 Elevated CO2 rates in a building affect the health of the occupant. This paper deals with an experimental and numerical analysis conducted in a full-scale test room located in the Department of Mechanical Engineering at the University of Technology. The experiments and CFD were conducted for analyzing ventilation performance. It is a study on the effect of the discharge airflow rate of the ceiling type air-conditioner on ventilation performance in the lecture room with the mixing ventilation. Most obtained findings show that database and questionnaires analyzed prefer heights between 0.2 m to 1.2 m in the middle of an occupied zone and breathing zone height of between 0.75 m to 1.8 given in the literature surveyed. It is noticed the mismatch of internal conditions with thermal comfort, and indoor air quality recommended by [ASHRAE Standard 62, ANSI / ASHRAE Standard 55-2010]. CFD simulations have been carried to provide insights on the indoor air quality and comfort conditions throughout the classroom. Particle concentrations, thermal conditions, and modified ventilation system solutions are reported.


2013 ◽  
Vol 12 (1) ◽  
pp. CM-2013-0117-01-RS
Author(s):  
William Hunter Frame ◽  
Marcus M. Alley ◽  
Wade Thomason ◽  
Garnett Whitehurst ◽  
Brooks Whitehurst ◽  
...  

2021 ◽  
Vol 13 (4) ◽  
pp. 2027
Author(s):  
Md. Emdadul Hoque ◽  
Fazlur Rashid ◽  
Muhammad Aziz

Synthetic gas generated from the gasification of biomass feedstocks is one of the clean and sustainable energy sources. In this work, a fixed-bed downdraft gasifier was used to perform the gasification on a lab-scale of rice husk, sawdust, and coconut shell. The aim of this work is to find and compare the synthetic gas generation characteristics and prospects of sawdust and coconut shell with rice husk. A temperature range of 650–900 °C was used to conduct gasification of these three biomass feedstocks. The feed rate of rice husk, sawdust, and coconut shell was 3–5 kg/h, while the airflow rate was 2–3 m3/h. Experimental results show that the highest generated quantity of methane (vol.%) in synthetic gas was achieved by using coconut shell than sawdust and rice husk. It also shows that hydrogen production was higher in the gasification of coconut shell than sawdust and rice husk. In addition, emission generations in coconut shell gasification are lower than rice husk although emissions of rice husk gasification are even lower than fossil fuel. Rice husk, sawdust, and coconut shell are cost-effective biomass sources in Bangladesh. Therefore, the outcomes of this paper can be used to provide clean and economic energy sources for the near future.


2021 ◽  
Vol 769 ◽  
pp. 144712
Author(s):  
Obemah David Nartey ◽  
Deyan Liu ◽  
Jean Yves Uwamungu ◽  
Jiafa Luo ◽  
Stuart Lindsey ◽  
...  

Pedosphere ◽  
2021 ◽  
Vol 31 (2) ◽  
pp. 255-264
Author(s):  
Márcio R. MARTINS ◽  
Leonardo F. SARKIS ◽  
Roni F. GUARESCHI ◽  
Camila A. SANTOS ◽  
Selenobaldo A.C. SANT'ANNA ◽  
...  

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 360
Author(s):  
José L. S. Pereira ◽  
Adelaide Perdigão ◽  
Francisco Marques ◽  
Catarina Coelho ◽  
Mariana Mota ◽  
...  

Biofilters are an effective air pollution control technology to break down gaseous contaminants and produce innocuous end products. This laboratory study aimed to evaluate a biofilter media, mainly composed by tomato waste, as packing material to reduce NH3, N2O, CO2 and CH4 losses from stored pig slurry. Three mixtures of packing materials, with and without oxalic acid, were arranged in treatments, namely: mixture of tomato waste, pine bark and agricultural compost; mixture of tomato waste and rice husk; tomato waste only. A control treatment (no biofilter) was also included. The experiments were conducted using a system of laboratory scale biofilters connected to jars filled with pig slurry and under a constant airflow rate. The gas concentrations were measured for 14 days and the physicochemical of the packing materials were assessed. Results showed that biofilter media mixtures had a potential for NH3 retention ranging from 51 to 77% and the addition of oxalic acid to these biofilters increased NH3 retention to 72–79%. Additionally, the biofilter media mixtures with and without oxalic acid showed a potential retention for CH4 (29–69%) but not for N2O, yet with no impact on the global warming potential. It can be concluded that tomato based biofilters had the potential to reduce gaseous emissions from slurry.


2021 ◽  
Vol 275 ◽  
pp. 116640
Author(s):  
Haijun Sun ◽  
Yu Zhang ◽  
Yiting Yang ◽  
Yudong Chen ◽  
Paramsothy Jeyakumar ◽  
...  

2005 ◽  
Vol 59 (6) ◽  
pp. 724-731 ◽  
Author(s):  
R. N. Phalen ◽  
Shane S. Que Hee

This study developed a method to produce uniform captan surface films on a disposable nitrile glove for quantitation with a portable attenuated total reflection Fourier transform infrared (ATR-FTIR) spectrometer. A permeation test was performed using aqueous captan formulation. Uniform captan surface films were produced using solvent casting with 2-propanol and a 25 mm filter holder connected to a vacuum manifold to control solvent evaporation. The coefficient of variation of the reflectance at 1735 ± 5 cm−1 was minimized by selection of the optimum solvent volume, airflow rate, and evaporation time. At room temperature, the lower to upper quantifiable limits were 0.31–20.7 μg/cm2 ( r = 0.9967; p ≤ 0.05) for the outer glove surface and 0.55–17.5 μg/cm2 ( r = 0.9409; p ≤ 0.05) for the inner surface. Relative humidity and temperature did not affect the uncoated gloves at the wavelength of captan analysis. Glove screening using ATR-FTIR was necessary as a control for between-glove variation. Captan permeation, after 8 hours exposure to an aqueous concentration of 217 mg/mL of Captan 50-WP, was detected at 0.8 ± 0.3 μg/cm2 on the inner glove surface. ATR-FTIR can detect captan permeation and can determine the protectiveness of this glove in the field.


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