scholarly journals Empirical Formula to Predict the NOx Emissions from Coal Power Plant using Lab-Scale and Real-Scale Operating Data

2019 ◽  
Vol 9 (14) ◽  
pp. 2914
Author(s):  
Gyeong-Min Kim ◽  
Jong-Won Jeong ◽  
Jae-Seong Jeong ◽  
Dong-Yeop Kim ◽  
Seung-Mo Kim ◽  
...  
Keyword(s):  
Fossil Fuels ◽  
Basic Material ◽  
Nox Emissions ◽  
Drop Tube ◽  
Oxides Of Nitrogen ◽  
Fixed Carbon ◽  
Factors Affecting ◽  
Fuel Ratio ◽  
Major Factors ◽  
Exponential Relation

The use of fossil fuels has drastically increased throughout the world as the demand for energy increases. Accordingly, it has become critical that we reduce the oxides of nitrogen (NOx) and oxides of sulfur pollutants. Therefore, studies related to these activities have increased. This study was aimed at helping take pre-emptive action on NOx emissions by developing a formula that would predict NOx generation using factors related to the combustion characteristics and basic material properties of coal. In this study, the experiments were conducted using a drop tube furnace, and the correlation between coal’s major characteristics and NOx generation was analyzed and measured. Our results showed that the major factors affecting NOx generation are moisture, fixed carbon, and fuel ratio. Moisture tended to decrease NOx generation by delaying the ignition of coal and fixed carbon exhibited a tendency to be directly proportional to NOx generation. The R2 value for NOx of moisture and fixed carbon were derived as 0.7659 and 0.7063, respectively. Our results also showed that the fuel ratio had an exponential relation with the conversion of fuel-N to NOx. Based on the results of our analyses, we used moisture, fixed carbon, and fuel ratio as the major factors for creating an experimental formula. Through these results, we confirmed that the prediction formula reflects the actual amount of NOx emitted from the powerplants.

scholarly journals Performance and Sensitivity analysis of Factors Affecting NOx Emissions from Hydrogen Fueled SI Engine

2016 ◽  
Vol 6 (2) ◽  
pp. 47-74
Author(s):  
Eiman Ali Eh. Sheet
Keyword(s):  
Sensitivity Analysis ◽  
Equivalence Ratio ◽  
Engine Speed ◽  
Simulation Software ◽  
Spark Ignition Engine ◽  
P Value ◽  
Nox Emissions ◽  
Oxides Of Nitrogen ◽  
Factors Affecting ◽  
Performance And Emission

An Analysis of Variance (ANOVA) sensitivity analysis using suitable MATLAB code onthe factors affecting oxides of Nitrogen (NOx) emissions of a hydrogen powered 4-stroke,water-cooled spark-ignition engine was conducted in this work. This was done usingspecialized engine performance and emission simulation software. The parameters studiedwere the engine speed, air-fuel equivalence ratio, spark plug location in addition to some othercombustion parameters like combustion duration, heat loss besides some other usefulperformance parameters. It was found that NOx formation is minimum at peripheral sparklocation, slightly lean (PHI=0.9), and less advance timing is needed. Further, based onANOVA analysis, the combination of engine speed and spark location has more significance(effect based on P-value) compared with engine speed and equivalence ratio. The combinationof engine speed and ignition timing has more significance (effect based on P-value) comparedwith engine speed and equivalence ratio. Also found that NOx emissions behavior is moreclear at lean mixture (PHI = 0.7), central spark location (XSP = 0.5) and retarded ignitiontiming (IGN near zero).

Study of effective factors in the design of zero energy buildings in arid climate (case of Isfahan City)

2018 ◽  
Vol 8 (1) ◽  
pp. 211-221
Author(s):  
Negar Aminoroayaei ◽  
Bahram Shahedi
Keyword(s):  
Fossil Fuels ◽  
Arid Climate ◽  
Zero Energy ◽  
Factors Affecting ◽  
Zero Energy Building ◽  
Cost Of Energy ◽  
Current Century ◽  
Increase Productivity ◽  
Save Energy ◽  
Zero Energy Buildings

In the current century, a suitable strategy is concerned for optimal consumption of energy, due to limited natural resources and fossil fuels for moving towards sustainable development and environmental protection. Given the rising cost of energy, environmental pollution and the end of fossil fuels, zero-energy buildings became a popular option in today's world. The purpose of this study is to investigate the factors affecting the design of zero-energy buildings, in order to reduce energy consumption and increase productivity, including plan form, climatic characteristics, materials, coverage etc. The present study collects the features of zero-energy building in Isfahan, which is based on the Emberger Climate View in the arid climate, by examining the books and related writings, field observations and using a descriptive method, in the form of qualitative studies. The results of the research showed that some actions are needed to save energy and, in general, less consumption of renewable energy by considering the climate and the use of natural conditions.

scholarly journals Relationship between Land Use Mix and Walking Choice in High-Density Cities: A Review of Walking in Seoul, South Korea

2021 ◽  
Vol 13 (2) ◽  
pp. 810
Author(s):  
Eun Yeong Seong ◽  
Nam Hwi Lee ◽  
Chang Gyu Choi
Keyword(s):  
Land Use ◽  
Neighborhood Environment ◽  
Single Family ◽  
Housing Type ◽  
General Belief ◽  
Factors Affecting ◽  
Land Use Mix ◽  
Family Housing ◽  
Mixed Land Use ◽  
Major Factors

This study confirmed the general belief of urban planners that mixed land use promotes walking in Seoul, a metropolis in East Asia, by analyzing the effect of mixed land use on the travel mode choice of housewives and unemployed people who make non-commuting trips on weekdays. Using binomial logistic regression of commuting data, it was found that the more mixed a neighborhood environment’s uses are, the more the pedestrians prefer to walk rather than drive. The nonlinear relationship between the land use mix index and the choice to walk was also confirmed. Although mixed land use in neighborhoods increased the probability of residents choosing walking over using cars, when the degree of complexity increased above a certain level, the opposite effect was observed. As the density of commercial areas increased, the probability of selecting walking increased. In addition to locational characteristics, income and housing type were also major factors affecting the choice to walk; i.e., when the residents’ neighborhood environment was controlled for higher income and living in an apartment rather than multi-family or single-family housing, they were more likely to choose driving over walking.

scholarly journals Is it possible to estimate the need for surgical management in patients with a tubo-ovarian abscess at admission? A retrospective long-term analysis

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Murat Gözüküçük ◽  
Esra Gülen Yıldız
Keyword(s):  
Surgical Treatment ◽  
Antibiotic Therapy ◽  
Treatment Failure ◽  
Medical Treatment ◽  
Length Of Hospital Stay ◽  
Treatment Modalities ◽  
Laboratory Findings ◽  
Factors Affecting ◽  
Laboratory Infection ◽  
Major Factors

Abstract Background This study aimed to determine the possible prognostic factors correlated with the treatment modalities of tubo-ovarian abscesses (TOAs) and thus to assess whether the need for surgery was predictable at the time of initial admission. Materials and methods Between January 2012 and December 2019, patients who were hospitalized with a TOA in our clinic were retrospectively recruited. The age of the patients, clinical and sonographic presentation, pelvic inflammatory risk factors, antibiotic therapy, applied surgical treatment, laboratory infection parameters, and length of hospital stay were recorded. Results The records of 115 patients hospitalized with a prediagnosis of TOA were reviewed for the current study. After hospitalization, TOA was ruled out in 19 patients, and data regarding 96 patients was included for analysis. Twenty-eight (29.2%) patients underwent surgical treatment due to failed antibiotic therapy. Sixty-eight (70.8%) were successfully treated with parenteral antibiotics. Medical treatment failure and need for surgery were more common in patients with a large abscess (volume, > 40 cm3, or diameter, > 5 cm). The group treated by surgical intervention was statistically older than the patients receiving medical treatment (p < 0.05). Conclusions Although the treatment in TOA may vary according to clinical, sonographic, and laboratory findings; age of patients, the abscess size, and volume were seen as the major factors affecting medical treatment failure. Moreover, TOA treatment should be planned on a more individual basis.

scholarly journals Progress in Research on Carbon Nanotubes Reinforced Cementitious Composites

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Qinghua Li ◽  
Jintao Liu ◽  
Shilang Xu
Keyword(s):  
Carbon Nanotubes ◽  
Large Scale ◽  
High Strength ◽  
Cementitious Composites ◽  
Scale Production ◽  
Multiwalled Carbon ◽  
Factors Affecting ◽  
Environment And Health ◽  
Research Activities ◽  
Major Factors

As one-dimensional (1D) nanofiber, carbon nanotubes (CNTs) have been widely used to improve the performance of nanocomposites due to their high strength, small dimensions, and remarkable physical properties. Progress in the field of CNTs presents a potential opportunity to enhance cementitious composites at the nanoscale. In this review, current research activities and key advances on multiwalled carbon nanotubes (MWCNTs) reinforced cementitious composites are summarized, including the effect of MWCNTs on modulus of elasticity, porosity, fracture, and mechanical and microstructure properties of cement-based composites. The issues about the improvement mechanisms, MWCNTs dispersion methods, and the major factors affecting the mechanical properties of composites are discussed. In addition, large-scale production methods of MWCNTs and the effects of CNTs on environment and health are also summarized.

Evaluation of Si Coating on Ferritic Steels by CVD-FBR Technology in Steam Oxidation

2009 ◽  
Vol 289-292 ◽  
pp. 413-420 ◽  
Author(s):  
F.J. Bolívar ◽  
L. Sánchez ◽  
M.P. Hierro ◽  
F.J. Pérez
Keyword(s):  
Power Plants ◽  
Protective Coatings ◽  
Steam Oxidation ◽  
Steam Turbines ◽  
X Ray Diffraction ◽  
Steam Power ◽  
Factors Affecting ◽  
Steam Power Plants ◽  
Temperature And Pressure ◽  
Major Factors

The development of new power generation plants firing fossil fuel is aiming at achieving higher thermal efficiencies of the energy conversion process. The major factors affecting the efficiency of the conventional steam power plants are the temperature and, to a lesser extent, the pressure of the steam entering the turbine. The increased operating temperature and pressure require new materials that have major oxidation resistance. Due to this problem, in the last years numerous studies have been conducted in order to develop new coatings to enhance the resistance of steels with chromium contents between 9 and 12% wt against steam oxidation in order to allow operation of steam turbines at 650 0C. In this study, Si protective coatings were deposited by CVD-FBR on ferritic steel P-91. These type of coatings have shown to be protective at 650 0C under steam for at least 3000 hours of laboratory steam exposure under atmospheric pressure. Morphology and composition of coatings were characterized by different techniques, such as scanning electron microscopy (SEM), electron probe microanalysis, and X-ray diffraction (XRD). The results show a substantial increase of steam oxidation protection afforded by Si coating by CVD-FBR process.

The prediction of voluntary intake of grazing dairy cows

1986 ◽  
Vol 107 (1) ◽  
pp. 43-54 ◽  
Author(s):  
Lindsey Caird ◽  
W. Holmes
Keyword(s):  
Organic Matter ◽  
Measurement Techniques ◽  
Live Weight ◽  
Simple Equation ◽  
Factors Affecting ◽  
Farm Planning ◽  
Sward Height ◽  
The Mean ◽  
Major Factors ◽  
Grazing Dairy Cows

SUMMARYInformation on the total organic matter intake, concentrates supplied (C), live weight (LW), week of lactation (WL), milk yield (MY), herbage organic matter digestibility (HOMD), herbage mass, sward height (SHT) or herbage allowance (HAL) measured individually for 357 cows at one of three sites was assembled. Observed intake was compared with intakes predicted by existing intake equations and new prediction equations based on regression models or regression and least-squares constants were developed. Major factors affecting intake were MY, LW, WL, C and HAL or SHT. Although HOMD was correlated with intake, better predictions were obtained when HOMD was omitted. There were differences between sites possibly associated with differences in measurement techniques.The predictive value of some existing equations and new equations were tested against independent sets of data. A simple equation (A) based on MY and LW (Ministry of Agriculture, Fisheries and Food, 1975) gave satisfactory average predictions but the mean square prediction error (MSPE) was high. The equations of Vadiveloo & Holmes (1979) adjusted for bias gave a relatively low MSPE. The preferred new equations for grazing cattle included MY, LW, WL, C and HAL or SHT, and their MSPE were similar to or lower than for indoor equations.The discussion indicates that a simple equation (A) would give adequate predictions for farm planning. The more detailed equations illustrate the inter-relations of animal with sward conditions and concentrate allowances. Predicted intakes may deviate from actual intakes because of short-term changes in body reserves.

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