Nature and Distribution of Pyrite in Iowa Coal

1976 ◽  
Vol 34 ◽  
pp. 620-621
Author(s):  
Raymond T. Greer
Keyword(s):  
Air Pollution ◽  
Significant Contribution ◽  
Size Range ◽  
Sulfur Removal ◽  
Optical Microscope ◽  
Energy Requirements ◽  
Local Correlation ◽  
Iron Sulfides ◽  
Environmental Considerations ◽  
Large Reserve

Iowa has a large reserve of high-sulfur coal. In view of the projected energy requirements for the state, in-state coal resources should provide a significant contribution. Environmental considerations and air pollution regulations emphasize the desirability of sulfur removal. Both microstructural and microchemical characteristics of Iowa coal relate to the choice and improvement of processing and purification procedures, as well as provide information which may aid in local correlation of deposits.Iron sulfides occur in the coal as nodules and narrow seams (up to 150 mm thick, thinning out over a distance of hundreds of millimeters) and in finely disseminated form. Individual pyrite euhedra occur predominantly in a size range of about one to 40 micrometers in diameter, with by far most of the crystallites being one to two micrometers in diameter (Fig. 1). This raises special characterization problems for routine conventional optical microscope studies. The pyrite also occurs as spherical assemblies of crystallites. These framboidal masses (after Framboise, the French for Raspberry) range from a few micrometers to several hundred micrometers in diameter, with most of them being approximately 10 and 20 micrometers in diameter (Fig. 2).

Stabilizing pyritic material

1989 ◽  
Vol 4 ◽  
pp. 244-248 ◽  
Author(s):  
Donald L. Wolberg
Keyword(s):  
Significant Contribution ◽  
Organic Materials ◽  
Sedimentary Rocks ◽  
Iron Sulfides ◽  
Decomposition Products ◽  
Iron Minerals ◽  
Pyrite Formation ◽  
Organic Sediments ◽  
Freshwater Environments

The minerals pyrite and marcasite (broadly termed pyritic minerals) are iron sulfides that are common if not ubiquitous in sedimentary rocks, especially in association with organic materials (Berner, 1970). In most marine sedimentary associations, pyrite and marcasite are associated with organic sediments rich in dissolved sulfate and iron minerals. Because of the rapid consumption of sulfate in freshwater environments, however, pyrite formation is more restricted in nonmarine sediments (Berner, 1983). The origin of the sulfur in nonmarine environments must lie within pre-existing rocks or volcanic detritus; a relatively small, but significant contribution may derive from plant and animal decomposition products.

scholarly journals Chipping machines: disc and drum energy requirements

2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
Alessio Facello ◽  
Eugenio Cavallo ◽  
Raffaele Spinelli
Keyword(s):  
Air Pollution ◽  
Fuel Consumption ◽  
Specific Energy ◽  
Processing Time ◽  
Fossil Fuel ◽  
Energy Requirements ◽  
Power Demand ◽  
Production Chain ◽  
Testing Conditions ◽  
Processed Material

Air pollution and fossil fuel reserves exhaustion are increasing the importance of the biomass-derived products, in particular wood, as source of clean and renewable energy for the production of electricity or steam. In order to improve the global efficiency and the entire production chain, we have to evaluate the energetic aspects linked to the process of transformation, handling and transport of these materials. This paper reports results on a comparison between two chippers of similar size using different cutting technology: disc and drum tool respectively. During trials, fuel consumption, PTO torque and speed, processing time and weight of processed material were recorded. Power demand, fuel consumption, specific energy and productivity were computed. The machine was fed with four different feedstock types (chestnut logs, poplar logs, poplar branches, poplar sawmill residues). 15 repetitions for each combination of feedstock-tool were carried out. The results of this study show that the disc tool requires, depending on the processed material, from 12 to 18% less fuel per unit of material processed than the drum tool, and consequently, from 12 to 16% less specific energy. In particular, the highest difference between tools was found in branches processing whereas the smallest was in poplar logs. Furthermore the results of the investigation indicate, that, in testing conditions, the productivity of drum tool is higher (8%) than disc tool.

scholarly journals Air quality as a factor affecting urban tourism

2020 ◽  
Vol 30 (2) ◽  
pp. 109-123
Author(s):  
Aleksandra Łapko ◽  
Roma Strulak-Wójcikiewicz ◽  
Aleksander Panasiuk
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Significant Contribution ◽  
Urban Tourism ◽  
Factors Affecting ◽  
Travel Decisions ◽  
High Degree ◽  
Mass Events

The purpose of the article is to determine whether potential tourists consider information about a city’s air quality in their assessment of its tourist attractiveness and how this this information affects their travel decisions. Urban tourism is a common and dynamically developing form of tourism. Cities encourage tourists to visit them with various attractions, cultural, gastronomic and accommodation offerings as well as mass events. At the same time, they are often industrial centres and important transportation hubs, which makes them characterized by a high degree of air pollution. The article presents results of a survey involving 509 respondents from Poland. The data were used to assessment to what extent information about air quality in a given city is relevant for people planning a tourist trip. In addition, the survey provided information about factors that could increase the respondents’ interest in the level of air quality in a city they were planning to visit. Particular attention was paid to the respondents’ health. Many diseases can be the result of air pollution, or can be aggravated by substances contained in smog. Therefore, the authors tried to determine whether people suffering from such illnesses were more likely to pay special attention to air quality in their prospective destinations. The results constitute a significant contribution to the knowledge about the factors affecting demand in urban tourism. They may be relevant for entities responsible for managing cities and promoting tourism products. The article also draws attention to the fact that problems arising from air pollution in cities can affect not only their residents, but also tourists.

scholarly journals Analysis of traffic-related air pollution using Shanghai road traffic state index

2018 ◽  
Vol 189 ◽  
pp. 10003 ◽  
Author(s):  
Ruoyu Chen ◽  
Lianliang Chen ◽  
Wenhao Fan
Keyword(s):  
Air Pollution ◽  
Significant Contribution ◽  
Road Traffic ◽  
Traffic Emissions ◽  
Diurnal Variability ◽  
Traffic State ◽  
Road Traffic Emissions ◽  
State Index ◽  
Pollution Concentrations ◽  
Statistical Summary

Recently, due to the rapid economic development and the acceleration of urbanization, haze events have occurred frequently in most parts of China, which has attracted widespread attention at home and abroad. This study presents a statistical summary of air pollution concentrations and traffic state indexes from August 2014 to April 2015 in Shanghai, China. We find PM2.5 concentrations show a remarkable seasonal variability with ``winter > spring > autumn > summer'' in Shanghai. Concentrations of PM2.5, CO, NO2, SO2 are generally higher in winter than in summer due to enhanced anthropogenic and biogenic emissions and unsuitable meteorological conditions for pollution diffusion, contrary to concentrations of O3. The weekly changes of NO2 are highly consistent with that of traffic state indexes, suggesting a significant contribution to NO2 concentrations from road traffic emissions. Two moderate peaks are found in the diurnal variability of concentrations of PM2.5, CO and NO2, similar to road traffic indexes, indicating the important contribution of road traffic emissions every day. We find that SO2, NO2, CO are the dominant factors contributing to PM2.5 pollution, where NO2 and CO are mainly from road traffic emissions. The average annual Spearman correlation coefficient is r = 0.689 (p < 0.01), r = 0.564 (p < 0.01), r = 0.812 (p < 0.01), respectively.

Role of Sub-Micron Particles in Air Pollution

1972 ◽  
Vol 30 ◽  
pp. 354-355
Author(s):  
A. F. Bush ◽  
J. P. Burke ◽  
E. S. C. Bowler
Keyword(s):  
Air Pollution ◽  
Los Angeles ◽  
Size Range ◽  
Geometric Mean ◽  
Ambient Air ◽  
Research Facility ◽  
Fuel Wood ◽  
Pollution Research ◽  
Micron Size

In the decade ahead greater attention to sub-micron particulates in air pollution will most certainly occur. The importance of the electron microscope and support equipment will be invaluable. Airborne particles in the sub-micron size range, detectable only by electronmicroscopy, have been studied at the Air Pollution Research Facility at the School of Engineering and Applied Science at UCLA. Samples were taken of ambient air daily for several months in the downtown area of Los Angeles. From the study it was clear that a substantial difference in the number of sub-micron particles existed when comparing a clear day with a smoggy day. The magnitude was ten fold (0.07 billion particles/cubic foot to 0.7 billion/cubic foot). The geometric mean particle size was approximately 0.03 microns.Samples were also collected from a variety of specific sources. Most of these were associated with the combustion of fuel: coal, oil, natural gas, gasoline, diesel fuel, wood, and industrial and domestic wastes.

Effect of Titanium on Homogenizing Process and Microstructure of Alloy 2618

2014 ◽  
Vol 33 (3) ◽  
pp. 261-267 ◽  
Author(s):  
Tingting Liu ◽  
Ya Liu ◽  
Xuping Su ◽  
Haoping Peng ◽  
Jianhua Wang
Keyword(s):  
Grain Size ◽  
Size Range ◽  
Homogenization Temperature ◽  
Optical Microscope ◽  
Ti Alloy ◽  
X Ray ◽  
Before And After ◽  
Equilibrium Solidification ◽  
Ti Particles ◽  
Scanning Electron

AbstractThe effect of titanium on the homogenizing process of alloy 2618 and the microstructure of the Ti-containing alloy before and after homogenization has been investigated using optical microscope (OM), scanning electron microscope (SEM), energy dispersive X-ray (EDX), differential thermal analysis (DTA). The results show that the addition of 1.5 mass% Ti to alloy 2618 could refine its grain size remarkably. A large amount of rod-shape Al3Ti particles with the size range of 2–12 μm distribute evenly and dispersively in the alloy. It is θ (Al2Cu) phase instead of S' (Al2CuMg) obtained in eutectic structures due to the non-equilibrium solidification in casting of 2618-Ti alloy, which is the same as alloy 2618. The optimal homogenization temperature (773 K) for Ti-containing alloy 2618 (2618-Ti alloy) is the same as that of alloy 2618. Combining the results of kinetic analysis and experiments, the optimized homogenizing time for Ti-containing alloy 2618 at 773 K is only 12 h, which is shorter than that for alloy 2618. The shortening of the optimized homogenizing time results mainly from the decrease of the grain size of 2618-Ti alloy.

Green Technology for the 21st Century: Ceramic Membranes

1994 ◽  
Vol 368 ◽  
Author(s):  
M. A. Anderson ◽  
W. A. Zeltner ◽  
C. M. Merritt ◽  
Professor Marc A. Anderson
Keyword(s):  
Water Pollution ◽  
Air Pollution ◽  
21St Century ◽  
Significant Contribution ◽  
Ceramic Membranes ◽  
Green Technology ◽  
Environmental Crisis ◽  
Hazardous Wastes ◽  
Storage Tanks ◽  
Indoor And Outdoor

ABSTRACTThe nineties have brought us to an era of environmental crisis. We are faced with problems of air pollution, both indoor and outdoor, acid rain, water pollution, hazardous wastes, toxic landfills and leaking storage tanks in our soil, to name a few. Our rapid advances into the industrial and technological age have contributed to these problems. However, our advancing technology in the areas of remediation and such “green” engineering tools as ceramic membranes can certainly make a significant contribution in terms of environmental clean-up and a healthier world.

scholarly journals Indoor Air Pollution Effects On Pediatric Asthma Are Submicron Aerosol Particles Dependent

2021 ◽  
Author(s):  
Izabele Juskiene ◽  
Nina Prokopciuk ◽  
Ulrich Franck ◽  
Algirdas Valiulis ◽  
Vaidotas Valskys ◽  
...  
Keyword(s):  
Air Pollution ◽  
Particle Size ◽  
Indoor Air ◽  
Primary Schools ◽  
Indoor Air Pollution ◽  
Size Range ◽  
School Age Children ◽  
School Age ◽  
Particle Size Range ◽  
Aerosol Pollution

Abstract The school environment is crucial for the child’s health and wellbeing. On the other hand, the data about the role of school’s aerosol pollution on the etiology of chronic non-communicable diseases remain scarce.Objectives: To evaluate the level of indoor aerosol pollution in primary schools and its relation to the incidence of doctor’s diagnosed asthma among younger school-age children.Methods: The cross-sectional study was carried out in 11 primary schools of Vilnius during one year of education from autumn 2017 to spring 2018. Particle number (PNC) and mass (PMC) concentrations in the size range of 0.3-10 µm were measured using an Optical Particle Sizer (OPS, TSI model 3330). The annual incidence of doctor’s diagnosed asthma in each school was calculated retrospectively from the data of medical records.Results: The total number of 6-11 years old children participated in the study was 3638. The incidence of asthma per school ranged from 1.8 to 6.0%. Mean indoor air pollution based on measurements in classrooms during the lessons was calculated for each school. Levels of PNC and PMC in schools ranged between 33.0-168.0 part/cm 3 and 1.7-6.8 µg/m 3 , respectively. There was a statistically significant correlation between the incidence of asthma and PNC as well as asthma and PMC in the particle size range of 0.3-1 µm (r=0.66, p=0.028) and (r=0.71, p=0.017) respectively. No significant correlation was found between asthma incidence and indoor air pollution in the particle size range of 0.3-2.5 and 0.3-10 µm.Conclusions: We concluded that the number and mass concentrations of indoor air aerosol pollution in primary schools in the particle size range of 0.3-1 μm are primarily associated with the incidence of doctor’s diagnosed asthma among younger school age-children.

Life-cycle energy and CO2 analysis of stormwater treatment devices

2008 ◽  
Vol 58 (5) ◽  
pp. 985-993 ◽  
Author(s):  
R. M. Andrew ◽  
É.-T. Vesely
Keyword(s):  
Life Cycle ◽  
Co2 Emissions ◽  
Significant Contribution ◽  
Life Time ◽  
Energy Requirements ◽  
Stormwater Treatment ◽  
Sand Filter ◽  
Infiltration Rates ◽  
Time Savings ◽  
The Difference

Environmental impacts associated with the construction, maintenance, and disposal of low-impact stormwater management devices are one aspect that should be considered during decision-making and life-cycle assessment (LCA) is a suitable method for quantifying such impacts. This paper reports a pilot study that employs LCA to compare life-cycle energy requirements and CO2 emissions of two stormwater devices in New Zealand. The two devices are a raingarden servicing an urban feeder road, and a sand filter that could have been installed in its stead. With an assumed life-time of 50 years, the life-cycle energy requirements of the built raingarden were almost 20% less than for the sand filter, while the CO2 emissions were 30% less. Our analysis shows that given the difference between the infiltration rates used in the raingarden design (0.3 m/day) and measured during monitoring (3 m/day) there was potential to make significantly greater life-time savings using a smaller design for the raingarden that would have also met the treatment efficiency expectations. The analysis highlights the significant contribution of transportation–of both materials and staff–and ongoing maintenance to a treatment device's life-cycle energy and CO2 profiles.

scholarly journals DEPENDENCE OF ENDOCRINOLOGICAL MORBIDITY OF ADULT POPULATION ON THE USE OF CHEMICALS IN AGRICULTURE AND AIR POLLUTION

2017 ◽  
pp. 24-26
Author(s):  
A.R. Sabirzyanov ◽  
R.Ya. Khamitova
Keyword(s):  
Air Pollution ◽  
Carbon Monoxide ◽  
Data Analysis ◽  
Significant Contribution ◽  
Adult Population ◽  
Anthropogenic Load ◽  
Resource Saving ◽  
Atmospheric Air ◽  
Endocrine Diseases

Data analysis 2000–2014 established correlations of endocrinological morbidity of adult population with the parameters of resource-saving technologies of tillage, the use of pesticides, anthropogenic load on atmospheric air in the region with developed diversified industry and growing (r = 0,57÷1,0). The frequency of new cases of endocrine diseases direct highly significant contribution was made by the volume of emissions of carbon monoxide and hydrocarbons in the incidence – the area treated with pesticides.

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