• Geomechanics and Engineering
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• v.37 no.4
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• pp.419-429
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• 2024

The primary goal was to assess how the addition of cement dust, a byproduct known to be harmful, could be used to stabilize clay. Various percentages of cement dust were added to soil samples, which were then subjected to triaxial testing at different rates of strain using an unconsolidated undrained triaxial machine. Six different rates of strain were applied to analyze the response of the clay under different conditions, resulting in 216 triaxial sample tests. As the percentage of cement dust in the clay samples increased, there was a noticeable increase in the strength properties of the clay, indicating a positive effect of cement dust on the clay's strength characteristics. Higher rates of strain during testing led to increased strength properties of the clay. Varying cement dust content influenced the impact of increasing the rate of strain on the clay's strength properties. Higher cement dust content reduced the sensitivity of the clay to changes in strain rate, indicating that the clay became less responsive to changes in strain rate as cement dust content increased. Potential for Clay Stabilization Cement dust proved the potential to enhance the strength properties of clay, indicating its potential utility in clay stabilization applications. Both higher percentages of cement dust and higher rates of strain were found to increase the clay's strength. It's essential to consider both the percentage of cement dust and the rate of strain when assessing the strength properties of clay in practical applications.

• Journal of Environmental Health Sciences
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• v.33 no.6
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• pp.479-487
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• 2007

[ $PM_{2.5}$ ], particulate matter less than 2.5 um in a diameter, can penetrate deeply into the lungs. Exposure to $PM_{2.5}$ has been associated with increased hospital visits for respiratory aliments as well as increase mortality. $PM_{2.5}$ is a byproduct of combustion processes and as such has a complex composition including a variety of metallic elements, inorganic and organic compounds as well as biogenic materials (microorganisms, proteins, etc). In this study, the average concentrations of fine particulates $PM_{2.5}$ have been measured simultaneously in Asan and Seoul, Korea, by using particulate matter portable sampler from September 2001 to August 2002. Sample collection filters were analyzed by ICP-OES to determine the concentrations of metallic elements (As, Ni, Fe, Cr, Cd, Cu, Pb, Zn, Si). Annual mean $PM_{2.5}$ concentrations in Asan and Seoul were 37.70 and $45.83\;{\mu}g/m^3$, respectively. The highest concentrations of $PM_{2.5}$ were found in spring season in both cities and the concentrations of measured metallic elements except As in Asan were higher than those in Seoul, suggesting that yellow dust in spring could affect $PM_{2.5}$ concentrations in Asan rather than Seoul. The correlation coefficients of Pb and Zn were 0.343 for Asan and 0.813 for Seoul during non-yellow dust condition, suggesting that Pb and Zn were influenced with the same sources. The correlation coefficients between Si and Fe in the fine particulate mode were 0.999 (Asan) and 0.998 (Seoul) during yellow dust condition. It was suggested that these two elements were impacted by soil-related transport from China during the yellow dust storm condition.

• Journal of the Korean Institute of Gas
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• v.28 no.2
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• pp.76-83
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• 2024

In the semiconductor manufacturing process, the Diffusion process generates various reactive by-products. These by-products are deposited inside the pipes of post-processing and exhaust treatment systems, posing a potential risk of substantial dust explosions. In this study, three methods material verification, selection of analysis samples, and risk analysis were employed to address the substances produced during the Diffusion process. Among the materials handled in the Diffusion process, ZrO₂, TEOD, and E-DEOS were identified as raw material capable of generating by-product dust. Test for Minimum Ignition Energy and dust explosion were conducted on the by-products collected from each processing facility. The results indicated that, in the case of MIE, none of the by-products ignited. However, the dust explosion test revealed that ZrO₂ exhibited a maximum pressure of 7.6 bar and K_st value of 73.3 bar·m/s, its explosive hazard. Consequently, to mitigate such risks in semiconductor processes, it is excessive buildup.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.11
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• pp.1593-1598
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• 2003

Nutritional evaluation of some agro-industrial byproducts available in Samoa [dry brewers' grains (DBG), cocoa shell (CS), cocoa dust (CD) and desiccated coconut waste meal (DCWM)] available in Samoa was carried out using both the in vivo and in vitro techniques. In the in vivo study 24 Anglo-nubian goats were offered by-products with other feed ingredients to compound four different diets. The goats were randomly allocated to 4 diets on the basis of liveweight (18.7-0.3kg). The ADF content of the byproducts followed a similar trend to NDF. The byproducts have a high content of organic matter (91.0-95.4%). Gross energy (GE) content was higher in DCWM (25.1 MJ/kg DM), closely followed by CD (23.2 MJ/kg DM). Concentrate intake was significantly different (p<0.05) among the goats. Average daily live weight gains were 105, 92, 88 and 97 g/goat/day for DBG, CS, CD and DCWM, respectively. Daily live weight gains were higher (p<0.05) in the goats that received DBG, while the least gain was obtained in the goats that received CS byproduct diet. DM digestibility was significantly higher (p<0.05) in the goats on DBG diet than in the other goats. The least DM digestibility was obtained in the goats that received CD diet (p>0.05). CP digestibility followed a similar pattern to DM digestibility. The digestibility of NDF and ADF was influenced by the nature of the diets. The digestibility of OM and GE were best (p<0.05) in the goats that received DBG, DCWM and CS byproduct diets than in CD. Significant differences (p<0.05) among the byproducts were recorded for net gas production. Potential gas production (a+b) ranged from 7.064 to 42.17 ml. Organic matter digested (OMD) from gas production value at 24 h was higher in DBG (47.6 g/kg DM) and this was followed by DCWM (42.5 g/kg DM). The least OMD was obtained in CD (17.9 g/kg DM). A significant difference (p<0.05) in DM disappearance after 4, 8, 16, 24, 48 and 72 h was recorded. The potential and effective degradability varied significantly (p<0.05) from 85.95-99.6 g/kg DM and from 39.9-65.8%, respectively. The digestibility of the byproducts in both the in vivo and in in vitro techniques demonstrated that they are potential source of feed ingredients for ruminant livestock in Samoa and possibly in the other small Pacific Island countries. On the basis of their potential degradability the byproducts could be ranked in the following order:DCWM>DBG>CD>CS. In conclusion, the results obtained suggest that all the byproducts can contribute to ruminant livestock diets without adverse effects on feed intake, growth rate and apparent nutrient digestibility coefficients.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.2
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• pp.89-96
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• 1975

The experiment was carried out to investigate the chemical properties of cement kiln dusts, abundantly produced from cement industry as a byproduct, and their effectiveness on rice yield. The field experiment was conducted on the acid paddy soil developed on basalt at Dongsong-Myon, Chulwon-Kun, Gangwon-Do. Two kinds of cement kiln dusts were used ; By Pass (BP) collected from the suspension preheater and Electric Precipitate (EP) from the cottrell electric precipitator. The levels of cement kiln dust applied were 100kg/10a, 200kg/10a and 300kg/10a, and the recommended variety "Nong Back" was adopted for this experiment. The results obtained are summarized as follows ; 1. The component of cement kiln dusts seems to be quite suitable for liming material. BP has 55% alkalinity, 41.7% of soluble calcium, 9.8% of soluble magnesium and 4.5% of water soluble silicate, while EP has 53.5% alkalinity, 41.7% soluble calcium, 8.3% soluble magnesium and 1% water soluble silicate. 2. The relative effectiveness of cement kiln dust in the soil will be superior due to very fine particle size. EP pass through completely 270 mesh screen, and 95% of BP pass through 150 mesh screen, 68% passing 270 mesh. 3. BP application at the rate of 100kg/10a increased 21% of rice yield as compared with control and EP 15%. It was observed that the affected yield components were increased panicle number per hill, grain number per panicle and 1,000 grains weight. 4. The application of optimum amount (100kg/10a) of cement kiln dusts accelerated the uptake of nutrients by rice plant and increased rice yield. However, the excess amounts (200kg/10a, 300kg/10a) of cement kiln dusts retarded the uptake of nutrients from soil.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1972.03a
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• pp.6-7
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• 1972

The air pollutants can be classified into the irritant gas and the asphixation gas, and the irritant gas is closely related to the otorhinolaryngological diseases. The common irritant gases are nitrogen oxides, sulfur oxides, hydrogen carbon compounds, and the potent and irritating PAN (peroxy acyl nitrate) which is secondarily liberated from photosynthesis. Those gases adhers to the mucous membrane to result in ulceration and secondary infection due to their potent oxidizing power. 1. Sulfur dioxide gas Sulfur dioxide gas has the typical characteristics of the air pollutants. Because of its high solubility it gets easily absorbed in the respiratory tract, when the symptoms and signs by irritation become manifested initially and later the resistance in the respiratory tract brings central about pulmonary edema and respiratory paralysis of origin. Chronic exposure to the gas leads to rhinitis, pharyngitis, laryngitis, and olfactory or gustatory disturbances. 2. Carbon monoxide Toxicity of carbon monoxide is due to its deprivation of the oxygen carrying capacity of the hemoglobin. The degree of the carbon monoxide intoxication varies according to its concentration and the duration of inhalation. It starts with headache, vertigo, nausea, vomiting and tinnitus, which can progress to respiratory difficulty, muscular laxity, syncope, and coma leading to death. 3. Nitrogen dioxide Nitrogen dioxide causes respiratory disturbances by formation of methemoglobin. In acute poisoning, it can cause pulmonary congestion, pulmonary edema, bronchitis, and pneumonia due to its strong irritation on the eyes and the nose. In chronic poisoning, it causes chronic pulmonary fibrosis and pulmonary edema. 4. Ozone It has offending irritating odor, and causes dryness of na sopharyngolaryngeal mucosa, headache and depressed pulmonary function which may eventually lead to pulmonary congestion or edema. 5. Smog The most outstanding incident of the smog occurred in London from December 5 through 8, 1952, because of which the mortality of the respiratory diseases increased fourfold. The smog was thought to be due to the smoke produced by incomplete combustion and its byproduct the sulfur oxides, and the dust was thought to play the secondary role. In new sense, hazardous is the photochemical smog which is produced by combination of light energy and the hydrocarbons and oxidant in the air. The Yonsei University Institute for Environmental :pollution Research launched a project to determine the relationship between the pollution and the medical, ophthalmological and rhinopharyngological disorders. The students (469) of the "S" Technical School in the most heavily polluted area in Pusan (Uham Dong district) were compared with those (345) of "K" High School in the less polluted area. The investigated group had those with subjective symptoms twice as much as the control group, 22.6% (106) in investigated group and 11.3% (39) in the control group. Among those symptomatic students of the investigated group. There were 29 with respiratory symptoms (29%), 22 with eye symptoms (21%), 50 with stuffy nose and rhinorrhea (47%), and 5 with sore thorat (5%), which revealed that more than half the students (52%) had subjective symptoms of the rhinopharyngological aspects. Physical examination revealed that the investigated group had more number of students with signs than those of the control group by 10%, 180 (38.4%) versus 99 (28.8%). Among the preceding 180 students of the investigated group, there were 8 with eye diseases (44%), 1 with respiratory disease (0.6%), 97 with rhinitis (54%), and 74 with pharyngotonsillitis (41%) which means that 95% of them had rharygoical diseases. The preceding data revealed that the otolaryngological diseases are conspicuously outnumbered in the heavily polluted area, and that there must be very close relationship between the air pollution and the otolaryngological diseases, and the anti-pollution measure is urgently needed.