Reduction of Toxic Gas Emissions During Gas Cabinet Manifold Vent Purge Cycles Using a Novel Scrubbing Material.

1989 ◽  
Vol 145 ◽  
Author(s):  
Bruce A. Luxon ◽  
V. R Vaughan ◽  
J. V. Mcmanus ◽  
G. M. Tom
Keyword(s):  
High Capacity ◽  
Threshold Limit Value ◽  
Ca 125 ◽  
New Family ◽  
Limit Value ◽  
Long Time ◽  
Microelectronics Industry ◽  
Semiconductor Fabrication ◽  
Process Gases ◽  
Reduce Emissions

AbstractThe rapid growth of the microelectronics industry has spawned environmental problems associated with the process gases used to prepare semiconductors. Historically, many of these problems have been ignored because relatively low volumes of gases are associated with semiconductor fabrication; however, the exceptionally high toxicity of these materials (e.g. arsine, phosphine, silane, etc.) can cause major problems, especially for small quantity hazardous waste generators. Large commercial users have built expensive facilities for handling these materials, but small quantity generators typically have vented to the atmosphere through their exhaust ductwork. This is particularly true during cylinder changes where the gas manifold is repeatedly purged into the ductwork of the facility with no other treatment.A new family of novel vent gas scrubbers that will cost-effectively reduce toxic air emissions below the Threshold Limit Value (TLV) during cylinder changes is described. Called a vent gas scrubber (VGS), this device combines high capacity, high selectivity and very high capture-effectiveness. These properties permit the VGS to be extremely compact (ca. 125 ml), last a long time in use (several years or more) and to reduce emissions to well below the TLV for improved gas handling safety.

scholarly journals PERBEDAAN LAMA WAKTU PAlANAN TERHADAP KANDUNGAN TIMBAL PADA MAKANAN JAlANANGORENGAN YANG DIJUAL DI ALUN-ALUN KOTA MADIUN TAHUN 2014

2014 ◽  
Vol 12 (2) ◽  
Author(s):  
Evi Damayanti ◽  
Rusmiati . ◽  
Lilis Prihastini
Keyword(s):  
Exposure Time ◽  
Threshold Limit Value ◽  
The Body ◽  
Motor Vehicles ◽  
Test Results ◽  
Limit Value ◽  
Significant Difference ◽  
Systemic Impact ◽  
Long Time ◽  
Lead Metal

One of the pollutants produced by motor vehicles is lead (Pb). Lead (Pb) is a toxic anddangerous heavy metal to the environment and have a systemic impact in human bodies. Lead (Pb) canenter the body through inhalation, snacks sold on the roadside without cover. This will be even moredangerous if the food is exposed for a long time. The purpose of this research was to determine the levelsof lead (Pb) in snacks based on exposure time during peddling in Madiun square in 2014.The research followed pre-experimental design using posttest only protocol. Data collection wasdone by sampling, documentation and observation. The population under study was the food peddlers offried soybean cakes along the roadside around Madiun square. The samples to be examined were friedsoybean cakes, in 3 replications and to be performed 3 times in each treatment and the exposure time ofthe 9 samples. Sampling was drawn by random sampling and data was to subjected to descriptiveanalysis.The results obtained from this research include the facts that all samples did contain heavymetals lead (Pb). The average levels of lead (Pb) before exposure was <0.01 .rnq / I, after an hourexposure was 0,021 mg / I, and after 2 hours of exposure was 0,033 mg / I. The concentration of lead(Pb) remained below the designated requirement, the Threshold Limit Value established by the DirectorGeneral of POMNo. HK.00.06.1.52.4011 regarding the maximum limit of lead metal contamination in food.One way ANOVA statistical test results obtained (p) > a so that HO means no Significant differencebetween exposure times i.e. a hours, 1 hour, and 2 hours in term of the lead content.The conclusion of this study is: there was no significant difference in lead content in snacks,namely the soybean cakes with the exposure time of 0 hours, 1 hour, and 2 hours, although there was anincrease based on the length of exposure time. Pedlers are encouraged to use a cloth cover / Stelling toreduce contamination of lead (Pb). Further research is necessaryto study the aerial concentration of leadin Madiun square.

EXPERIMENTAL SUBSTANTIATION OF THE MAXIMUM ALLOWABLE CONCENTRATION OF DIOCTYL TEREPHTHALATE IN THE AIR OF THE WORKING AREA

2020 ◽  
pp. 34-38
Author(s):  
A. S. Radilov ◽  
S. A. Solntseva ◽  
I. E. Shkaeva ◽  
S. A. Dulov ◽  
E. V. Vivulanets ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Functional State ◽  
Hematological Parameters ◽  
Inhalation Exposure ◽  
Threshold Limit Value ◽  
Maximum Allowable Concentration ◽  
Limit Value ◽  
Threshold Limit ◽  
The Central Nervous System

Toxicity and hazard assessment of dioctyl terephthalate (DOTP) was performed in acute, subacute, and chronic experiments, and its principal toxicometry parameters were determined.It was found that on single exposure DOTP exhibits low toxicity and hazard. No resorptive and irritant effects on skin and mucous membrane of eyes were detected in animal experiments. The single inhalation exposure threshold limit value was set at 300 mg/m3, based on the results of monitoring of the functional state of the central nervous system and myocardium and hematological parameters.Thirty-day subacute experiments (oral administration, inhalation exposure, and skin applications) revealed no accumulation of the compound.Four-month chronic exposure to DOTP aerosols (concentration 96,8 mg/m3) caused disorder of the functional state of the central nervous system and myocardium, changes in the hematological and biochemical parameters, gas and acid-base status of the blood, and morphological changes in the lungs and heart. Embryotoxic, genotoxic and gonadotoxic effects were not detected.The chronic inhalation exposure threshold limit value for DOTP (Limch) was set at 18,6 mg/m3, and the concentration of 3,4 mg/m3 was found to be ineffective.The maximum allowable concentration of DOTP in the air of the working area was set at 3,0 mg/m3, hazard class 3.

scholarly journals Recent Progress in Torovirus Molecular Biology

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 435
Author(s):  
Makoto Ujike ◽  
Fumihiro Taguchi
Keyword(s):  
Molecular Biology ◽  
Recent Progress ◽  
Reverse Genetics ◽  
Cultured Cells ◽  
Host Adaptation ◽  
Economic Losses ◽  
New Family ◽  
Enteric Diseases ◽  
Long Time ◽  
Medical Importance

Torovirus (ToV) has recently been classified into the new family Tobaniviridae, although it belonged to the Coronavirus (CoV) family historically. ToVs are associated with enteric diseases in animals and humans. In contrast to CoVs, which are recognised as pathogens of veterinary and medical importance, little attention has been paid to ToVs because their infections are usually asymptomatic or not severe; for a long time, only one equine ToV could be propagated in cultured cells. However, bovine ToVs, which predominantly cause diarrhoea in calves, have been detected worldwide, leading to economic losses. Porcine ToVs have also spread globally; although they have not caused serious economic losses, coinfections with other pathogens can exacerbate their symptoms. In addition, frequent inter- or intra-recombination among ToVs can increase pathogenesis or unpredicted host adaptation. These findings have highlighted the importance of ToVs as pathogens and the need for basic ToV research. Here, we review recent progress in the study of ToV molecular biology including reverse genetics, focusing on the similarities and differences between ToVs and CoVs.

Stress-release design for high-capacity and long-time lifespan aqueous zinc-ion batteries

2021 ◽  
pp. 100799
Author(s):  
Hao Luo ◽  
Bo Wang ◽  
Jiahuang Jian ◽  
Fangdong Wu ◽  
Li Peng ◽  
...  
Keyword(s):  
High Capacity ◽  
Zinc Ion ◽  
Stress Release ◽  
Long Time

scholarly journals The Physical and Chemical Air Quality, Worker’s Characteristics, and Respiratory Symptoms Among Printing Workers in Surabaya

2016 ◽  
Vol 8 (2) ◽  
pp. 195
Author(s):  
Devi Anggar Oktaviani ◽  
Corie Indria Prasasti
Keyword(s):  
Air Quality ◽  
Respiratory Symptoms ◽  
Threshold Limit Value ◽  
Dust Collector ◽  
Printing Industry ◽  
Cross Sectional ◽  
Administrative Control ◽  
Limit Value ◽  
Control Application ◽  
Physical And Chemical

Abstract: Printing industry is an industry which in its production process generate air pollutants such as Particulate Matter (PM). The exceeds limit of PM2,5 can cause respiratory symptoms, cardiovascular disease, and pulmonary function disorder. The objective of this study was to analyze physical and chemical air quality and respiratory symptoms among printing industry workers in Surabaya. It was observational study with cross sectional approach and analyzed descriptively. The physical and chemical air quality was measured by Thermohygrometer and Haz Dust EPAM 5000 at three different areas in production unit. Worker’s characteristics and respiratory symptoms were obtained from 20 respondent’s questionnaires. The highest concentration of PM2,5 level was at cutting room (area 1), which maximum concentration was 20.0 μg/m3 and the average was 6.1 μg/m3. The result showed that PM2,5 levels was below threshold limit value. It is suggested to printing industry to improve administrative control application by managing work period and useing mask, to clean ventilation, dust collector, or production facilities and to examine health status regularly to public health center for workers at printing industry.Keywords: physical and chemical air quality, printing industry, respiratory symptoms

scholarly journals Analysis The Level Of PM2,5 And Lung Function Of Organic Fertilizer Industry Workers In Nganjuk

2019 ◽  
Vol 11 (2) ◽  
pp. 141
Author(s):  
Imfatul Tria Nur Azizah
Keyword(s):  
Lung Function ◽  
Organic Fertilizer ◽  
Threshold Limit Value ◽  
Cross Sectional ◽  
Fertilizer Industry ◽  
Limit Value ◽  
Function Impairment ◽  
Packing Process ◽  
Cross Sectional Design ◽  
Lung Function Impairment

Organic fertilizer industry in Nganjuk uses manure as basic materials of production. Its process produced particulate matter 2,5 (PM2,5) in the form of dust and smoke. PM2,5 can be inhaled and be retained until alveoli, so it is potentially caused lung function impairment to the workers. The objective of this research was to analyzed the level of PM2,5 and lung function of organic fertilizer industry workers in Nganjuk. The type of this research was observasional descriptive quantitative with cross sectional design. The research sample was using total population of 10 production workers. The result of this research showed that the level of PM2,5 inhaled which exceeded Threshold Limit Value (TLV) or > 3 mg/m3 were on 2 workers who worked on drying and packing process. The average of PM2,5  environment level which exceeded TLV were on manufacturing of granuls, heating and packing process area. Workers who had lung function impairment were 4 workers (40%). Lung function impairment more likely found in workers with exposure of PM2,5 inhaled≤ 3 mg/m3, has age 41 – 60 years, worked period < 5 years, always using cloth as respiratory protective equipment, and had worked in the other places either direct or indirect exposure of dust. The conclusion of this research is production workers of organic fertilizer industry in Nganjuk has risk of lung function impairment. Suggestions for the owner of organic fertilizer industry in Nganjuk are to install natural and unnatural ventilations and to provide air purifying respirators.

scholarly journals Adsorption and Recovery using Vaporization of Liquid Fluorocarbon Precursor

2020 ◽  
Vol 58 (6) ◽  
pp. 397-402
Author(s):  
Junyoung Park ◽  
Byoungmoon Oh ◽  
Kyongnam Kim
Keyword(s):  
Semiconductor Device ◽  
High Capacity ◽  
Etching Process ◽  
Temperature Plasma ◽  
Ion Energy ◽  
Ion Energy Distribution ◽  
Recovery Processes ◽  
Layer Structures ◽  
Device Structures ◽  
Long Time

PFC gas is primarily used during the etching process in the manufacture of ULSIs and in cleaning after CVD processes. PFC is classified as a greenhouse gas that stays in the atmosphere for a long time and has a high GWP. High capacity and high integration have been achieved in recent years as semiconductor device structures have been replaced by vertical layer structures, and the consumption of PFC gas has exploded due to the increase in high aspect ratio and patterning processes. Therefore, many researchers have been working on methods to decompose, recover, and reuse the gas after the etching process to reduce the emissions of PFC gas. In this study, etching and recovery processes were performed using C5F8 in L-FC which is in liquid phase at room temperature. Among the L-FCs, C5F8 gas has a high C/F ratio, similar to that of the C4F8 gas, which is a conventional PFC gas. In addition, to confirm its reusability, the recovered C5F8 was injected back into the chamber, and the electron temperature, plasma density, and ion energy distribution were analyzed. Based on these experimental data, the reliability of the etch processes performed with recovered C5F8 gas was evaluated, and the possibility of reusing the recovered C5F8 gas was confirmed.

Metallic Mercury Contamination of the Dental Operatory

1975 ◽  
Vol 17 (4) ◽  
pp. 346-355 ◽  
Author(s):  
Richard G. Domey
Keyword(s):  
San Antonio ◽  
Threshold Limit Value ◽  
Mercury Contamination ◽  
Metallic Mercury ◽  
General Lack ◽  
Limit Value ◽  
Threshold Limit ◽  
Routine Monitoring ◽  
Cleaning Methods

The American Conference of Governmental Industrial Hygienists 1971 standard threshold limit value (TLV) of 0.55 mgHg/m of air was found to be exceeded frequently in a sample of 60 dental operatories in San Antonio, Texas. Significant differences in contamination among laboratories were found, among sites within operatories, and among times of day, correlated with kilograms of mercury used, average number of amalgams inserted per day, age of operatories, height of carpeting pile, cleaning methods, frequency of cleaning, and general lack of routine monitoring and use of bioassays. Recommendations for control of metallic mercury contamination in dental operatories are offered.

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