222-S LABORATORY FUME HOOD TESTING STUDY

International Nuclear Information System (INIS)

RUELAS, B.H.

2007-01-01

The 222-S Laboratory contains 155 active fume hoods that are used to support analytical work with radioactive and/or toxic materials. The performance of a fume hood was brought into question after employees detected odors in the work area while mixing chemicals within the subject fume hood. Following the event, testing of the fume hood was conducted to assess the performance of the fume hood. Based on observations from the testing, it was deemed appropriate to conduct performance evaluations of other fume hoods within the laboratory

Comparative microscopic study of human and rat lungs after overexposure to welding fume.

Science.gov (United States)

Antonini, James M; Roberts, Jenny R; Schwegler-Berry, Diane; Mercer, Robert R

2013-11-01

Welding is a common industrial process used to join metals and generates complex aerosols of potentially hazardous metal fumes and gases. Most long-time welders experience some type of respiratory disorder during their time of employment. The use of animal models and the ability to control the welding fume exposure in toxicology studies have been helpful in developing a better understanding of how welding fumes affect health. There are no studies that have performed a side-by-side comparison of the pulmonary responses from an animal toxicology welding fume study with the lung responses associated with chronic exposure to welding fume by a career welder. In this study, post-mortem lung tissue was donated from a long-time welder with a well-characterized work background and a history of extensive welding fume exposure. To simulate a long-term welding exposure in an animal model, Sprague-Dawley rats were treated once a week for 28 weeks by intratracheal instillation with 2mg of a stainless steel, hard-surfacing welding fume. Lung tissues from the welder and the welding fume-treated rats were examined by light and electron microscopy. Pathological analysis of lung tissue collected from the welder demonstrated inflammatory cell influx and significant pulmonary injury. The poor and deteriorating lung condition observed in the welder examined in this study was likely due to exposure to very high levels of potentially toxic metal fumes and gases for a significant number of years due to work in confined spaces. The lung toxicity profile for the rats treated with welding fume was similar. For tissue samples from both the welder and treated rats, welding particle accumulations deposited and persisted in lung structures and were easily visualized using light microscopic techniques. Agglomerates of deposited welding particles mostly were observed within lung cells, particularly alveolar macrophages. Analysis of individual particles within the agglomerates showed that these

Profiling mild steel welding processes to reduce fume emissions and costs in the workplace.

Science.gov (United States)

Keane, Michael J; Siert, Arlen; Chen, Bean T; Stone, Samuel G

2014-05-01

To provide quantitative information to choose the best welding processes for minimizing workplace emissions, nine gas metal arc welding (GMAW) processes for mild steel were assessed for fume generation rates, normalized fume generation rates (milligram fume per gram of electrode consumed), and normalized generation rates for elemental manganese, nickel, and iron. Shielded metal arc welding (SMAW) and flux-cored arc-welding (FCAW) processes were also profiled. The fumes were collected quantitatively in an American Welding Society-type fume chamber and weighed, recovered, homogenized, and analyzed by inductively coupled atomic emission spectroscopy for total metals. The processes included GMAW with short circuit, globular transfer, axial spray, pulsed spray, Surface Tension Transfer™, Regulated Metal Deposition™, and Cold Metal Transfer™ (CMT) modes. Flux-cored welding was gas shielded, and SMAW was a single rod type. Results indicate a wide range of fume emission factors for the process variations studied. Fume emission rates per gram of electrode consumed were highest for SMAW (~13 mg fume g(-1) electrode) and lowest for GMAW processes such as pulsed spray (~1.5mg g(-1)) and CMT (~1mg g(-1)). Manganese emission rates per gram of electrode consumed ranged from 0.45 mg g(-1) (SMAW) to 0.08 mg g(-1) (CMT). Nickel emission rates were generally low and ranged from ~0.09 (GMAW short circuit) to 0.004 mg g(-1) (CMT). Iron emission rates ranged from 3.7 (spray-mode GMAW) to 0.49 mg g(-1) (CMT). The processes studied have significantly different costs, and cost factors are presented based on a case study to allow comparisons between processes in specific cost categories. Costs per linear meter of weld were $31.07 (SMAW), $12.37 (GMAW short circuit), and $10.89 (FCAW). Although no single process is the best for minimizing fume emissions and costs while satisfying the weld requirements, there are several processes that can minimize emissions. This study provides

Udvikling af The Dementia Carer Needs Assessment Questionnaire

DEFF Research Database (Denmark)

Clemmensen, Trine Holt; Lauridsen, Henrik Hein; Kristensen, Hanne Kaae

redskab til at identificere behov for støtte blandt pårørende til personer med demens - the Dementia Carer Needs Assessment Questionnaire (DCNAQ). Redskabet skal udvikles til at være selvrapporteret og let anvendeligt i klinisk praksis. Metode Projektet er tilrettelagt som et tre-årigt Ph.d. forløb, hvor......Baggrund Demens er en sygdom som påvirker hele familien, og pårørende bidrager i høj grad med omsorg for personen med demens i hverdagen. At være pårørende til en person med demens kan være belastende både fysisk, psykisk og socialt (1-4). I praksis mangler der standardiserede redskaber til...... der tages udgangspunkt i WHO’s Internationale Klassifikation af funktionsevne, funktionsevnenedsættelse og helbredstilstand (ICF) (7). Projektet gennemføres som to delstudier. Studie 1 - udvikling Materiale og metode: 32 pårørende til personer med demens og 16 sundhedsprofessionelle inviteres til...

Characterization of Tungsten Inert Gas (TIG) Welding Fume Generated by Apprentice Welders

Science.gov (United States)

Graczyk, Halshka; Lewinski, Nastassja; Zhao, Jiayuan; Concha-Lozano, Nicolas; Riediker, Michael

2016-01-01

Tungsten inert gas welding (TIG) represents one of the most widely used metal joining processes in industry. Its propensity to generate a greater portion of welding fume particles at the nanoscale poses a potential occupational health hazard for workers. However, current literature lacks comprehensive characterization of TIG welding fume particles. Even less is known about welding fumes generated by welding apprentices with little experience in welding. We characterized TIG welding fume generated by apprentice welders (N = 20) in a ventilated exposure cabin. Exposure assessment was conducted for each apprentice welder at the breathing zone (BZ) inside of the welding helmet and at a near-field (NF) location, 60cm away from the welding task. We characterized particulate matter (PM4), particle number concentration and particle size, particle morphology, chemical composition, reactive oxygen species (ROS) production potential, and gaseous components. The mean particle number concentration at the BZ was 1.69E+06 particles cm−3, with a mean geometric mean diameter of 45nm. On average across all subjects, 92% of the particle counts at the BZ were below 100nm. We observed elevated concentrations of tungsten, which was most likely due to electrode consumption. Mean ROS production potential of TIG welding fumes at the BZ exceeded average concentrations previously found in traffic-polluted air. Furthermore, ROS production potential was significantly higher for apprentices that burned their metal during their welding task. We recommend that future exposure assessments take into consideration welding performance as a potential exposure modifier for apprentice welders or welders with minimal training. PMID:26464505

The Pozzolanic reaction of silica fume

DEFF Research Database (Denmark)

Jensen, Ole Mejlhede

2012-01-01

Silica fume is a very important supplementary cementitious binder in High-Performance and Ultra High-Performance Concretes. Through its pozzolanic reaction the silica fume densifies the concrete micro-structure, in particular it strengthens the paste-aggregate interfacial transition zone. In the ......Silica fume is a very important supplementary cementitious binder in High-Performance and Ultra High-Performance Concretes. Through its pozzolanic reaction the silica fume densifies the concrete micro-structure, in particular it strengthens the paste-aggregate interfacial transition zone....... In the present paper different aspects of the pozzolanic reaction of silica fume are investigated. These include chemical shrinkage, isothermal heat development and strength development. Key data for these are given and compared with theoretical calculations, and based on presented measurements the energy...

Work-principle model for predicting toxic fumes of nonideal explosives

Energy Technology Data Exchange (ETDEWEB)

Wieland, Michael S. [National Institute of Occupational Safety and Health, Pittsburgh Research Center, P.O. Box 18070, Pittsburgh, PA 15236-0070 (United States)

2004-08-01

The work-principle from thermodynamics was used to formulate a model for predicting toxic fumes from mining explosives in underground chamber tests, where rapid turbulent combustion within the surrounding air noticeably changes the resulting concentrations. Two model constants were required to help characterize the reaction zone undergoing rapid chemical transformations in conjunction with heat transfer and work output: a stoichiometry mixing fraction and a reaction-quenching temperature. Rudimentary theory with an unsteady uniform concentration gradient was taken to characterize the combustion zone, yielding 75% for the mixing fraction. Four quenching temperature trends were resolved and compared to test results of ammonium nitrate compositions with different fuel-oil percentages (ANFO). The quenching temperature 2345 K was the optimum choice for fitting the two major components of fume toxicity: carbon monoxide (CO) and total nitrogen oxides (NO{sub X}). The resulting two-constant model was used to generate comparisons for test results of ANFO compositions with additives. Though respectable fits were usually found, charge formulations which reacted weakly could not be resolved numerically. The work-principle model yields toxic concentrations for a range of charge formulations, making it a useful tool for investigating the potential hazard of released fumes and reducing the risk of unwanted incidents. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

Reduction of Biomechanical and Welding Fume Exposures in Stud Welding.

Science.gov (United States)

Fethke, Nathan B; Peters, Thomas M; Leonard, Stephanie; Metwali, Mahmoud; Mudunkotuwa, Imali A

2016-04-01

The welding of shear stud connectors to structural steel in construction requires a prolonged stooped posture that exposes ironworkers to biomechanical and welding fume hazards. In this study, biomechanical and welding fume exposures during stud welding using conventional methods were compared to exposures associated with use of a prototype system that allowed participants to weld from an upright position. The effect of base material (i.e. bare structural beam versus galvanized decking) on welding fume concentration (particle number and mass), particle size distribution, and particle composition was also explored. Thirty participants completed a series of stud welding simulations in a local apprenticeship training facility. Use of the upright system was associated with substantial reductions in trunk inclination and the activity levels of several muscle groups. Inhalable mass concentrations of welding fume (averaged over ~18 min) when using conventional methods were high (18.2 mg m(-3) for bare beam; 65.7 mg m(-3) for through deck), with estimated mass concentrations of iron (7.8 mg m(-3) for bare beam; 15.8 mg m(-3) for through deck), zinc (0.2 mg m(-3) for bare beam; 15.8 mg m(-3) for through deck), and manganese (0.9 mg m(-3) for bare beam; 1.5 mg m(-3) for through deck) often exceeding the American Conference of Governmental Industrial Hygienists Threshold Limit Values (TLVs). Number and mass concentrations were substantially reduced when using the upright system, although the total inhalable mass concentration remained above the TLV when welding through decking. The average diameters of the welding fume particles for both bare beam (31±17 nm) through deck conditions (34±34 nm) and the chemical composition of the particles indicated the presence of metallic nanoparticles. Stud welding exposes ironworkers to potentially high levels of biomechanical loading (primarily to the low back) and welding fume. The upright system used in this study improved exposure

Characterization of Tungsten Inert Gas (TIG) Welding Fume Generated by Apprentice Welders.

Science.gov (United States)

Graczyk, Halshka; Lewinski, Nastassja; Zhao, Jiayuan; Concha-Lozano, Nicolas; Riediker, Michael

2016-03-01

Tungsten inert gas welding (TIG) represents one of the most widely used metal joining processes in industry. Its propensity to generate a greater portion of welding fume particles at the nanoscale poses a potential occupational health hazard for workers. However, current literature lacks comprehensive characterization of TIG welding fume particles. Even less is known about welding fumes generated by welding apprentices with little experience in welding. We characterized TIG welding fume generated by apprentice welders (N = 20) in a ventilated exposure cabin. Exposure assessment was conducted for each apprentice welder at the breathing zone (BZ) inside of the welding helmet and at a near-field (NF) location, 60cm away from the welding task. We characterized particulate matter (PM4), particle number concentration and particle size, particle morphology, chemical composition, reactive oxygen species (ROS) production potential, and gaseous components. The mean particle number concentration at the BZ was 1.69E+06 particles cm(-3), with a mean geometric mean diameter of 45nm. On average across all subjects, 92% of the particle counts at the BZ were below 100nm. We observed elevated concentrations of tungsten, which was most likely due to electrode consumption. Mean ROS production potential of TIG welding fumes at the BZ exceeded average concentrations previously found in traffic-polluted air. Furthermore, ROS production potential was significantly higher for apprentices that burned their metal during their welding task. We recommend that future exposure assessments take into consideration welding performance as a potential exposure modifier for apprentice welders or welders with minimal training. © The Author 2015. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Assessment of occupational hazards, health problems and safety ...

African Journals Online (AJOL)

Background: Petrol station attendants encounter several hazards and health problems while working. This study was conducted to determine the ... Hazards reported included inhalation of petrol fumes 145 (67.4%), confrontation from customers 112 (52.1%) and noise 98 (45.6%). Health problems reported included ...

Transport and Deposition of Welding Fume Agglomerates in a Realistic Human Nasal Airway.

Science.gov (United States)

Tian, Lin; Inthavong, Kiao; Lidén, Göran; Shang, Yidan; Tu, Jiyuan

2016-07-01

Welding fume is a complex mixture containing ultra-fine particles in the nanometer range. Rather than being in the form of a singular sphere, due to the high particle concentration, welding fume particles agglomerate into long straight chains, branches, or other forms of compact shapes. Understanding the transport and deposition of these nano-agglomerates in human respiratory systems is of great interest as welding fumes are a known health hazard. The neurotoxin manganese (Mn) is a common element in welding fumes. Particulate Mn, either as soluble salts or oxides, that has deposited on the olfactory mucosa in human nasal airway is transported along the olfactory nerve to the olfactory bulb within the brain. If this Mn is further transported to the basal ganglia of the brain, it could accumulate at the part of the brain that is the focal point of its neurotoxicity. Accounting for various dynamic shape factors due to particle agglomeration, the current computational study is focused on the exposure route, the deposition pattern, and the deposition efficiency of the inhaled welding fume particles in a realistic human nasal cavity. Particular attention is given to the deposition pattern and deposition efficiency of inhaled welding fume agglomerates in the nasal olfactory region. For particles in the nanoscale, molecular diffusion is the dominant transport mechanism. Therefore, Brownian diffusion, hydrodynamic drag, Saffman lift force, and gravitational force are included in the model study. The deposition efficiencies for single spherical particles, two kinds of agglomerates of primary particles, two-dimensional planar and straight chains, are investigated for a range of primary particle sizes and a range of number of primary particles per agglomerate. A small fraction of the inhaled welding fume agglomerates is deposited on the olfactory mucosa, approximately in the range 0.1-1%, and depends on particle size and morphology. The strong size dependence of the deposition

Danske virksomheders effektivitet og investering i forskning og udvikling

DEFF Research Database (Denmark)

Dilling-Hansen, Mogens; Madsen, Erik Strøjer; Smith, Valdemar

2001-01-01

Et af virksomhedernes motiver til at investere i forskning og udviklinger er at forbedre produktiviteten. Denne velkendte sammenhæng er tidligere undersøgt på danske data, se Smith, Dilling-Hansen m.fl. (2000). Investeringer i forskning og udvikling opbygger en ikke-materiel kapital i virksomhede...

SDT og børns og unges udvikling

DEFF Research Database (Denmark)

Ravn, Ib

2017-01-01

Hvilken rolle spiller autonomi i børns og unges udvikling? En temmelig stor rolle, ligesom et underskud af autonomi - som når forældre kontrollerer deres børn - er en væsentlig årsag til psykiske sygdomme. Det er resultatet af en stor forskningsoversigt offentliggjort af tre ledende kræfter bag s...... selvbestemmelsesteorien (Self-Determination Theory, SDT)....

Exposure to Cooking Fumes and Acute Reversible Decrement in Lung Functional Capacity

Directory of Open Access Journals (Sweden)

Masoud Neghab

2017-10-01

Full Text Available Background: Being exposed to cooking fumes, kitchen workers are occupationally at risk of multiple respiratory hazards. No conclusive evidence exists as to whether occupational exposure to these fumes is associated with acute and chronic pulmonary effects and symptoms of respiratory diseases. Objective: To quantify the exposure levels and evaluate possible chronic and acute pulmonary effects associated with exposure to cooking fumes. Methods: In this cross-sectional study, 60 kitchen workers exposed to cooking fumes and 60 unexposed employees were investigated. The prevalence of respiratory symptoms among these groups was determined through completion of a standard questionnaire. Pulmonary function parameters were also measured before and after participants' work shift. Moreover, air samples were collected and analyzed to quantify their aldehyde, particle, and volatile organic contents. Results: The mean airborne concentrations of formaldehyde, acetaldehyde, and acrolein was 0.45 (SD 0.41, 0.13 (0.1, and 1.56 (0.41 mg/m3, respectively. The mean atmospheric concentrations of PM1, PM2.5, PM7, PM10, and total volatile organic compounds (TVOCs was 3.31 (2.6, 12.21 (5.9, 44.16 (16.6, 57 (21.55 μg/m3, and 1.31 (1.11 mg/m3, respectively. All respiratory symptoms were significantly (p<0.05 more prevalent in exposed group. No significant difference was noted between the pre-shift mean of spirometry parameters of exposed and unexposed group. However, exposed workers showed cross-shift decrease in most spirometry parameters, significantly lower than the pre-shift values and those of the comparison group. Conclusion: Exposure to cooking fumes is associated with a significant increase in the prevalence of respiratory symptoms as well as acute reversible decrease in lung functional capacity.

Dispersibility of silica fume in mortar and its effect on properties of mortar. Silica fume no bunsan to mortar no shotokusei

Energy Technology Data Exchange (ETDEWEB)

Oga, H; Uomoto, T [The University of Tokyo, Tokyo (Japan). Institute of Industrial Science

1992-08-01

Effect of silica fume dispersibility on concrete characteristics was discussed. Properties of mortar mixed with silica fume to exhibit compression strength varied with displacement rates, patterns, and mixing time of silica fume. In submerged curing age of 28 days, the compression strength in a mortar mixed with silica fume at 10% was affected only very little by the mixing time for both pelletizing and non-pelletizing types for up to 180 seconds. The strength increased thereafter with the mixing time. The compression strength at 1020 seconds showed higher value by about 150 kgf/cm [sup 2] than when no silica fume is added, with a difference because of patterns disappearing. In the case of a mixing time of 1020 seconds, neutralization depth receives very little effect from a pattern difference, and decreases with increasing displacement rate. Neutralization coefficient of the mortar mixed with silica fume at 10% decreased with the mixing time, and it was possible to suppress the neutralization coefficient to 25% of the case without silica fume addition in a 1020-second mixing. 7 refs., 8 figs., 1 tab.

Miljørigtig udvikling i produktfamilier - en håndbog

DEFF Research Database (Denmark)

Lenau, Torben Anker; Frees, Niels; Olsen, Stig Irving

UMIP-metoden (Udvikling af Miljøvenlige Industrielle Pro-dukter) til miljøvurdering af produkter blev udviklet i perioden 1991-1996. En erfaring fra UMIP-projektet er, at produktudviklere og beslutningstagere har behov for enkle og ikke mindst operationelle konklusioner på miljøvurderinger af...

Strategi til udbredelse og udvikling af aquaponik

OpenAIRE

Bartholin, Aline; Nielsen, Per

2014-01-01

Denne rapport omhandler, hvorledes aquaponik i fremtiden skal udbredes med henblik på at produktionsmetoden bliver en del af den etablerede fødevaresektor. Ud fra et interview med PlanteLaboratoriet som er en del af foreningen Akvaponisk Selskab, samt observationer af en workshop afholdt af PlanteLaboratoriet forsøger vi at kortlægge den førte strategi til udbredelse og udvikling af aquaponik, samt undersøge hvorledes aquaponik som innovation bliver taget imod af mulige adoptere. Empirien sam...

Dry fumes purifying system using anhydrous baking soda; Procede chimique d`epuration des fumees au bicarbonate de soude anhydre

Energy Technology Data Exchange (ETDEWEB)

Anon.

1998-04-01

UNISYSTEMS has developed the industrial implementation of the chemical process using anhydrous backing soda, patented by SOLVAY, for purifying fumes containing inorganic salts and sulphur oxides as polluting agents. The system can be applied to industrial processes releasing this type of polluting agents in the fumes at a temperature over 160 deg C, as it is specially indicated in purifying fumes coming from ceramic firing kilns. (authors)

Udvikling af arbejdet i callcentre - sådan gik det

DEFF Research Database (Denmark)

Wiegman, Inger-Marie; Møller, Niels

Et treårigt projekt om arbejdet i callcentre blev afsluttet i 2006. Projektet startede i 2003 og gennemførte udvikling af arbejdet, organisationen og kompetencerne i tre store danske virksomheder. Det var Nykredit, Danske Bank og TDC, som har deres egne callcentre. 700 medarbejdere og ledere deltog...

[Analysis on oil fume particles in catering industry cooking emission].

Science.gov (United States)

Tan, De-Sheng; Kuang, Yuan-Cheng; Liu, Xin; Dai, Fei-Hong

2012-06-01

By measuring the particulate matter of oil fume which is over 10 microm or below 10 microm separately and using microradiography and Electrical Low Pressure Impactor (ELPI), it is found out the distributing characteristic of oil fume particles in catering industry cooking emission. The result shows that the diameter of the oil fume particles which was sedimentated in the kitchen is between 10-400 microm, the concentration peak value is between 10-100 microm. The diameter of oil fume aerosol is mostly smaller than 1 microm, while the concentration peak value is between 0.063-0.109 microm. In addition, the mass concentration peak value is between 6.560-9.990 microm. Through the analysis to the physical characteristics of oil fume from catering industry cooking emissions, the eigenvalue of the oil fume has been found and the feature matter for monitoring the oil fume has been discovered to provide a reasonable standard for controlling and monitoring the catering industry cooking emission.

IMPROVEMENT OF EXPANSIVE SOIL BY USING SILICA FUME

Directory of Open Access Journals (Sweden)

Kawther Y. AL-Soudany

2018-01-01

Full Text Available Expansive soils are characterized by their considerable volumetric deformations representing a serious challenge for the stability of the engineering structures such as foundations. Consequently, the measurements of swelling properties, involving swelling and swell pressure, become extremely important in spite of their determination needs a lot of time with costly particular equipment. Thus, serious researches attempts have been tried to remedy such soils by means of additives such as cement, lime, steel fibers, stone dust, fly ash and silica fume. In this research the study of silica fume has studied to treatment expansion soil, the clay soil was brought from Al-Nahrawan in Baghdad. The soil selected for the present investigation prepared in laboratory by mixing natural soil with different percentages of bentonite (30, 50 and 70% by soil dry weight. The test program included the effect of bentonite on natural soil then study the effect of silica fume (SF on prepared soil by adding different percentage of silica fume (3, 5, and 7 by weight to the prepared soils and the influence of these admixtures was observed by comparing their results with those of untreated soils (prepared soils. The results show that both liquid limit and plasticity index decreased with the addition of silica fume, while the plastic limit is increase with its addition. As well as, a decrease in the maximum dry unit weight with an increase in the optimum water contents have been obtained with increasing the percentage of addition of the silica fume. It is also observed an improvement in the free swell, swelling pressure by using silica fume. It can be concluded that the silica fume stabilization may be used as a successful way for the treatment of expansive clay.

Skrivepædagogik i lyset af Forenklede Fælles Mål, sproglig udvikling som tværgående tema og læringsmålstyret undervisning

DEFF Research Database (Denmark)

Christensen, Mette Vedsgaard

Det tværgående tema Sproglig udvikling anviser, hvordan der blandt andet kan arbejdes med skrivning og sproglig udvikling i fag. Med udgangspunkt i udviklingsprojekter relateret til sproglig udvikling og et udviklingsprojekt om skrivepædagogik i en 7.klasse med genrepædagogik som ramme præsentere...... bud på en opdateret skrivepædagogik med udgangspunkt i FFM....

Analysis of polycyclic aromatic hydrocarbons in cooking oil fumes.

Science.gov (United States)

Li, S; Pan, D; Wang, G

1994-01-01

Various samples of cooking oil fumes were analyzed to an effort to study the relationship between the high incidence of pulmonary adenocarcinoma in Chinese women and cooking oil fumes in the kitchen. Polycyclic aromatic hydrocarbons (PAHs) in samples of cooking oil fumes were extracted, chromatographed, and measured by fluorescence spectrophotometer. The samples included oil fumes from three commercial cooking oils and fumes from three catering shops. All samples contained benzo(a)pyrene (BaP) and dibenzo (a,h)anthracene (DBahA). In addition, the concentration of DBahA was 5.7 to 22.8 times higher than that of BaP in the fume samples. Concentrations of BaP and DBahA were, respectively, 0.463 and 5.736 micrograms/g in refined vegetable oil, 0.341 and 3.725 micrograms/g in soybean oil, and 0.305 and 4.565 micrograms/g in vegetable oil. Investigation of PAH concentrations at three catering shops showed that the level of BaP at a Youtiao (deep-fried twisted dough sticks) shop was 4.18 micrograms/100 m3, 2.28 micrograms/100 m3 at a Seqenma (candied fritters) workshop, and 0.49 micrograms/100 m3 at a kitchen of a restaurant; concentrations of DBahA were 33.80, 14.41, and 3.03 micrograms/100 m3, respectively. The high concentration of carcinogens, such as BaP and DBahA, in cooking oil fumes might help explain why Chinese women, who spend more time exposed to cooking oil fumes than men, have a high incidence of pulmonary adenocarcinoma.

Reduction of fume damage in forests: report on the symposium on fume damage held in Tharandt from 30th September to 2nd October 1965

Energy Technology Data Exchange (ETDEWEB)

Daessler, H G; Ranft, H

1967-01-01

Summaries are presented of 15 papers, including: extent of variation in fume resistance in Larix and problems of breeding for resistance (Schoenbach); results of research on fume damage on experimental areas in E. Germany (H. Enderlin) (noting differences in resistance to SO/sub 2/ damage of various species of Picea, Pinus, and Abies, varieties of Pseudotsuga taxifolia and provenances of Pinus contorta and Larix spp., effect of fertilizers on resistance, and mass selection of resistant planting stock in practice); resistance of Pinus omorika to fume damage (K.F. Wentzel); chemical and physiological studies on the metabolism of the assimilation organs of conifers affected by SO/sub 2/ (S. Boertitz); basic physiological and phenological studies on the preliminary selection of conifers for SO/sub 2/ resistance (M. Vogl); fertilizer trials in fume-damaged pine stands on Dueben Heath (H. Krauss); insect pests on young pine stands in fume-damaged regions in Poland (Z. Sierpinski); birch and alder pests in industrial regions (Z. Schnaider); management of young fume-damaged spruce stands (E. Pelz); effect of fumes from the potash industry on forest stands in East Germany (E. Ewert); the distribution of injurious substances in leaves (G. Halbwachs); emission of SO/sub 2/ absorbed by spruce needles (J. Materna); and estimating fume damage expected near future power stations (H. Lux).

Study of radon transport through concrete modified with silica fume

International Nuclear Information System (INIS)

Chauhan, R.P.; Kumar, Amit

2013-01-01

The concentration of radon in soil usually varies between a few kBq/m 3 and tens or hundreds of kBq/m 3 depending upon the geographical region. This causes the transport of radon from the soil to indoor environments by diffusion and advection through the pore space of concrete. To reduce indoor radon levels, the use of concrete with low porosity and a low radon diffusion coefficient is recommended. A method of reducing the radon diffusion coefficient through concrete and hence the indoor radon concentration by using silica fume to replace an optimum level of cement was studied. The diffusion coefficient of the concrete was reduced from (1.63 ± 0.3) × 10 −7 to (0.65 ± 0.01) × 10 −8 m 2 /s using 30% substitution of cement with silica fume. The compressive strength of the concrete increased as the silica-fume content increased, while radon exhalation rate and porosity of the concrete decreased. This study suggests a cost-effective method of reducing indoor radon levels. -- Highlights: • Radon diffusion study through silica fume modified concrete was carried out. • Radon diffusion coefficient of concrete decreased with increase of silica fume contents. • Compressive strength increased with increase of silica fume. • Radon exhalation rates and porosity of samples decreased with addition of silica fume. • Radon diffusion coefficient decreased to 2.6% by 30% silica fume substitution

78 FR 33894 - Proposed Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment...

Science.gov (United States)

2013-06-05

... chemicals and fumes caused by open burn pits. DATES: Written comments and recommendations on the proposed... to ``OMB Control No. 2900-NEW, Open Burn Pit Registry Airborne Hazard Self-Assessment Questionnaire.... Title: Open Burn Pit Registry Airborne Hazard Self-Assessment Questionnaire, VA Form 10-10066. OMB...

Interlaboratory comparison on 137Cs activity concentration in fume dust

International Nuclear Information System (INIS)

Tzika, Faidra; Hult, Mikael; Burda, Oleksiy; Arnold, Dirk; Sibbens, Goedele; Caro Marroyo, Belén; Gómez–Mancebo, Maria Belén; Peyrés, Virginia; Moser, Hannah; Ferreux, Laurent; Šolc, Jaroslav; Dryák, Pavel; Fazio, Aldo; Luca, Aurelian; Vodenik, Branko; Reis, Mario

2015-01-01

A comparison was conducted, between 11 European National Metrology Institutes and EC-JRC, on measurement of 137 Cs activity concentration in fume dust. As test material an activity standard produced from real contaminated fume dust was used. The standard material consisted of 13 cylindrical samples of compressed fume dust. The material contained 137 Cs and 60 Co of reference activity concentrations of (9.72±0.10) Bq/g and (0.450±0.018) Bq/g, respectively, for the reference date of 1 June 2013, determined using the comparison results. The organization and results of the intercomparison, as well as the process of obtaining reliable reference values are presented. - Highlights: • A European comparison was conducted on measurement of 137 Cs activity in fume dust. • Participants used high resolution gamma ray spectrometry. • Efficiency calibration included Monte Carlo, numerical and experimental methods. • Reference 137 Cs and 60 Co activity concentrations in the fume dust were determined. • A new traceable activity standard of fume dust matrix is available to end-users.

Decreasing biotoxicity of fume particles produced in welding process.

Science.gov (United States)

Yu, Kuei-Min; Topham, Nathan; Wang, Jun; Kalivoda, Mark; Tseng, Yiider; Wu, Chang-Yu; Lee, Wen-Jhy; Cho, Kuk

2011-01-30

Welding fumes contain heavy metals, such as chromium, manganese, and nickel, which cause respiratory diseases and cancer. In this study, a SiO(2) precursor was evaluated as an additive to the shielding gas in an arc welding process to reduce the biotoxicity caused by welding fume particles. Transmission electron micrographic images show that SiO(2) coats on the surface of welding fume particles and promotes particle agglomeration. Energy dispersive X-ray spectroscopy further shows that the relative amount of silicon in these SiO(2)-coated agglomerates is higher than in baseline agglomerates. In addition, Escherichia coli (E. coli) exposed to different concentrations of pure SiO(2) particles generated from the arc welding process exhibits similar responses, suggesting that SiO(2) does not contribute to welding fume particle toxicity. The trend of E. coli growth in different concentrations of baseline welding fume particle shows the most significant inhibition occurs in higher exposure concentrations. The 50% lethal logarithmic concentrations for E. coli in arc welding particles of baseline, 2%, and 4.2% SiO(2) precursor additives were 823, 1605, and 1800 mg/L, respectively. Taken together, these results suggest that using SiO(2) precursors as an additive to arc welding shielding gas can effectively reduce the biotoxicity of welding fume. Copyright © 2010 Elsevier B.V. All rights reserved.

Welding fume exposure and chronic obstructive pulmonary disease in welders.

Science.gov (United States)

Koh, D-H; Kim, J-I; Kim, K-H; Yoo, S-W

2015-01-01

Occupational exposure is estimated to contribute 15% to the burden of chronic obstructive pulmonary disease (COPD). Welding fumes are suspected to accelerate the decline of lung function and development of COPD. To examine the relationship between welding fume exposure and COPD in Korean shipyard welders. The study involved a group of male welders working at two shipyards who underwent an annual health examination in 2010. Subjects completed a questionnaire about smoking habits and occupational history and a pulmonary function test (PFT) was carried out with strict quality control measures. Welding fume exposure concentrations were estimated using 884 measurements taken between 2002 and 2009 in one of the shipyards. Multiple linear and logistic regression was employed to evaluate the association between cumulative fume exposure and lung function parameters, controlling for age, height and cigarette smoking. Two hundred and forty subjects participated, with a mean age of 48 and mean work duration of 15 years. The mean cumulative fume exposure was 7.7mg/m(3). The prevalence of COPD was 15%. FEV1 and FVC showed non-significant negative correlations with cumulative fume exposure. Odds ratios of COPD were significantly elevated for the middle (3.9; 95% CI 1.4-13.3) and high exposure groups (3.8; 95% CI 1.03-16.2) compared with the low fume exposure group. Our findings support an association between welding fume exposure and increased risk of COPD. Further prospective study is needed to investigate whether this is a causal relationship. © The Author 2014. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Comparison of Effect of Metakaolin and silica Fume on Fly Ash Concrete Performance

Directory of Open Access Journals (Sweden)

Hou Yunfen

2016-01-01

Full Text Available Silica fume is a common mineral admixture used in HSC and HPC, but being its high price and shrinkage in concrete, its usage is under restrictions. As a new mineral admixture, metakaolin gets more and more attention. In order to compare the difference between silica fume and metakaolin, the effects of metakaolin and silica fume on concrete workability, compressive strength, and chloride penetration resistance are studied. It shows that incorporating with fly ash together, silica fume reduces the slump extension, but metakaolin can increases it; silica fume can increases early strength more than metakaolin can, but it isn’t useful for later and long-time strength; metakaolin not only can increase early strength, but also can improve long-time strength. Silica fume and metakaolin can increase the chloride penetration resistance. As a new mineral additive, metakaolin can play a role in concrete which silica fume does, even much better than silica fume.

Pulmonary fibrosis and exposure to steel welding fume.

Science.gov (United States)

Cosgrove, M P

2015-12-01

Arc welders who have been exposed to high concentrations of steel welding fume for prolonged periods of time may develop pulmonary fibrosis but the nature of the fibrotic changes has been debated over the last 80 years without any clear international consensus. To characterize the nature of the pulmonary fibrosis that develops in response to steel welding fume exposure and to provide a working hypothesis that would explain the findings of the existing research, to provide a platform for future research and to inform future occupational and clinical management of welders with pulmonary effects from welding fume. Review of the world literature on pulmonary fibrosis and welding of steel in all languages using PubMed, with further secondary search of references in the articles found in the primary search. Google and Reference Manager were used as further confirmatory search tools. Only case series and case reports were found but these provided consistent evidence that the consequence of exposure to steel welding fume at high levels for a prolonged period of time is a type of pulmonary fibrosis similar to, and possibly the same as, respiratory bronchiolitis which eventually develops into desquamative interstitial pneumonia with ongoing exposure. Steel welding fume may cause an occupational respiratory bronchiolitis which may develop into de squamative interstitial pneumonia with ongoing exposure. This concept may explain the difficulties in interpreting the wider literature on welding fume and lung function at lower exposures and may also explain the increased risk of lung cancer in welders. © The Author 2015. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Genotoxic Effects of Exposure to Gasoline Fumes on Petrol Pump Workers.

Science.gov (United States)

Shaikh, Amrin; Barot, Darshana; Chandel, Divya

2018-04-01

Petrol pump workers are occupationally exposed to gasoline and its fumes consisting of several mutagenic chemicals. To evaluate the genotoxic effects of exposure to gasoline fumes on petrol pump workers. The study groups included 70 petrol pump workers (exposed group) and 70 healthy age-matched individuals with no known exposure (comparison group). Buccal micronucleus cytome assay (BMCyt) was performed to check the genotoxicity caused due to inhalation of gasoline fumes. The frequencies of micronucleated cells, nuclear bud, condensed chromatin cells, karyorrhectic cells, pyknotic cells, and karyolytic cells were significantly higher in the exposed workers compared to the comparison group. Exposure to gasoline fumes is associated with increased frequency of cell abnormalities. This may lead to various health consequences including cancer in those occupationally exposed to gasoline fumes.

It-baseret inklusion af elever med udviklings- og opmærksomhedsproblemer i folkeskolen

DEFF Research Database (Denmark)

Voldborg, Hanne; Sorensen, Elsebeth Korsgaard; De Lopez, Kristine M. Jensen

med ADHD); Kristian Andreasen (spiludvikler og direktør i firmaet Kanda; udvikler af læringsspillet Runerod); Rune Gråbæk (pædagogisk konsulent, Ringsted kommune) samt Henrik Grum (pædagogisk leder, CSV Sydfyn; tidligere medarbejder på projektet). Projektledelsen og projektmedarbejderne vil derudover...

DELEØKONOMISKE POTENTIALER FOR STRATEGISK REGIONAL UDVIKLING OG BÆREDYGTIG VÆKST

DEFF Research Database (Denmark)

Olsen, Flemming; Jørgensen, Michael Søgaard; Burgess, Camilla Newcomb

Denne rapport ”Deleøkonomiske potentialer for strategisk regional udvikling og bæredygtig vækst” er resultatet af et udviklingsforløb gennemført af cphfacilitation for Region Hovedstaden i november 2016 – januar 2017. Forløbet er led i regionens udmøntning af sin regionale vækst- og udviklingsstr...

Soluble transition metals cause the pro-inflammatory effects of welding fumes in vitro

International Nuclear Information System (INIS)

McNeilly, Jane D.; Heal, Mathew R.; Beverland, Iain J.; Howe, Alan; Gibson, Mark D.; Hibbs, Leon R.; MacNee, William; Donaldson, Ken

2004-01-01

Epidemiological studies have consistently reported a higher incidence of respiratory illnesses such as bronchitis, metal fume fever (MFF), and chronic pneumonitis among welders exposed to high concentrations of metal-enriched welding fumes. Here, we studied the molecular toxicology of three different metal-rich welding fumes: NIMROD 182, NIMROD c276, and COBSTEL 6. Fume toxicity in vitro was determined by exposing human type II alveolar epithelial cell line (A549) to whole welding fume, a soluble extract of fume or the 'washed' particulate. All whole fumes were significantly toxic to A549 cells at doses >63 μg ml -1 (TD 50; 42, 25, and 12 μg ml -1 , respectively). NIMROD c276 and COBSTEL 6 fumes increased levels of IL-8 mRNA and protein at 6 h and protein at 24 h, as did the soluble fraction alone, whereas metal chelation of the soluble fraction using chelex beads attenuated the effect. The soluble fraction of all three fumes caused a rapid depletion in intracellular glutathione following 2-h exposure with a rebound increase by 24 h. In addition, both nickel based fumes, NIMROD 182 and NIMROD c276, induced significant reactive oxygen species (ROS) production in A549 cells after 2 h as determined by DCFH fluorescence. ICP analysis confirmed that transition metal concentrations were similar in the whole and soluble fractions of each fume (dominated by Cr), but significantly less in both the washed particles and chelated fractions. These results support the hypothesis that the enhanced pro-inflammatory responses of welding fume particulates are mediated by soluble transition metal components via an oxidative stress mechanism

Hepatotoxic and Nephrotoxic Effects of Petroleum Fumes on Petrol ...

African Journals Online (AJOL)

DR SULEIMAN

Hepatotoxic and Nephrotoxic Effects of Petroleum Fumes on Petrol Attendants in Ibadan, Nigeria. *1A.L. Ogunneye ... inhalation of petrol fumes is associated with adverse effect on the kidney and liver function. ..... neurotoxicity in mice. African ...

Size-separated particle fractions of stainless steel welding fume particles - A multi-analytical characterization focusing on surface oxide speciation and release of hexavalent chromium.

Science.gov (United States)

Mei, N; Belleville, L; Cha, Y; Olofsson, U; Odnevall Wallinder, I; Persson, K-A; Hedberg, Y S

2018-01-15

Welding fume of stainless steels is potentially health hazardous. The aim of this study was to investigate the manganese (Mn) and chromium (Cr) speciation of welding fume particles and their extent of metal release relevant for an inhalation scenario, as a function of particle size, welding method (manual metal arc welding, metal arc welding using an active shielding gas), different electrodes (solid wires and flux-cored wires) and shielding gases, and base alloy (austenitic AISI 304L and duplex stainless steel LDX2101). Metal release investigations were performed in phosphate buffered saline (PBS), pH 7.3, 37°, 24h. The particles were characterized by means of microscopic, spectroscopic, and electroanalytical methods. Cr was predominantly released from particles of the welding fume when exposed in PBS [3-96% of the total amount of Cr, of which up to 70% as Cr(VI)], followed by Mn, nickel, and iron. Duplex stainless steel welded with a flux-cored wire generated a welding fume that released most Cr(VI). Nano-sized particles released a significantly higher amount of nickel compared with micron-sized particle fractions. The welding fume did not contain any solitary known chromate compounds, but multi-elemental highly oxidized oxide(s) (iron, Cr, and Mn, possibly bismuth and silicon). Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Genotoxic Effects of Exposure to Gasoline Fumes on Petrol Pump Workers

Directory of Open Access Journals (Sweden)

Amrin Shaikh

2018-04-01

Full Text Available Background: Petrol pump workers are occupationally exposed to gasoline and its fumes consisting of several mutagenic chemicals. Objective: To evaluate the genotoxic effects of exposure to gasoline fumes on petrol pump workers. Methods: The study groups included 70 petrol pump workers (exposed group and 70 healthy age-matched individuals with no known exposure (comparison group. Buccal micronucleus cytome assay (BMCyt was performed to check the genotoxicity caused due to inhalation of gasoline fumes. Results: The frequencies of micronucleated cells, nuclear bud, condensed chromatin cells, karyorrhectic cells, pyknotic cells, and karyolytic cells were significantly higher in the exposed workers compared to the comparison group. Conclusion: Exposure to gasoline fumes is associated with increased frequency of cell abnormalities. This may lead to various health consequences including cancer in those occupationally exposed to gasoline fumes.

Silica fume effect on retention characteristics of portland cement for uranium (VI)

International Nuclear Information System (INIS)

Tan Hongbin; Ma Xiaoling; Li Yuxiang

2005-01-01

With simulated groundwater as leachant, the retention capabilities of the portland cement, which contains different amount of silica fume, are investigated under 25 degree C and 42 days. The results indicate that silica fume can improve the retention capabilities of portland cement for uranium. When the cement contains 15% silica fume, the diffusion coefficient is 7 x 10 -3 cm 3 · -1 . It is only 5.5% of the cement without containing fume. (authors)

When are fume-cupboards necessary in hospital radioisotope laboratories

Energy Technology Data Exchange (ETDEWEB)

Birks, J L [Singleton Hospital, Swansea (UK)

1976-06-01

Suggestions are made for procedures likely to require the provision of efficient fume-cupboards in hospital radioisotope laboratories. All such departments undertaking in vivo radioisotope procedures will require a supply of sterile materials, but only some of these will also require a fume-cupboard, since the use of a relatively inexpensive aseptic cabinet, without air flow and exhaust system, may suffice for such procedures as the labelling of blood cells or plasma. Efficient fume-cupboards may be required in hospital laboratories that are routinely concerned with the elution of generators of isotopes such as /sup 99/Tcsup(m) and /sup 113/Insup(m), the sterilization of radiopharmaceuticals (e.g. technetium-sulphur colloid) requiring the use of a pressure cooker, and the storage and handling of therapeutic quantities of /sup 131/I. Copious general ventilation of isotope rooms may be preferable to the too frequent incorporation of unnecessary fume-cupboards.

Increased lung function decline in blue-collar workers exposed to welding fumes.

Science.gov (United States)

Thaon, Isabelle; Demange, Valérie; Herin, Fabrice; Touranchet, Annie; Paris, Christophe

2012-07-01

There is no consensus at the present time about the effect of welding on lung function decline. This study compared lung function decline between blue-collar workers exposed and not exposed to welding fumes in a French longitudinal cohort of 21,238 subjects aged 37 to 52 years at inclusion. Medical data, occupation, sector of activity, and spirometry were recorded twice by occupational physicians in 1990 and 1995. A job-exposure matrix was used to identify 503 male blue-collar workers exposed to welding fumes and 709 control subjects and to define the weekly duration of exposure to welding fumes. Baseline lung function parameters were higher in workers exposed to welding fumes than in control subjects. After a 5-year follow-up, welding-fume exposure was associated with a nonsignificant decline in FVC (P = .06) and FEV(1) (P = .07) after adjustment for age, pack-years, BMI, and baseline value of the parameter. A significant accelerated decline in FEV(1) (P = .046) was also observed in never smokers exposed to welding fumes. An “exposure-response” relationship was observed between FEV(1) decline and weekly duration of exposure to welding fumes in nonsmokers but not in smokers. Blue-collar workers exposed to welding fumes showed accelerated decline in lung function, which, in nonsmokers, was related to weekly duration of exposure.

Short term exposure to cooking fumes and pulmonary function

Directory of Open Access Journals (Sweden)

Qvenild Torgunn

2009-05-01

Full Text Available Abstract Background Exposure to cooking fumes may have different deleterious effects on the respiratory system. The aim of this study was to look at possible effects from inhalation of cooking fumes on pulmonary function. Methods Two groups of 12 healthy volunteers (A and B stayed in a model kitchen for two and four hours respectively, and were monitored with spirometry four times during twenty four hours, on one occasion without any exposure, and on another with exposure to controlled levels of cooking fumes. Results The change in spirometric values during the day with exposure to cooking fumes, were not statistically significantly different from the changes during the day without exposure, with the exception of forced expiratory time (FET. The change in FET from entering the kitchen until six hours later, was significantly prolonged between the exposed and the unexposed day with a 15.7% increase on the exposed day, compared to a 3.2% decrease during the unexposed day (p-value = 0.03. The same tendency could be seen for FET measurements done immediately after the exposure and on the next morning, but this was not statistically significant. Conclusion In our experimental setting, there seems to be minor short term spirometric effects, mainly affecting FET, from short term exposure to cooking fumes.

Kommunernes arbejde med sundhedsfremme og bæredygtig udvikling i relation til folkeskolen

DEFF Research Database (Denmark)

Nordin, Lone Lindegard; Madsen, Katrine Dahl; Andersen, Tanja Thinggaard

Denne rapport præsenterer en landsdækkende undersøgelse af kommunernes arbejde med sundhedsfremme og bæredygtig udvikling i relation til folkeskolen. Undersøgelsen er udført i efteråret 2013 i Forskningscenter for sundhedsfremmende bæredygtig skoleudvikling ved DPU, Aarhus Universitet. Formålet m...

Hazardous fluid leak detector

Science.gov (United States)

Gray, Harold E.; McLaurin, Felder M.; Ortiz, Monico; Huth, William A.

1996-01-01

A device or system for monitoring for the presence of leaks from a hazardous fluid is disclosed which uses two electrodes immersed in deionized water. A gas is passed through an enclosed space in which a hazardous fluid is contained. Any fumes, vapors, etc. escaping from the containment of the hazardous fluid in the enclosed space are entrained in the gas passing through the enclosed space and transported to a closed vessel containing deionized water and two electrodes partially immersed in the deionized water. The electrodes are connected in series with a power source and a signal, whereby when a sufficient number of ions enter the water from the gas being bubbled through it (indicative of a leak), the water will begin to conduct, thereby allowing current to flow through the water from one electrode to the other electrode to complete the circuit and activate the signal.

Evaluation of characterisation techniques for particulate weld fume morphology

International Nuclear Information System (INIS)

Sterjovski, Z.; Monaghan, B.J.; Norrish, J.

2009-01-01

An evaluation of three techniques: scanning electron microscopy (SEM); transmission electron microscopy (TEM); and laser diffraction (LD), was carried out to determine the most suitable technique for the particle-size measurement of particulate-welding fume collected during the robotic gas-metal-arc welding (GMAW) of plain-carbon steel. Particulate fume was deposited onto an Al stub positioned at a horizontal distance of 30 mm and a vertical height of 50 mm from the welding arc, and was then prepared for SEM, TEM and LD sizing. Results are presented for paniculate-welding fume collected for three welding voltages (20, 23 and 26 V) and two metal-transfer modes (dip and dip/globular). TEM imaging was found to be the most effective of the three sizing technique as it was able to resolve both fine nano-particles (5 ran diameter) and coarse nano-particles (>100 mn diameter). The TEM approach showed that results determined were reproducible and that the majority of fume particles produced at the welding voltages investigated were less than 40 nm in diameter. SEM (La B6 filament) images were shown to be inadequate for the quantitative-size analysis of paniculate-welding fume due to the limited resolution of the microscope (-40 nm). However. SEM images did confirm that at a welding voltage of 23 V the majority of particle sizes produced were less than 100 nm in diameter, and thus supported the conclusion that the individual fume particles are predominantly in the nanometre size range. LD gave unexpectedly large mean particle sizes and did not detect particles less than 180 run in diameter. It is concluded that the LD technique measures particle agglomerates and/or simultaneously monitors multiple particles in the beam path.

EFFECTS OF FIRE FUMES ON ALMOND SAFETY AND QUALITY

Directory of Open Access Journals (Sweden)

Amanda Ramírez-Gandolfo

2011-08-01

Full Text Available A fire originated and burnt two cold chambers; the present study focused on almonds stored in adjacent chambers (4, 5, 6 and 13 and evaluated both their food safety and quality. Testing for polycyclic aromatic hydrocarbons, polychlorinated dibenzo-p-dioxins and dibenzofurans was carried out in affected facilities, packaging and almonds. Experimental results proved that fire fumes did not reach chambers 4-6, but traces were found in bin packaging of chamber 13; thus, packaging from this chamber were changed. Concentrations of benzo(apyrene were low enough to prove that fire fumes did not get in contact with the stored almonds. Later, only volatile compounds typical of nuts were identified in both raw and toasted almonds. Finally, a trained panel concluded that no sensory signal of fumes reaching almonds was found. This manuscript could be taken as a model protocol to establish whether fire fumes have reached and affected the safety and/or quality of foods. This information will be especially useful for insurance companies.

[Emission Characteristics of Water-Soluble Ions in Fumes of Coal Fired Boilers in Beijing].

Science.gov (United States)

Hu, Yue-qi; Ma, Zhao-hui; Feng, Ya-jun; Wang, Chen; Chen, Yuan-yuan; He, Ming

2015-06-01

Selecting coal fired boilers with typical flue gas desulfurization and dust extraction systems in Beijing as the study objects, the issues and characteristics of the water-soluble ions in fumes of coal fired boilers and theirs influence factors were analyzed and evaluated. The maximum mass concentration of total water-soluble ions in fumes of coal fired boilers in Beijing was 51.240 mg x m(-3) in the benchmark fume oxygen content, the minimum was 7.186 mg x m(-3), and the issues of the water-soluble ions were uncorrelated with the fume moisture content. SO4(2-) was the primary characteristic water-soluble ion for desulfurization reaction, and the rate of contribution of SO4(2-) in total water-soluble ions ranged from 63.8% to 81.0%. F- was another characteristic water-soluble ion in fumes of thermal power plant, and the rate of contribution of F- in total water-soluble ions ranged from 22.2% to 32.5%. The fume purification technologies significantly influenced the issues and the emission characteristics of water-soluble ions in fumes of coal fired boilers. Na+ was a characteristic water-soluble ion for the desulfurizer NaOH, NH4+ and NO3+ were characteristic for the desulfurizer NH4HCO3, and Mg2+ was characteristic for the desulfurizer MgO, but the Ca2+ emission was not increased by addition of the desulfurizer CaO or CaCO3 The concentrations of NH4+ and NO3- in fumes of thermal power plant were lower than those in fumes of industrial or heating coal fired boilers. The form of water-soluble ions was significantly correlated with fume temperature. The most water-soluble ions were in superfine state at higher fume temperature and were not easily captured by the filter membrane.

Environmental exposure to cooking oil fumes and cervical intraepithelial neoplasm

International Nuclear Information System (INIS)

Wu, M.-T.; Lee, L.-H.; Ho, C.-K.; Wu, S.-C.; Lin, L.-Y.; Cheng, B.-H.; Liu, C.-L.; Yang, C.-Y.; Tsai, H.-T.; Wu, T.-N.

2004-01-01

The fumes from cooking oil, similar to cigarette smoke, contain numerous carcinogens such as polycyclic aromatic hydrocarbons, aromatic amines, nitro-polycyclic aromatic hydrocarbons, etc. In this study, we examined the association between exposure to cooking oil fumes and the risk of cervical intraepithelial neoplasm. The study population in this nested case-control study consisted of women above the age of 19 years living in Chia-Yi County, located in the southwestern Taiwan, who had received pap smear screening between October, 1999, and December, 2000 (n=32,466). The potential cases were women having lesions greater than cervical intraepithelium neoplasm II (≥CIN2) reconfirmed by cervical biopsy (n=116). The potential controls (case: control=1:2) were age-matched (±2 years) and residence-matched women who had normal pap smears within 6 months of the cases. In total, 100 cases and 197 controls were completely interviewed by public health nurses about cooking methods, ventilation, and other potential risk factors. Women who cooked at home in a kitchen (n=269) without the presence of a fume extractor at least once a week between the ages of 20 and 40 had a 2.29 times higher risk [95% confidence interval (CI)=1.08-4.87] of developing cervical intraepithelial neoplasm than those who did not cook once a week in such a kitchen during the same age span, after adjusting for other potential confounders. This finding was further strengthened by the finding that women who did not use the fume extractors had a 2.47 times higher risk (95% CI=1.15-5.32) of developing cervical intraepithelial neoplasm than women who cooked in kitchens with fume extractors that were always switched on while cooking. We also found a joint protective effect of fume extractor use among women older than 40 years (n=202) if they used the extractors during both age spans of their lives, ages 20-40 and >40 years. Comparing our findings on women more than 40 years old who used fume extractors during

Workplace field testing of the pressure drop of particulate respirators using welding fumes.

Science.gov (United States)

Cho, Hyun-Woo; Yoon, Chung-Sik

2012-10-01

In a previous study, we concluded that respirator testing with a sodium chloride aerosol gave a conservative estimate of filter penetration for welding fume aerosols. A rapid increase in the pressure drop (PD) of some respirators was observed as fumes accumulated on the filters. The present study evaluated particulate respirator PD based on workplace field tests. A field PD tester was designed and validated using the TSI 8130 Automatic Filter Tester, designed in compliance with National Institute for Occupational and Safety and Health regulation 42 CFR part 84. Three models (two replaceable dual-type filters and one replaceable single-type filter) were evaluated against CO(2) gas arc welding on mild steel in confined booths in the workplace. Field tests were performed under four airborne concentrations (27.5, 15.4, 7.9, and 2.1 mg m(-3)). The mass concentration was measured by the gravimetric method, and number concentration was monitored using P-Trak (Model 8525, TSI, USA). Additionally, photos and scanning electron microscopy-energy dispersive X-ray spectroscopy were used to visualize and analyze the composition of welding fumes trapped in the filters. The field PD tester showed no significant difference compared with the TSI tester. There was no significant difference in the initial PD between laboratory and field results. The PD increased as a function of fume load on the respirator filters for all tested models. The increasing PD trend differed by models, and PD increased rapidly at high concentrations because greater amount of fumes accumulated on the filters in a given time. The increase in PD as a function of fume load on the filters showed a similar pattern as fume load varied for a particular model, but different patterns were observed for different models. Images and elemental analyses of fumes trapped on the respirator filters showed that most welding fumes were trapped within the first layer, outer web cover, and second layer, in order, while no fumes

Effect of Silica fume and superplasticizer on steel-concrete bond

International Nuclear Information System (INIS)

Esfahani, M. R.

2001-01-01

This paper presents a study on the influence of silica fume and super plasticizer on bond strength. The study included tests of fifty short length pull-out specimens in five series. The effect of silica fume and super plasticizer on bond strength was evaluated separately by tests of specimens made of concretes with similar strengths but different admixtures. Test results showed that the addition of silica fume in the concrete mixture had not a negative effect on bond strength. Also, there was not a considerable decrease in bond strength of specimens made of concrete with super plasticizer. Comparing the measured bond strengths normalized with respect to the square root of the concrete compressive strength, it was seen that the normalized bond strength increased with the concrete strength. this result agrees with the model previously proposed by the author for local bond strength. For the specimens made of high strength concrete including silica fume and super plasticizer, the normalized bond strength did not increase with the concrete strength

FABRICATION AND CHARACTERIZATION OF POLYIMIDE/POLYETHERSULFONE-FUMED SILICA MIXED MATRIX MEMBRANE FOR GAS SEPARATION

Directory of Open Access Journals (Sweden)

A. F. Ismail

2012-01-01

Full Text Available This study is performed primarily to investigate the feasibility of fumed silica as inorganic material towards gas separation performance of mixed matrix membrane. In this study, polyimide/polyethersulfone (PES-fumed silica mixed matrix membranes were casted using dry/wet technique. The results from the FESEM, DSC and FTIR analysis confirmed that the structure and physical properties of membrane is influenced by inorganic filler. FESEM’s cross-section view indicated good compatibility between polymer and fumed silica for all of range fumed silica used in this study. The gas separation performance of the mixed matrix membranes with fumed silica were relatively higher compared to that of the neat PI/PES membrane. PI/PES-fumed silica 5 wt% yielded significant selectivity enhancement of 7.21 and 40.47 for O2/N2, and CO2/CH4, respectively.

Occupational exposure to diesel exhaust fumes

International Nuclear Information System (INIS)

Wheatley, A. D.; Sadhra, S.

2004-01-01

There is currently no OEL for diesel fumes in the UK. This study reports parallel measurements of airborne levels of diesel fume pollutants in nine distribution depots where diesel powered fork-lift trucks (FLTs) were in use. Correlations between individual pollutants are assessed as well as their spatial distribution. Samples were collected on board FLTs and at background positions at nine distribution depots. Substances measured and the range of exposures by site were: respirable dust (n = 76) GM ≤ 80-179 μg/m 3 ; elemental carbon (n = 79) GM = 7-55 μg/m 3 ; organic carbon (n = 79) GM 11-69 μg/m 3 ; ultrafine particles (n = 17) range = 58-231 x 10 3 particles/cm 3 ; selected particulate phase polycyclic aromatic hydrocarbons (PAHs) (n - 14) range = 6-37 ng/m 3 . In addition, a tracer method based on ultrafine particle measurements was used to estimate the spatial distribution of total carbon and PAHs at the sites monitored. The spatial distribution was found to be reasonably uniform. Major diesel fume aerosol components were, in general, well correlated (r = 0.62-0.97). CO 2 measurements were also made and found to be below the HSE guideline of 1000 p.p.m., with most levels below 600 p.p.m. (Author)

A comparison between atmospheric/humidity and vacuum cyanoacrylate fuming of latent fingermarks.

Science.gov (United States)

Farrugia, Kevin J; Fraser, Joanna; Friel, Lauren; Adams, Duncan; Attard-Montalto, Nicola; Deacon, Paul

2015-12-01

A number of pseudo-operational trials were set up to compare the atmospheric/humidity and vacuum cyanoacrylate fuming processes on plastic carrier bags. The fuming processes were compared using two-step cyanoacrylate fuming with basic yellow 40 (BY40) staining and a one-step fluorescent cyanoacrylate fuming, Lumicyano 4%. Preliminary work using planted fingermarks and split depletions were performed to identify the optimum vacuum fuming conditions. The first pseudo-operational trial compared the different fuming conditions (atmospheric/humidity vs. vacuum) for the two-step process where an additional 50% more marks were detected with the atmospheric/humidity process. None of the marks by the vacuum process could be observed visually; however, a significant number of marks were detected by fluorescence after BY40 staining. The second trial repeated the same work in trial 1 using the one-step cyanoacrylate process, Lumicyano at a concentration of 4%. Trial 2 provided comparable results to trial 1 and all the items were then re-treated with Lumicyano 4% at atmospheric/humidity conditions before dyeing with BY40 to provide the sequences of process A (Lumicyano 4% atmospheric-Lumicyano 4% atmospheric-BY40) and process B (Lumicyano 4% vacuum-Lumicyano 4% atmospheric-BY40). The number of marks (visual and fluorescent) was counted after each treatment with a substantial increase in the number of detected marks in the second and third treatments of the process. The increased detection rate after the double Lumicyano process was unexpected and may have important implications. Trial 3 was performed to investigate whether the amount of cyanoacrylate and/or fuming time had an impact on the results observed in trial 2 whereas trial 4 assessed if the double process using conventional cyanoacrylate, rather than Lumicyano 4%, provided an increased detection rate. Trials 3 and 4 confirmed that doubling the amount of Lumicyano 4% cyanoacrylate and fuming time produced a lower

Response of the mouse lung transcriptome to welding fume: effects of stainless and mild steel fumes on lung gene expression in A/J and C57BL/6J mice

Directory of Open Access Journals (Sweden)

Antonini James M

2010-06-01

Full Text Available Abstract Background Debate exists as to whether welding fume is carcinogenic, but epidemiological evidence suggests that welders are an at risk population for the development of lung cancer. Recently, we found that exposure to welding fume caused an acutely greater and prolonged lung inflammatory response in lung tumor susceptible A/J versus resistant C57BL/6J (B6 mice and a trend for increased tumor incidence after stainless steel (SS fume exposure. Here, our objective was to examine potential strain-dependent differences in the regulation and resolution of the lung inflammatory response induced by carcinogenic (Cr and Ni abundant or non-carcinogenic (iron abundant metal-containing welding fumes at the transcriptome level. Methods Mice were exposed four times by pharyngeal aspiration to 5 mg/kg iron abundant gas metal arc-mild steel (GMA-MS, Cr and Ni abundant GMA-SS fume or vehicle and were euthanized 4 and 16 weeks after the last exposure. Whole lung microarray using Illumina Mouse Ref-8 expression beadchips was done. Results Overall, we found that tumor susceptibility was associated with a more marked transcriptional response to both GMA-MS and -SS welding fumes. Also, Ingenuity Pathway Analysis revealed that gene regulation and expression in the top molecular networks differed between the strains at both time points post-exposure. Interestingly, a common finding between the strains was that GMA-MS fume exposure altered behavioral gene networks. In contrast, GMA-SS fume exposure chronically upregulated chemotactic and immunomodulatory genes such as CCL3, CCL4, CXCL2, and MMP12 in the A/J strain. In the GMA-SS-exposed B6 mouse, genes that initially downregulated cellular movement, hematological system development/function and immune response were involved at both time points post-exposure. However, at 16 weeks, a transcriptional switch to an upregulation for neutrophil chemotactic genes was found and included genes such as S100A8, S100A9 and

Comparison of stainless and mild steel welding fumes in generation of reactive oxygen species

Directory of Open Access Journals (Sweden)

Frazer David

2010-11-01

Full Text Available Abstract Background Welding fumes consist of a wide range of complex metal oxide particles which can be deposited in all regions of the respiratory tract. The welding aerosol is not homogeneous and is generated mostly from the electrode/wire. Over 390,000 welders were reported in the U.S. in 2008 while over 1 million full-time welders were working worldwide. Many health effects are presently under investigation from exposure to welding fumes. Welding fume pulmonary effects have been associated with bronchitis, metal fume fever, cancer and functional changes in the lung. Our investigation focused on the generation of free radicals and reactive oxygen species from stainless and mild steel welding fumes generated by a gas metal arc robotic welder. An inhalation exposure chamber located at NIOSH was used to collect the welding fume particles. Results Our results show that hydroxyl radicals (.OH were generated from reactions with H2O2 and after exposure to cells. Catalase reduced the generation of .OH from exposed cells indicating the involvement of H2O2. The welding fume suspension also showed the ability to cause lipid peroxidation, effect O2 consumption, induce H2O2 generation in cells, and cause DNA damage. Conclusion Increase in oxidative damage observed in the cellular exposures correlated well with .OH generation in size and type of welding fumes, indicating the influence of metal type and transition state on radical production as well as associated damage. Our results demonstrate that both types of welding fumes are able to generate ROS and ROS-related damage over a range of particle sizes; however, the stainless steel fumes consistently showed a significantly higher reactivity and radical generation capacity. The chemical composition of the steel had a significant impact on the ROS generation capacity with the stainless steel containing Cr and Ni causing more damage than the mild steel. Our results suggest that welding fumes may cause acute

Udvikling af informationskompetence i problemorienteret arbejde med brug af digitale værktøjer

DEFF Research Database (Denmark)

Nielsen, Jørgen Lerche; Birch Andreasen, Lars; Jørgensen, Lars

2006-01-01

vejledningsformer. Visionen for projektet er, at arbejdet med at støtte de studerendes udvikling af informationskompetence ikke alene ses som en opgave for biblioteker biblioteker, men som en opgave der skal løses i et tættere integreret samarbejde mellem biblioteker og faglige uddannelsesmiljøer. Pilotprojektet...

Work environments and exposure to hazardous substances in korean tire manufacturing.

Science.gov (United States)

Lee, Naroo; Lee, Byung-Kyu; Jeong, Sijeong; Yi, Gwang Yong; Shin, Jungah

2012-06-01

The purpose of this study is to evaluate the tire manufacturing work environments extensively and to identify workers' exposure to hazardous substances in various work processes. Personal air sampling was conducted to measure polycyclic aromatic hydrocarbons, carbon disulfide, 1,3-butadiene, styrene, methyl isobutyl ketone, methylcyclohexane, formaldehyde, sulfur dioxide, and rubber fume in tire manufacturing plants using the National Institute for Occupational Safety Health Manual of Analytical Methods. Noise, carbon monoxide, and heat stress exposure were evaluated using direct reading instruments. Past concentrations of rubber fume were assessed using regression analysis of total particulate data from 2003 to 2007, after identifying the correlation between the concentration of total particulate and rubber fume. Workers were exposed to rubber fume that exceeded 0.6 mg/m(3), the maximum exposure limit of the UK, in curing and production management processes. Forty-seven percent of workers were exposed to noise levels exceeding 85 dBA. Workers in the production management process were exposed to 28.1℃ (wet bulb globe temperature value, WBGT value) even when the outdoor atmosphere was 2.7℃ (WBGT value). Exposures to other substances were below the limit of detection or under a tenth of the threshold limit values given by the American Conference of Governmental Industrial Hygienists. To better classify exposure groups and to improve work environments, examining closely at rubber fume components and temperature as risk indicators in tire manufacturing is recommended.

Investigations on the tensile strength of high performance concrete incorporating silica fume

International Nuclear Information System (INIS)

Santanu Bhanja; Bratish Sengupta

2005-01-01

Though the literature is rich in reporting on silica fume concrete the technical data on tensile strength is quite limited. The present paper is directed towards developing a better understanding on the isolated contribution of silica fume on the tensile strengths of High Performance Concrete. Extensive experimentation was carried out over water-binder ratios ranging from 0.26 to 0.42 and silica fume binder ratios from 0.0 to 0.3. For all the mixes compressive, flexural and split tensile strengths were determined at 28 days. The results of the present investigation indicate that silica fume incorporation results in significant improvements in the tensile strengths of concrete. It is also observed that the optimum replacement percentage, which led to maximization of strength, is not a constant one but depends on the water- cementitious material ratio of the mix. Compared to split tensile strengths, flexural strengths have exhibited greater percentage gains in strength. Increase in split tensile strength beyond 15% silica fume replacement is almost insignificant whereas sizeable gains in flexural tensile strength have occurred even up to 25% replacements. For the present investigation transgranular failure of concrete was observed which indicate that silica fume incorporation results in significant improvements in the strength of both paste and transition zone. (authors)

Designing, Constructing and Installing a Local Exhaust Ventilation System to Minimize Welders\\' Exposure to Welding Fumes

Directory of Open Access Journals (Sweden)

Sajad Zare

2017-10-01

Full Text Available Background & Aims of the Study: Welder’s exposure to welding fumes can cause occupational diseases. The current study sought to examine exposure to welding fumes among welders who work in the repair shop of Sarcheshmeh Copper Complex and design a local exhaust ventilation system to control exposure to welding fumes. Materials & Methods: This applied analytical study was conducted in the summer of 2016 among welders working in the repair shop of Sarcheshmeh Copper Complex. The study comprised three phases; in the first one, welders’ exposure to welding fumes was assessed at the beginning of the study. After that, a local exhaust ventilation system was designed and installed in the aforementioned repair shop. In the final stage, welders’ exposure to welding fumes was assessed again after installation of the ventilation system. The procedure recommended by NIOSH (method number 7300 was used for individual sampling of welders. Results: Based on the obtained findings, before installing the ventilation system, welding technicians were exposed to 0.3 mg/m3 of copper fumes and 0.04 mg/m3 of chromium fumes. Journeyman welders were also exposed to 2.16 mg/m3 of manganese fumes, while stellar welders were exposed to 6.9 mg/m3 of iron fumes. In the light of these measurements, a local exhaust ventilation system was designed and installed. Subsequently, measurement of exposure to welding fumes showed a significant reduction. That is, welding technicians were exposed to 0.17 mg/m3 and 0.015 mg/m3 of copper and chromium fumes respectively. Additionally, journeyman welders were exposed to 0.86 mg/m3 of manganese fumes, whereas stellar welders were exposed to 4.3 mg/m3 of iron fumes. Conclusions: A comparison of standard limits of exposure to welding fumes and the results obtained from measurements in sampling stations before and after the installation of the local exhaust ventilation system reveals that this controlling measure was very effective in the

Danish Investigations on Silica Fume Concretes at Elevated Temperatures

DEFF Research Database (Denmark)

Hertz, Kristian Dahl

1992-01-01

Describes fire tests in which the increased risk of explosive spalling of concrete densified by silica fume was first discovered. Further results are discussed from tests to define appropriate limits of silica fume content and to develop a new concrete for slender column units. Observations are m...... are made about circumstances under which superplasticizing additives in concrete gave rise to the development of toxic gases....

Peripheral neuropathy following intentional inhalation of naphtha fumes.

Science.gov (United States)

Tenenbein, M; deGroot, W; Rajani, K R

1984-01-01

Two adolescent native Canadians who presented with peripheral neuropathy secondary to the abuse of volatile hydrocarbons are described. They were initially thought to have been sniffing leaded gasoline fumes, but public health investigation revealed that they had been sniffing naphtha fumes. Naphtha contains a significant amount of n-hexane, a known inducer of neuropathy. Nerve conduction studies and nerve biopsy confirmed the diagnosis of naphtha abuse. These cases emphasize the need to specifically identify the formulation of hydrocarbons being abused. PMID:6093978

Investigation of durability of silica fume concretes in coastal structures within tidal zone

International Nuclear Information System (INIS)

Ganjian, E.; Sadeghi Pouya, H.

2003-01-01

In recent decade use of silica fume has been become greater in coastal concrete structures in the persona gulf, to increase durability of those establishments. In this research the durability of cement passers and concrete cubes with use of 7 and 10 percent of silica fume as a cement replacement have been investigated in three curing conditions (fresh water, coast of sea and simulation bonds) by measuring compressive strengths and capillary absorption. Silica fume specimens under wetting and drying condition showed more strength loss after 180 days compare to samples without silica fume or cured in the fresh water. In addition the greater silica fume amount in specimens cured within tidal zone and under wetting and drying simulation, the more water absorption by capillary. According to the results, good correspondence between simulated condition and real site exposure was obtained

Effects of Calcined clay minerals and Silica fume on the compressive strength of concrete

Directory of Open Access Journals (Sweden)

Abolfazl Soltani

2017-05-01

Full Text Available Pozzolanic materials are well known as potential replacements for cement manufacturing in order to increase compressive strength and improve durability of concrete in different environments and leading to save energy particularly reducing global warming effect. The present study reveals the effect of calcined clay minerals as natural pozzolanic material, separately and in combination with and without silica fume. To achieve this aim, 15 mixed designs with a constant water to cementitious ratio of  0.38 is made. In six mixed designs only metakaolin, zeolite or silica fume  and in eight other designs metakaolin and silica fume or zeolite and silica fume have been combined. Mixes containing metakaolin or zeolite with ratio of 10 or 20 percent and silica fume with 7 or 10 percent show significant increasing in compressive strength and improving durability, being valuable replacement for cement (in percentages. In particular, the best practice is attributed to the age of 28 days for compressive strength the replacement of the composition is 10% zeolite with 7% of silica fume and for electrical resistance the replacement of the composition is 10% zeolite with 7% of silica fume.

78 FR 44625 - Proposed Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment...

Science.gov (United States)

2013-07-24

... DEPARTMENT OF VETERANS AFFAIRS Proposed Information Collection (Open Burn Pit Registry Airborne... to ``OMB Control No. 2900--NEW, Open Burn Pit Registry Airborne Hazard Self-Assessment Questionnaire... health effects of service members' exposure to toxic airborne chemicals and fumes caused by open burn...

Effects of densified silica fume on microstructure and compressive strength of blended cement pastes

International Nuclear Information System (INIS)

Ji Yajun; Cahyadi, Jong Herman

2003-01-01

Some experimental investigations on the microstructure and compressive strength development of silica fume blended cement pastes are presented in this paper. The silica fume replacement varies from 0% to 20% by weight and the water/binder ratio (w/b) is 0.4. The pore structure by mercury intrusion porosimetry (MIP), the micromorphology by scanning electron microscopy (SEM) and the compressive strength at 3, 7, 14, 28, 56 and 90 days have been studied. The test results indicate that the improvements on both microstructure and mechanical properties of hardened cement pastes by silica fume replacement are not effective due to the agglomeration of silica fume particles. The unreacted silica fume remained in cement pastes, the threshold diameter was not reduced and the increase in compressive strength was insignificant up to 28 days. It is suggested that the proper measures should be taken to disperse silica fume agglomeration to make it more effective on improving the properties of materials

Influence of silica fume and fly ash on hydration, microstructure and strength of cement based mixtures

Energy Technology Data Exchange (ETDEWEB)

Weng, Kaimao

1992-10-01

The influence of fly ash and silica fume on the hydration, microstructure and strength of cement-based mixtures was investigated. A literature review of the hydration processes, compressive strength development, and microstructure of Portland cement is presented, followed by description of materials and specimens preparation and experimental methodology. It was found that silica fume retards cement hydration at low water/concrete ratios. It reduces calcium hydroxide significantly and increases the amount of hydrates at early ages. Fly ash retards hydration more significantly at high water/concrete ratios than at low ratios. The combination of silica fume and fly ash further retards hydration at one day. Silica fume dominates the reaction with calcium hydroxide. Silica fume significantly increases early strength of mortars and concrete, while fly ash reduces early strength. Silica fume can substantially increase strength of fly ash mortar and concrete after 7 days. Silica fume refines pores in the range 100-500 A, while fly ash mortars exhibit gradual pore refinement as hydration proceeds. Silica fume dominates the pore refinement if used with fly ash. 89 refs., 74 figs., 16 tabs.

Influence of polyolefin fibers on the engineering properties of cement-based composites containing silica fume

International Nuclear Information System (INIS)

Han, Ta-Yuan; Lin, Wei-Ting; Cheng, An; Huang, Ran; Huang, Chin-Cheng

2012-01-01

Highlights: ► Experimental study is focus on the engineering properties of cement-based composites. ► Different mixes containing fiber and silica fume proportions have been tested. ► The influence of different mixes on the engineering properties has been discussed. ► The properties are included strength, ductility, permeability and microstructure. -- Abstract: This study evaluated the mechanical properties of cement-based composites produced with added polyolefin fibers and silica fume. Material variables included the water-cementitious ratio, the dosage of silica fume, and the length and dosage of polyolefin fiber. Researchers conducted tests on compressive strength, splitting tensile strength, direct tensile strength, resistivity, rapid chloride penetration, and initial surface absorption, and performed microscopic observation. Test results indicate that the specimens containing silica fume have higher compressive strength than the control and specimen made with fibers. The specimens with polyolefin fiber and silica fume have considerably higher tensile strength and ductility than the control and specimens made with silica fume. The specimens containing silica fume and polyolefin fiber demonstrated better resistance to chloride penetration than composites with polyolefin fiber or silica fume. For a given volume fraction, short polyolefin fiber performs better than its long counterpart in improving the properties of concrete. Specimens containing silica fume demonstrated a significant increase in resistivity and decrease in the total charge passed and absorption. Scanning electron microscopy illustrates that the polyolefin fiber acts to arrest the propagation of internal cracks.

30 CFR 70.305 - Respiratory equipment; gas, dusts, fumes, or mists.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Respiratory equipment; gas, dusts, fumes, or... LABOR COAL MINE SAFETY AND HEALTH MANDATORY HEALTH STANDARDS-UNDERGROUND COAL MINES Respiratory Equipment § 70.305 Respiratory equipment; gas, dusts, fumes, or mists. Respiratory equipment approved by...

Reaction products of densified silica fume agglomerates in concrete

International Nuclear Information System (INIS)

Diamond, Sidney; Sahu, Sadananda; Thaulow, Niels

2004-01-01

Most silica fume currently used in concrete is in the dry densified form and consists of agglomerates of sizes between 10 μm and several millimeters. Many of these agglomerates may break down only partially in normal concrete mixing. Examination of various mature silica-fume-bearing concretes using backscatter mode scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis shows that such agglomerates have reacted in situ and given rise to recognizable types of reaction products filling the space within the original outline of the agglomerate. One type is 'quiescent', and usually shows no evidence of volume instability. EDX spectra indicate that the product formed within such grains is C-S-H of very low Ca/Si ratio, with modest alkali contents. Other silica fume agglomerates may undergo a distinct alkali-silica-type reaction (ASR), with the reaction product found within the original outline of the agglomerate having significantly less calcium and usually much higher alkali contents than the quiescent type. Such reacted agglomerates show evidence of local expansion, shrinkage cracking (on drying), and other features common to ASR. Both types may be found within the same concrete, sometimes in close proximity. It further appears that exposure to seawater may convert previously formed reaction products of silica fume agglomerates to magnesium silicate hydrates

Modifying welding process parameters can reduce the neurotoxic potential of manganese-containing welding fumes.

Science.gov (United States)

Sriram, Krishnan; Lin, Gary X; Jefferson, Amy M; Stone, Samuel; Afshari, Aliakbar; Keane, Michael J; McKinney, Walter; Jackson, Mark; Chen, Bean T; Schwegler-Berry, Diane; Cumpston, Amy; Cumpston, Jared L; Roberts, Jenny R; Frazer, David G; Antonini, James M

2015-02-03

Welding fumes (WF) are a complex mixture of toxic metals and gases, inhalation of which can lead to adverse health effects among welders. The presence of manganese (Mn) in welding electrodes is cause for concern about the potential development of Parkinson's disease (PD)-like neurological disorder. Consequently, from an occupational safety perspective, there is a critical need to prevent adverse exposures to WF. As the fume generation rate and physicochemical characteristics of welding aerosols are influenced by welding process parameters like voltage, current or shielding gas, we sought to determine if changing such parameters can alter the fume profile and consequently its neurotoxic potential. Specifically, we evaluated the influence of voltage on fume composition and neurotoxic outcome. Rats were exposed by whole-body inhalation (40 mg/m(3); 3h/day × 5 d/week × 2 weeks) to fumes generated by gas-metal arc welding using stainless steel electrodes (GMA-SS) at standard/regular voltage (25 V; RVSS) or high voltage (30 V; HVSS). Fumes generated under these conditions exhibited similar particulate morphology, appearing as chain-like aggregates; however, HVSS fumes comprised of a larger fraction of ultrafine particulates that are generally considered to be more toxic than their fine counterparts. Paradoxically, exposure to HVSS fumes did not elicit dopaminergic neurotoxicity, as monitored by the expression of dopaminergic and PD-related markers. We show that the lack of neurotoxicity is due to reduced solubility of Mn in HVSS fumes. Our findings show promise for process control procedures in developing prevention strategies for Mn-related neurotoxicity during welding; however, it warrants additional investigations to determine if such modifications can be suitably adapted at the workplace to avert or reduce adverse neurological risks. Published by Elsevier Ireland Ltd.

Modifying welding process parameters can reduce the neurotoxic potential of manganese-containing welding fumes

International Nuclear Information System (INIS)

Sriram, Krishnan; Lin, Gary X.; Jefferson, Amy M.; Stone, Samuel; Afshari, Aliakbar; Keane, Michael J.; McKinney, Walter; Jackson, Mark; Chen, Bean T.; Schwegler-Berry, Diane; Cumpston, Amy; Cumpston, Jared L.; Roberts, Jenny R.; Frazer, David G.; Antonini, James M.

2015-01-01

Welding fumes (WF) are a complex mixture of toxic metals and gases, inhalation of which can lead to adverse health effects among welders. The presence of manganese (Mn) in welding electrodes is cause for concern about the potential development of Parkinson’s disease (PD)-like neurological disorder. Consequently, from an occupational safety perspective, there is a critical need to prevent adverse exposures to WF. As the fume generation rate and physicochemical characteristics of welding aerosols are influenced by welding process parameters like voltage, current or shielding gas, we sought to determine if changing such parameters can alter the fume profile and consequently its neurotoxic potential. Specifically, we evaluated the influence of voltage on fume composition and neurotoxic outcome. Rats were exposed by whole-body inhalation (40 mg/m 3 ; 3 h/day × 5 d/week × 2 weeks) to fumes generated by gas–metal arc welding using stainless steel electrodes (GMA-SS) at standard/regular voltage (25 V; RVSS) or high voltage (30 V; HVSS). Fumes generated under these conditions exhibited similar particulate morphology, appearing as chain-like aggregates; however, HVSS fumes comprised of a larger fraction of ultrafine particulates that are generally considered to be more toxic than their fine counterparts. Paradoxically, exposure to HVSS fumes did not elicit dopaminergic neurotoxicity, as monitored by the expression of dopaminergic and PD-related markers. We show that the lack of neurotoxicity is due to reduced solubility of Mn in HVSS fumes. Our findings show promise for process control procedures in developing prevention strategies for Mn-related neurotoxicity during welding; however, it warrants additional investigations to determine if such modifications can be suitably adapted at the workplace to avert or reduce adverse neurological risks

Risk of ischemic heart disease following occupational exposure to welding fumes

DEFF Research Database (Denmark)

Mocevic, Emina; Kristiansen, Pernille; Bonde, Jens Peter

2015-01-01

PURPOSE: Air pollution has been linked to an increased risk of ischemic heart disease (IHD), but less is known about occupational exposure to welding fumes and the risk of IHD. The objective of this paper was to review the epidemiological evidence on causal links between welding fume exposure...

Anatomical indications of fume resistance in certain woody plants

Energy Technology Data Exchange (ETDEWEB)

Ninova, D.

1970-01-01

An attempt is made to describe studies on seven species of fruit and forest trees close to or far from a Bulgarian factory emitting fumes containing S. The most resistant species (Quercus borealis, Gleditsia triacanthos, Morus alba) had the smallest stomata and the greatest number of stomata per unit leaf area. Changes observed in leaf anatomy as a result of exposure to the fumes were: decreased leaf aeration, elongated palisade cells, thicker cuticles, and more stomata.

Hexavalent chromium content in stainless steel welding fumes is dependent on the welding process and shield gas type.

Science.gov (United States)

Keane, Michael; Stone, Samuel; Chen, Bean; Slaven, James; Schwegler-Berry, Diane; Antonini, James

2009-02-01

Occupational exposure to welding fumes is a known health hazard. To isolate elements in stainless steel welding fumes with high potential for adverse health outcomes, fumes were generated using a robotic gas metal arc system, using four shield gases of varying oxygen content. The objective was to measure Cr(VI) concentrations in a broad spectrum of gas metal arc welding processes, and identify processes of exceptionally high or low Cr(VI) content. The gases used were 95% Ar/5% O(2), 98% Ar/2% O(2), 95% Ar/5%CO(2), and 75% He/25% Ar. The welder was operated in axial spray mode (Ar/O(2), Ar/CO(2)), short-circuit (SC) mode (Ar/CO(2) low voltage and He/Ar), and pulsed axial-spray mode (98% Ar/2% O(2)). Results indicate large differences in Cr(VI) in the fumes, with Ar/O(2) (Pulsed)>Ar/O(2)>Ar/CO(2)>Ar/CO(2) (SC)>He/Ar; values were 3000+/-300, 2800+/-85, 2600+/-120, 1400+/-190, and 320+/-290 ppm respectively (means +/- standard errors for 2 runs and 3 replicates per run). Respective rates of Cr(VI) generation were 1.5, 3.2, 4.4, 1.3, and 0.46 microg/min; generation rates were also calculated in terms of microg Cr(VI) per metre of wire used. The generation rates of Cr(VI) increased with increasing O(3) concentrations. Particle size measurements indicated similar distributions, but somewhat higher >0.6 microm fractions for the short-circuit mode samples. Fumes were also sampled into 2 selected size ranges, a microspatter fraction (>or=0.6 microm) and a fine (welding type and shield gas type, and this presents an opportunity to tailor welding practices to lessen Cr(VI) exposures in workplaces by selecting low Cr(VI)-generating processes. Short-circuit processes generated less Cr(VI) than axial-spray methods, and inert gas shielding gave lower Cr(VI) content than shielding with active gases. A short circuit He/Ar shielded process and a pulsed axial spray Ar/O(2) process were both identified as having substantially lower Cr(VI) generation rates per unit of wire used relative

Improvement of RVNRL film properties by adding fumed silica and hydroxy apatite

Directory of Open Access Journals (Sweden)

Adul Thiangchanya

2003-01-01

Full Text Available The effect of adding fumed silica and hydroxy apatite to Radiation Vulcanized Natural Rubber Latex (RVNRL for improving tear strength, aging properties, degradability and water-soluble protein content of rubber films has been investigated. The addition of fumed silica and hydroxy apatite in RVNRL improves tear strength and aging properties of rubber films, whereas tensile strength and degradability of rubber films were unchanged during storage at room temperature. The water-soluble protein content in rubber films was reduced by immobilization of the fumed silica and hydroxy apatite and enhanced by addition of ZnO. This may reduce allergy problems of natural rubber latex products caused by water-soluble protein. The MST of the RVNRL with fumed silica and hydroxy apatite indicated that the latex must be used within two months after mixing because of its stability.

Hepatotoxicity and genotoxicity of gasoline fumes in albino rats

Directory of Open Access Journals (Sweden)

Folarin O. Owagboriaye

2017-09-01

Full Text Available Toxic effects of gasoline fumes have been reported, but evidence of its hepatotoxicity and genotoxicity are rare. Therefore, this study assesses hepatotoxicity and genotoxicity of gasoline fumes on forty Albino rats randomly assigned to five experimental treatments (T with eight rats per treatment (T1, T2, T3, T4 and T5. T1(Control was housed in a section of experimental animal house free from gasoline fumes while T2, T3, T4 and T5 were exposed to gasoline fumes in exposure chambers for one, three, five and nine hours daily respectively for twelve weeks. Serum alanine aminotransferase (ALT, aspartate aminotransferase (AST, alkaline phosphatase (ALP and histopathological examination of the liver tissues were used as diagnostic markers to assess liver dysfunction. Genotoxicity test was conducted on the lung tissues using randomly amplified polymorphic DNA fingerprinting polymerase chain reaction (RAPD PCR technique. Significant increase (p < 0.05 in the level of ALT, AST and ALP for T2, T3, T4 and T5 compared to T1 were recorded. Photomicrograph examination of the liver sections of T1 showed hepatic tissue with normal liver cell architecture while that of T2, T3, T4 and T5 revealed degenerative changes in the ultrastructural integrity of the hepatic cells. Genotoxicity test revealed DNA bands at a reducing intensity from T1 to T5. Dendrogram showed DNA damage in the lungs of T3, T4 and T5 were closely similar and the genotoxic impact was more in T3. Frequent exposure to gasoline fumes was observed to induce hepatoxicity and genotoxicity, hence impairing the normal liver function and gene structure.

Characterisation of fume from hyperbaric welding operations

Energy Technology Data Exchange (ETDEWEB)

Ross, John A S; Semple, Sean [Environmental and Occupational Medicine, University of Aberdeen (United Kingdom); Duffin, Rodger [ELEGI Colt Laboratory, University of Edinburgh (United Kingdom); Kelly, Frank [Lung Biology Group, Kings College, University of London (United Kingdom); Seldmann, Joerg; Raab, Andrea, E-mail: j.a.ross@abdn.ac.u [Trace Element Speciation Laboratory, University of Aberdeen (United Kingdom)

2009-02-01

We report preliminary work characterising dust from hyperbaric welding trials carried out at increased pressure in a helium and oxygen atmosphere. Particle size and concentration were measured during welding. Samples for quartz and metal analysis and toxicity assessment were taken from a filter in the local fume extraction system. The residue of dust after metal extraction by nitric acid in hydrogen peroxide predominantly a non-metallic white powder assumed to be dust from welding rod coatings and thermal insulation material. Metallic analysis showed predominantly calcium, from the welding rod coating, and period 4 transition metals such as iron, manganese, magnesium and titanium (inductively coupled mass spectrometry, Agilent 7500c). The presence of zirconium indicated a contribution from grinding. The fume was nanoparticulate in nature with a mean particle diameter of 20-30 nm (MSI Inc WPS 1000XP). It showed an intermediate level of oxidative potential regarding the low-molecular weight respiratory tract lining fluid antioxidants ascorbate and glutathione and caused release of the inflammatory marker IL-8 in a human lung A 549 epithelial cell culture with no indication of cytotoxicity. The study findings have strong implications for the measurement techniques needed to assess fume exposure in hyperbaric welding and the provision of respiratory protection.

Online lektiehjælp – Udvikling af en vejledningsdidaktik med pædagogisk designforskning som metode

Directory of Open Access Journals (Sweden)

Jens Jørgen Hansen

2016-05-01

Full Text Available Lektievejledning er en pædagogisk praksis i rivende udvikling med fokus på at støtte elever i at forstå og håndtere udfordringer i deres lektiearbejde. Lektievejledning er på den politiske dagsorden i skole og ungdomsuddannelser og tilbydes både internt af uddannelsesinstitutionerne samt af private og offentlige aktører. Men lektievejledning er ikke etableret som et teoretisk felt eller som en særlig vejledningskompetence. Der er således behov for at begrebsliggøre og udvikle teori om, hvad lektievejledning er, og hvordan vejledningsformen didaktisk kan håndteres. Mere konkret er ud-fordringen at udvikle et nuanceret fagsprog samt en modellering af feltet til forklaring af lektievejledningens komplekse praksis med det mål at udvikle og kvalificere lektievejledning som pædagogisk teori og pædagogisk prak-sis. Denne artikel præsenterer resultatet af et forskningsprojekt, hvis mål er at udvikle en vejledningsdidaktik, herunder metoder, modeller og materialer for lektievejledning i regi af Lektier Online. Lektier Online er en organisation ved Statsbiblioteket i Århus, der tilbyder en online lektiecafe, hvor bl.a. gymnasie-elever kan få hjælp af frivillige universitetsstuderende. Dette didaktiske de-sign er et eksempel på, hvordan digitalisering og ny teknologi er en katalysator for udvikling af nye innovative læringsmiljøer og læringstilbud, der åbner fleksible og stedsuafhængige rum for læring, giver mulighed for samspil med aktører uden for skolens formelle rammer, og som er båret af integration af digitale teknologier i læringssituationen. Artiklen beskriver forskningsproces-sen med at indkredse en vejledningsdidaktik for lektiehjælp samt udviklingen, konceptualiseringen, afprøvningen og evalueringen af en række vejlednings-modeller på grundlag af forskningsmetoden Pædagogisk designforskning og dens tradition for brugerdreven innovation. Artiklen beskriver for det første resultatet af forskningsprocessen i form

Short term exposure to cooking fumes and pulmonary function

OpenAIRE

Qvenild Torgunn; Svendsen Kristin; Svedahl Sindre; Sjaastad Ann; Hilt Bjørn

2009-01-01

Abstract Background Exposure to cooking fumes may have different deleterious effects on the respiratory system. The aim of this study was to look at possible effects from inhalation of cooking fumes on pulmonary function. Methods Two groups of 12 healthy volunteers (A and B) stayed in a model kitchen for two and four hours respectively, and were monitored with spirometry four times during twenty four hours, on one occasion without any exposure, and on another with exposure to controlled level...

Formulation and characterization of date palm fibers mortar by addition of silica fume

Science.gov (United States)

Mokhtari, A.; Kriker, A.; Ouaggad, H.; Merad, N.

2018-05-01

This paper presents the results of experimental investigations of the formulated and characterization of date palm fibers mortar by addition of silica fume. The use of addition mineral is widely used in the production of cements through the world. The objective of this work is to bring our contribution to the recovery of local resources in the occurrence vegetable fibers of date palm to weak cost and from renewable source and integrate it in the filled of building. Date palm fiber are from Ouargla town in south of Algeria. Different mortar mixtures were prepared in which the cement was substitute by 10% of silica fume. The mechanical characteristics (compressive and flexural strength) of date palm fibers mortar by treatment of the matrix by the adding of silica fume were examined. The results obtained have shown that the mortar workability as well as the compressive and flexural strength decreases with increasing the silica fume replacement. The results showed that the use of silica fume enabled to evaluate the flexural strength. However, another treatment of fibers and matrix will be recommended for Improved the characteristics.

The mechanism of cesium immobilization in densified silica-fume blended cement pastes

International Nuclear Information System (INIS)

Bar-Nes, G.; Katz, A.; Peled, Y.; Zeiri, Y.

2008-01-01

The role of silica-fume agglomerates, found in densified silica-fume (DSF) pastes, in the immobilization mechanism of Cs ions was studied. Samples of cementitious pastes containing two different forms of silica fume - DSF and raw silica fume (RSF) - were prepared. Leaching experiments showed that both additives reduced the leachability of the metal ion, but the effect of the DSF paste was much stronger. Scanning Electron Microscopy, together with Differential Thermal Analysis, proved that no agglomerated particles were present in the RSF pastes and that the extent of pozzolanic reactivity was higher. We therefore believe that unreacted silica within the DSF agglomerates adsorbs Cs ions and consequently increases their immobilization. Furthermore, this work suggests that during the pozzolanic reaction, a hydrated rim develops around the agglomerate that acts as an additional diffusion barrier for the Cs ions, resulting in an increased efficiency of Cs immobilization

42 CFR 84.1141 - Isoamyl acetate tightness test; dust, fume, and mist respirators designed for respiratory...

Science.gov (United States)

2010-10-01

... mist respirators designed for respiratory protection against fumes of various metals having an air... HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist....1141 Isoamyl acetate tightness test; dust, fume, and mist respirators designed for respiratory...

Crosslinkable fumed silica-based nanocomposite electrolytes for rechargeable lithium batteries

Energy Technology Data Exchange (ETDEWEB)

Li, Yangxing; Yerian, Jeffrey A.; Khan, Saad A.; Fedkiw, Peter S. [Department of Chemical & amp; Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695-7905 (United States)

2006-10-27

Electrochemical and rheological properties are reported of composite polymer electrolytes (CPEs) consisting of dual-functionalized fumed silica with methacrylate and octyl groups+low-molecular weight poly(ethylene glycol) dimethyl ether (PEGdm)+lithium bis(trifluoromethanesulfonyl)imide (LiTFSI, lithium imide)+butyl methacrylate (BMA). The role of butyl methacrylate, which aids in formation of a crosslinked network by tethering adjacent fumed silica particles, on rheology and electrochemistry is examined together with the effects of fumed silica surface group, fumed silica weight percent, salt concentration, and solvent molecular weight. Chemical crosslinking of the fumed silica with 20% BMA shows a substantial increase in the elastic modulus of the system and a transition from a liquid-like/flocculated state to an elastic network. In contrast, no change in lithium transference number and only a modest decrease (factor of 2) on conductivity of the CPE are observed, indicating that a crosslinked silica network has minimal effect on the mechanism of ionic transport. These trends suggest that the chemical crosslinks occur on a microscopic scale, as opposed to a molecular scale, between adjacent silica particles and therefore do not impede the segmental mobility of the PEGdm. The relative proportion of the methacrylate and octyl groups on the silica surface displays a nominal effect on both rheology and conductivity following crosslinking although the pre-cure rheology is a function of the surface groups. Chemical crosslinked nanocomposite polymer electrolytes offer significant higher elastic modulus and yield stress than the physical nanocomposite counterpart with a small/negligible penalty of transport properties. The crosslinked CPEs exhibit good interfacial stability with lithium metal at open circuit, however, they perform poorly in cycling of lithium-lithium cells. (author)

Internationale policies og nationale handleplaner for sundhedsfremme og uddannelse for bæredygtig udvikling i skolen

DEFF Research Database (Denmark)

Madsen, Katrine Dahl; Nordin, Lone Lindegard; Simovska, Venka

Målet med denne dokumentanalyse er at klarlægge de internationale og nationale politiske rammer, der er sat for arbejdet med sundhedsfremme og bæredygtig udvikling i grundskolen i Danmark i dag. Hensigten er at undersøge, hvor begreberne kommer fra, hvad skolerne er forpligtede på, fællestræk og ...

Exposure to inhalable, respirable, and ultrafine particles in welding fume.

Science.gov (United States)

Lehnert, Martin; Pesch, Beate; Lotz, Anne; Pelzer, Johannes; Kendzia, Benjamin; Gawrych, Katarzyna; Heinze, Evelyn; Van Gelder, Rainer; Punkenburg, Ewald; Weiss, Tobias; Mattenklott, Markus; Hahn, Jens-Uwe; Möhlmann, Carsten; Berges, Markus; Hartwig, Andrea; Brüning, Thomas

2012-07-01

This investigation aims to explore determinants of exposure to particle size-specific welding fume. Area sampling of ultrafine particles (UFP) was performed at 33 worksites in parallel with the collection of respirable particles. Personal sampling of respirable and inhalable particles was carried out in the breathing zone of 241 welders. Median mass concentrations were 2.48 mg m(-3) for inhalable and 1.29 mg m(-3) for respirable particles when excluding 26 users of powered air-purifying respirators (PAPRs). Mass concentrations were highest when flux-cored arc welding (FCAW) with gas was applied (median of inhalable particles: 11.6 mg m(-3)). Measurements of particles were frequently below the limit of detection (LOD), especially inside PAPRs or during tungsten inert gas welding (TIG). However, TIG generated a high number of small particles, including UFP. We imputed measurements welding fume. Concentrations were mainly predicted by the welding process and were significantly higher when local exhaust ventilation (LEV) was inefficient or when welding was performed in confined spaces. Substitution of high-emission techniques like FCAW, efficient LEV, and using PAPRs where applicable can reduce exposure to welding fume. However, harmonizing the different exposure metrics for UFP (as particle counts) and for the respirable or inhalable fraction of the welding fume (expressed as their mass) remains challenging.

Radon exhalation rates of concrete modified with fly ash and silica fumes

International Nuclear Information System (INIS)

Amit Kumar; Chauhan, R.P.; Mehta, Vimal; Kant, K.

2013-01-01

The radiological impact of the environmental gas radon to the health of general public is of concern since many decades. Cement used for the construction blended with fly ash and silica fumes is recommended by Government in order to avoid the soil and environmental pollution. But these addition step-up the Indoor radon level in the dwelling due to radioactivity contents. The exhalation of radon from concrete blended with silica fumes and fly ash depends upon addition level, porosity, moisture and radioactivity content. In order to optimize the level of substitution of silica fumes and fly ash, measurements of radon exhalation rates from the concrete blended with different proportions of fly ash and silica fumes was carried out using active scintillation radon monitor. The effect of porosity, moisture, back diffusion and radioactivity content of the concrete on exhalation rates is studied. The measured exhalation rates were extrapolated for indoor radon concentration and effective dose equivalent using ICRP, 1987 recommendations. (author)

Alterations in welding process voltage affect the generation of ultrafine particles, fume composition, and pulmonary toxicity.

Science.gov (United States)

Antonini, James M; Keane, Michael; Chen, Bean T; Stone, Samuel; Roberts, Jenny R; Schwegler-Berry, Diane; Andrews, Ronnee N; Frazer, David G; Sriram, Krishnan

2011-12-01

The goal was to determine if increasing welding voltage changes the physico-chemical properties of the fume and influences lung responses. Rats inhaled 40 mg/m³ (3 h/day × 3 days) of stainless steel (SS) welding fume generated at a standard voltage setting of 25 V (regular SS) or at a higher voltage (high voltage SS) of 30 V. Particle morphology, size and composition were characterized. Bronchoalveolar lavage was performed at different times after exposures to assess lung injury. Fumes collected from either of the welding conditions appeared as chain-like agglomerates of nanometer-sized primary particles. High voltage SS welding produced a greater number of ultrafine-sized particles. Fume generated by high voltage SS welding was higher in manganese. Pulmonary toxicity was more substantial and persisted longer after exposure to the regular SS fume. In summary, a modest raise in welding voltage affected fume size and elemental composition and altered the temporal lung toxicity profile.

deFUME: Dynamic exploration of functional metagenomic sequencing data

DEFF Research Database (Denmark)

van der Helm, Eric; Geertz-Hansen, Henrik Marcus; Genee, Hans Jasper

2015-01-01

is time consuming and constitutes a major bottleneck for experimental researchers in the field. Here we present the deFUME web server, an easy-to-use web-based interface for processing, annotation and visualization of functional metagenomics sequencing data, tailored to meet the requirements of non......-bioinformaticians. The web-server integrates multiple analysis steps into one single workflow: read assembly, open reading frame prediction, and annotation with BLAST, InterPro and GO classifiers. Analysis results are visualized in an online dynamic web-interface. The deFUME webserver provides a fast track from raw sequence...

EU er på vej mod at udvikle og implementere europæiske regnskabsstandarder indenfor den offentlige sektor

DEFF Research Database (Denmark)

Pontoppidan, Caroline Aggestam

2015-01-01

I maj 2013 var Europa-Kommisionen og Eurostat vært for en konference med formålet at forhandle om den fremtidige udvikling af harmoniserede offentlige regnskabsstandarder ('European Public Sector Accounting Standards' EPSAS) som skal anvendes af alle medlemslande i den Europæiske Union...

Determining the Compressive, Flexural and Splitting Tensile Strength of Silica Fume Reinforced Lightweight Foamed Concrete

Directory of Open Access Journals (Sweden)

Mydin M.A.O.

2014-01-01

Full Text Available This study investigated the performance of the properties of foamed concrete in replacing volumes of cement of 10%, 15% and 20% by weight. A control unit of foamed concrete mixture made with ordinary Portland cement (OPC and 10%, 15% and 20% silica fume was prepared. Three mechanical property parameters were studied such as compressive strength, flexural strength and splitting tensile of foamed concrete with different percentages of silica fume. Silica fume is commonly used to increase the mechanical properties of concrete materials and it is also chosen due to certain economic reasons. The foamed concrete used in this study was cured at a relative humidity of 70% and a temperature of ±28°C. The improvement of mechanical properties was due to a significant densification in the microstructure of the cement paste matrix in the presence of silica fume hybrid supplementary binder as observed from micrographs obtained in the study. The overall results showed that there is a potential to utilize silica fume in foamed concrete, as there was a noticeable enhancement of thermal and mechanical properties with the addition of silica fume.

Highly Efficient Fumed Silica Nanoparticles for Peptide Bond Formation: Converting Alanine to Alanine Anhydride.

Science.gov (United States)

Guo, Chengchen; Jordan, Jacob S; Yarger, Jeffery L; Holland, Gregory P

2017-05-24

In this work, thermal condensation of alanine adsorbed on fumed silica nanoparticles is investigated using thermal analysis and multiple spectroscopic techniques, including infrared (IR), Raman, and nuclear magnetic resonance (NMR) spectroscopies. Thermal analysis shows that adsorbed alanine can undergo thermal condensation, forming peptide bonds within a short time period and at a lower temperature (∼170 °C) on fumed silica nanoparticle surfaces than that in bulk (∼210 °C). Spectroscopic results further show that alanine is converted to alanine anhydride with a yield of 98.8% during thermal condensation. After comparing peptide formation on solution-derived colloidal silica nanoparticles, it is found that fumed silica nanoparticles show much better efficiency and selectivity than solution-derived colloidal silica nanoparticles for synthesizing alanine anhydride. Furthermore, Raman spectroscopy provides evidence that the high efficiency for fumed silica nanoparticles is likely related to their unique surface features: the intrinsic high population of strained ring structures present at the surface. This work indicates the great potential of fumed silica nanoparticles in synthesizing peptides with high efficiency and selectivity.

Pemanfaatan Mikrobakteri Terhadap Beton Mutu Tinggi dengan Tambahan Silica Fume

Directory of Open Access Journals (Sweden)

Azwar Annas

2016-04-01

Full Text Available Beton mutu tinggi adalah beton yang kuat tekan tinggi sekitar 50 MPa – 100 MPa. Untuk meningkatkan kuat tekan, material pozollan seperti silica fume dan flyash biasanya digunakan untuk mengganti material beton Dalam laporan ini, beton mutu tinggi dengan silica fume sebagai pengganti semen dipelajari. Kadar silica fume yang digunakan adalah 0%, 5%, 7,5% dan 10%. Selain itu pengaruh dari mikrobakteri juga dipelajari. Faktor water per binder yang dipakai adalah 25% dari berat binder, dan untuk membuat workabilitynya bagus maka digunakan superplasticizer. Kadar superplasticizer yang digunakan dicari lewat trial pengujian di laboratorium. Pengujian yang dilakukan pada umur 1, 3, 7, 14, 21, 28 adalah uji tekan pasta, mortar dan beton, selain itu pada benda uji beton umur 28 hari akan dilakukan uji split beton dan uji porositas. Dari hasil penelitian didapatkan kuat tekan beton tertinggi pada umur 28 hari (B7,5M adalah 69,71 MPa, sedangkan variasi silica fume yang paling optimum ada pada kadar 7,5%. Penambahan mikrobakteri tidak berpengaruh pada berat volume beton tetapi berpengaruh pada kuat tekan beton tersebut. Dengan penambahan mikrobakteri maka kuat tekan beton meningkat sebesar ± 30%. Sedangkan porositas total dan porositas tertutup yang terjadi pada beton semakin kecil, ini dibuktikan dengan hasil SEM terlihat bahwa bakteri mengisi area antara aggregat dan matrix beton.

Influence of polyacrylic ester and silica fume on the mechanical properties of mortar for repair application

Directory of Open Access Journals (Sweden)

Chaohua Jiang

2016-12-01

Full Text Available Experimental investigations on the influence of different amounts of polyacrylic ester and silica fumes on the mechanical properties of mortar such as the compressive strength, splitting tensile strength, bonding strength, and abrasion resistance are presented in this article. The results show that the compressive and splitting tensile strength of mortar can be improved with the addition of polyacrylic ester and silica fumes. Results obtained from both the direct tensile bond test and flexural bond test indicate that the addition of polyacrylic ester and silica fumes improves the bond strength significantly, and the enhancement is more obvious with polyacrylic ester paste as interfacial adhesives. Furthermore, mortar incorporation of polyacrylic ester and silica fumes shows superior abrasion resistance compared to the control mortar. Therefore, the correct combination of polyacrylic ester and silica fumes to produce mortars has been shown to have synergistic effects, which results in excellent properties including high bond strength and superior abrasion resistance. Mortars containing polyacrylic ester and silica fumes are ideal for repairing concrete especially for hydraulic concrete structure.

Experimental investigation on high performance RC column with manufactured sand and silica fume

Science.gov (United States)

Shanmuga Priya, T.

2017-11-01

In recent years, the use High Performance Concrete (HPC) has increased in construction industry. The ingredients of HPC depend on the availability and characteristics of suitable alternative materials. Those alternative materials are silica fume and manufactured sand, a by products from ferro silicon and quarry industries respectively. HPC made with silica fume as partial replacement of cement and manufactured sand as replacement of natural sand is considered as sustainable high performance concrete. In this present study the concrete was designed to get target strength of 60 MPa as per guide lines given by ACI 211- 4R (2008). The laboratory study was carried out experimentally to analyse the axial behavior of reinforced cement HPC column of size 100×100×1000mm and square in cross section. 10% of silica fume was preferred over ordinary portland cement. The natural sand was replaced by 0, 20, 40, 60, 80 and 100% with Manufactured Sand (M-Sand). In this investigation, totally 6 column specimens were cast for mixes M1 to M6 and were tested in 1000kN loading frame at 28 days. From this, Load-Mid height deflection curves were drawn and compared. Maximum ultimate load carrying capacity and the least deflection is obtained for the mix prepared by partial replacement of cement with 10% silica fume & natural sand by 100% M-Sand. The fine, amorphous and pozzalonic nature of silica fume and fine mineral particles in M- Sand increased the stiffness of HPC column. The test results revealed that HPC can be produced by using M-Sand with silica fume.

Genotoxic Effects of Exposure to Gasoline Fumes on Petrol Pump Workers

OpenAIRE

Amrin Shaikh; Darshana Barot; Divya Chandel

2018-01-01

Background: Petrol pump workers are occupationally exposed to gasoline and its fumes consisting of several mutagenic chemicals. Objective: To evaluate the genotoxic effects of exposure to gasoline fumes on petrol pump workers. Methods: The study groups included 70 petrol pump workers (exposed group) and 70 healthy age-matched individuals with no known exposure (comparison group). Buccal micronucleus cytome assay (BMCyt) was performed to check the genotoxicity caused due to inhalation ...

A comparison of cytotoxicity and oxidative stress from welding fumes generated with a new nickel-, copper-based consumable versus mild and stainless steel-based welding in RAW 264.7 mouse macrophages.

Science.gov (United States)

Badding, Melissa A; Fix, Natalie R; Antonini, James M; Leonard, Stephen S

2014-01-01

Welding processes that generate fumes containing toxic metals, such as hexavalent chromium (Cr(VI)), manganese (Mn), and nickel (Ni), have been implicated in lung injury, inflammation, and lung tumor promotion in animal models. While federal regulations have reduced permissible worker exposure limits to Cr(VI), this is not always practical considering that welders may work in confined spaces and exhaust ventilation may be ineffective. Thus, there has been a recent initiative to minimize the potentially hazardous components in welding materials by developing new consumables containing much less Cr(VI) and Mn. A new nickel (Ni) and copper (Cu)-based material (Ni-Cu WF) is being suggested as a safer alternative to stainless steel consumables; however, its adverse cellular effects have not been studied. This study compared the cytotoxic effects of the newly developed Ni-Cu WF with two well-characterized welding fumes, collected from gas metal arc welding using mild steel (GMA-MS) or stainless steel (GMA-SS) electrodes. RAW 264.7 mouse macrophages were exposed to the three welding fumes at two doses (50 µg/ml and 250 µg/ml) for up to 24 hours. Cell viability, reactive oxygen species (ROS) production, phagocytic function, and cytokine production were examined. The GMA-MS and GMA-SS samples were found to be more reactive in terms of ROS production compared to the Ni-Cu WF. However, the fumes from this new material were more cytotoxic, inducing cell death and mitochondrial dysfunction at a lower dose. Additionally, pre-treatment with Ni-Cu WF particles impaired the ability of cells to phagocytize E. coli, suggesting macrophage dysfunction. Thus, the toxic cellular responses to welding fumes are largely due to the metal composition. The results also suggest that reducing Cr(VI) and Mn in the generated fume by increasing the concentration of other metals (e.g., Ni, Cu) may not necessarily improve welder safety.

Thermogravimetric analyses and mineralogical study of polymer modified mortar with silica fume

Directory of Open Access Journals (Sweden)

Alessandra Etuko Feuzicana de Souza Almeida

2006-09-01

Full Text Available Mineral and organic additions are often used in mortars to improve their properties. Microstructural investigation concerning the effects of styrene acrylic polymer and silica fume on the mineralogical composition of high-early-strength portland cement pastes after 28 days of hydration are presented in this paper. Thermogravimetry and derivative thermogravimetry were used to study the interaction between polymers and cement, as well as the extent of pozzolanic reaction of the mortars with silica fume. Differential scanning calorimetry and X ray diffraction were used to investigate the cement hydration and the effect of the additions. The results showed that the addition of silica fume and polymer reduces the portlandite formation due to delaying of Portland cement hydration and pozzolanic reaction.

Determining the Compressive, Flexural and Splitting Tensile Strength of Silica Fume Reinforced Lightweight Foamed Concrete

OpenAIRE

Mydin M.A.O.; Sani N. Md.; Mohd Yusoff M.A.; Ganesan S.

2014-01-01

This study investigated the performance of the properties of foamed concrete in replacing volumes of cement of 10%, 15% and 20% by weight. A control unit of foamed concrete mixture made with ordinary Portland cement (OPC) and 10%, 15% and 20% silica fume was prepared. Three mechanical property parameters were studied such as compressive strength, flexural strength and splitting tensile of foamed concrete with different percentages of silica fume. Silica fume is commonly used to increase the m...

Addition of Silica Fume to Improve Strength of Cement Paste

Science.gov (United States)

Chen, Jiajian; Chen, Hongniao; Li, Gu

2018-03-01

This study measured the packing densities of 0 to 30% silica fume (SF) added cementitious materials and strength of the cementitious pastes with various water content. The results revealed that addition of silica fume up to a certain level has great effects on packing density and strength. In-depth analysis illustrated that a lower W/CM ratio would not always result in a higher cube strength, and the range between 0.05 and 0.07 µm would be the amount of water film thickness (WFT) for muximum strength.

INFLUENCE OF SUBSTITUTION OF ORDINARY PORTLAND CEMENT BY SILICA FUME ON THE HYDRATION OF SLAG-PORTLAND CEMENT PASTES

Directory of Open Access Journals (Sweden)

E.A. El-Alfi

2011-06-01

Full Text Available Effect of gradual substitution of ordinary Portland cement by a few percent of silica fume (0.0, 2.5, 5.0 and 7.5 wt.% on the hydration properties of slag-Portland cement pastes up to 12 months was investigated. The results show that the composite cement pastes containing silica fume give the higher physico-mechanical properties than that of the slag-Portland cement. Also, the XRD results reveal that the peak of Ca(OH2 shows higher intensity in the sample without silica fume and completely disappears in the sample containing 7.5 wt.% silica fume content. Also, the intensity peaks of C4AH13 sharply increase with silica fume content.

Performance of laboratories analysing welding fume on filter samples: results from the WASP proficiency testing scheme.

Science.gov (United States)

Stacey, Peter; Butler, Owen

2008-06-01

This paper emphasizes the need for occupational hygiene professionals to require evidence of the quality of welding fume data from analytical laboratories. The measurement of metals in welding fume using atomic spectrometric techniques is a complex analysis often requiring specialist digestion procedures. The results from a trial programme testing the proficiency of laboratories in the Workplace Analysis Scheme for Proficiency (WASP) to measure potentially harmful metals in several different types of welding fume showed that most laboratories underestimated the mass of analyte on the filters. The average recovery was 70-80% of the target value and >20% of reported recoveries for some of the more difficult welding fume matrices were welding fume trial filter samples. Consistent rather than erratic error predominated, suggesting that the main analytical factor contributing to the differences between the target values and results was the effectiveness of the sample preparation procedures used by participating laboratories. It is concluded that, with practice and regular participation in WASP, performance can improve over time.

Effect of gasoline fumes on reproductive function in male albino rats.

Science.gov (United States)

Owagboriaye, Folarin O; Dedeke, Gabriel A; Ashidi, Joseph S; Aladesida, Adeyinka A; Olooto, Wasiu E

2018-02-01

The increase in the frequency of exposure to gasoline fumes and the growing incidence of infertility among humans has been a major concern and subject of discussion over the years in Nigeria. We therefore present the reproductive effect of gasoline fumes on inhalation exposure in 40 male albino rats. The rats were randomized into five experimental treatments (T) with eight rats per treatment. T1 (control) was exposed to distilled water while T2, T3, T4, and T5 were exposed to gasoline fumes in exposure chambers for 1, 3, 5, and 9 h daily respectively for 12 weeks. Serum level of testosterone, follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin, oxidative stress markers in the testicular tissue, epididymal sperm health assessment, and testicular histopathology of the rats were used as a diagnostic marker of reproductive dysfunction. Significant (p percentage motility in the exposed rats were observed. Significant (p < 0.05) increased in abnormal sperm cells characterized by damaged head, bent tail, damaged tail, and without head were also observed in the exposed rats. Histopathologically, severe degenerative testicular architectural lesions characterized by alterations in all the generations of sperm cells and reduction of interstitial cells were seen in the exposed rats. Gasoline fume is thus said to interfere with spermatogenesis and impair fertility in male gonad.

Characteristics of PAHs from deep-frying and frying cooking fumes.

Science.gov (United States)

Yao, Zhiliang; Li, Jing; Wu, Bobo; Hao, Xuewei; Yin, Yong; Jiang, Xi

2015-10-01

Cooking fumes are an important indoor source of polycyclic aromatic hydrocarbons (PAHs). Because indoor pollution has a more substantial impact on human health than outdoor pollution, PAHs from cooking fumes have drawn considerable attention. In this study, 16 PAHs emitted through deep-frying and frying methods using rapeseed, soybean, peanut, and olive oil were examined under a laboratory fume hood. Controlled experiments were conducted to collect gas- and particulate-phase PAHs emitted from the cooking oil fumes, and PAH concentrations were quantified via high-performance liquid chromatography (HPLC). The results show that deep-frying methods generate more PAHs and benzo[a]pyrene (B[a]P) (1.3 and 10.9 times, respectively) because they consume greater volumes of edible oil and involve higher oil temperatures relative to those of frying methods. In addition, the total B[a]Peq concentration of deep-frying is 2.2-fold larger than that of frying. Regarding the four types of edible oils studied, rapeseed oil produced more PAH emission than the other three oil varieties. For all of the cooking tests, three- and four-ringed PAHs were the main PAH components regardless of the food and oil used. Concerning the PAH partition between gas and particulate phase, the gaseous compounds accounted for 59-96 % of the total. Meanwhile, the particulate fraction was richer of high molecular weight PAHs (five-six rings). Deep-frying and frying were confirmed as important sources of PAH pollution in internal environments. The results of this study provide additional insights into the polluting features of PAHs produced via cooking activities in indoor environments.

A study of the bio-accessibility of welding fumes.

Science.gov (United States)

Berlinger, Balázs; Ellingsen, Dag G; Náray, Miklós; Záray, Gyula; Thomassen, Yngvar

2008-12-01

The respiratory bio-accessibility of a substance is the fraction that is soluble in the respiratory environment and is available for absorption. In the case of respiratory exposure the amount of absorbed substance plays a main role in the biological effects. Extensive bio-accessibility studies have always been an essential requirement for a better understanding of the biological effects of different workplace aerosols, such as welding fumes. Fumes generated using three different welding techniques, manual metal arc (MMA) welding, metal inert gas (MIG) welding, and tungsten inert gas (TIG) welding were investigated in the present study. Each technique was used for stainless steel welding. Welding fumes were collected on PVC membrane filters in batches of 114 using a multiport air sampler. Three different fluids were applied for the solubility study: deionised water and two kinds of lung fluid simulants: lung epithelial lining fluid simulant (Gamble's solution) and artificial lung lining fluid simulant (Hatch's solution). In order to obtain sufficient data to study the tendencies in solubility change with time, seven different leaching periods were used (0.5, 1, 2, 4, 8, 16, 24 h), each of them with three replicates. The effect of dissolution temperature was also studied. The total amounts of selected metals in the three different welding fumes were determined after microwave-assisted digestion with the mixture of aqua regia and hydrofluoric acid. The most obvious observation yielded by the results is that the solubility of individual metals varies greatly depending on the welding technique, the composition of the leaching fluid and leaching time. This study shows that the most reasonable choice as a media for the bio-assessment of solubility might be Hatch's solution by a dissolution time of 24 h.

Microarray-based analysis of the lung recovery process after stainless-steel welding fume exposure in Sprague-Dawley rats.

Science.gov (United States)

Oh, Jung-Hwa; Yang, Mi-jin; Yang, Young-Su; Park, Han-Jin; Heo, Sun Hee; Lee, Eun-Hee; Song, Chang-Woo; Yoon, Seokjoo

2009-02-01

Repeated exposure to welding fumes promotes a reversible increase in pulmonary disease risk, but the molecular mechanisms by which welding fumes induce lung injury and how the lung recovers from such insults are unclear. In the present study, pulmonary function and gene-expression profiles in the lung were analyzed by Affymetrix GeneChip microarray after 30 days of consecutive exposure to manual metal arc welding combined with stainless-steel (MMA-SS) welding fumes, and again after 30 days of recovery from MMA-SS fume exposure. In total, 577 genes were identified as being either up-regulated or down-regulated (over twofold changes, p process of the lung were up-regulated exclusively in the recovery group. Collectively, these data may help elucidate the molecular mechanism of the recovery process of the lung after welding fume exposure.

Dynamic Moisture Sorption and Desorption in Fumed Silica-filled Silicone Foam

Energy Technology Data Exchange (ETDEWEB)

Trautschold, Olivia Carol [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-09-02

Characterizing dynamic moisture sorption and desorption in fumed silica-filled silicone foam is necessary for determining material compatibilities and life predictions, particularly in sealed environments that may be exposed to a range of environmental conditions. Thermogravimetric analysis (TGA) and near infrared spectroscopy (NIR) were performed on S5470 fumed silica-filled silicone foam to determine the weight percent of moisture at saturation. Additionally, TGA was used to determine the time, temperature, and relative humidity levels required for sorption and desorption of physisorbed moisture in S5470.

Personal exposure to metal fume, NO2, and O3 among production welders and non-welders.

Science.gov (United States)

Schoonover, Todd; Conroy, Lorraine; Lacey, Steven; Plavka, Julie

2011-01-01

The objective of this study was to characterize personal exposures to welding-related metals and gases for production welders and non-welders in a large manufacturing facility. Welding fume metals and irritant gases nitrogen dioxide (NO(2)) and ozone (O(3)) were sampled for thirty-eight workers. Personal exposure air samples for welding fume metals were collected on 37 mm open face cassettes and nitrogen dioxide and ozone exposure samples were collected with diffusive passive samplers. Samples were analyzed for metals using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and welding fume metal exposure concentrations were defined as the sum of welding-related metals mass per volume of air sampled. Welding fume metal exposures were highly variable among similar types of welding while NO(2) and O(3) exposure were less variable. Welding fume metal exposures were significantly higher 474 μg/m(3) for welders than non-welders 60 μg/m(3) (p=0.001). Welders were exposed to higher concentrations of NO(2) and O(3) than non-welders but the differences were not statistically significant. Welding fume metal exposure concentrations for welders performing gas metal arc welding (GMAW) and shielded metal arc welding (SMAW) were higher than welders performing gas tungsten arc welding (GTAW). Non-welders experienced exposures similar to GTAW welders despite a curtain wall barrier separating welding and non-welding work areas.

The development and site investigation of fume diluter

Energy Technology Data Exchange (ETDEWEB)

Kim, Bok Youn; Kang, Chang Hee; Jo, Young Do; Lim, Sang Taek [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

1996-12-01

It is third project year on `Application of mobile diesel equipment in underground mines` for providing appropriate measures to improve underground working environment contaminated by the diesel exhaust pollutants. For reducing the exhaust temperature bellow 70 deg. C to prevent production of the governing pollutant (NO{sub 2}), the fume diluter is verified the most effective device through the site investigation. Therefore, the fume diluter is strongly recommended instead of catalytic converter which is employed presently. The performances derived from the tests are as follows; 1) This device increased air flow to 6.7-8.4 times of the original exhaust, 2) Exhaust temperature can be reduced to 66 deg. C from 161 deg. C, 3) All the pollutants can be reduced to bellow than 30 % of exhaust concentration, 4) This device requires less cost and no maintenance. (author). 4 tabs., 4 figs.

Properties of cement-fly ash grout admixed with bentonite, silica fume, or organic fiber

International Nuclear Information System (INIS)

Huang, W.H.

1997-01-01

A detailed laboratory study was conducted to investigate the properties of cement-fly ash grout mixtures as barriers for isolation of hazardous and low-level radioactive wastes. In the grout studied, fly ash was used to replace 30 percent by mass of cement. Three additives including bentonite, silica fume, and polypropylene fiber were used individually in the grout mixes to improve the properties of the grouts in different aspects. The flowability, bleeding, and setting time of freshly mixed grouts were determined; and the unconfined compressive strength, pore size distribution, and water permeability were determined for hardened grouts at various curing durations up to 120 days. Finally, the durability of cement-fly ash grouts was carefully examined in terms of the changes in their physical properties after different levels of exposure to sulfate attack and wet-dry cycles

Testing Silica Fume-Based Concrete Composites under Chemical and Microbiological Sulfate Attacks

Directory of Open Access Journals (Sweden)

Adriana Estokova

2016-04-01

Full Text Available Current design practices based on descriptive approaches to concrete specification may not be appropriate for the management of aggressive environments. In this study, the durability of cement-based materials with and without the addition of silica fume, subjected to conditions that leach calcium and silicon, were investigated. Chemical corrosion was simulated by employing various H2SO4 and MgSO4 solutions, and biological corrosion was simulated using Acidithiobacillus sp. bacterial inoculation, leading to disrupted and damaged surfaces; the samples’ mass changes were studied following both chemical and biological attacks. Different leaching trends were observed via X-ray fluorescence when comparing chemical with biological leaching. Lower leaching rates were found for concrete samples fortified with silica fume than those without silica fume. X-ray diffraction and scanning electron microscopy confirmed a massive sulfate precipitate formation on the concrete surface due to bacterial exposure.

Effects of Exposure to Welding Fume on Lung Function: Results from the German WELDOX Study.

Science.gov (United States)

Lehnert, M; Hoffmeyer, F; Gawrych, K; Lotz, A; Heinze, E; Berresheim, H; Merget, R; Harth, V; Van Gelder, R; Hahn, J-U; Hartwig, A; Weiß, T; Pesch, B; Brüning, T

2015-01-01

The association between exposure to welding fume and chronic obstructive pulmonary disease (COPD) has been insufficiently clarified. In this study we assessed the influence of exposure to welding fume on lung function parameters. We investigated forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), FEV1/FVC, and expiratory flow rates in 219 welders. We measured current exposure to respirable particles and estimated a worker's lifetime exposure considering welding techniques, working conditions and protective measures at current and former workplaces. Multiple regression models were applied to estimate the influence of exposure to welding fume, age, and smoking on lung function. We additionally investigated the duration of working as a welder and the predominant welding technique. The findings were that age- and smoking-adjusted lung function parameters showed no decline with increasing duration, current exposure level, and lifetime exposure to welding fume. However, 15% of the welders had FEV1/FVC below the lower limit of normal, but we could not substantiate the presence of an association with the measures of exposure. Adverse effects of cigarette smoking were confirmed. In conclusion, the study did not support the notion of a possible detrimental effect of exposure to welding fume on lung function in welders.

Effects on the efficiency of activated carbon on exposure to welding fumes

Energy Technology Data Exchange (ETDEWEB)

Ghosh, D. [Southern Company Services, Inc., Birmingham, AL (United States)

1995-02-01

It is the intention of this paper to document that certain types of welding fumes have little or no effect on the effectiveness of the carbon filter air filtration efficiency when directly exposed to a controlled amount of welding fumes for a short-term period. The welding processes studied were restricted to shielded metal arc welding (SMAW), flux cored arc welding (FCAW), gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) processes. Contrary to the SMAW and FCAW processes, the GTAW (or TIG) and the GMAW (or MIG) welding processes do not require the use of flux as part of the overall process. Credit was taken for these processes occurring in inert gas environments and producing minimal amount of smoke. It was concluded that a study involving the SMAW process would also envelop the effects of the TIG and MIG welding processes. The quantity of welding fumes generated during the arc welding process is a function of the particular process, the size and type of electrode, welding machine amperage, and operator proficiency. For this study, the amount of welding for specific testing was equated to the amount of welding normally conducted during plant unit outages. Different welding electrodes were also evaluated, and the subsequent testing was limited to an E7018 electrode which was judged to be representative of all carbon and stainless steel electrodes commonly used at the site. The effect of welding fumes on activated charcoal was tested using a filtration unit complete with prefilters, upstream and downstream high efficiency particulate air (HEPA) filters, and a carbon adsorber section. The complete system was field tested in accordance with ANSI N510 standards prior to exposing the filters and the adsorber bed to welding fumes. The carbon samples were tested at an established laboratory using ASTM D3803-1989 standards.

Bronchiolitis from nitrous fumes

Energy Technology Data Exchange (ETDEWEB)

Darke, C S; Warrack, A J.N.

1958-01-01

Gases of low solubility (e.g., NO/sub 2/) may not irritate upper respiratory tract but may act insidiously on lower tract producing edema and bronchiolitis. Cases of bronchiolitis (1 resulting in death) from exposure to brown nitrous fumes are reported. There were no or slight symptoms at first but severe ones after about 1 wk. Pathology appears as acute pulmonary edema with damage and desquamation of alveolar epithelium particularly and that of respiratory bronchioles somewhat. Patchy atelectasis, bronchopneumonia and disruption of fibers in cell walls may also occur. Severe cases have obliteration of lumen (bronchiolitis obliterans) with extreme distress and death.

Performance of Portland cement mixes containing silica fume and mixed with lime-water

Directory of Open Access Journals (Sweden)

Metwally A.A. Abd Elaty

2014-12-01

Test results show that using lime-water in mixing enhances consistency degree compared to the corresponding control mixes. Furthermore, it delays both initial and final setting times compared with traditional water due to the common ion effect principles. Moreover, combined use of lime-water and silica fume enhances the pozzolanic reaction that was identified by the strength development at both early and later ages. The existence of CH crystals for higher percentages of silica fume (up to 30% for further reaction at later ages was observed by XRD results. Moreover, combined use of silica fume and lime-water ensures a high alkaline media around steel bars from the moment of ingredients mixing as long as later ages despite of pozzolanic reaction that was identified from results of chloride attack.

Persistence of Change: Fume Hood Campaign Lessons

Science.gov (United States)

Feder, Elah; Robinson, Jennifer; Wakefield, Sarah

2012-01-01

Purpose: Sustainability initiatives typically operate for a limited time period, but it is often unclear whether they have lasting effects. The purpose of this paper is to examine a laboratory fume hood campaign, in order to identify factors that might contribute or detract from long-term change persistence. Design/methodology/approach: The…

Welding fumes from stainless steel gas metal arc processes contain multiple manganese chemical species.

Science.gov (United States)

Keane, Michael; Stone, Samuel; Chen, Bean

2010-05-01

Fumes from a group of gas metal arc welding (GMAW) processes used on stainless steel were generated using three different metal transfer modes and four different shield gases. The objective was to identify and measure manganese (Mn) species in the fumes, and identify processes that are minimal generators of Mn species. The robotic welding system was operated in short-circuit (SC) mode (Ar/CO2 and He/Ar), axial spray (AXS) mode (Ar/O2 and Ar/CO2), and pulsed axial-spray (PAXS) mode (Ar/O2). The fumes were analyzed for Mn by a sequential extraction process followed by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) analysis, and by X-ray diffraction (XRD). Total elemental Mn, iron (Fe), chromium (Cr) and nickel (Ni) were separately measured after aqua regia digestion and ICP-AES analysis. Soluble Mn2+, Fe2+, Fe3+, and Ni2+ in a simple biological buffer (phosphate-buffered saline) were determined at pH 7.2 and 5.0 after 2 h incubation at 37 C by ion chromatography. Results indicate that Mn was present in soluble form, acid-soluble form, and acid-soluble form after reduction by hydroxylamine, which represents soluble Mn0 and Mn2+ compounds, other Mn2+ compounds, and (Mn3+ and Mn4+) compounds, respectively. The dominant fraction was the acid-soluble Mn2+ fraction, but results varied with the process and shield gas. Soluble Mn mass percent in the fume ranged from 0.2 to 0.9%, acid-soluble Mn2+ compounds ranged from 2.6 to 9.3%, and acid plus reducing agent-soluble (Mn3+ and Mn4+) compounds ranged from 0.6 to 5.1%. Total Mn composition ranged from 7 to 15%. XRD results showed fumes had a crystalline content of 90-99% Fe3O4, and showed evidence of multiple Mn oxides, but overlaps and weak signals limited identification. Small amounts of the Mn2+ in the fume (welding process. Mn generation rates for the fractions were tabulated, and the influence of ozone is discussed. The conclusions are that exposures to welding fumes include multiple Mn species, both

Effect of silica fume on compressive strength of oil-polluted concrete in different marine environments

Science.gov (United States)

Shahrabadi, Hamid; Sayareh, Sina; Sarkardeh, Hamed

2017-12-01

In the present research, effect of silica fume as an additive and oil polluted sands as aggregates on compressive strength of concrete were investigated experimentally. The amount of oil in the designed mixtures was assumed to be constant and equal to 2% of the sand weight. Silica fume accounting for 10%, 15% and 20% of the weight is added to the designed mixture. After preparation and curing, concrete specimens were placed into the three different conditions: fresh, brackish and saltwater environments (submerged in fresh water, alternation of exposed in air & submerged in sea water and submerged in sea water). The result of compressive strength tests shows that the compressive strength of the specimens consisting of silica fume increases significantly in comparison with the control specimens in all three environments. The compressive strength of the concrete with 15% silica fume content was about 30% to 50% higher than that of control specimens in all tested environments under the condition of using polluted aggregates in the designed mixture.

Irritative effects of fumes and aerosols of bitumen on the airways: results of a cross-shift study

Energy Technology Data Exchange (ETDEWEB)

Raulf-Heimsoth, Monika; Pesch, Beate; Kappler, Martin; Marczynski, Boleslaw; Rihs, Hans Peter; Merget, Rolf; Bruening, Thomas [Institut der Ruhr-Universitaet Bochum, Berufsgenossenschaftliches Forschungsinstitut fuer Arbeitsmedizin (BGFA), Bochum (Germany); Schott, Klaus [Berufsgenossenschaft der Bauwirtschaft (BG BAU), Munich (Germany); Preuss, Ralf; Angerer, Juergen [Universitaet Erlangen, Institut und Poliklinik fuer Arbeits-, Sozial- und Umweltmedizin (IPASUM), Erlangen (Germany); Hahn, Jens Uwe [Berufsgenossenschaftliches Institut fuer Arbeitsschutz (BGIA), Sankt Augustin (Germany)

2007-01-15

Possible health hazards of fumes and aerosols of bitumen are in discussion, and data on their adverse effects on human airways under current exposure conditions are limited. To assess the irritative effects of exposure to fumes and aerosols of bitumen on the airways, a cross-sectional cross-shift study was conducted including external and internal exposure measurements, spirometry and especially non-invasive methods like nasal lavage collection and induction of sputum in order to identify and evaluate more precisely inflammatory process in the upper and lower airways. The cross-shift study comprised 74 mastic asphalt workers who were exposed to fumes and aerosols of bitumen and 49 construction workers without this exposure as reference group. Questionnaire, spirometry, ambient monitoring and urinary analysis were performed. Humoral and cellular parameters were measured in nasal lavage fluid (NALF) and induced sputum. For data analysis, a mixed linear model was performed on the different outcomes with exposure group, time of measurement (pre-, post-shift), current smoking, German nationality and age as fixed factors and subjects as random factor. Based on personal exposure measurements during shift, mastic asphalt workers were classified into a low ({<=}10 mg/m{sup 3}; n = 46) and a high (>10 mg/m{sup 3}; n = 28) exposure group. High exposure was accompanied by significant higher urinary post-shift concentrations of 1-hydroxypyrene and the sum of hydroxyphenanthrenes. Acute respiratory symptoms were reported more frequently in the high exposure group after shift. Significant cross-shift declines in lung function parameters (forced expiratory volume in 1 s [FEV{sub 1} (% predicted)] and forced vital capacity [FVC (% predicted)]) were measured in mastic asphalt workers. Pre-shift FEV{sub 1} (% predicted) and FVC (% predicted) were higher in the low exposure group. In pre- and post-shift NALF samples, interleukin (IL)-1{beta}-, IL-8- and total protein concentrations

Detailed characterization of welding fumes in personal exposure samples

International Nuclear Information System (INIS)

Quémerais, B; Mino, James; Amin, M R; Golshahi, H; Izadi, H

2015-01-01

The objective of the project was to develop a method allowing for detailed characterization of welding particles including particle number concentration, size distribution, surface chemistry and chemical composition of individual particles, as well as metal concentration of various welding fumes in personal exposure samples using regular sampling equipment. A sample strategy was developed to evaluate the variation of the collection methods on mass concentration. Samples were collected with various samplers and filters at two different locations using our collection system. The first location was using a robotic welding system while the second was manual welding. Collected samples were analysed for mass concentration using gravimetryand metal concentration using ICP/OES. More advanced analysis was performed on selected filters using X-Ray Photoelectron Spectroscopy to determine surface composition of the particles, and X-Ray Diffraction to determine chemical composition of the fumes. Results showed that the robotic system had a lot of variation in space when the collection system was located close to the weld. Collection efficiency was found to be quite variable depending upon the type of filter. As well, metal concentrations in blank filters were dependent upon the type of filter with MCE presenting with the highest blank values. Results obtained with the XRD and XPS systems showed that it was possible to analyse a small of powdered welding fume sample but results on filters were not conclusive. (paper)

Effect of temperature on physical and mechanical properties of concrete containing silica fume

International Nuclear Information System (INIS)

Saad, M.; Hanna, G.B.; Abo-El-Enein, S.A.; Kotkata, M.F.

1996-01-01

Heat-resistant materials are usually used for structural purposes. The need for such building materials is particularly important in the chemical and metallurgical industries and for the thermal shieldings of nuclear power plants. Thus the effect of high temperatures on physical and mechanical properties of concrete was investigated. In this study ordinary Portland cement has been partially replaced by ratios of silica fume. The heat treatment temperature varied from 100 to 600 C by increments of 100 C for three hours without any load. Concrete specimens were treated at each temperature level. The specimens were heated under the same condition for each temperature level. Comparison between physical and mechanical properties during heat treatment were investigated. All specimens were moist-cured for 28 days after casting. Tests were carried out on specimens cooled slowly to room temperature after heating. Results of this investigation indicated that the replacement of ordinary Portland cement by 10% silica fume by weight improved the compressive strength by about 64.6%, but replacement of ordinary Portland cement by silica fume by ratios 20 and 30% improved the compressive strength by only 28% at 600 C. This could be attributed to the additional tobermorite gel (CSH phase) which formed due to the reaction of silica fume with Ca(OH) 2

Effect of silica fume on reaction products of uranium (VI) with portland cement

International Nuclear Information System (INIS)

Tan Hongbin; Shaanxi Univ. of Technology, Hanzhong; Li Yuxiang

2005-01-01

Simulation of radioactive waste of U(VI) by uranyl nitrate and the effects of different additive quantities (12%, 20%, 30%, 35%, 40%) of silica fume on the products of U(VI) with Portland cement were studied at a hydrothermal condition of 180 degree C for a duration of one week. The X-ray powder diffraction examination results showed that the calcium uranate would be transformed into uranophane when the cement contained 30% silica fume. (authors)

Local exhaust ventilation for the control of welding fumes in the construction industry--a literature review.

Science.gov (United States)

Flynn, Michael R; Susi, Pam

2012-08-01

Arc welding is a common unit operation in the construction industry, where frequent changes in location and welding position make it more difficult to control fume exposures than in industries where fixed locations are the norm. Welders may be exposed to a variety of toxic airborne contaminants including manganese (Mn) and hexavalent chromium (CrVI). Local exhaust ventilation (LEV) is a well-known engineering control for welding fumes but has not been adopted widely in the construction industry. This literature review presents data on the performance of a variety of LEV systems for welding fume control from the construction (five references), shipyard (five references), and other industries. The studies indicate that LEV can reduce fume exposures to total particulate, Mn, and CrVI to levels below currently relevant standards. Field studies suggest that 40-50% or more reduction in exposure is possible with portable or fixed LEV systems relative to natural ventilation but that correct positioning of the hood and adequate exhaust flow rates are essential. Successful implementation of extraction guns for gas metal arc welding (GMAW) and flux core arc welding has been demonstrated, indicating that a successful balance between extraction airflow and shielding gas requirements is possible. Work practices are an important part of achieving successful control of fume exposures; in particular, positioning the hood close to the arc, checking exhaust flow rates, and avoiding the plume. Further research is needed on hood size effects for controlling welding fume with portable LEV systems and identifying and overcoming barriers to LEV use in construction.

PEMANFAATAN LIMBAH SERBUK MARMER PADA BETON SEBAGAI BAHAN PENGGANTI SEBAGIAN SEMEN DENGAN VARIASI PENGGUNAAN SILICA FUME

OpenAIRE

Agil Fitri Handayani; Agoes Soehardjono M.D.; Achfas Zacoeb

2015-01-01

The Utilization of Marble Powder Waste in Concrete Ma­­­­­­­­terials as a Partial Material Substitution of Cement  with the Variation Use of Silica Fume. The purpose of this study was to determine the effect of marble powder and silica fume on the mechanical pro­per­ties of concrete. This study used an experimental design using 16 group of testing materials with variety types of mixtures between marble powder and silica fume 0.00; 5.00; 10.00; and 15.00%. The wa­ter-cement ratio was 0.50 and ...

Enhancing the performance of green solid-state electric double-layer capacitor incorporated with fumed silica nanoparticles

Science.gov (United States)

Chong, Mee Yoke; Numan, Arshid; Liew, Chiam-Wen; Ng, H. M.; Ramesh, K.; Ramesh, S.

2018-06-01

Solid polymer electrolyte (SPE) based on fumed silica nanoparticles as nanofillers, hydroxylethyl cellulose (HEC) as host polymer, magnesium trifluoromethanesulfonate salt and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid is prepared by solution casting technique. The ionic conductivity, interactions of adsorbed ions on the host polymer, structural crystallinity and thermal stability are evaluated by electrochemical impedance spectroscopy (EIS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA), respectively. Ionic conductivity studies at room temperature reveals that the SPE with 2 wt. % of fumed silica nanoparticles gives the highest conductivity compared to its counterpart. The XRD and FTIR studies confirm the dissolution of salt, ionic liquid and successful incorporation of fumed silica nanoparticles with host polymer. In order to examine the performance of SPEs, electric double-layer capacitor (EDLC) are fabricated by using activated carbon electrodes. EDLC studies demonstrate that SPE incorporated with 2 wt. % fumed silica nanoparticles gives high specific capacitance (25.0 F/g) at a scan rate of 5 mV/s compared to SPE without fumed silica. Additionally, it is able to withstand 71.3% of capacitance from its initial capacitance value over 1600 cycles at a current density of 0.4 A/g.

After-blast fumes from ANFO mixtures - the effect of prill type and mixing techniques

Energy Technology Data Exchange (ETDEWEB)

Farnfield, R.; Wetherelt, A.

2003-06-01

Over the last couple of years the Technical Services Department of exchem explosives has received a number of enquiries regarding the nature of after-blast fumes. These enquiries have been driven by two concerns: site-related health and safety and public comment from people living close to blasting operations. The paper examines how these choices can impact the quality and quantity of after-blast fume. 3 refs., 9 figs., 3 tabs.

Effect of Generator (Exhaust) Fumes on the Growth and ...

African Journals Online (AJOL)

PROF HORSFALL

as the distance of the plants from the source of pollution increased, only the 3 m treatment led to significant ... plants were adversely affected by the fume emission especially at the distance of 3 m away from the ..... Principles of Biochemical.

Peak expiratory flow rate in asymptomatic male workers exposed to chemical fumes, in various industries of Hyderabad

Directory of Open Access Journals (Sweden)

Padaki Samata K, Dambal Amrut , Kokiwar Prashant

2014-11-01

Full Text Available Context: The prevalence of occupational health hazards and mortality has been reported to be unusually high among people of India. Although developed countries are very much careful about the health in occupations it is quite neglected in the developing countries like India. Aims: To record PEFR in asymptomatic male workers exposed to chemical fumes for more than 2 years and compare the results with age matched unexposed, healthy male controls. Methods and Material: This was a comparative study between 50 asymptomatic male workers exposed to chemical fumes for more than 2 years in various industries located at Jeedimetla Industrial Area and 50 unexposed healthy male individuals from general population. The sampling was done by simple random sampling (lottery method. The data was collected in the Research Laboratory of Physiology. Anthropometry like weight, height, was measured and the PEFR test was performed in the standing position by taking a deep inspiration and then blowing out as hard and as quickly as possible with their nose closed. Data was analyzed by using SPSS package and was expressed in terms of mean ± SD. Results: It was observed that mean PEFR was statistically highly significant in cases (p = 0.0001, and PEFR decreased with increase in duration of exposure. Conclusions: Thus, it can be concluded that apparently healthy individuals may also have abnormal PEFR findings. Hence, a regular check on these parameters will help them in reducing the chances of its manifestation at a future date.

Alterations in cardiomyocyte function after pulmonary treatment with stainless steel welding fume in rats.

Science.gov (United States)

Popstojanov, Risto; Antonini, James M; Salmen, Rebecca; Ye, Morgan; Zheng, Wen; Castranova, Vincent; Fekedulegn, Desta B; Kan, Hong

2014-01-01

Welding fume is composed of a complex of different metal particulates. Pulmonary exposure to different welding fumes may exert a negative impact on cardiac function, although the underlying mechanisms remain unclear. To explore the effect of welding fumes on cardiac function, Sprague-Dawley rats were exposed by intratracheal instillation to 2 mg/rat of manual metal arc hard surfacing welding fume (MMA-HS) once per week for 7 wk. Control rats received saline. Cardiomyocytes were isolated enzymatically at d 1 and 7 postexposure. Intracellular calcium ([Ca(2+)]i) transients (fluorescence ratio) were measured on the stage of an inverted phase-contrast microscope using a myocyte calcium imaging/cell length system. Phosphorylation levels of cardiac troponin I (cTnI) were determined by Western blot. The levels of nonspecific inflammatory marker C-reactive protein (CRP) and proinflammatory cytokine interleukin-6 (IL-6) in serum were measured by enzyme-linked immunosorbent assay (ELISA). Contraction of isolated cardiomyocytes was significantly reduced at d 1 and d 7 postexposure. Intracellular calcium levels were decreased in response to extracellular calcium stimulation at d 7 postexposure. Changes of intracellular calcium levels after isoprenaline hydrochloride (ISO) stimulation were not markedly different between groups at either time point. Phosphorylation levels of cTnI in the left ventricle were significantly lower at d 1 postexposure. The serum levels of CRP were not markedly different between groups at either time point. Serum levels of IL-6 were not detectable in both groups. Cardiomyocyte alterations observed after welding fume treatment were mainly due to alterations in intracellular calcium handling and phosphorylation levels of cTnI.

Prompt gamma analysis of fly ash, silica fume and Superpozz blended cement concrete specimen

Energy Technology Data Exchange (ETDEWEB)

Naqvi, A.A. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)], E-mail: aanaqvi@kfupm.edu.sa; Garwan, M.A. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Maslehuddin, M. [Center for Engineering Research, Research Institute, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Nagadi, M.M. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Al-Amoudi, O.S.B. [Department of Civil Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Khateeb-ur-Rehman; Raashid, M. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

2009-09-15

Preventive measures against corrosion of reinforcing steel require making the concrete dense by adding pozzolanic materials, such as fly ash, silica fume, Superpozz, blast furnace slag, etc. to Portland cement. In order to obtain the desired strength and durability of concrete, it is desirable to monitor the concentration of the pozzolan in the blended cement concrete. Addition of pozzolan to blended cement changes the overall concentration of calcium and silicon in the blended cement concrete. The resulting variation in calcium and silicon gamma-ray yield ratio from blended cement concrete has found to have an inverse correlation with concentration of fly ash, silica fume, Superpozz, blast furnace slag in the blended cement concrete. For experimental verification of the correlation, intensities of calcium and silicon prompt gamma-ray due to capture of thermal neutrons in blended cement concrete samples containing 5-80% (by weight of cement) silica fume, fly ash and Superpozz were measured. The gamma-ray intensity ratio was measured from 6.42 MeV gamma-rays from calcium and 4.94 MeV gamma-ray from silicon. The experimentally measured values of calcium to silicon gamma-ray yield ratio in the fly ash, silica fume and Superpozz cement concrete specimens agree very well with the results of the Monte Carlo simulations.

Prompt gamma analysis of fly ash, silica fume and Superpozz blended cement concrete specimen

International Nuclear Information System (INIS)

Naqvi, A.A.; Garwan, M.A.; Maslehuddin, M.; Nagadi, M.M.; Al-Amoudi, O.S.B.; Khateeb-ur-Rehman,; Raashid, M.

2009-01-01

Preventive measures against corrosion of reinforcing steel require making the concrete dense by adding pozzolanic materials, such as fly ash, silica fume, Superpozz, blast furnace slag, etc. to Portland cement. In order to obtain the desired strength and durability of concrete, it is desirable to monitor the concentration of the pozzolan in the blended cement concrete. Addition of pozzolan to blended cement changes the overall concentration of calcium and silicon in the blended cement concrete. The resulting variation in calcium and silicon gamma-ray yield ratio from blended cement concrete has found to have an inverse correlation with concentration of fly ash, silica fume, Superpozz, blast furnace slag in the blended cement concrete. For experimental verification of the correlation, intensities of calcium and silicon prompt gamma-ray due to capture of thermal neutrons in blended cement concrete samples containing 5-80% (by weight of cement) silica fume, fly ash and Superpozz were measured. The gamma-ray intensity ratio was measured from 6.42 MeV gamma-rays from calcium and 4.94 MeV gamma-ray from silicon. The experimentally measured values of calcium to silicon gamma-ray yield ratio in the fly ash, silica fume and Superpozz cement concrete specimens agree very well with the results of the Monte Carlo simulations.

Dyrkning af jatropha blandt småbønder i Mozambique - En strategi til reduceret CO2-udledning og lokal udvikling?

DEFF Research Database (Denmark)

Rasmussen, Laura Vang

2010-01-01

I Cabo Delgado-regionen i det nordlige Mozambique er småbønder inden for de sidste tre år begyndt at dyrke biobrændselsafgrøden jatropha. Bønderne har plantet jatrophatræer som hække langs de eksisterende majsmarker. Da dyrkningen af jatropha anses for en strategi til at skabe lokal udvikling i...

The Study Of Histopathological Effects Of Welding Fumes On Spermatogenesis In Rat

Directory of Open Access Journals (Sweden)

Arab M R

2005-07-01

Full Text Available Background: Fumes generated during electric welding are one of air pollutants of working place in industrial companies, which can cause some clinical signs and diseases in worker, including mucosal irritation, changing of semen quality and cancer. Chronic exposure of workers with these fumes can cause reduce sperm motility and forward penetration and decrease in normal sperm count. Although a lot of researches were done in this field up to now, there is little information about histopathological effects of these fumes on germinal epithelium. The aim of this study was to identify structural changes of germinal epithelium in Rat as an experimental model after exposure to fumes of electric welding in exposure chamber. Material and Methods: A total number of 60 Sprague Dawley Rats were chosen and divided into experimental (40 and control (20 groups. Each of groups was subdivided into 2, 4, 6 and 8-week subgroups. The number of Rat in each subgroup of experimental and control group was 10 and 5 respectively. Animals were housed in standard situation. After adaptation experimental group were exposed to fumes of electric welding (AMA 2000 electrode, 100 Ampere, 0.1 cm/s speed of electrode welding for 2 hour/day and 5 day/week. The rate of air turn over in exposure chamber was fixed to 12-15/hour. The amount of O3, CO, CO2, NO + NO2 and particulate matter were measured by Galtec detectors and Cellulose acetate filter respectively. According to time table animals were killed and specimens from testis were taken and fixed in formaline buffer solution and processed routinely. Sections with 5-7 micrometer in thickness were stained by H-E, PAS, PNA and Alcian blue pH=2.5. The thickness of germinal epithelium was measured and data were analyzed by Kruskall Wallis test. Results: The results of this study showed a few quantitative and qualitative changes in germinal epithelium. Vasodilatation of vessels in tunica albuginea and interstitial tissue, decreasing of

Particle release and control of worker exposure during laboratory-scale synthesis, handling and simulated spills of manufactured nanomaterials in fume hoods

Science.gov (United States)

Fonseca, Ana S.; Kuijpers, Eelco; Kling, Kirsten I.; Levin, Marcus; Koivisto, Antti J.; Nielsen, Signe H.; Fransman, W.; Fedutik, Yijri; Jensen, Keld A.; Koponen, Ismo K.

2018-02-01

Fume hoods are one of the most common types of equipment applied to reduce the potential of particle exposure in laboratory environments. A number of previous studies have shown particle release during work with nanomaterials under fume hoods. Here, we assessed laboratory workers' inhalation exposure during synthesis and handling of CuO, TiO2 and ZnO in a fume hood. In addition, we tested the capacity of a fume hood to prevent particle release to laboratory air during simulated spillage of different powders (silica fume, zirconia TZ-3Y and TiO2). Airborne particle concentrations were measured in near field, far field, and in the breathing zone of the worker. Handling CuO nanoparticles increased the concentration of small particles (control during synthesis and handling of nanomaterials. An appropriate fume hood with adequate sash height and face velocity prevents 98.3% of particles release into the surrounding environment. Care should still be made to consider spills and high cleanliness to prevent exposure via resuspension and inadvertent exposure by secondary routes.

Association between cooking oil fume exposure and lung cancer among Chinese nonsmoking women: a meta-analysis

Directory of Open Access Journals (Sweden)

Xue Y

2016-05-01

Full Text Available Yingbo Xue, Ying Jiang, Shan Jin, Yong Li Department of Oncology, Guizhou Provincial People’s Hospital, Guiyang, Guizhou, People’s Republic of China Abstract: Lung cancer has been the main cause of cancer death around the world. Cigarette smoking has been identified as a risk factor for lung cancer in males. However, the etiological factors in nonsmoking women remain elusive. A meta-analysis was conducted to evaluate the relationship between cooking oil fume exposure and lung cancer among Chinese nonsmoking women. Thirteen articles containing three population-based case–control and ten hospital-based case–control studies were included in this meta-analysis. These studies with a total of 3,596 lung cancer women and 6,082 healthy controls were analyzed by RevMan 5.3. Fixed effects model or random effects model was used to obtain pooled estimates of risk ratio. The risk ratios with a 95% CI were 1.74 (95% CI =1.57–1.94 and 2.11 (95% CI =1.54–2.89, respectively. Cooking oil fume exposure as well as not using a kitchen ventilator when cooking was significantly associated with lung cancer among nonsmoking women (Z=10.07, P<0.00001; Z=4.65, P<0.00001. Cooking oil fume exposure, especially lacking a fume extractor, may increase the risk of lung cancer among Chinese nonsmoking women. Keywords: cooking oil fume exposure, lung cancer, meta-analysis, nonsmoking women 

Performance of soft clay stabilized with sand columns treated by silica fume

Directory of Open Access Journals (Sweden)

Samueel Zeena

2018-01-01

Full Text Available In many road construction projects, if weak soil exists, then uncontrollable settlement and critical load carrying capacity are major difficult problems to the safety and serviceability of roads in these areas. Thus ground improvement is essential to achieve the required level of performance. The paper presents results of the tests of four categories. First category was performed on saturated soft bed of clay without any treatment, the second category shed light on the improvement achieved in loading carrying capacity and settlement as a result of reinforcing with conventional sand columns at area replacement ratio = 0.196. The third set investigates the bed reinforced by sand columns stabilized with dry silica fume at different percentages (3, 5 and 7% and the fourth set investigates the behavior of sand columns treated with slurry silica fume at two percentages (10 and 12%. All sand columns models were constructed at (R.D= 60%. Model tests were performed on bed of saturated soil prepared at undrained shear strength between 16-20 kPa for all models. For all cases, the model test was loaded gradually by stress increments up to failure. Stress deformation measurements are recorded and analyzed in terms of bearing improvement ratio and settlement reduction ratio. Optimum results were indicated from soil treated with sand columns stabilized with 7% dry silica fume at medium state reflecting the highest bearing improvement ratio (3.04 and the settlement reduction ratio (0.09 after 7 days curing. While soil treated with sand columns stabilized with 10% slurry silica fume provided higher bearing improvement ratio 3.13 with lower settlement reduction ratio of 0.57 after 7-days curing.

The Relationship of Welding Fume Exposure, Smoking, and Pulmonary Function in Welders.

Science.gov (United States)

Roach, Laura L

2018-01-01

The purpose of this study was to explore the relationship between occupational exposure to welding fumes and pulmonary function in an effort to add supportive evidence and clarity to the current body of research. This study utilized a retrospective chart review of pulmonary function testing and pulmonary questionnaires already available in charts from preplacement physicals to the most recent test. When comparing smokers to nonsmokers, utilizing multiple regression and controlling for age and percentage of time using a respirator, years welding was statistically significant at p = .04. Data support that smoking has a synergistic effect when combined with welding fume exposure on pulmonary decline.

Systemic serum amyloid A as a biomarker for exposure to zinc and/or copper-containing metal fumes.

Science.gov (United States)

Baumann, R; Gube, M; Markert, A; Davatgarbenam, S; Kossack, V; Gerhards, B; Kraus, T; Brand, P

2018-01-01

Zinc- and copper-containing welding fumes increase systemic C-reactive protein (CRP). The aim of this study was to investigate the performance of the biomarkers serum amyloid A (SAA) and soluble vascular cell adhesion molecule-1 (VCAM-1) in this regard. Fifteen male subjects were exposed under controlled conditions to welding fumes containing either zinc, or copper, or copper and zinc for 6 h. Plasma samples were collected before, 6 and 24 h after start of exposure and biomarkers therein were measured by electrochemiluminescent assay. For each exposure, systemic concentrations of systemic SAA, but not VCAM-1, increased significantly at 24 h after exposure start compared with baseline ("copper only": P=0.0005, "zinc only": P=0.027, "copper and zinc": P=0.001). SAA showed a wider range of concentrations than did CRP and its levels increased up to 19-fold after welding fume exposure. The recognition of copper as a potential harmful component in welding fumes, also independent from zinc, deserves further consideration. SAA might represent a new sensitive biomarker for potential subclinical sterile inflammation after inhalation of copper- and/or zinc-containing welding fumes. As elevations of CRP and SAA protein have both been linked to a higher risk for cardiovascular disease, these findings might particularly be important for long-term welders.

Isothermal model investigation of fume extraction systems for the scrap burner at Appleby Frodingham

Energy Technology Data Exchange (ETDEWEB)

Robinson, D.

1976-08-01

Model tests have been made on three suggested schemes for improving the efficiency of fume collection on the scrap burning installation in the Anchor BOS plant at Appleby Frodingham. In particular the usefulness of air curtains as a means of containing the fume has been examined. CO/sub 2/ tracer measurements, and photographs using smoke for visualization have allowed the assessment of the collection efficiencies of the three schemes, and some alterative solutions have been investigated using similar methods. (GRA)

Evaluation of one-step luminescent cyanoacrylate fuming.

Science.gov (United States)

Khuu, Alicia; Chadwick, Scott; Spindler, Xanthe; Lam, Rolanda; Moret, Sébastien; Roux, Claude

2016-06-01

One-step luminescent cyanoacrylates have recently been introduced as an alternative to the conventional cyanoacrylate fuming methods. These new techniques do not require the application of a luminescent post-treatment in order to enhance cyanoacrylate-developed fingermarks. In this study, three one-step polymer cyanoacrylates: CN Yellow Crystals (Aneval Inc.), PolyCyano UV (Foster+Freeman Ltd.) and PECA Multiband (BVDA), and one monomer cyanoacrylate: Lumikit™ (Crime Scene Technology), were evaluated against a conventional two-step cyanoacrylate fuming method (Cyanobloom (Foster+Freeman Ltd.) with rhodamine 6G stain). The manufacturers' recommended conditions or conditions compatible with the MVC™ 1000/D (Foster+Freeman Ltd.) were assessed with fingermarks aged for up to 8 weeks on non-porous and semi-porous substrates. Under white light, Cyanobloom generally gave better development than the one-step treatments across the substrates. Similarly when viewed under the respective luminescent conditions, Cyanobloom with rhodamine 6G stain resulted in improved contrast against the one-step treatments except on polystyrene, where PolyCyano UV and PECA Multiband gave better visualisation. Rhodamine 6G post-treatment of one-step samples did not significantly enhance the contrast of any of the one-step treatments against Cyanobloom/rhodamine 6G-treated samples. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Effect of silica fume on the fresh and hardened properties of fly ash-based self-compacting geopolymer concrete

Science.gov (United States)

Memon, Fareed Ahmed; Nuruddin, Muhd Fadhil; Shafiq, Nasir

2013-02-01

The effect of silica fume on the fresh and hardened properties of fly ash-based self-compacting geopolymer concrete (SCGC) was investigated in this paper. The work focused on the concrete mixes with a fixed water-to-geopolymer solid (W/Gs) ratio of 0.33 by mass and a constant total binder content of 400 kg/m3. The mass fractions of silica fume that replaced fly ash in this research were 0wt%, 5wt%, 10wt%, and 15wt%. The workability-related fresh properties of SCGC were assessed through slump flow, V-funnel, and L-box test methods. Hardened concrete tests were limited to compressive, splitting tensile and flexural strengths, all of which were measured at the age of 1, 7, and 28 d after 48-h oven curing. The results indicate that the addition of silica fume as a partial replacement of fly ash results in the loss of workability; nevertheless, the mechanical properties of hardened SCGC are significantly improved by incorporating silica fume, especially up to 10wt%. Applying this percentage of silica fume results in 4.3% reduction in the slump flow; however, it increases the compressive strength by 6.9%, tensile strength by 12.8% and flexural strength by 11.5%.

Karakteristik og vurdering af Time-Driven Activity-Based Costing på baggrund af ABC’s udvikling

DEFF Research Database (Denmark)

Israelsen, Poul; Kristensen, Thomas Borup

2015-01-01

Artiklen giver en beskrivelse af Activity Based Costings udvikling i fire varianter. Disse benyttes som grundlag for at karakterisere og vurdere de ændringer, som foretages i Time-Driven ABC (TDABC). Det konkluderes at TDABC i nogle tilfælde griber tilbage til omkostningskalkulation forud for ABC......’s tilblivelse (f.eks. homogene afdelinger i stedet for aktiviteter), i andre tilfælde til ABC’s oprindelse (f.eks. brug af transaktionsdrivere i stedet for mere sofistikerede drivere), og på andre områder til metoder uden for ABC’s normale anvendelse (f.eks. “standard variable costing”). Alt i alt argumenteres...

Association between cooking oil fume exposure and lung cancer among Chinese nonsmoking women: a meta-analysis.

Science.gov (United States)

Xue, Yingbo; Jiang, Ying; Jin, Shan; Li, Yong

2016-01-01

Lung cancer has been the main cause of cancer death around the world. Cigarette smoking has been identified as a risk factor for lung cancer in males. However, the etiological factors in nonsmoking women remain elusive. A meta-analysis was conducted to evaluate the relationship between cooking oil fume exposure and lung cancer among Chinese nonsmoking women. Thirteen articles containing three population-based case-control and ten hospital-based case-control studies were included in this meta-analysis. These studies with a total of 3,596 lung cancer women and 6,082 healthy controls were analyzed by RevMan 5.3. Fixed effects model or random effects model was used to obtain pooled estimates of risk ratio. The risk ratios with a 95% CI were 1.74 (95% CI =1.57-1.94) and 2.11 (95% CI =1.54-2.89), respectively. Cooking oil fume exposure as well as not using a kitchen ventilator when cooking was significantly associated with lung cancer among nonsmoking women (Z=10.07, Poil fume exposure, especially lacking a fume extractor, may increase the risk of lung cancer among Chinese nonsmoking women.

Hepatotoxic and Nephrotoxic Effects of Petroleum Fumes on Petrol ...

African Journals Online (AJOL)

The present study was conducted to evaluate the hepatotoxic and nephrotoxic effects of petroleum fumes on male and female petrol attendants. Investigations had been carried out on thirty (30) adult petrol attendants from different filling stations in Ibadan metropolis of Nigeria with ten (10) healthy adults as control. All the ...

In situ polymerization of L-Lactide in the presence of fumed silica

International Nuclear Information System (INIS)

Prebe, A.; Alcouffe, P.; Cassagnau, Ph.; Gerard, J.F.

2010-01-01

Chemiorheology, i.e. rheological changes during the polymerization, of a biosourced monomer, i.e. L-Lactide, containing fumed silica have been studied. For that purpose, the reaction was proceeded in situ between the plates of a dynamic rheometer. The polymerization kinetics was followed from the variation of the complex shear modulus versus reaction time. Moreover, at temperatures lower than the crystallization temperature, it was possible to follow the crystallization process while the polymerization takes place. Adding fumed silica particles into the monomer leads to the formation of a physical (percolated) network from particle-particle interactions, i.e. silica, in the L-Lactide probably hydrophilic interactions. The gel-like structure was kept while the polymerization as long as the strain remains low indicating that the silica particle network remains weak. Furthermore, the mechanism of the break down of the gel structure under large deformation as well as the recovery was discussed. It seems that the non-linearity effect of the nanocomposites stems in the silica inter-particle interactions. It was found that silica particles do not have any effect on the temperature of crystallization - molar mass relation but could act as nucleating agent. In situ polymerization of L-Lactide in the presence of 5 wt.% of modified fumed silica was carried out in a reactor. It was found that fumed hydrophilic silica leaded to a microcomposite with highly dense agglomerates in the polymer matrix whereas with a less hydrophilic silica it was possible to decrease the size of the agglomerates increasing the dispersion. The finest dispersion state was achieved with the 'initiating' functionalized silica leading to a 'grafting from' polymerization of the L-Lactide. Such functionalized silica leads to a nanoscale dispersion in a one-step bulk polymerization with only a few small agglomerates.

Characterization of the early pulmonary inflammatory response associated with PTFE fume exposure

Science.gov (United States)

Johnston, C. J.; Finkelstein, J. N.; Gelein, R.; Baggs, R.; Oberdorster, G.; Clarkson, T. W. (Principal Investigator)

1996-01-01

Heating of polytetrafluoroethylene (PTFE) has been described to release fumes containing ultrafine particles (approximately 18 nm diam). These fumes can be highly toxic in the respiratory tract inducing extensive pulmonary edema with hemorrhagic inflammation. Fischer-344 rats were exposed to PTFE fumes generated by temperatures ranging from 450 to 460 degrees C for 15 min at an exposure concentration of 5 x 10(5) particles/cm3, equivalent to approximately 50 micrograms/m3. Responses were examined 4 hr post-treatment when these rats demonstrated 60-85% neutrophils (PMNs) in their lung lavage. Increases in abundance for messages encoding the antioxidants manganese superoxide dismutase and metallothionein (MT) increased 15- and 40-fold, respectively. For messages encoding the pro- and anti-inflammatory cytokines: inducible nitric oxide synthase, interleukin 1 alpha, 1 beta, and 6 (IL-1 alpha, IL-1 beta, and IL-6), macrophage inflammatory protein-2, and tumor necrosis factor-alpha (TNF alpha) increases of 5-, 5-, 10-, 40-, 40-, and 15-fold were present. Vascular endothelial growth factor, which may play a role in the integrity of the endothelial barrier, was decreased to 20% of controls. In situ sections were hybridized with 33P cRNA probes encoding IL-6, MT, surfactant protein C, and TNF alpha. Increased mRNA abundance for MT and IL-6 was expressed around all airways and interstitial regions with MT and IL-6 demonstrating similar spatial distribution. Large numbers of activated PMNs expressed IL-6, MT, and TNF alpha. Additionally, pulmonary macrophages and epithelial cells were actively involved. These observations support the notion that PTFE fumes containing ultrafine particles initiate a severe inflammatory response at low inhaled particle mass concentrations, which is suggestive of an oxidative injury. Furthermore, PMNs may actively regulate the inflammatory process through cytokine and antioxidant expression.

In situ polymerization of L-Lactide in the presence of fumed silica

Energy Technology Data Exchange (ETDEWEB)

Prebe, A. [Universite de Lyon, F-69361, Lyon (France); CNRS, UMR 5223, Ingenierie des Materiaux Polymeres, F-69622, Villeurbanne (France); Universite Claude Bernard Lyon 1, F-69622, Villeurbanne (France); INSA Lyon, F-69621, Villeurbanne (France); Alcouffe, P. [Universite de Lyon, F-69361, Lyon (France); CNRS, UMR 5223, Ingenierie des Materiaux Polymeres, F-69622, Villeurbanne (France); Universite Claude Bernard Lyon 1, F-69622, Villeurbanne (France); Cassagnau, Ph., E-mail: philippe.cassagnau@univ-lyon1.fr [Universite de Lyon, F-69361, Lyon (France); CNRS, UMR 5223, Ingenierie des Materiaux Polymeres, F-69622, Villeurbanne (France); Universite Claude Bernard Lyon 1, F-69622, Villeurbanne (France); Gerard, J.F. [Universite de Lyon, F-69361, Lyon (France); CNRS, UMR 5223, Ingenierie des Materiaux Polymeres, F-69622, Villeurbanne (France); INSA Lyon, F-69621, Villeurbanne (France)

2010-11-01

Chemiorheology, i.e. rheological changes during the polymerization, of a biosourced monomer, i.e. L-Lactide, containing fumed silica have been studied. For that purpose, the reaction was proceeded in situ between the plates of a dynamic rheometer. The polymerization kinetics was followed from the variation of the complex shear modulus versus reaction time. Moreover, at temperatures lower than the crystallization temperature, it was possible to follow the crystallization process while the polymerization takes place. Adding fumed silica particles into the monomer leads to the formation of a physical (percolated) network from particle-particle interactions, i.e. silica, in the L-Lactide probably hydrophilic interactions. The gel-like structure was kept while the polymerization as long as the strain remains low indicating that the silica particle network remains weak. Furthermore, the mechanism of the break down of the gel structure under large deformation as well as the recovery was discussed. It seems that the non-linearity effect of the nanocomposites stems in the silica inter-particle interactions. It was found that silica particles do not have any effect on the temperature of crystallization - molar mass relation but could act as nucleating agent. In situ polymerization of L-Lactide in the presence of 5 wt.% of modified fumed silica was carried out in a reactor. It was found that fumed hydrophilic silica leaded to a microcomposite with highly dense agglomerates in the polymer matrix whereas with a less hydrophilic silica it was possible to decrease the size of the agglomerates increasing the dispersion. The finest dispersion state was achieved with the 'initiating' functionalized silica leading to a 'grafting from' polymerization of the L-Lactide. Such functionalized silica leads to a nanoscale dispersion in a one-step bulk polymerization with only a few small agglomerates.

Effects of welding fumes on nuclear air cleaning system carbon adsorber banks

Energy Technology Data Exchange (ETDEWEB)

Roberson, P.W. [Duke Power Company, Huntersville, NC (United States)

1997-08-01

Standard Technical Specifications for nuclear air cleaning systems include requirements for surveillance tests following fire, painting, or chemical release in areas communicating with the affected system. To conservatively implement this requirement, many plants categorize welding as a chemical release process, and institute controls to ensure that welding fumes do not interact with carbon adsorbers in a filter system. After reviewing research data that indicated welding had a minimal impact on adsorber iodine removal efficiency, further testing was performed with the goal of establishing a welding threshold. It was anticipated that some quantity of weld electrodes could be determined that had a corresponding detrimental impact on iodine removal efficiency for the exposed adsorber. This value could be used to determine a conservative sampling schedule that would allow the station to perform laboratory testing to ensure system degradation did not occur without a full battery of surveillance tests. A series of tests was designed to demonstrate carbon efficiency versus cumulative welding fume exposure. Three series of tests were performed, one for each of three different types of commonly used weld electrodes. Carbon sampling was performed at baseline conditions, and every five pounds of electrode thereafter. Two different laboratory tests were performed for each sample; one in accordance with ASTM 3803/1989 at 95% relative humidity and 30 degrees C, and another using the less rigorous conditions of 70% relative humidity and 80 degrees C. Review of the test data for all three types of electrodes failed to show a significant correlation between carbon efficiency degradation and welding fume exposure. Accordingly, welding is no longer categorized as a `chemical release process` at McGuire Nuclear Station, and limits on welding fume interaction with ventilation systems have been eliminated. 4 refs., 3 figs., 1 tab.

PEMANFAATAN LIMBAH SERBUK MARMER PADA BETON SEBAGAI BAHAN PENGGANTI SEBAGIAN SEMEN DENGAN VARIASI PENGGUNAAN SILICA FUME

Directory of Open Access Journals (Sweden)

Agil Fitri Handayani

2015-02-01

Full Text Available The Utilization of Marble Powder Waste in Concrete Ma­­­­­­­­terials as a Partial Material Substitution of Cement  with the Variation Use of Silica Fume. The purpose of this study was to determine the effect of marble powder and silica fume on the mechanical pro­per­ties of concrete. This study used an experimental design using 16 group of testing materials with variety types of mixtures between marble powder and silica fume 0.00; 5.00; 10.00; and 15.00%. The wa­ter-cement ratio was 0.50 and a low dosage of superplasticizer, which was 0.50%. The behavior of fresh concrete were calculated and the mechanical properties of concrete were tested on con­crete age of 28 days. The results showed the marble powder main com­position was Silicon Dioxide (SiO2 17.63% and Calcium Carbonate (CaCO3 2.73%. Mar­ble powder was more appropriate to be used as fillers than to be used as a partial substitution of ce­ment. The optimum mechanical properties of concrete was produced by the mixtures of 5.00% mar­ble powder  and 6.22% silica fume which resulted in compressive strength of 29.04 MPa.   Tujuan penelitian ini adalah untuk mengetahui pengaruh peng­gunaan ser­buk marmer dan silica fume terhadap sifat mekanik beton. Penelitian ini meng­gu­na­kan desain eksperimen dengan 16 kelompok benda uji dengan variasi ser­buk marmer dan silica fume 0,00; 5,00; 10,00; dan 15,00%. Faktor air semen di­gu­nakan 0,50 dan superplasticizer dengan dosis rendah 0,50%. Perilaku beton segar di­perhitungkan dan sifat mekanik beton diuji pada umur beton 28 hari. Hasil analisis me­nunjukkan kom­posisi utama serbuk marmer adalah Silikon Dioksida (SiO2 17,63% dan Kalsium Kar­bonat (CaCO3 2,73%. Serbuk marmer lebih tepat digunakan se­bagai bahan pe­ng­isi atau filler dari pada sebagai pengganti semen. Sifat mekanik be­ton optimum di­ha­sil­kan pada campuran serbuk marmer 5,00% dan silica fume 6,22% dengan kuat tekan be­ton yang dihasilkan  mencapai 29

Urinary β2 Microglobulin in Workers Exposed to Arc Welding Fumes

Directory of Open Access Journals (Sweden)

Khosro Sadeghniiat-Haghighi

2011-11-01

Full Text Available Welding is a process in which two or more metals are attached by the use of heat and, in some cases, pressure. Direct exposure and inhalation of welding fumes causes acute and chronic side effects in humans. Kidney damage is one of these important side effects. β2 microglobulin is an 11.8 kilodalton protein and levels increase in the case of some inflammatory and viral diseases, or kidney malfunction and autoimmune diseases. In this study measurements of β2 microglobulin were used as a criterion for assessing effects on the kidneys of workers exposed to welding fumes. The study population were electric arc welders in an industrial plant in Tehran, Iran. For control we selected workers who did not have any exposure to welding fumes. Both groups were selected on the basis of a questionnaire and the consideration of criteria for inclusion and exclusion. In the end 50 cases and 50 controls were chosen. A urine sample was collected from all participants and urinary pH was set to between 6-8 using NaOH (1M. Sample transportation to the laboratory complied with the related standards. The samples were assessed using the ORG 5BM kit. For quantitative assessment of β2 microglobulin we used the Enzyme-linked Immunosorbent Assay (ELISA method. The ages of the welders ranged from 21 to 48 years (mean=30.5±5.9 yrs and of controls from 23 to 56 years (mean=31.8±5.9 yrs. Mean employment duration was 7.86±5.01years (range 2 to 27 years for welders. Mean β2 microglobulin level was 0.10±0.096 μg/ml in welders and 0.11±0.06 in controls. This difference was not statistically significant (P=0.381. In conclusion we don't find that exposure to electric arc welding fumes cause a significant change in urinary β2 microglobulin compared to the control group.

Effect of plasticizer and fumed silica on ionic conductivity behaviour ...

Indian Academy of Sciences (India)

behaviour of proton conducting polymer electrolytes containing different concentrations of hexafluorophosphoric acid (HPF6) in polyethylene oxide ... Polymer electrolytes; ionic conductivity; polyethylene oxide; plasticizer; fumed silica. 1. Introduction ..... is a rapid weight loss which could be due to the degradation of polymer ...

Airborne nanoparticle exposures associated with the manual handling of nanoalumina and nanosilver in fume hoods

International Nuclear Information System (INIS)

Tsai, Su-Jung; Ada, Earl; Isaacs, Jacqueline A.; Ellenbecker, Michael J.

2009-01-01

Manual handling of nanoparticles is a fundamental task of most nanomaterial research; such handling may expose workers to ultrafine or nanoparticles. Recent studies confirm that exposures to ultrafine or nanoparticles produce adverse inflammatory responses in rodent lungs and such particles may translocate to other areas of the body, including the brain. An important method for protecting workers handling nanoparticles from exposure to airborne nanoparticles is the laboratory fume hood. Such hoods rely on the proper face velocity for optimum performance. In addition, several other hood design and operating factors can affect worker exposure. Handling experiments were performed to measure airborne particle concentration while handling nanoparticles in three fume hoods located in different buildings under a range of operating conditions. Nanoalumina and nanosilver were selected to perform handling experiments in the fume hoods. Air samples were also collected on polycarbonate membrane filters and particles were characterized by scanning electron microscopy. Handling tasks included transferring particles from beaker to beaker by spatula and by pouring. Measurement locations were the room background, the researcher's breathing zone and upstream and downstream from the handling location. Variable factors studied included hood design, transfer method, face velocity/sash location and material types. Airborne particle concentrations measured at breathing zone locations were analyzed to characterize exposure level. Statistics were used to test the correlation between data. The test results found that the handling of dry powders consisting of nano-sized particles inside laboratory fume hoods can result in a significant release of airborne nanoparticles from the fume hood into the laboratory environment and the researcher's breathing zone. Many variables were found to affect the extent of particle release including hood design, hood operation (sash height, face velocity

Global metabolomic profiling reveals an association of metal fume exposure and plasma unsaturated fatty acids.

Directory of Open Access Journals (Sweden)

Yongyue Wei

Full Text Available Welding-associated air pollutants negatively affect the health of exposed workers; however, their molecular mechanisms in causing disease remain largely unclear. Few studies have systematically investigated the systemic toxic effects of welding fumes on humans.To explore the effects of welding fumes on the plasma metabolome, and to identify biomarkers for risk assessment of welding fume exposure.The two-stage, self-controlled exploratory study included 11 boilermakers from a 2011 discovery panel and 8 boilermakers from a 2012 validation panel. Plasma samples were collected pre- and post-welding fume exposure and analyzed by chromatography/mass spectrometry.Eicosapentaenoic or docosapentaenoic acid metabolic changes post-welding were significantly associated with particulate (PM2.5 exposure (p<0.05. The combined analysis by linear mixed-effects model showed that exposure was associated with a statistically significant decline in metabolite change of eicosapentaenoic acid [β(95% CI = -0.013(-0.022 ≈ -0.004; p = 0.005], docosapentaenoic acid n3 [β(95% CI = -0.010(-0.018 ≈ -0.002; p = 0.017], and docosapentaenoic acid n6 [β(95% CI = -0.007(-0.013 ≈ -0.001; p = 0.021]. Pathway analysis identified an association of the unsaturated fatty acid pathway with exposure (p Study-2011 = 0.025; p Study-2012 = 0.021; p Combined = 0.009. The functional network built by these fatty acids and their interactive genes contained significant enrichment of genes associated with various diseases, including neoplasms, cardiovascular diseases, and lipid metabolism disorders.High-dose exposure of metal welding fumes decreases unsaturated fatty acids with an exposure-response relationship. This alteration in fatty acids is a potential biological mediator and biomarker for exposure-related health disorders.

Airborne nanoparticle exposures associated with the manual handling of nanoalumina and nanosilver in fume hoods

Energy Technology Data Exchange (ETDEWEB)

Tsai, Su-Jung, E-mail: candace.umass@gmail.com; Ada, Earl [University of Massachusetts Lowell, NSF Center for High-rate Nanomanufacturing (CHN) (United States); Isaacs, Jacqueline A. [Northeastern University, NSF Center for High-rate Nanomanufacturing (CHN) (United States); Ellenbecker, Michael J. [University of Massachusetts Lowell, NSF Center for High-rate Nanomanufacturing (CHN) (United States)

2009-01-15

Manual handling of nanoparticles is a fundamental task of most nanomaterial research; such handling may expose workers to ultrafine or nanoparticles. Recent studies confirm that exposures to ultrafine or nanoparticles produce adverse inflammatory responses in rodent lungs and such particles may translocate to other areas of the body, including the brain. An important method for protecting workers handling nanoparticles from exposure to airborne nanoparticles is the laboratory fume hood. Such hoods rely on the proper face velocity for optimum performance. In addition, several other hood design and operating factors can affect worker exposure. Handling experiments were performed to measure airborne particle concentration while handling nanoparticles in three fume hoods located in different buildings under a range of operating conditions. Nanoalumina and nanosilver were selected to perform handling experiments in the fume hoods. Air samples were also collected on polycarbonate membrane filters and particles were characterized by scanning electron microscopy. Handling tasks included transferring particles from beaker to beaker by spatula and by pouring. Measurement locations were the room background, the researcher's breathing zone and upstream and downstream from the handling location. Variable factors studied included hood design, transfer method, face velocity/sash location and material types. Airborne particle concentrations measured at breathing zone locations were analyzed to characterize exposure level. Statistics were used to test the correlation between data. The test results found that the handling of dry powders consisting of nano-sized particles inside laboratory fume hoods can result in a significant release of airborne nanoparticles from the fume hood into the laboratory environment and the researcher's breathing zone. Many variables were found to affect the extent of particle release including hood design, hood operation (sash height, face

Altered ion transport in normal human bronchial epithelial cells following exposure to chemically distinct metal welding fume particles

Energy Technology Data Exchange (ETDEWEB)

Fedan, Jeffrey S., E-mail: jsf2@cdc.gov; Thompson, Janet A.; Meighan, Terence G.; Zeidler-Erdely, Patti C.; Antonini, James M.

2017-07-01

Welding fume inhalation causes pulmonary toxicity, including susceptibility to infection. We hypothesized that airway epithelial ion transport is a target of fume toxicity, and investigated the effects of fume particulates from manual metal arc-stainless steel (MMA-SS) and gas metal arc-mild steel (GMA-MS) on ion transport in normal human bronchial epithelium (NHBE) cultured in air-interface. MMA-SS particles, more soluble than GMA-MS particles, contain Cr, Ni, Fe and Mn; GMA-MS particles contain Fe and Mn. MMA-SS or GMA-MS particles (0.0167–166.7 μg/cm{sup 2}) were applied apically to NHBEs. After 18 h transepithelial potential difference (V{sub t}), resistance (R{sub t}), and short circuit current (I{sub sc}) were measured. Particle effects on Na{sup +} and Cl¯ channels and the Na{sup +},K{sup +},2Cl¯-cotransporter were evaluated using amiloride (apical), 5-nitro-2-[(3-phenylpropyl)amino]benzoic acid (NPPB, apical), and bumetanide (basolateral), respectively. MMA-SS (0.0167–16.7 μg/cm{sup 2}) increased basal V{sub t}. Only 16.7 μg/cm{sup 2} GMA-MS increased basal V{sub t} significantly. MMA-SS or GMA-MS exposure potentiated I{sub sc} responses (decreases) to amiloride and bumetanide, while not affecting those to NPPB, GMA-MS to a lesser degree than MMA-SS. Variable effects on R{sub t} were observed in response to amiloride, and bumetanide. Generally, MMA-SS was more potent in altering responses to amiloride and bumetanide than GMA-MS. Hyperpolarization occurred in the absence of LDH release, but decreases in V{sub t}, R{sub t}, and I{sub sc} at higher fume particulate doses accompanied LDH release, to a greater extent for MMA-SS. Thus, Na{sup +} transport and Na{sup +},K{sup +},2Cl¯-cotransport are affected by fume exposure; MMA-MS is more potent than GMA-MS. Enhanced Na{sup +} absorption and decreased airway surface liquid could compromise defenses against infection. - Highlights: • Welding fume particle toxicity was investigated in human bronchial

Characterization of the Potential Hazards Associated with Potential RCRA Treatment Noncompliances

Energy Technology Data Exchange (ETDEWEB)

Clark, David Lewis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2015-08-20

The purpose of this document is to provide a hazard evaluation of the noncompliances and whether any new actions are required to mitigate potential risk to the worker or the public. In short, we have reviewed the noncompliances and have concluded that the possibility of exothermic reactions leading to radioactive release is not credible, and in one case, inconceivable, stemming from the fact that the majority fraction of the waste is compatible with organic absorbents and neutralizers. It is not expected that the noncompliances would generate or produce uncontrolled flammable fumes, gases, extreme heat, pressure, fire, explosions, or violent reactions.

Effects of some anaesthetics on honeybees: nitrous oxide, carbon dioxide, ammonium nitrate smoker fumes

Energy Technology Data Exchange (ETDEWEB)

Simpson, J

1954-08-01

Honeybees were apparently unaffected by atmospheric oxygen concentrations between 7% and 100%, and only became motionless when the oxygen concentration was less than 2%. The effects of nitrous oxide-oxygen mixtures differed little, if at all, from those nitrogen-oxygen mixtures. Bees were not visibly affected by carbon dioxide concentrations up to 10-15% but they became motionless if the concentration exceeded 40-45%. Fumes produced by adding ammonium nitrate to the fuel in a beekeeper's smoker were found to contain hydrogen cyanide or cyanogen. Their effectiveness as an anaesthetic may be due to this or to some unidentified component, but not to nitrous oxide. All three anaesthetics caused foraging bees to stop collecting pollen, and accelerated the retrogression of the pharyngeal glands of young bees. Anaesthesia of a few bees in a colony with nitrous oxide, carbon dioxide, or ammonium nitrate smoker fumes did not appear to inhibit their drift back to the original site when their hive was moved, nor was any reduction in drifting observed when a whole colony was moved while anaesthetized with ammonium nitrate smoker fumes. 4 tables.

Effectiveness of amorphous silica encapsulation technology on welding fume particles and its impact on mechanical properties of welds

International Nuclear Information System (INIS)

Wang, Jun; Wu, Chang-Yu; Franke, Gene

2014-01-01

Highlights: • A novel welding shielding gas containing a silica precursor. • Up to 76% of the welding fume particles encapsulated in an amorphous silica layer. • No statistical difference between different types of welds in mechanical tests. • Can potentially reduce the toxicity of welding fume particles. - Abstract: Stainless steel welding generates nano-sized fume particles containing toxic metals which may cause serious health effects upon inhalation. The objective of this study was to investigate the effectiveness of an amorphous silica encapsulation (ASE) technology by evaluating its silica coating efficiency (SCE), particle morphology, and its impact on the weld’s mechanical properties. Tetramethylsilane (TMS) added to the welding shielding gas decomposed at the high-temperature arc zone to enable the silica coating. Collected welding fume particles were digested by two acid mixtures with different degrees of silica solubility, and the measured mass differences in the digests were used to determine the SCE. The SCEs were around 48–64% at the low and medium primary shielding gas flow rates. The highest SCE of 76% occurred at the high shielding gas flow rate (30 Lpm) with a TMS carrier gas flow of 0.64 Lpm. Transmission electron microscopy (TEM) images confirmed the amorphous silica layer on the welding fume particles at most gas flow rates, as well as abundant stand-alone silica particles formed at the high gas flow rate. Metallography showed that welds from the baseline and from the ASE technology were similar except for a tiny crack found in one particular weld made with the ASE technology. Tensile tests showed no statistical difference between the baseline and the ASE welds. All the above test results confirm that welding equipment retrofitted with the ASE technology has the potential to effectively address the toxicity problem of welding fume particles without affecting the mechanical properties of the welds

Influence of silica fume on the strength of high strength concrete

International Nuclear Information System (INIS)

Akram, T.; Memon, S.A.; Khan, S.A.

2007-01-01

HSC (High Strength Concrete) does not become evident by a sudden change in the behavior of 'ordinary strength' concrete. There is a gradual effect that becomes more noticeable when the strength level exceeds about 40-45 MPa. There cannot be a precise level of strength which defines this change in effect. The effects are on strength and workability, requiring us to take into account in our mix proportioning, the ramifications of fineness of cement on workability and of type of aggregate and aggregate/cement ratio on strength. In fact, the selection of materials becomes more critical as the concrete strength increases and that if very high strength is required (100 MPa and higher), relatively few materials may be suitable. An experimental investigation is carried out to evaluate the feasibility of producing HSC using locally available materials and to study the influence of silica fume on the strength of HSC. The main variables in this research is amount of silica fume. The parameters that are kept constant are the amount of cement equal to 580 kg/m3, dosage of HRWRA (High Range Water Reducing Admictures) equal to 4 % by weight of cementitious materials and the ratio of fine aggregate to coarse aggregate (1:2.3). Test results revealed that it is feasible to produce HSC using locally available materials. The optimum percentage of silica fume was found to be 15 % by weight of cement. (author)

Effect of silica fume on the characterization of the geopolymer materials

Science.gov (United States)

Khater, Hisham M.

2013-12-01

The influence of silica fume (SF) addition on properties of geopolymer materials produced from alkaline activation of alumino-silicates metakaolin and waste concrete produced from demolition works has been studied through the measurement of compressive strength, Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy (SEM) analysis. Alumino-silicate materials are coarse aggregate included waste concrete and fired kaolin (metakaolin) at 800°C for 3 h, both passing a sieve of 90 μm. Mix specimens containing silica fume were prepared at water/binder ratios in a range of 0.30 under water curing. The used activators are an equal mix of sodium hydroxide and silicate in the ratio of 3:3 wt.%. The control geopolymer mix is composed of metakaolin and waste concrete in an equal mix (50:50, wt.%). Waste concrete was partially replaced by silica fume by 1 to 10 wt.%. The results indicated that compressive strengths of geopolymer mixes incorporating SF increased up to 7% substitution and then decreased up to 10% but still higher than that of the control mix. Results indicated that compressive strengths of geopolymer mixes incorporating SF increases up to 7% substitution and then decreases up to 10% but still higher than the control mix, where 7% SF-digested calcium hydroxide (CH) crystals, decreased the orientation of CH crystals, reduced the crystal size of CH gathered at the interface, and improved the interface more effectively.

Increased levels of oxidative DNA damage attributable to cooking-oil fumes exposure among cooks.

Science.gov (United States)

Ke, Yuebin; Cheng, Jinquan; Zhang, Zhicheng; Zhang, Renli; Zhang, Zhunzhen; Shuai, Zhihong; Wu, Tangchun

2009-07-01

Previous investigations have indicated that cooks are exposed to polycyclic aromatic hydrocarbons (PAHs) from cooking-oil fumes. However, Emission of PAH and their carcinogenic potencies from cooking oil fumes sources have not been investigated among cooks. To investigate the urinary excretion of a marker for oxidative DNA damage, 8-hydroxydeoxyguanosine (8-OHdG), in different groups of cooks and different exposure groups, and to study the association between 8-OHdG and 1-hydroxypyrene(1-OHP), a biological marker for PAH exposure. Urine samples were collected from different groups of cooks (n = 86) and from unexposed controls (n = 36); all were male with similar age and smoking habits. The health status, occupational history, smoking, and alcohol consumption 24 h prior to sampling was estimated from questionnaires. The urine samples were frozen for later analyses of 8-OHdG and 1-OHP levels by high-performance liquid chromatography. Excretion in urine of 8-OHdG was similar for controls (mean 1.2micromol/mol creatinine, n = 36), and for those who had been in the kitchen with an exhaust-hood operating (mean 1.5micromol/mol creatinine, n = 45). Cooks exposed to cooking-oil fumes without exhaust-hood operation had significantly increased excretion of 8-OHdG (mean 2.3micromol/mol creatinine, n = 18), compared with controls. The urinary levels of ln 1-OHP and ln 8-OHdG were still significantly correlated in a multiple regression analysis. The results indicate that exposure to PAH or possibly other compounds in cooking-oil fumes may cause oxidative DNA damage.

Profiling stainless steel welding processes to reduce fume emissions, hexavalent chromium emissions and operating costs in the workplace.

Science.gov (United States)

Keane, Michael; Siert, Arlen; Stone, Samuel; Chen, Bean T

2016-01-01

Nine gas metal arc welding (GMAW) processes for stainless steel were assessed for fume generation rates, fume generation rates per g of electrode consumed, and emission rates for hexavalent chromium (Cr(6+)). Elemental manganese, nickel, chromium, iron emissions per unit length of weld, and labor plus consumables costs were similarly measured. Flux-cored arc welding and shielded metal arc (SMAW) processes were also studied. The objective was to identify the best welding processes for reducing workplace exposures, and estimate costs for all processes. Using a conical chamber, fumes were collected, weighed, recovered, and analyzed by inductively coupled atomic emission spectroscopy for metals, and by ion chromatography for Cr(6+). GMAW processes used were Surface Tension Transfer, Regulated Metal Deposition, Cold Metal Transfer, short-circuit, axial spray, and pulsed spray modes. Flux-cored welding used gas shielding; SMAW used E308 rods. Costs were estimated as dollars per m length of a ¼ in (6.3 mm) thick horizontal butt weld; equipment costs were estimated as ratios of new equipment costs to a 250 ampere capacity SMAW welding machine. Results indicate a broad range of fume emission factors for the processes studied. Fume emission rates per g of electrode were lowest for GMAW processes such as pulsed-spray mode (0.2 mg/g), and highest for SMAW (8 mg fume/g electrode). Emission rates of Cr(6+) ranged from 50-7800 µg/min, and Cr(6+) generation rates per g electrode ranged from 1-270 µg/g. Elemental Cr generation rates spanned 13-330 µg/g. Manganese emission rates ranged from 50-300 µg/g. Nickel emission rates ranged from 4-140 µg/g. Labor and consumables costs ranged from $3.15 (GMAW pulsed spray) to $7.40 (SMAW) per meter of finished weld, and were measured or estimated for all 11 processes tested. Equipment costs for some processes may be as much as five times the cost of a typical SMAW welding machine. The results show that all of the GMAW processes in this

Effect Of Inhalation Exposure To Kerosene And Petrol-Fumes On ...

African Journals Online (AJOL)

Changes in total body weight, some anaemia-diagnostic indices (haematocrit or packed cell volume (PCV), haemoglobin (Hb) and total serum protein) were determined in rats (Wistar albino strain) after 2 weeks of 4 hours daily inhalation exposure to ungraded concentrations of kerosene and petrol fumes. The results ...

Effect of plasticizer and fumed silica on ionic conductivity behaviour

Indian Academy of Sciences (India)

The effect of addition of propylene carbonate (PC) and nano-sized fumed silica on the ionic conductivity behaviour of proton conducting polymer electrolytes containing different concentrations of hexafluorophosphoric acid (HPF6) in polyethylene oxide (PEO) has been studied. The addition of PC results in an increase in ...

Exposure to welding fumes increases lung cancer risk among light smokers but not among heavy smokers: evidence from two case-control studies in Montreal.

Science.gov (United States)

Vallières, Eric; Pintos, Javier; Lavoué, Jérôme; Parent, Marie-Élise; Rachet, Bernard; Siemiatycki, Jack

2012-08-01

We investigated relationships between occupational exposure to gas and arc welding fumes and the risk of lung cancer among workers exposed to these agents throughout the spectrum of industries. Two population-based case-control studies were conducted in Montreal. Study I (1979-1986) included 857 cases and 1066 controls, and Study II (1996-2001) comprised 736 cases and 894 controls. Detailed job histories were obtained by interview and evaluated by an expert team of chemist-hygienists to estimate degree of exposure to approximately 300 substances for each job. Gas and arc welding fumes were among the agents evaluated. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) of lung cancer using logistic regression, adjusting for smoking history and other covariates. The two studies provided similar results, so a pooled analysis was conducted. Among all subjects, no significant association was found between lung cancer and gas welding fumes (OR = 1.1; 95% CI = 0.9-1.4) or arc welding fumes (OR = 1.0; 95% CI = 0.8-1.2). However, when restricting attention to light smokers, there was an increased risk of lung cancer in relation to gas welding fumes (OR = 2.9; 95% CI = 1.7-4.8) and arc welding fumes (OR = 2.3; 95% CI = 1.3-3.8), with even higher OR estimates among workers with the highest cumulative exposures. In conclusion, there was no detectable excess risk of lung cancer due to welding fumes among moderate to heavy smokers; but among light smokers we found an excess risk related to both types of welding fumes.

Study on properties of mortar using silica fume and ground blast furnace slag. Silica fume oyobi koro slag funmatsu wo mochiita mortar no tokusei ni kansuru kenkyu

Energy Technology Data Exchange (ETDEWEB)

Shiiba, H; Honda, S; Araki, A [Fukuoka University, Fukuoka (Japan). Faculty of Engineering

1992-09-01

The effect of silica fume and ground blast furnace slag in concrete on the content of superplasticizer, and dynamic properties of hardened mortar with such admixtures were studied experimentally. Although the dependence of a flow value on the superplasticizer was dominated by kinds of superplasticizers, blast furnace slag enhanced the flow value resulting in a high fluidity. Adsorption of superplasticizers onto admixtures was dependent on kinds of superplasticizers, and adsorption onto blast furnace slag was 1.3-2 times that onto normal Portland cement (NPC). The compressive strength of mortar increased by mixing admixtures, while the bending strength was enhanced only by mixing silica fume. Mixing mortar was lower in dynamic elastic modulus than NPC mortar at the same compressive strength, and the velocity of supersonic wave in mortar was scarcely affected by mixing. 11 refs., 14 figs., 3 tabs.

Increase in oxidative stress levels following welding fume inhalation: a controlled human exposure study.

Science.gov (United States)

Graczyk, Halshka; Lewinski, Nastassja; Zhao, Jiayuan; Sauvain, Jean-Jacques; Suarez, Guillaume; Wild, Pascal; Danuser, Brigitta; Riediker, Michael

2016-06-10

Tungsten inert gas (TIG) welding represents one of the most widely used metal joining processes in industry. It has been shown to generate a large majority of particles at the nanoscale and to have low mass emission rates when compared to other types of welding. Despite evidence that TIG fume particles may produce reactive oxygen species (ROS), limited data is available for the time course changes of particle-associated oxidative stress in exposed TIG welders. Twenty non-smoking male welding apprentices were exposed to TIG welding fumes for 60 min under controlled, well-ventilated settings. Exhaled breathe condensate (EBC), blood and urine were collected before exposure, immediately after exposure, 1 h and 3 h post exposure. Volunteers participated in a control day to account for oxidative stress fluctuations due to circadian rhythm. Biological liquids were assessed for total reducing capacity, hydrogen peroxide (H2O2), malondialdehyde (MDA), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) concentrations at each time point. A linear mixed model was used to assess within day and between day differences. Significant increases in the measured biomarkers were found at 3 h post exposure. At 3 h post exposure, we found a 24 % increase in plasma-H2O2 concentrations ([95%CI: 4 % to 46 %], p = 0.01); a 91 % increase in urinary-H2O2 ([2 % to 258 %], p = 0.04); a 14 % increase in plasma-8-OHdG ([0 % to 31 %], p = 0.049); and a 45 % increase in urinary-8-OHdG ([3 % to 105 %], p = 0.03). Doubling particle number concentration (PNC) exposure was associated with a 22 % increase of plasma-8-OHdG at 3 h post exposure (p = 0.01). A 60-min exposure to TIG welding fume in a controlled, well-ventilated setting induced acute oxidative stress at 3 h post exposure in healthy, non-smoking apprentice welders not chronically exposed to welding fumes. As mass concentration of TIG welding fume particles is very low when compared to other types of welding, it is

The Effect of Aging and Silanization on the Mechanical Properties of Fumed Silica-based Dental Composite

Directory of Open Access Journals (Sweden)

Khaje S

2015-12-01

Full Text Available Statement of Problem: Mechanical strength and durability of dental composites are the main topics studied in this field of science today. This study examined fumed silica-based composite as a strong and durable restorative material through flexural and cycling test methods. Objectives: The purpose of this study was to evaluate the effect of silanization, ageing, cycling and hybridizing on mechanical properties of fumed silica-based resin composite. Materials and Methods: Composites were made of light-cured copolymer based on Bisphenol A glycolmethacrylate (Bis-GMA and Triethylene glycoldimethacrylate (TEGDMA at proportion of 50:50 which reinforced by fumed silica filler. For each composite sample, 5 specimen bars were made using Teflon mould (2 x 2 x 25 mm3. The samples with 12 wt% fumed silica (FS were considered as a base line group. The samples were exposed to cyclic cold water (FS-CCW and hot water (FS-CHW. The effect of silanization and adding more filler was studied together with samples containing 12 wt% (FS-S (12, 16 wt% (FS-S (16 and 20 wt% (FS-S (20 fumed silica filler. The filler was silanized with (γ-MPS. The degree of conversion was assessed with Fourier Transform Infra-Red spectroscopy. Flexural properties were evaluated with the Three-Point Bending test. Flexural data were analyzed with Excel software. Hardness was measured with an Atomic Force Microscope (AFM. Results: The degree of conversion of the resin reached 74% within 24 hrs. Salinization allowed more filler to be wetted by resin. Addition of silanized particles from sample FS-S (12 to sample FS-S (20 improved the mechanical strength. Hybridizing fumed silica with nano-silica (FS-N had no significant effect on the strength, but nano-hardness improved greatly. Ageing and cycling had adverse effects on the strength of the sample FS. The flexural strength of FS-CHW was 72% less than FS sample. Conclusions: Sample FS-N with low diluent and filler percentage complied with the

Health hazards of cement dust

International Nuclear Information System (INIS)

Meo, Sultan A.

2004-01-01

ven in the 21st century, millions of people are working daily in a dusty environment. They are exposed to different types of health hazards such as fume, gases and dust, which are risk factors in developing occupational disease. Cement industry is involved in the development of structure of this advanced and modern world but generates dust during its production. Cement dust causes lung function impairment, chronic obstructive lung disease, restrictive lung disease, pneumoconiosis and carcinoma of the lungs, stomach and colon. Other studies have shown that cement dust may enter into the systemic circulation and thereby reach the essentially all the organs of body and affects the different tissues including heart, liver, spleen, bone, muscles and hairs and ultimately affecting their micro-structure and physiological performance. Most of the studies have been previously attempted to evaluate the effects of cement dust exposure on the basis of spirometry or radiology, or both. However, collective effort describing the general effects of cement dust on different organ and systems in humans or animals, or both has not been published. Therefore, the aim of this review is to gather the potential toxic effects of cement dust and to minimize the health risks in cement mill workers by providing them with information regarding the hazards of cement dust. (author)

Blunted behavioral and c Fos responses to acidic fumes in the African naked mole-rat.

Science.gov (United States)

LaVinka, Pamela Colleen; Park, Thomas J

2012-01-01

Acidosis in the skin triggers activation of pain pathways and behaviors indicative of pain in vertebrates. The exception is the naked mole-rat, the only known vertebrate to show physiological and behavioral insensitivity to acid pain in the skin. The goal of the present study was to determine behavioral and physiological responses of this species to airborne acidic fumes, which would be expected to affect the trigeminal pain pathway in other species. Behaviorally, naked mole-rats did not avoid fumes from moderately high concentrations of acetic acid (10 and 20%), and c Fos labeling showed no increase in activity in the trigeminal nuclei and nucleus tractus solitarius. In contrast, these concentrations triggered behavioral aversion and increased Fos activity in other laboratory rodents. For a very high concentration of acetic acid (50%), naked mole-rats showed significant avoidance behavior and increased Fos labeling in the nucleus tractus solitarius caudal region, which receives vagal chemosensory information. However, there was no increase in trigeminal labeling, and in fact, activity significantly decreased. This pattern is opposite of that associated with another irritant, ammonia fumes, which elicited an increase in trigeminal but not nucleus tractus solitarius Fos labeling, and no behavioral avoidance. Behavioral avoidance of acidic fumes, but no increased labeling in the trigeminal pain nucleus is consistent with the notion of adaptations to blunt acid pain, which would be advantageous for naked mole-rats as they normally live under chronically high levels of acidosis-inducing CO(2).

Blunted behavioral and c Fos responses to acidic fumes in the African naked mole-rat.

Directory of Open Access Journals (Sweden)

Pamela Colleen LaVinka

Full Text Available Acidosis in the skin triggers activation of pain pathways and behaviors indicative of pain in vertebrates. The exception is the naked mole-rat, the only known vertebrate to show physiological and behavioral insensitivity to acid pain in the skin. The goal of the present study was to determine behavioral and physiological responses of this species to airborne acidic fumes, which would be expected to affect the trigeminal pain pathway in other species. Behaviorally, naked mole-rats did not avoid fumes from moderately high concentrations of acetic acid (10 and 20%, and c Fos labeling showed no increase in activity in the trigeminal nuclei and nucleus tractus solitarius. In contrast, these concentrations triggered behavioral aversion and increased Fos activity in other laboratory rodents. For a very high concentration of acetic acid (50%, naked mole-rats showed significant avoidance behavior and increased Fos labeling in the nucleus tractus solitarius caudal region, which receives vagal chemosensory information. However, there was no increase in trigeminal labeling, and in fact, activity significantly decreased. This pattern is opposite of that associated with another irritant, ammonia fumes, which elicited an increase in trigeminal but not nucleus tractus solitarius Fos labeling, and no behavioral avoidance. Behavioral avoidance of acidic fumes, but no increased labeling in the trigeminal pain nucleus is consistent with the notion of adaptations to blunt acid pain, which would be advantageous for naked mole-rats as they normally live under chronically high levels of acidosis-inducing CO(2.

Inhalation of gas metal arc-stainless steel welding fume promotes lung tumorigenesis in A/J mice.

Science.gov (United States)

Falcone, Lauryn M; Erdely, Aaron; Meighan, Terence G; Battelli, Lori A; Salmen, Rebecca; McKinney, Walter; Stone, Samuel; Cumpston, Amy; Cumpston, Jared; Andrews, Ronnee N; Kashon, Michael; Antonini, James M; Zeidler-Erdely, Patti C

2017-08-01

Epidemiologic studies suggest an increased risk of lung cancer with exposure to welding fumes, but controlled animal studies are needed to support this association. Oropharyngeal aspiration of collected "aged" gas metal arc-stainless steel (GMA-SS) welding fume has been shown by our laboratory to promote lung tumor formation in vivo using a two-stage initiation-promotion model. Our objective in this study was to determine whether inhalation of freshly generated GMA-SS welding fume also acts as a lung tumor promoter in lung tumor-susceptible mice. Male A/J mice received intraperitoneal (IP) injections of corn oil or the chemical initiator 3-methylcholanthrene (MCA; 10 µg/g) and 1 week later were exposed by whole-body inhalation to air or GMA-SS welding aerosols for 4 h/d × 4 d/w × 9 w at a target concentration of 40 mg/m 3 . Lung nodules were enumerated at 30 weeks post-initiation. GMA-SS fume significantly promoted lung tumor multiplicity in A/J mice initiated with MCA (16.11 ± 1.18) compared to MCA/air-exposed mice (7.93 ± 0.82). Histopathological analysis found that the increased number of lung nodules in the MCA/GMA-SS group were hyperplasias and adenomas, which was consistent with developing lung tumorigenesis. Metal deposition analysis in the lung revealed a lower deposited dose, approximately fivefold compared to our previous aspiration study, still elicited a significant lung tumorigenic response. In conclusion, this study demonstrates that inhaling GMA-SS welding fume promotes lung tumorigenesis in vivo which is consistent with the epidemiologic studies that show welders may be at an increased risk for lung cancer.

Problem of industrial fumes in the forested valleys of Savoy

Energy Technology Data Exchange (ETDEWEB)

Bossavy, J

1962-01-01

A study of injury to forest trees in the Maurienne valley, caused by F in the fumes from aluminum factories was made. Of the local conifers, Pinus sylvestris was the most susceptible, followed by Picea abies and Abies alba; Larch has so far proved resistant, as have broadleaved deciduous species.

Physicochemical and toxicological characteristics of welding fume derived particles generated from real time welding processes.

Science.gov (United States)

Chang, Cali; Demokritou, Philip; Shafer, Martin; Christiani, David

2013-01-01

Welding fume particles have been well studied in the past; however, most studies have examined welding fumes generated from machine models rather than actual exposures. Furthermore, the link between physicochemical and toxicological properties of welding fume particles has not been well understood. This study aims to investigate the physicochemical properties of particles derived during real time welding processes generated during actual welding processes and to assess the particle size specific toxicological properties. A compact cascade impactor (Harvard CCI) was stationed within the welding booth to sample particles by size. Size fractionated particles were extracted and used for both off-line physicochemical analysis and in vitro cellular toxicological characterization. Each size fraction was analyzed for ions, elemental compositions, and mass concentration. Furthermore, real time optical particle monitors (DustTrak™, TSI Inc., Shoreview, Minn.) were used in the same welding booth to collect real time PM2.5 particle number concentration data. The sampled particles were extracted from the polyurethane foam (PUF) impaction substrates using a previously developed and validated protocol, and used in a cellular assay to assess oxidative stress. By mass, welding aerosols were found to be in coarse (PM 2.5–10), and fine (PM 0.1–2.5) size ranges. Most of the water soluble (WS) metals presented higher concentrations in the coarse size range with some exceptions such as sodium, which presented elevated concentration in the PM 0.1 size range. In vitro data showed size specific dependency, with the fine and ultrafine size ranges having the highest reactive oxygen species (ROS) activity. Additionally, this study suggests a possible correlation between welders' experience, the welding procedure and equipment used and particles generated from welding fumes. Mass concentrations and total metal and water soluble metal concentrations of welding fume particles may be

Exposure to welding fumes increases lung cancer risk among light smokers but not among heavy smokers: evidence from two case–control studies in Montreal

Science.gov (United States)

Vallières, Eric; Pintos, Javier; Lavoué, Jérôme; Parent, Marie-Élise; Rachet, Bernard; Siemiatycki, Jack

2012-01-01

We investigated relationships between occupational exposure to gas and arc welding fumes and the risk of lung cancer among workers exposed to these agents throughout the spectrum of industries. Two population-based case–control studies were conducted in Montreal. Study I (1979–1986) included 857 cases and 1066 controls, and Study II (1996–2001) comprised 736 cases and 894 controls. Detailed job histories were obtained by interview and evaluated by an expert team of chemist–hygienists to estimate degree of exposure to approximately 300 substances for each job. Gas and arc welding fumes were among the agents evaluated. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) of lung cancer using logistic regression, adjusting for smoking history and other covariates. The two studies provided similar results, so a pooled analysis was conducted. Among all subjects, no significant association was found between lung cancer and gas welding fumes (OR = 1.1; 95% CI = 0.9–1.4) or arc welding fumes (OR = 1.0; 95% CI = 0.8–1.2). However, when restricting attention to light smokers, there was an increased risk of lung cancer in relation to gas welding fumes (OR = 2.9; 95% CI = 1.7–4.8) and arc welding fumes (OR = 2.3; 95% CI = 1.3–3.8), with even higher OR estimates among workers with the highest cumulative exposures. In conclusion, there was no detectable excess risk of lung cancer due to welding fumes among moderate to heavy smokers; but among light smokers we found an excess risk related to both types of welding fumes. PMID:23342253

Comparative study on strength properties of cement mortar by partial replacement of cement with ceramic powder and silica fume

Science.gov (United States)

Himabindu, Ch.; Geethasri, Ch.; Hari, N.

2018-05-01

Cement mortar is a mixture of cement and sand. Usage of high amount of cement increases the consumption of natural resources and electric power. To overcome this problem we need to replace cement with some other material. Cement is replaced with many other materials like ceramic powder, silica fume, fly ash, granulated blast furnace slag, metakaolin etc.. In this research cement is replaced with ceramic powder and silica fume. Different combinations of ceramic powder and silica fume in cement were replaced. Cement mortar cubes of 1:3 grade were prepared. These cubes were cured under normal water for 7 days, 14days and 28 days. Compressive strength test was conducted for all mixes of cement mortar cubes.

Autogenous Deformation and Change of the Relative Humidity in Silica Fume-Modified Cement Paste

DEFF Research Database (Denmark)

Jensen, Ole mejlhede; Hansen, Per Freiesleben

1996-01-01

Even during sealed curing and at a constant temperature a hardening cement paste will deform and the relative humidity within its pores will lower. This autogenous deformation and autogenous relative humidity change may be so significant that the cement paste cracks if the deformation is restrained....... This article focuses on the influence of silica fume addition on autogenous deformation and autogenous relative humidity change. Continuous measurement of autogenous deformation and autogenous relative humidity change for more than 1 year and 1« years, respectively, was performed. The investigations show...... thatsilica fume addition markedly increases the autogenous shrinkage as well as the autogenous relative humidity change....

Phase analysis of fume during arc weld brazing of steel sheets with protective coatings

Directory of Open Access Journals (Sweden)

J. Matusiak

2016-04-01

Full Text Available The article presents the results of research of the phase identification and of the quantitative phase analysis of fume generated during Cold Metal Transfer (CMT, ColdArc and Metal Inert Gas / Metal Active Gas (MIG / MAG weld brazing. Investigations were conducted for hot - dip coated steel sheets with zinc (Zn and zinc-iron (Zn - Fe alloy coatings. Arc shielding gases applied during the research-related tests were Ar + O2, Ar + CO2, Ar + H2 and Ar + CO2 + H2 gas mixtures. The analysis of the results covers the influence of the chemical composition of shielding gas on the chemical composition of welding fume.

Effect of paint fumes on histoarchitecture of the testes of adult male ...

African Journals Online (AJOL)

abdominal incision was performed after which one testis was received from each rats, preserved in 10% formal saline and further processed for histological study using Hematoxylin and eosin technique. Results: The testes of the paint fumes ...

Effect of Silica Fume on two-stage Concrete Strength

Science.gov (United States)

Abdelgader, H. S.; El-Baden, A. S.

2015-11-01

Two-stage concrete (TSC) is an innovative concrete that does not require vibration for placing and compaction. TSC is a simple concept; it is made using the same basic constituents as traditional concrete: cement, coarse aggregate, sand and water as well as mineral and chemical admixtures. As its name suggests, it is produced through a two-stage process. Firstly washed coarse aggregate is placed into the formwork in-situ. Later a specifically designed self compacting grout is introduced into the form from the lowest point under gravity pressure to fill the voids, cementing the aggregate into a monolith. The hardened concrete is dense, homogeneous and has in general improved engineering properties and durability. This paper presents the results from a research work attempt to study the effect of silica fume (SF) and superplasticizers admixtures (SP) on compressive and tensile strength of TSC using various combinations of water to cement ratio (w/c) and cement to sand ratio (c/s). Thirty six concrete mixes with different grout constituents were tested. From each mix twenty four standard cylinder samples of size (150mm×300mm) of concrete containing crushed aggregate were produced. The tested samples were made from combinations of w/c equal to: 0.45, 0.55 and 0.85, and three c/s of values: 0.5, 1 and 1.5. Silica fume was added at a dosage of 6% of weight of cement, while superplasticizer was added at a dosage of 2% of cement weight. Results indicated that both tensile and compressive strength of TSC can be statistically derived as a function of w/c and c/s with good correlation coefficients. The basic principle of traditional concrete, which says that an increase in water/cement ratio will lead to a reduction in compressive strength, was shown to hold true for TSC specimens tested. Using a combination of both silica fume and superplasticisers caused a significant increase in strength relative to control mixes.

X-ray fluorescence analysis of welding fume particles

International Nuclear Information System (INIS)

Carsey, T.P.

1982-01-01

A commercial standard filter set and two laboratory-made standard filter sets are compared via the analysis of generated welding fume samples by X-ray fluorescence. The latter standards are made by (1) hydrophobic-edge membrane filters spiked with prepared metal ion solutions, and (2) filters through which a dispersion of metal oxide powder in isopropanol has been drawn. The results are presented in table form. Precision (Pre) is the relative standard deviation of the six samples. Four main conclusions are enumerated

Survey of potential health and safety hazards of commercial-scale ethanol production facilities

Energy Technology Data Exchange (ETDEWEB)

Watson, A.P.; Smith, J.G.; Elmore, J.L.

1982-04-01

Generic safety and health aspects of commercial-scale (60 to 600 million L/y) anhydrous ethanol production were identified. Several common feedstocks (grains, roots and fibers, and sugarcane) and fuels (coal, natural gas, wood, and bagasse) were evaluated throughout each step of generic plant operation, from initial milling and sizing through saccharification, fermentation, distillation, and stillage disposal. The fermentation, digestion, or combustion phases are not particularly hazardous, although the strong acids and bases used for hydrolysis and pH adjustment should be handled with the same precautions that every industrial solvent deserves. The most serious safety hazard is that of explosion from grain dust or ethanol fume ignition and boiler/steam line overpressurization. Inhalation of ethanol and carbon dioxide vapors may cause intoxication or asphyxiation in unventilated areas, which could be particularly hazardous near equipment controls and agitating vats. Contact with low-pressure process steam would produce scalding burns. Benzene, used in stripping water from ethanol in the final distillation column, is a suspected leukemogen. Substitution of this fluid by alternative liquids is addressed.

Mass spectrometric investigation of synthetic glycoside of muramyl dipeptide immobilized on fumed silica surface

Energy Technology Data Exchange (ETDEWEB)

Kulik, Tetiana V., E-mail: tanyakulyk@gala.net [O.O. Chuiko Institute of Surface Chemistry, National Academy of Sciences of Ukraine, 17 Generala Naumova Str., Kyiv 03164 (Ukraine); Azizova, Liana R., E-mail: liana_azizova@ukr.net [O.O. Chuiko Institute of Surface Chemistry, National Academy of Sciences of Ukraine, 17 Generala Naumova Str., Kyiv 03164 (Ukraine); Palyanytsya, Borys B. [O.O. Chuiko Institute of Surface Chemistry, National Academy of Sciences of Ukraine, 17 Generala Naumova Str., Kyiv 03164 (Ukraine); Zemlyakov, Alexander E.; Tsikalova, Victoria N. [Vernadsky Tauric National University, pr. Akademika Vernadskogo 4, Simferopol, 95007 (Ukraine)

2010-05-25

N-Acetylmuramyl-L-alanyl-D-isoglutamine or muramyl dipeptide is a cleavage product of peptidoglycan by lysozyme. This study explored the use of the temperature-programmed desorption mass spectrometry (TPDMS) in analysis of glycoside of muramyl dipeptide: O-{l_brace}(4-tert-butylcyclohexyl)-2-acetamido-2, 3-dideoxy-{beta}-D-glucopyranoside-3-yl{r_brace}-D-lactoyl-L-alanyl-D-isoglutamine (MDP) on the surface of fumed silica. Stages of pyrolysis of MDP in condensed state and on the silica surface have been determined. Three stages have been clear identified under pyrolysis of MDP on the silica surface. Kinetic parameters of thermal reactions on the fumed silica surface and in the condensed state have been calculated.

Controversial effects of fumed silica on the curing and thermomechanical properties of epoxy composites

Directory of Open Access Journals (Sweden)

2010-06-01

Full Text Available The effect of fumed silica on the curing of a trimethylolpropane epoxy resin was investigated by thermal analysis methods like Differential Scanning Calorimetry (DSC, and Dynamic Mechanical Analysis (DMA. The fumed silica used here is a by-product of the silicon and ferrosilicon industry, consisting of micro and nanosized particles. Both the curing reaction and the properties of the obtained composites were affected by the filler content. Different trends were observed for filler contents above and below the 30 wt%. Up to 30 wt%, the behaviour can be explained as a predominantly agglomeration effect. For 30 wt% and higher filler contents, single particles seem to play a more important role.

Acute Inhalation Exposure to Titanium Ethanolate as a Possible Cause of Metal Fume Fever

Directory of Open Access Journals (Sweden)

M Ahmadimanesh

2014-04-01

Full Text Available Occupational inhalation exposure to noxious agents is not uncommon. Herein, we present a 26-year-old male student who had accidental acute inhalation exposure to a large quantity of titanium ethanolate and hydrogen chloride in chemistry lab. He was referred to the emergency department of our hospital with low-grade fever, dyspnea, headache, fatigue and myalgia. After 24 hrs of symptomatic treatment (oxygen therapy and acetaminophen, the fever was subsided and the patient discharged home in a good clinical condition. The presented symptoms could be interpreted as a form of metal fume fever. It can therefore be concluded that organo-metallic compound of titanium metal may have the potential to produce metal fume fever in human.

Udvikling af vejledningspraksis i kurser for undervisere i brugen af blended learning-aktiviteter

DEFF Research Database (Denmark)

Stenalt, Maria Hvid; Wichmann-Hansen, Gitte; Rossen, Dorte Sidelmann

Hvert semester tilbyder Center for Undervisning og Læring (CUL) ved School of Business and Social Sciences ved Aarhus Universitet et 1-årig langt kompetenceudviklingsforløb i brugen af blended learning for lektorer og professorer. I løbet af denne periode skal deltagerne gennemføre et indledende...... blended learning-kursusforløb på 5 uger efterfulgt af en udviklings- og afprøvningsfase. Som afslutning skal deltagerne skrive en refleksionsrapport. Forløbet indebærer to vejledningsmøder med en eller flere af de undervisningsudviklere fra CUL, der er ansvarlige for forløbet: 1) Et individuelt...... vejledningsmøde, hvor deltagerne skal finde frem til, hvordan de vil eller kan omlægge deres undervisning til blended learning og 2) et kollektivt vejledningsmøde efter første udviklingsfase, hvor deltagerne modtager feedback på deres igangværende udviklingstiltag fra gruppemedlemmer og undervisningsudviklere. Et...

High Strength Lightweight Concrete Made with Ternary Mixtures of Cement-Fly Ash-Silica Fume and Scoria as Aggregate

OpenAIRE

YAŞAR, Ergül; ATIŞ, Cengiz Duran; KILIÇ, Alaettin

2014-01-01

This paper presents part of the results of an ongoing laboratory study carried out to design a structural lightweight high strength concrete (SLWHSC) made with and without ternary mixtures of cement-fly ash-silica fume. In the mixtures, lightweight basaltic-pumice (scoria) aggregate was used. A concrete mixture made with lightweight scoria, and another lightweight scoria concrete mixture incorporating 20% fly ash and 10% silica fume as a cement replacement, were prepared. Two normal...

Properties of silica fume procured from natural diatomite and its usage in the production of vacuum insulation panels

OpenAIRE

V.P. Selyaev; V.A. Neverov; O.G. Mashtaev; A.V. Kolotushkin

2013-01-01

The article shows the results of the research of silica fume particles procured from diatomite from Atemar deposit by means of separating silicic acid from colloidal dissolved state into the sediment. The objective of the work was to define thermal-physical and structural characteristics of the silica fume. The research included IR-spectrometry, granulometry, thermal gravimetric analysis, X-ray structural analysis, optical microscopy, and small angle X-Ray scattering. As a result of the resea...

Evaluation of the Pulmonary Toxicity of a Fume Generated from a Nickel-, Copper-Based Electrode to be Used as a Substitute in Stainless Steel Welding

Science.gov (United States)

Antonini, James M; Badding, Melissa A; Meighan, Terence G; Keane, Michael; Leonard, Stephen S; Roberts, Jenny R

2014-01-01

Epidemiology has indicated a possible increase in lung cancer among stainless steel welders. Chromium (Cr) is a primary component of stainless steel welding fume. There is an initiative to develop alternative welding consumables [nickel (Ni)- and copper (Cu)-based alloys] that do not contain Cr. No study has been performed to evaluate the toxicity of fumes generated from Ni- and Cu-based consumables. Dose–response and time-course effects on lung toxicity of a Ni- and Cu-based welding fume (Ni–Cu WF) were examined using an in vivo and in vitro bioassay, and compared with two other well-characterized welding fumes. Even though only trace amounts of Cr were present, a persistent increase in lung injury and inflammation was observed for the Ni–Cu WF compared to the other fumes. The difference in response appears to be due to a direct cytotoxic effect by the Ni–Cu WF sample on lung macrophages as opposed to an elevated production of reactive oxygen species (ROS). PMID:25392698

Refreshing the Aged Latent Fingerprints with Ionizing Radiation Prior to the Cyanoacrylate Fuming Procedure: A Preliminary Study.

Science.gov (United States)

Ristova, Mimoza M; Radiceska, Pavlina; Bozinov, Igorco; Barandovski, Lambe

2016-05-01

One of the crucial factors determining the cyanoacrylate deposit quality over latent fingerprints appeared to be the extent of the humidity. This work focuses on the enhancement/refreshment of age-degraded latent fingerprints by irradiating the samples with UV, X-ray, or thermal neutrons prior to the cyanoacrylate (CA) fuming. Age degradation of latent fingerprints deposited on glass surfaces was examined through the decrease in the number of characteristic minutiae counts over time. A term "critical day" was introduced for the time at which the average number of identifiable minutiae definitions drops to one-half. Fingerprints older than their "critical day" were exposed to either UV, X-ray, or thermal neutrons. Identical reference samples were kept unexposed. All samples, both reference and irradiated, were developed during a single CA fuming procedure. Comparative latent fingerprint analysis showed that exposure to ionizing radiation enhances the CA fuming, yielding a 20-30% increase in average minutiae count. © 2015 American Academy of Forensic Sciences.

Utilizing waste materials to enhance mechanical and durability characteristics of concrete incorporated with silica fume

Directory of Open Access Journals (Sweden)

Hamza Ali

2017-01-01

Full Text Available Construction and demolition wastes are increasing significantly due to augmented boom of modern construction. Although the partial cement replacement materials do promote the idea of sustainable construction, the use of construction and demolition waste can also be considered to be viable option to advance the sustainability in modern construction practices. This paper investigates the use of industrial waste materials namely marble dust and crushed bricks as replacement of natural fine aggregates along with the use of silica fume as a partial cement replacement on the mechanical properties and durability characteristics of concrete. Partial replacement levels of waste materials were 10 and 20 percent by volume while the partial replacement level of silica fume was kept to 20 percent at all concrete samples. The results reported in this paper show that the use of marble dust as a replacement material to the natural fine aggregates resulted in an increase in the mechanical properties of concrete. However, the use of crushed bricks did not substantially contribute in the development of strength. Water permeability of concrete incorporated with both silica fume and waste materials (marble dust and crushed bricks decreased significantly. The decrease in water permeability of concrete was attributed to the pozzolanic reaction of silica fume with calcium hydroxide of cement and the filler effect of the waste materials of marble dust and crushed bricks. The use of waste materials also enhance the freeze and thaw resistance of concrete. Authors strongly suggest that the pozzolanic reaction and the development of the microstructure of the concrete through the use of waste materials are largely responsible from the advances in the durability of concrete.

Comparison of Powder Dusting and Cyanoacrylate Fuming Techniques in Retrieving Latent Fingerprint Exposed to Environment Conditions

International Nuclear Information System (INIS)

Mayalvanan, Y.; Sri Pawita Albakri Amir Hamzah; Chuan, L.L.; Muhamad Hilmi Baba; Amidon Anan

2014-01-01

Latent fingerprints are one of the best evidence to prove the presence of an individuals presence at the crime scene. There are many techniques available for a successful fingerprint lifting. Two of the most common ones are fingerprint powder dusting and cyanoacrylate fuming. This research aims to compare both techniques and determine which has a higher success rate in retrieving fingerprints exposed to local environmental conditions for three days. Fingerprint samples were collected from 18 subjects on glass, perspex and aluminium slides. These samples were then exposed to local environmental conditions for three days. The fingerprints were then developed using the aforementioned techniques. Based on the results, it can be safely said that, fuming results in clearer fingerprints and more minutiae can be found from the retrieved fingerprints even with exposure to less than optimum local conditions. This proves that fuming is a better fingerprint lifting method to resolve latent fingerprint compared to powder dusting. Surface on which the fingerprint is retrieved from influences the quality of clarity of a latent fingerprint. (author)

Corrosion resistance of nickel alloys with chromium and silicon to the red fuming nitric acid

International Nuclear Information System (INIS)

Gurvich, L.Ya.; Zhirnov, A.D.

1994-01-01

Corrosion and electrochemical behaviour of binary Ni-Cr, Ni-Si nickel and ternary Ni-Cr-Si alloys in the red fuming nitric acid (RFNA) (8-% of HNO 3 +20% of N 2 O 4 ) is studied. It is shown that nickel alloying with chromium improves its corrosion resistance to the red fuming nitric acid. Nickel alloying with silicon in quantities of up to 5 % reduces, and up to 10%-increases abruptly the corrosion resistance with subsequent decrease of the latter after the further increase of concentration. Ni-15% of Cr alloy alloying with silicon increases monotonously the corrosion resistance. 10 refs., 7 figs., 3 tabs

Compresive Strength for FRC Member using Silica Fume

OpenAIRE

R.M.Damgir,; Y.M.Ghugal

2011-01-01

The compressive strength of concrete was obtained by conducting tests on standard cubes of size 150X 150X150 mm size with fibers 0 to 5% with an increment of 0.5% and Silica Fume of 5%.The compressivestrength was determined by carrying out compressive test by using UTM. Slump loss increases with increase in Fiber Volume Crack Width reduces as percentage Fiber Volume increases and Crack width varying between 0.75 to 1.30 mm for 28 days concrete strength. Toughness of concrete member increases ...

Cycling of lithium/metal oxide cells using composite electrolytes containing fumed silicas

International Nuclear Information System (INIS)

Zhou Jian; Fedkiw, Peter S.

2003-01-01

The effect on cycle capacity is reported of cathode material (metal oxide, carbon, and current collector) in lithium/metal oxide cells cycled with fumed silica-based composite electrolytes. Three types of electrolytes are compared: filler-free electrolyte consisting of methyl-terminated poly(ethylene glycol) oligomer (PEGdm, M w =250)+lithium bis(trifluromethylsufonyl)imide (LiTFSI) (Li:O=1:20), and two composite systems of the above baseline liquid electrolyte containing 10-wt% A200 (hydrophilic fumed silica) or R805 (hydrophobic fumed silica with octyl surface group). The composite electrolytes are solid-like gels. Three cathode active materials (LiCoO 2 , V 6 O 13 , and Li x MnO 2 ), four conducting carbons (graphite Timrex [reg] SFG 15, SFG 44, carbon black Vulcan XC72R, and Ketjenblack EC-600JD), and three current collector materials (Al, Ni, and carbon fiber) were studied. Cells with composite electrolytes show higher capacity, reduced capacity fade, and less cell polarization than those with filler-free electrolyte. Among the three active materials studied, V 6 O 13 cathodes deliver the highest capacity and Li x MnO 2 cathodes render the best capacity retention. Discharge capacity of Li/LiCoO 2 cells is affected greatly by cathode carbon type, and the capacity decreases in the order of Ketjenblack>SFG 15>SFG 44>Vulcan. Current collector material also plays a significant role in cell cycling performance. Lithium/vanadium oxide (V 6 O 13 ) cells deliver increased capacity using Ni foil and carbon fiber current collectors in comparison to an Al foil current collector

Feasibility of mobile health game "Fume" in supporting tobacco-related health literacy among early adolescents: A three-armed cluster randomized design.

Science.gov (United States)

Parisod, Heidi; Pakarinen, Anni; Axelin, Anna; Löyttyniemi, Eliisa; Smed, Jouni; Salanterä, Sanna

2018-05-01

New interventions supporting health literacy and a tobacco-free lifestyle in adolescence are needed to narrow the widening gap in existing health inequalities. Health games offer potential and could be utilized for example in school healthcare, but more research is needed to increase the understanding of the effects of game elements in health interventions. The aim of this feasibility study is to determine the short-term effectiveness of the tobacco-related mobile health game Fume and a non-gamified website in comparison with a no-intervention control group, regarding tobacco-related health literacy among 10-13-year-old early adolescents. In addition, we compare the demand for and acceptability of Fume to that of the website. In total, 151 early adolescents participated in this single-blinded, three-armed cluster randomized trial. The participants from three municipalities in southwest Finland were randomly allocated between a group with access to the health game Fume (n = 61), a group with access to the website (n = 47), and a group with no intervention (n = 43). The intervention groups first participated in a 20-min training session with Fume/the website, and then had two weeks to use Fume/the website based on their own interest. Short-term effectiveness was measured by primary (anti-smoking self-efficacy) and secondary (smoking outcome expectations, attitudes towards tobacco use, tobacco-use motives, motivation to decline tobacco use in the future, and knowledge about tobacco) outcomes derived from the theory-based determinants of tobacco-related health literacy and evaluated with self-assessment questionnaires at baseline and post-intervention (after a two-week follow-up). For evaluating the demand, the actual use of Fume/the website was tracked during the two-week period. Regarding acceptability, the raised interest towards Fume/the website and opinions about the interventions were evaluated post-intervention. Differences were tested with the Mc

A model for prediction of fume formation rate in gas metal arc welding (GMAW), globular and spray modes, DC electrode positive.

Science.gov (United States)

Dennis, J H; Hewitt, P J; Redding, C A; Workman, A D

2001-03-01

Prediction of fume formation rate during metal arc welding and the composition of the fume are of interest to occupational hygienists concerned with risk assessment and to manufacturers of welding consumables. A model for GMAW (DC electrode positive) is described based on the welder determined process parameters (current, wire feed rate and wire composition), on the surface area of molten metal in the arc and on the partial vapour pressures of the component metals of the alloy wire. The model is applicable to globular and spray welding transfer modes but not to dip mode. Metal evaporation from a droplet is evaluated for short time increments and total evaporation obtained by summation over the life of the droplet. The contribution of fume derived from the weld pool and spatter (particles of metal ejected from the arc) is discussed, as are limitations of the model. Calculated droplet temperatures are similar to values determined by other workers. A degree of relationship between predicted and measured fume formation rates is demonstrated but the model does not at this stage provide a reliable predictive tool.

Computational Fluid Dynamic Modeling of Zinc Slag Fuming Process in Top-Submerged Lance Smelting Furnace

Science.gov (United States)

Huda, Nazmul; Naser, Jamal; Brooks, Geoffrey; Reuter, Markus A.; Matusewicz, Robert W.

2012-02-01

Slag fuming is a reductive treatment process for molten zinciferous slags for extracting zinc in the form of metal vapor by injecting or adding a reductant source such as pulverized coal or lump coal and natural gas. A computational fluid dynamic (CFD) model was developed to study the zinc slag fuming process from imperial smelting furnace (ISF) slag in a top-submerged lance furnace and to investigate the details of fluid flow, reaction kinetics, and heat transfer in the furnace. The model integrates combustion phenomena and chemical reactions with the heat, mass, and momentum interfacial interaction between the phases present in the system. A commercial CFD package AVL Fire 2009.2 (AVL, Graz, Austria) coupled with a number of user-defined subroutines in FORTRAN programming language were used to develop the model. The model is based on three-dimensional (3-D) Eulerian multiphase flow approach, and it predicts the velocity and temperature field of the molten slag bath, generated turbulence, and vortex and plume shape at the lance tip. The model also predicts the mass fractions of slag and gaseous components inside the furnace. The model predicted that the percent of ZnO in the slag bath decreases linearly with time and is consistent broadly with the experimental data. The zinc fuming rate from the slag bath predicted by the model was validated through macrostep validation process against the experimental study of Waladan et al. The model results predicted that the rate of ZnO reduction is controlled by the mass transfer of ZnO from the bulk slag to slag-gas interface and rate of gas-carbon reaction for the specified simulation time studied. Although the model is based on zinc slag fuming, the basic approach could be expanded or applied for the CFD analysis of analogous systems.

Fuels planning: science synthesis and integration; environmental consequences fact sheet 12: Water Erosion Prediction Project (WEPP) Fuel Management (FuMe) tool

Science.gov (United States)

William Elliot; David Hall

2005-01-01

The Water Erosion Prediction Project (WEPP) Fuel Management (FuMe) tool was developed to estimate sediment generated by fuel management activities. WEPP FuMe estimates sediment generated for 12 fuel-related conditions from a single input. This fact sheet identifies the intended users and uses, required inputs, what the model does, and tells the user how to obtain the...

Triglycerides, total cholesterol, high density lipoprotein cholesterol and low density lipoprotein cholesterol in rats exposed to premium motor spirit fumes.

Science.gov (United States)

Aberare, Ogbevire L; Okuonghae, Patrick; Mukoro, Nathaniel; Dirisu, John O; Osazuwa, Favour; Odigie, Elvis; Omoregie, Richard

2011-06-01

Deliberate and regular exposure to premium motor spirit fumes is common and could be a risk factor for liver disease in those who are occupationally exposed. A possible association between premium motor spirit fumes and plasma levels of triglyceride, total cholesterol, high density lipoprotein cholesterol and low density lipoprotein cholesterol using a rodent model could provide new insights in the pathology of diseases where cellular dysfunction is an established risk factor. The aim of this study was to evaluate the possible effect of premium motor spirit fumes on lipids and lipoproteins in workers occupationally exposed to premium motor spirit fumes using rodent model. Twenty-five Wister albino rats (of both sexes) were used for this study between the 4(th) of August and 7(th) of September, 2010. The rats were divided into five groups of five rats each. Group 1 rats were not exposed to premium motor spirit fumes (control group), group 2 rats were exposed for 1 hour daily, group 3 for 3 hours daily, group 4 for 5 hours daily and group 5 for 7 hours daily. The experiment lasted for a period of 4 weeks. Blood samples obtained from all the groups after 4 weeks of exposure were used for the estimation of plasma levels of triglyceride, total cholesterol, high density lipoprotein- cholesterol and low density lipoprotein- cholesterol. Results showed significant increase in means of plasma total cholesterol and low density lipoprotein levels (P<0.05). The mean triglyceride and total body weight were significantly lower (P<0.05) in the exposed group when compared with the unexposed. The plasma level of high density lipoprotein, the ratio of low density lipoprotein to high density lipoprotein and the ratio of total cholesterol to high density lipoprotein did not differ significantly in exposed subjects when compared with the control group. These results showed that frequent exposure to petrol fumes may be highly deleterious to the liver cells.

Minimum acceptable face velocities of laboratory fume hoods and guidelines for their classification

International Nuclear Information System (INIS)

Bolton, N.E.; Porter, W.E.; Alcorn, S.P.; Everett, W.S.; Hunt, J.B.; Morehead, J.F.; Higdon, H.F.

1978-06-01

Data developed to support the requirement of a 100 LFM minimum face velocity requirement for laboratory fume hoods are summarized. Also included is a description of the Y-12 test hood as well as guidelines for a hood classification scheme

[Study on the chemical components of edible oil fume in kitchen and its genotoxity on Drosophila].

Science.gov (United States)

Li, S; Wang, Y; Zhang, J; Zhao, X

1999-01-30

To study the chemical components of the condensate of edible oil fume in kitchen and its genotoxicity on Drosophila. Analysis for the chemical components was carried out by gas chromatography and mass spectra (GC/MS) and its genotoxicity was studied by sex linked recessive lethal (SLRL) test in Drosophila. A total of 74 organic compounds were found in samples of condensed oil from the fume in kitchen. It included hydroxylic acids, hydrocarbons, alcohols, esters, aldehydes, ketones, aromatic compounds, and steroids, etc. The total mutagenicity rates in SLRL test induced by the samples at concentrations of 110,320 and 960 mg/L were 0.1732%, 0.4306% and 0.1707% respectively. The sterility rates of the first broods were 2.564%, 2.056% and 2.845% at above 3 concentrations respectively(P < 0.05, as compared with the control). The mutagenicity rate of the second brood at 320 mg/L was 0.530% and that of the third brood at 110 mg/L 0.540%(P < 0.001). Some of the compounds in the condensate of edible oil fume were proved to have high recessive lethal effect and genotoxic effect on the reproductive system of Drosophila.

Effects of superglue fuming on materials characterization of zip-lock polyethylene bags for route forensic analyses

International Nuclear Information System (INIS)

Koester, C.J.; Grant, P.M.; Blankenship, J.F.

2013-01-01

Using cyanoacrylate or 'superglue' fuming to develop latent dermatoglyphic prints significantly altered the volatile and semivolatile compounds within the material of polyethylene zip-lock bags. Comparisons of SPME-GC/MS analyses of poly bags obtained before and after application of a glue fuming fingermark-developing technique resulted in markedly different material profiles of the bags. Not only were species added to the chemical composition of a bag, but other compounds that had been initially present were removed. These effects are particularly important for nuclear forensic investigations in the realm of route (pathway) analyses, and may also be of general interest to criminalistics laboratories that examine illicit drugs and their packaging. (author)

The effects of silica fume and hydrated lime on the strength development and durability characteristics of concrete under hot water curing condition

Directory of Open Access Journals (Sweden)

Hamza Ali

2017-01-01

Full Text Available Sustainability is considered to be highly important for preserving continued industrial growth and human development. Concrete, being the world’s largest manufacturing material comprises cement as an essential binding component for strength development. However, excessive production of cement due to high degree of construction practices around the world frames cement as a leading pollutant of releasing significant amounts of CO2 in the atmosphere. To overcome this environmental degradation, silica fume and hydrated lime are used as partial replacements to cement. This paper begins with the examination of the partial replacement levels of hydrated lime and silica fume in concrete and their influence on the mechanical properties and durability characteristics of concrete. The effect of hot water curing on concrete incorporated with both silica fume and hydrated lime is also investigated in this paper. The results reported in this paper show that the use of silica fume as a partial replacement material improved both the mechanical properties and durability characteristics of concrete due to the formation of calcium silica hydrate crystals through the pozzolanic reaction. Although the hydrated lime did not significantly contribute in the development of strength, its presence enhanced the durability of concrete especially at long-term. The results also showed that hot water curing enhanced the strength development of concrete incorporated with silica fume due to the accelerated rate of both the hydration and pozzolanic reaction that takes place between silica fume and calcium hydroxide of the cement matrix particularly at early times. The results reported in this paper have significant contribution in the development of sustainable concrete. The paper does not only address the use of alternative binders as a partial replacement material in concrete but also suggest proper curing conditions for the proposed replacement materials. These practices

Upgrading offshore pipelines concrete coated by silica fume additive against aggressive mechanical laying

Directory of Open Access Journals (Sweden)

M.I. Abdou

2016-06-01

Full Text Available Studies have been carried out to investigate the possibility of utilizing a broad range of micro-silica partial additions with cement in the production of concrete coating. This study investigated the strength properties and permeability of micro-silica concrete to achieve resistance toward concrete cracking and damage during laying. The chemical composition of micro-silica (silica fume was determined, and has been conducted on concrete mixes with additions of 3 up to 25% by weight of cement in concrete. Properties of hardened concrete such as compressive strength, flexural strength, and permeability have been assessed and analyzed. Cubic specimens and beams were produced and cured in a curing tank for 7 and 28 days. Testing results have shown that additions of silica fume to cement between 5% and 7%, which acts as a filler and cementations material, developed high flexural and compressive strength with reduction of permeability.

Altered ion transport in normal human bronchial epithelial cells following exposure to chemically distinct metal welding fume particles.

Science.gov (United States)

Fedan, Jeffrey S; Thompson, Janet A; Meighan, Terence G; Zeidler-Erdely, Patti C; Antonini, James M

2017-07-01

Welding fume inhalation causes pulmonary toxicity, including susceptibility to infection. We hypothesized that airway epithelial ion transport is a target of fume toxicity, and investigated the effects of fume particulates from manual metal arc-stainless steel (MMA-SS) and gas metal arc-mild steel (GMA-MS) on ion transport in normal human bronchial epithelium (NHBE) cultured in air-interface. MMA-SS particles, more soluble than GMA-MS particles, contain Cr, Ni, Fe and Mn; GMA-MS particles contain Fe and Mn. MMA-SS or GMA-MS particles (0.0167-166.7μg/cm 2 ) were applied apically to NHBEs. After 18h transepithelial potential difference (V t ), resistance (R t ), and short circuit current (I sc ) were measured. Particle effects on Na + and Cl¯ channels and the Na + ,K + ,2Cl¯-cotransporter were evaluated using amiloride (apical), 5-nitro-2-[(3-phenylpropyl)amino]benzoic acid (NPPB, apical), and bumetanide (basolateral), respectively. MMA-SS (0.0167-16.7μg/cm 2 ) increased basal V t . Only 16.7μg/cm 2 GMA-MS increased basal V t significantly. MMA-SS or GMA-MS exposure potentiated I sc responses (decreases) to amiloride and bumetanide, while not affecting those to NPPB, GMA-MS to a lesser degree than MMA-SS. Variable effects on R t were observed in response to amiloride, and bumetanide. Generally, MMA-SS was more potent in altering responses to amiloride and bumetanide than GMA-MS. Hyperpolarization occurred in the absence of LDH release, but decreases in V t , R t , and I sc at higher fume particulate doses accompanied LDH release, to a greater extent for MMA-SS. Thus, Na + transport and Na + ,K + ,2Cl¯-cotransport are affected by fume exposure; MMA-MS is more potent than GMA-MS. Enhanced Na + absorption and decreased airway surface liquid could compromise defenses against infection. Published by Elsevier Inc.

Effects of curing type, silica fume fineness, and fiber length on the mechanical properties and impact resistance of UHPFRC

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Hasan Şahan Arel

Full Text Available The effects of silica fume fineness and fiber aspect ratio on the compressive strength and impact resistance of ultra high-performance fiber-reinforced concrete (UHPFRC are investigated experimentally. To this end, UHPFRC mixtures are manufactured by combining silica fumes with different fineness (specific surface areas: 17,200, 20,000, and 27,600 m2/kg and hooked-end steel fibers with various aspect ratios (lengths: 8, 13, and 16 mm. The samples are subjected to standard curing, steam curing, and hot-water curing. Compressive strength tests are conducted after 7-, 28-, 56-, and 90-day curing periods, and an impact resistance experiment is performed after the 90th day. A steam-cured mixture of silica fumes with a specific surface area of 27,600 m2/kg and 16-mm-long fibers produce better results than the other mixtures in terms of mechanical properties. Moreover, impact resistance increases with the fiber aspect ratio. Keywords: Curing, Fineness, UHPFRC, Mechanical properties, Fiber

Some engineering properties of heavy concrete added silica fume

International Nuclear Information System (INIS)

Akkaş, Ayşe; Başyiğit, Celalettin; Esen, Serap

2013-01-01

Many different types of building materials have been used in building construction for years. Heavy concretes can be used as a building material for critical building as it can contain a mixture of many heavy elements. The barite itself for radiation shielding can be used and also in concrete to produce the workable concrete with a maximum density and adequate structural strength. In this study, some engineering properties like compressive strength, elasticity modules and flexure strength of heavy concretes’ added Silica fume have been investigated

Smog chamber study on the evolution of fume from residential coal combustion.

Science.gov (United States)

Geng, Chunmei; Wang, Kun; Wang, Wei; Chen, Jianhua; Liu, Xiaoyu; Liu, Hongjie

2012-01-01

Domestic coal stoves are widely used in countryside and greenbelt residents in China for heating and cooking, and emit considerable pollutants to the atmosphere because of no treatment of their exhaust, which can result in deteriorating local air quality. In this study, a dynamic smog chamber was used to investigate the real-time emissions of gaseous and particulate pollutants during the combustion process and a static smog chamber was used to investigate the fume evolution under simulate light irradiation. The real-time emissions revealed that the total hydrocarbon (THC) and CO increased sharply after ignition, and then quickly decreased, indicating volatilization of hydrocarbons with low molecular weight and incomplete combustion at the beginning stage of combustion made great contribution to these pollutants. There was evident shoulder peak around 10 min combustion for both THC and CO, revealing the emissions from vitrinite combustion. Additionally, another broad emission peak of CO after 30 min was also observed, which was ascribed to the incomplete combustion of the inertinite. Compared with THC and CO, there was only one emission peak for NOx, SO2 and particular matters at the beginning stage of combustion. The fume evolution with static chamber simulation indicated that evident consumption of SO2 and NOx as well as new particle formation were observed. The consumption rates for SO2 and NOx were about 3.44% hr(-1) and 3.68% hr(-1), the new particle formation of nuclei particles grew at a rate of 16.03 nm/hr during the first reaction hour, and the increase of the diameter of accumulation mode particles was evident. The addition of isoprene to the diluted mixture of the fume could promote 03 and secondary particle formation.

Occupational exposure to solvents, metals and welding fumes and risk of Parkinson's disease

NARCIS (Netherlands)

van der Mark, Marianne; Vermeulen, Roel; Nijssen, Peter C G; Mulleners, Wim M; Sas, Antonetta M G; van Laar, Teus; Huss, Anke; Kromhout, Hans

OBJECTIVES: The aim of this study was to investigate the potential association between occupational exposure to solvents, metals and/or welding fumes and risk of developing Parkinson's disease (PD). METHODS: Data of a hospital based case-control study including 444 PD patients and 876 age and sex

Parental Occupational Exposure to Heavy Metals and Welding Fumes and Risk of Testicular Germ Cell Tumors in Offspring

DEFF Research Database (Denmark)

Togawa, Kayo; Le Cornet, Charlotte; Feychting, Maria

2016-01-01

BACKGROUND: Data are scarce on the association between prenatal/preconception environmental exposure and testicular germ cell tumor (TGCT) in offspring. We examined parental occupational exposures to heavy metals and welding fumes in relation to TGCT in offspring in a registry-based case-control ......BACKGROUND: Data are scarce on the association between prenatal/preconception environmental exposure and testicular germ cell tumor (TGCT) in offspring. We examined parental occupational exposures to heavy metals and welding fumes in relation to TGCT in offspring in a registry-based case......-control study (NORD-TEST Study). METHODS: We identified TGCT cases diagnosed at ages 14-49 years in Finland (1988-2012), Norway (1978-2010), and Sweden (1979-2011) through nationwide cancer registries. These cases were individually matched by country and year of birth to controls selected from population...... registries. Information on parental occupations was retrieved from censuses. From this, we estimated prenatal/preconception exposures of chromium, iron, nickel, lead, and welding fumes (all three countries), and cadmium (Finland only) for each parent using job-exposure matrices specifying prevalence (P...

Risk communication concerning welding fumes for the primary preventive care of welding apprentices in southern Brazil.

Science.gov (United States)

Cezar-Vaz, Marta Regina; Bonow, Clarice Alves; Vaz, Joana Cezar

2015-01-19

This study's aim was to assess the perceptions of welding apprentices concerning welding fumes being associated with respiratory and cardiovascular disorders and assess the implementation of risk communication as a primary prevention tool in the welding training process. This quasi-experimental, non-randomized study with before-and-after design was conducted with 84 welding apprentices in Southern Brazil. Poisson Regression analysis was used. Relative Risk was the measure used with a 95% confidence interval and 5% (p ≤ 0.05) significance level. Significant association was found between perceptions of worsened symptoms of respiratory disorders caused by welding fumes and educational level (p = 0.049), the use of goggles to protect against ultraviolet rays (p = 0.023), and access to services in private health facilities without insurance coverage (p = 0.001). Apprentices younger than 25 years old were 4.9 times more likely to perceive worsened cardiovascular symptoms caused by welding fumes after risk communication (RR = 4.91; CI 95%: 1.09 to 22.2). The conclusion is that risk communication as a primary preventive measure in continuing education processes implemented among apprentices, who are future welders, was efficacious. Thus, this study confirms that risk communication can be implemented as a primary prevention tool in welding apprenticeships.

Assessment of the Biological Effects of Welding Fumes Emitted From Metal Active Gas and Manual Metal Arc Welding in Humans.

Science.gov (United States)

Dewald, Eva; Gube, Monika; Baumann, Ralf; Bertram, Jens; Kossack, Veronika; Lenz, Klaus; Reisgen, Uwe; Kraus, Thomas; Brand, Peter

2015-08-01

Emissions from a particular welding process, metal inert gas brazing of zinc-coated steel, induce an increase in C-reactive protein. In this study, it was investigated whether inflammatory effects could also be observed for other welding procedures. Twelve male subjects were separately exposed to (1) manual metal arc welding fumes, (2) filtered air, and (3) metal active gas welding fumes for 6 hours. Inflammatory markers were measured in serum before, and directly, 1 and 7 days after exposure. Although C-reactive protein concentrations remained unchanged, neutrophil concentrations increased directly after exposure to manual metal arc welding fumes, and endothelin-1 concentrations increased directly and 24 hours after exposure. After exposure to metal active gas and filtered air, endothelin-1 concentrations decreased. The increase in the concentrations of neutrophils and endothelin-1 may characterize a subclinical inflammatory reaction, whereas the decrease of endothelin-1 may indicate stress reduction.

Exposure of welders to fumes, Cr, Ni, Cu and gases in Dutch industries

NARCIS (Netherlands)

Wal, J.F. van der

1985-01-01

The exposure of welders in Dutch industries to total particulate, chromium, nickel and copper fume during the welding of unalloyed, stainless and high alloyed steels has been investigated. The exposure to the gases NO2, NO and ozone is also discussed. The results are presented in tables and graphs.

Fumed Silica Nanoparticles Incorporated in Quaternized Poly(Vinyl Alcohol Nanocomposite Membrane for Enhanced Power Densities in Direct Alcohol Alkaline Fuel Cells

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Selvaraj Rajesh Kumar

2015-12-01

Full Text Available A nanocomposite polymer membrane based on quaternized poly(vinyl alcohol/fumed silica (QPVA/FS was prepared via a quaternization process and solution casting method. The physico-chemical properties of the QPVA/FS membrane were investigated. Its high ionic conductivity was found to depend greatly on the concentration of fumed silica in the QPVA matrix. A maximum conductivity of 3.50 × 10−2 S/cm was obtained for QPVA/5%FS at 60 °C when it was doped with 6 M KOH. The permeabilities of methanol and ethanol were reduced with increasing fumed silica content. Cell voltage and peak power density were analyzed as functions of fumed silica concentration, temperature, methanol and ethanol concentrations. A maximum power density of 96.8 mW/cm2 was achieved with QPVA/5%FS electrolyte using 2 M methanol + 6 M KOH as fuel at 80 °C. A peak power density of 79 mW/cm2 was obtained using the QPVA/5%FS electrolyte with 3 M ethanol + 5 M KOH as fuel. The resulting peak power densities are higher than the majority of published reports. The results confirm that QPVA/FS exhibits promise as a future polymeric electrolyte for use in direct alkaline alcoholic fuel cells.

The use of high expansion foam in the control of sodium and other fumes

International Nuclear Information System (INIS)

Hughes, G.W.

1971-01-01

The uses of high expansion air foam for removing sodium fume and airborne radioactivity is discussed. Experiments are described which indicate that a high rate of removal of air contamination can be expected by encapsulation in a high expansion foam of low stability. (author)

Non-occupational exposure to paint fumes during pregnancy and fetal growth in a general population

DEFF Research Database (Denmark)

Sørensen, Mette; Andersen, Anne-Marie N; Raaschou-Nielsen, Ole

2010-01-01

in their residence during pregnancy. The mothers were also asked about smoking habits and alcohol consumption during pregnancy, pre-pregnancy weight, height, parity and occupation. Information on birth weight and gestational age was obtained from national registers. We found that 45% of the mothers had been exposed......Occupational exposure to organic solvents during pregnancy has been associated with reduced fetal growth. Though organic solvents in the form of paint fumes are also found in the home environment, no studies have investigated the effect of such exposure in a general population. We studied...... associations between residential exposure to paint fumes during pregnancy and fetal growth within the Danish National Birth Cohort which consecutively recruited pregnant women from 1996 to 2002 from all over Denmark. Around the 30th pregnancy week, 19,000 mothers were interviewed about use of paint...

Development of UHPC mixtures utilizing natural and industrial waste materials as partial replacements of silica fume and sand.

Science.gov (United States)

Ahmad, Shamsad; Hakeem, Ibrahim; Maslehuddin, Mohammed

2014-01-01

In the exploratory study presented in this paper, an attempt was made to develop different mixtures of ultrahigh performance concrete (UHPC) using various locally available natural and industrial waste materials as partial replacements of silica fume and sand. Materials such as natural pozzolana (NP), fly ash (FA), limestone powder (LSP), cement kiln dust (CKD), and pulverized steel slag (PSS), all of which are abundantly available in Saudi Arabia at little or no cost, were employed in the development of the UHPC mixtures. A base mixture of UHPC without replacement of silica fume or sand was selected and a total of 24 trial mixtures of UHPC were prepared using different percentages of NP, FA, LSP, CKD, and PSS, partially replacing the silica fume and sand. Flow and 28-d compressive strength of each UHPC mixture were determined to finally select those mixtures, which satisfied the minimum flow and strength criteria of UHPC. The test results showed that the utilization of NP, FA, LSP, CKD, and PSS in production of UHPC is possible with acceptable flow and strength. A total of 10 UHPC mixtures were identified with flow and strength equal to or more than the minimum required.

Exposure to welding fumes is associated with hypomethylation of the F2RL3 gene: a cardiovascular disease marker.

Science.gov (United States)

Hossain, Mohammad B; Li, Huiqi; Hedmer, Maria; Tinnerberg, Håkan; Albin, Maria; Broberg, Karin

2015-12-01

Welders are at risk for cardiovascular disease. Recent studies linked tobacco smoke exposure to hypomethylation of the F2RL3 (coagulation factor II (thrombin) receptor-like 3) gene, a marker for cardiovascular disease prognosis and mortality. However, whether welding fumes cause hypomethylation of F2RL3 remains unknown. We investigated 101 welders (median span of working as a welder: 7 years) and 127 unexposed controls (non-welders with no obvious exposure to respirable dust at work), age range 23-60 years, all currently non-smoking, in Sweden. The participants were interviewed about their work history, lifestyle factors and diseases. Personal sampling of respirable dust was performed for the welders. DNA methylation of F2RL3 in blood was assessed by pyrosequencing of four CpG sites, CpG_2 (corresponds to cg03636183) to CpG_5, in F2RL3. Multivariable linear regression analysis was used to assess the association between exposure to welding fumes and F2RL3 methylation. Welders had 2.6% lower methylation of CpG_5 than controls (pWelding fumes exposure and previous smoking were associated with F2RL3 hypomethylation. This finding links low-to-moderate exposure to welding fumes to adverse effects on the cardiovascular system, and suggests a potential mechanistic pathway for this link, via epigenetic effects on F2RL3 expression. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Chloride accelerated test: influence of silica fume, water/binder ratio and concrete cover thickness

Directory of Open Access Journals (Sweden)

E. Pereira

Full Text Available In developed countries like the UK, France, Italy and Germany, it is estimated that spending on maintenance and repair is practically the same as investment in new constructions. Therefore, this paper aims to study different ways of interfering in the corrosion kinetic using an accelerated corrosion test - CAIM, that simulates the chloride attack. The three variables are: concrete cover thickness, use of silica fume and the water/binder ratio. It was found, by analysis of variance of the weight loss of the steel bars and chloride content in the concrete cover thickness, there is significant influence of the three variables. Also, the results indicate that the addition of silica fume is the path to improve the corrosion protection of low water/binder ratio concretes (like 0.4 and elevation of the concrete cover thickness is the most effective solution to increase protection of high water/binder ratio concrete (above 0.5.

Determination of Informal Sector as Urban Pollution Source : Fume Characterization of Small-scale Manual Metal Arc Welding using Factor Analysis in Bandung City

Directory of Open Access Journals (Sweden)

A. Nastiti

2012-04-01

Full Text Available In developing countries, the informal sector, particularly small-scale welding activities, are considered to be an important contributor to urban air pollution although studies in this sector are limited. This study aims to identify the composition of small-scale welding fume in order to further investigate the effects and set control strategies and urban pollution abatement policies. Breathing zone air samples were collected from 30 mild steel manual metal arc welders and 17 non-welders in Bandung City, West Java, Indonesia. The respirable particulates in air samples were analyzed using gravimetric method, and Instrumental Neutron Activation Analysis (INAA was employed to identify characteristic of welding fume. It was found that respirable particulates concentration in welders (range : 315.6 and 3,735.93 µgm-3; average 1,545.436 µgm-3 were significantly higher than in non-welders (range : 41.84 and 1,688.03 µgm-3; average : 375.783 µgm-3. Welders’ breathing zones contain Fe>Na>K>Mn>Al >Cr>Ti>Cl>Br>I>Zn>Sb>V>Co>Sc; while non-welders’ breathing zones contain Cr>F>Al>Ti>Na>Br>I>Mn>Cl>Co>Zn>Sc. Inter-species correlation analysis conducted using Statgraphic Ver. 4.0 shows that Fe (range : n.d. – 775.19 µgm-3; average: 0.1674 µgm-3, Co (range : n.d. – 0.51 µgm-3; average: 0.000082 µgm-3, Mn (range : 0.39 – 148.37 µgm-3; average: 0.0374 µgm-3, Na (range: 0.17 and 623.85 µgm-3; average: 0.0973 µgm-3 and K (range : n.d. – 301.15 µgm-3; average: 0.0535 µgm-3 were emitted from welding activity, and thus are considered as components of welding fume which contribute to urban air pollution. Although welding fume and the identified species in welding fume were still below permissible limit, small-scale welding activities have great potential in emitting higher fume concentration due to due to high variability of welding activities, such as welding frequency, materials being welded, and varied environmental conditions

Determination of Informal Sector as Urban Pollution Source : Fume Characterization of Small-scale Manual Metal Arc Welding using Factor Analysis in Bandung City

International Nuclear Information System (INIS)

Nastiti, A.; Pramudyastuti, D.Y.; Oginawati, K.; Santoso, M.

2012-01-01

In developing countries, the informal sector, particularly small-scale welding activities, are considered to be an important contributor to urban air pollution although studies in this sector are limited. This study aims to identify the composition of small-scale welding fume in order to further investigate the effects and set control strategies and urban pollution abatement policies. Breathing zone air samples were collected from 30 mild steel manual metal arc welders and 17 non-welders in Bandung City, West Java, Indonesia. The respirable particulates in air samples were analyzed using gravimetric method, and Instrumental Neutron Activation Analysis (INAA) was employed to identify characteristic of welding fume. It was found that respirable particulates concentration in welders (range : 315.6 and 3,735.93 µgm -3 ; average 1,545.436 µgm -3 ) were significantly higher than in non-welders (range : 41.84 and 1,688.03 µgm -3 ; average : 375.783 µgm -3 ). Welders' breathing zones contain Fe>Na>K>Mn>Al >Cr>Ti>Cl>Br>I>Zn>Sb>V>Co>Sc; while non-welders' breathing zones contain Cr>F>Al>Ti>Na>Br>I>Mn>Cl>Co>Zn>Sc. Inter-species correlation analysis conducted using Statgraphic Ver. 4.0 shows that Fe (range : n.d. - 775.19 µgm -3 ; average: 0.1674µgm -3 ), Co (range : n.d. - 0.51 µgm -3 ; average: 0.000082 µgm -3 ), Mn (range : 0.39 - 148.37 µgm -3 ; average: 0.0374 µgm -3 ), Na (range: 0.17 and 623.85 µgm -3 ; average: 0.0973 µgm -3 ) and K (range : n.d. - 301.15 µgm -3 ; average: 0.0535 µgm -3 ) were emitted from welding activity, and thus are considered as components of welding fume which contribute to urban air pollution. Although welding fume and the identified species in welding fume were still below permissible limit, small-scale welding activities have great potential in emitting higher fume concentration due to due to high variability of welding activities, such as welding frequency, materials being welded, and varied environmental conditions. (author)

Fresh and some mechanical properties of sifcon containing silica fume

Directory of Open Access Journals (Sweden)

Salih Shakir

2018-01-01

Full Text Available Slurry infiltrated fiber concrete (SIFCON is one of the recently developed construction material. SIFCON could be considered as a special type of fiber concrete with high fiber content. The matrix of SIFCON consists of flowing cement mortar or cement slurry. SIFCON has a very good potential for application in area where resistance to impact and high ductility are needed especially in designing the seismic retrofit, in the structures under impact and explosive effects and repair of structural reinforced concrete element. The main objective of this paper is to determine the effect of steel fiber content and silica fume (SF cement replacement on the mechanical properties of SIFCON concrete. The percentage of SF replacement was 10% by weight of cement in SIFCON slurry, and three different volume fractions of hooked ended steel fiber (6, 8.5, and 11 % were used. The tested properties of SIFCON were compressive strength and splitting tensile strength which were carried out on standard size of cubes and cylinders respectively at the age of 7and 28 days. It was observed that the mechanical properties of SIFCON were affected in a positive manner by using silica fume as a partial replacement of cement and by adding steel fiber reinforcement in different percentages. The compressive and splitting tensile strength up to 83.7 MPa and 17.3MPa, respectively were obtained at the age of 28 days.

Improvement in ionic conductivity of self-supported P(MMA-AN-VAc) gel electrolyte by fumed silica for lithium ion batteries

International Nuclear Information System (INIS)

Liao Youhao; Rao Mumin; Li Weishan; Tan Chunlin; Yi Jin; Chen Lang

2009-01-01

Fumed silica was used as a dopant in the preparation of poly(methyl methacrylate-acrylonitrile-vinyl acetate) (P(MMA-AN-VAc)) to improve the ionic conductivity of the P(MMA-AN-VAc)-based gel polymer electrolyte (GPE). The performance of the P(MMA-AN-VAc) membrane and its GPE for lithium ion battery use were studied by XRD, SEM, TGA, LSV, CA, EIS, and charge/discharge test. It is found that the doping of fumed silica in the P(MMA-AN-VAc) changes the membrane from semi-crystal to amorphous state and the pore structure of the membrane. By the doping of 10 wt.% fumed silica in the membrane, the porosity of the membrane increases with the pore dispersed more uniformly and interconnected and having higher electrolyte uptake, resulting in the improvement in ionic conductivity of the GPE from 3.48 x 10 -3 to 5.13 x 10 -3 S cm -1 at ambient temperature. On the other hand, the thermal stability of the membrane, the electrochemical stability of the GPE, and the cyclic performance of the battery are also improved.

Development of UHPC Mixtures Utilizing Natural and Industrial Waste Materials as Partial Replacements of Silica Fume and Sand

Directory of Open Access Journals (Sweden)

Shamsad Ahmad

2014-01-01

Full Text Available In the exploratory study presented in this paper, an attempt was made to develop different mixtures of ultrahigh performance concrete (UHPC using various locally available natural and industrial waste materials as partial replacements of silica fume and sand. Materials such as natural pozzolana (NP, fly ash (FA, limestone powder (LSP, cement kiln dust (CKD, and pulverized steel slag (PSS, all of which are abundantly available in Saudi Arabia at little or no cost, were employed in the development of the UHPC mixtures. A base mixture of UHPC without replacement of silica fume or sand was selected and a total of 24 trial mixtures of UHPC were prepared using different percentages of NP, FA, LSP, CKD, and PSS, partially replacing the silica fume and sand. Flow and 28-d compressive strength of each UHPC mixture were determined to finally select those mixtures, which satisfied the minimum flow and strength criteria of UHPC. The test results showed that the utilization of NP, FA, LSP, CKD, and PSS in production of UHPC is possible with acceptable flow and strength. A total of 10 UHPC mixtures were identified with flow and strength equal to or more than the minimum required.

Fra kollegial supervision til fællesfaglig udvikling - et eksperiment med entreprenørskabsundervisning i faget Kulturformidling

DEFF Research Database (Denmark)

Elbeshausen, Hans; Jensen, Agnete Lunddahl; Riis, Ragnhild

2013-01-01

. Deres involvering viste sig i dialogiske interventioner i undervisningens form og indhold. This article presents an explorative journey carried out by a team of teachers. The aim was to develop their teaching methods in master courses in communication by integrating entrepreneurial thinking. The focus......Artiklen handler om at tilegne sig viden om entreprenørskab som undervisningsform gennem en eksperimentel praksis. Vi beskriver udfordringer, dilemmaer, erfaringer og vendepunkter i forløbet og forklarer, hvordan fokus i den kollegiale supervision flyttede til at udvikle faglighed i fællesskab....... Forløbets eksplorative og fleksible form blev ledsaget af dialog på flere niveauer og inddrog både de studerende og alle undervisere. Målene kunne præciseres og ændres, og institutionens faglighed udvides. Med metaforen ’tvillinger’ blev kolleger indbudt til særligt at følge underviserne i eksperimentet...

The effects of prioritize inspections on occupational health hazards control in workplaces in Iran.

Science.gov (United States)

Sadeghi, Fatemah; Bahrami, Abdolrahman; Fatemi, Farin

2014-01-01

Iran, a newly industrializing country in Middle East, has a workforce of 25 million people. Most employees are working in agriculture, manufacturing, services, construction, commerce sectors, carpet weaving and mining. This article aims to explore the improvement of occupational harmful agents in workplaces due to implement "prioritize inspections". In 2012, the system of "prioritize inspections "was defined for surveillance on enterprises replace of routine inspection. From this system, the enterprises classified on four groups based on health hazards and enterprises with high risk were under more surveillance. The information about each enterprise was collected by health centers, in five provinces and reported by a recommended form to Centre of Environmental and Occupational Health (CEOH). At this program, the inspections from high and medium hazards were increased in all of provinces. The results showed there was a significant difference between the control of health hazards in before and after beginning of "prioritize inspections"(P=0.048). The control of noise, fumes and providing of proper illumination increased from 8 to 10%, 9 to 9.5%, 12.9 to 15.4%, respectively, at under study provinces in 2012 compared to 2011. The surveillance based on "prioritize inspections" increased the quality of occupational health inspections that causes to prevent occupational health diseases.

Synthesis and comparison of mechanical behavior of fly ash-epoxy and silica fumes-epoxy composite

Science.gov (United States)

Sangamesh; Ravishankar, K. S.; Kulkarni, S. M.

2017-08-01

Present day innovation requires materials with a typical combination of properties that are not possible by conventional metal, alloys, ceramics and polymeric materials. Particulate reinforcements for polymers are selected with the dual objective of improving composite properties and save on the total cost of the system. The point of this study is to utilize and compare the mechanical properties of filler (fly ash and silica fumes) reinforced epoxy composites. The composites of different proportions by percentage of matrix (100%), fillers (5%, 10% and 15%) volume are developed using hand lay-up process are tested for tensile and compression, according to ASTM Standards. From these mechanical properties, the flexural analysis of these composites is simulated. And which are characterized by Scanning electron microscopy for the fracture surface study, which reveals the brittle fracture, this also conforms from the Finite element analysis (FEA). And the overall mechanical properties of the fly ash reinforced polymer composites were found to have better than silica fumes reinforced composites.

Assessment of aggregates- cement paste border in concretes containing silica fume and fly ash

Directory of Open Access Journals (Sweden)

Ali Sademomtazi

2017-12-01

Full Text Available The bond between aggregate and cement paste, called the interfacial transition zone (ITZ is an important parameter that effect on the mechanical properties and durability of concrete. Transition zone microstructure and porosity (pores of cement paste or concrete are affected by the type and properties of materials used which evaluated in this research. On the other hand, the use of efficient, low-cost and reliable method is particularly important for evaluating of concrete performance against the chloride ion penetration and its relationships with transition zone as a suitable index to assess the durability. So far, various methods to approach the electrical Indices are presented. In this research, the effect of pozzolanic materials fly ash (10%, 20% and 30% and silica fume (5% and 10% as substitute of cement by weight in binary and ternary mixtures on the fresh and hardened concrete properties were investigated. To determine mechanical properties, the compressive strength, splitting tensile strength and modulus of elasticity tests were performed. Also, water penetration depth, porosity, water sorptivity, specific electrical resistivity, rapid chloride penetration test (RCPT and rapid chloride migration test (RCMT tests were applied to evaluate concrete durability. To examine the border of aggregate and cement paste morphology of concrete specimens, scanning electron microscope images (SEM was used. The fresh concrete results showed that the presence of silica fume in binary and ternary mixtures reduced workability and air content but fly ash increased them. Adding silica fume to mixtures of containing flay ash while increasing mechanical strength reduced the porosity and pores to 18%. The presence of pozzolanic materials in addition to increasing bond quality and uniformity of aggregate-cement matrix border a considerably positive effect on the transport properties of concrete.

Engineered nanomaterials: exposures, hazards, and risk prevention

Directory of Open Access Journals (Sweden)

MacPhail Robert C

2011-03-01

Full Text Available Abstract Nanotechnology presents the possibility of revolutionizing many aspects of our lives. People in many settings (academic, small and large industrial, and the general public in industrialized nations are either developing or using engineered nanomaterials (ENMs or ENM-containing products. However, our understanding of the occupational, health and safety aspects of ENMs is still in its formative stage. A survey of the literature indicates the available information is incomplete, many of the early findings have not been independently verified, and some may have been over-interpreted. This review describes ENMs briefly, their application, the ENM workforce, the major routes of human exposure, some examples of uptake and adverse effects, what little has been reported on occupational exposure assessment, and approaches to minimize exposure and health hazards. These latter approaches include engineering controls such as fume hoods and personal protective equipment. Results showing the effectiveness - or lack thereof - of some of these controls are also included. This review is presented in the context of the Risk Assessment/Risk Management framework, as a paradigm to systematically work through issues regarding human health hazards of ENMs. Examples are discussed of current knowledge of nanoscale materials for each component of the Risk Assessment/Risk Management framework. Given the notable lack of information, current recommendations to minimize exposure and hazards are largely based on common sense, knowledge by analogy to ultrafine material toxicity, and general health and safety recommendations. This review may serve as an overview for health and safety personnel, management, and ENM workers to establish and maintain a safe work environment. Small start-up companies and research institutions with limited personnel or expertise in nanotechnology health and safety issues may find this review particularly useful.

Kvalitativ og kvantitativ kortlægning af potentialer og barrierer for udvikling af blended learning-uddannelser på Ingeniørhøjskolen i København

DEFF Research Database (Denmark)

Gynther, Karsten; Christensen, Ove; Frederiksen, Jan

Denne rapport kortlægger behovet for at udvikle fleksible diplomingeniøruddannelser og et fleksibelt adgangskursus til Ingeniørhøjskolens uddannelser i Ballerup. Rapporten udpeger nye brugerprofiler og heraf følgende designprincipper for, hvordan en blended learning uddannelse kan tilrettelægges i...... tilrettelæggelse af blended learning koncepter, der matcher nye brugergruppers behov og vilkår. Som sådan kan undersøgelsen læses som et casestudium med bred relevans for alle uddannelsestyper i den danske uddannelsessektor....

发烟硫酸浓度互换公式的推导%Derivation about Concentrations Exchanging Formula of Fuming Sulphuric Acid

Institute of Scientific and Technical Information of China (English)

谭靖辉; 唐淑贞

2011-01-01

指出发烟硫酸是游离态SO3的H2SO4溶液,运用质量守恒定律对发烟硫酸浓度互换公式进行了推导,阐述了使用该公式的注意事项。%Fuming sulphuric acid was regarded as SO3 of free state in sulfuric acid solution,concentrations exchanging formula of fuming sulphuric acid was deduced by mass conservation law,attentions of formula were expounded.

An Accelerated Test Method of Simultaneous Carbonation and Chloride Ion Ingress: Durability of Silica Fume Concrete in Severe Environments

Directory of Open Access Journals (Sweden)

S. A. Ghahari

2016-01-01

Full Text Available The effects of simultaneous carbonation and chloride ion attack on mechanical characteristics and durability of concrete containing silica fume have been investigated through an accelerated test method. Specimens containing different amounts of silica fume were maintained in an apparatus in which carbon dioxide pressure and concentration and relative humidity were kept constant, and wetting and drying cycles in saline water were applied. Surface resistivity, sorptivity, CO2 consumption, and carbonation and chloride ion ingress depths measurements were taken. Phase change due to carbonation and chloride ion attack was monitored by XRD analysis, and microstructures and interfacial transition zones were studied by implementing SEM as well as mercury intrusion porosimetry. It was expected to have a synergistic effect in the tidal zone where simultaneous carbonation and chloride ion attack happen. However, the observed reduced surface resistivity, compared to specimens maintained in CO2 gas, could be due to the moisture that is available near the surface, hindering CO2 from penetrating into the pores of the specimens. Moreover, the porosity analysis of the specimens showed that the sample containing silica fume cured in the tidal zone had 50.1% less total porosity than the plain cement paste cured in the same condition.

Design and analysis on fume exhaust system of blackbody cavity sensor for continuously measuring molten steel temperature

Directory of Open Access Journals (Sweden)

Guohui Mei

2017-03-01

Full Text Available Fume exhaust system is the main component of the novel blackbody cavity sensor with a single layer tube, which removes the fume by gas flow along the exhaust pipe to keep the light path clean. However, the gas flow may break the conditions of blackbody cavity and results in the poor measurement accuracy. In this paper, we analyzed the influence of the gas flow on the temperature distribution of the measuring cavity, and then calculated the integrated effective emissivity of the non-isothermal cavity based on Monte-Carlo method, accordingly evaluated the sensor measurement accuracy, finally obtained the maximum allowable flow rate for various length of the exhaust pipe to meet the measurement accuracy. These results will help optimize the novel blackbody cavity sensor design and use it better for measuring the temperature of molten steel.

Effects of boundary-layer separation controllers on a desktop fume hood.

Science.gov (United States)

Huang, Rong Fung; Chen, Jia-Kun; Hsu, Ching Min; Hung, Shuo-Fu

2016-10-02

A desktop fume hood installed with an innovative design of flow boundary-layer separation controllers on the leading edges of the side plates, work surface, and corners was developed and characterized for its flow and containment leakage characteristics. The geometric features of the developed desktop fume hood included a rearward offset suction slot, two side plates, two side-plate boundary-layer separation controllers on the leading edges of the side plates, a slanted surface on the leading edge of the work surface, and two small triangular plates on the upper left and right corners of the hood face. The flow characteristics were examined using the laser-assisted smoke flow visualization technique. The containment leakages were measured by the tracer gas (sulphur hexafluoride) detection method on the hood face plane with a mannequin installed in front of the hood. The results of flow visualization showed that the smoke dispersions induced by the boundary-layer separations on the leading edges of the side plates and work surface, as well as the three-dimensional complex flows on the upper-left and -right corners of the hood face, were effectively alleviated by the boundary-layer separation controllers. The results of the tracer gas detection method with a mannequin standing in front of the hood showed that the leakage levels were negligibly small (≤0.003 ppm) at low face velocities (≥0.19 m/s).

Influence of silica fume on mechanical and physical properties of recycled aggregate concrete

OpenAIRE

Çakır, Özgür; Sofyanlı, Ömer Özkan

2015-01-01

Several studies related to sustainable concrete construction have encouraged development of composite binders, involving Portland cement, industrial by-products, and concrete mixes with partial replacement of natural aggregate with recycled aggregate. In this paper, the effects of incorporating silica fume (SF) in the concrete mix design to improve the quality of recycled aggregates in concrete are presented. Portland cement was replaced with SF at 0%, 5% and 10%. Specimens were manufactured ...

Frankincense and myrrh essential oils and burn incense fume against micro-inhabitants of sacral ambients. Wisdom of the ancients?

Science.gov (United States)

Ljaljević Grbić, Milica; Unković, Nikola; Dimkić, Ivica; Janaćković, Peđa; Gavrilović, Milan; Stanojević, Olja; Stupar, Miloš; Vujisić, Ljubodrag; Jelikić, Aleksa; Stanković, Slaviša; Vukojević, Jelena

2018-03-09

Essential oils obtained from resins of Boswellia carteri Birdw. and Commiphora myrrha (Nees) Engl., commonly known as frankincense and true myrrh respectively, have been used extensively since 2800 BCE for the treatment of skin sores, wounds, teeth, inflammation, and urinary tract diseases in traditional medicine; for preparation of mummification balms and unguents; and also as incense and perfumes. Since ancient times, burning of frankincense and myrrh in places of worship for spiritual purposes and contemplation (a ubiquitous practice across various religions) had hygienic functions, to refine the smell and reduce contagion by purifying the indoor air. The general purpose of the study was to assess the in vitro antimicrobial potential of the liquid and vapour phases of B. carteri and C. myrrha essential oils and burn incense, as well as to test the effectiveness of their in situ application to cleanse microbially-contaminated air within the ambient of an investigated 17th-century church. The chemical composition of B. carteri and C. myrrha essential oils, obtained by hydrodistillation of frankincense and true myrrh oleo gum resins was determined using GC/MS, and antimicrobial properties of their liquid and vapour phases were assessed by the broth microdilution and microatmosphere diffusion methods. Chemical analysis of burn incense fume obtained using bottle gas washing with dichloromethane as a solvent was performed by GC/MS, while its antimicrobial activity was evaluated using a modified microatmosphere diffusion method to evaluate germination inhibition for fungi and CFU count reduction for bacteria. The in situ antimicrobial activity of B. carteri burn incense and essential oil vapour phase was assessed in the sealed nave and diaconicon of the church, respectively. The dominant compounds of B. carteri EO were α-pinene (38.41%) and myrcene (15.21%), while C. myrrha EO was characterized by high content of furanoeudesma-1,3-diene (17.65%), followed by curzerene

Occupational exposure to solvents, metals and welding fumes and risk of Parkinson's disease.

Science.gov (United States)

van der Mark, Marianne; Vermeulen, Roel; Nijssen, Peter C G; Mulleners, Wim M; Sas, Antonetta M G; van Laar, Teus; Huss, Anke; Kromhout, Hans

2015-06-01

The aim of this study was to investigate the potential association between occupational exposure to solvents, metals and/or welding fumes and risk of developing Parkinson's disease (PD). Data of a hospital based case-control study including 444 PD patients and 876 age and sex matched controls was used. Occupational histories and lifestyle information of cases and controls were collected in a structured telephone interview. Exposures to aromatic solvents, chlorinated solvents and metals were estimated by linking the ALOHA+ job-exposure matrix to the occupational histories. Exposure to welding fumes was estimated using self-reported information on welding activities. No statistically significant associations with any of the studied metal and solvent exposures were found. However, for self-reported welding activities we observed non-statistically significant reduced risk estimates (third tertile cumulative exposure: OR = 0.51 (95% CI: 0.21-1.24)). The results of our study did not provide support for an increased chance on developing PD after occupational exposure to aromatic solvents, chlorinated solvents or exposure to metals. The results showed reduced risk estimates for welding, which is in line with previous research, but no clear explanation for these findings is available. Copyright © 2015 Elsevier Ltd. All rights reserved.

Manganese in exhaled breath condensate: a new marker of exposure to welding fumes.

Science.gov (United States)

Hulo, Sébastien; Chérot-Kornobis, Nathalie; Howsam, Mike; Crucq, Sébastien; de Broucker, Virginie; Sobaszek, Annie; Edme, Jean-Louis

2014-04-07

To evaluate manganese in exhaled breath condensate (Mn-EBC) as an indicator of exposure to fumes from metal inert gas welding process. We collected EBC and urine from 17 welders and 16 unexposed control subjects after 5 days exposure. Concentrations of manganese (Mn), nickel (Ni), iron (Fe) and chromium (Cr) were measured in EBC and urine samples and correlated with cumulative exposure indices for the working week (CIW) and for the total welding years (WY), based on duration of welding activity and atmospheric metal measurements. Concentrations of Mn and Ni in EBC were significantly higher among welders than controls whereas this difference was not significant for Mn in urine. Levels of Mn and Ni in EBC were not correlated with their respective levels in urine. The linear regressions found significant positive coefficients between Mn-EBC, Ni-EBC, Ni-U and Cr-U concentrations and the cumulative exposure indices. Taking into account tobacco use, statistical analysis showed the same trends except for the relationship between Mn-U and CIW. This pilot study showed that Mn-EBC, as well as Ni-EBC, can serve as reliable indices of occupational exposure to welding fumes and provide complimentary toxicokinetic information to that provided by urine analyses. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Human biomonitoring of chromium and nickel from an experimental exposure to manual metal arc welding fumes of low and high alloyed steel.

Science.gov (United States)

Bertram, Jens; Brand, Peter; Schettgen, Thomas; Lenz, Klaus; Purrio, Ellwyn; Reisgen, Uwe; Kraus, Thomas

2015-05-01

The uptake and elimination of metals from welding fumes is currently not fully understood. In the Aachen Workplace Simulation Laboratory (AWSL) it is possible to investigate the impact of welding fumes on human subjects under controlled exposure conditions. In this study, the uptake and elimination of chromium or chromium (VI) respectively as well as nickel was studied in subjects after exposure to the emissions of a manual metal arc welding process using low or high alloyed steel. In this present study 12 healthy male non-smokers, who never worked as welders before, were exposed for 6h to welding fumes of a manual metal arc welding process. In a three-fold crossover study design, subjects were exposed in randomized order to either clean air, emissions from welding low alloyed steel, and emissions from welding high alloyed steel. Particle mass concentration of the exposure aerosol was 2.5mg m(-3). The content of chromium and nickel in the air was determined by analysing air filter samples on a high emission scenario. Urine analysis for chromium and nickel was performed before and after exposure using methods of human biomonitoring. There were significantly elevated chromium levels after exposure to welding fumes from high alloyed steel compared to urinary chromium levels before exposure to high alloyed welding fumes, as well as compared to the other exposure scenarios. The mean values increased from 0.27 µg l(-1) to 18.62 µg l(-1). The results were in good agreement with already existing correlations between external and internal exposure (German exposure equivalent for carcinogenic working materials EKA). The variability of urinary chromium levels was high. For urinary nickel no significant changes could be detected at all. Six-hour exposure to 2.5mg m(-3) high alloyed manual metal arc welding fumes lead to elevated urinary chromium levels far higher (7.11-34.16 µg l(-1)) than the German biological exposure reference value (BAR) of 0.6 µg l(-1) directly after

Abrasion Properties of Steel Fiber Reinforced Silica Fume Concrete According to Los Angeles and Water Abrasion Tests

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Tsan-Ching CHENG

2014-12-01

Full Text Available The current study mainly investigated the influence of different tests on the abrasion resistance of concrete mixed with steel fibers and silica fume. The abrasion resistance was assessed at 28, 56 and 91 days on concretes with water-binder ratios of 0.35 and 0.55 where in some mixes silica fume was substituted by 5 % of cement by weight. Steel fibers of 0.5 % and 1.0 % of concrete volume were also added into the test concrete by replacement of coarse and fine aggregates. The results showed that concrete with higher compressive strength in Los Angeles abrasion tests also had better abrasion resistance. The inclusion of steel fibers into test concrete with a water-binder ratio of 0.35 resulted in a significant increase in compressive strength. This concrete also displayed better abrasion resistance and splitting tensile strength than reference concrete; in the test sample with a water-binder ratio of 0.55, the added steel fibers was unable to effectively produce cementation with the concrete. The inclusion of silica fume improved the abrasion resistance of concretes. In water abrasion testing, the abrasion resistance of concrete containing steel fiber was worse than that of concrete without steel fibers. In the water abrasion testing, the surface of steel fiber reinforced concrete was eroded by water and steel balls, and the impact caused the steel fibers to separate from the concrete and led to higher wear loss. DOI: http://dx.doi.org/10.5755/j01.ms.20.4.6460

Experimental and numerical investigation of form-stable dodecane/hydrophobic fumed silica composite phase change materials for cold energy storage

International Nuclear Information System (INIS)

Chen, Jiajie; Ling, Ziye; Fang, Xiaoming; Zhang, Zhengguo

2015-01-01

Highlights: • Form-stable dodecane/fumed silica composite for cold storage is prepared. • A suggesting hypothesis that explains infiltration mechanism is proposed. • The performance of the composite phase change material is investigated. • Numerical simulation of system is carried out and results fit well. - Abstract: A kind of form-stable composite phase change materials used for cold thermal energy storage is prepared by absorbing dodecane into the hydrophobic fumed silica. With relatively suitable pore diameter and hydrophobic groups, hydrophobic fumed silica is beneficial to the penetration and infiltration of dodecane and the leakage problem solving. Scanned by electron micrographs and Fourier transformation infrared, the composite phase change material is characterized to be just physical penetration. Besides, the differential scanning calorimeter and thermo gravimetric analysis reveals the high enthalpy, good thermal stability and cycling performance of this composite phase change material. What’s more, Hot-Disk thermal constants analyzer demonstrates that the composite phase change material has low thermal conductivity which is desired in cold storage application. In the experiment, a cold energy storage system is set up and the results from the experiment show that the system has excellent performance of cold storage by incorporating composite phase change material. Apart from that, the experimental data is found to have a great agreement with the numerical simulation which is carried out by using the commercial computational fluid dynamics software FLUENT.

A Cross-Sectional Study of the Cardiovascular Effects of Welding Fumes.

Directory of Open Access Journals (Sweden)

Huiqi Li

Full Text Available Occupational exposure to particulate air pollution has been associated with an increased risk of cardiovascular disease. However, the risk to welders working today remains unclear. We aimed to elucidate the cardiovascular effects of exposure to welding fumes.In a cross-sectional study, structured interviews and biological sampling were conducted for 101 welders and 127 controls (all non-smoking males from southern Sweden. Personal breathing zone sampling of respirable dust was performed. Blood pressure (BP and endothelial function (using peripheral arterial tonometry were measured. Plasma and serum samples were collected from peripheral blood for measurement of C-reactive protein, low-density lipoprotein, homocysteine, serum amyloid A, and cytokines.Welders were exposed to 10-fold higher levels of particles than controls. Welders had significantly higher BP compared to controls, an average of 5 mm Hg higher systolic and diastolic BP (P ≤ 0.001. IL-8 was 3.4 ng/L higher in welders (P=0.010. Years working as a welder were significantly associated with increased BP (β=0.35, 95%CI 0.13 - 0.58, P=0.0024 for systolic BP; β=0.32, 95%CI 0.16 - 0.48, P<0.001 for diastolic BP, adjusted for BMI but exposure to respirable dust was not associated with BP. No clear associations occurred between welding and endothelial function, or other effect markers.A modest increase in BP was found among welders compared to controls suggesting that low-to-moderate exposure to welding fumes remains a risk factor for cardiovascular disease.

Strength and Mechanical Properties of High Strength Cement Mortar with Silica Fume

OpenAIRE

川上, 英男; 谷, 康博

1993-01-01

Two series of tests were carried out to clarify the effects of silica fume on the strength and mechanical properties of cement mortar. The test specimens of cement mortar were prepared within the flow values between 180 mm and 240 mm which qualifies better workability of the concrete. The fiow values were attained by using superplasticizer. The specimens were tested at the age of 4 weeks. Main results of the experiments are as follows. 1. At a given cement water ratio,the larger volume of sil...

Sugar Dehydration without Sulfuric Acid: No More Choking Fumes in the Classroom!

Science.gov (United States)

Silverstein, Todd P.; Zhang, Yi

1998-06-01

Sugar is a common reagent often used in colorful classroom demonstrations. It produces a growing column of black ash when dehydrated by concentrated sulfuric acid, and it produces a brilliant purple flame when combusted with potassium chlorate. Unfortunately, both of these reactions also produce copious quantities of noxious fumes which make them problematic as lecture demonstrations. We have modified and combined these two reactions. Our demonstration uses no sulfuric acid, yields relatively little smoke, and produces an exciting and unpredictable growing column of black carbon.

Fluorine content of plants in air-polluted and fume-free areas

Energy Technology Data Exchange (ETDEWEB)

Daessler, H G

1969-01-01

Comparative analysis of plants (including orchard and forest trees) on different soil types in a polluted area, with a known quantitative emission of waste gases from a particular factory, and from a fume-free area, showed the quantitative chemical analysis of plant parts to be a satisfactory method of assessing amounts of F in the atmosphere, and its spatial distribution. The degree of injury, as shown by leaf discoloration and necrosis, was not always directly related to the degree of air pollution, since injury varied with soil type and the nutrient status of the plant. 11 references, 2 figures, 3 tables.

Upgrading offshore pipelines concrete coated by silica fume additive against aggressive mechanical laying

OpenAIRE

M.I. Abdou; Hesham Abuseda

2016-01-01

Studies have been carried out to investigate the possibility of utilizing a broad range of micro-silica partial additions with cement in the production of concrete coating. This study investigated the strength properties and permeability of micro-silica concrete to achieve resistance toward concrete cracking and damage during laying. The chemical composition of micro-silica (silica fume) was determined, and has been conducted on concrete mixes with additions of 3 up to 25% by weight of cement...

Effects of using silica fume and polycarboxylate-type superplasticizer on physical properties of cementitious grout mixtures for semiflexible pavement surfacing.

Science.gov (United States)

Koting, Suhana; Karim, Mohamed Rehan; Mahmud, Hilmi; Mashaan, Nuha S; Ibrahim, Mohd Rasdan; Katman, Herdayati; Husain, Nadiah Md

2014-01-01

Semi-flexible pavement surfacing is a composite pavement that utilizes the porous pavement structure of the flexible bituminous pavement, which is subsequently grouted with appropriate cementitious materials. This study aims to investigate the compressive strength, flexural strength, and workability performance of cementitious grout. The grout mixtures are designed to achieve high strength and maintain flow properties in order to allow the cement slurries to infiltrate easily through unfilled compacted skeletons. A paired-sample t-test was carried out to find out whether water/cement ratio, SP percentages, and use of silica fume influence the cementitious grout performance. The findings showed that the replacement of 5% silica fume with an adequate amount of superplasticizer and water/cement ratio was beneficial in improving the properties of the cementitious grout.

Exposure of Petrol Station Attendants and Auto Mechanics to Premium Motor Sprit Fumes in Calabar, Nigeria

Directory of Open Access Journals (Sweden)

N. E. Udonwa

2009-01-01

Full Text Available A population-based-cross-sectional survey was carried out to investigate the potential risk of exposure to premium motor spirit (PMS fumes in Calabar, Nigeria, among Automobile Mechanics (AM, Petrol Station Attendants (PSA and the general population. Structured questionnaire was administered on the randomly chosen subjects to elicit information on their exposure to PMS. Duration of exposure was taken as the length of work in their various occupations. Venous blood was taken for methaemoglobin (MetHb and packed cells volume (PCV. Mean MetHb value was higher in AM (7.3% and PSA (5.8% than in the subjects from the general population (2.7%. PCV was lower in PSA (30.8%, than AM (33.3% and the subjects from the general population (40.8%. MetHb level was directly proportional, and PCV inversely related, to the duration of exposure. The study suggested increased exposure to petrol fumes among AM, PSA, and MetHb as a useful biomarker in determining the level of exposure to benzene in petrol vapour.

42 CFR 84.1151 - DOP filter test; respirators designed as respiratory protection against dusts, fumes, and mists...

Science.gov (United States)

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false DOP filter test; respirators designed as... filter test; respirators designed as respiratory protection against dusts, fumes, and mists having an air...) All single air-purifying respirator filter units will be tested in an atmosphere concentration of 100...

The effect of silica fume on early hydration of white Portland cement via fast field cycling-NMR relaxometry

Science.gov (United States)

Badea, Codruţa.; Bede, Andrea; Ardelean, Ioan

2017-12-01

Fast Field Cycling (FFC) nuclear magnetic resonance (NMR) relaxometry is used to monitor the influence introduced on the hydration process by the addition of silica fume in a cement paste mixture, prepared with white Portland cement. The FFC relaxometry technique was implemented due to its sensitivity to a wider range of molecular motions, which gives more information than other relaxometry techniques performed at a fixed frequency. This unique feature of FFC relaxometry allows better separation of the surface and bulk contributions from the global measured relaxation rate. The relaxation process is dominated by the interaction of water protons with the paramagnetic centers located on the surface of cement grains. In the frame of a two-phase exchange model, this allows the monitoring of the influence of an addition of silica fume on the evolution of surface-to-volume ratio during the early hydration stages.

Environmental lead hazard to children.

Science.gov (United States)

Mittal, S K

1992-01-01

Clinically evident lead poisoning is rare in Indian children but is more common than in adults. In children, lead poisoning may appear as fever, seizures, anemia, or abdominal pain, while in adults it is more likely to manifest as chronic minor peripheral neuropathy or gum pigmentation. Children with acute lead poisoning can be treated with chelators such as EDTA and BAL, but many are left with permanent brain damage. The most common sources of acute lead poisoning in Indian children are inhalation of fumes from burned car batteries, ingestion of flaking paint, consuming food cooked in cheap aluminum or brass utensils, and eating contaminated soil. The sources of chronic lead poisoning are water from lead pipes and fumes from industrial or automotive exhaust. Another common source in India is application of "kajjal" to children's eyes. Sources of lead in Western countries, such as drinking water, canned food, residential paint, automotive fuel, and ambient air quality, are regulated by law. None of these are regulated in India.

A Review for Characterization of Silica Fume and Its Effects on Concrete Properties

OpenAIRE

Mohammad Panjehpour; Abang Abdullah Abang Ali; Ramazan Demirboga

2011-01-01

Mineral additions which are also known as mineral admixtures have been used in Portland cement for many years. There are two types of additions which are commonly mixed into the Portland clinker or blended directly with cement these days. They are crystalline, also known as hydraulically inactive additions and pozzolanic, which are hydraulically active additions. Silica fume is very reactive pozzolan, while it is used in concrete because of its fine particles, large surface area and high SiO2...

Effects of Using Silica Fume and Polycarboxylate-Type Superplasticizer on Physical Properties of Cementitious Grout Mixtures for Semiflexible Pavement Surfacing

Directory of Open Access Journals (Sweden)

Suhana Koting

2014-01-01

Full Text Available Semi-flexible pavement surfacing is a composite pavement that utilizes the porous pavement structure of the flexible bituminous pavement, which is subsequently grouted with appropriate cementitious materials. This study aims to investigate the compressive strength, flexural strength, and workability performance of cementitious grout. The grout mixtures are designed to achieve high strength and maintain flow properties in order to allow the cement slurries to infiltrate easily through unfilled compacted skeletons. A paired-sample t-test was carried out to find out whether water/cement ratio, SP percentages, and use of silica fume influence the cementitious grout performance. The findings showed that the replacement of 5% silica fume with an adequate amount of superplasticizer and water/cement ratio was beneficial in improving the properties of the cementitious grout.

Influence of Silica Fume Addition in the Long-Term Performance of Sustainable Cement Grouts for Micropiles Exposed to a Sulphate Aggressive Medium

Directory of Open Access Journals (Sweden)

José Marcos Ortega

2017-08-01

Full Text Available At present, sustainability is of major importance in the cement industry, and the use of additions such as silica fume as clinker replacement contributes towards that goal. Special foundations, and particularly micropiles, are one of the most suitable areas for the use of sustainable cements. The aim of this research is to analyse the effects in the very long-term (for 600 days produced by sulphate attack in the microstructure of grouts for micropiles in which OPC (ordinary Portland cement has been replaced by 5% and 10% silica fume. This line of study is building on a previous work, where these effects were studied in slag and fly ash grouts. Grouts made using a commercial sulphate-resisting Portland cement were also studied. The non-destructive impedance spectroscopy technique, mercury intrusion porosimetry, and Wenner resistivity testing were used. Mass variation and the compressive strength have also been analysed. Apparently, impedance spectroscopy is the most suitable technique for studying sulphate attack development. According to the results obtained, grouts for micropiles with a content of silica fume up to 10% and exposed to an aggressive sulphate medium, have a similar or even better behaviour in the very long-term, compared to grouts prepared using sulphate-resisting Portland cement.

The Prevalence of Selected Potentially Hazardous Workplace Exposures in the US: Findings From the 2010 National Health Interview Survey

Science.gov (United States)

Calvert, Geoffrey M.; Luckhaupt, Sara E.; Sussell, Aaron; Dahlhamer, James M.; Ward, Brian W.

2015-01-01

Objective Assess the national prevalence of current workplace exposure to potential skin hazards, secondhand smoke (SHS), and outdoor work among various industry and occupation groups. Also, assess the national prevalence of chronic workplace exposure to vapors, gas, dust, and fumes (VGDF) among these groups. Methods Data were obtained from the 2010 National Health Interview Survey (NHIS). NHIS is a multistage probability sample survey of the civilian non-institutionalized population of the US. Prevalence rates and their variances were calculated using SUDAAN to account for the complex NHIS sample design. Results The data for 2010 were available for 17,524 adults who worked in the 12 months that preceded interview. The highest prevalence rates of hazardous workplace exposures were typically in agriculture, mining, and construction. The prevalence rate of frequent handling of or skin contact with chemicals, and of non-smokers frequently exposed to SHS at work was highest in mining and construction. Outdoor work was most common in agriculture (85%), construction (73%), and mining (65%). Finally, frequent occupational exposure to VGDF was most common among mining (67%), agriculture (53%), and construction workers (51%). Conclusion We identified industries and occupations with the highest prevalence of potentially hazardous workplace exposures, and provided targets for investigation and intervention activities. PMID:22821700

Effects of cyanoacrylate fuming, time after recovery, and location of biological material on the recovery and analysis of DNA from post-blast pipe bomb fragments*.

Science.gov (United States)

Bille, Todd W; Cromartie, Carter; Farr, Matthew

2009-09-01

This study investigated the effects of time, cyanoacrylate fuming, and location of the biological material on DNA analysis of post-blast pipe bomb fragments. Multiple aliquots of a cell suspension (prepared by soaking buccal swabs in water) were deposited on components of the devices prior to assembly. The pipe bombs were then deflagrated and the fragments recovered. Fragments from half of the devices were cyanoacrylate fumed. The cell spots on the fragments were swabbed and polymerase chain reaction/short tandem repeat analysis was performed 1 week and 3 months after deflagration. A significant decrease in the amount of DNA recovered was observed between samples collected and analyzed within 1 week compared with the samples collected and analyzed 3 months after deflagration. Cyanoacrylate fuming did not have a measurable effect on the success of the DNA analysis at either time point. Greater quantities of DNA were recovered from the pipe nipples than the end caps. Undeflagrated controls showed that the majority (>95%) of the DNA deposited on the devices was not recovered at a week or 3 months.

Compaction and Collapse Characteristics of Dune Sand Stabilized with Lime-Silica Fume Mix

Directory of Open Access Journals (Sweden)

Mohammed Y. Fattah

2016-04-01

Full Text Available The purpose of this research is to assess the suitability of dune sands as construction materials. Moreover, such a goal is considered beneficial in determining appropriate methods for soil stabilization or ground improvement and to assessing the suitability of dune sands as subgrade layer for carrying roads and rail foundation. Dune sand samples were collected from a region in Baiji area in Salah-Aldeen governorate, North of Iraq. A grey-colored densified silica fume (SF and lime (L are used. Three percentages are used for lime (3%, 6%, and 9%, and four rates are used for silica fume (3%, 6%, 9% and 12% and the maximum percentage of silica fume is mixed with the proportions of lime. Unsoaked California Bearing Ratio (CBR on compacted dune sands treated dune sands with L-SF by mixing and cured for one day. The increasing in CBR ranged between 443 – 707% at 2.54 mm penetration and 345 – 410% at 5.08 mm penetration.     Resumen El propósito de esta investigación es evaluar el uso de arena de dunas como materiales de construcción. Además, este objetivo permite determinar los métodos apropiados para la estabilización del suelo, el mejoramiento del terreno y la evaluación de pertinencia de la arena de dunas en capas subbase para carreteras y cimientos férreos. Se recolectaron muestras de arena de dunas en el área de Baiji, del comisionado Salah-Aldeen, al norte de Irak. Se utilizó vapor de óxido de silicio (SF, en inglés, grisáceo y densificado, y óxido de calcio (L. Se utilizaron tres porcentajes para el óxido de calcio (3 %, 6 % y 9 %, y cuatro para el óxido de silicio (3 %, 6 %,  9% y 12% y el máximo porcentaje del óxido de silicio se mezcló con las proporciones de óxido de calcio. Se realizó en seco el Ensayo de Relación de Soporte de California (del inglés California Bearing Ratio, CBR en arena de dunas compactada y tratada con la mezcla L-SF curada durante un día. El incremento en el ensayo CBR osciló entre 443

1-Hydroxypyrene Levels in Blood Samples of Rats After Exposure to Generator Fumes

Science.gov (United States)

Ifegwu, Clinton; Igwo-Ezikpe, Miriam N.; Anyakora, Chimezie; Osuntoki, Akinniyi; Oseni, Kafayat A.; Alao, Eragbae O.

2013-01-01

Polynuclear Aromatic Hydrocarbons (PAHs) are a major component of fuel generator fumes. Carcinogenicity of these compounds has long been established. In this study, 37 Swiss albino rats were exposed to generator fumes at varied distances for 8 hours per day for a period of 42 days and the level of 1-hydroxypyrene in their blood was evaluated. This study also tried to correlate the level of blood 1-hyroxypyrene with the distance from the source of pollution. Plasma was collected by centrifuging the whole blood sample followed by complete hydrolysis of the conjugated 1-hydroxypyrene glucuronide to yield the analyte of interest, 1-hydroxypyrene, which was achieved using beta glucuronidase. High performance liquid chromatography (HPLC) with UV detector was used to determine the 1-hydroxypyrene concentrations in the blood samples. The mobile phase was water:methanol (12:88 v/v) isocratic run at the flow rate of 1.2 mL/min with CI8 stationary phase at 250 nm. After 42 days of exposure, blood concentration level of 1-hydroxypyrene ranged from 34 μg/mL to 26.29 μg/mL depending on the distance from source of exposure. The control group had no 1-hydroxypyrene in their blood. After the period of exposure, percentage of death correlated with the distance from the source of exposure. Percentage of death ranged from 56% to zero depending on the proximity to source of pollution. PMID:24179393

Numerical analysis of the influence of particle charging on the fume formation process in arc welding

International Nuclear Information System (INIS)

Tashiro, Shinichi; Matsui, Sho; Tanaka, Manabu; Murphy, Anthony B

2013-01-01

In order to clarify the influence of electrostatic forces caused by charging of particles on the coagulation process in fume formation in arc welding, a previously developed fume formation model is modified to consider the influence of charging, for both local thermodynamic equilibrium (LTE) and non-LTE conditions. The model takes into account formation of the particles from metal vapour by nucleation, growth of the particles by condensation of metal vapour and coagulation of the particles by collisions to form secondary particles. Results are obtained for both ballistic and Brownian motion of the particles. It is found that the growth of secondary particles is suppressed when the average particle charge becomes significant, because charging of the particle hinders collisions among secondary particles through the strong repulsive electrostatic force. Furthermore, deviations from LTE strongly affect the coagulation process, because the increased electron density at a given gas temperature increases the charging of particles. Brownian motion leads to larger secondary particles, since the average particle speed is increased. The influence of Brownian motion and particle charging cancel each other to a large extent, particularly when deviations from LTE are considered. (paper)

Assessment of the biological effects of welding fumes emitted from metal inert gas welding processes of aluminium and zinc-plated materials in humans.

Science.gov (United States)

Hartmann, L; Bauer, M; Bertram, J; Gube, M; Lenz, K; Reisgen, U; Schettgen, T; Kraus, T; Brand, P

2014-03-01

The aim of this study was to investigate biological effects and potential health risks due to two different metal-inert-gas (MIG) welding fumes (MIG welding of aluminium and MIG soldering of zinc coated steel) in healthy humans. In a threefold cross-over design study 12 male subjects were exposed to three different exposure scenarios. Exposures were performed under controlled conditions in the Aachener Workplace Simulation Laboratory (AWSL). On three different days the subjects were either exposed to filtered ambient air, to welding fumes from MIG welding of aluminium, or to fumes from MIG soldering of zinc coated materials. Exposure was performed for 6 h and the average fume concentration was 2.5 mg m(-3). Before, directly after, 1 day after, and 7 days after exposure spirometric and impulse oscillometric measurements were performed, exhaled breath condensate (EBC) was collected and blood samples were taken and analyzed for inflammatory markers. During MIG welding of aluminium high ozone concentrations (up to 250 μg m(-3)) were observed, whereas ozone was negligible for MIG soldering. For MIG soldering, concentrations of high-sensitivity CRP (hsCRP) and factor VIII were significantly increased but remained mostly within the normal range. The concentration of neutrophils increased in tendency. For MIG welding of aluminium, the lung function showed significant decreases in Peak Expiratory Flow (PEF) and Mean Expiratory Flow at 75% vital capacity (MEF 75) 7 days after exposure. The concentration of ristocetin cofactor was increased. The observed increase of hsCRP during MIG-soldering can be understood as an indicator for asymptomatic systemic inflammation probably due to zinc (zinc concentration 1.5 mg m(-3)). The change in lung function observed after MIG welding of aluminium may be attributed to ozone inhalation, although the late response (7 days after exposure) is surprising. Copyright © 2013 Elsevier GmbH. All rights reserved.

Exposure to rubber fume and rubber process dust in the general rubber goods, tyre manufacturing and retread industries.

Science.gov (United States)

Dost, A A; Redman, D; Cox, G

2000-08-01

This study assesses the current patterns and levels of exposure to rubber fume and rubber process dust in the British rubber industry and compares and contrasts the data obtained from the general rubber goods (GRG), retread tire (RT) and new tire (NT) sectors. A total of 179 rubber companies were visited and data were obtained from 52 general rubber goods, 29 retread tire and 7 new tire manufacturers. The survey was conducted using a questionnaire and included a walk-through inspection of the workplace to assess the extent of use of control measures and the nature of work practices being employed. The most recent (predominantly 1995-97) exposure monitoring data for rubber fume and rubber process dust were obtained from these companies; no additional sampling was conducted for the purpose of this study. In addition to the assessment of exposure data, evaluation of occupational hygiene reports for the quality of information and advice was also carried out.A comparison of the median exposures for processes showed that the order of exposure to rubber fume (E, in mg m(-3)) is: E(moulding) (0.40) approximately E(extrusion) (0.33)>E(milling) (0.18) for GRG; E(press) (0. 32)>E(extrusion) (0.19)>E(autoclave) (0.10) for RT; and E(press) (0. 22) approximately E(all other) (0.22) for NT. The order of exposure to rubber fume between sectors was E(GRG) (0.40)>E(RT) (0.32)>E(NT) (0.22). Median exposures to rubber process dust in the GRG was E(weighing) (4.2)>E(mixing) (1.2) approximately E(milling) (0.8) approximately E(extrusion) (0.8) and no significant difference (P=0. 31) between GRG and NT sectors. The findings compare well with the study carried out in the Netherlands [Kromhout et al. (1994), Annals of Occupational Hygiene 38(1), 3-22], and it is suggested that the factors governing the significant differences noted between the three sectors relate principally to the production and task functions and also to the extent of controls employed. Evaluation of occupational

The influence of blast furnace slag, fly ash and silica fume on corrosion of reinforced concrete in marine environment

NARCIS (Netherlands)

Polder, R.B.

1996-01-01

Chloride penetration from sea water may cause corrosion of reinforcement in concrete structures. Adding reactive inorganic materials such as blast furnace slag, fly ash or silica fume to the cement matrix improves the resistance against chloride penetration as compared to Portland cement concrete. A

Exposure to welding fumes and lower airway infection with Streptococcus pneumoniae.

Science.gov (United States)

Suri, Reetika; Periselneris, Jimstan; Lanone, Sophie; Zeidler-Erdely, Patti C; Melton, Geoffrey; Palmer, Keith T; Andujar, Pascal; Antonini, James M; Cohignac, Vanessa; Erdely, Aaron; Jose, Ricardo J; Mudway, Ian; Brown, Jeremy; Grigg, Jonathan

2016-02-01

Welders are at increased risk of pneumococcal pneumonia. The mechanism for this association is not known. The capacity of pneumococci to adhere to and infect lower airway cells is mediated by host-expressed platelet-activating factor receptor (PAFR). We sought to assess the effect of mild steel welding fumes (MS-WF) on PAFR-dependent pneumococcal adhesion and infection to human airway cells in vitro and on pneumococcal airway infection in a mouse model. The oxidative potential of MS-WF was assessed by their capacity to reduce antioxidants in vitro. Pneumococcal adhesion and infection of A549, BEAS-2B, and primary human bronchial airway cells were assessed by means of quantitative bacterial culture and expressed as colony-forming units (CFU). After intranasal instillation of MS-WF, mice were infected with Streptococcus pneumoniae, and bronchoalveolar lavage fluid (BALF) and lung CFU values were determined. PAFR protein levels were assessed by using immunofluorescence and immunohistochemistry, and PAFR mRNA expression was assessed by using quantitative PCR. PAFR was blocked by CV-3988, and oxidative stress was attenuated by N-acetylcysteine. MS-WF exhibited high oxidative potential. In A549 and BEAS-2B cells MS-WF increased pneumococcal adhesion and infection and PAFR protein expression. Both CV-3988 and N-acetylcysteine reduced MS-WF-stimulated pneumococcal adhesion and infection of airway cells. MS-WF increased mouse lung PAFR mRNA expression and increased BALF and lung pneumococcal CFU values. In MS-WF-exposed mice CV-3988 reduced BALF CFU values. Hypersusceptibility of welders to pneumococcal pneumonia is in part mediated by the capacity of welding fumes to increase PAFR-dependent pneumococcal adhesion and infection of lower airway cells. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. All rights reserved.

Computational Fluid Dynamics (CFD) Investigation of Submerged Combustion Behavior in a Tuyere Blown Slag-fuming Furnace

Science.gov (United States)

Huda, Nazmul; Naser, Jamal; Brooks, G. A.; Reuter, M. A.; Matusewicz, R. W.

2012-10-01

A thin-slice computational fluid dynamics (CFD) model of a conventional tuyere blown slag-fuming furnace has been developed in Eulerian multiphase flow approach by employing a three-dimensional (3-D) hybrid unstructured orthographic grid system. The model considers a thin slice of the conventional tuyere blown slag-fuming furnace to investigate details of fluid flow, submerged coal combustion dynamics, coal use behavior, jet penetration behavior, bath interaction conditions, and generation of turbulence in the bath. The model was developed by coupling the CFD with the kinetics equations developed by Richards et al. for a zinc-fuming furnace. The model integrates submerged coal combustion at the tuyere tip and chemical reactions with the heat, mass, and momentum interfacial interaction between the phases present in the system. A commercial CFD package AVL Fire 2009.2 (AVL, Graz, Austria) coupled with several user-defined subroutines in FORTRAN programming language were used to develop the model. The model predicted the velocity, temperature field of the molten slag bath, generated turbulence and vortex, and coal use behavior from the slag bath. The tuyere jet penetration length ( l P) was compared with the equation provided by Hoefele and Brimacombe from isothermal experimental work ( {{l_{{P}} }/{d_{o }} = 10.7( {N^' }_{Fr} } )^{0.46} ( {ρ_{{g}} /ρl } )^{0.35} } ) and found 2.26 times higher, which can be attributed to coal combustion and gas expansion at a high temperature. The jet expansion angle measured for the slag system studied is 85 deg for the specific inlet conditions during the simulation time studied. The highest coal penetration distance was found to be l/L = 0.2, where l is the distance from the tuyere tip along the center line and L is the total length (2.44 m) of the modeled furnace. The model also predicted that 10 pct of the injected coal bypasses the tuyere gas stream uncombusted and carried to the free surface by the tuyere gas stream, which

Mechanical and chemical properties of polyvinyl alcohol modified cement mortar with silica fume used as matrix including radioactive waste

International Nuclear Information System (INIS)

Dakroury, A. M.

2007-01-01

This paper discussed the mechanical and chemical properties of polyvinyl alcohol - modified cement mortar with silica fume to assess the safety for disposal of radioactive waste. The modified cement mortars containing polyvinyl alcohol (PVA) in the presence of 10 % silica fume (SF) .The chemical reaction between polymer and cement - hydrated product were investigated by the Infrared Spectral Technology, Differential Thermal Analysis and X-ray diffraction. The leaching of 137Cs from a waste composite into a surrounding fluid has been studied .The results shown that PVA increases the strength and decreases the porosity. The increase in strength duo to the interaction of PVA with cement , may be forming some new compound that fill the pores or improve the bond between the cement . The pozzolanic reaction of the SF increases the calcium silicate hydrates in the hardening matrix composites. There is distinct change in the refinement of the pore structure in cement composites giving fewer capillary pores and more of the finer gel pores

Lifetime occupational exposure to dusts, gases and fumes is associated with bronchitis symptoms and higher diffusion capacity in COPD patients

NARCIS (Netherlands)

Rodríguez, Esther; Ferrer, Jaume; Zock, Jan Paul|info:eu-repo/dai/nl/095184309; Serra, Ignasi; Antó, Josep M.; De Batlle, Jordi; Kromhout, Hans|info:eu-repo/dai/nl/074385224; Vermeulen, Roel|info:eu-repo/dai/nl/216532620; Donaire-González, David; Benet, Marta; Balcells, Eva; Monsó, Eduard; Gayete, Àngel; Garcia-Aymerich, Judith; Guerra, Stefano; Gea, Joaquim; Orozco-Levi, Mauricio; Vollmer, Ivan; Barberà, Joan Albert; Gómez, Federico P.; Paré, Carles; Roca, Josep; Rodriguez-Roisin, Robert; Agustí, Àlvar; Freixa, Xavier; Rodriguez, Diego A.; Gimeno, Elena; Portillo, Karina; Andreu, Jordi; Pallissa, Esther; Casan, Pere; Güell, Rosa; Giménez, Ana; Marín, Alicia; Morera, Josep; Farrero, Eva; Escarrabill, Joan; Ferrer, Antoni; Sauleda, Jaume; Togores, Bernat; Gáldiz, Juan Bautista; López, Lorena; Belda, José

2014-01-01

BACKGROUND: Occupational exposure to dusts, gases and fumes has been associated with reduced FEV1 and sputum production in COPD patients. The effect of occupational exposure on other characteristics of COPD, especially those reflecting emphysema, has not been studied in these patients.\

Lifetime occupational exposure to metals and welding fumes, and risk of glioma: a 7-country population-based case-control study.

Science.gov (United States)

Parent, Marie-Elise; Turner, Michelle C; Lavoué, Jérôme; Richard, Hugues; Figuerola, Jordi; Kincl, Laurel; Richardson, Lesley; Benke, Geza; Blettner, Maria; Fleming, Sarah; Hours, Martine; Krewski, Daniel; McLean, David; Sadetzki, Siegal; Schlaefer, Klaus; Schlehofer, Brigitte; Schüz, Joachim; Siemiatycki, Jack; van Tongeren, Martie; Cardis, Elisabeth

2017-08-25

Brain tumor etiology is poorly understood. Based on their ability to pass through the blood-brain barrier, it has been hypothesized that exposure to metals may increase the risk of brain cancer. Results from the few epidemiological studies on this issue are limited and inconsistent. We investigated the relationship between glioma risk and occupational exposure to five metals - lead, cadmium, nickel, chromium and iron- as well as to welding fumes, using data from the seven-country INTEROCC study. A total of 1800 incident glioma cases and 5160 controls aged 30-69 years were included in the analysis. Lifetime occupational exposure to the agents was assessed using the INTEROCC JEM, a modified version of the Finnish job exposure matrix FINJEM. In general, cases had a slightly higher prevalence of exposure to the various metals and welding fumes than did controls, with the prevalence among ever exposed ranging between 1.7 and 2.2% for cadmium to 10.2 and 13.6% for iron among controls and cases, respectively. However, in multivariable logistic regression analyses, there was no association between ever exposure to any of the agents and risk of glioma with odds ratios (95% confidence intervals) ranging from 0.8 (0.7-1.0) for lead to 1.1 (0.7-1.6) for cadmium. Results were consistent across models considering cumulative exposure or duration, as well as in all sensitivity analyses conducted. Findings from this large-scale international study provide no evidence for an association between occupational exposure to any of the metals under scrutiny or welding fumes, and risk of glioma.

Influence of smelter fumes on the growth of white pine in the Sudbury region

Energy Technology Data Exchange (ETDEWEB)

Linzon, S N

1958-01-01

An additional study was started in 1949 to determine the effects on neighboring white pine forests of sulfur fumes discharged from large smelters operated by two mining companies in the Sudbury district of Ontario. A number of sample timber areas, near to, farther removed, and remote from the sources of the fumes, were placed under observation. Approximately 7000 white pine trees in the vigorous age class of 50 to 90 years had been examined annually by 1954. Foliage on the white pine trees located less than 25 miles northeast of Sudbury showed more extensive injuries every year than foliage on trees located at greater distances from the smelters. Studies of diameter increment showed that there was a gradual decline in the annual growth of white pine in the areas near to the smelters, whereas a constant pattern was maintained in areas located farther from the sources of smoke. Further, in the areas close to the smelters, the volume of white pine lost through excessive tree mortality of all crown class sizes exceeded the volume added by the surviving trees. However, at distances beyond 25 to 30 miles northeast of Sudbury in the direction of the prevailing wind the condition of white pine improved remarkably. It is indicated that the combination of concentration frequency, and duration of atmospheric sulfur dioxide visitations has here declined to a threshold value for the inhibition of growth of white pine. 25 references, 25 figures, 23 tables.

Physico-mechanical properties of high performance concrete using different aggregates in presence of silica fume

Directory of Open Access Journals (Sweden)

Salah A. Abo-El-Enein

2014-04-01

Full Text Available Heavy weight high performance concrete (HPC can be used when particular properties, such as high strength and good radiation shielding are required. Such concrete, using ilmenite and hematite coarse aggregates can significantly have higher specific gravities than those of concrete made with dolomite and air-cooled slag aggregates. Four different concrete mixes with the same cement content and different w/c ratios were designed using normal dolomite aggregate, air-cooled slag by-product and two different types of iron ore aggregates. High performance concrete (grade-M60 can be achieved using superplasticizer to reduce the water/cement ratio; the effect of SF on the performance of concrete was studied by addition of 10% silica fume to the total cement content. The physico-mechanical properties of coarse aggregates and hardened concrete were studied. The results show that, Ilmenite coarse aggregate gives higher physical and mechanical properties than the other aggregates. Also, addition of 10% silica fume developed a stronger and a denser interfacial transition zone (ITZ between concrete particles and the cement matrix. Crushed air-cooled slag can be used to produce a high-strength concrete with better mechanical properties than corresponding concrete made with crushed hematite and ilmenite. Heavy density concrete made with fine aggregates of ilmenite and air-cooled slag are expected to be suitable as shielding materials to attenuate gamma rays.

Investigation of Fumed Silica/Aqueous NaCl Superdielectric Material

Directory of Open Access Journals (Sweden)

Natalie Jenkins

2016-02-01

Full Text Available A constant current charge/discharge protocol which showed fumed silica filled to the point of incipient wetness with aqueous NaCl solution to have dielectric constants >108 over the full range of dielectric thicknesses of 0.38–3.9 mm and discharge times of 0.25–>100 s was studied, making this material another example of a superdielectric. The dielectric constant was impacted by both frequency and thickness. For time to discharge greater than 10 s the dielectric constant for all thicknesses needed to be fairly constant, always >109, although trending higher with increasing thickness. At shorter discharge times the dielectric constant consistently decreased, with decreasing time to discharge. Hence, it is reasonable to suggest that for time to discharge >10 s the dielectric constant at all thicknesses will be greater than 109. This in turn implies an energy density for a 5 micron thick dielectric layer in the order of 350 J/cm3 for discharge times greater than 10 s.

Investigation of Fumed Silica/Aqueous NaCl Superdielectric Material.

Science.gov (United States)

Jenkins, Natalie; Petty, Clayton; Phillips, Jonathan

2016-02-20

A constant current charge/discharge protocol which showed fumed silica filled to the point of incipient wetness with aqueous NaCl solution to have dielectric constants >10⁸ over the full range of dielectric thicknesses of 0.38-3.9 mm and discharge times of 0.25->100 s was studied, making this material another example of a superdielectric. The dielectric constant was impacted by both frequency and thickness. For time to discharge greater than 10 s the dielectric constant for all thicknesses needed to be fairly constant, always >10⁸, although trending higher with increasing thickness. At shorter discharge times the dielectric constant consistently decreased, with decreasing time to discharge. Hence, it is reasonable to suggest that for time to discharge >10 s the dielectric constant at all thicknesses will be greater than 10⁸. This in turn implies an energy density for a 5 micron thick dielectric layer in the order of 350 J/cm³ for discharge times greater than 10 s.

[Association of cooking oil fumes exposure and oxidative DNA damage among occupational exposed populations].

Science.gov (United States)

Ke, Yue-bin; Xu, Xin-yun; Yuan, Jian-hui; Fang, Shi-song; Liu, Yi-min; Wu, Tang-chun

2010-08-01

Previous investigations indicate that cooks are exposed to polycyclic aromatic hydrocarbons (PAH) from cooking oil fumes (COF). However, Emission of PAH and their carcinogenic potencies from cooking oil fumes sources have not been investigated among cooks. To investigate the urinary excretion of a marker for oxidative DNA damage, 8-hydroxydeoxyguanosine (8-OHdG), in different groups of cooks and different exposure groups, and to study the association between 8-OHdG and 1-hydroxypyrene (1-OHP), a biological marker for PAH exposure. Urine samples were collected from different groups of cooks (n = 86) and from unexposed controls (n = 36), all are male with similar age and smoking habits. The health status, occupational history, smoking, and alcohol consumption 24 hours prior to sampling was estimated from questionnaires. The urinary samples were frozen for later analyses of 8-OHdG and 1-OHP by high performance liquid chromatography. Excretion in urine of 8-OHdG were similar for controls (mean 1.2 µmol/mol creatinine, n = 36), and for those who had been in the kitchen room with exhaust hood operation (mean 1.5 µmol/mol creatinine, n = 45). COF exposed cooks without exhaust hood operation had increased excretion of 8-OHdG (mean 2.3 µmol/mol creatinine, n = 18). The difference between this group and the unexposed controls was significant. The urinary levels of ln 1-OHP and ln 8-OHdG were still significantly correlated in a multiple regression analysis. Results indicate that exposure to PAH or possibly other compounds in COF may cause oxidative DNA damage.

New Zealanders working non-standard hours also have greater exposure to other workplace hazards.

Science.gov (United States)

Jay, Sarah M; Gander, Philippa H; Eng, Amanda; Cheng, Soo; Douwes, Jeroen; Ellison-Loschmann, Lis; McLean, Dave; Pearce, Neil; 'tMannetje, Andrea

2017-01-01

Exposure to workplace hazards, such as dust, solvents, and fumes, has the potential to adversely affect the health of people. However, the effects of workplace hazards on health may differ when exposure occurs at different times in the circadian cycle, and among people who work longer hours or who do not obtain adequate sleep. The aim of the present study was to document exposures to workplace hazards across a national sample of New Zealanders, comparing people who work a standard 08:00 -17:00 h Monday-to-Friday working week (Std hours) and those who do not (N-Std hours). New Zealanders (n = 10 000) aged 20-64 yrs were randomly selected from the Electoral Roll to take part in a nationwide survey of workplace exposures. Telephone interviews were conducted between 2004 and 2006, using a six-part questionnaire addressing demographics, detailed information on the current or most recent job (including exposures to a range of workplace hazards), sleep, sleepiness, and health status. N-Std hours were categorised on the basis of: being required to start work prior to 07:00 h or finish work after 21:00 h and/or; having a regular on-call commitment (at least once per week) and/or; working rotating shifts and/or; working night shift(s) in the last month. The response rate was 37% (n = 3003), with 22.2% of participants (n = 656) categorised as working N-Std hours. Industry sectors with the highest numbers of participants working N-Std hours were manufacturing, health and community services, and agriculture, fishing, and forestry. Response rate was 37% (n = 3003) with 22.2% (n = 656) categorised as working N-Std hours. Participants working N-Std hours were more likely to be exposed to all identified hazards, including multiple hazards (OR = 2.45, 95% CI = 2.01-3.0) compared to those working Std hours. Participants working N-Std hours were also more likely to report 'never/rarely' getting enough sleep (OR = 1.38, 95% CI = 1.15-1.65), 'never/rarely' waking refreshed (OR = 1

Effects of nitrous fumes upon the lung

Energy Technology Data Exchange (ETDEWEB)

Muhar, F; Raber, A

1974-01-01

After a thorough discussion of the accidental poisoning of 34 workers by large amounts of nitrous fumes in an Austrian chemical plant producing artificial fertilizer and its effects on the lung along with therapeutical measures taken, the chronic effects of long-term exposure to nitrous gases are reviewed. Nitrous gases are a mixture of various oxidation states of nitrogen such as nitric oxide, nitrogen dioxide, N/sub 2/O/sub 4/, and nitric anhydride plus vapors of nitrous and nitric acid. The individual components of the gas mixture change in dependence on the ambient temperature and the humidity. A different mixture of nitrous gases develops, therefore, at welding operations, blasts, in the chemical industry, in the glass industry, at the production of fertilizer, in the exhausts of combustion engines, and in smoking of cigarettes. The irritations caused by nitrous gases on mucous tissue increase with rising relative humidity. The presence of NO ameliorates the toxic effect of NO/sub 2/. Oil mists protect against the effects of nitrous gases. The addition of sulfur dioxide is supposed to reduce the toxicity of nitrous gases, provided the SO/sub 2/ concentration is considerably higher than the concentration of nitrous gases. Exposure of rats and mice to concentrations of less than 1 ppm nitrous gases caused structural changes in the lung similar to pulmonary edema in humans.

The Use of Wetting Agents/Fume Suppressants for Minimizing the Atmospheric Emissions from Hard Chromium Electroplating Baths

Science.gov (United States)

2004-03-01

PFOA), perfluorooctane sulphonic acid (PFOSA) and clofibric acid . Biochim Biophys Acta 1128: 65-72 Kannan K, Koistinen J, Beckmen K, Evans T...mg/dscm (6.6 x 10-6 gr/dscf) Decorative Chromium Plating Baths Using Chromic Acid All new and existing baths 0.01 mg/dscm (4.4 x 10-6 gr/dscf...surface of the baths, causing the production of chromic acid mist. “Surface active” fume suppressants (also called surfactants) are added directly

The Use of Wetting Agents/Fume Supressants for Minimizing the Atmospheric Emissions from Hard Chromium Electroplating Baths

Science.gov (United States)

2003-08-01

Accreditation (A2LA) for compliance with ISO 9001, Quality Systems - Model for Quality Assurance in Design, Development, Production, Installation and Servicing...All samples handling and testing at Patuxent River laboratory is ISO 9001 compliant. Appendix D, Table 1, 2, and 4 outline the test methods...HCF 0.1 4 3 8583 ± 288 8257/8909 8155/9012 1 TEST (N = 44090 CYCLES) TREATED AS AN OUTLIER. EXTRA HARD CHROME WITH FUME SUPPRESSANT HCF -1 4 4

Toenail as Non-invasive Biomarker in Metal Toxicity Measurement of Welding Fumes Exposure - A Review

Science.gov (United States)

Bakri, S. F. Z.; Hariri, A.; Ma'arop, N. F.; Hussin, N. S. A. W.

2017-01-01

Workers are exposed to a variety of heavy metal pollutants that are released into the environment as a consequence of workplace activities. This chemical pollutants are incorporated into the human by varies of routes entry and can then be stored and distributed in different tissues, consequently have a potential to lead an adverse health effects and/or diseases. As to minimize the impact, a control measures should be taken to avoid these effects and human biological marker is a very effective tool in the assessment of occupational exposure and potential related risk as the results is normally accurate and reproducible. Toenail is the ideal matrix for most common heavy metals due to its reliability and practicality compared to other biological samples as well as it is a non-invasive and this appears as a huge advantage of toenail as a biomarker. This paper reviews studies that measure the heavy metals concentration in toenail as non-invasive matrix which later may adapt in the investigation of metal fume emitted from welding process. The development of new methodology and modern analytical techniques has allowed the use of toenail as non-invasive approach. The presence of a heavy metal in this matrix reflects an exposure but the correlations between heavy metal levels in the toenail must be established to ensure that these levels are related to the total body burden. These findings suggest that further studies on interactions of these heavy metals in metal fumes utilizing toenail biomarker endpoints are highly warranted especially among welders.

Influence of organic solvents on interfacial water at surfaces of silica gel and partially silylated fumed silica

International Nuclear Information System (INIS)

Turov, V.V.; Gun'ko, V.M.; Tsapko, M.D.; Bogatyrev, V.M.; Skubiszewska-Zieba, J.; Leboda, R.; Ryczkowski, J.

2004-01-01

The effects of organic solvents (dimethylsulfoxide-d 6 (DMSO-d 6 ), chloroform-d, acetone-d 6 , and acetonitrile-d 3 ) on the properties of interfacial water at surfaces of silica gel Si-40 and partially silylated fumed silica A-380 were studied by means of the 1 H NMR spectroscopy with freezing-out of adsorbed water at 180 1 H NMR investigations were also analysed on the basis of the structural characteristics of silicas and quantum chemical calculations of the chemical shifts δ H and solvent effects. DMSO-d 6 and acetonitrile-d 3 are poorly miscible with water in silica gel pores in contrast to the bulk liquids. DMSO-d 6 and chloroform-d affect the structure of the interfacial water weaker than acetone-d 6 and acetonitrile-d 3 at amounts of liquids greater than the pore volume. Acetone-d 6 and acetonitrile-d 3 can displace water from pores under this condition. The chemical shift of protons in water adsorbed on silica gel is 3.5-6.5 ppm, which corresponds to the formation of two to four hydrogen bonds per molecule. Water adsorbed on partially silylated fumed silica has two 1 H NMR signals at 5 and 1.1-1.7 ppm related to different structures (droplets and small clusters) of the interfacial water

The inverse hazard law: blood pressure, sexual harassment, racial discrimination, workplace abuse and occupational exposures in US low-income black, white and Latino workers.

Science.gov (United States)

Krieger, Nancy; Chen, Jarvis T; Waterman, Pamela D; Hartman, Cathy; Stoddard, Anne M; Quinn, Margaret M; Sorensen, Glorian; Barbeau, Elizabeth M

2008-12-01

Research on societal determinants of health suggests the existence of an "inverse hazard law," which we define as: "The accumulation of health hazards tends to vary inversely with the power and resources of the populations affected." Yet, little empirical research has systematically investigated this topic, including in relation to workplace exposures. We accordingly designed the United for Health study (Greater Boston Area, Massachusetts, 2003-2004) to investigate the joint distribution and health implications of workplace occupational hazards (dust, fumes, chemical, noise, ergonomic strain) and social hazards (racial discrimination, sexual harassment, workplace abuse). Focusing on blood pressure as our health outcome, we found that among the 1202 low-income multi-racial/ethnic working class participants in our cohort - of whom 40% lived below the US poverty line - 79% reported exposure to at least one social hazard and 82% to at least one high-exposure occupational hazard. Only sexual harassment, the least common social hazard, was associated with elevated systolic blood pressure (SBP) among the women workers. By contrast, no statistically significant associations were detectable between the other additional highly prevalent social and occupational hazards and SBP; we did, however, find suggestive evidence of an association between SBP and response to unfair treatment, implying that in a context of high exposure, differential susceptibility to the exposure matters. These results interestingly contrast to our prior findings for this same cohort, in which we found associations between self-reported experiences of racial discrimination and two other health outcomes: psychological distress and cigarette smoking. Likely explanations for these contrasting findings include: (a) the differential etiologic periods and pathways involving somatic health, mental health, and health behaviors, and (b) the high prevalence of adverse exposures, limiting the ability to detect

Carbonation of ternary cementitious concrete systems containing fly ash and silica fume

Directory of Open Access Journals (Sweden)

Eehab Ahmed Badreldin Khalil

2015-04-01

Full Text Available Carbonation is quite a complex physical negative effect phenomenon on concrete especially in the ones containing ternary blends of Portland Cement, fly ash, and silica fume. Nine selected concrete mixtures were prepared with various water to cementitious materials’ ratios and various cementitious contents. The concrete mixtures were adapted in such a way to have the same workability and air content. The fresh concrete properties were kept near identical in slump, air content, and unit weight. The variation was in the hardened concrete mechanical properties of compression and tension strength. The carbonation phenomenon was studied for these mixes showing at which mixes of ternary cementitious content heavy carbonation attacks maybe produced. The main components of such mixes that do affect the carbonation process with time were presented.

Association between Chinese cooking oil fumes and sleep quality among a middle-aged Chinese population

International Nuclear Information System (INIS)

Wei, Fu; Nie, Guanghui; Zhou, Bo; Wang, Liang; Ma, Yifei; Peng, Suwan; Ou, Songfeng; Qin, Jian; Zhang, Li'e; Li, Shu; Zou, Ruosi; Zeng, Xiaoyun; Zhang, Zhiyong; Zou, Yunfeng

2017-01-01

Poor sleep quality is an important symptom of many medical or psychiatric disorders. However, the impact of cooking oil fumes (COFs) on sleep quality has not been studied. This population-based cross-sectional study was conducted to examine the association between COFs of Chinese household cooking and sleep quality. Individual sleep quality assessment was completed in 2197 participants with an average age of 37.52 years, through Pittsburgh Sleep Quality Index (PSQI). Information about their cooking practice were also collected by self-reported questionnaire. As an internal biomarker of COFs, urinary 1-hydroxypyrene (1-HOP) (n = 562) was further measured using high-performance liquid chromatography. Binary logistic regression models were performed to evaluate the association between exposure to COFs and individual sleep quality. We found that, subjective poor kitchen ventilation, preheating oil to smoking, and cooking for over 30 minutes were positively associated with overall poor sleep quality (global PSQI score >5) [odds ratio (OR) = 1.75, 95% confidence interval (CI) = 1.43–2.16; 1.25, (1.03–1.52); 1.42, (1.15–1.76), respectively]. After adjusting for potential confounders, subjective poor kitchen ventilation still tend to increase the risk of long sleep latency, sleep disturbances, and daytime dysfunction [OR = 1.37, 95% CI = 1.09–1.73; 1.91, (1.39–2.61); 1.54, (1.23–1.93), respectively]. Similar results were observed in participants who preheated oil to smoking [OR = 1.36, 95% CI = 1.08–1.72; 1.55, (1.14–2.14); 1.25, (1.02–1.55), respectively] and cooked for over 30 minutes [OR = 1.34, 95% CI = 1.05–1.72; 1.46, (1.03–2.06); 1.36, (1.08–1.72), respectively]. Furthermore, high urinary 1-HOP level was also positively associated with overall poor sleep quality (OR = 2.30, 95% CI = 1.31–4.05). The results indicated that exposure to COFs from Chinese household cooking may be a risk factor for poor sleep quality among

Influence upon the development of plants of zinc and lead, precipitated from factory fumes into the soil

Energy Technology Data Exchange (ETDEWEB)

Lundergardh, H

1927-01-01

The investigation reported here deals with soil from a field situated close to a roasting factory for zinc ore. From the fumes of the factory, zinc and lead have precipitated into the soil. From the field, 25 kg of soil were taken from each of 6 places symmetrically distributed over the field and used in pot cultures. The results of experiments show that even though the soil is enriched in lead and zinc, they occur in nearly insoluble combinations, and are physiologically ineffective.

Unknown plant de-construction hazard -- Toxic COS and CS2 gas from torch cutting of pipe

International Nuclear Information System (INIS)

Martin, H.L.; Nutt, A.W.; Myers, B.L.; Hightower, J.O.

1994-01-01

An employee exhibited signs of illness after apparently inhaling fumes generated from a pipe that had been cut with a cutting torch. Identification and quantification of the hazardous air emission for reduction of risk via the Department of Energy Class B Investigation are described in this case study. The old hydrogen sulfide gas flare pipe in the heavy water plant of the Savannah River Site has been abandoned with one end open to atmosphere for almost twenty years. The pipe was being removed and cut into sections for disposal during an asbestos abatement project. It contained ash like corrosion deposits that smolder after torch cutting. Investigation revealed that burning of carbon and sulfur in the oxygen deficient atmosphere in the ash generated carbonyl sulfide (COS) and carbon disulfide (CS 2 ) gas, which vented when the pipe was moved by the injured construction rigger. This is believed to be the first well documented exposure and response of a human to high concentration COS gas. Sulfur dioxide (SO 2 ) gas is also generated during the cutting. SO 2 is almost impossible to inhale and has apparently prevented a similar injury during the cutting. SO 2 is almost impossible to inhale and has apparently prevented a similar injury during the many years of US and Canadian heavy water plant de-construction experience. Immediate water quench of the smoldering ash after each cut has eliminated the hazard of residual COS and CS 2 gas. This previously unrecognized industrial hazard may be encountered by other chemical and petroleum industries during torch cutting of pipes that contain similar deposits of iron oxide, iron sulfate, sulfur and carbon

Development of UHPC Mixtures Utilizing Natural and Industrial Waste Materials as Partial Replacements of Silica Fume and Sand

OpenAIRE

Ahmad, Shamsad; Hakeem, Ibrahim; Maslehuddin, Mohammed

2014-01-01

In the exploratory study presented in this paper, an attempt was made to develop different mixtures of ultrahigh performance concrete (UHPC) using various locally available natural and industrial waste materials as partial replacements of silica fume and sand. Materials such as natural pozzolana (NP), fly ash (FA), limestone powder (LSP), cement kiln dust (CKD), and pulverized steel slag (PSS), all of which are abundantly available in Saudi Arabia at little or no cost, were employed in the de...

The effect of silica fume and metakaolin on glass-fibre reinforced concrete (GRC ageing

Directory of Open Access Journals (Sweden)

Enfedaque Díaz, A.

2010-12-01

Full Text Available The deterioration of the mechanical properties of glassfibre reinforced concrete (GRC over time rules out the use of this material in load-bearing structures. While one possible solution to this problem is the addition of pozzolans or metakaolin to the cement mortar, the amounts needed to ensure GRC integrity raise its price to non-competitive levels. Experimental research has been conducted to analyze whether the addition of small amounts of silica fume or metakaolin can prevent or mitigate the ageing issue. Unfortunately, the findings indicate that the addition of small proportions of metakaolin or silica fume to GRC are ineffective in improving its long-term performance.

Para el uso del mortero de cemento reforzado con fibras de vidrio (GRC en estructuras portantes se han de solucionar los problemas de reducción de las propiedades mecánicas que aparecen con el paso del tiempo. Estos problemas pueden ser solucionados mediante la adición de puzolanas o de metacaolín, a la pasta de mortero de cemento. Sin embargo, la cantidad de metacaolín que ha de ser añadida es elevada y el precio del GRC fabricado está fuera del mercado. Se ha realizado una campaña experimental que analiza si la adición de humo de sílice o de metacaolín en proporciones reducidas consigue evitar o paliar el problema del envejecimiento, que supone un freno al uso del GRC en elementos estructurales. Desgraciadamente, los resultados experimentales muestran que proporciones bajas de metacaolín o de humo de sílice no son efectivas para reducir el problema de pérdida de propiedades mecánicas.

In vitro dentin permeability after application of Gluma® desensitizer as aqueous solution or aqueous fumed silica dispersion

Directory of Open Access Journals (Sweden)

Hiroshi Ishihata

2011-04-01

Full Text Available OBJECTIVES: To assess and to compare the effects of Gluma® Desensitizer (GDL with an experimental glutaraldehyde and HEMA containing fumed silica dispersion (GDG on dentin permeability using a chemiluminous tracer penetration test. MATERIAL AND METHODS: Twenty disc-shaped dentin specimens were dissected from extracted human third molars. The dentin specimens were mounted in a split chamber device for determination of permeability under liquid pressure using a photochemical method. Ten specimens were randomly selected and allocated to the evaluation groups Gluma® Desensitizer as aqueous solution and glutaraldehyde/HEMA as fumed silica dispersion, respectively. Dentin disc permeability was determined at two pressure levels after removal of smear with EDTA, after albumin soaking, and after application of the desensitizing agents. Two desensitizer-treated and rinsed specimens of each group were examined by scanning electron microscopy (SEM for surface remnants. RESULTS: Comparatively large standard deviations of the mean EDTA reference and albumin soaked samples permeability values refected the differences of the dentin substrates. The mean chemiluminescence values of specimen treated with GDL and GDG, respectively, were signifcantly reduced after topical application of the desensitizing agents on albumin-soaked dentin. The effects of GDL and GDG on permeability were not signifcantly different. Treated specimens showed no surface remnants after rinsing. CONCLUSIONS: The experimental desensitizer gel formulation reduced dentin permeability as effectively as the original Gluma® Desensitizer solution.

Effect of Fly Ash and Silica Fume on the Mechanical Properties of Cement Paste at Different Stages of Hydration

Science.gov (United States)

2015-08-10

All materials were placed in a clean, labeled stainless steel mixing bowl and weighed to the nearest ten thousandth of a pound. The cement and fly...on the Mechanical Properties of Cement Paste at Different Stages of Hydration This thesis investigates the effect of fly ash and silica fume on... cement paste hydration. Percentages of each additive will replace the cement by volume to be studied at five ages. These percentages will be compared

Field comparison of three inhalable samplers (IOM, PGP-GSP 3.5 and Button) for welding fumes.

Science.gov (United States)

Zugasti, Agurtzane; Montes, Natividad; Rojo, José M; Quintana, M José

2012-02-01

Inhalable sampler efficiency depends on the aerodynamic size of the airborne particles to be sampled and the wind speed. The aim of this study was to compare the behaviour of three personal inhalable samplers for welding fumes generated by Manual Metal Arc (MMA) and Metal Active Gas (MAG) processes. The selected samplers were the ones available in Spain when the study began: IOM, PGP-GSP 3.5 (GSP) and Button. Sampling was carried out in a welding training center that provided a homogeneous workplace environment. The static sampling assembly used allowed the placement of 12 samplers and 2 cascade impactors simultaneously. 183 samples were collected throughout 2009 and 2010. The range of welding fumes' mass concentrations was from 2 mg m(-3) to 5 mg m(-3). The pooled variation coefficients for the three inhalable samplers were less than or equal to 3.0%. Welding particle size distribution was characterized by a bimodal log-normal distribution, with MMADs of 0.7 μm and 8.2 μm. For these welding aerosols, the Button and the GSP samplers showed a similar performance (P = 0.598). The mean mass concentration ratio was 1.00 ± 0.01. The IOM sampler showed a different performance (P IOM and 0.92 ± 0.02 for GSP/IOM. This information is useful to consider the measurements accomplished by the IOM, GSP or Button samplers together, in order to assess the exposure at workplaces over time or to study exposure levels in a specific industrial activity, as welding operations.

Influence of organic solvents on interfacial water at surfaces of silica gel and partially silylated fumed silica

Energy Technology Data Exchange (ETDEWEB)

Turov, V.V.; Gun' ko, V.M.; Tsapko, M.D.; Bogatyrev, V.M.; Skubiszewska-Zieba, J.; Leboda, R.; Ryczkowski, J

2004-05-15

The effects of organic solvents (dimethylsulfoxide-d{sub 6} (DMSO-d{sub 6}), chloroform-d, acetone-d{sub 6}, and acetonitrile-d{sub 3}) on the properties of interfacial water at surfaces of silica gel Si-40 and partially silylated fumed silica A-380 were studied by means of the {sup 1}H NMR spectroscopy with freezing-out of adsorbed water at 180fumed silica has two {sup 1}H NMR signals at 5 and 1.1-1.7 ppm related to different structures (droplets and small clusters) of the interfacial water.

Chronic exposure to iron oxide, chromium oxide, and nickel oxide fumes of metal dressers in a steelworks

Science.gov (United States)

Jones, J. Graham; Warner, C. G.

1972-01-01

Graham Jones, J., and Warner, C. G. (1972).Brit. J. industr. Med.,29, 169-177. Chronic exposure to iron oxide, chromium oxide, and nickel oxide fumes of metal dressers in a steelworks. Occupational and medical histories, smoking habits, respiratory symptoms, chest radiographs, and ventilatory capacities were studied in 14 steelworkers employed as deseamers of steel ingots for periods of up to 16 years. The men were exposed for approximately five hours of each working shift to fume concentrations ranging from 1·3 to 294·1 mg/m3 made up mainly of iron oxide with varying proportions of chromium oxide and nickel oxide. Four of the men, with 14 to 16 years' exposure, showed radiological evidence of pneumoconiosis classified as ILO categories 2 or 3. Of these, two had pulmonary function within the normal range and two had measurable loss of function, moderate in one case and mild in the other. Many observers would diagnose these cases as siderosis but the authors consider that this term should be reserved for cases exposed to pure iron compounds. The correct diagnosis is mixed-dust pneumoconiosis and the loss of pulmonary function is caused by the effects of the mixture of metallic oxides. It is probable that inhalation of pure iron oxide does not cause fibrotic pulmonary changes, whereas the inhalation of iron oxide plus certain other substances obviously does. Images PMID:5021996

Exposure to diesel exhaust fumes in the context of exposure to ultrafine particles

Directory of Open Access Journals (Sweden)

Stella Bujak-Pietrek

2016-08-01

Full Text Available Objectives: Diesel exhaust fumes emission is a significant source of ultrafine particles, the size of which is expressed in nanometers. People occupationally exposed to diesel exhaust particles include mainly workers servicing vehicles with engines of this type. This article presents the analysis of measurements of ultrafine particle concentrations occurring in the bus depot premises during the work connected with everyday technical servicing of buses. Material and Methods: The measurements were carried out in the everyday servicing (ES room of the bus depot before, during and after the work connected with bus servicing. Determinations included: particle concentrations in terms of particle number and particle surface area, and mass concentrations of aerosol. Results: Mean value of number concentration of 10- to 1000-nm particles increased almost 20-fold, from 7600 particles/cm3 before starting bus servicing procedures to 130 000 particles/cm3 during the bus servicing procedures in the room. During the procedures, the mean surface area concentration of particles potentially deposited in the alveolar (A region was almost 3 times higher than that of the particles depositing in the tracheo-bronchial (TB region: 356.46 μm2/cm3 vs. 95.97 μm2/cm3, respectively. The mass concentration of the fraction of particulate matter with aerodynamic diameter 0.02–1 μm (PM1 increased 5-fold during the analyzed procedures and was 0.042 mg/m3 before, and 0.298 mg/m3 while the procedures continued. Conclusions: At the time when bus servicing procedures continued in the ES room, a very high increase in all parameters of the analyzed particles was observed. The diesel exhaust particles exhibit a very high degree of fragmentation and, while their number is very high and their surface area is very large, their mass concentration is relatively low. The above findings confirm that ultrafine particles found in diesel exhaust fumes may be harmful to the health of the

Ultrasmall transistor-based light sources

DEFF Research Database (Denmark)

With Jensen, Per Baunegaard; Tavares, Luciana; Kjelstrup-Hansen, Jakob

Dette projekt fokuserer på at udvikle transistor baserede nanofiber lyskilder med det overordnede mål at udvikle effektive og nano skalerede flerfarvede lyskilder integreret on-chip.......Dette projekt fokuserer på at udvikle transistor baserede nanofiber lyskilder med det overordnede mål at udvikle effektive og nano skalerede flerfarvede lyskilder integreret on-chip....

Cordierite-supported metal oxide for non-methane hydrocarbon oxidation in cooking oil fumes.

Science.gov (United States)

Huang, Yonghai; Yi, Honghong; Tang, Xiaolong; Zhao, Shunzheng; Gao, Fengyu; Wang, Jiangen; Yang, Zhongyu

2018-05-21

Cooking emission is an important reason for the air quality deterioration in the metropolitan area in China. Transition metal oxide and different loading of manganese oxide supported on cordierite were prepared by incipient wetness impregnation method and were used for non-methane hydrocarbon (NMHC) oxidation in cooking oil fumes (COFs). The effects of different calcination temperature and different Mn content were also studied. The SEM photographs and CO 2 temperature-programmed desorption revealed 5 wt% Mn/cordierite had the best pore structure and the largest number of the weak and moderate basic sites so it showed the best performance for NMHC oxidation. XRD analysis exhibited 5 wt% Mn/cordierite had the best dispersion of active phase and the active phase was MnO 2 when the calcination temperature was 400℃ which were good for the catalytic oxidation of NMHC.

Fume emissions from a low-cost 3-D printer with various filaments.

Science.gov (United States)

Floyd, Evan L; Wang, Jun; Regens, James L

2017-07-01

3-D printing is an additive manufacturing process involving the injection of melted thermoplastic polymers, which are then laid down in layers to achieve a pre-designed shape. The heated deposition process raises concerns of potential aerosol and volatile organic compounds (VOC) emission and exposure. The decreasing cost of desktop 3-D printers has made the use of 3-D printers more acceptable in non-industrial workplaces lacking sufficient ventilation. Meanwhile, little is known about the characteristics of 3-D printing fume emission. The objective of this study was to characterize aerosols and VOC emissions generated from various filaments used with a low-cost 3-D printer in an environmental testing chamber. A pre-designed object was printed in 1.25 hours using eight types of filaments. A scanning mobility particle sizer and an aerodynamic particle sizer were employed to measure the particle size distribution in sub-half-micron fraction (printers due to high respirablity, especially if used in settings without proper guidance and engineering control.

Strategisk ledelse af evalueringskulturen

Directory of Open Access Journals (Sweden)

Gitte Orlowitz

2016-02-01

Full Text Available Hvis evaluering skal anvendes til at udvikle uddannelser, er en af ledelsen vigtigste opgaver at udvikle en strategi for udvikling af evalueringskulturen – herunder strategier for udvikling af kommunikation og evalueringskapacitet. Den strategiske ledelse kan i den sammenhæng anvendes til at håndtere de ofte modsatte krav, som eksterne og interne interessenter stiller til evaluering.

Transportation of Hazardous Materials Emergency Preparedness Hazards Assessment

Energy Technology Data Exchange (ETDEWEB)

Blanchard, A.

2000-02-28

This report documents the Emergency Preparedness Hazards Assessment (EPHA) for the Transportation of Hazardous Materials (THM) at the Department of Energy (DOE) Savannah River Site (SRS). This hazards assessment is intended to identify and analyze those transportation hazards significant enough to warrant consideration in the SRS Emergency Management Program.

Transportation of Hazardous Materials Emergency Preparedness Hazards Assessment

International Nuclear Information System (INIS)

Blanchard, A.

2000-01-01

This report documents the Emergency Preparedness Hazards Assessment (EPHA) for the Transportation of Hazardous Materials (THM) at the Department of Energy (DOE) Savannah River Site (SRS). This hazards assessment is intended to identify and analyze those transportation hazards significant enough to warrant consideration in the SRS Emergency Management Program

Transportation of hazardous materials emergency preparedness hazards assessment

International Nuclear Information System (INIS)

Blanchard, A.

2000-01-01

This report documents the Emergency Preparedness Hazards Assessment (EPHA) for the Transportation of Hazardous Materials (THM) at the Department of Energy (DOE) Savannah River Site (SRS). This hazards assessment is intended to identify and analyze those transportation hazards significant enough to warrant consideration in the SRS Emergency Management Program

Hazard function theory for nonstationary natural hazards

Science.gov (United States)

Read, L.; Vogel, R. M.

2015-12-01

Studies from the natural hazards literature indicate that many natural processes, including wind speeds, landslides, wildfires, precipitation, streamflow and earthquakes, show evidence of nonstationary behavior such as trends in magnitudes through time. Traditional probabilistic analysis of natural hazards based on partial duration series (PDS) generally assumes stationarity in the magnitudes and arrivals of events, i.e. that the probability of exceedance is constant through time. Given evidence of trends and the consequent expected growth in devastating impacts from natural hazards across the world, new methods are needed to characterize their probabilistic behavior. The field of hazard function analysis (HFA) is ideally suited to this problem because its primary goal is to describe changes in the exceedance probability of an event over time. HFA is widely used in medicine, manufacturing, actuarial statistics, reliability engineering, economics, and elsewhere. HFA provides a rich theory to relate the natural hazard event series (x) with its failure time series (t), enabling computation of corresponding average return periods and reliabilities associated with nonstationary event series. This work investigates the suitability of HFA to characterize nonstationary natural hazards whose PDS magnitudes are assumed to follow the widely applied Poisson-GP model. We derive a 2-parameter Generalized Pareto hazard model and demonstrate how metrics such as reliability and average return period are impacted by nonstationarity and discuss the implications for planning and design. Our theoretical analysis linking hazard event series x, with corresponding failure time series t, should have application to a wide class of natural hazards.

Hazard function theory for nonstationary natural hazards

Science.gov (United States)

Read, Laura K.; Vogel, Richard M.

2016-04-01

Impact from natural hazards is a shared global problem that causes tremendous loss of life and property, economic cost, and damage to the environment. Increasingly, many natural processes show evidence of nonstationary behavior including wind speeds, landslides, wildfires, precipitation, streamflow, sea levels, and earthquakes. Traditional probabilistic analysis of natural hazards based on peaks over threshold (POT) generally assumes stationarity in the magnitudes and arrivals of events, i.e., that the probability of exceedance of some critical event is constant through time. Given increasing evidence of trends in natural hazards, new methods are needed to characterize their probabilistic behavior. The well-developed field of hazard function analysis (HFA) is ideally suited to this problem because its primary goal is to describe changes in the exceedance probability of an event over time. HFA is widely used in medicine, manufacturing, actuarial statistics, reliability engineering, economics, and elsewhere. HFA provides a rich theory to relate the natural hazard event series (X) with its failure time series (T), enabling computation of corresponding average return periods, risk, and reliabilities associated with nonstationary event series. This work investigates the suitability of HFA to characterize nonstationary natural hazards whose POT magnitudes are assumed to follow the widely applied generalized Pareto model. We derive the hazard function for this case and demonstrate how metrics such as reliability and average return period are impacted by nonstationarity and discuss the implications for planning and design. Our theoretical analysis linking hazard random variable X with corresponding failure time series T should have application to a wide class of natural hazards with opportunities for future extensions.

Hazards assessment for the Hazardous Waste Storage Facility

International Nuclear Information System (INIS)

Knudsen, J.K.; Calley, M.B.

1994-04-01

This report documents the hazards assessment for the Hazardous Waste Storage Facility (HWSF) located at the Idaho National Engineering Laboratory. The hazards assessment was performed to ensure that this facility complies with DOE and company requirements pertaining to emergency planning and preparedness for operational emergencies. The hazards assessment identifies and analyzes hazards that are significant enough to warrant consideration in a facility's operational emergency management program. The area surrounding HWSF, the buildings and structures at HWSF, and the processes used at HWSF are described in this report. All nonradiological hazardous materials at the HWSF were identified (radiological hazardous materials are not stored at HWSF) and screened against threshold quantities according to DOE Order 5500.3A guidance. Two of the identified hazardous materials exceeded their specified threshold quantity. This report discusses the potential release scenarios and consequences associated with an accidental release for each of the two identified hazardous materials, lead and mercury. Emergency considerations, such as emergency planning zones, emergency classes, protective actions, and emergency action levels, are also discussed based on the analysis of potential consequences. Evaluation of the potential consequences indicated that the highest emergency class for operational emergencies at the HWSF would be a Site Area Emergency

Kvalitetscirkler – at arbejde med kvalitet uden at gå i stå

DEFF Research Database (Denmark)

Pedersen, Ulla

2001-01-01

Artiklen omhandler en metode, kvalitetscirkler, til kvalitetssikring og -udvikling. Metoden er udsprunget fra Demings teori og anvendes til bottom-up udvikling. Den er afprøvet i pilotprojekt i ergoterapien på Sønderborg Sygehus med succes.......Artiklen omhandler en metode, kvalitetscirkler, til kvalitetssikring og -udvikling. Metoden er udsprunget fra Demings teori og anvendes til bottom-up udvikling. Den er afprøvet i pilotprojekt i ergoterapien på Sønderborg Sygehus med succes....

Hazard interactions and interaction networks (cascades) within multi-hazard methodologies

Science.gov (United States)

Gill, Joel C.; Malamud, Bruce D.

2016-08-01

This paper combines research and commentary to reinforce the importance of integrating hazard interactions and interaction networks (cascades) into multi-hazard methodologies. We present a synthesis of the differences between multi-layer single-hazard approaches and multi-hazard approaches that integrate such interactions. This synthesis suggests that ignoring interactions between important environmental and anthropogenic processes could distort management priorities, increase vulnerability to other spatially relevant hazards or underestimate disaster risk. In this paper we proceed to present an enhanced multi-hazard framework through the following steps: (i) description and definition of three groups (natural hazards, anthropogenic processes and technological hazards/disasters) as relevant components of a multi-hazard environment, (ii) outlining of three types of interaction relationship (triggering, increased probability, and catalysis/impedance), and (iii) assessment of the importance of networks of interactions (cascades) through case study examples (based on the literature, field observations and semi-structured interviews). We further propose two visualisation frameworks to represent these networks of interactions: hazard interaction matrices and hazard/process flow diagrams. Our approach reinforces the importance of integrating interactions between different aspects of the Earth system, together with human activity, into enhanced multi-hazard methodologies. Multi-hazard approaches support the holistic assessment of hazard potential and consequently disaster risk. We conclude by describing three ways by which understanding networks of interactions contributes to the theoretical and practical understanding of hazards, disaster risk reduction and Earth system management. Understanding interactions and interaction networks helps us to better (i) model the observed reality of disaster events, (ii) constrain potential changes in physical and social vulnerability

Possible actions for the minimization of the environmental impact of the iron ore sintering fumes

International Nuclear Information System (INIS)

Garcia-Carcedo, F.; Ayala, N.; Isidro, A.; Moro, A.; Cornejo, N.; Ferreira, S.; Hernandez, A.; Cobo, A.; Alaiz, E.; Garcia, J. R.

2004-01-01

In sintering plants, gaseous emissions are generated which must comply with increasingly demanding environmental regulations. In the sintering process, about 40 kg of coke and 1,700 Nm''3 of air are used per ton of useful sinter. Sintering fumes have a gaseous phase formed mainly of N 2 , O 2 , CO 2 , H 2 O and CO and the minor components SO . SO 3 , NO and NO 2 . Other minor components include unburned organic products and CLH, and minimal proportions of other high impact compounds such as dioxins and furans are also present. Chlorides and heavy metals are present in the solid fraction. This paper reviews the situation of each emission in relation with the applicable regulations, and the possible means of reducing these emissions. (Author) 12 refs

Adjustable rheology of fumed silica dispersion in urethane prepolymers: Composition-dependent sol and gel behaviors and energy-mediated shear responses

Energy Technology Data Exchange (ETDEWEB)

Zheng, Zhong, E-mail: 11329038@zju.edu.cn; Song, Yihu, E-mail: s-yh0411@zju.edu.cn; Wang, Xiang, E-mail: 11229036@zju.edu.cn; Zheng, Qiang, E-mail: zhengqiang@zju.edu.cn [MOE Key Laboratory of Macromolecule Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027 (China)

2015-07-15

Variation of colloidal and interfacial interactions leads to a microstructural diversity in fumed silica dispersions exhibiting absolutely different sol- or gel-like rheological responses. In this study, fumed silicas with different surface areas (200–400 m{sup 2}/g) and surface characteristics (hydrophilic or hydrophobic) are dispersed into moisture-cured polyurethane. The microstructures investigated using transmission electron microscope are associated perfectly with three different rheological behaviors: (i) Sols with well-dispersed silica aggregates, (ii) weak gels with agglomerate-linked networks, and (iii) strong gels with concentrated networks of large agglomerates. Though sols and gels are well distinguished by shear thickening or sustained thinning response through steady shear flow test, it is interesting that the sols and weak gels exhibit a uniform modulus plateau-softening-hardening-softening response with increasing dynamic strain at frequency 10 rad s{sup −1} while the strong gels show a sustained softening beyond the linear regime. Furthermore, the onset of softening and hardening can be normalized: The two softening are isoenergetic at mechanical energies of 0.3 J m{sup −3} and 10 kJ m{sup −3}. On the other hand, the hardening is initiated by a critical strain of 60%. The mechanisms involved in the generation of the sol- and the gel-like dispersions and their structural evolutions during shear are thoroughly clarified in relation to the polyols, the characteristic and content of silica and the curing catalysts.

Stabilization / solidification of polluted marine dredged sediment of port en Bessin France, using hydraulic binders and silica fume

Science.gov (United States)

Silitonga, Ernesto

2017-09-01

A large amount of sediment is dredged in France every year. Due to the increase of the amount of marine dredged sediments, environmentally reuse of dredged sediment is urgently needed in France. The first objective of this study is to find an application for reuse of marine dredged sediments materials, as new material for road construction. Hence, serial tests need to be realized to identify if marine dredged sediment could be utilized for road construction. The second goal is to enhance the physical, mechanical and chemical characteristics of the mix, by incorporating binders and sediments, and revealed the identification of the mechanical characteristics measured on the mixes is compatible with their use as a base course material. The results show that the treatment by hydraulics binders could satisfy the needed mechanical characteristics. The present of Silica Fume is aimed to reduce the pollution level, especially the heavy metal content. However, the proportion of hydraulics binders and silica fume needed to meet prescribed specification is important, so the reuse of the marine dredged sediments of Port-en-Bessin, France in road construction, as an alternative material could be achieved. After the geotechnical study in laboratory results shown as expected than the study to identify the chemical characteristic realized. To evaluate the environmental impacts of the used material, leaching test is performed. The leaching test was performed to verify the predicted release of pollutants based on total dissolution. And for the final part, the test results show that the polluted marine dredged sediments could be safely used (in term of environmental impact) as a new material in road construction.

Pulmonary function abnormalities and airway irritation symptoms of metal fumes exposure on automobile spot welders.

Science.gov (United States)

Luo, Jiin-Chyuan John; Hsu, Kuang-Hung; Shen, Wu-Shiun

2006-06-01

Spot or resistance welding has been considered less hazardous than other types of welding. Automobile manufacturing is a major industry in Taiwan. Spot and arc welding are common processes in this industry. The respiratory effects on automobile spot welders exposed to metal fumes are investigated. The cohort consisted of 41 male auto-body spot welders, 76 male arc welders, 71 male office workers, and 59 assemblers without welding exposure. Inductivity Coupled Plasma Mass Spectrophotometer (ICP-MS) was applied to detect metals' (zinc, copper, nickel) levels in the post-shift urine samples. Demographic data, work history, smoking status, and respiratory tract irritation symptoms were gathered by a standard self-administered questionnaire. Pulmonary function tests were also performed. There were significantly higher values for average urine metals' (zinc, copper, nickel) levels in spot welders and arc welders than in the non-welding controls. There were 4 out of 23 (17.4%) abnormal forced vital capacity (FVC) among the high-exposed spot welders, 2 out of 18 (11.1%) among the low-exposed spot welders, and 6 out of 130 (4.6%) non-welding-exposed workers. There was a significant linear trend between spot welding exposure and the prevalence of restrictive airway abnormalities (P = 0.036) after adjusting for other factors. There were 9 out of 23 (39.1%) abnormal peak expiratory flow rate (PEFR) among high-exposed spot welders, 5 out of 18 (27.8%) among the low-exposed spot welders, and 28 out of 130 (21.5%) non-welding-exposed workers. There was a borderline significant linear trend between spot welding exposure and the prevalence of obstructive lung function abnormalities (P = 0.084) after adjusting for other factors. There was also a significant dose-response relationship of airway irritation symptoms (cough, phlegm, chronic bronchitis) among the spot welders. Arc welders with high exposure status also had a significant risk of obstructive lung abnormalities (PEFR

Temperature dependence of autogenous shrinkage of silica fume cement pastes with a very low water–binder ratio

Energy Technology Data Exchange (ETDEWEB)

Maruyama, I., E-mail: ippei@dali.nuac.nagoya-u.ac.jp [Graduate School of Environmental Studies, Nagoya University, ES Building, No. 539, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Teramoto, A. [Graduate School of Environmental Studies, Nagoya University, Faculty of Engineering, ES Building, No. 546, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

2013-08-15

Ultra-high-strength concrete with a large unit cement content undergoes considerable temperature increase inside members due to hydration heat, leading to a higher risk of internal cracking. Hence, the temperature dependence of autogenous shrinkage of cement pastes made with silica fume premixed cement with a water–binder ratio of 0.15 was studied extensively. Development of autogenous shrinkage showed different behaviors before and after the inflection point, and dependence on the temperature after mixing and subsequent temperature histories. The difference in autogenous shrinkage behavior poses problems for winter construction because autogenous shrinkage may increase with decrease in temperature after mixing before the inflection point and with increase in temperature inside concrete members with large cross sections.

Temperature dependence of autogenous shrinkage of silica fume cement pastes with a very low water–binder ratio

International Nuclear Information System (INIS)

Maruyama, I.; Teramoto, A.

2013-01-01

Ultra-high-strength concrete with a large unit cement content undergoes considerable temperature increase inside members due to hydration heat, leading to a higher risk of internal cracking. Hence, the temperature dependence of autogenous shrinkage of cement pastes made with silica fume premixed cement with a water–binder ratio of 0.15 was studied extensively. Development of autogenous shrinkage showed different behaviors before and after the inflection point, and dependence on the temperature after mixing and subsequent temperature histories. The difference in autogenous shrinkage behavior poses problems for winter construction because autogenous shrinkage may increase with decrease in temperature after mixing before the inflection point and with increase in temperature inside concrete members with large cross sections

Fumed silica nanoparticle mediated biomimicry for optimal cell-material interactions for artificial organ development.

Science.gov (United States)

de Mel, Achala; Ramesh, Bala; Scurr, David J; Alexander, Morgan R; Hamilton, George; Birchall, Martin; Seifalian, Alexander M

2014-03-01

Replacement of irreversibly damaged organs due to chronic disease, with suitable tissue engineered implants is now a familiar area of interest to clinicians and multidisciplinary scientists. Ideal tissue engineering approaches require scaffolds to be tailor made to mimic physiological environments of interest with specific surface topographical and biological properties for optimal cell-material interactions. This study demonstrates a single-step procedure for inducing biomimicry in a novel nanocomposite base material scaffold, to re-create the extracellular matrix, which is required for stem cell integration and differentiation to mature cells. Fumed silica nanoparticle mediated procedure of scaffold functionalization, can be potentially adapted with multiple bioactive molecules to induce cellular biomimicry, in the development human organs. The proposed nanocomposite materials already in patients for number of implants, including world first synthetic trachea, tear ducts and vascular bypass graft. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Bæredygtig modeindustri

DEFF Research Database (Denmark)

Skjold, Else; Kjær, Lykke Bloch; Gerner Nielsen, Elsebeth

2017-01-01

Indlæg om de udfordringer modeindustrien står over for i forhold til bæredygtighed - og de løsningsmodeller der udvikles gennem udvikling og implementering af ny viden på området i regi af Designskolen Kolding......Indlæg om de udfordringer modeindustrien står over for i forhold til bæredygtighed - og de løsningsmodeller der udvikles gennem udvikling og implementering af ny viden på området i regi af Designskolen Kolding...

Analysis of heat transfer and contaminant transport in fume hoods

International Nuclear Information System (INIS)

Pathanjali, C.; Rahman, M.M.

1996-01-01

The paper presents the analysis of three-dimensional flow patterns and the associated heat and mass transfer mechanisms in a fume hood enclosure. The flow enters the hood through the front window opening (positive x-direction) and leaves the cupboard through an opening on the top of the hood (positive z-direction). The flow was assumed to be fully turbulent. The flow pattern for different sash openings were studied. The flow pattern around an object located at the bottom of the hood was studied for different locations of the object. It was found that air entering the hood proceeds directly to the back wall, impinges it and turns upward toward the top wall and exits through the outlet. The flow finds its way around any object forming a recirculating region at its training surface. With an increase in the sash opening, the velocity becomes higher and the fluid traces the path to the outlet more quickly. The volume occupied by recirculating flow decreases with increase in sash opening. Both temperature and concentration were found to be maximum near the source and gradually decreased as the heated air or gaseous contaminant entrained with incoming air. The local concentration decreased with increase in sash opening area. The results will be very useful to design experiments with optimum sash opening providing adequate disposal of contaminants with minimum use of conditioned air inside the room

A Field Study on the Respiratory Deposition of the Nano-Sized Fraction of Mild and Stainless Steel Welding Fume Metals.

Science.gov (United States)

Cena, L G; Chisholm, W P; Keane, M J; Chen, B T

2015-01-01

A field study was conducted to estimate the amount of Cr, Mn, and Ni deposited in the respiratory system of 44 welders in two facilities. Each worker wore a nanoparticle respiratory deposition (NRD) sampler during gas metal arc welding (GMAW) of mild and stainless steel and flux-cored arc welding (FCAW) of mild steel. Several welders also wore side-by-side NRD samplers and closed-face filter cassettes for total particulate samples. The NRD sampler estimates the aerosol's nano-fraction deposited in the respiratory system. Mn concentrations for both welding processes ranged 2.8-199 μg/m3; Ni concentrations ranged 10-51 μg/m3; and Cr concentrations ranged 40-105 μg/m3. Cr(VI) concentrations ranged between 0.5-1.3 μg/m3. For the FCAW process the largest concentrations were reported for welders working in pairs. As a consequence this often resulted in workers being exposed to their own welding fumes and to those generated from the welding partner. Overall no correlation was found between air velocity and exposure (R2 = 0.002). The estimated percentage of the nano-fraction of Mn deposited in a mild-steel-welder's respiratory system ranged between 10 and 56%. For stainless steel welding, the NRD samplers collected 59% of the total Mn, 90% of the total Cr, and 64% of the total Ni. These results indicate that most of the Cr and more than half of the Ni and Mn in the fumes were in the fraction smaller than 300 nm.

Hazards and hazard combinations relevant for the safety of nuclear power plants

Science.gov (United States)

Decker, Kurt; Brinkman, Hans; Raimond, Emmanuel

2017-04-01

The potential of the contemporaneous impact of different, yet causally related, hazardous events and event cascades on nuclear power plants is a major contributor to the overall risk of nuclear installations. In the aftermath of the Fukushima accident, which was caused by a combination of severe ground shaking by an earthquake, an earthquake-triggered tsunami and the disruption of the plants from the electrical grid by a seismically induced landslide, hazard combinations and hazard cascades moved into the focus of nuclear safety research. We therefore developed an exhaustive list of external hazards and hazard combinations which pose potential threats to nuclear installations in the framework of the European project ASAMPSAE (Advanced Safety Assessment: Extended PSA). The project gathers 31 partners from Europe, North Amerika and Japan. The list comprises of exhaustive lists of natural hazards, external man-made hazards, and a cross-correlation matrix of these hazards. The hazard list is regarded comprehensive by including all types of hazards that were previously cited in documents by IAEA, the Western European Nuclear Regulators Association (WENRA), and others. 73 natural hazards and 24 man-made external hazards are included. Natural hazards are grouped into seismotectonic hazards, flooding and hydrological hazards, extreme values of meteorological phenomena, rare meteorological phenomena, biological hazards / infestation, geological hazards, and forest fire / wild fire. The list of external man-made hazards includes industry accidents, military accidents, transportation accidents, pipeline accidents and other man-made external events. The large number of different hazards results in the extremely large number of 5.151 theoretically possible hazard combinations (not considering hazard cascades). In principle all of these combinations are possible to occur by random coincidence except for 82 hazard combinations that - depending on the time scale - are mutually

Oxidative stress, telomere shortening, and DNA methylation in relation to low-to-moderate occupational exposure to welding fumes.

Science.gov (United States)

Li, Huiqi; Hedmer, Maria; Wojdacz, Tomasz; Hossain, Mohammad Bakhtiar; Lindh, Christian H; Tinnerberg, Håkan; Albin, Maria; Broberg, Karin

2015-10-01

Evidence suggests that exposure to welding fumes is a risk factor for lung cancer. We examined relationships between low-to-moderate occupational exposure to particles from welding fumes and cancer-related biomarkers for oxidative stress, changes in telomere length, and alterations in DNA methylation. We enrolled 101 welders and 127 controls (all currently nonsmoking men) from southern Sweden. We performed personal sampling of respirable dust and measured 8-oxodG concentrations in urine using a simplified liquid chromatography tandem mass spectrometry method. Telomere length in peripheral blood was measured by quantitative polymerase chain reaction. Methylation status of 10 tumor suppressor genes was determined by methylation-sensitive high-resolution melting analysis. All analyses were adjusted for age, body mass index, previous smoking, passive smoking, current residence, and wood burning stove/boiler at home. Welders were exposed to respirable dust at 1.2 mg/m(3) (standard deviation, 3.3 mg/m(3); range, 0.1-19.3), whereas control exposures did not exceed 0.1 mg/m(3) (P < 0.001). Welders and controls did not differ in 8-oxodG levels (β = 1.2, P = 0.17) or relative telomere length (β = -0.053, P = 0.083) in adjusted models. Welders showed higher probability of adenomatous polyposis coli (APC) methylation in the unadjusted model (odds ratio = 14, P = 0.014), but this was not significant in the fully adjusted model (P = 0.052). Every working year as a welder was associated with 0.0066 units shorter telomeres (95% confidence interval -0.013 to -0.00053, P = 0.033). Although there were no clear associations between concentrations of respirable dust and the biomarkers, there were modest signs of associations between oxidative stress, telomere alterations, DNA methylation, and occupational exposure to low-to-moderate levels of particles. © 2015 Wiley Periodicals, Inc.

Assessment of occupational exposure to manganese and other metals in welding fumes by portable X-ray fluorescence spectrometer.

Science.gov (United States)

Laohaudomchok, Wisanti; Cavallari, Jennifer M; Fang, Shona C; Lin, Xihong; Herrick, Robert F; Christiani, David C; Weisskopf, Marc G

2010-08-01

Elemental analysis of welding fume samples can be done using several laboratory-based techniques. However, portable measurement techniques could offer several advantages. In this study, we sought to determine whether the portable X-ray fluorescence spectrometer (XRF) is suitable for analysis of five metals (manganese, iron, zinc, copper, and chromium) on 37-mm polytetrafluoroethylene filters. Using this filter fitted on a cyclone in line with a personal pump, gravimetric samples were collected from a group of boilermakers exposed to welding fumes. We assessed the assumption of uniform deposition of these metals on the filters, and the relationships between measurement results of each metal obtained from traditional laboratory-based XRF and the portable XRF. For all five metals of interest, repeated measurements with the portable XRF at the same filter area showed good consistency (reliability ratios are equal or close to 1.0 for almost all metals). The portable XRF readings taken from three different areas of each filter were not significantly different (p-values = 0.77 to 0.98). This suggested that the metal rich PM(2.5) deposits uniformly on the samples collected using this gravimetric method. For comparison of the two XRFs, the results from the portable XRF were well correlated and highly predictive of those from the laboratory XRF. The Spearman correlation coefficients were from 0.325 for chromium, to 0.995 for manganese and 0.998 for iron. The mean differences as a percent of the mean laboratory XRF readings were also small (metals were moderately to strongly correlated with the total fine particle fraction on filters (Spearman rho = 0.41 for zinc to 0.97 for iron). Such strong correlations and comparable results suggested that the portable XRF could be used as an effective and reliable tool for exposure assessment in many studies.

Hazardous Waste

Science.gov (United States)

... chemicals can still harm human health and the environment. When you throw these substances away, they become hazardous waste. Some hazardous wastes come from products in our homes. Our garbage can include such hazardous wastes as old batteries, bug spray cans and paint thinner. U.S. residents ...

A study of mortars prepared with fly ash and silica fume for use in structures exposed to marine enviroments

Directory of Open Access Journals (Sweden)

Hernández, Y.

2003-12-01

Full Text Available The purpose of this study is to evaluate different mortar mixtures containing 5, 10 and 1 5% P/P silica fume and 5, 10, 12.5, 15 and 17.5% P/P fly ash to be used for repairing/constructing reinforced concrete structures exposed to marine environments. These were evaluated from the following standpoints: physical-chemical (capillary absorption and effective porosity; mechanical (compressive strength; electrochemical (lineal polarization, cyclic polarización and rapid chloride permeation; morphological (scanning electron microscopy. Results showed that 15 % silica fume mixture with no fly ash gave the best performance from both the physical-mechanical as well as the economic standpoint.

El presente trabajo tiene como finalidad evaluar diferentes mezclas de mortero con contenidos de 5, 10 y 15 % P/P de microsílica y contenidos de 5, 10, 12,5, 15 y 17,5 % P/P de ceniza volante para ser utilizadas en la reparación/construcción de estructuras de concreto armado expuestas a ambientes marinos. Se evaluaron desde el punto de vista físico-químico (absorción capilar y porosidad efectiva, mecánico (resistencia a la compresión, electroquímico (polarización lineal, polarización cíclica y permeabilidad rápida de cloruros y su morfología por medio de microscopía electrónica de barrido. Los resultados permitieron seleccionar la mezcla conteniendo 15 % de microsílica sin ceniza volante, tanto desde el punto de vista físico-mecánico y electroquímico como económico.

Hazard perception in traffic. [previously knows as: Hazard perception.

NARCIS (Netherlands)

2008-01-01

Hazard perception is an essential part of the driving task. There are clear indications that insufficient skills in perceiving hazards play an important role in the occurrence of crashes, especially those involving novice drivers. Proper hazard perception not only consists of scanning and perceiving

Identification of Potential Hazard using Hazard Identification and Risk Assessment

Science.gov (United States)

Sari, R. M.; Syahputri, K.; Rizkya, I.; Siregar, I.

2017-03-01

This research was conducted in the paper production’s company. These Paper products will be used as a cigarette paper. Along in the production’s process, Company provides the machines and equipment that operated by workers. During the operations, all workers may potentially injured. It known as a potential hazard. Hazard identification and risk assessment is one part of a safety and health program in the stage of risk management. This is very important as part of efforts to prevent occupational injuries and diseases resulting from work. This research is experiencing a problem that is not the identification of potential hazards and risks that would be faced by workers during the running production process. The purpose of this study was to identify the potential hazards by using hazard identification and risk assessment methods. Risk assessment is done using severity criteria and the probability of an accident. According to the research there are 23 potential hazard that occurs with varying severity and probability. Then made the determination Risk Assessment Code (RAC) for each potential hazard, and gained 3 extreme risks, 10 high risks, 6 medium risks and 3 low risks. We have successfully identified potential hazard using RAC.

75 FR 65067 - National Emission Standards for Hazardous Air Pollutant Emissions: Hard and Decorative Chromium...

Science.gov (United States)

2010-10-21

... Reform Act URE--Unit Risk Estimate VOC--Volatile Organic Compounds WAFS--Wetting Agent/Fume Suppressant...; Group I Polymers and Resins; Marine Tank Vessel Loading Operations; Pharmaceuticals Production; The... Decorative Chromium Electroplating and Chromium Anodizing Tanks; Group I Polymers and Resins; Marine Tank...

Opening of the first CO{sub 2} capture installation on the fumes of a coal power plant - european project Castor, Denmark; Inauguration de la premiere installation de captage du CO{sub 2} sur les fumees d'une centrale electrique au charbon - Projet europeen Castor, Danemark

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-03-15

The 15 March 2006, was launched the first industrial pilot of CO{sub 2} capture of the Castor project, coordinated by the IFP and financed by the european commission, on the site of the Esbjerg (Denmark) power plant. It is the first world installation allowing the CO{sub 2} capture on the fumes of a coal power plant. This document presents the pilot installation, discusses the european project Castor, the advantages of the CO{sub 2} capture and storage for a better use of the fossil energies, where and how capturing the CO{sub 2} and the Denmark energy context. (A.L.B.)

Pozzolanic Reactivity of Silica Fume and Ground Rice Husk Ash as Reactive Silica in a Cementitious System: A Comparative Study

Directory of Open Access Journals (Sweden)

Weiting Xu

2016-03-01

Full Text Available This study comparably assessed the pozzolanic effect of silica fume (SF and ground rice husk ash (RHA as supplementary cementing materials on the properties of blended cement pastes and concretes. A commonly commercial silica fume (SF and locally-produced rice husk ash (RHA samples with two finenesses (one with larger size than cement and the other with smaller size than cement were used in this study. Material properties of SF and RHA were experimentally characterized. Hydration and mechanical properties of cement pastes incorporating SF and RHA were determined by thermogravimetric analysis (TGA and compressive strength tests, respectively. Properties of concretes regarding workability, mechanical property, durability, and microstructure were evaluated. Results showed that, although the finely ground RHA used in this study possessed lower SiO2 content and higher particle size compared to SF, it exhibited comparable pozzolanic reactivity with SF due to the nano-scale pores on its each single particle, leading to a higher specific surface area. The optimal replacement levels of SF and RHA were 10% by weight of cement in pastes and concretes. Although addition of SF and RHA led to a significant reduction in slump for the fresh mixtures, inclusion of up to 30% of SF or 15% of ground RHA did not adversely affect the strength of concretes. At the same mix, incorporation of finely-ground RHA in cement composites provided comparable mechanical properties, hydration degree, and durability with SF blended cement composites, owing to the porous structure and high specific surface area of RHA particles. Microstructure morphology analysis of concretes explored by scanning electron microscopy (SEM further validated the strength and the durability test results.

Application of UV and X-Ray radiation for refreshing of old latent fingerprints in the cyanoacrylate fuming technique - preliminary study

International Nuclear Information System (INIS)

Radiceska, Pavlina; Ristova, Mimoza

2013-01-01

The work described below focuses on enhancement/refreshment of older latent fingerprints onto a non porous (glass) surface. The aging of the fingerprints is a major problem of the forensic science, because of the compound’s degradation under the influence of a variety of atmospheric parameters, in addition to the time factor. The humidification extent on the latent fingerprints appeared to be one of the critical factors for the deposition of the cyanoacrylate on the finger-marks, since the unsaturated bonds from lipid content from the latent fingerprints serve as active water condensation centers. In the present work we show results from the enhancement of aged latent fingerprint details by activation of the humidity condensation centers with exposition to UV or X-ray radiation prior to their developing into the cyanoacrylate fuming chamber. The aging of the latent fingerprints on glass surfaces with the time for given conditions was established. A term “critical day” was introduced as the day when the detectable details from the latent fingerprints dropped to one half of the initial number of details, recovered from identical fresh latent fingerprint. As the fingerprints were aged to the “critical day”, one third of the samples were exposed to a UV for 15 minutes, another third to 15 minutes of X-ray radiation and the last third was kept unexposed. All the samples were developed into a single cyanoacrylate fuming process. The results showed that in both UV and X-ray cases, a considerable enhancement/refreshment, in approximately 50% of the aged latent fingerprints, has been achieved with only a short term irradiation (15 minutes). (Author)

Working towards a clearer and more helpful hazard map: investigating the influence of hazard map design on hazard communication

Science.gov (United States)

Thompson, M. A.; Lindsay, J. M.; Gaillard, J.

2015-12-01

Globally, geological hazards are communicated using maps. In traditional hazard mapping practice, scientists analyse data about a hazard, and then display the results on a map for stakeholder and public use. However, this one-way, top-down approach to hazard communication is not necessarily effective or reliable. The messages which people take away will be dependent on the way in which they read, interpret, and understand the map, a facet of hazard communication which has been relatively unexplored. Decades of cartographic studies suggest that variables in the visual representation of data on maps, such as colour and symbology, can have a powerful effect on how people understand map content. In practice, however, there is little guidance or consistency in how hazard information is expressed and represented on maps. Accordingly, decisions are often made based on subjective preference, rather than research-backed principles. Here we present the results of a study in which we explore how hazard map design features can influence hazard map interpretation, and we propose a number of considerations for hazard map design. A series of hazard maps were generated, with each one showing the same probabilistic volcanic ashfall dataset, but using different verbal and visual variables (e.g., different colour schemes, data classifications, probabilistic formats). Following a short pilot study, these maps were used in an online survey of 110 stakeholders and scientists in New Zealand. Participants answered 30 open-ended and multiple choice questions about ashfall hazard based on the different maps. Results suggest that hazard map design can have a significant influence on the messages readers take away. For example, diverging colour schemes were associated with concepts of "risk" and decision-making more than sequential schemes, and participants made more precise estimates of hazard with isarithmic data classifications compared to binned or gradational shading. Based on such

Hazard Analysis Database Report

Energy Technology Data Exchange (ETDEWEB)

GAULT, G.W.

1999-10-13

The Hazard Analysis Database was developed in conjunction with the hazard analysis activities conducted in accordance with DOE-STD-3009-94, Preparation Guide for US Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports, for the Tank Waste Remediation System (TWRS) Final Safety Analysis Report (FSAR). The FSAR is part of the approved TWRS Authorization Basis (AB). This document describes, identifies, and defines the contents and structure of the TWRS FSAR Hazard Analysis Database and documents the configuration control changes made to the database. The TWRS Hazard Analysis Database contains the collection of information generated during the initial hazard evaluations and the subsequent hazard and accident analysis activities. The database supports the preparation of Chapters 3,4, and 5 of the TWRS FSAR and the USQ process and consists of two major, interrelated data sets: (1) Hazard Evaluation Database--Data from the results of the hazard evaluations; and (2) Hazard Topography Database--Data from the system familiarization and hazard identification.

Handbook of hazardous waste management

International Nuclear Information System (INIS)

Metry, A.A.

1980-01-01

The contents of this work are arranged so as to give the reader a detailed understanding of the elements of hazardous waste management. Generalized management concepts are covered in Chapters 1 through 5 which are entitled: Introduction, Regulations Affecting Hazardous Waste Management, Comprehensive Hazardous Waste Management, Control of Hazardous Waste Transportation, and Emergency Hazardous Waste Management. Chapters 6 through 11 deal with treatment concepts and are entitled: General Considerations for Hazardous Waste Management Facilities, Physical Treatment of Hazardous Wastes, Chemical Treatment of Hazardous Wastes, Biological Treatment of Hazardous Wastes, Incineration of Hazardous Wastes, and Hazardous Waste Management of Selected Industries. Chapters 12 through 15 are devoted to ultimate disposal concepts and are entitled: Land Disposal Facilities, Ocean Dumping of Hazardous Wastes, Disposal of Extremely Hazardous Wastes, and Generalized Criteria for Hazardous Waste Management Facilities

Egyptian Environmental Activities and Regulations for Management of Hazardous Substances and Hazardous Wastes

International Nuclear Information System (INIS)

El Zarka, M.

1999-01-01

A substantial use of hazardous substances is essential to meet the social and economic goals of the community in Egypt. Agrochemicals are being used extensively to increase crop yield. The outdated agrochemicals and their empty containers represent a serious environmental problem. Industrial development in different sectors in Egypt obligates handling of huge amounts of hazardous substances and hazardous wastes. The inappropriate handling of such hazardous substances creates several health and environmental problems. Egypt faces many challenges to control safe handling of such substances and wastes. Several regulations are governing handling of hazardous substances in Egypt. The unified Environmental Law 4 for the year 1994 includes a full chapter on the Management of Hazardous Substances and Hazardous Wastes. National and international activities have been taken to manage hazardous substances and hazardous wastes in an environmental sound manner

Hazard classification methodology

International Nuclear Information System (INIS)

Brereton, S.J.

1996-01-01

This document outlines the hazard classification methodology used to determine the hazard classification of the NIF LTAB, OAB, and the support facilities on the basis of radionuclides and chemicals. The hazard classification determines the safety analysis requirements for a facility

Communicación para el Cambio Social

DEFF Research Database (Denmark)

Denne antologi samler ialt 200 bidrag fra 150 forfattere som gennem tiderne har bidraget til udvikling af forskings- og praksisfeltet 'social forandringskommunikation'. Dette felt formulerer sig i opposition til den funktionalistisk orienterede strategiske kommunikations traditioner, og udvikles ...... omkring nøglebegreber som eksempelvis 'empowerment', dialog og borgerdeltagelse. Værket er det første af sin art der forsøger at skabe een samlet fortælling omkring 'communication for social change' set udfra et kritisk perspektiv.......Denne antologi samler ialt 200 bidrag fra 150 forfattere som gennem tiderne har bidraget til udvikling af forskings- og praksisfeltet 'social forandringskommunikation'. Dette felt formulerer sig i opposition til den funktionalistisk orienterede strategiske kommunikations traditioner, og udvikles...

''Hazardous'' terminology

International Nuclear Information System (INIS)

Powers, J.

1991-01-01

A number of terms (e.g., ''hazardous chemicals,'' ''hazardous materials,'' ''hazardous waste,'' and similar nomenclature) refer to substances that are subject to regulation under one or more federal environmental laws. State laws and regulations also provide additional, similar, or identical terminology that may be confused with the federally defined terms. Many of these terms appear synonymous, and it easy to use them interchangeably. However, in a regulatory context, inappropriate use of narrowly defined terms can lead to confusion about the substances referred to, the statutory provisions that apply, and the regulatory requirements for compliance under the applicable federal statutes. This information Brief provides regulatory definitions, a brief discussion of compliance requirements, and references for the precise terminology that should be used when referring to ''hazardous'' substances regulated under federal environmental laws. A companion CERCLA Information Brief (EH-231-004/0191) addresses ''toxic'' nomenclature

Hazard Analysis Database Report

CERN Document Server

Grams, W H

2000-01-01

The Hazard Analysis Database was developed in conjunction with the hazard analysis activities conducted in accordance with DOE-STD-3009-94, Preparation Guide for U S . Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports, for HNF-SD-WM-SAR-067, Tank Farms Final Safety Analysis Report (FSAR). The FSAR is part of the approved Authorization Basis (AB) for the River Protection Project (RPP). This document describes, identifies, and defines the contents and structure of the Tank Farms FSAR Hazard Analysis Database and documents the configuration control changes made to the database. The Hazard Analysis Database contains the collection of information generated during the initial hazard evaluations and the subsequent hazard and accident analysis activities. The Hazard Analysis Database supports the preparation of Chapters 3 ,4 , and 5 of the Tank Farms FSAR and the Unreviewed Safety Question (USQ) process and consists of two major, interrelated data sets: (1) Hazard Analysis Database: Data from t...

ThinkHazard!: an open-source, global tool for understanding hazard information

Science.gov (United States)

Fraser, Stuart; Jongman, Brenden; Simpson, Alanna; Nunez, Ariel; Deparday, Vivien; Saito, Keiko; Murnane, Richard; Balog, Simone

2016-04-01

Rapid and simple access to added-value natural hazard and disaster risk information is a key issue for various stakeholders of the development and disaster risk management (DRM) domains. Accessing available data often requires specialist knowledge of heterogeneous data, which are often highly technical and can be difficult for non-specialists in DRM to find and exploit. Thus, availability, accessibility and processing of these information sources are crucial issues, and an important reason why many development projects suffer significant impacts from natural hazards. The World Bank's Global Facility for Disaster Reduction and Recovery (GFDRR) is currently developing a new open-source tool to address this knowledge gap: ThinkHazard! The main aim of the ThinkHazard! project is to develop an analytical tool dedicated to facilitating improvements in knowledge and understanding of natural hazards among non-specialists in DRM. It also aims at providing users with relevant guidance and information on handling the threats posed by the natural hazards present in a chosen location. Furthermore, all aspects of this tool will be open and transparent, in order to give users enough information to understand its operational principles. In this presentation, we will explain the technical approach behind the tool, which translates state-of-the-art probabilistic natural hazard data into understandable hazard classifications and practical recommendations. We will also demonstrate the functionality of the tool, and discuss limitations from a scientific as well as an operational perspective.

Multi-Hazard Interactions in Guatemala

Science.gov (United States)

Gill, Joel; Malamud, Bruce D.

2017-04-01

In this paper, we combine physical and social science approaches to develop a multi-scale regional framework for natural hazard interactions in Guatemala. The identification and characterisation of natural hazard interactions is an important input for comprehensive multi-hazard approaches to disaster risk reduction at a regional level. We use five transdisciplinary evidence sources to organise and populate our framework: (i) internationally-accessible literature; (ii) civil protection bulletins; (iii) field observations; (iv) stakeholder interviews (hazard and civil protection professionals); and (v) stakeholder workshop results. These five evidence sources are synthesised to determine an appropriate natural hazard classification scheme for Guatemala (6 hazard groups, 19 hazard types, and 37 hazard sub-types). For a national spatial extent (Guatemala), we construct and populate a "21×21" hazard interaction matrix, identifying 49 possible interactions between 21 hazard types. For a sub-national spatial extent (Southern Highlands, Guatemala), we construct and populate a "33×33" hazard interaction matrix, identifying 112 possible interactions between 33 hazard sub-types. Evidence sources are also used to constrain anthropogenic processes that could trigger natural hazards in Guatemala, and characterise possible networks of natural hazard interactions (cascades). The outcomes of this approach are among the most comprehensive interaction frameworks for national and sub-national spatial scales in the published literature. These can be used to support disaster risk reduction and civil protection professionals in better understanding natural hazards and potential disasters at a regional scale.

Solcelle & Sollys - et arkitektonisk potentiale

DEFF Research Database (Denmark)

Hansen, Ellen Kathrine

2001-01-01

Udført i samarbejde med Teknologisk Institut med projektet "Udvikling af bygningsintegreret PEC solcelle".......Udført i samarbejde med Teknologisk Institut med projektet "Udvikling af bygningsintegreret PEC solcelle"....

Influence of shielding gas on fume formation rate and particle size distribution for optimised GMAW

International Nuclear Information System (INIS)

Carpenter, K.R.; Monaghan, B.J.; Nicholson, A.; Cuiuri, D.; Norrish, J.

2010-01-01

The influence of shielding gas on fume formation rate (FFR) and particle size distribution has been investigated by using a technique developed for automatic control of the welding voltage in gas metal arc welding (GMAW). The results for automatic control are compared with the use of a fixed voltage. Significant reductions in FFR and a general decrease in average particle size were observed using the automatic control technique. This reduction in FFR was attributed to improved metal transfer stability, via a reduction in the occurrence of repelled globular transfer, by promoting the 'drop-spray' transfer condition, together with a reduction in the arc length. FFR and particle size were strongly related to the C O2 content of the shielding gas, where FFR increased as percent C 02 increased, due mainly to the dominant influence of C O2 on weld transfer and arc characteristics. The results indicate that FFR for GMAW in the spray regime should be determined by using optimised welding conditions for each shielding gas composition.

Mechanism of alkalinity lowering and chemical equilibrium model of high fly ash silica fume cement

International Nuclear Information System (INIS)

Hoshino, Seiichi; Honda, Akira; Negishi, Kumi

2014-01-01

The mechanism of alkalinity lowering of a High Fly ash Silica fume Cement (HFSC) under liquid/solid ratio conditions where the pH is largely controlled by the soluble alkali components (Region I) has been studied. This mechanism was incorporated in the chemical equilibrium model of HFSC. As a result, it is suggested that the dissolution and precipitation behavior of SO 4 2- partially contributes to alkalinity lowering of HFSC in Region I. A chemical equilibrium model of HFSC incorporating alkali (Na, K) adsorption, which was presumed as another contributing factor of the alkalinity lowering effect, was also developed, and an HFSC immersion experiment was analyzed using the model. The results of the developed model showed good agreement with the experiment results. From the above results, it was concluded that the alkalinity lowering of HFSC in Region I was attributed to both the dissolution and precipitation behavior of SO 4 2- and alkali adsorption, in addition to the absence of Ca(OH) 2 . A chemical equilibrium model of HFSC incorporating alkali and SO 4 2- adsorption was also proposed. (author)

Path Dependence

DEFF Research Database (Denmark)

Madsen, Mogens Ove

Begrebet Path Dependence blev oprindelig udviklet inden for New Institutionel Economics af bl.a. David, Arthur og North. Begrebet har spredt sig vidt i samfundsvidenskaberne og undergået en udvikling. Dette paper propagerer for at der er sket så en så omfattende udvikling af begrebet, at man nu kan...... tale om 1. og 2. generation af Path Dependence begrebet. Den nyeste udvikling af begrebet har relevans for metodologi-diskusionerne i relation til Keynes...

Hazard management at the workplace

International Nuclear Information System (INIS)

Hasfazilah Hassan; Azimawati Ahmad; Syed Asraf Fahlawi Wafa S M Ghazi; Hairul Nizam Idris

2005-01-01

Failure to ensure health and safety environment at workplace will cause an accident involving loss to the time, human resource, finance and for the worse case effect the moral value of an organization. If we go through to the cause of the accident, it is impossible to have a totally safety workplace. It is because every process in work activities has it own hazard elements. The purpose of this paper is to discuss the best action to prevent from the hazard with a comprehensive and effectiveness hazard management. Hazard management is the one of the pro-active hazard control. With this we manage to identify and evaluate the hazard and control the hazard risk. Therefore, hazard management should be screened constantly and continuously to make sure work hazard always in control. (Author)

DOE Hazardous Waste Program

International Nuclear Information System (INIS)

Eyman, L.D.; Craig, R.B.

1985-01-01

The goal of the DOE Hazardous Waste Program is to support the implementation and improvement of hazardous-chemical and mixed-radioactive-waste management such that public health, safety, and the environment are protected and DOE missions are effectively accomplished. The strategy for accomplishing this goal is to define the character and magnitude of hazardous wastes emanating from DOE facilities, determine what DOE resources are available to address these problems, define the regulatory and operational constraints, and develop programs and plans to resolve hazardous waste issues. Over the longer term the program will support the adaptation and application of technologies to meet hazardous waste management needs and to implement an integrated, DOE-wide hazardous waste management strategy. 1 reference, 1 figure

Biomonitoring for iron, manganese, chromium, aluminum, nickel and cadmium in workers exposed to welding fume: a preliminary study

Directory of Open Access Journals (Sweden)

Mulyana

2015-05-01

Full Text Available The control of exposure to welding fumes is increasing importance in promoting a healthy, safe and productive work environment. This study is a case-control design, random study was conducted among welder (56 subjects and non welder (39 subjects with more than 1 years experience in the same job task in an automotive parts manufactory within the industrial area at Cikarang in 2013. All subjects were completed physical examination, informed consent and questionnaire. Blood heavy metals were determined by Inductively-Coupled Plasma Mass Spectrometry (ICP-MS. Whole blood iron, manganese, chromium and lead in welder were higher than non-welder, but not different for aluminum, nickel and cadmium. In welder, chromium and manganese correlated with smoking status, cadmium correlated with age and smoking status. In multivariate analysis, wholeblood cadmium correlates with age and smoking status.

Relative Hazard Calculation Methodology

International Nuclear Information System (INIS)

DL Strenge; MK White; RD Stenner; WB Andrews

1999-01-01

The methodology presented in this document was developed to provide a means of calculating the RH ratios to use in developing useful graphic illustrations. The RH equation, as presented in this methodology, is primarily a collection of key factors relevant to understanding the hazards and risks associated with projected risk management activities. The RH equation has the potential for much broader application than generating risk profiles. For example, it can be used to compare one risk management activity with another, instead of just comparing it to a fixed baseline as was done for the risk profiles. If the appropriate source term data are available, it could be used in its non-ratio form to estimate absolute values of the associated hazards. These estimated values of hazard could then be examined to help understand which risk management activities are addressing the higher hazard conditions at a site. Graphics could be generated from these absolute hazard values to compare high-hazard conditions. If the RH equation is used in this manner, care must be taken to specifically define and qualify the estimated absolute hazard values (e.g., identify which factors were considered and which ones tended to drive the hazard estimation)

JazzDanmark

DEFF Research Database (Denmark)

Harsløf, Olav

2009-01-01

Artikel om genreorganisationen JazzDanmarks udvikling fra Dansk Jazz Forbund til JazzDanmark Udgivelsesdato: April-maj......Artikel om genreorganisationen JazzDanmarks udvikling fra Dansk Jazz Forbund til JazzDanmark Udgivelsesdato: April-maj...

Application of the key characteristics of carcinogens in cancer hazard identification

Science.gov (United States)

Guyton, Kathryn Z; Rusyn, Ivan; Chiu, Weihsueh A; Corpet, Denis E; van den Berg, Martin; Ross, Matthew K; Christiani, David C; Beland, Frederick A; Smith, Martyn T

2018-01-01

Abstract Smith et al. (Env. Health Perspect. 124: 713, 2016) identified 10 key characteristics (KCs), one or more of which are commonly exhibited by established human carcinogens. The KCs reflect the properties of a cancer-causing agent, such as ‘is genotoxic,’ ‘is immunosuppressive’ or ‘modulates receptor-mediated effects,’ and are distinct from the hallmarks of cancer, which are the properties of tumors. To assess feasibility and limitations of applying the KCs to diverse agents, methods and results of mechanistic data evaluations were compiled from eight recent IARC Monograph meetings. A systematic search, screening and evaluation procedure identified a broad literature encompassing multiple KCs for most (12/16) IARC Group 1 or 2A carcinogens identified in these meetings. Five carcinogens are genotoxic and induce oxidative stress, of which pentachlorophenol, hydrazine and malathion also showed additional KCs. Four others, including welding fumes, are immunosuppressive. The overall evaluation was upgraded to Group 2A based on mechanistic data for only two agents, tetrabromobisphenol A and tetrachloroazobenzene. Both carcinogens modulate receptor-mediated effects in combination with other KCs. Fewer studies were identified for Group 2B or 3 agents, with the vast majority (17/18) showing only one or no KCs. Thus, an objective approach to identify and evaluate mechanistic studies pertinent to cancer revealed strong evidence for multiple KCs for most Group 1 or 2A carcinogens but also identified opportunities for improvement. Further development and mapping of toxicological and biomarker endpoints and pathways relevant to the KCs can advance the systematic search and evaluation of mechanistic data in carcinogen hazard identification. PMID:29562322

Natural hazards science strategy

Science.gov (United States)

Holmes, Robert R.; Jones, Lucile M.; Eidenshink, Jeffery C.; Godt, Jonathan W.; Kirby, Stephen H.; Love, Jeffrey J.; Neal, Christina A.; Plant, Nathaniel G.; Plunkett, Michael L.; Weaver, Craig S.; Wein, Anne; Perry, Suzanne C.

2012-01-01

The mission of the U.S. Geological Survey (USGS) in natural hazards is to develop and apply hazard science to help protect the safety, security, and economic well-being of the Nation. The costs and consequences of natural hazards can be enormous, and each year more people and infrastructure are at risk. USGS scientific research—founded on detailed observations and improved understanding of the responsible physical processes—can help to understand and reduce natural hazard risks and to make and effectively communicate reliable statements about hazard characteristics, such as frequency, magnitude, extent, onset, consequences, and where possible, the time of future events.To accomplish its broad hazard mission, the USGS maintains an expert workforce of scientists and technicians in the earth sciences, hydrology, biology, geography, social and behavioral sciences, and other fields, and engages cooperatively with numerous agencies, research institutions, and organizations in the public and private sectors, across the Nation and around the world. The scientific expertise required to accomplish the USGS mission in natural hazards includes a wide range of disciplines that this report refers to, in aggregate, as hazard science.In October 2010, the Natural Hazards Science Strategy Planning Team (H–SSPT) was charged with developing a long-term (10-year) Science Strategy for the USGS mission in natural hazards. This report fulfills that charge, with a document hereinafter referred to as the Strategy, to provide scientific observations, analyses, and research that are critical for the Nation to become more resilient to natural hazards. Science provides the information that decisionmakers need to determine whether risk management activities are worthwhile. Moreover, as the agency with the perspective of geologic time, the USGS is uniquely positioned to extend the collective experience of society to prepare for events outside current memory. The USGS has critical statutory

Radiation hazards

International Nuclear Information System (INIS)

Rausch, L.

1979-01-01

On a scientific basis and with the aid of realistic examples, the author gives a popular introduction to an understanding and judgment of the public discussion over radiation hazards: Uses and hazards of X-ray examinations, biological radiation effects, civilisation risks in comparison, origins and explanation of radiation protection regulations. (orig.) [de

Hazard screening application guide

International Nuclear Information System (INIS)

1992-06-01

The basic purpose of hazard screening is to group precesses, facilities, and proposed modifications according to the magnitude of their hazards so as to determine the need for and extent of follow on safety analysis. A hazard is defined as a material, energy source, or operation that has the potential to cause injury or illness in human beings. The purpose of this document is to give guidance and provide standard methods for performing hazard screening. Hazard screening is applied to new and existing facilities and processes as well as to proposed modifications to existing facilities and processes. The hazard screening process evaluates an identified hazards in terms of the effects on people, both on-site and off-site. The process uses bounding analyses with no credit given for mitigation of an accident with the exception of certain containers meeting DOT specifications. The process is restricted to human safety issues only. Environmental effects are addressed by the environmental program. Interfaces with environmental organizations will be established in order to share information

Software safety hazard analysis

International Nuclear Information System (INIS)

Lawrence, J.D.

1996-02-01

Techniques for analyzing the safety and reliability of analog-based electronic protection systems that serve to mitigate hazards in process control systems have been developed over many years, and are reasonably well understood. An example is the protection system in a nuclear power plant. The extension of these techniques to systems which include digital computers is not well developed, and there is little consensus among software engineering experts and safety experts on how to analyze such systems. One possible technique is to extend hazard analysis to include digital computer-based systems. Software is frequently overlooked during system hazard analyses, but this is unacceptable when the software is in control of a potentially hazardous operation. In such cases, hazard analysis should be extended to fully cover the software. A method for performing software hazard analysis is proposed in this paper

University of Missouri research reactor exhaust ventilation/laboratory fume hood upgrade

International Nuclear Information System (INIS)

Edwards, C.B. Jr.; McKibben, J.C.; McCracken, C.B.

1989-01-01

The University of Missouri research reactor (MURR) facility is located in Research Park, 1 mile south of the Columbia campus. The reactor is a 10-MW pressurized loop, in-pool-type, light-water-moderated, beryllium-and-graphite-reflected core, serviced by six radial beam tubes for research, and has sample irradiation facilities in both a flux trap and in the graphite region. The reactor operates at full power 150 h/week, 52 week/yr, making it one of the best operating schedules and the most extensively used of any university research reactor. This extensive utilization includes many programs, such as radioisotope applications, neutron activation analysis, etc., that depend heavily on fume hoods, glove boxes, and hot cells that put a tremendous demand on the exhaust system. The exhaust system is required to be operable whenever the reactor is operating and must have the capability of being operated from an emergency electrical generator on loss of site electrical power. The originally installed exhaust ventilation system was below needed capacity and, with increased program requirements and system age, the necessity to upgrade the system was paramount. The challenge was to complete the upgrade construction while continuing to operate the reactor and maintain all the other ongoing programs, rather than take the easy way of an extended shutdown. This paper discusses how MURR met this challenge and solved these problems, problems that are similarly experienced by almost all research reactors to some degree when major work is required on critical systems

Job Hazard Analysis

National Research Council Canada - National Science Library

1998-01-01

.... Establishing proper job procedures is one of the benefits of conducting a job hazard analysis carefully studying and recording each step of a job, identifying existing or potential job hazards...

Introduction: Hazard mapping

Science.gov (United States)

Baum, Rex L.; Miyagi, Toyohiko; Lee, Saro; Trofymchuk, Oleksandr M

2014-01-01

Twenty papers were accepted into the session on landslide hazard mapping for oral presentation. The papers presented susceptibility and hazard analysis based on approaches ranging from field-based assessments to statistically based models to assessments that combined hydromechanical and probabilistic components. Many of the studies have taken advantage of increasing availability of remotely sensed data and nearly all relied on Geographic Information Systems to organize and analyze spatial data. The studies used a range of methods for assessing performance and validating hazard and susceptibility models. A few of the studies presented in this session also included some element of landslide risk assessment. This collection of papers clearly demonstrates that a wide range of approaches can lead to useful assessments of landslide susceptibility and hazard.

Barrow hazards survey

International Nuclear Information System (INIS)

1980-06-01

Following a series of public meetings at which PERG presented the results of a literature review and site specific accident study of the hazards of the maritime transport of spent nuclear reactor fuel to Barrow (en route to the Windscale reprocessing works), PERG was requested by the Planning Committee of Barrow Town Council to prepare an assessment of the interaction of the hazards arising from the concentration of nuclear activities in the area with those of a proposed gas-terminal. This report presents a preliminary review of the Environmental Impact Assessments prepared by the Borough Surveyor and a critical appraisal of the hazard analyses undertaken by the Health and Safety Executive, and the consultants to Cumbria County Council on this matter, the Safety and Reliability Directorate of the United Kingdom Atomic Energy Authority. After a general and historical introduction, the document continues under the following headings: a description of the hazards (BNFL spent fuel shipments; the gas terminal; gas condensate storage; the Vickers shipyard (involving nuclear powered submarines)); the interaction of hazards; planning implications and democratic decisions; recommendations. (U.K.)

76 FR 4823 - Hazardous Waste Management System; Identifying and Listing Hazardous Waste Exclusion

Science.gov (United States)

2011-01-27

... Waste Management System; Identifying and Listing Hazardous Waste Exclusion AGENCY: Environmental... hazardous wastes. The Agency has decided to grant the petition based on an evaluation of waste-specific... excludes the petitioned waste from the requirements of hazardous waste regulations under the Resource...

Structural comparison of hazardous and non-hazardous coals based on gas sorption experiments

Energy Technology Data Exchange (ETDEWEB)

Lakatos, J.; Toth, J. [Research Lab. for Mining Chemistry, Hungarian Academy of Sciences, Miskolc-Egyetemvaros (Hungary); Radnai-Gyoengyoes, Z. [Geopard Ltd., Pecs (Hungary); Bokanyi, L. [Miskolc Univ., Miskolc-Egyetemvaros (Hungary). Dept. of Process Engineering

1997-12-31

Comparison of carbon-dioxide and propane sorption at ambient temperature was used for characterising the difference of the structure of hazardous and non hazardous coals. However, hazardous coals were found more microporous or contain more closed pores than non hazardous ones, this difference couldn`t have been enlarged and attributed to one petrographic component by producing the density fractions. Gas sorption isobars (nitrogen, methane, ethane) are proposed to make a distinction between fine pore structure of coals. (orig.)

Informing Workers of Chemical Hazards: The OSHA Hazard Communication Standard.

Science.gov (United States)

American Chemical Society, Washington, DC.

Practical information on how to implement a chemical-related safety program is outlined in this publication. Highlights of the federal Occupational Safety and Health Administrations (OSHA) Hazard Communication Standard are presented and explained. These include: (1) hazard communication requirements (consisting of warning labels, material safety…

Transport of hazardous goods

International Nuclear Information System (INIS)

1989-01-01

The course 'Transport of hazardous goods' was held in Berlin in November 1988 in cooperation with the Bundesanstalt fuer Materialforschung und -pruefung. From all lecturs, two are recorded separately: 'Safety of tank trucks - requirements on the tank, development possibiities of active and passive safety' and 'Requirements on the transport of radioactive materials - possible derivations for other hazardous goods'. The other lectures deal with hazardous goods law, requirements on packinging, risk assessment, railroad transport, hazardous goods road network, insurance matters, EC regulations, and waste tourism. (HSCH) [de

Seismic hazard maps for Haiti

Science.gov (United States)

Frankel, Arthur; Harmsen, Stephen; Mueller, Charles; Calais, Eric; Haase, Jennifer

2011-01-01

We have produced probabilistic seismic hazard maps of Haiti for peak ground acceleration and response spectral accelerations that include the hazard from the major crustal faults, subduction zones, and background earthquakes. The hazard from the Enriquillo-Plantain Garden, Septentrional, and Matheux-Neiba fault zones was estimated using fault slip rates determined from GPS measurements. The hazard from the subduction zones along the northern and southeastern coasts of Hispaniola was calculated from slip rates derived from GPS data and the overall plate motion. Hazard maps were made for a firm-rock site condition and for a grid of shallow shear-wave velocities estimated from topographic slope. The maps show substantial hazard throughout Haiti, with the highest hazard in Haiti along the Enriquillo-Plantain Garden and Septentrional fault zones. The Matheux-Neiba Fault exhibits high hazard in the maps for 2% probability of exceedance in 50 years, although its slip rate is poorly constrained.

Flow injection determination of lead and cadmium in hair samples from workers exposed to welding fumes

International Nuclear Information System (INIS)

Cespon-Romero, R.M.; Yebra-Biurrun, M.C.

2007-01-01

A flow injection procedure involving continuous acid leaching for lead and cadmium determination in hair samples of persons in permanent contact with a polluted workplace environment by flame atomic absorption spectrometry is proposed. Variables such as sonication time, nature and concentration of the acid solution used as leaching solution, leaching temperature, flow-rate of the continuous manifold, leaching solution volume and hair particle size were simultaneously studied by applying a Plackett-Burman design approach. Results showed that nitric acid concentration (leaching solution), leaching temperature and sonication time were statistically significant variables (confidence interval of 95%). These last two variables were finally optimised by using a central composite design. The proposed procedure allowed the determination of cadmium and lead with limits of detection 0.1 and 1.0 μg g -1 , respectively. The accuracy of the developed procedure was evaluated by the analysis of a certified reference material (CRM 397, human hair, from the BCR). The proposed method was applied with satisfactory results to the determination of Cd and Pb in human hair samples of workers exposed to welding fumes

INTERNAL HAZARDS ANALYSIS FOR LICENSE APPLICATION

Energy Technology Data Exchange (ETDEWEB)

R.J. Garrett

2005-02-17

The purpose of this internal hazards analysis is to identify and document the internal hazards and potential initiating events associated with preclosure operations of the repository at Yucca Mountain. Internal hazards are those hazards presented by the operation of the facility and by its associated processes that can potentially lead to a radioactive release or cause a radiological hazard. In contrast to external hazards, internal hazards do not involve natural phenomena and external man-made hazards. This internal hazards analysis was performed in support of the preclosure safety analysis and the License Application for the Yucca Mountain Project. The methodology for this analysis provides a systematic means to identify internal hazards and potential initiating events that may result in a radiological hazard or radiological release during the repository preclosure period. These hazards are documented in tables of potential internal hazards and potential initiating events (Section 6.6) for input to the repository event sequence categorization process. The results of this analysis will undergo further screening and analysis based on the criteria that apply to the performance of event sequence analyses for the repository preclosure period. The evolving design of the repository will be re-evaluated periodically to ensure that internal hazards that have not been previously evaluated are identified.

INTERNAL HAZARDS ANALYSIS FOR LICENSE APPLICATION

International Nuclear Information System (INIS)

Garrett, R.J.

2005-01-01

The purpose of this internal hazards analysis is to identify and document the internal hazards and potential initiating events associated with preclosure operations of the repository at Yucca Mountain. Internal hazards are those hazards presented by the operation of the facility and by its associated processes that can potentially lead to a radioactive release or cause a radiological hazard. In contrast to external hazards, internal hazards do not involve natural phenomena and external man-made hazards. This internal hazards analysis was performed in support of the preclosure safety analysis and the License Application for the Yucca Mountain Project. The methodology for this analysis provides a systematic means to identify internal hazards and potential initiating events that may result in a radiological hazard or radiological release during the repository preclosure period. These hazards are documented in tables of potential internal hazards and potential initiating events (Section 6.6) for input to the repository event sequence categorization process. The results of this analysis will undergo further screening and analysis based on the criteria that apply to the performance of event sequence analyses for the repository preclosure period. The evolving design of the repository will be re-evaluated periodically to ensure that internal hazards that have not been previously evaluated are identified

De værdige byrum i Cape Town

DEFF Research Database (Denmark)

Gehl, Jan; Damm van Deurs, Camilla

2004-01-01

Om Dignified Places-programmet hvor byens fællesrum anvendes som katalysatorer for den begyndende udvikling i fattige townships.......Om Dignified Places-programmet hvor byens fællesrum anvendes som katalysatorer for den begyndende udvikling i fattige townships....

On the processes of transformation in architectural - architectural education

DEFF Research Database (Denmark)

Reese, Dan

2002-01-01

Essay om arkitekturens og arkitektuddannelsens transformationer. Udvikling af et undervisningsprogram set i relation til samfundsudviklingen. Bidrag til EAAE konkurrence......Essay om arkitekturens og arkitektuddannelsens transformationer. Udvikling af et undervisningsprogram set i relation til samfundsudviklingen. Bidrag til EAAE konkurrence...

Perspectivas para la lexicografía especializada en Cuba

DEFF Research Database (Denmark)

Tarp, Sven

1995-01-01

En diskussion af muligheder for at udvikle et fagleksikografisk arbejde på Cuba og i det øvrige Latinamerika......En diskussion af muligheder for at udvikle et fagleksikografisk arbejde på Cuba og i det øvrige Latinamerika...

76 FR 55846 - Hazardous Waste Management System: Identification and Listing of Hazardous Waste: Carbon Dioxide...

Science.gov (United States)

2011-09-09

... carbon dioxide (CO 2 ) streams that are hazardous from the definition of hazardous waste, provided these... management under the Resource Conservation and Recovery Act (RCRA) to conditionally exclude carbon dioxide... 2050-AG60 Hazardous Waste Management System: Identification and Listing of Hazardous Waste: Carbon...

HAZARD ANALYSIS SOFTWARE

International Nuclear Information System (INIS)

Sommer, S; Tinh Tran, T.

2008-01-01

Washington Safety Management Solutions, LLC developed web-based software to improve the efficiency and consistency of hazard identification and analysis, control selection and classification, and to standardize analysis reporting at Savannah River Site. In the new nuclear age, information technology provides methods to improve the efficiency of the documented safety analysis development process which includes hazard analysis activities. This software provides a web interface that interacts with a relational database to support analysis, record data, and to ensure reporting consistency. A team of subject matter experts participated in a series of meetings to review the associated processes and procedures for requirements and standard practices. Through these meetings, a set of software requirements were developed and compiled into a requirements traceability matrix from which software could be developed. The software was tested to ensure compliance with the requirements. Training was provided to the hazard analysis leads. Hazard analysis teams using the software have verified its operability. The software has been classified as NQA-1, Level D, as it supports the analysis team but does not perform the analysis. The software can be transported to other sites with alternate risk schemes. The software is being used to support the development of 14 hazard analyses. User responses have been positive with a number of suggestions for improvement which are being incorporated as time permits. The software has enforced a uniform implementation of the site procedures. The software has significantly improved the efficiency and standardization of the hazard analysis process

Number size distribution of fine and ultrafine fume particles from various welding processes.

Science.gov (United States)

Brand, Peter; Lenz, Klaus; Reisgen, Uwe; Kraus, Thomas

2013-04-01

Studies in the field of environmental epidemiology indicate that for the adverse effect of inhaled particles not only particle mass is crucial but also particle size is. Ultrafine particles with diameters below 100 nm are of special interest since these particles have high surface area to mass ratio and have properties which differ from those of larger particles. In this paper, particle size distributions of various welding and joining techniques were measured close to the welding process using a fast mobility particle sizer (FMPS). It turned out that welding processes with high mass emission rates (manual metal arc welding, metal active gas welding, metal inert gas welding, metal inert gas soldering, and laser welding) show mainly agglomerated particles with diameters above 100 nm and only few particles in the size range below 50 nm (10 to 15%). Welding processes with low mass emission rates (tungsten inert gas welding and resistance spot welding) emit predominantly ultrafine particles with diameters well below 100 nm. This finding can be explained by considerably faster agglomeration processes in welding processes with high mass emission rates. Although mass emission is low for tungsten inert gas welding and resistance spot welding, due to the low particle size of the fume, these processes cannot be labeled as toxicologically irrelevant and should be further investigated.

Reduction of cooking oil fume exposure following an engineering intervention in Chinese restaurants.

Science.gov (United States)

Pan, Chih-Hong; Shih, Tung-Sheng; Chen, Chiou-Jong; Hsu, Jin-Huei; Wang, Shun-Chih; Huang, Chien-Ping; Kuo, Ching-Tang; Wu, Kuen-Yuh; Hu, Howard; Chan, Chang-Chuan

2011-01-01

A new engineering intervention measure, an embracing air curtain device (EACD), was used to increase the capture efficiency of cooker hoods and reduce cooking oil fume (COF) exposure in Chinese restaurants. An EACD was installed in six Chinese restaurants where the cooks complained of COF exposure. Before- and after-installation measurements were taken to compare changes in particulate matter (PM) and polycyclic aromatic hydrocarbons (PAHs) in kitchen air, and changes in levels of urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and malondialdehyde (MDA). The association between PM and PAHs in air and 8-OHdG and MDA in urine was evaluated by linear mixed-effects regression analysis. Results showed that geometric mean kitchen air levels of PM(10), PM(2.5), PM(1.0) and total particulate PAHs were significantly reduced after the EACDs were introduced. Urinary levels of 8-OHdG and MDA in cooks were also significantly lower after EACD instalment. PM(2.5), PM(1.0) and benzo(a)pyrene (BaP) levels were positively associated with urinary 8-OHdG levels after adjusting for key personal covariates. Urinary MDA levels in cooks were also positively associated with BaP levels after adjusting for key personal covariates. This study demonstrates that the EACD is effective for reducing COF and oxidative stress levels in cooks working in Chinese kitchens.

Fumed and Precipitated Hydrophilic Silica Suspension Gels in Mineral Oil: Stability and Rheological Properties

Directory of Open Access Journals (Sweden)

Yoshiki Sugino

2017-08-01

Full Text Available Hydrophilic fumed silica (FS and precipitated silica (PS powders were suspended in mineral oil; increasing the silica volume fraction (φ in the suspension led to the formation of sol, pre-gel, and gel states. Gelation took place at lower φ values in the FS than the PS suspension because of the lower silanol density on the FS surface. The shear stresses and dynamic moduli of the FS and PS suspensions were measured as a function of φ. Plots of the apparent shear viscosity against shear rate depended on φ and the silica powder. The FS suspensions in the gel state exhibited shear thinning, followed by a weak shear thickening or by constant viscosity with an increasing shear rate. In contrast, the PS suspensions in the gel state showed shear thinning, irrespective of φ. The dynamic moduli of the pre-gel and gel states were dependent on the surface silanol density: at a fixed φ, the storage modulus G′ in the linear viscoelasticity region was larger for the FS than for the PS suspension. Beyond the linear region, the G′ of the PS suspensions showed strain hardening and the loss modulus G″ of the FS and PS suspensions exhibited weak strain overshoot.

Hazardous Chemicals

Centers for Disease Control (CDC) Podcasts

Chemicals are a part of our daily lives, providing many products and modern conveniences. With more than three decades of experience, The Centers for Disease Control and Prevention (CDC) has been in the forefront of efforts to protect and assess people's exposure to environmental and hazardous chemicals. This report provides information about hazardous chemicals and useful tips on how to protect you and your family from harmful exposure.

Technical Guidance for Hazardous Analysis, Emergency Planning for Extremely Hazardous Substances

Science.gov (United States)

This current guide supplements NRT-1 by providing technical assistance to LEPCs to assess the lethal hazards related to potential airborne releases of extremely hazardous substances (EHSs) as designated under Section 302 of Title Ill of SARA.

Introduction

DEFF Research Database (Denmark)

Darsø, Lotte; Kerr, Cheryl

2008-01-01

Introduktion til special issue om hvordan kunstneriske processer kan bidrage til udvikling af ledelse, management, læring og uddannelse......Introduktion til special issue om hvordan kunstneriske processer kan bidrage til udvikling af ledelse, management, læring og uddannelse...

Sproglige læringsprocesser og IT

DEFF Research Database (Denmark)

Ambjørn, Lone

2002-01-01

Sproglæringsteoretisk værktøj til udvikling af IT-støttede materialer og programmer til sprogundervisningen......Sproglæringsteoretisk værktøj til udvikling af IT-støttede materialer og programmer til sprogundervisningen...

The Coastal Hazard Wheel system for coastal multi-hazard assessment & management in a changing climate

DEFF Research Database (Denmark)

Appelquist, Lars Rosendahl; Halsnæs, Kirsten

2015-01-01

This paper presents the complete Coastal Hazard Wheel (CHW) system, developed for multi-hazard-assessment and multi-hazard-management of coastal areas worldwide under a changing climate. The system is designed as a low-tech tool that can be used in areas with limited data availability...... screening and management. The system is developed to assess the main coastal hazards in a single process and covers the hazards of ecosystem disruption, gradual inundation, salt water intrusion, erosion and flooding. The system was initially presented in 2012 and based on a range of test......-applications and feedback from coastal experts, the system has been further refined and developed into a complete hazard management tool. This paper therefore covers the coastal classification system used by the CHW, a standardized assessment procedure for implementation of multi-hazard-assessments, technical guidance...

Disposal of hazardous wastes

International Nuclear Information System (INIS)

Barnhart, B.J.

1978-01-01

The Fifth Life Sciences Symposium entitled Hazardous Solid Wastes and Their Disposal on October 12 through 14, 1977 was summarized. The topic was the passage of the National Resources Conservation and Recovery Act of 1976 will force some type of action on all hazardous solid wastes. Some major points covered were: the formulation of a definition of a hazardous solid waste, assessment of long-term risk, list of specific materials or general criteria to specify the wastes of concern, Bioethics, sources of hazardous waste, industrial and agricultural wastes, coal wastes, radioactive wastes, and disposal of wastes

Digital udvikling

DEFF Research Database (Denmark)

Ebbesen, Toke Riis

2015-01-01

En blog om design, materialitet og bøger i krydsfeltet mellem digitale udfordringer og en kulturel optik.......En blog om design, materialitet og bøger i krydsfeltet mellem digitale udfordringer og en kulturel optik....

Offsite transportation hazards assessment

International Nuclear Information System (INIS)

Burnside, M.E.

1997-01-01

This report documents the emergency preparedness Hazards Assessment for the offsite transportation of hazardous material from the Hanford Site. The assessment is required by the US Department of Energy (DOE) Order 151.1. Offsite transportation accidents are categorized using the DOE system to assist communication within the DOE and assure that appropriate assistance is provided to the people in charge at the scene. The assistance will initially include information about the load and the potential hazards. Local authorities will use the information to protect the public following a transportation accident. This Hazards Assessment will focus on the material being transported from the Hanford Site. Shipments coming to Hanford are the responsibility of the shipper and the carrier and, therefore, are not included in this Hazards Assessment, unless the DOE elects to be the shipper of record

Nature and morphology of fumed oxides and features of interfacial phenomena

International Nuclear Information System (INIS)

Gun’ko, V.M.; Zarko, V.I.; Goncharuk, O.V.; Matkovsky, A.K.; Remez, O.S.; Skubiszewska-Zięba, J.; Wojcik, G.; Walusiak, B.; Blitz, J.P.

2016-01-01

Graphical abstract: - Highlights: • Effects of oxide surface structure on interfacial behavior of nonpolar and polar adsorbates. • Confined space effects on freezing and melting temperatures of bound adsorbates. • Equilibrium adsorption and evaporation rate vs. structure of nanooxide adsorbents. - Abstract: Individual and complex fumed nanooxides were studied using high-resolution transmission electron microscopy, X-ray diffraction, ultraviolet-visible (UV–vis) spectroscopy, differential scanning calorimetry, nuclear magnetic resonance spectroscopy, adsorption, desorption (evaporation), and quantum chemical methods. For mixed nanooxides in contrast to simple and small nanoparticles of individual silica or titania, complex core–shell nanoparticles (50–200 nm in size) with titania or alumina cores and silica or alumina shells can be destroyed under high-pressure cryogelation (HPCG), mechnochemical activation (MCA) that also affect the structure of aggregates of nanoparticles and agglomerates of aggregates becoming more compacted. This is accompanied by changes in color from white to beige of different tints and changes in the UV–vis spectra in the 300–600 nm range, as well as changes in crystalline structure of alumina. Any treatment of ‘soft’ nanooxides affects the interfacial behavior of polar and nonpolar adsorbates. For some of them, the hysteresis loops become strongly open. Rearrangement of secondary particles affects the freezing-melting point depression. Clusterization of adsorbates bound in pores causes diminution of heat effects during phase transition (freezing, fusion). Freezing point depression and increasing melting point cause significant hysteresis freezing-melting effects for adsorbates bound to oxide nanoparticles. The study shows that complex nanooxides can be more sensitive to external actions than simple nanooxides such as silica.

Nature and morphology of fumed oxides and features of interfacial phenomena

Energy Technology Data Exchange (ETDEWEB)

Gun’ko, V.M., E-mail: vlad_gunko@ukr.net [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kyiv (Ukraine); Zarko, V.I.; Goncharuk, O.V.; Matkovsky, A.K.; Remez, O.S. [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kyiv (Ukraine); Skubiszewska-Zięba, J.; Wojcik, G. [Faculty of Chemistry, Maria Curie-Skłodowska University, 20-031 Lublin (Poland); Walusiak, B.; Blitz, J.P. [Eastern Illinois University, Department of Chemistry, Charleston, IL 61920 (United States)

2016-03-15

Graphical abstract: - Highlights: • Effects of oxide surface structure on interfacial behavior of nonpolar and polar adsorbates. • Confined space effects on freezing and melting temperatures of bound adsorbates. • Equilibrium adsorption and evaporation rate vs. structure of nanooxide adsorbents. - Abstract: Individual and complex fumed nanooxides were studied using high-resolution transmission electron microscopy, X-ray diffraction, ultraviolet-visible (UV–vis) spectroscopy, differential scanning calorimetry, nuclear magnetic resonance spectroscopy, adsorption, desorption (evaporation), and quantum chemical methods. For mixed nanooxides in contrast to simple and small nanoparticles of individual silica or titania, complex core–shell nanoparticles (50–200 nm in size) with titania or alumina cores and silica or alumina shells can be destroyed under high-pressure cryogelation (HPCG), mechnochemical activation (MCA) that also affect the structure of aggregates of nanoparticles and agglomerates of aggregates becoming more compacted. This is accompanied by changes in color from white to beige of different tints and changes in the UV–vis spectra in the 300–600 nm range, as well as changes in crystalline structure of alumina. Any treatment of ‘soft’ nanooxides affects the interfacial behavior of polar and nonpolar adsorbates. For some of them, the hysteresis loops become strongly open. Rearrangement of secondary particles affects the freezing-melting point depression. Clusterization of adsorbates bound in pores causes diminution of heat effects during phase transition (freezing, fusion). Freezing point depression and increasing melting point cause significant hysteresis freezing-melting effects for adsorbates bound to oxide nanoparticles. The study shows that complex nanooxides can be more sensitive to external actions than simple nanooxides such as silica.

Radiological hazards of alpha-contaminated waste

International Nuclear Information System (INIS)

Rodgers, J.C.

1982-01-01

The radiological hazards of alpha-contaminated wastes are discussed in this overview in terms of two components of hazard: radiobiological hazard, and radioecological hazard. Radiobiological hazard refers to human uptake of alpha-emitters by inhalation and ingestion, and the resultant dose to critical organs of the body. Radioecological hazard refers to the processes of release from buried wastes, transport in the environment, and translocation to man through the food chain. Besides detailing the sources and magnitude of hazards, this brief review identifies the uncertainties in their estimation, and implications for the regulatory process

Hazards from aircraft

International Nuclear Information System (INIS)

Grund, J.E.; Hornyik, K.

1975-01-01

The siting of nuclear power plants has created innumerable environmental concerns. Among the effects of the ''man-made environment'' one of increasing importance in recent nuclear plant siting hazards analysis has been the concern about aircraft hazards to the nuclear plant. These hazards are of concern because of the possibility that an aircraft may have a malfunction and crash either near the plant or directly into it. Such a crash could be postulated to result, because of missile and/or fire effects, in radioactive releases which would endanger the public health and safety. The majority of studies related to hazards from air traffic have been concerned with the determination of the probability associated with an aircraft striking vulnerable portions of a given plant. Other studies have focused on the structural response to such a strike. This work focuses on the problem of strike probability. 13 references

Exploring the effects of driving experience on hazard awareness and risk perception via real-time hazard identification, hazard classification, and rating tasks.

Science.gov (United States)

Borowsky, Avinoam; Oron-Gilad, Tal

2013-10-01

This study investigated the effects of driving experience on hazard awareness and risk perception skills. These topics have previously been investigated separately, yet a novel approach is suggested where hazard awareness and risk perception are examined concurrently. Young, newly qualified drivers, experienced drivers, and a group of commercial drivers, namely, taxi drivers performed three consecutive tasks: (1) observed 10 short movies of real-world driving situations and were asked to press a button each time they identified a hazardous situation; (2) observed one of three possible sub-sets of 8 movies (out of the 10 they have seen earlier) for the second time, and were asked to categorize them into an arbitrary number of clusters according to the similarity in their hazardous situation; and (3) observed the same sub-set for a third time and following each movie were asked to rate its level of hazardousness. The first task is considered a real-time identification task while the other two are performed using hindsight. During it participants' eye movements were recorded. Results showed that taxi drivers were more sensitive to hidden hazards than the other driver groups and that young-novices were the least sensitive. Young-novice drivers also relied heavily on materialized hazards in their categorization structure. In addition, it emerged that risk perception was derived from two major components: the likelihood of a crash and the severity of its outcome. Yet, the outcome was rarely considered under time pressure (i.e., in real-time hazard identification tasks). Using hindsight, when drivers were provided with the opportunity to rate the movies' hazardousness more freely (rating task) they considered both components. Otherwise, in the categorization task, they usually chose the severity of the crash outcome as their dominant criterion. Theoretical and practical implications are discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Probabilistic Tsunami Hazard Analysis

Science.gov (United States)

Thio, H. K.; Ichinose, G. A.; Somerville, P. G.; Polet, J.

2006-12-01

The recent tsunami disaster caused by the 2004 Sumatra-Andaman earthquake has focused our attention to the hazard posed by large earthquakes that occur under water, in particular subduction zone earthquakes, and the tsunamis that they generate. Even though these kinds of events are rare, the very large loss of life and material destruction caused by this earthquake warrant a significant effort towards the mitigation of the tsunami hazard. For ground motion hazard, Probabilistic Seismic Hazard Analysis (PSHA) has become a standard practice in the evaluation and mitigation of seismic hazard to populations in particular with respect to structures, infrastructure and lifelines. Its ability to condense the complexities and variability of seismic activity into a manageable set of parameters greatly facilitates the design of effective seismic resistant buildings but also the planning of infrastructure projects. Probabilistic Tsunami Hazard Analysis (PTHA) achieves the same goal for hazards posed by tsunami. There are great advantages of implementing such a method to evaluate the total risk (seismic and tsunami) to coastal communities. The method that we have developed is based on the traditional PSHA and therefore completely consistent with standard seismic practice. Because of the strong dependence of tsunami wave heights on bathymetry, we use a full waveform tsunami waveform computation in lieu of attenuation relations that are common in PSHA. By pre-computing and storing the tsunami waveforms at points along the coast generated for sets of subfaults that comprise larger earthquake faults, we can efficiently synthesize tsunami waveforms for any slip distribution on those faults by summing the individual subfault tsunami waveforms (weighted by their slip). This efficiency make it feasible to use Green's function summation in lieu of attenuation relations to provide very accurate estimates of tsunami height for probabilistic calculations, where one typically computes

Flood hazards for nuclear power plants

International Nuclear Information System (INIS)

Yen, B.C.

1988-01-01

Flooding hazards for nuclear power plants may be caused by various external geophysical events. In this paper the hydrologic hazards from flash floods, river floods and heavy rain at the plant site are considered. Depending on the mode of analysis, two types of hazard evaluation are identified: 1) design hazard which is the probability of flooding over an expected service period, and 2) operational hazard which deals with real-time forecasting of the probability of flooding of an incoming event. Hazard evaluation techniques using flood frequency analysis can only be used for type 1) design hazard. Evaluation techniques using rainfall-runoff simulation or multi-station correlation can be used for both types of hazard prediction. (orig.)

Report on the development of prices & volumes in the European fishery & aquaculture market

DEFF Research Database (Denmark)

Valle, Paul Steinar; Eliasen, Søren Qvist; Taskov, Dimitar

2016-01-01

I denne rapport giver PrimeFish-projektet et overblik over det europæiske og især EU seafood sektor i sammenhænge med global udvikling; dvs. udvikling i andre kontinenter med fokus på store varegrupper for fiskeri og akvakultur....

Literature survey of strontium-89/90 analysis

International Nuclear Information System (INIS)

Kwakman, P.J.M.

1994-08-01

At the RIVM Laboratory of Radiation Research (LSO), the determination of strontium-89/90 in grass and milk samples using fuming nitric acid is a bottle neck in the routine monitoring programme, mainly due to the use of hazardous chemicals. In recent scientific articles, a number of alternatives have been described. This report gives an overview of the latest developments in this field and compares the pros and cons of these methods. The most promising method appears to be the 'Sr-spec' method developed by EIChrom Industries. In this method, an ion-exchanger is used for sorption of cations from the sample solution and, subsequently, a crown ether on a polymer support is applied for the selective complexation of bivalent strontium ions in the presence of other interfering bivalent ions. An important advantage is that the hazardous fuming nitric acid can be omitted and that the total number of chemical separation steps can be largely reduced. The possibility of a routine application of the 'Sr-spec' method for the determination of strontium-89/90 in grass and milk at RIVM/LSO is proposed. 2 tabs., 1 appendix, 23 refs

Geomorphological hazards in Swat valley, Pakistan

International Nuclear Information System (INIS)

Usman, A.

1999-01-01

This study attempts to describe, interpret and analyze, in depth, the varied geomorphological hazards and their impacts prevailing in the swat valley locate in the northern hilly and mountainous regions of Pakistan. The hills and mountains re zones of high geomorphological activity with rapid rates of weathering, active tectonic activities, abundant precipitation, rapid runoff and heavy sediment transport. Due to the varied topography, lithology, steep slope, erodible soil, heavy winter snowfall and intensive rainfall in the spring and summer seasons, several kinds of geomorphological hazards, such as geomorphic gravitational hazards, Fluvial hazards, Glacial hazards, Geo tectonic hazards, are occurring frequently in swat valley. Amongst them, geomorphic gravitational hazards, such as rock fall rock slide, debris slide mud flow avalanches, are major hazards in mountains and hills while fluvial hazards and sedimentation are mainly confined to the alluvial plain and lowlands of the valley. The Getechtonic hazards, on the other hand, have wide spread distribution in the valley the magnitude and occurrence of each king of hazard is thus, varied according to intensity of process and physical geographic environment. This paper discusses the type distribution and damage due to the various geomorphological hazards and their reduction treatments. The study would to be of particular importance and interest to both natural and social scientists, as well as planner, environmentalists and decision-makers for successful developmental interventions in the region. (author)

Welding hazards

International Nuclear Information System (INIS)

Khan, M.A.

1992-01-01

Welding technology is advancing rapidly in the developed countries and has converted into a science. Welding involving the use of electricity include resistance welding. Welding shops are opened in residential area, which was causing safety hazards, particularly the teenagers and children who eagerly see the welding arc with their naked eyes. There are radiation hazards from ultra violet rays which irritate the skin, eye irritation. Welding arc light of such intensity could damage the eyes. (Orig./A.B.)

Relative consequences of transporting hazardous materials

International Nuclear Information System (INIS)

Fullwood, R.R.; Rhyne, W.R.; Simmons, J.A.; Reese, R.T.

1980-01-01

The objective of this paper is to discuss methods under study at Transportation Technology Center to develop a perspective on how technical measures of hazard and risk relate to perception of hazards, harm, and risks associated with transporting hazardous materials. This paper is concerned with two major aspects of the relative hazards problem. The first aspect is the analyses of the possible effects associated with exposure to hazardous materials as contained in the following two parts: outlines of possible problems and controversies that could be encountered in the evaluation and comparisons of hazards and risks; and description of the various measures of harm (hazards or dangers) and subsequent comparisons thereof. The second aspect of this paper leads into a presentation of the results of a study which had the following purposes: to develop analytical techniques for a consistent treatment of the phenomenology of the consequences of a release of hazardous materials; to reduce the number of variables in the consequence analyses by development of transportation accident scenarios which have the same meteorological conditions, demography, traffic and population densities, geographical features and other appropriate conditions and to develop consistent methods for presenting the results of studies and analyses that describe the phenomenology and compare hazards. The results of the study are intended to provide a bridge between analytical certainty and perception of the hazards involved. Understanding the differences in perception of hazards resulting from transport of various hazardous materials is fraught with difficulties in isolating the qualitative and quantitative features of the problem. By relating the quantitative impacts of material hazards under identical conditions, it is hoped that the perceived differences in material hazards can be delineated and evaluated

Seismic hazard assessment: Issues and alternatives

Science.gov (United States)

Wang, Z.

2011-01-01

Seismic hazard and risk are two very important concepts in engineering design and other policy considerations. Although seismic hazard and risk have often been used inter-changeably, they are fundamentally different. Furthermore, seismic risk is more important in engineering design and other policy considerations. Seismic hazard assessment is an effort by earth scientists to quantify seismic hazard and its associated uncertainty in time and space and to provide seismic hazard estimates for seismic risk assessment and other applications. Although seismic hazard assessment is more a scientific issue, it deserves special attention because of its significant implication to society. Two approaches, probabilistic seismic hazard analysis (PSHA) and deterministic seismic hazard analysis (DSHA), are commonly used for seismic hazard assessment. Although PSHA has been pro-claimed as the best approach for seismic hazard assessment, it is scientifically flawed (i.e., the physics and mathematics that PSHA is based on are not valid). Use of PSHA could lead to either unsafe or overly conservative engineering design or public policy, each of which has dire consequences to society. On the other hand, DSHA is a viable approach for seismic hazard assessment even though it has been labeled as unreliable. The biggest drawback of DSHA is that the temporal characteristics (i.e., earthquake frequency of occurrence and the associated uncertainty) are often neglected. An alternative, seismic hazard analysis (SHA), utilizes earthquake science and statistics directly and provides a seismic hazard estimate that can be readily used for seismic risk assessment and other applications. ?? 2010 Springer Basel AG.

The Far Ultraviolet M-dwarf Evolution Survey (FUMES): Overview and Initial Results

Science.gov (United States)

Pineda, J. Sebastian; France, Kevin; Youngblood, Allison

2018-01-01

M-dwarf stars are prime targets for exoplanet searches because of their close proximity and favorable properties for both planet detection and characterization, with current searches around these targets having already discovered several Earth-sized planets within their star’s habitable zones. However, the atmospheric characterization and potential habitability of these exoplanetary systems depends critically on the high-energy stellar radiation environment from X-rays to NUV. Strong radiation at these energies can lead to atmospheric mass loss and is a strong driver of photochemistry in planetary atmospheres. Recently, the MUSCLES Treasury Survey provided the first comprehensive assessment of the high-energy radiation field around old, planet hosting M-dwarfs. However, the habitability and potential for such exoplanetary atmospheres to develop life also depends on the evolution of the atmosphere and hence the evolution of the incident radiation field. The strong high-energy spectrum of young M-dwarfs can have devastating consequences for the potential habitability of a given system. We, thus, introduce the Far Ultraviolet M-dwarf Evolution Survey (FUMES), a new HST-STIS observing campaign targeting 10 early-mid M dwarfs with known rotation periods, including 6 targets with known ages, to assess the evolution of the FUV radiation, including Lyα, of M-dwarf stars with stellar rotation period. We present the initial results of our survey characterizing the FUV emission features of our targets and the implications of our measurements for the evolution of the entire high-energy radiation environment around M-dwarfs from youth to old age.

Evaluation of programmes for the prevention of behavioural problems and for development of social competences

DEFF Research Database (Denmark)

Knudsmoen, Hege; Holth, Per; Nissen, Poul

2006-01-01

Rapport om forskningsbaseret vurdering af programmer med henblik på reduktion af problemadfærd og udvikling af social kompetence i Norge......Rapport om forskningsbaseret vurdering af programmer med henblik på reduktion af problemadfærd og udvikling af social kompetence i Norge...

Martin Hammerich

DEFF Research Database (Denmark)

Haue, Harry

2011-01-01

Bidraget til antologien handler om Martin Hammerichs pædagogiske og didaktiske indsats i den højere skoles udvikling 1842-67.......Bidraget til antologien handler om Martin Hammerichs pædagogiske og didaktiske indsats i den højere skoles udvikling 1842-67....

At vokse op i et globaliseret medie- og forbrugersamfund

DEFF Research Database (Denmark)

Tufte, Birgitte

2013-01-01

Argumenter for, at der skal udvikles en medie- og forbrugerundervisning, der vil kvalificere elever til at fungere som kvalitetsbevidste og kritiske forbrugere.......Argumenter for, at der skal udvikles en medie- og forbrugerundervisning, der vil kvalificere elever til at fungere som kvalitetsbevidste og kritiske forbrugere....

Receptive processer og IT

DEFF Research Database (Denmark)

Ambjørn, Lone

2002-01-01

Sproglæringsteoretisk værktøj til udvikling af IT-støttede materialer og programmer inden for sproglig reception......Sproglæringsteoretisk værktøj til udvikling af IT-støttede materialer og programmer inden for sproglig reception...

Fra information til læring

DEFF Research Database (Denmark)

Antologi om perspektiver i og erfaringer med udvikling af samarbejde mellem biblioteker og uddannelser for at støtte de studerendes udvikling af studie- og informationskompetence. Artiklerne bygger på projekter under forskningsprojektet "Bibliotekerne som aktiv læringspartner - nye roller for for...

BadButik A/S

DEFF Research Database (Denmark)

Nielsen, Jørgen; Bertelsen, Niels Haldor

Rapporten omhandler udviklingen af et helt nyt forretningskoncept for levering af badeværelser. Konceptet omfatter både den tekniske og forretningsmæssige udvikling og har fokus på industriel udvikling af arbejdet på byggepladsen og i designarbejdet. Resultatet af projektet kan ses som svar på...... spørgsmålet: Hvordan ser denne virksomhed ud, og hvordan kan den udvikles? Rapporten henvender sig især til udviklingsorienterede boligorganisationer og virksomheder. Projektet er gennemført med støtte fra Nordic Innovation Centre, der i 2005 besluttede at støtte udviklingsprojekter, der specifikt tog...

21 CFR 123.6 - Hazard analysis and Hazard Analysis Critical Control Point (HACCP) plan.

Science.gov (United States)

2010-04-01

... Control Point (HACCP) plan. 123.6 Section 123.6 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Provisions § 123.6 Hazard analysis and Hazard Analysis Critical Control Point (HACCP) plan. (a) Hazard... fish or fishery product being processed in the absence of those controls. (b) The HACCP plan. Every...

Resilience to Interacting multi-natural hazards

Science.gov (United States)

Zhuo, Lu; Han, Dawei

2016-04-01

Conventional analyses of hazard assessment tend to focus on individual hazards in isolation. However, many parts of the world are usually affected by multiple natural hazards with the potential for interacting relationships. The understanding of such interactions, their impacts and the related uncertainties, are an important and topical area of research. Interacting multi-hazards may appear in different forms, including 1) CASCADING HAZARDS (a primary hazard triggering one or more secondary hazards such as an earthquake triggering landslides which may block river channels with dammed lakes and ensued floods), 2) CONCURRING HAZARDS (two or more primary hazards coinciding to trigger or exacerbate secondary hazards such as an earthquake and a rainfall event simultaneously creating landslides), and 3) ALTERING HAZARDS (a primary hazard increasing the probability of a secondary hazard occurring such as major earthquakes disturbing soil/rock materials by violent ground shaking which alter the regional patterns of landslides and debris flows in the subsequent years to come). All three types of interacting multi-hazards may occur in natural hazard prone regions, so it is important that research on hazard resilience should cover all of them. In the past decades, great progresses have been made in tackling disaster risk around the world. However, there are still many challenging issues to be solved, and the disasters over recent years have clearly demonstrated the inadequate resilience in our highly interconnected and interdependent systems. We have identified the following weaknesses and knowledge gaps in the current disaster risk management: 1) although our understanding in individual hazards has been greatly improved, there is a lack of sound knowledge about mechanisms and processes of interacting multi-hazards. Therefore, the resultant multi-hazard risk is often significantly underestimated with severe consequences. It is also poorly understood about the spatial and

Hazardous materials and waste management a guide for the professional hazards manager

CERN Document Server

Cheremisinoff, Nicholas P

1995-01-01

The management of hazardous materials and industrial wastes is complex, requiring a high degree of knowledge over very broad technical and legal subject areas. Hazardous wastes and materials are diverse, with compositions and properties that not only vary significantly between industries, but within industries, and indeed within the complexity of single facilities. Proper management not only requires an understanding of the numerous and complex regulations governing hazardous materials and waste streams, but an understanding and knowledge of the treatment, post-treatment, and waste minimizatio

Hazards in the chemical laboratory

International Nuclear Information System (INIS)

Bretherick, L.

1987-01-01

The contents of this book are: Preface; Introduction; Health and Safety at Work Act 1974; Safety Planning and Management; Fire Protection; Reactive Chemical Hazards; Chemical Hazards and Toxicology; Health Care and First Aid; Hazardous Chemicals; Precautions against Radiations; and An American View

St. Louis area earthquake hazards mapping project; seismic and liquefaction hazard maps

Science.gov (United States)

Cramer, Chris H.; Bauer, Robert A.; Chung, Jae-won; Rogers, David; Pierce, Larry; Voigt, Vicki; Mitchell, Brad; Gaunt, David; Williams, Robert; Hoffman, David; Hempen, Gregory L.; Steckel, Phyllis; Boyd, Oliver; Watkins, Connor M.; Tucker, Kathleen; McCallister, Natasha

2016-01-01

We present probabilistic and deterministic seismic and liquefaction hazard maps for the densely populated St. Louis metropolitan area that account for the expected effects of surficial geology on earthquake ground shaking. Hazard calculations were based on a map grid of 0.005°, or about every 500 m, and are thus higher in resolution than any earlier studies. To estimate ground motions at the surface of the model (e.g., site amplification), we used a new detailed near‐surface shear‐wave velocity model in a 1D equivalent‐linear response analysis. When compared with the 2014 U.S. Geological Survey (USGS) National Seismic Hazard Model, which uses a uniform firm‐rock‐site condition, the new probabilistic seismic‐hazard estimates document much more variability. Hazard levels for upland sites (consisting of bedrock and weathered bedrock overlain by loess‐covered till and drift deposits), show up to twice the ground‐motion values for peak ground acceleration (PGA), and similar ground‐motion values for 1.0 s spectral acceleration (SA). Probabilistic ground‐motion levels for lowland alluvial floodplain sites (generally the 20–40‐m‐thick modern Mississippi and Missouri River floodplain deposits overlying bedrock) exhibit up to twice the ground‐motion levels for PGA, and up to three times the ground‐motion levels for 1.0 s SA. Liquefaction probability curves were developed from available standard penetration test data assuming typical lowland and upland water table levels. A simplified liquefaction hazard map was created from the 5%‐in‐50‐year probabilistic ground‐shaking model. The liquefaction hazard ranges from low (60% of area expected to liquefy) in the lowlands. Because many transportation routes, power and gas transmission lines, and population centers exist in or on the highly susceptible lowland alluvium, these areas in the St. Louis region are at significant potential risk from seismically induced liquefaction and associated

Europa

DEFF Research Database (Denmark)

Hansen, Ole Erik

2000-01-01

Artiklen behandler, hvordan Europa blev centrum for den globale økonomiske udvikling, og hvilken rolle nationalstaterne har spillet for Europas udvikling. Derudover behandles det, hvordan den europæiske integrationsproces kan ses som et forsøg på at genskabe Europas centrale politiske og økonomis...

Didaktik,metoder, undervisningsmaterialer til Entreprenørskab, Teknologi, Velfærdsinnovation 2013

DEFF Research Database (Denmark)

Kallesøe, Hanne Kathrine; Petersen, Anne Karin; Christiansen, Anne Marie Højvang

2014-01-01

. Uddannelsesforløbet skulle udvikles og gennemføres i tæt samarbejde med Syddansk Sundhedsinnovation, IDEA samt offentlige og private virksomheder. Målet med uddannelsesforløbet var at give studerende mulighed for at udvikle tværprofessionelle, innovative, entreprenante og intraprenante kompetencer. Projektets...

Medlemsvandringer og krise i den danske aftalemodel?

DEFF Research Database (Denmark)

Høgedahl, Laust

2013-01-01

det gælder nytteorienterede og normative betonede motiver for et fagligt medlemskab pga. af disse forbunds fagforeningstype. Sidst i artiklen gives et bud på, hvilke konsekvenser denne udvikling vil få for reguleringen af det danske arbejdsmarked i fremtiden, hvis denne udvikling fortsætter....

Effect Documentation on the Agenda

DEFF Research Database (Denmark)

Konrad, Ingelise

2012-01-01

Artiklen retter sig mod behovet for at professioner udvikler kompetencer til at kunne dokumentere effekten af deres arbejde. Udgangspunktet er et projekt med en række biblioteker i Region Hovedstaden med afsæt i virkningsevaluering, prgramteori og narrative metoder. Projektets fokus er at udvikle...

Da Sherlock Holmes kom til Danmark første gang

DEFF Research Database (Denmark)

Lauridsen, Palle Schantz

2011-01-01

Præsentation og analyse af Holmes-figurens udvikling i populærkulturen med udgangspunkt i det succesfulde teaterstykke "Sherlock Holmes" fra 1901......Præsentation og analyse af Holmes-figurens udvikling i populærkulturen med udgangspunkt i det succesfulde teaterstykke "Sherlock Holmes" fra 1901...

Musiklærerkompetencer i et relationsfelt mellem pædagogik og fag

DEFF Research Database (Denmark)

Christensen, Finn Holst

2009-01-01

pædagogisk faglig viden og fag-faglig viden og muligheden for integration. På grundlag af en dobbelt transpositions-proces udvikles en didaktisk integrationsmodel. Med udgangspunkt heri diskuteres og udvikles det metodiske design for en undersøgelse af musiklæreres fagdidaktiske kompetencer i...

Airborne emissions of carcinogens and respiratory sensitizers during thermal processing of plastics.

Science.gov (United States)

Unwin, John; Coldwell, Matthew R; Keen, Chris; McAlinden, John J

2013-04-01

Thermoplastics may contain a wide range of additives and free monomers, which themselves may be hazardous substances. Laboratory studies have shown that the thermal decomposition products of common plastics can include a number of carcinogens and respiratory sensitizers, but very little information exists on the airborne contaminants generated during actual industrial processing. The aim of this work was to identify airborne emissions during thermal processing of plastics in real-life, practical applications. Static air sampling was conducted at 10 industrial premises carrying out compounding or a range of processes such as extrusion, blown film manufacture, vacuum thermoforming, injection moulding, blow moulding, and hot wire cutting. Plastics being processed included polyvinyl chloride, polythene, polypropylene, polyethylene terephthalate, and acrylonitrile-butadiene-styrene. At each site, static sampling for a wide range of contaminants was carried out at locations immediately adjacent to the prominent fume-generating processes. The monitoring data indicated the presence of few carcinogens at extremely low concentrations, all less than 1% of their respective WEL (Workplace Exposure Limit). No respiratory sensitizers were detected at any sites. The low levels of process-related fume detected show that the control strategies, which employed mainly forced mechanical general ventilation and good process temperature control, were adequate to control the risks associated with exposure to process-related fume. This substantiates the advice given in the Health and Safety Executive's information sheet No 13, 'Controlling Fume During Plastics Processing', and its broad applicability in plastics processing in general.

Hazardous solvent substitution

International Nuclear Information System (INIS)

Twitchell, K.E.

1995-01-01

This article is an overview of efforts at INEL to reduce the generation of hazardous wastes through the elimination of hazardous solvents. To aid in their efforts, a number of databases have been developed and will become a part of an Integrated Solvent Substitution Data System. This latter data system will be accessible through Internet

Modified hazard ranking system for sites with mixed radioactive and hazardous wastes. User manual

International Nuclear Information System (INIS)

Hawley, K.A.; Peloquin, R.A.; Stenner, R.D.

1986-04-01

This document describes both the original Hazard Ranking System and the modified Hazard Ranking System as they are to be used in evaluating the relative potential for uncontrolled hazardous substance facilities to cause human health or safety problems or ecological or environmental damage. Detailed instructions for using the mHRS/HRS computer code are provided, along with instructions for performing the calculations by hand. Uniform application of the ranking system will permit the DOE to identify those releases of hazardous substances that pose the greatest hazard to humans or the environment. However, the mHRS/HRS by itself cannot establish priorities for the allocation of funds for remedial action. The mHRS/HRS is a means for applying uniform technical judgment regarding the potential hazards presented by a facility relative to other facilities. It does not address the feasibility, desirability, or degree of cleanup required. Neither does it deal with the readiness or ability of a state to carry out such remedial action, as may be indicated, or to meet other conditions prescribed in CERCLA. 13 refs., 13 figs., 27 tabs

Modified hazard ranking system for sites with mixed radioactive and hazardous wastes. User manual.

Energy Technology Data Exchange (ETDEWEB)

Hawley, K.A.; Peloquin, R.A.; Stenner, R.D.

1986-04-01

This document describes both the original Hazard Ranking System and the modified Hazard Ranking System as they are to be used in evaluating the relative potential for uncontrolled hazardous substance facilities to cause human health or safety problems or ecological or environmental damage. Detailed instructions for using the mHRS/HRS computer code are provided, along with instructions for performing the calculations by hand. Uniform application of the ranking system will permit the DOE to identify those releases of hazardous substances that pose the greatest hazard to humans or the environment. However, the mHRS/HRS by itself cannot establish priorities for the allocation of funds for remedial action. The mHRS/HRS is a means for applying uniform technical judgment regarding the potential hazards presented by a facility relative to other facilities. It does not address the feasibility, desirability, or degree of cleanup required. Neither does it deal with the readiness or ability of a state to carry out such remedial action, as may be indicated, or to meet other conditions prescribed in CERCLA. 13 refs., 13 figs., 27 tabs.

Hazardous solvent substitution

International Nuclear Information System (INIS)

Twitchell, K.E.

1995-01-01

Eliminating hazardous solvents is good for the environment, worker safety, and the bottom line. However, even though we are motivated to find replacements, the big question is 'What can we use as replacements for hazardous solvents?'You, too, can find replacements for your hazardous solvents. All you have to do is search for them. Search through the vendor literature of hundreds of companies with thousands of products. Ponder the associated material safety data sheets, assuming of course that you can obtain them and, having obtained them, that you can read them. You will want to search the trade magazines and other sources for product reviews. You will want to talk to users about how well the product actually works. You may also want to check US Environmental Protection Agency (EPA) and other government reports for toxicity and other safety information. And, of course, you will want to compare the product's constituent chemicals with the many hazardous constituency lists to ensure the safe and legal use of the product in your workplace

Enhancing the quality of aged latent fingerprints developed by superglue fuming: loss and replenishment of initiator.

Science.gov (United States)

Wargacki, Stephen P; Lewis, Linda A; Dadmun, Mark D

2008-09-01

The recovery and identification of latent fingerprints from a crime scene are crucial to many investigations. The cyanoacrylate (superglue) fuming method (CFM), which develops fingerprints by growing a polymer coating over the print residue, is a powerful method but encounters severe limitations when prints are aged or exposed to harsh environmental conditions. We examine the aging process and how the changes that occur to a fingerprint residue over time influence the growth of polymer during development. We identify loss of initiator by erosion and degradation that, when coupled with a loss of water from the print residue, result in a decreased ability to polymerize ethylcyanoacrylate. Then, we present a methodology by which the ability of aged latent fingerprints to polymerize ethylcyanoacrylate is recovered. Two print enhancement agents, acetic acid and ammonia, are demonstrated to improve the growth of polymer from the print ridges by over an order of magnitude, while retaining the integrity of the print structure. Comparison between the two enhancement agents indicate that the enhancement occurs due to ridge coating by the ammonia or acetic acid and pH control of the latent print.

Radon and its hazards

International Nuclear Information System (INIS)

Chang Guilan

2002-01-01

The author describes basic physical and chemical properties of radon and the emanation, introduces methods of radon measurement, expounds the hazards of non-mine radon accumulation to the health of human being and the protection, as well as the history how the human being recognizes the hazards of radon through the specific data and examples, and finally proposes protecting measures to avoid the hazards of radon to the health of human being, and to do ecologic evaluation of environments

Industrial hazard and safety handbook

CERN Document Server

King, Ralph W

1979-01-01

Industrial Hazard and Safety Handbook (Revised Impression) describes and exposes the main hazards found in industry, with emphasis on how these hazards arise, are ignored, are identified, are eliminated, or are controlled. These hazard conditions can be due to human stresses (for example, insomnia), unsatisfactory working environments, as well as secret industrial processes. The book reviews the cost of accidents, human factors, inspections, insurance, legal aspects, planning for major emergencies, organization, and safety measures. The text discusses regulations, codes of practice, site layou

Global Landslide Hazard Distribution

Data.gov (United States)

National Aeronautics and Space Administration — Global Landslide Hazard Distribution is a 2.5 minute grid of global landslide and snow avalanche hazards based upon work of the Norwegian Geotechnical Institute...

Natural Hazards, Second Edition

Science.gov (United States)

Rouhban, Badaoui

Natural disaster loss is on the rise, and the vulnerability of the human and physical environment to the violent forces of nature is increasing. In many parts of the world, disasters caused by natural hazards such as earthquakes, floods, landslides, drought, wildfires, intense windstorms, tsunami, and volcanic eruptions have caused the loss of human lives, injury, homelessness, and the destruction of economic and social infrastructure. Over the last few years, there has been an increase in the occurrence, severity, and intensity of disasters, culminating with the devastating tsunami of 26 December 2004 in South East Asia.Natural hazards are often unexpected or uncontrollable natural events of varying magnitude. Understanding their mechanisms and assessing their distribution in time and space are necessary for refining risk mitigation measures. This second edition of Natural Hazards, (following a first edition published in 1991 by Cambridge University Press), written by Edward Bryant, associate dean of science at Wollongong University, Australia, grapples with this crucial issue, aspects of hazard prediction, and other issues. The book presents a comprehensive analysis of different categories of hazards of climatic and geological origin.

Impact of nanoclay dispersed phenol formaldehyde/fumed silica nanocomposites on physico-mechanical and thermal properties

Science.gov (United States)

Lai, Josephine Chang Hui; Rahman, Md. Rezaur; Hamdan, Sinin

2017-12-01

In this study, the physical, mechanical and thermal properties of phenol formaldehyde/fumed silica/nanoclay (PF/FS/clay) nanocomposites were investigated. PF/FS/clay nanocomposites were prepared via condensation polymerization method and the effect of different clays as compatibilizers were subsequently investigated. The properties of nanocomposites were characterized through Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA) and tensile test. FT-IR results confirmed the condensation polymerization and the formation of nanocomposites. SEM result revealed that the surface-modified clay (1.34TCN) had better compatibility with PF/FS matrix compared to surface-modified clay (1.28E), clay (1.30E) and clay (1.31PS). Besides, clay (1.34TCN)-loaded nanocomposites showed better surface morphology among all the nanocomposites. Furthermore, PF/FS/clay (1.34TCN) nanocomposite exhibited better tensile strength and modulus up to 68% due to the strong interfacial bonding between the polymer matrix and fillers. Thermal stability of PF/FS/clay (1.34TCN) nanocomposite showed the highest weight percent loss at the final degradation stage with higher activation energy. Overall, this study proved that clay (1.34TCN) was the most suitable to be introduced in PF/FS matrix.

The analysis of lightweight brick strength pressure with mixture of glass powder and silica fume

Science.gov (United States)

Nursyamsi; Liang, William

2018-03-01

Little by little the engineers research how the development of concrete that can utilize waste. In the utilization of the waste, it can be functioned as mixing material which the chemical or the physical traits of the used goods contain similarity to the mixture of concrete in general, one of them is glass powder as the substitute of cement. The glass powder that utilizes is the one that is sifted through sieve No. 200 as much as 10% of the weight of the cement. The testing specimen of the concrete brick is make of the mixture with the ratio of 1:7, then is added with the foaming agent (1:30) and silica fume (10% of the weight of the cement). Furthermore, visual examination, absorption, net weight and testing specimen compressive strength. The data analysis uses the reference of SNI 03 – 0349 – 1989 regarding Concrete Brick for the Match for the Wall. Foaming Agent is make by using modified hand drill and brace. The testing specimen uses the brick mold with the size of 40 cm x 20cm x 10 cm. Based on this research, it shows that the quality that results from brick is still qualified based on SNI 03 – 0349 – 1989.

Carbon Structure Hazard Control

Science.gov (United States)

Yoder, Tommy; Greene, Ben; Porter, Alan

2015-01-01

Carbon composite structures are widely used in virtually all advanced technology industries for a multitude of applications. The high strength-to-weight ratio and resistance to aggressive service environments make them highly desirable. Automotive, aerospace, and petroleum industries extensively use, and will continue to use, this enabling technology. As a result of this broad range of use, field and test personnel are increasingly exposed to hazards associated with these structures. No single published document exists to address the hazards and make recommendations for the hazard controls required for the different exposure possibilities from damaged structures including airborne fibers, fly, and dust. The potential for personnel exposure varies depending on the application or manipulation of the structure. The effect of exposure to carbon hazards is not limited to personnel, protection of electronics and mechanical equipment must be considered as well. The various exposure opportunities defined in this document include pre-manufacturing fly and dust, the cured structure, manufacturing/machining, post-event cleanup, and post-event test and/or evaluation. Hazard control is defined as it is applicable or applied for the specific exposure opportunity. The carbon exposure hazard includes fly, dust, fiber (cured/uncured), and matrix vapor/thermal decomposition products. By using the recommendations in this document, a high level of confidence can be assured for the protection of personnel and equipment.

75 FR 73972 - Hazardous Waste Management System; Identification and Listing of Hazardous Waste; Removal of...

Science.gov (United States)

2010-11-30

... Waste Management System; Identification and Listing of Hazardous Waste; Removal of Direct Final.... Lists of Subjects in 40 CFR Part 261 Environmental Protection, Hazardous waste, Recycling, Reporting and... follows: PART 261--IDENTIFICATION AND LISTING OF HAZARDOUS WASTE 0 1. The authority citation for part 261...

Hazardous waste: cleanup and prevention

Science.gov (United States)

Vandas, Stephen; Cronin, Nancy L.; Farrar, Frank; Serrano, Guillermo Eliezer Ávila; Yajimovich, Oscar Efraín González; Muñoz, Aurora R.; Rivera, María del C.

1996-01-01

Our lifestyles are supported by complex Industrial activities that produce many different chemicals and chemical wastes. The Industries that produce our clothing, cars, medicines, paper, food, fuels, steel, plastics, and electric components use and discard thousands of chemicals every year. At home we may use lawn chemicals, solvents, disinfectants, cleaners, and auto products to Improve our quality of life. A chemical that presents a threat or unreasonable risk to people or the environment Is a hazardous material. When a hazardous material can no longer be used, It becomes a hazardous waste. Hazardous wastes come from a variety of sources, from both present and past activities. Impacts to human health and the environment can result from Improper handling and disposal of hazardous waste.

SRL process hazards review manual

International Nuclear Information System (INIS)

1980-08-01

The principal objective of the Process Hazards Management Program is to provide a regular, systematic review of each process at the Savannah River Laboratory (SRL) to eliminate injuries and to minimize property damage resulting from process hazards of catastrophic potential. Management effort is directed, through the Du Pont Safety Program, toward those controls and practices that ensure this objective. The Process Hazards Management Program provides an additional dimension to further ensure the health and safety of employees and the public. Du Pont has concluded that an organized approach is essential to obtain an effective and efficient process hazards review. The intent of this manual is to provide guidance in creating such an organized approach to performing process hazards reviews on a continuing basis

Hydrothermal Liquefaction Treatment Hazard Analysis Report

Energy Technology Data Exchange (ETDEWEB)

Lowry, Peter P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wagner, Katie A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2016-09-12

Hazard analyses were performed to evaluate the modular hydrothermal liquefaction treatment system. The hazard assessment process was performed in 2 stages. An initial assessment utilizing Hazard Identification and Preliminary Hazards Analysis (PHA) techniques identified areas with significant or unique hazards (process safety-related hazards) that fall outside of the normal operating envelope of PNNL and warranted additional analysis. The subsequent assessment was based on a qualitative What-If analysis. The analysis was augmented, as necessary, by additional quantitative analysis for scenarios involving a release of hazardous material or energy with the potential for affecting the public. The following selected hazardous scenarios received increased attention: •Scenarios involving a release of hazardous material or energy, controls were identified in the What-If analysis table that prevent the occurrence or mitigate the effects of the release. •Scenarios with significant consequences that could impact personnel outside the immediate operations area, quantitative analyses were performed to determine the potential magnitude of the scenario. The set of “critical controls” were identified for these scenarios (see Section 4) which prevent the occurrence or mitigate the effects of the release of events with significant consequences.

Hazardous Chemicals

Centers for Disease Control (CDC) Podcasts

2007-04-10

Chemicals are a part of our daily lives, providing many products and modern conveniences. With more than three decades of experience, The Centers for Disease Control and Prevention (CDC) has been in the forefront of efforts to protect and assess people's exposure to environmental and hazardous chemicals. This report provides information about hazardous chemicals and useful tips on how to protect you and your family from harmful exposure.  Created: 4/10/2007 by CDC National Center for Environmental Health.   Date Released: 4/13/2007.

Implementering af Cuneco-standarder i byggeriets uddannelser

DEFF Research Database (Denmark)

Bertelsen, Niels Haldor; Klint, Lars; Svidt, Kjeld

, egenskaber, informationsniveauer og opmålingsregler i deres uddannelser, og hvordan de indbyrdes har udvekslet erfaringer. De har i det tværfaglige samarbejde om udvikling bl.a. haft fokus på læringsmidler, læreruddannelse, kursusindhold og praksisprojekter samt udvikling af BIM-kompetencer. Rapporten viser...

Drivsel - drift og trivsel i callcentre

DEFF Research Database (Denmark)

Møller, Niels; Wiegman, Inger-Marie; Pedersen, Jens Voxtrup

Bogen fortæller om resultaterne af et treårigt projekt om arbejdet i callcentre som blev afsluttet i 2006. Projektet ”Callcentre – udvikling af arbejdet” gennemførte udvikling af arbejdet, arbejdsorganiseringen og kompetencerne i tre store danske virksomheder Nykredit, Danske Bank og TDC, som har...

International indsats

DEFF Research Database (Denmark)

Sachs, Therese

En analyse af Beredskabsstyrelsens internationale engagement og muligheder for international indsats fremover. Forslag til struktur logistisk og materielt samt til udvikling af personel-kompetencer......En analyse af Beredskabsstyrelsens internationale engagement og muligheder for international indsats fremover. Forslag til struktur logistisk og materielt samt til udvikling af personel-kompetencer...

Formalsproglig kompetence og IT

DEFF Research Database (Denmark)

Ambjørn, Lone

2002-01-01

Sproglæringsteoretisk værktøj til udvikling af IT-støttede materialer og programmer inden for grammatisk og leksikalsk kompetence......Sproglæringsteoretisk værktøj til udvikling af IT-støttede materialer og programmer inden for grammatisk og leksikalsk kompetence...

Supermagternes sammenstød

DEFF Research Database (Denmark)

Vestenskov, David

2013-01-01

Afghanistan udgjorde i tiåret 1979-89 en brandvarm arena for en ellers fastfrosset koldkrigsrelation mellem stormagterne USA og Sovjetunionen. Den historiske udvikling i netop denne periode har på mange måder dannet grundlag for Afghanistans udvikling frem til i dag, hvor forudsætningerne...

Fremtidens landbrug bliver big business

DEFF Research Database (Denmark)

Hansen, Henning Otte

2016-01-01

Landbrugets omverdensforhold og konkurrencevilkår ændres, og det vil nødvendiggøre en udvikling i retning af “big business“, hvor landbrugene bliver endnu større, mere industrialiserede og koncentrerede. Big business bliver en dominerende udvikling i dansk landbrug - men ikke den eneste...

A Multi-Faceted Workplace Intervention For Prevention Of Low Back Pain

DEFF Research Database (Denmark)

Rasmussen, Charlotte Diana Nørregaard

til forebyggelse af ondt i ryggen samt for forebyggelse af konsekvenser af ondt i ryggen. For at udvikle indsatsen anvendte vi en systematisk tilgang (intervention mapping), som involverer arbejdspladsen i udvikling og i planlægning af indsatsen. Fra november 2012 til maj 2014 gennemførte vi et...

Transportation of Hazardous Evidentiary Material.

Energy Technology Data Exchange (ETDEWEB)

Osborn, Douglas.

2005-06-01

This document describes the specimen and transportation containers currently available for use with hazardous and infectious materials. A detailed comparison of advantages, disadvantages, and costs of the different technologies is included. Short- and long-term recommendations are also provided.3 DraftDraftDraftExecutive SummaryThe Federal Bureau of Investigation's Hazardous Materials Response Unit currently has hazardous material transport containers for shipping 1-quart paint cans and small amounts of contaminated forensic evidence, but the containers may not be able to maintain their integrity under accident conditions or for some types of hazardous materials. This report provides guidance and recommendations on the availability of packages for the safe and secure transport of evidence consisting of or contaminated with hazardous chemicals or infectious materials. Only non-bulk containers were considered because these are appropriate for transport on small aircraft. This report will addresses packaging and transportation concerns for Hazardous Classes 3, 4, 5, 6, 8, and 9 materials. If the evidence is known or suspected of belonging to one of these Hazardous Classes, it must be packaged in accordance with the provisions of 49 CFR Part 173. The anthrax scare of several years ago, and less well publicized incidents involving unknown and uncharacterized substances, has required that suspicious substances be sent to appropriate analytical laboratories for analysis and characterization. Transportation of potentially hazardous or infectious material to an appropriate analytical laboratory requires transport containers that maintain both the biological and chemical integrity of the substance in question. As a rule, only relatively small quantities will be available for analysis. Appropriate transportation packaging is needed that will maintain the integrity of the substance, will not allow biological alteration, will not react chemically with the substance being

Comparative Distributions of Hazard Modeling Analysis

Directory of Open Access Journals (Sweden)

Rana Abdul Wajid

2006-07-01

Full Text Available In this paper we present the comparison among the distributions used in hazard analysis. Simulation technique has been used to study the behavior of hazard distribution modules. The fundamentals of Hazard issues are discussed using failure criteria. We present the flexibility of the hazard modeling distribution that approaches to different distributions.

30 CFR 47.21 - Identifying hazardous chemicals.

Science.gov (United States)

2010-07-01

..., subpart Z, Toxic and Hazardous Substances. (4) American Conference of Governmental Industrial Hygienists... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Identifying hazardous chemicals. 47.21 Section... TRAINING HAZARD COMMUNICATION (HazCom) Hazard Determination § 47.21 Identifying hazardous chemicals. The...

76 FR 74709 - Hazardous Waste Management System; Identification and Listing of Hazardous Waste; Final Exclusion

Science.gov (United States)

2011-12-01

..., including any sludge, spill residue, ash, emission control dust, or leachate, remains a hazardous waste... water for use as a cleaning agent. The slop oil waste is thereby diluted and hazardous constituents are... separation sludges that are listed as hazardous wastes due to benzene, benzo(a)pyrene, chrysene, lead and...

75 FR 78918 - Hazardous Waste Management System; Identification and Listing of Hazardous Waste; Removal of...

Science.gov (United States)

2010-12-17

... and Community Right-to-Know Act FDA Food and Drug Administration HSWA Hazardous and Solid Waste...(f)), and hazardous substances (40 CFR 302.4) based solely upon the evidence that it is a potential... subsequently identified as hazardous wastes in Sec. 261.33(f) based solely on their potential for carcinogenic...

Modified Hazard Ranking System/Hazard Ranking System for sites with mixed radioactive and hazardous wastes: Software documentation

Energy Technology Data Exchange (ETDEWEB)

Stenner, R.D.; Peloquin, R.A.; Hawley, K.A.

1986-11-01

The mHRS/HRS software package was developed by the Pacific Northwest Laboratory (PNL) under contract with the Department of Energy (DOE) to provide a uniform method for DOE facilities to use in performing their Conservation Environmental Response Compensation and Liability Act (CERCLA) Phase I Modified Hazard Ranking System or Hazard Ranking System evaluations. The program is designed to remove the tedium and potential for error associated with the performing of hand calculations and the interpreting of information on tables and in reference books when performing an evaluation. The software package is designed to operate on a microcomputer (IBM PC, PC/XT, or PC/AT, or a compatible system) using either a dual floppy disk drive or a hard disk storage system. It is written in the dBASE III language and operates using the dBASE III system. Although the mHRS/HRS software package was developed for use at DOE facilities, it has direct applicability to the performing of CERCLA Phase I evaluations for any facility contaminated by hazardous waste. The software can perform evaluations using either the modified hazard ranking system methodology developed by DOE/PNL, the hazard ranking system methodology developed by EPA/MITRE Corp., or a combination of the two. This document is a companion manual to the mHRS/HRS user manual. It is intended for the programmer who must maintain the software package and for those interested in the computer implementation. This manual documents the system logic, computer programs, and data files that comprise the package. Hardware and software implementation requirements are discussed. In addition, hand calculations of three sample situations (problems) with associated computer runs used for the verification of program calculations are included.

Modified Hazard Ranking System/Hazard Ranking System for sites with mixed radioactive and hazardous wastes: Software documentation

International Nuclear Information System (INIS)

Stenner, R.D.; Peloquin, R.A.; Hawley, K.A.

1986-11-01

The mHRS/HRS software package was developed by the Pacific Northwest Laboratory (PNL) under contract with the Department of Energy (DOE) to provide a uniform method for DOE facilities to use in performing their Conservation Environmental Response Compensation and Liability Act (CERCLA) Phase I Modified Hazard Ranking System or Hazard Ranking System evaluations. The program is designed to remove the tedium and potential for error associated with the performing of hand calculations and the interpreting of information on tables and in reference books when performing an evaluation. The software package is designed to operate on a microcomputer (IBM PC, PC/XT, or PC/AT, or a compatible system) using either a dual floppy disk drive or a hard disk storage system. It is written in the dBASE III language and operates using the dBASE III system. Although the mHRS/HRS software package was developed for use at DOE facilities, it has direct applicability to the performing of CERCLA Phase I evaluations for any facility contaminated by hazardous waste. The software can perform evaluations using either the modified hazard ranking system methodology developed by DOE/PNL, the hazard ranking system methodology developed by EPA/MITRE Corp., or a combination of the two. This document is a companion manual to the mHRS/HRS user manual. It is intended for the programmer who must maintain the software package and for those interested in the computer implementation. This manual documents the system logic, computer programs, and data files that comprise the package. Hardware and software implementation requirements are discussed. In addition, hand calculations of three sample situations (problems) with associated computer runs used for the verification of program calculations are included

14 CFR 437.29 - Hazard analysis.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Hazard analysis. 437.29 Section 437.29... Documentation § 437.29 Hazard analysis. (a) An applicant must perform a hazard analysis that complies with § 437.55(a). (b) An applicant must provide to the FAA all the results of each step of the hazard analysis...

The California Hazards Institute

Science.gov (United States)

Rundle, J. B.; Kellogg, L. H.; Turcotte, D. L.

2006-12-01

California's abundant resources are linked with its natural hazards. Earthquakes, landslides, wildfires, floods, tsunamis, volcanic eruptions, severe storms, fires, and droughts afflict the state regularly. These events have the potential to become great disasters, like the San Francisco earthquake and fire of 1906, that overwhelm the capacity of society to respond. At such times, the fabric of civic life is frayed, political leadership is tested, economic losses can dwarf available resources, and full recovery can take decades. A patchwork of Federal, state and local programs are in place to address individual hazards, but California lacks effective coordination to forecast, prevent, prepare for, mitigate, respond to, and recover from, the harmful effects of natural disasters. Moreover, we do not know enough about the frequency, size, time, or locations where they may strike, nor about how the natural environment and man-made structures would respond. As California's population grows and becomes more interdependent, even moderate events have the potential to trigger catastrophes. Natural hazards need not become natural disasters if they are addressed proactively and effectively, rather than reactively. The University of California, with 10 campuses distributed across the state, has world-class faculty and students engaged in research and education in all fields of direct relevance to hazards. For that reason, the UC can become a world leader in anticipating and managing natural hazards in order to prevent loss of life and property and degradation of environmental quality. The University of California, Office of the President, has therefore established a new system-wide Multicampus Research Project, the California Hazards Institute (CHI), as a mechanism to research innovative, effective solutions for California. The CHI will build on the rich intellectual capital and expertise of the Golden State to provide the best available science, knowledge and tools for

Grønt regnskab 2002

DEFF Research Database (Denmark)

2003-01-01

Risø skal som nationallaboratorium fremme en forskningsbaseret, teknologisk udvikling, som på én gang er miljømæssigt forsvarlig og skaber velstand. Risø baserer sin forskning på at bidrage til en bæredygtig udvikling inden for energi, industrielteknologi og bioproduktion. Disse teknologiske områ...

Wave Dragon

DEFF Research Database (Denmark)

Kofoed, Jens Peter; Petersen, Anne-Louise S.

2004-01-01

Udvikling og produktion af vindmøller har været en af de største danske erhvervssucceser gennem de sidste 10 år. Nu er det næste danske bud på en vedvarende energikilde under udvikling havets bølger skal fanges, og deres energi skal tappes....

DUB-Projekt Morsø Kommune

DEFF Research Database (Denmark)

Nørgaard, Britta

Formålet med evalueringen er at dokumentere ændringer, som projektdeltagelsen har medført hos projektdeltagerne, lige som der skal udvikles anbefalinger i forhold til udvikling af god praksis for arbejdet med udsatte børn. De overordnede evalueringsspørgsmål, der bliver styrende for evalueringen,...

Uncertainty on shallow landslide hazard assessment: from field data to hazard mapping

Science.gov (United States)

Trefolini, Emanuele; Tolo, Silvia; Patelli, Eduardo; Broggi, Matteo; Disperati, Leonardo; Le Tuan, Hai

2015-04-01

Shallow landsliding that involve Hillslope Deposits (HD), the surficial soil that cover the bedrock, is an important process of erosion, transport and deposition of sediment along hillslopes. Despite Shallow landslides generally mobilize relatively small volume of material, they represent the most hazardous factor in mountain regions due to their high velocity and the common absence of warning signs. Moreover, increasing urbanization and likely climate change make shallow landslides a source of widespread risk, therefore the interest of scientific community about this process grown in the last three decades. One of the main aims of research projects involved on this topic, is to perform robust shallow landslides hazard assessment for wide areas (regional assessment), in order to support sustainable spatial planning. Currently, three main methodologies may be implemented to assess regional shallow landslides hazard: expert evaluation, probabilistic (or data mining) methods and physical models based methods. The aim of this work is evaluate the uncertainty of shallow landslides hazard assessment based on physical models taking into account spatial variables such as: geotechnical and hydrogeologic parameters as well as hillslope morphometry. To achieve this goal a wide dataset of geotechnical properties (shear strength, permeability, depth and unit weight) of HD was gathered by integrating field survey, in situ and laboratory tests. This spatial database was collected from a study area of about 350 km2 including different bedrock lithotypes and geomorphological features. The uncertainty associated to each step of the hazard assessment process (e.g. field data collection, regionalization of site specific information and numerical modelling of hillslope stability) was carefully characterized. The most appropriate probability density function (PDF) was chosen for each numerical variable and we assessed the uncertainty propagation on HD strength parameters obtained by

Occupational, social, and relationship hazards and psychological distress among low-income workers: implications of the 'inverse hazard law'.

Science.gov (United States)

Krieger, Nancy; Kaddour, Afamia; Koenen, Karestan; Kosheleva, Anna; Chen, Jarvis T; Waterman, Pamela D; Barbeau, Elizabeth M

2011-03-01

Few studies have simultaneously included exposure information on occupational hazards, relationship hazards (eg, intimate partner violence) and social hazards (eg, poverty and racial discrimination), especially among low-income multiracial/ethnic populations. A cross-sectional study (2003-2004) of 1202 workers employed at 14 worksites in the greater Boston area of Massachusetts investigated the independent and joint association of occupational, social and relationship hazards with psychological distress (K6 scale). Among this low-income cohort (45% were below the US poverty line), exposure to occupational, social and relationship hazards, per the 'inverse hazard law,' was high: 82% exposed to at least one occupational hazard, 79% to at least one social hazard, and 32% of men and 34% of women, respectively, stated they had been the perpetrator or target of intimate partner violence (IPV). Fully 15.4% had clinically significant psychological distress scores (K6 score ≥ 13). All three types of hazards, and also poverty, were independently associated with increased risk of psychological distress. In models including all three hazards, however, significant associations with psychological distress occurred among men and women for workplace abuse and high exposure to racial discrimination only; among men, for IPV; and among women, for high exposure to occupational hazards, poverty and smoking. Reckoning with the joint and embodied reality of diverse types of hazards involving how people live and work is necessary for understanding determinants of health status.

Occupational health hazards in veterinary medicine: Zoonoses and other biological hazards

Science.gov (United States)

Epp, Tasha; Waldner, Cheryl

2012-01-01

This study describes biological hazards reported by veterinarians working in western Canada obtained through a self-administered mailed questionnaire. The potential occupational hazards included as biological hazards were zoonotic disease events, exposure to rabies, injuries due to bites and scratches, and allergies. Only 16.7% (136/812) of responding veterinarians reported the occurrence of a zoonosis or exposure to rabies in the past 5 years; the most commonly reported event was ringworm. Most bites and scratches (86%) described by 586 veterinarians involved encounters with cats; 81% of the resulting 163 infections were due to cat bites or scratches. Approximately 38% of participants reported developing an allergy during their career, with 41% of the affected individuals altering the way they practiced in response to their allergy. PMID:22851775

There's Life in Hazard Trees

Science.gov (United States)

Mary Torsello; Toni McLellan

The goals of hazard tree management programs are to maximize public safety and maintain a healthy sustainable tree resource. Although hazard tree management frequently targets removal of trees or parts of trees that attract wildlife, it can take into account a diversity of tree values. With just a little extra planning, hazard tree management can be highly beneficial...

Staff technical position on investigations to identify fault displacement hazards and seismic hazards at a geologic repository

International Nuclear Information System (INIS)

McConnell, K.I.; Blackford, M.E.; Ibrahim, A.K.

1992-07-01

The purpose of this Staff Technical Position (STP) is to provide guidance to the US Department of Energy (DOE) on acceptable geologic repository investigations that can be used to identify fault displacement hazards and seismic hazards. ne staff considers that the approach this STP takes to investigations of fault displacement and seismic phenomena is appropriate for the collection of sufficient data for input to analyses of fault displacement hazards and seismic hazards, both for the preclosure and postclosure performance periods. However, detailed analyses of fault displacement and seismic data, such as those required for comprehensive assessments of repository performance, may identify the need for additional investigations. Section 2.0 of this STP describes the 10 CFR Part 60 requirements that form the basis for investigations to describe fault displacement hazards and seismic hazards at a geologic repository. Technical position statements and corresponding discussions are presented in Sections 3.0 and 4.0, respectively. Technical position topics in this STP are categorized thusly: (1) investigation considerations, (2) investigations for fault-displacement hazards, and (3) investigations for seismic hazards

Studies on the hazard potential of noble metal emissions from catalytic converters; Untersuchungen zur Frage des Gefaehrdungspotentials von katalysatorbuertigen Edelmetallemissionen (VPT 05)

Energy Technology Data Exchange (ETDEWEB)

Artelt, S [Fraunhofer-Institut fuer Toxikologie und Aerosolforschung, Hannover (Germany)

1998-12-31

Plants were exposed to engine exhaust fumes from engine test stands in order to estimate the probable level of platinum deposition near roads. [Deutsch] Zur Abschaetzung der zu erwarteten Platindeposition in der Naehe von Strassen wurden Pflanzen mit Motorabgasen, die aus Motorstandexperimenten gewonnen wurden, beaufschlagt. (orig.)

Studies on the hazard potential of noble metal emissions from catalytic converters; Untersuchungen zur Frage des Gefaehrdungspotentials von katalysatorbuertigen Edelmetallemissionen (VPT 05)

Energy Technology Data Exchange (ETDEWEB)

Artelt, S. [Fraunhofer-Institut fuer Toxikologie und Aerosolforschung, Hannover (Germany)

1997-12-31

Plants were exposed to engine exhaust fumes from engine test stands in order to estimate the probable level of platinum deposition near roads. [Deutsch] Zur Abschaetzung der zu erwarteten Platindeposition in der Naehe von Strassen wurden Pflanzen mit Motorabgasen, die aus Motorstandexperimenten gewonnen wurden, beaufschlagt. (orig.)

The Impact Hazard in the Context of Other Natural Hazards and Predictive Science

Science.gov (United States)

Chapman, C. R.

1998-09-01

The hazard due to impact of asteroids and comets has been recognized as analogous, in some ways, to other infrequent but consequential natural hazards (e.g. floods and earthquakes). Yet, until recently, astronomers and space agencies have felt no need to do what their colleagues and analogous agencies must do in order the assess, quantify, and communicate predictions to those with a practical interest in the predictions (e.g. public officials who must assess the threats, prepare for mitigation, etc.). Recent heightened public interest in the impact hazard, combined with increasing numbers of "near misses" (certain to increase as Spaceguard is implemented) requires that astronomers accept the responsibility to place their predictions and assessments in terms that may be appropriately considered. I will report on preliminary results of a multi-year GSA/NCAR study of "Prediction in the Earth Sciences: Use and Misuse in Policy Making" in which I have represented the impact hazard, while others have treated earthquakes, floods, weather, global climate change, nuclear waste disposal, acid rain, etc. The impact hazard presents an end-member example of a natural hazard, helping those dealing with more prosaic issues to learn from an extreme. On the other hand, I bring to the astronomical community some lessons long adopted in other cases: the need to understand the policy purposes of impact predictions, the need to assess potential societal impacts, the requirements to very carefully assess prediction uncertainties, considerations of potential public uses of the predictions, awareness of ethical considerations (e.g. conflicts of interest) that affect predictions and acceptance of predictions, awareness of appropriate means for publicly communicating predictions, and considerations of the international context (especially for a hazard that knows no national boundaries).

Evaluation of exhaust system for gaseous waste from the source production laboratory for radiotherapy - IPEN

Energy Technology Data Exchange (ETDEWEB)

Souza, D.C.B. de; Costa, O.L.; Feher, A.; Geraldo, B.; Carvalho, V.S.; Barbosa, N.K.O.; Vicente, R.; Zeituni, C.A.; Rostelato, M.E.C.M., E-mail: dcsouza@usp.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

2017-07-01

Exhaust systems in fume hood for chemicals and hazardous materials as radioactive substances are of great importance for the protection of the Occupationally Exposed Individual and the environment. They protect against external contaminations by particulate matter, volatile and against inhalation of radioactive gases. This work intends to evaluate the exhaustion system of the Laboratory of Production of Radioactive Sources at the Nuclear and Energy Research Institute (IPEN). (author)

29 CFR 1917.25 - Fumigants, pesticides, insecticides and hazardous preservatives (see also § 1917.2 Hazardous...

Science.gov (United States)

2010-07-01

... 29 Labor 7 2010-07-01 2010-07-01 false Fumigants, pesticides, insecticides and hazardous..., DEPARTMENT OF LABOR (CONTINUED) MARINE TERMINALS Marine Terminal Operations § 1917.25 Fumigants, pesticides... fumigants, pesticides or hazardous preservatives have created a hazardous atmosphere. These signs shall note...

Hazardous Waste Manifest System

Science.gov (United States)

EPA’s hazardous waste manifest system is designed to track hazardous waste from the time it leaves the generator facility where it was produced, until it reaches the off-site waste management facility that will store, treat, or dispose of the waste.

LAV@HAZARD: a web-GIS interface for volcanic hazard assessment

Directory of Open Access Journals (Sweden)

Giovanni Gallo

2011-12-01

Full Text Available Satellite data, radiative power of hot spots as measured with remote sensing, historical records, on site geological surveys, digital elevation model data, and simulation results together provide a massive data source to investigate the behavior of active volcanoes like Mount Etna (Sicily, Italy over recent times. The integration of these heterogeneous data into a coherent visualization framework is important for their practical exploitation. It is crucial to fill in the gap between experimental and numerical data, and the direct human perception of their meaning. Indeed, the people in charge of safety planning of an area need to be able to quickly assess hazards and other relevant issues even during critical situations. With this in mind, we developed LAV@HAZARD, a web-based geographic information system that provides an interface for the collection of all of the products coming from the LAVA project research activities. LAV@HAZARD is based on Google Maps application programming interface, a choice motivated by its ease of use and the user-friendly interactive environment it provides. In particular, the web structure consists of four modules for satellite applications (time-space evolution of hot spots, radiant flux and effusion rate, hazard map visualization, a database of ca. 30,000 lava-flow simulations, and real-time scenario forecasting by MAGFLOW on Compute Unified Device Architecture.

Udviklingen af algoritmer til at beskrive sikker kørsel på basis af data fra kørende biler

DEFF Research Database (Denmark)

Agerholm, Niels; Rasmussen, Niels Kaare Hjaltelin; Hansen, René Ramskov Lund

2011-01-01

En lang række Intelligente Transportsystemer udvikles i disse år til at hjælpe den enkelte bilist med at køre mere sikkert. En central del er omkring trafiksikkerhed, og som en del af det nordjyske ITS Platform projekt udvikles en risikolog, der beskriver hvor risikobetonet den enkelte deltagende...

Grænsefællesskaber

DEFF Research Database (Denmark)

Mørck, Line Lerche

Veje ud af marginalisering Hvordan opbygges fællesskaber på tværs af etniske og sociale forskelle? Hvordan integreres etniske minoriteter på en måde, der bygger videre på og udvikler deres ressourcer? Hvordan kan der udvikles teori, der ikke reproducerer social ulighed? Med udgangspunkt i det ?vi...

Re-conceiving the Artful in Management Development and Education

DEFF Research Database (Denmark)

2008-01-01

Et special issue med en række artikler, der beskæftiger sig med kunstneriske tilgange til læring, udvikling og forandring. Udgivelsesdato: 2008......Et special issue med en række artikler, der beskæftiger sig med kunstneriske tilgange til læring, udvikling og forandring. Udgivelsesdato: 2008...

Narrativ dokumentation

DEFF Research Database (Denmark)

Hedegaard Hansen, Janne

2009-01-01

Artiklen omhandler metoden 'narrativ dokumentation' som er en metode til dokumentation og udvikling af pædagogisk arbejde i skoler og institutioner. Metoden sætter særligt fokus på den professionelles faglige selvforståelse og dennes betydning for børn og brugeres udviklings- og læringsmuligheder...

Hazard Detection Software for Lunar Landing

Science.gov (United States)

Huertas, Andres; Johnson, Andrew E.; Werner, Robert A.; Montgomery, James F.

2011-01-01

The Autonomous Landing and Hazard Avoidance Technology (ALHAT) Project is developing a system for safe and precise manned lunar landing that involves novel sensors, but also specific algorithms. ALHAT has selected imaging LIDAR (light detection and ranging) as the sensing modality for onboard hazard detection because imaging LIDARs can rapidly generate direct measurements of the lunar surface elevation from high altitude. Then, starting with the LIDAR-based Hazard Detection and Avoidance (HDA) algorithm developed for Mars Landing, JPL has developed a mature set of HDA software for the manned lunar landing problem. Landing hazards exist everywhere on the Moon, and many of the more desirable landing sites are near the most hazardous terrain, so HDA is needed to autonomously and safely land payloads over much of the lunar surface. The HDA requirements used in the ALHAT project are to detect hazards that are 0.3 m tall or higher and slopes that are 5 or greater. Steep slopes, rocks, cliffs, and gullies are all hazards for landing and, by computing the local slope and roughness in an elevation map, all of these hazards can be detected. The algorithm in this innovation is used to measure slope and roughness hazards. In addition to detecting these hazards, the HDA capability also is able to find a safe landing site free of these hazards for a lunar lander with diameter .15 m over most of the lunar surface. This software includes an implementation of the HDA algorithm, software for generating simulated lunar terrain maps for testing, hazard detection performance analysis tools, and associated documentation. The HDA software has been deployed to Langley Research Center and integrated into the POST II Monte Carlo simulation environment. The high-fidelity Monte Carlo simulations determine the required ground spacing between LIDAR samples (ground sample distances) and the noise on the LIDAR range measurement. This simulation has also been used to determine the effect of

Hydrothermal Liquefaction Treatment Preliminary Hazard Analysis Report

Energy Technology Data Exchange (ETDEWEB)

Lowry, Peter P.; Wagner, Katie A.

2015-08-31

A preliminary hazard assessment was completed during February 2015 to evaluate the conceptual design of the modular hydrothermal liquefaction treatment system. The hazard assessment was performed in 2 stages. An initial assessment utilizing Hazard Identification and Preliminary Hazards Analysis (PHA) techniques identified areas with significant or unique hazards (process safety-related hazards) that fall outside of the normal operating envelope of PNNL and warranted additional analysis. The subsequent assessment was based on a qualitative What-If analysis. This analysis was augmented, as necessary, by additional quantitative analysis for scenarios involving a release of hazardous material or energy with the potential for affecting the public.

Preliminary hazards analysis -- vitrification process

International Nuclear Information System (INIS)

Coordes, D.; Ruggieri, M.; Russell, J.; TenBrook, W.; Yimbo, P.

1994-06-01

This paper presents a Preliminary Hazards Analysis (PHA) for mixed waste vitrification by joule heating. The purpose of performing a PHA is to establish an initial hazard categorization for a DOE nuclear facility and to identify those processes and structures which may have an impact on or be important to safety. The PHA is typically performed during and provides input to project conceptual design. The PHA is then followed by a Preliminary Safety Analysis Report (PSAR) performed during Title 1 and 2 design. The PSAR then leads to performance of the Final Safety Analysis Report performed during the facility's construction and testing. It should be completed before routine operation of the facility commences. This PHA addresses the first four chapters of the safety analysis process, in accordance with the requirements of DOE Safety Guidelines in SG 830.110. The hazards associated with vitrification processes are evaluated using standard safety analysis methods which include: identification of credible potential hazardous energy sources; identification of preventative features of the facility or system; identification of mitigative features; and analyses of credible hazards. Maximal facility inventories of radioactive and hazardous materials are postulated to evaluate worst case accident consequences. These inventories were based on DOE-STD-1027-92 guidance and the surrogate waste streams defined by Mayberry, et al. Radiological assessments indicate that a facility, depending on the radioactive material inventory, may be an exempt, Category 3, or Category 2 facility. The calculated impacts would result in no significant impact to offsite personnel or the environment. Hazardous materials assessment indicates that a Mixed Waste Vitrification facility will be a Low Hazard facility having minimal impacts to offsite personnel and the environment

Preliminary hazards analysis -- vitrification process

Energy Technology Data Exchange (ETDEWEB)

Coordes, D.; Ruggieri, M.; Russell, J.; TenBrook, W.; Yimbo, P. [Science Applications International Corp., Pleasanton, CA (United States)

1994-06-01

This paper presents a Preliminary Hazards Analysis (PHA) for mixed waste vitrification by joule heating. The purpose of performing a PHA is to establish an initial hazard categorization for a DOE nuclear facility and to identify those processes and structures which may have an impact on or be important to safety. The PHA is typically performed during and provides input to project conceptual design. The PHA is then followed by a Preliminary Safety Analysis Report (PSAR) performed during Title 1 and 2 design. The PSAR then leads to performance of the Final Safety Analysis Report performed during the facility`s construction and testing. It should be completed before routine operation of the facility commences. This PHA addresses the first four chapters of the safety analysis process, in accordance with the requirements of DOE Safety Guidelines in SG 830.110. The hazards associated with vitrification processes are evaluated using standard safety analysis methods which include: identification of credible potential hazardous energy sources; identification of preventative features of the facility or system; identification of mitigative features; and analyses of credible hazards. Maximal facility inventories of radioactive and hazardous materials are postulated to evaluate worst case accident consequences. These inventories were based on DOE-STD-1027-92 guidance and the surrogate waste streams defined by Mayberry, et al. Radiological assessments indicate that a facility, depending on the radioactive material inventory, may be an exempt, Category 3, or Category 2 facility. The calculated impacts would result in no significant impact to offsite personnel or the environment. Hazardous materials assessment indicates that a Mixed Waste Vitrification facility will be a Low Hazard facility having minimal impacts to offsite personnel and the environment.

French people addressing environmental hazards (Eser 2013)

International Nuclear Information System (INIS)

Pautard, Eric; Moreau, Sylvain; Bottin, Anne; Kraszewski, Marlene; Fretin, David; Carriere, Celine; Bird, Geoffrey

2015-07-01

This publication presents the results of a survey, conducted towards the end of 2013, of 4,700 people resident in metropolitan France and its 'departements d'outre-mer' (DOM - overseas departments). The aim of the survey was to ascertain how French people perceive natural hazards (flooding, earthquakes, climate events, cyclones, etc.) and technological hazards (industrial and nuclear) to which they may be exposed. Questioned as to whether or not they felt exposed to one or several environmental hazards in their place of residence, French people's answers varied somewhat depending on the hazard invoked and place of residence. A strong feeling of exposure was expressed most frequently in the DOM. Respondents in both metropolitan France and DOM think that atmospheric pollution is a significant hazard (56%) but their opinions diverge partially where other hazards are concerned. Natural hazards (earthquakes and flooding) are cited most frequently overseas, whereas technological hazards (industrial and nuclear) are primarily metropolitan concerns. Climate change related hazards are seen as a threat by 56% of overseas respondents and by 42% in the mother country. In general, one-third of French people think that they are exposed to more than two environmental hazards. Unlike the younger members of the population, only one-quarter of respondents of 65 years of age or over felt exposed to three or more hazards. From municipal level databases providing information on exposure to flooding and technological and climate-related hazards, the survey indicates that a large majority of respondents living in these municipalities either do not feel at risk from existing hazards or feel that the risk is low (see figure below). It is in the area of climate-related hazards that awareness of threat seems to be highest in France, and more particularly in the DOM. In the face of the flooding that could affect them, overseas populations are more aware of this natural

Seismic hazard assessment of Iran

Directory of Open Access Journals (Sweden)

M. Ghafory-Ashtiany

1999-06-01

Full Text Available The development of the new seismic hazard map of Iran is based on probabilistic seismic hazard computation using the historical earthquakes data, geology, tectonics, fault activity and seismic source models in Iran. These maps have been prepared to indicate the earthquake hazard of Iran in the form of iso-acceleration contour lines, and seismic hazard zoning, by using current probabilistic procedures. They display the probabilistic estimates of Peak Ground Acceleration (PGA for the return periods of 75 and 475 years. The maps have been divided into intervals of 0.25 degrees in both latitudinal and longitudinal directions to calculate the peak ground acceleration values at each grid point and draw the seismic hazard curves. The results presented in this study will provide the basis for the preparation of seismic risk maps, the estimation of earthquake insurance premiums, and the preliminary site evaluation of critical facilities.

Influence of silica fume on mechanical and physical properties of recycled aggregate concrete

Directory of Open Access Journals (Sweden)

Özgür Çakır

2015-08-01

Full Text Available Several studies related to sustainable concrete construction have encouraged development of composite binders, involving Portland cement, industrial by-products, and concrete mixes with partial replacement of natural aggregate with recycled aggregate. In this paper, the effects of incorporating silica fume (SF in the concrete mix design to improve the quality of recycled aggregates in concrete are presented. Portland cement was replaced with SF at 0%, 5% and 10%. Specimens were manufactured by replacing natural aggregates with recycled aggregates. Two size fractions (4/12 mm and 8/22 mm as recycled aggregates were used and four series of concrete mixtures were produced. In all concrete mixtures, a constant water/binder ratio at 0.50 was used and concrete mixtures with a target initial slump of S4 class (16–21 cm were prepared. Concrete properties were evaluated by means of compressive strength, tensile splitting strength, water absorption and ultrasonic pulse velocity and it was found that, using 10% SF as a cement replacement for recycled aggregate concretes enhanced the mechanical and physical properties of concrete. At all the test ages the tensile splitting strength gain of the natural aggregate concrete mixture (NA with and without SF was higher than that of the recycled concrete mixtures. Continuous and significant improvement in the tensile splitting strength of recycled aggregate concretes incorporating SF was observed. Similar to compressive strength test results, concrete incorporating 10% SF and containing 4/12 mm fraction recycled aggregates showed better performance among recycled aggregate concretes.

Identification of Aircraft Hazards

International Nuclear Information System (INIS)

K. Ashley

2006-01-01

Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2005 [DIRS 174235], Section 6.4.1). That determination was conservatively based upon limited knowledge of flight data in the area of concern and upon crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a monitored geologic repository (MGR) at Yucca Mountain, using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987 [DIRS 103124], Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. The intended use of this report is to provide inputs for further screening and analysis of identified aircraft hazards based upon the criteria that apply to Category 1 and Category 2 event sequence analyses as defined in 10 CFR 63.2 [DIRS 176544] (Section 4). The scope of this report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the repository at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (Section 7)

75 FR 58346 - Hazardous Waste Management System; Identification and Listing of Hazardous Waste

Science.gov (United States)

2010-09-24

... Waste Management System; Identification and Listing of Hazardous Waste AGENCY: Environmental Protection... Chemical Company-Texas Operations (Eastman) to exclude (or delist) certain solid wastes generated by its Longview, Texas, facility from the lists of hazardous wastes. EPA used the Delisting Risk Assessment...

Integrating Volcanic Hazard Data in a Systematic Approach to Develop Volcanic Hazard Maps in the Lesser Antilles

Directory of Open Access Journals (Sweden)

Jan M. Lindsay

2018-04-01

Full Text Available We report on the process of generating the first suite of integrated volcanic hazard zonation maps for the islands of Dominica, Grenada (including Kick ‘em Jenny and Ronde/Caille, Nevis, Saba, St. Eustatius, St. Kitts, Saint Lucia, and St Vincent in the Lesser Antilles. We developed a systematic approach that accommodated the range in prior knowledge of the volcanoes in the region. A first-order hazard assessment for each island was used to develop one or more scenario(s of likely future activity, for which scenario-based hazard maps were generated. For the most-likely scenario on each island we also produced a poster-sized integrated volcanic hazard zonation map, which combined the individual hazardous phenomena depicted in the scenario-based hazard maps into integrated hazard zones. We document the philosophy behind the generation of this suite of maps, and the method by which hazard information was combined to create integrated hazard zonation maps, and illustrate our approach through a case study of St. Vincent. We also outline some of the challenges we faced using this approach, and the lessons we have learned by observing how stakeholders have interacted with the maps over the past ~10 years. Based on our experience, we recommend that future map makers involve stakeholders in the entire map generation process, especially when making design choices such as type of base map, use of colour and gradational boundaries, and indeed what to depict on the map. We also recommend careful consideration of how to evaluate and depict offshore hazard of island volcanoes, and recommend computer-assisted modelling of all phenomena to generate more realistic hazard footprints. Finally, although our systematic approach to integrating individual hazard data into zones generally worked well, we suggest that a better approach might be to treat the integration of hazards on a case-by-case basis to ensure the final product meets map users' needs. We hope that

Integration of chemical scrubber with sodium hypochlorite and surfactant for removal of hydrocarbons in cooking oil fume

International Nuclear Information System (INIS)

Cheng, Hsin-Han; Hsieh, Chu-Chin

2010-01-01

There are many types of technologies to control cooking oil fumes (COFs), but current typical technologies, such as electrostatic precipitator, conventional scrubber, catalyst, or condenser, are unable to efficiently remove the odorous materials present in COFs which are the primary cause of odor-complaint cases. There is also a lack of information about using sodium hypochlorite (NaOCl) and surfactants to remove contaminants in COFs, and previous studies lack on-site investigations in restaurants. This study presents a chemical scrubber integrated with an automatic control system (ACS) to treat hydrocarbons (HCs) in COFs, and to monitor non-methane HCs (NMHC) and odor as indicators for its efficiency evaluation. The chemical scrubber effectively treats hydrophobic substances in COFs by combining surfactant and NaOCl under optimal operational conditions with NHMC removal efficiency as high as 85%. The mass transfer coefficient (K L a) of NMHC was enhanced by 50% under the NaOCl and surfactant conditions, as compared to typical wet scrubber. Further, this study establishes the fuzzy equations of the ACS, including the relationship between the removal efficiency and K L a, liquid/gas ratio, pH and C NaOCl .

Integration of chemical scrubber with sodium hypochlorite and surfactant for removal of hydrocarbons in cooking oil fume

Energy Technology Data Exchange (ETDEWEB)

Cheng, Hsin-Han [Graduate School of Engineering Science and Technology, National Yunlin University of Science and Technology, Touliu, Yunlin, Taiwan (China); Hsieh, Chu-Chin, E-mail: hsiehcc@yuntech.edu.tw [Department of Environmental and Safety Engineering, National Yunlin University of Science and Technology, Touliu, Yunlin, Taiwan (China)

2010-10-15

There are many types of technologies to control cooking oil fumes (COFs), but current typical technologies, such as electrostatic precipitator, conventional scrubber, catalyst, or condenser, are unable to efficiently remove the odorous materials present in COFs which are the primary cause of odor-complaint cases. There is also a lack of information about using sodium hypochlorite (NaOCl) and surfactants to remove contaminants in COFs, and previous studies lack on-site investigations in restaurants. This study presents a chemical scrubber integrated with an automatic control system (ACS) to treat hydrocarbons (HCs) in COFs, and to monitor non-methane HCs (NMHC) and odor as indicators for its efficiency evaluation. The chemical scrubber effectively treats hydrophobic substances in COFs by combining surfactant and NaOCl under optimal operational conditions with NHMC removal efficiency as high as 85%. The mass transfer coefficient (K{sub L}a) of NMHC was enhanced by 50% under the NaOCl and surfactant conditions, as compared to typical wet scrubber. Further, this study establishes the fuzzy equations of the ACS, including the relationship between the removal efficiency and K{sub L}a, liquid/gas ratio, pH and C{sub NaOCl}.

Using hazard maps to identify and eliminate workplace hazards: a union-led health and safety training program.

Science.gov (United States)

Anderson, Joe; Collins, Michele; Devlin, John; Renner, Paul

2012-01-01

The Institute for Sustainable Work and Environment and the Utility Workers Union of America worked with a professional evaluator to design, implement, and evaluate the results of a union-led system of safety-based hazard identification program that trained workers to use hazard maps to identify workplace hazards and target them for elimination. The evaluation documented program implementation and impact using data collected from both qualitative interviews and an on-line survey from worker trainers, plant managers, and health and safety staff. Managers and workers reported that not only were many dangerous hazards eliminated as a result of hazard mapping, some of which were long-standing, difficult-to-resolve issues, but the evaluation also documented improved communication between union members and management that both workers and managers agreed resulted in better, more sustainable hazard elimination.

Risøs årsplan 2005

DEFF Research Database (Denmark)

Forskningscenter Risø, Roskilde

2005-01-01

Årsplanen fastlægger rammerne for Forskningscenter Risøs virksomhed i 2005. Risø hører under Ministeriet for Videnskab, Teknologi og Udvikling og udfører naturvidenskabelig og teknisk-videnskabelig forskning. Formålet er at fremme en værdiskabende ogmiljømæssigt forsvarlig teknologisk udvikling i...

Risøs årsplan 2004

DEFF Research Database (Denmark)

Forskningscenter Risø, Roskilde

2003-01-01

Årsplanen fastlægger rammerne for Forskningscenter Risøs virksomhed i 2004. Risø hører under Ministeriet for Videnskab, Teknologi og Udvikling og udfører naturvidenskabelig og teknisk-videnskabelig forskning. Formålet er at fremme en værdiskabende ogmiljømæssigt forsvarlig teknologisk udvikling i...

Evaluering af naturfaglige kompetencer

DEFF Research Database (Denmark)

Dolin, Jens; Nielsen, Jan Alexis; Tidemand, Sofie

2017-01-01

Artiklen skitserer kort de sidste 40-50 års udvikling i naturfagene op til det nuværende fokus på undersøgelsesbaseret undervisning og udvikling af kompetencer. Den påpeger hvorledes mange traditionelle evalueringsformer, især brugt ved eksamen, ikke er i stand til at indfange de ønskede kompeten...

equitytools.eu

DEFF Research Database (Denmark)

Højer-Pedersen, Lasse; Kruse, Ane

2013-01-01

Valg af materiale/medie/form: Hjemmeside Valg af arbejdsform: Udvikling og opsætning Begrundelse for valg af materiale/medie/form/arbejdsform: Målgruppens præference......Valg af materiale/medie/form: Hjemmeside Valg af arbejdsform: Udvikling og opsætning Begrundelse for valg af materiale/medie/form/arbejdsform: Målgruppens præference...

Callcenterkonference 7.-8. marts 2006

DEFF Research Database (Denmark)

Pedersen, Merete

2005-01-01

På konferencen præsenteres resultaterne af et 3-årigt EU-projekt om udvikling af arbejdet i callcentre. Over 700 medarbejdere i 3 store virksomheder har deltaget i projektet. Projektets mål har været at udvikle nye koncepter for kompetence og organisation i callcentre. Der har samtidig været foku...

Risøs årsplan 2003

DEFF Research Database (Denmark)

Forskningscenter Risø, Roskilde

2002-01-01

Årsplanen fastlægger rammerne for Forskningscenter Risøs virksomhed i 2003. Risø hører under Ministeriet for Videnskab, Teknologi og Udvikling og udfører naturvidenskabelig og teknisk-videnskabelig forskning. Formålet er at fremme en værdiskabende ogmiljømæssigt forsvarlig teknologisk udvikling i...

16 CFR 1500.5 - Hazardous mixtures.

Science.gov (United States)

2010-01-01

..., flammable, sensitizing, or pressure-generating properties of a substance from what is known about its... Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS HAZARDOUS SUBSTANCES AND ARTICLES; ADMINISTRATION AND ENFORCEMENT REGULATIONS § 1500.5 Hazardous mixtures...