scholarly journals Evaluation of filtering facepiece respirators using chemical decontamination methods

2021 ◽  
Vol 1109 (1) ◽  
pp. 012063
Author(s):  
Baderin Osman ◽  
Haalah Mahmud ◽  
Hussin Mamat
2008 ◽  
Vol 59 (9) ◽  
Author(s):  
Eugenia Pantru ◽  
Gheorghit Jinescu ◽  
Rozalia R�dulescu ◽  
Antoneta Filcenco Olteanu ◽  
Cosmin Jinescu

This paper presents an intensive procedure used for the decontamination of the soils, which were radioactively contaminated by uranium, due to the occurrence of some antropic accidents, in order to limit the area�s pollution. The procedure used for the chemical decontamination of the polluted soils was the washing one and the decontamination degree is comparatively presented depending on the ultrasounds� presence and absence. The lab testes were performed on five types of soils , which were characterized from the granulometric, structural and chemical composition viewpoint, all these aspects represent the main factors, which determine the applied decontamination procedure�s limits and performances correlated with its utilization costs. The decontamination procedure�s kinetics for each type of soils was analyzed, using successively three different types of reagents (water, 0.1 M sulphuric acid solution and chloro-sodic solution � 100 g/L sodium chloride + 10 g/L sodium carbonate in water) for a solid to liquid ratio of 1:2, during 2 h, at a temperature of 20oC in a mechanic stirring system respectively in ultrasounds field. It was observed that the decontamination degree increases with up to 15-20% in case of the ultrasound field utilization comparing to the first case.


2021 ◽  
Vol 111 ◽  
pp. 117-124
Author(s):  
P. Kumkrong ◽  
L. Scoles ◽  
Y. Brunet ◽  
S. Baker ◽  
P.H.J. Mercier ◽  
...  

2013 ◽  
Vol 8 (1) ◽  
pp. 155892501300800 ◽  
Author(s):  
Utkarsh Sata ◽  
Eugene Wilusz ◽  
Steve Mlynarek ◽  
Gopal Coimbatore ◽  
Ronald Kendall ◽  
...  

Because of the current threat of toxic chemicals and chemical warfare agents, personal protection is important for soldiers and first responders, as well as the civilian population. This paper describes the development of a cotton non-particulate nonwoven composite fabric and the evaluation of its adsorption capability for protection against toxic chemical ingress which can be harmful or lethal. In addition, this paper focuses on the evaluation of toxic chemical adsorption capabilities of various chemical protective substrates that have the potential to be used in military applications. The development of a three-layered cotton based decontamination wipe and its adsorption of 0.1 % w/v pinacolyl methylphosphonate in butanol, is presented. Adsorption is quantified using a modified gravimetric procedure developed using a thermogravimetric analyzer. The results demonstrate the adsorption performance of a new cotton-based, non-particulate flexible composite that has a high potential to be used as a portable decontamination wipe. This research is unique in the area of individual protection and addresses the requirements of the U.S. Department of Defense (DoD) for seeking and evaluating highly efficient, non-particulate, and skin-friendly materials that provide necessary chemical protection while minimizing any discomfort or irritation.


Author(s):  
Johannes Fachinger ◽  
Heiko Barnert ◽  
Alexander P. Kummer ◽  
Guido Caspary ◽  
Manuel Seubert ◽  
...  

Pebble Bed HTGR’s like the AVR in Ju¨lich have the advantage of continuous fuelling. However the multiple passes of the fuel pebbles through the core have the disadvantage that the pebble’s movement through the fuelling system and the core produces graphite dust. This dust is transported from the core to other parts of the primary circuit and deposits on components. Although previous experiments performed during AVR operation have given some insight into the dust particle size and activity, there is little information on the behaviour of the dust that was deposited in the system. The decommissioning of the AVR has provided the opportunity to sample and characterise such dust from a number of components and gauge the adhesion strength. From the side of PBMR Pty Ltd this opportunity is considered important to enhance the knowledge about dust characteristics before the PBMR Demonstration Power Plant (DPP) is operational and able to produce specific plant information through sampling and analysis. AVR GmbH has provided a number of pipes and joints for investigation of loose and bound dust. Phase 1 of the analysis was used to determine the best techniques to be used on larger items. No measurable loose dust could be collected. Thereupon rings were cut from a T-section and subdivided into eight segments. The surface of the untreated segments were photographed and documented by optical microscopy, the dose rates were measured and gamma-spectrometry performed. Following this a mechanical or chemical decontamination was carried out to remove and isolate the bound dust. The average isolated dust amount was about 2 mg/cm2. Both decontamination processes indicates a strong bonding of the dust surface layer. In the case of mechanical decontamination about 60% and by chemical decontamination about 95% of the radionuclide inventory could be removed. The contribution of removed metal needs to be investigated in more detail. The median number related particle size measured by optical microscopy was found to be in the range of 0.2 to 0.7 μm whereas the median weight related size is in the range of 0.8 to 1.5 μm. The initial results indicate that this dust sticks very strongly to the pipe surface. Phase 2 will concentrate on longer pieces of piping where hopefully more loose dust can be obtained and analysed. If the same strong bonding is observed the reason for this phenomenon needs to be explained and perhaps tested with non-active dust.


1963 ◽  
Author(s):  
T.W. Hauff ◽  
H.F. Jensen ◽  
R.H. Smith

RSBO ◽  
2018 ◽  
Vol 1 (4) ◽  
pp. 234
Author(s):  
Marina Samara Baechtold ◽  
Aline Rocha Miquelissa ◽  
Viviane Rozeira Crivellaro ◽  
Rafaela Scariot ◽  
João César Zielak ◽  
...  

Introduction: With the increase of implant-supported rehabilitation, the cases of patients with peri-implantitis become more frequent. Objective: To report the treatment of peri-implantitis by associating techniques of surface decontamination and particulate bone graft. Case report: The treatment was carried through curettage of the granulation tissue, mechanical bone decontamination withbicarbonate jet, chemical decontamination with tetracycline solution, and particulate graft in the place of the bone defect. Conclusion: After 45 postoperative days, the peri-implant tissues were health without inflammation. After 6 postoperative months, the bone defect was repaired.


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