Database : MEDLINE
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[PMID]: 29364986
[Au] Autor:Li Y; Shuai J; Xu K
[Ad] Address:Department of Mechanical and Transportation Engineering, China University of Petroleum-Beijing, Beijing, China.
[Ti] Title:Investigation on size tolerance of pore defect of girth weld pipe.
[So] Source:PLoS One;13(1):e0191575, 2018.
[Is] ISSN:1932-6203
[Cp] Country of publication:United States
[La] Language:eng
[Ab] Abstract:Welding quality control is an important parameter for safe operation of oil and gas pipes, especially for high-strength steel pipes. Size control of welding defect is a bottleneck problem for current pipe construction. As a key part of construction procedure for butt-welding of pipes, pore defects in girth weld is difficult to ignore. A three-dimensional non-linear finite element numerical model is established to study applicability of size control indices based on groove shape and softening phenomenon of material in heat-affected zone of practical pipe girth weld. Taking design criteria of pipe as the basis, basic tensile, extremely tensile and extremely compressive loading conditions are determined for pipe stress analysis, and failure criteria based on flow stress is employed to perform stress analysis for pipe girth weld with pore defect. Results show that pipe girth welding stresses of pores at various radial locations are similar. Whereas, stress for pores of different sharpness varied significantly. Besides, tolerance capability of API 5L X90 grade pipe to pore defect of girth weld is lower than that of API 5L X80 grade pipe, and size control index of 3 mm related to pore defect in current standards is applicable to API 5L X80 and X90 grade girth welded pipes with radially non-sharp pore defects.
[Mh] MeSH terms primary: Welding
[Mh] MeSH terms secundary: Models, Theoretical
Quality Control
[Pt] Publication type:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Em] Entry month:1803
[Cu] Class update date: 180309
[Lr] Last revision date:180309
[Js] Journal subset:IM
[Da] Date of entry for processing:180125
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0191575

  2 / 3995 MEDLINE  
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[PMID]: 29519024
[Au] Autor:Zhang G; Bai J; Zhao W; Zhou K; Cheng G
[Ti] Title:Interface modification based ultrashort laser microwelding between SiC and fused silica.
[So] Source:Opt Express;25(3):1702-1709, 2017 Feb 06.
[Is] ISSN:1094-4087
[Cp] Country of publication:United States
[La] Language:eng
[Ab] Abstract:It is a big challenge to weld two materials with large differences in coefficients of thermal expansion and melting points. Here we report that the welding between fused silica (softening point, 1720°C) and SiC wafer (melting point, 3100°C) is achieved with a near infrared femtosecond laser at 800 nm. Elements are observed to have a spatial distribution gradient within the cross section of welding line, revealing that mixing and inter-diffusion of substances have occurred during laser irradiation. This is attributed to the femtosecond laser induced local phase transition and volume expansion. Through optimizing the welding parameters, pulse energy and interval of the welding lines, a shear joining strength as high as 15.1 MPa is achieved. In addition, the influence mechanism of the laser ablation on welding quality of the sample without pre-optical contact is carefully studied by measuring the laser induced interface modification.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1803
[Cu] Class update date: 180309
[Lr] Last revision date:180309
[St] Status:In-Process
[do] DOI:10.1364/OE.25.001702

  3 / 3995 MEDLINE  
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[PMID]: 29444199
[Au] Autor:Pesch B; Lehnert M; Weiss T; Kendzia B; Menne E; Lotz A; Heinze E; Behrens T; Gabriel S; Schneider W; Brüning T
[Ad] Address:Center of Epidemiology, Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr-Universität Bochum (IPA), Bürkle-de-la-Camp-Platz, Bochum, Germany.
[Ti] Title:Exposure to hexavalent chromium in welders: Results of the WELDOX II field study.
[So] Source:Ann Work Expo Health;, 2018 Feb 12.
[Is] ISSN:2398-7316
[Cp] Country of publication:England
[La] Language:eng
[Ab] Abstract:Objectives: Exposure to hexavalent chromium (Cr(VI)) has been primarily studied in chromate production. Here, we measured personal exposure to respirable Cr(VI) together with airborne and urinary Cr and Ni in welders to explore levels and associations between various measures of exposure. Methods : Shift concentrations of Cr(VI), Cr, and Ni were measured in respirable welding fumes in 50 men who used either gas metal arc welding (GMAW) (n = 24) or tungsten inert gas welding (TIG) (n = 19) as their major technique. Cr and Ni were determined in pre- and post-shift urine samples. Concentrations below the limit of quantification (LOQ) were multiply imputed. Spearman correlation coefficients (rs) were calculated with 95% confidence intervals (CIs) to explore associations between the exposure variables, and regression models were applied to estimate the effect of the parent metal on the urinary concentration. Results : Regarding the respirable Cr(VI), 62% of the measurements were below the LOQ, the 75th percentile was 0.50 µg m-3, and 8 out of 50 (16%) welders exceeded 1 µg m-3. The highest shift concentration that occurred as a result of shielded metal arc welding (SMAW) was 180 µg m-3. The Cr(VI) content in total Cr ranged from 4 to 82% (median 20%), although the concentration correlated with total Cr (rs 0.55, 95% CI 0.46; 0.64). The correlation between Cr(VI) and Ni was weaker (rs 0.42, 95% CI 0.34; 0.51) than that between total Cr and Ni in welding fumes (rs 0.83, 95% CI 0.74; 0.92). Both Cr(VI) and total Cr influenced the urinary Cr concentrations in post-shift samples (P = 0.0008 and P ≤ 0.0001, respectively). The airborne shift exposure was a weaker determinant than the Cr content in pre-shift urine samples, which strongly correlated with post-shift urinary Cr (rs 0.78, 95% CI 0.69; 0.87). Conclusions : The Cr(VI) content in total Cr varied considerably in welding fumes. The majority of welders using GMAW or TIG presented with shift concentrations of respirable Cr(VI) below 1 µg m-3. However, very high Cr(VI) concentrations may occur, for example in SMAW. The urinary concentration of total Cr, cannot be used to precisely determine the shift concentration of respirable Cr(VI) in welders.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1802
[Cu] Class update date: 180308
[Lr] Last revision date:180308
[St] Status:Publisher
[do] DOI:10.1093/annweh/wxy004

  4 / 3995 MEDLINE  
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[PMID]: 29505990
[Au] Autor:Naderizadeh S; Athanassiou A; Bayer IS
[Ad] Address:Smart Materials, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy; Dipartimento di Informatica Bioingegneria, Robotica e Ingegneria dei Sistemi (DIBRIS), Universita Degli Studi di Genova, Via All'Opera Pia 13, 16145 Genova, Italy.
[Ti] Title:Interfacing superhydrophobic silica nanoparticle films with graphene and thermoplastic polyurethane for wear/abrasion resistance.
[So] Source:J Colloid Interface Sci;519:285-295, 2018 Feb 24.
[Is] ISSN:1095-7103
[Cp] Country of publication:United States
[La] Language:eng
[Ab] Abstract:HYPOTHESIS: Nanoparticle films are one of the most suitable platforms for obtaining sub-micrometer and nanometer dual-scale surface texture required for liquid repellency. The assembly of superhydrophobic nanoparticles into conformal and strongly adherent films having abrasion-induced wear resistance still poses a significant challenge. Various techniques have been developed over the years to render nanoparticle films with good liquid repellent properties and transparency. However, forming abrasion resistant superhydrophobic nanoparticle films on hard surfaces is challenging. One possibility is to partially embed or weld nanoparticles in thin thermoplastic primers applied over metals. EXPERIMENTS: Hexamethyldisilazane-functionalized fumed silica nanoparticle films spray deposited on aluminum surfaces were rendered abrasion resistant by thermally welding them into thermoplastic polyurethane (TPU) primer applied a priori over aluminum. Different solvents, nanoparticle concentrations and annealing temperatures were studied to optimize nanoparticle film morphology and hydrophobicity. FINDINGS: Thermal annealing at 150 °C enhanced stability and wear resistance of nanoparticle films. A thin thermal interface layer of graphene nanoplatelets (GnPs) between the primer and the nanoparticle film significantly improved superhydrophobic wear resistance after annealing. As such, superhydrophobic nanocomposite films with the GnPs thermal interface layer displayed superior abrasion-induced wear resistance under 20 kPa compared to films having no GnPs-based thermal interface.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1803
[Cu] Class update date: 180305
[Lr] Last revision date:180305
[St] Status:Publisher

  5 / 3995 MEDLINE  
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[PMID]: 29494296
[Au] Autor:Koh DH; Lee SW; Ye BJ; Kim JI
[Ad] Address:a Department of Occupational Environmental Medicine , International St. Mary's Hospital, Catholic Kwandong University , Incheon , Korea.
[Ti] Title:Grouping schemes of welding fume exposure in shipyard welders.
[So] Source:J Occup Environ Hyg;:0, 2018 Mar 01.
[Is] ISSN:1545-9632
[Cp] Country of publication:England
[La] Language:eng
[Ab] Abstract:Welding fume exposure can increase the risk of chronic obstructive pulmonary disease (COPD). The aim of this study was to evaluate the optimal grouping schemes of welding fume exposure in shipyard welders for future accurate examination of the association between welding fume exposure and COPD. Industrial hygiene records, including welding fume measurements between 2002 and 2009 were collected from a shipyard. A total of 2,360 personal welding fume measurements was compiled with a geometric mean of 1.66 mg/m and a geometric standard deviation of 4.02. Welding jobs were categorized into eight groups. There were nine working areas. To obtain the optimal grouping scheme, various grouping schemes were created using job, area, and job*area combination. To compare various grouping schemes, contrast and precision were calculated for each grouping scheme. For all measurement data, group mean ranking method created by ranking geometric means of the job*area combination into three groups (group mean ranking method) showed the best contrast and precision values among various grouping schemes, followed by grouping based on the job. For a subset of the data excluding job*area combinations with less than 10 measurements, grouping based on the job showed greater contrast than group mean ranking method, while for other subsets, including only repeated measurement data or further excluding job*area combinations with less than 10 measurements from the repeated measurement subset, group mean ranking method showed greater contrast than grouping based on the job. Our results showed that group mean ranking or grouping based on the job could be a candidate for the optimal grouping schemes in this shipyard. Our efforts for optimal grouping scheme may aid future cohort study to elucidate the association between welding fume exposure and COPD.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1803
[Cu] Class update date: 180301
[Lr] Last revision date:180301
[St] Status:Publisher
[do] DOI:10.1080/15459624.2018.1447115

  6 / 3995 MEDLINE  
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[PMID]: 29489811
[Au] Autor:Ding P; Ruchkina M; Liu Y; Alden M; Bood J
[Ti] Title:Femtosecond two-photon-excited backward lasing of atomic hydrogen in a flame.
[So] Source:Opt Lett;43(5):1183-1186, 2018 Mar 01.
[Is] ISSN:1539-4794
[Cp] Country of publication:United States
[La] Language:eng
[Ab] Abstract:We report on an observation of bi-directional 656 nm lasing action of atomic hydrogen in a premixed CH /air flame induced by resonant femtosecond 205 nm two-photon excitation. In particular, the backward-propagating lasing pulse is characterized in the spatial and temporal domains for the sake of a single-ended diagnostic. Its picosecond-scale duration and smooth temporal profile enable spatially resolved detection of hydrogen atoms in the millimeter range, which is successfully demonstrated using two narrow welding flames.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1803
[Cu] Class update date: 180228
[Lr] Last revision date:180228
[St] Status:In-Process
[do] DOI:10.1364/OL.43.001183

  7 / 3995 MEDLINE  
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[PMID]: 29471427
[Au] Autor:Cherry N; Arrandale V; Beach J; Galarneau JF; Mannette A; Rodgers L
[Ad] Address:Division of Preventive Medicine, University of Alberta, Alberta, Canada.
[Ti] Title:Health and Work in Women and Men in the Welding and Electrical Trades: How Do They Differ?
[So] Source:Ann Work Expo Health;, 2018 Feb 17.
[Is] ISSN:2398-7316
[Cp] Country of publication:England
[La] Language:eng
[Ab] Abstract:Objectives: There is little information on how work tasks, demands, and exposures differ between women and men in nominally the same job. This is critical in setting workplace standards that will protect the health of both men and those women moving into less traditional work roles. Information used in setting standards is currently based almost entirely on male workers. This paper describes differences in work and health, and the relation between them, in women and men who have undergone the same trade training for the welding or electrical trades. Method: Four cohorts were established. Two were women across Canada in the welding and electrical trades who had been in an apprenticeship since 2005. Cohorts of men in the same trades during the same period were established in the province of Alberta, Canada. Participants completed a baseline questionnaire at recruitment and were followed up every 6 months to collect detailed information on work carried out and on their health and habits. At the end of the study (up to 5 years for women and up to 3 years for men), the cohort members completed a final questionnaire including questions on mental health, harassment, and gender. Results: The four cohorts comprised 1001 welders (447 female; 554 male) and 885 in the electrical trades (438 female; 447 male). Follow-up information was available for 89%. Women were more likely than men to have had some post-secondary education before starting their trade and were less likely to be living as married or to have a child. More welders smoked, and more men were heavy drinkers. At recruitment, more welders than those in the electrical trades reported rhinitis (sneezing and runny nose), depression, and anxiety. Female welders reported more depression (38%) than male welders (30%), compared to 24% in the electrical trades. At first follow-up, new-onset shoulder pain was more frequent in men and new-onset asthma or wheezing in welders. Within each trade, women reported less variety in tasks. Women welders were less likely to be employed in construction than men, and women were less likely to become industrial electricians. Overall, 54% of women and 46% of men reported never using respiratory protection when welding. In the end-of-study questionnaires received to date, 49% reported bullying or harassment during the apprenticeship, with higher proportions in welding than electrical trades and in women compared with men. Such harassment was reflected in higher anxiety and depression scores. Conclusions : This is the first report on these four cohorts and demonstrates the capacity for detailed analysis of the differences in exposure and new-onset occupationally related ill-health. While women and men in the same trades appear to be doing broadly similar work, and to have similar patterns on health at the first follow-up, there are some significant differences in the types of employment and variety of tasks. The very detailed information collected will allow more precise estimates of exposures to be correlated with health outcomes at the end of the follow-up period.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1802
[Cu] Class update date: 180222
[Lr] Last revision date:180222
[St] Status:Publisher
[do] DOI:10.1093/annweh/wxy007

  8 / 3995 MEDLINE  
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[PMID]: 29254325
[Au] Autor:Celletti R; Fanali S; Laici CU; Santori C; Pignatelli P; Sinjari B
[Ad] Address:Department of Medical, Oral and Biotechnological Sciences, University G. d’Annunzio Chieti-Pescara, Chieti, Italy.
[Ti] Title:Instant loading with intraoral welding technique and PRAMA implants: a new prosthetic approach.
[So] Source:J Biol Regul Homeost Agents;31(4):1127-1131, 2017 Oct-Dec.
[Is] ISSN:0393-974X
[Cp] Country of publication:Italy
[La] Language:eng
[Ab] Abstract:When splinting multiple implants passive fit of the framework should be achieved to avoid excessive force distribution on the implants. Recently, a protocol was suggested for immediate loading of multiple implants by welding a titanium bar to implant abutments directly in the oral cavity so as to create a customized, precise and passive metal-reinforced provisional restoration. The intraoral welding technique subsequently proves to be a successful option in the full-arch immediate restorations of the mandible and maxilla. The aim of this article is to present a case report in which a new prosthetic approach, using trans-mucosal implants, is described. Dental implants are instantly loaded with a provisional prosthesis supported by an intraoral welded titanium framework to obtain a precise passive fit of the immediate loaded prosthesis.
[Mh] MeSH terms primary: Dental Implants
Mandible/surgery
Maxilla/surgery
Titanium
Welding/methods
[Mh] MeSH terms secundary: Adult
Humans
Male
Osseointegration/physiology
Treatment Outcome
[Pt] Publication type:CASE REPORTS; JOURNAL ARTICLE
[Nm] Name of substance:0 (Dental Implants); D1JT611TNE (Titanium)
[Em] Entry month:1802
[Cu] Class update date: 180222
[Lr] Last revision date:180222
[Js] Journal subset:IM
[Da] Date of entry for processing:171220
[St] Status:MEDLINE

  9 / 3995 MEDLINE  
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[PMID]: 29460694
[Au] Autor:Sivapirakasam SP; Mohan S; Santhosh Kumar MC; Thomas Paul A; Surianarayanan M
[Ad] Address:a Industrial Safety Engineering Lab, Department of Mechanical Engineering , National Institute of Technology , Tiruchirappalli , India.
[Ti] Title:Control of exposure to hexavalent chromium concentration in shielded metal arc welding fumes by nano-coating of electrodes.
[So] Source:Int J Occup Environ Health;:1-15, 2018 Feb 20.
[Is] ISSN:2049-3967
[Cp] Country of publication:England
[La] Language:eng
[Ab] Abstract:Background Cr(VI) is a suspected human carcinogen formed as a by-product of stainless steel welding. Nano-alumina and nano-titania coating of electrodes reduced the welding fume levels. Objective To investigate the effect of nano-coating of welding electrodes on Cr(VI) formation rate (Cr(VI) FR) from a shielded metal arc welding process. Methods The core welding wires were coated with nano-alumina and nano-titania using the sol-gel dip coating technique. Bead-on plate welds were deposited on SS 316 LN plates kept inside a fume test chamber. Cr(VI) analysis was done using an atomic absorption spectrometer (AAS). Results A reduction of 40% and 76%, respectively, in the Cr(VI) FR was observed from nano-alumina and nano-titania coated electrodes. Increase in the fume level decreased the Cr(VI) FR. Discussion Increase in fume levels blocked the UV radiation responsible for the formation of ozone thereby preventing the formation of Cr(VI).
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1802
[Cu] Class update date: 180220
[Lr] Last revision date:180220
[St] Status:Publisher
[do] DOI:10.1080/10773525.2018.1436014

  10 / 3995 MEDLINE  
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[PMID]: 29460514
[Au] Autor:Pasqualini ME; Lauritano D; Rossi F; Dal Carlo L; Shulman M; Meynardi F; Colombo D; Manenti P; Comola G; Zampetti P
[Ad] Address:MD DDS Private practice Milano, Italy.
[Ti] Title:Rehabilitations with immediate loading of one-piece implants stabilized with intraoral welding.
[So] Source:J Biol Regul Homeost Agents;32(2 Suppl. 1):19-26, 2018 Jan-Feb.
[Is] ISSN:0393-974X
[Cp] Country of publication:Italy
[La] Language:eng
[Ab] Abstract:The authors present an implant prosthesis procedure that uses screws on one-piece implants connected with a titanium pin at their abutment level and one supporter titanium bar in order to guarantee immediate stabilization. These can be implanted and fitted with customized temporary crowns in a single surgical procedure, restoring function and aesthetics and consenting recovery of the bone deficit with reduced healing times and limited patient discomfort. One-piece wide-diameter titanium screw implants with thread measurements of 2.1 and 2.6 mm (smaller diameter) up to diameter of 4.5 mm with one abutment of 2.0 and 2.5 mm respectively, were positioned and splinted by intraoral welding. One-piece titanium implants were used together with a pin (needle) titanium implant as supporting structure to achieve deep stabilization. The Scialom-like pin has a diameter of 1.2 mm and it is long enough to reach deep cortical bone that is “bicorticalism”. The One-piece implant is tightly connected to the needle implant by means of Mondani intra-oral welding technique. In severely atrophic anterior maxilla, the use of this method allows the immediate loading of a fixed resin prosthesis soon after surgery. These implants yielded satisfactory functional and aesthetic outcome in bone-deficient upper anterior sectors, without invasive regenerative procedures. The low invasiveness of this approach also consents rapid healing, reduced biological burden and greater patient benefit.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1802
[Cu] Class update date: 180220
[Lr] Last revision date:180220
[St] Status:In-Data-Review


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