Search

This study focused on evaluating the effectiveness of various welding processes in reducing volatile gas emissions in work environments, a crucial factor for occupational health and safety. Comparative tests were carried out on three common welding processes: SMAW, GMAW and GTAW, with a focus on the concentration of formaldehyde and other volatile organic compounds (VOCs) in the air. The results revealed high statistical significance between treatments, confirming substantial differences in VOC emissions. The Tukey test identified the GTAW (TIG) process as the most efficient, with a concentration of total volatiles of 0.0557 mg/m?, well below the threshold of 0.2 mg/m?, where it is expected that no irritation or symptoms of discomfort. In contrast, the SMAW and GMAW processes showed concentrations that could lead to irritation or discomfort. Choosing the appropriate welding process is revealed as a critical factor in reducing VOC emissions and protecting workers' health. VOCs, including formaldehyde and carbon monoxide, can have adverse health effects on workers, and compliance with occupational exposure limits is essential. [ABSTRACT FROM AUTHOR]

Flows with excess of kinetic energy produce high speed, overpressures and erosive processes, in this sense the energy dissipaters are hydraulic structures that minimize this effect. These works are usually built in conventional concrete, leaving aside alternative materials such as used tire and gabions. Three energy dissipation structures were evaluated: a stepped channel located on the Bogota -Villavicencio road, a storm sewer well with stepped fall structure located in the municipality of Acacias (Meta) and four free-fall spillway weir built in concrete, positioned on the Fucha river in Bogotá. Modeling on a reduced scale shows that, when incorporating gabions and used tires, the flow type (nappe flow) is conserved, its functionality, energy dissipation is greater than 92%, additionally reduces costs and contributes to the conservation the morphological stability of the channels, particularly, they allow concentrating the flow through the main channel and smoothing the changes of direction. [ABSTRACT FROM AUTHOR]

Copyright of Bistua: Revista de la Facultad de Ciencias Básicas is the property of Facultad de Ciencias Basicas de la Universidad de Pamplona and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Chilena de Cirugia is the property of Sociedad de Cirujanos de Chile and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bistua: Revista de la Facultad de Ciencias Básicas is the property of Facultad de Ciencias Basicas de la Universidad de Pamplona and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Medica del IMSS is the property of Direccion de Prestaciones Medicas - IMSS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Mexicana de Biodiversidad is the property of Universidad Nacional Autonoma de Mexico, Instituto de Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Medica del IMSS is the property of Direccion de Prestaciones Medicas - IMSS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Manfreda galvaniae, a new species from the Barranca de Malinaltenango, mpio. Ixtapan de la Sal, State of Mexico, is described and illustrated. It belongs to the Manfreda guttata (Jacobi et Bouché) Rose group, and is similar to M. pringlei Rose and M. fusca Ravenna. Likewise, the paper presents comments about the taxonomic status of M. malinaltenangensis Matuda, sympatric with M. galvaniae. [ABSTRACT FROM AUTHOR]

Manfreda littoralis, a new species from the seashores of Guerrero and Oaxaca is described and illustrated. It belongs to the Manfreda guttata (Jacobi et Bouché) Rose group, and is similar to M. guttata (Jacobi et Bouché) Rose and M. planifolia (S. Watson) Rose. [ABSTRACT FROM AUTHOR]