نتایج جستجو برای: metal working tools
تعداد نتایج: 650836 فیلتر نتایج به سال:
A novel lesion-mask free method based on a gamma mixture model was applied to myelin water fraction (MWF) maps to estimate the association between cortical thickness and myelin content, and how it differs between relapsing-remitting (RRMS) and secondary-progressive multiple sclerosis (SPMS) groups (135 and 23 patients, respectively). It was compared to an approach based on lesion masks. The gam...
Metalworking fluids (MWF) play a significant role in manufacturing processes, such as machining or forming. Consequently, a high number of MWF with varying chemical composition are commercially available. However, the working mechanisms of the MWF are still object of discussion in science and application. This paper addresses the possible interactions of additives with metal surfaces taking the...
This is part of a series of review articles on formaldehyde-releasers and their relationship to formaldehyde contact allergy. Formaldehyde-releasers used in metalworking fluids (MWF) and a group of releasers not presented in previous articles are discussed. Here, in Part 1 of the article, there is a short overview of the composition and functions of MWF, the function of biocides in them, and ad...
The aim of this review was to assess current knowledge related to the occupational exposure limit (OEL) for fluid aerosols including either mineral or chemical oil that are generated in metalworking operations, and to discuss whether their OEL can be appropriately used to prevent several health risks that may vary among metalworking fluid (MWF) types. The OEL (time-weighted average; 5 mg/m(3), ...
Purpose – The purpose of this paper is to provide a practical review of metal working fluids and their implications to the machining practice. Despite their widespread use and applications, there are several scientific and economic factors that call for an investigation of current practices and development of new approaches. Design/methodology/approach – There are numerous methods that diverge ...
METHODS In British Columbia, Canada, nineteen small machine shops which used water-based metalworking fluids (MWF) were examined. One bulk MWF sample was taken from each independent sump (N=140) and tested for endotoxin using the Limulus Amoebocyte Lysate assay. Factors that might influence the MWF sump endotoxin concentration were investigated using mixed effect multiple regression modelling t...
Metalworking fluid emulsion formulations produced from vegetable oils may be less toxic and may reduce disposal costs when compared with fluids formulated with petroleum-based oils. Experiments were performed on experimental emulsions made with unmodified and modified soybean oils to measure rates of mist production by impaction, centrifugal force and evaporation/recondensation mechanisms. Resu...
The metalworking and machining industry utilizes recirculating metalworking fluids for integral aspects of the fabrication process. Despite the use of biocides, these fluids sustain substantial biological growth. Subsequently, the high-shear forces incurred during metalworking processing aerosolize bacterial cells and may cause dermatologic and respiratory effects in exposed workers. We quantif...
OBJECTIVES Investigating the potential of myelin repair strategies in multiple sclerosis (MS) requires an understanding of myelin dynamics during lesion evolution. The objective of this study is to longitudinally measure myelin water fraction (MWF), an MRI biomarker of myelin, in new MS lesions and to identify factors that influence their subsequent myelin content. METHODS Twenty-three MS pat...
Metalworking fluids (MWFs) are harmful to the environment and to the health of workers, resulting in pressures to re-design them in accordance with sustainable manufacturing principles. In this paper, we review research being performed at the University of Michigan to minimize the life cycle environmental and health impacts of metalworking fluids while simultaneously improving manufacturing per...
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