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 inhalab...

To address control difficulties in laser welding, we propose the idea of a self-learning and self-improving laser welding system that combines three modern machine learning techniques. We first show the ability of a deep neural network to extract meaningful, low-dimensional features from high-dimensional laser-welding camera data. These features are then used by a temporal-difference learning a...

Shrink-fitting, a common bonding technique in metal assemblies, was used for mortise and tenon wood joints. The joints had considerable strength. Shrink-fitting yielded joint strengths comparable to those obtained by using several welded dowels. Increasing the number of welded dowels, however, produced joints of higher strength than those bonded just by shrink-fitting. Combining in the same joi...

The structural and optical characterization of bulk GeO2-PbO glasses was the goal of this study. In this regard, six different (100-x)GeO2‌-xPbO (15<x<45) glasses were prepared by conventional melt quenching technique between two steel sheets. The produced samples were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) and UV-Vis s...

different glasses suitable for temperature sensing in the fiber optic sensors were studied in this article. the phase changes for eight different glass materials were calculated and results were compared. our results showed that extra dense flint glass is the most sensitive one, while pure silica results in the lowest phase change. in another study the effect of wavelength on the phase variatio...

PURPOSE Welders are exposed to airborne particles from the welding environment and often develop symptoms work-related from the airways. A large fraction of the particles from welding are in the nano-size range. In this study we investigate if the welders' airways are affected by exposure to particles derived from gas metal arc welding in mild steel in levels corresponding to a normal welding d...

this paper presents a new arc starter circuit that is usable in manual metal arc welding (mma) power supplies. the proposed circuit uses an auxiliary circuit and a series coupling transformer for adding high frequency spikes to output dc voltage during arc striking. the proposed circuit is usable in inverter based arc welding supplies and it could result in a decrease of weigh, volume and expen...

INTRODUCTION: Electric arc welding and oxy-fuel gas welding are the commonest welding technologies used in small scale industries in Nigeria. Electric arc welders are exposed to serious health hazards like exposure to welding smoke. Health effects of such exposure include metal fume fever, and increased risk of chronic diseases and cancers. Exposure to welding smoke can be minimized by use of P...

Stud arc welding has become one of the most important unit operations in the mechanical industries. The need to reduce the time from product discovery to market introduction is inevitable. Reducing of standard deviation of tensile strength with desirable tensile strength joint as a performance character was use to illustrate the design procedure. The effects of (welding time, welding current, s...

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 grea...