Application of SVM Models for Classification of Welded Joints

Classification algorithm based on the support vector method (SVM) was used in this paper to classify welded joints in two categories, one being good (+1) and the other bad (−1) welded joints. The main aim was to classify welded joints by using recorded sound signals obtained within the MAG welding process, to apply appropriate preprocessing methods (filtering, processing) and then to analyze them by the SVM. This paper proves that machine learning, in this specific case of the support vector methods (SVM) with appropriate input conditions, can be efficiently applied in assessment, i.e. in classification of welded joints, as in this case, in two categories. The basic mathematical structure of the machine learning algorithm is presented by means of the support vector method

Conventional Shaping the Edges of Thick Steel Plates After Welding Process

The paper presents the results of theoretical analysis and experimental details of shaping the edges of thick steel plate using conventional technology. The aim was to determine the influence of holes laser cutting on the shape and technological possibilities of the steel sheet edges flanging. In this study numerous computer simulations were made in order to design a process guaranteeing obtaining a proper product. During this simulation of material flow kinematics, strain and damage criterion distributions and shaping were analyzed. On the basis of the obtained results, the analysis of limiting phenomena, which could appear during the process, was made. Experimental tests in industrial conditions according to designed technology were carried out. Good quality of specimens shaping was obtained. It was found that shaping the edges of thick steel plate after welding process is possible

Silicon and Iron Differently Alleviate Copper Toxicity in Cucumber Leaves

Copper (Cu) toxicity in plants may lead to iron (Fe), zinc (Zn) and manganese (Mn) deficiencies. Here, we investigated the effect of Si and Fe supply on the concentrations of micronutrients and metal-chelating amino acids nicotianamine (NA) and histidine (His) in leaves of cucumber plants exposed to Cu in excess. Cucumber (Cucumis sativus L.) was treated with 10 mu M Cu, and additional 100 mu M Fe or/and 1.5 mM Si for five days. High Cu and decreased Zn, Fe and Mn concentrations were found in Cu treatment. Additional Fe supply had a more pronounced effect in decreasing Cu accumulation and improving the molar ratio between micronutrients as compared to the Si supply. However, the simultaneous supply of Fe and Si was the most effective treatment in alleviation of Cu-induced deficiency of Fe, Zn and Mn. Additional Fe supply increased the His but not NA concentration, while Si supply significantly increased both NA and His whereby the NA:Cu and His:Cu molar ratios exceeded the control values indicating that Si recruits Cu-chelation to achieve Cu tolerance. In conclusion, Si-mediated alleviation of Cu toxicity was directed toward Cu tolerance while Fe-alleviative effect was due to a dramatic decrease in Cu accumulation

Silicon and Iron Differently Alleviate Copper Toxicity in Cucumber Leaves

Copper (Cu) toxicity in plants may lead to iron (Fe), zinc (Zn) and manganese (Mn) deficiencies. Here, we investigated the effect of Si and Fe supply on the concentrations of micronutrients and metal-chelating amino acids nicotianamine (NA) and histidine (His) in leaves of cucumber plants exposed to Cu in excess. Cucumber (Cucumis sativus L.) was treated with 10 mu M Cu, and additional 100 mu M Fe or/and 1.5 mM Si for five days. High Cu and decreased Zn, Fe and Mn concentrations were found in Cu treatment. Additional Fe supply had a more pronounced effect in decreasing Cu accumulation and improving the molar ratio between micronutrients as compared to the Si supply. However, the simultaneous supply of Fe and Si was the most effective treatment in alleviation of Cu-induced deficiency of Fe, Zn and Mn. Additional Fe supply increased the His but not NA concentration, while Si supply significantly increased both NA and His whereby the NA:Cu and His:Cu molar ratios exceeded the control values indicating that Si recruits Cu-chelation to achieve Cu tolerance. In conclusion, Si-mediated alleviation of Cu toxicity was directed toward Cu tolerance while Fe-alleviative effect was due to a dramatic decrease in Cu accumulation

Analysis of Zones Created with Waterjet Cutting of AISI 316 L Corrosion Resistant Steel

This work deals with the quality of machined surface obtained with waterjet cutting (WJC) technology, regarding the influence of selected dynamic parameters (traverse speed, abrasive mass flow rate and pressure) on the quality of machined surface. Examination presented in the work was carried out on specimens made from AISI 316L corrosion resistant steel and measured with portable surface roughness tester. Results obtained by experiment were analyzed with licensed version of software for statistical analysis Design Expert 10

Etiology and mechanisms of ulnar and median forearm nerve injuries

© 2015, Institut za Vojnomedicinske Naucne Informacije/Documentaciju. All rights reserved. Bacgraund/Aim. Most often injuries of brachial plexus and its branches disable the injured from using their arms and/or hands. The aim of this study was to investigate the etiology and mechanisms of median and ulnar forearm nerves injuries. Methods. This retrospective cohort study included 99 patients surgically treated in the Clinic of Neurosurgery, Clinical Center of Serbia, from January 1st, 2000 to December 31st, 2010. All data are obtained from the patients' histories. Results. The majority of the injured patients were male, 81 (81.8%), while only 18 (18.2%) were females, both mainly with nerve injuries of the distal forearm – 75 (75.6%). Two injury mechanisms were present, transection in 85 patients and traction and contusion in 14 of the patients. The most frequent etiological factor of nerve injuries was cutting, in 61 of the patients. Nerve injuries are often associated with other injuries. In the studied patients there were 22 vascular injuries, 33 muscle and tendon injuries and 20 bone fractures. Conclusion. The majority of those patients with peripheral nerve injuries are represented in the working age population, which is a major socioeconomic problem. In our study 66 out of 99 patients were between 17 and 40 years old, in the most productive age. The fact that the majority of patients had nerve injuries of the distal forearm and that they are operated within the first 6 months after injury, promises them good functional prognosis