Analysis of Vertical Position SMAW Welding Process Results

Stainless Steel 316 is a steel metal with its main alloys namely Chromium (Cr) and Nickel (Ni). These two alloys make stainless steel resistant to corrosion (rust). Because Stainless Steel 316 is corrosion resistant, this metal is widely used in the aviation industry, the chemical industry and the food industry. Welding is the process of joining two metals by melting the filler metal and the protective metal to the object being welded. The purpose of this final project is the author who will perform welding on 316 Stainless Steel material. The background for selecting 316 Stainless Steel material is to get the latest data about the level of hardness and tensile strength of the welding results. Welding uses SMAW welding with Nikko Steel NSN 316 L electrodes with a diameter of 3.2 mm, variations in the current used are 75A, 95A, and 115A. Single taper welding seam used, the welding method is Vertical Up and Vertical Down. The plate thickness used is 8mm. Tests carried out on the results of welding are hardness testing and tensile testing. The results of the hardness test show that the Base Metal area is the hardest point to determine the HAZ and Weld Metal points. The highest test results were found in the current 115A Vertical Up specimen III of 3323 Kgf.

Gait Patterns and Mood in Everyday Life: A Comparison Between Depressed Patients and Non-depressed Controls

Background Previous laboratory findings suggest deviant gait characteristics in depressed individuals (i.e., reduced walking speed and vertical up-and-down movements, larger lateral swaying movements, slumped posture). However, since most studies to date assessed gait in the laboratory, it is largely an open question whether this association also holds in more naturalistic, everyday life settings. Thus, within the current study we (1) aimed at replicating these results in an everyday life and (2) investigated whether gait characteristics could predict change in current mood. Methods We recruited a sample of patients (n = 35) suffering from major depressive disorder and a sample of age and gender matched non-depressed controls (n = 36). During a 2-day assessment we continuously recorded gait patterns, general movement intensity and repetitively assessed the participant’s current mood. Results We replicated previous laboratory results and found that patients as compared to non-depressed controls showed reduced walking speed and reduced vertical up-and-down movements, as well as a slumped posture during everyday life episodes of walking. Moreover, independent of clinical diagnoses, higher walking speed, and more vertical up-and-down movements significantly predicted more subsequent positive mood, while changes in mood did not predict subsequent changes in gait patterns. Conclusion In sum, our results support expectations that embodiment (i.e., the relationship between bodily expression of emotion and emotion processing itself) in depression is also observable in naturalistic settings, and that depression is bodily manifested in the way people walk. The data further suggest that motor displays affect mood in everyday life.

Study of features in weld root formation under double-sided synchronized arc welding of vertical joints of steel tanks

It is shown that increase in the welding productivity of vertical joints of storage tanks for oil and oil products can be achieved due to the double-sided synchronized formation of the X-shaped groove. To minimize various disturbances, including variation of gap size and root face dimension, computer engineering analysis is performed, which showed that the formation of root pass during welding with the movement of the electrode down (vertical down) with increased dimension of the root face leads to lack of penetration, but during groove filling with the movement of the electrodes up (vertical up) deep penetration is achieved given the considerable root face dimension. It is defined that during welding of 30 mm thickness plates with root face dimension range from 6 to 8 mm, it is necessary to ensure the root gap dimension range from 1.5 to 3 mm along the entire length of the seam. In this case, the remaining unfilled cross-sectional area of the groove is small, which makes it possible to fill it in during single pass under two-arc double-sided welding. There is area of double-sided synchronized welding modes in which the occurrence probability of typical defects during the formation of the weld root is minimal.

COMPUTER ENGINEERING ANALYSIS OF DOUBLE-SIDED MULTI-ARC WELDING OF VERTICAL JOINTS OF TANKS FOR STORING OIL AND OIL PRODUCTS

The possibilities of computer engineering analysis of special features of double-sided multi-arc welding of vertical joints of tanks with thick shells for storing oil and oil products are shown. The analysis was carried out on the basis of a numerical implementation of the unconventional physical and mathematical model of the formation of a melt pool and a weld seam with two pairs of arcs on each side of the joint with a double-sided bevel. It was established that during weld formation with the movement of the electrode down (vertical down), the possibility of supplying the first pair of arcs with pulsed current should be taken into account, and for the second pairs, the possibility of lateral oscillation of the arcs in the groove with delays at the edges. During groove filling with the movement of the electrodes up (vertical up), their lateral oscillations and delays at the edges should be carried out according to an aperiodic law in order to minimize the effects of “magnetic blow”. For root formation, it is recommended to use pulsed welding, and during groove filling - high current welding with low welding speed. The results of the study can be used in the formation of scientifically-based requirements for the welding process and equipment for double-sided multi-arc welding of the vertical joints of tanks for storing oil and oil products.

Detecção e avaliação de efeitos geodinâmicos em uma porção das estações GNSS brasileiras

Neste trabalho apresentamos uma metodologia para detecção de possíveis efeitos geodinâmicos, utilizando dados GNSS, modelos de velocidade SIRGAS, Geológico e Geofísico. As observações GNSS foram processadas para obtenção da variação da coordenada vertical e horizontal. Os modelos de velocidade VEMOS2009 e 2015 serviram como base comparativa para verificar os resultados obtidos com o processamento GNSS. A partir do conjunto de vetores de velocidades das estações da Rede Brasileira de Monitoramento Contínuo (RBMC) obtidos do NNR-NUVEL-1A, estimaram-se os elementos definidores do movimento da placa SOAM. Em seguida, foram realizadas algumas análises e comparações com os vetores de rotação da placa SOAM obtidas pelo modelo APKIM2008. As análises conduzidas tiveram por base observações contínuas, desde 2007 até 2016, junto a uma porção de estações GNSS pertencentes à RBMC (estações SIRGAS-CON). Os resultados considerando os modelos de velocidade de SIRGAS mostraram que após o terremoto no Chile em algumas regiões do Brasil houveram efeitos geodinâmico. Em comparação aos modelos geológico e geofísico observou-se que o campo de velocidade definido no processamento GNSS conseguiu retratar a realidade, como caso de estudo foi considerado a estação de Imbituba. Detection and assessment of geodynamic effects on a portion of Brazilian GNSS stations A B S T R A C TThis work presents a methodology for detecting possible geodynamic effects using GNSS data, SIRGAS, Geological, and Geophysical velocity models. GNSS observations were processed to obtain the variation for the vertical (up) and horizontal coordinates. The VEMOS2009 and 2015 velocity models served as a comparative basis to verify the results obtained with GNSS processing. From the set of velocity vectors of stations belonging to the Brazilian Network for Continuous Monitoring of the GNSS (RBMC) obtained from NNR-NUVEL-1A, estimated the defining elements of the movement of the SOAM plate. Then, it performed some analyses and comparisons with the SOAM plate rotation vectors obtained by the APKIM2008 model. The studies conducted were based on continuous observations, from 2007 to 2016, on a portion of GNSS stations belonging to RBMC (SIRGAS-CON stations). The results considering the SIRGAS velocity models showed that after the earthquake in Chile, in some regions of Brazil, there were geodynamic effects. Comparison to the geological and geophysical models, it was observed that the velocity field defined in GNSS processing was able to portray reality, as well as case study, which was considered the Imbituba station.Keywords: geodynamic, geophysics, geologic, lithospheric plate.

Numerical Analysis on Heat Transfer Characteristics of Supercritical CO2 in Heated Vertical Up-Flow Tube

It is great significance to understand the mechanism of heat transfer deterioration of supercritical CO2 for heat exchanger design and safe operation in the supercritical CO2 Brayton cycle. Three-dimensional steady-state numerical simulation was performed to investigate the behavior of supercritical CO2 heat transfer in heated vertical up-flow tube with inner diameter di = 10 mm and heated length Lh = 2000 mm. Based on the characteristics of inverted-annular film boiling at subcritical pressure, the heat transfer model of supercritical CO2 flowing in the heated vertical tube was established in this paper. The mechanisms of heat transfer deterioration (HTD) and heat transfer recovery (HTR) for supercritical CO2 were discussed. Numerical results demonstrate that HTD is affected by multiple factors, such as the thickness and property of vapor-like film near the wall, the turbulence intensity near the interface between liquid-like and vapor-like, and in the liquid-like core region as well as the distribution of radial velocity vector. Among the above factors, the change of turbulent kinetic energy caused by the buoyancy effect seems to be a more important contributor to HTD and HTR. Furthermore, the influences of heat flux and mass flux on the distribution of wall temperature were analyzed, respectively. The reasons for the difference in wall temperature at different heat fluxes and mass fluxes were explained by capturing detailed thermal physical properties and turbulence fields. The present investigation can provide valuable information for the design optimization and safe operation of a supercritical CO2 heat exchanger.