Monitoring of focusing tube wear during abrasive waterjet (AWJ) cutting of AISI 309

The paper deals with the investigating the possibility of using vibrations as a potential source of information for the detection of the malfunctions during the abrasive supplying and focusing tube wear in the process of AWJ. The tested material was the stainless steel AISI 309. Variable factors in the experiment were the abrasive mass flow ma and the focusing tube diameter df. The scanned vibration signal of the material was subjected to frequency analysis. With the increase of the abrasive mass flow, the shift of the amplitudes will follow the opposite direction and decrease. Frequency spectra of all assessed signals are similar by shape in the high-frequency area

Association between HSV1 Seropositivity and Obesity: Data from the National Health and Nutritional Examination Survey, 2007–2008

BACKGROUND: Herpes simplex virus (HSV) is among the most common sexually transmitted pathogens in the United States and worldwide. HSV has a high incidence of undetected cases. In addition, there is no treatment, and there is a lack of knowledge why disparities among populations exist. Research studies suggest that fat tissue may participate in body's immune responses, and the impact of obesity on susceptibility to HSV1 infection is not clear. The purpose of this study was to examine whether obesity is a risk factor for HSV1 infection using a large sample from the general population. METHODS/PRINCIPAL FINDINGS: This cross-sectional study used data from the National Health and Examination and Nutritional Examination Survey (NHANES) from 2007-2008. Variables, gender, age, race/ethnicity, marital status, education, poverty level, and diabetes represented potential confounders and were included in analyses. The two-tailed Pearson's chi square, student's t test, and a multiple logistic regression analysis were applied to evaluate associations using a significance value of p≤0.05. Adjusted odds ratios with 95% confidence interval represented the degree of these associations. The prevalence of HSV1 infection in US population between 20 and 49 years old was 60.3% (n = 1,536). In this study, having a BMI classified as the obese group (BMI 30-39.9) was significantly associated with HSV1 infection before [unadjusted OR = 1.74 (95% CI 1.20-2.51), p = 0.006] and after controlling for socio-demographic factors [adjusted OR = 1.50 (95%CI 1.06-2.13)], p = 0.026]. This association was stronger than three already established risk factors of age, female gender, and poverty level. CONCLUSIONS/SIGNIFICANCE: This study provides evidence that obesity may play a role in the susceptibility to HSV1 infection. Findings from this study suggest that obesity should be considered when designing preventive measures for HSV1 infection. These results may also explain why some people acquire HSV1 infections and some do not. Further, these findings may justify an increased emphasis on the control and prevention of HSV1 transmission and other pathogens in overweight and obese populations

Design of the model for the on-line control of the AWJ technology based on neural networks

279-287The paper focuses on the problem of prediction of surface roughness in AWJ process and contributes to the online monitoring of the hydro-abrasive material disintegration process and its possible control. The main scope of the paper is to contribute to the usage of an artificial neural network as a decisive part in the surface roughness prediction and to outline a suitable online control mechanism. In paper a series of experiments are conducted to predict surface roughness and to use phenomena like acoustic emission and vibrations that accompany the cutting process to use in a possible process control. The model of artificial neural network is created in the MATLAB environment. In total, 150 configurations of multilayer perceptron with different configurations of numbers of neurons in hidden layers are developed. Two training functions, the Bayesian regularization and the Levenberg–Marquardt algorithm, are used during the network training. The results of the realized experiment have shown that the network with feedforward topology is able to predict correct value of the profile roughness parameter

Sustainable cooling strategies to reduce tool wear, power consumption and surface roughness during ultrasonic assisted turning of Ti-6Al-4V

Issues related to the machinability of difficult-to-machine materials such as Titanium and Nickel base superalloys are well explicated in the literature. In this regard, a novel study, applying ultrasonic vibration along with MQL and LCO2, is proposed to enhance the machinability of Ti-6Al-4V. In this regard, this article attempts to analyze machinability of Ti-6Al-4V in conventional and Ultrasonic Assisted Turning (UAT) under dry, wet, MQL and LCO2. The experiments are performed on an in-house developed ultrasonic assisted turning setup, keeping all the machining parameters constant. The main tool wear mechanisms observed are diffusion, adhesion, abrasion, and built-up edge formation in both cutting strategies. Moreover, the LCO2 and ultrasonic vibration significantly reduce specific cutting energy without compromising the surface roughness and tool life. Ultimately, the LCO2, along with ultrasonic assisted turning, promotes sustainability in the machining of Ti-6Al-4V

Molecular basis for the 3',5'-cyclic adenosine monophosphate resistance of Kin mutant Y1 adrenocortical tumor cells.

Orientador: Prof. Dr. Jörg W. MetzgerCoorientadora: Prof. M.Sc. Marielle FeilstreckerDissertação (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduação em Meio Ambiente Urbano e Industrial, em parceria com o SENAI/PR e a Universität Stuttgart, Alemanha. Defesa : Curitiba, 22/11/2017Inclui referênciasResumo: O gerenciamento de áreas contaminadas no Brasil é estabelecido pela Resolução CONAMA N.° 420/2009. Uma importante etapa desse processo é a avaliação de risco à saúde humana, que precede a fase de remediação. Além de caracterizar, avaliar e quantificar os riscos associados a uma contaminação, a avaliação de risco possibilita a definição de concentrações limites, para as quais o risco associado é considerado aceitável. Este trabalho teve como objetivo comparar duas ferramentas utilizadas no processo de quantificação de riscos à saúde humana. A metodologia proposta envolveu a realização de com três simulações da quantificação de riscos e concentrações máximas aceitáveis utilizando as planilhas da CETESB e o software RISC5 com dados de uma área verídica contaminada com percloroetileno e tricloroetileno. Duas simulações envolveram a aplicação dos dados padrão de cada ferramenta, enquanto na terceira foram igualados todos os valores de entrada. As planilhas da CETESB apresentaram resultados mais conservadores e em prol da segurança da população. Ambas as ferramentas quantificaram concentrações máximas aceitáveis impraticáveis para a área avaliada por serem muito próximas ou menores do que os limites legais vigentes. Diante do estudo realizado concluiu-se que as principais diferenças entre as ferramentas são: a flexibilidade de inserção de informações sobre a área avaliada, as informações em seus bancos de dados e a metodologia de cálculo das concentrações máximas aceitáveis. Dessa forma, dentre as ferramentas analisadas, recomenda-se o uso das planilhas da CETESB em estados que ainda não possuem sua própria ferramenta para avaliação de riscos à saúde humana. Palavras-chave: Áreas contaminadas. Solventes organoclorados. Avaliação de Risco à Saúde Humana. Planilhas da CETESB. RISC5.Abstract: The management of contaminated sites in Brazil is regulated by CONAMA's Resolution No. 420/2009. A human health risk assessment is an important step, which precedes the remediation phase. In addition to characterizing, assessing and quantifying the risks associated with contamination, the risk assessment determines concentrations for which the associated risk is considered acceptable. This study compared two tools used in the process of quantifying risks to human health. The methodology involved three simulations of risk quantification and maximum acceptable concentrations using CETESB worksheets and RISC5 software with data from a site that's contains perchlorethylene and trichloroethylene contamination. Two of the simulations involved the application of the standard data of each tool, while the third matched all the input values. The results showed that CETESB worksheets presented more conservative results, regarding the safety of the population. Both tools quantified impracticable maximum acceptable concentrations for the site as they were very close to or less than the legal limits. In view of this study, it was concluded that the main differences between the compared tools were: the flexibility of inputting information about the evaluated site, the information in its databases and the methodology for calculating the maximum acceptable concentrations. Therefore, among the analyzed tools, it is recommended to use the CETESB worksheets in states that do not yet have their own tool for assessing human health risks. Key-words: Contaminated areas. Brownfields. Human health risk assessment. Organochlorine solvents. CETESB worksheets. RISC

Experimental and Numerical Assessment of Temperature Field and Analysis of Microstructure and Mechanical Properties of Low Power Laser Annealed Welded Joints

In this present work, laser welding experiments were carried out on 1 mm thin Ti6Al4V sheets using a low power Nd-YAG laser machine without using any filler wire and without edge preparation of welding specimens. The influence of different major process control parameters such as welding speed and power on the yield parameters like temperature field, weld bead geometry, microstructure, and mechanical properties are critically investigated. Experimental results are compared in detail with the simulated results obtained using a commercial 3D finite element model. In the simulation model, temperature-dependent thermal and mechanical properties of plates were considered. The temperature readings were recorded with the aid of K type thermocouples. Forced convection has been assumed near weld zone region because of the movement of the shielding gas. Appreciable agreement is found between the experimental and the simulated temperature fields in most of the cases with few exceptions. These deviations on few occasions may be due to the presence of uncertainties inherently present in the experimental domain and uncertainties in the subsequent temperature sensing techniques by the thermocouples. In addition, annealing has been done at 950 °C, 980 °C, and 1010 °C for one selected parameter (192 W, 6 mm/s). The tensile strength of the samples annealed at 980 °C has been found to be 1048 MPa and it is 3% to 4% higher than that of the usual welded samples