6 research outputs found

    Analysis of Heat Transfer in the Material during Pulsed Laser-Metal Interaction by Using Kinetic Theory

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    Nowadays technological developments, the use of lasers in production is increasing and plays an important role due to low cost and high accuracy. The heat transfer, over the course of laser-metal interplay, has a great importance in metal forming. In this study, different types of materials were investigated in order to designate the temperature distributions inside material and on the material surface versus the thermodynamic properties of the material used and then the temperature distributions obtained from the analysis were compared each other. In addition, the heat transfer is occurring during the interaction of the laser power of 1.1010 W/m2 and 5.1010 W/m2 with laser power intensity in two main groups using different materials these are steel, nickel, tantalum and titanium, and numerical results are obtained using the finite-difference method. In the first step, a solution is obtained by electron kinetic theory according to the basic heat transfer. In the second step, since heat convection is formed after material has reached the melting point. Using electron kinetic theory model for convection solutions have been obtained. Moreover, the temperature distribution that occurs during the laser metal interaction was studied by variation of the time chart and the material depth. As a result of the study, material's surface at the correct temperature of liquid phase change material and increased depth in the direction perpendicular to the electro-kinetic theory approach is further demonstrated by the decrease in the first manner and then remains constant in exponential phase change temperature. In addition to this the analysis results, the substrate temperature increases, the change in phase in the material becomes smaller and smaller

    Adsorption of Nitrogen Dioxide (NO2) for Different Gas Concentrations, Temperatures and Relative Humidities by using Activated Carbon Filter: An Experimental Study

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    Noxious gases can be reduced through activated carbon; nevertheless, this process is very complex due to the changing parameters. Nitrogen dioxides take place in the so-called reactive gases. The nitrogen dioxide concentration existing in the environment can be harmful, in particular for asthmatics and it also has the potential to bring about other serious diseases. For instance, interior diseases are often caused by nitrogen oxide gases. Through this study, we have observed the nitrogen dioxide adsorption on the active carbon for varying air temperatures, gas concentrations and air relative humidities. In this context, it has been examined the effect of all three parameters. While conducting this project, we have used parameters between 1ppm and 30ppm (for NO2 concentration), 23°C and 33°C (for air temperature), 30% and 90% (for air relative humidity). In order to understand this process, breakthrough curves of NO2evaluated from experiments have been used in the present study. Results show that the humidity has not a remarkable effect on the adsorption of NO2; however, increasing relative humidity causes to a decrease in the capacity of the activated carbon for NO2 adsorption. Additionally, NO2 adsorption is exothermic, therefore it increases the air temperature

    A snapshot of geriatric infections in Turkey: ratio of geriatric inpatients in hospitals and evaluation of their infectious diseases: A multicenter point prevalence study

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    Introduction: The human population is aging at an astonishing rate. The aim of this study is to capture a situation snapshot revealing the proportion of individuals aged 65 years and over among inpatients in healthcare institutions in Turkey and the prevalence and type of infections in this patient group in order to draw a road map. Materials and Methods: Hospitalized patients over 65 years at any of the 62 hospitals in 29 cities across Turkey on February 9, 2017 were included in the study. Web-based SurveyMonkey was used for data recording and evaluation system. Results: Of 17,351 patients 5871 (33.8%) were ≥65 years old. The mean age was 75.1 ± 7.2 years; 3075 (52.4%) patients were male. Infection was reason for admission for 1556 (26.5%) patients. Pneumonia was the most common infection. The median length of hospital stay was 5 days (IQR: 2–11 days). The Antibiotic therapy was initiated for 2917 (49.7%) patients at the time of admission, and 23% of the antibiotics prescribed were inappropriate. Healthcare-associated infections developed in 1059 (18%) patients. Urinary catheters were placed in 2388 (40.7%) patients with 7.5% invalid indication. Conclusion: This study used real data to reveal the proportion of elderly patients in hospital admissions. The interventions done, infections developed during hospitalization, length of hospital stay, and excessive drug load emphasize the significant impact on health costs and illustrate the importance of preventive medicine in this group of patients. © 2020 The Author
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