1,720,963 research outputs found
Investigation of air temperature and velocity distribution in a room according to different air vent types and locations by computational fluid dynamics analysis
No full textAir handling unit systems are quite large and complex systems that start from air handling units and extend to air vent. Since the system selection and calculations will affect the thermal comfort and indoor air quality, it should be done very carefully. Calculations, the air handling unit and its equipment’s selection may have been correctly and ventilation ducts placement may have been appropriate. However, if the placement of the air vents and the air speed are not selected correctly, there will not be a homogeneous air distribution and the indoor air quality will be negatively affected. In this study, analyzes were run with a computational fluid dynamics program (ANSYS Fluent) at different sizes, different layouts and blowing speeds placed on the ceiling in a space
Thermodynamic evaluation of nanorefrigerant-enhanced cascade refrigeration system
No full textThis study investigates the thermodynamic performance of a cascade refrigeration cycle (CRC) enhanced with ZrO2 and TiO2nanoparticles using various refrigerants. The analysis, conducted using the Engineering Equation Solver (EES), examines key performance parameters such as the coefficient of performance (COP), exergy efficiency, exergy destruction, and compressor work. The findings suggest that nanorefrigerants enhance energy efficiency, with R600 demonstrating the highest COP and exergy efficiency, while R507a exhibits the lowest. It has been demonstrated that the COP and overall exergy efficiency of nano refrigerants with ZrO2 nanoparticles exceed those of TiO2. Additionally, the study highlights the potential of low-global-warming-potential (GWP) refrigerants combined with nanoparticles for enhancing refrigeration performance. The findings provide insights into the viability of nanofluid applications in CRCs and suggest future experimental research to validate the theoretical results
Numerical investigation of the effect of radiator placement on temperature distribution in a room
No full textThis study analyses the impact of radiator placement on temperature distribution in a room using CFD analysis. Radiators are typically placed under windows or on outer walls. However, in the area under study, where there are large windows extending to the floor on the outer walls, the radiator was positioned on the empty inner wall. Two variations of the analysis were conducted using the ANSYS Fluent program. One variation involved a vertical installation of an aluminium panel radiator of the same length as the existing radiator on the outer wall next to one of the two windows. The other variation involved the installation of two radiators of the same length as the existing radiator next to the windows. The results showed that the room heated up faster when two radiators were used compared to other alternatives. Heating a room with two radiators of equal length and surface temperature results in a faster temperature increase. When a radiator is positioned vertically, the average temperature remains the same as the current situation. Using multiple smaller radiators instead of a single large one that provides the same amount of heat allowed the environment to warm up more quickly
Experimental and numerical investigations of thermal comfort and hygienic conditions of an operating room
No full textAmeliyathane iklimlendirme sistemleri hem ameliyathane ekibinin ısıl konforunu sağlamak hem de ortamın hijyenini sağlayabilmek açısından oldukça önemlidir. Yapılan birçok çalışmada ameliyat enfeksiyonlarının büyük kısmının, ameliyathane iklimlendirme sistemine bağlı olduğu görülmüştür. Isıl konfor, önemli derecede hava sıcaklığına, bağıl neme ve hava hızına bağlıdır. Mahalin hijyenini sağlamak için de ortamdaki partikül miktarını en aza indirmek gerekmektedir. Bunu en çok etkileyen faktörler ise havanın filtrasyonu ve havanın mahale dağıtım şeklidir. Yapılan bu çalışmada, türbülanslı ve laminer hava akışlı iki adet ameliyathanede deneyler yapılarak, farklı hava giriş sıcaklıkları ve hızlarında odanın bağıl nem ölçümü, sıcaklığı ve ameliyat masası üzerinden partikül sayımı yapılmıştır. Hava giriş hızının ve sıcaklığının mahal hijyenini ne derecede etkilediğine bakılmıştır. Bu iki ameliyathane ANSYS-Fluent programında modellenerek, yapılan deneylerle analiz sonuçları karşılaştırılmıştır.Operating room air conditioning systems are very important in terms of both providing thermal comfort to the operating room team and ensuring the hygiene of the environment. Many studies have shown that the majority of surgical infections are due to the operating room air-conditioning system. Thermal comfort depends on air temperature, relative humidity and air velocity at significant levels. In order to ensure hygiene of the indoor air, it is necessary to reduce the amount of particles in the environment to the minimum. The most important factors affecting this are air filtration and air distribution. In this study, experiments were carried out in two operating rooms with turbulence and laminar airflow, and the relative humidity measurements, temperature and particle counts on the operation table were performed at different air inlet temperatures and velocities. Inlet air velocity and temperature have affected how much the room hygiene affects. These two operating rooms were modeled in the ANSYS-Fluent program and the results of the experiments were compared
Investigation of Air Temperature and Velocity Distribution in a Room According to Different Air Vent Types and Locations by Computational Fluid Dynamics Analysis
No full textAir handling unit systems are quite large and complex systems that start from air handling units and extend to air vent. Since the system selection and calculations will affect the thermal comfort and indoor air quality, it should be done very carefully. Calculations, the air handling unit and its equipment’s selection may have been correctly and ventilation ducts placement may have been appropriate. However, if the placement of the air vents and the air speed are not selected correctly, there will not be a homogeneous air distribution and the indoor air quality will be negatively affected. In this study, analyzes were run with a computational fluid dynamics program (ANSYS Fluent) at different sizes, different layouts and blowing speeds placed on the ceiling in a space
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
