60 research outputs found
Effect of thermal diffusivity of insulating materials on room free-float temperature with façade external insulation
External insulation of building façade is widely used to reduce heating energy demand in buildings. Usually, its design concerns only thermal transmittance, while transient thermal behaviour is commonly addressed only as dumping factor or time lag of outdoor heat wave. During summer, in many mild climates, outdoor daily mean temperature is close to comfort temperature. Yet, even though mean heat transfer through building envelope is null, heating during daytime may lead to positive cooling loads or discomfort temperatures in non-conditioned rooms. In residential buildings internal loads are usually very low, so the most relevant loads are heat transfer though outer facades. Moreover, where there is no cooling, wall dumping factor is not meaningful to evaluate the thermal performance of wall insulation, as it is referred to constant indoor temperature. In this framework, a model of a room with a single outer wall has been developed to study the effect of insulating material on free-float temperature. Transient heat transfer through the envelope as well as through inner walls is considered to model indoor air temperature. Different localities in Italy and commonly used insulating materials are considered
Dimensionless Correlations for Natural Convection Heat Transfer from a Pair of Vertical Staggered Plates Suspended in Free Air
Buoyancy-induced convection from a pair of staggered heated vertical plates suspended in free air is studied numerically with the main scope to investigate the basic heat and momentum transfer features and to determine in what measure any independent variable affects the thermal performance of each plate and both plates. A computational code based on the SIMPLE-C algorithm for pressure-velocity coupling is used to solve the system of the governing conservation equations of mass, momentum and energy. Numerical simulations are carried out for different values of the Rayleigh number based on the plate length, as well as of the horizontal separation distance between the plates and their vertical alignment, which are both normalized by the plate length. It is observed that an optimal separation distance between the plates for the maximum heat transfer rate related to the Rayleigh number and the vertical alignment of the plates does exist. Based on the results obtained, suitable dimensionless heat transfer correlations are developed for each plate and for the entire system
Natural convection from multiple horizontal cylinders arranged side by side
Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.Steady laminar free convection in air from a row of parallel circular cylinders, is studied numerically. SIMPLE-C algorithm is used for the solution of the mass, momentum, and energy transfer governing equations. Simulations are performed for 10- cylinder assemblies with inter-cylinder spacings from 0.6 to 5 cylinder-diameters and Rayleigh numbers from 101 to 105. It is found that the thermal performance of the whole assembly increases as the Rayleigh number increases, and has a peak at an optimum separation distance among the cylinders which decreases with increasing the Rayleigh number.cs201
Buoyancy-induced heat transfer from an inclined tube-array
Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.No abstract available, please open full text articleSteady laminar free convection in air from an inclined array of parallel circular cylinders, is studied numerically. SIMPLE-C algorithm is used for the solution of the mass, momentum, and energy transfer governing equations. Simulations are performed for tube-arrays consisting of 3 to 7 cylinders equally-spaced at a center-to-center separation distance of 2 cylinder-diameters, tilting angles from 0° to 90° (which correspond to the vertical and horizontal settings, respectively), and Rayleigh numbers in the range between 102 and 106. It is found that the thermal performance of the whole array increases (a) with increasing both the Rayleigh number and the tilting angle, and (b) as the number of cylinders either decreases at small inclinations or increases at large inclinations.cs201
Natural convection from multiple horizontal cylinders arranged side by side
Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.Steady laminar free convection in air from a row of parallel circular cylinders, is studied numerically. SIMPLE-C algorithm is used for the solution of the mass, momentum, and energy transfer governing equations. Simulations are performed for 10- cylinder assemblies with inter-cylinder spacings from 0.6 to 5 cylinder-diameters and Rayleigh numbers from 101 to 105. It is found that the thermal performance of the whole assembly increases as the Rayleigh number increases, and has a peak at an optimum separation distance among the cylinders which decreases with increasing the Rayleigh number.cs201
Buoyancy-induced heat transfer from an inclined tube-array
Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.No abstract available, please open full text articleSteady laminar free convection in air from an inclined array of parallel circular cylinders, is studied numerically. SIMPLE-C algorithm is used for the solution of the mass, momentum, and energy transfer governing equations. Simulations are performed for tube-arrays consisting of 3 to 7 cylinders equally-spaced at a center-to-center separation distance of 2 cylinder-diameters, tilting angles from 0° to 90° (which correspond to the vertical and horizontal settings, respectively), and Rayleigh numbers in the range between 102 and 106. It is found that the thermal performance of the whole array increases (a) with increasing both the Rayleigh number and the tilting angle, and (b) as the number of cylinders either decreases at small inclinations or increases at large inclinations.cs201
Laminar natural convection heat transfer from vertical and inclined plates facing upwards and downwards
Paper presented at the 6th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 30 June - 2 July, 2008.No abstract available, please open full text articlevk201
Simultaneous laminar natural convection above and below tilted thin plates
Paper presented at the 6th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 30 June - 2 July, 2008.No abstract available, please open full text articlevk201
Recent Advances in Cervical Cancer Management: A Review on Novel Prognostic Factors in Primary and Recurrent Tumors
Background: Several pathological parameters, including tumor size, depth of stromal invasion, lympho-vascular space invasion and lymph node status, have been proposed as prognostic predictors in cervical cancer. However, given the high mortality and recurrence rate of cervical cancer, novel parameters that are able to provide additional prognostic information are needed in order to allow a better prognostic stratification of cervical cancer patients. Methods: A search was conducted on PubMed to identify relevant literature data regarding prognostic factors in cervical cancer. The key words “cervical cancer”, “prognostic factors”, “pathology”, and “outcome” were used. Results: The novel pathological grading system based on tumor budding and cell nest size appeared the most relevant prognostic factor in primary neoplasms. Moreover, other potentially useful prognostic factors were tumor size, depth of stromal invasion, lympho-vascular space invasion, perineural invasion, tumor-free distance and tumor-infiltrating lymphocytes. Prognostic factors related to advanced-stage cervical cancer, including lymph-nodes status, endometrial and cervical involvement as well as distant metastases, were also taken into consideration. Conclusions: According to our findings, tumor budding and cell nest size grading system, depth of stromal invasion, lympho-vascular space invasion, perineural invasion, tumor-free distance and tumor-infiltrating lymphocytes appeared the most relevant factors included in the pathology report
TEX (TEst stand for X-band) at LNF
TEX facility if commissioned for high power testing to characterize
accelerating structures and validate them for the operation on future particle
accelerators for medical, industrial and research applications. At this aim,
TEX is directly involved in the LNF leading project EuPRAXIA@SPARC_Lab. The
brief description of the facility and its status and prospective will be
provided.Comment: Talk presented at the International Workshop on Future Linear
Colliders (LCWS 2023), 15-19 May 2023. C23-05-15.
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