Search results for "Cooling"
showing 10 items of 470 documents
Surface induced smectic order in ionic liquids - an X-ray reflectivity study of [C(22)C(1)im](+)[NTf2](-)
2017
Physical chemistry, chemical physics 19(39), 26651 - 26661 (2017). doi:10.1039/C7CP04852A
Spatial heterogeneity in glassy polystyrene detected by deuteron NMR relaxation
1999
Using deuteron NMR, the dynamics of supercooled polystyrene-d 3 was investigated near the calorimetric glass transition. At these temperatures non-exponential spin lattice relaxation is found, indicating the presence of spatial heterogeneity. With increasing temperature, structural relaxation becomes fast enough to average efficiently over different spatial environments, leading to exponential magnetization decays. A qualitative comparison with toluene as a representative of a low molecular weight glass former is carried out. Indications are found that in polystyrene the observed averaging process is more effective at T g than it is in toluene.
Mesophase formation in poly(propylene-ran-1-butene) by rapid cooling
2009
Abstract The effect of random insertion of low amount of 1-butene of less than about 11 mol% into the isotactic polypropylene chain on structure formation at non-isothermal crystallization at different rate of cooling was investigated by X-ray scattering, density measurements, and atomic force and polarizing optical microscopy. Emphasis is put on the evaluation of the condition of crystallization for replacement of lamellar crystals by mesomorphic nodules on increasing the cooling rate/supercooling. In the polypropylene homopolymer, mesophase formation occurs on cooling at rates larger about 150–200 K s −1 , while in case of poly(propylene- ran -1-butene) mesophase formation is observed on …
Structure, morphology and crystallization of a random ethylene-propylene copolymer
2003
The structure, morphology, and crystallization behavior of a random ethylene–propylene copolymer, containing 2 wt % ethylene sequences, are analyzed and compared with those of a plain polypropylene sample by means of optical and scanning microscopy, wide-angle X-ray scattering, and calorimetry. For the copolymer, different polymorphs (α, γ and smectic modifications) and morphologies can be obtained through changes in the crystallization and annealing conditions. The analysis of the structural results suggests that the γ phase of isotactic polypropylene can be generated for high molecular mass samples with drastic decreases in the undercooling. The spherulite growth rate (G) data, in conjunc…
Evidence of Mechanisms Occurring in Thermally Induced Phase Separation of Polymeric Systems
2014
Thermally induced phase separation is a fabrication technique for porous polymeric structures. By means of easy-to-tune processing parameters, such as system composition and demixing temperature, a vast latitude of average pore dimensions, pore size distributions, and morphologies can be obtained. The relation between demixing temperature and morphology was demonstrated via cloud point curve measurement and foams fabrication with controlled thermal protocols, for the model system poly-l-lactide–dioxane–water. The morphologies obtained at a temperature lower than cloud point showed a closed-pore architecture, suggesting a “nucleation-and-growth” separation mechanism, which produced larger po…
Structural verification and manufacturing procedures of the cooling system, for DEMO divertor target (OVT)
2019
The paper presents the design activities and testing plan of a vertical target mock-up, developed within the pre-conceptual design phase for DEMO Work Package DIV-1 “Divertor Cassette Design and Integration” - EUROfusion Power Plant Physics & Technology (PPPT) program. Activities concerning the Divertor Outboard Vertical Target cooling mock-up are presented in term of CAD model, thermal-hydraulic numerical simulation, structural analysis, structural integrity verification and manufacturing procedure. Moreover, the mechanical dimensions of support systems for Plasma Facing Components (PFCs), manifold and diffuser have been analyzed in detail, in order to avoid structural fault during the tes…
Analysis of the steady state hydraulic behaviour of the ITER blanket cooling system
2015
Abstract The blanket system is the ITER reactor component devoted to providing a physical boundary for plasma transients and contributing to thermal and nuclear shielding of vacuum vessel, magnets and external components. It is expected to be subjected to significant heat loads under nominal conditions and its cooling system has to ensure an adequate cooling, preventing any risk of critical heat flux occurrence while complying with pressure drop limits. At the University of Palermo a study has been performed, in cooperation with the ITER Organization, to investigate the steady state hydraulic behaviour of the ITER blanket standard sector cooling system. A theoretical–computational approach …
On the hydraulic behaviour of ITER Shield Blocks #14 and #08. Computational analysis and comparison with experimental tests
2016
Abstract As a consequence of its position and functions, the ITER blanket system will be subjected to significant heat loads under nominal reference conditions. Therefore, the design of its cooling system is particularly demanding. Coolant water is distributed individually to the 440 blanket modules (BMs) through manifold piping, which makes it a highly parallelized system. The mass flow rate distribution is finely tuned to meet all operation constraints: adequate margin to burn out in the plasma facing components, even distribution of water flow among the so-called plasma-facing “fingers” of the Blanket First Wall panels, high enough water flow rate to avoid excessive water temperature in …
Smart Cooling System for Milk Transportation in Rural Areas
2021
In the dairy industry, road milk tankers transport milk from one location to another. The milk inside the tanker needs to be kept between 3–5 °C to ensure that the quality of milk is always preserved. The tanker needs to be kept running at all time with the case of sufficient energy being continuously supplied to the cooling unit. The source of energy normally used for this application is a typical generator which needs fuel to operate. This is expensive and is not environmentally friendly. To address this problem, generator as a source of energy needs to be replaced by solar energy to lower the costs associated with cooling of the tanker. In this research a small scale solar powered intell…
Long-term fracture load of all-ceramic crowns: Effects of veneering ceramic thickness, application techniques, and cooling protocol
2020
Made available in DSpace on 2021-06-25T10:46:25Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-11-01 Background: To evaluate, in vitro, the effects of the cooling protocol, application technique, and veneering ceramic thickness on the fracture resistance of ceramic crowns with Y-TZP frameworks. Material and Methods: 80 frameworks were made from zirconia by the CAD/CAM technique and divided into 8 groups (n = 10) according to the factors: “application technique” (stratified-L and pressed -P), “thickness” (1 mm and 2 mm), and “cooling protocol” (slow-S and fast-F) of the feldspathic veneering ceramic. After, all crowns were cemented over G10 preparations with resin cement (Panavia F, …