scholarly journals INFLUENCE OF PHYSICAL PROPERTIES ON THERMAL CONDUCTIVITY OF POLYSTYRENE INSULATION MATERIALS

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Zahida Ademović ◽  
Jasmin Suljagić ◽  
Jasmin Zulić
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Chemical Properties ◽  
Expanded Polystyrene ◽  
Insulation Material ◽  
Physical And Chemical Properties ◽  
Foam Polystyrene ◽  
Coefficient Of Thermal Conductivity ◽  
Physical And Chemical ◽  
And Chemical Properties

Polymers based on polystyrene are widely used as thermoplastic materials due to the diversity in application, easy processability and a relatively low price. About 45% of the produced polystyrene is produced as compact and foamed products. Cellular foam polystyrene could be produced as expanded polystyrene (EPS) and extruded polystyrene (XPS) and is mainly used as insulation material. Therefore, physical and chemical properties of expanded and extruded polystyrene is of particular importance for thermal conductivity of the material. In this study, four types of expanded polystyrene were tested. Coefficient of thermal conductivity and the resistance of heat transfer were measured and compared to as well as mecahnical properties of the materials. It was confirmed that the density and thickness of the polystyrene influence the resistance of heat transfer.

Analysis of Physical and Chemical Properties of XLPE Insulation for Long Term Running Cable

2018 ◽  
Vol 922 ◽  
pp. 186-191
Author(s):  
Tao Zhang ◽  
Shi Chao Nie ◽  
Ze Hua Pan ◽  
Zhi Wei Li ◽  
Nai Kui Gao ◽  
...  
Keyword(s):  
Mechanical Property ◽  
High Temperature ◽  
Chemical Properties ◽  
Insulation Material ◽  
Physical And Chemical Properties ◽  
Term Operation ◽  
Physical And Chemical ◽  
Xlpe Insulation ◽  
And Chemical Properties

High temperature caused by copper core would have a certain impact on the performance of XLPE insulation during the long running process of the cable. In this paper, the XLPE/PVC cable running for 17years was investigated by using thermal analysis, microstructure analysis, mechanical property analysis and dielectric properties analysis. The influences of long-term operation for the physical and chemical properties of cable insulation are analyzed by the performance of the insulation material. DSC results indicated that position of shoulder peak would characterize the thermal history of material and express the crystal size distribution of XLPE indirectly. Mechanical property test results showed that effect of long term high temperature would decrease the elongation at break and breaking strength of XLPE. SEM results showed that the effect of long term high temperature increased the average size of crystal and the distribution of the crystal became concentrated, meanwhile it verified the relevant conclusion of DSC.

Statistical criteria of stellar population types

1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska
Keyword(s):  
Stellar Population ◽  
Chemical Properties ◽  
Spectrophotometric Study ◽  
Physical And Chemical Properties ◽  
Population Type ◽  
The Galaxy ◽  
Distribution Parameters ◽  
Physical And Chemical ◽  
Statistical Criteria ◽  
And Chemical Properties

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.

Response of corn (Zea mays L.) to various organic-based fertilizers in marginal upland of Sta. Rita, Samar

2017 ◽  
pp. 31-43
Author(s):  
Berta Ratilla ◽  
Loreme Cagande ◽  
Othello Capuno
Keyword(s):  
Block Design ◽  
Management Strategies ◽  
Chemical Properties ◽  
Organic Fertilizers ◽  
Growth And Yield ◽  
Physical And Chemical Properties ◽  
Total N ◽  
Randomized Complete Block Design ◽  
Physical And Chemical ◽  
And Chemical Properties

Organic farming is one of the management strategies that improve productivity of marginal uplands. The study aimed to: (1) evaluate effects of various organic-based fertilizers on the growth and yield of corn; (2) determine the appropriate combination for optimum yield; and (3) assess changes on the soil physical and chemical properties. Experiment was laid out in Randomized Complete Block Design, with 3 replications and 7 treatments, namely; T0=(0-0-0); T1=1t ha-1 Evans + 45-30-30kg N, P2O5, K2O ha-1; T2=t ha-1 Wellgrow + 45-30-30kg N, P2O5, K2O ha-1; T3=15t ha-1 chicken dung; T4=10t ha-1 chicken dung + 45-30-30kg N, P2O5, K2O ha-1; T5=15t ha-1 Vermicast; and T6=10t ha-1 Vermicast + 45-30-30kg N, P2O5, K2O ha-1. Application of organic-based fertilizers with or without inorganic fertilizers promoted growth of corn than the control. But due to high infestation of corn silk beetle(Monolepta bifasciata Horns), its grain yield was greatly affected. In the second cropping, except for Evans, any of these fertilizers applied alone or combined with 45-30-30kg N, P2O5, K2O ha-1 appeared appropriate in increasing corn earyield. Soil physical and chemical properties changed with addition of organic fertilizers. While bulk density decreased irrespective of treatments, pH, total N, available P and exchangeable K generally increased more with chicken dung application.

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