Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Thermal conductivity

Study the Effect of Glass and Carbon Fibers on the Firebrick Properties

H.A. Jaber

Engineering and Technology Journal, 2017, Volume 35, Issue 4, Pages 391-398

This work was carried out to investigate effect of glass fiber (GF) and carbon fiber (CF) on kaolin-clay firebrick properties. GF and CF are considered inorganic fibers with application of high temperatures. Kaolin clay is mixed with short GF and CF separately by different percentages (0, 0.5, 1, 1.5 and 2) wt%. Kaolin-GF and kaolin-CF mixtures were compacted by using the semi-dry pressing method. The compacted specimens were fired at different temperatures (1100, 1200 and 1300)°C. Properties which include bulk density, apparent porosity, water absorption, thermal conductivity and fracture strength were obtained from the firebrick specimens. The results show that the addition of GF has beneficial in lowering of firing temperature, and consequently accelerating the densification via enhanced grain boundary diffusivity. Increasing GF content in the firebrick mixture enhances the fracture strength due to increase amount of glassy and mullite phases. Incorporation of CF has inversely affected than GF on the firebrick properties. As the percentage of CF increased the density of firebrick decreased, and the porosity and water absorption increased.

Evaluation of Acoustics Insulation and Thermal Conductivity through Walls in Building

Haqi Ismael Qatta

Engineering and Technology Journal, 2013, Volume 31, Issue 6, Pages 1131-1150

Anew type of porous clay bricks is proposed , this research studies the effect of adding industrial wastes admixtures with different percentages on the thermal and acoustics insulation properties of clay bricks . Different types of admixtures were used in this work ,including plastic cuttings ,wood saw dust ,palm fiber with ( 5% ,10% ,15% ,20 ) percent of weight of each one . Acoustics insulation , thermal conductivity ,specific heat capacity ,porosity and variation of density have been examined for each samples at all percent of admixtures and comparing with the reference clay bricks samples . Form the obtained test result show the admixtures effect on the properties of clay bricks , the best material which can used from this paper is palm fiber to get the best properties of acoustic insulation , thermal conductivity and density for 20% admixtures percentage comparing with the standard bricks .

One Parameter Composite Semigroups of Linear Bounded Operators in Strong Operator Topology of Schatten Class Cp

Samir Kasim Hassan; Al-Taie M; Al-Malki Anam; Al-Attar Abeer; Mustafa Khaleel Ismael; Fatema Ahmed Sadeq; Radhi A .Zboon; Jehad R.Kider; Samir K .Hassan; Hussain J. M. Alalkawi; Raad H. Majid; Rawaa A. Alomairy; Luma Abdul Ghani Zghair; Hadia Kadhim J.Al-Ogili; Assifa M. Mohamad; Abbas Sheyaa Alwan; Haider L. Aneed; Assim H Yousif; Salema Sultan Salman; Abbas Hussien Miry; Abduladhem A.Ali; Mohammed Zeki Al-Faiz; Sabah N. mahmood; Khansaa Dawood Selman; Shaymaa Tareq Kadhim

Engineering and Technology Journal, 2011, Volume 29, Issue 8, Pages 1463-1470

For semigroups of linear bounded operators on Hilbert spaces, the problem of
being in Cp , 0 Keywords

Manufacture of Light Weight Ceramic Bodies as Thermal Insulator From Local Material

Al-Taie M; Al-Malki Anam; Al-Attar Abeer

Engineering and Technology Journal, 2011, Volume 29, Issue 8, Pages 1471-1481

The research work covers a study of the feasibility of producing
lightweight ceramic thermal insulation bodies used for lining the furnaces
by adding saw dust and AlF3 to the Dewechla clay (Kaolinite).AlF3 is a
chemical waste materials in the Akashat–factories in Rutba to the
Dewechla clay (kaolinite). Finely distributed Saw dust and ALF3 were
added to clay with different weight percentages (0, 15, 25, 35 & 40) Wt%.
Cylindrical shape samples (30mm diameter and 30 mm height) were
prepared by using the semi–dry method, moulding pressure was
(500Kg/cm²). After drying at (110C◦), the samples were burnt at (900, 950,
1000, 1050&1100) C◦. The fired samples were investigated to obtain their
properties, bulk density, porosity ,compressive strength and thermal
conductivity. It was possible to produce ligh-weight ceramic thermal
insulators with bulk density between (700 and 1300) Kg/m³ compressive
strength not less than (25) Kg/cm² and thermal conductivity between (0.2
and 0.4) Kcal/m.h.c.

Insulating Light Weight Aggregate Concrete

Engineering and Technology Journal, 2010, Volume 28, Issue 13, Pages 678-691

The weather in Iraq is hot in summer and cold in winter. Therefore , the
thermal insulation is of the main problems facing the engineers working in
building and housing sector
The paper presents an experimental investigation, It includes preparation of
several concrete mixes using lightweight aggregate (siporex and porcelinite &
suwdast ) to obtain light weight concrete of two densities ranging from (350-880
kg/m3), which provides a good thermal insulation. Based on the analysis of
experimental results several graphs and Tables have been prepared and presented
which can be used in the mix design of similar siporex concrete of densities from
(350-880 kg/m3) . The physical properties of siporex concrete , have been found
which included density (765-822kg/m3) , compressive strength (1.51-2.2 N/mm2)
& (2.8-3.7 N/mm2) ,thermal conductivity ( 0.19-0.39 W/M.K) for the two groups

Study of Thermal Characteristics of a Composite Specimen Experimentally and by Using Finite Element Method

Jawad Kadhim Uleiwi; Sura Salim

Engineering and Technology Journal, 2008, Volume 26, Issue 4, Pages 429-441

This research deals with the study of the effect of fibers volume
fraction and fibers orientation on the thermal conductivity and wall surface
temperatures for composite specimen in form of Lee’s disk by using
experimental work and finite element technique. The results show that
the thermal conductivity increases with increasing fiber volume fraction of
the composite specimen, and in the longitudinal direction is larger than in
the lateral fiber direction.The experimental results indicated that the largest
value of the thermal conductivity for the composite specimen was (0.611
W/m.°c) at (Vf = 40 %) in the longitudinal direction, while the lowest value
was (0.195 W/m.°c) at (Vf = 10 %) in the lateral direction. Also the results
show that the maximum difference for the thermal conductivity between the
experimental work and finite element method was ( 7 % ) at ( Vf = 10 % )
in the lateral direction while the minimum value was ( 3.5 % ) at ( Vf = 40
% ) in the longitudinal direction.