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Assessment and Utilization of Some Egyptian Clay Deposits for Producing Lightweight Concrete
Ali Ismail,
Hamed Mekky,
Mohamed Saad Elmaghraby
Issue:
Volume 3, Issue 3, May 2014
Pages:
79-83
Received:
18 March 2014
Accepted:
14 April 2014
Published:
30 April 2014
Abstract: The clay materials were collected from Fayoum area (F- type) and Alamine area (A- type and S- type). Swelling and PH measurnments for the selected raw clay materials were measured. Chemical and mineral composition was investigated using XRF and XRD, respectively. Chemical analysis confirms that F type has higher alumina than the other two types of clay A and S. Kaolinite is an essential mineral in F type while it occurs in minor amount in A and S types. Montmorillonite detected classified into calcium montmorillonite and sodium montmorillonite. Calcium montmorillonite is observed in F type while sodium montmorillonite is detected in both samples of S and A types. PH value results refer to the F type is slightly below 7 while the S and A types are above 8. Swelling measurements showed also different values in the three types of clay materials reaching a value of 300% in S- types 100% in soil A and 50% in F- type. The data of swelling and PH confirm the distribution of montmorillonite in the three types of clay materials. The bloataility of the fired granules in term of density show that the lowest density for A and S types (0.84 and 0.65 g/cm3 at 1150o C respectively.) compared with the F type (1.75g/cm3) at 1200o C. XRD patterns of the fired clay samples confirm that A and S mainly composed of quartz and hematite as well as some albite in restricted to A type. F sample record mullite in addition to the cristobalite and quartz. Lightweight concretes blocks of low density and relatively good strength are tested for producing and utilized in modern building trend for dead–load construction and wall construction were prepared from clay materials under investigation by firing the A and S types up to 1150oC using a rate of heating 20oC/min
Abstract: The clay materials were collected from Fayoum area (F- type) and Alamine area (A- type and S- type). Swelling and PH measurnments for the selected raw clay materials were measured. Chemical and mineral composition was investigated using XRF and XRD, respectively. Chemical analysis confirms that F type has higher alumina than the other two types of ...
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Low Temperature Direct-Write Fabrication of Radio Frequency Identification Circuit and Antenna Structures on Polymer Substrates
Alu,
Noble O.,
Oberafo,
Anthony A.,
Iwok,
Unwana U.,
Adama,
Kenneth K.,
Imalerio,
Thomas I.
Issue:
Volume 3, Issue 3, May 2014
Pages:
84-87
Received:
26 March 2014
Accepted:
16 April 2014
Published:
20 May 2014
Abstract: We report the direct-write fabrication of electric circuits on polyethylene terephthalate (PET) substrates by a low temperature technique. To demonstrate the utility of the concept, Radio Frequency Identification Circuit and Antenna Structures were fabricated on polyethylene terephthalate (PET), using a 300 dpi drop-on-demand HP DeskJet system. First, each substrate was prepared by low frequency atmospheric plasma etching, followed by tin (II) chloride treatment to enhance wetting. Then a catalytic silver seed layer pattern was bubble-jet printed onto the surface. Finally, the substrate was developed in a copper electroless plating bath for 10 min. to yield a 2.5 µm copper film with a sheet resistance of 3.4 Ωsq. The as-deposited film was shiny with a surface roughness of less than 8.7nm, which is about 0.35% of the film thickness. The films were characterized by SEM, EDX, profilometry, optical microscopy, and four-point probe resistivity measurement. This technology may be adapted for the direct-write fabrication of antenna structures for communication devices and space science applications.
Abstract: We report the direct-write fabrication of electric circuits on polyethylene terephthalate (PET) substrates by a low temperature technique. To demonstrate the utility of the concept, Radio Frequency Identification Circuit and Antenna Structures were fabricated on polyethylene terephthalate (PET), using a 300 dpi drop-on-demand HP DeskJet system. Fir...
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The Application Status and Prospects of Magneto-Rheological Fluid
Yuan Shu,
Ren Hongjuan,
Luo Yiping,
Xu Biao
Issue:
Volume 3, Issue 3, May 2014
Pages:
88-91
Received:
16 April 2014
Accepted:
9 May 2014
Published:
30 May 2014
Abstract: As a kind of new intelligent material, magneto-rheological fluid (MRF) has been receiving more and more attentions and applications. In this paper, the components of magneto-rheological fluid and its performance characteristics are mainly introduced. Besides, the authors analyze the advantages of MRF in practical application and its present situation of application in engineering. Finally, the application of MRF in engine dynamometer is studied in detail which will widen the application of magneto-rheological fluid.
Abstract: As a kind of new intelligent material, magneto-rheological fluid (MRF) has been receiving more and more attentions and applications. In this paper, the components of magneto-rheological fluid and its performance characteristics are mainly introduced. Besides, the authors analyze the advantages of MRF in practical application and its present situati...
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Effect of Compressed Plasma Flow on Tantalum-Titanium Thin Layer Deposited on Silicon Substrate
Amir Hossein Sari,
Valentin Mironovich Astashynski,
Anton Mikhailovich Kuzmitski,
Vladimir Vasilevich Uglov
Issue:
Volume 3, Issue 3, May 2014
Pages:
92-99
Received:
18 April 2014
Accepted:
6 May 2014
Published:
30 May 2014
Abstract: The interaction of a dense compressed nitrogen plasma flow with a system of Ta-Ti layers on a silicon substrate has been investigated. This plasma flow was generated in a quasi-stationary pulsed plasma accelerator that can provide a supersonic high energy plasma flux. The plasma pulse duration, discharge current, concentration, and energy densities absorbed by the target were 100 µs, 80 kA, 1018 cm−3, and 3–13 J/cm2 respectively. The samples were exposed to a single plasma pulseor to a series of pulses and were characterized by scanning electron microscopy, X-ray diffraction, and energy dispersive X-ray analyses. The result showed that the changes in the elemental and structure phase compositions depends on energy and number of plasma pulses. Formation of Ti5Si3 and Ta2N, are the main results of the current research.
Abstract: The interaction of a dense compressed nitrogen plasma flow with a system of Ta-Ti layers on a silicon substrate has been investigated. This plasma flow was generated in a quasi-stationary pulsed plasma accelerator that can provide a supersonic high energy plasma flux. The plasma pulse duration, discharge current, concentration, and energy densities...
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New Findings and Interpretation on Atmospheric Adsorption Induced Instability in Microcrystalline Silicon Films
Tae-Hyeon Lim,
Hyuk-Ryeol Park
Issue:
Volume 3, Issue 3, May 2014
Pages:
100-105
Received:
1 May 2014
Accepted:
17 May 2014
Published:
30 May 2014
Abstract: In this investigation, we added some new findings and interpretations on the behaviors of both electrical conductivities and optical absorption spectra upon adsorption of atmospheric molecules in microcrystalline silicon films (μc-Si:H). The photo conductivity followed similar decay-recover processes upon air exposure-thermal anneal cycles as did the dark conductivity. The dark and photo conductivities decay according to a stretched-exponential function with time upon air exposure. The absorption spectra showed a reduced defect absorption for the films at air exposed state compared with those of at thermal annealed state. There is a one-to-one correspondence between atmospheric adsorption in μc-Si:H and bias-stress induced instabilities in a-Si:H thin film transistors(TFTs).
Abstract: In this investigation, we added some new findings and interpretations on the behaviors of both electrical conductivities and optical absorption spectra upon adsorption of atmospheric molecules in microcrystalline silicon films (μc-Si:H). The photo conductivity followed similar decay-recover processes upon air exposure-thermal anneal cycles as did t...
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Thermal and Tensile Mechanical Behavior of Acetic Anhydride Treated Silk Fibres
Md. Minhaz-Ul Haque,
Mst. Ayesha Akther Zaman,
M. H. Rahaman,
M. Z. Hossain,
M. Maniruzzaman
Issue:
Volume 3, Issue 3, May 2014
Pages:
106-110
Received:
2 May 2014
Accepted:
17 May 2014
Published:
30 May 2014
Abstract: Acylation of fibres can provide a route to have materials with better water proofing capability. In our present study, silk fibres were treated with various concentration (5, 10 and15 wt.%) of acetic anhydride aqueous solution and then thermal properties, tensile mechanical behaviour and moisture content of acetic anhydride treated silk fibres were studied. Raw silk fibres were taken as control for comparison. It was found that elastic modulus and tensile strength of silk fibres were increased with increasing acetic anhydride concentration while elongation at break was decreased with increase of acetic anhydride content in solution. Silk fibres treated with 15 wt. % of acetic anhydride solution exhibited about 141% (from 17 GPa to 41 GPa) improvement in elastic modulus. It was also found that acetic anhydride treated silk fibres displayed higher thermal resistance and lower moisture content as compared to untreated silk fibres.
Abstract: Acylation of fibres can provide a route to have materials with better water proofing capability. In our present study, silk fibres were treated with various concentration (5, 10 and15 wt.%) of acetic anhydride aqueous solution and then thermal properties, tensile mechanical behaviour and moisture content of acetic anhydride treated silk fibres were...
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Physical Properties and Influence of the Tempering on Electric Properties Films Bi2Te3
Musaver Musayev,
Sedreddin Axmedov,
Gurban Axmedov
Issue:
Volume 3, Issue 3, May 2014
Pages:
111-115
Received:
18 May 2014
Accepted:
7 June 2014
Published:
20 June 2014
Abstract: Processes of oxidation in the films Bi2Te3 used in the various thermoelectric film devices working on air at various temperatures are investigated. Samples Bi2Te3 of p-type thickness received 0,5-1,5 microns a method of discrete evaporation with additional homogenization of a steam phase. Changing technological conditions to raise dust and tempering, have received samples with a wide set of concentration of carriers of a charge from 5х1018 up to 6х1019 cm-3. The fact of formation oxide layers proves to be trues the data electronography the analysis. The electronogram tempering samples alongside with dot reflexes from monocrystal blocks have the continuous polycrystalline rings adequate to a phase of structure Bi2O3. The method of diffraction electron with high energy – electrongraphy investigates formation of phases in the film condition, received by joint evaporation the components of system Bi - S. Experimentally investigated dependence of the near nuclear order in amorphous layered Bi2S3 from conditions of reception of thin layers - besieged as under influence on molecular pair an external electric field intensity 3000Vxcm-1, and outside of a field. It is established, that internuclear distances and radiuses of coordination spheres in layered, received in conditions of influence of an electric field, are a little shortened in comparison with those without influence of a field.
Abstract: Processes of oxidation in the films Bi2Te3 used in the various thermoelectric film devices working on air at various temperatures are investigated. Samples Bi2Te3 of p-type thickness received 0,5-1,5 microns a method of discrete evaporation with additional homogenization of a steam phase. Changing technological conditions to raise dust and temperin...
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Optical and Structural Properties of CdS/ZnSe Bi-Layer Thin Films Prepared by E-Beam Technique
Raghu Patel,
Naveen Chickmagalur Shivappa,
Shailaja Jeetendra,
Ganesh Sanjeev,
Murugaiya Sridhar Ilango,
Mahesh Hampapatna Matt
Issue:
Volume 3, Issue 3, May 2014
Pages:
116-120
Received:
6 June 2014
Accepted:
17 June 2014
Published:
30 June 2014
Abstract: Single and bi-layer thin films of Cadmium Sulphide (CdS) and Zinc Selenide (ZnSe) were prepared on glass and ITO/Glass substrates by e-beam technique. Spectral transmittance of bi-layer thin film showed red shift with prolonged interference effect. The decrease in Urbach tail of bi-layer thin film signifies the decreased band gap with increased grain size. Single layer CdS film has prominent (002) hexagonal peak where as bi-layer thin film confirm with (002) hexagonal and (111) cubic peaks of CdS and ZnSe respectively. CdS grain size was found to be 14.5, 17.1, and 33.1 nm on glass, ITO/Glass and ZnSe/ITO/Glass substrates respectively.
Abstract: Single and bi-layer thin films of Cadmium Sulphide (CdS) and Zinc Selenide (ZnSe) were prepared on glass and ITO/Glass substrates by e-beam technique. Spectral transmittance of bi-layer thin film showed red shift with prolonged interference effect. The decrease in Urbach tail of bi-layer thin film signifies the decreased band gap with increased gra...
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