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Development of Novel Polymer Phase Change Material for Heat Storage Application
Issue:
Volume 2, Issue 6, November 2013
Pages:
168-172
Received:
7 September 2013
Published:
20 October 2013
Abstract: Polymer Phase change material (PCM's) are materials used to store Energy for a broad range of Applications. Unlike conventional storage materials, PCM absorbs and release heat at a nearly constant temperature. They store 5–14 times more heat per unit volume than sensible storage materials. Increasing demand in solar engineering and spacecraft thermal control applications; require the continuous development of such materials to maximize its efficiency. One of the options is to develop energy storage devices, which are as important as developing new sources of energy. In This paper we can show that combination of low Density Polyethylene (LDPE) paraffin wax and glycerin is an alternative material that can be used as PCM's. Differential Scanning Calorimeter (DSC); Melt Flow Index test and FTIR technique were used to characterize the new developed Compound. Results obtained indicate that a reduction of more than 10°C in melting temperature (Tm) of the pure LDPE-resin was achieved.
Abstract: Polymer Phase change material (PCM's) are materials used to store Energy for a broad range of Applications. Unlike conventional storage materials, PCM absorbs and release heat at a nearly constant temperature. They store 5–14 times more heat per unit volume than sensible storage materials. Increasing demand in solar engineering and spacecraft therm...
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Dielectric Relaxation, Ionic Conduction and Complex Impedance Studies on NaNo3 Fast Ion Conductor
T. Vijay kumar,
A. Sadananda Chary,
Suresh Bhardwaj,
A. M. Awasthi,
S. Narender Reddy
Issue:
Volume 2, Issue 6, November 2013
Pages:
173-178
Received:
22 September 2013
Published:
30 October 2013
Abstract: AC conductivity, dielectric constant, loss and electric modulus of Sodium nitrate system have been studied in the frequency range from 1Hz to 10MHz and in the temperature range from 303 K to 563 K by employing impedance spectroscopy. The frequency dependent ac conductivity follows Jonscher’s universal power law. Dimensionless frequency exponent (n), dispersion parameter (A) are determined. The change over frequency independent conductivity to frequency dependent conductivity at all temperatures shows the relaxation mechanism. The variation of real part of dielectric constant with frequency shows strong dispersion at low frequencies and saturation at high frequencies. The presence of peaks in the frequency plots of dielectric loss, imaginary parts of impedance and modulus are attributed to the relaxation processes. It is also confirmed by the temperature dependence study of real part of dielectric constant. The activation energy from relaxation processes and conductivity has been evaluated.
Abstract: AC conductivity, dielectric constant, loss and electric modulus of Sodium nitrate system have been studied in the frequency range from 1Hz to 10MHz and in the temperature range from 303 K to 563 K by employing impedance spectroscopy. The frequency dependent ac conductivity follows Jonscher’s universal power law. Dimensionless frequency exponent (n)...
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Optoelectronic Properties of New Synthesized Phtalocyanine
Sarra TOUAITI,
Amira HAJRI,
Mourad Shédy KAHWECH,
Bassem JAMOUSSI
Issue:
Volume 2, Issue 6, November 2013
Pages:
179-184
Received:
17 October 2013
Published:
20 November 2013
Abstract: One novel Zn-phthalocyanine bearing different substituent was synthesized. The resulting compounds were characterized by NMR and FTIR. The corresponding polymer was synthesized via cyclic voltametry. The optical properties of these π-conjugated systems were investigated by UV-Visible absorption and photoluminescence (PL) spectroscopy. The electrochemical behavior was reported. The optical and electrochemical gaps were estimated. Those complexes, having low gap energy, have been identified as holding much promise for the developpement of photovoltaic device.
Abstract: One novel Zn-phthalocyanine bearing different substituent was synthesized. The resulting compounds were characterized by NMR and FTIR. The corresponding polymer was synthesized via cyclic voltametry. The optical properties of these π-conjugated systems were investigated by UV-Visible absorption and photoluminescence (PL) spectroscopy. The electroch...
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Syntheses, Characterization and Binding Strength of Geopolymers: A Review
OLAWALE Margaret Damilola
Issue:
Volume 2, Issue 6, November 2013
Pages:
185-193
Received:
21 October 2013
Published:
20 November 2013
Abstract: There exist a large number of raw materials sources rich in alumina and silicon with the potential for procuring geopolymers. Among the materials predominate fly ash, calcined clays, puzzolans, kaolins, illite/smectite, metakaolins and slags. Geopolymers results from the reaction of aluminosilicate powder with an alkaline silicate solution. It has been brought to lime light that geopolymer display several usefulness in thermal insulation, thermal shock refractories, production of low energy ceramic tiles, cements and concretes, high-tech composites for aircraft interior and automobile, high-tech resin systems, in radioactive and toxic waste containment, arts and decoration. Geopolymers are generally known to have high compressive strength, fire and acid attack resistance, low water absorption capacity and thermal conductivity. This paper describes different materials suitable for procurement of geopolymer and reviews the trend in the compressive strength and water absorption of different types of synthesized geopolymers. The findings of this study, shows that compressive strength of geopolymer increases with increase in concentration of sodium silicate as well as sodium hydroxide and water absorptivity of any geopolymer decreases with increase in concentration of sodium hydroxide, water glass and duration of the geopolymer curing time.
Abstract: There exist a large number of raw materials sources rich in alumina and silicon with the potential for procuring geopolymers. Among the materials predominate fly ash, calcined clays, puzzolans, kaolins, illite/smectite, metakaolins and slags. Geopolymers results from the reaction of aluminosilicate powder with an alkaline silicate solution. It has ...
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Chemical Baling of Oily Cast Iron Turnings and Use of Bales to Substitute Expensive and Scarce Scrapes
Harast Aliaxandr Ivanavich
Issue:
Volume 2, Issue 6, November 2013
Pages:
194-203
Received:
14 November 2013
Published:
30 November 2013
Abstract: The results of the research are presented as the technology of smelting cast iron using iron-containing substances with organic pollutants as a charge material. Iron- and carbon- containing substances are introduced into the melt as stable components of bales which are not damaged during transportation. Bales are formed under low pressure from iron- containing substances with organic pollutants which do not undergo the preliminary treatment. When bales are produced, cheap materials are used as binders. Binders are formed at the expense of chemical hardening and oxidation of organic pollutants to less environmentally harmful compounds, and refining the melt from contaminants. The composition of bales provides the reduction of iron from its oxide compounds.
Abstract: The results of the research are presented as the technology of smelting cast iron using iron-containing substances with organic pollutants as a charge material. Iron- and carbon- containing substances are introduced into the melt as stable components of bales which are not damaged during transportation. Bales are formed under low pressure from iron...
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Simultaneously Effect of Envinronment and Sustained Load on the Degradation of Aluminium Bonded Joint
Issue:
Volume 2, Issue 6, November 2013
Pages:
204-208
Received:
19 September 2013
Published:
10 December 2013
Abstract: Bonded aluminium single lap joints have been exposed to a fully reversed ageing environment (immersion followed by withdrawal both at 50oC) in both loaded and unloaded conditions with time dependent. Monitoring of these specimens and testing at key points on this reversed ageing environment has led to the stress rupture and moisture dependence of joint mechanical response included creep effect. Moisture cycling and stress influenced the tensile strength of the joints, with some apparent irreversible degradation. However, the effect of environmental exposure, time exposure, pre-treatment and constant stress was significant for the single lap joints damage.
Abstract: Bonded aluminium single lap joints have been exposed to a fully reversed ageing environment (immersion followed by withdrawal both at 50oC) in both loaded and unloaded conditions with time dependent. Monitoring of these specimens and testing at key points on this reversed ageing environment has led to the stress rupture and moisture dependence of j...
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Graphene in Edge-Carboxylated Graphite by Ball Milling and Analyses Using Finite Element Method
J. H. Lee,
C. M. Shim,
B. S. Lee
Issue:
Volume 2, Issue 6, November 2013
Pages:
209-220
Received:
15 November 2013
Published:
10 December 2013
Abstract: Edge-carboxylated graphite (ECG) was produced by grinding pristine graphite in a planetary ball-mill machine. Transmission electron microscope was used to confirm the layers of graphene in ECG. The elemental analyses showed that the oxygen contents are different between ECG samples. The vibrational analysis of single- and five-layered graphene was conducted using finite element method within ANSYS. The vibrational behaviors of cantilevered and fixed graphene with one or five layers were modeled using three-dimensional elastic beams of carbon bonds and point masses. The dynamic analysis was conducted using nonlinear elastic elements within LS-DYNA. The natural frequencies, strain and kinetic energy of the beam elements were calculated considering the van der Waals forces between the carbon atoms in the hexagonal lattice. The natural frequencies, strain and kinetic energy of the graphene sheets were estimated based on the geometrical type and the layered sheets with boundary conditions. In the dynamic analysis, the change in displacement over time appears larger along the x- and y-axes than along the z-axis, and the value of the displacement vector sum appears larger in the five-layer graphene than in the single-layer graphene.
Abstract: Edge-carboxylated graphite (ECG) was produced by grinding pristine graphite in a planetary ball-mill machine. Transmission electron microscope was used to confirm the layers of graphene in ECG. The elemental analyses showed that the oxygen contents are different between ECG samples. The vibrational analysis of single- and five-layered graphene was ...
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Zn-Ni Electrodeposition for Enhanced Corrosion Performance
Tolumoye Johnnie Tuaweri,
Rhoda Gumus
Issue:
Volume 2, Issue 6, November 2013
Pages:
221-227
Received:
4 December 2013
Published:
30 December 2013
Abstract: Zinc-Nickel (Zn-Ni) electrodeposition has been carried out using direct current. Cathode current efficiency and deposit thickness were determined by weight measurement method. Influence of current density on the deposition process was also investigated. The morphologies of the deposits were studied using Scanning Electron Microscope and Field Emission Gun Scanning Electron Microscopes. Effect of temperature on the Ni content and morphologies of the deposits was also studied. Energy dispersive spectroscopy (EDX) was utilised to analyse the elemental composition of the deposits. It was found that temperature changes in the bath had a marked influence on the Ni content and morphology of the deposits. Deposit surface profile revealed non-uniform distribution of Ni in the deposits. Anomalous deposition behaviour was exhibited by the baths and Ni content of 10-15wt% for best corrosion performance was obtained between 60-75 g/l of NiCl2.6H2O. Normal deposition took place at current densities lower than 2A/dm2. Deposits with 12wt% Ni exhibited best corrosion performance.
Abstract: Zinc-Nickel (Zn-Ni) electrodeposition has been carried out using direct current. Cathode current efficiency and deposit thickness were determined by weight measurement method. Influence of current density on the deposition process was also investigated. The morphologies of the deposits were studied using Scanning Electron Microscope and Field Emiss...
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Calculation of Phase Transitions of Uranium Dioxide Using Structure Factor in Molecular Dynamics
Nagornov Yuri,
Katz Andrey
Issue:
Volume 2, Issue 6, November 2013
Pages:
228-232
Received:
8 December 2013
Published:
30 December 2013
Abstract: We calculate phase transitions of uranium dioxide using structure factor in molecular dynamics. Our method is based on analysis of the rate of the structure factor change with the temperature. The temperatures of melting and transition to the superionic state for the uranium dioxide obtained by this method are 3100K and 2600K, respectively. Theses temperatures much better conform to the experimental values of 3120K and 2670K than in the radial distribution function analysis method. Other methods give the melting temperatures substantially higher (3435-3600K) than the experimental value.
Abstract: We calculate phase transitions of uranium dioxide using structure factor in molecular dynamics. Our method is based on analysis of the rate of the structure factor change with the temperature. The temperatures of melting and transition to the superionic state for the uranium dioxide obtained by this method are 3100K and 2600K, respectively. Theses ...
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