Vol. 8 & Issue 1 ; Section C : Physical Sciences

Date : Nov.2017 to Jan.2018

 

The Study of a factor to the Carbon Nanotubes Film

Caiping Xi,

JCBPS; Section C; November 2017 – January 2018, Vol. 8, No. 1; 001-006,

[DOI: 10.24214/jcbps.C.8.1.00106.]

  • Abstract

    We do an experiment to prepare the carbon nanotubes. One of the factors affecting the preparation of carbon nanotubes was studied in the article. The experimental results were described by scanning electron microscopy and Raman spectroscopy. The results show that Hydrogen plays important role in the grown of carbon nanotubes and the best Hydrogen Flow of the carbon nanotubes is 30sccm

Corrosion behaviour of heat treatment Cu-Al-Be shape memory alloy in simulation body fluid

Jafar Tahar Al-haidary*, Ali Munder Mastafa, Ahmed Aziz Hamza,

JCBPS; Section C; November 2017 – January 2018, Vol. 8, No. 1; 007-015,

[DOI: 10.24214/jcbps.C.8.1.00715.]

  • Abstract

    Corrosion behaviour of Cu-13Al%-0.545Be% shape memory alloy chemical composition at different microstructure in simulation body fluid by open circuit potential, tafal polarization, cyclic polarization .the microstructure of this alloy that aging at 550 ºC for 2,4 and 6 hour was study by optical microscope and x-ray diffraction (XRD). The transformation temperature of this alloy determined by differential scanning calorimeter (DSC).the result of this test show increase aging time and temperature increase percent of λ2 phase and the alloy with martensite phase have corrosion resistance than alloy with different phases

Microstructure and Microhardness upon High Temperature Heat Treatments in an Nb-Ti-Cr-Si Based Ultrahigh Temperature Alloy

 

Baohui Guo,

JCBPS; Section C ; November 2017 – January - 2018, Vol. 8, No. 1; 016-027,

[DOI: 10.24214/jcbps.C.8.1. 01627.]

  • Abstract

    In order to investigate the effects of high temperature heat treatments on the microstructures and microhardness of an Nb-Ti-Cr-Si based ultrahigh temperature alloy, coupons were homogenized at 1200~1500℃ for 24h and then aged at 1000℃ for 24h. The results show The Nb-Ti-Cr-Si based ultrahigh temperature alloy is composed of Nbss, (Nb,X)5Si3 and Cr2Nb phases after various homogenizing and aging treatments. HfO2 is found in the alloy after heat treatment both at 1500°C for 24 h and 1500°C for 24 h then 1000°C for 24 h. With increase in heat-treatment temperature, previous Nbss dendrites in the arc-melted alloy transform into Nbss equaxied crystals. The previous Nbss/(Nb,X)5Si3 eutectic colonies break into small (Nb,X)5Si3 blocks in Nbss matrix, whereas the previous Nbss/Cr2Nb eutectic colonies in arc-melted microstructure transform into needle-like Laves after homogenizing treatment at 1200°C for 24 h and become coarse Laves blocks after homogenizing at 1300°C for 24 h. The previous Laves Cr2Nb particles dissolve into Nbss during homogenizing treatment at 1400°C for 24 h, and much finer and crowded Cr2Nb platelets form during cooling. These observations suggest that the previous coarse Laves phase particles dissolve between 1300 and 1400°C, and the Ti and Cr concentrations decrease with increase in heat-treatment temperatures. Aging at 1000°C for 24h after homogenizing treatments improves the precipitation of fine needle-like Cr2Nb in Nbss matrix and Cr concentration in Nbss reduces. The variation of partitioning ratios of alloying elements among Nbss, (Nb,X)5Si3 and Cr2Nb causes the change in microhardness of Nbss and (Nb,X)5Si3. The microhardness of Nbss and (Nb,X)5Si3 reaches the maximum value after 1300℃/24h+1000℃/24h heat treatment.

Study on Light Interference Simulation and Performance Evaluation of Low light Imaging System

YUAN Wei and Wang Ze Yu,

JCBPS; Section C ; November 2017 – January - 2018, Vol. 8, No. 1; 028-036.

[DOI: 10.24214/jcbps.C.8.1.02836.]

  • Abstract

    For the modern battlefield influence flares, fire and other battlefield equipment shimmer light source for imaging performance, such as reconnaissance capability, through the study of the interference signal response mechanism are low light level imaging equipment, optical equipment, gain characteristics, and quantitative analysis of the battlefield fire and flares affect both light sources of interference imaging reconnaissance system for low light level imaging performance, respectively, to simulate the interference source is located in a different location, after radiation - the output image after the combined effect of shimmer system response system, revealing micro - transmission optical imaging equipment in the imaging light interference conditions under the law, the establishment of a study to assess the effect on image quality and detection distance changes under strong interference.

Effect of Aluminium Salts on Some Mechanical Properties of Polyvinyl Alcohol (PVA) Films

Sabah A. Salman, Nabeel A. Bakr, Salma S. Abduallah, Huda Zeki Abd Al Rahman,

JCBPS; Section C ; November 2017 – January - 2018, Vol. 8, No. 1; 037-045,

[DOI: 10.24214/jcbps.C.8.1. 03745.]

  • Abstract

    Pure PVA films and PVA films filled with different weight ratios (3, 7, 11 and 15) wt % of aluminium salts (AlCl3.6H2O and Al(NO3)3.9H2O) have been prepared by casting method. The effect of salts on some mechanical properties (hardness and tensile strength) of the prepared films was investigated. The experimental results showed that the hardness of the films increased by increasing the weight ratio of the added aluminium salts, while the tensile test showed unsystematic behaviour of tensile strength, elongation at break and Young's modulus after filling with different weight ratios of the aluminium salts compared with pure (PVA) film.

Antibacterial Activities of Guanidine Family Single Crystals against Bacillus Subtilis and Staphylococcus Aerus

D. Sathya, S. Anbu Radhika, V.Sivashankar1, D. Prem Anand,

JCBPS; Section C ; November 2017 – January - 2018, Vol. 8, No. 1; 046-050,

[DOI: 10.24214/jcbps.C.8.1.04650.]

  • Abstract

    A Guanidine derivative single crystal has been grown by simple ambient temperature gradient solution growth technique. The as grown single crystals tested against two bacterial pathogens like Bacillus subtilis, Staphylococcus aerus. The result shows that the single crystals have better resistance against the microbes. The standard antiseptic solution like kanamycin, it showed less or equal activity in pathogenic bacteria. In comparison to our currently used Guanidine derivatives single crystals, Guanidine Acetate shows better zone of inhibition against both the pathogens. But in contrast the Guanidine maleate and Guanidine Tetrafluroborate reveals lowest zone of inhibition against Bacillus subtilis and Staphylococcus aerus respectively. It can be concluded that Guanidine acetate exhibit excellent antibacterial effect and therefore, seems to be suitable as a local antiseptic agent, but further clinical studies are necessary.

Rheological Characterization of Scenedesmus Sp. Pastes (Up To100 G/L) Produced In A 200-L Raceway and Harvested By Coagulation-Flocculation-Sedimentation

Luis G Torres B, Laura Carrillo, Eduardo Morales, Luis J. Corzo-Rios,

JCBPS; Section C; November 2017 – January 2018, Vol. 8, No. 1; 051-063.

[DOI: 10.24214/jcbps.C.8.1.05163.]

  • Abstract

    The aim of this work was to carry out a complete rheological characterization of Scenedesmus sp. pastes with or without addition of a flocculant in terms of viscosity and viscoelasticity. Rheological measurements were carried out using a simple viscometer and a rheometer. K and n values from the Power law determined using both the viscometer Brookfiel and the rheometer Physica 1000 systems were quite different. Physica 1000 results are more reliable. In the case of this rheometer, viscosity vs. shear rate lines seem to be divided in three shear rate zones: a) below 0.04 s-1, b) between 0.04 and 6 s-1, and c) up to 6 s-1. For the Scenedesmus pastes without chitosan, K values ranged from 0.27 -10.9 Pa.sn, while n values fluctuated between 0.73-0.92 (non-dimensional). R2 values were quite good for all concentrations (from 0.95-0.98). Viscoelastic behavior of the algal suspensions was observed at any of the assessed concentrations. Viscoelastic properties of microalgae suspensions with chitosan are not very different from those presented by the samples without added chitosan. i.e., the elastic component was greater at low frequencies; whereas to high frequencies, the values of both components are equal.

An evaluation of magnetic field and density dependence of the Josephson frequency in atom-Molecule Coherence in Bose gases and study of emergence of molecular Bose-Einstein condensate from a Fermi gas,

Indu Kumari Tiwari, Ashok Kumar Tiwai, R.K. Jha and L.K. Mishra,

JCBPS; Section C ; November 2017 – January - 2018, Vol. 8, No. 1; 064-076,

[DOI: 10.24214/jcbps.C.8.1.06476.]

  • Abstract

    Using the theoretical formalism of R A Duine and H T C Stoof (arXiv: cond-mat/0303230v) 22 March 2003), we have theoretically evaluated magnetic field and density dependence of the Josephson frequency in coherence atom-molecule oscillation in Bose-Einstein condensed gas. Our theoretically obtained results show that Josephson frequency increases with both magnetic field for constant condensate density and also with condensate density for fixed magnetic field. Our theoretically evaluated results are in good agreement with the experimental data and also with other theoretical workers. Using the theoretical formalism of Markes Greiner etal (Nature, 26 Nov (2005)) , we have studied the emergence of molecular Bose-Einstein condensate from a Fermi gas of 6Li atoms. The study has been performed with the help of Feshbach resonance. We have evaluated molecular condensate fraction N0/N as a function of (T/TC) and as a function of (T/TF). We have also evaluated scattering length ‘a’ in unit of a0, of mixture of two lowest hyperfine states of 6Li atom, temperature (μK) all as a function of magnetic field (mT) near the crossing of the scattering length. Our theoretically evaluated results are in good agreement with the other theoretical workers.

Preparation and Study of Some Physical Properties of CuxZn1-xS Thin Films

Nabeel A. Bakr, Asaad A. Kamil, Maryam S. Jabbar,

JCBPS; Section C ; November 2017 – January - 2018, Vol. 8, No. 1; 077-088

[DOI: 10.24214/jcbps.C.8.1.07788.]

  • Abstract

    In this study, CuxZn1-xS (where x= 0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1) thin films have been successfully deposited on glass substrates by chemical spray pyrolysis (CSP) technique at substrate temperature of (400 oC). The thickness of the prepared thin films was about (350 ± 30) nm measured by gravimetric method. Various characterization techniques have been used to investigate the structural and optical properties of the prepared thin films. The XRD results showed that the CuS film has a polycrystalline nature with covellite-hexagonal structure and preferred orientation along (103) plane, and the ZnS film has a polycrystalline wurtzite-hexagonal structure with preferred orientation along (0010) plane, while the thin films prepared with different mixing ratios have a polycrystalline structure and mixture phases of covellite-hexagonal and wurtzite-hexagonal. AFM results showed homogenous and smooth thin films. FESEM results showed the formation nanostructures with different shapes, such as cauliflower, semi-spherical, hexagonal, and in the form of plates and rods. The UVVisible- NIR absorbance spectra were recorded in the range of (350-900) nm ton investigate the optical characteristics. The results have shown that the transmittance of the prepared thin films decreases with increasing the CuS ratio and the absorption coefficient value is (α >104 cm-1) for all prepared thin films, which this in turn proved that the prepared thin films are likely to have direct electronic transitions. It is found that the optical energy gap decreases with increasing the CuS ratio, and it is in the range of (2.12-3.34) eV.

A theoretical study of hybridized quantum spin liquid in an emergent states of heavy-electron materials and evaluation of hybridization effectiveness parameter f0, Coherence temperature T* and static magnetic spin susceptibility of some heavy-electron materials

Madhavi Kumari, Satish Chandra Prasad and L. K. Mishra,

JCBPS; Section C ; November 2017 – January - 2018, Vol. 8, No. 1; 089-102,

[DOI: 10.24214/jcbps.C.8.1.08902.]

  • Abstract

    Using the theoretical formalism of Y-F Yang and D. Pines [Proc Natl Acad Sci USA 109: E3060-E3066 (2012)], we have theoretically studied the hybridized quantum spin liquid in an emergent states in heavy –electron materials. We have evaluated spin susceptibility of spin liquid  XSL (0,0) as a function of T /T* (T* is the coherence temperature at which at which Kondo emerges) for   different values of hybridization effectiveness parameter f0 . Our theoretically evaluated results show that XSL (0,0) decrease with T/T* for all the given values of f0. Our theoretically evaluated results of c-axis spin magnetic susceptibility Xc (a.u) as a function of T /T*  for three heavy-electron materials (CeRhIn5, CeCoIn5 and URu2Si2) keeping T* and f0  fixed for each material indicate that Xc (a.u) decrease with T /T* for each material Using the theoretical formalism of Y-F Yang etal [Phys Rev. Lett (PRL) 103, 199004 (2009)], we have studied the quantum critical behaviour of heavy-electron materials. We have evaluated magnetic field dependent f0 (H), pressure dependent f0 (p) and pressure dependent T* (p) for two materials YbRh2Si2 and CeCoIn5. Our theoretically obtained results show that f0 (H) increases with H for these materials but f0 (p) and T*(p) decrease with p for material YbRh2Si2 and increase with p for CeCoIn5.  Our theoretically evaluated results for specific heat coefficient ϒH (J / molK2) and magneto-resistivity coefficient A( μΩcm / K2 ) as a function of magnetic field H for heavy-electron material YbRh2Si2 show that these quantities decrease with magnetic field. Our theoretically evaluated results are in good agreement with other theoretical workers.These obtained results indicate that two-fluid phenomenological theory of heavy-electron materials quite successfully explains the emergence of lowtemperature ordered state. It also satisfactorily explains the quantum critical behaviour of two heavy-electron compounds YbRh2Si2 and CeCoIn5.