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☑ A Comparative LPG sensing study of bulk titanium oxide and nanostructured titanium oxide

Anuradha Yadav1, and B. C. Yadav2

1Nanomaterials and Sensors Research Laboratory, Department of Physics,University of Lucknow, Lucknow-226007, U.P., India

2Department of Applied Physics, School for Physical Sciences,Babasaheb Bhimrao Ambedkar University, Lucknow-226025, U.P., India

  • subtitlesABSTRACT

    This paper is focused on the comparative LPG sensing performances of bulk titanium dioxide and the synthesized TiO2 through hydrolysis of TiCl3 . The mean value sensitivity for different volume percentages (1-5%) of LPG has been estimated. Sensor response as a function of exposure time and response time has also been calculated. The average sensitivity and sensor response of the sensing element made of Titania synthesized through hydrolysis of TiCl3 are found to be maximum 3.0 and 318 respectively for 5 vol.% of LPG. Response time of the sensor was 70 sec. SEM images show that synthesized TiO2 is more porous than the obtained from Qualigens before exposure to the LPG. The minimum crystallites size of the purchased TiO2 and synthesized TiO2 are found to be 65 nm and 18 nm respectively. XRD patterns divulge that TiO2 is tetragonal and crystalline in nature. The device response was found to be concentration dependent, slow at low concentration and fast at higher concentrations.

  • gamesKEYWORDS

    LPG Sensor;TiO2 ; SEM; XRD; Sensitivity.

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☑ Heavy Metal uptake from Industrial Effluents using Natural Zeolitic Aluminosilicates

Marina G. Xavier and Samuel F. Banda

Department of Chemistry, University of Zambia, P.O. Box 32379, Lusaka, Zambia

  • subtitlesABSTRACT

    The uses of zeolites derive from their special properties: They can interact with water to adsorb or release ions (ion exchange); they can selectively adsorb ions that fit the cavities in their structures (molecular sieves). The locally available zeolite samples have been proved to have application in reducing toxic waste and causes driven by environmental concern and energy consumption. Cation-containing zeolites can differentiate molecules on the basis of their electrostatic interactions with the metal ions, size difference, shape and polarity. The adsorption properties of certain specific pore sized zeolites are useful for size selective separation of molecules. The high cation exchange capacity of zeolites as evident from our studies combined with their selective affinity for specific cations make them uniquely suited to various application in disposal of Industrial effluents like Cu, Cr, Co, Zn etc. The heavy metal ions were quantified using atomic absorption spectroscopy before and after the process of adsorption. This promising adsorbent is found to exhibit 90% adsorption efficiency with most of the heavy metals.

  • gamesKEYWORDS

    Heavy metals; adsorption; cation exchange capacity; effluent treatment.

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☑ Preparation and mechanical properties of pine needle/ polypropylene bio-composites

Ramakrishna .M1, Vivek kumar2, Yuvraj Singh Negi3, Aradhyula Thirumala Vasu*1, Murthy Chavali4

1Department of Mechanical Engineering, Vignan’s Foundation for Science, Technology and Research University (VFSTRU; Vignan University), Vadlamudi 522 213 Andhra Pradesh, India

2Department of Paper Technology, Indian Institute of Technology Roorkee, Saharanpur Campus, Saharanpur 247 001 India

3Department of Polymer and Process Engineering, Indian Institute of Technology Roorkee, Saharanpur Campus, Saharanpur 247 001 India

4Division of Chemistry, Department of Sciences and Humanities, Vignan’s Foundation for Science, Technology and Research University (VFSTRU; Vignan University), Vadlamudi 522 213 Andhra Pradesh, India

  • subtitlesABSTRACT

    The main objective of the present work is to develop a low-cost eco-friendly and biodegradable reinforced thermoplastic composites utilizing pine needle fibers as reinforcing materials. Pine needle/polypropylene composites were prepared with varying load of fillers, and varying dosage of compatibilizer (MA-g-PP) to improve the interface bonding between fiber and the matrix. Composites were prepared by using treated Pine Needle Filler (TPNF), Untreated Pine Needle Filler (UPNF) procured from the paper mill. Sample preparation was carried out in an injection molding machine. Tensile properties of the samples were measured on Shimadzu UTM. TGA and DTG were carried out simultaneously by using a Perkin Elmer Thermal Analyzer. Structural characterization was done using FTIR spectrophotometer. The flame retardancy of TPNF and UPNF reinforced polypropylene composites were characterized by the UL-94 test. The composite intact fracture surface morphology was analyzed on a field emission scanning electron microscope.

  • gamesKEYWORDS

    Composites; TGA; DTG; Field Emission Scanning Electron microscopy; FE-SEM; Flammability.

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☑ Stability criterion for time-delay 3-dimension damped Mathieu equation

Yusry O.El-Dib

Department of Mathematics, Faculty of Education,Ain Shams University, Roxy, Egypt

  • subtitlesABSTRACT

    In the present work, the investigation of the dynamics of three dimensions Mathieu equations containing periodic terms as well as the delayed parameters. Mathieu equations included the influence of damping terms and the coupled system involves both delayed and non-delay terms. The system is proposed as an extension of delayed two coupled Mathieu-type equations to higher dimensions, with emphasis on how resonance between the internal frequencies leads to a loss of stability. The method of multiple scales is used to examine the islands of stability near the resonance cases. The transition curves are analyzed using the method of harmonic balance, and we find we can use this method to easily predict the `resonance curves' from which bands of instability emanate. We note that the delayed higher dimension of the parametric excitation has a great interest and application to the design of nuclear accelerators.

  • gamesKEYWORDS

    Three dimensions Mathieu equations; resonance curves; parametric excitation.

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