An Improved Method of Organogenesis from Cotyledon Callus of Acacia sinuata (Lour.) Merr. using Thidiazuron

Shahzad Anwar,Ahmad Naseem,Anis Mohammad The Korean Society of Plant Biotechnology 2006 Plant molecular biology and biotechnology research Vol.8 No.1

An efficient protocol for in vitro multiple shoot bud induction and plant regeneration from mature green cotyledon derived callus tissues of Acacia sinuata has been developed. Callus formation occurs at all the concentrations of thidiazuron (TDZ) in Murashige and Skoog's (MS) medium, but 0.6 ${\mu}M$ proved to be the best with maximum callus formation frequency. Supplementation of TDZ in combination with indole-acetic acid (IAA) in MS media accelerates shoot bud organogenesis in differentiating callus tissues with 60-70% conversion of shoot buds into shoot Most efficient shoot organogenesis was recorded when TDZ induced calli were subcultured at different concentrations of 6-benzyla-denine (BA). Optimum shoot bud induction and plant regeneration from callus was achieved when 0.6 ${\mu}M$ (TDZ) induced calli were subcultured at 3.0 ${\mu}M$ (BA) where $16.6{\pm}0.74$ shoots/unit callus on obtained. Rooting in in vitro differentiated shoots was achieved when transferred to medium containing different concentration of indole-3-butyric acid (IBA) in full & half strength MS medium. The well rooted plantlets were hardened and transferred to net house with 90% survival rate.

Fabrication and optimization of Co<SUB>75</SUB>Fe<SUB>25</SUB> granular magnetic tunnel junctions

Saira RIAZ,Shahzad NASEEM 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.8

Structural and Magnetic Studies of Ni-doped ZnO Synthesized with Auto-combustion and Co-precipitation Techniques

Murtaza Saleem,Shahid Atiq,Shahzad Naseem,Saadat A. Siddiqi 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.60 No.10

Synthesis techniques strongly influence the various properties of diluted magnetic semiconductor materials. Auto-combustion and co-precipitation techniques were employed to prepare Zn0.95Ni0.05O samples. X-ray diffraction studies exhibited a phase with a pure wurtzite-type crystal structure in both samples. However, traces of nickel oxide were detected in the sample synthesized with the coprecipitation technique. The structural morphology was studied with scanning electron microscopy. Energy dispersive X-ray analysis confirmed the incorporation of Ni content into the zinc-oxide matrix. The decrease in resistivity with increasing temperature demonstrated a typical semiconducting behavior. Room-temperature ferromagnetism was detected only in the sample synthesized with the auto-combustion technique.

Electrochemical preparation and characterization of room temperature L10 ordered Co1<SUB>-x</SUB>Pt<SUB>x</SUB> thin films and nanowires

Saira RIAZ,Yb XU,Shahzad NASEEM 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.8

Morphology controlled facile synthesis of MnO2 adsorbents for rapid strontium removal

Umar Asim,Syed M. Husnain,Naseem Abbas,Faisal Shahzad,Abdul Rehman Khan,Tahir Ali 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.98 No.-

MnO2 nanostructures with three distinct architectures, namelyflower, balk and tube-like, have beensynthesized through a single step microwave assisted hydrothermal method at different reactiontemperatures (110 C, 140 C and 180 C). The characterization of as prepared MnO2 samples wereperformed by means of Fourier transform infrared spectroscopy, X-ray diffraction, scanning electronmicroscopy, and transmission electron microscopy. The N2 adsorption–desorption isotherms revealedthe higher specific surface area and porosity of theflower like MnO2 as compared to balk and tube-likeMnO2. The adsorption behavior of as prepared adsorbents was investigated towards Sr2+ radionuclide. Because of the hierarchal structure and the high surface area (62.64 m2/g), MnO2-110 depicted the bestSr2+ adsorption performance with maximum adsorption capacity of 52 mg/g at pH 6 as compared to otherMnO2 morphologies synthesized at 140 C and 180 C. The kinetic studies revealed that the adsorption ofSr2+ onto MnO2-110 followed the pseudo-first-order model whereas the adsorption equilibrium dataobeyed the Freundlich and Sips model. Moreover, the MnO2-110 adsorbent reached the steady statequickly ( 10 min) and is capable to bind Sr2+ in slightly acidic to alkaline solutions.

Sol–gel based phenolphthalein encapsulated heterogeneous silica–titania optochemical pH nanosensor

Shumaila Islam,Noriah Bidin,Saira Riaz,Shahzad Naseem 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.34 No.-

Thermally stable phenolphthalein encapsulated silica–titania nanomatrix is fabricated by sol–gelmethod for optochemical pH sensing. The particle size 56–121 nm is obtained with average surfaceroughness of 3.95 nm after the encapsulation of dye which is highly appropriate for optical and sensingapplications. High surface area value 218 m2/g, pore volume of 0.16 cm3/g and pore diameter of31.49 A˚ is obtained after encapsulation. Furthermore, the sensor response is optimized at pH 10. Fastresponse time 1–2 s, sensitivity with good reproducibility identify that the fabricated optochemicalnanosensor is challenging for the detection of pH at room temperature.

Modeling and preparation of practical optical filters

Muhammad H. Asghar,Muhammad Shoaib,Frank Placido,Shahzad Naseem 한국물리학회 2009 Current Applied Physics Vol.9 No.5

Multilayer bandpass and bandstop filters have been produced using electron beam evaporation. Initially bandstop filter is modeled with non absorbing zinc sulphide (ZnS) and zinc selenide (ZnSe). When the absorption data was incorporated for the said materials significant absorption was observed at shorter wavelengths of the spectral band restricting the practical usage of the filter. ZnS and ZnSe were then replaced by dispersive silicon dioxide (SiO2), tantalum penta oxide (Ta2O5) and titanium dioxide (TiO2) along with their absorption and the filters are optimized to get desired bandpass and bandstop data. Bandpass and bandstop filters with desired performance were experimentally characterized with two combinations SiO2/Ta2O5/glass and SiO2/TiO2/glass. The measured average transmission for both combination (bandpass) in the pass band was about 92% with T < 1% in the stop band. Slightly narrow bandwidth was observed for SiO2/TiO2/glass as compared to SiO2/Ta2O5/glass which is attributed to layers densification. Similarly Tavg ≽ 80% was achieved for two combinations of bandstop filters with T < 0.1% in the stop band. The structure and surface morphology of the prepared filters were characterized by X-ray diffraction and scanning electron microscopy. XRD analysis reveals amorphous structure. SEM analysis also reveals that the layers are compact and have good surface quality. Multilayer bandpass and bandstop filters have been produced using electron beam evaporation. Initially bandstop filter is modeled with non absorbing zinc sulphide (ZnS) and zinc selenide (ZnSe). When the absorption data was incorporated for the said materials significant absorption was observed at shorter wavelengths of the spectral band restricting the practical usage of the filter. ZnS and ZnSe were then replaced by dispersive silicon dioxide (SiO2), tantalum penta oxide (Ta2O5) and titanium dioxide (TiO2) along with their absorption and the filters are optimized to get desired bandpass and bandstop data. Bandpass and bandstop filters with desired performance were experimentally characterized with two combinations SiO2/Ta2O5/glass and SiO2/TiO2/glass. The measured average transmission for both combination (bandpass) in the pass band was about 92% with T < 1% in the stop band. Slightly narrow bandwidth was observed for SiO2/TiO2/glass as compared to SiO2/Ta2O5/glass which is attributed to layers densification. Similarly Tavg ≽ 80% was achieved for two combinations of bandstop filters with T < 0.1% in the stop band. The structure and surface morphology of the prepared filters were characterized by X-ray diffraction and scanning electron microscopy. XRD analysis reveals amorphous structure. SEM analysis also reveals that the layers are compact and have good surface quality.

Synthesis and characterization of multilayered sol–gel based plastic-clad fiber optic pH sensor

Shumaila Islam,Rosly Abdul Rahman,Zulkafli Bin Othaman,Saira Riaz,Shahzad Naseem 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.23 No.-

The fabrication and characterization of an optical fiber pH sensor for the detection range 3–11 are described. The sensing element consists of a combination of indicators encapsulated in mesoporous surfactant based hybrid matrix, which are deposited onto an uncladed plastic optical fiber. Stable, dense and uniform sol–gel cladding with more than 90% transparency in the visible range are observed. Roughness value 9.7–6.57 nm is obtained by AFM. Film thickness, refractive index, and porosity are found to vary with number of coatings, 70% porosity is determined with 116 nm thickness. The response of the sensor with third layer is observed in acid and basic medium.

Synthesis and characterization of hybrid matrix with encapsulated organic sensing dyes for pH sensing application

Shumaila Islam,Rosly Rahman,ZULKAFLI OTHAMAN,Saira Riaz,Shahzad Naseem 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.6

Films of multi-organic indicators, encapsulated in silica–titania hybrid matrix with CTAB, have beensynthesized using sol–gel dip coating method. Two types of stable,dense and uniform matrices wereannealed at a 150 ℃ within two time intervals 1 h and 2 h by using 0.1 M and 0.5 M indicatorconcentrations. Nanoparticles are uniformly distributed with size in the range from 15–28 nm. Matriceshave high surface area (418.18–441.30 m2/g), which has more capability to sense the broader pH range. Spectroscopic studies showed the establishment of heterogeneous chemical bonding which indicative ofstability of matrices with 69% porosity. The response of the sensor is optimum at pH 9.

Spin polarization and magneto-dielectric coupling in Al-modified thin iron oxide films -microwave mediated sol-gel approach

Sidra Khalid,Saira Riaz,Samia Naeem,Aseya Akbar,S. Sajjad Hussain,YB Xu,Shahzad Naseem 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.103 No.-

Production of single-phase materials with multifunctional properties is still a challenge faced by materialscientists. In addition, obtaining high spin polarization efficiency in the materials that exhibit multifunctionalproperties is a big issue. A novel approach is suggested in this work for obtaining multifunctionalityand spin polarization in the same material. This approach has combined the effect of microwave radiationsand aluminum (Al) doping in iron oxide thin films during synthesis. Combined effect of microwaveradiations and Al doping results in controlling / tuning the structural transitions in iron oxide thin films. Pristine and 2–10 wt% Al doped iron oxide thin films are prepared and studied in detail. Raman analysisshows that 2 and 4 wt% Al concentration results in c-Fe2O3 + Fe3O4 phase with 71.3% and 64.5% of c-Fe2O3content, respectively. XRD and Raman analyses confirm the transition from c-Fe2O3 to Fe3O4 thin films atAl concentrations of 6–10 wt%. Structural transformation shows that microwave radiations catalyzes thatAl3+ions to occupy the vacancies on B sites of iron oxide thus, lead to the formation of Fe3O4. Observationof Verwey transition ~ 126 K also supports the transition in phases of iron oxide with increase in saturationmagnetization from 251.3emu/cm3 (pristine films) to 405.6emu/cm3 (8 wt% Al concentration). Highdielectric constant of ~ 135.5 (log f = 5.0) is observed for 8 wt% Al concentration. Conductivity anddetailed impedance & modulus analyses depict Mott’s hopping phenomenon along with presence of differentrelaxation times. Coupling between magnetic and dielectric properties is observed at room temperature. Magnetoresistance curves indicate spin polarization efficiency of ~24%.