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Faculty of Technology ePrints Service (67.790 recursos)

Repository of the Faculty of Technology of University of Lincoln.

Subject = J Technologies: J510 Materials Technology

Mostrando recursos 1 - 20 de 38

  1. Micro and nanomanufacturing: volume II

    Ahmed, Waqar; Jackson, Mark J.
    This book is a comprehensive treatment of micro and nanofabrication techniques, and applies established and research laboratory manufacturing techniques to a wide variety of materials. It is a companion volume to “Micro and Nanomanufacturing” (2007) and covers new topics such as aligned nanowire growth, molecular dynamics simulation of nanomaterials, atomic force microscopy for microbial cell surfaces, 3D printing of pharmaceuticals, microvascular coaptation methods, and more. The chapters also cover a wide variety of applications in areas such as surgery, auto components, living cell detection, dentistry, nanoparticles in medicine, and aerospace components. This is an ideal text for professionals working in...

  2. Channelled tablets: an innovative approach to accelerating drug release from 3D printed tablets

    Sadia, Muzna; Arafat, Basel; Ahmed, Waqar; Forbes, Robert E.; Alhnan, Mohamed A.
    Conventional immediate release dosage forms involve compressing the powder with a disintegrating agent that enables rapid disintegration and dissolution upon oral ingestion. Among 3D printing technologies, the fused deposition modelling (FDM) 3D printing technique has considerable potential for patient-speciTc dosage form. However, the use of FDM 3D printing in tablet manufacturing requires large portion of polymer, which slows down drug release through erosion and diffusion mechanisms. In this study, we demonstrate for the Trst time the use of a novel design approach of caplets with perforating channels to accelerate drug release from 3D printed tablets. This strategy has been implemented using a caplet design with perforating...

  3. Channelled tablets: an innovative approach to accelerating drug release from 3D printed tablets

    Sadia, Muzna; Arafat, Basel; Ahmed, Waqar; Forbes, Robert E.; Alhnan, Mohamed A.
    Conventional immediate release dosage forms involve compressing the powder with a disintegrating agent that enables rapid disintegration and dissolution upon oral ingestion. Among 3D printing technologies, the fused deposition modelling (FDM) 3D printing technique has considerable potential for patient-speciTc dosage form. However, the use of FDM 3D printing in tablet manufacturing requires large portion of polymer, which slows down drug release through erosion and diffusion mechanisms. In this study, we demonstrate for the Trst time the use of a novel design approach of caplets with perforating channels to accelerate drug release from 3D printed tablets. This strategy has been implemented using a caplet design with perforating...

  4. Thermal synthesis of tetragonal zirconia nanopowders

    Athar, T.; Ko, T.; Lee, I.-M.; Ahmed, W.
    A new molecular precursor has been used to the synthesis of tetragonal zirconia at the nanoscale using a thermal route. A transparent gel was obtained by heating zirconium butoxide without using any solvent. The gel was subsequently calcinated in an inert atmosphere to form monodispersible powder. Various techniques have been used to characterise the tetragonal zirconia nanoparticles. The UV absorption edge is very sensitive to the particle size, shape and surface morphology. Tetragonal ZrO 2 was obtained at 350 °C with particle size (2 nm) as supported by XRD and TEM studies. It was concluded that the temperature has a...

  5. Synthesis of MgO nanopowder via non aqueous sol-gel method

    Athar, T.; Hakeem, A.; Ahmed, W.
    Magnesium Oxide (MgO) is an attractive material for a wide range of application such as catalysis, treatment waste and an additive to paints, refractory materials and superconductive materials. It yield significant advantage when it is manufactured and used on a nanoscale dimensions. In this study cubic MgO nanoparticles were prepared by using non-aqueous sol-gel process with good morphology and with limited surface area properties and monodispersity. The nanoparticle was characterized by various analytical techniques such as TEM, SEM, XRD, TGA/DTA, FT-IR and Raman spectroscopy. The average particle size with 43 nm and surface area of 2.81 m 2/g was obtained....

  6. Nanotechnology and the future of dentistry

    Subramani, K.; Ahmed, Waqar
    This chapter provides an overview of nanotechnology and its future applications in dentistry. In the field of medicine, nanotechnology has been applied in diagnosis, prevention, and treatment of diseases. Nanotechnology offers considerable scope in dentistry to improve dental treatment, care, and prevention of oral diseases. Nanotechnology has been in dentistry for tooth sealants and fillers that use nanosized particles to improve their strength, luster, and resist wear. Antimicrobial nanoparticles in restorative composite materials are used to prevent dental caries. Silver particles as antibacterial agents when used in fillers and toothpastes can retard bacterial growth and reduce tooth decay. It is...

  7. Controlling the morphology and material characteristics of electrospray generated calcium alginate microhydrogels

    Mehregan Nikoo, Alireza; Kadkhodaee, Rassoul; Ghorani, Behrouz; Razzaq, Hussam; Tucker, Nick
    Electrospraying nano- and micro-particle fabrication is a one-step, non-invasive process, which has application in encapsulating of thermosensitive functional, bioactive materials and cells and making microhydrogels. This study investigates the effect of various electrospraying process parameters on the characteristics of calcium alginate microhydrogel particles. The alginate solution concentration, CaCl2 coagulation bath concentration, voltage, nozzle diameter, distance between nozzle and collecting bath (D), alginate delivery pressure (∼H) were examined. The best droplet formation rate, in non-disperse dripping mode, was obtained at 8 kV using a 500 μm inner diameter nozzle tip, D = 8 cm, H = 20 cm. Morphology, swelling behaviour and texture analysis of the particles which were...

  8. Characterizing Defects Responsible for Charge Transport Characteristics at Interfaces of Nano-Thick Materials Stacks

    Bersuker, Gennadi; Watkins, Matthew B.; Shluger, Alexander L.
    Major functioning blocks in modern devices employed in a variety of applications (electronics, energy harvesting, sensors, etc.) comprise of stacks of nm-thin layers of dielectric materials in contact with conductive electrodes (semiconductors, metals). The performance and reliability of these devices are affected by charge transfer characteristics of these multilayer stacks. We discuss collaboration between electrical measurements and computational modeling leading to identification of defects responsible for degradation phenomena in nm-thin dielectric films employed as gate dielectrics in metal oxide field effect transistors.

  9. Manufacture and characterization of Asiatic acid non-ionic surfactant nanocapsules for anticancer therapy

    Hussein, I.; Stasik, A.; Wan, K.-W.; Ahmed, W.; Phoenix, D. A.; Ahmed, E.; Jackson, M.; Elhissi, A.
    Asiatic acid is a very promising anticancer drug; however, its poor water solubility is a serious limitation. In this study, non-ionic surfactant nanocapsules were manufactured using sorbitan monostearate (Span 60) and cholesterol (1:1) to entrap and solubilize Asiatic acid. Niosome nanocapsules with or without Asiatic acid were prepared using thin film hydration method by hand shaking at 50°C followed by bath and probe sonication. The probe-sonicated Asiatic acid nanocapsules had a hydrodynamic size of 179 ± 4.4 nm compared to 264 ±58.4 nm for the nanocapsules containing no Asiatic acid. When no drug was included, the nanocapsules had a zeta...

  10. Manufacture of Paclitaxel proliposomes: a simple approach to generating anticancer liposomes

    Devi, B. R.; Phoenix, D. A.; Ahmed, W.; Crean, S. J.; Jackson, M.; Elhissi, A.
    Proliposomes were manufactured by coating sucrose carrier particles with a lipid phase comprising the phospholipid Phospholipon® 90H and the anticancer drug Paclitaxel. Hydration of the proliposomes with deionized water followed by probe-sonication generated nano-sized liposomes (160.50 nm) with slightly negative zeta potential (-0.79 mV). The entrapment efficiency of Paclitaxel was as high as 88.54 (1.93 mgs drug per 100 mg lipid). The solubility of Paclitaxel in our study was 965.16 μg/ml, which is almost 10,000 times higher than the literature reported solubility of this drug. Overall, using the proliposome manufacturing approach we have developed a Paclitaxel liposome formulation with highly...

  11. Air-jet and vibrating-mesh nebulization of niosomes generated using a particulate-based proniosome technology

    Elhissi, A.; Hidayat, K.; Phoenix, D. A.; Mwesigwa, E.; Crean, S.; Ahmed, W.; Faheem, A.; Taylor, K. M. G.
    The aerosol properties of niosomes were studied using Aeroneb Pro and Omron MicroAir vibrating-mesh nebulizers and Pari LC Sprint air-jet nebulizer. Proniosomes were prepared by coating sucrose particles with Span 60 (sorbitan monostearate), cholesterol and beclometasone dipropionate (BDP) (1:1:0.1). Nano-sized niosomes were produced by manual shaking of the proniosomes in deionized water followed by sonication (median size 236 nm). The entrapment of BDP in proniosome-derived niosomes was higher than that in conventional thin film-made niosomes, being 36.4 and 27.5 respectively. All nebulizers generated aerosols with very high drug output, which was 83.6 using the Aeroneb Pro, 85.5 using the Pari...

  12. Comparison between FTIR and XPS characterization of amino acid glycine adsorption onto diamond-like carbon (DLC) and silicon doped DLC

    Ahmed, M. H.; Byrne, J. A.; McLaughlin, J. A. D.; Elhissi, A.; Ahmed, W.
    Diamond-like carbon (DLC) coatings are extremely useful for creating biocompatible surfaces on medical implants. DLC and silicon doped DLC synthesized on silicon wafer substrate by using plasma enhanced chemical vapour deposition (PECVD). The adsorption of glycine onto prepared samples has been investigated with a range of surface analysis techniques. The effects of surface morphology on the interaction of glycine with doped and undoped DLC films have been investigated. The chemical composition of the surface before and after adsorption was analyzed using X-ray photoelectron spectroscopy (XPS). For undoped DLC the spectra show peaks at 285 eV (C 1s), 532 eV (O...

  13. A facile one-step approach to synthesizing ZnO/graphene composites for enhanced degradation of methylene blue under visible light

    Ahmad, M.; Ahmed, E.; Hong, Z. L.; Xu, J. F.; Khalid, N. R.; Elhissi, A.; Ahmed, W.
    A series of visible light-responsive ZnO/graphene composite photocatalysts were successfully synthesized by a facile single step solvothermal method, using ethylene glycol as a solvent and a reducing agent. Successful deposition of wurtzite ZnO nanoparticles onto the graphene was confirmed by high resolution transmission electron microscope (HR-TEM), transmission electron microscope (TEM), scanning electron microscope (SEM) with energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). UV-vis diffuse reflectance spectroscopy (DRS) showed that the as-prepared ZnO/graphene composite photocatalysts had enhanced visible light absorption and also exhibited a red-shift of the band-edge as compared...

  14. A study of the effects of sodium halides on the performance of air-jet and vibrating-mesh nebulizers

    Najlah, M.; Vali, A.; Taylor, M.; Arafat, B. T.; Ahmed, W.; Phoenix, D. A.; Taylor, K. M. G.; Elhissi, A.
    The influence of sodium halide electrolytes on aerosols generated from the Aeroneb Pro vibrating mesh nebulizer and the Sidestream air-jet nebulizer has been evaluated. Fluids with a range of concentrations of Na halides (i.e. NaF, NaCl, NaBr and NaI) were used as nebulizer solutions and their effect on aerosol properties such as total aerosol output, fine particle fraction (FPF), volume median diameter (VMD) and predicted regional airway deposition were investigated. For both nebulizers, the inclusion of electrolyte significantly enhanced the aerosol properties compared with HPLC grade (deionized) water. Aerosol output, FPF and aerosol fraction less than 2.15 μm were directly...

  15. Structural, optical and photocatalytic properties of hafnium doped zinc oxide nanophotocatalyst

    Ahmad, M.; Ahmed, E.; Hong, Z. L.; Iqbal, Z.; Khalid, N. R.; Abbas, T.; Ahmad, I.; Elhissi, A. M.; Ahmed, W.
    A series of novel hafnium (Hf) doped ZnO nanophotocatalyst were synthesized using a simple sol-gel method with a doping content of up to 6 mol. The structure, morphology and optical characteristics of the photocatalysts were characterized by XRD, SEM, TEM, FTIR, XPS, DRS and PL spectroscopy. The successful synthesis and chemical composition of pure and doped ZnO photocatalysts were confirmed by XRD and XPS. DRS confirmed that the spectral responses of the photocatalysts were shifted towards the visible light region and showed a reduction in band gap energy from 3.26 to 3.17 eV. Fluorescence emission spectra indicated that doped ZnO...

  16. Enhancing visible light responsive photocatalytic activity by decorating Mn-doped ZnO nanoparticles on graphene

    Ahmad, M.; Ahmed, E.; Ahmed, W.; Elhissi, A.; Hong, Z. L.; Khalid, N. R.
    Novel visible-light-responsive Mn-doped ZnO/Graphene nanocomposite photocatalysts were synthesized using a facile single step solvothermal method. A range of techniques including X-Ray diffraction (XRD), a high resolution transmission electron microscope (HR-TEM), a transmission electron microscope (TEM), a scanning electron microscope (SEM) with energy dispersive X-ray analysis (EDX), Fourier transform infrared spectroscopy (FTIR), Brunauer Emmett Teller (BET) surface area analyzer and X-ray photoelectron spectroscopy (XPS) were employed to characterize the as-prepared composites. UV-visible diffuse reflectance spectroscopy (DRS) was used to study the optical properties, which confirmed that the spectral responses of the nanocomposite catalysts were gradually extended to the visible-light region as...

  17. Commercialization of nanotechnologies: technology transfer from university research laboratories

    Jackson, M. J.; Ahmed, W.; Whitt, M.; Handy, R.; Robinson, G. M.; Whitfield, M. D.; Morrell, J. S.
    The commercialization of nanotechnology from university spin-off companies is viewed as critical for the sustainable development of tertiary-level technologies. This chapter outlines the roles of venture capitalists, government, academic institutions, and entrepreneurs in providing society with nanotechnology companies that turn science into money. The chapter also explains how the technology is transferred in the marketplace through patents, trade secrets, and copyrights, and allows the academic entrepreneur to understand the role of consumers and markets. © 2015 Elsevier Inc. All rights reserved.

  18. Nanocoatings in medicine: antiquity and modern times

    Yousaf, S.; Alhnan, M. A.; Abdallah, A.; Abdallah, B.; Khan, I.; Ahmed, W.
    Whilst nanotechnology particularly focuses upon the power of working at the nanoscale, often with reference to particles or atoms, nano-based materials or nanocoatings upon ordinary classed materials, are equally as potent. Nanocoatings are prevalent across a multitude of disciplines ranging from engineering through to medicine. A wide range of materials and techniques has been employed to produce nanocoatings for a given purpose. This chapter explores a number of aspects of nanocoatings and provides a brief overview of the origins and development of coating as a concept. It also delves into the concept of nanocoating, examining exactly what is a nanocoating...

  19. Analysis of the effects of micromachining using nanostructured cutting tools

    Jackson, M. J.; Whitfield, M. D.; Robinson, G. M.; Ahmed, W.; Morrell, J. S.
    The analysis of the high-speed mechanical micromilling process is described in this chapter. The present work not only compares computational approaches to the solution of shear plane and tool face temperatures, but also explains why there is a difference when calculating temperatures generated during the micromachining process. The analysis shows that the computed temperature of the shear plane never exceeds 35°C when micromilling at spindle speeds approximately 310,000 rpm. Machining AISI 1040 steel at significantly high speeds presents significant challenges to prevent the accelerated wear of the cutting tool that is caused by the frictional interactions between chip and tool...

  20. Micro- and nanomachining

    Jackson, M. J.; Robinson, G. M.; Whitfield, M. D.; Ahmed, W.; Morrell, J. S.
    Advances in miniaturization have led to the understanding and development of small-scale components that require advanced machining techniques in order to achieve the tolerances and feature sizes required at the micro- and nanoscales. The chapter focuses on general machining effects, size effects, nanomachining processes, and a comparison between micro- and nanomachining. An explanation of how size effects at the microscale affect the removal of material and its implication on shaping material at ever-diminishing scales is provided. © 2015 Elsevier Inc. All rights reserved.

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