ORCID Profile
0000-0002-8244-1816
Current Organisation
GNS Science Ltd
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Publisher: AIP
Date: 2013
DOI: 10.1063/1.4802337
Publisher: IOP Publishing
Date: 04-02-2011
DOI: 10.1088/0957-4484/22/11/115602
Abstract: Magnetic nanoclusters have novel applications as magnetic sensors, spintronic and biomedical devices, as well as applications in more traditional materials such as high-density magnetic storage media and high performance permanent magnets. We describe a new synthesis protocol which combines the advantages of ion implantation and electron beam annealing (EBA) to produce surface iron nanoclusters. We compare the structure, composition and magnetic properties of iron nanoclusters fabricated by low dose 15 keV Fe implantation into SiO(2) followed by 1000 °C EBA or furnace annealing. Atomic force microscopy (AFM) and high resolution transmission electron microscopy (HRTEM) images together with superconducting quantum interference device (SQUID) magnetometry measurements show that only EBA leads to the rapid formation of surface crystalline Fe spherical nanoclusters, showing magnetic moments per Fe atom comparable to that of bulk bcc Fe and superparamagnetic properties. We propose a fabrication mechanism which includes e-beam enhanced desorption of SiO(2). This method has potential for fabricating nanoscale magnetic sensors integrated in microelectronic devices.
Publisher: Elsevier BV
Date: 10-2017
Publisher: Elsevier BV
Date: 09-2011
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2010
DOI: 10.3109/03093640903476802
Abstract: Orthoses are commonly prescribed for the management of spasticity but their neurophysiologic effect on spasticity remains unsubstantiated. The purpose of this study was to investigate the effect of three tone-reducing devices (dynamic foot orthosis, muscle stretch, and orthokinetic compression garment) on soleus muscle reflex excitability while standing in patients with spasticity following stroke. A repeated measures intervention study was conducted on 13 patients with stroke selected from a s le of convenience. A custom-made dynamic foot orthosis, a range of motion walker to stretch the soleus muscle and class 1 and class 2 orthokinetic compression garments were assessed using the ratio of maximum Hoffmann reflex litude to maximum M-response litude (Hmax:Mmax) to determine their effect on soleus muscle reflex excitability. Only 10 subjects were able to complete the testing. There were no significant treatment effects for the interventions (F=1.208, df=3.232, p=0.328) however, when analyzed subject-by-subject, two subjects responded to the dynamic foot orthosis and one of those two subjects also responded to the class 1 orthokinetic compression garment. Overall, the results demonstrated that the tone-reducing devices had no significant effect on soleus reflex excitability suggesting that these tone-reducing orthotic devices have no significant neurophysiologic effect on spasticity.
Publisher: Elsevier BV
Date: 10-2008
DOI: 10.1016/J.SCITOTENV.2008.05.039
Abstract: Over the past decade, member states of the Regional Co-operation Agreement (RCA), an intergovernmental agreement for the East Asia and Pacific region under the auspices of the IAEA with the assistance of international organizations and financial institutions such as the World Bank and the Asian Development Bank, have started to set in place policies and legislation for air pollution abatement. To support planning and evaluate the effectiveness of control programs, data are needed that characterizes urban air quality. The focus of this measurement program describe in this report is on size segregated particulate air pollution. Such airborne particulate matter can have a significant impact on human health and urban visibility. These data provide the input to receptor models that may permit the mitigation of these impacts by identification and quantitative apportionment of the particle sources. The aim of this report is to provide an overview of the measurements of concentrations and composition of particulate air pollution in two size fractions across the participating countries. For many of the large cities in this region, the measured particulate matter concentrations are greater than air quality standards or guidelines that have been adopted in developed countries.
Publisher: Springer Science and Business Media LLC
Date: 12-2006
Publisher: IOP Publishing
Date: 30-06-2011
Publisher: Elsevier BV
Date: 03-2000
Publisher: American Physical Society (APS)
Date: 28-11-2005
Publisher: Elsevier BV
Date: 02-2012
Publisher: Springer Science and Business Media LLC
Date: 12-2005
Publisher: Springer Science and Business Media LLC
Date: 31-08-2011
Publisher: World Scientific Pub Co Pte Lt
Date: 20-12-2001
DOI: 10.1142/S0217984901003330
Abstract: Complex bis terthiophene porphyrin conducting polymers were used to investigate the uptake of zinc into the freebase porphyrin unit after polymerisation by acquiring depth profiles using Rutherford Backscatting Spectrometry (RBS) analysis. Issues such as the influence of the support material and extent of polymer oxidation on the dispersion of the counter ions through the polymer films are of importance. Gaining knowledge of the dispersion of counter ions provides new insights into the redox mechanisms for conductive polymers. The results were compared to those obtained from a s le where zinc was coordinated to the porphyrin prior to the polymerisation process. Unexpectedly high concentration of both nitrogen and oxygen were found which could be due to evidence of the trapped cations from the electrolyte ( (Bu) 4 N + ), and trapped water molecules, within the polymer films. The chlorine concentrations help to understand the dispersion of the perchlorate counter ion throughout the polymer films, and the combination of both RBS and Proton Induced X-ray Emission (PIXE) show that trace element impurities can be detected using ion beam analysis which other analytical techniques are unable to do.
Publisher: Elsevier BV
Date: 02-2001
Publisher: Springer Science and Business Media LLC
Date: 12-08-2011
Publisher: Springer Science and Business Media LLC
Date: 28-04-2010
Publisher: American Institute of Physics
Date: 2009
DOI: 10.1063/1.3203224
Publisher: Taiwan Association for Aerosol Research
Date: 2012
No related grants have been discovered for Andreas Markwitz.