644 research outputs found
The generalized-kinetic modelling of a multicomponent "real life" fluid by means of a single distribution function,
No full textThe generalized-kinetic based equilibrium distribution functions for composite particles
No full textAn introduction to microplastics, and its sampling processes and assessment techniques
No full textMicroplastics have gained much attention in the past decade as a major environmental threat and thus, the amount of research work done with regard to microplastic assessment has increased drastically. This book chapter provides an overview on microplastics, its prevalence in our environment, and trends in collection and assessment. In Section 9.1, the book chapter gives an introduction on the definition of microplastics, its origin, and possible health-related impacts that could be caused by microplastics. Sections 9.2 and 9.3 detail about the sample collection techniques used currently for collection of samples from different environmental compartments, and separation techniques associated to different environmental samples, respectively. The process of separation is followed by different sample digestion techniques to dissolve the organic layers or biofilm accumulation in the surface of microplastics. The techniques have been discussed in Section 9.4. Finally, the various methods of identification, along with its advantages and disadvantages have been discussed in Section 9.5
AFM current-imaging study for current density through nanocrystalline silicon dots embedded in SiO2
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Chemically fashioned ZnO nanowalls and their potential application for potentiometric cholesterol biosensor
No full textChemically fashioned zinc oxide (ZnO) nanowalls on aluminum wire have been characterized and utilized to fabricate a potentiometric cholesterol biosensor by an electrostatic conjugation with cholesterol oxidase. The sensitivity, specificity, reusability, and stability of the conjugated surface of ZnO nanowalls with thickness of similar to 80 nm have been investigated over a wide logarithmic concentrations of cholesterol electrolyte solution ranging from 1x10(-6)-1x10(-3) M. The presented biosensor illustrates good linear sensitivity slope curve (similar to 53 mV/decade) corresponding to cholesterol concentrations along with rapid output response time of similar to 5 s.Original Publication:M.Q. Israr, J.R. Sadaf, Omer Nur, Magnus Willander, S. Salman and B. Danielsson, Chemically fashioned ZnO nanowalls and their potential application for potentiometric cholesterol biosensor, 2011, Applied Physics Letters, (98), 25, 253705.http://dx.doi.org/10.1063/1.3599583Copyright: American Institute of Physicshttp://www.aip.org
The chemically reduced CuO-Co3O4 composite as a highly efficient electrocatalyst for oxygen evolution reaction in alkaline media
No full textThe fabrication of efficient, alkaline-stable and nonprecious electrocatalysts for the oxygen evolution reaction is highly needed; however, it is a challenging task. Herein, we report a noble metal-free advanced catalyst, i.e. the chemically reduced mixed transition metal oxide CuO-Co3O4 composite, with outstanding oxygen evolution reaction activity in alkaline media. Sodium borohydride (NaBH4) was used as a reducing agent for the mixed transition metal oxide CuO-Co3O4. The chemically reduced composite carried mixed valence states of Cu and Co, which played a dynamic role in driving an excellent oxygen evolution reaction process. The X-ray photo-electron spectroscopy (XPS) study confirmed high density of active sites in the treated sample with a large number of oxygen vacancies. The developed electrocatalyst showed the lowest overpotential of 144.5 mV vs. the reversible hydrogen electrode (RHE) to achieve the current density of 40 mA cm-2 and remained stable for 40 hours throughout the chronoamperometry test at the constant potential of 1.39 V vs. RHE. Moreover, the chemically reduced composite was highly durable. Electrochemical impedance spectroscopy (EIS) confirmed the low charge transfer resistance of 13.53 ohms for the chemically reduced composite, which was 50 and 26 times smaller than that of Co3O4 and untreated CuO-Co3O4, respectively. The electrochemically active surface area for the chemically reduced composite was found to be greater than that for pristine CuO, Co3O4 and untreated pristine CuO-Co3O4. These findings reveal the possibility of a new gateway for the capitalization of a chemically reduced sample into diverse energy storage and conversion systems such as lithium-ion batteries and supercapacitors
Willander (Birth, 1874-12-29)
No full textAddress: 9 Providence St.2519/Pg.65/1874/M W/Germany/Germany/Mary Fischer, Mid.Original record filed in drawer labeled 'WILGAMS-WILLIAMS'
Glocuse detection with a commercial MOSFET using ZnO nanowires extended gate
No full textZinc oxide (ZnO) nanowires were grown on a silver (Ag) wire with a diameter of approximately 250 m and used in an electrochemical sensor. The enzyme glucose oxidase (GOD) was immobilized on the ZnO nanowires and the silver wire was connected directly to the gate of a MOSFET. Upon exposure to glucose (1-100 M) the electrochemical response from the glucose oxidase induced a stable measurable voltage change on the gate leading to a strong modulation of the current through the MOSFET. For a sensor with uniform ZnO nanowires functionalized with GOD a fast response time of less than 100 ms, was demonstrated. The effect of the uniformity of the ZnO nanowires on the sensing property was also investigated. The extended gate arrangement facilitated glucose detection in small sample volumes and made it possible to demonstrate the present sensor concept using a standard low threshold MOSFET. The extended gate MOSFET sensor approach demonstrates the possibility and potential of the use of nano-structures coupled to standard electronic components for biosensing applications.©2009 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. Syed M. Usman Ali, Omer Nour, Magnus Willander and Bengt Danielsson, Glocuse detection with a commercial MOSFET using ZnO nanowires extended gate, 2009, IEEE Transaction on Nanotechnology, (8), 6, 678-683.http://dx.doi.org/10.1109/TNANO.2009.201995
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