77 research outputs found

    Policies and Procedures for the Termination of War Contracts

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    The concept of recognition and biofunctionality has attracted increasing interest in the fields of chemistry and material sciences. Advances in the field of nanotechnology for the synthesis of desired metal oxide nanostructures have provided a solid platform for the integration of nanoelectronic devices. These nanoelectronics-based devices have the ability to recognize molecular species of living organisms, and they have created the possibility for advanced chemical sensing functionalities with low limits of detection in the nanomolar range. In this review, various metal oxides, such as ZnO-, CuO-, and NiO-based nanosensors, are described using different methods (receptors) of functionalization for molecular and ion recognition. These functionalized metal oxide surfaces with a specific receptor involve either a complex formation between the receptor and the analyte or an electrostatic interaction during the chemical sensing of analytes. Metal oxide nanostructures are considered revolutionary nanomaterials that have a specific surface for the immobilization of biomolecules with much needed orientation, good conformation and enhanced biological activity which further improve the sensing properties of nanosensors. Metal oxide nanostructures are associated with certain unique optical, electrical and molecular characteristics in addition to unique functionalities and surface charge features which shows attractive platforms for interfacing biorecognition elements with effective transducing properties for signal amplification. There is a great opportunity in the near future for metal oxide nanostructure-based miniaturization and the development of engineering sensor devices

    Responding to Agency Avoidance of OIRA

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    Concerns have recently been raised that US federal agencies may sometimes avoid regulatory review by the White House Office of Information and Regulatory Affairs (OIRA). In this article, we assess the seriousness of such potential avoidance, and we recommend a framework for evaluating potential responses. After summarizing the system of presidential regulatory oversight through OIRA review, we analyze the incentives for agencies to cooperate with or avoid OIRA. We identify a wider array of agency avoidance tactics than has past scholarship, and a wider array of corresponding response options available to OIRA, the President, Congress, and the courts. We argue that, because the relationship between agencies and OIRA involves ongoing repeat player interactions, some of these avoidance tactics are less likely to occur (or to succeed) than has previously been alleged, and others are more likely; the difference depends significantly on how easy it is for OIRA to detect avoidance, and for OIRA, the courts, and others to respond. Further, we note that in this repeat player relationship, responses to agency avoidance tactics may induce further strategic moves and countermoves. Thus we further argue that the optimal response may not always be to try to eliminate the avoidance behavior; some avoidance may be worth tolerating where the benefits of trying to reduce agency avoidance would not justify the costs of response options and countermoves. We therefore conclude that responses to agency avoidance should be evaluated in a way similar to what OIRA asks of agencies evaluating proposed regulations: by weighing the pros and cons of alternative response options (including no action)

    With No Deliberate Speed: The Segregation of Roma Children in Europe

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    In this study, by taking the advantage of both inorganic ZnO nanoparticles and the organic material chitosan as a composite seed layer, we have fabricated well-aligned ZnO nanorods on a gold-coated glass substrate using the hydrothermal growth method. The ZnO nanoparticles were characterized by the Raman spectroscopic techniques, which showed the nanocrystalline phase of the ZnO nanoparticles. Different composites of ZnO nanoparticles and chitosan were prepared and used as a seed layer for the fabrication of well-aligned ZnO nanorods. Field emission scanning electron microscopy, energy dispersive X-ray, high-resolution transmission electron microscopy, X-ray diffraction, and infrared reflection absorption spectroscopic techniques were utilized for the structural characterization of the ZnO nanoparticles/chitosan seed layer-coated ZnO nanorods on a gold-coated glass substrate. This study has shown that the ZnO nanorods are well-aligned, uniform, and dense, exhibit the wurtzite hexagonal structure, and are perpendicularly oriented to the substrate. Moreover, the ZnO nanorods are only composed of Zn and O atoms. An optical study was also carried out for the ZnO nanoparticles/chitosan seed layer-coated ZnO nanorods, and the obtained results have shown that the fabricated ZnO nanorods exhibit good crystal quality. This study has provided a cheap fabrication method for the controlled morphology and good alignment of ZnO nanorods, which is of high demand for enhancing the working performance of optoelectronic devices

    Electrochemical l-Lactic Acid Sensor Based on Immobilized ZnO Nanorods with Lactate Oxidase

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    In this work, fabrication of gold coated glass substrate, growth of ZnO nanorods and potentiometric response of lactic acid are explained. The biosensor was developed by immobilizing the lactate oxidase on the ZnO nanorods in combination with glutaraldehyde as a cross linker for lactate oxidase enzyme. The potentiometric technique was applied for the measuring the output (EMF) response of l-lactic acid biosensor. We noticed that the present biosensor has wide linear detection range of concentration from 1 × 10−4–1 × 100 mM with acceptable sensitivity about 41.33 ± 1.58 mV/decade. In addition, the proposed biosensor showed fast response time less than 10 s, a good selectivity towards l-lactic acid in presence of common interfering substances such as ascorbic acid, urea, glucose, galactose, magnesium ions and calcium ions. The present biosensor based on immobilized ZnO nanorods with lactate oxidase sustained its stability for more than three weeks

    The phenomenon of vehicle park brake rollaway

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    When a vehicle is parked on a slope with hot brakes, what appears to be a sufficient parking brake action can sometimes become insufficient. When the brakes cool down, the braking force reduces due to relaxation of the entire parking brake system, and the vehicle may start to move, leading to obvious catastrophic consequences. This phenomenon is known as vehicle rollaway. This thesis describes the problem in detail and postulates a mechanism that accounts for the occurrence of the rollaway event on vehicles using integrated rear callipers. Different testing methods are presented that are used to investigate the propensity of a vehicle's parking brake system to rollaway. These include on-vehicle evaluations and laboratory based measurements. A description is given of a novel dynamometer facility that was developed for this research that is capable of testing vehicle parking brake systems for rollaway. Two mathematical modelling techniques are presented that demonstrate how the parking brake system parameters influence the likelihood of rollaway occurring. A finite element model was used to simulate the change in contact pressure at the frictional interface during a rollaway event. A numerical model was also used to predict the change in torque developed by a parking brake system cooling from an initial elevated temperature. The change in clamp load at the frictional interface was modelled using an essentially I-D quasi-static system that showed how the stiffness and the thermal properties of the system qualitatively affect the phenomenon. The research found that rollaway does not always start with a uniform motion, but with a stick/slip motion. The likelihood of rollaway occurring was found to be directly linked to the temperature of the brake when the vehicle is parked. Rollaway can be reduced by lowering the initial temperature of the brake prior to parking. Rollaway can also be reduced by increasing the input load to the system when applying the parking brake. The research identifies the key design parameters of the brake system components whose values require close control within the real system if rollaway is to be avoided.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    A Selective Iodide Ion Sensor Electrode Based on Functionalized ZnO Nanotubes

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    In this research work, ZnO nanotubes were fabricated on a gold coated glass substrate through chemical etching by the aqueous chemical growth method. For the first time a nanostructure-based iodide ion selective electrode was developed. The ZnO nanotubes were functionalized with miconazole ion exchanger and the electromotive force (EMF) was measured by the potentiometric method. The iodide ion sensor exhibited a linear response over a wide range of concentrations (1 × 10−6 to 1 × 10−1 M) and excellent sensitivity of –62 ± 1 mV/decade. The detection limit of the proposed sensor was found to be 5 × 10−7 M. The effects of pH, temperature, additive, plasticizer and stabilizer on the potential response of iodide ion selective electrode were also studied. The proposed iodide ion sensor demonstrated a fast response time of less than 5 s and high selectivity against common organic and the inorganic anions. All the obtained results revealed that the iodide ion sensor based on functionalized ZnO nanotubes may be used for the detection of iodide ion in environmental water samples, pharmaceutical products and other real samples

    Metal Oxide Nanosensors Using Polymeric Membranes, Enzymes and Antibody Receptors as Ion and Molecular Recognition Elements

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    The concept of recognition and biofunctionality has attracted increasing interest in the fields of chemistry and material sciences. Advances in the field of nanotechnology for the synthesis of desired metal oxide nanostructures have provided a solid platform for the integration of nanoelectronic devices. These nanoelectronics-based devices have the ability to recognize molecular species of living organisms, and they have created the possibility for advanced chemical sensing functionalities with low limits of detection in the nanomolar range. In this review, various metal oxides, such as ZnO-, CuO-, and NiO-based nanosensors, are described using different methods (receptors) of functionalization for molecular and ion recognition. These functionalized metal oxide surfaces with a specific receptor involve either a complex formation between the receptor and the analyte or an electrostatic interaction during the chemical sensing of analytes. Metal oxide nanostructures are considered revolutionary nanomaterials that have a specific surface for the immobilization of biomolecules with much needed orientation, good conformation and enhanced biological activity which further improve the sensing properties of nanosensors. Metal oxide nanostructures are associated with certain unique optical, electrical and molecular characteristics in addition to unique functionalities and surface charge features which shows attractive platforms for interfacing biorecognition elements with effective transducing properties for signal amplification. There is a great opportunity in the near future for metal oxide nanostructure-based miniaturization and the development of engineering sensor devices
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