Double-walled carbon nanotube based carbon paste electrode as xanthine biosensor

We describe the first usage of a double walled carbon nanotube (DWCNT) modified carbon paste electrode as biosensor transducer. Xanthine was chosen as a substrate for evaluation of the electrode performance. Proper amount of DWCNT and xanthine oxidase enzyme were mixed with proper amount of graphite and mineral oil for attaining the xanthine biosensor. Results were compared with previous work that includes multi-walled carbon nanotube and single-wall carbon nanotube based carbon paste electrode xanthine biosensors. A linearity was obtained in the concentration range between 2–50 μM xanthine under the response time of 150 s with the equation of y?=?0.0441x + 0.2013 and RSD value of 4.20%. This system was applied to the determination of xanthine in canned tuna fish samples and recovery was calculated as 99.20%?±?0.07.     

When is the Range of a Multiplier on a Banach Algebra Closed?

In this paper we prove the Theorem: Let A be a Banach algebra with a bounded approximate identity (=BAI) such that every proper closed ideal of A is contained in a proper closed ideal with a BAI. Then a multiplier T:A → A has a closed range iff T factors as a product of an idempotent multiplier and an invertible multiplier.This work of the author is supported in part by the Turkish Academy of Sciences.     

Quantization of constrained systems: A comparative look at three methods

Constrained Hamiltonian systems are investigated using three different methods: Hamilton-Jacobi, Batalin-Fradkin-Tyutin and gauge unfixing methods. The abelian Proca model is analyzed and the involutive Hamiltonian is obtained by the three methods.     

Cosmology with rolling tachyon

We examine the possibility of rolling tachyon to play the dual role of inflaton at early epochs and dark matter at late times. We argue that enough inflation can be generated with the rolling tachyon either by invoking the large number of branes or brane world assisted inflation. However, reheating is problematic in this model. On leave from Jamia Millia Islamia, New Delhi 110 025, India     

Die Einwirkung von Jod auf Quecksilberoxydul- und Quecksilberoxydsulfat

Ohne Zusammenfassung     

A visual programming system for defining behavior in simulation models of manufacturing systems

A visual programming system is described that allows the modeler full flexibility in defining the behavior of a manufacturing system simulation model. Decision-making behavior of objects in the simulation can be viewed by watching an animation of the system layout, viewing function block diagrams of rules that govern behavior, or noting the progress of an object in carrying out sequences of activities that are pictured as operation networks. Rules, elemental operations and operation networks are structured and associated with particular objects, groups of objects, and locations on the manufacturing system layout. The objective of this system is to reduce the time and expense required to construct and modify models, given that manufacturing system data have been collected.     

Buchbesprechungen

Ohne Zusammenfassung     

Buchbesprechungen

Ohne Zusammenfassung     

Divergence theorems in semi-Riemannian geometry

Two forms of divergence theorem for semi-Riemannian manifolds are proven. This work is a part of the author's MS Thesis.