The effects of heat transfer on the exergy efficiency of an air-standard otto cycle

The exergy analysis of an air-standard Otto cycle with heat transfer loss is analyzed by using finite-time thermodynamics. The results showed that the heat transfer loss is responsible for a significant destruction of exergy. It is also shown that exergy efficiency and maximum power output increase with decreasing heat transfer loss. The results obtained in this paper may provide useful information for the maximum work available.     

Some topological and geometric properties of generalized Euler sequence space

In this paper, we introduce the Euler sequence space e ^r (p) of nonabsolute type and prove that the spaces e ^r (p) and l(p) are linearly isomorphic. Besides this, we compute the α-, β- and γ-duals of the space e ^r (p). The results proved herein are analogous to those in [ALTAY, B.—BASŠAR, F.: On the paranormed Riesz sequence spaces of non-absolute type, Southeast Asian Bull. Math. 26 (2002), 701–715] for the Riesz sequence space r ^q (p). Finally, we define a modular on the Euler sequence space e ^r (p) and consider it equipped with the Luxemburg norm. We give some relationships between the modular and Luxemburg norm on this space and show that the space e ^r (p) has property (H) but it is not rotund (R).     

A general model for batch building processes under the timeout and capacity rules

In manufacturing systems, batch building processes are very common, as goods are often transported or processed in batches and must therefore be collected before these transport or processing steps can occur. In this paper, we present a method for the performance analysis of general batch building processes in material flow systems under the timeout and capacity rules. The proposed model allows for stochastic collecting times and incorporates no restrictions with respect to the number of arriving units and their interarrival times. The accuracy of the discrete-time approach is demonstrated by comparing this approach with a discrete-event simulation model in continuous-time. Subsequently, the model is applied to two cases: a transportation case from the health care industry and the process of building a batch for a batch processor.     

Experimental and Semi-Empirical and DFT Calculational Studies on (<Emphasis Type="Italic">E</Emphasis>)-2-[(2,4-Dichlorophenylimino) methyl]-<Emphasis Type="Italic">p</Emphasis>-cresol

Abstract  

The molecular and crystal structure of the title compound, C₁₄H₁₁Cl₂NO, has been determined by X-ray single crystal diffraction technique. The compound crystallizes in the orthorhombic, space group Pbca with unit cell dimensions a = 7.5537(10) ?, b = 11.5518(13) ?, c = 29.760(4) ?, M _r  = 280.14, V = 2596.8(6) ?³, Z = 8, R ₁ = 0.065 and wR ₂ = 0.191. The title compound exists in the enol–imine tautomeric form with a strong intramolecular O–H···N hydrogen bond. The dihedral angle between the two benzene rings is 37.66(15)°. The asymmetric unit in the crystal structure contains only one neutral molecule. Calculational studies were performed by using AM1, PM3, PM6 semi-empirical and DFT methods. Geometry optimizations of compound have been carried out by using three semi-empirical methods and DFT method and bond lengths, bond and torsion angles of title compound have been determined. Dipole moments (Debye) and the energy parameters of compound (kcal/mol) were calculated by using above mentioned calculation methods. Atomic charge distribution has been obtained from AM1, PM3, PM6 and DFT. In order to determine conformational flexibility on the molecule, molecular energy profile of the title compound was obtained with respect to the selected torsion angle T(N1–C7–C1–C2), which is varied from −180° to +180° in every 10 via PM3 semi-empirical method.     

Determination of polycyclic aromatic hydrocarbons in waters by ultrasound-assisted emulsification-microextraction and gas chromatography-mass spectrometry

An ultrasound-assisted emulsification-microextraction (USAEME) procedure was developed for the extraction of US EPA 16 polycyclic aromatic hydrocarbons (PAHs) in 10 mL of water samples, with subsequent determination by gas chromatography-mass spectrometry (GC-MS). After determination of the most suitable solvent and solvent volume, several other parameters (i.e., extraction time, centrifugation time and ionic strength of the sample) were optimized using a 2³ factorial experimental design. Limits of detection ranged from 0.001 to 0.036 μg L⁻¹. The developed procedure was applied to fortified distilled water with different fortification levels (0.5, 2 and 5 μg L⁻¹). Recoveries were over 92% and relative standard deviations of the recoveries were below 8%. The efficiency of the USAEME was compared with traditional liquid-liquid extraction (LLE) and solid-phase extraction on real water samples (i.e., tap water, well water and surface (lake) water as well as domestic and industrial wastewaters). The USAEME showed comparable efficiencies especially with LLE. The developed USAEME was demonstrated to be robust, viable, simple, rapid and easy to use for the determination of PAHs in water samples by GC-MS.     

Commutativity and Ideals in Pre-crystalline Graded Rings

Pre-crystalline graded rings constitute a class of rings which share many properties with classical crossed products. Given a pre-crystalline graded ring A\mathcal{A} , we describe its center, the commutant C_A(A₀)C_{\mathcal{A}}(\mathcal{A}_{0}) of the degree zero grading part, and investigate the connection between maximal commutativity of A₀\mathcal{A}_{0} in A\mathcal{A} and the way in which two-sided ideals intersect A₀\mathcal{A}_{0} .     

Determination of selected polychlorinated biphenyls in soil by miniaturised ultrasonic solvent extraction and gas chromatography-mass-selective detection

Miniaturised ultrasonic solvent extraction procedure was developed for the determination of selected polychlorinated biphenyls (PCBs) in soil samples by gas chromatography-mass-selective detection by using 2³ factorial experimental design. Recoveries of PCBs from fortified soil samples are over 90% for three different fortification levels between 40 and 120 μg kg⁻¹, and relative standard deviations of the recoveries are below 7%. The limits of detection (LODs) ranged from 0.003 to 0.006 μg kg⁻¹. The performance of the proposed method was compared to traditional shake flask extraction method on the spiked real soil sample and extraction methods showed comparable efficiencies. Proposed miniaturised ultrasonic solvent extraction offers several advantages, i.e., reducing sample requirement for measurement of target compound, less solvent consumption and reducing the costs associated with solvent purchase and waste disposal.     

Preparation of (99m)Tc labeled vitamin C (ascorbic acid) and biodistribution in rats

The aim of this study was to label ascorbic acid with (99m)Tc and to investigate its radiopharmaceutical potential in rats. Ascorbic acid was labeled with (99m)Tc using the stannous chloride method. The radiochemical purity of [(99m)Tc]ascorbic acid ((99m)Tc-AA) was determined by RTLC, paper electrophoresis, and RHPLC methods. The labeling yield was found to be 93+/-5.0%. The maximum labeling yield of (99m)Tc-AA was determined at pH 5 and 25 degrees C. The biodistribution studies related to (99m)Tc-AA were done in male albino Wistar rats. (99m)Tc-AA, which has a specific activity of 13.02 GBq/mmol, was administered into the tail vein of the rats. The rats were sacrificed at 15, 30, 60, and 120 min after the injection by heart puncture under ether anaesthesia. The organs were weighed after removal. Their activities were counted using a Cd(Te) detector equipped with a RAD 501 count system. The %ID/g (% of injected dose per gram of tissue weight) in each organ and in blood was calculated. Maximum uptake of (99m)Tc-AA was observed in prostate and kidneys at the 60th min. (99m)Tc-AA may be a promising radiopharmaceutical for the imaging of prostate and kidneys.     

Optimization of the Determinant of the Vandermonde Matrix and Related Matrices

The value of the Vandermonde determinant is optimized over various surfaces, including the sphere, ellipsoid and torus. Lagrange multipliers are used to find a system of polynomial equations which give the local extreme points in its solutions. Using Gröbner basis and other techniques the extreme points are given either explicitly or as roots of polynomials in one variable. The behavior of the Vandermonde determinant is also presented visually in some interesting cases.     

Endogenous reference points in bargaining

We allow the reference point in (cooperative) bargaining problems with a reference point to be endogenously determined. Two loss averse agents simultaneously and strategically choose their reference points, taking into consideration that with a certain probability they will not be able to reach an agreement and will receive their disagreement point outcomes, whereas with the remaining probability an arbitrator will distribute the resource by using (an extended) Gupta–Livne bargaining solution (Gupta and Livne in Manag Sci 34:1303–1314, 1988). The model delivers intuitive equilibrium comparative statics on the breakdown probability, the loss aversion coefficients, and the disagreement point outcomes.