Optimization of a dual cycle cogeneration system based on a new exergetic performance criterion

An ecological performance analysis for an irreversible dual-cycle cogeneration system has been performed. The objective function is called as the exergetic-performance coefficient (EPC) and defined as the ratio of total exergy output to the loss rate of availability. The general and optimal performances of the irreversible dual-cycle cogeneration system, having a finite-rate of heat transfer, heat leak and internal irreversibilities based on the EPC objective function have been investigated. Comparisons with respect to the optimal total-exergy output are also provided in order to establish the utility of the new exergetic-performance coefficient. The analyzed results of the dual-cycle cogeneration system considered, working at maximum EPC conditions, have a significant advantage in terms of entropy-generation rate and can be used for the selection of optimal design parameters.     

Numerical Analysis of a Tunnel Support Design in Conjunction with Empirical Methods

In this paper, preliminary support design of a tunnel was analyzed by numerical and empirical approaches. The case study for this analysis is a tunnel to be constructed on the Bilecik-Istanbul roadway in Turkey. The rock mass properties of the tunnel route and design support recommendations were obtained by using an empirical approach. The rock mass properties obtained from the empirical method were used as input parameters for the numerical analysis. The empirical and numerical results, in terms of support design, were evaluated. It was seen that the numerical analysis results supported by empirical values were logical and reliable.     

Interpolated LIR Mth-band filter design with allpass subfilters

We propose a new allpass-based structure for the IIR Mth-and 2Mth-band filters. These filters consist of M allpass filters and an interpolation filter (sum of two allpasses). Consequently, the proposed structure is very efficient in implementation. By choosing the allpass phase appropriately, the resulting phase response of the IIR Mth-band filter becomes approximately linear. An example is designed and compared with FIR Mth-band filters     

Prediction of flow fields and temperature distributions due to natural convection in a triangular enclosure using Adaptive-Network-Based Fuzzy Inference System (ANFIS) and Artificial Neural Network (ANN)

Artificial Neural Network (ANN) and Adaptive-Network-Based Fuzzy Inference System (ANFIS) were used to predict the natural convection thermal and flow variables in a triangular enclosure which is heated from below and cooled from sloping wall while vertical wall is maintained adiabatic. Governing equations of natural convection were solved using finite difference technique by writing a FORTRAN code to generate database for ANN and ANFIS in the range of Rayleigh number from Ra = 10⁴ to Ra = 10⁶ and aspect ratio of triangle AR = 0.5 and AR = 1. Thus, the results obtained from numerical solutions were used for training and testing the ANN and ANFIS. A comparison was performed among the soft programming and Computational Fluid Dynamic (CFD) codes. It is observed that although both ANN and ANFIS soft programming codes can be used to predict natural convection flow field in a triangular enclosure, ANFIS method gives more significant value to actual value than ANN.     

Classification of Diabetic Macular Edema and Its Stages Using Color Fundus Image

Diabetic macular edema(DME)is a retinal thickening involving the center of the macula.It is one of the serious eye diseases which affects the central vision and can lead to partial or even complete visual loss.The only cure is timely diagnosis,prevention,and treatment of the disease.This paper presents an automated system for the diagnosis and classification of DME using color fundus image.In the proposed technique,first the optic disc is removed by applying some preprocessing steps.The preprocessed image is then passed through a classifier for segmentation of the image to detect exudates.The classifier uses dynamic thresholding technique by using some input parameters of the image.The stage classification is done on the basis of an early treatment diabetic retinopathy study(ETDRS)given criteria to assess the severity of disease.The proposed technique gives a sensitivity,specificity,and accuracy of 98.27%,96.58%,and 96.54%,respectively on publically available database.     

Comparison of E-test with agar dilution methods in testing susceptibility of N. gonorrhoeae to azithromycin

AIMS: To assess the immunoexpression of cyclin D1 and retinoblastoma in a cohort of oesophageal squamous cell carcinoma cases from South Africa to see whether there is a relation between these two proteins. In addition, protein expression was correlated with clinicopathological features. METHODS: Fifty biopsies and 30 oesophagectomy specimens were immunostained with commercially available antibodies to cyclin D1 and retinoblastoma proteins, following microwave antigen retrieval. RESULTS: Twenty three of the 80 cases (29%) showed cyclin D1 protein expression. However, only five cases had > 50% of the tumour cells displaying immunopositivity. Three of the four cases with lymph node spread were cyclin D1 positive in the primary tumour and the metastasis. Fifty three cases were immunoreactive with the antiretinoblastoma antibody; 29 of these cases showing > 50% of cells with immunolabelling. Of the 23 cyclin D1 positive cases, 18 were also retinoblastoma positive. No correlation was observed between cyclin D1 and retinoblastoma protein expression and age, sex, race, or histological grade. CONCLUSIONS: Cyclin D1 is expressed in a minority of cases of oesophageal squamous carcinomas from South Africa. However, three of four cases with lymph node spread were cyclin D1 positive, thus indicating that cyclin D1 positive tumours may have a greater propensity for spread. In addition, 18 of 23 cyclin D1 positive cases also expressed retinoblastoma protein. These findings suggest a possible relation between cyclin D1 and retinoblastoma proteins in a proportion of cases of oesophageal squamous.     

A thermodynamic interpretation of a model for the equilibrium states of water phases in porous materials

A thermodynamic explanation is given for the empirical coefficients in a model for the equilibrium state of water in a porous material.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 47, No. 2, pp. 221–228, August, 1984.     

Turbulent boundary layers with assigned wall shear

In this paper we consider the problem of computing the external velocity distribution on a two-dimensional body in an incompressible boundary-layer flow for a specified wall shear. This leads to an ‘overdetermined’ boundary-value problem for a partial differential equation containing the edge velocity as an unknown parameter. A numerical procedure for determining the external velocity is given, together with several examples for laminar and turbulent boundary layers.     

Surface stress measurement techniques in metal forming

This paper describes and classifies stress measurement techniques used in metal forming to provide research workers with a critical evaluation of usable methods. Eight techniques are considered; pressure transmitting pins, photoelasticity, ridged metallic sheets, paper sheets, split tools, strain gauged tools, orifices in tools and visioplasticity. In addition to these, some new transducer designs using optics and conical pins are presented. These are particularly useful for pressure measurement in hot forming operations.     

Thermal response of an unsteady laminar boundary layer on a flat plate due to step changes in wall temperature and in wall heat flux

The prediction of the entire time-history of the heat transfer process due either to a step change in plate surface temperature or to heat flux is studied for two-dimensional, incompressible laminar flows. The study utilizes a very efficient numerical method for solving the nonsteady energy equation. Numerical results for several Prandtl numbers are compared with analytical results obtained with the restriction of small and large time values, and the range of applicability of these analytical solutions is established.