A novel automatic suspicious mass regions identification using Havrda & Charvat entropy and Otsu's N thresholding

Mass detection is a very important process for breast cancer diagnosis and computer aided systems. It can be very complex when the mass is small or invisible because of dense breast tissue. Therefore, the extraction of suspicious mass region can be very challenging. This paper proposes a novel segmentation algorithm to identify mass candidate regions in mammograms. The proposed system includes three parts: breast region and pectoral muscle segmentation, image enhancement and suspicious mass regions identification. The first two parts have been examined in previous studies. In this study, we focused on suspicious mass regions identification using a combination of Havrda & Charvat entropy method and Otsu's N thresholding method. An open access Mammographic Image Analysis Society (MIAS) database, which contains 59 masses, was used for the study. The proposed system obtained a 93% sensitivity rate for suspicious mass regions identification in 56 abnormal and 40 normal images.     

THE EFFECT ON THE THERMAL EFFICIENCY OF LIME ADDED TO THE COMBUSTION CHAMBER FOR RETENTION ON SULPHUR

ABSTRACT

In order to prevent the emission of SO_x, with the flue gas, certain amount of the sulphur of the coal can be retained by adding an adequate amount of lime in the combustion chamber. In this study, two series of experiments were conducted by adding lime at the molar ratios of CaO/S = 0·5 to 2·0 using Ankara-Beypazan lignites, which have around 5 % sulphur content as received form. In one of the series lime was added directly in to the lump coal, and in the other, coal was briquetted together with lime using molasses as binder. It was observed from the experimental results that the increase in the lime ratio leads to an increase in the retained sulphur percentage while it leads to a considerable decrease in thermal efficiency. In order to retain 50 % of sulphur, it was necessary to add lime into lump coal at a CaO/S molar ratio of at least 1,1. This minimum ratio was 0·70 for briquetted coal. When lime was added at these ratios, the thermal efficiencies in the first case dropped to as low as 82 % and to 92 % in the second.     

Slip in flows of power-law liquids past smooth spherical particles

The effect of slip in flows of power-law liquids past smooth spherical particles is numerically studied by using Navier’s linear slip model. For computational simplicity, a sphere-in-sphere type computational domain has been chosen. Thus, the governing conservation equations of mass and momentum are considered in spherical coordinates. These are solved by using a finite difference method-based simplified marker and cell algorithm implemented on a staggered grid arrangement. The non-Newtonian terms of the momentum equation are discretized by a second-order central differencing scheme, whereas the convective terms are discretized by using QUICK scheme. The reliability and accuracy of the solver is established by comparing the present numerical results with the existing literature counterparts. Furthermore, extensive new results are obtained in the range of conditions for Reynolds number, Re: 0.1–200; power-law behavior index, n: 0.5–1.6; and a dimensionless slip parameter, λ: 0.01–100. Finally, effects of these dimensionless parameters on near surface flow kinematics are thoroughly delineated.     

The TeO2-Na2O System: Thermal Behavior,Structural Properties,and Phase Equilibria

Thermal behavior, structural properties, and phase equilibria of the (100−x)TeO₂-xNa₂O system were studied in the 5 ≤ x ≤ 50 mol% composition range. Investigation of glass formation behavior in the binary system was realized, and the glass formation range was determined as 7.5 ≤ x ≤ 40 mol%. Differential thermal analysis (DTA) and Fourier transform infrared (FTIR) spectroscopy techniques were used for thermal and structural characterization of the glasses. Influence of Na₂O content on glass transition temperature (T_g), glass stability (∆T), density (ρ), molar volume (V_M), oxygen molar volume (V_O), and oxygen packing density (OPD) values of sodium tellurite glasses was evaluated considering the structural transformations in the glass network. For the phase equilibria studies, DTA, X-ray diffraction (XRD), and scanning electron microscopy/energy dispersive X-ray (SEM/EDS) techniques were utilized to characterize the heat-treated samples. According to the phase equilibria studies, three eutectic regions were detected in the 0 < x < 50 mol% composition range of the (100−x)TeO₂-xNa₂O system. A new invariant endothermic reaction was detected for the compositions between 40 ≤ x ≤ 45 mol%. Na₂O.8TeO₂ (11.11 mol% Na₂O) compound that was claimed to exist in the binary system in the literature was found to be the metastable δ-TeO₂ phase.     

Admittance Loci Based Design of Plasmonic Sensor Working in Wavelength Interrogation Regime

A prism coupler based plasmonic sensor consisting of a prism, gold (Au) metal film and dielectric sample has been investigated with the use of admittance loci method in wavelength interrogation mode. Prism materials namely fused silica, chalcogenide (2S2G) and silicon have been used to study their effect on surface plasmon sensing in wavelength interrogation mode by admittance loci plots and by corresponding surface plasmon sensing curves. The performance of the plasmonic sensor under wavelength interrogation mode based on the choice of the prism material has been discussed and validated by the dynamic range and sensitivity plots.     

Mechanochemical and Ceramic Synthesis of Cobalt Ferrite

Glass and Ceramics - The effect of mechanochemical activation on the formation of a cobalt ferrite phase from iron and cobalt oxalates was studied. X-ray phase, x-ray diffraction, and simultaneous...     

预应力框架弯矩调幅设计应注意的几个问题

预应力框架弯矩调幅规律与连续梁相比有着自己的特点,通过对柱梁线刚度比、外荷载形式、次弯矩和柱铰可行性几个方面进行分析,希望可以对预应力框架弯矩调幅设计提供一点参考和帮助。     

Functional and chemical characterization of the aging process of an igniter

The igniter consisting of 34% Mg, 60% KNO₃, 3% KClO₄ and 3% organic binder was subjected to accelerated aging under the conditions of 85% relative humidity at 65°C, 75°C and 85°C, and at 75°C with 92% relative humidity. Chemical aging was followed through formation of Mg(OH)₂ and KNO₂. Functional characterization was accomplished in a device constructed to enable simultaneous determination of the heat of combustion and pressure-time recording of the combustion process of both fresh and aged samples. The maximum acceptable deterioration occured at different times depending upon the conditions. The acceleration factor for every 10°C at 85% relative humidity is on average 2.8, leading to a prediction of shelf life of not more than 4 years at 25°C. At the time when burning characteristics were significantly changed, the mixture suffered only slight chemical changes, with only about 1% Mg(OH)₂ and 0.5% KNO₂ being formed. Thus, no chemical changes should be tolerated in such formulations.