Non-linear ultrasonic technique to assess fatigue damage in structural steel

A non-linear ultrasonic technique has been used to assess the fatigue damage in low carbon structural steel. The percentage of total harmonic distortion, which is the ratio of the amplitude of 2nd harmonic and the fundamental, has been introduced as the measurement parameter in this paper. It has also been observed that before crack initiation the 2nd harmonic amplitude is comparable to the fundamental. The results have been analysed in light of the dislocation theory for harmonic generation during material degradation

Investigation of complete and incomplete fusion in 7^{7}Li+124^{124}Sn reaction around Coulomb barrier energies

The complete and incomplete fusion cross sections for $^{7}$Li+$^{124}$Sn reaction were measured using online and offline characteristic $\gamma$-ray detection techniques. The complete fusion (CF) cross sections at energies above the Coulomb barrier were found to be suppressed by $\sim$ 26 \% compared to the coupled channel calculations. This suppression observed in complete fusion cross sections is found to be commensurate with the measured total incomplete fusion (ICF) cross sections. There is a distinct feature observed in the ICF cross sections, i.e., $\textit{t}$-capture is found to be dominant than $\alpha$-capture at all the measured energies. A simultaneous explanation of complete, incomplete and total fusion (TF) data was also obtained from the calculations based on Continuum Discretized Coupled Channel method with short range imaginary potentials. The cross section ratios of CF/TF and ICF/TF obtained from the data as well as the calculations showed the dominance of ICF at below barrier energies and CF at above barrier energies.Comment: 9 pages, 8 figure

Aplikasi Pembelajaran Tentang Ular Di Indonesia Berbasis Android

Indonesia is the largest archipelago country in the world. Every island in Indonesia has a variety of different biological. Variety of biological diversity in Indonesia is also one of the largest in the world. Various types of flora and fauna which adorn every island in Indonesia into a separate icon for each island. One of the existing biodiversity in Indonesia is the type of snake. Indonesia has approximately 20% of the snakes scattered in every island. Such varieties include size, color, and the level of spreading in Indonesia. For all sorts of information about the snakes that exist today is still fairly quite minimal. Books that discuss the types of snakes are still relatively minimal. As the smartphone now has become part of every society, the book was gradually being abandoned. Therefore, the objective of this research is to create an application that can help provide information about snakes in Indonesia with more ease.In this research, the creation of applications of learning about snakes in Indonesia based on Android, which is one smartphone operating system that is used in many circles. This app has a feature that can help users, especially information about snakes, handling and handle snake bites, as well as a variety of other additional information.Based on the results of the implementation and testing is done, the application can provide information about snakes accompanied by photographs and spreading displayed with a map, a brief description and video handling snake bites and how to handle, question and answer forum for sharing information, as well as the provision of other additional information. With this application users can use the information to increase knowledge

Fresnel zone plates for Achromatic Imaging Survey of X-ray sources

A telescope with Fresnel Zone Plates has been contemplated to be an excellent imaging mask in X-rays and gamma-rays for quite some time. With a proper choice of zone plate material, spacing and an appropriate readout system it is possible to achieve any theoretical angular resolution. We provide the results of numerical simulations of how a large number of X-ray sources could be imaged at a high resolution. We believe that such an imager would be an excellent tool for a future survey mission for X-ray and gamma-ray sources which we propose.Comment: 4 Pages, 5 Figures, Proceeding of the 2nd Kolkata Conference on "Observational Evidence for the Black Holes in the Universe", Published in AIP, 200

Development of Online Defect Detection System for High End Wires

Wire rods are drawn into various diameters in multi pass wire drawing machines. These drawn wires should be free from surface defects. Sometimes surface defects are observed in finished wires which can be caused due to poor wire rod surface quality or can be generated during wire drawing process. At present quality assurance is based on visual inspection. Surface quality of entire length of drawn wire cannot be ensured by the existing system causing defective wires delivered to customers. There is a need to develop and implement a low cost online defect detection system to ensure that the finished wires are free from surface defects. In this work, a new system for online inspection of thin wires has been developed. The system will be capable of detecting various types of defects like sliver, transverse crack, fin and lap discontinuities that commonly arise in the process of wire drawing based on the signature of the received signal. This paper will demonstrate the need and way forward to develop a low cost defect identification system for thin wires

Antimagnetic rotation and sudden change of electric quadrupole transition strength in 143Eu

Lifetimes of the states in the quadrupole structure in 143Eu have been measured using the Doppler shift attenuation method as well as parity of the states in the sequence has been firmly identified from polarization measurement using the Indian National Gamma Array. The decreasing trends of the deduced quadrupole transition strength B(E2) with spin, along with increasing J (2) /B(E2) values before band crossing, conclusively establish the origin of these states as arising out of antimagnetic rotation. The abrupt increase in the B(E2) values after the band crossing in the quadrupole band, a novel feature observed in the present experiment, may indicates the crossing of different shears configurations resulting in re-opening of shears structure. The results are well reproduced by numerical calculation within the framework of semi-classical geometric model.Comment: 6 pages, 4 postscript figure

Small Quadrupole Deformation for the Dipole Bands in 112In

High spin states in $^{112}$In were investigated using $^{100}$Mo($^{16}$O, p3n) reaction at 80 MeV. The excited level have been observed up to 5.6 MeV excitation energy and spin $\sim$ 20$\hbar$ with the level scheme showing three dipole bands. The polarization and lifetime measurements were carried out for the dipole bands. Tilted axis cranking model calculations were performed for different quasi-particle configurations of this doubly odd nucleus. Comparison of the calculations of the model with the B(M1) transition strengths of the positive and negative parity bands firmly established their configurations.Comment: 10 pages, 11 figures, 2 table