Asymmetric Cuts In The Contour Method For Residual Stress Measurement

The standard contour method is limited to sectioning test components into two symmetric halves. In this study a new approach is developed to deal with asymmetric cuts in the contour method of residual stress measurement. The proposed approach is demonstrated using finite element (FE) simulations and is validated experimentally using a series of asymmetric contour cuts and neutron diffraction measurements

Histological study on ovary of yellowfin tuna (Thunnus albacares) in the Gulf of Oman

In the present research which was done during the period of July 1997 to June 1998, histological studies on maturation stages of 40 yellowfin tuna specimen (Thunnus albacares) were conducted. It was concluded that the ovaries of this fish had the following characteristics; Germination disk were not present. There were no difference among anterior, posterior and middle parts of maturity stage of ovaries. All observed ovaries were asynchronous. The ovaries had five maturity stages which were as follow: a) Immature b) maturing c) Ripening d) Ripe e) Spent Average dimension of oocyte in different stage are as follow: Immature (40µ); Ripening (<60µ) and Ripe (<120µ)

Numerical solution of fractional Fredholm integro-differential equations by spectral method with fractional basis functions

This paper presents an efficient spectral method for solving the fractional Fredholm integro-differential equations. The non-smoothness of the solutions to such problems leads to the performance of spectral methods based on the classical polynomials such as Chebyshev, Legendre, Laguerre, etc, with a low order of convergence. For this reason, the development of classic numerical methods to solve such problems becomes a challenging issue. Since the non-smooth solutions have the same asymptotic behavior with polynomials of fractional powers, therefore, fractional basis functions are the best candidate to overcome the drawbacks of the accuracy of the spectral methods. On the other hand, the fractional integration of the fractional polynomials functions is in the class of fractional polynomials and this is one of the main advantages of using the fractional basis functions. In this paper, an implicit spectral collocation method based on the fractional Chelyshkov basis functions is introduced. The framework of the method is to reduce the problem into a nonlinear system of equations utilizing the spectral collocation method along with the fractional operational integration matrix. The obtained algebraic system is solved using Newton's iterative method. Convergence analysis of the method is studied. The numerical examples show the efficiency of the method on the problems with smooth and non-smooth solutions in comparison with other existing methods

A Matlab/Simulink Model of Self Excited Induction Generator for an Electrical Brake Application

This paper presents a MATLAB/Simulink dynamic model of an induction generator, which makes simulation studies possible for the design of fuzzy logic controllers for the purpose of controlling the retarding torque output of the generator in an electrical brake application, using the fuzzy logic toolbox of MATLAB. Electrical braking has been proposed in the literature as an alternative to the mechanical braking systems with an advantage of providing lower maintenance costs. An induction generator, acting as a brake, converts the kinetic energy of a vehicle to electrical energy, which can be dissipated in a resistor bank or used in a regenerative mode.The Simulink model developed will be used to design and test controllers for an effective control of the output torque of the electrical brake system

New insights into the physics of inertial microfluidics in curved microchannels. I. Relaxing the fixed inflection point assumption.

Inertial microfluidics represents a powerful new tool for accurately positioning cells and microparticles within fluids for a variety of biomedical, clinical, and industrial applications. In spite of enormous advancements in the science and design of these devices, particularly in curved microfluidic channels, contradictory experimental results have confounded researchers and limited progress. Thus, at present, a complete theory which describes the underlying physics is lacking. We propose that this bottleneck is due to one simple mistaken assumption-the locations of inflection points of the Dean velocity profile in curved microchannels are not fixed, but can actually shift with the flow rate. Herein, we propose that the dynamic distance (δ) between the real equilibrium positions and their nearest inflection points can clearly explain several (previously) unexplained phenomena in inertial microfluidic systems. More interestingly, we found that this parameter, δ, is a function of several geometric and operational parameters, all of which are investigated (in detail) here with a series of experiments and simulations of different spiral microchannels. This key piece of understanding is expected to open the door for researchers to develop new and more effective inertial microfluidic designs

Using PEST as a framework for analyzing open mobility dataz

C

SN 2016iet: The Pulsational or Pair Instability Explosion of a Low Metallicity Massive CO Core Embedded in a Dense Hydrogen-Poor Circumstellar Medium

We present optical photometry and spectroscopy of SN 2016iet, an unprecedented Type I supernova (SN) at $z=0.0676$ with no obvious analog in the existing literature. The peculiar light curve has two roughly equal brightness peaks ($\approx -19$ mag) separated by 100 days, and a subsequent slow decline by 5 mag in 650 rest-frame days. The spectra are dominated by emission lines of calcium and oxygen, with a width of only $3400$ km s$^{-1}$, superposed on a strong blue continuum in the first year, and with a large ratio of $L_{\rm [Ca\,II]}/L_{\rm [O\,I]}\approx 4$ at late times. There is no clear evidence for hydrogen or helium associated with the SN at any phase. We model the light curves with several potential energy sources: radioactive decay, central engine, and circumstellar medium (CSM) interaction. Regardless of the model, the inferred progenitor mass near the end of its life (i.e., CO core mass) is $\gtrsim 55$ M$_\odot$ and up to $120$ M$_\odot$, placing the event in the regime of pulsational pair instability supernovae (PPISNe) or pair instability supernovae (PISNe). The models of CSM interaction provide the most consistent explanation for the light curves and spectra, and require a CSM mass of $\approx 35$ M$_\odot$ ejected in the final decade before explosion. We further find that SN 2016iet is located at an unusually large offset ($16.5$ kpc) from its low metallicity dwarf host galaxy ($Z\approx 0.1$ Z$_\odot$, $M\approx 10^{8.5}$ M$_\odot$), supporting the PPISN/PISN interpretation. In the final spectrum, we detect narrow H$\alpha$ emission at the SN location, likely due to a dim underlying galaxy host or an H II region. Despite the overall consistency of the SN and its unusual environment with PPISNe and PISNe, we find that the inferred properties of SN\,2016iet challenge existing models of such events.Comment: 26 Pages, 17 Figures, Submitted to Ap

Strategic planning for wood farming development (Case study: Urmia)

YesWood farming is one of the strategies of agricultural development programs to reform unsustainable exploitation of natural resources. Poplar is one of the known species for wood farming in the country. This species is fast-growing and has numerous Colognes has the ability to adapt to different climatic conditions. Fast growth, good economic returns and traditional agricultural knowledge, favorable habitat to agriculture are advantages of poplar for agricultural development. However, the result of previous studies indicates existing barriers to the development of plantation and its development need strategic planning. What seem essential today are strategies to overcome these obstacles. Accordingly, this present study with a holistic view trying to identify the strengths, weaknesses, opportunities and threats of poplar farming. And the most appropriate strategies for the development of poplar farming in Urmia have offered. This research was a Field study and conducted using questionnaires. In this study, strategies were defined using SWOT analysis and the strategies were prioritized using analysis network process. The results showed the history of poplar farming in this region is the most important benefit to development and the many uses for poplar wood is the next priority. Increasingly replacement of poplar farming with alternative cultures is one of the main weaknesses of poplar farming development in this region. After that long return of profitability in poplar farming is the second priority. The most important opportunities for the development were the development of credit specialists to support of poplar farming and the most important threat was lack of annual financing of farmers. Also the results of strategic prioritization showed, Modern irrigation methods to reduce water consumption and planning to teach correct principles of technical planting, farming and harvesting are considered as the most important strategies