Finite Element Analysis of Steel Quenching Process

The finite element method (FEM) is employed to investigate the residual stress state and the variation of internal stresses in the St5O cylinder bar quenched from 600 to O°C. Thermal analysis is first performed to obtain the cooling curves for the core and surface of the bar, this is followed by a full structural analysis. The results obtained from the computer simulation are compared with those experimentally determined values that are available in the literature and there appears to be a good measure of agreement. The study found that at the initial stages of the quenching process, the residual stresses were tensile at the surface and compressive in the core, however, towards the end of the quenching process, the tensile residual stresses switched to the core and compressive residual stresses at the surface

Aeroelastic model helicopter rotor testing in the Langley TDT

Wind-tunnel testing of a properly scaled aeroelastic model helicopter rotor is considered a necessary phase in the design development of new or existing rotor systems. For this reason, extensive testing of aeroelastically scaled model rotors is done in the Transonic Dynamics Tunnel (TDT) located at the NASA Langley Research Center. A unique capability of this facility, which enables proper dynamic scaling, is the use of Freon as a test medium. A description of the TDT and a discussion of the benefits of using Freon as a test medium are presented. A description of the model test bed used, the Aeroelastic Rotor Experimental System (ARES), is also provided and examples of recent rotor tests are cited to illustrate the advantages and capabilities of aeroelastic model rotor testing in the TDT. The importance of proper dynamic scaling in identifying and solving rotorcraft aeroelastic problems, and the importance of aeroelastic testing of model rotor systems in the design of advanced rotor systems are demonstrated

A Hybrid Approach for Counting Templates in Images

© 2020 ACM. In the research, hybrid algorithm for counting repeated objects in the image is proposed. Proposed algorithm consists of two parts. Template matching sub-algorithm is based on normalized cross correlation function which is widely used in image processing application. Template matching can be used to recognize and/or locate specific objects in an image. Neural network sub-algorithm is needed to filter out false positives that may occur during cross correlation function evaluation. In the last section of the paper experimental evaluation is carried out to estimate the performance of the proposed template matching algorithm for images of blood microscopy and chamomile field image. In the first case, the task is to count erythrocytes in the blood sample. In the second case, it is needed to count the flowers in the field. For all 2 datasets we got precise results that coincides with actual number of objects in image. The reason of such performance is that convolutional neural network sub-algorithm improved initial results of template-matching sub-algorithm based on correlation function

SINGULAR PERTURBATIONS AND BOUNDARY LAYER THEORY FOR CONVECTION-DIFFUSION EQUATIONS IN A CIRCLE: THE GENERIC NONCOMPATIBLE CASE

We study the boundary layers and singularities generated by a convection-diffusion equation in a circle with noncompatible data. More precisely, the boundary of the circle has two characteristic points where the boundary conditions and the external data $f$ are not compatible. Very complex singular behaviors are observed, and we analyze them systematically for highly noncompatible data. The problem studied here is a simplified model for problems of major importance in fluid mechanics and thermohydraulics and in physics.open4

Atmospheric response to cold wintertime Tibetan Plateau conditions over eastern Asia in climate models

Central Asian orography (namely the Tibetan and Mongolian plateaux) sets important features of the winter climate over eastern Asia and the Pacific. By deflecting the mid-latitude jet polewards it contributes to the formation of the Siberian high and, on the lee side, to the advection of dry cold continental air over the eastern Asian coast and the Pacific Ocean, where atmospheric instability and cyclogenesis thrive. While the mechanic forcing by the orography is assessed in a number of modelling studies, it is still not clear how near-surface temperature over the two most prominent orographic barriers of the central Asian continent – the Tibetan and Mongolian plateaux – influences the winter climate. The problem is particularly relevant in view of a well-known cold bias in state-of-the-art climate models in proximity to the Tibetan Plateau, likely related to the modelling of land processes and land–atmosphere interaction over complex orography. Here we take advantage of the large spread in near-surface temperature over the central Asian plateaux within the Coupled Model Intercomparison Project Phase 6 (CMIP6) to study how colder-than-average Asian plateau temperatures impact the atmospheric circulation. Based on composites of the CMIP6 models' climatologies showing the coldest Tibetan Plateau conditions, we find that such negative temperature anomalies appear to amplify the atmospheric response to orography, with an intensification of the eastern Asian winter monsoon and of the equatorward flank of the Pacific jet. The results of the CMIP6 composite analysis are supported by experiments run with an intermediate-complexity atmospheric model, forced by a similar pattern of cold surface temperatures over the central Asian plateaux. Within this setting, the relative influence of the Tibetan and the Mongolian Plateau surface conditions is analysed. Based on the results reported in this work we project that advances in the modelling of the land energy budget over the elevated regions of central Asia could improve the simulation of the climate in the Asian–Pacific sector climate, together with the reliability of climate projections and the performance of shorter-term forecasts.</p

LEAN BEHAVIOR IMPACT TOWARDS LEAN MANAGEMENT: A CASE STUDY

Lean behavior is an essential element to create a continuous improvement culture in the service organization. Meanwhile, continuous improvement is defined as the never-ending efforts for improvement involving everyone in organization. The purpose of this study is to evaluate the changes of behavior practices after the introduction of lean tools and to discuss on how lean behavior in developing the continuous improvement culture in an office environment. This study focuses on self-administered questionnaire method to obtain the real time data for the analysis of behavior practices. Ford Questionnaire is used and distributed to the employees of different management levels in Business Development and IT department. The obtained results are analyzed using the Statistical Package for the Social Sciences (SPSS) software. The same questionnaire survey is conducted after the introduction of lean tools. The expected outcomes of this study is to determine the level of lean behavior practices in the office department and to provide a clear understanding on some lean behavior practices that need to be nurtured among the employees in order to produce a healthy work environment