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101.
This paper presents a technique to automatically detect third-layer cracks at rivet sites in aircraft structures using the response signals collected by giant magneto-resistive (GMR) sensors. The inspection system uses pulsed waveform as the excitation source of a multi-line coil and captures the transient fields associated with the induced eddy currents via a GMR sensor, which was developed to detect cracking and corrosion in multi-layer aircraft structures. An automatic scan of the region around the rivet generates C-scan image data that can be processed to detect cracks under the rivet head. Using a 2-D image of each rivet head, feature extraction and classification schemes based on principal component analysis and the k-means algorithm have been successfully developed to detect cracks of varying size located in the third layers at a depth of up to 10 mm below the surface. 相似文献
102.
Rice milling operation is a very energy-intensive process. The major qualities of the rice which are taken into consideration
while milling are the degree of milling and head rice yield. A laboratory abrasion polisher, modified by attaching a humidifying
and cooling unit, was used to polish long-grain Pusa Basmati rice in order to optimize the polishing conditions. Polishing experiments were carried out using central composite design
for a factorial with a central point, at different initial grain temperatures (5–25 °C) and milling chamber temperatures (11–25 °C)
at a constant humidity level of 95 ± 2% for different time intervals. Models capable of predicting the quality of milled rice
were developed using response surface methodology and used to determine optimum processing conditions. Responses such as degree
of milling (DOM), broken content, and specific energy consumption were used to assess product quality. Optimum milling conditions
of a minimum of 10% DOM, a broken content of 8%, and a specific energy consumption of 11 kJ/DOM were obtained at a milling
chamber temperature of 11 °C, an initial grain temperature of 15 °C, and a milling period of 180 s. 相似文献
103.
104.
Saikat Mukherjee Srinath Srinivasa Satish Chandra D 《Electronic Notes in Theoretical Computer Science》2008,203(3):53
Multi-stream interactive systems can be seen as “hidden adversary” systems (HAS), where the observable behaviour on any interaction channel is affected by interactions happening on other channels. One way of modelling HAS is in the form of a multi-process I/O automata, where each interacting process appears as a token in a shared state space. Constraints in the state space specify how the dynamics of one process affects other processes. We define the “liveness criterion” of each process as the end objective to be achieved by the process. The problem now for each process is to achieve this objective in the face of unforeseen interferences from other processes. In an earlier paper, it was proposed that this uncertainty can be mitigated by collaboration among the disparate processes. Two types of collaboration philosophies were also suggested: altruistic collaboration and pragmatic collaboration. This paper addresses the HAS validation problem where processes collaborate altruistically. 相似文献
105.
Anoop K. Mukhopadhyay Keshaw D. Joshi Arjun Dey Riya Chakraborty Amit Rav Sampad K. Biswas Satish C. Gupta 《Journal of Materials Science》2010,45(13):3635-3651
Symmetric shock experiments were conducted on a 10 μm grain size coarse alumina ceramic with a gas gun to identify its Hugoniot
elastic limit (HEL). To understand the damage initiation and their subsequent growth mechanisms in coarse grain alumina subjected
to shock impact at levels much above the HEL, additional asymmetric shock recovery experiments with the same gas gun were
then deliberately conducted on the same alumina at shock pressure levels more than three times as high as the HEL and the
fragments collected by a dedicated catcher system. Detailed characterization of the shock recovered alumina fragments by X-ray
diffraction, nanoindentation, scanning electron microscopy, field emission scanning electron microscopy and transmission electron
microscopy were utilized to understand the nature and process of failure initiation, incubational growth, coalescence and
propagation leading to fragmentation. Based on these data a new qualitative damage model was developed to explain the deformation
mechanism. 相似文献
106.
Kovacs Maria; Iyengar Satish; Goldston David; Obrosky D. Scott; Stewart James; Marsh Judith 《Canadian Metallurgical Quarterly》1990,58(2):189
Mothers of children with newly diagnosed insulin-dependent diabetes mellitus (IDDM) were assessed repeatedly over a period of 6 years in order to determine the psychological correlates of managing this chronic illness. Both maternal depression and overall emotional distress after the 1st year of the IDDM increased slightly with illness duration and were also influenced by other factors. Mothers' adjustment shortly after their children were diagnosed with IDDM was a strong predictor of their long-term emotional symptomatology. However, mothers' symptoms over time were not related to medical aspects of IDDM (i.e., the extent of the children's metabolic control, number of rehospitalizations, or their compliance with the medical regimen) and were also unrelated to the levels of depression or anxiety reported by their children. Mothers generally found it easier to cope with the IDDM the longer their children had the illness. However, the degree to which mothers perceived the IDDM to be bothersome or difficult to manage at any given point in time was associated with their overall levels of emotional distress. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
107.
Fretting is essentially a surface phenomenon, but bulk stresses and material properties contribute to subsequent failure.
This feature of fretting demands a thorough understanding of near surface stresses under the joint action of normal, shear and thermal loading. Axisymmetric fretting is of great concern in piping
and coupling design. In this paper, we develop design tools for Near Surface Analysis (NSA) for understanding axisymmetric
fretting. Axisymmetric Fretting Analysis (AFA) becomes formidable owing to localised tractions that call for Fourier transform
techniques. We develop two different NSA strategies based on two-dimensional plane strain models: 2D strip model (2DS) and
half-plane Flamant model (2DF). We compare the results of 2DS and 2DF with the exact results for AFA obtained using Love’s
stress function in conjunction with Fourier transform. There is a good correspondence between stress components obtained from
2D-models. 相似文献
108.
Shanju Zhang Lingbo Zhu Marilyn L. Minus Han Gi Chae Sudhakar Jagannathan Ching-Ping Wong Janusz Kowalik Luke B. Roberson Satish Kumar 《Journal of Materials Science》2008,43(13):4356-4362
We report continuous carbon nanotube (CNT) fibers and yarns dry-drawn directly from water-assisted chemical vapor deposition
(CVD) grown forests with about 1-mm height. As-drawn CNT fibers exist as aerogel and can be transformed into more compact
fibers through twisting or densification with a volatile organic liquid. CNT fibers are characterized by scanning electron
microscopy, X-ray photoelectron spectroscopy, Raman microscopy, and wide-angle X-ray diffraction. Mechanical properties and
electrical conductivity of the post-treated CNT fibers are investigated. The resulting fibers show the work of rupture of
30 J/g and DC electrical conductivity of 5.0 × 104 S/m. 相似文献
109.
110.
The simultaneous addition of styrene maleic anhydride copolymer and multiwall carbon nanotubes during melt‐mixing on the morphology of binary blends of polyamide6 and acrylonitrile butadiene styrene copolymer 下载免费PDF全文
B.F. Jogi Arup R. Bhattacharyya Amrita V. Poyekar Petra Pötschke George P. Simon Satish Kumar 《Polymer Engineering and Science》2015,55(2):457-465
The effect of simultaneous addition of multiwall carbon nanotubes (MWNTs) and a reactive compatibilizer (styrene maleic anhydride copolymer, SMA) during melt‐mixing on the phase morphology of 80/20 (wt/wt) PA6/ABS blend has been investigated. Morphological analysis through scanning and transmission electron microscopic analysis revealed finer morphology of the blends in presence of SMA + MWNTs. Fourier transform infrared spectroscopic analysis indicated the formation of imide bonds during melt‐mixing. Non‐isothermal crystallization studies exhibited the presence of a majority faction of MWNTs in the PA6 phase of 80/20 (wt/wt) PA6/ABS blend in presence of SMA + MWNTs. Rheological analysis, dynamic mechanical thermal analysis, and thermogravimetric analysis have demonstrated the compatibilization action of simultaneous addition of a reactive compatibilizer (SMA copolymer) and MWNTs in PA6/ABS blends. An attempt has been made to investigate the role of simultaneous addition of SMA copolymer and MWNTs on the morphology of 80/20 (wt/wt) PA6/ABS blend through various characterization techniques. POLYM. ENG. SCI., 55:457–465, 2015. © 2014 Society of Plastics Engineers 相似文献