Synthesis of AA7075 Based 10 wt.% Graphite Reinforced Composites for High Damping Capacity

2021 ◽  
Vol 40 ◽  
pp. 13-24
Author(s):  
N.B. Dhokey ◽  
Anil G. Jadhav ◽  
Shubham S. Nimbalkar ◽  
Vijay Nimbalkar
Keyword(s):  
Induction Furnace ◽  
Research Work ◽  
Damping Capacity ◽  
Reinforced Composites ◽  
Steel Mold ◽  
Capacity Improvement ◽  
Improved Performance ◽  
Particulate Volume ◽  
Processing Cycle ◽  
Made In

The damping capacity improvement in under seawater for torpedo cone is the main of the research work. In the proposed work, an induction furnace was used to fabricate aluminum alloy AA7075 by melting individual elements such as pure Al, Zn, Mg, and Cu, followed by 10 wt.% graphite with varying sizes of reinforcement C1 (3 to 10μm), C2 (53 to 66μm), and C3 (106 to 150μm). Ingot casting was made in steel mold of 45 45 120mm3 and then hot forged at 490ᵒC, followed by solutionizing and artificial aging. Composites characterized for optical, SEM, hardness, and DMA analysis for loss factor. The improved performance in damping capacity by 50% observed for the threshold modulus of particulate (volume to the surface) for C2 composite. The processing cycle of fabrication of composites has been established.

scholarly journals Optimal Randomness for Stochastic Configuration Network (SCN) with Heavy-Tailed Distributions

Entropy ◽  
2020 ◽  
Vol 23 (1) ◽  
pp. 56
Author(s):  
Haoyu Niu ◽  
Jiamin Wei ◽  
YangQuan Chen
Keyword(s):  
Research Work ◽  
Cauchy Distribution ◽  
Classification Model ◽  
Test Accuracy ◽  
Functional Link ◽  
Heavy Tailed Distributions ◽  
Heavy Tailed ◽  
Improved Performance ◽  
Hidden Layer ◽  
Hidden Nodes

Stochastic Configuration Network (SCN) has a powerful capability for regression and classification analysis. Traditionally, it is quite challenging to correctly determine an appropriate architecture for a neural network so that the trained model can achieve excellent performance for both learning and generalization. Compared with the known randomized learning algorithms for single hidden layer feed-forward neural networks, such as Randomized Radial Basis Function (RBF) Networks and Random Vector Functional-link (RVFL), the SCN randomly assigns the input weights and biases of the hidden nodes in a supervisory mechanism. Since the parameters in the hidden layers are randomly generated in uniform distribution, hypothetically, there is optimal randomness. Heavy-tailed distribution has shown optimal randomness in an unknown environment for finding some targets. Therefore, in this research, the authors used heavy-tailed distributions to randomly initialize weights and biases to see if the new SCN models can achieve better performance than the original SCN. Heavy-tailed distributions, such as Lévy distribution, Cauchy distribution, and Weibull distribution, have been used. Since some mixed distributions show heavy-tailed properties, the mixed Gaussian and Laplace distributions were also studied in this research work. Experimental results showed improved performance for SCN with heavy-tailed distributions. For the regression model, SCN-Lévy, SCN-Mixture, SCN-Cauchy, and SCN-Weibull used less hidden nodes to achieve similar performance with SCN. For the classification model, SCN-Mixture, SCN-Lévy, and SCN-Cauchy have higher test accuracy of 91.5%, 91.7% and 92.4%, respectively. Both are higher than the test accuracy of the original SCN.

scholarly journals EFFECT OF SPANDEX DENIER OF WEFT CORE SPUN YARN ON PROPERTIES OF FINISHED STRETCH WOVEN FABRIC

2020 ◽  
Vol 7 (7) ◽  
pp. 21-32
Author(s):  
Sunny Pannu ◽  
Meenakshi Ahirwar ◽  
Rishi Jamdigni ◽  
B. K. Behera
Keyword(s):  
Research Work ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
The Core ◽  
Spun Yarn ◽  
Spun Yarns ◽  
Recovery Percentage ◽  
Shape Retention ◽  
Dual Core ◽  
Made In

The woven fabrics containing cotton/spandex core spun yarns possesses very vital properties of stretch, recovery and thus shape retention from the view point of wearing comfort and garment appearance. Spandex present in the core of core spun yarn is the most essential performer behind these properties. An attempt is made in this research work to study the influence of changing spandex denier in core spun yarn on the stretch and functional properties of stretch woven fabrics. The sole objective of this study is to find out whether different stretch, shrinkage and physical properties of stretch woven fabrics depend upon changing spandex percentage achieved by means of change in spandex filament denier. It was observed that by increasing denier of spandex in core spun weft yarns the increase in weft shrinkage diminishes. Dual core weft with spandex provides good elongation percentage and recovery percentage. The fabric with higher denier spandex in yarn shows a decreasing total hand values trend for summer and winter. The results depicts that the fabrics have higher THV for winter suiting fabrics as compared to summer suiting thus are more suitable for the winter wear.

scholarly journals ORGANIZATION OF STUDENTS’ RESEARCH WORK IN A FOREIGN LANGUAGE

2019 ◽  
Vol 1 (16) ◽  
pp. 105-111
Author(s):  
H.M Shalatska
Keyword(s):  
Foreign Language ◽  
Research Work ◽  
Gradual Transition ◽  
Student Writing ◽  
Student Research ◽  
Language Class ◽  
Study Results ◽  
Language Classes ◽  
Language Environment ◽  
Made In

The article considers the peculiarities of the organization of students’ research work in a technical university in foreign language classes with a gradual transition from simple forms of research to more complex ones, which is aimed at the harmonious development and improvement future specialists’ skills and abilities. The purpose of this article is to identify the main problems of the organization of students’ research work in a foreign language and consider ways of improving this process. Special attention is paid to the tasks, functions, components and various forms of students' research work. The researcher describes the possibility of using assignments for research work and organizing their performing by students in a foreign language class, in particular, such tasks as writing a summary of the text proposed by the teacher, corresponding to the student’s specialization, drawing up a plan for it, drawing up terminological dictionaries, preparing reports on a given topic, writing creative works, essays, drawing up tables and diagrams, solving problematic issues related to the future profession of a student, writing abstracts,  preparing the presentation of study' results. The involvement students in the work of scientific conferences, seminars, competitions, contests, and meetings with leading foreign experts are encouraged. The defense of master's and diploma projects in a foreign language prepares the student for the exercise of profession and integration into a foreign language environment. The examples of the most common mistakes made in the preparation of research works, which indicate the lack of students’ research skills formation are given, and ways to overcome them are recommended. The conclusions are related and future works are suggested. Thus, it also possible to create an education plans of student’ research work in foreign language and recommendations for the specific academic curriculum.

Transient Radiative Transfer in Anisotropically Scattering Media Using Monotonicity-Preserving Schemes

2000 ◽  
Author(s):  
M. Sakami ◽  
K. Mitra ◽  
P.-F. Hsu
Keyword(s):  
Radiative Transfer ◽  
Research Work ◽  
Discrete Ordinates ◽  
Scattering Media ◽  
Discrete Ordinates Method ◽  
Piecewise Parabolic ◽  
Phase Functions ◽  
Monotonicity Preserving ◽  
Made In ◽  
Thick Medium

Abstract This research work deals with the analysis of transient radiative transfer in one-dimensional scattering medium. The time-dependant discrete ordinates method was used with an upwind monotonic scheme: the piecewise parabolic scheme. This scheme was chosen over a total variation diminishing version of the Lax-Wendroff scheme. These schemes were originally developed to solve Eulerian advection problem in hydrodynamics. The capability of these schemes to handle sharp discontinuity in a propagating electromagnetic wave front was compared. The accuracy and the efficiency of the discrete ordinates method associated with the piecewise parabolic advection scheme were studied. Comparisons with Monte Carlo and integral formulation methods show the accuracy and the efficiency of this proposed method. Parametric study for optically thin and thick medium, different albedos and phase functions is then made in the unsteady state zone.

THE ANALYTICAL PROBLEM OF MAPLE SAP PRODUCTS

1941 ◽  
Vol 19b (3) ◽  
pp. 68-72
Author(s):  
Paul Riou ◽  
Joachim Delorme
Keyword(s):  
Systematic Study ◽  
Research Work ◽  
Analytical Problem ◽  
Methods Of Analysis ◽  
Maple Sap ◽  
Official Methods Of Analysis ◽  
Made In

A systematic study of official methods of analysis of maple sap products has been made in order to investigate their validity as criteria of the purity of these products.A new value, the manganese number, is being proposed as a safer criterion but, in some cases, even this may lead to error.The conclusion of the writers is that, at the present time, it cannot be stated with certainty that a maple product is 100% pure; it is therefore necessary that research work be continued in order to find a criterion of purity that would be valid in every case.

scholarly journals Making 3D-Cry Toxin Mutants: Much More Than a Tool of Understanding Toxins Mechanism of Action

Toxins ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 600
Author(s):  
Susana Vílchez
Keyword(s):  
Mechanism Of Action ◽  
Rational Design ◽  
Historical Context ◽  
Cry Toxins ◽  
Natural Toxins ◽  
Enhanced Activity ◽  
Cry Toxin ◽  
Improved Performance ◽  
Bacterium Bacillus ◽  
Made In

3D-Cry toxins, produced by the entomopathogenic bacterium Bacillus thuringiensis, have been extensively mutated in order to elucidate their elegant and complex mechanism of action necessary to kill susceptible insects. Together with the study of the resistant insects, 3D-Cry toxin mutants represent one of the pillars to understanding how these toxins exert their activity on their host. The principle is simple, if an amino acid is involved and essential in the mechanism of action, when substituted, the activity of the toxin will be diminished. However, some of the constructed 3D-Cry toxin mutants have shown an enhanced activity against their target insects compared to the parental toxins, suggesting that it is possible to produce novel versions of the natural toxins with an improved performance in the laboratory. In this report, all mutants with an enhanced activity obtained by accident in mutagenesis studies, together with all the variants obtained by rational design or by directed mutagenesis, were compiled. A description of the improved mutants was made considering their historical context and the parallel development of the protein engineering techniques that have been used to obtain them. This report demonstrates that artificial 3D-Cry toxins made in laboratories are a real alternative to natural toxins.

Gabbro in Wanning, Hainan Island: LA-ICP-MS Chronometry and its Geological Significance

2011 ◽  
Vol 137 ◽  
pp. 307-311
Author(s):  
Li Mei Tang
Keyword(s):  
Tectonic Setting ◽  
Research Work ◽  
Hainan Island ◽  
Major And Trace Elements ◽  
Ocean Basin ◽  
Age Dating ◽  
Icp Ms ◽  
Tethys Ocean ◽  
T Values ◽  
Made In

Gabbro is mostly the result of partly melting from mantle rock, and its formation is usually related with extension tectonic, the research work on Triassic gabbro from Hainan island has important instruction significance to its tectonic background. System chronometry and geochemistry research on hornblende gabbro in Wanning area was made in this paper, and its tectonic significance is to be discussed. The LA-ICP-MS zircon U-Pb age dating result shows that the gabbro in Wanning area was formed in 241±1.7Ma. The major and trace elements characteristic shows that the rocks belong to alkaline series, enrichment in light REE (LREE/HREE＝7.22-8.5) and LILE Rb, Th, and Sr, Ba while depleted in HFSE Nb, Ta and Zr, Hf. The Wanning gabbro exhibits a narrow range of εNd(t) values (1.59-1.76), and a broad rang 87Sr/86Sr initial ratios(0.70633-0.70964). The tectonic background of Wanning gabbro is intracontinental extensional setting, and its geochemistry characteristic declare that there was an ancient ocean basin existed, and maybe one branch of the ancient eastern Tethys ocean. The formation age and tectonic setting declare that the ancient ocean basin was disappeared at least before 241Ma.

Challenges and Opportunities in Multifunctional Nanocomposite Structures for Aerospace Applications

MRS Bulletin ◽  
2007 ◽  
Vol 32 (4) ◽  
pp. 328-334 ◽  
Author(s):  
Jeff Baur ◽  
Edward Silverman
Keyword(s):  
Composite Structures ◽  
Reinforced Composites ◽  
Aerospace Applications ◽  
Structural Applications ◽  
Challenges And Opportunities ◽  
The Status ◽  
Hierarchical Composites ◽  
Easy Integration ◽  
Nanocomposite Structures ◽  
Made In

AbstractOne important application of nanocomposites is their use in engineered structural composites. Among the wide variety of structural applications, fiber-reinforced composites for aerospace structures have some of the most demanding physical, chemical, electrical, thermal, and mechanical property requirements. Nanocomposites offer tremendous po tential to improve the properties of advanced engineered composites with modest additional weight and easy integration into current proc essing schemes. Sig nificant progress has been made in fulfilling this vision. In particular, nanocomposites have been applied at numerous locations within hierarchical composites to improve specific properties and optimize the multifunctional properties of the overall structure. Within this ar ticle, we review the status of nanocomposite incorporation into aerospace composite structures and the need for continued development.

Delamination in Drilling of Sisal/Banana Reinforced Composites Produced by Hand Lay-Up Process

2017 ◽  
Vol 867 ◽  
pp. 29-33 ◽  
Author(s):  
A. Saravana Kumar ◽  
P. Maivizhi Selvi ◽  
L. Rajeshkumar
Keyword(s):  
Natural Fiber ◽  
Signal To Noise Ratio ◽  
Research Work ◽  
Synthetic Fiber ◽  
Sisal Fiber ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Banana Fiber ◽  
Fiber Reinforced Polymer Composites ◽  
Drill Tool

Natural fiber composites are presently replacing the synthetic fiber in many fields. The present research work study is an attempt to manufacture and test the sisal/banana fiber reinforced polymer composites. Composite have been manufactured using banana and sisal fiber along with epoxy resin as reinforcement. With these composites drilling has been carried out to study the factors and combination of factors that influence the delamination of drilled unidirectional sisal-banana fiber reinforced composites. Drilling experiments were performed based on the L9-Taguchi method. Delamination factor evaluated for the selected parameters spindle speed, feed and diameter of the drill tool with the help of signal to noise ratio, ANOVA analysis and to obtain the conditions for minimum delamination.

Shanshar-Asarshyq arheologııalyq kesheninde júrgіzіlgen barlaý jumystarynyń nátıjelerі [The Results of Research Work in the Archaeological Complex Shanshar-Asarshyk]

2020 ◽  
Vol 3 (117) ◽  
pp. 244-252
Author(s):  
M. Gýrsoı ◽  
◽  
K.M. Jetіbaev ◽  
B. Sızdıkov ◽  
M. Qoja ◽  
...  
Keyword(s):  
Central Asia ◽  
Iron Age ◽  
Research Work ◽  
Animal Husbandry ◽  
Point Of View ◽  
Scientific Concept ◽  
Cattle Breeding ◽  
Architectural Features ◽  
Sedentary Animal ◽  
Made In

The article discusses a new scientific concept made in the course of the excavation and the results of exploration at the archaeological complex of Shanshar-Asarshyk. It provides data on the existence of people during the Paleolithic and iron age and their occupation of sedentary animal husbandry and nomadic cattle breeding. The collected ceramics were analyzed from a macroscopic point of view and described. The found ceramic objects were compared with ceramic objects from other places and the corresponding conclusions were made. In addition, The Shanshar-Asarshyk settlement was compared with other cities in Central Asia and its architectural features and structure were revealed. With the help of the discovered material data, a predictive Dating of the monument was made. The article substantiates the necessity of conducting archeological excavations in the archaeological complex of Shanshar-Asarshyk. Мақалада Шаншар-Асаршық археологиялық кешенінде жүргізілген барлау нәтижелері мен қазба жұмыстары барысында жасалған жаңа ғылыми тұжырымдамалар сөз болады. Бұл жерде адамдардың палеолит және темір дәуірі кезінде өмір сүргені және отырықшы мал шаруашылығы мен көшпенді мал шаруашылығы кәсібімен айналысқандығы туралы деректер айтылады. Жиналған керамикалар макраскопиялық тұрғыдан сарапталып, талдау жүргізіліп, сипаттамасы жасалынды. Табылған керамикалық заттар басқа жердегі керамикалық заттармен салыстырылып, тұжырымдамалар жасалынды. Сонымен қатар Шаншар-Асаршық қалажұрты Орта Азиядағы басқа қалалармен салыстырылып, архитектуралық ерекшелігі мен құрылымы айқындалды. Табылған заттай деректер арқылы ескерткіштің болжамды мерзімдемесі жасалынды. Мақалада Шаншар-Асаршық археологиялық кешенінде археологиялық қазба жұмыстарының жүргізілу қажеттіліктері айтылды.

Sign in / Sign up

Export Citation Format

Share Document