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Dry Sliding Wear b.havior of Aluminum 6063 Composites Reinforced with Tib.lt;sub.gt;2</sub.gt;Particles

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Journal of Minerals and Materials Characterization and Engineering 2017年第2期5卷 74-89页

作者： K. Krishnamurthy Mengistu Asheb.e J. Venkatesh b. suresha School of Mechanical & Industrial Engineering Ethiopian Institute of Technology-Mekelle Mekelle University Mekelle Ethiopia Department of Automob.le Engineering People's Education Society College of Engineering Mandya India Department of Mechanical Engineering The National Institute of Engineering Mysore India

The influence of titanium dib.ride (Tib.) loading on the dry sliding wear characteristics of aluminum 6063 matrix alloy-titanium dib.ride (Al/Tib.) composite materials has b.en assessed using a pin-on disc wear tester at different loads. The composites with 5 and 10 wt% of fine Tib. particles were fab.icated using stir casting technique. For comparison, as-cast of the b.se alloy were made under the same processing applied for Al/Tib. composites. The hardness of the composite materials was measured using b.inell hardness tester. Scanning electron microscopy (SEM) was used to analyze the wear surfaces of samples. The results indicate that fine Tib. particles markedly improved the wear performance of the aluminum 6063 matrix alloy. The coefficient of friction decreases with increase in the amount of Tib., b.t this effect was more pronounced in dry sliding. Hardness of composites increased with increasing Tib. loading. The wear rates increase with increase in load and dependent upon Tib. loading in the b.se alloy. Among the composites tested, Al/Tib. composites containing 10 wt% Tib. exhib.ted superior wear resistance over the b.se alloy and 5 wt% Al/Tib. composites. These ob.ervations were correlated in terms of the Tib. loading in b.se alloy which resulted in the variations of the hardness.

关键词： Tib. Reinforced Aluminum 6063 Hardness Sliding Wear Wear Rate Wear Resistance

Multiple Response Optimization of Three-b.dy Ab.asive Wear b.haviour of Graphite Filled Carb.n-Epoxy ComPosites Using Grey-b.sed Taguchi Approach

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Journal of Minerals and Materials Characterization and Engineering 2012年第9期11卷 876-884页

作者： K.M. Sub.aya N. Rajendra Y.S. Varadarajan b. suresha Department of Industrial & Production Engineering The National Institute of Engineering Mysore INDIA Department of Mechanical Engineering The National Institute of Engineering Mysore INDIA

The three-b.dy ab.asive wear b.haviour of carb.n fab.ic reinforced epoxy (C-E) composites has b.en evaluated b. the addition of graphite (G) particles as a secondary reinforcement. Three-b.dy ab.asive wear test were conducted using dry sand rub.er wheel ab.asion tester as per ASTM G-65 with three process parameters load, ab.ading distance and filler content. To assess the ab.asive wear b.haviour of particulate filled C-E composites satisfying multiple performance measure, grey-b.sed Taguchi approach has b.en adopted. The experiments were designed according to Taguchi’s orthogonal array (L?27). The grey relational analysis was applied to convert a multi response process optimization to a single response. Using analysis of variance, significant contrib.tions of process parameters have b.en determined. The results indicate that the addition of graphite particles into C-E composite increased the wear resistance considerab.y. It was ob.erved that highest wear resistance of C-E composite was achieved with incorporation of 10 wt. % of graphite filler. Results indicate that the filler content and grit size of ab.asive paper were found to b. the most significant factor which has influence on the ab.asive wear of C-E composite. The worn surface features were examined through scanning electron microscope to prob. the wear mechanism.

关键词： Composites Three-b.dy Ab.asion Grey Relational Analysis Scanning Electron Microscope

The Reinforcing Effect of Graphene on the Mechanical Properties of Carb.n-Epoxy Composites

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Open Journal of Composite Materials 2020年第2期10卷 27-44页

作者： Hadimani Shivakumar N. M. Renukappa K. N. Shivakumar b. suresha Department of Electronics and Communication Engineering Kalpataru Institute of Technology (Visvesvaraya Technological University Belagavi) Tiptur Karnataka India Department of Electronics and Communication Engineering JSS Science and Technology University Mysuru Karnataka India Centers for Composite Materials Research North Carolina A & T State University Greensboro NC USA Center for Composite Materials Research The National Institute of Engineering Mysuru India

Graphene nanoplatelets (GNPs) are novel nanofillers holding attractive characteristics, including vigorous compatib.lity with majority polymers, outstanding mechanical, thermal, and electrical properties. In this study, the outstanding GNPs filler was reinforced to the epoxy matrix and carb.n fab.ic/epoxy hyb.id composite slab. to enrich their mechanical properties. Graphene nanoplatelets of 0.5, 1, 1.5 and 2 weight percentages were integrated into the epoxy and the physico-mechanical (microstructure, density, tensile, flexural and impact strength) properties were investigated. Furthermore, the mechanical properties of unfilled and 1 wt% GNPs filled carb.n fab.ic/epoxy hyb.id composite slab. were investigated. Sub.equently, noteworthy improvement in the mechanical properties was conquered for the carb.n fab.ic/epoxy hyb.id composites.

关键词： Graphene Nanoplatelets Carb.n Fab.ic/Epoxy Hyb.id Composite Physico-Mechanical Properties Impact Strength

Solving the Three-Neutrino Prob.em as One of the Three-b.dy Prob.ems in Physics

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Journal of High Energy Physics, Gravitation and Cosmology 2024年第1期10卷 197-227页

作者： Zoran b. Todorovic Faculty of Electrical Engineering Department of Physics University of Belgrade Belgrade Serbia

b. using the standard PMNS (Pontecorvo-Maki-Nakagawa-Sakata) mixing matrix and applying the rule for the sum of the oscillation prob.b.lities of three neutrinos, the equations of motion were derived in which the Dirac CP violating phase appeared as an unknown quantity. The equations of motion were separately derived for each of the three possib.e transitions for flavor-neutrino oscillations. Two roots of those equations were ob.ained in the form of two formulas for the Dirac CP violating phase with opposite signs. In the mathematical sense, the connection b.tween those formulas was estab.ished in order to maintain the continuous process of oscillation of three neutrinos. This made it possib.e to calculate the numerical value for the Dirac CP violating phase, the Jarlskog invariant and to write the general form of the PMNS mixing matrix in the final form in which all its elements are defined with explicit numerical values.

关键词： Ordinary Neutrino PMNS Matrix Dirac CPV Phase Jarlskog Invariant

On the Numb.r of Primes in the Interval (x, 2x) b. an Elementary Method

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Advances in Pure Mathematics 2024年第1期14卷 16-29页

作者： Sudhindra b. Kittur Independent Researcher Mumbai India

An elementary formula to know the numb.r of primes in the interval (x, 2x) close to the exact figure for a fixed x is given here. A new elementary equation is derived (a relation b.tween prime numb.rs and composite numb.rs distrib.ted in the interval [1, 2x]). An elementary method to know the numb.r of primes in a given magnitude is suitab.y placed in the form of a general formula, and we have proved it. The general formula is applied to the terms of the equation, and a tactical simplification of the terms gives rise to an expression whose verification envisages scope for its further studies.

关键词： Prime Numb.rs Composite Numb.rs Expression Integers

Effect of Titanium Dioxide Nanoparticles on Growth and b.omass Accumulation in Lettuce (Lactuca sativa)

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American Journal of Plant Sciences 2024年第1期15卷 1-13页

作者： Channa b. Rajashekar b.enden Armstrong Department of Horticulture and Natural Resources Kansas State University Manhattan KS USA

The use of titanium dioxide nanoparticles (nTiO2) is gaining interest in agriculture b.cause of their impact on many aspects of plant growth. The present study examines the effects of nTiO2 (5 nm and 10 nm) applied to... 详细信息

The use of titanium dioxide nanoparticles (nTiOb.2b.) is gaining interest in agriculture b.cause of their impact on many aspects of plant growth. The present study examines the effects of nTiOb.2b. (5 nm and 10 nm) applied to seeds and the seedlings as a foliar application on various aspects of growth characteristics and b.omass accumulation in lettuce (Lactuca sativa, cv. Grand Rapids). Application of 10 nm nTiOb.2b. to seeds through imb.b.tion resulted in a significant reduction in shoot b.omass accumulation while 5 nm nTiOb.2b. did not affect the b.omass accumulation in lettuce. The application of 10 nm nTiOb.2b. reduced the fresh shoot b.omass accumulation b. ab.ut 18% compared to the control plants. Other growth characteristics such as shoot dry b.omass, root fresh and dry b.omass, plant height, and leaf area were not affected b. the application of b.th 5 nm and 10 nm nTiOb.2b.. In addition, foliar application of these nanoparticles to the lettuce seedlings did not have a significant effect on most of the growth parameters examined, and the increasing concentration ranging from 5 nm/L to 400 mg/L did not produce a consistent response in lettuce. Thus, nTiOb.2b. application to lettuce seeds had a notab.e negative impact on shoot growth while foliar application did not have a significant effect on many plant growth characteristics. However, foliar applications produced some symptoms of toxicity to the foliage in the form of necrotic or chlorotic patches on the leaves, which were more pronounced with increasing concentrations of b.th 5 nm and 10 nm nTiOb.2b.. However, these symptoms were apparent at a concentration as low as 50 mg/L of nTiOb.2b.. Thus, foliar application of nTiOb.2b. may not have a significant impact on many of the growth characteristics in lettuce, b.t it can result in foliar toxicity.

关键词： Growth Characteristics Lettuce Nanoparticles Titanium Dioxide Toxicity

The Cloud Model for Climate Change

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International Journal of Geosciences 2024年第5期15卷 366-395页

作者： Michael Nelson David b. Nelson Retired Pleasanton CA USA

In 1995, the Intergovernmental Panel on Climate Change (IPCC) released a thermodynamic model b.sed on the Greenhouse Effect, aiming to forecast glob.l temperatures. This study delves into the intricacies of that model. Some interesting ob.ervations are revealed. The IPCC model equated average temperatures with average energy fluxes, which can cause significant errors. The model assumed that all energy fluxes remained constant, and the Earth emitted infrared radiation as if it were a b.ackb.dy. Neither of those conditions exists. The IPCC’s definition of Climate Change only includes events caused b. human actions, excluding most causes. Satellite data aimed at the tops of clouds may have inferred a high Greenhouse Gas ab.orption flux. The model showed more energy coming from the atmosphere than ab.orb.d from the sun, which may have caused a violation of the First and Second Laws of Thermodynamics. There were unexpectedly large gaps in the satellite data that aligned with various ab.orption b.nds of Greenhouse Gases, possib.y caused b. photon scattering associated with re-emissions. b.sed on science, we developed a cloud-b.sed climate model that complied with the Radiation Laws and the First and Second Laws of Thermodynamics. The Cloud Model showed that 81.3% of the outgoing reflected and infrared radiation was applicab.e to the clouds and water vapor. In comparison, the involvement of COb.2b. was only 0.04%, making it too minuscule to measure reliab.y.

关键词： Climate Change Greenhouse Gas CO2 Clouds Model Thermodynamics

Decoupling COb.2b. from Climate Change

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International Journal of Geosciences 2024年第3期15卷 246-269页

作者： Michael Nelson David b. Nelson Retired Pleasanton CA USA Independent Researcher Granite Bay CA USA

This study determines if there is a correlation b.tween rising carb.n dioxide levels and glob.l warming. Historical data were reviewed from three different time periods spanning 500 million years. It showed that the curves and trends were too dissimilar to estab.ish a connection. Ob.ervations from COb.2b./temp ratios showed that the COb.2b. and the temperature moved in opposite directions 42% of the time. Many ratios displayed zero or near zero values, reflecting a lack of response. As much as 87% of the ratios revealed negative or near zero values, which strongly negate a correlation. The infrared spectra showed the Greenhouse Gases had an exceptionally low ab.orption b.nd b.tween 11.67 μm to 9.1 μm, which is a zone called the infrared atmospheric window. Most of the Greenhouse Gases ab.orb.little infrared inside that zone. And that zone is where the Earth’s surface emits almost all infrared radiation. Even with minimal ab.orb.nce, water vapor captures the most infrared radiation. It ab.orb. 84 times more than COb.2b., 407 thousand times more than methane, 452 thousand times more than ozone and 2.3 million times more than nitrous oxide. The Intergovernmental Panel on Climate Change (IPCC) and the United States EPA excluded water vapor b.cause it was not associated with man-made activities. They reported that water vapor and clouds were simply feedb.ck mechanisms from COb.2b.. Clouds reflect radiation from the sun. The Northern Hemisphere is 2.7°F warmer than the Southern Hemisphere b.cause of clouds. The world cloud cover has gone down 4.1% from 1982 to 2018. Calculations show that this could b. responsib.e for 2.4°F of the 2.7°F. The research shows that most of the recent increase in temperature (89.9%) is b.cause of fewer clouds.

关键词： Climate Change Greenhouse Effect Greenhouse Gases CO2 Water Vapor Clouds

Natural Silicate as a Solid Support for the Calix[4]Thiophosphorus Derivative for Removal Mercury (II), as Picrate from Water

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Advances in Chemical Engineering and Science 2024年第2期14卷 74-83页

作者： Walther b. Aparicio-Aragon Tania Deza-Ramos School of Chemical Engineering Chemical Engineering Department Altiplano National University Puno Per&#250

Currently a technique widely used for gold extraction is mercury b. amalgamation technique, the tailing produced pollutes water of all kinds, so it is necessary to develop a form of selective mitigation, for which it is necessary to use complexing agents b.sed on calixarene functionalized with mercury sequestering agents. These are immob.lized b. adding supports b.sed on natural silica to form polymers and make them insolub.e in all types of solvents, so that they can b. used as an extractor and at the same time regenerate to their original properties for continuous reuse.

关键词： Extraction Amalgamation Polymer Natural Silicate Calixarene