Appraisal of Bearing Capacity and Modulus of Subgrade Reaction of Refilled Soils

Soil is remoulded, replaced, or improved in place to meet the required engineering properties. Relative compaction is the measure of the resulting engineering improvement. But design engineers need the allowable bearing capacity while the modulus of subgrade reaction is the primary input of modern foundation design software. The current research appraised a correlation between Relative Compaction ( ), Moisture Content ( ), and allowable bearing capacity ( ) and another correlation between , RC, MC, and modulus of subgrade reaction ( ). The test samples were extracted from each trial of the standard proctor test using purpose-built extraction tubes. Allowable bearing capacity has been determined by performing unconfined compression tests on the extracted tubes. The relationships have been established employing statistical analysis. It was noticed that soil samples at the lower moisture content (6-9%) show brittle failure before reaching the allowable strain. The soil samples having a moisture content of 10-14% exhibited shear failure, nearly simultaneous to the allowable strain. The soil samples having higher moisture content undergone a strain of 15% without showing the shear failure. A simple equation has also been appraised to determined Ks involving the three-input variable, i.e., , , and . Moderate correlations have been found to exist between the studied parameters, owing to some other variables' influence. Recommendations for future studies have been drawn to quantify the effect of identified parameters. Doi: 10.28991/cej-2020-03091606 Full Text: PD

Studies in the Chemistry of Dyes and Their Adsorption by Fibres

The work described had the main purpose of gaining a better understanding of the mechanism by which dyes are sorbed by various substrates. A subsidiary aim was the development of new analytical procedures to simplify the determination of purity of the dyes used and for the detection of hydrogen bonding. Broadly, the work is classified into three main sections, dealing respectively with analysis of dyes, methods of detecting hydrogen bonds, and the study of the sorption of certain natural colouring matters by various fibres and of synthetic dyes by alumina (in the form of anodised aluminium) and cellulose. An oxidative method for the analysis of azo dyes and some dyes of other classes is described. The results for the majority of dyes examined, agree closely with those obtained by titanous chloride analysis, and the new method has the advantage of being simple, rapid and clean in use. The procedure involves measurement of the volume of nitrogen produced on boiling the dye with a dilute solution of potassium dichromate and sulphuric acid. A still simpler, colorimetric method of determining water-soluble azo dyes uses ceric sulphate oxidation. It is useful for some dyes, but many do not react in simple proportion with the oxidant. The use of the refractometer for detecting the complex ratios of hydrogen bond interaction in binary solutions of organic compounds is also described. This method appears equally useful for detecting strongly or weakly-bonded complexes. The reality of the existence of many compounds so detected has been demonstrated by a variety of procedures, including molecular weight determination, preparation of solid complexes, and comparison with complexes previously reported, either by preparation in substance or detection by infra-red spectrophotometry. The dielectric constant and refractive index methods of detecting complex-ratios in hydrogen-bond interactions have been applied to nearly two hundred and seventy pairs of compounds in a variety of solvents. Intra- as well as inter-molecular bonds can be detected, and a qualitative estimate of their relative stability may be made. Alcoholic and phenolic hydroxy-, aldehyde, amido-, amino-, azo-, carboxylic and sulphonic acid, ester, keto-, nitro- and quinone groups are amongst those examined. Several compounds have been included to represent models of certain natural and synthetic polymers. A number of inter- and intra-molecular bonds have been detected involving a hydrogen atom attached to carbon and activated by a neighbouring carbonyl oxygen atom. These include intermolecular bonds between certain esters, e. g. , acetates, and azobenzene and quinone. Supporting evidence is quoted showing that this type of bond may be responsible for the sorption of dyes by cellulose acetate. Numerous examples of shielding of groups by the solvent have been noted, e.g., water protects alcoholic groups against combination with a number of other solutes of low affinity, but not against phenol. The carbonyl oxygen atom in ketones, amides, or aldehydes is for the same reason unable to form intermolecular complexes in benzene, ether or water, but it is reactive in carbon tetrachloride or dioxan. This was checked by examining the sorption of benzene-azo-alpha-naphthylamine and benzene-azo-beta-naphthylamine on anodised aluminium. These compounds show little affinity for anodised aluminium, using benzene as a solvent, but on employing carbon tetrachloride or dioxan, sorption proceeds readily. Bonding between water, used as a solute in anhydrous solvents, and several other compounds has been observed. With the amide or azo groups water acts as a cross-linking agent, each of its hydrogen atoms being attached to a separate molecule of the other solute. The reactions of the alkylamide group have been studied in view of their importance in the interpretation of the behaviour of proteins and nylon. This group appears to react, bifunctionally, in the enol form in organic solvents, but water stabilises the keto-form and it is then usually monofunctional, the carbonyl oxygen being protected by the solvent. A hydrogen atom on the carbon adjacent to the carbonyl group in the keto-form is shown also to be reactive and the bearing of this fact on the interpretation of the action of quinones in tanning proteins is discussed. The bonding properties of carbohydrates and their relation to sorption by cellulose, are also considered. The individual hydroxy- or ether groups in mono- and disaccharides in their normal ring structures, can form intermolecular bonds with other solutes in an anhydrous solvent (ethylene glycol), but not in water, even with phenol, on account of shielding by the solvent. The nitrogen atom in some solutes can combine, in water, with the free aldehyde group in the open-chain form of glucose or cellobiose. It is shown that these facts are consistent with the sorption of dyes by cellulose from water being due to van der Waals attraction rather than by hydrogen bonds, as formerly supposed. (Abstract shortened by ProQuest.)

Quasi-3D Hyperbolic Shear Deformation Theory for the Free Vibration Study of Honeycomb Microplates with Graphene Nanoplatelets-Reinforced Epoxy Skins

A novel quasi-3D hyperbolic shear deformation theory (QHSDT) with five unknowns is here employed, together with the Hamilton's principle and the modified couple stress theory (MCST) to analyze the vibrational behavior of rectangular micro-scale sandwich plates resting on a visco-Pasternak foundation. The sandwich structure features a Nomex or Glass phenolic honeycomb core, and two composite face sheets reinforced with graphene nanoplatelets (GPLs). The effective properties of both face sheets are evaluated by means of the Halpin-Tsai and extended rule of mixture (ERM) micromechanical schemes. The governing equations of the problem are derived by applying the Hamilton's principle, whose solutions are determined theoretically according to a classical Navier-type procedure. A parametric study checks for the effect of different material properties, length-scale parameters, foundation parameters and geometrical properties of the honeycomb cells, and the reinforcing GPLs, on the vibration response of the layered structure, which can be of great interest for many modern engineering applications and their optimization design

Nitrogen-Efficient and Nitrogen-Inefficient Indian Mustard Showed Differential Expression Pattern of Proteins in Response to Elevated CO2 and Low Nitrogen

Carbon (C) and nitrogen (N) are two essential elements that influence plant growth and development. The C and N metabolic pathways influence each other to affect gene expression, but little is known about which genes are regulated by interaction between C and N or the mechanisms by which the pathways interact. In the present investigation, proteome analysis of N-efficient and N-inefficient Indian mustard, grown under varied combinations of low-N, sufficient-N, ambient [CO2] and elevated [CO2] was carried out to identify proteins and the encoding genes of the interactions between C and N. Two-dimensional gel electrophoresis (2-DE) revealed 158 candidate protein spots. Among these, 72 spots were identified by matrix-assisted laser desorption ionization-time of flight/time of flight mass spectrometry (MALDI-TOF/TOF). The identified proteins are related to various molecular processes including photosynthesis, energy metabolism, protein synthesis, transport and degradation, signal transduction, nitrogen metabolism and defense to oxidative, water and heat stresses. Identification of proteins like PII-like protein, cyclophilin, elongation factor-TU, oxygen-evolving enhancer protein and rubisco activase offers a peculiar overview of changes elicited by elevated [CO2], providing clues about how N-efficient cultivar of Indian mustard adapt to low N supply under elevated [CO2] conditions. This study provides new insights and novel information for a better understanding of adaptive responses to elevated [CO2] under N deficiency in Indian mustard

Effect of Au Precursor and Support on the Catalytic Activity of the Nano-Au-Catalysts for Propane Complete Oxidation

Catalytic activity of nano-Au-catalyst(s) for the complete propane oxidation was investigated. The results showed that the nature of both Au precursor and support strongly influences catalytic activity of the Au-catalyst(s) for the propane oxidation. Oxidation state, size, and dispersion of Au nanoparticles in the Au-catalysts, surface area, crystallinity, phase structure, and redox property of the support are the key aspects for the complete propane oxidation. Among the studied Au-catalysts, the AuHAuCl4-Ce catalyst is found to be the most active catalyst

Mechanics of the tricuspid valve: from clinical diagnosis/treatment, in vivo and in vitro investigations, to patient-specific biomechanical modeling

Proper tricuspid valve (TV) function is essential to unidirectional blood flow through the right side of the heart. Alterations to the tricuspid valvular components, such as the TV annulus, may lead to functional tricuspid regurgitation (FTR), where the valve is unable to prevent undesired backflow of blood from the right ventricle into the right atrium during systole. Various treatment options are currently available for FTR; however, research for the tricuspid heart valve, functional tricuspid regurgitation, and the relevant treatment methodologies are limited due to the pervasive expectation among cardiac surgeons and cardiologists that FTR will naturally regress after repair of left-sided heart valve lesions. Recent studies have focused on (i) understanding the function of the TV and the initiation or progression of FTR using both in-vivo and in-vitro methods, (ii) quantifying the biomechanical properties of the tricuspid valve apparatus as well as its surrounding heart tissue, and (iii) performing computational modeling of the TV to provide new insight into its biomechanical and physiological function. This review paper focuses on these advances and summarizes recent research relevant to the TV within the scope of FTR. Moreover, this review also provides future perspectives and extensions critical to enhancing the current understanding of the functioning and remodeling tricuspid valve in both the healthy and pathophysiological states

Load-dependent collagen fiber architecture data of representative bovine tendon and mitral valve anterior leaflet tissues as quantified by an integrated opto-mechanical system

The data presented in this article provide load-dependent collagen fiber architecture (CFA) of one representative bovine tendon tissue sample and two representative porcine mitral valve anterior leaflet tissues, and they are stored in a MATLAB MAT-file format. Each dataset contains: (i) the number of pixel points, (ii) the array of pixel's x- and y-coordinates, (iii) the three acquired pixel intensity arrays, and (iv) the Delaunay triangulation for visualization purpose. This dataset is associated with a companion journal article, which can be consulted for further information about the methodology, results, and discussion of the opto-mechanical characterization of the tissue's CFA's (Jett et al. [1]).Supports from the American Heart Association Scientist Development Grant (SDG) Award (16SDG27760143), the Presbyterian Health Foundation Team Science Grants (C5122401), and the Oklahoma Center for the Advancement of Science and Technology (OCAST) Health Research program (HR-18-002) are gratefully acknowledged. CHL was in part supported by the institutional start-up funds from the School of Aerospace and Mechanical Engineering (AME) and the institutional research funding through the Faculty Investment Program from the Research Council and IBEST-OUHSC Interdisciplinary Funding at the University of Oklahoma. Open Access fees paid for in whole or in part by the University of Oklahoma Libraries.Ye

Regional Geotechnical Mapping Employing Kriging on Electronic Geodatabase

A regional geotechnical map was developed by employing kriging using spatial and s geostatistical analysis tools. Many studies have been carried out in the field of topography, digital elevation modeling, agriculture, geological, crop, and precipitation mapping. However, no significant contribution to the development of geotechnical mapping has been made. For the appraisal of a geotechnical map, extensive field explorations were carried out throughout the geotechnically diversified plateau spread over an area of approximately 23,000 km2. In total, 450 soil samples were collected from 75 data stations to determine requisite index properties and soil classification for the subsequent allowable bearing capacity evaluation. The formatted test results, along with associated geospatial information, were uploaded to ArcMap, which created an initial input electronic database. The kriging technique of geostatistical analysis was determined to be more feasible for generating a geotechnical map. The developed map represents the distribution of soil in the region as per the engineering classification system, allowable bearing capacity, and American Association of State Highway and Transportation Officials (AASHTO) subgrade rating for 1.5-, 3.0-, and 4.5-m depths. The accuracy of the maps generated using kriging interpolation technique under spatial analyst tools was verified by comparing the values in the generated surface with the actual values measured at randomly selected validation points. The database was primarily created for the appraisal of geotechnical maps and can also be used for preliminary geotechnical investigations, which saves the cost of soil investigations. In addition, this approach allows establishing useful correlations among the geotechnical properties of soil