Characteristics Of Various Combinations Research Articles

Effect of waste stream materials on properties of cement mortars when used as supplementary binding materials

The present study focuses on the effect of waste stream materials on various properties of cement mortar when the waste materials are used as supplementary binding/cementitious materials (SCMs) for partial replacement of binding material. The effect and properties of various types of SCMs that are commonly used in mortar preparation replacing a part of cement (%) like limestone dust (LS), cement kiln dust (CKD), ground granulated blast furnace slag (GGBS), dolomitic limestone (DLS), ladle furnace slag (LDF), silica fume (SF), ceramic wastes (CW), fly ash (FA), pulverized fuel ash (PFA), waste glass sludge (WGS), etc. are studied and presented. Effects and characteristics of various combinations of different supplementary binding materials like the combination of FA with LS, an amalgamation of FA with DLS, the compatibility of FA with WGS, the mixture of GGBS with PFA, blending of GGBS with CKD, etc. are studied and reported. The elemental composition, pore size distribution system and microstructural composition were studied through X-ray diffraction (XRD), mercury intrusion porosimetry (MIP) and scanning electron microscope (SEM) and discussed. The results of the study revealed that a combination of GGBS and PFA yields better results than the reference mixes made of cement and other blended mixes made of SCMs. The performance of CW and WGS is found good at the later age. The performance of fly ash on mortar properties depended on the dosage and fineness of fly ash. Apart from their better solo performance, a combination of limestone dust and silica fume not only enhances the strength but also the sulphate resistance of mortar. The study revealed that the use of SCMs in mortar contributes to a reduction in cement production and carbon emission.

Durability assessment of high-performance concretes containing graphene oxide

The emphasis to reduce the cement utilization in construction has facilitated the use of mineral admixture resulting in an end product with enhanced performance characteristics in environments of severe exposures. The utilization of ternary and quaternary blends in construction industry been gaining prominence due to enhanced performance obtained because of the synergistic effects of various mineral admixtures. The work at present is focused on evaluating compressive strength and durability properties studies of high-performance concrete incorporating ash (FA), silica fume (SF) and graphene oxide (GO). The performance characteristics of various combinations of GO-FA, GO-SF and FA-SF-GO are assessed by formulating a suitable experimental programme. The experimental formulation was designed to evaluate the performance characteristics of concretes in marine environment where chloride and sulphate attack are highly prominent. Parameters were evaluated through various tests like Compressive Strength, Acid Attack test, Rapid Chloride Penetration test and Cyclic Wetting- Drying test. A relative comparison of results has been presented, shows that both the ternary and quaternary blended cement concrete containing combinations of GO-FA, GO-SF and FA-SF-GO have shown better results than the conventional concrete, mix proportions C8F2G4, C9S1G4, C7F2S1G4 containing 0.04% of GO are showing higher compressive strength values of 85, 74, 86 MPa for 365 days of fresh water curing, The highest resistivity values of 103, 109, 94 KΩ-cm are obtained for the quaternary blended cement mixes, Lowest RCPT values were achieved by mixes C7F2S1G2, C7F2S1G4, C7F2S1G8 corresponding to quaternary blends, The results of cyclic wet dry test have indicated the resistance to chloride permeability in concretes containing GO is very high in comparison to conventional concretes.

In vitro digestion characteristics of various combinations of elephant grass hay, gliricidia hay or silage, soybean meal and corn meal in rations for sheep

This study examined fermentation rates and kinetics of sheep rations based on combinations of elephant grass hay, gliricidia (Gliricidia sepium) hay or silage, soybean meal and corn meal using in vitro techniques. Three rations were prepared, namely: Control (elephant grass hay + soybean meal + corn meal); gliricidia hay (elephant grass hay + soybean meal + corn meal + gliricidia hay); and gliricidia silage (elephant grass hay + soybean meal + corn meal + gliricidia silage). A fixed ratio of roughage:concentrate of 55:45 was maintained for all rations, which were isocaloric and designed to support sheep gains of 200 g/day. The gliricidia replaced 57.6% of the soybean meal in the rations containing gliricidia and 81.8% of the elephant grass hay. Fermentation rates and kinetics, in vitro dry matter digestibility (IVDMD) and degradability of the rations were evaluated. Rations containing gliricidia as both hay and silage had higher (P<0.05) IVDMD than the Control ration (67.8 and 66.2 vs. 59.8%). The degradability of the ration containing gliricidia hay was higher (P<0.05) than that of the gliricidia silage ration (57.8 vs. 50.5%), whereas the Control showed an intermediate value (54.4%). The ration containing gliricidia hay and the Control produced more gas in the first 24 h than the ration containing gliricidia silage, and the gliricidia hay ration showed the shortest colonization time. Peak gas production occurred for the ration with gliricidia silage later than for the other rations. The study showed that substituting soybean meal with preserved gliricidia can result in higher digestibility of sheep rations. Feeding studies with animals are now warranted to verify these laboratory findings.

Comparison of radiopaque dye materials for localization of pulmonary nodules before video-assisted thoracic surgery.

BackgroundAlthough a mixture of pigments and radiopaque materials was reported to be useful material for lung nodule localization, the optimal combination has not been well investigated. The purpose of this study is to evaluate the characteristics of various combinations of pigments and radiopaque materials for localization of pulmonary nodules prior to video-assisted thoracic surgery (VATS).MethodsWe compared stability, viscosity, and visibility of 6 radiopaque dye materials of (I) mixture of indigo carmine and lipiodol; (II) mixture of indigo carmine, lipiodol, and lidocaine gel; (III) mixture of indocyanine green in water solution (w-ICG) and lipiodol; (IV) mixture of w-ICG, lipiodol, and lidocaine gel; (V) ICG in contrast medium solution (cm-ICG); and (VI) mixture of cm-ICG and lidocaine gel. Stability was evaluated by observing changes in the mixtures in the test tube with time visually and radiographically. Viscosities were measured by rotational viscometer. Materials were injected into an expanded pig-lung phantom, and area on CT and visibility on thoracoscopy camera were evaluated.ResultsSeparation could be seen 15 min after preparation in (I) and (III), and 1 h after preparation in (II), both visually and radiographically. In (IV), separation could be seen on the photographs but not on the X-ray images from 3 h after preparation. (V) and (VI) showed no changes within the 2-day observation period. The viscosities of the materials were (I) 0.2±0.1, (II) 2.9±0.1, (III) 0.2±0.1, (IV) 2.6±0.1, (V) 0.2±0.1, and (VI) 1.2±0.1 dPa·s. The area on CT showed very strong negative correlation with viscosity (r=−0.97). The injection point of each material was easily detected on thoracoscopy camera.ConclusionsRadiopaque dye materials appear useful for localizing pulmonary nodules before VATS; their diffusion in the lung parenchyma can be suppressed by using materials of high viscosity.

Study on the Microgrid Pluripotent Complementary and Comprehensive Economic Optimization Planning Based on Virtual Energy Theory

In this paper, a comprehensive economic allocation method based on virtual energy theory for microgrid complementary power supply is proposed, which is successfully applied to the multi energy complementary planning and comprehensive economic planning of an island microgrid. In order to evaluate and optimize the microgrid in the planning stage more objectively based on the characteristics of various combinations of renewable micro generation and flexible operation modes, a new method of the micro-grid comprehensive economic configuration and optimization of the distributed generation is proposed based on virtual energy theory. Firstly, the Micro-grid model structure based on the virtual energy theory is given. Secondly, the virtual energy conversion model of different distributed power generations is also studied. The micro-grid pluripotent complementary and comprehensive economic optimization model (PCCEP) based on virtual energy theory are reached too. Combined with a practical example, a PCCEP method of the micro-grid based on the Homer software platform is discussed. The case study indicates that the method can avoid the uncertainty of the decision-making factors and the subjectivity of expert evaluation. It is shown that the new method is a practical solution for microgrid comprehensive economic optimization planning.

Comparison of electrophysical characteristics of various combinations of the polypropylene-polyethylene terephthalate dielectric impregnated with transformer oil T-1500 and polymethylsiloxane liquid PMS-20

The article considers the results of the studies on the electrophysical characteristics of various combinations of the impregnated dielectric polypropylene and polyethylene terephthalate films, which can be applied as the working insulator of a high-voltage pulse capacitor’s sections. Experiments on mockups of the capacitor’s sections served as a basis for the analysis of the influence of polarity of the films and capacitor plates on the electrical insulation resistance and short-term dielectric strength of such dielectric systems. Recommendations for using dielectric systems as capacitor insulation are provided.

Microstructure and Wear Behaviour of Aluminium Metal Matrix Composites Reinforced With Mg-Sic-TiO2-flyash

Al6061 was particulate with various reinforcement composite metal matrix materials adding different matrices using stir casting method. Reinforcement of hybrid composites used to various kinds of applications such as good wear resistance, electrical semiconductor and development of mechanical properties. The characteristics of various combinations of Aluminium reinforcement material were investigated. Wear behavior has investigated by using pin-on- disc mechanism. Using Scanning Electron Microscope (SEM) examined in this investigation. Using optical microscopic to identifying the various worn surfaces such as Ploughing, debris and oxide layer. Pin-on-wear mechanism were carried out the reinforcement of Aluminium with different prepared composites of wear parameters such as sliding distance 300mm, sliding speed 2.5m/s and applying load 5N, 10N, 15N. This analysis result focused on minimum wear, coefficient of friction, frictional load and temperature effect. Experimental result shows the amount of adding composite particles to increasing the wear resistance and decreasing wear losses. From the effect of wear as curve fitting technique was applied for the polynomial and power law equation. These equations of R2 value higher than power law equations and much agreed with the experimental observation.

Biomarkers and Clinical Prediction Rules in the Diagnosis of Suspected Deep Vein Thrombosis: A Comparison of Cancer and Non-Cancer Patients

Introduction: Despite efforts toward prevention, thousands of patients suffer from venous thromboembolic disease (VTE), consisting of deep vein thrombosis (DVT) and pulmonary embolism (PE), each year; this results in significant morbidity and mortality. Clinical prediction rules, such as the Wells score, in conjunction with biomarkers like the D-dimer, are suggested by national guidelines to aide in evaluating for DVT. Substantial interest exists in developing improved diagnostic testing strategies and algorithms to limit the need for more costly, time consuming, and/or invasive testing. Novel biomarkers, like the soluble P selectin (sP-Sel), a cell adhesion molecule that functions to mediate thrombus formation and amplification, have shown promise in this area.While cancer patients suffer from a high burden of VTE, the D-dimer and Wells score are less helpful in this group. This is due to non-specific D-dimer elevations in these patients, and cancer being part of the Wells risk stratification schema. We sought to identify a more specific combination of biomarkers and Wells score, for the diagnosis of DVT that would apply to cancer patients as well.Methods: We previously performed a prospective cohort study of adults presenting with symptoms of DVT afflicting the upper or lower extremities (Vandy et al. J Vasc Surg Venous Lymphat Disord., 2013). Patients were enrolled from December 2008 to July 2013. Those with isolated calf DVT, superficial venous thrombosis, pregnant or breastfeeding, on therapeutic anticoagulation, or with symptoms of simultaneous upper and lower DVT were excluded. After informed consent was obtained, clinical characteristics and biomarkers (D-dimer, C-reactive protein (CRP), Von Willebrand Factor activity (VWF), and sP-Sel) were collected, and duplex ultrasonography was performed to determine if DVT was present. In this subset analysis, cancer patients were compared to non-cancer patients with regards to thrombotic risk factors, biomarker values, and to assess the test characteristics of various combinations of biomarkers and Wells score.Results: A total of 373 patients were enrolled, 151 (40%) in the cancer group, compared to 222 (60%) in the non-cancer group. Cancer patients were more likely to have a DVT on confirmatory testing (58.9% vs. 43.2%). Cancer patients tended to be older, male, have a lower BMI, more recent acute illness, and more central lines, relative to the non-cancer group. Non-cancer patients were more likely to have other potential risk factors for thrombosis, i.e. recent surgery, oral contraceptive use, and a family history of thrombosis. Biomarker values for CRP and sP-Sel were similar, however VWF and D-dimer values were significantly higher in the cancer patients (see table).D-Dimer > 500 with Wells score ≥ 2 was less specific for the diagnosis of DVT among cancer patients compared to non-cancer patients (p=0.003). However, D-Dimer ≥ 500 with sP-Sel ≥ 90 showed not only high specificity, but that specificity was not different between the cancer and non-cancer populations (p=0.88). sP-Sel ≥ 90 and Wells ≥ 2 had similar performance characteristics in both groups as well (p=0.54 for specificity, p=0.14 for positive predictive value (PPV)).Conclusion: Co-morbid risk factors for thrombosis among cancer patients included an older age, male gender, and an increased use of central lines. This group was less likely to have other potential thrombotic risk factors like family history or recent surgery.Our results concur with the finding that the D-dimer, combined with a clinical prediction rule, is not as helpful for DVT in cancer patients. Moreover, this study further supports sP-Sel as a specific test for DVT, that can be combined with clinical information (Wells score) or other laboratory data (D-dimer) to reflect the presence of DVT and potentially rule in clot; the test seems equally useful for both cancer and non-cancer populations. This could potentially be used to guide initial patient management in scenarios where imaging or further testing is not immediately available, such as in an outpatient clinic or rural area. Further exploration of the optimal strategy for utilizing biomarkers and clinical prediction rules in the diagnosis of DVT in cancer is needed. [Display omitted] DisclosuresSood:Bayer: Research Funding.

Design parameters for geosynthetic dewatering tubes derived from pressure filtration tests

ABSTRACT: Geosynthetic tubes are increasingly being used for dewatering projects processing many different types of sludge, such as dredged materials, industrial and sewage sludge. Although there is still a lack of reliable design procedures, especially with respect to determination of the time needed for the dewatering of sludge inside a geosynthetic tube, a variety of scientific publications have applied pressure filtration tests to determine the one-dimensional filtration and consolidation characteristics of various combinations of sludge and geotextile filters. A series of pressure filtration tests were conducted on different combinations of dredged materials and geotextile filters to observe the benefits and limitations of the method with respect to geotextile tube dewatering. In this paper the application possibilities and derived values of pressure filtration tests are discussed. The main limitations could be detected for those derived values that are dependent on the test set-up. Each of the research institutes that has published on pressure filtration testing used a different apparatus. Thus the dependence of the derived results on the specific test set-up limits both the analysis itself, and the comparability of results. In particular, the value of filtration efficiency, which has frequently been used by researchers, proved to be of little significance in describing a filtration project.

Insulating System to Reduce the Amount of Oil in Electric Power Apparatus Using Silicone Oil

The lightning impulse breakdown characteristics of various combinations of insulation material in silicone oil for use in electric power apparatus were investigated, with the aim of reducing the amount of oil required and thus the cost. Breakdown characteristics were investigated in a system in which an insulating filler was mixed with silicone oil. Tests were conducted on a sphere-plane electrode in a vertical arrangement and a sphere-sphere electrode in a horizontal arrangement. The relation between the breakdown strength and the electric field strength was clarified. Breakdown characteristics were also investigated in a system in which am insulator with low relative permittivity was inserted between a filler with high relative permittivity and the high-voltage electrode. Based on the findings, optimum conditions for the application of silicone oil to electric power equipment are proposed.

Electromechanical analysis of electrostatic nano‐actuators using the differential quadrature method

AbstractThe nonlinear analysis of nanoelectromechanical systems using the differential quadrature model is investigated. The differential quadrature method is applied to overcome the difficulty of determining the nonlinear equation of motion. The characteristics of various combinations of curved electrodes and cantilever beams are considered to optimize the design. Various nano‐actuators, such as the cantilever beam actuator, are derived and simulated to examine the feasibility of applying the differential quadrature method to the nonlinear deflection in solving the nano‐actuator problem. The effects of the electrode shapes, the lengths of the actuators, and the moments of inertia of the actuators on the pull‐in behavior of the cantilever actuators in electrostatic nanoelectromechanical systems are investigated. The differential quadrature approach is used to generate the electrostatic field equations in matrix form. Copyright © 2007 John Wiley & Sons, Ltd.

Effect of combinations of wood and counterface materials on three-body abrasive wear

The abrasion characteristics of various combinations of wood and counterface materials in three-body abrasive wear were investigated. Various wood samples were examined in combination with wood, plastic, and metal counterface materials. The wear coefficient in the wood samples was calculated as the wear volume of the friction surface divided by the sliding distance and the applied load. The results showed that the wear coefficient was smaller in cases where the wood samples had greater yield stress. The wear coefficient increased as the yield stress of the various counterface materials increased, reaching a maximum value and then decreased as the yield stress increased. This result indicated that a peak value existed for the wear coefficient in combination with the counterface material.

Experimental study on a hybrid photovoltaic-thermal solar water heater and its performance predictions

The combined photovoltaic-thermal system is a new kind of solar system which, so far, has not seen intense research and developmental activities as other systems have seen. The most attractive feature of such a system is that it could produce both electrical and thermal energies from the same panel. These systems could play an important role in popularizing solar energy. In order to understand and evaluate solar hybrid systems, an experimental study was undertaken. The system chosen is a thermosyphon water heater with solar cells. The cells are pasted directly over the absorber plate. The solar insolation falling on the aperture area of the collector is concentrated on the solar cells using a simple parabolic reflector. The temperatures at several points in the system (or the absorber at several points, of the solar cells, of the water in the tank at several positions, of the inlet and outlet water from the collector) are measured by using thermocouples. The solar cells are arranged in three groups. Among a group, the solar cells are connected in series. The three groups can be connected either in parallel or series. The electrical characteristics of the cells, i.e., the I-V characteristics of various combinations with several different load resistances are measured. The experiment was performed for several days with thermosyphon flow and without it. The heat transfer coefficients, heat loss coefficient of the tank and overall heat loss coefficient of the collector are determined from experimental data. An attempt is made to fit the various experimental observations, like water temperature in the tank, inlet and outlet water temperatures of the collector, with the well known model of thermosyphon solar water heaters. The model equations are modified to include the presence of the solar cells and the reflectors. The agreement between the experimental and theoretical predictions, within the experimental errors, is excellent.

Association with BiP and aggregation of class II MHC molecules synthesized in the absence of invariant chain.

Class II molecules of the major histocompatibility complex (MHC) are composed of two polymorphic glycoprotein chains (alpha and beta), that associate in the ER with a third, non-polymorphic glycoprotein known as the invariant chain (Ii). We have examined the relationship between the intracellular transport and physico-chemical characteristics of various combinations of murine alpha, beta and Ii chains. Biochemical and morphological analyses of transfected fibroblasts expressing class II MHC chains show that both unassembled alpha and beta chains, as well as a large fraction of alpha+beta complexes synthesized in the absence of Ii chain, are retained in the ER in association with the immunoglobulin heavy chain binding protein, BiP. Analyses by sedimentation velocity on sucrose gradients show that most incompletely assembled class II MHC species exist as high molecular weight aggregates in both transfected fibroblasts and spleen cells from mice carrying a disruption of the Ii chain gene. This is in contrast to the sedimentation properties of alpha beta Ii complexes from normal mice, which migrate as discrete, stoichiometric complexes of M(r) approximately 200,000-300,000. These observations suggest that assembly with the Ii chain prevents accumulation of aggregated alpha and beta chains in the ER, which might relate to the known ability of the Ii chain to promote exit of class II MHC molecules from the ER.

Scuffing behavior of TiN-coated steel rollers under rolling and sliding conditions

Sputtered hard coatings were applied to steel surfaces to evaluate their performance in adhesive wear environments. Rolling and sliding tests were conducted to investigate the scuffing-wear resistance of coated rollers. Coatings were deposited separately on drive or driven rollers and on both rollers. For the cases of relatively smooth surfaces, the test results showed that sputtered coatings significantly increased the scuffing resistance over those of steel rollers without coatings. The friction and wear characteristics of various combinations were compared to identify their advantages. For the cases of relatively rough contact surfaces, coating only the drive roller increased the scuffing-failure load by at least five times over the case of uncoated rollers. When only the driven roller was coated or when both rollers were coated, the scuffing-failure load was not increased significantly. The surface roughness of contact pairs played an important role in the scuffing-wear properties under the present rolling and sliding conditions.

The effect of rate of force application on the properties of microcrystalline cellulose and dibasic calcium phosphate mixtures

The effect of rate of force application over the range 24-1100 mm/s on the compaction characteristics of various combinations of a microcrystalline cellulose (MCC) and dibasic-calcium phosphate dihydrate (DCP) have been studied using mean yield pressure, extent of particle rearrangement ( D b ) obtained from Heckel analysis, tablet radial tensile strength and elastic recovery as the basis of the investigation. A simple relationship was observed with increasing mass fraction of MCC on mean yield pressure and elastic recovery of the compacts. At all rates of force application, mean yield pressure decreased while elastic recovery increased with increasing mass fraction of MCC, ascribed to the dominating effect of plastic deformation of the microcrystalline cellulose. No simple relationship was observed with properties such as extent of particle rearrangement ( D b ) and tensile strength. In some cases the properties of some mixtures were greater than or less than either of the two pure components. At all rates of force application, 25% w/w of MCC and 75% w/w DCP resulted in peak values for D b , which can be ascribed to a decrease in frictional and cohesive forces between particles. Higher concentrations of MCC resulted in a decrease in D b due to adhesion of the particles, which reduces the extent of particle slippage and rearrangement towards a minimum between 75 and 100% w/w MCC. The tensile strength of the mixtures decreased with increasing rate of force application. Increasing levels of MCC increased tensile strength and a plateau was obtained at 50–75% w/w MCC at all rates. 75% w/w MCC produced tablets with higher tensile strength than the individual materials respectively, due to extensive fragmentation of DCP which enhanced the filling of void spaces during compression leading to optimum force utilization, improved consolidation and better bonding of MCC. It appears from this study that a mixture of 25% w/w DCP and 75% w/w MCC may have advantages over the individual materials.

Variable-Voltage Oil Well Drilling Equipment Comparison of Characteristics of Various Combinations of Motors and Generators

In the past, there have been many operating data taken and used in the comparison of the characteristics of various types of prime movers. However, there has never been a method established for the comparison of these equipments on a common basis. In this paper, such a method has been proposed. Although it deals only with internal combustion engine direct-current electric drives, with varying electrical characteristics, this method may be advantageously used for the comparison of other types of prime movers.