Properties Of Different Materials Research Articles

Theoretical and numerical investigation of introduced errors in surface temperature measurements of pistons applied in internal combustion engine

DMP (Differences in Material Properties) often exists between temperature sensors and combustion chamber components of ICE (Internal Combustion Engine), resulting in IEs (Introduced Errors) in the temperature measuring process. In this paper, we present a comprehensive theoretical analysis of the correlation between introduced errors on chamber components and the DMP. The analysis process considers the characteristics of the chamber's heat transfer BC (Boundary Condition). Then, simulations are used to investigate the introduced error of hardness plug and thermocouple sensors on the top surface of an ICE aluminum alloy piston. The theoretical analysis results indicate that heat transfer BC can be segmented into the time-averaged and fluctuation parts, and IEs are linearly superimposed under these two parts of BCs. The heat conductivity impacts the time-averaged error and the product of heat conductivity, density, and heat capacity impacts the fluctuation error. The experimental and simulation results indicate that the max time-average error of the hardness plug on piston is 2.4 °C, with a fluctuation introduced error of 3.6 °C and a total introduced error of 6 °C; and the time-average introduced error of thermocouple sensor is 9.4 °C, with a fluctuation error of 5.8 °C and a total introduced error of 15.2 °C. Finally, a fluctuation error correction method is proposed to reduce error. After correction, the error is reduced by 71 % and 66 % for hardness plug and thermocouple, respectively.

Casting of Recycled Aluminum Cans to Electrical Conductivity Tape Production

This research presents a methodology for the recycling process via casting, in which aluminum cans and primary aluminum are transformed into a laminated tape, with the possibility of industrial application. Its objective was to incorporate materials of different properties that could favor the making of a laminated tape.

Material Selection for Diabetic Custom Insoles: A Systematic Review of Insole Materials and Their Properties

ABSTRACT Introduction Diabetic foot ulceration is one of the most significant causes of infection and amputation in neuropathic patients. Most often, the plantar surface of the foot is affected. Offloading the foot by custom-molded insoles is considered a crucial step in prevention of diabetic foot ulcers, although the most beneficial choice of materials is not well documented. This review focuses on identifying the most suitable materials and material compositions for offloading the diabetic foot. Materials and Methods A systematic review was performed with the aid of a clinical librarian on September 9, 2020. The review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. Studies were included based on the following eligibility criteria: interventions in terms of material selection/properties with outcomes reported as either pressure reduction and/or ulcer prevention. Bench studies were also included. At each level of selection, records were reviewed by two independent reviewers. Clinical studies were appraised using the ROBINS-1 tool. Results Through database search, 1131 records were identified and an additional eight records were identified through references and other sources. After removal of duplicates, 927 records were screened, which resulted in 74 full-text records assessed for eligibility. Thirty-seven studies were included in the qualitative synthesis. Twelve studies examined material properties by bench testing. Five studies were based on finite element analysis. Nineteen clinical studies on material parameters were identified. Six studies supported the use of moderately deformable materials for insole production. Six studies showed better performance of combination material insoles in offloading and under sustained loading. Five studies concluded that increasing the thickness of insoles increased the offloading capabilities. Conclusions The diversity of studies and study designs to date precludes the ability to recommend one type of material over the other. Still some general considerations can be made. For solo-material insoles, moderately deformable materials are preferable, balancing the need for offloading with the need for durability. Increasing the thickness may increase the longevity of the insoles. Combining materials of different properties seems to enhance both the offloading capability and durability of insoles. Clinical Relevance When using a single-material design, moderately deformable materials are preferable. Combining materials of different properties enhances both the offloading capability and durability of insoles.

Transforming a Two-Dimensional Layered Insulator into a Semiconductor or a Highly Conductive Metal through Transition Metal Ion IntercalationSupported by the National Key Research and Development Program of China (Grant Nos. 2017YFA0403600 and 2016YFA0300404), the National Natural Science Foundation of China (Grant Nos. 11874363, 11974356 and U1932216), and the Collaborative Innovation Program of Hefei Science Center, CAS (Grant No. 2019HSC-CIP002).

Atomically thin two-dimensional (2D) materials are the building bricks for next-generation electronics and optoelectronics, which demand plentiful functional properties in mechanics, transport, magnetism and photoresponse. For electronic devices, not only metals and high-performance semiconductors but also insulators and dielectric materials are highly desirable. Layered structures composed of 2D materials of different properties can be delicately designed as various useful heterojunction or homojunction devices, in which the designs on the same material (namely homojunction) are of special interest because preparation techniques can be greatly simplified and atomically seamless interfaces can be achieved. We demonstrate that the insulating pristine ZnPS3, a ternary transition-metal phosphorus trichalcogenide, can be transformed into a highly conductive metal and an n-type semiconductor by intercalating Co and Cu atoms, respectively. The field-effect-transistor (FET) devices are prepared via an ultraviolet exposure lithography technique. The Co-ZnPS3 device exhibits an electrical conductivity of 8 × 104 S/m, which is comparable to the conductivity of graphene. The Cu-ZnPS3 FET reveals a current ON/OFF ratio of 105 and a mobility of 3 × 10−2 cm2⋅V−1⋅s−1. The realization of an insulator, a typical semiconductor and a metallic state in the same 2D material provides an opportunity to fabricate n-metal homojunctions and other in-plane electronic functional devices.

Thermal and evaporative resistance measured in a vertically and a horizontally oriented air gap by Permetest skin model

This paper is a study of the correlation of the thermal resistance (Rct ) and the evaporative resistance (Ret ) in vertically and horizontally oriented air gaps by using the portable Permetest skin model. Experiments were done in a climatic chamber; an isothermal condition for Ret tests and non-isothermal condition for Rct tests. Foamed polyethylene air gap distance rings were prepared with a thickness of 2, 4 and 5 mm and their combinations to simulate the air gap distance from 0 to 16 mm which is more than the expected average gap in clothing systems. Test samples were woven fabric of 100 percent cotton, 100 percent polyester and their blends plus 100 percent of polypropylene, all have similar weight and structure. Results showed that with the increasing thickness of the air gap, Rct increased in a polynomial trend and Ret in a linear proportional rate up to 12 mm then started to change due to the effect of free convection and the different properties of materials. The surprising positive observation is that results from the horizontally and vertically oriented air gaps are very similar, and most of the results from the vertical air gap are slightly lower than the results from the horizontal air gap in all materials.

Experimental and Analytical study on the elastic properties of HDPE/SWCNT nanocomposites

The development of new materials which possesses specific properties for explicit engineering applications has proven to be a key issue in modern researches and manufacturing industries. This is influenced by the necessity of novel and advanced materials in the aerospace, automotive, biomedical and other industries. One possible solution for progressive material development is a combination of two or more materials of different properties which results with a composite material of improved properties compared to the constituent materials. If one face of materials in a composite material is at the nanoscale the subsequent material is said to be nanocomposite. In this work, High-Density Polyethylene (HDPE) was reinforced with Single-walled Carbon Nanotubes (SWCNTs) nanoparticles at different weight fractions to result with HDPE/SWCNTs nanocomposites. The produced HDPE/SWCNTs nanocomposites were processed according to injection and compression mouldings. The experimental approach was then used to investigate the effect of the two processing approaches and the consequences of adding SWCNTs nanoparticles weight fraction on the elastic properties of the HDPE matrix. The results showed that addition of SWCNTs improves the elastic properties of HDPE/SWCNTs nanocomposites in both processing techniques. Furthermore, injection moulding proved to be better processing method of enhancing the elastic properties of the nanocomposites compared to compression moulding. Finally, three analytical models were used for validation and it was found that the approximation model and model of Pan gives acceptable predictions linking to the experimental results compare to the rule of mixture model.

Mechanical properties and morphological study on palm Fiber/S-Glass reinforced polymer matrix composites

This investigation examine the polymer matrix composite material prepared from 32 wt% epoxy resin LY556 and 3 wt% hardener HY951 with Palm fiber (30 wt%, 20 wt%, 10 wt%) and S-glass. Composite materials are made by reinforcing at least two materials of different properties. Hybrid Composite materials are framed by combining natural and synthetic fibers. In this study based on the physical, synthetic and mechanical properties of the chosen materials the necessary epoxy resin LY556 and hardener HY951 are picked and fabricated accordingly by using hand lay-up method. The test specimens are cut as per the ASTM standards using waterjet cutting. Different tests were conducted to assess the Mechanical properties like tensile strength, flexural strength, impact strength and hardness of the hybrid composite material. The morphological study used to identify the structure of the composite material is done by using scanning electron microscope. The elemental analysis also examined using SEM-EDX. The test results show that the specimen 1 (30 wt% palm fiber) which have the better strength, firmness, high strength to weight ratio and other mechanical properties compared to other specimens 2 (20 wt% palm fiber) and 3 (10 wt% palm fiber). The morphological properties show that the composite materials have good bonding properties. The SEM-EDX analysis show that the composite material has 49.64% carbon which is a high strength element used for structural applications.

Computational phonogram archiving

A general approach to analyzing audio files makes it possible to re-create the sound of ancient instruments, identify cross-cultural musical properties, and more.

Topochemical synthesis of different polymorphs of polymers as a paradigm for tuning properties of polymers

Different packing is a mechanism through which nature can produce materials of different properties from the same basic units. There is great interest in constructing different forms of the same polymer by utilising different packing. Common solution-synthesized polymers are amorphous and their post-synthesis crystallization into different topologies is almost impossible. Here we show solid-state polymerization of different reactive polymorphs of a monomer pre-organized in different topologies. Trimorphs of a dipeptide monomer pack in a head-to-tail fashion, placing the azide and alkyne of adjacent monomers in proximity. On heating, these crystals undergo a topochemical azide-alkyne cycloaddition reaction yielding triazole-linked polymer in three different crystalline states; one with antiparallel arrangement of polymer chains, another with parallelly oriented chains, and a third form containing a 1:1 blend of two different conformers aligned in parallel. This approach of exploiting different polymorphs of a monomer for topochemical polymerization to yield polymorphs of polymers is promising for future research.

Development and Testing of Advanced Cork Composite Sandwiches for Energy-Absorbing Structures.

Cork is a sustainable material with remarkable properties. In addition to its main application as wine stoppers, it has also been employed as a sound and thermal insulator in facades, building roofs, aeronautical applications, and, more recently, in impact energy absorption systems. In its natural form, cork is mainly used in wine stopper manufacturing, but for other applications, cork compounds are usually employed, which makes it possible to manufacture complex geometries with nearly isotropic behavior. In this work, an attempt was made to merge the desirable properties of two different cork materials (agglomerated and expanded black) into cork composite sandwich structures. These structures were tested according to impact conditions typically experienced by energy-absorbing liners used in personal safety devices. Additionally, the performance dependency on the working temperature was analyzed. The sole black, expanded cork (EC159) and agglomerated cork (AC199A and AC216) were tested in 500 J impacts. It was found that black cork was characterized by superior thermal stability, while expanded cork allowed absorbing high energies. In the second stage, the composites consisting of both tested materials were tested in 100 J impact scenarios. The combination of two materials of different properties enabled reduction of the peak force exerted on a helmet user’s head during the impact by about 10% compared to agglomerated specimens. Additionally, it was proved that there was no influence of the glue used to join different cork types.

Synthesis and Nano-Characterization of Graphene Single- and Few-Layer Films

Two-dimensional materials (2DM) rapidly gained the attention of material scientists, physicists, and engineers due to breadth of their electronic properties, often combined with good mechanical and thermal functionality. Among these materials, graphene, certainly, is the best studied material with the most mature applications. Therefore, scalable synthetic technologies for growing at will various graphene materials of different properties are of paramount importance for both industry and academia.

Effect of replacement strike-face material on the ballistic performance of multi-ply soft armor targets

In this study, the impact-face material of a multi-ply soft armor system was varied to different ratios and tested for the effects on the ballistic performance. It is known that the first few layers of multi-ply soft armor material typically fail inelastically near the system ballistic limit and can be replaced with a “sacrificial” material with other more desirable properties. Previous studies have determined that the ballistic performance of these hybrid systems is largely dependent on the amount of high-performance backing material. However, the extent to which the high-performance fabric can be replaced has yet to be fully quantified and examined. Materials of different properties, namely stainless steel mesh, Makrolon® polycarbonate sheets, and cotton, were used as replacement frontal material for 840 d Twaron® panels, and the hybrid panels were impacted by O1 tool steel right-circular cylinder projectiles fired using a single-stage smooth-bore gas gun. Results show that the ballistic performance is maintained up to a frontal material ratio of about 40%, and off-axis material properties play a role in energy dissipation.

Tensile Stress Analyses through Digital Image Correlation of Single Lap Joints of High Strength Steel and Aluminum Alloy Using Adhesive Bonding

Structural adhesives methods for joining multi material sheets have been focus of studies and researches for the last years. The most common and widely known type of test is the tensile test of single lap joints (SLJ). However, there are opportunities for analyzing the mechanical performance of such method in SLJ with materials of different properties, such as ductile structural aluminum alloys and high strength steels. It’s also known that the stress state of SLJ, when stressed longitudinally, generates secondary forces. One of them is known as cleavage force which initially leads to the failure of bonded joints. The aim of this work is to analyze the stress state of similar and dissimilar materials SLJ submitted to tensile stresses and also the influence of some variables, such as overlap length, adhesive film thickness and adherend yield limit, over the stress strength of the samples. As adherend materials it was selected the structural aluminum alloy AA 5083 H111 and the high strength steel DP600. At the end of this work it is expected to understand the proper stress state of the SLJ when using similar and dissimilar materials, identifying stress concentrators that bring the structure to fail, using the Digital Image Correlation (DIC) method. It was discovered that the yield strength associated with the overlap length highly influences the SLJ strength, by leading it to a close to pure adhesive shear stress state.

Hook tool manufacture in New Caledonian crows: behavioural variation and the influence of raw materials.

BackgroundNew Caledonian crows use a range of foraging tools, and are the only non-human species known to craft hooks. Based on a small number of observations, their manufacture of hooked stick tools has previously been described as a complex, multi-stage process. Tool behaviour is shaped by genetic predispositions, individual and social learning, and/or ecological influences, but disentangling the relative contributions of these factors remains a major research challenge. The properties of raw materials are an obvious, but largely overlooked, source of variation in tool-manufacture behaviour. We conducted experiments with wild-caught New Caledonian crows, to assess variation in their hooked stick tool making, and to investigate how raw-material properties affect the manufacture process.ResultsIn Experiment 1, we showed that New Caledonian crows’ manufacture of hooked stick tools can be much more variable than previously thought (85 tools by 18 subjects), and can involve two newly-discovered behaviours: ‘pulling’ for detaching stems and bending of the tool shaft. Crows’ tool manufactures varied significantly: in the number of different action types employed; in the time spent processing the hook and bending the tool shaft; and in the structure of processing sequences. In Experiment 2, we examined the interaction of crows with raw materials of different properties, using a novel paradigm that enabled us to determine subjects’ rank-ordered preferences (42 tools by 7 subjects). Plant properties influenced: the order in which crows selected stems; whether a hooked tool was manufactured; the time required to release a basic tool; and, possibly, the release technique, the number of behavioural actions, and aspects of processing behaviour. Results from Experiment 2 suggested that at least part of the natural behavioural variation observed in Experiment 1 is due to the effect of raw-material properties.ConclusionsOur discovery of novel manufacture behaviours indicates a plausible scenario for the evolutionary origins, and gradual refinement, of New Caledonian crows’ hooked stick tool making. Furthermore, our experimental demonstration of a link between raw-material properties and aspects of tool manufacture provides an alternative hypothesis for explaining regional differences in tool behaviours observed in New Caledonian crows, and some primate species.Electronic supplementary materialThe online version of this article (doi:10.1186/s12915-015-0204-7) contains supplementary material, which is available to authorized users.

Analysis of Factors influencing Galvanized Sheet Friction based on Orthogonal Experiments

During forming process of sheet metal, friction phenomenon occurs everywhere. Galvanized sheet is the combination of substrate and zinc coating, which are two different materials of different properties. Compared with ordinary cold-rolled steel sheets, friction during forming process of galvanized sheet is more complicated. Factors like load, velocity, etc. have different effects. In this paper, effects of zinc coating, velocity and load on galvanized sheet friction coefficient were researched based on orthogonal tables with using friction wear tester. The results show the following conclusions. Zinc coating has great effect on galvanized sheet friction, friction coefficient of zinc-coated sheet is greater than that of bare board under low load (0.3~1 N), but smaller than that of bare board under high load (1~5 N). Galvanized sheet friction coefficient also changes when load or velocity changes, with load increases, it first increases and then decreases; with velocity increases, it first increases and then decreases. Mechanism of the influence rules above was simply analyzed. Significance of the three factors above could also be seen. Under low load, effect of zinc coating on galvanized sheet friction coefficient is the greatest, followed by that of load, and finally that of velocity, but none of them is significant; under high load, effect of zinc coating is significant, those of velocity and load are not significant.

Removal of radionuclides from Estonian groundwater using aeration, oxidation, and filtration

Groundwater in the north-eastern suburb of Tallinn was analysed to determine the content of iron, manganese, sulphides, ammonia, and radionuclides (Ra 226 , Ra 228 ) and total radioactivity. It was established that for several wells of the Cambrian-Vendian water layer the annual effective dose would exceed the EU guideline for drinking water (0.1 mSv/yr). The purpose was to find a technology for simultaneous purification of groundwater from iron, manganese, sulphides, ammonia, and some radionuclides (Ra 226 , Ra 228 ). A pilot plant consisting of a Venturi-type aeration unit GDT (Gas-Degas Technology, Mazzei Corp., USA), an oxidation tank, and two-stage filtration columns was constructed. Several non-catalytic (Everzit Special Plus, sand) and catalytic filter materials (Filtersorb FMH, Pyrolox) were tested. Along the flow sheet from the aerator to the II stage filter outlet the pH, dissolved oxygen and carbon dioxide, turbidity, the content of iron, manganese, and ammonia were monitored, mainly by using spectrophotometry (HACH DR/2000). Radioactivity of water samples was determined by the Estonian Radiation Centre using the liquid scintillation counting method and γ-spectrometry. It was established that by intensive aeration of groundwater followed by oxidation for a certain contact time and appropriate selection of filter materials of different properties, it was possible to remove together with iron and manganese also radium isotopes. The total effectiveness of the process was 90% removal of gross-alfa and 70% removal of gross-beta activity of groundwater. Since the uranium content in the well water was marginal and radon was almost totally (99%) removed in the degas separator, the total effective dose was calculated by Ra 226 and Ra 228 . It was about 0.067 mSv/yr, which is lower than the EU DWD guideline (0.1 mSv/yr). The theoretical assumption that radionuclides were already removed with Fe(OH)3 flocks in the first filtration step was verified by examining wash water. The radioactivity of wash water containing precipitate and the filtered wash water were measured. Results showed 4.6 times higher gross-alfa and 5.3 times higher gross-beta activity in the water containing precipitate. The co-precipitation process, where MnO2 and Fe(OH)3 flocks played an essential role, resulted in simultaneous removal of radium isotopes. Co-precipitation of radium with MnO2 was more effective than with Fe(OH)3.

Experimental Validation of Thin‐layer Drying Models

AbstractThe present work was aimed at investigating the applicability of the proposed correlation equations that link the coefficients of the thin‐layer equations. Materials of different properties were chosen and dried in four types of laboratory dryers. The experimental data were approximated applying the commonest thin‐layer equations: the Lewis equation, the modified Page's model, and Fick's second law. The best match was achieved with the modified Page's model. The applicability of the stated literature correlations was confirmed. Irrespective of the match between measuring data (X = f(t)) and Lewis equation, the evaluated drying constant K allowed evaluation of the parameters of the employed two‐parameter models.

Modelling of strain fields in quantum wires with continuum methods and molecularstatics

The maximum and minimum principal strains of an InAs quantum wire (QWR) buried in aGaAs matrix are computed using the boundary element method (BEM), the inclusionmethod, and molecular statics, and the results from each method are comparedwith each other. The first two methods are based on continuum mechanics andlinear elasticity, while the third is atomistic. The maximum principal strains arelargely in agreement among the different methods, especially outside the QWR,though in the centre of the QWR, the discrepancy between the continuum andatomistic methods can be as large as 11.9%. The gradients of the strain tensor are inagreement among the methods. The inclusion method is faster than the BEM,and both continuum methods are an order of magnitude faster than molecularstatics. Although the inclusion method, unlike the BEM, ignores the difference inmaterial properties between the QWR and its surrounding matrix, its results are inbetter agreement with the molecular statics results than the results from theBEM. The rough quantitative and qualitative agreements indicate the utility ofclassical continuum methods for estimating strain profiles in nanoscale structures.

Surface Enhancement of Al2O3 Fiber With Nanosized Al2O3 Particles Using A Dry Mechanical Coating Process

Currently, fabrication of composite materials is of great interest in industry. By combining materials of different properties, we can produce new composite materials with synergetic functionality that individual materials do not possess. In this study, Al2O3 nanosized particles were coated on Al2O3 fiber substrates using a dry mechanical coating technique employing high shear and compression forces. The materials thus synthesized had high surface area with good dispersion for enhanced reactivity and were strong to sustain rigorous operation. Operating parameters, including rotor speed, processing time and initial loading percentage were varied to study their effects on the coating condition. The experimental results showed that the product surface area increased as the nanoparticle loading increased. The dispersion of nanoparticles improved as the processing time increased. A higher rotor speed resulted in a shorter product length while the nanoparticle loading had no effect on the product length. The durability test, conducted in a fluidized bed, indicated no significant change of the coating layer after 7 days of continuous testing.

Research on the non-linear temperature field of molten metal shaped by an electromagnetic field in DS processing

A new directional solidification (DS) technique, combining electromagnetic shaping with liquid metal cooling, is established to confine and shape liquid metal by an electromagnetic field without the mold and carry out DS with a high-temperature gradient. The motion of the sample, heat radiation, and especially the material-property difference between the solid and the liquid, are considered for electromagnetic heating. Thereafter, a non-linear temperature model is established to calculate the position of the solid/liquid interface with respect to the furnace, the height of liquid metal and the temperature distribution in stainless-steel samples. The results of calculation are in good agreement with experimental measurements. On the basis of the model, experimental parameters, such as the intensity of cooling, and the current in the induction coils, can be further optimized so as to control the morphology of the solid/liquid interface, the temperature gradient and the axial temperature distribution in the liquid metal. A FEM approach is developed in this paper.