Use Of Reinforcement Research Articles

Functional 3D-Printed Polymeric Materials with Metallic Reinforcement for Use in Cut-Resistant Gloves.

Given the mechanical hazards occurring in the workplace, cut resistance is a particularly important protective parameter. 3D printing is an innovative technology that has recently garnered great interest. It enables the creation of functional polymeric materials with metal reinforcement for use in cut-resistant gloves. The present study characterized and tested 3D-printed polymeric materials intended for such applications. The materials were made from commercially available 3D printing polymer filaments. Metallic reinforcement (stainless steel wire with a diameter of 0.04 mm) was added to the two selected materials (thermoplastic polyurethane and FiberFlex30D). Tests have shown that materials containing metallic reinforcement demonstrate higher mechanical resistance. Cut resistance increased by 70%, and the force needed to tear the sample increased by over 20% compared to the pure polymer. The presence of metallic reinforcement strengthens the structure of the material and changes the cracking mechanism. The tearing occurs in the test area, not in the bell area. These findings demonstrate the feasibility of applying functional 3D-printed polymeric materials with metal reinforcement in cut-resistant gloves.

Rendering Polyurethane Hydrophilic for Efficient Cellulose Reinforcement in Melt‐Spun Nanocomposite Fibers

AbstractMany commodity plastics, such as thermoplastic polyurethanes (PUs), require reinforcement for use as commercial products. Cellulose nanocrystals (CNCs) offer a “green” and scalable approach to polymer reinforcement as they are exceptionally stiff, recyclable, and abundant. Unfortunately, achieving efficient CNC reinforcement of PUs with industrial melt processing techniques is difficult, mostly due to the incompatibility of the hydrophobic PU with hydrophilic CNCs, limiting their dispersion. Here, a hydrophilic PU is synthesized to achieve strong reinforcement in melt‐processed nanocomposite fibers using filter paper‐sourced CNCs. The melt‐spun fibers, exhibiting smooth surfaces even at high CNC loading (up to 25 wt%) indicating good CNC dispersion, are bench‐marked against solvent‐cast films—solvent processing is not scalable but disperses CNCs well and produces strong CNC reinforcement. Mechanical analysis shows the CNC addition stiffens both nanocomposite films and fibers. The stress and strain at break, however, are not significantly affected in films, whereas adding CNCs to fibers increases the stress‐at‐break while reducing the strain‐at‐break. Compared to earlier studies employing a hydrophobic (and stiffer) PU, CNC addition to a hydrophilic PU substantially increases the fiber stiffness and strength. This work therefore suggests that rendering thermoplastics more hydrophilic might pave the way for “greener” polymer composite products using CNCs.

Experimental Study on Sisal Fiber Reinforced Concrete with Addition of Fly Ash

Abstract: Concrete is strong in compression but weak in tension. So we will provide the reinforcement to the concrete. Fiber Reinforced Concrete FRC can be used for a variety, of applications. Sisal is a natural fiber that is renewable, inexpensive, and readily accessible. SSF is a potential reinforcement for use in concrete because of its cheap cost, low density, high specific strength and modulus, negligible health risk, easy accessibility in certain states, and renewability. The manufacturing process of cement .emits considerable amount of carbon dioxide (CO2) . Therefore there is an urgent need to reduce the usage of cement. Fly ash is produced from the combustion of coal in electric utility or industrial boilers. The concrete in which the cement is replaced up to 40%. The study focuses on the compressive strength, split tensile strength, performance of the blended concrete containing Na2CO3 is treated with sisal fiber for 5 days on the strength parameters normal concrete had been carried out by varying percentages of 4%, 6%, 8%, 10% for M30 grade of concrete design by using IS10262-2009. Concrete cubes and cylinder are tested at the age of 7, 14, and 28 days of curing

Concrete Reinforced with Sisal Fibers (SSF): Overview of Mechanical and Physical Properties

Concrete is a commonly used building material; however, it is subject to abrupt failure and limited energy absorption when yielding. The use of short discrete fibers has displayed a lot of potential in overcoming these issues. Sisal is a natural fiber that is renewable, inexpensive, and readily accessible. SSF is a potential reinforcement for use in concrete because of its cheap cost, low density, high specific strength and modulus, negligible health risk, easy accessibility in certain states, and renewability. In current centuries, there has been growing importance in discovering new uses for SSF-reinforced concrete, which is normally utilized to make ropes, mats, carpets, and other decorative items. This article gives an overview of current advancements in SSF and composites. The qualities of SSF, the interface between SSF and the matrix, and SSF-reinforced properties such as fresh, mechanical strength, and durability have all been examined. The results show that SSF increased strength and durability while decreasing its flowability. The review also provides suggestions for further work.

Characterization and adhesive performance of phenol-formaldehyde resol resin reinforced with carbon nanotubes

Chemical, physical, thermal properties and bonding quality of phenol-formaldehyde resol resin (PF) synthesized with single-walled carbon nanotubes (SWCNTs) was evaluated at varying ratios from 1 wt% to 5 wt%. The effect of the SWCNTs addition on thermal and chemical properties of the PF resins was characterized by thermal gravimetric analysis (TGA) and Fourier transform infrared (FT-IR) spectroscopy, respectively. FT-IR analysis revealed that the peaks of the modified PF resol resins were similar to those of the reference (laboratory-produced) PF resol resin. These similarities indicated that the synthesis of the resins with phenol, formaldehyde, and carbon nano tubes was successful. The PF resins modified using SWCNTs demonstrated higher thermal stability than the reference PF resin. It was found that the bonding strength of the PF resin containing 3 wt% SWCNTs could reach 12.45 N/mm2 in dry conditions and 7.57 N/mm2 in wet conditions. The bonding test results demonstrated that the SWCNTs were able to improve the bonding performance of the resin under dry and/or wet conditions. This work presents an effective method to improve PF resins with SWCNTs reinforcement for use in the wood and/or polymer composite industries.

Perencanaan Ulang Struktur Atas Bangunan Kantor Dinas Pangan Provinsi Sumatera Barat

Upper structure is a building structure that is above the ground level such as columns, beams and floor plates. Each of thesecomponents has a different function in a structure. The reason for the appointment of this title is because the dimensions and useof reinforcement in this structure are inefficient and too wasteful. Therefore this title was appointed as a case study with the aim of planning the dimensions and structural reinforcement consisting of column elements, beams and floor plates in an efficient Padang city food office building and reviewing the structural design due to the use of reinforcement and dimensions too over or wasteful. . The method used in dimensioning and calculating reinforcement uses the SAP 2000 v14 method. With a design load that includes dead load, live load, and earthquake load in accordance with SNI 1727-2013 regarding the minimum load for planning buildings and other structures. Overall, the construction structure of this building is quite complex to discuss due to the additional roof load in the form of a helipad. From the results of this discussion, dimensions and structural reinforcement are more efficient and reduce construction costs, without reducing the quality and function theyshould be..

ТЕОРЕТИЧЕСКОЕ ОБОСНОВАНИЕ ПОВЫШЕНИЯ ЭФФЕКТИВНОСТИ АРМИРОВАНИЯ ИЗГИБАЕМЫХ ЯЧЕИСТОБЕТОННЫХ КОНСТРУКЦИЙ

Aerated concrete is actively used in energy efficient construction, mainly as a masonry material for vertical load-bearing structures. At the same time, the creation of a closed thermal contour of the building, which is the basis of modern energy saving requirements, is rational by the use of aerated concrete in load-bearing horizontal structures that require reinforcement. Traditionally bar reinforcement is ineffective in aerated concrete due to low specific adhesion at the contact of the reinforcement with concrete and significantly less than that of heavy concrete, the distribution capacity of concrete around a rod, which evenly transforms concrete stress to bar extension, the consequence of which is the significant bar understress while pulling it in concrete. The authors’ research in the field of rationalization of reinforcing elements that are effective in cellular concrete, aimed at increasing the contact surface of the reinforcing element with concrete while maintaining the original steel consumption, makes it possible to recommend tape reinforcement for use in reinforced aerated concrete structures. Punched steel tapes equal to the bar reinforcement of the cross-sectional area, but having developed lateral surface, provide an increase in the adhesion strength of the reinforcement and preventing its pulling. The article presents the results of a numerical study of stress-strain state in reinforced aerated concrete beam with rectangular section, reinforced with the proposed tape reinforcement in comparison with traditional bar reinforcement

Experimental and microstructural evaluation on mechanical properties of sisal fibre reinforced bio-composites

The natural fibre composites are termed as bio-composites. They have shown a promising replacement to the current carbon/glass fibre reinforced composites as environmental friendly materials in specific applications. Natural fibre reinforced composites are potential materials for various engineering applications in automobile, railways, building and Aerospace industry. The natural fibre selected to fabricate the composite material is plant-based fibre e.g., sisal fibre. Sisal fibre is a suitable reinforcement for use in composites on account of its low density, high specific strength, and high hardness. Epoxy is a thermosetting polymer which is used as a resin in natural fibre reinforced composites. Hand lay-up technique was used to fabricate the composites by reinforcing sisal fibres into the epoxy matrix. Composites were prepared with the unidirectional alignment of sisal fibres. Test specimens with different fibre orientations were prepared. The fabricated composites were tested for mechanical properties. Impact test, tensile test, flexural test, hardness test, compression test, and thermal test of composites had been conducted to assess its suitability in industrial applications. Scanning electron microscopy (SEM) test revealed the microstructural information of the fractured surface of composites.

An evidence-based intraoperative communication tool for emergency general surgery: a pilot study

BackgroundEmergency general surgery (EGS) is characterized by high rates of morbidity and mortality. Though checklists and associated communication-based huddle strategies have improved outcomes, these tools have never been specifically examined in EGS. We hypothesized that use of an evidence-based communication tool aimed to trigger intraoperative discussion could improve communication in the EGS operating room (OR). Materials and methodsWe designed a set of discussion prompts based on modifiable factors identified from previously published studies aimed to encourage all team members to speak up and to centralize awareness of patient disposition and intraoperative transfusion practices. This tool was pilot-tested using OR human patient simulators and was then rolled out to EGS ORs at an academic medical center. The perceived effect of our tool's implementation was evaluated through mixed-methodologic presurvey and postsurvey analysis. ResultsPreimplementation and postimplementation survey-based data revealed that providers reported the EGS-focused discussion prompts as improving team communication in EGS. A trend toward shared awareness of intraoperative events was observed; however, nurses described cultural impedance of discussion initiation. Providers described a need for further reinforcement of the tool and its indications during implementation. ConclusionsUse of a discussion-based communication tool is perceived as supporting team communication in the EGS OR and led to a trend toward improving a shared understanding of intraoperative events. Analyses suggest the need for enhanced reinforcement of use during implementation and improvement of team-based education regarding EGS. Furthermore work is needed to understand the full impact of this evidence-based tool on OR team dynamics and EGS patient outcomes.

An Experimental Study on Sisal/Hemp Fiber Reinforced Hybrid Composites

Environmental concerns motivate the use of cellulose fibers since bio-composites decompose easily in nature and low cost compare to synthetic fibers. Present paper investigates the mechanical properties and moisture absorption performance of different wt.% of sisal/hemp fiber incorporated epoxy resin hybrid composites. Sisal and hemp fiber surfaces were treated by 10% NaOH solution to enhance the bonding characteristic between fiber and epoxy resin. Hybrid composites were prepared by traditional cold pressing method. A 40 wt.% of sisal/hemp fiber reinforced hybrid composite discloses maximum flexural and compression strength. Absorption of water increases with fiber loading. Morphological analyses are carried out to analyze the fractured surface by using Scanning Electron Microscope and reported. The experimental result also discloses that the sisal and hemp fibers are promising reinforcement for use in low cost bio-composites which have high strength to weight ratio.

Comparative study of natural rubber and acrylonitrile rubber reinforced with aligned short aramid fiber

The aims of this paper are three-fold. The first is to determine the reinforcement of high performance short aramid fiber in two representative rubber matrices, namely natural rubber and acrylonitrile rubber. The second is to ascertain the effect of rubber polarity on the reinforcement. The third is to establish a pattern of reinforcement for use with less studied fibers. The rubbers were reinforced either with only aramid fiber or with a hybrid of aramid fiber and carbon black. The fiber contents were varied at 0, 2, 5 and 10 parts (by weight) per hundred rubber (phr) while those of carbon black were 0, 10, 20 and 30 phr. Conventional sulfur vulcanization was used. It was found that aramid fiber can reinforce both rubbers in the low strain region effectively, although to a significantly different degree. The hybrid carbon black provides additional reinforcement at low to medium strains and allows high strain stress upturn to occur in both rubber matrices. The findings enable the preparation of rubber composites having a wide, controllable range of mechanical behavior for specific high-performance engineering applications. Significantly, they also serve as a benchmark for developing reinforced systems from alternative fibers, particularly those from natural sources.

English

Jute fibre is anauspicious reinforcement for use in composites on account of its low cost, low density, high specific asset and modulus, no health risk, easy availability, renewability and much lower energy prerequisite for processing. In recent years, there has been an increasing interest in finding new applications for jute fiber reinforced composites that are conventionally used for making ropes, bags, hessians, sacking, mats, and carpet.To protect environment, consumptions of wood should be reduced that will increase number of tree in the world which can maintain the balance in nature. A major serving of woods are used for making home furniture, household products and erection and constructions. In all these cases wood can be replaced by composite materials made from natural fibers like jute, coir, sisal etc. Jutefibercombinations enjoy excellent probable as wood substitutes in view of their low cost, easy accessibility, saving in energy and pollution free production. In order to improve upon the laboratory-industry linkages towards application development & commercialization, some advanced composites mission launched on jute composites such as 'Jute-Coir Composites Boards', 'Jute-glass composite components for railway coaches' and others.The use of jute fiber mats in combination with polymer films theoretically offers a rapid and simple means of manufacturing combinations through film stacking, heating and press-consolidation.

Development of sandwich composites for building construction with locally available materials

A sandwich composite comprising ferrocement skins was developed as the primary structural module for building construction with indigenous materials. The indigenous reinforcement systems selected for use in ferrocement skins were jute burlap and chicken mesh (flexible galvanized steel wire). These reinforcement systems were characterized through performance of tension tests. The tensile strength, stiffness and ductility of jute burlaps were found to compare favorably with those of chicken mesh which is a viable reinforcement for use in ferrocement. Tension tests on ferrocement sheets indicated that indigenous reinforcement ratios above a threshold level could induce multiple cracking and strain-hardening behavior, producing a desired balance of tensile strength and ductility. The tensile strength of indigenous ferrocements with jute burlap reinforcement exceeded the theoretically predicted values, which could be attributed to the favorable interactions of the burlap reinforcement with the inorganic matrix, and the strengthening effects of hydrates precipitating within the yarn voids in burlap. Experiments were conducted to determine the bond strength and the required development length of the indigenous reinforcement in cementitious matrix. Indigenous sandwich composites comprising ferrocement skins with jute burlap reinforcement and an aerated concrete core made of lime-gypsum matrix and saponin foaming agent were fabricated and subjected to flexure testing. The sandwich composite provided relatively high flexural strengths; the flexural failure modes indicated that the relatively dense aerated concrete core makes important contributions to the flexural performance of the sandwich composite.

Mechanical Properties of Short Sisal Fibre Reinforced Phenol Formaldehyde Eco-Friendly Composites

Natural fibres are a good reinforcing material. Among the various natural fibres, sisal fibre is of particular interest, since its composites have high impact strength besides having moderate tensile and flexural properties compared to other ligno-cellulosic fibres. Sisal fibre is a promising reinforcement for use in composites on account of its low cost, low density, high specific strength and modulus, no health hazards, easy availability in some countries and renewability. The present work focused on the recent developments in the field of sisal fibre reinforced phenol formaldehyde composites with reference to the properties of sisal fibre, processing techniques, and the physical and mechanical properties of the composites. The mechanical properties of the composites show much improvement by the addition of sisal fibre of optimum fibre length 40 mm and fibre loading 54 wt%. The better fibre matrix interaction is shown by sisal-PF containing 54 wt%. The comparison with other natural fibres shows that sisal fibre is a good reinforcing agent in PF matrix. Flexural strength and impact strength of the composites were examined and are increased with increasing the fibre content. Ageing studies of the composites showed a similar trend to that of un-aged samples. Interestingly, water absorption test results show that composite with 54 wt% fibre loading have good interaction with the matrix and contains less voids.

A Review on Mechanical Behaviour of Bast-Glass Fibre Based Hybrid Polymer Composites

Natural fibres are gaining interest as reinforcement for polymer composite due to their environ mental and cost-effective benefits. Bast fibres is a prominent reinforcement for use in polymeric materials because of its low weight and cost, eco -friendly and abundant innature. Several authors manifest the advantageous usage of cellulosic bast fibres based polymeric materials in automobile industries and structural applications, but certain problems have been observed with the use of such fibres such as high water-uptake tendency and low mechanical strength than the inorganic fibres. The adverse properties of such bast fibres based composites can be overcome by hybridization with synthetic fibres. In the present article, we have reviewed the effect of hybridization of glass fibres on mechanical properties of bast fibre (jute, hemp, kenaf, flax) based hybrid polymer composites.

Acute cocaine exposure elicits rises in calcium in arousal-related laterodorsal tegmental neurons.

Cocaine has strong reinforcing properties, which underlie its high addiction potential. Reinforcement of use of addictive drugs is associated with rises in dopamine (DA) in mesoaccumbal circuitry. Excitatory afferent input to mesoaccumbal circuitry sources from the laterodorsal tegmental nucleus (LDT). Chronic, systemic cocaine exposure has been shown to have cellular effects on LDT cells, but acute actions of local application have never been demonstrated. Using calcium imaging, we show that acute application of cocaine to mouse brain slices induces calcium spiking in cells of the LDT. Spiking was attenuated by tetrodotoxin (TTX) and low calcium solutions, and abolished by prior exhaustion of intracellular calcium stores. Further, DA receptor antagonists reduced these transients, whereas DA induced rises with similar spiking kinetics. Amphetamine, which also results in elevated levels of synaptic DA, but via a different pharmacological action than cocaine, induced calcium spiking with similar profiles. Although large differences in spiking were not noted in an animal model associated with a heightened proclivity of acquiring addiction‐related behavior, the prenatal nicotine exposed mouse (PNE), subtle differences in cocaine's effect on calcium spiking were noted, indicative of a reduction in action of cocaine in the LDT associated with exposure to nicotine during gestation. When taken together, our data indicate that acute actions of cocaine do include effects on LDT cells. Considering the role of intracellular calcium in cellular excitability, and of the LDT in addiction circuitry, our data suggest that cocaine effects in this nucleus may contribute to the high addiction potential of this drug.

Mechanical Properties of Sisal/Coir Fiber Reinforced Hybrid Composites Fabricated by Cold Pressing Method

Bio-composites have less density and are environmental friendly materials that require less energy during production and subsequent machining. This paper reports the mechanical and water absorption properties of sodium hydroxide (NaOH) treated sisal and coir fiber reinforced epoxy resin thermo set hybrid composites. The hybrid composites were prepared by traditional cold pressing method at room temperature with applied pressure of 410.4 kg/cm2 for 3 hours pressurization time. The mechanical properties were characterized according to ASTM standards. Hybrid composites with 40wt% of sisal and coir fiber were found to possess higher tensile strength of 48.2MPa and flexural strength of 76.68 MPa among the fabricated hybrid composite specimens. Absorption of water increases with increasing fiber volume. The experimental result also show that the sisal and coir fibers are promising reinforcement for use in low cost bio-composites which have high strength to weight ratio.

Influence of the process parameters on the mechanical properties of engineering biocomposites using a twin-screw extruder

The utilization of bio-based engineering polymers as a matrix material for cellulosic fiber reinforced composites has become an important focus in materials research. This is due to a rising demand for sustainable materials from renewable resources. In addition to this aspect, the bio-based materials provide an advantage for lightweight applications with their lower density. In this investigation, the completely bio-based polyamide 10.10, with a melting point above 200°C, was used as a polymer matrix. Chopped man-made cellulose fibers (Cordenka CR-Type) were investigated as reinforcement for use in injection molded applications. A co-rotating twin-screw extruder with a screw-diameter of 18mm was used for compounding. It was verified that reinforcing polyamide 10.10 with 20wt% and 30wt% cellulosic fibers is possible, resulting in an increase of impact and tensile properties. Furthermore, it was shown that the temperatures and screw-configurations of the twin-screw extruder only result in different fiber length distributions but in minor differences of the morphological structure and mechanical properties of PA 10.10 with 20wt% fibers. Compounds with 30wt% cellulose fibers show significant higher impact properties that those with 30wt% glass fibers.

Jute Composites as Wood Substitute

Jute fibre is a p ro mising reinforcement for use in co mposites on account of its low cost, low density, high specific strength and modulus, no health risk, easy availability, renewability and much lower energy requirement for processing. In recent years, there has been an increasing interest in finding new applications for jute fibre reinforced composites that are traditionally used for making ropes, bags, hessians, sacking, mats, and carpet.To protect environment, consumptions of wood should be reduced that will increase number of tree in the world which can maintain the balance in nature. A major portion of woods are used for making home furniture, household products and building and constructions. In all these cases wood can be replaced by co mposite materials made fro m natural fibres like jute, coir, sisal etc.Jute fibre composites enjoy excellent potential as wood substitutes in view of their lo w cost, easy availability, saving in energy and pollution free p roduction. In order to improve upon the laboratory-industry linkages towards applicat ion development & commercialization, some advanced composites mission launched on jute composites such as 'Jute-Coir Co mposites Boards', 'Jute-glass composite components for railway coaches' and others.The use of jute fiber mats in co mbination with polymer films potentially offers a rapid and simp le means of manufacturing co mposites through film stacking, heating and press-consolidation.

EVALUATING PREFERENCE ASSESSMENTS FOR USE IN THE GENERAL EDUCATION POPULATION

This study compared the effectiveness of a multiple-stimulus-without-replacement (MSWO) preference assessment and teacher preference ranking in identifying reinforcers for use in a general education setting with typically developing elementary-school children. The mean number of digits correctly answered was greater in the MSWO-selected reward and the teacher-selected reward conditions relative to the no-reward condition for 2 of the 4 participants, but there were no differences between the MSWO-selected and teacher-selected reward conditions for any participant.