scholarly journals Smart Graphite–Cement Composite for Roadway-Integrated Weigh-In-Motion Sensing

Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4518
Author(s):  
Hasan Borke Birgin ◽  
Antonella D’Alessandro ◽  
Simon Laflamme ◽  
Filippo Ubertini
Keyword(s):  
Low Cost ◽  
Physical And Mechanical Properties ◽  
Cement Composite ◽  
Graphite Powder ◽  
Cement Matrix ◽  
Vehicle Speed ◽  
Strain Sensing ◽  
Signal Processing Algorithm ◽  
Weigh In Motion ◽  
Signal Sensitivity

Smart multifunctional composites exhibit enhanced physical and mechanical properties and can provide structures with new capabilities. The authors have recently initiated a research program aimed at developing new strain-sensing pavement materials enabling roadway-integrated weigh-in motion (WIM) sensing. The goal is to achieve an accurate WIM for infrastructure monitoring at lower costs and with enhanced durability compared to off-the-shelf solutions. Previous work was devoted to formulating a signal processing algorithm for estimating the axle number and weights, along with the vehicle speed based on the outputs of a piezoresistive pavement material deployed within a bridge deck. This work proposes and characterizes a suitable low-cost and highly scalable cement-based composite with strain-sensing capabilities and sufficient sensitivity to meet WIM signal requirements. Graphite cement-based smart composites are presented, and their electromechanical properties are investigated in view of their application to WIM. These composites are engineered for scalability owing to the ease of dispersion of the graphite powder in the cement matrix, and can thus be used to build smart sections of road pavements. The research presented in this paper consists of electromechanical tests performed on samples of different amounts of graphite for the identification of the optimal mix in terms of signal sensitivity. An optimum inclusion level of 20% by weight of cement is obtained and selected for the fabrication of a plate of 30 × 15 × 5 cm3. Results from load identification tests conducted on the plate show that the proposed technology is capable of WIM.

scholarly journals A potentiometric sensor for determination of hydrochinone

2021 ◽  
pp. 66-73
Author(s):  
Galyna Petrushyna ◽  
Yuliya Boyko ◽  
Andrey Vishnikin ◽  
Yaroslav Bazel ◽  
Olga Chygvintseva
Keyword(s):  
Electrical Conductivity ◽  
Composite Material ◽  
Low Cost ◽  
Inorganic Ions ◽  
Physical And Mechanical Properties ◽  
Graphite Powder ◽  
Reducing Agents ◽  
Polymer Composite Material ◽  
Neutral Medium ◽  
Electrochemical Characteristics

Hydroquinone has a high toxicity and therefore its content must be carefully monitored. The development of new easy-to-manufacture electrodes with the best analytical characteristics, which have a low cost of analysis, is an urgent task. An electrode based on graphite and a composite material consisting of polyurethane (as polymer matrix), graphite powder (to increase the electrical conductivity of the material) and 18-molybdodiphosphate (as a reagent) for hydroquinone determination was proposed. The advantages of polyurethanes for the electrodes modification include high adhesion of the polymer to the electrode surface due to the presence of a large number of polar groups. In addition, its specific properties provide high physical and mechanical properties of the polymer. The molybdenum heteropoly anion of the Wales-Dawson type 18-molybdodiphosphate anion P2Mo18O626- is a strong enough oxidant. The reaction between it and the some reducing agents is almost instantaneous, the recovery proceeds without destruction of P2Mo18O626-, which allows its repeated use. Interaction of P2Mo18O626- with different reducing agents occurs at different acidity of solutions. Thus, varying the pH of the solution allows determining of several substances in a compatible presence. Fine graphite powder in quantity from 50% to 70% was added in composite material to increase the electrical conductivity. P2Mo18O626- was added in an amount of 20% to the total weight of the composite material. The graphite electrode was modified with the synthesized polymer composite material. The main electrochemical characteristics of the proposed electrode are determined. Reduction of P2Mo18O626- with hydroquinone is proceeds in a neutral medium (pH 6). The response time at different concentrations of the hydroquinone is 8 min (at a temperature of 19 °C). This electrode does not have a "memory effect", the relative error is from 1.3 to 1.9%, and the potential deviation is in the range of 3-5 mV. The limit of determination is 2∙10-5 mol/l. The effect of the present substances was evaluated using a constant of selectivity. The proposed electrode has a high selectivity for a large number of inorganic ions. The electrode must be soaked in a solution of 3% hydrogen peroxide for 10 minutes to regeneration.

scholarly journals Modification of the Structure and Properties of Lightweight Cement Composite with PVA Fibers

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5983
Author(s):  
Donatas Sikarskas ◽  
Valentin Antonovič ◽  
Jurgita Malaiškienė ◽  
Renata Boris ◽  
Rimvydas Stonys ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Blended Cement ◽  
Physical And Mechanical Properties ◽  
Type A ◽  
Cement Composite ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Cement Matrix ◽  
Pva Fiber

This study addresses the application of polyvinyl alcohol (PVA) fibers to improve the performance of lightweight cement composites with pozzolans. Blended cement mixes based on expanded glass granules were modified with PVA fibers (Type A: Ø40 µm, L = 8 mm and Type B: Ø200 µm, L = 12 mm). The following research methods were used to analyse the effect of the fibers on the structure of cement matrix and physical-mechanical properties of lightweight composite: SEM, XRD, DTG, calorimetry tests, and standard test methods of physical and mechanical properties. Results from the tests showed that a denser layer of hydrates was formed around the PVA fiber and the amounts of portlandite, CSH, and CASH formed in the specimens with PVA were found to be higher. PVA fibers of Type A accelerated hydration of the cement paste, slightly increased the compressive strength of the lightweight composite, but had no significant effect on the values of density, ultrasonic pulse velocity and flexural strength. The shrinkage of cement composite was significantly reduced using both types of PVA fiber and both types of PVA fibers increased the fracture energy of lightweight cement composite with expanded granules.

Surface Modification of Poly(Vinylchloride) for Manufacturing Advanced Catheters

2020 ◽  
Vol 27 (10) ◽  
pp. 1616-1633 ◽  
Author(s):  
Oana Cristina Duta ◽  
Aurel Mihail Ţîţu ◽  
Alexandru Marin ◽  
Anton Ficai ◽  
Denisa Ficai ◽  
...  
Keyword(s):  
Surface Modification ◽  
Chemical Modification ◽  
Medical Devices ◽  
Low Cost ◽  
Physical And Mechanical Properties ◽  
Polymeric Materials ◽  
Modern Medicine ◽  
Structural Failure ◽  
Chemical Grafting ◽  
One Step

Polymeric materials, due to their excellent physicochemical properties and versatility found applicability in multiples areas, including biomaterials used in tissue regeneration, prosthetics (hip, artificial valves), medical devices, controlled drug delivery systems, etc. Medical devices and their applications are very important in modern medicine and the need to develop new materials with improved properties or to improve the existent materials is increasing every day. Numerous reasearches are activated in this domain in order to obtain materials/surfaces that does not have drawbacks such as structural failure, calcifications, infections or thrombosis. One of the most used material is poly(vinylchloride) (PVC) due to its unique properties, availability and low cost. The most common method used for obtaining tubular devices that meet the requirements of medical use is the surface modification of polymers without changing their physical and mechanical properties, in bulk. PVC is a hydrophobic polymer and therefore many research studies were conducted in order to increase the hydrophilicity of the surface by chemical modification in order to improve biocompatibility, to enhance wettability, reduce friction or to make lubricious or antimicrobial coatings. Surface modification of PVC can be achieved by several strategies, in only one step or, in some cases, in two or more steps by applying several techniques consecutively to obtain the desired modification / performances. The most common processes used for modifying the surface of PVC devices are: plasma treatment, corona discharge, chemical grafting, electric discharge, vapour deposition of metals, flame treatment, direct chemical modification (oxidation, hydrolysis, etc.) or even some physical modification of the roughness of the surface.

scholarly journals Physical and Mechanical Properties of Natural Leaf Fiber-Reinforced Epoxy Polyester Composites

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1369
Author(s):  
Sanjeev Kumar ◽  
Lalta Prasad ◽  
Vinay Kumar Patel ◽  
Virendra Kumar ◽  
Anil Kumar ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Synthetic Fibre ◽  
Low Cost ◽  
Fibre Length ◽  
Physical And Mechanical Properties ◽  
Natural Fibres ◽  
Risk Environment ◽  
Insulation Property ◽  
Natural Leaf

In recent times, demand for light weight and high strength materials fabricated from natural fibres has increased tremendously. The use of natural fibres has rapidly increased due to their high availability, low density, and renewable capability over synthetic fibre. Natural leaf fibres are easy to extract from the plant (retting process is easy), which offers high stiffness, less energy consumption, less health risk, environment friendly, and better insulation property than the synthetic fibre-based composite. Natural leaf fibre composites have low machining wear with low cost and excellent performance in engineering applications, and hence established as superior reinforcing materials compared to other plant fibres. In this review, the physical and mechanical properties of different natural leaf fibre-based composites are addressed. The influences of fibre loading and fibre length on mechanical properties are discussed for different matrices-based composite materials. The surface modifications of natural fibre also play a crucial role in improving physical and mechanical properties regarding composite materials due to improved fibre/matrix adhesion. Additionally, the present review also deals with the effect of silane-treated leaf fibre-reinforced thermoset composite, which play an important role in enhancing the mechanical and physical properties of the composites.

scholarly journals Features of the hydration process of the modified blended cement for fiber cement panels

2018 ◽  
Vol 170 ◽  
pp. 03030 ◽  
Author(s):  
Rustem Mukhametrakhimov ◽  
Liliya Lukmanova
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Blended Cement ◽  
Physical And Mechanical Properties ◽  
Hydration Process ◽  
Cement Matrix ◽  
X Ray Diffraction ◽  
Structure Form ◽  
Silicate Phase ◽  
X Ray

The paper studies features of the hydration process of the modified blended cement for fiber cement panels (FCP) using differential thermal analysis, X-ray diffraction analysis, electron microscopy and infrared spectroscopy. It is found that deeper hydration process in silicate phase, denser and finer crystalline structure form in fiber cement matrix based on the modified blended cement. Generalization of this result to the case of fiber cement panels makes it possible to achieve formation of a denser and homogeneous structure with increased physical and mechanical properties.

scholarly journals A Novel Longitudinal Speed Estimator for Four-Wheel Slip in Snowy Conditions

2021 ◽  
Vol 11 (6) ◽  
pp. 2809
Author(s):  
Dongmin Zhang ◽  
Qiang Song ◽  
Guanfeng Wang ◽  
Chonghao Liu
Keyword(s):  
Control Strategies ◽  
Low Cost ◽  
Estimation Error ◽  
Slip Rate ◽  
Vehicle Speed ◽  
Acceleration Sensor ◽  
Wheel Slip ◽  
Longitudinal Acceleration ◽  
Tire Rotation ◽  
Speed Estimator

This article proposes a novel longitudinal vehicle speed estimator for snowy roads in extreme conditions (four-wheel slip) based on low-cost wheel speed encoders and a longitudinal acceleration sensor. The tire rotation factor, η, is introduced to reduce the deviation between the rotation tire radius and the manufacturer’s marked tire radius. The Local Vehicle Speed Estimator is defined to eliminate longitudinal vehicle speed estimation error. It improves the tire slip accuracy of four-wheel slip, even with a high slip rate. The final vehicle speed is estimated using two fuzzy control strategies that use vehicle speed estimates from speed encoders and a longitudinal acceleration sensor. Experimental and simulation results confirm the algorithm’s validity for estimating longitudinal vehicle speed for four-wheel slip in snowy road conditions.

scholarly journals Phenol Novalac Epoxy-modified unsaturated polyester hybrid networks by Silica Nanoparticles/ and Cross linking with Silane Compounds

2020 ◽  
Vol 1 (2) ◽  
pp. 28-32
Keyword(s):  
Epoxy Resin ◽  
Silica Nanoparticles ◽  
Elevated Temperatures ◽  
Unsaturated Polyester ◽  
Low Cost ◽  
Physical And Mechanical Properties ◽  
Hybrid Networks ◽  
Azo Compounds ◽  
Cross Linking ◽  
Chemical Attributes

In this study epoxy phenol novalac resin which consists of silica nanoparticles and unsaturated poly ester resin linked to the Silane and cross linking to that structure and also parameters affecting the processes involved have been evaluated. Cross linking in phenol novalac epoxy resins effects on many properties such as thermal, electrical, mechanical and chemical attributes especially in elevated temperatures. Silane cross-linking’s in phenol novalac epoxy resin with respect to other methods like proxiding, irradiation and utilization of Azo compounds, looks to be a very simple and low cost route, which makes it very encouraging for various industries. Unsaturated poly ester resin is compatible with phenol novalac epoxy resin and also creates some cross-linking and as far as tri methoxy Silane is added to the mentioned resin, its thermal, physical and mechanical properties are optimized. In this literature impact, tension, glass transition temperature, humidity absorption, FTIR and Scanning electron microscopy (SEM) tests were done and the results revealed that as the cross-linking occurs, tension in rupture region increases. This increase is more common at elevated temperatures. The growth in content of silica nanoparticles leads to a drop in water permeability of phenol novalac epoxy resin nanocomposite which contains unsaturated poly ester resin.

scholarly journals Influence of nanocellulose on the hydration process of Portland cement and concrete properties

2020 ◽  
Vol 17 (5) ◽  
pp. 155-160
Author(s):  
V. I. Khirkhasova ◽  
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Physical And Mechanical Properties ◽  
Cement Composite ◽  
High Density ◽  
Strength Characteristics ◽  
New Method ◽  
Concrete Properties ◽  
Hardening Process ◽  
Study Results

The paper deals with modification of cement composite and concrete with nanocellulose in low and high density. The author presents the study results of the influence of nanocellulose on the cement composite hardening process, as well as the physical and mechanical properties of heavy concrete. The influence of the used additive on the rheological and strength characteristics of concrete is revealed. A new method is proposed to improve the material performance.

scholarly journals Implementation of machine learning techniques to control the speed of the vehicles

2018 ◽  
Vol 7 (4.5) ◽  
pp. 654
Author(s):  
M. S. Satyanarayana ◽  
Aruna T.M ◽  
Divyaraj G.N
Keyword(s):  
Machine Learning ◽  
Low Cost ◽  
Machine Learning Techniques ◽  
New Technique ◽  
Vehicle Speed ◽  
Learning Techniques ◽  
Traffic Awareness ◽  
Alarm Sound ◽  
The Government ◽  
A New Technique

Accidents have become major issue in Developing countries like India now a day. As per the Surveys 60% of the accidents are happening due to over speed. Though the government has taken so many initiatives like Traffic Awareness & Driving Awareness Week etc.., but still the percentage of accidents are not getting reduced. In this paper a new technique has been introduced to reduce the percentage of accidents. The new technique is implemented using the concept of Machine Learning [1]. The Machine Learning based systems can be implemented in all vehicles to avoid the accidents at low cost [1]. The main objective of this system is to calculate the speed of the vehicle at three various locations based on the place where the vehicle speed must be controlled and if the speed is greater than the designated speed in that road then the vehicle automatically detects the problem and same will be intimated to the driver to control the speed of the vehicle. If the speed is less or equal to the designated speed in that road then the vehicle will be passed without any disturbance. The system will be giving beep sound along with color indication to driver in each and every scenario. The other option implemented in this system is if the driver is driving the vehicle in the night and if he feel drowsy the system detects it immediately and alarm sound will be initiated to wake up the driver. This system though it won’t avoid 100% accidents at least it will reduce the percentage of accidents. This system is not only to avoid accidents it will also intelligently control the speed of the vehicles and creates awareness amongst the drivers.  

scholarly journals Global analysis of DEF damage to concretes with and without fly-ash

2022 ◽  
Vol 15 (3) ◽  
Author(s):  
Nicole Pagan Hasparyk ◽  
Dioice Schovanz ◽  
Francieli Tiecher ◽  
Selmo Chapira Kuperman
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Global Analysis ◽  
Physical And Mechanical Properties ◽  
Test Method ◽  
Cement Matrix ◽  
Negative Effects ◽  
Ettringite Formation ◽  
Pozzolanic Cement ◽  
Over Time

Abstract Delayed Ettringite formation (DEF) is an internal expansive reaction that can damage concrete. DEF is strongly influenced by the temperature, above about 60-65°C, and other factors involving cement chemistry especially, but also its physical characteristics. The exposure environment over time also promotes a condition to increase deterioration from DEF. Expansions results from secondary ettringite formation are progressive and can lead concrete to microcracking impacting its performance and durability over time. Several concrete structures are pointed to be severely attacked by DEF, and test method as well a better comprehension on this pathology is necessary to promote specific and proper preventive measures to avoid future damages. Furthermore, compared to alkali-silica reaction, DEF occurs more readily and aggressively, and sometimes prematurely, depending on several factors, such as type of cement, concrete mix design, exposure conditions, among others. This paper involves an overall analysis of the behavior of concretes with two types of Portland cements (High early-strength cement and a Portland pozzolanic cement, with fly-ash) in relation to DEF process. Several data from a laboratory study where DEF was induced through a specific thermal curing procedure are presented and discussed. The analyses involved the assessment of physical, mechanical, and expansive properties besides microstructural monitoring of samples from concretes over time. These experiments allowed detecting high values of expansions from DEF (up to 1.2%) in the concrete without fly ash. The mechanical properties were severely impacted from this deleterious process; as expansions increased, losses in the mechanic and elastic properties were verified. Expansion levels in the order of 0.5% prompted remarkably high reductions and, at about 1% the losses were relevant for both strengths (tensile and compressive) and modulus of elasticity, of 60% and 80%, respectively, in the presence of cement without fly-ash. Concrete microstructure has indicated massive formations of ettringite as well as micro-cracking and the fragility of the cement matrix because of DEF. On the other hand, expansion up to 0.2% did not promote important negative effects on the properties of concrete, especially with the pozzolanic cement tested. Furthermore, an overall approach with several correlations between physical and mechanical properties was taken to obtain different levels of deterioration for a concrete presenting DEF.

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