Search results for: Contact ratio

Authors: Yang Weiping, Zhang Zhilong, Zhang Yan, Chen Zengping

Abstract:

Infrared focal plane arrays (IRFPA) sensors, due to their high sensitivity, high frame frequency and simple structure, have become the most prominently used detectors in military applications. However, they suffer from a common problem called the fixed pattern noise (FPN), which severely degrades image quality and limits the infrared imaging applications. Therefore, it is necessary to perform non-uniformity correction (NUC) on IR image. The algorithms of non-uniformity correction are classified into two main categories, the calibration-based and scene-based algorithms. There exist some shortcomings in both algorithms, hence a novel non-uniformity correction algorithm based on non-linear fit is proposed, which combines the advantages of the two algorithms. Experimental results show that the proposed algorithm acquires a good effect of NUC with a lower non-uniformity ratio.

Keywords: Non-uniformity correction, non-linear fit, two-point correction, temporal Kalman filter.

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Authors: Salman Pervaiz, Ibrahim Deiab, Amir Rashid, Mihai Nicolescu, Hossam Kishawy

Abstract:

Greenhouse gases (GHG) emissions impose major threat to global warming potential (GWP). Unfortunately manufacturing sector is one of the major sources that contribute towards the rapid increase in greenhouse gases (GHG) emissions. In manufacturing sector electric power consumption is the major driver that influences CO2 emission. Titanium alloys are widely utilized in aerospace, automotive and petrochemical sectors because of their high strength to weight ratio and corrosion resistance. Titanium alloys are termed as difficult to cut materials because of their poor machinability rating. The present study analyzes energy consumption during cutting with reference to material removal rate (MRR). Surface roughness was also measured in order to optimize energy consumption.

Keywords: Energy Consumption, CO2 Emission, Ti6Al4V.

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Authors: Robert S. Giachetti, Emanuele Grossi

Abstract:

Loosening of bolted joints in rotating machines can adversely affect their performance, cause mechanical damage, and lead to injuries. In this paper, two potential loosening phenomena in rotating applications are discussed. First, ‘precession,’ is governed by thread/nut contact forces, while the second is based on inertial effects of the fastened assembly. These mechanisms are reviewed within the context of historical usage of left-handed fasteners in rotating machines which appears absent in the literature and common machine design texts. Historically, to prevent loosening of wheel nuts, vehicle manufacturers have used right-handed and left-handed threads on different sides of the vehicle, but most modern vehicles have abandoned this custom and only use right-handed, tapered lug nuts on all sides of the vehicle. Other classical machines such as the bicycle continue to use different handed threads on each side while other machines such as, bench grinders, circular saws and brush cutters still use left-handed threads to fasten rotating components. Despite the continued use of left-handed fasteners, the rationale and analysis of left-handed threads to mitigate self-loosening of fasteners in rotating applications is not commonly, if at all, discussed in the literature or design textbooks. Without scientific literature to support these design selections, these implementations may be the result of experimental findings or aged institutional knowledge. Based on a review of rotating applications, historical documents and mechanical design references, a formal study of the paradoxical nature of left-handed threads in various applications is merited.

Keywords: Rotating machinery, self-loosening fasteners, wheel fastening, vibration loosening.

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Authors: Hamid A. Jalab, Rabha W. Ibrahim

Abstract:

This paper introduces an image denoising algorithm based on generalized Srivastava-Owa fractional differential operator for removing Gaussian noise in digital images. The structures of nxn fractional masks are constructed by this algorithm. Experiments show that, the capability of the denoising algorithm by fractional differential-based approach appears efficient to smooth the Gaussian noisy images for different noisy levels. The denoising performance is measured by using peak signal to noise ratio (PSNR) for the denoising images. The results showed an improved performance (higher PSNR values) when compared with standard Gaussian smoothing filter.

Keywords: Fractional calculus, fractional differential operator, fractional mask, fractional filter.

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Authors: F. Garousi, Sz. Veres, É. Bódi, Sz. Várallyay, B. Kovács

Abstract:

Specific leaf area (SLA; cm2leaf g-1leaf) the ratio of leaf area to leaf dry mass is a key ecophysiological parameter influencing leaf physiology, photosynthesis, and whole plant carbon gain and also can be used as a rapid and diagnostic tool. In this study, two species of soluble inorganic selenium forms, selenite (Se^IV) and selenate (Se^VI) at different concentrations were investigated on maize plants that were growing in nutrient solutions during 2 weeks and at the end of the experiment, amounts of SLA for first and second leaves of maize were measured. In accordance with the results we observed that our regarded Se concentrations in both forms of Se^IV and Se^VI were not effective on maize plants’ SLA significantly although high level of 3 mg.kg-1 Se^IV had negative affect on growth of the samples that had been treated by it but about Se^VI samples we did not observe this state and our different considered Se^VI concentrations were not toxic for maize plants.

Keywords: Maize, Sodium selenate, sodium selenite, specific leaf area.

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Authors: Altayeb Qasem, Tarek Zayed, Zhi Chen

Abstract:

Statistics Canada stated that the wastewater treatment facilities in most provinces are aging and passes 63% of their useful life in 2007 the highest ratio among public infrastructure assets. Currently, there is no standard condition rating system for wastewater treatment plants that give a specific rating index that describe the physical integrity of different infrastructure elements in the treatment plant and its environmental performance. The main objective of this study is to develop a condition-rating index for wastewater treatment plants mainly activated sludge systems. The proposed WWTP CRI, is based on dividing the treatment plant into its three treatment phases; primary phase, secondary phase and the tertiary phase. The condition-rating index will reflect the infrastructures state for each phase, mainly tanks, pipes, blowers and pumps.

Keywords: Condition rating index, Wastewater treatment plants, AHP- MUAT.

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Authors: D. Zare, F. Salmanizade, H. Safiyari

Abstract:

Physical and mechanical properties of Russian olive fruits were measured at moisture content of 14.43% w.b. The results revealed that the mean length, width and thickness of Russian olive fruits were 20.72, 15.73 and 14.69mm, respectively. Mean mass and volume of Russian olive fruits were measured as 1.45 g and 2.55 cm3, respectively. The sphericity, aspect ratio and surface area were calculated as 0.81, 0.72 and 8.96 cm2, respectively, while arithmetic mean diameter, geometric mean diameter and equivalent diameter of Russian olive fruits were 17.05, 16.83 and 16.84 mm, respectively. Whole fruit density, bulk density and porosity of jujube fruits were measured and found to be 1.01 g/cm3, 0.29 g/cm3 and 69.5%, respectively. The values of static coefficient of friction on three surfaces of glass, galvanized iron and plywood were 0.35, 0.36 and 0.43, respectively. The skin color (L*, a*, b*) varied from 9.92 to 16.08; 2.04 to 3.91 and 1.12 to 3.83, respectively. The values of rupture force, deformation, energy absorbed and hardness were found to be between 12.14-16.85 N, 2.16-4.25 mm, 3.42-6.99 N mm and 17.1-23.85 N/mm.

Keywords: Mechanical and Physical properties, Russian olive fruits, friction coefficient

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Authors: Joonsup Han, Jaehyeon Lee, Hyungmin Kim, Kihyung Lee

Abstract:

PCCI engines can reduce NOx and PM emissions simultaneously without sacrificing thermal efficiency, but a low combustion temperature resulting from early fuel injection, and ignition occurring prior to TDC, can cause higher THC and CO emissions and fuel consumption. In conclusion, it was found that the PCCI combustion achieved by the 2-stage injection strategy with optimized calibration factors (e.g. EGR rate, injection pressure, swirl ratio, intake pressure, injection timing) can reduce NOx and PM emissions simultaneously. This research works are expected to provide valuable information conducive to a development of an innovative combustion engine that can fulfill upcoming stringent emission standards.

Keywords: Atkinson cycle, Diesel Engine, LIVC (Late intakevalve closing), PCCI (premixed charge compression ignition)

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Authors: Lorenzo Daghini, Andreas Archenti, Cornel Mihai Nicolescu

Abstract:

This paper introduces a novel design for boring bar with enhanced damping capability. The principle followed in the design phase was to enhance the damping capability minimizing the loss in static stiffness through implementation of composite material interfaces. The newly designed tool has been compared to a conventional tool. The evaluation criteria were the dynamic characteristics, frequency and damping ratio, of the machining system, as well as the surface roughness of the machined workpieces. The use of composite material in the design of damped tool has been demonstrated effective. Furthermore, the autoregressive moving average (ARMA) models presented in this paper take into consideration the interaction between the elastic structure of the machine tool and the cutting process and can therefore be used to characterize the machining system in operational conditions.

Keywords: ARMA, cutting stability, damped tool, machining.

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Authors: Joon Ho Kim, Tae Kwon Ha

Abstract:

Effect of aging treatment on microstructural aspects of interfacial layers of the Cu/Al clad sheet produced by differential speed rolling (DSR) process were studied by electron back scattered diffraction (EBSD). Clad sheet of Al/Cu has been fabricated by using DSR, which caused severe shear deformation between Al and Cu plate to easily bond to each other. Rolling was carried out at 100^oC with speed ratio of 2, in which the total thickness reduction was 45%. Interface layers of clad sheet were analyzed by EBSD after subsequent annealing at 400^oC for 30 to 120min. With increasing annealing time, thickness of interface layer and fraction of high angle grain boundary were increased and average grain size was decreased.

Keywords: Aluminum/Copper clad sheet, differential speed rolling, interface layer, microstructure, annealing, electron back scattered diffraction.

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Authors: Abhijit Mitra, Pranab Kumar Banerjee, C. Ardil

Abstract:

We introduce an effective approach for automatic offline au- thentication of handwritten samples where the forgeries are skillfully done, i.e., the true and forgery sample appearances are almost alike. Subtle details of temporal information used in online verification are not available offline and are also hard to recover robustly. Thus the spatial dynamic information like the pen-tip pressure characteristics are considered, emphasizing on the extraction of low density pixels. The points result from the ballistic rhythm of a genuine signature which a forgery, however skillful that may be, always lacks. Ten effective features, including these low density points and den- sity ratio, are proposed to make the distinction between a true and a forgery sample. An adaptive decision criteria is also derived for better verification judgements.

Keywords: Handwritten document verification, Skilled forgeries, Low density pixels, Adaptive decision boundary.

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Authors: Ashraf M. Elsaid, Magd M. Badr, Mohamed S. Selim

Abstract:

Water borne polyurethane (PU) based on newly prepared hyperbranched poly (amine-ester) (HBPAE) was applied and evaluated as organic coating material. HBPAE was prepared through one-pot synthesis between trimethylol propane as a core and AB2 branched monomer which was obtained via Michal addition of methyl methacrylate (MMA) and diethanol amine (DEA). PU was prepared from HBPAE using different ratios of toluene diisocyanate (TDI) to form cured coating film. The prepared HBPAE was characterized using; GPC, FT-IR and 1H-NMR. The mechanical properties (impact, hardness, adhesion, and flexibility), thermal properties (DSC and TGA) and chemical resistance of the applied film were estimated. The results indicated 50% of TDI is the selected ratio. This formulation represents a promising candidate to be used as coating material.

Keywords: Curing, Hyperbranched polymer, Polyurethane, Urethane-acrylates, water borne Coatings.

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Authors: Joumana Farah, François Marx, Clovis Francis

Abstract:

The aim of this paper is to emphasize and alleviate the effect of phase noise due to imperfect local oscillators on the performances of a Multi-Carrier CDMA system. After the cancellation of Common Phase Error (CPE), an iterative approach is introduced which iteratively estimates Inter-Carrier Interference (ICI) components in the frequency domain and cancels their contribution in the time domain. Simulation are conducted in order to investigate the achievable performances for several parameters, such as the spreading factor, the modulation order, the phase noise power and the transmission Signal-to-Noise Ratio.

Keywords: Inter-carrier Interference, Multi-Carrier Code DivisionMultiple Access, Orthogonal Frequency Division Multiplexing, Phase noise.

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Authors: Majid Riahi Samani, Seyed Mehdi Borghei

Abstract:

Absorptive characteristics of polyaniline synthesized in mixture of water and acetonitrile in 50/50 volume ratio was studied. Synthesized polyaniline in powder shape is used as an adsorbent to remove toxic hexavalent chromium from aqueous solutions. Experiments were conducted in batch mode with different variables such as agitation time, solution pH and initial concentration of hexavalent chromium. Removal mechanism is the combination of surface adsorption and reduction. The equilibrium time for removal of Cr(T) and Cr(VI) was about 2 and 10 minutes respectively. The optimum pH for total chromium removal occurred at pH 7 and maximum hexavalent chromium removal took place under acidic condition at pH 3. Investigating the isothermal characteristics showed that the equilibrium adsorption data fitted both Freundlich-s and Langmuir-s isotherms. The maximum adsorption of chromium was calculated 36.1 mg/g for polyaniline

Keywords: Polyaniline, Chromium, acetonitrile, Adsorption

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Authors: Bruna Luisa Ramos Prado Vasques, Mariane Rembold Petraglia, Antonio Petraglia

Abstract:

This paper investigates MIMO (Multiple-Input Multiple-Output) adaptive filtering techniques for the application of supervised source separation in the context of convolutive mixtures. From the observation that there is correlation among the signals of the different mixtures, an improvement in the NSAF (Normalized Subband Adaptive Filter) algorithm is proposed in order to accelerate its convergence rate. Simulation results with mixtures of speech signals in reverberant environments show the superior performance of the proposed algorithm with respect to the performances of the NLMS (Normalized Least-Mean-Square) and conventional NSAF, considering both the convergence speed and SIR (Signal-to-Interference Ratio) after convergence.

Keywords: Adaptive filtering, multirate processing, normalized subband adaptive filter, source separation.

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Authors: R. Blicha

Abstract:

High Peak to Average Power Ratio (PAPR) of the transmitted signal is a serious problem in multicarrier systems (MC), such as Orthogonal Frequency Division Multiplexing (OFDM), or in Multi-Carrier Code Division Multiple Access (MC-CDMA) systems, due to large number of subcarriers. This effect is possible reduce with some PAPR reduction techniques. Spreading sequences at the presence of Saleh and Rapp models of high power amplifier (HPA) have big influence on the behavior of system. In this paper we investigate the bit-error-rate (BER) performance of MC-CDMA systems. Basically we can see from simulations that the MC-CDMA system with Iterative algorithm can be providing significantly better results than the MC-CDMA system. The results of our analyses are verified via simulation.

Keywords: MC-CDMA, Iterative algorithm, PAPR, BER, Saleh, Rapp, Spreading Sequences.

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Authors: Narottam Chand

Abstract:

Wireless sensor networks (WSNs) have gained tremendous attention in recent years due to their numerous applications. Due to the limited energy resource, energy efficient operation of sensor nodes is a key issue in wireless sensor networks. Cooperative caching which ensures sharing of data among various nodes reduces the number of communications over the wireless channels and thus enhances the overall lifetime of a wireless sensor network. In this paper, we propose a cooperative caching scheme called ZCS (Zone Cooperation at Sensors) for wireless sensor networks. In ZCS scheme, one-hop neighbors of a sensor node form a cooperative cache zone and share the cached data with each other. Simulation experiments show that the ZCS caching scheme achieves significant improvements in byte hit ratio and average query latency in comparison with other caching strategies.

Keywords: Admission control, cache replacement, cooperative caching, WSN, zone cooperation

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Authors: Gülşah Çelik Gül, Figen Kurtuluş

Abstract:

Magnesium containing boron compounds with hexagonal structure have been drawn much attention due to their superconductive nature. The main target of this work is new modified microwave oven by on our own has an ability about passing through a gas in the oven medium for attainment of oxygen-free compounds such as c-BN.  Mg containing boride was synthesized by modified-microwave method under nitrogen atmosphere using amorphous boron and magnesium source in appropriate molar ratio. Microwave oven with oxygen free environment has been modified to aimed to obtain magnesium boride without oxygen. Characterizations were done by powder X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. Mg containing boride, generally named magnesium boride, with amorphous character without oxygen is obtained via designed microwave oven system.

Keywords: Magnesium containing boron compounds, modified microwave synthesis, powder X-ray diffraction, FTIR.

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Authors: T. Thitiapichart, P. Praserthdama

Abstract:

The effect of additional magnesium oxide (MgO) was investigated by using the tungsten oxide supported on silica catalyst (WOx/SiO2) physically mixed with MgO in a weight ratio 1:1. The both fresh and spent catalysts were characterized by FT-Raman spectrometer, UV-Vis spectrometer, X-Ray diffraction (XRD) and temperature programmed oxidation (TPO). The results indicated that the additional MgO could enhance the conversion of trans-2-butene due to isomerization reaction. However, adding MgO would increase the amount of coke deposit on the WOx/SiO2 catalyst. The TPO profile presented two peaks when the WOx/SiO2 catalyst was physically mixed with MgO. The further peak was suggested that came from coke precursor could be produced by isomerization reaction of undesired product. Then, the occurred coke precursor could deposit and form coke on the acid catalyst.

Keywords: Coke formation, metathesis, magnesium oxide, physically mix.

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Authors: Md. Sohidul Islam, Ahmad Fartheen Khan

Abstract:

In recent times, Non-Orthogonal Multiple Access (NOMA) has received significant attention as an upcoming candidate in the world of 5G systems. The main reason for getting NOMA in 5G is because of its capacity to provide services to many users who have the same time and frequency resources. It is best used as "multiple-input, multiple-output" (MIMO) technology. In this paper, we are going to investigate outage probability as a function of signal-to-noise ratio (SNR) and target rate user. These methods will be implemented using cooperative communication and fair power allocation, respectively.

Keywords: Non-orthogonal Multiple Access, Fair Power Allocation, Outage Probability, Target Rate User, Cooperative Communication, massive multiple input multiple output, MIMO, Successive Interference Cancellation.

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Authors: B. Cynthia Sherin, E. A. Mary Anita

Abstract:

Vehicular Ad-hoc Network (VANET) is an emerging and very promising technology that has great demand on the access capability of the existing wireless technology. VANETs help improve traffic safety and efficiency. Each vehicle can exchange their information to inform the other vehicles about the current status of the traffic flow or a dangerous situation such as an accident. To achieve these, a reliable and efficient Medium Access Control (MAC) protocol with minimal transmission collisions is required. High speed nodes, absence of infrastructure, variations in topology and their QoS requirements makes it difficult for designing a MAC protocol in vehicular networks. There are several MAC protocols proposed for VANETs to ensure that all the vehicles could send safety messages without collisions by reducing the end-to-end delay and packet loss ratio. This paper gives an overview of the several proposed MAC protocols for VANETs along with their benefits and limitations and presents an overall classification based on their characteristics.

Keywords: MAC Protocols, QoS, VANET, V2V, V2I.

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Authors: Vishnu Prasad Sharma, S. Kumaraswamy, A. Mani

Abstract:

This paper reports on the results of experimental investigations on the performance of a jet pump operated under selected primary flows to optimize the related parameters. For this purpose a two-phase flow jet pump was used employing various profiles of nozzles as the primary device which was designed, fabricated and used along with the combination of mixing tube and diffuser. The profiles employed were circular, conical, and elliptical. The diameter of the nozzle used was 4 mm. The area ratio of the jet pump was 0.16. The test facility created for this purpose was an open loop continuous circulation system. Performance of the jet pump was obtained as iso-efficiency curves on characteristic curves drawn for various water flow rates. To perform the suction capability, evacuation test was conducted at best efficiency point for all the profiles.

Keywords: Evacuation test, jet pump, nozzle profile, nozzle spacing, performance test, two phase flow

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Authors: J. E. Oti, J. M. Kinuthia, R. Robinson, P. Davies

Abstract:

In this study, the Compressive strength of concretes made with Ground Granulated Blast furnace Slag (GGBS), Pulverised Fuel Ash (PFA), Rice Husk Ash (RHA) and Waste Glass Powder (WGP) after they were exposed 7800C (exposure duration of around 60 minutes) and then allowed to cool down gradually in the furnace for about 280 minutes at water binder ratio of 0.50 was investigated. GGBS, PFA, RHA and WGP were used to replace up to 20% Portland cement in the control concrete. Test for the determination of workability, compressive strength and tensile splitting strength of the concretes were carried out and the results were compared with control concrete. The test results showed that the compressive strength decreased by an average of around 30% after the concretes were exposed to the heating and cooling scenario.

Keywords: Pulverised Fuel Ash, Rice Husk Ash, heating and cooling, concrete.

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Authors: Vu Ngoc Pi

Abstract:

This paper presents a new study on the applications of optimization and regression analysis techniques for optimal calculation of partial ratios of four-step helical gearboxes for getting minimal gearbox length. In the paper, basing on the moment equilibrium condition of a mechanic system including four gear units and their regular resistance condition, models for determination of the partial ratios of the gearboxes are proposed. In particular, explicit models for calculation of the partial ratios are proposed by using regression analysis. Using these models, the determination of the partial ratios is accurate and simple.

Keywords: Gearbox design; optimal design; helical gearbox, transmission ratio.

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Authors: Shwe Wut Hmon Aye, Kay Thi Lwin, Waing Waing Kay Khine Oo

Abstract:

As the material used for fuselage structure must possess low density, high strength to weight ratio, the selection of appropriate materials for fuselage structure is one of the most important tasks. Aluminum metal itself is soft and low in strength. It can be made stronger by giving proper combination of suitable alloy addition, mechanical treatment and thermal treatment. The usual thermal treatment given to aluminum alloys is called age-hardening or precipitation hardening. In this paper, the studies are carried out on 7075 aluminum alloy which is how to improve strength level for fuselage structure. The marked effect of the strength on the ternary alloy is clearly demonstrated at several ageing times and temperatures. It is concluded that aluminum-zinc-magnesium alloy can get the highest strength level in natural ageing.

Keywords: Aluminum alloy, ageing, heat treatment, strength.

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Authors: E. Mulliner, V. Maliene

Abstract:

The concept of housing affordability is a contested issue, but a pressing and widespread problem for many countries. Simple ratio measures based on housing expenditure and income are habitually used to defined and assess housing affordability. However, conceptualising and measuring affordability in this manner focuses only on financial attributes and fails to deal with wider issues such as housing quality, location and access to services and facilities. The research is based on the notion that the housing affordability problem encompasses more than the financial costs of housing and a households ability to meet such costs and must address larger issues such as social and environmental sustainability and the welfare of households. Therefore, the need arises for a broad and more encompassing set of attributes by which housing affordability can be assessed. This paper presents a system of criteria by which the affordability of different housing locations could be assessed in a comprehensive and sustainable manner. Moreover, the paper explores the way in which such criteria could be measured.

Keywords: Affordable housing, attributes, housing affordability, sustainable communities

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Authors: Rupaban Subadar

Abstract:

Performance of a dual maximal ratio combining receiver has been analyzed for M-ary coherent and non-coherent modulations over correlated Nakagami-m fading channels with nonidentical and arbitrary fading parameter. The classical probability density function (PDF) based approach is used for analysis. Expressions for outage probability and average symbol error performance for M-ary coherent and non-coherent modulations have been obtained. The obtained results are verified against the special case published results and found to be matching. The effect of the unequal fading parameters, branch correlation and unequal input average SNR on the receiver performance has been studied.

Keywords: MRC, correlated Nakagami-m fading, non-identicalfading statistics, average symbol error rate

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Authors: Omid A. Zargar

Abstract:

Vibration monitoring methods of most critical equipment like main turbine and compressors always plays important role in preventive maintenance and management consideration in big industrial plants. There are a number of traditional methods like monitoring the overall vibration data from Bently Nevada panel and the time wave form (TWF) or fast Fourier transform (FFT) monitoring. Besides, Shaft centerline monitoring method developed too much in recent years. There are a number of arguments both in favor of and against this method between people who work in preventive maintenance and condition monitoring systems (vibration analysts). In this paper basic principal of Turbine compressor vibration analysis and rotor movement evaluation by shaft centerline method discussed in details through a case history. This case history is related to main turbine compressor of an olefin plant in Iran oil industry. In addition, some common mistakes that may occur by vibration analyst during the process discussed in details. It is worthy to know that, these mistakes may one of the reasons that sometimes this method seems to be not effective. Furthermore, recent patent and innovation in shaft position and movement evaluation are discussed in this paper.

Keywords: Shaft centerline position, attitude angle, journal bearing, sleeve bearing, tilting pad, steam turbine, main compressor, multistage compressor, condition monitoring, non-contact probe

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Authors: Min Ho Kwon, Woo Young Jung, Hyun Su Seo

Abstract:

A polymer cement mortar (PCM) has been widely used  as the material of repair and restoration work for concrete structure;  however a PCM usually induces an environmental pollutant.  Therefore, there is a need to develop PCM which is less impact to  environments. Usually, UM resin is known to be harmless to the  environment. Accordingly, in this paper, the properties of the PCM  using UM resin were studied. The general cement mortar and UM  resin were mixed in the specified ratio. A certain percentage of PVA  fibers, steel fibers and mixed fibers (PVA fiber and steel fiber) were  added to enhance the flexural strength. The flexural tests were  performed in order to investigate the flexural strength of each PCM.  Experimental results showed that the strength of proposed PCM using  UM resin is improved when they are compared with general cement  mortar.

 

Keywords: Polymer cement mortar (PCM), UM resin, Compressive strength, PVA fiber, Steel fiber.

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Authors: Nuray Uçar, Mervin Ölmez, Özge Alptoğa, Nilgün K. Yavuz, Ayşen Önen

Abstract:

In recent years, research on continuous graphene oxide fibers has been intensified. Therefore, many factors of production stages are being studied. In this study, the effect of exfoliation time and presence of activated carbon particle (ACP) on graphene oxide fiber’s properties has been analyzed. It has been seen that cross-sectional appearance of sample with ACP is harsh and porous because of ACP. The addition of ACP did not change the electrical conductivity. However, ACP results in an enormous decrease of mechanical properties. Longer exfoliation time results to higher crystallinity degree, C/O ratio and less d space between layers. The breaking strength and electrical conductivity of sample with less exfoliation time is some higher than sample with high exfoliation time.

Keywords: Activated carbon, coagulation by wet spinning, exfoliation, graphene oxide fiber.

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