Search results for: base polymer

Authors: Marta Chiapasco, Alexandra Porter, Finn Giuliani

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Designing polymers with a specific microstructure can affect how the polymer degrades once released in the environment. Not only the amount but also the distribution of different phases determines a polymers’ degradability. The following research investigates the use of a combination of spectroscopy analysis and thermal analysis to study changes of polymers’ amorphous and crystalline phases during degradation, comparing different microstructures of polypropylene and polyethylene. The use of nanoindentation helps study how degradation proceeds across a material by looking at changes in phases, while bulk tensile test describes when the material fails. The first results demonstrate that different microstructures have different degrading rates, with homopolymer having a linear and faster degradation compared to copolymers. The goal is to create materials that degrade at faster rates without releasing microplastics into the environment.

Keywords: degradation, microstructure, nanoindentation, Raman spectroscopy

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Authors: Khalid Javed

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This study examines a feature of the budget process called the tax expenditure budget. The tax expenditure concept relies heavily on a normative notion that shielding certain. Taxpayer income from taxation deprives government of its rightful revenues. This view is inconsistent with the proposition that income belongs to the taxpayers and that tax liability is determined through the democratic process, not through arbitrary, bureaucratic Assumptions. Furthermore, the methodology of the tax expenditure budget is problematic as its expansive tax base treats the multiple taxation of saving as the norm. By using an expansive view of income as the underlying assumption of the tax expenditure concept, this viewpoint institutionalizes a particular bias into the decision-making process.

Keywords: revenue, expenditure, tax budget, propostion

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Authors: Donald Zullick, Cihan Varol

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This research paper begins with a look at current work in business continuity as it relates to the cloud and small to medium business (SMB). While cloud services are an emerging paradigm that is quickly making an impact on business, there has been no substantive research applied to SMB. Seeing this lapse, we have taken a fusion of continuity and cloud research with application to the SMB market. It is an initial reflection with base framework guidelines as a starting point for implementation. In this approach, our research ties together existing work and fill the gap with an SMB outlook.

Keywords: business continuity, cloud services, medium size business, risk assessment, small business

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Authors: Parth Prajapati, A. R. Srinivas

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The purpose of this paper is to validate the concept of the Lotus Mechanism using Computer Aided Engineering (CAE) tools considering the statics and dynamics through actual time dependence involving inertial forces acting on the mechanism joints. For a 1.2 m mirror made of hexagonal segments, with simple harnesses and three-point supports, the maximum diameter is 400 mm, minimum segment base thickness is 1.5 mm, and maximum rib height is considered as 12 mm. Manufacturing challenges are explored for the segments using manufacturing research and development approaches to enable use of large lightweight mirrors required for the future space system.

Keywords: dynamics, manufacturing, reflectors, segmentation, statics

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Authors: Yashfeen Khan, Anees Ahmad

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In the last few decades, nano-composites have been the topic of interest. Presently, the modern era enlightens the synthesis of hybrid nano-composites over their individual counterparts because of higher application potentials and synergism. Recently, CNT hybrids have demonstrated their pronounced capability as effective sorbents for the removal of heavy metal ions (the root trouble) and organic contaminants due to their high specific surface area, enhanced reactivity, and sequestration characteristics. The present abstract discusses removal efficiencies of organic, inorganic pollutants through CNT/PANI/ composites. It also represents the widespread applications of CNT like monitoring biological systems, biosensors, as heat resources for treating cancer, fire retardant applications of polymer/CNT composites etc. And considering the same, this article aims to brief the scenario of CNT-PANI nano-composites.

Keywords: biosensors, CNT, hybrids, polyaniline, synergism

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Authors: Saradha Priya

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Developing virtual human is very important to meet the challenges occurred in many applications where human find difficult or risky to perform the task. A robot is a machine that can perform a task automatically or with guidance. Robotics is generally a combination of artificial intelligence and physical machines (motors). Computational intelligence involves the programmed instructions. This project proposes a robotic vehicle that has a camera, PIR sensor and text command based movement. It is specially designed to perform surveillance and other few tasks in the most efficient way. Serial communication has been occurred between a remote Base Station, GUI Application, and PC.

Keywords: Zigbee, camera, pirsensor, wireless transmission, DC motor

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Authors: Hamidreza Bayat, Arash Mirabdolah Lavasani, Meysam Bolhasani, Sajad Moosavi

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Flow around a flat tube is studied numerically. Reynolds number is defined base on equivalent circular tube and it is varied in range of 100 to 300. Equations are solved by using finite volume method and results are presented in form of drag and lift coefficient. Results show that drag coefficient of flat tube is up to 66% lower than circular tube with equivalent diameter. In addition, by increasing l/D from 1 to 2, the drag coefficient of flat tube is decreased about 14-27%.

Keywords: laminar flow, flat-tube, drag coefficient, cross-flow, heat exchanger

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Authors: E. V. Kuzmicheva

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An attention is concentrated on a service quality estimation of sport services. A typical mathematical model was developed at the base of the «general economic theory of mass service» accounting pedagogical requirements of fitness services. Also it took into account a dependence of the club member number versus on a value of square of sport facilities. Final recommendations were applied to the fitness club resulted in some improvement of the quality sport service, an increasing of the revenue from club members and profit of clubs.

Keywords: fitness club, efficiency of operation, facilities, service quality, mass service

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Authors: Ali Mohammadi

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The basis for the construction of any project is a map, a map where the surveyor can determine the coordinates of the points on the ground by using the coordinates and using the total station, projects such as dams, roads, tunnels and pipelines, if the base points are determined using GPS prepared can create challenges for the surveyor to control. First, we will examine some map projection on which the maps are designed, and a summary of their differences and the challenges that surveyors face in order to control them, because in order to build projects, we need real lengths and angles, so we have to use coordinates that provide us with the results of the calculations. We will examine some examples to understand the concept of localization so that the surveyor knows if he is facing a challenge or not and if he is faced with this challenge, how should he solve this problem.

Keywords: UTM, scale factor, cartesian, traverse

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Authors: Sperisa Distantina, Fadilah, Mujtahid Kaavessina

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Crosslinked konjac glucomannan and kappa carrageenan film were prepared by chemical crosslinking using glutaraldehyde (GA) as the crosslinking agent. The effect crosslinking on the swelling degree was investigated. Konjac glucomanan and its mixture with kappa carragenan film was immersed in GA solution and then thermally cured. The obtained crosslinked film was washed and soaked in the ethanol to remove the unreacted GA. The obtained film was air dried at room temperature to a constant weight. The infrared spectra and the value of swelling degree of obtained crosslinked film showed that glucomannan and kappa carrageenan was able to be crosslinked using glutaraldehyde by film immersion and curing method without catalyst. The crosslinked films were found to be pH sensitive, indicating a potential to be used in drug delivery polymer system.

Keywords: crosslinking, glucomannan, carrageenan, swelling

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Authors: Duy Cuong Nguyen, Ali Makke, Guillaume Montay

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This work presents an improved single fiber pull-out test for fiber/matrix interface characterization. This test has been used to study the Inter-Facial Shear Strength ‘IFSS’ of hemp fibers reinforced polypropylene (PP). For this aim, the fiber diameter has been carefully measured using a tomography inspired method. The fiber section contour can then be approximated by a circle or a polygon. The results show that the IFSS is overestimated if the circular approximation is used. The Influence of the molding temperature on the IFSS has also been studied. We find a molding temperature of 183°C leads to better interface properties. Above or below this temperature the interface strength is reduced.

Keywords: composite, hemp, interface, pull-out, processing, polypropylene, temperature

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Authors: Mariam A. Abu-Alim

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The purpose of this study was to validate muscle activation amplitudes of two field base dynamic balance tests that are used as strengthen and motor control exercises too in the activation of selected hip and knee stabilizer muscles. Methods: Eighteen college-age females students (21±2 years; 65.6± 8.7 kg; 169.7±8.1 cm) who participated at least for 30 minutes in physical activity most days of the week volunteered. The wireless BIOPAC (MP150, BIOPAC System. Inc, California, USA) surface electromyography system was used to validate the activation of the Gluteus Medius and the Adductor Magnus of hip stabilizer muscles; and the Hamstrings, Quadriceps, and the Gastrocnemius of the knee stabilizer muscles. Surface electrodes (EL 503, BIOPAC, System. Inc) connected to dual wireless EMG BioNormadix Transmitters were place on selected muscles of participants dominate side. Manual muscle testing was performed to obtain the maximal voluntary isometric contraction (MVIC) in which all collected muscle activity data during the three reaching direction: anterior, posteromedial, posterolateral of the Star Excursion Balance Test (SEBT) and the Y-balance Test (YBT) data could be normalized. All participants performed three trials for each reaching direction of the SEBT and the YBT. The domanial leg trial for each participant was selected for analysis which was also the standing leg. Results: the selected hip stabilizer muscles (Gluteus Medius, Adductor Magnus) were both greater than 100%MVIC during the performance of the SEBT and in all three directions. Whereas, selected knee stabilizer muscles had greater activation 0f 100% MVIC and were significantly more activated during the performance of the YBT test in all three reaching directions. The results showed that the posterolateral and the postmedial reaching directions for both dynamic balance tests had greater activation levels and greater than 200%MVIC for all tested muscles expect of the hamstrings. Conclusion: the results of this study showed that the SEBT and the YBT had validated high levels of muscular activity for the hip and the knee stabilizer muscles; which can be used to represent the improvement, strength, control and the decreasing in the injury levels. Since these selected hip and knee stabilizer muscles, represent 35% of all athletic injuries depending on the type of sport.

Keywords: dynamic balance tests, electromyography, hip stabilizer muscles, nee stabilizer muscles

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Authors: Kang Woobang

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The base of the column is not only a support but also the embodiment of profound symbolism full of cosmic energy. Finding the full jars from which various energy emanate at the Notre Dame of Paris and Saint-Germain-des-Pres in France, the author was so shocked. As the column is cosmic tree, from the Full Jar full with cosmic energy emerges the cosmic tree composed of shaft and capital.

Keywords: full picher or jar, transcendental or supernatural birth from yonggi, yonggimun, yonggissak

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Authors: Mojdeh Mohseni

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In the context of tissue engineering, the effect of microtopography as afforded by scaffold morphology is an important design parameter. Since the morphology of pores can effect on cell behavior, in this study, porous Chitosan (CHIT) - Gelatin (GEL)- Alginate (ALG) scaffolds with microtubule orientation structure were manufactured by unidirectional freeze-drying method and the effect of pore morphology on differentiation of Mesenchymal Stem Cells (MSCs) was investigated. This study showed that, the provided scaffold with natural polymer had good properties for cell behavior and the pores with highest orientation rate have produced appropriate substrate for the differentiation of stem cells.

Keywords: Chitosan, gelatin, Alginate, pore morphology, stem cell differentiation

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Authors: Pedro G. Morouço

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One utmost challenge in Tissue Engineering is the production of 3D constructs capable of mimicking the functional hierarchy of native tissues. This is well stated for osteochondral tissue due to the complex mechanical functional unit based on the junction of articular cartilage and bone. Thus, the aim of the present study was to develop a new additive manufacturing system coupling micro-extrusion with hydrogels printing. An integrated system was developed with 2 main features: (i) the printing of up to three distinct hydrogels; (ii) in coordination with the printing of a thermoplastic structural support. The hydrogel printing module was projected with a ‘revolver-like’ system, where the hydrogel selection was made by a rotating mechanism. The hydrogel deposition was then controlled by pressured air input. The use of specific components approved for medical use was incorporated in the material dispensing system (Nordson EDF Optimum® fluid dispensing system). The thermoplastic extrusion modulus enabled the control of required extrusion temperature through electric resistances in the polymer reservoir and the extrusion system. After testing and upgrades, a hydrogel modulus with 3 syringes (3cm3 capacity each), with a pressure range of 0-2.5bar, a rotational speed of 0-5rpm, and working with needles from 200-800µm was obtained. This modulus was successfully coupled to the extrusion system that presented a temperature up to 300˚C, a pressure range of 0-12bar, and working with nozzles from 200-500µm. The applied motor could provide a velocity range 0-2000mm/min. Although, there are distinct printing requirements for hydrogels and polymers, the novel system could develop hybrid scaffolds, combining the 2 moduli. The morphological analysis showed high reliability (n=5) between the theoretical and obtained filament and pore size (350µm and 300µm vs. 342±4µm and 302±3µm, p>0.05, respectively) of the polymer; and multi-material 3D constructs were successfully obtained. Human tissues present very distinct and complex structures regarding their mechanical properties, organization, composition and dimensions. For osteochondral regenerative medicine, a multiphasic scaffold is required as subchondral bone and overlying cartilage must regenerate at the same time. Thus, a scaffold with 3 layers (bone, intermediate and cartilage parts) can be a promising approach. The developed system may give a suitable solution to construct those hybrid scaffolds with enhanced properties. The present novel system is a step-forward regarding osteochondral tissue engineering due to its ability to generate layered mechanically stable implants through the double-printing of hydrogels with thermoplastics.

Keywords: 3D bioprinting, bone regeneration, cartilage regeneration, regenerative medicine, tissue engineering

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Authors: M. Maier, I. Dedigama, J. Majasan, Y. Wu, Q. Meyer, L. Castanheira, G. Hinds, P. R. Shearing, D. J. L. Brett

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Increasing the efficiency of electrolyser technology is commonly seen as one of the main challenges on the way to the Hydrogen Economy. There is a significant lack of understanding of the different states of operation of polymer electrolyte membrane water electrolysers (PEMWE) and how these influence the overall efficiency. This in particular means the two-phase flow through the membrane, gas diffusion layers (GDL) and flow channels. In order to increase the efficiency of PEMWE and facilitate their spread as commercial hydrogen production technology, new analytic approaches have to be found. Acoustic emission (AE) offers the possibility to analyse the processes within a PEMWE in a non-destructive, fast and cheap in-situ way. This work describes the generation and analysis of AE data coming from a PEM water electrolyser, for, to the best of our knowledge, the first time in literature. Different experiments are carried out. Each experiment is designed so that only specific physical processes occur and AE solely related to one process can be measured. Therefore, a range of experimental conditions is used to induce different flow regimes within flow channels and GDL. The resulting AE data is first separated into different events, which are defined by exceeding the noise threshold. Each acoustic event consists of a number of consequent peaks and ends when the wave diminishes under the noise threshold. For all these acoustic events the following key attributes are extracted: maximum peak amplitude, duration, number of peaks, peaks before the maximum, average intensity of a peak and time till the maximum is reached. Each event is then expressed as a vector containing the normalized values for all criteria. Principal Component Analysis is performed on the resulting data, which orders the criteria by the eigenvalues of their covariance matrix. This can be used as an easy way of determining which criteria convey the most information on the acoustic data. In the following, the data is ordered in the two- or three-dimensional space formed by the most relevant criteria axes. By finding spaces in the two- or three-dimensional space only occupied by acoustic events originating from one of the three experiments it is possible to relate physical processes to certain acoustic patterns. Due to the complex nature of the AE data modern machine learning techniques are needed to recognize these patterns in-situ. Using the AE data produced before allows to train a self-learning algorithm and develop an analytical tool to diagnose different operational states in a PEMWE. Combining this technique with the measurement of polarization curves and electrochemical impedance spectroscopy allows for in-situ optimization and recognition of suboptimal states of operation.

Keywords: acoustic emission, gas diffusion layers, in-situ diagnosis, PEM water electrolyser

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Authors: Young-Min Ko, Dong-Hyun Ha, Chang-Bin Ha, Hyoung-Kyu Song

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In recent years, a multi-antenna system is actively used to improve the performance of the communication. A MIMO-OFDM system can provide multiplexing gain or diversity gain. These gains are obtained in proportion to the increase of the number of antennas. In order to provide the optimal gain of the MIMO-OFDM system, various transmission and reception schemes are presented. This paper aims to propose a hybrid scheme that base station provides both diversity gain and multiplexing gain at the same time.

Keywords: DFE, diversity gain, hybrid, MIMO, multiplexing gain.

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Authors: A. Marolleau, F. Salaun, D. Dupont, H. Gidik, S. Ducept.

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The goal of this study is to analyze the hydric behaviour of textiles which can impact significantly the comfort of the wearer. Indeed, fabrics can be adapted for different climate if hydric and thermal behaviors are known. In this study, fabrics are only submitted to hydric variations. Sorption and desorption isotherms obtained from the dynamic vapour sorption apparatus (DVS) are fitted with the parallel exponential kinetics (PEK), the Hailwood-Horrobin (HH) and the Brunauer-Emmett-Teller (BET) models. One of the major finding is the relationship existing between PEK and HH models. During slow and fast processes, the sorption of water molecules on the polymer can be in monolayer and multilayer form. According to the BET model, moisture regain, a physical property of textiles, show a linear correlation with the total amount of water taken in monolayer. This study provides potential information of the end uses of these fabrics according to the selected activity level.

Keywords: comfort, hydric properties, modelling, underwears

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Authors: Vijayakameswara Rao Neralla, Jueun Jeon, Jae Hyung Park

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To develop a potential nanocarrier for diagnosis and treatment of rheumatoid arthritis (RA), we prepared a hyaluronic acid (HA)-5β-cholanic acid (CA) conjugate with an acid-labile ketal linker. This conjugate could self-assemble in aqueous conditions to produce pH-responsive HA-CA nanoparticles as potential carriers of the anti-inflammatory drug methotrexate (MTX). MTX was rapidly released from nanoparticles under inflamed synovial tissue in RA. In vitro cytotoxicity data showed that pH-responsive HA-CA nanoparticles were non-toxic to RAW 264.7 cells. In vivo biodistribution results confirmed that, after their systemic administration, pH-responsive HA-CA nanoparticles selectively accumulated in the inflamed joints of collagen-induced arthritis mice. These results indicate that pH-responsive HA-CA nanoparticles represent a promising candidate as a drug carrier for RA therapy.

Keywords: rheumatoid arthritis, hyaluronic acid, nanocarrier, self-assembly, MTX

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Authors: Fola John Adeyeye

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In this paper, we propose a cryptosystem private and public key base on symmetric group Pn and validates its theoretical formulation. This proposed system benefits from the algebraic properties of Pn such as noncommutative high logical, computational speed and high flexibility in selecting key which makes the discrete permutation multiplier logic (DPML) resist to attack by any algorithm such as Pohlig-Hellman. One of the advantages of this scheme is that it explore all the possible triangular symmetries. Against these properties, the only disadvantage is that the law of permutation multiplicity only allow an operation from left to right. Many other cryptosystems can be transformed into their symmetric group.

Keywords: cryptosystem, private and public key, DPML, symmetric group Pn

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Authors: Andrey Norov

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Reduction of inefficient losses of nutrients when using mineral fertilizers is a very important and urgent challenge, which is of both economic and environmental significance. The loss of nutrients to the environment leads to the release of greenhouse gases, eutrophication of water bodies, soil salinization and degradation, and other undesirable phenomena. This report focuses on slow and controlled release fertilizers produced through the application of inorganic coatings, which make the released nutrients plant-available. There are shown the advantages of these fertilizers their improved physical and chemical properties, as well as the effect of the coatings on yield growth and on the degree of nutrient efficiency. This type of fertilizers is an alternative to other polymer-coated fertilizers and is more ecofriendly. The production method is protected by the Russian patent.

Keywords: coatings, controlled release, fertilizer, nutrients, nutrient efficiency, yield increase

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Authors: Faroudja Meziani, Amar Kahil

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In order to study the variation in settlement of soil under a dyke dam, the modelisation in our study consists of applying an imposed displacement at the base of the mass of soil (consisting of a saturated sand). The imposed displacement follows the evolution of acceleration of the earthquake of Boumerdes 2003 in Algeria. Moreover, the gravity load is taken into consideration by taking account the specific weight of the materials constituting the dyke. The results obtained show that the gravity loads have a direct influence on the evolution of settlement, especially at the center of the dyke where these loads are higher.

Keywords: settlement, dynamic analysis, rockfill dam, effect of earthquake, soil dynamics

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Authors: M. Şahi̇n, E. Erdem, M. Saçak

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In this study, Na-smectite crystals purificated of bentonite were used after being swelling with benzyltributylammonium bromide (BTBAB) as alkyl ammonium salt. Swelling process was carried out using 0.2 g of BTBAB for smectite of 0.8 g with 4 h of mixing time after investigated conditions such as mixing time, the swelling agent amount. Then, the conductive poly(o-anisidine) (POA)/smectite nanocomposite was prepared in the presence of swollen Na-smectite using ammonium persulfate (APS) as oxidant in aqueous acidic medium. The POA content and conductivity of the prepared nanocomposite were systematically investigated as a function of polymerization conditions such as the treatment time of swollen smectite in monomer solution and o-anisidine/APS mol ratio. POA/smectite nanocomposite was characterized by XRD, FTIR and SEM techniques and was compared separately with components of composite.

Keywords: clay, composite, conducting polymer, poly(o-anisidine)

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Authors: K. Sever, Y. Seki, Z. Yenier, İ. Şen, M. Sarikanat

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It is known that Chitosan, as a natural polymer, has many excellent properties such as bicompotability, biodegradability and nontoxicity. Besides it has some limitations such as poor solubility in water and low conductivity in electrical devices and sensor applications. In order to improve electrical conductivity properties grapheme loading was conducted into chitosan. For this aim, chitosan solution was prepared in acidic condition and Graphene at different ratios was mixed with chitosan solution by the help of homogenizator. After film formation electrical conductivity values of chitosan and graphene loaded chitosan were determined. After grapheme loading into chitosan,solution significant increases in surface resistivity value of chitosan were observed. Besides variations on viscoeleastic properties with graphene loading was determined by dynamic mechanical analysis. Storage and Loss moduli were obtained for chitosan and grapheme loaded chitosan samples.

Keywords: chitosan, graphene, viscoelastic properties, electrical conductivity

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Authors: John T. Leman, James Gibson, Peter J. Bonitatibus

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There have been no potential clinically translatable developments of intravenous CT contrast materials over decades, and iodinated contrast agents (ICA) remain the only FDA-approved media for CT. Small molecule ICA used to highlight vascular anatomy have weak CT signals in large-to-obese patients due to their rapid redistribution from plasma into interstitial fluid, thereby diluting their intravascular concentration, and because of a mismatch of iodine’s K-edge and the high kVp settings needed to image this patient population. The use of ICA is also contraindicated in a growing population of renally impaired patients who are hypersensitive to these contrast agents; a transformative intravenous contrast agent with improved capabilities is urgently needed. Tantalum oxide nanoparticles (TaO NPs) with zwitterionic siloxane polymer coatings have high potential as clinically translatable general-purpose CT contrast agents because of (1) substantially improved imaging efficacy compared to ICA in swine/phantoms emulating medium-sized and larger adult abdomens and superior thoracic vascular contrast enhancement of thoracic arteries and veins in rabbit, (2) promising biological safety profiles showing near-complete renal clearance and low tissue retention at 3x anticipated clinical dose (ACD), and (3) clinically acceptable physiochemical parameters as concentrated bulk solutions(250-300 mgTa/mL). Here, we review requirements for general-purpose intravenous CT contrast agents in terms of patient safety, X-ray attenuating properties and contrast-producing capabilities, and physicochemical and pharmacokinetic properties. We report the current status of a TaO NP-based contrast agent, including chemical process technology developments and results of newly defined scaled-up processes for NP synthesis and purification, yielding reproducible formulations with appropriate size and concentration specifications. We discuss recent results of recent pre-clinical in vitro immunology, non-GLP high dose tolerability in rats (10x ACD), non-GLP long-term biodistribution in rats at 3x ACD, and non-GLP repeat dose in rats at ACD. We also include a discussion of NP characterization, in particular size-stability testing results under accelerated conditions (37C), and insights into TaO NP purity, surface structure, and bonding of the zwitterionic siloxane polymer coating by multinuclear (1H, 13C, 29Si) and multidimensional (2D) solution NMR spectroscopy.

Keywords: nanoparticle, imaging, diagnostic, process technology, nanoparticle characterization

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Authors: Rayenne Djemil

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The mechanism of oxidation reaction of linoleic acid C18: 2 (9 cis12) by singlet oxygen 1O2 were theoretically investigated via using quantum chemical methods. We explored the four reaction pathways at PM3, Hartree-Fock HF and, B3LYP functional associated with the base 6-31G (d) level. The results are in favor of the first and the last reaction ways. The transition states were found by QST3 method. Thus the pathways between the transition state structures and their corresponding minima have been identified by the IRC calculations. The thermodynamic study showed that the four ways of oxidation of linoleic acid are spontaneous, exothermic and, the enthalpy values confirm that conjugate hydroperoxydes are the most favorable products.

Keywords: echanism, quantum mechanics, oxidation, linoleic acid H

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Authors: J. R. Büttler, T. Pham

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Basic understanding of interfacial mechanisms is of importance for the development of polymer composites. For this purpose, we need techniques to analyze the quality of interphases, their chemical and physical interactions and their strength and fracture resistance. In order to investigate the interfacial phenomena in detail, advanced characterization techniques are favorable. Dynamic mechanical thermal analysis (DMTA) using a rheological system is a sensitive tool. T-peel tests were performed with this system, to investigate the temperature-dependent peel behavior of woven textile composites. A model system was made of polyamide (PA) woven fabric laminated with films of polypropylene (PP) or PP modified by grafting with maleic anhydride (PP-g-MAH). Firstly, control measurements were performed with solely PP matrixes. Polymer melt investigations, as well as the extensional stress, extensional viscosity and extensional relaxation modulus at -10°C, 100 °C and 170 °C, demonstrate similar viscoelastic behavior for films made of PP-g-MAH and its non-modified PP-control. Frequency sweeps have shown that PP-g-MAH has a zero phase viscosity of around 1600 Pa·s and PP-control has a similar zero phase viscosity of 1345 Pa·s. Also, the gelation points are similar at 2.42*104 Pa (118 rad/s) and 2.81*104 Pa (161 rad/s) for PP-control and PP-g-MAH, respectively. Secondly, the textile composite was analyzed. The extensional stress of PA66 fabric laminated with either PP-control or PP-g-MAH at -10 °C, 25 °C and 170 °C for strain rates of 0.001 – 1 s^-1 was investigated. The laminates containing the modified PP need more stress for T-peeling. However, the strengthening effect due to the modification decreases by increasing temperature and at 170 °C, just above the melting temperature of the matrix, the difference disappears. Independent of the matrix used in the textile composite, there is a decrease of extensional stress by increasing temperature. It appears that the more viscous is the matrix, the weaker the laminar adhesion. Possibly, the measurement is influenced by the fact that the laminate becomes stiffer at lower temperatures. Adhesive lap-shear testing at room temperature supports the findings obtained with the T-peel test. Additional analysis of the textile composite at the microscopic level ensures that the fibers are well embedded in the matrix. Atomic force microscopy (AFM) imaging of a cross section of the composite shows no gaps between the fibers and matrix. Measurements of the water contact angle show that the MAH grafted PP is more polar than the virgin-PP, and that suggests a more favorable chemical interaction of PP-g-MAH with PA, compared to the non-modified PP. In fact, this study indicates that T-peel testing by DMTA is a technique to achieve more insights into polymeric textile composites.

Keywords: dynamic mechanical thermal analysis, interphase, polyamide, polypropylene, textile composite

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Authors: Elżbieta Cygan, Bączek, Piotr Wyżga

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This paper presents the results of research on the physical, mechanical, and tribological properties of materials constituting the matrix in sintered metallic-diamond tools. The ground powders based on the Fe-Mn-Cu-Sn-C system were modified with micro-sized particles of the ceramic phase: SiC, Al₂O₃ and consolidated using the SPS (spark plasma sintering) method to a relative density of over 98% at 850-950°C, at a pressure of 35 MPa and time 10 min. After sintering, an analysis of the microstructure was conducted using scanning electron microscopy. The resulting materials were tested for the apparent density determined by Archimedes’ method, Rockwell hardness (scale B), Young’s modulus, as well as for technological properties. The performance results of obtained diamond composites were compared with the base material (Fe–Mn–Cu–Sn–C) and the commercial alloy Co-20% WC. The hardness of composites has achieved the maximum at a temperature of 900°C; therefore, it should be considered that at this temperature it was obtained optimal physical and mechanical properties of the subjects' composites were. Research on tribological properties showed that the composites modified with micro-sized particles of the ceramic phase are characterized by more than twice higher wear resistance in comparison with base materials and the commercial alloy Co-20% WC. Composites containing Al₂O₃ phase particles in the matrix material were composites containing Al₂O₃ phase particles in the matrix material were characterized by the lowest abrasion wear resistance. The manufacturing technology presented in the paper is economically justified and can be successfully used in the production process of the matrix in sintered diamond-impregnated tools used for the machining of an industrial floor system. Acknowledgment: The study was performed under LIDER IX Research Project No. LIDER/22/0085/L-9/17/NCBR/2018 entitled “Innovative metal-diamond tools without the addition of critical raw materials for applications in the process of grinding industrial floor systems” funded by the National Centre for Research and Development of Poland, Warsaw.

Keywords: abrasive wear resistance, metal matrix composites, sintered diamond tools, Spark Plasma Sintering

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Authors: Sudarsan Jayasingh, R. Venkatesh

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Increasing number of customers gets connected to social networking sites, such as Facebook and Twitter to details about the brand communications. This survey, based on a convenience sample, aimed to find the reason for the participants to like Facebook fan pages, how often they visit and interact with the pages that they like, and how is it related with their purchase behaviour. 104 respondents completed the online survey. Overall, the study aimed at determining whether or not creating and maintaining a Facebook fan page is a beneficial tool for brands to communicate with their consumer base.

Keywords: facebook brand pages, social media, consumer engagement, digital engagement, purchase behaviour

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Authors: Haesook Kim, Ha Na Ra, Mansu Kim, Hyun Gi Kim, Sung Soo Kim

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Epoxy-ZrP (α-zirconium phosphate) nanocomposites were coated on inorganic barrier layer such as sputtering and atomic layer deposition (ALD) to improve the barrier properties and protect the layer. ZrP nanoplatelets were synthesized using a reflux method and exfoliated in the polymer matrix. The barrier properties of coating layer were characterized by measuring water vapor transmission rate (WVTR). The WVTR dramatically decreased after epoxy-ZrP nanocomposite coating, while maintaining the optical properties. It was also investigated the effect of epoxy-ZrP coating on inorganic layer after bending and reliability test. The optimal structure composed of inorganic and epoxy-ZrP nanocomposite layers was used in organic light emitting diodes (OLED) encapsulation.

Keywords: α-zirconium phosphate, barrier properties, epoxy nanocomposites, OLED encapsulation

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