Search results for: Fiber Reinforcement Polymer

Authors: Seoyoun Kim, Chunghee Park

Abstract:

Microplastics have recently become an issue due to their potentially harmful effects on the marine environment and the human body. The purpose of this study is to investigate the correlation of fiber emissions during the home laundering with the fabric parameters such as yarn density, warp/weft density, and weave structure. Also, the effect of finishing treatments such as reactive dyeing, water-repellent finish, peach skin finish on fiber emissions was evaluated. Furthermore, we studied the biodegradability of fibers in the marine environment compared to those in soil burial and the impact of finishing treatment on the biodegradability. Biodegradability was evaluated by measuring BOD values and tensile strength reduction. The results showed that more fibers were released in the thicker yarn, lower weave density. Also, a weave structure which has less compactness, released more fibers. Peach skin finish with microfibers exposed on the surface caused more fiber release, whereas water-repellent finish reduced the fiber emission. In addition, the biodegradability of the fabrics submerged in the marine environment were lower compared with those buried in the soil. Also, the water-repellent fabric was less biodegradable than the untreated one. Further research is suggested considering the fabrics with various chemical components or geometry and their fouling behavior in the marine environment.

Keywords: biodegradation, fibers, microplastic, pollution

Procedia PDF Downloads 122

Authors: Olaf Visker, Arnout De Vries, Lambert Schomaker

Abstract:

Predictive policing refers to the usage of analytical techniques to identify potential criminal activity. It has been widely implemented by various police departments. Being a relatively new area of research, there are, to the author’s knowledge, no absolute tried, and true methods and they still exhibit a variety of potential problems. One of those problems is closely related to the lack of understanding of how acting on these prediction influence crime itself. The goal of law enforcement is ultimately crime reduction. As such, a policy needs to be established that best facilitates this goal. This research aims to find such a policy by using adversarial agent-based modeling in combination with modern reinforcement learning techniques. It is presented here that a baseline model for both law enforcement and criminal agents and compare their performance to their respective reinforcement models. The experiments show that our smart law enforcement model is capable of reducing crime by making more deliberate choices regarding the locations of potential criminal activity. Furthermore, it is shown that the smart criminal model presents behavior consistent with popular crime theories and outperforms the baseline model in terms of crimes committed and time to capture. It does, however, still suffer from the difficulties of capturing long term rewards and learning how to handle multiple opposing goals.

Keywords: adversarial, agent based modelling, predictive policing, reinforcement learning

Procedia PDF Downloads 140

Authors: Supriya Gupta, Paresh Chokshi

Abstract:

Polymer-particle interactions can be effectively utilized to produce composites that possess physicochemical properties superior to that of neat polymer. The incorporation of fillers with dimensions comparable to polymer chain size produces composites with extra-ordinary properties owing to very high surface to volume ratio. The dispersion of nanoparticles is achieved by inducing steric repulsion realized by grafting particles with polymeric chains. A comprehensive understanding of the interparticle interaction between these functionalized nanoparticles plays an important role in the synthesis of a stable polymer nanocomposite. With the focus on incorporation of clay sheets in a polymer matrix, we theoretically construct the polymer mediated interparticle potential for two nanosheets grafted with polymeric chains. The self-consistent field theory (SCFT) is employed to obtain the inhomogeneous composition field under equilibrium. Unlike the continuum models, SCFT is built from the microscopic description taking in to account the molecular interactions contributed by both intra- and inter-chain potentials. We present the results of SCFT calculations of the interaction potential curve for two grafted nanosheets immersed in the matrix of polymeric chains of dissimilar chemistry to that of the grafted chains. The interaction potential is repulsive at short separation and shows depletion attraction for moderate separations induced by high grafting density. It is found that the strength of attraction well can be tuned by altering the compatibility between the grafted and the mobile chains. Further, we construct the interaction potential between two nanosheets grafted with diblock copolymers with one of the blocks being chemically identical to the free polymeric chains. The interplay between the enthalpic interaction between the dissimilar species and the entropy of the free chains gives rise to a rich behavior in interaction potential curve obtained for two separate cases of free chains being chemically similar to either the grafted block or the free block of the grafted diblock chains.

Keywords: clay nanosheets, polymer brush, polymer nanocomposites, self-consistent field theory

Procedia PDF Downloads 244

Authors: Jayotpaul Chaudhuri, Lutz Goedeke, Torsten Hallenga, Peter Ehrhard

Abstract:

Purification of gases from aerosols or airborne particles via filters is widely applied in the industry and in our daily lives. This separation especially in the micron and submicron size range is a necessary step to protect the environment and human health. Fibrous filters are often employed due to their low cost and high efficiency. For designing any filter the two most important performance parameters are capture efficiency and pressure drop. Since the capture efficiency is directly proportional to the pressure drop which leads to higher operating costs, a detailed investigation of the separation mechanism is required to optimize the filter designing, i.e., to have a high capture efficiency with a lower pressure drop. Therefore a two-dimensional flow simulation around a single fiber using Ansys CFX and Matlab is used to get insight into the separation process. Instead of simulating a solid fiber, the present Ansys CFX model uses a fictitious domain approach for the fiber by implementing a momentum loss model. This approach has been chosen to avoid creating a new mesh for different fiber sizes, thereby saving time and effort for re-meshing. In a first step, only the flow of the continuous fluid around the fiber is simulated in Ansys CFX and the flow field data is extracted and imported into Matlab and the particle trajectory is calculated in a Matlab routine. This calculation is a Lagrangian, one way coupled approach for particles with all relevant forces acting on it. The key parameters for the simulation in both Ansys CFX and Matlab are the porosity ε, the diameter ratio of particle and fiber D, the fluid Reynolds number Re, the Reynolds particle number Rep, the Stokes number St, the Froude number Fr and the density ratio of fluid and particle ρf/ρp. The simulation results were then compared to the single fiber theory from the literature.

Keywords: BBO-equation, capture efficiency, CFX, Matlab, fibrous filter, particle trajectory

Procedia PDF Downloads 193

Authors: Srestha Chaturabul, Wanchalerm Srirachat, Thanaporn Wannachod, Prakorn Ramakul, Ura Pancharoen, Soorathep Kheawhom

Abstract:

The separation of mercury(II) from petroleum-produced water from the Gulf of Thailand was carried out using a hollow fiber supported liquid membrane system (HFSLM). Optimum parameters for feed pretreatment were 0.2 M HCl, 4% (v/v) Aliquat 336 for extractant and 0.1 M thiourea for stripping solution. The best percentage obtained for extraction was 99.73% and for recovery 90.11%, respectively. The overall separation efficiency noted was 94.92% taking account of both extraction and recovery prospects. The model for this separation developed along a combined flux principle i.e. convection–diffusion–kinetic. The results showed excellent agreement with theoretical data at an average standard deviation of 1.5% and 1.8%, respectively.

Keywords: separation, mercury(ii), petroleum produced water, hollow fiber, liquid membrane

Procedia PDF Downloads 288

Authors: Ali Akrmi, Mohamed Beji, Ahmed Baklouti, Fatma Djouani, Philippe Lang, Mohamed M. Chehimi

Abstract:

Poly(vinyl chloride) (PVC) is a highly versatile polymer with excellent balance of properties and numerous applications such as water pipes, packaging and polymer materials of importance in the biomedical sector. However, depending on the applications, it is necessary to modify PVC by mixing with a plasticizer; surface modification using plasma, surface grafting or flame treatment; or bulk chemical modification which affects the entire PVC chains at an extent that can be tuned by the polymer chemist. The targeted applications are improvement of chemical resistance, avoiding or limitation of migration of toxic plasticizers, improvement of antibacterial properties, or control of blood compatibility.

Keywords: poly(vinyl chloride), nucleophilic substitution, sulfonylcarbamates, XPS

Procedia PDF Downloads 684

Authors: Shoaei Shahram, Rafiei Felora

Abstract:

To study the effects of using superabsorbent polymers on physiological of maize in deficit Irrigation condition .an experiment carried out in split plot factorial based on completely Randomized Block design (RCBD) with three replication in 2012years. Deficit Irrigation was applied by three different Irrigation amount. Super absorbent polymers in 3 levels were and two veriety of maize allocated in sub plots. there was significant difference between Irrigation levels in all experimental Traits by increasing in deficit irrigation. Results of this research showed water stress significantly decreased relative water content (RWC) LAI,Ash percentage in both hybrids, and increased Cell membrane percentage and SPAD,ADF percent.whereas the application of super absorbent polymer compensated the negative effect of drought stress, especially in high rates of polymer application .These mentioned rates of polymer had the best effect to all of the studied traits. These findings can be suggested that the irrigation intervals of corn could be increased by application of super absorbent polymer.

Keywords: super absorbent, p hysiological, water stress, zea maize

Procedia PDF Downloads 313

Authors: Yihao Kuang, Bowen Ding

Abstract:

With the increasing scale and complexity of knowledge graph, modern knowledge graph contains more and more types of entity, relationship, and attribute information. Therefore, in recent years, it has been a trend for knowledge graph inference to use reinforcement learning to deal with large-scale, incomplete, and noisy knowledge graphs and improve the inference effect and interpretability. The Proximal Policy Optimization (PPO) algorithm utilizes a near-end strategy optimization approach. This allows for more extensive updates of policy parameters while constraining the update extent to maintain training stability. This characteristic enables PPOs to converge to improved strategies more rapidly, often demonstrating enhanced performance early in the training process. Furthermore, PPO has the advantage of offline learning, effectively utilizing historical experience data for training and enhancing sample utilization. This means that even with limited resources, PPOs can efficiently train for reinforcement learning tasks. Based on these characteristics, this paper aims to obtain a better and more efficient inference effect by introducing PPO into knowledge inference technology.

Keywords: reinforcement learning, PPO, knowledge inference

Procedia PDF Downloads 219

Authors: Abubakar Umar Birnin-yauri

Abstract:

Plastic wastes arising from Polyethylene (PE)-based materials are increasingly becoming environmental problem, this is owed to the fact that these PE waste materials will only decompose over hundreds, or even thousands of years, during which they cause serious environmental problems. In this research, Polymer blends prepared from PE, Cashewnut flour (CNF) and Gum Arabic (GA) were studied in order to assay their biodegradation potentials via composting method. Different sample formulations were made i.e., X1= (70% PE, 25% CNF and 5% GA, X2= (70% PE, 20% CNF and 10% GA), X3= (70% PE, 15% CNF and 15% GA), X4 = (70% PE, 10% CNF and 20% GA) and X5 = (70% PE, 5% CNF and 25% GA) respectively. The results obtained showed that X1 recorded weight loss of 9.89% of its original weight after the first 20 days and 37.45% after 100 day, and X2 lost 12.67 % after the first 20 days and 42.56% after 100day, sample X5 experienced the greatest weight lost in the two methods adopted which are 52.9% and 57.89%. Instrumental analysis such as Fourier Transform Infrared Spectroscopy, Thermogravimetric analysis and Scanning electron microscopy were performed on the polymer blends before and after biodegradation. The study revealed that the biodegradation of the polymer blends is influenced by the contents of both the CNF and GA added into the blends.

Keywords: polyethylene, cashewnut, gum Arabic, biodegradation, blend, environment

Procedia PDF Downloads 61

Authors: Hee Yong Kang, Hyeon Ho Shin, Jung Cheol Yoo, Il Taek Lee, Sung Mo Yang

Abstract:

Lightweight technology using composites is being developed for vehicle seat structures, and its design must meet the safety requirements. According to the Federal Motor Vehicle Safety Standard (FMVSS) 207 seating systems test procedure, the back moment load is applied to the seat back frame structure for the safety evaluation of the vehicle seat. The seat back frame using the composites is divided into three parts: upper part frame, and left- and right-side frame parts following the manufacturing process. When a rear moment load is applied to the seat back frame, the side frame receives the bending load and the torsional load at the same time. This results in the largest loaded strength. Therefore, strength test of the component unit is required. In this study, a component test method based on the FMVSS 207 seating systems test procedure was proposed for the strength analysis of bending load and torsional load of the automotive Bulk Molding Compound (BMC) Seat Back Side Frame. Moreover, strength evaluation according to the carbon band reinforcement was performed. The back-side frame parts of the seat that are applied to the test were manufactured through BMC that is composed of vinyl ester Matrix and short carbon fiber. Then, two kinds of reinforced and non-reinforced parts of carbon band were formed through a high-temperature compression molding process. In addition, the structure that is applied to the component test was constructed by referring to the FMVSS 207. Then, the bending load and the torsional load were applied through the displacement control to perform the strength test for four load conditions. The results of each test are shown through the load-displacement curves of the specimen. The failure strength of the parts caused by the reinforcement of the carbon band was analyzed. Additionally, the fracture characteristics of the parts for four strength tests were evaluated, and the weakness structure of the back-side frame of the seat structure was confirmed according to the test conditions. Through the bending and torsional strength test methods, we confirmed the strength and fracture characteristics of BMC Seat Back Side Frame according to the carbon band reinforcement. And we proposed a method of testing the part strength of a seat back frame for vehicles that can meet the FMVSS 207.

Keywords: seat back frame, bending and torsional strength, BMC (Bulk Molding Compound), FMVSS 207 seating systems

Procedia PDF Downloads 195

Authors: C. S. Wong, K. H. Badri, N. Ataollahi, K. P. Law, M. S. Su’ait, N. I. Hassan

Abstract:

Novel bio-based polymer electrolyte was synthesized with LiClO4 as the main source of charge carrier. Initially, polyurethane-LiClO4 polymer electrolytes were synthesized via polymerization method with different NCO/OH ratios and labelled as PU1, PU2, PU3, and PU4. Subsequently, the chemical, thermal properties and ionic conductivity of the films produced were determined. Fourier transform infrared (FTIR) analysis indicates the co-ordination between Li+ ion and polyurethane in PU1 due to the greatest amount of hard segment of polyurethane in PU1 as proven by soxhlet analysis. The structures of polyurethanes were confirmed by 13 nuclear magnetic resonance spectroscopy (13C NMR) and FTIR spectroscopy. Differential scanning calorimetry (DSC) analysis indicates PU 1 has the highest glass transition temperature (Tg) corresponds to the most abundant urethane group which is the hard segment in PU1. Scanning electron microscopy (SEM) of the PU-LiClO4 shows the good miscibility between lithium salt and the polymer. The study found that PU1 possessed the greatest ionic conductivity (1.19 × 10-7 S.cm-1 at 298 K and 5.01 × 10-5 S.cm-1 at 373 K) and the lowest activation energy, Ea (0.32 eV) due to the greatest amount of hard segment formed in PU 1 induces the coordination between lithium ion and oxygen atom of carbonyl group in polyurethane. All the polyurethanes exhibited linear Arrhenius variations indicating ion transport via simple lithium ion hopping in polyurethane. This research proves the NCO content in polyurethane plays an important role in affecting the ionic conductivity of this polymer electrolyte.

Keywords: ionic conductivity, palm kernel oil-based monoester-OH, polyurethane, solid polymer electrolyte

Procedia PDF Downloads 408

Authors: Sayed Isahaq Hossain, K. T. Chang, Moustapha Ndour

Abstract:

Inference of the phreatic line through earth dams is of paramount importance because it could be directly associated with piping phenomena which may lead to the dam failure. Normally in the field, the instrumentations such as ‘diver’ and ‘standpipe’ are to be used to identify the seepage conditions which only provide point data with a fair amount of interpolation or assumption. Here in this paper, we employed high-resolution fiber optic cable sensors (FOCS) based on Raman Scattering in order to obtain a very accurate phreatic line and seepage profile. Unlike the above-mention devices which pinpoint the water level location, this kind of Distributed Fiber Optics Sensing gives us more reliable information due to its inherent characteristics of continuous measurement.

Keywords: standpipe, diver, FOCS, monitoring, Raman scattering

Procedia PDF Downloads 343

Authors: Shewangizaw Tesfaye Wolde

Abstract:

The current engineering community has developed a method called performance based seismic design in which we design structures based on predefined performance levels set by the parties. Since we design our structures economically for the maximum actions expected in the life of structures they go beyond their elastic limit, in need of nonlinear analysis. In this paper conventional pushover analysis (nonlinear static analysis) is used for the performance assessment of the case study Reinforced Concrete (RC) Frame building located in Addis Ababa City, Ethiopia where proposed peak ground acceleration value by RADIUS 1999 project and others is more than twice as of EBCS-8:1995 (RADIUS 1999 project) by taking critical planar frame. Fiber beam-column model is used to control material nonlinearity with tension stiffening effect. The reliability of the fiber model and validation of software outputs are checked under verification chapter. Therefore, the aim of this paper is to propose a way for structural performance assessment of existing reinforced concrete frame buildings as well as design check.

Keywords: seismic, performance, fiber model, tension stiffening, reinforced concrete

Procedia PDF Downloads 58

Authors: Monika Kamocka, Radoslaw Mania

Abstract:

The design of Fiber Metal Laminates - combining thin aluminum sheets and prepreg layers, allows creating a hybrid structure with high strength to weight ratio. This feature makes FMLs very attractive for aerospace industry, where thin-walled structures are commonly used. Nevertheless, those structures are prone to buckling phenomenon. Buckling could occur also under static load as well as dynamic pulse loads. In this paper, the problem of dynamic buckling of open cross-section FML profiles under axial dynamic compression in the form of pulse load of finite duration is investigated. In the numerical model, material properties of FML constituents were assumed as nonlinear elastic-plastic aluminum and linear-elastic glass-fiber-reinforced composite. The influence of pulse shape was investigated. Sinusoidal and rectangular pulse loads of finite duration were compared in two ways, i.e. with respect to magnitude and force pulse. The dynamic critical buckling load was determined based on Budiansky-Hutchinson, Ari Gur, and Simonetta dynamic buckling criteria.

Keywords: dynamic buckling, dynamic stability, Fiber Metal Laminate, Finite Element Method

Procedia PDF Downloads 175

Authors: Nassier A. Nassir, Robert Birch, Zhongwei Guan

Abstract:

The aim of this study is to investigate the fundamental science/technology related to novel S-glass fiber reinforced polyether- ketone-ketone (GF/PEKK) composites and to gain insight into bonding strength and failure mechanisms. Different manufacturing techniques to make this high-temperature pre-impregnated composite (prepreg) were conducted i.e. mechanical deposition, electrostatic powder deposition, and dry powder prepregging techniques. Generally, the results of this investigation showed that it was difficult to control the distribution of the resin powder evenly on the both sides of the fibers within a specific percentage. Most successful approach was by using a dry powder prepregging where the fibers were coated evenly with an adhesive that served as a temporary binder to hold the resin powder in place onto the glass fiber fabric.

Keywords: sry powder technique, PEKK, S-glass, thermoplastic prepreg

Procedia PDF Downloads 195

Authors: Niloofar Bahramian, Mohammad Atai, Mohammad Reza Naimi-Jamal

Abstract:

Rule of mixtures is the simple analytical model is used to predict various properties of composites before design. The aim of this study was to demonstrate the benefits and limitations of the Rule-of-Mixtures (ROM) for predicting bending modulus of a continuous and unidirectional fiber reinforced composites using in dental applications. The Composites were fabricated from light curing resin (with and without silica nanoparticles) and modified and non-modified fibers. Composite samples were divided into eight groups with ten specimens for each group. The bending modulus (flexural modulus) of samples was determined from the slope of the initial linear region of stress-strain curve on 2mm×2mm×25mm specimens with different designs: fibers corona treatment time (0s, 5s, 7s), fibers silane treatment (0%wt, 2%wt), fibers volume fraction (41%, 33%, 25%) and nanoparticles incorporation in resin (0%wt, 10%wt, 15%wt). To study the fiber and matrix interface after fracture, single edge notch beam (SENB) method and scanning electron microscope (SEM) were used. SEM also was used to show the nanoparticles dispersion in resin. Experimental results of bending modulus for composites made of both physical (corona) and chemical (silane) treated fibers were in reasonable agreement with linear ROM estimates, but untreated fibers or non-optimized treated fibers and poor nanoparticles dispersion did not correlate as well with ROM results. This study shows that the ROM is useful to predict the mechanical behavior of unidirectional dental composites but fiber-resin interface and quality of nanoparticles dispersion play important role in ROM accurate predictions.

Keywords: bending modulus, fiber reinforced composite, fiber treatment, rule-of-mixtures

Procedia PDF Downloads 263

Authors: J. Kosikova, B. Vacenovska, M. Vyhnankova

Abstract:

The paper reports on the subject of recycling and further use of secondary raw materials obtained from solar panels, which is becoming a very up to date topic in recent years. Recycling these panels is very difficult and complex, and the use of resulting secondary raw materials is still not fully resolved. Within the research carried out at the Brno University of Technology, new polymer materials used for industrial floors are being developed. Secondary raw materials are incorporated into these polymers as fillers. One of the tested filler materials was glass obtained from solar panels. The following text describes procedures and results of the tests that were performed on these materials, confirming the possibility of the use of solar panel glass in industrial polymer flooring systems.

Keywords: fillers, industrial floors, recycling, secondary raw material, solar panel

Procedia PDF Downloads 275

Authors: Arun Sanjel, Greg Speegle

Abstract:

Every second, massive amounts of data are generated, and Data Intensive Scalable Computing (DISC) frameworks have evolved into effective tools for analyzing such massive amounts of data. Since the underlying architecture of these distributed computing platforms is often new to users, building a DISC application can often be time-consuming and prone to errors. The automated conversion of a sequential program to a DISC program will consequently significantly improve productivity. However, synthesizing a user’s intended program from an input specification is complex, with several important applications, such as distributed program synthesizing and code refactoring. Existing works such as Tyro and Casper rely entirely on deductive synthesis techniques or similar program synthesis approaches. Our approach is to develop a data-driven synthesis technique to identify sequential components and translate them to equivalent distributed operations. We emphasize using reinforcement learning and unit testing as feedback mechanisms to achieve our objectives.

Keywords: program synthesis, distributed computing, reinforcement learning, unit testing, DISC

Procedia PDF Downloads 86

Authors: Vijaya Yuvaram Singh V M, Kameshwar Rao J V

Abstract:

The challenge with development of neural network based methods for medical is the availability of data. Anatomical landmark detection in the medical domain is a process to find points on the x-ray scan report of the patient. Most of the time this task is done manually by trained professionals as it requires precision and domain knowledge. Traditionally object detection based methods are used for landmark detection. Here, we utilize reinforcement learning and query based method to train a single agent capable of detecting multiple landmarks. A deep Q network agent is trained to detect single and multiple landmarks present on hip and shoulder from x-ray scan of a patient. Here a single agent is trained to find multiple landmark making it superior to having individual agents per landmark. For the initial study, five images of different patients are used as the environment and tested the agents performance on two unseen images.

Keywords: reinforcement learning, medical landmark detection, multi target detection, deep neural network

Procedia PDF Downloads 134

Authors: Adishirin Mammadov

Abstract:

Polymers and polymer composites play vital roles in diverse industries, including food and beverage packaging, transportation innovations, and medical advancements. However, the advancements in polymer technology bring certain risks, particularly concerning water and soil pollution due to the presence of polymers. The creation of new polymers is a critical aspect of this field. While the primary focus is on improving their physical and chemical properties, ensuring their ecological compatibility is equally important. An advanced method for developing innovative polymer types involves integrating fillers with diverse characteristics, offering advantages such as cost reduction and improved quality indicators. In the conducted research, efforts were made to enhance environmental aspects by employing waste fillers. Specifically, low-density polyethylene (LDPE) was used as the polymer, and waste from cocoon factories was chosen as the filler. Following a process of cleaning, drying, and crushing the filler to specific dimensions, it was incorporated into polyethylene through a mechanical-chemical method under laboratory conditions. The varied rheological properties of the resulting polyethylene compositions examined at temperatures ranging from 145 to 165 degrees Celsius. These compositions demonstrated different rheological properties at various temperature intervals. Achieving homogeneity in the obtained compositions is crucial in the polymers mechanochemical process. Beyond rheological properties, swelling rates in different environments and percentages of mass loss at different temperatures learned using the differential thermal analysis method. The research revealed that, to a certain extent, the physico-chemical properties of polyethylene were not significantly affected by the polymer compositions. This suggests that incorporating cocoon waste enables cost reduction in composite production while positively impacting the environment.

Keywords: polyethylene, polymer, composites, filler, reology

Procedia PDF Downloads 40

Authors: Pandiyarajan Thangaraj, Mangalaraja Ramalinga Viswanathan, Karthikeyan Balasubramanian, Héctor D. Mansilla, José Ruiz

Abstract:

Rare earth ions doped semiconductor nanostructures gained much attention due to their novel physical and chemical properties which lead to potential applications in laser technology as inexpensive luminescent materials. Doping of rare earth ions into ZnO semiconductor alter its electronic structure and emission properties. Surface modification (polymer covering) is one of the simplest techniques to modify the emission characteristics of host materials. The present work reports the synthesis and structural properties of PVA:Zn97Pr3O polymer nanocomposite free standing films. To prepare Pr3+ doped ZnO nanostructures and PVA:Zn97Pr3O polymer nanocomposite free standing films, the colloidal chemical and solution casting techniques were adopted, respectively. The formation of PVA:Zn97Pr3O films were confirmed through X-ray diffraction (XRD), absorption and Fourier transform infrared (FTIR) spectroscopy analyses. XRD measurements confirm the prepared materials are crystalline having hexagonal wurtzite structure. Polymer composite film exhibits the diffraction peaks of both PVA and ZnO structures. TEM images reveal the pure and Pr3+ doped ZnO nanostructures exhibit sheet like morphology. Optical absorption spectra show free excitonic absorption band of ZnO at 370 nm and, the PVA:Zn97Pr3O polymer film shows absorption bands at ~282 and 368 nm and these arise due to the presence of carbonyl containing structures connected to the PVA polymeric chains, mainly at the ends and free excitonic absorption of ZnO nanostructures, respectively. Transmission spectrum of as prepared film shows 57 to 69% of transparency in the visible and near IR region. FTIR spectral studies confirm the presence of A1 (TO) and E1 (TO) modes of Zn-O bond vibration and the formation of polymer composite materials.

Keywords: rare earth doped ZnO, polymer composites, structural characterization, surface modification

Procedia PDF Downloads 351

Authors: D. R. Rama Brahma Reddy, A. Vijaya Sarada Reddy

Abstract:

Nanoparticles represent a promising drug delivery system of controlled and targeted drug release. They are specially designed to release the drug in the vicinity of target tissue. The aim of this study was to prepare and evaluate polymethacrylic acid nanoparticles containing Zidovudine in different drug to polymer ratio by nanoprecipitation method. SEM indicated that nanoparticles have a discrete spherical structure without aggregation. The average particle size was found to be 120 ± 0.02 - 420 ± 0.05 nm. The particle size of the nanoparticles was gradually increased with increase in the proportion of polymethacrylic acid polymer. The drug content of the nanoparticles was increasing on increasing polymer concentration up to a particular concentration. No appreciable difference was observed in the extent of degradation of product during 60 days in which, nanoparticles were stored at various temperatures. FT-IR studies indicated that there was no chemical interaction between drug and polymer and stability of drug. The in-vitro release behavior from all the drug loaded batches was found to be zero order and provided sustained release over a period of 24 h. The developed formulation overcome and alleviates the drawbacks and limitations of Zidovudine sustained release formulations and could possibility be advantageous in terms of increased bio availability of Zidovudine.

Keywords: nanoparticles, zidovudine, biodegradable, polymethacrylic acid

Procedia PDF Downloads 606

Authors: Ahmet Kurklu, Abdussamed Sarp, Gokmen Arikan, Akin Eren, Arif Ulu, Ferit Cakir

Abstract:

Our natural resources are diminishing day by day with the needs of the growing world population. There is a danger that these resources will be depleted if they are not used in a controlled manner. As a result of the rapid increase in the consumption of limited natural resources, one of the issues where studies have gained importance is recycling. Many countries have carried out various research and development activities on recycling and reuse to prevent wastage of resources. For sustainable and healthy living, the limited amount of raw material resources in nature should be consumed consciously, and the necessary awareness should be given for recycling activities. One of the sectors where the consumption of raw materials is high is the construction sector. With the changing consumption habits of the evolving technology in the construction sector, the need to use special concrete along with the normal concrete has arisen. With the increasing need for specialty concretes, polymer concrete, which was discovered in the early 1900s, has evolved to the present day. Polymer concretes are special concretes with high strength, water impermeability, resistance to chemical action, and low surface roughness. Thanks to these properties, they find wide applications in many fields such as swimming pools, drainage systems, repair works. In the study, the effect of using recycled aggregates instead of natural aggregates in the production of polymer concrete on the performance of polymer concrete is investigated. In the experiments conducted for this purpose, the use of natural aggregate is reduced at certain rates, and instead, recycled aggregate is added at the same rate. The recycled aggregate to be used in the study is obtained from the polymer concrete drainage channel production facility of Mert Casting Co., Istanbul, Turkey. In order to clearly observe the effect of recycled materials on the product in the study, the other components (resin, hardener, accelerator, and additive) are kept constant in the concrete mix. In the study, fresh and hardened concrete tests are to be carried out on the mixes to be prepared.

Keywords: concrete, mechanical properties, polymer concrete, recycle aggregate

Procedia PDF Downloads 132

Authors: Ashima Rai

Abstract:

CATV transmission systems have altered from old cable based one-way analog video transmission to two ways hybrid fiber transmission. The use of optical fiber reduces the RF amplifiers in the transmission, high transmission power or lower fiber transmission losses are required to increase system capability. This paper evaluates and compares Distributed Feedback (DFB) laser and Vertical Cavity Surface Emitting Laser (VCSEL) for CATV transmission. The simulation results exhibit the better performer among both lasers taking into consideration the parameters chosen for evaluation.

Keywords: Distributed Feedback (DFB), Vertical Cavity Surface Emitting Laser (VCSEL), Community Access Television (CATV), Composite Second Order (CSO), Composite Triple Beat (CTB), RF

Procedia PDF Downloads 350

Authors: Žymantas Rudžionis, Paulius Grigaliūnas, Danutė Vaičiukynienė

Abstract:

By planning this experimental work to investigate the effect of zeolitic waste on rheological and technological properties of self-compacting fiber reinforced concrete, we had an intention to draw attention to the environmental factor. Large amount of zeolitic waste, as a secondary raw materials are not in use properly and large amount of it is collected without a clear view of it’s usage in future. The principal aim of this work is to assure, that zeolitic waste admixture takes positive effect to the self-compacting fiber reinforced concrete mixes stability, flowability and other properties by using the experimental research methods. In addition to that a research on cement and zeolitic waste mortars were implemented to clarify the effect of zeolitic waste on properties of cement paste and stone. Primary studies indicates that zeolitic waste characterizes clear puzzolanic behavior, do not deteriorate and in some cases ensure positive rheological and mechanical characteristics of self-compacting concrete mixes.

Keywords: self compacting concrete, steel fiber reinforced concrete, zeolitic waste, rheological, properties of concrete, slump flow

Procedia PDF Downloads 353

Authors: O. Hassoon, M. Tarfoui, A. El Malk

Abstract:

Fiber Bragg optic sensor embedded in composite material to detect and monitor the damage which is occur in composite structure. In this paper we deal with the mode-Ι delamination to determine the resistance of material to crack propagation, and use the coupling mode theory and T-matrix method to simulating the FBGs spectrum for both uniform and non-uniform strain distribution. The double cantilever beam test which is modeling in FEM to determine the Longitudinal strain, there are two models which are used, the first is the global half model, and the second the sub-model to represent the FBGs with refine mesh. This method can simulate the damage in the composite structure and converting the strain to wavelength shifting of the FBG spectrum.

Keywords: fiber bragg grating, delamination detection, DCB, FBG spectrum, structure health monitoring

Procedia PDF Downloads 352

Authors: Yanrong Song, Zikai Dong, Runqin Xu, Jinrong Tian, Kexuan Li

Abstract:

Nonlinear polarization rotation (NPR) technique has become one of the main techniques to achieve mode-locked fiber lasers for its compactness, implementation, and low cost. In this paper, we demonstrate a compact mode-locked Yb-doped fiber laser based on NPR technique in the all normal dispersion (ANDi) regime. In the laser cavity, there are no physical filter and polarization controller in laser cavity. Mode-locked pulse train is achieved in ANDi regime based on NPR technique. The fiber birefringence induced filtering effect is the mainly reason for mode-locking. After that, an extra 20 m long single-mode fiber is inserted in two different positions, dissipative soliton operation and noise like pulse operations are achieved correspondingly. The nonlinear effect is obviously enhanced in the noise like pulse regime and broadband spectrum generated owing to enhanced stimulated Raman scattering effect. When the pump power is 210 mW, the central wavelength is 1030 nm, and the corresponding 1st order Raman scattering stokes wave generates and locates at 1075 nm. When the pump power is 370 mW, the 1st and 2nd order Raman scattering stokes wave generate and locate at 1080 nm, 1126 nm respectively. When the pump power is 600 mW, the Raman continuum is generated with cascaded multi-order stokes waves, and the spectrum extends to 1188 nm. The total flat spectrum is from 1000nm to 1200nm. The maximum output average power and pulse energy are 18.0W and 14.75nJ, respectively.

Keywords: fiber laser, mode-locking, nonlinear polarization rotation, Raman scattering

Procedia PDF Downloads 211

Authors: Yihao Kuang, Bowen Ding

Abstract:

With the increasing scale and complexity of knowledge graph, modern knowledge graph contains more and more types of entity, relationship, and attribute information. Therefore, in recent years, it has been a trend for knowledge graph inference to use reinforcement learning to deal with large-scale, incomplete, and noisy knowledge graph and improve the inference effect and interpretability. The Proximal Policy Optimization (PPO) algorithm utilizes a near-end strategy optimization approach. This allows for more extensive updates of policy parameters while constraining the update extent to maintain training stability. This characteristic enables PPOs to converge to improve strategies more rapidly, often demonstrating enhanced performance early in the training process. Furthermore, PPO has the advantage of offline learning, effectively utilizing historical experience data for training and enhancing sample utilization. This means that even with limited resources, PPOs can efficiently train for reinforcement learning tasks. Based on these characteristics, this paper aims to obtain better and more efficient inference effect by introducing PPO into knowledge inference technology.

Keywords: reinforcement learning, PPO, knowledge inference, supervised learning

Procedia PDF Downloads 46

Authors: M. Kamil, Rahber Husain Khan

Abstract:

In the present study, the Interaction of anionic polymer, sodium carboxymethylcellulose (NaCMC), with cationic gemini surfactants 2,2[(oxybis(ethane-1,2-diyl))bis(oxy)]bis(N-hexadecyl1-N,N-[di(E2)/tri(E3)]methyl1-2-oxoethanaminium)chloride (16-E2-16 and 16-E3-16) and conventional surfactant (CTAC) in aqueous solutions have been studied by surface tension measurement of binary mixtures (0.0- 0.5 wt% NaCMC and 1 mM gemini surfactant/10 mM CTAC solution). Surface tension measurements were used to determine critical aggregation concentration (CAC) and critical micelle concentration (CMC). The maximum surface excess concentration (Ґmax) at the air-water interface was evaluated by the Gibbs adsorption equation. The minimum area per surfactant molecule was evaluated, which indicates the surfactant-polymer Interaction in a mixed system. The effect of changing surfactant chain length on CAC and CMC values of mixed polymer-surfactant systems was examined. From the results, it was found that the gemini surfactant interacts strongly with NaCMC as compared to its corresponding monomeric counterpart CTAC. In these systems, electrostatic interactions predominate. The lowering of surface tension with an increase in the concentration of surfactants is higher in the case of gemini surfactants almost 10-15 times. The measurements indicated that the Interaction between NaCMC-CTAC resulted in complex formation. The volume of coacervate increases with an increase in CTAC concentration; however, above 0.1 wt. % concentration coacervate vanishes.

Keywords: anionic polymer, gemni surfactants, tensiometer, CMC, interaction

Procedia PDF Downloads 77

Authors: Mostafa Amirjan

Abstract:

In the present study, the properties of Al-Al2O3 nanocomposite hollow sphere structures were investigated. For this reason, the Al-based nanocomposite hollow spheres with different amounts of nano alumina reinforcement (0-10wt %) and different ratio of thickness to diameter (t/D: 0.06-0.3) were prepared via a powder metallurgy method. Then, the effect of mentioned parameters was studied on physical and quasi static mechanical properties of their related prepared structures (open/closed cell) such as density, hardness, strength and energy absorption. It was found that as the t/D ratio increases the relative density, compressive strength and energy absorption increase. The highest values of strength and energy absorption were obtained from the specimen with 5 wt. % of nanoparticle reinforcement, t/D of 0.3 (t=1 mm, D=400µm) as 22.88 MPa and 13.24 MJ/m3, respectively. The moderate specific strength of prepared composites in the present study showed the good consistency with the properties of others low carbon steel composite with similar structure.

Keywords: hollow sphere structure foam, nanocomposite, thickness and diameter (t/D ), powder metallurgy

Procedia PDF Downloads 442