Search results for: boundary element method

Authors: Rishikesh Dingari, Sai Kiran Dornala

Abstract:

In this paper, a simple method of achieving maximum power by mechanical energy transmission device (METD) with integration to induction generator is proposed. METD functioning is explained and dynamic response of system to step input is plotted. Induction generator is being operated at self-excited mode with excitation capacitor at stator. Voltage and current are observed when linked to METD.

Keywords: mechanical energy transmitting device(METD), self-excited induction generator, wind turbine, hydraulic actuators

Procedia PDF Downloads 333

Authors: Haoxiang Desmond Lim, Jie Wu, Tze How Daniel New, Shengxian Shi

Abstract:

This paper outlines the development of a novel experimental technique in quantifying supersonic jet flows, in an attempt to avoid seeding particle problems frequently associated with particle-image velocimetry (PIV) techniques at high Mach numbers. Based on optical flow algorithms, the idea behind the technique involves using high speed cameras to capture Schlieren images of the supersonic jet shear layers, before they are subjected to an adapted optical flow algorithm based on the Horn-Schnuck method to determine the associated flow fields. The proposed method is capable of offering full-field unsteady flow information with potentially higher accuracy and resolution than existing point-measurements or PIV techniques. Preliminary study via numerical simulations of a circular de Laval jet nozzle successfully reveals flow and shock structures typically associated with supersonic jet flows, which serve as useful data for subsequent validation of the optical flow based experimental results. For experimental technique, a Z-type Schlieren setup is proposed with supersonic jet operated in cold mode, stagnation pressure of 8.2 bar and exit velocity of Mach 1.5. High-speed single-frame or double-frame cameras are used to capture successive Schlieren images. As implementation of optical flow technique to supersonic flows remains rare, the current focus revolves around methodology validation through synthetic images. The results of validation test offers valuable insight into how the optical flow algorithm can be further improved to improve robustness and accuracy. Details of the methodology employed and challenges faced will be further elaborated in the final conference paper should the abstract be accepted. Despite these challenges however, this novel supersonic flow measurement technique may potentially offer a simpler way to identify and quantify the fine spatial structures within the shock shear layer.

Keywords: Schlieren, optical flow, supersonic jets, shock shear layer

Procedia PDF Downloads 303

Authors: Engy A. Mohamed, Y. G. Hegazy

Abstract:

This paper presents a novel algorithm for modeling photovoltaic based distributed generators for the purpose of optimal planning of distribution networks. The proposed algorithm utilizes sequential Monte Carlo method in order to accurately consider the stochastic nature of photovoltaic based distributed generators. The proposed algorithm is implemented in MATLAB environment and the results obtained are presented and discussed.

Keywords: comulative distribution function, distributed generation, Monte Carlo

Procedia PDF Downloads 570

Authors: Wang Yichen, Haruka Yamashita

Abstract:

In recent years, in the field of sports, decision making such as member in the game and strategy of the game based on then analysis of the accumulated sports data are widely attempted. In fact, in the NBA basketball league where the world's highest level players gather, to win the games, teams analyze the data using various statistical techniques. However, it is difficult to analyze the game data for each play such as the ball tracking or motion of the players in the game, because the situation of the game changes rapidly, and the structure of the data should be complicated. Therefore, it is considered that the analysis method for real time game play data is proposed. In this research, we propose an analytical model for "determining the optimal lineup composition" using the real time play data, which is considered to be difficult for all coaches. In this study, because replacing the entire lineup is too complicated, and the actual question for the replacement of players is "whether or not the lineup should be changed", and “whether or not Small Ball lineup is adopted”. Therefore, we propose an analytical model for the optimal player selection problem based on Small Ball lineups. In basketball, we can accumulate scoring data for each play, which indicates a player's contribution to the game, and the scoring data can be considered as a time series data. In order to compare the importance of players in different situations and lineups, we combine RNN (Recurrent Neural Network) model, which can analyze time series data, and NN (Neural Network) model, which can analyze the situation on the field, to build the prediction model of score. This model is capable to identify the current optimal lineup for different situations. In this research, we collected all the data of accumulated data of NBA from 2019-2020. Then we apply the method to the actual basketball play data to verify the reliability of the proposed model.

Keywords: recurrent neural network, players lineup, basketball data, decision making model

Procedia PDF Downloads 116

Authors: Floyd Misheck Mwanza, Paul Boniface Majura

Abstract:

The paper looked at highways/ roadside waste generation, disposal and the consequent environmental impacts. The dramatic increase in vehicular and paved roads in the recent past in Zambia, has given rise to the indiscriminate disposal of litter that now poses a threat to health and the environment. Primary data was generated by carrying out oral interviews and field observations for holistic and in–depth assessment of the environment and the secondary data was obtained from desk review method, information on effects of roadside wastes on environment were obtained from relevant literatures. The interviews were semi structured and a purposive sampling method was adopted and analyzed descriptively. The results of the findings showed that population growth and unplanned road expansion has exceeded the expected limit in recent time with resultant poor system of roadside wastes disposal. Roadside wastes which contain both biodegradable and non-biodegradable roadside wastes are disposed at the shoulders of major highways in temporary dumpsites and are never collected by a road development agency (RDA). There is no organized highway to highway or street to street collection of the wastes in Zambia by the key organization the RDA. The study revealed that roadside disposal of roadside wastes has serious impacts on the environment. Some of these impacts include physical nuisance of the wastes to the environment, the waste dumps also serve as hideouts for rodents and snakes which are dangerous. Waste are blown around by wind making the environment filthy, most of the wastes are also been washed by overland flow during heavy downpour to block drainage channels and subsequently lead to flooding of the environment. Most of the non- biodegradable wastes contain toxic chemicals which have serious implications on the environmental sustainability and human health. The paper therefore recommends that Government/ RDA should come up with proper orientation and environmental laws should be put in place for the general public and also to provide necessary facilities and arrange for better methods of collection of wastes.

Keywords: biodegradable, disposal, environment, impacts

Procedia PDF Downloads 326

Authors: R. Fardid, R. Coppes

Abstract:

Introduction: In mediastinal radiotherapy and to a lesser extend also in total-body irradiation (TBI) radiation exposure may lead to development of cardiac diseases. Radiation-induced heart disease is dose-dependent and it is characterized by a loss of cardiac function, associated with progressive heart cells degeneration. We aimed to determine the in-vivo radiation effects on fibronectin, ColaA1, ColaA2, galectin and TGFb1 gene expression levels in left ventricle heart tissues of rats after irradiation. Material and method: Four non-treatment adult Wistar rats as control group (group A) were selected. In group B, 4 adult Wistar rats irradiated to 20 Gy single dose of 150 Mev proton beam locally in heart only. In heart plus lung irradiate group (group C) 4 adult rats was irradiated by 50% of lung laterally plus heart radiation that mentioned in before group. At 8 weeks after radiation animals sacrificed and left ventricle heart dropped in liquid nitrogen for RNA extraction by Absolutely RNA® Miniprep Kit (Stratagen, Cat no. 400800). cDNA was synthesized using M-MLV reverse transcriptase (Life Technologies, Cat no. 28025-013). We used Bio-Rad machine (Bio Rad iQ5 Real Time PCR) for QPCR testing by relative standard curve method. Results: We found that gene expression of fibronectin in group C significantly increased compared to control group, but it was not showed significant change in group B compared to group A. The levels of gene expressions of Cola1 and Cola2 in mRNA did not show any significant changes between normal and radiation groups. Changes of expression of galectin target significantly increased only in group C compared to group A. TGFb1 expressions in group C more than group B showed significant enhancement compared to group A. Conclusion: In summary we can say that 20 Gy of proton exposure of heart tissue may lead to detectable damages in heart cells and may distribute function of them as a component of heart tissue structure in molecular level.

Keywords: gene expression, heart damage, proton irradiation, radiotherapy

Procedia PDF Downloads 478

Authors: V. P. Muhamed Shajudheen, K. Viswanathan, K. Anitha Rani, A. Uma Maheswari, S. Saravana Kumar

Abstract:

In this paper, a simple chemical precipitation route for the preparation of titanium dioxide nanoparticles, synthesized by using titanium tetra isopropoxide as a precursor and polyvinyl pyrrolidone (PVP) as a capping agent, is reported. The Differential Scanning Calorimetry (DSC) and Thermo Gravimetric Analysis (TGA) of the samples were recorded and the phase transformation temperature of titanium hydroxide, Ti(OH)₄ to titanium oxide, TiO₂ was investigated. The as-prepared Ti(OH)₄ precipitate was annealed at 800°C to obtain TiO₂ nanoparticles. The thermal, structural, morphological and textural characterizations of the TiO₂ nanoparticle samples were carried out by different techniques such as DSC-TGA, X-Ray Diffraction (XRD), Fourier Transform Infra-Red spectroscopy (FTIR), Micro Raman spectroscopy, UV-Visible absorption spectroscopy (UV-Vis), Photoluminescence spectroscopy (PL) and Field Effect Scanning Electron Microscopy (FESEM) techniques. The as-prepared precipitate was characterized using DSC-TGA and confirmed the mass loss of around 30%. XRD results exhibited no diffraction peaks attributable to anatase phase, for the reaction products, after the solvent removal. The results indicate that the product is purely rutile. The vibrational frequencies of two main absorption bands of prepared samples are discussed from the results of the FTIR analysis. The formation of nanosphere of diameter of the order of 10 nm, has been confirmed by FESEM. The optical band gap was found by using UV-Visible spectrum. From photoluminescence spectra, a strong emission was observed. The obtained results suggest that this method provides a simple, efficient and versatile technique for preparing TiO₂ nanoparticles and it has the potential to be applied to other systems for photocatalytic activity.

Keywords: TiO2 nanoparticles, chemical precipitation route, phase transition, Fourier Transform Infra-Red spectroscopy (FTIR), micro-Raman spectroscopy, UV-Visible absorption spectroscopy (UV-Vis), Photoluminescence Spectroscopy (PL) and Field Effect Scanning electron microscopy (FESEM)

Procedia PDF Downloads 308

Authors: Vardan Melkonyan, Arman Azizyan, Astghik Boyajyan

Abstract:

Virtual reality (VR) exposure therapy is a form of cognitive-behavioral therapy that uses immersive virtual environments to expose individuals to the feared stimuli or situations that trigger their phobia. VR exposure therapy has become an increasingly popular treatment for phobias, including fear of heights, public speaking, and flying, due to its ability to provide a controlled and safe environment for individuals to confront their fears while also allowing therapists to tailor the virtual exposure to the specific needs and goals of each individual. It is also a cost-effective and accessible treatment option, as it can be delivered remotely and does not require the use of drugs. Overall, VR exposure therapy has the potential to be a valuable tool for therapists in the treatment of phobias. But current methods may be improved by incorporating advanced technology such as photorealistic VR environments, tactile feedback suits, and responsive systems. The aim of this study was to identify the most effective approach for enhancing VR exposure therapy for the treatment of phobias. Photorealistic VR environments and stimuli can greatly enhance the effectiveness of VR exposure therapy for the treatment of phobias. By creating immersive, realistic virtual environments that closely mimic the real-life situations that trigger phobia responses, patients are able to more fully engage in the therapeutic process and confront their fears in a controlled and safe manner. This can help to reduce the severity of phobia symptoms and increase treatment outcomes. The use of tactile feedback suits and responsive systems can further enhance the VR exposure therapy experience by adding a physical element to the virtual environment. These suits, which can mimic the sensations of touch, pressure, and movement, allow patients to fully immerse themselves in the virtual world and feel as if they are physically present in the situation. This can help to increase the realism of the virtual environment and make it more effective in reducing phobia symptoms. Additionally, responsive systems can be used to trigger specific events or responses within the virtual environment based on the patient's actions, providing a more interactive and personalized treatment experience. A comprehensive literature review was conducted, including studies on VR exposure therapy for phobias and the use of advanced technology to enhance the therapy. Results indicate that incorporating these enhancements may significantly increase the effectiveness of VR exposure therapy for phobias. Further research is needed to fully understand the potential of these enhancements and to determine the optimal combination and implementation.

Keywords: virtual reality, mental health, phobias, fears, treatment, photorealistic, immersive, phobia

Procedia PDF Downloads 75

Authors: A. Kachmazova, A. Shadiev, Y. Teterin, P. Yartcev

Abstract:

Introduction: Biliary calculi disease (LCS) still occupies the leading position among urgent diseases of the abdominal cavity, manifesting itself from asymptomatic course to life-threatening states. Nowadays arsenal of diagnostic methods for choledocholithiasis is quite wide: ultrasound, hepatobiliscintigraphy (HBSG), magnetic resonance imaging (MRI), endoscopic retrograde cholangiography (ERCP). Among them, transabdominal ultrasound (TA ultrasound) is the most accessible and routine diagnostic method. Nowadays ERCG is the "gold" standard in diagnosis and one-stage treatment of biliary tract obstruction. However, transpapillary techniques are accompanied by serious postoperative complications (postmanipulative pancreatitis (3-5%), endoscopic papillosphincterotomy bleeding (2%), cholangitis (1%)), the lethality being 0.4%. GBSG and MRI are also quite informative methods in the diagnosis of choledocholithiasis. Small size of concrements, their localization in intrapancreatic and retroduodenal part of common bile duct significantly reduces informativity of all diagnostic methods described above, that demands additional studying of this problem. Materials and Methods: 890 patients with the diagnosis of cholelithiasis (calculous cholecystitis) were admitted to the Sklifosovsky Scientific Research Institute of Hospital Medicine in the period from August, 2020 to June, 2021. Of them 115 people with mechanical jaundice caused by concrements in bile ducts. Results: Final EUS diagnosis was made in all patients (100,0%). In all patients in whom choledocholithiasis diagnosis was revealed or confirmed after EUS, ERCP was performed urgently (within two days from the moment of its detection) as the X-ray operation room was provided; it confirmed the presence of concrements. All stones were removed by lithoextraction using Dormia basket. The postoperative period in these patients had no complications. Conclusions: EUS is the most informative and safe diagnostic method, which allows to detect choledocholithiasis in patients with discrepancies between clinical-laboratory and instrumental methods of diagnosis in shortest time, that in its turn will help to decide promptly on the further tactics of patient treatment. We consider it reasonable to include EUS in the diagnostic algorithm for choledocholithiasis. Disclosure: Nothing to disclose.

Keywords: endoscopic ultrasonography, choledocholithiasis, common bile duct, concrement, ERCP

Procedia PDF Downloads 73

Authors: Fariba Dortaj, Reza Asadinejad, Akram Dortaj, Atena Baziyar

Abstract:

The aim of this study was to determine the effect of distance education (based on MOOC) on the components of academic engagement of Kerman PNU. The research was quasi-experimental method that cluster sampling with an appropriate volume was used in this study (one class in experimental group and one class in controlling group). Sampling method is single-stage cluster sampling. The statistical society is students of Kerman Payam Noor University, which) were selected 40 of them as sample (20 students in the control group and 20 students in experimental group). To test the hypothesis, it was used the analysis of univariate and Co-covariance to offset the initial difference (difference of control) in the experimental group and the control group. The instrument used in this study is academic engagement questionnaire of Zerang (2012) that contains component of cognitive, behavioral and motivational engagement. The results showed that there is no significant difference between mean scores of academic components of academic engagement in experimental group and the control group on the post-test, after elimination of the pre-test. The adjusted mean scores of components of academic engagement in the experimental group were higher than the adjusted average of scores after the test in the control group. The use of technology-based education in distance education has been effective in increasing cognitive engagement, motivational engagement and behavioral engagement among students. Experimental variable with the effect size 0.26, predicted 26% of cognitive engagement component variance. Experimental variable with the effect size 0.47, predicted 47% of the motivational engagement component variance. Experimental variable with the effect size 0.40, predicted 40% of behavioral engagement component variance. So teaching with technology (MOOC) has a positive impact on increasing academic engagement and academic performance of students in educational technology. The results suggest that technology (MOOC) is used to enrich the teaching of other lessons of PNU.

Keywords: educational technology, distance education, components of academic engagement, mooc technology

Procedia PDF Downloads 135

Authors: Kiana Zeighami, Morteza Ozlati Moghadam

Abstract:

Designing a high accuracy and high precision motion controller is one of the important issues in today’s industry. There are effective solutions available in the industry but the real-time performance, smoothness and accuracy of the movement can be further improved. This paper discusses a complete solution to carry out the movement of three stepper motors in three dimensions. The objective is to provide a method to design a fully integrated System-on-Chip (SOC)-based motion controller to reduce the cost and complexity of production by incorporating Field Programmable Gate Array (FPGA) into the design. In the proposed method the FPGA receives its commands from a host computer via wireless internet communication and calculates the motion trajectory for three axes. A profile generator module is designed to realize the interpolation algorithm by translating the position data to the real-time pulses. This paper discusses an approach to implement the linear interpolation algorithm, since it is one of the fundamentals of robots’ movements and it is highly applicable in motion control industries. Along with full profile trajectory, the triangular drive is implemented to eliminate the existence of error at small distances. To integrate the parallelism and real-time performance of FPGA with the power of Central Processing Unit (CPU) in executing complex and sequential algorithms, the NIOS II soft-core processor was added into the design. This paper presents different operating modes such as absolute, relative positioning, reset and velocity modes to fulfill the user requirements. The proposed approach was evaluated by designing a custom-made FPGA board along with a mechanical structure. As a result, a precise and smooth movement of stepper motors was observed which proved the effectiveness of this approach.

Keywords: 3-axis linear interpolation, FPGA, motion controller, micro-stepping

Procedia PDF Downloads 196

Authors: Michal Brazda, Miroslav Urbanek, Martina Koukolikova

Abstract:

This work focuses on the development of functional surfaces and edges for cutting and forming tools created through the Directed Energy Deposition (DED) technology. In the context of growing challenges in modern engineering, additive technologies, especially DED, present an innovative approach to manufacturing tools for forming and cutting. One of the key features of DED is its ability to precisely and efficiently deposit Fully dense metals from powder feedstock, enabling the creation of complex geometries and optimized designs. Gradually, it becomes an increasingly attractive choice for tool production due to its ability to achieve high precision while simultaneously minimizing waste and material costs. Tools created using DED technology gain significant durability through the utilization of high-performance materials such as nickel alloys and tool steels. For high-temperature applications, Nimonic 80A alloy is applied, while for cold applications, M2 tool steel is used. The addition of ceramic materials, such as tungsten carbide, can significantly increase the tool's resistance. The introduction of functionally graded materials is a significant contribution, opening up new possibilities for gradual changes in the mechanical properties of the tool and optimizing its performance in different sections according to specific requirements. In this work, you will find an overview of individual applications and their utilization in the industry. Microstructural analyses have been conducted, providing detailed insights into the structure of individual components alongside examinations of the mechanical properties and tool life. These analyses offer a deeper understanding of the efficiency and reliability of the created tools, which is a key element for successful development in the field of cutting and forming tools. The production of functional surfaces and edges using DED technology can result in financial savings, as the entire tool doesn't have to be manufactured from expensive special alloys. The tool can be made from common steel, onto which a functional surface from special materials can be applied. Additionally, it allows for tool repairs after wear and tear, eliminating the need for producing a new part and contributing to an overall cost while reducing the environmental footprint. Overall, the combination of DED technology, functionally graded materials, and verified technologies collectively set a new standard for innovative and efficient development of cutting and forming tools in the modern industrial environment.

Keywords: additive manufacturing, directed energy deposition, DED, laser, cutting tools, forming tools, steel, nickel alloy

Procedia PDF Downloads 34

Authors: Chia-Jung Chang, Sheng-Che Chen, Ming-Long Yeh, Chih-Wei Wang, Chih-Han Chang

Abstract:

Introduction and Motivation: In recent years, magnesium alloy is used to be a kind of medical biodegradable materials. Magnesium is an essential element in the body and is efficiently excreted by the kidneys. Furthermore, the mechanical properties of magnesium alloy is closest to human bone. However, in some cases magnesium alloy corrodes so quickly that it would release hydrogen on surface of implant. The other product is hydroxide ion, it can significantly increase the local pH value. The above situations may have adverse effects on local cell functions. On the other hand, nowadays magnesium alloy corrode too fast to maintain the function of implant until the healing of tissue. Therefore, much recent research about magnesium alloy has focused on controlling the corrosion rate. The in vitro corrosion behavior of magnesium alloys is affected by many factors, and pH value is one of factors. In this study, we will study on the influence of pH value on the corrosion behavior of magnesium alloy by the Micro-CT (micro computed tomography) and other instruments.Material and methods: In the first step, we make some guiding plates for specimens of magnesium alloy AZ91 by Rapid Prototyping. The guiding plates are able to be a standard for the degradation of specimen, so that we can use it to make sure the position of specimens in the CT image. We can also simplify the conditions of degradation by the guiding plates.In the next step, we prepare the solution with different pH value. And then we put the specimens into the solution to start the corrosion test. The CT image, surface photographs and weigh are measured on every twelve hours. Results: In the primary results of the test, we make sure that CT image can be a way to quantify the corrosion behavior of magnesium alloy. Moreover we can observe the phenomenon that corrosion always start from some erosion point. It’s possibly based on some defect like dislocations and the voids with high strain energy in the materials. We will deal with the raw data into Mass Loss (ML) and corrosion rate by CT image, surface photographs and weigh in the near future. Having a simple prediction, the pH value and degradation rate will be negatively correlated. And we want to find out the equation of the pH value and corrosion rate. We also have a simple test to simulate the change of the pH value in the local region. In this test the pH value will rise to 10 in a short time. Conclusion: As a biodegradable implant for the area with stagnating body fluid flow in the human body, magnesium alloy can cause the increase of local pH values and release the hydrogen. Those may damage the human cell. The purpose of this study is finding out the equation of the pH value and corrosion rate. After that we will try to find the ways to overcome the limitations of medical magnesium alloy.

Keywords: magnesium alloy, biodegradable materials, corrosion, micro-CT

Procedia PDF Downloads 443

Authors: Brahim Boukabcha, Amar Rebbouh

Abstract:

The bootstrap method based on the idea of exploiting all the information provided by the initial sample, allows us to study the properties of estimators. In this article we will present a theoretical study on the different methods of bootstrapping and using the technique of re-sampling in statistics inference to calculate the standard error of means of an estimator and determining a confidence interval for an estimated parameter. We apply these methods tested in the regression models and Pareto model, giving the best approximations.

Keywords: bootstrap, error standard, bias, jackknife, mean, median, variance, confidence interval, regression models

Procedia PDF Downloads 370

Authors: Montree Bunruanses, Preecha Yupapin

Abstract:

In this work, the quantum material called Amrita (elixir) is made from top-down gold into nanometer particles by fusing 99% gold with a laser and mixing it with drinking water using the atmospheric water (AWG) production system, which is made of water with air. The high energy laser power destroyed the four natural force bindings from gravity-weak-electromagnetic and strong coupling forces, where finally it was the purified Bose-Einstein condensate (BEC) states. With this method, gold atoms in the form of spherical single crystals with a diameter of 30-50 nanometers are obtained and used. They were modulated (activated) with a frequency generator into various matrix structures mixed with AWG water to be used in the upstream conversion (quantum reversible) process, which can be applied on humans both internally or externally by drinking or applying on the treated surfaces. Doing both space (body) and time (mind) will go back to the origin and start again from the coupling of space-time on both sides of time at fusion (strong coupling force) and push out (Big Bang) at the equilibrium point (singularity) occurs as strings and DNA with neutrinos as coupling energy. There is no distortion (purification), which is the point where time and space have not yet been determined, and there is infinite energy. Therefore, the upstream conversion is performed. It is reforming DNA to make it be purified. The use of Amrita is a method used for people who cannot meditate (quantum meditation). Various cases were applied, where the results show that the Amrita can make the body and the mind return to their pure origins and begin the downstream process with the Big Bang movement, quantum communication in all dimensions, DNA reformation, frequency filtering, crystal body forming, broadband quantum communication networks, black hole forming, quantum consciousness, body and mind healing, etc.

Keywords: quantum materials, quantum meditation, quantum reversible, Bose-Einstein condensate

Procedia PDF Downloads 55

Authors: Pushpa Debnath

Abstract:

Buddhism implies the ultimate methodology to obtain the acknowledgment to get out from cycling existence applied by the sutras. The Buddha’s natural methodology is the highest way of cessation from suffering existence. To be out of it, one must know the suffering before having tentativeness. According to the Buddha’s methodology, one can observe every being suffer from chronologically grasping craving. It is because lack of knowledge that the Buddha finds the four noble truths which are the basic states. These are suffering, the origin of suffering, cessation of suffering, and the path leading to the cessation of suffering. The Buddha describes that birth is suffering, aging is suffering, sickness is suffering, death is suffering, association with the unexpected is suffering, separation from the pleasant is suffering, and not receiving what one desires is suffering, In brief, the five aggregates of clinging are suffering. As the five aggregates are form, feeling, perception, mental formation, and consciousness. These are known as the matter that we identify with “You, Me” or “He.” The second truth cause of suffering is craving which has three types: craving for sense pleasures, craving for existence, and craving for non-existence. The third truth is the obliteration of craving, suffering can be eliminated to attain the Nibbana. The fourth truth is the path of liberation is the noble eight-fold path consisting of the right view, right intention, right speech, right action, right livelihood, right effort, right mindfulness, and right concentration. The six senses are the media of the eye, ear, nose, tongue, body, and mind sense faculties relating with the five aggregates and the six senses objects visual objects, sounds, smells, tastes, touch, and mind-objects that are contained by every visible being. The first five internal sense bases are material while the mind is a non-material phenomenon. Contact with the external world maintains by receiving through the six senses; visual objects through the eye, sounds through the ear, smells through the nose, tastes through the tongue, touch through the body, and mind-objects through sense faculties. These are the six senses a living being experiences by craving. Everything is conglomerated with all senses faculties through the natural phenomenon which are earth, water, fire, and air element. In this analysis, it is believed that beings are well adapted to the natural phenomenon. Everybody has fear of life because we have hatred, delusion, and anger which are the primary resources of falling into (Samsara) continuously that is the continuity of the natural way. These are the reasons for the suffering that chronically self-diluting through the threefold way. These are the roots of the entire beings suffering so the Buddha finds the enlightenment to uproot from cycling existence and the understanding of the natural consequence. When one could uproot ignorance, one could able to realize the ultimate happiness of Nirvana. From the craving of ignorance, everything starts to be present to the future which gives us mental agonies in existence.

Keywords: purification, morality, natural phenomenon, analysis, development of mind, observatory, Nirvana

Procedia PDF Downloads 68

Authors: Belal Bakheet, John Beardall, Xiwang Zhang, David McCarthy

Abstract:

The potential risks associated with toxic cyanobacteria have raised growing environmental and public health concerns leading to an increasing effort into researching ways to bring about their removal from water, together with destruction of their associated cyanotoxins. A variety of toxins are synthesized by cyanobacteria and include hepatotoxins, neurotoxins, and cytotoxins which can cause a range of symptoms in humans from skin irritation to serious liver and nerve damage. Therefore drinking water treatment processes should ensure the consumers’ safety by removing both cyanobacterial cells, and cyanotoxins from the water. Cyanobacterial cells and cyanotoxins presented challenges to the conventional water treatment systems; their accumulation within drinking water treatment plants has been reported leading to plants shut down. Thus, innovative and effective water purification systems to tackle cyanobacterial pollution are required. In recent years there has been increasing attention to the electrochemical oxidation process as a feasible alternative disinfection method which is able to generate in situ a variety of oxidants that would achieve synergistic effects in the water disinfection process and toxin degradation. By utilizing only electric current, the electrochemical process through electrolysis can produce reactive oxygen species such as hydroxyl radicals from the water, or other oxidants such as chlorine from chloride ions present in the water. From extensive physiological and morphological investigation of cyanobacterial cells during electrolysis, our results show that these oxidants have significant impact on cell inactivation, simultaneously with cyanotoxins removal without the need for chemicals addition. Our research aimed to optimize existing electrochemical oxidation systems and develop new systems to treat water containing toxic cyanobacteria and cyanotoxins. The research covers detailed mechanism study on oxidants production and cell inactivation in the treatment under environmental conditions. Overall, our study suggests that the electrochemical treatment process e is an effective method for removal of toxic cyanobacteria and cyanotoxins.

Keywords: toxic cyanobacteria, cyanotoxins, electrochemical process, oxidants

Procedia PDF Downloads 216

Authors: Enya Trenholm-Jensen

Abstract:

This paper employs various semiotic methodologies to examine the mechanism of soft power. Soft power refers to a country’s global reputation and their ability to leverage that reputation to achieve certain aims. South Korea has invested heavily in their soft power strategy for a multitude of predominantly historical and geopolitical reasons. On account of this investment and the global prominence of their strategy, South Korea was considered to be the optimal candidate for the aims of this investigation. Having isolated the entertainment industry as one of the most heavily funded segments of the South Korean soft power strategy, the analysis restricted itself to this sector. Within this industry, two entertainment products were selected as case studies. The case studies were chosen based on commercial success according to metrics such as streams, purchases, and subsequent revenue. This criterion was deemed to be the most objective and verifiable indicator of the products general appeal. The entertainment products which met the chosen criterion were Netflix’ “Squid Game” and BTS’ hit single “Butter”. The methodologies employed were chosen according to the medium of the entertainment products. For “Squid Game,” an aesthetic analysis was carried out to investigate how multi- layered meanings were mobilized in a show popularized by its visual grammar. To examine “Butter”, both music semiology and linguistic analysis were employed. The music section featured an analysis underpinned by denotative and connotative music semiotic theories borrowing from scholars Theo van Leeuwen and Martin Irvine. The linguistic analysis focused on stance and semantic fields according to scholarship by George Yule and John W. DuBois. The aesthetic analysis of the first case study revealed intertextual references to famous artworks, which served to augment the emotional provocation of the Squid Game narrative. For the second case study, the findings exposed a set of musical meaning units arranged in a patchwork of familiar and futuristic elements to achieve a song that existed on the boundary between old and new. The linguistic analysis of the song’s lyrics found a deceptively innocuous surface level meaning that bore implications for authority, intimacy, and commercial success. Whether through means of visual metaphor, embedded auditory associations, or linguistic subtext, the collective findings of the three analyses exhibited a desire to conjure a form of positive arousal in the spectator. In the synthesis section, this process is likened to that of branding. Through an exploration of branding, the entertainment products can be understood as cogs in a larger operation aiming to create positive associations to Korea as a country and a concept. Limitations in the form of a timeframe biased perspective are addressed, and directions for future research are suggested. This paper employs semiotic methodologies to examine two entertainment products as mechanisms of soft power. Through means of visual metaphor, embedded auditory associations, or linguistic subtext, the findings reveal a desire to conjure positive arousal in the spectator. The synthesis finds similarities to branding, thus positioning the entertainment products as cogs in a larger operation aiming to create positive associations to Korea as a country and a concept.

Keywords: BTS, cognitive semiotics, entertainment, soft power, south korea, squid game

Procedia PDF Downloads 134

Authors: E. Nakamachi, K. Matsumoto, K. Yamamoto, Y. Morita, H. Sakamoto

Abstract:

In recently, electromagnetic and mechanical stimulations have been recognized as the effective extracellular environment stimulation technique to enhance the defected peripheral nerve tissue regeneration. In this study, we developed a new hybrid bioreactor by adopting 50 Hz uniform alternative current (AC) magnetic stimulation and 4% strain mechanical stimulation. The guide tube for nerve regeneration is mesh structured tube made of biodegradable polymer, such as polylatic acid (PLA). However, when neural damage is large, there is a possibility that peripheral nerve undergoes necrosis. So it is quite important to accelerate the nerve tissue regeneration by achieving enhancement of nerve axonal extension rate. Therefore, we try to design and fabricate the system that can simultaneously load the uniform AC magnetic field stimulation and the stretch stimulation to cells for enhancement of nerve axonal extension. Next, we evaluated systems performance and the effectiveness of each stimulation for rat adrenal pheochromocytoma cells (PC12). First, we designed and fabricated the uniform AC magnetic field system and the stretch stimulation system. For the AC magnetic stimulation system, we focused on the use of pole piece structure to carry out in-situ microscopic observation. We designed an optimum pole piece structure using the magnetic field finite element analyses and the response surface methodology. We fabricated the uniform AC magnetic field stimulation system as a bio-reactor by adopting analytically determined design specifications. We measured magnetic flux density that is generated by the uniform AC magnetic field stimulation system. We confirmed that measurement values show good agreement with analytical results, where the uniform magnetic field was observed. Second, we fabricated the cyclic stretch stimulation device under the conditions of particular strains, where the chamber was made of polyoxymethylene (POM). We measured strains in the PC12 cell culture region to confirm the uniform strain. We found slightly different values from the target strain. Finally, we concluded that these differences were allowable in this mechanical stimulation system. We evaluated the effectiveness of each stimulation to enhance the nerve axonal extension using PC12. We confirmed that the average axonal extension length of PC12 under the uniform AC magnetic stimulation was increased by 16 % at 96 h in our bio-reactor. We could not confirm that the axonal extension enhancement under the stretch stimulation condition, where we found the exfoliating of cells. Further, the hybrid stimulation enhanced the axonal extension. Because the magnetic stimulation inhibits the exfoliating of cells. Finally, we concluded that the enhancement of PC12 axonal extension is due to the magnetic stimulation rather than the mechanical stimulation. Finally, we confirmed that the effectiveness of the uniform AC magnetic field stimulation for the nerve axonal extension using PC12 cells.

Keywords: nerve cell PC12, axonal extension, nerve regeneration, electromagnetic-mechanical stimulation, bioreactor

Procedia PDF Downloads 256

Authors: Yasser R. Tawfic, Mohamed A. Eid

Abstract:

Foundation differential settlement and supported structure tilting is an occasionally occurred engineering problem. This may be caused by overloading, changes in ground soil properties or unsupported nearby excavations. Engineering thinking points directly toward the logic solution for such problem by uplifting the settled side. This can be achieved with deep foundation elements such as micro-piles and macro-piles™, jacked piers and helical piers, jet grouted soil-crete columns, compaction grout columns, cement grouting or with chemical grouting, or traditional pit underpinning with concrete and mortar. Although, some of these techniques offer economic, fast and low noise solutions, many of them are quite the contrary. For tilted structures, with limited inclination, it may be much easier to cause a balancing settlement on the less-settlement side which shall be done carefully in a proper rate. This principal has been applied in Leaning Tower of Pisa stabilization with soil extraction from the ground surface. In this research, the authors attempt to introduce a new solution with a different point of view. So, micro-tunneling technique is presented in here as an intended ground deformation cause. In general, micro-tunneling is expected to induce limited ground deformations. Thus, the researchers propose to apply the technique to form small size ground unsupported holes to produce the target deformations. This shall be done in four phases: •Application of one or more micro-tunnels, regarding the existing differential settlement value, under the raised side of the tilted structure. •For each individual tunnel, the lining shall be pulled out from both sides (from jacking and receiving shafts) in slow rate. •If required, according to calculations and site records, an additional surface load can be applied on the raised foundation side. •Finally, a strengthening soil grouting shall be applied for stabilization after adjustment. A finite element based numerical model is presented to simulate the proposed construction phases for different tunneling positions and tunnels group. For each case, the surface settlements are calculated and induced plasticity points are checked. These results show the impact of the suggested procedure on the tilted structure and its feasibility. Comparing results also show the importance of the position selection and tunnels group gradual effect. Thus, a new engineering solution is presented to one of the structural and geotechnical engineering challenges.

Keywords: differential settlement, micro-tunneling, soil-structure interaction, tilted structures

Procedia PDF Downloads 195

Authors: Anette Alén

Abstract:

Intellectual property (IP) regimes have traditionally been designed to integrate various conflicting elements stemming from private entitlement and the public good. In IP laws and regulations, this design takes the form of specific uses of protected subject-matter without the right-holder’s consent, or exhaustion of exclusive rights upon market release, and the like. More recently, the pursuit of ‘balance’ has gained ground in the conceptualization of these conflicting elements both in terms of IP law and related policy. This can be seen, for example, in European Union (EU) copyright regime, where ‘balance’ has become a key element in argumentation, backed up by fundamental rights reasoning. This development also entails an ever-expanding dialogue between the IP regime and the constitutional safeguards for property, free speech, and privacy, among others. This study analyses the concept of ‘balance’ in EU copyright law: the research task is to examine the contents of the concept of ‘balance’ and the way it is operationalized and pursued, thereby producing new knowledge on the role and manifestations of ‘balance’ in recent copyright case law and regulatory instruments in the EU. The study discusses two particular pieces of legislation, the EU Digital Single Market (DSM) Copyright Directive (EU) 2019/790 and the finalized EU Artificial Intelligence (AI) Act, including some of the key preparatory materials, as well as EU Court of Justice (CJEU) case law pertaining to copyright in the digital era. The material is examined by means of document analysis, mapping the ways ‘balance’ is approached and conceptualized in the documents. Similarly, the interaction of fundamental rights as part of the balancing act is also analyzed. Doctrinal study of law is also employed in the analysis of legal sources. This study suggests that the pursuit of balance is, for its part, conducive to new battles, largely due to the advancement of digitalization and more recent developments in artificial intelligence. Indeed, the ‘balancing act’ rather presents itself as a way to bypass or even solidify some of the conflicting interests in a complex global digital economy. Indeed, such a conceptualization, especially when accompanied by non-critical or strategically driven fundamental rights argumentation, runs counter to the genuine acknowledgment of new types of conflicting interests in the copyright regime. Therefore, a more radical approach, including critical analysis of the normative basis and fundamental rights implications of the concept of ‘balance’, is required to readjust copyright law and regulations for the digital era. Notwithstanding the focus on executing the study in the context of the EU copyright regime, the results bear wider significance for the digital economy, especially due to the platform liability regime in the DSM Directive and with the AI Act including objectives of a ‘level playing field’ whereby compliance with EU copyright rules seems to be expected among system providers.

Keywords: balance, copyright, fundamental rights, platform liability, artificial intelligence

Procedia PDF Downloads 19

Authors: Vishal Raj, Noorhan Abbas

Abstract:

Ambiguity in NLP (Natural language processing) refers to the ability of a word, phrase, sentence, or text to have multiple meanings. This results in various kinds of ambiguities such as lexical, syntactic, semantic, anaphoric and referential am-biguities. This study is focused mainly on solving the issue of Lexical ambiguity. Word Sense Disambiguation (WSD) is an NLP technique that aims to resolve lexical ambiguity by determining the correct meaning of a word within a given context. Most WSD solutions rely on words for training and testing, but we have used lemma and Part of Speech (POS) tokens of words for training and testing. Lemma adds generality and POS adds properties of word into token. We have designed a novel method to create an affinity matrix to calculate the affinity be-tween any pair of lemma_POS (a token where lemma and POS of word are joined by underscore) of given training set. Additionally, we have devised an al-gorithm to create the sense clusters of tokens using affinity matrix under hierar-chy of POS of lemma. Furthermore, three different mechanisms to predict the sense of target word using the affinity/similarity value are devised. Each contex-tual token contributes to the sense of target word with some value and whichever sense gets higher value becomes the sense of target word. So, contextual tokens play a key role in creating sense clusters and predicting the sense of target word, hence, the model is named Contextual SenSe Model (CSM). CSM exhibits a noteworthy simplicity and explication lucidity in contrast to contemporary deep learning models characterized by intricacy, time-intensive processes, and chal-lenging explication. CSM is trained on SemCor training data and evaluated on SemEval test dataset. The results indicate that despite the naivety of the method, it achieves promising results when compared to the Most Frequent Sense (MFS) model.

Keywords: word sense disambiguation (wsd), contextual sense model (csm), most frequent sense (mfs), part of speech (pos), natural language processing (nlp), oov (out of vocabulary), lemma_pos (a token where lemma and pos of word are joined by underscore), information retrieval (ir), machine translation (mt)

Procedia PDF Downloads 88

Authors: Matthew D. Baffa

Abstract:

Infrared thermography is a non-destructive test method used to estimate surface temperatures based on the amount of electromagnetic energy radiated by building envelope components. These surface temperatures are indicators of various qualitative building envelope deficiencies such as locations and extent of heat loss, thermal bridging, damaged or missing thermal insulation, air leakage, and moisture presence in roof, floor, and wall assemblies. Although infrared thermography is commonly used for qualitative deficiency detection in buildings, this study assesses its use as a quantitative method to estimate the overall thermal conductance value (U-value) of the exterior above-grade walls of a study home. The overall U-value of exterior above-grade walls in a home provides useful insight into the energy consumption and thermal comfort of a home. Three methodologies from the literature were employed to estimate the overall U-value by equating conductive heat loss through the exterior above-grade walls to the sum of convective and radiant heat losses of the walls. Outdoor infrared thermography field measurements of the exterior above-grade wall surface and reflective temperatures and emissivity values for various components of the exterior above-grade wall assemblies were carried out during winter months at the study home using a basic thermal imager device. The overall U-values estimated from each methodology from the literature using the recorded field measurements were compared to the nominal exterior above-grade wall overall U-value calculated from materials and dimensions detailed in architectural drawings of the study home. The nominal overall U-value was validated through calendarization and weather normalization of utility bills for the study home as well as various estimated heat loss quantities from a HOT2000 computer model of the study home and other methods. Under ideal environmental conditions, the estimated overall U-values deviated from the nominal overall U-value between ±2% to ±33%. This study suggests infrared thermography can estimate the overall U-value of exterior above-grade walls in low-rise residential homes with a fair amount of accuracy.

Keywords: emissivity, heat loss, infrared thermography, thermal conductance

Procedia PDF Downloads 298

Authors: J. Jena, Monica Saxena

Abstract:

In this paper, the propagation of weak nonlinear waves in non-equilibrium flow has been studied in detail using the perturbation method. The expansive action of receding piston undergoing infinite acceleration has been discussed. Central expansion fan, compression waves and shock fronts have been discussed and the solutions up to the first order in the characteristic plane and physical plane have been obtained.

Keywords: Characteristic wave front, weak non-linear waves, central expansion fan, compression waves

Procedia PDF Downloads 353

Authors: Irna Malganova

Abstract:

The paper assessed the effectiveness of the use of urban functional zoning using the method of M.A. Kramer by the example of Kazan city (Republic of Tatarstan, Russian Federation) using geoinformation technologies. On the basis of the data obtained, the calculations were carried out to obtain data on population density, overcoming geographic determinism, as well as the effectiveness of the formation of urban frameworks. The authors proposed recommendations for the effectiveness of municipal frameworks in the period from 2018 to 2021: economic, social, environmental and social. The study of effective territorial planning in a given period allows to display of the dynamics of planning changes, as well as assessment of changes in the formation of urban frameworks. Based on the incoming data obtained from the master plan of the municipal formation of Kazan, in the period from 2018 to 2021, there was an increase in population by 13841 people or 1.1% of the values of 2018. In addition, the area of Kazan increased by 2419.6 hectares. In the structure of the distribution of areas of functional zones, there was an increase in such zones of the municipality as zones of residential and public purpose. Changes in functional zoning, as well as territories requiring reorganization, are presented using geoinformation technologies in open-source software Quantum Geographic Information System (QGIS 3.32). According to the calculations based on the method of functional zoning efficiency by M.A. Kreimer, the territorial-planning structure of Kazan City is quite effective. However, in the development of spatial planning concepts, it is possible to emphasize the weakened interest of the population in the development of territorial planning documents. Thus, the approach to spatial planning of Kazan differs from foreign methods and approaches based on the joint development of planning directions and development of territories of municipalities between the developers of the planning structure, business representatives and the population. The population plays the role of the target audience on which territorial planning is oriented. It follows that there is a need to satisfy the opinions and demands of the population.

Keywords: spatial development, metamorphosis, Kazan city, spatial planning, efficiency, geographic determinism., GIS, QGIS

Procedia PDF Downloads 65

Authors: Tuji Jemal Ahmed

Abstract:

Fresh produce is an essential component of a healthy diet. However, it can also be a potential source of pathogenic microorganisms that can cause foodborne illnesses. Traditional disinfection methods, such as washing with water and chlorine, have limitations and may not effectively remove or inactivate all microorganisms. This has led to the development of alternative/new methods of fresh produce disinfection, including physical and chemical methods. In this paper, we explore the physical and chemical new methods of fresh produce disinfection, their advantages and disadvantages, and their suitability for different types of produce. Physical methods of disinfection, such as ultraviolet (UV) radiation and high-pressure processing (HPP), are crucial in ensuring the microbiological safety of fresh produce. UV radiation uses short-wavelength UV-C light to damage the DNA and RNA of microorganisms, and HPP applies high levels of pressure to fresh produce to reduce the microbial load. These physical methods are highly effective in killing a wide range of microorganisms, including bacteria, viruses, and fungi. However, they may not penetrate deep enough into the product to kill all microorganisms and can alter the sensory characteristics of the product. Chemical methods of disinfection, such as acidic electrolyzed water (AEW), ozone, and peroxyacetic acid (PAA), are also important in ensuring the microbiological safety of fresh produce. AEW uses a low concentration of hypochlorous acid and a high concentration of hydrogen ions to inactivate microorganisms, ozone uses ozone gas to damage the cell membranes and DNA of microorganisms, and PAA uses a combination of hydrogen peroxide and acetic acid to inactivate microorganisms. These chemical methods are highly effective in killing a wide range of microorganisms, but they may cause discoloration or changes in the texture and flavor of some products and may require specialized equipment and trained personnel to produce and apply. In conclusion, the selection of the most suitable method of fresh produce disinfection should take into consideration the type of product, the level of microbial contamination, the effectiveness of the method in reducing the microbial load, and any potential negative impacts on the sensory characteristics, nutritional composition, and safety of the produce.

Keywords: fresh produce, pathogenic microorganisms, foodborne illnesses, disinfection methods

Procedia PDF Downloads 58

Authors: Sanjay Singh, Karunanithi Priyanka, Ramoji Kosuru, Raju Prasad Sharma

Abstract:

Herbal drugs are well known for their mixed pharmacological activities with the benefit of no harmful side effects. The use of herbal drugs is limited because of their higher dose requirement, frequent drug administration, poor bioavailability of phytochemicals and delayed onset of action. Ficus religiosa, a potent anti-oxidant plant useful in the treatment of diabetes and cancer was selected for the study. Solid lipid nanoparticles (SLN) of Ficus religiosa extract was developed for the enhancement in oral bioavailability of stigmasterol and β-sitosterol-d-glucoside, principal components present in the extract. Hot homogenization followed by ultrasonication method was used to develop extract loaded SLN. Developed extract loaded SLN were characterized for particle size, PDI, zeta potential, entrapment efficiency, in vitro drug release and kinetics, fourier transform infra-red spectroscopy, differential scanning calorimetry, powder X-ray diffractrometry and stability studies. Entrapment efficiency of optimized extract loaded SLN was found to be 68.46 % (56.13 % of stigmasterol and 12.33 % of β-sitosteryl-d-glucoside, respectively). RP HPLC method development was done for simultaneous estimation of stigmasterol and β-sitosterol-d-glucoside in Ficus religiosa extract in rat plasma. Bioavailability studies were carried out for extract in suspension form and optimized extract loaded SLN. AUC of stigmasterol and β-sitosterol-d-glucoside were increased by 6.7-folds by 9.2-folds, respectively in rats treated with extract loaded SLN compared to extract suspension. Also, Cmax of stigmasterol and β-sitosterol-d-glucoside were increased by 4.3-folds by 3.9-folds, respectively in rats treated with extract loaded SLN compared to extract suspension. Mean residence times (MRT) for stigmasterol were found to be 12.3 ± 0.67 hours from extract and 7.4 ± 2.1 hours from SLN and for β-sitosterol-d-glucoside, 10.49 ± 2.9 hours from extract and 6.4 ± 0.3 hours from SLN. Hence, it was concluded that SLN enhanced the bioavailability and reduced the MRT of stigmasterol and β-sitosterol-d-glucoside in Ficus religiosa extract which in turn may lead to reduction in dose of Ficus religiosa extract, prolonged duration of action and also enhanced therapeutic efficacy.

Keywords: Ficus religiosa, phytosterolins, bioavailability, solid lipid nanoparticles, stigmasterol and β-sitosteryl-d-glucoside

Procedia PDF Downloads 458

Authors: N. Ben Si Ali, N. Benalia, N. Zarzouri

Abstract:

Speed sensorless systems are intensively studied during recent years; this is mainly due to their economical benefit and fragility of mechanical sensors and also the difficulty of installing this type of sensor in many applications. These systems suffer from instability problems and sensitivity to parameter mismatch at low speed operation. In this paper an analysis of adaptive observer stability with stator resistance estimation is given.

Keywords: motor drive, sensorless control, adaptive observer, stator resistance estimation

Procedia PDF Downloads 360

Authors: M. El Hajji, A. Hallaoui, L. Bazzi, A. Benlhachemi, O. Jbara, A. Tara, B. Bakiz, L. Bazzi, M. Hilali

Abstract:

The objective of this study was the development of zinc-copper binary oxide "Cu2O-ZnO" thin films by the electrochemical method "cathodic electrodeposition" and their uses for the degradation of a basic dye "Congo Red" by direct anodic oxidation. The anode materials synthesized were characterized by X-ray diffraction "XRD" and by scanning electron microscopy "SEM" coupled to EDS.

Keywords: Cu2O-ZnO thin films, cathodic electrodeposition, electrodegradation, Congo Red, BDD

Procedia PDF Downloads 338

Authors: Yasaman Samani, Ali Golmohammadi

Abstract:

Introduction: The degree of conversion and depth of cure affects the clinical success of resin composite restorations directly. One of the main challenges in achieving a successful composite restoration is the achievement of sufficient depth of cure. The insufficient polymerization may lead to a decrease in the physical/mechanical and biological properties of resin composites and, as a result of that, unsuccessful composite restoration. Thus, because of the importance of studying and evaluating the depth of cure and degree of conversion in bulk-fill composites, we decided to evaluate and compare the degree of conversion and depth of cure in two bulk-fill composites; x-tra fill (Voco, Germany) and Opus Bulk fill APS (FGM, Brazil). Materials and Methods: Composite resin specimens (n=10) per group were prepared as cylinder blocks (4×8 mm) with bulk-fill composites, x-tra fil (Voco, Germany) designated as Group A, and Opus Bulk fill APS (FGM, Brazil) designated as Group B. Depth of cure was determined according to “ISO 4049; Depth of Cure” method, In which each specimen were cured (iLED, Woodpecker, China) 40 seconds and FTIR spectroscopy method was used to estimate the degree of conversion of both the bulk-fill composites. The degree of conversion of monomer to polymer was estimated individually in the coronal half (Group A1 and B1) and pulpal half (Group A2 and Group B2) by dividing each specimen into two halves. The data were analyzed using a Student’s t-test and one-way ANOVA at a 5% level of significance. Results: The mean depth of cure in x-tra fil (Voco, Germany) was 3.99 (±0.16), and for Opus Bulk fill, APS (FGM, Brazil) was 2.14 (±0.3). The degree of conversion percentage in Group A1 was 82.7 (±6.1), in group A2 was 73.4 (±5.2), in group B1 was 63.3 (±4.7) and in Group B2 was 56.5 (±7.7). Statistical analysis revealed a significant difference in the depth of cure between the two bulk-fill composites with x-tra fil (Voco, Germany) higher than Opus Bulk fill APS (FGM, Brazil) (P<0.001). The degree of conversion percentage also showed a significant difference, Group A1 being higher than A2 (P=0.0085), B1, and B2 (P<0.001). Group A2 was also higher than B1 (P=0.003) and B2 (P<0.001). There was no significant difference between B1 and B2 (P=0.072). Conclusion: The results indicate that x-tra fill has more depth of cure and a higher percentage of the degree of conversion than Opus Bulk fill APS. The coronal half of x-tra fil had the highest depth of cure percentage (82.66%), and the pulpal half of Opus Bulk fill APS had the lowest percentage (56.45%). Even though both bulk-fill composite materials had an acceptable degree of conversion (55% and higher), x-tra fill has shown better results.

Keywords: depth of cure, degree of conversion, bulk-fill composite, FTIR

Procedia PDF Downloads 90