Search results for: Landolt Ring experiment
3103 A Generalization of the Secret Sharing Scheme Codes Over Certain Ring
Authors: Ibrahim Özbek, Erdoğan Mehmet Özkan
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In this study, we generalize (k,n) threshold secret sharing scheme on the study Ozbek and Siap to the codes over the ring Fq+ αFq. In this way, it is mentioned that the method obtained in that article can also be used on codes over rings, and new advantages to be obtained. The method of securely sharing the key in cryptography, which Shamir first systematized and Massey carried over to codes, became usable for all error-correcting codes. The firewall of this scheme is based on the hardness of the syndrome decoding problem. Also, an open study area is left for those working for other rings and code classes. All codes that correct errors with this method have been the working area of this method.Keywords: secret sharing scheme, linear codes, algebra, finite rings
Procedia PDF Downloads 743102 Use Process Ring-Opening Polymerization to Melt Processing of Cellulose Nanowhisker from Coconut Husk Fibers-Filled Polylactide-Based Nanocomposites
Authors: Imam Wierawansyah Eltara, Iftitah, Agus Ismail
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In the present work, cellulose nanowhiskers (CNW) extracted from coconut husk fibers, were incorporated in polylactide (PLA)-based composites. Prior to the blending, PLA chains were chemically grafted on the surface of CNW to enhance the compatibilization between CNW and the hydrophobic polyester matrix. Ring-opening polymerization of L-lactide was initiated from the hydroxyl groups available at the CNW surface to yield CNW-g-PLA nanohybrids. PLA-based nanocomposites were prepared by melt blending to ensure a green concept of the study thereby limiting the use of organic solvents. The influence of PLA-grafted cellulose nanoparticles on the mechanical and thermal properties of the ensuing nanocomposites was deeply investigated. The thermal behavior and mechanical properties of the nanocomposites were determined using differential scanning calorimetry (DSC) and dynamical mechanical and thermal analysis (DMTA), respectively. In theory, evidenced that the chemical grafting of CNW enhances their compatibility with the polymeric matrix and thus improves the final properties of the nanocomposites. Large modification of the crystalline properties such as the crystallization half-time was evidenced according to the nature of the PLA matrix and the content of nanofillers.Keywords: cellulose nanowhiskers, nanocomposites, coconut husk fiber, ring opening polymerization
Procedia PDF Downloads 3173101 Substrate Coupling in Millimeter Wave Frequencies
Authors: Vasileios Gerakis, Fontounasios Christos, Alkis Hatzopoulos
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A study of the impact of metal guard rings on the coupling between two square metal pads is presented. The structure is designed over a bulk silicon substrate with epitaxial layer, so the coupling through the substrate is also involved. A lightly doped profile is adopted and is simulated by means of an electromagnetic simulator for various pad distances and different metal layers, assuming a 65 nm bulk CMOS technology. The impact of various guard ring design (geometrical) parameters is examined. Furthermore, the increase of isolation (resulting in reduction of the noise coupling) between the pads by cutting the ring, or by using multiple rings, is also analyzed. S parameters are used to compare the various structures.Keywords: guard rings, metal pad coupling, millimeter wave frequencies, substrate noise,
Procedia PDF Downloads 5393100 Mini-Open Repair Using Ring Forceps Show Similar Results to Repair Using Achillon Device in Acute Achilles Tendon Rupture
Authors: Chul Hyun Park
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Background:Repair using the Achillon deviceis a representative mini-open repair technique;however, the limitations of this technique includethe need for special instruments and decreasedrepair strength.A modifiedmini-open repair using ring forcepsmight overcome these limitations. Purpose:This study was performed to compare the Achillon device with ring forceps in mini-open repairsof acute Achilles tendon rupture. Study Design:This was a retrospective cohort study, and the level of evidence was3. Methods:Fifty patients (41 men and 9 women), withacute Achilles tendon rupture on one foot, were consecutively treated using mini-open repair techniques. The first 20 patients were treated using the Achillon device (Achillon group) and the subsequent 30 patients were treated using a ring forceps (Forcep group). Clinical, functional, and isokinetic results,and postoperative complications were compared between the two groups at the last follow-up. Clinical evaluations wereperformed using the American Orthopedic Foot and Ankle Society (AOFAS) score, Achilles tendon Total Rupture Score (ATRS), length of incision, and operation time. Functional evaluationsincludedactive range of motion (ROM) of the ankle joint, maximum calf circumference (MCC), hopping test, and single limb heel-rise (SLHR) test. Isokinetic evaluations were performed using the isokinetic test for ankle plantar flexion. Results:The AOFAS score (p=0.669), ATRS (p=0.753), and length of incision (p=0.305) were not significantly different between the groups. Operative times in the Achillon group were significantly shorter than that in the Forcep group (p<0.001).The maximum height of SLHR (p=0.023) and number of SLHRs (p=0.045) in the Forcep group were significantly greater than that in the Achillon group. No significant differences in the mean peak torques for plantar flexion at angular speeds of 30°/s (p=0.219) and 120°/s (p=0.656) were detected between the groups. There was no significant difference in the occurrence of postoperative complications between the groups (p=0.093). Conclusion:The ring forceps technique is comparable with the Achillon technique with respect to clinical, functional, and isokinetic results and the postoperative complications. Given that no special instrument is required, the ring forceps technique could be a better option for acute Achilles tendon rupture repair.Keywords: achilles tendon, acute rupture, repair, mini-open
Procedia PDF Downloads 813099 Full-Wave Analysis of Magnetic Meta-Surfaces for Microwave Component Applications
Authors: Christopher Hardly Joseph, Nicola Pelagalli, Davide Mencarelli, Luca Pierantoni
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In this contribution, we report the electromagnetic response of a split ring resonator (SRR) based magnetic metamaterial unit cell in free space nature by means of a full-wave electromagnetic simulation. The effective parameters of these designed structures have been analyzed. The structures have been specifically designed to work at high frequency considering the development of many microwave and lower mm-wave devices. In addition to that, the application of the designed metamaterial structures is also proposed, namely metamaterial loaded planar transmission lines, potentially useful to optimize size and quality factor of circuit components and radiating elements.Keywords: CPW, Microwave Components, Negative Permeability, Split Ring Resonator (SRR)
Procedia PDF Downloads 1793098 A Further Study on the 4-Ordered Property of Some Chordal Ring Networks
Authors: Shin-Shin Kao, Hsiu-Chunj Pan
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Given a graph G. A cycle of G is a sequence of vertices of G such that the first and the last vertices are the same. A hamiltonian cycle of G is a cycle containing all vertices of G. The graph G is k-ordered (resp. k-ordered hamiltonian) if for any sequence of k distinct vertices of G, there exists a cycle (resp. hamiltonian cycle) in G containing these k vertices in the specified order. Obviously, any cycle in a graph is 1-ordered, 2-ordered and 3-ordered. Thus the study of any graph being k-ordered (resp. k-ordered hamiltonian) always starts with k = 4. Most studies about this topic work on graphs with no real applications. To our knowledge, the chordal ring families were the first one utilized as the underlying topology in interconnection networks and shown to be 4-ordered [1]. Furthermore, based on computer experimental results in [1], it was conjectured that some of them are 4-ordered hamiltonian. In this paper, we intend to give some possible directions in proving the conjecture.Keywords: Hamiltonian cycle, 4-ordered, Chordal rings, 3-regular
Procedia PDF Downloads 4343097 Synthesis and Use of Bio Polyols in Rigid Polyurethane Foam Production
Authors: A. Esra Pişkin, L. Yusuf Yivlik
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Polyurethane consumption in the world increases every year. Polyetherpolyol, which is the main raw material of polyurethane, is produced from petroleum, and bioresources are needed in polyol production due to the damage it causes to the environment and the consumption of too much energy during the production phase. In this present work, bio polyol was synthesized with castor oil and soybean oil, and its use in rigid polyurethane systems was investigated. Transesterification and ring opening methods were applied for polyol synthesis, and the obtained bio polyols were compared with polyols derived petroleum. The goal of the present study was to synthesize biopolyols and to investigate the mechanical, thermal, and chemical properties of the synthesized polyurethane in terms of bio polyols.Keywords: polyurethane, polyol, biopolyol, vegetable oil, foam, rigid polyurethane foam, ring opening, transesterification
Procedia PDF Downloads 4653096 A Study on Ideals and Prime Ideals of Sub-Distributive Semirings and Its Applications to Symmetric Fuzzy Numbers
Authors: Rosy Joseph
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From an algebraic point of view, Semirings provide the most natural generalization of group theory and ring theory. In the absence of additive inverse in a semiring, one had to impose a weaker condition on the semiring, i.e., the additive cancellative law to study interesting structural properties. In many practical situations, fuzzy numbers are used to model imprecise observations derived from uncertain measurements or linguistic assessments. In this connection, a special class of fuzzy numbers whose shape is symmetric with respect to a vertical line called the symmetric fuzzy numbers i.e., for α ∈ (0, 1] the α − cuts will have a constant mid-point and the upper end of the interval will be a non-increasing function of α, the lower end will be the image of this function, is suitable. Based on this description, arithmetic operations and a ranking technique to order the symmetric fuzzy numbers were dealt with in detail. Wherein it was observed that the structure of the class of symmetric fuzzy numbers forms a commutative semigroup with cancellative property. Also, it forms a multiplicative monoid satisfying sub-distributive property.In this paper, we introduce the algebraic structure, sub-distributive semiring and discuss its various properties viz., ideals and prime ideals of sub-distributive semiring, sub-distributive ring of difference etc. in detail. Symmetric fuzzy numbers are visualized as an illustration.Keywords: semirings, subdistributive ring of difference, subdistributive semiring, symmetric fuzzy numbers
Procedia PDF Downloads 2123095 A Low Cost and Reconfigurable Experimental Platform for Engineering Lab Education
Authors: S. S. Kenny Lee, C. C. Kong, S. K. Ting
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Teaching engineering lab provides opportunity for students to practice theories learned through physical experiment in the laboratory. However, building laboratories to accommodate increased number of students are expensive, making it impossible for an educational institution to afford the high expenses. In this paper, we develop a low cost and remote platform to aid teaching undergraduate students. The platform is constructed where the real experiment setting up in laboratory can be reconfigure and accessed remotely, the aim is to increase student’s desire to learn at which they can interact with the physical experiment using network enabled devices at anywhere in the campus. The platform is constructed with Raspberry Pi as a main control board that provides communication between computer interfaces to the actual experiment preset in the laboratory. The interface allows real-time remote viewing and triggering the physical experiment in the laboratory and also provides instructions and learning guide about the experimental.Keywords: engineering lab, low cost, network, remote platform, reconfigure, real-time
Procedia PDF Downloads 3083094 Management of Tibial Bone Defects Following Grade Three Injury in Adults
Authors: Rajendra Kumar Kanojia
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Background; Massive bone gaps are common following road side accidents and injury to the tibia, specially open grade three fractures. It has been seen that the diaphyseal fractures in the tibia are prone to non-union, there are certain reasons known very well, like less soft tissues around the lower third tibia, less vascularity, less options of fixation of the fractures after trauma and prolonged surgical time, operation theatre time and special surgical means. Aim of study; To know the suitability of the ilizarov ring fixators in staged treatment of the fracture of the both bones leg, including tibia, we wish to see the role of ilizarov in management of open grade three fractures which have been operated and debrided, for getting the length use of ilizaorv ring in a tertiary canter is the aim of the study.Keywords: open fracture, staged management, ilizarov, bone grafting, lengthening
Procedia PDF Downloads 3063093 A Comparative Analysis of a Custom Optimization Experiment with Confidence Intervals in Anylogic and Optquest
Authors: Felipe Haro, Soheila Antar
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This paper introduces a custom optimization experiment developed in AnyLogic, based on genetic algorithms, designed to ensure reliable optimization results by incorporating Montecarlo simulations and achieving a specified confidence level. To validate the custom experiment, we compared its performance with AnyLogic's built-in OptQuest optimization method across three distinct problems. Statistical analyses, including Welch's t-test, were conducted to assess the differences in performance. The results demonstrate that while the custom experiment shows advantages in certain scenarios, both methods perform comparably in others, confirming the custom approach as a reliable and effective tool for optimization under uncertainty.Keywords: optimization, confidence intervals, Montecarlo simulation, optQuest, AnyLogic
Procedia PDF Downloads 173092 Failure to Replicate the Unconscious Thought Advantages
Authors: Vladimíra Čavojová, Eva Ballová Mikušková
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In this study we tried to replicate the unconscious thought advantage (UTA), which states that complex decisions are better handled by unconscious thinking. We designed an experiment in e-prime using similar material as the original study (choosing between four different apartments, each described by 12 attributes). A total of 73 participants (52 women (71.2%); 18 to 62 age: M=24.63; SD=8.7) took part in the experiment. We did not replicate the results suggested by UTT. However, from the present study we cannot conclude whether this was the case of flaws in the theory or flaws in our experiment and we discuss several ways in which the issue of UTA could be examined further.Keywords: decision making, unconscious thoughts, UTT, complex decisions
Procedia PDF Downloads 3073091 Modelling of Damage as Hinges in Segmented Tunnels
Authors: Gelacio JuáRez-Luna, Daniel Enrique GonzáLez-RamíRez, Enrique Tenorio-Montero
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Frame elements coupled with springs elements are used for modelling the development of hinges in segmented tunnels, the spring elements modelled the rotational, transversal and axial failure. These spring elements are equipped with constitutive models to include independently the moment, shear force and axial force, respectively. These constitutive models are formulated based on damage mechanics and experimental test reported in the literature review. The mesh of the segmented tunnels was discretized in the software GID, and the nonlinear analyses were carried out in the finite element software ANSYS. These analyses provide the capacity curve of the primary and secondary lining of a segmented tunnel. Two numerical examples of segmented tunnels show the capability of the spring elements to release energy by the development of hinges. The first example is a segmental concrete lining discretized with frame elements loaded until hinges occurred in the lining. The second example is a tunnel with primary and secondary lining, discretized with a double ring frame model. The outer ring simulates the segmental concrete lining and the inner ring simulates the secondary cast-in-place concrete lining. Spring elements also modelled the joints between the segments in the circumferential direction and the ring joints, which connect parallel adjacent rings. The computed load vs displacement curves are congruent with numerical and experimental results reported in the literature review. It is shown that the modelling of a tunnel with primary and secondary lining with frame elements and springs provides reasonable results and save computational cost, comparing with 2D or 3D models equipped with smeared crack models.Keywords: damage, hinges, lining, tunnel
Procedia PDF Downloads 3903090 Overview of Fiber Optic Gyroscopes
Authors: M. Abdo, Ahmed Elghandour, Khairy Eltahlawy, Mohamed Shalaby
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A key development in the field of inertial sensors, fiber-optic gyroscopes (FOGs) are currently thought to be a competitive alternative to mechanical gyroscopes for inertial navigation and control applications. For the past few years, research and development efforts have been conducted all around the world using the FOG as a crucial sensor for high-accuracy inertial navigation systems. The main fundamentals of optical gyros were covered in this essay, followed by discussions of the main types of optical gyros—fiber optic gyroscopes and ring laser gyroscopes—and comparisons between them. We also discussed different types of fiber optic gyros, including interferometric, resonator, and brillion fiber optic gyroscopes.Keywords: mechanical gyros, ring laser gyros, interferometric fiber optic gyros, resonator fiber optic gyros
Procedia PDF Downloads 853089 Synthesis of Epoxidized Castor Oil Using a Sulphonated Polystyrene Type Cation Exchange Resin and Its Blend Preparation with Epoxy Resin
Authors: G. S. Sudha, Smita Mohanty, S. K. Nayak
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Epoxidized oils can replace petroleum derived materials in numerous industrial applications, because of their respectable oxirane oxygen content and high reactivity of oxirane ring. Epoxidized castor oil (ECO) has synthesized in the presence of a sulphonated polystyrene type cation exchange resin. The formation of the oxirane ring was confirmed by Fourier Transform Infrared Spectroscopy (FTIR) analysis. The epoxidation reaction was evaluated by Nuclear Magnetic Resonance (NMR) studies. ECO is used as a toughening phase to increase the toughness of petroleum-based epoxy resin.Keywords: epoxy resin, epoxidized castor oil, sulphonated polystyrene type cation exchange resin, petroleum derived materials
Procedia PDF Downloads 4743088 Research on the Effect of Coal Ash Slag Structure Evolution on Its Flow Behavior During Co-gasification of Coal and Indirect Coal Liquefaction Residue
Authors: Linmin Zhang
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Entrained-flow gasification technology is considered the most promising gasification technology because of its clean and efficient utilization characteristics. The stable fluidity of slag at high temperatures is the key to affecting the long-period operation of the gasifier. The diversity and differences of coal ash-slag systems make it difficult to meet the requirements for stable slagging in entrained-flow gasifiers. Therefore, coal blending or adding fluxes has been used in industry for a long time to improve the flow behavior of coal ash. As a by-product of the indirect coal liquefaction process, indirect coal liquefaction residue (ICLR) is a kind of industrial solid waste that is usually disposed of by stacking or landfilling. However, this disposal method will not only occupy land resources but also cause serious pollution to soil and water bodies by leachate containing toxic and harmful metals. As a carbon-containing matrix, ICLR is not only a kind of waste but also a kind of energy substance. Utilizing existing industrial gasifiers to blend combustion ICLR can not only transform industrial solid waste into fuel but also save coal resources. Moreover, the ICLR usually contains a unique ash chemical composition different from coal, which will affect the slagging performance of the gasifier. Therefore, exploring the effect of the ash addition in ICLR on the coal ash flow behavior can not only improve the slagging performance and gasification efficiency of entrained-flow gasifier by using the unique ash chemical composition of ICLR but also provide some theoretical support for the large-scale consumption of industrial solid waste. Combining molecular dynamics simulation with Raman spectroscopy experiment, the effect of ICLR addition on slag structure and fluidity was explained, and the relationship between the evolution law of slag short/medium range microstructure and macroscopic flow behavior was discussed. The research found that the high silicon and aluminum content in coal ash led to the formation of complex [SiO₄]⁴- tetrahedron and [AlO₄]⁵- tetrahedron structures at high temperature, and the [SiO₄]⁴- tetrahedron and [AlO₄]⁵- tetrahedron were connected by oxygen atoms to form a multi-membered ring structure with high polymerization degree. Due to the action of the multi-membered ring structure, the internal friction in the slag increased, and the viscosity value was higher on the macro-level. As a network-modified ion, Fe2+ could replace Si4+ and Al3+ in the multi-membered ring structure and combine with O2-, which will destroy the bridge oxygen (BO) structure and transform more complex tri cluster oxygen (TO) and bridge oxygen (BO) into simple non-bridge oxygen (NBO) structure. As a result, a large number of multi-membered rings with high polymerization degrees were depolymerized into low-membered rings with low polymerization degrees. The evolution of oxygen types and ring structures in slag reduced the structure complexity and polymerization degree of coal ash slag, resulting in a decrease in the viscosity of coal ash slag.Keywords: ash slag, coal gasification, fluidity, industrial solid waste, slag structure
Procedia PDF Downloads 293087 Numerical Investigation of Fluid Flow, Characteristics of Thermal Performance and Enhancement of Heat Transfer of Corrugated Pipes with Various Geometrical Configurations
Authors: Ahmed Ramadhan Al-Obaidi, Jassim Alhamid
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In this investigation, the flow pattern, characteristics of thermal-hydraulic, and improvement of heat transfer performance are evaluated using a numerical technique in three dimensions corrugated pipe heat exchanger. The modification was made under different corrugated pipe geometrical parameters, including corrugated ring angle (CRA), distance between corrugated ring (DBCR), and corrugated diameter (CD), the range of Re number from 2000 to 12000. The numerical results are validated with available experimental data. The numerical outcomes reveal that there is an important change in flow field behaviour and a significant increase in friction factor and improvement in heat transfer performance owing to the use of the corrugated shape in the heat exchanger pipe as compared to the conventional smooth pipe. Using corrugated pipe with different configurations makes the flow more turbulence, flow separation, boundary layer distribution, flow mixing, and that leads to augmenting the performance of heat transfer. Moreover, the value of pressure drop, and the Nusselt number increases as the corrugated pipe geometrical parameters increase. Furthermore, the corrugation configuration shapes have an important influence on the thermal evaluation performance factor, and the maximum value was more than 1.3. Numerical simulation can be performed to predict the various geometrical configurations effects on fluid flow, thermal performance, and heat transfer enhancement.Keywords: corrugated ring angle, corrugated diameter, Nusselt number, heat transfer
Procedia PDF Downloads 1433086 Voltage Controlled Ring Oscillator for RF Applications in 0.18 µm CMOS Technology
Authors: Mohammad Arif Sobhan Bhuiyan, Zainal Abidin Nordin, Mamun Bin Ibne Reaz
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A compact and power efficient high performance Voltage Controlled Oscillator (VCO) is a must in analog and digital circuits especially in the communication system, but the best trade-off among the performance parameters is a challenge for researchers. In this paper, a design of a compact 3-stage differential voltage controlled ring oscillator (VCRO) with low phase noise, low power and higher tuning bandwidth is proposed in 0.18 µm CMOS technology. The VCRO is designed with symmetric load and positive feedback techniques to achieve higher gain and minimum delay. The proposed VCRO can operate at tuning range of 3.9-5.0 GHz at 1.6 V supply voltage. The circuit consumes only 1.0757 mW of power and produces -129 dbc/Hz. The total active area of the proposed VCRO is only 11.74 x 37.73 µm2. Such a VCO can be the best choice for compact and low-power RF applications.Keywords: CMOS, VCO, VCRO, oscillator
Procedia PDF Downloads 4753085 In situ Ortho-Quinone Methide Reactions for Construction of Flavonoids with Fused Ring Systems
Authors: Vidia A. Nuraini, Eugene M. H. Yee, Mohan Bhadbhade, David StC. Black, Naresh Kumar
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Flavonoids are naturally occurring compounds that have been shown to exhibit a wide range of biological properties including anticancer and anti-inflammatory activities. However, flavonoids suffer from low bioavailability, which limits their overall utility for therapeutic applications. One of the methods to overcome this limitation is through structural modification of natural flavonoids. In this study, flavanone, isoflavanone, and isoflavene, were structurally modified through the introduction of additional fused-ring systems via ortho-quinone methide intermediates (o-QMs). These intermediates can readily undergo a [4+2] cycloaddition through an inverse-electron-demand Diels–Alder reaction with electron-rich dienophiles. A regioselective Mannich reaction using bis-(N,N-dimethylamino)methane was employed to generate the o-QM precursors of flavanone, isoflavanone, and isoflavene. The o-QM intermediates were subsequently generated in situ through thermal elimination of the dimethylamine functionality and reacted with a variety of dienophiles to produce novel flavonoids with fused-ring systems. A total of 21 novel flavonoid analogs were successfully synthesized. The X-ray crystal structure of cycloaddition adducts, particularly those derived from 3,4-dihydro-2H-pyran and p-methoxystyrene revealed a special case of enantiomeric disorder, where two enantiomers in equal amounts superpose with one another, with the exception for atoms that have opposite configuration. The anticancer properties of fused-ring systems derived from isoflavene were evaluated against the neuroblastoma SKN-BE(2)C, the triple negative breast cancer MDA-MB-231, and the glioblastoma U87 cancer cell lines. One of these cycloaddition adducts had displayed improved anti-proliferative activity against MDA-MB-231 and U87 cancer cell lines as compared to the parent compound. Further anticancer and anti-inflammatory activities of the flavanone and isoflavanone analogs are currently being investigated.Keywords: Diels-Alder reaction, flavonoids, Mannich reaction, ortho-quinone methide.
Procedia PDF Downloads 2513084 A Green Approach towards the Production of CaCO₃ Scaffolds for Bone Tissue Engineering
Authors: Sudhir Kumar Sharma, Abiy D. Woldetsadik, Mazin Magzoub, Ramesh Jagannathan
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It is well known that bioactive ceramics exhibit specific biological affinities, especially in the area of tissue re-generation. In this context, we report the development of an eminently scalable, novel, supercritical CO₂ based process for the fabrication of hierarchically porous 'soft' CaCO₃ scaffolds. Porosity at the macro, micro, and nanoscales was obtained through process optimization of the so-called 'coffee-ring effect'. Exposure of these CaCO₃ scaffolds to monocytic THP-1 cells yielded negligible levels of tumor necrosis factor-alpha (TNF-α) thereby confirming the lack of immunogenicity of the scaffolds. ECM protein treatment of the scaffolds showed enhanced adsorption comparable to standard control such as glass. In vitro studies using osteoblast precursor cell line, MC3T3, also demonstrated the cytocompatibility of hierarchical porous CaCO₃ scaffolds.Keywords: supercritical CO2, CaCO3 scaffolds, coffee-ring effect, ECM proteins
Procedia PDF Downloads 3033083 Pyrazolylpyrazolines: Design, Synthesis and Biological Evaluation as Dual Acting Antimalarial-Antileishmanial Agents
Authors: Adnan Bekhit, Eskedar Lodebo, Ariaya Hymete, Hanan Ragab, Alaa El-Din Bekhit
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Malaria and leishmaniasis have emerged as serious universal health problems throughout history of mankind. According to the WHO 2008 malarial report, half of the world population is at risk of malarial infection with an estimate of 1 million deaths occurring annually mainly in the African region. Furthermore, 12-15 million people are infected with Leishmaniasis worldwide. Despite the continuous introduction of a large number of agents for the treatment of malaria, there is still unmet medical needs due to the emergence of resistance. Resistance has occurred for almost all therapeutic agents approved for the treatment of malaria. Accordingly, it was the aim of this work to design and synthesis a group of antimalarial-antileshmanial agents that would show inhibitory activity against chloroquine-resistant strain of Plasmodium falciparum. The synthesized compounds were designed to contain a pyrazolylpyrazoline moiety having an aromatic group (p-tolyl or p-chlorophenyl) at N1-position of one pyrazoline ring due to the reports of promising activities of such compounds. A formyl or acyl substituent was introduced at the N1-position of the other pyrazoline ring, to investigate the effect of bulkiness of acyl substituents at this position. The synthesized compounds were evaluated for their in-vivo antimalarial activity against Plasmodium berghei infected mice at dose levels of 20 and 30 mg/Kg. the two most active compounds were evaluated for their antimalarial activity against chloroquin-resistant strain (RKL9) of Plasmodium falciparum. In addition, the synthesized compounds were tested for their in-vitro antileshmanial activity against Leishmania aethiopica promastigotes and amastigotes. For both antimalarial and antileishmanial activities, compounds having an N1-p-tolyl group at the first pyrazoline ring did not require bulkiness at the second pyrazoline ring nitrogen where the compound bearing an acetyl group proved to be the most active of the whole series. On the other hand, bulkiness at the N1-position of the second pyazoline ring was necessary in case of compounds carrying the p-chlorophenyl group, where the two derivatives having an N1-butanoyl and an N1-benzoyl moieties at the second pyrazoline showed the best activity. Furthermore, the toxicity of the active compounds were tested and were proved to be non-toxic at 125, 250 and 500 mg/Kg. In addition, docking of the most active compound (having a p-tolyl group at the first pyrazoline-N and an acetyl moiety on the other pyrazoline-N) was performed against dihydrofolate reductase enzyme.Keywords: pyrazoline derivatives, in-vivo antimalarial activity, docking, dihydrofolate reductase
Procedia PDF Downloads 3413082 Thermal Performance of Radial Heat Sinks for LED Applications
Authors: Jongchul Park, Chan Byon
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In this study, the thermal performance of radial heat sinks for LED applications is investigated numerically and experimentally. The effect of geometrical parameters such as inner radius, fin height, fin length, and fin spacing, as well as the Elenbaas number, is considered. In addition, the effects of augmentation of concentric ring, perforation, and duct are extensively explored in order to enhance the thermal performance of conventional radial heat sink. The results indicate that the Elenbaas number and the fin radius have a significant effect on the thermal performance of the heat sink. The concentric ring affects the performance much, but the degree of affection is highly dependent on the orientation. The perforation always brings about higher thermal performance. The duct can effectively prevent the bypass of the natural convection flow, which in turn reduces the thermal resistance of the radial heat sink significantly.Keywords: heat transfer, radial heat sink, LED, Elenbaas
Procedia PDF Downloads 4043081 Design, Synthesis and Anti-Inflammatory Activity of Some Coumarin and Flavone Derivatives Containing 1,4 Dioxane Ring System
Authors: Asif Husain, Shah Alam Khan
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Coumarins and flavones are oxygen containing heterocyclic compounds which are present in various biologically active compounds. Both the heterocyclic rings are associated with diverse biological actions, therefore considered as an important scaffold for the design of molecules of pharmaceutical interest. Aim: To synthesize and evaluate the in vivo anti-inflammatory activity of few coumrain and flavone derivatives containing 1,4 dioxane ring system. Materials and methods: Coumarin derivatives (3a-d) were synthesized by reacting 7,8 dihydroxy coumarin (2a) and its 4-methyl derivative (2b) with epichlorohydrin/ethylene dibromide. The flavone derivatives (10a-d) were prepared by using quercetin and 3,4 dihydroxy flavones. Compounds of both the series were also evaluated for their anti-inflammatory, analgesic activity and ulcerogenicity in animal models by reported methods. Results and Discussion: The structures of all newly synthesized compounds were confirmed with the help of IR, 1H NMR, 13C NMR and Mass spectral studies. Elemental analyses data for each element analyzed (C, H, N) was found to be within acceptable range of ±0.4 %. Flavone derivatives, but in particular quercetin containing 1,4 dioxane ring system (10d) showed better anti-inflammatory and analgesic activity along with reduced gastrointestinal toxicity as compared to other synthesized compounds. The results of anti-inflammatory and analgesic activities of both the series are comparable with the positive control, diclofenac. Conclusion: Compound 10d, a quercetin derivative, emerged as a lead molecule which exhibited potent anti-inflammatory and analgesic activity with significant reduced gastric toxicity.Keywords: analgesic, anti-inflammatory, 1, 4 dioxane, coumarin, flavone
Procedia PDF Downloads 3273080 Texture-Based Image Forensics from Video Frame
Authors: Li Zhou, Yanmei Fang
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With current technology, images and videos can be obtained more easily than ever. It is so easy to manipulate these digital multimedia information when obtained, and that the content or source of the image and video could be easily tampered. In this paper, we propose to identify the image and video frame by the texture-based approach, e.g. Markov Transition Probability (MTP), which is in space domain, DCT domain and DWT domain, respectively. In the experiment, image and video frame database is constructed, and is used to train and test the classifier Support Vector Machine (SVM). Experiment results show that the texture-based approach has good performance. In order to verify the experiment result, and testify the universality and robustness of algorithm, we build a random testing dataset, the random testing result is in keeping with above experiment.Keywords: multimedia forensics, video frame, LBP, MTP, SVM
Procedia PDF Downloads 4273079 Study of Complex (CO) 3Ti (PHND) and CpV (PHND) (PHND = Phénanthridine)
Authors: Akila Tayeb-Benmachiche, Saber-Mustapha Zendaoui, Salah-Eddine Bouaoud, Bachir Zouchoune
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The variation of the metal coordination site in π-coordinated polycyclic aromatic hydrocarbons (PAH) corresponds to the haptotropic rearrangement or haptotropic migration in which the metal fragment MLn is considered as the moveable moiety that is shifted between two rings of polycyclic or heteropolycyclic ligands. These structural characteristics and dynamical properties give to this category of transition metal complexes a considerable interest. We have investigated the coordination and the haptotropic shifts of (CO)3Ti and CpV moieties over the phenanthridine aromatic system and according to the metal atom nature. The optimization of (CO)3Ti(PHND) and CpV(PHND), using the Amsterdam Density Functional (ADF) program, without a symmetrical restriction of geometry gives an η6 coordination mode of the C6 and C5N rings, which in turn give rise to a six low-lying deficient 16-MVE of each (CO)3Ti(PHND) and CpV(PHND) structure (three singlet and three triplet state structures for Ti complexes and three triplet and three quintet state structures for V complexes). Thus, the η6–η6 haptotropic migration of the metal fragment MLn from the terminal C6 ring to the central C5N ring has been achieved by a loss of energy. However, its η6–η6 haptotropic migration from central C5N ring to the terminal C6 rings has been accomplished by a gain of energy. These results show the capability of the phenanthridine ligand to adapt itself to the electronic demand of the metal in agreement with the nature of the metal–ligand bonding and demonstrate that this theoretical study can also be applied to large fused π-systems.Keywords: electronic structure, bonding analysis, density functional theory, coordination chemistry haptotropic migration
Procedia PDF Downloads 3013078 The Metabolite Profiling of Fulvestrant-3 Boronic Acid under Biological Oxidation
Authors: Changde Zhang, Qiang Zhang, Shilong Zheng, Jiawang Liu, Shanchun Guo, Qiu Zhong, Guangdi Wang
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Fulvestrant was approved by FDA to treat breast cancer as a selective estrogen receptor downregulator (SERD) with intramuscular injection administration. ZB716, a fulvestarnt-3 boronic acid, is an SERD with comparable anticancer effect to fulvestrant, but could produce good pharmacokinetic properties under oral administration with mice or rat models. To understand why ZB716 produced much better oral bioavailability, it was proposed that the boronic acid blocked the phase II direct biotransformation with the hydroxyl group on the 3 position of the aromatic ring on fulvestrant. In this study, ZB716 or fulvestrant was incubated with human liver microsome and oxidation cofactor NADPH in vitro. Their metabolites after oxidation were profiled with the Q-Exactive, a high-resolution mass spectrometer. The result showed that ZB716 blocked the forming of hydroxyl groups on its benzene ring except for the oxidation of C-B bond forming fulvestrant in its metabolites, and the concentration of fulvestrant with one more hydroxyl group found in the metabolites from incubation with fulvestrant was about 34 fold high as that formed from incubation with ZB716. Compared to fulvestrant, ZB716 is expected to be much difficult to be further bio-transformed into more hydrophilic compounds, to be difficult excreted out of blood system, and to have longer residence time in blood, which can lead to higher oral bioavailability. This study provided evidence to explain the high bioavailability of ZB716 after oral administration from the perspective of its difficulty of oxidation, a phase I biotransformation, on positions on its aromatic ring.Keywords: biotransformation, fulvestrant, metabolite profiling, ZB716
Procedia PDF Downloads 2593077 A New Investigation Technique for Improvement of the Cullet for Pottery Glaze
Authors: Benchalak Muangmeesri
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This research is experiment glaze from use cullet that is broken decayed from the used such as, glass bottle, windshield , etc. For seek raw material compensation that is raw material of the glaze in ceramic. The objective of the research for study the ratio of the glaze that is appropriate for glaze ceramic products and evaluate the experiment glaze on the vitreous china. The experiment has limits in using ceramic process such as, using calculation formula with triaxial, the empirical formula’s of Seger, and formula calculation is the percentage of the compound. for choose formula has will the possibility for glaze on vitreous china. The experiments in 108 triaxial can choose best formula and calculate is be left just 6 a formula for the calculation. The calculation is the percentage of the raw materials. Find that, three formulas in six formula there is percentage amount of the raw material that is cullet has the amount the little more 10 percentages then repeated experiment just three formulas. Overall, this research have three formulas for used its and we get all processes achieved and well done.Keywords: cullet, glaze, pottery, ceramic
Procedia PDF Downloads 2713076 An Erudite Technique for Face Detection and Recognition Using Curvature Analysis
Authors: S. Jagadeesh Kumar
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Face detection and recognition is an authoritative technology for image database management, video surveillance, and human computer interface (HCI). Face recognition is a rapidly nascent method, which has been extensively discarded in forensics such as felonious identification, tenable entree, and custodial security. This paper recommends an erudite technique using curvature analysis (CA) that has less false positives incidence, operative in different light environments and confiscates the artifacts that are introduced during image acquisition by ring correction in polar coordinate (RCP) method. This technique affronts mean and median filtering technique to remove the artifacts but it works in polar coordinate during image acquisition. Investigational fallouts for face detection and recognition confirms decent recitation even in diagonal orientation and stance variation.Keywords: curvature analysis, ring correction in polar coordinate method, face detection, face recognition, human computer interaction
Procedia PDF Downloads 2863075 Passive Attenuation with Multiple Resonator Rings for Musical Instruments Equalization
Authors: Lorenzo Bonoldi, Gianluca Memoli, Abdelhalim Azbaid El Ouahabi
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In this paper, a series of ring-shaped attenuators utilizing Helmholtz and quarter wavelength resonators in variable, fixed, and combined configurations have been manufactured using a 3D printer. We illustrate possible uses by incorporating such devices into musical instruments (e.g. in acoustic guitar sound holes) and audio speakers with a view to controlling such devices tonal emissions without electronic equalization systems. Numerical investigations into the transmission loss values of these ring-shaped attenuators using finite element method simulations (COMSOL Multiphysics) have been presented in the frequency range of 100– 1000 Hz. We compare such results for each attenuator model with experimental measurements using different driving sources such as white noise, a maximum-length sequence (MLS), square and sine sweep pulses, and point scans in the frequency domain. Finally, we present a preliminary discussion on the comparison of numerical and experimental results.Keywords: equaliser, metamaterials, musical, instruments
Procedia PDF Downloads 1743074 Improvement and Miniaturization RFID Patch Antenna by Inclusion the Complementary Metamaterials
Authors: Seif Naoui, Lassaad Latrach, Ali Gharsallah
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This paper is specialized to highlight the method of miniaturization and improvement the patch antenna by using the complementary metamaterial. This method is presented by a simple technique is composed a structure of patch antenna integrated in its surface a cell of complementary split ring resonator. This resonator is placed at the middle of the radiating patch in parallel with the transmission line and with a variable angle of orientation. The objective is to find the ultimate angle where the best results are obtained on improving the characteristics of the considered antenna. This motif widespread at the traceability applications by wireless communication for RFID technology at the operation frequency 2.45 GHz. Our contribution is based on studies empirical often presented in this article. All simulation results were made by the CST Microwave Studio.Keywords: complimentary split ring resonators, computer simulation technology microwave studio, metamaterials patch antennas, microstrip patch antenna, radio frequency identification
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