Search results for: high temperature polymer electrolyte membrane fuel cell
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 27952

Search results for: high temperature polymer electrolyte membrane fuel cell

12712 The Connection between Body Composition and Blood Samples Results in Aesthetic Sports

Authors: Réka Kovács, György Téglásy, Szilvia Boros

Abstract:

Introduction: Aim of the Study: Low body fat percentage frequently occurs in aesthetic sports. Because of the unrealistic expectations, their quantity and quality of nutrition intake are inadequate. This can be linked to several health issues which appear in blood samples (iron, ferritin, creatine kinase, etc.). Our retrospective study aimed to investigate the connection between body composition (InBody 770 monitor) and blood samples test results among elite adolescent (14-18 years) and adult (19-28 years) aesthetic athletes. Methods: Data collection happened between 01.08.2022. and 15.08.2022 in National Institute for Sports Medicine, Budapest. The final group consisted of 111 athletes (n=111; adolescents: n=68, adults: n=43). We used descriptive statistics, a two-sample t-test, and correlation analysis with Microsoft Office Excel 2007 software. Our results were considered significant if p<0,05. Results: In 33,3% (37/111) we found low body fat percentage (girls and women: <12%, boys and men: <8%) and in 64% (71/111) high creatine kinase levels. Differences were found mainly in the adolescent group. We found a correlation between body weight and total cholesterol, visceral fat and triglyceride, hematocrit and iron-linking capacity, moreover body fat percentage and ferritin levels. Discussion: It is important to start education about sports nutrition at an early age. The connection between low body fat percentage, serum iron, triglyceride, and ferritin levels refers to the fact that the nutrition intake of the athletes is inadequate. High blood concentrations of creatine kinase may show a lack of proper recovery, which is essential to improve health and performance.

Keywords: body fat percentage, creatine kinase, recovery, sports nutrition

Procedia PDF Downloads 122
12711 Decentralized Peak-Shaving Strategies for Integrated Domestic Batteries

Authors: Corentin Jankowiak, Aggelos Zacharopoulos, Caterina Brandoni

Abstract:

In a context of increasing stress put on the electricity network by the decarbonization of many sectors, energy storage is likely to be the key mitigating element, by acting as a buffer between production and demand. In particular, the highest potential for storage is when connected closer to the loads. Yet, low voltage storage struggles to penetrate the market at a large scale due to the novelty and complexity of the solution, and the competitive advantage of fossil fuel-based technologies regarding regulations. Strong and reliable numerical simulations are required to show the benefits of storage located near loads and promote its development. The present study was restrained from excluding aggregated control of storage: it is assumed that the storage units operate independently to one another without exchanging information – as is currently mostly the case. A computationally light battery model is presented in detail and validated by direct comparison with a domestic battery operating in real conditions. This model is then used to develop Peak-Shaving (PS) control strategies as it is the decentralized service from which beneficial impacts are most likely to emerge. The aggregation of flatter, peak- shaved consumption profiles is likely to lead to flatter and arbitraged profile at higher voltage layers. Furthermore, voltage fluctuations can be expected to decrease if spikes of individual consumption are reduced. The crucial part to achieve PS lies in the charging pattern: peaks depend on the switching on and off of appliances in the dwelling by the occupants and are therefore impossible to predict accurately. A performant PS strategy must, therefore, include a smart charge recovery algorithm that can ensure enough energy is present in the battery in case it is needed without generating new peaks by charging the unit. Three categories of PS algorithms are introduced in detail. First, using a constant threshold or power rate for charge recovery, followed by algorithms using the State Of Charge (SOC) as a decision variable. Finally, using a load forecast – of which the impact of the accuracy is discussed – to generate PS. A performance metrics was defined in order to quantitatively evaluate their operating regarding peak reduction, total energy consumption, and self-consumption of domestic photovoltaic generation. The algorithms were tested on load profiles with a 1-minute granularity over a 1-year period, and their performance was assessed regarding these metrics. The results show that constant charging threshold or power are far from optimal: a certain value is not likely to fit the variability of a residential profile. As could be expected, forecast-based algorithms show the highest performance. However, these depend on the accuracy of the forecast. On the other hand, SOC based algorithms also present satisfying performance, making them a strong alternative when the reliable forecast is not available.

Keywords: decentralised control, domestic integrated batteries, electricity network performance, peak-shaving algorithm

Procedia PDF Downloads 109
12710 LaeA/1-Velvet Interplay in Aspergillus and Trichoderma: Regulation of Secondary Metabolites and Cellulases

Authors: Razieh Karimi Aghcheh, Christian Kubicek, Joseph Strauss, Gerhard Braus

Abstract:

Filamentous fungi are of considerable economic and social significance for human health, nutrition and in white biotechnology. These organisms are dominant producers of a range of primary metabolites such as citric acid, microbial lipids (biodiesel) and higher unsaturated fatty acids (HUFAs). In particular, they produce also important but structurally complex secondary metabolites with enormous therapeutic applications in pharmaceutical industry, for example: cephalosporin, penicillin, taxol, zeranol and ergot alkaloids. Several fungal secondary metabolites, which are significantly relevant to human health do not only include antibiotics, but also e.g. lovastatin, a well-known antihypercholesterolemic agent produced by Aspergillus. terreus, or aflatoxin, a carcinogen produced by A. flavus. In addition to their roles for human health and agriculture, some fungi are industrially and commercially important: Species of the ascomycete genus Hypocrea spp. (teleomorph of Trichoderma) have been demonstrated as efficient producer of highly active cellulolytic enzymes. This trait makes them effective in disrupting and depolymerization of lignocellulosic materials and thus applicable tools in number of biotechnological areas as diverse as clothes-washing detergent, animal feed, and pulp and fuel productions. Fungal LaeA/LAE1 (Loss of aflR Expression A) homologs their gene products act at the interphase between secondary metabolisms, cellulase production and development. Lack of the corresponding genes results in significant physiological changes including loss of secondary metabolite and lignocellulose degrading enzymes production. At the molecular level, the encoded proteins are presumably methyltransferases or demethylases which act directly or indirectly at heterochromatin and interact with velvet domain proteins. Velvet proteins bind to DNA and affect expression of secondary metabolites (SMs) genes and cellulases. The dynamic interplay between LaeA/LAE1, velvet proteins and additional interaction partners is the key for an understanding of the coordination of metabolic and morphological functions of fungi and is required for a biotechnological control of the formation of desired bioactive products. Aspergilli and Trichoderma represent different biotechnologically significant species with significant differences in the LaeA/LAE1-Velvet protein machinery and their target proteins. We, therefore, performed a comparative study of the interaction partners of this machinery and the dynamics of the various protein-protein interactions using our robust proteomic and mass spectrometry techniques. This enhances our knowledge about the fungal coordination of secondary metabolism, cellulase production and development and thereby will certainly improve recombinant fungal strain construction for the production of industrial secondary metabolite or lignocellulose hydrolytic enzymes.

Keywords: cellulases, LaeA/1, proteomics, secondary metabolites

Procedia PDF Downloads 265
12709 Fast Transient Workflow for External Automotive Aerodynamic Simulations

Authors: Christina Peristeri, Tobias Berg, Domenico Caridi, Paul Hutcheson, Robert Winstanley

Abstract:

In recent years the demand for rapid innovations in the automotive industry has led to the need for accelerated simulation procedures while retaining a detailed representation of the simulated phenomena. The project’s aim is to create a fast transient workflow for external aerodynamic CFD simulations of road vehicles. The geometry used was the SAE Notchback Closed Cooling DrivAer model, and the simulation results were compared with data from wind tunnel tests. The meshes generated for this study were of two types. One was a mix of polyhedral cells near the surface and hexahedral cells away from the surface. The other was an octree hex mesh with a rapid method of fitting to the surface. Three different grid refinement levels were used for each mesh type, with the biggest total cell count for the octree mesh being close to 1 billion. A series of steady-state solutions were obtained on three different grid levels using a pseudo-transient coupled solver and a k-omega-based RANS turbulence model. A mesh-independent solution was found in all cases with a medium level of refinement with 200 million cells. Stress-Blended Eddy Simulation (SBES) was chosen for the transient simulations, which uses a shielding function to explicitly switch between RANS and LES mode. A converged pseudo-transient steady-state solution was used to initialize the transient SBES run that was set up with the SIMPLEC pressure-velocity coupling scheme to reach the fastest solution (on both CPU & GPU solvers). An important part of this project was the use of FLUENT’s Multi-GPU solver. Tesla A100 GPU has been shown to be 8x faster than an Intel 48-core Sky Lake CPU system, leading to significant simulation speed-up compared to the traditional CPU solver. The current study used 4 Tesla A100 GPUs and 192 CPU cores. The combination of rapid octree meshing and GPU computing shows significant promise in reducing time and hardware costs for industrial strength aerodynamic simulations.

Keywords: CFD, DrivAer, LES, Multi-GPU solver, octree mesh, RANS

Procedia PDF Downloads 109
12708 Bacteriological Characterization of Drinking Water Distribution Network Biofilms by Gene Sequencing Using Different Pipe Materials

Authors: M. Zafar, S. Rasheed, Imran Hashmi

Abstract:

Very little is concerned about the bacterial contamination in drinking water biofilm which provide a potential source for bacteria to grow and increase rapidly. So as to understand the microbial density in DWDs, a three-month study was carried out. The aim of this study was to examine biofilm in three different pipe materials including PVC, PPR and GI. A set of all these pipe materials was installed in DWDs at nine different locations and assessed on monthly basis. Drinking water quality was evaluated by different parameters and characterization of biofilm. Among various parameters are Temperature, pH, turbidity, TDS, electrical conductivity, BOD, COD, total phosphates, total nitrates, total organic carbon (TOC) free chlorine and total chlorine, coliforms and spread plate counts (SPC) according to standard methods. Predominant species were Bacillus thuringiensis, Pseudomonas fluorescens , Staphylococcus haemolyticus, Bacillus safensis and significant increase in bacterial population was observed in PVC pipes while least in cement pipes. The quantity of DWDs bacteria was directly depended on biofilm bacteria and its increase was correlated with growth and detachment of bacteria from biofilms. Pipe material also affected the microbial community in drinking water distribution network biofilm while Similarity in bacterial species was observed between systems due to same disinfectant dose, time period and plumbing pipes.

Keywords: biofilm, DWDs, pipe material, bacterial population

Procedia PDF Downloads 340
12707 Optimal Dynamic Regime for CO Oxidation Reaction Discovered by Policy-Gradient Reinforcement Learning Algorithm

Authors: Lifar M. S., Tereshchenko A. A., Bulgakov A. N., Guda S. A., Guda A. A., Soldatov A. V.

Abstract:

Metal nanoparticles are widely used as heterogeneous catalysts to activate adsorbed molecules and reduce the energy barrier of the reaction. Reaction product yield depends on the interplay between elementary processes - adsorption, activation, reaction, and desorption. These processes, in turn, depend on the inlet feed concentrations, temperature, and pressure. At stationary conditions, the active surface sites may be poisoned by reaction byproducts or blocked by thermodynamically adsorbed gaseous reagents. Thus, the yield of reaction products can significantly drop. On the contrary, the dynamic control accounts for the changes in the surface properties and adjusts reaction parameters accordingly. Therefore dynamic control may be more efficient than stationary control. In this work, a reinforcement learning algorithm has been applied to control the simulation of CO oxidation on a catalyst. The policy gradient algorithm is learned to maximize the CO₂ production rate based on the CO and O₂ flows at a given time step. Nonstationary solutions were found for the regime with surface deactivation. The maximal product yield was achieved for periodic variations of the gas flows, ensuring a balance between available adsorption sites and the concentration of activated intermediates. This methodology opens a perspective for the optimization of catalytic reactions under nonstationary conditions.

Keywords: artificial intelligence, catalyst, co oxidation, reinforcement learning, dynamic control

Procedia PDF Downloads 117
12706 Land Use Planning Tool to Achieve Land Degradation Neutrality: Tunisia Case Study

Authors: Rafla Attia, Claudio Zucca, Bao Quang Le, Sana Dridi, Thouraya Sahli, Taoufik Hermassi

Abstract:

In Tunisia, landscape change and land degradation are critical issues for landscape conservation, management, and planning. Landscapes are undergoing crucial environmental problems made evident by soil degradation and desertification. Human improper uses of land resources (e.g., unsuitable land uses, unsustainable crop intensification, and poor rangeland management) and climate change are the main factors leading to the landscape transformation and desertification affecting high proportions of the Tunisian lands. Land use planning (LUP) to achieve Land Degradation Neutrality (LDN) must be supported by methodologies and technologies that help identify best solutions and practices and design context-specific sustainable land management (SLM) strategies. Such strategies must include restoration or rehabilitation efforts in areas with high land degradation, as well as prevention of degradation that could be caused by improper land use (LU) and land management (LM). The geoinformatics Land Use Planning for LDN (LUP4LDN) tool has been designed for this purpose. Its aim is to support national and sub-national planners in i) mapping geographic patterns of current land degradation; ii) anticipating further future land degradation expected in areas that are unsustainably managed; and iii) providing an interactive procedure for developing participatory LU-LM transitional scenarios over selected regions of interest and timeframes, visualizing the related expected levels of impacts on ecosystem services via maps and graphs. The tool has been co-developed and piloted with national stakeholders in Tunisia. The piloting implementation assessed how the LUP4LDN tool fits with existing LUP processes and the benefits achieved by using the tool to support land use planning for LDN.

Keywords: land use system, land cover, sustainable land management, land use planning for land degradation neutrality

Procedia PDF Downloads 71
12705 Quantitative Assessment of Different Formulations of Antimalarials in Sentinel Sites of India

Authors: Taruna Katyal Arora, Geeta Kumari, Hari Shankar, Neelima Mishra

Abstract:

Substandard and counterfeit antimalarials is a major problem in malaria endemic areas. The availability of counterfeit/ substandard medicines is not only decreasing the efficacy in patients, but it is also one of the contributing factors for developing antimalarial drug resistance. Owing to this, a pilot study was conducted to survey quality of drugs collected from different malaria endemic areas of India. Artesunate+Sulphadoxine-Pyrimethamine (AS+SP), Artemether-Lumefantrine (AL), Chloroquine (CQ) tablets were randomly picked from public health facilities in selected states of India. The quality of antimalarial drugs from these areas was assessed by using Global Pharma Health Fund Minilab test kit. This includes physical/visual inspection and disintegration test. Thin-layer chromatography (TLC) was carried out for semi-quantitative assessment of active pharmaceutical ingredients. A total of 45 brands, out of which 21 were for CQ, 14 for AL and 10 for AS+SP were tested from Uttar Pradesh (U.P.), Mizoram, Meghalaya and Gujrat states. One out of 45 samples showed variable disintegration and retension factor. The variable disintegration and retention factor which would have been due to substandard quality or other factors including storage. However, HPLC analysis confirms standard active pharmaceutical ingredient, but may be due to humid temperature and moisture in storage may account for the observed result.

Keywords: antimalarial medicines, counterfeit, substandard, TLC

Procedia PDF Downloads 311
12704 Mesoporous BiVO4 Thin Films as Efficient Visible Light Driven Photocatalyst

Authors: Karolina Ordon, Sandrine Coste, Malgorzata Makowska-Janusik, Abdelhadi Kassiba

Abstract:

Photocatalytic processes play key role in the production of a new source of energy (as hydrogen), design of self-cleaning surfaces or for the environment preservation. The most challenging task deals with the purification of water distinguished by high efficiency. In the mentioned process, organic pollutants in solutions are decomposed to the simple, non-toxic compounds as H2O and CO2. The most known photocatalytic materials are ZnO, CdS and TiO2 semiconductors with a particular involvement of TiO2 as an efficient photocatalysts even with a high band gap equal to 3.2 eV which exploit only UV radiation from solar emitted spectrum. However, promising material with visible light induced photoactivity was searched through the monoclinic polytype of BiVO4 which has energy gap about 2.4 eV. As required in heterogeneous photocatalysis, the high contact surface is required. Also, BiVO4 as photocatalyst can be optimized by increasing its surface area by achieving the mesoporous structure synthesize. The main goal of the present work consists in the synthesis and characterization of BiVO4 mesoporous thin film. The synthesis method based on sol-gel was carried out using a standard surfactants such as P123 and F127. The thin film was deposited by spin and dip coating method. Then, the structural analysis of the obtained material was performed thanks to X-ray diffraction (XRD) and Raman spectroscopy. The surface of resulting structure was investigated using a scanning electron microscopy (SEM). The computer simulations based on modeling the optical and electronic properties of bulk BiVO4 by using DFT (density functional theory) methodology were carried out. The semiempirical parameterized method PM6 was used to compute the physical properties of BiVO4 nanostructures. The Raman and IR absorption spectra were also measured for synthesized mesoporous material, and the results were compared with the theoretical predictions. The simulations of nanostructured BiVO4 have pointed out the occurrence of quantum confinement for nanosized clusters leading to widening of the band gap. This result overcame the relevance of nanosized objects to harvest wide part of the solar spectrum. Also, a balance was searched experimentally through the mesoporous nature of the films devoted to enhancing the contact surface as required for heterogeneous catalysis without to lower the nanocrystallite size under some critical sizes inducing an increased band gap. The present contribution will discuss the relevant features of the mesoporous films with respect to their photocatalytic responses.

Keywords: bismuth vanadate, photocatalysis, thin film, quantum-chemical calculations

Procedia PDF Downloads 318
12703 Damage to Strawberries Caused by Simulated Transport

Authors: G. La Scalia, M. Enea, R. Micale, O. Corona, L. Settanni

Abstract:

The quality and condition of perishable products delivered to the market and their subsequent selling prices are directly affected by the care taken during harvesting and handling. Mechanical injury, in fact, occurs at all stages, from pre-harvest operations through post-harvest handling, packing and transport to the market. The main implications of this damage are the reduction of the product’s quality and economical losses related to the shelf life diminution. For most perishable products, the shelf life is relatively short and it is typically dictated by microbial growth related to the application of dynamic and static loads during transportation. This paper presents the correlation between vibration levels and microbiological growth on strawberries and woodland strawberries and detects the presence of volatile organic compounds (VOC) in order to develop an intelligent logistic unit capable of monitoring VOCs using a specific sensor system. Fresh fruits were exposed to vibrations by means of a vibrating table in a temperature-controlled environment. Microbiological analyses were conducted on samples, taken at different positions along the column of the crates. The values obtained were compared with control samples not exposed to vibrations and the results show that different positions along the column influence the development of bacteria, yeasts and filamentous fungi.

Keywords: microbiological analysis, shelf life, transport damage, volatile organic compounds

Procedia PDF Downloads 418
12702 Development and Validation of Thermal Stability in Complex System ABDM has two ASIC by NISA and COMSOL Tools

Authors: A. Oukaira, A. Lakhssassi, O. Ettahri

Abstract:

To make a good thermal management in an ABDM (Adapter Board Detector Module) card, we must first control temperature and its gradient from the first step in the design of integrated circuits ASIC of our complex system. In this paper, our main goal is to develop and validate the thermal stability in order to get an idea of the flow of heat around the ASIC in transient and thus address the thermal issues for integrated circuits at the ABDM card. However, we need heat sources simulations for ABDM card to establish its thermal mapping. This led us to perform simulations at each ASIC that will allow us to understand the thermal ABDM map and find real solutions for each one of our complex system that contains 36 ABDM map, taking into account the different layers around ASIC. To do a transient simulation under NISA, we had to build a function of power modulation in time TIMEAMP. The maximum power generated in the ASIC is 0.6 W. We divided the power uniformly in the volume of the ASIC. This power was applied for 5 seconds to visualize the evolution and distribution of heat around the ASIC. The DBC (Dirichlet Boundary conditions) method was applied around the ABDM at 25°C and just after these simulations in NISA tool we will validate them by COMSOL tool, wich is a numerical calculation software for a modular finite element for modeling a wide variety of physical phenomena characterizing a real problem. It will also be a design tool with its ability to handle 3D geometries for complex systems.

Keywords: ABDM, APD, thermal mapping, complex system

Procedia PDF Downloads 257
12701 The Use of Artificial Intelligence in Diagnosis of Mastitis in Cows

Authors: Djeddi Khaled, Houssou Hind, Miloudi Abdellatif, Rabah Siham

Abstract:

In the field of veterinary medicine, there is a growing application of artificial intelligence (AI) for diagnosing bovine mastitis, a prevalent inflammatory disease in dairy cattle. AI technologies, such as automated milking systems, have streamlined the assessment of key metrics crucial for managing cow health during milking and identifying prevalent diseases, including mastitis. These automated milking systems empower farmers to implement automatic mastitis detection by analyzing indicators like milk yield, electrical conductivity, fat, protein, lactose, blood content in the milk, and milk flow rate. Furthermore, reports highlight the integration of somatic cell count (SCC), thermal infrared thermography, and diverse systems utilizing statistical models and machine learning techniques, including artificial neural networks, to enhance the overall efficiency and accuracy of mastitis detection. According to a review of 15 publications, machine learning technology can predict the risk and detect mastitis in cattle with an accuracy ranging from 87.62% to 98.10% and sensitivity and specificity ranging from 84.62% to 99.4% and 81.25% to 98.8%, respectively. Additionally, machine learning algorithms and microarray meta-analysis are utilized to identify mastitis genes in dairy cattle, providing insights into the underlying functional modules of mastitis disease. Moreover, AI applications can assist in developing predictive models that anticipate the likelihood of mastitis outbreaks based on factors such as environmental conditions, herd management practices, and animal health history. This proactive approach supports farmers in implementing preventive measures and optimizing herd health. By harnessing the power of artificial intelligence, the diagnosis of bovine mastitis can be significantly improved, enabling more effective management strategies and ultimately enhancing the health and productivity of dairy cattle. The integration of artificial intelligence presents valuable opportunities for the precise and early detection of mastitis, providing substantial benefits to the dairy industry.

Keywords: artificial insemination, automatic milking system, cattle, machine learning, mastitis

Procedia PDF Downloads 53
12700 Detection of Defects in CFRP by Ultrasonic IR Thermographic Method

Authors: W. Swiderski

Abstract:

In the paper introduced the diagnostic technique making possible the research of internal structures in composite materials reinforced fibres using in different applications. The main reason of damages in structures of these materials is the changing distribution of load in constructions in the lifetime. Appearing defect is largely complicated because of the appearance of disturbing of continuity of reinforced fibres, binder cracks and loss of fibres adhesiveness from binders. Defect in composite materials is usually more complicated than in metals. At present, infrared thermography is the most effective method in non-destructive testing composite. One of IR thermography methods used in non-destructive evaluation is vibrothermography. The vibrothermography is not a new non-destructive method, but the new solution in this test is use ultrasonic waves to thermal stimulation of materials. In this paper, both modelling and experimental results which illustrate the advantages and limitations of ultrasonic IR thermography in inspecting composite materials will be presented. The ThermoSon computer program for computing 3D dynamic temperature distribuions in anisotropic layered solids with subsurface defects subject to ulrasonic stimulation was used to optimise heating parameters in the detection of subsurface defects in composite materials. The program allows for the analysis of transient heat conduction and ultrasonic wave propagation phenomena in solids. The experiments at MIAT were fulfilled by means of FLIR SC 7600 IR camera. Ultrasonic stimulation was performed with the frequency from 15 kHz to 30 kHz with maximum power up to 2 kW.

Keywords: composite material, ultrasonic, infrared thermography, non-destructive testing

Procedia PDF Downloads 292
12699 Nonlinear Evolution of the Pulses of Elastic Waves in Geological Materials

Authors: Elena B. Cherepetskaya, Alexander A. Karabutov, Natalia B. Podymova, Ivan Sas

Abstract:

Nonlinear evolution of broadband ultrasonic pulses passed through the rock specimens is studied using the apparatus ‘GEOSCAN-02M’. Ultrasonic pulses are excited by the pulses of Q-switched Nd:YAG laser with the time duration of 10 ns and with the energy of 260 mJ. This energy can be reduced to 20 mJ by some light filters. The laser beam radius did not exceed 5 mm. As a result of the absorption of the laser pulse in the special material – the optoacoustic generator–the pulses of longitudinal ultrasonic waves are excited with the time duration of 100 ns and with the maximum pressure amplitude of 10 MPa. The immersion technique is used to measure the parameters of these ultrasonic pulses passed through a specimen, the immersion liquid is distilled water. The reference pulse passed through the cell with water has the compression and the rarefaction phases. The amplitude of the rarefaction phase is five times lower than that of the compression phase. The spectral range of the reference pulse reaches 10 MHz. The cubic-shaped specimens of the Karelian gabbro are studied with the rib length 3 cm. The ultimate strength of the specimens by the uniaxial compression is (300±10) MPa. As the reference pulse passes through the area of the specimen without cracks the compression phase decreases and the rarefaction one increases due to diffraction and scattering of ultrasound, so the ratio of these phases becomes 2.3:1. After preloading some horizontal cracks appear in the specimens. Their location is found by one-sided scanning of the specimen using the backward mode detection of the ultrasonic pulses reflected from the structure defects. Using the computer processing of these signals the images are obtained of the cross-sections of the specimens with cracks. By the increase of the reference pulse amplitude from 0.1 MPa to 5 MPa the nonlinear transformation of the ultrasonic pulse passed through the specimen with horizontal cracks results in the decrease by 2.5 times of the amplitude of the rarefaction phase and in the increase of its duration by 2.1 times. By the increase of the reference pulse amplitude from 5 MPa to 10 MPa the time splitting of the phases is observed for the bipolar pulse passed through the specimen. The compression and rarefaction phases propagate with different velocities. These features of the powerful broadband ultrasonic pulses passed through the rock specimens can be described by the hysteresis model of Preisach-Mayergoyz and can be used for the location of cracks in the optically opaque materials.

Keywords: cracks, geological materials, nonlinear evolution of ultrasonic pulses, rock

Procedia PDF Downloads 345
12698 Numerical Studies for Standard Bi-Conjugate Gradient Stabilized Method and the Parallel Variants for Solving Linear Equations

Authors: Kuniyoshi Abe

Abstract:

Bi-conjugate gradient (Bi-CG) is a well-known method for solving linear equations Ax = b, for x, where A is a given n-by-n matrix, and b is a given n-vector. Typically, the dimension of the linear equation is high and the matrix is sparse. A number of hybrid Bi-CG methods such as conjugate gradient squared (CGS), Bi-CG stabilized (Bi-CGSTAB), BiCGStab2, and BiCGstab(l) have been developed to improve the convergence of Bi-CG. Bi-CGSTAB has been most often used for efficiently solving the linear equation, but we have seen the convergence behavior with a long stagnation phase. In such cases, it is important to have Bi-CG coefficients that are as accurate as possible, and the stabilization strategy, which stabilizes the computation of the Bi-CG coefficients, has been proposed. It may avoid stagnation and lead to faster computation. Motivated by a large number of processors in present petascale high-performance computing hardware, the scalability of Krylov subspace methods on parallel computers has recently become increasingly prominent. The main bottleneck for efficient parallelization is the inner products which require a global reduction. The resulting global synchronization phases cause communication overhead on parallel computers. The parallel variants of Krylov subspace methods reducing the number of global communication phases and hiding the communication latency have been proposed. However, the numerical stability, specifically, the convergence speed of the parallel variants of Bi-CGSTAB may become worse than that of the standard Bi-CGSTAB. In this paper, therefore, we compare the convergence speed between the standard Bi-CGSTAB and the parallel variants by numerical experiments and show that the convergence speed of the standard Bi-CGSTAB is faster than the parallel variants. Moreover, we propose the stabilization strategy for the parallel variants.

Keywords: bi-conjugate gradient stabilized method, convergence speed, Krylov subspace methods, linear equations, parallel variant

Procedia PDF Downloads 155
12697 Effect of Sr-Doping on Multiferroic Properties of Ca₁₋ₓSrₓMn₇O₁₂

Authors: Parul Jain, Jitendra Saha, L. C. Gupta, Satyabrata Patnaik, Ashok K. Ganguli, Ratnamala Chatterjee

Abstract:

This study shows how sensitively and drastically multiferroic properties of CaMn₇O₁₂ get modified by isovalent Sr-doping, namely, in Ca₁₋ₓSrₓMn₇O₁₂ for x as small as 0.01 and 0.02. CaMn₇O₁₂ is a type-II multiferroic, wherein polarization is caused by magnetic spin ordering. In this report magnetic and ferroelectric properties of Ca₁₋ₓSrₓMn₇O₁₂ (0 ≤ x ≤ 0.1) are investigated. Samples were prepared by wet sol gel technique using their respective nitrates; powders thus obtained were calcined and sintered in optimized conditions. The X-ray diffraction patterns of all samples doped with Sr concentrations in the range (0 ≤ x ≤ 10%) were found to be free from secondary phases. Magnetization versus temperature and magnetization versus field measurements were carried out using Quantum Design SQUID magnetometer. Pyroelectric current measurements were done for finding the polarization in the samples. Findings of the measurements are: (i) increase of Sr-doping in CaMn₇O₁₂ lattice i.e. for x ≤ 0.02, increases the polarization, whereas decreases the magnetization and the coercivity of the samples; (ii) the material with x = 0.02 exhibits ferroelectric polarization Ps which is more than double the Ps in the un-doped material and the magnetization M is reduced to less than half of that of the pure material; remarkably (iii) the modifications in Ps and M are reversed as x increases beyond x = 0.02 and for x = 0.10, Ps is reduced even below that for the pure sample; (iv) there is no visible change of the two magnetic transitions TN1 (90 K) and TN2 (48 K) of the pure material as a function of x. The strong simultaneous variations of Ps and M for x = 0.02 strongly suggest that either a basic modification of the magnetic structure of the material or a significant change of the coupling of P and M or possibly both.

Keywords: ferroelectric, isovalent, multiferroic, polarization, pyroelectric

Procedia PDF Downloads 457
12696 Alternate Approaches to Quality Measurement: An Exploratory Study in Differentiation of “Quality” Characteristics in Services and Supports

Authors: Caitlin Bailey, Marian Frattarola Saulino, Beth Steinberg

Abstract:

Today, virtually all programs offered to people with intellectual and developmental disabilities tout themselves as person-centered, community-based and inclusive, yet there is a vast range in type and quality of services that use these similar descriptors. The issue is exacerbated by the fields’ measurement practices around quality, inclusion, independent living, choice and person-centered outcomes. For instance, community inclusion for people with disabilities is often measured by the number of times person steps into his or her community. These measurement approaches set standards for quality too low so that agencies supporting group home residents to go bowling every week can report the same outcomes as an agency that supports one person to join a book club that includes people based on their literary interests rather than disability labels. Ultimately, lack of delineation in measurement contributes to the confusion between face value “quality” and true quality services and supports for many people with disabilities and their families. This exploratory study adopts alternative approaches to quality measurement including co-production methods and systems theoretical framework in order to identify the factors that 1) lead to high-quality supports and, 2) differentiate high-quality services. Project researchers have partnered with community practitioners who are all committed to providing quality services and supports but vary in the degree to which they are actually able to provide them. The study includes two parts; first, an online survey distributed to more than 500 agencies that have demonstrated commitment to providing high-quality services; and second, four in-depth case studies with agencies in three United States and Israel providing a variety of supports to children and adults with disabilities. Results from both the survey and in-depth case studies were thematically analyzed and coded. Results show that there are specific factors that differentiate service quality; however meaningful quality measurement practices also require that researchers explore the contextual factors that contribute to quality. These not only include direct services and interactions, but also characteristics of service users, their environments as well as organizations providing services, such as management and funding structures, culture and leadership. Findings from this study challenge researchers, policy makers and practitioners to examine existing quality service standards and measurements and to adopt alternate methodologies and solutions to differentiate and scale up evidence-based quality practices so that all people with disabilities have access to services that support them to live, work, and enjoy where and with whom they choose.

Keywords: co-production, inclusion, independent living, quality measurement, quality supports

Procedia PDF Downloads 391
12695 Economic Analysis of Coffee Cultivation in Kodagu District of Karnataka State, India

Authors: P. S. Dhananjaya Swamy, B. Chinnappa, G. B. Ramesh, Naveen P. Kumar

Abstract:

Kodagu district is one of the most densely forested districts in the India as around sixty five per cent of geographical areas under tree cover. Nearly 53 per cent of the flora of Kodagu is endemic. The district is also a hotspot of endemic orchids found mainly in the Thadiandamol. Shade grown, eco-friendly coffee farms are perhaps a selected few places on this planet where nature runs wild. The Kodagu accounts for more than 8.8 per cent of floral diversity of Karnataka state. Estimation of unit cost of cultivation plays a vital role in determining the governmental program their market intervention policies. On an average, planters incurred around Rs. 17041 per acre. The extent of production risk was highest among small category of planters (66 %) compared to other two exhibiting production instability. The result shows that, the coffee productivity in medium plantations was 1051.2 kg per acre as against 758.5 and 789.2 kg in the case of small and large plantations. An annual net return per acre was highest in the case of medium planters (Rs. 26109.3) as against Rs. 20566.7 and Rs. 18572.7 in the case of small and large planters. Cost of production was lowest in the case of small planters (Rs. 18.9 per kg of output) followed by medium planters (Rs. 21.2 per kg of output) and large planters (Rs. 22.5 per kg of output). The productivity of coffee is less whenever it is grown under high shade and native tree cover; it is around 6 quintals per acre when compared with low shade conditions, which is around 8.9 quintals per acre, without a significant difference in the amount invested for growing coffee. Net gain was lower by Rs. 15.5 per kg for the planters growing under high shade and native trees cover when compared with low shade and exotic trees cover.

Keywords: coffee, cultivation, economics, Kodagu

Procedia PDF Downloads 184
12694 Dynamic High-Rise Moment Resisting Frame Dissipation Performances Adopting Glazed Curtain Walls with Superelastic Shape Memory Alloy Joints

Authors: Lorenzo Casagrande, Antonio Bonati, Ferdinando Auricchio, Antonio Occhiuzzi

Abstract:

This paper summarizes the results of a survey on smart non-structural element dynamic dissipation when installed in modern high-rise mega-frame prototypes. An innovative glazed curtain wall was designed using Shape Memory Alloy (SMA) joints in order to increase the energy dissipation and enhance the seismic/wind response of the structures. The studied buildings consisted of thirty- and sixty-storey planar frames, extracted from reference three-dimensional steel Moment Resisting Frame (MRF) with outriggers and belt trusses. The internal core was composed of a CBF system, whilst outriggers were placed every fifteen stories to limit second order effects and inter-storey drifts. These structural systems were designed in accordance with European rules and numerical FE models were developed with an open-source code, able to account for geometric and material nonlinearities. With regard to the characterization of non-structural building components, full-scale crescendo tests were performed on aluminium/glass curtain wall units at the laboratory of the Construction Technologies Institute (ITC) of the Italian National Research Council (CNR), deriving force-displacement curves. Three-dimensional brick-based inelastic FE models were calibrated according to experimental results, simulating the fac¸ade response. Since recent seismic events and extreme dynamic wind loads have generated the large occurrence of non-structural components failure, which causes sensitive economic losses and represents a hazard for pedestrians safety, a more dissipative glazed curtain wall was studied. Taking advantage of the mechanical properties of SMA, advanced smart joints were designed with the aim to enhance both the dynamic performance of the single non-structural unit and the global behavior. Thus, three-dimensional brick-based plastic FE models were produced, based on the innovated non-structural system, simulating the evolution of mechanical degradation in aluminium-to-glass and SMA-to-glass connections when high deformations occurred. Consequently, equivalent nonlinear links were calibrated to reproduce the behavior of both tested and smart designed units, and implemented on the thirty- and sixty-storey structural planar frame FE models. Nonlinear time history analyses (NLTHAs) were performed to quantify the potential of the new system, when considered in the lateral resisting frame system (LRFS) of modern high-rise MRFs. Sensitivity to the structure height was explored comparing the responses of the two prototypes. Trends in global and local performance were discussed to show that, if accurately designed, advanced materials in non-structural elements provide new sources of energy dissipation.

Keywords: advanced technologies, glazed curtain walls, non-structural elements, seismic-action reduction, shape memory alloy

Procedia PDF Downloads 327
12693 Impact of Fly Ash on Soil Quality in Semi-Arid Region

Authors: Anjuri Srivastava, Akhouri Nishant Bhanu

Abstract:

Soil is a natural material with a distinctive form. It is regarded to be a natural source of nutrients and minerals for plants. It meets many of our needs through the crops, trees, and inhabited places that have grown on or underneath it. Productive and rich soil plays a crucial role in both its wealth and well-being. If any external substance changes the soil's composition, it directly impacts the plant that was grown in that soil. If the soil is deficient in one or more essential components, fly ash can be utilized as fertilizer by incorporating it into the soil. This can also increase the porosity of the soil. Fly ash has a sufficient concentration of essential components to promote the growth of plants. The high concentration of elements in fly ash, including C, Na, K, Fe, and Zn, increases crop yields. Hazardous compounds harm plant life as soon as they get into the soil. The US Environmental Protection Agency and other regulatory agencies have found it as non-hazardous. By employing fly ash as a potential fertilizer supplement for degraded soils, the problem of disposing of solid waste can be partially handled. Fly ash's rapid growth can slow down mineralization because it contains a higher proportion of harmful heavy metals. The chemical characteristics, inclusion ratio, and composting process of fly ash have a significant impact on the fly ash compost’s potential to improve soil nutrition. Research institutions and regulatory agencies have been thoroughly investigating fly ash for a long time. Guard cells on plant leaves that accumulate fly ash trigger the regulatory system. Fly ash increases both chemical and physical damage at certain humidity levels. The lengthy sowing period is caused by the high levels of fly ash in the soil, which also slows down seedling germination and growth. For the sake of human health, it is crucial to consider the bioaccumulation of dangerous heavy metals and their necessary concentrations in plant tissues and soil.

Keywords: soil, fly ash, plant, fertilizer, composts

Procedia PDF Downloads 87
12692 Development, Optimization, and Validation of a Synchronous Fluorescence Spectroscopic Method with Multivariate Calibration for the Determination of Amlodipine and Olmesartan Implementing: Experimental Design

Authors: Noha Ibrahim, Eman S. Elzanfaly, Said A. Hassan, Ahmed E. El Gendy

Abstract:

Objectives: The purpose of the study is to develop a sensitive synchronous spectrofluorimetric method with multivariate calibration after studying and optimizing the different variables affecting the native fluorescence intensity of amlodipine and olmesartan implementing an experimental design approach. Method: In the first step, the fractional factorial design used to screen independent factors affecting the intensity of both drugs. The objective of the second step was to optimize the method performance using a Central Composite Face-centred (CCF) design. The optimal experimental conditions obtained from this study were; a temperature of (15°C ± 0.5), the solvent of 0.05N HCl and methanol with a ratio of (90:10, v/v respectively), Δλ of 42 and the addition of 1.48 % surfactant providing a sensitive measurement of amlodipine and olmesartan. The resolution of the binary mixture with a multivariate calibration method has been accomplished mainly by using partial least squares (PLS) model. Results: The recovery percentage for amlodipine besylate and atorvastatin calcium in tablets dosage form were found to be (102 ± 0.24, 99.56 ± 0.10, for amlodipine and Olmesartan, respectively). Conclusion: Method is valid according to some International Conference on Harmonization (ICH) guidelines, providing to be linear over a range of 200-300, 500-1500 ng mL⁻¹ for amlodipine and Olmesartan. The methods were successful to estimate amlodipine besylate and olmesartan in bulk powder and pharmaceutical preparation.

Keywords: amlodipine, central composite face-centred design, experimental design, fractional factorial design, multivariate calibration, olmesartan

Procedia PDF Downloads 144
12691 Serum Zinc Level in Patients with Multidrug Resistant Tuberculosis

Authors: Nilima Barman, M. Atiqul Haque, Debabrata Ghosh

Abstract:

Background: Zinc, one of the vital micronutrients, has an incredible role in the immune system. Hypozincemia affects host defense by reducing the number of circulating T cells and phagocytosis activity of other cells which ultimately impair cell-mediated immunity 1, 2. The immune system is detrimentally suppressed in multidrug-resistant tuberculosis (MDR-TB) 3, 4, a major threat of TB control worldwide5. As zinc deficiency causes immune suppression, we assume that it might have a role in the development of MDR-TB. Objectives: To estimate the serum zinc level in newly diagnosed multidrug resistant tuberculosis (MDR-TB) in comparison with that of newly diagnosed pulmonary TB (NdPTB) and healthy individuals. Materials and Methods: This study was carried out in the department of Public Health and Informatics, Bangabandhu Sheikh Mujib Medical University, Dhaka in collaboration with National Institute of Diseases of the Chest Hospital (NIDCH), Bangladesh from March’ 2012 to February 2013. A total of 337 respondents, of them 107 were MDR TB patients enrolled from NIDCH, 69 were NdPTB and 161 were healthy adults. All NdPTB patients and healthy adults were randomly selected from Sirajdikhan subdistrict of Munshiganj District. It is a rural community 22 kilometer south from capital city Dhaka. Serum zinc level was estimated by atomic absorption spectrophotometry method from early morning fasting blood sample. The evaluation of serum zinc level was done according to normal range from 70 to120 µgm/dL6. Results: Males were predominant in study groups (p>0.05). Mean (sd) serum zinc levels in MDR-TB, NdPTB and healthy adult group were 65.14 (12.52), 75.22(15.89), and 87.98 (21.80) μgm/dL respectively and differences were statistically significant (F=52.08, P value<0.001). After multiple comparison test (Bonferroni test) significantly lower level of serum zinc was found in MDRTB group than NdPTB and healthy adults (p<.001). Point biserial correlation showed a negative association of having MDR TB and serum zinc level (r= -.578; p value <0.001). Conclusion: The significant low level of serum zinc in MDR-TB patients suggested impaired immune status. We recommended for further exploration of low level of serum zinc as risk factor of MDR TB.

Keywords: Bangladesh, immune status, multidrug-resistant tuberculosis, serum zinc

Procedia PDF Downloads 581
12690 Awareness on Risk Factors of Cardiovascular Disease among Patients with Diabetes Mellitus Attending Diabetic Clinic of B. P. Koirala Institute of Health Sciences

Authors: Ram Sharan Mehta, Dina Khanal, Pushpa Parajuli, Gayanand Mandal, Bijaya Bartuala

Abstract:

Background: Cardiovascular disease (CVD) is the leading cause of death worldwide. Adequate awareness of risk factors of CVD is the first step towards effective preventive strategies to combat the CVD burden in diabetes patients.This study aims to assess the awareness on risk factors of CVD among patients with diabetes mellitus attending diabetic clinic of BPKIHS and to find the association between awareness with their selected socio demographic variables. Methods and Material: A descriptive cross sectional study was conducted among 112 patients with diabetes in diabetic clinic of BPKIHS. Convenient sampling technique was used for data collection over duration of one month using interview schedule by HDFQ II tool. Data were analyzed by using descriptive and inferential statistics. (Chi square). Results: The mean age of respondents was 55.4±12.13 years. That mean HDFQ score was 14.31± 5.08. Only 33% of the respondents had adequate level of awareness whereas majority of the respondents (67%) had inadequate level of awareness. Majority of the respondent (83.9%) were aware about smoking, (78.6%) physical activity, (75%) increasing age, (75.9%) high blood pressure, (71.4%) overweight respectively. Whereas most of the respondents were not aware of high cholesterol, fatty diet, preventive strategies and association of diabetes with CVD. Awareness was statistically significant with (p=0.043) educational status, (p=0.025) monthly income, (p=0.05) residence, (p=0.006) CVD information received and (p=0.022) co morbid condition as a heart disease. Conclusion: The findings of this study concluded most of the respondents had an inadequate level of awareness on risk factors of CVD. So Effective education and appropriate preventive strategies of CVD are indeed important to reduce CVD burden in diabetes patients.

Keywords: cardiovascular disease, awareness, diabetes patients, risk

Procedia PDF Downloads 126
12689 Synthesis of Novel Nanostructure Copper(II) Metal-Organic Complex for Photocatalytic Degradation of Remdesivir Antiviral COVID-19 from Aqueous Solution: Adsorption Kinetic and Thermodynamic Studies

Authors: Sam Bahreini, Payam Hayati

Abstract:

Metal-organic coordination [Cu(L)₄(SCN)₂] was synthesized applying ultrasonic irradiation, and its photocatalytic performance for the degradation of Remdesivir (RS) under sunlight irradiation was systematically explored for the first time in this study. The physicochemical properties of the synthesized photocatalyst were investigated using Fourier-transform infrared (FT-IR), field emission scanning electron microscopy (FE-SEM), powder x-ray diffraction (PXRD), energy-dispersive x-ray (EDX), thermal gravimetric analysis (TGA), diffuse reflectance spectroscopy (DRS) techniques. Systematic examinations were carried out by changing irradiation time, temperature, solution pH value, contact time, RS concentration, and catalyst dosage. The photodegradation kinetic profiles were modeled in pseudo-first order, pseudo-second-order, and intraparticle diffusion models reflected that photodegradation onto [Cu(L)₄(SCN)₂] catalyst follows pseudo-first order kinetic model. The fabricated [Cu(L)₄(SCN)₂] nanostructure bandgap was determined as 2.60 eV utilizing the Kubelka-Munk formula from the diffuse reflectance spectroscopy method. Decreasing chemical oxygen demand (COD) (from 70.5 mgL-1 to 36.4 mgL-1) under optimal conditions well confirmed mineralizing of the RS drug. The values of ΔH° and ΔS° was negative, implying the process of adsorption is spontaneous and more favorable in lower temperatures.

Keywords: Photocatalytic degradation, COVID-19, density functional theory (DFT), molecular electrostatic potential (MEP)

Procedia PDF Downloads 162
12688 Evidence-Based Policy Making to Improve Human Security in Pakistan

Authors: Ayesha Akbar

Abstract:

Pakistan is moving from a security state to a welfare state despite several security challenges both internal and external. Human security signifies a varied approach in different regions depending upon the leadership and policy priorities. The link between human development and economic growth is not automatic. It has to be created consciously by forward-looking policies and strategies by national governments. There are seven components or categories of human security these include: Economic Security, Personal Security, Health Security, Environmental Security, Food Security, Community Security and Political Security. The increasing interest of the international community to clearly understand the dimensions of human security provided the grounds to Pakistani scholars as well to ponder on the issue and delineate lines of human security. A great deal of work has been either done or in process to evaluate human security indicators in Pakistan. Notwithstanding, after having been done a great deal of work the human security in Pakistan is not satisfactory. A range of deteriorating indicators of human development that lies under the domain of human security leaves certain inquiries to be answered. What are the dimensions of human security in Pakistan? And how are they being dealt from the perspective of policy and institution in terms of its operationalization in Pakistan? Is the human security discourse reflects evidence-based policy changes. The methodology is broadly based on qualitative methods that include interviews, content analysis of policy documents. Pakistan is among the most populous countries in the world and faces high vulnerability to climate change. Literacy rate has gone down with the surge of youth bulge to accommodate in the job market. Increasing population is creating food problems as the resources have not been able to compete with the raising demands of food and other social amenities of life. Majority of the people are facing acute poverty. Health outcomes are also not satisfactory with the high infant and maternal mortality rate. Pakistan is on the verge of facing water crisis as the water resources are depleting so fast with the high demand in agriculture and energy sector. Pakistan is striving hard to deal with the declining state of human security but the dilemma is lack of resources that hinders in meeting up with the emerging demands. The government requires to bring about more change with scaling-up economic growth avenues with enhancing the capacity of human resources. A modern performance drive culture with the integration of technology is required to deliver efficient and effective service delivery. On an already fast track process of reforms; e-governance and evidence based policy mechanism is being instilled in the government process for better governance and evidence based decisions.

Keywords: governance, human development index, human security, Pakistan, policy

Procedia PDF Downloads 247
12687 Evaluating Evaporation and Seepage Losses in Lakes Using Sentinel Images and the Water Balance Equation

Authors: Abdelrahman Elsehsah

Abstract:

The main objective of this study is to assess changes in the water capacity of Aswan High Dam Lake (AHDL) caused by evaporation and seepage losses. To achieve this objective, a comprehensive methodology was employed. The methodology involves acquiring Sentinel-3 imagery and extracting the surface area of the lake using remote sensing techniques. Using water areas calculated from sentinel images, collected field data, and the lake’s water balance equation, monthly evaporation and seepage losses were estimated for the years 2021 and 2022. Based on the water balance method results, the average monthly evaporation losses for the year 2021 were estimated to be around 1.41 billion cubic meters (Bm3), which closely matches the estimates provided by the Ministry of Water Resources and Irrigation (MWRI) annual reports (approximately 1.37 Bm3 in the same year). This means that the water balance method slightly overestimated the monthly evaporation losses by about 2.92%. Similarly, the average monthly seepage losses for the year 2022 were estimated to be around 0.005 Bm3, while the MWRI reports indicated approximately 0.0046 Bm3. By another means, the water balance method overestimated the monthly seepage losses by about 8.70%. Furthermore, the study found that the average monthly evaporation rate within AHDL was 210.88 mm/month, which closely aligns with the computed value of approximately 204.9 mm/month by AHDA. These findings indicated that the applied water balance method, utilizing remote sensing and field data, is a reliable tool for estimating monthly evaporation and seepage losses as well as monthly evaporation rates in AHDL.

Keywords: Aswan high dam lake, remote sensing, water balance equation, seepage loss, evaporation loss

Procedia PDF Downloads 19
12686 The Effects and Interactions of Synthesis Parameters on Properties of Mg Substituted Hydroxyapatite

Authors: S. Sharma, U. Batra, S. Kapoor, A. Dua

Abstract:

In this study, the effects and interactions of reaction time and capping agent assistance during sol-gel synthesis of magnesium substituted hydroxyapatite nanopowder (MgHA) on hydroxyapatite (HA) to β-tricalcium phosphate (β-TCP) ratio, Ca/P ratio and mean crystallite size was examined experimentally as well as through statistical analysis. MgHA nanopowders were synthesized by sol-gel technique at room temperature using aqueous solution of calcium nitrate tetrahydrate, magnesium nitrate hexahydrate and potassium dihydrogen phosphate as starting materials. The reaction time for sol-gel synthesis was varied between 15 to 60 minutes. Two process routes were followed with and without addition of triethanolamine (TEA) in the solutions. The elemental compositions of as-synthesized powders were determined using X-ray fluorescence (XRF) spectroscopy. The functional groups present in the as-synthesized MgHA nanopowders were established through Fourier Transform Infrared Spectroscopy (FTIR). The amounts of phases present, Ca/P ratio and mean crystallite sizes of MgHA nanopowders were determined using X-ray diffraction (XRD). The HA content in biphasic mixture of HA and β-TCP and Ca/P ratio in as-synthesized MgHA nanopowders increased effectively with reaction time of sols (p < 0.0001, two way Anova), however, these were independent of TEA addition (p > 0.15, two way Anova). The MgHA nanopowders synthesized with TEA assistance exhibited 14 nm lower crystallite size (p < 0.018, 2 sample t-test) compared to the powder synthesized without TEA assistance.

Keywords: capping agent, hydroxyapatite, regression analysis, sol-gel, 2- sample t-test, two-way analysis of variance (ANOVA)

Procedia PDF Downloads 364
12685 Green Amphiphilic Nanostructures from CNSL

Authors: Ermelinda Bloise, Giuseppe Mele

Abstract:

In recent years, Cashew Nut Shell Liquid (CNSL) has received great attention from researchers because it is an abundant waste material from the agri-food industry that fits perfectly into the idea of reusing waste from renewable resources for the production of new functional materials. The different components of this waste showed a certain chemical versatility and, above all, various biological activities. Take advantage of their surface-active capacity in particular conditions, various amphiphilic nanostructures have been prepared through sustainable chemical processes using cardanol (CA) and anacardic acid (AA) as two main components of the CNSL. In-batch solvent-free method has been developed to obtain new versatile green nanovesicles capable of effectively incorporating and stabilizing both hydrophobic and hydrophilic bioactive molecules. Furthermore, these nanosystems have shown antioxidant and cytotoxic properties and, in vitroinvestigations, established that they efficiently taken-up some human cells. With the idea of meeting the principles of green chemistry, even more, some improvements of the synthetic procedure have been implemented in terms of milder temperature and pH conditions, producing one-component nanovesicles, in which the AA and CA-derivatives are the sole building block of the green nanosystems. Finally, a new experimental approach has been carried out by a microfluidic route, with the advantage to operate at continuous flows, with a reduced amount of reagents, waste, and at lower temperatures, ensuring the achievement of size-monodisperse amphiphilic nanostructures that do not need further purification steps.

Keywords: bioactive nanosystems, bio-based renewables, cashew oil, green nanoformulations

Procedia PDF Downloads 83
12684 Periodontal Soft Tissue Sculpturing and Use of Interim Appliance for Rehabilitation of Anterior Edentulousness: Case Report

Authors: Hande Yesil, Seda Aycan Altan, M. Vehbi Bal, Alper Uyar, O. Cumhur Sipahi

Abstract:

Purpose: Fixed partial dentures (FPDs) must fulfill functional requirements such as phonetics, chewing efficiency and esthetics especially in the anterior region. A convex type tissue surface is usually recommended for pontics of FPDs. That pontic design also provides suitable oral hygiene and ease of cleaning. However, high esthetic requirements and correct emergence profile are not always achievable because of the convex shape of adjacent soft tissues. Therefore, the ovate type pontic which fulfills the high esthetic demands of the patients may be a good alternative to the modified ridge lap pontic design. Clinical Report: A female patient referred with the complaint of anterior upper edentulousness. In the oral examination it was determined that teeth 11, 12, 21, 22 were deficient. A thick and convex gingival tissue that may cause aesthetic problems was also observed.. Periodontal augmentation surgery was performed to ensure proper papillary configuration and gingival contour. An interim removable partial denture (IRPD) which applied pressure to operated gingival tissues was fabricated postoperatively. The IRPD was used for 4 weeks and after completion of tissue sculpting, the permanent FPD with an ovate pontic was fabricated and cemented. After a follow-up period of 6 months, not any esthetical and hygienic problem was detected and the patient was satisfied with her prosthesis. Conclusion: It was concluded that shaping of gingival contours with IRPD and use of a FPD with ovate pontic fulfills all esthetic and hygienic requirements.

Keywords: interim appliance, ovate pontic, tissue sculpturing, fixed partial denture

Procedia PDF Downloads 274
12683 Full-Scale Test of a Causeway Embankment Supported by Raft-Aggregate Column Foundation on Soft Clay Deposit

Authors: Tri Harianto, Lawalenna Samang, St. Hijraini Nur, Arwin

Abstract:

Recently, a port development is constructed in Makassar city, South Sulawesi Province, Indonesia. Makassar city is located in lowland area that dominated by soft marine clay deposit. A two kilometers causeway construction was built which is situated on the soft clay layer. In order to investigate the behavior of causeway embankment, a full-scale test was conducted of high embankment built on a soft clay deposit. The embankment with 3,5 m high was supported by two types of reinforcement such as raft and raft-aggregate column foundation. Since the ground was undergoing consolidation due to the preload, the raft and raft-aggregate column foundations were monitored in order to analyze the vertical ground movement by inducing the settlement of the foundation. In this study, two types of foundation (raft and raft-aggregate column) were tested to observe the effectiveness of raft-aggregate column compare to raft foundation in reducing the settlement. The settlement monitored during the construction stage by using the settlement plates, which is located in the center and toe of the embankment. Measurements were taken every day for each embankment construction stage (4 months). In addition, an analytical calculation was conducted in this study to compare the full-scale test result. The result shows that the raft-aggregate column foundation significantly reduces the settlement by 30% compared to the raft foundation. A raft-aggregate column foundation also reduced the time period of each loading stage. The Good agreement of analytical calculation compared to the full-scale test result also found in this study.

Keywords: full-scale, preloading, raft-aggregate column, soft clay

Procedia PDF Downloads 289