Search results for: characteristic method

Authors: Elena Kalcheva, Ahmad Taki, Yuri Hadi

Abstract:

Urban regeneration often includes residential high-rises as a way of optimum use of land. However, high-rises are in many cases connected to placelessness, this is not due to some intrinsic characteristic of the typology, but more to a failure to provide meaningful places in connection to them. The reason to study the Isle of the Dogs regeneration is the successful process that led to vibrant area with strong identity and social sustainability. Therefore, the purpose of this research is to identify the gaps into the sound strategy for the development of the area and in its implementation which will make the place more sustainable. The paper addresses four research questions: are the residential high-rises supporting a proper physical form; is there deployed properly scaled mix of land uses and functions in connection with residential high-rises; are there possible quality activities in quality places near the residential high-rises; and is there a strong sense of place created with the residential high-rise buildings and their surroundings. The methodology relies on observational survey of the researched area together with structured questions, to evaluate the external qualities of the residential high-rises and their surroundings. Visual information can help identify the mistakes and the omissions of the provided project examples. It can provide insight on how can be improved imageability, legibility and human scale. In this connection, the paper argues that although the quality of the architecture of the high-rises is superb, there is a failure to create meaningful, high quality public realm in connection with them. As such, it does not function as well as the designers intended to do: the functional quality of the public realm is quite low. The implications of the study suggest that actions need to take place in order to improve and foster further regeneration of the area.

Keywords: high-rises, isle of the dogs, public realm, regeneration

Procedia PDF Downloads 282

Authors: Aneta Binkowska, Grzegorz Michalak, Slawomir Pilip, Lukasz Bondaruk, Daniel Celinski, Robert Slotwinski

Abstract:

Post-traumatic mortality rates are still very high and show an increasing tendency. Early identification of patients at high risk of severe complications has a significant impact on treatment outcomes. The aim of the study was to better understand the early pathological inflammatory response to injury and infection and to determine the usefulness of the assessment of TNF-α and sTNFR1 concentrations in the peripheral blood as early indicators of severe post-traumatic complications. The study was carried out in a group of 51 patients after trauma treated in the ED, including 32 patients that met inclusion criteria for immunological analysis. Patients were divided into two groups using the ISS scale (group A with ISS ≥20, group B with ISS <20). Serum levels of TNF-α and sTNFR1 were determined after admission to the ED and after 3, 6, 12 and 24 hours. The highest TNF-α and sTNFR1 concentrations in both groups were recorded at admission and were significantly higher in group A compared to group B (A vs B TNF-α 2.46 pg/ml vs 1.78 pg/ml; sTNFR1 1667.5 pg/ml vs 875.2 p<0.005). The concentration of sTNFR1 in patients with severe complications was significantly higher compared to patients without complications and preceded clinical symptoms of complications ( C+ vs C- 1561.5 pg/ml vs 930.6 pg/ml). Spearman's correlation showed a statistically significant positive correlation between the baseline concentrations of IL-6 (r=0.38, p<0.043) and sTNFR1 (r=0.59, p=0.001) and the ISS scores. The high diagnostic sensitivity calculated from the ROC (receiver operating characteristic) curves was found for the concentrations of both cytokines: TNF α (AUC=0.91, p=0.004) and sTNFR1 (AUC=0.86, p=0.011). Elevated levels of sTNFR1, determined in the peripheral blood shortly after injury, is significantly associated with the occurrence of later complications, which in some patients lead to death. In contrast, high levels of TNF-α shortly after injury are associated with high mortality.

Keywords: cytokine, SIRS, MODS, trauma

Procedia PDF Downloads 163

Authors: Xiaohua Zou, Yongxin Su

Abstract:

The reasonable operation of heating, ventilation, and air conditioning (HVAC) is of great significance in improving the security, stability, and economy of power system operation. However, the uncertainty of the operating environment, thermal comfort varies by users and rapid decision-making pose challenges for HVAC demand response optimization. In this regard, this paper proposes a reinforcement learning-based method for HVAC demand response optimization considering few-shot personalized thermal comfort (PTC). First, an HVAC DR optimization framework based on few-shot PTC model and DRL is designed, in which the output of few-shot PTC model is regarded as the input of DRL. Then, a few-shot PTC model that distinguishes between awake and asleep states is established, which has excellent engineering usability. Next, based on soft actor criticism, an HVAC DR optimization algorithm considering the user’s PTC is designed to deal with uncertainty and make decisions rapidly. Experiment results show that the proposed method can efficiently obtain use’s PTC temperature, reduce energy cost while ensuring user’s PTC, and achieve rapid decision-making under uncertainty.

Keywords: HVAC, few-shot personalized thermal comfort, deep reinforcement learning, demand response

Procedia PDF Downloads 86

Authors: Yayun Hsu, Henry Horng-Shing Lu

Abstract:

This paper proposes a data-driven, biology-inspired neural segmentation method of 3D drosophila Brainbow images. We use Bayesian Sequential Partitioning algorithm for probabilistic modeling, which can be used to detect somas and to eliminate cross talk effects. This work attempts to develop an automatic methodology for neuron image segmentation, which nowadays still lacks a complete solution due to the complexity of the image. The proposed method does not need any predetermined, risk-prone thresholds since biological information is inherently included in the image processing procedure. Therefore, it is less sensitive to variations in neuron morphology; meanwhile, its flexibility would be beneficial for tracing the intertwining structure of neurons.

Keywords: brainbow, 3D imaging, image segmentation, neuron morphology, biological data mining, non-parametric learning

Procedia PDF Downloads 487

Authors: Muzaffar Iqbal, Essam Ezzeldin, Khalid A. Al-Rashood

Abstract:

Pomalidomide is a second generation oral immunomodulatory agent, being used for the treatment of multiple myeloma in patients with disease refractory to lenalidomide and bortezomib. In this study, a sensitive UPLC-MS/MS assay was developed and validated for high-throughput determination of pomalidomide in rat plasma using celecoxib as an internal standard (IS). Liquid liquid extraction using dichloromethane as extracting agent was employed to extract pomalidomide and IS from 200 µL of plasma. Chromatographic separation was carried on Acquity BEHTM C18 column (50 × 2.1 mm, 1.7 µm) using an isocratic mobile phase of acetonitrile:10 mM ammonium acetate (80:20, v/v), at a flow rate of 0.250 mL/min. Both pomalidomide and IS were eluted at 0.66 ± 0.03 and 0.80 ± 0.03 min, respectively with a total run time of 1.5 min only. Detection was performed on a triple quadrupole tandem mass spectrometer using electrospray ionization in negative mode. The precursor to product ion transitions of m/z 272.01 → 160.89 for pomalidomide and m/z 380.08 → 316.01 for IS were used to quantify them respectively, using multiple reaction monitoring mode. The developed method was validated according to regulatory guideline for bioanalytical method validation. The linearity in plasma sample was achieved in the concentration range of 0.47–400 ng/mL (r2 ≥ 0.997). The intra and inter-day precision values were ≤ 11.1% (RSD, %) whereas accuracy values ranged from - 6.8 – 8.5% (RE, %). In addition, other validation results were within the acceptance criteria and the method was successfully applied in a pharmacokinetic study of pomalidomide in rats.

Keywords: pomalidomide, pharmacokinetics, LC-MS/MS, celecoxib

Procedia PDF Downloads 391

Authors: Hazaila Binti Hassan, Abu Yazid Bin Abu Bakar, Salleh Amat

Abstract:

This study is to get the validity and reliability of the questionnaire for behaviour change on low-performing officers. This study aimed to develop and evaluate the behaviour of low performing officers. There are 75 items in this questionnaire which involves 5 subscales, which are the 5 dimensions intended to be studied: 1st emotional stability, 2nd psycho-spiritual enhancement, 3rd social skills development, 4th cognitive and rationality improvement and 5th behavioural alignment and adjustment. There are 2 processes in this research whereby to check the validity and reliability. Both use quantitative methods. Validity content testing has been conducted to validate the behavioural change questionnaire of the low performing officers. For the face validity, 4 people are involved, two are psychologists who carried out the program and the other two are officers of the same rank, i.e. supporting officers. They are involved in correction of sentences, languages, and grammar as well as the sentence structures so that it tallies with the purpose of studies. The questionnaire underwent content validity by the experts. Five experts are appointed to attend this session, 3 are directly involved in the construction of this questionnaire and 2 others are experts from the university with a background in questionnaire development. The result shows that the content validity obtained a high coefficient of 0.745 with a minimum and maximum value of more than 0.60 which satisfies the characteristic of Content Value Ratio. The Cronbach’s alpha result is 0.867. The highest scores are the behavioural alignment and adjustment sub-scale recorded the highest value, followed by social skills development sub-scale, cognitive and rational improvements sub-scale, psycho-spiritual enhancement sub-scale, and lastly emotional stability. Therefore, both of validity and reliability result were accepted that this questionnaire is valid and reliable can be used in the study of behaviour changes of low performing officers in the civil service.

Keywords: content validity, reliability, five dimension, low-performing officers, questionnaire

Procedia PDF Downloads 286

Authors: Saul A. Torres Z., Eduardo Liceaga C., Alfredo Arias M.

Abstract:

We seek to develop a UAV for agricultural spraying at a maximum altitude of 5000 meters above sea level, with a payload of 100 liters of fumigant. For the developing the aerodynamic design of the aircraft is using computational tools such as the "Vortex Lattice Athena" software, "MATLAB", "ANSYS FLUENT", "XFoil" package among others. Also methods are being used structured programming, exhaustive analysis of optimization methods and search. The results have a very low margin of error, and the multi-objective problems can be helpful for future developments. Also we developed method for Stability Analysis (Lateral-Directional and Longitudinal).

Keywords: aerodynamics design, optimization, algorithm genetic, multi-objective problem, longitudinal stability, lateral-directional stability

Procedia PDF Downloads 594

Authors: Timur S. Zaripov, Artur K. Gilfanov, Sergei S. Sazhin, Steven M. Begg, Morgan R. Heikal

Abstract:

The calculation of the concentration of inertial droplets in complex flows is encountered in the modelling of numerous engineering and environmental phenomena; for example, fuel droplets in internal combustion engines and airborne pollutant particles. The results of recent research, focused on the development of methods for calculating concentration and their implementation in the commercial CFD code, ANSYS Fluent, is presented here. The study is motivated by the investigation of the mixture preparation processes in internal combustion engines with direct injection of fuel sprays. Two methods are used in our analysis; the Fully Lagrangian method (also known as the Osiptsov method) and the Eulerian approach. The Osiptsov method predicts droplet concentrations along path lines by solving the equations for the components of the Jacobian of the Eulerian-Lagrangian transformation. This method significantly decreases the computational requirements as it does not require counting of large numbers of tracked droplets as in the case of the conventional Lagrangian approach. In the Eulerian approach the average droplet velocity is expressed as a function of the carrier phase velocity as an expansion over the droplet response time and transport equation can be solved in the Eulerian form. The advantage of the method is that droplet velocity can be found without solving additional partial differential equations for the droplet velocity field. The predictions from the two approaches were compared in the analysis of the problem of a dilute gas-droplet flow around an infinitely long, circular cylinder. The concentrations of inertial droplets, with Stokes numbers of 0.05, 0.1, 0.2, in steady-state and transient laminar flow conditions, were determined at various Reynolds numbers. In the steady-state case, flows with Reynolds numbers of 1, 10, and 100 were investigated. It has been shown that the results predicted using both methods are almost identical at small Reynolds and Stokes numbers. For larger values of these numbers (Stokes — 0.1, 0.2; Reynolds — 10, 100) the Eulerian approach predicted a wider spread in concentration in the perturbations caused by the cylinder that can be attributed to the averaged droplet velocity field. The transient droplet flow case was investigated for a Reynolds number of 200. Both methods predicted a high droplet concentration in the zones of high strain rate and low concentrations in zones of high vorticity. The maxima of droplet concentration predicted by the Osiptsov method was up to two orders of magnitude greater than that predicted by the Eulerian method; a significant variation for an approach widely used in engineering applications. Based on the results of these comparisons, the Osiptsov method has resulted in a more precise description of the local properties of the inertial droplet flow. The method has been applied to the analysis of the results of experimental observations of a liquid gasoline spray at representative fuel injection pressure conditions. The preliminary results show good qualitative agreement between the predictions of the model and experimental data.

Keywords: internal combustion engines, Eulerian approach, fully Lagrangian approach, gasoline fuel sprays, droplets and particle concentrations

Procedia PDF Downloads 257

Authors: Do-Jin Jang, Sung-Ah Kim

Abstract:

In designing a kinetic façade, it is hard for the designer to make digital models due to its complex geometry with motion. This paper aims to present a methodology of converting a point cloud of a physical model into a single digital model with a certain topology and motion. The method uses a Microsoft Kinect sensor, and color markers were defined and applied to three paper folding-inspired designs. Although the resulted digital model cannot represent the whole folding range of the physical model, the method supports the designer to conduct a performance-oriented design process with the rough physical model in the reduced folding range.

Keywords: design media, kinetic facades, tangible user interface, 3D scanning

Procedia PDF Downloads 413

Authors: Benjamin Kuester, Bjoern Eilert, Malte Stonis, Ludger Overmeyer

Abstract:

Increasing quality requirements make reliable and effective quality management indispensable. This includes the complaint handling in which the 8D method is widely used. The 8D report as a written documentation of the 8D method is one of the key quality documents as it internally secures the quality standards and acts as a communication medium to the customer. In practice, however, the 8D report is mostly faulty and of poor quality. There is no quality control of 8D reports today. This paper describes the use of natural language processing for the automated evaluation of 8D reports. Based on semantic analysis and text-mining algorithms the presented system is able to uncover content and formal quality deficiencies and thus increases the quality of the complaint processing in the long term.

Keywords: 8D report, complaint management, evaluation system, text-mining

Procedia PDF Downloads 315

Authors: Meiling Yang, Shuguo Xie, Yilong Zhu

Abstract:

Nowadays, due to diverse electric products and complex electromagnetic environment, the localization and troubleshooting of the electromagnetic radiation source is urgent and necessary especially on the condition of far field. However, based on the existing DOA positioning method, the system or devices are complex, bulky and expensive. To address this issue, this paper proposes a single antenna radiation source localization method. A single antenna moves to form a virtual antenna array combined with DOA and MUSIC algorithm to position accurately, meanwhile reducing the cost and simplify the equipment. As shown in the results of simulations and experiments, the virtual antenna array DOA estimation modeling is correct and its positioning is credible.

Keywords: virtual antenna array, DOA, localization, far field

Procedia PDF Downloads 372

Authors: Abdulsallam A. Bakdash, Aiyshah M. Alshehri, Hind M. Alenzi

Abstract:

Benzatropine (benztropine) is used to treat symptoms of Parkinson's disease or involuntary movements due to the side effects of certain psychiatric drugs. We report in this study, results of a procedure for the determination of benzatropine in hair using LLE, once with methanol and second with phosphate buffer (pH 6.0), followed by filtration and then re-extraction with dichloromethane. A GC/MS method was developed and validated for this determination using selected ion monitoring (SIM) detection without derivatization. Linearity established over the concentration range 0.1-20.0 ng/mg hair, and the correlation coefficients were greater than 0.99. Recoveries were 52.2% and 21.1% using methanol and phosphate buffer extraction, respectively. Detection limits of benzatropine in hair were between 0.65 and 3.0 ng/mg hair, while the accuracy were 10.4% and 18.5% (RSD), respectively. We also applied this method to the analysis of soaked hair samples and demonstrated that the LLE using methanol meets the requirement for the analysis of benzatropine in hair.

Keywords: hair analysis, benzatropine, liquid-liquid extraction, GC/MS

Procedia PDF Downloads 402

Authors: Shreya Poddar

Abstract:

Legal drafting and revising are recognized as highly demanding tasks for legal professionals. This paper introduces an approach to automate and refine these processes through the use of advanced Artificial Intelligence (AI). The method employs Large Language Models (LLMs), with a specific focus on 'Chain of Thoughts' (CoT) and knowledge injection via prompt engineering. This approach differs from conventional methods that depend on comprehensive training or fine-tuning of models with extensive legal knowledge bases, which are often expensive and time-consuming. The proposed method incorporates knowledge injection directly into prompts, thereby enabling the AI to generate more accurate and contextually appropriate legal texts. This approach substantially decreases the necessity for thorough model training while preserving high accuracy and relevance in drafting. Additionally, the concept of guardrails is introduced. These are predefined parameters or rules established within the AI system to ensure that the generated content adheres to legal standards and ethical guidelines. The practical implications of this method for legal work are considerable. It has the potential to markedly lessen the time lawyers allocate to document drafting and revision, freeing them to concentrate on more intricate and strategic facets of legal work. Furthermore, this method makes high-quality legal drafting more accessible, possibly reducing costs and expanding the availability of legal services. This paper will elucidate the methodology, providing specific examples and case studies to demonstrate the effectiveness of 'Chain of Thoughts' and knowledge injection in legal drafting. The potential challenges and limitations of this approach will also be discussed, along with future prospects and enhancements that could further advance legal work. The impact of this research on the legal industry is substantial. The adoption of AI-driven methods by legal professionals can lead to enhanced efficiency, precision, and consistency in legal drafting, thereby altering the landscape of legal work. This research adds to the expanding field of AI in law, introducing a method that could significantly alter the nature of legal drafting and practice.

Keywords: AI-driven legal drafting, legal automation, futureoflegalwork, largelanguagemodels

Procedia PDF Downloads 65

Authors: Weitao Lin

Abstract:

To quickly extract adequate information from large-scale unstructured text data, this paper studies the representation of events in Chinese scenarios and performs the regularized abstraction. It proposes a Chinese event detection technique based on dependency parsing and rule matching. The method first performs dependency parsing on the original utterance, then performs pattern matching at the word or phrase granularity based on the results of dependent syntactic analysis, filters out the utterances with prominent non-event characteristics, and obtains the final results. The experimental results show the effectiveness of the method.

Keywords: natural language processing, Chinese event detection, rules matching, dependency parsing

Procedia PDF Downloads 141

Authors: Anurag Gaur, Neha Sharma

Abstract:

In this work, we have synthesized BaTiO3 via sol gel method by sintering at different temperatures (600-1000 0C) and studied their structural, optical and ferroelectric properties through X-Ray diffraction (XRD), UV-Vis spectrophotometer and PE Loop Tracer. X-Ray diffraction patterns of barium titanate samples show that the peaks of the diffractogram are successfully indexed with the tetragonal structure of BaTiO3 along with some minor impurities of BaCO3. The optical band gap calculated through UV Visible spectrophotometer varies from 4.37 to 3.80 eV for the samples sintered at 600 to 1000 0 C, respectively. The particle size calculated through transmission electron microscopy varies from 20 to 60 nm for the samples sintered at 600 to 1000 0C, respectively. Moreover, it has been observed that the ferroelectricity reduces as we increase the sintering temperature.

Keywords: nanostructures, ferroelectricity, sol-gel method, diffractogram

Procedia PDF Downloads 427

Authors: Iva Košek Bartošová

Abstract:

There is great attention being paid in the field of development of first reading, thus early literacy skills in the Czech Republic. Yet inconclusive results of PISA and PIRLS force us to think over the teacher´s work, his/her roles in the education process and methods and forms used in lessons. There is also a significant importance to monitor the family environment and the pupil, themselves. The aim of the publishing output is to focus on one side dealing with methods of practicing reading technique and their results in the process of comprehension. In the first part of the contribution there are the goals of development of reading literacy and the methods used in reading practice in some EU countries and a follow-up comparison of research implemented by the help of modern technology of an eye tracker device in the year 2015 and a research conducted at the Institute of Education and Psychological Counselling of the Czech Republic in the year 2011/12. These are the results of a diagnostic test of reading in first classes of primary schools, taught by the genetic method and analytic-synthetic method. The results show that in the first stage of practice there are no statistically significant differences between any researched subjects taught by different methods of reading practice (with the use of several diagnostic texts focused on reading technique and its comprehension). Different results are shown at the end of Grade One and during Grade Two of primary school.

Keywords: elementary literacy, eye tracker device, diagnostic reading tests, reading teaching method

Procedia PDF Downloads 187

Authors: A. Azizi, M. Toubane, L. Chetibi

Abstract:

Differential scanning calorimetry (DSC) is a widely used technique for the study of phase transformations, particularly in the study of precipitation. The kinetic of the precipitation and dissolution is always related to the concept of activation energy Ea. The determination of the activation energy gives important information about the kinetic of the precipitation reaction. In this work, we were interested in the study of the isothermal and non-isothermal treatments on the decomposition of the supersaturated solid solution in the alloy AZ91 (Mg-9 Al-Zn 1-0.2 Mn. mass fraction %), using Differential Calorimetric method. Through this method, the samples were heat treated up to 425° C, using different rates. To calculate the apparent activation energies associated with the formation of precipitated phases, we used different isoconversional methods. This study was supported by other analysis: X-ray diffraction and microhardness measurements.

Keywords: calorimetric, activation energy, AZ91 alloys, microstructural evolution

Procedia PDF Downloads 440

Authors: Pradeepa Teegala, Ramreddy Chitteti

Abstract:

This article analyzes the mixed convection flow of chemically reacting micropolar fluid over a truncated cone embedded in non-Darcy porous medium with convective boundary condition. In addition, heat generation/absorption and Joule heating effects are taken into consideration. The similarity solution does not exist for this complex fluid flow problem, and hence non-similarity transformations are used to convert the governing fluid flow equations along with related boundary conditions into a set of nondimensional partial differential equations. Many authors have been applied the spectral quasi-linearization method to solve the ordinary differential equations, but here the resulting nonlinear partial differential equations are solved for non-similarity solution by using a recently developed method called the spectral quasi-linearization method (SQLM). Comparison with previously published work on special cases of the problem is performed and found to be in excellent agreement. The effect of pertinent parameters namely, Biot number, mixed convection parameter, heat generation/absorption, Joule heating, Forchheimer number, chemical reaction, micropolar and magnetic field on physical quantities of the flow are displayed through graphs and the salient features are explored in detail. Further, the results are analyzed by comparing with two special cases, namely, vertical plate and full cone wherever possible.

Keywords: chemical reaction, convective boundary condition, joule heating, micropolar fluid, mixed convection, spectral quasi-linearization method

Procedia PDF Downloads 277

Authors: Yuli Widiana

Abstract:

The study of implicature which is one of the discussions of pragmatics is an interesting and challenging topic to discuss. Implicature is a meaning which is implied in an utterance which is not the same as its literal meaning. The rapid development of information technology results in social networks as media to broadcast messages. The broadcast messages may be in the form of jokes which contain implicature. The research applies the pragmatic equivalent method to analyze the topics of jokes based on the implicatures contained in them. Furthermore, the method is also applied to reveal the purpose of creating implicature in jokes. The findings include the kinds of implicature found in jokes which are classified into conventional implicature and conversational implicature. Then, in detailed analysis, implicature in jokes is divided into implicature related to gender, culture, and social phenomena. Furthermore, implicature in jokes may not only be used to give entertainment but also to soften criticisms or satire so that it does not sound rude and harsh.

Keywords: implicature, broadcast messages, conventional implicature, conversational implicature

Procedia PDF Downloads 359

Authors: Mohd Suffian Yusoff, Noor Aina Mohamad Zuki, Mohd Faiz Muaz Ahmad Zamri

Abstract:

Currently, aluminium sulphate (alum), ferric chloride and polyaluminium chloride (PAC) are the most common coagulants being used for leachate coagulation-flocculation treatment. However, the impact of these residual’s coagulants have sparked huge concern ceaselessly. Therefore, development of natural coagulant as an alternative coagulant for treatment process has been given full attentions. In this attempt jackfruit seed starch (JSS) was produce by extraction method. The removal efficiency was determined using jar test method. The removal of organic matter and ammonia were compared between JSS used in powder form and diluted form in leachate. The yield of starch from the extraction method was 33.17 % with light brown in colour. The removal of turbidity was the highest at pH 8 for both diluted and powdered JSS with 38% and 8.7% of removal. While for colour removal the diluted JSS showed 18.19% of removal compared to powdered JSS. The diluted JSS also showed the highest removal of suspended solid with 3.5% compared to powdered JSS with 2.8%. Instead of coagulant, JSS as coagulant aid has succeed to reduce the dosage of PAC from 900 mg/L to 528 mg/L by maintaining colour and turbidity removal up to 94% and 92 % respectively. The JSS coagulant also has decreased the negative charge of the leachate nearly to the neutral charge (0.209 mv). The result proved that JSS was more effective to be used as coagulant aid landfill leachate treatment.

Keywords: landfill leachate, natural coagulant, jackfruit seed starch, coagulant

Procedia PDF Downloads 504

Authors: B. Soni, S. Biswas

Abstract:

Metal foams of Al find diverse applications in several industrial sectors such as in automotive and sports equipment industry as impact, acoustic and vibration absorbers, the aerospace industry as structural components in turbines and spatial cones, in the naval industry as low frequency vibration absorbers, and in construction industry as sound barriers inside tunnels, as fire proof materials and structure protection systems against explosions and even in heat exchangers, orthopedic components, and decorative items. Here, we report on the development of Al foams by a low cost and convenient technique of salt replication method with efficient control over size, geometry and distribution of the pores. Sodium bicarbonate was used as the foaming agent to form the porous refractory salt pattern. The mixed refractory salt slurry was microwave dried followed by sintering for selected time periods. Molten Al was infiltrated into the salt pattern in an inert atmosphere at a pressure of 2 bars. The final products were obtained by leaching out the refractory salt pattern. Mechanical properties of the derived samples were studied with a universal testing machine. The results were analyzed in correlation with their microstructural features evaluated with a scanning electron microscope (SEM).

Keywords: metal foam, Al, salt replication method, mechanical properties, SEM

Procedia PDF Downloads 354

Authors: M. Sasajima, T. Yamaguchi, Y. Hu, Y. Koike

Abstract:

In this paper, we discuss the propagation of sound in the narrow pathways of an occluded-ear simulator typically used for the measurement of insert-type earphones. The simulator has a standardized frequency response conforming to the international standard (IEC60318-4). In narrow pathways, the speed and phase of sound waves are modified by viscous air damping. In our previous paper, we proposed a new finite element method (FEM) to consider the effects of air viscosity in this type of audio equipment. In this study, we will compare the results from the ear simulator FEM model, and those from a three dimensional human ear canal FEM model made from computed tomography images, with the measured frequency response data from the ear canals of 18 people.

Keywords: ear simulator, FEM, viscosity, human ear canal

Procedia PDF Downloads 409

Authors: Thohaku Abdul Hadi, Hadyan Perdana Putra, Nugroho Wicaksono, Adhika Prajna Nandiwardhana, Onang Surya Nugroho, Heri Suryoatmojo, Soedibjo

Abstract:

Access to electricity is now a basic requirement of mankind. Unfortunately, there are still many places around the world which have no access to electricity, such as small islands, where there could potentially be a factory, a plantation, a residential area, or resorts. Many of these places might have substantial potential for energy generation such us Photovoltaic (PV) and Wind turbine (WT), which can be used to generate electricity independently for themselves. Solar energy and wind power are renewable energy sources which are mostly found in nature and also kinds of alternative energy that are still developing in a rapid speed to help and meet the demand of electricity. PV and Wind has a characteristic of power depend on solar irradiation and wind speed based on geographical these areas. This paper presented a control methodology of hybrid small scale PV/Wind energy system that use a fuzzy logic controller (FLC) to extract the maximum power point tracking (MPPT) in different solar irradiation and wind speed. This paper discusses simulation and analysis of the generation process of hybrid resources in MPP and power conditioning unit (PCU) of Photovoltaic (PV) and Wind Turbine (WT) that is connected to the three-phase low voltage electricity grid system (380V) without battery storage. The capacity of the sources used is 2.2 kWp PV and 2.5 kW PMSG (Permanent Magnet Synchronous Generator) -WT power rating. The Modeling of hybrid PV/Wind, as well as integrated power electronics components in grid connected system, are simulated using MATLAB/Simulink.

Keywords: fuzzy MPPT, grid connected inverter, photovoltaic (PV), PMSG wind turbine

Procedia PDF Downloads 355

Authors: Sina Saadati, Mohammadreza Razzazi

Abstract:

In this article, we have tried to present an agent-based model of human muscle. A suitable model of muscle is necessary for the analysis of mankind's movements. It can be used by clinical researchers who study the influence of motion sicknesses, like Parkinson's disease. It is also useful in the development of a prosthesis that receives the electromyography signals and generates force as a reaction. Since we have focused on computational efficiency in this research, the model can compute the calculations very fast. As far as it concerns prostheses, the model can be known as a charge-efficient method. In this paper, we are about to illustrate an agent-based model. Then, we will use it to simulate the human gait cycle. This method can also be done reversely in the analysis of gait in motion sicknesses.

Keywords: agent-based modeling and simulation, human muscle, gait cycle, motion sickness

Procedia PDF Downloads 114

Authors: Raj Nandkeolyar, Precious Sibanda

Abstract:

The flow of a viscous, incompressible, and electrically conducting fluid under the influence of aligned magnetic field acting along the direction of fluid flow over an exponentially stretching sheet is investigated numerically. The nonlinear partial differential equations governing the flow model is transformed to a set of nonlinear ordinary differential equations using suitable similarity transformation and the solution is obtained using a local linearization method followed by the Chebyshev spectral collocation method. The effects of various parameters affecting the flow and heat transfer as well as the induced magnetic field are discussed using suitable graphs and tables.

Keywords: aligned magnetic field, exponentially stretching sheet, induced magnetic field, magnetohydrodynamic flow

Procedia PDF Downloads 454

Authors: Jelena R. Pejović, Nina N. Serdar

Abstract:

This paper presents an analysis of the “Performance-Based” seismic design method, in order to overcome the perceived disadvantages and limitations of the existing seismic design approach based on force, in engineering practice. Bearing in mind, the specificity of the earthquake as a load and the fact that the seismic resistance of the structures solely depends on its behaviour in the nonlinear field, traditional seismic design approach based on force and linear analysis is not adequate. “Performance-Based” seismic design method is based on nonlinear analysis and can be used in everyday engineering practice. This paper presents the application of this method to eight-story high reinforced concrete building with combined structural system (reinforced concrete frame structural system in one direction and reinforced concrete ductile wall system in other direction). The nonlinear time-history analysis is performed on the spatial model of the structure using program Perform 3D, where the structure is exposed to forty real earthquake records. For considered building, large number of results were obtained. It was concluded that using this method we could, with a high degree of reliability, evaluate structural behavior under earthquake. It is obtained significant differences in the response of structures to various earthquake records. Also analysis showed that frame structural system had not performed well at the effect of earthquake records on soil like sand and gravel, while a ductile wall system had a satisfactory behavior on different types of soils.

Keywords: ductile wall, frame system, nonlinear time-history analysis, performance-based methodology, RC building

Procedia PDF Downloads 366

Authors: F. T. Senberber, N. Tugrul, E. Moroydor Derun

Abstract:

As a nutraceutical, sumac (Rhus Coriaria) was extracted by using different solvents of methanol, ethanol, and water. The DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) method of free radical scavenging capacity was used to determine the effects of solvent on antioxidant activities of the plant. The total phenolic content was studied by The Folin Ciocalteu Reagent method. The antioxidant activities of extracts exhibit minor changes in different solvents and varied in the range of 84.3–86.4 %. The total phenolic contents are affected by the selected solvent. The highest total phenolic content was determined at the liquid phase of water and it was estimated as 26.3 mg/g in gallic acid.

Keywords: DPPH, solvent, sumac, total phenolic content

Procedia PDF Downloads 153

Authors: Varvara Roubtsova, Mohamed Chekired

Abstract:

Recent studies on the numerical simulation of geotechnical problems show the importance of considering the soil micro-structure. At this scale, soil is a discrete particle medium where the particles can interact with each other and with water flow under external forces, structure loads or natural events. This paper presents research conducted in a virtual laboratory named SiGran, developed at IREQ (Institut de recherche d’Hydro-Quebec) for the purpose of investigating a broad range of problems encountered in geotechnics. Using Discrete Element Method (DEM), SiGran simulated granular materials directly by applying Newton’s laws to each particle. The water flow was simulated by using Marker and Cell method (MAC) to solve the full form of Navier-Stokes’s equation for non-compressible viscous liquid. In this paper, examples of numerical simulation and their comparisons with real experiments have been selected to show the complexity of geotechnical research at the micro level. These examples describe transient flows into a porous medium, interaction of particles in a viscous flow, compacting of saturated and unsaturated soils and the phenomenon of liquefaction under seismic load. They also provide an opportunity to present SiGran’s capacity to compute the distribution and evolution of energy by type (particle kinetic energy, particle internal elastic energy, energy dissipated by friction or as a result of viscous interaction into flow, and so on). This work also includes the first attempts to apply micro discrete results on a macro continuum level where the Smoothed Particle Hydrodynamics (SPH) method was used to resolve the system of governing equations. The material behavior equation is based on the results of simulations carried out at a micro level. The possibility of combining three methods (DEM, MAC and SPH) is discussed.

Keywords: discrete element method, marker and cell method, numerical simulation, multi-scale simulations, smoothed particle hydrodynamics

Procedia PDF Downloads 302

Authors: Mary L. G. S. Senna, Afonso R. Aquino

Abstract:

The development of tourism causes negative impacts on the environment. It is in this context, through the Ecological Footprint (EF) method that this study aimed to characterize the impacts of ecotourism on the community of Mateiros, Jalapão, Brazil. The EF, which consisted in its original a method to construct a land use matrix, considering some major categories of human consumption such as food, housing, transportation, consumer goods and services, and six other categories from the main land use which are divided into the topics: land use, degraded environment, gardens, fertile land, pasture and forests protected by the government. The main objective of this index is to calculate the land area required for the production and maintenance of goods and services consumed by a community. The field research was conducted throughout the year of 2014 until July 2015. After the calculations of each category, these components were added according to the presented method in order to determine the annual EF of the tourism sector in Mateiros. The results show that the EF resulting from tourism in Mateiros is 2,194.22 hectares of land required for tourism activities in the region. The EF of tourism was considered high, nevertheless, if it is added the total of hectares needed annually for tourism activities, the result found would be 2,194.22 hectares needed to absorb the CO₂ emissions generated in the region directly from the tourism sector.

Keywords: sustainable tourism, tourism ecological footprint, Jalapão/TO/Brazil

Procedia PDF Downloads 327

Authors: Hanbey Hazar, Hakan Gul, Ugur Ozturk

Abstract:

In order to decrease the hazardous emissions of the internal combustion engines and to improve the combustion and thermal efficiency, thermal barrier coatings are applied. In this experimental study, cylinder, piston, exhaust, and inlet valves which are combustion chamber components have been coated with a ceramic material, and this earned the engine LHR feature. Cylinder, exhaust and inlet valves of the diesel engine used in the tests were coated with ekabor-2 commercial powder, which is a ceramic material, to a thickness of 50 µm, by using the boriding method. The piston of a diesel engine was coated in 300 µm thickness with bor-based powder by using plasma coating method. Pumpkin seeds oil methyl ester (PSME) was produced by the transesterification method. In addition, dimethoxymethane additive materials were used to improve the properties of diesel fuel, pumpkin seeds oil methyl ester (PSME) and its mixture. Dimethoxymethane was blended with test fuels, which was used as a pilot fuel, at the volumetric ratios of 4% and 8%. Due to thermal barrier coating, the diesel engine's CO, HC, and smoke density values decreased; but, NOx and exhaust gas temperature (EGT) increased.

Keywords: boriding, diesel engine, exhaust emission, thermal barrier coating

Procedia PDF Downloads 477