Search results for: passive dampers

Authors: Zhou Xiaowen China, Zhang Sanming China

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Neighbourhood space as a very important part of city spaces, is an organic combination of material environment and spiritual achievement in people’ daily life, and has a real impact upon the sustainable development of the whole city. Looking back on the past 2014 World Architecture Festival (WAF), 4 out of 35winning buildings were neighbourhood designs, and all of them mentioned about space-sharing and sustainable development. In this paper, three award-winning cases were studied, including the world building of the year—the chapel (Vietnam, A21 studio), The Carve (Norway, A-Lab) and House for Trees (Vietnam, Vo Trong Nghia Architects). Urban context, planning, space construction and sustainable technology were discussed. Based on those, it was discovered that passive energy-saving technologies have been paid more and more attention, sharing space has been designed ingeniously, and the architectural forms of them reflect social inclusion and equity. This paper is aimed at summarizing the excellent works on the Festival and providing reference for the future design.

Keywords: neighbourhood design, 2014 World Architecture Festival (WAF), sustainable development, space-sharing

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Authors: Caroline Jones

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Research over the last decade suggests that there have been distinct changes in both women’s sexual behaviour and attitudes towards female sexuality in the UK. Areas such as discussing sex, participating in sexual activity outside of traditional monogamous relationships, and engaging in boudoir photography have all been explored by researchers. Women’s participation in tantric practices, however, is a relatively unexplored area of sexuality, despite an increasing number of Tantra schools opening in the UK. Tantra is a practice in which women are considered to have a higher consciousness than men, where the sexual role of women is deemed to be very different to a traditional Western sexually passive role. This research looks at this area, and is based on in-depth, semi-structured, thematically analysed interviews with women who have participated in tantric workshops and/or retreats across the country. The interviews investigate why women engage with such practices, what they feel they gain from the experience, and how shifting notions of appropriate sexual roles for women impact on their sexuality and life generally. While Tantra is still a minority activity in the UK, the findings shed light on not only these areas but also on women’s constructions of their sexuality, their relationships with their bodies and sexualities, and ways in which they express and engage with changing notions of female sexuality.

Keywords: sexuality, Tantra, gender, Shakti

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Authors: Sajjad Ahmed, Knut Hinkelmann, Flavio Corradini

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Fake news detection research is still in the early stage as this is a relatively new phenomenon in the interest raised by society. Machine learning helps to solve complex problems and to build AI systems nowadays and especially in those cases where we have tacit knowledge or the knowledge that is not known. We used machine learning algorithms and for identification of fake news; we applied three classifiers; Passive Aggressive, Naïve Bayes, and Support Vector Machine. Simple classification is not completely correct in fake news detection because classification methods are not specialized for fake news. With the integration of machine learning and text-based processing, we can detect fake news and build classifiers that can classify the news data. Text classification mainly focuses on extracting various features of text and after that incorporating those features into classification. The big challenge in this area is the lack of an efficient way to differentiate between fake and non-fake due to the unavailability of corpora. We applied three different machine learning classifiers on two publicly available datasets. Experimental analysis based on the existing dataset indicates a very encouraging and improved performance.

Keywords: fake news detection, natural language processing, machine learning, classification techniques.

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Authors: Mohsen Yaghmoor, Sima Radmanesh, Ameneh Gholami

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Cities are the principal ground for manifestation of an information society. To create an entrepreneurial city, it is required that just and equal access to opportunities are provided for all segments of the city and technologies are intelligently employed. Furthermore, it is necessary for us to be electronically ready in all political, economic, social, cultural, and technological aspects. Also e-city creates enormous potentials and opportunities for development of the entrepreneurial city. After improvement of e-readiness for establishment of entrepreneurial e-city, potentials, and capitals of the city become productive and more suitable opportunities are offered to citizens, state sectors, and private sectors in order to become entrepreneurs. To create and develop an entrepreneurial city, we need to have readiness to detection and creation of entrepreneurial opportunities and finally exploitation of these opportunities which, in turn, lead to use of entrepreneurial events and their quality in the city. In this model, the quality of entrepreneurial events, the productivity of activities, the necessity of reducing the digital gap, positive and active attendance in information society and compatibility and aligning with the global society are emphasized. In an entrepreneurial city, citizens are not help seekers, private sector is not passive, and the government is entrepreneurial.

Keywords: e-city, e-readiness, entrepreneurial city, entrepreneurial events, technological entrepreneurship

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Authors: Eusebio Jr. Lina, Ederlina Nocon

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Cyclic codes are a fundamental subclass of linear codes that enjoy a very interesting algebraic structure. The class of skew cyclic codes (or θ-cyclic codes) is a generalization of the notion of cyclic codes. This a very large class of linear codes which can be used to systematically search for codes with good properties. A linear code with complementary dual (LCD code) is a linear code C satisfying C ∩ C^⊥ = {0}. This subclass of linear codes provides an optimum linear coding solution for a two-user binary adder channel and plays an important role in countermeasures to passive and active side-channel analyses on embedded cryptosystems. This paper aims to identify LCD codes from the class of skew cyclic codes. Let F_q be a finite field of order q, and θ be an automorphism of F_q. Some conditions for a skew cyclic code to be LCD were given. To this end, the properties of a noncommutative skew polynomial ring F_q[x, θ] of automorphism type were revisited, and the algebraic structure of skew cyclic code using its skew polynomial representation was examined. Using the result that skew cyclic codes are left ideals of the ring F_q[x, θ]/〈x^n-1〉, a characterization of a skew cyclic LCD code of length n was derived. A necessary condition for a skew cyclic code to be LCD was also given.

Keywords: LCD cyclic codes, skew cyclic LCD codes, skew cyclic complementary dual codes, theta-cyclic codes with complementary duals

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Authors: Amirreza Niktash, B. P. Huynh

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A windcatcher is a structure fitted on the roof of a building for providing natural ventilation by using wind power; it exhausts the inside stale air to the outside and supplies the outside fresh air into the interior space of the building working by pressure difference between outside and inside of the building and using ventilation principles of passive stacks and wind tower, respectively. In this paper, the effect of different heights of inlet/outlets’ ducts of a two-sided windcatcher on the flow rate, flow velocity and flow pattern through a three-dimensional room fitted with the windcatcher are investigated and analysed by using RANS CFD technique and applying standard K-ε turbulence model via a commercial computational fluid dynamics (CFD) software package. The achieved results show that the inlet/outlet ducts height strongly affects flow rate, flow velocity and flow pattern especially in the living area of the room when the wind velocity is not too low. The results are confirmed by the experimental test for constructed scaled model in the laboratory and it develops the two-sided windcatcher’s performance in ventilation applications.

Keywords: CFD, RANS, ventilation, windcatcher

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Authors: Madhu Sudan, G. N. Tiwari

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In this paper, an attempt has been made to analyze the effect of wall window orientation on Daylight Illuminance Ratio (DIR) and energy saving in a building known as “SODHA BERS COMPLEX (SBC)” at Varanasi, UP, India. The building has been designed incorporating all passive concepts for thermal comfort as well daylighting concepts to maximize the use of natural daylighting for the occupants in the day to day activities. The annual average DIR and the energy saving has been estimated by using the DIR model for wall window with different orientations under clear sky condition. It has been found that for south oriented window the energy saving per square meter is more compared to the other orientations due to the higher level of solar insolation for the south window in northern hemisphere whereas energy saving potential is minimum for north oriented wall window. The energy saving potential was 26%, 81% and 51% higher for east, south and west oriented window in comparison to north oriented window. The average annual DIR has same trends of variation as the annual energy saving and it is maximum for south oriented window and minimum for north oriented window.

Keywords: clear sky, daylight factor, energy saving, wall window

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Authors: Nagaraju Pendam, C. P. Vardhani

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A simple technology–compatible design of silicon-on-insulator based 1×2 optical power splitter is proposed. For developing large area Opto-electronic Silicon-on-Insulator (SOI) devices, the power splitter is a key passive device. The SOI rib- waveguide dimensions (height, width, and etching depth, refractive indices, length of waveguide) leading simultaneously to single mode propagation. In this paper a low loss optical power splitter is designed by using R Soft cad tool and simulated by Beam propagation method, here s-bend waveguides proposed. We concentrate changing the refractive index difference, branching angle, width of the waveguide, free space wavelength of the waveguide and observing transmitted power, effective refractive index in the designed waveguide, and choosing the best simulated results to be fabricated on silicon-on insulator platform. In this design 1550 nm free spacing are used.

Keywords: beam propagation method, insertion loss, optical power splitter, rib waveguide, transmitted power

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Authors: A. Casale, J. Alessi, C. N. Bianchi, G. Bozzini, M. Brunoldi, V. Cappanera, P. Corvisiero, G. Fanciulli, D. Grosso, N. Magnoli, A. Mandich, C. Melchiorre, C. Morri, P. Povero, N. Stasi, M. Taiuti, G. Viano, M. Wurtz

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This work describes a real-time algorithm for detecting, tracking and classifying single motorboats, developed using the acoustic data recorded by a hydrophone array within the framework of EU LIFE + project ARION (LIFE09NAT/IT/000190). The project aims to improve the conservation status of bottlenose dolphins through a real-time simultaneous monitoring of their population and surface ship traffic. A Passive Acoustic Monitoring (PAM) system is installed on two autonomous permanent marine buoys, located close to the boundaries of the Marine Protected Area (MPA) of Portofino (Ligurian Sea- Italy). Detecting surface ships is also a necessity in many other sensible areas, such as wind farms, oil platforms, and harbours. A PAM system could be an effective alternative to the usual monitoring systems, as radar or active sonar, for localizing unauthorized ship presence or illegal activities, with the advantage of not revealing its presence. Each ARION buoy consists of a particular type of structure, named meda elastica (elastic beacon) composed of a main pole, about 30-meter length, emerging for 7 meters, anchored to a mooring of 30 tons at 90 m depth by an anti-twist steel wire. Each buoy is equipped with a floating element and a hydrophone tetrahedron array, whose raw data are send via a Wi-Fi bridge to a ground station where real-time analysis is performed. Bottlenose dolphin detection algorithm and ship monitoring algorithm are operating in parallel and in real time. Three modules were developed and commissioned for ship monitoring. The first is the detection algorithm, based on Time Difference Of Arrival (TDOA) measurements, i.e., the evaluation of angular direction of the target respect to each buoy and the triangulation for obtaining the target position. The second is the tracking algorithm, based on a Kalman filter, i.e., the estimate of the real course and speed of the target through a predictor filter. At last, the classification algorithm is based on the DEMON method, i.e., the extraction of the acoustic signature of single vessels. The following results were obtained; the detection algorithm succeeded in evaluating the bearing angle with respect to each buoy and the position of the target, with an uncertainty of 2 degrees and a maximum range of 2.5 km. The tracking algorithm succeeded in reconstructing the real vessel courses and estimating the speed with an accuracy of 20% respect to the Automatic Identification System (AIS) signals. The classification algorithm succeeded in isolating the acoustic signature of single vessels, demonstrating its temporal stability and the consistency of both buoys results. As reference, the results were compared with the Hilbert transform of single channel signals. The algorithm for tracking multiple targets is ready to be developed, thanks to the modularity of the single ship algorithm: the classification module will enumerate and identify all targets present in the study area; for each of them, the detection module and the tracking module will be applied to monitor their course.

Keywords: acoustic-noise, bottlenose-dolphin, hydrophone, motorboat

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Authors: Amani Amamou, Sabra Habli, Nejla Mahjoub Saïd, Philippe Bournot, Georges Le Palec

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A counterflowing jet is a particular configuration of turbulent jets issuing into a moving ambient which has not carried much attention in literature compared with jet in a coflow or in a crossflow. This is due to the marked instability of the jet in a counterflow coupled with experimental and theoretical difficulties related to the flow inversion phenomenon. Nevertheless, jets in a counterflow are encountered in many engineering applications which required enhanced mixing as combustion, process and environmental engineering. In this work, we propose to investigate a round turbulent jet flowing into a uniform counterflow stream through a numerical approach. A hydrodynamic and thermal study of a slightly oblique round jets issuing into a uniform counterflow stream is carried out for different jet-to-counterflow velocity ratios ranging between 3.1 and 15. It is found that even a slight inclination of the jet in the vertical direction of the flow affects the structure and the velocity field of the counterflowing jet. In addition, the evolution of passive scalar temperature and pertinent length scales are presented at various velocity ratios, confirming that the flow is sensitive to directional perturbations.

Keywords: jet, counterflow, velocity, temperature, jet inclination

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Authors: Sarah Fitzpatrick, Hossein Zare-Behtash, Konstantinos Kontis

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Traditionally, the focus of horizontal axis wind turbine (HAWT) blade aerodynamic optimisation studies has been the outer working region of the blade. However, recent works seek to better understand, and thus improve upon, the performance of the inboard blade region to enhance power production, maximise load reduction and better control the wake behaviour. This paper presents the design considerations and characterisation of a wind turbine wind tunnel model devised to further the understanding and fundamental definition of horizontal axis wind turbine root vortex shedding and interactions. Additionally, the application of passive and active flow control mechanisms – vortex generators and plasma actuators – to allow for the manipulation and mitigation of unsteady aerodynamic behaviour at the blade inboard section is investigated. A static, modular blade wind turbine model has been developed for use in the University of Glasgow’s de Havilland closed return, low-speed wind tunnel. The model components - which comprise of a half span blade, hub, nacelle and tower - are scaled using the equivalent full span radius, R, for appropriate Mach and Strouhal numbers, and to achieve a Reynolds number in the range of 1.7x105 to 5.1x105 for operational speeds up to 55m/s. The half blade is constructed to be modular and fully dielectric, allowing for the integration of flow control mechanisms with a focus on plasma actuators. Investigations of root vortex shedding and the subsequent wake characteristics using qualitative – smoke visualisation, tufts and china clay flow – and quantitative methods – including particle image velocimetry (PIV), hot wire anemometry (HWA), and laser Doppler anemometry (LDA) – were conducted over a range of blade pitch angles 0 to 15 degrees, and Reynolds numbers. This allowed for the identification of shed vortical structures from the maximum chord position, the transitional region where the blade aerofoil blends into a cylindrical joint, and the blade nacelle connection. Analysis of the trailing vorticity interactions between the wake core and freestream shows the vortex meander and diffusion is notably affected by the Reynold’s number. It is hypothesized that the shed vorticity from the blade root region directly influences and exacerbates the nacelle wake expansion in the downstream direction. As the design of inboard blade region form is, by necessity, driven by function rather than aerodynamic optimisation, a study is undertaken for the application of flow control mechanisms to manipulate the observed vortex phenomenon. The designed model allows for the effective investigation of shed vorticity and wake interactions with a focus on the accurate geometry of a root region which is representative of small to medium power commercial HAWTs. The studies undertaken allow for an enhanced understanding of the interplay of shed vortices and their subsequent effect in the near and far wake. This highlights areas of interest within the inboard blade area for the potential use of passive and active flow control devices which contrive to produce a more desirable wake quality in this region.

Keywords: vortex shedding, wake interactions, wind tunnel model, wind turbine

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Authors: Kaushalendra K. Khadanga, Lee Hee Hyol

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Passenger comfort has been paramount in the design of suspension systems of high speed cars. To analyze the effect of vibration on vehicle ride quality, a vertical model of a six degree of freedom railway passenger vehicle, with front and rear suspension, is built. It includes car body flexible effects and vertical rigid modes. A second order linear shaping filter is constructed to model Gaussian white noise into random rail excitation. The temporal correlation between the front and rear wheels is given by a second order Pade approximation. The complete track and the vehicle model are then designed. An active secondary suspension system based on a Linear Quadratic Gaussian (LQG) optimal control method is designed. The results show that the LQG control method reduces the vertical acceleration, pitching acceleration and vertical bending vibration of the car body as compared to the passive system.

Keywords: active suspension, bending vibration, railway vehicle, vibration control

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Authors: Soufi Saylam

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Environmental concerns, rising consumption of energy, and the high cost of mechanical systems have all contributed to increased interest in building energy efficiency and passive thermal design in recent years. This study attempts to make an evaluation of building envelope components and associated retrofits in terms of their impact on energy efficiency and occupant comfort in a sustainable context. The design of the building envelope, as a critical component of the building, has a significant impact on the organization of interior space and user comfort. In this regard, in order to achieve maximum comfort and energy savings, the design of the building envelope should include a thermal comfort system that adapts to climatic variables. This system should be developed in harmony with the environmental features, building shape, and materials used. The aim of this study is to investigate the role of the building envelope in sustainable architecture by integrating traditional envelope design principles and strategies with technological techniques, as well as to examine its role in providing physical and psychological comfort to users in the interior space.

Keywords: envelope design, functional needs, physiological comfort, sustainable architecture, traditional techniques

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Authors: Vipulkumar Jagodana

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Recently the use of renewable sources has increased, these sources include fuel cell, photo voltaic, and wind turbine. Islanding occurs when one portion of grid is isolated from remaining grid. Use of the renewable sources can provide continuous power to isolated portion in islanding condition. One of the common renewable sources is wind generation using wind turbine. The efficiency of wind generation can be increased in combination with conventional sources. When islanding occurs, few parameters change which may be frequency, voltage, active power, and harmonics. According to large change in one of these parameters islanding is detected. In this paper, two passive methods Rate of Change of Frequency (ROCOF) and Rate of change of Power (ROCOP) have been implemented for islanding detection of small wind-turbine. Islanding detection of both methods have been simulated in PSCAD. Simulation results show at different islanding inception angle response of ROCOF and ROCOP.

Keywords: islanding, adopted methods, PSCAD simulation, comparison

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Authors: Sawsan M. H. Domi

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Approximately 50% of the energy used in buildings, including houses, provide environmental comfortable levels of thermal living. In Khartoum - the city under study- cooling uses the largest portion of energy and the basic idea of Low energy houses is to minimize energy consumption. Therefore, houses are designed to use natural climate strategies to provide thermal comfort. Strategies such as semi-open spaces, shading devices, small high windows and thick walls. The study aims to review these strategies and then, apply them. It aims to change house microclimate by using vegetation, green areas, and other components. A low energy house is being designed s. It will be the first low energy house in Khartoum designed to create a low-cost energy efficient building without any mechanical systems. Three different types of houses in Khartoum are examined and evaluated according to their energy loads which provides the basis for the designed house. The designed house uses passive design strategies to reduce the need for cooling. These results show that the house reduced energy cooling loads by more than 60% compared to the average of the three given types. The design house is economically viable when taking into consideration the energy prices in Sudan.

Keywords: building envelope, climate, energy loads, ventilation

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Authors: Muhammad Nauman Ahmad, Patrick Büker, Sofia Khalid, Leon Van Den Berg, Hamid Ullah Shah, Abdul Wahid, Lisa Emberson, Sally A. Power, Mike Ashmore

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Although ozone is well-documented to affect crop yields in the densely populated Indo-Gangetic Plain, there is little knowledge of its effects around cities in more remote areas of South Asia. We surveyed crops around the city of Peshawar, Pakistan for visible injury, linking this to passive measurements of ozone concentrations. Foliar injury was found in the field on potato, onion and cotton when the mean monthly ozone concentration reached 35-55ppb. The symptoms on onion were reproduced in ozone fumigation experiments, which also showed that daytime ozone concentrations of 60ppb and above significantly reduce the growth of Pakistani varieties of both spinach (Beta vulgaris) and onion. Aphid infestation on spinach was also reduced at these elevated ozone concentrations. The ozone concentrations in Peshawar are comparable to those through many parts of northern south Asia, where ozone may therefore be a significant threat to sensitive vegetable crops in peri-urban regions.

Keywords: ozone, air pollution, vegetable crops, peshawar, south asia

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Authors: Mohan L. Jayatiake, Judd Storrs, Jing-Huei Lee

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The optimal MRI resolution relies on a homogeneous magnetic field. However, local susceptibility variations can lead to field inhomogeneities that cause artifacts such as image distortion and signal loss. The effects of local susceptibility variation notoriously increase with magnetic field strength. Active shimming improves homogeneity by applying corrective fields generated from shim coils, but requires calculation of optimal current for each shim coil. FASTMAP (fast automatic shimming technique by mapping along projections) is an effective technique for finding optimal currents works well at high-field, but is restricted to shimming spherical regions of interest. The 3D gradient-echo pulse sequence was modified to reduce sensitivity to eddy currents and used to obtain susceptibility field maps at 4T. Measured fields were projected onto first-and second-order spherical harmonic functions corresponding to shim hardware. A spherical phantom was used to calibrate the shim currents. Susceptibility maps of a volunteer’s brain with and without FASTMAP shimming were obtained. Simulations indicate that optimal shim currents derived from the field map may provide better overall shimming of the human brain.

Keywords: shimming, high-field, active, passive

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Authors: M. Panahian

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A global challenge which is of paramount significance today is the issue of devising innovative solutions to tackle the environmental issues, as well as more intelligent and foresightful consumption of and management of natural resources. Changes in global climate resulting from the burning of fossil fuel and the rise in the level of energy consumption are a few examples of environmental issues detrimental to any form of life on earth, which are aggravated year by year. Overall, energy-efficient designs and construction strategies can be studied at three scales: building, block, and city. Nevertheless, as the available literature suggests, the greatest emphasis has been on building and city scales, and little has been done as to the energy-efficient designs at block scale. Therefore, the aim of the current research is to investigate the influences of residential block scale envelope on the energy consumption in buildings. To this end, a case study of residential block scale has been selected in the city of Isfahan, in Iran, situated in a hot and dry climate with cold winters. Eventually, the most effective variables in energy consumption, concerning the block scale envelope, will be concluded.

Keywords: sustainability, passive energy saving solutions, residential block scale, energy efficiency

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Authors: Jose Neri, Fabrice Canto, Alastair Magnaldo, Laurent Guillerme, Vincent Dugas

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A miniaturized and automated approach for the volumetric titration of free nitric acid in U(VI) solutions is presented. Free acidity measurement refers to the acidity quantification in solutions containing hydrolysable heavy metal ions such as U(VI), U(IV) or Pu(IV) without taking into account the acidity contribution from the hydrolysis of such metal ions. It is, in fact, an operation having an essential role for the control of the nuclear fuel recycling process. The main objective behind the technical optimization of the actual ‘beaker’ method was to reduce the amount of radioactive substance to be handled by the laboratory personnel, to ease the instrumentation adjustability within a glove-box environment and to allow a high-throughput analysis for conducting more cost-effective operations. The measurement technique is based on the concept of the Taylor-Aris dispersion in order to create inside of a 200 μm x 5cm circular cylindrical micro-channel a linear concentration gradient in less than a second. The proposed analytical methodology relies on the actinide complexation using pH 5.6 sodium oxalate solution and subsequent alkalimetric titration of nitric acid with sodium hydroxide. The titration process is followed with a CCD camera for fluorescence detection; the neutralization boundary can be visualized in a detection range of 500nm- 600nm thanks to the addition of a pH sensitive fluorophore. The operating principle of the developed device allows the active generation of linear concentration gradients using a single cylindrical micro channel. This feature simplifies the fabrication and ease of use of the micro device, as it does not need a complex micro channel network or passive mixers to generate the chemical gradient. Moreover, since the linear gradient is determined by the liquid reagents input pressure, its generation can be fully achieved in faster intervals than one second, being a more timely-efficient gradient generation process compared to other source-sink passive diffusion devices. The resulting linear gradient generator device was therefore adapted to perform for the first time, a volumetric titration on a chip where the amount of reagents used is fixed to the total volume of the micro channel, avoiding an important waste generation like in other flow-based titration techniques. The associated analytical method is automated and its linearity has been proven for the free acidity determination of U(VI) samples containing up to 0.5M of actinide ion and nitric acid in a concentration range of 0.5M to 3M. In addition to automation, the developed analytical methodology and technique greatly improves the standard off-line oxalate complexation and alkalimetric titration method by reducing a thousand fold the required sample volume, forty times the nuclear waste per analysis as well as the analysis time by eight-fold. The developed device represents, therefore, a great step towards an easy-to-handle nuclear-related application, which in the short term could be used to improve laboratory safety as much as to reduce the environmental impact of the radioanalytical chain.

Keywords: free acidity, lab-on-a-chip, linear concentration gradient, Taylor-Aris dispersion, volumetric titration

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Authors: Belly Yordan

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Orthodontic treatment can be done by using the fix and removable orthodontic appliance. The success of treatment depends on the patient’s age, the type of malocclusion, treatment of space discrepancy, patient’s oral hygiene, operator skills, and patient cooperation. This case report was aimed to show the success of orthodontic treatment in patients with skeletal class I relationship, class I angle dental malocclusion with anterior crowding and rotation by using a removable appliance with modification. The removable appliance used is standard with removable plate components such as passive clasp (Adam’s hook clasp) accompanied with some active clasps (labial bow, some springs, etc.). A button is used as an additional tool or combined with other tools to correct tooth in rotated position. The results obtained by the success of treatments which is shown in pre and post-treatment photos, the overjet was reduced, the arch form became normal, the tooth malposition became normal, and rotation was corrected. Facial profile appearance of the patient is getting better, and the dental coordination also became better. This case report is to prove that treatment with the removable appliance is quite successful with the robust wearing of appropriate retainers.

Keywords: success rate, anterior crowding, orthodontic treatment, removable appliances

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Authors: Gopal Ji, Priyanka Dwivedi, Shanthi Sundaram, Rajiv Prakash

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Inhibition effect of aqueous Argemone Mexicana root extract (AMRE) on mild steel corrosion in 1 M HCl has been studied by weight loss, Tafel polarization curves, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. Results indicate that inhibition ability of AMRE increases with the increasing amount of the extract. A maximum corrosion inhibition of 94% is acknowledged at the extract concentration of 400 mg L-1. Polarization curves and impedance spectra reveal that both cathodic and anodic reactions are suppressed due to passive layer formation at metal-acid interface. It is also confirmed by SEM micro graphs and FTIR studies. Furthermore, the effects of acid concentration (1-5 M), immersion time (120 hours) and temperature (30-60˚C) on inhibition potential of AMRE have been investigated by weight loss method and electrochemical techniques. Adsorption mechanism is also proposed on the basis of weight loss results, which shows good agreement with Langmuir isotherm.

Keywords: mild steel, polarization, SEM, acid corrosion, EIS, green inhibition

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Authors: Josiane R. Pires, Marco A. S. González, Bruna L. Brenner, Luciana S. Roos

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The concern with sustainability brought the need for optimization of the buildings to reduce consumption of natural resources. Almost 1/3 of energy demanded by Brazilian housings is used to provide thermal solutions. AEC sector may contribute applying bioclimatic strategies on building design. The aim of this research is to investigate the viability of applying some alternative solutions in residential buildings. The research was developed with computational simulation on single family social housing, examining envelope type, absorptance, and insolation. The analysis of the thermal performance applied both Brazilian standard NBR 15575 and degree-hour method, in the scenery of Porto Alegre, a southern Brazilian city. We used BIM modeling through Revit/Autodesk and used Energy Plus to thermal simulation. The payback of the investment was calculated comparing energy savings and building costs, in a period of 50 years. The results shown that with the increment of envelope’s insulation there is thermal comfort improvement and energy economy, with a pay-back period of 24 to 36 years, in some cases.

Keywords: civil construction, design, thermal performance, energy, economic analysis

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Authors: Fulya Ozbey, Ecehan Ozmehmet

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Health and living in a healthy environment are important for all the living creatures. Healthy buildings are the part of the healthy environment and the ones that people and sometimes the animals spend most of their times in it. Therefore, healthy buildings are important subject for everybody. There are many elements of the healthy buildings from material choice to the thermal comfort including indoor air quality. The aim of this study is, to simulate two natural ventilation strategies which are used as a cooling method in Mediterranean climate, by applying to a residential building and compare the results for Asian climate. Fulltime natural and night-time ventilation strategies are simulated for three days during the summertime in Mediterranean climate. The results show that one of the chosen passive cooling strategies worked on both climates good enough without using additional shading element and cooling device, however, the other ventilation strategy did not provide comfortable indoor temperature enough. Finally, both of the ventilation strategies worked better on the Asian climate than the Mediterranean in terms of the total overheating hours during the chosen period of year.

Keywords: Asian climate, indoor air quality, Mediterranean climate, natural ventilation simulation, thermal comfort

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Authors: Ian Walmsley

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The aim of this paper is to explore the influence of time and temporality on the experience of coming off heroin in prison. The presentation draws on qualitative data collected during a small-scale pilot study of the role of self-care in the process of coming off drugs in prison. Time and temporality emerged as a key theme in the interview transcripts. Drug dependent prisoners experience of time in prison has not been recognized in the research literature. Instead, the literature on prison time typically views prisoners as a homogenous group or tends to focus on the influence of aging and gender on prison time. Furthermore, there is a tendency in the literature on prison drug treatment and recovery to conceptualize drug dependent prisoners as passive recipients of prison healthcare, rather than active agents. In building on these gaps, this paper argues that drug dependent prisoners experience multiple temporalities which involve an interaction between the body-times of the drug dependent prisoner and the economy of time in prison. One consequence of this interaction is the feeling that they are doing, at this point in their prison sentence, double prison time. The second part of the argument is that time and temporality were a means through which they governed their withdrawing bodies. In addition, this paper will comment on the challenges of prison research in England.

Keywords: heroin withdrawal, time and temporality, prison, body

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Authors: Arash Osmani, Ian Robertson, Ihab Habib, Ahmad Aslami

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Foot and Mouth Disease (FMD) is endemic in Afghanistan. A retrospective study of data collected through passive surveillance of outbreaks of FMD from 1995 to 2016 was undertaken. A total of 1471 outbreaks were reported between 1995 and 2008. Of 7776 samples originating from 34 provinces tested between 2009 and 2016 4845 (62.3%) tested positive. The prevalence varied significantly between years (2009 and 2016) (P < 0.001); however, the number of outbreaks did not differ significantly (P = 0.24) between 1995 and 2008. During this period, there was a strong correlation between the number of outbreaks reported and the number of districts with infected animals (r = 0.74, P = 0.002). Serotype O was the predominant serotype detected, although serotypes A and Asia1 were also detected. Cattle were involved in all outbreaks reported. Herat province in the north-west (bordering Iran), Nangarhar province in the east (bordering Pakistan) and Kabul province in the centre of the country had infections detected in all years of the study. The findings from this study provide valuable direction for further research to understand the epidemiology of FMD in Afghanistan.

Keywords: foot and mouth disease, retrospective, epidemiology, Afghanistan

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Authors: Farideh Azimi, Sam Vahedi Tafreshi

Abstract:

This research tries to study the residential buildings in Ahvaz, the common materials used, and the impact of passive methods of energy storage (as one of the most effective ways to reduce energy consumption in residential complexes) in order to achieve patterns for construction of residential buildings in Ahvaz conditions to reduce energy consumption. In this research, after studying Ahvaz conditions, the components of an existing building were simulated in Energy Plus software, and the climatic data of Ahvaz station was introduced to software. Then to achieve the most optimal conditions of energy consumption in Ahvaz conditions, each of the residential building elements was optimized. The results of simulation showed that using inactive materials and design including double glass, outside wall insulation, inverted roof, etc. in the buildings can reduce energy consumption in the hot and dry climate of Ahvaz. Among the parameters investigated, the inverted roof was the most effective energy saving pattern. According to the results of simulation of the entire building with the most optimal parameters, energy consumption can be saved by a mean of 12.51% in buildings of Ahvaz, and the obtained pattern can also be used in similar climates.

Keywords: residential buildings, thermal comfort, energy storage, Energy Plus software, Ahvaz

Procedia PDF Downloads 359

Authors: Carlos A. Domínguez Torres, Antonio Domínguez Delgado

Abstract:

In this work we study the thermodynamic behavior of some ventilated facades under summer operating conditions in Southern Spain. Under these climatic conditions, indoor comfort implies a high energetic demand due to high temperatures that usually are reached in this season in the considered geographical area. The aim of this work is to determine if during summer operating conditions in Southern Spain, ventilated façades provide some energy saving compared to the non-ventilated façades and to deduce their behavior patterns in terms of energy efficiency. The modeling of the air flow in the channel has been performed by using Navier-Stokes equations for thermodynamic flows. Numerical simulations have been carried out with a 2D Finite Element approach. This way, we analyze the behavior of ventilated façades under different weather conditions as variable wind, variable temperature and different levels of solar irradiation. CFD computations show that the combined effect of the shading of the external wall and the ventilation by the natural convection into the air gap achieve a reduction of the heat load during the summer period. This reduction has been evaluated by comparing the thermodynamic performances of two ventilated and two unventilated façades with the same geometry and thermophysical characteristics.

Keywords: passive cooling, ventilated façades, energy-efficient building, CFD, FEM

Procedia PDF Downloads 355

Authors: M. Deyab, A. Al-Sabagh, S. Keera

Abstract:

The effects of flow velocity, sand concentration, sand size and temperature on erosion-corrosion of carbon steel in oil sands slurry were studied by electrochemical polarization measurements. It was found that the anodic excursion spans of carbon steel in oil sands slurry are characterized by the occurrence of a well-defined anodic peak, followed by a passive region. The data reveal that increasing flow velocity, sand concentration and temperature enhances the anodic peak current density (jAP) and shifts pitting potential (Epit) towards more negative values. The variation of sand particle size does not have apparent effect on polarization behavior of carbon steel. The ratios of the erosion rate to corrosion rate (E/C) were calculated and discussed. The ratio of erosion to corrosion rates E/C increased with increasing the flow velocity, sand concentration, sand size and temperature indicating that an increasing slurry flow velocity, sand concentration, sand size and temperature resulted in an enhancement of the erosion effect.

Keywords: erosion-corrosion, steel, oil sands slurry, polarization

Procedia PDF Downloads 294

Authors: Dagnija Blumberga, Toms Prodanuks, Ivars Veidenbergs, Andra Blumberga

Abstract:

Gas condensing units with inner tubes heat exchangers represent third generation technology and differ from second generation heat and mass transfer units, which are fulfilled by passive filling material layer. The first one improves heat and mass transfer by increasing cooled contact surface of gas and condensate drops and film formed in inner tubes heat exchanger. This paper presents a selection of significant factors which influence the heat and mass transfer. Experimental planning is based on the research and analysis of main three independent variables; velocity of water and gas as well as density of spraying. Empirical mathematical models show that the coefficient of heat transfer is used as dependent parameter which depends on two independent variables; water and gas velocity. Empirical model is proved by the use of experimental data of two independent gas condensing units in Lithuania and Russia. Experimental data are processed by the use of heat transfer criteria-Kirpichov number. Results allow drawing the graphical nomogram for the calculation of heat and mass transfer conditions in the innovative and energy efficient gas cooling unit.

Keywords: gas condensing unit, filling, inner heat exchanger, package, spraying, tunes

Procedia PDF Downloads 288

Authors: M. A. Deyab, A. Al-Sabagh, S. Keera

Abstract:

The effects of flow velocity, sand concentration, sand size and temperature on erosion-corrosion of petroleum pipelines (carbon steel) in the oil sands slurry were studied by electrochemical polarization measurements. It was found that the anodic excursion spans of carbon steel in the oil sands slurry are characterized by the occurrence of a well-defined anodic peak, followed by a passive region. The data reveal that increasing flow velocity, sand concentration and temperature enhances the anodic peak current density (jAP) and shifts pitting potential (Epit) towards more negative values. The variation of sand particle size does not have apparent effect on polarization behavior of carbon steel. The ratios of the erosion rate to corrosion rate (E/C) were calculated and discussed. The ratio of erosion to corrosion rates E/C increased with increasing the flow velocity, sand concentration, sand size, and temperature indicating that an increasing slurry flow velocity, sand concentration, sand size and temperature resulted in an enhancement of the erosion effect.

Keywords: erosion-corrosion, oil sands slurry, polarization, steel

Procedia PDF Downloads 318