Search results for: fiber volume

Authors: Nora Arbaoui, Rachid Tadili, Ilham Ihoume

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The improvement of the agricultural production and food preservation processes requires the introduction of heating and cooling techniques in greenhouses. To develop these techniques, our work proposes a design of an integrated and autonomous solar system for heating, cooling, and production conservation in greenhouses. The hot air produced by the greenhouse effect during the day will be evacuated to compartments annexed in the greenhouse to dry the surplus agricultural production that is not sold on the market. In this paper, we will give a description of this solar system and the calculation of the fluid’s volume used for heat storage that will be released during the night.

Keywords: solar system, agricultural greenhouse, heating, cooling, storage, drying

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Authors: C. Andreu Sabater, D. Drago, C. Key-aberg, W. Moukrim, B. Naccache

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Present study concerns the optimization of a new vertical axis wind turbine system associated to a dynamoelectric motor. The system is composed by three Savonius wind turbines, arranged in an equilateral triangle. The idea is to propose a new concept of wind turbines through a technical approach allowing find a specific power never obtained before and therefore, a significant reduction of installation costs. In this work different wind flows across the system have been simulated, as well as precise definition of parameters and relations established between them. It will allow define the optimal rotor specific power for a given volume. Calculations have been developed with classical Savonius dimensions.

Keywords: VAWT, savonius, specific power, optimization, weibull

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Authors: Zhanna Yermekova, Sergey Roslyakov

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Solution combustion synthesis (SCS) is the unique method which multiple times has proved itself as an effective and efficient approach for the versatile synthesis of a variety of materials. It has significant advantages such as relatively simple handling process, high rates of product synthesis, mixing of the precursors on a molecular level, and fabrication of the nanoproducts as a result. Nowadays, an overwhelming majority of solution combustion investigations performed through the volume combustion synthesis (VCS) where the entire liquid precursor is heated until the combustion self-initiates throughout the volume. Less amount of the experiments devoted to the steady-state self-propagating mode of SCS. Under the beforementioned regime, the precursor solution is dried until the gel-like media, and later on, the gel substance is locally ignited. In such a case, a combustion wave propagates in a self-sustaining mode as in conventional solid combustion synthesis. Even less attention is given to the impregnated active layer (IAL) mode of solution combustion. An IAL approach to the synthesis is implying that the solution combustion of the precursors should be initiated on the surface of the third chemical or inside the third substance. This work is aiming to emphasize an underestimated role of the impregnated active layer mode of the solution combustion synthesis for the fundamental studies of the combustion mechanisms. It also serves the purpose of popularizing the technical terms and clarifying the difference between them. In order to do so, the solution combustion synthesis of γ-FeNi (PDF#47-1417) alloy has been accomplished within short (seconds) one-step reaction of metal precursors with hexamethylenetetramine (HTMA) fuel. An idea of the special role of the Ni in a process of alloy formation was suggested and confirmed with the particularly organized set of experiments. The first set of experiments were conducted in a conventional steady-state self-propagating mode of SCS. An alloy was synthesized as a single monophasic product. In two other experiments, the synthesis was divided into two independent processes which are possible under the IAL mode of solution combustion. The sequence of the process was changed according to the equations which are describing an Experiment A and B below: Experiment A: Step 1. Fe(NO₃)₃*9H₂O + HMTA = FeO + gas products; Step 2. FeO + Ni(NO₃)₂*6H₂O + HMTA = Ni + FeO + gas products; Experiment B: Step 1. Ni(NO₃)₂*6H₂O + HMTA = Ni + gas products; Step 2. Ni + Fe(NO₃)₃*9H₂O + HMTA = Fe₃Ni₂+ traces (Ni + FeO). Based on the IAL experiment results, one can see that combustion of the Fe(NO₃)₃9H₂O on the surface of the Ni is leading to the alloy formation while presence of the already formed FeO does not affect the Ni(NO₃)₂*6H₂O + HMTA reaction in any way and Ni is the main product of the synthesis.

Keywords: alloy, hexamethylenetetramine, impregnated active layer mode, mechanism, solution combustion synthesis

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Authors: Suzanne Giasson, Alberto Guerron

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Stimuli-responsive polymer coatings can be used as functional elements in nanotechnologies, such as valves in microfluidic devices, as membranes in biomedical engineering, as substrates for the culture of biological tissues or in developing nanomaterials for targeted therapies in different diseases. However, such coatings usually suffer from major shortcomings, such as a lack of selectivity and poor environmental stability. The study will present multi-responsive hierarchical and hybrid polymer-based coatings aiming to overcome some of these limitations. Hierarchical polymer coatings, consisting of two-dimensional arrays of thermo-responsive cationic PNIPAM-based microgels and surface-functionalized with non-responsive or pH-responsive polymers, were covalently grafted to substrates to tune the surface chemistry and the elasticity of the surface independently using different stimuli. The characteristic dimensions (i.e., layer thickness) and surface properties (i.e., adhesion, friction) of the microgel coatings were assessed using the Surface Forces Apparatus. The ability to independently control the swelling and surface properties using temperature and pH as triggers were investigated for microgels in aqueous suspension and microgels immobilized on substrates. Polymer chain grafting did not impede the ability of cationic PNIPAM microgels to undergo a volume phase transition above the VPTT, either in suspension or immobilized on a substrate. Due to the presence of amino groups throughout the entirety of the microgel polymer network, the swelling behavior was also pH dependent. However, the thermo-responsive swelling was more significant than the pH-triggered one. The microgels functionalized with PEG exhibited the most promising behavior. Indeed, the thermo-triggered swelling of microgel-co-PEG did not give rise to changes in the microgel surface properties (i.e., surface potential and adhesion) within a wide range of pH values. It was possible for the immobilized microgel-co-PEG to undergo a volume transition (swelling/shrinking) with no change in adhesion, suggesting that the surface of the thermal-responsive microgels remains rather hydrophilic above the VPTT. This work confirms the possibility of tuning the swelling behavior of microgels without changing the adhesive properties. Responsive surfaces whose swelling properties can be reversibly and externally altered over space and time regardless of the surface chemistry are very innovative and will enable revolutionary advances in technologies, particularly in biomedical surface engineering and microfluidics, where advanced assembly of functional components is increasingly required.

Keywords: responsive materials, polymers, surfaces, cell culture

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Authors: Khashayar Kazemzadeh, Mohammad Hanif Dasoomi

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According to the increasing travel demand in cities, bridges and tunnels are viewed as one of the fundamental components of cities transportation systems. Normally, due to geometric constraints forms in the tunnels, the considered speed in the tunnels is lower than the speed in connected highways. Therefore, drivers tend to reduce the speed near the entrance of the tunnels. In this paper, the effect of speed reduction on accident happened in the entrance of the tunnels has been discussed. The relation between accidents frequency and the parameters of speed, traffic volume and time of the accident in the mentioned tunnel has been analyzed and the mathematical model has been proposed.

Keywords: urban highway, accident, tunnel, mathematical model

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Authors: S. Louhibi-Fasla, H. Achour, B. Amrani

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The purpose of this work is to provide some additional information to the existing data on the physical properties of AlBi with state-of-the-art first-principles method of the full potential linear augmented plane wave (FPLAPW). Additionally to the structural properties, the electronic properties have also been investigated. The dependence of the volume, the bulk modulus, the variation of the thermal expansion α, as well as the Debye temperature are successfully obtained in the whole range from 0 to 30 GPa and temperature range from 0 to 1200 K. The latter are the basis of solid-state science and industrial applications and their study is of importance to extend our knowledge on their specific behaviour when undergoing severe constraints of high pressure and high temperature environments.

Keywords: AlBi, FP-LAPW, structural properties, electronic properties

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Authors: S. Movafagh, Y. Bakhshan

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In this study, effect of adding Al2O3 nanoparticle to base fluid (water) in car radiator is investigated numerically. Radiators are compact heat exchangers optimized and evaluated by considering different working conditions. The cooling system of a car plays an important role in vehicle's performance, consists of two main parts, known as radiator and fan. Improving thermal efficiency of engine leads to increase the engine's performance, decline the fuel consumption and decrease the pollution emissions. In this study, the effects of fluid inlet flow rate and nanoparticle volume fraction on heat transfer and pressure drop of acar radiator are studied.

Keywords: forced convection, nanofluid, radiator, CFD simulation

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Authors: Hansraj Riteesh Bookun, Cassandra Monique Hidajat

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This pilot study investigated the efficacy of a newly designed shoe which will act as an intermittent pneumatic compression device to augment venous flow in the lower limb. The aim was to assess the degree with which a wearable intermittent compression device can increase the venous flow in the popliteal vein. Background: Deep venous thrombosis and chronic venous insufficiency are relatively common problems with significant morbidity and mortality. While mechanical and chemical thromboprophylaxis measures are in place in hospital environments (in the form of TED stockings, intermittent pneumatic compression devices, analgesia, antiplatelet and anticoagulant agents), there are limited options in a community setting. Additionally, many individuals are poorly tolerant of graduated compression stockings due to the difficulty in putting them on, their constant tightness and increased associated discomfort in warm weather. These factors may hinder the management of their chronic venous insufficiency. Method: The device is lightweight, easy to wear and comfortable, with a self-contained power source. It features a Bluetooth transmitter and can be controlled with a smartphone. It is externally almost indistinguishable from a normal shoe. During activation, two bladders are inflated -one overlying the metatarsal heads and the second at the pedal arch. The resulting cyclical increase in pressure squeezes blood into the deep venous system. This will decrease periods of stasis and potentially reduce the risk of deep venous thrombosis. The shoe was fitted to 2 healthy participants and the peak systolic velocity of flow in the popliteal vein was measured during and prior to intermittent compression phases. Assessments of total flow volume were also performed. All haemodynamic assessments were performed with ultrasound by a licensed sonographer. Results: Mean peak systolic velocity of 3.5 cm/s with standard deviation of 1.3 cm/s were obtained. There was a three fold increase in mean peak systolic velocity and five fold increase in total flow volume. Conclusion: The device augments venous flow in the leg significantly. This may contribute to lowered thromboembolic risk during periods of prolonged travel or immobility. This device may also serve as an adjunct in the treatment of chronic venous insufficiency. The study will be replicated on a larger scale in a multi—centre trial.

Keywords: venous, intermittent compression, shoe, wearable device

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Authors: Subramanyam Devarakonda Hanumantharao, Udayendu Prakash Sharma, Mahesh Garg

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Introduction: Gomabai Netralaya a reputed eye hospital is located in Neemuch a small city of Madhya Pradesh, India. The hospital is established in 1992 by Late. G.D Agrawal a renowned educationist, freedom fighter and philanthropist. The eye hospital was established to serve all sections of the society in affordable manner. To provide comprehensive eye care services to the rural poor the hospital started organizing outreach camps since 1994. Purpose: To study the cost effectiveness of outreach eye camps for addressing the sustainability issues of the outreach program. Methods: One year statistics of outreach eye camps were collected from Hospital Management Information System software to analyze the productivity of camps. Income and expenses report was collected from outreach department records to analyze per camp expenses and per patient expenses against the income generated. All current year records were analyzed to have accuracy of information and results. Information was collected in two ways: 1)Actual camp performance records and expenses from book of accounts. 2)Cross verification was done through one to one discussion with outreach staff. Results: Total 17534 outpatients were examined through 52 outreach eye camps. Total 6042 (34% of total outpatients) patients were advised with cataracts and 4651 (77% of advice) operations were performed. The average OPD per camp was 337 and per camp 116 patients was advised for cataract surgery and 89 surgeries were performed per camp. Total 18200 US$ incurred on organizing 52 outreach camps in the radius of 100 k.ms. Considering the total outpatients screened through camps the screening cost per patient was 1.00 US$ and considering the surgical output the per surgery expenses was 4.00 US$. The cost recovery of the total expenses was through Government grant of US$ 16.00 per surgery (that includes surgical grant). All logistics cost of camps and patients transportation cost was taken care by local donors. Conclusion: The present study demonstrates that with people’s participation, successful high volume outreach eye camps can be organized. The cost effectiveness of the outreach camps is totally depended on volume of outpatient’s turn-up at camp site and per camp surgical output. The only solution to sustainability of outreach eye camps is sharing of cost with local donors and increasing productivity.

Keywords: camps, outreach, productivity, sustainable

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Authors: Sadhana Deshmukh

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Objective: Men represent only a fraction of the medical aesthetic practice. They are increasingly becoming more cosmetically-inclined. The primary objective is to harmonize facial proportion by prioritizing and focusing on forehead nose, cheek and chin complex. Introduction: Despite tremendous variability, diverse population of the Indian subcontinent, the male skull is unique in its overall larger size, and shape. Men tend to have a large forehead with prominent supraorbital ridges, wide glabella, square orbit, and a prominent protruding mandible. Men have increased skeletal muscle mass, with less facial subcutaneous fat. Facial aesthetics is evolving rapidly. Commonly published canons of facial proportions usually represent feminine standards and are not applicable to males. Strict adherence to these norms is therefore not necessary to obtain satisfying results in male patients. Materials and Methods: Male patients age group 30-60 years have been enrolled. Botulinum toxin and hyaluronic acid fillers were used to update consensus recommendations for facial rejuvenation using these two types of products alone and in combination. Results: There are specific recommendations by facial area, focusing on relaxing musculature, restoring volume, recontouring using toxin and dermal fillers alone and in combination. For upper face, though botulinum toxin remains the cornerstone of treatment, temples and forehead fillers are recommended for optimal results. In Mid face, these fillers are placed more laterally to maintain the masculine look. Botulinum toxin and fillers in combination can improve outcomes in the lower face. Chin augmentation remains the center point for lower face. Conclusions: Males are more likely to have shorter doctor visits, less likely to ask questions, have a lower attention to bodily changes. The physician must patiently gauge male patients’ aging and cosmetic goals. Clinicians can also benefit from ongoing guidance on products, tailoring treatments, treating multiple facial areas, and using combinations of products. An appreciation that rejuvenation is 3-dimensional process involving muscle control, volume restoration and recontouring helps.

Keywords: male aesthetics, botulinum toxin, hyaluronic acid dermal fillers, Asian patients

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Authors: K. P. Mredula, D. C. Vakaskar

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The article traces developments and evolution of various algorithms developed for solving partial differential equations using the significant combination of wavelet with few already explored solution procedures. The approach depicts a study over a decade of traces and remarks on the modifications in implementing multi-resolution of wavelet, finite difference approach, finite element method and finite volume in dealing with a variety of partial differential equations in the areas like plasma physics, astrophysics, shallow water models, modified Burger equations used in optical fibers, biology, fluid dynamics, chemical kinetics etc.

Keywords: multi-resolution, Haar Wavelet, partial differential equation, numerical methods

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Authors: Gordana Branković, Dejan Dodig, Vesna Pajić, Vesna Kandić, Desimir Knežević, Nenad Đurić

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The wheat grain quality properties are influenced by genotype, environmental conditions and genotype × environment interaction (GEI). The increasing request of more nutritious wheat products will direct future breeding programmes. Therefore, the aim of investigation was to determine: i) variability of the protein content (PC), wet gluten content (WG) and Zeleny sedimentation volume (ZS); ii) components of variance, heritability in a broad sense (hb2), and expected genetic advance as percent of mean (GAM) for PC, WG, and ZS; iii) correlations between PC, WG, ZS, and most important agronomic traits; in order to assess expected breeding success versus environmental impact for these quality traits. The plant material consisted of 30 genotypes of bread wheat (Triticum aestivum L. ssp. aestivum) and durum wheat (Triticum durum Desf.). The trials were sown at the three test locations in Serbia: Rimski Šančevi, Zemun Polje and Padinska Skela during 2010-2011 and 2011-2012. The experiments were set as randomized complete block design with four replications. The plot consisted of five rows of 1 m2 (5 × 0.2 m × 1 m). PC, WG and ZS were determined by the use of Near infrared spectrometry (NIRS) with the Infraneo analyser (Chopin Technologies, France). PC, WG and ZS, in bread wheat, were in the range 13.4-16.4%, 22.8-30.3%, and 39.4-67.1 mL, respectively, and in durum wheat, in the range 15.3-18.1%, 28.9-36.3%, 37.4-48.3 mL, respectively. The dominant component of variance for PC, WG, and ZS, in bread wheat, was genotype with the genetic variance/GEI variance (VG/VG × E) relation of 3.2, 2.9 and 1.0, respectively, and in durum wheat was GEI with the VG/VG × E relation of 0.70, 0.69 and 0.49, respectively. hb2 and GAM values for PC, WG and ZS, in bread wheat, were 94.9% and 12.6%, 93.7% and 18.4%, and 86.2% and 28.1%, respectively, and in durum wheat, 80.7% and 7.6%, 79.7% and 10.2%, and 74% and 11.2%, respectively. The most consistent through six environments, statistically significant correlations, for bread wheat, were between PC and spike length (-0.312 to -0.637); PC, WG, ZS and grain number per spike (-0.320 to -0.620; -0.369 to -0.567; -0.301 to -0.378, respectively); PC and grain thickness (0.338 to 0.566), and for durum wheat, were between PC, WG, ZS and yield (-0.290 to -0.690; -0.433 to -0.753; -0.297 to -0.660, respectively); PC and plant height (-0.314 to -0.521); PC, WG and spike length (-0.298 to -0.597; -0.293 to -0.627, respectively); PC, WG and grain thickness (0.260 to 0.575; 0.269 to 0.498, respectively); PC, WG and grain vitreousness (0.278 to 0.665; 0.357 to 0.690, respectively). Breeding success can be anticipated for ZS in bread wheat due to coupled high values for hb2 and GAM, suggesting existence of additive genetic effects, and also for WG in bread wheat, due to very high hb2 and medium high GAM. The small, and medium, negative correlations between PC, WG, ZS, and yield or yield components, indicate difficulties to select simultaneously for high quality and yield, depending on linkage for particular genetic arrangements to be broken by recombination.

Keywords: bread and durum wheat, genetic advance, protein and wet gluten content, Zeleny sedimentation volume

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Authors: Soner Guler, Fuat Korkut

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Recently, the using of lightweights concretes in construction sector is rapidly increasing all over the world. Faster construction, low density and thermal transmitting coefficient and high fire resistance are the remarkable characteristics of the lightweight concretes. Lightweight concrete can be described as a type of concrete which enhance the volume of the mixture while giving additional advantages such as to reduce the dead weight of the structures. It is lighter than the conventional concrete. The use of lightweight concrete has been widely spread across countries such as USA, United Kingdom, and Sweden. In this study, the necessity of the using of lightweights concretes in the construction sector is emphasized and evaluated briefly for the architectures and civil engineers.

Keywords: lightweights concretes, low density, low thermal coefficient, construction sector

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Authors: Brahim Fersadou, Henda Kahalerras

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This work deals with the problem of MHD mixed convection in a completely porous and differentially heated vertical channel. The model of Darcy-Brinkman-Forchheimer with the Boussinesq approximation is adopted and the governing equations are solved by the finite volume method. The effects of magnetic field and buoyancy force intensities are given by the Hartmann and Richardson numbers respectively, as well as the Joule heating represented by Eckert number on the velocity and temperature fields, are examined. The main results show an augmentation of heat transfer rate with the decrease of Darcy number and the increase of Ri and Ha when Joule heating is neglected.

Keywords: heat sources, magnetic field, mixed convection, porous channel

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Authors: Donghee Kang

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Background: Cancer pain is very difficult to control as the mechanism of pain is varied, and the patient has several co-morbidities. The use of Intravenous Patient-Controlled Analgesia (IV-PCA) can effectively control underlying pain and breakthrough pain. Ketamine is used in many pain patients due to its unique analgesic effect. In this study, it was checked whether there was a difference in the amount of analgesic usage, pain control degree, and side effects between patients who controlled pain with fentanyl-based IV-PCA and those who added Ketamine for pain control. Methods: Among the patients referred to this department for cancer pain, IV-PCA was applied to patients who were taking sufficient oral analgesics but could not control them or had blood clotting disorders that made the procedure difficult, and this patient group was targeted. In IV-PCA, 3000 mcg of Fentanyl, 160 mg of Nefopam, and 0.3 mg of Ramosetrone were mixed with normal saline to make a total volume of 100 ml. Group F used this IV-PCA as it is, and group K mixed 250 mg of Ketamine with normal saline to make a total volume of 100 ml. For IV-PCA, the basal rate was 0.5ml/h, the bolus was set to 1ml when pressed once, and the lockout time was set to 15 minutes. If pain was not controlled after IV-PCA application, 500 mcg of Fentanyl was added, and if excessive sedation or breathing difficulties occurred, the use was stopped for one hour. After that, the degree of daily pain control, analgesic usage, and side effects were investigated for seven days using this IV-PCA. Results: There was no difference between the two groups in the demographic data. Both groups had adequate pain control. Initial morphine milligram equivalents did not differ between the two groups, but the total amount of Fentanyl used for seven days was significantly different between the two groups [p=0.014], and group F used more Fentanyl through IV-PCA. In addition, the amount of sleeping pills used during the seven days was higher in Group F [p<0.01]. Overall, there was no difference in the frequency of side effects between the two groups, but the nausea was more frequent in Group F [p=0.031]. Discussion: When the two groups were compared, pain control was good in both groups. This seems to be because Fentanyl-based IV-PCA showed an adequate pain control effect. However, there was a significant difference in the total amount of opioid (Fentanyl) used, which is thought to be the opioid-sparing effect of Ketamine. Also, among the side effects, nausea was significantly less, which is thought to be possible because the amount of opioids used in the Ketamine group was small. The frequency of requesting sleeping pills was significantly less in the group using Ketamine, and it seems that Ketamine also helped improve sleep quality. In conclusion, using Ketamine with an opioid to control pain seems to have advantages. IV-PCA, which can be used effectively when other procedures are difficult, is more effective and safer when used together with Ketamine than opioids alone.

Keywords: cancer pain, intravenous patient-controlled analgesia, Ketamine, opioid

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Authors: Ehsan Yari

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In this paper, a numerical study of sheet cavitation has been performed on DTMB4119 and E779A marine propellers with the boundary element method. In propeller design, various parameters of geometry and fluid are incorporated. So a program is needed to solve the flow taking the whole parameters changing into account. The capability of analyzing the wetted and cavitation flow around propellers in steady, unsteady, uniform, and non-uniform conditions while decreasing computational time compared to numerical finite volume methods with acceptable precision are the characteristic features of the present method. Moreover, modifying the position of the detachment point and its corresponding potential value has been considered. Numerical results have been validated with experimental data, showing a good conformation.

Keywords: cavitation, BEM, DTMB4119, E779A

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Authors: Prodromos E. Atlamazoglou

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The method of moments combined with the method of symmetrical components is used for the analysis of interstitial hyperthermia applicators. The basis and testing functions are both piecewise sinusoids, qualifying our technique as a Galerkin one. The dielectric coatings are modeled by equivalent volume polarization currents, which are simply related to the conduction current distribution, avoiding in that way the introduction of additional unknowns or numerical integrations. The results of our method for a four dipole circular array, are in agreement with those already published in literature for a same hyperthermia configuration. Apart from being accurate, our approach is more general, more computationally efficient and takes into account the coupling between the antennas.

Keywords: hyperthermia, integral equations, insulated antennas, method of symmetrical components

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Authors: Boukhris Lahouari

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Simulation of solar dryers with ANSYS has revolutionized the way in which drying processes are optimized and analyzed in various industries. This advanced software allows engineers and researchers to simulate the behavior of a solar dryer under different conditions, helping to improve efficiency and reduce energy consumption. This work presents a numerical study of a direct solar dryer, which uses radiation and natural convection to dry agricultural products. The simulations were made in order to determine the dynamic and thermal fields under the influence of the variation in the size of the inlet and outlet opening. The conservation equations based on the standard k-ε turbulence model are solved by the finite volume method using the ANSYS-Fluent commercial code.

Keywords: solar dryer, CFD, solar radiation, natural convection, turbulent flow

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Authors: Zeena Dcosta, Junaid Ahmed, Ceena Denny, Nandita Shenoy

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In the field of dentistry, there are many conditions which warrant the requirement of three-dimensional imaging that can aid in diagnosis and therapeutic management. Cone beam computed tomography (CBCT) is considered highly accurate in producing a three-dimensional image of an object and provides a complete insight of various findings in the captured volume. But, most of the clinicians focus primarily on the teeth and jaws and numerous unanticipated clinically significant incidental findings may be missed out. Rapid integration of CBCT into the practice of dentistry has led to the detection of various incidental findings. However, the prevalence of these incidental findings is still unknown. Thus, the study aimed to discern the reason for referral and to identify incidental findings on the referred CBCT scans. Patient’s demographic data such as age and gender was noted. CBCT scans of multiple fields of views (FOV) were considered. The referral for CBCT scans was broadly classified into two major categories: diagnostic scan and treatment planning scan. Any finding on the CBCT volumes, other than the area of concern was recorded as incidental finding which was noted under airway, developmental, pathological, endodontics, TMJ, bone, soft tissue calcifications and others. Few of the incidental findings noted under airway were deviated nasal septum, nasal turbinate hypertrophy, mucosal thickening and pneumatization of sinus. Developmental incidental findings included dilaceration, impaction, pulp stone and gubernacular canal. Resorption of teeth and periapical pathologies were noted under pathological incidental findings. Root fracture along with over and under obturation was noted under endodontics. Incidental findings under TMJ were flattening, erosion and bifid condyle. Enostosis and exostosis were noted under bone lesions. Tonsillolth, sialolith and calcified styloid ligament were noted under soft tissue calcifications. Incidental findings under others included foreign body, fused C1- C2 vertebrae, nutrient canals, and pneumatocyst. Maxillofacial radiologists should be aware of possible incidental findings and should be vigilant about comprehensively evaluating the entire captured volume, which can help in early diagnosis of any potential pathologies that may go undetected. Interpretation of CBCT is truly an art and with the experience, we can unravel the secrets hidden in the grey shades of the radiographic image.

Keywords: cone beam computed tomography, incidental findings, maxillofacial region, radiologist

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Authors: Dhananjay Singh, M. Abdullah-Al-Wadud

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The Internet of Things is a concept of a large scale ecosystem of wireless actuators. The actuators are defined as things in the IoT, those which contribute or produces some data to the ecosystem. However, ubiquitous data collection, data security, privacy preserving, large volume data processing, and intelligent analytics are some of the key challenges into the IoT technologies. In order to solve the security requirements, challenges and threats in the IoT, we have discussed a message authentication mechanism for IoT applications. Finally, we have discussed data encryption mechanism for messages authentication before propagating into IoT networks.

Keywords: Internet of Things (IoT), message authentication, privacy, security

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Authors: Piotr K. Szewczyk, Arkadiusz Gradys, Sungkyun Kim, Luana Persano, Mateusz M. Marzec, Oleksander Kryshtal, Andrzej Bernasik, Sohini Kar-Narayan, Pawel Sajkiewicz, Urszula Stachewicz

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Piezoelectric polymers have received great attention in smart textiles, wearables, and flexible electronics. Their potential applications range from devices that could operate without traditional power sources, through self-powering sensors, up to implantable biosensors. Semi-crystalline PVDF is often proposed as the main candidate for industrial-scale applications as it exhibits exceptional energy harvesting efficiency compared to other polymers combined with high mechanical strength and thermal stability. Plenty of approaches have been proposed for obtaining PVDF rich in the desired β-phase with electric polling, thermal annealing, and mechanical stretching being the most prevalent. Electrospinning is a highly tunable technique that provides a one-step process of obtaining highly piezoelectric PVDF fibers without the need for post-treatment. In this study, voltage polarity and relative humidity influence on electrospun PVDF, fibers were investigated with the main focus on piezoelectric β-phase contents and piezoelectric performance. Morphology and internal structure of fibers were investigated using scanning (SEM) and transmission electron microscopy techniques (TEM). Fourier Transform Infrared Spectroscopy (FITR), wide-angle X-ray scattering (WAXS) and differential scanning calorimetry (DSC) were used to characterize the phase composition of electrospun PVDF. Additionally, surface chemistry was verified with X-ray photoelectron spectroscopy (XPS). Piezoelectric performance of individual electrospun PVDF fibers was measured using piezoresponse force microscopy (PFM), and the power output from meshes was analyzed via custom-built equipment. To prepare the solution for electrospinning, PVDF pellets were dissolved in dimethylacetamide and acetone solution in a 1:1 ratio to achieve a 24% solution. Fibers were electrospun with a constant voltage of +/-15kV applied to the stainless steel nozzle with the inner diameter of 0.8mm. The flow rate was kept constant at 6mlh⁻¹. The electrospinning of PVDF was performed at T = 25°C and relative humidity of 30 and 60% for PVDF30+/- and PVDF60+/- samples respectively in the environmental chamber. The SEM and TEM analysis of fibers produced at a lower relative humidity of 30% (PVDF30+/-) showed a smooth surface in opposition to fibers obtained at 60% relative humidity (PVDF60+/-), which had wrinkled surface and additionally internal voids. XPS results confirmed lower fluorine content at the surface of PVDF- fibers obtained by electrospinning with negative voltage polarity comparing to the PVDF+ obtained with positive voltage polarity. Changes in surface composition measured with XPS were found to influence the piezoelectric performance of obtained fibers what was further confirmed by PFM as well as by custom-built fiber-based piezoelectric generator. For PVDF60+/- samples humidity led to an increase of β-phase contents in PVDF fibers as confirmed by FTIR, WAXS, and DSC measurements, which showed almost two times higher concentrations of β-phase. A combination of negative voltage polarity with high relative humidity led to fibers with the highest β-phase contents and the best piezoelectric performance of all investigated samples. This study outlines the possibility to produce electrospun PVDF fibers with tunable piezoelectric performance in a one-step electrospinning process by controlling relative humidity and voltage polarity conditions. Acknowledgment: This research was conducted within the funding from m the Sonata Bis 5 project granted by National Science Centre, No 2015/18/E/ST5/00230, and supported by the infrastructure at International Centre of Electron Microscopy for Materials Science (IC-EM) at AGH University of Science and Technology. The PFM measurements were supported by an STSM Grant from COST Action CA17107.

Keywords: crystallinity, electrospinning, PVDF, voltage polarity

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Authors: Mohammad Ali Hasanzadeh, Thierry Van Elslander, Eddy Van De Voorde

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About 90 percent of world merchandise trade by volume being carried by sea. Maritime transport remains as back bone behind the international trade and globalization meanwhile all seaborne goods need using at least two ports as origin and destination. Amid seaborne traded cargos, container traffic is a prosperous market with about 16% in terms of volume. Albeit containerized cargos are less in terms of tonnage but, containers carry the highest value cargos amongst all. That is why efficient handling of containers in ports is very important. Accidents are the foremost causes that lead to port inefficiency and a surge in total transport cost. Having different port safety management systems (PSMS) in place, statistics on port accidents show that numerous accidents occur in ports. Some of them claim peoples’ life; others damage goods, vessels, port equipment and/or the environment. Several accident investigation illustrate that the most common accidents take place throughout transport operation, it sometimes accounts for 68.6% of all events, therefore providing a safer workplace depends on reducing collision risk. In order to quantify risks at the port area different variables can be used as exposure measurement. One of the main motives for defining and using exposure in studies related to infrastructure is to account for the differences in intensity of use, so as to make comparisons meaningful. In various researches related to handling containers in ports and intermodal terminals, different risk exposures and also the likelihood of each event have been selected. Vehicle collision within the port area (10-7 per kilometer of vehicle distance travelled) and dropping containers from cranes, forklift trucks, or rail mounted gantries (1 x 10-5 per lift) are some examples. According to the objective of the current research, three categories of accidents selected for collision risk assessment; fall of container during ship to shore operation, dropping container during transfer operation and collision between vehicles and objects within terminal area. Later on various consequences, exposure and probability identified for each accident. Hence, reducing collision risks profoundly rely on picking the right risk exposures and probability of selected accidents, to prevent collision accidents in container terminals and in the framework of risk calculations, such risk exposures and probabilities can be useful in assessing the effectiveness of safety programs in ports.

Keywords: container terminal, collision, seaborne trade, risk exposure, risk probability

Procedia PDF Downloads 378

Authors: P. Mendes, H. Stel, R. E. M. Morales

Abstract:

This article presents a numerical and experimental study of turbulent flow in corrugated pipes with helically “d-type" grooves, for Reynolds numbers between 7500 and 100,000. The ANSYS-CFX software is used to solve the RANS equations with the BSL two equation turbulence model, through the element-based finite-volume method approach. Different groove widths and helix angles are considered. Numerical results are validated with experimental pressure drop measurements for the friction factor. A correlation for the friction factor is also proposed considering the geometric parameters and Reynolds numbers evaluated.

Keywords: turbulent flow, corrugated pipe, helical, numerical, experimental, friction factor, correlation

Procedia PDF Downloads 487

Authors: Ridha Zgolli, Ahmed Belhaj, Maroua Ennouri

Abstract:

This study presents a new method to predict cavitation area that may be eroded. It is based on the post-treatment of URANS simulations in cavitant flows. The most RANS calculations with incompressible consideration are based on cavitation model using mixture fluid with density (ρm) calculated as a function of liquid density (ρliq), vapour or gas density (ρvap) and vapour or gas volume fraction α (ρm = αρvap + (1-α) ρliq). The calculations are performed on hydrofoil geometries and compared with experimental works concerning flows characteristics (size of pocket, pressure, velocity). We present here the used cavitation model and the approach followed to evaluate the value of α fixing the shape of pocket around wall before collapsing.

Keywords: flows, CFD, cavitation, erosion

Procedia PDF Downloads 339

Authors: N. Mohseni, S. Janitabar, S.J. Ahmadi, M. Roshanzamir, M. Thaghizadeh

Abstract:

There has been proposed a technique for getting thorium dioxide mesoporous nanocrystalline. In this paper thorium dioxide powder was synthesized through the sol-gel method using hydrated thorium nitrate and ammonium hydroxide as starting materials and Triton X100 as surfactant. ThO2 gel was characterized by thermogravimetric (TG), and prepared ThO2 powder was subjected to scanning electron microscopy (SEM), X-ray diffraction (XRD), and Brunauer-Emett-Teller (BET) analyses studies. Detailed analyses show that prepared powder consisted of phase with the space group Fm3m of thoria and its crystalline size was 27 nm. The thoria possesses 16.7 m2/g surface area and the pore volume and size calculated to be 0.0423 cc/g and 1.947 nm, respectively.

Keywords: mesoporous, nanocrystalline, sol-gel, thoria

Procedia PDF Downloads 284

Authors: K. Manmi, Q. X. Wang

Abstract:

This paper investigates microbubble dynamics subject to ultrasound in a weakly viscous fluid near a rigid boundary. The phenomenon is simulated using a boundary integral method. The weak viscous effects are incorporated into the model through the normal stress balance across the bubble surface. The model agrees well with the Rayleigh-Plesset equation for a spherical bubble for several cycles. The effects of the fluid viscosity in the bubble dynamics are analyzed, including jet development, centroid movement and bubble volume.

Keywords: microbubble dynamics, bubble jetting, viscous effect, boundary integral method

Procedia PDF Downloads 486

Authors: Douhi Reda Bouabdellah, Khalafi Hamid, Belamri Samir

Abstract:

The desire to improve the safety of nuclear reactor containment has revealed the need for data on the thermo mechanical behavior of concrete in case of accident during which the concrete is exposed to high temperatures. The aim of the present work is to study the influence of high temperature on the behavior of ordinary concrete specimens loaded by an effort of compression. A thermal model is developed by discretization volume elements (CASTEM). The results of different simulations, combined with other findings help to bring a physical phenomenon explanation Thermo mechanical concrete structures, which allowed to obtain the variation of the stresses anywhere in point or node and each subsequent temperature different directions X, Y and Z.

Keywords: concrete, thermic-gradient, fire resistant, simulation by CASTEM, mechanical strength

Procedia PDF Downloads 311

Authors: Katarzyna Pawęska, Aleksandra Bawiec, Ewa Burszta-Adamiak, Wiesław Fiałkiewicz

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The water shortage becomes a serious problem not only in African and Middle Eastern countries, but also recently in the European Union. Scarcity of water means that not all agricultural, industrial and municipal needs will be met. When the annual availability of renewable freshwater per capita is less than 1,700 cubic meters, countries begin to experience periodic or regular water shortages. The phenomenon of water stress is the result of an imbalance between the constantly growing demand for water and its availability. The constant development of industry, population growth, and climate changes make the situation even worse. The search for alternative water sources and independent supplies is becoming a priority for many countries. Data enabling the assessment of country’s condition regarding water resources, water consumption, water price, wastewater volume, forecasted climate changes e.g. temperature, precipitation, are scattered and their interpretation by common entrepreneurs may be difficult. For this purpose, a digital tool has been developed to support decisions related to the implementation of water and wastewater re-use systems, as a result of an international research project “Framework for organizational decision-making process in water reuse for smart cities” (SMART-WaterDomain) funded under the EIG-CONCERT Japan call on Smart Water Management for Sustainable Society. The developed geo-visualization tool graphically presents, among others, data about the capacity of wastewater treatment plants and the volume of water demand in the private and public sectors for Poland, Germany, and the Czech Republic. It is expected that such a platform, extended with economical water management data and climate forecasts (temperature, precipitation), will allow in the future independent investigation and assessment of water use rate and wastewater production on the local and regional scale. The tool is a great opportunity for small business owners, entrepreneurs, farmers, local authorities, and common users to analyze the impact of climate change on the availability of water in the regions of their business activities. Acknowledgments: The authors acknowledge the support of the Project Organisational Decision Making in Water Reuse for Smart Cities (SMART- WaterDomain), funded by The National Centre for Research and Development and supported by the EIG-Concert Japan.

Keywords: circular economy, digital tool, geo-visualization, wastewater re-use

Procedia PDF Downloads 58

Authors: M. Younus, Muhammad Shafique, M. Athar Khan, Tanveer Akhtar , M. Moeen Athar

Abstract:

A total of 48 apparently healthy weaned sheep lambs (Ovis aries) of 8-10 weeks old weighing 7-10 Kg were purchased from the contractors, maintained in the experimental station of University of the Punjab, Quaid-e-Azam Campus at Lahore, Pakistan. They were dewormed against nematodes with levamisole (ICI) at recommended dose rates. The feces were tested against the parasitic eggs, no helminths ova were seen. All the 48 sheep lambs were divided into two groups i.e. group A & group B. Group 'A' comprising of 40 sheep, kept as infected groups whereas group 'B' comprising of 08 sheep & kept as a new infected control group. Each sheep lamb of group A was given 3-4 fresh gravid segments contains 2-3 thousand eggs of Echinococcus granulosus. These were collected from experimentally infected dogs by feeding fresh hydrated cysts collected from liver & lungs of sheep after slaughtering. Each lamb was fed with fresh gravid segments for a total period of 5 days or each alternate day. Coagulated blood was collected before the start of infected diet and after every month by jugular phlebotomy of each sheep lamb from the infected & new infected control group. One lamb each from group A & group B was slaughtered at the end of each month for the presence of macroscopic hydatid cyst in viscera & abdominal cavity. After 180 days of the experiment, hydatid cysts were confirmed in the abdominal cavity. Hematological parameters of zero days & then at the end of every month revealed that there was a gradual increase (PL 0.05) in the White Blood Cell (WBC), Mean Corpuscular Volume (MCV), Mean Corpuscular Hemoglobin Concentration (MCHC) and Erythrocyte Sedimentation Rates (ESR). The increasing trend was probably due to inflammatory response and lytic effect of the newly developing E. granulosus hydatid cysts. The red blood cell (RBC), Hemoglobin (HB), Packed Cell Volume (PCV) and Mean Corpuscular Hemoglobin (MCH) infected groups were decreased significantly as compared to the control group (PL 0.05). The experiment was terminated at the end of the 7th month. It can be concluded that Echinococcus granulosus can damage livestock and other intermediate hosts such as horses, the development of hydatid cysts affect the organs due to the growing cysts pressuring the organ tissues. Parts of the tissue die, which impairs the functioning of the affected organ. The clinical signs depend on the affected organ. The major damage for livestock is organ condemnation at slaughter.

Keywords: echinococcus granulosus, hydatidosis, sheep, hematology

Procedia PDF Downloads 420

Authors: A. K. Visnuprasad, P. J. Jojo, Reshma Bhaskaran

Abstract:

Computational fluid dynamics (CFD) is used to simulate the distribution of indoor radon concentration in a living room with elevated levels of radon concentration which varies from 22 Bqm-3 to 1533 Bqm-3 in 24 hours. Finite volume method (FVM) was used for the simulation. The simulation results were experimentally validated at 16 points in two horizontal planes (y=1.4m & y=2.0m) using pin-hole dosimeters and at 3 points using scintillation radon monitor (SRM). Passive measurement using pin-hole dosimeters were performed in all seasons. Another simulation was done to find a suitable position for a passive ventilation system for the effective mitigation of radon.

Keywords: indoor radon, computational fluid dynamics, radon flux, ventilation rate, pin-hole dosimeter

Procedia PDF Downloads 416