Search results for: physics laboratory
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 2773

Search results for: physics laboratory

2413 The Effects of Three Levels of Contextual Inference among adult Athletes

Authors: Abdulaziz Almustafa

Abstract:

Considering the critical role permanence has on predictions related to the contextual interference effect on laboratory and field research, this study sought to determine whether the paradigm of the effect depends on the complexity of the skill during the acquisition and transfer phases. The purpose of the present study was to investigate the effects of contextual interference CI by extending previous laboratory and field research with adult athletes through the acquisition and transfer phases. Male (n=60) athletes age 18-22 years-old, were chosen randomly from Eastern Province Clubs. They were assigned to complete blocked, random, or serial practices. Analysis of variance with repeated measures MANOVA indicated that, the results did not support the notion of CI. There were no significant differences in acquisition phase between blocked, serial and random practice groups. During the transfer phase, there were no major differences between the practice groups. Apparently, due to the task complexity, participants were probably confused and not able to use the advantages of contextual interference. This is another contradictory result to contextual interference effects in acquisition and transfer phases in sport settings. One major factor that can influence the effect of contextual interference is task characteristics as the nature of level of difficulty in sport-related skill.

Keywords: contextual interference, acquisition, transfer, task difficulty

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2412 Chemical Composition and Insecticidal Properties of Moroccan Plant Extracts against Dactylopius Opuntiae (Cockerell) Under Laboratory and Greenhouse Conditions

Authors: Imane Naboulsi, Mansour Sobeh, Rachid Lamzira, Karim El Fakhouri, Widad Ben Bakrim, Chaimae Ramdani, Rachid Boulamtat, Mustapha El Bouhssini, Jane ward, Abdelaziz Yasri, Aziz Aboulmouhajir

Abstract:

The wild cochineal Dactylopius opuntiae (Cockerell) (Hemiptera: Dactylopiidae) is the major insect pest of the prickly pear Opuntia ficus-indica (L.) in Morocco, which has causedenormous socio-economic and environmental losses to this crop in recent years. This study aimed to investigate the insecticidal potential of six aqueous (100% water), and methanolic (20/80 (v/v) MeOH/H2O) extracts obtained from aromatic and medicinal plants growing in arid and semi-arid regions of Morocco to control nymphs and adult females of D. opuntiae, under laboratory and greenhouse conditions. Under laboratory conditions, the aqueous extracts of Atriplex halimus at 5% caused significant mortality in nymphs with 71% four days after application and 88%on adult females of D. opuntiae8 days post-treatment. Under greenhouse conditions, the aqueous extract of A. halimus combined with black soap at 10 g/L showed the highest mortality rate of nymphs with 100%, 4 days after application. The adult females' mortality increased significantly to reach 83.75%,14 days after the second application of A. halimus aqueous extract at 5%. Phytochemical analysis of the water extract of A. halimus revealed a high content of saponins (24.09 ± 0.71 mg SSE/g DW) compared to other plant extracts, which was confirmed by LC-MS characterization that showed the presence of 36 triterpenoid saponin compounds (derived from oleic-12-en-28-oic acid), in addition to phytoecdysones, simple carboxylic acids, and flavonoids. These findings showed that using the aqueous extract of A. halimus as a biological pesticide could be incorporated into the management package to control the wild cochineal as a safe alternative to chemical insecticides.

Keywords: dactylopius opuntiae, opuntia ficus-indica L., plant extracts, toxicity, atriplex halimus, saponins

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2411 New Method for Determining the Distribution of Birefringence and Linear Dichroism in Polymer Materials Based on Polarization-Holographic Grating

Authors: Barbara Kilosanidze, George Kakauridze, Levan Nadareishvili, Yuri Mshvenieradze

Abstract:

A new method for determining the distribution of birefringence and linear dichroism in optical polymer materials is presented. The method is based on the use of polarization-holographic diffraction grating that forms an orthogonal circular basis in the process of diffraction of probing laser beam on the grating. The intensities ratio of the orders of diffraction on this grating enables the value of birefringence and linear dichroism in the sample to be determined. The distribution of birefringence in the sample is determined by scanning with a circularly polarized beam with a wavelength far from the absorption band of the material. If the scanning is carried out by probing beam with the wavelength near to a maximum of the absorption band of the chromophore then the distribution of linear dichroism can be determined. An appropriate theoretical model of this method is presented. A laboratory setup was created for the proposed method. An optical scheme of the laboratory setup is presented. The results of measurement in polymer films with two-dimensional gradient distribution of birefringence and linear dichroism are discussed.

Keywords: birefringence, linear dichroism, graded oriented polymers, optical polymers, optical anisotropy, polarization-holographic grating

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2410 Experimental and Graphical Investigation on Oil Recovery by Buckley-Leveret Theory

Authors: Khwaja Naweed Seddiqi, Zabihullah Mahdi, Shigeo Honma

Abstract:

Recently increasing oil production from petroleum reservoirs is one of the most important issues in the global energy sector. So, in this paper, the recovery of oil by the waterflooding technique from petroleum reservoir are considered. To investigate the aforementioned phenomena, the relative permeability of two immiscible fluids in sand is measured in the laboratory based on the steady-state method. Two sorts of oils, kerosene and heavy oil, and water are pumped simultaneously into a vertical sand column with different pumping ratio. From the change in fractional discharge measured at the outlet, a method for determining the relative permeability is developed focusing on the displacement mechanism in sand. Then, displacement mechanism of two immiscible fluids in the sand is investigated under the Buckley-Leveret frontal displacement theory and laboratory experiment. Two sorts of experiments, one is the displacement of pore water by oil, the other is the displacement of pore oil by water, are carried out. It is revealed that the relative permeability curves display tolerably different shape owing to the properties of oils, and produce different amount of residual oils and irreducible water saturation.

Keywords: petroleum reservoir engineering, relative permeability, two-phase flow, immiscible displacement in porous media, steady-state method, waterflooding

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2409 Evaluation of Liquefaction Potential of Fine Grained Soil: Kerman Case Study

Authors: Reza Ziaie Moayed, Maedeh Akhavan Tavakkoli

Abstract:

This research aims to investigate and evaluate the liquefaction potential in a project in Kerman city based on different methods for fine-grained soils. Examining the previous damages caused by recent earthquakes, it has been observed that fine-grained soils play an essential role in the level of damage caused by soil liquefaction. But, based on previous investigations related to liquefaction, there is limited attention to evaluating the cyclic resistance ratio for fine-grain soils, especially with the SPT method. Although using a standard penetration test (SPT) to find the liquefaction potential of fine-grain soil is not common, it can be a helpful method based on its rapidness, serviceability, and availability. In the present study, the liquefaction potential has been first determined by the soil’s physical properties obtained from laboratory tests. Then, using the SPT test and its available criterion for evaluating the cyclic resistance ratio and safety factor of liquefaction, the correction of effecting fine-grained soils is made, and then the results are compared. The results show that using the SPT test for liquefaction is more accurate than using laboratory tests in most cases due to the contribution of different physical parameters of soil, which leads to an increase in the ultimate N₁(60,cs).

Keywords: liquefaction, cyclic resistance ratio, SPT test, clay soil, cohesion soils

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2408 Aerodynamic Prediction and Performance Analysis for Mars Science Laboratory Entry Vehicle

Authors: Tang Wei, Yang Xiaofeng, Gui Yewei, Du Yanxia

Abstract:

Complex lifting entry was selected for precise landing performance during the Mars Science Laboratory entry. This study aims to develop the three-dimensional numerical method for precise computation and the surface panel method for rapid engineering prediction. Detailed flow field analysis for Mars exploration mission was performed by carrying on a series of fully three-dimensional Navier-Stokes computations. The static aerodynamic performance was then discussed, including the surface pressure, lift and drag coefficient, lift-to-drag ratio with the numerical and engineering method. Computation results shown that the shock layer is thin because of lower effective specific heat ratio, and that calculated results from both methods agree well with each other, and is consistent with the reference data. Aerodynamic performance analysis shows that CG location determines trim characteristics and pitch stability, and certain radially and axially shift of the CG location can alter the capsule lifting entry performance, which is of vital significance for the aerodynamic configuration des0ign and inner instrument layout of the Mars entry capsule.

Keywords: Mars entry capsule, static aerodynamics, computational fluid dynamics, hypersonic

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2407 Comparative Study of Concrete Filled Steel I-Girder Bridge with Conventional Type of Bridge

Authors: Waheed Ahmad Safi, Shunichi Nakamura, Abdul Habib Ghaforzai

Abstract:

Steel and concrete composite bridge with concrete filled steel I-girder (CFIG) was proposed and FEM and laboratory tests were conducted to analysis bending and shear behavior. The proposed form of structural steel I-section is mainly used at the intermediate support zone by placing infilled concrete into the top and bottom flanges of steel I-section to resist negative bending moment. The bending and shear tests were carried out to find out the significance of CFIG section. The result for test showing that the bending and shear capacity of proposed CFIG is at least 3 times and 2 times greater than conventional steel I-section (IG) respectively. Finite element study was also carried out to ensure the result for laboratory tests due to bending and shear behavior and load transfer behavior of proposed structural form. Finite element result result agreed the test result. A design example was carried out for a four-span continuous highway bridge and design method was established.

Keywords: bending strength, concrete filled steel I-girder, steel I-girder, FEM, limit states design and shear strength

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2406 Evaluating the Effectiveness of Animated Videos in Learning Economics

Authors: J. Chow

Abstract:

In laboratory settings, this study measured and reported the effects of undergraduate students watching animated videos on learning microeconomics as compared with the effectiveness of reading written texts. The study described an experiment on learning microeconomics in higher education using two different types of learning materials. It reported the effectiveness on microeconomics learning of watching animated videos and reading written texts. Undergraduate students in the university were randomly assigned to either a ‘video group’ or a ‘text group’ in the experiment. Previously-validated multiple-choice questions on fundamental concepts of microeconomics were administered. Both groups showed improvement between the pre-test and post-test. The experience of learning using text and video materials was also assessed. After controlling the student characteristics variables, the analyses showed that both types of materials showed comparable level of perceived learning experience. The effect size and statistical significance of these results supported the hypothesis that animated video is an effective alternative to text materials as a learning tool for students. The findings suggest that such animated videos may support teaching microeconomics in higher education.

Keywords: animated videos for education, laboratory experiment, microeconomics education, undergraduate economics education

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2405 Integrating and Evaluating Computational Thinking in an Undergraduate Marine Science Course

Authors: Dana Christensen

Abstract:

Undergraduate students, particularly in the environmental sciences, have difficulty displaying quantitative skills in their laboratory courses. Students spend time sampling in the field, often using new methods, and are expected to make sense of the data they collect. Computational thinking may be used to navigate these new experiences. We developed a curriculum for the marine science department at a small liberal arts college in the Northeastern United States based on previous computational thinking frameworks. This curriculum incorporates marine science data sets with specific objectives and topics selected by the faculty at the College. The curriculum was distributed to all students enrolled in introductory marine science classes as a mandatory module. Two pre-tests and post-tests will be used to quantitatively assess student progress on both content-based and computational principles. Student artifacts are being collected with each lesson to be coded for content-specific and computational-specific items in qualitative assessment. There is an overall gap in marine science education research, especially curricula that focus on computational thinking and associated quantitative assessment. The curricula itself, the assessments, and our results may be modified and applied to other environmental science courses due to the nature of the inquiry-based laboratory components that use quantitative skills to understand nature.

Keywords: marine science, computational thinking, curriculum assessment, quantitative skills

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2404 Soil/Phytofisionomy Relationship in Southeast of Chapada Diamantina, Bahia, Brazil

Authors: Marcelo Araujo da Nóbrega, Ariel Moura Vilas Boas

Abstract:

This study aims to characterize the physicochemical aspects of the soils of southeastern Chapada Diamantina - Bahia related to the phytophysiognomies of this area, rupestrian field, small savanna (savanna fields), small dense savanna (savanna fields), savanna (Cerrado), dry thorny forest (Caatinga), dry thorny forest/savanna, scrub (Carrasco - ecotone), forest island (seasonal semi-deciduous forest - Capão) and seasonal semi-deciduous forest. To achieve the research objective, soil samples were collected in each plant formation and analyzed in the soil laboratory of ESALQ - USP in order to identify soil fertility through the determination of pH, organic matter, phosphorus, potassium, calcium, magnesium, potential acidity, sum of bases, cation exchange capacity and base saturation. The composition of soil particles was also checked; that is, the texture, step made in the terrestrial ecosystems laboratory of the Department of Ecology of USP and in the soil laboratory of ESALQ. Another important factor also studied was to show the variations in the vegetation cover in the region as a function of soil moisture in the different existing physiographic environments. Another study carried out was a comparison between the average soil moisture data with precipitation data from three locations with very different phytophysiognomies. The soils found in this part of Bahia can be classified into 5 classes, with a predominance of oxisols. All of these classes have a great diversity of physical and chemical properties, as can be seen in photographs and in particle size and fertility analyzes. The deepest soils are located in the Central Pediplano of Chapada Diamantina where the dirty field, the clean field, the executioner and the semideciduous seasonal forest (Capão) are located, and the shallower soils were found in the rupestrian field, dry thorny forest, and savanna fields, the latter located on a hillside. As for the variations in water in the region's soil, the data indicate that there were large spatial variations in humidity in both the rainy and dry periods.

Keywords: Bahia, Brazil, chapada diamantina, phytophysiognomies, soils

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2403 Additive Manufacturing with Ceramic Filler

Authors: Irsa Wolfram, Boruch Lorenz

Abstract:

Innovative solutions with additive manufacturing applying material extrusion for functional parts necessitate innovative filaments with persistent quality. Uniform homogeneity and a consistent dispersion of particles embedded in filaments generally require multiple cycles of extrusion or well-prepared primal matter by injection molding, kneader machines, or mixing equipment. These technologies commit to dedicated equipment that is rarely at the disposal in production laboratories unfamiliar with research in polymer materials. This stands in contrast to laboratories that investigate complex material topics and technology science to leverage the potential of 3-D printing. Consequently, scientific studies in labs are often constrained to compositions and concentrations of fillersofferedfrom the market. Therefore, we introduce a prototypal laboratory methodology scalable to tailoredprimal matter for extruding ceramic composite filaments with fused filament fabrication (FFF) technology. - A desktop single-screw extruder serves as a core device for the experiments. Custom-made filaments encapsulate the ceramic fillers and serve with polylactide (PLA), which is a thermoplastic polyester, as primal matter and is processed in the melting area of the extruder, preserving the defined concentration of the fillers. Validated results demonstrate that this approach enables continuously produced and uniform composite filaments with consistent homogeneity. Itis 3-D printable with controllable dimensions, which is a prerequisite for any scalable application. Additionally, digital microscopy confirms the steady dispersion of the ceramic particles in the composite filament. - This permits a 2D reconstruction of the planar distribution of the embedded ceramic particles in the PLA matrices. The innovation of the introduced method lies in the smart simplicity of preparing the composite primal matter. It circumvents the inconvenience of numerous extrusion operations and expensive laboratory equipment. Nevertheless, it deliversconsistent filaments of controlled, predictable, and reproducible filler concentration, which is the prerequisite for any industrial application. The introduced prototypal laboratory methodology seems capable for other polymer matrices and suitable to further utilitarian particle types beyond and above ceramic fillers. This inaugurates a roadmap for supplementary laboratory development of peculiar composite filaments, providing value for industries and societies. This low-threshold entry of sophisticated preparation of composite filaments - enabling businesses to create their own dedicated filaments - will support the mutual efforts for establishing 3D printing to new functional devices.

Keywords: additive manufacturing, ceramic composites, complex filament, industrial application

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2402 Investigation of the Acoustic Properties of Recycled Felt Panels and Their Application in Classrooms and Multi-Purpose Halls

Authors: Ivanova B. Natalia, Djambova Т. Svetlana, Hristev S. Ivailo

Abstract:

The acoustic properties of recycled felt panels have been investigated using various methods. Experimentally, the sound insulation of the panels has been evaluated for frequencies in the range of 600 Hz to 4000 Hz, utilizing a small-sized acoustic chamber. Additionally, the sound absorption coefficient for the frequency range of 63 Hz to 4000 Hz was measured according to the EN ISO 354 standard in a laboratory reverberation room. This research was deemed necessary after conducting reverberation time measurements of a university classroom following the EN ISO 3382-2 standard. The measurements indicated values of 2.86 s at 500 Hz, 3.23 s at 1000 Hz, and 2.53 s at 2000 Hz, which significantly exceeded the requirements set by the national regulatory framework (0.6s) for such premises. For this reason, recycled felt panels have been investigated in the laboratory, showing very good acoustic properties at high frequencies. To enhance performance in the low frequencies, the influence of the distance of the panel spacing was examined. Furthermore, the sound insulation of the panels was studied to expand the possibilities of their application, both for the acoustic treatment of educational and multifunctional halls and for sound insulation purposes (e.g., a suspended ceiling with an air gap passing from room to room). As a conclusion, a theoretical acoustic design of the classroom has been carried out with suggestions for improvements to achieve the necessary acoustic and aesthetic parameters for such rooms.

Keywords: acoustic panels, recycled felt, sound absorption, sound insulation, classroom acoustics

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2401 Findings in Vascular Catheter Cultures at the Laboratory of Microbiology of General Hospital during One Year

Authors: P. Christodoulou, M. Gerasimou, S. Mantzoukis, N. Varsamis, G. Kolliopoulou, N. Zotos

Abstract:

Abstract— Purpose: The Intensive Care Unit (ICU) environment is conducive to the growth of microorganisms. A variety of microorganisms gain access to the intravascular area and are transported throughout the circulatory system. Therefore, examination of the catheters used in ICU patients is of paramount importance. Material and Method: The culture medium is a catheter tip, which is enriched with Tryptic soy broth (TSB). After one day of incubation, the broth is passaged in the following selective media: Blood, Mac conkey No. 2, chocolate, Mueller Hinton, Chapman, and Saboureaud agar. The above selective media is incubated for 2 days. After this period, if any number of microbial colonies is detected, gram staining is performed and then the microorganisms are identified by biochemical techniques in the automated Microscan (Siemens) system followed by a sensitivity test in the same system using the minimum inhibitory concentration (MIC) technique. The sensitivity test is verified by a Kirby Bauer test. Results: In 2017, the Microbiology Laboratory received 84 catheters from the ICU. 42 were found positive. Of these, S. epidermidis was identified at 8, A. baumannii in 10, K. pneumoniae in 6, P. aeruginosa in 6, P. mirabilis in 3, S. simulans in 1, S. haemolyticus in 4, S. aureus in 3 and S. hominis in 1. Conclusions: The results show that the placement and maintenance of the catheters in ICU patients are relatively successful, despite the unfavorable environment of the unit.

Keywords: culture, intensive care unit, microorganisms, vascular catheters

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2400 Environmental Modeling of Storm Water Channels

Authors: L. Grinis

Abstract:

Turbulent flow in complex geometries receives considerable attention due to its importance in many engineering applications. It has been the subject of interest for many researchers. Some of these interests include the design of storm water channels. The design of these channels requires testing through physical models. The main practical limitation of physical models is the so called “scale effect”, that is, the fact that in many cases only primary physical mechanisms can be correctly represented, while secondary mechanisms are often distorted. These observations form the basis of our study, which centered on problems associated with the design of storm water channels near the Dead Sea, in Israel. To help reach a final design decision we used different physical models. Our research showed good coincidence with the results of laboratory tests and theoretical calculations, and allowed us to study different effects of fluid flow in an open channel. We determined that problems of this nature cannot be solved only by means of theoretical calculation and computer simulation. This study demonstrates the use of physical models to help resolve very complicated problems of fluid flow through baffles and similar structures. The study applies these models and observations to different construction and multiphase water flows, among them, those that include sand and stone particles, a significant attempt to bring to the testing laboratory a closer association with reality.

Keywords: open channel, physical modeling, baffles, turbulent flow

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2399 On the Fixed Rainfall Intensity: Effects on Overland Flow Resistance, Shear Velocity and on Soil Erosion

Authors: L. Mouzai, M. Bouhadef

Abstract:

Raindrops and overland flow both are erosive parameters but they do not act by the same way. The overland flow alone tends to shear the soil horizontally and concentrates into rills. In the presence of rain, the soil particles are removed from the soil surface in the form of a uniform sheet layer. In addition to this, raindrops falling on the flow roughen the water and soil surface depending on the flow depth, and retard the velocity, therefore influence shear velocity and Manning’s factor. To investigate this part, agricultural sandy soil, rainfall simulator and a laboratory soil tray of 0.2x1x3 m were the base of this work. Five overland flow depths of 0; 3.28; 4.28; 5.16; 5.60; 5.80 mm were generated under a rainfall intensity of 217.2 mm/h. Sediment concentration control is based on the proportionality of depth/microtopography. The soil loose is directly related to the presence of rain splash on thin sheet flow. The effect of shear velocity on sediment concentration is limited by the value of 5.28 cm/s. In addition to this, the rain splash reduces the soil roughness by breaking the soil crests. The rainfall intensity is the major factor influencing depth and soil erosion. In the presence of rainfall, the shear velocity of the flow is due to two simultaneous effects. The first, which is horizontal, comes from the flow and the second, vertical, is due to the raindrops.

Keywords: flow resistance, laboratory experiments, rainfall simulator, sediment concentration, shear velocity, soil erosion

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2398 Modeling Slow Crack Growth under Thermal and Chemical Effects for Fitness Predictions of High-Density Polyethylene Material

Authors: Luis Marquez, Ge Zhu, Vikas Srivastava

Abstract:

High-density polyethylene (HDPE) is one of the most commonly used thermoplastic polymer materials for water and gas pipelines. Slow crack growth failure is a well-known phenomenon in high-density polyethylene material and causes brittle failure well below the yield point with no obvious sign. The failure of transportation pipelines can cause catastrophic environmental and economic consequences. Using the non-destructive testing method to predict slow crack growth failure behavior is the primary preventative measurement employed by the pipeline industry but is often costly and time-consuming. Phenomenological slow crack growth models are useful to predict the slow crack growth behavior in the polymer material due to their ability to evaluate slow crack growth under different temperature and loading conditions. We developed a quantitative method to assess the slow crack growth behavior in the high-density polyethylene pipeline material under different thermal conditions based on existing physics-based phenomenological models. We are also working on developing an experimental protocol and quantitative model that can address slow crack growth behavior under different chemical exposure conditions to improve the safety, reliability, and resilience of HDPE-based pipeline infrastructure.

Keywords: mechanics of materials, physics-based modeling, civil engineering, fracture mechanics

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2397 Object-Based Flow Physics for Aerodynamic Modelling in Real-Time Environments

Authors: William J. Crowther, Conor Marsh

Abstract:

Object-based flow simulation allows fast computation of arbitrarily complex aerodynamic models made up of simple objects with limited flow interactions. The proposed approach is universally applicable to objects made from arbitrarily scaled ellipsoid primitives at arbitrary aerodynamic attitude and angular rate. The use of a component-based aerodynamic modelling approach increases efficiency by allowing selective inclusion of different physics models at run-time and allows extensibility through the development of new models. Insight into the numerical stability of the model under first order fixed-time step integration schemes is provided by stability analysis of the drag component. The compute cost of model components and functions is evaluated and compared against numerical benchmarks. Model static outputs are verified against theoretical expectations and dynamic behaviour using falling plate data from the literature. The model is applied to a range of case studies to demonstrate the efficacy of its application in extensibility, ease of use, and low computational cost. Dynamically complex multi-body systems can be implemented in a transparent and efficient manner, and we successfully demonstrate large scenes with hundreds of objects interacting with diverse flow fields.

Keywords: aerodynamics, real-time simulation, low-order model, flight dynamics

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2396 The Effectiveness of Prefabricated Vertical Drains for Accelerating Consolidation of Tunis Soft Soil

Authors: Marwa Ben Khalifa, Zeineb Ben Salem, Wissem Frikha

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The purpose of the present work is to study the consolidation behavior of highly compressible Tunis soft soil “TSS” by means of prefabricated vertical drains (PVD’s) associated to preloading based on laboratory and field investigations. In the first hand, the field performance of PVD’s on the layer of Tunis soft soil was analysed based on the case study of the construction of embankments of “Radès la Goulette” bridge project. PVD’s Geosynthetics drains types were installed with triangular grid pattern until 10 m depth associated with step-by-step surcharge. The monitoring of the soil settlement during preloading stage for Radès La Goulette Bridge project was provided by an instrumentation composed by various type of tassometer installed in the soil. The distribution of water pressure was monitored through piezocone penetration. In the second hand, a laboratory reduced tests are performed on TSS subjected also to preloading and improved with PVD's Mebradrain 88 (Mb88) type. A specific test apparatus was designed and manufactured to study the consolidation. Two series of consolidation tests were performed on TSS specimens. The first series included consolidation tests for soil improved by one central drain. In thesecond series, a triangular mesh of three geodrains was used. The evolution of degree of consolidation and measured settlements versus time derived from laboratory tests and field data were presented and discussed. The obtained results have shown that PVD’s have considerably accelerated the consolidation of Tunis soft soil by shortening the drainage path. The model with mesh of three drains gives results more comparative to field one. A longer consolidation time is observed for the cell improved by a single central drain. A comparison with theoretical analysis, basically that of Barron (1948) and Carillo (1942), was presented. It’s found that these theories overestimate the degree of consolidation in the presence of PVD.

Keywords: tunis soft soil, prefabricated vertical drains, acceleration of consolidation, dissipation of excess pore water pressures, radès bridge project, barron and carillo’s theories

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2395 Geotechnical and Mineralogical Properties of Clay Soils in the Second Organized Industrial Region, Konya, Turkey

Authors: Mustafa Yıldız, Ali Ulvi Uzer, Murat Olgun

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In this study, geotechnical and mineralogical properties of gypsum containing clay basis which form the ground of Second Organized Industrial Zone in Konya province have been researched through comprehensive field and laboratory experiments. Although sufficient geotechnical research has not been performed yet, an intensive structuring in the region continues at present. The study area consists of mid-lake sediments formed by gypsum containing soft silt-clay basis which evolves to a large area. To determine the soil profile and geotechnical specifications; 18 drilling holes were opened and disturbed / undisturbed soil samples have been taken through shelby tubes within 1.5m intervals. Tests have been performed on these samples to designate the index and strength properties of soil. Besides, at all drilling holes Standart Penetration Tests have been done within 1.5m intervals. For the purpose of determining the mineralogical characteristics of the soil; all rock and X-RD analysis have been carried out on 6 samples which were taken from various depths through the soil profile. Strength and compressibility characteristics of the soil were defined with correlations using laboratory and field test results. Unconfined compressive strength, undrained cohesion, compression index varies between 16 kN/m2 and 405.4 kN/m2, 6.5 kN/m2 and 72 kN/m2, 0.066 and 0.864, respectively.

Keywords: Konya second organized industrial region, strength, compressibility, soft clay

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2394 Correlative Study of Serum Interleukin-18 and Disease Activity, Functional Disability and Quality of Life in Rheumatoid Arthritis Patients

Authors: Hamdy Khamis Korayem, Manal Yehia Tayel, Abeer Shawky El Hadedy, Emmanuel Kamal Aziz Saba, Shimaa Badr Abdelnaby Badr

Abstract:

The aim of the current study was to demonstrate whether serum Interleukin-18 (IL-18) is increased in rheumatoid arthritis (RA) and its correlation with disease activity, functional disability and quality of life in RA patients. The study included 30 RA patients and 20 healthy normal control subjects. The RA patients were diagnosed according to the 2010 ACR/EULAR classification criteria for RA with the exclusion of those who had diabetes mellitus, endocrine disorders, associated rheumatologic diseases, viral hepatitis B or C and other diseases with increased serum IL-18 level. All patients were subjected to clinical evaluation of the musculoskeletal system. Disease activity was assessed by disease activity score 28 with 4 variables (DAS 28). Functional disability was assessed by health assessment questionnaire disability index (HAQ-DI). The quality of life was assessed by Short form-36 (SF-36) questionnaire. Radiological assessment of both hands and feet by Sharp/van der Heijde (SvH) scoring method. Laboratory parameters including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibody (ACPA) were assessed in patients and serum level of IL-18 in both patients and control subjects. There was no statistically significant difference between patient and control group as regards age and sex. Among patients, 29 % were females and the age range was between 25 to 55 years. Extra-articular manifestations were presented in 56.7% of the patients. The mean of DAS 28 score was 5.73±1.46 and that of HAQ-DI was 1.22±0.72 while that of SF-36 was 40.03±13.96. The level of serum IL-18 was significantly higher in patients than in the control subjects (P= 0.030). Serum IL-18 was correlated with ACPA among the patient group. There were no statistically significant correlations between serum IL-18 and DAS28, HAQ-DI, SF-36, total SvH score and the other laboratory results. In conclusion, IL-18 is significantly higher in RA patient than in healthy control subjects and positively correlated with ACPA level. IL-18 is associated with extra-articular manifestations. However, it is not correlated with other laboratory parameters, disease activity, functional disability, quality of life nor radiological severity.

Keywords: disease activity score, Interleukin-18, quality of life assessment, rheumatoid arthritis

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2393 Effect of Inclusion of Rubber on the Compaction Characteristics of Cement - MSWIFA- Clayey Soil Mixtures

Authors: Gehan Aouf, Diala Tabbal, Abd El Rahim Sabsabi, Rashad Aouf

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The aim of this study is to show the effect of adding cement municipal solid incineration fly ash and rubber as stabilizer materials on weak soil. A detailed experimental study was conducted in order to show the viability of using these admixtures in improving the maximum dry density and optimum moisture content of the composite soil. Soil samples were prepared by adding Rubber and Cement to municipal solid waste incineration fly-ash - oil mix at different percentages. Then, a series of laboratory tests were performed, namely: Sieve analysis, Atterberg limits tests, Unconfined compression test, and Proctor tests. Three different percentages of fly ash (10%, 20%, and 30%) MSWFA by total dry weight of soil and three different percentages of Portland cement (10%, 15%, and 20%) by total dry weight of the mix and 0%, 5%, 10% for Rubber by total dry weight of the mix were used to find the optimum value. The test results reveal that adding MSWIFA to the soil up to 20% increased the MDD of the mixture and decreased the OMC, then an opposite trend for results were found when the percentage of MSWIFA exceeded 20%. This is due to the low specific gravity of MSWIFA and to the greater water absorption of MSWIFA. The laboratory tests also indicate that adding Rubber to the mix Soil-MSWIFA-Cement decreases its MDD due to the low specific gravity of rubber and it affects a slight decrease in OMC because the rubber has low absorption of water.

Keywords: clayey soil, MSWIFA, proctor test, rubber

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2392 Inversion of PROSPECT+SAIL Model for Estimating Vegetation Parameters from Hyperspectral Measurements with Application to Drought-Induced Impacts Detection

Authors: Bagher Bayat, Wouter Verhoef, Behnaz Arabi, Christiaan Van der Tol

Abstract:

The aim of this study was to follow the canopy reflectance patterns in response to soil water deficit and to detect trends of changes in biophysical and biochemical parameters of grass (Poa pratensis species). We used visual interpretation, imaging spectroscopy and radiative transfer model inversion to monitor the gradual manifestation of water stress effects in a laboratory setting. Plots of 21 cm x 14.5 cm surface area with Poa pratensis plants that formed a closed canopy were subjected to water stress for 50 days. In a regular weekly schedule, canopy reflectance was measured. In addition, Leaf Area Index (LAI), Chlorophyll (a+b) content (Cab) and Leaf Water Content (Cw) were measured at regular time intervals. The 1-D bidirectional canopy reflectance model SAIL, coupled with the leaf optical properties model PROSPECT, was inverted using hyperspectral measurements by means of an iterative optimization method to retrieve vegetation biophysical and biochemical parameters. The relationships between retrieved LAI, Cab, Cw, and Cs (Senescent material) with soil moisture content were established in two separated groups; stress and non-stressed. To differentiate the water stress condition from the non-stressed condition, a threshold was defined that was based on the laboratory produced Soil Water Characteristic (SWC) curve. All parameters retrieved by model inversion using canopy spectral data showed good correlation with soil water content in the water stress condition. These parameters co-varied with soil moisture content under the stress condition (Chl: R2= 0.91, Cw: R2= 0.97, Cs: R2= 0.88 and LAI: R2=0.48) at the canopy level. To validate the results, the relationship between vegetation parameters that were measured in the laboratory and soil moisture content was established. The results were totally in agreement with the modeling outputs and confirmed the results produced by radiative transfer model inversion and spectroscopy. Since water stress changes all parts of the spectrum, we concluded that analysis of the reflectance spectrum in the VIS-NIR-MIR region is a promising tool for monitoring water stress impacts on vegetation.

Keywords: hyperspectral remote sensing, model inversion, vegetation responses, water stress

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2391 Analytical Performance of Cobas C 8000 Analyzer Based on Sigma Metrics

Authors: Sairi Satari

Abstract:

Introduction: Six-sigma is a metric that quantifies the performance of processes as a rate of Defects-Per-Million Opportunities. Sigma methodology can be applied in chemical pathology laboratory for evaluating process performance with evidence for process improvement in quality assurance program. In the laboratory, these methods have been used to improve the timeliness of troubleshooting, reduce the cost and frequency of quality control and minimize pre and post-analytical errors. Aim: The aim of this study is to evaluate the sigma values of the Cobas 8000 analyzer based on the minimum requirement of the specification. Methodology: Twenty-one analytes were chosen in this study. The analytes were alanine aminotransferase (ALT), albumin, alkaline phosphatase (ALP), Amylase, aspartate transaminase (AST), total bilirubin, calcium, chloride, cholesterol, HDL-cholesterol, creatinine, creatinine kinase, glucose, lactate dehydrogenase (LDH), magnesium, potassium, protein, sodium, triglyceride, uric acid and urea. Total error was obtained from Clinical Laboratory Improvement Amendments (CLIA). The Bias was calculated from end cycle report of Royal College of Pathologists of Australasia (RCPA) cycle from July to December 2016 and coefficient variation (CV) from six-month internal quality control (IQC). The sigma was calculated based on the formula :Sigma = (Total Error - Bias) / CV. The analytical performance was evaluated based on the sigma, sigma > 6 is world class, sigma > 5 is excellent, sigma > 4 is good and sigma < 4 is satisfactory and sigma < 3 is poor performance. Results: Based on the calculation, we found that, 96% are world class (ALT, albumin, ALP, amylase, AST, total bilirubin, cholesterol, HDL-cholesterol, creatinine, creatinine kinase, glucose, LDH, magnesium, potassium, triglyceride and uric acid. 14% are excellent (calcium, protein and urea), and 10% ( chloride and sodium) require more frequent IQC performed per day. Conclusion: Based on this study, we found that IQC should be performed frequently for only Chloride and Sodium to ensure accurate and reliable analysis for patient management.

Keywords: sigma matrics, analytical performance, total error, bias

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2390 Assessment of Water Quality Used for Irrigation: Case Study of Josepdam Irrigation Scheme

Authors: M. A. Adejumobi, J. O. Ojediran

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The aim of irrigation is to recharge the available water in the soil. Quality of irrigation water is essential for the yield and quality of crops produced, maintenance of soil productivity and protection of the environment. The analysis of irrigation water arises as a need to know the impact of irrigation water on the yield of crops, the effect, and the necessary control measures to rectify the effect of this for optimum production and yield of crops. This study was conducted to assess the quality of irrigation water with its performance on crop planted, in Josepdam irrigation scheme Bacita, Nigeria. Field visits were undertaken to identify and locate water supply sources and collect water samples from these sources; X1 Drain, Oshin, River Niger loop and Ndafa. Laboratory experiments were then undertaken to determine the quality of raw water from these sources. The analysis was carried for various parameters namely; physical and chemical analyses after water samples have been taken from four sources. The samples were tested in laboratory. Results showed that the raw water sources shows no salinity tendencies with SAR values less than 1me/l and Ecvaules at Zero while the pH were within the recommended range by FAO, there are increase in potassium and sulphate content contamination in three of the location. From this, it is recommended that there should be proper monitoring of the scheme by conducting analysis of water and soil in the environment, preferable test should be carried out at least one year to cover the impact of seasonal variations and to determine the physical and chemical analysis of the water used for irrigation at the scheme.

Keywords: irrigation, salinity, raw water quality, scheme

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2389 The European Research and Development Project Improved Nuclear Site Characterization for Waste Minimization in Decommissioning under Constrained Environment: Focus on Performance Analysis and Overall Uncertainty

Authors: M. Crozet, D. Roudil, T. Branger, S. Boden, P. Peerani, B. Russell, M. Herranz, L. Aldave de la Heras

Abstract:

The EURATOM work program project INSIDER (Improved Nuclear Site Characterization for Waste minimization in Decommissioning under Constrained Environment) was launched in June 2017. This 4-year project has 18 partners and aims at improving the management of contaminated materials arising from decommissioning and dismantling (D&D) operations by proposing an integrated methodology of characterization. This methodology is based on advanced statistical processing and modelling, coupled with adapted and innovative analytical and measurement methods, with respect to sustainability and economic objectives. In order to achieve these objectives, the approaches will be then applied to common case studies in the form of Inter-laboratory comparisons on matrix representative reference samples and benchmarking. Work Package 6 (WP6) ‘Performance analysis and overall uncertainty’ is in charge of the analysis of the benchmarking on real samples, the organisation of inter-laboratory comparison on synthetic certified reference materials and the establishment of overall uncertainty budget. Assessment of the outcome will be used for providing recommendations and guidance resulting in pre-standardization tests.

Keywords: decommissioning, sampling strategy, research and development, characterization, European project

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2388 Prevalence of Treponema pallidum Infection among HIV-Seroreactive Patients in Kano, Nigeria

Authors: Y. Mohammed, A. I. Kabuga

Abstract:

Sexually transmitted infections (STIs) have continued to be a major public health problem in sub-Saharan Africa especially with the recent resurgence of syphilis. Syphilis is a systemic disease caused by the bacterium, spirochete Treponema pallidum and has been reported as one of the common sexually transmitted infections (STIs) in Nigeria. Presence of genital ulcer disease from syphilis facilitates human immunodeficiency virus (HIV) transmission and their ¬diagnosis is essential for the proper management. Venereal Disease Research Laboratory (VDRL) test is used as a screening test for the diagnosis of syphilis. However, unusual VDRL test results have been reported in HIV-infected persons with syphilis. There are reports showing higher than expected VDRL titers as well as biological false positive in most of the studies. A negative Rapid Plasma Reagin (RPR) test or VDRL test result may not rule out syphilis in patients with HIV infection. For laboratory confirmation of syphilis, one specific Treponemal test, namely, Fluroscent Treponemal Antibody Absorption (FTA-ABS) test or Treponema Pallidum Haemagglutination Assay (TPHA) should be done along with VDRL. A prospective cross sectional study was conducted for 2 years from Jun, 2012 to Jun 2014 to determine the prevalence of syphilis in HIV-seroreactive patients at 5 selected HIV/AIDS treatment and counseling centers in Kano State, North Western, Nigeria. New HIV-Seroreactive patients who gave informed consent to participate in the study were recruited. Venereal Diseases Research Laboratory (VDRL) test for Syphilis screening was performed on the same sera samples which were collected for HIV testing. A total of 238 patients, 113 (47%) males and 125 (53%) females, were enrolled. In the present study, 238 HIV-seropositive patients were screened for syphilis by VDRL test. Out of these 238 cases, 72 (32%) patients were positive for TPHA and 8 (3.4%) patients were reactive for VDRL in various titers with an overall prevalence of 3.4%. All the eight patients who were reactive for VDRL test were also positive for TPHA test. In Conclusions, with high prevalence of syphilis among HIV-infected people from this study, it is recommended that serological testing for syphilis should be carried out in all patients with newly diagnosed HIV infection. Detection and treatment of STI should have a central role in HIV prevention and control. This will help in proper management of patients having STIs and HIV co infection.

Keywords: HIV, infections, STIs, syphilis

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2387 Microbial Contamination of Cell Phones of Health Care Workers: Case Study in Mampong Municipal Government Hospital, Ghana

Authors: Francis Gyapong, Denis Yar

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The use of cell phones has become an indispensable tool in the hospital's settings. Cell phones are used in hospitals without restrictions regardless of their unknown microbial load. However, the indiscriminate use of mobile devices, especially at health facilities, can act as a vehicle for transmitting pathogenic bacteria and other microorganisms. These potential pathogens become exogenous sources of infection for the patients and are also a potential health hazard for self and as well as family members. These are a growing problem in many health care institutions. Innovations in mobile communication have led to better patient care in diabetes, asthma, and increased in vaccine uptake via SMS. Notwithstanding, the use of cell phones can be a great potential source for nosocomial infections. Many studies reported heavy microbial contamination of cell phones among healthcare workers and communities. However, limited studies have been reported in our region on bacterial contamination on cell phones among healthcare workers. This study assessed microbial contamination of cell phones of health care workers (HCWs) at the Mampong Municipal Government Hospital (MMGH), Ghana. A cross-sectional design was used to characterize bacterial microflora on cell phones of HCWs at the MMGH. A total of thirty-five (35) swab samples of cell phones of HCWs at the Laboratory, Dental Unit, Children’s Ward, Theater and Male ward were randomly collected for laboratory examinations. A suspension of the swab samples was each streak on blood and MacConkey agar and incubated at 37℃ for 48 hours. Bacterial isolates were identified using appropriate laboratory and biochemical tests. Kirby-Bauer disc diffusion method was used to determine the antimicrobial sensitivity tests of the isolates. Data analysis was performed using SPSS version 16. All mobile phones sampled were contaminated with one or more bacterial isolates. Cell phones from the Male ward, Dental Unit, Laboratory, Theatre and Children’s ward had at least three different bacterial isolates; 85.7%, 71.4%, 57.1% and 28.6% for both Theater and Children’s ward respectively. Bacterial contaminants identified were Staphylococcus epidermidis (37%), Staphylococcus aureus (26%), E. coli (20%), Bacillus spp. (11%) and Klebsiella spp. (6 %). Except for the Children ward, E. coli was isolated at all study sites and predominant (42.9%) at the Dental Unit while Klebsiella spp. (28.6%) was only isolated at the Children’s ward. Antibiotic sensitivity testing of Staphylococcus aureus indicated that they were highly sensitive to cephalexin (89%) tetracycline (80%), gentamycin (75%), lincomycin (70%), ciprofloxacin (67%) and highly resistant to ampicillin (75%). Some of these bacteria isolated are potential pathogens and their presence on cell phones of HCWs could be transmitted to patients and their families. Hence strict hand washing before and after every contact with patient and phone be enforced to reduce the risk of nosocomial infections.

Keywords: mobile phones, bacterial contamination, patients, MMGH

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2386 Self-Tuning Dead-Beat PD Controller for Pitch Angle Control of a Bench-Top Helicopter

Authors: H. Mansor, S.B. Mohd-Noor, N. I. Othman, N. Tazali, R. I. Boby

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This paper presents an improved robust Proportional Derivative controller for a 3-Degree-of-Freedom (3-DOF) bench-top helicopter by using adaptive methodology. Bench-top helicopter is a laboratory scale helicopter used for experimental purposes which is widely used in teaching laboratory and research. Proportional Derivative controller has been developed for a 3-DOF bench-top helicopter by Quanser. Experiments showed that the transient response of designed PD controller has very large steady state error i.e., 50%, which is very serious. The objective of this research is to improve the performance of existing pitch angle control of PD controller on the bench-top helicopter by integration of PD controller with adaptive controller. Usually standard adaptive controller will produce zero steady state error; however response time to reach desired set point is large. Therefore, this paper proposed an adaptive with deadbeat algorithm to overcome the limitations. The output response that is fast, robust and updated online is expected. Performance comparisons have been performed between the proposed self-tuning deadbeat PD controller and standard PD controller. The efficiency of the self-tuning dead beat controller has been proven from the tests results in terms of faster settling time, zero steady state error and capability of the controller to be updated online.

Keywords: adaptive control, deadbeat control, bench-top helicopter, self-tuning control

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2385 Experimental Investigation on Freeze-Concentration Process Desalting for Highly Saline Brines

Authors: H. Al-Jabli

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Using the freeze-melting process for the disposing of high saline brines was the aim of the paper by confirming the performance estimation of the treatment system. A laboratory bench scale freezing technique test unit was designed, constructed, and tested at Doha Research Plant (DRP) in Kuwait. The principal unit operations that have been considered for the laboratory study are: ice crystallization, separation, washing, and melting. The applied process is characterized as “the secondary-refrigerant indirect freezing”, which is utilizing normal freezing concept. The high saline brine was used as definite feed water, i.e. average TDS of 250,000 ppm. Kuwait desalination plants were carried out in the experimental study to measure the performance of the proposed treatment system. Experimental analysis shows that the freeze-melting process is capable of dropping the TDS of the feed water from 249,482 ppm to 56,880 ppm of the freeze-melting process in the two-phase’s course, whereas overall recovery results of the salt passage and salt rejection are 31.11%, 19.05%, and 80.95%, correspondingly. Therefore, the freeze-melting process is encouraging for the proposed application, as it shows on the results, which approves the process capability of reducing a major amount of the dissolved salts of the high saline brine with reasonable sensible recovery. This process might be reasonable with other brine disposal processes.

Keywords: high saline brine, freeze-melting process, ice crystallization, brine disposal process

Procedia PDF Downloads 243
2384 Impact of Modifying the Surface Materials on the Radiative Heat Transfer Phenomenon

Authors: Arkadiusz Urzędowski, Dorota Wójcicka-Migasiuk, Andrzej Sachajdak, Magdalena Paśnikowska-Łukaszuk

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Due to the impact of climate changes and inevitability to reduce greenhouse gases, the need to use low-carbon and sustainable construction has increased. In this work, it is investigated how texture of the surface building materials and radiative heat transfer phenomenon in flat multilayer can be correlated. Attempts to test the surface emissivity are taken however, the trustworthiness of measurement results remains a concern since sensor size and thickness are common problems. This paper presents an experimental method to studies surface emissivity with use self constructed thermal sensors and thermal imaging technique. The surface of building materials was modified by mechanical and chemical treatment affecting the reduction of the emissivity. For testing the shaping surface of materials and mapping its three-dimensional structure, scanning profilometry were used in a laboratory. By comparing the results of laboratory tests and performed analysis of 3D computer fluid dynamics software, it can be shown that a change in the surface coverage of materials affects the heat transport by radiation between layers. Motivated by recent advancements in variational inference, this publication evaluates the potential use a dedicated data processing approach, and properly constructed temperature sensors, the influence of the surface emissivity on the phenomenon of radiation and heat transport in the entire partition can be determined.

Keywords: heat transfer, surface roughness, surface emissivity, radiation

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