Search results for: soft particle

Authors: Sait Ali Uymaz, Gülay Tezel

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This paper presents the comparison results on the performance of the Cuckoo Search (CS) algorithm for constrained optimization problems. For constraint handling, CS algorithm uses penalty method. CS algorithm is tested on thirteen well-known test problems and the results obtained are compared to Particle Swarm Optimization (PSO) algorithm. Mean, best, median and worst values were employed for the analyses of performance.

Keywords: cuckoo search, particle swarm optimization, constrained optimization problems, penalty method

Procedia PDF Downloads 557

Authors: Tamika Gordon

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As technology continues to progress every second, educational institutions attempt to stay abreast of the latest developments through the acquisition of technological devices. Within schools, soft and hard technologies have assisted with reaching more students and expedient communication. As schools continue to grow, the need for simultaneous communication and efficient feedback has grown, and technology has allowed for these avenues to be explored and incorporated within a variety of daily operations. With the rapid inclusion of technology comes the potential for less face-to-face interactions among stakeholders. Although technology plays an integral role in education, the elements of both soft and hard technological devices must be proportionally utilized and coexist for the overall advancement and longevity of organizations. Over 20 articles were referenced to obtain a multitude of views on technology reflecting effects for students and teachers. Throughout this literature review, the effects of technology in the workplace will be discussed including views of current researchers, pros and cons surrounding technological inclusion, and implications for future research and further consideration. Upon the completion of the literature review, the benefits and necessity of technology remained high, however, low availability of resources, limited exposure to technological devices, and decreasing soft skills remained high as well. Recommendations are made for proportionate balances of technology and face-to-face interactions in order to minimize societal, educational, and organizational gaps.

Keywords: communication, devices, education, organizations, technology

Procedia PDF Downloads 232

Authors: S. H. Chew, Z. X. Eng, K. E. Chuah, T. Y. Lim, H. M. A. Yim

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In recent years, geotextile tube has been widely used in the hydraulic engineering and dewatering industry. To construct a stable containment bund with geotextile tubes, the sand slurry is always the preference infilling material. However, the shortage of sand supply posts a problem in Singapore to adopt this construction method in the actual construction of long containment bund. Hence, utilizing the soft dredged clay or the excavated soft clay as the infilling material of geotextile tubes has a great economic benefit. There are any technical issues with using this soft clayey material as infilling material, especially on the excessive settlement and stability concerns. To minimize the shape deformation and settlement of geotextile tube associated with the use of this soft clay infilling material, a modified innovative infilling material is proposed – lightly cemented soft clay. The preliminary laboratory studies have shown that the dewatering mechanism via geotextile material of the tube skin, and the introduction of cementitious chemical action of the lightly cemented soft clay will accelerate the consolidation and improve the shear strength of infill material. This study aims to extend the study by conducting a pilot test of the geotextile tube filled with lightly cemented clay. This study consists of testing on a series of miniature geo-tubes and two full-size geotextile tube. In the miniature geo-tube tests, a number of small scaled-down size of geotextile tubes were filled with cemented clay (at water content of 150%) with cement content of 0% to 8% (by weight). The shear strength development of the lightly cemented clay under dewatering mechanism was evaluated using a modified in-situ Cone Penetration Test (CPT) at 0 days, 3 days, 7 days and 28 days after the infilling. The undisturbed soil samples of lightly cemented infilled clay were also extracted at 3-days and 7-days for triaxial tests and evaluation of final water content. The results suggested that the geotextile tubes filled with un-cemented soft clay experienced very significant shape change over the days (as control test). However, geotextile mini-tubes filled with lightly cemented clay experienced only marginal shape changed, even that the strength development of this lightly cemented clay inside the tube may not show significant strength gain at the early stage. The shape stability is believed to be due to the confinement effect of the geotextile tube with clay at non-slurry state. Subsequently, a full-scale instrumented geotextile tube filled with lightly cemented clay was performed. The extensive results of strain gauges and pressure transducers installed on this full-size geotextile tube demonstrated a substantial mobilization of tensile forces on the geotextile skin corresponding to the filling activity and the subsequent dewatering stage. Shape change and the in-fill material strength development was also monitored. In summary, the construction of containment bund with geotextile tube filled with lightly cemented clay is found to be technically feasible and stable with the use of the sufficiently strong (i.e. adequate tensile strength) geotextile tube, the adequate control on the dosage of cement content, and suitable water content of infilling soft clay material.

Keywords: cemented clay, containment bund, dewatering, geotextile tube

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Authors: Varvara Roubtsova, Mohamed Chekired

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

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

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Authors: Miroslava Zelinkova, Marcela Ondova

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Fly ash (FA) thanks to the significant presence of SiO2 and Al2O3 as the main components is a potential raw material for geopolymers production. Mechanical activation is a method for improving FA reactivity and also the porosity of final mixture; those parameters can be analysed through sorption properties. They have direct impact on the durability of fly ash based geopolymer mortars. In the paper, effect of FA fineness on sorption properties of geopolymers based on sodium silicate, as well as relationship between fly ash fineness and apparent density, compressive and flexural strength of geopolymers are presented. The best results in the evaluated area reached the sample H1, which contents the highest portion of particle under 20μm (100% of GFA). The interdependence of individual tested properties was confirmed for geopolymer mixtures corresponding to those in the cement based mixtures: higher is portion of fine particles < 20μm, higher is strength, density and lower are sorption properties. The compressive strength as well as sorption parameters of the geopolymer can be reasonably controlled by grinding process and also ensured by the higher share of fine particle (to 20μm) in total mass of the material.

Keywords: alkali activation, geopolymers, fly ash, particle fineness

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Authors: Esam I. Jassim

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The main aim of this paper is to demonstrate the prediction of the model capability of predicting the nucleation process, the growth rate, and the deposition potential of second phase particles in gas flowlines. The primary objective of the research is to predict the risk hazards involved in the marine transportation of compressed natural gas. However, the proposed model can be equally used for other applications including production and transportation of natural gas in any high-pressure flow-line. The proposed model employs the following three main components to approach the problem: computational fluid dynamics (CFD) technique is used to configure the flow field; the nucleation model is developed and incorporated in the simulation to predict the incipient hydrate particles size and growth rate; and the deposition of the gas/particle flow is proposed using the concept of the particle deposition velocity. These components are integrated in a comprehended model to locate the hydrate deposition in natural gas flowlines. The present research is prepared to foresee the deposition location of solid particles that could occur in a real application in Compressed Natural Gas loading and offloading. A pipeline with 120 m length and different sizes carried a natural gas is taken in the study. The location of particle deposition formed as a result of restriction is determined based on the procedure mentioned earlier and the effect of water content and downstream pressure is studied. The critical flow speed that prevents such particle to accumulate in the certain pipe length is also addressed.

Keywords: hydrate deposition, compressed natural gas, marine transportation, oceanography

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Authors: G. Ravindranath, S. Savitha

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This paper presents heat transfer analysis of single horizontal bare tube and heat transfer analysis of staggered arrangement of bare tube bundles bare tube bundles in gas-solid (air-solid) fluidized bed and predictions are done by using Artificial Neural Network (ANN) based on experimental data. Fluidized bed provide nearly isothermal environment with high heat transfer rate to submerged objects i.e. due to through mixing and large contact area between the gas and the particle, a fully fluidized bed has little temperature variation and gas leaves at a temperature which is close to that of the bed. Measurement of average heat transfer coefficient was made by local thermal simulation technique in a cold bubbling air-fluidized bed of size 0.305 m. x 0.305 m. Studies were conducted for single horizontal Bare Tube of length 305mm and 28.6mm outer diameter and for bare tube bundles of staggered arrangement using beds of large (average particle diameter greater than 1 mm) particle (raagi and mustard). Within the range of experimental conditions influence of bed particle diameter ( Dp), Fluidizing Velocity (U) were studied, which are significant parameters affecting heat transfer. Artificial Neural Networks (ANNs) have been receiving an increasing attention for simulating engineering systems due to some interesting characteristics such as learning capability, fault tolerance, and non-linearity. Here, feed-forward architecture and trained by back-propagation technique is adopted to predict heat transfer analysis found from experimental results. The ANN is designed to suit the present system which has 3 inputs and 2 out puts. The network predictions are found to be in very good agreement with the experimental observed values of bare heat transfer coefficient (hb) and nusselt number of bare tube (Nub).

Keywords: fluidized bed, large particles, particle diameter, ANN

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Authors: Jayotpaul Chaudhuri, Lutz Goedeke, Torsten Hallenga, Peter Ehrhard

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Purification of gases from aerosols or airborne particles via filters is widely applied in the industry and in our daily lives. This separation especially in the micron and submicron size range is a necessary step to protect the environment and human health. Fibrous filters are often employed due to their low cost and high efficiency. For designing any filter the two most important performance parameters are capture efficiency and pressure drop. Since the capture efficiency is directly proportional to the pressure drop which leads to higher operating costs, a detailed investigation of the separation mechanism is required to optimize the filter designing, i.e., to have a high capture efficiency with a lower pressure drop. Therefore a two-dimensional flow simulation around a single fiber using Ansys CFX and Matlab is used to get insight into the separation process. Instead of simulating a solid fiber, the present Ansys CFX model uses a fictitious domain approach for the fiber by implementing a momentum loss model. This approach has been chosen to avoid creating a new mesh for different fiber sizes, thereby saving time and effort for re-meshing. In a first step, only the flow of the continuous fluid around the fiber is simulated in Ansys CFX and the flow field data is extracted and imported into Matlab and the particle trajectory is calculated in a Matlab routine. This calculation is a Lagrangian, one way coupled approach for particles with all relevant forces acting on it. The key parameters for the simulation in both Ansys CFX and Matlab are the porosity ε, the diameter ratio of particle and fiber D, the fluid Reynolds number Re, the Reynolds particle number Rep, the Stokes number St, the Froude number Fr and the density ratio of fluid and particle ρf/ρp. The simulation results were then compared to the single fiber theory from the literature.

Keywords: BBO-equation, capture efficiency, CFX, Matlab, fibrous filter, particle trajectory

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Authors: Mohamed Amine Adaour, Mohamed Sadek Bachene, Mosaab Fortassi, Wafaa Siouda

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— Foot infections are responsible for a significant number of hospitalizations and amputations in diabetic patients. The objective of our study is to analyze and evaluate the management of diabetic foot in a surgical setting. A retrospective study was conducted based on a selected case of suspected diabetic foot infections of osteitis treated at the Mohamed Boudiaf hospital in Medea.The case was reiterated as a therapeutic charge, consisting of treating first the infection of the soft tissues, then the osteitis: biopsy after at least 15 days of cessation of antibiotic therapy. Successful treatment of osteitis was defined at the end of a follow-up period of complete wound healing, lack of bone resection/amputation surgery at the initial bone site during follow-up , Instead, biopsies are prescribed in the treatment of soft tissue infection. The mean duration of treatment for soft tissue infection was 2-3 weeks, the duration of the antibiotic-free window of therapy prior to bone biopsy was 2-4 weeks. This patient received medical management without surgical resection. The success rate for treating osteitis at one year was 73%, and healing at one year was 88%.It is often limited to a sausage of the foot at the cost of repeated amputations. The best management remains prevention, which necessarily involves setting up a specialized and adapted centre.

Keywords: diabetic foot, bone biopsy, osteitis, algeria

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Authors: Noha Mohammed Ismael Awad Eladal, Aala Shoukry Emara

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Background: Wound healing after dental implant surgery is critical to the procedure's success. The aim of this study was to explore the effects of rutin+vitamin C supplementation in wound healing following the placement of dental implants. Methodology: There were 20 participants in this randomized controlled clinical trial who needed dental implants to replace missing teeth. Patients were divided into two groups, and group A received dental implants. Group B received dental implants with vitamin C administration. Follow-up appointments were performed on day 3, day 7, and day 14 post-surgery, during which soft tissue healing and pain response scores were evaluated using the visual analog scale. Postoperative digital panoramas were taken immediately after surgery, 3 months and 6 months postoperatively. Changes in bone density along with the bone-implant interface at the mesial, distal and apical sides were assessed using the digora software. Results: An independent t-test was used to compare the means of variables between the two groups. At the same time, repeated measures were employed to compare the means of variables between two groups. ANOVA was used to compare bone density for the same group at different dates. Significant increased differences were observed at the mesial, distal and apical sides Surrounding the implants of both groups per time. However, the rate of increase was significantly higher in group B The mean difference at the mesial side after 6 months was 21.99 ± 5.48 in the group B and 14.21 ± 4.95 in group A, while it read 21.74 ± 3.56 in the group B and 10.78 ± 3.90 in group A at the distal side and was 18.90 ± 5.91 in the group B and 10.39 ± 3.49 group A at the apical side. Significance was recorded at P = 0.004, P = 0.0001, and 0.001 at the mesial, distal and apical sides respectively. The mean pain score and wound healing were significantly higher in group A as compared to group B, respectively. Conclusion: The rutin c + vitamin c group significantly promoted bone healing and speeded up the osseointegration process and improved soft tissue healing.

Keywords: osseointegration, soft tissue, rutin c, dental implant

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Authors: Mohamed Amine Adaour, Mohamed Sadek Bachene, Mosaab Fortassi, Wafaa Siouda

Abstract:

Foot infections are responsible for a significant number of hospitalizations and amputations in diabetic patients. The objective of our study is to analyze and evaluate the management of diabetic foot in a surgical setting. A retrospective study was conducted based on a selected case of suspected diabetic foot infections of osteitis treated at the Mohamed Boudiaf hospital in Medea. The case was reiterated as a therapeutic charge, consisting of treating first the infection of the soft tissues, then the osteitis: biopsy after at least 15 days of cessation of antibiotic therapy. Successful treatment of osteitis was defined at the end of a follow-up period of complete wound healing, lack of bone resection/amputation surgery at the initial bone site during follow-up , Instead, biopsies are prescribed in the treatment of soft tissue infection. The mean duration of treatment for soft tissue infection was 2-3 weeks, the duration of the antibiotic-free window of therapy prior to bone biopsy was 2-4 weeks. This patient received medical management without surgical resection. The success rate for treating osteitis at one year was 73%, and healing at one year was 88%.It is often limited to a sausage of the foot at the cost of repeated amputations. The best management remains prevention, which necessarily involves setting up a specialized and adapted centre.

Keywords: osteitis, antibiotic therapy, bone biopsy, diabetic foot

Procedia PDF Downloads 78

Authors: Mohamed Amine Adaour, Mohamed Sadek Bachene, Mosaab Fortassi, Wafaa Siouda

Abstract:

Foot infections are responsible for a significant number of hospitalizations and amputations in diabetic patients. The objective of our study is to analyze and evaluate the management of diabetic foot in a surgical setting. A retrospective study was conducted based on a selected case of suspected diabetic foot infections of osteitis treated at the Mohamed Boudiaf hospital in Medea.The case was reiterated as a therapeutic charge, consisting of treating first the infection of the soft tissues, then the osteitis: biopsy after at least 15 days of cessation of antibiotic therapy. Successful treatment of osteitis was defined at the end of a follow-up period of complete wound healing, lack of bone resection/amputation surgery at the initial bone site during follow-up , Instead, biopsies are prescribed in the treatment of soft tissue infection. The mean duration of treatment for soft tissue infection was 2-3 weeks, the duration of the antibiotic-free window of therapy prior to bone biopsy was 2-4 weeks. This patient received medical management without surgical resection. The success rate for treating osteitis at one year was 73%, and healing at one year was 88%.It is often limited to a sausage of the foot at the cost of repeated amputations. The best management remains prevention, which necessarily involves setting up a specialized and adapted centre.

Keywords: osteitis, antibiotic, biopsy, diabetic foot

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Authors: Seungyeong Choi, Namkyu Lee, Dong Il Shim, Young Mun Lee, Yong-Ki Park, Hyung Hee Cho

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Effect of the cross-sectional geometry on heat transfer and particle motion of circulating fluidized bed riser for CO₂ capture was investigated. Numerical simulation using Eulerian-eulerian method with kinetic theory of granular flow was adopted to analyze gas-solid flow consisting in circulating fluidized bed riser. Circular, square, and rectangular cross-sectional geometry cases of the same area were carried out. Rectangular cross-sectional geometries were analyzed having aspect ratios of 1: 2, 1: 4, 1: 8, and 1:16. The cross-sectional geometry significantly influenced the particle motion and heat transfer. The downward flow pattern of solid particles near the wall was changed. The gas-solid mixing degree of the riser with the rectangular cross section of the high aspect ratio was the lowest. There were differences in bed-to-wall heat transfer coefficient according to rectangular geometry with different aspect ratios.

Keywords: bed geometry, computational fluid dynamics, circulating fluidized bed riser, heat transfer

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Authors: Saraswati Verma, Ankit Batra

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In the modern day, structures are designed with a lot of complexities due to economical, aesthetical, and functional needs causing various levels of irregularities to be induced. In the past, several studies have repeatedly shown that irregular structures suffer more damage than regular structures during earthquakes. The present study makes an effort to study the contribution of the orientation of columns in the seismic behaviour of buildings with vertical irregularities namely, soft storey irregularity, mass irregularity and geometric irregularity. The response of the various models is analysed using sap2000 version 14. The parameters through which a comparative response is investigated are displacement, variation in the stiffness contribution, and inter-storey drift. Models with different configurations of column orientations were studied for each vertical irregularity and it was observed that column orientation contributed significantly in affecting a better seismic response. Square columns of the same cross-sectional area showed a good response as compared to that of rectangular columns. The study concludes that as displacement values for buildings with a soft storey and mass irregularity are very high, square columns could be used to minimise the effect of displacement in x and y-axis. In buildings with geometric irregularity, exterior column orientations can be played with to enhance the stiffness in the shorter direction to control the displacement and drift values in both x and y directions.

Keywords: soft storey, mass irregularity, geometric irregularity, column orientation, square column

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Authors: Amin Davoudi

Abstract:

Aim: New approaches have been introduced to improve soft tissue indices of the dental implants. This systematic review aimed to investigate the effect of computer-aided design and computer-assisted manufacture (CAD/CAM) zirconia (Zr) implant abutments on periodontal aspects. Materials and Methods: Five electronic databases were searched thoroughly based on prior defined MeSH and non-MeSH keywords. Clinical studies were collected via hand searches in English language journals up to September 2020. Interproximal papilla stability, papilla recession, pink and white esthetic score (PES, WES), bone and gingival margin levels, color, and contour of soft tissue were reviewed. Results: The initial literature search yielded 412 articles. After the evaluation of abstracts and full texts, six studies were eligible to be screened. The study design of the included studies was a prospective cohort (n=3) and randomized clinical trial (n=3). The outcome was found to be significantly better for Zr than titanium abutments, however, the studies did not show significant differences between stock and CAD/CAM abutments. Conclusion: Papilla fill, WES, PES, and the distance from the contact point to dental crest bone of adjacent tooth and inter-tooth–implant distance were not significantly different between Zr CAD/CAM and Zr stock abutments. However, soft tissue stability and recession index were better in Zr CAD/CAM abutments.

Keywords: zirconia, CADCAM, periodental, implant

Procedia PDF Downloads 101

Authors: Adaour Mohamed Amine, Bachene Mohamed Sadek, Fortassi Mosaab, Siouda Wafaa

Abstract:

Foot infections are responsible for a significant number of hospitalizations and amputations in diabetic patients. The objective of our study is to analyze and evaluate the management of diabetic foot in a surgical setting. A retrospective study was conducted based on a selected case of suspected diabetic foot infections of osteitis treated at the Mohamed Boudiaf hospital in Medea. The case was reiterated as a therapeutic charge, consisting of treating first the infection of the soft tissues, then the osteitis: biopsy after at least 15 days of cessation of antibiotic therapy. Successful treatment of osteitis was defined at the end of a follow-up period of complete wound healing, lack of bone resection/amputation surgery at the initial bone site during follow-up , Instead, biopsies are prescribed in the treatment of soft tissue infection. The mean duration of treatment for soft tissue infection was 2-3 weeks, the duration of the antibiotic-free window of therapy prior to bone biopsy was 2-4 weeks. This patient received medical management without surgical resection. The success rate for treating osteitis at one year was 73% and healing at one year was 88%.It is often limited to a sausage of the foot at the cost of repeated amputations. The best management remains prevention, which necessarily involves setting up a specialized and adapted centre.

Keywords: osteitis, antibiotic therapy, bone biopsy, diabetic foot

Procedia PDF Downloads 103

Authors: H. Shokouhmand, M. Degheh, B. Sajadi, H. Sobhani

Abstract:

The induct ultraviolet germicidal irradiation (UVGI) systems are broadly used nowadays and their utilization is widened every day. Even though these systems are not applicable individually, they are very suitable supplements for the traditional filtration systems. The amount of inactivated microorganisms is dependent on the air velocity, lamp power, fluence rate distribution, and also germicidal susceptibility of microorganisms. In this paper, these factors are investigated utilizing an air-microorganism two-phase numerical model. The eulerian-lagrangian method was used to have more detailed information on the history of each particle. The UVGI system was modeled in three steps including: 1) modeling the air flow, 2) modeling the discrete phase of particles, 3) modeling the UV intensity field, and 4) modeling the particle inactivation. The results from modeling different lamp arrangements and powers showed that the system functions better at more homogeneous irradiation distribution. Since increasing the air flow rate of the device results in increasing of particle inactivation rate, the optimal air velocity shall be adjusted in accordance with the microorganism production rate, and the air quality requirement using the curves represented in this paper.

Keywords: CFD, microorganism, two-phase flow, ultraviolet germicidal irradiation

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Authors: Julian Jaegers, Siegmar Wirtz, Viktor Scherer

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Wood pellets belong to the most established trade formats of wood-based fuels. Especially, because of the transportability and the storage properties, but also due to low moisture content, high energy density, and the homogeneous particle size and shape, wood pellets are well suited for power generation in power plants and for the use in automated domestic firing systems. Before they are thermally converted, wood pellets pass various transport and storage procedures. There they undergo different mechanical impacts, which leads to pellet breakage and abrasion and to an increase in fines. The fines lead to operational problems during storage, charging, and discharging of pellets, they can increase the risk of dust explosions and can lead to pollutant emissions during combustion. In the current work, the dependence of the formation of fines caused by breakage during pneumatic transport is analyzed experimentally and numerically. The focus lies on the influence of conveying velocity, pellet loading, pipe diameter, and the shape of pipe components like bends or couplings. A test rig has been built, which allows the experimental evaluation of the pneumatic transport varying the above-mentioned parameters. Two high-speed cameras are installed for the quantitative optical access to the particle-particle and particle-wall contacts. The particle size distribution of the bulk before and after a transport process is measured as well as the amount of fines produced. The experiments will be compared with results of corresponding DEM/CFD simulations to provide information on contact frequencies and forces. The contribution proposed will present experimental results and report on the status of the DEM/CFD simulations. The final goal of the project is to provide a better insight into pellet breakage during pneumatic transport and to develop guidelines ensuring a more gentle transport.

Keywords: DEM/CFD-simulation of pneumatic conveying, mechanical impact on wood pellets during transportation, pellet breakage, pneumatic transport of wood pellets

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Authors: Mathias Schlenk, Susanne Seibt, Sabine Rosenfeldt, Josef Breu, Stephan Foerster

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Thin liquid jets on micrometer scale play an important role in processing such as in fiber fabrication, inkjet printing, but also for sample delivery in modern synchrotron X-ray devices. In all these cases the liquid jets contain solvents and dissolved materials such as polymers, nanoparticles, fibers pigments or proteins. As liquid flow in liquid jets differs significantly from flow in capillaries and microchannels, particle localization and orientation will also be different. This is of critical importance for applications, which depend on well-defined homogeneous particle and fiber distribution and orientation in liquid jets. Investigations of particle orientation in liquid microjets of diluted solutions have been rare, despite their importance. With the arise of micro-focused X-ray beams it has become possible to scan across samples with micrometer resolution to locally analyse structure and orientation of the samples. In the present work, we used this method to scan across liquid microjets to determine the local distribution and orientation of anisotropic particles. The compromise wormlike block copolymer micelles as an example of long flexible fibrous structures, hectorite materials as a model of extended nanosheet structures, and gold nanorods as an illustration of short stiff cylinders to comprise all relevant anisotropic geometries. We find that due to the different velocity profile in the liquid jet, which resembles plug flow, the orientation of the particles which was generated in the capillary is lost or changed into non-oriented or bi-axially orientations depending on the geometrical shape of the particle.

Keywords: anisotropic particles, liquid microjets, reorientation, SAXS

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Authors: Eyuphan Manay

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In this study, it was aimed to determine the convective heat transfer characteristics of water-based silicon dioxide nanofluids (SiO₂) with particle volume fractions of 0.2 and 0.4% vol. Nanofluids were tested in a plate type heat exchanger with six plates. Plate type heat exchanger was manufactured from stainless steel. Water was driven in the hot flow side, and nanofluids were driven in the cold flow side. The thermal energy of the hot water was taken by nanofluids. Effect of the inlet temperature of the hot water was investigated on heat transfer performance of the nanofluids while the inlet temperature of the nanofluids was fixed. In addition, the effects of the particle volume fraction and the cold flow rate on the performance of the system were tested. Results showed that increasing inlet temperature of the hot flow caused heat transfer to enhance. The suspended solid particles into the carrier fluid also remarkably enhanced heat transfer, and, an increase in the particle volume fraction resulted in an increase in heat transfer.

Keywords: heat transfer enhancement, SiO₂-water, nanofluid, plate heat exchanger

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Authors: Sneha Thakur, Sanjeev Karmakar

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This paper proposed hybrid Particle Swarm Optimization (PSO) – Long-Short Term Memory (LSTM) model for groundwater level prediction. The evaluation of the performance is realized using the parameters: root mean square error (RMSE) and mean absolute error (MAE). Ground water level forecasting will be very effective for planning water harvesting. Proper calculation of water level forecasting can overcome the problem of drought and flood to some extent. The objective of this work is to develop a ground water level forecasting model using deep learning technique integrated with optimization technique PSO by applying 29 years data of Chhattisgarh state, In-dia. It is important to find the precise forecasting in case of ground water level so that various water resource planning and water harvesting can be managed effectively.

Keywords: long short-term memory, particle swarm optimization, prediction, deep learning, groundwater level

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Authors: Pim Terachinda, Witaya Wannasuphoprasit, Wasuwat Kitisomprayoonkul, Anan Srikiatkhachorn

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Restoration of hand function and dexterity remain challenges in rehabilitation after stroke. We have developed soft exoskeleton hand robot in which using tendon-driven mechanism. Finger flexion and extension can be triggered by a foot switch and force can be adjusted manually depending on patient’s grip strength. The objective of this study is to investigate feasibility and safety of this device. The study was done in 2 stroke patients with the strength of the finger flexors/extensors grade 1/0 and 3/1 on Medical Research Council scale, respectively. Grasp and release training was performed for 30 minutes. No complication was observed. Results demonstrated that the device is safe, and therapy can be tailored to individual patient’s need. However, further study is required to determine recovery and rehabilitation outcomes after training in patients after nervous system injury.

Keywords: hand, rehabilitation, robot, stroke

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Authors: Shahriar Ghammamy, Maryam Gholipoor

Abstract:

Metronidazole nano -powders with the average mean particle size around 90 nm were synthesized by high-energy milling using a planetary ball mill is provided. The Scattering factors, milling of time,the ball size and ball to powder ratio on the material properties powder by the Ray diffraction (XRD) study, scanning electron microscopy (SEM), IR. It has been observed that the density of nano-sized grinding balls as ball to powder ratio depends. Using the dispersion factor, the density Can be reduced below the initial particle size was achieved.

Keywords: metronidazole, ball-milling, nanoparticles, characterization, XRD diffraction

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Authors: Wahiba Mohguen, Raïs El’hadi Bekka

Abstract:

This paper presents a denoising method called EMD-Custom that was based on Empirical Mode Decomposition (EMD) and the modified Customized Thresholding Function (Custom) algorithms. EMD was applied to decompose adaptively a noisy signal into intrinsic mode functions (IMFs). Then, all the noisy IMFs got threshold by applying the presented thresholding function to suppress noise and to improve the signal to noise ratio (SNR). The method was tested on simulated data and real ECG signal, and the results were compared to the EMD-Based signal denoising methods using the soft and hard thresholding. The results showed the superior performance of the proposed EMD-Custom denoising over the traditional approach. The performances were evaluated in terms of SNR in dB, and Mean Square Error (MSE).

Keywords: customized thresholding, ECG signal, EMD, hard thresholding, soft-thresholding

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Authors: Mohamed Ali Abdennadher

Abstract:

Digital rock physics, an emerging field leveraging advanced imaging and numerical techniques, offers a promising approach to investigating the mechanical properties of granular materials without extensive physical experiments. This study focuses on using X-Ray Computed Tomography (CT) to capture the three-dimensional (3D) structure of coarse-grained soil at the particle level, combined with finite element analysis (FEA) to simulate the soil's behavior under compression. The primary goal is to establish a reliable virtual testing framework that can replicate laboratory results and offer deeper insights into soil mechanics. The methodology involves acquiring high-resolution CT scans of coarse-grained soil samples to visualize internal particle morphology. These CT images undergo processing through noise reduction, thresholding, and watershed segmentation techniques to isolate individual particles, preparing the data for subsequent analysis. A custom Python script is employed to extract particle shapes and conduct a statistical analysis of particle size distribution. The processed particle data then serves as the basis for creating a finite element model comprising approximately 500 particles subjected to one-dimensional compression. The FEA simulations explore the effects of mesh refinement and friction coefficient on stress distribution at grain contacts. A multi-layer meshing strategy is applied, featuring finer meshes at inter-particle contacts to accurately capture mechanical interactions and coarser meshes within particle interiors to optimize computational efficiency. Despite the known challenges in parallelizing FEA to high core counts, this study demonstrates that an appropriate domain-level parallelization strategy can achieve significant scalability, allowing simulations to extend to very high core counts. The results show a strong correlation between the finite element simulations and laboratory compression test data, validating the effectiveness of the virtual experiment approach. Detailed stress distribution patterns reveal that soil compression behavior is significantly influenced by frictional interactions, with frictional sliding, rotation, and rolling at inter-particle contacts being the primary deformation modes under low to intermediate confining pressures. These findings highlight that CT data analysis combined with numerical simulations offers a robust method for approximating soil behavior, potentially reducing the need for physical laboratory experiments.

Keywords: X-Ray computed tomography, finite element analysis, soil compression behavior, particle morphology

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Authors: Iddy Iddy, Qin Jiang, Changkuan Zhang

Abstract:

This paper addresses the hydraulic performance of curtain wall breakwaters as a coastal structure protection based on the particles method modelling. The hydraulic functions of curtain wall as wave barriers by reflecting large parts of incident waves through the vertical wall, a part transmitted and a particular part was dissipating the wave energies through the eddy flows formed beneath the lower end of the plate. As a Lagrangian particle, the Moving Particle Semi-implicit (MPS) method which has a robust capability for numerical representation has proven useful for design of structures application that concern free-surface hydrodynamic flow, such as wave breaking and overtopping. In this study, a vertical two-dimensional numerical model for the simulation of violent flow associated with the interaction between the curtain-wall breakwaters and progressive water waves is developed by MPS method in which a higher precision pressure gradient model and free surface particle recognition model were proposed. The wave transmission, reflection, and energy dissipation of the vertical wall were experimentally and theoretically examined. With the numerical wave flume by particle method, very detailed velocity and pressure fields around the curtain-walls under the action of waves can be computed in each calculation steps, and the effect of different wave and structural parameters on the hydrodynamic characteristics was investigated. Also, the simulated results of temporal profiles and distributions of velocity and pressure in the vicinity of curtain-wall breakwaters are compared with the experimental data. Herein, the numerical investigation of hydraulic performance of curtain wall breakwaters indicated that the incident wave is largely reflected from the structure, while the large eddies or turbulent flows occur beneath the curtain-wall resulting in big energy losses. The improved MPS method shows a good agreement between numerical results and analytical/experimental data which are compared to related researches. It is thus verified that the improved pressure gradient model and free surface particle recognition methods are useful for enhancement of stability and accuracy of MPS model for water waves and marine structures. Therefore, it is possible for particle method (MPS method) to achieve an appropriate level of correctness to be applied in engineering fields through further study.

Keywords: curtain wall breakwaters, free surface flow, hydraulic performance, improved MPS method

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Authors: Mohammedi Ferhate

Abstract:

This paper deals with the generalized the notion of the function of wave a micro particle moving free, the concept of the linear operator in the representation function delta of Dirac which is a generalization of the symbol of Kronecker to the case of a continuous variation of the sizes concerned with the condition of orthonormation of the Eigen functions the use of linear operators and their Eigen functions in connection with the solution of given differential equations, it is of interest to study the properties of the operators themselves and determine which of them follow purely from the nature of the operators, without reference to specific forms of Eigen functions. The models simulation examples are also presented.

Keywords: function, operator, simulation, wave

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Authors: Wei Wang, Martin Chen

Abstract:

The reconstitution behaviours of nutritional products could impact user experience. Reconstitution issues such as lump formation and white flecks sticking to bottles surfaces could be very unappealing for the consumers in milk preparation. The controlling steps in dissolving instant milk powders include wetting, swelling, sinking, dispersing, and dissolution as in the literature. Each stage happens simultaneously with the others during milk preparation, and it is challenging to isolate and measure each step individually. This study characterized three adult nutritional products for different properties including particle size, density, dispersibility, stickiness, and capillary wetting to understand the relationship between powder physical properties and their reconstitution behaviours. From the results, the formation of clumps can be caused by different factors limiting the critical steps of powder reconstitution. It can be caused by small particle size distribution, light particle density limiting powder wetting, or the rapid swelling and dissolving of particle surface materials to impede water penetration in the capillary channels formed by powder agglomerates. For the grain or white flecks formation in milk preparation, it was believed to be controlled by dissolution speed of the particles after dispersion into water. By understanding those relationship between fundamental powder structure and their user experience in reconstitution, this information provides us new and multiple perspectives on how to improve the powder characteristics in the commercial manufacturing.

Keywords: characterization, dairy nutritional powder, physical property, reconstitution

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Authors: Sung Uk Park, Young Su Kang, Sangmo Kang, Young Kweon Suh

Abstract:

Mineral product, waste concrete (fine aggregates), waste in the optical field, industry, and construction employ separators to separate solids and classify them according to their size. Various sorting machines are used in the industrial field such as those operating under electrical properties, centrifugal force, wind power, vibration, and magnetic force. Study on separators has been carried out to contribute to the environmental industry. In this study, we perform CFD analysis for understanding the basic mechanism of the separation of waste concrete (fine aggregate) particles from air with a machine built with a rotor with blades. In CFD, we first performed two-dimensional particle tracking for various particle sizes for the model with 1 degree, 1.5 degree, and 2 degree angle between each blade to verify the boundary conditions and the method of rotating domain method to be used in 3D. Then we developed 3D numerical model with ANSYS CFX to calculate the air flow and track the particles. We judged the capability of particle separation for given size by counting the number of particles escaping from the domain toward the exit among 10 particles issued at the inlet. We confirm that particles experience stagnant behavior near the exit of the rotating blades where the centrifugal force acting on the particles is in balance with the air drag force. It was also found that the minimum particle size that can be separated by the machine with the rotor is determined by its capability to stay at the outlet of the rotor channels.

Keywords: environmental industry, separator, CFD, fine aggregate

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Authors: Muzamir Hasan, Anas Bazirgan

Abstract:

Granular columns is a technique that has the properties of improving bearing capacity, accelerating the dissipation of excess pore water pressure and reducing settlement in a weak soft soil. This research aims to investigate the role of Polypropylene column in improving the shear strength and compressibility of soft reconstituted kaolin clay by determining the effects of area replacement ratio, height penetrating ratio and volume replacement ratio of a singular Polypropylene column on the strength characteristics. Reinforced kaolin samples were subjected to Unconfined Compression (UCT) and Unconsolidated Undrained (UU) triaxial tests. The kaolin samples were 50 mm in diameter and 100 mm in height. Using the PP column reinforcement, with an area replacement ratio of 0.8, 0.5 and 0.3, shear strength increased approximately 5.27%, 26.22% and 64.28%, and 37.14%, 42.33% and 51.17%, for area replacement ratios of 25% and 10.24%. Meanwhile, UU testing showed an increase in shear strength of 24.01%, 23.17% and 23.49% and 28.79%, 27.29 and 30.81% for the same ratios. Based on the UCT results, the undrained shear strength generally increased with the decrease in height penetration ratio. However, based on the UU test results Mohr-Coulomb failure criteria, the installation of Polypropylene columns did not show any significant difference in effective friction angle. However, there was an increase in the apparent cohesion and undrained shear strength of the kaolin clay. In conclusion, Polypropylene column greatly improved the shear strength; and could therefore be implemented in reducing the cost of soil improvement as a replacement for non-renewable materials.

Keywords: polypropylene, UCT, UU test, Kaolin S300, ground improvement

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