Search results for: partial slip

Authors: I. Ruzaina, A. B. Rashid, M. S. Halimahton Zahrah, C. S. Cheow, M. S. Adi

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This study was conducted to determine the potential of palm stearin (PS) as edible coating materials for fruits. The palm stearin was blended with 20-80% palm kernel olein (PKOo) and the properties of the blends were evaluated in terms of the slip melting point (SMP), solid fat content (SFC), fatty acid and triacylglycerol compositions (TAG), and polymorphism. Blending of PS with PKOo reduced the SMP, SFC, altered the FAC and TAG composition and changed the crystal polymorphism from β to mixture of β and β′. The changes in the physicochemical properties of PS were due to the replacement of the high melting TAG in PS with medium chain TAG in PKOo. From the analysis, 1:1 and 3:2 were the better PSPKOo blend formulations in slowing down the weight loss, respiration gases and gave better appearance when compared to other PSPKOo blends formulations.

Keywords: guava, palm stearin, palm kernel olein, physicochemical

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Authors: Ahmed Boutejdar, Bishoy I. Halim, Soumia El Hani, Larbi Bellarbi, Amal Afyf

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In this paper, a planar monopole antenna for multi band applications is proposed. The antenna structure operates at three operating frequencies at 3.7, 6.2, and 13.5 GHz which cover different communication frequency ranges. The antenna consists of a quasi-modified rectangular radiating patch with a partial ground plane and two parasitic elements (open-loop-ring resonators) to serve as coupling-bridges. A stepped cut at lower corners of the radiating patch and the partial ground plane are used, to achieve the multiband features. The proposed antenna is manufactured on the FR4 substrate and is simulated and optimized using High Frequency Simulation System (HFSS). The antenna topology possesses an area of 30.5 x 30 x 1.6 mm³. The measured results demonstrate that the candidate antenna has impedance bandwidths for 10 dB return loss and operates from 3.80 – 3.90 GHz, 4.10 – 5.20 GHz, 11.2 – 11.5 GHz and from 12.5 – 14.0 GHz, which meet the requirements of the wireless local area network (WLAN), worldwide interoperability for microwave access (WiMAX), C- (Uplink) and Ku- (Uplink) band applications. Acceptable agreement is obtained between measurement and simulation results. Experimental results show that the antenna is successfully simulated and measured, and the tri-band antenna can be achieved by adjusting the lengths of the three elements and it gives good gains across all the operation bands.

Keywords: planar monopole antenna, FR4 substrate, HFSS, WLAN, WiMAX, C and Ku

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Authors: Hussein Abbas Jebur, Yasir Abd Ulrazzaq

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This study was carried out at the farm of El-Gemmaiza Agriculture Research Station, El-Garbia Governorate Egypt, to determine the performance characteristics of an agricultural transport. The performance of this transportation was compared between three surfaces (asphalt, dusty and field). The study was concentrated on the rate of drawbar pull, slip ratio, tractive efficiency and specific energy per unit area. The comparison was made under three different surfaces (asphalt, dusty and field), different traveling speeds from (3.38 to 6.55 km/h) and variable weights (0 and 300 kg). The results showed that the highest value of the tractive efficiency 60.20% was obtained at traveling speed 4.00 km/h with weight on the rear wheel on the asphalt surface. The highest value of specific energy 1.93 kW.h/ton during use of ballast on rear tractor wheels at traveling speed 3.38 km/h on the field surface.

Keywords: tractor, energy, transportation, weight, power

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Authors: Bong-Keun Jung, Jung-Yeon Kim

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The aim of this study was to investigate usability of detachable brake system for moving apparatus such as baby strollers, manual wheelchairs or walkers. The current brake system was proposed to prevent that moving apparatus slip on sloping roadways when unattended as current built-in manual brake for the moving apparatus is not able to react for the matter. The developed detachable brake system enacted by force sensor on the hand grip showed the possibilities to prevent unexpected accident due to uncontrolled stroller or wheelchair use. To investigate the quality and acceptance of this new technology, standard stroller testbed was built and the use of moving apparatus which attached to the proposed brake system was analyzed through video recording. Additional usability questionnaires were given to test users for measuring usability issues.

Keywords: brake system, stroller, wheelchair, usability test

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Authors: Melike Aydoğan, Dürdane Öztürk

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Let H(D) be the linear space of all analytic functions defined on the open unit disc. A log-harmonic mappings is a solution of the nonlinear elliptic partial differential equation where w(z) ∈ H(D) is second dilatation such that |w(z)| < 1 for all z ∈ D. The aim of this paper is to define some inequalities of starlike logharmonic functions of order α(0 ≤ α ≤ 1).

Keywords: starlike log-harmonic functions, univalent functions, distortion theorem

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Authors: Maedeh Pourmajidian, Joseph R. McDermid

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Advanced High Strength Steels are revolutionizing both the steel and automotive industries due to their high specific strength and ability to absorb energy during crash events. This allows manufacturers to design vehicles with significantly increased fuel efficiency without compromising passenger safety. To maintain the structural integrity of the fabricated parts, they must be protected from corrosion damage through continuous hot-dip galvanizing process, which is challenging due to selective oxidation of Mn and Si on the surface of this AHSSs. The effects of process atmosphere oxygen partial pressure and small additions of Sn on the selective oxidation of a medium-Mn C-6Mn-2Si advanced high strength steel was investigated. Intercritical annealing heat treatments were carried out at 690˚C in an N2-5%H2 process atmosphere under dew points ranging from –50˚C to +5˚C. Surface oxide chemistries, morphologies, and thicknesses were determined at a variety of length scales by several techniques, including SEM, TEM+EELS, and XPS. TEM observations of the sample cross-sections revealed the transition to internal oxidation at the +5˚C dew point. EELS results suggested that the internal oxides network was composed of a multi-layer oxide structure with varying chemistry from oxide core towards the outer part. The combined effect of employing a known surface active element as a function of process atmosphere on the surface structure development and the possible impact on reactive wetting of the steel substrates by the continuous galvanizing zinc bath will be discussed.

Keywords: 3G AHSS, hot-dip galvanizing, oxygen partial pressure, selective oxidation

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Authors: Valentin Nickolai, Florian Pfeffel, Christian Louis Kühner

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In many industrialized nations, the demand for skilled workers rises, causing the current market for employees to be more candidate-driven than employer-driven. Therefore, losing highly skilled and experienced employees due to early or partial retirement negatively impacts firms. Therefore, finding new ways to incentivize older employees (Silver Workers) to stay longer with the company and in their job can be crucial for the success of a firm. This study analyzes how working remotely can be a valid incentive for experienced Silver Workers to stay in their job and instead work from home with more flexible working hours. An online survey with n = 684 respondents, who are employed in the service sector, has been conducted based on 13 constructs that influence job satisfaction. These have been further categorized into three groups “classic influencing factors,” “influencing factors changed by remote working,” and new remote working influencing factors,” and were analyzed using structural equation modeling (SEM). Here, Cronbach’s alpha of the individual constructs was shown to be suitable. Furthermore, the construct validity of the constructs was confirmed by face validity, content validity, convergent validity (AVE > 0.5: CR > 0.7), and discriminant validity. Additionally, confirmatory factor analysis (CFA) confirmed the model fit for the investigated sample (CMIN/DF: 2.567; CFI: 0.927; RMSEA: 0.048). It was shown in the SEM-analysis that the influencing factor on job satisfaction, “identification with the work,” is the most significant with β = 0.540, followed by “Appreciation” (β = 0.151), “Compensation” (β = 0.124), “Work-Life-Balance” (β = 0.116), and “Communication and Exchange of Information” (β = 0.105). While the significance of each factor can vary depending on the work model, the SEM-analysis also shows that the identification with the work is the most significant factor in all three work models mentioned above and, in the case of the traditional office work model, it is the only significant influencing factor. The study shows that employees between the ages of 56 and 65 years have the highest job satisfaction when working entirely from home or remotely. Furthermore, their job satisfaction score of 5.4 on a scale from 1 (very dissatisfied) to 7 (very satisfied) is the highest amongst all age groups in any of the three work models. Due to the significantly higher job satisfaction, it can be argued that giving Silver Workers the offer to work from home or remotely can incentivize them not to opt for early retirement or partial retirement but to stay in their job full-time Furthermore, these findings can indicate that employees in the Silver Worker age are much more inclined to leave their job for early retirement if they have to entirely work in the office.

Keywords: home office, remote work instead of early or partial retirement, silver worker, structural equation modeling

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Authors: Pradeepa Teegala, Ramreddy Chetteti

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

Keywords: chemical reaction, convective boundary condition, joule heating, micropolar fluid, spectral quasilinearization method

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Authors: Khoa Tan Nguyen, Tuan Anh Le, Kihak Lee

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This paper presents the flexural response of Reinforced Geopolymer Concrete (RGPC) beams. A commercial finite element (FE) software ABAQUS has been used to perform a structural behavior of RGPC beams. Using parameters such: stress, strain, Young’s modulus, and Poisson’s ratio obtained from experimental results, a beam model has been simulated in ABAQUS. The results from experimental tests and ABAQUS simulation were compared. Due to friction forces at the supports and loading rollers; slip occurring, the actual deflection of RGPC beam from experimental test results were slightly different from the results of ABAQUS. And there is good agreement between the crack patterns of fly ash-based geopolymer concrete generated by FE analysis using ABAQUS, and those in experimental data.

Keywords: geopolymer concrete beam, finite element mehod, stress strain relation, modulus elasticity

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Authors: Sikiru F. Oritola, Abd Latif Saleh, Abd Rahman Mohd Sam, Rozana Zakaria, Mushairry Mustaffar

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The strength of concrete varies with the types of material used; the material used within concrete can also result in different strength due to improper selection of the component. Each material brings a different aspect to the concrete. This work studied the effect of using Iron ore Tailings (IOTs) as partial replacement for sand on some properties of concrete using Fly ash Cement as the binder. The sieve analysis and some other basic properties of the materials used in producing concrete samples were first determined. Two brands of Fly ash Cement were studied. For each brand of Fly ash Cement, five different types of concrete samples denoted as HCT0, HCT10, HCT20, HCT30 and HCT40, for the first brand and PCT0, PCT10, PCT20, PCT30 and PCT40, for the second brand were produced. The percentage of Tailings as partial replacement for sand in the sample was varied from 0% to 40% at 10% interval. For each concrete sample, the average of three cubes, three cylinders and three prism specimen results was used for the determination of the compressive strength, splitting tensile strength and the flexural strength respectively. Water/cement ratio of 0.54 with fly-ash cement content of 463 Kg/m3 was used in preparing the fresh concrete. The slump values for the HCT brand concrete ranges from 152mm – 75mm while that of PCT brand ranges from 149mm to 70mm. The concrete sample PCT30 recorded the highest 28 days compressive strength of 28.12 N/mm2, the highest splitting tensile strength of 2.99 N/mm2 as well as the highest flexural strength of 4.99 N/mm2. The texture of the iron-ore tailings is rough and angular and was therefore able to improve the strength of the fly ash cement concrete. Also, due to the fineness of the IOTs more void in the concrete can be filled, but this reaches the optimum at 30% replacement level, hence the drop in strength at 40% replacement

Keywords: concrete strength, fine aggregate, fly ash cement, iron ore tailings

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Authors: Abbas Vahedian, Rijun Shrestha, Keith Crews

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The bond mechanism between timber and fibre reinforced polymer (FRP) is relatively complex and is influenced by a number of variables including bond thickness, bond width, bond length, material properties, and geometries. This study investigates the influence of bond thickness on the behaviour of interface, failure mode, and bond strength of externally bonded FRP-to-timber interface. In the present study, 106 single shear joint specimens have been investigated. Experiment results showed that higher layers of FRP increase the ultimate load carrying capacity of interface; conversely, such increase led to decrease the slip of interface. Moreover, samples with more layers of FRPs may fail in a brittle manner without noticeable warning that collapse is imminent.

Keywords: fibre reinforced polymer, FRP, single shear test, bond thickness, bond strength

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Authors: Marian Sagat, Mariana Remesikova

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In civil engineering, there is a problem how to industrially produce tensile membrane structures that are non-developable surfaces. Nondevelopable surfaces can only be developed with a certain error and we want to minimize this error. To that goal, the non-developable surfaces are cut into plates along to the geodesic curves. We propose a numerical algorithm for finding approximations of open geodesics on meshes and surfaces based on geodesic curvature flow. For practical reasons, it is important to automatize the choice of the time step. We propose a method for automatic setting of the time step based on the diagonal dominance criterion for the matrix of the linear system obtained by discretization of our partial differential equation model. Practical experiments show reliability of this method. Because approximation of the model is made by numerical method based on classic derivatives, it is necessary to solve obstacles which occur for meshes with sharp corners. We solve this problem for big family of meshes with sharp corners via special rotations which can be seen as partial unfolding of the mesh. In practical applications, it is required that the approximation of geodesic has its vertices only on the edges of the mesh. This problem is solved by a specially designed pointing tracking algorithm. We also partially solve the problem of finding geodesics on meshes with holes. We implemented the whole algorithm in Rhinoceros (commercial 3D computer graphics and computer-aided design software ). It is done by using C# language as C# assembly library for Grasshopper, which is plugin in Rhinoceros.

Keywords: geodesic, geodesic curvature flow, mesh, Rhinoceros software

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Authors: Frantisek Odvarka

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Based on the data from the Moravian Karst, the influence of the calcite speleothem growth by selected meteorological factors was evaluated. External temperature was determined as one of the main factors influencing speleothem growth in Moravian Karst. This factor significantly influences the CO₂ concentration in soil/epikarst, and cave atmosphere in the Moravian Karst and significantly contributes to the changes in the CO₂ partial pressure differences between soil/epikarst and cave atmosphere in Moravian Karst, which determines the drip water supersaturation with respect to the calcite and quantity of precipitated calcite in the Moravian Karst cave environment. External air temperatures and cave air temperatures were measured using a COMET S3120 data logger, which can measure temperatures in the range from -30 to +80 °C with an accuracy of ± 0.4 °C. CO₂ concentrations in the cave and soils were measured with a FT A600 CO₂H Ahlborn probe (value range 0 ppmv to 10,000 ppmv, accuracy 1 ppmv), which was connected to the data logger ALMEMO 2290-4, V5 Ahlborn. The soil temperature was measured with a FHA646E1 Ahlborn probe (temperature range -20 to 70 °C, accuracy ± 0.4 °C) connected to an ALMEMO 2290-4 V5 Ahlborn data logger. The airflow velocities into and out of the cave were monitored by a FVA395 TH4 Thermo anemometer (speed range from 0.05 to 2 m s⁻¹, accuracy ± 0.04 m s⁻¹), which was connected to the ALMEMO 2590-4 V5 Ahlborn data logger for recording. The flow was measured in the lower and upper entrance of the Imperial Cave. The data were analyzed in MS Office Excel 2019 and PHREEQC.

Keywords: speleothem growth, carbon dioxide partial pressure, Moravian Karst, external temperature

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Authors: Vijaya Pradhan, S. M. Deshpande, D. G. Regulwar

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Intense hydrogeological research has been prompted by the rising groundwater demand in typical hard rock terrain. In the current study, groundwater resources for irrigation in the canal command of the Jayakwadi Reservoir in the Indian state of Maharashtra are located using Vertical Electrical Soundings (VES). A Computer Resistivity Monitor is used to monitor the geoelectric field (CRM). Using Schlumberger setups, the investigation was carried out at seven different places in the region. Plotting of the sounding curves is the outcome of the data processing. The underlying layers and groundwater potential in the research region have been examined by analyzing these curves using curve-matching techniques, also known as partial curve matching. IPIWin2 is used to examine the relationship between resistivity and electrode spacing. The resistivity value in a geological formation is significantly reduced when groundwater is present. Up to a depth of 35 meters, the resistivity readings are minimal; beyond that, they continuously increase, suggesting a lack of water in deeper strata. As a result, the wells may only receive water up to a depth of 35 meters. In addition, the trap may occasionally fracture at deeper depths, retaining a limited amount of water in the cracks and producing a low yield. According to the findings, weathered basalt or soil make up the top layer (5–10 m), which is followed by a layer of amygdaloidal basalt (10–35 m) that is somewhat cracked and either hard basalt or compact basalt underneath.

Keywords: vertical electrical soundings (VES), resistivity, electrode spacing, Schlumberger configurations, partial curve matching.

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Authors: Rabah Haoui

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Hypersonic flows around spatial vehicles during their reentry phase in planetary atmospheres are characterized by intense aerothermodynamics phenomena. The aim of this work is to analyze high temperature flows around an axisymmetric blunt body taking into account chemical and vibrational non-equilibrium for air mixture species and the no slip condition at the wall. For this purpose, the Navier-Stokes equations system is resolved by the finite volume methodology to determine the flow parameters around the axisymmetric blunt body especially at the stagnation point and in the boundary layer along the wall of the blunt body. The code allows the capture of shock wave before a blunt body placed in hypersonic free stream. The numerical technique uses the Flux Vector Splitting method of Van Leer. CFL coefficient and mesh size level are selected to ensure the numerical convergence.

Keywords: hypersonic flow, viscous flow, chemical kinetic, dissociation, finite volumes, frozen and non-equilibrium flow

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Authors: Ahmad Fahim Nasiry, Shigeo Honma

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We examine two-dimensional oil displacement by water in a petroleum reservoir. The pore fluid is immiscible, and the porous media is homogenous and isotropic in the horizontal direction. Buckley-Leverett theory and a combination of Laplacian and Darcy’s law are used to study the fluid flow through porous media, and the Laplacian that defines the dispersion and diffusion of fluid in the sand using heavy oil is discussed. The reservoir is homogenous in the horizontal direction, as expressed by the partial differential equation. Two main factors which are observed are the water saturation and pressure distribution in the reservoir, and they are evaluated for predicting oil recovery in two dimensions by a physical and mathematical simulation model. We review the numerical simulation that solves difficult partial differential reservoir equations. Based on the numerical simulations, the saturation and pressure equations are calculated by the iterative alternating direction implicit method and the iterative alternating direction explicit method, respectively, according to the finite difference assumption. However, to understand the displacement of oil by water and the amount of water dispersion in the reservoir better, an interpolated contour line of the water distribution of the five-spot pattern, that provides an approximate solution which agrees well with the experimental results, is also presented. Finally, a computer program is developed to calculate the equation for pressure and water saturation and to draw the pressure contour line and water distribution contour line for the reservoir.

Keywords: numerical simulation, immiscible, finite difference, IADI, IDE, waterflooding

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Authors: Omid Allan

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The advent of ultra-narrow diameter implants initially offered an alternative to wider conventional implants. However, their design limitations have restricted their applicability primarily to overdentures and cement-retained fixed prostheses, often with unpredictable long-term outcomes. The introduction of the new Miniature Implants has revolutionized the field of implant dentistry, leading to a more streamlined approach. The utilization of Miniature Implants has emerged as a promising alternative to the traditional approach that entails the traumatic sequential bone drilling procedures and the use of conventional implants for full and partial arch restorations. The innovative "BioMiniatures Implant System serves as a groundbreaking bridge connecting mini implants with standard implant systems. This system allows practitioners to harness the advantages of ultra-small implants, enabling minimally invasive insertion and facilitating the application of fixed screw-retained prostheses, which were only available to conventional wider implant systems. This approach streamlines full and partial arch rehabilitation with minimal or even no bone drilling, significantly reducing surgical risks and complications for clinicians while minimizing patient morbidity. The ultra-narrow diameter and self-advancing features of these implants eliminate the need for invasive and technically complex procedures such as bone augmentation and guided bone regeneration (GBR), particularly in cases involving thin alveolar ridges. Furthermore, the absence of a microcap between the implant and abutment eliminates the potential for micro-leakage and micro-pumping effects, effectively mitigating the risk of marginal bone loss and future peri-implantitis. The cumulative experience of restoring over 50 full and partial arch edentulous cases with this system has yielded an outstanding success rate exceeding 97%. The long-term success with a stable marginal bone level in the study firmly establishes these implants as a dependable alternative to conventional implants, especially for full arch rehabilitation cases. Full arch rehabilitation with these implants holds the promise of providing a simplified solution for edentulous patients who typically present with atrophic narrow alveolar ridges, eliminating the need for extensive GBR and bone augmentation to restore their dentition with fixed prostheses.

Keywords: mini-implant, biominiatures, miniature implants, minimally invasive dentistry, full arch rehabilitation

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Authors: Ali Shubbar, Hassnen M. Jafer, Anmar Dulaimi, William Atherton, Ali Al-Rifaie

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This research represents experimental work for investigation of the influence of utilising Ground Granulated Blast Furnace Slag (GGBS) and High Calcium Fly Ash (HCFA) as a partial replacement for Ordinary Portland Cement (OPC) and produce a low carbon cementitious material with comparable compressive strength to OPC. Firstly, GGBS was used as a partial replacement to OPC to produce a binary blended cementitious material (BBCM); the replacements were 0, 10, 15, 20, 25, 30, 35, 40, 45 and 50% by the dry mass of OPC. The optimum BBCM was mixed with HCFA to produce a ternary blended cementitious material (TBCM). The replacements were 0, 10, 15, 20, 25, 30, 35, 40, 45 and 50% by the dry mass of BBCM. The compressive strength at ages of 7 and 28 days was utilised for assessing the performance of the test specimens in comparison to the reference mixture using 100% OPC as a binder. The results showed that the optimum BBCM was the mix produced from 25% GGBS and 75% OPC with compressive strength of 32.2 MPa at the age of 28 days. In addition, the results of the TBCM have shown that the addition of 10, 15, 20 and 25% of HCFA to the optimum BBCM improved the compressive strength by 22.7, 11.3, 5.2 and 2.1% respectively at 28 days. However, the replacement of optimum BBCM with more than 25% HCFA have showed a gradual drop in the compressive strength in comparison to the control mix. TBCM with 25% HCFA was considered to be the optimum as it showed better compressive strength than the control mix and at the same time reduced the amount of cement to 56%. Reducing the cement content to 56% will contribute to decrease the cost of construction materials, provide better compressive strength and also reduce the CO₂ emissions into the atmosphere.

Keywords: cementitious material, compressive strength, GGBS, HCFA, OPC

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Authors: Efil Yusrianto, Noraini Marsi, Noraniah Kassim, Izzati Abdul Manaf, Hafizuddin Hakim Shariff

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Today, municipal solid waste (MSW), noise pollution, and attack fire are three ongoing issues for inhabitants of urban including in Malaysia. To solve these issues, eco-friendly autoclaved aerated concrete (AAC) containing recycled ceramic and gypsum waste (CGW) as a partial replacement for sand with different ratios (0%, 5%, 10%, 15%, 20%, and 25% wt) has been prepared. The performance of samples, such as the physical, mechanical, sound absorption coefficient, and direct fire resistance, has been investigated. All samples showed normal color behavior, i.e., grey and free crack. The compressive strength was increased in the range of 6.10% to 29.88%. The maximum value of compressive strength was 2.13MPa for 15% wt of CGW. The positive effect of CGW on the compressive strength of AAC has also been confirmed by crystalline phase and microstructure analysis. The acoustic performances, such as sound absorption coefficients of samples at low frequencies (500Hz), are higher than the reference sample (RS). AAC-CGW samples are categorized as AAC material classes B and C. The fire resistance results showed the physical surface of the samples had a free crack and was not burned during the direct fire at 950ºC for 300s. The results showed that CGW succeeded in enhancing the performance of fresh AAC, such as compressive strength, crystalline phase, sound absorption coefficient, and fire resistance of samples.

Keywords: physical, mechanical, acoustic, direct fire resistance performance, autoclaved aerated concrete, recycled ceramic-gypsum waste

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Authors: Bohuslava Juhasova, Igor Halenar, Martin Juhas

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The wireless communication is one of the widely used methods of data transfer at the present days. The benefit of this communication method is the partial independence of the infrastructure and the possibility of mobility. In some special applications it is the only way how to connect. This paper presents some problems in the implementation of a sensor network connection for measuring environmental parameters in the area of manufacturing plants.

Keywords: network, communication, reliability, sensors

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Authors: Shin-Pin Tseng

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Nowadays, numerous spectral amplitude coding (SAC) fiber-optic code-division-multiple-access (FO-CDMA) techniques were appealing due to their capable of providing moderate security and relieving the effects of multiuser interference (MUI). Nonetheless, the performance of the previous network is degraded due to fixed in-phase cross-correlation (IPCC) value. Based on the above problems, a new SAC FO-CDMA network using partial M-sequence (PMS) code is presented in this study. Because the proposed PMS code is originated from M-sequence code, the system using the PMS code could effectively suppress the effects of MUI. In addition, two-code keying (TCK) scheme can applied in the proposed SAC FO-CDMA network and enhance the whole network performance. According to the consideration of system flexibility, simple optical encoders/decoders (codecs) using fiber Bragg gratings (FBGs) were also developed. First, we constructed a diagram of the SAC FO-CDMA network, including (N/2-1) optical transmitters, (N/2-1) optical receivers, and one N×N star coupler for broadcasting transmitted optical signals to arrive at the input port of each optical receiver. Note that the parameter N for the PMS code was the code length. In addition, the proposed SAC network was using superluminescent diodes (SLDs) as light sources, which then can save a lot of system cost compared with the other FO-CDMA methods. For the design of each optical transmitter, it is composed of an SLD, one optical switch, and two optical encoders according to assigned PMS codewords. On the other hand, each optical receivers includes a 1 × 2 splitter, two optical decoders, and one balanced photodiode for mitigating the effect of MUI. In order to simplify the next analysis, the some assumptions were used. First, the unipolarized SLD has flat power spectral density (PSD). Second, the received optical power at the input port of each optical receiver is the same. Third, all photodiodes in the proposed network have the same electrical properties. Fourth, transmitting '1' and '0' has an equal probability. Subsequently, by taking the factors of phase‐induced intensity noise (PIIN) and thermal noise, the corresponding performance was displayed and compared with the performance of the previous SAC FO-CDMA networks. From the numerical result, it shows that the proposed network improved about 25% performance than that using other codes at BER=10-9. This is because the effect of PIIN was effectively mitigated and the received power was enhanced by two times. As a result, the SAC FO-CDMA network using PMS codes has an opportunity to apply in applications of the next-generation optical network.

Keywords: spectral amplitude coding, SAC, fiber-optic code-division multiple-access, FO-CDMA, partial M-sequence, PMS code, fiber Bragg grating, FBG

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Authors: Khalid El Asri

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Culture influences lexicalization of salient concepts in a society. Hence, languages often have different degrees of equivalence regarding lexical items of different fields. The present study focuses on the field of emotions in English and Moroccan Arabic. Findings of a comparative study that involved fifty English emotions revealed that Moroccan Arabic has equivalence of some English emotion terms, partial equivalence of some emotion terms, and no equivalence for some other terms. It is hypothesized then that emotion terms that have near equivalence in Moroccan Arabic will be easier to acquire for EFL learners, while partially equivalent terms will be difficult to acquire, and those that have no equivalence will be even more difficult to acquire. In order to test these hypotheses, the participants (104 advanced Moroccan EFL learners and 104 native speakers of English) were given two tests: the first is a receptive one in which the participants were asked to choose, among four emotion terms, the term that is appropriate to fill in the blanks for a given situation indicating certain kind of feelings. The second test is a productive one in which the participants were asked to give the emotion term that best described the feelings of the people in the situations given. The results showed that conceptually equivalent terms do not pose any problems for Moroccan EFL learners since they can link the concept to an already existing linguistic category; whereas the results concerning the acquisition of partially equivalent terms indicated that this type of emotion terms were difficult for Moroccan EFL learners to acquire, because they need to restructure the boundaries of the target linguistic categories by expanding them when the term includes other range of meanings that are not subsumed in the L1 term. Surprisingly however, the results concerning the case of non-equivalence revealed that Moroccan EFL learners could internalize the target L2 concepts that have no equivalence in their L1. Thus, it is the category of emotion terms that have partial equivalence in the learners’ L1 that pose problems for them.

Keywords: acquisition, culture, emotion terms, lexical equivalence

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Authors: Ng Wei Yan, Lim Jee Hock, Lee Foo Wei, Mo Kim Hung, Yip Chun Chieh

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The burgeoning accumulation of glass waste in Malaysia, particularly from the food and beverage industry, has become a prominent environmental concern, with disposal sites reaching saturation. This study introduces a distinct approach to addressing the twin challenges of landfill scarcity and natural resource conservation by repurposing discarded glass bottle waste into a viable construction material. The research presents a comprehensive evaluation of the strength characteristics of cement mortar when dark glass waste powder is used as a partial sand replacement. The experimental investigation probes the density, flow spread diameter, and key strength parameters—including compressive, splitting tensile, and flexural strengths—of the modified cement mortar. Remarkably, results indicate that a full replacement of sand with glass waste powder significantly improves the material's strength attributes. A specific mixture with a cement/sand/water ratio of 1:5:1.24 was found to be optimal, yielding an impressive compressive strength of 7 MPa at the 28-day mark, accompanied by a favourable 200 mm spread diameter in flow table tests. The findings of this study underscore the dual benefits of utilizing glass waste powder in cement mortar: mitigating Malaysia's glass waste dilemma and enhancing the performance of construction materials such as bricks and concrete products. Consequently, the research validates the premise that increasing the incorporation of glass waste as a sand substitute promotes not only environmental sustainability but also material innovation in the construction industry.

Keywords: glass waste, strength properties, cement mortar, environmental friendly

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Authors: Yaya Gao, Bing Zhong, Yafeng Liu, Fei Chen

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Aim: The purpose of this study was to explore the difference between acellular dermal matrix (ADM) combined with anterolateral thigh (ALT) flap and ALT flap alone. Methods: HSCC patients were treated and divided into group A (ALT) and group B (ALT+ADM) between January 2014 and December 2018. We compared and analyzed the intraoperative information and postoperative outcomes of the patients. Results: There were 21 and 17 patients in group A and group B, respectively. The operation time, blood loss, defect size and anastomotic vessel selection showed no significant difference between two groups. The postoperative complications, including wound bleeding (n=0 vs. 1, p=0.459), wound dehiscence (n=0 vs. 1, p=0.459), wound infection (n=5vs.3, p=0.709), pharyngeal fistula (n=5vs.4, p=1.000) and hypoproteinemia (n=11 vs. 12, p=0.326) were comparable between the groups. Dysphagia at 6 months (number of liquid diets=0vs. 0; number of partial tube feedings=1vs. 1; number of total tube feedings=1vs. 0, p=0.655) also showed no significant differences. However, significant differences was observed in dysphagia at 12 months (number of liquid diets=0vs. 0; number of partial tube feedings=3 vs. 1; number of total tube feedings=10vs. 1, p=0.006). Conclusion: For HSCC patients, the use of the ALT flap combined ADM, compared to ALT treatment, showed better swallowing function at 12 months. The ALT flap combined ADM may serve as a safe and feasible alternative for selected HSCC patients.

Keywords: hypopharyngeal squamous cell carcinoma, anterolateral thigh free flap, acellular dermal matrix, reconstruction, dysphagia

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Authors: Zerarka Hizia, Akchiche Mustapha, Prunier Florent

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The landslide of Ain El Hammam (AEH) is characterized by a complex geology and a high hydrogeology hazard. AEH's perpetual reactivation compels us to look closely at its triggers and to better understand the mechanisms of its evolution in mass and in depth. This study builds a numerical model to simulate the influencing factors such as precipitation, non-saturation, and pore pressure fluctuations, using Plaxis software. For a finer analysis of instabilities, we use Hill's criterion, based on the sign of the second order work, which is the most appropriate material stability criterion for non-associated elastoplastic materials. The results of this type of calculation allow us, in theory, to predict the shape and position of the slip surface(s) which are liable to ground movements of the slope, before reaching the rupture given by the plastic limit of Mohr Coulomb. To validate the numerical model, an analysis of inclinometer measures is performed to confirm the direction of movement and kinematic of the sliding mechanism of AEH’s slope.

Keywords: landslide, second order work, precipitation, inclinometers

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Authors: Rolando B. Llave Jr.

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In many countries, wheat flour is used an essential component in production/preparation of bread and other baked products considered to have a significant role in man’s diet. Partial replacement of wheat flour with other flours (composite flour) in preparation of the said products is seen as a solution to the scarcity of wheat flour (in non-wheat producing countries), and improved nourishment. In composite flour, other flours may come from cereals, legumes, root crops, and those that are rich in starch. Many countries utilize whatever is locally available. “Adlai” or Job’s tears is a tall cereal plant that belongs to the same family of grass as wheat, rice, and corn. In some countries, it is used as an ingredient in producing many dishes and alcoholic and non-alcoholic beverages. As part of the Food Staple Self-Sufficiency Program (FSSP) of the Department of Agriculture (DA) in the Philippines, “adlai” is being promoted as alternative food source for the Filipinos. In this study, the grits coming from the seeds of “adlai” were turned into flour. The resulting flour was then used as partial replacement for wheat flour in selected baked products namely “pan de sal” (salt bread), cupcakes and cookies. The supplementation of “adlai” flour ranged 20%-45% with 20%-35% for “pan de sal”; 30%-45% for cupcakes; and 25% - 40% for cookies. The study was composed of four (4) phases. Phase I was product formulation studies. Phase II included the acceptability test/sensory evaluation of the baked products where the statistical analysis of the data gathered followed. Phase III was the computation of the theoretical protein content of the most acceptable “pan de sal”, cupcake and cookie, and lastly, in Phase IV, cost benefit was analyzed, specifically in terms of the direct material cost.

Keywords: “adlai”, composite flour, supplementation, sensory evaluation

Procedia PDF Downloads 869

Authors: Anwar H. Radwan, Jan Mrlina, El-Sayed A. Issawy, Ali Rayan, Salah M. Mahmoud

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Geodynamic investigations in the Aswan Lake region were started after the M=5.5 earthquake in 1981, triggered by the lake water fluctuations. Besides establishing the seismological networks, also the geodetic observations focused on the Kalabsha and Sayal fault zones were started. It was found that the Kalabsha fault is an active dextral strike-slip with normal component indicating uplift on its southern side. However, the annual velocity rates in both components do not exceed 2 mm/y, and do not therefore represent extremely active faulting. We also launched gravity monitoring in 1997, and performed another two campaigns in 2000 and 2002. The observed non- tidal temporal gravity changes indicate rather the flood water infiltration into the porous Nubian sandstone, than tectonic stress effect. The station nearest to the lake exhibited about 60 μGal positive gravity change within the 1997-2002 period.

Keywords: gravity monitoring, surface movements, Lake Aswan, groundwater change

Procedia PDF Downloads 504

Authors: Mequanent Wale Mekonen, Edoardo Otranto, Angela Alibrandi

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Diabetic kidney disease is one of the main microvascular complications caused by diabetes. Several clinical and biochemical variables are reported to be associated with diabetic kidney disease in people with type 2 diabetes. However, their interrelations could distort the effect estimation of these variables for the disease's progression. The objective of the study is to determine how the biochemical and clinical variables in people with type 2 diabetes are interrelated with each other and their effects on kidney disease progression through advanced statistical methods. First, principal component analysis was used to explore how the biochemical and clinical variables intercorrelate with each other, which helped us reduce a set of correlated biochemical variables to a smaller number of uncorrelated variables. Then, ordered logit regression models (cumulative, stage, and adjacent) were employed to assess the effect of biochemical and clinical variables on the order-level response variable (progression of kidney function) by considering the proportionality assumption for more robust effect estimation. This retrospective cross-sectional study retrieved data from a type 2 diabetic cohort in a polyclinic hospital at the University of Messina, Italy. The principal component analysis yielded three uncorrelated components. These are principal component 1, with negative loading of glycosylated haemoglobin, glycemia, and creatinine; principal component 2, with negative loading of total cholesterol and low-density lipoprotein; and principal component 3, with negative loading of high-density lipoprotein and a positive load of triglycerides. The ordered logit models (cumulative, stage, and adjacent) showed that the first component (glycosylated haemoglobin, glycemia, and creatinine) had a significant effect on the progression of kidney disease. For instance, the cumulative odds model indicated that the first principal component (linear combination of glycosylated haemoglobin, glycemia, and creatinine) had a strong and significant effect on the progression of kidney disease, with an effect or odds ratio of 0.423 (P value = 0.000). However, this effect was inconsistent across levels of kidney disease because the first principal component did not meet the proportionality assumption. To address the proportionality problem and provide robust effect estimates, alternative ordered logit models, such as the partial cumulative odds model, the partial adjacent category model, and the partial continuation ratio model, were used. These models suggested that clinical variables such as age, sex, body mass index, medication (metformin), and biochemical variables such as glycosylated haemoglobin, glycemia, and creatinine have a significant effect on the progression of kidney disease.

Keywords: diabetic kidney disease, ordered logit model, principal component analysis, type 2 diabetes

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Authors: Zhibin Lei, Minghui Yang

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Ningwu-Jingle basin is a structural syncline which has undergone a complex tectono-thermal history since Cretaceous. It stretches along the strike of the northern Lvliang Mountains which are the most important mountains in the middle and west of North China Craton. The Mesozoic units make up of the core of Ningwu-Jingle Basin, with pre-Mesozoic units making up of its flanks. The available low-temperature thermochronology implies that Ningwu-Jingle Basin has experienced two stages of uplifting: 94±7Ma to 111±8Ma (Albian to Cenomanian) and 62±4 to 75±5Ma (Danian to Maastrichtian). In order to constrain its tectono-thermal history in the Cenozoic, both apatite (U-Th-Sm)/He and fission track dating analysis are applied on 3 Middle Jurassic and 3 Upper Triassic sandstone samples. The central fission track ages range from 74.4±8.8Ma to 66.0±8.0Ma (Campanian to Maastrichtian) which matches well with previous data. The central He ages range from 20.1±1.2Ma to 49.1±3.0Ma (Ypresian to Burdigalian). Inverse thermal modeling is established based on both apatite fission track data and (U-Th-Sm)/He data. The thermal history obtained reveals that all 6 sandstone samples cross the high-temperature limit of fission track partial annealing zone by the uppermost Cretaceous and that of He partial retention zone by the uppermost Eocene to the early Oligocene. The result indicates that the middle and west of North China Craton is not stable in the Cenozoic.

Keywords: apatite fission track thermochronology, apatite (u–th)/he thermochronology, Ningwu-Jingle basin, North China craton, tectono-thermal history

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Authors: Satya Deo, Deepak Kumar Maurya

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The present study investigates the ow of a Newtonian fluid sandwiched between two rectangular porous channels filled with micropolar fluid in the presence of a uniform magnetic field applied in a direction perpendicular to that of the fluid motion. The governing equations of micropolar fluid are modified by Nowacki's approach. For respective porous channels, expressions for velocity vectors, microrotations, stresses (shear and couple) are obtained analytically. Continuity of velocities, continuities of micro rotations and continuity of stresses are used at the porous interfaces; conditions of no-slip and no spin are applied at the impervious boundaries of the composite channel. Numerical values of flow rate, wall shear stresses and couple stresses at the porous interfaces are calculated for different values of various parameters. Graphs of the ow rate and fluid velocity are plotted and their behaviors are discussed.

Keywords: couple stress, flow rate, Hartmann number, micropolar fluids

Procedia PDF Downloads 242