Search results for: momentum ratio
4599 Investigate the Mechanical Effect of Different Root Analogue Models to Soil Strength
Authors: Asmaa Al Shafiee, Erdin Ibraim
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Stabilizing slopes by using vegetation is considered as a cost-effective and eco-friendly alternative to the conventional methods. The main aim of this study is to investigate the mechanical effect of analogue root systems on the shear strength of different soil types. Three objectives were defined to achieve the main aim of this paper. Firstly, explore the effect of root architectural design to shear strength parameters. Secondly, study the effect of root area ratio (RAR) on the shear strength of two different soil types. Finally, to investigate how different kinds of soil can affect the behavior of the roots during shear failure. 3D printing tool was used to develop different analogue tap root models with different architectural designs. Direct shear tests were performed on Leighton Buzzard (LB) fraction B sand, which represents a coarse sand and Huston sand, which represent medium-coarse sand. All tests were done with the same relative density for both kinds of sand. The results of the direct shear test indicated that using plant roots will increase both friction angle and cohesion of soil. Additionally, different root designs affected differently the shear strength of the soil. Furthermore, the directly proportional relationship was found between root area ratio for the same root design and shear strength parameters of soil. Finally, the root area ratio effect should be combined with branches penetrating the shear plane to get the highest results.Keywords: leighton buzzard sand, root area ratio, rooted soil, shear strength, slope stabilization
Procedia PDF Downloads 1524598 Based on MR Spectroscopy, Metabolite Ratio Analysis of MRI Images for Metastatic Lesion
Authors: Hossain A, Hossain S.
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Introduction: In a small cohort, we sought to assess the magnetic resonance spectroscopy's (MRS) ability to predict the presence of metastatic lesions. Method: A Popular Diagnostic Centre Limited enrolled patients with neuroepithelial tumors. The 1H CSI MRS of the brain allows us to detect changes in the concentration of specific metabolites caused by metastatic lesions. Among these metabolites are N-acetyl-aspartate (NNA), creatine (Cr), and choline (Cho). For Cho, NAA, Cr, and Cr₂, the metabolic ratio was calculated using the division method. Results: The NAA values were 0.63 and 5.65 for tumor cells, 1.86 and 5.66 for normal cells, and 1.86 and 5.66 for normal cells 2. NAA values for normal cells 1 were 1.84, 10.6, and 1.86 for normal cells 2, respectively. Cho levels were as low as 0.8 and 10.53 in the tumor cell, compared to 1.12 and 2.7 in the normal cell 1 and 1.24 and 6.36 in the normal cell 2. Cho/Cr₂ barely distinguished itself from the other ratios in terms of significance. For tumor cells, the ratios of Cho/NAA, Cho/Cr₂, NAA/Cho, and NAA/Cr₂ were significant. Normal cell 1 had significant Cho/NAA, Cho/Cr, NAA/Cho, and NAA/Cr ratios. Conclusion: The clinical result can be improved by using 1H-MRSI to guide the size of resection for metastatic lesions. Even though it is non-invasive and doesn't present any difficulties during the procedure, MRS has been shown to predict the detection of metastatic lesions.Keywords: metabolite ratio, MRI images, metastatic lesion, MR spectroscopy, N-acetyl-aspartate
Procedia PDF Downloads 964597 Simultaneous Esterification and Transesterification of High FFA Jatropha Oil Using Reactive Distillation for Biodiesel Production
Authors: Ratna Dewi Kusumaningtyas, Prima Astuti Handayani, Arief Budiman
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Reactive Distillation (RD) is a multifunctional reactor which integrates chemical reaction with in situ separation to shift the equilibrium towards the product formation. Thus, it is suitable for equilibrium limited reaction such as esterification and transesterification to enhance the reaction conversion. In this work, the application of RD for high FFA oil esterification-transterification for biodiesel production using sulphuric acid catalyst has been studied. Crude Jatropha Oil with FFA content of 30.57% was utilized as the feedstock. Effects of the catalyst concentration and molar ratio of the alcohol to oils were also investigated. It was revealed that best result was obtained with sulphuric acid catalyst (reaction conversion of 94.71% and FFA content of 1.62%) at 60C, molar ratio of methanol to FFA of 30:1, and catalyst loading of 3%. After undergoing esterification reaction, jatropha oil was then transesterified to produce biodiesel. Transesterification reaction was performed in the presence of NaOH catalyst in RD column at 60C, molar ratio of methanol to oil of 6:1, and catalyst concentration of 1%. It demonstrated that biodiesel produced in this work agreed with the Indonesian National and ASTM standard of fuel.Keywords: reactive distillation, biodiesel, esterification, transesterification
Procedia PDF Downloads 4604596 Comparison of Accumulated Stress Based Pore Pressure Model and Plasticity Model in 1D Site Response Analysis
Authors: Saeedullah J. Mandokhail, Shamsher Sadiq, Meer H. Khan
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This paper presents the comparison of excess pore water pressure ratio (ru) predicted by using accumulated stress based pore pressure model and plasticity model. One dimensional effective stress site response analyses were performed on a 30 m deep sand column (consists of a liquefiable layer in between non-liquefiable layers) using accumulated stress based pore pressure model in Deepsoil and PDMY2 (PressureDependentMultiYield02) model in Opensees. Three Input motions with different peak ground acceleration (PGA) levels of 0.357 g, 0.124 g, and 0.11 g were used in this study. The developed excess pore pressure ratio predicted by the above two models were compared and analyzed along the depth. The time history of the ru at mid of the liquefiable layer and non-liquefiable layer were also compared. The comparisons show that the two models predict mostly similar ru values. The predicted ru is also consistent with the PGA level of the input motions.Keywords: effective stress, excess pore pressure ratio, pore pressure model, site response analysis
Procedia PDF Downloads 2274595 Evaluation of the Operating Parameters for Biodiesel Production Using a Membrane Reactor
Authors: S. S. L. Andrade, E. A. Souza, L. C. L. Santos, C. Moraes, A. K. C. L. Lobato
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Biodiesel production using membrane reactor has become increasingly studied, because this process minimizes some of the main problems encountered in the biodiesel purification. The membrane reactor tries to minimize post-treatment steps, resulting in cost savings and enabling the competitiveness of biodiesel produced by homogeneous alkaline catalysis. This is due to the reaction and product separation may occur simultaneously. In order to evaluate the production of biodiesel from soybean oils using a tubular membrane reactor, a factorial experimental design was conducted (2³) to evaluate the influence of following variables: temperature (45 to 60 °C), catalyst concentration (0.5 to 1% by weight) and molar ratio of oil/methanol (1/6 to 1/9). In addition, the parametric sensitivity was evaluated by the analysis of variance and model through the response surface. The results showed a tendency of influence of the variables in the reaction conversion. The significance effect was higher for the catalyst concentration followed by the molar ratio of oil/methanol and finally the temperature. The best result was obtained under the conditions of 1% catalyst (KOH), molar ratio oil/methanol of 1/9 and temperature of 60 °C, resulting in an ester content of 99.07%.Keywords: biodiesel production, factorial design, membrane reactor, soybean oil
Procedia PDF Downloads 3774594 In Search of Commonalities in the Determinants of Child Sex Ratios in India and People's of Republic of China
Authors: Suddhasil Siddhanta, Debasish Nandy
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Child sex ratios pattern in the Asian Population is highly masculine mainly due to birth masculinity and gender bias in child mortality. The vast and the growing literature of female deficit in world population points out the diffusion of child sex ratio pattern in many Asian as well as neighboring European countries. However, little attention has been given to understand the common factors in different demographics in explaining child sex ratio pattern. Such a scholarship is extremely important as level of gender inequity is different in different country set up. Our paper tries to explain the major structural commonalities in the child masculinity pattern in two demographic billionaires - India and China. The analysis reveals that apart from geographical diffusion of sex selection technology, patrilocal social structure, as proxied by households with more than one generation in China and proportion of population aged 65 years and above in India, can explain significant variation of missing girl child in these two countries. Even after controlling for individual capacity building factors like educational attainment, or work force participation, the measure of social stratification is coming out to be the major determinant of child sex ratio variation. Other socio economic factors that perform much well are the agency building factors of the females, like changing pattern of marriage customs which is proxied by divorce and remarriage ratio for china and percentage of female marrying at or after the age of 20 years in India and the female workforce participation. Proportion of minorities in socio-religious composition of the population and gender bias in scholastic attainment in both these counties are also found to be significant in modeling child sex ratio variations. All these significant common factors associated with child sex ratio point toward the one single most important factor: the historical evolution of patriarchy and its contemporary perpetuation in both the countries. It seems that prohibition of sex selection might not be sufficient to combat the peculiar skewness of excessive maleness in child population in both these countries. Demand sided policies is therefore utmost important to root out the gender bias in child sex ratios.Keywords: child sex ratios, gender bias, structural factors, prosperity, patrilocality
Procedia PDF Downloads 1574593 Empirical Modeling of Air Dried Rubberwood Drying System
Authors: S. Khamtree, T. Ratanawilai, C. Nuntadusit
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Rubberwood is a crucial commercial timber in Southern Thailand. All processes in a rubberwood production depend on the knowledge and expertise of the technicians, especially the drying process. This research aims to develop an empirical model for drying kinetics in rubberwood. During the experiment, the temperature of the hot air and the average air flow velocity were kept at 80-100 °C and 1.75 m/s, respectively. The moisture content in the samples was determined less than 12% in the achievement of drying basis. The drying kinetic was simulated using an empirical solver. The experimental results illustrated that the moisture content was reduced whereas the drying temperature and time were increased. The coefficient of the moisture ratio between the empirical and the experimental model was tested with three statistical parameters, R-square (R²), Root Mean Square Error (RMSE) and Chi-square (χ²) to predict the accuracy of the parameters. The experimental moisture ratio had a good fit with the empirical model. Additionally, the results indicated that the drying of rubberwood using the Henderson and Pabis model revealed the suitable level of agreement. The result presented an excellent estimation (R² = 0.9963) for the moisture movement compared to the other models. Therefore, the empirical results were valid and can be implemented in the future experiments.Keywords: empirical models, rubberwood, moisture ratio, hot air drying
Procedia PDF Downloads 2674592 Nanowire by Ac Electrodeposition Into Nanoporous Alumina Fabrication of High Aspect Ratio Metalic
Authors: M. Beyzaiea, S. Mohammadia
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High aspect ratio metallic (silver, cobalt) nanowire arrays were fabricated using ac electrodeposition techniques into the nanoporous alumina template. The template with long pore dept fabricated by hard anodization (HA) and thinned for ac electrodeposition. Template preparation was done in short time by using HA technique and high speed thing process. The TEM and XRD investigation confirm the three dimensional nucleation growth mechanism of metallic nanowire inside the nanoporous alumina that fabricated by HA process.Keywords: metallic, nanowire, nanoporous alumina, ac electrodeposition
Procedia PDF Downloads 2724591 Characteristics Influencing Response of a Base Isolated Building
Authors: Ounis Hadj Mohamed, Ounis Abdelhafid
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In order to illustrate the effect of damping on the response of a base-isolated building, a parametric study is led, taking into account the progressive variation of the damping ratio (10% to 30%) under different types of seismic excitations (near and far field). A time history analysis is used to determine the response of the structure in terms of relative displacement and understory drift at various levels of the building. Thus, the results show that the efficiency of the isolator increases with the assumed damping ratio, provided that this latter is less or equal to 20%. Beyond this value, the isolator becomes less convenient. Furthermore, a strong deviation of energy capacity by the LRB (Lead Rubber Bearing) system is recorded.Keywords: damping, base isolation, LRB, seismic excitation, hysteresis
Procedia PDF Downloads 4154590 Factors Influencing Bank Profitability of Czech Banks and Their International Parent Companies
Authors: Libena Cernohorska
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The goal of this paper is to specify factors influencing the profitability of selected banks. Next, a model will be created to help establish variables that have a demonstrable influence on the development of the selected banks' profitability ratios. Czech banks and their international parent companies were selected for analyzing profitability. Banks categorized as large banks (according to the Czech National Bank's system, which ranks banks according to balance sheet total) were selected to represent the Czech banks. Two ratios, the return on assets ratio (ROA) and the return on equity ratio (ROE) are used to assess bank profitability. Six endogenous and four external indicators were selected from among other factors that influence bank profitability. The data analyzed were for the years 2001 – 2013. First, correlation analysis, which was supposed to eliminate correlated values, was conducted. A large number of correlated values were established on the basis of this analysis. The strongly correlated values were omitted. Despite this, the subsequent regression analysis of profitability for the individual banks that were selected did not confirm that the selected variables influenced their profitability. The studied factors' influence on bank profitability was demonstrated only for Československá Obchodní Banka and Société Générale using regression analysis. For Československá Obchodní Banka, it was demonstrated that inflation level and the amount of the central bank's interest rate influenced the return on assets ratio and that capital adequacy and market concentration influenced the return on equity ratio for Société Générale.Keywords: banks, profitability, regression analysis, ROA, ROE
Procedia PDF Downloads 2544589 Dependence of Ionomer Loading on the Hydrogen Generation Rate of a Proton Exchange Membrane Electrolyzer
Authors: Yingjeng James Li, Chih Chi Hsu, Chiao-Chih Hu
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Membrane electrode assemblies MEAs for proton exchange membrane PEM water electrolyzers were prepared by employing 175um perfluorosulfonic acid PFSA membranes as the PEM, onto which iridium oxide catalyst was coated on one side as the anode and platinum catalyst was coated on the other side as the cathode. The cathode catalyst ink was prepared so that the weight ratio of the catalyst powder to ionomer was 75:25, 70:30, 65:35, 60:40, and 55:45, respectively. Whereas, the ratio of catalyst powder to ionomer of the anode catalyst ink keeps constant at 50:50. All the MEAs have a catalyst coated area of 5cm*5cm. The test cell employs a platinum plated titanium grid as anode gas diffusion media; whereas, carbon paper was employed as the cathode gas diffusion media. The measurements of the MEA gases production rate were carried out by holding the cell voltage ranging from 1.6 to 2.8 volts at room temperature. It was found that the MEA with cathode catalyst to ionomer ratio of 65:35 gives the largest hydrogen production rate which is 2.8mL/cm2*min.Keywords: electrolyzer, membrane electrode assembly, proton exchange membrane, ionomer, hydrogen
Procedia PDF Downloads 2554588 Analysis of Financial Performance Measurement and Financial Distress Assessment of Highway Companies Listed on Indonesia Stock Exchange before and during COVID-19 Pandemic
Authors: Ari Prasetyo, Taufik Faturohman
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The COVID-19 pandemic in Indonesia is part of the ongoing worldwide pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It was confirmed to have spread to Indonesia on 2 March 2020. Moreover, the government of Indonesia has been conducting a local lockdown to limit people's movement from one city to another city. Therefore, this situation has impact on business operation, especially on highway companies listed on the Indonesia stock exchange. This study evaluates and measures three companies’ financial performance and health conditions before and during the COVID-19 pandemic from 2016 – 2020. The measurement is conducted by using financial ratio analysis and the Altman Z-score method. The ratio used to measure the financial ratio analysis is taken from the decree of the Ministry of SOE’s KEP-100/MBU/2002 about the company’s health level condition. From the decree, there are eight financial ratios used such as return on equity (ROE), return on investment (ROI), current ratio, cash ratio, collection period, inventory turnover, total asset turnover, and total equity to total asset. Altman Z-score is used to calculate the financial distress condition. The result shows that the highway companies for the period 2016 – 2020 are as follows: PT Jasa Marga (Persero) Tbk (AA, BB, BB, BB, C), PT Citra Marga Nusaphala Persada Tbk (BB, AA, BB, BBB, C), and PT Nusantara Infrastructure Tbk (BB, BB, AA, BBB, C). In addition, the Altman Z-score assessment performed in 2016-2020 shows that PT Jasa Marga (Persero) Tbk was in the grey zone area for 2015-2018 and in the distress zone for 2019-2020. PT Citra Marga Nusaphala Persada Tbk was in the grey zone area for 2015-2019 and in the distress zone for 2020. PT Nusantara Infrastructure Tbk was in the grey zone area for 2015-2018 and in the distress zone for 2019-2020.Keywords: financial performance, financial ratio, Altman Z-score, financial distress, highway company
Procedia PDF Downloads 1914587 Intensification of Ethyl Esters Synthesis Using a Packed-Bed Tubular Reactor at Supercritical Conditions
Authors: Camila da Silva, Simone Belorte de Andrade, Vitor Augusto dos Santos Garcia, Vladimir Ferreira Cabral, J. Vladimir Oliveira Lúcio Cardozo-Filho
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In the present study, the non-catalytic transesterification of soybean oil in continuous mode using supercritical ethanol were investigated. Experiments were performed in a packed-bed tubular reactor (PBTR) and variable studied were reaction temperature (523 K to 598 K), pressure (10 MPa to 20 MPa), oil to ethanol molar ratio (1:10 to 1:40) and water concentration (0 wt% to 10 wt% in ethanol). Results showed that ethyl esters yields obtained in the PBTR were higher (> 20 wt%) than those verified in a tubular reactor (TR), due to improved mass transfer conditions attained in the PBTR. Results demonstrated that temperature, pressure, oil to ethanol molar ratio and water concentration had a positive effect on fatty acid ethyl esters (FAEE) production in the experimental range investigated, with appreciable reaction yields (90 wt%) achieved at 598 K, 20 MPa, oil to ethanol molar ratio of 1:40 and 10 wt% of water concentration.Keywords: packed bed reactor, ethyl esters, continuous process, catalyst-free process
Procedia PDF Downloads 5254586 Design, Construction And Validation Of A Simple, Low-cost Phi Meter
Authors: Gabrielle Peck, Ryan Hayes
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The use of a phi meter allows for definition of equivalence ratio during a fire test. Previous phi meter designs have used expensive catalysts and had restricted portability due to the large furnace and requirement for pure oxygen. The new design of the phi meter did not require the use of a catalyst. The furnace design was based on the existing micro-scale combustion calorimetry (MCC) furnace and operating conditions based on the secondary oxidizer furnace used in the steady state tube furnace (SSTF). Preliminary tests were conducted to study the effects of varying furnace temperatures on combustion efficiency. The SSTF was chosen to validate the phi meter measurements as it can both pre-set and independently quantify the equivalence ratio during a test. The data were in agreement with the data obtained on the SSTF. It was also validated by a comparison of CO2 yields obtained from the SSTF oxidizer and those obtained by the phi meter. The phi meter designed and constructed in this work was proven to work effectively on a bench-scale. The phi meter was then used to measure the equivalence ratio on a series of large-scale ISO 9705 tests for numerous fire conditions. The materials used were a range of non-homogenous materials such as polyurethane. The measurements corresponded accurately to the data collected, showing the novel design can be used from bench to large-scale tests to measure equivalence ratio. This cheaper, more portable, safer and easier to use phi meter design will enable more widespread use and the ability to quantify fire conditions of tests, allowing for better understanding of flammability and smoke toxicity.Keywords: phi meter, smoke toxicity, fire condition, ISO9705, novel equipment
Procedia PDF Downloads 1034585 Influence of Wall Stiffness and Embedment Depth on Excavations Supported by Cantilever Walls
Authors: Muhammad Naseem Baig, Abdul Qudoos Khan, Jamal Ali
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Ground deformations in deep excavations are affected by wall stiffness and pile embedment ratio. This paper presents the findings of a parametric study of 64ft deep excavation in mixed stiff soil conditions supported by a cantilever pile wall. A series of finite element analyses have been carried out in Plaxis 2D by varying pile embedment ratio and wall stiffness. It has been observed that maximum wall deflections decrease by increasing the embedment ratio up to 1.50; however, any further increase in pile length does not improve the performance of wall. Similarly, increasing wall stiffness reduces the wall deformations and affects the deflection patterns of wall. The finite element analysis results are compared with field data of 25 case studies of cantilever walls. Analysis results fall within the range of normalized wall deflections of 25 case studies. It has been concluded that deep excavations can be supported by cantilever walls provided the system stiffness is increased significantly.Keywords: excavations, support systems, wall stiffness, cantilever walls
Procedia PDF Downloads 2104584 Effect of Particle Aspect Ratio and Shape Factor on Air Flow inside Pulmonary Region
Authors: Pratibha, Jyoti Kori
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Particles in industry, harvesting, coal mines, etc. may not necessarily be spherical in shape. In general, it is difficult to find perfectly spherical particle. The prediction of movement and deposition of non spherical particle in distinct airway generation is much more difficult as compared to spherical particles. Moreover, there is extensive inflexibility in deposition between ducts of a particular generation and inside every alveolar duct since particle concentrations can be much bigger than the mean acinar concentration. Consequently, a large number of particles fail to be exhaled during expiration. This study presents a mathematical model for the movement and deposition of those non-spherical particles by using particle aspect ratio and shape factor. We analyse the pulsatile behavior underneath sinusoidal wall oscillation due to periodic breathing condition through a non-Darcian porous medium or inside pulmonary region. Since the fluid is viscous and Newtonian, the generalized Navier-Stokes equation in two-dimensional coordinate system (r, z) is used with boundary-layer theory. Results are obtained for various values of Reynolds number, Womersley number, Forchsheimer number, particle aspect ratio and shape factor. Numerical computation is done by using finite difference scheme for very fine mesh in MATLAB. It is found that the overall air velocity is significantly increased by changes in aerodynamic diameter, aspect ratio, alveoli size, Reynolds number and the pulse rate; while velocity is decreased by increasing Forchheimer number.Keywords: deposition, interstitial lung diseases, non-Darcian medium, numerical simulation, shape factor
Procedia PDF Downloads 1854583 A Numerical Investigation of Flow Maldistribution in Inlet Header Configuration of Plate Fin Heat Exchanger
Authors: Appasaheb Raul
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Numerical analysis of a plate fin heat exchanger accounting for the effect of fluid flow maldistribution on the inlet header configuration of the heat exchanger is investigated. It is found that the flow maldistribution is very significant in normal to the flow direction. Various inlet configuration has been studied for various Reynolds Number. By the study, a modified header configuration is proposed and simulated. The two-dimensional parameters are used to evaluate the flow non-uniformity in the header, global flow maldistribution parameter (Sg), and Velocity Ratio (θ). A series of velocity vectors and streamline graphs at different cross-section are achieved and studied qualitatively with experimental results in the literature. The numerical result indicates that the flow maldistribution is serious in the conventional header while in the improved configuration less maldistribution occurs. The flow maldistribution parameter (Sg) and velocity ratio (θ) is reduced in improved configuration. The vortex decreases compared to that of the conventional configuration so the energy and pressure loss is reduced. The improved header can effectively enhance the efficiency of plate fin heat exchanger and uniformity of flow distribution.Keywords: global flow maldistribution parameter, Sg, velocity ratio, plate fin heat exchanger, fluent 14.5
Procedia PDF Downloads 5264582 Aspects of the Reproductive Biology of the Reticulate Knife Fish, Papyrocranus afer (Gunther, 1868) In Lekki Lagoon, Nigeria
Authors: Adiaha A. A. Ugwumba, Femi V. Oluwale
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Sizes at maturity (Lₘ₅₀), fecundity, sex ratio, and gonadosomatic indices (GSI) of the reticulate knife fish, Papyrocranus afer, collected from Lekki Lagoon, were investigated. A Total of 1154 specimens with standard lengths of 5.2-75.9 cm (mean = 34.86±17.2cm) and body weight of 7.9-1, 958.8g (mean = 249.12±28.56g) were collected by means of artisanal passive and active gears (traps, long lines, and nets) and examined. Sexes of fish specimens were determined macroscopically and microscopically after dissection. The length at which 50% of the fish population reached sexual maturity (Lₘ₅₀) was considered as length at sexual maturity. Fecundity was determined by total counts of eggs; sex ratio by the proportion of males to females, while GSI was determined as gonad weight expressed as a percentage of total body weight. Results showed that the most frequently caught fish was 34.5cm long, while the sizes at maturity were 49.1cm (males) and 53.4cm (females). Matured specimens had characteristic urinogenital papillae prominent in males but vestigial in females. Sex ratio (1: 0.6; Male: female) was significantly different (X² (1) = 32.21, p < 0.0001). Fecundity was low (mean 49 ± 17 eggs for a fish of 52.86 ±7.53cm); it increased with fish size (r = 0.71). Higher GSI during the rainy season with a peak in July (female: 0.44 ± 0.14 %; male: 0.22 ± 0.01 %) indicated seasonal/annual spawning. Low fecundity and annual spawning underlined the need for sustainable management of this species in Lekki Lagoon.Keywords: breeding season, fecundity, gonad maturity, Lekki lagoon, Papyrocranus afer, sex ratio
Procedia PDF Downloads 694581 Stress Concentration and Strength Prediction of Carbon/Epoxy Composites
Authors: Emre Ozaslan, Bulent Acar, Mehmet Ali Guler
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Unidirectional composites are very popular structural materials used in aerospace, marine, energy and automotive industries thanks to their superior material properties. However, the mechanical behavior of composite materials is more complicated than isotropic materials because of their anisotropic nature. Also, a stress concentration availability on the structure, like a hole, makes the problem further complicated. Therefore, enormous number of tests require to understand the mechanical behavior and strength of composites which contain stress concentration. Accurate finite element analysis and analytical models enable to understand mechanical behavior and predict the strength of composites without enormous number of tests which cost serious time and money. In this study, unidirectional Carbon/Epoxy composite specimens with central circular hole were investigated in terms of stress concentration factor and strength prediction. The composite specimens which had different specimen wide (W) to hole diameter (D) ratio were tested to investigate the effect of hole size on the stress concentration and strength. Also, specimens which had same specimen wide to hole diameter ratio, but varied sizes were tested to investigate the size effect. Finite element analysis was performed to determine stress concentration factor for all specimen configurations. For quasi-isotropic laminate, it was found that the stress concentration factor increased approximately %15 with decreasing of W/D ratio from 6 to 3. Point stress criteria (PSC), inherent flaw method and progressive failure analysis were compared in terms of predicting the strength of specimens. All methods could predict the strength of specimens with maximum %8 error. PSC was better than other methods for high values of W/D ratio, however, inherent flaw method was successful for low values of W/D. Also, it is seen that increasing by 4 times of the W/D ratio rises the failure strength of composite specimen as %62.4. For constant W/D ratio specimens, all the strength prediction methods were more successful for smaller size specimens than larger ones. Increasing the specimen width and hole diameter together by 2 times reduces the specimen failure strength as %13.2.Keywords: failure, strength, stress concentration, unidirectional composites
Procedia PDF Downloads 1554580 Disclosure of Financial Risk on Sharia Banks in Indonesia
Authors: Renny Wulandari
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This study aims to determine how the influence of Non Performing Financing, Financing Deposit Ratio, Operating Expenses and Operating Revenue and Net Income Margin on the disclosure of financial risk in Sharia banks. To achieve these objectives conducted associative research method with data source in the form of secondary data that is annual report data with period 2013-2016. The population in this study is the sharia banking industry in Indonesia and who issued the annual financial statements. A method of sampling use probability sampling. Analysis in this research is with SEM-PLS. The result is Net Income Margin has a significant effect on financial risk disclosure while Non Performing Financing (NPF) Financing to Deposit Ratio (FDR), Operating Expenses and Operating Revenue (OEOR) have no effect on the disclosure of financial risk in sharia bank.Keywords: Sharia banks, disclosure of risk financial, non performing financing, financing deposit ratio, operating expenses and operating revenue, net income margin
Procedia PDF Downloads 2344579 Preparation and Characterization of Nano-Metronidazole by Planetary Ball-Milling
Authors: Shahriar Ghammamy, Maryam Gholipoor
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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
Procedia PDF Downloads 4014578 Developing a New Relationship between Undrained Shear Strength and Over-Consolidation Ratio
Authors: Wael M Albadri, Hassnen M Jafer, Ehab H Sfoog
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Relationship between undrained shear strength (Su) and over consolidation ratio (OCR) of clay soil (marine clay) is very important in the field of geotechnical engineering to estimate the settlement behaviour of clay and to prepare a small scale physical modelling test. In this study, a relationship between shear strength and OCR parameters was determined using the laboratory vane shear apparatus and the fully automatic consolidated apparatus. The main objective was to establish non-linear correlation formula between shear strength and OCR and comparing it with previous studies. Therefore, in order to achieve this objective, three points were chosen to obtain 18 undisturbed samples which were collected with an increasing depth of 1.0 m to 3.5 m each 0.5 m. Clay samples were prepared under undrained condition for both tests. It was found that the OCR and shear strength are inversely proportional at similar depth and at same undrained conditions. However, a good correlation was obtained from the relationships where the R2 values were very close to 1.0 using polynomial equations. The comparison between the experimental result and previous equation from other researchers produced a non-linear correlation which has a similar pattern with this study.Keywords: shear strength, over-consolidation ratio, vane shear test, clayey soil
Procedia PDF Downloads 2824577 Instability of H2-O2-CO2 Premixed Flames on Flat Burner
Authors: Kaewpradap Amornrat, Endo Takahiro, Kadowaki Satoshi
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The combustion of hydrogen-oxygen (H2-O2) mixtures was investigated to consider the reduction of carbon dioxide (CO2) and nitrogen oxide (NOx) as the greenhouse emission. Normally, the flame speed of combustion H2-O2 mixtures are very fast thus it is necessary to control the limit of mixtures with CO2 addition as H2-O2-CO2 combustion. The limit of hydrogen was set and replaced by CO2 with O2:CO2 ratio as 1:3.76, 1:4 and 1:5 for this study. In this study, the combustion of H2-O2 -CO2 on flat burner at equivalence ratio =0.5 was investigated for 10, 15 and 20 L/min of flow rate mixtures. When the ratio of CO2 increases, the power spectral density is lower, the size of attractor and cellular flame become larger because the decrease of hydrogen replaced by CO2 affects the diffusive-thermal instability. Moreover, the flow rate mixtures increases, the power spectral density increases, the size of reconstructed attractor and cell size become smaller due to decreasing of instability. The results show that the variation of CO2 and mixture flow rate affects the instability of cellular premixed flames on flat burner.Keywords: instability, H2-O2-CO2 combustion, flat burner, diffusive-thermal instability
Procedia PDF Downloads 3614576 Utilizing Quicklime (Calcium Oxide) for Self-Healing Properties in Innovation of Coconut Husk Fiber Bricks
Authors: Christian Gabriel Mariveles, Darelle Jay Gallardo, Leslie Dayaoen, Laurenz Paul Diaz
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True experimental research with descriptive analysis was conducted. Utilizing Quicklime (Calcium Oxide) for self-healing properties of coconut husk fibre concrete brick. There are 2 setups established: the first one has the 1:1:2 ratio of calcium oxide, cement and sand, and the second one has a 2:1:2 ratio of the same variables. The bricks are made from the residences along Barangay Greater Lagro. The mixture of sand and cement is mixed with coconut husk fibers and then molded with different ratios in the molder. After the drying of cement, the researchers tested the bricks in the laboratory for compressive strength. The brick with the highest PSI is picked by the researchers to drop into freefall testing, and it makes remarkable remarks as it is deformed after dropping to different heights with a maximum of 20 feet. Unfortunately, the self-healing capabilities were not observed during the 12 weeks of monitoring. However, the brick was weighed after 12 weeks of monitoring, and it increased in weight by 0.030 kg. from 1.833 kg. to 1.863 kg. meaning that this ratio 2 has the potential to self-heal, but 12 weeks of monitoring by the researchers is not enough to conclude that it has a significant difference.Keywords: self healing, coconut husk bricks, research, calcium oxide, utilizing quicklime
Procedia PDF Downloads 424575 Numerical and Comparative Analysis between Two Composite Plates Notched in Different Shapes and Repaired by Composite
Authors: Amari Khaoula, Berrahou Mohamed
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The topic of our article revolves around a numerical and comparative analysis between two notched Boron/epoxy plates that are U-shaped and the other V-shaped, cracked, and repaired by a rectangular patch of the same composite material; the finite element method was used for the analytical study and comparison of the results obtained for determining the optimal shape of notch which will give a longer life to the repair. In this context, we studied the variation of the stress intensity factor, the evolution of the damaged area, and the calculation of the ratio of the damaged area according to the crack length and the concentration of the Von Mises stresses as a function of the lengths of the paths. According to the results obtained, we conclude that the notch plate U is the optimal one than notch plate V because it has lower values either for the stress intensity factor (SIF), damaged area ratio (Dᵣ), or the Von Mises stresses.Keywords: the notch U, the notch V, the finite element method FEM, comparison, rectangular patch, composite, stress intensity factor, damaged area ratio, Von Mises stresses
Procedia PDF Downloads 1004574 The Effect of Sulfur and Calcium on the Formation of Dioxin in a Bubbling Fluidized Bed Incinerator
Authors: Chien-Song Chyang, Wei-Chih Wang
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For the incineration process, the inhibition of dioxin formation is an important issue. Many investigations indicate that adding sulfur compounds in the combustion process can be an effectively inhibition for the dioxin formation. In the process, the ratio of sulfur-to-chlorine plays an important role for the reduction efficiency of dioxin formation. Ca-base sorbent is also a common used for the acid gas removing. Moreover, that is also the indirectly way for dioxin inhibition. Although sulfur and calcium can reduce the dioxin formation, it still have some confusion exists between these additives. To understand and clarify the relationship between the dioxin and simultaneous addition of sulfur and calcium are presented in this study. The experimental data conducted in a pilot scale fluidized bed combustion system at various operating conditions are analysis comprehensively. The focus is on the dioxin of fly ash in this study. The experimental data in this study showed that the PCDD/Fs concentration in the fly ash collected from the baghouse is increased slightly as the simultaneous addition of sulfur and calcium. This work described the CO concentration with the addition of sulfur and calcium at the freeboard temperature from 800°C to 900°C, which is raised by the fuel complexity. The positive correlation exists between the dioxin concentration and CO concentration and carbon contained in the fly ash.. At the same sulfur/chlorine ratio, the toxic equivalent quantity (TEQ) can be reduced by increasing the actual concentration of sulfur and calcium. The homologue profiles showed that the P₅CDD and P₅CDF were the two major sources for the toxicity of dioxin. 2,3,7,8-TCDD and 2,3,7,8-TCDF reduced by the addition of pyrite and hydrated lime. The experimental results showed that the trend of PCDD/Fs concentration in the fly ash was different by the different sulfur/chlorine ratio with the addition of sulfur at 800°C.Keywords: reduction of dioxin emissions, sulfur-to-chlorine ratio, de-chlorination, Ca-based sorbent
Procedia PDF Downloads 1474573 Effect of Green Manuring Jantar (Sesbania acculata. L.) on the Growth and Yield of Crops Grown in Wheat-Based Cropping Systems
Authors: Javed Kamal
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A proposed field study of wheat-based cropping systems was conducted at Faisalabad (Post-Graduate Research Station). We used 7 treatments and Jantar as a green manuring crop to increase the fertility status of soil; after the vegetative phases of wheat, rice, sorghum, and mungbean, the agronomic parameters of these crops were recorded. Hopefully, all increased with jantar treatment when compared with controls. The benefit: cost ratio and physicochemical characteristics of the soil before and after the crop harvest were also calculated.Keywords: benifit cost ratio, jantar, sunflower, rice, wheat
Procedia PDF Downloads 4024572 Iron Catalyst for Decomposition of Methane: Influence of Al/Si Ratio Support
Authors: A. S. Al-Fatesh, A. A. Ibrahim, A. M. AlSharekh, F. S. Alqahtani, S. O. Kasim, A. H. Fakeeha
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Hydrogen is the expected future fuel since it produces energy without any pollution. It can be used as a fuel directly or through the fuel cell. It is also used in chemical and petrochemical industry as reducing agent or in hydrogenation processes. It is produced by different methods such as reforming of hydrocarbon, electrolytic method and methane decomposition. The objective of the present paper is to study the decomposition of methane reaction at 700°C and 800°C. The catalysts were prepared via impregnation method using 20%Fe and different proportions of combined alumina and silica support using the following ratios [100%, 90%, 80%, and 0% Al₂O₃/SiO₂]. The prepared catalysts were calcined and activated at 600 OC and 500 OC respectively. The reaction was carried out in fixed bed reactor at atmospheric pressure using 0.3g of catalyst and feed gas ratio of 1.5/1 CH₄/N₂ with a total flow rate 25 mL/min. Catalyst characterizations (TPR, TGA, BET, XRD, etc.) have been employed to study the behavior of catalysts before and after the reaction. Moreover, a brief description of the weight loss and the CH₄ conversions versus time on stream relating the different support ratios over 20%Fe/Al₂O₃/SiO₂ catalysts has been added as well. The results of TGA analysis provided higher weights losses for catalysts operated at 700°C than 800°C. For the 90% Al₂O₃/SiO₂, the activity decreases with the time on stream using 800°C reaction temperature from 73.9% initial CH₄ conversion to 46.3% for a period of 300min, whereas the activity for the same catalyst increases from 47.1% to 64.8% when 700°C reaction temperature is employed. Likewise, for 80% Al₂O₃/SiO₂ the trend of activity is similar to that of 90% Al₂O₃/SiO₂ but with a different rate of activity variation. It can be inferred from the activity results that the ratio of Al₂O₃ to SiO₂ is crucial and it is directly proportional with the activity. Whenever the Al/Si ratio decreases the activity declines. Indeed, the CH₄ conversion of 100% SiO₂ support was less than 5%.Keywords: Al₂O₃, SiO₂, CH₄ decomposition, hydrogen, iron
Procedia PDF Downloads 1794571 Energy Saving in Handling the Air-Conditioning Latent-Load Using a Liquid Desiccant Air Conditioner: Parametric Experimental Analysis
Authors: Mustafa Jaradat
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Reasonable energy saving for dehumidification is feasible with the use of desiccants. Desiccants are able to lower the humidity content in the air irrespective of the dew point temperature. In this paper, a tube bundle liquid desiccant air conditioner was experimentally designed and evaluated using lithium chloride as a desiccant. Several experiments were conducted to evaluate the influence of the inlet parameters on the dehumidifier performance. The results show a reduction in the relative humidity in the range of 17 to 46%, and the change in the humidity ratio was between 1.5 to 4.7 g/kg, depending on the inlet conditions. A water removal rate in the range between 0.54 and 1.67 kg/h was observed. The effects of air relative humidity and the desiccant flow rate on the dehumidifier’s performance were investigated. It was found that the moisture removal rate remarkably increased with increasing desiccant flow rate and air inlet humidity ratio. The dehumidifier effectiveness increased sharply with increasing desiccant flow rate. Also, it was found that the dehumidifier effectiveness slightly decreased with air humidity ratio.Keywords: air conditioning, dehumidification, desiccant, lithium chloride, tube bundle
Procedia PDF Downloads 1444570 Nitric Oxide and Blood Based Ratios as Promising Immuno-Markers in Patients with Complicated Crohn’s Disease: Benefits for Predicting Therapy Response
Authors: Imene Soufli, Abdelkrim Hablal, Manel Amri, Moussa Labsi, Rania Sihem Boussa, Nassim Sid Idris, Chafia Touil-Boukoffa
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Crohn’s Disease (CD) is a relapsing–remitting inflammatory bowel disease with a progressive course. The aim of our study was to evaluate the relationship between the immunomarkers: Nitric Oxide (NO), pro-inflammatory cytokines, and blood count-based ratios and the outcome of corticosteroid or anti-TNF-α therapy in patients with complicated Crohn’s Disease. In this context, we evaluated the NLR as the ratio of neutrophil count to lymphocyte count, PLR as the ratio of platelet counts to lymphocyte count, and MLR as the ratio of monocyte count to lymphocyte count in patients and controls. Furthermore, we assessed NO production by the Griess method in plasma along with iNOS and NF-κB expression by immunofluorescence method in intestinal tissues of patients and controls. In the same way, we evaluated plasma TNF-α, IL-17A, and IL-10 levels using ELISA. Our results indicate that blood count-based ratios NLR, PLR, and MLR were significantly higher in patients compared to controls. In addition, increased systemic levels of NO, TNF-α, and IL-17A and colonic expression of iNOS and NF-κB were observed in the same patients. Interestingly, the high ratio of NLR and MLR, as well as NO production, was significantly decreased in treated patients. Collectively, our findings suggest that Nitric Oxide, as well as the blood count-based ratios (NLR, PLR, MLR), could constitute useful immuno-markers in complicated Crohn’s Disease, predicting the response to treatmentKeywords: complicated crohn’s disease, nitric oxide, blood count-based ratios, treatments, pro-inflammatory cytokines
Procedia PDF Downloads 79