Search results for: flow state

Authors: Poojan Gharat, Haridas Pal, Sharmistha Dutta Choudhury

Abstract:

Tuning photophysical properties of guest dyes through host-guest interactions involving macrocyclic hosts are the attractive research areas since past few decades, as these changes can directly be implemented in chemical sensing, molecular recognition, fluorescence imaging and dye laser applications. Excited state intramolecular proton transfer (ESIPT) is an intramolecular prototautomerization process display by some specific dyes. The process is quite amenable to tunability by the presence of different macrocyclic hosts. The present study explores the interesting effect of p-sulfonatocalix[n]arene (SCXn) and cyclodextrin (CD) hosts on the excited-state prototautomeric equilibrium of Chrysazine (CZ), a model antitumour drug. CZ exists exclusively in its normal form (N) in the ground state. However, in the excited state, the excited N* form undergoes ESIPT along with its pre-existing intramolecular hydrogen bonds, giving the excited state prototautomer (T*). Accordingly, CZ shows a single absorption band due to N form, but two emission bands due to N* and T* forms. Facile prototautomerization of CZ is considerably inhibited when the dye gets bound to SCXn hosts. However, in spite of lower binding affinity, the inhibition is more profound with SCX6 host as compared to SCX4 host. For CD-CZ system, while prototautomerization process is hindered by the presence of β-CD, it remains unaffected in the presence of γCD. Reduction in the prototautomerization process of CZ by SCXn and βCD hosts is unusual, because T* form is less dipolar in nature than the N*, hence binding of CZ within relatively hydrophobic hosts cavities should have enhanced the prototautomerization process. At the same time, considering the similar chemical nature of two CD hosts, their effect on prototautomerization process of CZ would have also been similar. The atypical effects on the prototautomerization process of CZ by the studied hosts are suggested to arise due to the partial inclusion or external binding of CZ with the hosts. As a result, there is a strong possibility of intermolecular H-bonding interaction between CZ dye and the functional groups present at the portals of SCXn and βCD hosts. Formation of these intermolecular H-bonds effectively causes the pre-existing intramolecular H-bonding network within CZ molecule to become weak, and this consequently reduces the prototautomerization process for the dye. Our results suggest that rather than the binding affinity between the dye and host, it is the orientation of CZ in the case of SCXn-CZ complexes and the binding stoichiometry in the case of CD-CZ complexes that play the predominant role in influencing the prototautomeric equilibrium of the dye CZ. In the case of SCXn-CZ complexes, the results obtained through experimental findings are well supported by quantum chemical calculations. Similarly for CD-CZ systems, binding stoichiometries obtained through geometry optimization studies on the complexes between CZ and CD hosts correlate nicely with the experimental results. Formation of βCD-CZ complexes with 1:1 stoichiometry while formation of γCD-CZ complexes with 1:1, 1:2 and 2:2 stoichiometries are revealed from geometry optimization studies and these results are in good accordance with the observed effects by the βCD and γCD hosts on the ESIPT process of CZ dye.

Keywords: intermolecular proton transfer, macrocyclic hosts, quantum chemical studies, photophysical studies

Procedia PDF Downloads 121

Authors: Inese Trusina, Elita Jermolajeva, Viktors Gopejenko, Viktor Abramov

Abstract:

Global challenges require a transition from the existing linear economic model to a model that will consider nature as a life support system for the development of the way to social well-being in the frame of the ecological economics paradigm. The objective of the article is to present the results of the analysis of socio-economic systems in the context of sustainable development using the systems power (energy flows) changes analyzing method and structural Kaldor's model of GDP. In accordance with the principles of life's development and the ecological concept was formalized the tasks of sustainable development of the open, non-equilibrium, stable socio-economic systems were formalized using the energy flows analysis method. The methodology of monitoring sustainable development and level of life were considered during the research of interactions in the system ‘human - society - nature’ and using the theory of a unified system of space-time measurements. Based on the results of the analysis, the time series consumption energy and economic structural model were formulated for the level, degree and tendencies of sustainable development of the system and formalized the conditions of growth, degrowth and stationarity. In order to design the future state of socio-economic systems, a concept was formulated, and the first models of energy flows in systems were created using the tools of system dynamics. During the research, the authors calculated and used a system of universal indicators of sustainable development in the invariant coordinate system in energy units. In order to design the future state of socio-economic systems, a concept was formulated, and the first models of energy flows in systems were created using the tools of system dynamics. In the context of the proposed approach and methods, universal sustainable development indicators were calculated as models of development for the USA and China. The calculations used data from the World Bank database for the period from 1960 to 2019. Main results: 1) In accordance with the proposed approach, the heterogeneous energy resources of countries were reduced to universal power units, summarized and expressed as a unified number. 2) The values of universal indicators of the life’s level were obtained and compared with generally accepted similar indicators.3) The system of indicators in accordance with the requirements of sustainable development can be considered as a basis for monitoring development trends. This work can make a significant contribution to overcoming the difficulties of forming socio-economic policy, which is largely due to the lack of information that allows one to have an idea of the course and trends of socio-economic processes. The existing methods for the monitoring of the change do not fully meet this requirement since indicators have different units of measurement from different areas and, as a rule, are the reaction of socio-economic systems to actions already taken and, moreover, with a time shift. Currently, the inconsistency or inconsistency of measures of heterogeneous social, economic, environmental, and other systems is the reason that social systems are managed in isolation from the general laws of living systems, which can ultimately lead to a systemic crisis.

Keywords: sustainability, system dynamic, power, energy flows, development

Procedia PDF Downloads 58

Authors: Marco Avila Lopez, Hasnae Ait-Douchi, Silvia De Los Santos, Badr Eddine Lebrouhi, Pamela Ramírez Vidal

Abstract:

In the context of the energy transition, fuel cell technology has emerged as a solution for harnessing hydrogen energy and mitigating greenhouse gas emissions. An in-depth study was conducted on a PEMFC-type fuel cell, with an initiation of an analysis of its operational principles and constituent components. Subsequently, the modelling of the fuel cell was undertaken using the Python programming language, encompassing both steady-state and transient regimes. In the case of the steady-state regime, the physical and electrochemical phenomena occurring within the fuel cell were modelled, with the assumption of uniform temperature throughout all cell compartments. Parametric identification was carried out, resulting in a remarkable mean error of only 1.62% when the model results were compared to experimental data documented in the literature. The dynamic model that was developed enabled the scrutiny of the fuel cell's response in terms of temperature and voltage under varying current conditions.

Keywords: fuel cell, modelling, dynamic, thermal model, PEMFC

Procedia PDF Downloads 81

Authors: Vaishnavi Shivde, Shrishti Sinha, Trapti Mishra

Abstract:

Traffic light detection from a moving vehicle is an important technology both for driver safety assistance functions as well as for autonomous driving in the city. This paper proposed a deep-learning-based traffic light recognition method that consists of a pixel-wise image segmentation technique and a fully convolutional network i.e., UNET architecture. This paper has used a method for detecting the position and recognizing the state of the traffic lights in video sequences is presented and evaluated using Traffic Light Dataset which contains masked traffic light image data. The first stage is the detection, which is accomplished through image processing (image segmentation) techniques such as image cropping, color transformation, segmentation of possible traffic lights. The second stage is the recognition, which means identifying the color of the traffic light or knowing the state of traffic light which is achieved by using a Convolutional Neural Network (UNET architecture).

Keywords: traffic light detection, image segmentation, machine learning, classification, convolutional neural networks

Procedia PDF Downloads 173

Authors: E. E. S. Uy, T. Noda, K. Nakai, J. R. Dungca

Abstract:

Cyclic threshold shear strain is the cyclic shear strain amplitude that serves as the indicator of the development of pore water pressure. The parameter can be obtained by performing either cyclic triaxial test, shaking table test, cyclic simple shear or resonant column. In a cyclic triaxial test, other researchers install measuring devices in close proximity of the soil to measure the parameter. In this study, an attempt was made to estimate the cyclic threshold shear strain parameter using full-field measurement technique. The technique uses a camera to monitor and measure the movement of the soil. For this study, the technique was incorporated in a strain-controlled consolidated undrained cyclic triaxial test. Calibration of the camera was first performed to ensure that the camera can properly measure the deformation under cyclic loading. Its capacity to measure deformation was also investigated using a cylindrical rubber dummy. Two-dimensional image processing was implemented. Lucas and Kanade optical flow algorithm was applied to track the movement of the soil particles. Results from the full-field measurement technique were compared with the results from the linear variable displacement transducer. A range of values was determined from the estimation. This was due to the nonhomogeneous deformation of the soil observed during the cyclic loading. The minimum values were in the order of 10-2% in some areas of the specimen.

Keywords: cyclic loading, cyclic threshold shear strain, full-field measurement, optical flow

Procedia PDF Downloads 234

Authors: U. V. Okpala

Abstract:

Flood is an overflow of water that submerges or ‘drowns’ land. In developing countries it occurs as a result of blocking of natural and man-made drainages and poor maintenance of water dams/reservoirs which seldom give way after persistent heavy down pours. In coastal lowlands and swamp lands, flooding is aided mainly by blocked channels and indiscriminate sand fling of coastal swamp areas and natural drainage channel for urban development/constructions. In this paper, the causes of flood and possible scientific, technological, political, economic and social impacts of flood disaster on the environment a case study of Anambra State have been studied. Often times flooding is caused by climate change, especially in the developed economy where scientific mitigating options are highly employed. Researchers have identified Green Houses Gases (GHG) as the cause of global climate change. The recent flood disaster in Anambra State which caused physical damage to structures, social dislocation, contamination of clean drinking water, spread of water-borne diseases, shortage of crops and food supplies, death of non-tolerant tree species, disruption in transportation system, serious economic loss and psychological trauma is a function of climate change. There is need to encourage generation of renewable energy sources, use of less carbon intensive fuels and other energy efficient sources. Carbon capture/sequestration, proper management of our drainage systems and good maintenance of our dams are good option towards saving the environment.

Keywords: flooding, climate change, carbon capture, energy systems

Procedia PDF Downloads 375

Authors: Aina Barcelona, Carolyn Oldham, Jordi Colomer, Jordi Garcia-Orellana, Teresa Serra

Abstract:

Seagrass meadows increase the sedimentation within the canopy. However, there is still a lack of knowledge about how seagrasses impact the vertical distribution of sediment coming from external sources and reaches the meadow. This study aims to determine the number of particles retained by a seagrass meadow. Based on the hydrodynamics in the vertical direction, a meadow can be separated into different compartments: the blades, the seabed, within the canopy layer, and the above canopy layer. A set of laboratory experiments were conducted under different hydrodynamic conditions and canopy densities with the purpose to mimic the real field conditions. This study demonstrates and quantifies that seagrass meadows decrease the volume of the suspended sediment by two mechanisms: capturing the suspended sediment by the seagrass blades and promoting the particle sedimentation to the seabed. This study also demonstrates that the number of sediment particles trapped by single seagrass blades decreases with canopy density. However, when considering the trapping by the total number of blades, the sediment captured by all the blades of the meadow increases with canopy density. Furthermore, comparing with the bare seabed, this study demonstrated that there is a reduction in the suspended particles within the canopy, which implies an improvement in the water clarity. In addition, the particle sedimentation on the seabed increases with the canopy density compared with the bare seabed, making evident the contribution of the vegetation in enhancing sedimentation.

Keywords: seagrass, sediment capture, turbulent kinetic energy, oscillatory flow

Procedia PDF Downloads 235

Authors: Hemant Kumar, R. N. K. Sharma, A. P. Krishna

Abstract:

The study has been carried out on the Saranda in Jharkhand and a part of Odisha state. Geospatial data of Hyperion, a remote sensing satellite, have been used. This study has used a wide variety of patterns related to image processing to enhance and extract the mining class of Fe and Mn ores.Landsat-8, OLI sensor data have also been used to correctly explore related minerals. In this way, various processes have been applied to increase the mineralogy class and comparative evaluation with related frequency done. The Hyperion dataset for hyperspectral remote sensing has been specifically verified as an effective tool for mineral or rock information extraction within the band range of shortwave infrared used. The abundant spatial and spectral information contained in hyperspectral images enables the differentiation of different objects of any object into targeted applications for exploration such as exploration detection, mining.

Keywords: Hyperion, hyperspectral, sensor, Landsat-8

Procedia PDF Downloads 124

Authors: Giorgi Gaprindashvili

Abstract:

One of the best examples, in evolution of the public procurement, from post-soviet countries are reforms carried out in Georgia, which brought them close to international standards of procurement. In Georgia, public procurement legislation started functioning in 1998. The reform has passed several stages and came in the form as it is today. It should also be noted, that countries with economy in transition, including Georgia, implemented all the reforms in public procurement based on recommendations and support of World Bank, the United Nations and other international organizations. The first law on public procurement in Georgia was adopted on December 9, 1998 which aimed regulation of the procurement process of budget-organizations, transparent and competitive environment for private companies to access state funds legally. The priorities were identified quite clearly in the wording of the law, but operation/function of this law could not be reached on its level, because of some objective and subjective reasons. The high level of corruption in all levels of governance, can be considered as a main obstacle reason and of course, it is natural, that it had direct impact on the procurement process, as well as on transparency and rational use of state funds. This circumstances were the reasons that reforms in this sphere continued, to improve procurement process, in particular, the first wave of reforms began in 2001. Public procurement agency carried out reform with World Bank with main purpose of smartening the procurement legislation and its harmonization with international treaties and agreements. Also with the support of World Bank various activities were carried out to raise awareness of participants involved in procurement system. Further major changes in the legislation were filed in May 2005, which was also directed towards the improvement and smarten of the procurement process. The third wave of the reform began in 2010, which more or less guaranteed the transparency of the procurement process, which later became the basis for the rational spending of state funds. The reform of the procurement system completely changed the procedures. Carried out reform in Georgia resulted in introducing new electronic tendering system, which benefit the transparency of the process, after this became the basis for the further development of a competitive environment, which become a prerequisite for the state rational spending. Increased number of supplier organizations participating in the procurement process resulted in reduction of the estimated cost and the actual cost from 20% up to 40%, it is quite large saving for the procuring organizations and allows them to use the freed-up funds for their other needs. Assessment of the reforms in Georgia in the field of public procurement can be concluded, that proper regulation of the sector and relevant policy may proceed to rational and transparent spending of the budget from country’s state institutions. Also, the business sector has the opportunity to work in competitive market conditions and to make a preliminary analysis, which is a prerequisite for future strategy and development.

Keywords: public administration, public procurement, reforms, transparency

Procedia PDF Downloads 366

Authors: Frederik Calsius, Mirela Popa, Alexia Briassouli

Abstract:

In the field of machine learning, it is common practice to use benchmark datasets to prove the working of a method. The domain of action recognition in videos often uses datasets like Kinet-ics, Something-Something, UCF-101 and HMDB-51 to report results. Considering the properties of the datasets, there are no datasets that focus solely on very short clips (2 to 3 seconds), and on highly-similar fine-grained actions within one specific domain. This paper researches how current state-of-the-art action recognition methods perform on a dataset that consists of highly similar, fine-grained actions. To do so, a dataset of skateboarding tricks was created. The performed analysis highlights both benefits and limitations of state-of-the-art methods, while proposing future research directions in the activity recognition domain. The conducted research shows that the best results are obtained by fusing RGB data with OpenPose data for the Temporal Shift Module.

Keywords: activity recognition, fused deep representations, fine-grained dataset, temporal modeling

Procedia PDF Downloads 231

Authors: Myrto Dagkouli-Kyriakoglou

Abstract:

Southern European countries tend to have a lot of connections in their culture, customs, ideals and attitude towards everyday aspects. On the contrary, all of them demonstrate a lot of differences in their history, political life and economic situation. Nevertheless, the state welfare and its insufficiency to deal with citizens’ needs, is common for the whole region. As the global financial crisis initiated, all of them gradually were affected and established austerity measures. Consequently, there were crucial budget cuts in state welfare and accordingly limited support to the citizens at a time that is most needed as the economic difficulties of the households are rising rapidly. Crisis in connection with austerity measures brought up a housing problem which was hidden for decades with the assistance of the institution of the Southern European family. New or old copying practices concerning housing are already developed and more will rise in order to survive this new era. Expressly, youth is one of the most vulnerable groups in this situation and therefore there is a special focus on the policies that affect their housing as well as their copying practices in connection with the family/kinship strategies.

Keywords: housing, coping practices, Greece, familism

Procedia PDF Downloads 348

Authors: Tamar Khardziani, Violeta Berikashvili, Mariam Rusitashvili, Eva Kachlishvili, Vladimir Elisashvili, Mikheil Asatiani

Abstract:

Last years, the search for natural sources of novel and effective antifungal substances became a scientific and technological challenge. In the present research, thirty basidiomycetes isolated from various ecological niches of Georgia and belonging to different taxonomic groups were screened for their antifungal activities against pathogenic fungi such as Aspergillus, Fusarium, and Guignardia bidwellii. Among mushroom tested, several potential producers of antifungal substances have been revealed, such as Schizophyllum commune, Lentinula edodes, Ganoderma abietinum, Fomes fomentarius, Hericium erinaceus, and Trametes versicolor. For mushroom cultivation and expression of antifungal potential, submerged and solid-state fermentations of different plant raw materials were performed and various approaches and strategies have been exploited. Sch. commune appeared as a most promising producer of antifungal compounds. It was established that among different agro-industrial wastes, the presence of mandarin juice production waste in a nutrient medium, causing the significant increase of antifungal activity Sch. commune (growth inhibition: Aspergillus – 59 %, Fusarium – 55 %, G. bidwellii – 78 %, after 3, 2 and 4 days of cultivation, respectively). Besides this, Sch. commune demonstrate similar antifungal activities in the presence of glucose, glycerol, maltose, mannitol, and xylose, and growth inhibition of Fusarium ranged in 41 % - 49 % during 6 days of cultivation. Inhibition of Aspergillus growth inhibition varied in 27 % - 36 %, and inhibition of G. bidwellii was in the range 49 % - 61 %, respectively. Sch. commune under solid-state fermentation of mandarin peels at 13 days of cultivation demonstrates powerful growth inhibition of pathogenic fungi (growth inhibition: Aspergillus – 50 %, Fusarium – 61 %, G. bidwellii – 68 %, after 3, 4, and 4 days of cultivation, respectively) as well as at 20 days old mushroom (growth inhibition: Aspergillus – 41 %, Fusarium – 54 %, G. bidwellii – 66 %, after 3 days of cultivation). It was established that Sch. commune was effective as a producer of antifungal compounds in submerged as well as in solid-state fermentation. Finally, performed study confirms that the higher basidiomycetes possess antifungal potential, which strongly depends on the physiological factors of growth. Acknowledgments: The work was implemented with the financial support of fundamental science project FR-19-3719 by the Shota Rustaveli National Science Foundation of Georgia.

Keywords: antifungal potential, higher basidiomycetes, pathogenic fungi, submerged and solid-state fermentation

Procedia PDF Downloads 144

Authors: Hamid Boustanifar, Geraldo Cerqueiro, María Fabiana Penas

Abstract:

We exploit state-level changes in the amount of personal wealth individuals can protect under Chapter 7 to analyze the causal effect of debtor protection on income inequality. We find that an increase in state exemptions significantly increases inequality by reducing income for low-income individuals and by increasing income for high-income individuals. The increase in inequality is four times larger among the self-employed than among wage earners, and it is due mainly to a growing income gap between skilled (i.e., individuals with a college degree) and unskilled entrepreneurs. We also find that the employment rate of skilled entrepreneurs significantly increases, while the employment rate of unskilled wage earners falls. Our results are consistent with a recent literature that shows that higher exemptions redistribute credit from low-wealth to high-wealth entrepreneurs, affecting the performance of their businesses.

Keywords: debtor protection, credit markets, income inequality, debtor protection laws

Procedia PDF Downloads 432

Authors: Mananya Meenakorn

Abstract:

The purpose of this study is to examine the impact of public enterprise reform policy on the attributes of organizational commitments in the public energy enterprises in Thailand. It compares three structural types of public energy enterprises: totally state-owned public enterprises, partially transformed public enterprises and totally transformed public enterprises, based on the degree of state ownership and the level of management control that exist in the public reformed organizations, by analyzing the presence of the desirable attributes of organizational commitment as perceived by employees. Findings indicate that there are statistically significant differences in the level of some dimensions of organizational commitment between the three types of public energy enterprises. The results also indicate empirical evidence concerning the causal relationship between the antecedents and organizational commitment. Whereas change-related behaviors show a direct negative influence on organizational commitment, both HRM practices and work-related values indicate direct positive influences on them also.

Keywords: affective commitment, organizational commitment, public enterprise reform organizations, public energy enterprises in Thailand

Procedia PDF Downloads 294

Authors: Mustapha Kamel Mihoubi, Essadik Kerkar, Abdelhamid Hebbouche

Abstract:

According to the randomness of most of the factors affecting the stability of a gravity dam, probability theory is generally used to TESTING the risk of failure and there is a confusing logical transition from the state of stability failed state, so the stability failure process is considered as a probable event. The control of risk of product failures is of capital importance for the control from a cross analysis of the gravity of the consequences and effects of the probability of occurrence of identified major accidents and can incur a significant risk to the concrete dam structures. Probabilistic risk analysis models are used to provide a better understanding the reliability and structural failure of the works, including when calculating stability of large structures to a major risk in the event of an accident or breakdown. This work is interested in the study of the probability of failure of concrete dams through the application of the reliability analysis methods including the methods used in engineering. It is in our case of the use of level II methods via the study limit state. Hence, the probability of product failures is estimated by analytical methods of the type FORM (First Order Reliability Method), SORM (Second Order Reliability Method). By way of comparison, a second level III method was used which generates a full analysis of the problem and involving an integration of the probability density function of, random variables are extended to the field of security by using of the method of Mont-Carlo simulations. Taking into account the change in stress following load combinations: normal, exceptional and extreme the acting on the dam, calculation results obtained have provided acceptable failure probability values which largely corroborate the theory, in fact, the probability of failure tends to increase with increasing load intensities thus causing a significant decrease in strength, especially in the presence of combinations of unique and extreme loads. Shear forces then induce a shift threatens the reliability of the structure by intolerable values of the probability of product failures. Especially, in case THE increase of uplift in a hypothetical default of the drainage system.

Keywords: dam, failure, limit state, monte-carlo, reliability, probability, sliding, Taylor

Procedia PDF Downloads 318

Authors: M. Nadeem, Y. K. Chang, C. Diallo, U. Venkatadri, P. Havard, T. Nguyen-Quang

Abstract:

Uniform distribution of agro-chemicals is highly important because there is a significant loss of agro-chemicals, for example from pesticide, during spraying due to non-uniformity of droplet and off-target drift. Improving the efficiency of spray pattern for different cropping systems would reduce energy, costs and to minimize environmental pollution. In this paper, we examine the water jet patterns in order to study the performance and uniformity of water distribution during the spraying process. We present a method to quantify the water amount from a sprayer jet by using the Particle Image Velocimetry (PIV) system. The results of the study will be used to optimize sprayer or nozzles design for chemical application. For this study, ten sets of images were acquired by using the following PIV system settings: double frame mode, trigger rate is 4 Hz, and time between pulsed signals is 500 µs. Each set of images contained different numbers of double-framed images: 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 at eight different pressures 25, 50, 75, 100, 125, 150, 175 and 200 kPa. The PIV images obtained were analysed using custom-made image processing software for droplets and volume calculations. The results showed good agreement of both manual and PIV measurements and suggested that the PIV technique coupled with image processing can be used for a precise quantification of flow through nozzles. The results also revealed that the method of measuring fluid flow through PIV is reliable and accurate for sprayer patterns.

Keywords: image processing, PIV, quantifying the water volume from nozzle, spraying pattern

Procedia PDF Downloads 237

Authors: Seon Tae Kim, Robert Hegner, Goksel Ozuylasi, Panagiotis Stathopoulos, Eberhard Nicke

Abstract:

High-temperature heat pumps (HTHP) that can supply heat at temperatures above 200°C can enhance the energy efficiency of industrial processes and reduce the CO₂ emissions connected with the heat supply of these processes. In the current work, the thermodynamic performance of 3 different vapor compression cycles, which use R-718 (water) as a working medium, have been evaluated by using a commercial process simulation tool (EBSILON Professional). All considered cycles use two-stage vapor compression with intercooling between stages. The main aim of the study is to compare different intercooling strategies and study possible heat recovery scenarios within the intercooling process. This comparison has been carried out by computing the coefficient of performance (COP), the heat supply temperature level, and the respective mass flow rate of water for all cycle architectures. With increasing temperature difference between the heat source and heat sink, ∆T, the COP values decreased as expected, and the highest COP value was found for the cycle configurations where both compressors have the same pressure ratio (PR). The investigation on the HTHP capacities with optimized PR and exergy analysis has also been carried out. The internal heat exchanger cycle with the inward direction of secondary flow (IHX-in) showed a higher temperature level and exergy efficiency compared to other cycles. Moreover, the available operating range was estimated by considering mechanical limitations.

Keywords: high temperature heat pump, industrial process, vapor compression cycle, R-718 (water), thermodynamic analysis

Procedia PDF Downloads 149

Authors: Magdi M. E. Zumrawi

Abstract:

Crossing culverts are essential element of rural roads. The paper aims to investigate failures of recently constructed wadi-crossing pipe culverts in Sennar state and provide necessary remedial measures. The investigation is conducted to provide an extensive diagnosis study in order to find out the main structural and hydrological weaknesses of the culverts. Literature of steel pipe culverts related to construction practices and common types of culvert failures and their appropriate mitigation measures were reviewed. A detailed field survey was conducted to detect failures and defects appeared on the existing culverts. The results revealed that seepage of water through the embankment and foundation of the culverts leads to excessive erosion and scouring causing sever failures and damages. The design mistakes and poor construction were detected as the main causes of culverts failures. For sustainability of the culverts, various remedial measures are recommended to be considered in urgent rehabilitation of the existing crossings.

Keywords: culvert, erosion, failure, sustainability

Procedia PDF Downloads 309

Authors: Hee-Chang Lim

Abstract:

The study aims to understand the surface pressure distribution around the bodies such as the suction pressure in the leading edge on the top and side-face when the aspect ratio of bodies and the wind direction are changed, respectively. We carried out the wind tunnel measurement and numerical simulation around a series of rectangular bodies (40^d×80^w×80^h, 80^d×80^w×80^h, 160^d×80^w×80^h, 80^d×40^w×80^h and 80^d×160^w×80^h in mm³) placed in a deep turbulent boundary layer. Based on a modern numerical platform, the Navier-Stokes equation with the typical 2-equation (k-ε model) and the DES (Detached Eddy Simulation) turbulence model has been calculated, and they are both compared with the measurement data. Regarding the turbulence model, the DES model makes a better prediction comparing with the k-ε model, especially when calculating the separated turbulent flow around a bluff body with sharp edged corner. In order to observe the effect of wind direction on the pressure variation around the cube (e.g., 80^d×80^w×80^h in mm), it rotates at 0º, 10º, 20º, 30º, and 45º, which stands for the salient wind directions in the tunnel. The result shows that the surface pressure variation is highly dependent upon the approaching wind direction, especially on the top and the side-face of the cube. In addition, the transverse width has a substantial effect on the variation of surface pressure around the bodies, while the longitudinal length has little or no influence.

Keywords: rectangular bodies, wind direction, aspect ratio, surface pressure distribution, wind-tunnel measurement, k-ε model, DES model, CFD

Procedia PDF Downloads 236

Authors: Hamid El Qarnia

Abstract:

This study investigates the impact of the eccentricity of the central tube on the thermal and fluid characteristics of a triplex tube used in latent heat energy storage technologies. Two triplex tube orientations are considered in the proposed study: vertical and horizontal. The energy storage material, which is a phase change material (PCM), is placed in the space between the inside and outside tubes. During the thermal energy storage period, a heat transfer fluid (HTF) flows inside the two tubes, transmitting the heat to the PCM through two heat exchange surfaces instead of one heat exchange surface as it is the case for double tube heat storage systems. A CFD model is developed and validated against experimental data available in the literature. The mesh independency study is carried out to select the appropriate mesh. In addition, different time steps are examined to determine a time step ensuring accuracy of the numerical results and reduction in the computational time. The numerical model is then used to conduct numerical investigations of the thermal behavior and thermal performance of the storage unit. The effects of eccentricity of the central tube and HTF mass flow rate on thermal characteristics and performance indicators are examined for two flow arrangements: co-current and counter current flows. The results are given in terms of isotherm plots, streamlines, melting time and thermal energy storage efficiency.

Keywords: energy storage, heat transfer, melting, solidification

Procedia PDF Downloads 56

Authors: Ayodeji O. Falade, Leonard V. Mabinya, Uchechukwu U. Nwodo, Anthony I. Okoh

Abstract:

Given the high utility of peroxidase in several industrial processes, the search for novel microorganisms with enhanced peroxidase production capacity is of keen interest. This study investigated the process conditions for optimum peroxidase production by Ensifer sp, new ligninolytic proteobacteria with peroxidase production potential. Also, some agricultural residues were valorized for peroxidase production under solid state fermentation. Peroxidase production was optimum at an initial medium pH 7, incubation temperature of 30 °C and agitation speed of 100 rpm using alkali lignin fermentation medium supplemented with guaiacol as the most effective inducer and ammonium sulphate as the best inorganic nitrogen. Optimum peroxidase production by Ensifer sp. was attained at 48 h with specific productivity of 12.76 ± 1.09 U mg⁻¹. Interestingly, probable laccase production was observed with optimum specific productivity of 12.76 ± 0.45 U mg⁻¹ at 72 h. The highest peroxidase yield was observed with sawdust as solid substrate under solid state fermentation. In conclusion, Ensifer sp. possesses the capacity for enhanced peroxidase production that can be exploited for various biotechnological applications.

Keywords: catalase-peroxidase, enzyme production, peroxidase, polymerase chain reaction, proteobacteria

Procedia PDF Downloads 307

Authors: P. C. Tewari, Parveen Kumar

Abstract:

The paper describes the availability analysis of milling system of a rice milling plant using probabilistic approach. The subsystems under study are special purpose machines. The availability analysis of the system is carried out to determine the effect of failure and repair rates of each subsystem on overall performance (i.e. steady state availability) of system concerned. Further, on the basis of effect of repair rates on the system availability, maintenance repair priorities have been suggested. The problem is formulated using Markov Birth-Death process taking exponential distribution for probable failures and repair rates. The first order differential equations associated with transition diagram are developed by using mnemonic rule. These equations are solved using normalizing conditions and recursive method to drive out the steady state availability expression of the system. The findings of the paper are presented and discussed with the plant personnel to adopt a suitable maintenance policy to increase the productivity of the rice milling plant.

Keywords: availability modeling, Markov process, milling system, rice milling plant

Procedia PDF Downloads 234

Authors: Djalal Hamed

Abstract:

The aim of this paper is to perform an analytic solution of steady state natural convection in a narrow rectangular channel between two vertical parallel MTR-type fuel plates, imposed under a cosine shape heat flux to determine the margin of the nuclear core power at which the natural convection cooling mode can ensure a safe core cooling, where the cladding temperature should not be reach the specific safety limits (90 °C). For this purpose, a simple computer program is developed to determine the principal parameter related to the nuclear core safety such as the temperature distribution in the fuel plate and in the coolant (light water) as a function of the reactor power. Our results are validated throughout a comparison against the results of another published work, which is considered like a reference of this study.

Keywords: buoyancy force, friction force, natural convection, thermal hydraulic analysis, vertical heated rectangular channel

Procedia PDF Downloads 316

Authors: Marcello Lussana

Abstract:

Closer is a wireless system developed by the “Design Research Lab” of the UdK Berlin that is able to detect the proximity and touch between two (or more) persons. We have been using this system for one performance and one installation: in both cases, the proximity and touch events of the two participants have been sonified using the software Supercollider. In this paper, we are going to focus on the actual experience of the participants involved, especially related to the awareness of their body, their level of proprioception and how they felt in their body and in connection with the other person. In order to give value to the lived experience of the participant, a phenomenological method described and developed by Professor Claire Petitmengin has been used. This strategy allowed the interviewees to become aware of their subjective experience, and describe it with great precision. This is essential in order to understand the actual state of consciousness of the users. Our aim is to research the senses of proprioception, touch, and proximity: as they all involve a pre-reflective state of consciousness, they are central for the understanding of human perception. The interviews revealed how this experience could improve and increase proprioception and awareness of your body.

Keywords: interactive sound, phenomenology, pre-reflective, proprioception, subjective experience

Procedia PDF Downloads 247

Authors: Akhter Hussain Najar

Abstract:

Honey bees are the best insect grown on earth and are taking the lead in the global ecosystem. Life on earth depends upon honey bees pollinating each and every flower in its reign. The global economy is balanced by providing financial attribute due to the use of valuable resources generated from honey bees like honey, royal jelly, bee venom, propolis, bee wax even queens from parent colonies is now in demand. Livelihood stability is also maintained by the rearing of honey bees; beekeeping became a new professional work to be cared for by the experts. Indigenous methodologies are used to rear honey bees. The rearing of honey bees showed variation in different states like Uttar Pradesh, Rajasthan, Haryana, Punjab, Jammu, Kashmir, etc. The production of honey depends upon the area and the availability of crops and the colonies of beekeepers in these states. However, the kind of honey from Jammu and Kashmir, like Accacia and Solai, has different color and odour from the honey generated in the rest of the states. However, the nature and viscosity vary from state to state. But in the last few years, the honey from Jammu and Kashmir has given different shapes when kept at room temperature due to unconditional rainfall during honey peak season in J&K.

Keywords: ecosystem pollen, pollination, honey bee

Procedia PDF Downloads 107

Authors: Peter O. Nwadike, Sylvia O. Anyadoh-Nwadike, Chukwunonyerem Ogwunga, I. N. S. Dozie

Abstract:

Purpose: This study was aimed at determining the knowledge and attitude of female workers in six selected rural Local Government Areas of Imo State (Ezinihitte Mbaise, Ngor Okpala, Ohaji/Egbema, Ideato South, Ihitte Uboma and Obowo) towards cervical cancer and its screening. Methodology: Data was collected using a validated open-ended, semi-structured questionnaire. After responses to the questionnaire were received, a seminar on Cervical cancer and its screening was delivered to the respondents. Afterward, a second set of the same questionnaires was administered to the same respondents. A total of 460 women of reproductive age were randomly selected upon their informed consent. Data obtained/responses were analyzed using simple percentages. The chi-square test was used to assess the relationship by testing the hypothesis. Result: Results revealed that, before the seminar, a high average percentage of 72.2% (332) of respondents had not heard of cervical cancer while 27.8% (128) had heard. Of those who know about Cervical cancer, an average of 70.3% (90) showed low knowledge. The majority of respondents, 366 (79.6%), had poor attitudes toward screening. They mostly implicated lack of awareness 205 (44.6%) and lack of funds 104 (22.6%) as major reasons for not participating in the screening test. Few 128 (27.8%) agreed to go for screening and vaccination. After the awareness, 400 (87%) agreed to go for the screening test and vaccination if free/affordable. None of the participants had ever been screened. A significant relationship between attitude to cervical cancer and level of knowledge and academic level and attitude to cervical cancer screening was obtained. Conclusion: This calls for continued enlightenment about cervical cancer screening, especially as soon as sexual activity begins.

Keywords: cervical cancer, rural areas, Imo state, knowledge, attitude

Procedia PDF Downloads 34

Authors: Alexandre Daliberto Frugoli, Pedro Jose Gabriel Ferreira, Pedro Americo Frugoli, Lucio Leonardo, Thais Cavalheri Santos

Abstract:

Laboratory classes in Engineering courses are essential for students to be able to integrate theory with practical reality, by handling equipment and observing experiments. In the researches of physical phenomena, students can learn about the complexities of science. Over the past years, universities in developing countries have been reducing the course load of engineering courses, in accordance with cutting cost agendas. Quality education is the object of study for researchers and requires educators and educational administrators able to demonstrate that the institutions are able to provide great learning opportunities at reasonable costs. Didactic test benches are indispensable equipment in educational activities related to turbo hydraulic pumps and pumping facilities study, which have a high cost and require long class time due to measurements and equipment adjustment time. In order to overcome the aforementioned obstacles, aligned with the professional objectives of an engineer, GruPEFE - UNIP (Research Group in Physics Education for Engineering - Universidade Paulista) has developed a multi-purpose stand for the discipline of fluid mechanics which allows the study of velocity and flow meters, loads losses and pump association. In this work, results obtained by the association in series and in parallel of hydraulic pumps will be presented and discussed, mainly analyzing the repeatability of experimental procedures and their agreement with the theory. For the association in series two identical pumps were used, consisting of the connection of the discharge of a pump to the suction of the next one, allowing the fluid to receive the power of all machines in the association. The characteristic curve of the set is obtained from the curves of each of the pumps, by adding the heads corresponding to the same flow rates. The same pumps were associated in parallel. In this association, the discharge piping is common to the two machines together. The characteristic curve of the set was obtained by adding to each value of H (head height), the flow rates of each pump. For the tests, the input and output pressure of each pump were measured. For each set there were three sets of measurements, varying the flow rate in range from 6.0 to 8.5 m 3 / h. For the two associations, the results showed an excellent repeatability with variations of less than 10% between sets of measurements and also a good agreement with the theory. This variation agrees with the instrumental uncertainty. Thus, the results validate the use of the fluids bench designed for didactic purposes. As a future work, a digital acquisition system is being developed, using differential sensors of extremely low pressures (2 to 2000 Pa approximately) for the microcontroller Arduino.

Keywords: engineering education, fluid mechanics, hydrostatic pumps association, multi-purpose stand

Procedia PDF Downloads 220

Authors: Dong Zhao

Abstract:

Even though the recent claim of room temperature superconductivity by LK-99 was confirmed an unsuccessful attempt, this work reawakened people’s century striving to get applicable superconductors with Tc of room temperature or higher and under ambient pressure. One of the efforts was focusing on exploring the thorium salts. This is because certain thorium compounds revealed an unusual property of having both high electrical conductivity and diamagnetism or the so-called “coexistence of high electrical conductivity and diamagnetism.” It is well known that this property of the coexistence of high electrical conductivity and diamagnetism is held by superconductors because of the electron pairings. Consequently, the likelihood for these thorium compounds to have superconducting properties becomes great. However, as a surprise, these thorium salts possess this property at room temperature and atmosphere pressure. This gives rise to solid evidence for these thorium compounds to be room-temperature superconductors without a need for external pressure. Among these thorium compound superconductors claimed in that work, thorium di-iodide (ThI₂) is a unique one and has received comprehensive discussion. ThI₂ was synthesized and structurally analyzed by the single crystal diffraction method in the 1960s. Its special property of coexistence of high electrical conductivity and diamagnetism was revealed. Because of this unique property, a special molecular configuration was sketched. Except for an ordinary oxidation of +2 for the thorium cation, the thorium’s oxidation state in ThI₂ is +4. According to the experimental results, ThI₂‘s actual molecular configuration was determined as an unusual one of [Th4+(e-)2](I-)2. This means that the ThI₂ salt’s cation is composed of a [Th4+(e-)2]2+ cation core. In other words, the cation of ThI₂ is constructed by combining an oxidation state +4 of the thorium atom and a pair of electrons or an electron lone pair located on the thorium atom. This combination of the thorium atom and the electron lone pair leads to an oxidation state +2 for the [Th4+(e-)2]2+ cation core. This special construction of the thorium cation is very distinctive, which is believed to be the factor that grants ThI₂ the room temperature superconductivity. Actually, the key for ThI₂ to become a room-temperature superconductor is this characteristic electron lone pair residing on the thorium atom along with the formation of a network constructed by the thorium atoms. This network specializes in a way that allows the electron lone pairs to hop over it and, thus, to generate the supercurrent. This work will discuss, in detail, the special electrical and magnetic properties of ThI₂ as well as its structural features at ambient conditions. The exploration of how the electron pairing in combination with the structurally specialized network works together to bring ThI₂ into a superconducting state. From the experimental results, strong evidence has definitely pointed out that the ThI₂ should be a superconductor, at least at room temperature and under atmosphere pressure.

Keywords: co-existence of high electrical conductivity and diamagnetism, electron lone pair, room temperature superconductor, special molecular configuration of thorium di-iodide ThI₂

Procedia PDF Downloads 58

Authors: Abdelhafid Zenati, Mohamed Tadjine

Abstract:

The mathematical formulation of biomedical problems is an important phase to understand and predict the dynamic of the controlled population. In this paper we perform a stability analysis of a coupled model for healthy and cancerous cells dynamics in Acute Myeloid Leukemia, this represents our first aim. Second, we illustrate the effect of the interconnection between healthy and cancer cells. The PDE-based model is transformed to a nonlinear distributed state space model (delay system). For an equilibrium point of interest, necessary and sufficient conditions of global asymptotic stability are given. Thus, we came up to give necessary and sufficient conditions of global asymptotic stability of the origin and the healthy situation and control of the dynamics of normal hematopoietic stem cells and cancerous during myelode Acute leukemia. Simulation studies are given to illustrate the developed results.

Keywords: distributed delay, global stability, modelling, nonlinear models, PDE, state space

Procedia PDF Downloads 252

Authors: Ronit Chakraborty, Sugata Banerji

Abstract:

There has been a marked increase in the reported prevalence of Autism Spectrum Disorder (ASD) among children in the US over the past two decades. This research has analyzed the growth in state-level ASD prevalence against 45 different potentially explanatory factors, including socio-economic, demographic, healthcare, public policy, and political factors. The goal was to understand if these factors have adequate predictive power in modeling the differential growth in ASD prevalence across various states and if they do, which factors are the most influential. The key findings of this study include (1) the confirmation that the chosen feature set has considerable power in predicting the growth in ASD prevalence, (2) the identification of the most influential predictive factors, (3) given the nature of the most influential predictive variables, an indication that a considerable portion of the reported ASD prevalence differentials across states could be attributable to over and under diagnosis, and (4) identification of Florida as a key outlier state pointing to a potential under-diagnosis of ASD there.

Keywords: autism spectrum disorder, clustering, machine learning, predictive modeling

Procedia PDF Downloads 103