Search results for: uneven habitat shape
2258 Structural Characterization and Hot Deformation Behaviour of Al3Ni2/Al3Ni in-situ Core-shell intermetallic in Al-4Cu-Ni Composite
Authors: Ganesh V., Asit Kumar Khanra
Abstract:
An in-situ powder metallurgy technique was employed to create Ni-Al3Ni/Al3Ni2 core-shell-shaped aluminum-based intermetallic reinforced composites. The impact of Ni addition on the phase composition, microstructure, and mechanical characteristics of the Al-4Cu-xNi (x = 0, 2, 4, 6, 8, 10 wt.%) in relation to various sintering temperatures was investigated. Microstructure evolution was extensively examined using X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), and transmission electron microscopy (TEM) techniques. Initially, under sintering conditions, the formation of "Single Core-Shell" structures was observed, consisting of Ni as the core with Al3Ni2 intermetallic, whereas samples sintered at 620°C exhibited both "Single Core-Shell" and "Double Core-Shell" structures containing Al3Ni2 and Al3Ni intermetallics formed between the Al matrix and Ni reinforcements. The composite achieved a high compressive yield strength of 198.13 MPa and ultimate strength of 410.68 MPa, with 24% total elongation for the sample containing 10 wt.% Ni. Additionally, there was a substantial increase in hardness, reaching 124.21 HV, which is 2.4 times higher than that of the base aluminum. Nanoindentation studies showed hardness values of 1.54, 4.65, 21.01, 13.16, 5.52, 6.27, and 8.39GPa corresponding to α-Al matrix, Ni, Al3Ni2, Ni and Al3Ni2 interface, Al3Ni, and their respective interfaces. Even at 200°C, it retained 54% of its room temperature strength (90.51 MPa). To investigate the deformation behavior of the composite material, experiments were conducted at deformation temperatures ranging from 300°C to 500°C, with strain rates varying from 0.0001s-1 to 0.1s-1. A sine-hyperbolic constitutive equation was developed to characterize the flow stress of the composite, which exhibited a significantly higher hot deformation activation energy of 231.44 kJ/mol compared to the self-diffusion of pure aluminum. The formation of Al2Cu intermetallics at grain boundaries and Al3Ni2/Al3Ni within the matrix hindered dislocation movement, leading to an increase in activation energy, which might have an adverse effect on high-temperature applications. Two models, the Strain-compensated Arrhenius model and the Artificial Neural Network (ANN) model, were developed to predict the composite's flow behavior. The ANN model outperformed the Strain-compensated Arrhenius model with a lower average absolute relative error of 2.266%, a smaller root means square error of 1.2488 MPa, and a higher correlation coefficient of 0.9997. Processing maps revealed that the optimal hot working conditions for the composite were in the temperature range of 420-500°C and strain rates between 0.0001s-1 and 0.001s-1. The changes in the composite microstructure were successfully correlated with the theory of processing maps, considering temperature and strain rate conditions. The uneven distribution in the shape and size of Core-shell/Al3Ni intermetallic compounds influenced the flow stress curves, leading to Dynamic Recrystallization (DRX), followed by partial Dynamic Recovery (DRV), and ultimately strain hardening. This composite material shows promise for applications in the automobile and aerospace industries.Keywords: core-shell structure, hot deformation, intermetallic compounds, powder metallurgy
Procedia PDF Downloads 222257 Free Shape Optimisation of Cold Formed Steel Sections
Authors: Mina Mortazavi, Pezhman Sharafi
Abstract:
Cold-formed steel sections are popular construction materials as structural or non-structural elements. The objective of this paper is to propose an optimisation method for open cross sections targeting the maximum nominal axial strength. The cross sections considered in the optimisation process should all meet a determined critical global buckling load to be considered as a candidate for optimisation process. The maximum dimensions of the cross section are fixed and limited into a predefined rectangular area. The optimisation process is repeated for different available coil thicknesses of 1 mm, 2.5 mm and 3 mm to determine the optimum thickness according to the cross section buckling behaviour. A simple-simple boundary is assumed as end conditions. The number of folds is limited to 20 folds to prevent extra complicated sections. The global buckling load is considered as Euler load and is determined according to the moment of inertia of the cross-section with a constant length. The critical buckling loads are obtained using Finite Strip Method. The results of the optimisation analysis are provided, and the optimum cross-section within the considered range is determined.Keywords: shape optimisation, buckling, cold formed steel, finite strip method
Procedia PDF Downloads 3992256 Control of an Asymmetrical Design of a Pneumatically Actuated Ambidextrous Robot Hand
Authors: Emre Akyürek, Anthony Huynh, Tatiana Kalganova
Abstract:
The Ambidextrous Robot Hand is a robotic device with the purpose to mimic either the gestures of a right or a left hand. The symmetrical behavior of its fingers allows them to bend in one way or another keeping a compliant and anthropomorphic shape. However, in addition to gestures they can reproduce on both sides, an asymmetrical mechanical design with a three tendons routing has been engineered to reduce the number of actuators. As a consequence, control algorithms must be adapted to drive efficiently the ambidextrous fingers from one position to another and to include grasping features. These movements are controlled by pneumatic muscles, which are nonlinear actuators. As their elasticity constantly varies when they are under actuation, the length of pneumatic muscles and the force they provide may differ for a same value of pressurized air. The control algorithms introduced in this paper take both the fingers asymmetrical design and the pneumatic muscles nonlinearity into account to permit an accurate control of the Ambidextrous Robot Hand. The finger motion is achieved by combining a classic PID controller with a phase plane switching control that turns the gain constants into dynamic values. The grasping ability is made possible because of a sliding mode control that makes the fingers adapt to the shape of an object before strengthening their positions.Keywords: ambidextrous hand, intelligent algorithms, nonlinear actuators, pneumatic muscles, robotics, sliding control
Procedia PDF Downloads 2972255 A Vertical-Axis Unidirectional Rotor with Nested Blades for Wave Energy Conversion
Authors: Yingchen Yang
Abstract:
In the present work, development of a new vertical-axis unidirectional wave rotor is reported. The wave rotor is a key component of a wave energy converter (WEC), which harvests energy from ocean waves. Differing from the huge majority of WEC designs that perform reciprocating motions (heaving up and down, swaying back and forth, etc.), our wave rotor performs unidirectional rotation about a vertical axis when directly exposed in waves. The unidirectional feature of the rotor makes the rotor respond well in a wide range of the wave frequency. The vertical axis arrangement of the rotor makes the rotor insensitive to the wave propagation direction. The rotor employs blades with a cross-section in an airfoil shape and a span curled into a semi-oval shape. Two sets of blades, with one nested inside the other, constitute the rotor. In waves, water particles perform an omnidirectional motion that constantly changes in both spatial and temporal domains. The blade nesting permits a compact rotor configuration that ‘sees’ a relatively uniform local flow in the spatial domain. The rotor was experimentally tested in simulated waves in a wave flume under various conditions. The testing results show a promising unidirectional rotor that is capable of extracting energy from waves at a capture width ratio of 0.08 to 0.15, depending on detailed wave conditions.Keywords: unidirectional, vertical axis, wave energy converter, wave rotor
Procedia PDF Downloads 2372254 Management and Conservation of Crop Biodiversity in Karnali Mountains of Nepal
Authors: Chhabi Paudel
Abstract:
The food and nutrition security of the people of the mountain of Karnali province of Nepal is dependent on traditional crop biodiversity. The altitude range of the study area is 1800 meters to 2700 meters above sea level. The climate is temperate to alpine. Farmers are adopting subsistent oriented diversified farming systems and selected crop species, cultivars, and local production systems by their own long adaptation mechanism. The major crop species are finger millet, proso millet, foxtail millet, potato, barley, wheat, mountain rice, buckwheat, Amaranths, medicinal plants, and many vegetable species. The genetic and varietal diversity of those underutilized indigenous crops is also very high, which has sustained farming even in uneven climatic events. Biodiversity provides production synergy, inputs, and other agro-ecological services for self-sustainability. But increase in human population and urban accessibility are seen as threats to biodiversity conservation. So integrated conservation measures are suggested, including agro-tourism and other monetary benefits to the farmers who conserve the local biodiversity.Keywords: crop biodiversity, climate change, in-situ conservation, resilience, sustainability, agrotourism
Procedia PDF Downloads 1012253 Vacancy-Driven Magnetism of GdMnO₃
Authors: Matúš Mihalik, Martin Vavra, Kornel Csach, Marián Mihalik
Abstract:
GdMnO₃ belongs to orthorhombically distorted, GdFeO₃-type family of perovskite compounds. These compounds are naturally vacant and the amount of vacancies depend on the sample preparation conditions. Our GdMnO₃ samples were prepared by float zone method and the vacancies were controlled using an air, Ar and O₂ preparation atmosphere. The highest amount of vacancies was found for sample prepared in Ar atmosphere, while the sample prepared in O₂ was observed to be almost vacancy-free. The magnetic measurements indicate that the preparation atmosphere has no impact on Néel temperature (TN ~ 42 K), however, it has strong impact on the incommensurate antiferromagnetic (IC) to canted A-type weak ferromagnetic (AWF) phase transition at T1: T1 = 23.4 K; 18 K and 6.7 K for samples prepared in Ar; air and O₂ atmosphere; respectively. The hysteresis loop measured at 2 K has a butterfly-type shape with the remnant magnetization (Mr) of 0.6 µB/f.u. for Ar and air sample, while Mr = 0.3 µB/f.u. for O₂ sample. The shape of the hysteresis loop depends on the preparation atmosphere in magnetic fields up to 1.5 T, but is independent for higher magnetic fields. The coercive field of less than 0.06 T and the maximum magnetic moment of 6 µB/f.u. at magnetic field µ0H = 7 T do not depend on the preparation atmosphere. All these findings indicate that only AWF phase of GdMnO₃ compound is directly affected by the vacancies in the system, while IC phase and the field induced ferroelectric phase are not affected.Keywords: magnetism, perovskites, sample preparation, magnetic phase transition
Procedia PDF Downloads 1112252 Electrokinetics and Stability of Solder Powders in Aqueous Media
Authors: Terence Lucero F. Menor, Manolo G. Mena, Herman D. Mendoza
Abstract:
Solder pastes are widely used in creating mechanical, thermal and electrical connection between electronic components. Continued miniaturization of consumer electronics drives manufacturers to achieve smaller, lighter, and faster electronic packages at low cost. This faces them to the difficult challenge of dispensing solder pastes in extremely precise and repeatable manner. The most common problem in solder paste dispensing is the clogging of dispensers which results from agglomeration and settling of solder powders leading to increase on the effective particle size and uneven distribution of particles in the mixture. In this work, microelectrophoresis was employed to investigate the effect of pH and KNO₃ concentration on the electrokinetic behavior and stability of SAC305, PbSn5Ag2.5 and Sn powders in aqueous media. Results revealed that the electrokinetic behavior of the three types of solder powders are similar, which was attributed to high SnO₂ content on the surface of the particles. Electrokinetic measurements showed that the zeta potentials of the solder powders are highly dependent on pH and KNO₃ concentration with isoelectric points ranging from 3.5 to 5.5. Results were verified using stability tests.Keywords: electrokinetic behavior, isoelectric point, solder powder, stability, surface analysis
Procedia PDF Downloads 2312251 Butterfly Diversity along Urban-Rural Gradient in Kolkata, India
Authors: Sushmita Chaudhuri, Parthiba Basu
Abstract:
Urbanization leads to habitat degradation and is responsible for the fast disappearance of native butterfly species. Random sampling of rural, suburban and urban sites in an around Kolkata metropolis revealed the presence of 28 species of butterfly belonging to 5 different families in winter (February-March). Butterfly diversity, species richness and abundance decreased with increase in urbanization. Psyche (Leptosia nina of family Pieridae) was the most predominant butterfly species found everywhere in Kolkata during the winter period. The most dominant family was Nymphalidae (11species), followed by Pieridae (6 species), Lycaenidae (5 species), Papilionidae (4 species) and Hesperiidae (2 species). The rural and suburban sites had butterfly species that were unique to those sites. Vegetation cover and flowering shrub density were significantly related to butterfly diversity.Keywords: butterfly, Kolkata metropolis, Shannon-Weiner diversity index, species diversity
Procedia PDF Downloads 2902250 Illegal Anthropogenic Activity Drives Large Mammal Population Declines in an African Protected Area
Authors: Oluseun A. Akinsorotan, Louise K. Gentle, Md. Mofakkarul Islam, Richard W. Yarnell
Abstract:
High levels of anthropogenic activity such as habitat destruction, poaching and encroachment into natural habitat have resulted in significant global wildlife declines. In order to protect wildlife, many protected areas such as national parks have been created. However, it is argued that many protected areas are only protected in name and are often exposed to continued, and often illegal, anthropogenic pressure. In West African protected areas, declines of large mammals have been documented between 1962 and 2008. This study aimed to produce occupancy estimates of the remaining large mammal fauna in the third largest National Park in Nigeria, Old Oyo, and to compare the estimates with historic estimates while also attempting to quantify levels of illegal anthropogenic activity using a multi-disciplinary approach. Large mammal populations and levels of illegal anthropogenic activity were assessed using empirical field data (camera trapping and transect surveys) in combination with data from questionnaires completed by local villagers and park rangers. Four of the historically recorded species in the park, lion (Panthera leo), hunting dog (Lycaon pictus), elephant (Loxodonta africana) and buffalo (Syncerus caffer) were not detected during field studies nor were they reported by respondents. In addition, occupancy estimates of hunters and illegal grazers were higher than the majority of large mammal species inside the park. This finding was reinforced by responses from the villagers and rangers who’s perception was that large mammal densities in the park were declining, and that a large proportion of the local people were entering the park to hunt wild animals and graze their domestic livestock. Our findings also suggest that widespread poverty and a lack of alternative livelihood opportunities, culture of consuming bushmeat, lack of education and awareness of the value of protected areas, and weak law enforcement are some of the reasons for the illegal activity. Law enforcement authorities were often constrained by insufficient on-site personnel and a lack of modern equipment and infrastructure to deter illegal activities. We conclude that there is a need to address the issue of illegal hunting and livestock grazing, via provision of alternative livelihoods, in combination with community outreach programmes that aim to improve conservation education and awareness and develop the capacity of the conservation authorities in order to achieve conservation goals. Our findings have implications for the conservation management of all protected areas that are available for exploitation by local communities.Keywords: camera trapping, conservation, extirpation, illegal grazing, large mammals, national park, occupancy estimates, poaching
Procedia PDF Downloads 2962249 Radial Fuel Injection Computational Fluid Dynamics Model for a Compression Ignition Two-Stroke Opposed Piston Engine
Authors: Tytus Tulwin, Rafal Sochaczewski, Ksenia Siadkowska
Abstract:
Designing a new engine requires a large number of different cases to be considered. Especially different injector parameters and combustion chamber geometries. This is essential when developing an engine with unconventional build – compression ignition, two-stroke operating with direct side injection. Computational Fluid Dynamics modelling allows to test those different conditions and seek for the best conditions with correct combustion. This research presents the combustion results for different injector and combustion chamber cases. The shape of combustion chamber is different than for conventional engines as it requires side injection. This completely changes the optimal shape for the given condition compared to standard automotive heart shaped combustion chamber. Because the injection is not symmetrical there is a strong influence of cylinder swirl and piston motion on the injected fuel stream. The results present the fuel injection phenomena allowing to predict the right injection parameters for a maximum combustion efficiency and minimum piston heat loads. Acknowledgement: This work has been realized in the cooperation with The Construction Office of WSK "PZL-KALISZ" S.A." and is part of Grant Agreement No. POIR.01.02.00-00-0002/15 financed by the Polish National Centre for Research and Development.Keywords: CFD, combustion, injection, opposed piston
Procedia PDF Downloads 2752248 The Molecular Characteristic of Heliotropium digynum in Saudi Arabia by Inter-Simple Sequence Repeat (ISSR) Analysis
Authors: Mona Alwhibi, Najat Bukhary
Abstract:
Heliotropium digynum, a member of Boraginaceae family, the growth of the plant, as well as its size, length of inflorescence, and speed of development depends on the amount of rain in its habitat. In this study, we studied the applicability of inter-simple sequence repeat (ISSR) polymorphism in Heliotropium digynum in a different region of Saudi Arabia. We found that. ISSR analysis using 15 primers were used for ISSR-PCR optimization trials, five primers (UBC810, UBC811, UBC818, UBC834, and UBC849) which gave the best amplification results produced a total of 43 polymorphic bands. The number of polymorphic loci was 20 and the percentage of polymorphism was 90.47%. The similarity result indicates the presence of a high-level genetic diversity between populations and a dendrogram constructed by UPGMA method.Keywords: genetic differentiation, genetic diversity, Heliotropium digynum, ISSR
Procedia PDF Downloads 4852247 Characteristics of Elastic Tracked-Crawler Based on Worm-Rack Mechanism
Authors: Jun-ya Nagase
Abstract:
There are many pipes such as a water pipe and a gas pipe in a chemical plant and house. It is possible to prevent accidents by these inspections. However, many pipes are very narrow and it is difficult for people to inspect directly. Therefore, development of a robot that can move in narrow pipe is necessary. A wheel movement type robot, a snake-like robot and a multi-leg robot are all described in the relevant literature as pipe inspection robots that are currently studied. Among them, the tracked crawler robot can travel by traversing uneven ground flexibly with a crawler belt attached firmly to the ground surface. Although conventional crawler robots have high efficiency and/or high ground-covering ability, they require a comparatively large space to move. In this study, a cylindrical crawler robot based on worm-rack mechanism, which does not need large space to move and which has high ground-covering ability, is proposed. Experiments have demonstrated smooth operation and a forward movement of the robot by application of voltage to the motor. In addition, performance tests show that it can propel itself in confined spaces. This paper reports the structure, drive mechanism, prototype, and experimental evaluation.Keywords: tracked-crawler, pipe inspection robot, worm-rack mechanism, amoeba locomotion
Procedia PDF Downloads 4312246 The Role of China’s Rural Policies on the Changing the Rural Area in China: Changfu Village(China) Case
Authors: Zheng Lulin, Xiong Guoping
Abstract:
In recent years, agriculture, rural development, and peasants are among the top concerns and priorities of the Chinese Government. Several related issues have been paid many attentions by academic communities, including the impacts of corresponding policies on the rural villages, the mechanisms of these impacts, and the future development of rural society. However, most of the researchers focus on single rural policy instead of integral rural policy system. Hence, this dissertation focused on the mechanisms of policies’ influence on rural changes through a case study from Changfu Village in central Guangxi Province, China, to propose the optimized suggestions for rural development. Forty-three relevant pivotal policies of significant influence on rural development are summarized from literature and documents, covering five aspects of agricultural production, rural living security, open rural markets, rural household registration systems, and farmland transferring. Besides, having been live in this area for more than 20 years, researchers obtain the basic information about changing the social connection between citizens and villagers, the habitat of villagers by years of informal interviews. Furthermore, more than 200 questionnaires are given to villagers to analyze the changing of their personal and family information. The summary of rural policies revealed that the development trend of public rural policies followed the U-shape curve and these policies are characterized by economic intentions and operative economy. Report of questionnaires and interviews show that the development of rural economy was promoted greatly by public policies. Firstly, Social communication and rural culture were affected to a certain extent. Secondly, the educational level of rural individuals was significantly enhanced, whereas the quality of population had limited progress. Finally, the freedom of occupational choice for rural individuals into cities was greater than before, but still restricted by the class solidification of social background, resulting in more obstacles for rural individuals to settle down in cities. From what we discuss about, we may reach the conclusion on several perspectives: Firstly, the impact of the rural policies has a significant role in promoting the economy development of the rural area. However, separations between rural and urban area are still a major problem since rural policy contributed little to improve the rural population quality. Therefore, in the future, providing high quality educational facilities including teachers, libraries, and opportunities of broadening their knowledge base are key issues of future rural policy. Secondly, the development of rural economy would be a lack of driving force for further improvement owning to the fact that working hard couldn’t get more improvement. In the future, public policies should support the rural development of culture, technology, and personal qualities to create favorable social environment for the free increase of rural population.Keywords: changing of rural area, rural development of China, rural policy, social environment
Procedia PDF Downloads 4312245 Strategies Used by the Saffron Producers of Taliouine (Morocco) to Adapt to Climate Change
Authors: Aziz Larbi, Widad Sadok
Abstract:
In Morocco, the mountainous regions extend over about 26% of the national territory where 30% of the total population live. They contain opportunities for agriculture, forestry, pastureland and mining. The production systems in these zones are characterised by crop diversification. However, these areas have become vulnerable to the effects of climate change. To understand these effects in relation to the population living in these areas, a study was carried out in the zone of Taliouine, in the Anti-Atlas. The vulnerability of crop productions to climate change was analysed and the different ways of adaptation adopted by farmers were identified. The work was done on saffron, the most profitable crop in the target area even though it requires much water. Our results show that the majority of the farmers surveyed had noticed variations in the climate of the region: irregularity of precipitation leading to a decrease in quantity and an uneven distribution throughout the year; rise in temperature; reduction in the cold period and less snow. These variations had impacts on the cropping system of saffron and its productivity. To cope with these effects, the farmers adopted various strategies: better management and use of water; diversification of agricultural activities; increase in the contribution of non-agricultural activities to their gross income; and seasonal migration.Keywords: climate change, Taliouine, saffron, perceptions, adaptation strategies
Procedia PDF Downloads 612244 The Influence of Fiber Volume Fraction on Thermal Conductivity of Pultruded Profile
Authors: V. Lukášová, P. Peukert, V. Votrubec
Abstract:
Thermal conductivity in the x, y and z-directions was measured on a pultruded profile that was manufactured by the technology of pulling from glass fibers and a polyester matrix. The results of measurements of thermal conductivity showed considerable variability in different directions. The caused variability in thermal conductivity was expected due fraction variations. The cross-section of the pultruded profile was scanned. An image analysis illustrated an uneven distribution of the fibers and the matrix in the cross-section. The distribution of these inequalities was processed into a Voronoi diagram in the observed area of the pultruded profile cross-section. In order to verify whether the variation of the fiber volume fraction in the pultruded profile can affect its thermal conductivity, the numerical simulations in the ANSYS Fluent were performed. The simulation was based on the geometry reconstructed from image analysis. The aim is to quantify thermal conductivity numerically. Above all, images with different volume fractions were chosen. The results of the measured thermal conductivity were compared with the calculated thermal conductivity. The evaluated data proved a strong correlation between volume fraction and thermal conductivity of the pultruded profile. Based on presented results, a modification of production technology may be proposed.Keywords: pultrusion profile, volume fraction, thermal conductivity, numerical simulation
Procedia PDF Downloads 3462243 Thrust Enhancement on a Two Dimensional Elliptic Airfoil in a Forward Flight
Authors: S. M. Dash, K. B. Lua, T. T. Lim
Abstract:
This paper presents results of numerical and experimental studies on a two-dimensional (2D) flapping elliptic airfoil in a forward flight condition at Reynolds number of 5000. The study is motivated from an earlier investigation which shows that the deterioration in thrust performance of a sinusoidal heaving and pitching 2D (NACA0012) airfoil at high flapping frequency can be recovered by changing the effective angle of attack profile to square wave, sawtooth, or cosine wave shape. To better understand why such modifications lead to superior thrust performance, we take a closer look at the transient aerodynamic force behavior of an airfoil when the effective angle of attack profile changes gradually from a generic smooth trapezoidal profile to a sinusoid shape by modifying the base length of the trapezoid. The choice of using a smooth trapezoidal profile is to avoid the infinite acceleration condition encountered in the square wave profile. Our results show that the enhancement in the time-averaged thrust performance at high flapping frequency can be attributed to the delay and reduction in the drag producing valley region in the transient thrust force coefficient when the effective angle of attack profile changes from sinusoidal to trapezoidal.Keywords: two-dimensional flapping airfoil, thrust performance, effective angle of attack, CFD, experiments
Procedia PDF Downloads 3592242 Current Drainage Attack Correction via Adjusting the Attacking Saw-Function Asymmetry
Authors: Yuri Boiko, Iluju Kiringa, Tet Yeap
Abstract:
Current drainage attack suggested previously is further studied in regular settings of closed-loop controlled Brushless DC (BLDC) motor with Kalman filter in the feedback loop. Modeling and simulation experiments are conducted in a Matlab environment, implementing the closed-loop control model of BLDC motor operation in position sensorless mode under Kalman filter drive. The current increase in the motor windings is caused by the controller (p-controller in our case) affected by false data injection of substitution of the angular velocity estimates with distorted values. Operation of multiplication to distortion coefficient, values of which are taken from the distortion function synchronized in its periodicity with the rotor’s position change. A saw function with a triangular tooth shape is studied herewith for the purpose of carrying out the bias injection with current drainage consequences. The specific focus here is on how the asymmetry of the tooth in the saw function affects the flow of current drainage. The purpose is two-fold: (i) to produce and collect the signature of an asymmetric saw in the attack for further pattern recognition process, and (ii) to determine conditions of improving stealthiness of such attack via regulating asymmetry in saw function used. It is found that modification of the symmetry in the saw tooth affects the periodicity of current drainage modulation. Specifically, the modulation frequency of the drained current for a fully asymmetric tooth shape coincides with the saw function modulation frequency itself. Increasing the symmetry parameter for the triangle tooth shape leads to an increase in the modulation frequency for the drained current. Moreover, such frequency reaches the switching frequency of the motor windings for fully symmetric triangular shapes, thus becoming undetectable and improving the stealthiness of the attack. Therefore, the collected signatures of the attack can serve for attack parameter identification via the pattern recognition route.Keywords: bias injection attack, Kalman filter, BLDC motor, control system, closed loop, P-controller, PID-controller, current drainage, saw-function, asymmetry
Procedia PDF Downloads 812241 Preliminary Study of Fermented Pickle of Tabah Bamboo Shoot: Gigantochloa nigrociliata (Buese) Kurz
Authors: Luh Putu T. Darmayanti, A. A. Duwipayana, I. Nengah K. Putra, Nyoman S. Antara
Abstract:
Tabah Bamboo (Gigantochloa nigrociliata (Buese) Kurz) is the indigenous bamboo species which grows in District of Pupuan, Tabanan at Province of Bali. Compared to the others, this shoot has low concentration of hydrocyanide acid (HCN). However, as found for almost of bamboo shoot, its seasonal availability, perishable in nature, and short-lived. This study aimed to gather information about total of lactic acid bacteria (LAB), pH, total acidity, HCN content, detection of LAB’s type involved during fermentation, and organic acids’ profiles of fermented pickles of Tabah bamboo shoot. The pickle was made by natural fermentation with 6 % salt concentration and fermentation conducted for 13 days. The result showed during the fermentation time, in the fourth day we found LAB’s number was highest as much as 72 x 107 CFU/ml and the lowest pH was 3.09. We also found decreasing in HCN from 37.8 ppm at the beginning to 20.52 ppm at the end of fermentation process. The total number of indigenous LAB isolated from the pickle are 48 strains we found 18 out of these had rod shape. For the preliminary study, all of the LAB with rod shape were detected by PCR as member of Lactobacillus spp., in which 17 strains detected as L. plantarum. The organic acids detected during the fermentation were lactic acid with the highest concentration was 0.0546 g/100 g and small amount of acetic acid.Keywords: fermentation, LAB, pickle, Tabah Bamboo shoot
Procedia PDF Downloads 3452240 International Solar Alliance: A Case for Indian Solar Diplomacy
Authors: Swadha Singh
Abstract:
International Solar Alliance is the foremost treaty-based global organization concerned with tapping the potential of sun-abundant nations between the Tropics of Cancer and Capricorn and enables co-operation among them. As a founding member of the International Solar Alliance, India exhibits its positioning as an upcoming leader in clean energy. India has set ambitious goals and targets to expand the share of solar in its energy mix and is playing a proactive role both at the regional and global levels. ISA aims to serve multiple goals- bring about scale commercialization of solar power, boost domestic manufacturing, and leverage solar diplomacy in African countries, amongst others. Against this backdrop, this paper attempts to examine the ways in which ISA as an intergovernmental organization under Indian leadership can leverage the cause of clean energy (solar) diplomacy and effectively shape partnerships and collaborations with other developing countries in terms of sharing solar technology, capacity building, risk mitigation, mobilizing financial investment and providing an aggregate market. A more specific focus of ISA is on the developing countries, which in the absence of a collective, are constrained by technology and capital scarcity, despite being naturally endowed with solar resources. Solar rich but finance-constrained economies face political risk, foreign exchange risk, and off-taker risk. Scholars argue that aligning India’s climate change discourse and growth prospects in its engagements, collaborations, and partnerships at the bilateral, multilateral and regional level can help promote trade, attract investments, and promote resilient energy transition both in India and in partner countries. For developing countries, coming together in an action-oriented way on issues of climate and clean energy is particularly important since it is developing and underdeveloped countries that face multiple and coalescing challenges such as the adverse impact of climate change, uneven and low access to reliable energy, and pressing employment needs. Investing in green recovery is agreed to be an assured way to create resilient value chains, create sustainable livelihoods, and help mitigate climate threats. If India is able to ‘green its growth’ process, it holds the potential to emerge as a climate leader internationally. It can use its experience in the renewable sector to guide other developing countries in balancing multiple similar objectives of development, energy security, and sustainability. The challenges underlying solar expansion in India have lessons to offer other developing countries, giving India an opportunity to assume a leadership role in solar diplomacy and expand its geopolitical influence through inter-governmental organizations such as ISA. It is noted that India has limited capacity to directly provide financial funds and support and is not a leading manufacturer of cheap solar equipment, as does China; however, India can nonetheless leverage its large domestic market to scale up the commercialization of solar power and offer insights and learnings to similarly placed abundant solar countries. The paper examines the potential of and limits placed on India’s solar diplomacy.Keywords: climate diplomacy, energy security, solar diplomacy, renewable energy
Procedia PDF Downloads 1202239 Assessment of Water Resources and Inculcation of Controlled Water Consumption System
Authors: Vakhtang Geladze, Nana Bolashvili, Tamazi Karalashvili, Nino Machavariani, Vajha Neidze, Nana Kvirkvelia, Tamar Chichinadze
Abstract:
Deficiency of fresh water is a vital global problem today. It must be taken into consideration that in the nearest future fresh water crisis will become even more acute owing to the global climate warming and fast desertification processes in the world. Georgia has signed the association agreement with Euro Union last year where the priority spheres of cooperation are the management of water resources, development of trans-boundary approach to the problem and active participation in the “Euro Union water initiative” component of “the East Europe, Caucasus and the Central Asia”. Fresh water resources are the main natural wealth of Georgia. According to the average water layer height, Georgia is behind such European countries only as Norway, Switzerland and Austria. The annual average water provision of Georgia is 4-8 times higher than in its neighbor countries Armenia and Azerbaijan. Despite abundant water resources in Georgia, there is considerable discrepancy between their volume and use in some regions because of the uneven territorial distribution. In the East Georgia, water supply of the territory and population is four times less than in the West Georgia.Keywords: GIS, water consumption, water management, water resources
Procedia PDF Downloads 4192238 Unraveling the Phonosignological Foundations of Human Language and Semantic Analysis of Linguistic Elements in Cross-Cultural Contexts
Authors: Mahmudjon Kuchkarov, Marufjon Kuchkarov, Mukhayyo Sobirjanova
Abstract:
The origins of human language remain a profound scientific mystery, characterized by speculative theories often lacking empirical support. This study presents findings that may illuminate the genesis of human language, emphasizing its roots in natural, systematic, and repetitive sound patterns. Also, this paper presents the phonosignological and semantic analysis of linguistic elements across various languages and cultures. By utilizing the principles of the "Human Language" theory, we analyze the symbolic, phonetic, and semantic characteristics of elements such as "A", "L", "I", "F", and "四" (pronounced /si/ in Chinese and /shi/ in Japanese). Our findings reveal that natural sounds and their symbolic representations form the foundation of language, with significant implications for understanding religious and secular myths. This paper explores the intricate relationships between these elements and their cultural connotations, particularly focusing on the concept of "descent" in the context of the phonetic sequence "A, L, I, F," and the symbolic associations of the number four with death.Keywords: empirical research, human language, phonosignology, semantics, sound patterns, symbolism, body shape, body language, coding, Latin alphabet, merging method, natural sound, origin of language, pairing, phonetics, sound and shape production, word origin, word semantic
Procedia PDF Downloads 392237 Methods for Early Detection of Invasive Plant Species: A Case Study of Hueston Woods State Nature Preserve
Authors: Suzanne Zazycki, Bamidele Osamika, Heather Craska, Kaelyn Conaway, Reena Murphy, Stephanie Spence
Abstract:
Invasive Plant Species (IPS) are an important component of effective preservation and conservation of natural lands management. IPS are non-native plants which can aggressively encroach upon native species and pose a significant threat to the ecology, public health, and social welfare of a community. The presence of IPS in U.S. nature preserves has caused economic costs, which has estimated to exceed $26 billion a year. While different methods have been identified to control IPS, few methods have been recognized for early detection of IPS. This study examined identified methods for early detection of IPS in Hueston Woods State Nature Preserve. Mixed methods research design was adopted in this four-phased study. The first phase entailed data gathering, the phase described the characteristics and qualities of IPS and the importance of early detection (ED). The second phase explored ED methods, Geographic Information Systems (GIS) and Citizen Science were discovered as ED methods for IPS. The third phase of the study involved the creation of hotspot maps to identify likely areas for IPS growth. While the fourth phase involved testing and evaluating mobile applications that can support the efforts of citizen scientists in IPS detection. Literature reviews were conducted on IPS and ED methods, and four regional experts from ODNR and Miami University were interviewed. A questionnaire was used to gather information about ED methods used across the state. The findings revealed that geospatial methods, including Unmanned Aerial Vehicles (UAVs), Multispectral Satellites (MSS), and Normalized Difference Vegetation Index (NDVI), are not feasible for early detection of IPS, as they require GIS expertise, are still an emerging technology, and are not suitable for every habitat for the ED of IPS. Therefore, Other ED methods options were explored, which include predicting areas where IPS will grow, which can be done through monitoring areas that are like the species’ native habitat. Through literature review and interviews, IPS are known to grow in frequently disturbed areas such as along trails, shorelines, and streambanks. The research team called these areas “hotspots” and created maps of these hotspots specifically for HW NP to support and narrow the efforts of citizen scientists and staff in the ED of IPS. The results further showed that utilizing citizen scientists in the ED of IPS is feasible, especially through single day events or passive monitoring challenges. The study concluded that the creation of hotspot maps to direct the efforts of citizen scientists are effective for the early detection of IPS. Several recommendations were made, among which is the creation of hotspot maps to narrow the ED efforts as citizen scientists continues to work in the preserves and utilize citizen science volunteers to identify and record emerging IPS.Keywords: early detection, hueston woods state nature preserve, invasive plant species, hotspots
Procedia PDF Downloads 1072236 Flexural Behavior of Composite Hybrid Beam Models Combining Steel Inverted T-Section and RC Flange
Authors: Abdul Qader Melhem, Hacene Badache
Abstract:
This paper deals with the theoretical and experimental study of shear connection via simple steel reinforcement shear connectors, which are steel reinforcing bars bent into L-shapes, instead of commonly used headed studs. This suggested L-shape connectors are readily available construction material in steel reinforcement. The composite section, therefore, consists of steel inverted T-section being embedded within a lightly reinforced concrete flange at the top slab as a unit. It should be noted that the cross section of these composite models involves steel inverted T-beam, replacing the steel top flange of a standard commonly employed I-beam section. The paper concentrates on the elastic and elastic-plastic behavior of these composite models. Failure modes either by cracking of concrete or shear connection be investigated in details. Elastic and elastoplastic formulas of the composite model have been computed for different locations of NA. Deflection formula has been derived, its value was close to the test value. With a supportive designing curve, this curve is valuable for both designing engineers and researchers. Finally, suggested designing curves and valuable equations will be presented. A check is made between theoretical and experimental outcomes.Keywords: composite, elastic-plastic, failure, inverted T-section, L-Shape connectors
Procedia PDF Downloads 2282235 Numerical Investigation of Hot Oil Velocity Effect on Force Heat Convection and Impact of Wind Velocity on Convection Heat Transfer in Receiver Tube of Parabolic Trough Collector System
Authors: O. Afshar
Abstract:
A solar receiver is designed for operation under extremely uneven heat flux distribution, cyclic weather, and cloud transient cycle conditions, which can include large thermal stress and even receiver failure. In this study, the effect of different oil velocity on convection coefficient factor and impact of wind velocity on local Nusselt number by Finite Volume Method will be analyzed. This study is organized to give an overview of the numerical modeling using a MATLAB software, as an accurate, time efficient and economical way of analyzing the heat transfer trends over stationary receiver tube for different Reynolds number. The results reveal when oil velocity is below 0.33m/s, the value of convection coefficient is negligible at low temperature. The numerical graphs indicate that when oil velocity increases up to 1.2 m/s, heat convection coefficient increases significantly. In fact, a reduction in oil velocity causes a reduction in heat conduction through the glass envelope. In addition, the different local Nusselt number is reduced when the wind blows toward the concave side of the collector and it has a significant effect on heat losses reduction through the glass envelope.Keywords: receiver tube, heat convection, heat conduction, Nusselt number
Procedia PDF Downloads 3562234 Development of Equivalent Inelastic Springs to Model C-Devices
Authors: Oday Al-Mamoori, J. Enrique Martinez-Rueda
Abstract:
'C' shape yielding devices (C-devices) are effective tools for introducing supplemental sources of energy dissipation by hysteresis. Studies have shown that C-devices made of mild steel can be successfully applied as integral parts of seismic retrofitting schemes. However, explicit modelling of these devices can become cumbersome, expensive and time consuming. The device under study in this article has been previously used in non-invasive dissipative bracing for seismic retrofitting. The device is cut from a mild steel plate and has an overall shape that resembles that of a rectangular portal frame with circular interior corner transitions to avoid stress concentration and to control the extension of the dissipative region of the device. A number of inelastic finite element (FE) analyses using either inelastic 2D plane stress elements or inelastic fibre frame elements are reported and used to calibrate a 1D equivalent inelastic spring model that effectively reproduces the cyclic response of the device. The more elaborate FE model accounts for the frictional forces developed between the steel plate and the bolts used to connect the C-device to structural members. FE results also allow the visualization of the inelastic regions of the device where energy dissipation is expected to occur. FE analysis results are in a good agreement with experimental observations.Keywords: C-device, equivalent nonlinear spring, FE analyses, reversed cyclic tests
Procedia PDF Downloads 1522233 Calculation of A Sustainable Quota Harvesting of Long-tailed Macaque (Macaca fascicularis Raffles) in Their Natural Habitats
Authors: Yanto Santosa, Dede Aulia Rahman, Cory Wulan, Abdul Haris Mustari
Abstract:
The global demand for long-tailed macaques for medical experimentation has continued to increase. Fulfillment of Indonesian export demands has been mostly from natural habitats, based on a harvesting quota. This quota has been determined according to the total catch for a given year, and not based on consideration of any demographic parameters or physical environmental factors with regard to the animal; hence threatening the sustainability of the various populations. It is therefore necessary to formulate a method for calculating a sustainable harvesting quota, based on population parameters in natural habitats. Considering the possibility of variations in habitat characteristics and population parameters, a time series observation of demographic and physical/biotic parameters, in various habitats, was performed on 13 groups of long-tailed macaques, distributed throughout the West Java, Lampung and Yogyakarta areas of Indonesia. These provinces were selected for comparison of the influence of human/tourism activities. Data on population parameters that was collected included data on life expectancy according to age class, numbers of individuals by sex and age class, and ‘ratio of infants to reproductive females’. The estimation of population growth was based on a population dynamic growth model: the Leslie matrix. The harvesting quota was calculated as being the difference between the actual population size and the MVP (minimum viable population) for each sex and age class. Observation indicated that there were variations within group size (24 – 106 individuals), gender (sex) ratio (1:1 to 1:1.3), life expectancy value (0.30 to 0.93), and ‘ratio of infants to reproductive females’ (0.23 to 1.56). Results of subsequent calculations showed that sustainable harvesting quotas for each studied group of long-tailed macaques, ranged from 29 to 110 individuals. An estimation model of the MVP for each age class was formulated as Log Y = 0.315 + 0.884 Log Ni (number of individual on ith age class). This study also found that life expectancy for the juvenile age class was affected by the humidity under tree stands, and dietary plants’ density at sapling, pole and tree stages (equation: Y= 2.296 – 1.535 RH + 0.002 Kpcg – 0.002 Ktg – 0.001 Kphn, R2 = 89.6% with a significance value of 0.001). By contrast, for the sub-adult-adult age class, life expectancy was significantly affected by slope (equation: Y=0.377 = 0.012 Kml, R2 = 50.4%, with significance level of 0.007). The infant to reproductive female ratio was affected by humidity under tree stands, and dietary plant density at sapling and pole stages (equation: Y = -1.432 + 2.172 RH – 0.004 Kpcg + 0.003 Ktg, R2 = 82.0% with significance level of 0.001). This research confirmed the importance of population parameters in determining the minimum viable population, and that MVP varied according to habitat characteristics (especially food availability). It would be difficult therefore, to formulate a general mathematical equation model for determining a harvesting quota for the species as a whole.Keywords: harvesting, long-tailed macaque, population, quota
Procedia PDF Downloads 4262232 Lip Localization Technique for Myanmar Consonants Recognition Based on Lip Movements
Authors: Thein Thein, Kalyar Myo San
Abstract:
Lip reading system is one of the different supportive technologies for hearing impaired, or elderly people or non-native speakers. For normal hearing persons in noisy environments or in conditions where the audio signal is not available, lip reading techniques can be used to increase their understanding of spoken language. Hearing impaired persons have used lip reading techniques as important tools to find out what was said by other people without hearing voice. Thus, visual speech information is important and become active research area. Using visual information from lip movements can improve the accuracy and robustness of a speech recognition system and the need for lip reading system is ever increasing for every language. However, the recognition of lip movement is a difficult task because of the region of interest (ROI) is nonlinear and noisy. Therefore, this paper proposes method to detect the accurate lips shape and to localize lip movement towards automatic lip tracking by using the combination of Otsu global thresholding technique and Moore Neighborhood Tracing Algorithm. Proposed method shows how accurate lip localization and tracking which is useful for speech recognition. In this work of study and experiments will be carried out the automatic lip localizing the lip shape for Myanmar consonants using the only visual information from lip movements which is useful for visual speech of Myanmar languages.Keywords: lip reading, lip localization, lip tracking, Moore neighborhood tracing algorithm
Procedia PDF Downloads 3532231 Application of Change Detection Techniques in Monitoring Environmental Phenomena: A Review
Authors: T. Garba, Y. Y. Babanyara, T. O. Quddus, A. K. Mukatari
Abstract:
Human activities make environmental parameters in order to keep on changing globally. While some changes are necessary and beneficial to flora and fauna, others have serious consequences threatening the survival of their natural habitat if these changes are not properly monitored and mitigated. In-situ assessments are characterized by many challenges due to the absence of time series data and sometimes areas to be observed or monitored are inaccessible. Satellites Remote Sensing provide us with the digital images of same geographic areas within a pre-defined interval. This makes it possible to monitor and detect changes of environmental phenomena. This paper, therefore, reviewed the commonly use changes detection techniques globally such as image differencing, image rationing, image regression, vegetation index difference, change vector analysis, principal components analysis, multidate classification, post-classification comparison, and visual interpretation. The paper concludes by suggesting the use of more than one technique.Keywords: environmental phenomena, change detection, monitor, techniques
Procedia PDF Downloads 2742230 Effects of China's Urban Form on Urban Carbon Emission
Authors: Lu Lin
Abstract:
Urbanization has reshaped physical environment, energy consumption and carbon emission of the urban area. China is a typical developing country under a rapid urbanization process and is the world largest carbon emission country. This study aims to explore the correlation between urban form and carbon emission caused by urban energy consumption in China. 287 provincial-level and prefecture-level cities are studied in 2000, 2005, and 2010. Compact ratio index, shape index, and fractal dimension index are used to quantify urban form. Geographically weighted regression (GWR) model is employed to explore the relationship between urban form, energy consumption, and related carbon emission. The results show the average compact ratio index decreased from 2000 to 2010 which indicates urban in China sprawled. The average fractal dimension index increases by 3%, indicating the spatial layouts of China's cities were more complicated. The results by the GWR model show that shape index and fractal dimension index had a non-significant relationship with carbon emission by urban energy consumption. However, compact urban form reduced carbon emission. The findings of this study will help policy-makers make sustainable urban planning and reduce urban carbon emission.Keywords: carbon emission, GWR model, urban energy consumption, urban form
Procedia PDF Downloads 3402229 Rural Households’ Resilience to Food Insecurity in Niger
Authors: Aboubakr Gambo, Adama Diaw, Tobias Wunscher
Abstract:
This study attempts to identify factors affecting rural households’ resilience to food insecurity in Niger. For this, we first create a resilience index by using Principal Component Analysis on the following five variables at the household level: income, food expenditure, duration of grain held in stock, livestock in Tropical Livestock Units and number of farms exploited and second apply Structural Equation Modelling to identify the determinants. Data from the 2010 National Survey on Households’ Vulnerability to Food Insecurity done by the National Institute of Statistics is used. The study shows that asset and social safety nets indicators are significant and have a positive impact on households’ resilience. Climate change approximated by long-term mean rainfall has a negative and significant effect on households’ resilience to food insecurity. The results indicate that to strengthen households’ resilience to food insecurity, there is a need to increase assistance to households through social safety nets and to help them gather more resources in order to acquire more assets. Furthermore, early warning of climatic events could alert households especially farmers to be prepared and avoid important losses that they experience anytime an uneven climatic event occur.Keywords: food insecurity, principal component analysis, structural equation modelling, resilience
Procedia PDF Downloads 361