Search results for: heat generation/absorption

Authors: Asrat M.Belachew, Tiago Pereira, Institute of Mathematics, Computer Sciences, Avenida Trabalhador São Carlense, 400, São Carlos, 13566-590, Brazil

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Infectious diseases are among the most prominent threats to human beings. They cause morbidity and mortality to an individual and collapse the social, economic, and political systems of the whole world collectively. Mathematical models are fundamental tools and provide a comprehensive understanding of how infectious diseases spread and designing the control strategy to mitigate infectious diseases from the host population. Modeling the spread of infectious diseases using a compartmental model of inhomogeneous populations is good in terms of complexity. However, in the real world, there is a situation that accounts for heterogeneity, such as ages, locations, and contact patterns of the population which are ignored in a homogeneous setting. In this work, we study how classical an SEIR infectious disease spreading of the compartmental model can be extended by incorporating the mobility of population between heterogeneous cities during an outbreak of infectious disease. We have formulated an SEIR multi-cities epidemic spreading model using a system of 4k ordinary differential equations to describe the disease transmission dynamics in k-cities during the day and night. We have shownthat the model is epidemiologically (i.e., variables have biological interpretation) and mathematically (i.e., a unique bounded solution exists all the time) well-posed. We constructed the next-generation matrix (NGM) for the model and calculated the basic reproduction number R0for SEIR-epidemic spreading model with cities mobility. R0of the disease depends on the spectral radius mobility operator, and it is a threshold between asymptotic stability of the disease-free equilibrium and disease persistence. Using the eigenvalue perturbation theorem, we showed that sending a fraction of the population between cities decreases the reproduction number of diseases in interconnected cities. As a result, disease transmissiondecreases in the population.

Keywords: SEIR-model, mathematical model, city mobility, epidemic spreading

Procedia PDF Downloads 95

Authors: Abbas Raza Ali

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Big Data technology is gradually becoming a dire need of large enterprises. These enterprises are generating massively large amount of off-line and streaming data in both structured and unstructured formats on daily basis. It is a challenging task to effectively extract useful insights from the large scale datasets, even though sometimes it becomes a technology constraint to manage transactional data history of more than a few months. This paper presents a framework to efficiently manage massively large and complex datasets. The framework has been tested on a communication service provider producing massively large complex streaming data in binary format. The communication industry is bound by the regulators to manage history of their subscribers’ call records where every action of a subscriber generates a record. Also, managing and analyzing transactional data allows service providers to better understand their customers’ behavior, for example, deep packet inspection requires transactional internet usage data to explain internet usage behaviour of the subscribers. However, current relational database systems limit service providers to only maintain history at semantic level which is aggregated at subscriber level. The framework addresses these challenges by leveraging Big Data technology which optimally manages and allows deep analysis of complex datasets. The framework has been applied to offload existing Intelligent Network Mediation and relational Data Warehouse of the service provider on Big Data. The service provider has 50+ million subscriber-base with yearly growth of 7-10%. The end-to-end process takes not more than 10 minutes which involves binary to ASCII decoding of call detail records, stitching of all the interrogations against a call (transformations) and aggregations of all the call records of a subscriber.

Keywords: big data, communication service providers, enterprise data warehouse, stream computing, Telco IN Mediation

Procedia PDF Downloads 158

Authors: Gustave Semugaza, Anne Zora Gierth, Tommy Mielke, Marianela Escobar Castillo, Nat Doru C. Lupascu

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The generation of Construction and Demolition Waste (CDW) has globally increased enormously due to the enhanced need in construction, renovation, and demolition of construction structures. Several studies investigated the use of CDW materials in the production of new concrete and indicated the lower mechanical properties of the resulting concrete. Many other researchers considered the possibility of using the Hydrated Cement Powder (HCP) to replace a part of Ordinary Portland Cement (OPC), but only very few investigated the use of Recycled Concrete Powder (RCP) from CDW. The partial replacement of OPC for making new concrete intends to decrease the CO₂ emissions associated with OPC production. However, the RCP and HCP need treatment to produce the new concrete of required mechanical properties. The thermal treatment method has proven to improve HCP properties before their use. Previous research has stated that for using HCP in concrete, the optimum results are achievable by heating HCP between 400°C and 800°C. The optimum heating temperature depends on the type of cement used to make the Hydrated Cement Specimens (HCS), the crushing and heating method of HCP, and the curing method of the Rehydrated Cement Specimens (RCS). This research assessed the quality of recycled materials by using different techniques such as X-ray Diffraction (XRD), Differential Scanning Calorimetry (DSC) and thermogravimetry (TG), Scanning electron Microscopy (SEM), and X-ray Fluorescence (XRF). These recycled materials were thermally pretreated at different temperatures from 200°C to 1000°C. Additionally, the research investigated to what extent the thermally treated recycled cement could partially replace the OPC and if the new concrete produced would achieve the required mechanical properties. The mechanical properties were evaluated on the RCS, obtained by mixing the Dehydrated Cement Powder and Recycled Powder (DCP and DRP) with water (w/c = 0.6 and w/c = 0.45). The research used the compressive testing machine for compressive strength testing, and the three-point bending test was used to assess the flexural strength.

Keywords: hydrated cement powder, dehydrated cement powder, recycled concrete powder, thermal treatment, reactivation, mechanical performance

Procedia PDF Downloads 131

Authors: Mustafa Taskin, Ozgur Demir, M. Mert Serveren

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The precise study of the impact of underwater explosions on structures is of great importance in the design and engineering calculations of floating structures, especially those used for military purposes, as well as power generation facilities such as offshore platforms that can become a target in case of war. Considering that ship and submarine structures are mostly curved surfaces, it is extremely important and interesting to examine the destructive effects of underwater explosions on curvilinear surfaces. In this study, geometric nonlinear dynamic analysis of cylindrical composite sandwich shells subjected to instantaneous pressure load is performed. The instantaneous pressure load is defined as an underwater explosion and the effects of the liquid medium are taken into account. There are equations in the literature for pressure due to underwater explosions, but these equations have been obtained for flat plates. For this reason, the instantaneous pressure load equations are arranged to be suitable for curvilinear structures before proceeding with the analyses. Fluid-solid interaction is defined by using Taylor's Plate Theory. The lower and upper layers of the cylindrical composite sandwich shell are modeled as composite laminate and the middle layer consists of soft core. The geometric nonlinear dynamic equations of the shell are obtained by Hamilton's principle, taken into account the von Kàrmàn theory of large displacements. Then, time dependent geometric nonlinear equations of motion are solved with the help of generalized differential quadrature method (GDQM) and dynamic behavior of cylindrical composite sandwich shells exposed to underwater explosion is investigated. An algorithm that can work parametrically for the solution has been developed within the scope of the study.

Keywords: cylindrical composite sandwich shells, generalized differential quadrature method, geometric nonlinear dynamic analysis, underwater explosion

Procedia PDF Downloads 175

Authors: M. Soleimani, D. Cree, C. Chafe, L. Bates

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The accidental release of petroleum products into the environment could have harmful consequences to our ecosystem. Different techniques such as mechanical separation, membrane filtration, incineration, treatment processes using enzymes and dispersants, bioremediation, and sorption process using sorbents have been applied for oil spill remediation. Most of the techniques investigated are too costly or do not have high enough efficiency. This study was conducted to determine the sorption performance of hemp byproducts (cellulosic materials) in terms of sorption capacity and kinetics for hydrophobic and hydrophilic fluids. In this study, heavy oil, light oil, diesel fuel, and water/water vapor were used as sorbate fluids. Hemp stalk in different forms, including loose material (hammer milled (HM) and shredded (Sh) with low bulk densities) and densified forms (pellet form (P) and crumbled pellets (CP)) with high bulk densities, were used as sorbents. The sorption/retention tests were conducted according to ASTM 726 standard. For a quick-purpose application of the sorbents, the sorption tests were conducted for 15 min, and for an ideal sorption capacity of the materials, the tests were carried out for 24 h. During the test, the sorbent material was exposed to the fluid by immersion, followed by filtration through a stainless-steel wire screen. Water vapor adsorption was carried out in a controlled environment chamber with the capability of controlling relative humidity (RH) and temperature. To determine the kinetics of sorption for each fluid and sorbent, the retention capacity also was determined intervalley for up to 24 h. To analyze the kinetics of sorption, pseudo-first-order, pseudo-second order and intraparticle diffusion models were employed with the objective of minimal deviation of the experimental results from the models. The results indicated that HM and Sh materials had the highest sorption capacity for the hydrophobic fluids with approximately 6 times compared to P and CP materials. For example, average retention values of heavy oil on HM and Sh was 560% and 470% of the mass of the sorbents, respectively. Whereas, the retention of heavy oil on P and CP was up to 85% of the mass of the sorbents. This lower sorption capacity for P and CP can be due to the less exposed surface area of these materials and compacted voids or capillary tubes in the structures. For water uptake application, HM and Sh resulted in at least 40% higher sorption capacity compared to those obtained for P and CP. On average, the performance of sorbate uptake from high to low was as follows: water, heavy oil, light oil, diesel fuel. The kinetic analysis indicated that the second-pseudo order model can describe the sorption process of the oil and diesel better than other models. However, the kinetics of water absorption was better described by the pseudo-first-order model. Acetylation of HM materials could improve its oil and diesel sorption to some extent. Water vapor adsorption of hemp fiber was a function of temperature and RH, and among the models studied, the modified Oswin model was the best model in describing this phenomenon.

Keywords: environment, fiber, petroleum, sorption

Procedia PDF Downloads 113

Authors: M. Baratieri, M. Beccali, S. Corradino, B. Di Pietra, C. La Grassa, F. Monteleone, G. Morosinotto, G. Puglisi

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The energy renovation of existing buildings represents an important opportunity to increase the decarbonization and the sustainability of urban environments. In this context, the work carried out has the objective of demonstrating the technical and economic feasibility of an energy renovate of a public building destined for offices located on the island of Lampedusa in the Mediterranean Sea. By applying the Italian transpositions of European Directives 2010/31/EU and 2009/28/EC, the building has been renovated from the current energy requirements of 111.7 kWh/m² to 16.4 kWh/m². The result achieved classifies the building as nZEB (nearly Zero Energy Building) according to the Italian national definition. The analysis was carried out using in parallel a quasi-stationary software, normally used in the professional field, and a dynamic simulation model often used in the academic world. The proposed interventions cover the components of the building’s envelope, the heating-cooling system and the supply of energy from renewable sources. In these latter points, the analysis has focused more on assessing two aspects that affect the supply of renewable energy. The first concerns the use of advanced logic control systems for air conditioning units in order to increase photovoltaic self-consumption. With these adjustments, a considerable increase in photovoltaic self-consumption and a decrease in the electricity exported to the Island's electricity grid have been obtained. The second point concerned the evaluation of the building's energy classification considering the real efficiency of the heating-cooling plant. Normally the energy plants have lower operational efficiency than the designed one due to multiple reasons; the decrease in the energy classification of the building for this factor has been quantified. This study represents an important example for the evaluation of the best interventions for the energy renovation of buildings in the Mediterranean Climate and a good description of the correct methodology to evaluate the resulting improvements.

Keywords: heat pumps, HVAC systems, nZEB renovation, renewable energy sources

Procedia PDF Downloads 436

Authors: Shu-Yu Chung, Ying-Fang Wang, Shih-Min Wang

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To conduct long-term exposure assessments are important for workers exposed to chemicals with chronic effects. However, it usually encounters with several constrains, including cost, workers' willingness, and interference to work practice, etc., leading to inadequate long-term exposure data in the real world. In this study, an integrated approach was developed for conducting long-term exposure assessment for welding workers in a shipbuilding factory. A laboratory study was conducted to yield the fume generation rates under various operating conditions. The results and the measured environmental conditions were applied to the near field/far field (NF/FF) model for predicting long term fume exposures via the Monte Carlo simulation. Then, the predicted long-term concentrations were used to determine the prior distribution in Bayesian decision analysis (BDA). Finally, the resultant posterior distributions were used to assess the long-term exposure and serve as basis for initiating control strategies for shipbuilding workers. Results show that the NF/FF model was a suitable for predicting the exposures of metal contents containing in welding fume. The resultant posterior distributions could effectively assess the long-term exposures of shipbuilding welders. Welders' long-term Fe, Mn and Pb exposures were found with high possibilities to exceed the action level indicating preventive measures should be taken for reducing welders' exposures immediately. Though the resultant posterior distribution can only be regarded as the best solution based on the currently available predicting and monitoring data, the proposed integrated approach can be regarded as a possible solution for conducting long term exposure assessment in the field.

Keywords: Bayesian decision analysis, exposure assessment, near field and far field model, shipbuilding industry, welding fume

Procedia PDF Downloads 122

Authors: Sinarwati Mohamad Suhaili, Naomie Salim, Mohamad Nazim Jambli

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Sequence-to-sequence (seq2seq) models augmented with attention mechanisms are playing an increasingly important role in automated customer service. These models, which are able to recognize complex relationships between input and output sequences, are crucial for optimizing chatbot responses. Central to these mechanisms are neural attention weights that determine the focus of the model during sequence generation. Despite their widespread use, there remains a gap in the comparative analysis of different attention weighting functions within seq2seq models, particularly in the domain of chatbots using the Customer Support Twitter (CST) dataset. This study addresses this gap by evaluating four distinct attention-scoring functions—dot, multiplicative/general, additive, and an extended multiplicative function with a tanh activation parameter — in neural generative seq2seq models. Utilizing the CST dataset, these models were trained and evaluated over 10 epochs with the AdamW optimizer. Evaluation criteria included validation loss and BLEU scores implemented under both greedy and beam search strategies with a beam size of k=3. Results indicate that the model with the tanh-augmented multiplicative function significantly outperforms its counterparts, achieving the lowest validation loss (1.136484) and the highest BLEU scores (0.438926 under greedy search, 0.443000 under beam search, k=3). These results emphasize the crucial influence of selecting an appropriate attention-scoring function in improving the performance of seq2seq models for chatbots. Particularly, the model that integrates tanh activation proves to be a promising approach to improve the quality of chatbots in the customer support context.

Keywords: attention weight, chatbot, encoder-decoder, neural generative attention, score function, sequence-to-sequence

Procedia PDF Downloads 65

Authors: Juan Luis Leal, Rafael Maestre, Ovidio López

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As innovation progresses, more possibilities are made available to increase the efficiency and reach of solutions for Smart Cities, most of which require the data provided by the Internet of Things (IoT) devices and may even have higher power requirements such as motors or actuators. A reliable power supply with the lowest maintenance is a requirement for the success of these solutions in the long term. Energy harvesting, mainly solar, becomes the solution of choice in most cases, but only if there is enough power to be harvested, which may depend on the device location (e.g., outdoors vs. indoor). This is the case of Smart Waste Containers with compaction systems, which have moderately high-power requirements, and may be installed in places with little sunlight for solar generation. It should be noted that waste is unloaded from the containers with cranes, so sudden and irregular movements may happen, making wired power unviable. In these cases, a wireless power supply may be a great alternative. This paper proposes a cost-effective two coil resonant wireless power transfer (WPT) system and describes its implementation, which has been carried out within an R&D project and validated in real settings with smart containers. Experimental results prove that the developed system achieves wireless power transmission up to 35W in the range of 5 cm to 1 m with a peak efficiency of 78%. The circuit is operated at relatively low resonant frequencies, which combined with enough wire-to-wire separation between the coil windings, reduce the losses caused by the proximity effect and, therefore, allow the use of common stranded wire instead of Litz wire, this without reducing the efficiency significantly. All these design considerations led to a final system that achieves a high efficiency for the desired charging range, simplifying the energy supply for Smart Containers as well as other devices that may benefit from a cost-effective wireless charging system.

Keywords: electromagnetic coupling, resonant wireless charging, smart recycling containers, wireless power transfer

Procedia PDF Downloads 77

Authors: Sung-Jun Yoo, Kazuhide Ito

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In this study, a comprehensive computer simulated person (CSP) that integrates computational human model (virtual manikin) and respiratory tract model (virtual airway), was applied for estimation of indoor environmental quality. Moreover, an inclusive prediction method was established by integrating computational fluid dynamics (CFD) analysis with advanced CSP which is combined with physiologically-based pharmacokinetic (PBPK) model, unsteady thermoregulation model for analysis targeting micro-climate around human body and respiratory area with high accuracy. This comprehensive method can estimate not only the contaminant inhalation but also constant interaction in the contaminant transfer between indoor spaces, i.e., a target area for indoor air quality (IAQ) assessment, and respiratory zone for health risk assessment. This study focused on the usage of the CSP as an air/thermal quality sensor in indoors, which means the application of comprehensive model for assessment of IAQ and thermal environmental quality. Demonstrative analysis was performed in order to examine the applicability of the comprehensive model to the heating, ventilation, air conditioning (HVAC) control scheme. CSP was located at the center of the simple model room which has dimension of 3m×3m×3m. Formaldehyde which is generated from floor material was assumed as a target contaminant, and flow field, sensible/latent heat and contaminant transfer analysis in indoor space were conducted by using CFD simulation coupled with CSP. In this analysis, thermal comfort was evaluated by thermoregulatory analysis, and respiratory exposure risks represented by adsorption flux/concentration at airway wall surface were estimated by PBPK-CFD hybrid analysis. These Analysis results concerning IAQ and thermal comfort will be fed back to the HVAC control and could be used to find a suitable ventilation rate and energy requirement for air conditioning system.

Keywords: CFD simulation, computer simulated person, HVAC control, indoor environmental quality

Procedia PDF Downloads 350

Authors: Julian Jaegers, Siegmar Wirtz, Viktor Scherer

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

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

Procedia PDF Downloads 133

Authors: N. Lakshmipathy, Ch. S. N. Murthy, M. Aruna

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The design of lighting systems for surface mines is not an easy task because of the unique environment and work procedures encountered in the mines. The primary objective of this paper is to identify the major problems encountered in mine lighting application and to provide guidance in the solution of these problems. In the surface mining reflectance of surrounding surfaces is one of the important factors, which improve the vision, in the night hours. But due to typical working nature in the mines it is very difficult to fulfill these requirements, and also the orientation of the light at work site is a challenging task. Due to this reason machine operator and other workers in a mine need to be able to orient themselves in a difficult visual environment. The haul roads always keep on changing to tune with the mining activity. Other critical area such as dumpyards, stackyards etc. also change their phase with time, and it is difficult to illuminate such areas. Mining is a hazardous occupation, with workers exposed to adverse conditions; apart from the need for hard physical labor, there is exposure to stress and environmental pollutants like dust, noise, heat, vibration, poor illumination, radiation, etc. Visibility is restricted when operating load haul dumper and Heavy Earth Moving Machinery (HEMM) vehicles resulting in a number of serious accidents. one of the leading causes of these accidents is the inability of the equipment operator to see clearly people, objects or hazards around the machine. Results indicate blind spots are caused primarily by posts, the back of the operator's cab, and by lights and light brackets. The careful designed and implemented, lighting systems provide mine workers improved visibility and contribute to improved safety, productivity and morale. Properly designed lighting systems can improve visibility and safety during working in the opencast mines.

Keywords: contrast, efficacy, illuminance, illumination, light, luminaire, luminance, reflectance, visibility

Procedia PDF Downloads 345

Authors: Takahiro Saida, Takahiro Kogiso, Takahiro Maruyama

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The ordered structural carbon (OSC) material is expected to apply to the electrode of secondary batteries, the catalyst supports, and the biomaterials because it shows the low substance-diffusion resistance by its uniform pore size. In general, the OSC material is synthesized using the template material. Changing size and shape of this template provides the pore size of OSC material according to the purpose. Depositing the oxide nanosheets on the polymer sphere template by the layer by layer (LbL) method was reported as one of the preparation methods of OSC material. The LbL method can provide the controlling thickness of structural wall without the surface modification. When the preparation of the uniform carbon sphere prepared by the LbL method which composed of the graphene oxide wall and the polymethyl-methacrylate (PMMA) core, the reduction treatment will be the important object. Since the graphene oxide has poor electron conductivity due to forming a lot of functional groups on the surface, it could be hard to apply to the electrode of secondary batteries and the catalyst support of fuel cells. In this study, the graphene oxide wall of carbon sphere was reduced by the thermal treatment under the vacuum conditions, and its crystalline structure and electronic state were characterized. Scanning electron microscope images of the carbon sphere after the heat treatment at 300ºC showed maintaining sphere shape, but its shape was collapsed with increasing the heating temperature. In this time, the dissolution rate of PMMA core and the reduction rate of graphene oxide were proportionate to heating temperature. In contrast, extending the heating time was conducive to the conservation of the sphere shape. From results of X-ray photoelectron spectroscopy analysis, its electronic state of the surface was indicated mainly sp² carbon. From the above results, we succeeded in the synthesis of the sphere structure composed by the reduction graphene oxide.

Keywords: carbon sphere, graphene oxide, reduction, layer by layer

Procedia PDF Downloads 129

Authors: Monalisha Ghosh, Asit Mohanty

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The lack of sanitation increases living costs, decreases spend on education and nutrition, lowers income earning potential, and threatens safety and welfare. This is especially true for rural India. Only 32% of rural households have their own toilets and that less than half of Indian households have a toilet at home. Of the estimated billion people in the world who defecate in the open, more than half reside in rural India. It is empirically established that poor sanitation leads to high infant mortality rate and low income generation in rural India. In India, 1,600 children die every day before reaching their fifth birthday and 24% of girls drop out of school as the lack of basic sanitation. Above all, lack of sanitation is not a symptom of poverty but a major contributing factor. According to census 2011, 67.3% of the rural households in the country still did not have access to sanitation facilities. India’s sanitation deficit leads to losses worth roughly 6% of its gross domestic product (GDP) according to World Bank estimates by raising the disease burden in the country. The dropout rate for girl child is thirty percent in schools in rural areas because of lack of sanitation facilities for girl students. The productivity loss per skilled labors during a year is calculated at Rs.44, 160 in Odisha. The performance of the state of Odisha has not been satisfactory in improving sanitation facilities. The biggest challenge is triggering behavior change in vast section of rural population regarding need to use toilets. Another major challenge is funding and implementation for improvement of sanitation facility. In an environment of constrained economic resources, Public Private Partnership in form of performance based management or maintenance contract will be all the more relevant to improve the sanitation status in rural sector.

Keywords: rural sanitation, infant mortality rate, income, granger causality, pooled OLS method test public private partnership

Procedia PDF Downloads 403

Authors: Yasaman Samie

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The ever-increasing rate of textile and clothing (T&C) waste generation and the common ineffective waste management practices have been for long a challenge for civic waste management. This challenge stems from not only the complexity in the T&C material components but also the heterogeneous nature of the T&C waste management sector and the disconnection between the stakeholders. To date, there is little research that investigates the importance of a governmental structure and its role in T&C waste managerial practices and decision makings. This paper reflects on the impacts and involvement of governments, the Acts, and legislation on the effectiveness of T&C waste management practices, which are carried out by multiple players in a city context. In doing so, this study first develops a methodical framework for holistically analyzing a city’s T&C waste ecosystem. Central to this framework are six dimensions: social, environmental, economic, political, cultural, and educational, as well as the connection between these dimensions such as Socio-Political and Cultural-Political. Second, it delves into the political dimension and its interconnections with varying aspects of T&C waste. In this manner, this case-study takes metropolitan Melbourne as a case and draws on social theories of Actor-Network Theory and the principals of supply chain design and planning. Data collection was through two rounds of semi-structured interviews with 18 key players of T&C waste ecosystem (including charities, city councils, private sector providers and producers) mainly within metropolitan Melbourne and also other Australian and European cities. Research findings expand on the role of the politics of waste in facilitating a proactive approach to T&C waste management in the cities. That is achieved through a revised definition for T&C waste and its characteristics, discussing the varying perceptions of value in waste, prioritizing waste types in civic waste management practices and how all these aspects shall be reflected in the in-placed acts and legislations.

Keywords: civic waste management, multi-stakeholder ecosystem, textile and clothing waste, waste and governments

Procedia PDF Downloads 97

Authors: Katarzyna Zięba, Hajnalka Szentgyörgyi, Paweł Miśkowiec, Agnieszka Moos-Matysik

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Bees are effective pollinators of plants using by humans. However, there is a concern about the fate different species due to their recently decline. Pollution of the environment is described in the literature as one of the causes of this phenomenon. Due to human activities, heavy metals and aromatic hydrocarbons can occur in bee organisms in high concentrations. The presented study aims to provide information on how pollution affects bee quality, taking into account, also the biological differences between various groups of bees. Understanding the consequences of environmental pollution on bees can help to create and promote bee friendly habitats and actions. The analyses were carried out using two contamination gradients with 5 sites on each. The first, mainly heavy metal polluted gradient is stretching approx. 30km from the Bukowno Zinc smelter near Olkusz in the Lesser Poland Voivodship, to the north. The second cuts through the agglomeration of Kraków up to the southern borders of the Ojców National Park. The gradient near Olkusz is a well-described pollution gradient contaminated mainly by zinc, lead, and cadmium. The second gradient cut through the agglomeration of Kraków and end below the Ojców National Park. On each gradient, two bee species were installed: red mason bees (Osmia bicornis) and honey bees (Apis mellifera). Red mason bee is a polylectic, solitary bee species, widely distributed in Poland. Honey bees are a highly social species of bees, with clearly defined casts and roles in the colony. Before installing the bees in the field, samples of imagos of red mason bees and samples of pollen and imagos from each honey bee colony were analysed for zinc, lead cadmium, polycyclic and monocyclic hydrocarbons levels. After collecting the bees from the field, samples of bees and pollen samples for each site were prepared for heavy metal, monocyclic hydrocarbon, and polycyclic hydrocarbon analysis. Analyses of aromatic hydrocarbons were performed with gas chromatography coupled with a headspace sampler (HP 7694E) and mass spectrometer (MS) as detector. Monocyclic compounds were injected into column with headspace sampler while polycyclic ones with manual injector (after solid-liquid extraction with hexane). The heavy metal content (zinc, lead and cadmium) was assessed with flame atomic absorption spectroscopy (FAAS AAnalyst 300 Perkin Elmer spectrometer) according to the methods for honey and bee products described in the literature. Pollution levels found in bee bodies and imago body masses in both species, and proportion of sex in case of red mason bees were correlated with pollution levels found in pollen for each site and colony or trap nest. An attempt to pinpoint the most important form of contamination regarding bee health was also be undertaken based on the achieved results.

Keywords: heavy metals, aromatic hydrocarbons, bees, pollution

Procedia PDF Downloads 497

Authors: Zhanara Suleimenova, Raushan Blieva, Aigerim Zhakipbekova, Inkar Tapenbayeva, Zhanar Narmuratova

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Green processes are based on innovative technologies that do not negatively affect the environment. Industrial enzymes originated from biological systems can effectively contribute to sustainable development through being isolated from microorganisms which are fermented using primarily renewable resources. Many widespread microorganisms secrete a significant amount of biocatalysts into the environment, which greatly facilitates the task of their isolation and purification. The ability to control the enzyme production through the regulation of their biosynthesis and the selection of nutrient media and cultivation conditions allows not only to increase the yield of enzymes but also to obtain enzymes with certain properties. In this regard, large potentialities are embedded in immobilized cells. Enzyme production technology in a secreted active form enabling industrial application on an economically feasible scale has been developed. This method is based on the immobilization of enzyme producers on a solid career. Immobilizing has a range of advantages: decreasing the price of the final product, absence of foreign substances, controlled process of enzyme-genesis, the ability of various enzymes' simultaneous production, etc. Design of proposed equipment gives the opportunity to increase the activity of immobilized cell culture filtrate comparing to free cells, growing in periodic culture conditions. Such technology allows giving a 10-times raise in culture productivity, to prolong the process of fungi cultivation and periods of active culture liquid generation. Also, it gives the way to improve the quality of filtrates (to make them more clear) and exclude time-consuming processes of recharging fermentative vials, that require manual removing of mycelium.

Keywords: industrial enzymes, immobilization, submerged fermentation, microscopic fungi

Procedia PDF Downloads 127

Authors: S. A. N. Rashani, S. Pigera, P. N. J. Fernando, S. Jayawickema, M. A. Niriella, A. P. De Silva

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Dietary supplement (DS) consumption is drastically trending among the young athlete generation in developing countries. Many athletes try to fulfill their nutrition requirements using dietary supplements without knowing their effects on health and performance. This study aimed to assess the DS usage patterns of university athletes in Sri Lanka. A self-administered questionnaire was employed to collect data from state university students representing a university team, and a sample of 200 respondents was selected based on a stratified random sampling technique. Incomplete questionnaires were omitted from the analysis. The data were analyzed using IBM SPSS statistics for Windows version 25. The level of significance was set at p<0.05 in the data analysis. The prevalence of DS was 48.2% (n= 94), with no significant association between gender and DS intake. Protein (15.9%), vitamin (14.9%), sports drinks (12.8%), and creatine (8.2%) were the most consumed DS by students. Weightlifting (85.0%), football (62.5%), rugby (57.7%), and wrestling (40.9%) players showed higher DS usage among other sports. Coaches were reported as the most frequent person who was advised to use DS (43.0%). Students who won interuniversity games showed significantly low DS intake (p = 0.002) compared to others. Interestingly, DS use was significantly affected by the season of use (p = 0.000), pointing out that during competition and training seasons (62.4%) was the most frequent use. The pharmacy (27.0%) was the commonest place to buy DS. Students who used nutrient-dense meal plans during the training and competition period still showed a 61.0% tendency to consume DS. Most claimed reason to use DS was to increase energy and strength (29.0%). A majority reported that they used DS for less than one month (35.5%), while the second-highest duration was over three years (17.2%). Considering body mass index (BMI), healthy weight students showed 71.0% DS prevalence. DS prevalence was moderate among Sri Lankan university students, highlighting that the highest DS use was during competition and training seasons. Moreover, it emphasizes the need for nutrition and anti-doping counseling in the Sri Lankan university system.

Keywords: athlete, dietary, supplements, university

Procedia PDF Downloads 186

Authors: Anahita Suri

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Craft -an integral part of the conduit to create something beautiful- is a visual representation of the human imagination given life through the hand. The Mirgan tribe in the Naxalite infested forests of Koraput, Odisha are not exempt from this craving for beauty. These skilled craftsmen dye and weave the simple yet sophisticated Kotpad textiles. The women undertake the time-consuming task of dyeing the cotton and silk yarns with the root of the aul tree. The men then weave these yarns into beautiful sarees and dupattas. The root of the aul tree lends the textile its maroon to brown color, which is offset against the unbleached cotton to create a minimalist and distinctive look. The motifs, incorporated through the extra weft technique, reflect the rich tribal heritage of the community. This is an eco-friendly, non-toxic textile. Kotpad fabrics were on the verge of extinction due to various factors like poor infrastructure, no innovation in traditional designs/products, customer ignorance leading to low demand. With livelihood opportunities through craft slowly dwindling, artisans were moving to alternative sources of income generation, like agriculture and daily wage labor. There was an urgent need for intervention to revive the craft, spread awareness about them in urban spaces, and strengthen the artisan’s ability to innovate and create. Recent efforts by government bodies and local designers have given Kotpad handloom a contemporary look without diluting its essence. This research explores the possibilities to leverage Kotpad handloom to find a place in the dynamic culture of the world by its promotion among different target groups and incorporating self-sustaining practices for the artisans. This could further encourage a space for handmade and handcrafted art, rich with stories about India, with a contemporary visual sensibility. This will strengthen environmental and ethical sustainability.

Keywords: craft, contemporary, handloom, natural dye, tribal

Procedia PDF Downloads 129

Authors: S.V. Kleyn, S.Yu. Zagorodnov, А.А. Kokoulina

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Technogenic emissions of the mining and processing complex are characterized by a high content of chemical components and solid dust particles. However, each industrial enterprise and the surrounding area have features that require refinement and parameterization. Numerous studies have shown the negative impact of fine dust PM10 and PM2.5 on the health, as well as the possibility of toxic components absorption, including heavy metals by dust particles. The target of the study was the quantitative assessment of the fractional and particle size composition of ambient air dust in the area of impact by primary magnesium production complex. Also, we tried to describe the morphology features of dust particles. Study methods. To identify the dust emission sources, the analysis of the production process has been carried out. The particulate composition of the emissions was measured using laser particle analyzer Microtrac S3500 (covered range of particle size is 20 nm to 2000 km). Particle morphology and the component composition were established by electron microscopy by scanning microscope of high resolution (magnification rate - 5 to 300 000 times) with X-ray fluorescence device S3400N ‘HITACHI’. The chemical composition was identified by X-ray analysis of the samples using an X-ray diffractometer XRD-700 ‘Shimadzu’. Determination of the dust pollution level was carried out using model calculations of emissions in the atmosphere dispersion. The calculations were verified by instrumental studies. Results of the study. The results demonstrated that the dust emissions of different technical processes are heterogeneous and fractional structure is complicated. The percentage of particle sizes up to 2.5 micrometres inclusive was ranged from 0.00 to 56.70%; particle sizes less than 10 microns inclusive – 0.00 - 85.60%; particle sizes greater than 10 microns - 14.40% -100.00%. During microscopy, the presence of nanoscale size particles has been detected. Studied dust particles are round, irregular, cubic and integral shapes. The composition of the dust includes magnesium, sodium, potassium, calcium, iron, chlorine. On the base of obtained results, it was performed the model calculations of dust emissions dispersion and establishment of the areas of fine dust РМ 10 and РМ 2.5 distribution. It was found that the dust emissions of fine powder fractions PM10 and PM2.5 are dispersed over large distances and beyond the border of the industrial site of the enterprise. The population living near the enterprise is exposed to the risk of diseases associated with dust exposure. Data are transferred to the economic entity to make decisions on the measures to minimize the risks. Exposure and risks indicators on the health are used to provide named patient health and preventive care to the citizens living in the area of negative impact of the facility.

Keywords: dust emissions, еxposure assessment, PM 10, PM 2.5

Procedia PDF Downloads 241

Authors: Jaydip De

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Urban parks are open places, green fields and riverside gardens usually maintained by public or private authorities, or eventually by both jointly; and utilized for a multidimensional purpose by the citizens. These parks are indeed the lung of urban centers. In urban socio-environmental setup, parks are the nucleus of social integration, community building, and physical development. In contemporary cities, these green places seem to perform as the panacea of congested, complex and stressful urban life. The alarmingly increasing urban population and the resultant congestion of high-rises are making life wearisome in neo-liberal cities. This has made the citizen always quest for open space and fresh air. In such a circumstance, the mere existence of parks is not capable of satisfying the growing aspirations. Therefore in this endeavour, a structured attempt is so made to empirically identify the utility, visitors’ satisfaction, and future needs through the cases of two urban parks of Kolkata Metropolitan Area, India. This study is principally based upon primary information collected through visitors’ perception survey conducted at the Chinsurah ground and Chandernagore strand. The correlation between different utility categories is identified and analyzed systematically. At the same time, indices like Weighted Satisfaction Score (WSS), Facility wise Satisfaction Index (FSI), Urban Park Satisfaction Index (UPSI) and Urban Park Necessity Index (UPNI) are advocated to quantify the visitors’ satisfaction and future necessities. It is explored that the most important utilities are passive in nature. Simultaneously, satisfaction levels of visitors are average, and their requirements are centred on the daily needs of the next generation, i.e., the children. Further, considering the visitors’ opinion planning measures are promulgated for holistic development of urban parks to revitalize sustainability of citified life.

Keywords: citified life, future needs, visitors’ satisfaction, urban parks, utility

Procedia PDF Downloads 156

Authors: Paula Lopez-Arce, Hector Altamirano, Dimitrios Rovas, James Berry, Bryan Hindle, Steven Hodgson

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Efficient mould remediation and accurate moisture diagnostics leading to condensation and mould growth in dwellings are largely untapped. Number of factors are contributing to the rising trend of excessive moisture in homes mainly linked with modern living, increased levels of occupation and rising fuel costs, as well as making homes more energy efficient. Environmental monitoring by means of data collection though loggers sensors and survey forms has been performed in a range of buildings from different UK regions. Air and surface temperature and relative humidity values of residential areas affected by condensation and/or mould issues were recorded. Additional measurements were taken through different trials changing type, location, and position of loggers. In some instances, IR thermal images and ventilation rates have also been acquired. Results have been interpreted together with environmental key parameters by processing and connecting data from loggers and survey questionnaires, both in buildings with and without moisture issues. Monitoring exercises carried out during Winter and Spring time show the importance of developing and following accurate protocols for guidance to obtain consistent, repeatable and comparable results and to improve the performance of environmental monitoring. A model and a protocol are being developed to build a diagnostic tool with the goal of performing a simple but precise residential atmospheric moisture diagnostics to distinguish the cause entailing condensation and mould generation, i.e., ventilation, insulation or heating systems issue. This research shows the relevance of monitoring and processing environmental data to assign moisture risk levels and determine the origin of condensation or mould when dealing with a building atmospheric moisture excess.

Keywords: environmental monitoring, atmospheric moisture, protocols, mould

Procedia PDF Downloads 125

Authors: Ai Serizawa, Kotaro Mori, Takahiro Ishizaki

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Al alloys have been used as advanced structural materials in automobile and railway industries because of excellent physical and mechanical properties such as low density, good heat conductivity, and high specific strength. Their low corrosion resistance, however, limits their use in the corrosive environment. To improve the corrosion resistance of the Al alloys, the development of a novel coating technology has been highly desirable. Chemical conversion methods using layered double hydroxide (LDH) have attracted much attention because the LDH can suppress corrosion reaction due to their trapping ability of corrosive anions such as Cl- between layers. In this presentation, we report on a novel preparation method of AlOOH film containing Mg-Al layered double hydroxide (LDH) on Al alloy by steam coating. The corrosion resistance of the composite film including LDH was especially focused. Al-Mg-Si alloy was used as the substrate. The substrates were ultrasonically cleaned in ethanol for 10 min. The cleaned substrates were set in the autoclave with a 100 mL capacity. 20 ml of ultrapure water was located at the bottom of the autoclave to produce steam. The autoclave was heated up to a temperature of 100 to 200 °C, and then held at this temperature for up to 48 h, and was subsequently cooled naturally to room temperature, resulting in the formation of anticorrosive films on Al alloys. The resultant films were characterized by XRD, FT-IR, FE-SEM and electrochemical measurements. FE-SEM image of film surface treated at 180 °C for 48 h demonstrated that needle-like nanostructure was densely formed on the surface. XRD patterns revealed that the film formed on the Al alloys by steam coating was composed of crystal AlOOH and Mg-Al LDH. The corrosion resistance of the film was evaluated using electrochemical measurements. The potentiodynamic polarization curves of the film coated and uncoated substrates of Al-Mg-Si alloy after immersion in the 5 wt% NaCl aqueous solution for 30 min revealed that the corrosion current density, jcorr, of the film coated sample decreased by more than two orders of magnitude as compared to the uncoated sample, indicating that the corrosion resistance of the substrates of Al-Mg-Si alloy were improved by the formation of the anticorrosive film via steam coating.

Keywords: aluminum alloy, boehmite, corrosion resistance, steam process

Procedia PDF Downloads 276

Authors: Lemuel David

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The importance of the Micro, Small, and Medium Enterprises sector is well recognized for its legitimate contribution to the Macroeconomic objectives of the Republic of Liberia, like generation of employment, input t, exports, and enhancing entrepreneurship. Right now, Medium and Small enterprises accounts for about 99 percent of the industrial units in the country, contributing 60 percent of the manufacturing sector output and approximately one-third of the nation’s exports. The role of various financial institutions like ECO bank and Non-financial Institutions like Bearch Limited support promoting the growth of Micro, Small, and Medium Enterprises is unique. A small enterprise or entrepreneur gets many types of assistance from different institutions for varied purposes in the course of his entrepreneurial journey. This paper focuses on the factors related to financial institutional support and non-financial institutional support entrepreneurs to the growth of Medium and Small enterprises in the Republic of Liberia. The significance of this paper is to support Policy and Institutional Support for Medium and Small enterprises to know the views of entrepreneurs about financial and non-financial support systems in the Republic of Liberia. This study was carried out through a survey method, with the use of questionnaires. The population for this study consisted of all registered Medium and Small enterprises which have been registered during the years 2004-2014 in the republic of Liberia. The sampling method employed for this study was a simple random technique and determined a sample size of 400. Data for the study was collected using a standard questionnaire. The questionnaire consisted of two parts: the first part consisted of questions on the profile of the respondents. The second part covers (1) financial, promotional factors and (2) non-financial promotional factors. The results of the study are based on financial and non-financial supporting activities provided by institutions to Medium and Small enterprises. After investigation, it has been found that there is no difference in the support given by Financial Institutions and non-financial Institutions. Entrepreneurs perceived “collateral-free schemes and physical infrastructure support factors are highest contributing to entry and growth of Medium and Small enterprises.

Keywords: micro, small, and medium enterprises financial institutions, entrepreneurship

Procedia PDF Downloads 78

Authors: Marie Fouet, Olivier Maire, Cécile Masse, Hugues Blanchet, Salomé Coignard, Nicolas Lavesque, Guillaume Bernard

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Exacerbated by global change, extreme climatic events such as atmospheric and marine heat waves may interact with the spread of non-indigenous species and their associated impacts on marine ecosystems. Since the 1970’s, the introduction of non-indigenous species due to oyster exchanges has been numerous. Among them, the Asian date mussel Arcuatula senhousia has colonized a large number of ecosystems worldwide (e.g., California, New Zealand, Italy). In these places, A.senhousia led to important habitat modifications in the benthic compartment through physical, biological, and biogeochemical effects associated with the development of dense mussel populations. In Arcachon Bay (France), a coastal lagoon of the French Atlantic and hotspot of oyster farming, abundances of A. senhousia recently increased, following a lag time of ca. 20 years since the first record of the species in 2002. Here, we addressed the potential effects of the interaction between A. senhousia invasion and heatwave intensity on ecosystem functioning within an intertidal mudflat. More precisely, two realistic intensities (“High” and “Severe”) of combined marine and atmospheric heatwaves have been simulated in an experimental tidal mesocosm system onto which naturally varying densities of A. senhousia and associated benthic communities were exposed in sediment cores collected in situ. Following a six-day exposure, community-scale responses were assessed by measuring benthic metabolism (oxygen and nutrient fluxes) in each core. Results show that besides significantly enhanced benthic metabolism with increasing heatwave intensity, mussel density clearly mediated the magnitude of the community-scale response, thereby highlighting the importance of understanding the interactive effects of environmental stressors co-occurring with non-indigenous species and their dependencies for a better assessment of their impacts.

Keywords: arcuatula senhousia, benthic habitat, ecosystem functioning, heatwaves, metabolism

Procedia PDF Downloads 46

Authors: Tuaumelsan Shumye Gebre, Shimelis Admassu Emire, Simon Okomo Aloo, Ramachandran Chelliah, Deog-Hwan Oh

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This study investigates the fermentation of cereal substrates, based on the Ethiopian traditional beverage borde, using probiotic strains of Pediococcus acidilactici WS07 and Saccharomyces cerevisiae AM18 used singly and in co-culture. The pH and titratable acidity, microbial growth dynamics, fermentable sugars profile, volatile organic compounds, total flavonoids content, total phenolic content, antioxidant activity, pancreatic lipase and α-glucosidase inhibition were analyzed. The viability of every tested strain remained higher than 7 log CFU/mL, satisfying the requirements suggested for probiotic food items. The formation of organic acids is what caused the pH to decrease from roughly 6.6 to 3.8, yet this had no effect on the viability of the microorganisms. The fermentation process, involving P. acidilactici WS07 and S. cerevisiae AM18, led to the utilization of initial carbohydrates, production of organic acids, and generation of volatile compounds that enhance flavor and aroma. Ethanol and glycerol concentrations increased during fermentation, particularly in co-culture assays, contributing to the sensory qualities and stability of the beverages. The primary organic acids generated during fermentation were lactic and acetic acids. A total of 22 volatile substances, such as acids, alcohols, aldehydes, esters, ketones, and other substances, were found. Furthermore, the study demonstrates that fermentation of maize and sorghum with P. acidilactici WS07 and S. cerevisiae AM18 enhances the antioxidant activity and inhibition of pancreatic lipase and α-glucosidase, suggesting potential benefits in managing obesity and diabetes. Therefore, co-cultivating S. cerevisiae AM18 and P. acidilactici WS07 in cereal fermentation led to the successful production of probiotic drinks.

Keywords: probiotic beverage, pediococcus acidilactici, saccharomyces cerevisiae, volatile compounds

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Authors: Vishal Pareek, Shubham Gupta, Sushil Chandra Jain

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With increasing high-speed computation demand the power consumption, heat dissipation and chip size issues are posing challenges for logic design with conventional technologies. Recovery of bit loss and bit errors is other issues that require reversibility and fault tolerance in the computation. The reversible computing is emerging as an alternative to conventional technologies to overcome the above problems and helpful in a diverse area such as low-power design, nanotechnology, quantum computing. Bit loss issue can be solved through unique input-output mapping which require reversibility and bit error issue require the capability of fault tolerance in design. In order to incorporate reversibility a number of combinational reversible logic based circuits have been developed. However, very few sequential reversible circuits have been reported in the literature. To make the circuit fault tolerant, a number of fault model and test approaches have been proposed for reversible logic. In this paper, we have attempted to incorporate fault tolerance in sequential reversible building blocks such as D flip-flop, T flip-flop, JK flip-flop, R-S flip-flop, Master-Slave D flip-flop, and double edge triggered D flip-flop by making them parity preserving. The importance of this proposed work lies in the fact that it provides the design of reversible sequential circuits completely testable for any stuck-at fault and single bit fault. In our opinion our design of reversible building blocks is superior to existing designs in term of quantum cost, hardware complexity, constant input, garbage output, number of gates and design of online testable D flip-flop have been proposed for the first time. We hope our work can be extended for building complex reversible sequential circuits.

Keywords: parity preserving gate, quantum computing, fault tolerance, flip-flop, sequential reversible logic

Procedia PDF Downloads 530

Authors: Seyed-Ali Sadegh-Zadeh, Mahboobe Bahrami, Sahar Ahmadi, Seyed-Yaser Mousavi, Hamed Atashbar, Amir M. Hajiyavand

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This paper presents an investigation into the concept of neural reshaping, which is crucial for achieving strong artificial intelligence through the development of AI algorithms with very high plasticity. By examining the plasticity of both human and artificial neural networks, the study uncovers groundbreaking insights into how these systems adapt to new experiences and situations, ultimately highlighting the potential for creating advanced AI systems that closely mimic human intelligence. The uniqueness of this paper lies in its comprehensive analysis of the neural reshaping process in both human and artificial intelligence systems. This comparative approach enables a deeper understanding of the fundamental principles of neural plasticity, thus shedding light on the limitations and untapped potential of both human and AI learning capabilities. By emphasizing the importance of neural reshaping in the quest for strong AI, the study underscores the need for developing AI algorithms with exceptional adaptability and plasticity. The paper's findings have significant implications for the future of AI research and development. By identifying the core principles of neural reshaping, this research can guide the design of next-generation AI technologies that can enhance human and artificial intelligence alike. These advancements will be instrumental in creating a new era of AI systems with unparalleled capabilities, paving the way for improved decision-making, problem-solving, and overall cognitive performance. In conclusion, this paper makes a substantial contribution by investigating the concept of neural reshaping and its importance for achieving strong AI. Through its in-depth exploration of neural plasticity in both human and artificial neural networks, the study unveils vital insights that can inform the development of innovative AI technologies with high adaptability and potential for enhancing human and AI capabilities alike.

Keywords: neural plasticity, brain adaptation, artificial intelligence, learning, cognitive reshaping

Procedia PDF Downloads 31

Authors: Ana C. Ramos Valdivia, Ileana Vera-Reyes, Ariana A. Huerta-Heredia

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The conditions of biotic and abiotic stress in plants can lead to the generation of high amounts of reactive oxygen species (ROS), which leads through a signaling cascade and second messengers to different antioxidant defense responses including the production of secondary metabolites. A limited number of species of plants like Uncaria tomentosa (cat claw) typical of the Amazon region produce monoterpenoid oxindole alkaloids (MOA) such as isopteropodine, mitraphylline, rhynchophylline and its isomers. Moreover, in cultivated roots, the glucoindole alkaloid 3α-dihydrocadambine (DHC) is also accumulated. Several studies have demonstrated that MAO has antioxidant properties and possess important pharmacological activities such as antitumor and immunostimulant while DHC, has hypotensive and hypolipidemic effects. In order the study the regulatory concerns operating in MAO production, the links between oxidative stress and antioxidant alkaloid production in U. tomentosa root cultures were examined. Different amount of hydrogen peroxide between 0.2 -1.0 mM was added to 12 days old roots cultures showing that, this substance had a differential effect on the production of DHC and MOA whereas the viability remained in 80% after six days. Addition of 0.2 mM hydrogen peroxide increased approximately 65% MAO and DHC production (0,540 ± 0.018 and 0.618 ± 0.029 mg per g dry weight, respectively) relative to the control. On contrast, after the addition of 0.6 mM and 1 mM hydrogen peroxide, DHC accumulation into the roots gradually decreased to 53% and 93% respectively, without changes in MAO concentration, which was in relation to a twice increase of the intracellular hydrogen peroxide content. On the other hand, concentrations of DHC (0.1, 0.5 and 1.0 mM in methanol) demonstrated free-radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. The calculated IC50 for all tested concentrations was 0.180 mg per ml (0.33 mM) while the calculated TE50 was 276 minutes. Our results suggest that U. tomentosa root cultures both MAO and DHC have antioxidant capacities and respond to oxidative stress with a stimulation of their production; however, in presence of a higher concentration of ROS into the roots, DHC could be oxidized.

Keywords: monoterpenoid indole alkaloid, oxidative stress, root cultures, uncaria tomentosa

Procedia PDF Downloads 167

Authors: Ebuwa Osagie, Chet Biliyok, Yeung Hoi

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Regeneration energy requirement and ways to reduce it is the main aim of most CO2 capture researches currently being performed and thus, post-combustion carbon capture (PCC) option is identified to be the most suitable for the natural gas-fired power plants. From current research and development (R&D) activities worldwide, two main areas are being examined in order to reduce the regeneration energy requirement of amine-based PCC, namely: (a) development of new solvents with better overall performance than 30wt% monoethanolamine (MEA) aqueous solution, which is considered as the base-line solvent for solvent-based PCC, (b) Integration of the PCC Plant to the power plant. In scaling-up a PCC pilot plant to the size required for a commercial-scale natural gas-fired power plant, process modelling and simulation is very essential. In this work, an integrated process made up of a 482MWe natural gas-fired power plant, an MEA-based PCC plant which is developed and validated has been modelled and simulated. The PCC plant has four absorber columns and a single stripper column, the modelling and simulation was performed with Aspen Plus® V8.4. The gas turbine, the heat recovery steam generator and the steam cycle were modelled based on a 2010 US DOE report, while the MEA-based PCC plant was modelled as a rate-based process. The scaling of the amine plant was performed using a rate based calculation in preference to the equilibrium based approach for 90% CO2 capture. The power plant was integrated to the PCC plant in three ways: (i) flue gas stream from the power plant which is divided equally into four stream and each stream is fed into one of the four absorbers in the PCC plant. (ii) Steam draw-off from the IP/LP cross-over pipe in the steam cycle of the power plant used to regenerate solvent in the reboiler. (iii) Condensate returns from the reboiler to the power plant. The integration of a PCC plant to the NGCC plant resulted in a reduction of the power plant output by 73.56 MWe and the net efficiency of the integrated system is reduced by 7.3 % point efficiency. A secondary aim of this study is the parametric studies which have been performed to assess the impacts of natural gas on the overall performance of the integrated process and this is achieved through investigation of the capture efficiencies.

Keywords: natural gas-fired, power plant, MEA, CO2 capture, modelling, simulation

Procedia PDF Downloads 432