Search results for: software testing life cycle
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 15072

Search results for: software testing life cycle

14712 Using Wiki for Enhancing the Knowledge Transfer to Newcomers: An Experience Report

Authors: Hualter Oliveira Barbosa, Raquel Feitosa do Vale Cunha, Erika Muniz dos Santos, Fernanda Belmira Souza, Fabio Sousa, Luis Henrique Pascareli, Franciney de Oliveira Lima, Ana Cláudia Reis da Silva, Christiane Moreira de Almeida

Abstract:

Software development is intrinsic human-based knowledge-intensive. Due to globalization, software development has become a complex challenge and we usually face barriers related to knowledge management, team building, costly testing processes, especially in distributed settings. For this reason, several approaches have been proposed to minimize barriers caused by geographic distance. In this paper, we present as we use experimental studies to improve our knowledge management process using the Wiki system. According to the results, it was possible to identify learning preferences from our software projects leader team, organize and improve the learning experience of our Wiki and; facilitate collaboration by newcomers to improve Wiki with new contents available in the Wiki.

Keywords: mobile product, knowledge transfer, knowledge management process, wiki, GSD

Procedia PDF Downloads 149
14711 Life Cycle Assessment of Mass Timber Structure, Construction Process as System Boundary

Authors: Mahboobeh Hemmati, Tahar Messadi, Hongmei Gu

Abstract:

Today, life cycle assessment (LCA) is a leading method in mitigating the environmental impacts emerging from the building sector. In this paper, LCA is used to quantify the Green House Gas (GHG) emissions during the construction phase of the largest mass timber residential structure in the United States, Adohi Hall. This building is a 200,000 square foot 708-bed complex located on the campus of the University of Arkansas. The energy used for buildings’ operation is the most dominant source of emissions in the building industry. Lately, however, the efforts were successful at increasing the efficiency of building operation in terms of emissions. As a result, the attention is now shifted to the embodied carbon, which is more noticeable in the building life cycle. Unfortunately, most of the studies have, however, focused on the manufacturing stage, and only a few have addressed to date the construction process. Specifically, less data is available about environmental impacts associated with the construction of mass timber. This study presents, therefore, an assessment of the environmental impact of the construction processes based on the real and newly built mass timber building mentioned above. The system boundary of this study covers modules A4 and A5 based on building LCA standard EN 15978. Module A4 includes material and equipment transportation. Module A5 covers the construction and installation process. This research evolves through 2 stages: first, to quantify materials and equipment deployed in the building, and second, to determine the embodied carbon associated with running equipment for construction materials, both transported to, and installed on, the site where the edifice is built. The Global Warming Potential (GWP) of the building is the primary metric considered in this research. The outcomes of this study bring to the front a better understanding of hotspots in terms of emission during the construction process. Moreover, the comparative analysis of the mass timber construction process with that of a theoretically similar steel building will enable an effective assessment of the environmental efficiency of mass timber.

Keywords: construction process, GWP, LCA, mass timber

Procedia PDF Downloads 143
14710 A Simplified, Low-Cost Mechanical Design for an Automated Motorized Mechanism to Clean Large Diameter Pipes

Authors: Imad Khan, Imran Shafi, Sarmad Farooq

Abstract:

Large diameter pipes, barrels, tubes, and ducts are used in a variety of applications covering civil and defense-related technologies. This may include heating/cooling networks, sign poles, bracing, casing, and artillery and tank gun barrels. These large diameter assemblies require regular inspection and cleaning to increase their life and reduce replacement costs. This paper describes the design, development, and testing results of an efficient yet simplified, low maintenance mechanical design controlled with minimal essential electronics using an electric motor for a non-technical staff. The proposed solution provides a simplified user interface and an automated cleaning mechanism that requires a single user to optimally clean pipes and barrels in the range of 105 mm to 203 mm caliber. The proposed system employs linear motion of specially designed brush along the barrel using a chain of specific strength and a pulley anchor attached to both ends of the barrel. A specially designed and manufactured gearbox is coupled with an AC motor to allow movement of contact brush with high torque to allow efficient cleaning. A suitably powered AC motor is fixed to the front adapter mounted on the muzzle side whereas the rear adapter has a pulley-based anchor mounted towards the breach block in case of a gun barrel. A mix of soft nylon and hard copper bristles-based large surface brush is connected through a strong steel chain to motor and anchor pulley. The system is equipped with limit switches to auto switch the direction when one end is reached on its operation. The testing results based on carefully established performance indicators indicate the superiority of the proposed user-friendly cleaning mechanism vis-à-vis its life cycle cost.

Keywords: pipe cleaning mechanism, limiting switch, pipe cleaning robot, large pipes

Procedia PDF Downloads 84
14709 Visualizing Class Metrics and Object Calls for Software Systems

Authors: Mohammad Alnabhan, Awni Hammouri, Mustafa Hammad, Anas Al-Badareen, Omamah Al-Thnebat

Abstract:

Software visualization is one of the main techniques used to simplify the presentation of software systems and enhance their understandability. It is used to present the software system in a visual manner using simple, clear and meaningful symbols. This study proposes a new 2D software visualization approach. In this approach, each class is represented by rectangle, the name of the class placed above the rectangle, the size of class (Line of Code) represented by the height of the rectangle. The methods and the attributes are represented by circles and triangles respectively. The relationships among classes correspond to arrows. The proposed visualization approach was evaluated in terms of applicability and efficiency. Results have confirmed successful implementation of the proposed approach, and its ability to provide a simple and effective graphical presentation of extracted software components and properties.

Keywords: software visualization, software metrics, calling relationships, 2D graphs

Procedia PDF Downloads 171
14708 Modeling of Thermally Induced Acoustic Emission Memory Effects in Heterogeneous Rocks with Consideration for Fracture Develo

Authors: Vladimir A. Vinnikov

Abstract:

The paper proposes a model of an inhomogeneous rock mass with initially random distribution of microcracks on mineral grain boundaries. It describes the behavior of cracks in a medium under the effect of thermal field, the medium heated instantaneously to a predetermined temperature. Crack growth occurs according to the concept of fracture mechanics provided that the stress intensity factor K exceeds the critical value of Kc. The modeling of thermally induced acoustic emission memory effects is based on the assumption that every event of crack nucleation or crack growth caused by heating is accompanied by a single acoustic emission event. Parameters of the thermally induced acoustic emission memory effect produced by cyclic heating and cooling (with the temperature amplitude increasing from cycle to cycle) were calculated for several rock texture types (massive, banded, and disseminated). The study substantiates the adaptation of the proposed model to humidity interference with the thermally induced acoustic emission memory effect. The influence of humidity on the thermally induced acoustic emission memory effect in quasi-homogeneous and banded rocks is estimated. It is shown that such modeling allows the structure and texture of rocks to be taken into account and the influence of interference factors on the distinctness of the thermally induced acoustic emission memory effect to be estimated. The numerical modeling can be used to obtain information about the thermal impacts on rocks in the past and determine the degree of rock disturbance by means of non-destructive testing.

Keywords: degree of rock disturbance, non-destructive testing, thermally induced acoustic emission memory effects, structure and texture of rocks

Procedia PDF Downloads 239
14707 Design of Structural Health Monitoring System for a Damaged Reinforced Concrete Bridge

Authors: Muhammad Fawad

Abstract:

Monitoring and structural health assessment are the primary requirements for the performance evaluation of damaged bridges. This paper highlights the case study of a damaged Reinforced Concrete (RC) bridge structure where the Finite element (FE) modelling of this structure was done using the material properties extracted by the in-situ testing. Analysis was carried out to evaluate the bridge damage. On the basis of FE analysis results, this study proposes a proper Structural Health Monitoring (SHM) system that will extend the life cycle of the bridge with minimal repair costs and reduced risk of failure. This system is based on the installation of three different types of sensors: Liquid Levelling sensors (LLS) for measurement of vertical displacement, Distributed Fiber Optic Sensors (DFOS) for crack monitoring, and Weigh in Motion (WIM) devices for monitoring of moving loads on the bridge.

Keywords: bridges, reinforced concrete, finite element method, structural health monitoring, sensors

Procedia PDF Downloads 77
14706 Intelligent Software Architecture and Automatic Re-Architecting Based on Machine Learning

Authors: Gebremeskel Hagos Gebremedhin, Feng Chong, Heyan Huang

Abstract:

Software system is the combination of architecture and organized components to accomplish a specific function or set of functions. A good software architecture facilitates application system development, promotes achievement of functional requirements, and supports system reconfiguration. We describe three studies demonstrating the utility of our architecture in the subdomain of mobile office robots and identify software engineering principles embodied in the architecture. The main aim of this paper is to analyze prove architecture design and automatic re-architecting using machine learning. Intelligence software architecture and automatic re-architecting process is reorganizing in to more suitable one of the software organizational structure system using the user access dataset for creating relationship among the components of the system. The 3-step approach of data mining was used to analyze effective recovery, transformation and implantation with the use of clustering algorithm. Therefore, automatic re-architecting without changing the source code is possible to solve the software complexity problem and system software reuse.

Keywords: intelligence, software architecture, re-architecting, software reuse, High level design

Procedia PDF Downloads 93
14705 The Legal Regulation of Direct-to-Consumer Genetic Testing In South Africa

Authors: Amy Gooden

Abstract:

Despite its prevalence, direct-to-consumer genetic testing (DTC-GT) remains under-investigated in South Africa (SA), and the issue of regulation is yet to be examined. Therefore, this research maps the current legal landscape relating to DTC-GT in SA through a legal analysis of the extant law relevant to the industry and the issues associated therewith – with the intention of determining if and how DTC-GT is legally governed. This research analyses: whether consumers are legally permitted to collect their saliva; whether DTC-GT are medical devices; licensing, registering, and advertising; importing and exporting; and genetic research conducted by companies.

Keywords: direct-to-consumer genetic testing, genetic testing, health, law, regulation, South Africa

Procedia PDF Downloads 111
14704 Implications of Fuel Reloading in Heterogeneous Thorium-Based Fuel Designs for Improved Fuel Cycle Characteristics

Authors: Hendrik Bernard Van Der Walt, Frik Van Niekerk

Abstract:

Fuel models render a reduction in BOL when thorium is added to a reactor core. Thorium emulates the role of a fertile poison, and is beneficial for reducing beginning of cycle (BOC) excess reactivity. In spite of the build-up of 233U over the duration of a fuel cycle, the effects of fuel reloading have a significant impact on fuel viability, especially in the case of heterogeneous thorium-based fuels. The most common practice of compensating for the reduction of BOC reactivity is the addition of fissile isotopes (uranium fuel with increased enrichment or plutonium). This study introduces a heterogeneous thorium-based fuel with minimal fissile isotope additions. A pseudo reloading scheme was developed for numerical simulations of an infinite reactor based on the North-Anna 1 reactor operating in Virginia, USA. Use of this reloading pattern allows new thorium-based fuel to be loaded into the reactor model as part of a phasing in strategy at the end of any conventional reactor cycle. Results demonstrate the effects of thorium-based fuel on fuel cycle characteristics such as fuel cycle length, neutron economy and material matrix. Application of the above mentioned approach delivered promising results and presents a heterogeneous thorium-based fuel which could replace conventional fuel of typical, currently operating (or future) reactors without the need for expensive reactor redesign or fuel recycling strategies.

Keywords: nuclear fuel, nuclear characteristics, nuclear fuel cycle, thorium-based fuel, heterogeneous design, fuel reloading

Procedia PDF Downloads 111
14703 FreGsd: A Framework for Golbal Software Requirement Engineering

Authors: Alsahli Abdulaziz Abdullah, Hameed Ullah Khan

Abstract:

Software development nowadays is more and more using global ways of development instead of normal development enviroment where development occur in one location. This paper is a aimed to propose a Requirement Engineering framework to support Global Software Development environment with regards to all requirment engineering activities from elicitation to fially magning requirment change. Global software enviroment is more and more gaining better reputation in software developmet with better quality is resulting from developing in this eviroment yet with lower cost.However, failure rate developing in this enviroment is high due to inapproprate requirment development and managment.This paper will add to the software engineering development envrioments discipline and many developers in GSD will benefit from it.

Keywords: global software development environment, GSD, requirement engineering, FreGsd, computer engineering

Procedia PDF Downloads 509
14702 Human Immunodeficiency Virus (HIV) Test Predictive Modeling and Identify Determinants of HIV Testing for People with Age above Fourteen Years in Ethiopia Using Data Mining Techniques: EDHS 2011

Authors: S. Abera, T. Gidey, W. Terefe

Abstract:

Introduction: Testing for HIV is the key entry point to HIV prevention, treatment, and care and support services. Hence, predictive data mining techniques can greatly benefit to analyze and discover new patterns from huge datasets like that of EDHS 2011 data. Objectives: The objective of this study is to build a predictive modeling for HIV testing and identify determinants of HIV testing for adults with age above fourteen years using data mining techniques. Methods: Cross-Industry Standard Process for Data Mining (CRISP-DM) was used to predict the model for HIV testing and explore association rules between HIV testing and the selected attributes among adult Ethiopians. Decision tree, Naïve-Bayes, logistic regression and artificial neural networks of data mining techniques were used to build the predictive models. Results: The target dataset contained 30,625 study participants; of which 16, 515 (53.9%) were women. Nearly two-fifth; 17,719 (58%), have never been tested for HIV while the rest 12,906 (42%) had been tested. Ethiopians with higher wealth index, higher educational level, belonging 20 to 29 years old, having no stigmatizing attitude towards HIV positive person, urban residents, having HIV related knowledge, information about family planning on mass media and knowing a place where to get testing for HIV showed an increased patterns with respect to HIV testing. Conclusion and Recommendation: Public health interventions should consider the identified determinants to promote people to get testing for HIV.

Keywords: data mining, HIV, testing, ethiopia

Procedia PDF Downloads 467
14701 Building Energy Modeling for Networks of Data Centers

Authors: Eric Kumar, Erica Cochran, Zhiang Zhang, Wei Liang, Ronak Mody

Abstract:

The objective of this article was to create a modelling framework that exposes the marginal costs of shifting workloads across geographically distributed data-centers. Geographical distribution of internet services helps to optimize their performance for localized end users with lowered communications times and increased availability. However, due to the geographical and temporal effects, the physical embodiments of a service's data center infrastructure can vary greatly. In this work, we first identify that the sources of variances in the physical infrastructure primarily stem from local weather conditions, specific user traffic profiles, energy sources, and the types of IT hardware available at the time of deployment. Second, we create a traffic simulator that indicates the IT load at each data-center in the set as an approximator for user traffic profiles. Third, we implement a framework that quantifies the global level energy demands using building energy models and the traffic profiles. The results of the model provide a time series of energy demands that can be used for further life cycle analysis of internet services.

Keywords: data-centers, energy, life cycle, network simulation

Procedia PDF Downloads 121
14700 Concrete-Wall-Climbing Testing Robot

Authors: S. Tokuomi, K. Mori, Y. Tsuruzono

Abstract:

A concrete-wall-climbing testing robot, has been developed. This robot adheres and climbs concrete walls using two sets of suction cups, as well as being able to rotate by the use of the alternating motion of the suction cups. The maximum climbing speed is about 60 cm/min. Each suction cup has a pressure sensor, which monitors the adhesion of each suction cup. The impact acoustic method is used in testing concrete walls. This robot has an impact acoustic device and four microphones for the acquisition of the impact sound. The effectiveness of the impact acoustic system was tested by applying it to an inspection of specimens with artificial circular void defects. A circular void defect with a diameter of 200 mm at a depth of 50 mm was able to be detected. The weight and the dimensions of the robot are about 17 kg and 1.0 m by 1.3 m, respectively. The upper limit of testing is about 10 m above the ground due to the length of the power cable.

Keywords: concrete wall, nondestructive testing, climbing robot, impact acoustic method

Procedia PDF Downloads 628
14699 Designing a Tool for Software Maintenance

Authors: Amir Ngah, Masita Abdul Jalil, Zailani Abdullah

Abstract:

The aim of software maintenance is to maintain the software system in accordance with advancement in software and hardware technology. One of the early works on software maintenance is to extract information at higher level of abstraction. In this paper, we present the process of how to design an information extraction tool for software maintenance. The tool can extract the basic information from old program such as about variables, based classes, derived classes, objects of classes, and functions. The tool have two main part; the lexical analyzer module that can read the input file character by character, and the searching module which is user can get the basic information from existing program. We implemented this tool for a patterned sub-C++ language as an input file.

Keywords: extraction tool, software maintenance, reverse engineering, C++

Procedia PDF Downloads 457
14698 Life Cycle Analysis (LCA) for Transportation of Cross-Laminated Timber (CLT) Panels Comparing Two Origin Points of Supply

Authors: Mahboobeh Hemmati, Tahar Messadi, Hongmei Gu

Abstract:

This overall research is targeted at the assessment of the new CLT-built Adohi Hall residential building located on the campus of the University of Arkansas in Fayetteville, Arkansas. The purpose of the Life Cycle Assessment (LCA) study is to analyze the environmental impacts resulting from the transportation route of the Austrian imported CLT to the construction site with those of the CLT assumed to be originating from Conway, Arkansas. The Global Warming Potential (GWP) of CLT from Europe (Styria-Graz in Austria) to the site was first investigated. The results were then compared with the GWP of the CLT produced in Conway, Arkansas. The impacts of each scenario, using the Ecoinvent database, are then calculated and compared against each other to find the most environmentally efficient scenario in terms of global warming impacts. The quantification of GWP is associated with different transportation systems, water, road, and rail. Obtained through comparison, the findings reveal that the use of local materials is more efficient. In addition, transportation by water produces less Greenhouse Gas (GHG) emission in comparison to freight transportation by rail and road. Thus, besides the travel distance, the utilized transportation system is still a significant factor and should be seriously considered in making decisions for moving materials.

Keywords: comparative analysis, GWP, LCA, transportation

Procedia PDF Downloads 218
14697 Aerodynamic Analysis and Design of Banners for Remote-Controlled Aircraft

Authors: Peyman Honarmandi, Mazen Alhirsh

Abstract:

Banner towing is a major form of advertisement. It consists of a banner showing a logo or a selection of words or letters being towed by an aircraft. Traditionally bush planes have been used to tow banners given their high thrust capabilities; however, with the development of remote-controlled (RC) aircraft, they could be a good replacement as RC planes mitigate the risk of human life and can be easier to operate. This paper studies the best banner design to be towed by an RC aircraft. This is done by conducting wind tunnel testing on an array of banners with different materials and designs. A pull gauge is used to record the drag force during testing, which is then used to calculate the coefficient of drag, Cd. The testing results show that the best banner design would be a hybrid design with a solid and mesh material. The design with the lowest Cd of 0.082 was a half ripstop nylon half polyester mesh design. On the other hand, the design with the highest Cd of 0.305 involved incorporating a tail chute to decrease fluttering.

Keywords: aerodynamics of banner, banner design, banner towing, drag coefficients of banner, RC aircraft banner

Procedia PDF Downloads 216
14696 Effects of Operating Conditions on Creep Life of Industrial Gas Turbine

Authors: Enyia James Diwa, Dodeye Ina Igbong, Archibong Eso Archibong

Abstract:

The creep life of an industrial gas turbine is determined through a physics-based model used to investigate the high pressure temperature (HPT) of the blade in use. A performance model was carried out via the Cranfield University TURBOMATCH simulation software to size the blade and to determine the corresponding stress. Various effects such as radial temperature distortion factor, turbine entry temperature, ambient temperature, blade metal temperature, and compressor degradation on the blade creep life were investigated. The output results show the difference in creep life and the location of failure along the span of the blade enabling better-informed advice for the gas turbine operator.

Keywords: creep, living, performance, degradation

Procedia PDF Downloads 381
14695 ANFIS Based Technique to Estimate Remnant Life of Power Transformer by Predicting Furan Contents

Authors: Priyesh Kumar Pandey, Zakir Husain, R. K. Jarial

Abstract:

Condition monitoring and diagnostic is important for testing of power transformer in order to estimate the remnant life. Concentration of furan content in transformer oil can be a promising indirect measurement of the aging of transformer insulation. The oil gets contaminated mainly due to ageing. The present paper introduces adaptive neuro fuzzy technique to correlate furanic compounds obtained by high performance liquid chromatography (HPLC) test and remnant life of the power transformer. The results are obtained by conducting HPLC test at TIFAC-CORE lab, NIT Hamirpur on thirteen power transformer oil samples taken from Himachal State Electricity Board, India.

Keywords: adaptive neuro fuzzy technique, furan compounds, remnant life, transformer oil

Procedia PDF Downloads 436
14694 Thermodynamic Analysis of Zeotropic Mixture Used in Low Temperature Solar Rankine Cycle with Ejector for Power Generation

Authors: Basma Hamdi, Lakdar Kairouani, Ezzedine Nahdi

Abstract:

The objective of this work is to present a thermodynamic analysis of low temperature solar Rankine cycle with ejector for power generation using zeotropic mixtures. Based on theoretical calculation, effects of zeotropic mixtures compositions on the performance of solar Rankine cycle with ejector are discussed and compared with corresponding pure fluids. Variations of net power output, thermal efficiency were calculating with changing evaporation temperature. The ejector coefficient had analyzed as independent variable. The result show that (R245fa/R152a) has a higher thermal efficiency than using pure fluids.

Keywords: zeotropic mixture, thermodynamic analysis, ejector, low-temperature solar rankine cycle

Procedia PDF Downloads 258
14693 Integrated Design in Additive Manufacturing Based on Design for Manufacturing

Authors: E. Asadollahi-Yazdi, J. Gardan, P. Lafon

Abstract:

Nowadays, manufactures are encountered with production of different version of products due to quality, cost and time constraints. On the other hand, Additive Manufacturing (AM) as a production method based on CAD model disrupts the design and manufacturing cycle with new parameters. To consider these issues, the researchers utilized Design For Manufacturing (DFM) approach for AM but until now there is no integrated approach for design and manufacturing of product through the AM. So, this paper aims to provide a general methodology for managing the different production issues, as well as, support the interoperability with AM process and different Product Life Cycle Management tools. The problem is that the models of System Engineering which is used for managing complex systems cannot support the product evolution and its impact on the product life cycle. Therefore, it seems necessary to provide a general methodology for managing the product’s diversities which is created by using AM. This methodology must consider manufacture and assembly during product design as early as possible in the design stage. The latest approach of DFM, as a methodology to analyze the system comprehensively, integrates manufacturing constraints in the numerical model in upstream. So, DFM for AM is used to import the characteristics of AM into the design and manufacturing process of a hybrid product to manage the criteria coming from AM. Also, the research presents an integrated design method in order to take into account the knowledge of layers manufacturing technologies. For this purpose, the interface model based on the skin and skeleton concepts is provided, the usage and manufacturing skins are used to show the functional surface of the product. Also, the material flow and link between the skins are demonstrated by usage and manufacturing skeletons. Therefore, this integrated approach is a helpful methodology for designer and manufacturer in different decisions like material and process selection as well as, evaluation of product manufacturability.

Keywords: additive manufacturing, 3D printing, design for manufacturing, integrated design, interoperability

Procedia PDF Downloads 289
14692 Sensitivity Analysis of the Heat Exchanger Design in Net Power Oxy-Combustion Cycle for Carbon Capture

Authors: Hirbod Varasteh, Hamidreza Gohari Darabkhani

Abstract:

The global warming and its impact on climate change is one of main challenges for current century. Global warming is mainly due to the emission of greenhouse gases (GHG) and carbon dioxide (CO2) is known to be the major contributor to the GHG emission profile. Whilst the energy sector is the primary source for CO2 emission, Carbon Capture and Storage (CCS) are believed to be the solution for controlling this emission. Oxyfuel combustion (Oxy-combustion) is one of the major technologies for capturing CO2 from power plants. For gas turbines, several Oxy-combustion power cycles (Oxyturbine cycles) have been investigated by means of thermodynamic analysis. NetPower cycle is one of the leading oxyturbine power cycles with almost full carbon capture capability from a natural gas fired power plant. In this manuscript, sensitivity analysis of the heat exchanger design in NetPower cycle is completed by means of process modelling. The heat capacity variation and supercritical CO2 with gaseous admixtures are considered for multi-zone analysis with Aspen Plus software. It is found that the heat exchanger design has a major role to increase the efficiency of NetPower cycle. The pinch-point analysis is done to extract the composite and grand composite curve for the heat exchanger. In this paper, relationship between the cycle efficiency and the minimum approach temperature (∆Tmin) of the heat exchanger has also been evaluated.  Increase in ∆Tmin causes a decrease in the temperature of the recycle flue gases (RFG) and an overall decrease in the required power for the recycled gas compressor. The main challenge in the design of heat exchangers in power plants is a tradeoff between the capital and operational costs. To achieve lower ∆Tmin, larger size of heat exchanger is required. This means a higher capital cost but leading to a better heat recovery and lower operational cost. To achieve this, ∆Tmin is selected from the minimum point in the diagrams of capital and operational costs. This study provides an insight into the NetPower Oxy-combustion cycle’s performance analysis and operational condition based on its heat exchanger design.

Keywords: carbon capture and storage, oxy-combustion, netpower cycle, oxy turbine cycles, zero emission, heat exchanger design, supercritical carbon dioxide, oxy-fuel power plant, pinch point analysis

Procedia PDF Downloads 176
14691 Cdk1 Gates Cell Cycle-Dependent tRNA Synthesis by Regulating RNA Polymerase III Activity

Authors: Maricarmen Herrera, Pierre Chymkowitch, Joe Robertson, Jens Eriksson, Jorrit Enserink

Abstract:

tRNA genes are transcribed by RNA polymerase III. During recent years, it has become clear that tDNA transcription fluctuates during the cell cycle. However, the mechanism by which the cell cycle controls the amplitude of tDNA transcription remains unknown. We found that the cyclin Clb5 recruits the cyclin dependent kinase Cdk1 to tRNA genes to sharply increase tRNA synthesis during a brief interval in the cell cycle. We show that Cdk1 promotes the interaction of TFIIIB with TFIIIC, that it stimulates the recruitment of TFIIIC to tRNA genes, that it prevents the formation of an overly stable TFIIIB-tDNA complex and that it augments the dynamics of RNA polymerase III. Furthermore, we identify Bdp1 as a novel Cdk1 substrate, and phosphorylation of Bdp1 is required for the cell cycle-dependent increase in tDNA transcription. In addition, we show that phosphorylation of the Cdk1 substrate Nup60 mediates formation of a Nup60-Nup2 complex at tRNA genes, which is also required for cell cycle-dependent tDNA transcription. Together, our findings indicate that Cdk1 activity gates tRNA synthesis by regulating the dynamics of the TFIIIB-TFIIIC-RNAPIII complex, and that it may promote the formation of a nuclear pore microenvironment conducive to efficient tDNA transcription.

Keywords: Cdk1, cell cycle, RNAPIII machinery, tRNA

Procedia PDF Downloads 160
14690 Ecodesign of Bioplastic Films for Food Packaging and Shelf-life Extension

Authors: Sónia Ribeiro, Diana Farinha, Elsa Pereira, Hélia Sales, Filipa Figueiredo, Rita Pontes, João Nunes

Abstract:

Conventional plastic impacts on Planet, natural resources contamination, human health as well as animals are the most attractive environmental and health attention. The lack of treatment in the end-of-life (EOL) phase and uncontrolled discard allows plastic to be found everywhere in the world. Food waste is increasing significantly, with a final destination to landfills. To face these difficulties, new packaging solutions are needed with the objective of prolonging the shelf-life of products as well as equipment solutions for the development of the mentioned packaging. FLUI project thus presents relevance and innovation to reach a new level of knowledge and industrial development focused in Ecodesign. Industrial equipment field for the manufacture of new packaging solutions based on biodegradable plastics films to apply in the food sector. With lesser environmental impacts and new solutions that make it possible to prevent food waste, reduce the production e consequent poor disposal of plastic of fossil origin. It will be a paradigm shift at different levels, from industry to waste treatment stations, passing through commercial agents and consumers. It can be achieved through the life cycle assessment (LCA) and ecodesign of the products, which integrates the environmental concerns in the design of the product as well as through the entire life cycle. The FLUI project aims to build a piece of new bio-PLA extrusion equipment with the incorporation of bioactive extracts through the production of flexible mono- and multi-layer functional films (FLUI systems). The biofunctional and biodegradable films will prompt the extension of packaged products’ shelf-life, reduce food waste and contribute to reducing the consumption of non-degradable fossil plastics, as well as the use of raw material from renewable sources.

Keywords: food packing, bioplastics, ecodesign, circular economy

Procedia PDF Downloads 61
14689 Thermodynamic Modeling of Three Pressure Level Reheat HRSG, Parametric Analysis and Optimization Using PSO

Authors: Mahmoud Nadir, Adel Ghenaiet

Abstract:

The main purpose of this study is the thermodynamic modeling, the parametric analysis, and the optimization of three pressure level reheat HRSG (Heat Recovery Steam Generator) using PSO method (Particle Swarm Optimization). In this paper, a parametric analysis followed by a thermodynamic optimization is presented. The chosen objective function is the specific work of the steam cycle that may be, in the case of combined cycle (CC), a good criterion of thermodynamic performance analysis, contrary to the conventional steam turbines in which the thermal efficiency could be also an important criterion. The technologic constraints such as maximal steam cycle temperature, minimal steam fraction at steam turbine outlet, maximal steam pressure, minimal stack temperature, minimal pinch point, and maximal superheater effectiveness are also considered. The parametric analyses permitted to understand the effect of design parameters and the constraints on steam cycle specific work variation. PSO algorithm was used successfully in HRSG optimization, knowing that the achieved results are in accordance with those of the previous studies in which genetic algorithms were used. Moreover, this method is easy to implement comparing with the other methods.

Keywords: combined cycle, HRSG thermodynamic modeling, optimization, PSO, steam cycle specific work

Procedia PDF Downloads 354
14688 Life Cycle Assessment of Todays and Future Electricity Grid Mixes of EU27

Authors: Johannes Gantner, Michael Held, Rafael Horn, Matthias Fischer

Abstract:

At the United Nations Climate Change Conference 2015 a global agreement on the reduction of climate change was achieved stating CO₂ reduction targets for all countries. For instance, the EU targets a reduction of 40 percent in emissions by 2030 compared to 1990. In order to achieve this ambitious goal, the environmental performance of the different European electricity grid mixes is crucial. First, the electricity directly needed for everyone’s daily life (e.g. heating, plug load, mobility) and therefore a reduction of the environmental impacts of the electricity grid mix reduces the overall environmental impacts of a country. Secondly, the manufacturing of every product depends on electricity. Thereby a reduction of the environmental impacts of the electricity mix results in a further decrease of environmental impacts of every product. As a result, the implementation of the two-degree goal highly depends on the decarbonization of the European electricity mixes. Currently the production of electricity in the EU27 is based on fossil fuels and therefore bears a high GWP impact per kWh. Due to the importance of the environmental impacts of the electricity mix, not only today but also in future, within the European research projects, CommONEnergy and Senskin, time-dynamic Life Cycle Assessment models for all EU27 countries were set up. As a methodology, a combination of scenario modeling and life cycle assessment according to ISO14040 and ISO14044 was conducted. Based on EU27 trends regarding energy, transport, and buildings, the different national electricity mixes were investigated taking into account future changes such as amount of electricity generated in the country, change in electricity carriers, COP of the power plants and distribution losses, imports and exports. As results, time-dynamic environmental profiles for the electricity mixes of each country and for Europe overall were set up. Thereby for each European country, the decarbonization strategies of the electricity mix are critically investigated in order to identify decisions, that can lead to negative environmental effects, for instance on the reduction of the global warming of the electricity mix. For example, the withdrawal of the nuclear energy program in Germany and at the same time compensation of the missing energy by non-renewable energy carriers like lignite and natural gas is resulting in an increase in global warming potential of electricity grid mix. Just after two years this increase countervailed by the higher share of renewable energy carriers such as wind power and photovoltaic. Finally, as an outlook a first qualitative picture is provided, illustrating from environmental perspective, which country has the highest potential for low-carbon electricity production and therefore how investments in a connected European electricity grid could decrease the environmental impacts of the electricity mix in Europe.

Keywords: electricity grid mixes, EU27 countries, environmental impacts, future trends, life cycle assessment, scenario analysis

Procedia PDF Downloads 163
14687 Requirement Engineering Within Open Source Software Development: A Case Study

Authors: Kars Beek, Remco Groeneveld, Sjaak Brinkkemper

Abstract:

Although there is much literature available on requirement documentation in traditional software development, few studies have been conducted about this topic in open source software development. While open-source software development is becoming more important, the software development processes are often not as structured as corporate software development processes. Papers show that communities, creating open-source software, often lack structure and documentation. However, most recent studies about this topic are often ten or more years old. Therefore, this research has been conducted to determine if the lack of structure and documentation in requirement engineering is currently still the situation in these communities. Three open-source products have been chosen as subjects for conducting this research. The data for this research was gathered based on interviews, observations, and analyses of feature proposals and issue tracking tools. In this paper, we present a comparison and an analysis of the different methods used for requirements documentation to understand the current practices of requirements documentation in open source software development.

Keywords: case study, open source software, open source software development, requirement elicitation, requirement engineering

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14686 Investigation of Heat Affected Zone of Steel P92 Using the Thermal Cycle Simulator

Authors: Petr Mohyla, Ivo Hlavatý, Jiří Hrubý, Lucie Krejčí

Abstract:

This work is focused on mechanical properties and microstructure of heat affected zone (HAZ) of steel P92. The thermal cycle simulator was used for modeling a fine grained zone of HAZ. Hardness and impact toughness were measured on simulated samples. Microstructural analysis using optical microscopy was performed on selected samples. Achieved results were compared with the values of a real welded joint. The thermal cycle simulator allows transferring the properties of very small HAZ to the sufficiently large sample where the tests of the mechanical properties can be performed. A satisfactory accordance was found when comparing the microstructure and mechanical properties of real welds and simulated samples.

Keywords: heat affected zone, impact test, thermal cycle simulator, time of tempering

Procedia PDF Downloads 277
14685 Variations of Total Electron Content over High Latitude Region during the 24th Solar Cycle

Authors: Arun Kumar Singh, Rupesh M. Das, Shailendra Saini

Abstract:

The effect of solar cycle and seasons on the total electron content has been investigated over high latitude region during 24th solar cycle (2010-2014). The total electron content data has been observed with the help of Global Ionospheric Scintillation and TEC monitoring (GISTM) system installed at Indian permanent scientific 'Maitri station' [70˚46’00”S 11˚43’56” E]. The dependence of TEC over a solar cycle has been examined by the performing linear regression analysis between the vertical total electron content (VTEC) and daily total sunspot numbers (SSN). It has been found that the season and level of geomagnetic activity has a considerable effect on the VTEC. It is observed that the VTEC and SSN follow better agreement during summer seasons as compared to winter and equinox seasons and extraordinary agreement during minimum phase (during the year 2010) of the solar cycle. There is a significant correlation between VTEC and SSN during quiet days of the years as compared to overall days of the years (2010-2014). Further, saturation effect has been observed during maximum phase (during the year 2014) of the 24th solar cycle. It is also found that Ap index and SSN has a linear correlation (R=0.37) and the most of the geomagnetic activity occurs during the declining phase of the solar cycle.

Keywords: high latitude ionosphere, sunspot number, correlation, vertical total electron content

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14684 Fatigue Analysis and Life Estimation of the Helicopter Horizontal Tail under Cyclic Loading by Using Finite Element Method

Authors: Defne Uz

Abstract:

Horizontal Tail of helicopter is exposed to repeated oscillatory loading generated by aerodynamic and inertial loads, and bending moments depending on operating conditions and maneuvers of the helicopter. In order to ensure that maximum stress levels do not exceed certain fatigue limit of the material and to prevent damage, a numerical analysis approach can be utilized through the Finite Element Method. Therefore, in this paper, fatigue analysis of the Horizontal Tail model is studied numerically to predict high-cycle and low-cycle fatigue life related to defined loading. The analysis estimates the stress field at stress concentration regions such as around fastener holes where the maximum principal stresses are considered for each load case. Critical element identification of the main load carrying structural components of the model with rivet holes is performed as a post-process since critical regions with high-stress values are used as an input for fatigue life calculation. Once the maximum stress is obtained at the critical element and the related mean and alternating components, it is compared with the endurance limit by applying Soderberg approach. The constant life straight line provides the limit for several combinations of mean and alternating stresses. The life calculation based on S-N (Stress-Number of Cycles) curve is also applied with fully reversed loading to determine the number of cycles corresponds to the oscillatory stress with zero means. The results determine the appropriateness of the design of the model for its fatigue strength and the number of cycles that the model can withstand for the calculated stress. The effect of correctly determining the critical rivet holes is investigated by analyzing stresses at different structural parts in the model. In the case of low life prediction, alternative design solutions are developed, and flight hours can be estimated for the fatigue safe operation of the model.

Keywords: fatigue analysis, finite element method, helicopter horizontal tail, life prediction, stress concentration

Procedia PDF Downloads 118
14683 Computer Software for Calculating Electron Mobility of Semiconductors Compounds; Case Study for N-Gan

Authors: Emad A. Ahmed

Abstract:

Computer software to calculate electron mobility with respect to different scattering mechanism has been developed. This software is adopted completely Graphical User Interface (GUI) technique and its interface has been designed by Microsoft Visual Basic 6.0. As a case study the electron mobility of n-GaN was performed using this software. The behaviour of the mobility for n-GaN due to elastic scattering processes and its relation to temperature and doping concentration were discussed. The results agree with other available theoretical and experimental data.

Keywords: electron mobility, relaxation time, GaN, scattering, computer software, computation physics

Procedia PDF Downloads 629