Search results for: critical heat flux
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 8664

Search results for: critical heat flux

6894 A Qualitative Study on Metacognitive Patterns among High and Low Performance Problem Based on Learning Groups

Authors: Zuhairah Abdul Hadi, Mohd Nazir bin Md. Zabit, Zuriadah Ismail

Abstract:

Metacognitive has been empirically evidenced to be one important element influencing learning outcomes. Expert learners engage in metacognition by monitoring and controlling their thinking, and listing, considering and selecting the best strategies to achieve desired goals. Studies also found that good critical thinkers engage in more metacognition and people tend to activate more metacognition when solving complex problems. This study extends past studies by performing a qualitative analysis to understand metacognitive patterns among two high and two low performing groups by carefully examining video and audio records taken during Problem-based learning activities. High performing groups are groups with majority members scored well in Watson Glaser II Critical Thinking Appraisal (WGCTA II) and academic achievement tests. Low performing groups are groups with majority members fail to perform in the two tests. Audio records are transcribed and analyzed using schemas adopted from past studies. Metacognitive statements are analyzed using three stages model and patterns of metacognitive are described by contexts, components, and levels for each high and low performing groups.

Keywords: academic achievement, critical thinking, metacognitive, problem-based learning

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6893 Investigation of Changes of Physical Properties of the Poplar Wood in Radial and Longitudinal Axis at Chaaloos Zone

Authors: Afshin Veisi

Abstract:

In this study, the physical properties of wood in poplar wood (Populous sp.) were analyzed in longitudinal and radial directions of the stem. Three Populous Alba tree were cut in chaloos zone and from each tree, 3 discs were selected at 130cm, half of tree and under of crown. The test samples from pith to bark (heartwood to sapwood) were prepared from these discs for measuring the involved properties such as, wet, dry and critical specific gravity, porosity, volume shrinkage and swelling based on the ASTM standard, and data in two radial and longitudinal directions in the trank were statistically analyzed. Such as, variations of wet, dry and critical specific gravity had in radial direction respectively: irregular increase, increase and increase, and in longitudinal direction respectively: irregular decrease, irregular increase and increase. Results of variations to moisture content and porosity show that in radial direction respectively: irregular increasing and decreasing, and in longitudinal direction from down to up respectively: irregular decreasing and stability. Volume shrinkage and swelling variations show in radial direction irregular and in longitudinal axial regular decreasing.

Keywords: poplar wood, physical properties, shrinkage, swelling, critical specific gravity, wet specific gravity, dry specific gravity

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6892 Colonization of Candida Albicans on 3D Printed CAD/CAM Complete Denture Versus Conventional Complete Denture: Randomized Controlled Clinical Study

Authors: Eman Helal, Ahmed M. Esmat

Abstract:

Statement of problem: The development of computer-aided design/computer-aided manufacturing (CAD/CAM) resin dentures has simplified complete denture production. Most of the studies evaluated the mechanical properties of the material, but the hygienic performance of the CAD /CAM denture and their ability to maintain clean surfaces and minimize bacterial accumulation is still lacking. Purpose evaluation of the antibacterial characteristics of the 3D printed CAD/CAM denture and to compare it with the conventional heat polymerized acrylic denture base material. Methodology a total of thirty completely edentulous patients grouped randomly into two groups (Group I: Control group) received conventional heat polymerized acrylic resin complete dentures, (Group II: Test group) received 3D printed (CAD/CAM) dentures (stereolithographic PMMA), Samples of Candida albicans culture swabs were taken after 1 month and 3 months of dentures` insertion. A culture swab was obtained by scrubbing the fitting surface of the upper denture. At each time interval, three swab samples were collected from each patient and were inoculated in three individual culture media. Results: there was a significant difference in the colonization of Candida albicans to the fitting surface of the dentures between both groups (Group I: Conventional denture cases) exhibited more adhesion of Candida Albicans to the fitting surface than did (Group II: CAD/CAM cases) (P<0.05). Conclusion: 3D printed CAD/CAM complete denture showed minimal Candida adherence upon upper denture fitting compared to conventional heat-polymerized acrylic resin, which contributes to decreasing the incidence of denture stomatitis which is considered one of the most common problems among complete denture wearers.

Keywords: CAD/CAM denture, completely edentulous, elderly patients, 3D printing, antimicrobial efficiency, conventional denture, PMMA, Candida Albicans, denture stomatitis

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6891 Kaolinite-Assisted Microencapsulation of Octodecane for Thermal Energy Storage

Authors: Ting Pan, Jiacheng Wang, Pengcheng Lin, Ying Chen, Songping Mo

Abstract:

Phase change materials (PCMs) are widely used in latent heat thermal energy storage because of their good properties such as high energy storage density and constant heat-storage/release temperature. Microencapsulation techniques can prevent PCMs from leaking during the liquid-solid phase transition and enhance thermal properties. This technique has been widely applied in architectural materials, thermo-regulated textiles, aerospace fields, etc. One of the most important processes during the synthesis of microcapsules is to form a stable emulsion of the PCM core and reactant solution for the formation of the shell of the microcapsules. The use of surfactants is usually necessary for the formation of a stable emulsion system because of the difference in hydrophilia/lipophilicity of the PCM and the solvent. Unfortunately, the use of surfactants may cause pollution to the environment. In this study, modified kaolinite was used as an emulsion stabilizer for the microencapsulation of octodecane as PCM. Microcapsules were synthesized by phase inversion emulsification method, and the shell of polymethyl methacrylate (PMMA) was formed through free radical polymerization. The morphologies, crystalloid phase, and crystallization properties of microcapsules were investigated using scanning electron microscopy (SEM), X-ray diffractometer (XRD), and Fourier transforms infrared spectrometer (FTIR). The thermal properties and thermal stability were investigated by a differential scanning calorimeter (DSC) and a thermogravimetric analyzer (TG). The FT-IR, XRD results showed that the octodecane was well encapsulated in the PMMA shell. The SEM results showed that the microcapsules were spheres with an average size of about 50-100nm. The DSC results indicated that the latent heat of the microcapsules was 152.64kJ/kg and 164.23kJ/kg. The TG results confirmed that the microcapsules had good thermal stability due to the PMMA shell. Based on the results, it can be concluded that the modified kaolinite can be used as an emulsifier for the synthesis of PCM microcapsules, which is valid for reducing part of the possible pollution caused by the utilization of surfactants.

Keywords: kaolinite, microencapsulation, PCM, thermal energy storage

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6890 Development of a Thermodynamic Model for Ladle Metallurgy Steel Making Processes Using Factsage and Its Macro Facility

Authors: Prasenjit Singha, Ajay Kumar Shukla

Abstract:

To produce high-quality steel in larger volumes, dynamic control of composition and temperature throughout the process is essential. In this paper, we developed a mass transfer model based on thermodynamics to simulate the ladle metallurgy steel-making process using FactSage and its macro facility. The overall heat and mass transfer processes consist of one equilibrium chamber, two non-equilibrium chambers, and one adiabatic reactor. The flow of material, as well as heat transfer, occurs across four interconnected unit chambers and a reactor. We used the macro programming facility of FactSage™ software to understand the thermochemical model of the secondary steel making process. In our model, we varied the oxygen content during the process and studied their effect on the composition of the final hot metal and slag. The model has been validated with respect to the plant data for the steel composition, which is similar to the ladle metallurgy steel-making process in the industry. The resulting composition profile serves as a guiding tool to optimize the process of ladle metallurgy in steel-making industries.

Keywords: desulphurization, degassing, factsage, reactor

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6889 Automatic MC/DC Test Data Generation from Software Module Description

Authors: Sekou Kangoye, Alexis Todoskoff, Mihaela Barreau

Abstract:

Modified Condition/Decision Coverage (MC/DC) is a structural coverage criterion that is highly recommended or required for safety-critical software coverage. Therefore, many testing standards include this criterion and require it to be satisfied at a particular level of testing (e.g. validation and unit levels). However, an important amount of time is needed to meet those requirements. In this paper we propose to automate MC/DC test data generation. Thus, we present an approach to automatically generate MC/DC test data, from software module description written over a dedicated language. We introduce a new merging approach that provides high MC/DC coverage for the description, with only a little number of test cases.

Keywords: domain-specific language, MC/DC, test data generation, safety-critical software coverage

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6888 The Effect of Shading on Cooling Tower Performance

Authors: Eitidal Albassam

Abstract:

Cooling towers (CTs) in arid zone countries, used for heat rejection in water-cooled (WC) systems, consume a large quantity of water. Universally, water conservation is an issue because of the scarcity of fresh water and natural resources. Therefore, many studies have aimed to conserve fresh water and limit the water wasted. Nonetheless, all these methods are not related to improving the weather conditions around the entering air to CT. In Kuwait and other arid-zone countries, the dry bulb temperature (DBT) during the summer season is significantly greater than the incoming hot water temperature, and the air undergoes sensible cooling. This high DBT leads to extra heat transfer from air to water, demanding high water vaporization to achieve the required cooling of water. Thus, any reduction in ambient air temperature around the CT will minimize water consumption. This paper aims to discuss theoretically the effect of reducing the DBT around the cooling tower when considering the sun-shading barrier. The theoretical simulation model results show that if the DBT reduces by 2.8 °C approximately, the percentage of water evaporation savings in gallon per minute (GPM) starts from 6.48% when DBT reaches 51.67 °C till 9.80% for 37.78 °C. Moreover, the performance of the cooling tower will be improved when considering the appropriate shading barriers, which will not affect the existing wet-bulb temperature.

Keywords: dry-bulb temperature, entering air, water consumption, water vaporization

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6887 Using “Debate” in Enhancing Advanced Chinese Language Classrooms and Learning

Authors: ShuPei Wang, Yina Patterson

Abstract:

This article outlines strategies for improving oral expression to advance proficiency in speaking and listening skills through structured argumentation. The objective is to empower students to effectively use the target language to express opinions and construct compelling arguments. This empowerment is achieved by honing learners' debating and questioning skills, which involves increasing their familiarity with vocabulary and phrases relevant to debates and deepening their understanding of the cultural context surrounding pertinent issues. Through this approach, students can enhance their ability to articulate complex concepts and discern critical points, surpassing superficial comprehension and enabling them to engage in the target language actively and competently.

Keywords: debate, teaching and materials design, spoken expression, listening proficiency, critical thinking

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6886 Modeling of Polyethylene Particle Size Distribution in Fluidized Bed Reactors

Authors: R. Marandi, H. Shahrir, T. Nejad Ghaffar Borhani, M. Kamaruddin

Abstract:

In the present study, a steady state population balance model was developed to predict the polymer particle size distribution (PSD) in ethylene gas phase fluidized bed olefin polymerization reactors. The multilayer polymeric flow model (MPFM) was used to calculate the growth rate of a single polymer particle under intra-heat and mass transfer resistance. The industrial plant data were used to calculate the growth rate of polymer particle and the polymer PSD. Numerical simulations carried out to describe the influence of effective monomer diffusion coefficient, polymerization rate and initial catalyst size on the catalyst particle growth and final polymer PSD. The results present that the intra-heat and mass limitation is important for the ethylene polymerization, the growth rate of particle and the polymer PSD in the fluidized bed reactor. The effect of the agglomeration on the PSD is also considered. The result presents that the polymer particle size distribution becomes broader as the agglomeration exits.

Keywords: population balance, olefin polymerization, fluidized bed reactor, particle size distribution, agglomeration

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6885 Revealing the Urban Heat Island: Investigating its Spatial and Temporal Changes and Relationship with Air Quality

Authors: Aneesh Mathew, Arunab K. S., Atul Kumar Sharma

Abstract:

The uncontrolled rise in population has led to unplanned, swift, and unsustainable urban expansion, causing detrimental environmental impacts on both local and global ecosystems. This research delves into a comprehensive examination of the Urban Heat Island (UHI) phenomenon in Bengaluru and Hyderabad, India. It centers on the spatial and temporal distribution of UHI and its correlation with air pollutants. Conducted across summer and winter seasons from 2001 to 2021 in Bangalore and Hyderabad, this study discovered that UHI intensity varies seasonally, peaking in summer and decreasing in winter. The annual maximum UHI intensities range between 4.65 °C to 6.69 °C in Bengaluru and 5.74 °C to 6.82 °C in Hyderabad. Bengaluru particularly experiences notable fluctuations in average UHI intensity. Introducing the Urban Thermal Field Variance Index (UTFVI), the study indicates a consistent strong UHI effect in both cities, significantly impacting living conditions. Moreover, hotspot analysis demonstrates a rising trend in UHI-affected areas over the years in Bengaluru and Hyderabad. This research underscores the connection between air pollutant concentrations and land surface temperature (LST), highlighting the necessity of comprehending UHI dynamics for urban environmental management and public health. It contributes to a deeper understanding of UHI patterns in swiftly urbanizing areas, providing insights into the intricate relationship between urbanization, climate, and air quality. These findings serve as crucial guidance for policymakers, urban planners, and researchers, facilitating the development of innovative, sustainable strategies to mitigate the adverse impacts of uncontrolled expansion while promoting the well-being of local communities and the global environment.

Keywords: urban heat island effect, land surface temperature, air pollution, urban thermal field variance index

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6884 Stereotyping of Non-Western Students in Western Universities: Applying Critical Discourse Analysis to Undermine Educational Hegemony

Authors: Susan Lubbers

Abstract:

This study applies critical discourse analysis to the language used by educators to frame international students of Asian backgrounds in Anglo-Western universities as quiet, shy, passive and unable to think critically. Emphasis is on the self-promoted ‘internationalised’ Australian tertiary context, where negative stereotypes are commonly voiced not only in the academy but also in the media. Parallels are drawn as well with other Anglo-Western educational contexts. The study critically compares the discourse of these persistent negative stereotypes, with in-class and interview discourses of international students of Asian and Western language, cultural and educational backgrounds enrolled in a Media and Popular Culture unit in an Australian university. The focus of analysis of the student discourse is on their engagement in critical dialogic interactions on the topics of culture and interculturality. The evidence is also drawn from student interviews and focus groups and from observation of whole-class discussion participation rates. The findings of the research project provide evidence that counters the myth of student as problem. They point rather to the widespread lack of intercultural awareness of Western educators and students as being at the heart of the negative perceptions of students of Asian backgrounds. The study suggests the efficacy of an approach to developing intercultural competence that is embedded, or integrated, into tertiary programs. The presentation includes an overview of the main strategies that have been developed by the tertiary educator (author) to support the development of intercultural competence of and among the student cohort. The evidence points to the importance of developing intercultural competence among tertiary educators and students. The failure by educators to ensure that the diverse voices, ideas and perspectives of students from all cultural, educational and language backgrounds are heard in our classrooms means that our universities can hardly be regarded or promoted as genuinely internationalised. They will continue as undemocratic institutions that perpetrate persistent Western educational hegemony.

Keywords: critical discourse analysis, critical thinking, embedding, intercultural competence, interculturality, international student, internationalised education

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6883 Models to Calculate Lattice Spacing, Melting Point and Lattice Thermal Expansion of Ga₂Se₃ Nanoparticles

Authors: Mustafa Saeed Omar

Abstract:

The formula which contains the maximum increase of mean bond length, melting entropy and critical particle radius is used to calculate lattice volume in nanoscale size crystals of Ga₂Se₃. This compound belongs to the binary group of III₂VI₃. The critical radius is calculated from the values of the first surface atomic layer height which is equal to 0.336nm. The size-dependent mean bond length is calculated by using an equation-free from fitting parameters. The size-dependent lattice parameter then is accordingly used to calculate the size-dependent lattice volume. The lattice size in the nanoscale region increases to about 77.6 A³, which is up to four times of its bulk state value 19.97 A³. From the values of the nanosize scale dependence of lattice volume, the nanoscale size dependence of melting temperatures is calculated. The melting temperature decreases with the nanoparticles size reduction, it becomes zero when the radius reaches to its critical value. Bulk melting temperature for Ga₂Se₃, for example, has values of 1293 K. From the size-dependent melting temperature and mean bond length, the size-dependent lattice thermal expansion is calculated. Lattice thermal expansion decreases with the decrease of nanoparticles size and reaches to its minimum value as the radius drops down to about 5nm.

Keywords: Ga₂Se₃, lattice volume, lattice thermal expansion, melting point, nanoparticles

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6882 Development of a Passive Solar Tomato Dryer with Movable Heat Storage System

Authors: Jacob T. Liberty, Wilfred I. Okonkwo

Abstract:

The present study designed and constructed a post-harvest passive solar tomato dryer of dimension 176 x 152 x 54cm for drying tomato. Quality of the dried crop was evaluated and compared with the fresh ones. The solar dryer consist of solar collector (air heater), 110 x 61 x 10 x 10cm, the drying chamber, 102 x54cm, removal heat storage unit, 40 x 35 x 13cm and drying trays, 43 x 42cm. The physicochemical properties of this crop were evaluated before and after drying. Physicochemical properties evaluated includes moisture, protein, fat, fibre, ash, carbohydrate and vitamin C, contents. The fresh, open and solar dried samples were analysed for their proximate composition using the recommended method of AOAC. Also, statistical analysis of the data was conducted using analysis of variance (ANOVA) using completely Randomize Design (CRD) and means were separated by Duncan’s New Multiple Range test (DNMRT). Proximate analysis showed that solar dried tomato had significantly (P < 0.05) higher protein, fibre, ash, carbohydrate and vitamin C except for the fat content that was significantly (P < 0.05) higher for all the open sun dried samples than the solar dried and fresh product. The nutrient which is highly affected by sun drying is vitamin C. Result indicates that moisture loss in solar dried tomato was faster and lower than the open dried samples and as such makes the solar dried products of lesser tendency to mould and bacterial growth. Also, the open sun dried samples had to be carried into the sheltered place each time it rained. The solar dried produce is of high quality. Further processing of the dried crops will involve packaging for commercial purposes. This will also help in making these agricultural product available in a relatively cheap price in off season and also avert micronutrient deficiencies in diet especially among the low-income groups in Nigeria.

Keywords: tomato, passive solar dryer, physicochemical properties, removal heat storage

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6881 Bifurcations of the Rotations in the Thermocapillary Flows

Authors: V. Batishchev, V. Getman

Abstract:

We study the self-similar fluid flows in the Marangoni layers with the axial symmetry. Such flows are induced by the radial gradients of the temperatures whose distributions along the free boundary obey some power law. The self-similar solutions describe thermo-capillar flows both in the thin layers and in the case of infinite thickness. We consider both positive and negative temperature gradients. In the former case the cooling of free boundary nearby the axis of symmetry gives rise to the rotation of fluid. The rotating flow concentrates itself inside the Marangoni layer while outside of it the fluid does not revolve. In the latter case we observe no rotating flows at all. In the layers of infinite thickness the separation of the rotating flow creates two zones where the flows are directed oppositely. Both the longitudinal velocity and the temperature have exactly one critical point inside the boundary layer. It is worth to note that the profiles are monotonic in the case of non-swirling flows. We describe the flow outside the boundary layer with the use of self-similar solution of the Euler equations. This flow is slow and non-swirling. The introducing of an outer flow gives rise to the branching of swirling flows from the non-swirling ones. There is such the critical velocity of the outer flow that a non-swirling flow exists for supercritical velocities and cannot be extended to the sub-critical velocities. For the positive temperature gradients there are two non-swirling flows. For the negative temperature gradients the non-swirling flow is unique. We determine the critical velocity of the outer flow for which the branching of the swirling flows happens. In the case of a thin layer confined within free boundaries we show that the cooling of the free boundaries near the axis of symmetry leads to the separating of the layer and creates two sub-layers with opposite rotations inside. This makes sharp contrast with the case of infinite thickness. We show that such rotation arises provided the thickness of the layer exceed some critical value. In the case of a thin layer confined within free and rigid boundaries we construct the branching equation and the asymptotic approximation for the secondary swirling flows near the bifurcation point. It turns out that the bifurcation gives rise to one pair of the secondary swirling flows with different directions of swirl.

Keywords: free surface, rotation, fluid flow, bifurcation, boundary layer, Marangoni layer

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6880 At the Crossroads of Education and Human Rights for Girls and Women in Nigeria: The Language Perspective

Authors: Crescentia Ugwuona

Abstract:

Appropriate language use has been central and critical in advancing education and human rights for women and girls in many countries the world over. Unfortunately, these lofty aims have often been violated by rural Igbo-Nigerians as they use stereotyping and dehumansing language in their cultural songs against women and girls. The psychological impact of the songs has a significant negative impact on education, human rights, quality of life, and opportunities for many rural Igbo-women and girls in Nigeria. This study, therefore, examines the forms, shades, and manifestations of derogatory and stereotypical language against women and girls the Igbo cultural songs; and how they impede education and human rights for females in Nigeria. Through Critical discourse analysis (CDA) of data collected via recording, the study identifies manifestations of women and girls’ stereotypes such as subjugations, male dominance, inequality in gender roles, suppression, and oppression, and derogatory use of the language against women and girls in the Igbo cultural songs. This study has a great promise of alerting the issues of derogatory and stereotypical language in songs, and contributes to an education aimed at gender equality, emancipator practice of appropriate language use in songs, equal education and human rights for both male and female, respect and solidarity in Nigeria and beyond.

Keywords: gender stereotypes, cultural songs, women and girls, language use in Nigeria, critical discourse analysis, CDA, education

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6879 Advanced Nuclear Measurements and Systems for Facilitating the Implementation of Safeguards and Safeguards-By-Design in SMR, AMR and Microreactor

Authors: Massimo Morichi

Abstract:

Over the last five years, starting in 2019, several nuclear measurement systems have been conceived and realized for specific nuclear safeguards applications, as well as for nuclear security, implementing some innovative technologies and methods for attended and unattended nuclear measurements. Some of those technologies imply the integration of combined gamma and neutron detection systems both for counting and spectroscopic applications that allow the SNM (Special Nuclear Material) verification and quantification through specific simultaneous measurements (gamma and neutron) from standard to high count rate due to high flux irradiation. IAEA has implemented some of these technologies in key international safeguards inspections worldwide, like a Fast Neutron Collar Monitor for fresh fuel verification of U235 mass (used during inspections for material declaration verification) or for unattended measuring systems with a distinct shift register installed in an anti-tampering sealed housing in unattended mode (remote inspection and continuous monitoring) together with an Unattended Multichannel Analyzer for spectroscopy analysis of SNM like canisters. Such developments, realized with integrated mid-resolution scintillators (FWHM: <3,5%) together with organic scintillators such as Stilbene detectors or Liquid sealed scintillators like EJ-309 with great pulse shape discrimination managed by a fast DAQ and with a high level of system integration, are offering in the near term the possibility to enhance further their implementation, reducing the form factor in order to facilitate their implementation in many critical parts of the Nuclear Fuel Operations as well as of the Next generation of Nuclear Reactors. This will facilitate embedding these advanced technical solutions in the next generation of nuclear installations, assuring the implementation of the Safeguards by Design requested by IAEA for all future/novel nuclear installations. This work presents the most recent designs/systems and provides some clear examples of ongoing applications on the Fuel Cycle-Fuel Fabrication as well as for the SMR/AMR and microreactors. Detailed technology testing and validation in different configuration if provided together with some case-studies and operational implications.

Keywords: nuclear safeguard, gamma and neutron detection systems, spectroscopy analysis, nuclear fuel cycle, nuclear power reactors, decommissioning dismantling, nuclear security

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6878 Impact of Combined Heat and Power (CHP) Generation Technology on Distribution Network Development

Authors: Sreto Boljevic

Abstract:

In the absence of considerable investment in electricity generation, transmission and distribution network (DN) capacity, the demand for electrical energy will quickly strain the capacity of the existing electrical power network. With anticipated growth and proliferation of Electric vehicles (EVs) and Heat pump (HPs) identified the likelihood that the additional load from EV changing and the HPs operation will require capital investment in the DN. While an area-wide implementation of EVs and HPs will contribute to the decarbonization of the energy system, they represent new challenges for the existing low-voltage (LV) network. Distributed energy resources (DER), operating both as part of the DN and in the off-network mode, have been offered as a means to meet growing electricity demand while maintaining and ever-improving DN reliability, resiliency and power quality. DN planning has traditionally been done by forecasting future growth in demand and estimating peak load that the network should meet. However, new problems are arising. These problems are associated with a high degree of proliferation of EVs and HPs as load imposes on DN. In addition to that, the promotion of electricity generation from renewable energy sources (RES). High distributed generation (DG) penetration and a large increase in load proliferation at low-voltage DNs may have numerous impacts on DNs that create issues that include energy losses, voltage control, fault levels, reliability, resiliency and power quality. To mitigate negative impacts and at a same time enhance positive impacts regarding the new operational state of DN, CHP system integration can be seen as best action to postpone/reduce capital investment needed to facilitate promotion and maximize benefits of EVs, HPs and RES integration in low-voltage DN. The aim of this paper is to generate an algorithm by using an analytical approach. Algorithm implementation will provide a way for optimal placement of the CHP system in the DN in order to maximize the integration of RES and increase in proliferation of EVs and HPs.

Keywords: combined heat & power (CHP), distribution networks, EVs, HPs, RES

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6877 The Intersection of Autistic and Trans* Identity: Qualitative Engaged Study in Eastern Europian Activist Groups

Authors: Hana Drštičková

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The paper describes the findings of a qualitative, engaged research focused on the intersection between transgender and autistic identity in a politically engaged setting of activist (trans, queer, crip, disability justice or any combination thereof) groups. It explores the relationship that autistic and trans people have towards activism and how do they feel their identity(ies) impact the kind of political action they take. Geographically, the research terrain is located mainly in Czechia; however, there are important overlaps with other Eastern European countries. The basis of the research’s approach is built on the interconnected principles of the feminist theory of intersectionality, queer/trans studies, disability studies and the concept of the Neurodiversity Paradigm. This paper argues that the social phenomenon of autism and transness is formed differently in Czechia/Eastern Europe and, therefore, deserves additional attention. Nevertheless, it points out that, even though the socio-political context is different, the fact that these identities have a radical political potential to disrupt normative structures in society remains the same. The measure of oppression these structures generate, and the near absence of any public discourse beyond the pathological paradigm in the chosen terrain contributes to the emergence of mainly queer and trans-activist, and to a lesser extent crip, disability justice or mad activist groups, that attract trans and autistic membership. The subsections of the research focus on the topics of the mutual influence of both identities in flux within individual participants, the perceived (dis)connection of networks of oppression or, conversely, support and identification with the community or communities, and the question of how the trans* and autistic members feel their presence affects the activity, internal dynamics, thematic scope and general values of the activist groups they participate in. The research methodology includes participant observation and active participation in groups where the researcher acts as a partial insider, semi-structured in-depth interviews and a critical participatory methodology. Also included is the reflection of not only the combination of researcher and insider roles but also the combination of research and activist intent.

Keywords: activism, autism, queer, neurodiversity, neuroqueer, transgender

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6876 Modelling of Exothermic Reactions during Carbon Fibre Manufacturing and Coupling to Surrounding Airflow

Authors: Musa Akdere, Gunnar Seide, Thomas Gries

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Carbon fibres are fibrous materials with a carbon atom amount of more than 90%. They combine excellent mechanicals properties with a very low density. Thus carbon fibre reinforced plastics (CFRP) are very often used in lightweight design and construction. The precursor material is usually polyacrylonitrile (PAN) based and wet-spun. During the production of carbon fibre, the precursor has to be stabilized thermally to withstand the high temperatures of up to 1500 °C which occur during carbonization. Even though carbon fibre has been used since the late 1970s in aerospace application, there is still no general method available to find the optimal production parameters and the trial-and-error approach is most often the only resolution. To have a much better insight into the process the chemical reactions during stabilization have to be analyzed particularly. Therefore, a model of the chemical reactions (cyclization, dehydration, and oxidation) based on the research of Dunham and Edie has been developed. With the presented model, it is possible to perform a complete simulation of the fibre undergoing all zones of stabilization. The fiber bundle is modeled as several circular fibers with a layer of air in-between. Two thermal mechanisms are considered to be the most important: the exothermic reactions inside the fiber and the convective heat transfer between the fiber and the air. The exothermic reactions inside the fibers are modeled as a heat source. Differential scanning calorimetry measurements have been performed to estimate the amount of heat of the reactions. To shorten the required time of a simulation, the number of fibers is decreased by similitude theory. Experiments were conducted to validate the simulation results of the fibre temperature during stabilization. The experiments for the validation were conducted on a pilot scale stabilization oven. To measure the fibre bundle temperature, a new measuring method is developed. The comparison of the results shows that the developed simulation model gives good approximations for the temperature profile of the fibre bundle during the stabilization process.

Keywords: carbon fibre, coupled simulation, exothermic reactions, fibre-air-interface

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6875 Environmental Education and Climate Change Resilience Development in Schools of Pakistan

Authors: Mehak Masood

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Education is critical for promoting sustainable development and improving the capacity of people to address environment and development issues. It is also critical for achieving environmental and ethical awareness, values and attitudes, skills and behaviour consistent with sustainable development and for effective public participation in decision-making. In this regard, The British Council Pakistan have conducted a need assessment study conducted during the training sessions with three different groups of educationists belonging to both government and public sectors on the topic of Climate Change and Environmental Education (CCEE). This study aims to review perceptions about climate change and environmental education and analyze its need and importance according to educationists of Pakistan.

Keywords: environmental education, climate change, resilience development, awareness

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6874 Assessment of Commercial Antimicrobials Incorporated into Gelatin Coatings and Applied to Conventional Heat-Shrinking Material for the Prevention of Blown Pack Spoilage in Vacuum Packaged Beef Cuts

Authors: Andrey A. Tyuftin, Rachael Reid, Paula Bourke, Patrick J. Cullen, Seamus Fanning, Paul Whyte, Declan Bolton , Joe P. Kerry

Abstract:

One of the primary spoilage issues associated with vacuum-packed beef products is blown pack spoilage (BPS) caused by the psychrophilic spore-forming strain of Clostridium spp. Spores derived from this organism can be activated after heat-shrinking (eg. 90°C for 3 seconds). To date, research into the control of Clostridium spp in beef packaging is limited. Active packaging in the form of antimicrobially-active coatings may be one approach to its control. Antimicrobial compounds may be incorporated into packaging films or coated onto the internal surfaces of packaging films using a carrier matrix. Three naturally-sourced, commercially-available antimicrobials, namely; Auranta FV (AFV) (bitter oranges extract) from Envirotech Innovative Products Ltd, Ireland; Inbac-MDA (IMDA) from Chemital LLC, Spain, mixture of different organic acids and sodium octanoate (SO) from Sigma-Aldrich, UK, were added into gelatin solutions at 2 concentrations: 2.5 and 3.5 times their minimum inhibition concentration (MIC) against Clostridium estertheticum (DSMZ 8809). These gelatin solutions were coated onto the internal polyethylene layer of cold plasma treated, heat-shrinkable laminates conventionally used for meat packaging applications. Atmospheric plasma was used in order to enhance adhesion between packaging films and gelatin coatings. Pouches were formed from these coated packaging materials, and beef cuts which had been inoculated with C. estertheticum were vacuum packaged. Inoculated beef was vacuum packaged without employing active films and this treatment served as the control. All pouches were heat-sealed and then heat-shrunk at 90°C for 3 seconds and incubated at 2°C for 100 days. During this storage period, packs were monitored for the indicators of blown pack spoilage as follows; gas bubbles in drip, loss of vacuum (onset of BPS), blown, the presence of sufficient gas inside the packs to produce pack distension and tightly stretched, “overblown” packs/ packs leaking. Following storage and assessment of indicator date, it was concluded that AFV- and SO-containing packaging inhibited the growth of C. estertheticum, significantly delaying the blown pack spoilage of beef primals. IMDA did not inhibit the growth of C. estertheticum. This may be attributed to differences in release rates and possible reactions with gelatin. Overall, active films were successfully produced following plasma surface treatment, and experimental data demonstrated clearly that the use of antimicrobially-active films could significantly prolong the storage stability of beef primals through the effective control of BPS.

Keywords: active packaging, blown pack spoilage, Clostridium, antimicrobials, edible coatings, food packaging, gelatin films, meat science

Procedia PDF Downloads 266
6873 Bio-Hub Ecosystems: Expansion of Traditional Life Cycle Analysis Metrics to Include Zero-Waste Circularity Measures

Authors: Kimberly Samaha

Abstract:

In order to attract new types of investors into the emerging Bio-Economy, a new set of metrics and measurement system is needed to better quantify the environmental, social and economic impacts of circular zero-waste design. The Bio-Hub Ecosystem model was developed to address a critical area of concern within the global energy market regarding the use of biomass as a feedstock for power plants. Lack of an economically-viable business model for bioenergy facilities has resulted in the continuation of idled and decommissioned plants. In particular, the forestry-based plants which have been an invaluable outlet for woody biomass surplus, forest health improvement, timber production enhancement, and especially reduction of wildfire risk. This study looked at repurposing existing biomass-energy plants into Circular Zero-Waste Bio-Hub Ecosystems. A Bio-Hub model that first targets a ‘whole-tree’ approach and then looks at the circular economics of co-hosting diverse industries (wood processing, aquaculture, agriculture) in the vicinity of the Biomass Power Plants facilities. It proposes not only models for integration of forestry, aquaculture, and agriculture in cradle-to-cradle linkages of what have typically been linear systems, but the proposal also allows for the early measurement of the circularity and impact of resource use and investment risk mitigation, for these systems. Typically, life cycle analyses measure environmental impacts of different industrial production stages and are not integrated with indicators of material use circularity. This concept paper proposes the further development of a new set of metrics that would illustrate not only the typical life-cycle analysis (LCA), which shows the reduction in greenhouse gas (GHG) emissions, but also the zero-waste circularity measures of mass balance of the full value chain of the raw material and energy content/caloric value. These new measures quantify key impacts in making hyper-efficient use of natural resources and eliminating waste to landfills. The project utilized traditional LCA using the GREET model where the standalone biomass energy plant case was contrasted with the integration of a jet-fuel biorefinery. The methodology was then expanded to include combinations of co-hosts that optimize the life cycle of woody biomass from tree to energy, CO₂, heat and wood ash both from an energy/caloric value and for mass balance to include reuse of waste streams which are typically landfilled. The major findings of both a formal LCA study resulted in the masterplan for the first Bio-Hub to be built in West Enfield, Maine. Bioenergy facilities are currently at a critical juncture where they have an opportunity to be repurposed into efficient, profitable and socially responsible investments, or be idled and scrapped. If proven as a model, the expedited roll-out of these innovative scenarios can set a new standard for circular zero-waste projects that advance the critical transition from the current ‘take-make-dispose’ paradigm inherent in the energy, forestry and food industries to a more sustainable bio-economy paradigm where waste streams become valuable inputs, supporting local and rural communities in simple, sustainable ways.

Keywords: bio-economy, biomass energy, financing, metrics

Procedia PDF Downloads 158
6872 Investigation of Distortion and Impact Strength of 304L Butt Joint Using Different Weld Groove

Authors: A. Sharma, S. S. Sandhu, A. Shahi, A. Kumar

Abstract:

The aim of present investigation was to carry out Finite element modeling of distortion in the case of butt weld. 12mm thick AISI 304L plates were butt welded using three different combinations of groove design namely Double U, Double V and Composite. A full simulation of shielded metal arc welding (SMAW) of nonlinear heat transfer is carried out. Aspects like, temperature-dependent thermal properties of AISI stainless steel above liquid phase, the effect of thermal boundary conditions, were included in the model. Since welding heat dissipation characteristics changed due to variable groove design significant changes in the microhardness tensile strength and impact toughness of the joints were observed. The cumulative distortion was found to be least in double V joint followed by the Composite and Double U-joints. All the joints have joint efficiency more than 100%. CVN value of the Double V-groove weld metal was highest. The experimental results and the FEM results were compared and reveal a very good correlation for distortion and weld groove design for a multipass joint with a standard analogy of 83%.

Keywords: AISI 304 L, Butt joint, distortion, FEM, groove design, SMAW

Procedia PDF Downloads 408
6871 An Attempt to Get Communication Design Students to Reflect: A Content Analysis of Students’ Learning Journals

Authors: C. K. Peter Chuah

Abstract:

Essentially, the intention of reflective journal is meant for students to develop higher-order thinking skills and to provide a 'space' to make their learning experience and thinking, making and feeling visible, i.e., it provides students an opportunity to evaluate their learning critically by focusing on the rationale behind their thinking, making and feeling. In addition, reflective journal also gets the students to focus on how could things be done differently—the possibility, alternative point of views, and opportunities for change. It is hoped that by getting communication design students to reflect at various intervals, they could move away from mere working on the design project and pay more attention to what they thought they have learned in relation to the development of their design ability. Unfortunately, a closer examination—through content analysis—of the learning journals submitted by a group of design students revealed that most of the reflections were descriptive and tended to be a summary of what occurred in the learning experience. While many students were able to describe what they did, very few were able to explain how they were able to do something critically. It can be concluded that to get design students to reflect is a fairly easy task, but to get them to reflect critically could be very challenging. To ensure that design students could benefit from the use of reflective journal as a tool to develop their critical thinking skills, a more systematic and structured approach to the introduction of critical thinking and reflective journal should be built into the design curriculum to provide as much practice and sufficient feedback as other studio subjects.

Keywords: communication design education, critical thinking, reflection, reflective journal

Procedia PDF Downloads 286
6870 An Empirical Study of Critical Success Factors for the Adoption of M-Government Services in Tanzania

Authors: Fredrick Ishengoma, Leonard Mselle, Hector Mongi

Abstract:

The growing number of mobile phone subscribers in Tanzania offers the government a new channel for the delivery of information and government services to citizens, thus mobile Government (m-Government). In Tanzania, m-Government services usage is in the early stages, and factors that influence its adoption are yet to be known. This study seeks to identify and understand the critical success factors (CSFs) that influence citizens’ behavioural intention (BI) to adopt m-Government services in Tanzania. The study employed the mobile services acceptance model (MSAM) and extends it with external factors relevant in the Tanzanian context. A survey questionnaire was used to collect primary data from users of m-Government services in Dar es salaam and Dodoma cities, and 253 responses were received. Data were analyzed by IBM-SPSS AMOS 23.0 software using structural equation modeling (SEM). The findings of the study indicate that perceived usefulness, trust, perceived mobility, power distance, quality of service, awareness, perceived cost, personal initiatives, and characteristics significantly influence the BI to adopt m-Government services. However, perceived ease of use was found statistically insignificant to predict BI. Furthermore, the interplay between CSFs, discussion on theoretical and practical implications that follow from the results are presented.

Keywords: adoption, critical success factors, structural equation modeling, m-Government, MSAM, Tanzania

Procedia PDF Downloads 151
6869 Improved Qualitative Modeling of the Magnetization Curve B(H) of the Ferromagnetic Materials for a Transformer Used in the Power Supply for Magnetron

Authors: M. Bassoui, M. Ferfra, M. Chrayagne

Abstract:

This paper presents a qualitative modeling for the nonlinear B-H curve of the saturable magnetic materials for a transformer with shunts used in the power supply for the magnetron. This power supply is composed of a single phase leakage flux transformer supplying a cell composed of a capacitor and a diode, which double the voltage and stabilize the current, and a single magnetron at the output of the cell. A procedure consisting of a fuzzy clustering method and a rule processing algorithm is then employed for processing the constructed fuzzy modeling rules to extract the qualitative properties of the curve.

Keywords: B(H) curve, fuzzy clustering, magnetron, power supply

Procedia PDF Downloads 241
6868 Modeling Residual Modulus of Elasticity of Self-Compacted Concrete Using Artificial Neural Networks

Authors: Ahmed M. Ashteyat

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Artificial Neural Network (ANN) models have been widely used in material modeling, inter-correlations, as well as behavior and trend predictions when the nonlinear relationship between system parameters cannot be quantified explicitly and mathematically. In this paper, ANN was used to predict the residual modulus of elasticity (RME) of self compacted concrete (SCC) damaged by heat. The ANN model was built, trained, tested and validated using a total of 112 experimental data sets, gathered from available literature. The data used in model development included temperature, relative humidity conditions, mix proportions, filler types, and fiber type. The result of ANN training, testing, and validation indicated that the RME of SCC, exposed to different temperature and relative humidity levels, could be predicted accurately with ANN techniques. The reliability between the predicated outputs and the actual experimental data was 99%. This show that ANN has strong potential as a feasible tool for predicting residual elastic modulus of SCC damaged by heat within the range of input parameter. The ANN model could be used to estimate the RME of SCC, as a rapid inexpensive substitute for the much more complicated and time consuming direct measurement of the RME of SCC.

Keywords: residual modulus of elasticity, artificial neural networks, self compacted-concrete, material modeling

Procedia PDF Downloads 536
6867 Getting to Know the Types of Concrete and its Production Methods

Authors: Mokhtar Nikgoo

Abstract:

Definition of Concrete and Concreting: Concrete (in French: Béton) in a broad sense is any substance or combination that consists of a sticky substance with the property of cementation. In general, concrete refers to concrete made by Portland cement, which is produced by mixing fine and coarse aggregates, Portland cement and water. After enough time, this mixture turns into a stone-like substance. During the hardening or processing of the concrete, cement is chemically combined with water to form strong crystals that bind the aggregates together, a process called hydration. During this process, significant heat is released called hydration heat. Additionally, concrete shrinks slightly, especially as excess water evaporates, a phenomenon known as drying shrinkage. The process of hardening and the gradual increase in concrete strength that occurs with it does not end suddenly unless it is artificially interrupted. Instead, it decreases more over long periods of time, although, in practical applications, concrete is usually set after 28 days and is considered at full design strength. Concrete may be made from different types of cement as well as pozzolans, furnace slag, additives, additives, polymers, fibers, etc. It may also be used in the way it is made, heating, water vapor, autoclave, vacuum, hydraulic pressures and various condensers.

Keywords: concrete, RCC, batching, cement, Pozzolan, mixing plan

Procedia PDF Downloads 100
6866 Exploring the Influence of Normative, Financial and Environmental Decision Frames in Nudging 'Green' Behaviour, and Increasing Uptake of Energy-Efficient Technologies

Authors: Rebecca Hafner, Daniel Read, David Elmes

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The persuasive potential of normative and feedback (financial vs. environmental) information in ‘nudging’ people towards making environmentally sound decisions was explored in a hypothetical choice experiment. The research was specifically focused on determining how subtle variations in the decision frame could be used to increase the selection of energy efficient vs. standard technologies, using the context of home heating choice. Participants were given a choice of a standard heating system (a gas boiler) and a relatively more-energy efficient option (a heat pump). The experiment had a 2 (normative vs. no normative information) by 3 feedback type (financial, environmental, none) design. The last group constituted the control. Half of the participants were given normative information about what the majority of others in their neighbourhood had opted to do when faced with the same choice set, prior to making their decision. The other half received no such information. Varying feedback frames were incorporated by providing participants with information on either financial or environmental savings that could be achieved by choosing the heat pump. No such information was provided in the control group. A significant interaction was found between normative information and feedback frame type. Specifically, the impact of feedback frames was found to be reduced when normative information was provided; illustrating the overriding influence of normative information on option preference. Participants were significantly more likely to select the heat pump if they were vs. were not given normative information. Yet when no normative information was provided, the persuasive influence of the financial frame was increased – highlighting this as an effective means of encouraging uptake of new technologies in this instance. Conversely, the environmental frame was not found to differ significantly from the control. Marginal carryover effects were also found for stated future real-life decision-making behaviour, with participants who were versus were not given normative information being marginally more likely to state they would consider installing a heat pump when they next need to replace their heating system in real life. We conclude that normative and financial feedback framing techniques are highly effective in increasing uptake of new, energy efficient heating technologies involving significant upfront financial outlay. The implications for researchers looking to promote ‘green’ choice in the context of new technology adoption are discussed.

Keywords: energy-efficient technology adoption, environmental decision making, financial vs. environmental feedback framing techniques, social norms

Procedia PDF Downloads 309
6865 Effect of Removing Hub Domain on Human CaMKII Isoforms Sensitivity to Calcium/Calmodulin

Authors: Ravid Inbar

Abstract:

CaMKII (calcium-calmodulin dependent protein kinase II) makes up 2% of the protein in our brain and has a critical role in memory formation and long-term potentiation of neurons. Despite this, research has yet to uncover the role of one of the domains on the activation of this kinase. The following proposes to express the protein without the hub domain in E. coli, leaving only the kinase and regulatory segment of the protein. Next, a series of kinase assays will be conducted to elucidate the role the hub domain plays on CaMKII sensitivity to calcium/calmodulin activation. The hub domain may be important for activation; however, it may also be a variety of domains working together to influence protein activation and not the hub alone. Characterization of a protein is critical to the future understanding of the protein's function, as well as for producing pharmacological targets in cases of patients with diseases.

Keywords: CaMKII, hub domain, kinase assays, kinase + reg seg

Procedia PDF Downloads 92