Search results for: small series assembly

Authors: Renata Gerhardt, Detlev Belder

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Raman spectroscopy has attracted much attention as a structurally descriptive and label-free detection method. It is particularly suited for chemical analysis given as it is non-destructive and molecules can be identified via the fingerprint region of the spectra. In this work possibilities are investigated how to integrate Raman spectroscopy as a detection method for chip-based chromatography, making use of a droplet interface. A demanding task in lab-on-a-chip applications is the specific and sensitive detection of low concentrated analytes in small volumes. Fluorescence detection is frequently utilized but restricted to fluorescent molecules. Furthermore, no structural information is provided. Another often applied technique is mass spectrometry which enables the identification of molecules based on their mass to charge ratio. Additionally, the obtained fragmentation pattern gives insight into the chemical structure. However, it is only applicable as an end-of-the-line detection because analytes are destroyed during measurements. In contrast to mass spectrometry, Raman spectroscopy can be applied on-chip and substances can be processed further downstream after detection. A major drawback of Raman spectroscopy is the inherent weakness of the Raman signal, which is due to the small cross-sections associated with the scattering process. Enhancement techniques, such as surface enhanced Raman spectroscopy (SERS), are employed to overcome the poor sensitivity even allowing detection on a single molecule level. In SERS measurements, Raman signal intensity is improved by several orders of magnitude if the analyte is in close proximity to nanostructured metal surfaces or nanoparticles. The main gain of lab-on-a-chip technology is the building block-like ability to seamlessly integrate different functionalities, such as synthesis, separation, derivatization and detection on a single device. We intend to utilize this powerful toolbox to realize Raman detection in chip-based chromatography. By interfacing on-chip separations with a droplet generator, the separated analytes are encapsulated into numerous discrete containers. These droplets can then be injected with a silver nanoparticle solution and investigated via Raman spectroscopy. Droplet microfluidics is a sub-discipline of microfluidics which instead of a continuous flow operates with the segmented flow. Segmented flow is created by merging two immiscible phases (usually an aqueous phase and oil) thus forming small discrete volumes of one phase in the carrier phase. The study surveys different chip designs to realize coupling of chip-based chromatography with droplet microfluidics. With regards to maintaining a sufficient flow rate for chromatographic separation and ensuring stable eluent flow over the column different flow rates of eluent and oil phase are tested. Furthermore, the detection of analytes in droplets with surface enhanced Raman spectroscopy is examined. The compartmentalization of separated compounds preserves the analytical resolution since the continuous phase restricts dispersion between the droplets. The droplets are ideal vessels for the insertion of silver colloids thus making use of the surface enhancement effect and improving the sensitivity of the detection. The long-term goal of this work is the first realization of coupling chip based chromatography with droplets microfluidics to employ surface enhanced Raman spectroscopy as means of detection.

Keywords: chip-based separation, chip LC, droplets, Raman spectroscopy, SERS

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Authors: Yohanna Panshak

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The impact of macroeconomic instability on economic growth and prosperity has been at forefront in many discourses among researchers and policy makers and has generated a lot of controversies over the years. This has generated series of research efforts towards understanding the remote causes of this phenomenon; its nature, determinants and how it can be targeted and mitigated. While others have opined that the root cause of macroeconomic flux in Nigeria is attributed to Oil-Price volatility, others viewed the issue as resulting from some constellation of structural constraints both within and outside the shores of the country. Research works of scholars such as [Akpan (2009), Aliyu (2009), Olomola (2006), etc] argue that oil volatility can determine economic growth or has the potential of doing so. On the contrary, [Darby (1982), Cerralo (2005) etc] share the opinion that it can slow down growth. The earlier argument rest on the understanding that for a net balance of oil exporting economies, price upbeat directly increases real national income through higher export earnings, whereas, the latter allude to the case of net-oil importing countries (which experience price rises, increased input costs, reduced non-oil demand, low investment, fall in tax revenues and ultimately an increase in budget deficit which will further reduce welfare level). Therefore, assessing the precise impact of oil price volatility on virtually any economy is a function of whether it is an oil-exporting or importing nation. Research on oil price volatility and its outcome on the growth of the Nigerian economy are evolving and in a march towards resolving Nigeria’s macroeconomic instability as long as oil revenue still remain the mainstay and driver of socio-economic engineering. Recently, a major importer of Nigeria’s oil- United States made a historic breakthrough in more efficient source of energy for her economy with the capacity of serving significant part of the world. This undoubtedly suggests a threat to the exchange earnings of the country. The need to understand fluctuation in its major export commodity is critical. This paper leans on the Renaissance growth theory with greater focus on theoretical work of Lee (1998); a leading proponent of this school who makes a clear cut of difference between oil price changes and oil price volatility. Based on the above background, the research seeks to empirically examine the impact oil-price volatility on government expenditure using quarterly time series data spanning 1986:1 to 2014:4. Vector Auto Regression (VAR) econometric approach shall be used. The structural properties of the model shall be tested using Augmented Dickey-Fuller and Phillips-Perron. Relevant diagnostics tests of heteroscedasticity, serial correlation and normality shall also be carried out. Policy recommendation shall be offered on the empirical findings and believes it assist policy makers not only in Nigeria but the world-over.

Keywords: oil-price, volatility, prosperity, budget, expenditure

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Authors: Ahmed I. Raheem

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In this thesis, stratified and stratified wavy flow regimes have been investigated numerically for the oil (1.57 mPa s viscosity and 780 kg/m3 density) and water twophase flow in small and large horizontal steel pipes with a diameter between 0.0254 to 0.508 m by ANSYS Fluent software. Volume of fluid (VOF) with two phases flows using two equations family models (Realizable k-

Keywords: CFD, two-phase flow, pressure gradient, volume of fluid, large diameter, horizontal pipe, oil-water stratified and stratified wavy flow

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Authors: El Metmati Abdelhaq

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Shear strength of sandy soils has been considered as the important parameter to study the stability of different civil engineering structures when subjected to monotonic, cyclic and earthquake loading conditions. The objective of this laboratory investigation is to study the influence of the fraction of low plastic fines and gradation on the mechanical behavior of sand-silt mixtures reconstituted in the laboratory. For this purpose, a series of Casagrande shear box tests were carried out on different reconstituted samples of sand-silt mixtures with various gradations at two initial relative densities (Dr = 20 and 91 %) with different fines content ranging from 0 to 40 %. The soil samples were tested under different normal stresses (100, 200 and 300 kPa). The evaluation of the data indicates that the fines content and the gradation have significant influence on the friction angle and the cohesion.

Keywords: mechanical behavior, silty sand, friction angle, cohesion, fines content

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Authors: Takashi Yamaguchi, Ichio Asanuma, Jong G. Park, Kenneth J. Mackin, John Mittleman

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In this paper, vessel detection using the artificial neural network is proposed in order to automatically construct the vessel detection model from the satellite imagery of day/night band (DNB) in visible infrared in the products of Imaging Radiometer Suite (VIIRS) on Suomi National Polar-orbiting Partnership (Suomi-NPP).The goal of our research is the establishment of vessel detection method using the satellite imagery of DNB in order to monitor the change of vessel activity over the wide region. The temporal vessel monitoring is very important to detect the events and understand the circumstances within the maritime environment. For the vessel locating and detection techniques, Automatic Identification System (AIS) and remote sensing using Synthetic aperture radar (SAR) imagery have been researched. However, each data has some lack of information due to uncertain operation or limitation of continuous observation. Therefore, the fusion of effective data and methods is important to monitor the maritime environment for the future. DNB is one of the effective data to detect the small vessels such as fishery ships that is difficult to observe in AIS. DNB is the satellite sensor data of VIIRS on Suomi-NPP. In contrast to SAR images, DNB images are moderate resolution and gave influence to the cloud but can observe the same regions in each day. DNB sensor can observe the lights produced from various artifact such as vehicles and buildings in the night and can detect the small vessels from the fishing light on the open water. However, the modeling of vessel detection using DNB is very difficult since complex atmosphere and lunar condition should be considered due to the strong influence of lunar reflection from cloud on DNB. Therefore, artificial neural network was applied to learn the vessel detection model. For the feature of vessel detection, Brightness Temperature at the 3.7 μm (BT3.7) was additionally used because BT3.7 can be used for the parameter of atmospheric conditions.

Keywords: artificial neural network, day/night band, remote sensing, Suomi National Polar-orbiting Partnership, vessel detection, Visible Infrared Imaging Radiometer Suite

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Authors: Kushal Kumar Chode, Remus Miahi Cirstea

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In recent times, the drive towards more efficient vehicles and the increase in the number of vehicle on the roads has driven the aerodynamic researchers from studying the vehicle in isolation towards understanding the benefits of vehicle platooning. Vehicle platooning is defined as a series of vehicles traveling in close proximity. Due to the limitations in size and load measurement capabilities for the wind tunnels facilities, it is very difficult to perform this investigation experimentally. In this paper, the use of chimera or overset meshing technique is used within the STARCCM+ software to model the flow surrounding two identical vehicle models travelling in close proximity and also during an overtaking maneuver. The results are compared with data obtained from a polyhedral mesh and identical physics conditions. The benefits in terms of computational time and resources and the accuracy of the overset mesh approach are investigated.

Keywords: chimera mesh, computational accuracy, overset mesh, platooning vehicles

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Authors: Hwang Ahreum, Kang Taejoon, Kim Bongsoo

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Nanosensors for high sensitive detection of diseases have been widely studied to improve the quality of life. Here, we suggest robust nano-plasmonic diagnostic sensor using cysteine tagged protein G (Cys3-protein G) and ultraflat, ultraclean and single-crystalline Au nanoplates. Protein G formed on an ultraflat Au surface provides ideal background for dense and uniform immobilization of antibodies. The Au is highly stable in diverse biochemical environment and can immobilize antibodies easily through Au-S bonding, having been widely used for various biosensing applications. Especially, atomically smooth single-crystalline Au nanomaterials synthesized using chemical vapor transport (CVT) method are very suitable to fabricate reproducible sensitive sensors. As the C-reactive protein (CRP) is a nonspecific biomarker of inflammation and infection, it can be used as a predictive or prognostic marker for various cardiovascular diseases. Cys3-protein G immobilized uniformly on the Au nanoplate enable CRP antibody (anti-CRP) to be ordered in a correct orientation, making their binding capacity be maximized for CRP detection. Immobilization condition for the Cys3-protein G and anti-CRP on the Au nanoplate is optimized visually by AFM analysis. Au nanoparticle - Au nanoplate (NPs-on-Au nanoplate) assembly fabricated from sandwich immunoassay for CRP can reduce zero-signal extremely caused by nonspecific bindings, providing a distinct surface-enhanced Raman scattering (SERS) enhancement still in 10-18 M of CRP concentration. Moreover, the NP-on-Au nanoplate sensor shows an excellent selectivity against non-target proteins with high concentration. In addition, comparing with control experiments employing a Au film fabricated by e-beam assisted deposition and linker molecule, we validate clearly contribution of the Au nanoplate for the attomolar sensitive detection of CRP. We expect that the devised platform employing the complex of single-crystalline Au nanoplates and Cys3-protein G can be applied for detection of many other cancer biomarkers.

Keywords: Au nanoplate, biomarker, diagnostic sensor, protein G, SERS

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Authors: Hanna Faron, Wojciech Marcinkowski, Daniel Prusak, Władysław Hamiga

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Interest in composite materials comes out of two basic premises: their supreme mechanical and strength properties,combined with a small specific weight. Origin and evolution of modern composite materials bonds with development of manufacturing of synthetic fibers, which have begun during Second World War. Main condition to achieve intended properties of composite materials is proper bonding of reinforcing layer with appropriate adhesive in manufacturing process. It is one of the fundamental quality evaluation criterion of fabrication processes.

Keywords: SAE, formula student, composite materials, carbon fiber, Aramid fiber, hot wire cutter

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Authors: Naima Mubeen

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Multi-ethnic societies play a crucial role in managing relevant policies and their implication. Pakistan is a classic case of multicultural identity, social evils and a wide-range of preferential ethnic policies. The major objectives of this study are to explore the relationship between ethnic diversity, globalization and export diversification of Pakistan. For empirical analysis of this underlying nexus by utilizing time series data from 1970 to 2016, this study used the autoregressive distributed lags (ARDL) technique. The empirical finding of this study reveals that ethnic diversity is an essential component for enhancing globalization and export diversification in the case of Pakistan. Regarding the promotion of globalization and export diversification at different forums of the country, this study suggested that government needs to take steps for the promotion of society towards more cohesiveness by fair justice-based system and awareness programs.

Keywords: ethnic diversity, social exclusion, globalization, export diversification

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Authors: Sara S. Fouad, Omneya Messallam

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In 1818, a seventy-five kilometer long canal was dug (called the Mahmoudiyah canal) connecting between Alexandria city in Egypt and the western branch of the Nile. It was a productive resource and vital to its environment, context, transportation, and recreation. It played a significant role in people’s lives and Alexandria city’s shape. The canal, which was the main vein of goods’ transporting from Alexandria’s seaport to the different parts of Egypt, was still in use today as a major source of clear water in the city. But nowadays, Mahmoudiyah canal is converting into ‘dead waterway’. The canal became sources of pollution as a result of solid and industrial waste thus causing many diseases, destroying communities and biodiversity, with urban invasion, the loss of community aesthetic value and healthy environment. Therefore, this paper aims to propose an urban strategy, as a solution to revive the forgotten canal, through recreating a cultural promenade on its shore. The main aim of this research is to formulate decent quality of life, unpolluted space, an area gathering the city space for nature, tourism and investments. As a case study, this paper investigates Mahmoudiyah canal through urban and ecological analyses, aiming to design an urban strategy for reviving it by creating a cultural promenade enriched with public spaces and green areas, which can most probably enhance the quality of life, city re-living and development. Community participation is also considered as vital and intrinsic implementation stage. The empirical research involved using several data assembly methods such as interviews, mental mapping, structural observations and questionnaires. The paper ends with a set of conclusions leading to proposals for the Mahmoudiyah canal revitalization considering the complex challenges and processes of sustainable regeneration focusing on city’s rehabilitation and lost identity.

Keywords: Mahmoudiyah canal, community aesthetic value, city re-living, cultural promenade

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Authors: Mohammed Ali

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In this paper, evaluation of flexible manufacturing system is made under different manufacturing strategies. The objective of this paper is to test the impact of pallets and routing flexibility on system performance operating at different sequencing rules, dispatching rules and at unbalanced load condition. A computer simulation model is developed to evaluate the effects of aforementioned manufacturing strategies on the make-span performance of flexible manufacturing system. The impact of number of pallets is shown with the different levels of routing flexibility. In this paper, the same manufacturing system is modeled under different combination of sequencing and dispatching rules. A series of simulation experiments are conducted and results analyzed. The result of the simulation shows that there is impact of pallets and routing flexibility on the performance of the system.

Keywords: flexibility, flexible manufacturing system, pallets, make-span, simulation

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Authors: Semih Sözer

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One of the most common issues in economic systems is understanding characteristics of economic activities in cities and regions. Although there are critics to economic base models in conceptual and empirical aspects, these models are useful tools to examining the economic structure of a nation, regions or cities. This paper uses one of the methodologies of economic base models namely the location quotients model. Data for this model includes employment numbers of provinces and NUTS II regions in Turkey. Time series of data covers the years of 1990, 2000, 2003, and 2009. Aim of this study is finding which sectors are export-base and which sectors are import-base in provinces and regions. Model results show that big provinces or powerful regions (population, size etc.) mostly have basic sectors in their economic system. However, interesting facts came from different sectors in different provinces and regions in the model results.

Keywords: economic base, location quotients model, regional economics, regional development

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Authors: Pieter C. M. Cornelis

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European theme parks invest approximately 10 percent of their yearly turnover into new rides and park improvements. Without these investments these parks assume not to be a very competitive and appealing daytrip for their target audiences. However, the impact of investments in attracting new visitors is not well-known and seems to differ dramatically between parks. This paper presents a case study from the Netherlands in which a small amusement park applied a suggested, not yet proven, investment method. The results of the investment are discussed in (a) the form of return on investment and (b) the success of the predictions with regard to this investment. Suggestions for future research are presented.

Keywords: entertainment industry, innovation, investments, theme parks

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Authors: P. Satish Kumar, K. Ramakrishna, Ch. Lokeshwar Reddy, G. Sridhar

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This paper presents two different sequential switching hybrid-modulation strategies and implemented for cascaded multilevel inverters. Hybrid modulation strategies represent the combinations of Fundamental-Frequency Pulse Width Modulation (FFPWM) and Multilevel Sinusoidal-Modulation (MSPWM) strategies, and are designed for performance of the well-known Alternative Phase Opposition Disposition (APOD), Phase Shifted Carrier (PSC). The main characteristics of these modulations are the reduction of switching losses with good harmonic performance, balanced power loss dissipation among the devices with in a cell, and among the series-connected cells. The feasibility of these modulations is verified through spectral analysis, power loss analysis and simulation.

Keywords: cascaded multilevel inverters, hybrid modulation, power loss analysis, pulse width modulation

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Authors: Qiong Huang, Satish Chand

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This paper uses a primary data from 670 Chinese manufacturing firms, together with the newly introduced regressionbased inequality decomposition method, to study the effect of openness on wage inequality. We find that openness leads to a positive industry wage premium, but its contribution to firm-level wage inequality is relatively small, only 4.69%. The major contributor to wage inequality is human capital, which could explain 14.3% of wage inequality across sample firms.  

Keywords: openness, human capital, wage inequality, decomposition, China

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Authors: Allan Chia, Gabriel Gervais

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The case study on FoodXervices Inc shows how businesses need to reinvent and transform themselves in order to adapt and thrive and it also features how an SME can also devote resources to CSR causes. The company, Ng Chye Mong, was set up in 1937 and it went through ups and downs and encountered several failures and successes. In the 1970’s, the management of the company was entrusted to the next generation who continued to manage and expanded the business. In early 2003, the business encountered several challenges. A pair of siblings from the next generation of the Ng family joined the business fulltime and together they set-out to transform the company into FoodXervices Inc. In 2012, they started a charity, Food Bank Singapore Pte Ltd. The authors conducted case study research involving a series of in-depth interviews with the business owner and staff. This case study is an example of how to run a business and coordinate a charity concurrently while mobilising the same resources. The uniqueness of this case is the operational synergy of both the business and charity to promote corporate responsibility causes and initiatives in Singapore.

Keywords: family-owned business, charity, corporate social responsibility, branding

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Authors: Gurcan A. B., Baker T. N.

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Due to economic and environmental requirements, it is becoming increasingly important to reduce vehicle weight. The first approach consisted in using light materials with high thermal conductivity, such as aluminium alloys. This choice allowed significant mass reduction and lower temperature but required recourse to ventilated discs. Among aluminium alloys, Al 6xxx series alloys enjoy the highest strength-to-weight ratio and, therefore, have found wide applications in the automobile and aerospace industries. However, these alloys lose their high strength rapidly when they are exposed to elevated temperatures. This rapid decline in the strength is directly related to the coarsening of very fine precipitates which are then not as effective in obstructing the dislocations. The incorporation of micro-scale and nano-scale particulates in aluminium systems can greatly enhance their mechanical characteristics.

Keywords: mechanical and tribological behaviour, scanning electron microscope, optical test, mechanical properties test, experimental test

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Authors: Lucas Berrini

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Academic libraries have always struggled with engaging with students and faculty. Striking the balance between what the community needs and what the library can afford has also been a point of contention for libraries. As academia begins to return to a new normal after COVID, library staff are rethinking how remind patrons that the library is open and ready for business. NC Wesleyan, a small liberal arts school in eastern North Carolina, decided to be proactive and reach out to the academic community. After shutting down in 2020 for COVID, the campus library saw a marked decrease in in-person attendance. For a small school whose operational budget was tied directly to tuition payments, it was imperative for the library to remind faculty and staff that they were open for business. At the beginning of the Summer 2022 term and continuing into the fall, the reference team created a marketing plan using email, physical meetings, and virtual events targeted at students and faculty as well as community members who utilized the facilities prior to COVID. The email blasts were gentle reminders that the building was open and available for use The target audiences were the community at large. Several of the emails contained reminders of previous events in the library that were student centered. The next phase of the email campaign centers on reminding the community about the libraries physical and electronic resources, including the makerspace lab. Language will indicate that student voices are needed, and a QR code is included for students to leave feedback as to what they want to see in the library. The final phase of the email blasts were faculty focused and invited them to connect with library reference staff for an in-person consultation on their research needs. While this phase is ongoing, the response has been positive, and staff are compiling data in hopes of working with administration to implement some of the requested services and materials. These email blasts will be followed up by in-person meetings with faculty and students who responded to the QR codes. This research is ongoing. This type of targeted outreach is new for Wesleyan. It is the hope of the library that by the end of Fall 2022, there will be a plan in place to address the needs and concerns of the students and faculty. Furthermore, the staff hopes to create a new sense of community for the students and staff of the university.

Keywords: academic, education, libraries, outreach

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Authors: Ann P. Daunic, Nancy Corbett

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Background and Significance: Researchers emphasize the role that motivation, self-esteem, and self-regulation play in children’s early adjustment to the school culture, including skills such as identifying their own feelings and understanding the feelings of others. As social-emotional growth, academic learning, and successful integration within culture and society are inextricably connected, the Social-Emotional Learning Foundations (SELF) curriculum was designed to integrate social-emotional learning (SEL) instruction within early literacy instruction (specifically, reading) for Kindergarten and first-grade students at risk for emotional and behavioral difficulties. Storybook reading is a typically occurring activity in the primary grades; thus SELF provides an intervention that is both theoretically and practically sound. Methodology: The researchers will report on findings from the first two years of a three-year study funded by the US Department of Education’s Institute of Education Sciences to evaluate the effects of the SELF curriculum versus “business as usual” (BAU). SELF promotes the development of self-regulation by incorporating instructional strategies that support children’s use of SEL related vocabulary, self-talk, and critical thinking. The curriculum consists of a carefully coordinated set of materials and pedagogy designed specifically for primary grade children at early risk for emotional and behavioral difficulties. SELF lessons (approximately 50 at each grade level) are organized around 17 SEL topics within five critical competencies. SELF combines whole-group (the first in each topic) and small-group lessons (the 2nd and 3rd in each topic) to maximize opportunities for teacher modeling and language interactions. The researchers hypothesize that SELF offers a feasible and substantial opportunity within the classroom setting to provide a small-group social-emotional learning intervention integrated with K-1 literacy-related instruction. Participating target students (N = 876) were identified by their teachers as potentially at risk for emotional or behavioral issues. These students were selected from 122 Kindergarten and 100 first grade classrooms across diverse school districts in a southern state in the US. To measure the effectiveness of the SELF intervention, the researchers asked teachers to complete assessments related to social-emotional learning and adjustment to the school culture. A social-emotional learning related vocabulary assessment was administered directly to target students receiving small-group instruction. Data were analyzed using a 3-level MANOVA model with full information maximum likelihood to estimate coefficients and test hypotheses. Major Findings: SELF had significant positive effects on vocabulary, knowledge, and skills associated with social-emotional competencies, as evidenced by results from the measures administered. Effect sizes ranged from 0.41 for group (SELF vs. BAU) differences in vocabulary development to 0.68 for group differences in SEL related knowledge. Conclusion: Findings from two years of data collection indicate that SELF improved outcomes related to social-emotional learning and adjustment to the school culture. This study thus supports the integration of SEL with literacy instruction as a feasible and effective strategy to improve outcomes for K-1 students at risk for emotional and behavioral difficulties.

Keywords: Socio-cultural context for learning, social-emotional learning, social skills, vocabulary development

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Authors: Dario Milani, Guido Morgenthal

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Fluid dynamic computation of wind caused forces on bluff bodies e.g light flexible civil structures or high incidence of ground approaching airplane wings, is one of the major criteria governing their design. For such structures a significant dynamic response may result, requiring the usage of small scale devices as guide-vanes in bridge design to control these effects. The focus of this paper is on the numerical simulation of the bluff body problem involving multiscale phenomena induced by small scale devices. One of the solution methods for the CFD simulation that is relatively successful in this class of applications is the Vortex Particle Method (VPM). The method is based on a grid free Lagrangian formulation of the Navier-Stokes equations, where the velocity field is modeled by particles representing local vorticity. These vortices are being convected due to the free stream velocity as well as diffused. This representation yields the main advantages of low numerical diffusion, compact discretization as the vorticity is strongly localized, implicitly accounting for the free-space boundary conditions typical for this class of FSI problems, and a natural representation of the vortex creation process inherent in bluff body flows. When the particle resolution reaches the Kolmogorov dissipation length, the method becomes a Direct Numerical Simulation (DNS). However, it is crucial to note that any solution method aims at balancing the computational cost against the accuracy achievable. In the classical VPM method, if the fluid domain is discretized by Np particles, the computational cost is O(Np2). For the coupled FSI problem of interest, for example large structures such as long-span bridges, the aerodynamic behavior may be influenced or even dominated by small structural details such as barriers, handrails or fairings. For such geometrically complex and dimensionally large structures, resolving the complete domain with the conventional VPM particle discretization might become prohibitively expensive to compute even for moderate numbers of particles. It is possible to reduce this cost either by reducing the number of particles or by controlling its local distribution. It is also possible to increase the accuracy of the solution without increasing substantially the global computational cost by computing a correction of the particle-particle interaction in some regions of interest. In this paper different strategies are presented in order to extend the conventional VPM method to reduce the computational cost whilst resolving the required details of the flow. The methods include temporal sub stepping to increase the accuracy of the particles convection in certain regions as well as dynamically re-discretizing the particle map to locally control the global and the local amount of particles. Finally, these methods will be applied on a test case and the improvements in the efficiency as well as the accuracy of the proposed extension to the method are presented. The important benefits in terms of accuracy and computational cost of the combination of these methods will be thus presented as long as their relevant applications.

Keywords: adaptation, fluid dynamic, remeshing, substepping, vortex particle method

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Authors: Robert Michael, Kayla Tobin, William Foster, Rachel Fairchild

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The COVID-19 pandemic has caused significant disruptions in education, particularly in the teaching of health and physical education (HPE). This study examined a cohort of teachers that experienced being a preservice and first-year teacher during various stages of the pandemic. Qualitative data collection was conducted by interviewing six teachers from different schools in the Eastern U.S. over a series of structured interviews. Thematic analysis was employed to analyze the data. The pandemic significantly impacted the way HPE was taught as schools shifted to virtual and hybrid models. Findings revealed five major themes: (a) You want me to teach HOW?, (b) PE without equipment and six feet apart, (c) Behind the Scenes, (d) They’re back…I became a behavior management guru, and (e) The Pandemic Crater. Overall, this study highlights the significant challenges faced by preservice and first-year teachers in teaching physical education during the pandemic and underscores the need for ongoing support and resources to help them adapt and succeed in these challenging circumstances.

Keywords: teacher education, preservice teachers, first year teachers, health and physical education

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Authors: Yang Liu

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The work team has been being adopted by the CCP for special missions in a limited time. Since the 18th National Congress of CCP, the unprecedented practice of the work team has had impacts beyond the original goal of poverty alleviation, their functions in village governance have still not been well studied. As the state agents that come from the outside of the village community, this article argues that the work team is a group that represents the coexistence of political, economic, and cultural capital, which contributes to effectively empower the state, and the village cadres and the peasants. For the state, more accurate bottom-up information could be collected by the work team, and policies could be made scientifically and implemented without distortion. For the village cadres, they can learn leadership skills and share more resources owned or mobilized by the work team. For the peasants, they have more access to participate the public affairs of their village and express their claims. The multiple empowerments have greatly improved the relationship among the state, the peasants, and the village cadres since a series of reforms from 1980s to 2000s that alienated the relationship among them.

Keywords: state, village cadre, empowerment, work team, peasants

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Authors: Muhammad Tahir Hassan, Stas Burek, Muhammad Asif, Mohamed Emad

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Industrial sector in Pakistan accounts for 25% of total energy consumption in the country. The performance of this sector has been severely affected due to the adverse effect of current energy crises in the country. Energy conservation potentials of Pakistan’s industrial sectors through energy management can save wasted energy which would ultimately leads to economic and environmental benefits. However due to lack of financial incentives of energy efficiency and absence of energy benchmarking within same industrial sectors are some of the main challenges in the implementation of energy management. In Pakistan, this area has not been adequately explored, and there is a lack of focus on the need for industrial energy efficiency and proper management. The main objective of this research is to evaluate the current energy management performance of Pakistani industrial sector and empirical investigation of the existence of various barriers to industrial energy efficiency. Data was collected from the respondents of 192 small and medium-sized enterprises (SME’s) of Pakistan i.e. foundries, textile, plastic industries, light engineering, auto and spare parts and ceramic manufacturers and analysed using Statistical Package for the Social Sciences (SPSS) software. Current energy management performance of manufacturing SME’s in Pakistan has been evaluated by employing two significant indicators, ‘Energy Management Matrix’ and ‘pay-off criteria’, with modified approach. Using the energy management matrix, energy management profiles of overall industry and the individual sectors have been drawn to assess the energy management performance and identify the weak and strong areas as well. Results reveal that, energy management practices in overall surveyed industries are at very low level. Energy management profiles drawn against each sector suggest that performance of textile sector is better among all the surveyed manufacturing SME’s. The empirical barriers to industrial energy efficiency have also been ranked according to the overall responses. The results further reveal that there is a significant relationship exists among the industrial size, sector type and nature of barriers to industrial energy efficiency for the manufacturing SME’s in Pakistan. The findings of this study may help the industries and policy makers in Pakistan to formulate a sustainable energy policy to support industrial energy efficiency keeping in view the actual existing energy efficiency scenario in the industrial sector.

Keywords: barriers, energy conservation, energy management profile, environment, manufacturing SME's of Pakistan

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Authors: Ursula D. C. Resende, Fabiano S. Bicalho, Sandro T. M. Gonçalves

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The growing demand for cheap and clean energy sources have been motivated by the study and development of distinct technologies and devices able to provide different amounts of energy. In order to supply energy for small loads, the energy from the electromagnetic spectrum can be harvested. This possibility is particularly interesting because this kind of energy is constantly available in the environment and the number of radiofrequency sources is permanently increasing, due to advances in telecommunications services. A rectenna, which is a combination of an antenna and a rectifier circuit, is an equipment that can efficiently perform the electromagnetic energy harvesting. However, since the amount of electromagnetic energy available in the environment is very small, limited values of power can be harvested by the rectenna. Therefore, several technical strategies have been investigated in order to increase this amount of power. In this work, a metamaterial electromagnetic lens is used to improve the electromagnetic energy harvesting. The rectenna investigated was designed and optimized to charge a Li-Ion battery using the electromagnetic energy from an internet Wi-Fi commercial router model TL-WR841HP operating in 2.45 GHz with maximal output power equal to 18 dBm. The rectenna consists of a high directive antenna, a double voltage rectifier circuit and a metamaterial lens. The printed antenna, constituted of two rectangular radiator elements, was projected and optimized by using the Computer Simulation Software (CST) in order to obtain high directivities and values of S11 parameter below -10 dB in 2.45 GHz. The antenna was printed over a double-sided copper fiberglass substrate, FR4, with characterized relative electric permittivity εr = 4.3 and tangent of losses δ = 0.01. The rectifier circuit, which incorporates a circuit for impedance matching and uses the Schottky diode HSMS-2852, was projected and optimized by using Advanced Design Software (ADS) and built over the same FR4 substrate. The metamaterial cell is composed of two Square Split Ring Resonator (S-SRR) and a thin wire in order to operate with negative values of εr and relative magnetic permeability in 2.45 GHz. In order to evaluate the performance of the purposed rectenna two experimental charging tests were performed, one without and other with the metamaterial lens. The result obtained demonstrate that the electromagnetic lens was able to significantly increase the levels of electric current delivered to the battery, approximately 44%.

Keywords: electromagnetic energy harvesting, electromagnetic lens, metamaterial, rectenna

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Authors: Gökçe Erdemir, İlhan Yaylım, Serap Erdem-Kuruca, Musa Mutlu Can

Abstract:

It has been determined that the main reason for the death of cancer disease is caused by metastases rather than the primary tumor. The cells that leave the primary tumor and enter the circulation and cause metastasis in the secondary organs are called "circulating tumor cells" (CTCs). The presence and number of circulating tumor cells has been associated with poor prognosis in many major types of cancer, including breast, prostate, and colorectal cancer. It is thought that knowledge of circulating tumor cells, which are seen as the main cause of cancer-related deaths due to metastasis, plays a key role in the diagnosis and treatment of cancer. The fact that tissue biopsies used in cancer diagnosis and follow-up are an invasive method and are insufficient in understanding the risk of metastasis and the progression of the disease have led to new searches. Liquid biopsy tests performed with a small amount of blood sample taken from the patient for the detection of CTCs are easy and reliable, as well as allowing more than one sample to be taken over time to follow the prognosis. However, since these cells are found in very small amounts in the blood, it is very difficult to capture them and specially designed analytical techniques and devices are required. Methods based on the biological and physical properties of the cells are used to capture these cells in the blood. Early diagnosis is very important in following the prognosis of tumors of epithelial origin such as breast, lung, colon and prostate. Molecules such as EpCAM, vimentin, and cytokeratins are expressed on the surface of cells that pass into the circulation from very few primary tumors and reach secondary organs from the circulation, and are used in the diagnosis of cancer in the early stage. For example, increased EpCAM expression in breast and prostate cancer has been associated with prognosis. These molecules can be determined in some blood or body fluids to be taken from patients. However, more sensitive methods are required to be able to determine when they are at a low level according to the course of the disease. The aim is to detect these molecules found in very few cancer cells with the help of sensitive, fast-sensing biosensors, first in breast cancer cells reproduced in vitro and then in blood samples taken from breast cancer patients. In this way, cancer cells can be diagnosed early and easily and effectively treated.

Keywords: electrochemical biosensors, breast cancer, circulating tumor cells, EpCAM, Vimentin, Cytokeratins

Procedia PDF Downloads 265

Authors: Cheng Xu, Rui Zhong

Abstract:

Utilizing a preregistered randomized experiment, this study explores the effects of anonymity and curated identity on trust within the Metaverse. Participants were randomly assigned to different conditions of anonymity and identity curation and engaged in a series of tasks designed to mirror the complexities of trust in real-world social interactions. Trust was measured using the classical trust game, allowing for a nuanced understanding of how these factors interact and influence trust. The findings reveal that higher levels of anonymity negatively impact trust, while identity curation can moderate this effect. Mechanism analysis uncovers how anonymity influences perceived reciprocity and group cohesion, and how curation can moderate these relationships. The results demonstrate a nuanced interaction between anonymity and trust, with variations across different curation levels. These insights provide a multifaceted understanding of trust within virtual environments, contributing valuable knowledge to the design, policy-making, and ethical considerations of the Metaverse

Keywords: metaverse, anonymity, curated identity, social behavior, trust

Procedia PDF Downloads 145

Authors: Abas Mohsenzadeh, Mina Arya, Kim Bolton

Abstract:

Catalytic combustion of hydrocarbons is an important technology developed to produce energy with minimum pollutant formation. The catalyst plays a key role in this process which operates at lower temperatures compared to conventional flame combustion. The energetics of the direct combustion of hydrocarbons (CH → C + H) on a series of metal surfaces including Ag, Au, Al, Cu, Rh, Pt, Pd, Ni, Fe and Co were investigated using density functional theory (DFT). Brønsted-Evans-Polanyi (BEP) and transition state scaling (TSS) correlations were proposed based on DFT calculations on the Ag, Au, Al, Cu, Rh, Pt and Pd surfaces. These correlations were then used to estimate the energetics on Fe, Ni and Co surfaces. Results showed that the estimated reaction and activation energies by BEP and TSS correlations on Fe, Ni and Co surfaces are in an excellent agreement with those obtained by DFT calculations. Therefore these correlations can be efficiently used to predict energetics of similar reactions on these surfaces without doing computationally costly transition state calculations. It was found that the activation barrier for CH dissociation follows the order Ag ˃ Au ˃ Al ˃ Cu ˃ Pt ˃ Pd ˃ Ni > Co > Rh > Fe. Also, BEP (with R2 value of 0.96) and TSS correlations (with R2 value of 0.99) support the results.

Keywords: BEP, DFT, hydrocarbon combustion, metal surfaces, TSS

Procedia PDF Downloads 261

Authors: Rafiuddin

Abstract:

Composite solid electrolyte of the salt and oxide type is an effective approach to improve the ionic conductivity in low and intermediate temperature regions. The conductivity enhancement in the composites occurs via interfaces. Because of their high ionic conduction, composite electrolytes have wide applications in different electrochemical devices such as solid-state batteries, solid oxide fuel cells, and electrochemical cells. In this work, a series of novel (1‒x) (CdI2‒Ag2CrO4)‒xAl2O3 composite solid electrolytes has been synthesized. The prepared materials were characterized by X‒ray diffraction, differential thermal analysis, and AC impedance spectroscopy. The impedance spectra show single semicircle representing the simultaneous contribution of grain and grain boundary. The conductivity increased with the increase of Al2O3 content and shows the maximum conductivity (σ= 0.0012 S cm‒1) for 30% of Al2O3 content at 30 ℃.

Keywords: composite solid electrolyte, X-ray diffraction, Impedance spectroscopy, ionic conductivity

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Authors: Seok Hong Min, Tae Kwon Ha

Abstract:

High-temperature deformation behavior of ferritic stainless steels such as STS 409L, STS 430J1L, and STS 429EM has been investigated in this study. Specimens with fully annealed microstructure were obtained by heat treatment. A series of load relaxation tests has been conducted on these samples at temperatures ranging from 200 to 900oC to construct flow curves in the strain rate range from 10-6 s-1 to 10-3 s-1. Strain hardening was not observed at high temperatures above 800oC in any stainless steels. Load relaxation behavior at the temperature was closely related with high-temperature mechanical properties such as the thermal fatigue and tensile behaviors. Load drop ratio of 436L stainless steel was much higher than that of the other steels. With increasing temperature, strength and load drop ratio of ferritic stainless steels showed entirely different trends.

Keywords: ferritic stainless steel, high temperature deformation, load relaxation, microstructure, strain rate sensitivity

Procedia PDF Downloads 339

Authors: A. Mourtzikou, D. Sygkridou, T. Georgakopoulos, G. Katsagounos, E. Stathatos

Abstract:

Over 60% highly transparent quasi-solid-state dye-sensitized solar cells (DSSCs) with dimension of 50x50 cm² were fabricated via inkjet printing process using nanocomposite inks as raw materials and tested under outdoor illumination conditions. The cells were electrically characterized, and their possible application to the shell of greenhouses was also examined. The panel design was in Z-interconnection, where the working electrode was inkjet printed on one conductive glass and the counter electrode on a second glass in a sandwich configuration. Silver current collective fingers were printed on the glasses to make the internal electrical connections. In that case, the adjacent cells were connected in series via silver fingers and finally insulated using a UV curing resin to protect them from the corrosive (I^-/I₃^-) redox couple of the electrolyte.

Keywords: Dye-sensitized solar panels, inkjet printing, quasi-solid state electrolyte, semi-transparency, scale up

Procedia PDF Downloads 147