Search results for: tuning range
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 6767

Search results for: tuning range

5477 An Investigation into the Social Determinants of Crowdfunding Effectiveness in developing, non-Western contexts: Some Evidence from Thailand

Authors: Khin Thi Htun, James Jain, Tim Andrews

Abstract:

This study examines the under-researched phenomenon of crowdfunding use and effectiveness in developing non-western markets. More precisely, using an institutional theoretical lens, the research explores the attitudes, motivations, and practice surrounding the initiation, development, and receipt of crowdfunding campaignsin a business context symptomatic of widely dissimilar regulatory, normative cognitive institutional ‘pillars’ to those studied – and utilized in practice - to date. As, in essence, a form of alternative finance, crowdfunding is used primarily to fund a wide range of projects through the securement of small amounts of money from a large pool of investors/participants. Being tied almost inextricably to e-commerce channels, the practice of crowdfunding typically sources its means and communicates the purpose of each venture mainly, though not exclusively, online. The wide range of projects supported to date span social entrepreneurship, community benefits initiatives, creative and artistic endeavors, assistance to disadvantaged social cohorts, and small business start-ups. Adopting a longitudinal, comparative approach, the study reported here embodies an investigation centered on six case start-up campaigns within the Thai societal context, covering a range of fundings calls and cause choices. Data was sourced from a variety of respondents using semi-structured interviews, observation (direct and participant), and company information. Results suggest that the motives and effectiveness of crowdfunding campaigns differ significantly in non-western consumer contexts from the norms that have evolved to date in mature Western contexts(particularly the US and UK). Specifically, whereas data on the different regulatory pressures showed relatively insignificant variation, the results regarding cognitive and, especially, normative dissimilarities between the Thai and US/UK institutional profiles surfaced potentially important differences with far-reaching implications. Particular issuesto emerge from our data concerned consumer motivation in terms of support and engagement with different types of campaigns. This was found to stem from social norms symptomatic of ‘collectivist’ and ‘relations based/particularist’ cultural assistance behavior, in turn, linked to deeply-held societal values regarding interpersonal network (‘in group’) reciprocity. This research serves to refine and extend the limited body of knowledge to date on crowdfunding by exploring the phenomenon in a non-western, non-developed country contextswhere social norms and values differ. This was achieved through uncovering and explicating the effects of cultural dissimilarity on motivation, decision-making, construed ethics, and general engagement with crowdfunding ideas. Implications for theory into e-marketing and cross-cultural marketing, as well as for practitioners seeking to develop effective crowdfunding campaigns in a Southeast Asian cultural environment, are discussed to conclude the paper.

Keywords: crowdfunding, national culture, e-marketing, cross-cultural business

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5476 Simon Says: What Should I Study?

Authors: Fonteyne Lot

Abstract:

SIMON (Study capacities and Interest Monitor is a freely accessible online self-assessment tool that allows secondary education pupils to evaluate their interests and capacities in order to choose a post-secondary major that maximally suits their potential. The tool consists of two broad domains that correspond with two general questions pupils ask: 'What study fields interest me?' and 'Am I capable to succeed in this field of study?'. The first question is addressed by a RIASEC-type interest inventory that links personal interests to post-secondary majors. Pupils are provided with a personal profile and an overview of majors with their degree of congruence. The output is dynamic: respondents can manipulate their score and they can compare their results to the profile of all fields of study. That way they are stimulated to explore the broad range of majors. To answer whether pupils are capable of succeeding in a preferred major, a battery of tests is provided. This battery comprises a range of factors that are predictive of academic success. Traditional predictors such as (educational) background and cognitive variables (mathematical and verbal skills) are included. Moreover, non-cognitive predictors of academic success (such as 'motivation', 'test anxiety', 'academic self-efficacy' and 'study skills') are assessed. These non-cognitive factors are generally not included in admission decisions although research shows they are incrementally predictive of success and are less discriminating. These tests inform pupils on potential causes of success and failure. More important, pupils receive their personal chances of success per major. These differential probabilities are validated through the underlying research on academic success of students. For example, the research has shown that we can identify 22 % of the failing students in psychology and educational sciences. In this group, our prediction is 95% accurate. SIMON leads more students to a suitable major which in turn alleviates student success and retention. Apart from these benefits, the instrument grants insight into risk factors of academic failure. It also supports and fosters the development of evidence-based remedial interventions and therefore gives way to a more efficient use of means.

Keywords: academic success, online self-assessment, student retention, vocational choice

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5475 Federated Knowledge Distillation with Collaborative Model Compression for Privacy-Preserving Distributed Learning

Authors: Shayan Mohajer Hamidi

Abstract:

Federated learning has emerged as a promising approach for distributed model training while preserving data privacy. However, the challenges of communication overhead, limited network resources, and slow convergence hinder its widespread adoption. On the other hand, knowledge distillation has shown great potential in compressing large models into smaller ones without significant loss in performance. In this paper, we propose an innovative framework that combines federated learning and knowledge distillation to address these challenges and enhance the efficiency of distributed learning. Our approach, called Federated Knowledge Distillation (FKD), enables multiple clients in a federated learning setting to collaboratively distill knowledge from a teacher model. By leveraging the collaborative nature of federated learning, FKD aims to improve model compression while maintaining privacy. The proposed framework utilizes a coded teacher model that acts as a reference for distilling knowledge to the client models. To demonstrate the effectiveness of FKD, we conduct extensive experiments on various datasets and models. We compare FKD with baseline federated learning methods and standalone knowledge distillation techniques. The results show that FKD achieves superior model compression, faster convergence, and improved performance compared to traditional federated learning approaches. Furthermore, FKD effectively preserves privacy by ensuring that sensitive data remains on the client devices and only distilled knowledge is shared during the training process. In our experiments, we explore different knowledge transfer methods within the FKD framework, including Fine-Tuning (FT), FitNet, Correlation Congruence (CC), Similarity-Preserving (SP), and Relational Knowledge Distillation (RKD). We analyze the impact of these methods on model compression and convergence speed, shedding light on the trade-offs between size reduction and performance. Moreover, we address the challenges of communication efficiency and network resource utilization in federated learning by leveraging the knowledge distillation process. FKD reduces the amount of data transmitted across the network, minimizing communication overhead and improving resource utilization. This makes FKD particularly suitable for resource-constrained environments such as edge computing and IoT devices. The proposed FKD framework opens up new avenues for collaborative and privacy-preserving distributed learning. By combining the strengths of federated learning and knowledge distillation, it offers an efficient solution for model compression and convergence speed enhancement. Future research can explore further extensions and optimizations of FKD, as well as its applications in domains such as healthcare, finance, and smart cities, where privacy and distributed learning are of paramount importance.

Keywords: federated learning, knowledge distillation, knowledge transfer, deep learning

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5474 Investigation of Mutagenicity and DNA Binding Properties of Metal-Free and Metallophthalocyanines Containing α-Napththolbenzein Groups on the Peripheral Positions

Authors: Meltem Betül Sağlam, Halil İbrahim Güler, Aykut Sağlam

Abstract:

In this work, phthalocyanine compounds containing α-naphtholbenzeinunits have been synthesized. Mutagenicity and DNA binding properties of the compounds were investigated by Salmonella/Microsome Assay and spectrophotometer. According to the results of the preliminary range finding tests, the compounds gave no toxic effect to all tester strain S. typhimurium TA98 and TA100 at doses of 500, 1100, 350, 500 and 750 µg/plate in the presence and absence of S9, respectively. This study showed that all compounds exhibited efficient DNA-binding activity. In conclusion, these non-toxic compounds may be used as effective DNA dyes for molecular biology studies.

Keywords: dye, mutagenicity, phthalocyanine, toxicity

Procedia PDF Downloads 223
5473 Wind Resource Classification and Feasibility of Distributed Generation for Rural Community Utilization in North Central Nigeria

Authors: O. D. Ohijeagbon, Oluseyi O. Ajayi, M. Ogbonnaya, Ahmeh Attabo

Abstract:

This study analyzed the electricity generation potential from wind at seven sites spread across seven states of the North-Central region of Nigeria. Twenty-one years (1987 to 2007) wind speed data at a height of 10m were assessed from the Nigeria Meteorological Department, Oshodi. The data were subjected to different statistical tests and also compared with the two-parameter Weibull probability density function. The outcome shows that the monthly average wind speeds ranged between 2.2 m/s in November for Bida and 10.1 m/s in December for Jos. The yearly average ranged between 2.1m/s in 1987 for Bida and 11.8 m/s in 2002 for Jos. Also, the power density for each site was determined to range between 29.66 W/m2 for Bida and 864.96 W/m2 for Jos, Two parameters (k and c) of the Weibull distribution were found to range between 2.3 in Lokoja and 6.5 in Jos for k, while c ranged between 2.9 in Bida and 9.9m/s in Jos. These outcomes points to the fact that wind speeds at Jos, Minna, Ilorin, Makurdi and Abuja are compatible with the cut-in speeds of modern wind turbines and hence, may be economically feasible for wind-to-electricity at and above the height of 10 m. The study further assessed the potential and economic viability of standalone wind generation systems for off-grid rural communities located in each of the studied sites. A specific electric load profile was developed to suite hypothetic communities, each consisting of 200 homes, a school and a community health center. Assessment of the design that will optimally meet the daily load demand with a loss of load probability (LOLP) of 0.01 was performed, considering 2 stand-alone applications of wind and diesel. The diesel standalone system (DSS) was taken as the basis of comparison since the experimental locations have no connection to a distribution network. The HOMER® software optimizing tool was utilized to determine the optimal combination of system components that will yield the lowest life cycle cost. Sequel to the analysis for rural community utilization, a Distributed Generation (DG) analysis that considered the possibility of generating wind power in the MW range in order to take advantage of Nigeria’s tariff regime for embedded generation was carried out for each site. The DG design incorporated each community of 200 homes, freely catered for and offset from the excess electrical energy generated above the minimum requirement for sales to a nearby distribution grid. Wind DG systems were found suitable and viable in producing environmentally friendly energy in terms of life cycle cost and levelised value of producing energy at Jos ($0.14/kWh), Minna ($0.12/kWh), Ilorin ($0.09/kWh), Makurdi ($0.09/kWh), and Abuja ($0.04/kWh) at a particluar turbine hub height. These outputs reveal the value retrievable from the project after breakeven point as a function of energy consumed Based on the results, the study demonstrated that including renewable energy in the rural development plan will enhance fast upgrade of the rural communities.

Keywords: wind speed, wind power, distributed generation, cost per kilowatt-hour, clean energy, North-Central Nigeria

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5472 Rapid Nanoparticle Formulation Development and Screening Using NanoFabTxTM Platform

Authors: Zhen Ye, Maryam Zaroudi, Elizabeth Aisenbrey, Nicolynn E. Davis, Peng Gao

Abstract:

Nanoparticles have been used as drug delivery systems in the treatment of life-threatening diseases for decades, but traditional formulation development methods are time consuming and labor intensive. Millipore Sigma has developed a platform¬¬– NanoFabTxTM¬¬– for rapid and reproducible formulation development and screening to ensure consistentnanoparticle characteristics. Reproducible and precise control of the development process for a range of nanoparticle formulations accelerates the introduction of novel formulations to the clinic.

Keywords: Bio platform, Formulation development, NanoFabTxTM, Drug delivery

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5471 Gestalt in Music and Brain: A Non-Linear Chaos Based Study with Detrended/Adaptive Fractal Analysis

Authors: Shankha Sanyal, Archi Banerjee, Sayan Biswas, Sourya Sengupta, Sayan Nag, Ranjan Sengupta, Dipak Ghosh

Abstract:

The term ‘gestalt’ has been widely used in the field of psychology which defined the perception of human mind to group any object not in part but as a 'unified' whole. Music, in general, is polyphonic - i.e. a combination of a number of pure tones (frequencies) mixed together in a manner that sounds harmonious. The study of human brain response due to different frequency groups of the acoustic signal can give us an excellent insight regarding the neural and functional architecture of brain functions. Hence, the study of music cognition using neuro-biosensors is becoming a rapidly emerging field of research. In this work, we have tried to analyze the effect of different frequency bands of music on the various frequency rhythms of human brain obtained from EEG data. Four widely popular Rabindrasangeet clips were subjected to Wavelet Transform method for extracting five resonant frequency bands from the original music signal. These frequency bands were initially analyzed with Detrended/Adaptive Fractal analysis (DFA/AFA) methods. A listening test was conducted on a pool of 100 respondents to assess the frequency band in which the music becomes non-recognizable. Next, these resonant frequency bands were presented to 20 subjects as auditory stimulus and EEG signals recorded simultaneously in 19 different locations of the brain. The recorded EEG signals were noise cleaned and subjected again to DFA/AFA technique on the alpha, theta and gamma frequency range. Thus, we obtained the scaling exponents from the two methods in alpha, theta and gamma EEG rhythms corresponding to different frequency bands of music. From the analysis of music signal, it is seen that loss of recognition is proportional to the loss of long range correlation in the signal. From the EEG signal analysis, we obtain frequency specific arousal based response in different lobes of brain as well as in specific EEG bands corresponding to musical stimuli. In this way, we look to identify a specific frequency band beyond which the music becomes non-recognizable and below which in spite of the absence of other bands the music is perceivable to the audience. This revelation can be of immense importance when it comes to the field of cognitive music therapy and researchers of creativity.

Keywords: AFA, DFA, EEG, gestalt in music, Hurst exponent

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5470 Height of Highway Embankment for Tolerable Residual Settlement of Loose Cohesionless Subsoil Overlain by Stronger Soil

Authors: Sharifullah Ahmed

Abstract:

Residual settlement of cohesionless or non-plastic soil of different strength underlying highway embankment overlain by stronger soil layer highway embankment is studied. A parametric study is carried out for different height of embankment and for different ESAL factor. The sum of elastic settlements of cohesionless subsoil due to axle induced stress and due to self-weight of pavement layers is termed as the residual settlement. The values of residual settlement (Sr) for different heights of road embankment (He) are obtained and presented as design charts for different SPT Value (N60) and ESAL factor. For rigid pavement and flexible pavement in approach to bridge or culvert, the tolerable residual settlement is 0.100m. This limit is taken as 0.200m for flexible pavement in general sections of highway without approach to bridge or culvert. A simplified guideline is developed for design of highway embankment underlain by very loose to loose cohesionless subsoil overlain by a stronger soil layer for limiting value of the residual settlement. In the current research study range of ESAL factor is 1-10 and range of SPT value (N60) is 1-10. That is found that, ground improvement is not required if the overlying stronger layer is minimum 1.5m and 4.0m for general road section of flexible pavement except bridge or culvert approach and for rigid pavement or flexible pavement in bridge or culvert approach. Tables and charts are included in the prepared guideline to obtain minimum allowable height of highway embankment to limit the residual settlement with in mentioned tolerable limit. Allowable values of the embankment height (He) are obtained corresponding to tolerable or limiting level of the residual settlement of loose subsoil for different SPT value, thickness of stronger layer (d) and ESAL factor. The developed guideline is may be issued to be used in assessment of the necessity of ground improvement in case of cohesionless subsoil underlying highway embankment overlain by stronger subsoil layer for limiting residual settlement. The ground improvement is only to be required if the residual settlement of subsoil is more than tolerable limit.

Keywords: axle pressure, equivalent single axle load, ground improvement, highway embankment, tolerable residual settlement

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5469 Ground Water Pollution Investigation around Çorum Stream Basin in Turkey

Authors: Halil Bas, Unal Demiray, Sukru Dursun

Abstract:

Water and ground water pollution at the most of the countries is important problem. Investigation of water pollution source must be carried out to save fresh water. Because fresh water sources are very limited and recent sources are not enough for increasing population of world. In this study, investigation was carried out on pollution factors effecting the quality of the groundwater in Çorum Stream Basin in Turkey. Effect of geological structure of the region and the interaction between the stream and groundwater was researched. For the investigation, stream and groundwater sampling were performed at rainy and dry seasons to see if there is a change on quality parameters. The results were evaluated by the computer programs and then graphics, distribution maps were prepared. Thus, degree of the quality and pollution were tried to understand. According to analysis results, because the results of streams and the ground waters are not so close to each other we can say that there is no interaction between the stream and the groundwater. As the irrigation water, the stream waters are generally in the range between C3S1 region and the ground waters are generally in the range between C3S1 and C4S2 regions according to US Salinity Laboratory Diagram. According to Wilcox diagram stream waters are generally good-permissible and ground waters are generally good permissible, doubtful to unsuitable and unsuitable type. Especially ground waters are doubtful to unsuitable and unsuitable types in dry season. It may be assumed that as the result of relative increase in concentration of salt minerals. Especially samples from groundwater wells bored close to gypsium bearing units have high hardness, electrical conductivity and salinity values. Thus for drinking and irrigation these waters are determined as unsuitable. As a result of these studies, it is understood that the groundwater especially was effected by the lithological contamination rather than the anthropogenic or the other types of pollution. Because the alluvium is covered by the silt and clay lithology it is not affected by the anthropogenic and the other foreign factors. The results of solid waste disposal site leachate indicate that this site would have a risk potential for pollution in the future. Although the parameters did not exceed the maximum dangerous values it does not mean that they will not be dangerous in the future, and this case must be taken into account.

Keywords: Çorum, environment, groundwater, hydrogeology, geology, pollution, quality, stream

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5468 Eco-Degradation and Phytodiversity of Pulicat Lagoon, Eastcoast of Southern India

Authors: Khasim Munir Bhasha Shaik

Abstract:

Pulicat Lake is the second largest brackish water lagoon after Chilika Lake of Orissa along the east coast of India. Estuaries and lagoons have brackish water which shows high biological productivity than fresh or sea water. Hence, it has a wide range of aquatic, terrestrial flora. The World Wide Fund for Nature declared it as a protected area. The present study aims to explore the flora of the lagoon along with the various threats for its eco-degradation which helps to plan necessary conservation methods.

Keywords: phytodiversity, pulicat lake, threats, conservation

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5467 Evaluation of Hydrocarbons in Tissues of Bivalve Mollusks from the Red Sea Coast

Authors: Asma Ahmed Aljohani, Mohammed Orif

Abstract:

The concentration of polycyclic aromatic hydrocarbons (PAH) in clam (A. glabrata) was examined in samples collected from Alseef Beach, 30 km south of Jeddah city. Gas chromatography-mass spectrometry (GC-MS) was used to analyse the 14 PAHs. The concentration of total PAHs was found to range from 11.521 to 40.149 ng/gdw with a mean concentration of 21.857 ng/gdw, which is lower compared to similar studies. The lower molecular weight PAHs with three rings comprised 18.14% of the total PAH concentrations in the clams, while the high molecular weight PAHs with four rings, five rings, and six rings account for 81.86%. Diagnostic ratios for PAH source distinction suggested pyrogenic or anthropogenic sources.

Keywords: bivalves, biomonitoring, hydrocarbons, PAHs

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5466 Creative Radio Advertising in Turkey

Authors: Mehmet Sinan Erguven

Abstract:

A number of authorities argue that radio is an outdated medium for advertising and does not have the same impact on consumers as it did in the past. This grim outlook on the future of radio has its basis in the audio-visual world that consumers now live in and the popularity of Internet-based marketing tools among advertising professionals. Nonetheless, consumers still appear to overwhelmingly prefer radio as an entertainment tool. Today, in Canada, 90% of all adults (18+) tune into the radio on a weekly basis, and they listen for 17 hours. Teens are the most challenging group for radio to capture as an audience, but still, almost 75% tune in weekly. One online radio station reaches more than 250 million registered listeners worldwide, and revenues from radio advertising in Australia are expected to grow at an annual rate of 3% for the foreseeable future. Radio is also starting to become popular again in Turkey, with a 5% increase in the listening rates compared to 2014. A major matter of concern always affecting radio advertising is creativity. As radio generally serves as a background medium for listeners, the creativity of the radio commercials is important in terms of attracting the attention of the listener and directing their focus on the advertising message. This cannot simply be done by using audio tools like sound effects and jingles. This study aims to identify the creative elements (execution formats appeals and approaches) and creativity factors of radio commercials in Turkey. As part of the study, all of the award winning radio commercials produced throughout the history of the Kristal Elma Advertising Festival were analyzed using the content analysis technique. Two judges (an advertising agency copywriter and an academic) coded the commercials. The reliability was measured according to the proportional agreement. The results showed that sound effects, jingles, testimonials, slices of life and announcements were the most common execution formats in creative Turkish radio ads. Humor and excitement were the most commonly used creative appeals while award-winning ads featured various approaches, such as surprise musical performances, audio wallpaper, product voice, and theater of the mind. Some ads, however, were found to not contain any creativity factors. In order to be accepted as creative, an ad must have at least one divergence factor, such as originality, flexibility, unusual/empathic perspective, and provocative questions. These findings, as well as others from the study, hold great value for the history of creative radio advertising in Turkey. Today, the nature of radio and its listeners is changing. As more and more people are tuning into online radio channels, brands will need to focus more on this relatively cheap advertising medium in the very near future. This new development will require that advertising agencies focus their attention on creativity in order to produce radio commercials for their customers that will differentiate them from their competitors.

Keywords: advertising, creativity, radio, Turkey

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5465 Numerical Study of Flow around Flat Tube between Parallel Walls

Authors: Hamidreza Bayat, Arash Mirabdolah Lavasani, Meysam Bolhasani, Sajad Moosavi

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Flow around a flat tube is studied numerically. Reynolds number is defined base on equivalent circular tube and it is varied in range of 100 to 300. Equations are solved by using finite volume method and results are presented in form of drag and lift coefficient. Results show that drag coefficient of flat tube is up to 66% lower than circular tube with equivalent diameter. In addition, by increasing l/D from 1 to 2, the drag coefficient of flat tube is decreased about 14-27%.

Keywords: laminar flow, flat-tube, drag coefficient, cross-flow, heat exchanger

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5464 Dry Sliding Wear Behaviour of Ti3SiC2 and the Effect of TiC on Its

Authors: Bendaoudi Seif-Eddine, Bounazef Mokhtar

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Wear behaviour of Ti3SiC2 coating in contact sliding under dry condition have been investigated on different pressures (0.1-0.8 MPa) at various speeds from 5 to 60 m/s. The ball-on-disc sliding-wear test was performed in ambient air with a relative humidity of 20%. An equation has been proposed to predict wear rates and describe sliding wear caused by Corundum ball on the studied material. The results show how the wear rate, measured by mass loss, varies in the range of (0.6 – 3.8 x E-6 mm3/Nm) with normal sliding distance under various test conditions; it increases with increasing load and rapidly with speed. The influence of TiC impurities on the wear behaviours was also investigated.

Keywords: ball-on-disc, dry-sliding, Ti3SiC2, wear

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5463 Homeless Population Modeling and Trend Prediction Through Identifying Key Factors and Machine Learning

Authors: Shayla He

Abstract:

Background and Purpose: According to Chamie (2017), it’s estimated that no less than 150 million people, or about 2 percent of the world’s population, are homeless. The homeless population in the United States has grown rapidly in the past four decades. In New York City, the sheltered homeless population has increased from 12,830 in 1983 to 62,679 in 2020. Knowing the trend on the homeless population is crucial at helping the states and the cities make affordable housing plans, and other community service plans ahead of time to better prepare for the situation. This study utilized the data from New York City, examined the key factors associated with the homelessness, and developed systematic modeling to predict homeless populations of the future. Using the best model developed, named HP-RNN, an analysis on the homeless population change during the months of 2020 and 2021, which were impacted by the COVID-19 pandemic, was conducted. Moreover, HP-RNN was tested on the data from Seattle. Methods: The methodology involves four phases in developing robust prediction methods. Phase 1 gathered and analyzed raw data of homeless population and demographic conditions from five urban centers. Phase 2 identified the key factors that contribute to the rate of homelessness. In Phase 3, three models were built using Linear Regression, Random Forest, and Recurrent Neural Network (RNN), respectively, to predict the future trend of society's homeless population. Each model was trained and tuned based on the dataset from New York City for its accuracy measured by Mean Squared Error (MSE). In Phase 4, the final phase, the best model from Phase 3 was evaluated using the data from Seattle that was not part of the model training and tuning process in Phase 3. Results: Compared to the Linear Regression based model used by HUD et al (2019), HP-RNN significantly improved the prediction metrics of Coefficient of Determination (R2) from -11.73 to 0.88 and MSE by 99%. HP-RNN was then validated on the data from Seattle, WA, which showed a peak %error of 14.5% between the actual and the predicted count. Finally, the modeling results were collected to predict the trend during the COVID-19 pandemic. It shows a good correlation between the actual and the predicted homeless population, with the peak %error less than 8.6%. Conclusions and Implications: This work is the first work to apply RNN to model the time series of the homeless related data. The Model shows a close correlation between the actual and the predicted homeless population. There are two major implications of this result. First, the model can be used to predict the homeless population for the next several years, and the prediction can help the states and the cities plan ahead on affordable housing allocation and other community service to better prepare for the future. Moreover, this prediction can serve as a reference to policy makers and legislators as they seek to make changes that may impact the factors closely associated with the future homeless population trend.

Keywords: homeless, prediction, model, RNN

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5462 Strong Microcapsules with Macroporous Polymer Shells

Authors: Eve S. A. Loiseau, Marion Frey, Yves Blickenstorfer, Fabian Niedermair, André R. Studart

Abstract:

Porous microcapsules have a broad range of applications that require a robust shell. We propose a new method to produce macroporous polymer capsules with controlled size, shell thickness, porosity and mechanical properties using co-flow flow-focusing glass capillary devices. The porous structure was investigated through SEM and the permeability through confocal microscopy. Compression tests on single capsules were performed. We obtained microcapsules with tailored permeability from open to close pores structures and able to withstand loads up to 150 g.

Keywords: microcapsules, micromechanics, porosity, polymer shells

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5461 A Review of Machine Learning for Big Data

Authors: Devatha Kalyan Kumar, Aravindraj D., Sadathulla A.

Abstract:

Big data are now rapidly expanding in all engineering and science and many other domains. The potential of large or massive data is undoubtedly significant, make sense to require new ways of thinking and learning techniques to address the various big data challenges. Machine learning is continuously unleashing its power in a wide range of applications. In this paper, the latest advances and advancements in the researches on machine learning for big data processing. First, the machine learning techniques methods in recent studies, such as deep learning, representation learning, transfer learning, active learning and distributed and parallel learning. Then focus on the challenges and possible solutions of machine learning for big data.

Keywords: active learning, big data, deep learning, machine learning

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5460 A 30 Year Audit of the Vascular Complications of Ports: Permanent Intravascular Access Devices

Authors: S. Kershaw, P. J. Barry, K. Webb

Abstract:

Background: Cystic Fibrosis (CF) is a chronic lung disease where patients have chronic lung infection punctuated by acute exacerbations that require intermittent intravenous (IV) antibiotics during their lives. With time, peripheral venous access can become difficult and limited. Accessing these veins can become arduous, traumatic, painful and unworkable. A permanent intravascular access device or Port is a small device that is inserted into the central venous system that allows the delivery of medicine eliminating the need for peripheral venous access. Ports represent a convenient and efficient method when venous access is required on a permanent basis however they are also associated with significant vascular complications. Superior Vena Cava Obstruction (SVCO) is a rare but significant vascular complication of ports in this setting. Objective: We aimed to look at a single CF centre’s experience of port-related SVCO over a thirty year period. Methods: Retrospective data was extracted using patient’s notes, electronic radiological reports and local databases over a period in excess of 30 years from 1982 to 2014. Results: 13 patients were identified with SVCO as a result of their port. 11 patients had CF (9 female, 2 male), one male patient had Primary Ciliary Dyskinesia and one female patient had severe Asthma. The mean port function was 1532 days (range 110 – 4049) and the mean age at SVCO was 24 years (range 11.1 to 36.5 years). The most common symptoms were facial oedema (n=8, 61.5%) and dilated veins (n=6, 46.2%). 7 patients had their Ports removed after SVCO. 6 patients underwent attempted stenting (46.2%) and 6 did not. 4 out of the 6 who underwent stenting required/had re-intervention. 3 of the 6 patients who underwent stenting had symptom resolution, however, 4 of the 6 patients who were not stented had symptom resolution also. Symptom resolution was not guaranteed with stenting and required re-intervention in two-thirds. Conclusion: This case series represents the experience of one of the longest established CF units in the UK and represents the largest cohort ever reported in the literature.

Keywords: ports, Superior Vena Cava Obstruction, cystic fibrosis, access devices

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5459 Controllable Modification of Glass-Crystal Composites with Ion-Exchange Technique

Authors: Andrey A. Lipovskii, Alexey V. Redkov, Vyacheslav V. Rusan, Dmitry K. Tagantsev, Valentina V. Zhurikhina

Abstract:

The presented research is related to the development of recently proposed technique of the formation of composite materials, like optical glass-ceramics, with predetermined structure and properties of the crystalline component. The technique is based on the control of the size and concentration of the crystalline grains using the phenomenon of glass-ceramics decrystallization (vitrification) induced by ion-exchange. This phenomenon was discovered and explained in the beginning of the 2000s, while related theoretical description was given in 2016 only. In general, the developed theory enables one to model the process and optimize the conditions of ion-exchange processing of glass-ceramics, which provide given properties of crystalline component, in particular, profile of the average size of the crystalline grains. The optimization is possible if one knows two dimensionless parameters of the theoretical model. One of them (β) is the value which is directly related to the solubility of crystalline component of the glass-ceramics in the glass matrix, and another (γ) is equal to the ratio of characteristic times of ion-exchange diffusion and crystalline grain dissolution. The presented study is dedicated to the development of experimental technique and simulation which allow determining these parameters. It is shown that these parameters can be deduced from the data on the space distributions of diffusant concentrations and average size of crystalline grains in the glass-ceramics samples subjected to ion-exchange treatment. Measurements at least at two temperatures and two processing times at each temperature are necessary. The composite material used was a silica-based glass-ceramics with crystalline grains of Li2OSiO2. Cubical samples of the glass-ceramics (6x6x6 mm3) underwent the ion exchange process in NaNO3 salt melt at 520 oC (for 16 and 48 h), 540 oC (for 8 and 24 h), 560 oC (for 4 and 12 h), and 580 oC (for 2 and 8 h). The ion exchange processing resulted in the glass-ceramics vitrification in the subsurface layers where ion-exchange diffusion took place. Slabs about 1 mm thick were cut from the central part of the samples and their big facets were polished. These slabs were used to find profiles of diffusant concentrations and average size of the crystalline grains. The concentration profiles were determined from refractive index profiles measured with Max-Zender interferometer, and profiles of the average size of the crystalline grains were determined with micro-Raman spectroscopy. Numerical simulation were based on the developed theoretical model of the glass-ceramics decrystallization induced by ion exchange. The simulation of the processes was carried out for different values of β and γ parameters under all above-mentioned ion exchange conditions. As a result, the temperature dependences of the parameters, which provided a reliable coincidence of the simulation and experimental data, were found. This ensured the adequate modeling of the process of the glass-ceramics decrystallization in 520-580 oC temperature interval. Developed approach provides a powerful tool for fine tuning of the glass-ceramics structure, namely, concentration and average size of crystalline grains.

Keywords: diffusion, glass-ceramics, ion exchange, vitrification

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5458 Development and Validation of First Derivative Method and Artificial Neural Network for Simultaneous Spectrophotometric Determination of Two Closely Related Antioxidant Nutraceuticals in Their Binary Mixture”

Authors: Mohamed Korany, Azza Gazy, Essam Khamis, Marwa Adel, Miranda Fawzy

Abstract:

Background: Two new, simple and specific methods; First, a Zero-crossing first-derivative technique and second, a chemometric-assisted spectrophotometric artificial neural network (ANN) were developed and validated in accordance with ICH guidelines. Both methods were used for the simultaneous estimation of the two closely related antioxidant nutraceuticals ; Coenzyme Q10 (Q) ; also known as Ubidecarenone or Ubiquinone-10, and Vitamin E (E); alpha-tocopherol acetate, in their pharmaceutical binary mixture. Results: For first method: By applying the first derivative, both Q and E were alternatively determined; each at the zero-crossing of the other. The D1 amplitudes of Q and E, at 285 nm and 235 nm respectively, were recorded and correlated to their concentrations. The calibration curve is linear over the concentration range of 10-60 and 5.6-70 μg mL-1 for Q and E, respectively. For second method: ANN (as a multivariate calibration method) was developed and applied for the simultaneous determination of both analytes. A training set (or a concentration set) of 90 different synthetic mixtures containing Q and E, in wide concentration ranges between 0-100 µg/mL and 0-556 µg/mL respectively, were prepared in ethanol. The absorption spectra of the training sets were recorded in the spectral region of 230–300 nm. A Gradient Descend Back Propagation ANN chemometric calibration was computed by relating the concentration sets (x-block) to their corresponding absorption data (y-block). Another set of 45 synthetic mixtures of the two drugs, in defined range, was used to validate the proposed network. Neither chemical separation, preparation stage nor mathematical graphical treatment were required. Conclusions: The proposed methods were successfully applied for the assay of Q and E in laboratory prepared mixtures and combined pharmaceutical tablet with excellent recoveries. The ANN method was superior over the derivative technique as the former determined both drugs in the non-linear experimental conditions. It also offers rapidity, high accuracy, effort and money saving. Moreover, no need for an analyst for its application. Although the ANN technique needed a large training set, it is the method of choice in the routine analysis of Q and E tablet. No interference was observed from common pharmaceutical additives. The results of the two methods were compared together

Keywords: coenzyme Q10, vitamin E, chemometry, quantitative analysis, first derivative spectrophotometry, artificial neural network

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5457 Nonlinear Response of Infinite Beams on a Multilayer Tensionless Extensible Geosynthetic – Reinforced Earth Bed under Moving Load

Authors: K. Karuppasamy

Abstract:

In this paper analysis of an infinite beam resting on multilayer tensionless extensible geosynthetic reinforced granular fill - poor soil system overlying soft soil strata under moving the load with constant velocity is presented. The beam is subjected to a concentrated load moving with constant velocity. The upper reinforced granular bed is modeled by a rough membrane embedded in Pasternak shear layer overlying a series of compressible nonlinear Winkler springs representing the underlying the very poor soil. The multilayer tensionless extensible geosynthetic layer has been assumed to deform such that at the interface the geosynthetic and the soil have some deformation. Nonlinear behavior of granular fill and the very poor soil has been considered in the analysis by means of hyperbolic constitutive relationships. Governing differential equations of the soil foundation system have been obtained and solved with the help of appropriate boundary conditions. The solution has been obtained by employing finite difference method by means of Gauss-Siedel iterative scheme. Detailed parametric study has been conducted to study the influence of various parameters on the response of soil – foundation system under consideration by means of deflection and bending moment in the beam and tension mobilized in the geosynthetic layer. These parameters include the magnitude of applied load, the velocity of the load, damping, the ultimate resistance of the poor soil and granular fill layer. The range of values of parameters has been considered as per Indian Railways conditions. This study clearly observed that the comparisons of multilayer tensionless extensible geosynthetic reinforcement with poor foundation soil and magnitude of applied load, relative compressibility of granular fill and ultimate resistance of poor soil has significant influence on the response of soil – foundation system. However, for the considered range of velocity, the response has been found to be insensitive towards velocity. The ultimate resistance of granular fill layer has also been found to have no significant influence on the response of the system.

Keywords: infinite beams, multilayer tensionless extensible geosynthetic, granular layer, moving load and nonlinear behavior of poor soil

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5456 Nanoindentation Studies of Metallic Cu-CuZr Composites Synthesized by Accumulative Roll Bonding

Authors: Ehsan Alishahi, Chuang Deng

Abstract:

Materials with microstructural heterogeneity have recently attracted dramatic attention in the materials science community. Although most of the metals are identified as crystalline, the new class of amorphous alloys, sometimes are known as metallic glasses (MGs), exhibited remarkable properties, particularly high mechanical strength and elastic limit. The unique properties of MGs led to the wide range of studies in developing and characterizing of new alloys or composites which met the commercial desires. In spite of applicable properties of MGs, commercializing of metallic glasses was limited due to a major drawback, the lack of ductility and sudden brittle failure mode. Hence, crystalline-amorphous (C-A) composites were introduced almost in 2000s as a toughening strategy to improve the ductility of MGs. Despite the considerable progress reported in previous studies, there are still challenges in both synthesis and characterization of metallic C-A composites. In this study, accumulative roll bonding (ARB) was used to synthesize bulk crystalline-amorphous composites starting from crystalline Cu-Zr multilayers. Due to the severe plastic deformation state, new CuZr phases were formed during the rolling process which was reflected in SEM-EDS analysis. EDS elemental analysis showed the variation in the composition of CuZr phases such as 38-62, 50-50 to 68-32 at Cu-Zr % respectively. Moreover, TEM with electron diffraction analysis indicated the presence of both crystalline and amorphous structures for the new formed CuZr phases. In addition to the microstructural analysis, the mechanical properties of the synthesized composites were studied using the nanoindentation technique. Hysitron Nanoindentation instrument was used to conduct nanoindentation tests with cube corner tip. The maximum load of 5000 µN was applied in load control mode to measure the elastic modulus and hardness of different phases. The trend of results indicated three distinct regimes of hardness and elastic modulus including pure Cu, pure Zr, and new formed CuZr phases. More specifically, pure Cu regions showed the lowest values for both nanoindentation hardness and elastic modulus while the CuZr phases take the highest values. Consequently, pure Zr was placed in the intermediate range which is harder than pure Cu but softer than CuZr phases. In overall, it was found that CuZr phases with higher hardness were nucleated during ARB process as a result of mechanical alloying phenomenon.

Keywords: ARB, crystalline-amorphous composites, mechanical alloying, nanoindentation hardness

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5455 Distribution and Population Status of Canis spp. Threats and Conservation in Lehri Nature Park, Salt Range, District Jhelum

Authors: Muhammad Saad, AzherBaig, Anwar Maqsood, Muhammad Waseem

Abstract:

The grey wolf has been ranked endangered and Asiatic jackal as near threatened in Pakistan. Scientific data on population and threats to these species are not available in Pakistan, which is required for their proper management and conservation. The present study was conducted to collect data on distribution range, population status and threats to both of these Canis species in Lehri Nature Park. The data were collected using direct observations and indirect signs in the field. The population of grey wolf and Asiatic jackal were scattered into pocket of the study area and its surroundings. The current population of grey wolf was estimated 06 individuals and that of Asiatic jackal 28 individuals in the study area. The present study showed that grey wolf and Asiatic jackal were distributed in the northern and southern part of the study area having dense vegetation cover of tress and shrub between the altitudes of 330 m and 515 m. The research finding revealed that the scrub forest is the most preferred habitat of both the species but due to anthropogenic pressure the scrub forest is under severe threat. The dominant trees species were Acacia modesta, Zizyphus nummularia, and Prosopis juliflora and shrubs species of Dodonea-viscosa, Calotropis procera and Adhatoda vasica. Urial is one of the natural prey species: their population is low due to a number of reasons and therefore the maximum dependence of the wolves was on the livestock of the local and nomadic shepherds. The main prey species in the livestock was goats and sheep. The interviews were conducted with the eye witnesses of wolf attacks including livestock being killed by 5-6 numbers of wolves in different hamlets in the study area. The killing rate of the livestock by the wolves was greater when the nomadic shepherds were present in the area and decreased when they left the area. Presence of nomadic shepherds and killing rate has relation with the shifting of the wolves from the study area. It is further concluded that the population of the grey wolf and Asiatic jackal has decreased over time due to less availability of the natural prey species and habitat destruction.

Keywords: wildlife ecology, population conservation, rehabilitation, conservation

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5454 Encoded Nanospheres for the Fast Ratiometric Detection of Cystic Fibrosis

Authors: Iván Castelló, Georgiana Stoica, Emilio Palomares, Fernando Bravo

Abstract:

We present herein two colour encoded silica nanospheres (2nanoSi) for the fluorescence quantitative ratiometric determination of trypsin in humans. The system proved to be a faster (minutes) method, with two times higher sensitivity than the state-of-the-art biomarkers based sensors for cystic fibrosis (CF), allowing the quantification of trypsin concentrations in a wide range (0-350 mg/L). Furthermore, as trypsin is directly related to the development of cystic fibrosis, different human genotypes, i.e. healthy homozygotic (> 80 mg/L), CF homozygotic (< 50 mg/L), and heterozygotic (> 50 mg/L), respectively, can be determined using our 2nanoSi nanospheres.

Keywords: cystic fibrosis, trypsin, quantum dots, biomarker, homozygote, heterozygote

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5453 Optically Active Material Based on Bi₂O₃@Yb³⁺, Nd³⁺ with High Intensity of Upconversion Luminescence in Red and Green Region

Authors: D. Artamonov, A. Tsibulnikova, I. Samusev, V. Bryukhanov, A. Kozhevnikov

Abstract:

The synthesis and luminescent properties of Yb₂O₃, Nd₂O₃@Bi₂O₃ complex with upconversion generation are discussed in this work. The obtained samples were measured in the visible region of the spectrum under excitation with a wavelength of 980 nm. The studies showed that the obtained complexes have a high degree of stability and intense luminescence in the wavelength range of 400-750 nm. Consideration of the time dependence of the intensity of the upconversion luminescence allowed us to conclude that the enhancement of the intensity occurs in the time interval from 5 to 30 min, followed by the appearance of a stationary mode.

Keywords: lasers, luminescence, upconversion photonics, rare earth metals

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5452 The Assessment of the Diabetes Mellitus Complications on Oral Health: A Longitudinal Study

Authors: Mimoza Canga, Irene Malagnino, Gresa Baboci, Edit Xhajanka, Vito Antonio Malagnino

Abstract:

Background: Diabetes mellitus is regarded as a very problematic chronic disease that has an effect on a considerable number of people around the world and it is straightforwardly associated with the oral health condition of the patients. Objective: The objective of this study is to analyze and evaluate the impact of diabetes mellitus on oral health. Materials and methods: In the present research were taken into consideration 300 patients with an age range of 11 to 80 years old. The study sample was composed of 191 males, respectively 63.7% of them and 109 females 36.3% of the participants. We divided them into seven age groups: 11-20, 21-30, 31-40, 41-50, 51-60, 61-70, and 71-80 years.This descriptive and analytical research was designed as a longitudinal study. Statistical analysis was performed using IBM SPSS 23.0 statistics. Results: The majority of patients participating in the study belonged to the age range from 41 to 50 years old, precisely 20.7% of them, while 27% of the patients were from 51 to 60 years old. Based on the present research, it resulted that 24.4% of the participant had high blood sugar values 250-300 mg/dl, whereas 19 % of the patients had very high blood sugar values 300-350 mg/dl. Based on the results of the current study, it was observed that 83.7% of patients were affected by gingivitis. In the current study, the significant finding is that 22% of patients had more than 7 teeth with dental caries and 21% of them had 5-7 teeth with dental caries, whereas 29% of the patients had 4-5 dental caries and the remaining 28% of them had 1-3 dental caries. The present study showed that most of the patients, 27% of them had lost more than 7 teeth and 22% of the participants had lost 5-7 teeth, whereas 31% of the patients had lost 4-5 teeth and only 20 % of them had lost 1-3 teeth. This study proved that high blood sugar values had a direct impact on the manifestation of gingivitis and there it was a strong correlation between them with P-value = .001. A strong correlation was found out between dental caries and high blood sugar values with P-value ˂.001. Males with diabetes mellitus were more affected by dental caries and this was proved by the P-value= .02, in comparison to females P-value=.03. The impact of high blood sugar values affects missing teeth and the correlation between them was statistically significant with P-value ˂ .001. Conclusion: The results of this study suggest that diabetes mellitus is a possible risk factor in oral health for the reason that Albanian patients over 51 years old, respectively 43% of them have over 5 teeth with dental caries as compared with 49% of the patients who had over 5 missing teeth, whereas the majority 83.7% of them suffered from gingivitis. This study asserts that patients who do not have periodical check-ups of diabetes mellitus are at significant risk of oral diseases.

Keywords: dental caries, diabetes mellitus, gingivitis, missing teeth

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5451 Evaluation of Zr/NH₄ClO₄ and Zr/KClO₄ Compositions for Development of Igniter for Ammonium Perchlorate and Hydroxyl-Terminated Polybutadiene Based Base Bleed System

Authors: Amir Mukhtar, Habib Nasir

Abstract:

To achieve an enhanced range of large calibre artillery a base bleed unit equipped with ammonium perchlorate and hydroxyl-terminated polybutadiene (AP/HTPB) based composite propellant grain is installed at the bottom of a projectile which produces jet of hot gasses and reduces base drag during flight of the projectile. Upon leaving the muzzle at very high muzzle velocity, due to sudden pressure drop, the propellant grain gets quenched. Therefore, base-bleed unit is equipped with an igniter to ensure ignition as well as reignition of the propellant grain. Pyrotechnic compositions based on Zr/NH₄ClO₄ and Zr/KClO₄ mixtures have been studied for the effect of fuel/oxidizer ratio and oxidizer type on ballistic properties. Calorific values of mixtures were investigated by bomb calorimeter, the average burning rate was measured by fuse wire technique at ambient conditions, and high-pressure closed vessel was used to record pressure-time profile, maximum pressure achieved (Pmax), time to achieve Pmax and differential pressure (dP/dt). It was observed that the 30, 40, 50 and 60 wt.% of Zr has a very significant effect on ballistic properties of mixtures. Compositions with NH₄ClO₄ produced higher values of Pmax, dP/dt and Calorific value as compared to Zr/KClO₄ based mixtures. Composition containing KClO₄ comparatively produced higher burning rate and maximum burning rate was recorded at 8.30 mm/s with 60 wt.% Zr in Zr/KClO₄ pyrotechnic mixture. Zr/KClO₄ with 50 wt. % of Zr was tests fired in igniter assembly by electric initiation method. Igniter assembly was test fired several times and average burning time of 3.5 sec with igniter mass burning rate of 6.85 g/sec was recorded. Igniter was finally fired on static and dynamic level with base bleed unit which gave successful ignition to the base bleed grain and extended range was achieved with 155 mm artillery projectile.

Keywords: base bleed, closed vessel, igniter, zirconium

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5450 Foil Bearing Stiffness Estimation with Pseudospectral Scheme

Authors: Balaji Sankar, Sadanand Kulkarni

Abstract:

Compliant foil gas lubricated bearings are used for the support of light loads in the order of few kilograms at high speeds, in the order of 50,000 RPM. The stiffness of the foil bearings depends both on the stiffness of the compliant foil and on the lubricating gas film. The stiffness of the bearings plays a crucial role in the stable operation of the supported rotor over a range of speeds. This paper describes a numerical approach to estimate the stiffness of the bearings using pseudo spectral scheme. Methodology to obtain the stiffness of the foil bearing as a function of weight of the shaft is given and the results are presented.

Keywords: foil bearing, simulation, numerical, stiffness estimation

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5449 Plasma Technology for Hazardous Biomedical Waste Treatment

Authors: V. E. Messerle, A. L. Mosse, O. A. Lavrichshev, A. N. Nikonchuk, A. B. Ustimenko

Abstract:

One of the most serious environmental problems today is pollution by biomedical waste (BMW), which in most cases has undesirable properties such as toxicity, carcinogenicity, mutagenicity, fire. Sanitary and hygienic survey of typical solid BMW, made in Belarus, Kazakhstan, Russia and other countries shows that their risk to the environment is significantly higher than that of most chemical wastes. Utilization of toxic BMW requires use of the most universal methods to ensure disinfection and disposal of any of their components. Such technology is a plasma technology of BMW processing. To implement this technology a thermodynamic analysis of the plasma processing of BMW was fulfilled and plasma-box furnace was developed. The studies have been conducted on the example of the processing of bone. To perform thermodynamic calculations software package Terra was used. Calculations were carried out in the temperature range 300 - 3000 K and a pressure of 0.1 MPa. It is shown that the final products do not contain toxic substances. From the organic mass of BMW synthesis gas containing combustible components 77.4-84.6% was basically produced, and mineral part consists mainly of calcium oxide and contains no carbon. Degree of gasification of carbon reaches 100% by the temperature 1250 K. Specific power consumption for BMW processing increases with the temperature throughout its range and reaches 1 kWh/kg. To realize plasma processing of BMW experimental installation with DC plasma torch of 30 kW power was developed. The experiments allowed verifying the thermodynamic calculations. Wastes are packed in boxes weighing 5-7 kg. They are placed in the box furnace. Under the influence of air plasma flame average temperature in the box reaches 1800 OC, the organic part of the waste is gasified and inorganic part of the waste is melted. The resulting synthesis gas is continuously withdrawn from the unit through the cooling and cleaning system. Molten mineral part of the waste is removed from the furnace after it has been stopped. Experimental studies allowed determining operating modes of the plasma box furnace, the exhaust gases was analyzed, samples of condensed products were assembled and their chemical composition was determined. Gas at the outlet of the plasma box furnace has the following composition (vol.%): CO - 63.4, H2 - 6.2, N2 - 29.6, S - 0.8. The total concentration of synthesis gas (CO + H2) is 69.6%, which agrees well with the thermodynamic calculation. Experiments confirmed absence of the toxic substances in the final products.

Keywords: biomedical waste, box furnace, plasma torch, processing, synthesis gas

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5448 Surface Enhanced Infrared Absorption for Detection of Ultra Trace of 3,4- Methylene Dioxy- Methamphetamine (MDMA)

Authors: Sultan Ben Jaber

Abstract:

Optical properties of molecules exhibit dramatic changes when adsorbed close to nano-structure metallic surfaces such as gold and silver nanomaterial. This phenomena opened a wide range of research to improve conventional spectroscopies efficiency. A well-known technique that has an intensive focus of study is surface-enhanced Raman spectroscopy (SERS), as since the first observation of SERS phenomena, researchers have published a great number of articles about the potential mechanisms behind this effect as well as developing materials to maximize the enhancement. Infrared and Raman spectroscopy are complementary techniques; thus, surface-enhanced infrared absorption (SEIRA) also shows a noticeable enhancement of molecules in the mid-IR excitation on nonmetallic structure substrates. In the SEIRA, vibrational modes that gave change in dipole moments perpendicular to the nano-metallic substrate enhanced 200 times greater than the free molecule’s modes. SEIRA spectroscopy is promising for the characterization and identification of adsorbed molecules on metallic surfaces, especially at trace levels. IR reflection-absorption spectroscopy (IRAS) is a well-known technique for measuring IR spectra of adsorbed molecules on metallic surfaces. However, SEIRA spectroscopy sensitivity is up to 50 times higher than IRAS. SEIRA enhancement has been observed for a wide range of molecules adsorbed on metallic substrates such as Au, Ag, Pd, Pt, Al, and Ni, but Au and Ag substrates exhibited the highest enhancement among the other mentioned substrates. In this work, trace levels of 3,4-methylenedioxymethamphetamine (MDMA) have been detected using gold nanoparticles (AuNPs) substrates with surface-enhanced infrared absorption (SEIRA). AuNPs were first prepared and washed, then mixed with different concentrations of MDMA samples. The process of fabricating the substrate prior SEIRA measurements included mixing of AuNPs and MDMA samples followed by vigorous stirring. The stirring step is particularly crucial, as stirring allows molecules to be robustly adsorbed on AuNPs. Thus, remarkable SEIRA was observed for MDMA samples even at trace levels, showing the rigidity of our approach to preparing SEIRA substrates.

Keywords: surface-enhanced infrared absorption (SEIRA), gold nanoparticles (AuNPs), amphetamines, methylene dioxy- methamphetamine (MDMA), enhancement factor

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