Search results for: Kassa Michael
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 660

Search results for: Kassa Michael

660 Khaya Cellulose Supported Copper Nanoparticles for Chemo Selective Aza-Michael Reactions

Authors: M. Shaheen Sarkar, M. Lutfor Rahman, Mashitah Mohd Yusoff

Abstract:

We prepared a highly active Khaya cellulose supported poly(hydroxamic acid) copper nanoparticles by the surface modification of Khaya cellulose through graft co-polymerization and subsequently amidoximation. The Cu-nanoparticle (0.05 mol% to 50 mol ppm) was selectively promoted Aza-Michael reaction of aliphatic amines to give the corresponding alkylated products at room temperature in methanol. The supported nanoparticle was easy to recover and reused seven times without significance loss of its activity.

Keywords: Aza-Michael, copper, cellulose, nanoparticles, poly(hydroxamic acid)

Procedia PDF Downloads 314
659 Bio-Furan Based Poly (β-Thioether Ester) Synthesized via Thiol-Michael Addition Polymerization with Tunable Structure and Properties

Authors: Daihui Zhang, Marie J. Dumont

Abstract:

A derivative of 5-hydroxymethylfurfural (HMF) was synthesized for the thiol-Michael addition reaction. The efficiency of the catalysts (base and nucleophiles) and side reactions during the thiol-Michael addition were investigated. Dimethylphenylphosphine efficiently initiated the thiol-Michael addition polymerization for synthesizing a series of bio-based furan polymers with different structure and properties. The benzene rings or hydroxyl groups present in the polymer chains increased the glass transition temperature (Tg) of poly (β-thioether ester). Additionally, copolymers with various compositions were obtained via adding different ratio of 1,6-hexanedithiols to 1,4-benzenedithiols. 1H NMR analysis revealed that experimental ratios of two dithiols monomers matched well with theoretical ratios. The occurrence of a reversible Diels-Alder reaction between furan rings and maleimide groups allowed poly (β-thioether ester) to be dynamically crosslinked. These polymers offer the potentials to produce materials from biomass that have both practical mechanical properties and reprocessing ability.

Keywords: copolymers, Diels-Alder reaction, hydroxymethylfurfural, Thiol-Michael addition

Procedia PDF Downloads 308
658 MATLAB Supported Learning and Students' Conceptual Understanding of Functions of Two Variables: Experiences from Wolkite University

Authors: Eyasu Gemech, Kassa Michael, Mulugeta Atnafu

Abstract:

A non-equivalent group's quasi-experiment research was conducted at Wolkite University to investigate MATLAB supported learning and students' conceptual understanding in learning Applied Mathematics II using four different comparative instructional approaches: MATLAB supported traditional lecture method, MATLAB supported collaborative method, only collaborative method, and only traditional lecture method. Four intact classes of mechanical engineering groups 1 and 2, garment engineering and textile engineering students were randomly selected out of eight departments. The first three departments were considered as treatment groups and the fourth one 'Textile engineering' was assigned as a comparison group. The departments had 30, 29, 35 and 32 students respectively. The results of the study show that there is a significant mean difference in students' conceptual understanding between groups of students learning through MATLAB supported collaborative method and the other learning approaches. Students who were learned through MATLAB technology-supported learning in combination with collaborative method were found to understand concepts of functions of two variables better than students learning through the other methods of learning. These, hence, are informative of the potential approaches universities would follow for a better students’ understanding of concepts.

Keywords: MATLAB supported collaborative method, MATLAB supported learning, collaborative method, conceptual understanding, functions of two variables

Procedia PDF Downloads 250
657 Detection and Tracking Approach Using an Automotive Radar to Increase Active Pedestrian Safety

Authors: Michael Heuer, Ayoub Al-Hamadi, Alexander Rain, Marc-Michael Meinecke

Abstract:

Vulnerable road users, e.g. pedestrians, have a high impact on fatal accident numbers. To reduce these statistics, car manufactures are intensively developing suitable safety systems. Hereby, fast and reliable environment recognition is a major challenge. In this paper we describe a tracking approach that is only based on a 24 GHz radar sensor. While common radar signal processing loses much information, we make use of a track-before-detect filter to incorporate raw measurements. It is explained how the Range-Doppler spectrum can help to indicated pedestrians and stabilize tracking even in occultation scenarios compared to sensors in series.

Keywords: radar, pedestrian detection, active safety, sensor

Procedia PDF Downloads 502
656 Electron-Ion Recombination of N^{2+} and O^{3+} Ions

Authors: Shahin A. Abdel-Naby, Asad T. Hassan, Stuart Loch, Michael Fogle, Negil R. Badnell, Michael S. Pindzola

Abstract:

Accurate and reliable laboratory astrophysical data for electron-ion recombination are needed for plasma modeling. Dielectronic recombination (DR) rate coefficients are calculated for boron-like nitrogen and oxygen ions using state-of-the-art multi-configuration Breit-Pauli atomic structure AUTOSTRUCTURE collisional package within the generalized collisional-radiative framework. The calculations are performed in intermediate coupling scheme associated with n = 0 (2  2) and n = 1 (2  3) core-excitations. Good agreements are found between the theoretically convoluted rate coefficients and the experimental measurements performed at CRYRING heavy-ion storage ring for both ions. Fitting coefficients for the rate coefficients are produced for these ions in the temperature range q2(102-107) K, where q is the ion charge before recombination.

Keywords: Atomic data, atomic processes, electron-ion collision, plasma

Procedia PDF Downloads 147
655 Irish Film Tourism, Neocolonialism and Star Wars: Charting a Course Towards Ecologically and Culturally Considered Representation and Tourism on Skellig Michael

Authors: Rachel Gough

Abstract:

In 2014, Skellig Michael, an island off Ireland’s western seaboard and UNESCO world heritage site became a major setting in Disney’s Star Wars franchise. The subsequent influx of tourists to the site has proven to be a point of contention nationally. The increased visitor numbers have uplifted certain areas of the local economy, the mainland, but have caused irreparable damage to historic monuments and to endangered bird populations who breed on the island. Recent research carried out by a state body suggests far-reaching and longterm negative impacts on the island’s culture and environment, should the association with the Star Wars franchise persist. In spite of this, the film has been widely endorsed by the Irish government as providing a vital economic boost to historically marginalised rural areas through film tourism. This paper argues quite plainly that what is taking place on Skellig is neocolonialism. Skellig Michael’s unique resources, its aesthetic qualities, its ecosystem, and its cultural currency have been sold by the state to a multinational corporation, who profit from their use. Meanwhile, locals are left to do their best to turn a market trend into sustainable business at the expense of culture ecology and community. This paper intends to be the first dedicated study into the psychogeographic and cultural impact of Skellig Michael’s deterioration as a result of film tourism. It will discuss the projected impact of this incident on Irish culture more broadly and finally will attempt to lay out a roadmap for more collaborative filmmaking and touristic approach, which allows local cultures and ecosystem’s to thrive without drastically inhibiting cultural production. This paper will ultimately find that the consequences of this representation call for a requirement to read tourism as a split concept — namely into what we might loosely call “eco-tourism” and more capital-based “profit-bottom-line tourism.”

Keywords: ecology, film tourism, neocolonialism, sustainability

Procedia PDF Downloads 177
654 The Effect of Relationship Marketing on Service Quality and Customer Satisfaction without Service Providers' Emotional Intelligence: The Case of the Insurance Industry in Ghana

Authors: Frank Frimpong Opuni, Michael Mba Allan, Kwame Adu-Gyamfi, Michael Sarkodie Baffoe

Abstract:

This paper assesses the effect of relationship marketing on service quality and customer satisfaction from the perspective of the moderating role of emotional intelligence in the insurance industry in Ghana. A descriptive quantitative research technique was employed. A random sample of 384 each of customers and service providers in 3 insurance firms in Accra were used as the source of data. According to findings, emotional intelligence makes a strong positive effect on relationship marketing at 5% significance level, r (283) = .817, p = .000. Though relationship marketing makes a strong positive effect on service quality (r = .767, p < .05) and customer satisfaction (r = .647, p < .05), this effect becomes insignificant (p > .05) when the effect of emotional intelligence on relationship marketing is controlled for. It is therefore recommended that insurance firms give priority to equipping their relationship employees with emotional intelligence to maximise service quality and customer satisfaction.

Keywords: relationship marketing, service quality, customer satisfaction, emotional intelligence

Procedia PDF Downloads 457
653 Understanding Barriers to Sports Participation as a Means of Achieving Sustainable Development in Michael Otedola College of Primary Education

Authors: Osifeko Olalekan Remigious, Osifeko Christiana Osikorede, Folarin Bolanle Eunice, Olugbenga Adebola Shodiya

Abstract:

During these difficult economic times, nations are looking for ways to improve their finances, preserve the environment as well as the socio-political climate and educational institutions, which are needed to increase their economy and preserve their sustainable development. Sport is one of the ways through which sustainable development can be achieved. The purpose of this study was to examine and understanding barriers to participation in sport. A total of 1,025 students were purposively selected from five schools (School of Arts and Social Sciences, School of Languages, School of Education, School of Sciences and School of Vocational and Technical Education) in Michael Otedola College of Primary Education (MOCPED). A questionnaire, with a tested reliability coefficient of 0.71, was used for data collection. The collected data were subjected to the descriptive survey research design. The findings showed that sports facilities, funding and lecture schedules were significant barriers to sports participation. It was recommended that sports facilities be provided by the Lagos State government.

Keywords: sports, sustainable development, Participation, State government, barriers

Procedia PDF Downloads 233
652 Assessment of the Contribution of Geographic Information System Technology in Non Revenue Water: Case Study Dar Es Salaam Water and Sewerage Authority Kawe - Mzimuni Street

Authors: Victor Pesco Kassa

Abstract:

This research deals with the assessment of the contribution of GIS Technology in NRW. This research was conducted at Dar, Kawe Mzimuni Street. The data collection was obtained from existing source which is DAWASA HQ. The interpretation of the data was processed by using ArcGIS software. The data collected from the existing source reveals a good coverage of DAWASA’s water network at Mzimuni Street. Most of residents are connected to the DAWASA’s customer service. Also the collected data revealed that by using GIS DAWASA’s customer Geodatabase has been improved. Through GIS we can prepare customer location map purposely for site surveying also this map will be able to show different type of customer that are connected to DAWASA’s water service. This is a perfect contribution of the GIS Technology to address and manage the problem of NRW in DAWASA. Finally, the study recommends that the same study should be conducted in other DAWASA’s zones such as Temeke, Boko and Bagamoyo not only at Kawe Mzimuni Street. Through this study it is observed that ArcGIS software can offer powerful tools for managing and processing information geographically and in water and sanitation authorities such as DAWASA.

Keywords: DAWASA, NRW, Esri, EURA, ArcGIS

Procedia PDF Downloads 58
651 Electrochemical Treatment and Chemical Analyses of Tannery Wastewater Using Sacrificial Aluminum Electrode, Ethiopia

Authors: Dessie Tibebe, Muluken Asmare, Marye Mulugeta, Yezbie Kassa, Zerubabel Moges, Dereje Yenealem, Tarekegn Fentie, Agmas Amare

Abstract:

The performance of electrocoagulation (EC) using Aluminium electrodes for the treatment of effluent-containing chromium metal using a fixed bed electrochemical batch reactor was studied. In the present work, the efficiency evaluation of EC in removing physicochemical and heavy metals from real industrial tannery wastewater in the Amhara region, collected from Bahirdar, Debre Brihan, and Haik, was investigated. The treated and untreated samples were determined by AAS and ICP OES spectrophotometers. The results indicated that selected heavy metals were removed in all experiments with high removal percentages. The optimal results were obtained regarding both cost and electrocoagulation efficiency with initial pH = 3, initial concentration = 40 mg/L, electrolysis time = 30 min, current density = 40 mA/cm2, and temperature = 25oC favored metal removal. The maximum removal percentages of selected metals obtained were 84.42% for Haik, 92.64% for Bahir Dar and 94.90% for Debre Brihan. The sacrificial electrode and sludge were characterized by FT-IR, SEM and XRD. After treatment, some metals like chromium will be used again as a tanning agent in leather processing to promote a circular economy.

Keywords: electrochemical, treatment, aluminum, tannery effluent

Procedia PDF Downloads 75
650 Investigation for Pixel-Based Accelerated Aging of Large Area Picosecond Photo-Detectors

Authors: I. Tzoka, V. A. Chirayath, A. Brandt, J. Asaadi, Melvin J. Aviles, Stephen Clarke, Stefan Cwik, Michael R. Foley, Cole J. Hamel, Alexey Lyashenko, Michael J. Minot, Mark A. Popecki, Michael E. Stochaj, S. Shin

Abstract:

Micro-channel plate photo-multiplier tubes (MCP-PMTs) have become ubiquitous and are widely considered potential candidates for next generation High Energy Physics experiments due to their picosecond timing resolution, ability to operate in strong magnetic fields, and low noise rates. A key factor that determines the applicability of MCP-PMTs in their lifetime, especially when they are used in high event rate experiments. We have developed a novel method for the investigation of the aging behavior of an MCP-PMT on an accelerated basis. The method involves exposing a localized region of the MCP-PMT to photons at a high repetition rate. This pixel-based method was inspired by earlier results showing that damage to the photocathode of the MCP-PMT occurs primarily at the site of light exposure and that the surrounding region undergoes minimal damage. One advantage of the pixel-based method is that it allows the dynamics of photo-cathode damage to be studied at multiple locations within the same MCP-PMT under different operating conditions. In this work, we use the pixel-based accelerated lifetime test to investigate the aging behavior of a 20 cm x 20 cm Large Area Picosecond Photo Detector (LAPPD) manufactured by INCOM Inc. at multiple locations within the same device under different operating conditions. We compare the aging behavior of the MCP-PMT obtained from the first lifetime test conducted under high gain conditions to the lifetime obtained at a different gain. Through this work, we aim to correlate the lifetime of the MCP-PMT and the rate of ion feedback, which is a function of the gain of each MCP, and which can also vary from point to point across a large area (400 $cm^2$) MCP. The tests were made possible by the uniqueness of the LAPPD design, which allows independent control of the gain of the chevron stacked MCPs. We will further discuss the implications of our results for optimizing the operating conditions of the detector when used in high event rate experiments.

Keywords: electron multipliers (vacuum), LAPPD, lifetime, micro-channel plate photo-multipliers tubes, photoemission, time-of-flight

Procedia PDF Downloads 144
649 Ama de Casa: Gender Division of Labor the Response to Environmental and Economic Constraints, Ecuador

Authors: Tyrus C. Torres, Michael Harris

Abstract:

In a coastal town of Ecuador, the role of women is commonly defined as an ama de casa, a woman who works in the house, raises children, and contributes to the community. This project, under the guidance of Dr. Michael Harris from the Florida Atlantic University, seeks to understand how the role of an ama de casa provides a secure environment for men and women, coexists with economic and environmental constraints that explain the origins of how this environment has been formed. The coastal community aspects of familia (family), trabajo (work), relación (relationships), machismo (masculinity), feminista (femininity), and the culture of Ecuador define the ways of life in a coastal setting. This ethnographic research project included the following methodologies: environment mapping, conducting interviews, surveys, participant observation, direct and indirect observations, and integration into daily life. Immersion into the daily life and building relationships with the local people allowed the documentation of intricacies of both the cultural and social spheres. The findings of this research offer insight on how culture, economics, and environment can form female and male agency. Our investigation shows that occupations such as fishermen, laborers, ama de casas, and even students utilize occupational routes to create social agency in the face of economic and environmental constraints in Ecuador.

Keywords: Ecuador, ethnography, gender division of labor, gender roles

Procedia PDF Downloads 214
648 Multimodal Database of Retina Images for Africa: The First Open Access Digital Repository for Retina Images in Sub Saharan Africa

Authors: Simon Arunga, Teddy Kwaga, Rita Kageni, Michael Gichangi, Nyawira Mwangi, Fred Kagwa, Rogers Mwavu, Amos Baryashaba, Luis F. Nakayama, Katharine Morley, Michael Morley, Leo A. Celi, Jessica Haberer, Celestino Obua

Abstract:

Purpose: The main aim for creating the Multimodal Database of Retinal Images for Africa (MoDRIA) was to provide a publicly available repository of retinal images for responsible researchers to conduct algorithm development in a bid to curb the challenges of ophthalmic artificial intelligence (AI) in Africa. Methods: Data and retina images were ethically sourced from sites in Uganda and Kenya. Data on medical history, visual acuity, ocular examination, blood pressure, and blood sugar were collected. Retina images were captured using fundus cameras (Foru3-nethra and Canon CR-Mark-1). Images were stored on a secure online database. Results: The database consists of 7,859 retinal images in portable network graphics format from 1,988 participants. Images from patients with human immunodeficiency virus were 18.9%, 18.2% of images were from hypertensive patients, 12.8% from diabetic patients, and the rest from normal’ participants. Conclusion: Publicly available data repositories are a valuable asset in the development of AI technology. Therefore, is a need for the expansion of MoDRIA so as to provide larger datasets that are more representative of Sub-Saharan data.

Keywords: retina images, MoDRIA, image repository, African database

Procedia PDF Downloads 92
647 Treatment and Characterization of Cadmium Metal From Textile Factory Wastewater by Electrochemical Process Using Aluminum Plate Electrode

Authors: Dessie Tibebe, Yeshifana Ayenew, Marye Mulugeta, Yezbie Kassa, Zerubabel Moges, Dereje Yenealem, Tarekegn Fentie, Agmas Amare, Hailu Sheferaw Ayele

Abstract:

Electrochemical treatment technology is a technique used for wastewater treatment due to its ability to eliminate impurities that are not easily removed by chemical processes. The objective of the study is the treatment and characterization of textile wastewater by an electrochemical process. The results obtained at various operational parameters indicated that at 20 minutes of electrochemical process at ( pH =7), initial concentration 10 mg/L, current density 37.5 mA/cm², voltage 9 v and temperature 25⁰C the highest removal efficiency was achieved. The kinetics of removal of selected metal by electrochemical treatment has been successfully described by the first-order rate equation. The results of microscopic techniques using SEM for the scarified electrode before treatment were uniform and smooth, but after the electrochemical process, the morphology was completely changed. This is due to the detection of the adsorbed aluminum hydroxide coming from adsorption of the conducting electrolyte, chemicals used in the experiments, alloying and the scrap impurities of the anode and cathode. The FTIR spectroscopic analysis broad bands at 3450 cm-¹ representing O-H functional groups, while the presence of H-O-H and Al-H groups are indicated by the bands at 2850-2750 cm-¹ and 1099 representing C-H functional groups.

Keywords: electrochemical, treatment, textile wastewater, kinetics, removal efficiency

Procedia PDF Downloads 62
646 Breaking Sensitivity Barriers: Perovskite Based Gas Sensors With Dimethylacetamide-Dimethyl Sulfoxide Solvent Mixture Strategy

Authors: Endalamaw Ewnu Kassa, Ade Kurniawan, Ya-Fen Wu, Sajal Biring

Abstract:

Perovskite-based gas sensors represent a highly promising materials within the realm of gas sensing technology, with a particular focus on detecting ammonia (NH3) due to its potential hazards. Our work conducted thorough comparison of various solvents, including dimethylformamide (DMF), DMF-dimethyl sulfoxide (DMSO), dimethylacetamide (DMAC), and DMAC-DMSO, for the preparation of our perovskite solution (MAPbI3). Significantly, we achieved an exceptional response at 10 ppm of ammonia gas by employing a binary solvent mixture of DMAC-DMSO. In contrast to prior reports that relied on single solvents for MAPbI3 precursor preparation, our approach using mixed solvents demonstrated a marked improvement in gas sensing performance. We attained enhanced surface coverage, a reduction in pinhole occurrences, and precise control over grain size in our perovskite films through the careful selection and mixtures of appropriate solvents. This study shows a promising potential of employing binary and multi-solvent mixture strategies as a means to propel advancements in gas sensor technology, opening up new opportunities for practical applications in environmental monitoring and industrial safety.

Keywords: sensors, binary solvents, ammonia, sensitivity, grain size, pinholes, surface coverage

Procedia PDF Downloads 66
645 Poly (Diphenylamine-4-Sulfonic Acid) Modified Glassy Carbon Electrode for Voltammetric Determination of Gallic Acid in Honey and Peanut Samples

Authors: Zelalem Bitew, Adane Kassa, Beyene Misgan

Abstract:

In this study, a sensitive and selective voltammetric method based on poly(diphenylamine-4-sulfonic acid) modified glassy carbon electrode (poly(DPASA)/GCE) was developed for determination of gallic acid. Appearance of an irreversible oxidative peak at both bare GCE and poly(DPASA)/GCE for gallic acid with about three folds current enhancement and much reduced potential at poly(DPASA)/GCE showed catalytic property of the modifier towards oxidation of gallic acid. Under optimized conditions, Adsorptive stripping square wave voltammetric peak current response of the poly(DPASA)/GCE showed linear dependence with gallic acid concentration in the range 5.00 × 10-7 − 3.00 × 10-4 mol L-1 with limit of detection of 4.35 × 10-9. Spike recovery results between 94.62-99.63, 95.00-99.80 and 97.25-103.20% of gallic acid in honey, raw peanut, and commercial peanut butter samples respectively, interference recovery results with less than 4.11% error in the presence of uric acid and ascorbic acid, lower LOD and relatively wider dynamic range than most of the previously reported methods validated the potential applicability of the method based on poly(DPASA)/GCE for determination of gallic acid real samples including in honey and peanut samples.

Keywords: gallic acid, diphenyl amine sulfonic acid, adsorptive anodic striping square wave voltammetry, honey, peanut

Procedia PDF Downloads 52
644 Development of a Telemedical Network Supporting an Automated Flow Cytometric Analysis for the Clinical Follow-up of Leukaemia

Authors: Claude Takenga, Rolf-Dietrich Berndt, Erling Si, Markus Diem, Guohui Qiao, Melanie Gau, Michael Brandstoetter, Martin Kampel, Michael Dworzak

Abstract:

In patients with acute lymphoblastic leukaemia (ALL), treatment response is increasingly evaluated with minimal residual disease (MRD) analyses. Flow Cytometry (FCM) is a fast and sensitive method to detect MRD. However, the interpretation of these multi-parametric data requires intensive operator training and experience. This paper presents a pipeline-software, as a ready-to-use FCM-based MRD-assessment tool for the daily clinical practice for patients with ALL. The new tool increases accuracy in assessment of FCM-MRD in samples which are difficult to analyse by conventional operator-based gating since computer-aided analysis potentially has a superior resolution due to utilization of the whole multi-parametric FCM-data space at once instead of step-wise, two-dimensional plot-based visualization. The system developed as a telemedical network reduces the work-load and lab-costs, staff-time needed for training, continuous quality control, operator-based data interpretation. It allows dissemination of automated FCM-MRD analysis to medical centres which have no established expertise for the benefit of an even larger community of diseased children worldwide. We established a telemedical network system for analysis and clinical follow-up and treatment monitoring of Leukaemia. The system is scalable and adapted to link several centres and laboratories worldwide.

Keywords: data security, flow cytometry, leukaemia, telematics platform, telemedicine

Procedia PDF Downloads 960
643 Approach to Establish Logistics as a Central Scientific Discipline of Tomorrow's Industry

Authors: Johannes Dregger, Michael Schmidt, Christian Prasse, Michael ten Hompel

Abstract:

Most of the today’s companies face increasing need to operate efficiently. Driven by global trends like shorter product cycles, mass customization and the rising speed of delivery, manufacturing value chains are becoming more and more distributed. Manufacturing processes are becoming highly integrated, e.g. 3D printing. All these changes are affecting companies´ organization. They are leading towards individual, small scale, and ad-hoc logistics processes and structures, and finally, towards a significant increase in the importance of logistics itself since traditional value chains transform into agile value networks. In the past logistics has been following manufacturing but in the future industry, this role allocation might change. With this increase in the logistics practice of companies and businesses, the relevance of logistics research as the methodological foundation of logistics networks and processes is gaining importance. Logistics research is evolving into a central and highly interdisciplinary science for the future industry. Using the example of Germany, this paper discusses ways to establish logistics as a central scientific discipline of the future industry. About three million people work in the logistics sector in Germany. Only automotive and retail industry have more employees. Even though there is a bunch of logistics degree programs at more than 100 institutions of higher education, a common understanding of logistics as a research discipline is missing. In this paper an innovative approach will be presented, including; identified perspectives on logistics, such as process orientation, IT orientation or employees orientation, relevant scientific disciplines for logistics science, a concept for interdisciplinary research approaches to unify the perspectives of the different scientific disciplines on logistics and the methodological base of logistics science.

Keywords: logistics, logistics science, logistics management, future challenges

Procedia PDF Downloads 291
642 Optical Variability of Faint Quasars

Authors: Kassa Endalamaw Rewnu

Abstract:

The variability properties of a quasar sample, spectroscopically complete to magnitude J = 22.0, are investigated on a time baseline of 2 years using three different photometric bands (U, J and F). The original sample was obtained using a combination of different selection criteria: colors, slitless spectroscopy and variability, based on a time baseline of 1 yr. The main goals of this work are two-fold: first, to derive the percentage of variable quasars on a relatively short time baseline; secondly, to search for new quasar candidates missed by the other selection criteria; and, thus, to estimate the completeness of the spectroscopic sample. In order to achieve these goals, we have extracted all the candidate variable objects from a sample of about 1800 stellar or quasi-stellar objects with limiting magnitude J = 22.50 over an area of about 0.50 deg2. We find that > 65% of all the objects selected as possible variables are either confirmed quasars or quasar candidates on the basis of their colors. This percentage increases even further if we exclude from our lists of variable candidates a number of objects equal to that expected on the basis of `contamination' induced by our photometric errors. The percentage of variable quasars in the spectroscopic sample is also high, reaching about 50%. On the basis of these results, we can estimate that the incompleteness of the original spectroscopic sample is < 12%. We conclude that variability analysis of data with small photometric errors can be successfully used as an efficient and independent (or at least auxiliary) selection method in quasar surveys, even when the time baseline is relatively short. Finally, when corrected for the different intrinsic time lags corresponding to a fixed observed time baseline, our data do not show a statistically significant correlation between variability and either absolute luminosity or redshift.

Keywords: nuclear activity, galaxies, active quasars, variability

Procedia PDF Downloads 50
641 Bionaut™: A Microrobotic Drug-Device Platform for the Local Treatment of Brainstem Gliomas

Authors: Alex Kiselyov, Suehyun Cho, Darrell Harrington; Florent Cros, Olin Palmer, John Caputo, Michael Kardosh, Eran Oren, William Loudon, Michael Shpigelmacher

Abstract:

Despite the most aggressive surgical and adjuvant therapeutic strategies, treatment of both pediatric and adult brainstem tumors remains problematic. Novel strategies, including targeted biologics, immunotherapy, and specialized delivery systems such as convection-enhanced delivery (CED), have been proposed. While some of these novel treatments are entering phase I trials, the field is still in need of treatment(s) that exhibits dramatically enhanced potency with optimal therapeutic ratio. Bionaut Labs has developed a modular microrobotic platform for performing localized delivery of diverse therapeutics in vivo. Our biocompatible particles (Bionauts™) are externally propelled and visualized in real-time. Bionauts™ are specifically designed to enhance the effect of radiation therapy via anatomically precise delivery of a radiosensitizing agent, as exemplified by temozolomide (TMZ) and Avastin™ to the brainstem gliomas of diverse origin. The treatment protocol is designed to furnish a better therapeutic outcome due to the localized (vs systemic) delivery of the drug to the neoplastic lesion(s) for use as a synergistic combination of radiation and radiosensitizing agent. In addition, the procedure is minimally invasive and is expected to be appropriate for both adult and pediatric patients. Current progress, including platform optimization, selection of the lead radiosensitizer as well as in vivo safety studies of the Bionauts™ in large animals, specifically the spine and the brain of porcine and ovine models, will be discussed.

Keywords: Bionaut, brainstem, glioma, local delivery, micro-robot, radiosensitizer

Procedia PDF Downloads 171
640 A Study of Basic and Reactive Dyes Removal from Synthetic and Industrial Wastewater by Electrocoagulation Process

Authors: Almaz Negash, Dessie Tibebe, Marye Mulugeta, Yezbie Kassa

Abstract:

Large-scale textile industries use large amounts of toxic chemicals, which are very hazardous to human health and environmental sustainability. In this study, the removal of various dyes from effluents of textile industries using the electrocoagulation process was investigated. The studied dyes were Reactive Red 120 (RR-120), Basic Blue 3 (BB-3), and Basic Red 46 (BR-46), which were found in samples collected from effluents of three major textile factories in the Amhara region, Ethiopia. For maximum removal, the dye BB-3 required an acidic pH 3, RR120 basic pH 11, while BR-46 neutral pH 7 conditions. BB-3 required a longer treatment time of 80 min than BR46 and RR-120, which required 30 and 40 min, respectively. The best removal efficiency of 99.5%, 93.5%, and 96.3% was achieved for BR-46, BB-3, and RR-120, respectively, from synthetic wastewater containing 10 mg L1of each dye at an applied potential of 10 V. The method was applied to real textile wastewaters and 73.0 to 99.5% removal of the dyes was achieved, Indicating Electrocoagulation can be used as a simple, and reliable method for the treatment of real wastewater from textile industries. It is used as a potentially viable and inexpensive tool for the treatment of textile dyes. Analysis of the electrochemically generated sludge by X-ray Diffraction, Scanning Electron Microscope, and Fourier Transform Infrared Spectroscopy revealed the expected crystalline aluminum oxides (bayerite (Al(OH)3 diaspore (AlO(OH)) found in the sludge. The amorphous phase was also found in the floc. Textile industry owners should be aware of the impact of the discharge of effluents on the Ecosystem and should use the investigated electrocoagulation method for effluent treatment before discharging into the environment.

Keywords: electrocoagulation, aluminum electrodes, Basic Blue 3, Basic Red 46, Reactive Red 120, textile industry, wastewater

Procedia PDF Downloads 30
639 Seroprevalence of Bovine Brucellosis and its Public Health Significance in Selected Sites of Central High Land of Ethiopia

Authors: Temesgen Kassa Getahun, Gezahegn Mamo, Beksisa Urge

Abstract:

A cross-sectional study was conducted from December 2019 to May 2020 with the aim of determining the seroprevalence of brucellosis in dairy cows and their owners in the central highland of Oromia, Ethiopia. A total of 352 blood samples from dairy cattle, 149 from animal owners, and 17 from farm workers were collected and initially screened using the Rose Bengal Plate test and confirmed by the Complement Fixation test. Overall seroprevalence was 0.6% (95% CI: 0.0016–0.0209) in bovines and 1.2% (95% CI: 0.0032–0.0427) in humans. Market-based stock replacement (OR=16.55, p=0.002), breeding by artificial insemination (OR=7.58, p=0.05), and parturition pen (OR = 11.511, p=0.027) were found to be significantly associated with the seropositivity for Brucella infection in dairy cattle. Human housing (OR=1.8, p=0.002), contact with an aborted fetus (OR=21.19, p=0.017), drinking raw milk from non-aborted (OR=24.99, p=0.012), aborted (OR=5.72, p=0.019) and retained fetal membrane (OR=4.22, p=0.029) cows had a significant influence on human brucellosis. A structured interview question was administered to 284 respondents. Accordingly, most respondents had no knowledge of brucellosis (93.3%), and in contrast, 90% of them consumed raw milk. In conclusion, the present seroprevalence study revealed that brucellosis was low among dairy cattle and exposed individuals in the study areas. However, since there were no control strategies implemented in the study areas, there is a potential risk of transmission of brucellosis in dairy cattle and the exposed human population in the study areas. Implementation of a test and slaughter strategy with compensation to farmers is recommended, while in the case of human brucellosis, continuous social training and implementing one health approach framework must be applied.

Keywords: abortion, bovine brucellosis, human brucellosis, risk factors, seroprevalence

Procedia PDF Downloads 81
638 Estimation Atmospheric parameters for Weather Study and Forecast over Equatorial Regions Using Ground-Based Global Position System

Authors: Asmamaw Yehun, Tsegaye Kassa, Addisu Hunegnaw, Martin Vermeer

Abstract:

There are various models to estimate the neutral atmospheric parameter values, such as in-suite and reanalysis datasets from numerical models. Accurate estimated values of the atmospheric parameters are useful for weather forecasting and, climate modeling and monitoring of climate change. Recently, Global Navigation Satellite System (GNSS) measurements have been applied for atmospheric sounding due to its robust data quality and wide horizontal and vertical coverage. The Global Positioning System (GPS) solutions that includes tropospheric parameters constitute a reliable set of data to be assimilated into climate models. The objective of this paper is, to estimate the neutral atmospheric parameters such as Wet Zenith Delay (WZD), Precipitable Water Vapour (PWV) and Total Zenith Delay (TZD) using six selected GPS stations in the equatorial regions, more precisely, the Ethiopian GPS stations from 2012 to 2015 observational data. Based on historic estimated GPS-derived values of PWV, we forecasted the PWV from 2015 to 2030. During data processing and analysis, we applied GAMIT-GLOBK software packages to estimate the atmospheric parameters. In the result, we found that the annual averaged minimum values of PWV are 9.72 mm for IISC and maximum 50.37 mm for BJCO stations. The annual averaged minimum values of WZD are 6 cm for IISC and maximum 31 cm for BDMT stations. In the long series of observations (from 2012 to 2015), we also found that there is a trend and cyclic patterns of WZD, PWV and TZD for all stations.

Keywords: atmosphere, GNSS, neutral atmosphere, precipitable water vapour

Procedia PDF Downloads 37
637 Identification and Classification of Stakeholders in the Transition to 3D Cadastre

Authors: Qiaowen Lin

Abstract:

The 3D cadastre is an inevitable choice to meet the needs of real cadastral management. Nowadays, more attention is given to the technical aspects of 3D cadastre, resulting in the imbalance within this field. To fulfill this research gap, the stakeholder, which has been regarded as the determining factor in cadastral change has been studied. Delphi method, Michael rating, and stakeholder mapping are used to identify and classify the stakeholders in 3D cadastre. It is concluded that the project managers should pay more attention to the interesting appeal of the key stakeholders and different coping strategies should be adopted to facilitate the transition to 3D cadastre.

Keywords: stakeholders, three dimension, cadastre, transtion

Procedia PDF Downloads 267
636 Artificial Intelligence Techniques for Enhancing Supply Chain Resilience: A Systematic Literature Review, Holistic Framework, and Future Research

Authors: Adane Kassa Shikur

Abstract:

Today’s supply chains (SC) have become vulnerable to unexpected and ever-intensifying disruptions from myriad sources. Consequently, the concept of supply chain resilience (SCRes) has become crucial to complement the conventional risk management paradigm, which has failed to cope with unexpected SC disruptions, resulting in severe consequences affecting SC performances and making business continuity questionable. Advancements in cutting-edge technologies like artificial intelligence (AI) and their potential to enhance SCRes by improving critical antecedents in the different phases have attracted the attention of scholars and practitioners. The research from academia and the practical interest of the industry have yielded significant publications at the nexus of AI and SCRes during the last two decades. However, the applications and examinations have been primarily conducted independently, and the extant literature is dispersed into research streams despite the complex nature of SCRes. To close this research gap, this study conducts a systematic literature review of 106 peer-reviewed articles by curating, synthesizing, and consolidating up-to-date literature and presents the state-of-the-art development from 2010 to 2022. Bayesian networks are the most topical ones among the 13 AI techniques evaluated. Concerning the critical antecedents, visibility is the first ranking to be realized by the techniques. The study revealed that AI techniques support only the first 3 phases of SCRes (readiness, response, and recovery), and readiness is the most popular one, while no evidence has been found for the growth phase. The study proposed an AI-SCRes framework to inform research and practice to approach SCRes holistically. It also provided implications for practice, policy, and theory as well as gaps for impactful future research.

Keywords: ANNs, risk, Bauesian networks, vulnerability, resilience

Procedia PDF Downloads 54
635 Healthcare Professionals' Utilization of Physical Exercise as a Strategy to Prevent Non-Communicable Diseases in Ethiopian Public Sector Hospitals

Authors: Jeanne Grace, Melkamu D. Kassa

Abstract:

Background: Despite the recognized benefits of physical exercise, including a reduction of health risk factor indicators, illness and deaths related to Non-Communicable Diseases (NCDs) like cardiovascular disease, diabetes, hypertension, and cancer, the extent of its recognition and use as a prevention strategy by healthcare professionals working in Ethiopian referral hospitals is unknown. Objective: This study explored healthcare professionals’ use of physical exercise as a non-communicable disease prevention strategy in the Ethiopian public sector healthcare system. Methods: In this cross-sectional study, a self-administered questionnaire was conducted after being piloted to ensure validity and reliability. For the study, 312 participants were selected from 13 purposively selected Ethiopian referral hospitals, these being 99 physicians who were purposively selected and 213 nurses who were proportionately and randomly selected. Results: The results indicated that three-quarters (78%) of healthcare professionals working in Ethiopian hospitals are not using physical exercise as a strategy to prevent NCDs. Increased specialization (AOR = 20.203, p < 0.001), longer service years (AOR = 0.041, p = 0.014), young age (AOR = 19.871, p < 0.001), and being male (AOR = 0.269, p < 0.001), were predictors of using physical exercise as a strategy for the prevention of NCDs. Conclusion: Healthcare professionals’ utilization of physical exercise as a strategy for NCDs prevention was inadequate in Ethiopia. Given the increasing burden of NCD disease in Ethiopia, training nurses, physicians and medical managers have to acknowledge the use of physical exercise as an NCD prevention strategy. The results of this study highlight the importance of formulating physical exercise intervention strategies for NCDs patients, and the need to incorporate training for healthcare professionals on the type, intensity, duration, and frequency of physical exercise to prevent NCDs in the Ethiopian healthcare system.

Keywords: exercise, medical managers, nurses, physicians

Procedia PDF Downloads 145
634 Tuning of Fixed Wing Micro Aerial Vehicles Using Tethered Setup

Authors: Shoeb Ahmed Adeel, Vivek Paul, K. Prajwal, Michael Fenelon

Abstract:

Techniques have been used to tether and stabilize a multi-rotor MAV but carrying out the same process to a fixed wing MAV is a novel method which can be utilized in order to reduce damage occurring to the fixed wing MAVs while conducting flight test trials and PID tuning. A few sensors and on board controller is required to carry out this experiment in horizontal and vertical plane of the vehicle. Here we will be discussing issues such as sensitivity of the air vehicle, endurance and external load of the string acting on the vehicle.

Keywords: MAV, PID tuning, tethered flight, UAV

Procedia PDF Downloads 615
633 Thorium-Doped PbS Thin Films for Radiation Damage Studies

Authors: Michael Shandalov, Tzvi Templeman, Michael Schmidt, Itzhak Kelson, Eyal Yahel

Abstract:

We present a new method to produce a model system for the study of radiation damage in non-radioactive materials. The method is based on homogeneously incorporating 228Th ions in PbS thin films using a small volume chemical bath deposition (CBD) technique. The common way to alloy metals with radioactive elements is by melting pure elements, which requires considerable amounts of radioactive material with its safety consequences such as high sample activity. Controlled doping of the thin films with (very) small amounts (100-200ppm) of radioactive elements such as thorium is expected to provide a unique path for studying radiation damage in materials due to decay processes without the need of sealed enclosure. As a first stage, we developed CBD process for controlled doping of PbS thin films (~100 nm thick) with the stable isotope (t1/2~106 years), 232Th. Next, we developed CBD process for controlled doping of PbS thin films with active 228Th isotope. This was achieved by altering deposition parameters such as temperature, pH, reagent concentrations and time. The 228Th-doped films were characterized using X-ray diffraction, which indicated a single phase material. Film morphology and thickness were determined using scanning electron microscopy (SEM). Energy dispersive spectroscopy (EDS) mapping in the analytical transmission electron microscope (A-TEM), X-ray photoelectron spectroscopy (XPS) depth profiles and autoradiography indicated that the Th ions were homogeneously distributed throughout the films, suggesting Pb substitution by Th ions in the crystal lattice. The properties of the PbS (228Th) film activity were investigated by using alpha-spectroscopy and gamma spectroscopy. The resulting films are applicable for isochronal annealing of resistivity measurements and currently under investigation. This work shows promise as a model system for the analysis of dilute defect systems in semiconductor thin films.

Keywords: thin films, doping, radiation damage, chemical bath deposition

Procedia PDF Downloads 369
632 Prioritizing Forest Conservation Strategies Using a Multi-Attribute Decision Model to Address Concerns with the Survival of the Endangered Dragon Tree (Dracaena ombet Kotschy and Peyr.)

Authors: Tesfay Gidey, Emiru Birhane, Ashenafi Manaye, Hailemariam Kassa, Tesfay Atsbha, Negasi Solomon, Hadgu Hishe, Aklilu Negussie, Petr Madera, Jose G. Borges

Abstract:

The globally endangered Dracaena ombet is one of the ten dragon multipurpose tree species in arid ecosystems. Anthropogenic and natural factors are now impacting the sustainability of the species. This study was conducted to prioritize criteria and alternative strategies for the conservation of the species using the analytical hierarchy process (AHP) model by involving all relevant stakeholders in the Desa'a dry Afromontane forest in northern Ethiopia. Information about the potential alternative strategies and the criteria for their evaluation was first collected from experts, personal experiences, and literature reviews. Afterward, they were validated using stakeholders' focus group discussions. Five candidate strategies with three evaluation criteria were considered for prioritization using the AHP techniques. The overall priority ranking value of the stakeholders showed that the ecological criterion was deemed as the most essential factor for the choice of alternative strategies, followed by the economic and social criteria. The minimum cut-off strategy, combining exclosures with the collection of only 5% of plant parts from the species, soil and water conservation, and silviculture interventions, was selected as the best alternative strategy for sustainable D. ombet conservation. The livelihood losses due to the selected strategy should be compensated by the collection of non-timber forest products, poultry farming, home gardens, rearing small ruminants, beekeeping, and agroforestry. This approach may be extended to study other dragon tree species and explore strategies for the conservation of other arid ecosystems.

Keywords: conservation strategies, analytical hierarchy process model, Desa'a forest, endangered species, Ethiopia, overexploitation

Procedia PDF Downloads 59
631 After Schubert’s Winterreise: Contemporary Aesthetic Journeys

Authors: Maria de Fátima Lambert

Abstract:

Following previous studies about Writing and Seeing, this paper focuses on the aesthetic assumptions within the concept of Winter Journey (Voyage d’Hiver/Winterreise) both in Georges Perec’s Saga and the Oulipo Group vis-à-vis with the creations by William Kentridge and Michael Borremans. The aesthetic and artistic connections are widespread. Nevertheless, we can identify common poetical principles shared by these different authors, not only according to the notion of ekphrasis, but also following the procedures of contemporary creation in literature and visual arts. The analysis of the ongoing process of the French writers as individuals and as group and the visual artists’ acting might contribute for another crossed definition of contemporary conception. The same title/theme was a challenge and a goal for them. Let’s wonder how deep the concept encouraged them and which symbolic upbringings were directing their poetical achievements. The idea of an inner journey became the main point, and got “over” and “across” a shared path worth to be followed. The authors were chosen due to the resilient contents of their visual and written images, and looking for the reasons that might had driven their conceptual basis to be. In Pérec’s “Winter Journey” as for the following fictions by Jacques Roubaud, Hervé le Tellier, Jacques Jouet and Hugo Vernier (that emerges from Perec’s fiction and becomes a real author) powerful aesthetic and enigmatic reflections grow connected with a poetic (and aesthetic) understanding of Walkscapes. They might be assumed as ironic fictions and poetical drifts. Outstanding from different logics, the overwhelming impact of Winterreise Lied by Schubert after Wilhelm Müller’s poems is a major reference in present authorship creations. Both Perec and Oulipo’s author’s texts are powerfully ekphrastic, although we should not forget they follow goals, frameworks and identities. When acting as a reader, they induce powerful imageries - cinematic or cinematographic - that flow in our minds. It was well-matched with William Kentridge animated video Winter Journey (2014) and the creations (sharing the same title) of Michael Borremans (2014) for the KlaraFestival, Bozar, Cité de la musique, in Belgium. Both were taken by the foremost Schubert’s Winterreise. Several metaphors fulfil new Winter Journeys (or Travels) that were achieved in contemporary art and literature, as it once succeeded in the 19th century. Maybe the contemporary authors and artists were compelled by the consciousness of nothingness, although outstanding different aesthetics and ontological sources. The unbearable knowledge of the road’s end, and also the urge of fulfilling the void might be a common element to all of them. As Schopenhauer once wrote, after all, Art is the only human subjective power that we can call upon in life. These newer aesthetic meanings, released from these winter journeys are surely open to wider approaches that might happen in other poetic makings to be.

Keywords: Aesthetic, voyage D’Hiver, George Perec & Oulipo, William Kentridge & Michael Borreman, Schubert's Winterreise

Procedia PDF Downloads 182