Search results for: twenty equivalent units

Authors: Irakli Gamkrelidze, David Shengelia, Tamara Tsutsunava, Giorgi Chichinadze, Giorgi Beridze, Ketevan Tedliashvili, Tamara Tsamalashvili

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The Loki crystalline massif crops out in the Caucasian region and the geological retrospective represent the northern marginal part of the Baiburt-Sevanian terrain (island arc), bordering with the Paleotethys oceanic basin in the north. The pre-Alpine basement of the massif is built up of Lower-Middle Paleozoic metamorphic complex (metasedimentary and metabasite rocks), Upper Devonian quartz-diorites and Late Variscan granites. Earlier metamorphic complex was considered as an indivisible set including suites with different degree of metamorphism. Systematic geologic, petrologic and geochemical investigations of the massif’s rocks suggest the different conception on composition, structure and formation conditions of the massif. In particular, there are two main rock types in the Loki massif: the oldest autochthonous series of gneissic quartz-diorites and cutting them granites. The massif is flanked on its western side by a volcano-sedimentary sequence, metamorphosed to low-T facies. Petrologic, metamorphic and structural differences in this sequence prove the existence of a number of discrete units (overthrust sheets). One of them, the metabasic sheet represents the fragment of ophiolite complex. It comprises transition types of the second and third layers of the Paleooceanic crust: the upper noncumulated part of the third layer gabbro component and the following lowest part of the parallel diabase dykes of the second layer. The ophiolites are represented by metagabbros, metagabbro-diabases, metadiabases and amphibolite schists. According to the content of petrogenic components and additive elements in metabasites is stated that the protolith of metabasites belongs to petrochemical type of tholeiitic series of basalts. The parental magma of metaophiolites is of E-MORB composition, and by petrochemical parameters, it is very close to the composition of intraplate basalts. The dykes of hypabissal leucocratic siliceous and medium magmatic rocks associated with the metaophiolite sheet form the separate complex. They are granitoids with the extremely low content of CaO and quartz-diorite porphyries. According to various petrochemical parameters, these rocks have mixed characteristics. Their formation took place in spreading conditions or in the areas of manifestation of plumes most likely of island arc type. The metamorphism degree of the metaophiolites corresponds to a very low stage of green schist facies. The rocks of the metaophiolite complex are obducted from the Paleotethys Ocean. Geological and paleomagnetic data show that the primary location of the ocean is supposed to be to the north of the Loki crystalline massif.

Keywords: the Caucasus, crystalline massif, ophiolites, tectonic sheet

Procedia PDF Downloads 277

Authors: Jungyeol Hong, Dongjoo Park

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The primary purpose of this study is to develop a methodological framework to predict daily subway ridership at a station-level and to examine the association between subway ridership and bus demand incorporating commercial business facility in the vicinity of each subway station. The socio-economic characteristics, land-use, and built environment as factors may have an impact on subway ridership. However, it should be considered not only the endogenous relationship between bus and subway demand but also the characteristics of commercial business within a subway station’s sphere of influence, and integrated transit network topology. Regarding a statistical approach to estimate subway ridership at a station level, therefore it should be considered endogeneity and heteroscedastic issues which might have in the subway ridership prediction model. This study focused on both discovering the impacts of bus demand, commercial business characteristics, and network topology on subway ridership and developing more precise subway ridership estimation accounting for its statistical bias. The spatial scope of the study covers entire Seoul city in South Korea and includes 243 stations with the temporal scope set at twenty-four hours with one-hour interval time panels each. The data for subway and bus ridership was collected Seoul Smart Card data from 2015 and 2016. Three-Stage Least Square(3SLS) approach was applied to develop daily subway ridership model as capturing the endogeneity and heteroscedasticity between bus and subway demand. Independent variables incorporating in the modeling process were commercial business characteristics, social-economic characteristics, safety index, transit facility attributes, and dummies for seasons and time zone. As a result, it was found that bus ridership and subway ridership were endogenous each other and they had a significantly positive sign of coefficients which means one transit mode could increase another transportation mode’s ridership. In other words, two transit modes of subway and bus have a mutual relationship instead of the competitive relationship. The commercial business characteristics are the most critical dimension among the independent variables. The variables of commercial business facility rate in the paper containing six types; medical, educational, recreational, financial, food service, and shopping. From the model result, a higher rate in medical, financial buildings, shopping, and food service facility lead to increment of subway ridership at a station, while recreational and educational facility shows lower subway ridership. The complex network theory was applied for estimating integrated network topology measures that cover the entire Seoul transit network system, and a framework for seeking an impact on subway ridership. The centrality measures were found to be significant and showed a positive sign indicating higher centrality led to more subway ridership at a station level. The results of model accuracy tests by out of samples provided that 3SLS model has less mean square error rather than OLS and showed the methodological approach for the 3SLS model was plausible to estimate more accurate subway ridership. Acknowledgement: This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Science and ICT (2017R1C1B2010175).

Keywords: subway ridership, bus ridership, commercial business characteristic, endogeneity, network topology

Procedia PDF Downloads 145

Authors: Raquel Dafouz Neus Cáceres, Javier Fernandez-Rubio, Belinda Huerta José Luis Rodríguez-Gil, Nicola Mastroianni, Miren López de Alda, Damià Barceló, Yolanda Valcárcel

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The region of Galicia, found in north-western (NW) Spain, is a national and world leader in shellfish, especially mussel production, and recognized for its fishing industry. Few studies have evaluated the presence of emerging contaminants in NW Spain, with those published mainly concerning the continental aquatic environment. The objective of this study was to identify the environmental risk posed by the presence of pharmaceuticals and drugs of abuse in this important coastal region. The presence of sixteen pharmaceuticals (benzodiazepines, anxiolytics, and caffeine), and 19 drugs of abuse (cocainics, amphetamine-like compounds, opiates and opioids, lysergic compounds, and cannabinoids) was assessed in 23 sites located in the Rías (Coastal inlets) of Muros, Arousa, and Pontevedra (NW Spain). Twenty-two of these locations were affected by waste-water treatment plant (WWTP) effluents, and one represented the effluent of one of these WWTPs. Venlafaxine was the pharmaceutical compound detected at higher concentration in the three Rías, with a maximum value of 291 ng/L at the site Porto do Son (Ría de Muros). Total concentration in the three Rías was 819,26 ng/L. Next, citalopram and lorazepam were the most prevalent compounds detected. Metabolite of cocaine benzoylecgonine was the drug of abuse with the highest concentration, measured at 972 ng/L in the Ría of Noia WWTP (no dilution). This compound was also detected at 142 ng/L in the site La Isla de Aros, Ría of Pontevedra. Total concentration for the three Rías was 1210 ng/L. Ephedrine was also detected at high level in the three Rías, with a total concentration of 579,28 ng/L. The results obtained for caffeine show maximum and average concentrations of 857 ng/L Isla de Arosa, Ría de Pontevedra the highest measured in seawater in Spain. A preliminary hazard assessment was carried out by comparing these measured environmental concentrations (MEC) to predicted no-effect concentrations (PNECs) for aquatic organisms. Six out of the 22 seawater samples resulted in a Hazard Quotient (HQ) from chronic exposure higher than 1 with the highest being 17.14, indicating a high probability of adverse effects in the aquatic environment. In addition, the risk was assessed on the basis of persistence, bioaccumulation, and toxicity (PBT). This work was financially supported by the Spanish Ministry of Economy and Competitiveness through the Carlos III Health Institute and the program 'Proyectos de Investigacion en Salud 2015-2017' FIS (PI14/00516), the European Regional Development Fund (ERDF), the Catalan Government (Consolidated Research Groups '2014 SGR 418 - Water and Soil Quality Unit' and 2014 SGR 291 - ICRA), and the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no. 603437. The poster entitled 'Environmental Risk of Pharmaceuticals, Drugs of Abuse and Stimulant Caffeine in Marine Water: A Case Study in the North-Western of Spain'.

Keywords: drug of abuse, pharmaceuticals, caffeine, environmental risk, seawater

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Authors: Crysovaladou Kefaloudi, Kassiani Mellou, Eirini Saranti-Papasaranti, Athanasios Koustenis, Chrysoula Botsi, Agapios Terzidis

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Recent migration crisis led to a vast migrant – refugees movement to Greece which created an urgent need for hosting settlements. Taken into account the protection of public health from possible pathogens related to water and food supply as well as waste and sewage accumulation, a 'Living Conditions Recording Form' was created in the context of 'PHILOS' European Program funded by the Asylum Migration and Integration Fund (AMIF) of EU’s DG Migration and Home Affairs, in order to assess a number of environmental sanitation parameters, in refugees – migrants camps in mainland. The assessment will be completed until the end of July. From March to June 2017, mobile unit teams comprised of health inspectors of sub-action 2 of “PHILOS” proceeded with the assessment of living conditions in twenty-two out of thirty-one camps and 'Stata' was used for the statistical analysis of obtained information. Variables were grouped into the following categories: 1) Camp administration, 2) hosted population number, 3) accommodation, 4) heating installations, 5) personal hygiene, 6) sewage collection and disposal, 7) water supply, 8) waste collection and management, 9) pest control, 10) fire safety, 11) food handling and safety. Preliminary analysis of the results showed that camp administration was performed in 90% of the camps by a public authority with the coordination of various NGOs. The median number of hosted population was 222 ranging from 62 to 3200, and the median value of hosted population per accommodation type was 4 in 19 camps. Heating facilities were provided in 86.1% of camps. In 18.2 % of the camps, one personal hygiene facility was available per 6 people ranging in the rest of the camps from 1 per 3 to 1 per 20 hosted refugees-migrants. Waste and sewage collection was performed depending on populations demand in an adequate way in all recorded camps. In 90% of camps, water was supplied through the central water supply system. In 85% of camps quantity and quality of water supply inside camps was regularly monitored for microbial and chemical indices. Pest control was implemented in 86.4% of the camps as well as fire safety measures. Food was supplied by catering companies in 50% of the camps, and the quality and quantity food was monitored at a regular basis. In 77% of camps, food was prepared by the hosted population with the availability of proper storage conditions. Furthermore, in all camps, hosted population was provided with personal hygiene items and health sanitary educational programs were implemented in 77.3% of camps. In conclusion, in the majority of the camps, environmental sanitation parameters were satisfactory. However, waste and sewage accumulation, as well as inadequate pest control measures were recorded in some camps. The obtained data have led to a number of recommendations for the improvement of sanitary conditions, disseminated to all relevant stakeholders. Special emphasis was given to hygiene measures implementation during food handling by migrants – refugees, as well as to waste and sewage accumulation taking in to account the population’s cultural background.

Keywords: environmental sanitation parameters, food borne diseases risk assessment, refugee – migrants camps, water borne diseases risk assessment

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Authors: Omer Leshem, Michael F. Schober

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This paper introduces a new method for assessing how audience members and performers feel and think during live concerts, and how audience members' recognized and felt emotions are related. Two hypotheses were tested in a live concert setting: (1) that audience members’ cognitive perspective taking ability predicts their accuracy in identifying an emotion that a jazz improviser intended to express during a performance, and (2) that audience members' affective empathy predicts their likelihood of feeling the same emotions as the performer. The aim was to stage a concert with audience members who regularly attend live jazz performances, and to measure their cognitive and affective reactions during the performance as non-intrusively as possible. Pianist and Grammy nominee Andy Milne agreed, without knowing details of the method or hypotheses, to perform a full-length solo improvised concert that would include an ‘unusual’ piece. Jazz fans were recruited through typical advertising for New York City jazz performances. The event was held at the New School’s Glass Box Theater, the home of leading NYC jazz venue ‘The Stone.’ Audience members were charged typical NYC jazz club admission prices; advertisements informed them that anyone who chose to participate in the study would be reimbursed their ticket price after the concert. The concert, held in April 2018, had 30 attendees, 23 of whom participated in the study. Twenty-two minutes into the concert, the performer was handed a paper note with the instruction: ‘Perform a 3-5-minute improvised piece with the intention of conveying sadness.’ (Sadness was chosen based on previous music cognition lab studies, where solo listeners were less likely to select sadness as the musically-expressed emotion accurately from a list of basic emotions, and more likely to misinterpret sadness as tenderness). Then, audience members and the performer were invited to respond to a questionnaire from a first envelope under their seat. Participants used their own words to describe the emotion the performer had intended to express, and then to select the intended emotion from a list. They also reported the emotions they had felt while listening using Izard’s differential emotions scale. The concert then continued as usual. At the end, participants answered demographic questions and Davis’ interpersonal reactivity index (IRI), a 28-item scale designed to assess both cognitive and affective empathy. Hypothesis 1 was supported: audience members with greater cognitive empathy were more likely to accurately identify sadness as the expressed emotion. Moreover, audience members who accurately selected ‘sadness’ reported feeling marginally sadder than people who did not select sadness. Hypotheses 2 was not supported; audience members with greater affective empathy were not more likely to feel the same emotions as the performer. If anything, members with lower cognitive perspective-taking ability had marginally greater emotional overlap with the performer, which makes sense given that these participants were less likely to identify the music as sad, which corresponded with the performer’s actual feelings. Results replicate findings from solo lab studies in a concert setting and demonstrate the viability of exploring empathy and collective cognition in improvised live performance.

Keywords: audience, cognition, collective cognition, emotion, empathy, expressed emotion, felt emotion, improvisation, live performance, recognized emotion

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Authors: Kalliopi Kanaki, Michael Kalogiannakis

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Nowadays, in the digital era, the early acquisition of basic programming skills and knowledge is encouraged, as it facilitates students’ exposure to computational thinking and empowers their creativity, problem-solving skills, and cognitive development. More and more researchers and educators investigate the introduction of computational thinking in K-12 since it is expected to be a fundamental skill for everyone by the middle of the 21st century, just like reading, writing and arithmetic are at the moment. In this paper, a doctoral research in the process is presented, which investigates the infusion of computational thinking into science curriculum in early childhood education. The whole attempt aims to develop young children’s computational thinking by introducing them to the fundamental concepts of object-oriented programming in an enjoyable, yet educational framework. The backbone of the research is the digital environment PhysGramming (an abbreviation of Physical Science Programming), which provides children the opportunity to create their own digital games, turning them from passive consumers to active creators of technology. PhysGramming deploys an innovative hybrid schema of visual and text-based programming techniques, with emphasis on object-orientation. Through PhysGramming, young students are familiarized with basic object-oriented programming concepts, such as classes, objects, and attributes, while, at the same time, get a view of object-oriented programming syntax. Nevertheless, the most noteworthy feature of PhysGramming is that children create their own digital games within the context of physical science courses, in a way that provides familiarization with the basic principles of object-oriented programming and computational thinking, even though no specific reference is made to these principles. Attuned to the ethical guidelines of educational research, interventions were conducted in two classes of second grade. The interventions were designed with respect to the thematic units of the curriculum of physical science courses, as a part of the learning activities of the class. PhysGramming was integrated into the classroom, after short introductory sessions. During the interventions, 6-7 years old children worked in pairs on computers and created their own digital games (group games, matching games, and puzzles). The authors participated in these interventions as observers in order to achieve a realistic evaluation of the proposed educational framework concerning its applicability in the classroom and its educational and pedagogical perspectives. To better examine if the objectives of the research are met, the investigation was focused on six criteria; the educational value of PhysGramming, its engaging and enjoyable characteristics, its child-friendliness, its appropriateness for the purpose that is proposed, its ability to monitor the user’s progress and its individualizing features. In this paper, the functionality of PhysGramming and the philosophy of its integration in the classroom are both described in detail. Information about the implemented interventions and the results obtained is also provided. Finally, several limitations of the research conducted that deserve attention are denoted.

Keywords: computational thinking, early childhood education, object-oriented programming, physical science courses

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Authors: Juliana Chiarini Balbino Fernandes

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This article aims to investigate the Spanish didactic book, entitled ‘El Calculo y La Medida en El Primer Grado de La Escuela Decroly’, written by Dr. O. Decroly and A. Hamaide, published in Madrid, in the year 1934. In addition to analyzing how mathematical knowledge is present in the proposed Centers of Interest. The textbooks, in addition to pedagogical tools, reflect a certain moment in society and allow the analysis of the theoretical-methodological proposal that can be implemented by the teacher. The study proposed here will be carried out by the lens of Cultural History, supported by Roger Chartier (1991) and by the concepts on textbooks, based on Alain Choppin (2004). The textbook selected for this study exposes a program of ideas associated with the method of Centers of Interest and arithmetic is linked to these interests. In the first courses (six to eight years), most centers can be considered to correspond to occasional calls, as they take advantage of events that arise spontaneously to work with observation, measurement, association and expression exercises. The program of ideas associated with Centers of Interest addresses the biological and social aspects of children, as long as they can express their needs for activities and games, satisfying the natural curiosity. Still, the program of associated ideas offers occasions for problems whose data are taken in observation exercises and concrete expressions (manuals, drawings). In the method applied at the school of L'Ermitage, school created by Decroly in Belgium in 1907, observation, is the basis of each center of interest. It offers the chance to compare and measure. To observe is more than to perceive; it is also to establish relations between the graded aspects of the same object, to seek relations between different intensities; is to verify successions, special and temporary relationships; is to make comparisons, to notice differences and similarities in block or datable (analysis), is to establish a bridge between the world and the thought. To make the observation more precise, it is important to compare, measure, and resort to considered objects as natural units of measure. Measurement and calculation are, therefore, quite naturally subject to observation. Thus, it is possible to make the child enter into the interest in the calculation, linking it to the observation. It was observed that the Centers of Interest, according to Decroly, should respond to the concerns and attend to the motivations of the students and the teaching of arithmetical must obey a logical seriation, considering the interest and the experience of the children. The teaching of arithmetical should not be limited to the schedule, it should cover every quantitative aspect that arises in the other disciplines. The feeling of unity is established in observation, association and expression, which coordinate a whole program of cultural activities, concentrating it around a central idea.

Keywords: didactic book, centers of interest, mathematical knowledge, primary education

Procedia PDF Downloads 108

Authors: Walid A. Alkeridy, Arwa Aljasser, Khalid Mohammed Alayed, Saad Alsaad, Amani S. Alqahtani, Claire Ann Lim, Sultan H. Alamri, Doaa Zainhom Mekkawy, Mohammed Al-Sofiani

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Introduction: The history of publicly funded Home Health Care (HHC) service in Saudi Arabia dates back to 1991. The first HC program was launched to provide palliative home care services for patients with terminal cancer. Thereafter, more programs launched across Saudi Arabia most remarkably was launching the national program for HHC by the Ministry Of Health (MOH) in 2008. The national HHC MOH program is mainly providing long-term care home care services for over 40,000 Saudi citizens. The scope of the HHC service program provided by the Saudi MOH is quite diverse, ranging from basic nursing care to specialized care programs, e.g., home peritoneal dialysis, home ventilation, home infusion therapy, etc. Objectives: The primary aim of our study is to report the prevalence of chronic conditions among Saudi people receiving long-term HHC services. Secondary aims include identifying the predictors of mortality among individuals receiving long-term HHC services and studying the association between frailty and poor health outcomes among HHC users. Methods: We conducted a retrospective and cross-sectional data collection from participants receiving HHC services at King Saud University Medical City, Riyadh, Saudi Arabia. Data were collected from electronic health records (EHR), patient charts, and interviewing caregivers from the year 2019 to 2022. We assessed functional performance by Katz's activity of daily living and the Bristol Activity of Daily Living Scale (BADLS). A trained health care provider assessed frailty using the Clinical Frailty Scale (CFS). Mortality was assessed by reviewing the death certificates if patients were hospitalized through discharge status ascertainment from EHR. Results: The mean age for deceased individuals in HHC was 78.3 years. Over twenty percent of individuals receiving HHC services were readmitted to the hospital. The following variables were statistically significant between deceased and alive individuals receiving HHC services; clinical frailty scale, the total number of comorbid conditions, and functional performance based on the KATZ activity of daily living scale and the BADLS. We found that the strongest predictors for mortality were pressure ulcers which had an odds ratio of 3.75 and p-value of < 0.0001, and the clinical frailty scale, which had an odds ratio of 1.69 and p-value of 0.002, using multivariate regression analysis. In conclusion, our study found that pressure ulcers and frailty are the strongest predictors of mortality for individuals receiving home health care services. Moreover, we found a high rate of annual readmission for individuals enrolled in HHC, which requires further analysis to understand the possible contributing factors for the increased rate of hospital readmission and develop strategies to address them. Future studies should focus on designing quality improvement projects aimed at improving the quality of life for individuals receiving HHC services, especially those who have pressure ulcers at the end of life.

Keywords: homecare, Saudi, prevalence, chronic

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Authors: Shanlong Lu, Jiming Jin, Xiaochun Wang

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The Tibetan Plateau has the largest number of inland lakes with the highest elevation on the planet. These massive and large lakes are mostly in natural state and are less affected by human activities. Their shrinking or expansion can truly reflect regional climate and environmental changes and are sensitive indicators of global climate change. However, due to the sparsely populated nature of the plateau and the poor natural conditions, it is difficult to effectively obtain the change data of the lake, which has affected people's understanding of the temporal and spatial processes of lake water changes and their influencing factors. By using the MODIS (Moderate Resolution Imaging Spectroradiometer) MOD09Q1 surface reflectance images as basic data, this study produced the 8-day lake water surface data set of the Tibetan Plateau from 2000 to 2012 at 250 m spatial resolution, with a lake water surface extraction method of combined with lake water surface boundary buffer analyzing and lake by lake segmentation threshold determining. Then based on the dataset, the lake water surface variations and their influencing factors were analyzed, by using 4 typical natural geographical zones of Eastern Qinghai and Qilian, Southern Qinghai, Qiangtang, and Southern Tibet, and the watersheds of the top 10 lakes of Qinghai, Siling Co, Namco, Zhari NamCo, Tangra Yumco, Ngoring, UlanUla, Yamdrok Tso, Har and Gyaring as the analysis units. The accuracy analysis indicate that compared with water surface data of the 134 sample lakes extracted from the 30 m Landsat TM (Thematic Mapper ) images, the average overall accuracy of the lake water surface data set is 91.81% with average commission and omission error of 3.26% and 5.38%; the results also show strong linear (R2=0.9991) correlation with the global MODIS water mask dataset with overall accuracy of 86.30%; and the lake area difference between the Second National Lake Survey and this study is only 4.74%, respectively. This study provides reliable dataset for the lake change research of the plateau in the recent decade. The change trends and influencing factors analysis indicate that the total water surface area of lakes in the plateau showed overall increases, but only lakes with areas larger than 10 km2 had statistically significant increases. Furthermore, lakes with area larger than 100 km2 experienced an abrupt change in 2005. In addition, the annual average precipitation of Southern Tibet and Southern Qinghai experienced significant increasing and decreasing trends, and corresponding abrupt changes in 2004 and 2006, respectively. The annual average temperature of Southern Tibet and Qiangtang showed a significant increasing trend with an abrupt change in 2004. The major reason for the lake water surface variation in Eastern Qinghai and Qilian, Southern Qinghai and Southern Tibet is the changes of precipitation, and that for Qiangtang is the temperature variations.

Keywords: lake water surface variation, MODIS MOD09Q1, remote sensing, Tibetan Plateau

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Authors: Devin Doos, Ashley Hughes, Trang Pham, Paul Barach, Rami Ahmed

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Over 115,000 Health Care Workers (HCWs) have died from COVID-19, and millions have been infected while caring for patients. HCWs have filed thousands of safety complaints surrounding safety concerns due to Personal Protective Equipment (PPE) shortages, which included concerns around inadequate and PPE reuse. Protocols for donning and doffing PPE remain ambiguous, lacking an evidence-base, and often result in wide deviations in practice. PPE donning and doffing protocol deviations commonly result in self-contamination but have not been thoroughly addressed. No evidence-driven protocols provide guidance on protecting HCW during periods of PPE reuse. Objective: The aim of this study was to examine safety-related threats and risks to Health Care Workers (HCWs) due to the reuse of PPE among Emergency Department personnel. Method: We conducted a prospective observational study to examine the risks of reusing PPE. First, ED personnel were asked to don and doff PPE in a simulation lab. Each participant was asked to don and doff PPE five times, according to the maximum reuse recommendation set by the Centers for Disease Control and Prevention (CDC). Each participant was videorecorded; video recordings were reviewed and coded independently by at least 2 of the 3trained coders for safety behaviors and riskiness of actions. A third coder was brought in when the agreement between the 2 coders could not be reached. Agreement between coders was high (81.9%), and all disagreements (100%) were resolved via consensus. A bowtie risk assessment chart was constructed analyzing the factors that contribute to increased risks HCW are faced with due to PPE use and reuse. Agreement amongst content experts in the field of Emergency Medicine, Human Factors, and Anesthesiology was used to select aspects of health care that both contribute and mitigate risks associated with PPE reuse. Findings: Twenty-eight clinician participants completed five rounds of donning/doffing PPE, yielding 140 PPE donning/doffing sequences. Two emerging threats were associated with behaviors in donning, doffing, and re-using PPE: (i) direct exposure to contaminant, and (ii) transmission/spread of contaminant. Protective behaviors included: hand hygiene, not touching the patient-facing surface of PPE, and ensuring a proper fit and closure of all PPE materials. 100% of participants (n= 28) deviated from the CDC recommended order, and most participants (92.85%, n=26) self-contaminated at least once during reuse. Other frequent errors included failure to tie all ties on the PPE (92.85%, n=26) and failure to wash hands after a contamination event occurred (39.28%, n=11). Conclusions: There is wide variation and regular errors in how HCW don and doffPPE while including in reusing PPE that led to self-contamination. Some errors were deemed “recoverable”, such as hand washing after touching a patient-facing surface to remove the contaminant. Other errors, such as using a contaminated mask and accidentally spreading to the neck and face, can lead to compound risks that are unique to repeated PPE use. A more comprehensive understanding of the contributing threats to HCW safety and complete approach to mitigating underlying risks, including visualizing with risk management toolsmay, aid future PPE designand workflow and space solutions.

Keywords: bowtie analysis, health care, PPE reuse, risk management

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Authors: Rajkumar Ghosh

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Fluoride contamination is a growing concern in various regions across the globe, including North 24 Parganas in West Bengal, India. The presence of excessive fluoride in the environment can have detrimental effects on crops, soil quality, and water resources. This note aims to shed light on the implications of fluoride contamination and its impact on the agricultural sector in North 24 Parganas. The agricultural lands in North 24 Parganas have been significantly affected by fluoride contamination, leading to adverse consequences for crop production. Excessive fluoride uptake by plants can hinder their growth, reduce crop yields, and impact the quality of agricultural produce. Certain crops, such as paddy, vegetables, and fruits, are more susceptible to fluoride toxicity, resulting in stunted growth, leaf discoloration, and reduced nutritional value. Fluoride-contaminated water, often used for irrigation, contributes to the accumulation of fluoride in the soil. Over time, this can lead to soil degradation and reduced fertility. High fluoride levels can alter soil pH, disrupt the availability of essential nutrients, and impair microbial activity critical for nutrient cycling. Consequently, the overall health and productivity of the soil are compromised, making it increasingly challenging for farmers to sustain agricultural practices. Fluoride contamination in North 24 Parganas extends beyond the soil and affects water resources as well. The excess fluoride seeps into groundwater, making it unsafe for consumption. Long-term consumption of fluoride-contaminated water can lead to various health issues, including dental and skeletal fluorosis. These health concerns pose significant risks to the local population, especially those reliant on contaminated water sources for their daily needs. Addressing fluoride contamination requires concerted efforts from various stakeholders, including government authorities, researchers, and farmers. Implementing appropriate water treatment technologies, such as defluoridation units, can help reduce fluoride levels in drinking water sources. Additionally, promoting alternative irrigation methods and crop diversification strategies can aid in mitigating the impact of fluoride on agricultural productivity. Furthermore, creating awareness among farmers about the adverse effects of fluoride contamination and providing access to alternative water sources are crucial steps toward safeguarding the health of the community and sustaining agricultural activities in the region. Fluoride contamination poses significant challenges to crop production, soil health, and water resources in North 24 Parganas, West Bengal. It is imperative to prioritize efforts to address this issue effectively and implement appropriate measures to mitigate fluoride contamination. By adopting sustainable practices and promoting awareness, the community can work towards restoring the agricultural productivity, soil quality and ensuring access to safe drinking water in the region.

Keywords: fluoride contamination, drinking water, toxicity, soil health

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Authors: Eyob Seife

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Immunization is a life-saving intervention which prevents needless suffering through sickness, disability, and death. Emphasis on data quality and use will become even stronger with the development of the immunization agenda 2030 (IA2030). Quality of data is a key factor in generating reliable health information that enables monitoring progress, financial planning, vaccine forecasting capacities, and making decisions for continuous improvement of the national immunization program. However, ensuring data of sufficient quality and promoting an information-use culture at the point of the collection remains critical and challenging, especially in hard-to-reach and pastoralist areas where Degehabur district is selected based on a hypothesis of ‘there is no difference in reported and recounted immunization data consistency. Data quality is dependent on different factors where organizational, behavioral, technical, and contextual factors are the mentioned ones. A cross-sectional quantitative study was conducted on September 2022 in the Degehabur district. The study used the world health organization (WHO) recommended data quality self-assessment (DQS) tools. Immunization tally sheets, registers, and reporting documents were reviewed at 5 health facilities (2 health centers and 3 health posts) of primary health care units for one fiscal year (12 months) to determine the accuracy ratio. The data was collected by trained DQS assessors to explore the quality of monitoring systems at health posts, health centers, and the district health office. A quality index (QI) was assessed, and the accuracy ratio formulated were: the first and third doses of pentavalent vaccines, fully immunized (FI), and the first dose of measles-containing vaccines (MCV). In this study, facility-level results showed both over-reporting and under-reporting were observed at health posts when computing the accuracy ratio of the tally sheet to health post reports found at health centers for almost all antigens verified where pentavalent 1 was 88.3%, 60.4%, and 125.6% for Health posts A, B, and C respectively. For first-dose measles-containing vaccines (MCV), similarly, the accuracy ratio was found to be 126.6%, 42.6%, and 140.9% for Health posts A, B, and C, respectively. The accuracy ratio for fully immunized children also showed 0% for health posts A and B and 100% for health post-C. A relatively better accuracy ratio was seen at health centers where the first pentavalent dose was 97.4% and 103.3% for health centers A and B, while a first dose of measles-containing vaccines (MCV) was 89.2% and 100.9% for health centers A and B, respectively. A quality index (QI) of all facilities also showed results between the maximum of 33.33% and a minimum of 0%. Most of the verified immunization data accuracy ratios were found to be relatively better at the health center level. However, the quality of the monitoring system is poor at all levels, besides poor data accuracy at all health posts. So attention should be given to improving the capacity of staff and quality of monitoring system components, namely recording, reporting, archiving, data analysis, and using information for decision at all levels, especially in pastoralist areas where such kinds of study findings need to be improved beside to improving the data quality at root and health posts level.

Keywords: accuracy ratio, Degehabur District, regular childhood immunization program, quality of monitoring system, Somali Region-Ethiopia

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Authors: Zia Ul Haq, Saleem Muhammad, Naeem Ullah, Abbas Shah, Abdullah Shah

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Pakistan being the developing country is facing double burden of communicable and non-communicable disease. The aspect of secondary prevention of ischemic heart disease in developing countries is the dire need for public health specialists, clinicians and policy makers. There is some evidence that psychotherapeutic measures, including psychotherapy, recreation, exercise and stress management training have positive impact on secondary prevention of cardiovascular diseases but there are some contradictory findings as well. Cardiac rehabilitation program (CRP) has not yet fully implemented in Pakistan. Psychological, physical and specific health-related quality of life (HRQoL) outcomes needs assessment with respect to its practicality, effectiveness, and success. Objectives: To determine the effect of cardiac rehabilitation program (CRP) on the health-related quality of life (HRQoL) measures of post MI patients compared to the usual care. Hypothesis: Post MI patients who receive the interventions (CRP) will have better HRQoL as compared to those who receive the usual cares. Methods: The randomized control trial was conducted at a Cardiac Rehabilitation Unit of Lady Reading Hospital (LRH), Peshawar. LRH is the biggest hospital of the Province Khyber Pakhtunkhwa (KP). A total 206 participants who had recent first myocardial infarction were inducted in the study. Participants were randomly allocated into two group i.e. usual care group (UCG) and cardiac rehabilitation group (CRG) by permuted-block randomization (PBR) method. CRP was conducted in CRG in two phases. Three HRQoL outcomes i.e. general health questionnaire (GHQ), self-rated health (SRH) and MacNew quality of life after myocardial infarction (MacNew QLMI) were assessed at baseline and follow-up visits among both groups. Data were entered and analyzed by appropriate statistical test in STATA version 12. Results: A total of 195 participants were assessed at the follow-up period due to lost-to-follow-up. The mean age of the participants was 53.66 + 8.3 years. Males were dominant in both groups i.e. 150 (76.92%). Regarding educational status, majority of the participants were illiterate in both groups i.e. 128 (65.64%). Surprisingly, there were 139 (71.28%) who were non-smoker on the whole. The comorbid status was positive in 120 (61.54%) among all the patients. The SRH at follow-up among UCG and CRG was 4.06 (95% CI: 3.93, 4.19) and 2.36 (95% CI: 2.2, 2.52) respectively (p<0.001). GHQ at the follow-up of UCG and CRG was 20.91 (95% CI: 18.83, 21.97) and 7.43 (95% CI: 6.59, 8.27) respectively (p<0.001). The MacNew QLMI at follow-up of UCG and CRG was 3.82 (95% CI: 3.7, 3.94) and 5.62 (95% CI: 5.5, 5.74) respectively (p<0.001). All the HRQoL measures showed strongly significant improvement in the CRG at follow-up period. Conclusion: HRQOL improved in post MI patients after comprehensive CRP. Education of the patients and their supervision is needed when they are involved in their rehabilitation activities. It is concluded that establishing CRP in cardiac units, recruiting post-discharged MI patients and offering them CRP does not impose high costs and can result in significant improvement in HRQoL measures. Trial registration no: ACTRN12617000832370

Keywords: cardiovascular diseases, cardiac rehabilitation, health-related quality of life, HRQoL, myocardial infarction, quality of life, QoL, rehabilitation, randomized control trial

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Authors: Ekin Esen, Mohammad Alipour, Riza Kizilel

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Rechargeable lithium-ion batteries have been replacing lead-acid batteries for the last decade due to their outstanding properties such as high energy density, long shelf life, and almost no memory effect. Besides these, being very light compared to lead acid batteries has gained them their dominant place in the portable electronics market, and they are now the leading candidate for electric vehicles (EVs) and hybrid electric vehicles (HEVs). However, their performance strongly depends on temperature, and this causes some inconveniences for their utilization in extreme temperatures. Since weather conditions vary across the globe, this situation limits their utilization for EVs and HEVs and makes a thermal management system obligatory for the battery units. The objective of this study is to understand thermal characteristics of Li-ion battery modules for various operation conditions and design a thermal management system to enhance battery performance in EVs and HEVs. In the first part of our study, we investigated thermal behavior of commercially available pouch type 20Ah LiFePO₄ (LFP) cells under various conditions. Main parameters were chosen as ambient temperature and discharge current rate. Each cell was charged and discharged at temperatures of 0°C, 10°C, 20°C, 30°C, 40°C, and 50°C. The current rate of charging process was 1C while it was 1C, 2C, 3C, 4C, and 5C for discharge process. Temperatures of 7 different points on the cells were measured throughout charging and discharging with N-type thermocouples, and a detailed temperature profile was obtained. In the second part of our study, we connected 4 cells in series by clinching and prepared 4S1P battery modules similar to ones in EVs and HEVs. Three reference points were determined according to the findings of the first part of the study, and a thermocouple is placed on each reference point on the cells composing the 4S1P battery modules. In the end, temperatures of 6 points in the module and 3 points on the top surface were measured and changes in the surface temperatures were recorded for different discharge rates (0.2C, 0.5C, 0.7C, and 1C) at various ambient temperatures (0°C – 50°C). Afterwards, aluminum plates with channels were placed between the cells in the 4S1P battery modules, and temperatures were controlled with airflow. Airflow was provided with a regular compressor, and the effect of flow rate on cell temperature was analyzed. Diameters of the channels were in mm range, and shapes of the channels were determined in order to make the cell temperatures uniform. Results showed that the designed thermal management system could help keeping the cell temperatures in the modules uniform throughout charge and discharge processes. Other than temperature uniformity, the system was also beneficial to keep cell temperature close to the optimum working temperature of Li-ion batteries. It is known that keeping the temperature at an optimum degree and maintaining uniform temperature throughout utilization can help obtaining maximum power from the cells in battery modules for a longer time. Furthermore, it will increase safety by decreasing the risk of thermal runaways. Therefore, the current study is believed to be beneficial for wider use of Li batteries for battery modules of EVs and HEVs globally.

Keywords: lithium ion batteries, thermal management system, electric vehicles, hybrid electric vehicles

Procedia PDF Downloads 165

Authors: Adriana Anselmo Oliveira

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The present project showcases a tile work from the Franco-Portuguese artist Maria Helena Vieira da Silva (1908-1992). It is a set of 8 panels composed of figurative and geometric tiles, with extra tiles framing nearby doors and windows in a study room in the (UFRRJ, Universidade Federal Rural do Rio de Janeiro). The aforementioned work was created between 1942 and 1943, during the artist's 6 year exile in the Brazilian city. This one-of-a-kind tileset was designed and made by Vieira da Silva between 1942 and 1943. Over the years, several units were lost, which led to their replacement in the nineties. However, these replacements don't do justice to the original work of art. In 2007, a project was initiated to fully repair and maintain the set. Three panels are removed and restored, but the project is halted. To this day, the three fully restored panels remain in boxes. In 2016 a new restoration project is submitted by the (Faculdade de Belas Artes da Universidade de Lisboa) in collaboration with de (Fundacão Árpád Szenes-Vieira da Silva). There are many varied opinions on restoring and conserving older pieces of art, however, we have the moral duty to safeguard the original materials used by the artist along with the artists original vision and also to care for the future generations of students who will use the space in which the tile-work was inserted. Many tiles have been replaced by white tiles, tiles with a divergent colour pallet and technique, and in a few cases, the incorrect place or way around. These many factors make it increasingly difficult to maintain the artists original vision and destroy and chance of coherence within the artwork itself. The conservative technician cannot make new images to fill the empty spaces or mark the remaining images with their own creative input. with reliable photographic documentation that can provide us with the necessary vision to allow us to proceed with an accurate reconstruction, we have the obligation to proceed and return the piece of art to its true form, as in its current state, it is impossible to maintain its original glory. Using the information we have, we must find a way to differentiate the original tiles from the reconstructions in order to recreate and reclaim the original message from the artist. The objective of this project is to understand the significance of tiles in Vieira da Silva's art as well as the influence they had on the artist's pictorial language since the colour definition on tile work is vastly different from the painting process as the materials change during their merger. Another primary goal is to understand what the previous interventions achieved besides increasing the artworks durability. The main objective is to submit a proposal that can salvage the artist's visual intention and supports it for posteriority. In summary, this proposal goes further than the usual conservative interventions as it intends to recreate the original artistic worth, prioritising the aesthetics and keeping its soul alive.

Keywords: Vieira da Silva, tiles, conservation, restoration

Procedia PDF Downloads 156

Authors: Angelis P. Barlampas

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Learning Objectives: The purpose of this study is to inform briefly the reader about the applications of AI in chest radiology. Background: Currently, there are 190 FDA-approved radiology AI applications, with 42 (22%) pertaining specifically to thoracic radiology. Imaging findings OR Procedure details Aids of AI in chest radiology1: Detects and segments pulmonary nodules. Subtracts bone to provide an unobstructed view of the underlying lung parenchyma and provides further information on nodule characteristics, such as nodule location, nodule two-dimensional size or three dimensional (3D) volume, change in nodule size over time, attenuation data (i.e., mean, minimum, and/or maximum Hounsfield units [HU]), morphological assessments, or combinations of the above. Reclassifies indeterminate pulmonary nodules into low or high risk with higher accuracy than conventional risk models. Detects pleural effusion . Differentiates tension pneumothorax from nontension pneumothorax. Detects cardiomegaly, calcification, consolidation, mediastinal widening, atelectasis, fibrosis and pneumoperitoneum. Localises automatically vertebrae segments, labels ribs and detects rib fractures. Measures the distance from the tube tip to the carina and localizes both endotracheal tubes and central vascular lines. Detects consolidation and progression of parenchymal diseases such as pulmonary fibrosis or chronic obstructive pulmonary disease (COPD).Can evaluate lobar volumes. Identifies and labels pulmonary bronchi and vasculature and quantifies air-trapping. Offers emphysema evaluation. Provides functional respiratory imaging, whereby high-resolution CT images are post-processed to quantify airflow by lung region and may be used to quantify key biomarkers such as airway resistance, air-trapping, ventilation mapping, lung and lobar volume, and blood vessel and airway volume. Assesses the lung parenchyma by way of density evaluation. Provides percentages of tissues within defined attenuation (HU) ranges besides furnishing automated lung segmentation and lung volume information. Improves image quality for noisy images with built-in denoising function. Detects emphysema, a common condition seen in patients with history of smoking and hyperdense or opacified regions, thereby aiding in the diagnosis of certain pathologies, such as COVID-19 pneumonia. It aids in cardiac segmentation and calcium detection, aorta segmentation and diameter measurements, and vertebral body segmentation and density measurements. Conclusion: The future is yet to come, but AI already is a helpful tool for the daily practice in radiology. It is assumed, that the continuing progression of the computerized systems and the improvements in software algorithms , will redder AI into the second hand of the radiologist.

Keywords: artificial intelligence, chest imaging, nodule detection, automated diagnoses

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Authors: E. A. Abdel-Hakim

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The corn stemborer Sesamia cretica (Lederer), has been viewed in many parts of the world as a major pest of cultivated maize, graminaceous crops and sugarcane. Its life cycle is comprised of two different phases, one is the growth and developmental phase (non-diapause) and the other is diapause phase which takes place at the last larval instar. Several problems associated with the use of conventional insecticides, have strongly demonstrated the need for applying alternative safe compounds. Prominent among the prototypes of such prospective chemicals are the juvenoids; i.e. the insect (JH) mimics. In fact, the hormonal effect on metabolism has long been viewed as a secondary consequence of its direct action on specific energy-requiring biosynthetic mechanisms. Therefore, the present study was undertaken essentially in a rather systematic fashion as a contribution towards clarifying metabolic and energetic changes taking place during non-diapause wandering larvae as regulated by (JH) mimic. For this purpose, we applied two different doses of JH mimic (Ro 11-0111) in a single (standard) dose of 100µg or in a single dose of 20 µg/g bw in1µl acetone topically at the onset of nondiapause wandering larvae (WL). Energetic data were obtained by indirect calorimetry methods by conversion of respiratory gas exchange volumetric data, as measured manometrically using a Warburg constant respirometer, to caloric units (g-cal/g fw/h). The findings obtained can be given in brief; these treated larvae underwent supernumerary larval moults. However, this potential the wandering larvae proved to possess whereby restoration of larval programming for S. cretica to overcome stresses even at this critical developmental period. The results obtained, particularly with the high dose used, show that 98% wandering larvae were rescued to survive up to one month (vs. 5 days for normal controls), finally the formation of larval-adult intermediates. Also, the solvent controls had resulted in about 22% additional, but stationary moultings. The basal respiratory metabolism (O2 uptake and CO2 output) of the (WL), whether un-treated or larvae not had followed reciprocal U-shaped curves all along of their developmental duration. The lowest points stood nearly to the day of prepupal formation (571±187 µl O2/gfw/h and 553±181 µl CO2/gfw/h) during un-treated in contrast to the larvae treated with JH (210±48 µl O2/gfw/h and 335±81 µl CO2/gfw/h). Un-treated (normal) larvae proved to utilize carbohydrates as the principal source for energy supply; being fully oxidised without sparing any appreciable amount for endergonic conversion to fats. While, the juvenoid-treated larvae and compared with the acetone-treated control equivalents, there existed no distinguishable differences between them; both had been observed utilising carbohydrates as the sole source of energy demand and converting endergonically almost similar percentages to fats. The overall profile, treated and un-treated (WL) utilized carbohydrates as the principal source for energy demand during this stage.

Keywords: juvenile hormone, respiratory metabolism, Sesamia cretica, wandering phase

Procedia PDF Downloads 294

Authors: Sebastian Kehne, Alexander Epple, Werner Herfs

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A new method for optimal selection of components for multi-axes forward-feed drive systems is proposed in which the choice of motors, gear boxes and ball screw drives is optimized. Essential is here the synchronization of electrical and mechanical frequency behavior of all axes because even advanced controls (like H∞-controls) can only control a small part of the mechanical modes – namely only those of observable and controllable states whose value can be derived from the positions of extern linear length measurement systems and/or rotary encoders on the motor or gear box shafts. Further problems are the unknown processing forces like cutting forces in machine tools during normal operation which make the estimation and control via an observer even more difficult. To start with, the open source Modelica Feed Drive Library which was developed at the Laboratory for Machine Tools, and Production Engineering (WZL) is extended from one axis design to the multi axes design. It is capable to simulate the mechanical, electrical and thermal behavior of permanent magnet synchronous machines with inverters, different gear boxes and ball screw drives in a mechanical system. To keep the calculation time down analytical equations are used for field and torque producing equivalent circuit, heat dissipation and mechanical torque at the shaft. As a first step, a small machine tool with a working area of 635 x 315 x 420 mm is taken apart, and the mechanical transfer behavior is measured with an impulse hammer and acceleration sensors. With the frequency transfer functions, a mechanical finite element model is built up which is reduced with substructure coupling to a mass-damper system which models the most important modes of the axes. The model is modelled with Modelica Feed Drive Library and validated by further relative measurements between machine table and spindle holder with a piezo actor and acceleration sensors. In a next step, the choice of possible components in motor catalogues is limited by derived analytical formulas which are based on well-known metrics to gain effective power and torque of the components. The simulation in Modelica is run with different permanent magnet synchronous motors, gear boxes and ball screw drives from different suppliers. To speed up the optimization different black-box optimization methods (Surrogate-based, gradient-based and evolutionary) are tested on the case. The objective that was chosen is to minimize the integral of the deviations if a step is given on the position controls of the different axes. Small values are good measures for a high dynamic axes. In each iteration (evaluation of one set of components) the control variables are adjusted automatically to have an overshoot less than 1%. It is obtained that the order of the components in optimization problem has a deep impact on the speed of the black-box optimization. An approach to do efficient black-box optimization for multi-axes design is presented in the last part. The authors would like to thank the German Research Foundation DFG for financial support of the project “Optimierung des mechatronischen Entwurfs von mehrachsigen Antriebssystemen (HE 5386/14-1 | 6954/4-1)” (English: Optimization of the Mechatronic Design of Multi-Axes Drive Systems).

Keywords: ball screw drive design, discrete optimization, forward feed drives, gear box design, linear drives, machine tools, motor design, multi-axes design

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Authors: Martin Arguelles Perez, Woosoon Yim, Alexander Barzilov

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High-fidelity radiation monitoring is an essential component in the enhancement of the situational awareness capabilities of the Department of Energy’s Office of Environmental Management (DOE-EM) personnel. In this paper, multiple units of unmanned aerial vehicles (UAVs) each equipped with a cadmium zinc telluride (CZT) gamma-ray sensor are used for radiation source localization, which can provide vital real-time data for the EM tasks. To achieve this goal, a fully autonomous system of multicopter-based UAV swarm in 3D tetrahedron formation is used for surveying the area of interest and performing radiation source localization. The CZT sensor used in this study is suitable for small-size multicopter UAVs due to its small size and ease of interfacing with the UAV’s onboard electronics for high-resolution gamma spectroscopy enabling the characterization of radiation hazards. The multicopter platform with a fully autonomous flight feature is suitable for low-altitude applications such as radiation contamination sites. The conventional approach uses a single UAV mapping in a predefined waypoint path to predict the relative location and strength of the source, which can be time-consuming for radiation localization tasks. The proposed UAV swarm-based approach can significantly improve its ability to search for and track radiation sources. In this paper, two approaches are developed using (a) 2D planar circular (3 UAVs) and (b) 3D tetrahedron formation (4 UAVs). In both approaches, accurate estimation of the gradient vector is crucial for heading angle calculation. Each UAV carries the CZT sensor; the real-time radiation data are used for the calculation of a bulk heading vector for the swarm to achieve a UAV swarm’s source-seeking behavior. Also, a spinning formation is studied for both cases to improve gradient estimation near a radiation source. In the 3D tetrahedron formation, a UAV located closest to the source is designated as a lead unit to maintain the tetrahedron formation in space. Such a formation demonstrated a collective and coordinated movement for estimating a gradient vector for the radiation source and determining an optimal heading direction of the swarm. The proposed radiation localization technique is studied by computer simulation and validated experimentally in the indoor flight testbed using gamma sources. The technology presented in this paper provides the capability to readily add/replace radiation sensors to the UAV platforms in the field conditions enabling extensive condition measurement and greatly improving situational awareness and event management. Furthermore, the proposed radiation localization approach allows long-term measurements to be efficiently performed at wide areas of interest to prevent disasters and reduce dose risks to people and infrastructure.

Keywords: radiation, unmanned aerial system(UAV), source localization, UAV swarm, tetrahedron formation

Procedia PDF Downloads 101

Authors: Rongrong Liu, Li Wang, Hui Xu, Jianpei Fang, Sixi Liu, Xiaolin Yin, Junbin Liang, Gaohui Yan, Yaoyun Li, Yali Zhou, Xinyu Li, Yue Li, Lei Shi, Yongrong Lai, Junjiu Huang, Xinhua Zhang

Abstract:

Background: Beta-Thalassemia is caused by reduced (β+) or absent (β0) synthesis of the β-globin chains of hemoglobin. Transfusions and oral iron chelation therapy have improved the quality of life for patients with Transfusion-Dependent thalassemia (TDT). Recent advances in genome editing platforms of CRISPR-Cas9 have paved the way for induction of HbF by reactivating expression of γ-chain.Aims: We performed CRISPR-Cas9-mediated genome editing of hematopoietic stem cells to mutate HBG1/HBG2 promoter sequence, thereby representing a naturally occurring HPFH-liked mutation, producing RM-001. Here, we present an initial assessment of safety and efficacy of RM-001 in patients with TDT. Methods: Patients (6–35 y of age) with TDT receiving packed red blood cell (pRBC) transfusions of ≥100 mL/kg/y or ≥10 units/y in the previous 2 y were eligible. CD34+ cells were edited with CRISPR-Cas9 using a guide RNA specific for the binding site of BCL11A on the HBG1/2 promoter. Prior to RM-001 product infusion (day 0), patients received myeloablative conditioning with Busulfan from day-7 to day-4. Patients were monitored for AEs Hb expression.Results: Data cut as of 28 Feb 2024, 16 TDT patients have been treated with RM-001 and followed ≥3 months. 5 of these 16 patients had finished their 24 months follow up. Eleven patients have β0/β0 genotype and five patients have β0/β+ genotype. In addition to β-thalassemia, two patients had α- deletion with the genotype of --/αα. Efficacy:All patients received a single dose intravenous infusion of RM-001 cells. 5 of them had been followed 24 months or longer. All patients achieved transfusion-independent (TI, total Hb continued ≥ 9g/dL) (Figure1). Patients demonstrated sustained and clinically meaningful increases in HbF levels since 4 month post-RM-001 infusion (Figure.2). Total hemoglobin in all patients was stable at 10-12g/dL during the follow-up period. Safety:The adverse events observed after RM-001 infusion were consistent with those that are typical of Busulfan-based myeloablation. The allelic editing analysis at 6-month visit showed that the on-target allelic editing frequency in bone marrow cells was 73.44% (64.65% to 84.6%, n=13).Summary/Conclusion: This interim analysis, in which all the 19 patients age from 7.9 to 25yo met the success criteria for the trial with respect to transfusion independence, showed that autologous HBG1/2 promoter-modified CD34+ HSPCs gene therapy resulted in an adequate amount of HbF as early as 2 months after infusion led to near-normal hemoglobin levels, remained transfusion-free through the reported period without product related SAE. After RM-001 infusion, high levels of HbF proportion and on-target editing in bone marrow cells were maintained. Submitted on behalf of the RM-001 Investigators.

Keywords: thalassemian, genetherapy, CRISPR/Cas9, HbF

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Authors: D. Bianco, A. Sollazzo, M. Barbarino, G. Elia, A. Smoraldi, N. Favaloro

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The activities, described in the present paper, have been conducted in the framework of the HYPROB-New Program, carried out by the Italian Aerospace Research Centre (CIRA) promoted and funded by the Italian Ministry of University and Research (MIUR) in order to improve the National background on rocket engine systems for space applications. The Program has the strategic objective to improve National system and technology capabilities in the field of liquid rocket engines (LRE) for future Space Propulsion Systems applications, with specific regard to LOX/LCH4 technology. The main purpose of the HYPROB program is to design and build a Propulsion Test Facility (HIMP) allowing test activities on Liquid Thrusters. The development of skills in liquid rocket propulsion can only pass through extensive test campaign. Following its mission, CIRA has planned the development of new testing facilities and infrastructures for space propulsion characterized by adequate sizes and instrumentation. The IMP test cell is devoted to testing articles representative of small combustion chambers, fed with oxygen and methane, both in liquid and gaseous phase. This article describes the activities that have been carried out for the evaluation of the acoustic impact, and its consequent mitigation. The impact of the simulated acoustic disturbance has been evaluated, first, using an approximated method based on experimental data by Baumann and Coney, included in “Noise and Vibration Control Engineering” edited by Vér and Beranek. This methodology, used to evaluate the free-field radiation of jet in ideal acoustical medium, analyzes in details the jet noise and assumes sources acting at the same time. It considers as principal radiation sources the jet mixing noise, caused by the turbulent mixing of jet gas and the ambient medium. Empirical models, allowing a direct calculation of the Sound Pressure Level, are commonly used for rocket noise simulation. The model named after K. Eldred is probably one of the most exploited in this area. In this paper, an improvement of the Eldred Standard model has been used for a detailed investigation of the acoustical impact of the Hyprob facility. This new formulation contains an explicit expression for the acoustic pressure of each equivalent noise source, in terms of amplitude and phase, allowing the investigation of the sources correlation effects and their propagation through wave equations. In order to enhance the evaluation of the facility acoustic impact, including an assessment of the mitigation strategies to be set in place, a more advanced simulation campaign has been conducted using both an in-house code for noise propagation and scattering, and a commercial code for industrial noise environmental impact, CadnaA. The noise prediction obtained with the revised Eldred-based model has then been used for formulating an empirical/BEM (Boundary Element Method) hybrid approach allowing the evaluation of the barrier mitigation effect, at the design. This approach has been compared with the analogous empirical/ray-acoustics approach, implemented within CadnaA using a customized definition of sources and directivity factor. The resulting impact evaluation study is reported here, along with the design-level barrier optimization for noise mitigation.

Keywords: acoustic impact, industrial noise, mitigation, rocket noise

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Authors: Jessica P. Fiorotti, Maria C. Freitas, Caio J. B. Coutinho-Rodrigues, Mariana G. Camargo, Emily S. Mesquita, Amanda R. C. Corval, Ricardo O. B. Bitencourt, Allan F. Marciano, Diva D. Spadacci-Morena, Patricia S. Golo, Isabele C. Angelo, Vania R. E. P. Bittencourt

Abstract:

The bovine tick, Rhipicephalus microplus, is an arthropod of great importance in veterinary medicine leading to anemia, weight loss, animals' leather depreciation and also acting as a vector of many pathogens. In this way, the parasitism causes a loss of 3.24 billion dollars per year in Brazil. Knowingly, entomopathogenic fungi act as natural controller of some arthropods, acting mainly by active penetration through the cuticle. However, it can also act on the hemolymph and through the production of mycotoxins. Hemocytes are responsible for the cellular immune response and participate in the processes of phagocytosis, nodulation and encapsulation and may undergo changes when challenged by pathogens. The aim of the present study was to evaluate changes in R. microplus hemocytes after inoculation of Metarhizium robertsii using transmission electron microscopy. The isolate ARSEF 2575 and 200 engorged R. microplus females were used. The groups were divided into control, in which the females were inoculated with 5 μL of sterile distilled water solution and 0.1% Tween 80, and a group inoculated with 5 μL of fungal suspension at the concentration of 10⁷ conidia mL⁻¹. The experiment was performed in duplicate and each group contained 50 females. Twenty-four hours after fungal inoculation, hemolymph was collected through the cuticle dorsal surface perforation of the tick females. After collection, the hemolymph samples were centrifuged at 500 x g for 3 minutes at 4 °C, the plasma was discarded and the hemocyte pellet was resuspended in 50 μl PBS. The suspension material was fixed in 2% glutaraldehyde in Millonig buffer for three hours. After fixation, the material was centrifuged at 500 x g for 3 minutes, the supernatant was discarded and the cells were resuspended in a wash solution. Subsequently, the cells were post-fixed with 1% osmium tetroxide in phosphate buffer for one hour at room temperature and dehydrated in increasing concentrations of ethanol, and then embedded in Epon resin. The ultrathin sections were examined under the LEO EM 906E transmission electron microscopy at 80kV. The ultrastructural results revealed that.in control group, the cells were considered intact, in which the granulocytes were observed with granules of different electrodensities, intact mitochondria and cytoplasm without vacuolization. In addition, granulocytes showed plasma membrane projections similar to pseudopodia. Plasmatocytes presented as irregularly shaped cells, with the eccentric nucleus, agranular cytoplasm and some cells presented pseudopodia. Nevertheless, in the group exposed to the fungus, most of the cells presented in degeneration. The granulocytes found had fewer granules in the cytoplasm and more vacuoles. Plasmatocytes, after treatment, presented many vacuoles also in the cytoplasm and the lysosomes presented great amount of electrodense material in their interior. Thus, the results suggest that the fungus has a depressant action in the immune system of the tick, not only by the cell degranulation, but also suggesting that this leads to morphological changes in the hemocytes and may even trigger processes such as phagocytosis.

Keywords: bovine tick, cellular defense, entomopathogenic fungi, immune response

Procedia PDF Downloads 190

Authors: L. P. Gomes, G. F. Araújo, Y. M. L. Cordeiro, C. T. Andrade, E. M. Del Aguila, V. M. F. Paschoalin

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The application of nanoscale materials and nanostructures is an emerging area, these since materials may provide solutions to technological and environmental challenges in order to preserve the environment and natural resources. To reach this goal, the increasing demand must be accompanied by 'green' synthesis methods. Chitosan is a natural, nontoxic, biopolymer derived by the deacetylation of chitin and has great potential for a wide range of applications in the biological and biomedical areas, due to its biodegradability, biocompatibility, non-toxicity and versatile chemical and physical properties. Chitosan also presents high antimicrobial activities against a wide variety of pathogenic and spoilage microorganisms. Ultrasonication is a common tool for the preparation and processing of polymer nanoparticles. It is particularly effective in breaking up aggregates and in reducing the size and polydispersity of nanoparticles. High-intensity ultrasonication has the potential to modify chitosan molecular weight and, thus, alter or improve chitosan functional properties. The aim of this study was to evaluate the influence of sonication intensity and time on the changes of commercial chitosan characteristics, such as molecular weight and its potential antibacterial activity against Gram-negative bacteria. The nanoparticles (NPs) were produced from two commercial chitosans, of medium molecular weight (CS-MMW) and low molecular weight (CS-LMW) from Sigma-Aldrich®. These samples (2%) were solubilized in 100 mM sodium acetate pH 4.0, placed on ice and irradiated with an ultrasound SONIC ultrasonic probe (model 750 W), equipped with a 1/2" microtip during 30 min at 4°C. It was used on constant duty cycle and 40% amplitude with 1/1s intervals. The ultrasonic degradation of CS-MMW and CS-LMW were followed up by means of ζ-potential (Brookhaven Instruments, model 90Plus) and dynamic light scattering (DLS) measurements. After sonication, the concentrated samples were diluted 100 times and placed in fluorescence quartz cuvettes (Hellma 111-QS, 10 mm light path). The distributions of the colloidal particles were calculated from the DLS and ζ-potential are measurements taken for the CS-MMW and CS-LMW solutions before and after (CS-MMW30 and CS-LMW30) sonication for 30 min. Regarding the results for the chitosan sample, the major bands can be distinguished centered at Radius hydrodynamic (Rh), showed different distributions for CS-MMW (Rh=690.0 nm, ζ=26.52±2.4), CS-LMW (Rh=607.4 and 2805.4 nm, ζ=24.51±1.29), CS-MMW30 (Rh=201.5 and 1064.1 nm, ζ=24.78±2.4) and CS-LMW30 (Rh=492.5, ζ=26.12±0.85). The minimal inhibitory concentration (MIC) was determined using different chitosan samples concentrations. MIC values were determined against to E. coli (106 cells) harvested from an LB medium (Luria-Bertani BD™) after 18h growth at 37 ºC. Subsequently, the cell suspension was serially diluted in saline solution (0.8% NaCl) and plated on solid LB at 37°C for 18 h. Colony-forming units were counted. The samples showed different MICs against E. coli for CS-LMW (1.5mg), CS-MMW30 (1.5 mg/mL) and CS-LMW30 (1.0 mg/mL). The results demonstrate that the production of nanoparticles by modification of their molecular weight by ultrasonication is simple to be performed and dispense acid solvent addition. Molecular weight modifications are enough to provoke changes in the antimicrobial potential of the nanoparticles produced in this way.

Keywords: antimicrobial agent, chitosan, green production, nanoparticles

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Authors: Satish Kumar, Nisha Goyal

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In the stock market, individual investors exhibit different kinds of behaviour. Traditional finance is built on the notion of 'homo economics', which states that humans always make perfectly rational choices to maximize their wealth and minimize risk. That is, traditional finance has concern for how investors should behave rather than how actual investors are behaving. Behavioural finance provides the explanation for this phenomenon. Although finance has been studied for thousands of years, behavioural finance is an emerging field that combines the behavioural or psychological aspects with conventional economic and financial theories to provide explanations on how emotions and cognitive factors influence investors’ behaviours. These emotions and cognitive factors are known as behavioural biases. Because of these biases, investors make irrational investment decisions. Besides, the emotional and cognitive factors, the social influence of media as well as friends, relatives and colleagues also affect investment decisions. Psychological factors influence individual investors’ investment decision making, but few studies have used qualitative methods to understand these factors. The aim of this study is to explore the behavioural factors or biases that affect individuals’ investment decision making. For the purpose of this exploratory study, an in-depth interview method was used because it provides much more exhaustive information and a relaxed atmosphere in which people feel more comfortable to provide information. Twenty investment advisors having a minimum 5 years’ experience in securities firms were interviewed. In this study, thematic content analysis was used to analyse interview transcripts. Thematic content analysis process involves analysis of transcripts, coding and identification of themes from data. Based on the analysis we categorized the statements of advisors into various themes. Past market returns and volatility; preference for safe returns; tendency to believe they are better than others; tendency to divide their money into different accounts/assets; tendency to hold on to loss-making assets; preference to invest in familiar securities; tendency to believe that past events were predictable; tendency to rely on the reference point; tendency to rely on other sources of information; tendency to have regret for making past decisions; tendency to have more sensitivity towards losses than gains; tendency to rely on own skills; tendency to buy rising stocks with the expectation that this rise will continue etc. are some of the major concerns showed by experts about investors. The findings of the study revealed 13 biases such as overconfidence bias, disposition effect, familiarity bias, framing effect, anchoring bias, availability bias, self-attribution bias, representativeness, mental accounting, hindsight bias, regret aversion, loss aversion and herding bias/media biases present in Indian investors. These biases have a negative connotation because they produce a distortion in the calculation of an outcome. These biases are classified under three categories such as cognitive errors, emotional biases and social interaction. The findings of this study may assist both financial service providers and researchers to understand the various psychological biases of individual investors in investment decision making. Additionally, individual investors will also be aware of the behavioural biases that will aid them to make sensible and efficient investment decisions.

Keywords: financial advisors, individual investors, investment decisions, psychological biases, qualitative thematic content analysis

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Authors: Corentin Jankowiak, Aggelos Zacharopoulos, Caterina Brandoni

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In a context of increasing stress put on the electricity network by the decarbonization of many sectors, energy storage is likely to be the key mitigating element, by acting as a buffer between production and demand. In particular, the highest potential for storage is when connected closer to the loads. Yet, low voltage storage struggles to penetrate the market at a large scale due to the novelty and complexity of the solution, and the competitive advantage of fossil fuel-based technologies regarding regulations. Strong and reliable numerical simulations are required to show the benefits of storage located near loads and promote its development. The present study was restrained from excluding aggregated control of storage: it is assumed that the storage units operate independently to one another without exchanging information – as is currently mostly the case. A computationally light battery model is presented in detail and validated by direct comparison with a domestic battery operating in real conditions. This model is then used to develop Peak-Shaving (PS) control strategies as it is the decentralized service from which beneficial impacts are most likely to emerge. The aggregation of flatter, peak- shaved consumption profiles is likely to lead to flatter and arbitraged profile at higher voltage layers. Furthermore, voltage fluctuations can be expected to decrease if spikes of individual consumption are reduced. The crucial part to achieve PS lies in the charging pattern: peaks depend on the switching on and off of appliances in the dwelling by the occupants and are therefore impossible to predict accurately. A performant PS strategy must, therefore, include a smart charge recovery algorithm that can ensure enough energy is present in the battery in case it is needed without generating new peaks by charging the unit. Three categories of PS algorithms are introduced in detail. First, using a constant threshold or power rate for charge recovery, followed by algorithms using the State Of Charge (SOC) as a decision variable. Finally, using a load forecast – of which the impact of the accuracy is discussed – to generate PS. A performance metrics was defined in order to quantitatively evaluate their operating regarding peak reduction, total energy consumption, and self-consumption of domestic photovoltaic generation. The algorithms were tested on load profiles with a 1-minute granularity over a 1-year period, and their performance was assessed regarding these metrics. The results show that constant charging threshold or power are far from optimal: a certain value is not likely to fit the variability of a residential profile. As could be expected, forecast-based algorithms show the highest performance. However, these depend on the accuracy of the forecast. On the other hand, SOC based algorithms also present satisfying performance, making them a strong alternative when the reliable forecast is not available.

Keywords: decentralised control, domestic integrated batteries, electricity network performance, peak-shaving algorithm

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Authors: Sandra Arango-Caro, Kristine Callis-Duehl

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The Education Research and Outreach Lab at the Donald Danforth Plant Science Center established the Plant and Agriculture Augmented and Virtual Reality Learning Laboratory (PAVRLL) to promote science education through professional development, school programs, internships, and outreach events. Professional development is offered to high school and college science and agriculture educators on the use and applications of zSpace and Oculus platforms. Educators learn to use, edit, or create lesson plans in the zSpace platform that are aligned with the Next Generation Science Standards. They also learn to use virtual reality experiences created by the PAVRLL available in Oculus (e.g. The Soybean Saga). Using a cost-free loan rotation system, educators can bring the AVR units to the classroom and offer AVR activities to their students. Each activity has user guides and activity protocols for both teachers and students. The PAVRLL also offers activities for 3D plant modeling. High school students work in teams of art-, science-, and technology-oriented students to design and create 3D models of plant species that are under research at the Danforth Center and present their projects at scientific events. Those 3D models are open access through the zSpace platform and are used by PAVRLL for professional development and the creation of VR activities. Both teachers and students acquire knowledge of plant and agriculture content and real-world problems, gain skills in AVR technology, 3D modeling, and science communication, and become more aware and interested in plant science. Students that participate in the PAVRLL activities complete pre- and post-surveys and reflection questions that evaluate interests in STEM and STEM careers, students’ perceptions of three design features of biology lab courses (collaboration, discovery/relevance, and iteration/productive failure), plant awareness, and engagement and learning in AVR environments. The PAVRLL was established in the fall of 2019, and since then, it has trained 15 educators, three of which will implement the AVR programs in the fall of 2021. Seven students have worked in the 3D plant modeling activity through a virtual internship. Due to the COVID-19 pandemic, the number of teachers trained, and classroom implementations have been very limited. It is expected that in the fall of 2021, students will come back to the schools in person, and by the spring of 2022, the PAVRLL activities will be fully implemented. This will allow the collection of enough data on student assessments that will provide insights on benefits and best practices for the use of AVR technologies in the classrooms. The PAVRLL uses cutting-edge educational technologies to promote science education and assess their benefits and will continue its expansion. Currently, the PAVRLL is applying for grants to create its own virtual labs where students can experience authentic research experiences using real Danforth research data based on programs the Education Lab already used in classrooms.

Keywords: assessment, augmented reality, education, plant science, virtual reality

Procedia PDF Downloads 174

Authors: Prem Kumar, Anuj Tyagi, Harsh Panwar, Vaneet Inder Kaur

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Though aquaculture started as an occupation for poor and weak farmers for livelihood, it has now acquired the shape of one of the biggest industry to grow live protein in the form of aquatic organisms. Industrialization of the aquaculture sector has led to intensification resulting in stress on aquatic organisms and frequent disease outbreaks leading to huge economic impacts. Indiscriminate use of antibiotics as growth promoter and prophylactic agent in aquaculture has resulted in rapid emergence and spread of antibiotic resistance in bacterial pathogens. Over the past few years, use of probiotics (as an alternative of antibiotics) in aquaculture has gained attention due to their immunostimulant and growth promoting properties. It has now well known that after administration, a probiotic bacterium has to compete and establish itself against native microbiota to show its eventual beneficial properties. Due to their non-fish origin, commercial probiotics sometimes may display poor probiotic functionalities and antagonistic effects. Thus, isolation and characterization of probiotic bacteria from same fish host is very much necessary. In this study, attempts were made to isolate potent probiotic lactic acid bacteria (LAB) from intestinal microflora of rohu fish. Twenty-five experimental rohu fishes (mean weight 400 ± 20gm, mean standard length 20 ± 3cm) were used in the study to collect fish gut after dissection in a sterile condition. A total of 150 tentative LAB isolates from selective agar media (de Man-Rogosa-Sharpe (MRS)) were screened for their antimicrobial activity against Aeromonas hydrophila and Microccocus leuteus. A total of 17 isolates, identified as Lactobacillus plantarum and Lactococcus lactis, identified by biochemical tests and PCR amplification and sequencing of 16S rRNA gene fragment, displayed promising antimicrobial activity against both the pathogens. Two isolates from each species (FLB1, FLB2 from L. plantarum; and FLC1, FLC2 from L. lactis) were subjected to downstream probiotic potential characterization. These isolates were compared in vitro for their hemolytic activity, acid and bile tolerance for growth kinetics, auto-aggregation, cell-surface hydrophobicity against xylene, and chloroform, tolerance to phenol, cell adhesion, and safety parameters (by intraperitoneal and intramuscular injections). None of the tested isolates showed any hemolytic activity indicating their potential safety. Moreover, these isolates were tolerant to 0.3% bile (75-82% survival), phenol stress (96-99% survival) with 100% viability at pH 3 over a period of 3 h. Antibiotic sensitivity test revealed that all the tested LAB isolates were resistant to vancomycin, gentamicin, streptomycin, and erythromycin and sensitive to Erythromycin, Chloramphenicol, Ampicillin, Trimethoprim, and Nitrofurantoin. Tetracycline resistance was found in L. plantarum (FLB1 and FLB2 isolates), whereas L. lactis were susceptible to it. Intramuscular and intraperitoneal challenges to fingerlings of rohu fish (5 ± 1gm weight) with FLB1 showed no pathogenicity and occurrence of disease symptoms in fishes over an observation period of 7 days. The results revealed FLB1 as a potential probiotic candidate for aquaculture application among other isolates.

Keywords: aquaculture, Lactobacillus plantarum, Lactococcus lactis, probiotics

Procedia PDF Downloads 137

Authors: Fernando Vega, Esmeralda Portillo, Sara Camino, Benito Navarrete, Elena Montavez

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The European Union aims at strongly reducing their CO₂ emissions from energy and industrial sector by 2030. The energy sector contributes with more than two-thirds of the CO₂ emission share derived from anthropogenic activities. Although efforts are mainly focused on the use of renewables by energy production sector, carbon capture and storage (CCS) remains as a frontline option to reduce CO₂ emissions from industrial process, particularly from fossil-fuel power plants and cement production. Among the most feasible and near-to-market CCS technologies, namely post-combustion and oxy-combustion, partial oxy-combustion is a novel concept that can potentially reduce the overall energy requirements of the CO₂ capture process. This technology consists in the use of higher oxygen content in the oxidizer that should increase the CO₂ concentration of the flue gas once the fuel is burnt. The CO₂ is then separated from the flue gas downstream by means of a conventional CO₂ chemical absorption process. The production of a higher CO₂ concentrated flue gas should enhance the CO₂ absorption into the solvent, leading to further reductions of the CO₂ separation performance in terms of solvent flow-rate, equipment size, and energy penalty related to the solvent regeneration. This work evaluates a portfolio of CCS technologies applied to fossil-fuel power plants. For this purpose, an economic evaluation methodology was developed in detail to determine the main economical parameters for CO₂ emission removal such as the levelized cost of electricity (LCOE) and the CO₂ captured and avoided costs. ASPEN Plus™ software was used to simulate the main units of power plant and solve the energy and mass balance. Capital and investment costs were determined from the purchased cost of equipment, also engineering costs and project and process contingencies. The annual capital cost and operating and maintenance costs were later obtained. A complete energy balance was performed to determine the net power produced in each case. The baseline case consists of a supercritical 500 MWe coal-fired power plant using anthracite as a fuel without any CO₂ capture system. Four cases were proposed: conventional post-combustion capture, oxy-combustion and partial oxy-combustion using two levels of oxygen-enriched air (40%v/v and 75%v/v). CO₂ chemical absorption process using monoethanolamine (MEA) was used as a CO₂ separation process whereas the O₂ requirement was achieved using a conventional air separation unit (ASU) based on Linde's cryogenic process. Results showed a reduction of 15% of the total investment cost of the CO₂ separation process when partial oxy-combustion was used. Oxygen-enriched air production also reduced almost half the investment costs required for ASU in comparison with oxy-combustion cases. Partial oxy-combustion has a significant impact on the performance of both CO₂ separation and O₂ production technologies, and it can lead to further energy reductions using new developments on both CO₂ and O₂ separation processes.

Keywords: carbon capture, cost methodology, economic evaluation, partial oxy-combustion

Procedia PDF Downloads 149

Authors: Carlos Amnael Orozco-Diaz, Robert David Moorehead, Gwendolen Reilly, Fiona Gilchrist, Cheryl Ann Miller

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The current gold-standard for maxillofacial reconstruction surgery (MRS) utilizes auto-grafted cancellous bone as a filler. This study was aimed towards developing a polylactic-acid/hydroxyapatite (PLA-HA) composite suitable for fused-deposition 3D printing. Functionalization of the polymer through the addition of HA was directed to promoting bone-regeneration properties so that the material can rival the performance of cancellous bone grafts in terms of bone-lesion repair. This kind of composite enables the production of MRS implants based off 3D-reconstructions from image studies – namely computed tomography – for anatomically-correct fitting. The present study encompassed in-vitro degradation and in-vitro biocompatibility profiling for 3D-printed PLA and PLA-HA composites. PLA filament (Verbatim Co.) and Captal S hydroxyapatite micro-scale HA powder (Plasma Biotal Ltd) were used to produce PLA-HA composites at 5, 10, and 20%-by-weight HA concentration. These were extruded into 3D-printing filament, and processed in a BFB-3000 3D-Printer (3D Systems Co.) into tensile specimens, and were mechanically challenged as per ASTM D638-03. Furthermore, tensile specimens were subjected to accelerated degradation in phosphate-buffered saline solution at 70°C for 23 days, as per ISO-10993-13-2010. This included monitoring of mass loss (through dry-weighing), crystallinity (through thermogravimetric analysis/differential thermal analysis), molecular weight (through gel-permeation chromatography), and tensile strength. In-vitro biocompatibility analysis included cell-viability and extracellular matrix deposition, which were performed both on flat surfaces and on 3D-constructs – both produced through 3D-printing. Discs of 1 cm in diameter and cubic 3D-meshes of 1 cm3 were 3D printed in PLA and PLA-HA composites (n = 6). The samples were seeded with 5000 MG-63 osteosarcoma-like cells, with cell viability extrapolated throughout 21 days via resazurin reduction assays. As evidence of osteogenicity, collagen and calcium deposition were indirectly estimated through Sirius Red staining and Alizarin Red staining respectively. Results have shown that 3D printed PLA loses structural integrity as early as the first day of accelerated degradation, which was significantly faster than the literature suggests. This was reflected in the loss of tensile strength down to untestable brittleness. During degradation, mass loss, molecular weight, and crystallinity behaved similarly to results found in similar studies for PLA. All composite versions and pure PLA were found to perform equivalent to tissue-culture plastic (TCP) in supporting the seeded-cell population. Significant differences (p = 0.05) were found on collagen deposition for higher HA concentrations, with composite samples performing better than pure PLA and TCP. Additionally, per-cell-calcium deposition on the 3D-meshes was significantly lower when comparing 3D-meshes to discs of the same material (p = 0.05). These results support the idea that 3D-printable PLA-HA composites are a viable resorbable material for artificial grafts for bone-regeneration. Degradation data suggests that 3D-printing of these materials – as opposed to other manufacturing methods – might result in faster resorption than currently-used PLA implants.

Keywords: bone regeneration implants, 3D-printing, in vitro testing, biocompatibility, polymer degradation, polymer-ceramic composites

Procedia PDF Downloads 155

Authors: Anita Conti, Riccardo Ossanna, Lindsey A. Quintero, Giamaica Conti, Andrea Sbarbati

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Ischemia/reperfusion (IR) injury induces muscle fiber atrophy and skeletal muscle fiber death with subsequently functionality loss. The heterogeneous pool of cells, especially mesenchymal stem cells, contained in the stromal vascular fraction (SVF) of adipose tissue could promote muscle fiber regeneration. To prevent SVF dispersion, it has been proposed the use of injectable biopolymers that work as cells carrier. A significant element of the extracellular matrix is hyaluronic acid (HA), which has been widely used in regenerative medicine as a cell scaffold given its biocompatibility, degradability, and the possibility of chemical functionalization. Connective tissue micro-fragments enriched with SVF obtained from mechanical disaggregation of adipose tissue were evaluated for IR muscle injury regeneration using low molecular weight HA as a scaffold. IR induction. Hindlimb ischemia was induced in 9 athymic nude mice through the clamping of the right quadriceps using a plastic band. Reperfusion was induced by cutting the plastic band after 3 hours of ischemic period. Contralateral (left) muscular tissue was used as healthy control. Treatment. Twenty-four hours after the IR induction, animals (n=3) were intramuscularly injected with 100 µl of SVF mixed with HA (SVF-HA). Animals treated with 100 µl of HA (n=3) and 100 µl saline solution (n=3) were used as control. Treatment monitoring. All animals were in vivo monitored by magnetic resonance imaging (MRI) at 5, 7, 14 and 18 days post-injury (dpi). High-resolution morphological T2 weighed, quantitative T2 map and Dynamic Contrast-Enhanced (DCE) images were acquired in order to assess the regenerative potential of SVF-HA treatment. Ex vivo evaluation. After 18 days from IR induction, animals were sacrificed, and the muscles were harvested for histological examination. At 5 dpi T2 high-resolution MR images clearly reveal the presence of an extensive edematous area due to IR damage for all groups identifiable as an increase of signal intensity (SI) of muscular and surrounding tissue. At 7 dpi, animals of the SVF-HA group showed a reduction of SI, and the T2relaxation time of muscle tissue of the HA-SVF group was 29±0.5ms, comparable with the T2relaxation time of contralateral muscular tissue (30±0.7ms). These suggest a reduction of edematous overflow and swelling. The T2relaxation time at 7dpi of HA and saline groups were 84±2ms and 90±5ms, respectively, which remained elevated during the rest of the study. The evaluation of vascular regeneration showed similar results. Indeed, DCE-MRI analysis revealed a complete recovery of muscular tissue perfusion after 14 dpi for the SVF-HA group, while for the saline and HA group, controls remained in a damaged state. Finally, the histological examination of SVF-HA treated animals exhibited well-defined and organized fibers morphology with a lateralized nucleus, similar to contralateral healthy muscular tissue. On the contrary, HA and saline-treated animals presented inflammatory infiltrates, with HA slightly improving the diameter of the fibers and less degenerated tissue. Our findings show that connective tissue micro-fragments enriched with SVF induce higher muscle homeostasis and perfusion restoration in contrast to control groups.

Keywords: ischemia/reperfusion injury, regenerative medicine, resonance imaging, stromal vascular fraction

Procedia PDF Downloads 128