bluuebunny/crossref_metadata_2025 huggingface dataset:
Stakeholders’ interactions in managing water resources conflicts: a case of Lake Naivasha, Kenya
Authors: Renner Julia , Opiyo Francis
Published: April 2021

Recent years have seen unprecedented pressure from numerous water stakeholders with different interests in Lake Naivasha basin, the only freshwater lake in the Great Rift Valley of Kenya. The pressure on this water resource results in high competition over access to water source, unsustainable resources management practices, poor water quality, and emergence of conflicts between institutions and its users. Presently, there is a knowledge gap and paucity of information on water resources stakeholders’ interactions in Lake Naivasha basin. This study, therefore, analyses the ways resource stakeholders interact and play in the conflict dynamic, and ultimately propose a better water resource use and management approaches. Drawing on field assessments, individual interviews, focus group discussion, and secondary literature reviews, this paper illustrates how both local, national and multi-national stakeholders interact and contribute to water resources conflicts. Results suggest unclear county and national institutional structures, fragmented land use activities and ownership, a feeling of marginalization by the local population contributing to resource-based conflict within the lake basin. A comprehensive policy framework and enforcement of existing regulations will ensure there is sustainable water access, reduce conflicts and enhance sustainable water resource governance and use of the lake.
Na2La4(NH2)14·NH3, a lanthanum-rich intermediate in the ammonothermal synthesis of LaN and the effect of ammonia loss on the crystal structure
Authors: Kunkel Sebastian , Niewa Rainer
Published: April 2021

Single crystals of Na2La4(NH2)14·NH3 were obtained from supercritical ammonia under ammonobasic conditions at a temperature of 573 K and 120 MPa pressure. It represents a lanthanum-rich intermediate in the ammonothermal synthesis of LaN. Upon aging, the title compound loses the crystal ammonia, resulting in pale crystals of Na2La4(NH2)14, the original space group P212121 being retained in a very similar unit cell. However, the crystal structure reacts to subtle changes in the composition as well as to the modified coordination of particularly the sodium cations interconnecting lanthanum amide layers within a third dimension. Results of Raman spectroscopic studies are reported. The observations of thermal analysis measurements indicating the formation of lanthanum nitride, in combination with the observed retrograde solubility in liquid ammonia, contribute to the knowledge of the ammonothermal crystal growth of lanthanum nitride.
The mustatils: cult and monumentality in Neolithic north-western Arabia
Authors: Thomas Hugh , Kennedy Melissa A. , Dalton Matthew , McMahon Jane , Boyer David , Repper Rebecca
Published: April 2021

North-western Arabia is marked by thousands of prehistoric stone structures. Of these, the monumental, rectilinear type known as mustatils has received only limited attention. Recent fieldwork in AlUla and Khaybar Counties, Saudi Arabia, demonstrates that these monuments are architecturally more complex than previously supposed, featuring chambers, entranceways and orthostats. These structures can now be interpreted as ritual installations dating back to the late sixth millennium BC, with recent excavations revealing the earliest evidence for a cattle cult in the Arabian Peninsula. As such, mustatils are amongst the earliest stone monuments in Arabia and globally one of the oldest monumental building traditions yet identified.
Horizontal Force-Velocity-Power Profiling of Rugby Players: A Cross-Sectional Analysis of Competition-Level and Position-Specific Movement Demands
Authors: Watkins Casey M. , Storey Adam , McGuigan Michael R. , Downes Paul , Gill Nicholas D.
Published: April 2021

Watkins, CM, Storey, A, McGuigan, MR, Downes, P, and Gill, ND. Horizontal force-velocity-power profiling of rugby players: A cross-sectional analysis of competition-level and position-specific movement demands. J Strength Cond Res 35(6): 1576–1585, 2021—Speed and acceleration are crucial to competitive success in all levels of rugby union. However, positional demands affect an athlete's expression of force and velocity during the match. This study investigated maximal sprint performance and horizontal force-velocity (FV) profiles in 176 rugby union players participating in amateur club, professional, and international competitions. Rugby players were divided into 5 positional groups: tight-5 forwards (n = 63), loose forwards (n = 35), inside backs (n = 29), midbacks (n = 22), and outside (n = 27) backs. Sprint performance was averaged across 2 trials of a maximal 30-m sprint, separated by a 3-minute rest. The results demonstrated differences in sprint performance and FV profile characteristics across competitions and positional groups. Specifically, both international and professional players possessed significantly faster split times and superior FV profiles than club players (p < 0.01; effect size [ES]: 0.22–1.42). International players were significantly faster across 0–10 m than professional players (p = 0.03; ES: 0.44–0.47), whereas professional players had faster 10–20 m times (p = 0.03; ES: 0.37–0.41) and a more force-dominant profile (p < 0.01; ES: 0.71–1.00). Across positions, split times decreased and maximal velocity characteristics increased in proportion with increasing positional number, with outside backs being the fastest (ES: 0.38–2.22). On the other hand, both forwards groups had more force-dominant profiles and average sprint momentum across all distances than all backs positions. Interestingly, loose forwards had a more forceful profile and slower 10-, 20-, and 30-m split times but similar maximal velocity characteristics to inside backs, highlighting unique positional demands and physical attributes.
The Challenge of Managing Stress Versus Distress
Authors: Kraemer William J. , Nitka Mike
Published: April 2021

Being aware of factors that contribute to stress that can lead to “distress” is the first step in optimizing an athlete's environment for optimal training and performance. Distress is the body's inability to successfully cope with external stressors. Whether from a physical perspective of “too much too soon” or nonfunctional overreaching in a conditioning program or from environmental challenges of heat or from psychological challenges related to depression, awareness, assessment, and actions are needed to ensure an athlete's health and wellness. Factors such as nutritional deficiencies and reduced recovery between sessions may increase overall stress possibly leading to overreaching, overtraining, and overuse. Because of the highly individual responses to both training and outside stressors, individualization of programs, monitoring, and interventions are needed. Ultimately, managing athlete stress is a “team approach.”
The Role of Scientific Activities in the Germany`s Chambers of Commerce
Authors:   Institute of Europe, Russian Academy of Sciences, Ivanova Anna
Published: April 2021

The analysis of a model of the German Chambers of Commerce helps to explore the assumption, that along with consulting, expert function (scientific and analytical), viz. collecting of empirical data (business surveys and interviews with entrepreneurs), analytics (preparation of analytical reviews for member firms), expert networking (joint projects with scientific institutions; holding events with the involvement of practicing experts and economic researchers) is one of its key activities. Four main directions are formulated in this area: data collection, interaction with researchers (preparation of analytics), dissemination, and the use of the results on decision-making level (regional/federal government) in order to protect business interests. In conclusion, the author highlights a number of relevant principles for chamber-nets developing in RF and other EAEU countries.
“Parallel Societies” and a Turn Towards Soft Assimilation
Authors:   Leningrad State University Pushkin, Pronina Tatyana
Published: April 2021

The article presents an overview of theoretical discussions about the content and formats for the use of the term “parallel societies” in social and humanitarian discourses and political debates on immigration. Based on the previous immigration studies (of the Chicago sociological school, T. Meyer in Germany, etc.), a number of authors point out negative connotations associated with this term due to phobias of Islamic radicalism. Other researchers propose to abandon the term "parallel society". They insist on the hollowness of this concept, which just reflects the fears of a certain part of European society. However, the majority of specialists pay attention to the ambiguous nature of segregation as the basis for the development of “parallel societies”, acting for immigrants as a protection mechanism against discrimination and facilitates their integration. Furthermore, the researchers provide empirical evidence of a link between the deterioration of social and economic conditions and the growth of anti-immigrant sentiment. The study highlights the paradoxical conclusion that immigrant communities with a strong influence of religion lack public “parallel” structures that represented their interests in the majority society. Meanwhile the states do not have the appropriate tools to establish a dialogue with religious immigrant organizations and to oppose the promotion of their life style. In conclusion, the article emphasizes the growing tendency to abandon the strategy of multiculturalism and return to a soft variant of assimilation and integration.
Evidence Illegally Obtained by Private Investigators and Its Use Before International Criminal Tribunals
Authors: Heinze Alexander
Published: April 2021

This article examines the rationales to exclude evidence before International Criminal Tribunals that has been illegally obtained by private investigators. The appeal of private investigations has now reached the level of international criminal justice, with the establishment of the Commission for International Justice and Accountability. Investigative staff at the International Criminal Court and other International Criminal Tribunals are dependent on the work undertaken in the field by human rights monitors as fact finders, employed by IGOs, NGOs, and, in some cases, by governmental agencies. Considering the importance of private investigators for the administration of those Tribunals, potential dangers of such a cooperation easily take a backseat in a car that is driven by the anti-impunity agenda. Scenarios of investigators offering money to witnesses in return for information about a suspect and his or her criminal activities are a reality. While case law has addressed the topic of illegally obtained evidence by national authorities, the fate of evidence collected by private individuals in breach of human rights has rather been neglected. This article provides a conceptual basis for the exclusion or admission of this evidence.
The 21st Century Life Skills-Based Education Implementation at the Non-Formal Education Institution
Authors: Prasetyo Iis , Suryono Yoyon , Gupta Sachin
Published: April 2021

Life skills education basically aims to improve the quality of human resources to overcome various problems in their daily lives in the era of the 21st century. This study was aimed to describe the non-formal education institution managers’ efforts to implement the 21st-century life skills education. The researcher employed the quantitative approach with a survey research design in Yogyakarta City and Sleman District. The respondents were non-formal education institution managers. The data were collected using questionnaires and analyzed using the quantitative analysis method. The results of the study show that the implementation of 21st-century life skills education is still limited to the knowledge and hard skill developments. The unexplored materials include thinking skills which consist of conceptual thinking, creativity, innovation, problem-solving, critical thinking, decision-making, and metacognition. The novelty of this research is the findings in this study provide a more detailed description of the weaknesses of non-formal education institutions in providing life skills education.
Multilevel Design in the Implementation of Blended Learning in Nonformal Education Unit
Authors: Shantini Yanti , Hidayat Dayat , Oktiwanti Lesi , Mitsuru Takahashi
Published: April 2021

CLC as one of the non-formal educational institutions affected by the COVID 19 outbreak must organize online teaching and learning activities under government instructions as an effort to prevent transmission of the COVID 19 pandemic.  Lack of experience in conducting online learning makes institutions confused about running the learning process due to educators and managers' limited ability to implement online education. It is necessary to study more deeply what learning strategies CLCs should carry out during the pandemic period. The approach used in this study was a mixed-method with 10 CLC respondents spread across West Java. From the findings in the field, learning at CLC during the pandemic was still ongoing. Tutor only used message applications for delivering learning material and evaluation process. They do not even implement it in the online learning management system. For this reason, CLC can pilot a multilevel blended learning system model. The implementation of the model system starts from institutional management, program management, to learning management by tutors.
The Effect of E-Learning on Students' Learning Interest in the Equivalence Education Program
Authors: Shofwan Imam , Aminatun Siti , Handoyo Eko , Kariadi Mustasyfa Thabib
Published: April 2021

The Equivalence Education Program is non-formal education that applies learning with the e-learning system to substitute conventional learning in formal education school. This study aims to identify and analyze (1) e-learning conducted by students, (2) students 'interest in learning, and (3) the effect of e-learning on students' learning interest in the Package C Equivalence Program at PKBM Pioneer Karanganyar. The method used is a quantitative approach focusing on the ex post facto approach. The research sample was 45 students of Package C at PKBM Pioneer Karanganyar, out of a total population of 141 Package C students. The data were collected using questionnaire and documentation. The analysis technique used is statistical and inferential analysis techniques focusing on simple linear regression analysis techniques. The results showed that (1) Package C students at PKBM Pioneer Karanganyar appreciated that the e-learning was equivalent to online learning (2) Package C students at PKBM Pioneer Karanganyar had high learning interest, (3) there was a positive influence and e-learning was significant for students' interest in learning in the Package C Program at PKBM Pioneer Karanganyar. The benefit of this research is to provide an overview of online learning that is fun to students.
Poverty Alleviation by Education is A Kind of Awakening and Discovery: In Memory of the “Poverty Alleviation War” of a Retired Middle School Principal in Eastern China
Authors: Hai Yuhan
Published: April 2021

Abstract: The development of education to improve poverty in the region has become an essential direction of the world’s poverty alleviation work. In the poverty alleviation by education work in China, educators who are on the front line of poverty are determined by education and nurturing their wisdom, leading countless children from families out of poverty and toward hope. In 2016, Liqun Chen, the principal who retired from a prestigious high school in eastern China loving the Miao Townships, insisted on combining poverty alleviation with supporting aspirations, using the love and responsibility of a “teacher” to inject new spirit into basic education in ethnic areas. He ignited dreams and hopes for children in frontier regions. This article elaborates on Liqun Chen’s help and aspirations in Taijiang County from the perspectives of students, teachers, and regions.
Feedback control modulation for controlling chaotic maps
Authors: Hansen Roberta , González Graciela A.
Published: April 2021

Based on existing feedback control methods such as OGY and Pyragas, alternative new schemes are proposed for stabilization of unstable periodic orbits of chaotic and hyperchaotic dynamical systems by suitable modulation of a control parameter. Their performances are improved with respect to: (i) robustness, (ii) rate of convergences, (iii) reduction of waiting time, (iv) reduction of noise sensitivity. These features are analytically investigated, the achievements are rigorously proved and supported by numerical simulations. The proposed methods result successful for stabilizing unstable periodic orbits in some classical discrete maps like 1-D logistic and standard 2-D Hénon, but also in the hyperchaotic generalized n-D Hénon-like maps.
Joint universality of periodic zeta-functions with multiplicative coefficients. II
Authors: Laurinčikas Antanas , Šiaučiūnas Darius , Tekorė Monika
Published: April 2021

In the paper, a joint discrete universality theorem for periodic zeta-functions with multiplicative coefficients on the approximation of analytic functions by shifts involving the sequence f kg of imaginary parts of nontrivial zeros of the Riemann zeta-function is obtained. For its proof, a weak form of the Montgomery pair correlation conjecture is used. The paper is a continuation of [A. Laurinčikas, M. Tekorė, Joint universality of periodic zeta-functions with multiplicative coefficients, Nonlinear Anal. Model. Control, 25(5):860–883, 2020] using nonlinear shifts for approximation of analytic functions.
ESTIMATION OF EXPOSURE LEVELS OF TERRESTRIAL BIOTA AND RADIATION EXPOSURE AROUND IPEN´S FACILITIES
Authors: Cavalcante Fernanda , Nisti Marcelo Bessa , Saueia Cátia Heloisa R.
Published: April 2021

Humans are exposed to natural radiation; soil is a major source of external and internal exposure of radiation. The aim of this study is to evaluate the exposure levels of terrestrial biota and to estimate the radiation exposure around Instituto of Pesquisas Energéticas e Nucleares (IPEN) facilities. The ERICA Tool was used to calculate the exposure levels of terrestrial biota; the estimation of radiation exposure for humans was determined using a model proposed by UNSCEAR and Excess Lifetime Cancer Risk. Six soil points were collected and their activity concentrations were measured by gamma spectrometry. Two soil points showed a risk coefficient greater than 1, suggesting that the screening dose ratio of 10μGy h-1 might be exceeding for the most exposed species, namely lichen and bryophytes, even though the activity concentration values of the analyzed radionuclides showed no evidence of soil contamination due to the atmospheric discharges of the IPEN facilities. Thus, the radioactive discharges in the soil from all facilities are negligible. Hence, the authors concluded that the ERICA Tool can be useful in assisting environmental radiological monitoring program for decision-making, especially regarding: points collected, sample types and sampling frequency.
Dosimetric evaluation in the thyroid region of individuals occupationally exposed during the liberation of the iodotherapy room
Authors: Filipov Danielle , BARBOSA MARIANA , DIAS CARLA ROBERTA BARROS RODRIGUES , COLAÇO ISY MEDEIROS
Published: April 2021

Iodotherapy is a complementary treatment to thyroid resection surgery, being performed with radioactive iodine (131I). To do the treatment, the patient must be hospitalized due to the exposure of other people to the ionizing radiation emitted by the radiopharmaceutical. The patients' hospitalization time is dependent on the activity of radioactive material administered and may be from one to two days. After the patient´s discharge from hospital, another one may be hospitalized, however, the room must be monitored by the technical staff in order to verify whether there is radioactive contamination due to the previous patient. Thus, the present study aims to verify the dose received in the staff´s thyroid region during the monitoring of the therapeutic room after discharge, since the thyroid is one of most sensitive to iodine. Two occupationally exposed staffs (called “V1” and “V2”) were monitored using TLDs positioned in the thyroid region. V1 and V2 were monitored for 7 months and 3 months, respectively, because of the workflow of the clinic where the research was performed. With the doses received, during these periods, it was estimated that the annual doses received by V1 and V2 were, respectively, (11.2 ± 5.2) mSv and (12.7 ± 1.0) mSv. These results are below the dose limits established by the ICRP and other international guideline, which reveals that the research clinic is concerned with occupational radiation protection and no other radiological protection actions, based on the thyroid exposure, are necessary.
RADIOCHROMIC FILM CALIBRATION FOR DOSIMETRY IN CHEST CT SCANS
Authors: Gomez Mauricio , Mourão Arnaldo Prata
Published: April 2021

Phantoms can be used as quality control objects in computed tomography (CT) imaging and dosimetry in specific regions of interest. By means of phantom tests, alternatives can be created to optimize the acquisition protocols and thus modify the acquisition parameters to deposit lower levels of radiation to the patient, seeking a quality image for the diagnosis. Radiochromic films, GAFCHROMIC XR-AQ2 model, are used to measure the dose-response when exposed to radiation. The profile of the absorbed dose within a phantom is important because it allows an understanding of a larger reality. Calibration curves were obtained from radiochromic films using a cylindrical phantom made of polymethyl methacrylate (PMMA). This phantom has five openings, one central and four peripherals lagged 90°. The phantom was positioned in the isocenter of the gantry of a scanner manufactured by the Toshiba, model Asterion, using 120 and 135 kV voltage of the X-ray tube. The phantom peripheral openings were positioned similarly to positions 3, 6, 9, and 12 of the analog clock. The ionization chamber was used for the record values of the Air Kerma in PMMA, in the central and 12 positions when the central slice of the phantom was irradiated in the axial mode. The other openings were filled with rods also made of PMMA. Radiochromic film strips were placed into PMMA rods and the central and 12 openings were filled. The central area of the phantom was scanned in helical mode. The film strips were digitized and processed their images to have the calibration curve survey.
Characterization of TL and CW-OSL signals of natural brazilian topaz with different colours
Authors: Dos santos Matheus Fernando , Bruno Ferreira de Souza Leonardo , Khoury Asfora Viviane , Barbosa de Carvalho Júnior Álvaro , Saito Monteiro de Barros Vinicius , Luiz Guzzo Pedro , Jamil Khoury Helen
Published: April 2021

Topaz [Al2SiO4(OH,F)2] is usually found in nature and can presents different colours. The aim of this paper is to evaluate the thermoluminescence (TL) and the optically stimulated luminescence (OSL) response of five types of topaz collected from three different Brazilian states. The topaz samples studied have a yellow, blue and colourless coloration. The TL results showed that colourless samples from the state of Rio Grande do Norte present a TL glow curve with a main peak at ~260ºC. The others colourless topaz from Teofilo Otoni e Mato Grosso do Sul, besides the peak of ~260ºC, the present another peak at 160 ºC. The highest TL intensity was observed with the colourless topaz from RN. A linear TL dose curve response was also observed with these samples from the gamma radiation of 60Co in the range of 0.01 Gy to 3.5 Gy. The blue light stimulation (BSL) showed almost the same intensity response for the three colourless topaz samples. None topaz sample showed response to optical infrared stimulation (IRSL).
Plutonium-238: The Fuel Crisis
Authors: Smith Ricardo Bastos , Romero Fernanda Cristina , Vicente Roberto
Published: April 2021

Plutonium-238 is currently still the best fuel to power satellites to be sent to deep space in regions where the solar panels can no longer efficiently receive the sunlight. For 50 years, the National Aeronautics and Space Administration (NASA) has used this radioisotope as a fuel in radioisotope thermoelectric generators (RTGs) installed on satellites such as Pioneer 10 and 11, Voyager 1 and 2, Cassini-Huygens and New Horizons, as well as the various rovers sent to the Moon and to Mars, among others. Plutonium-238 is not a naturally occurring isotope on the planet, it was produced in greater quantity during the Cold War period as a by-product of the production of Plutonium-239 used for nuclear bombs. However, after the shutting down of the Savannah River reactors in 1988 and the ending of the Soviet Union in 1991, the United States stock of Plutonium-238 has been increasingly reduced, which threatens NASA's future space projects. This paper presents a brief bibliographic review about the subject, as well as commentaries on the options available to the United States, from restarting the production of this fuel, to possible alternatives for a new type of fuel or equipment that may supply the spacecrafts.
The effect of data standardization in cluster analysis
Authors: Nogueira André Luiz
Published: April 2021

The application of multivariate techniques to experimental results requires a responsibility on behalf of the researcher to understand, evaluate and interpret their results, especially the ones that are more complex. In this work, the impact of three standardization techniques on the formation of clusters by the Kohonen neural network were studied. The techniques studied were logarithm (log10), generalized-log and improved min-max. The studies were performed using two databases consisting of 298 and 146 samples and containing the mass fractions of As, Na, K, La, Yb, Lu, U, Sc, Cr, Fe, Cs, Eu, Tn, Hf and Th, determined by neutron activation analysis. The results were evaluated using validation indices.
Development and application of an approach for safety assessment of radioactive waste storage facilities for accidental scenarios
Authors: Cota Stela Dalva Santos , Passos Ricardo Gomes , De Vasconcelos Vanderley
Published: April 2021

Worldwide there is a huge amount of radioactive waste, including disused sources, decommissioning waste, and naturally occurring radioactive material (NORM) waiting for final disposal, the so-called storage facilities. Results of safety assessment of such facilities are usually required in decision-making during design, modification, safety improvements, periodic safety reviews, and licensing activities. Quantitative safety assessment methodologies used in many areas of nuclear industry involves the evaluation of risk through the definition of scenarios, likelihoods, and consequences, for normal operation and accidents. There are many techniques that can be used in each one of these steps. For screening the accident scenarios, qualitative techniques such as failure modes and effect analysis (FMEA) are available. For a quantitative assessment of occurrence probabilities of undesired events, logical and graphical tools such as fault tree analysis (FTA) are employed. Consequence assessments involve the dose assessment in the workers and the impact of the released materials in the environment and of public exposure to radiation. This work analyzes the application of these traditional safety assessment approaches to storage facilities and how they can be applied to complement specific methodologies used in this area, such as the Safety Assessment Driving Radioactive Waste Management Solutions (SADRWMS), implemented in Safety Assessment Framework (SAFRAN) software tool, made available by International Atomic Energy Agency (IAEA).
Total phenolic compounds of irradiated chia seeds
Authors: Chierentin Gabriel Souza , Teixeira Bruna Saporito , Del Mastro Nélida Lucia
Published: April 2021

Chia seeds (Salvia hispanica L.) is a good source of oil, protein, dietary fiber, minerals and polyphenolic compounds. In order to study the influence of the processing methods on the content of phenolic compounds, the objective of this work was to evaluate the effect of gamma radiation, doses 0-20 kGy, on the total phenolic compounds extracted from chia seeds. Seeds were first defatted and extracts produced with proper solvents. Total phenolic content was determined according to Folin-Ciocalteu’s method and the extraction solvents applied were ethanol 100%, ethanol 70%, ethanol 50%, methanol 100%, methanol 70% and methanol 50%. When using ethanol 100%, ethanol 70 %, ethanol 50%, methanol 100% and methanol 70%, the extraction yield was independent of the absorbed dose. With methanol 50%, the irradiation process affected positively the total phenolic yield from of chia seeds. In general, the absorbed dose as well as the nature of the solvent affected the extraction yield, although in a limited manner.
The influence of the lead eyewear geometry on the doses to the eye lens
Authors: Souza Santos William , Neves Lucio Pereira , Perini Ana Paula , Santos Carla de Jesus , Belinato Walmir , Caldas Linda V. E.
Published: April 2021

The scattered radiation from interventional procedures is an important source of radiological risk for the medical staff. Considering all affected organs, the eye lens are among the most critical organs. As pointed out by several studies, even for low radiation doses, the appearance of cataract may occur. Considering this scenario, the radiation doses to the eye lens were determined using three different lead eyewear models commonly employed. The fluoroscopist was represented by an adult virtual anthropomorphic phantom (MASH3), coupled to the Monte Carlo code MCNP6.1™, in a typical cardiac interventional radiology procedure. The eyewear had thickness 0.5 mmPb each, and the evaluation was carried out for four different beam angulations (PA, LAO90, LAO65 e RAO65), 80 kVp of tube voltage and HVL of 4 mmAl. The results pointed out that the shielding efficiency has a strong dependence on the eyewear type utilized, which may be very useful for the decision-making during the acquisition of such equipments.
Development of an automated source port in IoT for application in industrial process tomography
Authors: Vergaças de Sousa Carvalho Diego , Henrique de Mesquita Carlos , Martinez Gregianin Gustavo
Published: April 2021

Computed tomography technology uses an electromagnetic radiation source or particulate radiation source, to analyze / study different samples that can range from living organisms to the most diverse objects (rocks, phantoms, etc.). The use of the radioactive materials may cause harm to the operator if he is exposed to the source of radiation, so aiming at the safety of the operator, the objective of this work is to develop an Internet of Things automation system for the opening of the Industrial Process Tomography source port for industrial tomography applications. Thus, this system can drive the stepper motors through this platform can be opened at a safe distance to the operator, avoiding the operator to take radiation dose to perform this operation. For the IPT project, five source ports were made so that each was positioned diametrically opposite each array of detectors. In this project we used 192Ir sources that have activity of 18,500 MBq and that were produced in the reactor IEA-R1, from the neutron bombardment of the pellet containing stable isotope 191Ir. The main characteristics of 192Ir are: half-life of 74.2 days; radiation energy from 0.13 to 0.65 MeV. For the safety of the operator during the opening of the sources, an automated opening system with IoT that can be activated with software installed on the tomography or by a smartphone application  by the MQTT protocol, which makes it possible to be monitored in real time at long distance showing the opening and closing status of each source port.
A bibliographical review on the concept of biological effects of ionizing radiation in Brazilian publications
Authors: Gonçalves Gabriel De Lima , Delgado José Ubiratan , Razuck Fernando Barcellos
Published: April 2021

At the end of the nineteenth century, with the use of ionizing radiation for the benefit of humanity in various sectors of society, its effects on human health became evident. In this way, it is necessary to clarify the population about the main aspects related to the ionizing radiation applications, in order to better understand the concepts regarding their effects on health. And one of its main effects, within the area of radiological protection and medical physics, is called by Biological Effects. This is because ionizing radiations, due to their energy range, have the property of interacting with matter, and can alter the structure of cells by ionizing their atoms. Once it reaches the cells, ionizing radiation can produce damage, especially in DNA. This may occur either by the action of the radiation itself (direct mechanism) or by toxic radicals formed by the hydrolysis (indirect mechanism). These effects, over time, were identified and described, mainly from situations in which the man was acutely exposed (by accidents or medical use). In this sense, this paper proposes a bibliographic review of some concepts and definitions found in the literature on Biological Effects, mainly in Brazilian publications. With the purpose of not presenting a definitive theoretical model, but rather demonstrating the range of existing concepts, the objective of this paper is generating a debate about the variety aspects that may be related to the subject, reaffirming the importance of the topic for the area of radiation protection.
Effect of ionizing radiation on the color of featherwork.
Authors: Delgado Vieira Ana Carolina , Kodama Yasko , Otubo Larissa , Santos Paulo de Souza , Vásquez Salvador Pablo Antonio
Published: April 2021

Featherwork collections are usually stored and managed by ethnographic museums. Even though the featherwork manufacturing is still practiced by the indigenous communities, the offer of raw material and the contact with the surrounding society ended up reducing the production scale of such objects. Consequently, the preservation of the material culture is very important, particularly in museums. Biodegradation can affect featherworks mainly by xylophagous insects and moths’ action. The tropical Brazilian weather contributes to the contamination and proliferation of insects and fungi making the preservation conditions difficult. The use of gamma radiation for the disinfection of cultural heritage objects has shown to be a safe process and an excellent alternative to traditional methods usually involving toxic chemical pesticides. In this work are presented the preliminary results of the ionizing radiation effects on the color and morphological properties of a featherwork from the Museum of Archeology and Ethnology of the University of São Paulo (MAE/USP). Samples of feathers were selected from the artifact and irradiated with gamma rays at the Multipurpose Gamma Irradiation Facility at IPEN, applying absorbed doses between 0.5 kGy to 200 kGy. The results shown had no significant changes on color and morphological properties within the disinfection absorbed dose range applied.
SHELF-LIFE OF PAPAYA NECTAR SUBMITTED TO IONIZING RADIATION
Authors: Harder Marcia Nalesso Costa , Andrade Tatiane , Reis Fernanda M. , Feitosa Natália M. , Pereira Pâmela , Roberto Suzane , Neme-Oyan Fernanda Faganello , Harder Larissa Nalesso Costa , Oliveira Simone Raymundo , Arthur Valter
Published: April 2021

A kind of the consumption forms of drinks presentation that has grown and appreciated for the most people is the nectar. The papaya nectar had recognized as a differentiated form of this fruit, where the industry also gains in time of conservation, since the papaya is an extremely perishable fruit. The aim of this study was to evaluate gamma radiation as a way of conserving papaya nectar. Papaya nectar was developed and subjected to gamma radiation at the dose of 1kGy in a dose tax of 0.356 kGy.hour-1 and compared this treatment with the control (0kGy). According to the results obtained, can be concluded that the dose used was adequate for the conservation of this product for the period evaluated reaching the aim.
Use of the Grubbs test to study the homogeneity of a NaI(Tl) detector
Authors: Ramos Leticia Lins , Salgado César Marques , Salgado William Luna , Dam Roos Sophia , Ferreira Francisco Oliveira
Published: April 2021

The NaI(Tl) detector is one of the most used in gamma ray spectrometry because it presents high counting efficiency for gamma rays in a wide range of energy. The crystal can have a lower efficiency that can be indicated by the effects of its aging by several factors such as: the reaction of sodium iodide with magnesium oxide, absorption of water vapor by crystal, and problems related to photomultiplier. In an experiment, several measures can be take and when a doubt exists between one of the measured values it is possible to use a statistical test. Grubbs test is designed to verify the presence of extreme values in sample observations. This paper presents a methodology that has the objective of evaluating the homogeneity of a NaI(Tl) scintillation detector using the Grubbs test to validated the crystal homogeneity. The study pre-established five differents locations in frontal area of detector where measurements were performed using a 137Cs standard source in order to calculate the standard deviation.
Influence of contrast injection flux on the outcome of the angiotomography for the diagnosis of pulmonary embolism
Authors: Felix Warley Ferreira , Veloso Maria Auxiliadora Fortini , Abrantes Marcos Eugênio Silva , Miranda Ramon Vitor de , Rosas Vitor Araújo
Published: April 2021

With the development of computed tomography, tomography examinations have been replacing other modalities of imaging tests. Computed tomography angiography to pulmonary thromboembolism, for example, has been replacing pulmonary scintigraphy of ventilation/perfusion and angiography of pulmonary vessels. But angiotomography to the pulmonary thromboembolism is a complex examination, where factors such as scanning time, contrast injection flow, venous access caliber, venous access puncture site, use of the contrast injector, auto-trigger parameters, among others, interfere in the outcome of exam in the studied population. In this study, we performed the contrast ratio (RZC), relative the opacification of contrast in the trunk of the pulmonary artery and the descending aorta, which may vary according to the injection protocol used, determined by the flow of contrast injection (ml/s) associated with the auto-trigger (HU) parameters of the density reading in automatic mode of the equipment. For the injection of manual contrast, and its mean and standard deviation of RZC (2.66±3.56), for the flow (ml/s) and automatics reading (HU) protocols the means and standard deviations RZC consecutively are: 3.5 ml/s and 90 HU (3.68±2.79); 3.5 ml/s and 70 HU (1.90±0.72); 4.0 ml/s and 70 HU (1.98±0.56); 3.0 ml/s and 80 HU (2.15±0.89); 3.5 ml/s and 80 HU (1.50±0.36); 4.0 ml/s and 80 HU (3.91±3.22); 4.5 ml/s and 80 HU (4.69±4.82); 5.0 ml/s and 80 HU (4.27±3.78). The technique with the best result in the average level of RZC was the one that used a flow of 4.5 ml/s and auto-trigger in 80 HU.
Efficiency stability of HPGe detectors under distinct count rates
Authors: Zahn Guilherme Soares , Genezini Frederico Antonio
Published: April 2021

In this work the reproducibility of the efficiency of different HPGe detectors was analyzed under a series of different conditions. The detectors studied were plugged either to a regular analogical amplifier or to a digital signal processing (DSP) device, in order to evaluate the possible differences between either setup. Detectors were inspected by performing a long series of sequential measurements with standard calibration sources, and comparing the standard deviation of the number of counts per second in each series to the uncertainty of the individual measurements. Detectors were also subjected to distinct count rates, in order to verify the possible experimental issues associated with this parameter. The results allow a discussion on the stability of the detectors’ efficiencies over a few days, the possible dependence with the count rate, and the estimation of the uncertainty related to the efficiency variation.
Preliminary studies on electron beam irradiation as a treatment method of radioactive oil sludge
Authors: Tessaro Ana Paula Gimenes , Vicente Roberto , Marumo Júlio Takehiro , Teixeira Antonio Carlos Silva Costa , Araujo Leandro Goulart de
Published: April 2021

Radiation-induced advanced oxidation processes have been proposed for the treatment of various types of wastes. However, electron beam technologies for the removal of recalcitrant compounds in petroleum wastes are still poorly understood. This work aims at evaluating the effects on the degradation of organic matter from oil sludge by electron beam irradiation. Characterization methods were employed to identify the chemical elements present in the waste. Radiometric analysis was performed to identify radionuclides and measure dose rates. Preliminary immobilization of the untreated waste with cement indicated resistance values very close to the minimum established in national regulation. To treat the waste, an electron beam accelerator, model Dynamitron II, with variable current up to 25 mA was employed and the irradiation doses ranged from 20 to 200 kGy. Solutions were prepared with an initial H2O2 concentration of 1.34 mol·L-1. The effects on the removal of total organic carbon are discussed.
Analysis of South America coins of the XIX and XX centuries by XRF technique
Authors: Nardes Raysa Costa
Published: April 2021

In this work, the elemental composition of 21 coins from nineteenth and twenty centuries of South America belonging to a private collection were performed using the X-Ray Fluorescence (XRF). Different coin numismatic catalogs were used as reference material. The XRF measurements were performed using ARTAX 200 system (Bruker AXS Inc., Madison, WI, USA), which consists of an X-ray tube with Mo anode and a Silicon Drift Detector. The analyses were performed with a voltage and current of 40 kV and 600 μA, respectively, and an acquisition time of 100 s. It was possible to evaluate that all twenty-one pieces were made from metallic alloys. The major elements found were Fe, Cu, Ni, Zn and Sn. Twenty coins were consistent with their cataloged version, on the other hand, only one coin showed a different chemical composition from its cataloged version. So, this result can be an indication that this coin may be a fake.
Issues on the Electron Stopping Power Modulated by Magnetic and Electric Fields
Authors: Avelar Matheus Corrêa Dantas , Campos Tarcisio Passos Ribeiro , De Castro Túlio Henrique Lopes Gomes , Guimarães Paulo Sérgio Soares
Published: April 2021

Ionizing radiation has been employed in conjunction with various clinical modalities for therapeutic purposes. Often, surgery, chemo and radiation therapies have been combined on the arsenal against cancer. Nontraditional techniques, as Tumor Treating Fields (TTF) that uses low-intensity variable electric fields, have also been employed for the treatment of brain tumors, glioblastoma multiforme (GBM), with promising results in reducing the harmful radio and chemotherapy effects, while maintaining the same tumor control rates. The combination of electromagnetic field and chemotherapy has already held a clinical investigation; however, it is missing the experimental and theoretical studies coupling electric and magnetic fields with electron radiotherapy. Herein, a theoretical analysis involving the Stopping Power of electron particles in conjunction with static electric and magnetic fields (E, H) was addressed in order to study the relevance of the use of external electromagnetic fields in radiotherapy. The findings reinforce the possibility of application of the coupling magnetic field with electron radiotherapy, and open a horizon to future experimental and clinical studies if the relevance is enough.
Effect of ionizing radiation on the color of botanical collections - exsiccata
Authors: Lima Leni Meire Pereira Ribeiro , Kodama Yasko , Otubo Larissa , Santos Paulo Souza , Vásquez Pablo Salvador
Published: April 2021

Estratégias de conservação e preservação são essenciais para gerenciar coleções botânicas, especialmente para espécimes de herbário seco também conhecidos como exsicatas, geralmente referindo-se a um conjunto de espécimes identificados pertencentes a táxons e distribuídos entre todos os herbários do mundo. Particularmente, essas coleções são muito sensíveis ao ataque de fungos e insetos. Nos últimos anos, a desinfecção por radiação ionizante tornou-se uma estratégia eficaz para preservar objetos do patrimônio cultural e materiais arquivados, com excelentes resultados. Neste trabalho, foram estudados os efeitos nas propriedades de cor da radiação gama em amostras de exsicatas. Assim, dois exsicatas, amostras botânicas prensadas e desidratadas foram selecionados no Herbário Dom Bento José Pickel (SPSF), localizado em São Paulo (Brasil). Essas amostras são provenientes das famílias Asteraceae e Solanaceae e foram coletadas em 1946 e 1984. A irradiação foi realizada no Centro de Irradiação Gama Multiuso do IPEN, aplicando doses absorvidas de 1 kGy, 6 kGy e 10 kGy, valores de dose absorvida para desinfestação e desinfecção. Os resultados foram analisados por colorimetria com escala de espaço de cores CIELAB e microscopia eletrônica de varredura. Os resultados mostraram que não houve alterações significativas nas propriedades morfológicas colorimétricas das amostras. Os resultados foram analisados por colorimetria com escala de espaço de cores CIELAB e microscopia eletrônica de varredura. Os resultados mostraram que não houve alterações significativas nas propriedades morfológicas colorimétricas das amostras. Os resultados foram analisados por colorimetria com escala de espaço de cores CIELAB e microscopia eletrônica de varredura. Os resultados mostraram que não houve alterações significativas nas propriedades morfológicas colorimétricas das amostras.
Development of a yz scan system for the improvement of an automatic system of radioactive seed implants in prostate brachytherapy
Authors: Silva Leonardo Santiago Melgaço
Published: April 2021

Brachytherapy is the use of radiotherapy with insertion of radiation sources close to the site that needs treatment. It has become an extremely sought-after option by research fields for its impressive efficiency and practicality. In addition to being a fast-paced procedure, it allows patients to leave hospital care very soon after it is done, without pain or with minor discomfort, which can be considered an advantage.The brachytherapy procedure is divided into two stages, obtaining images of the region where seed implantation will take place and the application itself.  The images are obtained by ultrasonography, which will guide the insertion of the needle into the patient's body.  During the injection, the patient is anesthetized and immobilized, so that movements that compromise the accuracy of the needle, which, by the current manual method, are already subject to oscillations are avoided.Currently the application of radioactive seeds is done manually by a clinician who uses needles and monitors their positions through the images generated by ultrasound equipment. Thus, the main objective of this project was to improve the prototype of the Prostate Seed Implantation System (SISP), developed by the Nuclear Engineering Department of the UFMG (Nuclear Engineering Department).  Thus, the device allows automated scanning on x, y and z axes, facilitating the application of radioactive seeds in prostate brachytherapy treatments, which in current treatments are done manually by the clinician. And the possibility of controlling this movement via BLUETOOTH technology.