bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of expanded vermiculite to use as natural barrier in repository
Authors: Teixeira Thais Braga , De Tello Clédola Cássia Oliveira
Published: April 2021

Brazilian National Nuclear Energy Commission – CNEN – is responsible to build a repository for the low and intermediate--level radioactive wastes generated in Brazil. In accordance of Brazilian legislation it will be a near surface one. In the repository, treated waste will be stored, which will be surrounded by engineering and natural barriers, in order to prevent the release of radionuclides, during the required time to their decay to the limit levels. The focus of this study is to characterize the expanded vermiculite, which can be used as a natural barriers, over and under the engineering barriers and also as a backfill. They have the function of limiting water infiltration and stabilizing the disposal system, filling the empty spaces, controlling the gases and delaying the release of radionuclides. In this paper is presented the characterization of an expanded vermiculite. The tests to determine its physical chemical properties were based on a clay characterization Protocol. The granulometric analysis was performed using a sieving method. The moisture content was established by the gravimetric method of weight loss, and the specific surface area by the BET method. The helium ultrapicnometer method was used to determine the density. The microstructure was analyzed by X-ray diffraction and scanning electron microscopy. The results indicate that the studied vermiculite would be efficient as a natural barrier of the Brazilian surface repository, as the it presented a stable structure.
Brazilian clays for environmental solutions applied to radioactive waste management
Authors: Machado Gabriel Gonzalo , Krupskaya Victoria , Zakusin Sergey V , HARADA Julio , De Souza Rodrigo Papai , Araujo Leandro Goulart , Espinosa Denise Crocce , Montalvan Edy L.T. , Kahn Henrique , Vicente Roberto , Guilhen Sabine
Published: April 2021

Clays have been adopted in most nuclear waste producing countries as a key constituent in engineered barrier systems for final disposal facilities at all levels of radioactive wastes (LILW-SL, LILW-LL, and HLW). The following study presents a thorough characterization upon five Brazilian clay-rich deposits, mostly smectite bearing clays, aiming to evaluate their expected performance as barrier under the conditions associated to a Low and Intermediate Level Waste Repository; being the former a matter of national strategic interest. Samples coming from the Brazilian states of Paraná, Bahia, Paraíba, and Maranhão were treated and analyzed by means of X-Ray diffraction as main technique, and complemented by FTIR, LALLS, XRF, and SEM-EDS, in order to establish the mineralogical composition, particle size distribution, and chemical composition. Moreover, several standard clay treatments over the <1 μm size fraction were carried out to reveal information regarding layer charge, major interlayer cations, unit formula and other crystal features of smectite species present in a mineralogical assembly, aiming to provide information for the construction of a molecular model over which would be realistic to simulate the diffusion of radionuclides. Results obtained on 133Cs adsorption experiments indicate that mineralogical composition would probably be the single most influential factor controlling transport capacity of positively charged radionuclides in the current setup. The composition is especially expressed in terms of smectite contents, favoring montmorillonite rich materials containing majorly Na+ as compensating cation in interlayer position. All tested samples can be considered as suitable candidates to be used in the design of final destination storage for nuclear waste. Thus, efficiency on 133Cs adsorption trials also indicate that these materials could have potential uses as sorptive matrices (Sorbents) for water treatment of radionuclide polluted waters such as TENORM waste waters. However, these trends are yet to be contrasted against hydraulic conductivity measurements and swelling pressure in order to have a more comprehensive perspective of this clayey prospects as barrier enhanced layer; aligned to the multilayer barrier system approach for nuclear waste management.
Impact of voxel size on microCT morphometric analysis of the pumpkin toadlet
Authors: Dos Santos Caio Sorrentino , Araujo Olga Oliveira , Romberg Júnior Hugo da Costa , Teixeira Tâmara Porfíro , Bastos Luan Ferreira , Machado Alessandra Silveira , Oliveira Davi Ferreira , Dos Reis Sérgio Furtado , Lopes Ricardo Tadeu
Published: April 2021

Brazilian Rainforest is the habitat of many species of the genus Brachycephalus, among them is the pumpkin toadlet, Brachycephalus ephippium. X-ray microcomputed tomography is a nondestructive imaging technique which allows the visualization and analysis of internal microstructures of various samples, and has been applied on the study of these animals, enabling thorough description and characterization of new species. Brachycephalus ephippium is of particular interest for it was the first Brachycephalus species to be discovered, which makes it a common interspecies comparative basis. Cranial morphological landmarks used in biological research are very small (0.1-1mm), hence the effects of voxel size on microCT images can be relevant, and this is what was investigated in this work. Effects of reconstruction voxel size were evaluated in both visual and quantitative perspectives, which showed that an intermediary voxel size could be chosen on similar microCT applications without significant loss of information, but with great processing and storage gain, optimizing the application of the technique in such works.
Appreciation of influence of acquisition parameters in analysis of root canal using microCT system
Authors: Bastos Luan Ferreira , De Araújo Olga Maria Oliveira , Dos Santos Caio Márcio Sorrentino de Freitas Farias , Teixeira Tâmara Porfíro , Funcke Renata Périssé Nobili , De Lima João Carlos Rocha , Machado Alessandra Silveira , Oliveira Davi Ferreira , Lopes Ricardo Tadeu
Published: April 2021

Microtomography is successfully used in the odontological evaluation and treatments, as it´s capable to analyze the bone tissue and any possible damage in its root canal caused by a surgical intervention. In this study, the microCT was used to analyze the images by using different parameters in the acquisition process, as two matrix sizes: 1120x1120 pixels and 2240x2240 pixels. After the reconstruction, the volume of the root canal was analyzed, as well as the quantification of a remaining tooth closure material. The results showed that the detector array 1120X1120 was able to capture values close to those of the 2240x2240 matrix for the volume of root canal and for the residual material after treatment. Remaining tooth closure material correspond an average of 0.95 mm³ for 1120x1120 pixels, while the corresponding volume for 2240x2240 pixels was 0.90 mm³. Results for root canal volume average was 10.32 mm³ for 1120x1120 pixels, while for 2240x2240 pixels was 10.22 mm³. In this way, the difference of the detected volume between the two matrices is of 5.47% for the residual material and 0.93% for root canal volume. In a qualitative analyze, the 2240x2240 matrix allows the identification of a greater amount of details. However, it was possible to verify that depending on the application and the region of interest studied the smaller matrix can offer reliable results and a shorter processing time.
Elementary characterization of metals in lipsticks by EDXRF
Authors: Montenegro Peddis Torres Catarina Alzira , Paschuk Sergei Anatolyevich , Narloch Danielle Cristine , Corrêa Janine Nicolosi
Published: April 2021

Usually classified as cosmetic consumer products, makeups usually contain significant quantities of colorants, which may contain toxic and heavy metals, such as Hg, Cd, As, Cr, Tl, and Pb. According the Health Regulatory Agency (ANVISA), lipsticks are classified as low health risk, grade 1. However, similar makeups for the children are classified as grade 2, high risk, and within this category there is no cosmetic product for embellishment. Many metals, present in the colorants, can cross the mucous membranes and skin barrier and could be absorbed into the blood system, which can cause systemic damage to internal organs. Many chemical components present in the lipsticks, such as Al, Pb, Cd, Br, Cu, Zr, Cr, Hg, TiO2 in nanoparticulate form, could be considered as potentially toxic. Present work was undertaken in order to study the presence of mentioned above metals in the samples of commercial lipsticks. The metals characterization and elementary identification was performed using EDXRF technique. This method allows to perform the qualitative and quantitative analysis by means of the characteristic X-rays spectra emitted by the elements present in studied samples. The experimental setup was based on mini X-ray tube with Ag target and detector (AMPTEK). The partial results of the study revealed that the lipstick samples revealed the presence of Mg, Al, Si, P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Zn, Br, Rb, which suggest that prolonged and constant use of such cosmetics may constitute a potential threat to the health especially in the case of children.
Oxide layer characterization by XRD and Rietveld refinements in maraging steel 300 aged in steam atmosphere
Authors: Silva Vanessa Sanches Pereira da , Neto José Roberto Ferreira , Silva Silvia Lucas Ferreira da , Oliveira Diogo Costa de , Camargo Fábio de
Published: April 2021

Maraging steels are martensitic steels hardened by precipitation of intermetallic compounds in thermal aging, with good machining properties and high strength, fracture toughness and corrosion resistance, being used in aircraft parts and rocket motor-case, tooling applications and nuclear plants. During thermal aging in steam atmosphere a protective and corrosion resistant oxide layer is formed over the bulk. In this work, conventional Bragg-Brentano geometry was used to identify the phases formed in four specimens of maraging steel grade 300 with different surface finishes that were previously solution annealed twice at (950 ± 5) °C for 1 h, air-cooled, and submitted to oxidation process under positive pressure about 1.5 kPa of steam at (480 ± 5) °C for 6 h, followed by forced air-cooling. Diffraction patterns were measured employing CuKα radiation, ranging 20º < 2θ < 85º and the Rietveld method was used to better characterize the structures identified. Through Rietveld refinements it was possible to conclude that the layer formed during heat treatment process is constituted by a transition metallic phase with a quasi-cubic face centered unit cell, and an oxide layer that includes hematite, magnetite and a spinel structure type MFe2O4, where M could be an alloying element, for all analyzed samples.
Characterization of bi-layers formed over maraging steel 300 during aging process with steam atmosphere by GIXRD and SEM
Authors: Silva Vanessa Sanches Pereira da , Neto José Roberto Ferreira , Silva Silvia Lucas Ferreira da , Oliveira Diogo Costa de , Camargo Fábio de
Published: April 2021

Maraging steels are martensitic steels hardened by precipitation during thermal aging, with good machining properties and high strength and corrosion resistance. It is well suited for applications which require high strength-to-weight material, being used in aerospace, aeronautics and nuclear industries. A protective and corrosion resistant oxide layer can be formed during age hardening if treated in steam atmosphere. This work aims to use grazing incidence X-ray diffraction (GIXRD) to evaluate qualitatively the thickness of the layers formed during this process. GIXRD and scanning electron microscopy (SEM) were employed to identify and order the layered structure formed on four specimens of maraging steel grade 300 with different surface finishes that were previously solution annealed twice at (950 ± 5) °C for 1 h, air-cooled, and submitted to oxidation process under positive pressure around 1.5 kPa of steam at (480 ± 5) °C for 6 h followed by forced air cooling. The diffraction patterns were measured employing CuKα radiation and parallel beam, in step scan mode, using incident angles varying from 0.2º to 4.0º and 20º < 2θ < 85º. The results revealed the formation of two layers, the innermost was formed by γ-iron (austenite – fcc) phase followed by a mixture of oxides (hematite and magnetite) on the top, regardless of surface finish, which was confirmed by the SEM analysis that also allowed the measurement of the average layer’s thickness of oxides (1.130 ± 0.094) µm and austenite (0.507 ± 0.090) µm phases, and corroborated the qualitative thicknesses analysis made from GIXRD results.
Determination of chemical elements in magnesium-based materials by neutron activation analysis
Authors: Silva Caio Almeida Justino , Braguin Lilian Ninoska Muriel , Rossi Jesualdo Luiz , Costa Isolda , Saiki Mitiko
Published: April 2021

Over the last decades there was an increasing interest in using magnesium alloys for medical applications due to their biodegradability in the human body, providing a temporary mechanical support and corroding completely after the tissue healing. Although magnesium is a non-toxic element, it is of great importance to evaluate the element concentration, as well as the impurities present in both, pure magnesium and magnesium alloys, as the AZ31. The purpose of this study was to analyze the element composition of these materials using the method of neutron activation analysis (NAA). Standard Reference Materials (SRMs) acquired from National Institute of Standards and Technology (NIST) were analyzed for analytical quality control. Short and long term irradiations were carried out at the IEA-R1 nuclear research reactor and gamma-ray activities induced to the samples and element standard were measured using HPGe detector coupled to a Digital Spectrum Analyzer. The radioisotopes were identified by gamma ray energies and half-life. Concentrations of the elements As, Cr, Cd, Co, Fe, In, La, Mg, Mn, Mo, Na, Sb, V, W and Zn were determined in pure magnesium sample and the Al, As, La, Mg, Mn, Na, Sb and Zn in the AZ31 alloy, calculated by comparative method. The SRMs were analyzed by applying the same experimental conditions used for magnesium-based materials and their results presented good accuracy and precision. Thus, from the measurements obtained in this study it can be concluded that NAA is a suitable method for element determinations in magnesium-based materials providing reliable results.
Characterization of the petrology of the tar sandstone rock of the Paraná basin
Authors: Amadeu Rafael de Aquino , Bernardes Thiago Lynyker da Silva , Santos Rodrigo Sousa , Garcia Rafael Henrique  L. , Velo Alexandre França , Cavallaro Francisco Assis , Mesquita Carlos Henrique , Hamada Margarida Mizue
Published: April 2021

In the state of São Paulo (Brazil), occurrences of tar sandstone are known in Botucatu, Angatuba, Pirambóia, Anhembi and Bofete municipalities. In the present work a sample of white tar sandstone was taken from Anhembi municipality, located at Km 168 of the Castelo Branco Highway. In the petroleum area, sandstones act as excellent hydrocarbon reservoirs, since they have specific characteristics, such as: high porosity and permeability. Porosity is a property of rocks, and it may be understood as the voids contained in the matrix (where fluids remain stored), while permeability is the ability of the rock to transmit these stored fluids. Due to these characteristics of sandstones, researchers have shown a growing interest in the study and characterization of this type of rock, which is a fundamental element of an oil system. In the present work, four characterization techniques were used in the Anhembi tar sandstone sample, namely: X-ray Diffraction (XRD), X-ray Fluorescence (XRF), Scanning Electron Microscope (SEM) and the third generation Industrial Computerized Tomography. Through these techniques, the chemical composition, grain morphology, crystalline structure phases and an image of a slice of the internal structure of the white tar sandstone sample were obtained.
Aналогії між класичною задачею про коливання двох зв’язаних тіл і некласичною задачею про поширення плоских хвиль у двофазній суміші
Authors: Рущицький Я.Я.
Published: April 2021

З метою виявлення аналогій в процедурах аналізу описано та прокоментовано дві задачі: класичну задачу(задачу К) про гармонічні коливання двох зв’язаних між собою абсолютно твердих тіл, підвішених на пру-жинах, і некласичну задачу (задачу Х) про поширення плоских поздовжніх хвиль у двофазній пружній сумішіПобудовано ряд аналогій між цими задачами, які описані у вигляді шести кроків порівняльного аналізу задачК та Х, кожен з яких відповідає певній конкретній аналогії. Акцентовано увагу на корисність спостере-жених аналогій для аналізу задачі про хвилі. Отже, показано, що теорія двофазних сумішей у своєму роз-витку в області теорії хвиль може успішно використовувати аналогії з відповідних задач теорії коливаньдвох взаємозв’язаних коливних систем. З наведених аналогій випливає більш загальний факт, що виявлениймай же 100 років тому академіком Мандельштамом, механізм взаємодопомоги в теорії коливань за цей часрозширив свій вплив і на теорію хвиль.
Класи проєктивних представлень у визначенні симетрії колективних спінорних збуджень та їхньої дисперсії в кристалах і періодичних наноструктурах
Authors: Булавін Л. А. , Губанов В.О. , Науменко А.П.
Published: April 2021

Розглянуто розподіл електронних елементарних збуджень у кристалах і періодичних наноструктурах за незвідними проєктивними представленнями відповідних проєктивних класів точкових і просторових груп симетрії та залежність проєктивних класів від структури нетривіальних трансляцій просторових груп. Головну увагу приділено встановленню двозначних незвідних проєктивних представлень і відповідних їм про- єктивних класів з урахуванням спіну електрона, коли хвильовими функціями електронних станів є двоезначні спінорні орбіталі. Описано методики побудови фактор-систем, проєктивно еквівалентних (p-екві ва- лентних) фактор-систем, притаманних певному проєктивному класу проєктивних представлень, та ме тодики зведення їх до р-еквівалентного стандартного вигляду. Запропоновано нову класифікацію проєк- тивних класів для гексагональних структур, а також побудовано коректну таблицю симетрійних перет- ворень спінорів. Показано, що встановлення проєктивних класів проєктивних представлень і їх змін для різних точок зон Бріллюена в кристалічному графіті ɣ-C і двоперіодичній структурі одношарового гра фену CL1 дає можливість надати якісну симетрійну інтерпретацію дисперсії електронних збуджень у крис- талічному графіті і одношаровому графені. Зокрема, це дає змогу виявити спінзалежні розщеплення елект- ронних станів у їх зонах Бріллюена, які обумовлені спін-орбітальною взаємодією в спінорних орбіталях.
Кліматичні зміни та водні ресурси басейну Десни до середини ХХІ століття
Authors: Осипов В.В. , Осадча Н.М. , Осадчий В.І.
Published: April 2021

Наведено проєкції зміни температури, опадів, евапотранспірації, запасів вологи ґрунту, компонентів водного стоку та витрат води у водотоках басейну річки Десна в період 2021—2050 рр. відносно 1991—2020 рр. Розрахунки виконано засобами процес-орієнтовної моделі SWAT (Soil and Water Assessment Tool). Прогнозні метеорологічні параметри (щоденні температура повітря, опади, швидкість вітру, вологість повітря, сонячна радіація) отримано за результатами регіональних кліматичних моделей (РКМ) проєкту Euro– CORDEX. Загалом ансамбль містить шість РКМ, які перевірено на спроможність відтворювати річний розподіл температури та опадів за базовий період (1970—2005 рр.). Для майбутнього періоду розглянуто два сценарії викидів парникових газів та аерозолей — RCP4.5 та RCP8.5. Більшість моделей свідчить про те, що на фоні 5—10 %-го зростання опадів взимку та навесні річні витрати води збільшаться на 5—33 % переважно завдяки зростанню об’єму ґрунтового живлення. Зрос- тає ймовірність посух, на що за результатами трьох із шести РКМ вказує зменшення на 10–20 % запасів вологи в ґрунті влітку. Результати дослідження мають вагоме значення для складання плану управління басейном річки Дніпро. Особливу уваги варто приділити адаптаційним заходам у сільському господарстві через можливий дефіцит вологи для розвитку рослин.
КАРТОГРАФУВАННЯ ГЕНОЦИДУ РОМІВ УКРАЇНИ (1941–1944 РР.) ТА ПАМ’ЯТІ ПРО ЦЕ
Authors: Тяглий Михайло
Published: April 2021

Упродовж низки проєктів, що їх останніми роками виконував Український центр вивчення історії Голокосту, було виявлено різноманітні історичні джерела, які загалом містять відомості про понад 140 місць загибелі ромів у зонах німецької окупації України. У цій статті подано п’ять карт, які є результатом пошукової роботи й заповнюють наявні на сьогодні у картографії та історіографії пробіли, дають змогу дати відповіді на такі запитання, що є нагальними при описі долі ромського населення України: 1) кількість і розташування місць страт ромів (що важливо для усвідомлення масштабу, регіональних особливостей і статистичних аспектів геноциду ромів на теренах України); 2) розподіл між кочовими та осілими ромськими жертвами за наявними джерелами (що важливо з огляду на концептуальні дискусії в історіографії щодо засад нацистської «циганської» політики, адже переважання жертв, які були осілими, переконливо демонструє, що у мотивації виконавців злочинів расово-ідеологічні чинники превалювали над уявленнями про «асоціальність» окремих ромів); 3) розподіл між німецькими виконавцями та місцевими співучасниками у злочинах щодо ромів (що важливо у контексті питання про ставлення місцевого населення до переслідуваних ромів та ступінь ініціативи місцевих органів врядування і допоміжної поліції у геноцидних акціях); 4) установа, яка задокументувала злочин (що важливо з погляду політики держави щодо документування злочинів проти ромів – зокрема, їхньої повноти та репрезентативності, – та особливостей формування суспільних уявлень про це); 5) наявність меморіальних об’єктів на місцях загибелі ромських жертв або зазначення наявності ромів серед жертв (що важливо у контексті формування соціальної пам’яті про геноцид ромів та наявності/відсутності механізмів «культурної пам’яті», що покликані увічнити пам’ять жертв). До кожної карти наведено опис методики її складання та аналіз наукової ваги поданих на ній відомостей. Узяті разом або окремо, карти мають потенціал для використання у науковій, освітній та музейній діяльності.
БЕРДИЧІВ ЯК ЦЕНТР ЗБУТУ ФАЛЬШИВИХ ГРОШЕЙ У РОСІЙСЬКІЙ ІМПЕРІЇ
Authors: Бойко-Гагарін Андрій
Published: April 2021

Проблема фальшивомонетництва є досить багатогранною, адже йшлося про задум, мотив, пошук зловмисниками сировини та ресурсів, виготовлення підробок грошей і зрештою збут готової продукції. Збут фальшивих грошей зазвичай відбувався у великих торгових містах і на ярмарках. У цій статті наведено та проаналізовано свідчення про виявлення фальшивих грошей у місті Бердичеві, що збереглися у справах з історичних архівів, повідомленнях газет і в опублікованих попередниками працях.

Проаналізувавши низку матеріалів карних справ із державних історичних архівів і публікації газет, ми отримали численні свідчення, що характеризують місто Бердичів як один із великих центрів збуту фальшивих грошей, починаючи із першої чверті ХІХ ст. і упродовж наступних ста років. Перша згадка про збут фальшивих асигнацій у Бердичеві стосується активності відомого фальшивомонетника Ігнація Цейзика, який розгорнув масштабну злочинну діяльність у різних регіонах Російської імперії, не припинивши незаконне виготовлення грошей навіть після затримання та ув’язнення. Сильні позиції на грошовому ринку Київської та Волинської губерній займали монети, карбовані від імені російського уряду для Царства Польського на монетному дворі у Варшаві. Поширеність і популярність цих монет призвели до виникнення їх підробок, масові виявлення спроб збуту яких у Бердичіві та Бродах спонукали владу Австрійської імперії до заборони обміну в касах банків російських грошей. Як важливий торговий центр Бердичів став також привабливим місцем для збуту фальсифікатів грошей, що їх упродовж майже всього ХІХ ст. завозили з Лондона. Збут підробок здійснювали з ініціативи учасників польського повстання 1831 р. через налагоджену мережу впливових євреїв- банкірів. У другій половині ХІХ ст. Бердичів привабив не лише збувальників фальшивих грошей, а і їх виробників. Затриманий у 1860 р. у Сквирському районі збувальник фальшивих 25-рублевих кредитних білетів на допиті сказав, що їх виготовлено у таємній майстерні у Бердичіві. Ввезення до міста з метою збуту фальшивих грошей могло відбуватися і на початку ХХ ст., зокрема окрім підроблених кредитних білетів правоохоронці вилучали також фальсифікати поштових марок, про що повідомляють газети Бердичева.
Адаптація комунальної теплоенергетики до змін клімату
Authors: Басок Борис Іванович , Базєєв Євген Трифонович , Кураєва Ірина Володимирівна
Published: April 2021

Помітний тренд підвищення глобальної температури, зафіксований з середини ХХ ст., який особливо посилився на початку ХХI ст., змусив наукове співтовариство розпочати активне обговорення можливих шляхів подальшого розвитку ситуації з глобальним потеплінням, її наслідків та проблем, пов’язаних з адаптацією до змін клімату. Проблема адаптації до глобального потепління стосується різних галузей економіки і сфер життєдіяльності людини, зокрема й комунальної енергетики. Тому в установах Відділення фізико-технічних проблем енергетики НАН України створено інноваційні енергоефективні технології, орієнтовані на пом’якшення наслідків змін клімату, в тому числі й з використанням відновлюваних джерел енергії, а також розроблено обладнання для інженерних систем енергозабезпечення будівель житлово-комунальної сфери. Оптимізовано архітектурно-будівельні рішення, що дозволяє знизити обсяги використання енергоресурсів і тим самим зменшити викиди парникових газів.
Management of Pediatric Nonpathogenic Blood Cultures After Introduction of PCR Technology
Authors: Hughes Julianne , Barone Stephen
Published: April 2021

BACKGROUND:

The rapid identification of organisms reported in positive blood cultures via polymerase chain reaction (PCR) can accurately identify a nonpathogenic bacterium and decrease time to definitive identification, as compared with traditional microbiologic methods. How this technology effects clinical and antimicrobial management in children with nonpathogenic bacteria identified in a blood culture without decision support has not been evaluated.

METHODS:

A retrospective study of the management of children with positive blood culture results for nonpathogenic organisms before and after implementation of PCR technology. Each cohort’s antibiotic management, frequency of repeat cultures, and return visits to an emergency department (ED) were compared.

RESULTS:

A total 136 patients during this time (49% [n = 67] pre-PCR and 51% [n = 69] post-PCR) had a blood culture positive for nonpathogenic bacterium. Admitted patients had a second specimen sent for testing on fewer occasions (P = .04); however, total antibiotic exposure did not differ significantly (P = .3) after introduction of PCR technology. There was no significant difference in length of stay postintervention (P = .12). Patients discharged directly from the ED had fewer return visits (P = .02) and received fewer repeat blood cultures (P = .04), and antibiotics were administered on fewer occasions after return (P = .04) postintroduction of PCR technology.

CONCLUSIONS:

With the addition of PCR technology, patients with blood cultures positive for nonpathogenic bacteria received less antibiotics, fewer repeat blood cultures, and fewer repeat ED evaluations.
First report of Atherigona reversura Villeneuve, 1936 (Diptera, Muscidae) in Uruguay
Authors: Remedios-De León Mónica , Patitucci Luciano Damián , Morelli Enrique
Published: April 2021

We present the first record of Atherigona reversura Villeneuve, 1936 in Uruguay, from Pando, Canelones department a rural area used for livestock. Atherigona reversura, this muscid, commonly known as shoot-fly, is a significant pest of cereal crops throughout the Old World tropics and subtropics and its main host is Bermudagrass, Cynodon dactylon L.Pers., an exotic species which is widely distributed in South America and in Uruguay and has economic value as forage for livestock and is damaged by the feeding of A. reversura larvae.
CONCEPTUAL DESIGN OF THE WING OR FUSELAGE STRUCTURE OF A MAINLINE AIRCRAFT MADE OF METAL-POLYMER COMPOSITE MATERIALS
Authors:   Moscow Aviation Institute (National Research University), Pechenyuk Valery , Popov Yuri ,   Moscow Aviation Institute (National Research University)
Published: April 2021

The analysis of existing aircraft structures made of metal-polymer composite materials is carried out, and a list of them with passport characteristics is compiled. The Fokker F-27 Friendship, Boeing-777 and Airbus A380, which use ARALL and GLARE materials, were selected as the aircraft under study. Formulas are determined and the distribution of normal force flows between metal and composite elements in the composition of MPCM based on aluminum sheets (aluminum-fiberglass – SIAL- 1-1, SIAL-3-1 and SIAL-1441 (9/8)) and titanium alloys (samples of titanium-carbon fiber from the patent-Example 1 and Example 3). To determine these parameters, the formulas used for a composite structure made of different materials are used. On the basis of the specification known MPCM the modified formula mixture rule for calculating the strength of new materials with a given set of orientation angles of PCM and the presence of layers of sheet metal, a comparison with standard mechanical characteristics and to show the efficiency of these formulas. Using these formulas, you can determine the strength characteristics for an arbitrary composition of the MPCM package. The features of the choice of design permissible stresses for the design of the airframe of a mainline aircraft made of metal-polymer composite material are highlighted. The concept of designing aircraft airframe elements using MPCM is considered. The results of this work will allow us to determine the rational components of the metal-polymer composite material and the structure of their distribution in the airframe design at the preliminary design stage.
NUMERICAL STUDY OF DYNAMICS INTRACHAMBER PROCESSES IN SOLID PROPELLANT SUSTAINER TAKING INTO ACCOUNT FLIGHT OVERLOADS. PART 1. CALCULATION METHOD
Authors:   Perm National Research Polytechnic University, Egorov Mikhail , Egorov Dmitry ,   JSC "Scientific-Research Institute of Polymeric Materials", Egorov Sergey ,   JSC "Scientific-Research Institute of Polymeric Materials"
Published: April 2021

The dynamics of transient in-chamber processes (internal ballistics) of the cruise missile's second-stage cruise missile propulsion system is studied, taking into account, in the general case, distributed spatially-three-dimensional and time-varying flight overloads. The research method is the formulation of a computational experiment. Be considered coupled formulation of the problem, including: – transient triggering of igniter device (the rate of combustion of the igniting composition is described on the basis of experimental and theoretical approach afterburn combustion products in case igniting device); preheating, ignition and subsequent unsteady and turbulent combustion of solid propellant charge (used quasi-homogeneous combustion model based on the equations of heat conduction and chemical kinetics recorded for a condensed phase (solid fuel), taking into account the influence of the gas phase (torch) on the process of combustion in the condensed phase; the method of solving the problem – finite difference method); – non-stationary three-dimensional homogeneous-heterogeneous four phase flow of air and products of combustion in the combustion chamber, the nozzle block and the block launchers rocket engine (used approaches of continuum mechanics of multiphase media; the basic system of equations system of vortex differential equations of gas dynamics solution method – a multi-parameter class of difference schemes of splitting into physical processes of the method Davydova); – depressurization of the combustion chamber of the SRB (equation of motion of the plug nozzle block – Newton's second law; the proposed solution method – Euler's method). Each of the subtasks is considered in a relationship and resolved simultaneously – at one time step. To solve the formulated problem, a set of application programs has been developed using (for the main calculation module) the OpenCL multithreaded information processing standard. The performance of the software product was checked.
Temporal and spatial variations of organochlorine pesticides (OCPs) and phthalates affecting the quality of water and sediment from Loskop Dam, South Africa
Authors: Mathapelo P Seopela  , Robert I McCrindle  , Sandra Combrinck  , Wilma Augustyn
Published: April 2021

Organochlorine pesticides (OCPs) and phthalates are amongst the most emphasized man-made environmental contaminants, due to their prevalence, persistence and potential to induce adverse effects in organisms. In addition to prevailing industrial and domestic activities, their presence in the environment is exacerbated by leaching from associated materials, run-off and emissions. The Loskop Dam in the Mpumalanga Province, South Africa, is located on the Olifants River, which flows through a hub of industrial and agricultural activities. Research aimed at monitoring the levels of OCPs and phthalate contamination in South Africa, particularly in the Olifants catchment, has been limited and is restricted to short-term monitoring. In this study, the spatial and temporal variations of 21 OCPs and 7 phthalates in water and sediments from Loskop Dam were evaluated over a 3-year period (2015–2017). Annual average OCP levels ranged from 0.013±0.006 to 0.36±0.13 μg/L in water and from below the limit of detection to 2.4±1.2 µg/kg in sediments. Phthalates were present at average concentrations ranging from 0.023±0.041 to 2.1±1.5 μg/L and 20±0.63 to 55±6.9 µg/kg in water and sediments, respectively. The levels of OCPs and phthalates were greatest in autumn, attributed to higher input sources and concentration effects due to lower water levels. Phthalates were present at greater quantities at the inlet, while OCP accumulation was observed at the upper reaches of the dam. This may be an indication of the differences in input sources and translocation of these compounds, related to the topography of the dam and variability in water flow rates. These findings are important in highlighting the environmental and health concerns that may arise in the Olifants catchment area. After considering the outcomes of this study, we propose the implementation of regular and stringent monitoring strategies, which include surveys of OCPs and phthalates for Loskop Dam and similar water systems globally.
Fabrication of smartphone-based colorimetric device for detection of water leaks
Authors: Zodidi Gcolotela  , Stanley Chibuzor Onwubu  , Sindisiwe Fortunate Muthwa  , Phumlane Selby Mdluli
Published: April 2021

South Africa is a water-scarce country due to the shortage of rainfall.  This scarcity is further exacerbated by the loss of water through leakage from faulty pipes. This paper reports on the use of a simple microfluidic device in the early detection of water leakages. The microfluidic paper-based device (µPADs) were prepared by printing patterns of wax (100 μm width) on the paper surface and melting the wax into the paper to form hydrophobic barriers. Solutions of lower to higher pH were also prepared and were introduced to the chlorophenol red test strips and a range of colours from yellow (lower pH) to purple (higher pH) were obtained. The digital images obtained with the μPADs were analysed using the CIELab colour system. The optimized pH range was wider than the typical grayscale-based image analysis and was successful for a wide pH range of 2–12. The QR codes attached to the strips enable tracking to obtain the real-time location from which leakage was detected. The study conclusively shows that the combination of digital image analysis and a μPAD device is highly efficient for quantitative analysis, and thus useful for the detection of household water leaks.
Comparative analysis of methods for constructing analog-to-digital converters
Authors:   Novosibirsk State Technical University, Russian Federation, Ulyashin Aleksander , Velichko Aleksander ,   Novosibirsk State Technical University, Russian Federation
Published: April 2021

This paper is devoted to the comparative analysis of modern integrated analog-to-digital converters (ADCs). At the moment, a number of foreign companies, such as Analog Devices, Texas Instruments and Microchip, produce ADCs in integrated design. Each manufacturer uses its own method of implementing the device. The main task of such devices is to convert voltage to binary code. ADCs are used wherever it is necessary to receive an analog signal and process it in digital form. Examples include applications such as communications and telecommunications, various radio systems, and measurement technology. Very important characteristics of such equipment are dynamic range, ease of implementation and speed. The means of analog-to-digital conversion are constantly being improved, which leads to an increase in the speed of the converters and the frequency band of the converted signals, an increase in the dynamic range, sensitivity and accuracy of the ADC. Significant interest in high-speed ADCs with a large dynamic range is explained by the fact that in the vast majority of telecommunications and radio engineering systems, direct signal conversion schemes without intermediate frequency conversion are increasingly used. Broadband applications have also been developed. The main requirement in these applications is the high sensitivity and wide dynamic range of the transducer for simultaneous detection of strong and weak signals. In this paper, a comparative analysis of the main types of analog-to-digital converters offered on the market is carried out in order to identify the most optimal construction method for using it in modern equipment.
Example of polynomial controller synthesis for a non-square object with one input and two outputs
Authors:   Novosibirsk State Technical University, Russian Federation, Voevoda Aleksander , Shipagin Victor ,   Novosibirsk State Technical University, Russian Federation
Published: April 2021

Polynomial methods for synthesizing controllers for automatic control systems with linear objects are becoming increasingly common. The synthesis of multichannel controllers is particularly difficult, which is caused by the need to use matrix polynomial calculus. However, this approach mainly considers objects with the number of inputs equal to the number of outputs. This is due to the convenience of solving a system of linear algebraic equations in matrix polynomial calculus. In this paper, we consider a polynomial method for synthesizing regulators for a non-square object, that is, one whose number of inputs is not equal to the number of outputs. The selected system contains not only a non-square object, but also a non-square controller.
El poder normativo de España en la constitución de la comunidad iberoamericana
Authors: Castillo Alberto , Gil-Barragán Juan Manuel
Published: April 2021

El siguiente trabajo tiene como objetivo reflexionar sobre la constitución de la comunidad Iberoamérica a partir de la formación de España como potencia normativa, en donde, la cooperación internacional para el desarrollo como expresión de la política exterior española permite dilucidar su focalización estratégica. Para alcanzar este objetivo el artículo aborda desde la teoría socialconstructivista la conformación de las identidades, valores y normas. A partir de este enfoque se analiza la construcción de la comunidad iberoamericana por medio de las Cumbres Iberoamericanas y la cooperación internacional para el desarrollo que, como instrumento de la política exterior española, ha permitido distinguir cinco etapas en la conformación de la comunidad iberoamericana.
Human Islet Quantification and Purity Assessment v2
Authors: Lyon James , F Spigelman Aliya , E Manning Fox Jocelyn , E Macdonald Patrick
Published: April 2021

This protocol describes the Quantification and Purity of Assessment of human islets, as performed by the Alberta Diabetes Institute IsletCore. www.bcell.org/adi-isletcore
Evolvement of interpretation capacities of seismic measurements in mining of water-soluble minerals
Authors: Sanfirov I. A. , Zhikin A. A. , Fatkin K. B. , Bogdanov R. A.
Published: April 2021

The current development level of geophysical methods for mining monitoring of water-soluble mineral deposits provides opportunities to control the growing variety of potentially hazardous geological and mining conditions, to identify the critical states of rock mass and to monitor the emergency facilities. Seismic surveys for solving the specified problems have proven to be a highly informative method for studying the structural features and properties of productive and waterprotective overburden strata, which has a high information richness of the recorded data. The main set of parameters for the interpretation stage of seismic exploration has been formed based on the experience in shallow seismic surveys within a potash deposit; it incl udes the target reflection times, effective and interval velocities, amplitudes, frequencies and a number of derivatives from these parameters. Improvement and adaptation of world interpretation practices in relation to the indicated seismic studies conditions provides means for increasing reliability of anomalies identification and expanding the set of typical wave ‘images’ for various kinds of inhomogeneities in a wide range of wave field realizations and its attributes. The analysis of irregular wave field component in the results of scattered waves processing, spectral decomposition and RGB-mixing is considered as an additional techniques of qualitative interpretation. An approach is proposed to determining possible fracturing in rock mass based on the variability of interval velocities. In combination with the AVO-analysis, this approach makes it possible to assess the trend of rock disintegration within the emergency facilities. The interpretation results of the areal (quasi-3D) and spatial (3D) detailed surveys of a shallow potash deposit are presented.
Unit weight patterns of overlying rocks above commercial-value salt strata in the Upper Kama deposit
Authors: Chernopazov D. S. , Shkuratskiy D. N. , Sekuntsov A. I.
Published: April 2021

Stability of rocks is the main requirement for the safe operation of mines. For this purpose, certain measures are applied for the protection and support of underground openings, including roof support design and roof arrangement in the most stable rocks. Stability assessment of underground excavations is largely related to their roof stability. Determination of possible instability conditions in mine roofs governs the choice of support system design and parameters of mine excavations. The Upper Kama Potash Salt Deposit represents a stratified layer of solid salt rocks. Roof instability develops as stratification and roof collapse. The Mohr–Coulomb criterion of coherent rocks is currently used to estimate parameters of a possible damage zone in the exposed roof. This criterion allows evaluating shear plane angles in roof rocks and, as a result, finding parameters of the possible collapse zone. The experience of mining operations in the Upper Kama deposit shows different failure conditions as against the Mohr–Coulomb criterion as the stress state is scarcely included in the criterion used. This study is an attempt to assess parameters of rock exposures by solving a Lame problem in terms of a single mine excavation. The analytical results were compared with the parameters obtained from the plane elasticity solutions by the finite element method. Based on the implemented studies, an engineering approach is developed for the assessment of anticipated instability parameters in exposed roofs in horizontal excavations driven in salt rocks.
Application of information technologies in the analyses of groundwater in the Upper Kama Potash–Magnesium Salt Deposits
Authors: Sennov A. S. , Mukhametdinov A. V. , Myasichenko A. I. , Kalugin A. V.
Published: April 2021

The article gives a review of the software techniques used in solution of actual applied problems in the mining industry. The adequate decision-making requires various software techniques. The list of the applied problems includes processing of remote sensing data, digital elevation modeling and generation of other digital models of terrain, localization of catchment basins and river networks, or morphometric analysis. Various geoinformation systems are used to this end. Another task is hydrogeological patterning of aquifers. It is required to use the methods of multivariate statistics, such as the factor analysis, for instance. The multidimensionality and complexity of natural and engineering systems also condition the use of the mathematical modeling apparatus based on the numerical solution of second-order elliptical equations in terms of partial derivatives. Natural water feature diverse physicochemical processes, which should also be calculated. The modeling outcome is used to predict different processes in the nature-and-mine system. For example, flow of pollutions in underground hydrosphere, lowering of the water level, dissolution–precipitation reactions, etc. Applied problem solving requires using wide ranges of mathematical methods and relevant software techniques.
Improving the quality of potash fertilizers
Authors: Fedulova G. P. , Buksha S. V. , Rogozin M. D. , Belyakova K. O.
Published: April 2021

Both domestic and international markets demand potash fertilizers with potassium chloride content not less than 95%, as well as with definite physical and mechanical properties. The flotation and halurgic methods of potassium chloride production ensure the required content of potassium chloride in the finished product. Thus far, the spotlight is on the wanted physical and mechanical properties of potash fertilizers, especially the export products under the conditions of high competition on the international market. The article presents the results of monitoring the physical and mechanical properties of fine-grained and granular potassium chloride exported by Uralkali. The factors that have the greatest impact on the commercial attractiveness of fertilizers to meet the international market demand are highlighted. The article studies the influence of various modifiers aimed to improve the physical and mechanical properties of potassium chloride and the agrochemical technology of fertilizer application. The quality of the final product should be closely related with the production technology of potassium chloride, its modification using different reagents, as well as with the conditions of haulage and warehousing of the finished product. The authors sincerely appreciate participation of Deputy Chief Technical Officer, Candidate of Engineering Sciences S. N. Aliferova and Head of Technical Control Department Yu. I. Moskvicheva, Uralkali, in the studies.