bluuebunny/crossref_metadata_2025 huggingface dataset:
The impact of trait number and correlation on functional diversity metrics in real-world ecosystems
Authors: Ohlert Timothy , Kimmel Kaitlin , Avolio Meghan , Chang Cynthia , Forrestel Elisabeth , Gerstner Benjamin P. , Hobbie Sarah E. , Reich Peter , Whitney Kenneth D. , Komatsu Kimberly
Published: September 2024

The use of trait-based approaches to understand ecological communities has increased in the past two decades because of their promise to preserve more information about community structure than taxonomic methods and their potential to connect community responses to subsequent effects of ecosystem functioning. Though trait-based approaches are a powerful tool for describing ecological communities, many important properties of commonly-used trait metrics remain unexamined. Previous work with simulated communities and trait distributions shows sensitivity of functional diversity measures to the number and correlation of traits used to calculate them, but these relationships have yet to be studied in actual plant communities with a realistic distribution of trait values, ecologically meaningful covariation of traits, and a realistic number of traits available for analysis. To address this gap, we used data from six grassland plant communities in Minnesota and New Mexico, USA to test how the number of traits and the correlation between traits used in the calculation of eight functional diversity indices impact the magnitude of functional diversity metrics in real plant communities. We found that most metrics were sensitive to the number of traits used to calculate them, but functional dispersion (FDis), kernel density estimation dispersion (KDE dispersion), and Rao’s quadratic entropy (Rao’s Q) maintained consistent rankings of communities across the range of trait numbers. Despite sensitivity of metrics to trait correlation, there was no consistent pattern between communities as to how metrics were affected by the correlation of traits used to calculate them. We recommend that future use of evenness metrics include sensitivity analyses to ensure results are robust to the number of traits used to calculate them. In addition, we recommend use of FDis, KDE dispersion, and Rao’s Q when ecologically applicable due to their ability to produce consistent rankings among communities across a range of the numbers of traits used to calculate them.
HIV and hepatitis C virus infection and co-infection among trans women in San Francisco, 2020
Authors: Chiu Izzy , Cano Damiana , Leathers Matisse , Turner Caitlin M. , Trujillo Dillon , Sicro Sofia , Arayasirikul Sean , Taylor Kelly D. , Wilson Erin C. , McFarland Willi
Published: September 2024

Background

Transgender women (hereafter “trans women”) face social marginalization, stigma, and discrimination and experience a high burden of HIV. More recently, trans women have been identified as having a high risk for hepatitis C (HCV) infection. The interaction between these two diseases and the risks for HIV/HCV co-infection among trans women are understudied.

Objective

To characterize epidemiological, behavioral, and socio-structural interactions between HIV and HCV infections among trans women.

Methods

This cross-sectional study examined data from a community-based survey of trans women in San Francisco recruited through respondent-driven sampling (RDS) in 2019/2020. Face-to-face interviews collected data on demographics, medical history, drug injection practices, sexual behavior, and socio-structural factors (e.g., poverty, housing insecurity, incarceration, social support). HIV and HCV antibodies were detected using oral fluid rapid tests and prior diagnosis and treatment were collected by self-report. Blood specimens were collected to confirm antibodies using ELISA. Multinomial logistic regression analysis characterized factors associated with HIV infection alone, HCV infection alone, and HIV/HCV co-infection compared to neither infection.

Results

Among 201 trans women recruited, HIV prevalence was 42.3%; HCV infection by history or current seroprevalence was 28.9%; evidence for both HIV and HCV infection was present for 18.9%. Two-thirds of trans women (67.2%) had been incarcerated; 30.8% had ever injected drugs. History of injection drug use and receiving emotional support from family were factors found in common for HIV infection, HCV infection, and HIV/HCV co-infection compared to no infection. Having a sexual partner who injects drugs was associated with HIV infection alone. Not lacking care due to cost and older age were associated with co-infection. Older age was also associated with HCV infection. Of trans women with HIV infection, 91.8% had accessed HIV care, whereas only 62% with HCV had accessed some form of care.

Conclusions

Our study found high levels of HIV, HCV, and HIV/HCV co-infection among trans women in San Francisco. We found common associations between HIV and HCV through injection practices and emotional support, but having a sexual partner who injects drugs was not associated with HCV infection alone or co-infection. We note a substantial gap in the treatment of HCV for trans women, including those in HIV care, that needs to be urgently addressed.
Reduction of misdiagnosis in urinary tract infections during pregnancy: The role of adjusted urine flow cytometry parameters
Authors: Liu Zhaojie , Liu Dan , Su Guangming , Yang Wei
Published: September 2024

Introduction

Urinary tract infections (UTIs) pose a significant health concern, particularly among pregnant women, for whom accurate diagnosis is essential. However, the use of Urine flow cytometry (UF) for detecting UTIs in this demographic often results in misdiagnosis. The objective of this study was to explore the reasons behind these diagnostic errors and to develop a strategy to minimize the rate of UTI misdiagnosis in pregnant women.

Material and methods

The study enrolled 1,200 women aged 18 to 40 years, categorized into pregnant and non-pregnant groups. UTIs were diagnosed using urine bacterial culture, microscopic examination, and UF, followed by statistical analysis to identify any discrepancies in diagnosis between the groups. Following the calibration of UF analyzer’s parameters, the most effective CR(WBC)-CW-FSC-P Gain setting for diagnosing UTIs in pregnant women through UF was ascertained by applying the Youden index.

Results

The clinical diagnosis rate of UTIs was significantly higher in pregnant women (40.91%) compared to non-pregnant women (20.26%). However, urine microscopy and bacterial culture showed no significant difference in the rates of UTIs between the two groups, suggesting a potential for misdiagnosis. The false-positive rate for WBCs detected by UF was 30.43%, and adjusting the CR(WBC)-CW-FSC-P Gain value of UF reduced the false-positive rate to 9.45%.

Conclusion

The incidence of UTIs in pregnant women may be overestimated because of the limitations inherent to UF. Adjusting the parameters of the UF analyzer, particularly the CR(WBC)-CW-FSC-P Gain value, can significantly reduce the rate of UTI misdiagnosis in pregnant women.
Assessing the reliability of a digital inclinometer app for measuring hip, knee, and ankle proprioception
Authors: Chirumbole Sophia G. , Teater Rachel H. , Bals Megan M. , Richie Daniel R. , Monfort Scott M. , Chaudhari Ajit M. W.
Published: September 2024

Proprioception can be defined as the ability of an individual to detect motion and position of the various joints in their bodies. Current tools for measuring proprioception lack consensus on their accuracy and validity; they also each have their own limitations, and, furthermore, present barriers to use for clinicians. We propose a new and reliable method for evaluating hip, knee, and ankle proprioception by utilizing a digital inclinometer app to measure joint position sense. The digital inclinometer app recorded the active joint position sense error after each of five trials for the hip and knee joint and ten trials for the ankle joint. To quantify the reliability of the digital inclinometer app, single-measurement and average-measurement intra-class correlation coefficients (ICC) along with the associated 95% confidence intervals (95% CI) were calculated for each joint’s position sense error across trials. Both the hip (ICC (2,k) = 0.849 (95% CI = [0.783–0.897])) and knee joint (ICC (2,k) = 0.837 (95% CI = [0.750–0.897])) were found to have moderate to good reliability when the middle three of five trials were analyzed. Unlike the hip and knee, moderate to good reliability for ankle proprioception (ICC (2,k) = 0.785 (95% CI = [0.539–0.893])) was only achieved with the middle eight of ten trials. The results of this study indicate that this digital inclinometer app is able to accurately record joint position sense at the hip, knee, and ankle when the appropriate number of trials are collected; thus, allowing this tool and methodology to be considered for use in both clinical and research environments to measure proprioception, and furthermore, quantify proprioceptive deficits.
The interplay between Helicobacter pylori infection and rs738409 PNPLA3 in metabolic dysfunction-associated steatotic liver disease
Authors: Maiorana Facundo , Neschuk Magali , Caronia María Virginia , Elizondo Karina , Robledo María Laura , Schneider Adolfo , Veron Georgina , Zapata Pedro Dario , Barreyro Fernando Javier
Published: September 2024

Background

Recent studies have suggested an association betweenH.pyloriand metabolic-disfunction associated fatty liver disease (MASLD). However, epidemiologic studies have yielded inconsistent results. We aim to evaluate the association ofH.pyloriand G-allele PNPLA3 in MASLD diagnosis, and markers of severity.

Methods

A multi-center cross-sectional study was conducted. A total 224 functional dyspepsia (FD) patients cohort who underwent gastroscopy was selected. Biochemical, clinical parameters, ultrasound, FIB-4 score, LSM by VCTE, gastric biopsies,H.pyloristatus, and rs738409 PNPLA3 were evaluated. A second retrospective cohort of 86 patients with biopsy-proven MASLD who underwent gastroscopy with gastric biopsies was analyzed.

Results

In the FD cohort MASLD was observed in 52%, andH.pylori-positive in 51%.H.pyloriinfection was associated with MASLD prevalence, but in multivariate analyses adjusted for G-allele PNPLA3, it became not significant. Then in MASLD-only dyspeptic cohort,H.pyloriinfection was significantly linked to elevated serum AST levels and increased liver stiffness measurements, suggesting a potential role in liver injury and fibrosis. Histopathological analysis in biopsy-proven MASLD patients further supported these findings, showing a significant association betweenH.pyloriinfection and increased NAS score, fibrosis stage, and prevalence of MASH. Notably, the combination ofH.pyloriinfection and G-allele PNPLA3 appeared to exacerbate MASLD severity beyond individual effects.

Conclusions

Our results suggest thatH.pyloriinfection may play a role in the progression of liver injury and fibrosis in patients with MASLD, especially in those with specific genetic predispositions.
Pausânias. Descrição da Grécia. Livro VIII
Authors: Silva Maria de Fátima
Published: September 2024

Pausânias é o nosso único testemunho de literatura periegética e o autor de um relato precioso sobre a Grécia da época de ocupação romana (séc. II d.C.). A sua descrição é a de alguém que viajou e sintetiza o que com um olhar que não é só o de um turista curioso, mas de um intelectual que dispõe de uma sólida formação cultural e de uma informação ampla, em resultado de uma recolha criteriosa de todo o tipo de fontes, orais e escritas. Para com Pausânias mantemos em aberto uma enorme dívida: a de ter salvado um lastro de monumentos, de acontecimentos históricos, de figuras e de tradições que, sem ele, se teriam em definitivo apagado da memória dos homens.
Experimental investigation on masonry structural joint repointing with cement-polymer mortar and polypropylene strips
Authors: Churilov Sergey , Dumova-Jovanoska Elena , Shendova Veronika , Krstevska Lidija , Damchevski Bojan , Janchev Dime
Published: September 2024

Unreinforced masonry structures are prevalent in urban areas. Many of these structures are vulnerable to earthquakes, which are the primary causes of damage and failure. Therefore, conducting comprehensive studies to assess the structural capacity of these buildings is crucial for understanding their behaviour and vulnerability and for proposing effective strengthening measures. This integrated experimental and numerical study explored the effectiveness of joint repointing as a viable method for strengthening masonry structures. A review of recent research on various joint repointing techniques and materials is presented in the first part of this paper. The experimental investigations of unreinforced and strengthened masonry panels, utilising cement-polymer mortar and polypropylene strips in bed joints subjected to compressive and diagonal compressive strengths, are detailed. The experimental results demonstrate that structural joint repointing significantly improves the strength and has a minor effect on the ductility of the masonry, particularly when the original mortar has low-strength properties, as expected in existing buildings. The obtained results enable the calibration of nonlinear numerical models and modelling strategies used to study the elements in a more extensive manner, allowing for parametric studies and the application of the findings to existing buildings.
Kinematic SSI effects on seismic performance of RC structures
Authors: Petrov Nikola , Bojadjieva Julijana , Bojadjiev Jordan
Published: September 2024

In seismic regions, understanding soil–structure interaction (SSI) is crucial. This study examines the SSI effects on a six-storey RC-frame building using American guidelines for soil types B and C as per Eurocode 8. Structural responses of a constant structural system under various soil types and embedment conditions are compared, revealing significant influences on seismic behaviour. The study employs linear-elastic analysis to demonstrate that local soil and embedment conditions decrease base shear forces but increase total horizontal displacements and inter-storey drifts. This study highlights the importance of considering local soil conditions and embedment configurations to ensure structural resilience in earthquake-prone areas.
Holistic sustainable buildings renovation: a case study from Switzerland
Authors: Koprivica Stefan , Golić Kosa , Kosorić Vesna
Published: September 2024

Renovation is a pivotal element in realising sustainability objectives in the construction industry, as established by the EU Commission. By analysing a real-life case study in Switzerland, this study provides insights into strategies and measures crucial not only for attaining an energy-efficient building state but also for achieving broader sustainability goals encompassing social and economic aspects. In addition, a general decision-making framework for residential building renovations is provided. The presented case study may serve as a role model for the successful sustainable renovation of other similar residential buildings and stimulate further research that facilitates effective holistic sustainable renovation.
„A külföldről beáramló termelési - technológiai, menedzseri tudásnak inspiráció helyett elkényelmesítő hatása lett” – Interjú Dr. Bélyácz Iván akadémikussal, a Pécsi Tudományegyetem Professor Emeritusával
Authors:   Világpolitika és Közgazdaságtan, Bélyácz Iván
Published: September 2024

A Világpolitika és Közgazdaságtan interjút kért Dr. Bélyácz Iván akadémikustól a hazai vállalati szektor beruházási aktivitásával kapcsolatos kérdésekben. Az interjú apropóját az a tény adta, hogy a magyar gazdaság teljesítményében a vállalati szektor ellentmondásos képet mutat. Alacsony a termelékenység növekedése, miközben a tudásalapú gazdaság követelményei egyre sürgetőbben jelentkeznek. Az interjúban rákérdeztünk arra, hogyan kellene segíteni a vállalatok alkalmazkodását.
„Az adóverseny a települések között valójában alig tud érvényesülni Magyarországon (...)"
Authors:   Világpolitika és Közgazdaságtan, Szebeni Dávid
Published: September 2024

Az adópolitika kulcsszerepet játszik a térségfejlesztésben, mivel közvetlenül befolyásolja a helyi önkormányzatok pénzügyi lehetőségeit, a gazdasági növekedést és a lakosság életminőségét. A települések által választott adópolitikai eszközök a központi kormányzat által nyújtott keretek között mozogva érzékeny egyensúly mentén kell ösztönözniük a térség vállalkozói szellemiségét és gazdasági növekedését, miközben komoly forrást kell biztosítaniuk a helyi érdekű fejlesztések megvalósításához is. Ezen egyensúlykeresésről és az adópolitika helyi gazdaságfejlesztést élénkítő hatásairól beszélgettünk Szebeni Dáviddal, a Településfejlesztési Szövetség elnökével.
A diktatúrák és a humán fejlesztés
Authors: Polónyi István
Published: September 2024

A tanulmány célja egy olyan elemzés bemutatása, amely az ország kormányzásának autokratizmusa és a PISA eredmények, valamint a humán fejlettség (Human Development Index) közötti kapcsolatra világít rá. A korrelációs elemzés egyértelműen kimutatja, hogy – a PISA mérésben részt vevő országok halmazán vizsgálva – 2006 és 2022 között igen markáns korreláció található a jogállamiság (Role of Law) és a Human Development Index között, továbbá a jogállamiság és a PISA olvasás-szövegértés eredményei között is magas a korreláció. De számottevő korreláció van a demokrácia index (EIU Democracy Index) és a HDI, valamint a demokrácia index és a PISA eredmények között is. Ezt követően az elemzés kitér külön a magyar adatok vizsgálatára is. Magyarországra nézve azt állapítja meg a tanulmány, hogy a demokráciamutatók romlása együttmozog a PISA reading és a HDI mutató szerinti országrangsorban elért helyezés növekedésével (azaz a helyezések romlásával). Az elemzés kitér az oktatási és egészségügyi ráfordításoknak a két eredményességi mutatóval való kapcsolatára is, rámutatva, hogy ezek együttjárása ugyan releváns, azonban lényegesen alacsonyabb értékű, mint a demokrácia mutatókéval való kapcsolat. Az írás azzal a megállapítással zárul, hogy a hazai autokratikus kormányzásnak súlyos hatása van az emberi erőforrásaink fejlődésére.
A megfizetett tudás
Authors: Szabó Dorottya
Published: September 2024

A vállalatok sikerességében alapvető szerepe van a munkavállalóknak, akik a tudásuk és képességeik által nagyban meghatározzák a vállalat hatékonyságát és eredményességét egyaránt. Különösen igaz ez a tudásalapú gazdaság korában, amikor a készségek és képességek egyre fontosabb erőforrásokká válnak. Napjainkra a tudás és szakértelem megfizetése alapvető versenytényezővé vált, kiváltképp a kis- és középvállalkozások esetében, melyek számára ugyanakkor nagyobb kihívást is jelent versenyképes béreket biztosítani a munkavállalóik számára.
Az AI még nem képes az emberi ellenőrzés nélküli döntéshozatalra
Authors: Süle Ákos
Published: September 2024

Forrás: AI Isn’t Ready to Make Unsupervised Decisions, Joe McKendrick, Andy Thurai (2022), Harvard Business Review
Fogyasztók helyett állampolgárokként kell tekintenünk a társadalom tagjaira
Authors: Szabó Dorottya
Published: September 2024

A Project Syndicate portál nemrég közölt egy Mariana Mazzucato-val készült interjút [1], melyben arról faggatták a közgazdászt, hogy felülvizsgálhatónak tartja-e a 2020-ban Robert Skidelsky-vel közösen publikált véleményét [2], mely szerint a koronavírusjárvány okozta válsághelyzet bár megkövetelte a közkiadások jelentős mértékű megnövelését, megteremtve ezzel a lehetőséget arra, hogy az államok újradefiniálják gazdaságszervezői szerepüket, nem mondható el, hogy bármilyen újszerű fiskális politikai gondolkodás teret kapott volna ebben az időszakban, mivel a költekezések „strukturálatlanok” voltak. A kérdést elsősorban az Egyesült Államok fiskális politikai programcsomagjai (CHIPS and Sience Act, Inflation Reduction Act) ihlették, melyek Mazzucato szerint is komoly lehetőséget teremtenek az amerikai kormány számára arra, hogy a közkiadások célzott irányításával egy igazságos zöld transzformáció felé „terelje” a gazdaságot.
A New Drying Method of Thermolabile Flexible Endoscope Channels by Laminar and Turbulent Airflow: A Prospective, Randomized-Controlled, Single-Center, Proof-of-Concept Trial
Authors: Michael Florian A. , Jung Michael , Reimers Mike , Oschwald Clara , Mihm Ulrike , Welsch Christoph , Walter Dirk , Finkelmeier Fabian , Masseli Johannes , Pathil Anita , Dultz Georg , Puhlmann Danuta , Diaz-Martinez Laura , Hack Daniel , Lingwal Neelam , Bojunga Jörg , Kempf Volkhard A.J. , Zeuzem Stefan , Friedrich-Rust Mireen
Published: September 2024

INTRODUCTION:

International guidelines suggest different possibilities for drying of endoscopes during reprocessing. Clinical results of these available drying methods are not satisfactory. The aim of this study was to compare the drying cycle of a standard endoscope washer-disinfector (EWD) (standard drying method [SD]) with a shortened mandatory drying by the EWD followed by a special drying device using laminar and turbulent air flow (novel drying method [ND]).

METHODS:

Sixty endoscopes (duodenoscopes, colonoscocopes, and gastroscopes) from 3 different manufacturers underwent high-level disinfection and drying depending on the randomization group. Operational time of drying was measured for both groups. Residual fluid in the channels was measured using a laboratory scale. After a 14-day storage period, a sample of the endoscope channels was obtained to determine bacterial contamination.

RESULTS:

ND had significantly fewer residual water in endoscope channels (SD: 90% vs ND: 0%; P < 0.001) after high-level disinfection and drying and less bacterial contamination after storage for 14 days (SD: 47% vs ND: 20%; P = 0.028). Time consumed for drying in ND was also significantly shorter (SD: 16 minutes 4 seconds vs ND: 5 minutes 59 seconds; P < 0.001).

DISCUSSION:

Drying with a special automatic drying device was superior compared with an EWD's drying program as evidenced by no measurable residual water, reduced microbiological contamination, and a more than 2-fold decrease in operational time. Thus, drying by laminar and turbulent airflow may represent an attractive alternative to the currently used standard approach in the reprocessing process of flexible endoscopes.
Diez miradas a la lectura desde la biblioteca escolar
Authors: Trívez Pepe
Published: September 2024

La biblioteca escolar es mucho más que un espacio. La biblioteca escolar, allí donde se integra en el proyecto educativo y se pone al servicio del desarrollo de las competencias de los alumnos, es un instrumento privilegiado para formar lectores competentes, críticos y autónomos. Lectores que lo seguirán siendo al salir de la escuela. Lectores que encontrarán en la biblioteca el punto de partida, el refugio, el mapa y las indicaciones que les ayuden a conocer y desarrollar su identidad lectora.
Leer en tiempos de redes sociales. Tres propuestas para Secundaria y Bachillerato
Authors: Núñez Gutiérrez de San Miguel Beatriz
Published: September 2024

Este artículo ofrece algunas dinámicas lectoras orientadas a alumnado de Educación Secundaria Obligatoria y Bachillerato con el fin de ayudar al profesorado de estas etapas a trabajar la animación y el hábito lector con alumnos adolescentes cuyos intereses, en ocasiones, están centrados en el mundo digital y todo lo que este les aporta.
Mobile Application for Recognizing Colombian Currency with Audio Feedback for Visually Impaired People
Authors: Bolaños-Fernández Camila , Bacca-Cortes Eval Bladimir
Published: September 2024

Context: According to the census conducted by the National Department of Statistics (DANE) in 2018, 7.1% of the Colombian population has a visual disability. These people face conditions with limited autonomy, such as the handling of money. In this context, there is a need to create tools to enable the inclusion of visually impaired people in the financial sector, allowing them to make payments and withdrawals in a safe and reliable manner.
Method: This work describes the development of a mobile application called CopReader. This application enables the recognition of coins and banknotes of Colombian currency without an Internet connection, by means of convolutional neural network models. CopReader was developed to be used by visually impaired people. It takes a video or photographs, analyzes the input data, estimates the currency value, and uses audio feedback to communicate the result.
Results: To validate the functionality of CopReader, integration tests were performed. In addition, precision and recall tests were conducted, considering the YoloV5 and MobileNet architectures, obtaining 95 and 93% for the former model and 99% for the latter. Then, field tests were performed with visually impaired people, obtaining accuracy values of 96%. 90% of the users were satisfied with the application’s functionality.
Conclusions: CopReader is a useful tool for recognizing Colombian currency, helping visually impaired people gain to autonomy in handling money.
Inteligencia artificial explicable como principio ético
Authors: González Arencibia Mario , Ordoñez-Erazo Hugo , González-Sanabria Juan-Sebastián
Published: September 2024

Contexto: El avance de la inteligencia artificial (IA) ha traído numerosos beneficios en varios campos. Sin embargo, también plantea desafíos éticos que deben ser abordados. Uno de estos es la falta de explicabilidad en los sistemas de IA, i.e., la incapacidad de entender cómo la IA toma decisiones o genera resultados. Esto plantea preguntas sobre la transparencia y la responsabilidad de estas tecnologías. Esta falta de explicabilidad limita la comprensión de la manera en que los sistemas de IA llegan a ciertas conclusiones, lo que puede llevar a la desconfianza de los usuarios y afectar la adopción de tales tecnologías en sectores críticos (e.g., medicina o justicia). Además, existen dilemas éticos respecto a la responsabilidad y el sesgo en los algoritmos de IA.
Método: Considerando lo anterior, existe una brecha de investigación relacionada con estudiar la importancia de la IA explicable desde un punto de vista ético. La pregunta de investigación es ¿cuál es el impacto ético de la falta de explicabilidad en los sistemas de IA y cómo puede abordarse? El objetivo de este trabajo es entender las implicaciones éticas de este problema y proponer métodos para abordarlo.
Resultados: Nuestros hallazgos revelan que la falta de explicabilidad en los sistemas de IA puede tener consecuencias negativas en términos de confianza y responsabilidad. Los usuarios pueden frustrarse por no entender cómo se toma una decisión determinada, lo que puede llevarlos a desconfiar de la tecnología. Además, la falta de explicabilidad dificulta la identificación y la corrección de sesgos en los algoritmos de IA, lo que puede perpetuar injusticias y discriminación.
Conclusiones: La principal conclusión de esta investigación es que la IA debe ser éticamente explicable para asegurar la transparencia y la responsabilidad. Es necesario desarrollar herramientas y metodologías que permitan entender cómo funcionan los sistemas de IA y cómo toman decisiones. También es importante fomentar la colaboración multidisciplinaria entre expertos en IA, ética y derechos humanos para abordar este desafío de manera integral.
USING THE ACOUSTIC EMISSION METHOD, STRAIN GAUGE AND FRACTOGRAPHY TO ANALYZE THE PROCESSES OF DESTRUCTION OF SAMPLES FROM CARBON FIBER
Authors: Stepanova L. N. , Chernova V. V. , Sheifer S. V.
Published: September 2024

Static loading of Torayca T800 carbon fiber samples to failure was carried out, during which defects were registered using a microprocessor-based diagnostic acoustic emission (AE) system. The location of AE signals began in the area of the stress concentrator at loads not exceeding 30 kN. The analysis of the destruction process of samples at negative (–50 C) and positive (+80 C) temperatures was carried out. During their heating and cooling, thermal chambers were used, located in the region of a stress concentrator with a diameter of 12 mm. In the process of testing at a temperature of T = –50 C, an active location of AE signals was observed, corresponding, as shown by fractography, to delamination and destruction of the upper monolayers of carbon fiber. During tests carried out at a temperature of T = +80 C, AE signals were localized, caused by lateral delaminations located at the edges of the samples. Using wavelet transforms, an analysis was made of the features of changes in the main informative parameters of AE signals, and their relationship with the growth of damage (matrix, fiber, delamination) of the carbon fiber material.
CONTRAST RESOLUTION AND SHARPNESS OF EDGE IMAGES FORMING BY MICROFOCUS BREMSSTRAHLUNG OF A 18 MEV BETATRON AND RADIATIONS OF A 7 MEV BETATRON AND A 450 KEV X-RAY TUBE WITH SUB-MM FOCUSES
Authors: Rychkov M. M. , Kaplin V. V. , Smolyanskiy V. A.
Published: September 2024

Results demonstrating high contrast and good sharpness of magnified (2.44-fold) images of the edges of a 0.4 mm thick steel plate with one sharp edge obtained using microfocus bremsstrahlung of an 18 MeV betatron with a narrow (13 μm) internal tantalum target are presented. These images were compared with the images obtained using SEA-7 small-sized betatron with electron energy of 7 MeV and horizontal focus-size of 0.3 mm and X-ray tube MXR-451HP/11 with electron energy of 450 keV and focal-spot diameter of 0.4 mm. The results obtained show the promise of using a microfocus source based on a betatron for practical applications in high-resolution radiography and tomography, as well as in laboratory experiments, for example, in materials science and X-ray optics.
DEVELOPMENT OF A DEVICE FOR POSITIONING AND SIZING OF SMALL-SIZED METALLIC INCLUSIONS IN NON-CONDUCTIVE MATERIALS
Authors: Kuznetsov A. O. , Budadin O. N. , Chichigin B. A. , Kozelskaya S. O. , Fedotov M. Yu. , Malushin D. S.
Published: September 2024

The technology and equipment for eddy current detection of small-sized metal inclusions in products made of non-conductive materials has been developed. The developed technology and equipment can be used to detect small-sized metal inclusions ranging in size from 0.2 to 2.0 mm at a depth of up to 50 mm in non-conductive media, in particular polymer composite materials, to assess the quality of products and the stability of their manufacturing technology. Mathematical modeling of the process of detection and identification of small-sized metal inclusions using a multicoil eddy current transducer is carried out, which makes it possible to determine the control modes and characteristics of the device without carrying out expensive experimental work. The simulation results allow developing methods for processing signals from eddy current transducers, taking into account the characteristics of the material of the test object and small-sized metal inclusions. Experimental studies of the developed technology and equipment have been carried out, confirming the results of theoretical studies and the capabilities of the developed technology and equipment, with validation by alternative methods and means of control.
METHODICAL ASPECTS OF EVALUATING THE SENSITIVITY OF FIBER BRAGG GRATINGS TO MECHANICAL AND THERMAL EFFECTS FOR OPTICAL TESTING SYSTEMS OF POLYMER COMPOSITES
Authors: Fedotov M. Yu. , Vasiliev S. A.
Published: September 2024

The physical principles of optical non-destructive testing using fiber-optic sensors based on fiber Bragg gratings are considered using two experimental methods. For free fiber Bragg gratings recorded in optical fiber, two new experimental techniques have been developed to determine the linear and nonlinear strain and temperature sensitivity coefficients, as well as the cross sensitivity coefficient, which must also be taken into account when using a quadratic optical control model. Using the developed methods, which take into account the quadratic model of the optical non-destructive testing of polymer composite materials, experimental researches were carried out on the optical non-destructive testing of carbon composite samples during tests for static tension and temperature effects. Based on the results of experimental researches, correlation dependences of the relative change in the resonant wavelength of the fiber Bragg grating in the composition of the carbon composite on deformation and temperature were obtained, and the cross-sensitivity coefficient was estimated. It has been experimentally shown that the proposed approach can be adapted and widely applied to create integrated fiber-optic systems for optical non-destructive testing of structures during bench tests and real operating conditions.
DIAGNOSTICS OF THE ADHESIVE JOINT CONDITION IN MULTILAYER HONEYCOMB STRUCTURES MADE OF POLYMER COMPOSITE MATERIALS BY CONTACT LASER-ULTRASONIC EVALUATION
Authors: Kuryatin A. A. , Karabutov A. A.
Published: September 2024

Multilayer polymer composite honeycomb structures were investigated by Contact Laser-Ultrasonic Evaluation (CLUE). The size of adhesive fillets connecting honeycomb core with Carbon Fiber Reinforced Composite (CFRC) skin is determined. The correlation of strength indicators with the presence and size of adhesive fillets was confirmed. The possibility of non-destructive evaluation of local strength of CFRC structure with CLUE is dicussed.
INVESTIGATION OF THE METHOD OF AUTOMATIC COMPENSATION OF TREND COMPONENTS OF PHASE SIGNALS IN SYSTEMS OF PHASE-METRIC CONTROL OF GEODYNAMIC PROCESSES
Authors: Surzhik D. I.
Published: September 2024

Geodynamic monitoring is widely used to monitor and control the state of various objects, as well as to detect and evaluate their changes over time. The software and hardware systems that implement it for tracking the geodynamics of objects over long time intervals should effectively highlight the trend component in the processed data. A promising way to implement geodynamic monitoring is the use of phasemetric methods of geoelectric control. The block diagram of the phase change detection path using these methods contains a differential amplifier, a phase detector, a low-pass filter, and a highly stable reference oscillator. To eliminate an undesirable constant phase shift based on this method, it is proposed to use an automatic compensation method that allows the system phase to be adjusted automatically in real time. The result of using the auto compensator is the formation of a "new" reference signal for the phase detector, excluding the formation of these phase shifts in its output signal. To illustrate the proposed approach, the use of software implementation of automatic compensation of unwanted shifts to identify a trend in phase signals obtained during geodynamic monitoring of the near-foundation zone of a structure is considered, which has shown its effectiveness and the possibility of further practical use.
SIMULATION OF THERMAL COMPENSATION OF OPTICAL TESTING DATA OF COMPOSITE STRUCTURES BY AN EXTERNAL FIBER-OPTIC TEMPERATURE SENSOR
Authors: Fedotov M. Yu.
Published: September 2024

This article describes the theoretical aspects of thermal compensation of data from optical non-destructive testing of deformation of structures made of polymer composite materials using fiber-optic sensors based on fiber Bragg gratings. It is shown that at the stage of bench testing of composite structures, the method of thermal compensation using an external temperature sensor can be successfully applied. Linear and quadratic mathematical models of thermal compensation are analyzed and generalized. It has been established that with the comparative simplicity of the implementation of this method of thermal compensation, the error in determining the deformation is also provided at the level of the error of the interrogator. However, for online testing of composite structures during operation, the use of this method is difficult, due to the fact that the placement of an external temperature sensor is not always possible. The proposed method and the corresponding models can be applied in practice to develop methods for optical testing of samples and structures made of polymer composite materials during bench and other tests, taking into account thermal compensation.
PROPAGATION OF GUIDED ACOUSTIC WAVES IN THE SHAFTS OF CENTRIFUGAL PUMPS WITH LONGITUDINAL CRACKS OF AXIAL HOLES
Authors: Muravyeva O. V. , Shikharev P. A. , Murashov S. A.
Published: September 2024

During the production and operation of centrifugal pump shafts, defects may appear in their inner diameter, which in the vast majority of cases are longitudinal cracks. Such defects entail the complete destruction of the centrifugal pump power unit, production delay and high economic costs, while their detection by magnetic, eddy current, capillary types of testing is often excluded or limited due to the small internal diameter of the shaft. The work is devoted to the development of a new technique designed to detect defects in the axial holes of the shafts of centrifugal pumps by the combined use of two types of guided acoustic waves – torsional and longitudinal (rod). The technique is based on the use of echopulse and time-shadow methods of acoustic non-destructive testing. Within the work, studies were carried out on guided wave testing of three groups of shafts, divided according to the criteria of the methods used in the work, as well as computer modeling confirming the reliability of the testing result presented in the work. It is proposed to use a new informative parameter – the torsional wave velocity in the defective part of the tested sample. The results of experiments and computer modeling by the finite element method have shown the high efficiency of the studied method and the nonlinear nature of the dependence of the propagation of guided waves in the shafts relative to the number and size of cracks in axial holes.
DEVELOPMENT OF AN INFORMATION-MEASURING SYSTEM FOR DIAGNOSING INSULATORS ON OVERHEAD POWER LINES
Authors: Akhmedova O. O. , Atrashenko O. S.
Published: September 2024

The largest percentage of emergency shutdowns falls on overhead lines (overhead lines), which are the most vulnerable objects of the electric power complex. Frequent disconnections of overhead power transmission lines (VLEP) are caused by the overlap of insulators (due to complete destruction or the presence of defects). To change the current situation, it is urgent to develop an information system for determining the location of the damaged insulator and notifying about the (possible upcoming) disconnection of the section of the overhead line. It is proposed to install a piezoelectric contact sensor based on a direct piezoelectric effect on a garland of insulators. The changing acoustic pressure of the ultrasonic wave (formed by a change in the electric field strength caused by the deterioration of the insulating properties of the insulator) will generate an alternating voltage of the same frequency on the piezoelectric element. This indicator is supposed to be used as an indicator of the condition of the predamage of the insulator and transmit information to the operational control point.
THE METHOD OF MECHANICAL TESTING AND INVESTIGATION OF THE POSSIBILITY OF FATIGUE STRENGTH CONTROL BY THE MAGNETO-NOISE METHOD OF STEEL SAMPLES MANUFACTURED BY ADDITIVE TECHNOLOGY
Authors: Busko V. N. , Nichipuruk A. P. , Stashkov A. N.
Published: September 2024

Steel products manufactured using additive technologies are an alternative to traditional methods of their production. The specific method of their forming actualizes the issue of strict control of their quality, including fatigue strength. To investigate the possibility of control on the samples of low-alloyed steel 09G2S produced by selective laser alloying and, for comparison, by casting method, it is proposed to use the magnetic noise method. For mechanical tests of specimens in bending a simple original portable stand was created, a methodology of fatigue strength research and a program of specimen testing were developed. The tests have shown the efficiency of using the methodology and the bench in the study of fatigue strength. The results of evaluation of local heterogeneity of specimen properties before cycling and the effect on the magnetic noise level of the number of cycles at the initial period of loading at low cycle amplitude are presented.
An example of how to improve safety at selected pedestrian crossings
Authors: Kowalski Sławomir
Published: September 2024

Road safety continues to be a critical issue, especially for vulnerable road users such as pedestrians walking across the road at a place designated for the purpose. The most effective method of safety improvement at pedestrian crossings is to install traffic lights to control traffic. Such a solution cannot be used anywhere, however, due to the risk of the lack of flow capacity, especially in the area of nearby junctions. Therefore, persons responsible for traffic safety look for alternatives to improve the situation at pedestrian crossings. To meet the expectations of those persons, this article proposes mechatronic systems which are worth installing at selected pedestrian crossings to improve safety and reduce the number of traffic incidents involving vulnerable people. Three pedestrian crossings, considered dangerous by the authors, and located in the town of Nowy Sącz, were taken for analysis. Among the safety features, the use of an active sign informing of a pedestrian crossing, reflective elements and LED lights embedded in asphalt, as well as active pedestrian crossing illumination, are suggested. The proposed solutions are distinguished by low operating costs, as energy needed to power those solutions is obtained from photovoltaic panels.
Gaussian Process Regression as a precrash velocity determination method–subcompact vehicle class
Authors: Turoboś Filip , Mrowicki Adam , Konieczny Piotr , Madziara Szymon , Stajuda Łukasz , Šarkan Branislav , Kubiak Przemysław , Levchenko Dymytro , Meisner Nicole
Published: September 2024

The following paper presents an innovative approach to determining vehicle precrash velocity when hitting an immovable obstacle facing forward. Precrash velocity is necessary in order to perform a crash reconstruction. It is needed for the time-space analysis of the events, as well as to assesscrash mitigation and to evaluate drivers’ technique and tactics. For this task, the authors are using Gaussian Process Regression (GPR). Such an approach offers a number of advantages over the currently used methods that prove to be outdated when considering modern vehicles. The mathematical model was trained on a database shared by the National Highway Traffic Safety Administration.. This database covers a large number of crash tests of different kind, however authors focus on frontal collisions of the subcompact car class. Due to low accuracy of linear methods used up till now, Authors developed an innovative approach to determine the EES parameter utilizing Gaussian process regression. The newly developed method is an effective and accurate way to determine the vehicle’s velocity and shows promising results, as is demonstrated in this paper.
Los contextos comunicativos de la calidad del aire
Authors: Fernández Rodríguez Santiago
Published: September 2024

La estructura con la que se ha concebido este manual que aquí se presenta podemos dividirla en tres grandes bloques: Una parte sustancial del libro está orientada a la contextualización académica y social de la comunicación medioambiental y de calidad del aire. Otro bloque del texto se centra en el papel de la educomunicación y de la variable ciudadana como motor del cambio social del contexto de la ciencia en materia medioambiental. Y, por último, a lo largo del manual se ofrece una visión de la experiencia vivida en la utilización de herramientas e instrumentos comunicativos para lograr la transferencia de este conocimiento a la sociedad.
The The correlations between the average semester growth rates of syntactic and lexical complexity in L2 writing development at secondary school
Authors: Rokoszewska Katarzyna
Published: September 2024

The article is devoted to the development of language complexity in a relatively under-researched area of adolescent writing from the point of view of Complex Dynamic Systems Theory (CDST). It describes the second part of a panel study which aimed to examine the relationships among the average semester growth rates (ASGRs) of specific measures of syntactic and lexical complexity within and between these two subsystems in writing in English as a foreign language at the secondary school level. The study involved the analysis of The Written English Developmental Corpus of Polish Learners (WEDCPL). The corpus, which comprises over 1900 essays, was created on the basis of 21 repeated measurements conducted in a group of 100 secondary school learners during a period of three years. With respect to the specific measures of syntactic and lexical complexity, the study indicated that nominalization developed faster than subordination and coordination, and that lexical variation developed faster than lexical density and sophistication per semester. Moreover, the relationships between the ASGRs of both syntactic and lexical measures were more supportive within than between the subsystems. The main pedagogical implication for English language teachers refers to fostering more coordinated development of language complexity at secondary school in the EFL context.
Plurilingual literary writings as tools to develop students’ creativity
Authors: Kruszyńska Klaudia A.
Published: September 2024

In an era marked by rapid change, educators face a persistent call to nurture creativity in students, prompting them to explore innovative solutions. This study investigates the role of students’ plurilingual resources in fostering creativity within a foreign language classroom at secondary school level. Students collaboratively produced literary writings (songs, poems, and short stories) in which they applied their plurilingual resources (all of languages they knew). This case study employs a bottom-up approach to analyse students’ texts to determine whether facilitating the use of their diverse linguistic resources, including the blending of codes and modes, acts as a catalyst for creativity. The research results indicate that the foreign language classroom can indeed serve as a platform for students to engage in various forms of language creativity. The findings also suggest that encouraging students to utilize their diverse linguistic resources enhances language creativity. Additionally, the analysis highlights that the collaborative nature of the task supports the notion that exploring multiple solutions, rather than adhering to a single correct answer, fosters creativity. Furthermore, evidence indicates that creating a safe environment for learners is crucial for encouraging playful and unconventional language use for creative purposes.
Kompetencje akademickie studentów neofilologii. Postrzeganie problematyzacji w artykule naukowym
Authors: Karpińska-Szaj Katarzyna , Wojciechowska Bernadeta
Published: September 2024

The aim of the article is to summarize current trends in research on advanced skills in reading and writing academic texts and to analyze the ways in which a research paper may be explored by students of modern language studies at master’s degree level. The cited examples of strategies for reconstructing the logic of a research paper refer to the perception and expression of knowledge from a specialized field in verbal interactions, after completing a task which combines reading a selected research paper and using its content in their own text. The main aspect of the analysis is problematization, construed as the principal (structural and logical) axis of an academic text.
The Tenses of the Greek Metamorphoses
Authors: Tsakonas Giannis
Published: September 2024

Greece is a country of paradoxes: marvels and tragedies co-exist amid cultural tensions and contrasts, challenging every step and questioning the past, present, and future identity of its people. This article explores how the Greek library landscape has changed, following Tsimpoglou’s segmentation of the development of libraries in Greece, from the early isolationist years to 2000, when common sense led to collaboration; and the period from 2001, with critical oversight of the influential factors in understanding how Greek libraries can be fully functional and beneficial to society.