bluuebunny/crossref_metadata_2025 huggingface dataset:
"Professora, por que estamos sem recreio?"
Authors: Móre Letícia Ribeiro dos Santos , Camozzato Viviane Castro
Published: November 2024

O mote central deste artigo é problematizar o direito de participação das crianças na escola de Ensino Fundamental. Para tal, assume a concepção de que as crianças são sujeitos de direitos e, por isso, necessitam ter escuta e voz nas instituições, exercitando uma convivência democrática. O campo de pesquisa engloba uma turma de 5º ano do Ensino Fundamental de uma escola pública municipal do interior do Rio Grande do Sul, Brasil. A produção de dados envolve registros escritos, desenhos, fotografias e conversas realizadas com as crianças no decorrer de um estágio curricular obrigatório no Ensino Fundamental, realizado a partir do curso de Licenciatura em Pedagogia da Universidade Estadual do Rio Grande do Sul (Uergs). As análises indicam que as crianças se indagam, se posicionam e contribuem qualitativamente para a democracia escolar quando são vistas e consideradas, efetivamente, como sujeitos de direito à participação nas diferentes instâncias da instituição escolar.
Personagens negros/as na literatura infantil afro-brasileira
Authors: Sousa Marilia Rosalia Cordeiro Antas de , Silva Roseane Amorim da
Published: November 2024

O presente estudo buscou investigar a contribuição da literatura infantil afro-brasileira para a construção da identidade de crianças negras. Para isso, realizamos a análise de oito obras de literatura infantil, escritas por mulheres negras e com protagonistas negros(as). Os livros foram: O Mundo no Black Power de Tayó, de Kiusam de Oliveira; Meu Crespo é de Rainha, de bell hooks; As tranças, de Bintou de Sylviane A. Diouf; Betina, de Nilma Lino Gomes; Meninas Negras, de Madu Costa; Minha mãe é negra sim, de Patrícia Santana; Os tesouros de Monifa, de Sônia Rosa; e Minha dança tem história, de bell hooks. A escolha destas obras foi motivada pelo fato das mesmas possuírem temáticas que têm por finalidade romper com as representações que inferiorizam o(a) negro(a) e sua cultura. Para análise das narrativas apresentadas nos livros, nos subsidiamos na análise temática de conteúdo, e foram elencadas três categorias: a estética negra nas narrativas infantis; o reconhecimento enquanto negro/negra; e a resistência às opressões: tradição, ancestralidade e representatividade.
itinerário formativo “Trilhas de Aprofundamento” em uma escola da rede estadual pública catarinense
Authors: Martins Junior Luiz , Dias Julice , Pesce Marly  Krüger de
Published: November 2024

A reforma curricular do Ensino Médio impactou a prática docente ao instituir os itinerários formativos que possibilitam um percurso individual de formação do estudante. O Currículo Base do Território Catarinense (2020) institui como uma possibilidade a escolha de trilha de aprofundamento. O objetivo deste trabalho é compreender como o itinerário formativo “Trilha de Aprofundamento” é percebido por professores de uma escola pública catarinense. Para tanto, foi realizada uma pesquisa exploratória descritiva. Foi aplicado um questionário on-line para professores de uma escola pública de uma cidade de Santa Catarina, em 2023. Os vinte e cinco respondentes perceberam o potencial na oferta das trilhas, mas que é uma tarefa complexa, considerando a estrutura da escola e a formação docente. Além disso, os dados evidenciaram que os itinerários formativos não constituem contextos que introduzem oportunidades de Educação para a diversidade, para um currículo em ação que seja, de fato e de direto, aberto.
Você conhece as lagartixas das dunas?
Authors: Valgas Artur Antunes Navarro , Kasper Cubas Gustavo , Fonseca de Araújo Jéssica , Basso Cupertino Júlia , Helen Dias dos Santos Sarah , Ferreira Gohlke Samuel , Turcato Oliveira Guendalina , Verrastro Laura
Published: November 2024

Liolaemus arambarensis é uma espécie de lagarto endêmico das dunas de restingas, a oeste da Lagoa dos Patos no Rio Grande Sul. Atualmente, encontra-se em ameaça de extinção devido principalmente a sua restrição de nicho ecológico e a destruição de seu habitat. Em vista disso, fazem-se necessárias intervenções para conscientizar a população da importância deste ecossistema. A educação ambiental é importante na conservação ambiental, uma vez que aproxima o conhecimento científico da sociedade sensibilizando-a sobre as questões ambientais. O estudo objetivou realizar oficinas de educação ambiental sobre a importância da lagartixa-das-dunas para o ecossistema em clubes de ciências com a finalidade de conscientizar sobre a preservação do meio ambiente de forma lúdica. Foram aplicados jogos e apresentados exemplares da espécie da Coleção Científica. Para avaliação da efetividade das oficinas foi aplicado um questionário com perguntas abertas, onde as respostas foram feitas por Análise Textual Descritiva. Os resultados desta análise demonstram a efetividade da oficina e dos jogos educativos no processo de ensino-aprendizagem, assim como o desenvolvimento das competências e habilidades relacionadas ao meio ambiente previstas na Base Nacional Curricular Comum. Os estudantes desenvolveram consciência crítica sobre as ações humanas e os impactos destas na biodiversidade e no planeta.
Momentos históricos do Colégio de Aplicação da UFRGS marcam sua missão social
Authors: Benvenuti Juçara
Published: November 2024

Este artigo apresenta uma visão geral da criação do Colégio de Aplicação (CAp) da Universidade Federal do Rio Grande do Sul (UFRGS) até chegar às duas últimas décadas, quando desenvolveu quatro projetos de Educação de Jovens e Adultos (EJA). O principal objetivo deste texto é enfatizar a missão social do CAp, que partiu de um ginásio e atingiu a escolarização completa. Paralelamente comento o meu ingresso no Cap/UFRGS e minha adaptação ao fazer pedagógico diferenciado desta instituição, destacando minha trajetória como pesquisadora, extensionista, professora e coordenadora da EJA, bem como única docente que atuou nos 4 projetos. Para culminar trago dados da minha pesquisa, em andamento, Resultados Concretos na Vida Pessoal e Profissional de Egressos de Cursos de EJA da UFRGS, a qual complementa a pesquisa anterior, já publicada em livro, a qual descreve a criação e implantação de cada um dos 4 projetos. Até o presente momento foram entrevistados 7 ex-alunos do PEMJAT (turmas de 2000-2002), 7 do PROEJA (turmas de 2007-2008), 3 da CAE (turma de 2013-2015) e 6 da EJA REGULAR (turmas de 2013-2014), para estabelecer um perfil pós-curso e verificar as influências que o Colégio possa ter exercido em suas vidas pessoais e profissionais.
O Teatro conta a sua história no Colégio de Aplicação da UFRGS, ou parte dela
Authors: Molina William Fernandes
Published: November 2024

Por meio do entrelaçamento de textos autorais com memórias docentes, uma história narrando a presença do teatro no Colégio de Aplicação (CAp) da Universidade Federal do Rio Grande do Sul (UFRGS) é recontada neste artigo. A intenção da escrita é apresentar um histórico do princípio da trajetória do ensino de teatro no colégio, a partir da produção de um texto com estatuto de documento, visto que advém de narrativas pessoais amparadas em pesquisa bibliográfica e documental realizadas pelo autor (MOLINA, 2021). A narrativa enfoca o momento da introdução do teatro como componente na matriz curricular da instituição e descreve algumas ocasiões que resultaram em sua inserção derradeira no currículo da escola. As principais referências do texto são os relatos memoriais de Dias, Faleiro, Guarita, Malinoski, Saldanha e Vieira (2020), e documentos relacionados às primeiras aulas de teatro no CAp/UFRGS. O texto memorial decorrente da conjunção das lembranças narradas revela o CAp/UFRGS como vanguardista no cenário nacional da educação pública por oferecer aulas de teatro curriculares aos estudantes já na década de 1970 e por experimentar modos de fazer o teatro se introduzir e se desenvolver no contexto da Educação Básica.
Na Escola e no Museu:
Authors: Maffei Brandalise Guilherme
Published: November 2024

Este artigo traz o relato de experiência de dois espaços de atuação sobre a história indígena do Rio Grande do Sul, o projeto de Educação Continuada no Colégio de Aplicação e a curadoria da exposição Memória e Resistência no Museu de História Julio de Castilhos. Ambos relatos focam nas abordagens críticas sobre ensino de história indígena do Rio Grande do Sul, e as suas problematizações partem das limitações dos respectivos campos com o objetivo de abordar possibilidades de Ensino de História Indígena. Trazendo reflexões teóricas e metodológicas acerca das experiências em sala de aula e no museu, ou seja, de pesquisa, ensino e curadoria, este artigo aponta questões problematizadoras em comum, que podem gerar novas práticas de representação dos povos indígenas no ensino e no campo do patrimônio, buscando também uma relação de escuta com as comunidades contemporâneas. Concluindo que apesar do pouco tempo da obrigatoriedade desse tema nos currículos, uma abordagem que preze o diálogo e a experiência é fundamental para combater preconceitos.
Atendimento Educacional Especializado no Colégio de Aplicação da UFRGS:
Authors: Silva Mayara Costa da , Maciel da Silva Carla , Barros de Borba Bruna , Dos Santos Franzen Rafael
Published: November 2024

Este artigo tem como objetivo analisar o ensino colaborativo como estratégia potencializadora dos processos inclusivos a partir da experiência do atendimento educacional especializado no Colégio de Aplicação da UFRGS. Pautada em uma abordagem qualitativa, a investigação organizou-se a partir da análise documental e da revisão de literatura, bem como, da experiência do ensino colaborativo como proposta constituinte do atendimento educacional especializado. A análise documental levou em consideração os registros das professoras de educação especial com foco nos Anos Iniciais e na Educação de Jovens e Adultos. A revisão de literatura (2018 a 2023) envolveu os portais de periódicos Scielo e Redalyc. As análises foram realizadas a partir do referencial teórico que envolve o pensamento sistêmico, considerando, prioritariamente, os conceitos de relações e de rede. A partir da análise torna-se possível afirmar que o debate encontrado na revisão de literatura aponta para a importância do ensino colaborativo para o desenvolvimento de práticas pedagógicas mais inclusivas. Indica-se, ainda, a importância do aspecto formativo e de condições estruturais do contexto escolar para que o ensino colaborativo seja possível para qualificar as práticas docentes. Por fim, destacamos a emergência de mais produções acerca da temática a fim de contribuir com os processos inclusivos.
From culture to nature and back. A personal journey through the soundscapes of Colombia
Authors: Lamberto Coccioli
Published: November 2024

The purpose of this essay is twofold: to celebrate the astonishing richness and diversity of Colombia’s natural and human soundscapes, and to reconstruct the process through which my direct experience of those soundscapes has influenced my own creative work as a composer. Reflecting on a long personal and intellectual journey of discovery that plays out on many levels – musical, anthropological, aesthetical – helps bring to the fore important questions on music composition as the locus of cultural appropriation and reinterpretation. How far can the belief system of a distant culture travel before it loses its meaning? From a post-colonial perspective, can a European composer justify the use and repurposing of ideas, sounds and songs from marginalised indigenous communities? In trying to give an answer to these questions through the lens of my own experience I keep unravelling layer upon layer of complexity, in a fascinating game of mirrors where my own identity as a "Western" composer starts crumbling away.
Aprovechamiento del agua no convencional en sistemas urbanos
Authors: Morales Pinzón Tito , Flórez Calderón Manuel Tiberio , Orozco Gómez Iris Eliana
Published: November 2024

El Aprovechamiento del Agua no Convencional en Sistemas Urbanos es el resultado de varios años de investigación reunidos en un documento que presenta diferentes análisis sobre la alternativa de aprovechar agua de lluvia y aguas grises en un entorno urbano. El libro está estructurado en cinco capítulos. En el primero se presenta el contexto y los problemas que motivan el estudio. En esta sección se ofrece una mirada integral al aprovechamiento del agua no convencional desde un enfoque de los sistemas urbanos, partiendo desde un análisis a diferentes áreas urbanas de Colombia, siguiendo con el estudio de la vivienda como un sistema que debe propender por la sustentabilidad y finalmente detallando uno de los componentes básicos de la sostenibilidad como es la gestión del agua y específicamente el uso de agua no convencional como una alternativa que contribuye a dicha sostenibilidad. El capítulo segundo contiene una descripción detallada de los principales enfoques metodológicos empleados. Es así como se presentan los diferentes métodos y técnicas que permiten estimar el potencial de aprovechamiento del agua no convencional que ayudan a analizar el impacto potencial ambiental desde un enfoque del análisis de ciclo de vida. El tercer capítulo se centra en la descripción, análisis y discusión de diferentes sistemas y configuraciones estudiados, así como sus principales resultados desde el punto de vista ambiental. Se presenta de forma detallada en esta sección los resultados de dos sistemas de aprovechamiento de agua no convencional (edificio de una institución educativa y vivienda). En el sistema edificio se evaluó el sistema de aprovechamiento de agua de lluvia, mientras que en el sistema vivienda se evaluó el sistema de cosecha de agua de lluvia y se simuló la reutilización de aguas grises. El cuarto capítulo presenta la evaluación general realizada a la calidad del agua no convencional a partir de las muestras tomadas y de los análisis de laboratorio realizados, así como su comparación con diferentes estándares nacionales e internacionales. Finalmente, el quinto capítulo reúne las principales conclusiones del trabajo y presenta algunas recomendaciones generales y específicas sobre el aprovechamiento de agua no convencional en sistemas urbanos.
The concept of bio-regions and its relevance in achieving green goals
Authors:   Latvia University of Life Sciences and Technologies, Proskina Liga , Abduvasikov Abduaziz ,   Tashkent State Agrarian University, Uzbekistan, Galimova Firuza ,   Tashkent State Agrarian University, Uzbekistan, Proskina Daniela ,   Latvia University of Life Sciences and Technologies
Published: November 2024

Various initiatives worldwide promote sustainable, locally-based food systems and rural development, including Community Supported Agriculture (CSA), Farmers Markets, Food Hubs, Slow Food Movement, Regenerative Agriculture, and Agroecology Networks. These approaches often address specific challenges within narrower contexts. The concept of bio-regions offers a holistic approach to sustainable development, integrating ecological, social, economic, and cultural dimensions, demonstrating promising socio-economic and environmental impacts, and fostering community engagement and local development. Examples of good practices of bio-regions in European countries allow us to evaluate the relevance and possibility of application of this concept in Uzbekistan, as a strategy to promote sustainable development and resilience at the local and regional level. In the context of Uzbekistan, bio-regions can play a crucial role in achieving the country's green goals by addressing various environmental and socio-economic challenges while fostering sustainable development. By addressing these actualities and research on bio-region impact on local development in EU countries, researchers can contribute to advancing knowledge on community resilience and social cohesion in rural areas of Uzbekistan within the context of bio-regions. This can inform evidence-based policies, programmes, and interventions aimed at promoting sustainable development, environmental conservation, and social well-being in rural communities. The present research aims to investigate the theoretical and policy frameworks for the concept of bio-regions in the EU, which could be applied in achieving sustainability goals and solving environmental and socio-economic problems in Uzbekistan. Although there is no bio-regional policy in Uzbekistan, existing policy documents related to sustainable development, environmental conservation and rural development provide a basis for integrating bio-regional approaches into national strategies.
Realization of kink effect in the drain characteristics of III-nitride/β-Ga2O3 nano-HEMT due to traps and self-heating
Authors: Purnachandra Rao G. , Lenka Trupti , Nguyen Hieu
Published: November 2024

In this research article, a field-plated and recessed gate III-nitride
Nao-HEMT grown on ?-Ga2O3 substrate is designed. The electrical
characteristics of the proposed HEMT is investigated by using the thermal
models of ATLAS TCAD simulations. The investigation focuses on the impact of
traps and thermal influence that cause the Kink effect in DC characteristics
of III-Nitride/?-Ga2O3 HEMT. A noticeable kink effect is observed in
proposed III-Nitride/?-Ga2O3 HEMT. This phenomenon is typified by an abrupt
rise in drain current at high gate voltages, which causes the device to
behave non-linearly. The kink effect is most likely caused by traps in a
barrier layer activating. A field-plate, gate length, and gate recessed
depth of 20-nm each is considered for the analysis. Furthermore,
self-heating effect in drain current characteristics are investigated with
temperature changes. The findings demonstrated that scattering processes
that emerge when temperature increases above a particular amount cause both
the mobility and the carrier concentration of 2DEG to decrease.
Consequently, the output current performance degrades as a result of the
selfheating effect becoming more noticeable. In addition, the drain lag
phenomenon is investigated in connection with the drain current's transient
behavior. The duration of the channel's formation and ability to permit
current flow between the drain and source terminals is the reason for this
drain lag phenomenon. It is hypothesized that the device's channel length,
trapping and de-trapping, and thermal influence are some of the factors that
affect the drain lag. Finally, the implications with this drain lag
phenomenon are investigated.
Performance analysis of PLL control strategies on grid connected PV system under disturbed grid conditions
Authors: Khanna Aakriti , Garg Anjali , Parihar Singh
Published: November 2024

The rising demand for renewable energy, particularly solar power, stems from
its immediate availability and the imperative to curb carbon emissions
associated with fossil fuel consumption. Consequently, there has been a
significant surge in the installation and development of grid-connected
Photovoltaic (PV) systems. However, integrating PV sources with the grid
presents various challenges related to power quality. This article aims to
explore how grid-connected PV systems perform when faced with different
disruptions within the grid. To address this, a novel Dual Sliding Fourier
Transform (DSFT) Phase-Locked Loop (PLL) control strategy has been proposed.
The methodology involves modeling a typical grid-connected PV system. The
proposed and conventional control strategies to regulate the grid-connected
inverter have been implemented under four distinct disturbed conditions:
frequency disturbance, harmonic disturbance, phase jump disturbance, and DC
offset disturbance. This approach is further compared with the traditional
techniques, namely Dual Second Order Generalized Integrator (DSOGI PLL) and
decoupled stationary reference frame (d?? PLL). The evaluation criterion
considers the time required to track frequency changes, mitigation of
harmonics, and accuracy in phase error estimation. The findings reveal that
the DSFT PLL control strategy outperforms the conventional techniques across
all four disturbed conditions in the context of grid-connected PV systems.
Reforming EU enlargement decision-making: Lessons from the Bulgarian and Greek vetoes on North Macedonia
Authors: Christidis Yorgos
Published: November 2024

This article examines North Macedonia as a prime example of a candidate state
whose efforts to join the European Union (EU) have been repeatedly hindered
by vetoes from several Member States, including Greece, France, and
Bulgaria. The author argues that North Macedonia?s case highlights both the
necessity and the challenges associated with reforming the EU?s enlargement
decision-making mechanism. From a comparative and historical perspective,
this paper examines the Greek and Bulgarian vetoes in North Macedonia?s
accession process within the context of prevailing narratives in the two
countries? policymaking. The author uses document and discourse analysis.
The article concludes with insights into the ?logic? of national vetoes, the
stakes involved in their use, and the prospects for reforming the EU?s
enlargement decision-making process.
Patterns of bilateral military alliances formation and political regimes in Central Europe, 1962-2003
Authors: Stekic Nenad
Published: November 2024

This study examines the dynamics of political regimes as pivotal factors
shaping bilateral military alliances (BMAs) in Central and Eastern Europe
(CEE) from the aftermath of the Cuban Missile Crisis (1962) to 2003. Using
data from the Alliance Treaty Obligations and Provisions (ATOP) and the
Polity IV databases, the research investigates statistical correlations
between the formation of military alliances, their typologies, and political
regime-type dynamics. Research questions include exploring the key
characteristics of BMAs, the political regime nature of dyads, correlations
between alliance durability and democracy levels, and the impact of regime
changes on alliance phases. A sample of 88 BMAs is analysed, exploring
hypotheses on relationships such as alliance duration, political regime
congruity, member asymmetry, treaty provisions, and changes pre- and
post-Cuban crisis. Key findings indicate that less democratic dyads tended
to sustain longer alliances, while the hypothesis on political regime
congruity in military alliances received partial support. The study
contributes to understanding how political regime dynamics influence
alliance formation and longevity in a region historically shaped by the Cold
War geopolitical dynamics.
Pupil size and retinal hazard
Authors: Shand Mark
Published: November 2024

For wavelengths posing a retinal hazard, current laser safety standards specify an unaided eye measurement condition using a 7 mm aperture that is a proxy for a dark adapted human pupil.

In bright ambient conditions the human pupil is generally much smaller. In a perfect lens for an aperture filling beam the diffraction limited spot size of a collimated beam is the fourth power of the pupil size. So it may appear that the standards are overly conservative in outdoor daytime conditions.

However the eye is not a perfect lens. It is generally understood that aberrations increase with pupil size, limiting the optical quality of a dilated pupil, and thus limiting the growth in peak irradiance after focussing as the pupil dilates.

In this work, we leverage existing data sets of aberrations of several hundred eyes and, using a computer eye model, we estimate the peak irradiances achieved at different pupil sizes. We find for the typical eye in these data sets, the hazard posed by a 7 mm beam of fixed radiance, as estimated by the modeled peak retinal irradiance, is significantly reduced by a 3 mm pupil, but does not increase significantly beyond around 5 mm and may indeed be lower for a fully dilated pupil.
Human laser skin dose-response model
Authors: Ahmed Elharith M. , Early Edward A. , Lund Brian J. , Thomas Robert J.
Published: November 2024

The increased use of high-power (tens of kilowatts) laser systems in numerous applications drives the need for a generalized human dose-response model for skin injuries to achieve improved fidelity for risk assessment. Advancing the probabilistic approach to assess the risk of potential laser induced skin injury allows for a quantitative analysis of uncertainty and variability. This understanding should improve the assignment of exposure limits and protective approaches. In the present study, we developed a human dose-response model for laser induced skin injuries. It consists of three sub-models; one for the mean effective dose, one for variability of the mean effective dose, and one for the angle of incidence. The mean effective dose model is a generalized form for a minimum visible lesion (MVL) threshold achieved by scaling the maximum permissible exposure in the ANSI Z136.1 standard across all applicable wavelengths, exposure durations, and injury types. The variability model accounts for differences in skin spectral absorption between humans and uncertainties in scaling for the mean effective dose, and the angle of incidence model assimilates the effects of incident angle variability into the probability of injury. Use of the dose-response parameter models (mean, variability, and incident angle) for calculating a probability of injury is detailed and comparison with empirical data is illustrated.
Review of experimental and computer model retinal injury thresholds in the wavelength regime of 1300 nm to 1400 nm
Authors: Schulmeister Karl , Rauter Patrick , Stuck Bruce E.
Published: November 2024

Experimental and computer-model retinal injury thresholds in the regime of 1300 nm to 1400 nm indicate a need to revise the wavelength dependence of the laser safety exposure limits (MPEs) of ANSI Z136.1-2014, ICNIRP and IEC 60825-1:2014. The wavelength dependence of the MPE is expressed by the factor CC in ANSI laser safety standard and the ICNIRP laser exposure limit guideline, and C7 in the IEC laser safety standard; all in the same way. Additionally to the retinal thermal limit, there are limitations provided by dual limits, such as to protect the cornea, that indirectly also limit the energy that passes through the pupil. Experimental injury thresholds in the pulsed regime are available by Vincelette et al. (2009) for a wavelength of 1318 nm in the pulsed regime, as well as by Lund et al. (1981) for 1338 nm mixed with 1318 nm emission. For a relaxed eye of the non-human primate, the exposures in these experiments do not represent small sources but are extended sources (extended retinal images). When the retinal image extent is determined for an actual laser source, a respective CE factor (C6 in the IEC standard) is applicable to increase the MPEs. The experimental data show that injury thresholds are very close or are below the MPE when the MPE is calculated for the respective retinal image diameter. Computer model thresholds fit well with the experimental data points. Computer model thresholds are presented in terms of wavelength dependence, pulse duration dependence and retinal image diameter. These can be used to provide input for a discussion to improve the respective MPEs.
What’s new in international laser safety and equipment standards?
Authors: Ertle William , Frederiksen Annette
Published: November 2024

This paper presents the status of existing standard publications, technical reports, and recommended practices within the international technical committee IEC/TC 76 “Optical radiation safety and laser equipment”, and the Accredited Standards Committee (ASC) Z136 of the American National Standards Institute. In layman's terms, the former addresses “laser equipment” while the latter addresses “user safety”, and is predominantly used within the United States. The standard series of ANSI Z136, IEC 60825 and IEC 62471, as well as joint documents with ISO within the ISO 11553 and ISO 19818 series will also be discussed.

Additionally, we provide an overview of new standards currently under development, and topics for future standards within these committees. Lastly, we will explain the structure of the two standardization committees for optical radiation, and how experts can get involved in the standard development process of IEC/TC 76 and ASC Z136.
New European laser product safety standards: Amendment for EN 60825-1 and EN 50689
Authors: Schulmeister Karl
Published: November 2024

At ILSC 2019, a paper reported on the progress of two European standardisation projects for laser products. These two standardisation documents have been both published in 2021. One is amendment A11 for EN 60825-1. Up to this amendment, the European version EN 60825-1 was identical with the international version IEC 60825-1, both published in 2014. For most laser products, the new European amendment A11 does not contain requirements that go beyond those of EN and IEC 60825-1:2014, other than the compliance statement on the label and/or in the manual. The only exception applies to the wavelength range of 1250 nm to 1400 nm, where amendment A11 defines an additional limit to protect the cornea. The reason for this is that in some cases, the Class 3B limitation which is a dual limit also in IEC 60825-1:2014 is not sufficient to protect the cornea. For consumer products, A11 requires compliance with EN 50689:2021. Amendment A11 also includes the IEC interpretation sheets in an annex.

EN 50689:2021 pertains to laser consumer products brought onto the market in Europe. It is harmonised under the Low Voltage Directive but will also be harmonised under the General Product Safety Directive. The main content of EN 50689 is to define which classes are permitted for consumer products. Child appealing laser products are distinguished from non-child appealing products. Some Class 3R lasers are permitted as consumer products, however, only when a number of specific requirements are fulfilled. For most Class 1 laser products (as long as they are not emitting in the UV wavelength range) as well as for Class 2 laser products (as long as they are not child appealing) there are no additional requirements defined in EN 50689, other than a statement of compliance with EN 50689 (which for Class 1 laser products can be in the manual).

Since the details of both documents are discussed in White Papers, in this paper the multi-fold limits that apply in the wavelength range of 1250 nm to 1400 nm are discussed.
Ionizing radiation hazards from the tight focusing of ultrashort laser pulses in ambient air
Authors: Payeur Stéphane , Powell Jeffrey , Vallières Simon , Fourmaux Sylvain , Connell Tanner , Evans Michael , Lassonde Philippe , Fillion-Gourdeau François , MacLean Steve , Légaré. François
Published: November 2024

Manipulating unconfined ultrashort pulsed laser beams is increasingly common in academic research laboratories. Normally, health risks associated with beam propagation and alignment can be mitigated using protective eyewear and following standard laser safety guidelines. A recent investigation [1] has uncovered an additional, unexpected health risk. While working with High Numerical Aperture (HNA) reflective optics in ambient air, it was demonstrated that the laser pulse intensity at the focus was sufficient to accelerate electrons to relativistic energies and generate high dose-rate ionizing radiation. Non-linear effects in these conditions usually distort the propagating wavefront and render difficult the proper focusing of the beam. We have shown this does not hold true when focusing the output of the ALLS 100Hz Mid-IR laser beamline (2.8 mJ, 12 fs pulse centered at 1800 nm) with a reflective optic having a Numerical Aperture (NA) close to 1. Using this configuration, a radiation dose of 100's of mGy per minute was measured at 50 cm from the focus in ambient air, which exceed public dose limits in a very short time. Non-negligible dose measurements have also been observed with longer pulse durations, shorter wavelengths and standard off-the-shelf tight focusing optics from traditional optical suppliers. In this specific case, when using HNA reflective optics with ultrashort pulsed laser beams, the Laser Safety Officer (LSO) should carefully assess the risk related to hazardous ionizing radiation emitted by the focused beam.
Probabilistic risk assessment modelling for laser directed energy weapon systems
Authors: Flemming Brian K.
Published: November 2024

An MPE-based assessment for a Laser Directed Energy Weapon (LDEW) system with a High Energy Laser (HEL) output will likely result in an impracticably large Laser Hazard Zone. An alternative probabilistic evaluation of the potential hazard may result in less onerous restrictions on the permitted laser firing envelope. However, a risk-based assessment similar to that used in the UK for target designator and rangefinder systems has yet to be developed for LDEW-type laser hazards.

The probabilistic technique accounts for the entire risk chain from laser source to irradiated observer. Unlike a deterministic evaluation, the probabilistic method requires the definition of an acceptable level of observable biophysical damage for eye or skin, from which the risk of the observer sustaining a laser-induced injury may be determined. The permitted restrictions on laser firing are then defined by the maximum allowable risk of an observer sustaining the maximum acceptable level of biophysical damage. This paper will briefly summarize the UK probabilistic method and consider the possible definition of acceptable biophysical damage limits for the risk-based evaluation of LDEW-type laser hazards.
Failure modes of control methods for laser generated fume during hair reduction procedures
Authors: Jones Lewis C. R. , Britton Jason , Tyrer John R.
Published: November 2024

Laser hair reduction is one of the most commonly performed minimally invasive cosmetic procedures. Risk assessment of a tertiary referral laser dermatology unit in England identified that there are still unknown hazards related to laser-generated fume from procedures that represent approximately half of all treatments in the unit. This uncertainty in fume hazard analysis was raised in response to significantly increasing awareness of respiratory risks and updated guidance on respiratory protective equipment for medical laser procedures because of the COVID-19 pandemic. This paper presented an analysis of the failure modes for the current control methods for laser-generated fume, which involve room ventilation, local exhaust ventilation, and respiratory protective equipment that rely heavily on administrative procedures to function correctly. The new respiratory risk methods guidance also affects the integrity of existing laser safety personal protective equipment. The identified failure methods were then analysed through the collection of laser-generated fume and provided new evidence of the laser-generated plume concentration hazard during in-vivo laser hair reduction procedures. The air quality of the treatment unit was measured over a typical day of procedures using optical particle sizing to calculate the PM2.5 mass concentration. The results identified a potential failure mechanism with existing control methods, as a maximum concentration of 298 µg/m3 could be observed during the day with all the existing methods in use. This was a single-day and treatment-type study on a laser. However, this analysis provides valuable evidence to laser medical practitioners and medical laser safety officers in any treatment environment of the potential for fume to bypass the current standard existing control methods. The paper presents recommendations for further analysis and the requirement for knowledge of the acute limits of laser-generated fume to understand the hazard potential.
Creating laser safety compliance synergies in the operating room
Authors: Medcalf Malcolm
Published: November 2024

To address the opportunity for better synergies between facility MLSOs and vendors to improve laser safety training and compliance in the Operating Room.
Computer model results on the wavelength dependence for retinal thermal injury in the visible regime
Authors: Schulmeister Karl , Rauter Patrick
Published: November 2024

In the visible wavelength range, the current laser safety MPEs to protect the retina issued by ANSI Z136.1, IEC 60825-1 and ICNIRP are constant, i.e. do not feature a wavelength dependence. It has been shown before by David Jack Lund in the pulsed regime that a wavelength dependence exists and can be theoretically supported by the pre-retinal absorption factors as well as the absorption in the RPE as function of wavelength. However, we show in this paper that the transmission/absorption-based wavelength dependence only applies to short pulses, where heat flow does not play a role. Computer modelling shows that the longer the exposure duration becomes, the flatter the wavelength dependence becomes, so that for the cw case the constant MPE in the visible wavelength range is an appropriate trend that is not unduly over-restrictive. For the pulsed regime, a constant wavelength dependence might be over-restrictive in the red wavelength range, but has the advantage of being simple.

Also, raising MPEs has to be done with care in order to sustain a sufficient safety margin, while lowering the MPEs should only be done when the current MPEs were found to be associated to a safety margin that is too small. The data is also relevant for an ongoing revision of the international safety standard for ophthalmic instruments, ISO 15004-2 and the USA standard for ophthalmic instruments, ANSI Z80.36.
Laser generated air contaminants
Authors: Mai Anni
Published: November 2024

In laser safety discussions, direct beam hazards receive all the attention while some non-beam hazards (NBHs) are often not recognized. Laser Generated Air Contaminants (LGACs) are unwanted products generally generated from damages, such as cutting, ablating, and thermal decomposing of target materials. As lasers are becoming more powerful, product thermal decomposition becomes very likely. Some decompositions generate carcinogenic particulates, such as silica and hexavalent chromium. Other materials decompose to toxic products, such as hydrogen chloride and hydrogen fluoride. A safer workplace will need to consider such potential exposures. When such hazards are recognized, assessed, and controlled, workers are better protected from exposure to hazardous substances.
Mixed reality for laser safety at advanced optics laboratories
Authors: Li Ke , Choudhuri Aradhana , Schmidt Susanne , Lang Tino , Bacher Reinhard , Hartl Ingmar , Leemans Wim , Steinicke Frank
Published: November 2024

Nowadays, high-power and multi-spectral lasers are increasingly demanded in many scientific experiments and industrial processes. However, direct exposure to these laser sources can lead to permanent eye damage. Individuals conducting research and development with these laser sources are required to wear laser safety goggles as a form of eye protection. Currently, most laser safety goggles are based on optical spectral filters, which could filter up to 99 % of the visible spectrum, rendering researchers working in hazardous and complex laboratory environments visually impaired.

In this work, we present a novel laser eye protection method that could provide full-band laser protection without reducing the user's visibility of the environment. We demonstrate a system based on a virtual reality (VR) headset with a stereoscopic see-through camera, which could be constructed in a way that all laser and ambient light is blocked from the human eyes. We revisit an empirical evaluation of our prototype conducted at the laser science and technology group (FS-LA) at DESY with 18 participants, including 14 laser experts. The evaluation results reveal that MR technology has the potential to offer a safe alternative to conventional laser safety goggles and has tremendous prospects in improving the complex and hazardous working conditions at advanced optics laboratories.
Are you ready to take control of surgical plume? it’s time to ensure clean air for safer care!
Authors: Smalley Penny
Published: November 2024

The hazards associated with surgical plume are well documented and there are increasing numbers of regulations, standards, focused on mitigating the risks surgical team members are exposed to, during the course of their daily work in the OR. This presentation will introduce the relationship between risk assessment and the development of a risk based management program for surgical plume. It includes a brief review of the hazards and risks of exposure to surgical plume, a discussion of how to interpret current legislation, regulation, and standards as applicable to developing policy that will comply with them, and a sustainable and clinically relevant step-by-step plan for implementation of facility policy.

Learning Objectives: Discuss the cause and nature of the hazards associated with surgical plume and the risk to perioperative personnel of exposure to those hazards.Identify both current and developing evidence-based legislation, regulations, and standards, for mitigation of surgical plume in healthcare practice settings.Summarize the steps needed to develop a sustainable, practical, and clinically relevant implementation plan
There is more to laser safety than just the laser
Authors: Bansal Sandeep
Published: November 2024

When discussing safety controls for a new laser project, the user typically thinks only of the laser. However, when utilizing lasers that have their own inherent hazards i.e., chemicals, gasses, etc., we must look beyond the beam in a holistic approach. These additional hazards require in-depth investigation to identify and may trigger long lead times to adequately address the controls that will be needed. Unidentified hazards and last-minute surprises could sink a project before it even gets started. In this era of cutting-edge and complicated research, it is no longer enough to be focused on just the laser hazard. Hazards such as worker exposure, flammable materials, and environmental concerns to name a few, are all critical aspects of developing a job hazard analysis for safely performing the work.

This paper will discuss lessons learned from a laser installation project. We will cover the roadblocks and potential pitfalls that were encountered along the way in work planning and the eventual success that came from engaging the full safety team. Implementing a successful project must include having a full scope of work, an understanding of all hazards, and a complement of disciplines to develop controls
Probabilistic water BRDF model
Authors: Bailey Albert , Early Edward , Kumru Semih , Ahmed Elharith
Published: November 2024

Is a reflecting surface, and therefore can be a hazard source when illuminated by a laser beam. The extent of the hazard has been a matter of concern on a regular basis over the years, with disallowing interactions of laser beams with water being the most conservative approach. Quantifying the actual hazard requires a bi-directional reflectance distribution (BRDF) model of the water surface, and it is probabilistic due to the nature of water surfaces. The surface of water has reflecting features over many length scales, from small ripples to large swells. These wave features depend on the wind speed, and their variability obviously complicates a BRDF model. A combination of models, one for small-scale features and another for large-scale, provides the basis for a probabilistic water BRDF. This presentation describes the components of the model and illustrates dependencies on wind speed and direction, laser beam diameter, and angles of incidence and reflection.
Translational application of safety standards to common laser practice issues
Authors: Owens Patti , Colbert Abigail
Published: November 2024

Patti Owens RN, MHA, CMLSO, Abigail Colbert CMLSO

The advancement of laser technology creates new beam and non-beam hazards with decisive laser safety controls. The diversity of laser technology, environments, personnel, and procedures dictate critical assessment skills for each unique clinical application. Compliance with regulatory agencies and non-governmental controls is necessary to mitigate potential injuries. This lecture will highlight areas of workplace non-compliance and how translated regulations and evidence-based practices can provide successful remediation outcomes.

ANSI Z136.3-2018 “Safe Use of Lasers in Health Care” Section 1.3.2.2 describes the evaluation of the potential hazards of each laser and control measures to mitigate risks to the patient and laser team members. These standards apply to whether a laser is owned, rented, or leased. Risk assessment and management are the foundation for establishing a successful facility-based Laser Safety Program. The LSO and other delegated laser team members must understand the nuances and risk factors associated with each laser’s wavelength, accessories, specialty procedure utilization, and personnel dynamics within the laser room.

Lecture will explore potential hazardous situations regarding non-compliance with laser protective eyewear, the creation of the laser treatment control area, staffing of the laser operator, and the use of smoke/plume evacuation equipment. Additional areas of potential hazards will be reviewed in regards to developing a laser safety program with an appointed LSO, consensus with an ENT shared airway protocol, and the need for education of the laser team. Common knowledge gaps related to deficiencies in one’s laser safety compliance background and the essential mediation skills necessary for the laser team will be explored. Exploring strategies for best practices for patient safety, risk management, and the creation of a successful laser safety program will be the ultimate goal of this presentation.
The need to simplify MPE corrections for repetitive pulse exposures
Authors: Sliney David
Published: November 2024

The guidance for determining the maximum permissible exposure (MPE) or the accessible emission limit (AEL) in laser safety standards has had a long history of attempts to provide an understandable method. In all cases one guiding principle is accepted (whether explicitly stated or not): At no time t during a train of pulses will the exposure exceed the MPE specified as a radiant exposure for that time period t, nor will the emission exceed the AEL specified as a radiant energy for duration t. This single general principle is actually the rule that applied to repetitive exposures in the 1985 CDRH standard, and presumably technically still applies. All of the other current standards have applied an additional correction factor CP or C5 to be applied to single pulses in the train and its value decreases with the number of pulses N. The logic of this type of correction factor is not well justified when one considers that thermal additivity is really dependent upon pulse interval and not on just N. The current guidance for product safety standards has become even more complex and the concern is that with greater complexity there is a greater chance for errors in the application of multiple rules. A guiding principle in establishing limits should really be to minimize complexity. For example, if a repetitive pulse exposure reduces the safety margin, but does not lead to a true risk of injury, should the limits not attempt to track the biological data and thermal injury predictions to the point of adding too much complexity? A fresh look at this issue is warranted.