bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantifying uncertainties in the sustainability evaluation of concrete materials considering regional characteristics in Japan
Authors: Vios Nicole Alexis Kwan , Henry Michael Ward , Opon Joel Galupo
Published: April 2022

In the evaluation of concrete sustainability, what constitutes "sustainable" to one region may vary from another. This often leads to methodological forms of uncertainties that makes the evaluation process more complex. As such, this paper aims to quantify the effect of uncertainties in the regional context on the sustainability evaluation of concrete materials. This is carried out by quantifying the regional context through establishing a weighting scheme and then integrating the obtained weights into the sustainability analysis of concrete materials in tandem with uncertainty analysis. Japan is used as a case study because although it relatively appears as a homogeneous country, its prefectures possess unique characteristics that may make the sustainability evaluation of concrete materials vary across prefectures. Cluster analysis is carried out in the 47 prefectures of Japan using a set of regional context indicators. Five clusters are identified with varying characteristics and these are translated into different weighting schemes. The established weights are used in the sustainability evaluation of concrete materials using multi-criteria decision-making analysis. The results showed that one mix is the most sustainable for four of the clusters and a different mix is the most sustainable for the remaining cluster. When uncertainty analysis is conducted, the effect of the weights in the sustainability evaluation is explained by examining the average scores of the concrete mixes and the variance of the scores across the five clusters. This investigation facilitated the understanding of how regional differences and the uncertainties associated with it impact the evaluation of concrete sustainability.
Edição comemorativa: 10 anos da Revista Educação e Políticas em Debate
Authors: Richter Leonice Matilde , Souza Vilma Aparecida de , Souza Raquel Aparecida
Published: April 2022

A Revista Educação e Políticas em Debate (REPOD) completa 10 anos de editoração em 2022. A REPOD nasceu vinculada à Linha de Pesquisa Estado, Políticas e Gestão em Educação do Programa de Pós-graduação em Educação (PPGED) da Universidade Federal de Uberlândia (UFU) e desde o seu prelúdio tem envidado esforços no sentido de colaborar com a divulgação de resultados de pesquisas e experiências inéditas que apresentem consistência, rigor e originalidade, proporcionando a pesquisadores(as), docentes e discentes de graduação e pós-graduação, de diferentes instituições nacionais e internacionais, espaço para a socialização de suas produções, especialmente na área de políticas educacionais, mas também aos demais interessados pela área de educação e humanidades em geral (FACED, 2021).
Currículos de referência para o ensino médio integrado no IFSP
Authors: Soares Marta Senghi , Abreu Claudia Barcelos de Moura
Published: April 2022

O artigo apresenta elementos da construção dos currículos de referência para os cursos de ensino médio integrado à educação profissional do Instituto Federal de Educação de São Paulo como processo importante e crivado por disputas entre diferentes concepções de educação e de sociedade. Procuramos demonstrar, por meio de análise documental, manifestação da comunidade acadêmica e pesquisa bibliográfica, que a discussão sobre os currículos aconteceu em paralelo – e por vezes atravessada – pela reforma do ensino médio. O atual momento exige clareza sobre os efeitos deletérios que a reforma do Ensino médio representa para a classe trabalhadora, tornando necessário reafirmar a educação como direito social e a defesa do ensino médio integrado na perspectiva da emancipação humana.
Consumo e produção sustentável na educação básica: reflexões entre a Agenda 2030 e a Base Nacional Comum Curricular
Authors: Dalbosco Claudio Almir , Souza Flávia Burdzinski de , Macedo Márcio de
Published: April 2022

Este texto tem como principal objetivo problematizar a forma como as ideias de consumo e produção responsável são abordadas pela Base Nacional Comum Curricular, a partir da Agenda 2030. O trabalho, de natureza bibliográfica e abordagem qualitativa, apoiou-se na leitura e interpretação de textos e documentos escolhidos a partir da perspectiva hermenêutica. Conhecer as demandas da Agenda 2030 e identificá-las na BNCC é fundamental para poder projetar qual deve ser o papel da educação em relação às questões ambientais e de sustentabilidade. O estudo permitiu compreender que, ao firmar um pacto mundial para a construção de um mundo sustentável e resiliente, o Brasil comprometeu-se, a partir da Base, a tornar efetiva a formação humana considerando esta inadiável necessidade ambiental.
The Effect of Motivation, Tax System Complexity, and Financial Conditions on Taxpayer Compliance
Authors: Muflihani Firna , Subroto Bambang , Rusydi Mohamad Khoiru
Published: April 2022

This study was conducted to determine the factors that influence the behavior of taxpayer compliance through tax planning, both internal and external factors. This study used analytical method of SEM (Structural Equation Modeling) with sample consisting of 346 corporate taxpayers and tax professionals in Samarinda City as the unit of analysis. Data were collected by distributing questionnaires either directly or via Google form. The results of this study prove that internal factors have a negative effect on obedient behavior directly and have a positive effect on tax-payer complianceÂ through tax planning. This study also proves that external factors have a positiveÂ effect on tax-payer compliance both directly and through tax planning. Therefore, itÂ can be concluded that the motivation for tax compliance is mediated perfectly by taxÂ planning. Meanwhile, the complexity of the taxation system and the financialÂ condition of taxpayer compliance is partially mediated by tax planning. The resultsÂ of this study imply the importance of tax planning in increasing tax payments.
Innovation Capability Strategy and Firm Performance in The Furniture Manufacturing Sector in Kenya
Authors: Were Jane Nasimiyu
Published: April 2022

The study sought to examine the contribution of innovation capability in strategy implementation on the firm performance of the furniture manufacturing sector in Kenya. It utilized a descriptive and explanatory research design with a population consisting of 686 managerial staff in the furniture manufacturing sector. The sample of 280 licensed firms was randomly selected by distributing questionnaires to the managers. A factor analysis was used to reduce the number of variables and establish the underlying constructs while analysis of moments of structures was applied to develop theory. It was found that innovation capability had a positive and statistically significant contribution to firm performance. The firm size and firm age were found not to have a moderating effect on the firm performance. The study provides an expansion of the conceptualization of the innovation capability framework. The findings showed that - in order to respond effectively to the business environment that has become so dynamic - firms particularly in the manufacturing sector need to find creative ways of adjusting their strategy implementation tactics in line with changes in the business environment.
Optimal Analysis of Functional Magnetic Resonance (fMRI) Using Nonparametric Permutation Method
Authors: Aljobouri Hadeel K. , Jaber Hussain A. , Çankaya Ilyas
Published: April 2022

The non-parametric permutation approach is an intuitive and flexible approach for the statistical analysis of fMRI data compared to the parametric techniques. This approach can also be used to verify the validity of less computationally expensive parametric approaches. The methodology concept and comparative features of non-parametric permutation methods have been handled and discussed by various researchers. However, no available explication of the method exists, also, no freely distributed program is implemented. Consequently, this technique has not been applied practically. In the current work, the App Designer Statistical Parametric and Non-parametric Mapping of Functional Magnetic Resonance Imaging (SPnPM fMRI) tool is proposed to address these issues. The SPnPM fMRI toolbox is an open-source package that is designed for crucial comparison analysis. The comparison is performed between the statistical parametric and non-parametric mapping of the second-level analysis of fMRI data. T-test utilizing Random Field Theory (RFT), smoothed pseudo-t-test applying a permutation test, and t-statistic utilizing a permutation test without smoothing, are carried out. In addition, the corresponding parametric results are qualitatively and quantitatively compared. The outcomes on real fMRI data show the non-parametric approach achieved suprathreshold voxels more than those achieved in the conventional approach. Such as the activation of the anterior cingulate at (3, 15, 45) coordinates equal to 402 voxels employing a non-parametric pseudo-t-test, while 75, 28 voxels at the same coordinates using the T-test non-parametric and t-test parametric using random field theory, respectively. Besides, more suitable for small sample sizes.
Drápal, J., Jiřička, V., Raszková, T. (eds.) České vězeňství
Authors: Boukalová Hedvika
Published: April 2022

Book review on Drápal, J., Jiřička, V., Raszková, T. (eds.) České vězeňství. Praha: Wolters Kluwer, 2021, 456 s.
Liturgy Beyond Sunday Morning: Christian Congregations and the Liturgia horarum
Authors: Klein Michael
Published: April 2022

In his essay, the German student of theology Michael Klein dedicates himself to the rela-tionship between Sunday and working day in Protestant liturgy. As he outlines at the beginning, in his opinion the sole concentration of the service on Sunday morning repre-sents a shortening. He contrasts this factual normality in many contemporary Protestant churches with individual historical examples of everyday liturgy, e.g. from the time of the Reformation. Especially he pays attention to the tradition of the Liturgy of the Hours as a model of daily worship. As an example of a successful integration of this tradition into community life, he refers to the Anglican Church. In a conclusion with a number of theses, he promotes a creative extension of the divine service over the week on the basis of biblical and systematic aspects and suggests the Liturgia Horarum as a possible source for such reforms.
Recenze: Amedeo Molnár: Theologia crucis. (Nedokončené přednášky z let 1989–90), k tisku připravil Ota Halama, Praha: Kalich, 2018, 211 stran, ISBN 978-80-7017-258-2
Authors: Wernisch Martin
Published: April 2022

Review of the book: Amedeo Molnár: Theologia crucis. (Nedokončené přednášky z let 1989–90), k tisku připravil Ota Halama, Praha: Kalich, 2018, 211 stran, ISBN 978-80-7017-258-2
Immersing learners in English listening classroom: does self-regulated learning instruction make a difference?
Authors: Xu Jian , Luo Kaizhou
Published: April 2022

Drawing on self-regulated learning (SRL) theory, this quasi-experimental research examined the effectiveness of SRL listening instruction and its influence on L2 listening motivation and strategy use. Quantitative data were collected from 80 undergraduate students who enrolled in an English listening course at a Chinese university. The experimental group (N = 40) received 17-week SRL English listening instruction, whereas the control group (N = 40) received traditional product-oriented listening instruction. All the participants completed pre- and post-listening proficiency tests along with questionnaires at the beginning and end of the intervention program. Results showed that influenced by SRL listening instruction, the experimental group outperformed the control group in the post-listening proficiency test with a large effect size, and SRL listening instruction also enhanced the students’ expectancy and the perceived importance of L2 listening comprehension, as well as fostering their top-down strategy use. Some pedagogical implications are discussed.
Wer hat nie richtig Feierabend?
Authors: Berk Beatrice van , Ebner Christian , Rohrbach-Schmidt Daniela
Published: April 2022

Zunehmend komplexer werdende Arbeitsprozesse, die Flexibilisierung und Entgrenzung der Arbeit sowie deren voranschreitende Subjektivierung eröffnen Erwerbstätigen neue Möglichkeiten, bergen aber auch Risiken. Der vorliegende Beitrag untersucht mit dem Phänomen des suchthaften Arbeitens ein bis heute für Deutschland nur schwach erforschtes Thema. So ist kaum bekannt, wie verbreitet arbeitssüchtiges Verhalten in Deutschland ist oder welche sozialen Gruppen von Erwerbstätigen in besonderem Maße davon betroffen sind. Auf Basis repräsentativer Daten für Deutschland aus dem Jahr 2017/18 und der Nutzung einer international etablierten Arbeitssuchtskala (Dutch Work Addiction Scale, DUWAS) kann gezeigt werden, dass suchthaftes Arbeiten kein Randphänomen darstellt. Während nur schwache Zusammenhänge zwischen soziodemografischen Merkmalen und arbeitssüchtigem Verhalten festgestellt werden können, tritt suchthaftes Arbeiten bei bestimmten Merkmalen der Beschäftigung (Arbeitszeit, Selbstständigkeit, Führungsverantwortung), des Betriebs (Betriebsgröße, Betriebsrat) und des ausgeübten Berufs häufiger auf.
Sozialpartnerschaft unter Spannung
Authors: Hopp Marvin , Kiess Johannes , Menz Wolfgang , Seeliger Martin
Published: April 2022

Dieser Beitrag untersucht anhand von Pressemitteilungen, Gastbeiträgen der Vorsitzenden und Presseinterviews, wie die Tarifparteien der deutschen Metall- und Elektroindustrie, Gesamtmetall und IG Metall, die Corona-Krise in der Öffentlichkeit darstellten. Die mit dieser Untersuchung eingenommene Framing-Perspektive verspricht Aufschluss darüber, wie die Tarifparteien die Handlungsfähigkeit der Sozialpartnerschaft einschätzen und welche Prioritäten sie setzen. Die Sozialpartnerschaft steht auch in den Kernbereichen des deutschen Wirtschaftsmodells in zunehmendem Maße unter Druck. Das spiegelt sich auch in unserer Analyse wider. Während auf den ersten Blick in der Beschreibung der Krise und dem Ruf nach staatlichen Hilfen zur Unterstützung der Wirtschaft und Sicherung der Beschäftigten eine Interessenkoalition besteht, ist diese genauer betrachtet durch ein starkes Ungleichgewicht gekennzeichnet. Nicht nur handelt es sich um rein strategische Kooperation bei spezifischen Themen (Autoprämie, Kurzarbeitergeld). Die Arbeitgeberseite besteht außerdem auf Lohnzurückhaltung und lässt die gewerkschaftlichen Aufrufe zur weiter reichenden gemeinsamen Verantwortungsübernahme unbeantwortet. Insbesondere vor dem Hintergrund weiterer Auswirkungen der Pandemie auf den Arbeitsmarkt wird so die gewerkschaftliche Verhandlungsmacht geschwächt und die Sozialpartnerschaft gerät weiter unter Druck.
Bubbles and OB associations
Authors: Drozdov Sergey A. , Vasiliev Evgenii O. , Ryabova Marina V. , Shchekinov Yuri A. , Nath Biman B.
Published: April 2022

Supernovae explosions (SNe) in a stratified interstellar disc can create large scale structures and outflows perpendicular to the disc. Their morphology and emission characteristics depend on interrelations between the number of exploded SNe, the ISM vertical scale height, the height above the ISM disc at which SNe are located, and the mid-plane density of ambient gas. When observed such out-of-plane gas structures do characterize properties of the driving SNe and reveal the presence of underlying stellar clusters. Even though the morphology and emission properties of such structures are sensitive to characteristics of ambient gas they might be used for rough estimates of the clusters’ mass.
Accounting for the role of asymptomatic patients in understanding the dynamics of the COVID-19 pandemic: a case study from Singapore
Authors: Liew Fu Teck , Ghosh Palash , Chakraborty Bibhas
Published: April 2022

Objectives

To forecast the true growth of COVID-19 cases in Singapore after accounting for asymptomatic infections, we study and make modifications to the SEIR (Susceptible-Exposed-Infected-Recovered) epidemiological model by incorporating hospitalization dynamics and the presence of asymptomatic cases. We then compare the simulation results of our three epidemiological models of interest against the daily reported COVID-19 case counts during the time period from 23rd January to 6th April 2020. Finally, we compare and evaluate on the performance and accuracy of the aforementioned models’ simulations.

Methods

Three epidemiological models are used to forecast the true growth of COVID-19 case counts by accounting for asymptomatic infections in Singapore. They are the exponential model, SEIR model with hospitalization dynamics (SEIHRD), and the SEIHRD model with inclusion of asymptomatic cases (SEAIHRD).

Results

Simulation results of all three models reflect underestimation of COVID-19 cases in Singapore during the early stages of the pandemic. At a 40% asymptomatic proportion, we report basic reproduction number R
0 = 3.28 and 3.74 under the SEIHRD and SEAIHRD models respectively. At a 60% asymptomatic proportion, we report R
0 = 3.48 and 3.96 under the SEIHRD and SEAIHRD models respectively.

Conclusions

Based on the results of different simulation scenarios, we are highly confident that the number of COVID-19 cases in Singapore was underestimated during the early stages of the pandemic. This is supported by the exponential increase of COVID-19 cases in Singapore as the pandemic evolved.
Effect of direct coal liquefaction residue on the properties of fine blue-coke-based activated coke
Authors: Tian Yuhong , Ren Qiaoxia , Bai Xueru , Liu Bailong , Jing Xiande , Lan Xinzhe
Published: April 2022

Activated coke was obtained by CO2 activation with disused fine blue-coke serving as the main raw material and direct coal liquefaction residue (DCLR) as binder. The effect of the dosage and activation temperature of DCLR on the compressive strength of active coke and desulfurization were mainly investigated. The experimental results showed that the compressive strength of the activated coke increased first and then decreased with the increase in the amount of D-DCLR (DCLR after ash removal). When the amount of D-DCLR was 40%, the compressive strength of the activated coke was 492.55 N and the specific surface area was the highest (189.78 m2·g−1) among other samples. The results show that the activated coke has a high removal rate for low concentrations of sulfur dioxide. This work provides a way for efficient utilization of DCLR, which avoids waste of resources and environmental pollution. In addition, it is important for finding green and efficient blue-coke powder processing and utilization technology for the sustainable development of the blue-coke industry.
Pleomorphism of the HPG axis with NR0B1 gene mutation — a case report of longitudinal follow-up of a proband with central precocious puberty
Authors: Zhang Jun , Chen Qiuli , Guo Song , Li Yanhong , Ma Huamei , Zheng Rujiang , Du Minlian
Published: April 2022

Objectives

X-linked adrenal hypoplasia congenita (AHC) is characterized by adrenal insufficiency and hypogonadotropic hypogonadism. Herein, we report a rare case of X-linked AHC with central precocious puberty (CPP).

Case presentation

An 11-month-old male patient was found to have premature pubarche, enlargement of the penis, and frequent erection. LH and FSH levels after the GnRHa test were in the pubertal range. Direct sequencing revealed a heterozygous variant of the NR0B1 gene. The proband was treated with hydrocortisone and 9-alpha fludrocortisone because of the significantly elevated ACTH and renin activity. The secondary sexual characteristics relieved gradually. The serum testosterone and LH subsequently returned to the prepubertal range. The basal serum FSH values have been between 1.0 and 2.0 IU/L since the age of 2.25 years, with extremely low AMH levels beginning at 3 years.

Conclusions

The clinical course of CPP with NR0B1 variant may be temporary. HPG axis status of X-linked AHC may probably be pleomorphic during the longitudinal follow-up.
Generic uniqueness of saddle point for two-person zero-sum differential games
Authors: Ji Wei
Published: April 2022

The generic uniqueness of saddle point for two-person zero-sum differential games, within the class of open-loop, against the perturbation of the right-hand side function of the control system is investigated. By employing set-valued mapping theory, it is proved that the majority of the two-person zero-sum differential games have unique saddle point in the sense of Baire’s category.
SAXS measurements of azobenzene lipid vesicles reveal buffer-dependent photoswitching and quantitative Z→E isomerisation by X-rays
Authors: Ober Martina F. , Müller-Deku Adrian , Baptist Anna , Ajanović Benjamin , Amenitsch Heinz , Thorn-Seshold Oliver , Nickel Bert
Published: April 2022

Photoresponsive materials feature properties that can be adjusted by light near-instantaneously, reversibly, and with high spatiotemporal precision. There is considerable interest in maximising the degree of photoswitching, and in measuring this degree during illumination in complex environments. We study the switching of photoresponsive lipid membranes that allow for precise and reversible manipulation of membrane shape, permeability, and fluidity. Though these macroscopic responses are clear, it is unclear how large the changes of trans/cis ratio are, and whether they can be improved. Here, we used small-angle X-ray scattering to measure the thickness of photoswitchable lipid membranes, and we correlate lipid bilayer thickness to trans/cis ratios. This reveals an unexpected dependency of photoswitching ratio upon aqueous phase composition. In buffer with ionic strength, we observe thickness variations twice as large as previously observed. Furthermore, soft X-rays can quantitatively isomerise photolipid membranes to the all-trans state; enabling X-ray-based membrane control. High energy X-rays do not influence the state of the photoswitches, presumably because they deposit less dose in the sample.
Recent advances in optical label-free characterization of extracellular vesicles
Authors: Imanbekova Meruyert , Suarasan Sorina , Lu Yao , Jurchuk Sarah , Wachsmann-Hogiu Sebastian
Published: April 2022

Extracellular vesicles (EVs) are complex biological nanoparticles endogenously secreted by all eukaryotic cells. EVs carry a specific molecular cargo of proteins, lipids, and nucleic acids derived from cells of origin and play a significant role in the physiology and pathology of cells, organs, and organisms. Upon release, they may be found in different body fluids that can be easily accessed via noninvasive methodologies. Due to the unique information encoded in their molecular cargo, they may reflect the state of the parent cell and therefore EVs are recognized as a rich source of biomarkers for early diagnostics involving liquid biopsy. However, body fluids contain a mixture of EVs released by different types of healthy and diseased cells, making the detection of the EVs of interest very challenging. Recent research efforts have been focused on the detection and characterization of diagnostically relevant subpopulations of EVs, with emphasis on label-free methods that simplify sample preparation and are free of interfering signals. Therefore, in this paper, we review the recent progress of the label-free optical methods employed for the detection, counting, and morphological and chemical characterization of EVs. We will first briefly discuss the biology and functions of EVs, and then introduce different optical label-free techniques for rapid, precise, and nondestructive characterization of EVs such as nanoparticle tracking analysis, dynamic light scattering, atomic force microscopy, surface plasmon resonance spectroscopy, Raman spectroscopy, and SERS spectroscopy. In the end, we will discuss their applications in the detection of neurodegenerative diseases and cancer and provide an outlook on the future impact and challenges of these technologies to the field of liquid biopsy via EVs.
Equity Return Expectations and Financial Wealth Holdings of U.S. Households
Authors: Cotwright Marty , Chatterjee Swarn
Published: April 2022

This paper examines the association between stock market return expectations and financial wealth holdings of older adults using the 2016 wave of the Health and Retirement Study. Our study finds that less than 30% of individuals assigned a greater than 50% probability that the market will earn a positive nominal return in the following year. However, considerable heterogeneities were observed across racial/ethnic groups. Health status, the cognitive functioning of older adults, and expectations of positive stock market return were positively associated with greater financial wealth holdings among households. Our study also finds that older age, and being female were associated with a higher probability of expected equity returns in the following period. Health status, cognition, and equity return expectations were positively associated with the financial wealth holdings of households. African Americans, Hispanics, and other races were negatively associated with the probability of equity return expectations and financial wealth holdings when compared with the reference group of non-Hispanic Whites. Overall, this study contributes to the literature by applying a unique mathematically derived measure of future return expectations, and extends the literature on equity return expectations and the financial portfolios of households. The negative association between being African American or Hispanic and financial wealth holdings is concerning. The findings from this study inform policy makers, and underscore the need for prioritizing programs and policies that can be play a critical role in building human capital, in promoting financial capability, and in bridging the financial wealth gap for households belonging to the disadvantaged and underserved racial ethnic groups.
If I were a weighted blanket
Authors: Owocki Sarah
Published: April 2022

This is a poem written in the first person, "by" a weighted blanket. It addresses the person who is using the blanket from two perspectives: firstly, a natural one and secondly, a commercialized one. This evokes the divide between the inherent purpose that a weighted blanket can serve as an assistive device for an Autistic person (a liberating potential) vs. its use and commodification in a medical system built around structures of profit and control. This tension is widely present in the Autistic community as well as among individuals who interact with those of us in the community. Confronting this tension helps with building an equitable world where Autistic people can be thriving members of our communities, rather than institutionalized or hidden away.
Conventional versus Additive Manufacturing—Comparative Eddy Current Testing on Reference Blocks
Authors: Mandache Catalin , Gibson Patrick , Denne Justin , Merati Ali
Published: April 2022

Metal-based additive manufacturing (AM) is a topic that cannot escape attention in most engineering fields. Its capabilities of having complex parts manufactured on demand, while reducing waste and cost, has raised the attention of the aerospace, automotive, and biomedical industries. Nevertheless, additively manufactured parts need to be proven to meet or exceed the quality and performance characteristics of their conventionally manufactured counterparts. Nondestructive evaluation (NDE) plays a critical role in the acceptance of AM, and reference specimens should be available for the performance evaluation of applicable techniques. From an NDE perspective, AM poses unique challenges, such as geometrically complex parts and manufacture-introduced flaws; anisotropy of mechanical, electrical, and elastic properties; as well as rough surface finish. Part quality and performance have to be assessed through a series of tests, including nondestructive ones. The detection capability of an NDE technique has to allow finding discontinuities smaller than the maximum allowable size. Development of NDE procedures along with design of suitable reference blocks need to be prioritized before the adoption of AM for mass production. Considering the lack of reference blocks for AM, with discontinuities specific to these manufacturing technologies and known critical defect type and size, some insights could be gained from the existing knowledge of inspecting conventionally manufactured parts. In this study, common eddy current reference blocks of aluminum and titanium alloys are examined by comparison with respect to fabrication modes (i.e., conventional versus additive). Maintaining the same instrumentation, parameters, procedures, and interpretation schemes, the eddy current technique is used to evaluate potential changes in inspection indications between the two manufacturing technologies. Moreover, metallography is performed on all blocks in an attempt to link microstructure with eddy current responses.
Novel or Improved NDE Inspection Capabilities for Additively Manufactured Parts
Authors: Obaton Anne-Françoise , Van den Bossche Alex , Burnet Olivier , Butsch Bryan , Zouggarh Imane , Soulard Florent , Johnson Ward
Published: April 2022

Additive manufacturing (AM) enables the production of parts with extremely complex shapes, such as lattice structures and internal structures (cavities, channels). As a result of this geometric complexity, the applicability of most conventional nondestructive testing (NDT) techniques to AM parts is limited, and innovative volumetric NDT methods are needed for quality control. Few established volumetric NDT methods are suitable for inspecting the integrity of parts with complex geometries. X-ray computed tomography (XCT) is widely recognized as the most powerful method for detecting and evaluating the dimensions of structural flaws and also for checking the compliance of parts with their numerical model. However, it is an expensive method. The image analysis takes more time than is appropriate for routine inspection, and the files are large and, thus, difficult to handle. Furthermore, XCT is not suitable for large and high-density parts. Alternative methods are therefore needed. Investigation of resonant acoustic methods such as resonant ultrasound spectroscopy (RUS) or electromagnetic-acoustic resonance methods, linear or nonlinear, has shown great potential. RUS methods are global, enabling identification of defective parts based on analysis of their natural resonant frequencies. There are several variants of RUS methods, but their basic principles are similar. They can inspect any part shape, and they are insensitive to inherent surface roughness. In addition, although they are global volumetric methods (“pass/fail”), they can inspect parts of any size, unlike XCT, which can determine the locations of defects but is restricted by the size or density of the parts. Moreover, compared to XCT, they are simple to implement, easy to use, quite affordable, and the inspection of the parts is particularly fast, which is very suitable for routine inspection. This article describes the capabilities of various linear RUS methods, as well as a nonlinear electromagnetic-acoustic resonance method for quality assurance of AM parts.
In Situ Measurement and Process Monitoring in Laser Powder Bed Fusion of Lattice Structures
Authors: Grasso Marco , Garghetti Federica , Pagani Luca , Colosimo Bianca Maria
Published: April 2022

Additive manufacturing enables novel classes of product complexity together with high levels of customization for functional components that shall meet strict quality requirements. Because of this, novel product qualification and statistical process control challenges must be faced in the industry. Traditional methods could become not applicable in this new scenario as they are based on monitoring simple geometrical or dimensional features, and they entail a training phase consisting of several copies of the same part. Because of this, the possibility of using data and signals acquired via in situ sensors during the process to support qualification procedures has been attracting a great deal of industrial interest. This study presents an in situ metrology method that combines in situ geometry reconstruction of the part via layerwise image segmentation and a quality modeling approach that allows estimating synthetic geometric patterns in terms of one-dimensional profile data. The method is specifically designed for lattice structures, one kind of complex shape enabled by additive manufacturing processes. It aims at providing a methodological framework to anticipate geometrical assessment and anomaly detection while the part is being built and even in the presence of one-of-a-kind structures. A real case study in laser powder bed fusion is presented to demonstrate the feasibility and benefits of the proposed approach.
3D Printing of Polymers with Continuous Fibers to Replace Steel Reinforcement and Structural Steel in Construction
Authors: Dubov Alexey , Ruben Sam , Korshikov Vasily , Ivanova Anna , Yakovlev Egor
Published: April 2022

Three dimensional (3D) printing technology has the potential for reshaping the construction industry. Despite advances in 3D concrete printing, the majority of construction applications still require structural steel or steel reinforcement in order to achieve code compliance. Development of polymer-based high-filled composite with a fiber reinforcement can be a better alternative to the cementitious composite for 3D printing while providing better strength and durability. These materials can be used in various civil engineering applications, including slab on grades, precast architectural panels, facade construction, and more. The current paper gives a first insight into the application of the newly developed polymer-based composite and 3D printing technology, combining composite extrusion, ultraviolet curing, and continuous glass fiber reinforcement. In this case, the fiber, which has been saturated with the organic binder, is laid out layer by layer on top of the extruded layer of the composite. Thus, the high adhesion between the matrix and the fiber is achieved. This study presents the current capabilities of 3D-printed structures with continuous fibers to eliminate steel reinforcement and structural steel in residential buildings. Advantages of the developed 3D printing technology amidst 3D concrete printing are described. The study also provides methods to evaluate the strength and durability of 3D-printed structures.
Control-Oriented In Situ Imaging and Data Analytics for Coaxial Monitoring of Powder Bed Fusion Additive Manufacturing
Authors: Jiang Tianyu , Leng Mengying , Chen Xu
Published: April 2022

Despite recent advancements in powder bed fusion additive manufacturing, in-process monitoring and quality assurance remain insufficient for wide applications in production. One obstacle is the interpretation and evaluation of the intense monitoring data. The objective of this study is to discuss a data processing infrastructure for coaxial sensing toward consistent and repetitive additive manufacturing. The infrastructure is developed based on an image database collected from an in-house-developed powder bed fusion platform. This work first addresses salient issues in the raw data (e.g., noises, inconsistent illumination, and low contrast) leveraging several preprocessing algorithms. By utilizing graph-based segmentation, the authors' approach then leads to an innovation to isolate laser-fused materials from the unmolten powder bed. In the experiment of printing an overhang structure, this study provides detection of the formation of an overheating defect and proposes new features that correlate to part geometry and process parameters. These results can be further used to bridge the gap between spatially resolved process monitoring and ultimate model-based control for robust and high-throughput additive manufacturing.
Effect of Coaxial Powder Nozzle Jet Process Parameters on Single-Track Geometry for Laser Beam Directed Energy Deposition Process
Authors: Jardon Zoé , Ertveldt Julien , Guillaume Patrick
Published: April 2022

The major challenges faced by powder-based laser beam directed energy deposition are the powder efficiency and the part quality assurance. One of the main ways to quantify the quality of a printed part is its geometry. This paper aims to study the influence of gas and powder process parameters on the geometry of single deposited tracks using 316L stainless steel in powder-based laser beam directed energy deposition. The gas and powder settings are defined as the carrier and shielding gas volumetric flow rate, the powder mass flow rate, and the particle diameter. The track geometry is evaluated based on the deposition width, deposition height, area of deposition, contact angle, dilution depth, and degree of dilution. The single tracks are printed using the MiCLAD in-house hybrid directed energy deposition machine developed by the Additive Manufacturing Research Group of the Vrije Universiteit Brussel. Their geometry is evaluated by means of laser triangulation and micrographs of single-track transversal cross sections and differences in results are highlighted. The overall results show that powder mass flow rate and particle diameter range are the main parameters affecting the track's geometry and powder efficiency. The shielding and carrier gas volumetric flow rates show an effect on the geometry, but no clear tendencies can be retrieved. This highlights the presence of a complex relationship between powder mass flow rate, shielding, and carrier gas volumetric flow rate. The ratio shielding/carrier volumetric mass flow rate is revealed to be an essential factor impacting the printing process.
The Effect of Additive Manufacturing Parameters on Microstructure and Mechanical Properties of Biomedical Grade Ti-6Al-4V Alloy
Authors: Neto Mozart Queiroz , Yuh Catherine , van Arkel Richard , Hall Deborah J. , Orías Alejandro A. Espinoza , Pourzal Robin
Published: April 2022

Additive manufacturing (AM) has the potential to revolutionize the biomaterials field by enabling the affordable and quick production of custom-made implants to fit specific patient needs and anatomy. There already exists literature on the relationships among process parameters, microstructure, and mechanical properties; however, the relationship of complex structures with varied shapes needs further investigation. Therefore, this study sought to determine the effects of AM laser power, exposure time, point spacing, and strut diameter on the microstructure of as-printed Ti-6Al-4V for biomedical application. Mechanical properties of as-printed Ti-6Al-4V samples were assessed by nanoindentation and compared to that of a wrought Ti-6Al-4V control. The AM samples were found to have fine needle-like shape grains, similar to martensite, where the grain size decreased with higher laser power and longer exposure time. All AM samples had low β phase content and the alloying elements were homogenously distributed. Prior β phase colonized with fine α’ phase was identified by the orientation maps—electron backscattered diffraction. Manufacturing defects such as gas porosity and lack of fusion were observed, as well as the presence of cracks. The AM samples were found to have increased hardness and decreased reduced elastic modulus compared to the wrought control. The observed differences in mechanical properties are likely related to the microstructure of these samples. These findings demonstrate that AM alloy microstructure influences both bulk and local properties. This presented study provides additional context into this relationship, furthering the understanding of the complex environment of biomedical implants.
Developing Storage and Handling Guidelines for Additive Manufacturing Metal Powder Feedstock
Authors: Hall Steven , Chrostek‐Mroz Aneta , Dawes Jason
Published: April 2022

Inappropriate storage conditions for additive manufacturing (AM) metal powder feedstock may negatively affect powder and final AM component properties. There are various storage solutions currently available for metal powders; however, there is no guidance or consensus on which methods are most appropriate and no indication on powder shelf life for selected storage solutions. The aim of this study was to evaluate the consequence of storage conditions on powder properties and AM built part properties to evaluate if storage conditions can minimize the changes in powder and part properties. Three metal powders (titanium alloy [Ti‐6Al‐4V], nickel alloy [Alloy 718], and aluminum alloy [AlSi7Mg]), commonly used in laser powder bed fusion, were stored for 6 months in a range of storage conditions. The storage conditions included factors such as container type (metal, plastic, or open), container backfill (air or argon), control aids (desiccant, oxygen scavenger, or none), and external environment (BOC/Linde ADDvance inert gas powder cabinet, humidity/temperature controlled lab, or outside). In the second part of the study, electron beam power bed fusion/Ti6‐Al‐4V powder was stored for 8 months in two industrially relevant storage conditions, in both controlled and uncontrolled temperature and humidity environments. Parts (tensile bars and cubes) were made from each powder batch using a Renishaw AM500M and the part properties were compared. Overall, no effect was found between the two storage conditions investigated on the part properties. However, there was found to be an advantage to using controlled storage environments for Ti‐6Al‐4V and AlSi7Mg metal powders for maintaining powder flow properties and hydrogen levels, respectively.
Which Features of Prosocial Spending Recollections Predict Post-Recall Happiness? A Pre-registered Investigation
Authors: Cash Tiara A. , Aknin Lara B. , Proulx Jason D. E.
Published: April 2022

People frequently spend money on others and research shows that such prosocial spending often promotes the benefactor’s happiness, even sometimes when reflecting upon past prosocial purchases. But on whom and what do people generally spend their money? And what features of prosocial spending memories are associated with greater post-recall happiness? In a pre-registered examination, human coders and a text analysis software coded over 2,500 prosocial spending recollections for information regarding the target, content, and presence of five theoretically motivated dimensions: affiliation, volition, impact, authenticity, and level of detail. Exploratory analyses revealed that people often recalled buying gifts or food and typically spent money on significant others, friends, or children. Consistent with the pre-registered hypotheses, higher levels of volition and impact were associated with greater post-recall happiness (rs: .05 – .07), controlling for pre-recall happiness. However, in contrast to the pre-registered hypotheses, affiliation, authenticity, and level of detail did not predict greater happiness. These findings illuminate some key characteristics of prosocial purchases and the most rewarding features of people’s prosocial spending recollections.
Alignment of optical backscatter measurements from the EXPORTS Northeast Pacific Field Deployment
Authors: Erickson Zachary K. , Cetinić Ivona , Zhang Xiaodong , Boss Emmanuel , Werdell P. Jeremy , Freeman Scott , Hu Lianbo , Lee Craig , Omand Melissa , Perry Mary Jane
Published: April 2022

Backscattering of light is commonly measured by ocean observing systems, including ships and autonomous platforms, and is used as a proxy for the concentration of water column constituents such as phytoplankton and particulate carbon. Multiple on-going projects involve large numbers of independent measurements of backscatter, as well as other biologically relevant parameters, to understand how biology is changing in time and space throughout the global ocean. Rarely are there sufficient measurements to test how well these instruments are inter-calibrated in real-world deployment conditions. This paper develops a procedure to align multiple independently calibrated backscatter instruments to each other using nearby profiling casts and applies this method to nine instruments deployed during a recent field campaign in the North Pacific during August–September of 2018. This process revealed several incorrect calibrations; post-alignment, all nine instruments aligned extremely well with each other. We also tested an alignment to a deep-water reference and found that this method is generally sufficient but has significant limitations; this procedure lacks the ability to correct instruments measuring only shallow profiles and can only account for additive offsets, not multiplicative changes. These findings highlight the utility of process studies involving several independent measurements of similar parameters in the same area.
Structural properties of AuNPs/PSi nanostructure
Authors:   Physics Department, College of Education for Pure Science, University of Mosul, Iraq, Ali G. G. , Ahmed M. A. ,   Physics Department, College of Education for Pure Science, University of Mosul, Iraq, Sulaiman A. A ,   Department of Physics, College of Science, Mosul University, Iraq
Published: April 2022

Nanostructure porous silicon (NPSi) was achieved by electrochemical etching. A p-type silicon of resistivity (0.1-0.02 Ω.cm) and n-type silicon of resistivity (1.5-4 Ω.cm) were immersed in 25% HF at etching time of 15 min and fixed current density 20mA/cm2 . Moreover. A gold nanoparticles were produced by laser ablation of energy (250, 350 and 450 mJ). The AuNPs were deposited on PSi layer ending up with a AuNPs/PSi.The structural, morphology and Raman properties of the AuNPs/PSi were all investigated. Xray diffraction showed that the Au nanoparticles revealed a polycrystalline face-centered cubic structure (FCC). Furthermore, FESEM images displayed that the AuNPs have entered inside the pores with uniform sizes. Additionally, Raman spectrum showed shifting on the broadening peak below 520 cm-1 when laser energy is increased in p-type silicon. AuNPs plays crucial role and very effective to enhance this property.
Reactive oxygen species (ROS) dependent antibacterial effects of graphene oxide coatings
Authors:   School of Medicine, Hubei Polytechnic University, Huangshi 435003, China, Zhao C. , Zhang L. ,   Department of Pharmacy,Changhai Hospital, Naval Medical University, Shanghai 200433, China, Wu H. ,   School of Public Health, Xinxiang Medical University, Xinxiang, Henan, 453003, China, Song X. ,   School of Life Sciences and Technology, Xinxiang Medical University, Xinxiang, Henan, 453003, China, Chen Y. ,   School of Life Sciences and Technology, Xinxiang Medical University, Xinxiang, Henan, 453003, China, Liu D. ,   School of Life Sciences and Technology, Xinxiang Medical University, Xinxiang, Henan, 453003, China, Lei P. ,   School of Life Sciences and Technology, Xinxiang Medical University, Xinxiang, Henan, 453003, China, Li L. ,   School of Life Sciences and Technology, Xinxiang Medical University, Xinxiang, Henan, 453003, China, Cui B. ,   School of Medicine, Hubei Polytechnic University, Huangshi 435003, China
Published: April 2022

The antibacterial mechanism of GO in solution have been well studied, however, the antibacterial activity of GO as coating material in solid phase is still unclear. Here, we report a direct proof of the antibacterial mechanisms of GO coatings. Oxidative stress induced by GO coating was found to be an important reason for the prevention of bacteria colonization on the coating surface, since a ROS dependent antibacterial effect was detected in this study. This finding could help with understanding bacteria-GO solid surface interaction and further designing such antibacterial implant surfaces.