2,652,229 results
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2. Material properties and water resistance of inorganic–organic polymer coated cellulose paper and nanopaper
- Author
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Amalie Solberg, Jennifer Zehner, Ferdinand Somorowsky, Klaus Rose, Antti Korpela, Kristin Syverud, and Publica
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Paper ,Nanopaper ,Polymers and Plastics ,Organic–inorganic polymers ,SDG 7 - Affordable and Clean Energy ,Cellulose ,Hydrophobic coating ,Tunable biodegradation - Abstract
Cellulose-based materials represent a renewable, biodegradable, and environmentally friendly alternative to plastic from fossil resources. Nanopaper is a strong and lightweight material formed from cellulose nanofibrils (CNFs). Paper and nanopaper have been considered as excellent alternatives to plastics for use in agriculture and for packaging applications. However, common for both paper and nanopaper is their hydrophilic character, and consequently, poor water-resistance properties. ORMOCER®s are a class of inorganic–organic polymers with excellent barrier and protective properties used for a range of coating applications. Here we present ORMOCER®-coated paper and nanopaper. The coated papers and nanopapers are characterized, both in terms of their morphology, hydrophobicity, and mechanical properties. We demonstrate that the pressure used during the pressing and drying of paper and nanopaper influence their tear and tensile—properties, and that the morphology of the coated nanopaper differs significantly from that of the coated paper. While the ORMOCER® was impregnated within the porous network of the paper, a well-defined two-layered morphology was obtained with the coated nanopaper. Further, the biodegradability of the nanopaper with and without coating was assessed. The degradation study demonstrated that both the pressure used during the pressing and drying of the nanopaper, and the composition of the ORMOCER®, influenced the rate of degradation. Taken together, ORMOCER®-coated paper and nanopaper are promising for the preparation of materials that are both water-resistant, renewable, and biodegradable.
- Published
- 2023
3. Phytochemical analysis and insecticidal activities of seed extracts from Oenanthe pimpinelloides L. treated paper samples vs. Tribolium castaneum
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Bildik Dal, Ahsen Ezel, Özdemir, Ayşe Daut, Gücüş, Mehmet Onurhan, Herouini, Amel, Kemassi, Abdellah, and Gücüş, Mehmet Onurhan
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Environmental Engineering ,Seed Extracts ,Tribolium Castaneum ,Bioengineering ,Oenanthe Pimpinelloides ,Waste Management and Disposal ,Paper Treatment - Abstract
WOS:000967659000009 The utilization of plant extraction products from Oeneanthe pimpinelloides (Apiaceae family) seeds were investigated in terms of their use as an insecticide control of packaging materials. The aim was to investigate their insecticidal effects against the flour beetle Tribolium castaneum. The Oeneanthe pimpinelloides seeds were extracted with methanol. By using the liquid-liquid extraction method, the hexane extract (II) was separated from the methanol extract (I) and hexane and methanol were evaporated. Then, the chemical composition of each sample was determined via gas chromatography–mass spectrometry. The methanol extract predominantly contained tetrahydrofuran, 1-methoxy-2-propanol, 1-methoxy, 2-butoxyethanol, 1-phenylethanone, cyclohexene carboxylate derivative, (3-phenyl-2-propynylidene) cyclopropane, diphenyldiazene, and dihydroxypropyl ester components, while the hexane fraction contained nonane, 1-octanol, decane, undecane, tridecane, alkyl benzene, benzene sulfonic acid, benzoxazine, and hexadecanoic acid components, as well as some derivatives of them. Each fraction was dissolved in DMSO for impregnation on filter paper. The insecticide effects of the paper samples were determined against Tribolium castneum. According to the results, the mortality started after 3 d for each fraction. After 4 d, the hexane fraction indicated total mortality in comparison with the methanol fraction, which showed partial mortality (3/5).
- Published
- 2023
4. Angle of the Perforation Line to Optimize Partitioning Efficiency on Toilet Papers
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Joana Costa Vieira, André Costa Vieira, Marcelo L. Ribeiro, Paulo T. Fiadeiro, and Ana Paula Costa
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FE model ,optimization ,perforation efficiency ,perforation line angle ,tissue toilet paper - Abstract
Currently, tissue product producers try to meet consumers’ requirements to retain their loyalty. In perforated products, such as toilet paper, these requirements involve the paper being portioned along the perforation line and not outside of it. Thus, it becomes necessary to enhance the behavior of the perforation line in perforated tissue papers. The current study aimed to verify if the perforation line for 0° (the solution found in commercial perforated products) is the best solution to maximize the perforation efficiency. A finite element (FE) simulation was used to validate the experimental data, where the deviations from the experiments were 5.2% for the case with a 4 mm perforation length and 8.8% for a perforation of 2 mm, and optimize the perforation efficiency using the genetic algorithm while considering two different cases. In the first case, the blank distance and the perforation line angle were varied, with the best configuration being achieved with a blank distance of 0.1 mm and an inclination angle of 0.56°. For the second case, the blank distance was fixed to 1.0 mm and the only variable to be optimized was the inclination angle of the perforation line. It was found that the best angle inclination was 0.67°. In both cases, it was verified that a slight inclination in the perforation line will favor partitioning and therefore the perforation efficiency.
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- 2023
5. From Paper Patterns to Patterns-on-Fabric: Home Sewing in Sweden, 1881–1981
- Author
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Gunilla Törnvall
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Cultural Studies ,Sweden ,tillskärningsmönster ,History ,garment production ,home sewing ,damtidningar ,klädproduktion ,General Business, Management and Accounting ,pattern magazines ,1900-talsmode ,hemsömnad ,mönstertidningar ,Sverige ,paper patterns ,dressmaking patterns ,twentieth-century fashion ,women's magazines ,Ethnology - Abstract
From the end of the nineteenth century and one hundred years onward, home sewing was an important part of many women’s duties, but it was also a pleasure, something that existed parallel with the emerging mass-produced ready-to-wear industry. The paper patterns used for home dressmaking were often sold and distributed through women’s magazines. These pattern sections were both a kind of reader service and a conscious strategy to capture the female target group. This article, based on an analysis of three Swedish magazines, is the first in-depth survey of patterns for home sewing of women’s clothes in Sweden. The study shows how the magazines adapted to changes in society with increasingly easier patterns and ready-cut fabric for their readers. By highlighting women making their clothes in the home, this article contributes to an often-neglected area of women’s memory and fashion history.
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- 2023
6. Resource papers as registered reports: a proposal
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Responsible resource development ,Proposal ,Collaborative enterprise ,Data collection plan ,NLP - Abstract
This is a proposal for publishing resource papers as registered reports in the Northern European Journal of Language Technology. The idea is that authors write a data collection plan with a full data statement, to the extent that it can be written before data collection starts. Once the proposal is approved, publication of the final resource paper is guaranteed, as long as the data collection plan is followed (modulo reasonable changes due to unforeseen circumstances). This proposal changes the reviewing process from an antagonistic to a collaborative enterprise, and hopefully encourages NLP resources to develop and publish more high-quality datasets. The key advantage of this proposal is that it helps to promote responsible resource development (through constructive peer review) and to avoid research waste.
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- 2023
7. Highly Crystalline Oxidase-like MnOOH Nanowire-Incorporated Paper Dipstick for One-Step Colorimetric Detection of Dopamine
- Author
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Kim, Phan Ba Khanh Chau, Thinh Viet Dang, and Moon Il
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paper dipstick ,MnOOH nanowires ,dopamine oxidase ,nanozyme ,colorimetric biosensors - Abstract
Developing a convenient detection method for dopamine holds a significant incentive due to its high clinical significance. Herein, we synthesize crystalline MnOOH nanowires (MNWs) via a simple solvothermal treatment of KMnO4 and demonstrate that they possess excellent oxidase-like activity owing to the presence of pure Mn3+ sites on the MNWs. Particularly, MNWs catalyze the rapid oxidation of dopamine into aminochromes, which show a vivid brown color. The dopamine oxidase-like activity of MNWs follows the typical Michaelis–Mentenkinetics with excellent storage stability. Based on the affirmative catalytic features, a paper dipstick incorporating MNWs in the detection zone is constructed for the one-step colorimetric detection of target dopamine. By immersing the dipstick into the sample solution for 30 min, the sample spontaneously moves to the detection zone due to capillary force, yielding a brown color proportional to the amount of dopamine, which is quantified from an image acquired using a smartphone. With the MNW-containing solution-based assay and MNW-incorporated paper dipstick, dopamine is successfully determined with high selectivity, sensitivity, and detection precision when using spiked human serum and pharmaceutical dopamine injection samples, respectively. Successful analytical values such as the dynamic linear ranges of 3–60 μM and 0.05–7 mM are achieved with the solution-based assay and paper dipstick, respectively, along with excellent detection accuracy (95–99%) and precision (1.0–3.1%). Hence, we developed a simple and efficient nanozyme-based paper dipstick biosensor for dopamine that can be used in point-of-care testing environments.
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- 2023
- Full Text
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8. Highly selective paper-based and colorimetric detection for arsenic(V) with methylene blue-functionalized gold nanoparticles
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Eunsoo Wi and Younghun Kim
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General Chemical Engineering - Published
- 2023
9. Tailoring the micro- and nanostructure of polymer-derived ceramic papers
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Johannes Peter, Emanuel Ionescu, and Hans-Joachim Kleebe
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Materials Chemistry ,Ceramics and Composites - Published
- 2023
10. Real, misreported, and backfilled adherence with paper sleep diaries
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Megan Clegg-Kraynok, Lauren Barnovsky, and Eric S. Zhou
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General Medicine - Published
- 2023
11. Removal of Pb (II) from Aqueous Solution by a Pectin-Producing Alga, Penium margaritaceum, Immobilized on Filter Paper
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Tsogjargal Byamba, Kazutoshi Hasegawa, and Isamu Maeda
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Microbiology (medical) ,lead ,unicellular alga ,pectin ,immobilization ,filter paper ,Molecular Biology ,Microbiology - Abstract
Lead (Pb) pollution from local mines and industrial use increases risks for human, animal, and plant health. Pectin is an effective chelator of Pb, and it has been shown that a unicellular green alga, Penium margaritaceum, synthesizes pectin in the cell wall. In this study, the ability of P. margaritaceum to remove Pb from an aqueous solution was investigated. Energy dispersive X-ray spectroscopy revealed that two strains of P. margaritaceum accumulated Pb on the cell surface. Hence, P. margaritaceum cells were immobilized on cellulose filter paper. The immobilized algal cells were soaked in 1.0 mg/L Pb solution with gentle shaking for 8 h, and Pb in the solution and on the filter paper was measured by flame atomic absorption spectrometry. The immobilized algal cells continuously decreased the Pb concentration to less than 0.5 mg/L and recovered 31.8–32.7% of added Pb. The specific decrease in Pb and increase in Ca were observed in the presence of 1.0 mg/L each of Ca, Mg, Na, and K. Fourier transform infrared spectra suggested that the carboxylic acid group would be responsible for the adsorption of Pb. This study is the first to demonstrate the effectiveness of the immobilized P. margaritaceum cell in removing Pb from aqueous solutions with simple solid–liquid separation.
- Published
- 2022
12. Making paper from materials that are essential to our lives/making paper without trees is the new 'Must'
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Carmen-Alice Teacă
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Environmental Engineering ,Bioengineering ,Waste Management and Disposal - Abstract
Paper, which is in fact a very complex cellulose-based product derived from different lignocellulosic resources, is usually regarded as a simple omnipresent commodity in our lives. Wood fibers derived from trees are the most employed sources for papermaking purposes. From an environmental protection perspective, and for their essential role in our life (they give us the life itself through their foliar system supporting the photosynthesis process), trees should not be extensively cut down and they should be used less and less for papermaking. Thus, employment of non-woody alternative sources for papermaking could be exploited more as an attractive and feasible option.
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- 2023
13. Physicians’ responsibility toward environmental degradation and climate change: A position paper of the European Federation of Internal Medicine
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Luís Campos, J. Vasco Barreto, Stefano Bassetti, Monica Bivol, Amie Burbridge, Pietro Castellino, João Araújo Correia, Mine Durusu-Tanriöver, Carmen Fierbinteanu-Braticevici, Thomas Hanslik, Zbigniew Heleniak, Radovan Hojs, Leonid Lazebnic, Maria Mylona, Matthias Raspe, João Queirós e Melo, Filomena Pietrantonio, Reinold Gans, Runólfur Pálsson, Nicola Montano, Ricardo Gómez-Huelgas, Dror Dicker, Lifelong Learning, Education & Assessment Research Network (LEARN), and Groningen Kidney Center (GKC)
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Greenhouse Gases ,Climate Change ,Physicians ,Ecological health footprint ,Internal Medicine ,Humans ,Environment ,EFIM position paper ,Hospitals - Abstract
The current data on climate change and environmental degradation are dramatic. The consequences of these changes are already having a significant impact on people's health. Physicians - as advocates of the patients, but also as citizens - have an ethical obligation to be involved in efforts to stop these changes. The European Federation of Internal Medicine (EFIM) strongly encourages the Internal Medicine societies and internists across Europe to play an active role in matters related to climate change and environmental degradation. At a national level, this includes advocating the adoption of measures that reduce greenhouse gas (GHG) emissions and environmental degradation and contributing to policy decisions related to these issues. At a hospital level and in clinical practice, supporting actions by the health sector to reduce its ecological footprint is vital. At the level of EFIM and its associated internal societies, promoting educational activities and developing a toolkit to prepare internists to better care for citizens who suffer from the consequences of climate change. In addition to advocating and implementing effective actions to reduce the ecological footprint of the health industry, recommending the introduction of these themes in scientific programs of Internal Medicine meetings and congresses and the pre- and postgraduate medical training. At a personal level, internists must be active agents in advocating sustainable practices for the environment, increasing the awareness of the community about the health risks of climate change and environmental degradation, and being role models in the adoption of environmentally friendly behaviour.
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- 2022
14. Migration behavior of photoinitiators in polyethylene-coated paper for takeaway fast food
- Author
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Yingtong Wu, Jifeng Lang, Guangfa Liu, Lijun Wang, Haiyan Song, and Chongxing Huang
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Agronomy and Crop Science ,Food Science - Abstract
The migration of photoinitiators (PIs): benzophenone (BP), ethyl 4-dimethylaminobenzoate (EDAB), and 4-chlorobenzophenone (CBP), from polyethylene (PE)-coated paper to 4% (v/v) acetic acid and 10% (v/v) salt-simulated food solution was quantitatively analyzed using gas chromatography–mass spectrometry. The migration behavior of the three PIs was studied under three specific working conditions: conventional heating, microwave power, and random vibration level. The migration rate of the three PIs in acidic food simulants was ranked from BP > EDAB > CBP under the specific working conditions. The mobility of the three PIs increased with increasing temperature, microwave power, and random vibration acceleration in 4% (v/v) acetic acid by 10, 10, and 15%, respectively. The experimental migration data of three PIs in PE-coated paper under different temperatures and microwave powers were used to establish the Crank monolayer migration model according to Fick’s second law. The diffusion coefficient D increased with an increase in experimental conditions. According to the migration data under the condition of random vibration level, a mathematical model conforming to the Fick model was established, fitting the migration process. These results showed that conventional heating, microwave heating, and vibration could affect the food safety of PE-coated paper.
- Published
- 2023
15. AI Machine Vision based Oven White Paper ColorClassification and Label Position Real-time Monitoring System to Check Direction
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Hee-Chul Kim, Youn-Saup Yoon, and Yong-Mo Kim
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General Medicine - Abstract
We develop a vision system for batch inspection by oven white paper model color by manufacturing a machine vision system for the oven manufacturing automation process. In the vision system, white paper object detection (spring), color clustering, and histogram extraction are performed. In addition, for the automated process of home appliances, we intend to develop an automatic mold combination detection algorithm that inspects the label position and direction (angle/coordinate) using deep learning.
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- 2023
16. Technological aspects of dental education: will we still be reading a paper journal in 50 years?
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Damien A Walmsley and Marco Antonio Dias da Silva
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General Dentistry - Abstract
Change has become the norm and with the digital revolution we are seeing the demise of the printed word. Dentistry is a pictorial subject, but will pictures in a textbook or journal be surpassed by accessing digital ones on a screen? This article reviews the rapidly changing access and reading of dental publications. An argument is that the ease of access to electronic material, such as video and podcasts, may make traditional paper-based publications obsolete. Already dentistry is seeing such changes take place. With such revolutions come challenges. Misinformation is much easier to generate, and the evidence base may be diluted. Furthermore artificial intelligence is now able to produce text and papers that will make it more difficult to critically review the dental content on offer. The future will bring many challenges and this article provides an opinion on what dentistry might expect. CPD/Clinical Relevance: There are challenges posed by the increasing use of digital resources for information and how this might impact dental knowledge.
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- 2023
17. Top 100 Most-Cited Papers in Herpes Zoster from 2000 to 2022: A Bibliometric Study
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Ning Gao, Meng Li, Weiming Wang, Lei Wang, Zhen Liu, and Yufeng Guo
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Anesthesiology and Pain Medicine ,Journal of Pain Research - Abstract
Ning Gao,1,* Meng Li,2,* Weiming Wang,1 Lei Wang,3 Zhen Liu,4 Yufeng Guo1 1Department of Acupuncture and Moxibustion, Guangâanmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, Peopleâs Republic of China; 2Department of Gastroenterology, Guangâanmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, Peopleâs Republic of China; 3Department of Dermatology, China-Japan Friendship Hospital, Beijing, 100020, Peopleâs Republic of China; 4Department of Gastroenterology, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, 100091, Peopleâs Republic of China*These authors contributed equally to this workCorrespondence: Zhen Liu, Department of Gastroenterology, Xiyuan Hospital, China Academy of Chinese Medical Sciences, No. 1 Xiyuan Playground, Haidian District, Beijing, Peopleâs Republic of China, Email doctorliuzhen@126.com Yufeng Guo, Department of Acupuncture and Moxibustion, Guangâ an Men Hospital, China Academy of Chinese Medical Sciences, No. 5 Beixiange St., Xicheng District, Beijing, Peopleâs Republic of China, Email gamgyf@139.comBackground: In recent years, the incidence of herpes zoster has risen steeply, the exact pathogenesis of the acute pain and the transformation into postherpetic neuralgia are still obscure, and the absence of effective management remains a major therapeutic challenge. The purpose of this study was to perform a qualitative and quantitative bibliometric analysis of the 100 most cited papers on herpes zoster.Materials and methods: Related literature were retrieved from the Web of Science Core Collection. Excel and VOSviewer software were applied to quantitatively analyze, and construct the bibliometric network charts.Results: The Top 100 most-cited papers published between 2000 and 2018 showed a fluctuating downward trend. The most studies were published in the year of 2000 (n = 12). The article entitled âA vaccine to prevent herpes zoster and postherpetic neuralgia in older adultsâ from Oxman MN, was the most-cited publication. The United States was the most contributing country, followed by the United Kingdom, and Italy. Finland occupied the highest citations per publication (CPP). The University of Colorado topped the list of institutions with the most publications with 18 articles and also had the most citations (average citations: 281.78 per article). Myron J Levin from the University of Colorado School of Medicine is the most published and most cited researcher overall, whereas Duke Universityâs John W Gnann tops the list in terms of average CPP.Conclusion: In terms of the quantity of T100 articles, researchers, and organizations, the US is the predominant country. The most T100 papers were published in the special journal Clinical Infectious Diseases. The most academic focus remain the remedies for postherpetic neuralgia and vaccine development for individualized groups.Keywords: herpes zoster, bibliometric study, top-cited, citation, VOSviewer
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- 2023
18. PAMAM-Functionalized Paper as a New Substrate for the Paper Spray Mass Spectrometry Measurement of Proteins
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Igor Pereira, Joseph Monaghan, Lucas R. Abruzzi, and Chris G. Gill
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Analytical Chemistry - Published
- 2023
19. Surface characterization of paper products by profilometry with a fractal dimension analysis
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Yong Ju Lee, Young Chan Ko, Byoung Geun Moon, and Hyoung Jin Kim
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Environmental Engineering ,Bioengineering ,Waste Management and Disposal - Abstract
A surface profilometry technique was used to characterize the surfaces of paper products. A stylus-contact type profilometer capable of simultaneously generating both surface roughness- and friction-profiles was used. As a stylus for the profilometer, a conical shape whose tip was rounded to have a 0.5 mm curvature radius was designed and successfully employed in both printing & writing (P&W) papers and hygiene papers such as bathroom tissues and kitchen towel. From the profiles, the mean absolute deviation (MAD) from the averages, i.e., R-MAD from the roughness average and F-MAD from the average coefficient of friction, were suggested as the new surface characterization parameters. To elucidate the surface roughness profiles by fractal dimension analysis, the variogram method was applied to get the fractal dimensions of the paper products. Generally, the value of the fractal dimension increased as the surface roughness increased. The surface profilometry technique with the fractal dimension analysis with the variogram method looks promising to gain additional insight on the surface characteristics of paper products.
- Published
- 2023
20. Evaluating the content validity of the undergraduate summative exam question papers of Forensic Medicine & Toxicology from 6 medical universities in India
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Vijay Kautilya Dayanidhi, Arijit Datta, Shruti P Hegde, and Preeti Tiwari
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Reviews and References (medical) ,Medicine (miscellaneous) ,Health Professions (miscellaneous) ,Education - Abstract
Introduction: Summative assessments play a major role in shaping the student’s learning. There is little literature available on validity of summative assessment question papers in Forensic Medicine & Toxicology. This study analyses 30 question papers from 6 reputed universities for content validity. Methods: A retrospective cross-sectional record-based observational study was conducted where 30 university summative question papers in Forensic Medicine & Toxicology from 6 universities across India were evaluated for content validity. The learning domain assessed, the type of questions asked, and sampling of the content was compared and presented in the results. Results: From the results of the study, it was noted that 80% weightage was allotted to recall in most papers and only one paper tested for application. 70 to 80% of the marks were allotted to Forensic Pathology leading to disproportionate sampling. Core areas in Toxicology and Medical Jurisprudence were sparsely assessed. Conclusion: The content validity of the summative question papers in Forensic Medicine and Toxicology was unsatisfactory, emphasising the need for evaluation of the clarity and efficacy of the blueprints being used by the universities. Faculty training to motivate and influence a change in the mindset is necessary to bring about a course correction.
- Published
- 2023
21. Shredding Paper: The Rise and Fall of Maine's Mighty Paper Industry, by Michael Hillard (Ithaca: Cornell, 2021)
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Richard McIntyre
- Subjects
Sociology and Political Science - Published
- 2023
22. Microfluidic flow modulation with digitized sizing pattern in Xuan paper-based analytical devices
- Author
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Jose H. Lizama, Hsiu-Yang Tseng, Yi-Wei Shen, and Chiu-Jen Chen
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Alum-glue ,Paper-based microfluidics ,Wicking profile ,General Engineering ,Flow modulation ,TA1-2040 ,Xuan paper ,Engineering (General). Civil engineering (General) ,Patternability - Abstract
Spatially resolved fluid-flow modulation and its corresponding integration becomes a crucial aspect to consider when designing high-performing paper-based analytical devices. As such, high demand exists for cost-effective techniques able to selectively control flow in patternable regions of the device. In this regard, a solution composed of potassium alum and animal glue; sizing materials used in the fabrication of calligraphy Xuan paper, is successfully adapted for the first time in a revolutionary approach to efficiently modulate the capillary flow in paper microfluidic channels. Flow delays are achieved by coating the substrate systematically through the variation of parameters such as the ratio of alum to glue, the concentration of alum-glue in the solution, and the number of subsequent coating layers of alum-glue. Moreover, digitized patterning with alum-glue is developed to achieve programmable wicking profiles of accelerating, decelerating, and quasi-linear flow displacement by alternating coated and uncoated zones in the channel. Additionally, the influence of alum-glue when performing biometric assays is investigated by performing a horseradish peroxidase activity colorimetric assay and found to have negligible effects on reading, where a negligible difference of 5.2% was observed in an assay performed in a coated paper substrate, compared to an uncoated one.
- Published
- 2022
23. Unique Dye-Sensitized Solar Cell Using Carbon Nanotube Composite Papers with Gel Electrolyte
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Oya, Yi Kou and Takahide
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carbon nanotube (CNT) ,carbon nanotube composite paper ,dye-sensitized solar cell (DSSC) ,paper DSSC ,gel electrolyte - Abstract
We propose a unique form of dye-sensitized solar cells (DSSCs), paper DSSCs based on carbon-nanotube (CNT) composite papers, and the use of a gel electrolyte for the paper DSSC. In our previous study, we succeeded in developing the paper DSSC. However, its performance and lifetime were not sufficient. We considered that the problem was the use of liquid-type electrolyte. To improve the performance of the paper DSSC, a gel electrolyte was introduced to increase safety and durability. Here, a polymer gel electrolyte was synthesized using a copolymer of polyethylene glycol (PEG) and polyvinylidene fluoride (PVDF) as a matrix, mixed with iodine and potassium iodide. The resulting paper DSSC had a fill factor (FF, a performance indicator) of 0.248 and a conversion efficiency of 2.43 × 10−5% with an extended working time (lifetime) of more than 110 min. Further modifications were made to the metallic CNT composite paper and the gel electrolyte, resulting in an increased conversion efficiency of 2.02 × 10−3%. This study suggests the potential of gel electrolytes in enhancing the performance of paper DSSCs, providing new insights for their future applications.
- Published
- 2023
- Full Text
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24. Development of New Accelerated Aging Test for Comparison of the Quality of Different Insulating Papers Based on Cellulose
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Lukic, Draginja Mihajlovic, Valentina Vasovic, and Jelena
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aging test ,Kraft paper ,thermally upgraded paper - Abstract
The aim of this study is to propose a test method for the determination of the quality of transformer paper insulation. For this purpose, the oil/cellulose insulation systems were exposed to various accelerated aging tests. The results of the aging experiments of normal Kraft and thermally upgraded papers, two different types of transformer oil (mineral and natural ester), and copper are shown. Aging was carried out in various experiments at 150 °C, 160 °C, 170 °C, and 180 °C with dry (initial values ≤ 0.5%) and moistened cellulose insulation (initial values 3–3.5%). Following insulating oil and paper, degradation markers were measured: the degree of polymerization, tensile strength, furan derivates, methanol/ethanol, acidity, interfacial tension, and dissipation factor. It was found that the aging of cellulose insulation in cycles was 1.5–1.6 times faster in comparison to continuous aging, due to the more pronounced effect of hydrolytic mechanism in cyclic aging owing to the produced and absorbed water. Furthermore, it was observed that the high initial water content in cellulose increases the aging rate two to three times more than in the dry experimental setup. The proposed aging test in cycles can be used to achieve faster aging and to compare the quality of different insulating papers.
- Published
- 2023
- Full Text
- View/download PDF
25. Paper-Based Bi-Material Cantilever Actuator Bending Behavior and Modeling
- Author
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Gordon Chen, Ashutosh Kumar, Hojat Heidari-Bafroui, Winfield Smith, Amer Charbaji, Nassim Rahmani, Constantine Anagnostopoulos, and Mohammad Faghri
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Control and Systems Engineering ,Mechanical Engineering ,paper-based sensor ,bi-material cantilever ,paper-based valve ,bending response ,Electrical and Electronic Engineering - Abstract
In this paper, the behavior of the Bi-Material Cantilever (B-MaC) response deflection upon fluidic loading was experimentally studied and modeled for bilayer strips. A B-MaC consists of a strip of paper adhered to a strip of tape. When fluid is introduced, the paper expands while the tape does not, which causes the structure to bend due to strain mismatch, similar to the thermal loading of bi-metal thermostats. The main novelty of the paper-based bilayer cantilevers is the mechanical properties of two different types of material layers, a top layer of sensing paper and a bottom layer of actuating tape, to create a structure that can respond to moisture changes. When the sensing layer absorbs moisture, it causes the bilayer cantilever to bend or curl due to the differential swelling between the two layers. The portion of the paper strip that gets wet forms an arc, and as the fluid advances and fully wets the B-MaC, the entire B-MaC assumes the shape of the initial arc. This study showed that paper with higher hygroscopic expansion forms an arc with a smaller radius of curvature, whereas thicker tape with a higher Young’s modulus forms an arc with a larger radius of curvature. The results showed that the theoretical modeling could accurately predict the behavior of the bilayer strips. The significance of paper-based bilayer cantilevers lies in their potential applications in various fields, such as biomedicine, and environmental monitoring. In summary, the novelty and significance of paper-based bilayer cantilevers lie in their unique combination of sensing and actuating capabilities using a low-cost and environmentally friendly material.
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- 2023
- Full Text
- View/download PDF
26. Rapid Assembly of Cellulose Microfibers into Translucent and Flexible Microfluidic Paper-Based Analytical Devices via Wettability Patterning
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Peng Ma, Shanshan Wang, Jie Wang, Yu Wang, Yue Dong, Shunji Li, Huiying Su, Peng Chen, Xiaojun Feng, Yiwei Li, Wei Du, and Bi-Feng Liu
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Paper ,Glucose ,Lab-On-A-Chip Devices ,Microfluidics ,Wettability ,Humans ,Microfluidic Analytical Techniques ,Cellulose ,Analytical Chemistry - Abstract
Microfluidic paper-based analytical devices (μPADs) are emerging as powerful analytical platforms in clinical diagnostics, food safety, and environmental protection because of their low cost and favorable substrate properties for biosensing. However, the existing top-down fabrication methods of paper-based chips suffer from low resolution (200 μm). Additionally, papers have limitations in their physical properties (e.g., thickness, transmittance, and mechanical flexibility). Here, we demonstrate a bottom-up approach for the rapid fabrication of heterogeneously controlled paper-based chip arrays. We simply print a wax-patterned microchip with wettability contrasts, enabling automatic and selective assembly of cellulose microfibers to construct predefined paper-based microchip arrays with controllable thickness. This paper-based microchip printing technology is feasible for various substrate materials ranging from inorganic glass to organic polymers, providing a versatile platform for the full range of applications including transparent devices and flexible health monitoring. Our bottom-up printing technology using cellulose microfibers as the starting material provides a lateral resolution down to 42 ± 3 μm and achieves the narrowest channel barrier down to 33 ± 2 μm. As a proof-of-concept demonstration, a flexible paper-based glucose monitor is built for human health care, requiring only 0.3 μL of sample for testing.
- Published
- 2022
27. Current approaches and challenges of sample preparation procedures for the safety assessment of paper and cardboard food contact materials: A comprehensive review
- Subjects
OF-THE-ART ,sample preparation ,MIGRATION ,BOARD ,food contact chemicals ,SUBSTANCES ,food contact materials ,MINERAL-OIL HYDROCARBONS ,DRY FOODS ,CHEMICAL-ANALYSIS ,paper and cardboard ,CONTAMINANTS ,PACKAGING MATERIALS ,food packaging ,RECYCLED PAPERBOARD - Abstract
In the European Union (EU), Regulation (EC) 1935/2004 provides a harmonized legal EU framework and sets out the general principles for safety and inertness for all Food Contact Materials (FCMs) and Food Contact Articles. From a food safety point of view, however, specific EU legislation for paper and cardboard FCMs is lacking, while at Member State level, national legislation differs among countries. More than 11,000 chemicals have been identified in all types of FCMs, most of them without any information on toxicity or migration potential from FCM to food. The present review shows a wide variability of protocols, approaches, and conditions used in scientific studies, which are difficult to compare. In this regard, procedures and conditions laid down in EU legislation for plastics and European Standards (EN protocols) may serve as a good basis for the future sample preparation procedures in the framework of paper and cardboard FCMs safety assessment. Challenges on sample preparation procedures are presented involving the interlinked steps of sample preparation, conditions used and their impact in chemical analysis and in vitro bioassay testing. Currently, there is no general consensus on the criteria for structuring, evaluating, and tuning sample preparation procedures for paper and cardboard FCMs. For this purpose, a set of modified criteria and a decision tree are proposed based on the literature. Along this, mass transfer processes occurring in paper and cardboard FCMs and parameters affecting chemical migration need to be accounted for prior to reaching general consensus on criteria for sample preparation procedures.
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- 2022
28. Laser-induced graphene from paper for non-enzymatic uric acid electrochemical sensing in urine
- Author
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Bohdan Kulyk, Sónia O. Pereira, António J.S. Fernandes, Elvira Fortunato, Florinda M. Costa, Nuno F. Santos, CENIMAT-i3N - Centro de Investigação de Materiais (Lab. Associado I3N), DCM - Departamento de Ciência dos Materiais, and UNINOVA-Instituto de Desenvolvimento de Novas Tecnologias
- Subjects
Flexible electronics ,Chemistry(all) ,Materials Science(all) ,SDG 3 - Good Health and Well-being ,Electrochemical biosensors ,Paper-LIG ,SDG 13 - Climate Action ,General Materials Science ,Human urine ,General Chemistry ,Graphene ,Uric acid - Abstract
This work was developed within the scope of project i3N (LA/P/0037/2020. I.P. N. F. Santos thanks i3N for the BPD Grant BPD/UI96/5177/2020. S. O. Pereira thanks i3N for the BPD Grant BPD/UI96/5808/2017. The authors also thank Jonas Deuermeier for the XPS measurements. Publisher Copyright: © 2022 Elsevier Ltd Laser-induced graphene from paper (paper-LIG) was applied in non-enzymatic electrochemical sensing of uric acid (UA) in human urine. Paper-LIG was formed by CO2 laser modification of paper into a 3D graphene arrangement. Kinetic analysis of paper-LIG electrodes returned effective heterogeneous electron transfer standard rate constants of 1.4 × 10−3 cm s−1 and 7.8 × 10−4 cm s−1 for [Ru(NH3)6]2+/3+ and [Fe(CN)6]4−/3− redox probes, respectively. These electrodes were able to detect and quantify uric acid in PBS within the 10–300 μM range at pH between 5.6 and 7.4. At pH 7.4, a linear response (R2 = 0.999) from 10 to 250 μM was achieved, with a limit of detection of 3.97 μM and a sensitivity of 0.363 μA cm−2 μM−1. Paper-LIG electrodes denoted adequate selectivity in synthetic urine as well as in ascorbic acid (AA) and dopamine (DA)-containing electrolytes. Determination of urinary UA content in human samples returned a concentration of c.a. 1.8–1.9 mM, within the range for healthy individuals. Recoveries of samples spiked with 50 and 100 μM UA were 100.6% and 95.4%, respectively, with satisfactory reproducibility and stability. These cheap, lightweight, flexible, and eco-friendly paper-LIG biosensors for non-enzymatic quantification of UA in human urine pave the way to widespread application in the detection of other important biomarkers. publishersversion published
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- 2022
29. Current approaches and challenges of sample preparation procedures for the safety assessment of paper and cardboard food contact materials: A comprehensive review
- Author
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Misha Vrolijk, Athanasios Kourkopoulos, and Dick Sijm
- Subjects
OF-THE-ART ,Food Safety ,sample preparation ,MIGRATION ,BOARD ,Food Contamination ,food contact chemicals ,SUBSTANCES ,Allergens ,food contact materials ,MINERAL-OIL HYDROCARBONS ,DRY FOODS ,CHEMICAL-ANALYSIS ,paper and cardboard ,CONTAMINANTS ,European Union ,PACKAGING MATERIALS ,Plastics ,food packaging ,Food Science ,RECYCLED PAPERBOARD - Abstract
In the European Union (EU), Regulation (EC) 1935/2004 provides a harmonized legal EU framework and sets out the general principles for safety and inertness for all Food Contact Materials (FCMs) and Food Contact Articles. From a food safety point of view, however, specific EU legislation for paper and cardboard FCMs is lacking, while at Member State level, national legislation differs among countries. More than 11,000 chemicals have been identified in all types of FCMs, most of them without any information on toxicity or migration potential from FCM to food. The present review shows a wide variability of protocols, approaches, and conditions used in scientific studies, which are difficult to compare. In this regard, procedures and conditions laid down in EU legislation for plastics and European Standards (EN protocols) may serve as a good basis for the future sample preparation procedures in the framework of paper and cardboard FCMs safety assessment. Challenges on sample preparation procedures are presented involving the interlinked steps of sample preparation, conditions used and their impact in chemical analysis and in vitro bioassay testing. Currently, there is no general consensus on the criteria for structuring, evaluating, and tuning sample preparation procedures for paper and cardboard FCMs. For this purpose, a set of modified criteria and a decision tree are proposed based on the literature. Along this, mass transfer processes occurring in paper and cardboard FCMs and parameters affecting chemical migration need to be accounted for prior to reaching general consensus on criteria for sample preparation procedures.
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- 2022
30. Silver nanoparticle inkjet-printed multiband antenna on synthetic paper material for flexible devices
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Hattan F. Abutarboush
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Materials for antennas ,Multiband antenna ,Flexible antenna ,General Engineering ,Silver nanoparticles ,TA1-2040 ,Paper antenna ,Engineering (General). Civil engineering (General) ,Inkjet-printed antenna - Abstract
Flexible inkjet-printed antenna is presented. The proposed antenna is designed on a synthetic paper substrate with an area of 35 × 40 mm2 to provide frequency bands for many popular wireless applications. Simulation and measurement are used to study the performances, including the frequency bands, radiation patterns, peak gains and efficiency, of the antenna in two severely bending conditions with a curvature radius of 20 mm in the forward and backward directions. The antenna printed in photo papers material could not be fully flexible due to cracks introduced to the coating material on the surface of the photo paper. Hence, the resin coated material was only suitable for curved devices. The synthetic paper material used in this paper does not have a resin coating, therefore, the antenna does not lose its flexibility and can be bent in both the forward and backward directions without any cracks. Results show that bending in these two conditions has insignificant effects on the performances of the antenna. With a curvature radius of 20 mm in the forward direction, the measured peak gain and efficiency of the antenna are in the ranges from −3 to +2 dBi and 40% to 60%, respectively. The results together with the low cost make the antenna most suitable for many flexible 5G communications devices.
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- 2022
31. Three Years, Two Papers, One Course Off: Optimal Nonmonetary Reward Policies
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Shivam Gupta, Wei Chen, Milind Dawande, and Ganesh Janakiraman
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Strategy and Management ,Management Science and Operations Research - Abstract
We consider a principal who periodically offers a fixed and costly nonmonetary reward to agents to incentivize them to invest effort over the long run. An agent’s output, as a function of his effort, is a priori uncertain and is worth a fixed per-unit value to the principal. The principal’s goal is to design an attractive reward policy that specifies how the rewards are to be given to an agent over time based on that agent’s past performance. This problem, which we denote by [Formula: see text], is motivated by practical examples from both academia (e.g., a reduced teaching load) and industry (e.g., “Supplier of the Year” awards). The following “limited-term” (LT) reward policy structure has been quite popular in practice. The principal evaluates each agent periodically; if an agent’s performance over a certain (limited) number of periods in the immediate past exceeds a predefined threshold, then the principal rewards him for a certain (limited) number of periods in the immediate future. When agents’ outputs are deterministic in their efforts, we show that there always exists an optimal policy that is an LT policy and also, obtain such a policy. When agents’ outputs are stochastic, we show that the class of LT policies may not contain any optimal policy of problem [Formula: see text] but is guaranteed to contain policies that are arbitrarily near optimal. Given any [Formula: see text], we show how to obtain an LT policy whose performance is within ϵ of that of an optimal policy. This guarantee depends crucially on the use of sufficiently long histories of the agents’ outputs. We also analyze LT policies with short histories and derive structural insights on the role played by (i) the length of the available history and (ii) the variability in the random variable governing an agent’s output. We show that the average performance of these policies is within 5% of the optimum, justifying their popularity in practice. We then introduce and analyze the class of “score-based” reward policies; we show that this class is guaranteed to contain an optimal policy and also, obtain such a policy. Finally, we analyze a generalization in which the principal has a limited number for rewards in any given period and show that the class of score-based policies, with modifications to accommodate the limited availability of the rewards, continues to contain an optimal solution for the principal. This paper was accepted by Jeannette Song, operations management. Supplemental Material: The online appendix is available at https://doi.org/10.1287/mnsc.2022.4482 .
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- 2023
32. A 2D CELLULAR AUTOMATON MODEL OF LIQUID ABSORPTION INTO PAPER FIBERS WITH HYDROPHOBIC TREATMENT
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VÍTĚZSLAV KŘÍŽ, HANA KŘÍŽOVÁ, MARTIN KOCICH, and JOHANA DALÍKOVÁ
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Polymers and Plastics ,Materials Science (miscellaneous) ,Chemical Engineering (miscellaneous) ,Business and International Management - Abstract
In this work, the issue of applying water or a homogeneous aqueous suspension with a uniform size of (nano)particles (e.g., ink) to the surface of SBSK (southern bleached softwood kraft) paper with randomly arranged local hydrophobic treatment is investigated and then simulated. Based on the two investigated models, various simulation approaches were compared, an own simulation model was created, and its validity was subsequently demonstrated on the experiments performed.
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- 2023
33. High Prevalence of Causal Language and Inferences in Observational Hip and Knee Arthroplasty Database Studies: A Review of Papers Published Across Four Orthopaedic Journals
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Nadim Barakat, Wendy M. Novicoff, Brian C. Werner, and James A. Browne
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Orthopedics and Sports Medicine - Abstract
The use of administrative databases and clinical registries in lower extremity arthroplasty research is growing. Such observational studies are unable to fully control for confounders and cannot establish causality. However, many authors use causal language when describing their aims or findings, potentially misleading readers. We examined the prevalence of causal language and inferences in the lower extremity arthroplasty literature.We systematically identified administrative database and registry studies on hip and knee arthroplasty that were published in 4 orthopaedic journals in 2020. Papers were graded independently by two reviewers for the presence of causal language in both the title and abstract as well as the full text. Chi-squared analyses were conducted to determine the relationship between the causality grading and article characteristics including the journal of publication.Of 116 eligible articles, we classified 79.3% of titles and abstracts as either consistently causal or inconsistently causal, with only 20.7% as consistently non-causal. A total of 40.5% of full texts were consistently causal, 49.1% were inconsistent, and 10.3% were consistently non-causal. Chi-squared analyses revealed no statistically significant association between the title and abstract's grading and the journal (p = .720), nor with the use of a database or registry (p = .716).Causal language and inferences were present in 79.3% of titles and abstracts of lower extremity arthroplasty observational database studies published in 2020. The high prevalence of causal language and inferences in the arthroplasty literature may mislead readers.
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- 2023
34. Preparation and characterization of cellulose nanocrystals from paper mulberry fibers
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Hae Min Jo, Soo Hyun Lee, and Ji Young Lee
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Environmental Engineering ,Bioengineering ,Waste Management and Disposal - Abstract
The applicability of paper mulberry fiber (PM-FB), which is bast fiber, for manufacturing cellulose nanocrystals (CNCs) with high-yield was investigated. The PM-FB and hardwood bleached kraft pulp (Hw-BKP) were hydrolyzed under different sulfuric acid concentrations, reaction times, and reaction temperatures. The dependence of the CNC yield on the hydrolysis conditions and crystallinity of the raw materials was analyzed. The functional groups of the CNCs and their zeta potentials were determined. The fiber length and width of the individual CNCs were determined by transmission electron microscopy image analysis. The PM-FB showed a higher crystallinity of 86.8% compared to that of Hw-BKP and exhibited a high CNC yield of 55% under strong hydrolysis conditions. The sulfate group was introduced into the CNCs, which increased their negative charge. The fiber width of PM-FB-based CNCs (PM-CNCs) was larger than that of Hw-BKP-based CNCs (Hw-CNCs), and the aspect ratio ranged from 29.0 to 12.2 depending on the hydrolysis conditions. The yield of PM-CNCs was higher than that of Hw-CNCs under the same hydrolysis conditions. In addition, both CNCs exhibited similar quality. Therefore, PM-FB is a promising raw material for efficient CNC manufacturing.
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- 2023
35. Special collection of invited original research papers on 'Contributions by women in theory and applications of artificial intelligence'
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Maria Virvou, George A. Tsihrintzis, Gloria Phillips-Wren, and Lakhmi C. Jain
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Human-Computer Interaction ,Artificial Intelligence ,Computer Vision and Pattern Recognition ,Software - Abstract
Artificial Intelligence research is presenting phenomenal progress in two directions: (i) new theories and methodologies, and (ii) applications that expand traditional domains with innovative interventions. As indicated by recent reports, this progress has created a disequilibrium, where demand for scientists with skills in Artificial Intelligence is not fulfilled, a trend that will intensify further in the years to come. A potential solution to this shortage of specialised workforce may come from encouraging more women to get educated and follow a career in one of the Artificial Intelligence areas. This special collection of invited papers is dedicated to all women researchers and practitioners in Artificial Intelligence and coincides with the March 8, 2023 International Women’s Day. Moreover, it has two specific goals: (i) to inspire more women to study and practice Artificial Intelligence through presentation of recognized women researchers who can act as role models, and (ii) to highlight some streamlined research areas of Artificial Intelligence.
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- 2023
36. Recognition of conspecific immunological status in a neotropical paper wasp
- Author
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André Rodrigues de Souza, Wilson França, Amanda Prato, Markus J Rantala, and Fábio Santos do Nascimento
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Animal Science and Zoology ,Ecology, Evolution, Behavior and Systematics - Abstract
Host immune activation is common under a pathogen invasion. This physiological response can promote changes in the body surface compounds, thus providing chemical cues related to health that might be useful to conspecifics. By recognizing the current immunological status of social partners, individuals can modulate their behavior to minimize the risk of infection. Tegument wounding, an immune elicitor, is a required step for many parasites to become established in a host. By using the neotropical eusocial paper wasp Mischocyttarus metathoracicus as a model organism, we first performed a lure presentation experiment in the field to test if wasps discriminate conspecific immunological status (experimentally manipulated by wounding) during on nest social interactions. Then, we performed gas chromatography–mass spectrometry analyses to test if immunostimulation by wounding alters the wasps’ cuticular hydrocarbon profile. We found that wasps reduce the duration of aggressive physical contact when interacting with wounded lures, despite displaying a similar frequency of inspective and aggressive behaviors toward both the wounded and the control lures. Besides, we found a subtle increase in a single cuticular hydrocarbon in the wounded wasps. Thus, wasps recognize conspecific immunological status, likely by chemical cues, and modulate their behavior in order to defend the colony against intruders while minimizing the personal risk of infection.
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- 2023
37. High Performance of Paper Strength and Energy Savings in OCC Pulp Papermaking via MFC Addition
- Author
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Hui Cai, Jiulong Sha, Changsheng Lu, Wenlun Qiu, Junjie Liu, and Yang Liu
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Biomaterials ,Materials Science (miscellaneous) ,Chemical Engineering (miscellaneous) ,Forestry - Published
- 2023
38. Producing flexible calcium carbonate from waste paper and their use as fillers for high bulk paper
- Author
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Lae Hyuk Kang, Yung Bum Seo, and Jung Soo Han
- Subjects
Environmental Engineering ,Bioengineering ,Waste Management and Disposal - Abstract
Microfibrillated cellulose (MFC) was prepared from post-consumer old corrugated container (OCC) material, which was first disintegrated in water, cleaned to remove impurities, and then fibrillated by grinding. Those processed MFCs were treated with in-situ formation of calcium carbonate by adding calcium oxide and injecting carbon dioxide into the mixture up to the ratio of 1:40 (MFC : calcium carbonate) by weight. The MFCs had a dark brown color initially but turned into high brightness materials similar to commercial ground calcium carbonate (GCC) after the in-situ formation process. The MFCs that had calcium carbonate attached on their surfaces, which were lengthy and flexible, were called flexible calcium carbonate from OCC (FCCO). Paper containing FCCO gave higher bulk, higher stiffness, and higher tensile index without lowering smoothness when compared to the paper containing commercial GCC. However, brightness was slightly lowered because of initial low brightness of the OCC. This study also demonstrated the feasibility to substitute wood fibers up to 5% with FCCO without lowering essential properties for printing paper. Benefits of the waste paper are savings of both wood resources and production cost.
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- 2023
39. Study on the Partial Surface Discharge Process of Oil-Paper Insulated Transformer Bushing with Defective Condenser Layer
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Wu, Fan Yang, Yuchen Zhang, Xingwang Wu, and Jie
- Subjects
bushing defect ,oil-paper insulated bushings ,partial discharge ,needle-plane surface discharge - Abstract
Oil-impregnated paper condenser transformer bushings are an important part of transformer equipment, and partial discharge (PD) occurred when defects exist on the condenser aluminum foil layers. Firstly, to study the PD process of the oil-paper insulated capacitance graded bushing with the defect of broken aluminum foil, a defective oil-paper bushing discharge sample is constructed to study the PD parameters and capacitance, and to discharge carbonization traces at different voltage levels. Then, in order to verify the process of condenser aluminum foil layer discharge and the space charge variation in the oil-paper insulation system of a sample model, the surface flashovers of a needle-plane discharge model based on the bipolar charge transport model and the hydrodynamic model was built. The simulation, by Transport of Diluted Species physics of COMSOL Multiphysics software, points out the discharge process of aluminum foil electrode caused by space charge action and electric field distortion under an electric field at different voltages. The results of simulation and sample bushing experiments showed that the PD process of the defective condenser foil layer is mainly divided into three stages: tip corona discharge, streamer in oil, and surface flashovers. The voltage amplitude is larger the more electrical branches are discharged and the shorter the discharge time is. The findings of the article have important implications for the discharge of the foil layer inside the oil-paper bushing.
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- 2023
- Full Text
- View/download PDF
40. Feature Extraction of Oil–Paper Insulation Raman Spectroscopy Based on Manifold Dimension Transformation
- Author
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Zhang, Xingang Chen, Yijie Fan, Zhipeng Ma, Shiyao Tan, Ningyi Li, Xin Song, Yuyang Huang, Jinjing Zhang, and Wenxuan
- Subjects
oil–paper insulation ,Raman spectroscopy ,feature extraction ,state classification - Abstract
Transformers play a crucial role in power systems. In this respect, fault diagnosis and aging state assessment have garnered significant attention from researchers. Herein, accelerated thermal aging and Raman scattering experiments are conducted on oil–paper insulation samples to accurately detect aging states. The samples are categorized into different aging stages based on the polymerization degree of the insulating paper. Principal component analysis (PCA), multi-dimensional scale change method (MDS), and isometric mapping algorithm (Isomap) are employed to extract features from the Raman spectra. Subsequently, the XGBoost strong classifier, optimized through Bayesian hyperparameter optimization (BO-XGBoost), is utilized to distinguish between four and ten states among 175 groups of samples after feature extraction. The subsequent classification results of the three feature-extraction methods are compared. The results indicate that Isoamp, which pertains to the manifold dimension transformation, achieves the highest average discriminative accuracy after feature extraction. The discriminative accuracies for aging states four and ten are 97.0% and 95.1% respectively, demonstrating that Raman spectroscopy manifold dimension transformation enhances the distinctiveness between samples of different aging states in the feature-extraction process. The diagnostic model constructed with Isomap and BO-XGBoost enables accurate discrimination of the aging states of oil–paper insulation.
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- 2023
- Full Text
- View/download PDF
41. Bio-Based Impregnated Resin Preparation for Aldehyde-Free Decorative Paper Production
- Author
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Long, Jin Wang, Jun Liu, and Ling
- Subjects
bio-based materials ,impregnated resin ,aldehyde-free decorative paper - Abstract
With the growing concern for environmental protection and personal health, utilizing bio-based impregnated resin has become a sustainable approach for producing aldehyde-free decorative paper and in-house decorations. Our current work focuses on the preparation of an aldehyde-free resin (AFR) by formulating quaternized cellulose nanofibrils (QCNFs, Ave. width 10 ± 3 nm, Ave. length of and >500 nm) with aqueous acrylate emulsion. We analyzed the synthesized QCNFs, acrylate emulsion, and AFR by using various methods, including FTIR, XPS, XRD, TGA/DTG, and rheometer, to evaluate their applicability for impregnated paper processing. At a low coating weight of 4.0 g/m2, a 30.8% increase and 4.9-times increase in tensile strength and contact angle were detected, respectively. Meanwhile, the free aldehyde emission from the AFR-coated paper was found to be 0.1 mg/L even at a high coating weight of 18.8 g/m2, which is far below the E0 level requirement in the JAS 234:2003 criteria. Therefore, the surface coating of the decorative base paper was found to be competitive in covering the porous structure of the paper, reinforcing its mechanical strength, and providing high water resistance. Moreover, the lower free aldehyde emission from the AFR-coated paper ensures its safety and potential application in house decoration products.
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- 2023
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42. Synergies between Fibrillated Nanocellulose and Hot-Pressing of Papers Obtained from High-Yield Pulp
- Author
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Engstrand, Carlos Negro, Gunilla Pettersson, Amanda Mattsson, Staffan Nyström, Jose Luis Sanchez-Salvador, Angeles Blanco, and Per
- Subjects
hot-pressing technology ,microcellulose ,cellulose nanofibers ,nanocellulose ,high-yield pulp ,CTMP ,paper quality ,packaging - Abstract
To extend the application of cost-effective high-yield pulps in packaging, strength and barrier properties are improved by advanced-strength additives or by hot-pressing. The aim of this study is to assess the synergic effects between the two approaches by using nanocellulose as a bulk additive, and by hot-pressing technology. Due to the synergic effect, dry strength increases by 118% while individual improvements are 31% by nanocellulose and 92% by hot-pressing. This effect is higher for mechanical fibrillated cellulose. After hot-pressing, all papers retain more than 22% of their dry strength. Hot-pressing greatly increases the paper’s ability to withstand compressive forces applied in short periods of time by 84%, with a further 30% increase due to the synergic effect of the fibrillated nanocellulose. Hot-pressing and the fibrillated cellulose greatly decrease air permeability (80% and 68%, respectively) for refining pretreated samples, due to the increased fiber flexibility, which increase up to 90% using the combined effect. The tear index increases with the addition of nanocellulose, but this effect is lost after hot-pressing. In general, fibrillation degree has a small effect which means that low- cost nanocellulose could be used in hot-pressed papers, providing products with a good strength and barrier capacity.
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- 2023
- Full Text
- View/download PDF
43. Measuring Oral Reading Fluency (ORF) Computer-Based and Paper-Based: Examining the Mode Effect in Reading Accuracy and Reading Fluency
- Author
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Gebhardt, Jana Jungjohann, Jeffrey M. DeVries, and Markus
- Subjects
computer-based assessment ,differential item functioning ,oral reading fluency ,mode effects ,paper-based assessment ,progress monitoring - Abstract
Internationally, teachers use oral reading fluency (ORF) measurements to monitor learning progress in reading and adapt instruction to the individual needs of students. In ORF measures, the child reads aloud single syllables, words, or short passages, and the teacher rates in parallel at which items the child makes a mistake. Since administering paper-based ORF requires increased effort on the part of teachers, computer-based test administration is available. However, there are still concerns about the comparability of paper-based and computer-based test modes. In our study, we examine mode effects between paper-based and computer-based test scores for both reading speed and reading accuracy using a German-language ORF assessment for progress monitoring. 2nd- and 3rd-year-students (N = 359) with and without special education needs participated in the study. Results show comparable and high reliability (r > 0.76) and no differential item functioning for both test modes. Furthermore, students showed significantly higher reading speed on the paper-based test, while no differences were found in reading accuracy. In the absence of differential item functioning, we discuss how mean differences can be accounted for, how teachers can be trained to use the different test modes, and how computer-based tests can be safeguarded in practice.
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- 2023
- Full Text
- View/download PDF
44. Effects of Pre-Curing on the Structure and Properties of Paper-Based Materials
- Author
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Zhang, Mingcen Lin, Wenling Zhou, Ye Yao, Jingxiang Chen, and Chunhui
- Subjects
paper-based material ,pre-curing ,phenolic resin ,mechanical properties - Abstract
Paper-based friction material is a typical paper-based composite that is usually cured via hot-pressing. This curing method does not account for the effect of pressure on the matrix resin, resulting in uneven distribution of resin in the material and reducing the mechanical properties of friction materials. To overcome the above shortcomings, a pre-curing method was introduced before hot-pressing, and the effects of different pre-curing degrees on the surface morphology and mechanical properties of paper-based friction materials were studied. The pre-curing degree significantly affected the resin distribution and interfacial bonding strength of the paper-based friction material. When the material was cured at 160 °C for 10 min, the pre-curing degree reached 60%. At this point, most of the resin was in a gel state, which could retain abundant pore structures on the material surface without causing mechanical damage to the fiber and resin matrix during hot-pressing. Ultimately, the paper-based friction material exhibited improved static mechanical properties, decreased permanent deformation, and reasonable dynamic mechanical properties.
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- 2023
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45. Flame-Retardant and Fire-Sensing Packaging Papers Enabled by Diffusion-Driven Self-Assembly of Graphene Oxide and Branched Polyethyleneimine Coatings
- Author
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Ling, Piao Wen, Jing Ren, Qiang Zhang, and Shengjie
- Subjects
paper ,graphene oxide ,self-assembly ,flame retardant ,fire sensor - Abstract
Paper has gained popularity as a packaging material due to its reduced environmental impact compared with non-degradable alternatives. However, its flammability poses safety risks, prompting research on enhancing its flame retardancy. This work introduces a diffusion-driven self-assembly strategy (DDSAS) to create a functional graphene oxide (GO) coating on various packaging papers. DDSAS involves infiltrating the paper’s cellulose microfiber network with branched polyethyleneimine (b-PEI), which binds firmly to cellulose microfibers. Electrostatic interactions between GO and b-PEI then drive GO assembly into a densely stacked, layered structure on the paper surface. This GO structure provides a physical barrier against flames and generates incombustible gases (CO2, H2O, NO2, and NO) when heated, diluting the surrounding oxygen concentration and acting as a heat insulation layer. These factors increase the flame retardancy of treated papers ten-fold. Additionally, the gradual reduction of GO upon heating forms reduced graphene oxide (rGO) on the paper, significantly increasing its electrical conductivity. As a result, the flame-retardant papers not only prevent the fire from spreading but can also act as fire sensors by triggering an alarm signal at the early stages of contact with fire. In summary, this work offers a rational strategy for designing and manufacturing flame-retardant paper packaging materials.
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- 2023
- Full Text
- View/download PDF
46. The Use of a Natural Polysaccharide as a Solidifying Agent and Color-Fixing Agent on Modern Paper and Historical Materials
- Author
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Bellesi, Lucia Emanuele, Tanja Dujaković, Graziella Roselli, Simone Campanelli, and Giulia
- Subjects
opuntia ficus indica ,solidifying agent ,color fixative ,new cleaning method ,bioproducts ,green conservation-restoration ,reversibility ,waste ,paper - Abstract
This article presents results on the use of a new material as a solidifying agent and/or color-fixing agent. A special polysaccharide material extracted from the prickly pear cactus (Opuntia ficus indica) was tested on historical materials and modern papers. An old book from the 18th century was chosen as historical material. From the mentioned book 42 pages were taken, on which a conservation and restoration pretreatment was performed before applying the polysaccharide material: sampling, fiber analysis, dry cleaning, ink solubility, pH test, thickness measurement and wet cleaning. The paper sheets provided for the test were divided into 4 groups, 3 of which were treated with gel and one left untreated as a reference. The division into groups is not only due to the different method of application, but also due to the process of gel extraction. The effect of the treatment was analyzed using FTIR-ATR. To test the mucilage as color-fixing agent 2 samples were prepared using watercolor papers colored with 6 different watercolors applied to 2.5 cm2 samples for each color in two rows of different intensity. One of the 2 samples was treated with gel, but both were immersed for 3 times in a water-ethanol solution for approximately 20 min as is standard practice in conservation and restoration. After washing, both specimens were subjected to colorimetric analysis to assess their differences. The results provided satisfactory evidence for the protection of paints sensitive to aqueous treatments and suggest the use of mucilage as a new material in cleaning method for water-soluble media.
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- 2023
- Full Text
- View/download PDF
47. Correlated Equilibrium and Evolutionary Stability in 3-Player Rock-Paper-Scissors
- Author
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William C. Grant
- Subjects
Statistics and Probability ,correlated equilibrium ,evolutionarily stable strategies ,rock paper scissors ,Applied Mathematics ,Statistics, Probability and Uncertainty - Abstract
In the game of rock-paper-scissors with three players, this paper identifies conditions for a correlated equilibrium that differs from the mixed strategy Nash equilibrium and is evolutionarily stable. For this to occur, the correlation device attaches more probability to three-way ties and solo-winner outcomes than would result from the Nash equilibrium. The correlated equilibrium is evolutionarily stable because any mutant fares worse than a signal-following player when facing two players who follow their own correlated signals. The critical quality of the correlation device is to make this true both for potential mutants who would disobey their signal and instead choose the action which would beat the action signaled to the player, as well as for potential mutants who would deviate to the action that would be beaten by what the device signals to the player. These findings reveal how a strict correlated equilibrium can produce evolutionarily stable strategies for rock-paper-scissors with three players.
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- 2023
- Full Text
- View/download PDF
48. Lignin-Degrading Bacteria in Paper Mill Sludge
- Author
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Magda Rodriguez-Yupanqui, Magaly De La Cruz-Noriega, Claudio Quiñones, Nélida Milly Otiniano, Medardo A. Quezada-Alvarez, Walter Rojas-Villacorta, Gino A. Vergara-Medina, Frank R. León-Vargas, Haniel Solís-Muñoz, and Segundo Rojas-Flores
- Subjects
Microbiology (medical) ,Virology ,paper mill sludge ,black liquor ,laccase activity ,Agrobacterium tumefasciens ,Klebsiella grimontii ,Beijeinckia fluminensis ,Microbiology - Abstract
The effluents generated in the paper industry, such as black liquor, have a high content of lignin and other toxic components; however, they represent a source of lignin-degrading bacteria with biotechnological potential. Therefore, the present study aimed to isolate and identify lignin-degrading bacteria species in paper mill sludge. A primary isolation was carried out from samples of sludge present in environments around a paper company located in the province of Ascope (Peru). Bacteria selection was made by the degradation of Lignin Kraft as the only carbon source in a solid medium. Finally, the laccase activity (Um-L−1) of each selected bacteria was determined by oxidation of 2,2′-azinobis-(3-etilbencenotiazolina-6-sulfonate) (ABTS). Bacterial species with laccase activity were identified by molecular biology techniques. Seven species of bacteria with laccase activity and the ability to degrade lignin were identified. The bacteria Agrobacterium tumefasciens (2), Klebsiella grimontii (1), and Beijeinckia fluminensis (1) were reported for first time. K. grimowntii and B. fluminensis presented the highest laccase activity, with values of 0.319 ± 0.005 UmL−1 and 0.329 ± 0.004 UmL−1, respectively. In conclusion, paper mill sludge may represent a source of lignin-degrading bacteria with laccase activity, and they could have potential biotechnological applications.
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- 2023
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49. Antioxidant Protection of Paper Heritage Objects with 4-Amino-2,2,6,6-Tetramethylpiperidine
- Author
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Katarína Vizárová, Soňa Malečková, Radko Tiňo, Milena Reháková, and František Kačík
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acid paper ,stabilization ,piperidine ,magnesium ,hexamethyldisiloxane ,General Materials Science - Abstract
In protecting cultural heritage, deacidification is used to stabilize acidic papers, ensuring the neutralization of acids present in the paper. But in the process of aging, several mechanisms of degradation occur simultaneously. Therefore, substances used to stabilize the paper should contain an antioxidant component in addition to the deacidifying component. The effect of the antioxidant (hindered amine light stabilizers—HALS type) on the stabilization of lignin-containing acid papers during accelerated aging was studied in this work. The effective deacidification component was magnesium; the solvent was hexamethyldisiloxane (HMDSO). The 4-amino-2,2,6,6-tetramethylpiperidine series of hindered amine light stabilizers (HALS) was selected as appropriate for creating a modifying system based on HMDSO. The modification system was tested on samples of a model test acid lignin-containing paper (NOVO) and naturally aged acidic paper from the real book. The addition of substances to the proposed deacidification system has a favorable effect on stabilizing the pH during aging and provides the inhibition of the oxidative degradation products and stabilization of the cellulose degree of polymerization. It was confirmed that the application of the system containing deacidification and an antioxidant component may increase the effectiveness of the protection of acid groundwood paper heritage objects. Adding a tested antioxidant to the proposed deacidification system has a favorable effect on stabilizing the pH value for a long time in accelerated aging.
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- 2023
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50. Super-Stable Metal–Organic Framework (MOF)/Luciferase Paper-Sensing Platform for Rapid ATP Detection
- Author
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Héctor Martínez-Pérez-Cejuela, Maria Maddalena Calabretta, Valerio Bocci, Marcello D’Elia, and Elisa Michelini
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Clinical Biochemistry ,Biomedical Engineering ,General Medicine ,Instrumentation ,Engineering (miscellaneous) ,ATP ,luciferase ,biosensor ,metal–organic frameworks ,bioluminescence ,paper-sensing ,Analytical Chemistry ,Biotechnology - Abstract
Adenosine triphosphate (ATP) determination has been used for many decades to assess microbial contamination for hygiene monitoring in different locations and workplace environments. Highly sophisticated methods have been reported, yet commercially available kits rely on a luciferase–luciferin system and require storage and shipping at controlled temperatures (+4 or −20 °C). The applicability of these systems is limited by the need for a secure cold chain, which is not always applicable, especially in remote areas or low-resource settings. In this scenario, easy-to-handle and portable sensors would be highly valuable. Prompted by this need, we developed a bioluminescence paper biosensor for ATP monitoring in which a new luciferase mutant was combined with a metal–organic framework (MOF); i.e., zeolitic imidazolate framework-8 (ZIF-8). A paper biosensor was developed, ZIF-8@Luc paper sensor, and interfaced with different portable light detectors, including a silicon photomultiplier (SiPM) and smartphones. The use of ZIF-8 not only provided a five-fold increase in the bioluminescence signal, but also significantly improved the stability of the sensor, both at +4 and +28 °C. The ATP content in complex biological matrices was analyzed with the ZIF-8@Luc paper sensor, enabling detection down to 7 × 10−12 moles of ATP and 8 × 10−13 moles in bacterial lysates and urine samples, respectively. The ZIF-8@Luc sensor could, therefore, be applied in many fields in which ATP monitoring is required such as the control of microbial contamination.
- Published
- 2023
- Full Text
- View/download PDF
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