Development of a Multi-Step Exposure Method for Projection-Based Printing System

Author(s):  
Dai Xue ◽  
Yancheng Wang ◽  
Deqing Mei ◽  
Yue Wang

Projection-based printing has been proven to be an effective way to fabricate user defined complex structures in biomedical applications. Large-scale printing of this process remains a challenge due to the lack of light source with large irradiation area and long transmitting distances. This paper presents a novel method by using multi-step exposure for large-scale parts printing in projection-based printing system. The multi-step exposure method takes the advantage of using a serial of digital masks for exposure incrementally, thus can compensate the printing differences induced by unevenly distributed ultraviolet (UV) intensity. The system setup and printing characterization of the projection-based printing system are studied. The distribution of the UV light power density is measured and the relationship between the printed height and printing parameters are investigated. Then, a multi-step exposure method is proposed and followed by experimental validation. Results showed that the developed printing system with five-step exposure can be used for a relatively large-scale parts printing, and a relatively flat profile can be achieved. Thus, this method provides the potential ability to print large-scale objects for biomedical applications.

Morphology ◽  
2021 ◽  
Author(s):  
Rossella Varvara ◽  
Gabriella Lapesa ◽  
Sebastian Padó

AbstractWe present the results of a large-scale corpus-based comparison of two German event nominalization patterns: deverbal nouns in -ung (e.g., die Evaluierung, ‘the evaluation’) and nominal infinitives (e.g., das Evaluieren, ‘the evaluating’). Among the many available event nominalization patterns for German, we selected these two because they are both highly productive and challenging from the semantic point of view. Both patterns are known to keep a tight relation with the event denoted by the base verb, but with different nuances. Our study targets a better understanding of the differences in their semantic import.The key notion of our comparison is that of semantic transparency, and we propose a usage-based characterization of the relationship between derived nominals and their bases. Using methods from distributional semantics, we bring to bear two concrete measures of transparency which highlight different nuances: the first one, cosine, detects nominalizations which are semantically similar to their bases; the second one, distributional inclusion, detects nominalizations which are used in a subset of the contexts of the base verb. We find that only the inclusion measure helps in characterizing the difference between the two types of nominalizations, in relation with the traditionally considered variable of relative frequency (Hay, 2001). Finally, the distributional analysis allows us to frame our comparison in the broader coordinates of the inflection vs. derivation cline.


2021 ◽  
Vol 903 ◽  
pp. 11-16
Author(s):  
M.A. Manjunath ◽  
K. Naveen ◽  
Prakash Vinod ◽  
N. Balashanmugam ◽  
M.R. Shankar

Polymethyl methacrylate (PMMA) is one among few known photo-polymeric resin useful in lithography for fabricating structures having better mechanical properties to meet the requirement in electronics and biomedical applications. This study explores the effect of Photo Initiator (PI) concentration and also curing time on strength and hardness of Polymethyl methacrylate (PMMA) obtained by UV photopolymerization of Methyl methacrylate (MMA) monomer. The UV LED light source operating at the wavelength of 364 nm is used with Benzoin Ethyl Ether (BEE) as photo initiator. The curing of PMMA resin is supported with peltier cooling device placed at the bottom of the UV light source. The characterisation study of UV photo cured PMMA is analysed through nano indenter (Agilent Technologies-G200). The current work investigates the influence of PI concentration and curing time in achieving maximum mechanical properties for UV photopolymerized PMMA.


2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Jun Long ◽  
Lei Zhu ◽  
Zhan Yang ◽  
Chengyuan Zhang ◽  
Xinpan Yuan

Vast amount of multimedia data contains massive and multifarious social information which is used to construct large-scale social networks. In a complex social network, a character should be ideally denoted by one and only one vertex. However, it is pervasive that a character is denoted by two or more vertices with different names; thus it is usually considered as multiple, different characters. This problem causes incorrectness of results in network analysis and mining. The factual challenge is that character uniqueness is hard to correctly confirm due to lots of complicated factors, for example, name changing and anonymization, leading to character duplication. Early, limited research has shown that previous methods depended overly upon supplementary attribute information from databases. In this paper, we propose a novel method to merge the character vertices which refer to the same entity but are denoted with different names. With this method, we firstly build the relationship network among characters based on records of social activities participating, which are extracted from multimedia sources. Then we define temporal activity paths (TAPs) for each character over time. After that, we measure similarity of the TAPs for any two characters. If the similarity is high enough, the two vertices should be considered as the same character. Based on TAPs, we can determine whether to merge the two character vertices. Our experiments showed that this solution can accurately confirm character uniqueness in large-scale social network.


2018 ◽  
Author(s):  
Ming Li ◽  
Bingbing Dai ◽  
Yawei Tang ◽  
Lei Lei ◽  
Ningning Li ◽  
...  

ABSTRACTIntestinal bacterial dysbiosis has been increasingly linked to Ankylosing Spondylitis (AS), which is a prototypic and best studied subtype of Spondyloarthritis (SpA). Fungi and bacteria coexist in human gut and interact with each other, although they have been shown to contribute actively to health or diseases, no studies have investigated whether fungal microbiota in AS patients is perturbed. In this study, fecal samples of 22 AS patients, with clinical and radiographic assessments, and 16 healthy controls (HCs) were collected to systematically characterize the gut microbiota and mycobiota in AS patients by 16S rDNA and ITS2-based DNA sequencing. The relationships between therapeutic regimens, disease activity, radiographic damage of AS and gut micro/mycobiome were investigated. Our results showed a distinct mycobiota pattern in AS in addition to microbiota dysbiosis. The gut mycobiome of AS patients was characterized by higher taxonomic levels of Ascomycota, especially the class of Dothideomycetes, and decreased abundance of Basidiomycota, which was mainly contributed by the decease of Agaricales. Compared to HCs, changing of the ITS2/16S biodiversity ratio, and bacteria-fungi interkingdom network were observed in AS patients. Alteration of gut mycobiota was associated with different therapeutic regimens, disease activity, as well as different degrees of radiographic damage. Moreover, we unraveled a disease-specific interkingdom network alteration in AS. Finally, we also identified some trends suggesting that different therapeutic regimens may induce changing of both bacterial and fungal microbiota in AS.IMPORTANCEHuman gut is colonized by diverse fungi (mycobiome), and they have long been suspected in the pathogenesis of Spondyloarthritis (SpA). Our study unraveled a disease-specific interkingdom network alteration in AS, suggesting that fungi, or the interkingdom interactions between bacteria and fungi, may play an essential role in AS development. However, limited by sample size and indeep mechanism studies, further large scale investigations on the characterization of gut mycobiome in AS patients are needed to form a foundation for research into the relationship between mycobiota dysbiosis and AS development.


2019 ◽  
Vol 7 (1) ◽  
pp. 63-79 ◽  
Author(s):  
Seiya Okubo ◽  
Yuta Kado ◽  
Yamato Takeuchi ◽  
Mitsuo Wakatsuki ◽  
Tetsuro Nishino

The purpose of this article is to clarify the fundamentals of the card game Daihinmin. By collecting logs of Daihinmin games on a large scale and analyzing them, the authors illuminate the game's characteristics. They discuss the content required from the game to this end and examine the types of logs that must be collected. They then report on the collection of various logs and the calculation of certain features to characterize Daihinmin. Furthermore, the authors investigate the relationship between the initial hands and rankings of players, as well as the influence of the exchange rule, through a computer experiment.


2011 ◽  
Vol 110-116 ◽  
pp. 3838-3843
Author(s):  
Tron Min Chen ◽  
Kai Ming Uang ◽  
Hao Xiang Chen ◽  
Shu Kuo Lin

In this study, we report the fabrication and characterization of a novel nanohetero junction structure (NHJ) UV photodetectors (PDs) on flexible polyethylene terephthalate (PET). The ZnO nanowires (NWs) were grown by 2-step hydrothermal growth (HTG) onto p-type nickel oxide (p-NiO) film deposited PET flexible substrate. For enhancing the quality and reliability of the fabricated UV PDs, the PET substrate was treated with a beforehand thermosetting process to refine its toughness and flatness. By switching the illumination UV light “on” and “off”, the fabricated UV PDs biased under-5 V have an on-off current ratio of 16. After over 100 times 90obend, the transient measurement almost has the same reversibility but on-off current ratio reducing to 10. These results suggest that the proposed n-ZnO-NWs/p-NiO NHJs on PET flexible PET substrate not only have a fairly good response to UV light but also have good endurance within suitable bend. The present optoelectronic UV sensor would provide an effective and simple way for future developments of flexible optoelectronic devices.


Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 383
Author(s):  
C. Fernández-Ponce ◽  
J. M. Mánuel ◽  
R. Fernández-Cisnal ◽  
E. Félix ◽  
J. Beato-López ◽  
...  

An optimal design of nanoparticles suitable for biomedical applications requires proper functionalization, a key step in the synthesis of such nanoparticles, not only for subsequent crosslinking to biological targets and to avoid cytotoxicity, but also to endow these materials with colloidal stability. In this sense, a reliable characterization of the effectiveness of the functionalization process would, therefore, be crucial for subsequent bioconjugations. In this work, we have analyzed glutathione as a means to functionalize four of the most widely used nanoparticles in biomedicine, one of which is a hybrid gold-magnetic-iron-oxide nanoparticle synthetized by a simple and novel method that we propose in this article. We have analyzed the colloidal characteristics that the glutathione capping provides to the different nanoparticles and, using information on the Z-potential, we have deduced the chemical group used by glutathione to link to the nanoparticle core. We have used electron microscopy for further structural and chemical characterization of the nanoparticles. Finally, we have evaluated nanoparticle cytotoxicity, studying cell viability after incubation with different concentrations of nanoparticles, showing their suitability for biomedical applications.


Author(s):  
Steven J Schrodi

Recent analytic and technological breakthroughs have set the stage for genome-wide linkage disequilibrium studies to map disease-susceptibility variants. This paper discusses a probabilistic methodology for making disease-mapping inferences in large-scale case-control genetic studies. The semi-Bayesian approach promoted compares the probability of the observed data under disease hypotheses to the probability of the data under a null hypothesis defined by data at all the markers interrogated in a large study. This method automatically adjusts for the effects of diffuse population stratification. It is claimed that this characterization of the evidence for or against disease models may facilitate more appropriate inductions for large-scale genetic studies. Results include (i) an analytic solution for the population stratification-adjusted Bayes’ factor, (ii) the relationship between sample size and Bayes’ factors, (iii) an extension to an approximate Bayes’ factor calculated across closely-linked sites, and (iv) an extension across multiple studies. Although this paper deals exclusively with genetic studies, it is possible to generalize the approach to treat many different large-scale experiments including studies of gene expression and proteomics.


2020 ◽  
Vol 62 ◽  
pp. 75-86 ◽  
Author(s):  
Alexandros Barnasas ◽  
Michalis V. Karavasilis ◽  
Christos Aggelopoulos ◽  
Christos D. Tsakiroglou ◽  
Panagiotis Poulopoulos

In this work, a low-cost method to produce ZnO nanostructured materials for the treatment of water polluted with model organic pollutants (e.g. dyes) is presented. Zinc and silver-coated Zn (Ag/Zn) films, fabricated via sputtering method were naturally oxidized via a simple, low-temperature, scalable thermal process. During oxidation, Ag/ZnO nanorods were grown on Zn foils after treating their surface with various agents (e.g. acids) and annealing in an oven at temperatures 385-400 °C. The ZnO and Ag/ZnO films on Zn were characterized by X-ray diffraction, scanning electron microscopy and photoluminescence spectroscopy. The cationic dye Methylene Blue (MB) was selected as model pollutant dissolved in water, and a batch photo-reactor was fabricated and used to to study the adsorption capacity and photocatalytic performance of films. The transient varation of MB concentration in aqueous solutions was measured with UV-Vis spectroscopy. Ag/ZnO demonstrated a strong MB adsorbion capacity in dark conditions, and a satisfactory MB photocatalytic degradation under UV light irradiation.The optimized doping of Ag in Ag/ZnO film enhanced its photocatalytic activity, and seems well-promising for the potential scale-up of Ag/ZnO films, and use in large-scale systems for water purification under UV light irradiation.


2017 ◽  
Vol 95 (9) ◽  
pp. 954-964 ◽  
Author(s):  
Mario Ficker ◽  
Valentina Paolucci ◽  
Jørn B. Christensen

Dendrimers are promising polymers for biomedical applications; however, most dendrimer formulations have failed to move from laboratory science to upscaled products for preclinical testing or GMP production. This publications reports on an improved large-scale PAMAM dendrimer synthesis that is suitable to manufacture large amounts of highly pure and monodisperse dendrimers of generations G0–G5. Furthermore, an extended analytical guideline how to characterize PAMAM dendrimers with NMR, HPLC, SEC-MALS, ESI, MALDI, UV–vis, fluorescence, and IR spectroscopy is provided.


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