scholarly journals Precision Auto-Focusing Apparatus Based on Long-Working-Distance, Wide-Spectrum Microscope

2020 ◽  
Vol 10 (13) ◽  
pp. 4621
Author(s):  
Chao Wang ◽  
Tao Zhang ◽  
Weibo Wang

A mirror-based Schwarzschild microscope with a wide spectrum and a long working distance was investigated to perform precise assemblage of detectors. We employed a gradient square method to construct the evaluation function for realizing accurate quantitative analysis of image defocusing. By imaging a resolution target that corresponded to 228 line pairs per mm, the validity and imaging ability of the system was proven. The results of repeated focusing tests yielded a standard deviation of 0.75 μm, which indicated high performance accuracy for the focusing system. The proposed system has potential applications in industrial inspection and focusing detection.

Author(s):  
Auclair Gilles ◽  
Benoit Danièle

During these last 10 years, high performance correction procedures have been developed for classical EPMA, and it is nowadays possible to obtain accurate quantitative analysis even for soft X-ray radiations. It is also possible to perform EPMA by adapting this accurate quantitative procedures to unusual applications such as the measurement of the segregation on wide areas in as-cast and sheet steel products.The main objection for analysis of segregation in steel by means of a line-scan mode is that it requires a very heavy sampling plan to make sure that the most significant points are analyzed. Moreover only local chemical information is obtained whereas mechanical properties are also dependant on the volume fraction and the spatial distribution of highly segregated zones. For these reasons we have chosen to systematically acquire X-ray calibrated mappings which give pictures similar to optical micrographs. Although mapping requires lengthy acquisition time there is a corresponding increase in the information given by image anlysis.


2020 ◽  
Vol 16 (4) ◽  
pp. 462-477 ◽  
Author(s):  
Patrizia Bocchetta ◽  
Domenico Frattini ◽  
Miriana Tagliente ◽  
Filippo Selleri

By collecting and analyzing relevant literature results, we demonstrate that the nanostructuring of polypyrrole (PPy) electrodes is a crucial strategy to achieve high performance and stability in energy devices such as fuel cells, lithium batteries and supercapacitors. In this critic and comprehensive review, we focus the attention on the electrochemical methods for deposition of PPy, nanostructures and potential applications, by analyzing the effect of different physico-chemical parameters, electro-oxidative conditions including template-based or template-free depositions and cathodic polymerization. Diverse interfaces and morphologies of polymer nanodeposits are also discussed.


2013 ◽  
Vol 721 ◽  
pp. 497-500
Author(s):  
Guo Jin Chen ◽  
Jing Ni ◽  
Ting Ting Liu ◽  
Ming Xu

Aiming at the lower performance, accuracy and efficiency of the existing motion control process for the traditional broaching machine, the paper studies the high-performance dual-hydraulic synchronous servo drive control technology. The synchronous electro-hydraulic servo system forms the closed loop control by the detection and feedback of the output quantity. It eliminates and restrains largely the influence of the adverse factors to obtain the high-precision synchronous driving performance. The numerical control system based on the real-time error compensation and the intelligent control to the auxiliary machinery is developed. It is used for the CNC broaching machine to make the steady-state synchronous displacement error of the double cylinders be ≤ 0.5mm.


Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 197
Author(s):  
Giorgia Giovannini ◽  
René M. Rossi ◽  
Luciano F. Boesel

The development of hybrid materials with unique optical properties has been a challenge for the creation of high-performance composites. The improved photophysical and photochemical properties observed when fluorophores interact with clay minerals, as well as the accessibility and easy handling of such natural materials, make these nanocomposites attractive for designing novel optical hybrid materials. Here, we present a method of promoting this interaction by conjugating dyes with chitosan. The fluorescent properties of conjugated dye–montmorillonite (MMT) hybrids were similar to those of free dye–MMT hybrids. Moreover, we analyzed the relationship between the changes in optical properties of the dye interacting with clay and its structure and defined the physical and chemical mechanisms that take place upon dye–MMT interactions leading to the optical changes. Conjugation to chitosan additionally ensures stable adsorption on clay nanoplatelets due to the strong electrostatic interaction between chitosan and clay. This work thus provides a method to facilitate the design of solid-state hybrid nanomaterials relevant for potential applications in bioimaging, sensing and optical purposes.


2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Paula Karina S. Uchoa ◽  
Leandro Bezerra de Lima ◽  
Antonia T. A. Pimenta ◽  
Maria da Conceição F. de Oliveira ◽  
Jair Mafezoli ◽  
...  

A high-performance liquid chromatography method was developed and validated for the quantification of the cytotoxic compounds produced by a marine strain ofAspergillus niger. The fungus was grown in malt peptone dextrose (MPD), potato dextrose yeast (PDY), and mannitol peptone yeast (MnPY) media during 7, 14, 21, and 28 days, and the natural products were identified by standard compounds. The validation parameters obtained were selectivity, linearity (coefficient of correlation > 0.99), precision (relative standard deviation below 5%), and accuracy (recovery > 96).


2012 ◽  
Vol 468-471 ◽  
pp. 534-537
Author(s):  
Zhao Hua Lin ◽  
Xin Liu ◽  
Yu Liang Zhang ◽  
Shu Mei Zhang

A coarse and fine combined fast search and auto-focusing algorithm was suggested in this paper. This method can automatically search and find the focal plane by evaluating the image definition. The Krisch operator based edge energy function was used as the big-step coarse focusing, and then the wavelet transform based image definition evaluation function, which is sensitivity to the variation in image definition, was used to realize the small-step fine focusing in a narrow range. The un-uniform sampling function of the focusing area selection used in this method greatly reduces the workload and the required time for the data processing. The experimental results indicate that this algorithm can satisfy the requirement of the optical measure equipment for the image focusing.


2021 ◽  
Author(s):  
Sara Reichenbach ◽  
Benjamin Kromoser ◽  
Philipp Preinstorfer ◽  
Tobias Huber

<p>With the building industry being one of the main sources of carbon dioxide emission worldwide and concrete being the main construction material, new strategies have to be developed to reduce the carbon footprint thereof. The use of high-performance materials in structural concrete, as for example textile-reinforced concrete (TRC), seems to allow for a reduction of the resource consumption and the carbon emissions. The present paper addresses potential applications of TRC examining the global warming potential (GWP) of a rail platform barrier. The resource consumption is depicted in a parametrical study in terms of the necessary component height and reinforcement area considering both the serviceability limit state (SLS) as well as the ultimate limit state (ULS). The results clearly indicate an achievable reduction of the GWP during construction when using textile reinforcement made of high-performance fibres. Furthermore, an analysis of the European market was conducted to prove the availability of this new reinforcement type. </p>


2013 ◽  
Vol 448-453 ◽  
pp. 406-408
Author(s):  
Jing Liu ◽  
Xiao Na Ji ◽  
Qing Kai Ren ◽  
Sheng Shu Ai ◽  
Li Jun Wan ◽  
...  

We established a method fordetermination of nitrate in water by High Performance Liquid Chromatography(HPLC). The sample was analysed by HPLC-ADA and was quantitated by externalstandard method after being simply processed. This methd has the advantages ofhigh separation efficiency and fast analysis. The experiment result showed thatthe linearly dependent coefficient was0.994, the recovery rate was between 98.7%~105.7%,the relative standard deviation(RSD)wasless than 2.1 %, and the lowest detectable limit is 0.01ng (S/N=1.6).


1994 ◽  
Vol 15 (2) ◽  
pp. 1-8 ◽  
Author(s):  
Choo Yuen May

Crude palm oil is the richest natural plant source of carotenoids in terms of retinol (provitamin A) equivalent. This article reports on » the carotenoids found in palm oil, its fractions, byproducts, and derivatives from the Elaeis guineensis and E. oleifera palms, including their hybrids and a back-cross, as well as the carotenoids of pressed palm fibres, second-pressed oil, palm leaves, and palm-derived alkyl esters; » two novel procedures for preparing highly concentrated sources of carotenoids (>80,000 ppm), by recovery by palm alkyl esters, and by retention and concentration in deacidified and deodorized red palm oil; » the carotenoid content and profiles of the above sources obtained by high-performance liquid chromatography; and » nutritional effects of palm oil carotenoids and their potential applications for health promotion and disease prevention.


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