Basic Study on Polishing Technology for Microcavity With Electrically Controlled Slurry

2020 ◽  
Author(s):  
Yuka Hayama ◽  
Yasuhiro Kakinuma
Keyword(s):  
High Performance ◽  
Optical Signal ◽  
Basic Study ◽  
Suitable Material ◽  
Frequency Combs ◽  
Optical Microcavity ◽  
Precision Turning ◽  
Short Period ◽  
Wide Range ◽  
Ultra Precision

Abstract Optical microcavity, which can localize light at a certain spot for a short period of time, have a wide range of applications, such as optical signal processing and optical frequency combs. Single crystal calcium fluoride is one of the most suitable material for fabricating optical microcavity due to its excellent optical properties; however, it cannot be manufactured by chemical processes such as etching due to its crystal anisotropy. Currently, high performance optical microcavities are fabricated by ultra-precision turning followed by a hand polishing process because it has complex shape with a size of micro order. However, hand polishing deteriorates the shape made by ultra-precision turning and has a low reproductivity. Therefore, a development of a soft mechanical polishing method to replace hand polishing is strongly desired. Electrically controlled slurry technique is a promising approach in polishing of microparts, where AC electric field is applied to the slurry in order to control the distribution of abrasives to improve the polishing properties in free abrasive polishing. In this study, polishing by applying electrically controlled slurry was conducted for microcavity and the influence of frequency and applied voltage were investigated. From the experimental results, clear differences in the surface quality of microcavity were shown according to amplitude of AC voltage and its frequency.

RkRk material measure

2019 ◽  
Vol 86 (9) ◽  
pp. 478-486 ◽  
Author(s):  
Jörg Seewig ◽  
Matthias Eifler ◽  
Dorothee Hüser ◽  
Rudolf Meeß
Keyword(s):  
Surface Profile ◽  
Profile Data ◽  
Measuring Process ◽  
Suitable Material ◽  
Precision Turning ◽  
Functional Characterisation ◽  
Ultra Precision ◽  
Measured Profile ◽  
Material Measure ◽  
Comparison Measurements

AbstractThe standard ISO 13565-2 defines the Rk parameters for the functional characterisation of technical surfaces. So far, no particular material measures for the calibration of these parameters have been defined in the international standardization. For the application and the functional behaviour of technical surfaces the Rk parameters however have a critical significance, so there is a demand by the industry to calibrate these parameters as they are increasingly applied for the quality assessment of workpieces. In the present paper, a proposal for suitable material measures is presented. An algorithm is described, which transforms the data of a real measured profile in a way that the exact defined parameters of Rk, Rpk and Rvk are equated. The material measures geometry corresponds to its later application and the target parameters are almost freely selectable. The approach for transforming surface profile data with the aid of the Abbott curve is introduced generically, solves an inverse problem and considers the influences from the manufacturing and measuring process. The designed material measure is manufactured with the aid of ultra-precision turning. In matters of the aspired industrial application, comparison measurements are carried out in order to examine the practical abilities of the material measure and the repeatability of the approach is proven.

scholarly journals Acid Phosphatases from the Bread Fruit Artocarpus communis Seeds as Novel Plant Phosphorylating Biocatalysts

2019 ◽  
pp. 1-8
Author(s):  
Hubert Kouassi Konan ◽  
Michel Djary Koffi ◽  
Desire Yapi Assoi Yapi ◽  
Lucien Patrice Kouame
Keyword(s):  
High Performance ◽  
Time Course ◽  
Food Additives ◽  
Product Yield ◽  
Industrial Applications ◽  
Synthesis Product ◽  
Acid Phosphatases ◽  
Short Period ◽  
Donor And Acceptor ◽  
Wide Range

Aims: Investigation on the phosphotransferase activity of two non-specific acid phosphatases (EC 3.1.3.2) designated as AP1 and AP2, previously isolated from breadfruit (Artocarpus communis) seeds for further biotechnological and industrial applications. Methodology: Transphosphorylation reactions were tested with sodium pyrophosphate as the phosphoryl donor and phenol as its acceptor. Transfer products were quantified by using high performance liquid chromatography. Results: The two acid phosphatases were able to catalyse phosphoconjugates synthesis using pyrophosphate as the phosphoryl donor and phenol as acceptor. The optimal conditions of transphosphorylation reactions indicated that this synthesis was highly dependent on pH, temperature, time course, donor and acceptor concentrations and enzyme amount. A very short period (1.25 h) was observed for these synthesis reactions catalysed by acid phosphatases isolated from breadfruit (Artocarpus communis) seeds. This suggested energy saving during biotransformation processes. The high average yields of 84.20 and 66.78% obtained for AP1 and AP2, respectively, made them useful to phosphorylate a wide range of nucleophile compounds such as nucleotides often used as food additives and pharmaceutical intermediates. Conclusion: The acid phosphatase AP1 would be the most promising on the basis the better synthesis product yield (84.20%). The two biocatalysts could be considered as new valuable tools for bioprocesses.

Acid phosphatases from the breadfruit Artocarpus communis seeds as novel plant phosphorylating biocatalysts

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Hubert Kouassi Konan ◽  
Michel Djary Koffi ◽  
Desire Yapi Assoi Yapi ◽  
Lucien Patrice Kouame
Keyword(s):  
High Performance ◽  
Time Course ◽  
Food Additives ◽  
Product Yield ◽  
Industrial Applications ◽  
Synthesis Product ◽  
Acid Phosphatases ◽  
Short Period ◽  
Donor And Acceptor ◽  
Wide Range

Abstract Objective Investigation on the phosphotransferase activity of two non-specific acid phosphatases (EC 3.1.3.2) designated as AP1 and AP2, previously isolated from breadfruit (Artocarpus communis) seeds for further biotechnological and industrial applications. Methods Transphosphorylation reactions were tested with sodium pyrophosphate as the phosphoryl donor and phenol as its acceptor. Transfer products were quantified by using high performance liquid chromatography. Results The two acid phosphatases were able to catalyze phosphoconjugates synthesis using pyrophosphate as the phosphoryl donor and phenol as acceptor. The optimal conditions of transphosphorylation reactions indicated that this synthesis was highly dependent on pH, temperature, time course, donor and acceptor concentrations and enzyme amount. A very short period (1.25 h) was observed for these synthesis reactions catalyzed by acid phosphatases isolated from breadfruit (Artocarpus communis) seeds. This suggested energy saving during biotransformation processes. The high average yields of 84.20 and 66.78% obtained for AP1 and AP2, respectively, made them useful to phosphorylate a wide range of nucleophile compounds such as nucleotides often used as food additives and pharmaceutical intermediates. Conclusion The acid phosphatase AP1 would be the most promising on the basis the better synthesis product yield (84.20%). The two biocatalysts could be considered as new valuable tools for bioprocesses.

High performance ultra-precision turning of large-aspect-ratio rectangular freeform optics

CIRP Annals ◽  
2018 ◽  
Vol 67 (1) ◽  
pp. 543-546 ◽  
Author(s):  
Xiaodong Zhang ◽  
Zexiao Li ◽  
Guoxiong Zhang
Keyword(s):  
Aspect Ratio ◽  
High Performance ◽  
Large Aspect Ratio ◽  
Precision Turning ◽  
Freeform Optics ◽  
Ultra Precision

scholarly journals End-to-End Automated Guided Modular Vehicle

2020 ◽  
Vol 10 (12) ◽  
pp. 4400 ◽  
Author(s):  
Luis A. Curiel-Ramirez ◽  
Ricardo A. Ramirez-Mendoza ◽  
Rolando Bautista-Montesano ◽  
M. Rogelio Bustamante-Bello ◽  
Hugo G. Gonzalez-Hernandez ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Autonomous Vehicles ◽  
Autonomous Navigation ◽  
High Performance ◽  
Low Cost ◽  
Open Architecture ◽  
Short Period ◽  
Wide Range ◽  
The Subject ◽  
Computing Capacity

Autonomous Vehicles (AVs) have caught people’s attention in recent years, not only from an academic or developmental viewpoint but also because of the wide range of applications that these vehicles may entail, such as intelligent mobility and logistics, as well as for industrial purposes, among others. The open literature contains a variety of works related to the subject. They employ a diversity of techniques ranging from probabilistic to ones based on Artificial Intelligence. The increase in computing capacity, well known to many, has opened plentiful opportunities for the algorithmic processing needed by these applications, making way for the development of autonomous navigation, in many cases with astounding results. The following paper presents a low-cost but high-performance minimal sensor open architecture implemented in a modular vehicle. It was developed in a short period of time, surpassing many of the currently available solutions found in the literature. Diverse experiments were carried out in the controlled and circumscribed environment of an autonomous circuit that demonstrates the efficiency of the applicability of the developed solution.

scholarly journals All-fibre heterogeneously-integrated frequency comb generation using silicon core fibre

2021 ◽  
Author(s):  
Ronit Sohanpal ◽  
Haonan Ren ◽  
Li Shen ◽  
Callum Deakin ◽  
Alexander Heidt ◽  
...  
Keyword(s):  
Signal Processing ◽  
High Power ◽  
High Performance ◽  
Frequency Comb ◽  
Signal To Noise Ratio ◽  
Optical Signal ◽  
Frequency Combs ◽  
Core Fibre ◽  
Comb Generation ◽  
Technical Features

Abstract Originally developed for metrology, optical frequency combs are becoming increasingly pervasive in a wider range of research topics including optical communications, spectroscopy, and radio or microwave signal processing. However, application demands in these fields can be more challenging as they require compact sources with a high tolerance to temperature variations that are capable of delivering flat comb spectra, high power per tone, narrow linewidth and high optical signal-to-noise ratio (OSNR). To date, there has not been a frequency comb technology that is able to simultaneously achieve all these requirements. This work reports the generation of a flat, high power frequency comb in the telecom band using a 17-mm fully-integrated silicon core fibre (SCF) as a parametric mixer. Our all-fibre, cavity-free source combines the materials benefits of planar waveguide structures with the advantageous properties of fibre platforms to achieve a 30 nm bandwidth comb source containing 143 tones with <3 kHz linewidth, 12 dB flatness, and >30 dB OSNR over the entire spectral region. The unique combination of technical features offered by this SCF-based source opens a path towards a new class of high-performance frequency comb generators for communications and signal processing applications.

Validated Stability Indicating HPTLC Method for the Estimation of Amoxapine in Different Stress Conditions

2019 ◽  
Vol 15 (3) ◽  
pp. 273-279
Author(s):  
Shweta G. Rangari ◽  
Nishikant A. Raut ◽  
Pradip W. Dhore
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Degradation Products ◽  
Analysis Data ◽  
Peak Height ◽  
Good Resolution ◽  
Stability Indicating ◽  
Limit Of Quantitation ◽  
Wide Range ◽  
Hptlc Method

Background:The unstable and/or toxic degradation products may form due to degradation of drug which results into loss of therapeutic activity and lead to life threatening condition. Hence, it is important to establish the stability characteristics of drug in various conditions such as in temperature, light, oxidising agent and susceptibility across a wide range of pH values.Introduction:The aim of the proposed study was to develop simple, sensitive and economic stability indicating high performance thin layer chromatography (HPTLC) method for the quantification of Amoxapine in the presence of degradation products.Methods:Amoxapine and its degraded products were separated on precoated silica gel 60F254 TLC plates by using mobile phase comprising of methanol: toluene: ammonium acetate (6:3:1, v/v/v). The densitometric evaluation was carried out at 320 nm in reflectance/absorbance mode. The degradation products obtained as per ICH guidelines under acidic, basic and oxidative conditions have different Rf values 0.12, 0.26 and 0.6 indicating good resolution from each other and pure drug with Rf: 0.47. Amoxapine was found to be stable under neutral, thermal and photo conditions.Results:The method was validated as per ICH Q2 (R1) guidelines in terms of accuracy, precision, ruggedness, robustness and linearity. A good linear relationship between concentration and response (peak area and peak height) over the range of 80 ng/spot to 720 ng/spot was observed from regression analysis data showing correlation coefficient 0.991 and 0.994 for area and height, respectively. The limit of detection (LOD) and limit of quantitation (LOQ) for area were found to be 1.176 ng/mL and 3.565 ng/mL, whereas for height, 50.063 ng/mL and 151.707 ng/mL respectively.Conclusion:The statistical analysis confirmed the accuracy, precision and selectivity of the proposed method which can be effectively used for the analysis of amoxapine in the presence of degradation products.

Phytochemical, Analytical and Medicinal Studies of Holoptelea integrifolia Roxb. Planch - A Review

2019 ◽  
Vol 5 (4) ◽  
pp. 270-277 ◽  
Author(s):  
Vijay Kumar ◽  
Simranjeet Singh ◽  
Ragini Bhadouria ◽  
Ravindra Singh ◽  
Om Prakash
Keyword(s):  
Liquid Chromatography ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
High Performance ◽  
Biologically Active ◽  
Toxicological Studies ◽  
Wide Range ◽  
Layer Chromatography

Holoptelea integrifolia Roxb. Planch (HI) has been used to treat various ailments including obesity, osteoarthritis, arthritis, inflammation, anemia, diabetes etc. To review the major phytochemicals and medicinal properties of HI, exhaustive bibliographic research was designed by means of various scientific search engines and databases. Only 12 phytochemicals have been reported including biologically active compounds like betulin, betulinic acid, epifriedlin, octacosanol, Friedlin, Holoptelin-A and Holoptelin-B. Analytical methods including the Thin Layer Chromatography (TLC), High-Performance Thin Layer Chromatography (HPTLC), High-Performance Liquid Chromatography (HPLC) and Liquid Chromatography With Mass Spectral (LC-MS) analysis have been used to analyze the HI. From medicinal potency point of view, these phytochemicals have a wide range of pharmacological activities such as antioxidant, antibacterial, anti-inflammatory, and anti-tumor. In the current review, it has been noticed that the mechanism of action of HI with biomolecules has not been fully explored. Pharmacology and toxicological studies are very few. This seems a huge literature gap to be fulfilled through the detailed in-vivo and in-vitro studies.

scholarly journals Bio-Based Alternatives to Phenol and Formaldehyde for the Production of Resins

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2237 ◽  
Author(s):  
P. R. Sarika ◽  
Paul Nancarrow ◽  
Abdulrahman Khansaheb ◽  
Taleb Ibrahim
Keyword(s):  
Raw Materials ◽  
Phenol Formaldehyde ◽  
Raw Material ◽  
Wood Industry ◽  
Suitable Material ◽  
The Past ◽  
Wide Range ◽  
Recent Developments ◽  
Sustainable Materials ◽  
Materials Used

Phenol–formaldehyde (PF) resin continues to dominate the resin industry more than 100 years after its first synthesis. Its versatile properties such as thermal stability, chemical resistance, fire resistance, and dimensional stability make it a suitable material for a wide range of applications. PF resins have been used in the wood industry as adhesives, in paints and coatings, and in the aerospace, construction, and building industries as composites and foams. Currently, petroleum is the key source of raw materials used in manufacturing PF resin. However, increasing environmental pollution and fossil fuel depletion have driven industries to seek sustainable alternatives to petroleum based raw materials. Over the past decade, researchers have replaced phenol and formaldehyde with sustainable materials such as lignin, tannin, cardanol, hydroxymethylfurfural, and glyoxal to produce bio-based PF resin. Several synthesis modifications are currently under investigation towards improving the properties of bio-based phenolic resin. This review discusses recent developments in the synthesis of PF resins, particularly those created from sustainable raw material substitutes, and modifications applied to the synthetic route in order to improve the mechanical properties.

scholarly journals RELaTED Project: New Developments on Ultra-Low Temperature District Heating Networks

Proceedings ◽  
2020 ◽  
Vol 65 (1) ◽  
pp. 25
Author(s):  
Antonio Garrido Marijuan ◽  
Roberto Garay ◽  
Mikel Lumbreras ◽  
Víctor Sánchez ◽  
Olga Macias ◽  
...  
Keyword(s):  
Low Temperature ◽  
High Performance ◽  
Waste Heat ◽  
District Heating ◽  
Hot Water ◽  
Thermal Systems ◽  
Heating Source ◽  
Wide Range ◽  
Thermal Sources ◽  
Heating Networks

District heating networks deliver around 13% of the heating energy in the EU, being considered as a key element of the progressive decarbonization of Europe. The H2020 REnewable Low TEmperature District project (RELaTED) seeks to contribute to the energy decarbonization of these infrastructures through the development and demonstration of the following concepts: reduction in network temperature down to 50 °C, integration of renewable energies and waste heat sources with a novel substation concept, and improvement on building-integrated solar thermal systems. The coupling of renewable thermal sources with ultra-low temperature district heating (DH) allows for a bidirectional energy flow, using the DH as both thermal storage in periods of production surplus and a back-up heating source during consumption peaks. The ultra-low temperature enables the integration of a wide range of energy sources such as waste heat from industry. Furthermore, RELaTED also develops concepts concerning district heating-connected reversible heat pump systems that allow to reach adequate thermal levels for domestic hot water as well as the use of the network for district cooling with high performance. These developments will be demonstrated in four locations: Estonia, Serbia, Denmark, and Spain.

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