scholarly journals Scratch Morphology Transformation: An Alternative Method of Scratch Processing on Optical Surface

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1030
Author(s):  
Guangqi Zhou ◽  
Ye Tian ◽  
Feng Shi ◽  
Ci Song ◽  
Guipeng Tie ◽  
...  
Keyword(s):  
Optical Quality ◽  
The Other ◽  
Normal Process ◽  
Time Cost ◽  
Optical Surface ◽  
Magnetorheological Finishing ◽  
Engineering Applications ◽  
Economical Alternative ◽  
Fabrication Time ◽  
Process Method

The scratches on an optical surface can worsen the performance of elements. The normal process method is removing scratches entirely. However, it is a tough and high-cost requirement of removing extremely deep scratches and maintaining all the other excellent indicators at the same time. As the alternative of removing, we propose the method of scratch morphology transformation to diminish the drawbacks induced by scratches. We measure the morphology of scratches, establish the transformation models and transform them to the needed shape. In engineering applications, transformation can solve scratch drawbacks or limitations in an efficient and effective way. Then, residual scratches become acceptable. The transformation can also be amalgamated into the error figuring processes. Typical scratch transforming examples are experimented and AFM measurement is conducted. We explore the rule of scratch morphology transformation by two typical fabrication means: magnetorheological finishing (MRF) and HF etching. This morphology transforming method is an economical alternative for current defect-free fabrication. That will significantly decrease fabrication time, cost and risk, while the optical quality maintain.

scholarly journals Activation of the lac Repressor in the Transgenic Mouse

Genetics ◽  
1997 ◽  
Vol 147 (1) ◽  
pp. 297-304
Author(s):  
Heidi Scrable ◽  
Peter J Stambrook
Keyword(s):  
Copy Number ◽  
Methylation Status ◽  
Lac Repressor ◽  
The Other ◽  
Lac Operon ◽  
Normal Process ◽  
Divergent Sequence ◽  
Somatic Tissues ◽  
New Material ◽  
Bacterial Sequence

Abstract We have introduced sequences encoding the lac repressor of Escherichia coli into the genome of the mouse. One sequence was derived from the bacterial lac operon and the other was created by reencoding the amino acid sequence of lacI with mammalian codons. Both versions are driven by an identical promoter fragment derived from the human β-actin locus and were microinjected into genetically identical pronuclear stage embryos. All transgenes utilizing the bacterial coding sequence were transcriptionally silent in all somatic tissues tested. The sequence re-encoded with mammalian codons was transcriptionally active at all transgene loci and expressed ubiquitously. Using methylation-sensitive enzymes, we have determined the methylation status of lac repressor transgenes encoded by either the bacterial or mammalian sequence. The highly divergent bacterial sequence was hypermethylated at all transgene loci, while the mammalian sequence was only hypermethylated at a high copy number locus. This may reflect a normal process that protects the genome from acquiring new material that has an abnormally divergent sequence or structure.

Comparative Surface Imaging Study of Multifocal Diffractive Intraocular Lenses

2021 ◽  
Author(s):  
Hyeck Soo Son ◽  
Jung Min Lee ◽  
Ramin Khoramnia ◽  
Chul Young Choi
Keyword(s):  
Imaging Study ◽  
The Other ◽  
Intraocular Lenses ◽  
Optical Surface ◽  
Diffractive Optic ◽  
Atomic Force ◽  
Acceptable Range ◽  
Different Types ◽  
Concentric Pattern

Abstract Purpose To analyse and compare the surface topography and roughness of three different types of diffractive multifocal IOLs. Methods Using scanning electron microscope (SEM, Inspect F, 5.0 KV, maximum magnification up to 20,000) and atomic force microscope (AFM, Park Systems, XE-100, non-contact, area profile comparison, 10 × 10 µm, 40 × 40 µm), the surface quality of the following diffractive IOLs was studied: the AcrySof IQ PanOptix (Alcon, USA), the AT LARA 829MP (Carl Zeiss Meditec, Germany), and Tecnis Symfony (Johnson&Johnson Vision, USA). The measurements were made over three representative areas (central non-diffractive optic, central diffractive optic, and diffractive step) of each IOL. Roughness profile in terms of mean arithmetic roughness (Ra) and root-mean-squared roughness (Rq) values were obtained and compared statistically. Results In SEM examination, all IOLs showed a smooth optical surface without any irregularities at low magnification. At higher magnification, Tecnis Symfony showed unique highly regular, concentric, and lineate structures in the diffractive optic area which could not be seen in the other studied diffractive IOLs. The differences in the measured Ra and Rq values of the Tecnis Symfony were statistically significant compared to the other models (p < 0.05). Conclusion Various different topographical traits were observed in three diffractive multifocal IOLs. The Ra values of all studied IOLs were within an acceptable range. Tecnis Symfony showed statistically significant higher surface Ra values at both central diffractive optic and diffractive step areas. Furthermore, compared to its counterparts, Tecnis Symfony demonstrated highly ordered, concentric pattern in its diffractive surfaces.

scholarly journals Yield Prediction of Renewable Diesel From Hydrocracking Process as a Function of Pressure and Temperature Using Analytical Semi Empirical Model (ASEM)

2018 ◽  
Vol 67 ◽  
pp. 02019
Author(s):  
Handrianto Wijaya ◽  
Bambang Heru Susanto
Keyword(s):  
Empirical Model ◽  
The Other ◽  
Yield Prediction ◽  
Trial And Error ◽  
Time Cost ◽  
Renewable Diesel ◽  
Renewable Fuel ◽  
Hydrocracking Process ◽  
Using Data ◽  
Semi Empirical

The development of renewable fuels from biomass is very rapid, and becomes the main alternative to replace petroleum-derived fuels that are limited in stock. There has been a lot of experiments to optimize the production of renewable diesel, but it takes time, cost and a lot of trial and error in order to produce a good result. On the other hand, optimization using simulation is more cost and time effective. One of the processes in the production of this renewable fuel is hydrocracking. This experiment aims to study the effect of pressure and temperature in the hydrocracking process using the Analytical Semi Empirical Model (ASEM) method in representing the yield of the product. Mathematical models will be modified and validated using data from existing research. The results show that Analytical Semi Empirical Model can be used to predict the yield of product from hydrocracking, with all of the models show R2 higher than 0.95 and SSE lower than 3.

Optimising the Process Conditions in Ultra-Precision Grinding to Achieve Surface Finish of Optical Quality

2006 ◽  
Vol 304-305 ◽  
pp. 8-13 ◽  
Author(s):  
T. Jin ◽  
D.J. Stephenson
Keyword(s):  
Surface Roughness ◽  
Surface Finish ◽  
Material Removal ◽  
Removal Rate ◽  
Optical Quality ◽  
Process Conditions ◽  
Low Alloy Steel ◽  
Optical Surface ◽  
Precision Grinding ◽  
Ultra Precision

Optical surface finish below Ra 10nm can be achieved on a ‘Tetraform C’ grinder of ultra-high stiffness, when grinding a low alloy steel with or without the help of ELID (electrolytic in process dressing). Surface roughness generation modelling has been carried out to predict thepossible surface roughness values. Efforts have been made to transfer the process knowledge to different grinding mode using a rigid 5-axis Edgetek CNC grinder. The effects of material removal rate and grit size and also that of spark out passes on the surface roughness generated have been investigated.

Ultra-precision optical surface fabricated by hydrodynamic effect polishing combined with magnetorheological finishing

Optik ◽  
2018 ◽  
Vol 156 ◽  
pp. 374-383 ◽  
Author(s):  
Wenqiang Peng ◽  
Shengyi Li ◽  
Chaoliang Guan ◽  
Yuan Li ◽  
Xudong Hu
Keyword(s):  
Hydrodynamic Effect ◽  
Optical Surface ◽  
Magnetorheological Finishing ◽  
Ultra Precision

scholarly journals Making Sense of Prototyping Technologies for Product Design

1991 ◽  
Author(s):  
Matthew B. Wall ◽  
Karl T. Ulrich ◽  
Woodie C. Flowers
Keyword(s):  
Field Study ◽  
Product Design ◽  
Time Cost ◽  
User Survey ◽  
Systematic Method ◽  
Making Sense ◽  
Mechanical Products ◽  
Fabrication Time

Abstract Firms that design mechanical and electro-mechanical products confront a variety of difficult issues in their prototyping activities. For a given part, how can a choice among fabrication technologies be made? Where should investments in new prototyping technology be focused? How can new and existing prototyping technologies be evaluated? Our primary goal has been to develop a systematic method of evaluating prototyping processes in order to determine the best process for a given situation. This paper reports on a field study conducted at the Kodak Apparatus Division. Our data is drawn from (1) a user survey of prototyping perceptions and needs, (2) a survey to determine the importance of various prototype part performance attributes, and (3) estimates of the fabrication time, cost, and part performance for 104 parts and four prototyping processes.

scholarly journals Pengembangan desain sarana pengembalian buku di ruang baca perpustakaan Kota Yogyakarta

2017 ◽  
Vol 3 (2) ◽  
pp. 42
Author(s):  
Kristian Oentoro ◽  
Laurensius Windy O.H. ◽  
R. Tosan Tri Putro
Keyword(s):  
Open Access ◽  
Service System ◽  
The Other ◽  
Design Development ◽  
Front End ◽  
Library Users ◽  
Access Service ◽  
Library User ◽  
Yogyakarta City ◽  
Process Method

Yogyakarta city library applied an open access service system, in which the library users were given access to independently find and take the books in collection shelves. Those users were also asked to return the finished books to the returning books medium in the form of trolleys. Later these books in the trolleys would be returned by the librarians scheduled for shelving duty. Observation result showed that there are a lot of unreturned books because the trolleys of the returning mediums are too full. Librarian also faced many difficulties in classifying the book stacks before returned to the collection shelves because of their messy state. According to the design study and development employing front- end process method, process (Karl & Steven, 2008), this problem could be solved by developing design concept for books returning mediums in the form of shelves contained colors and book codes information according to the standard of Yogyakarta city library. The result design prototype trial showed the increasing library users’ interest to return the finished books to the returning books medium according to the color and code information. It would greatly help the librarians in classifying the books before the re-organizing in the collection shelves. Design development of the returning books medium would also open the opportunity to optimize the temporary flow of returning books which would be easily found by the other library users before the shelving schedule.Keywords: library, open access, book shelf, librarian, library user

scholarly journals Laser induced tunable Ge2Sb2Te5 phase-change gratings

2021 ◽  
Vol 2015 (1) ◽  
pp. 012154
Author(s):  
Pavel I. Trofimov ◽  
Irina G. Bessonova ◽  
Petr I. Lazarenko ◽  
Demid A. Kirilenko ◽  
Nikolay A. Bert ◽  
...  
Keyword(s):  
Thin Films ◽  
Phase Change ◽  
Surface Structures ◽  
The Other ◽  
Formation Mechanisms ◽  
Laser Polarization ◽  
Time Cost ◽  
Periodic Surface ◽  
Light Manipulation ◽  
High Flexibility

Abstract Periodic photonic nano- and microstructures are routinely used for light manipulation at the nanoscale. However, their fabrication process is demanding in terms of time, cost and facilities. Here we demonstrate a rapid laser-assisted method for fabrication of gratings in Ge2Sb2Te5 (GST) thin films, based on the formation of laser induced periodic surface structures (LIPSS). LIPSS formation mechanisms dependent on the wavelength of the operating laser, lead to high flexibility of the process, producing gratings with tunable period and orientation with respect to the initial laser polarization. The phase-change properties of GST, on the other hand, allows to fabricate phase gratings with strong modulation of refractive index, which are rewritable in nature.

Effective Computation of Solutions for Nonlinear Heat Transfer Problems in Fins

2014 ◽  
Vol 136 (9) ◽  
Author(s):  
Mustafa Turkyilmazoglu
Keyword(s):  
Heat Transfer ◽  
Approximate Solution ◽  
Differential Equations ◽  
Nonlinear Differential Equations ◽  
The Other ◽  
Engineering Applications ◽  
Nonlinear Heat Transfer ◽  
Base Functions ◽  
Transfer Problems

Fins are essentially used in diverse engineering applications to increase the heat transfer between the hot and cold media. In this paper, a technique for computing the analytic approximate solution of the nonlinear differential equations resulting from heat transfer problems, in particular through fins, is developed. The simplicity of the approach presented here is due to its base functions, which makes this method straightforward to apply and formulate without any need for discretization. Analysis of the error and comparisons with the other methods are presented. A few physically interesting fin problems of heat transfer are treated to illustrate that the proposed algorithm generates highly accurate solutions.

III. Report on Martensitic Cast Irons

1941 ◽  
Vol 146 (1) ◽  
pp. 78-80
Author(s):  
J. G. Pearce
Keyword(s):  
Heat Treatment ◽  
The Other ◽  
Martensitic Structure ◽  
Cast Irons ◽  
Engineering Applications ◽  
Suitable Heat Treatment ◽  
Resistance To Wear

The resistance to wear, erosion, and abrasion which is characteristic of martensitic cast irons has brought about their employment in a number of engineering applications. Martensitic cast irons may be produced by heat treatment of an ordinary engineering pearlitic iron; or they may be specially produced and so treated that either of two varieties can be obtained. In one such variety the eutectic filling surrounding the primary grains is allowed to solidify white (cementitic), and in the other it is allowed to solidify grey (graphitic). There are thus two main classes of the martensitic cast irons which are specially made as such; they may be respectively described as “white” and “grey” in character, the former being the harder of the two. The “grey” variety can be made martensitic in the condition as cast, or alternatively a martensitic structure can be produced in it by suitable heat treatment.

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