scholarly journals Mechanistic study of continuous polishing

2015 ◽  
Vol 3 ◽  
Author(s):  
Xiang Jiao ◽  
Jianqiang Zhu ◽  
Quantang Fan ◽  
Yangshuai Li
Keyword(s):  
Equilibrium State ◽  
High Precision ◽  
High Efficiency ◽  
Mechanistic Study ◽  
Surface Error ◽  
Surface Change ◽  
Flat Surfaces ◽  
Basic Features ◽  
Theoretical Foundations ◽  
Better Than

To establish the mechanism of surface change in a continuous polishing system, an ideal mathematical model is built based on Winkler’s hypothesis and the Preston equation. The basic features of the model are the change rates in the surface peak–valley (PV) values of the workpiece, conditioning disk and pitch lap, rather than the specific surface shapes. In addition, an equilibrium state exists in the system, indicating that the surface change rates are all zero. Under equilibrium, the surface of the lap could remain flat, and it is insensitive to the surface error of the workpiece. These characteristics lay the theoretical foundations for high-efficiency and high-precision polishing. The methods to obtain an equilibrium state with flat surfaces are then proposed and confirmed experimentally. High-precision surfaces better than $\frac{{\it\lambda}}{10}~({\it\lambda}=632.8~\text{nm})$ are consistently produced experimentally.

Processing of WC-Co Cemented Carbide Ball by EDR and RDP Lapping Modes

2009 ◽  
Vol 76-78 ◽  
pp. 258-263 ◽  
Author(s):  
Ju Long Yuan ◽  
Fan Yang ◽  
Zhi Wei Wang ◽  
Ke Feng Tang ◽  
Jia Jie Chen
Keyword(s):  
High Precision ◽  
High Efficiency ◽  
Processing Parameters ◽  
Batch Processing ◽  
Cemented Carbide ◽  
Abrasive Grain ◽  
End Products ◽  
Better Than

In order to get high precision balls used in oil exactor, Eccentric dual-rotating (EDR) V-groove lapping mode and Rotated dual-plates (RDP) lapping mode are applied for the batch processing of WC-Co cemented carbide balls of Φ35mm. After comparing two innovated modes, firstly EDR V-groove lapping mode is used in rough lapping stage for high efficiency, and then semi-finishing lapping stage, finishing lapping stage and polishing stage are carried out by RDP lapping mode. Through changing the processing parameters legitimately, including abrasive grain, adjustable rotating velocity and load, the rational course and parameters are defined, and WC-Co cemented carbide balls of Φ35mm satisfy the end products’ demand which means the sphericity is less than 1μm and the roughness of surface (Ra) is better than 50nm, so these balls can be applied in one-way hydraulic value used in oil exactor.

scholarly journals High-Efficiency Intracavity Continuous-Wave Green-Light Generation by Quasiphase Matching in a Bulk Periodically Poled MgO:LiNbO3 Crystal

2008 ◽  
Vol 2008 ◽  
pp. 1-4 ◽  
Author(s):  
Shaowei Chu ◽  
Ying Zhang ◽  
Bin Wang ◽  
Yong Bi
Keyword(s):  
High Efficiency ◽  
Continuous Wave ◽  
Green Light ◽  
Frequency Doubling ◽  
Green Laser ◽  
Periodically Poled ◽  
Output Stability ◽  
532 Nm ◽  
Better Than ◽  
Quasiphase Matching

908 mW of green light at 532 nm were generated by intracavity quasiphase matching in a bulk periodically poled MgO:LiNbO3 (PPMgLN) crystal. A maximum optical-to-optical conversion efficiency of 33.5% was obtained from a 0.5 mm thick, 10 mm long, and 5 mol% MgO:LiNbO3 crystal with an end-pump power of 2.7 W at 808 nm. The temperature bandwidth between the intracavity and single-pass frequency doubling was found to be different for the PPMgLN. Reliability and stability of the green laser were evaluated. It was found that for continuous operation of 100 hours, the output stability was better than 97.5% and no optical damage was observed.

scholarly journals Siberian Snakes, Figure-8 and Spin Transparency Techniques for High Precision Experiments with Polarized Hadron Beams in Colliders

Symmetry ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 398
Author(s):  
Yaroslav S. Derbenev ◽  
Yury N. Filatov ◽  
Anatoliy M. Kondratenko ◽  
Mikhail A. Kondratenko ◽  
Vasiliy S. Morozov
Keyword(s):  
High Precision ◽  
High Energy Physics ◽  
High Efficiency ◽  
High Energy ◽  
Polarized Beams ◽  
Polarization Control ◽  
Spin Polarized ◽  
High Flexibility ◽  
Spin Flips ◽  
Energy Physics

We present a review of the possibilities to conduct experiments of high efficiency in the nuclear and high energy physics with spin-polarized beams in a collider complex, configuration of which includes Siberian snakes or figure-8 collider ring. Special attention is given to the recently elicited advantageous possibility to conduct high precision experiments in a regime of the spin transparency (ST) when the design global spin tune is close to zero. In this regime, the polarization control is realized by use of spin navigators (SN), which are compact special insertions of magnets dedicated to a high flexibility spin manipulation including frequent spin flips.

Comparison of Probabilistic and Possibility Theory-Based Methods for Design Against Catastrophic Failure Under Uncertainty

1999 ◽  
Author(s):  
Efstratios Nikolaidis ◽  
Harley Cudney ◽  
Sophie Chen ◽  
Raphael T. Haftka ◽  
Raluca Rosca
Keyword(s):  
Probabilistic Models ◽  
Failure Modes ◽  
Possibility Theory ◽  
Probabilistic Methods ◽  
Sufficient Information ◽  
Catastrophic Failure ◽  
Design Problems ◽  
Available Information ◽  
Theoretical Foundations ◽  
Better Than

Abstract This paper compares probabilistic and possibility-based methods for design against catastrophic failure under uncertainty. It studies the effect of the amount of information on the effectiveness of each method. The study is confined to problems where the boundary between survival and failure is sharp. First, the paper examines the theoretical foundations of probability and possibility. It also compares the two methods when they are used to assess the risk of a system. Finally, it compares the two methods on two design problems. A major difference between probability and possibility is in the axioms about the union of events. Because of this difference, probability and possibility calculi are fundamentally different and one cannot simulate possibility calculus using probabilistic models. It is shown that possibility-based methods can be less conservative than probability-based methods in systems with many failure modes. On the other hand, possibility-based methods tend to be more conservative than probability-based methods in systems that fail only if many unfavorable events occur simultaneously. Probabilistic methods are better than possibility-based methods if sufficient information is available. However, the latter can be better if little information is available. A principal reason is that it is easier to identify the most conservative possibilistic model than the most conservative probabilistic model that is consistent with the available information.

scholarly journals Silica Nanoflowers-Stabilized Pickering Emulsion as a Robust Biocatalysis Platform for Enzymatic Production of Biodiesel

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1026 ◽  
Author(s):  
Lihui Wang ◽  
Xinlong Liu ◽  
Yanjun Jiang ◽  
Peng Liu ◽  
Liya Zhou ◽  
...  
Keyword(s):  
High Efficiency ◽  
Pickering Emulsion ◽  
Biodiesel Production ◽  
Candida Antarctica Lipase ◽  
Waste Oil ◽  
Enzymatic Production ◽  
Mild Conditions ◽  
Experimental Yield ◽  
Optimized Conditions ◽  
Better Than

Enzymatic production of biodiesel had attracted much attention due to its high efficiency, mild conditions and environmental protection. However, the high cost of enzyme, poor solubility of methanol in oil and adsorption of glycerol onto the enzyme limited the popularization of the process. To address these problems, we developed a silica nanoflowers-stabilized Pickering emulsion as a biocatalysis platform with Candida antarctica lipase B (CALB) as model lipase for biodiesel production. Silica nanoflowers (SNFs) were synthesized in microemulsion and served as a carrier for CALB immobilization and then used as an emulsifier for constructing Pickering emulsion. The structure of SNFs and the biocatalytic Pickering emulsion (CALB@SNFs-PE) were characterized in detail. Experimental data about the methanolysis of waste oil to biodiesel was evaluated by response surface methodology. The highest experimental yield of 98.5 ± 0.5% was obtained under the optimized conditions: methanol/oil ratio of 2.63:1, a temperature of 45.97 °C, CALB@SNFs dosage of 33.24 mg and time of 8.11 h, which was closed to the predicted value (100.00%). Reusability test showed that CALB@SNFs-PE could retain 76.68% of its initial biodiesel yield after 15 cycles, which was better than that of free CALB and N435.

The Super-Thin Rod Cylindrical Honing Technology Research

2012 ◽  
Vol 503-504 ◽  
pp. 764-767 ◽  
Author(s):  
Lin Zhu ◽  
Lin Pan
Keyword(s):  
Surface Roughness ◽  
High Precision ◽  
High Efficiency ◽  
Slenderness Ratio ◽  
Flexible Production ◽  
Technology Research ◽  
Processing Efficiency ◽  
Stroke Length ◽  
Roundness Error ◽  
Cylindrical Grinding

The super-thin rod cylindrical grinding is a problem in the machining, super-thin rod with large slenderness ratio, poor rigidity, large roundness error after grinding, and with low processing efficiency. This study uses cylindrical honing processing super-thin rod parts, and designing the super-thin rod cylindrical honing head, carrying on a honing test. The results show that the super-thin rod cylindrical coarse honing capacity reach up to 0.002mm/double stroke(length 1698mm), surface roughness reach up to Ra 0.8 ~ 0.025μm after honing, roundness error reach up to 2μm. It fully shows that super-thin rod cylindrical honing technology has high precision, low surface roughness, flexible production processing and high efficiency.

scholarly journals Relationship Of Theoretical Foundations Of Lexicology And The Development Of Verbal Creativity In Elder Preschool Children

2021 ◽  
Vol 03 (04) ◽  
pp. 496-503
Author(s):  
Olga Terekhova ◽  
◽  
◽  
Keyword(s):  
Word Formation ◽  
Russian Language ◽  
New Words ◽  
Verbal Creativity ◽  
Living Things ◽  
Linguistic Patterns ◽  
Basic Features ◽  
The Right ◽  
Relationship Of ◽  
Theoretical Foundations

The word, as a structural unit of language, has a number of basic features. The Russian language is alive, and, like all living things, it develops and undergoes changes in the process of its development. Preschoolers come up with new words based on linguistic patterns. The teacher in the classroom on the development of speech should redirect the word-creation of children in the right direction, showing them the current rules of word-formation of their native language.

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