Measurement of parallelism and perpendicularity of large-size workpieces by laser alignment method

2006 ◽  
Author(s):  
Yong Song ◽  
Qun Hao ◽  
Dacheng Li
Keyword(s):  
Alignment Method ◽  
Laser Alignment ◽  
Large Size

A quadrant detector based laser alignment method with higher sensitivity

Optik ◽  
2012 ◽  
Vol 123 (24) ◽  
pp. 2238-2240 ◽  
Author(s):  
Xiang Hao ◽  
Cuifang Kuang ◽  
Yulong Ku ◽  
Xu Liu ◽  
Yanghui Li
Keyword(s):  
Alignment Method ◽  
Laser Alignment ◽  
Higher Sensitivity

Fabrication Process for Large Size Mold and Alignment Method for Nanoimprint System

2010 ◽  
Vol 130 (8) ◽  
pp. 363-368 ◽  
Author(s):  
Kentaro Ishibashi ◽  
Mitsunori Kokubo ◽  
Hiroshi Goto ◽  
Jun Mizuno ◽  
Shuichi Shoji
Keyword(s):  
Fabrication Process ◽  
Alignment Method ◽  
Large Size

scholarly journals PENGARUH PEMUAIAN PANAS TERHADAP KELURUSAN POROS TURBIN UAP

2020 ◽  
Vol 14 (1) ◽  
pp. 71-76
Author(s):  
Dwijaya Febriansyah ◽  
Barman Tambunan ◽  
Rudias Harmadi ◽  
Budi Noviyantoro Fadjrin
Keyword(s):  
Steam Turbine ◽  
Vertical Plane ◽  
Alignment Method ◽  
Rotating Machines ◽  
Laser Alignment ◽  
Thermal Growth ◽  
Shaft Misalignment ◽  
Shaft Alignment ◽  
Cold Condition

Sebagian besar penyebab kegagalan pada mesin-mesin rotasi termasuk turbin uap adalah poros yang berputar dalam kondisi misalignment. Pada turbin uap, panas yang merambat pada casing dapat merubah dimensi turbin uap karena adanya pemuaian (thermal growth) sehingga mempengaruhi kelurusan poros saat berputar. Nilai thermal growth ini perlu diketahui sebagai salah satu spesifikasi dalam penyetelan poros sebelum turbin beroperasi. Dalam studi ini,  thermal growth pada turbin uap 3 MW diinvestigasi dengan mengukur kelurusan poros dalam kondisi panas setelah berhenti berputar dan dingin menggunakan metode laser alignment. Hasil pengukuran menunjukkan bahwa thermal growth memberikan pengaruh terhadap kelurusan poros karena adanya selisih nilai kelurusan poros saat kondisi panas dan dingin yaitu 1.0 thous (gap) dan 2.8 thous (offset) pada bidang vertikal kemudian -1.0 thous (gap) dan -2.7 thous (offset) pada bidang horisontal.Kata kunci : Turbin uap, Thermal growth, Kelurusan porosMost of the causes of rotating machines failure including steam turbine is shaft misalignment. In the steam turbine, heat that travels to the casing can change steam turbine dimension due to thermal growth which affects the shaft alignment. Thermal growth values needs to be known as one of the specifications in shaft alignment setup. In this study, thermal growth on 3 MW steam turbine was investigated by measuring the shaft alignment in hot after shut down and cold condition using laser alignment method. Results show that thermal growth has an influence on shaft alignment due to difference of alignment values when hot and cold conditions, namely 1.0 thous (gap) and 2.8 thous (offset.) in vertical plane then -1.0 thous (gap) and -2.7 thous (offset.) in horizontal plane.Key Words : Steam Turbine, Thermal growth, Shaft alignment 

scholarly journals EQ-SANS Detector Distance Check with Laser Alignment Method

2021 ◽  
Author(s):  
Gergely Nagy ◽  
William Heller ◽  
Carrie Gao ◽  
Timothy Carroll ◽  
Matt Kyte
Keyword(s):  
Alignment Method ◽  
Laser Alignment ◽  
Detector Distance

Coherency loss in γ' precipitates in nickel-base superalloy

1983 ◽  
Vol 41 ◽  
pp. 244-245
Author(s):  
R. A. Ricks ◽  
Angus J. Porter
Keyword(s):  
Lattice Mismatch ◽  
Lattice Parameter ◽  
Nickel Base Superalloy ◽  
Large Size ◽  
The Matrix ◽  
Nimonic 80A ◽  
Interfacial Dislocations ◽  
Nickel Base ◽  
Coherency Loss ◽  
Nimonic 115

During a recent investigation concerning the growth of γ' precipitates in nickel-base superalloys it was observed that the sign of the lattice mismatch between the coherent particles and the matrix (γ) was important in determining the ease with which matrix dislocations could be incorporated into the interface to relieve coherency strains. Thus alloys with a negative misfit (ie. the γ' lattice parameter was smaller than the matrix) could lose coherency easily and γ/γ' interfaces would exhibit regularly spaced networks of dislocations, as shown in figure 1 for the case of Nimonic 115 (misfit = -0.15%). In contrast, γ' particles in alloys with a positive misfit could grow to a large size and not show any such dislocation arrangements in the interface, thus indicating that coherency had not been lost. Figure 2 depicts a large γ' precipitate in Nimonic 80A (misfit = +0.32%) showing few interfacial dislocations.

Automatic analysis of Kikuchi diffraction patterns

1994 ◽  
Vol 52 ◽  
pp. 900-901
Author(s):  
H. Weiland ◽  
D. P. Field
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Spatial Resolution ◽  
Relevant Information ◽  
Crystalline Materials ◽  
Large Size ◽  
Transmission Electron ◽  
New Type ◽  
Diffraction Patterns ◽  
Orientation Determination

Recent advances in the automatic indexing of backscatter Kikuchi diffraction patterns on the scanning electron microscope (SEM) has resulted in the development of a new type of microscopy. The ability to obtain statistically relevant information on the spatial distribution of crystallite orientations is giving rise to new insight into polycrystalline microstructures and their relation to materials properties. A limitation of the technique in the SEM is that the spatial resolution of the measurement is restricted by the relatively large size of the electron beam in relation to various microstructural features. Typically the spatial resolution in the SEM is limited to about half a micron or greater. Heavily worked structures exhibit microstructural features much finer than this and require resolution on the order of nanometers for accurate characterization. Transmission electron microscope (TEM) techniques offer sufficient resolution to investigate heavily worked crystalline materials.Crystal lattice orientation determination from Kikuchi diffraction patterns in the TEM (Figure 1) requires knowledge of the relative positions of at least three non-parallel Kikuchi line pairs in relation to the crystallite and the electron beam.

Immunoprobe localization in mammalian embryos

1990 ◽  
Vol 48 (3) ◽  
pp. 32-33
Author(s):  
Patricia G. Calarco ◽  
Margaret C. Siebert
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Thin Sections ◽  
Relative Lack ◽  
Large Size ◽  
Mammalian Embryos ◽  
Antigen Localization ◽  
Difficult Challenge ◽  
Lowicryl K4m ◽  
Fertilized Egg

Visualization of preimplantation mammalian embryos by electron microscopy is difficult due to the large size of the ircells, their relative lack of internal structure, and their highly hydrated cytoplasm. For example, the fertilized egg of the mouse is a single cell of approximately 75μ in diameter with little organized cytoskelet on and apaucity ofor ganelles such as endoplasmic reticulum (ER) and Golgi material. Thus, techniques that work well on tissues or cell lines are often not adaptable to embryos at either the LM or EM level.Over several years we have perfected techniques for visualization of mammalian embryos by LM and TEM, SEM and for the pre-embedding localization of antigens. Post-embedding antigenlocalization in thin sections of mouse oocytes and embryos has presented a more difficult challenge and has been explored in LR White, LR Gold, soft EPON (after etching of sections), and Lowicryl K4M. To date, antigen localization has only been achieved in Lowicryl-embedded material, although even with polymerization at-40°C, the small ER vesicles characteristic of embryos are unrecognizable.

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