The Stability of Ion Projection Lithography Masks

1986 ◽  
Vol 76 ◽  
Author(s):  
J. N. Randall ◽  
D. Bellavance ◽  
R. Sivasankar

ABSTRACTIon projection lithography (IPL) has demonstrated the ability to replicate high resolution patterns with very short exposure times. Computer modeling of masks used in a hypothetical IPL system Is accomplished to estimate mask distortion during fabrication and exposure. Radiation cooling is shown to play an important role in temperature control. Two different methods of mask temperature control are examined. Results suggest a high degree of pattern stability can be expected from this type of mask.

Author(s):  
Mihir Parikh

It is well known that the resolution of bio-molecules in a high resolution electron microscope depends not just on the physical resolving power of the instrument, but also on the stability of these molecules under the electron beam. Experimentally, the damage to the bio-molecules is commo ly monitored by the decrease in the intensity of the diffraction pattern, or more quantitatively by the decrease in the peaks of an energy loss spectrum. In the latter case the exposure, EC, to decrease the peak intensity from IO to I’O can be related to the molecular dissociation cross-section, σD, by EC = ℓn(IO /I’O) /ℓD. Qu ntitative data on damage cross-sections are just being reported, However, the microscopist needs to know the explicit dependence of damage on: (1) the molecular properties, (2) the density and characteristics of the molecular film and that of the support film, if any, (3) the temperature of the molecular film and (4) certain characteristics of the electron microscope used


Author(s):  
P.R. Swann ◽  
A.E. Lloyd

Figure 1 shows the design of a specimen stage used for the in situ observation of phase transformations in the temperature range between ambient and −160°C. The design has the following features a high degree of specimen stability during tilting linear tilt actuation about two orthogonal axes for accurate control of tilt angle read-out high angle tilt range for stereo work and habit plane determination simple, robust construction temperature control of better than ±0.5°C minimum thermal drift and transmission of vibration from the cooling system.


2020 ◽  
Vol 4 (141) ◽  
pp. 114-122
Author(s):  
DAR’YA LEBEDEVA ◽  
◽  
ANNA KARPUNICHEVA

Large forces and significant thermal effects are created on the rolls when rolling sheets. The higher the stability of the rolls, the less downtime during their rerolling and higher productivity. (Research purpose) The research purpose is in analyzing the ways of restoring rolls and choose the most appropriate method for restoring these parts. (Materials and methods) The article presents the analysis of the scientific and technical literature on the topic of rolling production, methods for restoring large-sized machine parts of machine-building and metallurgical industries that work in difficult conditions and are subject to a high degree of wear. Authors try to solve the problem by means of comparative and logical analysis based on theoretical and empirical methods of scientific research. (Results and discussion) The article presents two groups of methods for restoring rolled rolls: banding and surfacing the working layer of the roll. Authors have analyzed each method in terms of technology, equipment, and feasibility. The article presents the advantages and disadvantages of the methods under consideration. (Conclusions) The most acceptable way to restore parts with a high degree of wear is surfacing. It is most efficient to apply submerged surfacing using an additional hot additive. Such surfacing, despite some complication of the equipment design, allows to deposit the metal on the roll with low heat input and in most cases in one pass. Surfacing using an additional hot additive allows to increase the productivity of the process by up to 250 percent while reducing the penetration depth by 2-3 times and saving energy by up to 40 percent.


Author(s):  
Y.V. Kutuzova ◽  
◽  
I.V. Dutchin ◽  
E.L. Sorokin ◽  
◽  
...  

Purpose.To conduct a comparative analysis of the effectiveness of assessing the stability of the tear film using corneotopography and the classic Norn test in patients with myopia and myopic astigmatism before keratorefractive surgery. Material and methods. The study included 26 patients planned for keratorefractive surgery for myopia and myopic astigmatism, aged 18 to 47 years. 7 people there was a mild degree of myopia, in 14 people – medium degree, in 5 people – high degree. The average degree of corneal astigmatism was 2.25 diopters. The stability of the pre-corneal tear film was assessed using computed keratotopography and Norn's test – the tear film rupture time (TFRT) was deter- mined. A standard questionnaire was also used to assess the severity of symptoms of dry eye syndrome. A comparison was made of the indicators of the stability of the tear film obtained by the methods of corneotopography and the Norn's test, with their subsequent comparison with the data of the questionnaire. Results. In 17 patients (65.4%), the TFRT index corresponded to the age norm. In the remaining 9 people (34.6%), indicators of stability of the tear film were reduced both by corneotopography (12±4 sec) and by Norn's test (13.5±4.5 sec), and there were also subjective signs of dry eye syndrome according to data questionnaire. The data turned out to be comparable. Conclusions. 1. Among the total population of patients, 34.6% were persons with impaired tear film stability and subjective manifestations of dry eye syndrome. 2. Assessment of the stability of the tear film, determined using the method of corneal topography, showed a high degree of comparability with the results of Norn's test. A significant advantage of the keratotopography method is its non-invasiveness. 3. It is necessary to pay attention to the condition of the ocular surface and identify risk groups to avoid chronicity or aggravation of existing disorders. Key words: dry eye syndrome, tear film, keratotopography, Norn's test.


2021 ◽  
Author(s):  
Maximillian Van Wyk de Vries ◽  
Shashank Bhushan ◽  
David Shean ◽  
Etienne Berthier ◽  
César Deschamps-Berger ◽  
...  

<p>On the 7<sup>th</sup> of February 2021, a large rock-ice avalanche triggered a debris flow in Chamoli district, Uttarakhand, India, resulting in over 200 dead or missing and widespread infrastructure damage. The rock-ice avalanche originated from a steep, glacierized north-facing slope with a history of instability, most recently a 2016 ice avalanche. In this work, we assess whether the slope exhibited any precursory displacement prior to collapse. We evaluate monthly slope motion over the 2015 and 2021 period through feature tracking of high-resolution optical satellite imagery from Sentinel-2 (10 m Ground Sampling Distance) and PlanetScope (3-4 m Ground Sampling Distance). Assessing slope displacement of the underlying rock is complicated by the presence of glaciers over a portion of the collapse area, which display surface displacements due to internal ice deformation. We overcome this through tracking the motion over ice-free portions of the slide area, and evaluating the spatial pattern of velocity changes in glaciated areas. Preliminary results show that the rock-ice avalanche bloc slipped over 10 m in the 5 years prior to collapse, with particularly rapid slip occurring in the summer of 2017 and 2018. These results provide insight into the precursory conditions of the deadly rock-ice avalanche, and highlight the potential of high-resolution optical satellite image feature tracking for monitoring the stability of high-risk slopes.</p>


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Glaucia A. Rocha-Selmi ◽  
Carmen S. Favaro-Trindade ◽  
Carlos R. F. Grosso

The interest in lycopene has increased in recent years due to studies that associate it with the reduction in risk of developing cardiovascular diseases and cancer. However, due to its high degree of unsaturation, this carotenoid is inclined to isomerize and oxidize during processing and storage, making it difficult to use in the food industry. Microencapsulation can improve this situation, increasing its stability and making incorporation into food formulations possible. Thus, the aim of this study was to microencapsulate lycopene by complex coacervation using gelatin and gum Arabic as the encapsulating agents. The microcapsules were evaluated based on the encapsulation efficiency and their morphology and then submitted to a stability test and applied in cake making. Most of the systems studied presented spherical microcapsules with defined walls. The encapsulation efficiency values were above 90%, and the average diameter of the capsules ranged from 61 to 144 μm. The stability test showed that microencapsulation offered greater protection to the lycopene as compared to its free form. The application of nonfreeze dried coacervated microcapsules in cake making was satisfactory, but the color transference was low when freezedried coacervated microcapsules were used.


2000 ◽  
Vol 53 (1-4) ◽  
pp. 605-608 ◽  
Author(s):  
W.H. Bruenger ◽  
M. Torkler ◽  
C. Dzionk ◽  
B.D. Terris ◽  
L. Folks ◽  
...  

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