Research on the design of Kepler refractive shaping system with the long working focal depth

2021 ◽  
Author(s):  
Yihan Wang ◽  
Zhaofeng Cen ◽  
Xiaotong Li
Keyword(s):  
Focal Depth ◽  
Shaping System

AlCu Pattern Generation on 3D StructuredWafer Using Multi Level Exposure Method on Electrodeposited Polymer Material

2003 ◽  
Vol 766 ◽  
Author(s):  
Vineet Sharma ◽  
Arief B. Suriadi ◽  
Frank Berauer ◽  
Laurie S. Mittelstadt
Keyword(s):  
Line Width ◽  
Metal Film ◽  
Focal Depth ◽  
Cost Effective ◽  
Pattern Generation ◽  
Promising Technique ◽  
Critical Dimensions ◽  
Exposure Method ◽  
Multi Level ◽  
3D Surfaces

AbstractNormal photolithography tools have focal depth limitations and are unable to meet the expectations of high resolution photolithography on highly topographic structures. This paper shows a cost effective and promising technique of combining two different approaches to achieve critical dimensions of traces on slope pattern continuity on highly topographic structures. Electrophoretically deposited photoresist is used on 3-D structured wafers. This photoresist coating technique is fairly known in the MEMS industries to achieve uniform and conformal photoresist films on 3D surfaces. Multi step exposures are used to expose electrophoretically deposited photoresist. AlCu (Cu-0.5%), 0.47-0.53 μm thick metal film is deposited on 3D structured silicon substrate to plate photoresist. By combining these two novel methods, metal (AlCu) traces of 75 μm line width and 150 μm pitch (from top flat to down the slope) have been demonstrated on isotropically etched 350 μm deep trenches with 5-10% line width loss.

scholarly journals Analysis of Predistortion Techniques on Fresnel Zone Plates in Ultrasound Applications

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5066
Author(s):  
José Miguel Fuster ◽  
Sergio Pérez-López ◽  
Francisco Belmar ◽  
Pilar Candelas
Keyword(s):  
Intensity Distribution ◽  
Fresnel Zone ◽  
Focal Depth ◽  
Acoustic Intensity ◽  
Fresnel Zone Plates ◽  
Therapeutic Applications ◽  
Zone Plates ◽  
Ultrasound Applications

In this work, we analyze the effect of predistortion techniques on the focusing profile of Fresnel Zone Plates (FZPs) in ultrasound applications. This novel predistortion method is based on either increasing or decreasing the width of some of the FZP Fresnel rings by a certain amount. We investigate how the magnitude of the predistortion, as well as the number and location of the predistorted rings, influences the lens focusing profile. This focusing profile can be affected in different ways depending on the area of the lens where the predistortion is applied. It is shown that when the inner area of the lens, closer to its center, is predistorted, this technique allows the control of the focal depth at the main focus. However, when the predistortion is applied to an area farther from the center of the lens, the acoustic intensity distribution among the main focus and the closest adjacent secondary foci can be tailored at a certain degree. This predistortion technique shows great potential and can be used to control, modify and shape the FZP focusing profile in both industrial and therapeutic applications.

The 4 December 2015 Mw 7.1 Normal-Faulting Antarctic Plate Earthquake and Its Seismotectonic Implications

2020 ◽  
Vol 110 (3) ◽  
pp. 1090-1100
Author(s):  
Ronia Andrews ◽  
Kusala Rajendran ◽  
N. Purnachandra Rao
Keyword(s):  
Body Wave ◽  
Focal Depth ◽  
Normal Fault ◽  
Normal Faults ◽  
Oceanic Plate ◽  
Normal Faulting ◽  
Transform Faults ◽  
Wave Inversion ◽  
Spreading Ridges ◽  
Southeast Indian Ridge

ABSTRACT Oceanic plate seismicity is generally dominated by normal and strike-slip faulting associated with active spreading ridges and transform faults. Fossil structural fabrics inherited from spreading ridges also host earthquakes. The Indian Oceanic plate, considered quite active seismically, has hosted earthquakes both on its active and fossil fault systems. The 4 December 2015 Mw 7.1 normal-faulting earthquake, located ∼700  km south of the southeast Indian ridge in the southern Indian Ocean, is a rarity due to its location away from the ridge, lack of association with any mapped faults and its focal depth close to the 800°C isotherm. We present results of teleseismic body-wave inversion that suggest that the earthquake occurred on a north-northwest–south-southeast-striking normal fault at a depth of 34 km. The rupture propagated at 2.7  km/s with compact slip over an area of 48×48  km2 around the hypocenter. Our analysis of the background tectonics suggests that our chosen fault plane is in the same direction as the mapped normal faults on the eastern flanks of the Kerguelen plateau. We propose that these buried normal faults, possibly the relics of the ancient rifting might have been reactivated, leading to the 2015 midplate earthquake.

Focal shift and extended focal depth with tunable pupil filter

2008 ◽  
Vol 55 (17) ◽  
pp. 2857-2863 ◽  
Author(s):  
Maojin Yun ◽  
El-Hang Lee
Keyword(s):  
Focal Depth ◽  
Focal Shift

The Chelmsford-Lowell, Massachusetts, earthquake of 23 November 1980: Depth control and fault plane solution

1981 ◽  
Vol 71 (4) ◽  
pp. 1369-1372
Author(s):  
Jay J. Pulli ◽  
Michael J. Guenette
Keyword(s):  
New England ◽  
Fault Plane ◽  
Seismic Station ◽  
Focal Depth ◽  
Strike Slip ◽  
Fault Plane Solution ◽  
Origin Time ◽  
Small Magnitude ◽  
Depth Control ◽  
Plane Solution

abstract On 23 November 1980, a small (magnitude 2.9) earthquake occurred on the Chelmsford-Lowell, Massachusetts, border, approximately 10 km northeast of the MIT seismic station at Westford, Massachusetts (WFM). Thus we were able to accurately determine the focal depth, which is generally not the case in New England. Our hypocentral solution was latitude 41.63, longitude −71.36, depth 1.5 km, at origin time 00:39:32.0 UTC. The fault plane solution shows either strike-slip or dip-slip faulting with a P axis trending NE-SW, which is in agreement with overcoring measurements in a nearby granite quarry.

Differences in the rupture process for very deep earthquakes at the Peru-Brazil and Peru-Bolivia borders 

2021 ◽  
Author(s):  
Elisa Buforn ◽  
Carmen Pro ◽  
Hernando Tavera ◽  
Agustin Udias ◽  
Maurizio Mattesini
Keyword(s):  
Focal Depth ◽  
Vertical Plane ◽  
Rupture Process ◽  
The South ◽  
Nazca Plate ◽  
Deep Earthquakes ◽  
Pressure Axis ◽  
Rate Functions ◽  
The Moment ◽  
Epicentral Location

<p>We analyze the differences in the rupture process for twelve very deep earthquakes (h>500 km) at the Peruvian-Brazilian subduction zone. These earthquakes are produced by the contact between the Nazca and the South America Plates. We have estimated the focal mechanism from teleseismic waveforms, using the slip inversion over the rupture plane, testing rupture velocities ranging from 2.5 km/s to 4.5 km/s, and analyzing the slip distribution for each  rupture velocity. The selected 12 earthquakes have occurred in the period 1994- 2016, with magnitudes between 5.9 and 8.2 and focal depth 500- 700 km. They can be separated in two groups attending to their epicentral location. The first group is formed by 9 events located, in the Peruvian-Brazil border, with epicenters following a NNW-SSE alignment, parallel to the trench. Their focal mechanisms present solutions of normal faulting with planes oriented in NS direction, dipping about 45 degrees and with vertical pressure axis. The second group is formed by three earthquakes located to the south of the first group in northern Bolivia. Their mechanisms show dip-slip motion with a near vertical plane, oriented in NW-SE direction and the pressure axis dipping 45º to the NE. The moment rate functions correspond to single ruptures with time durations from 6s to 12s, with the exception of the large 1994 Bolivian earthquake (Mw = 8.2) which presents a complex and longer STF. The different mechanisms for the two groups of earthquakes confirm the different dip of the subducting Nazca plate at the two areas, with the steeper part at the southern one.  </p>

Shear velocity from differential travel times of short-period ScS-P in New Hebrides, Fiji-Tonga, and Banda Sea regions

1975 ◽  
Vol 65 (6) ◽  
pp. 1787-1796
Author(s):  
Mansur A. Choudhury ◽  
Georges Poupinet ◽  
Guy Perrier
Keyword(s):  
Upper Mantle ◽  
Focal Depth ◽  
Shear Velocity ◽  
Mean Value ◽  
Travel Times ◽  
Velocity Models ◽  
Depth Dependence ◽  
Short Period ◽  
New Hebrides ◽  
The Antarctic

abstract Behavior of P, S and ScS residuals as well as those of differential travel times of ScS-P from the Jeffreys-Bullen tables are analyzed. The phases have been read from short-period records of the Antarctic station, Dumont d'Urville (DRV); the earthquakes originating in New Hebrides, Fiji-Tonga, and Banda Sea regions. P residuals from all regions show a mean value of about −1 sec. On the contrary, S and ScS residuals, well correlated among themselves, show important regional as well as focal-depth dependence. ScS-P residuals from shallow and intermediate shocks are largely positive for New Hebrides and largely negative for Banda Sea; those from intermediate shocks are moderately positive for Fiji-Tonga. The anomalies disappear at depths greater than about 200 km. Upper mantle shear velocity models are presented for the three regions. The models are discussed in relation to a sinking lithosphere.

Focal mechanism and source depth of earthquakes from body- and surface-wave data

1971 ◽  
Vol 61 (5) ◽  
pp. 1369-1379 ◽  
Author(s):  
Nezihi Canitez ◽  
M. Nafi Toksöz
Keyword(s):  
Surface Wave ◽  
Body Wave ◽  
Source Parameters ◽  
Focal Depth ◽  
Spectral Ratio ◽  
The Body ◽  
Spectral Ratios ◽  
Motion Data ◽  
Wave Data ◽  
Surface Wave Data

abstract The determination of focal depth and other source parameters by the use of first-motion data and surface-wave spectra is investigated. It is shown that the spectral ratio of Love to Rayleigh waves (L/R) is sensitive to all source parameters. The azimuthal variation of the L/R spectral ratios can be used to check the fault-plane solution as well as for focal depth determinations. Medium response, attenuation, and source finiteness seriously affect the absolute spectra and introduce uncertainty into the focal depth determinations. These effects are nearly canceled out when L/R amplitude ratios are used. Thus, the preferred procedure for source mechanism studies of shallow earthquakes is to use jointly the body-wave data, absolute spectra of surface waves, and the Love/Rayleigh spectral ratios. With this procedure, focal depths can be determined to an accuracy of a few kilometers.

Sign in / Sign up

Export Citation Format

Share Document