Geodetically derived strain at Shelter Cove, California

1980 ◽  
Vol 70 (3) ◽  
pp. 893-901
Author(s):  
Richard A. Snay ◽  
Michael W. Cline
Keyword(s):  
Shear Strain ◽  
San Francisco ◽  
Geodetic Network ◽  
Geodetic Survey ◽  
Time Interval ◽  
National Geodetic Survey ◽  
Shear Strain Rate ◽  
San Andreas ◽  
The Mean ◽  
Homogeneous Strain

abstract To monitor crustal motion, the National Geodetic Survey observed, during 1976, a small geodetic network in the Shelter Cove area of northern California. This network straddles part of the fault which ruptured during the 1906 San Francisco earthquake. Analysis of the new survey data, combined with observations of a larger 1930 network, yields an estimate of N13.2°W ± 4.5° for the direction of maximum right-lateral shear strain through the area. This value agrees well with the average strike of the straddled fault and with the average strike of the San Andreas Fault's underwater path between Point Arena and Shelter Cove. The mean shear strain rate in this direction is 1.01 ± 0.18 (10−6) rad/yr for the 1930 to 1976 time interval where a region undergoing homogeneous strain more accurately describes the data than models allowing for the existence of surface slippage.

Accumulation of tectonic strain in California

1970 ◽  
Vol 60 (6) ◽  
pp. 1877-1896
Author(s):  
J. C. Savage ◽  
R. O. Burford
Keyword(s):  
Shear Strain ◽  
San Andreas Fault ◽  
Geodetic Survey ◽  
Strain Accumulation ◽  
Owens Valley ◽  
Imperial Valley ◽  
San Andreas ◽  
Period 1880 ◽  
Tectonically Active ◽  
Parkfield Earthquake

Abstract The shear-strain accumulation in five tectonically-active areas of California has been calculated from triangulation data supplied by the U. S. Coast and Geodetic Survey. Three of the areas lie along active sections of the San Andreas fault. Near Hollister, no appreciable strain accumulation was detected for the period 1930 to 1962. The movement of the fault blocks there appears to be accommodated by slip on the San Andreas and Calaveras faults. Near Cholame, the only appreciable accumulation of shear strain in the period 1932 to 1962 appears to be associated directly with slip on the San Andreas north of Cholame, slip which probably occurred during the 1934 Parkfield earthquake. Significant strain accumulation was confined to a zone centered on the San Andreas fault and extending 10 km on either side. Some of this strain was released in the 1966 Parkfield earthquake. In Imperial Valley, an average accumulation of γ = 0.4 μstrain per year right-lateral (referred to vertical planes parallel to the Imperial fault) shear strain extends over a zone perhaps 100 km wide centered on the Imperial fault. It appears that this shear pattern may be resolved into two zones of shear, one concentrated near the Imperial fault and the other near the San Andreas fault. No appreciable shear-strain accumulation was detected in the two areas that do not lie on the San Andreas fault—Santa Barbara channel for the period 1880 to 1923 and Owens Valley for the period 1934 to 1956.

The Interactions of In-Cylinder Flow and Fuel Spray in a Gasoline Direct Injection Engine With Variable Tumble

2015 ◽  
Vol 137 (7) ◽  
Author(s):  
Xianhui Zhang ◽  
Tianyou Wang ◽  
Ming Jia ◽  
Wei Li ◽  
Lei Cui ◽  
...  
Keyword(s):  
Shear Strain ◽  
Large Scale ◽  
Direct Injection ◽  
Cone Angle ◽  
Gasoline Direct Injection ◽  
Shear Strain Rate ◽  
Maximum Shear Strain ◽  
The Mean ◽  
Pod Analysis ◽  
Coherent Part

Particle image velocimetry (PIV) system was used to measure the tumble structure of the in-cylinder airflow in a four-valve optical gasoline direct injection (GDI) engine. The tumble ratio was controlled by a flap in the manifold and a baffle in the intake port. With proper orthogonal decomposition (POD) method, the velocity field was decomposed into four parts, i.e., the mean, coherent, transitional, and turbulent. The effect of tumble motion on the cycle-to-cycle variation (CCV) of airflow and spray was investigated by calculating the shear strain vorticity. The results indicate that the flow structure can be effectively changed through the combination of flap and baffle by forming a single large-scale tumble flow with the tumble ratio three times higher than the original one. According to POD analysis, it is revealed that the large-scale strong tumble motion leads to the energy occupation ratio of the mean part greatly increase by up to 30%, while the energy transferred to the coherent part is reduced. The above process also decreases the CCV of the coherent part by 50%; thus, the CCV of the whole airflow in the cylinder can be suppressed. A single large-scale tumble increases the maximum shear strain rate up to 2400 s−1. Meanwhile, the maximum vorticity increases to about 6000 s−1 by rolling up of the airflow. The contact area between spray droplets and air becomes larger, and the momentum exchanges between them contribute to wider sprays cone angle and shorter penetration distance when the flap is closed. The statistics of the measurements illustrate that a single large-scale tumble can promote the formation of homogeneous mixture and reduce the fluctuation between multicycles.

PALEOSEISMIC EXCAVATIONS ACROSS THE SAN ANDREAS FAULT ON THE SAN FRANCISCO PENINSULA, WOODSIDE, CALIFORNIA

2018 ◽  
Author(s):  
Carol S. Prentice ◽  
◽  
Robert R. Sickler ◽  
Kevin B. Clahan ◽  
Alexandra Pickering ◽  
...  
Keyword(s):  
San Francisco ◽  
San Andreas Fault ◽  
San Andreas

scholarly journals TEVAR versus open repair of blunt traumatic descending aortic injury in polytraumatic patients involved in motor vehicle accidents

2021 ◽  
Vol 29 (1) ◽  
Author(s):  
Imthiaz Manoly ◽  
Mohamed El Tahan ◽  
Maymoona Al Shuaibi ◽  
Fatimah Adel ◽  
Mohammed Al Harbi ◽  
...  
Keyword(s):  
Blood Transfusion ◽  
Hospital Stay ◽  
Open Repair ◽  
Motor Vehicle ◽  
Aortic Injury ◽  
Motor Vehicle Accidents ◽  
Time Interval ◽  
Vehicle Accidents ◽  
Severity Scores ◽  
The Mean

Abstract Background Thoracic endovascular aortic repair (TEVAR) is the standard-of-care for treating traumatic aortic injury (TAI). Few retrospective studies compared TEVAR to open repair in blunt traumatic aortic injury (BTAI). Our objectives were to compare the early outcomes of TEVAR for blunt traumatic descending aortic injury to open repair (OR) in polytraumatic patients involved in motor vehicle accidents (MVA). Results Between February 2005 and April 2017, 71 patients with TAI due to MVA presented to our institution. All patients with descending aortic injuries were considered for open repair (n = 41) or TEVAR (n = 30) if there was no contraindication. The primary outcome was mortality, and secondary outcomes were stroke, paraplegia, intensive care unit (ICU), and hospital stay. The mean age was 28.4 ± 10.1 years in the OR group and 33.3 ± 16.6 years in TEVAR-group (P = 0.13). The injury severity scores were 41 ± 10 in the OR group and 33 ± 17 in the TEVAR group (P = 0.03). Patients in the OR group underwent emergency repair with a mean time of 0.56 ± 0.18 days from arrival. The TEVAR group had a longer time interval between arrival and procedure (2.1 ± 1.7 days, P = 0.001). The OR group had more blood transfusion (24 (58.5%) vs. 8 (27.5%), P = 0.002), renal impairment (6 (14.6%) vs. 1 (5.50%), P = 0.23), and wound infection (21 (51.2%) vs. 3 (10%), P < 0.001). Three TEVAR patients had a perioperative stroke compared to two patients in the OR group (P = 0.64). There was no difference in the mean ICU (6 ± 8.9 vs. 5.3 ± 2.9 days; P = 0.1) or hospital stay (20.1 ± 12.3 vs. 20.1 ± 18.3, P = 0.62) between the two groups. There were four deaths in the OR group and none in the TEVAR group (P = 0.13). Conclusion The results of TEVAR were comparable with the open repair for traumatic aortic injury with good early postoperative outcomes. TEVAR repair could be associated with lower mortality, blood transfusion, and infective complications. However, the complexity of the injury and technical challenges were higher in the open group.

Is there a difference in range of motion, neck pain, and outcomes in patients with ossification of posterior longitudinal ligament versus those with cervical spondylosis, treated with plated laminoplasty?

2013 ◽  
Vol 35 (1) ◽  
pp. E9 ◽  
Author(s):  
Takahito Fujimori ◽  
Hai Le ◽  
John E. Ziewacz ◽  
Dean Chou ◽  
Praveen V. Mummaneni
Keyword(s):  
Neck Pain ◽  
Range Of Motion ◽  
Clinical Outcomes ◽  
San Francisco ◽  
Japanese Orthopaedic Association ◽  
Minimum Clinically Important Difference ◽  
Posterior Longitudinal Ligament ◽  
Flexion Angle ◽  
Radiographic Outcomes ◽  
The Mean

Object There are little data on the effects of plated, or plate-only, open-door laminoplasty on cervical range of motion (ROM), neck pain, and clinical outcomes. The purpose of this study was to compare ROM after a plated laminoplasty in patients with ossification of posterior longitudinal ligament (OPLL) versus those with cervical spondylotic myelopathy (CSM) and to correlate ROM with postoperative neck pain and neurological outcomes. Methods The authors retrospectively compared patients with a diagnosis of cervical stenosis due to either OPLL or CSM who had been treated with plated laminoplasty in the period from 2007 to 2012 at the University of California, San Francisco. Clinical outcomes were measured using the modified Japanese Orthopaedic Association (mJOA) scale and neck visual analog scale (VAS). Radiographic outcomes included assessment of changes in the C2–7 Cobb angle at flexion and extension, ROM at C2–7, and ROM of proximal and distal segments adjacent to the plated lamina. Results Sixty patients (40 men and 20 women) with an average age of 63.1 ± 10.9 years were included in the study. Forty-one patients had degenerative CSM and 19 patients had OPLL. The mean follow-up period was 20.9 ± 13.1 months. The mean mJOA score significantly improved in both the CSM and the OPLL groups (12.8 to 14.5, p < 0.01; and 13.2 to 14.2, respectively; p = 0.04). In the CSM group, the mean VAS neck score significantly improved from 4.2 to 2.6 after surgery (p = 0.01), but this improvement did not reach the minimum clinically important difference (MCID). Neither was there significant improvement in the VAS neck score in the OPLL group (3.6 to 3.1, p = 0.17). In the CSM group, ROM at C2–7 significantly decreased from 32.7° before surgery to 24.4° after surgery (p < 0.01). In the OPLL group, ROM at C2–7 significantly decreased from 34.4° to 20.8° (p < 0.01). In the CSM group, the change in the VAS neck score significantly correlated with the change in the flexion angle (r = − 0.31) and the extension angle (r = − 0.37); however, it did not correlate with the change in ROM at C2–7 (r = − 0.1). In the OPLL group, the change in the VAS neck score did not correlate with the change in the flexion angle (r = 0.03), the extension angle (r = − 0.17), or the ROM at C2–7 (r = − 0.28). The OPLL group had a significantly greater loss of ROM after surgery than did the CSM group (p = 0.04). There was no significant correlation between the change in ROM and the mJOA score in either group. Conclusions Plated laminoplasty in patients with either OPLL or CSM decreases cervical ROM, especially in the extension angle. Among patients who have undergone laminoplasty, those with OPLL lose more ROM than do those with CSM. No correlation was observed between neck pain and ROM in either group. Neither group had a change in neck pain that reached the MCID following laminoplasty. Both groups improved in neurological function and outcomes.

Multi-GNSS Single-Difference Baseline Processing at NGS with newly developed M-PAGES software

2021 ◽  
Author(s):  
Bryan Stressler ◽  
Andria Bilich ◽  
Clement Ogaja ◽  
Jacob Heck
Keyword(s):  
Geodetic Survey ◽  
Integer Ambiguity ◽  
National Geodetic Survey ◽  
Processing Strategy ◽  
Dual Frequency ◽  
Software Suite ◽  
Legacy Software ◽  
Double Differences ◽  
Single Difference ◽  
Gps Observations

&lt;p&gt;The U.S. National Geodetic Survey (NGS) has historically processed dual-frequency GPS observations in a double-differenced mode using the legacy software called the Program for the Adjustment of GPS Ephemerides (PAGES). As part of NGS&amp;#8217; modernization efforts, a new software suite named M-PAGES (i.e., Multi-GNSS PAGES) is being developed to replace PAGES. M-PAGES consists of a suite of C++ and Python libraries, programs, and scripts built to process observations from all GNSS constellations. The M-PAGES team has developed a single-difference baseline processing strategy that is suitable for multi-GNSS. This approach avoids the difficulty of forming double-differences across systems or frequencies, which may inhibit integer ambiguity resolution. The M-PAGES suite is expected to deploy to NGS&amp;#8217; Online Positioning User Service (OPUS) later this year. Here, we present the processing strategy being implemented along with a performance evaluation from sample baseline solutions obtained from data collected within the NOAA CORS Network.&lt;/p&gt;

Crustal structure southwest of the San Andreas fault from quarry blasts

1964 ◽  
Vol 54 (1) ◽  
pp. 67-77
Author(s):  
Robert M. Hamilton ◽  
Alan Ryall ◽  
Eduard Berg
Keyword(s):  
San Francisco ◽  
Crustal Structure ◽  
San Andreas Fault ◽  
P Wave ◽  
Geological Survey ◽  
San Andreas ◽  
Crustal Model ◽  
Crystalline Crust ◽  
The U.S

abstract To determine a crustal model for the southwest side of the San Andreas fault, six large quarry blasts near Salinas, California, were recorded at 27 seismographic stations in the region around Salinas, and along a line northwest of the quarry toward San Francisco. Data from these explosions are compared with results of explosion-seismic studies carried out by the U.S. Geological Survey on a profile along the coast of California from San Francisco to Camp Roberts. The velocity of Pg, the P wave refracted through the crystalline crust, in the Salinas region is 6.2 km/sec and the velocity of Pn is about 8.0 km/sec. Velocities of the direct P wave in near-sur-face rocks vary from one place to another, and appear to correlate well with gross geologic features. The thickness of the crust in the region southwest of the San Andreas fault from Salinas to San Francisco is about 22 kilometers.

scholarly journals Effect of Injection Pressure of Infiltration Anesthesia to the Jawbone

2016 ◽  
Vol 63 (3) ◽  
pp. 131-138 ◽  
Author(s):  
Kenji Yoshida ◽  
Eri Tanaka ◽  
Hiroyoshi Kawaai ◽  
Shinya Yamazaki
Keyword(s):  
Local Anesthetic ◽  
White Male ◽  
Injection Pressure ◽  
Time Interval ◽  
Time Intervals ◽  
Lidocaine Concentration ◽  
The Mean ◽  
High Concentrations ◽  
Infiltration Anesthesia ◽  
Local Anesthetic Infiltration

To obtain effective infiltration anesthesia in the jawbone, high concentrations of local anesthetic are needed. However, to reduce pain experienced by patients during local anesthetic administration, low-pressure injection is recommended for subperiosteal infiltration anesthesia. Currently, there are no studies regarding the effect of injection pressure on infiltration anesthesia, and a standard injection pressure has not been clearly determined. Hence, the effect of injection pressure of subperiosteal infiltration anesthesia on local anesthetic infiltration to the jawbone was considered by directly measuring lidocaine concentration in the jawbone. Japanese white male rabbits were used as test animals. After inducing general anesthesia with oxygen and sevoflurane, cannulation to the femoral artery was performed and arterial pressure was continuously recorded. Subperiosteal infiltration anesthesia was performed by injecting 0.5 mL of 2% lidocaine containing 1/80,000 adrenaline, and injection pressure was monitored by a pressure transducer for 40 seconds. After specified time intervals (10, 20, 30, 40, 50, and 60 minutes), jawbone and blood samples were collected, and the concentration of lidocaine at each time interval was measured. The mean injection pressure was divided into 4 groups (100 ± 50 mm Hg, 200 ± 50 mm Hg, 300 ± 50 mm Hg, and 400 ± 50 mm Hg), and comparison statistical analysis between these 4 groups was performed. No significant change in blood pressure during infiltration anesthesia was observed in any of the 4 groups. Lidocaine concentration in the blood and jawbone were highest 10 minutes after the infiltration anesthesia in all 4 groups and decreased thereafter. Lidocaine concentration in the jawbone increased as injection pressure increased, while serum lidocaine concentration was significantly lower. This suggests that when injection pressure of subperiosteal infiltration anesthesia is low, infiltration of local anesthetic to the jawbone may be reduced, while transfer to oral mucosa and blood may be increased.

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