scholarly journals A new leak-tight borehole casing at Dome Concordia station, Antarctica, for the SUBGLACIOR project

2014 ◽  
Vol 55 (68) ◽  
pp. 351-354 ◽  
Author(s):  
Romain Duphil ◽  
Philippe Possenti ◽  
Luc Piard
Keyword(s):  
Austral Summer ◽  
Summer Season ◽  
Compressed Air ◽  
New Method ◽  
Drilling Fluids ◽  
Polyethylene Pipes ◽  
New Type ◽  
New System

AbstractIn the frame of the SUBGLACIOR project, a new type of casing has been installed for testing during the 2013/14 austral summer season at Dome Concordia station, Antarctica. The SUBGLACIOR probe requires a full fluid column up to the surface, in order to circulate fluid for ice-chips recovery. This makes it essential that the casing is leak-tight through the porous firn column. We have evaluated existing solutions before opting to test a new method. This new system is made of polyethylene pipes which are welded together at the surface while the casing pipes are lowered into the reamed borehole. It is simple and lightweight and allows the casing to be installed quickly with optimum chance of being leak-tight. The installed casing has been tested both with compressed air and drilling fluids and has proven to work.

The CURSOR Radio Navigation and Tracking System

1992 ◽  
Vol 45 (2) ◽  
pp. 157-165 ◽  
Author(s):  
Peter J. Duffett-Smith ◽  
Graham Woan
Keyword(s):  
Motor Vehicle ◽  
Tracking System ◽  
Temporal Coherence ◽  
Radio Navigation ◽  
Radio Transmitters ◽  
Local Medium ◽  
New Type ◽  
Set Up ◽  
Conventional Systems ◽  
New System

We describe a new type of radio navigation and tracking system which, unlike conventional systems, does not depend on a costly infrastructure of coherent radio transmitters. This new system measures positions using spatial, rather than temporal, coherence and can therefore use any existing radio transmitters set up for any purpose. We describe the principles of operation, applications and present results obtained with a demonstration unit (in Cambridge) which can measure the position of a motor vehicle to a precision of about 5 m using local medium-wave public broadcast transmitters.

A Method of Improving Accuracy of Lapping Main Cylinder of Brake-Pump

2014 ◽  
Vol 875-877 ◽  
pp. 1377-1381
Author(s):  
Jian Dong Yang ◽  
Feng Xiang Li ◽  
Hui Yan
Keyword(s):  
Pressure Distribution ◽  
Machining Process ◽  
New Method ◽  
Existing Problems ◽  
Pressure Method ◽  
New Type ◽  
Improving Accuracy

This paper analyzes the existing problems of acting lapping pressure in lapping internal holes of main cylinder of brake-pump with solid abrasives, proposes a new type of solid abrasives supporting method, namely, three supportting points acting lapping pressure method. The method improves pressure distribution between solid abrasives and the surface of the machined workpiece,which is favorable to increase cylindricity of machined hole.Through actual machining process, new method is demonstrated increasing cylindricity accuracy of machined holes of main cylinder significantly.

An examination of the current National Operating Committee on Standards for Athletic Equipment system and a new pneumatic ram method for evaluating American football helmet performance to reduce risk of concussion

2016 ◽  
Vol 231 (2) ◽  
pp. 83-90 ◽  
Author(s):  
Thomas Blaine Hoshizaki ◽  
Clara Karton ◽  
R. Anna Oeur ◽  
Marshall Kendall ◽  
Lauren Dawson ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Significant Risk ◽  
Standard Test ◽  
American Football ◽  
New Method ◽  
Rotational Acceleration ◽  
Football Helmets ◽  
Athletic Equipment ◽  
New System

Brain injuries are prevalent in the sport of American football. Helmets have been used which effectively have reduced the incidence of traumatic brain injury, but have had a limited effect on concussion rates. In an effort to improve the protective capacity of American football helmets, a standard has been proposed by National Operating Committee on Standards for Athletic Equipment that may better represent helmet-to-helmet impacts common to football concussions. The purpose of this research was to examine the National Operating Committee on Standards for Athletic Equipment standard and a new impact method similar to the proposed National Operating Committee on Standards for Athletic Equipment standard to examine the information these methods provide on helmet performance. Five National Operating Committee on Standards for Athletic Equipment–certified American football helmets were impacted according to the National Operating Committee on Standards for Athletic Equipment standard test and a new method based on the proposed standard test. The results demonstrated that the National Operating Committee on Standards for Athletic Equipment test produced larger linear accelerations than the new method, which were a reflection of the stiffer compliance of the standard meant to replicate traumatic brain injury mechanisms of injury. When the helmets were impacted using a new helmet-to-helmet method, the results reflected significant risk of concussive injury but showed differences in rotational acceleration responses between different helmet models. This suggests that the new system is sensitive enough to detect the effect of different design changes on rotational acceleration, a metric more closely associated with risk of concussion. As only one helmet produced magnitudes of response lower than the National Operating Committee on Standards for Athletic Equipment pass/fail using the new system, and all helmets passed the National Operating Committee on Standards for Athletic Equipment standard, these results suggest that further development of helmet technologies must be undertaken to reduce this risk in the future. Finally, these results show that it would be prudent to use both standards together to address risk of injury from traumatic brain injury and concussion.

A New Method for Preparing Ge Nano-Crystallites Embedded in SiNY Matrices

1994 ◽  
Vol 358 ◽  
Author(s):  
Kunji Chen ◽  
Xuexuan Qu ◽  
Xinfan Huang ◽  
Zhifeng Li ◽  
Duan Feng
Keyword(s):  
Laser Annealing ◽  
Hydrogen Plasma ◽  
New Method ◽  
Transmission Electron ◽  
Scattering Spectra ◽  
Ion Laser ◽  
New Type ◽  
Raman Scattering Spectra ◽  
Average Size ◽  
20 Nm

ABSTRACTWe report a new method for synthesizing Ge nano-crystallites embedded in SiNy film matrices. On the basis of the effect of the reactant precursors and preferential chemical bonding of Si-N and Ge-Ge, thin films with Ge clusters embedded in SiNy matrices have been prepared in the PECVD system with reactant gases of SiH4, GeH4 and NH3 mixed in the hydrogen plasma. The as-deposited films were then crystallized by Ar ion laser annealing or thermal annealing technique to form nanometer-sized Ge crystallites.The composition and microstructures of these new type of sample were characterized by infrared absorption spectra, transmission electron microscopy, X-ray diffraction and Raman scattering spectra. The results indicated that the average size of Ge crystallites was estimated to be 2-20 nm depending on the deposition and annealing parameters and can be controlled by a designed manner.

Hydraulic System Simulation Analysis of Shearer's Cutting Part Based on AEMSim

2012 ◽  
Vol 268-270 ◽  
pp. 841-844
Author(s):  
Li Rong Wan ◽  
Xing Hua Wang ◽  
Jian Liang Li ◽  
Bin Zhang ◽  
Xian Peng Li
Keyword(s):  
Dynamic Property ◽  
Hydraulic System ◽  
Simulation Analysis ◽  
System Simulation ◽  
Fluid Simulation ◽  
New Method ◽  
Simulation Technology ◽  
Rigorous Analysis ◽  
Mining Machinery ◽  
New Type

Simulation analysis on the hydraulic system of shearer's cutting part was established based on the research of fluid simulation technology. The hydraulic model was built using the AMESim software. By verifying the results, a new method about the rigorous analysis of holistic dynamic property of the hydraulic system is developed and a new way to design new type mining machinery and improve its capabilities is provided.

A New Method for Quantitative X-Ray Fluorescence Analysis of Mixtures of Oxides or Other Compounds by Empirical Parameter Methods

1982 ◽  
Vol 26 ◽  
pp. 351-354 ◽  
Author(s):  
Michael Mantler
Keyword(s):  
Computer Program ◽  
Chemical Elements ◽  
Fluorescence Analysis ◽  
Theoretical Background ◽  
New Method ◽  
Fundamental Parameter ◽  
Mathematical Methods ◽  
Empirical Parameter ◽  
X Ray ◽  
New Type

Two principal mathematical methods are used for quantitative XRFA: fundamental parameter calculations and the evaluation of empirical parameter equations. A comprehensive computer program based upon fundamental parameter equations was introduced in 1976 by D. Laguitton and M. Mantler (LAMA-I) and improved by T. C. Huang in 1979 (LAMA-II). The present paper describes the features of the theoretical background of a computer program using a new type of empirical (alpha*-) parameter equations. It is essentially designed for convenient analysis of compounds including those containing chemical elements, that cannot be directly measured by conventional X-ray spectrometers, such as oxides, nitrides, and others. The program also communicates automatically with LAMA in order to establish theoretical tables of alpha*-coefficients as well as conventional alpha-coefficients.

scholarly journals Stopping Accidents before They Happen: Perceiving Lane-Level Moving Vehicle Danger Regions to Warn Surrounding Drivers and Pedestrians

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Chi Guo ◽  
Guangyi Cao ◽  
Jieru Zeng ◽  
Jinsong Cui ◽  
Rong Peng
Keyword(s):  
Real Time ◽  
Large Scale ◽  
The Internet ◽  
Active Safety ◽  
Internet Of Vehicles ◽  
Moving Vehicle ◽  
Moving Vehicles ◽  
Traditional Service ◽  
New Type ◽  
New System

Perceiving the location of dangerous moving vehicles and broadcasting this information to vehicles nearby are essential to achieve active safety in the Internet of Vehicles (IOV). To address this issue, we implement a real-time high-precision lane-level danger region service for moving vehicles. A traditional service depends on static geofencing and fails to deal with dynamic vehicles. To overcome this defect, we devised a new type of IOV service that manages to track dangerous moving vehicles in real time and recognize their danger regions quickly and accurately. Next, we designed algorithms to distinguish the vehicles in danger regions and broadcast the information to these vehicles. Our system can simultaneously manipulate a mass of danger regions for various dangerous vehicles and broadcast this information to surrounding vehicles at a large scale. This new system was tested in Shanghai, Guangzhou, Wuhan, and other cities; the data analysis is presented in this paper as well.

A New Type of Optimization Method Based on Conjugate Directions

2013 ◽  
Vol 347-350 ◽  
pp. 3029-3034
Author(s):  
Xin Pan
Keyword(s):  
Large Scale ◽  
Line Search ◽  
Optimization Method ◽  
New Method ◽  
Conjugate Directions ◽  
Exact Line Search ◽  
Large Scale Problems ◽  
New Type ◽  
Quadratic Termination

A new type of optimization method based on conjugate directions is proposed in this paper. It can be proved that this type of method has quadratic termination property without exact line search. The new method requires only the storage of 4 vectors such that it is suitable for large scale problems. Numerical experiences show that the new method is effective.

Sensitivity of middle atmosphere GW forcing to vertical model resolution

2020 ◽  
Author(s):  
Andrea Schneidereit ◽  
Hauke Schmidt ◽  
Claudia Stephan
Keyword(s):  
Zonal Wind ◽  
Middle Atmosphere ◽  
Wave Spectrum ◽  
Austral Summer ◽  
Vertical Gradient ◽  
Summer Season ◽  
Grid Spacing ◽  
Flux Divergence ◽  
The Mean ◽  
Horizontal Grid

<p>Several current general atmospheric circulation models provide sufficiently high resolutions to resolve important parts of the internal gravity wave spectrum allowing for numerical experiments without GW drag parameterizations. GWs start to be well resolved from horizontal wavelengths of about 7 times the horizontal grid spacing. How much does the resolved wave spectrum and its forcing on the mean circulation depend on the vertical resolution?</p><p>−1,The middle atmosphere summer hemisphere provides a suitable background to investigate this question. The mean stratospheric and mesospheric circulation is characterised by prevailing easterlies which prevent planetary wave propagation upwards and represents a mean state driven by IGWs. The sensitivity of the forcing by IGWs is analysed on the basis of the Eliassen-Palm (EP) flux divergence, which describes the forcing on the circulation by resolved eddies.<br>Model simulations are performed using the upper atmosphere version of the ICON (ICOsahedral Nonhydrostatic) general circulation model, UA-ICON (Borchert et al. 2019, GMD). The simulations start in October and run for an extended austral summer season until March with a horizontal grid spacing of roughly 20 km. The top of the model atmosphere is located at 150 km. Three different model configurations are used with 90, 180, and 360 vertical model layers. The mean vertical grid spacing ranges from roughly 1300 m (90 layers) to 320 m (360 layers) at stratospheric levels, and from roughly 2300 m to 500 m at mesospheric levels. Gravity wave drag parameterizations (orographic and non-orographic) are turned off. The resolved forcing on the mean state due to the EP flux divergence is decomposed into contributions of different scales with respect to horizontal wave numbers. For contributions of IGWs wave numbers above 20 are considered.</p><p>The stratospheric and mesospheric easterlies appear stronger in the lower resolution from October to the end of the austral summer season. Westerlies occur above the mesopause. This strong vertical gradient in the zonal mean zonal wind amplifies in the lower resolution. At the beginning of the simulation period, differences between the mean states are weak, of the order of 5 ms<sup>−1</sup> , and strengthen during the summer season. The forcing due to internal GWs appears stronger in the lower resolution at higher altitudes and amplifies in the region of the strong vertical gradient of the zonal mean zonal wind. Furthermore, wave spectra are discussed. In accordance with previous studies, an increased vertical resolution results in a reduction of the IGW forcing close to strong zonal mean zonal wind gradients in the upper mesosphere/lower thermosphere.</p>

Sign in / Sign up

Export Citation Format

Share Document