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Blockage Corrections for Three-Dimensional-Flow Closed-Throat Wind Tunnels, With Consideration of the Effect of Compressibility

Description: "Theoretical blockage corrections are presented for a body of revolution and for a three-dimensional unswept wing in a circular or rectangular wind tunnel. The theory takes account of the effects of the wake and of the compressibility of the fluid, and is based on the assumption that the dimensions of the model are small in comparison with those of the tunnel throat. Formulas are given for correcting a number of the quantities, such as dynamic pressure and Mach number, measured in wing-tunnel tests. The report presents a summary and unification of the existing literature on the subject" (p. 771).
Date: 1950
Creator: Herriot, John G.
Partner: UNT Libraries Government Documents Department

Correction of Downwash in Wind Tunnels of Circular and Elliptic Sections

Description: The downwash velocity distribution behind the wing was determined for the free jet and for the closed tunnel of both circular and elliptic cross sections. The wing was placed at the center of the tunnel. The theory makes it possible to determine the downwash at any point in the jet. The computations were performed for points in the plane determined by the jet axis and the center-of-pressure line of the wing.
Date: July 1936
Creator: Lotz, Irmgard
Partner: UNT Libraries Government Documents Department

Determination of Jet-Boundary Corrections to Cowling-Flap-Outlet Pressures by an Electrical Analogy Method

Description: Report presenting corrections to the velocities near a cowling-flap tip in order to determine jet-boundary corrections to cowling-flap-outlet pressures. The presence of the low-energy air leaving the flap opening was taken into account by so shaping the nacelle model that its outer surface represented the stream surface leaving the flap tip. Copper was found unsatisfactory for use as electrode material.
Date: February 1944
Creator: Katzoff, S. & Finn, Robert S.
Partner: UNT Libraries Government Documents Department

Jet-Boundary-Induced-Upwash Velocities for Swept Reflection-Plane Models Mounted Vertically in 7- by 10-Foot, Closed, Rectangular Wind Tunnels

Description: Note presenting numerical values of the calculated boundary-induced-upwash velocities necessary for the determination of the jet-boundary corrections for swept reflection-plane models mounted vertically in 7- by 10-foot, closed, rectangular wing tunnels in chart form. Results regarding the correction factors for accurate calculations are also provided.
Date: November 1948
Creator: Polhamus, Edward C.
Partner: UNT Libraries Government Documents Department

Charts for Determining Jet-Boundary Corrections for Complete Models in 7- by 10-Foot Closed Rectangular Wind Tunnels

Description: Report presenting calculations of numerical values of the jet-boundary corrections to the angle of attack and the induced-drag, rolling-moment, and yawing-moment coefficients for complete airplane or wing models in 7- by 10-foot closed rectangular wind tunnels. The results showed that the wing area was the most important variable, as has usually been assumed in previous calculations. When the corrections were based on wing area, the effect of most of the other variables was negligible.
Date: September 1945
Creator: Gillis, Clarence L.; Polhamus, Edward C. & Gray, Joseph L., Jr.
Partner: UNT Libraries Government Documents Department

Operations with the digital orbit feedback system in the NSLS x-ray ring

Description: The digital filtering and eigenvector decomposition-based orbit correction is performed by two dedicated HP 742/743 rt micros which communicate with Motorola CPU based orbit-measuring and orbit-correction systems. The correction algorithm in the DFbk was orthogonalized with respect of the analog global harmonic feedback. Operational results concerning improvements in the noise suppression at low frequencies and especially in the dc drift as well as in the orbit stability are shown. Efforts are underway to improve the resolution of the orbit measuing system and the sampling rate using 16 bit 400 kHz ADC`s which will allow orbit sampling with high resolution at 4 kHz frequency.
Date: May 1, 1996
Creator: Bozoki, E.; Rammamorthy, S.; Singh, O.; Tang, Y. & Friedman, A.
Partner: UNT Libraries Government Documents Department

Education in the Texas prison system

Description: The purpose of this study has been to determine the nature and extent of educational opportunity offered to prison inmates in the Texas Department of Corrections, and as far as is possible, to evaluate the effectiveness of the program....Both primary and secondary data were used. Primary data were obtained by correspondence and personal interviews with TDC officials and staff members. Secondary data were obtained from annual reports submitted to the Texas Prison Board and the Board of Pardons and Paroles by the Department of Welfare, of which the Educational Department is a branch, from the Echo, prison inmate publication, and from mimeographed material prepared by prison officials.
Date: August 1960
Creator: Beets, Hughla Fae
Partner: UNT Libraries

Global DC closed orbit correction experiment on the NSLS x-ray ring

Description: In this note are described the global DC closed orbit correction experiments conducted on the X-ray ring at National Synchrotron Light Source (NSLS). The beam response matrix, defined as beam motion at BPM locations per unit kick by corrector magnets, was measured and then inverted using the technique of singular value decomposition (SVD). The product of the inverted matrix and the difference orbit gives the incremental kick strengths necessary to correct the orbit. As a result, the r.m.s. orbit error around the ring was reduced from 208 {mu}m to 61 {mu}m.
Date: September 15, 1992
Creator: Chung, Y.; Decker, G. & Evans, K.
Partner: UNT Libraries Government Documents Department

For a more perfect union : correctional reform

Description: The ACIR Library is composed of publications that study the interactions between different levels of government. This document addresses correctional reform.
Date: August 1971
Creator: United States. Advisory Commission on Intergovernmental Relations.
Partner: UNT Libraries Government Documents Department

Wind-Tunnel Corrections at High Subsonic Speeds Particularly for an Enclosed Circular Tunnel

Description: A review of existing publications on wind-tunnel corrections is followed by an approximate method for determining the corrections due to model and wake displacement and to lift. Relations are investigated for fuselages and wings of various spans in closed circular tunnels. A comparison is made between the computations and the tests in the DVL high-speed wind tunnel.
Date: February 1952
Creator: Göthert, Bernhard Hermann
Partner: UNT Libraries Government Documents Department

Jet-boundary corrections for complete and semispan swept wings in closed circular wind tunnels

Description: Report presenting tables and curves that give values of the induced-upwash-velocity factors, due to jet boundary, at the horizontal center plane of a closed circular wind tunnel and of a closed bipolar wing tunnel. The application of induced-upwash-velocity factors to the determination of jet-boundary corrections is also discussed.
Date: September 1951
Creator: Sivells, James C. & Salmi, Rachel M.
Partner: UNT Libraries Government Documents Department

An investigation of aircraft heaters 17: experimental inquiry into steady state unidirectional heat-meter corrections

Description: Report divided into two sections. One discusses a correction that must be applied to a heat meter when it is used at temperatures other than temperatures at which it was calibrated. The other section contains the results of an application of the two methods of correcting the heat-transfer rates for contact and heat-meter resistance to experimental data.
Date: August 1944
Creator: Boelter, L. M. K.; Poppendiek, H. F. & Gier, J. T.
Partner: UNT Libraries Government Documents Department

Linear Coupling Correction With N-Turn Maps.

Description: The linear one-turn map of a storage ring contains coupling information on which a correction algorithm can be based. In principal, the one-turn matrix can be fitted from turn-by-turn data of beam position monitors after a kick was applied. However, the so obtained coupling information often sinks into the noise floor. The signal-to-noise ratio of the coupling information can be greatly enhanced by fitting maps for larger turn numbers N, equal to half the beat period. With the so obtained N-turn map an automated global coupling correction is possible without the need for a tune change. This is demonstrated for the Relativistic Heavy Ion Collider where the algorithm is implemented for operational use at injection.
Date: May 12, 2003
Creator: Fischer, Wolfram
Partner: UNT Libraries Government Documents Department

Alpha Dithering to Correct Low-Opacity 8 Bit Compositing Errors

Description: This paper describes and analyzes a dithering technique for accurately specifying small values of opacity ({alpha}) that would normally not be possible because of the limited number of bits available in the alpha channel of graphics hardware. This dithering technique addresses problems related to compositing numerous low-opacity semitransparent polygons to create volumetric effects with graphics hardware. The paper also describes the causes and a possible solution to artifacts that arise from parallel or distributed volume rendering using bricking on multiple GPU's.
Date: March 31, 2003
Creator: Williams, P L; Frank, R J & LaMar, E C
Partner: UNT Libraries Government Documents Department

Viscosity Corrections to Cone Probes on Rarefied Supersonic Flow at a Nominal Mach Number of 4

Description: Note presenting data obtained for the viscosity corrections to cone probes in supersonic rarefied air flow at a nominal Mach number of 4. The test models consisted of a set of seven geometrically similar 5 degree semivertex-angle cones. Results regarding cone surface pressure distributions, calibration data for geometrically similar cones, orifices size effect, and tests at other Mach numbers are provided.
Date: November 1954
Creator: Talbot, L.
Partner: UNT Libraries Government Documents Department

Selective Versus Wholesale Error Correction of Grammar and Usage in the Papers of Adult Intermediate Level ESL Writing Students

Description: Over 13-weeks a control group (n=7) had all errors corrected, while an experimental group (n=9) had only article and sentence construction (run-on sentences, fragments, comma splices) errors corrected. Separating the two types of errors is essential, since the latter (representing grammar) are subject to theories of acquisition and the former (representing usage) are not. One-way analyses of variance ran on pretest versus posttest found no significant difference in either groups' article errors; however, the experimental group had significantly fewer sentence construction errors, implying that teachers should be sensitive to both the correction technique and error type; researchers should not combine the two error types in gathering data.
Date: August 1990
Creator: Whitus, Jerry D. (Jerry Dean)
Partner: UNT Libraries

Gluon density in nuclei

Description: In this talk we present our detailed study (theory and numbers) on the shadowing corrections to the gluon structure functions for nuclei. Starting from rather controversial information on the nucleon structure function which is originated by the recent HERA data, we develop the Glauber approach for the gluon density in a nucleus based on Mueller formula and estimate the value of the shadowing corrections in this case. Then we calculate the first corrections to the Glauber approach and show that these corrections are big. Based on this practical observation we suggest the new evolution equation which takes into account the shadowing corrections and solve it. We hope to convince you that the new evolution equation gives a good theoretical tool to treat the shadowing corrections for the gluons density in a nucleus and, therefore, it is able to provide the theoretically reliable initial conditions for the time evolution of the nucleus-nucleus cascade. The initial conditions should be fixed both theoretically and phenomenologically before to attack such complicated problems as the mixture of hard and soft processes in nucleus-nucleus interactions at high energy or the theoretically reliable approach to hadron or/and parton cascades for high energy nucleus-nucleus interaction. 35 refs., 24 figs., 1 tab.
Date: October 1996
Creator: Ayala, A. L.; Ducati, M. B. G. & Levin, E. M.
Partner: UNT Libraries Government Documents Department

Linear optics correction in the CEBAF accelerator

Description: During commissioning of the CEBAF accelerator, correcting dispersion, momentum compaction and betatron beam envelopes was essential for robust operation. To speed the diagnostic process we developed a method which allows one to track and correct the machine optics on-line. The method is based on measuring the propagation of 30 Hz modulated betatron oscillations. The beam optics of the accelerator was altered to decrease lattice sensitivity at critical points and to simplify control of the betatron function match. The calculation of the Courant-Snyder invariant from signals of each pair of beam position monitors was used for a correction of the betatron functions. The experience of optics correction and the study of long and short term machine reproducibility obtained during 1996 and early 1997 are also discussed. With minor modifications this method can also be used for on-line optics measurement and correction in circular accelerators.
Date: June 1, 1997
Creator: Lebedev, V.A.; Bickley, M. & Bisognano, J.
Partner: UNT Libraries Government Documents Department

Correction of vertical crossing induced dispersion in LHC

Description: Beam crossing schemes in the LHC interaction regions impose non-zero vertical closed orbit in the low-{beta} triplets, which excite a perturbative periodic dispersion ; the phenomenon is described and quantified in detail. It is shown that this dispersion reaches values at the limit of tolerances in the nominal optics of Version 5.0 of the LHC ring, and prohibitively large values in particular in the low- {beta} quadrupoles and interaction regions in the foreseen extreme {beta}-squeeze case ({beta}{sup *} = 0.25 m). Such behaviour justifies including a local correction in the LHC design, in order to damp the effect and confine it as much as possible in the vicinity of the excitation sources (the low-{beta} triplets). An optical compensation scheme based on the use of skew quadrupoles is described in detail, as well as the entailed residual dispersion.
Date: November 1, 1997
Creator: Meot, F.
Partner: UNT Libraries Government Documents Department

THE COUPLING CORRECTION SYSTEM AT RHIC: RESULTS FOR THE RUN 2000 AND PLANS FOR 2001.

Description: The RHIC coupling correction system has been commissioned during the year 2000 run, which marked the successful first year of operation of the machine. The RHIC coupling correction system is described with particular emphasis on its flexibility, which allows using both global and local coupling compensation techniques. Coupling measurements and correction data are presented for the RHIC Blue and Yellow rings, together with the procedure used to reduce the minimum tune separation to 0.001, the typical resolution for tune measurements during run 2000. They further demonstrate how local coupling compensation in the interaction regions substantially reduces the strength of the skew quadrupole families used for global coupling compensation.
Date: June 18, 2001
Creator: PILAT,F.; FISCHER,W.; PEGGS,S.; PTITSYN,V. & TEPIKIAN,S.
Partner: UNT Libraries Government Documents Department