Matter Outflows from AGN: A Unifying Model

We discuss a self-consistent unified model of the matter outflows from AGNs based on a theoretical approach and involving data on AGN evolution and structure. The model includes a unified geometry, two-phase gas dynamics, radiation transfer, and absorption spectrum calculations in the UV and X-ray bands. We briefly discuss several questions about the mass sources of the flows, the covering factors, and the stability of the narrow absorption details.Comment: 6 figures, accepted for publication in Astrophysics and Space Scienc

Limits on the production of scalar leptoquarks from Z (0) decays at LEP

A search has been made for pairs and for single production of scalar leptoquarks of the first and second generations using a data sample of 392000 Z0 decays from the DELPHI detector at LEP 1. No signal was found and limits on the leptoquark mass, production cross section and branching ratio were set. A mass limit at 95% confidence level of 45.5 GeV/c2 was obtained for leptoquark pair production. The search for the production of a single leptoquark probed the mass region above this limit and its results exclude first and second generation leptoquarks D0 with masses below 65 GeV/c2 and 73 GeV/c2 respectively, at 95% confidence level, assuming that the D0lq Yukawa coupling alpha(lambda) is equal to the electromagnetic one. An upper limit is also given on the coupling alpha(lambda) as a function of the leptoquark mass m(D0)

Search for a heavy neutral gauge boson in the dielectron channel with 5.4 fb-1 of ppbar collisions at sqrt(s) = 1.96 TeV

We report the results of a search for a heavy neutral gauge boson Z' decaying into the dielectron final state using data corresponding to an integrated luminosity of 5.4 fb-1 collected by the D0 experiment at the Fermilab Tevatron Collider. No significant excess above the standard model prediction is observed in the dielectron invariant-mass spectrum. We set 95% C.L. upper limits on \sigma (ppbar -> Z') X BR(Z' -> ee) depending on the dielectron invariant mass. These cross section limits are used to determine lower mass limits for Z' bosons in a variety of models with standard model couplings and variable strength.Comment: 8 pages, 4 figure

Search for leptophobic Z ' bosons decaying into four-lepton final states in proton-proton collisions at root s=8 TeV

Peer reviewe

Productivity and injectivity of horizontal wells. Quarterly report, April 1, 1995--June 30, 1995

The following activities have been carried out in the last three months: Work on developing a three-dimensional Voronoi grid simulator is progressing. Extensive testing of the grid generation and visualization modules of the simulator is continuing while modifications and improvements are being made to these capabilities; The recently developed semi-analytical method for calculating critical cresting rates is being extended for the case of simultaneous gas and water coning toward a horizontal well; The accuracy of available correlations and analytical models for breakthrough times of horizontal wells is being investigated through simulations of a field case; Work on developing methods for coupling between reservoir and the werbore through a network modeling approach is progressing. The current stage of the study involves evaluation of available analytical methods; The necessary modifications have been made to the rig at the Marathon facility and the high rate two-phase flow experiments are about to commence; new correlations for wall friction and interfacial friction factors have been developed for the stratified flow in horizontal and inclined pipes. After further testing this new approach will be used in our mechanistic model; and this quarterly report has been entirely devoted to the task fisted in the last item above and we only present an abridged version of the Masters report of Mr. Liang-Biao Ouyang on which it is based. The complete study will be included in the next Annual Report of the Project

Productivity and injectivity of horizontal wells. Quarterly report, July 1--September 30, 1995

During this quarter the authors have extended their earlier semi-analytical method for determining critical cresting rates in horizontal wells to the case of both water and gas cresting. The method and the procedure will be briefly described below. They also show the application of the method to an example problem and compare the results with direct numerical simulation

Productivity and injectivity of horizontal wells. Quarterly report, July 1--September 30, 1996

This quarterly report reports on the efforts on Task 2, effects of reservoir heterogeneities on performance prediction of horizontal wells. Performance prediction of horizontal and non-conventional wells based on both analytical and numerical tools rarely match actual performance. Even a history matched case with sufficient production data fails to give reliable predictions for long times. In this study the authors explore reasons for the inability of predictive tools to make accurate predictions. They consider a case where a vertical well has been drilled and cored. Then, they generate twenty consistent geostatistical descriptions of permeability and porosity that are all constrained to hard data obtained from the vertical well. Simulations with these realizations show large differences in production rate, WOR and GOR predictions as a result of variations in reservoir properties. It is also shown that the effect of well index (WI) on simulation results is large. Furthermore, for the example considered, analytical models for critical rate and productivity calculations were found to have limited practical use

Productivity and injectivity of horizontal wells. Quarterly report, October 1--December 31, 1996

This report describes progress on Tasks 1 and 4, Correlations for cresting behavior in horizontal wells. Research work on developing coarse grid methods to study cresting in horizontal wells was continued. The previous correlations for optimum grid size, breakthrough time, and post breakthrough behavior (i.e., water-oil ratio) were further tested and optimized. Procedures to derive pseudo-functions either using numerical correlations or coarse grid simulations have been proposed and successfully tested. The results reported here and other calculations show that the correlations developed in this work can be applied to a wide range of conditions for predicting the water break-through time (BT) and the water-oil-ratio (PBB) for horizontal wells. All of the correlations are based on the assumption of two-phase, two-dimensional flow in homogeneous reservoirs

Productivity and injectivity of horizontal wells. Quarterly report, January 1, 1995--March 31, 1995

This report presents skin factor calculations for vertical, horizontal, and deviated wells. Calculations for perforation, damage zone, crushed zone, non-darcy flow, and pressure drop due to the gravel packs are included