Review of biorthogonal coupled cluster representations for electronic excitation

Single reference coupled-cluster (CC) methods for electronic excitation are based on a biorthogonal representation (bCC) of the (shifted) Hamiltonian in terms of excited CC states, also referred to as correlated excited (CE) states, and an associated set of states biorthogonal to the CE states, the latter being essentially configuration interaction (CI) configurations. The bCC representation generates a non-hermitian secular matrix, the eigenvalues representing excitation energies, while the corresponding spectral intensities are to be derived from both the left and right eigenvectors. Using the perspective of the bCC representation, a systematic and comprehensive analysis of the excited-state CC methods is given, extending and generalizing previous such studies. Here, the essential topics are the truncation error characteristics and the separability properties, the latter being crucial for designing size-consistent approximation schemes. Based on the general order relations for the bCC secular matrix and the (left and right) eigenvector matrices, formulas for the perturbation-theoretical (PT) order of the truncation errors (TEO) are derived for energies, transition moments, and property matrix elements of arbitrary excitation classes and truncation levels. In the analysis of the separability properties of the transition moments, the decisive role of the so-called dual ground state is revealed. Due to the use of CE states the bCC approach can be compared to so-called intermediate state representation (ISR) methods based exclusively on suitably orthonormalized CE states. As the present analysis shows, the bCC approach has decisive advantages over the conventional CI treatment, but also distinctly weaker TEO and separability properties in comparison with a full (and hermitian) ISR method

The Function of Social Behavior in Water Resource Development

Preface: This report is an analysis of a social survey of the middle and lower Bear River Basin of southeastern Idaho and northern Utah concerning the problem of water resource development in a semiarid region of the Western United States. The survey part of the study, carried out in the summer of 1966, dealt with both general social factors and a specific proposal made by the Bureau of Reclamation for developing water resources of the Bear River. In many respects this proposal and the resulting behavior is typical of other western river basin projects, in some other ways, however, it is also unique. It is expected that the broad exploratory nature of this study will provide a useful background for other studies with more specialized and limited goals. The limited application of research to the behavioral problems of water resources research has guided the wide focus of this problem. This monograph reports a considerable amount of data. It is recommended that the reader interested in less detail might well confine himself to the champter summaries and the final chapter on conclusions. In some cases, in concluding or projecting, the writers have taken the liberty to speculate beyond the strict confines of the data, including some prespectives they have obtained in the process of the study. These occasions are indicated for the reader

Elevated neutrophil and monocyte counts in peripheral blood are associated with poor survival in patients with metastatic melanoma: a prognostic model

We aimed to create a prognostic model in metastatic melanoma based on independent prognostic factors in 321 patients receiving interleukin-2 (IL-2)-based immunotherapy with a median follow-up time for patients currently alive of 52 months (range 15–189 months). The patients were treated as part of several phase II protocols and the majority received treatment with intermediate dose subcutaneous IL-2 and interferon-α. Neutrophil and monocyte counts, lactate dehydrogenase (LDH), number of metastatic sites, location of metastases and performance status were all statistically significant prognostic factors in univariate analyses. Subsequently, a multivariate Cox's regression analysis identified elevated LDH (P<0.001, hazard ratio 2.8), elevated neutrophil counts (P=0.02, hazard ratio 1.4) and a performance status of 2 (P=0.008, hazard ratio 1.6) as independent prognostic factors for poor survival. An elevated monocyte count could replace an elevated neutrophil count. Patients were assigned to one of three risk groups according to the cumulative risk defined as the sum of simplified risk scores of the three independent prognostic factors. Low-, intermediate- and high-risk patients achieved a median survival of 12.6 months (95% confidence interval (CI), 11.4–13.8), 6.0 months (95% CI, 4.8–7.2) and 3.4 months (95% CI, 1.2–5.6), respectively. The low-risk group encompassed the majority of long-term survivors, whereas the patients in the high-risk group with a very poor prognosis should probably not be offered IL-2-based immunotherapy

Designing and Building a Buried High Integrity Pipeline for 150°C Emulsion Transportation

Abstract This SAGD development is a tie-back extension to an existing upgrader. Two parallel pipelines ship water and emulsion between the two facilities: water is piped from the upgrader to the SAGD wellpads at 130°C where it is heated through OTSGs before injection into the wells and a water/bitumen emulsion is then retrieved from the wells, to be piped back to the upgrader at 150°C where the bitumen is separated out. The terrain between the two facilities is difficult with ca. 60% muskeg and several creeks, railroads and highways that require HDDs (Horizontal Direction Drill). Given the high design temperatures and the mostly non-competent soil, an electrically traced ITP pipe-in-pipe was selected as the most robust solution. The following advantages in operation, construction and for integrity surveillance were identified by the operator: Extremely efficient thermal insulationUnlimited shutdown capabilitySelf-anchoring of the inner pipe to the outer pipe, reducing reliance on soil propertiesSimple pre-tensioning using the heat-tracing systemReduced thermal expansion, eliminating expansion loopsNegative buoyancy, eliminating the need for anchoring the pipelineHigh integrity of the jacket pipe with ○Leak before spill detection capability○Second-to-none leak detection sensitivity (x1000 relative to volumetric methods) A key learning of construction during the winter of 2013 was that up to 1 km per day could be built. The presentation will detail the system key elements, the rationale for its design and provide the lessons learned from the wintertime installation in a typical northern Alberta SAGD development, and in particular how the electrical heat tracing provides schedule control for the pre-tensioning. The technology has the potential to significantly change the operation of oil/bitumen fields by eliminating the requirement for diluent. The heat tracing technology combined with an extremely efficient insulation allows transport of the hot fluids over unlimited distances. In the wider picture, the pipe-in-pipe technology provides a means to achieve an extremely sensitive pipeline integrity surveillance with almost instantaneous detection of all but the smallest leaks (which will be detected eventually); it could be proposed as a reliable solution for difficult areas where enhanced scrutiny is deemed necessary, such as wetlands, HDDs, unstable terrain etc., at an installed cost that is not significantly higher than for a simple pipeline. During the winter of 2012-2013, a first application of an Electrically Heat Traced Flowline (EHTF) based on pipe-in-pipe (PIP) technology was installed in the Fort McMurray area. It consists of two buried high-temperature lines to be operated by a major Canadian Oil&amp;Gas Company at design temperatures of respectively 110°C and 150°C. This technology has been selected by the operator because of advantages inherent to the technology and the project execution has demonstrated that this novel solution is compatible with the severe weather conditions and areas of northern Alberta. Moreover, careful planning and use of the heat tracing capability of the pipelines provides simple schedule control of the required pre-stressing of the pipelines prior to burial. The technology has the potential to significantly change the operation of oil/bitumen fields by eliminating the requirement for diluent and providing a means of tying satellite developments back to existing facilities. The heat tracing technology combined with an extremely efficient insulation actually allows transport of the hot fluids over unlimited distances. From an integrity and environmental perspective, the pipe-in-pipe technology provides a means to achieve extremely sensitive pipeline integrity surveillance with almost instantaneous detection of all but the smallest leaks (which will be detected eventually); it could even be proposed as a safety feature on non-thermal pipelines for difficult areas where enhanced scrutiny is deemed necessary, such as wetlands, HDDs, unstable terrain etc., at an installed cost that is not significantly higher than for a simple pipeline. The articles details the system key elements, the rationale for its design and provide the lessons learned from the wintertime installation in a typical northern Alberta SAGD development, and in particular how the electrical heat tracing provides a simple means of controlling pre-tensioning.</jats:p