Academic literature on the topic 'Jorgensen'

Inspired by Jorgensen et al., it is proved that if a Cohen-Macaulay local ring $R$ with dualizing module admits a suitable chain of semidualizing $R$-modules of length $n$, then $R\cong Q/(I_1+\cdots +I_n)$ for some Gorenstein ring $Q$ and ideals $I_1,\dots , I_n$ of $Q$; and, for each $\Lambda \subseteq [n]$, the ring $Q/(\sum _{\ell \in \Lambda } I_\ell )$ has some interesting cohomological properties. This extends the result of Jorgensen et al., and also of Foxby and Reiten.

En el presente trabajo sostenemos que si bien desde un sistema lógico hasta ahora no se ha logrado mostrar la existencia de una semántica de los enunciados imperativos, sin embargo sí demostramos que el problema que representa uno de los cuernos del dilema de Jørgensen no tiene la misma fuerza que cuando se planteó. Es así que enunciados de tipo “¡Juan, haz tus deberes!”, si bien no tienen un valor de verdad, esto no quiere decir que no tenga otro valor semántico, como el de justicia, por ejemplo. Para efectos del presente trabajo, nos restringiremos a una semántica bivalente justo/injusto, pues consideramos que si demostramos que dicha semántica le corresponde a los imperativos, recién cabe plantearse el estudio de una semántica polivalente de los imperativos. Por otro lado, metodológicamente, el presente trabajo se inserta dentro de la filosofía matemática. Cabe señalar que tal denominación no hace referencia a la filosofía de las matemáticas en absoluto, sino el mismo hace referencia al método de estudio de la filosofía. Así, la filosofía matemática es la investigación filosófica de un tema haciendo uso de herramientas formales (lógica y matemáticas). Esta forma de investigación es la que se realiza en el Munich Center for Mathematical Philosophy – MCMP (ver: http://www.mcmp.philosophie.uni-muenchen.de/index.html). Y que en nuestro país se hace en el Taller de Filosofía Matemática que funciona en la Facultad de Matemáticas de la Universidad Nacional Mayor de San Marcos, al cual pertenecemos. Al presente trabajo, le hemos agregado un vocabulario esencial de los términos más empleados en el curso de nuestra investigación y dos apéndices, que indican el contexto mayor dentro del cual se ubica la presente investigación. Ambos apéndices pueden ser vistos como los problemas que están pendientes de ser resueltos si se quiere contar con una auténtica y adecuada lógica de imperativos.
Tesis

Harsh realities exist in the South African Police Service (SAPS) that require concepts such as burnout and work engagement to be studied in the context of work-related well-being. Although these difficulties relate to police officials experiencing work-related trauma, more stressors seem to manifest on an organisational level, which in turn affects the psychological well-being of police officials. This study seeks to focus on the burnout and engagement of members of the Local Criminal and Record Centre (LCRC) in the SAPS. The members of the LCRC are exposed to severe occupational stressors relating to their job content, which necessitates research in occupational stress relating to the health of SAPS members. For the purposes of this study, the model of occupational stress, commitment and ill health of Cartwright and Cooper (2002) will be utilised to explain strain and organisational commitment. Work-related well-being, on the other hand, can best be explained by referring to the model of well-being developed by Schaufeli and Bakker (200 1 ). Since job demands play a central role in burnout, it is necessary to implement preventive organisationally-based strategies to address high job demands. Upon reviewing stress research, it became clear that a serious lack of intervention research exists. Little information is available about the work-related well-being of SAPS members, whilst no documented research could be found regarding the effects of an intervention programme on the work-related well-being of LCRC members. The study aimed at utilising three levels of intervention (primary, secondary and tertiary) on organisational and individual level. An integrated classification scheme of both the positive and negative aspects of work-related well-being on the organisational and individual level was developed and presented to members from the LCRC over a one-year period. The research method for each of the three articles of this study consisted of a brief literature review and an empirical study. An availability non-randomised sample was selected because the entire in-tact group of the LCRC of the SAPS (N=111) in the North West Province was included in the study. A survey design was used to achieve the research objectives of both Articles 1 and 2, whilst a longitudinal survey design was utilised in Article 3, where the same instruments were administered at two different times (over a one-year period) to the same group of participants. The measuring instruments used in this study are the Maslach Burnout Inventory-General Survey (MBI-GS), Utrecht Work Engagement Scale (UWES), Job Demands-Resources Scale (JDRS), Health subscales, Organisational Commitment subscales, the ASSET questionnaire and a biographical questionnaire. Structural equation modelling was implemented to test a structural model of work-related wellbeing. A good fit was found for the model in which perceived job demands contributed to burnout which, in turn, impacted on ill health. Work wellness was determined by the relationship between two opposite constructs, namely burnout and engagement. The work-related well-being of members of the LCRC was affected by an environment of high job demands and inadequate resources. In Article 2, multiple regression analyses showed that occupational stress explained 19% of the variance in psychological ill health and 17% of the variance in physical ill health. A two-step multiple regression analysis conducted with the variables in their continuous form revealed that control was a statistically significant predictor of both physical and psychological ill health, while job overload statistically significantly predicted psychological ill health. Occupational stress also explained 17% of the variance in individual commitment and 16% of the variance in organisational commitment. It was concluded that individual commitment moderated the effects of stressful work relations on ill health. LCRC members portrayed a high risk to fall ill due to exhaustion; they were less enthusiastic about their job and tended to derive a lower sense of significance from their work. In addition, members showed a major risk for developing low affective commitment due to low work engagement. Exhaustion influenced the way members view their job demands, organisational and social support, as well as growth opportunities available to them. A lack of advancement opportunities and job insecurity contributed to feelings of exhaustion and cynicism. Another objective of this study was to evaluate interventions used to promote work-related wellbeing of LCRC members. Although no significant differences were found between the pre- and post-measurements, some positive aspects did flow from the interventions. For instance an active effort by management to address resource needs. Recommendations for future research were made.
Thesis (Ph.D. (Industrial Psychology))--North-West University, Potchefstroom Campus, 2007.

In this thesis, electron paramagnetic resonance (EPR) was utilized in measuring and characterizing the dopant ions in three samples of lithium niobate (LiNbO₃). The first sample was LiNbO₃ of congruent composition doped with 0.25% mol chromium (LiNbO₃:Cr). This sample was studied in detail using two microwave frequencies, 9.4 GHz and 34.4 GHz. It was also studied both at room temperature and at 10 K. Several centers including complexes of Cr-Cr pairs were observed in addition to the most prevalent axial Cr³⁺ center. The other two samples were LiNbO₃:Mg:Fe, one of congruent composition and the other of stoichiometric composition. The congruent composition contained 6% mol Mg and 0.02% mol Fe, while the stoichiometric sample contained 0.45% mol Mg and 0.01% mol Fe. The stoichiometric composition contains all the same centers observed in the congruent material, plus two additional centers. Since the stoichiometric material provides EPR spectra of much higher resolution, those centers existing in both compositions were characterized more accurately from the stoichiometric material. A discussion of models for dopant center symmetries, dopant positions in the LiNbO₃ lattice, and the charge compensators required by each center is provided. It is shown that charge compensators play an important role in explaining the existence of the additional centers observed in the stoichiometric material.

Christine Jorgensen is the first known American citizen undergo sexual reassignment surgery. After her medical operations in Denmark in 1952, during which George Jorgensen Jr., a twenty-six year old man from the Bronx, New York, became Christine Jorgensen, an attractive, feminine woman, Jorgensen returned home to face the curiosity and scrutiny of the American public. As the “first celebrity transsexual," Jorgensen sparked public controversy by questioning the gender expectations that structured society in mid-twentieth century America. Jorgensen’s gender presentation closely aligned to the idealized standards of womanhood reinforced by institutional forces during the 1950s. Due to the amount of public scrutiny she faced after her transition, Jorgensen had to conform to these expectations entirely in order to achieve social acceptance. Examining Jorgensen’s gender expression critically exposes the social limits for expression of gender as well as what forces were responsible for placing these limits on women.

Cette thèse s’inscrit dans le cadre de la thématique du Laboratoire de Pharmacognosie de l’UFR des Sciences de santé, au sein de l’Université de Bourgogne Franche-Comté et du Laboratoire de Produits Naturels de la Faculté de Sciences, au sein de l’Universidad Central de Venezuela. Elle vise essentiellement l’étude phytochimique des graines de Billia rosea (Planch. & Linden) C. Ulloa & P. Jørg, famille des Sapindaceae, qui est utilisé en médecine traditionnelle comme antidiabétique, analgésique et pour le traitement des hémorroïdes et de la fièvre. L'étude de cette espèce végétale a conduit à l’isolement et à la caractérisation de 10 saponines triterpéniques parmi lesquelles 5 sont de structure nouvelle (Billiosides A–E), un analogue connu et une structure a été proposée pour les 4 autres saponines qui devraient être vérifiées dans des études ultérieures.Les structures ont été élucidées principalement par l’utilisation de RMN 1D et 2D (1H, 13C, DEPT, COSY, TOCSY, NOESY, ROESY, HSQC, et HMBC) ainsi que la spectrométrie de masse comme (3β,21β,22α)-3-[(2-O-β-D-glucopyranosyl-O-[α-L-arabinopyranosyl-(1 / 4)]-β-D-glucopyranosyl)oxy]-21-[((2E,6S)-2,6-dimethyl-6-hydroxyocta-2,7-dienoyl)oxy]-22-(acetyloxy)-24-hydroxyolean-12-en-28-oic acid (Billioside A), (3β,21β,22α)-3-[(2-O-β-D-galactopyranosyl-β-D-glucopyranosyl)oxy]-21,22-dihydroxyolean-12-en-28-yl O-α-L-arabinopyranosyl-(1 → 4)-β-D-glucopyranoside (Billioside B), (3β,21β,22α)-3-[(2-O-β-D-galactopyranosyl-O-[α-L-arabinopyranosyl-(1 → 4)]-β-D-xylopyranosyl)oxy]-21,22-dihydroxyolean-12-en-28-yl O-β-D-glucopyranoside (Billioside C), (3β,21β,22α)-3-[(2-O-β-D-galactopyranosyl-O-[α-L-arabinopyranosyl-(1 → 4)]-β-D-glucopyranosyl)oxy]-21,22-dihydroxyolean-12-en-28-yl O-β-Dglucopyranoside (Billioside D), (3β,21β,22α)-3-[(2-O-β-D-galactopyranosyl-O-[α-L-arabinopyranosyl-(1 → 4)]-β-Dglucopyranosyl)oxy]-21,22-dihydroxyolean-12-en-28-yl O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranoside (Billioside E), et dipteroside A.Les structures proposées pour les 4 autres saponines sont (3β,16α,21β,22α)-3-[(4-O-α-L-arabinopyranosyl-β-D-glucuronopyranosyl)oxi]-22-(acetyloxy)-16,24,28-trihidroxyolean-12-en-21-yl-O-(3,4-di-O-angeloyl)-6-Deoxy-β-D-glucopyranoside, es (3β,16α,21β,22α)-3-[(4-O-α-L- glucuronopyranosyl -β-D-glucuronopyranosyl)oxy]- 16,22,24,28-tetrahidroxyolean-12-en-21-yl-O-(3,4-di-O-angeloyl)-6-Deoxy-β-D-glucopyranoside, (3β,16α,21β,22α)-3-[(2-O- β-D-galactopyranosyl-β-D-glucuronopyranosyl)oxy]-22-(acetyloxy)-16,24,28-trihidroxyolean-12-en-21-yl-O-(3,4-di-O-angeloyl)-6-Deoxy-β-D-glucopyranoside et (3β,21β,22α)-3-[(2-O-β-D-galactopyranosyl-O-[α-L-arabinopyranosyl-(1→4)]-β-D-xylopyranosyl)oxy]-21-acetyl-22-hidroxyolean-12-en-28-yl-O-α-L-arabinopyranosyl-(1→4)-β-D-glucopyranoside.Billiosides B et C ont été testés en vue d’évaluer leurs capacité à inhiber l'absorption intestinale du glucose in situ dans des segments d'intestins de rat, et sa capacité à inhiber le glucose-6-phosphatase, enzyme impliquée dans la formation du glucose. Billiosides B et C ont montré des effets modérés dans les deux expériences
This thesis was carried out in the the Laboratory of Pharmacognosy, in health department of the University of Burgundy and in the Laboratory of Natural products of Central University of Venezuela.This research work focused on the phytochemical study of the sedes of Billia rosea (Planch. & Linden) C. Ulloa & P. Jørg, Sapindaceae family. Billia rosea seeds have traditionally been used as antidiabetic, analgesic and for the treatment of hemorrhoids and fever. In the study of this plant was isolated and characterized 10 triterpene saponins, among which 5 has a new structure in the literature of natural products (Billiosides A–E), a known analogue and 4 proposals as possible structures to the remaining isolated saponins, which must be confirmed in subsequent studies.Their structures were elucidated on the basis of extensive 1D and 2D NMR experiments (1H, 13C, DEPT, COSY, TOCSY, NOESY, ROESY, HSQC, et HMBC) and mass spectrometry as (3β,21β,22α)-3-[(2-O-β-D-glucopyranosyl-O-[α-L-arabinopyranosyl-(1 / 4)]-β-D-glucopyranosyl)oxy]-21-[((2E,6S)-2,6-dimethyl-6-hydroxyocta-2,7-dienoyl)oxy]-22-(acetyloxy)-24-hydroxyolean-12-en-28-oic acid (Billioside A), (3β,21β,22α)-3-[(2-O-β-D-galactopyranosyl-β-D-glucopyranosyl)oxy]-21,22-dihydroxyolean-12-en-28-yl O-α-L-arabinopyranosyl-(1 → 4)-β-D-glucopyranoside (Billioside B), (3β,21β,22α)-3-[(2-O-β-D-galactopyranosyl-O-[α-L-arabinopyranosyl-(1 → 4)]-β-D-xylopyranosyl)oxy]-21,22-dihydroxyolean-12-en-28-yl O-β-D-glucopyranoside (Billioside C), (3β,21β,22α)-3-[(2-O-β-D-galactopyranosyl-O-[α-L-arabinopyranosyl-(1 → 4)]-β-D-glucopyranosyl)oxy]-21,22-dihydroxyolean-12-en-28-yl O-β-Dglucopyranoside (Billioside D), (3β,21β,22α)-3-[(2-O-β-D-galactopyranosyl-O-[α-L-arabinopyranosyl-(1 → 4)]-β-Dglucopyranosyl)oxy]-21,22-dihydroxyolean-12-en-28-yl O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranoside (Billioside E), and dipteroside A.The proposed structures for the other 4 isolated saponins are (3β,16α,21β,22α)-3-[(4-O-α-L-arabinopyranosyl-β-D-glucuronopyranosyl)oxi]-22-(acetyloxy)-16,24,28-trihidroxyolean-12-en-21-yl-O-(3,4-di-O-angeloyl)-6-Deoxy-β-D-glucopyranoside, es (3β,16α,21β,22α)-3-[(4-O-α-L- glucuronopyranosyl -β-D-glucuronopyranosyl)oxy]- 16,22,24,28-tetrahidroxyolean-12-en-21-yl-O-(3,4-di-O-angeloyl)-6-Deoxy-β-D-glucopyranoside, (3β,16α,21β,22α)-3-[(2-O- β-D-galactopyranosyl-β-D-glucuronopyranosyl)oxy]-22-(acetyloxy)-16,24,28-trihidroxyolean-12-en-21-yl-O-(3,4-di-O-angeloyl)-6-Deoxy-β-D-glucopyranoside and (3β,21β,22α)-3-[(2-O-β-D-galactopyranosyl-O-[α-L-arabinopyranosyl-(1→4)]-β-D-xylopyranosyl)oxy]-21-acetyl-22-hidroxyolean-12-en-28-yl-O-α-L-arabinopyranosyl-(1→4)-β-D-glucopyranoside.Billiosides B and C exhibited moderate effects when tested as hepatic glucose-6-phosphatase inhibitors and as glucose intestinal absorption inhibitors, using in situ rat intestinal segments
Este trabajo de investigación, realizado en conjunto entre el Laboratorio de Farmacognosia de la Facultad de Ciencias de la Salud, de la Université de Bourgogne Franche-Comté y el Laboratorio de Productos Naturales de la Facultad de Ciencias de la Universidad Central de Venezuela; se centró en el estudio fitoquímico de las semillas de Billia rosea (Planch. & Linden) C. Ulloa & P. Jørg, perteneciente a la familia Sapindaceae, utilizada tradicionalmente como antidiabético, analgésico y para el tratamiento de hemorroides y fiebre. El estudio de esta especie vegetal condujo al aislamiento y caracterización de 9 saponinas triterpénicas, entre las cuales 5 poseen una estreuctura nueva en la literatura de productos naturales (Billiosidos A–E), un análogo conocido, además de 3 propuestas como posibles estructuras a las restantes saponinas aisladas, que deben ser confirmadas en estudios posteriores. Las estructuras se elucidaros principalmente mediante el uso de RMN 1D y 2D (1H, 13C, DEPT, COSY, TOCSY, NOESY, ROESY, HSQC, et HMBC) y espectrometría de masa como ácido (3β,21β,22α)-3-[(2-O-β-D-glucopiranosil-O-[α-L-arabinopiranosil-(1→4)]-β-D-glucopiranosil)oxi]-21-[((2E,6S)-2,6-dimetil-6-hidroxiocta-2,7-dienoil)oxi]-22-(acetiloxi)-24-hidroxiolean-12-en-28-oico, (Billiosido A) (3β,21β,22α)-3-[(2-O-β-D-galactopiranosil-β-D-glucopiranosil)oxi]-21,22-dihidroxiolean-12-en-28-il-O-α-L-arabinopiranosil-(1 → 4)-β-D-glucopiranosido (Billiosido B), (3β,21β,22α)-3-[(2-O-β-D-galactopiranosil-O-[α-L-arabinopiranosil-(1→4)]-β-D-xilopiranosil)oxi]-21,22-dihidroxiolean-12-en-28-il-O-β-D-glucopiranosido (Billiosido C), (3β,21β,22α)-3-[(2-O-β-D-galactopiranosil-O-[α-L-arabinopiranosil-(1 → 4)]-β-D-glucopiranosil) oxi]-21,22-dihidroxiolean-12-en-28-yl-O-β-D-glucopiranosido (Billiosido D), (3β,21β,22α)-3-[(2-O-β-D-galactopiranosil-O-[α-L-arabinopiranosil-(1→4)]-β-D-glucopiranosil)oxi]-21,22-dihidroxiolean-12-en-28-il-O-β-D-glucopiranosil-(1→6)-β-D-glucopiranosido (Billiosido E) y Dipterosido A. Las estructuras propuestas para las otras 3 saponinas aisladas son (3β,16α,21β,22α)-3-[(4-O-α-L-arabinopiranosil-β-D-glucoronopiranosil)oxi]-22-(acetiloxi)-16,24,28-trihidroxiolean-12-en-21-il-O-(3,4-di-O-angeloil)-6-Deoxy-β-D-glucopiranosido, (3β,16α,21β,22α)-3-[(4-O-β-D-galactopiranosil-β-D-glucoronopiranosil)oxi]-22-(acetiloxi)-16,24,28-trihidroxiolean-12-en-21-il-O-(3,4-di-O-angeloil)-6-Deoxy-β-D-glucopiranosido y (3β,21β,22α)-3-[(2-O-β-D-galactopiranosil-O-[α-L-arabinopiranosil-(1→4)]-β-D-xilopiranosil)oxi]-21-acetil-22-hidroxiolean-12-en-28-il-O-α-L-arabinopiranosil-(1→4)-β-D-glucopiranosido. También se evaluó la actividad inhibitoria de los Billiosidos B y C sobre la absorción intestinal de glucosa in situ en segmentos de intestinos de ratas, además de la capacidad inhibitoria de estos compuestos sobre la enzima glucosa-6-fosfatasa, implicada en la formación de glucosa. Estos Billiosidos mostraron efectos moderados en estos dos experimentos

ZusammenfassungDie Krise der Eurozone hat es gezeigt: Die Tragbarkeit der Staatsschulden ist begrenzt. Jedoch ist kaum etwas so unsicher wie die Erwartungen über die künftige Fiskalpolitik eines Landes und so schwierig wie die Einschätzung der staatlichen Kreditwürdigkeit. Die Risikoeinschätzungen der Marktteilnehmer schwanken zwischen Vertrauen, harten Daten und Angst. Geht das Vertrauen verloren und breiten sich Misstrauen und Angst aus, dann setzt eine unkoordinierte Kapitalflucht ein. Sie lässt die Zinsen schlagartig ansteigen, verschärft die Krise erst recht und kann im schlimmsten Fall eine Insolvenz herbeizwingen. Kann die Zentralbank mit ihrer Geldpolitik die Marktängste zerstreuen und eine prekäre Lage stabilisieren?Krishnamurthy, Arvind, Stefan Nagel und Annette Vissing-Jorgensen (2018), ECB Policies Involving Government Bond Purchases: Impact and Channels, Review of Finance 22, 1–44.

Chapter 4 situates the ascendance of Christine Jorgensen, dubbed America’s first transsexual celebrity, alongside myriad projects of U.S. imperial conquest and various forms of violent racist suppression at home. Focusing on the media narratives of Lucy Hicks Anderson, Georgia Black, Carlett Brown, James McHarris/Annie Lee Grant, and Ava Betty Brown that emerged in the black press, this chapter offers other ways to narrate trans embodiment in the postwar, early Cold War period.

The ruins of modernity are inevitably the ruins of the North. Actual or imagined ruined cities (the real Detroit or a post-apocalyptic London) are always Euro-American industrial or post-industrial metropolises (Vergara 1999; Woodward 2002; Edensor 2005; Jorgensen and Keenan 2012). These ruins are receiving growing attention by researchers, who often see them as metaphors of a diverse kind—including of our cultural anxieties and fears, of colonialism, capitalism, of the end of master narratives (Hell and Schönle 2010; Dillon 2011; Stoler 2013). They are also scrutinized by cultural heritage managers and politicians who try to transform them into spaces of memory, of leisure and consumption, or both. The post-industrial ruins of the South have received much less attention in recent debates on ruination, decay, recovery, and gentrification, although there are a few significant exceptions, most notably the work of Gordillo (2009, 2014) in Argentina and also Rodríguez Torrent et al. (2011, 2012) and Vilches (et al. 2008, 2011) in Chile. This is due to several reasons: one of them is the fact that southern urbanization and industrialization are usually perceived as a recent process. They are too young to have generated ruins: after all, none of the diverse southern ‘miracles’ of which economists speak (South-east Asian, Brazilian, African, and so on) dates from before the 1960s. It is well known that when companies do outsourcing, it is the so-called emerging economies that benefit from it: new factories for the South, new ruins for the North. Another reason is that the long-term process of modernity is still very much associated with Euro-American history. The rest of the globe is seen as having a later, incomplete, or surrogate modernity, as post-colonial historians have abundantly criticized (Chakrabarty 2000). In addition, the cultural and political conditions of the North have enabled the emergence of popular engagements with ruins, such as urban exploring or video games, that have made their processes of metropolitan ruination more conspicuous at a global level (Garrett 2013; Pétursdóttir and Olsen 2014: 4).

În studiul de față ne vom referi la experiența de emigrant a românilor din Est reflectată în romanul „Clownul din lemn de gutui” de Radu Jorgensen și în piesele de teatru „Avant de mourir” de Val Butnaru, „În container” de Constantin Cheianu și „Oameni ai nimănui” de Dumitru Crudu. Textele se bazează pe fapte reale și constituie o radiografiere a celor mai dramatice crize cu care se confruntă emigrantul azi convertite în ficțiune. Autorii nu urmăresc să-și impresioneze cititorii cu strategii discursive sau didascalii deosebite. Ei încearcă să-i atragă și să-i sensibilizeze prin fabulă și mesaj. Impresia de autenticitate în textele menționate este sporită de multitudinea detaliilor și de marcanta tensiune a mărturisirii.

Abstract The utility of a model-based recurrent neural network (MBRNN) is demonstrated in fault diagnosis. The MBRNN can be formatted according to a state-space model. Therefore, it can use model-based fault detection and isolation (FDI) solutions as a starting point, and improve them via training by adapting them to plant nonlinearities. In this paper, the application of MBRNN to the IFAC Benchmark Problem is explored and its performance is compared with ‘black box’ neural network solutions. For this problem, the MBRNN is formulated according to the Eigen-Structure Assignment (ESA) residual generator developed by Jorgensen et al. [1]. The results indicate that the MBRNN provides better results than ‘black box’ neural networks, and that with training it can perform better than the ESA residual generator.

Classical hydrodynamic force estimation methods are widely used by industrial designers of underwater vehicles for whom captive model experiments and CFD based simulations are uneconomical. They are also used in the preliminary design of submarines and when real time submarine simulations are required. These methods poorly estimate the contribution of the hull to the forces, especially at moderate to high incidence angles. This paper critically reviews the classical hull force estimation methods developed by Munk, Allen, Perkins and Jorgensen, and Sarpkaya. It compares the methods with experimentally validated CFD predictions of a streamlined body at incidence angles up to 30 degrees and for Reynolds numbers from 2.3 to 230 million. The comparison shows that inadequately modeled flow separation and leeside body vortices explain the poor force and moment predictions. This is partly due, at least, to the lack of a streamlined tail on the truncated missile shapes for which the estimation methods were developed.

Abstract It is now widely recognized that destabilizing forces, tending to generate forward rotor whirl, are generated in axial flow turbines as a result of the non-uniform torque induced by the non-uniform tip-clearance in a deflected rotor — the so called Thomas/Alford force (Thomas, 1958 and Alford, 1965). It is also recognized that there will be a similar effect in axial flow compressors, but qualitative considerations cannot definitively establish the magnitude or even the direction of the induced whirling forces — that is, if they will tend to forward or backward whirl. Applying a “parallel compressor” model to simulate the operation of a compressor rotor deflected radially in its clearance, it is possible to derive a quantitative estimate of the proportionality factor β which relates the Thomas/Alford force in axial flow compressors (i.e., the tangential force generated by a radial deflection of the rotor) to the torque level in the compressor. The analysis makes use of experimental data from the GE Aircraft Engines Low Speed Research Compressor facility comparing the performance of three different axial flow compressors, each with four stages (typical of a mid-block of an aircraft gas turbine compressor) at two different clearances (expressed as a percent of blade length) — CL/L = 1.4% and CL/L = 2.8%. It is found that the value of β is in the range of +0.27 to −0.71 in the vicinity of the stages’ nominal operating line and +0.08 to −1.25 in the vicinity of the stages’ operation at peak efficiency. The value of β reaches a level of between −1.16 and −3.36 as the compressor is operated near its stalled condition. The final result bears a very strong resemblance to the correlation obtained by improvising a normalization of the experimental data of Vance and Laudadio (1984) and a generic relationship to the analytic results of Colding-Jorgensen (1990).