226 research outputs found
Polyethylene acetabular liner rim damage in total hip replacements
No full textTotal hip replacement surgery is a successful orthopaedic intervention with over
90,000 procedures carried out annually; however, some implants still fail. The failure of
THRs in the first year have been related to mechanical failure, such as dislocation and/or
implant fracture. The mechanical failure of polyethylene liners has been mainly
associated with damage at the rim of liners, due to edge loading and/or impingement.
Implant failure typically leads to the revision of the implant, which is more costly and
predominately less successful for the patient; therefore, the occurrence and
consequence of impingement and dislocation are required to be understood to reduce
mechanical failure of future THRs. The aim of this project was to investigate and
characterise rim damage of polyethylene liners of THRs.
To understand the occurrence of impingement, a geometric model was
developed that incorporated THR components into a bone model and investigated
impingement during different dislocation-prone activities. The model was applied to
investigate the effect that varying the surgical positioning of the acetabular component
and the component design has on the likelihood of impingement. In terms of the
positioning of the acetabular component, increasing the inclination and anteversion of
the acetabular cup reduced the risk of impingement. Varying the design of the liner from
a neutral to a lipped liner caused more frequent impingement, and reducing the neckshaft
angle reduced the frequency of impingement.
To understand what rim damage is caused by impingement, methods were
developed to quantitatively assess rim damage of polyethylene liners and to
experimentally replicate clinically relevant rim damage due to impingement. The method
applied motion and load inputs to simulate a clinically relevant activity, and was applied
to investigate the effect of varying the severity of impingement and medial-lateral load
has on the severity of damage. Increasing the severity of impingement was found to
increase the severity of rim damage and the amount of separation of the head.
To check the clinical relevance of the results from the developed geometric model
and the experimental method, a series of retrieved polyethylene liners of the same
design were reviewed; damage was visually assessed, rim damage quantified, and invivo
orientation of components were measured.
Overall the series of developed methods have been used to assess and
characterise rim damage of polyethylene liners, and the methods have the potential to
assist with the pre-operative planning of THR surgeries, pre-caution post THR surgery
and aid with the design process of future designs of implants
Author Correction: Environmental variability supports chimpanzee behavioural diversity
No full textThe original version of the Supplementary Information associated with this Article included an incorrect Supplementary Data 1 file, in which three columns (L, M and P) had slightly different variable names from those written in the code. The HTML has been updated to include a corrected version of Supplementary Data 1; the correct version of Supplementary Data 1 can be found as Supplementary Information associated with this Correction.Additional co-authors: Mattia Bessone, Gregory Brazzola, Valentine Ebua Buh, Rebecca Chancellor, Heather Cohen, Charlotte Coupland, Bryan Curran, Emmanuel Danquah, Tobias Deschner, Dervla Dowd, Manasseh Eno-Nku, J. Michael Fay, Annemarie Goedmakers, Anne-Céline Granjon, Josephine Head, Daniela Hedwig, Veerle Hermans, Sorrel Jones, Jessica Junker, Parag Kadam, Mohamed Kambi, Ivonne Kienast, Deo Kujirakwinja, Kevin E. Langergraber, Juan Lapuente, Bradley Larson, Kevin C. Lee, Vera Leinert, Manuel Llana, Sergio Marrocoli, Amelia C. Meier, David Morgan, Emily Neil, Sonia Nicholl, Emmanuelle Normand, Lucy Jayne Ormsby, Liliana Pacheco, Alex Piel, Jodie Preece, Martha M. Robbins, Aaron Rundus, Crickette Sanz, Volker Sommer, Fiona Stewart, Nikki Tagg, Claudio Tennie, Virginie Vergnes, Adam Welsh, Erin G. Wessling, Jacob Willie, Roman M. Wittig, Yisa Ginath Yuh, Klaus Zuberbühler & Hjalmar S. Küh
The transformation of corporate organization in Europe: An overview
No full textVery large firms, the rising significance of small and medium-sized enterprises notwithstanding, still account for most of the employment and wealth creation in Europe and will continue to do so for the foreseeable future. They also to a large extent determine the political institutions that regulate the relationship between economy and society, in particular the status of workers and the way in which the public interest is brought to bear on the economy. This overview on the current transformation of corporate organization in Europe begins by asking whether there is in fact a European model of the large firm, despite the considerable differences that exist between European countries, and to what extent European integration is likely to bring about convergence on a more uniform pattern. Next, it reviews the changes in the organization of large European firms and in corporate governance in Europe during the 1990s, which took place in response to the evolution of two of the major task environments of firms, product markets and financial markets. Third, the paper discusses the consequences of corporate transformation for the social embeddedness of large European firms, especially the challenges posed by the ongoing changes in corporate organization to European systems of industrial citizenship of workers and to the capacity of European states and governments to hold large firms socially accountable. In conclusion, the paper emphasizes the growing autonomy of large firms as strategic actors and comments on the problems of corporate adjustment under high and endemic uncertainty. -- Trotz der steigenden Bedeutung von kleinen und mittleren Unternehmen sind Großunternehmen weiterhin die wichtigste Quelle von Beschäftigung und Wohlstand in Europa. Dies wird sich in absehbarer Zukunft nicht ändern. Großunternehmen haben auch erheblichen Einfluss auf die politischen Institutionen, die das Verhältnis zwischen Wirtschaft und Gesellschaft regeln, vor allem den Status von Arbeitnehmern und die Art und Weise, wie öffentliche Interessen gegenüber der Wirtschaft zur Geltung gebracht werden. Ausgangspunkt der Überlegungen des Papiers über die gegenwärtigen Veränderungen in der Organisation europäischer Großunternehmen ist die Frage, ob es ungeachtet beträchtlicher nationaler Unterschiede ein europäisches Modell der Unternehmensorganisation gibt bzw. inwieweit die europäische Integration zu einer Konvergenz auf ein einheitlicheres System führen wird. Das Papier beschreibt die während der Neunzigerjahre eingetretenen Veränderungen in der Organisation großer europäischer Unternehmen und in den nationalen Systemen der Corporate Governance und erklärt diese als Antwort auf den Wandel der beiden entscheidenden Unternehmensumwelten, der Produkt- und Finanzmärkte. Anschließend werden die Auswirkungen des Strukturwandels der großen Unternehmen auf deren soziale Einbettung diskutiert, und zwar insbesondere die von ihm ausgehenden Herausforderungen für die nationalen Systeme industrieller Bürgerrechte sowie die Fähigkeit europäischer Staaten und Regierungen, gegenüber großen Unternehmen auf deren gesellschaftlichen Verpflichtungen zu bestehen. In der Schlussbetrachtung wird die wachsende Autonomie großer Unternehmen als strategische Akteure hervorgehoben und die Problematik der Anpassung von Corporate Governance-Systemen unter Bedingungen großer und endemischer Unsicherheit diskutiert.
Episode 34: Black Hawk Down (2001) (Guest: Gregory Fox)
No full textBlack Hawk Down (2001) describes the plight of the U.S. crew of a Black Hawk helicopter that is shot down during the Battle of Mogadishu during the civil war in Somalia in October 1993. The battle resulted in the death of 18 American soldiers and hundreds of Somalis; it also prompted the U.S. withdrawal from Somalia after images of dead U.S. soldiers being dragged through the streets of Mogadishu by enraged Somalis were broadcast on American television. Directed by Ridley Scott from a book by Mark Bowden, Black Hawk Down is a gritty action movie that captures the brutal nature of urban warfare. It also provides a window into a host of complex international legal and political issues as well as the opportunities–and challenges–for humanitarian intervention in the aftermath of the Cold War.
Guest: Gregory Fox
Greg Fox is Professor of law and Director of the Program for International Legal Studies at Wayne State University Law School. Professor Fox is a widely cited authority on international law and international organizations and a leader in a variety of academic and professional organizations. Professor Fox began his legal career in the litigation department of Hale & Dorr (now WilmerHale) in Boston, where he worked on one of the early cases brought under the Alien Tort Statute, Forti v. Suarez-Mason. He held fellowships at the Max Planck Institute for Comparative Public Law and Public International Law in Heidelberg, Germany, and at the Schell Center for Human Rights at Yale Law School before beginning his teaching career. From 1992-95 he was the co-director of the Center for International Studies at New York University Law School. Professor Fox is the recipient of a MacArthur Foundation/Social Science Research Council Fellowship in International Peace and Security. He is the author of numerous scholarly articles, including The Right to Political Participation in International Law, 17 Yale J. Int\u27l L. 539 (1992), which is one of the 10 most cited articles ever published in the Yale Journal. His book, Humanitarian Occupation, reviews the U.N.\u27s experience in administering entire states or portions of states. In other academic work, Professor Fox has examined the state of occupation law, arguing against efforts to endow occupying powers with virtually unlimited authority to transform the states they control. In addition to his academic work, Professor Fox has served as counsel in several international cases.
Timestamps:
0:00 Introduction1:40 A primer on Somalia and its history 6:40 International humanitarian intervention9:50 Post-Cold War Era Opportunities15:33 Preparing to go into Somalia24:27 The pros and cons of intervention23:04 U.S. intervention after the Vietnam War24:43 The challenges of intervening in civil wars33:47 Urban warfare43:14 Legacies of the Battle of Mogadishu52:06 UN debates over humanitarian intervention54:55 Somalia after the Battle of Mogadishu
Further Reading:
Bowden, Mark, Black Hawk Down: A Story of Modern War (1999)
Carroll, Jonathan, “Courage Under Fire: Reevaluating Black Hawk Down and the Battle of Mogadishu,” 29 (3) War in History 704 (July 2022)
Fox, Gregory H., Humanitarian Occupation (2008)
Hakimi, Monica, “Toward a Legal Theory on the Responsibility to Protect,” 39(2) Yale J. Int’l L. 247 (2014)
Lee, Thomas H., “The Law of War and the Responsibility to Protect Civilians: A Reinterpretation,” 55 Harv. Int’l L.J. 251 (2014)
Luttwak, Edward N., “Give War a Chance,” Foreign Affairs (July/August 1999)
Hathaway, Oona A. & Hartig, Luke, “Still at War: The United States in Somalia,” Just Security (Mar. 31, 2022)
Wheeler, Nicholas J., Saving Strangers: Humanitarian Intervention in International Society (2002)https://scholarship.shu.edu/law-on-film-s03/1003/thumbnail.jp
GLOBAL MODELLING OF THE FIRST THREE TORSIONAL STATES OF METHANOL ( = 0, 1, 2, = 30): CHOH AND CHOH
No full textAuthor Institution: Department of Physical Sciences and Centre for Laser, Atomic, and; Molecular Sciences, University of New Brunswick, Saint John, NB E2L 4L5,; Canada; Optical Technology Division, National Institute of Standards and Technology,; Gaitherburg, MD 20899-8441; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA 91109Methanol is an important interstellar molecule that was first discovered in space in 1970. Because of the torsional motion, the methanol spectrum is extremely rich and complicated, representing a significant challenge for global modeling. Previous successful modeling efforts from the UNB group included the first two torsional states ( = 0 and 1) up to = 20 for CHOH, CDOH, CDOD and CHOH. With new telescopes and space missions, there are increased demands for methanol data, in order to help astronomers remove interstellar methanol "grass" and thus uncover new molecular species in the interstellar medium. We have quite recently managed to model the CHOH Fourier-Transform far-infrared data and literature microwave and millimeter-wave measurements to their respective experimental uncertainties for the first three torsional states ( = 0, 1 and 2). The fitted data set includes about 500 microwave and millimeter-wave lines and 16762 Fourier-transform transitions covering the quantum number ranges = 30, = 15 and = 2. With incorporation of about 80 adjustable parameters, the global fit achieved convergence with an overall weighted standard deviation of 1.12, essentially to within the assigned measurement uncertainties of 50 kHz for almost all of the microwave and millimeter-wave lines and 6 MHz (0.0002cm) to 15 MHz (0.0005cm) for the Fourier transform far-infrared measurements. The challenges to model the CHOH data set are several times larger than those for the O species, because we have several thousand newly measured THz transitions from the new JPL spectrometer. After carefully scrutinizing measurement uncertainties and assignments, there are good indications that a similar quality fit may be achieveable for CHOH as was achieved for the O species. We hope that information will be available for presentation in June on results from global fits of the normal species up to = 2 and = 30
Optimization of LPCVD-SiNx Membranes for Micro-hotplate/Nano-reactors
No full textMicro-hotplate and Micro-hotplate integrated Nano-reactors are a revolution for in-situ observations in Transmission Electron Microscopy (TEM) imaging. They currently operate at about 400oC without any problems. The SiNx membranes of micro-hotplate and Nano-reactors have integrated micro-heater along with electron transparent windows. The major problem is the shift in 'z' direction of the membranes as a function of pressure and temperature. This creates a change in focus during in-situ TEM imaging affecting the image quality. Net compressive forces can be a reason for bending of membranes, as far as temperature is concerned. Thus, introduction of residual tensile stress was considered to solve this problem. Simple COMSOL simulations were made using plate models to verify the effect of residual tensile stress in membranes as a function of temperature and pressure individually, as well as a combination of both. It was concluded that residual tensile stress does reduce thermal buckling. It also reduces the bulging due to pressure but bulging as a function of pressure can't be made zero. It also concludes thermal buckling is more dominant at lower pressure and pressure bulge is more dominant at higher pressure. Different residual stress LPCVD SiNx films were deposited and material properties like Young's modulus, refractive index and density were characterized. A saturation to the deposition and residual tensile stress was found as a function of gas-ratio. Surface morphology and IR spectra were also determined using AFM and FTIR respectively. All the characterization done proves the change in material composition with fabrication parameters. The introduction of high residual stress questions the reliability of the membrane and hence, there was a need to check if high tensile residual stress doesn't break the membranes. Thus, a new device for wafer level pressure testing of membranes was designed and fabricated. The pressure bulge test was done and reflections were recorded for various pressure and stress levels. The membranes were found reliable up to a pressure of 1.5 bar. New generation of micro-hotplates were fabricated using this concept and an increment 400oC in the operating temperature of micro-hotplates and nano-reactors, without any-shift in 'z' direction due to temperature, was achieved.Electrical Engineerin
Managing pollution control in Brazil : the potential use of taxes and fines by federal and state governments
No full textThe authors make a case for federal monitoring of state environmental agencies'(SEPAs') performance because of the tradeoff for the states between the need to raise revenue from taxes on local output and the need to limit pollution. They also show that fines and taxes assigned respectively to the federal and state governments can improve firms'compliance and SEPA's performance, and hence environmental quality, without damaging state revenue, and perhaps even improving it. For their analysis, the authors rely on numerical policy simulations based on an analytical framework designed as a multilevel Stackelberg game. This framework reproduces the hierarchical structure of pollution control policies in Brazil, where the federal environmental protection agency relies on SEPAs to ensure that federally defined minimum ambient standards are met locally. The numerical simulations are based on a case study of the food, and the printing and publishing industries.Urban Services to the Poor,Environmental Economics&Policies,Water and Industry,Pollution Management&Control,Health Monitoring&Evaluation
Design and fabrication of high-performance indium gallium phosphide/gallium arsenide heterojunction bipolar transistors
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Reason: ETDs are only available to UIUC Users without author permissionETDs are only available to UIUC Users without author permissionThe heterojunction bipolar transistor (HBT) is a device whose time has come. The high gains, linearity, power efficiencies, current handling capabilities, and speeds available with HBT technology make this device attractive for a wide variety of applications from wireless communications to high-speed analog-to-digital converters. Companies across the United States are investing millions of dollars in developing HBT products and manufacturing capabilities.A manufacturable fabrication process for state-of-the-art InGaP/GaAs HBTs has been established. The process features nonalloyed emitter metal, self-aligned emitter and collector etches, self-aligned base metal, mesa isolation, polyimide planarization, and an air bridge metallization. A citric acid-based, selective GaAs etch has been developed for use in the self-aligned emitter etch/base metallization process. The etch has demonstrated excellent control and the uniformity necessary for high-yield wafer processing. The citric acid etch has also been used to implement the selective collector etch which minimizes the base-collector parasitic capacitance. An evaporated gold air bridge process has been developed and replaces a plated gold process, thereby improving yield and quality.State-of-the-art InGaP/GaAs HBTs have been developed. A baseline device structure and the standard fabrication process have consistently produced devices with a common-emitter current gain a common-emitter breakdown voltage BV\sb{\rm CEO}>10 V, a current gain cutoff frequency f\sb{\rm T}>50 GHz, and a maximum frequency of oscillation f\sb{\rm max}>100 GHz. Advanced device structures have been investigated for improving device performance and f\sb{\rm T}'s as high as 93 GHz, and f\sb{\rm max}'s as high as 197 GHz have been achieved. For power applications, InGaP/GaAs double heterojunction bipolar transistors (DHBTs) were analyzed and a composite collector structure has been optimized to improve DHBT operating characteristics. Finally, a submicron, self-aligned emitter ledge structure has been demonstrated, which is formed using wet chemical selective etches and does not require additional masking layers as do present ledge fabrication technologies.Presently, the leading HBT material technology is AlGaAs/GaAs. However, the InGaP/GaAs material system offers significant advantages in device performance and manufacturability. The band alignment of InGaP/GaAs improves device performance and the absence of aluminum in the emitter improves noise characteristics and long-term reliability. In addition, the availability of highly selective etch chemistries makes it easier to manufacture InGaP/GaAs HBTs. This work demonstrates the manufacturability and performance potential of InGaP/GaAs HBTs.Made available in DSpace on 2011-05-07T12:30:09Z (GMT). No. of bitstreams: 2
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Trading arrangements and industrial development
No full textHow do different trading arrangements influence the industrialization process of developing countries? Can preferential trading arrangements (PTAs) be superior to multilateral liberalization, or at least an alternative when multilateral liberalization proceeds slowly? If so, what form should the PTAs take? Are developing countries better advised to seek PTAs with industrial countries or among themselves? Traditional analysis of these issues has been based on the idea of trade creation and trade diversion. The problem with this analysis is that it starts from assuming a pattern of comparative advantage of newly industrialized countries. The experience of these countries suggests the need for an analysis in which the pattern of comparative advantage is not set in stone but is potentially flexible, and in which less developed countries can develop and converge in both income and economic structure to industrial economies. The authors outline an alternative approach for analyzing the role of trade in promoting industrial development. There are few fundamental differences between countries that generate immutable patterns of comparative advantage. Instead the pattern of trade and development in the world economy is determined mainly by history. Cumulative causation has created concentrations of industrial activity in particular locations (industrial countries) and left other areas more dependent on primary activities. Economic development can be thought of as the spread of these concentrations from country to country. Different trading arrangements may have a major impact on this development process. By changing the attractiveness of countries as a base for manufacturing production they can potentially trigger or postpone industrial development. This approach explains why firms are reluctant to move to economies that have lower wages and labor costs, and shows how trade liberalization can change the incentives to become established in developing countries. It provides a mechanism through which import liberalization can have a powerful effect in promoting industrialization. And it suggests that import liberalization may create or amplify differences between liberalizing countries with the possible political tensions this may create. While these features are consistent with the world economy, they fall short of providing convincing empirical support for the approach. Using the approach, the authors derive number of conclusions about the effects of trade liberalization. First, that unilaterally liberalizing imports of manufactures can promote development of the local manufacturing industry. The mechanism is forward linkages from imported intermediates, but this may be interpreted as part of a wider package of linkages coming from these imports. Second, the gains from liberalization through PTA membership are likely to exceed those obtained from unilateral action. South-South PTAs will be sensitive to the market size of member states, and North-South PTAs seem to offer better prospects for participating Southern economies, if not for North and excluded countries. Third, the effects of particular schemes (such as the division of benefits between Southern economies) will depend on the characteristics of the countries and cross-country differences in these characteristics.Economic Theory&Research,Environmental Economics&Policies,Water and Industry,Labor Policies,Banks&Banking Reform,Economic Theory&Research,Environmental Economics&Policies,TF054105-DONOR FUNDED OPERATION ADMINISTRATION FEE INCOME AND EXPENSE ACCOUNT,Trade and Regional Integration,Water and Industry
Charisma and Spirituality in the Early Church: A Study of Messalianism and Pseudo-Macarius
No full textThe thesis is an investigation into the concept of Charisma and Spirituality in the Early Church with particular emphasis upon the writings of Ps-Macarius, and of a group of ascetics known as the Messalians, evident in the late fourth / early fifth centuries. The Macarian writings are
examined to see what they reveal about the experiential pneumatic theology of the Early Church, the relationship between Syrian and Hellenic traditions of Christian Rhetoric, and the relationship between Ps-Macarius and the Cappadocian Circle. The Macarian corpus as a whole is examined to assess its rhetorical influences and style. The rhetoric of the Macarian corpus is seen to illustrate a high degree of sophistication. This study also gives definition to two terms that have become imprecise and diverse in their use: 'enkrateia' (self-control), and
`Syrian Christianity'. By isolating the characteristics of enkratefa the definitive stages of an encratic lifestyle are identified. The breaking down of the term into enkrateia, radical enkrateta and exclusive enkrateta enables a much clearer discussion to take place as to the
nature of the encratic theology of a group or individual. The final element of this study is a consideration of the distinct Macarian imagery that is evident within the corpus. Two images are considered in detail, the 'flight of the soul' and 'sober intoxication'. Overall this study
shows the variety of influences upon Ps-Macarius, and the uniqueness of his expression. The influences upon Ps-Macarius include a context of endemic Syrian spirituality, a radical encratic lifestyle, a Hellenic rhetorical training, and a distinct interpretation of Platonic and Neo-
Platonic images, coupled to the wider Judaic / Mesopotamian influences of his Church. It is shown that Ps-Macarius represents an individual voice that is distinct and recognisable amongst the Fathers of the Church
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