Unexpected relations between matrix elements of the three-body scalar operators ti in the f shell

It has been known for some time that crystal-field matrix elements (i.e., matrix elements of sums over spherical harmonics involving the coordinates of the individual electrons) are often unexpectedly proportional to one another in the f shell. To see whether similar relations hold for more complicated operators than those provided by the crystal field, we examined the matrix elements of the three-electron scalar operators t_i for all configurations f^N, as calculated by W. T. Carnall on the basis of the computer program of Hannah Crosswhite. These operators are widely used to take configuration interaction into account, and we found a surprising number of proportionalities that go beyond what would be expected on a straightforward application of the Wigner-Eckart theorem, as applied to the irreducible representations of the classic groups SO(7), G₂ and SO(3) used by Racah in defining the f-electron states. A listing of such relations is provided.     

Chlorination of polystyrene

Chlorination of a low molecular weight polystyrene in the α position was studied by following changes in the infrared spectrum, glass transition temperature, and molecular weights of the polymer. The logarithm of the absorbance ratio at 2920 and 1500 cm^?1 as a function of mole per cent chlorination was linear. The glass transition temperatures, determined by use of a differential scanning calorimeter (DSC), were found to obey an equation developed by Dyvik for copolymers. The molecular weight of the chlorinated polystyrene decreased as a function of chlorination.     

Risk management during requirements

Risk management is project management for adults. This means the manager adopts an adult attitude toward things that might go wrong during the project, a marked difference from the prevailing can-do attitude. The risk manager is obliged to do some cannot-do thinking, to look problems - even potentially unsolvable ones - directly in the eye and acknowledge that they could come to pass. The risk-aware project manager will accept a lucky break if it should happen but refuses to include it in the plan. At the heart of risk management is a public, continuing process of risk identification. Some risks that will threaten your project are utterly unique to your situation, but others are not. Over some 10 years of conducting risk identification exercises in organizations, we have found five risks that are so ubiquitous that we have dubbed them core risks. We focus on the first two core risks and discuss risk management as part of the requirements process: intrinsic schedule flaws-estimates that are wrong (undoable) from day one, often based on nothing more than wishful thinking; and specification breakdown - failure to achieve stakeholder consensus on what to build.     

ITER CODAC interface for the visible and infra-red wide angle viewing cameras

The amount of data generated by the infra-red and visible cameras at ITER is expected to be considerably larger than most diagnostics. ITER will have 12 infra-red cameras plus 12 visible cameras in four different equatorial port plugs. Each of the ports will have a Plant System Host (PSH) that will provide a standard image of the plant system to the ITER's Control and Data Access and Communication (CODAC) system.The two key functions of these cameras will be the scientific exploitation with the detection of interesting physics events and the operational protection of the machine, namely the first wall. Already assuming high bandwidth requirements for both audio and video, ITER will provide a separate network for this kind of communication, which will be used to transmit both the experimental and informational data provided by the cameras.This paper presents the current camera plant system design and its interaction with ITER CODAC system and networks. Starting from the camera specifications several alternatives for data collection and compression are discussed. The required inputs from CODAC and a first specification for the internal finite state machine are also presented. Finally, a possible hardware straw man design solution for the plant system hardware is proposed.     

Drift-free magnetic equilibrium reconstruction using the response to plasma position modulation

Inductive magnetic sensors are widely used for plasma equilibrium reconstruction and control. However, their measurements involve electronic integration and can therefore experience drift leading to inaccurate plasma positioning. For this reason, we have studied an original drift-free approach to estimate the plasma equilibrium. The principle of this correction is based on modulation of the plasma position and current at three independent frequencies and analysing the modulated magnetic signals to provide additional estimation on the equilibrium. Using a plasma model based on current wires, the accuracy of such a method is assessed for Tore Supra in terms of the signal to noise ratio. The plasma position is recovered within a precision of 5 mm for a signal to noise ratio better than 80 dB. Applying our approach to dedicated experiments performed on the Tore Supra tokamak, we confirm the quality of the result and find that we can estimate the radial and vertical positions of the plasma to 1 mm with a one standard deviation confidence interval.     

The magnetics diagnostic set for ITER

The current status of the ITER magnetics diagnostic is summarised. The various risks are discussed on the basis of when they could be present during ITER operation and appropriate mitigation is reviewed. An implementation risk or common mode operation failure risk to the magnetic diagnostic can only be mitigated by diversity. All identified risks are being handled with ongoing research and development to minimise these risks. A reasonable level of design and manufacturing diversity has been therefore introduced in the procurement and installation plans, in order to optimise overall reliability avoiding dispersion of resources.     

Neutral beam deployment on DEMO and its influence on design

The demands on the neutral beam heating and current drive system of a DEMO device exceed those of existing fusion experiments by several orders of magnitude. By predicting possible power waveforms it is possible to analyse the technological advances necessary to achieve a system relevant to deployment on a power plant. Achieving the necessary efficiency will require simultaneous improvements in beam current density, neutralization efficiency and beam transmission. Considering the deployment on the tokamak vessel shows no major disruption to the tritium breeder blanket and no requirement to reach a high packing density of injectors. The thermal management of components subjected to low heat flux for many hours is considered and it is shown that radiation cooling can be exploited to control the temperature of such items.     

Rituximab chimeric anti-CD20 monoclonal antibody therapy for relapsed indolent lymphoma: half of patients respond to a four-dose treatment program

PURPOSE: The CD20 antigen is expressed on more than 90% of B-cell lymphomas. It is appealing for targeted therapy, because it does not shed or modulate. A chimeric monoclonal antibody more effectively mediates host effector functions and is itself less immunogenic than are murine antibodies. PATIENTS AND METHODS: This was a multiinstitutional trial of the chimeric anti-CD20 antibody, IDEC-C2B8. Patients with relapsed low grade or follicular lymphoma received an outpatient treatment course of IDEC-C2B8 375 mg/m2 intravenously weekly for four doses. RESULTS: From 31 centers, 166 patients were entered. Of this intent-to-treat group, 48% responded. With a median follow-up duration of 11.8 months, the projected median time to progression for responders is 13.0 months. Serum antibody levels were sustained longer after the fourth infusion than after the first, and were higher in responders and in patients with lower tumor burden. The majority of adverse events occurred during the first infusion and were grade 1 or 2; fever and chills were the most common events. Only 12% of patients had grade 3 and 3% grade 4 toxicities. A human antichimeric antibody was detected in only one patient. CONCLUSION: The response rate of 48% with IDEC-C2B8 is comparable to results with single-agent cytotoxic chemotherapy. Toxicity was mild. Attention needs to be paid to the rate of antibody infusion, with titration according to toxicity. Further investigation of this agent is warranted, including its use in conjunction with standard chemotherapy.     

Advantages of sharp adventitial dissection for microvascular anastomoses

Adventitia is usually removed from arteries to simplify microvascular anastomoses. Some surgeons peel the adventitia away bluntly whereas others trim the adventitia sharply with scissors. We used a rat cremaster flap for intravital microscopy to evaluate these two techniques. Animals with unmanipulated vessels, without anastomosis or adventitial removal, served as controls. Fifty-four rats were studied in three groups of 18 rats. Functional capillary density, red blood cell velocity, diameter of the flap's feeding artery (A1), microthrombi formation, and neutrophilic activity were studied for 5 hours following anastomosis, and 24 and 72 hours later. Histological changes in blunt and sharply prepared arteries were compared with control vessels. After blunt preparation, capillary perfusion was reduced to 61% of control values (p < 0.05) and A1 diameter was reduced to 77% of control values (p < 0.05). Capillary perfusion and A1 diameter were unchanged in sharply prepared arteries. Architectural changes in the vessel wall were more profound, and neutrophilic activity was increased in bluntly prepared arteries. In this study, sharp preparation of small arteries was beneficial compared with blunt preparation.