X-ray imaging with “edge-on” microchannel plate detector: first experimental results

A novel scanning slit X-ray imaging system based on an “edge-on” microchannel plate detector was developed and tested. Images were acquired at 50 kV(p) X-ray tube voltage with a limiting spatial resolution of 7 lp/mm. The pixel noise was measured to be 0.3 count/pixel/s for a 50×70 μm² pixel size. This photon counting detector can be considered to be virtually noise free.     

A simple power supply and control unit for pulsed operation of a microchannel plate imaging detector

A simple power supply and control electronic system to operate microchannel plate (MCP) detectors for imaging transient events such as X-ray emission from laser-produced plasmas is described. The power supply consists of two parts, viz. a high voltage pulse generator of 1 kV amplitude with a variable pulse duration of 100 μs to 1 ms for the MCP input, and a regulated 5 kV d.c. for biasing the phosphor screen. The control unit synchronizes the high voltage pulse with the event and operates a safety switch to guard the detector against any accidental rise in the background pressure. A signal-to-noise ratio ≥ 75 is obtained, limited by the noise contribution of the Charge Coupled Device (CCD)-frame grabber combination attached to the MCP. The system is compact, has provision for both positive and negative pulses, is extendable to higher voltages for operating two-stage MCP, and is immune to electromagnetic interference.     

A “Six Sigma”© Black Belt Case Study: G.E.P. Box's Paper Helicopter Experiment Part A

This article presents an application of the “Six Sigma” DMAIC model to G.E.P. Box's famous “paper helicopter” experiment. The define, measure, and analyze phases are presented here, and the improve and control phases are presented in a follow-up article. The intent of this article is to present the reader with a case study for structuring a “Six Sigma” Black Belt project.     

Kinetic Modeling of “Go Slow” Dialysis in Acute Renal Failure

Go slow” dialysis is a gentle, intermittent hemodialysis therapy for acute renal failure patients, with advantages compared to slow, continuous therapies. It employs a recirculating closed dialysate circuit. A two-pool urea kinetic model is elaborated to determine kinetic parameters from blood and dialysate concentrations. This will allow quantification of the therapy. Variable clearance is included to accurately describe the kinetic process. The model is tested in an acute renal failure patient. Solute removals, as determined from direct dialysis quantification and by the model, are comparable. Variable clearance is not required to determine the kinetic parameters, because the constant mean clearance delivers equal results. The dialysis dose, as defined, allows comparison with chronic renal therapies. It requires solute removal determined from dialysate sampling and time-averaged concentration (TAC) from the urea kinetic modeling. In the test patient, dialysis dose is lower compared to standard thrice-weekly therapies because of its lower efficiency and higher TAC, a result of his highly catabolic state.     

Prüfung der mechanischen Eigenschaften von “Quenching und Partitioning”‐Gefügen mit berührungsloser Dehnungsmessung

The “Quenching and Partitioning” (“Q&P”) concept was designed to fill the gap between the first and second generation of Advanced High Strength Steels (AHSS). It aims at a multiphase microstructure of retained austenite in a matrix of carbon depleted martensite. The martensitic components enhance the strength properties. The ductility is improved by the TRIP effect. This work investigates the “quenching and partitioning” response of a nickel and silicium alloyed TRIP steel. After “quenching and partitioning” processing the mechanical properties are evaluated by tensile testing. An adapted specimen geometry and the contact free measurement of the elongation by a laser speckle system are used. The mechanical properties of the “quenching and partitioning” microstructure are compared to the fully martensitic state and reviewed with respect to published data. Additional tests are stopped after a well defined plastic deformation. Subsequently the retained austenite fraction is measured magnetically in the test length. As a result the TRIP effect can be evaluated. The “quenching and partitioning” processing leads to tensile strengths of around 1300 MPa at elongations of more than 10 %. The martensitic microstructure exhibits a higher tensile strength and lower elongation values. The decreasing fraction of retained austenite with plastic deformation implies the TRIP effect. Comparable mechanical properties are reported in the published literature. The proposed method of annealing and adapted testing shows effective for the investigation of sophisticated heat treatment procedures.     

The atmospheric nightglow in the 300–400 nm wavelength Results by the balloon-borne experiment “BABY”

The balloon-borne experiment, named BAckground BYpass (BABY) belongs to a wider program that has as its final goal the detection and study of high-energy cosmic rays from space (satellite, Space Station). An information of fundamental importance for this class of projects concerns the nighttime background light. The instrument designed to detect fluorescence photons is basically composed of two collimated photomultipliers: a single photon-counting PMT and a charge integration PMT. We briefly report the details of the design, operation and performance of the detector, which was designed and completely built at the IFCAI–CNR Institute in Palermo. Preliminary analysis and results of the nocturnal background in the range of 300–400 nm are presented for the whole duration of the flight during the 1998 Mediterranean balloon flight campaign. A substantial part of the flight was at night over the sea.     

Arguments for a “US Kamioka”: SNOLab and its implications for North American underground science planning

We argue for a cost-effective, long-term North American underground science strategy based on partnership with Canada, initial construction of a modest US Stage I laboratory designed to complement SNOLab, and follow-up stages to create clean horizontal access to greater depths. We show, by reviewing the requirements of detectors now in the R&D phase, that SNOLab and a properly designed US Stage I facility would be capable of meeting most needs of North America's next wave of underground experiments.One opportunity for creating such a laboratory is the Pioneer tunnel in Washington State, a site that could be developed to provide dedicated, clean, horizontal access. This unused tunnel, part of the deepest (1040 m) tunnel system in the US, would allow the US to establish, at low risk and modest cost, a laboratory at a depth (.w.e., or kilometers of water equivalent) quite similar to that of the Japanese laboratory Kamioka (.w.e.). The site's infrastructure includes highway and rail access to the portal, a gravity drainage system, redundant power, proximity to a major metropolitan area, and a system of crosscuts connecting to the parallel Great Cascade tunnel and its ventilation system. We describe studies of cosmic ray attenuation important to properly locating such a laboratory, and the tunnel improvements that would be required to produce an optimal Stage I facility.We describe the unique role this location could play in formulating an international plan for high-energy accelerator physics that includes, as one component, a neutrino factory. The site has a “doubly magic” baseline—a separation from both KEK and CERN—as well as an appropriate baseline for CP violation studies, should FermiLab host the neutrino factory.We also describe how new space at greater depth could be added in response to the needs of future experiments, building on the experience gained in Stage I. We discuss possible designs for Stage II (.w.e.) and Stage III (.w.e.) developments at the Pioneer tunnel, should future North American needs for deep space exceed those available at SNOLab. This staging could be planned to avoid duplication of SNOLab's capabilities while minimizing construction and operations costs. We describe the existing geotechnical record important to future stages, including past tunneling histories, borehole studies and analyses, and recent examinations of the Pioneer tunnel. We also describe the significant broader impacts of this project in improving the efficiency, safety, and security of one of the nation's key transportation corridors.     

Panoscopic Silicon—A Material for “All” Length Scales

Silicon is the “veteran” semiconductor in the management of electrons. The recent quest for optoelectronic and photonic materials suggests that new architectures of silicon structured over multiple length scales may still be the optimum material for the transition from electron‐based to photon‐basped computers and communication systems. This Research News article is focussed on recent research accomplishments in fabrication and self‐assembly methods of shaping elemental silicon over nanometer to micrometer length scales for applications in electronics, optoelectronics, and photonics.     

A note on “A simple approach to search for all d-MCs of a limited-flow network”

Many real-world systems are multi-state systems composed of multi-state components in which the reliability can be computed in terms of the lower bound points of level d, called d-Mincuts (d-MCs). Such systems (electric power, transportation, etc.) may be considered as network flows whose arcs have independent and discrete random capacities. In this comment, we investigate the algorithm proposed by Yeh [A simple approach to search for all d-MCs of a limited-flow network. Reliability Engineering and System Safety 2001;71(1):15–19]. We show that the algorithm misses some real d-MCs, and then pinpoint the algorithm's failure and suggest the correcting point.     

A generalization of Gittus’ viscoplastic “mechanical equation of state” to multiaxial stress states

In this paper, a multiaxial generalization of the viscoplastic “mechanical equation of state” (MEOS) by Gittus is proposed that preserves the physical soundness of the theory. The concept of forward and backward mobility of dislocations is generalized to a concept of directional mobility by splitting the mobile dislocation density in an isotropic and a tensorial part, similar to the approach used in the Bodner unified viscoplastic model. It is shown that the formulation is equivalent to the original MEOS in the case of uniaxial loadings. The approach is easily applied to any uniaxial viscoplastic material model.     

Copper electrowinning from acid mine drainage: A case study from the closed mine “Cerovo”

Copper removal from acid mine drainage originating from closed copper mine “Cerovo” RTB Bor, Serbia and containing approximately 1.3 g dm⁻³ of copper and a very small amount of Fe²⁺/Fe³⁺ ions, has been successfully performed by the direct electrowinning method using either a porous copper sheet or carbon felt as the cathode. A cell with a fluidised bed of inert turbulent promoters, also used in this study, may be considered as unacceptable for the purpose view, having a cell voltage between 12 and 14 V.The cells used in the electrowinning experiments were compared in terms of cell voltage, pH and copper concentration. The results showed that it is possible to remove copper successfully from the mine waters with a high degree of electrowinning—higher than 92% and with a satisfactorily average current efficiency (>60%). Depending on the process time and the applied current, a final copper concentration less than 0.1 g dm⁻³ was achieved. The specific energy consumption was approximately 7 kWh kg⁻¹ of deposited copper. A dense copper deposit was obtained when a three-dimensional electrode was used.     

“Electro‐Typing” on a Carbon‐Nanoparticles‐Filled Polymeric Film using Conducting Atomic Force Microscopy

Next‐generation electrical nanoimprinting of a polymeric data sheet based on charge trapping phenomena is reported here. Carbon nanoparticles (CNPs) (waste carbon product) are deployed into a polymeric matrix (polyaniline) (PANI) as a charge trapping layer. The data are recorded on the CNPs‐filled polyaniline device layer by “electro‐typing” under a voltage pulse (V_ET, from ±1 to ±7 V), which is applied to the device layer through a localized charge‐injection method. The core idea of this device is to make an electrical image through the charge trapping mechanism, which can be “read” further by the subsequent electrical mapping. The density of stored charges at the carbon–polyaniline layer, near the metal/polymer interface, is found to depend on the voltage amplitude, i.e., the number of injected charge carriers. The relaxation of the stored charges is studied by different probe voltages and for different devices, depending on the percolation of the CNPs into the PANI. The polymeric data sheet retains the recorded data for more than 6 h, which can be refreshed or erased at will. Also, a write–read–erase–read cycle is performed for the smallest “bit” of stored information through a single contact between the probe and the device layer.     

Development and validation of “grey-box” models for refrigeration applications: A review of key concepts

“Grey-box” modelling combines the use of first-principle based “white-box” models and empirical “black-box” models, offering particular benefits when: (a) there is a lack of fundamental theory to describe the system or process modelled; (b) there is a scarcity of suitable experimental data for validation or (c) there is a need to decrease the complexity of the model. The grey-box approach has been used, for example, to create mathematical models to predict the shelf life of chilled products or the thermal behaviour of imperfectly mixed fluids, or to create models that combine artificial neural networks and dynamic differential equations for control-related applications. This paper discusses the main characteristics of white-box, black-box and their integration into grey-box models, the requirements and sourcing of accurate data for model development and important validation concepts and measures.     

Reply to “Comments on ‘Geomechanical and Geochemical Evidence of Piezonuclear Fission Reactions in the Earth's Crust’ by A. Carpinteri and A. Manuello” by U. Bardi and G. Comoretto

In the paper entitled “Comments on ‘Geomechanical and Geochemical Evidence of Piezonuclear Fission Reactions in the Earth's Crust’ by A. Carpinteri and Manuello” by U. Bardi and G. Comoretto, the authors criticise the hypothesis based on piezonuclear reactions for the interpretation of the compositional evolution of the Earth's crust. We report a detailed reply of how the traditional theories, used by the authors of the comments, are obviously inadequate to describe this new kind of nuclear phenomena. Only very recently, independent authors proposed a theoretical model explaining the anomalous energy emissions in the form of neutrons, involved in piezonuclear reactions, during fracture of nonradioactive rocks. It is also known how the evidences that Bardi and Comoretto claim to be non‐existent could be found in many independent works that appeared in most important journals about unexplained questions of the Earth's crust and environment. The data reported in the original work and the details included in this reply show that it is incorrect to consider impossible or simply to ignore the existence of unexplained phenomena only because they cannot be described by traditional models and conventional theories.     

EUROCONTROL—Systemic Occurrence Analysis Methodology (SOAM)—A “Reason”-based organisational methodology for analysing incidents and accidents

The Safety Occurrence Analysis Methodology (SOAM) developed for EUROCONTROL is an accident investigation methodology based on the Reason Model of organisational accidents. The purpose of a SOAM is to broaden the focus of an investigation from human involvement issues, also known as “active failures of operational personnel” under Reason's original model, to include analysis of the latent conditions deeper within the organisation that set the context for the event. Such an approach is consistent with the tenets of Just Culture in which people are encouraged to provide full and open information about how incidents occurred, and are not penalised for errors.A truly systemic approach is not simply a means of transferring responsibility for a safety occurrence from front-line employees to senior managers. A consistent philosophy must be applied, where the investigation process seeks to correct deficiencies wherever they may be found, without attempting to apportion blame or liability.     

A “Six Sigma”© Case Study: G.E.P. Box's Paper Helicopter Experiment—Part B

This article presents an application of the “Six Sigma” DMAIC model to G.E.P. Box's famous “paper helicopter” experiment. The Improve and Control Phases are presented here. The Define, Measure, and Analyze Phases were presented in an earlier paper. The intent of this article is to present the reader with a case study for structuring a “Six Sigma” project.