Traditional coordinate measuring systems rely on the accurate kinematics of moving a sensor to the workpiece. This paper describes an instrument using a precision rotary stage to rotate a workpiece ...with respect to a set of three laser line sensors. The accuracy of the point cloud obtained from a single rotation of the workpiece is dependent on the rotational accuracy of the stage and knowledge of the location of the line sensors with respect to the rotary axis and each other. The calibration procedure required to locate these line sensors utilizes a precision artefact placed on the rotary stage.
Variability is unavoidable in the realization of products. While design must specify ideal geometry, it shall also describe limits of variability (tolerances) that must be met in order to maintain ...proper product function. Although tolerancing is a mature field, new manufacturing processes and design methodologies are creating new avenues of research, and modelling standards must also evolve to support these processes. In addition, the study of uncertainty has produced widely-accepted methods of quantifying variability, and modern tolerancing tools should support these methods. The challenges introduced by new processes and design methodologies continue to make tolerancing research a fertile and productive area.
Spectrally resolved scattering of ultrafast K-α x-rays has provided experimental validation of the modeling of the compression and heating of shocked matter. The elastic scattering component has ...characterized the evolution and coalescence of two shocks launched by a nanosecond laser pulse into lithium hydride with an unprecedented temporal resolution of 10 picoseconds. At shock coalescence, we observed rapid heating to temperatures of 25,000 kelvin when the scattering spectra show the collective plasmon oscillations that indicate the transition to the dense metallic plasma state. The plasmon frequency determines the material compression, which is found to be a factor of 3, thereby reaching conditions in the laboratory relevant for studying the physics of planetary formation.
Estimation of the uncertainty of Coordinate Measuring Machine (CMM) measurements for real, imperfect parts is a very complex undertaking. Not only are there many contributors to the uncertainty that ...may interact in a non-linear fashion, making it difficult to mathematically determine an uncertainty estimate, but it is also difficult to predict the long-term variation of these parameters. Our work seeks to provide experimental validation of the uncertainties predicted by two different commercial software packages that purport to predict the task-specific measuring uncertainty of CMM measurement results. The validation procedure uses repeated measurements of calibrated artifacts to experimentally determine measurement uncertainties. These measurements can then be simulated in the commercial software packages. The comparison will allow the software to be tested to see if it appropriately accounts for the influences of the operator, environment, and part placement. This paper reports the results of actual part measurements and the predicted uncertainty provided by commercial simulation packages. Differences between experimental and simulated uncertainties are highlighted, and their causes examined.
This book is intended to be used as a textbook and research reference for the field of nuclear nonproliferation. The book is primarily technical and focussed on methods of detecting clandestine ...nuclear material that might be illicitly transported. The book also touches on nuclear forensics, i.e. methods for identification, attribution, and establishment of transport pathways for illicit nuclear material. Also covered are topics of methods used for arms control and treaty verification, and an assessment of technologies under development for all of the above. A description of the government and international agencies involved in nuclear terrorism prevention, nuclear safeguards, and arms control is also included.
Au foils were irradiated with a 100-TW, 100-fs laser at intensities greater than 10(20) W/cm2 producing proton beams with a total yield of approximately 10(11) and maximum proton energy of >9 MeV. ...Removing contamination from the back surface of Au foils with an Ar-ion sputter gun reduced the total yield of accelerated protons to less than 1% of the yield observed without removing contamination. Removing contamination from the front surface (laser-interaction side) of the target had no observable effect on the proton beam. We present a one-dimensional particle-in-cell simulation that models the experiment. Both experimental and simulation results are consistent with the back-surface acceleration mechanism described in the text.
Semitransparent organic photovoltaics (OPV) possess unique properties that make them highly appealing for their integration into semitransparent architectonic elements such as windows or glazings. In ...order to provide sufficient transparency, non-opaque electrodes and thin photoactive layers are typically used, thus limiting the light-harvesting capacity. This can be partially overcome by using materials that absorb light mostly in the infrared region. On the other hand, the use of scalable techniques for the fabrication of semitransparent devices is often disregarded. In this work, we combine the blue, low-bandgap polymer PBTZT-stat-BDTT-8 with the near-infrared absorbing non-fullerene acceptor 4TICO, adapting the module fabrication to low-cost manufacturing processes that are compatible with large-scale production. Fully solution-processed semitransparent solar cells over 4.7% performance are prepared from non-chlorinated formulations, in air and using scalable techniques such as blade coating. Our prototypes of semitransparent laser-patterned OPV modules exceed 30% of transparency (measured as human perception transmittance, HPT) and yield efficiencies in the range of 4%, geometrical fill factors surpassing 90% and an active area above 1 cm 2 . We verify the quality of cell-to-cell interconnection and optimise the geometry of the modules with the help of local optoelectronic imaging techniques. This work highlights the relevance of non-fullerene acceptors with strong absorption in the near-infrared, as they can meet industrial and technical requirements for the upscaling and integration of high-performance semitransparent OPV modules with low production costs.
The publication of the latest edition of ISO 1101 in 2017 is a landmark event in the development of ISO tolerancing standards. It represents an important milestone in the evolution of ISO tolerancing ...standards powered by a synergy between technological developments in tolerancing (for specification) and metrology (for verification). The external forces that caused this synergistic evolution stem from digitization of manufacturing (also variously called Smart Manufacturing, Cyber-Manufacturing, Cyber-Physical Production Systems, and Industrie 4.0). This paper provides a brief analysis of a new set of customer-facing ISO tolerancing standards which, along with their promises and challenges, will have a significant impact on digitization of manufacturing.
The power of proline: Bold amino acid substitutions in sensitive protein regions are frequently unproductive, while more subtle mutations can be sufficient to bring about dramatic changes. But ...introducing proline at the residue next to the sulfur ligand in P450BM₃ (CYP102A1) has the unexpected and desirable effect of enhancing the activity of this fatty acid hydroxylase with a broad range of non-natural substrates, as illustrated by the figure.
Navigating the Perils of Ransomware Morse, Edward A.; Ramsey, Ian
The Business Lawyer,
12/2016, Letnik:
72, Številka:
1
Journal Article, Trade Publication Article
Recenzirano
According to McAfee, " generally, there is no need to enable macros to view the contents of a document. Economic sanctions are rooted in laws that implement political policies by regulating private ...commercial actors in order to support foreign policy and national security goals.18 OFAC maintains a searchable database of designated parties and relevant sanction restrictions.19 Thus, payments made to designated parties or countries covered by sanctions are clearly illegal, potentially resulting in civil or criminal penalties not only for those making the payments, but also for those facilitating them.20 Although banks are accustomed to consulting the OFAC database when making payment abroad to a designated payee, a firm making a bitcoin payment via e-mail will likely not have the name or location of the designated payee. ...the sanctions regime is unlikely to affect a ransom payment, except in cases when the criminal self-identifies in a manner triggering the sanctions regime.