The universe—present,past and future

A review of The Superpower Space Race: An Explosive Rivalry through the Solar System. By Robert Reeves. (Plenum, 1994) [Pp. xiv + 437.] US$ 28·95 (hbk). ISBN 0 306 447681. Scope: popular review. Level: general reader.     

Magnetic rotation — past,present and future

Magnetic-dipole rotational (MR) bands were discovered about 15 years ago without any theoretical prediction in contrast to the super-deformed (SD) bands which were predicted long ago. First identification of a quasirotational structure as MR band occurred around 1992 although Kr isotopes probably have the first set of data having the signatures of MR bands as shown by us. Our first compilation of MR bands listed 120 MR bands in 56 nuclides which have now grown to more than 180 bands in 80 nuclides. We have observed new MR bands in the A = 130 mass region in ¹³⁷Pr, ¹³⁹Nd and ¹³⁵Ba nuclei. This led to the observation of the smallest MR bands in ¹³⁷Pr, multiple minima in the γ deformation in ¹³⁵Ba, coexistence of band structure based on these minima and band crossing of MR bands in A = 130 region. Some of these results have been reviewed in this paper along with theoretical calculations. There are still a number of questions related to MR bands which have not been fully resolved. The role of neutrons/protons in magnetic rotation still needs to be delineated. Do the MR bands follow the I(I + 1) behaviour? Are these structures as regular as normal rotational bands? How important is the existence of deformation for MR bands? We address some of these questions in this paper.     

Judd—Ofelt theory: past,present and future

The original Judd-Ofelt theory is briefly presented in the terms of effective operators defined in the traditional form that has been used for many years for the interpretation of the f spectra of rare earths. The semi-empirical approach of the Judd-Ofelt theory that defines the one-particle parametrization scheme is modified here. The unit tensor operators that act within the orbital space are replaced by double tensor operators acting within the spin-orbital space. This extension enables one to include the impact of the relativistic effects upon the transition amplitude. At the same time it leads to a generalization of the theoretical approach to f ? f transitions, especially in the case of those that are not described by the standard scheme.     

M?ssbauer spectroscopy database: past, present, future

M?ssbauer Spectroscopy is a useful tool for scientific research in many fields, lots of researchers benefited from this technology which discovered by Rudolf M?ssbauer. Up to now, there are more than one million M?ssbauer data records present in public papers and books, and the number is increasing. Most of these data records have been collected by M?ssbauer Effect Data Center (MEDC) since 40 years ago, and now all these data records can be seen on the web of database. MEDC, as a part of M?ssbauer community, is and always will be offering better service with the help of the entire community.     

The future of microstructure technology — The industry view

Downscaling of minimum device and circuit geometries has been the primary engine driving exponential improvements in integrated circuit density, performance and cost for 20 years or more. These improvements have permitted concomitant progress in electronic systems, and and are largely responsible for the growth of the market. Semiconductor device and circuit modeling predicts practical limits on these geometries, and analysis of current trends indicates that these limits will be reached for circuits comprising large portions of the IC market by the mid-90's.The limitations on downscaling are both device- and interconnection-related and encompass noise and reliability issues. The practical limits are in the range 0.3 – 0.5 micrometers, but limits of a somewhat more fundamental nature exist around 0.1 – 0.3 micrometers. Since the practical limits are expected to be reached in the early- to mid-'90's, keeping functional density on its current exponential trend for more than a few years after that will require revolutionary approaches to devices, interconnections, noise immunity, and fault-tolerace.The discontinuity which maturation of the evolutionary transistor-based technology will create will present a rare opportunity to “go back to the well” of science to create a new technology of potentially large and immediate impact. In our view, which we believe to be shared by the industry, this must be a technology which leverages the accumulated experience and investment in semiconductor manufacturing in order to maintain the downward cost trend. Much of the required basic research in semiconductor microstructures in the regimes of quantum size effects and tunneling is yet to be done. Filling in this research gap should be a major priority for the immediate future, and the ability to do this will depend on continued progress in microstructure fabrication.     

The laboratory of acoustics,speech and signal processing at the institute of acoustics

The Laboratory of Acoustics,Speech and Signal Processing(LASSP),theunique and superior national key laboratory of ASSP in China,has been foundedat the Inst.of Acoustics,Academia Sinica,Beijing PRC.After three years ofefforts,the construction of the LASSP has been completed successfully and thecertain capability of performing frontier research projects in fundamental theory andapplied technology of sound field and acoustic signal processing has ben formed.A fiexible and complete experimental acoustic signal processing system hasbeen set up in the LASSP.With the remarkable advantage of real time signalprocessing and resource sharing,a wide range of research projects in the field ofASSP can be conducted in the laboratory.The Signal Processing Center of theLASSP is well equipped with many computer research facilities including the     

Reactor neutrinos—present and future

The main characteristics of experimental searches for neutrino oscillations at nuclear reactors are reviewed. We then describe the Chooz and Palo Verde experiments and report their results to date. We also describe the KamLAND experiment, presently under construction in the Kamioka laboratory in Japan, which is designed to extend the sensitivity to ν_e ? ν_X oscillations by two orders of magnitude in Δm ². In particular, this experiment expects to be able to carry out a terrestial test of the large-angle MSW solution to the solar neutrino problem.     

Photocathodes—past performance and future potential

Light detection and imaging at very low intensities, even down to individual photon detection, has been made possible by the development of photomultiplier and imaging tubes. They have two main components: a photocathode detector and an electron multiplication section, but throughout their long history their performance has been limited by the response of the photocathodes. Reappraisal of the underlying science of cathode preparation emphasizes that they are still performing well below their full potential. The reasons for this are discussed and some indications of how improvements could be made are suggested. Since many of the potential advances are within the scope of current technology it is certainly feasible to achieve enhancements in performance by factors of two to ten across the blue to near-infrared spectral range. Higher improvement factors are implied but will be difficult to realize in the normal spectral range for wavelengths below 1 w m. Significant gains in sensitivity, and perhaps in response speed, will open many new opportunities for low light level sensors and the prediction is that they will be an enabling technology for developments in biological and medical applications, among others.     

Commentary: Roles,opportunities, and challenges—science museums engaging the public in emerging science and technology

Even a cursory reading of the public engagement in science (PES) literature over the past decade reveals that public engagement is becoming part of the “orthodoxy of 21st century science policy” (Stilgoe, Nanodialogues: experiments in public engagement with science, 2007, p 16), Moving forward, there appears to be strong consensus that (1) public engagement is an essential component for shaping sound science policies, research agendas, and governance structures; (2) more opportunities for accessible and successful PES need to be developed and implemented to have meaningful impact; and (3) a broader and more diverse range of publics need to be reached through PES activities. This article explores the role that U.S. science museums and centers could play in creating and delivering PES programming focusing on current science and technology developments and issues, with particular attention to nanoscience and nanotechnology. Also addressed will be some of the factors that support increased PES involvement by museums, some of the challenges museums need to overcome to sustain ongoing PES, and several recommendations to achieve broader PES impact through science museum participation.     

Role of kaon physics,present–future

The main issue for kaon physics in the next decade is a systematic study of the rare decay modes to test the unitarity of the quark flavour mixing matrix, the global symmetries of the Standard Model and new physics with the highest possible precision.     

Experimental limits onM t andM H — present and future

Existing data from precision tests of the electroweak standard model at LEP, the -colliders andvN-scattering experiments constrain the mass of the top quark toM _t =144 _–26–21 ⁺²³⁺¹⁹ GeV, where the central value and first error refer to a Higgs mass value of 300 GeV. The second error shows the variation ofM _t for Higgs mass values spanning the range 50M _H(GeV)<1000. the=" present=" apparent=" sensitivity=" of=" the=" data=" to=" the=" value=" of=" the=" higgs=" mass=" is=" investigated.=" future=" data=" from=" lep=" will=" significantly=" tighten=" the=" bounds=">M _t . Limits onM _H however will remain of order M _H/M _H2 without an independent measurement ofM _t .     

Coded-aperture imaging systems: Past,present and future development – A review

Scintillator based coded-aperture imaging has proven to be effective when applied for X- and gamma-ray detection. Adaptation of the same method for neutron imaging has resulted in a number of propitious systems, which could be potentially employed for neutron detection in security and nuclear decommissioning applications. Recently developed scintillator based coded-aperture imagers reveal that localisation of neutron sources using this technique may be feasible, since pulse shape discrimination algorithms implemented in the digital domain can reliably separate gamma-rays from fast neutron interactions occurring within an organic scintillator. Moreover, recent advancements in the development of solid organic scintillators make them a viable solution for nuclear decommissioning applications as they present less hazardous characteristics than currently dominating liquid scintillation detectors. In this paper existing applications of coded-apertures for radiation detection are critically reviewed, highlighting potential improvements for coded-aperture based neutron source localisation. Further, the suitability of coded-apertures for neutron imaging in nuclear decommissioning is also assessed using Monte-Carlo modelling.     

A review of: “The science of crystallization,microscopic interfacial phenomena”

Abstract

By W. A. Tiller, Cambridge University Press. ISBN 0-521-38827-9     

The universality and the future prospects of physiological energetics: Reply to comments on “Physics of metabolic organization”

In response to the comments on review “Physics of metabolic organization”, we discuss the universality and the future prospects of physiological energetics. The topics range from the role of entropy in modeling living organisms to the apparent ubiquity of the von Bertalanffy curve, and the potential applications of the theory in yet unexplored domains. Tradeoffs in outreach to non-specialists are also briefly considered.     

Answer to “information flow,causality, and the classical theory of Tachyons”

We briefly answer the comments in Information Flow, Causality and the Classical Theory of Tachyons by Basano.Work partially supported by MPI (ex-art. 286 T.U.).     

In vitro fertilization in Japan — Early days of in vitro fertilization and embryo transfer and future prospects for assisted reproductive technology —

Assisted reproductive technology (ART) such as in vitro fertilization (IVF) and embryo transfer (ET) has been essential in the treatment of infertility. The world’s first IVF-ET baby was born in 1978 based on the technique developed by Dr. Robert Edwards and Dr. Patrick Steptoe.¹⁾ In Japan, the first IVF-ET birth was reported in 1983 by Prof. Masakuni Suzuki at Tohoku University School of Medicine.^2,3)IVF-ET is a procedure used to achieve pregnancy that consists of extracting oocytes from an infertile woman, fertilizing them in vitro, and transferring fertilized eggs into the patient’s uterine cavity (Fig. ​(Fig.1).1). Since the first report of successful IVF-ET, numerous techniques related to ART, such as cryopreservation of oocytes and embryos, gamete intrafallopian transfer (GIFT), and microinsemination, have been developed and refined (Table ​(Table11).Open in a separate windowFigure 1. In vitro fertilization and embryo transfer process. A: Induction of ovulation: After menstruation, ovulation is induced to produce multiple oocytes. B: Testing: 1. Follicular diameter is measured using ultrasound. 2. Blood estradiol (E₂) levels are measured. 3. Oocyte maturity is assessed with urinary Luteinizing Hormone (LH) measurements. C: Oocyte retrieval: Ultrasound-guided transvaginal follicle puncture is used to collect oocytes. D: Semen collection: Semen is collected from the husband. E: Sperm preparation: Semen is separated into multiple layers on a thickener effluent, and separated using a centrifuge. (400 × g, 30 min). F: Insemination: The semen and oocytes are placed together in a dish with culture media. G: Confirmation of fertilization: Fertilization is confirmed on the first day after oocyte retrieval. H: Embryo transfer: On the third or fifth day after oocyte retrieval, fertilized eggs are transferred to the uterus through a catheter.

Table 1.

Timeline of reproductive technologies in Japan

Neutrinoless double-beta decay—status of evidence and future

Double-beta decay is indispensable to solve the question of the neutrino mass matrix together with ν oscillation experiments. Recent analysis of the most sensitive experiment in the last eight years—the Heidelberg-Moscow experiment in Gran Sasso—yields evidence for the neutrinoless decay mode at a 97% C.L. This result is the first indication for lepton number violation and for the neutrino to be a Majorana particle. We give the present status of the analysis in these proceedings. It excludes several of the neutrino mass scenarios allowed from present neutrino oscillation experiments—essentially only degenerate and partially degenerate mass scenarios survive. To improve the present result, considerably enlarged experiments are required, such as GENIUS. A GENIUS Test Facility has just been funded and will come into operation by the end of 2002.