Theoretical and experimental studies of the underlying processes and techniques of low pressure measurement Progress report, 1 Jun. 1966 - 31 May 1967

Construction, testing, and refining of vacuum gauges - ionization gauge cross section ratio

Theoretical and experimental studies of the underlying processes and techniques of low pressure measurement Letter report, 1 Jul. 1967 - 31 May 1968

Ionization gage behavior in various gas mixtures and atmospheric composition

Vine Robots: Design, Teleoperation, and Deployment for Navigation and Exploration

A new class of continuum robots has recently been explored, characterized by tip extension, significant length change, and directional control. Here, we call this class of robots "vine robots," due to their similar behavior to plants with the growth habit of trailing. Due to their growth-based movement, vine robots are well suited for navigation and exploration in cluttered environments, but until now, they have not been deployed outside the lab. Portability of these robots and steerability at length scales relevant for navigation are key to field applications. In addition, intuitive human-in-the-loop teleoperation enables movement in unknown and dynamic environments. We present a vine robot system that is teleoperated using a custom designed flexible joystick and camera system, long enough for use in navigation tasks, and portable for use in the field. We report on deployment of this system in two scenarios: a soft robot navigation competition and exploration of an archaeological site. The competition course required movement over uneven terrain, past unstable obstacles, and through a small aperture. The archaeological site required movement over rocks and through horizontal and vertical turns. The robot tip successfully moved past the obstacles and through the tunnels, demonstrating the capability of vine robots to achieve navigation and exploration tasks in the field.Comment: IEEE Robotics and Automation Magazine, 2019. Video available at https://youtu.be/9NtXUL69g_

Spin-Peierls and Antiferromagnetic Phases in Cu{1-x}Zn{x}GeO{3}: A Neutron Scattering Study

Comprehensive neutron scattering studies were carried out on a series of high-quality single crystals of Cu_{1-x}Zn_xGeO_3. The Zn concentration, x, was determined for each sample using Electron Probe Micro-Analysis. The measured Zn concentrations were found to be 40-80% lower than the nominal values. Nevertheless the measured concentrations cover a wide range which enables a systematic study of the effects due to Zn-doping. We have confirmed the coexistence of spin-Peierls (SP) and antiferromagnetic (AF) orderings at low temperatures and the measured phase diagram is presented. Most surprisingly, long-range AF ordering occurs even in the lowest available Zn concentration, x=0.42%, which places important constraints on theoretical models of the AF-SP coexistence. Magnetic excitations are also examined in detail. The AF excitations are sharp at low energies and show no considerable broadening as x increases indicating that the AF ordering remains long ranged for x up to 4.7%. On the other hand, the SP phase exhibits increasing disorder as x increases, as shown from the broadening of the SP excitations as well as the dimer reflection peaks.Comment: 17 preprint style pages, 9 postscript files included. Submitted to Phys. Rev. B. Also available from http://insti.physics.sunysb.edu/~mmartin/pubs.htm

Using meta-patterns to construct patterns

International audienceThe pattern notion defines techniques allowing the existing knowledge reuse. Usually, the knowledge encapsulated in these patterns is stored in classic library repositories that quickly become overcrowded. To solve this problem, [1] proposes the use of process maps in order to organize and select them. But the completeness of the maps is a very important problem that has to be solved in order to offer a useful guidance to the method engineer. This paper proposes a guideline pattern construction technique guiding engineers when creating the maps

Business experience and start-up size: buying more lottery tickets next time around?

This paper explores the determinants of start-up size by focusing on a cohort of 6247 businesses that started trading in 2004, using a unique dataset on customer records at Barclays Bank. Quantile regressions show that prior business experience is significantly related with start-up size, as are a number of other variables such as age, education and bank account activity. Quantile treatment effects (QTE) estimates show similar results, with the effect of business experience on (log) start-up size being roughly constant across the quantiles. Prior personal business experience leads to an increase in expected start-up size of about 50%. Instrumental variable QTE estimates are even higher, although there are concerns about the validity of the instrument

Participatory risk management approaches for water governance: Insights from Australia and Bulgaria

Multiple decision makers and managers, competing interests and values, scarcity of resources, complex legislative requirements, and vast uncertainties about the future due to a more connected and rapidly changing world and the impacts of climate change, are just some of the issues that impact upon the capacity to carry out effective water planning and management. Throughout the world these issues are becoming increasingly difficult to handle, and there have been calls for more adapted approaches to aid the decision making processes required for water planning and management. Participatory risk management approaches appear appropriate to such situations as they can be designed to increase collaboration and manage conflict, explicit uncertainties, and structure complexity in more understandable forms. This paper will outline some insights and lessons learnt from the design and implementation of two different participatory risk management processes for water planning and management: a values-based method based on the Australian and New Zealand Standard for Risk Management for the development of the Lower Hawkesbury Estuary Management Plan in Australia; and a participatory modelling approach to manage the risks of living with floods and droughts in the Iskar basin in Bulgaria. Both processes were designed and implemented with the aid of researchers, local managers, government representatives at various levels of jurisdiction, community stakeholders and external legislative, scientific or engineering experts. The Australian process was an initiative driven and funded by the Hornsby Shire Council, a peri-urban municipality of Sydney. It consisted of three interactive stakeholder workshops with an average of 20 participants, held over a period of four months, as well as an external scientific and legislative review. The workshops focussed on establishing estuarine values, issues and current management practices; performing a risk assessment based on the stakeholder defined values (assets) and issues (risks); and formulating strategies to treat the highest prioritised risks as input to the estuary management "risk response" plan. The Bulgarian process in the region of Sofia formed part of the European Project "AquaStress", funded by the European Union, and was primarily driven from a research perspective. The participatory process was more elaborate in design than the Australian process with around 60 stakeholders divided into 6 groups taking part in a series of 15 workshops, individual interviews and evaluation exercises over a one year period. The process included cognitive mapping of the current management context and physical system, values, visions and preference elicitation for actions, strategy development and evaluation. Both cases provided rich insights into the value and constraints of participatory risk management approaches in different regulatory and political environments, as well as some important recurrent issues that organising teams of participatory approaches need to appreciate including: impacts of last minute process changes; how to deal with divergent objectives in a multi-institutional organising team; and the unintended ethical issues that can arise when working in "real-world" management situations. Increasing awareness of the value and potential issues associated with participatory risk management approaches should aid their adoption and the subsequent improvement of water planning and management around the world. (Résumé d'auteur

Kompetenznetz E-Learning Hessen

Mit dem Kompetenznetz e-learning-hessen.de vernetzen sich die hessischen Hochschulen mit Hilfe der Koordination und Unterstützung durch das httc und Förderung durch das Hessische Ministerium für Wissenschaft und Kunst rund um das Thema E-Learning. Dieser Beitrag beschreibt die Ziele des Netzwerks, dessen Maßnahmen und Elemente und die bisherigen Erfahrungen und seine Entwicklung seit dem Jahr 2000. Mit der abschließenden Bewertung werden Anhaltspunkte für eine erfolgreiche Vernetzung von Hochschulen und ein Ausblick auf die geplanten Aktivitäten des hessischen Netzwerkes in den nächsten Jahren gegeben. (DIPF/ Orig.