Cotton spinning to climbing gear: practical aspects of design evolution in Lancashire and the North West of England

This article looks at the role of path dependency in the design of outdoor clothing and equipment, from the perspective of changing and overlapping industrial clusters in Lancashire and Sheffield, from the 1960s. It demonstrates that, unlike the fashion market, design in mountaineering clothing and equipment was originally based heavily upon functionality and hence on user innovation. It shows that skills and knowledge which evolved during the industrial revolution, in both industrial areas, were vitally important to the development of internationally competitive mountaineering equipment firms. It was, however, the way in which these sources of knowledge were combined with sporting expertise that contributed to the design of innovative functional products. In addition, fundamental changes occurred in the relationship between manufacturers and their customers and these were vital to the success of this process, marking a departure from past practice

Rapid evaluation of ion thruster lifetime using optical emission spectroscopy

A major life-limiting phenomenon of electric thrusters is the sputter erosion of discharge chamber components. Thrusters for space propulsion are required to operate for extended periods of time, usually in excess of 10,000 hr. Lengthy and very costly life-tests in high-vacuum facilities have been required in the past to determine the erosion rates of thruster components. Alternative methods for determining erosion rates which can be performed in relatively short periods of time at considerably lower costs are studied. An attempt to relate optical emission intensity from an ion bombarded surface (screen grid) to the sputtering rate of that surface is made. The model used a kinetic steady-state (KSS) approach, balancing the rates of population and depopulation of ten low-lying excited states of the sputtered molybdenum atom (MoI) with those of the ground state to relate the spectral intensities of the various transitions of the MoI to the population densities. Once this is accomplished, the population density can be related to the sputtering rate of the target. Radiative and collisional modes of excitation and decay are considered. Since actual data has not been published for MoI excitation rate and decay constants, semiempirical equations are used. The calculated sputtering rate and intensity is compared to the measured intensity and sputtering rates of the 8 and 30 cm ion thrusters

Intention and motor representation in purposive action

Are there distinct roles for intention and motor representation in explaining the purposiveness of action? Standard accounts of action assign a role to intention but are silent on motor representation. The temptation is to suppose that nothing need be said here because motor representation is either only an enabling condition for purposive action or else merely a variety of intention. This paper provides reasons for resisting that temptation. Some motor representations, like intentions, coordinate actions in virtue of representing outcomes; but, unlike intentions, motor representations cannot feature as premises or conclusions in practical reasoning. This implies that motor representation has a distinctive role in explaining the purposiveness of action. It also gives rise to a problem: were the roles of intention and motor representation entirely independent, this would impair effective action. It is therefore necessary to explain how intentions interlock with motor representations. The solution, we argue, is to recognise that the contents of intentions can be partially determined by the contents of motor representations. Understanding this content-determining relation enables better understanding how intentions relate to actions

Groundwater seepage landscapes from distant and local sources in experiments and on Mars

© 2014 Author(s). Valleys with theater-shaped heads can form due to the seepage of groundwater and as a result of knickpoint (waterfall) erosion generated by overland flow. This ambiguity in the mechanism of formation hampers the interpretation of such valleys on Mars, particularly since there is limited knowledge of material properties. Moreover, the hydrological implications of a groundwater or surface water origin are important for our understanding of the evolution of surface features on Mars, and a quantification of valley morphologies at the landscape scale may provide diagnostic insights on the formative hydrological conditions. However, flow patterns and the resulting landscapes produced by different sources of groundwater are poorly understood. We aim to improve the understanding of the formation of entire valley landscapes through seepage processes from different groundwater sources that will provide a framework of landscape metrics for the interpretation of such systems. We study groundwater seepage from a distant source of groundwater and from infiltration of local precipitation in a series of sandbox experiments and combine our results with previous experiments and observations of the Martian surface. Key results are that groundwater flow piracy acts on valleys fed by a distant groundwater source and results in a sparsely dissected landscape of many small and a few large valleys. In contrast, valleys fed by a local groundwater source, i.e., nearby infiltration, result in a densely dissected landscape. In addition, valleys fed by a distant groundwater source grow towards that source, while valleys with a local source grow in a broad range of directions and have a strong tendency to bifurcate, particularly on flatter surfaces. We consider these results with respect to two Martian cases: Louros Valles shows properties of seepage by a local source of groundwater and Nirgal Vallis shows evidence of a distant source, which we interpret as groundwater flow from Tharsis

Nonlinear Dynamics of Capacitive Charging and Desalination by Porous Electrodes

The rapid and efficient exchange of ions between porous electrodes and aqueous solutions is important in many applications, such as electrical energy storage by super-capacitors, water desalination and purification by capacitive deionization (or desalination), and capacitive extraction of renewable energy from a salinity difference. Here, we present a unified mean-field theory for capacitive charging and desalination by ideally polarizable porous electrodes (without Faradaic reactions or specific adsorption of ions) in the limit of thin double layers (compared to typical pore dimensions). We illustrate the theory in the case of a dilute, symmetric, binary electrolyte using the Gouy-Chapman-Stern (GCS) model of the double layer, for which simple formulae are available for salt adsorption and capacitive charging of the diffuse part of the double layer. We solve the full GCS mean-field theory numerically for realistic parameters in capacitive deionization, and we derive reduced models for two limiting regimes with different time scales: (i) In the "super-capacitor regime" of small voltages and/or early times where the porous electrode acts like a transmission line, governed by a linear diffusion equation for the electrostatic potential, scaled to the RC time of a single pore. (ii) In the "desalination regime" of large voltages and long times, the porous electrode slowly adsorbs neutral salt, governed by coupled, nonlinear diffusion equations for the pore-averaged potential and salt concentration

The evolutionary state of short-period magnetic white dwarf binaries

We present phase-resolved spectroscopy of two new short-period low accretion rate magnetic binaries, SDSS J125044.42+154957.3 (Porb= 86 min) and SDSS J151415.65+074446.5 (Porb= 89 min). Both systems were previously identified as magnetic white dwarfs from the Zeeman splitting of the Balmer absorption lines in their optical spectra. Their spectral energy distributions exhibit a large near-infrared excess, which we interpret as a combination of cyclotron emission and possibly a late-type companion star. No absorption features from the companion are seen in our optical spectra. We derive the orbital periods from a narrow, variable Hα emission line which we show to originate on the companion star. The high radial velocity amplitude measured in both systems suggests a high orbital inclination, but we find no evidence for eclipses in our data. The two new systems resemble the polar EF Eri in its prolonged low state and also SDSS J121209.31+013627.7, a known magnetic white dwarf plus possible brown dwarf binary, which was also recovered by our method

Evidence of Low-Temperature Superparamagnetism in Mn3O_{3}O_{4}$ Nanoparticle Ensembles

Please refer to the abstract within the main body of the paper

Applications of active microwave imagery

The following topics were discussed in reference to active microwave applications: (1) Use of imaging radar to improve the data collection/analysis process; (2) Data collection tasks for radar that other systems will not perform; (3) Data reduction concepts; and (4) System and vehicle parameters: aircraft and spacecraft

Next Generation Differential GPS Architecture

The United States Coast Guard is engaged in a project to re-capitalize Reference Station (RS) and Integrity Monitor (IM) equipment used in the Nationwide Differential Global Position System (NDGPS). The Coast Guard in partnership with industry is developing a new software application to run on an open architecture platform as a replacement for legacy equipment. Present commercially available off-the-shelf Differential Global Positioning System (DGPS) RS and IM equipment lacks the open architecture required to support long term goals and future system improvements. The utility of the proposed new hardware architecture and software application is impressive - nearly every aspect of performance and supportability significantly exceeds that of the legacy architecture. The flexibility of the new hardware and software architectures complement each other to offer promising possibilities for the future. For example, the new hardware architecture uses Ethernet for internal and external site equipment communications. Each Local Area Network (LAN) will be equipped with a router and two 24 port switches. Various levels of password protection are provided to manage security both locally and remotely. While the new software application directly supports the legacy RS-232/422 interfaces to devices such as GPS receivers, a system design goal includes the ability to directly address each device from NCS. With the use of TCP/IP to RS-232/422 port server devices, the system can meet these forward reaching goals while supporting legacy equipment. New system capabilities include remote software management, remote hardware configuration management, and flexible options for management of licenses. The new configurable RS and IM architecture is a PCbased emulation of legacy reference station and integrity monitor equipment. It supports fluid growth and exploitation of new signals, formats, and technology as they become available, while remaining backward compatible with legacy architecture and user equipment. Examples of new capabilities include enhanced data management & anomaly analysis, universal On Change Reference Station Integrity Monitor (RSIM) message scheduling, improved satellite clock handling, additional observation interval modes, and Range Rate Correction monitoring in the IM. Engineering initiatives under development such as implementation of pre-broadcast integrity are also presented. This paper details challenges and goals that drove software and hardware design approaches destined to become the backbone of the Next Generation Differential GPS Architecture. Functional differences between legacy and next generation operation are explored. The new DGPS system architecture will allow the USCG radiobeacon system to continue to deliver and improve navigation and positioning services to our nation and its territories. Reprinted with permission from The Institute of Navigation (http://ion.org/) and The Proceedings of the 18th International Technical Meeting of the Satellite Division of The Institute of Navigation, (pp. 816-826). Fairfax, VA: The Institute of Navigation