Arc lamp power supply using a voltage multiplier

A power supply is provided for an arc discharge lamp which includes a relatively low voltage high current power supply section and a high voltage starter circuit. The low voltage section includes a transformer, rectifier, variable resistor and a bank of capacitors, while the starter circuit comprises several diodes and capacitors connected as a Cockcroft-Walton multiplier. The starting circuit is effectively bypassed when the lamp arc is established and serves to automatically provide a high starting voltage to re-strike the lamp arc if the arc is extinguished by a power interruption

The Influence of CrossFit Training on Running Mechanics

Introduction 40 million Americans run regularly.1 Contrary to many runner’s beliefs, increased strength may be beneficial while not adding body mass. An increase in strength in specific muscles may improve running gait and performance. 9,6 Strength training may also play an important role in preventing common overuse injuries in running 11,12 Depending on the style of strength training, it may also have an enhanced benefit on running economy.4,16 Participation in CrossFit is also widely popular, with an increase in participation of 923% in the past ten years.2 CrossFit is a type of strength training in which most movements performed utilize the hip to generate a majority of the power for successful completion.8 Muscles of the hip and knee are imperative during many CrossFit movements, but also during running. Purpose The purpose of this study is to investigate the influence that CrossFit training has on running mechanics. Methods 18 recreational runners between the ages of 18-65 were recruited in each of two groups: 9 runners that also participate in CrossFit 3 times per week, and 9 runners that do not do any strength training. Inclusion criteria included running at least 10 miles a week. Participants gave written consent and completed a demographic questionnaire and Physical Activity Readiness Questionnaire. Following consent, InBody (570, InBody USA, Cerritos, CA) bioelectric impedance body composition was collected. Participants then completed a 5-minute treadmill warm-up. Retro-reflective markers were placed bilaterally on the shoulders and hips and unilaterally on the leg and foot. Data collection was completed over ground along a 10-meter runway with three embedded force platforms (1000 Hz, AMTI Optima, Watertown, MA). Preferred running velocity was then determined. Participants performed two separate conditions; preferred running velocity (C1) and a set velocity of 3.5 m/s (C2). Trials were collected via three-dimensional motion capture system (200 Hz, Vicon, MX and Vantage, Oxfordshire, UK) and photoelectric timing gates. Eight successful trials were collected for each condition. Participants then performed strength testing of the hip and knee to determine peak torque using the isokinetic dynamometer (Biodex System 3, Biodex Medical Systems Shirley, NY) each consisting of one set of five reps at 120 °/s . Data Analysis Following collection, trials were individually processed using Vicon Nexus software (version 2.2.3, Oxfrodshire, UK). Trials were then exported to Visual 3D (version 5, Germantown, MD) and further processed. Statistics Kinematic and kinetic variables were analyzed with a 2x2 repeated measures ANOVA. Strength variables were analyzed with independent t-tests. Alpha level was set to 0.05. Results There was a significant difference between the CF group and the RO group in all of the strength measures, with the CF group having greater strength. For hip ROM, there were no significant differences between the groups, but there was a significant difference between the conditions. Discussion Although there were few differences between the two groups, the main finding of this study is that the CrossFit group was significantly stronger than the run-only group. This is of importance because it demonstrates that even though the CrossFit group was stronger, the running mechanics of the two groups were similar

Power saw

A power saw is disclosed for space or robotic operations with jaw members for clamping to a work piece by an operation of a lever arm. The saw assembly is slidably mounted on the jaw assembly and fed into the work piece by a hand operated feed screw. The saw assembly includes a motor and gear belt. A current sensing circuit provides a current signal which actuates colored lights to visually depict the load on the saw blade during the cutting operations

Gaming techniques and the product development process : commonalities and cross-applications

The use of computer-based tools is now firmly embedded within the product development process, providing a wide range of uses from visualisation to analysis. However, the specialisation required to make effective use of these tools has led to the compartmentalisation of expertise in design teams, resulting in communication problems between individual members. This paper therefore considers how computer gaming techniques and strategies could be used to enhance communication and group design activities throughout the product design process

Instabilities and soot formation in spherically expanding, high pressure, rich, iso-octane-air flames

Flame instabilities, cellular structures and soot formed in high pressure, rich, spherically expanding iso-octane-air flames have been studied experimentally using high speed Schlieren cinematography, OH fluorescence, Mie scattering and laser induced incandescence. Cellular structures with two wavelength ranges developed on the flame surface. The larger wavelength cellular structure was produced by the Landau-Darrieus hydrodynamic instability, while the short wavelength cellular structure was produced by the thermal-diffusive instability. Large negative curvature in the short wavelength cusps caused local flame quenching and fracture of the flame surface. In rich flames with equivalence ratio φ > 1.8, soot was formed in a honeycomb-like structure behind flame cracks associated with the large wavelength cellular structure induced by the hydrodynamic instability. The formation of soot precursors through low temperature pyrolysis was suggested as a suitable mechanism for the initiation of soot formation behind the large wavelength flame cracks

Scientific publications and presentations relating to planetary quarantine. Volume 5: The 1975 supplement

Documents pertaining to planetary quarantine are listed. An author index is given along with a listing of books and journals containing related material

Conformational Control of Exciton-Polariton Physics in Metal - Poly(9,9-dioctylfluorene) - Metal Cavities

Control is exerted over the exciton-polariton physics in metal - Poly(9,9-dioctyl fluorene) - metal microcavities via conformational changes to the polymer backbone. Using thin-film samples containing increasing fractions of $\beta$-phase chain segments, a systematic study is reported for the mode characteristics and resulting light emission properties of cavities containing two distinct exciton sub-populations within the same semiconductor. Ultrastrong coupling for disordered glassy-phase excitons is observed from angle-resolved reflectivity measurements, with Rabi splitting energies in excess of 1.05 eV (more than 30% of the exciton transition energy) for both TE- and TM-polarized light. A splitting of the lower polariton branch is then induced via introduction of $\beta$-phase excitons and increases with their growing fraction. In all cases, the photoluminescence emanates from the lowermost polariton branch, allowing conformational control to be exerted over the emission energy and its angular variation. Dispersion-free cavities with highly saturated blue-violet emission are thus enabled. Experimental results are discussed in terms of the full Hopfield Hamiltonian generalized to the case of two exciton oscillators. The importance of taking account of the molecular characteristics of the semiconductor for an accurate description of its strong coupling behaviour is directly considered, in specific relation to the role of the vibronic structure

Basis Token Consistency: A Practical Mechanism for Strong Web Cache Consistency

With web caching and cache-related services like CDNs and edge services playing an increasingly significant role in the modern internet, the problem of the weak consistency and coherence provisions in current web protocols is becoming increasingly significant and drawing the attention of the standards community [LCD01]. Toward this end, we present definitions of consistency and coherence for web-like environments, that is, distributed client-server information systems where the semantics of interactions with resource are more general than the read/write operations found in memory hierarchies and distributed file systems. We then present a brief review of proposed mechanisms which strengthen the consistency of caches in the web, focusing upon their conceptual contributions and their weaknesses in real-world practice. These insights motivate a new mechanism, which we call "Basis Token Consistency" or BTC; when implemented at the server, this mechanism allows any client (independent of the presence and conformity of any intermediaries) to maintain a self-consistent view of the server's state. This is accomplished by annotating responses with additional per-resource application information which allows client caches to recognize the obsolescence of currently cached entities and identify responses from other caches which are already stale in light of what has already been seen. The mechanism requires no deviation from the existing client-server communication model, and does not require servers to maintain any additional per-client state. We discuss how our mechanism could be integrated into a fragment-assembling Content Management System (CMS), and present a simulation-driven performance comparison between the BTC algorithm and the use of the Time-To-Live (TTL) heuristic.National Science Foundation (ANI-9986397, ANI-0095988

Blending arts and sciences: gimmick or necessity?

The shortage of degree qualified engineers in the UK is well documented. On the other hand the surplus of art and design graduates is growing. Whilst acknowledging the shortage in engineering graduates, there is also the need to recognise the breadth and increased skill level that engineering graduates require. Is it therefore possible to convert some of the excess graduates in art and design to careers in design and development engineering? The success of many engineering businesses depends not only on technical excellence but also on understanding of the market needs and the speed of response to this demand. To make this task even harder, businesses are also expected to compete in markets that are open to global competition and are also faced with much more sophisticated consumers. Businesses that are engaged in the manufacture of goods now require a new breed of engineer. These are not only technically competent individuals, but also possess what is known as “soft” or “creative” skills traditionally found in graduates of art and design disciplines. This paper details an innovative curriculum model offered at postgraduate level to address the 21 st century needs of engineering businesses. The paper also details rigorous recruitment tools developed and used for selecting students exclusively from the art and design discipline