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1. Design and optimization of millimeter-scale electroadhesive grippers

Author

Jaquith Jeffrey Frederick, Hod Lipson, Joni Mici, and Jared D West

Subjects
Electroadhesion, Materials science, Acoustics and Ultrasonics, Scale (ratio), Grippers, business.industry, Millimeter, Aerospace engineering, Condensed Matter Physics, business, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials
Published
2020

2. Spectral response of chlorophyll content during leaf senescence in European beech trees

Author

Alistair S. Jump, Martin D. West, Daniel N.M. Donoghue, and Peter J. Morley

Subjects
Senescence, Atmospheric Science, Chlorophyll content, biology, Phenology, Reflectance spectroscopy, Spectral response, Red edge, Geology, biology.organism_classification, Agricultural and Biological Sciences (miscellaneous), Pigment, visual_art, Botany, visual_art.visual_art_medium, Environmental science, Beech, Earth-Surface Processes, General Environmental Science, Food Science
Abstract

Leaf chlorophyll content declines in response to environmental stressors and during natural senescence periods. Assessments of forest health and vulnerability to stressors require repeated measurements of forest health to quantify declines in chlorophyll content and identify shifts in the timing of key phenological events. Although remote sensing is ideal for making reliable and repeated forest health measurements to assess forest response to environmental change over large areas, reliable warning systems for monitoring plant health are lacking. To facilitate the estimation of chlorophyll content from remotely sensed data, we define the relationships between leaf chlorophyll content and spectral indices in European beech trees (Fagus sylvatica). We show that hand-held chlorophyll meters can be calibrated to leaf chlorophyll content providing a non-destructive method for rapid assessment of leaf chlorophyll content in the field. Spectral indices based on the red edge spectral region have the strongest relationship with leaf chlorophyll content (mND705 R 2 = 0.95, RMSE = 4.70; mSR705 R 2 = 0.95, RMSE = 4.71) but are unable to discriminate between photosynthetically active leaves and inactive leaves. Alternative spectral indices can discriminate effectively between photosynthetically active and inactive leaves but are less well suited to defining declines in chlorophyll content. These findings reveal key research needs for improving the use of remote sensing data for forest health assessments.

Published
2020

3. Overview of the EUROfusion Tokamak Exploitation programme in support of ITER and DEMO

Author

E. Joffrin, M. Wischmeier, M. Baruzzo, A. Hakola, A. Kappatou, D. Keeling, B. Labit, E. Tsitrone, N. Vianello, the ASDEX Upgrade Team, JET Contributors, the MAST-U Team, the TCV Team, the WEST Team, the EUROfusion Tokamak Exploitation Team:, D. Abate, J. Adamek, M. Agostini, C. Albert, F.C.P. Albert Devasagayam, S. Aleiferis, E. Alessi, J. Alhage, S. Allan, J. Allcock, M. Alonzo, G. Anastasiou, E. Andersson Sunden, C. Angioni, Y. Anquetin, L. Appel, G.M. Apruzzese, M. Ariola, C. Arnas, J.F. Artaud, W. Arter, O. Asztalos, L. Aucone, M.H. Aumeunier, F. Auriemma, J. Ayllon, E. Aymerich, A. Baciero, F. Bagnato, L. Bähner, F. Bairaktaris, P. Balázs, L. Balbinot, I. Balboa, M. Balden, A. Balestri, M. Baquero Ruiz, T. Barberis, C. Barcellona, O. Bardsley, S. Benkadda, T. Bensadon, E. Bernard, M. Bernert, H. Betar, R. Bianchetti Morales, J. Bielecki, R. Bilato, P. Bilkova, W. Bin, G. Birkenmeier, R. Bisson, P. Blanchard, A. Bleasdale, V. Bobkov, A. Boboc, A. Bock, K. Bogar, P. Bohm, T. Bolzonella, F. Bombarda, N. Bonanomi, L. Boncagni, D. Bonfiglio, R. Bonifetto, M. Bonotto, D. Borodin, I. Borodkina, T.O.S.J. Bosman, C. Bourdelle, C. Bowman, S. Brezinsek, D. Brida, F. Brochard, R. Brunet, D. Brunetti, V. Bruno, R. Buchholz, J. Buermans, H. Bufferand, P. Buratti, A. Burckhart, J. Cai, R. Calado, J. Caloud, S. Cancelli, F. Cani, B. Cannas, M. Cappelli, S. Carcangiu, A. Cardinali, S. Carli, D. Carnevale, M. Carole, M. Carpita, D. Carralero, F. Caruggi, I.S. Carvalho, I. Casiraghi, A. Casolari, F.J. Casson, C. Castaldo, A. Cathey, F. Causa, J. Cavalier, M. Cavedon, J. Cazabonne, M. Cecconello, L. Ceelen, A. Celora, J. Cerovsky, C.D. Challis, R. Chandra, A. Chankin, B. Chapman, H. Chen, M. Chernyshova, A.G. Chiariello, P. Chmielewski, A. Chomiczewska, C. Cianfarani, G. Ciraolo, J. Citrin, F. Clairet, S. Coda, R. Coelho, J.W. Coenen, I.H. Coffey, C. Colandrea, L. Colas, S. Conroy, C. Contre, N.J. Conway, L. Cordaro, Y. Corre, D. Costa, S. Costea, D. Coster, X. Courtois, C. Cowley, T. Craciunescu, G. Croci, A.M. Croitoru, K. Crombe, D.J. Cruz Zabala, G. Cseh, T. Czarski, A. Da Ros, A. Dal Molin, M. Dalla Rosa, Y. Damizia, O. D’Arcangelo, P. David, M. De Angeli, E. De la Cal, E. De La Luna, G. De Tommasi, J. Decker, R. Dejarnac, D. Del Sarto, G. Derks, C. Desgranges, P. Devynck, S. Di Genova, L.E. di Grazia, A. Di Siena, M. Dicorato, M. Diez, M. Dimitrova, T. Dittmar, L. Dittrich, J.J. Domínguez Palacios Durán, P. Donnel, D. Douai, S. Dowson, S. Doyle, M. Dreval, P. Drews, L. Dubus, R. Dumont, D. Dunai, M. Dunne, A. Durif, F. Durodie, G. Durr Legoupil Nicoud, B. Duval, R. Dux, T. Eich, A. Ekedahl, S. Elmore, G. Ericsson, J. Eriksson, B. Eriksson, F. Eriksson, S. Ertmer, A. Escarguel, B. Esposito, T. Estrada, E. Fable, M. Faitsch, N. Fakhrayi Mofrad, A. Fanni, T. Farley, M. Farník, N. Fedorczak, F. Felici, X. Feng, J. Ferreira, D. Ferreira, N. Ferron, O. Fevrier, O. Ficker, A.R. Field, A. Figueiredo, N. Fil, D. Fiorucci, M. Firdaouss, R. Fischer, M. Fitzgerald, M. Flebbe, M. Fontana, J. Fontdecaba Climent, A. Frank, E. Fransson, L. Frassinetti, D. Frigione, S. Futatani, R. Futtersack, S. Gabriellini, D. Gadariya, D. Galassi, K. Galazka, J. Galdon, S. Galeani, D. Gallart, A. Gallo, C. Galperti, M. Gambrioli, S. Garavaglia, J. Garcia, M. Garcia Munoz, J. Gardarein, L. Garzotti, J. Gaspar, R. Gatto, P. Gaudio, M. Gelfusa, J. Gerardin, S.N. Gerasimov, R. Gerru Miguelanez, G. Gervasini, Z. Ghani, F.M. Ghezzi, G. Ghillardi, L. Giannone, S. Gibson, L. Gil, A. Gillgren, E. Giovannozzi, C. Giroud, G. Giruzzi, T. Gleiter, M. Gobbin, V. Goloborodko, A. González Ganzábal, T. Goodman, V. Gopakumar, G. Gorini, T. Görler, S. Gorno, G. Granucci, D. Greenhouse, G. Grenfell, M. Griener, W. Gromelski, M. Groth, O. Grover, M. Gruca, A. Gude, C. Guillemaut, R. Guirlet, J. Gunn, T. Gyergyek, L. Hagg, J. Hall, C.J. Ham, M. Hamed, T. Happel, G. Harrer, J. Harrison, D. Harting, N.C. Hawkes, P. Heinrich, S. Henderson, P. Hennequin, R. Henriques, S. Heuraux, J. Hidalgo Salaverri, J. Hillairet, J.C. Hillesheim, A. Hjalmarsson, A. Ho, J. Hobirk, E. Hodille, M. Hölzl, M. Hoppe, J. Horacek, N. Horsten, L. Horvath, M. Houry, K. Hromasova, J. Huang, Z. Huang, A. Huber, E. Huett, P. Huynh, A. Iantchenko, M. Imrisek, P. Innocente, C. Ionita Schrittwieser, H. Isliker, P. Ivanova, I. Ivanova Stanik, M. Jablczynska, S. Jachmich, A.S. Jacobsen, P. Jacquet, A. Jansen van Vuuren, A. Jardin, H. Järleblad, A. Järvinen, F. Jaulmes, T. Jensen, I. Jepu, S. Jessica, T. Johnson, A. Juven, J. Kalis, J. Karhunen, R. Karimov, A.N. Karpushov, S. Kasilov, Y. Kazakov, P.V. Kazantzidis, W. Kernbichler, HT. Kim, D.B. King, V.G. Kiptily, A. Kirjasuo, K.K. Kirov, A. Kirschner, A. Kit, T. Kiviniemi, F. Kjær, E. Klinkby, A. Knieps, U. Knoche, M. Kochan, F. Köchl, G. Kocsis, J.T.W. Koenders, L. Kogan, Y. Kolesnichenko, Y. Kominis, M. Komm, M. Kong, B. Kool, S.B. Korsholm, D. Kos, M. Koubiti, J. Kovacic, Y. Kovtun, E. Kowalska Strzeciwilk, K. Koziol, M. Kozulia, A. Krämer Flecken, A. Kreter, K. Krieger, U. Kruezi, O. Krutkin, O. Kudlacek, U. Kumar, H. Kumpulainen, M.H. Kushoro, R. Kwiatkowski, M. La Matina, M. Lacquaniti, L. Laguardia, P. Lainer, P. Lang, M. Larsen, E. Laszynska, K.D. Lawson, A. Lazaros, E. Lazzaro, M.Y.K. Lee, S. Leerink, M. Lehnen, M. Lennholm, E. Lerche, Y. Liang, A. Lier, J. Likonen, O. Linder, B. Lipschultz, A. Listopad, X. Litaudon, E. Litherland Smith, D. Liuzza, T. Loarer, P.J. Lomas, J. Lombardo, N. Lonigro, R. Lorenzini, C. Lowry, T. Luda di Cortemiglia, A. Ludvig Osipov, T. Lunt, V. Lutsenko, E. Macusova, R. Mäenpää, P. Maget, C.F. Maggi, J. Mailloux, S. Makarov, K. Malinowski, P. Manas, A. Mancini, D. Mancini, P. Mantica, M. Mantsinen, J. Manyer, M. Maraschek, G. Marceca, G. Marcer, C. Marchetto, S. Marchioni, A. Mariani, M. Marin, M. Markl, T. Markovic, D. Marocco, S. Marsden, L. Martellucci, P. Martin, C. Martin, F. Martinelli, L. Martinelli, J.R. Martin Solis, R. Martone, M. Maslov, R. Masocco, M. Mattei, G.F. Matthews, D. Matveev, E. Matveeva, M.L. Mayoral, D. Mazon, S. Mazzi, C. Mazzotta, G. McArdle, R. McDermott, K. McKay, A.G. Meigs, C. Meineri, A. Mele, V. Menkovski, S. Menmuir, A. Merle, H. Meyer, K. Mikszuta Michalik, D. Milanesio, F. Militello, A. Milocco, I.G. Miron, J. Mitchell, R. Mitteau, V. Mitterauer, J. Mlynar, V. Moiseenko, P. Molna, F. Mombelli, C. Monti, A. Montisci, J. Morales, P. Moreau, J.M. Moret, A. Moro, D. Moulton, P. Mulholland, M. Muraglia, A. Murari, A. Muraro, P. Muscente, D. Mykytchuk, F. Nabais, Y. Nakeva, F. Napoli, E. Nardon, M.F. Nave, R.D. Nem, A. Nielsen, S.K. Nielsen, M. Nocente, R. Nouailletas, S. Nowak, H. Nyström, R. Ochoukov, N. Offeddu, S. Olasz, C. Olde, F. Oliva, D. Oliveira, H.J.C. Oliver, P. Ollus, J. Ongena, F.P. Orsitto, N. Osborne, R. Otin, P. Oyola Dominguez, D.I. Palade, S. Palomba, O. Pan, N. Panadero, E. Panontin, A. Papadopoulos, P. Papagiannis, G. Papp, V.V. Parail, C. Pardanaud, J. Parisi, A. Parrott, K. Paschalidis, M. Passoni, F. Pastore, A. Patel, B. Patel, A. Pau, G. Pautasso, R. Pavlichenko, E. Pawelec, B. Pegourie, G. Pelka, E. Peluso, A. Perek, E. Perelli Cippo, C. Perez Von Thun, P. Petersson, G. Petravich, Y. Peysson, V. Piergotti, L. Pigatto, C. Piron, L. Piron, A. Pironti, F. Pisano, U. Plank, B. Ploeckl, V. Plyusnin, A. Podolnik, Y. Poels, G. Pokol, J. Poley, G. Por, M. Poradzinski, F. Porcelli, L. Porte, C. Possieri, A. Poulsen, I. Predebon, G. Pucella, M. Pueschel, P. Puglia, O. Putignano, T. Pütterich, V. Quadri, A. Quercia, M. Rabinski, L. Radovanovic, R. Ragona, H. Raj, M. Rasinski, J. Rasmussen, G. Ratta, S. Ratynskaia, R. Rayaprolu, M. Rebai, A. Redl, D. Rees, D. Refy, M. Reich, H. Reimerdes, B.C.G. Reman, O. Renders, C. Reux, D. Ricci, M. Richou, S. Rienacker, D. Rigamonti, F. Rigollet, F.G. Rimini, D. Ripamonti, N. Rispoli, N. Rivals, J.F. Rivero Rodriguez, C. Roach, G. Rocchi, S. Rode, P. Rodrigues, J. Romazanov, C.F. Romero Madrid, J. Rosato, R. Rossi, G. Rubino, J. Rueda Rueda, J. Ruiz Ruiz, P. Ryan, D. Ryan, S. Saarelma, R. Sabot, M. Salewski, A. Salmi, L. Sanchis, A. Sand, J. Santos, K. Särkimäki, M. Sassano, O. Sauter, G. Schettini, S. Schmuck, P. Schneider, N. Schoonheere, R. Schramm, R. Schrittwieser, C. Schuster, N. Schwarz, F. Sciortino, M. Scotto D’Abusco, S. Scully, A. Selce, L. Senni, M. Senstius, G. Sergienko, S.E. Sharapov, R. Sharma, A. Shaw, U. Sheikh, G. Sias, B. Sieglin, S.A. Silburn, C. Silva, A. Silva, D. Silvagni, B. Simmendefeldt Schmidt, L. Simons, J. Simpson, L. Singh, S. Sipilä, Y. Siusko, S. Smith, A. Snicker, E.R. Solano, V. Solokha, M. Sos, C. Sozzi, F. Spineanu, G. Spizzo, M. Spolaore, L. Spolladore, C. Srinivasan, A. Stagni, Z. Stancar, G. Stankunas, J. Stober, P. Strand, C.I. Stuart, F. Subba, G.Y. Sun, H.J. Sun, W. Suttrop, J. Svoboda, T. Szepesi, G. Szepesi, B. Tal, T. Tala, P. Tamain, G. Tardini, M. Tardocchi, D. Taylor, G. Telesca, A. Tenaglia, A. Terra, D. Terranova, D. Testa, C. Theiler, E. Tholerus, B. Thomas, E. Thoren, A. Thornton, A. Thrysoe, Q. TICHIT, W. Tierens, A. Titarenko, P. Tolias, E. Tomasina, M. Tomes, E. Tonello, A. Tookey, M. Toscano Jiménez, C. Tsironis, C. Tsui, A. Tykhyy, M. Ugoletti, M. Usoltseva, D.F. Valcarcel, A. Valentini, M. Valisa, M. Vallar, M. Valovic, SI. Valvis, M. van Berkel, D. Van Eester, S. Van Mulders, M. van Rossem, R. Vann, B. Vanovac, J. Varela Rodriguez, J. Varje, S. Vartanian, M. Vecsei, L. Velarde Gallardo, M. Veranda, T. Verdier, G. Verdoolaege, K. Verhaegh, L. Vermare, G. Verona Rinati, J. Vicente, E. Viezzer, L. Vignitchouk, F. Villone, B. Vincent, P. Vincenzi, M.O. Vlad, G. Vogel, I. Voitsekhovitch, I. Voldiner, P. Vondracek, N.M.T. VU, T. Vuoriheimo, C. Wade, E. Wang, T. Wauters, M. Weiland, H. Weisen, N. Wendler, D. Weston, A. Widdowson, S. Wiesen, M. Wiesenberger, T. Wijkamp, M. Willensdorfer, T. Wilson, A. Wojenski, C. Wuethrich, I. Wyss, L. Xiang, S. Xu, D. Yadykin, Y. Yakovenko, H. Yang, V. Yanovskiy, R. Yi, B. Zaar, G. Zadvitskiy, L. Zakharov, P. Zanca, D. Zarzoso, Y. Zayachuk, J. Zebrowski, M. Zerbini, P. Zestanakis, C. F. B. Zimmermann, M. Zlobinski, A. Zohar, V.K. Zotta, X. Zou, M. Zuin, M. Zurita, and I. Zychor

Subjects
JET, ASDEX Upgrade, MAST-U, TCV, WEST, Tokamak Exploitation Task Force, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Within the 9th European Framework programme, since 2021 EUROfusion is operating five tokamaks under the auspices of a single Task Force called ‘Tokamak Exploitation’. The goal is to benefit from the complementary capabilities of each machine in a coordinated way and help in developing a scientific output scalable to future largre machines. The programme of this Task Force ensures that ASDEX Upgrade, MAST-U, TCV, WEST and JET (since 2022) work together to achieve the objectives of Missions 1 and 2 of the EUROfusion Roadmap: i) demonstrate plasma scenarios that increase the success margin of ITER and satisfy the requirements of DEMO and, ii) demonstrate an integrated approach that can handle the large power leaving ITER and DEMO plasmas. The Tokamak Exploitation task force has therefore organized experiments on these two missions with the goal to strengthen the physics and operational basis for the ITER baseline scenario and for exploiting the recent plasma exhaust enhancements in all four devices (PEX: Plasma EXhaust) for exploring the solution for handling heat and particle exhaust in ITER and develop the conceptual solutions for DEMO. The ITER Baseline scenario has been developed in a similar way in ASDEX Upgrade, TCV and JET. Key risks for ITER such as disruptions and run-aways have been also investigated in TCV, ASDEX Upgrade and JET. Experiments have explored successfully different divertor configurations (standard, super-X, snowflakes) in MAST-U and TCV and studied tungsten melting in WEST and ASDEX Upgrade. The input from the smaller devices to JET has also been proven successful to set-up novel control schemes on disruption avoidance and detachment.

Published
2024
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4. High density mode in xenon produced by a Helicon Double Layer Thruster

Author

Roderick Boswell, Michael D. West, and Christine Charles

Subjects
Acoustics and Ultrasonics, Chemistry, RF power amplifier, chemistry.chemical_element, Plasma, Condensed Matter Physics, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, symbols.namesake, Helicon, Xenon, symbols, Electron temperature, Langmuir probe, Plasma diagnostics, Radio frequency, Atomic physics
Abstract

A high density 'blue' mode has been observed when operating the Helicon Double Layer Thruster (HDLT) with xenon. Using a Langmuir probe and a retarding field energy analyser (RFEA), the plasma source and exhaust have been characterized at various radio frequency (RF) powers and operating pressures. When operating at low RF powers, the HDLT prototype is shown to be in a capacitively coupled mode. As the RF power is increased, a discrete mode transition occurs over a small RF power range (at about 625 W at 0.45 mTorr) and the plasma inside the source increases in density significantly and changes to a bright white/blue colour. This high density mode exhibits hysteresis, and radial measurements inside the source reveal a centrally peaked profile that is indicative of a helicon wave-sustained discharge. The quality, or Q, factor of the matching box is determined as a function of RF power and is shown to decrease in the high density mode, consistent with the increase in plasma density observed. The xenon exhaust of the HDLT prototype is investigated axially with the Langmuir probe and the RFEA and is shown to follow a Boltzmann expansion with an electron temperature of about 6 eV.

Published
2009

5. Investigation of the -Rays from Polonium

Author

R. A. Allen, D West, M. A. Grace, and H. Halban

Subjects
Nuclear physics, Nuclear reaction, Internal conversion, Decay scheme, chemistry, Branching fraction, chemistry.chemical_element, Pharmacology (medical), Alpha decay, Radiation, Polonium, Line (formation)
Abstract

A method of standardizing polonium sources by measurement of the number of γ-rays is described. The hard γ-radiation of 0.773 MeV. energy emitted in the decay of 210Po has been found to have an intensity of 1.8±0.14 × 10-5 quanta per α-particle The internal conversion of this line to the extent of 6.7±1.7% gives rise to K X-radiation of lead. No other soft radiation was detected. The decay scheme of polonium is discussed.

Published
1951

6. On the forces acting on drops in an electric field

Author

Gilbert D West

Subjects
Protein filament, Optics, business.industry, Chemistry, Drop (liquid), Electric field, Line of force, Electricity, Dielectric, Electrolyte, Mechanics, business, Electrical conductor
Abstract

If whilst a drop of electrolyte is falling in distilled water, a horizontal electric field be established, the drop rapidly spreads out into a filament parallel to the lines of force. An explanation of this phenomenon is given on the basis of the charge at the boundary between conductors that necessarily accompanies the transport of electricity. Experiments with dielectrics and with drops that contract instead of expand are described, and the paper is illustrated with photographs.

Published
1932

7. Mesonic atoms

Author

D West

Subjects
General Physics and Astronomy
Published
1958

9. On Theories of Thermal Transpiration

Author

Gilbert D West

Subjects
Thermal transpiration, General Engineering, General Earth and Planetary Sciences, Environmental science, Atmospheric sciences, General Environmental Science
Abstract

n/a

Published
1918

10. A mechanical wave model illustrating acoustic and electrical phenomena

Author

Gilbert D West

Subjects
Engineering, Filter (large eddy simulation), Series (mathematics), Rocker arm, business.industry, Bar (music), Electrical engineering, Range (statistics), Mechanics, Simple harmonic motion, business, Mechanical wave, Electrical phenomena
Abstract

A mechanical model is described which illustrates a band-pass filter. The model consists of a series of equal masses suspended on equal lengths of straightened watch-spring from a rigid bar. Through holes bored in the masses, which are equally spaced, is threaded a piece of elastic. One end is fixed, and the other can move with a simple harmonic motion, communicated by means of a rocker arm attached to a small motor. Wave-transmission along the system takes place only if the frequency falls within a certain range. Very high and very low frequencies are not transmitted. The theory of the model is discussed, and various analogies to physical phenomena are pointed out.

Published
1934

11. Circulations Occurring in Acoustic Phenomena

Author

G D West

Subjects
Optics, Circulation (fluid dynamics), Geography, High magnification, Salient, business.industry, General Medicine, Mechanics, business, Ellipse, Hydrodynamic flow
Abstract

An investigation is made, by means of smoke particles, of the movements of the air in the neighbourhood of a vibrating reed At very low frequencies, the paths of the particles exhibit a pattern which, at first sight, resembles the lines of hydrodynamic flow. A more careful examination at sufficiently high magnification shows, however, that the particles do not move along the hydrodynamic lines but trace cut small ellipses. In addition, a mass circulation of the particles is superimposed on the above motion. At low frequencies this circulation is feeble, but with increasing frequency it strengthens and soon becomes the salient feature. Eventually yet another circulation is superimposed. It is shown how this work connects up with that of other observers, and emphasis is placed on the common occurrence, in many acoustic phenomena, of circulatory motion in association with vibratory motion

Published
1951

12. On the Forces Acting on Heated Metal Foil Surfaces in Rarefied Gases

Author

Gilbert D West

Subjects
Convection, Chemistry, General Engineering, Enclosure, Thermodynamics, STRIPS, Mechanics, law.invention, Metal foil, law, Thermal transpiration, General Earth and Planetary Sciences, Thin metal, Absolute zero, FOIL method, General Environmental Science
Abstract

The present Paper arises out of two previous Papers by the author on the pressure of light ("Proc." Phys. Soc., XXV., p. 324, 1913, and XXVIII., p. 259, 1916), and consists of an experimental investigation of the nature of certain peculiar movements of strips of thin metal foil surrounded by rarefied gases, and exposed to radiation. The experiments deal chiefly with phenomena at gas pressures below 1 cm. of mercury, and it is shown that the apparently diverse results obtained can be connected by a theory based on the work of a previous Paper ("Proc." Phys. Soc., XXXI., p. 278, 1919). The author concludes that, at the highest rarefactions, the pressures on the strips arise from the fact that, if differences of temperature exist in an enclosure, the pressure of the gas is not uniform, but varies approximately as the square root of the latter's absolute temperature. The simple conditions that exist at low gas pressures are complicated, at the higher pressures, by gas currents which differ fundamentally from convection currents, but which are closely connected with the phenomena of thermal transpiration.

Published
1919

13. The Detection of Mesic X-rays with Pressurized Proportional Counters using Cosmic Ray -Mesons stopped in Carbon

Author

D West, R Batchelor, and E F Bradley

Subjects
Physics, Nuclear physics, Xenon, Muon, chemistry, Meson, Aluminium, Scintillation counter, X-ray detector, chemistry.chemical_element, Pharmacology (medical), Cosmic ray, Carbon
Abstract

The advantages of proportional counters over scintillation counters in the study of mesic x-rays from light elements are pointed out. A preliminary investigation is described in which mesic x-rays from carbon are detected with proportional counters. Aluminium counters filled to a pressure of seven atmospheres of xenon were used.

Published
1955

14. Experiments on Thermal Transpiration Currents

Author

Gilbert D West

Subjects
Convection, Range (particle radiation), business.industry, Chemistry, General Engineering, Mechanics, Gravitation, Temperature gradient, Optics, Drag, Thermal transpiration, Perpendicular, General Earth and Planetary Sciences, Astrophysics::Earth and Planetary Astrophysics, business, FOIL method, General Environmental Science
Abstract

This Paper is an attempt to demonstrate the actual existence of thermal transpiration currents. Theoretical considerations are first introduced to show that if a radial temperature gradient be maintained over a disc, so that the centre is the hottest part, thermal transpiration currents sweep radially inwards over the surface of the disc, and discharge themselves more or less radially outwards in the upper regions. To detect these currents a narrow strip of foil is used which is placed perpendicular to the disc, and to one side of the hot region. When at a considerable perpendicullar distance from the disc, and when the gas pressure is sufficiently low to eliminate convection currents, the deflections of the strip of foil are always away from the hot region. When, however, the strip is placed very close to the disc, its deflections over a certain range of gas pressure are towards the hot region. These facts are explained by the tendency of the thermal transpiration currents to drag the strip with them. The Paper emphasises one of the essential differences between thermal transpiration currents and convection currents - namely, that while the latter clearly depend on gravitation, the former do not. Further emphasis is laid on the differences between the conditions of molar and molecular equilibrium.

Published
1920

15. Further Measurements of the Ionization by Energetic Cosmic-Ray -Mesons

Author

D. West, E. Nageotte, J. Becker, B T Price, P. Chanson, and P. Treille

Subjects
Momentum, Physics, Neon, Muon, Theory of relativity, Meson, chemistry, Ionization, chemistry.chemical_element, Pharmacology (medical), Cosmic ray, Atomic physics
Abstract

The most probable specific ionization of energetic ?-mesons has been measured as a function of momentum, using proportional counters filled with a neonmethane mixture. The results confirm previous measurements, and are in good agreement with the theoretically predicted increase of specific ionization at high momenta.

Published
1953

18. An interferometer for sound waves

Author

Gilbert D West

Subjects
Physics, Silence, geography, Interferometry, Optics, geography.geographical_feature_category, Cylindrical tube, business.industry, Acoustics, General Medicine, business, Sound wave, Sound (geography)
Abstract

A source of sound is placed within a cylindrical tube closed at one end. Two sets of waves issue from the open end - one directly, and one by reflexion from the closed end. The two sets can be superposed so as to reinforce or to interfere destructively with each other, and thus to produce maximum sound or silence. The movements of the source necessary to effect these changes enable a determination of the wave-length to be made.

Published
1929

19. Soft Radiations from239Pu

Author

D West and J K Dawson

Subjects
Materials science, chemistry, Radiochemistry, chemistry.chemical_element, Pharmacology (medical), Uranium, Plutonium-239
Published
1951

22. Methods, analysis, and the treatment of systematic errors for the electron electric dipole moment search in thorium monoxide.

Author

J Baron, W C Campbell, D DeMille, J M Doyle, G Gabrielse, Y V Gurevich, P W Hess, N R Hutzler, E Kirilov, I Kozyryev, B R O’Leary, C D Panda, M F Parsons, B Spaun, A C Vutha, A D West, E P West, and ACME Collaboration

Subjects
ELECTRIC dipole moments, MEASUREMENT errors, THORIUM compounds, STANDARD model (Nuclear physics), CPT theorem
Abstract

We recently set a new limit on the electric dipole moment of the electron (eEDM) (J Baron et al and ACME collaboration 2014 Science343 269–272), which represented an order-of-magnitude improvement on the previous limit and placed more stringent constraints on many charge-parity-violating extensions to the standard model. In this paper we discuss the measurement in detail. The experimental method and associated apparatus are described, together with the techniques used to isolate the eEDM signal. In particular, we detail the way experimental switches were used to suppress effects that can mimic the signal of interest. The methods used to search for systematic errors, and models explaining observed systematic errors, are also described. We briefly discuss possible improvements to the experiment. [ABSTRACT FROM AUTHOR]

Published
2017
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24. Modelling of Nb influence on phase transformation behaviours from austenite to ferrite in low carbon steels.

Author

L Wang, S V Parker, A J Rose, G D West, and R C Thomson

Subjects
NIOBIUM, RATE of nucleation, PHASE transitions, MILD steel, THERMAL properties of steel
Abstract

In this paper, a new model has been developed to predict the phase transformation behaviours from austenite to ferrite in Nb-containing low carbon steels. The new model is based on some previous work and incorporates the effects of Nb on phase transformation behaviours, in order to make it applicable for Nb-containing steels. Dissolved Nb atoms segregated at prior austenite grain boundaries increase the critical energy for ferrite nucleation, and thus the ferrite nucleation rate is decreased. Dissolved Nb atoms also apply a solute drag effect to the moving transformation interface, and the ferrite grain growth rate is also decreased. The overall transformation kinetics is then calculated according to the classic Johnson–Mehl–Avrami–Kolmogorov (JMAK) theory. The new model predictions are quite consistent with experimental results for various steels during isothermal transformations or continuous cooling. [ABSTRACT FROM AUTHOR]

Published
2016
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25. Ex vivo electrical impedance measurements on excised hepatic tissue from human patients with metastatic colorectal cancer.

Author

S Prakash, M P Karnes, E K Sequin, J D West, C L Hitchcock, S D Nichols, M Bloomston, S R Abdel-Misih, C R Schmidt, E W Martin Jr, S P Povoski, and V V Subramaniam

Subjects
ELECTRIC impedance, TUMORS, TISSUES, ELECTRIC conductivity, COLON cancer patients
Abstract

Point-wise ex vivo electrical impedance spectroscopy measurements were conducted on excised hepatic tissue from human patients with metastatic colorectal cancer using a linear four-electrode impedance probe. This study of 132 measurements from 10 colorectal cancer patients, the largest to date, reports that the equivalent electrical conductivity for tumor tissue is significantly higher than normal tissue (p < 0.01), ranging from 2–5 times greater over the measured frequency range of 100 Hz–1 MHz. Difference in tissue electrical permittivity is also found to be statistically significant across most frequencies. Furthermore, the complex impedance is also reported for both normal and tumor tissue. Consistent with trends for tissue electrical conductivity, normal tissue has a significantly higher impedance than tumor tissue (p < 0.01), as well as a higher net capacitive phase shift (33° for normal liver tissue in contrast to 10° for tumor tissue). [ABSTRACT FROM AUTHOR]

Published
2015
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