| 1. |
- Schael, S, et al.
(författare)
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Precision electroweak measurements on the Z resonance
- 2006
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Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
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Forskningsöversikt (refereegranskat)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
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| 2. |
- Bale, S. D., et al.
(författare)
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The FIELDS Instrument Suite for Solar Probe Plus
- 2016
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Ingår i: Space Science Reviews. - : Springer Science and Business Media LLC. - 0038-6308 .- 1572-9672. ; 204:1-4, s. 49-82
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Forskningsöversikt (refereegranskat)abstract
- NASA's Solar Probe Plus (SPP) mission will make the first in situ measurements of the solar corona and the birthplace of the solar wind. The FIELDS instrument suite on SPP will make direct measurements of electric and magnetic fields, the properties of in situ plasma waves, electron density and temperature profiles, and interplanetary radio emissions, amongst other things. Here, we describe the scientific objectives targeted by the SPP/FIELDS instrument, the instrument design itself, and the instrument concept of operations and planned data products.
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| 3. |
- Aisling, Lynch, et al.
(författare)
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Crystal Growth of Single Salicylamide Crystals
- 2019
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Ingår i: Crystal Growth & Design. - : American Chemical Society (ACS). - 1528-7483 .- 1528-7505. ; 19:12, s. 7230-7239
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Tidskriftsartikel (refereegranskat)abstract
- Growth of single salicylamide crystals was investigated in a nonstirred growth cuvette and on a rotating disk. In the growth cuvette the crystal growth rates were measured for both primary nucleated crystals and seed crystals manually inserted into the cuvette. In the rotating disk experiments multiple seed crystals were attached to a disk that was rotated in a supersaturated solution. The crystal growth rates in the length and width direction were precisely measured in situ for each individual crystal, and growth rates were also extracted for a specific crystal facet, that is, (200). In all cases, the growth rate was considerably faster in the rotating disk experiments, shown to be governed by surface integration. Solvent was found to impact the growth rates of the crystal facets in part by creating different surface features. The influence of the supersaturation on the crystal growth rate depended on the solvent; in general, an increasing trend was observed. At relatively low supersaturations, it was discovered that the growth process will focus on repairing morphological defects. Within the range of experimental conditions, the growth kinetics were strongly affected by the temperature as was further indicated by the relatively high activation energy values obtained. The crystal seed quality was found to have a substantial impact on the growth rate, with rougher crystals leading to quicker growth. A wide growth rate dispersion was obtained for both crystal growth methods, found to be reduced by using seed crystals with high quality, lower supersaturations, and also within certain solvents.
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| 4. |
- Lynch, Aisling, et al.
(författare)
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Crystal Growth of Salicylamide in Organic Solvents
- 2018
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Ingår i: Crystal Growth & Design. - : American Chemical Society (ACS). - 1528-7483 .- 1528-7505. ; 18:12, s. 7305-7315
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Tidskriftsartikel (refereegranskat)abstract
- Salicylamide was used as a model active pharmaceutical compound to investigate the crystal growth process and its associated kinetics. The impact of organic solvent, supersaturation, and temperature on the crystal growth was studied. The multiparticle crystal growth kinetics were determined using the seeded isothermal desupersaturation method and modeled using several growth rate equations, using different representations of the driving force. The results showed that crystal growth is significantly influenced by experimental conditions. Within the range of experimental conditions, the growth kinetics was affected strongly by the temperature and to a lesser degree by solvent choice. Comparison of the growth order parameter reveals a surface integration controlled growth. Higher than expected activation energies indicate desolvation as a governing process. A comparison of the influence of the solvent on the crystal growth of salicylamide against previously published approximate data at much higher supersaturation shows good agreement, but the influence on the interfacial energy is opposite to that observed for crystal nucleation. In a detailed comparison with crystal growth data of salicylic acid, there is a consistency in the influence of the solvent on the crystal growth of the two compounds. Salicylamide growth kinetics is more strongly affected by increasing temperature than salicylic acid.
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| 5. |
- Lynch, A., et al.
(författare)
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Face indexing and shape analysis of salicylamide crystals grown in different solvents
- 2019
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Ingår i: CrystEngComm. - : Royal Society of Chemistry. - 1466-8033. ; 21:16, s. 2648-2659
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Tidskriftsartikel (refereegranskat)abstract
- The effect of solvent on salicylamide's crystal habit was investigated. Crystals grown experimentally in acetone, acetonitrile and methanol matched the attachment energy predicted rectangle plate vacuum habit. However, in ethyl acetate irregular hexagonal plate crystals form. This change in habit was found to be caused by the stunted growth of specific crystal faces during the crystallisation process. Single crystal and powder X-ray diffraction was carried out to rule out the possibility of a new polymorph. Given no new polymorphs were discovered, the changing habit makes face indexing of experimentally grown crystals difficult. A combination of experimental and modelling prediction tools was employed for the face indexing process. The interfacial angle between faces combined with preferred orientation P-XRD was found to be the most accurate and reliable method leading to successful identification of each salicylamide crystal face. The surface chemistry of each face was examined on a molecular level with insights into the possible growth attachment sites being made. It is deduced that ethyl acetate is adsorbed more strongly on the faces, the increased size of which, can explain the shape change.
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| 6. |
- Lynch, Aisling, et al.
(författare)
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Single Crystal Growth Kinetics of Two Polymorphs of Piracetam
- 2021
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Ingår i: Crystal Growth & Design. - : American Chemical Society (ACS). - 1528-7483 .- 1528-7505. ; 21:10, s. 5631-5640
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Tidskriftsartikel (refereegranskat)abstract
- The crystal growth of single crystals of the metastable and stable polymorph of piracetam (PCM) in ethanol and isopropanol has been investigated using the rotating disk (RD) technique. A number of seed crystals were attached onto a disk that was rotated in a supersaturated solution. The crystal growth rate in length and width directions was measured for each individual crystal, and the growth rates were also extracted for the (011) crystal facet. The metastable FII form was found to exhibit a faster growth rate than the thermodynamically stable FIII form. The impact of solvents, supersaturation, temperature, and crystal seed properties was studied. Within a range of experimental conditions, the growth kinetics of both polymorphs were strongly affected by the temperature and, to a lesser degree, by the solvent choice. For both polymorphs, faster growth rates were obtained in ethanol than in isopropanol. The growth rate exhibits a fairly linear increase with increasing supersaturation for both polymorphic forms, but the slope is different. By fitting the Burton Cabrera Frank (BCF) and Birth and Spread (B + S) theories to the growth rate data at different supersaturations and temperatures in ethanol, a lower interfacial energy and a longer mean diffusion distance on the surface is obtained for the metastable polymorph compared to the stable form. The crystal growth rates measured in the present study are in good agreement with the data previously determined using isothermal desupersaturation experiments (ISD), and so are the fundamental parameters estimated by the BCF and the B + S theories.
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| 7. |
- Mella, M. R., et al.
(författare)
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Sounding rocket study of two sequential auroral poleward boundary intensifications
- 2011
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Ingår i: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 116, s. A00K18-
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Tidskriftsartikel (refereegranskat)abstract
- The Cascades-2 sounding rocket was launched on 20 March 2009 at 11: 04: 00 UT from the Poker Flat Research Range in Alaska, and flew across a series of poleward boundary intensifications (PBIs). The rocket initially crosses a diffuse arc, then crosses the equatorward extent of one PBI (a streamer), and finally crosses the initiation of a separate PBI before entering the polar cap. Each of the crossings have fundamentally different in situ electron energy and pitch angle structure, and different ground optics images of visible aurora. It is found that the diffuse arc has a quasi-static acceleration mechanism, and the intensification at the poleward boundary has an Alfvenic acceleration mechanism. The streamer shows characteristics of both types of acceleration. PFISR data provide ionospheric context for the rocket observations. Three THEMIS satellites in close conjunction with the rocket foot point show earthward flows and slight dipolarizations in the magnetotail associated with the in situ observations of PBI activity. An important goal of the Cascades-2 study is to bring together the different observational communities (rocket, ground cameras, ground radar, satellite) with the same case study. The Cascades-2 experiment is the first sounding rocket observation of a PBI sequence, enabling a detailed investigation of the electron signatures and optical aurora associated with various stages of a PBI sequence as it evolves from an Alfvenic to a more quasi-static structure.
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| 8. |
- Soto, Rodrigo, et al.
(författare)
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Crystal Growth Kinetics of Pharmaceutical Compounds
- 2020
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Ingår i: Crystal Growth & Design. - : American Chemical Society (ACS). - 1528-7483 .- 1528-7505. ; 20:12, s. 7626-7639
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Tidskriftsartikel (refereegranskat)abstract
- The crystal growth kinetics of piracetam, fenofibrate, phenylbutazone, acetaminophen, carbamazepine, and risperidone in methanol have been studied by two different methods; the isothermal seeded desupersaturation experiment (ISD) and the rotating disk technique (RD). Data has been collected in the range of temperature 288-303 K and at different supersaturations for the ISD experiments. The RD experiments were performed at constant supersaturation. In the ISD experiments, principal component analysis has been used to relate solution concentrations from IR measurements. An empirical power law equation has been fitted to the experimental desupersaturation data, and parameter values suggest surface integration control for all the APIs studied, a conclusion further supported by a separate mass transfer analysis. The order of rate of growth among the compounds and the magnitude of the growth rates determined by the two methods are in good agreement. In addition, the Burton Cabrera Frank (BCF) and Birth and Spread (B+S) surface integration models have been fitted to the ISD desupersaturation data, and average solid-liquid interfacial energies, mean diffusion distances, and surface mass transport rates have been estimated. An analysis of the experimental results and the growth rate parameters is performed to examine to what extent the difference in growth rate of different compounds can be rationalized.
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