Sheffield University Research Articles

Response of the ionosphere to super geomagnetic storms: Observations and modeling

The relative importance of the main drivers of positive ionospheric storms at low-mid latitudes is studied using observations and modeling for the first time. In response to a rare super double geomagnetic storm during 07–11 November 2004, the low-mid latitude (17°–48°N geomag. lat.) ionosphere produced positive ionospheric storms in peak electron density (NmF2) in Japan longitudes (≈125°–145°E) on the day of main phase (MP1) onset (06:30 LT) and negative ionospheric storms in American longitudes (≈65°–120°W) on the following day of MP1 onset (13:00–16:00 LT). The relative effects of the main drivers of the positive ionospheric storms (penetrating daytime eastward electric field, and direct and indirect effects of equatorward neutral wind) are studied using the Sheffield University Plasmasphere Ionosphere Model (SUPIM). The model results show that the penetrating daytime (morning–noon) eastward electric field shifts the equatorial ionisation anomaly crests in NmF2 and TEC (total electron content) to higher than normal latitudes and reduces their values at latitudes at and within the anomaly crests while the direct effects of the equatorward wind (that reduce poleward plasma flow and raise the ionosphere to high altitudes of reduced chemical loss) combined with daytime production of ionisation increase NmF2 and TEC at latitudes poleward of the equatorial region; the later effects can be major causes of positive ionospheric storms at mid latitudes. The downwelling (indirect) effect of the wind increases NmF2 and TEC at low latitudes while its upwelling (indirect) effect reduces NmF2 and TEC at mid latitudes. The net effect of all main drivers is positive ionospheric storms at low-mid latitudes in Japan longitude, which qualitatively agrees with the observations.

An additional layer in the low-latitude ionosphere in Indian longitudes: Total electron content observations and modeling

The paper presents the observations and modeling of an additional layer in the low‐latitude ionosphere in Indian longitudes. The signatures of the additional layer are observed as ledges or humps between the equatorial ionization anomaly trough and crest (EIA) in the latitudinal profiles of total electron content (TEC), measured using a single ground‐based beacon receiver located at Trivandrum (8.5°N, 77°E, dip 0.5°N) in India. The ground‐based ionograms also show the presence of the so‐called F3 layer for a short duration corresponding to these signatures, and the layer is found to drift upward to the topside ionosphere. The study provides first observational evidence that the so‐called “humps” in the latitudinal variation of TEC are nothing but the upward propagating F3 layer. This conclusion is supported by theoretical modeling using the Sheffield University Plasmasphere Ionosphere Model. It is shown that upward ExB drift and strong equatorward neutral wind (perturbed by atmospheric waves) can produce the humps in the latitudinal variation of TEC through the reduction in the downward diffusion of ionization along geomagnetic field lines. The model results also show that the F3 layer drifts to the topside and forms topside ledges.

Dedication of sheffield tutors and support staff

On behalf of my fellow nursing students, I would like to say thank you to the tutors and administration staff from Sheffield University based at Humphrey Davy House. We will be qualifying this week as registered nurses (learning disabilities). Our tutors and the administration staff have gone above and beyond their remit to see us through the past three years.

The Canadian Contact Centre Industry: Strategy, Work Organization & Human Resource Management

Enormous growth has occurred in the contact centre segment of the Canadian economy over the past decade. In part due to re-engineering, restructuring, and outsourcing, as well as to the technological changes that have facilitated this growth, the contact centre sector has experienced enormous growth and considerable changes. Widespread diversity in this sector is now evident - both in terms of employment practices as well as in outcomes experienced by employees. Despite this dynamic growth and increasing heterogeneity, relatively little is known about this industry on any systematic basis. This report is a first step in creating a deeper understanding about this sector's employment practices and about outcomes of interest to both firms and workers. This study funded by the Social Sciences and Humanities Research Council (SSHRC) is part of the Global Call Centre Project, the first large-scale coordinated international study of work and human resource practices in call centres that includes over twenty countries worldwide. This project is coordinated by Rosemary Batt (Cornell University), David Holman (Sheffield University), and Ursula Holtgrewe (Forba). In this report, we present important data for Canadian contact centre managers. The results are based on responses from 406 contact centre managers in a broad array of industries and in all ten provinces, and site visits to contact centres located across Canada. We collected data on hiring practices, technology use, location decision criteria, work organization choices from contact centres that serve a wide range of industries - financial services, telecommunications, retail, IT and technical support services, hospitality, manufacturing, print and media, and public and non-profit sectors. We analyze management and employment practices from multiple perspectives including region, organizational characteristics (inhouse, outsource, union & non-union), and type of work performed by the contact centre.

City Form: The Sustainable Urban Form Consortium

On November 1st 2005, the Faculty of Architecture and Planning, Thammasat University, was honouredto welcome Professor Mike Jenks from Oxford Brookes University, UK to lecture about the multidisciplinaryresearch project he has been involved with under the title “City Form: The Sustainable Urban Form Consortium.”The lecture aims to present the progress and methods of the ongoing project in the UK jointly taken byOxford Brookes University, Sheffield University, Heriott-Watts University, University of Straclyde and Universityof Leicester as well as fourteen private sectors, local authorities and organizations.
 Professor Mike Jenks is presently the head of Department of Architecture, Oxford Brookes Universityand the founder and director of Oxford Centre for Sustainable Development. He has been one of the leadingpioneers in sustainable urban design, and has lectured and authored numerous books and articles relatingto the concept of Compact Cities and Sustainable Urban Forms.

Neither one thing nor the other

Dear Editor, Up until June this year Alex McClimens was my personal tutor at Sheffield University while studying for the advanced diploma in nursing studies. I accept some of what Dr McClimens says in his article ‘Up-front and personal’ in the September issue of LDP (9, 7, 31) about social conditions affecting the health of people with learning disabilities and the line between health and social care often being blurred. However, I take exception to the idea that as a learning disability nurse I will not have the wherewith-all to work in an holistic manner for the greater good of the people in my care. This new ‘hybrid’ will be neither ‘fish nor foul’.

Professor Arthur J. Willis (1922–2006)

Professor Arthur J. Willis (1922–2006)

Obituary

Obituary

Unusual early morning development of the equatorial anomaly in the Brazilian sector during the Halloween magnetic storm

The solar events that occurred at the end of October 2003 gave rise to very strong geomagnetic disturbances that peaked twice with Dst values reaching −345 nT around 0000 UT on 30 October and −400 nT around 2300 UT, on the same day. Disturbances in several ionospheric parameters were observed over Brazil. This work will focus on the ionospheric response to the initial westward prompt penetration electric field and on the strong intensification of the equatorial ionization anomaly that occurred because of the electric field polarity reversal that followed in the early morning hours of 29 October. The F layer peak height over the equator first decreased under the strong prompt penetration westward electric field, which was followed by significant height increase under eastward electric field. We have used Sheffield University Plasmasphere Ionosphere Model (SUPIM) with an intensified westward disturbed electric field in the presunrise hours, presumably due to prompt penetration from the magnetosphere, in order to study the effect of such a field in the ionosphere. The simulation results showed that prompt penetration of magnetospheric electric fields of westward polarity to the nightside equatorial region seems to be the most probable cause of the initial F layer height decreases. The intensification of the equatorial ionization anomaly and the unusual enhancement on F layer peak density, which was not modeled by the SUPIM, are explained as caused by the strong eastward electric field that followed the initial phase in combination with a highly variable disturbed meridional/transequatorial wind system as inferred from the F2 layer peak height variations. The highly dynamic wind pattern, with a short‐term response (2–4 hours), is compatible with the predictions of some previous theoretical model calculations reported in the literature.

H. A. L. Fisher: scholar and minister

H. A. L. Fisher came from an influential family, studied at Oxford and in France and Germany, and became an Oxford academic with a strong interest in public affairs. In 1912 he became Vice‐Chancellor of Sheffield University and four years later was recruited by the new British Prime Minister to become his Minister of Education. In that office he introduced a number of significant reforms: in the Education Act of 1918, in improving the status and rewards of teachers, in designing a system of national examinations and in funding universities. Some, but not all, of these reforms were eroded by the financial crises of the early 1920s. After the fall of the government he returned to Oxford as head of a college and resumed a life of scholarship, writing and administration. He died in 1940. His life illustrates perfectly the ease of transition enjoyed by his generation of men between Oxford academic life and national public service.

Finding the Middle Ground: Krestovskii, Tur, and the Power of Ambivalence in Nineteenth-Century Russian Women's Prose by Jehanne M. Gheith

MLR, IOI .3, 2oo6 9I5 There are separate entries for each of Dostoevsky's fictional works and for the most important of his journalistic and other non-fictional writings. Members of his immediate family, close friends, and associates are also well covered, as are his literary contemporaries and those authors, Russian and foreign, whose influence may be discerned in Dostoevsky's own life and work. The context in which Dostoevsky produced his works is amply suggested by entries dealing with those literary and intellectual trends and movements with which he engaged, and with themajor literary journals and newspapers of the time. In all these entries Kenneth Lantz's coverage is impressively comprehensive and his choice of detail apt and to the point. The entries dealing with Dostoevsky's works, major and minor, follow a standard pattern of contextual and publication detail, plot summary, an attempt (which is necessarily limited) at general thematic and structural analysis, acknowledgement of sources used, and recommendations for targeted further reading. The reception of individual works is touched upon only intermittently; yet this is an area that could usefully have been given fuller treatment, in that it is not the sort of information the general reader (especially one with no Russian) can easily find in a single source elsewhere. As well as the entries devoted to individual works, Lantz provides some thirty brief essays dealing with major themes and issues inDostoevsky's life and works. It is here that a reviewer might be most expected to take issue with the author's choice of what should, and should not, be included; but, in the opinion of this reviewer, Lantz has got it broadly right in identifying the key issues likely to interest his readership. Some might regret the lack of a discrete general entry on Dostoevsky's approach to narrative, but the subject is touched upon elsewhere (for example, under 'Realism' and 'Dreams and the Unconscious'). One might wonder about the likely readership of a volume such as this, in that it is arguable that Lantz offers too much for the general reader (who is, for example, unlikely to be interested in Dostoevsky's friends, family, and lesser works) and too little for the student, who might wish for less in the way of factual detail and plot summaries, and more in the way of sustained analysis. But, given the brief of the volume, Lantz has carried it out lucidly, conscientiously, and comprehensively. The high productionvalues go a long way towards justifying aprice that will, one suspects, put the volume beyond most individual purchasers. UNIVERSITY OF SHEFFIELD W. J. LEATHERBARROW Finding theMiddle Ground: Krestovskii, Tur, and the Power of Ambivalence inNine teenth-Century Russian Women's Prose. By JEHANNE M. GHEITH. (Northwest ern University Press Studies in Russian Literature and Theory) Evanston, IL: Northwestern University Press. 2004. xx+302 pp. ?65.95. ISBN o-8ioi I7I4-2. Finding the Middle Ground serves at least three purposes, all of which are of interest to literary researchers and cultural historians. Gheith's study casts light on thewritings of Evgeniia Tur (i 8I 5-92) and 'V.Krestovskii' (Nadezhda Khvoshchinskaia) (i 8z20? 89), who were two of the most widely read authors and critics of themid-nineteenth century; it also provides a comprehensive account of the quasi-institutional literary context inwhich they functioned not only as authors but aswidely published critics, and, in the case of Tur, as organizer of salons attended by the better-known (male) literary-cultural activists of the day. Finally, the book addresses significant questions of literary conventions and canonicity, and their relationship to gendered cultural norms, with elegance and insight. 9I6 Reviews The six chapters of the work are organized into three overarching divisions: biography, the authors as critics, and textual analysis. Gheith avoids the problems commonly raised by naive biographical criticism by examining extant biographical, autobiographical, and other 'life-texts' (e.g. correspondence) from the point of view of their shared relationship to dominant cultural norms about gender and author ship. In this way, essential biographical information is imparted in the context of a sophisticated discussion of the prevailing tropes for and about women writers in the life-writing genres of the time...

The History of the Gulag: From Collectivisation to the Great Terror by Oleg V. s> Khlevniuk (review)

170 SEER, 84, I, 2006 growthin membership from28,ooo in I945 to 1.4 million in late I947, and popular demonstrations of support for Klement Gottwald (a photograph of which occupies the front cover), but the degree to which these matters are connected to the intellectualdiscussionis not sufficientlyexplored. Overall, this is an excellent book, meticulously researched and well organized, it succeeds in settinga new agenda for Czechoslovak historyin the Cold War-free world. There is, however, one telling downside. Like other historiansof Czechoslovakia,Abramshas chosen to focus on Czechs only and the Slovak story is omitted. Given the different experience of Czechs and Slovaksduring the Second WorldWar and the emphasisAbramsgives to the war in crystallizingCzech disenchantment, much more might have been said about the Slovakcase. Department ofHistory SAMJOHNSON University ofSheffield Khlevniuk, OlegV. 7heHistogy oftheGulag. From Collectivisation totheGreat Terror. Annals of Communism. Translatedby VadimA. Staklo.YaleUniversity Press, New Haven, CT and London, 2004. xix + 4I8 pp. Map. Tables. Illustrations.Notes. Appendices. Indexes. $39.95: 925.00. INhis excellent and importantcontributionto this distinguishedseries,which presents 'previously inaccessible documents from former Soviet state and partyarchivesin a narrativethat develops a particulartopic', Oleg Khlevniuk publishes Io6 documents, and many other extracts are included in his commentary. His selection and interpretationof this material, like his other work,demonstrateshisplace in the forefrontof the new generationof Russian historians of the Communist era. The sources he prints are mainly 'official documents' from the state archive: confidential correspondence, circular lettersand memoranda, officialreportsand resolutions,individualtestimonies and tabulated statistics, but this does not prevent him from presenting a poignant and heart-rendingportraitof the prisonersand theircondition. The notorious torture of the punishment system is vividly portrayed in reports from officials trying to make their superiors conform to central guidelines. The range of documents is extensive.At opposite extremesthereis, on the one hand, a 1932 letter to Molotov from a casual visitor, describing the pitiable condition of prisoners in a Siberian camp (pp. 30-32); on the other, a 1938 letter to Molotov from Ezhov, requestingfundsfor the mass repressionof the 'kulak operation' (pp. I63-64). There is also a considerable amount of material on less well-known aspects of the history of the Gulag, for instance children's colonies. A final chapter reviews the evidence on the scale of the repressionsand the data on the size of the camp population. Khlevniuk'sfocus is on the development of the gulag system(ratherthan on the camps), and the title does not reveal an importantdimension of this book: his examination of the repressionsof the I930S and of the Great Terror. He also discussesBeria's'reforms'which ended the Terror,and 'Mobilisationand Repression' 1939-4I (pp. I86-286), including the mass deportations from territorythe USSR acquired afterAugust 1939 in 'the bloody liquidation of REVIEWS 171 the "fifth column"' and the Katyn massacre (pp. 236-37). In this groundbreaking study, which contains a considerable amount on policymaking , Khlevniuk depicts the Gulag systemas a 'direct reflection' of the development of Stalinist dictatorship in the I930S (p. 8). He correlates the evolution of the Gulag with the stagesin the political and economic historyof the decade. The Politburo decision of June I929 to create a network of selfsupportingcamps , which coincided with mass repressionsassociatedwith the adoption of the policies of forced collectivization and rapid industrialization, led to a more rapid growth of the camps than projected (p. i o). Another decision in May I930 to build the White Sea-Baltic Canal using convict labour, establisheda pattern of large camps servicinggiant constructionsites. Stalin'ssupportfor the OGPU, and the policy of transferringprisonersto the camps was decisive in making the camps one of the main elements of the Soviet penal systemand the Gulag 'an integralpart of Soviet life' (p. 28). The pattern of large camps was reinforcedby a tragicallyunsuccessfulexperiment with labour exile in remote regions, in response to repression to control the famine crisis of 1932-33. This was followed by a period of stabilizationuntil I936 when repressionranat a lowerlevel, but new economic taskswere added to the OGPU's existingprojects. Khlevniuk consolidates the case he has made elsewhere that 'the Great Terrorwas a centrallyorganized punitive action, planned in Moscow, against a potential fifth column perceived as capable of stabbing the country in the back in case...

Theoretical study of the low‐ and midlatitude ionospheric electron density enhancement during the October 2003 superstorm: Relative importance of the neutral wind and the electric field

During magnetic storms the ionospheric total electron content (TEC) at low‐ and midlatitudes often shows great enhancements, which may be associated with mechanisms producing midlatitude storm‐enhanced density (SED). The TEC enhancements may result from different ionospheric drivers such as electric fields, neutral winds, and neutral composition effects. To study the importance of the ionospheric drivers in producing the TEC enhancement, we perform numerical simulations for the 29–30 October 2003 superstorm period in the American longitude sector (∼ −70°W) using the Sheffield University Plasmasphere Ionosphere Model (SUPIM) with values for the neutral wind, temperature, and composition provided by the National Center for Atmospheric Research (NCAR) Thermosphere Ionosphere General Circulation Model (TIEGCM). Various numerical experiments were run to identify the relative importance of the storm‐time ionospheric drivers. For carrying out the storm‐time SUPIM simulation, the storm‐time upward/poleward E × B drifts are derived from ROCSAT‐1 satellite measurements at low and equatorial latitudes and input to SUPIM, while the storm‐time neutral wind and composition disturbances are obtained from TIEGCM run. The simulation results presented in this paper, mainly during the evening period, show that the enhanced upward E × B drifts due to storm‐time eastward penetration electric field can expand the low‐latitude equatorial ionization anomaly (EIA) to higher latitudes and produce the TEC enhancement. However, by the effect of penetration electric fields alone, the TEC enhancement is less than by combining the storm‐generated equatorward neutral winds and the penetration electric fields. Disturbance neutral composition effects decrease the plasma density at higher latitudes and increase it at low and equatorial latitudes. However, the composition effects do not produce a density increase as large as that produced by the neutral‐wind and electric‐field effects. Our simulations suggest that the storm‐generated equatorward neutral winds play an important role in producing the TEC enhancement at low‐ and midlatitudes, in addition to the eastward penetration electric field.

On the Use of Audio-Tapes for Teaching Vector Analysis to Engineering Undergraduates

An audio-tape with an accompanying booklet of notes has been prepared specifically for teaching the topic of vector analysis to engineering undergraduates in their second year of study at Sheffield University. The audio-tape package was designed to replace four conventional lectures. The implications of introducing an innovative teaching practice into a mathematically based discipline are discussed. The reactions of two cohorts of students on whom this teaching innovation was trialled are described. It was deduced that students are likely to be more receptive to an alternative teaching practice if they are encouraged to participate in the decision-making processes concerning the details of its implementation. Such activities generate the concept of ‘shared ownership’, which tends to promote more positive student feedback.

The Petrine Revolution in Russian Culture by James s> Cracraft (review)

760 SEER, 83, 4, 2005 which will be of interestto readersof the Slavonic Review, Leighton'sis the most valuable. The studies of freemasonry in Hungary and the late Ottoman Empire offer useful but relatively short and superficialintroductions to the historyof freemasonryin these areas. Of the new material,two papersstandhead and shouldersabove the others: David Stevenson's masterly and thought-provoking reappraisal of James Anderson, the Presbyterian clergyman who compiled the first Book of Constitutions of the London Grand Lodge; and a gem of an essay by Rebecca Coombes on the Libraryand Museum of Freemasonryin London, which not only gives a succinct guide to these collections, but also provides fascinating case studies in masonic bibliography. These, together with the solidly researchedand clear pieces by Lisa Kahler on early Scottish lodges,Jennifer Macleod on music and freemasonry in eighteenth-century Edinburgh, Richard Rutyna on Virginia freemasons, and Kathleen Kutolowski on the Anti-Masonic party in the United States, mean that the book will become a standard reference, but all users will quickly conclude that it is a bloated volume, which would have been twice as good if half the size. The book is sadly marred by slipshod copy editing and proof reading, and lacks an adequate index, essential in a book of this size. The poor editorial and production standards of the book are summed up by the editors' random insertion of badly pixellated black and white illustrationswhose relevance to the text is mostlynot evident. Centrefor Research intoFreemasonry ANDREW PRESCOTT Humanities Research Institute, University ofSheffield Cracraft,James. 7The Petrine Revolution inRussianCulture. The BelknapPressof Harvard University Press, Cambridge, MA and London, 2004. xii + 560 pp. Illustrations. Figures. Appendices. Notes. Bibliography. Index. J32-95. THIsbook is the culmination of an ambitious, one might say heroic project, which began with 7hePetrine Revolution in RussianArchitecture (Chicago, IL, I988) and T7he Petrine Revolution inRussian Imagegy (Chicago, IL, I997). (See my reviews in Russian Review, 49, I990, P. 336, and SEER, 77, I999, I, P. I71.) This finalvolume bearswhat might have servedas the overarchingtitle of the trilogy,but in factits subjectis 'verbalculture'.Findingthe rightwordfornew things and renaming old ones was a fundamental aspect of 'modernization', as Peter the Great (an indifferent linguist) appreciated. A decree of 26 November I7i8 introducingnewformsof socialgatheringexplained:'Assemblei is a Frenchword, which cannot be expressedin Russianin one word.' Similar problems arose constantly, from naming parts of ships to designating new court ranks. James Cracraft'sstudyprovidesa wealth of such examples. Beginningwith a considerationof generaltheoriesof 'culturalrevolution',modernizationand related themes and some backgroundto the history of the Russian language before Peter'sreign, the author then includes four chapters devoted respectively to naval affairs,military modernization, bureaucracy, and science and REVIEWS 76I literature(the last two perhaps slightly awkwardbedfellows). In each he sets out the European background, which he underpins by reference to key theoriesand studies,thusembedding Peterin thewiderEuropeancontext. He then outlinesthe keyfeaturesof the establishmentof the Russiannavy, reform of the army and so on, before focusing on major printed works, such as the NavalStatueof I720, the MilitaryStatueof 17I6 and the General Regulation of I 720, translated books on geometry, astronomy, geography and other practical topics, and shorter texts, including government decrees, analysing criticalpassagesand highlightingnew vocabulary.Each of these chaptersalso examines the related area of educational reform, for example, the establishment of naval and militaryschools and the Academy of Sciences. Chaptersix, on the 'language question', generalizes on the basis of the lexical evidence presented earlier, considering, among other things, publishing and printing, the invention of the modern Russian 'Civic' alphabet in I708- io, and dictionaries and grammars. Chapter seven offers a brief conclusion to the whole trilogy,drawingparallelsbetween changesin architecture,imageryand verbal culture and reiterating the author's belief that Peter created a 'revolution' in Russian life, albeit a 'top-down "revolution by decree", narrowlyelitistat first'(p. 309). (A usefulsummaryaimed at studentsand the general reader can be found in ProfessorCracraft's TheRevolution ofPeterthe Great, Cambridge,MA, 2003.) That the Russian literary language changed during Peter's reign is not a new discovery. There have been a number of specialized studies of 'Petrine language', mostly in Russian and German, but nothing really accessible to historians as opposed to linguists. No previous author has attempted to set Petrine verbal culture in...

Current pledges safe at university of sheffield

Current pledges safe at university of sheffield

Extreme total electron content along satellite‐to‐satellite ray paths

This paper reports results from an investigation into possible total electron content (TEC) on ray paths between GPS satellites and satellites in geostationary orbit. The Sheffield University Plasmasphere Ionosphere Model (SUPIM) has been used to estimate the TEC for conditions appropriate to solar maximum as a first step to assessing possible errors in the potential use of the navigation satellites for station keeping in the geostationary orbit. It has been found that in general, for paths through the plasmasphere, where the satellite‐to‐satellite geometry is far removed from eclipse by the Earth's horizon, the TEC is usually less than 20 TECU (total electron content units, 1 TECU = 1016 el m−2) with resultant errors in single‐frequency GPS positioning of a only a few meters. However, when the rays cross the equatorial F2 ionosphere at near‐grazing incidence close to the layer peak, TEC of up to some 2000 TECU have been found, with consequent potential single‐frequency GPS positioning uncertainties of hundreds of meters. The exact magnitudes of the TEC are very dependent on the precise geometry and vary significantly with time, so they would be difficult to simulate in any real‐time, model‐based mitigation system.

Key Role for UK Companies in Boeing's New Dreamliner

The UK has Europe's biggest, and the world's second largest, aerospace industry by number of employees. The head of Boeing UK explains how British companies, like Rolls Royce and Smith Instruments, and institutes like Sheffield University's Advanced Manufacturing and Research Centre, have contributed to Boeing's largest ever launch.

Studies of fluid bed granulation in an industrial R&D context

Following a brief overview of recent developments in laundry powder processing by comparison with other areas of industrial application, and current drivers and trends, a review is presented of collaborative research between Unilever R&D and Sheffield University on fluidised bed granulation using melt binders. These fall apart into 4 areas: 1. Contact zone studies; 2. Growth similarity for non-ideal systems; 3. Growth and breakage decoupled; 4. Scale-up rules based on similarity of growth kinetics. The emphasis of the paper is on the identification and relative quantification of the dominant mechanisms, which are found in the balance of fluxes of solids and binder, together with heat transfer and conduction, not so much binder viscosity. These mechanisms allow for the control of the growth kinetics and rapid scale-up. Together, this lays the broad ground-work for fluidised bed granulation. Some concluding remarks provide pointers for the future of research in this area: • There is a strong requirement for multi-dimensional phase volume distribution based population balances. • Many processes require pre-granulation, and liquid–liquid contact in the spray-zone is scarcely investigated. • Simple combined Lagrangian–Eulerian modelling implemented in commercial code environment can be especially useful to investigate the effects of the relations between material properties and process conditions on growth kinetics.

Contribution of Transmembrane Regions to ATP-gated P2X2 Channel Permeability Dynamics

ATP-gated P2X(2) channels undergo activation-dependent permeability increases as they proceed from the selective I(1) state to the I(2) state that is readily permeable to organic cations. There are two main models about how permeability changes may occur. The first proposes that permeability change-competent P2X channels are clustered or redistribute to form such regions in response to ATP. The second proposes that permeability changes occur because of an intrinsic conformational change in P2X channels. In the present study we experimentally tested these views with total internal reflection fluorescence microscopy, electrophysiology, and mutational perturbation analysis. We found no evidence for clusters of P2X(2) channels within the plasma membrane or for cluster formation in response to ATP, suggesting that channel clustering is not an obligatory requirement for permeability changes. We next sought to identify determinants of putative intrinsic conformational changes in P2X(2) channels by mapping the transmembrane domain regions involved in the transition from the relatively selective I(1) state to the dilated I(2) state. Initial channel opening to the I(1) state was only weakly affected by Ala substitutions, whereas dramatic effects were observed for the higher permeability I(2) state. Ten residues appeared to perturb only the I(1)-I(2) transition (Phe(31), Arg(34), Gln(37), Lys(53), Ile(328), Ile(332), Ser(340), Gly(342), Trp(350), Leu(352)). The data favor the hypothesis that permeability changes occur because of permissive motions at the interface between first and second transmembrane domains of neighboring subunits in pre-existing P2X(2) channels.