bluuebunny/crossref_metadata_2025 huggingface dataset:
The Star’s Image, Victimization and Celebrity Culture
Authors: Penfold Ruth
Published: June 2004

Today we live in a celebrity culture, in which images of stars, people who are famous for being famous, are circulated and consumed as a daily practice by people across the world. This article explores the cultural reception of celebrity victimization, relating this to the twinned processes of globalization and commodification. The arguments made are illustrated through an analysis of the case of Charles Lindbergh, whose infant son was murdered during the inter-war years. Lindbergh’s transatlantic flight of 1927 was a global media-event in which the new mobilities of persons and images were highly condensed. Mediated visibility launched him into unprecedented acclaim, yet his fame unfolded in part as a negative status, as a kind of victimization. Analysis of this case permits a study of the relationships between images, celebrity and victimization.
Media and Crime Policy
Authors: Cavender Gray
Published: June 2004

In this article, I use the tenets of media studies scholarship to reformulate David Garland’s account of the shifts in sanctioning policy that began in the 1970s. I address the media’s prominent role in shaping public mentalities and sensibilities that were incompatible with penal welfarism and supportive of more punitive policies. In particular, I analyze media coverage of the policy debate and also dramatic depictions of crime. I argue that the media were more influential in shaping public attitudes toward sanctioning policy than Garland suggests.
‘Mission Impossible’?
Authors: Hughes Gordon , Gilling Daniel
Published: June 2004

It is difficult to ignore the growing salience of the new governance of crime and disorder in many late modern societies. To date there has been limited empirical exploration of the practices and experiences of these new local actors and institutions. This article aims to correct this neglect in the criminological literature by its exploration of the knowledge and skills base and habitus of one of the new partnership experts, the community safety manager (CSM). In particular, the article involves an engagement with recent research findings from Britain together with the more abstract conceptual tools opened up by current debates in critical social and political theory. It begins with a brief history of the community safety occupation during which the key features of the ‘profession’ are explored. Next, the thesis of a hegemonic risk management governmental logic in the field of community safety is critically examined. By exploring specific sites and contexts of community safety ‘work’, doubt is cast on totalizing narratives of neo-liberal transformation currently popular in criminology and sociology. Finally, the possible futures of community safety and crime and disorder reduction when viewed from the contemporary experiences of CSMs are considered.
Evidence-Led Policy or Policyled Evidence?
Authors: Gadd David
Published: June 2004

This article critiques the move towards establishing standardized cognitive behavioural interventions for violent men within the National Probation Service of England and Wales. The article queries the persuasiveness of the research evidence informing this policy decision, and argues that in practice a narrow focus on cognition can detract from those aspects of masculinity that are implicated in the perpetration of domestic violence. Having first explored the limits of the evaluation research that has been conducted on cognitive behavioural programmes for domestic violence perpetrators in the UK, the article utilizes a case study to illustrate the complex challenges confronting those who wish to help violent men to change. In particular, the notion that denial is only implicated in mitigating responsibility for violence is exposed as unduly simplistic. The article concludes that without greater acknowledgement of the criminal justice system’s tendency to further brutalize violent offenders, court-mandated perpetrators will continue to expect probation interventions to provide ‘cures’, and become increasingly resistant to engage when no such cures are found.
Designing Learning as Well as Teaching
Authors: Mcalpine Lynn
Published: June 2004

Many teachers of higher education wish to provide instruction that supports student learning while not always finding it easy to implement the desire. The model for a unit of instruction described here provides a mental map to overlay decisions about instructional strategies in order to assess the extent to which they align with theories of learning and with research in higher education directed to supporting learning. The model provides a framework that highlights the critical role of practice, structure and formative feedback in the learner’s preparation for formal summative assessment and is proposed as a design tool and a chronology for instruction and for learning.
Tools and Methods for Data Collection in Ethnobotanical Studies of Homegardens
Authors: Vogl Christian R. , Vogl-Lukasser Brigitte , Puri Rajindra K.
Published: June 2004

Owners and managers of homegardens have extensive knowledge of plants, their uses, and ecosystemic processes. This knowledge might be highly valuable for many purposes. To enhance ethnobotanical research on homegardens and encourage a discussion of proper methodology, this article presents tools and methods used to collect data in the multidisciplinary study of homegardens in Chiapas, Mexico; Eastern Tyrol, Austria; and Kalimantan, Indonesia. The article defines homegardens and gardeners and explains both the sampling process used in these studies and how contact and rapport was established. Also discussed are possible research questions and hypotheses, equipment used in the field, interviewing strategies, vegetation surveys, and data management. Interviews typically elicit information on preferred garden plants, plant management, homegarden management, and the history of gardening in the study area. It is concluded that homegardens present an excellent opportunity to use and experiment with both informal and formal techniques to collect qualitative as well as quantitative data.
Genetic deletion of mouse platelet glycoprotein Ibβ produces a Bernard-Soulier phenotype with increased α-granule size
Authors: Kato Kazunobu , Martinez Constantino , Russell Susan , Nurden Paquita , Nurden Alan , Fiering Steven , Ware Jerry
Published: June 2004

Here we report the characterization of a mouse model of the Bernard-Soulier syndrome generated by a targeted disruption of the gene encoding the glycoprotein (GP) Ibβ subunit of the GP Ib-IX complex. Similar to a Bernard-Soulier model generated by disruption of the mouse GP Ibα subunit, GP IbβNull mice display macrothrombocytopenia and a severe bleeding phenotype. When examined by transmission electron microscopy, the large platelets produced by a GP IbβNull genotype revealed α-granules with increased size as compared with the α-granules from control mouse platelets. Data are presented linking the overexpression of a septin protein, SEPT5, to the presence of larger α-granules in the GP IbβNull platelet. The SEPT5 gene resides approximately 250 nucleotides 5′ to the GP Ibβ gene and has been associated with modulating exocytosis from neurons and platelets as part of a presynaptic protein complex. Fusion mRNA transcripts present in megakaryocytes can contain both the SEPT5 and GP Ibβ coding sequences as a result in an imperfect polyadenylation signal within the 3′ end of both the human and mouse SEPT5 genes. We observed a 2- to 3-fold increase in SEPT5 protein levels in platelets from GP IbβNull mice. These results implicate SEPT5 levels in the maintenance of normal α-granule size and may explain the variant granules associated with human GP Ibβ mutations and the Bernard-Soulier syndrome.
TNF-related apoptosis-inducing ligand (TRAIL) blocks osteoclastic differentiation induced by RANKL plus M-CSF
Authors: Zauli Giorgio , Rimondi Erika , Nicolin Vanessa , Melloni Elisabetta , Celeghini Claudio , Secchiero Paola
Published: June 2004

The role of the tumor necrosis factor (TNF) superfamily member receptor activator of nuclear factor kappa B ligand (RANKL) in promoting the differentiation of osteoclasts has been extensively characterized. In this study, we have investigated the effect of TNF-related apoptosis-inducing ligand (TRAIL), a member of the TNF superfamily of cytokines, in osteoclastogenesis, by using human peripheral blood mononuclear cells and the RAW264.7 murine monocytic cell line. Both cell models differentiate into osteoclast-like cells in presence of RANKL plus macrophage-colony-stimulating factor (M-CSF), as evaluated in terms of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells and bone resorption activity. Unexpectedly, when added in culture in combination with RANKL plus M-CSF, TRAIL inhibited osteoclastic differentiation in both cell models. To investigate the molecular mechanism underlining such inhibitory activity, we analyzed the effect of TRAIL on the mitogen-activated protein kinases (MAPKs) pathways, which play a key role in osteoclastogenesis. Treatment with RANKL plus M-CSF activated both the ERK1/2 and p38/MAPK pathways, which are essential for proliferation and differentiation of preosteoclasts, respectively. Of note, the addition of TRAIL to RANKL plus M-CSF did not affect ERK1/2 but it profoundly inhibited p38/MAPK phosphorylation. Thus, our data demonstrate that TRAIL blocks osteoclastic differentiation and suggest that inhibition of the p38/MAPK pathway by TRAIL likely plays an important role in this process. (Blood. 2004;104:2044-2050)
The IEA's Data on Combustible Renewables and Waste from 1973 to 2000
Authors: Sun J. W.
Published: June 2004

This study examines the utilization of combustible renewables and waste in the world from 1973 to 2000 based on the International Energy Agency (IEA) databases.

The main findings are that: 1). It would seem there is a wealth of technological experience on the utilization of combustible renewables and waste in the OECD countries. However, there is just limited utilization of this technological experience in the Non-OECD countries. 2). The data on the utilization of combustible renewables and waste from 1996 to 2000 in the IEA databases may have not regulated. It should be cautious when these figures are used.
Catalytic Reactions of 1-Butanol over AlPO4 Catalysts Induced by B2O3
Authors: El-Sharkawy E.A. , Al-Shihry Shar S. , Ahmed A.I.
Published: June 2004

A series of AlPO4–B2O3 samples containing 5–50 wt% B2O3 were prepared. Their textural properties were determined from studies of the adsorption of nitrogen at −196°C. The structural characteristics were investigated using DTA, TG, XRD and FT-IR methods. Surface acidity was determined from the adsorption of n-butylamine in non-aqueous media. The vapour-phase catalytic conversion of 1-butanol over the prepared catalysts was followed using a micro-catalytic pulse technique. The incorporation of B2O3 into AlPO4, as well as the calcination temperatures employed, led to significant changes in the textural parameters and crystallinity of the catalysts and in their surface acidity. The dehydration of 1-butanol to 1-butene and dibutyl ether (DBE) was strongly influenced by the surface acidity and the boron content of the samples.
Adsorption of Glucagon and Insulin on an Immobilized Metal Ion Affinity Chromatography Silica Matrix
Authors: Farinas Cristiane S. , Bueno Sônia M.A. , Miranda Everson A.
Published: June 2004

Glucagon is a hormone that increases blood glucose concentrations and is used as a pharmaceutical product mainly in the treatment of hypoglycaemia associated with diabetes. Given both its importance and high current cost, improved purification processes are in demand. By using immobilized metal ion affinity chromatography (IMAC), we conducted tests aimed at the purification of glucagon from complex mixtures. Adsorption studies of glucagon, insulin and a mixture of the two on adsorbents of silica–IDA–Me2+ (Cu2+, Ni2+ and Zn2+) were carried out. Fixed-bed chromatographic experiments were performed and the adsorption affinity verified for all three metals tested. The most promising condition for glucagon and insulin separation was achieved by using Ni2+ as the metal ligand and desorption with a pH step gradient. Two industrial insulin-processing fractions (one glucagon-rich and the other insulin-rich) were evaluated qualitatively under these conditions, resulting in an increase in glucagon purity for both fractions with a purification factor of five for the latter.
Adsorption of Organic Compounds on Activated Carbon Derived from Peanut Shells. Potential Theory Correlation for Estimating Adsorption Capacities and Affinity Coefficients
Authors: Gonzo Elio E.
Published: June 2004

Adsorption isotherms of eight organic contaminants (acetone, pyridine, phenol, iodine, Methylene Blue, Congo Red, Reactive Navy and tannic acid) onto an activated carbon obtained from peanut shells have been studied at 22°C. The experimental data were analyzed using the Polanyi Potential Theory and the Dubinin–Astakhov equation and collapsed into one general characteristic curve. This analysis allowed the affinity coefficient for each organic compound to be obtained using phenol as the reference substance. A useful correlation for the calculation of the affinity coefficient as a function of relative parachor is presented.
Modelling Wind Turbines for Power System Dynamics Simulations: An Overview
Authors: Slootweg J. G. , Kling W. L.
Published: June 2004

Increasing amounts of wind turbines are connected to electrical power systems in order to mitigate the negative environmental consequences of conventional electricity generation. There are, however, fundamental differences between conventional and wind power generation, particularly regarding the controllability of the prime mover and the generator types used to convert mechanical energy into electricity. These differences relate to the interaction of wind turbines with the power system, including their impact on its dynamic behaviour. In order to investigate the impact of wind power on power system dynamics, adequate models are essential. However, generally accepted models for representing wind turbines in power-system dynamics simulations are presently not generally available. In this paper, various approaches and challenges for the simulation of power system dynamics are discussed and the associated modelling is analysed.
Large Scale Offshore Wind Energy in the North Sea — A Technology and Policy Perspective
Authors: Kooijman H.J.T. , de Noord M. , Uyterlinde M.A. , Wals A.F. , Herman S.A. , Beurskens H.J.M.
Published: June 2004

With the ground breaking 160 megawatt wind farm Horns Rev, off the coast of Denmark in the North Sea, installed and operating, offshore wind energy experts are progressing with optimism. With a portfolio for offshore wind farms in north-western Europe that foresees in an accumulated installed power of more than 3 gigawatt by the end of 2006, the future indeed looks bright. But will the expectations for offshore wind energy be met?

Based on experience from technical and market-orientated studies on offshore wind energy (OWE), the Energy research Centre of the Netherlands ECN concludes that the growth of OWE in the next few years will mainly be hampered by insufficient policy support, rather than by technical barriers. The realisation of the first two Dutch offshore wind farms has been delayed considerably. Towards the end of 2004, the Dutch policy will shift to a concession system for the issuing of exclusive rights for plots in the North Sea. For the tendered sites surrounding the UK coast, the financial returns appear marginal. Moreover, according to market models, the incentives for offshore wind energy in Germany are insufficient for successful competition with other electricity supplies in the liberalised European market.

The main technical challenges are the increase of turbine availability by improvement of turbine operation and maintenance (O&M) and a further reduction of wind farm array losses by innovation in turbine operation and farm layout. Focusing on The Netherlands, a significant upgrade of the grid is required to feed-in the Dutch goal of 6000 megawatt in 2020 successfully.
Wind Tunnel Study of the Interaction between Two Horizontal Axis Wind Turbines
Authors: Maeda Takao , Yokota Takeshi , Shimizu Yukimaru , Adachi Kazuhiro
Published: June 2004

Interactions between neighboring wind turbines in complex terrain are complex and many problems are still unsolved. This paper, through wind tunnel tests, investigates the interaction between two horizontal axis wind turbines (HAWTs) under two different flow patterns. The purpose of the study is to begin to obtain fundamental procedures for arranging turbines in a wind farm in a complex terrain, with no-fixed intervals between wind turbines and different wind conditions. The main factors investigated are: (1) experimental analysis of the wake behind HAWTs, (2) performance measurements of the HAWTs, and (3) detailed investigation of interaction between two HAWTs. The results include the effects of inflow velocity, turbulence intensity and turbine array on wind turbine output power as affected by the wake.
National and International Learning with Wind Power
Authors: Langniß Ole , Neij Lena
Published: June 2004

Learning is crucial for technical development, cost reduction and deployment of new energy technologies. The nature of the learning process can be either national or international, which will be crucial in the design of policy measures. In this paper the spatial scope of learning is described for the case of wind power. Based on this the rationale of national vs. international policy support is discussed. With wind power technology getting more mature, the scope of learning gets more and more international. This calls for an international coordination of public policies which are targeted on research, development and deployment. At the same time, national policies remain crucial for further deployment since sufficient budgets are only available in national frameworks. Moreover, national deployment is important to exploit national specific learning opportunities and cost reduction potentials due to better operation of plants and specifically adapted design of machines.
The Impacts of Market Liberalization on Innovation Processes in the Electricity Sector
Authors: Markard Jochen , Truffer Bernhard , Imboden Dieter M.
Published: June 2004

Market liberalization has triggered fundamental changes in the electricity sector with far-reaching economic, technical, organizational and ecological consequences. The paper examines how electricity market liberalization has influenced innovation processes at the level of electric utilities and in the electricity sector as a whole. The results are based on an empirical survey including two case studies, green power and fuel cells, in which utility innovation strategies were analysed. From the similarities in both cases and the aggregated effects of innovation strategies, we identify several indications for a general change of innovation processes in the sector: The innovation activity has increased, there is a greater variety of innovation projects, product innovations and organizational innovations have gained importance, innovation networks have become smaller and more specific, and the professionalism of innovation management is improving.
The Planned Fifth Nuclear Reactor in Finland, and its Institutional Framework
Authors: Nikula Anneli , Kätkä Martti
Published: June 2004

The institutional framework and the role of the companies are of key importance in considering an investment in new nuclear capacity in a country. In Finland, Teollisuuden Voima Oy (TVO) is a privately owned power company, which supplies electricity to its shareholders at cost. TVO received 24.5.2002 a positive decision in principle from the Finnish Parliament, which enables the construction process of a new nuclear unit. In this paper the arguments for more nuclear power and cost comparison of power generation are described. Also the capacity in Finland and Scandinavia, the need of new power plants and the political decision process of a new nuclear unit are discussed. One argument of TVO's application was the need of competitive and CO2 free generating capacity. The higher than expected growth of electricity consumption, the rise of electricity price and the increase in carbon dioxide emissions have made these arguments even more valid.
Liberalisation of the Electricity Sector and Development of Distributed Generation: Germany, United Kingdom and France
Authors: Menanteau Philippe
Published: June 2004

This paper analyses the effect of electricity sector liberalisation on the development of distributed generation. It examines the conditions in which these new electricity generating technologies can be diffused in a liberalised framework. This analysis reveals that the institutional framework in which distributed generation must operate and the price signals given to electricity sector actors play as big a part as traditional incentives, certificates, bidding systems or guaranteed feed-in tariffs in driving the deployment process.
Innovation Effects of Energy Policy Instruments in Germany
Authors: Walz Rainer
Published: June 2004

Standard environmental economics predicts that market-based policy instruments have a much more positive influence on innovation than command and control policies which are classified as hampering innovations. However, the environmental policy analysis approach from political science downplays the role of policy instruments and stresses the importance of other factors. Against this theoretical background, the paper presents the results of two case studies which analysed the effects of command and control policies in the heating sector. Based on these empirical findings, first conclusions are drawn about the role of energy policy instruments in shaping innovation.
Policy Instruments for Supporting Energy Efficiency in Poland
Authors: Wyrwa Artur , Figœrski Arkadiusz , Gula Adam
Published: June 2004

The paper contains discussion of the impact of different policy instruments on energy efficiency improvements, based on practical experience following from several projects realised in Poland with the Authors' involvement. The paper also describes the present policy in the area of rational use of heat energy in Poland based on the Thermal Modernisation Act of 1998.
Olfactory Horizontal Basal Cells Demonstrate a Conserved Multipotent Progenitor Phenotype
Authors: Carter Lindsay A. , MacDonald Jessica L. , Roskams A. Jane
Published: June 2004

Stem cells of adult regenerative organs share a common goal but few established conserved mechanisms. Within the neural stem cell niche of the mouse olfactory epithelium, we identified a combination of extracellular matrix (ECM) receptors that regulate adhesion and mitosis in non-neural stem cells [intercellular adhesion molecule-1 (ICAM-1), β1, β4, and α-1, -3, and -6 integrins] and on horizontal basal cells (HBCs), candidate olfactory neuro-epithelial progenitors. Using ECM receptors as our guide, we recreated a defined microenvironmentin vitrothat mimics olfactory basal lamina and, when supplemented with epidermal growth factor, transforming growth factor α, and leukemia inhibitory factor, allows us to preferentially expand multiple clonal adherent colony phenotypes from individual ICAM-1+ and ICAM-1+/β1integrin+-selected HBCs. The most highly mitotic colony-forming HBCs demonstrate multipotency, spontaneously generating more ICAM-positive presumptive HBCs, a combination of olfactory neuroglial progenitors, and neurons of olfactory and potentially nonolfactory phenotypes. HBCs thus possess a conserved adhesion receptor expression profile similar to non-neural stem cells, preferential self-replication in anin vitroenvironment mimicking theirin vivoniche, and contain subpopulations of cells that can produce multiple differentiated neuronal and glial progeny from within and beyond the olfactory systemin vitro.
Stroke Transiently Increases Subventricular Zone Cell Division from Asymmetric to Symmetric and Increases Neuronal Differentiation in the Adult Rat
Authors: Zhang Ruilan , Zhang Zhenggang , Zhang Chunling , Zhang Li , Robin Adam , Wang Ying , Lu Mei , Chopp Michael
Published: June 2004

The orientation of mitotic cleavage regulates neurogenesis during neural development. We examined the orientation of mitotic cleavage of dividing progenitor cells in the subventricular zone (SVZ) of adult rats subjected to stroke. In nonstroke rats, 55% of dividing cells were oriented horizontally, whereas 40% were oriented vertically. Horizontal and vertical cleavage orientations produce asymmetric and symmetric divisions, respectively. Four days after stroke, the number of dividing cells increased twofold, whereas the proportion of symmetric dividing cells significantly (p< 0.01) increased from 40% before stroke to 60%. Fourteen days after stroke, the percentage of symmetric dividing cells was 47%. Stroke-increased numbers of dividing cells in M-phase were confirmed by immuostaining. In nonstroke rats, 37 and 33% of symmetric and asymmetric dividing cells, respectively, exhibited a neuronal marker (TuJ1). Four days after stroke, rats exhibited a significant (p< 0.05) augmentation of the frequency (47%) of neuronal distribution showing TuJ1 immunoreactivity in cells with symmetric division but not cells with asymmetric division (33%). Numb immunoreactivity was detected in SVZ cells of nonstroke rats. Stroke did not change Numb distribution. Our data suggest that neurons are produced by both asymmetric and symmetric cell divisions in the adult SVZ, and the transient increases in symmetric division and neuronal differentiation may result in stroke-induced neurogenesis.
Distinctive Responses in the Medial Amygdala to Same-Species and Different-Species Pheromones
Authors: Meredith Michael , Westberry Jenne M.
Published: June 2004

Chemosignals related to reproductive and social status (pheromones) carry messages between opposite-sex and same-sex individuals in many species. Each individual must distinguish signals relevant to its own social behavior with conspecifics from signals used by other (heterospecific) species relevant to their social behavior. In male hamsters, the medial amygdala responded in a categorically different way to conspecific stimuli (socially relevant) and heterospecific stimuli (not socially relevant but serving similar purposes for other species), and may play an important role in this decision. Immediate-early gene responses to conspecific chemosignals and heterospecific chemosignals were characteristically different. The categorical responses, generated by chemosensory input from the vomeronasal organ and (probably) GABA inhibition within the amygdala, were not apparent at more peripheral sensory levels. This is the first evidence for an important role of the amygdala, a limbic structure known to be involved in social and emotional behavior, in discrimination of species specificity in chemosignals.
Widespread Expression of the AMPA Receptor GluR2 Subunit at Glutamatergic Synapses in the Rat Spinal Cord and Phosphorylation of GluR1 in Response to Noxious Stimulation Revealed with an Antigen-Unmasking Method
Authors: Nagy Gergely G. , Al-Ayyan Muna , Andrew David , Fukaya Masahiro , Watanabe Masahiko , Todd Andrew J.
Published: June 2004

Glutamate, the principal excitatory neurotransmitter in the spinal cord, acts primarily through AMPA receptors. Although all four AMPA subunits are expressed by spinal neurons, we know little about their distribution at glutamatergic synapses. We used an antigen-unmasking technique to reveal the synaptic distribution of glutamate receptor (GluR) 1-4 subunits with confocal microscopy. After pepsin treatment, punctate staining was seen with antibodies against each subunit: GluR2-immunoreactive puncta were distributed throughout the gray matter, whereas GluR1-immunoreactive puncta were restricted to the dorsal horn and were most numerous in laminas I-II. Punctate staining for GluR3 and GluR4 was found in all laminas but was weak in superficial dorsal horn. Colocalization studies showed that GluR2 was present at virtually all (98%) puncta that were GluR1, GluR3, or GluR4 immunoreactive and that most (>90%) immunoreactive puncta in laminas IV, V, and IX showed GluR2, GluR3, and GluR4 immunoreactivity.

Evidence that these puncta represented synaptic receptors was obtained with electron microscopy and by examining the association of GluR2- and GluR1-immunoreactive puncta with glutamatergic boutons (identified with vesicular glutamate transporters or markers for unmyelinated afferents). The great majority (96%) of these boutons were associated with GluR2-immunoreactive puncta. Our findings suggest that GluR2 is almost universally present at AMPA-containing synapses, whereas GluR1 is preferentially associated with primary afferent terminals.

We also found a substantial, rapid increase in staining for synaptic GluR1 subunits phosphorylated on the S845 residue in the ipsilateral dorsal horn after peripheral noxious stimulation. This finding demonstrates plastic changes, presumably contributing to central sensitization, at the synaptic level.
Erlössteigernde Verkaufssteuerung durch Absatzgrenzen für Logistikdienste mit mehreren knappen Ressourcen (Network Revenue Management for Logistics Services Based on Booking Limits)
Authors: Kimms Alf , Müller-Bungart Michael
Published: June 2004

Beim Verkauf von Nutzungsrechten für terminlich gebundene knappe Kapazitäten (z.B. beim Verkauf von Flugtickets (Transportkapazitäten) oder bei der Reservierung von Hotelzimmern (Lagerkapazitäten)) ist die zukünftige Nachfrage in aller Regel nicht mit Sicherheit bekannt. Unterscheiden sich Kunden bezüglich der Nachfragemengen oder Preisbereitschaften, dann ist die spontan zu treffende Entscheidung, ob eine Kundennachfrage erfüllt oder ob sie in der Hoffnung auf höherwertige Nachfrage abgelehnt werden soll, nicht trivial. Dieser Beitrag diskutiert Aspekte, wie in derartigen Situationen der Verkauf über sog. Absatzgrenzen so gesteuert werden kann, dass der erwartete Erlös maximal ist.
Transport of momentum and energy in a ducted jet: III. Correlation of profiles of total momentum and energy flux in a nonisothermal jet discharging into a duct
Authors: Alexander L. G. , Kivnick Arnold , Comings E. W. , Henze E. D.
Published: June 2004

The data in the first paper of this series on the distribution of momentum and energy in nonisothermal air streams mixing in a straight duct were correlated by the methods described in the second paper. Mixing indexes were evaluated and used to correlate profiles of total momentum and stagnation temperature at various sections of the duct.
Laws of corresponding states
Authors: Nelson L. , Obert E. F.
Published: June 2004

Various laws of corresponding states are examined briefly in this paper to show the corrections that are in common use to increase the accuracy of forecasting compressibility factors. Two trends are noticeable: (I) the use of specific compressibility charts with the results generalized for all gases either by corrections related to 𝓏 (the compressibility factor at the critical point) or by the use of pseudocritical properties and (2) the use of a true generalized chart based upon averaged data. It is shown that the selection of the plot parameters affects the accuracy of the generalized chart. In recent years reduced parameters based upon kinetic theory have been proposed but for a restricted class of gases (nonpolar gases with spherically symmetrical molecules and negligible quantum effects). It is shown that the kinetic parameters are directly related to the critical constants and also that the kinetic parameter charts can be used for all gases without serious loss of accuracy.
Enthalpy‐Concentration diagrams of binary aqueous mixtures of hydrazine, sodium carbonate, and glycerine
Authors: Tyner Mack
Published: June 2004

Generally an enthalpy‐concentration diagram for a system is prepared for fixed pressure, and to be complete it should include data on the solid, liquid, and vapor phases. Such charts are useful for calculations involving heat balances with accompanying concentration changes. This article outlines the steps in the preparation of a diagram and includes the diagrams for aqueous solutions of hydrazine, sodium carbonate, and glycerine.
Enrichment calculations in gaseous diffusion: Large separation factor
Authors: Naylor Robert W. , Backer Paul O.
Published: June 2004

A general method has been devised for calculating gaseous‐diffusion‐stage requirements to separate gases of widely differing molecular weights. For such a mixture the actual separation factor is shown to be less than the ideal separation factor, depending on the undiffused‐gas composition and the ratio of absolute pressures on each side of the barrier. The equilibrium relationship between the compositions of the diffused‐ and undiffused‐gas streams leaving any stage is also derived by means of the Rayleigh concept. Application of the method is illustrated with a diagram, like that of McCabe and Thiele for distillation, on which are stepped off the required number of theoretical stages to separate a particular hydrogen‐nitrogen mixture.
Controlling mechanism in the aqueous absorption of nitrogen oxides
Authors: Peters M. S. , Ross C. P. , Klein J. E.
Published: June 2004

The reactions involved in the removal of nitrogen oxides from gases by reaction with water are reversible and proceed at a finite rate. It is possible therefore that the over‐all process is controlled by the rate of the chemical reactions. On this basis an analysis of the process has been developed by the application of chemical kinetics, with consideration of reactions involving both nitrogen dioxide and dinitrogen tetroxide. The resulting differential equation has been simplified and integrated to give a final equation which can be tested experimentally.

Theoretical methods are presented for predicting the extent of absorption of nitrogen oxides at various gas rates and concentrations and are compared with the experimental results.

The paper presents some new concepts of the factors which control the rate of absorption of nitrogen dioxide and dinitrogen tetroxide in water. An understanding of the controlling factors in the process should indicate methods for improving the design of absorption towers in nitric acid plants and aid in the design of scrubbers for removing nitrogen oxides from waste gases.
Approximate equations for time of batch fractionation
Authors: Johnson A. I. , Huang Chen‐Jung , Talbot F. D. F.
Published: June 2004

Analytical expressions are obtained for the calculation of the time required for batch rectification of binary feeds which may be treated by assuming constant relative volatility and no column holdup. The equations cover constant reflux operations and varying reflux constant product operations for the two cases involving either a large or a small number of theoretical stages. The latter type of calculation has hitherto been possible only by tedious graphical methods. This paper introduces novel pseudoequilibrium curves which lead to simple equations of considerable accuracy. The equations obtained may be rearranged or modified so that other factors such as sharpness of fractionation may be represented analytically.
Gas absorption and oxidation in dispersed media
Authors: Andersen L. B. , Johnstone H. F.
Published: June 2004

The absorption and subsequent liquid‐phase reaction of oxygen was studied with two types of dispersion apparatus, the Venturi atomizer and the fritted‐glass disperser. The systems studied in both devices included the absorption of atmospheric oxygen by catalyzed sodium sulfite solutions and the simultaneous absorption of atmospheric oxygen with nitrogen dioxide and with sulfur dioxide by water.

Very large values of the liquid‐film mass transfer coefficient for oxygen absorption were measured in the atomization zone of the Venturi atomizer. Over‐all recovery efficiencies were less than 2.3% for nitrogen dioxide but reached as much as 22% for sulfur dioxide. Oxidation efficiencies for sodium sulfite solutions ranged up to 80%, depending on the operating conditions.

The fritted‐glass disperser gave recovery efficiencies of nitrogen dioxide as high as 90% from air containing 10% of the gas. The recovery efficiency decreased at low concentrations of nitrogen dioxide for both the Venturi atomizer and the fritted‐glass disperser.
Critical constants of saturated aliphatic hydrocarbons
Authors: Thodos George
Published: June 2004

Through the use of group contributions the van der Waals' constants, a and b, were estimated for a number of saturated aliphatic hydrocarbons from a knowledge of the chemical structure of these compounds and were used to define the critical temperature and pressure of these substances.

By the use of methane as the base group, both van der Waals' constants were estimated for a number of saturated aliphatic hydrocarbons of considerable size and complexity through the additive contribution of methyl groups in the seccessive substitution of hydrogen until the desired structure of the substance was obtained. For the normal saturated hydrocarbons these contributions were found to be additive for the evaluation of a0.626 and b0.76 up through n‐octane, and these exponents have been assumed to apply in the scaling up of larger normal and isomeric hydrocarbon molecules for which experimental data are lacking.

The volume van der Waals' constant b alone serves to define the critical volume of these compounds through the expression γc = 3 β b, where β represents a factor which has been found to depend on the size and arrangement of the molecule.

By following this procedure the critical temperatures, pressures and volumes of the normal saturated hydrocarbons through eicosane (C20H42), inclusive, and all the isomeric hydrocarbons up to and through the nonanes were calculated and compared, whenever possible, with values already available in the literature with an agreement of 0.43% for the estimation of the critical temperature, 0.69% for the critical pressure, and 0.86% for the critical volume. A combined consideration of these average deviations points to the estimation of the critical constants of the aliphatic saturated hydrocarbons with an average error of 0.7%.
Studies of thermal conductivity of liquids. Part I
Authors: Sakiadis Byron C. , Coates Jesse
Published: June 2004

Values of thermal conductivity and temperature coefficients for fifty‐three pure organic liquids, obtained with newly designed, extensively tested apparatus, are presented. For thirty‐one of these liquids values of thermal conductivity or temperature coefficients have not been previously reported. The statisically determined maximum error in the presented values of thermal conductivity of liquids is ±1.50%.

A method of correlating the thermal conductivity of liquids based on a modified statement of the theory of corresponding states is presented. Group contributions to the thermal conductivity were calculated. The thermal conductivity of liquids was predicted by this method and the average deviation of the calculated from the observed values for forty‐seven liquids is ±1.50%. The proposed method of correlation permits the calculation of the thermal conductivity of a series of liquids at any temperature from a single known value.
Liquid‐liquid extraction in continuous‐flow agitated extractors
Authors: Flynn A. W. , Treybal R. E.
Published: June 2004

Extraction studies were made with the systems toluene water benzoic acid and kerosene water benzoic acid in two dimensionally similar cylindrical extractors, one 6 in. in diameter by 6 in. high, the other 12 in. in diameter by 12 in. high. Each extractor contained four radial baffles, of width equal to 16.7% of the extractor diameter. The extractors were agitated by six‐bladed dimensionally similar turbine impellers, the diameters of which were in each case one third the diameter of the extractor.

When the extractors were full of liquid, i.e., in the absence of an air‐liquid interface, the power required for a given impeller speed was independent of the rate of flow of liquid. However, such operation required more power than the equivalent open‐tank agitator, and more baffling was required to produce fully turbulent flow.

Flow rates were varied from 0 to 4,000 lb./hr. and solvent‐to‐water mass ratios from 3:1 to 1:6. Extraction stage efficiencies were found to be appreciable even at zero agitator speed.

The additional stage efficiency produced by agitation was found to be a function of the power input per unit volume of liquid flowing. This relationship permitted the correlation of all extraction efficiency data for a given system at a constant solvent‐to‐water ratio over eight‐fold range of power input. It was found possible to predict the performance of an extractor in continuous flow from batch‐extraction measurements through the methods of MacMullin and Weber.
Diffusion coefficients in hydrocarbon systems: n‐Hexane in the gas phase of the methane—, ethane—, and propane—n‐hexane systems
Authors: Carmichael L. T. , Sage B. H. , Lacey W. N.
Published: June 2004

Experimental information concerning the molecular transport of the lighter hydrocarbons in the gas phase is limited. For this reason a study was made of the Maxwell diffusion coefficients of n‐hexane in the gas phase of the methane‐n‐hexane, and propane‐n‐hexane systems.

Maxwell diffusion coefficients were determined at steady state for pressures up to 70 lb./sq. in. at temperatures between 70° and 220° F. The effects of interfacial resistance were considered and uncertainties as to the behavior at the end of the transport path were eliminated. Coefficients were reported with partial pressure and with fugacity as the potential. Fick diffusion coefficients were calculated for each component on the assumption that the gas phase was an ideal solution.

These data indicated that the Maxwell hypothesis with fugacity as the potential in an ideal solution is a fair description of the transport characteristics of the lighter hydrocarbons in the gas phase at relatively low pressures. A regular decrease in the Maxwell diffusion coefficient with an increase in the molecular weight of the stagnant component was observed.
Dispersed‐phase holdup in packed, countercurrent liquid‐liquid extraction columns
Authors: Wicks C. E. , Beckmann R. B.
Published: June 2004

This investigation is a study of the effect of flow rates and packing size and column diameter upon the holdup of a toluene dispersed phase, flowing countercurrent to a continuous water phase in packed liquid‐liquid extraction columns. Six different packings were used: ¼‐, ⅜‐, ½‐, ⅝‐, ¾‐, and 1‐in. nonporous, unglazed‐porcelain Rasching rings. Three extraction columns, 3, 4, and 6 in. I. D., were used in the experimental work.

Three types of dispersed‐phase holdup, free, operational, and total, have been investigated. An empirical correlation is presented for the total holdup data below the loading point. A correlation of the effect of packing size on the exponential term r and the coefficient A1 is developed for packing sizes 1/2 in. or larger when the column‐diameter‐to‐packing‐size ratio is at least 8 to 1. The term A1(VD)r in the equation accounts for at least 90% of the total holdup. The small magnitude of the residual term B1(VD) (VC8) did not permit a definite correlation of the coefficient B1 or the exponent s.

Observation of the dispersed‐phase holdup during column operation revealed a transitional behavior of the 3/8‐in. rings as compared with that of the 1/4‐ and 1/2‐in. or larger packing. Two, and sometimes three, regimes of flow occur in packed extraction columns. the increase in holdup with increasing continuous‐phase flow rate differed for each zone. In the two zones below the loading zone the holdup was found to increase linearly with the dispersed‐phase flow rate for a constant continuous‐phase flow rate. A new method of randomly packing an extraction column has been found to give reproducible holdup data.
Continuous reactions in distillation equipment
Authors: Belck Lothar H.
Published: June 2004

For hypothetical two‐ and three‐component liquid‐phase reversible reactions, continuous processes are described in which the products are obtained in essentially pure form by carrying out the reaction in a single distillation column. Methods for plate‐to‐plate calculations in such reaction‐distillation systems and numerical solutions for two reactions are presented.
Heat transfer to water in an annulus
Authors: Miller Philip , Byrnes James J. , Benforado David M.
Published: June 2004

A limited number of measurements were made of the heat transfer coefficient from an electrically heated rod to water flowing in an annulus. Tests were performed at Reynolds numbers ranging from 5,000 to 22,000 (based on equivalent diameter), water temperatures of 70° and 125°F., and relatively high heat fluxes of 52,000 to 208,000 B.t.u./(hr.) (sq. ft.). The annulus dimensions were 0.625 in. I.D. and 0.840 in. O.D. The coefficients varied as the 0.8 power of the velocity; they were 20% higher than predicted by use of Colburn's equation for flow inside pipes with the equivalent diameter. Over the range of conditions studied, it was found that the thermal boundary layer was fully developed in 1 1/8 in. (Lh/De=5).
Entrainment from bubble‐cap trays
Authors: Atteridg P. T. , Lemieux E. J. , Schreiner W. C. , Sundback R. A.
Published: June 2004

Data on liquid entrainment are reported for rectangular‐cap bubble trays on 24‐in. tray spacing for an air‐water system. Several tray variations were studied, and entrainment is given for trays containing eight, twelve, and sixteen caps a tray. Some hydraulic characteristics (pressure drop, liquid backup, minimum vapor velocity, and downflow froth height) are also reported. It was found in this study that decreasing liquid path lenght increased the entrainment from a bubble‐cap tray and increasing tray bubbling area decreased entrainment. It was also found that decreasing slot area generally had no effect on liquid entrainment over the range investigated.
Rate of nitration of benzene with mixed acid
Authors: Biggs R. D. , White R. R.
Published: June 2004

The rates of nitration of benzene by nitric acid in mixed acid to produce mononitrobenzene have been measured in well‐emulsified reaction mixtures in the temperature range from 34° to 54°C. The acid‐phase compositions ranged from 1.6 mole % nitric acid and 27 mole % sulfuric acid to 35 mole % nitric acid and zero % sulfuric acid; the organicphase composition ranged from 4 to 95 mole % benzene, and the relative extent of the acid and organic phases was varied from 25 to 80 volume % acid phase.

The reaction rate based on the total volume of the reacting mixture is shown to be a function of the phase compositions, temperature, and volume % of acid phase.
Prediction of ideal‐stage requirements in complex liquid‐liquid extraction systems
Authors: Peterson H. C. , Beyer G. H.
Published: June 2004

A procedure for obtaining equilibrium data and predicting ideal‐stage requirements in a complex liquid‐liquid extraction system is presented. Preliminary equilibrium data are obtained from a simulated column run involving a series of batch contacts operated in such a manner as to approach steady state countercurrent conditions. The flow ratios and stage requirements for continuous operation are then estimated by trial‐and‐error by use of a modified McCabe‐Thiele method.

The procedure lends itself particularly well to those systems with interdependent distribution of the two components. Data for the separation of hafnium from zirconium are presented to show the utility of the method.