Symmetric spectrum current drive due to finite radial drift effects

2018 ◽  
Vol 84 (6) ◽  
Author(s):  
Peter J. Catto
Keyword(s):  
Adjoint Method ◽  
Economic Cost ◽  
Reactor Power ◽  
Current Drive ◽  
Alpha Particles ◽  
Electron Drag ◽  
The Difference ◽  
Counter Current ◽  
Symmetric Spectrum ◽  
Very High

The drift surfaces of minority heated ions differ from flux surfaces due to finite poloidal gyroradius effects. As the minority poloidal gyroradius approaches radial scale lengths in the plasma, the difference between drift and flux surfaces can modify the heating and lead to a symmetric spectrum minority counter-current being driven. In response, a corresponding overall net co-current of comparable size is driven. This beneficial symmetric spectrum current drive in a tokamak is due to the parallel velocity asymmetry in the drift departure from a flux surface. As this new source of driven current is a side effect of minority heating it comes without any additional economic cost to reactor power balance. The symmetric spectrum current driven for near Maxwellian minorities is evaluated by an adjoint method and found to be modest. However, minority heating typically results in strong non-Maxwellian features on minority distributions so it may be possible to drive a significantly larger co-current. A related evaluation is performed for alpha particles in a deuterium minority heated plasma with a tritium majority. The low density of the alphas tends to keep this driven symmetric spectrum current small, but at very high heating levels a significant co-current might be driven. Other mechanisms to drive co-current with a symmetric spectrum are discussed and estimated, including asymmetric electron drag and focusing of the applied minority heating radio frequency fields.

The metachor as a characteristic of the association of electrolytes in aqueous solutions

1984 ◽  
Vol 49 (5) ◽  
pp. 1061-1078 ◽  
Author(s):  
Jiří Čeleda ◽  
Stanislav Škramovský
Keyword(s):  
Aqueous Solutions ◽  
Apparent Volume ◽  
Solutions Of Electrolytes ◽  
Molal Volumes ◽  
The Difference ◽  
High Concentrations ◽  
Experimental Values ◽  
Suitable Characteristic ◽  
Association Of Ions ◽  
Very High

Based on the earlier paper introducing a concept of the apparent parachor of a solute in the solution, we have eliminated in the present work algebraically the effect which is introduced into this quantity by the additivity of the apparent molal volumes. The difference remaining from the apparent parachor after substracting the contribution corresponding to the apparent volume ( for which the present authors suggest the name metachor) was evaluated from the experimental values of the surface tension of aqueous solutions for a set of 1,1-, 1,2- and 2,1-valent electrolytes. This difference showed to be independent of concentration up to the very high values of the order of units mol dm-3 but it was directly proportional to the number of the free charges (with a proportionality factor 5 ± 1 cm3 mol-1 identical for all studied electrolytes). The metachor can be, for this reason, a suitable characteristic for detection of the association of ions and formation of complexes in the solutions of electrolytes, up to high concentrations where other methods are failing.

Quality-of-Life Measurement in Advanced Cancer: Assessing the Individual

1999 ◽  
Vol 17 (11) ◽  
pp. 3603-3611 ◽  
Author(s):  
Dympna Waldron ◽  
Ciaran A. O'Boyle ◽  
Michael Kearney ◽  
Michael Moriarty ◽  
Desmond Carney
Keyword(s):  
Quality Of Life ◽  
Advanced Cancer ◽  
Internal Validity ◽  
Semistructured Interview ◽  
Incurable Cancer ◽  
Life Measurement ◽  
The Difference ◽  
The Individual ◽  
Very High

PURPOSE: Despite the increasing importance of assessing quality of life (QoL) in patients with advanced cancer, relatively little is known about individual patient's perceptions of the issues contributing to their QoL. The Schedule for the Evaluation of Individual Quality of Life (SEIQoL) and the shorter SEIQoL–Direct Weighting (SEIQoL-DW) assess individualized QoL using a semistructured interview technique. Here we report findings from the first administration of the SEIQoL and SEIQoL-DW to patients with advanced incurable cancer. PATIENTS AND METHODS: QoL was assessed on a single occasion using the SEIQoL and SEIQoL-DW in 80 patients with advanced incurable cancer. RESULTS: All patients were able to complete the SEIQoL-DW, and 78% completed the SEIQoL. Of a possible score of 100, the median QoL global score was as follows: SEIQoL, 61 (range, 24 to 94); SEIQoL-DW, 60.5 (range, 6 to 95). Psychometric data for SEIQoL indicated very high levels of internal consistency (median r = .90) and internal validity (median R2 = 0.88). Patients' judgments of their QoL were unique to the individual. Family concerns were almost universally rated as more important than health, the difference being significant when measured using the SEIQoL-DW (P = .002). CONCLUSION: Patients with advanced incurable cancer were very good judges of their QoL, and many patients rated their QoL as good. Judgments were highly individual, with very high levels of consistency and validity. The primacy given to health in many QoL questionnaires may be questioned in this population. The implications of these findings are discussed with regard to clinical assessment and advance directives.

scholarly journals Phylogeographic Structure of White Oaks Throughout the European Continent

Genetics ◽  
1997 ◽  
Vol 146 (4) ◽  
pp. 1475-1487 ◽  
Author(s):  
S Dumolin-Lapègue ◽  
B Demesure ◽  
S Fineschi ◽  
V Le Come ◽  
R J Petit
Keyword(s):  
Statistical Approach ◽  
Restriction Analysis ◽  
Phylogeographic Structure ◽  
White Oak ◽  
European Continent ◽  
The Balkans ◽  
Left Behind ◽  
The Difference ◽  
Mantel’S Test ◽  
Very High

Patterns of chloroplast DNA (cpDNA) variation were studied in eight white oak species by sampling 345 populations throughout Europe. The detection of polymorphisms by restriction analysis of PCR-amplified cpDNA fragments allowed the identification of 23 haplotypes that were phylogenetically ordered. A systematic hybridization and introgression between the eight species studied is evident. The levels of subdivision for unordered (G  ST) and ordered (N  ST) alleles are very high and close (0.83 and 0.85). A new statistical approach to the quantitative study of phylogeography is presented, which relies on the coefficients of differentiation G  ST and N  ST and the Mantel's test. Based on pairwise comparisons between populations, the significance of the difference between both coefficients is evaluated at a global and a local scale. The mapped distribution of the haplotypes indicates the probable routes of postglacial recolonization followed by oak populations that had persisted in southern refugia, especially in the Iberian peninsula, Italy and the Balkans. Most cpDNA polymorphisms appear to be anterior to the befinnina of the last recolonization. A subset of the preexisting haplotypes have merely expanded north, while others were left behind in the south.

scholarly journals Hyperfine structure in the arc spectrum of cæsium and nuclear rotation

1928 ◽  
Vol 121 (787) ◽  
pp. 432-447 ◽  
Keyword(s):  
Hyperfine Structure ◽  
Nuclear Spin ◽  
High Frequency ◽  
Principal Series ◽  
Very High Frequency ◽  
Nuclear Rotation ◽  
Higher Temperature ◽  
The Difference ◽  
Mechanical Moment ◽  
Very High

The arc spectrum of cæsium was investigated with the object of finding whether any of its lines possessed hyperfine structure, resulting from a nuclear magnetic moment, due to a quantised nuclear spin. The lines belonging to the principal series should, owing to the greater degree of penetration of the electron in the (1 s or 6 1 ) orbit, and the correspondingly greater interaction, show the greatest effect. The lines of the principal series are very easily broadened if the vapour pressure of the metal becomes high, so that great care had to be used in obtaining the spectrum of cæsium at a sufficiently low temperature. The most satisfactory method of excitation was found to be the application by means of external electrodes of a very high frequency alternating current to a tube filled with helium at about 2 mm. pressure containing a small quantity of cæsium. The tube required slight heating to bring out the cæsium lines; without this the helium spectrum was very much stronger than the metallic spectrum. At a very low vapour pressures of cæsium the discharge was blue in colour. Under these conditions the lines of the principal series showed no broadening greater than that due to thermal agitation, but at a slightly higher temperature the colour of the discharge became purple and the lines broadened. The lines belonging to the principal series were found to be very close doublets with very nearly constant frequencies differences. A theory is worked out which explains the origin of these doublets, assuming a nuclear spin of one half quantum; by correlating the difference in the separation of the hyperfine structure doublets in the 1 s — m 2 p 3/2 lines and the 1 s — m 2 p 1/2 lines, it is shown that a ratio of the magnetic to the mechanical moment of the nucleus about twice as great as the corresponding ratio for the electron would account for the observed frequency differences. The spectral notation used throughout is that of Hund. The results are compared with those found for the hyperfine structure of some of the bismuth lines by Back and Goudsmid, and are found to be in satisfactory agreement. A selection principle is found which applies both to the bismuth and the cæsium spectrum.

scholarly journals Has the Propensity to Pay Dividends Declined? Evidence from the US Banking Sector

2021 ◽  
Vol 14 (3) ◽  
pp. 103
Author(s):  
Shaojie Lai ◽  
Qing Wang ◽  
Jiangze Du ◽  
Shuwen Pi
Keyword(s):  
Banking Sector ◽  
Logit Models ◽  
Sample Period ◽  
Financial Firms ◽  
The Us ◽  
The Difference ◽  
High Level ◽  
Propensity To Pay ◽  
Financial Firm ◽  
Very High

This article examines the propensity to pay dividends in the U.S banking sector during 1973–2014. Although the propensity to pay dividends has been declining over the 52 years of our sample period, banks are consistently more likely to pay dividends than non-financial firms. Using the coefficients from logit models estimated early in the sample period to forecast the percentage of dividend payers in each subsequent year, we conclude that there has been a decline in the likelihood of paying dividends in the banking sector. However, the decline started from a very high level as compared to that of the non-banking sectors. In addition, the variables taken from the non-financial firm literature do not explain the difference between the actual and expected percentage of dividend payers in the banking sector. We also conduct exploratory analyses with bank-specific variables. Although newly included variables are significantly related to the likelihood of paying dividends, they do not explain the declining propensity to pay dividends in the banking sector.

Distribution of Oxygen Tension in the Blood and Water Along the Secondary Lamella of the Icefish Gill

1972 ◽  
Vol 56 (2) ◽  
pp. 481-492
Author(s):  
G. M. HUGHES
Keyword(s):  
Current Flow ◽  
Dissociation Curve ◽  
Exchange Area ◽  
Gill Area ◽  
Secondary Lamella ◽  
Oxygen Tensions ◽  
Counter Current ◽  
O2 Dissociation Curve ◽  
Very High ◽  
O2 Transfer

1. Measurements of the gill area of two specimens of Chaenocephalus aceratus indicate that the resistance to water flow and overall exchange area are even less than had been supposed from work with other icefish. 2. Measurements of the oxygen tensions in the water and in blood entering and leaving the gills are used to determine the expected distribution of O2 tensions along a typical secondary lamella profile. The advantage of counter-current over co-current flow is clearly indicated by such analyses. 3. The absence of complications due to the O2 dissociation curve of the blood facilitates an extension of the analysis to different theoretical secondary lamellar profiles. It is shown that profiles similar to those usually found in fish gills are more efficient in maintaining O2 transfer. 4. Although the percentage utilization of O2 in the water passing through the gills is relatively low, the effectiveness of oxygenating the blood is very high in the icefish gill.

Producing Steam by Spraying Water on a Heated Bed of Steel Spheres

2021 ◽  
pp. 1-42
Author(s):  
D. Jordan Bouchard ◽  
HengSheng Yang ◽  
Sanjeev Chandra
Keyword(s):  
Particle Size ◽  
Thermal Mass ◽  
Steam Generation ◽  
Bed Porosity ◽  
The Media ◽  
Effect Of Particle Size ◽  
The Difference ◽  
Rate Of Evaporation ◽  
A Minor ◽  
Counter Current

Abstract Steam generators used in industrial baking ovens operate by pouring or spraying water on a preheated thermal mass. This paper presents a methodology to quantify the amount of steam generated from a thermal mass along with experiments to determine the effect of particle size and porosity on steam generation. Three sizes of steel spheres, 0.6 mm, 8 mm, and 16 mm in diameter, were used to construct porous media beds that were preheated in an oven after which water was sprayed onto them from a full-cone nozzle for a fixed duration. The weight of the heated bed and the impinging water were recorded during spraying. The difference in weight change when spraying on heated and unheated beds gave the rate of evaporation. Thermocouples were used to record the internal temperature of the bed. Steam generation rate increased with particle size while bed porosity had only a minor influence. The counter-current flow of steam within the media bed disrupts the downward flow of water enough to leave pockets of hot material, reducing steam production. To maximize steam generation the media size, material, and spray time should be matched to ensure the surfaces of particles remain above the boiling point of water during spraying.

The economic and financial viability of sheltered employment centres

2019 ◽  
Vol 57 (9) ◽  
pp. 2261-2283
Author(s):  
Vera Gelashvili ◽  
Eva María Aguilar Pastor ◽  
María-Jesús Segovia-Vargas ◽  
Maria-del-Mar Camacho-Miñano
Keyword(s):  
Training Programs ◽  
Similar Response ◽  
Economic Returns ◽  
Content Type ◽  
Strategic Plans ◽  
Low Levels ◽  
The Difference ◽  
Practical Implications ◽  
Very High

Purpose The purpose of this paper is to investigate whether sheltered employment centers (CEEs) which have a higher rate of professionalization of their managers have better economic returns than those that have a lower one. Design/methodology/approach A questionnaire has been drawn up for their managers. After collecting the answers, an index of professionalization classifies the CEEs with managers of high, medium and low levels of professionalism. This index is then correlated with the main financial ratios of companies. Findings The results show that companies with the highest level of managers’ professionalization, on average, have higher economic returns than companies with medium and low rates, although the difference is not very high. This study is an important contribution to academic literature, as it is the first to examine the professionalization of CEE managers. Research limitations/implications Finally, this paper is not short of limitations. The number of responses is small but there are similar studies with similar response rates. Additionally, the scarcity of responses may suggest that there is a lack of interest about the utility of professionalization by some CEEs managers because, perhaps, they do not have the necessary competences to understand its importance in management. Practical implications This study has some main implications for stakeholders: first, CEEs must pay more attention to the professionalization of their management team, because professionalization can lead to meeting its goals and guaranteeing the firm’s growth. Second, training programs in skills and attitudes should be designed to strengthen these competencies. Moreover, managers of social firms should know that the establishment of strategic plans will be useful to identify new opportunities in the market. Social implications Given the important role of these social firms for the employment of people with disabilities, training programs should be promoted by government in order to ensure the professionalization of these companies. Originality/value This research is an important contribution to the literature on this subject because there are no studies about the level of professionalization of CEEs, companies that represent an important value for the economy of a country.

scholarly journals RECIRCULACIÓN DE LÍQUIDOS RESIDUALES EN LA CONVERSIÓN DE ALGINATO DE CALCIO EN ÁCIDO ALGÍNICO DURANTE EL PROCESO DE PRODUCCIÓN DE ALGINATOS

2005 ◽  
Vol 20 (1-2) ◽  
pp. 1
Author(s):  
Y. E. Rodríguez-Montesinos ◽  
G. Hernández-Carmona ◽  
D. L. Arvizu-Higuera
Keyword(s):  
Calcium Alginate ◽  
Alginic Acid ◽  
Current System ◽  
Macrocystis Pyrifera ◽  
Alginate Production ◽  
Yield And Quality ◽  
Alginate Fibers ◽  
Counter Current ◽  
Very High

Se estudió el efecto de recircular la solución ácida residual en la etapa de conversión de alginato de calcio en ácido algínico, utilizando el alga Macrocystis pyrifera . Los líquidos residuales fueron reciclados en un sistema en contra corriente, con lo cual se logró procesar tres cargas de alginato de sodio con el mismo volumen de agua, permitiendo una conversión efectiva en ácido algínico, con una reducción del 56% en el consumo de agua dulce. Se experimentó un sistema de recirculación en línea (sin reemplazo de agua), este sistema no es recomendable, debido a que la acumulación de calcio en el alginato después de la segunda recirculación, produce una viscosidad aparente muy alta, con un porcentaje de reducció superior al 50%. Se determinó el efecto del número de lavados ácidos del ácido algínico sobre la calidad y rendimiento del alginato obtenido. El tratamiento ácido se llevó a cabo con tres, dos y un lavado. Se concluye que se requieren tres lavados de las fibras de alginato de calcio para lograr una conversión efectiva en ácido algínico, pero el primero y segundo lavado se pueden hacer con ácido reciclado. Es tesis tema representa un ahorro del 66% en el consumo de agua en esta etapa. Recycling of residual liquids from the conversion of calcium alginate to alginic acid during alginate production process The effect of recycling the residual acid solution from the conversion of calcium alginate to alginic acid from the alga Macrocystis pyrifera was studied. The residual liquid was recycled using a counter current system; it was possible to treat three batches of calcium alginate with the same amount of water, with an effective conversion into alginic acid, saving 56% of fresh water. An inline recycling system was experimented (without water replacement). This system is not recommended, because the large increase of calcium in the alginate after the second recycling, produces a very high apparent viscosity. Using this system the viscosity was reduced in more than 50%. We experimented the effect of the number of acid washings of the alginic acid, on the yield and quality of the final alginate. The acid treatment was carried out with three, two and one washing. It was concluded that three acid washings of the calcium alginate fibers are necessary to obtain an effective conversion of calcium alginate to alginic acid, but the first and second washings can be carried out with recycled acid. This system represents a water saving up to 66% in this step.

scholarly journals The Difference of Angiopoietin-2 Levels between Dengue Hemorrhagic Fever Patients with Shock and without Shock

2019 ◽  
Vol 7 (13) ◽  
pp. 2119-2122 ◽  
Author(s):  
Rinang Mariko ◽  
Eryati Darwin ◽  
Yanwirasti Yanwirasti ◽  
Sri Rezeki Hadinegoro
Keyword(s):  
Dengue Hemorrhagic Fever ◽  
Sampling Design ◽  
Dengue Infection ◽  
Health Sector ◽  
Hemorrhagic Fever ◽  
Incidence And Mortality ◽  
The Mean ◽  
The Difference ◽  
Angiopoietin 2 ◽  
Very High

BACKGROUND: Dengue infection is one of the problems in the national health sector in Indonesia because the incidence and mortality in Indonesia due to dengue infection is still very high. In 2005 Indonesia became the highest contributor to dengue infection in Southeast Asia (53%) with 95.270 people and 1.298 deaths. AIM: This study aims to analyse differences in angiopoietin-2 levels in dengue hemorrhagic fever (DHF) with and without shock. METHODS: This study was a consecutive sampling design with the research subject was obtained based on the order of admission to the hospital — the serum Angiopoietin-2 levels using the ELISA method. The statistical test used is the independent t-test. The value of p < 0.05 was said to be statistically significant. RESULT: The result showed that the mean of Angiopoietin-2 levels in DHF patients with shock was higher than in DHF (p < 0.05). CONCLUSION: This study concluded that there was a difference in the average level of Angiopoietin-2 among DHF patients with shock compared to without shock.

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