Nonsymmetrical separations in thermal diffusion columns

The influence of the feed composition upon the actual degrees of separation attained at the top and bottom sections of a thermogravitational column is discussed using the classical phenomenological theory of Furry, Jones, and Onsager. It is shown that, except for a feed composition of C 0 = 0.5 (mass fraction), the separation profile is nonsymmetric, i.e., the separations in the top and bottom sections of the column are nonsymmetric with respect to the feed composition, the asymmetry increasing as the feed composition moves away from C 0 = 0.5. An equation for the determination of the optimum feed location as a function of the feed composition is derived.

Some observations on asymmetrical separation in thermal diffusion columns

Data have been obtained in steady-state batch operated thermogravitational separation columns using different binary mixtures to test the theory recently published by Morgado et al. The experimental results confirm that separations by thermal diffusion are asymmetrical except when the initial concentration is 0.5 and that the asymmetry is larger as the initial concentration deviates from 0.5 and as the separation potential increases.

A influência de grãos pretos em ligas com cafés de bebida mole

Os autores estudam a influência de grãos pretos em ligas com cafés brasileiros de bebida Mole. Foram ensaiadas porcentagens crescentes de grãos pretos: 0, 1, 2, 5, 10, 15, 20, 30, 40 e 50%. Realizaram-se dois ensaios de degustação em blocos incompletos equilibrados, com t = 10 tratamentos, k = 4 parcelas por bloco, r = 6 repetições, b = 15 blocos, X = 2. Cada parcela era formada por 3 xícaras de tipo padrão e foi provada por 3 degustadores, que davam sua opinião xícara por xícara. Os dados coletados são, pois, 1080, isto é, 540 para cada um dos dois ensaios. Mas cada ensaio tinha realmente apenas 60 parcelas, a cada uma das quais correspondia a média das 9 opiniões sôbre ela emitidas (3 degustadores x 3 xícaras). As bases deste método experimental são as expostas em FAIRBANKS BARBOSA e outros (1962), com as modificações indicadas. Os dois ensaios deram resultados bem concordantes, que levaram às seguintes conclusões: 1 - Os grãos pretos prejudicam sensìvelmente a bebida, e seu efeito é aproximadamente linear. 2 - Porcentagens de grãos pretos de 10% para cima causam prejuizo sensível. 3 - A equação de regressão é Y = 3,792 - 0,0379 X, onde X é a porcentagem de grãos pretos e Y é o número de pontos correspondentes à bebida.

Sobre a nefrosclerose maligna

1º - Das aus den oeffentlichen Krankenhäusern von Rio de Janeiro stammende Sektionsmaterial umfasst einen beträchtlichen Prozentzatz von Individuen schwarzer und gemischter Rasse. Es besteht durchweg aus Angehörigen der sozial und oekonomisch niedersten Bevölkerungsschichten der Stadt und ihrer Vororte, die gemessen am Standard der Gesamtbevölkerung unter den dürftigsten hygienischen Bedingungen leben. So fanden sich unter 212 Autopsien aus dem Anfall der Pathologisch-Anatomischen Abteilung des Institutes Oswaldo Cruz im Jahr 1920 bei 111 Fällen schwarze oder Mischlinsfarbe protokolliert, (52,3%). Unter 349 Sektionen der gleichen Abteilung im Jahr 1938 waren 184 (= 52,7%) von Individuen von schwarzer oder gemischter Rasse. Ein derartiges Material bietet guenstige Bedingungen fuer die Untersuchung der Bedeutung der Rassenzugehoerigkeit als aetiologischem und pathogenem Faktor fuer bestimmte Affektionen, bei welchen sie in der Literatu in diesem Sinn angeführt worden ist. 2º - Unter 1080 Sektionen von Indiduen männlichen Geschlechts jeder Altersstufe aus dem Material der gleichen Abteilung der Jahre 1918-1926 fanden sich bei 214 Faellen syphilitische Befunde protokolliert. (19,8% der Faelle.) 129 (12%) wiesen eine Aortitis oder Arteritis syphilitica auf. 3º - Das histologische Material einer Serie von 528 Autopsien von Individuen im Alter unter 40 Jahren wurde auf das Vorkommen der fuer Nephrosclerose maligna (FAHR) typisch erachteten pathologischen Veraenderungen untersucht. Es wurden 4 Faelle festgestellt, die das Bild dieser Nephropathie zeigten. Unter den 528 Individuen dieser Gruppe waren 244 Weisse, (46,2%) 274 Schwarze oder Mischlinge (51,8%) Bei 10 war die Rassenzugehoerigkeit nicht ersichtlich. 4º - Unter Heranziehung von 6 weiteren Faellen aus anderen Serien von Sektionen der letzten 4 Jahre beläuft sich die Gesamtzahl der mikroskopisch festegestellen Faelle von Nephrosclerose maligna unter dem Material der Pathologisch-Anatomischen Abteilung des Institutes auf 10. Bei einem dieser Faelle (weiblichen Geschlechts) fand sich diese Nephropathie zusammen mit einer congenitalen Missbildung (Aplaise der linken Niere, des Ovarium und der Tube dieser Seite und Hypoplasie des Uterus). 7 dieser Faelle waren maennlichen Geschlechts. 3 waren von weisser, 2 von schwarzer Rasse, 5 waren mischrassig. 5º - Unsere Beobachtungen bieten keinen Anhalt fuer die Annahme, dass der Syphilis oder der Rassenzugehoerigkeit eine besondere Bebeutung fuer die Pathogenese der Nephrose maligna zukommt.

Handheld-assisted field data collection for occupational risk assessment.

A computerized handheld procedure is presented in this paper. It is intended as a database complementary tool, to enhance prospective risk analysis in the field of occupational health. The Pendragon forms software (version 3.2) has been used to implement acquisition procedures on Personal Digital Assistants (PDAs) and to transfer data to a computer in an MS-Access format. The data acquisition strategy proposed relies on the risk assessment method practiced at the Institute of Occupational Health Sciences (IST). It involves the use of a systematic hazard list and semi-quantitative risk assessment scales. A set of 7 modular forms has been developed to cover the basic need of field audits. Despite the minor drawbacks observed, the results obtained so far show that handhelds are adequate to support field risk assessment and follow-up activities. Further improvements must still be made in order to increase the tool effectiveness and field adequacy.

Treatment motivation in adolescents with psychosis or at high risk: Determinants and impact on improvements in symptoms and cognitive functioning, preliminary results.

Abstract Low motivation is frequent in chronic disorders such as psychosis and may limit treatment efficacy. Although some evidence supports this view in adults, few studies so far have focused on adolescents. We assessed the impact of baseline symptoms, cognitive deficits and cognitive treatment characteristics on treatment motivation (TM), and examined whether TM affected treatment outcome. Twenty-eight adolescents with psychotic disorders participated in 16 sessions of computerized cognitive remediation or games. TM was assessed for each session. Lower TM was predicted by more severe symptoms at baseline, and was associated with smaller improvements in symptoms and both cognitive and psychosocial functioning at the end of the intervention. Experiencing success in the treatment exercises enhanced TM in all patients.

Reproducibility of free-breathing cardiovascular magnetic resonance coronary angiography.

OBJECTIVE: Contemporary free-breathing non contrast enhanced cardiovascular magnetic resonance angiography (CMRA) was qualitatively and quantitatively evaluated to ascertain the reproducibility of the method for coronary artery luminal dimension measurements. SUBJECTS AND METHODS: Twenty-two healthy volunteers (mean age 32 +/- 7 years, 12 males) without coronary artery disease were imaged at 2 centers (1 each in Europe and North America) using navigator-gated and corrected SSFP CMRA on a commercial whole body 1.5T System. Repeat images of right (RCA, n = 21), left anterior descending (LAD, n = 14) and left circumflex (LCX, n = 14) coronary arteries were obtained in separate sessions using identical scan protocol and imaging parameters. True visible vessel length, signal-to-noise (SNR), contrast-to-noise ratios (CNR) and the average luminal diameter over the first 4 cm of the vessel were measured. Intra-observer, inter-observer and inter-scan reproducibility of coronary artery luminal diameter were determined using Pearson's correlation, Bland-Altman analysis and intraclass correlation coefficients (ICC). RESULTS: CNR, SNR and the mean length of the RCA, LAD and LCX imaged for original and repeat scans were not significantly different (all p > 0.30). There was a high degree of intra-observer, inter-observer and inter-scan agreements for RCA, LAD and LCX luminal diameter respectively on Bland-Altman and ICC analysis (ICC's for RCA: 0.98. 0.98 and 0.86; LAD: 0.89, 0.89 and 0.63; LCX: 0.95, 0.94 and 0.79). CONCLUSION: In a 2-center study, we demonstrate that free-breathing 3D SSFP CMRA can visualize long continuous segments of coronary vessels with highly reproducible measurements of luminal diameter.

Automatic measurement of key ski jumping phases and temporal events with a wearable system.

We propose a new method, based on inertial sensors, to automatically measure at high frequency the durations of the main phases of ski jumping (i.e. take-off release, take-off, and early flight). The kinematics of the ski jumping movement were recorded by four inertial sensors, attached to the thigh and shank of junior athletes, for 40 jumps performed during indoor conditions and 36 jumps in field conditions. An algorithm was designed to detect temporal events from the recorded signals and to estimate the duration of each phase. These durations were evaluated against a reference camera-based motion capture system and by trainers conducting video observations. The precision for the take-off release and take-off durations (indoor < 39 ms, outdoor = 27 ms) can be considered technically valid for performance assessment. The errors for early flight duration (indoor = 22 ms, outdoor = 119 ms) were comparable to the trainers' variability and should be interpreted with caution. No significant changes in the error were noted between indoor and outdoor conditions, and individual jumping technique did not influence the error of take-off release and take-off. Therefore, the proposed system can provide valuable information for performance evaluation of ski jumpers during training sessions.

Translation of biomechanical concepts in bone tissue engineering: from animal study to revision knee arthroplasty.

Bone defects in revision knee arthroplasty are often located in load-bearing regions. The goal of this study was to determine whether a physiologic load could be used as an in situ osteogenic signal to the scaffolds filling the bone defects. In order to answer this question, we proposed a novel translation procedure having four steps: (1) determining the mechanical stimulus using finite element method, (2) designing an animal study to measure bone formation spatially and temporally using micro-CT imaging in the scaffold subjected to the estimated mechanical stimulus, (3) identifying bone formation parameters for the loaded and non-loaded cases appearing in a recently developed mathematical model for bone formation in the scaffold and (4) estimating the stiffness and the bone formation in the bone-scaffold construct. With this procedure, we estimated that after 3 years mechanical stimulation increases the bone volume fraction and the stiffness of scaffold by 1.5- and 2.7-fold, respectively, compared to a non-loaded situation.

Consuming sports: distinction, univorism and omnivorism

The question of the social usages of culture and its links with social groups continues to be a topic of discussion today. The aim of this article is to contribute to the debate by examining coherence in the choice of physical activities and sports. The study focuses on the upper social groups, questioning, from a macro-sociological standpoint, their possible omnivority and their dissonance of choice with regard to these activities. Based on a quantitative survey of the sports participated in by the French, the study shows that omnivority and massification of activities are major phenomena. However, the upper social groups in France remain distinguishable both in terms of their "high level of omnivority" and their choice of distinctive activities. Dissonance is another of their characteristics but to a lesser extent.