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[en] The purpose of the paper is to describe the performance limits which can be expected with basic pulse systems using tunnel diodes. The first part of the paper studies the response of a tunnel diode to a current step, and to a square-wave current. The second part, as an illustration, describes some actual systems and their performance. (author)
[fr]
Le but du present memoire est de preciser les limites des performances que l'on peut attendre des montages impulsionnels de base utilisant des diodes tunnel. Une premiere partie etudie la reponse d'une diode tunnel a un echelon de courant, puis a un creneau de courant. Une deuxieme partie, en illustration, decrit quelques realisations pratiques et leurs performances. (author)[es]
La finalidad de la presente memoria es definir los limites de utilizacion de los circuitos de impulsos basados en diodos tunel. La primera parte estudia la respuesta de un diodo tunel a un impulso de corriente escalonado y, luego, a un impulso de corriente rectangular. A titulo ilustrativo, la segunda parte describe algunos circuitos y los resultados con ellos obtenidos. (author)[ru]
TSel' nastoyashchej raboty - utochnit' predely primenenij, kotorye ozhidayut poluchit' ot osnovnykh impul'snykh skhem pri ispol'zovanii tunnel'nykh diodov. V pervoj chasti rassmatrivaetsya reaktsiya tunnel'nogo dioda na stupenchatoe, a zatem na pryamougol'noe izmenenie toka. Vo vtoroj chasti v kachestve illyustratsii daetsya opisanie nekotorykh prakticheskikh dostizhenij i ikh primenenie. (author)Source
International Atomic Energy Agency, Vienna (Austria); 544 p; Apr 1962; p. 179-193; Conference on Nuclear Electronics; Belgrade, Yugoslavia (Serbia); 15-20 May 1961; ISSN 0074-1884; 
; 16 figs
; 16 figs
[en] A clinical trial was conducted at the Institut Gustave Roussy between October 1972 and December 1980 to compare mastectomy with local excision plus Cobalt-irradiation, in patients with breast cancer tumors of 20 mm in diameter or less at macroscopic examination. Low-axillary dissection and extemporaneous histologic examination were carried out for all patients. If one or more positive nodes were found, complete axillary dissection was performed. The study included 179 patients. No significant difference was detected in either overall or relapse-free survival between the two groups, although the conservatively treated group showed slightly better results. The results of conservative treatment were esthetically satisfactory in 92% of the cases. The trial included a second randomization for the patients with positive axillary nodes to assess the value of nodal area irradiation; 72 patients were studied in this part of the trial. No significant differences were found between the two groups after adjustment for the number of positive axillary nodes, although the no-nodal irradiation group showed better results and less complications than the nodal irradiation group
Journal
Cancer (Philadelphia); ISSN 0008-543X; ; v. 53(5); p. 1209-1213
; v. 53(5); p. 1209-1213
[en] Seventy-five patients with medullary thyroid carcinoma (MTC) have been treated at Institut Gustave-Roussy from 1932 to 1979. Of these, 13 patients had distant metastases and received palliative treatment, their median survival was 3 years. Sixty-two patients with MTC limited to the neck received curative treatment: 6 had exclusive external radiotherapy for inoperable disease and 56 were surgically treated: 23 by total thyroidectomy and 33 by partial thyroidectomy. After surgery 29 patients received external radiotherapy for cervical lymph node involvement (25/29) and/or incomplete surgical resection (12/27). The survival rate was 69% at 5 years and 48% at 10 years. The 29 patients who received post-operative cervical radiotherapy had initially more extensive local disease (p<0.05) than the 27 patients treated by surgery alone, nevertheless their survival was slightly higher. No difference in survival rate was observed between patients treated by total thyroidectomy or partial thyroidectomy, among whom only 4 local recurrences occurred. Three of the 6 patients treated with external radiotherapy alone experienced long survival (4, 7 and 10 years) and a fourth is still in clinical remission 4 years after treatment. The effectiveness of chemotherapy in patients with metastases was poor, only one patient out of 6 had a partial remission following a treatment by adriamycin. In the familial form and multiple endocrine neoplasia type II, total thyroidectomy appears to be indicated. In the sporadic cases, partial thyroidectomy is usually sufficient. External radiotherapy is effective in MTC and seems to be able to eradicate small foci of residual tumor; it is indicated when surgical excision is impossible or incomplete
Journal
International Journal of Radiation Oncology, Biology and Physics; ISSN 0360-3016; ; v. 9(2); p. 161-169
; v. 9(2); p. 161-169
[en] The equipment described was designed for measuring the power doubling time of the CABRI reactor at Cadarache during the exponential phase of the transient state produced by a stepwise change in reactivity. The doubling time must be known accurately since it yields the value of excess reactivity introduced and serves as a basis for intercomparison of experiments. For safety reasons the control room is located at a distance of 300 m from the reactor. The main characteristics of the apparatus are as follows. Detectors: Ionization chambers sensitive to neutrons or gamma radiation. Principle of measurement : The current from the ionization chamber is fed to the input of an amplifier. A fixed threshold at the amplifier output causes the negative feedback resistor R to be replaced by a resistor R/2. Between each passing of the threshold, the chamber current, and thus the power of the reactor, is doubled. A signal of 1 Mc/s from a time-base generator is fed to the counting input register of a high-speed memory made with thin ferromagnetic strips. With each change in range the contents of the register, i. e. the doubling time itself expressed in microseconds, are incorporated in the memory. Measurement ranges: Doubling times from 2 ms to 5 s. Dynamics: Eight doubling times for chamber currents from 10' to 10-5 A. Accuracy: Several times 10-3. Presentation of results: Three intermediate thresholds permit registration of the T/4 values. After each increase in reactor power the print-out unit presents 32 doubling-time measurements to four significant figures (four overlapping measurements per doubling time). Technology: The amplifier, the thresholds, the logical circuits, and most of the control circuits of the thin-strip memory are made with integrated circuits. Switching is carried out by means of field-effect transistors. Emphasis is placed on the problems posed by the use of advanced techniques such as integrated circuits and memories made with thin ferromagnetic strips, and the advantages derived from using them. (author)
[fr]
Cet appareil a été réalisé pour mesurer le temps de doublement de la puissance du réacteur CABRI de Cadarache pendant la partie exponentielle du régime transitoire provoqué par un échelon de réactivité. Le temps de doublement doit être connu avec précision, car il donne la valeur de l'excès de réactivité introduit et sert de base pour la comparaison des expériences entre elles. Pour des raisons de sécurité, la salle de contrôle est placée à 300 m du réacteur lui-même. Les caractéristiques principales de l'appareil sont les suivantes. Détecteurs utilisés: Chambres d'ionisation sensibles aux neutrons ou aux y . Principe de la mesure: Le courant de la chambre d'ionisation est envoyé sur l'entrée d'un amplificateur opérationnel. Un seuil fixe placé à la sortie de celui-ci provoque le remplacement de la résistance de contreréaction R par une résistance R/2. Entre chaque franchissement du seuil, le courant de chambre, donc la puissance du réacteur, passe du simple au double. Une base de temps 1 MHz est injectée dans le registre d'entrée comptant d'une mémoire rapide à lames minces ferromagnétiques. A chaque changement de gamme, le contenu du registre, c'est-à-dire le temps de doublement lui-même exprimé en microsecondes, est pris en mémoire. Gammes de mesure: Temps de doublement de 2 ms à 5 s. Dynamique: Huit temps de doublement pour des courants de chambre allant de 10-7 à 10-5 A. Précision de mesures: qq. 10-3. Présentation ¿es résultats: Trois seuils intermédiaires permettent d'enregistrer les T/4. Après chaque divergence, un programme permet de présenter sur imprimante 32 mesures du temps de doublement avec quatre chiffres significatifs Quatre mesures imbriquées par temps de doublement). Technologie: L'amplificateur opérationnel, les seuils, les circuits logiques, ainsi que la majorité des circuits de commande de la mémoire à lames minces sont réalisés en circuits intégrés. Les commutations sont réalisées à l'aide de transistors à effet de champ. On insistera sur les problèmes posés par l'utilisation des technologies avancées: circuits intégrés et mémoires à lames minces ferromagnétiques ainsi que sur les avantages qui découlent de leur utilisation. (author)Source
International Atomic Energy Agency, Vienna (Austria); 678 p; Jun 1966; p. 185-200; Conference on Nuclear Electronics; Bombay (India); 22-26 Nov 1965; IAEA-CN--22/24; ISSN 0074-1884; ; 5 refs., 10 figs.
; 5 refs., 10 figs.
[en] Short communication
Journal
[en] The diffusion of zinc was studied in the Callovo-Oxfordian clay-stone, which is a potential host rock for the retrievable disposal of high-level radioactive wastes. Two in-diffusion laboratory experiments were performed with initial zinc concentrations of 4 10-5 mol L-1 and 8 10-6 mol L-1 (resp.) for 35 days. The zinc rock profile was acquired using an original technique, the μLIBS, with a high resolution (10 μm), calibrated with the abrasive peeling method. The experimental data, i.e. Zn concentration monitoring in the source reservoir and Zn rock profile, were successfully reproduced using a chemical-transport code. In that code, the sorption of Zn was described by a multi-site ion-exchange model, with only the effective diffusion coefficient value being adjusted (De = 8 10-11 m2 s-1). This De value, 2 times higher than that of tritiated water, indicates that zinc, like most cations, is also subject to enhanced diffusion in clay rocks. (authors)
Journal
Procedia Earth and Planetary Science; ISSN 1878-5220; ; v. 7; p. 774-777
; v. 7; p. 774-777
[en] The effect of internal mammary chain treatment on each type of malignant death-related event was analyzed in 1195 patients with operable breast cancer and histologically involved axillary lymph nodes. A group of 135 patients who had no internal mammary chain treatment was compared with a control group of 1060 patients who were treated by surgery and/or postoperative radiation therapy. In a multivariate analysis taking into account age, clinical size of the tumor, histoprognostic grading, and the number of positive axillary lymph nodes, quantitative interaction tests were used to determine whether the effects of internal mammary chain treatment on each type of malignant event were significantly different for patients with a lateral tumor compared with those with a medial tumor. The authors found that the effects of this treatment on the risks of distant metastases and of secondary breast cancer were not the same for the patients with a medial tumor as for those with a lateral tumor. For the untreated patients with a medial tumor, the risks of distant metastases and second breast cancer were, respectively, 1.6 (P = 0.02) and 2.9 (P = 0.02), compared with the treated patients. Conversely, for women with lateral tumor, no difference between the two treatment groups was observed. Thus, internal mammary chain treatment may improve long-term survival rate in patients with a medial tumor and positive axillary lymph nodes essentially by decreasing the risk of development of distant metastases (mainly brain, distant lymph nodes, multiple simultaneous metastases) and/or a secondary breast cancer
Journal
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