Effect of polydispersity on bubble characteristics of Geldart Group B particles

2021 ◽  
pp. 129880
Author(s):  
Jia Wei Chew ◽  
Ray A. Cocco
Author(s):  
O. M. Katz

The swelling of irradiated UO2 has been attributed to the migration and agglomeration of fission gas bubbles in a thermal gradient. High temperatures and thermal gradients obtained by electron beam heating simulate reactor behavior and lead to the postulation of swelling mechanisms. Although electron microscopy studies have been reported on UO2, two experimental procedures have limited application of the results: irradiation was achieved either with a stream of inert gas ions without fission or at depletions less than 2 x 1020 fissions/cm3 (∼3/4 at % burnup). This study was not limited either of these conditions and reports on the bubble characteristics observed by transmission and fractographic electron microscopy in high density (96% theoretical) UO2 irradiated between 3.5 and 31.3 x 1020 fissions/cm3 at temperatures below l600°F. Preliminary results from replicas of the as-polished and etched surfaces of these samples were published.


Author(s):  
Taber A. Ba-Omar ◽  
Philip F. Prentis

We have recently carried out a study of spermiogenic differentiation in two geographically isolated populations of Aphanius dispar (freshwater teleost), with a view to ascertaining variation at the ultrastructural level. The sampling areas were the Jebel Al Akhdar in the north (Group A) and the Dhofar region (Group B) in the south. Specimens from each group were collected, the testes removed, fixed in Karnovsky solution, post fixed in OsO, en bloc stained with uranyl acetate and then routinely processed to Agar 100 resin, semi and ultrathin sections were prepared for study.


JAMA ◽  
1966 ◽  
Vol 196 (5) ◽  
pp. 383-387 ◽  
Author(s):  
D. Reed
Keyword(s):  

VASA ◽  
2015 ◽  
Vol 44 (3) ◽  
pp. 0220-0228 ◽  
Author(s):  
Marion Vircoulon ◽  
Carine Boulon ◽  
Ileana Desormais ◽  
Philippe Lacroix ◽  
Victor Aboyans ◽  
...  

Background: We compared one-year amputation and survival rates in patients fulfilling 1991 European consensus critical limb ischaemia (CLI) definition to those clas, sified as CLI by TASC II but not European consensus (EC) definition. Patients and methods: Patients were selected from the COPART cohort of hospitalized patients with peripheral occlusive arterial disease suffering from lower extremity rest pain or ulcer and who completed one-year follow-up. Ankle and toe systolic pressures and transcutaneous oxygen pressure were measured. The patients were classified into two groups: those who could benefit from revascularization and those who could not (medical group). Within these groups, patients were separated into those who had CLI according to the European consensus definition (EC + TASC II: group A if revascularization, group C if medical treatment) and those who had no CLI by the European definition but who had CLI according to the TASC II definition (TASC: group B if revascularization and D if medical treatment). Results: 471 patients were included in the study (236 in the surgical group, 235 in the medical group). There was no difference according to the CLI definition for survival or cardiovascular event-free survival. However, major amputations were more frequent in group A than in group B (25 vs 12 %, p = 0.046) and in group C than in group D (38 vs 20 %, p = 0.004). Conclusions: Major amputation is twice as frequent in patients with CLI according to the historical European consensus definition than in those classified to the TASC II definition but not the EC. Caution is required when comparing results of recent series to historical controls. The TASC II definition of CLI is too wide to compare patients from clinical trials so we suggest separating these patients into two different stages: permanent (TASC II but not EC definition) and critical ischaemia (TASC II and EC definition).


VASA ◽  
2015 ◽  
Vol 44 (6) ◽  
pp. 451-457 ◽  
Author(s):  
Vincenzo Gasbarro ◽  
Luca Traina ◽  
Francesco Mascoli ◽  
Vincenzo Coscia ◽  
Gianluca Buffone ◽  
...  

Abstract. Background: Absorbable sutures are not generally accepted by most vascular surgeons for the fear of breakage of the suture line and the risk of aneurysmal formation, except in cases of paediatric surgery or in case of infections. Aim of this study is to provide evidence of safety and efficacy of the use of absorbable suture materials in carotid surgery. Patients and methods: In an 11 year period, 1126 patients (659 male [58.5 %], 467 female [41.5 %], median age 72) underwent carotid endarterectomy for carotid stenosis by either conventional with primary closure (cCEA) or eversion (eCEA) techniques. Patients were randomised into two groups according to the type of suture material used. In Group A, absorbable suture material (polyglycolic acid) was used and in Group B non-absorbable suture material (polypropylene) was used. Primary end-point was to compare severe restenosis and aneurysmal formation rates between the two groups of patients. For statistical analysis only cases with a minimum period of follow-up of 12 months were considered. Results: A total of 868 surgical procedures were considered for data analysis. Median follow-up was 6 years (range 1-10 years). The rate of postoperative complications was better for group A for both cCEA and eCEA procedures: 3.5 % and 2.0 % for group A, respectively, and 11.8 % and 12.9 % for group B, respectively. Conclusions: In carotid surgery, the use of absorbable suture material seems to be safe and effective and with a general lower complications rate compared to the use of non-absorbable materials.


Phlebologie ◽  
2009 ◽  
Vol 38 (04) ◽  
pp. 157-163 ◽  
Author(s):  
A. Franek ◽  
L. Brzezinska-Wcislo ◽  
E. Blaszczak ◽  
A. Polak ◽  
J. Taradaj

SummaryA prospective randomized clinical trial was undertaken to compare a medical compression stockings with two-layer short-stretch bandaging in the management of venous leg ulcers. Study endpoints were number of completely healed wounds and the clinical parameters predicting the outcome. Patients, methods: Eighty patients with venous leg ulcers were included in this study, and ultimately allocated into two comparative groups. Group A consisted of 40 patients (25 women, 15 men). They were treated with the compression stockings (25–32 mmHg) and drug therapy. Group B consisted of 40 patients (22 women, 18 men). They were treated with the short-stretch bandages (30–40 mmHg) and drug therapy, administered identically as in group A. Results: Within two months the 15/40 (37.50%) patients in group A and 5/40 (12.50%) in group B were healed completely (p = 0.01). For patients with isolated superficial reflux, the healing rates at two months were 45.45% (10/22 healed) in group A and 18.18% (4/22 healed) in group B (p = 0.01). For patients with superficial plus deep reflux, the healing rates were 27.77% (5/18 healed) in group A and 5.55% (1/18 healed) in group B (p = 0.002). Comparison of relative change of the total surface area (61.55% in group A vs. 23.66% in group B), length (41.67% in group A vs. 27.99% in group B), width (46.16% in group A vs. 29.33% in group B), and volume (82.03% in group A vs. 40.01% in group B) demonstrated difference (p = 0.002 in all comparisons) in favour of group A. Conclusion: The medical compression stockings are extremely useful therapy in enhancement of venous leg ulcer healing (both for patients with superficial and for patients who had superficial plus deep reflux). Bandages are less effective (especially for patients with superficial plus deep reflux, where the efficiency compared to the stockings of applied compression appeared dramatically low). These findings require confirmation in other randomized clinical trials with long term results.


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