Operation of a six-effect evaporator station with a deficit in the vapour balance

2021 ◽  
pp. 513-522
Author(s):  
Piotr Lenard

During the operation of a six-effect evaporator station the vapour balance is subject of interfering incidents such as changing technological states of the process or surrounding conditions (ambient temperature e.g.) This article analyses and compares possible methods of managing the operation i.e. reaction to these incidents. In particular, methods of stabilizing the vapour balance by supplying water or thin juice to individual effects of the evaporator station and bypassing the vapours between effects are compared. The best way of reacting to the overload of the evaporator station seems to be the bypass of vapour from an effect of higher parameters to an effect of lower parameters. This method creates a much faster reaction of the evaporator station to excessive bleeding of vapour than supply of water or thin juice, which need to mix with the juice in the vessels. Feeding water to the thin juice tank or to one of the effects of the evaporator station to compensate excessive vapour consumption can be an acceptable solution in case of prolonged increase in vapour consumption from the evaporator station due to e.g. a significant decrease in ambient temperature.

Author(s):  
S.W. French ◽  
N.C. Benson ◽  
C. Davis-Scibienski

Previous SEM studies of liver cytoskeletal elements have encountered technical difficulties such as variable metal coating and heat damage which occurs during metal deposition. The majority of studies involving evaluation of the cell cytoskeleton have been limited to cells which could be isolated, maintained in culture as a monolayer and thus easily extracted. Detergent extraction of excised tissue by immersion has often been unsatisfactory beyond the depth of several cells. These disadvantages have been avoided in the present study. Whole C3H mouse livers were perfused in situ with 0.5% Triton X-100 in a modified Jahn's buffer including protease inhibitors. Perfusion was continued for 1 to 2 hours at ambient temperature. The liver was then perfused with a 2% buffered gluteraldehyde solution. Liver samples including spontaneous tumors were then maintained in buffered gluteraldehyde for 2 hours. Samples were processed for SEM and TEM using the modified thicarbohydrazide procedure of Malich and Wilson, cryofractured, and critical point dried (CPD). Some samples were mechanically fractured after CPD.


Author(s):  
S. Mahajan

The evolution of dislocation channels in irradiated metals during deformation can be envisaged to occur in three stages: (i) formation of embryonic cluster free regions, (ii) growth of these regions into microscopically observable channels and (iii) termination of their growth due to the accumulation of dislocation damage. The first two stages are particularly intriguing, and we have attempted to follow the early stages of channel formation in polycrystalline molybdenum, irradiated to 5×1019 n. cm−2 (E > 1 Mev) at the reactor ambient temperature (∼ 60°C), using transmission electron microscopy. The irradiated samples were strained, at room temperature, up to the macroscopic yield point.Figure 1 illustrates the early stages of channel formation. The observations suggest that the cluster free regions, such as A, B and C, form in isolated packets, which could subsequently link-up to evolve a channel.


Author(s):  
Robert C. Rau

Previous work has shown that post-irradiation annealing, at temperatures near 1100°C, produces resolvable dislocation loops in tungsten irradiated to fast (E > 1 MeV) neutron fluences of about 4 x 1019 n/cm2 or greater. To crystallographically characterize these loops, tilting experiments were carried out in the electron microscope on a polycrystalline specimen which had been irradiated to 1.5 × 1021 n/cm2 at reactor ambient temperature (∼ 70°C), and subseouently annealed for 315 hours at 1100°C. This treatment produced large loops averaging 1000 Å in diameter, as shown in the micrographs of Fig. 1. The orientation of this grain was near (001), and tilting was carried out about axes near [100], [10] and [110].


Author(s):  
J. J. Laidler

The presence of three-dimensional voids in quenched metals has long been suspected, and voids have indeed been observed directly in a number of metals. These include aluminum, platinum, and copper, silver and gold. Attempts at the production of observable quenched-in defects in nickel have been generally unsuccessful, so the present work was initiated in order to establish the conditions under which such defects may be formed.Electron beam zone-melted polycrystalline nickel foils, 99.997% pure, were quenched from 1420°C in an evacuated chamber into a bath containing a silicone diffusion pump fluid . The pressure in the chamber at the quenching temperature was less than 10-5 Torr . With an oil quench such as this, the cooling rate is approximately 5,000°C/second above 400°C; below 400°C, the cooling curve has a long tail. Therefore, the quenched specimens are aged in place for several seconds at a temperature which continuously approaches the ambient temperature of the system.


1991 ◽  
Vol 65 (04) ◽  
pp. 355-359 ◽  
Author(s):  
E Gray ◽  
J Watton ◽  
S Cesmeli ◽  
T W Barrowcliffe ◽  
D P Thomas

SummaryThe in vitro anticoagulant activities of recombinant desulphatohirudin (r-hirudin) were studied in the activated partial thromboplastin time (APTT) and the thrombin generation test : systems. In the APTT at concentrations below 5 μg/ml, r-hirudin showed a dose-response curye. At concentrations above 5 μg/ml, the plasma became unclottable, but in the thrombin generation test , at least 10 μg/ml of r-hirudin was required for full inhibition of thrombin generation. The antithrombotic effect was assessed using a rabbit venous stasis model; 150 μg/ml r-hirudin completely prevented thrombus formation at 10 and 20 min stasis. At antithrombotic dose, the mean bleeding time ratio measured in a rabbit ear template model, was not prolonged over control values. At higher doses, the bleeding time ratios were higher than those observed for the same dosage of heparin. These data indicate that while r-hirudin is an effective antithrombotic agent, antithrombotic doses have to be carefully titrated to avoid excessive bleeding.


1978 ◽  
Vol 40 (02) ◽  
pp. 532-541 ◽  
Author(s):  
Anders Lagrelius ◽  
Nils-Olov Lunell ◽  
Margareta Blombäck

SummaryThe aim of the present study was to investigate the effect on blood coagulation and fibrinolysis of a natural oestrogen preparation, piperazine oestrone sulphate, prospectively in menopausal women. Scopolamine was given to the control group.The women were investigated before and during treatment with regard to factors VIII, VII, X, V, fibrinopeptide A, antithrombin III, plasminogen, rapid antiplasmin and α1-antitrypsin. There was no significant change towards hypercoagulability or decreased fibrinolysis in any group. In the oestrogen group, however, a tendency towards an increased level of plasminogen and a decreased level of antiplasmin was demonstrated. In the scopolamine group there was an unexpected fall in factors X and V and also in plasminogen and α1,-antitrypsin. A low level of some blood coagulation factors in some of the women before treatment is somewhat astonishing; none of them had any history of excessive bleeding.


2018 ◽  
Vol 24 (2) ◽  
Author(s):  
PIYUSH MISHRA ◽  
DEVENDRA KUMAR BHATT

Pasta was prepared by incorporation of Ocimum sanctum (Basil) for better textural and sensory properties. The pasta was incorporated with the leaf extract of Ocimum sanctum at different concentrations of control, 5, 10, and 15.The natural antioxidants present in the O. sanctum leaf powder that was incorporated in the fruit leather showed extended shelf-life over three months when compared with control, without any added preservative at ambient temperature. Also the nutritional stability of the product was studied under two flexible packages of polypropylene and polyester out of that the products packed in polypropylene showed better storage stability .


2018 ◽  
Vol 239 (3) ◽  
pp. 313-324 ◽  
Author(s):  
Lewin Small ◽  
Henry Gong ◽  
Christian Yassmin ◽  
Gregory J Cooney ◽  
Amanda E Brandon

One major factor affecting physiology often overlooked when comparing data from animal models and humans is the effect of ambient temperature. The majority of rodent housing is maintained at ~22°C, the thermoneutral temperature for lightly clothed humans. However, mice have a much higher thermoneutral temperature of ~30°C, consequently data collected at 22°C in mice could be influenced by animals being exposed to a chronic cold stress. The aim of this study was to investigate the effect of housing temperature on glucose homeostasis and energy metabolism of mice fed normal chow or a high-fat, obesogenic diet (HFD). Male C57BL/6J(Arc) mice were housed at standard temperature (22°C) or at thermoneutrality (29°C) and fed either chow or a 60% HFD for 13 weeks. The HFD increased fat mass and produced glucose intolerance as expected but this was not exacerbated in mice housed at thermoneutrality. Changing the ambient temperature, however, did alter energy expenditure, food intake, lipid content and glucose metabolism in skeletal muscle, liver and brown adipose tissue. Collectively, these findings demonstrate that mice regulate energy balance at different housing temperatures to maintain whole-body glucose tolerance and adiposity irrespective of the diet. Despite this, metabolic differences in individual tissues were apparent. In conclusion, dietary intervention in mice has a greater impact on adiposity and glucose metabolism than housing temperature although temperature is still a significant factor in regulating metabolic parameters in individual tissues.


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