scholarly journals Contemporary Methods for Production of Ultramarine

2022 ◽  
Author(s):  
A.V. Vyboishchik
Keyword(s):  
Two Stage ◽  
Advantages And Disadvantages ◽  
One Stage ◽  
Ultramarine Blue ◽  
The One

Abstract. The article describes the features of ultramarine, its modifications, viz. ultramarine blue. The requirements for ultramarine blue grades are observed, the one-stage and two-stage technologies for the production of ultramarine blue are described, the advantages and disadvantages of both methods are listed, new recommendations for the production of ultramarine blue are offered.

Analysis of one-stage and two-stage crushing of shale in jaw crusher ShchD 10M for manufacture of terrazzo tiles

2020 ◽  
pp. 78-84
Author(s):  
V. S. Bochkov ◽  
S. D. Dyagilev
Keyword(s):  
Size Distribution ◽  
Theory And Practice ◽  
Low Rank ◽  
Open Pit ◽  
Two Stage ◽  
Advantages And Disadvantages ◽  
Jaw Crusher ◽  
One Stage ◽  
Dark Color ◽  
The One

The article presents the experimental research data on oneand two-stage crushing of shale from the Rezh open pit mine in the Ural Region in jaw crusher ShchD 10M with a complex-moving jaw. Shale is a metamorphic rock of low rank, composed mainly of dark-color minerals and quartz or dark-color minerals and feldspar (except for amphiboles). Crushed shale is widely used in construction for coating of building sides, in production of roofing and in manufacture of tiles. For this reason, it is important for the theory and practice to determine rational parameters of shale crushing. The implemented studies into shale crushing show that as against the one-stage process, the two-stage crushing yields much more fines and reduces the yield of coarse (uncrushed) particles. The one-stage crushing offers acceptable coarseness of particles, as well as simplifies the process and allows less number of crushers to be involved. The productivity and time of crushing, as well as weight of shale samples are determined. Using testing screen A 20, size distribution of crushed shale was carried out, and the bar charts of the size distribution were constructed. Advantages and disadvantages of one-and two-stage crushing in a jaw crusher are described.

Two-Stage Procedure for the Quantitative Determination of Autoprothrombin III Concentration and Some Applications

1967 ◽  
Vol 18 (01/02) ◽  
pp. 198-210 ◽  
Author(s):  
Ronald S Reno ◽  
Walter H Seegers
Keyword(s):  
Prothrombin Time ◽  
Factor Vii ◽  
Two Stage ◽  
Pronounced Increase ◽  
One Stage ◽  
Assay Procedure ◽  
Bovine Plasma ◽  
The One ◽  
Autoprothrombin C

SummaryA two-stage assay procedure was developed for the determination of the autoprothrombin C titre which can be developed from prothrombin or autoprothrombin III containing solutions. The proenzyme is activated by Russell’s viper venom and the autoprothrombin C activity that appears is measured by its ability to shorten the partial thromboplastin time of bovine plasma.Using the assay, the autoprothrombin C titre was determined in the plasma of several species, as well as the percentage of it remaining in the serum from blood clotted in glass test tubes. Much autoprothrombin III remains in human serum. With sufficient thromboplastin it was completely utilized. Plasma from selected patients with coagulation disorders was assayed and only Stuart plasma was abnormal. In so-called factor VII, IX, and P.T.A. deficiency the autoprothrombin C titre and thrombin titre that could be developed was normal. In one case (prethrombin irregularity) practically no thrombin titre developed but the amount of autoprothrombin C which generated was in the normal range.Dogs were treated with Dicumarol and the autoprothrombin C titre that could be developed from their plasmas decreased until only traces could be detected. This coincided with a lowering of the thrombin titre that could be developed and a prolongation of the one-stage prothrombin time. While the Dicumarol was acting, the dogs were given an infusion of purified bovine prothrombin and the levels of autoprothrombin C, thrombin and one-stage prothrombin time were followed for several hours. The tests became normal immediately after the infusion and then went back to preinfusion levels over a period of 24 hrs.In other dogs the effect of Dicumarol was reversed by giving vitamin K1 intravenously. The effect of the vitamin was noticed as early as 20 min after administration.In response to vitamin K the most pronounced increase was with that portion of the prothrombin molecule which yields thrombin. The proportion of that protein with respect to the precursor of autoprothrombin C increased during the first hour and then started to go down and after 3 hrs was equal to the proportion normally found in plasma.

Standardization of Factor VIII – IV. Establishment of the 3rd International Standard for Factor VIII: C Concentrate

1983 ◽  
Vol 50 (03) ◽  
pp. 697-702 ◽  
Author(s):  
T W Barrowcliffe ◽  
A D Curtis ◽  
D P Thomas
Keyword(s):  
Factor Viii ◽  
High Purity ◽  
Collaborative Study ◽  
World Health ◽  
Current Standard ◽  
Two Stage ◽  
International Standard ◽  
One Stage ◽  
The One ◽  
Health Organization

SummaryAn international collaborative study was carried out to establish a replacement for the current (2nd) international standard for Factor VIII: C, concentrate. Twenty-six laboratories took part, of which 17 performed one-stage assays, three performed two-stage assays and six used both methods. The proposed new standard, an intermediate purity concentrate, was assayed against the current standard, against a high-purity concentrate and against an International Reference Plasma, coded 80/511, previously calibrated against fresh normal plasma.Assays of the proposed new standard against the current standard gave a mean potency of 3.89 iu/ampoule, with good agreement between laboratories and between one-stage and two- stage assays. There was also no difference between assay methods in the comparison of high-purity and intermediate purity concentrates. In the comparison of the proposed standard with the plasma reference preparation, the overall mean potency was 4.03 iu/ampoule, but there were substantial differences between laboratories, and the two-stage method gave significantly higher results than the one stage method. Of the technical variables in the one-stage method, only the activation time with one reagent appeared to have any influence on the results of this comparison of concentrate against plasma.Accelerated degradation studies showed that the proposed standard is very stable. With the agreement of the participants, the material, in ampoules coded 80/556, has been established by the World Health Organization as the 3rd International Standard for Factor VIII :C, Concentrate, with an assigned potency of 3.9 iu/ampoule.

scholarly journals Study on the Leakage and Inter-Stage Pressure Drop Characteristics of Two-Stage Finger Seal

2021 ◽  
Vol 11 (5) ◽  
pp. 2239
Author(s):  
Hailin Zhao ◽  
Hua Su ◽  
Guoding Chen ◽  
Yanchao Zhang
Keyword(s):  
Pressure Drop ◽  
Pressure Difference ◽  
Radial Displacement ◽  
Mean Square ◽  
The Finite Element Method ◽  
Axial Pressure ◽  
Two Stage ◽  
One Stage ◽  
The One ◽  
Lower Contact

To solve the high leakage and high wear problems faced by sealing devices in aeroengines under the condition of high axial pressure difference, the two-stage finger seal is proposed in this paper. The finite element method and computational fluid dynamics (FEM/CFD) coupling iterative algorithm of the two-stage finger seal is developed and validated. Then the performance advantages of two-stage finger seal compared to the one-stage finger seal are studied, as well as the leakage and the inter-stage pressure drop characteristics of two-stage finger seal are investigated. Finally, the measure to improve the inter-stage imbalance of pressure drop of two-stage finger seal is proposed. The results show that the two-stage finger seal has lower leakage and lower contact pressure than the one-stage finger seal at high axial pressure difference, but there exists an inter-stage imbalance of pressure drop. Increasing the axial pressure difference and the root mean square (RMS) roughness of finger element can aggravate the imbalance of pressure drop, while the radial displacement excitation of rotor has little influence on it. The results also indicate that the inter-stage imbalance of pressure drop of the two-stage finger seal can be improved by increasing the number of finger elements of the 1st finger seal and decreasing the number of finger elements of the 2nd finger seal.

scholarly journals Identification of Sources of Inter-Laboratory Variation in Factor VIII Assay

1977 ◽  
Author(s):  
T.B.L. Kirkwood ◽  
C.R. Rizza ◽  
T.J. Snape ◽  
I. Rhymes ◽  
D.E.G. Austen
Keyword(s):  
Factor Viii ◽  
Systematic Difference ◽  
Normal System ◽  
Two Stage ◽  
Initial Dilution ◽  
One Stage ◽  
Collaborative Studies ◽  
Freeze Dried ◽  
Sources Of Variation ◽  
The One

A repeated finding of national and international collaborative studies of standard Factor VIII preparations has been that systematic differences exist between laboratories in their measurement of the relative activities of the same pairs of Factor VIII preparations.A workshop meeting was held at the Oxford Haemophilia Centre (England) during 23rd-26th November 1976 to investigate which of the possible sources of variation between laboratories were responsible. Participants from 16 British laboratories (9 one-stage, 7 two-stage) performed a total of 273 assays using three freeze-dried preparations of differing purity (a plasma, an intermediate and a high purity concentrate). The results of assays with each participant using their normal system established that, if the participants were a representative cross-section, approximately one-third of one-stage laboratories would show a systematic difference from the overall mean of at least 16%, with a similar figure for the two-stage laboratories of 9%. Various features of the assay systems were then modified in a controlled series of experiments. The results showed conclusively that i) differences between reagents accounted for most of the variation between laboratories and, ii) the two-stage assays were, on average, detecting relatively more activity in the more purified preparations than the one-stage assays. The results also suggested that the use of buffer as opposed to haemophilic plasma for the initial dilution of concentrates did not affect the assay results.

The Relation between Staphylocoagulase Reacting Factor and Proteins Induced by Vitamin K Absence

1975 ◽  
Author(s):  
B. M. Bas ◽  
A. D. Muller ◽  
H. G. Hemker
Keyword(s):  
Vitamin K ◽  
Vitamin K Antagonists ◽  
The Other ◽  
Two Stage ◽  
One Stage ◽  
Echis Carinatus ◽  
The Difference ◽  
The One ◽  
Factor Assay

Five different ways of estimating prothrombin are applied to the plasma of persons receiving vitamin K antagonists, to know: the one-stage assay, the two-stage assay, the Echis Carinatus Venom assay, the coagulase-reacting factor assay and the immunological assay. The Protein Induced by Vitamin K Absence analogous to prothrombin (PIVKA-II) can be shown to be co-estimated in all but the one-stage assay. There are minor differences, however, between the other four tests. The most practical way to assess both prothrombin and PIVKA-II seems to be the coagulase-reacting factor assay. The difference between the one-stage assay and the others can be explained on basis of the new data on the role of vitamin K in prothrombin biosynthesis. The differences between the other tests are smaller and remain to be explained.

scholarly journals Plasma Transfusions in Hemophilia

Blood ◽  
1952 ◽  
Vol 7 (7) ◽  
pp. 710-720 ◽  
Author(s):  
S. VAN CREVELD ◽  
M. M. P. PAULSSEN
Keyword(s):  
Two Stage ◽  
Coagulation Time ◽  
Prothrombin Activity ◽  
Lasting Effect ◽  
One Stage ◽  
The One ◽  
Rapid Appearance

Abstract Transfusions of heparinized plasma have a greater and more lasting effect on the coagulation time of hemophiliacs than transfusions of citrated plasma. Both in vitro and in vivo, heparinized plasma causes in hemophiliacs a far greater consumption of prothrombin as determined with the two-stage method than citrated plasma. In using the one-stage method no important differences in prothrombin activity are found after transfusions of heparinized and of citrated plasma respectively. This fact was thought to be connected with the more or less rapid appearance of an accelerator. Its a hemophiliac with a circulating anticoagulant, transfusions of heparinized plasma were unable to shorten the coagulation time to any important degree, nor did these transfusions cause an important decrease of serum prothrombin as determined by the two-stage method.

EFFECT OF COLD ACTIVATION, AL(OH)3 ADSORBTIGN, TISSUE FACTOR AND PLATELET ON ONE/TWO STAGE CEROMOGENIC ASSAYS OF F. VIII

1987 ◽  
Author(s):  
M J Seghatchian ◽  
M J Dembinski
Keyword(s):  
Tissue Factor ◽  
Large Scale ◽  
Kinetic Property ◽  
Thrombin Inhibitor ◽  
Lag Phase ◽  
Phase Reaction ◽  
Response Curves ◽  
Two Stage ◽  
One Stage ◽  
The One

Two stage Coatest assay of F. VIII is reportedly insensitive to pretreatment of F. VIII with thrombin. Since thrombin is formed rapidly, during the incubation step, a one stage method was tried by incorporating S2222, containing thrombin inhibitor (1-2581) in the incubation system, thus making the assay highly specific to F. Xa-induced activation of F. VIII and allowing to monitor directly the formation of paranitroaniline in microtray plate at 2-5 min. intervals. Initial comparative analyses performed on cold activated and/or adsorbed/non-adsorbed samples (FFP, cryoprecipitate and hypo- or hypercoagulable state) revealed that in all cases the lag phase was prolonged (2-3 fold) in the one stage method. Cold activation had little effect on the lag phase/reaction rate, whereas AL(0E)3 decreased up to 50% F. VIII like activity, prolonged the lag phase and dose-response curves become non-parallel. Substituting phospholipid (pL) by tissue factor (TF) or addition of diluted TF (1/500) to reaction mixture increased synergistically the rate of F. Xa generation in both adsorbed and non-adsorbed system. In contrast washed platelets (PLT), up to 3000 x 109/1, were less effective on both TF or PL-induced F. Xa generation. The presence of 1-2581 in this system prolonged the lag phase to Ih. Substitution of the conventional O. D. reading by the time required to achieve a fixed absorbancy (O. D. =0.5) make the one stage coatest F. VIII equivalent to the APPT-type assay. Based on these results it is concluded that thrombin is involved in increasing F. VIII catalytic activity. TF and F. VII contribute to the shortening of the lag phase and increased F.a generation. The Kinetic property of cell surface-bound F. VIII is not the same in the presence or absence of thrombin. The reported insensitivity coatest F. VIII to thrombin is probably due to the fact that thrombin activated F. VIII is a good substrate for F. Xa and is cleaved by F. Xa which is produced in abundance in the two-stage chromogenic assays. A new procedure for monitoring various pathways of F. Xa generation, based on the coatest reagent is provided, which is particularly suitable for large scale screening of blood donors and blood products.

scholarly journals Changing Preference of One- Vs. Two-Stage Implant Placement in Partially Edentulous Individuals: An 18-Year Retrospective Study

2020 ◽  
Vol 10 (20) ◽  
pp. 7060
Author(s):  
Liat Chaushu ◽  
Sarit Naishlos ◽  
Ofir Rosner ◽  
Eran Zenziper ◽  
Ari Glikman ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Bone Loss ◽  
Gingival Index ◽  
Implant Survival ◽  
Two Stage ◽  
One Stage ◽  
Implant Placement ◽  
Crestal Bone Loss ◽  
The One

The purpose of the present long-term retrospective study was to assess the changing preference of one- vs. two-stage implant placement in partially edentulous individuals. The clinical outcome measures were one- vs. two-stage implant placement, implant survival, and gingival index. The radiological outcome measure was crestal bone loss. Other recorded information included gender, age, implant characteristics (brand, type, length, diameter) and implant location (maxilla/mandible). A total of 393 implants in 111 patients were included. The results revealed that there were no significant demographic differences between the one- and two-stage implant placement groups. There was a preference for one-stage surgery when wide diameter implants were used and when the number of implants per patient was ≤3. The mandible was the major implant site in the one-stage surgery group. Crestal bone loss and gingival index were similar for the two groups in both the short and long term. It can be concluded that lack of any long-term differences in implant survival, crestal bone loss and gingival health around implants after one- or two-stage implant placement promoted a significant change over 18 years, increasing to 50% the prevalence of one-stage surgery.

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