THE INFLUENCE OF THE PREHEATING OF WOOD IN WATER ON THE RATE OF DELIGNIFICATION BY SULPHITE LIQUOR

1935 ◽  
Vol 13b (3) ◽  
pp. 149-155 ◽  
Author(s):  
A. J. Corey ◽  
O. Maass

The rate of delignification of wood chips has been measured and found to conform to the monomolecular relation, provided that the standard method of penetration developed in this laboratory is used (3). Pretreatment of the wood chips by heating in liquid water at 130 °C. decreases the rate of delignification by subsequent cooking in sulphite liquor, and the rate no longer conforms to the monomolecular relation. Preheating of the wood to 130 °C. in the absence of water does not influence the rate of subsequent delignification. The results indicate the advantage of reducing the time of cooking, and a tentative explanation has been offered regarding the mechanism involved.

Author(s):  
E. M. Bulewicz ◽  
K. Go´ra ◽  
E. J. Anthony

Ash disposal and ash use are critical to FBC technology and in turn the reactions of FBC ash with water are key to both of these two issues. An effective ash reactivation technology would improve the economics for FBC firing of high-sulphur fuels. Similarly, controlled ash hydration before disposal is the standard method for conditioning FBC ashes when firing high-sulphur fuels with limestone addition. Ashes can be hydrated with liquid water or by steam under pressure and our earlier work suggested that when FBC ashes were hydrated by either method, the components derived from the coal and those from the sorbent can interact chemically. As a result, the amount of “free CaO” (defined as the proportion of CaO and Ca(OH)2, expressed as CaO) may change. Usually, “free CaO” increases after hydration, particularly under pressure. However, there is also evidence that some of the CaO, derived from excess limestone sorbent, enters into reaction with the ash components, possibly silica or silicates. Such processes must modify the exothermicity of the ashes with water and affect their subsequent behaviour. This implies that it is incorrect to assume, as has often been done, that the heat of the hydration process is directly proportional to the CaO content of the ash. Furthermore, the results presented here also strongly support the view that one must include these interactions when looking at FBC hydration.


1996 ◽  
Vol 76 (06) ◽  
pp. 0893-0896 ◽  
Author(s):  
P Kälebo ◽  
S Ekman ◽  
S Lindbratt ◽  
B I Eriksson ◽  
U Pauli ◽  
...  

SummaryThis study examines inadequacy rates for phlebography in two multicenter trials for the prevention of post-operative DVT and determines inter- and intra-observer variability in evaluating phlebograms. A total of 991 (I) and 385 (II) patients underwent bilateral phlebography in two studies of thromboprophylaxis. Phlebography was performed using a standard method designed to visualize and assess all deep veins. Each vein was scored as normal, DVT or inadequate by both local and central assessment. The study showed low inadequacy rates for phlebograms of 12.2% (121/991) and 6.5% (25/385). Inter-observer agreement (local vs. central assessment) was moderate in both studies (1:74.8%, Kappa-value 0.41; II: 82.6%, Kappa-value 0.51). Good intraobserver agreement (within the central assessment group) was observed (I: 88.8%, Kappa-value 0.75). This study demonstrates low inadequacy rates for phlebograms using a standardized methodology and superior intra-observer agreement compared to inter-observer agreement and supports the importance of central assessment of phlebograms in thromboprophylactic multicenter trials to reduce observer variability.


1961 ◽  
Vol 06 (03) ◽  
pp. 492-497 ◽  
Author(s):  
Janet C. Macpherson ◽  
R. M Hardisty

SummaryA modification of the thromboplastin screening test of Hicks and Pitney is described, in which the effect of surface contact on the test plasma is controlled by the addition of a suspension of kaolin to the incubation mixture before recalcification.Comparative studies show the modified test to give more reproducible results than the standard method.


1963 ◽  
Vol 44 (3) ◽  
pp. 475-480 ◽  
Author(s):  
R. Grinberg

ABSTRACT Radiologically thyroidectomized female Swiss mice were injected intraperitoneally with 131I-labeled thyroxine (T4*), and were studied at time intervals of 30 minutes and 4, 28, 48 and 72 hours after injection, 10 mice for each time interval. The organs of the central nervous system and the pituitary glands were chromatographed, and likewise serum from the same animal. The chromatographic studies revealed a compound with the same mobility as 131I-labeled triiodothyronine in the organs of the CNS and in the pituitary gland, but this compound was not present in the serum. In most of the chromatographic studies, the peaks for I, T4 and T3 coincided with those for the standards. In several instances, however, such an exact coincidence was lacking. A tentative explanation for the presence of T3* in the pituitary gland following the injection of T4* is a deiodinating system in the pituitary gland or else the capacity of the pituitary gland to concentrate T3* formed in other organs. The presence of T3* is apparently a characteristic of most of the CNS (brain, midbrain, medulla and spinal cord); but in the case of the optic nerve, the compound is not present under the conditions of this study.


2009 ◽  
Vol 5 (2) ◽  
pp. 53
Author(s):  
Philip B Adamson ◽  

There is increasing appreciation of the prevalence of sleep-disordered breathing (SDP) in heart failure. As we examine this patient population, the difficulties of determining success in the treatment of SDB are becoming evident. The apnoea–hypopnoea index (AHI) is the standard method of measuring both the severity of the disease and treatment success, but in itself is a composite of multiple components. This article examines both current and developing measurements in the treatment of SDB.


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