A study of solid circulation rate in a circulating fluidized bed

An experimental investigation under cold condition was made to study the effects of some operating/design parameters and non-mechanical L valve configuration on the solid circulation rate in a 4.5 m tall, 0.15 m diameter circulating fluidized bed with riser flow rate varying from 1400 litres/min to 2000 litres/min and bed inventory from 15 kg to 25 kg of sand of average sizes 200 μm, 400 μm and 500 μm. Solid circulation rate was estimated by measuring velocity of sand particle travelling through a vertical Perspex tube section at the bottom of the return leg. It was found to be in the range of 2.8 to 12.3kg/m²s, 0.07 to 9.1kg/m²s and 0.12 to 2.23kg/m²s for sand sizes of 200 μm, 400 μm and 500 μm, respectively for a horizontal L valve. Two mathematical correlations have been developed from the experimental results to predict solid circulation rate as a function of riser flow rate, aeration flow rate, total bed inventory and particle size used.     

Comparative fate of 1,1-diphenylethylene (DPE), 1,1-dichloro-2,2-bis(4-Chlorophenyl)-ethylene (DDE), and pentachlorophenol (PCP) under alternating aerobic and anaerobic conditions

First, annual cost of electronic filing of medical images were calculated and compared with that of film storage in two hospitals under different conditions. Storage of medical images using a pixel size of 100 microns x 100 microns and 2-byte depth on the 130 mm, 650 MB magneto-optical disks costs with four times as much as the cost for film storage. However, 175 microns x 175 microns 12 bits combined with implementation of lossless compression would reduce the cost to a level equal to that for films storage. Doubled or tripled densities of MOD will improve the cost ever further. Second, the effectiveness of Hospital Information System/Radiological Information System (HIS/RIS) was evaluated. Examination time, film delivery time and the total turn-around time was markedly shortened by more than 23 hours on average. Our measurement method employing IC cards in pre-post HIS/RIS/PACS procedures is generally applicable to other hospitals. Third, to determine the optimal method of maximizing the efficacy of diagnostic imaging, 260 questionnaires were sent to the staff of 13 university hospitals. Every situation was described by both a radiologist and the physician who ordered the examination and received the reports and images. The level of technical efficacy and diagnostic accuracy of radiology strongly influenced the diagnostic thought processes of the physician.     

Professionally-led support groups for cancer patients: an intervention in search of a model

OBJECTIVE: The objective of this review was to evaluate the clinical and research literature on professionally-led support groups for cancer patients and to propose an approach that would address patients' needs from diagnosis through survivorship. METHOD: Computerized and manual searches, including Medline and Psychlit searches, were completed for reviews of the literature. Twelve research studies were identified that met our criteria for in-depth review. A clinical model emerged from discussions of an oncology study group based on theoretical formulations and clinical experience with oncology patients. RESULTS: We found that recent research suggests that professionally-led support groups are increasing in number and that participation in such groups seems to enhance patients' quality, and possibly even quantity, of survival. Despite this, little effort has been made to determine what type of group may be appropriate for which patients and when in their course of care. CONCLUSIONS: If psychosocial intervention, in the form of professionally-led support groups for cancer patients, is to be more effective, it should be guided by a model which takes into consideration the changing needs and concerns of patients over the course of illness and, in many cases, recovery. The authors present an outline delineating what such a model might entail.     

The effect of exchanger inhibitory peptide (XIP) on sodium-calcium exchange current in guinea pig ventricular cells

While the osteopenia associated with oestrogen deficiency is thought to arise from a relative defect in bone formation with respect to resorption, oestrogen administration itself leads to a decrease, rather than an increase, in bone formation. This decrease in bone formation, which arises from oestrogen's inhibitory effect on bone turnover, presumably masks any underlying tendency of oestrogen treatment towards stimulation of bone formation. To investigate this further, we have examined the early effect of discontinuing the administration of oestradiol-17 beta (OE2; 40 micrograms/kg) on bone formation indices in ovariectomized 13-week-old rats, before the turnover-induced increase in formation occurs. Histomorphometric indices were assessed at the proximal tibial metaphysis 0, 7, 10, 13 and 16 days following discontinuation of OE2 treatment. Measurements of body weight, uterine weight and longitudinal growth rate confirmed that there were rapid effects of OE2 deficiency on these parameters. We could detect no significant increase in bone resorption, as measured by osteoclast surface and number, until 16 days after ending treatment with OE2; this was coincidental with a reduction in bone volume. Shorter periods of OE2 deficiency were associated with a marked decrease in bone formation, as assessed by dynamic histomorphometric indices. This inhibition of bone formation was largely due to a reduction in double fluorochrome-labeled trabecular surfaces, which were decreased by approximately 70%. We conclude that ending OE2 administration in ovariectomized rats caused a striking decrease in trabecular bone formation, if such indices are assessed prior to the subsequent turnover-induced increase in formation.(ABSTRACT TRUNCATED AT 250 WORDS)     

The metabolic fate of [3H]estradiol in relation to dietary intake of boron in ovariectomized rats

It has been reported that boron (B) deprivation reversibly lowers plasma estradiol levels in postmenopausal women. In order to establish whether this reflects disturbances in the estrogen catabolic pathway and in particular in catechol estrogen metabolism, the influence of dietary B on the catabolism of [3H]estradiol-17 beta has been studied in ovariectomized rats. Rats were given diets containing < 0.1 or 40 mg B.kg-1, ovariectomized and then infused with [3H]estradiol-17 beta using osmotic pumps. Analysis of urine samples for conjugated, catechol and non-catechol estrogens did not reveal any effects of B on the recovery or the metabolic fate of tritium from the infused estradiol. These results do not therefore support the proposal that B influences estrogen catabolism by interacting with catechol estrogens.