Low Water Volume Research Articles

WATER—THE MAJOR NUTRIENT

Water metabolism is a major problem in infants of very low birth weight. Their surface is proportionally larger, they have a relatively low intracellular water volume and a high extracellular and total body volume. Kidney function is immature compared to bigger infants, and the neuroendocrine function is also immature. Finally the large surface and the high skin permeability causes a very high insensible water loss in the early neonatal period. Water imbalance presents itself as either dehydration or overhydration. Dehydration gives poor peripheral--and renal circulation and thereby decreased renal function with acidosis. Furthermore hyperosmolar dehydration will give increased hematocrit and blood viscosity and hyperbilirubinaemia. Excessive administration of water will give oedema and congestive heart failure and possibly an increased risk for patent ductus arteriosus, bronchopulmonal dysplasia and necrotising enterocolitis. The evaporative water losses varies according to the thermal environment and air humidity and it is therefore impossible to give narrow limits for the daily water intake. Clinical examination, frequent controls of body weight (twice daily) and measurements of urine volume and osmolarity serve as guide lines. Yet inappropriate secretion of ADH may confuse the value of measuring urine osmolarity. Finally a neonatal weight loss of 5-10% may be beneficial as a decrease in extracellular water may lessen the working load of the heart and therefore possibly lessen the risk for a patent ductus. Renal immaturity in handling sodium reabsorption on the other hand, will often give an excessive dehydration. For this reason about 2 mmol Na/kg body weight should be given daily to very low birth weight infants from the fourth day of life to the 3rd-4th week if the baby is on human milk or a low salt formula.

Sampling of Broiler Carcasses for Salmonella with Low Volume Water Rinse

The uneven distribution and low numbers of salmonella usually present on broiler carcasses make whole carcass rinsing the most sensitive sampling procedure for detecting this organism on the raw product. However, 270 ml of water or medium has been the smallest volume used in past published research. We found that 100 ml was adequate to recover Salmonella typhimurium, S. California, or S. montevideo from freshly processed broiler carcasses that had been inoculated with the organism at the rate of 50 cells/carcass. When carcasses were inoculated with 20 cells of S. heidelberg, then stored at −23 C for 3 or 6 months, sampling with 100 ml was adequate to detect the organism on all carcasses. The advantages of using the smallest volume of rinsing medium that will consistently lead to detection of salmonella present are: 1) less enrichment medium is required, 2) less incubator space is required, and 3) the concentration of cells in the selective enrichment medium at the end of incubation is greater; hence, the greater are the chances of salmonella detection when a drop is subsequently transferred to the selective plating medium.

A chelating agent - activated carbon - PIXE procedure for sub-ppb analysis of

By combining suitable water preconcentration techniques and Particle-Induced X-ray Emission analysis (PIXE), we have developed a procedure for multielemental sub-ppb water analysis. The preconcentration step consists of adsorbing the metals in the form of organic chelates onto activated carbon, which is pressed to a tablet and then analysed by PIXE. For very low concentrations and small volumes of water, a “mini-tablet” technique of sample preparation is employed. The versatility of the chelating-adsorption-PIXE procedure is demonstrated for several different kinds of water.

Low velocity foam flush drilling : England, B, Hands-England Ltd, Herts. GB 2F, 3R Ground Engng, V9, N3, Apr. 1976, P24–25

The author gives a brief account of the use of foam in removing cuttings from a borehole during drilling. The system gives low up-hole velocity, retains cuttings in suspension without the need for a dense liquid, utilizes only low volumes of water and compressed air and employs a flushing medium that resists percolation into porous or fissured zones. Details are given of the equipment and method of operation. The foam mixture and wall-stabilising polymer additives generally necessary are described and it is noted that both are completely non-toxic and biodegradable. /TRRL/

Dormancy studies in seed of Avena fatua. 7. The effects of light and variation in water regime on germination

Light can regulate the germination of seeds of Avena fatua L. In low volumes of water, seeds are inhibited by white light and in high volumes they are promoted, when compared to seeds in darkness. Blue, red, and far-red light also inhibited germination of seeds in low volumes of water; in high volumes of water there were no differences between these three bands of light and darkness. Degree of dormancy and presence or absence of hulls and of gibberellin all interacted with water status of the caryopsis and light to modify germination. Suppression of germination by white light induced a concomitant reduction in the rate of increase of water potential in these seeds compared with similar seeds germinated in darkness.

Laboratory and field tests of zineb and other fungicides against downy mildew of lettuce (Bremia lactucae Regel)

SUMMARYIn laboratory tests on young lettuce plants, the protection provided by sprays of zineb wettable powder against artificial inoculations with Bremia lactucae was less than that obtained with tank‐mix zineb, and with several other dithiocarbamates and related fungicides.Experiments on autumn lettuce in the field also showed that tank‐mix zineb was more effective than the wettable powder. On winter lettuce in frames, however, zineb wettable powder gave control similar to or better than that given by any of the other materials tested.Infection in most of these outdoor experiments was not heavy. None of the fungicides gave very high control or markedly increased the number of hearted or marketable plants.When zineb wettable powder was sprayed on autumn lettuce at the rate of 2 lb./acre it gave similar disease reductions whether applied in low, medium or high volumes of water.

STUDIES OF THE NIANTIC RIVER, CONNECTICUT WITH SPECIAL REFERENCE TO THE BAY SCALLOP, AEQUIPECTEN IRRADIANS1

The Niantic River is a shallow estuary with a tidal prism equal to half the mean low water volume of the basin, and with a twelve‐hour freshwater inflow of less than 3% of the tidal prism. The tidal waters mix offshore with the waters of eastern Long Island Sound, rich in plankton and nutrients. The estuary functions as an ecological concentrating system as the dense and varied populations of grazers consuming the food of these tidal waters benefit from the resources of offshore mixing in addition to the production endemic to the estuary.The disappearance of the eelgrass, Zostera marina, with the epidemic of the early 1930's permitted better circulation near the river bottom. Apparently this was advantageous to the bay scallop, which thereafter became the predominant sessile grazer with a production calculated at 2.2g C/m2/yr. Anchorage previously offered by eelgrass for the early setting stages of scallops was subsequently available through the abundance of small branching algae.The brief life history of a bay scallop is outlined on its shell as the surface laid down in each successive year appears rougher or more “weathered” than that formed the year before. By following this differentiation of shell surface, annual rings were determined with more certainty than in earlier studies. Though the time of year when the differentiation of shell surface commences may vary with populations and even with year classes, it is probably due to a common cause, seasonal change in growth rate being most likely. The life history interpreted from shells from Indian middens was essentially the same as observed for living scallops.The scallops of the Niantic River spawn from mid‐June through July. The young of a given year reach maturity and are the chief brood stock of the succeeding spawning season. Mortality rates for all sizes are high during all seasons and few individuals survive to the time of second spawning.The estuaries in which the bay scallop occurs have the following hydrographic features: the ratio of tidal volume to river flow is high, thus the salinity remains high; the basin is relatively shallow, with a resulting high ratio of tidal volume to the volume at low water; the circulation is such as to retain the planktonic scallop larvae in sufficient numbers for reseeding and to provide an adequate supply of planktonic food, perhaps in part supplied by offshore waters.

Experiments in Liquid Atomization by Air Streams

Water is atomized by a high-velocity air stream using various methods of injection and water nozzle positions. Low water volume rates and velocities, air velocities up to acoustic, and ratios of air volume to water volume rates up to 25 000 were utilized. Results indicate water injection into region of maximum velocity, parallel to the air flow gives highest degree of atomization under similar conditions. Comparison is made with the Tanasawa-Nukiyama correlation and discrepancies in droplet sizes at high air velocities are found and discussed.

AN ACID CITRATE-DEXTROSE SOLUTION WITH LOW WATER VOLUME AND LOW DEXTROSE CONCENTRATION 1

AN ACID CITRATE-DEXTROSE SOLUTION WITH LOW WATER VOLUME AND LOW DEXTROSE CONCENTRATION 1