High-pressure liquid chromatographic identification of drugs used in management of arthritis

A screening procedure was developed for the identification of drugs used in the clinical treatment of arthritis. Each glucocorticoid, nonsteroidal anti-inflammatory agent, or tranquilizer was characterized by its retention on a reversed-phase high-pressure liquid chromatographic column and by the ratio of the response of dual UV detectors (254 and 280 nm). Although the retention times of all 14 drugs examined were less than 4 min. each drug could be distinguished easily from the other drugs in the series.     

Minoxidil reduces pulmonary vascular resistance in dogs and cattle

Minoxidil has a direct dilator effect on the systemic arterial smooth muscle. It is potentially an important drug in the treatment of systemic hypertension, especially when combined with beta blockade, which is used to control the associated tachycardia and increase in cardiac output. However, recent observations have suggested that minoxidil might cause pulmonary hypertension. Consequently, we examined the acute effect of monoxidil and propranolol, separately and in combination, on the pulmonary vasculature of the anesthetized dog and the awake calf during normoxia and hypoxia. In both species minoxidil reduced pulmonary vascular resistance. In the dogs this appeared to be the result of a direct action on the pulmonary vascular smooth muscle and in the cattle it was secondary to beta-receptor stimulation. Propranolol alone in the cattle increased the pulmonary pressor response to hypoxia. While we have not examined the possibility that chronic administration of minoxidil might cause pulmonary hypertension by some other mechanism, our acute studies suggest that it reduces, rather than increases, pulmonary vascular resistance. Furthermore, there seems to be a species difference in the mode of its action in dogs and cattle.     

Prediction of heat and smoke movement in enclosure fires

In order to understand the response of a detector to a given fire in an enclosure, it is necessary to relate the local thermal and aerosol characteristics actually sensed by the detector to the physical and geometrical properties of the fire and the enclosure. This paper presents computations designed to predict the evolution of the size distribution of smoke aerosol as it ages, as well as the large-scale air movement and temperature fields generated by an enclosure fire.

The computations contain three main ingredients: first, a finite difference solution for the air movement and temperature generated by a prescribed source of heat used to represent a fire in a closed form; second, the computer evaluation of an exact solution to the ageing equation correspond to the evolution of an experimentally observed size distribution; and third, a particle tracking scheme which permits the smoke aerosol to be followed in space and time as it gradually fills the room. No nonphysical empirical parameters (e.g. turbulence models) are employed in these calculations. The mathematical and physical models are summarized briefly, but most emphasis is placed on displaying results. Sample calculations are presented, comparisons are made with relevent experiments, and predictions of the local environment experienced by a detector due to the occurrence of an enclosure fire are shown.     

Effect of protein-to-fat ratio of milk on the composition, manufacturing efficiency, and yield of cheddar cheese

Twenty-three Cheddar cheeses were prepared from milks with a protein content of 3.66% (wt/wt) and with different protein-to-fat ratio (PFR) in the range 0.70 to 1.15; the PFR of each milk differed by 0.02. For statistical analysis, the 23 cheeses were divided into 3 PFR groups: low (LPFR; 0.70 to 0.85), medium (MPFR; 0.88 to 1.00) and high (HPFR; 1.01 to 1.15), which were compared using ANOVA. The numbers of PFR values in the LPFR, MPFR, and HPFR groups were 9, 7, and 7, respectively. Data were also analyzed by linear regression analysis to establish potentially significant relationships among the PFR and response variables. Increasing PFR significantly increased the levels of cheese moisture, protein, Ca, and P, but significantly reduced the levels of moisture in nonfat substances, fat-in-DM, and salt-in-moisture. The percentage of milk fat recovered in the LPFR cheese was significantly lower than that in the MPFR or HPFR cheeses. In contrast, the recovery of water from milk to the LPFR cheese was significantly higher than that in the MPFR or HPFR cheeses. Increasing the PFR led to a significant decrease in the actual yield of cheese per 100 kg of milk but a significant increase occurred in the normalized yield of cheese per 100 kg of milk with reference values of fat plus protein (3.4 and 3.3%, wt/wt, respectively). The results demonstrate that alteration of the PFR of cheese milk in the range 0.70 to 1.15 has marked effects on cheese composition, component recoveries, and cheese yield.     

Experimental characterization of the heat transfer in a free-falling-particle receiver

This paper describes the measurements performed on a Free Falling curtain of spherical beads being irradiated in a high-flux solar furnace. The curtain of spherical beads is part of a direct absorption solar receiver concept, which replaces the conventional water and steam receiver (DAR) and is potentially more efficient and less expensive than a conventional receiver. To adequately describe a DAR a series of experiments have been designed and implemented to measure radiative heat flux and particle temperatures. The extinction coefficient for the DAR bead curtain has also been measured. These data and results along with a new method for measuring bulk bead temperature will be discussed. A method is also described which uses the angular distribution of incoming radiative heat flux to estimate the incoming intensity field.