ALBERT

Notes: SUMMARY: Open-tubular gas chromatographic columns made from stainless steel tubing, coated with methyl silicone oil, give variable retention times for individual alcohols, dependent on the size of sample. This difficulty is largely overcome by using a small proportion of adsorption-reducing material with the methyl silicone. There are cases of reversal of peak order, caused by differences in column temperature or minor differences in the coating. However, with care, relative retention times are nearly constant and are helpful as an aid in identification of compounds. A procedure for precise comparison of the retention times of unknown fruit volatiles with known compounds is described. Relative retention times of representative compounds are given for twelve different stationary liquids.

Notes: The importance of light to the induction of nitrate reductase activity in barley (Hordeum vulgare L.) was studied. Activity in etiolated leaves in darkness stayed at a low endogenous level even while large amounts of nitrate were actively accumulated. Light was required for any increase in activity, though the requirement may be satisfied to a limited extent before nitrate is available. Nitrate reductase activity was induced in the dark in green leaves which had not previously had nitrate but were supplied nitrate at the beginning of the dark period. If the nitrate then made available was sufficient, nitrate reductase activity increased until the effect of the previous light treatment was exhausted. Activity then decreased even though nitrate uptake continued. Upon returning the leaves to light, enzymatic activity increased again, as expected.Nitrate uptake was eliminated as an experimental variable by giving dark-grown plants nitrate, then detaching the leaves for induction studies. Under these conditions light saturation occurred between 3600 and 7700 lux at exemplary periods of illumination. At intensities of 3600 lux and above, activity increased sharply after a 6-hour lag period. As light intensity was decreased below 3600 lux the lag period became longer. Thus, when sufficient nitrate was available, the extent of induction of nitrate reductase activity was regulated by light.

Notes: SUMMARY– Most egg products are pasteurized in continuous-flow equipment, but small quantities are more economically processed in a vat pasteurizer. By insulating itself, the surface foam in the vat process may be below pasteurization temperature for a significant part of the holding time and salmonellae in the foam may survive. Using a 100-gal vat, we generated foams on 5 egg products and measured foam temperatures during pasteurization. Maximum jacket temperature was held to 160°F and no product burn-on was observed in the vat. All products were held above their respective pasteurization temperatures for 30 min. The minimum temperature of a 6.5-in. liquid whole egg foam was below pasteurization temperature for 11 min after start of pasteurization. The delayed heating effect of a 1-in. foam on sugared yolk (10% sucrose by weight) was 13 min. Yolk and salted yolk (10% salt by weight) foams were below liquid temperature during heating; however, in both cases liquid and foam reached pasteurization temperature simultaneously. Minimum temperature of plain egg white foam (pH 9.0) did not reach pasteurization temperature during the holding period. In vat pasteurization, the holding time begins when the liquid reaches pasteurization temperature, and the holding time should be long enough for both foam heating and pasteurization of foam. Except for egg white, about 15 min was required to heat foam to pasteurization temperature. Adding 15 min for pasteurization of the foam yielded a total holding time of 30 min, with the temperature of pasteurization established on the basis of the 15-min holding time for the foam as follows: liquid whole egg, 133°F; yolk and yolk blends, 135°F; sugared and salted yolk, 139°F. With egg white, foam heating times were in excess of 30 min, and vat pasteurization, with a holding time of 30 min, was not effective.

Notes: SUMMARY: A Penicillium roqueforti strain produced maximal amounts of lipase when grown in 0.5% casitone-1% Proflo broth, pH 5.5, at 27°C. Addition of butteroil, com oil or olive oil to the growth medium inhibited the lipase production. Under pH stasis the partially purified lipase of P. roqueforti had an optimum pH of 8.0 and an optimum temperature of 37°C. Maximum lipolytic activity occurred with 5% butteroil emulsion as the substrate. Manganese chloride and magnesium chloride stimulated the enzyme activity. Calcium, sodium and potassium sale had no appreciable effect on lipolysis; silver, mercury and zinc salts were inhibitory. The lipase was thermolabile, being inactivated completely within 10 min at 50°C. The lipase hydrolyzed tributyrin, tricaprylin, tricaprin, tripropionin and triolein in decreasing order.

Notes: For several years resistance-capacitance networks have been used to simulate aquifers. Most reported work has been concerned with fast time analogues in which the period under consideracign is represented in micro-seconds. However the alternative slow time analogue has many advan tages since the electrical experiment takes several seconds. This results in simpler equipment and simpler experimental techniques.The paper concentrates on the practical aspects or the slow time analogue giving details of the components, describing a method of simulating wells and recharge and comparing measuring instruments. The techniques are illustrated by a simplified example.

Notes: In the Maumee River Basin of northwestern Ohio the principal source of ground water is the Silurian-Devonian carbonate aquifer. The use rate of ground water from this aquifer could rapidly increase many fold in the near future. This situation demands quantitative information on the resource potential of the aquifer, if proper development is to be encouraged.A relationship between ground-water use and recharge rates through an analysis of the cones of influence is demonstrated in this paper. Computed recharge rates for the cones of influence vary from 6,800 to 75,300 gpd/sq mi, and the variation is systematic in that the higher recharge rates correlate with the higher pumpage rates. Recharge rates appear to have an upper limit of approximately 100,000 gpd/ sq mi, which corresponds to a maximization of the vertical hydraulic gradient. Although maximization of the vertical hydraulic gradient is impossible to achieve for a given cone of influence, it can be approached by lowering the piezometric surface of the aquifer by increasing the pumpage rate.Assuming that the safe yield of an aquifer is equivalent to the rate of recharge, this study demonstrates that development of an aquifer can increase many times its potential.

Notes: Summary. The rates of degradation of three triazine and two uracil herbicides were followed at 13·2 and 31·2°C in one soil. Soil was treated with 8 ppm of 2-chloro-4-ethyl-amino-6-isopropylamino-1,3,5-triazine (atrazine), 2-chloro-4,6-bisethylamino-1,3,5-triazine (simazine), 2-mcthylthio-4-ethylamino-6-isopropylamino-1,3,5-triazine (ametryne), 3-sec-butyl-5-bromo-6-methyluracil (bromacil) and 3-tert-butyl-5-chloro-6-methyluracil (terbacil) and monthly samples analysed chemically to determine the amounts remaining. Evaluation of the rate constant at two temperatures permitted calculation of the energy of activation from the Arrhenius equation.It was determined to a first approximation that soil degradation followed a first order rate law with no lag period and that the rate could be related to molecular structure. The energies of activation in kcals/mole were: atrazine 10-8, simazine 9-2, ametryne 6-1, bromacil 3-0, and terbacil 6-1. These values suggest breakage of the common carbon-chlorine bond in atrazine and simazine but breakage of a different bond in ametryne. Examination of bond energies and known mechanisms of breakdown for triazines supported the hypothesis of breakage of the bond at the two position. The data on decomposition of the uracils indicate that the carbon-halogen bond was broken in each molecule.Dégradation des triazines et des uraciles herbicides dans le solRésumé. Les taux de dégradation de trois triazines et de deux uraciles herbicides ont été observés α 13,2 et 31,2° C dans un sol. Ce sol a été traitéà la concentration de 8 ppm avec la 2-chloro-4-éthyIainino-6-isopropylamino-1,3,5-triazine (atrazine), la 2-chloro-4,6-biséthylamino-l,3,5-triazine (simazine), la 2 méthylthio-4-éthylamino-6-isopropylamino-1,3,5-triazine (amétryne), le 3-sec-butyl-5-bromo-6-méthyluracile (bromacil) et le 3-tert-butyl-5-chloro-6-méthyluracile (terbacil). Des échunlillons ont été analysés chimiquement tous les mois pour déterminer les résidus. L'évaluation du taux constant à deux températures a permis le calcul de l'energie d'activation d'aprés l'équation d'Arrhenius.Selon une premiére approximation, la dégradation a suivi une loi de taux de premier ordre sans période de retard et le taux peut être reliéà la structure moléculaire. Les énergies d'activation en kcals/mole furent: atrazine 10,8, simazine 9,2, amétryne 6,1, bromacil 3,0 et terbacil 6,1. Ces valeurs suggérent une rupture d'une liaison carbone-chlore dans I'atrazine et la simazine mais la rupture d'une liaison différente dans l'amétryne. L'examen des énergies de liaison et des mécanismes connus de dégradation pour les triazines amène à formuler l'hypothése de la rupture d'une liaison en position deux. Les résultats relatifs aux uraciles indiquent tjue la liaison carbone-halogéne a été rompue dans chaque molécule.Der Abbau von Triazin- und Uracilherbiziden im BodenZusammenfassung. Die Abbaurate von 3 Triazin- und 2 Uracilherbiziden im Boden wurde bei 13,2 und 3l,2°C untersucht. Aus dem mit 8 ppm 2-Chlor-4-athylamino-6-isopropylamino-1,3,5-triazin (Atrazin),2-Chlor-4,6-bisathylamino-[3,5-lriazin (Simazin), 2-Methyllhio-4-athylamino-6-isopropylamino-1,3,5-triazin (Ametryn), 3-scc-Butyl-5-brom-6-methyluracil (Bromacil) und 3-tert-Butyl-5-chlor-6-methyluracil (Terbacil) behandelten Bodenrückständen wurden monatlich Proben entnommen und chemisch die Rückstände erniittelt. Die Bestimmung der Geschwindigkeitskonslantcn bei zwei Temperaturen eriaubte die Borechnung der Aktivicrungscnergic nach der Arrhenischen Gleichung.In erster Annäierung verlief der Abbau als Prozcss erster Ordnung ohne Latenzphase und die Abbaurate stand in Beziehung zur Struktur des Molekuls. Die Aktivierungsenergie betrug fur Atrazin 10,8, Simazin 9,2, Ametryn 6,1, Bromacit 3,0 und Terbacil 6,1 kcal/Mol. Diese Werte lassen für Simazin und Atrazin einen Bruchder der bcide Herbizide gemeinsamen Kohlensloff-Chlorbindung vermuten, wahrend im Falle des Ametryn eine andere Bindung hiervon betroffen war. Die Prufung der Bindungsenergien und der bekannten Abbau me chanismen bei Triazinen unterstCitzcn die Hypothcse, dass der Bruch in der 2-Position erfolgte. Die Ergebnisse fur die Uracile deuten darauf hin, dass bei beiden Moleküien der Abbau an der Kohlenstoff-Halogenbindung ansetzte.