Universal few-body physics in a harmonic trap

Few-body systems with resonant short-range interactions display universal properties that do not depend on the details of their structure or their interactions at short distances. In the three-body system, these properties include the existence of a geometric spectrum of three-body Efimov states and a discrete scaling symmetry. Similar universal properties appear in 4-body and possibly higher-body systems as well. We set up an effective theory for few-body systems in a harmonic trap and study the modification of universal physics for 3- and 4-particle systems in external confinement. In particular, we focus on systems where the Efimov effect can occur and investigate the dependence of the 4-body spectrum on the experimental tuning parameters.Comment: 20 pages, 10 figures, final version, new references adde

Volatile acid production of S. lacticus and the organisms associated with it in starters

The organisms ordinarily classed as S. lacticus (or Bact. lactis acidi) represent a group that is extremely important in the field of dairying. Altho they are responsible for a great deal of loss, since they are the principal type that sours milk and cream and thus spoils for certain purposes large quantities of these materials, they are ordinarily classed as the desirable lactic acid bacteria because of the role they play in the making of certain dairy products

A bacteriological study of blue milk

In October, 1913, the receipt of a sample of blue milk by the dairy section of the Iowa Agricultural Experiment Station prompted an investigation of this uncommon phenomenon. Careful study of the organism involved proved it to be Bac. cyanogenes, the same organism that has been isolated in other instances of blue milk. As far as is known, this organism is entirely harmless and milk which is turned blue by it is objectionable only on account of its color

Studies on ropiness in cultures of Streptococcus Lactis

The production of a ropy condition in milk is a character occasionally shown by the organisms of the S. lactis group. \u27l\u27his character is, however , one that is rather inconstant and its gain or loss or a variation in its extent is frequently noted in the laboratory in cultures that are very probably pure. In starters also, where the S. lactis type of organisms makes up the largest percent of the flora, the development of ropiness occasionally occurs and when ropy starters are carried thru a number of transfers this ropiness sometimes disappears. The change from ropy to non-ropy cultures of S . lactis and the reverse have recently been studied by plating out one of the types, picking colonies and looking for the other among the cultures developing; the results obtained are herein reported

Bacteriological studies on two yellow milk organisms

The different milk constituents vary greatly in their susceptibility to the action of the bacteria that make up the flora commonly found in milk. At ordinary temperatures in raw milk, the lactose is soon attacked and acid formed, but if the acid producing organisms are destroyed by some such procedure as heating, pronounced changes soon take place in the casein. The fat is one of the milk constituents that is more resistant to bacterial action, yet even in it striking changes are observed under certain conditions. Some of the common milk organisms, even some of the acid producing types, are able to change the fat, altho frequently considerable periods of time are required for such action

Sources of the flavor in butter

Flavor is one of the important points considered in determining the quality of butter. The sources of this flavor and the exact way in which it is developed are questions which have long been of weight with investigators interested in dairying. The experiments herein reported were carried out with the idea of applying\u27 to these problems some of the information recently secured in a study of starters

Studies on abnormal evaporated milk

Evaporated milk, which depends for its keeping quality on the destruction of the con tamed micro-organisms by heat, occasionally spoils because of the presence of one or more organisms that resist the exposure employed in the sterilizer. The milk may undergo coagulation, gas formation or various other changes depending on the organism or organisms present. In this paper an unusual type of spoiling, mainly evident as an abnormal flavor and odor, altho there sometimes was coagulation, is reported and the organism causing it is described

Studies of the formation of gas in milk

The gassy fermentation of milk has recently been observed a number of times in the Iowa State College creamery, particularly in the milk set for the manufacture of various types of soft cheese. The isolation and study of the causal organism or organisms was undertaken in several cases and the results obtained, together with a brief statement of the cases investigated, are herein presented

Studies on the clarification of milk

The desirability of producing a perfect milk is now generally recognized. The production of milk in which there is only an extremely small amount of dirt is, however, an expensive process and one which ordinarily necessitates an increased price. The desire to supply milk of a good quality at a moderate price has resulted in the use of various methods of handling milk. The centrifugal separator has been recognized since its introduction as a means of removing a part of the undesirable elements from milk; however, objections have been raised to the use of these machines and recently centrifugal machines designed especially for the removal of foreign material from milk, known as milk clarifiers, have been put upon the market. Milk clarifiers, if their increasing use can be taken as an index, are destined to hold an important place in the modern milk plant. The desire to secure additional information regarding the effect of clarification on the bacterial content of milk, the cell content, and the bacterial content where pasteurization is used, as well as to secure data on the bacterial and cell contents of the clarifier slime, has led to the work herein reported