A Quarterly Model Of The Beef, Pork, Sheep, Broiler and Turkey Sectors

Livestock and meat, producers, processors -and consumers need to continually adjust plans as expected prices change and-affect - i-- expected relative profits and utility* from alternative uses\u27 or the resources they manage.- These decision makers demand information and analysis of anticipated-product-supplies- and price levels.

Spray drying costs in low-volume milk plants

Since World War II several developments have given impetus to a shift from marketing farm-separated cream to marketing whole milk. The increased consumer demand for nonfat dry milk, the government price-support program, the introduction of drying equipment small enough to make drying feasible for small plants, and farmers preferences have all had a share in inducing plants to shift from a butter manufacturing operation to a butter-powder operation.https://lib.dr.iastate.edu/specialreports/1016/thumbnail.jp

Acoustic emphasis in four year olds

Acoustic emphasis may convey a range of subtle discourse distinctions, yet little is known about how this complex ability develops in children. This paper presents a first investigation of the factors which influence the production of acoustic prominence in young children’s spontaneous speech. In a production experiment, SVO sentences were elicited from 4 year olds who were asked to describe events in a video. Children were found to place more acoustic prominence both on ‘new’ words and on words that were ‘given’ but had shifted to a more accessible position within the discourse. This effect of accessibility concurs with recent studies of adult speech. We conclude that, by age four, children show appropriate, adult-like use of acoustic prominence, suggesting sensitivity to a variety of discourse distinctions

The Circumstellar Environment of High-Mass Protostellar Objects: IV. C17O Observations and Depletion

We observe 84 candidate young high-mass sources in the rare isotopologues C17O and C18O to investigate whether there is evidence for depletion (freeze-out) towards these objects. Observations of the J=2-1 transitions of C18O and C17O are used to derive the column densities of gas towards the sources and these are compared with those derived from submillimetre continuum observations. The derived fractional abundance suggests that the CO species show a range of degrees of depletion towards the objects. We then use the radiative transfer code RATRAN to model a selection of the sources to confirm that the spread of abundances is not a result of assumptions made when calculating the column densities. We find a range of abundances of C17O that cannot be accounted for by global variations in either the temperature or dust properties and so must reflect source to source variations. The most likely explanation is that different sources show different degrees of depletion of the CO. Comparison of the C17O linewidths of our sources with those of CS presented by other authors reveal a division of the sources into two groups. Sources with a CS linewidth >3 km/s have low abundances of C17O while sources with narrower CS lines have typically higher C17O abundances. We suggest that this represents an evolutionary trend. Depletion towards these objects shows that the gas remains cold and dense for long enough for the trace species to deplete. The range of depletion measured suggests that these objects have lifetimes of 2-4x10^5 years.Comment: 18 pages. Accepted for publication in Astronomy & Astrophysic

Multi-spin dynamics of the solid-state NMR Free Induction Decay

We present a new experimental investigation of the NMR free induction decay (FID) in a lattice of spin-1/2 nuclei in a strong Zeeman field. Following a pi/2 pulse, evolution under the secular dipolar Hamiltonian preserves coherence number in the Zeeman eigenbasis, but changes the number of correlated spins in the state. The observed signal is seen to decay as single-spin, single-quantum coherences evolve into multiple-spin coherences under the action of the dipolar Hamiltonian. In order to probe the multiple-spin dynamics during the FID, we measured the growth of coherence orders in a basis other than the usual Zeeman eigenbasis. This measurement provides the first direct experimental observation of the growth of coherent multiple-spin correlations during the FID. Experiments were performed with a cubic lattice of spins (19F in calcium fluoride) and a linear spin chain (19F in fluorapatite). It is seen that the geometrical arrangement of the spins plays a significant role in the development of higher order correlations. The results are discussed in light of existing theoretical models.Comment: 7 pages, 6 figure

Manufacturing costs: whole milk creameries

Dairying in Iowa has been an essential part of most farm operations. The skim milk resulting from farm separation of the cream has been a useful supplement to com in the swine feeding operations which constitute the most important single phase of Iowa agriculture. Because of this relationship between dairying and hog farming, the dairy processing industry in Iowa has been based primarily on one product, butter, and most of this has been manufactured in creameries receiving only farm-separated cream. Many of these creameries were established 50-60 years ago when the roads and transportation facilities of the time dictated the need for many local plants which tended to remain small. Over the years this system of dairy marketing has persisted in Iowa. In other important dairy sections of the United States, there has been a trend to concentrate dairy processing in larger plants manufacturing a number of different products.https://lib.dr.iastate.edu/specialreports/1014/thumbnail.jp