4,537 research outputs found
Somatic Cells and High Bacteria Counts: How to Deal With Them
Under the current component pricing system dairy producers are paid by the amount of components (protein, butterfat, other solids) that end up in their milk tanks every day. On top of these, premiums increase their gross revenue, which include over-order premiums, quality premiums, and volume premiums. Quality premiums are paid to encourage producers to supply high quality milk and vary depending on the individual processor. Although quality premiums might sometimes seem small, we usually fail to understand that high somatic cell counts (SCC) are closely associated with milk production loss and thus milk volume premiums. Concentration of components, total milk shipped, and milk quality as represented by SCC and bacteria counts are among the things producers can control
Effect of debris size on the tribological performance of thermally sprayed coatings
This research aims to assess the effect of the debris particle size on the tribological performance
and lubrication regime parameters of a Ni-based alloy coating. This is a key industrial problem,
and its resolution can contribute to better machine endurance and proper maintenance.
The debris particles are simulated by hard Al2O3 particles of size ranging from nanometers to 45
ÎĽm and dispersed in an oil lubricant. The coating studied is NiCrBSi deposited by flame spraying
technique followed by the Surface Flame Melting (SFM) process. The counterpart disk sample
was fabricated from quenched and tempered F-5220 steel (in line with A681(O1) ASTM). This
pair was tested under linear sliding contact.
Our results show that the addition of alumina particles contributes to a significant increase in
wear, particularly for the largest particles (micrometric size). In the case of micrometric particles,
it is possible to observe the formation of higher surface roughness, numerous microgrooves, and
plastic flow of NiCrBSi coating perpendicular to the sliding direction, resulting in higher loss of
volume.
It was found that the actual surface roughness (obtained as a function of the debris particle size)
allows better identification and prediction of the lubrication regime for wear processes instead of
the traditional approach that uses the initial surface roughness as a parameter
On the consistency of the Horava Theory
With the goal of giving evidence for the theoretical consistency of the
Horava Theory, we perform a Hamiltonian analysis on a classical model suitable
for analyzing its effective dynamics at large distances. The model is the
lowest-order truncation of the Horava Theory with the detailed-balance
condition. We consider the pure gravitational theory without matter sources.
The model has the same potential term of general relativity, but the kinetic
term is modified by the inclusion of an arbitrary coupling constant lambda.
Since this constant breaks the general covariance under space-time
diffeomorphisms, it is believed that arbitrary values of lambda deviate the
model from general relativity. We show that this model is not a deviation at
all, instead it is completely equivalent to general relativity in a particular
partial gauge fixing for it. In doing this, we clarify the role of a
second-class constraint of the model.Comment: The wording has been revised in general, specially in abstract,
introduction and conclusions. No changes in results. Version published in
IJMP
Antimagnets: Controlling magnetic fields with superconductor-metamaterial hybrids
Magnetism is very important in science and technology, from magnetic
recording to energy generation to trapping cold atoms. Physicists have managed
to master magnetism - to create and manipulate magnetic fields- almost at will.
Surprisingly, there is at least one property which until now has been elusive:
how to 'switch off' the magnetic interaction of a magnetic material with
existing magnetic fields without modifying them. Here we introduce the
antimagnet, a design to conceal the magnetic response of a given volume from
its exterior, without altering the external magnetic fields, somehow analogous
to the recent theoretical proposals for cloaking electromagnetic waves with
metamaterials. However, different from these devices requiring extreme material
properties, our device is feasible and needs only two kinds of available
materials: superconductors and isotropic magnetic materials. Antimagnets may
have applications in magnetic-based medical techniques such as MRI or in
reducing the magnetic signature of vessels or planes.Comment: 14 pages, 4 figure
Understanding Relative Feed Value (RFV) and Relative Forage Quality (RFQ)
Feed quality of alfalfa harvested as haylage or hay depends, to a great extent, on the maturity of the stand. With increasing maturity, plant structural carbohydrates, as measured by the ADF and NDF fractions, increase. These fiber fractions represent the more indigestible parts of the plant. As a result, digestibility and energy obtained through fermentation decrease with maturity. Relative feed value (RFV) has been used for years to compare the quality of legume and legume/grass hays and silages. Having one index to price hay and predict animal performance has been very useful for livestock producers and hay farmers
RFV vs. RFQ -- Which is Better?
Determining the value of hay is often times a trying adventure but the rewards can be significant. It begs the question though, what do those numbers really tell me? Do they provide me pertinent information? There are so many numbers…which ones do I need to be concerned with? All of the numbers and information on the results sheets are important. However, certain numbers have greater bearing on some classes of livestock than others. As research continues to give us new parameters regarding, herd health, pounds of gain, pounds of milk, maintenance, etc. the importance of these will also likely change as well
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