50,621 research outputs found
Effects of forage supplements on milk production and chemical properties, in vivo digestibility, rumen fermentation and N excretion in dairy cows offered red clover silage and corn silage or dry ground corn
peer-reviewedThis study concerned the effects of partial substitution of clover silage with high starch forages on milk production and chemical composition, in vivo digestibility, rumen
fermentation pattern and nitrogen excretion of dairy cows. Sixteen dairy cows were
separated into two groups and were assigned to treatments in a two-period crossover
design. Two forage supplements were used: corn silage (CS) and dry ground corn (DG).
All animals received 4.5 kg of concentrate dry matter per day. Results showed no significant
difference between the forage supplements for milk production, while significant
differences (P<0.01) were observed for milk fat, milk protein and nitrogen utilisation
efficiency (42 v. 4.0 g/kg, 3.5 v. 3.3 g/kg and 222 v. 188 g/kg, respectively, for DG and CS).
Faecal N excretion did not differ between forage supplements, but urinary N excretion
was higher for CS (P<0.05). No significant differences were observed between treatments
for rumen fluid pH or for rumen fluid concentrations of ammonium nitrogen
or of acetic, propionic or butyric acids. Dry matter intake and the in vivo digestibility
of dry matter, organic matter, acid detergent fibre and neutral detergent fibre were all
higher for CS compared with DG.The authors are grateful to the Environmental Office
of the Cantabrian Government for funding the project
05-640.02-2174
Experimental study of optimal measurements for quantum state tomography
Quantum tomography is a critically important tool to evaluate quantum
hardware, making it essential to develop optimized measurement strategies that
are both accurate and efficient. We compare a variety of strategies using
nearly pure test states. Those that are informationally complete for all states
are found to be accurate and reliable even in the presence of errors in the
measurements themselves, while those designed to be complete only for pure
states are far more efficient but highly sensitive to such errors. Our results
highlight the unavoidable tradeoffs inherent to quantum tomography.Comment: 5 pages, 3 figure
Minkowski-type and Alexandrov-type theorems for polyhedral herissons
Classical H.Minkowski theorems on existence and uniqueness of convex
polyhedra with prescribed directions and areas of faces as well as the
well-known generalization of H.Minkowski uniqueness theorem due to
A.D.Alexandrov are extended to a class of nonconvex polyhedra which are called
polyhedral herissons and may be described as polyhedra with injective spherical
image.Comment: 19 pages, 8 figures, LaTeX 2.0
Dimensional analysis and Rutherford Scattering
Dimensional analysis, and in particular the Buckingham theorem is
widely used in fluid mechanics. In this article we obtain an expression for the
impact parameter from Buckingham's theorem and we compare our result with
Rutherford's original discovery found in the early twentieth century
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