39,128 research outputs found
Solid-state time-to-pulse-height converter developed
Solid-state circuit produces an output pulse with an amplitude directly proportional to the time interval between two input pulses. It uses selected circuit options to achieve variable mode operation and a tunnel diode controls the charging time of a capacitor in proportion to the time interval being measured
Determination of the Equation of State of Dense Matter
Nuclear collisions can compress nuclear matter to densities achieved within
neutron stars and within core-collapse supernovae. These dense states of matter
exist momentarily before expanding. We analyzed the flow of matter to extract
pressures in excess of 10^34 pascals, the highest recorded under
laboratory-controlled conditions. Using these analyses, we rule out strongly
repulsive nuclear equations of state from relativistic mean field theory and
weakly repulsive equations of state with phase transitions at densities less
than three times that of stable nuclei, but not equations of state softened at
higher densities because of a transformation to quark matter.Comment: 26 pages, 6 figures; final versio
Effect of fumaric acid, calcium formate and mineral levels in diets on the intake and growth performance of newly weaned pigs
peer-reviewedThe weaned pig has limited ability to acidify its stomach contents. The objective of this study (comprising three experiments) was to examine the effect of feeding diets
containing fumaric acid (FA), calcium formate (CF) or diets of low acid binding capacity (ABC) on post-weaning pig performance. In all three experiments, pigs (10 per treatment) were weaned at 19 to 24 days, blocked on sex and weight and assigned at random to one of six treatments. In Experiment 1, treatments were: (1) control diet, (2) control 20 g/kg FA, (3) control 15 g/kg CF, (4) low Ca (2.8 g/kg) and P (5.1 g/kg) (LCaP) diet for seven days followed by the control diet, (5) LCaP diet for seven days followed by control 20 g/kg FA, and (6) LCaP diet for seven days followed by control 15 g/kg CF. In Experiment 2, treatments were: (1) control diet, (2) control 20 g/kg FA, (3) control 15 g/kg CF, (4) LCaP diet for 14 days followed by the control diet, (5) LCaP diet for 14 days followed by control 20 g/kg FA, and (6) LCaP diet for seven days followed by control diet. In Experiment 3, treatments were: (1) high Ca (HC) diet (12 g/kg), (2) medium Ca (MC) diet (9 g/kg), (3) low Ca (LC) diet (6 g/kg), (4) HC 20 g/kg FA, (5) MC 20 g/kg FA, and (6) LC 20 g/kg FA. Pigs were individually fed for 26 days. In Experiment 1, CF tended to depress daily feed intake (DFI) in the final two weeks (691 v. 759 and 749, (s.e. 19) g/day, P = 0.07) and overall average daily gain (322 v. 343 and 361 (s.e. 11) g/day, P = 0.09) compared with the control and FA supplemented diets, respectively. Feeding diets with LCaP for seven days post
weaning increased DFI (208 v. 178, (s.e. 8) g/day, P < 0.01) in week 1 and tended to
improve feed conversion rate in the first two weeks (1.65 v. 1.85, s.e. 0.10, P = 0.09). In Experiment 2, treatment had no significant effect on pig performance but feed conversion rate in weeks three and four was improved for Treatment 5 compared with
Treatment 4 (1.30 v. 1.39 (s.e. 0.06) g/g, P < 0.01). In experiment 3, FA increased (P <
0.05) pig weight at day 14 (8.4 v. 7.7 (s.e. 0.2) kg) and feed intake in weeks one and two
(223 v. 251, (s.e. 9) g/day). It is concluded that CF did not improve performance but reducing diet ABC or including FA in the diet did improve performance
The Economic Benefits of Closing Educational Achievement Gaps: Promoting Growth and Strengthening the Nation by Improving the Educational Outcomes of Children of Color
This report quantifies the economic benefits of closing one of the most harmful racial and ethnic gaps: the educational achievement gap that exists between black and Hispanic children and native-born white children. Gaps in academic achievement are a function of a host of factors, such as income and wealth inequality, access to child care and preschool programs, nutrition, physical and emotional health, environmental factors, community and family structures,differences in the quality of instruction and school, and educational attainment. This suggests there are a wide range of public policies that could help narrow educational achievement gaps; this report demonstrates that there are enormous payoffs to closing the gaps through public policies. It also outlines effective public policy strategies to achieve this goal, though their details are left to future research. After briefly summarizing the analysis's findings, this report places the educational achievement gaps in context to help explain their significance and the reasons they exist. In particular, the report reviews data on growing inequality, demographic changes, and intensifying global economic competition. This clarifies the need to address educational achievement gaps and helps explain why the benefits of closing gaps are great. The report then describes factors that cause educational achievement gaps and offers public policies that could help close them. The subsequent sections of the report discuss the literature on the importance of academic achievement to economic growth, the methodology used in the analysis, and its detailed findings
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