65 research outputs found
The effect of feed ingredients on feed manufacturing and growth performance of pigs
Doctor of PhilosophyDepartment of Animal Sciences and IndustryRobert D. GoodbandTwo experiments evaluated effects of glycerol on pellet mill production and pig performance. In Exp. 1, increasing glycerol increased (quadratic; P 0.01) production energy (kWh/t). In Exp. 2, pigs were fed one of seven diets with no added soy oil or glycerol (control); the control diet with 3 or 6% added soy oil, 3 or 6% added glycerol, and 6 or 12% additions of a 50:50 soy oil/glycerol blend in a 26-d growth assay. Adding glycerol improved (P < 0.01) pellet durability compared to soy oil and the soy oil/glycerol blend treatments. Pigs fed glycerol had increased (linear, P < 0.03) ADG. Adding soy oil, glycerol, or the soy oil/glycerol blend resulted in similar final BW. Two experiments evaluated the effects of glycerol as a replacement for lactose on pellet mill production and nursery pig performance. In Exp. 1, pigs were fed one of ten treatments that included 0, 3.6, or 7.2% lactose or 0, 3.6, or 7.2 % glycerol and fed in either meal or pelleted form. Pellet durability index increased (linear; P < 0.01) with added lactose and glycerol. Glycerol decreased (linear; P < 0.01) production energy (kWh/t). There was a tendency (P < 0.06) for an inclusion level × diet form (meal or pellet) interaction observed for ADG. Pigs fed the pelleted diets containing the 7.2% glycerol inclusion had decreased ADG compared to all other treatments. In Exp. 2, pigs were fed one of fourteen diets that included 0, 3.6, 7.2, or 10.8% lactose or 0, 3.6, 7.2, or 10.8 % glycerol and fed in either meal or pelleted form. There was no effect (P < 0.27) of diet form, inclusion level, or source on ADG or ADFI. Eight experiments evaluated the effect of ingredients on the flow ability of ground corn. Flow ability of feed improved with added glycerol, especially when added to meal diets containing hammer mill ground corn. Specialty protein ingredients in powder form reduce flow ability, while fine lactose sources improved flow ability. Granulated ingredients improved flow ability
Changes in electric-field noise due to thermal transformation of a surface ion trap
We aim to illuminate how the microscopic properties of a metal surface map to
its electric-field noise characteristics. In our system, prolonged heat
treatments of a metal film can induce a rise in the magnitude of the
electric-field noise generated by the surface of that film. We refer to this
heat-induced rise in noise magnitude as a thermal transformation. The
underlying physics of this thermal transformation process is explored through a
series of heating, milling, and electron treatments performed on a single
surface ion trap. Between these treatments, Ca ions trapped 70
m above the surface of the metal are used as detectors to monitor the
electric-field noise at frequencies close to 1 MHz. An Auger spectrometer is
used to track changes in the composition of the contaminated metal surface.
With these tools we investigate contaminant deposition, chemical reactions, and
atomic restructuring as possible drivers of thermal transformations. The data
suggest that the observed thermal transformations can be explained by atomic
restructuring at the trap surface. We hypothesize that a rise in local atomic
order increases surface electric-field noise in this system
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
Two Massive Jupiters in Eccentric Orbits from the TESS Full-frame Images
We report the discovery of two short-period massive giant planets from NASA's Transiting Exoplanet Survey Satellite (TESS). Both systems, TOI-558 (TIC 207110080) and TOI-559 (TIC 209459275), were identified from the 30 minute cadence full-frame images and confirmed using ground-based photometric and spectroscopic followup observations from TESS's follow-up observing program working group. We find that TOI-558 b, which transits an F-dwarf (M-* =1.349(-0.065)(+0.064) M-circle dot, R-* =1.496(-0.040)(+0.042) R-circle dot, T-eff = 6466(-93)(+95) K, age 1.79(-0.73)(+0.91) Gyr) with an orbital period of 14.574 days, has a mass of 3.61 +/- 0.15 M-J, a radius of 1.086(-0.038)(+0.041) R-J, and an eccentric (e = 0.300(-0.020)(+0.022)) orbit. TOI-559 b transits a G dwarf (M-* = 1.026 +/- 0.057 M-circle dot, R-* =1.233(-0.026)(+0.028) R-circle dot, T-eff = 5925(-76)(+85) K, age 6.8(-2.0)(+2.5) Gyr) in an eccentric (e = 0.151 +/- 0.011) 6.984 days orbit with a mass of 6.01(-0.23)(+0.24) M-J and a radius of 1.091(-0.025+)(0.028) R-J. Our spectroscopic follow up also reveals a long-term radial velocity trend for TOI-559, indicating a long-period companion. The statistically significant orbital eccentricity measured for each system suggests that these planets migrated to their current location through dynamical interactions. Interestingly, both planets are also massive (>3 M-J), adding to the population of massive giant planets identified by TESS. Prompted by these new detections of high-mass planets, we analyzed the known mass distribution of hot and warm Jupiters but find no significant evidence for multiple populations. TESS should provide a near magnitude-limited sample of transiting hot Jupiters, allowing for future detailed population studies
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High temperature studies of electric-field noise in a surface ion trap
Electric-field noise is a major limiting factor in the performance of ion traps and other quantum devices. Despite intensive research over the past decade, the nature and cause of electric field noise near surfaces is not well understood. This dissertation reports the high- temperature dependence of electric-field noise above an Al-Cu surface using a trapped 40Ca+ ion as a probe.We employ a novel setup with a surface ion trap mounted on a heater for studies of the temperature dependence of electric-field noise. To characterize the Al-Cu material, we explore the effects of heat treatment through ex situ annealing followed by inspection in a scanning electron microscope. To calibrate the temperature of the trap, we demonstrate the use of thermal imaging for monitoring the temperature of an ion trap in vacuum.The temperature and frequency dependence of electric-field noise above the surface is measured using the heating rate of a single ion in a surface-electrode Paul trap. We find that the heating rate saturates at temperatures greater than 450 K. We find that the frequency dependence shows a 1/f behavior, and has a lower frequency scaling exponent at high temperatures than at room temperature. We show that these results are a reflection of the surface-related noise by eliminating other possible sources of noise.Building on historical data for resistance fluctuations in thin films, we develop the thermally-activated fluctuator model to describe the results. We find that a broad distribution of fluctuators with energy barriers peaked around 0.5 eV accurately models both the temperature and frequency dependence of the electric-field noise measured. We present the interpretation of this model as a way to infer that the cause of electric-field noise in the trap is likely defect motion in the metal surface, connecting the problems faced in ion trapping to a large body of work in solid state physics
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