INGRES: a computer code for the rate of air ingress into an HTGR following a design-basis depressurization accident

The computer program INGRES was written to calculate the rate of air ingress into the prestressed concrete reactor vessel after a design-basis depressurization accident in a high-temperature gas-cooled reactor. The model includes the free convection loop that can occur in a cold-leg break, the expansion and contraction air exchange mechanisms, and the conversion of oxygen to carbon monoxide. Results are presented for the 2000-MW(t) Summit Power Station and the 3000-MW(t) Fulton Generating Station and are compared to computational results provided by the General Atomic Company. The results agree reasonably well even though some differences exist in the two models. (auth

A novel MELCOR modeling approach for BWR applications

Even though improvements in modeling the phenomena that occur in the lower plenum have been made, the MELCOR user must decide on the physical events that are to be modeled and create the corresponding input. In addition to the standard modeling techniques, the flexibility of MELCOR allows for nontraditional modeling as well. For typical BWR applications, the user establishes concentric radial rings for the COR Package. In theory, each ring should be composed of a channel (within the channel box walls) and a bypass (the volume region outside the channel box walls) with each region containing both fluid and structures. However, in MELCOR 1.8.3 and earlier versions, the COR Package allows particulate debris to relocate only inside the channel box walls, using a volume equivalent to the channel and bypass fluid volumes. The consequences of this modeling approach with respect to the combined channel and bypass volumes produces two anomalies in the BWR calculation, particularly for boildown sequences. The first is that the CVH Package will calculate inaccurate channel and bypass water levels for the core region, which can significantly affect predicted metal-water reaction rates. The other is that lack of separation of the channel and bypass volumes will cause an artificially large flow area through the core plate, which can lead to inaccurately determined core plate failure times and unrealistic pressure transients in the lower plenum. In an effort to mitigate the consequences of the current COR package treatment of BWR channel and bypass volumes, an atypical way of modeling the core region by doubling the number of rings so that each ring represents only a channel or bypass region has been developed and has been shown to be beneficial

A gluten reduction is the patients’ choice for a dietary ‘bottom up’ approach in IBS—a comment on “a 5Ad dietary protocol for functional bowel disorders” nutrients 2019, 11, 1938

We read the article by Ibrahim and Stribling [...

Generation of two-mode nonclassical states and a quantum phase gate operation in trapped ion cavity QED

We propose a scheme to generate nonclassical states of a quantum system, which is composed of the one-dimensional trapped ion motion and a single cavity field mode. We show that two-mode SU(2) Schr\"odinger-cat states, entangled coherent states, two-mode squeezed vacuum states and their superposition can be generated. If the vibration mode and the cavity mode are used to represent separately a qubit, a quantum phase gate can be implemented.Comment: to appear in PR

Longitudinal development of initial, chronic and mucoid Pseudomonas aeruginosa infection in young children with cystic fibrosis

BACKGROUND: While the emergence of chronic and mucoid Pseudomonas aeruginosa (Pa) infection are both associated with poorer outcomes among CF patients, their relationship is poorly understood. We examined the longitudinal relationship of incident, chronic and mucoid Pa in a contemporary, young CF cohort in the current era of Pa eradication therapy. METHODS: This retrospective cohort was comprised of patients in the U.S. CF Foundation Patient Registry born 2006-2015, diagnosed before age 2, and with at least 3 respiratory cultures annually. Incidence and age-specific prevalence of Pa infection stages (initial and chronic [≥ 3Pa+cultures in prior year]) and of mucoid Pa were summarized. Transition times and the interaction between Pa stage and acquisition of mucoid Pa were examined via Cox models. RESULTS: Among the 5592 CF patients in the cohort followed to a mean age of 5.5years, 64% (n=3580) acquired Pa. Of those, 13% (n=455) developed chronic Pa and 17% (n=594) cultured mucoid Pa. Among those with mucoid Pa, 36% (211/594) had it on their first recorded Pa+culture, while mucoid Pa emerged at or after entering the chronic stage in 12% (73/594). Mucoidy was associated with significantly increased risk of transition to chronic Pa infection (HR=2.59, 95% CI 2.11, 3.19). CONCLUSIONS: Two-thirds of early-diagnosed young children with CF acquired Pa during a median 5.6years of follow up, among whom 13% developed chronic Pa and 17% acquired mucoid Pa. Contrary to our hypothesis, 87% of young children who developed mucoid Pa did so before becoming chronically infected

A solution for galactic disks with Yukawian gravitational potential

We present a new solution for the rotation curves of galactic disks with gravitational potential of the Yukawa type. We follow the technique employed by Toomre in 1963 in the study of galactic disks in the Newtonian theory. This new solution allows an easy comparison between the Newtonian solution and the Yukawian one. Therefore, constraints on the parameters of theories of gravitation can be imposed, which in the weak field limit reduce to Yukawian potentials. We then apply our formulae to the study of rotation curves for a zero-thickness exponential disk and compare it with the Newtonian case studied by Freeman in 1970. As an application of the mathematical tool developed here, we show that in any theory of gravity with a massive graviton (this means a gravitational potential of the Yukawa type), a strong limit can be imposed on the mass (m_g) of this particle. For example, in order to obtain a galactic disk with a scale length of b ~ 10 kpc, we should have a massive graviton of m_g << 10^{-59} g. This result is much more restrictive than those inferred from solar system observations.Comment: 7 pages; 1 eps figure; to appear in General Relativity and Gravitatio

Constant Curvature Coefficients and Exact Solutions in Fractional Gravity and Geometric Mechanics

We study fractional configurations in gravity theories and Lagrange mechanics. The approach is based on Caputo fractional derivative which gives zero for actions on constants. We elaborate fractional geometric models of physical interactions and we formulate a method of nonholonomic deformations to other types of fractional derivatives. The main result of this paper consists in a proof that for corresponding classes of nonholonomic distributions a large class of physical theories are modelled as nonholonomic manifolds with constant matrix curvature. This allows us to encode the fractional dynamics of interactions and constraints into the geometry of curve flows and solitonic hierarchies.Comment: latex2e, 11pt, 27 pages, the variant accepted to CEJP; added and up-dated reference

Online Makespan Minimization with Parallel Schedules

In online makespan minimization a sequence of jobs $\sigma = J_1,..., J_n$ has to be scheduled on $m$ identical parallel machines so as to minimize the maximum completion time of any job. We investigate the problem with an essentially new model of resource augmentation. Here, an online algorithm is allowed to build several schedules in parallel while processing $\sigma$. At the end of the scheduling process the best schedule is selected. This model can be viewed as providing an online algorithm with extra space, which is invested to maintain multiple solutions. The setting is of particular interest in parallel processing environments where each processor can maintain a single or a small set of solutions. We develop a (4/3+\eps)-competitive algorithm, for any 0<\eps\leq 1, that uses a number of 1/\eps^{O(\log (1/\eps))} schedules. We also give a (1+\eps)-competitive algorithm, for any 0<\eps\leq 1, that builds a polynomial number of (m/\eps)^{O(\log (1/\eps) / \eps)} schedules. This value depends on $m$ but is independent of the input $\sigma$. The performance guarantees are nearly best possible. We show that any algorithm that achieves a competitiveness smaller than 4/3 must construct $\Omega(m)$ schedules. Our algorithms make use of novel guessing schemes that (1) predict the optimum makespan of a job sequence $\sigma$ to within a factor of 1+\eps and (2) guess the job processing times and their frequencies in $\sigma$. In (2) we have to sparsify the universe of all guesses so as to reduce the number of schedules to a constant. The competitive ratios achieved using parallel schedules are considerably smaller than those in the standard problem without resource augmentation

Generation of arbitrary two dimensional motional state of a trapped ion

We present a scheme to generate an arbitrary two-dimensional quantum state of motion of a trapped ion. This proposal is based on a sequence of laser pulses, which are tuned appropriately to control transitions on the sidebands of two modes of vibration. Not more than $(M+1)(N+1)$ laser pulses are needed to generate a pure state with upper phonon number $M$ and $N$ in the $x$ and $y$ direction respectively.Comment: to appear in PR

Evaluation of the Charm maximum residue limit beta-lactam and tetracycline test for the detection of antibiotics in ewe and goat milk

The Charm maximum residue limit P-lactam and tetracycline test (Charm MRL BLTET; Charm Sciences Inc., Lawrence, MA) is an immunoreceptor assay utilizing Rapid. One-Step Assay lateral flow technology that detects P-lactam or tetracycline drugs in raw commingled cow milk at or below European Union maximum residue levels (EU-MRL). The Charm MRL BLTET test procedure was recently modified (dilution in buffer and longer incubation) by the manufacturers to be used with raw ewe and goat milk. To assess the Charm MRL BLTET test for the detection of beta-lactams and tetracyclines in milk of small ruminants, an evaluation study was performed at Instituto de Ciencia y Tecnologia Animal of Universitat Politecnica de Valencia (Spain). The test specificity and detection capability (CC beta) were studied following Commission Decision 2002/657/EC. Specificity results obtained in this study were optimal for individual milk free of antimicrobials from ewes (99.2% for beta-lactams and 100% for tetracyclines) and goats (97.9% for beta-lactams and 100% for tetracyclines) along the entire lactation period regardless of whether the results were visually or instrumentally interpreted. Moreover, no positive results were obtained when a relatively high concentration of different substances belonging to antimicrobial families other than beta-lactams and tetracyclines were present in ewe and goat milk. For both types of milk, the CC beta calculated was lower or equal to EU-MRL for amoxicillin (4 mu g/kg), ampicillin (4 mu g/kg), benzylpenicillin (30 mu g/kg). The CC beta for tetracyclines was also lower than EU-MRL for chlortetracycline (ewe milk: <= 50 mu g/kg; goat milk: 75 mu g/kg), oxytetracycline (<= 50 mu g/kg), and tetracycline (<= 50 mu g/kg). Regarding the 4-epimers of these tetracyclines only 4-epioxytetracycline was detected by the Charm MRL BLTET test below EU-MRL (ewe milk: 75 mu g/kg; goat milk: <= 50 mu g/kg). Acidiol had no effect on the performance of the test. The Charm MRL BLTET test could be used routinely with adapted test procedure for the fast screening of ewe and goat milk.This work forms part of the Project AGL2009-11524 financed by the Ministerio de Ciencia e Innovacion (Madrid, Spain). The authors are grateful to Fatro S.p.A. (Bologna, Italy) and ACS Dobfar S.p.A. (Milan, Italy) for kindly providing cefacetrile and desacetylcefapirin, respectively. Moreover, the authors thank Charm Sciences, Inc. (Lawrence, MA) and especially Wilbert Kokke from Charm Sciences Inc. and Raul Gomez from Grupo Taper, S.A. (Madrid, Spain) for their support.Beltrán Martínez, MC.; Romero Rueda, T.; Althaus, RL.; Molina Pons, MP. (2013). Evaluation of the Charm maximum residue limit beta-lactam and tetracycline test for the detection of antibiotics in ewe and goat milk. Journal of Dairy Science. 96(5):2737-2745. https://doi.org/10.3168/jds.2012-6044S2737274596