Thermodynamic Analysis of a Novel Cycle for Nuclear SMR and Heat Transfer Performance Validation of the Related Supercritical Working Fluids

Currently, all operating nuclear power facilities in the U.S. follow the same general design and process: light-water reactors boil water into steam using bundles of nuclear fuel rods as a heat source, pumping that steam through a turbine which powers a generator to produce clean year-round electricity. Water is an effective coolant, but other facilities around the world have demonstrated the ability to use non-water-based coolants in nuclear reactor designs, which consequently have their own trade-offs. Some positive consequences of using different reactor designs include enhanced safety, better economics, and cheaper clean consumer energy. The work described in this paper begins with a computer model of a nuclear reactor design that uses non-water-based coolants, both pure fluids and mixtures, and measures the performance based on a few metrics. While the model did not show that the selected mixtures worked well as coolants, some of the pure fluids did lead to reactor performance at least as good as the water-based counterpart. This motivated a physical experiment that was built to better document and understand the ability for these pure fluids to transfer heat under specific conditions. These conditions include different fluid phases such as liquid or gas, and even supercritical liquids or gases which exist at higher pressures and temperatures. The boundary between supercritical phases are less clear and the distinction between them are less definite if measured by their physical properties. The experimental setup was validated to accurately capture and measure the desired heat transfer behaviors for selected fluids. The design is also future-proofed by utilizing modularity of components and by fabricating new components for testing corrosive/reactive fluids

KELT-3b: A Hot Jupiter Transiting a V = 9.8 Late-F Star

We report the discovery of KELT-3b, a moderately inflated transiting hot Jupiter with a mass of 1.477^(+0.066)_(-0.067) M_J, radius of 1.345 ± 0.072 R J, and an orbital period of 2.7033904 ± 0.000010 days. The host star, KELT-3, is a V = 9.8 late F star with M* = 1.278^(+0.063)_(-0.061) M⊙, R* = 1.472^(+0.065)_(-0.067) R⊙, T_(eff) = 6306^(+50)_(-49) K, log(g) = 4.209^(+0.033)_(-0.031), and [Fe/H] = 0.044^(+0.080)_(-0.082), and has a likely proper motion companion. KELT-3b is the third transiting exoplanet discovered by the KELT survey, and is orbiting one of the 20 brightest known transiting planet host stars, making it a promising candidate for detailed characterization studies. Although we infer that KELT-3 is significantly evolved, a preliminary analysis of the stellar and orbital evolution of the system suggests that the planet has likely always received a level of incident flux above the empirically identified threshold for radius inflation suggested by Demory & Seager

Quantum walks in weak electric fields and Bloch oscillations

Bloch oscillations appear when an electric field is superimposed on a quantum particle that evolves on a lattice with a tight-binding Hamiltonian (TBH), i.e., evolves via what we will call an electric TBH; this phenomenon will be referred to as TBH Bloch oscillations. A similar phenomenon is known to show up in so-called electric discrete-time quantum walks (DQWs); this phenomenon will be referred to as DQW Bloch oscillations. This similarity is particularly salient when the electric field of the DQW is weak. For a wide, i.e., spatially extended initial condition, one numerically observes semi-classical oscillations, i.e., oscillations of a localized particle, both for the electric TBH and the electric DQW. More precisely: The numerical simulations strongly suggest that the semi-classical DQW Bloch oscillations correspond to two counter-propagating semi-classical TBH Bloch oscillations. In this work it is shown that, under certain assumptions, the solution of the electric DQW for a weak electric field and a wide initial condition is well approximated by the superposition of two continuous-time expressions, which are counter-propagating solutions of an electric TBH whose hopping amplitude is the cosine of the arbitrary coin-operator mixing angle. In contrast, if one wishes the continuous-time approximation to hold for spatially localized initial conditions, one needs at least the DQW to be lazy, as suggested by numerical simulations and by the fact that this has been proven in the case of a vanishing electric field.Comment: 13 pages, 8 figure

Open Source Software Problems in Heat Transfer to Explore Assumptions and Models

Energy2D software can be downloaded here: http://energy.concord.org/energy2d/ After opening the application, choose File -\u3e Open and select one of the .e2d files available for download here under additional files. Click the Run button to get started. The main download has a document that provides a detailed description of the adaptation of a freely available software program, Energy2D, for problems focused on the exploration and limitations of assumptions made in models commonly used in an undergraduate heat transfer course. The motivation for creating homework problems that use Energy2D is to explore the accuracy and limitations of the models used in heat transfer. The models are commonly utilized because they are easy to use and accurate even when not entirely valid, so these problems will provide students with a better understanding of their accuracy and of when they break down. Examples of models that are used here include 1D steady conduction with no generation, assuming a uniform base surface temperature or uniform convection coefficient for extended surfaces, using shape factors for 2D steady conduction, and the lumped capacitance method for transient conduction. Additional problems were in the process of being developed and will be continually developed during the Spring 2021 semester. The remainder of the document will be organized by problem in order of their coverage in MAE 3440 Heat Transfer at Utah State University

Allogeneic CAR-T cells: more than ease of access?

Patient derived anti-CD19 chimeric antigen receptor-T (CAR-T) cells are a powerful tool in achieving a complete remission in a range of B-cell malignancies, most notably B-acute lymphoblastic leukaemia (B-ALL) and diffuse large B-cell lymphoma (DLBCL). However, there are limitations, including inability to manufacture CAR-T cells from the patient’s own T cells, disease progression and death prior to return of engineered cells. T cell dysfunction is known to occur in cancer patients, and several groups have recently described differences in CAR-T cells generated from chronic lymphocytic leukaemia (CLL) patients compared with those from a healthy donor. This is thought to contribute to the low response rate in this disease group. Healthy donor, gene-edited CAR-T cells which do not require human leucocyte antigen (HLA) matching have the potential to provide an ‘off the shelf’ product, overcoming the manufacturing difficulties of producing CAR-T cells for each individual patient. They may also provide a more functional, potent product for malignancies such as CLL, where T cell dysfunction is common and frequently cannot be fully reversed during the manufacturing process. Here we review the potential benefits and obstacles for healthy donor, allogeneic CAR-T cells

KELT-11b: A Highly Inflated Sub-Saturn Exoplanet Transiting the V = 8 Subgiant HD 93396

We report the discovery of a transiting exoplanet, KELT-11b, orbiting the bright (V = 8.0) subgiant HD 93396. A global analysis of the system shows that the host star is an evolved subgiant star with T_(eff) = 5370±51 K, M∗ = 1.438^(+0.061)_(−0.052) M⊙, R∗ = 2.72^(+0.21)_(−0.17) R⊙, log g∗= 3.727^(+0.040)_(−0.046), and [Fe/H]= 0.180 ± 0.075. The planet is a low-mass gas giant in a P = 4.736529 ± 0.00006 day orbit, with M_P = 0.195 ± 0.018 M_J, R_P = 1.37^(+0.15)_(−0.12) R_J, ρ_P = 0.093^(+0.028)_(−0.024) g cm^(−3) , surface gravity log g_P = 2.407^(+0.080)_(−0.086), and equilibrium temperature T_(eq) = 1712^(+51)_(−46) K. KELT-11 is the brightest known transiting exoplanet host in the southern hemisphere by more than a magnitude, and is the 6th brightest transit host to date. The planet is one of the most inflated planets known, with an exceptionally large atmospheric scale height (2763 km), and an associated size of the expected atmospheric transmission signal of 5.6%. These attributes make the KELT-11 system a valuable target for follow-up and atmospheric characterization, and it promises to become one of the benchmark systems for the study of inflated exoplanets

KELT-11b: A Highly Inflated Sub-Saturn Exoplanet Transiting the V = 8 Subgiant HD 93396

We report the discovery of a transiting exoplanet, KELT-11b, orbiting the bright (V = 8.0) subgiant HD 93396. A global analysis of the system shows that the host star is an evolved subgiant star with T_(eff) = 5370±51 K, M∗ = 1.438^(+0.061)_(−0.052) M⊙, R∗ = 2.72^(+0.21)_(−0.17) R⊙, log g∗= 3.727^(+0.040)_(−0.046), and [Fe/H]= 0.180 ± 0.075. The planet is a low-mass gas giant in a P = 4.736529 ± 0.00006 day orbit, with M_P = 0.195 ± 0.018 M_J, R_P = 1.37^(+0.15)_(−0.12) R_J, ρ_P = 0.093^(+0.028)_(−0.024) g cm^(−3) , surface gravity log g_P = 2.407^(+0.080)_(−0.086), and equilibrium temperature T_(eq) = 1712^(+51)_(−46) K. KELT-11 is the brightest known transiting exoplanet host in the southern hemisphere by more than a magnitude, and is the 6th brightest transit host to date. The planet is one of the most inflated planets known, with an exceptionally large atmospheric scale height (2763 km), and an associated size of the expected atmospheric transmission signal of 5.6%. These attributes make the KELT-11 system a valuable target for follow-up and atmospheric characterization, and it promises to become one of the benchmark systems for the study of inflated exoplanets

Beta cell death by cell-free DNA and outcome after clinical islet transplantation

Background: Optimizing engraftment and early survival after clinical islet transplantation is critical to long-term function, but there are no reliable, quantifiable measures to assess beta cell death. Circulating cell free DNA (cfDNA) derived from beta cells has been identified as a novel biomarker to detect cell loss, and was recently validated in new-onset type 1 diabetes and in islet transplant patients. Methods: Herein we report beta cell cfDNA measurements after allotransplantation in 37 subjects and the correlation with clinical outcomes. Results: A distinctive peak of cfDNA was observed 1hr after transplantation in 31/37 (83.8%) of subjects. The presence and magnitude of this signal did not correlate with transplant outcome. The 1hr signal represents dead beta cells carried over into the recipient after islet isolation and culture, combined with acute cell death post infusion. Beta cell cfDNA was also detected 24hrs post-transplant (8/37 subjects, 21.6%). This signal was associated with higher 1-month insulin requirements (p=0.04), lower 1-month stimulated C-peptide levels (p=0.01) and overall worse 3-month engraftment, by insulin independence (ROC:AUC=0.70, p=0.03) and Beta 2 score (ROC:AUC=0.77, p=0.006). Conclusions: cfDNA-based estimation of beta cell death 24hrs after islet allotransplantation correlates with clinical outcome and could predict early engraftment.B.G.-L. is supported through the Alberta Innovates :Health Solutions (AIHS) Clinician Fellowship and through the CNTRP. A.P. is supported through AIHS Postgraduate Fellowship and CNTRP. A.M.J.S. is supported through AIHS, and holds a Canada Research Chair in Transplantation Surgery and Regenerative Medicine funded through the Government of Canada. A.M.J.S. is also funded by AIHS Collaborative Research and Innovation Opportunity Team Award and the Diabetes Research Institute Foundation of Canada (DRIFCan). Supported by grants from the Juvenile Diabetes Research Foundation (JDRF) (3-SRA-2014-38-Q-R, to Y.D. and A.M.J.S.), National Institute of Health (NIH) (HIRN grant UC4 DK104216, to Y.D.), DON foundation (Stichting Diabetes Onderzoek Nederland) (to Y.D), the European Union (ELASTISLET project, to Y.D.) and the Kahn foundation (to Y.D., R.S., and B.G.). Supported in part by a grant from The United States Agency for International Development (USAID) American Schools and Hospitals Abroad Program for the upgrading of the Hebrew University sequencing core facilit