Computerized analytical technique for design and analysis of a Sabatier reactor subsystem Final engineering report

Mathematical model for computerized evaluation of Sabatier reaction kinetics in oxygen recovery from carbon dioxid

Temperature-dependent dynamical nuclear polarization bistabilities in double quantum dots in the spin-blockade regime

The interplay of dynamical nuclear polarization (DNP) and leakage current through a double quantum dot in the spin-blockade regime is analyzed. A finite DNP is built up due to a competition between hyperfine (HF) spin-flip transitions and another inelastic escape mechanism from the triplets, which block transport. We focus on the temperature dependence of the DNP for zero energy-detuning (i.e. equal electrostatic energy of one electron in each dot and a singlet in the right dot). Our main result is the existence of a transition temperature, below which the DNP is bistable, so a hysteretic leakage current versus external magnetic field B appears. This is studied in two cases: (i) Close to the crossing of the three triplet energy levels near B=0, where spin-blockade is lifted due to the inhomogeneity of the effective magnetic field from the nuclei. (ii) At higher B-fields, where the two spin-polarized triplets simultaneously cross two different singlet energy levels. We develop simplified models leading to different transition temperatures T_TT and T_ST for the crossing of the triplet levels and the singlet-triplet level crossings, respectively. We find T_TT analytically to be given solely by the HF couplings, whereas T_ST depends on various parameters and T_ST>T_TT. The key idea behind the existence of the transition temperatures at zero energy-detuning is the suppression of energy absorption compared to emission in the inelastic HF transitions. Finally, by comparing the rate equation results with Monte Carlo simulations, we discuss the importance of having both HF interaction and another escape mechanism from the triplets to induce a finite DNP.Comment: 26 pages, 17 figure

Electron-electron interaction effects in quantum point contacts

We consider electron-electron interaction effects in quantum point contacts on the first quantization plateau, taking into account all scattering processes. We compute the low-temperature linear and nonlinear conductance, shot noise, and thermopower, by perturbation theory and a self-consistent nonperturbative method. On the conductance plateau, the low-temperature corrections are solely due to momentum-nonconserving processes that change the relative number of left- and right-moving electrons. This leads to a suppression of the conductance for increasing temperature or voltage. The size of the suppression is estimated for a realistic saddle-point potential, and is largest in the beginning of the conductance plateau. For large magnetic field, interaction effects are strongly suppressed by the Pauli principle, and hence the first spin-split conductance plateau has a much weaker interaction correction. For the nonperturbative calculations, we use a self-consistent nonequilibrium Green's function approach, which suggests that the conductance saturates at elevated temperatures. These results are consistent with many experimental observations related to the so-called 0.7 anomaly

Soybeans as a home-grown supplement for dairy cows

Soybeans, grown on the farm, give promise of providing many dairymen with a valuable protein supplement for their dairy herds which will make them independent of the purchase of high-priced protein feeds. Investigations at the Iowa Agricultural Experiment Station show that soybeans make a palatable dairy feed, that they give good results in milk production when fed in place of other protein supplements, and that pound for pound they are a third more valuable than oilmeal, with which direct comparison was made. A home-grown supplement of that kind would be especially valuable to Iowa dairy farms. These farms easily produce all of the roughages needed for the herds in both winter and summer, such as ensilage, clover, alfalfa hay and soiling crops. It is also relatively easy for them to provide the greater portion of the grain ration, as the home-grown corn and oats should form the basis of the concentrates fed. These two feeds, however, are relatively low in protein and so are the roughages, with the exception of the legume hays. It is necessary, therefore, to secure additional concentrates which will provide the extra protein needed, especially in the ration of heavy producing cows. This is one of the main problems of dairy farming today

The Pharmacopsychometric Triangle to Illustrate the Effectiveness of T-PEMF Concomitant with Antidepressants in Treatment Resistant Patients: A Double-Blind, Randomised, Sham-Controlled Trial Revisited with Focus on the Patient-Reported Outcomes

Background. Our T-PEMF trial has been revisited with focus on the pharmacopsychometric triangle in which effect size is used when comparing wanted versus unwanted clinical effects and quality of life as outcomes. In this analysis, we have especially focused on the self-reported HAM-D6. Methods. The antidepressive medication which the patients were resistant to was kept unchanged during the five weeks of active versus sham T-PEMF. Results. In total 21, patients received active T-PEMF, and 19 patients received sham T-PEMF. The effect size was 1.02 and 0.90, respectively, on HAM-D6 and HAM-D6-S. Concerning side effects, the active T-PEMF reduced the baseline score on concentration problems with an effect size of 0.44 while inducing more autonomic symptoms than sham T-PEMF with an effect size of −0.41. The advantage of active over sham T-PEMF obtained an effect size of 0.48. Conclusion. Active T-PEMF was found superior to sham T-PEMF within the pharmacopsychometric triangle with a clinically significant effect size level above 0.40

Ab initio vibrations in nonequilibrium nanowires

We review recent results on electronic and thermal transport in two different quasi one-dimensional systems: Silicon nanowires (SiNW) and atomic gold chains. For SiNW's we compute the ballistic electronic and thermal transport properties on equal footing, allowing us to make quantitative predictions for the thermoelectric properties, while for the atomic gold chains we evaluate microscopically the damping of the vibrations, due to the coupling of the chain atoms to the modes in the bulk contacts. Both approaches are based on a combination of density-functional theory, and nonequilibrium Green's functions.Comment: 16 pages, to appear in Progress in Nonequilibrium Green's Functions IV (PNGF4), Eds. M. Bonitz and K. Baltzer, Glasgow, August 200

Secretoneurin Is an Endogenous Calcium/Calmodulin-Dependent Protein Kinase II Inhibitor That Attenuates Ca2+-Dependent Arrhythmia

BACKGROUND: Circulating SN (secretoneurin) concentrations are increased in patients with myocardial dysfunction and predict poor outcome. Because SN inhibits CaMKII delta (Ca2+/calmodulin-dependent protein kinase II delta) activity, we hypothesized that upregulation of SN in patients protects against cardiomyocyte mechanisms of arrhythmia. METHODS: Circulating levels of SN and other biomarkers were assessed in patients with catecholaminergic polymorphic ventricular tachycardia (CPVT; n=8) and in resuscitated patients after ventricular arrhythmia-induced cardiac arrest (n=155). In vivo effects of SN were investigated in CPVT mice (RyR2 [ryanodine receptor 2]-R2474S) using adeno-associated virus-9-induced overexpression. Interactions between SN and CaMKII delta were mapped using pull-down experiments, mutagenesis, ELISA, and structural homology modeling. Ex vivo actions were tested in Langendorff hearts and effects on Ca2+ homeostasis examined by fluorescence (fluo-4) and patchclamp recordings in isolated cardiomyocytes. RESULTS: SN levels were elevated in patients with CPVT and following ventricular arrhythmia-induced cardiac arrest. In contrast to NT-proBNP (N-terminal proB- type natriuretic peptide) and hs-TnT (high-sensitivity troponin T), circulating SN levels declined after resuscitation, as the risk of a new arrhythmia waned. Myocardial pro-SN expression was also increased in CPVT mice, and further adeno-associated virus-9-induced overexpression of SN attenuated arrhythmic induction during stress testing with isoproterenol. Mechanistic studies mapped SN binding to the substrate binding site in the catalytic region of CaMKII delta. Accordingly, SN attenuated isoproterenol induced autophosphorylation of Thr287-CaMKII delta in Langendorff hearts and inhibited CaMKII delta-dependent RyR phosphorylation. In line with CaMKII delta and RyR inhibition, SN treatment decreased Ca2+ spark frequency and dimensions in cardiomyocytes during isoproterenol challenge, and reduced the incidence of Ca2+ waves, delayed afterdepolarizations, and spontaneous action potentials. SN treatment also lowered the incidence of early afterdepolarizations during isoproterenol; an effect paralleled by reduced magnitude of L-type Ca2+ current. CONCLUSIONS: SN production is upregulated in conditions with cardiomyocyte Ca2+ dysregulation and offers compensatory protection against cardiomyocyte mechanisms of arrhythmia, which may underlie its putative use as a biomarker in at-risk patients.Peer reviewe

Responses of a wetland ecosystem to the controlled introduction of invasive fish

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136368/1/fwb12900_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136368/2/fwb12900.pd