One and two dimensional tunnel junction arrays in weak Coulomb blockade regime-absolute accuracy in thermometry

We have investigated one and two dimensional (1D and 2D) arrays of tunnel junctions in partial Coulomb blockade regime. The absolute accuracy of the Coulomb blockade thermometer is influenced by the external impedance of the array, which is not the same in the different topologies of 1D and 2D arrays. We demonstrate, both by experiment and by theoretical calculations in simple geometries, that the 1D structures are better in this respect. Yet in both 1D and 2D, the influence of the environment can be made arbitrarily small by making the array sufficiently large.Comment: 11 pages, 3 figure

Effects of different levels of date pits in broilers’ feed contaminated with aflatoxin B1 on broilers’ performance and carcass characteristic

The aim of this study was to evaluate the ability of date pits (DP) to reduce the deleterious effects of aflatoxin B1 (AFB1) in broiler chicks. A total of 216 one-day-old male broiler chicks (Ross 308) were distributed randomly for nine treatments (with four replicates and six birds in each) for 35 days. The experiment included a 3×3 factorial arrangement of treatments involving three levels of DP (0, 2 and 4%) and three levels of AFB1 (0, 150 and 300 ppb) based on a completely randomized design. There was a significant reduction of feed intake with treatment of 300 ppb during fourth and fifth weeks. DP levels were effective in diminishing the adverse effect caused by aflatoxin on feed intake of broilers (P < 0.05). However, 4% date pits had better effect. Mean body weights were not affected weekly, but the main effect of aflatoxin was significantly (P < 0.05) low by feeding 300 ppb aflatoxin in fourth and fifth weeks. Treatments with DP levels did not show any significant change with control group in case of feed conversion ratio; however the main effect of aflatoxin diets containing 300 ppb showed significant reduction in feed conversion ratio only in fourth week (P <0.05). Carcass weight decreased significantly in the main levels of AFB1 while the relative weight of the liver, intestine, gizzard and thigh increased significantly (P ≥ 0.05). Other carcass parts were not affected. It is  suggested that DP might be used for reducing the adverse effects of aflatoxin in the broiler diets.Keywords: Aflatoxin, broiler, date pits, performance, carcass characteristicAfrican Journal of Biotechnology, Vol. 13(1), pp. 185-193, 1 January, 201

Coulomb blockade in one-dimensional arrays of high conductance tunnel junctions

Properties of one-dimensional (1D) arrays of low Ohmic tunnel junctions (i.e. junctions with resistances comparable to, or less than, the quantum resistance $R_{\rm q}\equiv h/e^2\approx 25.8$ k$\Omega$) have been studied experimentally and theoretically. Our experimental data demonstrate that -- in agreement with previous results on single- and double-junction systems -- Coulomb blockade effects survive even in the strong tunneling regime and are still clearly visible for junction resistances as low as 1 k$\Omega$. We have developed a quasiclassical theory of electron transport in junction arrays in the strong tunneling regime. Good agreement between the predictions of this theory and the experimental data has been observed. We also show that, due to both heating effects and a relatively large correction to the linear relation between the half-width of the conductance dip around zero bias voltage, $V_{1/2}$, and the measured electronic temperature, such arrays are inferior to those conventionally used in the Coulomb Blockade Thermometry (CBT). Still, the desired correction to the half-width, $\Delta V_{1/2}$, can be determined rather easily and it is proportional to the magnitude of the conductance dip around zero bias voltage, $\Delta G$. The constant of proportionality is a function of the ratio of the junction and quantum resistances, $R/R_{\rm q}$, and it is a pure strong tunneling effect.Comment: LaTeX file + five postscript figure

Thermoelectricity in Nanowires: A Generic Model

By employing a Boltzmann transport equation and using an energy and size dependent relaxation time ($\tau$) approximation (RTA), we evaluate self-consistently the thermoelectric figure-of-merit $ZT$ of a quantum wire with rectangular cross-section. The inferred $ZT$ shows abrupt enhancement in comparison to its counterparts in bulk systems. Still, the estimated $ZT$ for the representative Bi$_2$Te$_3$ nanowires and its dependence on wire parameters deviate considerably from those predicted by the existing RTA models with a constant $\tau$. In addition, we address contribution of the higher energy subbands to the transport phenomena, the effect of chemical potential tuning on $ZT$, and correlation of $ZT$ with quantum size effects (QSEs). The obtained results are of general validity for a wide class of systems and may prove useful in the ongoing development of the modern thermoelectric applications.Comment: 15 pages, 6 figures; Dedicated to the memory of Amirkhan Qezell

Berberine Improves Meat Quality and Carcass Traits in Broilers Challenged with Mycotoxins

Background and Aim: Mycotoxin-contaminated feed causes significant concern in poultry production and public health because of serious economic losses and health problems caused by them.  Berberine hydrochloride (Berberine), a natural plant alkaloid derived from Chinese medicine, is characterized by diverse pharmacological effects. This study is designed to evaluate the effects of different levels of Berberine (BBR) on carcass traits and meat quality of broilers fed diets contaminated with Aflatoxin B1 (AFB) and Ochratoxin A (OCT). Methods: A 42-day floor pen trial was performed with 288 Ross 308 broilers. A randomized design, with 4 replicates of 8 birds each, was conducted with the following 9 treatments: (1) negative control diet with no additives (NC); (2) NC + 2 ppm AFB (positive control AFB; PCAFB); (3) NC + 2 ppm OCT (positive control OCT; PCOCT); (4) PCAFB + 200 mg/kg BBR; (5) PCAFB + 400 mg/kg BBR; (6) PCAFB + 600 mg/kg BBR; (7) PCOCT + 200 mg/kg BBR; (8) PCOCT + 400 mg/kg BBR; and (9) PCOCT + 600 mg/kg BBR. At the end of the experiment, from every group, eight birds were selected, slaughtered, and subjected to analyses. The analyzed parameters carcass and cut yields and meat quality according to water-holding capacity (WHC) and breast level MDA. Results: Both PCAFB and PCOTA diets decreased carcass relative weight, breast level MDA, and WHC values compared with the NC diet (p<0.05). Meat level of MDA in PCAFB and PCOTA treatments were higher than in the NC treatment (p˂0.05), and supplementation with BBR at multiple levels partially these effects (p˂0.05). The addition of 600 mg/kg BBR to PCAFB diets increased WHC value to levels not different from that in the NC group (p>0.05). Carcass efficiency in PCAFB and PCOTA treatments was lower than in the NC treatment (p˂0.05), and supplementation with BBR at multiple levels partially or fully reversed these effects. The addition of 600 mg/kg BBR to PCAFB diet increased carcass relative weight compared to PCAFB alone (p>0.05). Conclusion: These data provided supplementation of BBR (600 mg/kg) improves meat quality in broiler fed diet contaminated with mycotoxins. *Corresponding Author: Nazar Afzali; Email: [email protected] Please cite this article as: Malekinezhad P, Afzali N, Farhangfar SH, Omidi A, Mohammadi A. Berberine Improves Meat Quality and Carcass Traits in Broilers Challenged with Mycotoxins. Arch Med Lab Sci. 2020;6:1-9 (e23). https://doi.org/10.22037/amls.v6.3333

Single-charge escape processes through a hybrid turnstile in a dissipative environment

We have investigated the static, charge-trapping properties of a hybrid superconductor---normal metal electron turnstile embedded into a high-ohmic environment. The device includes a local Cr resistor on one side of the turnstile, and a superconducting trapping island on the other side. The electron hold times, t ~ 2-20s, in our two-junction circuit are comparable with those of typical multi-junction, N >= 4, normal-metal single-electron tunneling devices. A semi-phenomenological model of the environmental activation of tunneling is applied for the analysis of the switching statistics. The experimental results are promising for electrical metrology.Comment: Submitted to New Journal of Physics 201

Arrays of Josephson junctions in an environment with vanishing impedance

The Hamiltonian operator for an unbiased array of Josephson junctions with gate voltages is constructed when only Cooper pair tunnelling and charging effects are taken into account. The supercurrent through the system and the pumped current induced by changing the gate voltages periodically are discussed with an emphasis on the inaccuracies in the Cooper pair pumping. Renormalisation of the Hamiltonian operator is used in order to reliably parametrise the effects due to inhomogeneity in the array and non-ideal gating sequences. The relatively simple model yields an explicit, testable prediction based on three experimentally motivated and determinable parameters.Comment: 13 pages, 9 figures, uses RevTeX and epsfig, Revised version, Better readability and some new result