Quantum heat engines with multiferroic working substance

The work provides an overview on some recent advances in the area of quantum thermodynamics and quantum heat engines. A particular emphasis is put on the possibility of constructing finite time quantum cycles and adiabatic shortcuts. We discuss in details the particular quantum heat engines operating with a multiferroic working substance.Comment: Lecture Notes of the 12th International School on Theoretical Physics Symmetry, Spin Dynamics and the Properties of Nanostructure

Antimicrobial effects of chlorhexidine, matrica drop mouthwash (chamomile extract), and normal saline on hospitalized patients with endotracheal tubes

Background: The functions and use of mouthwashes are variable depending on their type. Oral care in patients with endotracheal tubes is important to prevent side effects such as pneumonia. The aim of this study was to determine the antimicrobial effects of chlorhexidine, drop of Matrica mouthwash (chamomile extract), and normal saline on hospitalized patients with endotracheal tube in an intensive care unit (ICU). Materials and Methods: In this clinical trial, 39 patients admitted to the ICU were selected by convenience sampling, were matched based on age and sex, and randomly assigned to three groups (chlorhexidine, Matrica, saline). Mouth washing was performed every 8 to 48 hours. The samples were taken at time zero (before the intervention) and 48 hours after the intervention for bacterial culture. Antibacterial activity of each mouthwash on microorganisms was measured based on the growth of Staphylococcus aureus, Pneumococcal, Enterococcus, Pseudomonas, and Escherichia coli. The obtained data were then analyzed using Chi-square and Fisher's exact tests with the Statistical Package for the Social Sciences Package version 18. Results: Chlorhexidine mouthwash was more effective in preventing colonization of bacteria in the mouth (point probability = 0.06) in comparison with chamomile and saline mouthwashes. Nevertheless, none of the tested mouthwashes were able to remove pathogens, including Staphylococcus aureus, Pseudomonas, Klebsiella, and Acinetobacter. Conclusions: 0.2% chlorhexidine mouthwash has a significant effect on the bacterial colonization rate in comparison with Matrica and normal saline mouthwashes in ICU hospitalized patients with endotracheal tube

بررسی میزان انواع خشونت خانگی و عوامل مرتبط با آن در مادران باردار منطقه کلاله

یافته‌ها: 312 نفر معادل 78 درصد از مادران باردار به اشکال مختلف مورد خشونت قرار گرفته بودند. شایع‌ترین نوع خشونت علیه مادران باردار، عاطفی بود و 78 نفر از زنان از خشونت جسمی و 53 نفر از خشونت جنسی شکایت داشتند. همچنین با افزایش تحصیلات خشونت علیه مادران کاهش پیدا کرد. بین خشونت خانگی و مصرف سیگار و عدم اشتغال همسر رابطه معناداری مشاهده شد Introduction: Violence against women is a universal phenomenon which has negative impact on the mental health of the family and society, and the consequences such as increased health care costs, reduced productivity and labor force of women are another results of this health and social cultural problem. So, this study was performed with aim to determine types of domestic violence and its related factors in pregnant women. Methods: This descriptive-analytic study was performed on 368 pregnant mothers in area of Kalaleh in 2014. Data were collected by simple sampling and using a questionnaire. Data was analyzed with SPSS software (version 19) and descriptive statistics and Fisher's exact test, Chi-square, independent t-test, and Pearson correlation test. Results: 312 pregnant women (84.78%) had been exposed to different types of violence. The most common type of violence against pregnant women was emotional with 181 cases (49.18%) and 78 (21.20%) complained of physical violence and 53 (14.40%) of sexual violence. Increased education reduced violence against women. There was a significant relationship between domestic violence, smoking and lack of husband's employment (P <0.05). Conclusion: According to high rate of domestic violence, it is recommended to screen violence in the all health and therapy centers. Also, life skills training and counseling culture among couples is important

Pulse and quench induced dynamical phase transition in a chiral multiferroic spin chain

Quantum dynamics of magnetic order in a chiral multiferroic chain is studied. We consider two different scenarios: Ultrashort terahertz (THz) excitations or a sudden electric field quench. Performing analytical and numerical exact diagonalization calculations we trace the pulse induced spin dynamics and extract quantities that are relevant to quantum information processing. In particular, we analyze the dynamics of the system chirality, the von Neumann entropy, the pairwise and the many body entanglement. If the characteristic frequencies of the generated states are non-commensurate then a partial loss of pair concurrence occurs. Increasing the system size this effect becomes even more pronounced. Many particle entanglement and chirality are robust and persist in the incommensurate phase. To analyze the dynamical quantum transitions for the quenched and pulsed dynamics we combined the Weierstrass factorization technique for entire functions and Lanczos exact diagonalization method. For a small system we obtained analytical results including the rate function of Loschmidt echo. Exact numerical calculations for a system up to 40 spins confirm phase transition. Quench- induced dynamical transitions have been extensively studied recently. Here we show that related dynamical transitions can be achieved and controlled by appropriate electric field pulses.Comment: 13 pages, 10 figures, submitted in PR

Quantum Otto heat engine based on a multiferroic chain working substance

We study a quantum Otto engine operating on the basis of a helical spin-1/2 multiferroic chain with strongly coupled magnetic and ferroelectric order parameters. The presence of a finite spin chirality in the working substance enables steering of the cycle by an external electric field that couples to the electric polarization. We observe a direct connection between the chirality, the entanglement and the efficiency of the engine. An electric-field dependent threshold temperature is identified, above which the pair correlations in the system, as quantified by the thermal entanglement, diminish. In contrast to the pair correlations, the collective many-body thermal entanglement is less sensitive to the electric field, and in the high temperature limit converges to a constant value. We also discuss the correlations between the threshold temperature of the pair entanglement, the spin chirality and the minimum of the fidelities in relation to the electric and magnetic fields. The efficiency of the quantum Otto cycle shows a saturation plateau with increasing electric field amplitude.DFG/SFB/762DFG/BE 2161/5-1DFG/QUESTDFG/Graduiertenkolleg/1729DFG/SFB/TR 8

Helical multiferroics for electric field controlled quantum information processing

Magnetoelectric coupling in helical multiferroics allows us to steer spin order with electric fields. Here we show theoretically that in a helical multiferroic chain quantum information processing as well as quantum phases are highly sensitive to electric (E) field. Applying E field, the quantum state transfer fidelity can be increased and made directionally dependent. We also show that E field transforms the spin-density-wave/nematic or multipolar phases of a frustrated ferromagnetic spin-12 chain in chiral phase with a strong magnetoelectric coupling. We find sharp reorganization of the entanglement spectrum as well as a large enhancement of fidelity susceptibility at Ising quantum phase transition from nematic to chiral states driven by electric field. These findings point to a tool for quantum information with low power consumption. © 2014 American Physical Society

Nucleon-Nucleon Correlations and Two-Nucleon Currents in Exclusive (e,e′NNe,e'NN) Reactions

The contributions of short-range nucleon-nucleon (NN) correlations, various meson exchange current (MEC) terms and the influence of $\Delta$ isobar excitations (isobaric currents, IC) on exclusive two-nucleon knockout reactions induced by electron scattering are investigated. The nuclear structure functions are evaluated for nuclear matter. Realistic NN interactions derived in the framework of One-Boson-Exchange model are employed to evaluate the effects of correlations and MEC in a consistent way. The correlations correlations are determined by solving the Bethe-Goldstone equation. This yields significant contributions to the structure functions W_L and W_T of the (e,e'pn) and (e,e'pp) reactions. These contributions compete with MEC corrections originating from the $\pi$ and $\rho$ exchange terms of the same interaction. Special attention is paid to the so-called 'super parallel' kinematics at momentum transfers which can be measured e.g. at MAMI in Mainz.Comment: 14 pages, 8 figures include

Meson exchange currents in electromagnetic one-nucleon emission

The role of meson exchange currents (MEC) in electron- and photon-induced one-nucleon emission processes is studied in a nonrelativistic model including correlations and final state interactions. The nuclear current is the sum of a one-body and of a two-body part. The two-body current includes pion seagull, pion-in-flight and the isobar current contributions. Numerical results are presented for the exclusive 16O(e,e'p)15N and 16O(\gamma,p)15N reactions. MEC effects are in general rather small in (e,e'p), while in (\gamma,p) they are always large and important to obtain a consistent description of (e,e'p) and (\gamma,p) data, with the same spectroscopic factors. The calculated (\gamma,p) cross sections are sensitive to short-range correlations at high values of the recoil momentum, where MEC effects are larger and overwhelm the contribution of correlations.Comment: 9 pages, 6 figure