Jarzynski Equality for an Energy-Controlled System

The Jarzynski equality (JE) is known as an exact identity for nonequillibrium systems. The JE was originally formulated for isolated and isothermal systems, while Adib reported an JE extended to an isoenergetic process. In this paper, we extend the JE to an energy-controlled system. We make it possible to control the instantaneous value of the energy arbitrarily in a nonequilibrium process. Under our extension, the new JE is more practical and useful to calculate the number of states and the entropy than the isoenergetic one. We also show application of our JE to a kind of optimization problems.Comment: 6 pages, 1 figur

Effect of Achillea millefolium Distillate on Recovery Time in Patients with Gastroenteritis

Background: Some animal studies have reported that Achillea millefolium (A. millefolium) extract can affect intestinal movements in rats. However, no study is available on the effect of A. millefolium on recovery from gastroenteritis in human subjects. Objectives: This study aimed to investigate the effect of A. millefolium on recovery from gastroenteritis in patients over 12 years old. Patients and Methods: A randomized controlled trial was conducted on 44 patients with gastroenteritis. The patients were randomly assigned to two groups of 22 each. The control group received the usual treatments. In addition to the usual treatments, the intervention group received 0.5 mL/kg of A. millefolium distillate every 8 hours. The duration of recovery was recorded for both groups. Descriptive statistics, Chi-square, Fisher’s exact test, and the t-test were used to compare the two groups. Results: The mean duration of recovery in the group receiving A. millefolium distillate was 1.31 ± 0.71 days, while it was 1.86 ± 0.71 days in the control group (P = 0.015). Conclusions: Adding A. millefolium distillate to the usual treatment for simple gastroenteritis was effective in shortening the recovery time

Path integral analysis of Jarzynski's equality: Analytical results

We apply path integrals to study nonequilibrium work theorems in the context of Brownian dynamics, deriving in particular the equations of motion governing the most typical and most dominant trajectories. For the analytically soluble cases of a moving harmonic potential and a harmonic oscillator with time-dependent natural frequency, we find such trajectories, evaluate the work-weighted propagators, and validate Jarzynski's equality.Comment: 10 pages, 1 figur

Does the Boltzmann principle need a dynamical correction?

In an attempt to derive thermodynamics from classical mechanics, an approximate expression for the equilibrium temperature of a finite system has been derived [M. Bianucci, R. Mannella, B. J. West, and P. Grigolini, Phys. Rev. E 51, 3002 (1995)] which differs from the one that follows from the Boltzmann principle S = k log (Omega(E)) via the thermodynamic relation 1/T= dS/dE by additional terms of "dynamical" character, which are argued to correct and generalize the Boltzmann principle for small systems (here Omega(E) is the area of the constant-energy surface). In the present work, the underlying definition of temperature in the Fokker-Planck formalism of Bianucci et al. is investigated and shown to coincide with an approximate form of the equipartition temperature. Its exact form, however, is strictly related to the "volume" entropy S = k log (Phi(E)) via the thermodynamic relation above for systems of any number of degrees of freedom (Phi(E) is the phase space volume enclosed by the constant-energy surface). This observation explains and clarifies the numerical results of Bianucci et al. and shows that a dynamical correction for either the temperature or the entropy is unnecessary, at least within the class of systems considered by those authors. Explicit analytical and numerical results for a particle coupled to a small chain (N~10) of quartic oscillators are also provided to further illustrate these facts.Comment: REVTeX 4, 10 pages, 2 figures. Accepted to J. Stat. Phy

Effects of a Multimodal Preparation Package on Vital Signs of Patients Waiting for Coronary Angiography

Background: Patients waiting for coronary angiography are often anxious and worried, experiencing considerable emotional problems before the procedure, which can result in an increase in blood pressure (BP), heart rate, respiratory rate and the myocardial oxygen demand. Such maladaptive responses may not only increase the patients need for sedative drugs, but also could increase the length of post angiography hospitalization. Therefore, it is important to implement some supportive actions to decrease the patients’ anxiety and to stabilize their vital signs before coronary angiography. Objectives: This study aimed to investigate the effects of a multimodal preparation package on vital signs of patients undergoing coronary angiography. Patients and Methods: A matched trial was conducted on 66 patients waiting for coronary angiography. Patients were assigned in intervention (n = 33) and control (n = 33) groups. A multimodal preparation package was implemented in intervention group, two hours before angiography. The data collection instrument consisted of questions on demographic characteristics and a table for recording the patients’ vital signs including systolic BP (SBP) and diastolic BP (DBP), heart rate, respiratory rate and body temperature. Vital signs were measured three times, the day before angiography, 30 minutes before and 30 minutes after the angiography, using a thermometer and a monitoring device. Data analysis was performed using the Kolmogo-Smirnov test, t test and Mann-Whitney U test. Results: From the total number of 66 patients, the 63.3% were male and married. No significant differences were observed between the mean of SBP and DBP and also the heart rate in the intervention and control groups, on the day before angiography. However, the mean SBP and DBP and heart rate of the intervention group were significantly lower compared to the control group, both 30 minutes before and 30 minutes after angiography. The intervention did not significantly change the respiration rate and temperature in the intervention group. Conclusions: The study showed that preparation package was effective in decreasing SBP and DBP, as well as heart rate. Therefore, using multimodal comprehensive preparation packages, such as the package used in the present report, is suggested

NP-hardness of the cluster minimization problem revisited

The computational complexity of the "cluster minimization problem" is revisited [L. T. Wille and J. Vennik, J. Phys. A 18, L419 (1985)]. It is argued that the original NP-hardness proof does not apply to pairwise potentials of physical interest, such as those that depend on the geometric distance between the particles. A geometric analog of the original problem is formulated, and a new proof for such potentials is provided by polynomial time transformation from the independent set problem for unit disk graphs. Limitations of this formulation are pointed out, and new subproblems that bear more direct consequences to the numerical study of clusters are suggested.Comment: 8 pages, 2 figures, accepted to J. Phys. A: Math. and Ge

The Effects of Massage Therapy by the Patients Relative on Vital Signs of Males Admitted in Critical Care Unit

Background: Changes in vital signs may affect the myocardial oxygen demand. Massage therapy has been used in intensive care units to relive patients’ physical and psychological problems. In all of the studies massaging has been done by a nurse and the patients’ family did not have any role. Objectives: The present study aimed to examine the effects of massage therapy by patient’s relative on vital signs of patients with acute coronary syndrome and acute myocardial infarction. Patients and Methods: A randomized controlled trial was conducted on 60 male patients hospitalized in coronary care units. In the intervention group, massage therapy was done by one of the patient’s male relatives on the third day of admission. The control group only received the routine care. Vital signs were recorded before and after the massage therapy session. SPSS 11.5 software was employed to analyze data using qui-square, Fischer exact test, independent t-test, paired t-test and descriptive statistics. Results: The pre intervention mean of systolic blood pressure of the intervention group were 126.36 ± 16.80 and changed to 121.70 ± 13.31 after the massage therapy session (P = 0.021). The mean pulse rate of the intervention group was 79.46 ± 10.41 and reached 69.30 ± 9.47 after the intervention (P = 0.001). The mean respiration rate of the intervention group also decreased after massage (P = 0.001). No significant changes were observed in diastolic blood pressure and temperature of the intervention group. No significant changes were observed in vital signs of the control group either. Conclusions: Massage therapy by the patients’ relative, decreased systolic blood pressure, pulse and respiration rates of patients admitted in critical care Unite (CCU). Because of the useful effects of those changes, it can be recommended that massage therapy by a member of the patient’s family be used to balance vital signs of patients admitted in CCU. This study was registered at Iranian Registry of Clinical Trials (IRCT). The registration number of the study is IRCT201112048296N

Preparation and characterization of a composite material based on a geopolymer binder and quartzite aggregates

We have developed a geopolymer material by alkaline reaction on thermally activated kaolin. Initially we characterized the geopolymer by different methods (rheology, DTA-TGA, etc.) and we mixed it with different amounts of natural sand to obtain a granular composite. The structural characterization of this material was undertaken by several techniques (XRF, XRD and microscopic observations). A rheological study was implemented to determine the influence of the aggregate rate on the setting kinetic. Three-point bending and compression tests were conducted for mechanical characterization. We also conducted microindentation tests to study the influence of quartzite rate on the hardness of the material. The results indicate that the integration of quartzite (up to 15 wt. %) did not alter the setting kinetic. We noted a small degradation of the mechanical behavior when the quartzite rate is increased; this effect is due to a higher density of microcracks. However, adding the aggregate has a beneficial effect on the hardness of the material. These attractive features make this material a plausible matrix whose reinforcement with plant fibers will provide a ternary composite suitable for multiple applications

Kink Dynamics in a Topological Phi^4 Lattice

It was recently proposed a novel discretization for nonlinear Klein-Gordon field theories in which the resulting lattice preserves the topological (Bogomol'nyi) lower bound on the kink energy and, as a consequence, has no Peierls-Nabarro barrier even for large spatial discretizations (h~1.0). It was then suggested that these ``topological discrete systems'' are a natural choice for the numerical study of continuum kink dynamics. Giving particular emphasis to the phi^4 theory, we numerically investigate kink-antikink scattering and breather formation in these topological lattices. Our results indicate that, even though these systems are quite accurate for studying free kinks in coarse lattices, for legitimate dynamical kink problems the accuracy is rather restricted to fine lattices (h~0.1). We suggest that this fact is related to the breaking of the Bogomol'nyi bound during the kink-antikink interaction, where the field profile loses its static property as required by the Bogomol'nyi argument. We conclude, therefore, that these lattices are not suitable for the study of more general kink dynamics, since a standard discretization is simpler and has effectively the same accuracy for such resolutions.Comment: RevTeX, 4 pages, 4 figures; Revised version, accepted to Physical Review E (Brief Reports

A survey on big data indexing strategies

The operations of the Internet have led to a significant growth and accumulation of data known as Big Data.Individuals and organizations that utilize this data, had no idea, nor were they prepared for this data explosion.Hence, the available solutions cannot meet the needs of the growing heterogeneous data in terms of processing. This results in inefficient information retrieval or search query results.The design of indexing strategies that can support this need is required. A survey on various indexing strategies and how they are utilized for solving Big Data management issues can serve as a guide for choosing the strategy best suited for a problem, and can also serve as a base for the design of more efficient indexing strategies.The aim of the study is to explore the characteristics of the indexing strategies used in Big Data manageability by covering some of the weaknesses and strengths of B-tree, R-tree, to name but a few. This paper covers some popular indexing strategies used for Big Data management. It exposes the potentials of each by carefully exploring their properties in ways that are related to problem solving