1,101 research outputs found
Symmetry relations in chemical kinetics arising from microscopic reversibility
It is shown that the kinetics of time-reversible chemical reactions having
the same equilibrium constant but different initial conditions are closely
related to one another by a directly measurable symmetry relation analogous to
chemical detailed balance. In contrast to detailed balance, however, this
relation does not require knowledge of the elementary steps that underlie the
reaction, and remains valid in regimes where the concept of rate constants is
ill-defined, such as at very short times and in the presence of low activation
barriers. Numerical simulations of a model of isomerization in solution are
provided to illustrate the symmetry under such conditions, and potential
applications in protein folding-unfolding are pointed out.Comment: 4 pages, 1 figure, accepted to Phys Rev Let
Entropy and density of states from isoenergetic nonequilibrium processes
Two identities in statistical mechanics involving entropy differences (or
ratios of density of states) at constant energy are derived. The first provides
a nontrivial extension of the Jarzynski equality to the microcanonical ensemble
[C. Jarzynski, Phys. Rev. Lett. 78, 2690 (1997)], which can be seen as a
``fast-switching'' version of the adiabatic switching method for computing
entropies [M. Watanabe, W. P. Reinhardt, Phys. Rev. Lett. 65, 3301 (1990)]. The
second is a thermodynamic integration formula analogous to a well-known
expression for free energies, and follows after taking the quasistatic limit of
the first. Both identities can be conveniently used in conjunction with a
scaling relation (herein derived) that allows one to extrapolate measurements
taken at a single energy to a wide range of energy values. Practical aspects of
these identities in the context of numerical simulations are discussed.Comment: 5 pages, no figure
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
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
Peran Manajemen Sumber Daya Insani: Kajian di Baznas Ponorogo
This study examines the management pattern and Human Resource utilization in Baznaz Ponorogo. The goal is to find out how far the principles of HR management are implemented in the agency. The result of the study shows that the pattern of management and human resources utilization in Baznas Ponorogo covers all aspects, from the recruitment process, placement, until the evaluation of employee performance. In every stage of the process, Baznas Ponorogo not only relies on the principle of professionalism but also considers personal integrity and spiritual maturity aspects. Such is done based on the consideration that a job, if done professionally and sincerely, will yield ina higher value and quality
Comparing the effects of acupressure at LI4 and BL32 points on intramuscular injection pain
Introduction
The effectiveness of some acupressure techniques in relieving the acute pain of intramuscular injection pain has been assessed in previous studies. However, the effects of acupressure at LI4 point have still remained unknown. The aim of this study was to compare the effects of acupressure at LI4 and BL32 points on intramuscular injection pain.
Methods
This after-only interventional study was made on 90 women were who referred to the injection unit of the Central Emergency Department, Kashan, Iran, in 2015 for receiving an intramuscular injection of penicillin. The women were randomly allocated to three 30-person groups, namely control, LI4 acupressure, and BL32 acupressure groups. After intramuscular injection of penicillin, the level of intramuscular injection pain of all women was assessed by using a 0–10 visual analog scale. Data were analyzed through doing the Kruskal–Wallis, the Chi-square, and the Fisher's exact tests, and Spearman correlation coefficient.
Results
The means of pain intensity in the control, LI4 acupressure, and BL32 acupressure groups were 2.76 ± 1.75, 2.33 ± 1.80, and 1.76 ± 2.45, respectively. In other words, the mean pain intensity in the control group was significantly higher than the LI4 and BL32 acupressure groups by 0.43 and 1.0 points, respectively (p = 0.011). Except for educational status, intramuscular injection pain was not significantly correlated with the participants’ other demographic characteristics as well as injection time.
Conclusion
Acupressure can significantly relieve intramuscular injection pain. This simple, cost-effective, and easily applicable therapy can be used in all healthcare settings for relieving intramuscular injection pain
Optimized free energies from bidirectional single-molecule force spectroscopy
An optimized method for estimating path-ensemble averages using data from
processes driven in opposite directions is presented. Based on this estimator,
bidirectional expressions for reconstructing free energies and potentials of
mean force from single-molecule force spectroscopy - valid for biasing
potentials of arbitrary stiffness - are developed. Numerical simulations on a
model potential indicate that these methods perform better than unidirectional
strategies.Comment: 4 pages, 2 figure
Islamic Branding and Social Media: Implications on Stay Decisions in Sharia Hotel (Survey on Guest Staying at Noor Hotel: Moeslim Boutique Hotel Bandung)
Public awareness of Moslem-friendly tourism is increasing but it has not been followed by supporting facilities such as places of worship, halal food and beverages, also sharia hotel. On the other hand, the growth of moslem tourist visiting in 2014 was 30% to 40% higher than the growth of conventional tourists who come to Indonesia but had not been matched by the availability of adequate sharia hotels. This research uses primary data through online questionnaire distribution on one of social media platforms called instagram. The population in this research are the guests who stay in Noor Hotel Bandung with samples of 100 respondents with purposive sampling technique. The method used in this reasearch is descriptive verivicative with multiple linear regression test equipment. The results show that Islamic branding is in the highest category and social media is in medium category. While on multiple regression test, islamic branding and social media have a significant positive effect to the decision to stay at Noor Hotel. R square value of 0.492 or 49.2% means that the decision to stay at Noor Hotel is influenced by Islamic Branding and social media by 49%, while the rest 51% is influenced by other factors not examined by the author.
Keywords: Sharia Hotel, Islamic Branding, Social Media, Stay Decision, Noor Hotel
- …