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

Analisis Aliran Daya Sistem Tenaga Listrik Pada Bagian Texturizing Di PT Asia Pasific Fibers Tbk Kendal Menggunakan Software ETAP Power Station 4.0

Analisis Aliran Daya Listrik (Load Flow) adalah suatu studi untuk merencanakan dan mengetahui besarnya daya dalam suatu sistem tenaga listrik. Dalam perkembangannya, industri membutuhkan tenaga listrik yang besar dan menggunakan peralatan listrik sebagai alat produksi. Manfaat dari adanya analisis aliran daya listrik adalah untuk mengetahui besarnya daya dalam sistem tenaga listrik apakah masih memenuhi batas-batas yang telah ditentukan, serta untuk mengetahui besar Losses yang ada, dan untuk memperoleh kondisi mula pada perencanaan sistem yang baru. Studi analisis aliran beban ini mengambil contoh pada implementasi sistem tenaga listrik di PT. Asia Pasific Fibers Tbk Kendal, dengan karakteristik beban terpusat (lumped load). Analisis aliran daya diawali menghitung daya aktif dan daya reaktif pada setiap simpul (bus) terpasang, pembebanan pada transformator, pembebanan pada saluran atau penghantar, nilai rugi daya (Losses), jatuh tegangan sistem, dan aliran daya pada jaringan sistem tenaga listrik terpasang. Dari hasil perhitungan aliran daya berbantuan program ETAP (Electrical Transient Analyzer Program) dapat disimpulkan bahwa sistem jaringan listrik sudah baik. Hasil yang diperoleh adalah selisih rugi daya aktif dan rugi daya reaktif pada Bus Beban 4 terlalu besar. Sedangkan jatuh tegangan masih memenuhi standar menurut hasil Text Report pada ETAP

Medication Management Skills of Nursing Students: Comparing the Students and Their Instructors' Evaluation in two Universities

Background: Nurses have critical roles in the process of medication. Evaluating the process of medication helps nursing educators and students to determine the present status and then, improve the quality of care. Objective: The current study was conducted to compare the self-evaluation of nursing students in their own medication skills with the evaluation done by clinical instructors, in Qom’s Azad University and Arak University of Medical Sciences, in 2011. Materials and Methods: A descriptive study was conducted. Data gathered using a self-report questionnaire and an observation checklist. A total of 141 students and 10 instructors participated in the study. SPSS software (version 13) was employed to analyze the data. Descriptive statistics and Wilcoxon rank test were used. Results: The mean scores for the domain of medication preparation were 2.51 ± 0.55 and 2.58 ± 0.57 based on the students’ self-evaluation and the instructors' evaluation of the students, respectively. No significant difference was observed between the total mean scores of ‘medication preparation’ in the two evaluation methods (P > 0.05). The highest mean score was achieved in the domain of drug administration both in the self-evaluation and evaluation by the instructors. A significant difference was observed between the total mean scores of ‘drug administration’ in the two evaluation methods (P < 0.05). The domain ‘post medication nursing care’ has got the lowest mean score among the three domains both from the perspective of the students and that of the instructors. The mean scores of different domains of medication management were close in the two universities. Conclusions: The present study showed that the nursing students are not quite competent in the process of medication therapy both from their own and their clinical instructors’ perspectives. This finding shows the urgent need to implement some actions to strengthen the students’ skills in medication therapy

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

Use and misuse of aspirin in rural Ethiopia

Objectives: To investigate ability to distinguish simple analgesics, to document misconceptions about aspirin use, and to identify strategies to diminish potentially harmful aspirin use in Ethiopia. Design: Qualitative study (eight focus group discussions) used to inform cross-sectional survey. Setting: Butajira, a small town in southern Ethiopia, and surrounding rural areas. Participants: Purposively selected informants for focus groups; random sample of urban and rural residents for cross-sectional survey. Main outcome measures: Ability to distinguish aspirin from paracetamol; proportion using aspirin; proportion aware of common risks of aspirin. Results: Questionnaires were completed by 204 of the 250 residents sampled (82% response). Three-quarters of survey participants knew the difference between aspirin and paracetamol. Aspirin was used by 7.3% of respondents, and was mainly taken for headache and fever. In focus group discussions there was a suggestion that aspirin was considered particularly useful for children. There was very low awareness of the risks of using aspirin in children (2.5% unprompted, 18.6% prompted) or in people with asthma (1% unprompted, 5.9% prompted). Aspirin is cheap and widely available in urban and rural areas.Conclusion: Awareness of the risks of aspirin use by children and in asthma is extremely low in this rural Ethiopian setting. Medications are purchased with minimal packaging by a population with low literacy. Drug dispensers and vendors must be trained to convey simple verbal warnings about aspirin use. East African Medical Journal Vol. 83(1) 2006: 31-3

Resonant nucleation of spatio-temporal order via parametric modal amplification

We investigate, analytically and numerically, the emergence of spatio-temporal order in nonequilibrium scalar field theories. The onset of order is triggered by destabilizing interactions (DIs), which instantaneously change the interacting potential from a single to a double-well, tunable to be either degenerate (SDW) or nondegenerate (ADW). For the SDW case, we observe the emergence of spatio-temporal coherent structures known as oscillons. We show that this emergence is initially synchronized, the result of parametric amplification of the relevant oscillon modes. We also discuss how these ordered structures act as bottlenecks for equipartition. For ADW potentials, we show how the same parametric amplification mechanism may trigger the rapid decay of a metastable state. For a range of temperatures, the decay rates associated with this resonant nucleation can be orders of magnitude larger than those computed by homogeneous nucleation, with time-scales given by a simple power law, $\tau_{\rm RN}\sim[E_b/k_BT]^B$, where $B$ depends weakly on the temperature and $E_b/k_BT$ is the free-energy barrier of a critical fluctuation.Comment: 38 pages, 20 figures now included within the tex

Tomorrow’s world: Current developments in the therapeutic use of technology for psychosis

There is now an established evidence base for the use of information and communication technology (ICT) to support mental healthcare (‘e-mental health’) for common mental health problems. Recently, there have been significant develop-ments in the therapeutic use of computers, mobile phones, gaming and virtual reality technologies for the assessment and treatment of psychosis. We provide an overview of the therapeutic use of ICT for psychosis, drawing on searches of the scientific literature and the internet and using interviews with experts in the field. We outline interventions that are already relevant to clinical practice, some that may become available in the foreseeable future and emerging challenges for their implementation

Three-Dimensional Finite Element Analysis of Tensile-Shear Spot-Welded Joints in Tensile and Compressive Loading Conditions

Three-dimensional finite element analysis is applied to verify mechanical behavior of spot welds for one, three and five spot welds under tensile and compressive loading conditions. The elastic-plastic stress distribution at edge of hot spot weld is used for strength calculations. To obtain exact and reliable results for finite element analysis of spot welds, which are generally very small relative to other dimensions, sub-modeling technique is applied. The proposed numerical calculation scheme allows one to take into account the material parameters and geometrical non-linearity effects related to a gap between thin plates, buckling, etc. We provide the analysis of elastic and elastoplastic behavior of specimens with various configuration of spot welds subjected to tensile and compressive axial loads.Выполнен трехмерный конечноэлементный анализ образцов с одним, тремя и пятью точечными сварными швами при растяжении и сжатии. Для расчета на прочность используется распределение упругопластических напряжений в корне точечного шва. Предложена методика субмоделирования, позволяющая получить более точные результаты конечноэлементного расчета точечных швов малых размеров. Схема численного расчета дает возможность учитывать параметры материала и геометрические нелинейные эффекты, обусловленные наличием зазора между тонкостенными пластинами, их выпучиванием и т.д. Проанализировано упругое и упругопластическое поведение образцов с различной конфигурацией сварных швов при нагружении растягивающими и сжимающими осевыми усилиями.Виконано тривимірний скінченноелементний аналіз зразків з одним, трьома та п’ятьма точковими зварними швами в умовах розтягу і стиску. Для розрахунку на міцність використовується розподіл пружно-пластичних напружень у корені точкового шва. Запропоновано методику субмоделювання, що дозволяє отримати більш точні результати скінченноелементного розрахунку точкових швів малих розмірів. Схема числового розрахунку дає можливість враховувати параметри матеріалу і геометричні нелінійні ефекти, зумовлені наявністю зазору між тонкостінними пластинами, їх випинанням і т.п. Проаналізовано пружну і пружно-пластичну поведінку зразків із різною конфігурацією зварних швів при навантаженні розтяжними і стискальними осьовими зусиллями