Cooling jug physics

We discuss the physics of the pot-in-pot cooler. By balancing temperature decrease due to evaporation and temperature increase due to heat exchange, we find the equilibrium temperature of the pot. In this simplified model, the cooling jug acts as a psychrometer, and the theoretical prediction of our model is in a good agreement with psychrometric tables. Next, we study dynamics of the jug cooling. The cooling rate is limited by water vapour diffusion through air, heat conduction through air, and heat conduction through the body of the jug. The derived rate of temperature decrease is in general agreement with the result of our experiment. In the end, we discuss some additional factors, such as capillary effects in the raw clay, water viscosity in the capillaries, and impact of complex shape of the jug.Comment: 10 page

Кулонова сума та кулонова енергія ядра 7Lі

У дисертації наведені результати дослідження кулонової суми та кулонової енергії ядра 7Li на основі даних інклюзивного розсіяння електронів у широкому діапазоні початкових енергій Е0 та кутів розсіяння θ. У цих дослідженнях були здобуті значення поздовжньої функції відгуку RL(qc,ω) та кулонової суми SL(q) ядра 7Li у діапазоні постійних значень переданих імпульсів qc від 0.750 до 1.625 фм-1. Використовуючи ці значення SL(q), а також здобуті оцінки цієї величини при q = 0.55 фм-1 та 0.65 фм-1, з високою точністю була визначена повна кулонова енергія ядра 7Li, яка дорівнює Ecoul = (1.928 ± 0.038 ± 0.026) МеВ, де перша похибка статистична, а друга – систематична. Для того, щоб здобути з високою точністю експериментальні результати було розроблено низку методичних підходів. Проведений аналіз експериментальних значень кулонової суми довів, що залеж-ність SL(q) має високу чутливість до степеня кластеризації ядра. Порівняння кулонової енергії ядра 7Li з кулоновими енергіями ядер 6Li та 4Не – узгоджується з раніше спостережуваними в експерименті з пружного розсіян-ня електронів на ядрах 6Li та 7Li відношенням 1/2(7Li)/1/2(6Li) = 0.948 ±0.008; – приводить до висновку, що, в рамках двокластерної моделі ядра 7Li (α + t), ефективний лінійний розмір α-кластера більший за розмір вільного ядра 4Не. Експериментальні значення RL(qc,ω), SL(q) та Ecoul ядра 7Li здобуті вперше.Timchenko I.S. Coulomb sum and Coulomb energy of the 7Li nucleus. – Manuscript. Thesis for the candidate degree of physical and mathematical sciences by specialty 01.04.16 – Physics of Nucleus, Elementary Particles and High Energies. – Institute of high-energy physics and nuclear physics National Science Centre "Kharkov Institute of Physics and Technology", National Academy of Sciences of Ukraine; V. N. Karazin Kharkov National University, Ministry of Education and Science of Ukraine, Kharkov, 2019. In the thesis, a study of the Coulomb sum and the Coulomb energy of the 7Li nucleus based on inclusive electron scattering data is presented. As a result of this study, values of the longitudinal response function RL(qc,ω) and the Coulomb sum SL(q) for the 7Li nucleus for the constant momentum transfer qc ranging from 0.750 to 1.625 fm-1 were obtained. Using these values of SL(q) and the estimated ones found at q = 0.55 fm-1 and 0.65 fm-1, Ecoul = (1.928 ± 0.038 ± 0.026) MeV was derived for the total Coulomb energy. A number of methodological developments were made to reach a high accuracy of the experimental results. The analysis of the experimental Coulomb sum values has shown that the dependence SL(q) has a high sensitivity to the degree of clustering of the nuclei. The result of the comparison of the Coulomb energy for 7Li nucleus with the Coulomb energies for the 6Li and 4He nuclei – is consistent with the ratio 1/2(7Li)/1/2(6Li) = 0.948 ±0.008 (observed earlier in the experiment on the elastic electron scattering off the 7Li and 6Li nuclei); – leads to the conclusion that, within the two-cluster model of the 7Li nucleus (α + t), the effective linear size of the α-cluster should be larger than the one of the 4He nucleus. The experimental values of RL(qc,ω), SL(q) and Ecoul for the 7Li nucleus were obtained for the first time

Ontology-Based Model of Representation of Knowledge about Language Mappings

The paper presents a short review of some systems for program transformations performed on the basis of the internal intermediate representations of these programs. Many systems try to support several languages of representation of the source texts of programs and solve the task of their translation into the internal representation. This task is still a challenge as it is effort-consuming. To reduce the effort, different systems of translator construction, ready compilers with ready grammars of outside designers are used. Though this approach saves the effort, it has its drawbacks and constraints. The paper presents the general idea of using the mapping approach to solve the task within the framework of program transformations and overcome the disadvantages of the existing systems. The paper demonstrates a fragment of the ontology model of high-level languages mappings onto the single representation and gives the example of how the description of (a fragment) a particular mapping is represented in accordance with the ontology model

Formation of political culture of students-medicians in practical classes on the history of homeland

В данной статье рассмотрена внедряемая на практических занятиях по истории среди студентов медицинского вуза практика проведения политических информаций; раскрывается методика и обозначаются сложности, связанные с данной формой повышения политической культуры студенчества.This article discussed the implemented on a practical training on the history among medical students practice for political information; discloses methods and designated the difficulties associated with this form of raising students' political culture

Applicatin of R-functions Theory to Nonlinear Vibration Problems of Laminated Shallow Shells with Cutouts

In present work an effective method to research geometrically nonlinear free vibrations of elements of thinwalled constructions that can be modeled as laminated shallow shells with complex planform is applied. The proposed method is based on joint use of R-functions theory, variational methods and Bubnov-Galerkin procedure. It allows reducing an initial nonlinear system of motion equations of a shallow shell to the Cauchy problem. The mathematical formulation of the problem is performed in a framework of the refined first-order theory. The appropriate software is created within POLE-RL program system for polynomial results and using C+ + programs for splines. New problems of linear and nonlinear vibrations of laminated shallow shells with cutouts are solved. To confirm reliability of the obtained results their comparison with the ones obtained using spline-approximation and known in literature is provided. Effect o f boundary condition on cutout is studied

Application of the Variational-Structural Method to Investigate the Elasto-Plastic Bending of Thin Shells and Plates

The effective method basing on theory of R-functions and variational structural method is developedfor solving non-linear boundary problems. Elastic-plastic bending of thin shallow shells is considered. The problems are reduced to finding stationary points of suggested mixed variational functionals according to the initial linearization due to usage of subsequent loading and Newton-Kantorovich jointly with method of varying elastic parameters. The method is used for automatic calculations in «POLE» programming system for investigations of shell structural elements. The numerical justification of the method is given. New laws of nonlinear deformation of shallow shells and plates with complex shapes in plane are established