Effect of excess charge carriers and fluid medium on the magnitude and the sign of the Casimir-Lifshitz torqueP. Thiyam

Last year, we reported a perturbative theory of the Casimir-Lifshitz torque between planar biaxially anisotropic materials in the retarded limit [Phys. Rev. Lett. {\bf 120}, 131601 (2018)], which is applied here to study the change of sign and magnitude of the torque with separation distance in biaxial black phosphorus having excess charge carriers. The study is carried out both in vacuum as well as in a background fluid medium. The presence of extra charge carriers and that of an intervening fluid medium are both found to promote enhancement of the magnitude of the torque between identical slabs. The degree of enhancement of the magnitude of torque increases not only with an increased carrier concentration but also with separation distance. In the non-identical case when different planes of anisotropic black phosphorus face each other, owing to the non-monotonic characteristic of the sign-reversal effect of the torque, the enhancement by carrier addition and intervening medium also becomes non-monotonic with distance. In the presence of a background medium, the non-monotonic degree of enhancement of the torque with distance is observed even between identical slabs

Дослідження напрямів підвищення ефективності дистанційних продажів в аптеках

Aim. To audit the websites of pharmacy chains to identify the main problems and directions for improving the effectiveness of the sale of medicines using information and communication systems remotely. Materials and methods. The content analysis, desk research methods, logical summarization of results, and the graphic method were used to achieve the goal. Data from website analytics were used for the analysis. Results. Six sites of pharmacy chains in Ukraine have been analyzed. It has been found that on average one user views three pages per session, the duration of the session is one minute on average, and the buyer on average collects a basket of four products in the amount of UAH 300. It has been determined that the main login pages are: product page, product list, and main page. It has been determined that search is a key feature of product selection and is used in 15 % of all sessions. It has been found that in 70 % of cases, mobile devices are used, desktops are used in on average in 26 % of cases, and tablets are used in 4 % of cases. It has been determined that, on average, twice as many conversions are made through the desktop than when using mobile devices and tablets. For the analysis, the most common scenarios of user behavior on the pharmacy chain sites have been selected. While implementing the most frequent errors on websites have been identified, when the interface does not respond to important requests of consumers, which affects their purchase decisions. The analysis and systematization of the main errors on the websites of pharmacy chains have been carried out; recommendations for their elimination have been formulated. This will make it possible to increase the effectiveness of information support for electronic sales of pharmacies in accordance with the requirements of proper pharmacy practice, will affect the customer loyalty and the economic indicators of the activity of pharmacies. Conclusions. Based on the results of the study, it can be concluded that usability errors and factors contributing to growth should not be underestimated since they can significantly affect conversion rates; even a slight rapid change can improve the site’s KPIs; it is necessary to make the interface equally user-friendly on different devices.Мета – провести аудит сайтів аптечних мереж для виявлення основних проблем та напрямів підвищення ефективності реалізації лікарських засобів (ЛЗ) з використанням інформаційно-комунікаційних систем дистанційним способом. Матеріали та методи. Для досягнення визначеної мети було використано контент-аналіз, методи кабінетних досліджень, логічного узагальнення результатів та графічний метод. Для аналізу використано дані аналітики сайтів. Результати дослідження. Проаналізовано шість сайтів аптечних мереж України. Виявлено, що пересічно один користувач за один сеанс переглядає три сторінки, тривалість сеансу становить одну хвилину, покупець збирає кошик із чотирьох товарів на суму 300 грн. Виявлено, що основними сторінками входу є: сторінка товару, список товарів, головна сторінка. З’ясовано, що пошук є ключовим функціоналом підбору товарів і його використовують у 15 % всіх сеансів. Виявлено, що у 70 % випадків користуються мобільними пристроями, десктопом користуються пересічно у 26 % випадків, у 4 % – планшетом. З’ясовано, що через робочий стіл конверсій здійснюють вдвічі більше, ніж за використання мобільних пристроїв і планшетів. Для аналізу нами було обрано найпоширеніші сценарії поведінки користувачів на сайтах аптечних мереж. У процесі їх реалізації було визначено найчастіші помилки на сайтах, коли інтерфейс не відповідає на важливі запити споживачів, що впливає на їхнє рішення про покупку. Проаналізовано та систематизовано основні помилки на сайтах аптечних мереж, а також сформульовано рекомендації з їх усунення. Це дозволить підвищити ефективність інформаційного супроводу електронних продажів аптек відповідно до вимог належної аптечної практики, вплине на лояльність покупців і економічні показники діяльності аптек. Висновки. За результатами дослідження можна зробити висновок, що помилки юзабіліті та фактори, що сприяють зростанню, не варто недооцінювати, тому що вони істотно можуть вплинути на показники конверсії; навіть незначна швидка зміна може покращити KPI сайту; необхідно зробити інтерфейс однаково зручним для користувача на різних пристроях

Маркетинговий аналіз та позиціонування сечогінних (діуретичних) препаратів на фармацевтичному ринку України

Aim. To perform the marketing analysis of the domestic pharmaceutical market in the segment of diuretic medicines and study the directions of their positioning. Materials and methods. The research materials are data from the State Register of Medicines of Ukraine and the Electronic Medicines Compendium. To achieve the goal, the methods of logical and meaningful problem formation, desk market research, comparative analysis, content analysis of scientific and practically oriented medical and pharmaceutical publications were used. Results and discussion. The article presents the results of the marketing analysis of the domestic pharmaceutical market of diuretic medicines of group C03 “Diuretics” registered at the pharmaceutical market of Ukraine as of July 1, 2023. It has been determined that the range of diuretic medicines includes 124 trade names analyzed by INN, the number of trade names, by production, dosage form, price range, availability in the assortment of pharmacies. The analysis of the market of the group of medicines studied by producing countries, form of release and conditions of dispensing from pharmacies has been performed, as well as positioning has been carried by the peculiarities of the use of diuretics by such consumer segments as children, women during pregnancy and lactation. The INNs of medicines, which content are not offered by domestic manufacturers, have been identified, and therefore they can be considered promising for updating the product range. Conclusions. The results of the marketing analysis of the diuretic market and development of positioning directions are the basis for the search and development of new effective domestic medicines for the treatment and prevention of renal failure, neurological and cardiac diseases and other diseases in the pharmacotherapy of which diuretics are used.Мета роботи – маркетинговий аналіз вітчизняного фармацевтичного ринку в сегменті сечогінних (діуретичних) препаратів та дослідження напрямів їх позиціонування. Матеріали та методи. Матеріалами дослідження є дані Державного реєстру лікарських засобів (ЛЗ) України та онлайн довідника ЛЗ Компендіум. Для досягнення визначеної мети використано методи логіко-змістовного формування проблеми, кабінетних маркетингових досліджень, порівняльного аналізу, контент-аналізу публікацій у наукових та практично-орієнтованих медичних і фармацевтичних виданнях. Результати та їх обговорення. У статті наведено результати маркетингового аналізу вітчизняного фармацевтичного ринку сечогінних (діуретичних) препаратів групи С03 «Сечогінні препарати», зареєстрованих на фармацевтичному ринку України станом на 01.07.2023 року. З’ясовано, що асортимент сечогінних (діуретичних) препаратів нараховує 124 торгових найменування, які проаналізовано за МНН, кількістю торгівельних найменувань за виробничою ознакою, лікарською формою, діапазоном цін, наявністю в асортименті аптек. Виконано аналіз ринку досліджуваної групи ЛЗ за країнами-виробниками, формою випуску та умовами відпуску з аптечних закладів, а також проведено позиціонування за особливостями застосування діуретиків такими сегментами споживачів, як діти, жінки у період вагітності та лактації. Виявлено МНН, лікарські засоби із вмістом яких не пропонують вітчизняні виробники, і тому їх можна розглядати як перспективні для оновлення товарного асортименту. Висновки. Результати маркетингового аналізу ринку сечогінних препаратів та опрацювання напрямів позиціонування є підґрунтям для пошуку й розробки нових ефективних ЛЗ вітчизняного виробництва для лікування і профілактики ниркової недостатності, неврологічних, кардіологічних та інших захворювань, у фармакотерапії яких застосовують діуретики

Scientific and Methodological Approaches to Modeling the Optimal Strategy for Increasing the Competitiveness of Pharmacy Chains of Different Sizes

The aim of the work is to develop scientific and methodological approaches to modelling the optimal strategy to increase the competitiveness of pharmacy chains (PC), which belong to different clusters. Materials and methods. The algorithm for determining the optimal strategy for increasing the competitiveness of PC for different clusters using the method of constructing a decision tree and cluster analysis is proposed. To solve this problem, an expert survey of more than 400 pharmacy managers, who were part of the PC of different sizes, was previously conducted. According to the results of an expert survey using hierarchical clustering methods based on the values of 13 input variables - scores of the strengths of the competitiveness of the PC, three clusters of networks were identified, each of which proposed its own algorithm for modelling the optimal strategy of competitiveness. Results. Using modern economic and mathematical tools, the distribution of PC depending on their size into clusters for modelling the dynamics of competitiveness is substantiated. Indicators are identified, which show a significant difference between clusters, which was taken into account in the process of modelling and selection of the optimal strategy to increase the competitiveness of PC. It is established that the biggest negative impact on the strategy of increasing the competitiveness of small networks has a slow response to changes in market conditions, the biggest positive impact – the availability of additional services in the networks; for medium PC the most important factors influencing the level of competitiveness are the location of pharmacies and competent management; for large PC – the use of modern automated management programs, the level of efficiency of the marketing complex and location features. The algorithm of the generalized model of “decision tree” for a choice of optimum strategy of increase of competitiveness depending on the size of PC is constructed. It was found that the following factors are of the greatest importance: the size of the PC, the use of the discount card system, and the least - the speed of response to market changes and the stability of the financial condition. Conclusions. The proposed generalized mathematical model of the “decision tree” allows a reasonable approach to choosing the optimal strategy to increase the competitiveness of PC depending on its size. The assessment of the importance of predictor variables for each cluster of PC allows determining the priority factors in the implementation of measures aimed at implementing the chosen strategy to increase competitivenes

Premelting and formation of ice due to Casimir-Lifshitz interactions: Impact of improved parameterization for materials

Recently, the premelting and formation of ice due to the Casimir-Lifshitz interaction, proposed in early 1990s by Elbaum and Schick [Phys. Rev. Lett. 66, 1713 (1991)PRLTAO0031-900710.1103/PhysRevLett.66.1713], have been generalized to diverse practical scenarios, yielding novel physical intuitions and possibilities of application for those phenomena. The properties of materials, in particular, the electrical permittivity and permeability, exert significant influence on the Casimir-Lifshitz energies and forces and hence on the corresponding premelting and formation of ice. To address these influences in detail and explore the resulting physics, here we revisit and extend the analyses of previous work with both the dielectric data utilized there and the latest dielectric functions for ice and cold water. For the four-layer cases considered by some of us, the existence of stable configurations depending on the initial conditions has been confirmed, and different types of stability corresponding to minima of the Casimir-Lifshitz free energy are demonstrated. As the new dielectric functions for ice and cold water deviate considerably from those used by Elbaum and Schick, their vital impact on three- and four-layer configurations is therefore being reconsidered

Peculiarities of electrooptical characteristics of gallium phosphide light-emitting diodes in high injection level conditions

Electroluminescence of green N-doped gallium phosphide light-emitting diodes was studied. The negative differential resistance region in the current-voltage characteristics was found at low temperature (Т ≤ 90 К). Possible reason of this phenomenon is the redistribution of recombinational flows between annihilation channels on isolated nitrogen atoms and annihilation channel on the NN1 pairs

Effects of van der Waals forces and salt ions on the growth of water films on ice and the detachment of CO

We study the effect of salts on the thickness of wetting films on melting ice and interactions acting on CO2 bubble near ice-water and vapor-water interfaces. Governing mechanisms are the Lifshitz and the double-layer interactions in the respective three-layer geometries. We demonstrate that the latter depend on the Casimir-Polder interaction of the salt ions dissolved in water with the respective ice, vapor and CO2 interfaces, as calculated using different models for their effective polarizability in water. Significant variation in the predicted thickness of the equilibrium water film is observed for different salt ions and when using different models for the ions' polarizabilities. We find that CO2 bubbles are attracted towards the ice-water interface and repelled from the vapor-water interface

Dispersion forces stabilise ice coatings at certain gas hydrate interfaces which prevent water wetting

Gas hydrates formed in oceans and permafrost occur in vast quantities on Earth representing both a massive potential fuel source and a large threat in climate forecasts. They have been predicted to be important on other bodies in our solar systems such as Enceladus, a moon of Saturn. CO2-hydrates likely drive the massive gas-rich water plumes seen and sampled by the spacecraft Cassini, and the source of these hydrates is thought to be due to buoyant gas hydrate particles. Dispersion forces can in some cases cause gas hydrates at thermal equilibrium to be coated in a 3-4nm thick film of ice, or to contact water directly, depending on which gas they contain. As an example, the results are valid at a quadruple point of water-CO2 gas hydrate system, where a film is formed not only for the model with pure ice but also in the presence of impurities in water or in the ice layer. These films are shown to signicantly alter the properties of the gas hydrate clusters, for example, whether they float or sink. It is also expected to influence gas hydrate growth and gas leakage

Anisotropic contribution to the van der Waals and the Casimir-Polder energies for CO 2 and CH 4 molecules near surfaces and thin films

In order to understand why carbon dioxide (CO 2 ) and methane (CH 4 ) molecules interact differently with surfaces, we investigate the Casimir-Polder energy of a linearly polarizable CO 2 molecule and an isotropically polarizable CH 4 molecule in front of an atomically thin gold film and an amorphous silica slab. We quantitatively analyze how the anisotropy in the polarizability of the molecule influences the van der Waals contribution to the binding energy of the molecule