Magnetic resonance imaging analysis of moving fronts in floating dosage forms

An application of magnetic resonance imaging in the field of pharmaceutical technology is presented in this paper. The analysis of diffusion and swelling fronts was carried out for four floating dosage forms using magnetic resonance imaging. The influence of polymer viscosity, its concentration, and type of applied dissolution media on the area of moving fronts was investigated

Computer simulation study of high-pressure gas quenching of a steel element within vacuum furnace batch for different working conditions

Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.The paper presents analysis of the high-pressure gas quenching of metal elements, after their vacuum carbonisation process, based on the computer simulation. The ANSYS-CFX code has been used for this purpose. This transient quenching process includes challenging problems, which requires deep knowledge and application of heat transfer, fluid mechanics and thermodynamics. The numerical simulation analysis method focuses on a single element contained in an elementary, repeatable section (usually a cuboid) of the whole batch. In this study quenching of a steel cylinder of diameter d = 20mm and length L = 150 mm is analysed. This approach allows defining precisely: (i) the geometries of the metal element and of the elementary cubical section associated with it and, also, (ii) flow and thermal boundary conditions on the walls of this elementary section. Above definition of the elementary section (a computing domain) allows using the whole available computing power for the quenching process simulation in it. The ratio of volumes mentioned in (i) defines a “porosity of batch” and the analysis covers the range from 7 to 70%. The number of grid points used for the elementary section varies from 55000 to 240000. The influence of the pressure gradient value (a flow “driving force” through the elementary section) and its direction – on temperature and quenching rate time distributions in a steel element – is analysed and presented. The use of periodicity and symmetry conditions, for the velocity field, on the elementary section walls, allows simulating different single element quenching conditions – reflecting its position in the batch. The transient quenching has been usually analysed for a fixed velocity field. However, the steel element body thermal properties in this transient process varied – appropriately to its time dependent temperature distribution. The initial element temperature is assumed to be equal 1300 K. The influence of different gases, i.e. argon, helium, nitrogen and hydrogen, and their static pressures (up to 30 bar), on the steel element quenching process, is analysed and presented.cs201

Impact of European Integration on the Functioning of the Insurance Market in Poland

The transformation process, that has begun 20 years ago, generated significant changes in the structure and organization of Polish economy. It stimulated development of particular market's segments, especially of the insurance sector. Poland's accession to the European Union required conformity to Its regulations, fulfillment of several conditions connected with the membership in the European Community. The purpose of this article is to present the main consequences of Poland's integration with EU in the field of insurance market. Joining the common market was an important challenge for this sector in our country.Rok 1990 stanowił początek procesu transformacji systemu społeczno - gospodarczego i ustrojowego. Ostatnie 20 lat to okres intensywnych przemian o charakterze strukturalnym i organizacyjnym, w wyniku których ukształtowały się warunki rozwoju poszczególnych segmentów systemu finansowego państwa, zwłaszcza sektora ubezpieczeń. Przystąpienie Polski do Unii Europejskiej wymagało wprowadzenia szeregu zmian, dostosowujących polski porządek prawny do uregulowań wspólnotowych regulujących funkcjonowanie rynku ubezpieczeń. Celem artykułu jest zaprezentowanie szans i zagrożeń, jakie wynikają dla tego segmentu gospodarki z przystąpienia Polski do UE. Niewątpliwie proces integracji stanowił poważne wyzwanie dla polskiego rynku ubezpieczeń

Optimal operation of an integrated hybrid renewable energy system with demand-side management in a rural context

A significant portion of the Indian population lives in villages, some of which are located in grid-disconnected remote areas. The supply of electricity to these villages is not feasible or cost-effective, but an autonomous integrated hybrid renewable energy system (IHRES) could be a viable alternative. Hence, this study proposed using available renewable energy resources in the study area to provide electricity and freshwater access for five un-electrified grid-disconnected villages in the Odisha state of India. This study concentrated on three different kinds of battery technologies such as lithium-ion (Li-Ion), nickel-iron (Ni-Fe), and lead-acid (LA) along with a diesel generator to maintain an uninterrupted power supply. Six different configurations with two dispatch strategies such as load following (LF) and cycle charging (CC) were modelled using nine metaheuristic algorithms to achieve an optimally configured IHRES in the MATLAB (c) environment. Initially, these six configurations with LF and CC strategies were evaluated with the load demands of a low-efficiency appliance usage-based scenario, i.e., without demand-side management (DSM). Later, the optimal configuration obtained from the low-efficiency appliance usage-based scenario was further evaluated with LF and CC strategies using the load demands of medium and high-efficiency appliance usage-based scenarios, i.e., with DSM. The results showed that the Ni-Fe battery-based IHRES with LF strategy using the high-efficiency appliance usage-based scenario had a lower life cycle cost of USD 522,945 as compared to other battery-based IHRESs with LF and CC strategies, as well as other efficiency-based scenarios. As compared to the other algorithms used in the study, the suggested Salp Swarm Algorithm demonstrated its fast convergence and robustness effectiveness in determining the global best optimum values. Finally, the sensitivity analysis was performed for the proposed configuration using variable input parameters such as biomass collection rate, interest rate, and diesel prices. The interest rate fluctuations were found to have a substantial impact on the system's performance.Web of Science1514art. no. 517

Regioisomeric and substituent effects upon the outcome of the reaction of 1-borodienes with nitrosoarene compounds

A study of the reactivity of 1-borodienes with nitrosoarene compounds has been carried out showing an outcome that differs according to the hybridization state of the boron moiety. Using an sp2 boron substituent, a one-pot hetero-Diels–Alder/ring contraction cascade occurred to afford N-arylpyrroles with low to good yields depending on the electronic properties of the substituents on the borodiene, whereas an sp3 boron substituent led to the formation of stable boro-oxazines with high regioselectivity in most of the cases, in moderate to good yields. 1H and 11B NMR studies on two boro-oxazine regioisomers showed that selective deprotection can be performed. Formation of either the pyrrole or the furan derivative is pH- and regioisomer-structure-dependent. The results obtained, together with previous B3LYP calculations, support mechanistic proposals which suggest that pyrrole, or furan, formation proceeds via oxazine formation, followed by a boryl rearrangement and an intramolecular addition–elimination sequence