Oral solid dosage forms are most frequently administered with a glass of water which empties from the stomach relatively fast, but with a certain variability in its emptying kinetics. The purpose of ...this study was thus to simulate different individual water gastric emptying (GE) patterns in an
glass-bead flow-through dissolution system. Further, the effect of GE on the dissolution of model drugs from immediate-release tablets was assessed by determining the amount of dissolved drug in the samples pumped out of the stomach compartment. Additionally, different HCl solutions were used as dissolution media to assess the effect of the variability of pH of the gastric fluid on the dissolution of three model drugs: paracetamol, diclofenac sodium, and dipyridamole. The difference in fast and slow GE kinetics resulted in different dissolution profiles of paracetamol in all studied media. For diclofenac sodium and dipyridamole tablets, the effect of GE kinetics was well observed only in media, where the solubility was not a limiting factor. Therefore, GE kinetics of co-ingested water influences the drug release from immediate-release tablets, however, in certain cases, other parameters influencing drug dissolution can partly or fully hinder the expression of this effect.
Industry 4.0 (I4.0) implies a group of technologies, organisational concepts and management principles to improve the performance of manufacturing companies or supply chains driven by production cost ...optimisation, mass customisation requirements, connectivity and digitisation of factories. The purpose of this paper is to relate Iberian Peninsula advances in I4.0 from Spanish and Portuguese research works published in CJOR papers. Hence this paper reviews the Spanish and Portuguese operations research (OR) and industrial engineering-based papers published in CJOR from 2011, when the I4.0 concept emerged, to the present-day. Here 47 papers are reviewed according to classification criteria based on the following elements: (1) objectives; (2) application context; (3) modelling approach; (4) development or software tool; (5) I4.0 technologies. The main outcomes, limitations and further research are also identified for recent papers. Finally, research trends and future directions in industrial engineering, OR and I4.0 are discussed.
The paper is based on Grubbström's MRP theory previously used in analysis of production processes "under one roof ". This theory has recently been extended to model global supply chains by Bogataj ...and Grubbström, both scientists from the MEDIFAS faculty. Every production cycle is followed by distribution, consumption and recycling activities. In broad supply chains, transportation costs between pairs of activity cells have a significant impact on the overall net present value of the system. Possible flows inside or between subsystems can all be described with input-output matrices H and G. Recently published papers of the above mentioned authors describe the presentation of supply chains in a generalized form. Generalized input and output matrices H̆(s) and Ğ(s) hold technical coefficients and lead times. Lead times are split into 2 parts: production and transportation. As presented in the publication of R. W. Grubbström, L. Bogataj and M. Bogataj, and further research of these authors, the results of recycling activities in the extended MRP model are the recovered and the waste items, but in their model the recycling of the items is not repeated.
Recovered items could be reused several times in future production cycles, reducing the need to purchase new items on the market as considered here. The waste items must be disposed of, requiring environmental taxes which vary among regions, depending on local environmental policy. If recovered, items must be delivered from the recycling facility back to production, and waste items must be sent to landfills. This process requires an expenditure of human resources, and energy at each activity cell plays an important role. In this article we show how the location of recycling facilities, the prices and quantity of energy needed and the environmental taxes can drastically influence the net present value for the entire system. We also present the method for evaluating cases where energy can be recovered during recycling or decomposition processes at landfills. It is also assumed that energy recovery can be stimulated with subsidized purchase prices, but generally, lower quality energy can be expected as an output of these processes. This paper introduces generalized input and output energy matrices, which describe these energy flows and their impact on environmental sustainability through the net present value of the system, which is the novelty in the extended MRP theory.
Ageing and shrinking of the European population influence the shrinking of central places and the hinterland of cities in a spatial structure. Migration also influences the shrinking or growing of ...spatial units. Various factors influence migration and, thus, spatial units’ demographic, social and economic stability. The age structure of citizens in a spatial unit may change not only due to population ageing but also because these factors influence the migration flows of different cohorts differently, which has not been studied so far.
We used data on internal migration between Slovenian municipalities in 2018 and 2019 to develop a cohort-based spatial interaction model to estimate future inter-municipal migration.
In a spatial interaction model, we analyzed differences in the attractiveness and stickiness of municipalities for different cohorts, focusing on those over 65 who may wish to prolong their working status. We also tried to answer the question of how to mitigate shrinkage processes in spatial units by investigating the potential to contribute to the social value of communities.
The study’s results show that the 65+ cohorts do not have the same preferences regarding the attractiveness and stickiness factors as younger migrants.
The results of our study could contribute to better decisions at the national, regional, and/or local level when designing strategies for regional, urban, and/or rural development, exploring the best solutions for long-term care, and investing in appropriate networks, or considering the revitalization of rural municipalities.
The populations of rural areas across Europe, especially Slovenia, are ageing rapidly and the areas themselves are becoming depopulated. Therefore, this study aims to contribute to our understanding ...of the population dynamics and provide a method for forecasting housing and other long-term care needs.
The surveys questioned those responsible for long-term care, the caretakers in institutional care, and current and potential homecare users in rural areas of Slovenia. We wanted to discover what they considered as crucial in the process of long-term care deinstitutionalization. Our 2020-2050 projections are based on the surveys conducted across 38 municipalities in the Eastern Slovenian region and an in-depth empirical study in Posavje. The results are embedded in the demographic projections and the multistate transition model of the declining functional capacities to forecast the needed housing facilities and human resources.
The results are the time series of required capacities. Around 60% of respondents in Slovenian rural areas believe that even a better organization of homecare would not allow them to stay at home until death due to inadequately built housing and the absence of a continuous presence of caregivers. These findings were included in the projections. Therefore, community care in the network of Smart Silver Villages was proposed.
Investments are needed to renovate the housing stock of older adults and construct sheltered, assisted living housing and specialized households in the community. Moreover, proper education and training of human resources would increase the output. In addition, financial solutions are advised to develop Smart Silver Villages.
The Material Requirements Planning (MRP) Theory celebrates 50 years of its development. Because delays are Inevitable, Grubbström developed a theory where delays are calculated in the space of ...complex variables. Using his approach to evaluate time and exposure to risk in complex production-inventory systems is much easier when dealing with multiple delays. Working in the space of complex variables, which describe production flows and cash flows associated with items, it is easier to derive the NPV of activities in the system. This approach allows for a better evaluation of the impacts on the exposure to risks and rescheduling. We presented the development of this theory since 1967 when Grubbström published his first economic article on Laplace Transforms in production and investments. We discuss possible directions for further progress towards age management, environmental sustainability and closed-loop control, risk evaluation, and
agile
rescheduling in the framework of Industry 4.0. The overview includes the canon of Grubbström's work to be used as a reference for researchers, who are aware of the importance of correct and accurate timing for the economic evaluation of technical systems. It also underlines an open question: Can this approach support the development of more transparent and resilient financial systems for financing global inventories?
One of the main factors affecting changes in internal migration is real estate taxation. In this paper, we analyse the impact of real estate taxation on internal migration flows of human resources ...between spatial units at the local level. We address the impact of changed taxation policy on the attractiveness and stickiness of Slovenian municipalities on the dynamics of migration for internal migration flows according to the annulled Real Property Tax Act. To this end, a spatial interaction model for internal migration flows was developed. In addition to the tax rate, which influences municipal revenues and the price of real estate through housing rents, we included other significant explanatory variables in our model. These include population size, distance, employment, gross personal income, municipal revenues, residential area per capita and the average price per square metre of floor space. On the basis of available data and including tax rate as a decision variable in the spatial interaction model, the impact of taxation policy on the attractiveness of municipalities of destination for migration is analysed in more detail in the case study for the Municipality of Ljubljana. Based on available data, we also analysed the changes in municipal revenue brought on by the changes in taxation of real estate in all municipalities in Slovenia for migration flows.
Due to lead times and other delays in a chain, the Net Present Value (NPV) can be easily estimated if Laplace transforms in MRP models are employed. This leads to the estimation of NPV on an infinite ...horizon. However, for the simultaneous perturbations of several parameters in a supply chain and activities running on the finite horizon, NPV could be overestimated. Therefore, we suggest the parallel use of the Network Simulation Method (NSM) with the MRP theory to reduce these overestimations. This paper aims to present the NSM to evaluate supply chains on a finite horizon when stochastic behaviour of time delays and other perturbations of parameters are also essential, which is typical for food and drug supply chains. The circuit simulator NGSPICE, which was previously used by certain authors in thermodynamics, also evaluates the financial consequences of simultaneous perturbations in a finite chain. This approach holds better for the stochastic processes of simultaneous perturbations, compared to our results achieved using MRP theory without these corrections. As presented in the numerical example, the shorter the horizon and lower the interest rate, the more important it is to use the correction factors obtained from the NGSPICE simulator.
Over 90% of seniors prefer to age in place, which is an idea supported by the European Semesters on Long-Term Care strategic plans for member states, but they do not have the necessary innovation to ...improve the living of the elderly in a properly built environment with sustainable financing. The spatial dispersion of housing and density in a functional area should be particularly taken into consideration by facilities’ managers and medical care institutions offering housing, healthcare and other services for the elderly in planning the built environment and other facilities for seniors because the costs of logistics (material transport, nurse workload, costs of other service providers, and transport of seniors in the case of daily programmes) greatly depend on it. Using data from a care centre in a Hungarian municipality, we simulated and optimised home healthcare routing and scheduling in various scenarios of spatial dispersion and changing density of clients. We modelled the rounds of caregivers visiting seniors in homecare as a multiple travelling salesman problem, and the solutions show the necessary workforce and service time requirements. The tool that enabled us to study the outputs of scenarios might help professionals forecast and plan for coming changes in the costs of nursing services caused by the growing number of seniors that may need help in maintaining their independence as long as possible, taking into account that the density and dispersion of households are also changing.
PDF
