Many precision devices, especially measuring devices, must maintain their technical parameters in variable ambient conditions, particularly at varying temperatures. Examples of such devices may be super precise balances that must keep stability and accuracy of the readings in varying ambient temperatures. Due to that fact, there is a problem of measuring the impact of temperature changes, mainly on geometrical dimensions of fundamental constructional elements of these devices. In the paper a new system for measuring micro-displacements of chosen points of a constructional element of balance with a resolution of single nanometres and accuracy at a level of fractions of micrometres has been proposed.

This contribution aims at presenting the arguments produced by Arabic grammarians in the discussion on the ẓarf. By providing different viewpoints, the paper addresses various aspects of the issue, focusing in particular on its definition(s) and features, as well as its collocation within the overall Arabic grammatical system.

The article presents a comprehensive economic analysis of a CO2 injection project in one of the Polish oil fields for both increased production (CO2-EOR) and underground storage (CCS). An interesting differentiator of this work is the use of a multilayered reservoir, which is actually not one reservoir but several located in the same place, as an example. It allows the optimization of the processes of injection, production and storage. Such projects are becoming more and more important because recently, after a period of long-term stagnation, costs of carbon allowances have started to rise which affects e.g. the electricity market in Poland. This can be an important incentive for the development of CCS technology, especially in combination with CO2-EOR. In the case of very high costs of carbon emissions rights CCS may turn out to be a cheaper solution. Economic efficiency is the main determinant of the EOR project’s success, as well as a very significant factor influencing the potential development of CO2 underground storage. Results are based on the numerical simulation of a combined CO2-EOR and CCS project. This analysis has been divided into two parts. The first uses a standard, deterministic approach, based on the DCF method and NPV indicator. It also provides a detailed sensitivity analysis, with particular reference to the impact of oil prices and the cost of carbon emissions rights on a project’s profitability. The second part of the economic analysis is probabilistic and involves estimating the maximum amount of CAPEX using the Monte Carlo method. Two cases were taken into account. The first assumes that the CO2 emitter pays for CO2 storage and the price is equal to 80% of the emissions rights price (with storage revenue). In the second one the emitter does not pay for storage (without storage revenue).

This study presents an examination of the transmission properties of multilayered partitions made up of multiple micro-perforated plates (MPPs) coupled to acoustic enclosures with general impedance boundaries. Multi-layered MPPs can lower the transmission while minimizing reflection in the source and receiving enclosure. Previous research has mainly focused on the double MPPs or triple MPPs partition itself. However, it is vital to analyze the in-situ sound transmission loss of the multi-layered MPP and their efficiency in a complex vibro-acoustic environment. The case when the multilayered MPPs are coupled to a receiving enclosure or coupled to both a source and receiving enclosure is investigated. The objective is to provide an analytical method to evaluate the transmission properties of multilayered MPPs coupled to acoustic enclosures while being computationally more efficient than the finite element method (FEM). Using the modified Fourier series for the acoustic pressure, a variational form for the acoustic and structure medium yields a completely coupled vibroacoustic system. A comparison between the sound transmission loss of the double MPPs, when mounted on an impedance tube and coupled to acoustics enclosures, shows the modal effect of the enclosures. The effect of enclosure shape, impedance boundary, perforation ratio, air gap thickness on the sound transmission properties of the double MPPs structure is examined for both cases. Finally, in both situations, the performance of triple MPP structure insulation is evaluated.