An evaluation of the posterior cruciate ligament function in total knee arthroplasty with regard to its morphology and clinical properties

The aim of the study was to determine the degree of posterior cruciate ligament (PCL) degeneration and the reduction in the number of its mechanoreceptors, in patients with advanced degenerative joint disease. PCLs taken from study group of 50 patients in the mean age of 70.7 (53–84) years with a diagnosis of advanced idiopathic osteoarthritis undergoing condylar total knee arthroplasty were compared to those taken form the control group of 10 knee joints of cadavers. Groups were matched with regard to sex and age. Histological examination of PCLs of the study group showed changes of an inflammatory process and no significant signs of osteoarthritis in the control group. A close correlation was found between the severity of degenerative changes on the X-ray images according to the Ahlbäck scale, and the increased mucoid degeneration (p < 0.0001), the severity of the degeneration of the collagen structure (p < 0.0001) and the presence of proprioceptors of PCLs (p < 0.0001). Conserving the PCL by the use of type cruciate retaining knee arthroplasty does not guarantee the preservation of correct proprioceptive sensation

A quantitative study of the arrangement of the suprascapular nerve and vessels in the suprascapular notch region: new findings based on parametric analysis

Background: When closed by the superior transverse scapular ligament (STSL), the suprascapular notch (SSN) creates an osseo-fibrous tunnel which acts as a pathway for the suprascapular nerve (SN). Anatomical variations are common in this region, and these can increase the risk of neuropathy by restricting the space for nerve passage. The aim of this study is to identify any correlation between the area reduction coefficient parameters and the SN and vessel arrangements in the SSN region. Material and methods: The SSN region was dissected in 88 formalin-fixed cadaveric shoulders (40 left and 48 right). During dissection, the topography of the SN, artery and vein was evaluated. Quantitative visual data analysis software was used to measure the areas of the STSL and the anterior coracoscapular ligament (ACSL), as well as the diameters of the SN and associated vessels, and to assign those structures to existing classifications. The area reduction coefficient (ARC) was calculated for each shoulder. Results: The area of the STSL (aSTSL) and ACSL (aACSL) were significantly larger in Type IV than Type I of the triad. Similarly, the aSTSL and area of the SSN (aSSN) were found to be significantly larger in Type IV than Type III. However, no significant differences were found in the ARC of the STSL (ARCSTSL), the ARC of the ACSL (ARCACSL) or the total ARC (ARCtotal). Conclusions: Although the aSTSL, aACSL and aSSN varied according to the type of SN and vessel arrangement, coefficient analysis (ARCSTSL, ARCACSL and ARCtotal) indicated that combined effect of these variations did not significantly affect SSN morphology.

The use of photovoltaic installations in order to improve the energy independency of a dairy equipped with a biogas reactor

This article attempts to demonstrate the importance of photovoltaic installations in improving the energy independence of a dairy equipped with a biogas reactor. It focuses on the development of photovoltaic technologies towards the wider use of solar cells in industrial power engineering installations, the potential of photovoltaic installations in Poland, and the storage and processing of energy from photovoltaic sources. An attempt has also been made to analyze the potential of a milk processing plant to meet its energy needs using photovoltaic sources

ZnO layers in application as TCL for new generation of solar cells

W ciągu ostatnich lat fotowoltaika wkroczyła na drogę bardzo dynamicznego rozwoju co przekłada się na gwałtowny wzrost wielkości produkcji ogniw słonecznych. Jednocześnie rosnący procent rynku stanowią cienkowarstwowe przyrządy nowej generacji o niskiej cenie i elastycznej konstrukcji. Do pełnego wykorzystania ich zalet w tym potencjalnej elastyczności struktury konieczna jest adaptacja odpowiednich transparentnych warstw przewodzących TCL (ang: Transparent Conductive Layers). Do grupy materiałów o potencjalnych korzystnych właściwościach z punktu wykorzystania w roli elektrody transparentnej należą odmiany tlenku cynku. Prezentowana praca jest poświęcona badaniom właściwości cienkich warstw ZnO:Al wytworzonych metodą PLD (ang: Pulsed Laser Deposition) do zastosowań w charterze transparentnej elektrody przewodzącej elastycznych, cienkowarstwowych ogniw słonecznych. Opis technologii wytwarzania jest uzupełniony o wszechstronną analizę parametrów mechanicznych i optoelektronicznych uzyskanych warstw na podłożach elastycznych i sztywnych. Zaprezentowane są modele numeryczne prototypowych konstrukcji ogniw. Przedstawione są również pierwsze wyniki pomiarów eksperymentalnej konstrukcji ogniwa słonecznego wyposażonego w otrzymaną warstwę.Rapid development of photovoltaics, which may be recently observed, is transferred to a mass-production scale of PV industry. At the same time constant growth of inexpensive thin-film, flexible devices leads to their significant share in the PV market. However, the potential profits of thin film applications are limited by proper technology and materials adaptation. Important element for most of these devices is a transparent electrode made of appropriate Transparent Conductive Layer (TCL). This paper is dedicated to practical investigation of ZnO:Al layer prepared by Pulsed Laser Deposition (PLD) technology as the emitter electrode of thin film solar cells. The production technology description is detailed and supplemented by mechanical and opto-electrical parameters measurements and simulations. Described layer is prepared and examined on traditional and transparent flexible substrates as well. The concepts and first realization of the new cell structure are given

An analysis of the electricity supply at a public building utilizing photovoltaic systems and a microturbine

W ostatnich latach poszukiwania nowych, efektywnych rozwiązań wytwarzania energii są skierowane na produkcję energii elektrycznej z wykorzystaniem nośników odnawialnych oraz przyjaznych środowisku. Spowodowało to wzrost zainteresowania ogniwami PV oraz systemami kogeneracyjnymi. W artykule, na tle historii rozwoju kolejnych generacji ogniw PV, zaprezentowano główne czynniki wpływające na ich parametry eksploatacyjne. Scharakteryzowano średnie dzienne promieniowanie słoneczne i prędkości wiatru w Łodzi. Przedmiotem badań była stacjonarna i nadążna instalacja fotowoltaiczna o łącznej mocy szczytowej 15 kWp oraz mikroturbina gazowa o mocy elektrycznej 30 kW, znajdujące się na Politechnice Łódzkiej na Wydziału Elektrotechniki, Elektroniki, Informatyki i Automatyki, zasilające sieć elektroenergetyczną budynków laboratoriów. Pomiary energetyczne prowadzono w 2016 roku i na ich podstawie wykonano analizę efektywności energetycznej i analizę finansową zaopatrzenia budynków w energię. Oceniono uzysk energii w modułach stacjonarnych i nadążnych oraz procentowe pokrycie energii elektrycznej z ogniw PV i mikroturbiny. Wyznaczono rozkład miesięcznych oszczędności, roczną oszczędność kosztów energii oraz czas zwrotu kosztów inwestycyjnych badanych systemów. Przeprowadzone badania pozwalają na stwierdzenie, że energia wytworzona przez moduły nadążne jest około 3 razy większa niż wytworzona w modułach stacjonarnych. Natomiast roczne oszczędności kosztów energii przy zastosowaniu mikroturbiny gazowej są około dziesięciokrotnie większe niż dla paneli nadążnych. Po przeprowadzeniu tej analizy można stwierdzić opłacalność stosowania agregatów kogeneracyjnych i paneli fotowoltaicznych, mimo dużych nakładów finansowych. Czas zwrotu nakładów inwestycyjnych wynosi około 12 lat podczas użytkowania instalacji przez cały rok.Recently, the search for new effective energy production solutions has been focused on the production of electricity using renewable and environmentally friendly carriers. This resulted in an increased interest in PV cells and cogeneration systems. The article looks at the main factors affecting their operational parameters against the background of the development history of subsequent generations of PV cells. Average daily solar radiation and wind velocity in Lodz were characterized. The research was done on a static and tracking system with a total peak power of 15 kWp and a 30 kW microturbine. PV panels are installed on the building of the Institute of Electrical Power Engineering of the Lodz University of Technology and they work as part of DERLab. A microturbine is inside the building. Energy measurements were carried out in 2016 giving grounds for the analysis of energy efficiency and financial analysis of the energy supply in buildings. Energy yields in the static and tracking system as well as percentage coverage of electricity from PV cells and microturbines were assessed. The distribution of monthly savings, annual savings of energy costs and the payback time of the investment costs of the systems subject to the test were determined. The research we have done allows us to say that the energy produced by follow-up modules is about 3 times greater than that generated in stationary modules. On the other hand, the annual savings of energy costs using gas micro-turbines are about 10 times higher than those of lagging panels. The analysis shows that it is possible to determine the profitability of the microturbine and photovoltaic panels use despite large financial outlays. The payback period of investment outlays is about 12 years when using the installation throughout the year

Innovative dairies - energy independence and waste-free technologies as a consequence of biogas and photovoltaic investments

This article presents the innovative perspectives of Polish and, above all, Lodz dairies. The possibilities of exploiting the potential of the enterprises in the dairy industry and their directions of development are described. It is emphasized that the dairy industry does not always have to be associated with constant demand for energy, but that it can also become its supplier. Biogas and photovoltaic solutions available to individual companies that have already been globally tested are proposed

Evaluation of the quality of titanium oxide and copper oxide layers by means of optical microscopy

The aim of this paper is to analyse high-resolution optical images of the surface layers of titanium oxide and copper oxide. The materials were produced using the PREVAC Modular Platform for layer deposition located at the University of Rzeszów. Images with a magnification of 50x were obtained using an optical microscope. On the basis of the results obtained, the quality of the layers was evaluated based on the image analysis. The quantitative method of analysis was applied, as a result of which the conditions of the manufacturing process for which the obtained layers had the highest homogeneity were indicated. The minimum range of grey shade counting was from 65 to 150 and the maximum range from 135 to 220. The standard deviation was from 8 to 40%

Optical and Structural Properties of Cu2O thin Film as Active Layer in Solar Cells Prepared by DC Reactive Magnetron Sputtering

A series of copper oxide thin films were synthesized through direct current magnetron sputtering on glass and silicon substrates with various process parameters. Initially, optical microscopy images and their histograms were analyzed to determine the optical quality of the obtained layers and then histograms were created using Image Histogram Generator software. Next, the morphology, and cross-section and layer composition of the samples were evaluated. Finally, the transmission spectra of the thin films were recorded. Transmittance and reflection spectra of the UV–vis analysis were utilized to calculate the optical band gap, the extinction coefficient, and the absorption coefficient of the oxidized layers. Samples showed low transmittance (up to 40%) in the region of 400 to 1000 nm. The mean absorption coefficient varied from ~3 · 105 to ~6 · 105 1/cm and from ~2 · 105 to ~4 · 105 1/cm in the region of 2 eV to 3.5 eV. The extinction coefficient ranged from 0 to 0.11 in the region from 300 to 3000 nm. Reflectance of the samples was ~20% in the region of 1000 to 2500 nm and ranged from 20%-50% in the region of 1000 to 3000 nm. We verified the process parameters of the Cu2O structure to improve the quality as a buffer layer. On the basis of this preliminary analysis, we propose the most promising and future-oriented solutions in photovoltaic applications