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1

Electromagnetic processing of molten copper alloys in the induction furnace with cold crucible

Smalcerz Albert, Blacha Leszek, Barglik Jerzy, Dolezel Ivo, Wieczorek Tadeusz

Archives of Electrical Engineering

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2024

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Vol. 73, nr 1

51--62

EN

Electromagnetic processing of molten copper is provided in a special kind of electrical furnace called an induction furnace with a cold crucible (IFCC), making it possible to successfully remove impurities from the workpiece. In order to analyze the process in a sufficient way not only electromagnetic, thermal and flow but also metallurgical and mass transfer phenomena in the coupled formulation should be taken into consideration. The paper points to an analysis of the kinetic process of lead evaporation from molten copper. It was shown that mass transport in the gas phase determines the rate of the analyzed evaporation process. The possibility of removal of lead from molten copper is analyzed and described.

2

Elimination of Zinc from Aluminum During Remelting in an Vacuum Induction Furnace

Smalcerz Albert, Blacha Leszek, Węcki Bartosz, Desisa D. G., Łabaj Jerzy, Jodkowski Maciej

Archives of Foundry Engineering

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2022

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Vol. 22, iss. 3

11--18

EN

In this paper, the results of the study on aluminium evaporation from the Al-Zn alloys (4.2% weight) during remelting in a vacuum induction furnace (VIM) are presented. The evaporation of components of liquid metal alloys is complex due to its heterogeneous nature. Apart from chemical affinity, its speed is determined by the phenomena of mass transport, both in the liquid and gas phase. The experiments were performed at 10-1000 Pa for 953 K - 1103 K. A significant degree of zinc loss has been demonstrated during the analysed process. The relative values of zinc loss ranged from 4 to 92%. Lowering the pressure in the melting system from 1000 Pa to 10 Pa caused an increase in the value of density of the zinc evaporating stream from 3.82x10-5 to 0.000564 gxcm-2xs-1 at 953 K and 3.32x10-5 to 0.000421 g xcm-2 for 1103 K. Based on the results of the conducted experiments. it was found that evaporation of zinc was largely controlled by mass transfer in the gas phase and only for pressure 10 Pa this process was controlled by combination of both liquid and gas phase mass transfer.

3

Pomiar menisku łzowego z wykorzystaniem keratografu i optycznej koherentnej tomografii

Zalewska Kinga, Kalwa Dominika, Młyniuk Patryk, Kałużny Bartłomiej J.

Optyka

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2020

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Nr 6

64--68

PL

Cel: Porównanie keratografu i optycznej koherentnej tomografii do pomiaru wysokości menisku łzowego dolnego w populacji osób zdrowych. Ocena korelacji wysokości menisku łzowego dolnego z następującymi parametrami: płeć, wiek, ankieta OSDI, test Schirmera. Metodyka: Badania przeprowadzono na 200 zdrowych oczach w Poradni Okulistycznej i Kliniki Okulistyki i Optometrii w Szpitalu Uniwersyteckim nr 2 im. dr. J. Biziela w Bydgoszczy. Do badania włączono 100 osób w wieku 18–75 lat (średni wiek: 61 lat). Następnie u każdego badanego została zmierzona wysokość menisku łzowego dolnego za pomocą keratografu Oculus 4 oraz DRI OCT Triton (Topcon), po pięć pomiarów dla każdego oka. Uzupełniająco każdy z pacjentów odpowiedział na 12 pytań z ankiety OSDI. Wyniki: Średni pomiar wysokości menisku łzowego dolnego u populacji osób zdrowych wykonany za pomocą OCT dla OP wynosił 266,55 ± 65,02 μm, natomiast dla OL 263,46 ± 67,62 μm. Natomiast średni pomiar u populacji osób zdrowych z wykorzystaniem keratografu dla OP wynosił 235,06 ± 43,83 μm, natomiast dla OL 234,40 ± 42,41 μm. Zauważono, że wysokość menisku łzowego dolnego jest wyższa u kobiet niż u mężczyzn zarówno w OCT, jak i w keratografie. Odnotowano niską zależność między wiekiem pacjentów oraz ankietą OSDI a wysokością dolnego menisku łzowego OP i OL zmierzoną za pomocą OCT i keratografu. Zależność między testem Schirmera a wysokością menisku łzowego dolnego wykazała umiarkowane podobieństwo dla OP i OL, zarówno w OCT, jak i keratografie. Wnioski: Wysokość menisku łzowego dolnego mierzonego za pomocą OCT jest wyższa niż wysokość uzyskana za pomocą keratografu. Z analizy wysokości menisku łzowego dolnego pacjentów można stwierdzić, że zarówno wiek pacjenta, jak i wynik ankiety OSDI nie mają istotnego związku z badanym parametrem.

EN

Aim: Comparison of two methods – with the use of a keratograph and optical coherence tomography – as the methods for measuring the highest of the inferior tear meniscus in the examined group of healthy people. Evaluation of the correlation of the inferior tear meniscus’s height with the following parameters: gender, age, OSDI questionnaire, Schirmer’s test.Methods: The study was conducted on 200 eyes. The query took place at the Ophthalmology and Optometry Clinic at the University Hospital No. 2 dr J. Biziela in Bydgoszcz, and included 100 persons aged 18–75 (the average age: 61 years old). Then the height of the inferior tear meniscus was measured for each of the examined people using keratograph Oculus 4 and DRI OCT Triton (Topcon), after five measurements for each eye. Complementary, each patient had answered 12 questions from the OSDI questionnaire. Results: The average measurement of the height of the inferior tear meniscus in a population of healthy people with OCT for OP was 266,55 ± 65,02 μm, for OL 263,46 ± 67,62 μm. Keratograph for OP was 235, 06 ± 43,83 μm, next to OL 234,40 ± 42,41 μm. It was noted that the tear meniscus heights are higher for women than for men in both OCT and keratography methods. There was a weak correlation between the age of people and the OSDI questionnaire, and the height of the OP and OL inferior tear meniscus measured by OCT and keratograph. Correlation between the Schirmer’s test and the height of the inferior tear meniscus showed a moderate similarity for OP and OL in both OCT and keratograph. Conclusions: The result of the height of the inferior tear meniscus measured in OCT is higher than the height obtained by using the keratograph. The analysis of the results of the inferior tear meniscus’s height shows that neither the age of the patient nor the result of the OSDI questionnaire has a significant correlation with the size of the measurement.

4

Microscopic tribological analysis of the knee joint

Ryniewicz A. M., Ryniewicz A., Pukaluk A., Pałka P.

Tribologia

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2017

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nr 3

147--154

EN

The aim of the conducted research was the evaluation of the topography and the structure of the superficial layer of meniscus and articular cartilage. These are surfaces that optimise the friction and lubrication process in the knee joint. The animal samples of the menisci and the articular cartilage were examined. The research was performed using scanning electron microscopes and an atomic force microscope. The structure of the surface of meniscus and articular cartilage is very regular. The collagenous fibres, which are embedded in the ground substance, are parallel to the surface. The undulation of the surface was observed. In the area of the anterior horn on tibia side of both menisci as well as in the anterior area of tibial plateau, the concavity and convexity pattern is evident. The observed cavities enable the accumulation of the synovial fluid. The synovial fluid plays the role of the lubricant in the knee joint, and its presence is highly desired during the load transmission.

PL

Celem przeprowadzonych badań była ocena topografii i struktury łąkotek oraz powierzchni stawowych, które zabezpieczają i optymalizują proces tarcia i smarowania w stawie kolanowym. Materiałem badań były łąkotki pobrane z prawidłowych stawów zwierzęcych oraz tkanka chrzęstna wypreparowana z powierzchni stawowych. Badania były realizowane na mikroskopach skaningowych oraz mikroskopie sił atomowych. Struktura warstwy wierzchniej chrząstki włóknistej oraz szklistej wykazała dużą regularność. Włókna kolagenowe biegnące równolegle do powierzchni i zatopione w substancji podstawnej tworzą łagodnie pofalowaną strukturę. Układ wgłębień i wzniesień jest najbardziej wyraźny na części przedniej plateau kości piszczelowej oraz w obszarze rogu przedniego łąkotek, po stronie kontaktującej się z plateau kości piszczelowej. W zaobserwowanych wgłębieniach może gromadzić się ciecz synowialna, która pełni rolę środka smarnego, i której obecność jest wysoce pożądana podczas przenoszenia obciążeń wewnątrz stawu kolanowego.

5

A new computer-based approach for fully automated segmentation of knee meniscus from magnetic resonance images

Saygılı A., Albayrak S.

Biocybernetics and Biomedical Engineering

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2017

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Vol. 37, no. 3

432--442

EN

Menisci are tissues that enable mobility and absorb excess loads on the knee. Problems in meniscus can trigger the disorder of osteoarthritis (OA). OA is one of the most common causes of disability, especially among young athlethes and elderly people. Therefore, the early diagnosis and treatment of abnormalities that occur in the meniscus are of significant importance. This study proposes a new computer-based and fully automated approach to support radiologists by: (i) the segmentation of medial menisci, (ii) enabling early diagnosis and treatment, and (iii) reducing the errors caused by MR intra-reader variability. In this study, 88 different MR images provided by the Osteoarthritis Initiative (OAI) are used. The histogram of oriented gradients (HOG) and local binary patterns (LBP) methods are used for feature extraction from these MR images along with the extreme learning machine (ELM) and random forests (RF) methods which are used for model learning (regression). As the first step of the pipeline, the most compact rectangular patches bounding the menisci are located. After this, meniscus boundaries are revealed by the morphological processes. Then, the similarities between these boundaries and the ground truth images are measured and compared with each other. The highest score is acquired with Dice similarity measurement with a success rate of 82%. A successful segmentation is performed on the diseased knee MR images. The proposed approach can be implemented as a decision support system for radiologists, while the segmented menisci can be used in classification of meniscal tear in future studies.

6

Comparison of durability of resorbable polymer pins in in vitro and in vivo conditions: preliminary study

Stodolak-Zych E., Pałka K., Szponder T., Nowicka K., Błażewicz S.

Engineering of Biomaterials

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2014

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Vol. 17, no. 128-129

87--89

EN

The work focuses on polymeric cartilage/bone pins (pegs) that were manufactured and tested to assess their application in meniscus injuries. The bone pins measuring 1,2 and 4 mm in diameter were produced from certified resorbable PLDLA by means of hot pressing (at 126oC). In order to establish the material characteristics, tests of mechanical properties, structural testing and stability tests were performed in vitro (an immersion medium: water/PBS buffer). It was established that after three months of incubation the initial implant’s bending strength (120 MPa) decreased by 35%, whereas its tensile strength (52 Pa) weakened by 60%. The degree of degradation did not affect the pH of the immersion fluid. The observed physical changes of the implant, such as: the mass decrease, the change of shape, the increase of crystallinity (DSC/TG), the number of polymer terminal groups (-OH, -COOH), proved the advanced degradation process of PLDLA pins. Implants of particular behaviour were inoculated into the tibia of a New Zealand rabbit. In vivo tests were conducted to confirm the changes observed in vitro. Monitoring of the degradation process was performed after three months following the implantation by means of control X-ray and computed microtomography (μCT).

7

Badanie reologiczne tkanki chrzęstnej łękotek pochodzących od zwierząt różnych gatunków

Cykowska M, Nikodem A.

Aktualne Problemy Biomechaniki

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2012

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z. 6

21--26

PL

W artykule przedstawiono wyniki badań wytrzymałościowych tkanki chrzęstnej. Przeprowadzone badania pozwoliły wyznaczyć krzywą pełzania dla tkanki chrzęstnej łękotek świni i bukata. Określone zostały także właściwości mechaniczne chrząstki stawowej. W trakcie badań zauważono, że różnice w budowie strukturalnej chrząstki stawowej pochodzących od zwierząt różnych gatunków wpływają na zachowanie się materiału oraz na wyniki pomiarów.

8

Dysfunction of locomotion after resection of the meniscus based on three-demensional motion analysis

Ogrodzka K., Chwała W., Ambroży T.

Acta of Bioengineering and Biomechanics

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2005

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Vol. 7, nr 1

97-102

EN

The three-dimensional analysis of the locomotion was carried out in a patient after resection of the medial meniscus in the left knee joint, using Vicon system. Examinations were performed two times. On the basis of the first examination an intensive three-month physiotherapy was planned and carried out. Angular changes of lower limb joints and changes of length of the selected muscles were taken into consideration.