15 research outputs found
Structure and Properties of the Multicomponent and Nanostructural Coatings on the Sintered Tool Materials
This chapter presents a general characteristic of sintered tool materials, in particular sintered sialons, nitride ceramics, injection-moulded ceramic-metallic tool materials and cemented carbides and a general characteristic of their surface treatment technology and especially chemical vapour deposition (CVD) and physical vapour deposition (PVD) techniques. The results of our investigations in technology foresight methods concerning the development prospects of surface engineering of sintered tool materials are presented. In the next subsection, we discuss the outcomes of multifaceted research carried out with advanced materials engineering methods, including high-resolution transmission electron microscopy, into the structure and properties of multicomponent, graded and multilayer coatings on the investigated tool materials, including the newly developed injection moulded ceramic-metallic tool materials. Special attention was drawn to a one-dimensional structure of the studied PVD and CVD coatings and its impact on the properties of coatings
Metallisation Technology of Silicon Solar Cells Using the Convectional and Laser Technique
The aim of the paper was to optimize the Selective Laser Sintering (SLS) and co-firing in the infrared conveyor furnace parameters in front Screen Printed (SP) contacts. The co-firing in the infrared conveyor furnace was carried out at various temperature. The SLS was carried out at various a laser beam, scanning speed of the laser beam and front electrode thickness. The investigations were carried out on monocrystalline silicon wafers. During investigations was applied a silver powder with the grain size of 40 μm. The contacts parameters are obtained according to the Transmission Line Model (TLM) measurements. Firstly, this paper shows the comparison between the convectional an unconventional method of manufacturing front contacts of monocrystalline silicon solar cells with the different morphology of silicon for comparative purposes. Secondly, the papers shows technological recommendations for both methods in relation to parameters such as: the optimal paste composition, the morphology of the silicon substrate to produce the front electrode of silicon solar cells, which were selected experimentally in order to produce a uniformly melted structure, well adhering to the substrate, with the low resistance of the front electrode-to-substrate joint zone
Computer-aided speech therapy
Trudność wymowy głoski „r” sprawia, że dzieci uczą się jej jako ostatniej, dlatego znaczna część polskiego społeczeństwa nie wymawia tej głoski poprawnie. Powoduje to problemy w nauce (dysleksja), jak również odbija się na życiu emocjonalnymi i społecznym. Bagatelizowany problem doskwiera również w dorosłym życiu, powodując częste kompleksy, które mogą wpływać niekorzystnie na zdrowie osób cierpiących na wadę wymowy. Przyczynia się także do rozwoju chorób cywilizacyjnych, takich jak depresja czy nerwica. Aby ułatwić osobom dorosłym naukę wymowy głoski „r”, stworzono specjalną aplikację wspierającą terapię logopedyczną, zawierającą zestaw ćwiczeń do nauki wraz z filmami instruktażowymi poprawnego wykonania ćwiczeń. Zmontowano również zestaw pomagający w oszacowaniu poprawności wymawiania tej głoski. Przedstawione rozwiązanie daje pacjentowi możliwość codziennych ćwiczeń i samodzielnej oceny ich wykonania oraz stanowi alternatywę dla sesji logopedycznych, które w przypadku osób dorosłych są nierefundowane.The consonant „r” is difficult to pronounce and children rarely learn its pronunciation before their fifth year of age. A significant part of Polish society is not able to pronounce “r”, correctly. This disability causes a lot of problems with learning (dyslexia) and has an influence on emotional and social life (complexes). It contributes to the development of civilization diseases, like depression or neurosis. To help adults learn to pronounce “r” properly, a specially designed computer-aided therapy is proposed. It consists of instructional videos with selected mouth and tongue movement trainings, selected speaking words and sentences with “r” exercises on several levels, as well as a special electronic circuit, which was designed and soldered to real-time visual assessment of the pronunciation accuracy. This solution offers patients the possibility of daily exercises with visual analysis of pronunciation accuracy and is an alternative to speech therapy sessions, which in case of adults, are not reimbursed by health care insurance system
Simulation of the microhardness and internal stresses measurement of PVD coatings by use of FEM METHODS OF ANALYSIS AND MODELLING
ABSTRACT Purpose: The goal of this work is to determine microhardness of coats and stresses obtained in PVD process with the use of finite elements method and comparative analysis with results obtained by laboratory investigations. Design/methodology/approach: Article introduce the usage of finite elements method for simulation of microhardness and stresses measurement process in TiN and TiC coats obtained in magnetron PVD process on high-speed steel ASP 30. Simulation of indenters depression in investigated coat permitted on disclosure of deformation of the layer PVD and allows to create the maps of stresses. Findings: Basing tensions obtained as a result of indenter depression in investigated surfaces we obtained the maps of stresses, deformations analyzed of coats, and then we calculated the microhardness. Research limitations/implications: On the basis of tensions in investigated coat obtained in result of computer simulation effected in ANSYS software environment was possible to compute the microhardness of the coating, and the results was compared with the microhardness data of coats received by physical examination with use of the Vickers method. Originality/value: From results of the simulation based on the finite element method is possible to compute the mechanical properties of coatings obtained in PVD process
Structure and properties of the tool ceramics with hard wear resistant coatings
This work presents studies of the structure and functional properties of coatings deposited onto indexable inserts made of nitride and sialon tool ceramics with the required properties, i.e. high adhesion, niicrohardness. high resistance to abrasive and diffusion wear in working conditions of high-performance cuttings tools. In the present paper the results of the investigations of the structure, texture, mechanical and functional properties of the Ti(C,N), (Ti.Al)N, Ti(C.N)+(Ti,Al)N coatings were presented. The 80% increase in the hardness of the coatings in comparison to the substrate material was reported. Test coatings are characterized by good adhesion to the substrate. The maximum Lc load of (Ti A1)N coat applied to the substrate from the nitride ceramics is equal to 42 N. In the studied coatings compressive stresses were found. The results of mechanical properties investigations, especially tribological ones correlate with the results of exploitation tests carried out during the cutting test
Structure and Properties of the Tool Ceramics with Hard Wear Resistant Coatings
This work presents studies of the structure and functional properties of coatings deposited onto indexable inserts made of nitride and sialon tool ceramics with the required properties, i.e. high adhesion, microhardness, high resistance to abrasive and diffusion wear in working conditions of high-performance cuttings tools. In the present paper the results of the investigations of the structure, texture, mechanical and functional properties of the Ti(C,N), (Ti,Al)N, Ti(C,N)+(Ti,Al)N coatings were presented. The 80% increase in the hardness of the coatings in comparison to the substrate material was reported. Test coatings are characterized by good adhesion to the substrate. The maximum Lc load of (Ti,Al)N coat applied to the substrate from the nitride ceramics is equal to 42 N. In the studied coatings compressive stresses were found. The results of mechanical properties investigations, especially tribological ones correlate with the results of exploitation tests carried out during the cutting test
Telerehabilitation approach for patients with hand impairment
Purpose: Telerehabilitation is one of the newest branches of telemedicine which has been developed because patients need regular trainings outside the medical institution but still under specialist supervision. It helps maintain regularity of exercises and reduces costs. The professional and advanced systems for telerehabilitation are presented in papers however, there is still lack of development of minor systems which provide therapeutic values and are more accessible to people. Therefore we focus on a solution for hand telerehabilitation of post-stroke patients, based solely on a personal computer and camera. Methods: We focused on the manipulative hand (fingers, metacarpus, wrist) movements trainings for patients with cerebral palsy. The contact between patient and physiotherapist is provided by using web cameras and web service. Additionally the camera can be used to monitor the effectiveness of performed exercises. Computer vision system keeps track of the patient’s hand movement. The digital image processing is used to detect if the patient performs exercises correctly. Results: We created web service and software application TeleReh that provides therapeutic values for the hand impaired people. The created system was evaluated by three physiotherapists, one doctor and a cerebral palsy patient. Conclusions Our solution applies to all patients who have undergone basic rehabilitation in hospital and need to continue hand rehabilitation at home. The main advantages are: easily adaptation to the individual needs and abilities, monitoring the progress by using automatically generated reports after each training session. It is worth noticing, that discussion between IT specialists, rehabilitants and patients was necessary to achieve good results
Adhesion of SiO2 layers deposited by means of sol-gel and ALD methods on 316LVM steel
Celem prezentowanej pracy była ocena przydatności stosowania warstw SiO2 naniesionych dwiema metodami Atomic Layer Depositon (ALD) i zol-żel na podłoże ze stali 316LVM stosowanej na implanty w układzie sercowo-naczyniowym. Do badań wytypowano stal austenityczną 316LVM i poddano ją następującym modyfikacją powierzchni: polerowanie elektrochemiczne, pasywacja chemiczna, naniesienie warstw SiO2 zarówno metodą ALD, jak i zol-żel. Wymienione metody są obecnie najczęściej stosowane w przypadku nanoszenia warstw powierzchniowych na implanty. W ramach oceny przydatności zaproponowanych metod modyfikacji powierzchni analizowanej stali autorzy pracy przeprowadzili badania własności mechanicznych, elektrochemicznych oraz fizycznych. Na podstawie uzyskanych wyników stwierdzono, że niezależnie od metody nanoszenia zaobserwowano korzystny wpływ warstwy SiO2 na badane własności w porównaniu do stanu wyjściowego. Ponadto stwierdzono, że najkorzystniejszym zespołem własności mechanicznych, elektrochemicznych i fizycznych charakteryzuje się warstwa SiO2 naniesioną metodą ALD. Tak naniesiona warstwa charakteryzowała się większą siłą krytyczną powodującą delaminację warstwy, większą odpornością na korozję wżerową oraz większym kątem zwilżania wodą (charakter hydrofobowy), co w przypadku implantów stosowanych w układzie krwionośnym jest zjawiskiem pożądanym, ponieważ wymagana jest mała adsorpcja białek, która ogranicza proces krzepnięcia krwi. Zaproponowanie odpowiednich wariantów obróbki powierzchniowej z wykorzystaniem metody ALD oraz zol-żel ma perspektywiczne znaczenie i przyczyni się do opracowania warunków technologicznych o sprecyzowanych parametrach wytwarzania powłok tlenkowych na implantach stosowanych w układzie sercowo-naczyniowym.The aim of this study was to evaluate the usefulness of SiO2 layers deposited by two methods - atomic layer deposition (ALD) and sol-gel, on the surface of stainless steel 316LVM used in application of cardiovascular implants. In assessing the suitability of the proposed methods to modify surfaces of the analysed steel, authors carried out tests of mechanical, electrochemical and physical properties. The austenitic steel 316LVM was chosen and subjected to the following surface modifications: electrochemical polishing, chemical passivation and application of the SiO2 layer using both methods – ALD and sol-gel. These methods were proposed for research, because they are most commonly used in the case of applying surface layers to implants. Based on the obtained results, it was observed that regardless of the method of application, the SiO2 layer has beneficial effect on examined properties compared to control. Moreover, it was found that the SiO2 layer deposited by ALD is characterized by the most preferred combination of mechanical, physical and electrochemical properties. The layer obtained by this method is characterized by a higher critical force, which causes delamination of the layers, higher resistance to pitting corrosion and higher water contact angle (hydrophobic character), which is a desirable phenomenon in the case of implants used in the circulatory system, resulting in lower adsorption of proteins and blood clothing. Proposing of suitable variants of surface treatment using the ALD and sol-gel methods is of perspective importance. It will contribute to the development of technological conditions with specified parameters for the production of oxide coatings on implants used in the cardiovascular system
Age-related macular degeneration - disease of the 21st century
Starcze zwyrodnienie plamki żółtej (AMD) jest chorobą cywilizacyjną XXI wieku. Charakteryzuje się tworzeniem nowych patologicznych naczyń krwionośnych, jak również ucieczką elementów morfotycznych i białek poza naczynia już istniejące, co skutkuje zapoczątkowaniem procesu zapalnego. Nieleczenie tej choroby może prowadzić do ślepoty. Ze względu na częste występowanie AMD i brak skutecznego leczenia farmakologicznego prowadzone są liczne badania w celu ulepszenia istniejących i wynalezienia nowych metod diagnostyki i leczenia tej choroby. Przeprowadzone badania kliniczne potwierdziły, że angiografia fluoresceinowa umożliwia obserwowanie postępu AMD. Dostrzegając możliwości komputerowej analizy wyników angiografii, w ramach niniejszej pracy zaprojektowano program komputerowy, który daje możliwość analizy wyników badań wykonanych za pomocą angiografii fluoresceinowej oraz testu Amslera. Szybki dostęp do bazy danych chorych na AMD ułatwi lekarzom pracę z pacjentem i zaoszczędzi cenny czas. Istotnym elementem zaproponowanego rozwiązania jest możliwość gromadzenia, przechowywania oraz analizy wyników badań pacjentów chorych na AMD.Age-related macular degeneration (AMD) is a twenty-first century civilization disease. It is characterized by pathological formation of new blood vessels, as well as an escape of blood cells and proteins beyond existing vessels. If untreated, the disease can lead to blindness. Due to the frequent occurrence of AMD and the lack of effective pharmacological treatment, series of studies are conducted to improve the existing and invent new methods of diagnosis and treatment. Clinical trials have confirmed that fluorescein angiography allows observation of AMD progress. A computer program was designed exploiting computer analysis of angiography result. The program allows analyzing the results of tests carried out by fluorescein angiography and Amsler test. Quick access to a database of patients with AMD will help physicians work with the patient and save valuable time. An important element of the proposed solution is the ability to collect, store, and analyze the results of studies of patients with AMD