This work deals with non-destructive testing of artificial joints made from the austenitic steel SUS316L based on eddy current method. The technique is appropriate for final investigation of artificial joints before insertion the prosthesis into human body to avoid repeated operations. The most commonly implanted joints - knee and hip joint are evaluated in this study. The eddy current probe consists of one coil, which has both the excitation and sensing functions. Five detects are inspected using three different frequencies. The numerical simulations from Opera software with experiments are compared in this article to obtain the most appropriate frequency. The aim of this work is evaluation which frequency provides the biggest magnitude difference between individual simulated signals with various depths if surface defects are inspected.
- Keywords
- testování umělých kloubů, vířivé proudy, austenitická ocel,
- MeSH
- Hip Prosthesis * standards MeSH
- Humans MeSH
- Joint Prosthesis standards MeSH
- Knee Prosthesis * standards MeSH
- Chromium Alloys standards MeSH
- Materials Testing * methods standards instrumentation statistics & numerical data MeSH
- Check Tag
- Humans MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
Experimental modal analysis (EMA) of ultrasonic waveguides is important for many applications including design of ultrasonic surgical tools. However, most of the known sensors and instruments for measuring parameters of ultrasonic vibrations are limited to the measurements on the face surface of the ultrasonic waveguide and therefore unable to determine the spatial distribution of the parameters along its length, which in turn makes it difficult to identify natural modes and shapes. The article describes EMA of ultrasonic surgical waveguides based on the effect of inverse magnetostriction. During vibration of an ultrasonic waveguide the inverse magnetostriction generates alternating magnetic field which can be detected by means of an induction coil. Spatial resolution of the measurements can be achieved by application of the sensors with flat (spiral) induction coils. The sensors used in the study have simple design and low cost making them affordable for wide circle of scientists and engineers. The results of experimental studies implemented on exemplary waveguide for ultrasonic angioplasty made of AISI 321 steel are presented and discussed. The article also discusses the methods for theoretical and experimental determination of the sensitivity of the sensors used in the study. Experimental data are validated by comparing them to the results of computer-aided modal analysis using the finite element method (FEM) and found to be in good agreement with the results of FEM modeling (relative deviation of the vibratory displacements amplitude is about 4.7 %). As it follows from the experimental data and their comparison to the results of FEM modeling, the effect of inverse magnetostriction can be efficiently used for EMA of ultrasonic waveguides.
With growing interest in monitoring the health status of a human has raised demands on measuring systems and devices. It is important to develop monitoring system with user friendly and comfortable interface. This applies not only to setup and control but also to wearing and manipulation. Therefore, the replacement of conventional metal, rubber and selfadhesive electrodes by electrodes with thin-film conductive layer is desirable. These electrodes combine good electrical properties altogether with comfortable wearability, ease of manipulation and low-cost fabrication. The indicated factors allow these electrodes to be used in commercial measuring systems and devices. Their applicability in long term measurements is subject to meeting additional requirements, such as chemical and mechanical resistance. Abrasion caused by rubbing the human skin during standard measurements might affect the functionality of the electrode. Four types of electrodes based on Au, ITO, Graphite filled polymer and PEDOT:PSS underwent series of testing of their abrasion resistance. A surface with specific roughness and pressure force was used. A change in amplitude of testing ECG signal was measured as a function of number of abrasion cycles for all electrodes.
Chlorinated hydrocarbons are very often used and are relatively dangerous substances from healthy risk point of view. While manipulating with them, mainly in large volumes, individual protective equipment (IPE) must be used in a protection position. Users are supposed to know the construction material breakthrough time especially in case of long-term usage of personal IPE and in the situation when contamination of them is real. Studying connections between a chemical compound structure and the structure of IPE characterised by barrier materials enables us to understand present body protective devices protection quality and gives us an option to choose barrier materials with targeted properties. In this article there are results of breakthrough time of isolating protection folio with a butyl rubber barrier layer in relation to chlorinated ethanes. This material is used for protection of specialists of both Fire Rescue Brigades and the Czech Armed Forces Chemical Corps. The PIEZOTEST device has been used for detection of permeated chemicals. The Quartz Crystal Microbalance (QCM) sensor is a part of PIEZOTEST device.
- Keywords
- lag-time, butyl rubber, steady state permeation rate, breakthrough time,
- MeSH
- Time Factors MeSH
- Hydrocarbons, Chlorinated * chemistry MeSH
- Elastomers chemistry MeSH
- Ethane analogs & derivatives chemistry MeSH
- Ethylene Dichlorides chemistry MeSH
- Quartz Crystal Microbalance Techniques statistics & numerical data MeSH
- Hazardous Substances chemistry MeSH
- Protective Clothing * MeSH
- Permeability * MeSH
- Solubility MeSH
- Materials Testing methods statistics & numerical data MeSH
- Trichloroethanes chemistry MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
Jedním ze základních předpokladů úspěšné ortodontické léčby je kontrolované působení ortodontických sil. Cílem práce je analýza silových charakteristik běžně používaných ortodontických elastických řetízků. Byl zkoumán vliv různých parametrů (tvar řetízku, výrobce, přestretching) na produkci sil v závislosti na čase. Byl vytvořen soubor 18 typů běžně používaných elastických řetízků od 7 různých výrobců. Řetízky byly rozděleny do 3 skupin, podle délky mezičlánku. Následně byly protaženy o 50 % a 100 % jejich původní délky a byl měřen pokles síly v čase ve zvolených časových intervalech ve standardizovaných podmínkách. studie prokázala, že síly produkované elastickými řetízky jsou velké a značně se liší dle výrobce. Během prvních 24 hodin dochází k výraznému poklesu sil, poté síly klesají už jen velmi pomalu. Vliv prestretchingu na snížení výchozích sil byl patrný pouze u následného protažení řetízku o 50 %, při 100 % protažení tento vliv prokázán nebyl.
Controlled delivery of orthodontic forces is one of the precoinditions tor successful ortnoaontlc treatment. The work alms to give the analysis of common orthodontic elastic chains force characteristics. The study focuses on the effect of individual parameters (chain shape, manufacturer, prestretching) on time-related delivery of forces. Our sample included 18 types of common elastic chains produced by 7 manufacturers. The chains were subdivided into 3 groups according to the length of their connecting link. Subsequently, the chains were elongated by 50% and 100% of their original length, and the decrease of force over a period of time was measured at given intervals under standardized conditions. The study proves that forces delivered by elastic chains are big, and that products of individual manufacturers are different. Within the first 24 hours forces decrease significantly, afterwards they lessen very slowly. The effect of prestretching on the decrease of initial forces was evident only in subsequent stretching of a chain by 50%. In case of 100% stretching the effect was not proved.
- Keywords
- elastický řetízek, pokles síly, mezičlánek, prestretching,
- MeSH
- Dental Stress Analysis classification methods MeSH
- Elastomers * therapeutic use MeSH
- Humans MeSH
- Orthodontics, Corrective MeSH
- Orthodontic Wires MeSH
- Orthodontic Appliance Design MeSH
- Orthodontic Retainers MeSH
- In Vitro Techniques MeSH
- Materials Testing * methods statistics & numerical data MeSH
- Friction physiology MeSH
- Check Tag
- Humans MeSH
Structured and complex data can be found in many applications in research and development, and also in industrial practice. We developed a methodology for describing the structured data complexity and applied it in development and industrial practice. The methodology uses fractal dimension together with statistical tools and with software modification is able to analyse data in a form of sequence (signals, surface roughness), 2D images, and dividing lines. The methodology had not been tested for a relatively large collection of data. For this reason, samples with structured surfaces produced with different technologies and properties were measured and evaluated with many types of parameters. The paper intends to analyse data measured by a surface roughness tester. The methodology shown compares standard and nonstandard parameters, searches the optimal parameters for a complete analysis, and specifies the sensitivity to directionality of samples for these types of surfaces. The text presents application of fractal geometry (fractal dimension) for complex surface analysis in combination with standard roughness parameters (statistical tool).
- Keywords
- BIOMET 3i,
- MeSH
- Dental Stress Analysis * statistics & numerical data MeSH
- Dental Implantation, Endosseous MeSH
- Bone Screws MeSH
- Stress, Mechanical MeSH
- Dental Leakage MeSH
- Dental Abutments MeSH
- Statistics as Topic MeSH
- Materials Testing * statistics & numerical data MeSH
- Dental Implants, Single-Tooth * MeSH
- Dental Implants MeSH
- Publication type
- Evaluation Study MeSH
- Comparative Study MeSH
Nanotkaniny dopované fotosenzibilizátorem 5,10,15,20-tetrafenylporfyrinem (TPP) byly připraveny pomocí elektrospiningu z vysoce hydrofilního polyuretanu (TecophilicTM) a charakterizovány mikroskopickými metodami a časově rozlišenou spektroskopií. V in vitro experimentech byla vyvolána kompletní inhibice bakteriálního růstu tří testovaných bakteriálních kmenů na povrchu nanotkaniny, s enkapsulovaným TPP po ozáření viditelným světlem. Antibakteriální efekt je založen na fotogeneraci cytotoxického singletového kyslíku O2(1Δg) po ozáření viditelným světlem. Klinicky byly antibakteriální účinky testovány u 162 pacientů s chronickými bércovými vředy. Aplikace ozařované nanotkaniny s fotosenzibilizátorem vedla k 35% zmenšení velikosti vředu, což bylo dokumentováno pomocí počítačového měření velikosti rány. Bolestivost ve vředu, zjišťována vizuální analogovou škálou, se snížila o 71 %. Tato metoda je účinnou alternativou lokálních antibiotik a antiseptik u chronických ran a nabízí široké spektrum použití v medicíně, především v dermatologii, popáleninových centrech a chirurgii.
Nanofiber textiles doped with 5,10,15,20-tetraphenylporphyrin (TPP) photosensitizer prepared by electrospinning from highly hydrophilic polyurethane TecophilicTM were characterized with microscopic methods and time-resolved spectroscopy. Complete inhibition of bacterial growth of the three tested bacterial strains on the surface of nanofiber textiles with encapsulated TPP was observed on illuminated samples in vitro. The antibacterial effect is based on photogeneration of cytotoxic singlet oxygen O2(1Δg) upon illumination by visible light. The antibacterial activity was also clinically tested in 162 patients with chronic leg ulcers. The application of illuminated doped nanofiber textiles yielded to a 35% decrease in wound size as assessed with computer aided wound tracing. The wound related pain estimated by the visual analogue scale declined by 71%. This methodology seems to be an effective alternative to topical antibiotics and antiseptics in chronic wounds and shows broad spectrum of application in medicine, particularly in dermatology, burn units and surgery.
- Keywords
- bércový vřed, fotodynamická terapie, fotosenzibilizátor, nanotkanina,
- MeSH
- Anti-Bacterial Agents pharmacology chemistry MeSH
- Varicose Ulcer * drug therapy MeSH
- Adult MeSH
- Escherichia coli isolation & purification drug effects radiation effects MeSH
- Photochemotherapy * methods MeSH
- Photosensitizing Agents therapeutic use MeSH
- Wound Healing drug effects radiation effects MeSH
- Culture Media MeSH
- Middle Aged MeSH
- Humans MeSH
- Pain Measurement statistics & numerical data MeSH
- Nanofibers * therapeutic use MeSH
- Porphyrins therapeutic use MeSH
- Pseudomonas aeruginosa isolation & purification drug effects radiation effects MeSH
- Wounds and Injuries microbiology MeSH
- Retrospective Studies MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Singlet Oxygen chemistry MeSH
- Patient Satisfaction MeSH
- Staphylococcus aureus isolation & purification drug effects radiation effects MeSH
- In Vitro Techniques MeSH
- Materials Testing statistics & numerical data MeSH
- Treatment Outcome MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
Cílem práce bylo stanovení koroze keramických materiálů. Celkem bylo vybráno pro analýzu 11 druhů keramických materiálů, jejichž složení bylo kvalitativně sledováno pomocí rentgen-fluorescenční spektrometrie. Pro sledování korozního chování byl zvolen výluh kyselinou chlorovodíkovou, který byl analyzován pomocí ICP-OES. Ve výluzích bylo nalezeno měřitelné množství následujících prvků: sodíku, hořčíku, železa, manganu, zinku, křemíku, hliníku, yttria a titanu. Zirkonium a zlato byly detekovány pouze ve velmi malém množství. Žádný z dentálních materiálů včetně keramiky není zcela odolný vůči korozi. IGA NS/9744–3–2008.
The aim of this study was to determine the level of selected ceramic materials corrosion. In total, 11 types of ceramic materials have been chosen for the analysis. The composition of ceramic materials was qualitatively evaluated by X-ray spectrometry. For evaluation of a corrosive behavior, leaching in hydrochloric acid was used. Extracts were analyzed by mean ICP-OES. In extracts, measurable amounts of followed elements were found: sodium, magnesium, iron, manganese, zinc, silicon, aluminium, yttrium and titanium. Zirconium and gold were found in leachates. None of the known dental materials including ceramics can preserve absolute resistance against all corrosion forms.
- Keywords
- spektrometrie,
- MeSH
- Financing, Organized MeSH
- Spectrometry, Fluorescence instrumentation utilization MeSH
- Ions analysis adverse effects toxicity MeSH
- Ceramics analysis classification adverse effects MeSH
- Corrosion MeSH
- Humans MeSH
- Materials Testing standards statistics & numerical data MeSH
- Dentures MeSH
- Check Tag
- Humans MeSH
Úvod a cíl práce: Mezi největší výhody keramických materiálů patří i jejich všeobecně uznávaná biologická netečnost. Cílem práce bylo hodnocení koroze polykrystalického sklem infiltrovaného materiálu In-Ceram Spinell (Vita, SRN) v běžně dostupných nápojích a roztocích in vitro. Materiál: Keramický materiál In-Ceram Spinell (Vita, SRN) byl podroben imerznímu testu, kdy byla použita následující vyluhovací média: Ice Tea Peach (Lidl Stiftung & Co. KG, DEU; pH 2,99), Freeway Cola (Lidl Stiftung & Co. KG, DEU; pH 2,42), červené víno Cabernet Sauvignon (Vinné sklepy Peter Metres KG; pH 3,59), bílé víno (Izrael; pH 3,23), džus 100% pomeranč (Relax Ltd., NZL; pH 3,76), ústní voda Colgate Plax Whitening (Colgate – Palmolive, SUI; pH 8,04), 0,9% NaCl (pH 5,35), 0,5% kyselina octová (pH 2,56), 2% kyselina citronová (pH 1,98), 0,1M HCl (pH 1,54), redestilovaná voda (pH 5,70). Vzorky uvedeného materiálu byly vyluhovány při 37 °C po dobu 7 dní. U vzorků byl hodnocen jejich hmotnostní úbytek a dále byly sledovány změny jejich barvy. Uvedená vyluhovací média byla po imerzním testu podrobena prvkové analýze pomocí optické emisní spektrometrie s indukčně vázaným plazmatem (ICP OES), kdy byl sledován nárůst koncentrací vybraných prvků. Výsledky: Největší hmotnostní úbytek byl zjištěn u vzorků testovaných v kyselině citronové. Z výsledků je patrné, že s klesajícím pH roste úbytek hmotnosti. Změna barvy byla zaznamenána u vzorků testovaných ve Freeway cole a v červeném víně, které byly pokryté různě barevnou usazeninou. Analýza pomocí ICP OES prokázala nárůst koncentrací vápníku, hořčíku, hliníku, yttria, křemíku a dalších prvků ve výluzích. Závěr: Ač bývá dentální keramika označována jako chemicky inertní materiál, při testování keramického materiálu In-Ceram Spinell, kdy jako korozní činidla sloužily vybrané nápoje a roztoky, bylo prokázáno, že tomu tak není. Klíčová slova: prvková analýza – optická emisní spektrometrie – dentální keramický materiál – In-Ceram Spinell – imerzní test – koroze
Introduction: The biocompatibility of ceramic materials belongs to the best benefits of these dental materials. Aim: Paper presents in vitro corrosive behaviour testing procedure of ceramic dental material in preselected beverages and solutions. Methods: The ceramic material In-Ceram Spinell (Vita, Germany) was immersed using following leaching agents: Ice Tea Peach (Lidl Stiftung & Co. KG, DEU; pH 2.99), Freeway Cola (Lidl Stiftung & KG, DEU; pH 2.42), red wine Cabernet Sauvignon (Wine Cellars Peter Metres KG; pH 3.59), white wine (Israel; pH 3.23), juice 100% orange (Relax Ltd., NZL; pH 3.76), mouth wash Colgate Plax Whitening (Colgate – Palmolive, SUI; pH 8.04), 0.9% NaCl (pH 5.35), 0.5% acetic acid (pH 2.56), 2% citric acid (pH 1.98), 0,1M HCl (pH 1.54), redistilled water (pH 5.70). Samples of the mentioned material were immersed at 37 °C during seven days. The change of sample masses and the change of colour was followed. After immersion test, leaching agents used we analysed using inductively coupled plasma optical emission spectrometry (ICP OES) and the increase in concentration of chosen elements was monitored. Results: The highest loss up of sample masses was found for samples tested in citric acid. The loss of material mass is related to pH. The colour change was monitored in samples treated in Freeway Cola and red wine, they came under different colour changes. ICP OES analysis demostrated the increase in concentration of calcium, magnesium, aluminium, yttrium, silica and other elements in extracts. Conclusion: Though the dental ceramics is considered to be bioinert, the corrosive behaviour of In-Ceram Spinell was monitored in the presence of currently used beverages and solutions. Key words: elementary analysis – optical emission spektrometry – dental ceramics – In-Ceram Spinell – immersion test – corrosion
- Keywords
- prvková analýza, optická emisní spektrometrie s indukčně vázaným plazmatem, imerzní test, In-Ceram Spinell, ICP OES,
- MeSH
- Biocompatible Materials MeSH
- Chemistry Techniques, Analytical MeSH
- Mass Spectrometry methods instrumentation statistics & numerical data MeSH
- Ceramics * chemistry adverse effects MeSH
- Hydrogen-Ion Concentration MeSH
- Corrosion * MeSH
- Citric Acid MeSH
- Acetic Acid MeSH
- Beverages * analysis MeSH
- Immersion MeSH
- Surface Properties MeSH
- Elements MeSH
- Solutions chemistry MeSH
- In Vitro Techniques MeSH
- Materials Testing methods instrumentation statistics & numerical data MeSH
- Mouthwashes MeSH
- Wine MeSH
- Water MeSH
- Dental Porcelain chemistry adverse effects MeSH
- Publication type
- Evaluation Study MeSH
- Research Support, Non-U.S. Gov't MeSH
