Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "tomography" wg kryterium: Temat

  Lista filtrów
Wyrównaj
Wyświetlanie 1-15 z 97
Tytuł:
Fibromuscular dysplasia – a case description
Autorzy:
Leksa, Natalia
Seweryn, Bartosz
Uberman-Kluz, Dominika
Galiniak, Sabina
Kawalec, Magdalena
Powiązania:
https://bibliotekanauki.pl/articles/454927.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Rzeszowski. Wydawnictwo Uniwersytetu Rzeszowskiego
Tematy:
fibromuscular dysplasia
arteries
computed tomography
Opis:
Introduction. Fibromuscular dysplasia is an idiopathic, non-inflammatory and non-atherosclerotic disease that affects the walls of arteries (mostly renal and carotid arteries). Histological classification distinguishes three main types of the disease, depending on the structural changes occurring in one of the three layers of arterial vessel walls. Objective. We present here a case of fibromuscular dysplasia affecting the internal carotid arteries. Case description. This article describes the case of a 52-year-old female patient with hypertension, hyperlipidemia, and a cardiac pacemaker in whom computed tomography angiography revealed a narrowing of the internal carotid arteries without atherosclerotic symptoms. We describe the diagnostic methods and various types of treatment that the patient suffering from fibromuscular dysplasia was subjected to. Conclusions. Due to a low detection rate of fibromuscular dysplasia, if the disease is suspected, all available diagnostic methods should be employed. Taking into account the unknown etiology of the disease, it is not possible to use a preventive therapy, or a therapy focused on stalling the progression of the disease
Źródło:
European Journal of Clinical and Experimental Medicine; 2018, 1; 63-67
2544-2406
2544-1361
Pojawia się w:
European Journal of Clinical and Experimental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of the accuracy of preoperative imaging methods in the diagnosis of hepatic single-chamber echinococcosis
Autorzy:
Hołody-Zaręba, Joanna
Zaręba, Konrad Piotr
Kędra, Bogusław
Powiązania:
https://bibliotekanauki.pl/articles/1396512.pdf
Data publikacji:
2013-12-01
Wydawca:
Index Copernicus International
Tematy:
single-chamber echinococcosis
ultrasonography
computed tomography
Opis:
Echinococcosis is an infectious disease, caused by larval stages of cestode species of the genus Echinococcus. The course of the disease is determined on the basis of the location and larval size. In 80-95% of cases echinococcosis is located in the liver and lungs, rarely in the brain. Symptoms are usually uncharacteristic for an uncomplicated disease. The diagnosis of echinococcosis is based on imaging and immunodiagnostic tests. The aim of the study was to assess the accuracy of preoperative imaging methods in the diagnosis of hepatic single- chamber echinococcosis. Material and methods. Amongst the 110 patients with hepatic cysts diagnosed during the period between 2000 and 2009, a group of 30 subjects with suspicion of single-chamber echinococcosis (ultrasound and CT) was isolated. The imaging methods visualized structures typical for hydatid cysts: the mother cyst with satellite cysts called “ honeycomb appearance”, cysts with calcified walls and compartments, and endocyst separation called “water lily-sign”. The study group comprised 22 female and 8 male patients with an average age of 52±16.2 years. The histopathological examination of the excised cyst verified the diagnosis. Results. Single-chamber echinococcosis was finally recognized in 19 cases, while in the 11 remaining cases the parasitic disease was excluded. The sensitivity of imaging methods was estimated at 73.7%, specificity - 88.9%, negative predictive value - 61.5%, positive predictive value - 93.3%, Youden`s factor - 0.626, and Φ index - 0.586. Conclusions. In conclusion, the presence of an unilocular cyst with an uniform anechoic content can be a simple cyst or single-chamber echinococcus cyst. The typical, characteristic image of a hydatid cyst, such as the “water lily-sign” is rarely observed during imaging examinations. It has also been shown that cystic calcification, observed during ultrasonography and computed tomography was evidence of the parasitic character of the lesion.
Źródło:
Polish Journal of Surgery; 2013, 85, 12; 693-698
0032-373X
2299-2847
Pojawia się w:
Polish Journal of Surgery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ultrasound Transmission Tomography Imaging of Structure of Breast Elastography Phantom Compared to US, CT and MRI
Autorzy:
Opieliński, K. J.
Pruchnicki, P.
Gudra, T.
Podgórski, P.
Kraśnicki, T.
Kurcz, J.
Sąsiadek, M.
Powiązania:
https://bibliotekanauki.pl/articles/176996.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ultrasound transmission tomography
UTT
ultrasonography
US
computed tomography
magnetic resonance
MR
mammography
breast biopsy phantom
Opis:
The paper presents an analysis of the results of ultrasound transmission tomography (UTT) imaging of the internal structure of a breast elastography phantom used for biopsy training, and compares them with the results of CT, MRI and, conventional US imaging; the results of the phantom examination were the basis for the analysis of UTT method resolution. The obtained UTT, CT and MRI images of the CIRS Model 059 breast phantom structure show comparable (in the context of size and location) heterogeneities inside it. The UTT image of distribution of the ultrasound velocity clearly demonstrates continuous changes of density. The UTT image of derivative of attenuation coefficient in relation to frequency is better for visualising sharp edges, and the UTT image of the distribution of attenuation coefficient visualises continuous and stepped changes in an indirect way. The inclusions visualized by CT have sharply delineated edges but are hardly distinguishable from the phantom gel background even with increased image contrast. MRI images of the studied phantom relatively clearly show inclusions in the structure. Ultrasonography images do not show any diversification of the structure of the phantom. The obtained examination results indicate that, if the scanning process is accelerated, ultrasound transmission tomography method can be successfully used to detect and diagnose early breast malignant lesions. Ultrasonic transmission tomography imaging can be applied in medicine for diagnostic examination of women’s breasts and similarly for X-ray computed tomography, while eliminating the need to expose patients to the harmful ionising radiation.
Źródło:
Archives of Acoustics; 2013, 38, 3; 321-334
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pomiary dwuenergetycznej tomografii (Dual Energy CT) w celu badania skał
Calibration of dual energy CT scans for rock core examination
Autorzy:
Dohnalik, Marek
Kaczmarczyk, Jan
Powiązania:
https://bibliotekanauki.pl/articles/1834984.pdf
Data publikacji:
2019
Wydawca:
Instytut Nafty i Gazu - Państwowy Instytut Badawczy
Tematy:
tomografia komputerowa
Dual Energy CT
DECT
dwuenergetyczna tomografia
computed tomography
dual energy CT
dual energy computed tomography
Opis:
: Jedno z pierwszych zastosowań rentgenowskiej tomografii komputerowej w geologii miało miejsce w 1974 roku. Tomografia rentgenowska (CT) umożliwia nieinwazyjne obrazowanie badanych przedmiotów. Wynikiem pomiaru tomograficznego jest przestrzenny obraz, przedstawiający zmiany absorpcji promieniowania rentgenowskiego. Powstaje on poprzez wyliczenie, podczas procesu rekonstrukcji, wartości absorpcji dla każdego punktu badanego przedmiotu. Istotną zaletą tomografów komputerowych jest możliwość przebadania dużych obiektów (metrowych odcinków rdzenia) w bardzo krótkim czasie. Ich wadą jest natomiast względnie niska rozdzielczość pomiaru. Każdy woksel na obrazie tomograficznym ma przypisaną konkretną wartość zaczernienia proporcjonalną do liniowego współczynnika tłumienia, zależną od gęstości elektronowej i efektywnej liczby atomowej, uśrednionych w obrazowanej przestrzeni (zakres uśredniania określa rozdzielczość obrazu tomograficznego). Dysponując dwoma obrazami, zarejestrowanymi przy dwóch różnych energiach pomiaru, można podjąć próbę rozdziału obrazu na dwie składowe: pierwszą – zależną od gęstości elektronowej i drugą – zależną od efektywnej liczby atomowej. Celem opisanych prac jest pokazanie możliwości wykorzystania dwuenergetycznej tomografii komputerowej (DECT) do charakterystyki litologiczno-gęstościowej rdzeni wiertniczych. Aby wykorzystać obrazy tomograficzne do otrzymania wymienionych wielkości fizykochemicznych konieczna jest standaryzacja obrazów. W pracy przedstawiono proces wyznaczania współczynników kalibracyjnych, które są niezbędne do przeliczania wartości współczynników absorpcji, będących bezpośrednim wynikiem rekonstrukcji pomiaru tomograficznego na wartości gęstości elektronowej oraz efektywnej liczby atomowej Z. W artykule zaprezentowano proces kalibracji z wykorzystaniem wzorcowych minerałów. Wyliczone z analizy obrazów wartości próbek wzorcowych, porównano z wartościami wyznaczonymi metodami laboratoryjnymi. Przykład zastosowania wyników przedstawiono na przebadanym fragmencie obrazu rdzenia piaskowca, zawierającego szczelinę wypełniona kalcytem.
One of the first applications of X-ray computed tomography in geology took place in 1974. X-ray tomography (CT) allows non-invasive imaging of the examined objects. The result of a tomographic measurement is a spatial image, showing the changes in X-ray absorption value for each point of the examined object, which are a result of calculations during the reconstruction process. An important advantage of computer tomographs is the ability to test large objects (meter sections of the core) in a very short time, while the disadvantage is the relatively low resolution of the measurement. Each voxel in the tomographic image has a specific grey value, proportional to the linear attenuation coefficient, depending on the electron density and the effective atomic number averaged in the imaged space (the averaging range is determined by the resolution of the tomographic image). Two tomographic images registered at two different energies, allows the deconvolution of the images into two components: the first – dependent on the electron density and the second – dependent on the effective atomic number. The aim of this study is to show the possibility of using dual energy computed tomography (DECT) to litho-density characterization of rock cores. In order to use tomographic images to obtain the above-mentioned physicochemical values, it is necessary to standardize CT images. The paper presents the process of determining calibration coefficients, which are necessary to convert the values of absorption coefficients, which are a direct result of CT reconstruction, into density values and effective Z atomic number. The article presents the calibration process with the use of reference rock fragments. The values of the standard samples computed from the analysis of images were compared with the values determined by laboratory methods. An example of the application of results is presented on the examined part of the image of the sandstone core, containing a calcite-filled fracture.
Źródło:
Nafta-Gaz; 2019, 75, 2; 83-88
0867-8871
Pojawia się w:
Nafta-Gaz
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Concentration of some amino acids in blood plasma and study results of lumbosacral bone system computer tomography
Autorzy:
Wójcik, G.
Sokołowska, B.
Borzecki, A.
Powiązania:
https://bibliotekanauki.pl/articles/2052367.pdf
Data publikacji:
2015
Wydawca:
Akademia Bialska Nauk Stosowanych im. Jana Pawła II w Białej Podlaskiej
Tematy:
amino acids
chromatography
computed tomography
lumbar spine
Opis:
Introduction and objective: Back pain are the most common ailment within the human locomotor system. Because of their prevalence, they were classified as diseases of civilization. The aim of the study was to attempt to assess the concentration of selected amino acids in plasma and correlating the results of laboratory tests with the occurrence of backaches. Material and method: The study group included 188 patients presenting for CT scan administering as the cause of their symptoms low back pains. All of these patients gave the blood samples from which the concentration of free amino acids was estimated by ion exchange chromatography using an automated amino acid analyzer AAA 400 from INGOS Praha. The control group consisted of patients who underwent testing using computed tomography and there were no primary or secondary changes associated with degeneration in the lumbar spine. Results: Patients on the basis of research carried out by computed tomography were divided into five groups according to disease entity. Analyzing the average concentration of essential amino acids in the blood plasma of patients of each group, it was found that it is higher in the case of lysine for each considered disease entity. The average concentration of methionine in all disease entities does not deviate from the average values in the control group. Analysis of the average concentration of selected essential amino acids revealed that in the case presented disorders underwent their level of variation. Average concentrations of selected amino acids have proven to be very similar in both groups. Slightly higher values proved to be in the control group for proline and lysine. Conclusions: The concentration of amino acids varies with the severity of degenerative changes in the connections as well as in interbody joints. The highest increase in the concentrations of all tested amino acids are present in root bands. Decrease in the concentrations of all tested amino acids appears in cancer.
Źródło:
Health Problems of Civilization; 2015, 09, 3; 5-11
2353-6942
2354-0265
Pojawia się w:
Health Problems of Civilization
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The evaluation of microporosity and mechanical properties in high strength aluminum alloys with the use of numerical analysis and computed tomography
Autorzy:
Pysz, S.
Żuczek, R.
Małysza, M.
Czekaj, E.
Tchórz, A.
Powiązania:
https://bibliotekanauki.pl/articles/391815.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Odlewnictwa
Tematy:
AlZnMgCu alloy
microporosity
mechanical properties
computed tomography
Opis:
One of the aspects of sustainable development is the reduction of the concentration of CO2 in the atmosphere. This could be achieved for example by the reduction of fuel consumption. That is why the research for the new construction and material solutions regarding the reduction of the weight of vehicles is so important. Alongside weight reduction of different kinds of vehicles, there is also the possibility of the application of alternative propulsion systems. The lower total vehicle weight allows to extend the lifetime of the batteries with the reduction of recharge cycles. The use of the aluminum base AlZnMgCu as cast alloy which is known as 7xxx series plastic forming alloy, allows to significantly reduce the weight of the components manufactured as cast structures, ensuring high strength properties. The wide range of the solidification temperature, which is more than 150°C, characterizes this alloy with a high tendency to create micro and macro porosity. The study presents the relationship between the cooling rate and the area of occurrence and percentage of microporosity. Obtained results were linked to the local tensile strength predicted in the simulation analysis. The evaluation of the microporosity was performed on the basis of the CT (computed tomography) and the analysis of the alloy microstructure. The microstructure analysis was carried out on a test specimen obtained from the varying wall thickness of the experimental casting. The evaluation of the mechanical properties was conducted on the basis of the static tensile test.
Źródło:
Prace Instytutu Odlewnictwa; 2017, 57, 4; 297-302
1899-2439
Pojawia się w:
Prace Instytutu Odlewnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A practical statistical approach to the reconstruction problem using a single slice rebinning method
Autorzy:
Cierniak, Robert
Pluta, Piotr
Kaźmierczak, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/1837534.pdf
Data publikacji:
2020
Wydawca:
Społeczna Akademia Nauk w Łodzi. Polskie Towarzystwo Sieci Neuronowych
Tematy:
reconstruction algorithm
statistical iterative method
computed tomography
Opis:
The paper presented here describes a new practical approach to the reconstruction problem applied to 3D spiral x-ray tomography. The concept we propose is based on a continuous-to-continuous data model, and the reconstruction problem is formulated as a shift invariant system. This original reconstruction method is formulated taking into consideration the statistical properties of signals obtained by the 3D geometry of a CT scanner. It belongs to the class of nutating reconstruction methods and is based on the advanced single slice rebinning (ASSR) methodology. The concept shown here significantly improves the quality of the images obtained after reconstruction and decreases the complexity of the reconstruction problem in comparison with other approaches. Computer simulations have been performed, which prove that the reconstruction algorithm described here does indeed significantly outperforms conventional analytical methods in the quality of the images obtained.
Źródło:
Journal of Artificial Intelligence and Soft Computing Research; 2020, 10, 2; 137-149
2083-2567
2449-6499
Pojawia się w:
Journal of Artificial Intelligence and Soft Computing Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Correlation between the extent of pneumatization of Agger agger Nasi nasi cells and the anterior-to-posterior length of the frontal recess: A a computer-assisted anatomical study.
Autorzy:
Altıntaş, Ahmet
Çelik, Mustafa
Yegin, Yakup
Canpolat, Sinan
Olgun, Burak
Tülin Kayhan,, Fatma
Powiązania:
https://bibliotekanauki.pl/articles/1398553.pdf
Data publikacji:
2017
Wydawca:
Index Copernicus International
Tematy:
pneumatization
agger nasi
frontal recess
computed tomography
Opis:
Objectives: To explore the correlation between the volume of the aAgger nNasi (AN) cell bulge and the A-P length of the frontal recess (FR). Subjects and methods: In total, 120 patients, who underwent septoplasty, were included. All patients underwent preoperative paranasal sinus computed tomography of the paranasal sinuses (PNS CT) imaging. In total, CT data on of all 120 PNSs patients were analyzed in terms of thewith respect to the extent of pneumatization of the AN cell bulge and the A-P dimensions of the FR. Each side was analyzed separately. Results: We included 120 patients,: 78 (65.0%) females and 42 (35.0 %) males. Their average age was 33.7 ± 11.6 years (range: 18–65 years). The mean volume of the AN cell bulge was 0.26 ± 0.4 mm3 on both the right and left sides. The A-P length of the FR was 7.7 ± 2.2 mm. No significant between-side difference in the mean volume of the AN cell bulge was apparent observed (p=0.906). This volume did not differ significantly by age or sex (p=0.844 and p=0.971, respectively). We found no correlation between the volume of the AN cell bulge and the A-P length of the FR (r = 0.098, p=0.192). Conclusion: In the present study, no correlation between AN cell volume and the A-P length of the FR was found. When studying the anatomical complexity of the FR, it is essential to consider the AN cell volume. We suggest that preoperative CT imaging is critical when endoscopic sinus surgery is planned. However, further studies with larger numbers of patients are needed to explore the relationship between AN cell pneumatization and the anatomy of the FR.
Źródło:
Polish Journal of Otolaryngology; 2017, 71, 3; 48-52
0030-6657
2300-8423
Pojawia się w:
Polish Journal of Otolaryngology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Verification of the Computed Tomography Results of Aluminum Alloy Welded Joint
Autorzy:
Malicki, M.
Sobczak, K.
Powiązania:
https://bibliotekanauki.pl/articles/97855.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Tematy:
computed tomography
CT
welded joints
defects
microcracks
Opis:
Computed tomography (CT) of aluminum welded joint specimen has been performed. On the tomographic cross sections some defects have been found. To verify them the metallography cross sections of welded has been done. It was found that selected defects are micro cracks.
Źródło:
Fatigue of Aircraft Structures; 2018, 10; 47-52
2081-7738
2300-7591
Pojawia się w:
Fatigue of Aircraft Structures
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CT negative subarachnoid hemorrhage in emergency department
Autorzy:
Szypenbejl, Jacek
Siemiński, Mariusz
Szurowska, Edyta
Szmuda, Tomasz
Basiński, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/895725.pdf
Data publikacji:
2020-05-29
Wydawca:
Gdański Uniwersytet Medyczny
Tematy:
emergency department
computed tomography
cerebral aneurysm
subarachnoid hemorrhage
Opis:
Background: Subarachnoid hemorrhage (SAH) is rare but potentially life-threatening cause of acute headache. First diagnostic test performed in the Emergency Department (ED) for acute “thunderclap” headache is computed tomography of the head (CT) without contrast enhancement. Negative non-contrast head CT may be erroneously interpreted as an exclusion of SAH and lead to ED discharge. The consequences of overlooking SAH are of special interest to the Emergency Physician. The aim of this study was to assess prevalence and clinical picture of CT-negative cases of SAH admitted to the ED. Material and methods: Retrospective analysis of charts of patients admitted to the ED and diagnosed with SAH during 18 consecutive months. Results: Our data gives information about clinical picture of patients with CT-negative SAH and their further clinical course. Out of 126 patients diagnosed with SAH, 5 (4.0%) were diagnosed with SAH despite negative non-contrast head CT scan. All cases were diagnosed by means of lumbar puncture and analysis of cerebrospinal fluid. In all patients with CT-negative SAH computed tomographic angiography (CTA) was performed and no vascular abnormalities were found. In one case digital subtraction angiography was performed due to equivocal CTA picture and it demonstrated small unruptured aneurysm of the medial cerebral artery. All patients with CT-negative SAH were admitted to a neurological ward and later discharged from the hospital without neurological deficit. There were no episodes of clinical deterioration and none of the patients required an urgent neurosurgical intervention. Conclusions: Although lumbar puncture remains a gold standard in exclusion of SAH, head CT scan without contrast enhancement appears to be a satisfying diagnostic tool in ED.
Źródło:
European Journal of Translational and Clinical Medicine; 2020, 3, 1; 43-48
2657-3148
2657-3156
Pojawia się w:
European Journal of Translational and Clinical Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Charakteryzacja porównawcza współrzędnościowej techniki pomiarowej i tomografii komputerowej
Comparative characterisation of coordinate measuring technique and computed tomography
Autorzy:
Sładek, J.
Kowalski, M.
Ryniewicz, A.
Gacek, K.
Powiązania:
https://bibliotekanauki.pl/articles/152682.pdf
Data publikacji:
2010
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
WMP
tomografia komputerowa
porównanie
CMM
computed tomography
comparison
Opis:
Niniejsze opracowanie jest związane z dwoma znacznie rozpowszechnionymi technikami pomiarowo-badawczymi o charakterze uniwersalnym, czyli takimi, które mogą być zastosowanie w różnych dziedzinach np. w technice i medycynie. Za cel przyjęto wstępne porównanie techniki współrzędnościowej z tomografią komputerową. Obydwie obecnie stosowane techniki wykorzystują zaawansowane oprogramowanie, ale działają wg zupełnie różnych zasad. W pracy opisano schematy strukturalne działania obu urządzeń , wektory oddziaływań pól pomiarowych i ich cechy charakterystyczne co do układów współrzędnych. Te cechy zostały odniesione do oceny odwzorowania kształtu powierzchni z regularnymi wgłębieniami. Przeprowadzono badania wstępne oraz zamieszczono przykładowe rezultaty pomiarów w postaci graficznej. Dla głównych kryteriów metrologicznych sporządzono porównanie cech w formie tabelarycznej i sformułowano wnioski z zaakcentowaniem zastosowań medycznych. W przypadku zastosowania TK ocena liczbowa odstępstw od kształtu nominalnego odbywa się zasadniczo na drodze porównawczej i jest wyraźnie mnie precyzyjna od oceny metodą współrzędnościową ale dla zastosowań medycznych wystarczająca.
This study is connected with two much prevalent measurement and testing techniques of a universal character, namely those that can be applied to various fields such as engineering and medicine. The aim is the initial comparison of coordinate techniques with computer tomography. These two techniques use advanced software, but operate on entirely different principles. The paper describes structural diagrams of two devices: Coordinate Measuring Machines and Computer Tomography, vectors of measurement fields impacts and their characteristics as a coordinate system. These features were related to the assessment of surface mapping of a spherical shape. Preliminary studies were conducted, and examples of measuring results in graphic form were provided. For the main metrological criteria the comparison of the characteristics in tabular form was made and the conclusions with emphasis on medical applications were formulated. In the case of Computer Tomography, the numerical evaluation of deviations from the nominal shape is primarily performed through the compari-son and is clearly less precise than the evaluation with coordinate method but is sufficient for medical applications.
Źródło:
Pomiary Automatyka Kontrola; 2010, R. 56, nr 8, 8; 942-945
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Biometrological Procedure Preceeding the Resurfacing
Autorzy:
Ryniewicz, A. M.
Madej, T.
Ryniewicz, A.
Bojko, Ł.
Powiązania:
https://bibliotekanauki.pl/articles/221556.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cox-arthrosis
resurfacing
modelling
bio-metrology
computed tomography
Opis:
This paper presents a preoperative hip reconstruction method with diagnosed osteoarthritis using Durom Hip Resurfacing System (DHRS). The method is based on selection and application of the resurfacing to the pelvis reconstructed on the basis of computed tomography. Quality and geometrical parameters of distinguished tissues have a fundamental significance for locating and positioning the acetabular and femoral components. The application precedes the measurements of anatomical structures on a complex numerical model. The developed procedure enables functional selection of endo-prosthesis and its positioning in such a way that it secures geometric parameters within the bone bed and the depth , inclination angles and ante-version of the acetabular component, the neck-shaft angle and ante-torsion angle of the neck of the femoral bone, and reconstruction of the biomechanical axis of the limb and the physiological point of rotation in the implanted joint. Proper biomechanics of the bone-joint complex of the lower limb is determined by correlation of anatomical-geometrical parameters of the acetabular component and parameters of the femoral bone.
Źródło:
Metrology and Measurement Systems; 2016, 23, 1; 97-106
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and Numerical Study of NACA and Conventional Riveting Procedure
Autorzy:
Wronicz, W.
Kaniowski, J.
Malicki, M.
Kucio, P.
Klewicki, R.
Powiązania:
https://bibliotekanauki.pl/articles/97783.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Tematy:
rivet
NACA riveting
fatigue
hole expansion
computed tomography
Opis:
Fatigue behaviour is one of the most important properties of modern airplanes and rivets influence it strongly. According to the literature, the NACA riveting offers a multiple increase in the fatigue life of joints. The aim of this paper is to investigate the benefits offered by the NACA riveting procedure with respect to the residual stress and strain distribution after riveting as well as rivet hole expansion. Experimental and numerical approaches were adopted. The conventional riveting with both the universal and countersunk rivets was compared with the NACA riveting. The countersunk angle and depth in the case of the NACA riveting was modified somewhat relative to the values met in the literature. For these three cases, strain gauge measurements during riveting, hole expansion measurements and FE calculations were performed. The hole expansion measurement with the use of Computer Tomography(CT) was proposed. Only the FE calculations unambiguously indicate better fatigue properties of the NACA riveting. The proposed method of hole expansion measurement requires further research to increase its accuracy.
Źródło:
Fatigue of Aircraft Structures; 2017, 9; 157-170
2081-7738
2300-7591
Pojawia się w:
Fatigue of Aircraft Structures
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microstructural and tomographic analyses in geotechnical assessment of soil media
Autorzy:
Kumor, M. K
Powiązania:
https://bibliotekanauki.pl/articles/178954.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
clay soils
organics soil composition
microstructure
computed tomography
Opis:
This paper discusses two different approaches to microanalysis of the soil medium. It presents testing results collected by electromicroscopy, which requires special sample preparation, and a non-destructive method, requiring no sample preparation and using a computer-assisted tomograph. The paper presents: • Applicability of microstructure analyses and chemical microanalysis in the determination of structural damage incurred in the historical time in relation to the effect of contemporary abiotic events; • Application of a standard medical computer-assisted tomograph in qualitative assessment of structure and observations of mechanisms of failure in the cement/peat soil composite. Investigations concerning the applicability of computed tomography in soil micromechanics are demonstrative in character and the presented conclusions suggest further directions for research.
Źródło:
Studia Geotechnica et Mechanica; 2014, 36, 3; 57-66
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance analysis of regularization algorithms used for image reconstruction in computed tomography
Autorzy:
Wysoczański, D.
Mroczka, J.
Polak, A. G.
Powiązania:
https://bibliotekanauki.pl/articles/201356.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
computed tomography
image reconstruction
algebraic approach
regularization methods
Opis:
Computed tomography is one of the most significant diagnostic techniques in medicine. This work is focused on hard-field imaging, where signals take a form of straight rays and the reconstructed image can be presented as a matrix with unknown pixels. Algebraic methods for direct computation of the image have not been used in practice because of the scale of the problem and numerical errors appearing in the solution. The aim of this work was to analyse the performance of direct algebraic algorithms for tomographic image reconstruction including regularisation mechanism such as: generalised regularisation, Tikhonov regularisation, Twomey regularisation and ridge regression (RR), as well as comparing the results with the filtered backprojection (FBP) as the reference method. The performed analyses demonstrated that the regularised algebraic methods are more accurate than the commonly used FBP, and RR appeared the most precise among them. Additionally it was shown that the invariant system matrix (inverted during calculations) can be easily determined by solving the forward problem. Finally, potential directions of further research have been pointed out.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2013, 61, 2; 467-474
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 97

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies