Temat: gęstość mineralna - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Degree of mineralisation of bones in children with idiopathic scoliosis. Do these children show a reduced bone mineral density?
Stopień mineralizacji kości dzieci ze skoliozą idiopatyczną. Czy występuje u nich obniżona gęstość mineralna kości?
Autorzy:: Deja, Agata
Nowacka-Pikuła, Danuta
Powiązania:: https://bibliotekanauki.pl/articles/1798804.pdf
Data publikacji:: 2015
Wydawca:: Akademia Wychowania Fizycznego im. Bronisława Czecha w Krakowie
Tematy:: Scoliosis
bone mineral density
Osteoporosis
Densitometry
skolioza
gęstość mineralna kości
osteoporoza
densytometria
Opis:: Introduction: Idiopathic scoliosis constitutes a serious clinical problem due to the risk of progression, trunk deformation and possible respiratory disorders. The relation between the bone mineral density (BMD) and the risk of scoliosis developing in children is still unclear. However, confirmation of such a relation could result in both modifications of the current treatment and an earlier rehabilitation in children with decreased bone mineral density. Aim: The aim of the study was to assess the BMD in children with idiopathic scoliosis, in accordance with the guidelines of the International Society of Clinical Densitometry (ISCD). Materials and methods: a total of 57 children with idiopathic scoliosis aged 5.5 to 18.0 years took part in the study. Anteroposterior (AP) radiographs were taken to determine the Cobb angles. Also, the trunk axial rotation angles according to Bunnell were evaluated using Adam’s test with a scoliometer. The densitometric examinations of the L1-L4 spine were performed using a densitometer, based on Dual-energy X-ray absorptiometry (DEXA). Results: Among the 57 patients with scoliosis, a Z-score equal or below – 2.0 SD occurred in 5 of the examined children (9%). a statistically significant correlation between the BMD and the spine angle, and between the Z-score value and the spine angle, was not observed. Conclusions: Our study indicates that a decreased bone mineral density is not observed in the population of children with scoliosis. The densitometric examination of the children with scoliosis is difficult to interpret, due to their continuous skeletal grow and the great differences in bone size between individuals of the same age, as well as rotations of the analysed vertebrae, and the limited growth due to scoliosis.
Wstęp: Skolioza idiopatyczna jest trójpłaszczyznową deformacją kręgosłupa o nieznanej etiologii. Stanowi ona u dzieci poważny problem kliniczny z uwagi na możliwość jej progresji, deformacji tułowia oraz możliwych zaburzeń oddychania. Wciąż nie jest do końca jasny związek między mineralizacją kości a ryzykiem rozwoju skoliozy u dzieci. Potwierdzenie takiej korelacji mogłoby przyczynić się zarówno do zmiany dotychczasowego leczenia, jak również do wczesnej interwencji rehabilitacyjnej dzieci z obniżoną gęstością kości. Cel pracy: Celem pracy była ocena gęstości mineralnej kości u dzieci ze skoliozą idiopatyczną, zgodnie z wytycznymi Międzynarodowego Towarzystwa Densytometrii Klinicznej (ISCD). Materiał i metody: 57 dzieci ze skoliozą idiopatyczną w wieku od 5,5 do 18 lat. Kąt skoliozy wyznaczano na zdjęciu rtg kręgosłupa metodą Cobba. Kąt rotacji tułowia wg Bunnella oceniano w teście Adamsa za pomocą skoliometru. Badania densytometryczne kręgosłupa L1-L4 wykonano za pomocą densytometru, opartego o metodę absorpcjometrii promieniowania rentgenowskiego o podwójnej energii (DEXA). Wyniki: Spośród 57 pacjentów ze skoliozą Z-score równy lub poniżej – 2,0 SD występował u 5 badanych dzieci (9%). Nie zaobserwowano statystycznie istotnej korelacji między gęstością mineralną kości a skrzywieniem kręgosłupa, jak również między wartością Z-score a skrzywieniem kręgosłupa. Wnioski: Nasze badania wskazują, że u dzieci ze skoliozą nie obserwuje się obniżonej gęstości mineralnej kości. Badanie densytometryczne u dzieci ze skoliozą jest trudne do interpretacji, ponieważ obok czynników związanych z ciągłym procesem rośnięcia szkieletu i dużymi różnicami międzyosobniczymi w rozmiarze kości u dzieci w tym samym wieku, na wynik wpływają też czynniki związane ze skoliozą, tj. rotacja kręgu w miejscu pomiaru oraz deficyt wzrostu związany ze skrzywieniem kręgosłupa.
Źródło:: Medical Rehabilitation; 2015, 19(2); 5-9
1427-9622
1896-3250
Pojawia się w:: Medical Rehabilitation
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 2.

Tytuł:: Thyroid hormone and thyreotropin (TSH) association with densitometric parameters in children
Autorzy:: Porwik, E.
Matusik, P.
Drzyzdzyk, K.
Powiązania:: https://bibliotekanauki.pl/articles/333097.pdf
Data publikacji:: 2009
Wydawca:: Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:: tyreotropina
hormon tarczycy
densytometria
gęstość mineralna kości
dzieci
thyrotropin
thyroid hormone
densitometry
bone mineral density
children
Opis:: The influence of TSH on bones is still vastly unknown and the information that is known is considered controversial. This important relationship has not been studied in detail. The aim of our research was to assess the correlation between TSH, thyroid hormone and bone mineral density in children measured by DXA scanning. Our study group included 36 children (16 girls and 20 boys) mean age 12.9 š 3.3 years. Basic anthropometrical measurements were performed (height, weight, body mass index-BMI), in all subjects. Blood was collected and measured for TSH and FT4. Bone mineral density of lumbar spine (L2-L4 BMD) and total body (Total Body BMD) were measured by DXA and expressed as bone mineral content (BMC [g]) and bone mineral density (BMD [g/cm2]). BMD Z-Score was also calculated. Correlation between the parameters obtained by DXA and anthropometrical data, TSH and thyroid hormone concentration were calculated. A statistically significant positive correlation was observed between height, weight and BMI and BMD which was calculated. Weight and BMI also had a statically significant correlation with Z-Score and total bone mineral content (BMC – expressed in grams). There was a statistically significant positive correlation between TSH level and Z-Score for both L2-L4 lumbar spine and for total body. TSH did not correlate significantly with BMD [g/cm2] and BMC [g]. FT4 was negatively and significantly correlated with Z-Score for both L2-L4 lumbar spine and for total body. There was also no significant correlation between FT4 and BMD [g/cm2] and BMC [g]. Conclusion: 1. Thyroid stimulating-hormone (TSH) appears to be associated with maintenance of bone mineral density in children. 2. BMD Z-Score especially from L2-L4 lumbar spine assessed by DXA scanning is correlated best with hormonal and biochemical factors potentially influencing bone mineralization in children.
Źródło:: Journal of Medical Informatics & Technologies; 2009, 13; 141-144
1642-6037
Pojawia się w:: Journal of Medical Informatics & Technologies
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 3.

Tytuł:: Differences in trabecular bone mechanical strength measured by the x-ray microcomputed tomography and compressive test
Autorzy:: Binkowski, M.
John, A.
Nowak, R.
Bożek, M.
Bielecki, M.
Powiązania:: https://bibliotekanauki.pl/articles/333606.pdf
Data publikacji:: 2010
Wydawca:: Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:: rentgenowska tomografia komputerowa
gęstość mineralna kości
wytrzymałość mechaniczna
x-ray microcomputed tomography
bone mineral density
mechanical strength
Opis:: The article describes the concept of measurement of the mechanical strength of trabecular bone dissected from human femoral head. When the studies are performed based on the human trabecular bone, there is a risk that correlation can be not achieved due to high discrepancy in the distribution of the bone density and mechanical properties. The compressive tests and X-ray microcomputed tomography with associated density phantom were used to deliver quantitative data. There is a conclusion that the selection of the region in the femoral head has to be performed very carefully. The region where cylinder is dissected can influence the results and produce fake data, which could not be correlated in the density of bone.
Źródło:: Journal of Medical Informatics & Technologies; 2010, 15; 163-168
1642-6037
Pojawia się w:: Journal of Medical Informatics & Technologies
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 4.

Tytuł:: The influence of osteoporotic bone structures of the pelvic-hip complex on stress distribution under impact load
Autorzy:: Arkusz, K.
Klekiel, T.
Niezgoda, T. M.
Będziński, R.
Powiązania:: https://bibliotekanauki.pl/articles/307484.pdf
Data publikacji:: 2018
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:: gęstość mineralna kości
BMD
osteoporoza
pelvic-hip complex
PHC
bone mineral density
finite element analysis
FEA
osteoporosis
Opis:: Purpose: The aim of this study was to determine the effect of bone mineral density (BMD) on the stress distribution in pelvic-hip complex (PHC) model which included bone structures and soft tissues. Bone mass changes in osteoporosis and osteopenia were considered in this analysis. In addition, the relations between force direction and stress distribution causing PHC fractures were determined. Methods: This paper presents the development and validation of a detailed 3D finite element model with high anatomical fidelity of the PHC and BMD changes in trabecular and cortical bones, modelled based on CT scans. 10 kN loading was induced on a model consisting of 8 ligaments, the pelvis, sacrum, femur in front and side directions. Results: For validation, the results of this model were compared to physiological stress in standing position and previous results with high-energy crashes under side impact load. Analysis of side-impact indicated the influence of BMD on femoral neck fractures, acetabular cartilage and sacroiliac joint delaminations. Front-impact analysis revealed the inferior pubic ramus, femoral neck fractures and soft tissue injuries, i.e., acetabular cartilage and symphysis pubis in osteoporosis and osteopenia. Conclusions: The elaborated PHC model enables effective prediction of pelvis injuries in high-energy trauma, according to Young-Burgess classification, and the determination of the influence of BMD reduction on pelvis trauma depending on force direction. The correlation between BMD and stress distribution causing varying injuries was determined.
Źródło:: Acta of Bioengineering and Biomechanics; 2018, 20, 1; 29-38
1509-409X
2450-6303
Pojawia się w:: Acta of Bioengineering and Biomechanics
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 5.

Tytuł:: Relationship between the mineral content of human trabecular bone and selected parameters determined from fatigue test at stepwise-increasing amplitude
Autorzy:: Mazurkiewicz, A. J.
Topoliński, T.
Powiązania:: https://bibliotekanauki.pl/articles/306367.pdf
Data publikacji:: 2017
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:: gęstość mineralna kości
kość beleczkowa
test wytrzymałości
bone mineral density
trabecular bone
fatigue test
stepwise load
ash density
Opis:: Purpose: The study aimed to investigate a relationship between the mineral content of the human trabecular bone and parameters determined from compression fatigue tests at stepwiseincreasing amplitude. Methods: Mineral content of the trabecular bone was estimated as ash density and bone mineral density values. The relationship between the ash density, bone mineral density and factors obtained from fatigue test: fatigue life, cumulative elastic energy and cumulative energy of dissipation was determined. Results: The results from the measurements of ash density and bone mineral density show good correlation with the fatigue test results. The relationship was estimated based on the correlation coefficient R within 0.74-0.79 for the particular pairs of factors. Conclusions: The study shows that the ash density and the bone mineral density are good predictors to estimate the fatigue life of trabecular bone. The study also validates the applicability of the tests at stepwise-increasing amplitude in determining the mechanical properties of trabecular bone.
Źródło:: Acta of Bioengineering and Biomechanics; 2017, 19, 3; 19-26
1509-409X
2450-6303
Pojawia się w:: Acta of Bioengineering and Biomechanics
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 6.

Tytuł:: Simulation of the reaction of X-ray radiation with an object while densitometry tests
Autorzy:: Binkowski, M.
Dyszkiewicz, A.
Wróbel, Z.
Powiązania:: https://bibliotekanauki.pl/articles/333342.pdf
Data publikacji:: 2004
Wydawca:: Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:: badanie densytometryczne
tkanka kostna
gęstość mineralna kości
densitometry test
bone tissue
bone mineral density
simulation of absorption law
Opis:: The computer modelling of absorption effect of X-ray radiation in the bone tissue was analysed. An image, which is produced as a result of X-ray absorption was computed based on the absorption law. The simulation enables to define dimensions and resolution of space where the experiment will be realised. A model of a sample contains information about its geometry and distribution of density. It can be made as simple solids or loaded from external source, like files. This method may be useful to load information about bone microstructure into the simulation space. A source of X-ray radiation was defined as a plate, which has initial radiation intensity. Rules of radiation propagation were simplified to straight model where radiation propagates in the direction perpendicular to the surface of detector which records an image. The image is generated by computation of partial absorption for each space elements. The results of simulation of model of micro-structure of bone tissue are presented. They can be useful to show when densitometry test does not contain accurate and full information about bone tissue. It may by helpful in the future while searching for reasons of incomplete correlation between mineral density and mechanical strength.
Źródło:: Journal of Medical Informatics & Technologies; 2004, 8; MM95-104
1642-6037
Pojawia się w:: Journal of Medical Informatics & Technologies
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 7.

Tytuł:: Evaluation of bone mineral density of students from the Pope John Paul II State School of Higher Education in Biała Podlaska
Ocena gęstości mineralnej kości studentów Państwowej Szkoły Wyższej im.Papieża Jana Pawła II w Białej Podlaskiej
Autorzy:: Bertrandt, J.
Kłos, A.
Stankiewicz, W.
Pańczuk, A.
Powiązania:: https://bibliotekanauki.pl/articles/2052133.pdf
Data publikacji:: 2016
Wydawca:: Akademia Bialska Nauk Stosowanych im. Jana Pawła II w Białej Podlaskiej
Tematy:: bone mineral density
osteopenia
osteoporosis
source of calcium in the diet
gęstość mineralna kości
osteoporoza
źródła wapnia w diecie
Opis:: Background. Nutritional status is one of the factors enabling prediction the possibility of emergence and development of civilization diseases. Correct mineral nutritional status is important and particularly proper bones calcification. The aim of the work was to assess bone mineral density of female and male students from the Pope John Paul II State School of Higher Education in Biała Podlaska. Consumption of products which are the main source of calcium in the students’ diet was assessed as well. Material and methods. Bone mineral density was measured by densitometry method. The consumption of food that are sources of calcium in students’ diet was assessed by questionnaire. Results. In groups of women, changes characteristic of osteopenia were showed among 54.9 % women to 25 years and 67.6 % in the older group. Changes characteristic of osteoporosis were found too. In the group of men aged up to 25 changes typical of osteopenia revealed 62.3% and characteristic of osteoporosis 6.6% of examined students. Among 9 older students changes typical of osteopenia were found among 44.4%. Dairy products were main source of calcium in students’ daily food rations. Conclusions. There is a need to take action in the field of nutritional health education, including the practical application of knowledge in the prevention of osteopenia and osteoporosis , addressed to young people. Students from the Pope John Paul II State School of Higher Education in Biała Podlaska should be included in the program of nutrition education program for the prevention of osteoporosis.
Wprowadzenie. Stan odżywienia jest jednym z czynników umożliwiających możliwość prognozowania powstania i rozwoju chorób cywilizacyjnych. Ważny jest prawidłowy stan odżywienia mineralnego, a szczególnie prawidłowe uwapnienie kości. Celem pracy była ocena gęstości mineralnej kości studentek i studentów Państwowej Szkoły Wyższej im. Papieża Jana Pawła II w Białej Podlaskiej. Oceniono także ilość produktów spożywanych przez studentów, będących podstawowym źródłem wapnia w ich diecie. Materiał i metody. Uwapnienie kości mierzono metodą densytometryczną na kości przedramienia, przy użyciu aparatu EXA 3000. Konsumpcja produktów spożywczych będących źródłem wapnia w diecie studentów oceniana była metodą ankietową. Wyniki. W obydwu badanych grupach duży odsetek kobiet wykazywał zmiany charakterystyczne dla osteopenii – 54,9% u kobiet do 25 lat i 67,6% w grupie starszych studentek. Wykazano także zmiany charakterystyczne dla osteoporozy. W grupie mężczyzn do 25 lat zmiany typowe dla osteopenii miało 62,3%, a dla osteoporozy 6,6%. Wśród 9 starszych studentów zamiany w uwapnieniu wskazujące na osteopenię miało 44,4% badanych. Produkty mleczne są głównym źródłem wapnia w całodziennych racjach pokarmowych studentów. Wnioski. Istnieje potrzeba podejmowania działań w zakresie żywieniowej oświaty zdrowotnej, obejmujących praktyczne wykorzystanie wiedzy w profilaktyce osteopenii i osteoporozy, skierowanych do osób młodych. Studenci z Państwowej Szkoły Wyższej w Białej Podlaskiej powinni być objęci programem edukacji żywieniowej w zakresie profilaktyki osteoporozy.
Źródło:: Health Problems of Civilization; 2016, 10, 4; 7-13
2353-6942
2354-0265
Pojawia się w:: Health Problems of Civilization
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 8.

Tytuł:: Drilling resistance : A method to investigate bone quality
Autorzy:: Lughmani, W. A.
Farukh, F.
Bouazza-Marouf, K.
Ali, H.
Powiązania:: https://bibliotekanauki.pl/articles/306405.pdf
Data publikacji:: 2017
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:: chirurgia ortopedyczna
wiercenie
gęstość mineralna kości
jakość kości
bone drilling
orthopaedic surgery
screw pull-out strength
bone mineral density
bone quality
Opis:: Purpose: Bone drilling is a major part of orthopaedic surgery performed during the internal fixation of fractured bones. At present, information related to drilling force, drilling torque, rate of drill-bit penetration and drill-bit rotational speed is not available to orthopaedic surgeons, clinicians and researchers as bone drilling is performed manually. Methods: This study demonstrates that bone drilling force data if recorded in-vivo, during the repair of bone fractures, can provide information about the quality of the bone. To understand the variability and anisotropic behaviour of cortical bone tissue, specimens cut from three anatomic positions of pig and bovine were investigated at the same drilling speed and feed rate. Results: The experimental results showed that the drilling force does not only vary from one animal bone to another, but also vary within the same bone due to its changing microstructure. Drilling force does not give a direct indication of bone quality; therefore it has been correlated with screw pull-out force to provide a realistic estimation of the bone quality. A significantly high value of correlation (r 2 = 0.93 for pig bones and r 2 = 0.88 for bovine bones) between maximum drilling force and normalised screw pull-out strength was found. Conclusions: The results show that drilling data can be used to indicate bone quality during orthopaedic surgery.
Źródło:: Acta of Bioengineering and Biomechanics; 2017, 19, 1; 55-62
1509-409X
2450-6303
Pojawia się w:: Acta of Bioengineering and Biomechanics
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 9.

Tytuł:: The influence of bone tissue microstructure parameters on bone mineral density parameter computed within the computer simulation process
Autorzy:: Binkowski, M.
Dyszkiewicz, A.
Wróbel, Z.
Powiązania:: https://bibliotekanauki.pl/articles/333857.pdf
Data publikacji:: 2005
Wydawca:: Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:: badanie densytometryczne
tkanka kostna
gęstość mineralna kości
mikrostruktury kości
densitometry test
bone tissue
bone mineral density
bone microstructure
simulation of attenuation law
Opis:: The given article was created with reference to lack of correlation between results from densitometry test of bone tissue and its mechanical strength. The changes of bone mechanical strength cannot be solely connected with changes of bone mineral density with micro structural construction of bone tissue. The article describes the research using a computer simulation where changes of physical density and parameters of bone microstructure were modelled. The influences of those parameters for changing the bone mineral density have been computed. It has been calculated during simulation process similar to the way it has been provided from densitometry test. The computation process has been carried out on the basis of computer method of simulation of x-ray radiation propagating through the object and had been was created and tested in the previous research. The model of tested object was defined by spatial high resolution distribution of density. The simulation was executed on a sample of bone tissue. The input data to the model of sample were series of cross-sections obtained previously from micro CT of an animal sample. The changes of parameters were simulated in the model based on a method of 2D image processing. The procedure was used to reduce the trabecular surface for all cross-sections. The results of the algorithm were measured during algorithm process. Images were also analyzed by software to measure parameters of microstructure. It gave a chance to estimate the correlation between measured parameter and parameters of microstructure. The applied method of simulation of attenuation of x-ray radiation allowed to produce densitometry image and to compute parameter similar to bone mineral density. The analysis of obtained results shows how the bone mineral density computed from simulation depends on changes of parameters of microstructure.
Źródło:: Journal of Medical Informatics & Technologies; 2005, 9; 49-55
1642-6037
Pojawia się w:: Journal of Medical Informatics & Technologies
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 10.

Tytuł:: Heavy-mineral analysis in Polish investigations of Quaternary deposits: a review
Autorzy:: Marcinkowski, Bogusław
Mycielska-Dowgiałło, Elżbieta
Powiązania:: https://bibliotekanauki.pl/articles/94664.pdf
Data publikacji:: 2013
Wydawca:: Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:: heavy mineral analysis
heavy mineral resistance
heavy mineral habit
heavy mineral density
Polska
analiza ciężkich minerałów
odporność ciężkich minerałów
gęstość mineralna
Polska
Opis:: The composition of heavy-mineral assemblages is one of the main textural features of sediments because they can have significant value for the interpretation of, among others, their depositional environment, their depositional processes, and their stratigraphic position. Distinctive features of heavy minerals include their resistance to chemical weathering and mechanical abrasion, their habit, and their density. These parameters are the most widely used in the heavy-mineral research of Quaternary deposits in Poland, as well as in such research in other countries conducted by Polish scientists. Several other heavy-mineral parameters can also be used in various types of interpretation. It is discussed whether heavy-mineral analysis is decisive in the evaluation of deposits or whether it plays mainly a role that may support evidence obtained by other types of analysis. The attention is mainly devoted to transparent heavy minerals; the significance of opaque heavy minerals for interpretational purposes is only mentioned.
Źródło:: Geologos; 2013, 19, No. 1-2; 5-23
1426-8981
2080-6574
Pojawia się w:: Geologos
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 11.

Tytuł:: Comparison of two interpolation methods for empirical mode decomposition based evaluation of radiographic femur bone images
Autorzy:: Udhayakumar, G.
Sujatha, C. M.
Ramakrishnan, S.
Powiązania:: https://bibliotekanauki.pl/articles/306313.pdf
Data publikacji:: 2013
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:: anisotropy
bone mineral density
hierarchical b-spline
intrinsic mode function
radial basis function multiquadratic
trabecular soft bone
texture analysis
anizotropia
gęstość mineralna kości
analiza tekstury
Opis:: Analysis of bone strength in radiographic images is an important component of estimation of bone quality in diseases such as osteoporosis. Conventional radiographic femur bone images are used to analyze its architecture using bi-dimensional empirical mode decomposition method. Surface interpolation of local maxima and minima points of an image is a crucial part of bi-dimensional empirical mode decomposition method and the choice of appropriate interpolation depends on specific structure of the problem. In this work, two interpolation methods of bi-dimensional empirical mode decomposition are analyzed to characterize the trabecular femur bone architecture of radiographic images. The trabecular bone regions of normal and osteoporotic femur bone images (N = 40) recorded under standard condition are used for this study. The compressive and tensile strength regions of the images are delineated using pre-processing procedures. The delineated images are decomposed into their corresponding intrinsic mode functions using interpolation methods such as Radial basis function multiquadratic and hierarchical b-spline techniques. Results show that bi-dimensional empirical mode decomposition analyses using both interpolations are able to represent architectural variations of femur bone radiographic images. As the strength of the bone depends on architectural variation in addition to bone mass, this study seems to be clinically useful.
Źródło:: Acta of Bioengineering and Biomechanics; 2013, 15, 2; 73-80
1509-409X
2450-6303
Pojawia się w:: Acta of Bioengineering and Biomechanics
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 12.

Tytuł:: The effect of air entraining admixtures and cement types on the properties of fresh mortar
Wpływ domieszki napowietrzającej i rodzaju cementu na właściwości świeżej zaprawy
Autorzy:: Piasta, W.
Marczewska, J.
Powiązania:: https://bibliotekanauki.pl/articles/402177.pdf
Data publikacji:: 2013
Wydawca:: Politechnika Świętokrzyska w Kielcach. Wydawnictwo PŚw
Tematy:: air entrainment
mineral admixtures
air content
bulk density
flow
napowietrzenie
domieszka mineralna
zawartość powietrza
gęstość objętościowa
rozpływ
Opis:: In order to explain the effect of air entraining admixture (AEA) and the type of cement on the properties of fresh mortar, the following tests were carried: bulk density, flaw and air content of 20 air entrained mortars and 20 nan air entrained mortars made of ordinary Portland cement (OPC) and blended Portland cements: blast furnace slag (BSF) - limestone powder (LP), fly ash - limestone, fly ash (FA) and (BFS) cement. It has been found that the modern anionic AEAs from the group of alkyl sulfates are much more efficient and active than traditional ones i.e. sodium abietate. It is difficult to entrain air into mortars with cement of various types to the same content of air. This requires to carry out a number of tests to determine the appropriate amounts of AEA. The air entrainment of LP cement mortar does not significantly change its flow. The air entrainment of BSF and FA cement mortars increases their workability. The lowest content of air was stated in non-air-entrained mortars with FA cement, the highest air content was observed in BFS cement mortars. According to the results the bulk density of mortars is inversely proportional to the amount of air entrained.
Źródło:: Structure and Environment; 2013, 5, 1; 11-17
2081-1500
Pojawia się w:: Structure and Environment
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Informacja

Wyszukujesz frazę "gęstość mineralna" wg kryterium: Temat

Źródło danych

Dostawca treści

Kolekcja

Rok wydania

Wydawca

Temat

Autor

Typ dokumentu

Język