Academic literature on the topic 'Three Point Bending Test'
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Journal articles on the topic "Three Point Bending Test"
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Tsubota, Ken-ichi, Taiji Adachi, Seiji Nishiumi, and Yoshihiro Tomita. "OS07W0402 Elastic properties of single trabeculae measured by micro-three-point bending test." Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics 2003.2 (2003): _OS07W0402. http://dx.doi.org/10.1299/jsmeatem.2003.2._os07w0402.
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Abd Malek, Nor Jihan, and Sadiq Azizi Othman. "Three-Point Bending Test for Three Different Bolt Diameters." Journal of Engineering & Technological Advances 4, no. 1 (2019): 41–53. http://dx.doi.org/10.35934/segi.v4i1.41.
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Timber is one of the oldest materials used as main structural element prior concrete and steel which have greater ability to sustain load. The greater demand for timber as construction materials, the wood engineering introduced a new timber type called Engineered Wood Product (EWP). The crucial problem in the timber structure which focuses on the structural timber connection. The load-carrying capacity of the timber connection and the failure modes can be determined according to the European Yield Model (EYM). Three-point bending test was used to determine yield moment of the fastener, My, bolt bending strength, Fyb and average R-value for three selected different bolt diameters which are 12, 16 and 20 mm. The results were obtained for comparing between three bolt diameters with F2%, F5% and Fmax respectively. The F2% for 12, 16 and 20 mm yield moment of the fastener, My was obtained 596.4, 1631.5 and 4650 kNmm accordingly while for bolt bending strength, Fyb was 2.1, 2.4 and 3.5 kN correspondingly. The F5% for 12, 16 and 20 mm yield moment of the fastener, My was obtained 631.1, 1668.3 and 4895.6 kNmm accordingly while for bolt bending strength, Fyb was 2.2, 2.4 and 3.7 kN correspondingly. The Fmax for 12, 16 and 20 mm yield moment of the fastener, My was obtained 828.2, 2290.8 and 6545.4 kNmm accordingly while for bolt bending strength, Fyb was 2.9, 3.4 and 4.9 kN correspondingly. The average R-value for 12, 16 and 20 mm bolt diameter was 0.50214, 0.42768 and 0.42038 individually. In conclusion, the percentage difference for F2% bolt bending strength, Fyb between 12 and 16 mm has raised about 14% whereas 16 and 20 mm has shown 46% increased.
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MANNOCCI, F., M. SHERRIFF, and T. WATSON. "Three-Point Bending Test of Fiber Posts." Journal of Endodontics 27, no. 12 (December 2001): 758–61. http://dx.doi.org/10.1097/00004770-200112000-00011.
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Topič, Jaroslav, Jan Bartoš, Lubomír Kopecký, Karel Šeps, Zdeněk Prošek, and Jan Trejbal. "Cement Composite Reinforced with Synthetic Fibers: Comparison of Three-Point and Four-Point Bending Test Results." Applied Mechanics and Materials 827 (February 2016): 332–35. http://dx.doi.org/10.4028/www.scientific.net/amm.827.332.
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Presented article deals with the influence of PET fiber production on the bending strength of cement-based composite when incorporated into the fresh mortar, and comparison of results of 3-point and 4-point bending test. Cement paste samples were reinforced with 2 wt. % of primary or recycled PET fibers. The bending test was performed on prismatic samples with dimension of 40 × 40 × 160 mm. It was found that samples with recycled PET fibers, compared to primary ones, exhibit a decrease in bending strength. In the case of 4-point bending tests, the samples with recycled PET fibers exhibited higher bending strength than reference samples without any fibers. However, in the case of 3-point bending tests, the samples with recycled PET fibers had lower bending strength than the reference ones. The results suggest that recycled PET fibers could be used as an alternative to reinforce cement-based composites.
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Barreto, B. C. F., L. H. A. Raposo, S. J. B. Sousa, A. G. Pereira, A. Versluis, L. Correr-Sobrinho, and C. J. Soares. "Three-point bending test parameters for dental materials evaluation." Dental Materials 28 (January 2012): e2-e3. http://dx.doi.org/10.1016/j.dental.2012.07.012.
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Zhang, Yin, and Ya-Pu Zhao. "Adhesive Contact of Nanowire in Three-Point Bending Test." Journal of Adhesion Science and Technology 25, no. 10 (January 2011): 1107–29. http://dx.doi.org/10.1163/016942410x549898.
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Mohd Ghazali, Farah Amira, and Ardiyansyah Syahrom. "Mechanical Behaviour of Cancellous bone: Compression and Three-Point Bending Test." Malaysian Journal of Fundamental and Applied Sciences 18, no. 3 (August 4, 2022): 295–303. http://dx.doi.org/10.11113/mjfas.v18n3.2274.
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The mechanical properties of cancellous bone are fundamental in providing structural support and flexibility during physical activities. Characterization of cancellous bone properties and its mechanical behaviour were found crucial as information of the elastic and failure properties of the tissue may potentially be used to study the effects of drug treatments, aging and disease at the tissue level. This study aims to present the difference of mechanical properties of cancellous bone between compressive and three-point bending loads. Cancellous bone specimens from the femoral and tibial condyles of bovines were mechanically tested using three-point bending test and compression test and correlated with morphological parameters such as bone volume fraction and porosity. From the results, significant difference of mechanical properties was found between cancellous bone specimens tested with compressive and three-point bending load. From compressive load, the maximum stress reached 4.2 MPa, whereas in three-point bending, maximum flexural stress reached 17.0 MPa. Cancellous bone strength was found to be much higher when tested with three-point bending load, although correlations with morphological parameters such as bone volume fraction (BV/TV) and porosity were found lower compared to that in compressive load. In conclusion, there are no correlation between compression and three-point bending with morphology indices (BV/TV and porosity).
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Abdullah, Shahrum, Mohd Faridz Mod Yunoh, and Azman Jalar. "Three-Point Bending Test Behaviour of a QFN Semiconductor Package." Advanced Materials Research 97-101 (March 2010): 7–10. http://dx.doi.org/10.4028/www.scientific.net/amr.97-101.7.
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This paper discusses some issues in micromechanical property of a newly developed Quad Flat No-lead (QFN) 3D stacked die package using three-point bending test approach. The relevant test methodologies were carried out in order to observe the flexural stress, strain, maximum load and deflection of the package. While performing the test, these QFN packages were positioned on the three points test bench, and the specific applied load was then applied and moved down until the package was clearly bent and broken. The related findings indicated that the maximum load was found to be at 251.52 N and the maximum deflection was obtained at 0.41 mm. The results were important for setting related testing parameters (load, stress and strain) before applying the three point cyclic bending test on the QFN stacked die package as the future work.
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Shetty, Santosh, and Tommi Reinikainen. "Three- and Four-Point Bend Testing for Electronic Packages." Journal of Electronic Packaging 125, no. 4 (December 1, 2003): 556–61. http://dx.doi.org/10.1115/1.1604158.
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This study demonstrates the application of three-point and four-point bending tests for evaluating the reliability of chip scale packages under curvature loads. A three-point bend test is conducted on 0.5-mm-pitch chip-scale packages (CSPs) mounted on FR4 (Flame Retardant) substrates. This test is simulated by using the finite element method and the results are calibrated experimentally to formulate a reliability model. A three-point bend scheme is an ideal choice for generating reliability models because multiple packages can be tested under multiple loads in a single test. This reliability model can be used to predict the durability of the packages in the real product under any printed wiring board (PWB) curvature loading conditions. A four-point bending simulation is also demonstrated on the test substrate. Four-point bending test is an ideal method for testing a larger sample size of packages under a particular predefined stress level. This paper describes the bending simulation and testing on packages in a generic sense. Due to the confidentiality of the test results, the package constructional details, material properties, and the actual test data have not been presented here.
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Qin, Tao, Kai Ren, Zhi Liu, Yan-Wei Duan, and Lei Wang. "Mechanical Characteristics and Energy Evolution of Sandstone Three-Point Bending Test." Shock and Vibration 2021 (December 8, 2021): 1–12. http://dx.doi.org/10.1155/2021/8443777.
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With the increase of underground mining depth in coal mines, the distribution of stress fields in deep mining becomes more complex, and the stress localization characteristics are obvious. In order to obtain the local mechanical properties and energy evolution of sandstone, this article is based on the three-point bending experiment and combined with the localized failure theory to explore the evolution law of stress field, deformation field, and energy field of sandstone specimen under tensile stress during the three-point bending experiment. The results show that during the three-point bending test of sandstone, with the increase of the span of the three-point bending test, the peak stress at the characteristic point shows an increasing trend, and the peak stress has obvious regional characteristics. In the vertical direction, the peak stress at the characteristic points in the upper part of the neutral layer is larger, and the peak stress at the characteristic points in the lower part of the neutral layer is smaller. In the horizontal direction, the peak stress at the characteristic points in the near field is higher, and the peak stress at the characteristic points in the middle field and the far field is smaller. The stress field and the deformation field have a good corresponding relationship. The upper far-field peak strain tends to decrease with the increase of the span, and the upper near-field peak strain first decreases and then increases with the increase of the span. The lower near-field peak strain tends to decrease and then increase with increasing span, and the lower far-field peak strain fluctuates with increasing span. The energy field is dependent on the stress field and the deformation field, showing obvious regional characteristics. The energy storage and release capacity of the upper area are higher than those of the lower area. The overall performance of the loading energy storage, rebound energy release, and crack propagation energy release in different areas can be described as far field < mid-field << near field. The near-field energy at different spans presents the characteristics of two stages. When the span is between 140 mm and 150 mm, the near-field energy shows a rapid decreasing trend, and when the span is between 150 mm and 180 mm, the near-field energy presents an obvious increasing trend.
Dissertations / Theses on the topic "Three Point Bending Test"
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Bonucchi, Nicola. "Caratterizzazione flessionale del rinforzo di pavimentazioni bituminose con interstrati sintetici." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016.
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Uno degli aspetti fondamentali della circolazione stradale è rappresentato dalla conservazione della qualità, in termini di comfort e sicurezza trasmessa all’utente, della sovrastruttura stradale. L’obiettivo della manutenzione stradale è di garantire un livello soddisfacente delle caratteristiche funzionali lungo tutto l’arco della vita utile dell’infrastruttura. Le ridotte disponibilità economiche di enti ed amministrazioni pubbliche, spingono i ricercatori ed i tecnici del settore ad individuare soluzioni tecniche e progettuali, in grado di coniugare economicità e durabilità degli interventi. Negli ultimi decenni, si è cercato di studiare l’effetto prodotto dall’eventuale inserimento di un interstrato di rinforzo all’interno della sovrastruttura. Lo studio, sviluppato e descritto nel presente documento, ha l’obiettivo di migliorare la comprensione dell’effettivo contributo che i materiali di rinforzo possono produrre all’interno degli strati legati di una pavimentazione flessibile.
Gli obiettivi dell’indagine sperimentale, descritta nel presente documento, possono essere sintetizzati in tre punti fondamentali:
- caratterizzazione flessionale di pavimentazioni bituminose con interstrati sintetici, in particolare lo scopo dell’indagine verte a quantificare il miglioramento del comportamento meccanico della pavimentazione dotata di rinforzo;
- analisi del comportamento a fessurazione della pavimentazione, rinforzata e non, con particolare attenzione nei confronti del reflective cracking;
- valutazione del collegamento tra i due strati bituminosi in presenza di interstrato sintetico.
Per raggiungere tali obiettivi sono state eseguite due serie di prove di flessione su 3 punti (3PB) e prove di taglio Leutner.
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Said, Eman. "On the deflection of s32003 stainless steel beams." Thesis, Georgia Institute of Technology, 2016. http://hdl.handle.net/1853/54918.
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Presented in this work are the results of twelve flexural tests conducted on small-scale coupons to establish the load-deflection behavior of UNS S32003 (ATI 2003®) hot-rolled duplex stainless steel flat plates. All specimens were tested as simply supported beams loaded at the midspan. Test specimens had nominal width and thickness of 1 in. and 0.25 in., respectively. Four different span lengths of 4 in., 6 in., 9 in., and 12 in. were investigated. Analysis of the results showed that the non-linear deflection behavior can be estimated reasonably well by adopting the conventional deflection equation pertaining to an assumed linear elastic material, but after replacing the modulus of elasticity with a secant modulus corresponding to the maximum tension strain resulting from the applied load.
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Longo, Francesco. "Analisi e caratterizzazione dei materiali di rinforzo nelle sovrastrutture stradali." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2016.
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Nel presente elaborato è stato studiato l'effetto prodotto dall'inserimento di interstrati di rinforzo tra strati legati di una pavimentazione. Si è realizzato un confronto tra due pavimentazioni, una rinforzata e l'altra di controllo, mediante il software di calcolo OLCRACK, aventi le medesime caratteristiche geometriche e gli stessi materiali. In questo modo è stato possibile osservare l'effetto della griglia di rinforzo nel contrastare e ritardare il fenomeno del reflective cracking.
Parallelamente è stata effettuata un'indagine sperimentale in laboratorio su travetti bi-strato rinforzati con due tipologie differenti di griglie. I risultati hanno evidenziato l'importanza del ricoprimento sulla griglia, poiché i travetti più spessi hanno dato una risposta migliore alla vita a fatica. In più è stata osservata l'importanza della resistenza a trazione della griglia nell'incremento dei cicli a rottura dei provini.
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Almaari, Firas, and Essam Aljbban. "Strain Rate Effect on Fracture Mechanical Properties of Ferritic-Pearlitic Ductile Iron." Thesis, Linnéuniversitetet, Institutionen för byggteknik (BY), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-78858.
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This study investigates the effect of strain rate on fracture properties of Ferritic-Pearlitic Ductile Iron. A series of dynamic three point bending tests, with various load application rates, are conducted on Charpy V-notch specimens, in room temperature and approximately -18 °C. The tests are performed in a custom-made fixture and during the tests, force and displacement data are recorded. A XFEM (Extended Finite Element Method) model of the test setup has been established and material data from the tests are used as input to the model. The test results show a strong dependency of the strain rate regarding the force needed for crack initiation. Moreover, it can be concluded that low temperature makes the material very brittle, even at low load application rates.
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Majeed, Moiz, and Teja Geesala Rahitya Venkata. "Characterization of thin laminate interface by using Double Cantilever Beam and End Notched Flexure tests." Thesis, Blekinge Tekniska Högskola, Institutionen för maskinteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-20852.
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This thesis is intended to identify the mode I and mode II fracture toughness to characterize the thin laminate interface by using the Double Cantilever Beam test (DCB) and End Notched Flexure test (ENF). This study’s thin laminate was Polyethylene Terephthalate and Low-Density Polyethylene (PET-LDPE), which is mostly used by packaging industries in the manufacturing of packages to store liquid food. As PET-LDPE film is very flexible and difficult to handle, DCB and ENF tests cannot be performed directly so, sheet metal (Aluminium) was used as carrier material. PET-LDPE film is placed between two aluminum plates to reduce the flexibility and perform the tests. Therefore, the Aluminium plate was also studied to find the constitutive parameters (young’s modulus (E) and mixed hardening parameters (Plastic properties)) under the tensile test and three-point bending test. From the test response, energy release rate calculation has been done for different Pre-crack lengths to validate the DCB and ENF experimental setup, study the different Pre-crack lengths, and characterize the laminate interface. Finite Element simulation (FE simulation) for those tests were carried out in AbaqusTM2020. When needed, the force versus displacement response from FE simulation was optimized against experimental response to find the required constitutive parameters (Young’s modulus, Hardening parameters, and PET-LDPE material properties). Implementing of optimization algorithm and automated simulation has been done with the help of MATLAB code. In contrast, MATLAB works as a server, and Abaqus works as a client and connected two interfaces to run the optimization. The results obtained from experiments and FE simulations were compared to the results found in the literature.
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Moliterno, Évelyn Cassileine Bento dos Santos. "Estudo do posicionamento do dispositivo de teste utilizada no ensaio de propagação estável da trinca pelo método da cunha e da influencia do tamanho de agregado nos resultados de medida de energia de fratura utilizando o método da cunha e o da barra entalhada e flexionada." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/97/97134/tde-01102013-144648/.
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Os materiais cerâmicos são utilizados pelo homem há milhares de anos e podem ser considerados os primeiros materiais utilizados na fabricação de ferramentas. Argamassas são materiais cerâmicos formados pela mistura de cimento, areia e água, são fluidos nas primeiras horas e endurecem com o tempo, ganhando resistência mecânica, já os refratários são materiais constituídos basicamente por duas partes, uma de granulometria fina denominada matriz e a outra de granulometria grosseira, chamada agregado, trabalham em altas temperaturas e muitas vezes sofrem choques térmicos. Devido a sua fragilidade, são susceptíveis a fratura catastrófica, por isso o conhecimento de seu comportamento mecânico é tão importante. Uma importante propriedade dos materiais cerâmicos é a energia de fratura e o método mais conhecido para a sua determinação é o da barra entalhada flexionada em três ou quatro pontos, porém o grande problema deste método é a relação de tamanho de agregado/área de fratura, pois como a barra apresenta, em geral, pequenas dimensões, o material pode apresentar um agregado de dimensões próximas à dimensão da área de fraturada e o resultado final pode ser fortemente afetado. Então, em 1986, Tschegg patenteou o método da cunha (wedge splitting test) que minimiza este efeito, devido à utilização de amostras com grande área de fratura. Desde então, este método vem sendo utilizado com freqüência por diversos pesquisadores no mundo. Porém não há estudos publicados que definam a posição ideal dos roletes do dispositivo de teste, levando ao uso de diferentes posições, sem que se saiba como isso pode influenciar o ensaio. Além de não existir uma definição de, a partir de que tamanho de agregado o método da barra entalhada passa a ser desaconselhável sendo necessário o uso do método da cunha. Neste trabalho analisou-se a influência da posição dos roletes e do tamanho de agregados nas medidas de energia de fratura e na carga máxima atingida no ensaio.The ceramic materials are used by humans for thousands of years and can be considerate the first materials used in the manufacture of tools. Mortar are ceramic materials made by the mixture of cement, sand and water, it is fluid in the first hours and stiffen over time, gaining mechanical strength, the refractories in turn are made basically of two phases, one of fine granulometry called matrix and another of coarse called aggregate. It works over high temperature and many times suffer thermal shock. Due to its fragility, it is susceptible to catastrophic fracture; therefore the knowledge of its mechanical behavior is so important. One of the mainly properties of ceramic materials is the fracture energy and o most knew method for its determination is of three-point bending test on notched beams, but the biggest problem of this method is the relation between aggregate size and fracture area, because as the beam has small dimensions the aggregate can have a dimension so closed of the fracture area dimension and the final result can be tightly affect. Then in 1986, Tschegg patented the wedge splitting test, which minimizes this effect, because of the use of samples with a big fracture area. Since then, this method has been used for scientists around the world. But there are no studies that define the roll position of the test device, leading to the use of different positions, without know how it can influence the test. Besides not having a definition of from what aggregate size the wedge splitting test is advisable in despite of the bending test on notched beams. In this work was analyzed the influence of the rolls positions in the wedge splitting test and of the aggregate size in the measures of fracture energy and maximum load of test.
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Bhustalimath, Sanhgarsh. "Development and verificationof a method to determine theshear properties of Hybrix core." Thesis, KTH, Lättkonstruktioner, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-290084.
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This thesis helps develop a material model for a novel Fiber Core SandwichSheet construction. A test method was used to determine the mechanicalproperties of the sandwich material. Standard three point bendingtests coupled with digital image correlation was used. Results wereextracted from the digital image data. These results supplemented thedevelopment and tuning of an FE model of the sandwich material. Conclusionswere drawn about the feasibility of the method in studying sucha material.Denna avhandling genomfördes mot utvecklingen av en homogeniseradmaterialmodell för en ny sandwich-konstruktion med fiberkärna. En testmetodanvändes för att bestämma de mekaniska egenskaperna hos sandwichmaterialet.Testmetoden involverade trepunkts i kombination meddigital bildkorrelation. Resultaten extraherades från den digitala bilddatanvid genomförande av trepunkts. Dessa resultat användes utvecklingenav en FE-modell av sandwichmaterialet. Slutsatser drogs om tillämplighetenav metoden för att studera ett sådant material.
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Kejík, Vít. "Predikce chování stříkaného betonu s využitím elastoplastického materiálového modelu." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2020. http://www.nusl.cz/ntk/nusl-409748.
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This work is focused on the application of advanced elasto-plastic material model intended for shotcrete. Spatial mathematical models of two laboratory tests are created, where this model is used. The first test is a three-point bending concrete specimen. Next, the behavior of the material is analyzed, in which input parameters are entered. Consequently, two reverse analyzes of the available data are analyzed where a match between prediction and measurement can be obtained. The second test is a modified tensile test, where is describe the material behavior in changing of input parameters. Subsequently, reverse data analysis is created, where an acceptable match between prediction and measurement is possible. In every study, the stress waveform in the fracture process zone is analyzed to more detail.
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Kolářová, Eva. "Vliv přídavku vícesměrně orientované výztuže na mechanické vlastnosti materiálu pro přípravu celkově snímatelných náhrad." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2014. http://www.nusl.cz/ntk/nusl-217087.
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Tato Diplomová práce se zabývá vlivem vyztužení na mechanické vlastnosti materiálu pro přípravu snímatelných náhrad. Pro testování byly použity tři sady vzorků: PMMA pryskyřice, PMMA pryskyřice s Dentapreg Mesh výztuží a PMMA pryskyřice vyztužena zesilující síťkou z nerezové oceli.Pro měření chování vzorků při statickém a dynamickém namáhání byl použit třibodový ohybový test a Charpy rázové kladivo. Viskoelastické vlastnostzi byly měřeny dynamicko-mechanickou analýzou (DMA). Skenovací elektronová mikroskopie (SEM) byla použita k charakterizaci lomových ploch. Během statického namáhání vzorků výztuž nehraje důležitou roli v porovnání s nevyztuženou pryskyřicí. Nicméně byl pozorován opačný trend při dymanickém namáhání, kde efekt výzruže rostl v řadě PMMA pryskyřice – síťka z nerezové oceli – Dentapreg Mesh.
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Šot, Michal. "Hodnocení napjatostního chování lepeného konstrukčního dřeva pomocí DIC analýzy." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227634.
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The work deals with issues of evaluation of the shear properties of timber structural materials, particularly CLT elements. The work contains an overview of extensive research so far presented scientific studies dealing with the characteristic shear properties of wood. In the practical part was carried out the experiment dealing with the failure mode of transverse lamellae of CLT elements that were exposed to shear stress. There were observed individual effects that this may affect the material properties. In the first part of the experiment were performed numerical models using FEM. In the second part, the test specimens were tested in three point bending. Here, attention was paid to the influence of macroscopic properties of wood on the distribution of stress cracks and shear strength, the tests were recorded using DIC system.
Books on the topic "Three Point Bending Test"
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Sygusch, Nikolai. Stochastic Approach to Rupture Probability of Short Glass Fiber Reinforced Polypropylene based on Three-Point-Bending Tests. Wiesbaden: Springer Fachmedien Wiesbaden, 2020. http://dx.doi.org/10.1007/978-3-658-27113-8.
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Standard test method for flexural properties of unreinforced and reinforced plastics and electrical insulation material by four-point bending. West Conshohocken, Pa: ASTM International, 2010.
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Sygusch, Nikolai. Stochastic Approach to Rupture Probability of Short Glass Fiber Reinforced Polypropylene based on Three-Point-Bending Tests. Springer Vieweg, 2019.
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Skiba, Grzegorz. Fizjologiczne, żywieniowe i genetyczne uwarunkowania właściwości kości rosnących świń. The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 2020. http://dx.doi.org/10.22358/mono_gs_2020.
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Bones are multifunctional passive organs of movement that supports soft tissue and directly attached muscles. They also protect internal organs and are a reserve of calcium, phosphorus and magnesium. Each bone is covered with periosteum, and the adjacent bone surfaces are covered by articular cartilage. Histologically, the bone is an organ composed of many different tissues. The main component is bone tissue (cortical and spongy) composed of a set of bone cells and intercellular substance (mineral and organic), it also contains fat, hematopoietic (bone marrow) and cartilaginous tissue. Bones are a tissue that even in adult life retains the ability to change shape and structure depending on changes in their mechanical and hormonal environment, as well as self-renewal and repair capabilities. This process is called bone turnover. The basic processes of bone turnover are: • bone modeling (incessantly changes in bone shape during individual growth) following resorption and tissue formation at various locations (e.g. bone marrow formation) to increase mass and skeletal morphology. This process occurs in the bones of growing individuals and stops after reaching puberty • bone remodeling (processes involve in maintaining bone tissue by resorbing and replacing old bone tissue with new tissue in the same place, e.g. repairing micro fractures). It is a process involving the removal and internal remodeling of existing bone and is responsible for maintaining tissue mass and architecture of mature bones. Bone turnover is regulated by two types of transformation: • osteoclastogenesis, i.e. formation of cells responsible for bone resorption • osteoblastogenesis, i.e. formation of cells responsible for bone formation (bone matrix synthesis and mineralization) Bone maturity can be defined as the completion of basic structural development and mineralization leading to maximum mass and optimal mechanical strength. The highest rate of increase in pig bone mass is observed in the first twelve weeks after birth. This period of growth is considered crucial for optimizing the growth of the skeleton of pigs, because the degree of bone mineralization in later life stages (adulthood) depends largely on the amount of bone minerals accumulated in the early stages of their growth. The development of the technique allows to determine the condition of the skeletal system (or individual bones) in living animals by methods used in human medicine, or after their slaughter. For in vivo determination of bone properties, Abstract 10 double energy X-ray absorptiometry or computed tomography scanning techniques are used. Both methods allow the quantification of mineral content and bone mineral density. The most important property from a practical point of view is the bone’s bending strength, which is directly determined by the maximum bending force. The most important factors affecting bone strength are: • age (growth period), • gender and the associated hormonal balance, • genotype and modification of genes responsible for bone growth • chemical composition of the body (protein and fat content, and the proportion between these components), • physical activity and related bone load, • nutritional factors: – protein intake influencing synthesis of organic matrix of bone, – content of minerals in the feed (CA, P, Zn, Ca/P, Mg, Mn, Na, Cl, K, Cu ratio) influencing synthesis of the inorganic matrix of bone, – mineral/protein ratio in the diet (Ca/protein, P/protein, Zn/protein) – feed energy concentration, – energy source (content of saturated fatty acids - SFA, content of polyun saturated fatty acids - PUFA, in particular ALA, EPA, DPA, DHA), – feed additives, in particular: enzymes (e.g. phytase releasing of minerals bounded in phytin complexes), probiotics and prebiotics (e.g. inulin improving the function of the digestive tract by increasing absorption of nutrients), – vitamin content that regulate metabolism and biochemical changes occurring in bone tissue (e.g. vitamin D3, B6, C and K). This study was based on the results of research experiments from available literature, and studies on growing pigs carried out at the Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences. The tests were performed in total on 300 pigs of Duroc, Pietrain, Puławska breeds, line 990 and hybrids (Great White × Duroc, Great White × Landrace), PIC pigs, slaughtered at different body weight during the growth period from 15 to 130 kg. Bones for biomechanical tests were collected after slaughter from each pig. Their length, mass and volume were determined. Based on these measurements, the specific weight (density, g/cm3) was calculated. Then each bone was cut in the middle of the shaft and the outer and inner diameters were measured both horizontally and vertically. Based on these measurements, the following indicators were calculated: • cortical thickness, • cortical surface, • cortical index. Abstract 11 Bone strength was tested by a three-point bending test. The obtained data enabled the determination of: • bending force (the magnitude of the maximum force at which disintegration and disruption of bone structure occurs), • strength (the amount of maximum force needed to break/crack of bone), • stiffness (quotient of the force acting on the bone and the amount of displacement occurring under the influence of this force). Investigation of changes in physical and biomechanical features of bones during growth was performed on pigs of the synthetic 990 line growing from 15 to 130 kg body weight. The animals were slaughtered successively at a body weight of 15, 30, 40, 50, 70, 90, 110 and 130 kg. After slaughter, the following bones were separated from the right half-carcass: humerus, 3rd and 4th metatarsal bone, femur, tibia and fibula as well as 3rd and 4th metatarsal bone. The features of bones were determined using methods described in the methodology. Describing bone growth with the Gompertz equation, it was found that the earliest slowdown of bone growth curve was observed for metacarpal and metatarsal bones. This means that these bones matured the most quickly. The established data also indicate that the rib is the slowest maturing bone. The femur, humerus, tibia and fibula were between the values of these features for the metatarsal, metacarpal and rib bones. The rate of increase in bone mass and length differed significantly between the examined bones, but in all cases it was lower (coefficient b <1) than the growth rate of the whole body of the animal. The fastest growth rate was estimated for the rib mass (coefficient b = 0.93). Among the long bones, the humerus (coefficient b = 0.81) was characterized by the fastest rate of weight gain, however femur the smallest (coefficient b = 0.71). The lowest rate of bone mass increase was observed in the foot bones, with the metacarpal bones having a slightly higher value of coefficient b than the metatarsal bones (0.67 vs 0.62). The third bone had a lower growth rate than the fourth bone, regardless of whether they were metatarsal or metacarpal. The value of the bending force increased as the animals grew. Regardless of the growth point tested, the highest values were observed for the humerus, tibia and femur, smaller for the metatarsal and metacarpal bone, and the lowest for the fibula and rib. The rate of change in the value of this indicator increased at a similar rate as the body weight changes of the animals in the case of the fibula and the fourth metacarpal bone (b value = 0.98), and more slowly in the case of the metatarsal bone, the third metacarpal bone, and the tibia bone (values of the b ratio 0.81–0.85), and the slowest femur, humerus and rib (value of b = 0.60–0.66). Bone stiffness increased as animals grew. Regardless of the growth point tested, the highest values were observed for the humerus, tibia and femur, smaller for the metatarsal and metacarpal bone, and the lowest for the fibula and rib. Abstract 12 The rate of change in the value of this indicator changed at a faster rate than the increase in weight of pigs in the case of metacarpal and metatarsal bones (coefficient b = 1.01–1.22), slightly slower in the case of fibula (coefficient b = 0.92), definitely slower in the case of the tibia (b = 0.73), ribs (b = 0.66), femur (b = 0.59) and humerus (b = 0.50). Bone strength increased as animals grew. Regardless of the growth point tested, bone strength was as follows femur > tibia > humerus > 4 metacarpal> 3 metacarpal> 3 metatarsal > 4 metatarsal > rib> fibula. The rate of increase in strength of all examined bones was greater than the rate of weight gain of pigs (value of the coefficient b = 2.04–3.26). As the animals grew, the bone density increased. However, the growth rate of this indicator for the majority of bones was slower than the rate of weight gain (the value of the coefficient b ranged from 0.37 – humerus to 0.84 – fibula). The exception was the rib, whose density increased at a similar pace increasing the body weight of animals (value of the coefficient b = 0.97). The study on the influence of the breed and the feeding intensity on bone characteristics (physical and biomechanical) was performed on pigs of the breeds Duroc, Pietrain, and synthetic 990 during a growth period of 15 to 70 kg body weight. Animals were fed ad libitum or dosed system. After slaughter at a body weight of 70 kg, three bones were taken from the right half-carcass: femur, three metatarsal, and three metacarpal and subjected to the determinations described in the methodology. The weight of bones of animals fed aa libitum was significantly lower than in pigs fed restrictively All bones of Duroc breed were significantly heavier and longer than Pietrain and 990 pig bones. The average values of bending force for the examined bones took the following order: III metatarsal bone (63.5 kg) <III metacarpal bone (77.9 kg) <femur (271.5 kg). The feeding system and breed of pigs had no significant effect on the value of this indicator. The average values of the bones strength took the following order: III metatarsal bone (92.6 kg) <III metacarpal (107.2 kg) <femur (353.1 kg). Feeding intensity and breed of animals had no significant effect on the value of this feature of the bones tested. The average bone density took the following order: femur (1.23 g/cm3) <III metatarsal bone (1.26 g/cm3) <III metacarpal bone (1.34 g / cm3). The density of bones of animals fed aa libitum was higher (P<0.01) than in animals fed with a dosing system. The density of examined bones within the breeds took the following order: Pietrain race> line 990> Duroc race. The differences between the “extreme” breeds were: 7.2% (III metatarsal bone), 8.3% (III metacarpal bone), 8.4% (femur). Abstract 13 The average bone stiffness took the following order: III metatarsal bone (35.1 kg/mm) <III metacarpus (41.5 kg/mm) <femur (60.5 kg/mm). This indicator did not differ between the groups of pigs fed at different intensity, except for the metacarpal bone, which was more stiffer in pigs fed aa libitum (P<0.05). The femur of animals fed ad libitum showed a tendency (P<0.09) to be more stiffer and a force of 4.5 kg required for its displacement by 1 mm. Breed differences in stiffness were found for the femur (P <0.05) and III metacarpal bone (P <0.05). For femur, the highest value of this indicator was found in Pietrain pigs (64.5 kg/mm), lower in pigs of 990 line (61.6 kg/mm) and the lowest in Duroc pigs (55.3 kg/mm). In turn, the 3rd metacarpal bone of Duroc and Pietrain pigs had similar stiffness (39.0 and 40.0 kg/mm respectively) and was smaller than that of line 990 pigs (45.4 kg/mm). The thickness of the cortical bone layer took the following order: III metatarsal bone (2.25 mm) <III metacarpal bone (2.41 mm) <femur (5.12 mm). The feeding system did not affect this indicator. Breed differences (P <0.05) for this trait were found only for the femur bone: Duroc (5.42 mm)> line 990 (5.13 mm)> Pietrain (4.81 mm). The cross sectional area of the examined bones was arranged in the following order: III metatarsal bone (84 mm2) <III metacarpal bone (90 mm2) <femur (286 mm2). The feeding system had no effect on the value of this bone trait, with the exception of the femur, which in animals fed the dosing system was 4.7% higher (P<0.05) than in pigs fed ad libitum. Breed differences (P<0.01) in the coross sectional area were found only in femur and III metatarsal bone. The value of this indicator was the highest in Duroc pigs, lower in 990 animals and the lowest in Pietrain pigs. The cortical index of individual bones was in the following order: III metatarsal bone (31.86) <III metacarpal bone (33.86) <femur (44.75). However, its value did not significantly depend on the intensity of feeding or the breed of pigs.
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Pilmis, Olivier. Escaping the Reality Test. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198820802.003.0006.
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Economic crises regularly give rise to criticisms of economists and forecasters for having failed to blow the whistle. Forecasters’ efforts to deal with ‘errors’ and events that contradict their predictions show analogies between forecasting and magic as analysed by Henri Hubert and Marcel Mauss in the early twentieth century. The way forecasters depict the process of forecast production pinpoints three different sets of explanations for errors that together seek to discard ‘reality’ (‘what actually happened’) as a relevant criterion for judging forecasts (‘what had been predicted’). Forecasters argue that the ontological indeterminacy of economies and the presence of unanticipated shocks absolve them from blame; they emphasize the value of identifying causal narratives and scenarios even when point forecasts are wrong; and they stress the importance of adhering to professional methods or rituals.
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Shephard OAM, Mark, ed. Practical Guide to Global Point-of-Care Testing. CSIRO Publishing, 2016. http://dx.doi.org/10.1071/9781486305193.
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Point-of-care testing (POCT) refers to pathology testing performed in a clinical setting at the time of patient consultation, generating a rapid test result that enables informed and timely clinical action to be taken on patient care. It offers patients greater convenience and access to health services and helps to improve clinical outcomes. POCT also provides innovative solutions for the detection and management of chronic, acute and infectious diseases, in settings including family practices, Indigenous medical services, community health facilities, rural and remote areas and in developing countries, where health-care services are often geographically isolated from the nearest pathology laboratory.
A Practical Guide to Global Point-of-Care Testing shows health professionals how to set up and manage POCT services under a quality-assured, sustainable, clinically and culturally effective framework, as well as understand the wide global scope and clinical applications of POCT.
The book is divided into three major themes: the management of POCT services, a global perspective on the clinical use of POCT, and POCT for specific clinical settings. Chapters within each theme are written by experts and explore wide-ranging topics such as selecting and evaluating devices, POCT for diabetes, coagulation disorders, HIV, malaria and Ebola, and the use of POCT for disaster management and in extreme environments. Figures are included throughout to illustrate the concepts, principles and practice of POCT.
Written for a broad range of practicing health professionals from the fields of medical science, health science, nursing, medicine, paramedic science, Indigenous health, public health, pharmacy, aged care and sports medicine, A Practical Guide to Global Point-of-Care Testing will also benefit university students studying these health-related disciplines.
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Send, Wolfgang. Winged artifacts. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780199674923.003.0046.
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Winged artifacts aim at the imitation of nature’s ingenious method to produce thrust with slim and smart-shaped flapping surfaces—the bending-torsional drive. The kinematics of these surfaces shows, in three dimensions, a bending motion coupled with a simultaneous torsion. This chapter describes the design and development of the artificial bird SmartBird, which was introduced in 2011 on the occasion of the annual international industry fair Hannovermesse. This artwork with articulated wings received worldwide attention through its unprecedented agility. The efficient motion of bodies heavier than air rests on the optimization of target functions like total weight to be balanced by lift, flow resistance to be balanced by thrust, structural layout and reliability, energy storage and, last but not least, smart flight control. From the author’s point of view, the bending-torsional drive just has started its career as a new player in this optimization game.
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Einstein, Andrew J. Radiation Considerations. Oxford University Press, 2015. http://dx.doi.org/10.1093/med/9780199392094.003.0034.
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Radiation considerations are an integral part of the practice of nuclear cardiac imaging. Concern regarding radiation has increased in recent years, reflected in statements by many professional societies, and likely attributable both to rapid growth in use of nuclear cardiology as well as high doses received by some nuclear cardiology patients. The fundamental principles of medical radiological protection are justification (ensuring that the right test is performed for the right patient at the right time), optimization (ensuring that the test is performed in the right manner), and dose limitation, which while applicable to healthcare workers is not operative regarding patients. Three "As" facilitate and serve as an organizing principle for justification: awareness, appropriateness, and audit. Awareness incorporates knowledge of the benefits and risks of testing involving radiation and effective communication of these to the patient. Appropriateness in nuclear cardiology can be assessed using the American College of Cardiology's appropriateness criteria. Methods that have been demonstrated to improve appropriateness include using a collaborative learning model, a point-of-order decision support tool, and a multifaceted intervention including threatened loss of insurance coverage. A variety of strategies should be considered for optimization to ensure patient-centered imaging. These including strategic selection of both the protocol, e.g. selecting a stress-first protocol and performing stress-only imaging in patients without a high pre-test probability of abnormal findings on stress imaging, or using PET, and also the administered activity, e.g. by using weight-based dosing and/or software- or hardware-based advances in camera technology. Special considerations are required for pregnant, nursing, and pediatric patients.
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Hymans, Jacques E. C. Nuclear Proliferation and Non-Proliferation. Oxford University Press, 2017. http://dx.doi.org/10.1093/acrefore/9780190846626.013.271.
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Nuclear proliferation became an increasingly major concern after France and then China joined the nuclear “club” in the 1960s. However, it was not until India’s “peaceful nuclear explosive” test of 1974 that a real sense of potential worldwide crisis emerged, which also spawned a substantial amount of serious writing on the issue. The basic puzzle facing the study of nuclear proliferation is why there is a considerable and persistent disparity between the number of nuclear weapons-capable states and the number of actual nuclear weapons states. Three early works that represented crucial conceptual breakthroughs in the struggle toward a proper descriptive inference of the dynamics of proliferation are William Epstein’s The Last Chance (1976), Stephen M. Meyer’s The Dynamics of Nuclear Proliferation (1984), and Opaque Nuclear Proliferation (1991), edited by Benjamin Frankel. More contemporary political science work features attempts by each of the major international relations paradigms to tackle the proliferation puzzle: realism, psychological constructivism, neoliberal institutionalism, liberalism, and sociological constructivism. While scholars disagree over a host of issues, a consensus on the dynamics of nuclear proliferation may be discerned. In particular, there are five points on which most recent works converge: that proliferation has been historically rare; that we cannot take the demand for nuclear weapons for granted; that domestic politics and identity considerations play a crucial role in shaping proliferation choices; and that theory-guided, in-depth comparative case studies are the most appropriate means of advancing the state of our knowledge at this point in time.
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Ślusarski, Marek. Metody i modele oceny jakości danych przestrzennych. Publishing House of the University of Agriculture in Krakow, 2017. http://dx.doi.org/10.15576/978-83-66602-30-4.
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The quality of data collected in official spatial databases is crucial in making strategic decisions as well as in the implementation of planning and design works. Awareness of the level of the quality of these data is also important for individual users of official spatial data. The author presents methods and models of description and evaluation of the quality of spatial data collected in public registers. Data describing the space in the highest degree of detail, which are collected in three databases: land and buildings registry (EGiB), geodetic registry of the land infrastructure network (GESUT) and in database of topographic objects (BDOT500) were analyzed. The results of the research concerned selected aspects of activities in terms of the spatial data quality. These activities include: the assessment of the accuracy of data collected in official spatial databases; determination of the uncertainty of the area of registry parcels, analysis of the risk of damage to the underground infrastructure network due to the quality of spatial data, construction of the quality model of data collected in official databases and visualization of the phenomenon of uncertainty in spatial data. The evaluation of the accuracy of data collected in official, large-scale spatial databases was based on a representative sample of data. The test sample was a set of deviations of coordinates with three variables dX, dY and Dl – deviations from the X and Y coordinates and the length of the point offset vector of the test sample in relation to its position recognized as a faultless. The compatibility of empirical data accuracy distributions with models (theoretical distributions of random variables) was investigated and also the accuracy of the spatial data has been assessed by means of the methods resistant to the outliers. In the process of determination of the accuracy of spatial data collected in public registers, the author’s solution was used – resistant method of the relative frequency. Weight functions, which modify (to varying degree) the sizes of the vectors Dl – the lengths of the points offset vector of the test sample in relation to their position recognized as a faultless were proposed. From the scope of the uncertainty of estimation of the area of registry parcels the impact of the errors of the geodetic network points was determined (points of reference and of the higher class networks) and the effect of the correlation between the coordinates of the same point on the accuracy of the determined plot area. The scope of the correction was determined (in EGiB database) of the plots area, calculated on the basis of re-measurements, performed using equivalent techniques (in terms of accuracy). The analysis of the risk of damage to the underground infrastructure network due to the low quality of spatial data is another research topic presented in the paper. Three main factors have been identified that influence the value of this risk: incompleteness of spatial data sets and insufficient accuracy of determination of the horizontal and vertical position of underground infrastructure. A method for estimation of the project risk has been developed (quantitative and qualitative) and the author’s risk estimation technique, based on the idea of fuzzy logic was proposed. Maps (2D and 3D) of the risk of damage to the underground infrastructure network were developed in the form of large-scale thematic maps, presenting the design risk in qualitative and quantitative form. The data quality model is a set of rules used to describe the quality of these data sets. The model that has been proposed defines a standardized approach for assessing and reporting the quality of EGiB, GESUT and BDOT500 spatial data bases. Quantitative and qualitative rules (automatic, office and field) of data sets control were defined. The minimum sample size and the number of eligible nonconformities in random samples were determined. The data quality elements were described using the following descriptors: range, measure, result, and type and unit of value. Data quality studies were performed according to the users needs. The values of impact weights were determined by the hierarchical analytical process method (AHP). The harmonization of conceptual models of EGiB, GESUT and BDOT500 databases with BDOT10k database was analysed too. It was found that the downloading and supplying of the information in BDOT10k creation and update processes from the analyzed registers are limited. An effective approach to providing spatial data sets users with information concerning data uncertainty are cartographic visualization techniques. Based on the author’s own experience and research works on the quality of official spatial database data examination, the set of methods for visualization of the uncertainty of data bases EGiB, GESUT and BDOT500 was defined. This set includes visualization techniques designed to present three types of uncertainty: location, attribute values and time. Uncertainty of the position was defined (for surface, line, and point objects) using several (three to five) visual variables. Uncertainty of attribute values and time uncertainty, describing (for example) completeness or timeliness of sets, are presented by means of three graphical variables. The research problems presented in the paper are of cognitive and application importance. They indicate on the possibility of effective evaluation of the quality of spatial data collected in public registers and may be an important element of the expert system.
Book chapters on the topic "Three Point Bending Test"
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Carpinteri, A., B. Chiaia, and P. Cornetti. "Three-Point Bending Test in Brittle Materials." In Problems of Fracture Mechanics and Fatigue, 173–76. Dordrecht: Springer Netherlands, 2003. http://dx.doi.org/10.1007/978-94-017-2774-7_38.
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Carpinteri, A., B. Chiaia, and P. Cornetti. "Three-Point Bending Test in Quasi Brittle Materials." In Problems of Fracture Mechanics and Fatigue, 177–81. Dordrecht: Springer Netherlands, 2003. http://dx.doi.org/10.1007/978-94-017-2774-7_39.
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Kashef, S., S. A. Asgari, Peter Hodgson, and Wen Yi Yan. "Simulation of Three-Point Bending Test of Titanium Foam for Biomedical Applications." In Frontiers in Materials Science and Technology, 237–40. Stafa: Trans Tech Publications Ltd., 2008. http://dx.doi.org/10.4028/0-87849-475-8.237.
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Shahzamanian, M. M., Amir Partovi, and P. D. Wu. "Study of Pre-strain Effect on Bendability in Three-Point Bending Test." In Lecture Notes in Mechanical Engineering, 261–68. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-15-9893-7_18.
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Solovev, I. A., M. V. Shitikova, and A. V. Mazaev. "Static Three-Point Bending Tests on 3D Printed Multilayer Composite Plates." In Proceedings of the 6th International Conference on Construction, Architecture and Technosphere Safety, 206–16. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-21120-1_20.
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Belan, J., L. Hurtalová, A. Vaško, E. Tillová, and M. Chalupová. "Fatigue Test of the Inconel Alloy 718 Under Three Point Bending Load at Low Frequency." In Properties and Characterization of Modern Materials, 75–84. Singapore: Springer Singapore, 2016. http://dx.doi.org/10.1007/978-981-10-1602-8_7.
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Tanaka, Kazuto, Yusuke Kita, Tsutao Katayama, and Mami Matsukawa. "Mechanical Properties of a Single Trabecula in Bovine Femur by the Three Point Bending Test." In IFMBE Proceedings, 235–38. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-12020-6_59.
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Pierron, F., M. A. Sutton, and V. Tiwari. "Ultra high speed DIC on a three point bending test mounted on a Hopkinson bar." In Application of Imaging Techniques to Mechanics of Materials and Structures, Volume 4, 451–60. New York, NY: Springer New York, 2012. http://dx.doi.org/10.1007/978-1-4419-9796-8_58.
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Stergiopoulos, Charalampos, Ilias Stavrakas, Dimos Triantis, George Hloupis, and Filippos Vallianatos. "The Use of PSC Technique to Estimate the Damage Extension During Three Point Bending Test." In Mechanical and Materials Engineering of Modern Structure and Component Design, 363–72. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-19443-1_29.
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Rosnitschek, Tobias, Annika Gläseke, Florian Hüter, Bettina Alber-Laukant, and Stephan Tremmel. "Optimization of Fused Filament Fabricated Infill Patterns for Sandwich Structures in a Three-Point Bending Test." In Proceedings of the Munich Symposium on Lightweight Design 2021, 115–23. Berlin, Heidelberg: Springer Berlin Heidelberg, 2022. http://dx.doi.org/10.1007/978-3-662-65216-9_11.
Full textConference papers on the topic "Three Point Bending Test"
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Guo*, Junxin. "Poroviscoelastic behaviors of the shale sample in the three-point bending test." In SEG Technical Program Expanded Abstracts 2015. Society of Exploration Geophysicists, 2015. http://dx.doi.org/10.1190/segam2015-5881520.1.
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Verbeek, A. T. J., J. M. Houben, and J. A. Klostermann. "Acoustic Emission Evaluation of Thermal Barrier Coatings Using the Three Point Bending Test." In ASME 1991 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1991. http://dx.doi.org/10.1115/91-gt-179.
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Thermal Barrier coatings were tested in three point bending tests, combined with acoustic emission evaluation. The test specimens consist of a 2 mm substrate with a 0.1 mm FeCrAlY bondcoat and a 0.3 mm ZrO2/Y2O3 93/7.8 weight % topcoat. Both the topcoat and the bondcoat were air plasma sprayed under varying conditions of the substrate cooling and the length of the plasma flame. On investigating the microstructure of the coatings, using light and electron microscopy, differences could be observed, due to the various spraying techniques. The coated specimens were tested in a tensile testing machine equiped with a special tool for three point bending tests. During bending, acoustic emissions from the coating were measured, using a two channel acoustic emission apparatus. Two types of AE sensors were used, namely a 150 kHz resonance sensor and a 0.1 −1 MHz wide band sensor. The various coatings show different AE patterns, especially the bondcoats which showed differences according to the spraying techniques. The use of wide band sensors had some advantages, however they were less sensitive than resonance sensors, they take signals that were received by the resonance ones. After testing, the specimens were prepared and microscopically investigated. Herewith it was possible to establish a relationship between the measured AE signal and the type of coating and coating failure.
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Guo*, Junxin. "Estimation of permeability and viscoelastic properties of shale by three-point bending test." In SEG Technical Program Expanded Abstracts 2015. Society of Exploration Geophysicists, 2015. http://dx.doi.org/10.1190/segam2015-5882257.1.
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ZHAO, BANGHUA, WENBIN YU, JAFFE TSENG, and RONG CHIU. "Characterization of Bending Stiffness for Honeycomb Sandwich Plate in Three-point Bending Test Using Mechanics of Structure Genome." In American Society for Composites 2019. Lancaster, PA: DEStech Publications, Inc., 2019. http://dx.doi.org/10.12783/asc34/31396.
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Binkowski, Marcin, Grzegorz Kokot, Filip Bolechala, and Antoni John. "Image-based finite element modeling of the three-point bending test of cortical bone." In SPIE Optical Engineering + Applications, edited by Stuart R. Stock. SPIE, 2012. http://dx.doi.org/10.1117/12.981918.
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Liu, Yun, and Yin Zhang. "Extracting nanowire mechanical properties from three-point bendig test." In 2010 12th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm). IEEE, 2010. http://dx.doi.org/10.1109/itherm.2010.5501304.
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González-Bárcenas, L. A. "Three Point Bending Test of Human Femoral Tissue: An Essay in Ancient and Modern Bones." In MEDICAL PHYSICS: Seventh Mexican Symposium on Medical Physics. AIP, 2003. http://dx.doi.org/10.1063/1.1615117.
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Miarka, P. "Fracture behaviour of alkali activated concrete measured from three-point bending test with Chevron notch." In 10th International Conference on Fracture Mechanics of Concrete and Concrete Structures. IA-FraMCoS, 2019. http://dx.doi.org/10.21012/fc10.239758.
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Chun, K. J., C. Y. Kim, and J. Y. Lee. "A Study on Mechanical Behavior of Dental Hard Tissues and Dental Restorative Materials by Three-Point Bending Test." In ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-36645.
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Dental restorative materials including amalgam, dental ceramic, gold alloy, dental resin, zirconia, and titanium alloy are used to reconstruct damaged teeth, as well as to recover their function. In this study, the mechanical properties of various dental restorative materials were determined using test specimens of identical shape and dimension under the same three-point bending test condition, and the test results were compared to enamel and dentin. The maximum bending force of enamel and dentin was 6.9 ± 2.1 N and 39.7 ± 8.3 N, and the maximum bending deflection was 0.12 ± 0.02 mm and 0.25 ± 0.03 mm, respectively. The maximum bending force of amalgam, dental ceramic, gold alloy, dental resin, zirconia, and titanium alloy were 1.9 ± 0.4 N, 2.7 ± 0.6 N, 66.9 ± 4.1 N, 2.7 ± 0.3 N, 19.0 ± 2.0 N, and 121.3 ± 6.8 N, respectively, and the maximum bending deflection was 0.20 ± 0.08 mm, 0.28 ± 0.07 mm, 2.53 ± 0.12 mm, 0.37 ± 0.05 mm, 0.39 ± 0.05 m, and 2.80 ± 0.08 mm, respectively. The dental restorative materials that possessed greater maximum bending force than that of enamel were gold alloy, zirconia, and titanium alloy. Gold alloy and titanium alloy had greater maximum bending force than dentin. The dental restorative materials that possessed greater maximum bending deflection than that of enamel were all of the dental restorative materials, and the dental restorative materials that possessed greater maximum bending deflection than that of dentin were all of the dental restorative materials except amalgam. The appropriate dental restorative materials for enamel are gold alloy and zirconia and for dentin is gold alloy concerning the maximum bending force and the maximum bending deflection. These results are expected to aid dentists in their choice of better clinical treatment and to contribute to the development of dental restorative materials that possess properties that are most similar to the mechanical properties of dental hard tissue.
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Champliaud, Henri, Zhengkun Feng, and Harald Bersee. "Three-Point Bending Testing of Sandwich Beams and Finite Element Comparison." In ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-12440.
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The results of 3-point bending tests applied on 4 different types of composite beam structure and their comparison with Finite Element Modeling (FEM) are presented. Three different layups have been applied on rectangular and hexagonal foam cross sections. Experiments are realized and compared with FEM results in order to create a more confident design of an adaptive wind turbine blade that will be built using a foam core and a fiber glass/epoxy skin. Even if torsion loads and centrifugal loads are present on wind turbine blade during operation, the major loads are due to bending moments, so emphasis is put on 3-point bending tests of sandwich like composite beams. Tests and FEM show that the sandwich beam behavior is closely related to the skin and foam thicknesses.
Reports on the topic "Three Point Bending Test"
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Lassila, D. H., F. Magness, and D. Freeman. Ductile-Brittle Transition Temperature testing of tungsten using the three-point bend test. Office of Scientific and Technical Information (OSTI), March 1991. http://dx.doi.org/10.2172/5273161.
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Keller, Jonathan, Yi Guo, Zhiwei Zhang, and Doug Lucas. Planetary Load Sharing in Three-Point Mounted Wind Turbine Gearboxes: A Design and Test Comparison. Office of Scientific and Technical Information (OSTI), April 2017. http://dx.doi.org/10.2172/1351159.
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Patel, Reena. Complex network analysis for early detection of failure mechanisms in resilient bio-structures. Engineer Research and Development Center (U.S.), June 2021. http://dx.doi.org/10.21079/11681/41042.
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Bio-structures owe their remarkable mechanical properties to their hierarchical geometrical arrangement as well as heterogeneous material properties. This dissertation presents an integrated, interdisciplinary approach that employs computational mechanics combined with flow network analysis to gain fundamental insights into the failure mechanisms of high performance, light-weight, structured composites by examining the stress flow patterns formed in the nascent stages of loading for the rostrum of the paddlefish. The data required for the flow network analysis was generated from the finite element analysis of the rostrum. The flow network was weighted based on the parameter of interest, which is stress in the current study. The changing kinematics of the structural system was provided as input to the algorithm that computes the minimum-cut of the flow network. The proposed approach was verified using two classical problems three- and four-point bending of a simply-supported concrete beam. The current study also addresses the methodology used to prepare data in an appropriate format for a seamless transition from finite element binary database files to the abstract mathematical domain needed for the network flow analysis. A robust, platform-independent procedure was developed that efficiently handles the large datasets produced by the finite element simulations. Results from computational mechanics using Abaqus and complex network analysis are presented.
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Bigl, Matthew, Samuel Beal, and Charles Ramsey. Determination of residual low-order detonation particle characteristics from IMX-104 mortar rounds. Engineer Research and Development Center (U.S.), September 2021. http://dx.doi.org/10.21079/11681/42163.
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The environmental fate and transport of energetic compounds on military training ranges are largely controlled by the particle characteristics of low-order detonations. This study demonstrated a method of command detonation, field sampling, laboratory processing, and analysis techniques for characterizing low-order detonation particles from 60 mm and 81 mm mortar rounds containing the insensitive munition formulation IMX-104. Particles deposited from three rounds of each caliber were comprehensively sampled and characterized for particle size, energetic purity, and morphology. The 60 mm rounds were command-detonated low order consistently (seven low-order detonations of seven tested rounds), with con-sumption efficiencies of 62%–80% (n = 3). The 81 mm rounds detonated low order inconsistently (three low-order detonations of ten tested rounds), possibly because the rounds were sourced from manufacturing test runs. These rounds had lower consumption efficiencies of 39%–64% (n = 3). Particle-size distributions showed significant variability between munition calibers, between rounds of the same caliber, and with distance from the detonation point. The study reviewed command-detonation configurations, particle transfer losses during sampling and particle-size analysis, and variations in the energetic purity of recovered particles. Overall, this study demonstrated the successful characterization of IMX-104 low-order detonation particles from command detonation to analysis.
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Tawfik, Aly, Deify Law, Juris Grasis, Joseph Oldham, and Moe Salem. COVID-19 Public Transportation Air Circulation and Virus Mitigation Study. Mineta Transportation Institute, June 2022. http://dx.doi.org/10.31979/mti.2021.2036.
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COVID-19 may have forever changed our world. Given the limited space and air circulation, potential infections on public transportation could be concerningly high. Accordingly, this study has two objectives: (1) to understand air circulation patterns inside the cabins of buses; and (2) to test the impact of different technologies in mitigating viruses from the air and on surfaces inside bus cabins. For the first objective, different devices, metrics and experiments (including colored smoke; videotaping; anemometers; pressure differentials; particle counts; and 3D numerical simulation models) were utilized and implemented to understand and quantify air circulation inside different buses, with different characteristics, and under different operating conditions (e.g. with windows open and shut). For the second objective, three different live prokaryotic viruses were utilized: Phi6, MS2 and T7. Various technologies (including positive pressure environment inside the cabin, HEPA filters with different MERV ratings, concentrated UV exposure with charged carbon filters in the HVAC systems, center point photocatalytic oxidation technology, ionization, and surface antiviral agents) were tested to evaluate the potential of mitigating COVID-19 infections via air and surfaces in public transportation. The effectiveness of these technologies on the three live viruses was tested in both the lab and in buses in the field. The results of the first objective experiments indicated the efficiency of HVAC system designs, where the speed of air spread was consistently much faster than the speed of air clearing. Hence, indicating the need for additional virus mitigation from the cabin. Results of the second objective experiments indicated that photocatalytic oxidation inserts and UVC lights were the most efficient in mitigating viruses from the air. On the other hand, positive pressure mitigated all viruses from surfaces; however, copper foil tape and fabrics with a high percentage of copper mitigated only the Phi6 virus from surfaces. High-temperature heating was also found to be highly effective in mitigating the different viruses from the vehicle cabin. Finally, limited exploratory experiments to test possible toxic by-products of photocatalytic oxidation and UVC lights inside the bus cabin did not detect any increase in levels of formaldehyde, ozone, or volatile organic compounds. Implementation of these findings in transit buses, in addition to the use of personal protective equipment, could be significantly valuable for protection of passengers and drivers on public transportation modes, possibly against all forms of air-borne viruses.
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Tawfik, Aly, Deify Law, Juris Grasis, Joseph Oldham, and Moe Salem. COVID-19 Public Transportation Air Circulation and Virus Mitigation Study. Mineta Transportation Institute, June 2022. http://dx.doi.org/10.31979/mti.2022.2036.
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COVID-19 may have forever changed our world. Given the limited space and air circulation, potential infections on public transportation could be concerningly high. Accordingly, this study has two objectives: (1) to understand air circulation patterns inside the cabins of buses; and (2) to test the impact of different technologies in mitigating viruses from the air and on surfaces inside bus cabins. For the first objective, different devices, metrics and experiments (including colored smoke; videotaping; anemometers; pressure differentials; particle counts; and 3D numerical simulation models) were utilized and implemented to understand and quantify air circulation inside different buses, with different characteristics, and under different operating conditions (e.g. with windows open and shut). For the second objective, three different live prokaryotic viruses were utilized: Phi6, MS2 and T7. Various technologies (including positive pressure environment inside the cabin, HEPA filters with different MERV ratings, concentrated UV exposure with charged carbon filters in the HVAC systems, center point photocatalytic oxidation technology, ionization, and surface antiviral agents) were tested to evaluate the potential of mitigating COVID-19 infections via air and surfaces in public transportation. The effectiveness of these technologies on the three live viruses was tested in both the lab and in buses in the field. The results of the first objective experiments indicated the efficiency of HVAC system designs, where the speed of air spread was consistently much faster than the speed of air clearing. Hence, indicating the need for additional virus mitigation from the cabin. Results of the second objective experiments indicated that photocatalytic oxidation inserts and UVC lights were the most efficient in mitigating viruses from the air. On the other hand, positive pressure mitigated all viruses from surfaces; however, copper foil tape and fabrics with a high percentage of copper mitigated only the Phi6 virus from surfaces. High-temperature heating was also found to be highly effective in mitigating the different viruses from the vehicle cabin. Finally, limited exploratory experiments to test possible toxic by-products of photocatalytic oxidation and UVC lights inside the bus cabin did not detect any increase in levels of formaldehyde, ozone, or volatile organic compounds. Implementation of these findings in transit buses, in addition to the use of personal protective equipment, could be significantly valuable for protection of passengers and drivers on public transportation modes, possibly against all forms of air-borne viruses.
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Warrick, Arthur W., Gideon Oron, Mary M. Poulton, Rony Wallach, and Alex Furman. Multi-Dimensional Infiltration and Distribution of Water of Different Qualities and Solutes Related Through Artificial Neural Networks. United States Department of Agriculture, January 2009. http://dx.doi.org/10.32747/2009.7695865.bard.
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The project exploits the use of Artificial Neural Networks (ANN) to describe infiltration, water, and solute distribution in the soil during irrigation. It provides a method of simulating water and solute movement in the subsurface which, in principle, is different and has some advantages over the more common approach of numerical modeling of flow and transport equations. The five objectives were (i) Numerically develop a database for the prediction of water and solute distribution for irrigation; (ii) Develop predictive models using ANN; (iii) Develop an experimental (laboratory) database of water distribution with time; within a transparent flow cell by high resolution CCD video camera; (iv) Conduct field studies to provide basic data for developing and testing the ANN; and (v) Investigate the inclusion of water quality [salinity and organic matter (OM)] in an ANN model used for predicting infiltration and subsurface water distribution. A major accomplishment was the successful use of Moment Analysis (MA) to characterize “plumes of water” applied by various types of irrigation (including drip and gravity sources). The general idea is to describe the subsurface water patterns statistically in terms of only a few (often 3) parameters which can then be predicted by the ANN. It was shown that ellipses (in two dimensions) or ellipsoids (in three dimensions) can be depicted about the center of the plume. Any fraction of water added can be related to a ‘‘probability’’ curve relating the size of the ellipse (or ellipsoid) that contains that amount of water. The initial test of an ANN to predict the moments (and hence the water plume) was with numerically generated data for infiltration from surface and subsurface drip line and point sources in three contrasting soils. The underlying dataset consisted of 1,684,500 vectors (5 soils×5 discharge rates×3 initial conditions×1,123 nodes×20 print times) where each vector had eleven elements consisting of initial water content, hydraulic properties of the soil, flow rate, time and space coordinates. The output is an estimate of subsurface water distribution for essentially any soil property, initial condition or flow rate from a drip source. Following the formal development of the ANN, we have prepared a “user-friendly” version in a spreadsheet environment (in “Excel”). The input data are selected from appropriate values and the output is instantaneous resulting in a picture of the resulting water plume. The MA has also proven valuable, on its own merit, in the description of the flow in soil under laboratory conditions for both wettable and repellant soils. This includes non-Darcian flow examples and redistribution and well as infiltration. Field experiments were conducted in different agricultural fields and various water qualities in Israel. The obtained results will be the basis for the further ANN models development. Regions of high repellence were identified primarily under the canopy of various orchard crops, including citrus and persimmons. Also, increasing OM in the applied water lead to greater repellency. Major scientific implications are that the ANN offers an alternative to conventional flow and transport modeling and that MA is a powerful technique for describing the subsurface water distributions for normal (wettable) and repellant soil. Implications of the field measurements point to the special role of OM in affecting wettability, both from the irrigation water and from soil accumulation below canopies. Implications for agriculture are that a modified approach for drip system design should be adopted for open area crops and orchards, and taking into account the OM components both in the soil and in the applied waters.
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Weissinger, Rebecca. Trends in water quality at Bryce Canyon National Park, water years 2006–2021. Edited by Alice Wondrak Biel. National Park Service, November 2022. http://dx.doi.org/10.36967/2294946.
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The National Park Service collects water-quality samples on a rotating basis at three fixed water-quality stations in Bryce Canyon National Park (NP): Sheep Creek, Yellow Creek, and Mossy Cave Spring. Data collection began at Sheep Creek and Yellow Creek in November 2005 and at Mossy Cave in July 2008. Data on in-situ parameters, fecal-coliform samples, major ions, and nutrients are collected monthly, while trace elements are sampled quarterly. This report analyzes data from the beginning of the period of record for each station through water year 2021 to test for trends over time. Concentrations are also compared to relevant water-quality standards for the State of Utah. Overall, water quality at the park’s monitoring stations continues to be excellent, and park managers have been successful in their goal of maintaining these systems in unimpaired condition. Infrequent but continued Escherichia coli exceedances from trespass livestock at Sheep and Yellow creeks support the need for regular fence maintenance along the park boundary. High-quality conditions may qualify all three sites as Category 1 waters, the highest level of anti-degradation protection provided by the State of Utah. Minimum and maximum air temperatures at the park have increased, while precipitation remains highly variable. Increasing air temperatures have led to increasing water temperatures in Sheep and Yellow creeks. Sheep Creek also had a decrease in flow across several quantiles from 2006 to 2021, while higher flows decreased at Yellow Creek in the same period. Surface flows in these two creeks are likely to be increasingly affected by higher evapotranspiration due to warming air temperatures and possibly decreasing snowmelt runoff as the climate changes. The influx of ancient groundwater in both creek drainages helps sustain base flows at the sites. Mossy Cave Spring, which is sampled close to the spring emergence point, showed less of a climate signal than Sheep and Yellow creeks. In our record, the spring shows a modest increase in discharge, including higher flows at higher air temperatures. An uptick in visitation to Water Canyon and the Mossy Cave Trail has so far not been reflected by changes in water quality. There are additional statistical trends in water-quality parameters at all three sites. However, most of these trends are quite small and are likely ecologically negligible. Some statistical trends may be the result of instrument changes and improvements in quality assurance and quality control over time in both the field sampling effort and the laboratory analyses. Long-term monitoring of water-quality stations at Bryce Canyon NP suggests relatively stable aquatic systems that benefit from protection within the park. To maintain these unimpaired conditions into the future, park managers could consider: Regular fence checks and maintenance along active grazing allotments at the park boundary to protect riparian areas and aquatic systems from trespass livestock. Developing a springs-monitoring program to track changes in springflow at spring emergences to better understand bedrock-aquifer water supplies. These data would also help quantify springflow for use in water-rights hearings. Supporting hydrogeologic investigations to map the extent and flow paths of groundwater aquifers. Working with the State of Utah to develop groundwater-protection zones to protect groundwater aquifers from developments that would affect springs in the park. Prioritizing watershed management with proactive fire risk-reduction practices. Explicitly including watershed protection as a goal in plans for fire management and suppression. Using additional data and analyses to better understand the drivers of trends in water quality and their ecological significance. These could include higher-frequency data to better understand relationships between groundwater, precipitation, and surface flows at the sites. These could also include watershed metrics...
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Lahav, Ori, Albert Heber, and David Broday. Elimination of emissions of ammonia and hydrogen sulfide from confined animal and feeding operations (CAFO) using an adsorption/liquid-redox process with biological regeneration. United States Department of Agriculture, March 2008. http://dx.doi.org/10.32747/2008.7695589.bard.
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The project was originally aimed at investigating and developing new efficient methods for cost effective removal of ammonia (NH₃) and hydrogen sulfide (H₂S) from Concentrated Animal Feeding Operations (CAFO), in particular broiler and laying houses (NH₃) and hog houses (H₂S). In both cases, the principal idea was to design and operate a dedicated air collection system that would be used for the treatment of the gases, and that would work independently from the general ventilation system. The advantages envisaged: (1) if collected at a point close to the source of generation, pollutants would arrive at the treatment system at higher concentrations; (2) the air in the vicinity of the animals would be cleaner, a fact that would promote animal growth rates; and (3) collection efficiency would be improved and adverse environmental impact reduced. For practical reasons, the project was divided in two: one effort concentrated on NH₃₍g₎ removal from chicken houses and another on H₂S₍g₎ removal from hog houses. NH₃₍g₎ removal: a novel approach was developed to reduce ammonia emissions from CAFOs in general, and poultry houses in particular. Air sucked by the dedicated air capturing system from close to the litter was shown to have NH₃₍g₎ concentrations an order of magnitude higher than at the vents of the ventilation system. The NH₃₍g₎ rich waste air was conveyed to an acidic (0<pH<~5) bubble column reactor where NH₃ was converted to NH₄⁺. The reactor operated in batch mode, starting at pH 0 and was switched to a new acidic absorption solution just before NH₃₍g₎ breakthrough occurred, at pH ~5. Experiments with a wide range of NH₃₍g₎ concentrations showed that the absorption efficiency was practically 100% throughout the process as long as the face velocity was below 4 cm/s. The potential advantages of the method include high absorption efficiency, lower NH₃₍g₎ concentrations in the vicinity of the birds, generation of a valuable product and the separation between the ventilation and ammonia treatment systems. A small scale pilot operation conducted for 5 weeks in a broiler house showed the approach to be technically feasible. H₂S₍g₎ removal: The main goal of this part was to develop a specific treatment process for minimizing H₂S₍g₎ emissions from hog houses. The proposed process consists of three units: In the 1ˢᵗ H₂S₍g₎ is absorbed into an acidic (pH<2) ferric iron solution and oxidized by Fe(III) to S⁰ in a bubble column reactor. In parallel, Fe(III) is reduced to Fe(II). In the 2ⁿᵈ unit Fe(II) is bio-oxidized back to Fe(III) by Acidithiobacillus ferrooxidans (AF).In the 3ʳᵈ unit S⁰ is separated from solution in a gravity settler. The work focused on three sub-processes: the kinetics of H₂S absorption into a ferric solution at low pH, the kinetics of Fe²⁺ oxidation by AF and the factors that affect ferric iron precipitation (a main obstacle for a continuous operation of the process) under the operational conditions. H₂S removal efficiency was found higher at a higher Fe(III) concentration and also higher for higher H₂S₍g₎ concentrations and lower flow rates of the treated air. The rate limiting step of the H₂S reactive absorption was found to be the chemical reaction rather than the transition from gas to liquid phase. H₂S₍g₎ removal efficiency of >95% was recorded with Fe(III) concentration of 9 g/L using typical AFO air compositions. The 2ⁿᵈ part of the work focused on kinetics of Fe(II) oxidation by AF. A new lab technique was developed for determining the kinetic equation and kinetic parameters (KS, Kₚ and mₘₐₓ) for the bacteria. The 3ʳᵈ part focused on iron oxide precipitation under the operational conditions. It was found that at lower pH (1.5) jarosite accumulation is slower and that the performance of the AF at this pH was sufficient for successive operation of the proposed process at the H₂S fluxes predicted from AFOs. A laboratory-scale test was carried out at Purdue University on the use of the integrated system for simultaneous hydrogen sulfide removal from a H₂S bubble column filled with ferric sulfate solution and biological regeneration of ferric ions in a packed column immobilized with enriched AFbacteria. Results demonstrated the technical feasibility of the integrated system for H₂S removal and simultaneous biological regeneration of Fe(III) for potential continuous treatment of H₂S released from CAFO. NH₃ and H₂S gradient measurements at egg layer and swine barns were conducted in winter and summer at Purdue. Results showed high potential to concentrate NH₃ and H₂S in hog buildings, and NH₃ in layer houses. H₂S emissions from layer houses were too low for a significant gradient. An NH₃ capturing system was designed and tested in a 100-chicken broiler room. Five bell-type collecting devices were installed over the litter to collect NH₃ emissions. While the air extraction system moved only 10% of the total room ventilation airflow rate, the fraction of total ammonia removed was 18%, because of the higher concentration air taken from near the litter. The system demonstrated the potential to reduce emissions from broiler facilities and to concentrate the NH₃ effluent for use in an emission control system. In summary, the project laid a solid foundation for the implementation of both processes, and also resulted in a significant scientific contribution related to AF kinetic studies and ferrous analytical measurements.
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Hajarizadeh, Behzad, Jennifer MacLachlan, Benjamin Cowie, and Gregory J. Dore. Population-level interventions to improve the health outcomes of people living with hepatitis B: an Evidence Check brokered by the Sax Institute for the NSW Ministry of Health, 2022. The Sax Institute, August 2022. http://dx.doi.org/10.57022/pxwj3682.
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Background An estimated 292 million people are living with chronic hepatitis B virus (HBV) infection globally, including 223,000 people in Australia. HBV diagnosis and linkage of people living with HBV to clinical care is suboptimal in Australia, with 27% of people living with HBV undiagnosed and 77% not receiving regular HBV clinical care. This systematic review aimed to characterize population-level interventions implemented to enhance all components of HBV care cascade and analyse the effectiveness of interventions. Review questions Question 1: What population-level interventions, programs or policy approaches have been shown to be effective in reducing the incidence of hepatitis B; and that may not yet be fully rolled out or evaluated in Australia demonstrate early effectiveness, or promise, in reducing the incidence of hepatitis B? Question 2: What population-level interventions and/or programs are effective at reducing disease burden for people in the community with hepatitis B? Methods Four bibliographic databases and 21 grey literature sources were searched. Studies were eligible for inclusion if the study population included people with or at risk of chronic HBV, and the study conducted a population-level interventions to decrease HBV incidence or disease burden or to enhance any components of HBV care cascade (i.e., diagnosis, linkage to care, treatment initiation, adherence to clinical care), or HBV vaccination coverage. Studies published in the past 10 years (since January 2012), with or without comparison groups were eligible for inclusion. Studies conducting an HBV screening intervention were eligible if they reported proportion of people participating in screening, proportion of newly diagnosed HBV (participant was unaware of their HBV status), proportion of people received HBV vaccination following screening, or proportion of participants diagnosed with chronic HBV infection who were linked to HBV clinical care. Studies were excluded if study population was less than 20 participants, intervention included a pharmaceutical intervention or a hospital-based intervention, or study was implemented in limited clinical services. The records were initially screened by title and abstract. The full texts of potentially eligible records were reviewed, and eligible studies were selected for inclusion. For each study included in analysis, the study outcome and corresponding 95% confidence intervals (95%CIs) were calculated. For studies including a comparison group, odds ratio (OR) and corresponding 95%CIs were calculated. Random effect meta-analysis models were used to calculate the pooled study outcome estimates. Stratified analyses were conducted by study setting, study population, and intervention-specific characteristics. Key findings A total of 61 studies were included in the analysis. A large majority of studies (study n=48, 79%) included single-arm studies with no concurrent control, with seven (12%) randomised controlled trials, and six (10%) non-randomised controlled studies. A total of 109 interventions were evaluated in 61 included studies. On-site or outreach HBV screening and linkage to HBV clinical care coordination were the most frequent interventions, conducted in 27 and 26 studies, respectively. Question 1 We found no studies reporting HBV incidence as the study outcome. One study conducted in remote area demonstrated that an intervention including education of pregnant women and training village health volunteers enhanced coverage of HBV birth dose vaccination (93% post-intervention, vs. 81% pre-intervention), but no data of HBV incidence among infants were reported. Question 2 Study outcomes most relevant to the HBV burden for people in the community with HBV included, HBV diagnosis, linkage to HBV care, and HBV vaccination coverage. Among randomised controlled trials aimed at enhancing HBV screening, a meta-analysis was conducted including three studies which implemented an intervention including community face-to-face education focused on HBV and/or liver cancer among migrants from high HBV prevalence areas. This analysis demonstrated a significantly higher HBV testing uptake in intervention groups with the likelihood of HBV testing 3.6 times higher among those participating in education programs compared to the control groups (OR: 3.62, 95% CI 2.72, 4.88). In another analysis, including 25 studies evaluating an intervention to enhance HBV screening, a pooled estimate of 66% of participants received HBV testing following the study intervention (95%CI: 58-75%), with high heterogeneity across studies (range: 17-98%; I-square: 99.9%). A stratified analysis by HBV screening strategy demonstrated that in the studies providing participants with on-site HBV testing, the proportion receiving HBV testing (80%, 95%CI: 72-87%) was significantly higher compared to the studies referring participants to an external site for HBV testing (54%, 95%CI: 37-71%). In the studies implementing an intervention to enhance linkage of people diagnosed with HBV infection to clinical care, the interventions included different components and varied across studies. The most common component was post-test counselling followed by assistance with scheduling clinical appointments, conducted in 52% and 38% of the studies, respectively. In meta-analysis, a pooled estimate of 73% of people with HBV infection were linked to HBV clinical care (95%CI: 64-81%), with high heterogeneity across studies (range: 28-100%; I-square: 99.2%). A stratified analysis by study population demonstrated that in the studies among general population in high prevalence countries, 94% of people (95%CI: 88-100%) who received the study intervention were linked to care, significantly higher than 72% (95%CI: 61-83%) in studies among migrants from high prevalence area living in a country with low prevalence. In 19 studies, HBV vaccination uptake was assessed after an intervention, among which one study assessed birth dose vaccination among infants, one study assessed vaccination in elementary school children and 17 studies assessed vaccination in adults. Among studies assessing adult vaccination, a pooled estimate of 38% (95%CI: 21-56%) of people initiated vaccination, with high heterogeneity across studies (range: 0.5-93%; I square: 99.9%). A stratified analysis by HBV vaccination strategy demonstrated that in the studies providing on-site vaccination, the uptake was 78% (95%CI: 62-94%), significantly higher compared to 27% (95%CI: 13-42%) in studies referring participants to an external site for vaccination. Conclusion This systematic review identified a wide variety of interventions, mostly multi-component interventions, to enhance HBV screening, linkage to HBV clinical care, and HBV vaccination coverage. High heterogeneity was observed in effectiveness of interventions in all three domains of screening, linkage to care, and vaccination. Strategies identified to boost the effectiveness of interventions included providing on-site HBV testing and vaccination (versus referral for testing and vaccination) and including community education focussed on HBV or liver cancer in an HBV screening program. Further studies are needed to evaluate the effectiveness of more novel interventions (e.g., point of care testing) and interventions specifically including Indigenous populations, people who inject drugs, men who have sex with men, and people incarcerated.