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Letteratura scientifica selezionata sul tema "Biocement"

Autore: Grafiati
Pubblicato: 10 dicembre 2022
Ultima modifica: 28 gennaio 2023

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Articoli di riviste sul tema "Biocement"

1

DEAN, MARIA, JOHN WELCH, CASSIDY BRANDT e THOMAS TAUER. "Surface analyses of biocements from Pectinaria gouldii (Polychaeta: Pectinariidae) and Phragmatopoma lapidosa (Polychaeta: Sabellariidae)". Zoosymposia 2, n. 1 (31 agosto 2009): 329–37. http://dx.doi.org/10.11646/zoosymposia.2.1.23.

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Abstract (sommario):
Pectinaria gouldii and Phragmatopoma lapidosa are marine polychaetes that reside in protective structures built from sand grains bound together using proteinaceous cement secreted from specialized glands. P. gouldii constructs a solitary, ice-cream-cone-like structure. The smaller, gregarious P. lapidosa forms a large, reef-like mound. This study investigates the physical features of these two polychaete biocements, linking structure and function in two marine environments. The surface structures of hydrated biocement samples were analyzed using atomic force microscopy (AFM), and the surface structures and composition of dehydrated biocement samples were analyzed using scanning electron microscopy (SEM) and electron dispersive spectroscopy (EDS). Atomic force analyses indicate that (in their native states) the surface roughness, adhesion, and stiffness of P. gouldii biocement are greater than P. lapidosa biocement. The surface of P. gouldii resembled “cottage cheese,” while the surface of P. lapidosa had smoother features. SEM revealed “popped bubble” features that indicated a solid foam-like material for both biocements. EDS confirmed the presence of calcium, magnesium, and phosphorous in both biocements, with varying amounts of these three elements at different locations on the same sample.
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2

Hang, Lei, Enjie Yang, Yundong Zhou, Wenzhi Song e Jia He. "Microbially Induced Calcite Precipitation (MICP) for Stabilization of Desert Sand against the Wind-induced Erosion: A Parametric Study". Sustainability 14, n. 18 (11 settembre 2022): 11409. http://dx.doi.org/10.3390/su141811409.

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Abstract (sommario):
Biocementation, based on microbially induced calcite precipitation (MICP), is a novel soil improvement method, which can form a cemented layer on the surface of desert sand to resist wind-induced erosion. In this work, the surface penetration resistance test and wind tunnel test were conducted to evaluate the various influential factors for the resistance of biocemented desert sand to wind-induced erosion, including the treatment factors, such as treatment temperature and biocement solution concentration, and durability factors such as the development of time, freezing–thawing cycles, and drying–wetting cycles. The test results demonstrated that the erosion resistance of biocemented desert sand was improved by the increase of treatment temperature and the concentration of biocement solution, which was manifested in the increase of surface penetration resistance of biocemented samples. In addition, the resistance of biocemented desert sand to wind-induced erosion decreased with the increased number of drying–wetting cycles, to lesser extents, with the development of time and the increased number of freezing–thawing cycles.
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3

Štulajterová, R., L. Medvecký, M. Giretová, T. Sopčák e J. Briančin. "Influence of Sodium Alginate on Properties of Tetracalcium Phosphate/Nanomonetite Biocement". Powder Metallurgy Progress 19, n. 1 (1 settembre 2019): 1–11. http://dx.doi.org/10.1515/pmp-2019-0001.

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Abstract (sommario):
AbstractThe tetracalcium phosphate/nanomonetite (TTCPMH) biocements with the addition of sodium alginate were prepared by mechanical homogenization of powder mixture with hardening liquid containing sodium alginate. The effect of various viscosity of different alginates on properties of TTCPMH cement mixture was investigated. The medium viscous (MED) alginate had a more negative effect on setting process and compressive strength than low viscous (LOW) alginate. An approx. 50% decrease in mechanical properties (compressive strengths, Young´s modulus, work of fracture (WOF)) was revealed after an addition of 0.25 wt % with rapid fall above 1 wt % of LOW alginate in biocement. A statistically significant difference in the WOF was found between of 0.25 and 0.5 LOW alginate biocements (p<0.035) whereas no statistical differences were revealed between WOF of 0.5 and 1 LOW alginate biocements (p˃0.357). In the microstructure of composite cements, the increased amounts of granular or finer needle-like nanohydroxyapatite particles arranged into the form of more separated spherical agglomerates were observed. A low cytotoxicity of cement extracts based on measurement of cell proliferation was revealed.
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4

Chu, Jian, Volodymyr Ivanov, Viktor Stabnikov, Jia He, Bing Li e Maryam Naemi. "Biocement: Green Building- and Energy-Saving Material". Advanced Materials Research 347-353 (ottobre 2011): 4051–54. http://dx.doi.org/10.4028/www.scientific.net/amr.347-353.4051.

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Abstract (sommario):
Cement and chemical grouts have often been used for soil strengthening. However, high cost, energy consumption, and harm to environment restrict their applications. Biocement could be a new green building- material and energy-saving material. Biocement is a mixture of enzymes or microbial biomass with inorganic chemicals, which can be produced from cheap raw materials. Supply of biocementing solution to the porous soil or mixing of dry biocement with clayey soil initiate biocementation of soil due to specific enzymatic activity. Different microorganisms and enzymes can be used for production of biocement.
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5

Gao, Yaqing, Chen Hua e Tong Ke. "Field Test on Soybean-Urease Induced Calcite Precipitation (SICP) for Desert Sand Stabilization against the Wind-Induced Erosion". Sustainability 14, n. 22 (21 novembre 2022): 15474. http://dx.doi.org/10.3390/su142215474.

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Abstract (sommario):
Soybean-urease induced calcite precipitation (SICP) is an effective method for the improvement of sand, which forms a biocemented layer on the desert sand surface to resist erosion induced by the wind. Under this study, field tests were carried out to determine how the SICP approach may enhance the resistance of the desert to wind-induced erosion and the durability of SICP treatment in southeastern margin of Tengger Desert, Ningxia Hui Autonomous Region, China. The experimental results demonstrated that the erosion resistance of desert sand was significantly enhanced due to the SICP treatment, and the improvement effect was enhanced with the increase of the biocement solution concentration and dosage and the number of treatment cycles. Furthermore, it was also found that the resistance of SICP-treated sand to erosion induced by the wind reduced as the development of time reduced. Based on the test results in this paper, larger biocement solution concentration and dosage and multiple treatment cycles are proposed in the areas where severe wind-induced erosion takes place in order to improve the ductility of SICP treatment.
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6

Franczak, Priscila Ferraz, Nelson Heriberto Almeida Camargo, Nelson Levandowski e Daiara Floriano da Silva. "Synthesis and Characterization of Three Hydrated Calcium Phosphates Used as Biocement Precursors". Advanced Materials Research 936 (giugno 2014): 712–16. http://dx.doi.org/10.4028/www.scientific.net/amr.936.712.

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Abstract (sommario):
Calcium phosphates biocements are biomaterials that present crystallographic and mineralogical characteristics similar to human skeletal structure. This has led to the development of new calcium phosphates biomaterials for biomedical applications, especially biomaterials for repairing defects and bone reconstruction. Calcium phosphates biocements are a promising alternative in biomedical applications, for they are easy to mold, they have good wettability, hydration and hardening capacity during its application in biological environment. This work aimed at the synthesis of hydrated calcium phosphates powder, precursor to late biocements development. Three calcium phosphates compositions were produced via CaCO3/phosphoric acid reactive method in the ratios Ca/P = 1,5; 1,6 e 1,67 molar. The presented results are associated to hydrated powder morphology and synthesis process control. Field Electronic Microscope helped with the morphological characterization of the powders, Fourier Transformed Infrared Spectroscopy (FTIR) gave support to the identification of H2O e PO43- grouping vibrational bands and x-ray diffractometry (XRD) served on crystallographic characterization of hydrated calcium phosphates. The work showed that for the different powder compositions the hydrated calcium phosphate phase is formed by clustered fine particles. This demonstrated that the chosen synthesis method permits the obtaining nanoparticles of hydrated calcium phosphates, precursors for later biocement production.
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7

Yin, Jie, Jian-Xin Wu, Ke Zhang, Mohamed A. Shahin e Liang Cheng. "Comparison between MICP-Based Bio-Cementation Versus Traditional Portland Cementation for Oil-Contaminated Soil Stabilisation". Sustainability 15, n. 1 (27 dicembre 2022): 434. http://dx.doi.org/10.3390/su15010434.

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Abstract (sommario):
In recent years, oil spills and leakages have often occurred during oil exploration, transportation, handling, usage, and processing, causing serious global environmental problems. Microbially-induced carbonate precipitation (MICP) is an emerging green, environmentally friendly, and sustainable technology that has proven to be a promising alternative for soil stabilisation. This paper provides a comparison between the mechanical performance of oil-polluted sand treated with biocement and traditional Portland cement. A series of laboratory tests, including permeability, unconfined compressive strength (UCS), and triaxial consolidated undrained (CU) tests, was conducted. Even though oil contamination deteriorates the bonding strength of treated soil for both biocement and Portland cement soils, the biocement-treated oil-contaminated sand was found to achieve higher strength (up to four times) than cement-treated soil in the presence of similar content of cementing agent. After eight treatment cycles, the UCS value of oil-contaminated sand treated with biocement reached 1 MPa, demonstrating a high potential for oil-contaminated soil stabilisation in regions of oil spills and leakages.
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8

Lee, Chungmin, Hyesun Lee e Ok Kim. "Biocement Fabrication and Design Application for a Sustainable Urban Area". Sustainability 10, n. 11 (7 novembre 2018): 4079. http://dx.doi.org/10.3390/su10114079.

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Abstract (sommario):
Recently, designers have begun to pursue sustainability through the fabrication of materials from living organisms such as bacteria, fungi, and algae in order to address environmental issues. Based on the potential of materials from living organisms, this study has explored a sustainable design application using biocement formed thorough microbially-induced calcite precipitation (MICP), which produces minerals by bacterial metabolic activity. Since most of the studies on MICP thus far have focused on limited fields such as engineering, biotechnology, and geo-technology, this study has focused more on improving the application of biocement in design. We optimized MICP conditions using two parameters (i.e., concentration of urea-CaCl2 and bacterial cell density) through water percolation testing, compressive strength testing, and X-ray diffraction (XRD) analysis. Then, based on the optimized conditions, material compatibility testing and scalability testing were performed, and design application research was conducted as well. As a result, biocement has been identified as a potential sustainable design material, based on its 40% compressive strength compared to conventional concrete, improved material finish, aesthetic aspects, and environmental impact. This paper contributes to the development of biocement applications in the environmental design field through multidisciplinary research ranging from biological experiments to design applications.
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9

Jebamalar, J., e Priya Iyer. "Production of Biocement from Microalgae". International Journal of Current Research in Biosciences and Plant Biology 3, n. 1 (6 gennaio 2016): 122–26. http://dx.doi.org/10.20546/ijcrbp.2016.301.013.

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10

Cox, Sophie C., Sarika Patel, Uwe Gbureck, Adrian J. Wright e Liam M. Grover. "A cohesive premixed monetite biocement". Journal of the American Ceramic Society 100, n. 3 (30 dicembre 2016): 1241–49. http://dx.doi.org/10.1111/jace.14699.

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Più fonti

Tesi sul tema "Biocement"

1

au, vicky whiffin@sydneywater com, e Victoria S. Whiffin. "Microbial CaCO3 precipitation for the production of biocement". Murdoch University, 2004. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20041101.142604.

Testo completo
Abstract (sommario):
The hydrolysis of urea by the widely distributed enzyme urease is special in that it is one of the few biologically occurring reactions that can generate carbonate ions without an associated production of protons. When this hydrolysis occurs in a calcium-rich environment, calcite (calcium carbonate) precipitates from solution forming a solid-crystalline material. The binding strength of the precipitated crystals is highly dependent on the rate of carbonate formation and under suitable conditions it is possible to control the reaction to generate hard binding calcite cement (or Biocement). The objective of this thesis was to develop an industrially suitable cost-effective microbial process for the production of urease active cells and investigate the potential for urease active cells to act as a catalyst for the production of Biocement. The biocementation capability of two suitable strains was compared. Sporosarcina pasteurii (formally Bacillus pasteurii) produced significantly higher levels of urease activity compared to Proteus vulgaris, however the level of urease activity was variable with respect to biomass suggesting that the enzyme was not constitutive as indicated by the literature, but subject to regulation. The environmental and physiological conditions for maximum urease activity in S. pasteurii were investigated and it was found that the potential urease capacity of the organism was very high (29 mM urea.min-1.OD-1) and sufficient for biocementation without additional processing (e.g. concentration, cell lysis). The regulation mechanism for S. pasteurii urease was not fully elucidated in this study, however it was shown that low specific urease activity was not due to depletion of urea nor due to the high concentrations of the main reaction product, ammonium. pH conditions were shown to have a regulatory effect on urease but it was evident that another co-regulating mechanism existed. Despite not fully exploiting the urease capability of S. pasteurii, sufficient urease activity to allow direct application of the enzyme without additional processing could still be achieved and the organism was considered suitable for biocementation. Urease was the most expensive component of the cementation process and cost-efficient production was desired, thus an economic growth procedure was developed for large-scale cultivation of S. pasteurii. The organism is a moderate alkaliphile (growth optimum pH 9.25) and it was shown that sufficient activity for biocementation could be cultivated in non-sterile conditions with a minimum of upstream and downstream processing. The cultivation medium was economised and expensive components were replace with a food-grade protein source and acetate, which lowered production costs by 95%. A high level of urease activity (21 mM urea hydrolysed.min-1) was produced in the new medium at a low cost ($0.20 (AUD) per L). The performance of urease in whole S. pasteurii cells was evaluated under biocementation conditions (i.e. presence of high concentrations of urea, Ca2+, NH4 +/NH3, NO3 - and Cl- ions). It was established that the rate of urea hydrolysis was not constant during cementation, but largely controlled by the external concentrations of urea and calcium, which constantly changed during cementation due to precipitation of solid calcium carbonate from the system. A simple model was generated that predicted the change in urea hydrolysis rate over the course of cementation. It was shown that whole cell S. pasteurii urease was tolerant to concentrations of up to 3 M urea and 2 M calcium, and the rate of urea hydrolysis was unaffected up to by 3 M ammonium. This allowed the controlled precipitation of up to 1.5 M CaCO3 within one treatment, and indicated that the enzyme was very stable inspite of extreme chemical conditions. A cost-efficient cementation procedure for the production of high cementation strength was developed. Several biocementation trials were conducted into order to optimise the imparted cementation strength by determining the effect of urea hydrolysis rate on the development of strength. It was shown that high cementation strength was produced at low urea hydrolysis rates and that the development of cementation strength was not linear over the course of the reaction but mostly occurred in the first few hours of the reaction. In addition, the whole cell bacterial enzyme had capacity to be immobilised in the cementation material and re-used to subsequent applications, offering a significant cost-saving to the process. An industry-sponsored trial was undertaken to investigate the effectiveness of Biocement for increasing in-situ strength and stiffness of two different sandy soils; (a) Koolschijn sand and (b) 90% Koolschijn sand mixed with 10% peat (Holland Veen). After biocementation treatment, Koolschijn sand indicated a shear strength of 1.8 MPa and a stiffness of 250 MPa, which represents an 8-fold and 3-fold respective improvement in strength compared to unconsolidated sand. Significantly lower strength improvements were observed in sand mixed with peat. In combination, trials of producing bacteria under economically acceptable conditions and cementation trials support the possibility of on-site production and in-situ application of large field applications.
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2

Whiffin, Victoria S. "Microbial CaCO₃ precipitation for the production of biocement /". Access via Murdoch University Digital Theses Project, 2004. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20041101.142604.

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3

Whiffin, Victoria S. "Microbial CaCO3 precipitation for the production of biocement". Thesis, Whiffin, Victoria S. (2004) Microbial CaCO3 precipitation for the production of biocement. PhD thesis, Murdoch University, 2004. https://researchrepository.murdoch.edu.au/id/eprint/399/.

Testo completo
Abstract (sommario):
The hydrolysis of urea by the widely distributed enzyme urease is special in that it is one of the few biologically occurring reactions that can generate carbonate ions without an associated production of protons. When this hydrolysis occurs in a calcium-rich environment, calcite (calcium carbonate) precipitates from solution forming a solid-crystalline material. The binding strength of the precipitated crystals is highly dependent on the rate of carbonate formation and under suitable conditions it is possible to control the reaction to generate hard binding calcite cement (or Biocement). The objective of this thesis was to develop an industrially suitable cost-effective microbial process for the production of urease active cells and investigate the potential for urease active cells to act as a catalyst for the production of Biocement. The biocementation capability of two suitable strains was compared. Sporosarcina pasteurii (formally Bacillus pasteurii) produced significantly higher levels of urease activity compared to Proteus vulgaris, however the level of urease activity was variable with respect to biomass suggesting that the enzyme was not constitutive as indicated by the literature, but subject to regulation. The environmental and physiological conditions for maximum urease activity in S. pasteurii were investigated and it was found that the potential urease capacity of the organism was very high (29 mM urea.min-1.OD-1) and sufficient for biocementation without additional processing (e.g. concentration, cell lysis). The regulation mechanism for S. pasteurii urease was not fully elucidated in this study, however it was shown that low specific urease activity was not due to depletion of urea nor due to the high concentrations of the main reaction product, ammonium. pH conditions were shown to have a regulatory effect on urease but it was evident that another co-regulating mechanism existed. Despite not fully exploiting the urease capability of S. pasteurii, sufficient urease activity to allow direct application of the enzyme without additional processing could still be achieved and the organism was considered suitable for biocementation. Urease was the most expensive component of the cementation process and cost-efficient production was desired, thus an economic growth procedure was developed for large-scale cultivation of S. pasteurii. The organism is a moderate alkaliphile (growth optimum pH 9.25) and it was shown that sufficient activity for biocementation could be cultivated in non-sterile conditions with a minimum of upstream and downstream processing. The cultivation medium was economised and expensive components were replace with a food-grade protein source and acetate, which lowered production costs by 95%. A high level of urease activity (21 mM urea hydrolysed.min-1) was produced in the new medium at a low cost ($0.20 (AUD) per L). The performance of urease in whole S. pasteurii cells was evaluated under biocementation conditions (i.e. presence of high concentrations of urea, Ca2+, NH4 +/NH3, NO3 - and Cl- ions). It was established that the rate of urea hydrolysis was not constant during cementation, but largely controlled by the external concentrations of urea and calcium, which constantly changed during cementation due to precipitation of solid calcium carbonate from the system. A simple model was generated that predicted the change in urea hydrolysis rate over the course of cementation. It was shown that whole cell S. pasteurii urease was tolerant to concentrations of up to 3 M urea and 2 M calcium, and the rate of urea hydrolysis was unaffected up to by 3 M ammonium. This allowed the controlled precipitation of up to 1.5 M CaCO3 within one treatment, and indicated that the enzyme was very stable inspite of extreme chemical conditions. A cost-efficient cementation procedure for the production of high cementation strength was developed. Several biocementation trials were conducted into order to optimise the imparted cementation strength by determining the effect of urea hydrolysis rate on the development of strength. It was shown that high cementation strength was produced at low urea hydrolysis rates and that the development of cementation strength was not linear over the course of the reaction but mostly occurred in the first few hours of the reaction. In addition, the whole cell bacterial enzyme had capacity to be immobilised in the cementation material and re-used to subsequent applications, offering a significant cost-saving to the process. An industry-sponsored trial was undertaken to investigate the effectiveness of Biocement for increasing in-situ strength and stiffness of two different sandy soils; (a) Koolschijn sand and (b) 90% Koolschijn sand mixed with 10% peat (Holland Veen). After biocementation treatment, Koolschijn sand indicated a shear strength of 1.8 MPa and a stiffness of 250 MPa, which represents an 8-fold and 3-fold respective improvement in strength compared to unconsolidated sand. Significantly lower strength improvements were observed in sand mixed with peat. In combination, trials of producing bacteria under economically acceptable conditions and cementation trials support the possibility of on-site production and in-situ application of large field applications.
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4

Whiffin, Victoria S. "Microbial CaCO3 precipitation for the production of biocement". Whiffin, Victoria S. (2004) Microbial CaCO3 precipitation for the production of biocement. PhD thesis, Murdoch University, 2004. http://researchrepository.murdoch.edu.au/399/.

Testo completo
Abstract (sommario):
The hydrolysis of urea by the widely distributed enzyme urease is special in that it is one of the few biologically occurring reactions that can generate carbonate ions without an associated production of protons. When this hydrolysis occurs in a calcium-rich environment, calcite (calcium carbonate) precipitates from solution forming a solid-crystalline material. The binding strength of the precipitated crystals is highly dependent on the rate of carbonate formation and under suitable conditions it is possible to control the reaction to generate hard binding calcite cement (or Biocement). The objective of this thesis was to develop an industrially suitable cost-effective microbial process for the production of urease active cells and investigate the potential for urease active cells to act as a catalyst for the production of Biocement. The biocementation capability of two suitable strains was compared. Sporosarcina pasteurii (formally Bacillus pasteurii) produced significantly higher levels of urease activity compared to Proteus vulgaris, however the level of urease activity was variable with respect to biomass suggesting that the enzyme was not constitutive as indicated by the literature, but subject to regulation. The environmental and physiological conditions for maximum urease activity in S. pasteurii were investigated and it was found that the potential urease capacity of the organism was very high (29 mM urea.min-1.OD-1) and sufficient for biocementation without additional processing (e.g. concentration, cell lysis). The regulation mechanism for S. pasteurii urease was not fully elucidated in this study, however it was shown that low specific urease activity was not due to depletion of urea nor due to the high concentrations of the main reaction product, ammonium. pH conditions were shown to have a regulatory effect on urease but it was evident that another co-regulating mechanism existed. Despite not fully exploiting the urease capability of S. pasteurii, sufficient urease activity to allow direct application of the enzyme without additional processing could still be achieved and the organism was considered suitable for biocementation. Urease was the most expensive component of the cementation process and cost-efficient production was desired, thus an economic growth procedure was developed for large-scale cultivation of S. pasteurii. The organism is a moderate alkaliphile (growth optimum pH 9.25) and it was shown that sufficient activity for biocementation could be cultivated in non-sterile conditions with a minimum of upstream and downstream processing. The cultivation medium was economised and expensive components were replace with a food-grade protein source and acetate, which lowered production costs by 95%. A high level of urease activity (21 mM urea hydrolysed.min-1) was produced in the new medium at a low cost ($0.20 (AUD) per L). The performance of urease in whole S. pasteurii cells was evaluated under biocementation conditions (i.e. presence of high concentrations of urea, Ca2+, NH4 +/NH3, NO3 - and Cl- ions). It was established that the rate of urea hydrolysis was not constant during cementation, but largely controlled by the external concentrations of urea and calcium, which constantly changed during cementation due to precipitation of solid calcium carbonate from the system. A simple model was generated that predicted the change in urea hydrolysis rate over the course of cementation. It was shown that whole cell S. pasteurii urease was tolerant to concentrations of up to 3 M urea and 2 M calcium, and the rate of urea hydrolysis was unaffected up to by 3 M ammonium. This allowed the controlled precipitation of up to 1.5 M CaCO3 within one treatment, and indicated that the enzyme was very stable inspite of extreme chemical conditions. A cost-efficient cementation procedure for the production of high cementation strength was developed. Several biocementation trials were conducted into order to optimise the imparted cementation strength by determining the effect of urea hydrolysis rate on the development of strength. It was shown that high cementation strength was produced at low urea hydrolysis rates and that the development of cementation strength was not linear over the course of the reaction but mostly occurred in the first few hours of the reaction. In addition, the whole cell bacterial enzyme had capacity to be immobilised in the cementation material and re-used to subsequent applications, offering a significant cost-saving to the process. An industry-sponsored trial was undertaken to investigate the effectiveness of Biocement for increasing in-situ strength and stiffness of two different sandy soils; (a) Koolschijn sand and (b) 90% Koolschijn sand mixed with 10% peat (Holland Veen). After biocementation treatment, Koolschijn sand indicated a shear strength of 1.8 MPa and a stiffness of 250 MPa, which represents an 8-fold and 3-fold respective improvement in strength compared to unconsolidated sand. Significantly lower strength improvements were observed in sand mixed with peat. In combination, trials of producing bacteria under economically acceptable conditions and cementation trials support the possibility of on-site production and in-situ application of large field applications.
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5

Schamel, Martha [Verfasser], Jürgen Gutachter] Groll e Michael [Gutachter] [Gelinsky. "Novel dual setting approaches for mechanically reinforced mineral biocements / Martha Schamel [geb. Geffers] ; Gutachter: Jürgen Groll, Michael Gelinsky". Würzburg : Universität Würzburg, 2017. http://d-nb.info/1144862736/34.

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6

Schamel, Martha Verfasser], Jürgen [Gutachter] Groll e Michael [Gutachter] [Gelinsky. "Novel dual setting approaches for mechanically reinforced mineral biocements / Martha Schamel [geb. Geffers] ; Gutachter: Jürgen Groll, Michael Gelinsky". Würzburg : Universität Würzburg, 2017. http://d-nb.info/1144862736/34.

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7

Cabrera, Arenas Juan Carlos. "Estudio de prefactibilidad para la instalación de una planta productora de biocemento a partir de ceniza de cascarilla de arroz". Bachelor's thesis, Chiclayo, 2015. http://tesis.usat.edu.pe/jspui/handle/123456789/519.

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Abstract (sommario):
La Industria cementera es el punto de partida de esta investigación, la cual tiene una gran cantidad de demanda en el mundo, incluyendo Perú. Esta Industria tiene como residuo principal la cascarilla de arroz, la cual se utiliza como material combustible en múltiples Industrias, ya que permite disminuir la emisión de CO2 proveniente de la quema de combustibles fósiles. La Ceniza de la Cascarilla de Arroz CCA) es el residuo sólido de cualquier transformación termoquímica (en nuestro caso combustión) y su uso como materia prima o insumo es el objeto de estudio de esta investigación. Como objetivo se tiene realizar: un estudio oferta y demanda del Bio – cemento para lograr confirmar que el proyecto tiene un nicho en el mercado, un estudio oferta y demanda de la cascarilla de arroz y demás insumos para confirmar que existe disponibilidad de los mismos (caliza, arcilla, yeso y cascarilla de arroz), establecer indicadores de sostenibilidad ambiental del proyecto con la finalidad de prevenir la posible contaminación del medio ambiente, realizar Diseño de Planta para la elaboración de Fabricación de Bio - cemento y realizar una Evaluación Económica Financiera del Proyecto para la viabilidad del proyecto, la cual es aceptable. El proyecto de prefactibilidad para instalación de una planta productora de Bio - cemento a partir de ceniza de cascarilla de arroz para la Región Lambayeque colaborará con el desarrollo, disminuirá la contaminación al ambiente y sus habitantes; además con la presente investigación se le busca utilidad a los residuos Agroindustriales de las arroceras (entre otras) que con el tiempo siguen creciendo.
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8

Cabrera, Arenas Juan Carlos, e Arenas Juan Carlos Cabrera. "Estudio de prefactibilidad para la instalación de una planta productora de biocemento a partir de ceniza de cascarilla de arroz". Bachelor's thesis, Universidad Católica Santo Toribio de Mogrovejo, 2015. http://tesis.usat.edu.pe/handle/usat/485.

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La Industria cementera es el punto de partida de esta investigación, la cual tiene una gran cantidad de demanda en el mundo, incluyendo Perú. Esta Industria tiene como residuo principal la cascarilla de arroz, la cual se utiliza como material combustible en múltiples Industrias, ya que permite disminuir la emisión de CO2 proveniente de la quema de combustibles fósiles. La Ceniza de la Cascarilla de Arroz CCA) es el residuo sólido de cualquier transformación termoquímica (en nuestro caso combustión) y su uso como materia prima o insumo es el objeto de estudio de esta investigación. Como objetivo se tiene realizar: un estudio oferta y demanda del Bio – cemento para lograr confirmar que el proyecto tiene un nicho en el mercado, un estudio oferta y demanda de la cascarilla de arroz y demás insumos para confirmar que existe disponibilidad de los mismos (caliza, arcilla, yeso y cascarilla de arroz), establecer indicadores de sostenibilidad ambiental del proyecto con la finalidad de prevenir la posible contaminación del medio ambiente, realizar Diseño de Planta para la elaboración de Fabricación de Bio - cemento y realizar una Evaluación Económica Financiera del Proyecto para la viabilidad del proyecto, la cual es aceptable. El proyecto de prefactibilidad para instalación de una planta productora de Bio - cemento a partir de ceniza de cascarilla de arroz para la Región Lambayeque colaborará con el desarrollo, disminuirá la contaminación al ambiente y sus habitantes; además con la presente investigación se le busca utilidad a los residuos Agroindustriales de las arroceras (entre otras) que con el tiempo siguen creciendo.
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Franczak, Priscila Ferraz. "Síntese e caracterização de biocimentos de fosfatos de cálcio para uso na reparação do tecido ósseo". Universidade do Estado de Santa Catarina, 2014. http://tede.udesc.br/handle/handle/1659.

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Made available in DSpace on 2016-12-08T17:19:23Z (GMT). No. of bitstreams: 1 Priscila Ferraz Franczak.pdf: 3194066 bytes, checksum: 4e95079e48ade5fa359cd79ef4d41ea0 (MD5) Previous issue date: 2014-07-18
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Calcium phosphate biocements are biomaterials that present similar crystallographic structure to the human skeleton, and they are used in biomedical applications, particularly in defects repair, bone reconstruction and attachment of implants. They are promising in biomedical applications by their easy molding, good wettability, hydration and hardening ability during their application in biological means. Interest in calcium phosphate biocements is associated with properties of bioactivity, biocompatibility and crystallographic similarity to bone apatite. This study aimed at the preparation and characterization of hydrated calcium phosphates nanostructured powders in the ratios Ca/P = 1.5; 1.55; 1.6; 1.67; 1.7 molar and biphasic compositions with 1% MgO and 5% Al2O3-α. These powders were treated at 1300ºC/2h, providing biocements. Investigations were performed by scanning electron microscopy (SEM), X-ray diffraction (XRD), particle size analysis by the Scherrer theoretical method and the laser diffraction method. Infrared spectroscopy and chemical analysis served as a support. It was found about the obtained results that biocements are formed by fine morphologies of calcium phosphate crystal fragments. Another observation was that the presence of second phase inhibited calcium phosphate crystals coalescence during heat treatment, leading to fine crystals formation, favoring the increase of biocement surface area. Biphasic compositions hydration tests manteined microporosity and gel formation at the crystals edges, indicating that biphasic compositions are promising as biomaterial replacement and anchoring in biomedical applications.
Os biocimentos de fosfato de cálcio são biomateriais que apresentam características cristalográficas semelhantes as da estrutura do esqueleto humano, sendo utilizados em aplicações biomédicas na reparação de defeitos, reconstrução óssea e fixação de implantes. São promissores por apresentarem facilidade de moldagem, boa molhabilidade, hidratação e capacidade de endurecimento durante sua aplicação em meios biológicos. O interesse pelos biocimentos de fosfatos de cálcio está associado às características de bioatividade, biocompatibilidade e semelhança cristalográfica com a apatita óssea. Esse trabalho teve como objetivo a elaboração e caracterização de pós nanoestruturados de fosfatos de cálcio hidratados nas razões Ca/P = 1,5; 1,55; 1,6; 1,67; 1,7 molar e composições bifásicas com 1% de MgO e 5% de Al2O3-α. Estes posteriormente foram tratados a temperatura de 1300ºC/2h fornecendo os biocimentos. As investigações foram realizadas através da microscopia eletrônica de varredura (MEV), difratometria de raios-X (DRX), análise do tamanho de partícula pelo método teórico de Scherrer e pelo método de difração a laser. A espectroscopia de infravermelho e a análise por fluorescência de raios X serviram de apoio na avaliação química. Constatou-se nos resultados obtidos que os biocimentos são formados por morfologias de finos fragmentos de cristais de fosfatos de cálcio. Outra observação foi que a presença de uma segunda fase inibiu a coalescência dos cristais de fosfatos de cálcio durante o tratamento térmico, levando a formação de finos cristais, favorecendo o aumento da área superficial do biocimento. Nos testes de hidratação as composições bifásicas mantiveram a microporosidade e apresentaram a formação de gel nos contornos dos cristais, indicando que as composições bifásicas são promissoras como biomaterial de substituição e ancoragem em aplicações biomédicas.
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Wu, Fan. "Development of biocomposite scaffolds and injectable biocement for bone regeneration". Thesis, 2013. http://hdl.handle.net/2440/80624.

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To repair massive bone defects caused by disease and trauma, a bone grafting procedure is required. The limitations associated with the use of autografts (tissue grafts from one point to another of the same individual's body) and allografts (tissue grafts between genetically nonidentical individuals) have boosted the research and development of bone graft substitutes. Calcium phosphate cement (CPC) is a promising bone graft substitute because of its bioactivity, osteoconductivity and bone replacement capability. However, difficulties with injectability and slow resorption rate have limited the wider applications of CPC. To overcome these limitations, premixed and injectable calcium deficient apatite biocement (cd-AB) were prepared in the initial phase of this study. Using a non-aqueous solution as the liquid phase, the resulting premixed cd-AB had the advantage of remaining stable in the syringe and only hardened following delivery to the defect site. As well, when injected into an aqueous environment, this premixed cd-AB exhibited improved washout resistance when compared to the conventional cd-AB using water as the liquid phase. However, the premixed cd-AB required a longer setting time and developed a reduced compressive strength compared to the conventional cd-AB. The hydration products of premixed cd-AB were a mixture of calcium deficient hydroxyapatite (cd-HA) and PLA. In vitro Tris-HCl immersion tests demonstrated that the premixed cd-AB was degradable. The results revealed that the premixed cd-AB was cytocompatible and no adverse effects were observed after attachment and proliferation of MG-63 osteoblast-like cells in vitro. The most distinct advantages of premixed and injectable PLA-modified cd-AB were its excellent washout resistance and in vitro degradability, suggesting that it may be a promising candidate for future bone reconstruction. In recent years, bone tissue engineering has emerged as a promising approach for the repair of bone damage and defects. In this approach, a scaffold is normally used alone or in combination with growth factors and/or cells to guide bone regeneration. Among the synthetic polymers used as scaffold materials, poly(ε-caprolactone) (PCL) has been widely used given its excellent biocompatibility and ease of processing. However, the use of PCL scaffolds is limited as a consequence of potential drawbacks including a slow degradation rate and their hydrophobic surface. These disadvantages may be overcome by incorporating additional natural polymer or inorganic fillers into the PCL matrix. In the second section of this study, porous scaffolds of zein/PCL biocomposite were fabricated and characterized. These scaffolds were prepared using the particulate leaching method with sodium chloride particles as porogen. Porous biocomposite scaffolds with porosity around 70% and well-interconnected network were obtained. The incorporation of zein into PCL led to an improvement of the surface hydrophilicity as confirmed by the results of water contact angle measurement. Following immersion in a phosphate buffered saline solution (PBS) in vitro for 28 days, it was observed that the zein/PCL scaffolds degraded more rapidly than the PCL scaffolds and the degradation rate could be controlled by adjusting the amount of zein in the composite. These results demonstrated the potential of the zein/PCL biocomposite scaffolds to be exploited in tissue engineering strategies for the repair of bone defects. In the final section of this study, porous scaffolds using a magnesium phosphate (MP)/PCL biocomposite were developed for bone tissue engineering applications. The composite scaffolds were fabricated by the particulate leaching method again using sodium chloride particles as porogen. The resulting scaffolds had interconnected macroporous structure with porosity around 73%. The surface hydrophilicity of the scaffolds was enhanced by the incorporation of MP component and confirmed by water contact angle measurement. The results from subsequent in vitro degradation experiments showed that the MP/PCL composite scaffolds degraded faster than PCL scaffolds in a PBS solution. An additional benefit was that the degradation rate of the scaffolds could be tuned by adjusting the content of MP component in the composite. These results indicated that the MP/PCL composite scaffolds have potential application in bone tissue engineering.
Thesis (Ph.D.) -- University of Adelaide, School of Chemical Engineering, 2013
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Capitoli di libri sul tema "Biocement"

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El Enshasy, Hesham, Daniel Joe Dailin, Roslinda Abd Malek, Nurul Zahidah Nordin, Ho Chin Keat, Jennifer Eyahmalay, Santosh Ramchuran, Jimmy Ngow Chee Ghong, Veshara Malapermal Ramdas e Rajesh Lalloo. "Biocement: A Novel Approach in the Restoration of Construction Materials". In Microbial Biotechnology Approaches to Monuments of Cultural Heritage, 177–98. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-3401-0_10.

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Ehrlich, Hermann. "Biocements". In Marine Biological Materials of Invertebrate Origin, 247–54. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-319-92483-0_21.

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Naeimi, Maryam, e Abdolhosein Haddad. "Investigation on the Environmental Impact of Soil Improvement Techniques: Comparison of Cement Grouting and Biocement". In Proceedings of GeoShanghai 2018 International Conference: Geoenvironment and Geohazard, 483–90. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-13-0128-5_53.

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Achal, Varenyam. "The Practical Use of Biocement as Self-healing Agent and in Construction Requires a Socio-Ecological Approach". In Building Materials for Sustainable and Ecological Environment, 1–8. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-1706-5_1.

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Ivanov, Volodymyr, e Viktor Stabnikov. "Biocementation and Biocements". In Construction Biotechnology, 109–38. Singapore: Springer Singapore, 2016. http://dx.doi.org/10.1007/978-981-10-1445-1_7.

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Anderson, Kevin C. "Cemented, Biocemented, and Cementless Total Ankle Replacement Fixation Methods". In Primary and Revision Total Ankle Replacement, 85–92. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-69269-8_8.

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Wang, Yang, Hanlong Liu, Zhichao Zhang, Peng Xiao, Xiang He e Yang Xiao. "Study on Low-Strength Biocemented Sands Using a Temperature-Controlled MICP (Microbially Induced Calcite Precipitation) Method". In Sustainable Civil Infrastructures, 15–26. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-95771-5_2.

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Reddy, Mondem S., e Sumit Joshi. "Carbon dioxide sequestration on biocement-based composites". In Carbon Dioxide Sequestration in Cementitious Construction Materials, 225–43. Elsevier, 2018. http://dx.doi.org/10.1016/b978-0-08-102444-7.00010-1.

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Waghmode, Meghmala S., Aparna B. Gunjal, Namdeo N. Bhujbal, Neha N. Patil e Neelu N. Nawani. "Eco-Friendly Construction". In Reusable and Sustainable Building Materials in Modern Architecture, 80–92. IGI Global, 2019. http://dx.doi.org/10.4018/978-1-5225-6995-4.ch004.

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Increase in urbanization leads to more construction of houses, dams, and streets. Reduction of the global warming effects can be carried out by recycling of construction material and searching for eco-friendly construction material. Greenhouse gas emissions can be reduced with the help of construction material which requires less energy for their production. The concept of eco-friendly construction is based on biomimetic (i.e., finding natural material with potential of endurance and self-cleaning properties). Construction materials like Portland cement and concrete can be replaced by eco-friendly biocement and bioconcrete. Production of biocement and bioconcrete can be done by using plants, algae, and bacteria. Use of less cement in concrete leads to less pollution. Concrete is the mixture of cement, sand, gravel, and water. By addition of pozzolan in concrete, the requirement of cement will be reduced. In the current review, major emphasis is given to eco-friendly construction material.
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Waghmode, Meghmala S., Aparna B. Gunjal, Namdeo N. Bhujbal, Neha N. Patil e Neelu N. Nawani. "Eco-Friendly Construction". In Research Anthology on Environmental and Societal Well-Being Considerations in Buildings and Architecture, 439–48. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-9032-4.ch020.

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Abstract (sommario):
Increase in urbanization leads to more construction of houses, dams, and streets. Reduction of the global warming effects can be carried out by recycling of construction material and searching for eco-friendly construction material. Greenhouse gas emissions can be reduced with the help of construction material which requires less energy for their production. The concept of eco-friendly construction is based on biomimetic (i.e., finding natural material with potential of endurance and self-cleaning properties). Construction materials like Portland cement and concrete can be replaced by eco-friendly biocement and bioconcrete. Production of biocement and bioconcrete can be done by using plants, algae, and bacteria. Use of less cement in concrete leads to less pollution. Concrete is the mixture of cement, sand, gravel, and water. By addition of pozzolan in concrete, the requirement of cement will be reduced. In the current review, major emphasis is given to eco-friendly construction material.
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Atti di convegni sul tema "Biocement"

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Chu, Jian, Volodymyr Ivanov, Ming Fen Lee, Xiao-Ming Oh e Jia He. "Soil and Waste Treatment Using Biocement". In International Symposium on Ground Improvement Technologies and Case Histories. Singapore: Research Publishing Services, 2009. http://dx.doi.org/10.3850/gi195.

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Naeimi, Maryam, Jian Chu, Volodymyr Ivanov e Victor Stabnikov. "Improvement of Engineering Properties of Granular Soil using Biocement". In International Conference on Ground Improvement & Ground Control. Singapore: Research Publishing Services, 2012. http://dx.doi.org/10.3850/978-981-07-3560-9_05-0502.

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Ramachandran, Asha, Navdeep Kaur Dhami e Abhijit Mukherjee. "Sustainable utilization of biopolymers and biocement in aggregation of granular materials". In Fifth International Conference on Sustainable Construction Materials and Technologies. Coventry University and The University of Wisconsin Milwaukee Centre for By-products Utilization, 2019. http://dx.doi.org/10.18552/2019/idscmt5064.

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Dubey, Anant Aishwarya, Rituraj Devrani, K. K Dhami e Abhijit Mukherjee. "Influence of Single-Dose Biocement Treatment on the Hydraulic Conductivity of the Riverbank Sand". In The 7th World Congress on Civil, Structural, and Environmental Engineering. Avestia Publishing, 2022. http://dx.doi.org/10.11159/icgre22.201.

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Noshi, C. I., e J. J. Schubert. "Self-Healing Biocement and Its Potential Applications in Cementing and Sand-Consolidation Jobs: A Review Targeted at the Oil and Gas Industry". In SPE Liquids-Rich Basins Conference - North America. Society of Petroleum Engineers, 2018. http://dx.doi.org/10.2118/191778-ms.

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Adhikari, Udhab, Nava P. Rijal, Shalil Khanal, Devdas Pai, Jagannathan Sankar e Narayan Bhattarai. "Magnesium and Calcium-Containing Scaffolds for Bone Tissue Regeneration". In ASME 2016 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/imece2016-66835.

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Bone is a living tissue that constantly remodels and adapts to the stresses imposed upon it. Bone disorders are of growing concern as the median age of our population rises. Healing and recovery from fractures requires bone cells to have a 3-dimensional (3D) structural base, or scaffold, to grow out from. In addition to providing mechanical support, the scaffold, an extracellular matrix (ECM) assembly, enables the transport of nutrients and oxygen in and removal of waste materials from cells that are growing into new tissue. In this research, a 3D scaffold was synthesized with chitosan (CS), carboxymethyl chitosan (CMC), calcium phosphate monobasic and magnesium oxide (MgO). CS is a positiviely-charged natural bioactive polymer. It is combined with its negatively-charged derivative, CMC, to form a complex scaffold. Magnesium phosphate biocement (MgP), formed by reacting calcium phosphate monobasic and MgO, was incorporated into CMC solution before adding CS solution. Scaffolds were prepared by casting, freezing and lyophilization. The scaffolds were characterized in terms of pore microstructures, surface topography, water uptake and retention abilities, and crystal structure. The results show that the developed scaffolds exhibit highly interconnected pores and present the ideal pore size range (100–300 μm) to be morphometrically suitable for the proposed bone tissue engineering applications. These scaffolds not only mimic the nanostructured architecture and the chemical composition of natural bone tissue matrices but also serve as a source for soluble ions of magnesium (Mg++) and calcium (Ca++) that are favorable to osteoblast cells. The scaffolds thus provide a desirable microenvironment to facilitate biomineralization. These observations provide a new effective approach for preparing scaffold materials suitable for bone tissue engineering.
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Donovan Mujah, Mohamed Shahin e Liang Cheng. "Performance of biocemented sand under various environmental conditions". In VII Simpósio Brasileiro de Engenheiros Geotécnicos Jovens. São Paulo, SP, Brasil: Associação Brasileira de Mecânica dos Solos e Engenharia Geotécnica - ABMS, 2016. http://dx.doi.org/10.20906/cps/gj-05-0002.

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