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1.
Artículo en Inglés | MEDLINE | ID: mdl-38795293

RESUMEN

This study explores the viability of using Bambusa bambos, sourced from Madhya Pradesh, India, as a reinforcement material in continuously reinforced concrete pavement (CRCP) construction, aiming to assess its potential as a sustainable alternative to traditional steel reinforcement. The research encompasses a comprehensive evaluation of physical and mechanical properties, including tensile, compressive, and bending strengths, and a detailed microstructural analysis using scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) of Bambusa bambos. The study involved finite element analyses that modeled bamboo-reinforced concrete (BRC) beams, exploring the impact of horizontal and vertical placements of bamboo strips on flexural behavior under bending loads. The analysis aided in observing compressive and tensile stresses generated in concrete and bamboo, with specific FEA results indicating that beams with vertically aligned bamboo strips in both the compression (compressive stress of 16.90 MPa for beam B1) and tension zones (tensile stress of 7.22 MPa for beam B1) withstand flexural stresses effectively. Additionally, the multi-criteria decision-making approach using the TOPSIS method to rank different beam designs. Key findings obtained from FEA indicate that the vertical alignment of bamboo strips in both the compression and tension zones of the beams is optimally effective in handling flexural stresses.

2.
Environ Sci Pollut Res Int ; 31(7): 10346-10358, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37515619

RESUMEN

In recent years, a sudden upsurge in the quantity of municipal solid waste (MSW) has been observed, and the status quo demands a constructive and economically viable solution. The use of stabilized municipal solid waste (SMSW) in road construction can help in reducing the burden on landfills and waste management authorities. In the existing study, SMSW was accumulated from the Okhla landfill which is situated in New Delhi that is rich in an organic content. This SMSW was then blended with soil (5%, 10%, and 15%) and bottom ash with varying percentages (10%, 20%, 30%) individually and a mix of soil and bottom ash in the ratio of 1:1 to reduce the content of organic matter. The blended sample was then tested to check its compaction value, California bearing ratio (CBR), unconfined compressive strength (UCS), durability, and scanning electron microstructure (SEM). The results indicated that the addition of bottom ash to SMSW decreases the maximum dry unit weight that varies between 1.65 and 1.51 KN/m3 while this value reduces to 1.72 to 1.67 KN/m3 in the case of the bottom ash-soil blend. Also, CBR value reduces to 25.50 to 18.00% in case of bottom ash and 25.89 to 21.92% for bottom ash-soil samples and inverse in the case of SMSW samples blended with soil ranges between 19.95 and 22.59%. The California bearing ratio value of all samples under soaked condition meets the minimum criteria (> 10%) as specified in IRC SP-72 for low-volume roads, but at the same time failed to meet the durability specifications. Thus, it is recommended to use this soil subgrade material in arid regions.


Asunto(s)
Eliminación de Residuos , Administración de Residuos , Residuos Sólidos , Ceniza del Carbón , Incineración , Suelo , Eliminación de Residuos/métodos
3.
Nanoscale ; 13(33): 13923-13942, 2021 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-34477675

RESUMEN

Owing to their peculiar oxidative effect, silver cations (Ag+) are well known for their antimicrobial properties and explored as therapeutic agents for biomedical applications. Size control with improved dispersion and stability are the key factors of Ag NPs (silver nanoparticles) to be used in biomedical applications. Silver based nano-materials are highly efficient due to their biological, chemical and physical properties in comparison with bulk silver. Atomic scale fabrication is achieved by rearranging the internal components of a material, in turn, influencing the mechanical, electrical, magnetic, thermal and chemical properties. For instance, size and shape have a strong impact on the optical, thermal and catalytic properties of Ag NPs. Such properties can be tuned by controlling the surface/volume ratio of Ag nanostructures with a small size (ideally <100 nm), in turn showing peculiar biological activity different from that of bulk silver. Silver nanomaterials such as nanoparticles, thin films and nanorods can be synthesized by various physical, chemical and biological methods whose most recent implementations will be described in this review. By controlling the structure-functionality relationship, silver based nano-materials have high potential for commercialization in biomedical applications. Antimicrobial, antifungal, antiviral, and anti-inflammatory Ag NPs can be applied in several fields such as pharmaceutics, sensors, coatings, cosmetics, wound healing, bio-labelling agents, antiviral drugs, and packaging.


Asunto(s)
Antiinfecciosos , Nanopartículas del Metal , Nanoestructuras , Antibacterianos/farmacología , Antiinfecciosos/farmacología , Plata
4.
Materials (Basel) ; 13(20)2020 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-33080937

RESUMEN

Iron oxides are chemical compounds which have different polymorphic forms, including γ-Fe2O3 (maghemite), Fe3O4 (magnetite), and FeO (wustite). Among them, the most studied are γ-Fe2O3 and Fe3O4, as they possess extraordinary properties at the nanoscale (such as super paramagnetism, high specific surface area, biocompatible etc.), because at this size scale, the quantum effects affect matter behavior and optical, electrical and magnetic properties. Therefore, in the nanoscale, these materials become ideal for surface functionalization and modification in various applications such as separation techniques, magnetic sorting (cells and other biomolecules etc.), drug delivery, cancer hyperthermia, sensing etc., and also for increased surface area-to-volume ratio, which allows for excellent dispersibility in the solution form. The current methods used are partially and passively mixed reactants, and, thus, every reaction has a different proportion of all factors which causes further difficulties in reproducibility. Direct active and complete mixing and automated approaches could be solutions to this size- and shape-controlled synthesis, playing a key role in its exploitation for scientific or technological purposes. An ideal synthesis method should be able to allow reliable adjustment of parameters and control over the following: fluctuation in temperature; pH, stirring rate; particle distribution; size control; concentration; and control over nanoparticle shape and composition i.e., crystallinity, purity, and rapid screening. Iron oxide nanoparticle (IONP)-based available clinical applications are RNA/DNA extraction and detection of infectious bacteria and viruses. Such technologies are important at POC (point of care) diagnosis. IONPs can play a key role in these perspectives. Although there are various methods for synthesis of IONPs, one of the most crucial goals is to control size and properties with high reproducibility to accomplish successful applications. Using multiple characterization techniques to identify and confirm the oxide phase of iron can provide better characterization capability. It is very important to understand the in-depth IONP formation mechanism, enabling better control over parameters and overall reaction and, by extension, properties of IONPs. This work provides an in-depth overview of different properties, synthesis methods, and mechanisms of iron oxide nanoparticles (IONPs) formation, and the diverse range of their applications. Different characterization factors and strategies to confirm phase purity in the IONP synthesis field are reviewed. First, properties of IONPs and various synthesis routes with their merits and demerits are described. We also describe different synthesis strategies and formation mechanisms for IONPs such as for: wustite (FeO), hematite (α-Fe2O3), maghemite (ɤ-Fe2O3) and magnetite (Fe3O4). We also describe characterization of these nanoparticles and various applications in detail. In conclusion, we present a detailed overview on the properties, size-controlled synthesis, formation mechanisms and applications of IONPs.

5.
J Indian Prosthodont Soc ; 18(2): 122-130, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29692565

RESUMEN

AIM: An attempt is made to investigate clinical efficacy of cord, paste system, and a strip gingival retractile materials. This study aims to evaluate and compare the gingival retraction efficacy of retraction strip along with conventional retraction cord and paste system. MATERIAL AND METHODS: This in vivo experimental study was carried out on 30 patients. Three different gingival retraction systems were used to evaluate the amount of vertical and lateral displacement.Based on selection criteria, 30 individuals requiring fixed dental prosthesis with respect to mandibular first molar were selected. Tooth preparation for metal ceramic restoration with subgingival finish line was performed. Gingival displacement was accomplished with ultrapak cord, merocel strip, and magic foam cord immediately, 7 and 14 days after the tooth preparation, respectively. The amount of gingival displacement in vertical and lateral directions was measured at mesiobuccal, midbuccal, and distobuccal regions of the prepared tooth. The vertical retraction was measured intraorally by using digital vernier caliper, and postgingival displacement impression was used to measure lateral gingival retraction. Stereomicroscopic images of impression under ×10 resolution were transferred to image analyzer to measure the lateral displacement. The obtained data analyzed in one-way ANOVA and Bonferroni test were used to determine the significant difference at P < 0.05 level. RESULTS: ANOVA test showed the significant difference between the materials tested with respect to the mean vertical and lateral gingival retraction (P = 0.001). Multiple comparisons by Bonferroni test revealed a significant difference in vertical and lateral displacement among the materials tested. CONCLUSIONS: Merocel strip provided the maximum amount of vertical and lateral tissue displacement, followed by ultrapak cord and least with magic foam cord which was statistically significant.

6.
Case Rep Dent ; 2013: 537120, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23762645

RESUMEN

Oral habits in form of digit/thumb sucking are common phenomenon and part of childhood behavior. They are normally associated with oral pleasure, hunger, anxiety, and sometimes psychological disturbances. Chronic practice can cause major orthopedic alterations to the skeletal structures of the oral cavity and lower face. Aversive approaches in form of punitive therapy have been moderately effective. Modified bluegrass appliance is nonpunitive therapy to treat sucking habits. It acts as a habit reversal technique and installs positive reinforcement in children. Modified blue grass appliance proved to be very comfortable to patients and encourages neuromuscular stimulations.

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