974 research outputs found
On a group of the Form 210:(U5(2):2)
No full textThe full automorphism group U5(2):2 of the special unitary group U5(2) has a 10-dimensional absolutely irreducible module over GF(2): Hence a split extension of the form G = 210:(U5(2):2) does exist. In this paper we first determine the conjugacy classes of G using the coset analysis technique. The structures of the inertia factor groups were determined. These are the groups U5(2):2; 21+6:((31+2:8):2) and O5(2):2. We then determine the Fischer matrices and apply the Clifford-Fischer theory to com-pute the ordinary character table of G: The Fischer matrices Fi of G are all Z-valued, with sizes range between 1 and 5. The full character table of G; which is 109 x 109 C-valued matrix is available in the PhD Thesis [1] of the rst author, which could be accessed online
Correction to: Polymer Nanocomposites in Biomedical Engineering
No full textIn the original version of the book, the following belated corrections have been incorporated: The co-editor names ''Basheer Ahmed'' has been changed to ''M. Basheer Ahamed'' and ''Al-Maadeed Mariam Ali S A'' has been changed to ''Mariam Ali S A Al-Maadeed''.
In chapter ''Silver Nanoparticles and Its Polymer Nanocomposites Synthesis, Optimization, Biomedical Usage, and Its Various Applications'', the author name ''Snehal Kargirwar Bramhe'' has been changed to ''Snehal Kargirwar Brahme'' and the affiliations of authors ''Snehal Kargirwar Brahme'' and ''Subhash Kondawar'' were swapped. The correction book has been updated with the changes.Scopu
SOLVENT EFFECTS ON IR MODES OF (R)-3-METHYLCYCLOPENTANONE CONFORMERS: A COMPUTATIONAL INVESTIGATION
No full textAuthor Institution: Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 Saudi ArabiaDensity Functional Theory (DFT) calculations of infrared spectra for the optimized geometries of R-(+)-3-methylcyclopentanone (R3MCP) equatorial-methyl and axial-methyl conformers were performed in 11 common solvents of wide polarity range, in the framework of polarizable continuum model (PCM). DFT correlation function type B3LYP using a powerful basis set (aug-cc-pVDZ) yielded different linear correlation between solvent polarity and R3MCP equatorial and axial conformers IR modes frequencies, intensities, and enthalpies (W. Al-Basheer, J. Sol. Chem. 41, 1495-1506 (2012)). DFT calculations of the R3MCP equatorial and axial conformer dipole moment components in 3D were also carried out and found to have a linear correlation with solvent polarity (W. Al-Basheer et al, J. Phys. Chem. A 111(12), 2293-2298 (2007)). An observed trend for a Hypsochromic (blue) shift in the equatorial conformer IR frequencies, in comparison to Bathochromic (red) shift for the axial-methyl conformer IR modes as a function of solvent polarity increase
Smoking a dangerous addiction: A systematic review on an underrated risk factor for oral diseases
No full textDespite growing knowledge of the adverse effects of cigarette smoking on general health, smoking is one of the most widely prevalent addictions around the world. Globally, about 1.1 billion smokers and over 8 million people die each year because of cigarette smoking. Smoking acts as a source for a variety of oral and systemic diseases. Various periodontal issues such as increased pocket depth, loss of alveolar bone, tooth mobility, oral lesions, ulcerations, halitosis, and stained teeth are more common among smokers. This systematic review was conducted according to the guidelines from PRISMA, and research articles were retrieved from the Web database sources on 31 May 2021. The quality of research articles was ensured by the type of evidence from combined schema incorporating as schema-13 evidence type description, Cochrane health promotion and public health field (CHPPHF), and the health gains notation framework-14 screening question for quality assessment of qualitative and quantitative studies. Smokers have been found to have bleeding on probing, periodontal pockets, and clinical attachment loss compared to nonsmokers. Oral and respiratory cancers are among the most lethal known diseases caused by cigarette smoking and other commonly occurring sequelae such as stained teeth, periodontal diseases, etc
Monitoring the development of microcracks in reinforced concrete caused by sustained loading and chloride induced corrosion
No full textChloride-induced corrosion of steel in reinforced concrete structures is one of the main problems affecting their durability and it has been studied for decades, but most of them have focused on concrete without cracking or not subjected to any structural load. In fact, concrete structures are subjected to various types of loads, which lead to cracking when the tensile stress in concrete exceeds its tensile strength. Cracking could increase transport properties of concrete and accelerate the ingress of harmful substances (Cl -, O2, H2 O, CO2). This could initiate and accelerate different types of deterioration processes in concrete, including corrosion of steel reinforcement. The expansive products generated by the deterioration processes themselves can initiate cracking. The success of concrete patch repairs can also influence microcracking at the interface as well as the patch repair itself. Therefore, monitoring the development of microcracking in reinforced concrete members is extremely useful to assess the defects and deterioration in concrete structures. In this paper, concrete beams made using 4 different mixes were subjected to three levels of sustained lateral loading (0%, 50% and 100% of the load that can induce a crack with width of 0.1mmon the tension surface of beams - F 0.1) and weekly cycles of wetting (1 day)/drying (6 days) with chloride solution. The development of microcracking on the surface of concrete was monitored using the Autoclam Permeability System at every two weeks for 60 weeks. The ultrasonic pulse velocity of the concrete was also measured along the beam by using the indirect method during the test period. The results indicated that the Autoclam Permeability System was able to detect the development of microcracks caused by both sustained loading and chloride induced corrosion of steel in concrete. However, this was not the case with the ultrasonic method used in the work (indirect method applied along the beam); it was sensitive to microcracking caused by sustained loading but not due to corrosion.</p
Herbal Medications in Endodontics and Its Application—A Review of Literature
No full textHerbal products are gaining popularity in dental and medical practice nowadays due to their biocompatibility, higher antimicrobial activity, antioxidant and anti-inflammatory properties. Herbal medicine has experienced rapid growth in recent years due to its beneficial properties, ease of availability, and lack of side effects. As pathogenic bacteria become more resistant to antibiotics and chemotherapeutic agents, researchers are becoming more interested in alternative products and treatment choices for oral diseases. As a result, natural phytochemicals separated from plants and utilized in traditional medicine are suitable substitutes for synthetic chemicals. The aim of this review article is to list and understand several herbal alternatives that are currently accessible for use as efficient endodontic medicaments. The herbal products used in endodontics have several advantages, including safety, ease of use, increased storability, low cost, and a lack of microbial tolerance. However, preclinical and clinical testing and interactions with other materials and adverse effects are required for these herbal products
Service life and life-cycle assessment of reinforced concrete with fly ash and limestone calcined clay cement
No full textEnvironmental impact due to the emission of carbon dioxide during concrete production can be taken care by reducing the clinker content in the cement. The clinker content can be reduced by replacing it with fly ash and limestone calcined clay. Such systems can have a potential to exhibit enhanced durability/service life when exposed to chloride and carbon dioxide. However, estimating probabilistic service life of concretes with such alternative binder systems is difficult due to the lack of quantitative estimates of the input parameters such as chloride diffusion coefficient (DCl), ageing coefficient (m), carbonation coefficient (KCO2), and chloride threshold (Clth). This paper presents the experimentally observed estimates of these parameters for the following systems: (I) 100% OPC, (II) 70% OPC + 30% fly ash, and (iii) limestone calcined clay cement (LC3)-known as OPC, PFA, and LC3 concretes, respectively, herein. A total of three concrete mixes were designed. Also, based on these input parameters, the probabilistic service life estimates of a bridge pier and a girder made of these three concretes and exposed to chlorides and carbon dioxide are presented. For chloride ingress study, Fick's 2nd Law of diffusion and Clth have been used. For carbonation study, a recently developed model for estimating carbonation depth (using mixture proportion) have been used. Then, the life-cycle assessment (LCA) of these three concrete systems in terms of the CO2 emissions per unit of concrete per year of estimated service life is presented-for both chloride and carbonation induced corrosion. In chloride laden environments, the service life of the bridge pier and girder systems could be enhanced by about 10 times by using fly ash or LC3 concretes-for similar strength grade concretes. Also, the average annual CO2 emissions (during the expected service life) of PFA and LC3 concretes could be about 3 and 7 times, respectively, lower than that of OPC concretes of similar strength grade. In case of carbonation-induced corrosion, the limited experimental data indicate that the PFA and LC3 concretes could exhibit a lower service life and higher average annual CO2 emissions (during the expected service life) than OPC concretes.</p
Service life and life-cycle assessment of reinforced concrete with fly ash and limestone calcined clay cement
No full textEnvironmental impact due to the emission of carbon dioxide during concrete production can be taken care by reducing the clinker content in the cement. The clinker content can be reduced by replacing it with fly ash and limestone calcined clay. Such systems can have a potential to exhibit enhanced durability/service life when exposed to chloride and carbon dioxide. However, estimating probabilistic service life of concretes with such alternative binder systems is difficult due to the lack of quantitative estimates of the input parameters such as chloride diffusion coefficient (DCl), ageing coefficient (m), carbonation coefficient (KCO2), and chloride threshold (Clth). This paper presents the experimentally observed estimates of these parameters for the following systems: (I) 100% OPC, (II) 70% OPC + 30% fly ash, and (iii) limestone calcined clay cement (LC3)-known as OPC, PFA, and LC3 concretes, respectively, herein. A total of three concrete mixes were designed. Also, based on these input parameters, the probabilistic service life estimates of a bridge pier and a girder made of these three concretes and exposed to chlorides and carbon dioxide are presented. For chloride ingress study, Fick's 2nd Law of diffusion and Clth have been used. For carbonation study, a recently developed model for estimating carbonation depth (using mixture proportion) have been used. Then, the life-cycle assessment (LCA) of these three concrete systems in terms of the CO2 emissions per unit of concrete per year of estimated service life is presented-for both chloride and carbonation induced corrosion. In chloride laden environments, the service life of the bridge pier and girder systems could be enhanced by about 10 times by using fly ash or LC3 concretes-for similar strength grade concretes. Also, the average annual CO2 emissions (during the expected service life) of PFA and LC3 concretes could be about 3 and 7 times, respectively, lower than that of OPC concretes of similar strength grade. In case of carbonation-induced corrosion, the limited experimental data indicate that the PFA and LC3 concretes could exhibit a lower service life and higher average annual CO2 emissions (during the expected service life) than OPC concretes.</p
An in vitro stereomicroscopic evaluation of bioactivity between neo mta plus, pro root mta, biodentine & glass ionomer cement using dye penetration method
No full textThe ideal root end filling material should form a tight seal in the root canal by adhering to the cavity walls. Several materials have been used for root end filling. The present study aims to find out and compare the bioactivity of Neo MTA Plus, Pro Root MTA White, BIODENTINE & glass ionomer cement as root end filling materials using 1% methylene blue as tracer. Materials and methods: 80 extracted human permanent maxillary anterior teeth were used in the study. They were divided into four groups. Specimens were sectioned transversely in the cervical area to separate the crown from the root. The root canal was obturated with gutta percha and zinc oxide eugenol sealers. Thereafter, each sample was resected apically by removing 3 mm of the apex and filled with different materials. Samples were kept in buffering solution at 37◦C until the recommended evaluation periods. The specimens were then suspended in 1% methylene blue for 24 h, prior to the analysis. The teeth were then sectioned, and dye penetration was examined, photographed, and evaluated under a stereomicroscope. Results: Vertical dye penetration showed significant differences across different groups. The minimum dye penetration was seen in Neo MTA plus followed by BIODENTINE, Pro Root MTA and maximum in GIC. There was no significant difference in dye penetration between Neo MTA plus and BIODENTINE both at fifteen days and one-month intervals. Conclusion: The present study suggests Neo MTA plus and BIODENTINE should be the preferred material for root end filling
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