This study presents an algorithm for detection, classification, and location of transmission line faults. A fault index based on features extracted from current signals using the alienation ...coefficient and Wigner distribution function has been proposed for the detection and classification of faults. Double line and double line to ground faults have been classified from each other using ground fault index based on negative sequence current. Statistical relations are proposed for the estimation of fault location using peak values of the proposed fault index. The results of different case studies established the effectiveness of the algorithm. The algorithm is found to be effective for providing protection to transmission line against various faults. This is achieved using current signals recorded on one terminal of the line. This makes the protection scheme less complex, fast and more economic due to the elimination of the requirement of communication channel and global positioning system synchronisation. The proposed protection scheme is also validated on a real-time network of transmission utility. The effectiveness of the algorithm is established by comparing performance with reported algorithms.
This paper analyses the temporal characteristics of pan evaporation (
E
pan) trends by using Mann–Kendall non parametric test and a parametric test under the humid conditions for eleven sites of ...northeast India. Decreasing
E
pan trends have been observed mainly in pre monsoon and monsoon seasons. On examining total rainfall's relationship with
E
pan, it is observed that almost all sites do not show a concurrent decrease in
E
pan and an increase in rainfall. Trend analysis of other meteorological parameters indicates decreases in sunshine duration and wind speed in different seasons over most of the sites and an increase in relative humidity over four sites in winter and pre monsoon seasons. The likely causative meteorological parameters of
E
pan changes by stepwise regression are also identified. The findings of this study suggest that mainly two parameters i.e. sunshine duration followed by wind speed strongly influenced
E
pan changes at various sites from different regions in different seasons.
As renewable energy (RE) penetration has a continuously increasing trend, the protection of RE integrated power systems is a critical issue. Recently, power networks developed for grid integration of ...solar energy (SE) have been designed with the help of multi-tapped lines to integrate small- and medium-sized SE plants and simultaneously supplying power to the loads. These tapped lines create protection challenges. This paper introduces an algorithm for the recognition of faults in the grid to which a solar photovoltaic (PV) system is integrated. A fault index (FI) was introduced to identify faults. This FI was calculated by multiplying the Wigner distribution (WD) index and Alienation (ALN) index. The WD-index was based on the energy density of the current signal evaluated using Wigner distribution function. The ALN-index was evaluated using sample-based alienation coefficients of the current signal. The performance of the algorithm was validated for various scenarios with different fault types at various locations, different fault incident angles, fault impedances, sampling frequencies, hybrid line consisting of overhead (OH) line and underground (UG) cable sections, different types of transformer windings and the presence of noise. Two phase faults with and without the involvement of ground were differentiated using the ground fault index based on the zero sequence current. This study was performed on the IEEE-13 nodes test network to which a solar PV plant with a capacity of 1 MW was integrated. The performance of the algorithm was also tested on the western part of utility grid in the Rajasthan State in India where solar PV energy integration is high. The performance of the algorithm was effectively established by comparing it with the discrete Wavelet transform (DWT), Wavelet packet transform (WPT) and Stockwell transform-based methods.
This work presents a comparison of physicochemical and in vitro active wound healing properties of two distinct Graphene Oxides (GOs) from graphite and coal. These GOs are incorporated in Bacterial ...Nanocellulose (BNC) to form hydrogels. The performance and limitations of the loading fraction of both GOs in BNC are controlled by the processing technology and the source materials from which GOs are derived. Edge functionalization with C-GO offers the advantage of facilitating face-to-edge assembly in the hydrogel leading to better dispersion than the face-to-face assembly of basal functionalized G-GO. The latter leads to more aggregation of G-GO, resulting in a lower optimal loading fraction. Our investigation into the antibacterial properties of the BNC and BNC/GO hydrogels against gram-negative E. coli revealed inhibitory effects of the BNC/GO hydrogels that intensified with an increase in the concentration of GO. Furthermore, an in vitro wound scratch assay demonstrated that BNC/C-GO hydrogels promote better cell migration, confirming their superior biocompatibility and suitability as active wound dressings, albeit limited by loading fraction due to agglomeration. These findings shed light on the performance and limitations of GOs for diverse applications, emphasizing the significance of exploring the influence of different methods and source materials of GOs.
•G-GO suspension exhibits a larger mean size of crystallites with higher lateral size than C-GO.•G-GO has many basal functional groups and assembles face-to-face with BNC.•C-GO has mainly edge functional groups and assembles face-to-edge with BNC.•Hence, -OH groups of C-GO bind with the cytoplasmic membrane and inhibit bacterial enzymes, enhancing antibacterial activity.
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•We developed Surface altered NaNbO3 platelets-N doped graphene composite.•The composite exhibited remarkable bi-functional catalytic activities for OER/ORR.•Surface anisotropy, ...oxygen vacancies & high crystallinity is achieved in NaNbO3.•Desired characteristics are tuned by simply altering the annealing temperature.
In this work, we establish that surface reconstruction, oxygen vacancies —specifically those located on the catalyst surface, and high crystallinity can be effective in tuning the catalytic activity of perovskite oxides. We report a high-performance electrocatalyst with an orthorhombic perovskite structure (NaNbO3), having an anisotropic surface layer and high crystallinity that exhibits superior activity and durability for the bi-functional oxygen electrochemistry compared to that of a similar perovskite composition with an isotropic surface layer and low crystallinity. The improvement in the electrocatalytic activity for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is mainly attributed to the formation of an easy diffusion path on the surface layer due to the ionic movements, enhanced intrinsic activity of the catalytic sites resulting from the higher crystallinity, high oxygen vacancies and a large electrochemically active surface area. The sole key parameter in achieving all the acquired characteristics is the annealing temperature. We believe that the straightforward method of bringing the desired combination of properties by just tweaking the annealing temperature is handy and energy-efficient, and hence easily adoptable.
Spatiotemporal variation of temperature and precipitation helps in classification of type of climate of each region and affects the availability of access of drinking water to the inhabitants in the ...region. A new index that is called as the temperature concentration index (TCI) was developed in the present study to investigate the concentration of temperature in Iran based on the two known inspiring patterns of Gibbs–Martin (Am Sociol Rev 27:667–677,
1962
) and Oliver (Prof Geogr 32:300–309,
1980
). The developed index was classified based on three methods, including the Oliver’ classification (
1980
), the coefficient of variation of temperature data, and coefficient of variation of TCI values. The results show that all the three classification methods represent almost similar classes for the TCI. After the classification of the proposed TCI, two indices of the precipitation concentration index (PCI) and the TCI were applied to the long-term analysis of precipitation and temperature of thirty-four synoptic stations of Iran during the 50-year period (1961–2010). Based on the TCI, highly irregular distributions in temperature were observed during the winter season in the northwest of Iran. In the annual timescale, the calculated TCI values indicated the uniform temperature pattern in the borders of the Persian Gulf, the Gulf of Oman, and the coast of the Caspian Sea. The comparison between the two indices, the PCI and the TCI, reveal that these two indices are inversely related to each other; i.e., reduction in one index will be along with an increase in another index. The irregular distribution of temperature implies higher changes in temperature, and so the conditions for higher precipitation will be provided. The PCI index represents a uniform distribution of the precipitation over the selected stations of Iran.
Biofilm in endodontics: A review Jhajharia, Kapil; Parolia, Abhishek; Shetty, K ...
Journal of International Society of Preventive and Community Dentistry,
01/2015, Letnik:
5, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Endodontic disease is a biofilm-mediated infection, and primary aim in the management of endodontic disease is the elimination of bacterial biofilm from the root canal system. The most common ...endodontic infection is caused by the surface-associated growth of microorganisms. It is important to apply the biofilm concept to endodontic microbiology to understand the pathogenic potential of the root canal microbiota as well as to form the basis for new approaches for disinfection. It is foremost to understand how the biofilm formed by root canal bacteria resists endodontic treatment measures. Bacterial etiology has been confirmed for common oral diseases such as caries and periodontal and endodontic infections. Bacteria causing these diseases are organized in biofilm structures, which are complex microbial communities composed of a great variety of bacteria with different ecological requirements and pathogenic potential. The biofilm community not only gives bacteria effective protection against the host's defense system but also makes them more resistant to a variety of disinfecting agents used as oral hygiene products or in the treatment of infections. Successful treatment of these diseases depends on biofilm removal as well as effective killing of biofilm bacteria. So, the fundamental to maintain oral health and prevent dental caries, gingivitis, and periodontitis is to control the oral biofilms. From these aspects, the formation of biofilms carries particular clinical significance because not only host defense mechanisms but also therapeutic efforts including chemical and mechanical antimicrobial treatment measures have the most difficult task of dealing with organisms that are gathered in a biofilm. The aim of this article was to review the mechanisms of biofilms' formation, their roles in pulpal and periapical pathosis, the different types of biofilms, the factors influencing biofilm formation, the mechanisms of their antimicrobial resistance, techniques to identify biofilms.
Celiac disease (CD) has been linked to portal hypertension (PHT) of varied etiology, but the causality association has never been proved. We aim to study the prevalence of CD in patients of PHT of ...different etiology.
A prospective observational study was conducted from June 2017 to December 2018 involving all the cases of PHT of varied etiology. Consecutive patients of PHT with chronic liver disease (CLD) of defined etiology like ethanol, viral hepatitis (B or C), Budd–Chiari syndrome (BCS), autoimmune-related cirrhosis, and cryptogenic CLD (cCLD) (group A) and those with noncirrhotic PHT (NCPHT), which included noncirrhotic portal fibrosis (NCPF) and extrahepatic portal vein obstruction (EHPVO) (group B), were screened for CD by IgA anti-tTG antibody followed by duodenal biopsy in serology-positive patients.
Out of a total of 464 patients, group A constituted 382 patients, CLD related to ethanol (155), cCLD (147), hepatitis B (42), hepatitis C (21), autoimmune (10), and BCS (7), whereas 82 patients were in group B with NCPF (64) and EHPVO (18). Total 29 patients were diagnosed with CD in both groups, 17 in group A (4.5%) and 12 in group B (14.6%). In group A, 13 patients with cCLD, two with HBV-related CLD, one with BCS, and one with autoimmune-related CLD were concomitantly diagnosed as CD. In group B, CD was diagnosed in 12 patients of NCPF (11) and EHPVO (1). Liver histology showed chronic hepatitis in two patients and was normal in three patients.
CD is common in PHT of different etiology, especially in cCLD, NCPH and autoimmune hepatitis; however, the etiological basis for this association is still to be defined. The likelihood of CD is higher in liver disease than the general population, and these patients should be screened for CD.
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