This study focuses on the physicochemical and tribological properties of bio-lubricants and commercial lubricant blends dispersed with graphene nanoplatelets. In the processing of the bio lubricant, ...special care was taken to ensure that the physicochemical properties do not deteriorate too much when the bio lubricant is blended with commercial oil.
Calophyllum inophyllum
(Tamanu tree) seed oil was used to prepare a penta-erythritol (PE) ester. The PE ester was mixed with commercial SN motor oil at 10, 20, 30 & 40% v/v concentrations. The oil samples are tested on a four-ball wear tester to see how well they perform under wear, friction, and extreme pressure conditions. The optimum blend of PE ester - commercial SN motor oil for the best performance is found in the first phase. Later the optimum blend of commercial oil and bio-lubricant is dispersed with graphene nanoplatelets in 0.025%, 0.05%, 0.1%, 0.25%, 0.5% and 1% weight fractions. A blend ratio of 30% bio-lubricant in commercial oil dispersed with 0.05% graphene nanoplatelets dramatically reduces friction and wear. During the extreme pressure test, commercial oil, and bio-lubricant blends performed better in load-carrying capacity and welding force, indicating an improved load-wear index. These improved properties due to the dispersion of graphene nanoplatelets could facilitate the use of a higher blend percentage of bio lubricant. Analysis of the worn surfaces after the EP test showed that bio lubricant, additives, and graphene worked together in the blend of bio lubricant and commercial oil.
This study focuses on the physicochemical and tribological properties of bio-lubricants and commercial lubricant blends dispersed with graphene nanoplatelets.
Strain derivative of local anisotropy, which depends on the magnetostriction, is the figure of merit for the magnetic materials used in automobile torque sensor applications. In order to improve the ...strain derivative, a series of samples with chemical formulae CoMnxFe2−xO4 (x=0.00–0.60) was prepared by a conventional ceramic technique. X-ray diffraction patterns of the samples confirm cubic spinel crystal structures. The magnetic properties, such as saturation magnetization and coercivity, were measured and the Curie temperature was estimated. Magnetostrictive properties were studied by the tensile strain gauge method. Manganese substituted cobalt ferrites have shown improved strain derivative values as compared to the pure cobalt ferrite. The strain derivative has been observed to increase for larger Mn substituent concentrations in CoMnxFe2−xO4. This behavior has been ascribed to the net decreased anisotropic contribution due to the increased presence of Mn3+ ions in B-sites and a corresponding migration of Co2+ ions to A-sites, and also to the microstructural grain size of the samples. The coercivity and magnetostriction measurements are in support of the strain derivative variations. The results are discussed on the basis of cationic site occupancies, variations in grain size and reduced anisotropy of the system.
•Magnetic and magnetostrictive properties of CoMnxFe2−xO4 were reported.•Maximum magnetostriction was retained for smaller Mn concentrations up to x=0.3.•Strain derivative increases at larger Mn concentrations in CoMnxFe2−xO4.•The results are explained by microstructures and reduced anisotropy of the system.
The Ultra-Violet Imaging Telescope (UVIT) is one of the payloads in ASTROSAT, the first Indian Space Observatory. The UVIT instrument has two 375 mm telescopes: one for the far-ultraviolet (FUV) ...channel (1300-1800 ), and the other for the near-ultraviolet (NUV) channel (2000-3000 ) and the visible (VIS) channel (3200-5500 ). UVIT is primarily designed for simultaneous imaging in the two ultraviolet channels with spatial resolution better than 1 8, along with provisions for slit-less spectroscopy in the NUV and FUV channels. The results of in-orbit calibrations of UVIT are presented in this paper.
Soil microbial communities are important drivers of biogeochemical cycling of nutrients, organic matter decomposition, soil organic carbon, and Greenhouse gas emissions (GHGs: CO
, N
O, and CH
) and ...are influenced by crop and soil management practices. The knowledge on the impact of conservation agriculture (CA) on soil bacterial diversity, nutrient availability, and GHG emissions in semi-arid regions under rainfed conditions is vital to develop sustainable agricultural practices, but such information has not been systemically documented. Hence, studies were conducted for 10 years in rainfed pigeonpea (
L.)-castor bean (
L.) cropping system under semi-arid conditions to assess the effects of tillage and crop residue levels on the soil bacterial diversity, enzyme activity (Dehydrogenase, urease, acid phosphatase, and alkaline phosphatase), GHG emissions, and soil available nutrients (Nitrogen, phosphorus, and potassium). Sequencing of soil DNA through Illumina HiSeq-based 16S rRNA amplicon sequencing technology has revealed that bacterial community responded to both tillage and residue levels. The relative abundance of Actinobacteria in terms of Operational Taxonomic Unit (OTUs) at phyla, class as well as genera level was higher in CA (NTR1: No Tillage + 10 cm anchored residue and NTR2 NT + 30 cm anchored residue) over CT (conventional tillage without crop residues). CA resulted in higher enzyme activities (dehydrogenase, urease, acid phosphatase, and alkaline phosphatase) and reduction in GHG emissions over CT. CA recorded 34% higher and 3% lower OC, as compared to CT, and CTR1, respectively. CA recorded 10, 34, and 26% higher available nitrogen, phosphorus, and potassium over CT and CTR1, respectively. NTR1 recorded 25 and 38% lower N
O emissions as compared to CTR1 and CTR2, respectively. Whereas only NT recorded 12% higher N
O emissions as compared to CT. Overall, the results of the study indicate that CA improves the relative abundance of soil bacterial communities, nutrient availability, and enzyme activities, and may help to contribute to the mitigation of climate change, and sustainability in rainfed areas.
Microgrids are being evolved as a potential alternative to reduce unrelenting dependency on central utility grids. Moreover, integrated multi-microgrid based clusters are forming in closed vicinities ...to enhance the benefits of microgrids. However, the power quality problem is one of the key issues to be solved in such systems, which is mainly caused by the rising penetration of nonlinear loads and interfacing of power electronic converters. To address this issue, this paper proposes a new control technique, named "adaptive neuro-fuzzy control strategy". This controls the inverter of each microgrid in the cluster as well as the voltage source converter based distribution static compensator located at the point of common coupling between the cluster and the utility grid. This proposed control strategy uses the advantages of both fuzzy logic and artificial neural networks, thereby effectively controls the system. The proposed technique is modelled in MATLAB/Simulink software 2021a. For the analysis, various power quality indices such as voltage sag/swell, voltage unbalance, frequency deviations, power characteristics, total harmonic distortion, and neutral current compensation are measured. These indices of the proposed controller are compared with conventional PI and fuzzy logic-based controllers in view of various key IEEE/IEC standard tolerances. From these results, the proposed controller has proved its superiority.
Aims
The RT‐PCR is the most popular confirmatory test for SARS‐CoV‐2. It is sensitive, but high instrumentation cost makes it difficult for use outside routine clinical setup. This has necessitated ...the development of alternative methods such as CRISPR‐based DETECTR method which uses lateral flow technology. Although accurate and sensitive, this method is limited by complex steps and recurrent cost of high‐quality lateral flow strips. The main goal of this study was to improve the Cas12a‐based SARS‐CoV‐2 DETECTR method and develop a portable and field‐deployable system to reduce the recurring consumable cost.
Methods and results
Specific regions of N and E genes from SARS‐CoV‐2 virus and human RNase P (internal control) were reverse transcribed (RT) and amplified by loop‐mediated isothermal amplification (LAMP). The amplified products were detected by a Cas12a‐based trans‐cleavage reaction that generated a fluorescent signal which could be easily visualized by naked eye. Detection of internal control, RNase P gene was improved and optimized by redesigning RT‐LAMP primers. A number of steps were reduced by combining the reagents related to the detection of Cas12a trans‐cleavage reaction into a single ready‐to‐use mix. A portable, cost‐effective battery‐operated instrument, CRISPR‐CUBE was developed to run the assay and visualize the outcome. The method and instrument were validated using both contrived and patient samples.
Conclusions
The simplified CRISPR‐based SARS‐CoV‐2 detection and instrument developed in this study, along with improved design for internal control detection allows for easier, more definitive viral detection requiring only reagents, consumables and the battery operable CRISPR‐CUBE.
Significance and impact of study
Significant improvement in Cas12 method, coupled with simple visualization of end point makes the method and instrument deployable at the point‐of‐care (POC) for SARS‐CoV‐2 detection, without any recurrent cost for the lateral flow strips which is used in other POC methods.
The main purpose of this study was to comprehensively investigate the potential of fractal dimension (FD) measures in discriminating brain gliomas into low-grade glioma (LGG) and high-grade glioma ...(HGG) by examining tumor constituents and non-tumorous gray matter (GM) and white matter (WM) regions.
Retrospective magnetic resonance imaging (MRI) data of 42 glioma patients (LGG, n = 27 and HGG, n = 15) were used in this study. Using MRI, we calculated different FD measures based on the general structure, boundary, and skeleton aspects of the tumorous and non-tumorous brain GM and WM regions. Texture features, namely, angular second moment, contrast, inverse difference moment, correlation, and entropy, were also measured in the tumorous and non-tumorous regions. The efficacy of FD features was assessed by comparing them with texture features. Statistical inference and machine learning approaches were used on the aforementioned measures to distinguish LGG and HGG patients.
FD measures from tumorous and non-tumorous regions were able to distinguish LGG and HGG patients. Among the 15 different FD measures, the general structure FD values of enhanced tumor regions yielded high accuracy (93%), sensitivity (97%), specificity (98%), and area under the receiver operating characteristic curve (AUC) score (98%). Non-tumorous GM skeleton FD values also yielded good accuracy (83.3%), sensitivity (100%), specificity (60%), and AUC score (80%) in classifying the tumor grades. These measures were also found to be significantly (
< 0.05) different between LGG and HGG patients. On the other hand, among the 25 texture features, enhanced tumor region features, namely, contrast, correlation, and entropy, revealed significant differences between LGG and HGG. In machine learning, the enhanced tumor region texture features yielded high accuracy, sensitivity, specificity, and AUC score.
A comparison between texture and FD features revealed that FD analysis on different aspects of the tumorous and non-tumorous components not only distinguished LGG and HGG patients with high statistical significance and classification accuracy but also provided better insights into glioma grade classification. Therefore, FD features can serve as potential neuroimaging biomarkers for glioma.
The 3 x 2 m spacing currently used for eucalyptus plantations in the state of Andhra Pradesh, southern India does not permit intercropping from the second year. This discourages small landholders who ...need regular income from taking up eucalyptus plantations and benefiting from the expanding market for pulpwood. Therefore, on-farm experiments were conducted near Bhadrachalam, Khammam district (Andhra Pradesh) for over 4 years from August 2001 to November 2005 to examine whether wide-row planting and grouping of certain tree rows will facilitate extended intercropping without sacrificing wood yield. Eucalyptus planted in five-spatial arrangements in agroforestry 3 x 2 m (farmers' practice), 6 x 1 m, 7 x 1.5 m paired rows (7 x 1.5 PR), 11 x 1 m paired rows (11 x 1 PR) and 10 x 1.5 m triple rows (10 x 1.5 TR) was compared with sole tree stands at a constant density of 1,666 trees ha⁻¹. Cowpea (Vigna unguiculata) was intercropped during the post-rainy seasons from 2001 to 2004, and fodder grasses (Panicum maximum and Brachiaria ruziziensis) were intercropped during both the seasons of 2005. At 51 months after planting, different spatial arrangements did not significantly affect height and diameter at breast height (dbh). Total dry biomass of eucalyptus in different spatial arrangements ranged between 59.5 and 52.9 Mg ha⁻¹, the highest being with 6 x 1 m and the lowest with 10 x 1.5 TR, but treatment differences were not significant. The widely spaced paired row (11 x 1 PR) and triple row (10 x 1.5 TR) arrangements produced 62-73% of sole cowpea yield in 2003, 59-66% of sole cowpea yield in 2004, and 79-94% of sole fodder in 2005. In contrast, the 3 x 2 m spacing allowed only 17-45% of sole crop yields in these years. The better performance of intercrops in widely spaced eucalyptus was likely because of limited competition from trees for light and water. Intercropping of eucalyptus in these wider rows gave 14% greater net returns compared with intercropping in eucalyptus spaced at 3 x 2 m, 19% greater returns compared with that from sole tree woodlot and 263% greater returns compared with that from sole crops. Therefore, in regions where annual rainfall is around 1,000 mm and soils are fairly good, eucalyptus at a density of 1,666 plants per ha can be planted in uniformly spaced wide-rows (6 m) or paired rows at an inter-pair spacing of 7-11 m for improving intercrop performance without sacrificing wood production.
A clean synthesis of 1,8-dioxo-octahydroxanthenes as potential anticancer agents, structure elaboration of one compound and crystal structure analysis of another compound is presented.
Molecular ...iodine facilitated the reaction of 5,5-dimethyl-1,3-cyclohexanedione with aromatic aldehydes in iso-propanol affording a variety of 1,8-dioxo-octahydroxanthenes in high yields. Most of the compounds synthesized showed good anti-proliferative properties in vitro against three cancer cell lines and 9-(2-hydroxyphenyl)-3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione possessing a 2-hydroxy phenyl group at C-9 position was found to be promising. Further structure elaboration of the same compound and the crystal structure analysis and hydrogen bonding patterns of another compound that is, 9-(4-methoxyphenyl)-3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione prepared by using this methodology is presented.
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