The present work aims to examine the drilling performance of AISI 321 stainless steel using vegetable-oil-based cutting fluid under different minimum quantity lubrication (MQL) strategies (with and ...without graphene nanoparticles). Experimental results indicated that MQL drilling with 1.5 wt% of graphene nanoparticles considerably reduced the thrust force (27.4%), torque (64.9%), surface roughness (33.8%) and coefficient of friction (51.7%) at the 30th hole as compared to pure MQL condition and also improved the tool life. In brief, the sufficient quantity of graphene nanoparticles in nanofluid MQL drilling can boost the lubrication performance and increase the stability of lubrication film, which improves the drilling characteristics.
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•Nano-graphene was mixed into vegetable-oil based cutting fluid in MQL drilling.•The performance of different lubrication strategies on the drilling characteristics was evaluated.•The sufficient amount of nano-graphene can improve cooling/lubrication performances.•This investigation can reduce environmental-impact and improve drilling efficiency.
We investigated the involvement of peroxisome proliferator activated receptor-γ (PPAR-γ)/endothelial nitric oxide synthase (eNOS) pathway in estradiol mediated protection against ischemia reperfusion ...(I/R)-induced acute kidney injury (AKI) in rats. To induce AKI, rats underwent 40 min of bilateral renal ischemia followed by 24 h of reperfusion. I/R-induced kidney damage was quantified by measuring serum creatinine, creatinine clearance, urea nitrogen, uric acid, potassium, fractional excretion of sodium, microproteinuria, and renal oxidative stress (thiobarbituric acid reactive substances, superoxide anion generation, and reduced glutathione). Hematoxylin eosin stain demonstrated renal histology, while renal expression of apoptotic markers (Bcl-2, Bax), PPAR-γ and eNOS were quantified by immunohistochemistry. Estradiol (1 mg/kg, i.p.) was administered 30 min before I/R in rats. In separate groups, PPAR-γ antagonist, BADGE (30 mg/kg, i.p.), and NOS inhibitor,
l
-NAME (20 mg/kg, i.p.) were administered prior to estradiol treatment, which was followed by I/R in rats. I/R caused significant renal damage as demonstrated by biochemical (serum/urine), renal oxidative stress and histological changes alongwith increased expression of Bax and decreased levels of Bcl-2, PPAR-γ and eNOS, which were prevented by estradiol. Pre-treatment with BADGE and
l
-NAME abolished estradiol mediated renoprotection. Notably, I/R + estradiol + BADGE group revealed decreased expression of PPAR-γ and eNOS in renal tissues. In I/R + estradiol +
l
-NAME group, eNOS expression was reduced while PPAR-γ levels remained unchanged. These results suggest that estradiol modulates PPAR-γ which consequently regulates eNOS expression in rat kidneys. We conclude that estradiol protects against I/R-induced AKI through PPAR-γ stimulated eNOS activation in rats.
Lung cancer is one of the most common causes of death among all cancer-related diseases (Cancer Research UK in Cancer mortality for common cancers.
...http://www.cancerresearchuk.org/health-professional/cancer-statistics/mortality/common-cancers-compared
,
2017
). It is primarily diagnosed by performing a scan analysis of the patient’s lung. This scan analysis could be of X-ray, CT scan, or MRI. Automated classification of lung cancer is one of the difficult tasks, attributing to the varying mechanisms used for imaging patient’s lungs. Image processing and machine learning approaches have shown a great potential for detection and classification of lung cancer. In this paper, we have demonstrated effective approach for detection and classification of lung cancer-related CT scan images into benign and malignant category. Proposed approach firstly processes these images using image processing techniques, and then further supervised learning algorithms are used for their classification. Here, we have extracted texture features along with statistical features and supplied various extracted features to classifiers. We have used seven different classifiers known as
k
-nearest neighbors classifier, support vector machine classifier, decision tree classifier, multinomial naive Bayes classifier, stochastic gradient descent classifier, random forest classifier, and multi-layer perceptron (MLP) classifier. We have used dataset of 15750 clinical images consisting of both 6910 benign and 8840 malignant lung cancer related images to train and test these classifiers. In the obtained results, it is found that accuracy of MLP classifier is higher with value of 88.55% in comparison with the other classifiers.
Although a lot has been done to enhance the machining performance of high strength materials, machining of these materials in an eco-friendly manner is still a challenge. Presently, researchers are ...actively working on MQL base cutting fluids to boost the heat transfer efficiency and lubricating capabilities of the cutting fluids with the application of nanoparticles. Therefore, the present study is focused on the exploration of cooling and lubrication capabilities of different vegetable oil-mixed nanofluids using different nanoparticles (i.e. Al
2
O
3
, MoS
2
, SiO
2,
CuO and graphene) in drilling under MQL technique. The main aim of the current research work is to compare the drilling performance of different cooling environments, viz. dry, flood, pure MQL (PMQL) and nanofluid MQL (NFMQL) with regard to drilling characteristics concerning the thrust force, torque, surface roughness, drill tip temperature and wear mechanism in drilling of AISI 321 stainless steel. The results obtained from the experiments confirm that NFMQL strategies have shown magnificent machining performance by improving machining characteristics. Among the nanofluids, 1.5 wt.% Al
2
O
3
NFMQL cooling strategy delivered a superior cooling–lubricating effect and enhanced the machining characteristics followed by MoS
2
, SiO
2,
CuO and graphene NFMQL conditions. 1.5 wt.% Al
2
O
3
NFMQL drilling had a thrust force, torque, surface roughness and drill tip temperature of 1035 N, 10.8 Nm, 2.902 µm and 56.5 °C, which reduced by 42.81, 64.7, 53.84 and 20.97%, respectively, than that obtained under flood drilling at 30th hole. Moreover, 1.5 wt.% Al
2
O
3
NFMQL condition successfully drilled 30 holes with minimum wear of drill tool as compared to all other drilling conditions under study. The superior performance of Al
2
O
3
NFMQL may be attributed to the fact that Al
2
O
3
nanoparticles with soybean oil performed various tribological enhancement mechanism, i.e. self-repairing or mending mechanism, rolling or ball-bearing mechanism, polishing mechanism and tribo-film formation between the contacting surfaces, which enhance the drilling characteristics.
Imidazolium sulfonate zwitterions (ZIs) with unconventional counter-anions were used to fabricate a series of mesoporous silica-gel-immobilized Brønsted acid ionic liquid (SG@BAIL) nanocatalysts. In ...comparison to traditional heterogeneous catalysts, these immobilised heterogeneous catalysts have the advantage of ionic-liquid acidic sites and the advantage of solid silica gel as a support, increasing their catalytic activities. The catalysts were analysed using a series of physicochemical techniques and their catalytic efficiencies were evaluated during the acetalization of glycerol (G) with benzaldehyde (B). The influence of the counter-anions present in the SG@BAIL catalysts was initially investigated in terms of the percentage conversion
vs.
the reaction time at a particular temperature. Furthermore, different parametric studies relating to the acetalization reaction were carried out based on the catalyst with the maximum activity. SG-C
3
ImC
3
SO
3
HOTf was observed to have the highest catalytic performance and durability during ecofriendly acetal synthesis, with the highest selectivity for 1,3-dioxane. Parametric studies of the acetalization reaction were carried out, and the catalyst showed noteworthy performance at 90 °C, showing 94% conversion in an equimolar reactant mixture under solvent-free conditions with 0.03 wt% catalyst loading in a short time span of 75 min. In addition, kinetics modelling was performed using reversible second-order kinetics to calculate the forward rate constants at various temperatures. The activation energy of the reaction was determined using the Arrhenius equation, and the overall activation energy was 69.33 kJ mol
−1
. These investigations have demonstrated the excellent potential of SG@BAIL catalysts for practical application in the glycerol acetalization process.
Imidazolium sulfonate zwitterions (ZIs) with unconventional counter-anions were used to fabricate a series of mesoporous silica-gel-immobilized Brønsted acid ionic liquid (SG@BAIL) nanocatalysts.
Wake dynamics and forced convective heat transfer characteristics past a semi-circular cylinder at incidence have been investigated numerically. Utilizing air as an operating fluid computations are ...carried out for wide ranges of the Reynolds number (80⩽Re⩽180) and angle of incidences (0⩽α⩽180°). Angle of incidence reveals three flow separation zones. Structure properties of shear layer and vortex motions on each flow separation zones are analyzed critically. Functional dependence of drag (CD), lift (CL), and moment (CM) coefficients on the angle of incidence is explored and analyzed in detail. Increase in angle of incidence increases streamline curvature. A structural similarity is observed between the contours of vorticity and the corresponding isotherms. Strouhal number shows a decreasing trend up to certain values of α and thereafter it increases marginally. A new correlation of Strouhal number as a function of Re and α has been established for the present range of Reynolds numbers. At the singularity points a sudden jump in local Nusselt number distribution is observed. The trend of variation of average Nusselt number with α is similar to that of Strouhal number variation. The average Nusselt number is found to vary as Re0.529(1+α)-0.0476.
The implementation of sustainable manufacturing techniques to make machining operations more eco-friendly is a demanding issue that has gained attention from academic and industrial sectors. In some ...machining operations, a large quantity of machining fluids is wasted to make machining easier, especially during the machining of difficult-to-machine materials such as stainless steel. In such circumstances, many researchers are investigating eco-friendly techniques. Therefore, in this study, effects of minimum quantity lubrication (MQL) with MoS
2
-enhanced vegetable-oil-based cutting fluid on the drilling characteristics of AISI 321 stainless steel are investigated. The main aim of this study is to analyse the machining performance of various coolant–lubricant strategies, namely dry, flood, pure MQL, and three nanofluid MQL (NFMQL) with regard to thrust force and torque, surface roughness, friction coefficient, chip morphology and tool wear mechanism in drilling of stainless steel (AISI 321). Research findings indicated that NFMQL drilling conditions have given excellent drilling performance by improving drilling characteristics than pure MQL, dry and flood drilling. Among the NFMQL drilling conditions, 1.5 wt.% nano-MoS
2
in sunflower oil-based MQL condition provided better cooling–lubrication effect and improved the drilling characteristics followed by 1.0 wt.% and 0.5 wt.% nano-MoS
2
in sunflower oil-based MQL conditions. The 1.5 wt.% nano-MoS
2
in sunflower oil-based MQL drilling had resulted in 43.2%, 68.9%, 56.8% and 41.6% reduced values of thrust force, torque, surface roughness and COF, respectively, at the 30th hole in comparison with flood drilling. Moreover, noticeable improvement in the chip morphology and tool wear rate has been achieved while drilling under NFMQL environments. The better drilling performance of nanofluid MQL may be attributed to the fact that nanoparticles (MoS
2
) in sunflower oil offer excellent cooling–lubrication features and provide strength to the oil film at the tool–workpiece interface. In addition, nano-MoS
2
particles have high surface activity and are easily adsorbed onto the contacting surfaces, thereby maintaining the lubrication effect.
Palladium nanoscale particles possessing distinct planes/facets for fuel cell applications are challenging to construct using simple methods. This work exhibits a facile-solution phase ...room-temperature synthesis of highly branched and exceptionally ordered 3D Pd nano-fractals (200–300 nm). Using high-resolution atomic imaging, we explain the mechanism of growth and proliferation of facets after twinning. Due to its unique and novel shape, there is an unprecedented 2.025 eV blue shift in d-region of XPS spectra of Pd nano-fractals indicating a phenomenal increase in surface electron density. This is highly favorable for utilizing this promising catalyst for enhanced surface activity. The Pd nano-fractal structures are tested as anodic material, and they show significantly enhanced electrocatalytic activity and superior long-term stability towards methanol oxidation reaction in alkaline media. Thus, low-index enclosed Pd nanostructures could be useful catalysis materials if uniquely shaped and morphologically controlled at nanoscales.
Cassia fistula
L. (Caesalpinioideae) is a highly admirable medicinal plant and is traditionally recommended for the treatment of rheumatism, liver disorders, jaundice, and other inflammatory ...diseases. This study was designed to investigate the hepatoprotective properties of ethyl acetate fraction from
C. fistula
leaves in an animal model. Treatment with thioacetamide significantly elevated the level of serum glutamic-oxaloacetic transaminase (1.75-fold), alkaline phosphatase (4.07-fold), and total bilirubin (2.29-fold) as compared to the control. It was found that pretreatment of fraction followed by consecutive 2 days thioacetamide reduced the conversion of thioacetamide carcinogen to its reactive metabolites by phase I enzymes and increased the level of detoxification phase II along with antioxidative enzymes. The histopathological studies revealed the hepatoprotective nature of the fraction in restoring the normal architecture of thioacetamide-intoxicated damaged liver. The fraction showed downregulation in the expression level of p-PI3K, p-Akt, and p-mTOR pointing towards its chemopreventive potential. The HPLC analysis of the fraction had shown the dominance of three phenolic compounds namely, catechin, epicatechin, and chlorogenic acid. The above studies comprising histopathological, immunohistochemical, and hepatic enzymes are strong indicative of the potential protective ability of ethyl acetate fraction phytoconstituents against thioacetamide-induced toxicity.
Graphical abstract
This study reports the development of a novel ternary self-assembled γ-Fe2O3/N,Fe–TiO2@GO nanocomposite as a visible to near IR (NIR) active photocatalyst prepared by ultrasonic activation followed ...by hydrothermal treatment. Band gap engineering of γ-Fe2O3/N,Fe–TiO2 was performed by varying graphene oxide (GO) content, and the band gap of γ-Fe2O3/N,Fe–TiO2@1.5%GO was narrowed to 1.5 eV due to large interfacial contact of graphene oxide and TiO2 leading to Ti–O–C bond formation causing a red shift due to the upward shift of the valance band edge. The formation of an additional band gap due to the Ti–O–C bond was also confirmed by FTIR and XPS analysis. The low-cost bioinspired GO was derived from the rice husk, which further provides efficient enhanced charge transportation and also reduces the recombination rate. The ultrafast degradation of the mixed disperse dyes (Navy Blue 3G, Scarlet RR, Scarlet 3R) with nine times enhanced photoactivity, as compared to those previously reported, was achieved with γ-Fe2O3/N,Fe–TiO2@1.5%GO. The combined effect of operational parameters was assessed by studying the effect of various parameters on the photodegradation and obtained results indicated 100% decoloration and 85% COD reduction under sunlight. The mineralization studies and transient intermediates formed from the residue collected at the interval of thirty minutes each were analyzed through LC–MS and the obtained results demonstrated the successful mineralization of mixed disperse dyes within two hours. Also, the synthesized γ-Fe2O3/N,Fe–TiO2@GO showed excellent recycling performance of up to eight cycles. This work highlights the potential of visible to NIR-responsive magnetically separable graphene-based titania as a broad spectrum photoactive material and the development of cost-effective technology for wastewater remediation under broad spectrum sunlight.
