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This paper summaries the wear behavior of steel vs steel for various industrial application. In today’s world, many new materials are developed and manufactured. Tribological behaviour of material is investigated in terms of wear and frictional characteristics using pin on disc machine. This paper reviews the experimental investigation of tribological behavior of different grade of steel considering various aspects such as coated/uncoated disc and pin materials, effect of magnetic field and lubricant under different operating and loading conditions at room and at high temperature. The summary of various research papers is tabulated and discussed. It observes that the common objective of wear analysis is to minimize the weight loss (wear), roughness, and coefficient of friction etc. This paper gives an idea of material selection, range of operating and loading conditions under dry and lubricated conditions for various applications and future direction.

A coating is deployed on the substrate by different deposition techniques to elevate the substrate's surface properties, such as chemical, mechanical, and tribological. The elevation in the properties of the substrate depends on elements used in coating powder. In this work, the effect and significance of rare earth elements on the substrate has been presented. The objective of the work is coating by different thermal spraying methods. From the literature survey on TSP, there is a significant increase in corrosion resistance than other material properties. The tribological properties of substrate material were analysed with and without the rare earth material in coating powder by various researcher’s work. It is found that very less or little researchers have explored rare earth material as a coating material. There are different areas in which these coatings are used for various applications like the turbine's blade, aero-engines, miniaturized electronics, display panels, and others. By using RE metals mechanical, physical, tribological, and thermal shock resistance of the substrate material increased considerably.

The superiority of nanosized filler particles in improving the elastic and fracture behavior of polymers, in comparison to microsized inclusions, has been substantiated by several experimental observations. Accurate modeling of crack propagation in such heterogeneous materials, however, involves resolution of complex crack topologies while taking into account the coalescence and branching of multiple cracks. Such complexity renders the traditional sharp crack modeling approaches, such as those based on the idea of partition of unity, to be of limited suitability, especially in 3D, since these involve explicit tracking of the evolving crack surfaces. Furthermore, standard two-phase continuum models, owing to their lack of the necessary length scale, are unable to capture the previously mentioned smaller is stronger size effect. In order to remedy these shortcomings, this contribution introduces an enhanced phase-field fracture model, wherein an interphase region around filler particles, as observed experimentally, having continuously varying or graded material properties is considered. Fracture behavior of the composite material can be controlled by means of the degree of grading employed in determining the elastic and fracture properties within the interphase region. An optimal combination of the graded interphase parameters yields a tougher macroscopic response, as observed in case of tougher interphases, in comparison to the one obtained with a standard phase-field fracture model, The appropriateness of the introduced technique for modeling a wide spectrum of experimentally observed fracture behaviors, depending upon the degree of adhesion between the filler and the matrix phases, is depicted by means of extensive numerical experimentation.

Microwave cladding is a cost-effective solution to improve surface properties of metallic components. It has developed as a technique for processing of an assortment of materials in the progressing years. In the immediate years this process has gained popularity as it helps in uniform heating throughout the material at the molecular level. The significant advantages of microwave cladding process are reduced production cost and less processing time. Microwaves have been utilized viably with critical points of interest, especially in food processing and chemical synthesis. They are furthermore observed to be proficient for processing polymers, polymeric composites, and ceramic composites. The science of interaction of microwaves with typically various materials is not yet investigated well; thus, there are difficulties in microwave processing of metal-based materials. This article gives an outline of major parts of microwave processing of metal-based materials and their interaction with metallic materials. The processing difficulties have been studied and advancements have been reported. The life of components exposed to severe tribological loading can be increased by a coating of appropriate material through cladding. The coating is generally obtained by partial dilution of the substrate and subsequent formation of metallurgical bonding between the substrate and the deposits.

Parallel and angular gear misalignments reduce effective contact area and increase contact stresses, which in turn accelerate gear surface fatigue failure. In the present study, experiments on gear tooth contact area by varying degree and extent of misalignment have been performed. Theoretical model to estimate contact area as a function of misalignment is proposed. A methodology to measure contact area using coordinate measuring machine (CMM) is also discussed. The results of effective contact area obtained from theoretical and experimental studies show good agreement. It is observed that in the case of axial and radial misalignments, the contact patch area reduces linearly in proportion to amount of misalignment while in case of angular misalignment it follows a non-linear behaviour. As far as the angular misalignment is concerned, the contact patch changes from rectangular to quadrilateral and finally to triangular shape depending upon angle of misalignment. At an angular misalignment of 9°, contact patch shifts from quadrilateral to triangular shape. Combined parallel and angular misalignments result in larger reduction in contact area as compared with individual axial, radial and angular misalignment.

FimH is a type I fimbrial lectin located at the tip of type-1 pili of Gram-negative uropathogenic Escherichia coli (UPEC) guiding its ability to adhere and infect urothelial cells. Accordingly, blocking FimH with small molecule inhibitor is considered as a promising new therapeutic alternative to treat urinary tract infections caused by UPEC. Herein, we report that compounds having the S-glycosidic bond (thiomannosides) had improved metabolic stability and plasma exposures when dosed orally. Especially compound 5h showed the potential to inhibit biofilm formation and also to disrupt the preformed biofilm. And compound 5h showed prophylactic effect in UTI model in mice.

Texturing of the surface is a technique to form the surfaces of the desired pattern. It is extensively used to alter the mechanical and tribological properties, such as increased fatigue strength, corrosion, wear resistance, anti-biofouling hydrophobicity and load-carrying capacity. To get these benefits, many researchers have studied the importance of textured parameters on metals and non-metals and revealed that un-optimized parameters might deteriorate the properties of the materials. These texture parameters may be dimple shape, depth, diameter, and density. Even though laser surface texturing widely used method, this review article articulates detailed information about surface texturing methods available to fabricate, surface texture characterization, merits, demerits, and applications of textured surfaces on metals and non-metals to enhance tribological performance.

Overhang-meshing gears, deflection of pinion/gear shaft, bearing wear, assembly error, poor adjustment of bearings and foundation are the reasons of misalignment in gear drives. In the present work, the misalignment effect on gearbox failure is investigated experimentally using vibration analysis. Misalignment between motor and gearbox is measured using laser alignment system (LAS). The effect of input shaft speed and load on the gearbox failure is also discussed. The misalignment effect primarily observes on the gearbox drive end taper roller bearing and distresses gear transmission. Physical and microscopic examinations of the dismantle gearbox confirm similar findings as observe from vibration spectrum. Severe damages in taper roller bearing (32206) and multiple pits on all the rollers and cone. The bearing cage is deformed badly due to overload and misalignment. The effect of bearing failure on gear’s damage is also investigated. Non-uniform contact patch is observed on the meshing gears in the plane of action. Misalignment results in scuffing failure on the pinion addendum and gear dedendum regions due to limited lubricant in the overstress region. At the end of the test, all the four seals appears safe, while the coupling spiders damage seriously.

Gears predominantly fail in contact fatigue mode (pitting/spall) due to combined rolling and sliding motion. Pitting initiation has been experimentally investigated by many researchers under different loading and operating conditions. The present work attempts to predict pitting and bending fatigue crack initiation along gear tooth profile using American Gear manufacturing Association (AGMA) design approach. The effect of heat treatment process (Through hardened and Case hardened) on gear fatigue life is also studied. The AGMA results for contact and bending stresses at pitch point are compared with FEA results and a close agreement is observed. The modeling results reveal that increase in load increases the chances of early pitting failure. Case hardening gears delays the pitting initiation on gear tooth surface, while it increases the chances of bending fatigue failure.The pinion addendum region shows better pitting resistance as compared with dedendum region. The highest probability of pitting /bending failure initiation is observed in single tooth contact region due to full load sharing andthe chance of contact fatigue failure is more in comparison to bending fatigue failure.

The focus of the present study is to investigate the scuffing phenomenon of EN 31(Pin) against EN 19(Disc) steel under dry running condition using pin-on-disc machine. Coefficient of friction (COF) and pin wear are experimentally measured for different combination of loads (10N-70N) and rotational speeds (200 rpm-2000 rpm). The speed and load at which transition to scuffing occur are also examined. It is observed that the wear resistance increases with sliding velocity for lower load, while at higher load it increases initially and then becomes stable at higher speed. The COF increases with sliding velocity at lower loads and then becomes steady, while at higher loads, the COF first increases with increase in speed and then decreases considerably. This abrupt decrease in friction coefficient is due to intense heat generation between the disc and the pin and the experiment is stopped due to higher noise and vibration. Archard's wear model is also used to validate the wear of pin at different loads and speeds. Experimentally measured pin wear shows higher value probably due to decreases in material hardness with increase in interface temperature.

In India, the transportation sector is growing rapidly and the number of vehicles on Indian roads is increasing at a very fast rate leading to overcrowded roads and noise pollution. The traffic scenario is typically different from other countries due to predominance of a variety of two-wheelers which has doubled in the last decade and forms a major chunk of heterogeneous volume of vehicles. Also tendency of not following the traffic norms and poor maintenance adds to the noise generation. In the present study, Multilayer feed forward back propagation (BP) neural network has been trained by Levenberg–Marquardt (L–M) algorithm to develop an Artificial Neural Network (ANN) model for predicting highway traffic noise. The developed ANN model is used to predict 10 Percentile exceeded sound level (L10) and Equivalent continuous sound level (Leq) in dB (A). The model input parameters are total vehicle volume/hour, percentage of heavy vehicles and average vehicle speed. The predicted highway noise descriptors, Leq and L10 from ANN approach and regression analysis have also been compared with the field measurement. The results show that the percentage difference is much less using ANN approach as compared to regression analysis. Further goodness-of-fit of the models against field data has been checked by statistical t-test at 5% significance level and proved the Artificial Neural Network (ANN) approach as a powerful technique for traffic noise modeling.

Background Alcohol use is a pervasive phenomenon among female sex workers and their clients. It affects their physical health and promotes high-risk behavior and consequently, sexually transmitted infections (STIs). Hence, we designed a study to find the factors associated with alcohol use among the female sex workers of Eastern Nepal. The prevalence of HIV high-risk behavior and STIs among sex workers was also recorded. Methods A cross sectional study was conducted in three commercial districts namely Sunsari, Morang and Jhapa of Eastern Nepal. All the FSWs who had been involved in commercial sex activity in the past six months were included in the study. Face-to-face interviews with 168-restaurant based and 42-street based female sex workers, who were identified through snowball sampling. Bivariate analyses were conducted using Chi–Square tests for categorical variables. Multivariate models were used to identify significant factors associated with alcohol use in the sex trade. Results Logistic regression analyses revealed that sex with intravenous drug user (IDUs) (AOR 2.275, 95% CI 1.266, 16.898), oral sex (AOR 3.261, 95% CI 1.166–9.121) and pregnancy (AOR 5.826, 95% CI 2.009, 16.898) were strongly associated with sexual encounter after consumption of alcohol. More than three fourths of the women were involved in at least one HIV high-risk behavior and more than 80% females had suffered from symptoms (past and present) of STIs. Conclusion HIV prevention efforts should focus on alcohol abuse, which can make the FSWs vulnerable to oral sex, accidental pregnancies, sexual encounters with IDUs.

Although adrenergic receptors (AR) and hyperhomocysteinemia (HHcy) are implicated in heart failure, their role in diabetic cardiomyopathy is not completely understood. We tested the hypothesis that glucose mediated depletion of beta2-AR and HHcy impair contractile function of cardiomyocytes leading to diabetic cardiomyopathy. To prove the hypothesis, cardiac function was assessed in twelve week male diabetic Ins2+/− Akita and C57BL/6J mice by echocardiography, pressure-volume loop and contractile function of cardiomyocytes. The results revealed cardiac dysfunction in Akita. To investigate the mechanism, the levels of beta2-AR, GLUT4, sercoplasmic reticulum calcium ATP-ase –isoform 2 (SERCA-2) and homocysteine (Hcy) metabolic enzymes -cystathionine beta synthase (CBS), cystathionine gamma lyase (CTH) and methyl tetrahydrofolate reductase (MTHFR) were determined in the heart. It revealed down regulation of beta2-AR, GLUT4, SERCA-2, CBS, CTH and MTHFR in Akita. Attenuation of beta2-AR in hyperglycemic condition was also confirmed in cardiomyocytes at in vitro level. Interestingly, the ex vivo treatment of cardiomyocytes with beta2-AR antagonist deteriorated whereas beta-AR agonist ameliorated contractile function. It points to the involvement of beta2-AR in diabetic cardiomyopathy. We conclude that degradation of beta2-AR and impairment of Hcy metabolism is implicated in diabetic cardiomyopathy.

Previously we have reported that hydrogen sulfide (H 2 S) protects against chronic heart failure, and elevated level of homocysteine (Hcy) called hyperhomocysteinemia (HHcy, a co-morbid condition) exacerbates diabetic cardiomyopathy. The generation of H 2 S from Hcy requires cystathionine γ -lyase (CBS) enzyme and mutation of CBS (CBS+/−) causes pathological cardiac remodeling. Since miR-133a (cardiac fibrosis) and β 2-adrenergic receptors ( β 2-AR: contractile dysfunction) are attenuated in diabetic hearts and contribute to cardiac remodeling, we hypothesize that inhibition of CBS induces HHcy and attenuates miR-133a and β 2-AR due to decreased production of H 2 S. To prove the hypothesis, we used C57BL/6 J (WT), CBS+/− with and without NaHS (a H 2 S donor, 30 μM/L in drinking water for 4 weeks) and measured the levels of miR-133a and β 2-AR by individual miR-133a assay, multiplex RT-PCR and Western blotting. Additionally, to assess the role of H 2 S in mitigation of glucose mediated inhibition of β 2-AR, we determined the levels of stimulatory G -protein coupled receptor (Gs: inducer of β 2-AR) and β 2-AR in HL1 cardiomyocytes treated with high glucose (25 mM D-glucose) and high glucose + H 2 S (30 μM) by RT-PCR flow cytometry and RT-PCR. The results revealed that both miR-133a and β 2-AR are down regulated in CBS+/− hearts. However, treatment with H 2 S improves the levels of miR-133a and β 2-AR. Similarly, Gs and β 2-AR are down regulated in high glucose treated cardiomyocytes and H 2 S ameliorates both Gs and β 2-AR. These findings elicit that H 2 S induces miR-133a and β 2-AR in HHcy hearts and ameliorates diabetic cardiomyopathy.

Hydrogen sulfide (H 2 S) has recently been identified as a regulator of various physiological events including vasodilation, angiogenesis, antiapoptotic, and cellular signaling. H 2 S leads to down-regulation of inflammatory responses and provides myocardial protection during acute myocardial infarction (MI). We previously reported that H 2 S inhibits antiangiogenic factors such as endostatin and angiostatin, leading to development of new vessels. We have shown that coronary vessels elicited vasoconstriction to acetylcholine (Ach) and revealed a phenomenon of vasospasm; we examined the role of hyperhomocysteinemia in coronary endothelial dysfunction, vessel wall thickness, and lumen narrowing, which leads to acute/chronic coronary vasospasm. We hypothesize that H 2 S eliminates vessel damage and improves endothelial function, which causes the elimination of coronary vaso-constriction. To verify this, MI was created in wild-type mice, which were treated with sodium hydrosulfide (NaHS, H 2 S donor) in drinking water and compared with untreated control mice. The echocardiography in mice treated with H 2 S showed improvement of heart function compared to untreated mice. The X-ray and Doppler blood flow measurements showed enhancement of cardiac-angiogenesis in mice treated with H 2 S. This observed cardio-protection was associated with an inhibition of anti-angiogenic proteins and stimulation of angiogenic factors. The endothelium-impaired arteries from MI mice were constricted in response to Ach, and this vasoconstriction was mitigated with NaHS supplementation. The level of endothelial nitric oxide synthase (eNOS) was lower in coronary artery in MI than of MI + NaHS mice. Treatment with NaHS increased the levels of Ach-induced NO generation in the coronary artery of MI mice. The results suggest that Ach induced coronary vasoconstriction in MI mice and this vasoconstriction was ameliorated by NaHS treatment. The mechanisms for the impairment of vascular function and therapeutic effects of NaHS may be related to the regulation of eNOS expression, NO availability and tissue homocysteine. We established that administration of NaHS at the time of MI ameliorated infarct size and preserved LV function during development of MI in mice, which also improved coronary endothelial function and promoted new vessel growth.