•Fiber laser-based micro engraving on an orthopedic implant for better bone fixation.•Critical process parameters have been explored that maintain groove quality features.•Groove width, debris, HAZ ...and recast layer thickness are the groove quality features.•GRA approach is used to examine the results for generating optimum process variables.•A feed-forward ANN model is developed to predict response characteristics values.•An attempt has been made to regulate groove quality during the engraving process.•Surgery complexity, cost and frequency of replacing old implants have been reduced.
It has been seen that there is a growing demand for the production of micron size grooves with a uniform flat surface, minimal heat-affected zone (HAZ) thickness, debris deposition, microcrack, microcavity, and recast layer thickness on orthopedic implants. In the present study, a multi-response optimization approach is adopted for fiber laser-based micro engraving to enhance groove characteristics and implant functionality during fixation. Grey relational analysis (GRA) is applied to analyze the experimental data sets and to decide key input factors' (pulse frequency, scanning speed, number of passes, laser power) level setting. These optimized data sets maintain groove quality (groove width, HAZ, debris deposition, recast layer thickness). Laser power and pulse frequency have been identified as the most significant factors for controlling groove quality. A neural network model has been developed and trained through experimental data sets. During analyzing the model, it has been recognized that the regression analysis score is very nearer to 1, and model performance is 2.45e-18. It represents its adaptability for determining the response quality characteristics when factor level settings are out of defined boundary. Improvements in groove quality are noticed in terms of minimal HAZ thickness, debris deposition, recast layer thickness, microvoids, and microcavity under optimum engraving conditions.
•Parametric influence on the joint strength of 0.7Al-0.4Cu sheets is studied.•Theoretical in detailed explanation of regression, ANN and ANFIS are explained.•Quadratic polynomial equation and its ...related ANOVA table are also depicted.•The method of selection of tuning factors in ANN and ANFIS are also revealed.•Overall comparison of prediction techniques for model validation is described with residual and parity plots.
Ultrasonic metal welding (USMW) is one of the solid state joining techniques which provides an alternative approach of joining soft and highly conductive materials like aluminum and copper in an impeccable way. Expectancy of good joint strength is an inevitable step to monitor, control and optimize the process parameters in this welding technique. In the light of this, regression model, artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS) are developed for predicting and simulating the joint strength for the USMW of Al-Cu sheets. The experiments are planned as per the full factorial design with three critical process parameters such as vibration amplitude, weld pressure and weld time to analyze tensile shear (TS) and T-peel (TP) failure loads. The analysis of variance (ANOVA) study explored that weld pressure has the most impact on the TS and TP followed by weld time and vibrational amplitude. Both of the artificial intelligence techniques were trained using the data attained from the experiment. Moreover, by comparing regression, ANN and ANFIS predicted results; ANFIS model provides less than 1% error and thus it can be considered as one of the reliable models to predict the weld strength in USMW process.
This research paper demonstrates the synthesis of zero-dimensional (0D) porous cupric oxide (CuO) nanoparticles by two different methods i.e. reflux and precipitation, followed by calcinations at ...different temperatures starting from 350 to 550 °C with an increment of 100 °C. The synthesized materials when calcined at different temperatures not only retain their structure, but also improve the crystalline nature. The maximum mean pore radius is found to be 4.15 nm for the sample calcined at 550 °C, synthesized by reflux technique, which is confirmed through SANS studies. The Cu (II)-O bond has been recorded in the range of 400 to 600 cm−1 and the peak of Cu-O has been observed at 603 cm−1 which is analyzed through FTIR spectra. The optical band gap of CuO is estimated to be 1.8 eV by diffused reflectance spectroscopic studies which indicate that the synthesized CuO nanoparticles are good photo-catalysts for phenol degradation within the wavelength range of visible-light. However, the polydispersity of the calcined materials gradually decreases with increase in temperature. It has been found from the Hall measurement that the synthesized CuO material is p-type in nature and I–V characteristics are linear in nature. As the Ohmic current mechanism is dominant, therefore the synthesized CuO material is an ideal candidate for sensor applications. The electrical conductivity of the CuO nanoparticles enhances when the measurement has been carried out in presence of phenol. It is seen that 450 °C calcined CuO shows highest degradation efficiency of phenol (98%) and phenol sensing.
Herein, a cost-effective and nontoxic method was employed for the synthesis of g-C3N4-FeVO4 heterojunction nanocomposite photocatalyst. In this method, first g-C3N4 was synthesized from urea by ...chemical free thermal treatment method. Then FeVO4 nanomaterial was introduced on its surface by co-precipitation method. The prepared nanocomposite was characterized by XRD, Raman, FTIR, XPS, FESEM, and UV-DRS to determine the crystalline phase, functionality, bonding, morphology and band gap. The synthesized nanomaterial was used for the photocatalytic degradation of highly carcinogenic rhodamine B (Rh B) dye from aqueous solution using solar-light irradiation. The composite has remarkably higher photocatalytic behavior compared to pure g-C3N4 and FeVO4. Again, the degradation rate constant of Rh B for g-C3N4-FeVO4 is remarkably more compare to its parent materials. The pattern of the heterojunction formation between g-C3N4 and FeVO4 helps to separate the electron pair thereby increased the photoactivity properties of the composite. Scavenger studies were also performed in order to understand the mechanism of photodegradation. It was observed that along with the electron and hole pairs generated by light photons, hydroxide radicals play an important role in the degradation mechanism.
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•Fe3O4 NPs decorated on g-C3N4 using Guava leaf extract as precipitating agent.•The synthetic material can effectively remove common synthetic dyes from water.•Very high uptake ...capacity was found for both CR and MB dyes.•Ecofriendly photocatalytic process was used for the regeneration of adsorbent.•The regenerated adsorbent can be effectively reused up to five successive cycles.
A greener and eco-friendly approach was developed to prepare magnetic g-C3N4-Fe3O4 nanocomposite adsorbent. Here, first g-C3N4 was prepared from melamine by using simple thermal treatment method. Then magnetic Fe3O4 nanoparticles were introduced on 2D surface of g-C3N4 using guava leaf extract. The formation, functionality, morphologies, surface area, magnetic power and bonding of the prepared material were analysed by XRD, FTIR, FESEM, TEM, BET, VSM and XPS analytical techniques. The formation of Fe3O4 phase on g-C3N4 surface was confirmed by XRD analysis. TEM images confirmed the formation of fine NPs on 2D g-C3N4 sheet. The surface area was found to be 92.32 m2/g with BJH average pore size distribution of 4 nm.The saturation magnetization value of g-C3N4-Fe3O4 was 15.12 emu/g. This shows superior magnetic property of the prepared material and thus can easily be separated from the treated water using external magnet. The prepared material was used for the removal of commonly used toxic Congo red (CR) and Methylene blue (MB) dyes from water using batch adsorption method. The adsorption of CR and MB on the surface of adsorbent was pH dependent. The maximum adsorption capacity of CR was found to be 194 mg/g at pH = 6 and MB was found to be 149 mg/g at pH = 8. The CR and MB adsorption process follows Pseudo- second-order kinetic and Langmuir isotherm models. The adsorbed CR and MB were recovered from the surface of adsorbent using chemical free photocatalytic irradiation process under visible light. The regenerated adsorbent was also reused for the further adsorption study and showed significant adsorption efficiency. This novel material can be considered as a promising adsorbent for CR and MB dyes with high adsorption efficiency, high stability, eco-friendly synthesis and easy to separate from the treated water with good reusability power.
Additive manufacturing (AM) route is a promising approach for fabricating complex and lightweight metallic structures that have applications in various sectors such as automotive, aerospace, and ...biomedical industries. Laser, electron beam, and electric arc are the common power sources available for AM. Out of different metal AM techniques, wire-feed additive manufacturing has been considered as a promising alternative for fabricating metallic parts for various applications. As it provides a high deposition rate, material utilization, density, and low cost with a low risk of contamination and porosity compared to powder-based raw material. Gas metal arc welding-based additive manufacturing (GMAW-AM) is a specific approach based on wire-feed AM. This technology uses a low-cost equipment which is suitable for fabricating components with large geometries and moderate structural complexity. These advantages attract the researchers and production industries for further developments in GMAW-AM to enhance its deposition performance, process capability, and applicability in various fields. The quality of metal deposited in GMAW-AM is generally represented by the surface form, dimensional quality, mechanical properties, relative density, hardness, etc. The present paper encompasses the research developments that occurred in the field of GMAW-AM in recent years. This review begins with the GMAW-AM procedure, performance capability, identification of factors affecting the deposition performance, and strategies adopted to overcome these issues. Several aspects such as mathematical modelling, optimization, key process parameters, and their combinations for a wide range of wire electrode material and percentage contributions are also reviewed and depicted in detail. Also, a comprehensive conclusion of this review, along with future perspectives, is explored subsequently. The current review work will help future researchers to select different wire materials and GMAW-AM parameters to achieve better performances. Lastly, several future research directions are suggested, specifically the need of a framework for GMAW-AM processes for fabricating quality products with minimum distortion.
To evaluate the beliefs held by the public regarding sexual health, pregnancy, and breastfeeding during COVID-19 era.
It was an online cross-sectional survey conducted through the Survey Monkey® ...platform and after proper ethical approval a self-designed questionnaire was circulated by the snowballing sampling technique through the Whatsapp platform.
1636 people respondent to the survey questionnaire. 63% of the participants mentioned that kissing could spread nCoV-SARS. Unprotected sexual intercourse with the spouse can cause infection spread, was reported by about one-third (35.9%). Nearly one-fifth (22%) thought that unprotected sexual intercourse with unknown partners/persons could not spread the infection. About half (49.7%) of the participants reported COVID-19 infection can be transmitted from mother to the child/fetus during the process of birth or during pregnancy and one-fifth (21.3%) of the participants reported going ahead with the Cesarean section if the mother is suspected of having or is confirmed to have COVID-19 infection. About one-fifth feared for risk of birth defects and abortion in case the mother is infected with COVID-19. 28% of the participants reported COVID-19 infection can be transmitted to newborn by breastfeeding.
The present study suggests that a significant proportion of people have misinformation about sexual intimacy, pregnancy, and breastfeeding in the ongoing pandemic which needs to be addressed.
Lightweighting of automotive body structures involves the ultrasonic spot welding (USW) of dissimilar sheets because of its low energy consumption in comparison to the traditional fusion welding ...process. In this study, AA3003 aluminum alloy to AISI 304 stainless steel with a copper interlayer was joined using USW technique at different weld times. The tensile shear strength of Al-to-SS joint with Cu interlayer (95.9 MPa) exhibited a higher value of 20.17% than SS-to-Al joint with Cu interlayer (79.8 MPa). The softer Al side experienced interfacial failure (IF) modes at lower weld times and at higher weld times, it gradually transformed to nugget pull-out failure (NPF). A comparative lower hardness value was obtained in Al-to-SS joint with Cu interlayer, demonstrating the generation high interface temperature and rigorous plastic deformation. The precipitation of brittle intermetallic compounds (IMCs) on the fracture surfaces severely concedes the reliability of the weld joints.
This review provides a broad overview of the relationship of personality with cardiovascular diseases (CVDs). There has been a sustained interest over the last half a century on the issue of ...relationship between personality traits and CVDs. Type A behavior was the initial focus of inquiry as it was observed that individuals who were competitive, hostile, and excessively driven were overrepresented among patients seeking treatment for CVDs and also were prone to develop coronary artery disease/syndrome. However, the research gradually expanded to assess the relationship of cardiac morbidity with various other personality facets. Furthermore, studies found out that negative effects (including anger and hostility) were also associated with adverse cardiovascular outcomes. Subsequently, a new personality entity named as the type D ‘distressed’ personality, which combined negative affectivity and social inhibition. type D personality then became the area of research and was demonstrated to be related with poorer cardiac outcomes. Interestingly, the results of various research studies are not equivocal, and hence, there are several critiques related to the current understanding of the link between personality construct and the risk of development as well as the outcome of CVDs. Furthermore, few personality traits such as optimism, conscientiousness, openness to experience, and curiosity have been found to be protective factors against development of CVDs and therefore are called ‘cardioprotective’ personality traits. A detailed discussion on the various aspects of personality in relation to CVDs along with a critical appraisal has been presented in this review.
The present experimental study introduced NTA-WAAM system for fabricating thin-layered structures using ER70S-6 wire. The study is directed towards determining the S
w
in the manufactured parts, ...considering varying level of TS (0.17, 0.19, and 0.24 m/min) and BL (2, 3, 7 layers). The S
w
is computed through image processing using canny edge detection method. Increasing the BL from 2 to 7 and reducing TS from 0.24 to 0.17 m/min, the resulting S
w
is increased from 1.05 to 2.69 mm. So with high BL, TS should be more to suitably control the S
w
because of high heat dissipation and low fluidity of molten pool. In addition to the morphological attributes, microstructural evolution, XRD, Rietveld refinement, tensile, and wear testing are incorporated to present the feasibility and stability of part fabricated through NTA-WAAM. Crystallite size, dislocation density, and residual stress are computed through XRD. It is observed that when approaching the top section from bottom zone of deposition, crystallite size is reduced from 23.43 to 21.85 nm, whereas dislocation density (2.83 × 10
12
to 6.52 × 10
12
m
−2
) and residual stress (−263.72 to −300.12 MPa) are increased. It indicates the adverse effect of crystallite size towards dislocation density and residual stress, which is primarily attributed to varying level of heat transfer during deposition. The deposit exhibits an ideally refined crystal structure than initial filler wire as χ
2
≈1 (from Rietveld analysis). Compressive residual stress development further improves the fabricated part's tensile characteristics. Formation of equiaxed dimples, characterises the ductile failure phenomena, whereas the enhancement in their dimensions reflects the improvement in ductility.
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