Minimum Weight Loss Research Articles

Effects of nitriding on salt spray corrosion resistance of additively manufactured 17-4 PH steels

• Study on effects of nitriding temperatures on NSS corrosion on AM 17-4 PH steel material. • Larger red rust formation was observed on as-built when compared with nitrided samples. • Higher volume of reduced grain size with precipitates was observed in the microstructure of nitrided samples. • Passive protective film with chromium and iron nitrides exhibited the best corrosion resistance at 580 o C. This work addresses the effects of varying nitriding temperatures of 530, 560 and 580 °C for 2 hours on corrosion resistance of additively manufactured (AM) 17-4 PH steels, using neutral salt spray (NSS) method for 104 hours. The morphological analysis indicated the presence of columnar grains along the built direction of additive manufacturing process. The refined grain size and the amount of the precipitates increased with an increasing nitriding temperature. The results of the analysis showed that a minimum weight loss was observed at 580 o C, due to the formation of passive oxide layer and nitrogen rich precipitates on the surface. The X-ray diffraction (XRD) showed the presence of these compounds: Cr 2 N, (Fe, Cr) 4 N, (Fe, Cr) 2-3 N, Fe 2 O 3 , FeOOH, and Cr 2 O 3 on the nitrided sample after the salt spray test.

Influence of synthesis methods (combustion and precipitation) on the formation of nanocrystalline CeO2, MgO, and NiO phase materials

Attempts were made to prepare CeO2, MgO, and NiO nanomaterials by combustion and precipitation methods using aniline as a fuel and KOH as a precipitating agent (with the aid of PEG as a surfactant). The formation of CeO2, Mg(OH)2, and NiO as combustion products, and CeO2, Mg(OH)2, and Ni(OH)2 as precipitated products were obtained in a single step. In a single-step process, both combustion and precipitation methods yield CeO2 materials with the significant differences in XRD structural features. The annealing (500 °C/4h) treatment enhances the nanocrystalline nature with the formation of pure MgO, NiO, and CeO2 phases. Variation in refined lattice parameters is noted for the present different materials. The color appearance of the as-prepared and annealed materials obtained by these methods is differentiated. The as-prepared Ni(OH)2 phase materials produced via precipitation with PEG and without PEG as surfactant show a quite major difference in the structural (a, c, and D values) and thermal (TG/DTA) features. The phase pure as-prepared combustion product of CeO2 materials shows a relatively minimum weight loss of 1.4%. A maximum weight loss of 33.9% was noted for the precipitated product of Mg(OH)2 phase materials reduced to 28.2% despite the formation of pure MgO phase materials upon annealing at 500 °C/4h at the end temperature, 1000 °C. The UV–Vis diffuse reflectance measurements exhibit a difference in the absorbance peak intensity and the Eg values calculated from the Tauc relation ranging from 1.65 to 5.42 eV for annealed MgO, NiO, and CeO2 phase materials. Significant changes in the NIR reflectance (<10 – 80%) values are seen in the 750–2500 nm regions for these nanomaterials owing to the difference in the color appearance of powder samples. From the NIR reflectance spectral study, we found that the MgO and CeO2 nanomaterials are suitable for NIR reflecting solar and color pigmentation applications owing to their higher (∼80%) NIR reflectance values in the NIR region.

Effect of Post-Harvest Treatments on Quality Characteristics of Carrots During Storage

Background: Carrot due to its versatility in culinary uses is considered to be one of the most preferred vegetable. The carrot in Pakistan ranks third among winter vegetables, but due to adoption of improper postharvest techniques and storage, it leads to a great reduction in its quality.&#x0D; Objective: The study was carried out to assess the effect of different treatments on quality characteristics of carrot.&#x0D; Methodology: The study was carried out at the Laboratory of Farm Structures, Sindh Agriculture University Tandojam, Pakistan. Freshly harvested mature carrots free from damage and fungal attack were obtained from field. The carrot samples were subjected to different post-harvest treatments i.e. 40 ºC hot water dip for 2 minutes, 50 ºC hot water dip for 2 minutes, 0.4% concentration of calcium chloride (CaCl2) dip for 2 minutes and tap water.&#x0D; Results: The results revealed that moisture content and firmness decreased with increasing storage duration, whereas weight loss, fungal incidence and total soluble solids increased with increasing storage duration. The carrots treated with 0.4% concentration of CaCl2 dip for 2 minutes had maximum moisture content (78.32%) and firmness (4.12 lbs), with minimum weight loss (41.33%), fungal incidence (38.14%) and total soluble solids (10.43%), followed by 40 ºC hot water dip for 2 minutes, 50 ºC hot water dip for 2 minutes and tap water.&#x0D; Conclusion: The carrots treated with 0.4% concentration of CaCl2 dip for 2 minutes showed better quality characteristics at the end of storage. The adoption of this treatment should therefore be encouraged in the developing countries for extending the quality characteristics of carrots.

EFFECT OF ALOE VERA GEL COATING ON POSTHARVEST FRUIT QUALITY OF STRAWBERRY FRUIT (FRAGERIA ANANASSA)

Current study was conducted in 2019 at Post Harvest Research Center, Ayub Agricultural Research Institute, Faisalabad, Pakistan and Institute of Horticultural Sciences, University of Agriculture, Faisalabad, Pakistan to address this problem of strawberry fruit where aloe vera gel coating was applied with different concentrations (0.1%, 1.5% and 2%) at 3°C to determine its possible effects on postharvest fruit quality and to increase the shelf life. Data were recorded on different fruit related parameters like fruit weight loss, fruit shape index, firmness, disease and decay %age, pH, TSS, titrateable acidity, vitamin-c content, reducing sugars, non-reducing sugars and total sugars. The results showed that application of 1.5% aloe vera gel significantly increased the shelf life as evidenced by minimum fruit weight loss (5.2%), higher fruit firmness (2.75%), less disease and decay (5.8%). However, TSS (8.16 °Brix), reducing sugars (2.98%), non-reducing sugars (2.59%) and total sugars (5.57%) were found maximum for control. Highest acidity (0.88%) and vitamin C contents (53.46 mg/100g) were found in fruits treated with 2% aloe vera gel. Moreover, lowest pH (4.41) was recorded in fruits coated with 2% aloe vera gel. Results of this study revealed that the potential of using aloe vera gel at 1.5% as a coating material proved to be better to prolong postharvest life as well as to maintain quality of strawberry fruits

Transforming municipal cotton waste into a multilayer fibre biocomposite with high strength

We analyzed the problematic textile fiber waste as potential precursor material to produce multilayer cotton fiber biocomposite. The properties of the products were better than the current dry bearing type particleboards and ordinary dry medium-density fiberboard in terms of the static bending strength (67.86 MPa), internal bonding strength (1.52 MPa) and water expansion rate (9.57%). The three-layer, four-layer and five-layer waste cotton fiber composite (WCFC) were tried in the experiment, the mechanical properties of the three-layer WCFC are insufficient, the five-layer WCFC is too thick and the four-layer WCFC had the best comprehensive performance. The cross-section morphology of the four-layer WCFC shows a dense structure with a high number of adhesives attached to the fiber. The hardness and stiffness of the four-layer cotton fiber composite enhanced by the high crystallinity of cellulose content, and several chemical bondings were presence in the composites. Minimum mass loss (30%) and thermal weight loss rate (0.70%/°C) was found for the four-layer WCFC. Overall, our findings suggested that the use of waste cotton fiber (WCF) to prepare biocomposite with desirable physical and chemical properties is feasible, and which can potentially be used as building material, furniture and automotive applications.

Long-term response of dragon fruit (Hylocereus undatus) to transformed rooting zone of a shallow soil improving yield, storage quality and profitability in a drought prone semi-arid agro-ecosystem

Agricultural crops especially fruit trees are constrained by edaphic stresses in shallow soils with low water retention and poor fertility. Therefore, interventions of shifting to trench planting for better root anchorage and replacing the filling soil were evaluated for 8 years in dragon fruit (Hylocereus undatus) cultivated in Deccan Plateau of peninsular India. When averaged for last 5-years, 44 % higher fruit yield (18.2 ± 1.0 Mg ha−1) was harvested from trees planted in trenches filled with 1:1 mixture (T-mixed) of native soil (loamy sand with 26.7 % stones (>2mm), field capacity, FC 0.20 cm3 cm−3; organic carbon, OC 0.17 %; Av-N 54.6 kg ha−1) and a black soil (clay 54.4 %; FC 0.42 cm3 cm−3; OC 0.70 %; Av-N 157.1 kg ha−1) than the recommended pit planting (12.4 ± 1.2 Mg ha−1). Improvements in fruit yields with trenches filled with black (T-black) and native (T-native) soil were 32 and 13 %, respectively. Yield losses (total– marketable yield) were reduced by 40, 20 and 18 % over pit method with T-mixed, T-black and T-native soil, respectively. Marketable quality attributes like fruit weight, fruit size metrics and pulp/peel content were further improved under T-mixed soil. Accumulation of total soluble solids (TSS), sugar content, phenolic and flavonoid compounds were higher in fruits from T-native soil. During storage, fruits from T-native soil and pit planting exhibited minimum physiological weight loss and retained more firmness, TSS, sugars, titratable acidity, phenolic-flavonoids contents, FARP and DPPH activities. T-mixed soil provided better hydrozone and nutrients for resilience of fruit plants while protecting from aeration problems envisaged in poorly drained black soils. With B:C ratio (1.85) and lower payback period (4-years), T-mixed soil showed superior economic viability. Therefore, soil management module of planting in trenches filled-in with mixture of native and black soils can be recommended to boost productivity of fruits from shallow soils under water scarce degraded regions without penalising agro-ecosystem.

Eco-friendly organic management of rust red flour beetle, Tribolium castaneum (Herbst) under stored conditions

The results showed that neem leaf powder was the most effective treatment with a record of the highest mean adult mortality of 67.22 per cent and also exhibited the lowest weight loss of 0.67 per cent after 60 days of treatment. It was followed by powders of Eucalyptus (58.89% &amp; 0.87%) and Tulsi (51.11% &amp; 0.80%). The least effectiveness of turmeric rhizome powder against the pest recording minimum adult mortality and maximum weight loss of 30.56% and 1.07% per cent respectively was noticed control against adult mortality (30.56 %), grain weight loss and adult emergence owing to T. castaneum. As a result, 1.5 g/100 g of grains of neem leaf powder can be recommended as a safe control method against T. castaneum in stored wheat. The overall mean adult mortality of T. castaneum in fenvalerate was 72.78 per cent. When it came to treating T. castneum with some inert materials, boric acid treatment was the most effective showed the 100 percent adult mortality, followed by coal ash (71.67 %) and cow dung ash (63.33 %) after 5 days of storage. There was minimum grain weight loss and least adult emergence was recorded in the treatment of coal ash and cow dung ash. Whereas sawdust resulted in the least effective treatment with mean adult mortality of (35.56 %), there was maximum adult emergence seen.

Physicochemical, Morphological, and Functional Characterization of Edible Anthocyanin-Enriched Aloevera Coatings on Fresh Figs (Ficus carica L.).

In the present investigation, Aloe vera gel (AVG)-based edible coatings enriched with anthocyanin were prepared. We investigated the effect of different formulations of aloe-vera-based edible coatings, such as neat AVG (T1), AVG with glycerol (T2), Aloe vera with 0.2% anthocyanin + glycerol (T3), and AVG with 0.5% anthocyanin + glycerol (T4), on the postharvest quality of fig (Ficus carica L.) fruits under refrigerated conditions (4 °C) for up to 12 days of storage with 2-day examination intervals. The results of the present study revealed that the T4 treatment was the most effective for reducing the weight loss in fig fruits throughout the storage period (~4%), followed by T3, T2, and T1. The minimum weight loss after 12 days of storage (3.76%) was recorded for the T4 treatment, followed by T3 (4.34%), which was significantly higher than that of uncoated fruit (~11%). The best quality attributes, such as the total soluble solids (TSS), titratable acidity (TA), and pH, were also demonstrated by the T3 and T4 treatments. The T4 coating caused a marginal change of 0.16 in the fruit titratable acidity, compared to the change of 0.33 in the untreated fruit control after 12 days of storage at 4 °C. Similarly, the total soluble solids in the T4-coated fruits increased marginally (0.43 °Brix) compared to the uncoated control fruits (>2 °Brix) after 12 days of storage at 4 °C. The results revealed that the incorporation of anthocyanin content into AVG is a promising technology for the development of active edible coatings to extend the shelf life of fig fruits.

Improvement on surface quality of 316L stainless steel fabricated by laser powder bed fusion via electrochemical polishing in NaNO3 solution

Poor surface quality necessitates polishing of the parts manufactured by laser powder bed fusion (LPBF) to meet the requirements of use and service. Electrochemical polishing is one of the effective post-treatment methods to reduce the surface roughness. In this manuscript, polishing behavior of 316L stainless steel fabricated by LPBF in the eco-friendly NaNO3 solution was investigated. Different electrochemical tests including current efficiency, open circuit potential, and polarization behavior were carried out in this solution to investigate the influence of section orientation on the electrochemical polishing behavior. Test results indicated that electrochemical dissolution of the transverse section is more difficult than the longitudinal section because of the near-equiaxed dendrites and smaller grains diameter. The electrochemical polishing experiments showed that the polished surface presents hollowed-out retiform structure which is not conducive for the reduction of surface roughness value at low current density and the roughness value significantly decreases with the increase of total quantity of electricity at high current density. The weight loss of the transverse section is smaller than that of the longitudinal section at all current densities and electric charges, but the difference decreased with increasing current density. The electrochemical polishing at the current density of 40 A·cm−2 resulted in maximum reduction of the surface roughness with minimum weight loss. Finally, interior surfaces with longitudinal section and transverse section were polished successfully. The roughness values decreased from 17.3 and 18.3 μm to 2.4 and 2.6 μm, respectively.

Influence of hardfacings on wear behavior of EN-42A steel in actual field conditions

ABSTRACT In agriculture, the wear significantly influences the working edges of the ploughshare blades. So any improvement in the life of the tillage tools will be of great significance. In the present work EN-42A steel, ploughshare blades were hardfaced by three different iron-based hardfacing alloys, designated as H1, H2, and H3 using manual metal arc welding technique with an aim to improve the abrasive wear behaviour of ploughshare blades. The full edge (120 mm) and half-edge (60 mm) of the ploughshare were overlaid in order to examine the influence of the overlaid area. The study reveals the bare EN-42A steel experienced maximum weight loss (103 g), indicating low abrasive wear resistance due to its soft ferritic and pearlitic structure. Hardfacings were found to be protective against abrasive wear, and H1 hardfacing has shown minimum weight loss (71 g), followed by H2 (84 g) and H3 (86 g) hardfacing. Wear rate indices (WRI) for H1, H2, and H3 hardfaced steel are found to be 1.45, 1.22, and 1.19, respectively. Better behaviour of H1 hardfacing is attributed to its high hardness, and presence of complex nanocarbides in the metal matrix. Full-edge hardfaced ploughshare blades indicated better abrasive wear resistance than the half-edge hardfaced blades.

Photocatalytic efficiency of sol–gel synthesized Mn‐doped TiO2 nanoparticles for degradation of brilliant green dye and mixture of dyes

AbstractThe Mn‐doped TiO2 nanoparticle photocatalysts have been prepared by a simple sol–gel method. 1, 3, and 5 mol% Mn‐doped TiO2 nanoparticles have been prepared by using a stoichiometric amount of manganese acetate and titanium isopropoxide as precursors of Mn and Ti respectively. The physico‐chemical characterization of the prepared samples has been studied by x‐ray diffraction (XRD), Brunauer–Emmett–Teller surface area analysis, field emission scanning electron microscope, energy dispersive x‐ray analysis, high‐resolution transmission electron microscopy, x‐ray photoelectron spectroscopy, Ultraviolet–visible spectroscopy, photoluminescence spectroscopy, Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). XRD study reveals the formation of pure anatase phase of TiO2 and decrease in crystalline size of TiO2 on increasing the Mn doping content. TGA reveals minimum weight loss in the high‐temperature region of 500–1,000°C, showing the thermal stability of the catalyst. FTIR study shows highly bonding in metal atoms. These samples have been tested for photocatalytic degradation of brilliant green dye. 5 mol% Mn‐doped TiO2 is having nearly four times more photocatalytic activity than pure TiO2. In addition, Mn‐doped TiO2 has shown excellent photodegradation of a mixture of three dyes namely, rhodamine B, brilliant green, and methylene blue.

Mechanical Properties and Unlubricated Sliding Wear Behavior Study of Silicon Nitride-Based Cermets

This article reports the mechanical properties and dry sliding wear behavior of conventionally sintered Si3N4–Mo–Si and Si3N4–Mo cermets, where 15 wt% of oxide additives have been added by varying the ratio of individual additives, namely, Y2O3 and Al2O3. It has been observed that wear depth, wear rate, and weight loss have increased with the increase in applied normal load. The effects of Si and oxide additives on tribological as well as mechanical properties have been investigated. The minimum wear depth, wear rate, and weight loss of 8.15 ± 0.25 μm, 0.13 × 10−3 mm3/m, and 0.001g have been found in Si3N4–Mo cermet with 10 wt% Y2O3 and 5 wt% Al2O3 as additive. The main wear mechanisms like abrasion, delamination, and formation of grooves are evident on the worn surface.

An experimental study on two body abrasive wear behavior of natural fiber reinforced hybrid polymer matrix composites using Taguchi analysis

In earlier days the synthetic fibre composite material was considerably used for the secondary structures of automobile and aircrafts. But by knowing the performance at critical and elevated conditions natural fiber reinforced polymer matrix composites have been receiving considerable attention as the attribute for synthetic fiber reinforced composites for its functional efficiency, tailorable properties and strength to weight ratio. In the present study, abrasive wear behavior of natural fibre reinforced hybrid polymer matrix composite was carried out using pin-on-disc wear testing rig for abaca, basalt and hybrid abaca- basalt fibre reinforced epoxy using L9 orthogonal array. The tests were carried out on silicon carbide paper with a grit size of 320 µm with varying parameters of Load, Speed, and Time. From the obtained results, it is concluded that the optimal parameters for minimum weight loss is observed at load 10 N, speed 200 rpm and time of 10 min for basalt fibre reinforced epoxy composite and the maximum weight loss is observed for abaca fibre reinforced epoxy composite at load 30 N, 300 rpm and time of 20 min. The results also reveal that the material composition is the most influencing factor affecting the weight loss of the specimen followed by load, time and speed for the adopted testing conditions.

Efficacy of liraglutide 3.0 mg treatment on weight loss in patients with weight regain after bariatric surgery

PurposeBariatric surgery, as Roux-en-Y gastric bypass (RYGB), laparoscopic gastric banding (LGB), and laparoscopic sleeve gastrectomy (LSG), is considered the gold standard treatment to achieve long-term weight loss in severe obesity. In patients who fail to maintain the achieved weight, pharmacological treatment may be required. Here, we reported our real-life experience on the efficacy of liraglutide therapy in 62 patients who regained weight after bariatric surgery.MethodsWe retrospectively evaluated 62 (60 F-2 M; mean age: 43.6 ± 9.9 years) patients received liraglutide for weight loss after bariatric surgery (17 RYGB, 22 LGB, and 23 LSG). Body mass index (BMI) before and after surgery was, respectively, of 45.4 ± 5.5 kg/m2 and 29.5 ± 4.9 kg/m2. Patients were followed up from 2016 until 2021. Liraglutide was administered after weight regain once-daily subcutaneously at starting dose of 0.6 mg and with weekly increases up to 3.0 mg. Treatments were administered when a weight regain of 10–15% occurred after reaching a minimum weight loss from bariatric surgery or if weight loss after bariatric surgery was unsatisfactory.ResultsAfter a mean of 70.7 ± 43.7 months from any bariatric surgery, all patients started liraglutide therapy. At this time, mean BMI was 34.2 ± 4.8 kg/m2 (mean increased BMI: 4.7 ± 2.8 kg/m2). After a mean of 10.5 ± 4.4 months from the beginning of liraglutide, 9 patients achieved normal weight (BMI 24.1 ± 0.9 kg/m2), and 28 were overweight (BMI 26.9 ± 1.6 kg/m2). Twenty patients achieved grade I (BMI 32.1 ± 1.5 kg/m2), 5 grade II (BMI 37.3 ± 2.0 kg/m2) obesity, and none had grade III obesity (mean BMI change: − 5.1 ± 2.5 kg/m2). The treatment was well tolerated, and no serious adverse events were recorded.ConclusionThese data confirm the efficacy and safety of liraglutide in patients who experienced weight regain after bariatric surgery. Considering the long-term follow-up, patients should be followed up regularly and the pharmacological treatment should be adapted to the weight fluctuations observed during the clinical history.Level of evidenceV. Opinions of authorities, based on descriptive studies, narrative reviews, clinical experience, or reports of expert committees.

Validation of a clinically relevant humanized mouse model for the safety assessment of 4-1BB agonists utomilumab and urelumab.

e14602 Background: Immunotherapy is proven to be powerful and effective in treating cancer. One of the strategies for the therapy is to boost a patient’s immune system by stimulating tumor necrosis factor receptors via the activation of 4-1BB (CD137) costimulatory molecule. Urelumab was the first 4-1BB agonist investigated in clinical trials and showed clinical promise but doses were limited by severe liver toxicity. Preclinical assessment of toxicity failed to predict the clinical safety outcome. Methods: To address the critical needs of in vivo evaluation of toxicity in a preclinical setting, we have developed an animal model using PBMC humanized mice to assess the safety of immunotherapy. In this model, agents targeting human immune system including monoclonal and bispecific antibodies can induce an acute response of cytokine release within hours of treatment and with some therapies a systemic response can manifest in tissue damage and lethality of mice days later. Results: The potential clinical relevance of the PBMC humanized mouse model was demonstrated using 4-1BB agonists urelumab and utomilumab. The antibody-treated PBMC humanized mice were evaluated daily for clinical score and assessed for clinical chemistry and liver histopathology at study terminus. Animals dosed with urelumab at 10 mg/kg exhibited body weight loss and underwent early euthanasia, while animals dosed with utomilumab survived to scheduled euthanasia with minimum body weight loss. Urelumab showed marked liver toxicity relative to utomilumab and controls with more necrosis in the tissue and higher mean ALT, AST and GLDH activities, and the tolerability of urelumab was increased by lowering the dose to 1 mg/kg. The differences captured by the humanized mouse model presented a safety profile similar to the findings about urelumab and utomilumab from the clinical trials. Utomilumab was well tolerated at the dose that caused severe toxicity for urelumab in patients, and the toxicity of urelumab could be reduced by lowering the dose. Conclusions: Our data suggest that the PBMC humanized mouse model could identify human 4-1BB agonists that caused potentially severe liver toxicity. Preclinical safety assessment using humanized mouse models as used for these studies could be an important step in the course of the development of novel immunotherapy for the safety of patients as well as mitigating drug development cost.

Study on fabrication technology and corrosion resistance of Fe-based amorphous alloy coatings by high-speed laser cladding

In this paper, the AME201 Fe-based amorphous alloy coating was prepared by ultra-high speed laser cladding on the surface of 27SiMn alloy steel. The effects of technological parameters on the surface morphology, micro-structure and dilution rate of coating. Corrosion resistance and weight loss of matrix, AME201Fe coating, 316L coating and Fe901 coating were studied by salt spray corrosion test. The results show that the thickness of AME201Fe coating is mostly affected by powder feeding, laser power and scanning speed have a huge impact on the width of coating, and the dilution rate increased from 0.13% to 29% with the change of laser power, nearly several hundreds of times. The results of salt spray test show that the AME201Fe coating has the minimum weight loss value at each stage compared with the matrix, 316L coating and Fe901 coating, which can play a good role in surface protection because of less internal defects and no grain boundary dislocations.

Microstructure, hardness, and wear properties of AA6061/WC nanocomposite fabricated by friction stir processing

Friction stir processing (FSP) is a solid-state microstructural modification technique that has recently become an effective tool to refine microstructures and improve the mechanical properties of metals. In the current study, optimization of FSP parameters, including tool rotational speed, transverse feed, number of passes, and tungsten carbide (WC) nanoparticle volume fractions on mechanical and wear properties of the fabricated AA6061/WC nanocomposite was studied. Optical microscopy and scanning electron microscopy are used for microstructural observations. The process parameters are optimized using the Taguchi technique for single responses towards microhardness and weight loss and the Desirability approach for both responses. The percentage contribution of process parameters is estimated using analysis of variance. The microstructure observation shows that the proper selection of FSP parameters leads to a homogeneous dispersion of the WC particles throughout the matrix, thereby producing a defect-free AA6061/WC nanocomposite without voids. Also, the severe plastic deformation and heat generation during FSP cause the breaking of coarse particles, WC particles, and porous holes and create an ultrafine grain-sized structure via dynamic recrystallization. The results indicated that the microhardness value of the processed composite was found to be 144 VHN, which is 39.81% higher than that of the base metal. Also, the weight loss of all samples decreased as compared to the base metal. Also, it can be observed that the number of passes is the most significant factor for microhardness, with a 40.1% contribution, and for minimum weight loss, the volume fraction is the most significant factor, with a 56.94% contribution. The optimum process parameter combination was found to be 1800 rpm rotation speed, 120 mm/min of transverse feed, 6% volume fraction, and 3 passes that resulted in obtaining optimum values for micro hardness and weight loss. The surface composite developed in this research is considered a suitable material for applications demanding lightweight and enhanced surface properties, including automotive, aerospace, marine, defense, and transportation industries.

Investigation on Corrosion Behaviour of LM25-SiCp Composite Using Taguchi Method

The aim of this investigation is to optimize the process parameters to obtain minimum corrosion rate and weight loss of Al/SiCp metal matrix composites. A Taguchi based grey relation analysis was carried out. The process parameters such as number of hours dipped in 3% NaCl solution, vol.% of SiCp and aging at 170°C for hours were considered. The working range of each process parameters were fixed based on minimum weight loss and low corrosion rate. The test was carried out using Taguchi based grey relationship analysis. Three factor three level L9 orthogonal array was used and output responses such as weight loss and corrosion rate were calculated. Based on the grey relationship analysis, the rank of each process parameters was calculated. Based on the F value, the vol. % of SiCp (38.42%) on the metal matrix composite followed by number of hours samples immersed in 3% NaCl solution (35.3%) and aging at 170°C for hours (25.78%) were found as influencing parameters on corrosion rate and weight loss. The surface of corroded samples was investigated and reported.

Contribution of Neuraminidase to the Efficacy of Seasonal Split Influenza Vaccines in the Ferret Model.

ABSTRACTSeasonal influenza vaccination takes into account primarily hemagglutinin (HA)-specific neutralizing antibody responses. However, the accumulation of substitutions in the antigenic regions of HA (i.e., antigenic drift) occasionally results in a mismatch between the vaccine and circulating strains. To prevent poor vaccine performance, we investigated whether an antigenically matched neuraminidase (NA) may compensate for reduced vaccine efficacy due to a mismatched HA. Ferrets were vaccinated twice with adjuvanted split inactivated influenza vaccines containing homologous HA and NA (vacH3N2), only homologous HA (vacH3N1), only homologous NA (vacH1N2), heterologous HA and NA (vacH1N1), or phosphate-buffered saline (vacPBS), followed by challenge with H3N2 virus (A/Netherlands/16190/1968). Ferrets vaccinated with homologous HA (vacH3N2 and vacH3N1) displayed minimum fever and weight loss compared to vacH1N1 and vacPBS ferrets, while ferrets vaccinated with NA-matched vacH1N2 displayed intermediate fever and weight loss. Vaccination with vacH1N2 further led to a reduction in virus shedding from the nose and undetectable virus titers in the lower respiratory tract, similarly to when the homologous vacH3N2 was used. Some protection was observed upon vacH1N1 vaccination, but this was not comparable to that observed for vacH1N2, again highlighting the important role of NA in vaccine-induced protection. These results illustrate that NA antibodies can prevent severe disease caused by influenza virus infection and that an antigenically matched NA in seasonal vaccines might prevent lower respiratory tract complications. This underlines the importance of considering NA during the yearly vaccine strain selection process, which may be particularly beneficial in seasons when the HA component of the vaccine is mismatched.IMPORTANCE Despite the availability of vaccines, influenza virus infections continue to cause substantial morbidity and mortality in humans. Currently available influenza vaccines take primarily the hemagglutinin (HA) into account, but the highly variable nature of this protein as a result of antigenic drift has led to a recurrent decline in vaccine effectiveness. While the protective effect of neuraminidase (NA) antibodies has been highlighted by several studies, there are no requirements with regard to quantity or quality of NA in licensed vaccines, and NA immunity remains largely unexploited. Since antigenic changes in HA and NA are thought to occur asynchronously, NA immunity could compensate for reduced vaccine efficacy when drift in HA occurs. By matching and mismatching the HA and NA components of monovalent split inactivated vaccines, we demonstrated the potential of NA immunity to protect against disease, virus replication in the lower respiratory tract, and virus shedding in the ferret model.

An experimental study on abrasive wear behaviour of WC-12Co and WC-20Cr₂C3-7Ni coatings

Wear is a critical problem and common in several mechanical components, and it reduces the service span of the machine. To prevent the wear is a challenging job, especially in adverse working conditions. Coating of hard metals prevents the components from wear and increases the machine's service life. This current work studied experimentally the abrasive wear behaviour of HVOF sprayed WC-12Co and WC-20Cr₂C3-7Ni coatings. X-ray diffraction (XRD) and scanning electron microscopy(SEM) was used to characterize corresponding coatings for phase identification and microstructural investigation. Vickers hardness and a pin on the disc tester were used for microstructure and abrasive wear study. The Silicon carbide abrasive media was used as a counter surface and mounted on the circular disc by a suitable adhesive. SEM images with 3-D morphology were used to identify worn-out surface wear mechanisms. The result indicates that WC-12Co coating possesses a comparatively dense microstructure due to a strong Co binder. The WC-12Co coatings display higher microhardness and wear resistance due to dense microstructure. WC-12Co coating reveals 39 % & 38% minimum weight loss than WC-20Cr₂C3-7 N coating at both 20 N and 40 N load WC-12Co coating shows a higher Coefficient of friction. Cutting and delamination were identified as main wear mechanisms.