Empirical optimization of corrosion rate for magnesium-chromium composites

363-368In this study, optimization of the corrosion rate (CR) of Mg-composites has been evaluated by varying the concentration, reinforcement percentage, and immersion time. As prime material, pure Mg is preferred for this research and chromium (Cr) consider as a reinforcing material with different percentages. CR (miles/yr) has been optimized by varying parameters such as reinforcement percentage as 3%, 5% and 7% including NaCl immersion medium (%) as 2.4%, 3.5% and 4.7% with immersion time (h) such as 48h, 72h and 96h. By using, DOF, minimal CR has been measured with the assistance of Minitab Software having ANOVA and Taguchi approaches. Optimized results reveal that the percentage of corrosion solution is influenced upto 66.10%, reinforcement percentage contributed to 27.56% and immersion time influenced upto 2.81%. An optimized combination of CR is 7wt. % Cr with 2.4% NaCl for 96h. However, microscopy results illustrate shallow crack boundaries in Mg/Cr composites due to its chemical reaction in alkaline solution

Influence of B4C on microstructural, mechanical and wear properties of Mg-based composite by two-step stir casting

This paper has been focused on the porosity, hardness, tensile and abrasion wear of Mg-based B4C composites developed by squeezed vacuum-based stir casting (SVSC) process by adding 3, 5, 7, 9 wt. % of B4C. Also, an electromagnetic stir casting has been used to synthesize similar composition specimens in comparison to the SVSC results. Additionally, electron microscopy has been used for analyzing the micro structural, fractographic and worn images of Mg-based B4C composites and to validate appropriate fabrication method. A tribo-test has been carried out by two-body abrasion condition at 20N and 30N load for as sliding distance of 100m and 5m/s of speed. The results reveal that the SVSC process produces homogeneously distributed B4C particles in Mg-matrix as compared to the electromagnetic stirring. The mechanical properties of Mg/B4C composites show their significant enhancement with the addition of B4C content in Mg-matrix. B4C composites show an increment of 33-48% of hardness as compared to Mg-matrix. Mg-matrix having 9 wt. % of B4C composite reveals the least tensile strength and fractured images show the cleavage planes, micro voids as well as micro cracks. Although, worn images shows oxidation and ploughing mechanism with the increase in load and depth of penetration in Mg-matrix B4C composites

Influence of B4C on microstructural, mechanical and wear properties of Mg-based composite by two-step stir casting

189-197This paper has been focused on the porosity, hardness, tensile and abrasion wear of Mg-based B4C composites developed by squeezed vacuum-based stir casting (SVSC) process by adding 3, 5, 7, 9 wt. % of B4C. Also, an electromagnetic stir casting has been used to synthesize similar composition specimens in comparison to the SVSC results. Additionally, electron microscopy has been used for analyzing the micro structural, fractographic and worn images of Mg-based B4C composites and to validate appropriate fabrication method. A tribo-test has been carried out by two-body abrasion condition at 20N and 30N load for as sliding distance of 100m and 5m/s of speed. The results reveal that the SVSC process produces homogeneously distributed B4C particles in Mg-matrix as compared to the electromagnetic stirring. The mechanical properties of Mg/B4C composites show their significant enhancement with the addition of B4C content in Mg-matrix. B4C composites show an increment of 33-48% of hardness as compared to Mg-matrix. Mg-matrix having 9 wt. % of B4C composite reveals the least tensile strength and fractured images show the cleavage planes, micro voids as well as micro cracks. Although, worn images shows oxidation and ploughing mechanism with the increase in load and depth of penetration in Mg-matrix B4C composites

Study of Abrasive Wear and Abrasion Heating of Mg and Al Matrix Composites Reinforced with B4C and Cr

This paper has focused on abrasive wear and abrasion heating of Mg- and Al-based B4C and Cr reinforced composites. The B4C and Cr have been added in 5% in the Mg- and Al-matrices and their composites have been fabricated by a squeezed stir casting method. The matrices and composites are evaluated and characterized for microstructure, hardness and X-ray diffraction. The abrasive wear and temperature rise during abrasive wear tests are carried out using a tribo-tester machine. The microstructure of Mg- and Al- matrices and their composites mainly show a uniform distribution of the B4C and Cr reinforcements. The hardness of the composites enhanced upto 72% by including B4C and 30 to 37% in the case of Cr composites in comparison to Mg- and Al- matrices. Temperature rise during abrasive is found more in the case of B4C reinforced composites in comparison to Cr amalgam composites and the abrasive resistance of B4C composite is high in comparison to Cr amalgam composites. The wear rate of boron carbide composites is approximately 2–6 times lower than the Mg matrix under different conditions. SEM image analysis mainly shows the cutting and ploughing material removal mechanism in abrasive wear

Experimental Investigation of Mechanical and Thermal Study of Mg/B4C/Cr Hybrid Composites

This study explores the investigation of enhanced mechanical and thermal properties of Mg/B4C/Cr hybrid composites having varying 3, 5, 7 wt. % of B4C and Cr reinforcements in Mg-matrix. The bottom pouring vacuum-based squeezed stir casting process is used to fabricate these composites. The Mg/B4C/Cr hybrid composites evaluate ultimate strength, elongation percentage, expansion coefficient, heat conductivity, hardness, and then compared with Mg/5B4C and Mg/5Cr composites. Each of Mg-based hybrid composites results indicates higher thermal conductivity and expansion coefficient than Mg/5B4C and Mg/5Cr composites. The tensile results reveal that the Mg/B4C/Cr hybrid composites show mixed morphologic behaviour of brittle-ductile while Mg/5B4C and Mg/5Cr composites are individually evident with brittle behaviour. The proper interfaces between Cr particles and Mg matrix illustrate reduced dislocations with efficient strength and thermal results. However, B4C particles present in the base matrix is liable for the effective hardness and ultimate strength in the Mg/B4C/Cr hybrid composites. In comparison with other composites (Mg/B4C and Mg/Cr), Mg/B4C/Cr hybrid composite shows efficient thermal conductivity with high thermal conductance which diverges towards the application of gas cylindrical liners

Study of Abrasive Wear and Abrasion Heating of Mg and Al Matrix Composites Reinforced with B4C and Cr

513-519This paper has focused on abrasive wear and abrasion heating of Mg- and Al-based B4C and Cr reinforced composites. The B4C and Cr have been added in 5% in the Mg- and Al-matrices and their composites have been fabricated by a squeezed stir casting method. The matrices and composites are evaluated and characterized for microstructure, hardness and X-ray diffraction. The abrasive wear and temperature rise during abrasive wear tests are carried out using a tribo-tester machine. The microstructure of Mg- and Al- matrices and their composites mainly show a uniform distribution of the B4C and Cr reinforcements. The hardness of the composites enhanced upto 72% by including B4C and 30 to 37% in the case of Cr composites in comparison to Mg- and Al- matrices. Temperature rise during abrasive is found more in the case of B4C reinforced composites in comparison to Cr amalgam composites and the abrasive resistance of B4C composite is high in comparison to Cr amalgam composites. The wear rate of boron carbide composites is approximately 2–6 times lower than the Mg matrix under different conditions. SEM image analysis mainly shows the cutting and ploughing material removal mechanism in abrasive wear

Empirical optimization of corrosion rate for magnesium-chromium composites

In this study, optimization of the corrosion rate (CR) of Mg-composites has been evaluated by varying the concentration, reinforcement percentage, and immersion time. As prime material, pure Mg is preferred for this research and chromium (Cr) consider as a reinforcing material with different percentages. CR (miles/yr) has been optimized by varying parameters such as reinforcement percentage as 3%, 5% and 7% including NaCl immersion medium (%) as 2.4%, 3.5% and 4.7% with immersion time (h) such as 48h, 72h and 96h. By using, DOF, minimal CR has been measured with the assistance of Minitab Software having ANOVA and Taguchi approaches. Optimized results reveal that the percentage of corrosion solution is influenced upto 66.10%, reinforcement percentage contributed to 27.56% and immersion time influenced upto 2.81%. An optimized combination of CR is 7wt. % Cr with 2.4% NaCl for 96h. However, microscopy results illustrate shallow crack boundaries in Mg/Cr composites due to its chemical reaction in alkaline solution

Experimental Investigation of Mechanical and Thermal Study of Mg/B4C/Cr Hybrid Composites

379-385This study explores the investigation of enhanced mechanical and thermal properties of Mg/B4C/Cr hybrid composites having varying 3, 5, 7 wt. % of B4C and Cr reinforcements in Mg-matrix. The bottom pouring vacuum-based squeezed stir casting process is used to fabricate these composites. The Mg/B4C/Cr hybrid composites evaluate ultimate strength, elongation percentage, expansion coefficient, heat conductivity, hardness, and then compared with Mg/5B4C and Mg/5Cr composites. Each of Mg-based hybrid composites results indicates higher thermal conductivity and expansion coefficient than Mg/5B4C and Mg/5Cr composites. The tensile results reveal that the Mg/B4C/Cr hybrid composites show mixed morphologic behaviour of brittle-ductile while Mg/5B4C and Mg/5Cr composites are individually evident with brittle behaviour. The proper interfaces between Cr particles and Mg matrix illustrate reduced dislocations with efficient strength and thermal results. However, B4C particles present in the base matrix is liable for the effective hardness and ultimate strength in the Mg/B4C/Cr hybrid composites. In comparison with other composites (Mg/B4C and Mg/Cr), Mg/B4C/Cr hybrid composite shows efficient thermal conductivity with high thermal conductance which diverges towards the application of gas cylindrical liners

Malnutrition among under Five Children in Uttarakhand

BACKGROUND: Globally more than one third of child deaths are attributable to under nutrition. Eighty percent of the world’s undernourished children live in 20 countries, with India being home to nearly 60 million children who are underweight. OBJECTIVE: This study aimed to assess malnutrition among under five children in a selected hospital of Dehradun, Uttarakhand. METHODOLOGY: A quantitative research approach was used with descriptive cross-sectional research design. Non probability convenient sampling technique was used to select 70 under five children who fulfilled the inclusion criteria. The data collection tools included Socio -demographic profile and Anthropometric assessment of the children. The data was analyzed based on objectives by using descriptive and inferential statistics. Data was analyzed using WHO anthroplus software and SPSS 21.0. RESULT: The result showed that out of 70 children 17.14% showed mild wasting, 18.57% showed moderate wasting and (21.43%) showed severe wasting. 11.43% children showed mild stunting, moderate stunting was present in 15.71% children and severe stunting was present in 27.14% children. 31.43% children were moderately underweight and 30% were severely underweight. CONCLUSION: The study concluded that majority of the children were malnourished

Sustainable production of Saussurea costus under different levels of nitrogen, phosphorus and potassium fertilizers in cold desert region of Western Himalaya

IntroductionSaussurea costus, an important critically endangered medicinal herb native to the Himalayan region, is commonly used in various ailments, viz. asthma, ulcer, inflammation, and stomach problems. In the international market, the dry roots and essential oil of S. costus has become an important drug. The lack of appropriate fertilizer dose recommendations is one of the limiting factors for its ex-situ conservation and large-scale cultivation, as plant nutrition is vital in determining crop growth and productivity. The study aimed to understand the comparative impact of different levels of fertilizer nutrients on growth, dry root and essential oil yield, and essential oil profile of S. costus.MethodsA field experiment was conducted in Himachal Pradesh, India's cold desert region (Lahaul valley), during 2020-21. The experiment comprised three levels of nitrogen (60, 90, and 120 kg ha-1), three levels of phosphorus (20, 40, 60 kg ha-1), and two levels of potassium (20 and 40 kg ha-1) in a factorial randomized block design.ResultsThe fertilizer application had an immense effect on growth attributes, root yield attributes, dry root yield, and essential oil yield over control. The treatment combination N120, P60, and K40 had the largest effect on the plant height, number of leaves per plant, leaf length and width, root length and diameter, dry matter per plant, dry root yield, and essential oil yield. However, the results were at par with the treatment comprising N90, P40, and K20. Dry root yield increased by 108.9%, and essential oil yield increased by 210.3% with fertilizer applications over unfertilized plots. The regression curve shows an increasing trend in dry root yield till N90, P40, and K20; after that, it nearly stabilized. The heat map showed that applying fertilizer significantly affected the chemical constituents of S. costus essential oil. Similarly, the plots fertilized with the highest level of NPK recorded the utmost value of available N, P, and K, as compared to unfertilized plots.DiscussionThe results emphasize that for sustainable cultivation of S. costus, the application of N90, P40, and K20 combinations is the most suitable one