Present work investigates the heat transfer and melting behaviour of phase change material(PCM) in six enclosures(enclosure-1 to 6) filled with paraffin wax.Proposed enclosures are equipped with distinct arrangements ...Present work investigates the heat transfer and melting behaviour of phase change material(PCM) in six enclosures(enclosure-1 to 6) filled with paraffin wax.Proposed enclosures are equipped with distinct arrangements of the fins while keeping the fin's surface area equal in each case.Comparative analysis has been presented to recognize the suitable fin arrangements that facilitate improved heat transfer and melting rate of the PCM.Left wall of the enclosure is maintained isothermal for the temperature values 335 K,350 K and 365 K.Dimensionless length of the enclosure including fins is ranging between 0 and 1.Results have been illustrated through the estimation of important performance parameters such as energy absorbing capacity,melting rate,enhancement ratio,and Nusselt number.It has been found that melting time(to melt 100% of the PCM) is 60.5%less in enclosure-2(with two fins of equal length) as compared to the enclosure-1,having no fins.Keeping the fin surface area equal,if the longer fin is placed below the shorter fin(enclosure-3),melting time is further decreased by 14.1% as compared to enclosure-2.However,among all the configurations,enclosure-6 with wire-mesh fin structure exhibits minimum melting time which is 68.4% less as compared to the enclosure-1.Based on the findings,it may be concluded that fins are the main driving agent in the enclosure to transfer the heat from heated wall to the PCM.Proper design and positioning of the fins improve the heat transfer rate followed by melting of the PCM in the entire area of the enclosure.Evolution of the favourable vortices and natural convection current in the enclosure accelerate the melting phenomenon and help to reduce charging time.展开更多
Dry wear experiments provide an insight detail on how severely contacting surfaces change under unlubricated sliding condition. The theory of dry sliding wear is used for understanding mixed-lubrication regime in whic...Dry wear experiments provide an insight detail on how severely contacting surfaces change under unlubricated sliding condition. The theory of dry sliding wear is used for understanding mixed-lubrication regime in which asperity interactions play a significant role in controlling of the friction coefficient(f). The purpose of this work is to study the tribological behavior of AISI 304 steel in contact with AISI 52100 steel during wear. Both materials are used in rolling element bearings commanly. Experiments are carried out using a pin-on-disc tribometer under dry friction condition. The areal(three dimensional, 3D) topography parameters are measured using a 3D white light interferometer(WLI) with a 10× objective. After wear tests, wear mechanisms are analyzed utilizing scanning electron microscope(SEM). Factorial design with custom response surface design(C-RSD) is used to study the mutual effect of load and speed on response variables such as f and topography parameters. It is observed that the root mean square roughness(S_(q)) decreases with an increase in sliding time. Within the range of sliding time, S_(q) decreases with an increase in the normal load. Within the range of sliding speed and normal load, it is found that S_(q), mean summit curvature(S_(sc)), and root mean square slope(S_(dq)) are positively correlated with f. Whereas, negative correlation is found between f and correlation length(Sal), mean summit radius(R), and core roughness depth(S_(k)).展开更多
In this paper, a graphene-coated surface plasmon resonance sensor is designed for the examination of Rodent urine which is responsible for Leptospirosis bacteria. Rodent urine is considered as sensing medium. Graphene...In this paper, a graphene-coated surface plasmon resonance sensor is designed for the examination of Rodent urine which is responsible for Leptospirosis bacteria. Rodent urine is considered as sensing medium. Graphene surface is activated by phosphate-buffered saline solution for better attachment of Leptospirosis bacteria on its surface. Oliguria and Polyuria are the Rodent urine with high and low concentrations of Leptospirosis bacteria, respectively. The transfer matrix method is used for the formulation of reflection intensity of p-polarized light. The reflectance curves for angular interrogation are plotted and the results are obtained in terms of sensitivity, detection accuracy, and quality factor. The significantly high sensitivity and detection accuracy for Oliguria distinguishes it from Polyuria having lower sensitivity.展开更多
This work presents a surface plasmon resonance biosensor for the figure of merit enhancement by using Ga-doped zinc oxide(GZO),i.e.,nanostructured transparent conducting oxide as plasmonic material in place of metal a...This work presents a surface plasmon resonance biosensor for the figure of merit enhancement by using Ga-doped zinc oxide(GZO),i.e.,nanostructured transparent conducting oxide as plasmonic material in place of metal at the telecommunication wavelength.Two-dimentional graphene is used here as a biorecognition element(BRE)layer for stable and robust adsorption of biomolecules.This is possible due to stronger van der Waals forces between graphene’s hexagonal cells and carbon-like ring arrangement present in biomolecules.The proposed sensor shows improved biosensing due to fascinating electronic,optical,physical,and chemical properties of graphene.This work analyses the sensitivity,detection accuracy,and figure of merit for the GZO/graphene SPR sensor on using the dielectric layer in between the prism and GZO.The highest figure of merit of 366.7 RIU^(−1) is achieved for the proposed SPR biosensor on using the nanostructured GZO at the 3000 nm dielectric thickness.The proposed SPR biosensor can be used practically for sensing of larger size biomolecules with due availability of advanced techniques for the fabrication of the nanostructured GZO and graphene.展开更多
文摘Present work investigates the heat transfer and melting behaviour of phase change material(PCM) in six enclosures(enclosure-1 to 6) filled with paraffin wax.Proposed enclosures are equipped with distinct arrangements of the fins while keeping the fin's surface area equal in each case.Comparative analysis has been presented to recognize the suitable fin arrangements that facilitate improved heat transfer and melting rate of the PCM.Left wall of the enclosure is maintained isothermal for the temperature values 335 K,350 K and 365 K.Dimensionless length of the enclosure including fins is ranging between 0 and 1.Results have been illustrated through the estimation of important performance parameters such as energy absorbing capacity,melting rate,enhancement ratio,and Nusselt number.It has been found that melting time(to melt 100% of the PCM) is 60.5%less in enclosure-2(with two fins of equal length) as compared to the enclosure-1,having no fins.Keeping the fin surface area equal,if the longer fin is placed below the shorter fin(enclosure-3),melting time is further decreased by 14.1% as compared to enclosure-2.However,among all the configurations,enclosure-6 with wire-mesh fin structure exhibits minimum melting time which is 68.4% less as compared to the enclosure-1.Based on the findings,it may be concluded that fins are the main driving agent in the enclosure to transfer the heat from heated wall to the PCM.Proper design and positioning of the fins improve the heat transfer rate followed by melting of the PCM in the entire area of the enclosure.Evolution of the favourable vortices and natural convection current in the enclosure accelerate the melting phenomenon and help to reduce charging time.
文摘Dry wear experiments provide an insight detail on how severely contacting surfaces change under unlubricated sliding condition. The theory of dry sliding wear is used for understanding mixed-lubrication regime in which asperity interactions play a significant role in controlling of the friction coefficient(f). The purpose of this work is to study the tribological behavior of AISI 304 steel in contact with AISI 52100 steel during wear. Both materials are used in rolling element bearings commanly. Experiments are carried out using a pin-on-disc tribometer under dry friction condition. The areal(three dimensional, 3D) topography parameters are measured using a 3D white light interferometer(WLI) with a 10× objective. After wear tests, wear mechanisms are analyzed utilizing scanning electron microscope(SEM). Factorial design with custom response surface design(C-RSD) is used to study the mutual effect of load and speed on response variables such as f and topography parameters. It is observed that the root mean square roughness(S_(q)) decreases with an increase in sliding time. Within the range of sliding time, S_(q) decreases with an increase in the normal load. Within the range of sliding speed and normal load, it is found that S_(q), mean summit curvature(S_(sc)), and root mean square slope(S_(dq)) are positively correlated with f. Whereas, negative correlation is found between f and correlation length(Sal), mean summit radius(R), and core roughness depth(S_(k)).
基金Surjeet Raikwar is thankful to Dr.Abdul Kalam Technical University,Lucknow(India)for providing Research Grant Homi Bhabha Teaching Assistant Fellowship.
文摘In this paper, a graphene-coated surface plasmon resonance sensor is designed for the examination of Rodent urine which is responsible for Leptospirosis bacteria. Rodent urine is considered as sensing medium. Graphene surface is activated by phosphate-buffered saline solution for better attachment of Leptospirosis bacteria on its surface. Oliguria and Polyuria are the Rodent urine with high and low concentrations of Leptospirosis bacteria, respectively. The transfer matrix method is used for the formulation of reflection intensity of p-polarized light. The reflectance curves for angular interrogation are plotted and the results are obtained in terms of sensitivity, detection accuracy, and quality factor. The significantly high sensitivity and detection accuracy for Oliguria distinguishes it from Polyuria having lower sensitivity.
基金supported by the Board of Research in Nuclear Sciences(BRNS)(Grant No.34/14/10/2017-BRNS/34285)Department of Atomic Energy(DAE),and Government of India.
文摘This work presents a surface plasmon resonance biosensor for the figure of merit enhancement by using Ga-doped zinc oxide(GZO),i.e.,nanostructured transparent conducting oxide as plasmonic material in place of metal at the telecommunication wavelength.Two-dimentional graphene is used here as a biorecognition element(BRE)layer for stable and robust adsorption of biomolecules.This is possible due to stronger van der Waals forces between graphene’s hexagonal cells and carbon-like ring arrangement present in biomolecules.The proposed sensor shows improved biosensing due to fascinating electronic,optical,physical,and chemical properties of graphene.This work analyses the sensitivity,detection accuracy,and figure of merit for the GZO/graphene SPR sensor on using the dielectric layer in between the prism and GZO.The highest figure of merit of 366.7 RIU^(−1) is achieved for the proposed SPR biosensor on using the nanostructured GZO at the 3000 nm dielectric thickness.The proposed SPR biosensor can be used practically for sensing of larger size biomolecules with due availability of advanced techniques for the fabrication of the nanostructured GZO and graphene.
