Integrated computational fluid dynamics and 1D process modelling for superheater region in recovery boiler

Superheaters are the last heat exchangers on the steam side in recovery boilers. Their performance is accountable for proficient recovery boiler operation. The objective of this work is to obtain thorough knowledge about the superheating process and material temperature distribution for superheater platens. The study includes the effects of 3D flue gas flow field in superheater region and generated steam properties in steam cycle. The detailed analysis for flue gas side and steam side is important for improving recovery boilers' energy efficiency, cost efficiency, safety and contribution for carbon neutral energy production. In this work, for the first time, a comprehensive 1D-process model (1D-PM) for superheated steam cycle is developed and linked with a full-scale 3D-CFD model of the superheater region flue gas flow. The developed 1D-PM is validated using reference data including mass and energy balance calculations, and measurements. The results reveal that first; the geometrical structures of headers, connecting pipes and superheater platens affect platen-wise steam distribution. Second, the integrated solution of the 3D flue gas flow field and platen heat flux distribution with the 1D-PM substantially affect both generated superheated steam properties and material temperature distribution. It is also found that the commonly used uniform heat flux distribution approach for superheating process is not accurate because it does not consider the effect of flue gas flow field in superheater region. This novel integration modelling approach is advantageous for trouble shooting, optimizing the performance of superheaters in recovery boiler and selecting their design margins for the future. It could also be applied for other large scale energy production units including industrial biomass fired boilers

Effect of morphology on densification study of nano – hydroxyapatite

Spherical, rod and fibrous morphology of Hydroxyapatite (HA) nanoparticles were considered to understand the densification behaviour at high temperature. Thermal analysis of as-received HA nanoparticles confirmed the phase transformation temperature for different morphologies. The phase stability was strictly deepened on morphology of HA nanoparticles. X – ray diffraction (XRD) pattern and Fourier transformation Infrared (FTIR) was studied to evaluate the crystal structure, phase and purity for different calcined powders and their sintered specimens. Spherical, rod and fibrous nano-HA morphology were stable up to 1200oC, 700oC and 1000oC, respectively, which were decomposed to beta tricalcium phosphate ( – TCP) beyond these critical temperatures. Dilatometric study of all green specimens prepared from such nanoparticles was conducted up to 1250oC to synchronize the sintering temperature. The densification behaviour was dramatically changed with respect to morphology when sintered at different temperatures; such as 700oC,900oC,1000oC, 1250oC, respectively. Scanning electron microscopic (SEM) image, apparent porosity and relative density were studied to justify the densification behaviour of HA nanoparticles

Radiographic evaluation of posterior tibial slope in ACL deficient Indian patients

Background: There are several studies which have investigated various osseous morphologic characteristics as they relate to ACL injury. Tibial slope, notch width, and notch width index are some. However, there does not appear to be consensus across studies. The aim of this study was to validate association between posterior tibial slope (PTS) and ACL injury in an ACL deficient knee of Indian patients.Methods: This retrospective cum prospective study was done at a tertiary hospital from June 2017 to May 2018. 40 patients were included. Inclusion criteria were documented evidence of ACL tear to the affected knee; no history of osteoarthritis; no history of rheumatoid arthritis; patients voluntarily consented for the use of their radiographs for the study. The assessment was completed with a true lateral view of the knee with full length leg and ankle. The functional tibial slope as described by Julliard et al was used to determine the PTS. The mean and standard deviation (SD) for medial PTS were measured. Demographic data like age, sex were collected and entered into a database.Results: 95% of patients were male. Mean age was 29.25. The mean PTS was 13.037 which is reasonably high as compared to normal while the standard deviation was 4.487 reflecting large amount of variation.Conclusions: Increased posterior tibial slope can be concluded as a significant risk factor in ACL injury which corroborates the findings of various previously published studies. The findings presented may help identify patients who are at greater risk of ACL injury.

Science, Technology and Innovation Equity and Inclusion in Electric Vehicle Sector

The rapid growth of the electric vehicle (EV) industry offers a unique chance to ensure that technological progress benefits all of society. This research paper centers on developing indicators to assess and encourage equity and inclusion in EV science, technology, and innovation. By establishing a comprehensive framework, this study aims to track progress, pinpoint areas for enhancement, and contribute to a more just and innovative future. The paper emphasizes clear goals, including increased workforce diversity, equitable EV technology access for marginalized communities, and fostering an inclusive innovation ecosystem. Collaboration with diverse stakeholders researchers, policymakers, industry experts, community representatives, and advocacy groups is crucial for an unbiased perspective. Key areas within the EV sector are focal points for equity and inclusion efforts, such as workforce diversity, research funding distribution, technology accessibility, and community engagement. To measure progress, indicators are developed, incorporating qualitative aspects. Targets and benchmarks are set for each indicator to promote a challenging yet achievable path toward equity. Regular monitoring and reporting provide insights into intervention effectiveness, guided by stakeholder feedback and iteration. Acknowledging and celebrating equity and inclusion achievements motivate sustained progress. Knowledge sharing and community collaboration promote collective growth and better understanding of best practices. This research paper offers a comprehensive guide to developing indicators that assess and promote equity and inclusion in the EV science, technology, and innovation sectors. Applying these indicators and strategies enables stakeholders to contribute to a more just and innovative future, ensuring that technological benefits are accessible to all members of society

Multiscale analysis of phonon mediated dissipation in crystalline solids

In this study, we develop a multiscale method to study intrinsic damping in nano-structure. Vibrational frequencies in the range of few GHz are considered. Deformation of the structure, at such high rates of vibration, results in a nonequilibrium phonon distribution. The condition of local equilibrium, as is often used in the existing mutli-scale approaches, no longer remains valid. The nonequilibrium phonon population results in the absorption of energy from the mechanical deformation and manifests itself as macroscopic dissipation. In this study, we develop constitutive relation for the stress tensor under such nonequilibrium condition. The stress tensor is decomposed into equilibrium and nonequilibrium components. The equilibrium component of the stress tensor is obtained using finite temperature quasi-harmonic methods (QHM). A visco-elastic relation is obtained for the nonequilibrium component. The different parameters, for the developed constitutive law, are obtained from the underlying interatomic potential. A modified QHM approach is used to obtain the stress relaxation rate. We first consider the case of ideal crystalline solids and study dissipation rate as a function of frequency and different strain state. Dissipation rate is computed in terms of dimensionless Q factor. The results from the analyses are compared with those obtained from nonequilibrium molecular dynamics simulations. The case of nano-structure is, then, considered. The role of surface on the Q factor is studied and compared with atomistic results