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While chronologic age can be precisely defined, clinical manifestations of advanced age occur in different ways and at different rates across individuals. The observed phenotype of advanced age likely reflects a superposition of several biological aging mechanisms which have gained increasing attention as the world contends with an aging population. Even within the immune system, there are multiple age-associated biological mechanisms at play, including telomere dysfunction, epigenetic dysregulation, immune senescence programs, and mitochondrial dysfunction. These biological mechanisms have associated clinical syndromes, such as telomere dysfunction leading to short telomere syndrome (STS), and optimal patient management may require recognition of biologically based aging syndromes. Within the clinical context of lung transplantation, select immune aging mechanisms are particularly pronounced. Indeed, STS is increasingly recognized as an indication for lung transplantation. At the same time, common aging phenotypes may be evoked by the stress of transplantation because lung allografts face a potent immune response, necessitating higher levels of immune suppression and associated toxicities, relative to other solid organs. Age-associated conditions exacerbated by lung transplant include bone marrow suppression, herpes viral infections, liver cirrhosis, hypogammaglobulinemia, frailty, and cancer risk. This review aims to dissect the molecular mechanisms of immune aging and describe their clinical manifestations in the context of lung transplantation. While these mechanisms are more likely to manifest in the context of lung transplantation, this mechanism-based approach to clinical syndromes of immune aging has broad relevance to geriatric medicine.

Abstract To assess the impact of postnatal processing on placental DNA methylation, array data from flash-frozen placental tissue was compared to perfluorocarbon-immersed and formalin-fixed paraffin-embedded placental tissue. We observed that tissue exposed to perfluorocarbon showed no significant DNA methylation differences when compared to unprocessed tissue, while formalin processing altered the quality and reliability of the data produced on the DNA methylation array platform. Placental DNA methylation allows for the study of gene–environment interactions that influence the fetal environment and development. Our study highlights that placental post-processing techniques must be considered in the evaluation and interpretation of epigenetic studies.

Abstract Appropriate characterization of reservoir properties and investigation of the effect of these properties on microbial metabolism and oil recovery under simulated reservoir conditions can aid in development of a sustainable microbial enhanced oil recovery (MEOR) process. Our present study has unveiled the promising potential of the hyperthermophilic archaeon, identified as Thermococcus petroboostus sp. nov. 101C5, to positively influence the microenvironment within simulated oil reservoirs, by producing significant amounts of metabolites, such as biosurfactants, biopolymers, biomass, acids, solvents, gases. These MEOR desired metabolites were found to cause a series of desirable changes in the physicochemical properties of crude oil and reservoir rocks, thereby enhancing oil recovery. Furthermore, our study demonstrated that the microbial activity of 101C5 led to the mobilization of crude oil, consequently resulting in enhanced production rates and increased efficiency in simulated sand pack trials. 101C5 exhibited considerable potential as a versatile microorganism for MEOR applications across diverse reservoir conditions, mediating significant light as well as heavy oil recovery from Berea/carbonaceous nature of rock bearing intergranular/vugular/fracture porosity at extreme reservoir conditions characterized by high temperature (80–101 °C) and high pressure (700–1300 psi). Core flood study, which truly mimicked the reservoir conditions demonstrated 29.5% incremental oil recovery by 101C5 action from Berea sandstone at 900 psi and 96 °C, underscoring the potential of strain 101C5 for application in the depleted high temperature oil wells.

Diarrhoea is one of the major waterborne diseases spread through the faecal–oral route causing over 10 million cases and over 1,000 deaths per year in India. This study critically evaluates the interlinkage between bacteriological water quality, i.e. faecal coliforms and diarrhoea cases for the three pre-pandemic years 2017, 2018 and 2019 based on multiple sources. With around 17% of households tap water connectivity as of August 2019, the majority of the Indian population depends on raw groundwater (GW) and surface water sources. For this, faecal coliform (FC) levels in surface and GW have been mapped at district levels using data from India's National Water Quality Monitoring Programme. Health Management Information System's data on diarrhoea have been used to understand the monthly and district-wise variation of diarrhoea. The trends of FC, diarrhoea inpatient cases, and diarrhoea inpatient rates have been discussed. The analysis showed issues associated with the reliability and usefulness of these datasets with 43% of total India districts with no reported FC values for the study period. This study reveals a clear gap in the interlinkage between diarrhoea and bacteriological water quality with the unavailability of granular water quality data as a major challenge. HIGHLIGHTS Current diarrhoea-drinking water quality data fails to establish any interlinkage.; Access to treated tap water does not guarantee water safety and reduced diarrhoea.; No bacteriological water quality monitoring in more than 300 districts of India.; Issues with reliable and granular district-level water quality data.; The study suggests strengthening of monitoring mechanisms for credible data.;

Primary graft dysfunction (PGD) is a major risk factor for chronic lung allograft dysfunction (CLAD) following lung transplantation, but the mechanisms linking these pathologies are poorly understood. We hypothesized that the replicative stress induced by PGD would lead to erosion of telomeres, and that this telomere dysfunction could potentiate CLAD. In a longitudinal cohort of 72 lung transplant recipients with >6 years median follow-up time, we assessed tissue telomere length, PGD grade, and freedom from CLAD. Epithelial telomere length and fibrosis-associated gene expression were assessed on endobronchial biopsies taken at 2 - 4 weeks post-transplant by TeloFISH assay and nanoString digital RNA counting. Negative-binomial mixed-effects and Cox-proportional hazards models accounted for TeloFISH staining batch effects and subject characteristics including donor age. Increasing grade of PGD severity was associated with shorter airway epithelial telomere lengths (P = 0.01). Transcriptomic analysis of fibrosis-associated genes showed alteration in fibrotic pathways in airway tissue recovering from PGD, while telomere dysfunction was associated with inflammation and impaired remodeling. Shorter tissue telomere length was in turn associated with increased CLAD risk, with a hazard ratio of 1.89 (95% CI 1.16 - 3.06) per standard deviation decrease in airway telomere length, after adjusting for subject characteristics. PGD may accelerate telomere dysfunction, potentiating immune responses and dysregulated repair. Epithelial cell telomere dysfunction may represent one of several mechanisms linking PGD to CLAD.

Summary: Background: While many patients seem to recover from SARS-CoV-2 infections, many patients report experiencing SARS-CoV-2 symptoms for weeks or months after their acute COVID-19 ends, even developing new symptoms weeks after infection. These long-term effects are called post-acute sequelae of SARS-CoV-2 (PASC) or, more commonly, Long COVID. The overall prevalence of Long COVID is currently unknown, and tools are needed to help identify patients at risk for developing long COVID. Methods: A working group of the Rapid Acceleration of Diagnostics-radical (RADx-rad) program, comprised of individuals from various NIH institutes and centers, in collaboration with REsearching COVID to Enhance Recovery (RECOVER) developed and organized the Long COVID Computational Challenge (L3C), a community challenge aimed at incentivizing the broader scientific community to develop interpretable and accurate methods for identifying patients at risk of developing Long COVID. From August 2022 to December 2022, participants developed Long COVID risk prediction algorithms using the National COVID Cohort Collaborative (N3C) data enclave, a harmonized data repository from over 75 healthcare institutions from across the United States (U.S.). Findings: Over the course of the challenge, 74 teams designed and built 35 Long COVID prediction models using the N3C data enclave. The top 10 teams all scored above a 0.80 Area Under the Receiver Operator Curve (AUROC) with the highest scoring model achieving a mean AUROC of 0.895. Included in the top submission was a visualization dashboard that built timelines for each patient, updating the risk of a patient developing Long COVID in response to clinical events. Interpretation: As a result of L3C, federal reviewers identified multiple machine learning models that can be used to identify patients at risk for developing Long COVID. Many of the teams used approaches in their submissions which can be applied to future clinical prediction questions. Funding: Research reported in this RADx® Rad publication was supported by the National Institutes of Health. Timothy Bergquist, Johanna Loomba, and Emily Pfaff were supported by Axle Subcontract: NCATS-STSS-P00438.

This study assesses the impact of mergers and acquisitions on Environmental, Social, and Governance (ESG) performance and market value of acquiring companies operating in India. Data were collected and analyzed from 69 M&A announcements from January 2010 to June 2023, sourced from the Bloomberg database. The analysis reveals a positive correlation between the post-merger market value of acquiring firms and their ESG performance, indicating that an improvement in ESG factors is associated with increased market value after mergers. Additionally, a positive correlation was identified between acquiring companies’ post-merger ESG performance and their target firms’ pre-merger ESG performance. This finding suggests that when acquiring a target firm with high ESG performance, the acquirer is likely to experience an improvement in its own post-merger ESG performance. Moreover, both the post-merger market value and ESG performance of the acquirer are likely to improve with the profitability and size of firms but will have a negative impact based on the leverage components of the acquiring firms.

Abstract Breast cancer, the most frequent female malignancy, is often curable when detected at an early stage. The treatment of metastatic breast cancer is more challenging and may be unresponsive to conventional therapy. Immunotherapy is crucial for treating metastatic breast cancer, but its resistance is a major limitation. The tumor microenvironment (TME) is vital in modulating the immunotherapy response. Various tumor microenvironmental components, such as cancer-associated fibroblasts (CAFs), tumor-associated macrophages (TAMs), and myeloid-derived suppressor cells (MDSCs), are involved in TME modulation to cause immunotherapy resistance. This review highlights the role of stromal cells in modulating the breast tumor microenvironment, including the involvement of CAF-TAM interaction, alteration of tumor metabolism leading to immunotherapy failure, and other latest strategies, including high throughput genomic screening, single-cell and spatial omics techniques for identifying tumor immune genes regulating immunotherapy response. This review emphasizes the therapeutic approach to overcome breast cancer immune resistance through CAF reprogramming, modulation of TAM polarization, tumor metabolism, and genomic alterations.

The increased durability and performance features of polymer concrete panels have led to their widespread application in construction. The manufacturing of precise and effective techniques for identifying forms and flaws is vital to guarantee the high quality of these panels. To increase the accuracy of structure and defect-recognition in polymer concrete panels, this study presents a new Stochastic raven roosting optimization enhanced artificial neural network (SRRO-EANN) forecasting technique. The data sample used to assess the completed model fits the training dataset is referred to the test dataset. The Gaussian filter (GF) is a tool used in the pre-processing and Principal Component Analysis (PCA) feature extraction, leading to more effective utilization and understanding the defect capturing. The findings of the research indicate the effectiveness for the future development of forecasting technologies in the realm of quality control and building material inspection.

This study investigates the sustained engagement of Generation Z with fitness apps using the Theory of Consumption Values (TCV) to identify the key determinants influencing this behaviour. The research examines the relationship between continued app usage and various constructs, including physical, emotional, epistemic, social, and conditional values. A particular focus is placed on health-conscious tendencies as a potential influencing factor. Data were collected from 412 Generation Z individuals in Pune through purposive sampling and analysed using Smart PLS. The findings reveal significant associations between continued app usage and constructs related to physical appearance, enjoyment, learning, social interactions, and usage conditions. However, factors related to general health and affiliation were found to be non-significant. Contrary to intuitive expectations, health consciousness did not emerge as a moderating factor. This comprehensive analysis offers nuanced insights into the motivational factors driving Generation Z’s commitment to fitness apps. The study highlights the importance of physical, emotional, epistemic, social, and conditional values in sustaining app engagement, while noting the limited role of health consciousness. These findings provide valuable implications for app developers and marketers targeting this demographic, suggesting a focus on enhancing enjoyment, learning, social interaction, and usage conditions to foster continuous engagement. This study contributes to the existing literature by providing a comprehensive analysis of the factors driving sustained engagement with fitness apps among Generation Z, a demographic that has been relatively underexplored in this context, especially in India.

This research developed a theoretical framework based on the uses and gratification theory to investigate the intention to continue usage of Health and Fitness Apps (HFAs). In addition, this study explored how health valuation moderates the relationship between determinants and users’ intention to continue usage. A total of 447 HFA users’ data was collected from Delhi NCR, India through a purposive sampling technique. Partial least square-structure equation modeling was used to test the role of potential predictors influencing users’ behavioral intention to continue. The machine learning algorithms were employed to identify the features of importance. The results revealed that system quality, networkability, recordability, and task technology fit have a positive influence on hedonic motivation and utilitarian motivation. While information quality influences hedonic motivation but does not affect utilitarian motivation. Health valuation positively moderates the relationship between information quality, system quality, and networkability to intention to continue usage. We also observed that hedonic motivation emerged as a key predictor of users’ intention to continue usage of HFAs. The results would possibly offer useful recommendations for HFA developers, marketers, and health policymakers. The quality of fitness apps should be the primary concern of app developers. Furthermore, gamification can be incorporated into HFAs as it may influence the users’ hedonic motivations. The research contributes by developing a uses and gratification theory tailored for the HFAs. Additionally, this research incorporates hedonic and utilitarian motivation as mediating variables and health valuation as a moderator.

There is a growing need for small and medium-sized businesses (SMEs) to employ Integrated Marketing Communication (IMC) components to develop a robust brand-focused communications strategy given the present uncertain market circumstances and the consequent market volatility. For SMEs, the IMC pillars are crucial for building a robust strategic presence, which in turn improves company success. A descriptive cross-sectional study was employed to establish the link between IMC components and business performance. Data from 845 SME managers or owners were collected from India and were analyzed using PLS-SEM. The results show a strong correlation between the five dimensions of IMC performance and enhanced company performance. The results of the moderation analysis also show that Market Orientation has little effect on the connection between IMC features and Business Performance. In this article, we’ll look at how SMEs can improve their company performance plans by incorporating market orientation and integrated marketing communication (IMC). SMEs, especially those in the service industry, would benefit greatly from this study’s findings regarding the need to use this managerial approach to boost SME performance.

ABSTRACTAZD1222 (ChAdOx1 nCoV-19) is a replication-deficient adenoviral vectored coronavirus disease-19 (COVID-19) vaccine that is manufactured as SII-ChAdOx1 nCoV-19 by the Serum Institute of India Pvt Ltd following technology transfer from Oxford University/AstraZeneca. The non-inferiority of SII-ChAdOx1 nCoV-19 with AZD1222 was previously demonstrated in an observer-blind, phase 2/3 immuno-bridging study (trial registration: CTRI/2020/08/027170). In this analysis of immunogenicity and safety data 6 months post first vaccination (Day 180), 1,601 participants were randomized 3:1 to SII-ChAdOx1 nCoV-19 or AZD1222 (immunogenicity/reactogenicity cohort n = 401) and 3:1 to SII-ChAdOx1 nCoV-19 or placebo (safety cohort n = 1,200). Immunogenicity was measured by anti-severe acute respiratory syndrome coronavirus 2 spike (anti-S) binding immunoglobulin G and neutralizing antibody (nAb) titers. A decline in anti-S titers was observed in both vaccine groups, albeit with a greater decline in SII-ChAdOx1 nCoV-19 vaccinees (geometric mean titer [GMT] ratio [95% confidence interval (CI) of SII-ChAdOx1 nCoV-19 to AZD1222]: 0.60 [0.41–0.87]). Consistent similar decreases in nAb titers were observed between vaccine groups (GMT ratio [95% CI]: 0.88 [0.44–1.73]). No cases of severe COVID-19 were reported following vaccination, while one case was observed in the placebo group. No causally related serious adverse events were reported through 180 days. No thromboembolic or autoimmune adverse events of special interest were reported. Collectively, these data illustrate that SII-ChAdOx1 nCoV-19 maintained a high level of immunogenicity 6 months post-vaccination. SII-ChAdOx1 nCoV-19 was safe and well tolerated.

A long-term experiment was conducted during kharif seasons of2013 to 2020 at AICRP on Agrometeorology, VNMKV, Parbhani, to study the crop-weather relationship of soybean grown under four environments (27th SMW, 28th SMW, 29th SMW and 30th SMW) with three soybean varieties (MAUS-158, MAUS-71, and JS-335). Results indicated that soybean yield was significantly highest in (1541.4 kg ha-1) in the early sown crop, and it decreased with delay in sowing with the lowest yield (803.8 kg ha-1). Among the cultivars, MAUS-158 produced significantly the highest yield (1321.3 kg ha-1). Correlation analysis between weather parameters during different phases with the yield revealed that the vegetative and grain formation period of soybean were found to be the most sensitive to weather parameters, as the correlation coefficients with most of the weather parameters. Rainfall, number of rainy days, humidity and soil moisture had favorable effects while temperatures and sunshine duration had negative effects on the yield of soybean in the Marathwada region. Individual weather parameters during 50% flowering to maturity period could explain 40 to 55% variation in the soybean yield while the multiple regression developed all weather parameters during grain formation to physiological maturity period could explain up to 82% variation which could be used the predict the soybean yield in Marathwada region

In this study the performance analysis of ice plant is carried out experimentally for different concentration (0.2%, 0.3% and 0.4%) of TiO2 with (POE) lubricant using R-134a as a primary refrigerant in to the system. The performance analysis is carried out based on the parameters such as temperature of brine, pressure ratio, compressor work, refrigerating effect and COP. The pressure and temperature readings are recorded by using the pressure gauge and thermocouples fitted in the test rig for the analysis. The properties of refrigerant are recorded by using the LABVIEW software in computerised test rig. In this analysis it was observed that the minimum compressor work and maximum COP found at 0.4% concentration of TiO2 compared to other concentration. At 0.4% concentration of TiO2 nanoparticles, the efficacy was found to be superior to that of a mixture of R134a and pure lubricant, consuming 16.3% less compressor power and increasing COP by 34.2%. But the thermal conductivity and the density, of the mixture of R134a and nanolubricant are observed higher in comparison with the mixture of R134a and pure lubricant and are increases with increasing the concentration of TiO2.

The subplate is a transient brain structure which plays a key role in the maturation of the cerebral cortex. Altered brain growth and cortical development have been suggested in fetuses with complex congenital heart disease (CHD) in the third trimester. However, at an earlier gestation, the putative role of the subplate in altered brain development in CHD fetuses is poorly understood. This study aims to examine subplate growth (i.e., volume and thickness) and its relationship to cortical sulcal development in CHD fetuses compared with healthy fetuses by using 3D reconstructed fetal magnetic resonance imaging. We studied 260 fetuses, including 100 CHD fetuses (22.3-32 gestational weeks) and 160 healthy fetuses (19.6-31.9 gestational weeks). Compared with healthy fetuses, CHD fetuses had 1) decreased global and regional subplate volumes and 2) decreased subplate thickness in the right hemisphere overall, in frontal and temporal lobes, and insula. Compared with fetuses with two-ventricle CHD, those with single-ventricle CHD had reduced subplate volume and thickness in right occipital and temporal lobes. Finally, impaired subplate growth was associated with disturbances in cortical sulcal development in CHD fetuses. These findings suggested a potential mechanistic pathway and early biomarker for the third-trimester failure of brain development in fetuses with complex CHD.Significance statementOur findings provide an early biomarker for brain maturational failure in fetuses with congenital heart disease, which may guide the development of future prenatal interventions aimed at reducing neurological compromise of prenatal origin in this high-risk population.

Over the past decade, a growing body of research in adults has emphasized the role of the cerebellum in social and emotional cognition. This has been further supported by findings of delayed social and emotional development in toddlers with cerebellar injury during the fetal and newborn periods. However, the contributions of the cerebellum to social–emotional development in typically developing newborns are unclear. To bridge this gap in knowledge, we used multimodal MRI to investigate associations between cerebellar structure and function in 88 healthy neonates (mean ± sd of postmenstrual age, = 42.00 ± 1.91 weeks) and social–emotional development at 18-months assessed using the Infant-Toddler Social–Emotional Assessment (ITSEA) (mean age on ITSEA: 18.32 ± 1.19 months old). We found that cerebellar volume was not associated with ITSEA domain scores at 18 months. We further demonstrated cerebellar functional gradient (FGR) defined using principal component analysis (PCA) was associated with Externalizing domain (linear regression model, false-discovery-rate-adjusted p = 0.013). This cluster (FGR7) included the left dentate, right VI, left Vermis VIIIb, and right V lobules. Finally, we demonstrated that either structural or functional features of the cerebellum reliably predicted scores on the Externalizing and Internalizing domains (correlation between actual and predicted scores: for structural, Fisher’s z = 0.48 ± 0.01 for Internalizing, p = 0.01; for functional, Fisher’s z = 0.45 ± 0.01 for Externalizing, p = 0.02; with permutation test). Collectively, our findings suggest that the cerebellum plays an important role in social–emotional development during the critical early stages of life.

Abstract Due to waning immunity following primary immunization with COVID-19 vaccines, booster doses may be required. The present study assessed a heterologous booster of SII-NVX-CoV2373 (spike protein vaccine) in adults primed with viral vector and inactivated vaccines. In this Phase 3, observer-blind, randomized, active controlled study, a total of 372 adults primed with two doses of ChAdOx1 nCoV-19 (n = 186) or BBV152 (n = 186) at least six months ago, were randomized to receive a booster of SII-NVX-CoV2373 or control vaccine (homologous booster of ChAdOx1 nCoV-19 or BBV152). Anti-S IgG and neutralizing antibodies (nAbs) were assessed at days 1, 29, and 181. Non-inferiority (NI) of SII-NVX-CoV2373 to the control vaccine was assessed based on the ratio of geometric mean ELISA units (GMEU) of anti-S IgG and geometric mean titers (GMT) of nAbs (NI margin > 0.67) as well as seroresponse (≥ 2 fold-rise in titers) (NI margin −10%) at day 29. Safety was assessed throughout the study period. In both the ChAdOx1 nCoV-19 prime and BBV152 prime cohorts, 186 participants each received the study vaccines. In the ChAdOx1 nCoV-19 prime cohort, the GMEU ratio was 2.05 (95% CI 1.73, 2.43) and the GMT ratio was 1.89 (95% CI 1.55, 2.32) whereas the difference in the proportion of seroresponse was 49.32% (95% CI 36.49, 60.45) for anti-S IgG and 15% (95% CI 5.65, 25.05) for nAbs on day 29. In the BBV152 prime cohort, the GMEU ratio was 5.12 (95% CI 4.20, 6.24) and the GMT ratio was 4.80 (95% CI 3.76, 6.12) whereas the difference in the proportion of seroresponse was 74.08% (95% CI 63.24, 82.17) for anti-S IgG and 24.71% (95% CI 16.26, 34.62) for nAbs on day 29. The non-inferiority of SII-NVX-CoV2373 booster to the control vaccine for each prime cohort was met. SII-NVX-CoV2373 booster showed significantly higher immune responses than BBV152 homologous booster. On day 181, seroresponse rates were ≥ 70% in all the groups for both nAbs and anti-S IgG. Solicited adverse events reported were transient and mostly mild in severity in all the groups. No causally related SAE was reported. SII-NVX-CoV2373 as a heterologous booster induced non-inferior immune responses as compared to homologous boosters in adults primed with ChAdOx1 nCoV-19 and BBV152. SII-NVX-CoV2373 showed a numerically higher boosting effect than homologous boosters. The vaccine was also safe and well tolerated.

The probiotic potential of Shouchella clausii is widely recognized, but little is known about its adhesive properties. Hence, this study aims to investigate the adhesion potential and cell surface properties of four human-origin S. clausii strains (B619/R, B603/Nb, B106, and B637/Nm). We evaluated epithelial adhesion, Extracellular Matrix (ECM) binding, aggregation ability, and cell surface hydrophobicity and used genome analysis for validation. Our results demonstrate that adhesion capability is a strain-specific attribute, with significant variations observed among the four strains. B619/R, B603/Nb, and B106 displayed stronger adhesion properties than B637/Nm. Supplementary adhesion assays showed that B637/Nm displayed high hydrophobicity, significant auto-aggregation, and significant mucin-binding abilities. Conversely, B619/R, B603/Nb, and B106 had mildly hydrophobic surfaces and low aggregation abilities. Genome annotation revealed the presence of various adhesion proteins in four strains. Notably, the reduced adhesion potential of B637/Nm was supported by the absence of the cell wall surface anchor family protein (LPxTG motif), which is crucial for interactions with intestinal epithelial cells or mucus components. Further, docking studies provided insights into the interaction of adhesion proteins with gut mucins. These findings contribute to a better understanding of how S. clausii strains interact with the gut environment, facilitating the development of probiotic formulations tailored for improved gut health and well-being.

In the present investigation, the heat transfer and pressure drop performance of a tube in tube heat exchanger fitted with Bakelite helical screw tape and aluminum hemispherical cup shape with threaded core rod insert is experimentally reported for turbulent flow in individual and compound insertion cases. Performance is evaluated using water in the Reynolds number range of 8000 to 32000. For helical screw tape, the average Nusselt number ratios for augmented tube case to plain tube case (Nua/Nup) were found to be ranging between 2.51 – 2.7 along with average friction factor ratios (fa/ fp) ranging between 4.12 – 4.13. For cup shape inserts, the average Nusselt number ratios for augmented tube case to plain tube case (Nua/Nup) were reported between 1.38 – 1.62 along with friction factor ratios (fa/ fp) ranging between 4.93 – 5.44 . The average Nusselt number ratios (Nua/Nup) and friction factor ratios (fa/ fp) for two compound insertion cases are also reported by varying the cross-section of inserts for 1/3rd length of the heat exchanger and observed in the range of 2.26 – 2.65, and 4.06 – 4.8 respectively. For equal pumping power criteria, the average performance ratios (Nua/Nuc) are reported in the range of 1.02 -1.11 for helical screw tape, 0.6 – 0.67 for cup shape insert and 0.99 – 1.22 for two compound insertion caes.

The heat losses are mainly affects on the performance of cavity receiver of solar concentrator. In this paper, the experimental and numerical study is carried out for different heat losses from cylindrical cavity receiver of 0.35 m cavity diameter and 0.55 m opening diameter with wind skirt. The total and convection losses are studied experimentally to no wind conditions for the temperature range of 60 °C to 80 °C at 0°, 25°, 50°, 75° and 90° inclination angle of cavity receiver .The experimental set up mainly consists of cylindrical cavity receiver which is insulated with glass wool insulation to reduce the heat losses from outside surface.. The numerical analysis was carried out with Fluent Computational Fluid Dynamics (CFD) software, to study connective heat losses for no wind condition. The numerical results are compared with experimental results and found good agreement with maximum deviation of 13%. The effect of inclination angle of cavity receiver on total losses & convection losses shows that as the inclination angle increases from 0o to 90o, both losses decreased due to decreased in convective zone into the cavity receiver. The effect of operating temperature of cavity shows that as the temperature of cavity receiver increases, the total and convective losses goes on increasing. The present results are also compared to the convective losses obtained from M. Prakash. The convective loss from M. Prakash shows nearest prediction to both experimental and numerical results.