| 1. |
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| 2. |
- Mishra, A., et al.
(författare)
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Stroke genetics informs drug discovery and risk prediction across ancestries
- 2022
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 611, s. 115-123
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Tidskriftsartikel (refereegranskat)abstract
- Previous genome-wide association studies (GWASs) of stroke - the second leading cause of death worldwide - were conducted predominantly in populations of European ancestry(1,2). Here, in cross-ancestry GWAS meta-analyses of 110,182 patients who have had a stroke (five ancestries, 33% non-European) and 1,503,898 control individuals, we identify association signals for stroke and its subtypes at 89 (61 new) independent loci: 60 in primary inverse-variance-weighted analyses and 29 in secondary meta-regression and multitrait analyses. On the basis of internal cross-ancestry validation and an independent follow-up in 89,084 additional cases of stroke (30% non-European) and 1,013,843 control individuals, 87% of the primary stroke risk loci and 60% of the secondary stroke risk loci were replicated (P < 0.05). Effect sizes were highly correlated across ancestries. Cross-ancestry fine-mapping, in silico mutagenesis analysis(3), and transcriptome-wide and proteome-wide association analyses revealed putative causal genes (such as SH3PXD2A and FURIN) and variants (such as at GRK5 and NOS3). Using a three-pronged approach(4), we provide genetic evidence for putative drug effects, highlighting F11, KLKB1, PROC, GP1BA, LAMC2 and VCAM1 as possible targets, with drugs already under investigation for stroke for F11 and PROC. A polygenic score integrating cross-ancestry and ancestry-specific stroke GWASs with vascular-risk factor GWASs (integrative polygenic scores) strongly predicted ischaemic stroke in populations of European, East Asian and African ancestry(5). Stroke genetic risk scores were predictive of ischaemic stroke independent of clinical risk factors in 52,600 clinical-trial participants with cardiometabolic disease. Our results provide insights to inform biology, reveal potential drug targets and derive genetic risk prediction tools across ancestries.
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| 3. |
- Ibanez, L., et al.
(författare)
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Multi-ancestry GWAS reveals excitotoxicity associated with outcome after ischaemic stroke
- 2022
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Ingår i: Brain. - : Oxford University Press (OUP). - 0006-8950 .- 1460-2156. ; 145:7, s. 2394-2406
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Tidskriftsartikel (refereegranskat)abstract
- During the first hours after stroke onset, neurological deficits can be highly unstable: some patients rapidly improve, while others deteriorate. This early neurological instability has a major impact on long-term outcome. Here, we aimed to determine the genetic architecture of early neurological instability measured by the difference between the National Institutes of Health Stroke Scale (NIHSS) within 6 h of stroke onset and NIHSS at 24 h. A total of 5876 individuals from seven countries (Spain, Finland, Poland, USA, Costa Rica, Mexico and Korea) were studied using a multi-ancestry meta-analyses. We found that 8.7% of NIHSS at 24 h of variance was explained by common genetic variations, and also that early neurological instability has a different genetic architecture from that of stroke risk. Eight loci (1p21.1, 1q42.2, 2p25.1, 2q31.2, 2q33.3, 5q33.2, 7p21.2 and 13q31.1) were genome-wide significant and explained 1.8% of the variability suggesting that additional variants influence early change in neurological deficits. We used functional genomics and bioinformatic annotation to identify the genes driving the association from each locus. Expression quantitative trait loci mapping and summary data-based Mendelian randomization indicate that ADAM23 (log Bayes factor = 5.41) was driving the association for 2q33.3. Gene-based analyses suggested that GRIA1 (log Bayes factor = 5.19), which is predominantly expressed in the brain, is the gene driving the association for the 5q33.2 locus. These analyses also nominated GNPAT (log Bayes factor = 7.64) ABCB5 (log Bayes factor = 5.97) for the 1p21.1 and 7p21.1 loci. Human brain single-nuclei RNA-sequencing indicates that the gene expression of ADAM23 and GRIA1 is enriched in neurons. ADAM23, a presynaptic protein and GRIA1, a protein subunit of the AMPA receptor, are part of a synaptic protein complex that modulates neuronal excitability. These data provide the first genetic evidence in humans that excitotoxicity may contribute to early neurological instability after acute ischaemic stroke. Ibanez et al. perform a multi-ancestry meta-analysis to investigate the genetic architecture of early stroke outcomes. Two of the eight genome-wide significant loci identified-ADAM23 and GRIA1-are involved in synaptic excitability, suggesting that excitotoxicity contributes to neurological instability after ischaemic stroke.
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| 4. |
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| 5. |
- Oonk, M. H. M., et al.
(författare)
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Radiotherapy Versus Inguinofemoral Lymphadenectomy as Treatment for Vulvar Cancer Patients With Micrometastases in the Sentinel Node: Results of GROINSS-V II
- 2021
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Ingår i: Journal of Clinical Oncology. - : American Society of Clinical Oncology (ASCO). - 0732-183X .- 1527-7755. ; 39:32
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE The Groningen International Study on Sentinel nodes in Vulvar cancer (GROINSS-V)-II investigated whether inguinofemoral radiotherapy is a safe alternative to inguinofemoral lymphadenectomy (IFL) in vulvar cancer patients with a metastatic sentinel node (SN). METHODS GROINSS-V-II was a prospective multicenter phase-II single-arm treatment trial, including patients with early-stage vulvar cancer (diameter < 4 cm) without signs of lymph node involvement at imaging, who had primary surgical treatment (local excision with SN biopsy). Where the SN was involved (metastasis of any size), inguinofemoral radiotherapy was given (50 Gy). The primary end point was isolated groin recurrence rate at 24 months. Stopping rules were defined for the occurrence of groin recurrences. RESULTS From December 2005 until October 2016, 1,535 eligible patients were registered. The SN showed metastasis in 322 (21.0%) patients. In June 2010, with 91 SN-positive patients included, the stopping rule was activated because the isolated groin recurrence rate in this group went above our predefined threshold. Among 10 patients with an isolated groin recurrence, nine had SN metastases > 2 mm and/or extracapsular spread. The protocol was amended so that those with SN macrometastases (> 2 mm) underwent standard of care (IFL), whereas patients with SN micrometastases (<= 2 mm) continued to receive inguinofemoral radiotherapy. Among 160 patients with SN micrometastases, 126 received inguinofemoral radiotherapy, with an ipsilateral isolated groin recurrence rate at 2 years of 1.6%. Among 162 patients with SN macrometastases, the isolated groin recurrence rate at 2 years was 22% in those who underwent radiotherapy, and 6.9% in those who underwent IFL (P = .011). Treatment-related morbidity after radiotherapy was less frequent compared with IFL. CONCLUSION Inguinofemoral radiotherapy is a safe alternative for IFL in patients with SN micrometastases, with minimal morbidity. For patients with SN macrometastasis, radiotherapy with a total dose of 50 Gy resulted in more isolated groin recurrences compared with IFL. (C) 2021 by American Society of Clinical Oncology
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| 6. |
- Heitsch, L., et al.
(författare)
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Early Neurological Change After Ischemic Stroke Is Associated With 90-Day Outcome
- 2021
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Ingår i: Stroke. - : Ovid Technologies (Wolters Kluwer Health). - 0039-2499 .- 1524-4628. ; 52:1, s. 132-141
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Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose: Large-scale observational studies of acute ischemic stroke (AIS) promise to reveal mechanisms underlying cerebral ischemia. However, meaningful quantitative phenotypes attainable in large patient populations are needed. We characterize a dynamic metric of AIS instability, defined by change in National Institutes of Health Stroke Scale score (NIHSS) from baseline to 24 hours baseline to 24 hours (NIHSSbaseline - NIHSS24hours = Delta NIHSS6-24h), to examine its relevance to AIS mechanisms and long-term outcomes. Methods: Patients with NIHSS prospectively recorded within 6 hours after onset and then 24 hours later were enrolled in the GENISIS study (Genetics of Early Neurological Instability After Ischemic Stroke). Stepwise linear regression determined variables that independently influenced Delta NIHSS6-24h. In a subcohort of tPA (alteplase)-treated patients with large vessel occlusion, the influence of early sustained recanalization and hemorrhagic transformation on Delta NIHSS6-24h was examined. Finally, the association of Delta NIHSS6-24h with 90-day favorable outcomes (modified Rankin Scale score 0-2) was assessed. Independent analysis was performed using data from the 2 NINDS-tPA stroke trials (National Institute of Neurological Disorders and Stroke rt-PA). Results: For 2555 patients with AIS, median baseline NIHSS was 9 (interquartile range, 4-16), and median Delta NIHSS6-24h was 2 (interquartile range, 0-5). In a multivariable model, baseline NIHSS, tPA-treatment, age, glucose, site, and systolic blood pressure independently predicted Delta NIHSS6-24h (R-2=0.15). In the large vessel occlusion subcohort, early sustained recanalization and hemorrhagic transformation increased the explained variance (R-2=0.27), but much of the variance remained unexplained. Delta NIHSS6-24h had a significant and independent association with 90-day favorable outcome. For the subjects in the 2 NINDS-tPA trials, Delta NIHSS3-24h was similarly associated with 90-day outcomes. Conclusions: The dynamic phenotype, Delta NIHSS6-24h, captures both explained and unexplained mechanisms involved in AIS and is significantly and independently associated with long-term outcomes. Thus, Delta NIHSS6-24h promises to be an easily obtainable and meaningful quantitative phenotype for large-scale genomic studies of AIS.
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| 7. |
- Van der Kolk, W. L., et al.
(författare)
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Unilateral inguinofemoral lymphadenectomy in patients with early-stage vulvar squamous cell carcinoma and a unilateral metastatic sentinel lymph node is safe
- 2022
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Ingår i: Gynecologic Oncology. - : Elsevier BV. - 0090-8258 .- 1095-6859. ; 167:1, s. 3-10
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Tidskriftsartikel (refereegranskat)abstract
- Objective. Optimal management of the contralateral groin in patients with early-stage vulvar squamous cell carcinoma (VSCC) and a metastatic unilateral inguinal sentinel lymph node (SN) is unclear. We analyzed patients who participated in GROINSS-V I or II to determine whether treatment of the contralateral groin can safely be omitted in patients with a unilateral metastatic SN.Methods. We selected the patients with a unilateral metastatic SN from the GROINSS-V I and II databases. We determined the incidence of contralateral additional non-SN metastases in patients with unilateral SN-metastasis who underwent bilateral inguinofemoral lymphadenectomy (IFL). In those who underwent only ipsilateral groin treatment or no further treatment, we determined the incidence of contralateral groin recurrences during follow-up.Results. Of 1912 patients with early-stage VSCC, 366 had a unilateral metastatic SN. Subsequently, 244 had an IFL or no treatment of the contralateral groin. In seven patients (7/244; 2.9% [95% CI: 1.4%-5.8%]) disease was di-agnosed in the contralateral groin: five had contralateral non-SN metastasis at IFL and two developed an isolated contralateral groin recurrence after no further treatment. Five of them had a primary tumor >= 30 mm. Bilateral ra-diotherapy was administered in 122 patients, of whom one (1/122; 0.8% [95% CI: 0.1%-4.5%]) had a contralateral groin recurrence.Conclusion. The risk of contralateral lymph node metastases in patients with early-stage VSCC and a unilateral metastatic SN is low. It appears safe to limit groin treatment to unilateral IFL or inguinofemoral radiotherapy in these cases.(c) 2022 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).
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| 8. |
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| 9. |
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| 10. |
- Muino, E., et al.
(författare)
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RP11-362K2.2:RP11-767I20.1 Genetic Variation Is Associated with Post-Reperfusion Therapy Parenchymal Hematoma. A GWAS Meta-Analysis
- 2021
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Ingår i: Journal of Clinical Medicine. - : MDPI AG. - 2077-0383. ; 10:14
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Tidskriftsartikel (refereegranskat)abstract
- Stroke is one of the most common causes of death and disability. Reperfusion therapies are the only treatment available during the acute phase of stroke. Due to recent clinical trials, these therapies may increase their frequency of use by extending the time-window administration, which may lead to an increase in complications such as hemorrhagic transformation, with parenchymal hematoma (PH) being the more severe subtype, associated with higher mortality and disability rates. Our aim was to find genetic risk factors associated with PH, as that could provide molecular targets/pathways for their prevention/treatment and study its genetic correlations to find traits sharing genetic background. We performed a GWAS and meta-analysis, following standard quality controls and association analysis (fastGWAS), adjusting age, NIHSS, and principal components. FUMA was used to annotate, prioritize, visualize, and interpret the meta-analysis results. The total number of patients in the meta-analysis was 2034 (216 cases and 1818 controls). We found rs79770152 having a genome-wide significant association (beta 0.09, p-value 3.90 x 10(-8)) located in the RP11-362K2.2:RP11-767I20.1 gene and a suggestive variant (rs13297983: beta 0.07, p-value 6.10 x 10(-8)) located in PCSK5 associated with PH occurrence. The genetic correlation showed a shared genetic background of PH with Alzheimer's disease and white matter hyperintensities. In addition, genes containing the ten most significant associations have been related to aggregated amyloid-beta, tau protein, white matter microstructure, inflammation, and matrix metalloproteinases.
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| 11. |
- Oonk, Maaike H. M., et al.
(författare)
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Radiotherapy Versus Inguinofemoral Lymphadenectomy as Treatment for Vulvar Cancer Patients With Micrometastases in the Sentinel Node : Results of GROINSS-V II
- 2021
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Ingår i: Journal of Clinical Oncology. - : Lippincott, Williams & Wilkins. - 0732-183X .- 1527-7755. ; 39:32, s. 3623-3632
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE The Groningen International Study on Sentinel nodes in Vulvar cancer (GROINSS-V)-II investigated whether inguinofemoral radiotherapy is a safe alternative to inguinofemoral lymphadenectomy (IFL) in vulvar cancer patients with a metastatic sentinel node (SN). METHODS GROINSS-V-II was a prospective multicenter phase-II single-arm treatment trial, including patients with early-stage vulvar cancer (diameter < 4 cm) without signs of lymph node involvement at imaging, who had primary surgical treatment (local excision with SN biopsy). Where the SN was involved (metastasis of any size), inguinofemoral radiotherapy was given (50 Gy). The primary end point was isolated groin recurrence rate at 24 months. Stopping rules were defined for the occurrence of groin recurrences. RESULTS From December 2005 until October 2016, 1,535 eligible patients were registered. The SN showed metastasis in 322 (21.0%) patients. In June 2010, with 91 SN-positive patients included, the stopping rule was activated because the isolated groin recurrence rate in this group went above our predefined threshold. Among 10 patients with an isolated groin recurrence, nine had SN metastases > 2 mm and/or extracapsular spread. The protocol was amended so that those with SN macrometastases (> 2 mm) underwent standard of care (IFL), whereas patients with SN micrometastases (<= 2 mm) continued to receive inguinofemoral radiotherapy. Among 160 patients with SN micrometastases, 126 received inguinofemoral radiotherapy, with an ipsilateral isolated groin recurrence rate at 2 years of 1.6%. Among 162 patients with SN macrometastases, the isolated groin recurrence rate at 2 years was 22% in those who underwent radiotherapy, and 6.9% in those who underwent IFL (P = .011). Treatment-related morbidity after radiotherapy was less frequent compared with IFL. CONCLUSION Inguinofemoral radiotherapy is a safe alternative for IFL in patients with SN micrometastases, with minimal morbidity. For patients with SN macrometastasis, radiotherapy with a total dose of 50 Gy resulted in more isolated groin recurrences compared with IFL.
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| 12. |
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| 13. |
- Powar, Satvasheel, et al.
(författare)
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Space Heating fins
- 2021
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Patent (populärvet., debatt m.m.)
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| 14. |
- Barthwal, M., et al.
(författare)
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Effect of Nanomaterial Inclusion in Phase Change Materials for Improving the Thermal Performance of Heat Storage : A Review
- 2021
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Ingår i: ACS Applied Energy Materials. - : American Chemical Society (ACS). - 2574-0962. ; 4:8, s. 7462-7480
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Tidskriftsartikel (refereegranskat)abstract
- Dispersion of nanoparticles is one of the potential solutions to improve the thermophysical properties of phase change (or transition) materials (PCMs) and enhance the performance of latent thermal energy storage (LTES) systems. The PCM ought to have a high latent heat of fusion, and zero or negligible coefficient of thermal expansion. A good PCM should have melting and solidification compatibility with negligible or zero subcooling, and it should not react with the common chemical reagents. The present known PCMs possess low thermal conductivity that results into a longer solidification and melting time of PCMs. In the past two decades, researchers have reported improved thermal conductivity and heat-storing capacity of PCMs employing graphite nanoparticles/fibers, carbon nanotubes/fibers, metal, and metal oxide nanoparticles. This work reviews the reported experimental and numerical studies describing the consequences of nanoparticle inclusions of various shapes and sizes on the thermal properties of the PCMs. This review attempts to make a consolidated database of the studies related to nanoadditive inclusion into PCMs for various applications. Graphene dispersed into PCM has resulted into 14 times thermal conductivity enhancement. As far as metal oxide nanoparticles are concerned, TiO2 and Al2O3 nanoparticles outperformed others. The compatibility between the nanoadditive and PCM is necessary to tailor favorable thermal properties. This work reviews numerous studies of different nanoparticle-PCM duos. © 2021 American Chemical Society.
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| 15. |
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| 16. |
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| 17. |
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| 18. |
- Saini, P., et al.
(författare)
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Cesaro fins parametric optimization for enhancement in the solidification performance of a latent heat storage system with combined fins, foam, and nanoparticle
- 2023
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Ingår i: Energy Reports. - 2352-4847. ; 9, s. 5670-5687
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Tidskriftsartikel (refereegranskat)abstract
- The use of Phase Change Materials (PCMs) for latent thermal energy storage enhances the availability of solar energy. PCMs can store a large amount of energy in a small volume using almost entirely isothermal processes. Despite this, the poor thermal conductivity of PCMs is a significant disadvantage of current PCMs, severely limiting their energy storage capabilities. As a result, the solidification/melting rates are reduced to an unacceptable level, and the system reaction time is increased unreasonably. By combining the novel fin arrangement, nanoparticles, and metal foam, the current study improved the solidification rate of the PCM in the Latent Heat Thermal Energy Storage System (LHTESS). LHTESS was numerically evaluated in ANSYS Fluent 18.1 using a solidification and melting model. The addition of cesaro fins, nanoparticles, and metal foam significantly improved PCM solidification in the LHTESS. PCM solidification time was reduced by 42.42% and 39.39% in Type-3 and Type-5 fin configurations, respectively, when compared to Type-4 fin configuration. Furthermore, a temperature difference of 27 K between the Heat Thermal Fluid (HTF) and the PCM ensures the best solidification performance. By incorporating nanoparticles into PCM and metal foam, the solidification time is reduced by 73.68%. Depending on the foam structure and volume fraction of the nanoparticles, dispersing nanoparticles in PCM with metal foam saves up to 75% of the time. © 2023 The Author(s)
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| 19. |
- Saini, P., et al.
(författare)
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Experimental and numerical investigation of a hybrid solar thermal-electric powered cooking oven
- 2023
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Ingår i: Energy. - : Elsevier Ltd. - 0360-5442 .- 1873-6785. ; 280
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Tidskriftsartikel (refereegranskat)abstract
- The rapid development in technology and changing food habits have drastically altered the cooking method in recent years. Electric ovens are dominating the cooking sector in bakeries, restaurants, and domestic cooking. India holds the second position in terms of revenue generated by the sales of cookers and ovens. The electrical energy requirements are also adding up with electricity-based cooking. In addition, solar energy-dependent solar cooking appliances are available in the market, but they come with their own set of merits and demerits. This paper discusses the new concept and development of an Electric-Solar hybrid cooking appliance. The implemented control mechanism in the fully-featured hybrid OTG (Oven, Toaster, & Griller) oven shows the simplicity and ease of using solar energy in conjunction with electrical energy. The experimental and numerical results show that the temperature distribution inside an electric-solar hybrid oven saves energy up to 51% and takes much less cooking time than electric ovens and solar cooking appliances when operating in hybrid mode. The STEPCO (Solar Thermal-Electric Powered Cooking Oven) oven has demonstrated potential for a relatively quick return on investment, with a payback period of around 2.3 years in hybrid mode and 3.7 years in solar mode. Experimental testing has shown that the hybrid mode of the STEPCO oven achieves an impressive efficiency of 63%, which is significantly higher than that of the electric and solar modes, which are only 35% and 4.0%, respectively. Additionally, the STEPCO oven has the environmental benefit of emitting very little CO2 during the cooking process when used in hybrid mode and zero CO2 emissions when used in solar mode. © 2023
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| 20. |
- Saini, P., et al.
(författare)
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Performance enhancement of fin and tube heat exchanger employing curved delta winglet vortex generator with circular punched holes
- 2023
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Ingår i: International Journal of Thermofluids. - : Elsevier B.V.. - 2666-2027. ; 20
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Tidskriftsartikel (refereegranskat)abstract
- The generation of vortices has recently gained attention as a potential passive technique for improving air-side heat transfer in a fin and tube heat exchanger. This study proposes novel configurations of a curved delta winglet vortex generator (CDWVG) with and without circular holes to improve heat transfer in FTHEs. The present study utilizes a three-dimensional numerical analysis to investigate the thermal-hydraulic performance analysis of fin and tube heat exchanger (FTHE) with curved delta winglet vortex generators (CDWVG) with or without circular holes, operating across a wide Reynolds number range (i.e., from 400 to 2000). In addition to being arranged in vertical and horizontal configurations, the CDWVGs are oriented in the same way as the flow direction. Therefore, the pressure distribution, temperature distribution, and flow structure distribution of an FTHE with a four-in-line circular tube configuration are analyzed and compared between FTHE without vortex generator (VG) and five different configurations of CDWVG (i.e., CDWVG without hole, CDWVG with 1 hole, CDWVG with 2 holes, CDWVG with 3 holes and CDWVG with 6 holes). The pressure drop (ΔP), London area goodness factor (LAGF) (j/f), Nusselt number (Nu), and Colburn factor (j) are also used to evaluate the thermo-hydraulic performance of FTHE. The FHTE performance with CDWVGs can be affected by the number of punched holes, which is evaluated using a dimensionless number including Performance Evaluation Criteria (PEC), Colburn factor, etc. The thermo-hydraulic efficiency of the FTHE is improved significantly by using CDWVGs with circular punched holes. Nusselt number decreases across all the VG configurations (i.e., CDWVG without hole, CDWVG with 1 hole, CDWVG with 2 holes, CDWVG with 3 holes, and CDWVG with 6 holes) due to the lower flow resistance. Compared to other CDWVG configurations, the 6-hole configuration of CDWVG is the most effective. The Nusselt number of CDWVG with 6 holes increases by 77.25% and 42.51% at Reynolds numbers of 400 and 2000, with respect to fin and tube heat exchangers without vortex generator, respectively. On the other hand, friction is decreased by 5.11%. Therefore, when considering the London area goodness factor, CDWVG with six holes is found to be superior to other CDWVG configurations. © 2023 The Authors
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| 21. |
- Saini, P., et al.
(författare)
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Performance enhancement of fin and tube heat exchanger employing curved trapezoidal winglet vortex generator with circular punched holes
- 2023
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Ingår i: International Journal of Heat and Mass Transfer. - : Elsevier BV. - 0017-9310 .- 1879-2189. ; 209
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Tidskriftsartikel (refereegranskat)abstract
- Vortex generation is a potential passive technology for increasing the heat transfer rate in the air side of fin and tube heat exchangers (FTHEs). This study proposes novel configurations of a curved trapezoidal winglet vortex generator (CTWVG) with and without circular holes to improve heat transfer in FTHEs. As per the literature, the streamlined form of the trapezoidal winglet demonstrates high heat transfer enhancement with low flow loss and pressure drop. But still, different design configurations are possible to augment the heat transfer characteristics of CTWVG further. The current study investigates the novel configurations of CTWVG (i.e., CTWVG without hole, CTWVG with 1 hole, CTWVG with 2 holes, CTWVG with 3 holes and CTWVG with 6 holes). A three-dimensional computational model is utilized to evaluate the thermal-hydraulic efficiency of FTHEs fitted with CTWVGs with or without circular holes for Reynolds numbers ranging from 400 to 2000. A common flow-down configuration of the CTWVG with circular tubes array is used to reduce the wake region. The thermo-hydraulic performance and flow structure of FTHE with four inline circular tube configurations are compared without VG and CTWVG with or without holes. Pressure drop (ΔP), Nusselt number (Nu), friction factor (f), Colburn factor (j), and London area goodness factor (j/f) are used for the thermal-hydraulic performance comparison. Results show that the number of punched holes has an impact on the FTHE performance, which is measured using a dimensionless number as performance evaluation criteria (i.e., (j/jo)/(f/fo)). CTWVGs with circular punched holes significantly increase the FTHE's thermo-hydraulic performance. The results indicate that the flow resistance is reduced in all cases (i.e., VG with no holes, VG with 6 holes, VG with 3 holes, VG with 2 holes, and VG with 1 hole) with a minor decrease in the Nusselt number. The CTWVG with six holes performs better than other CTWVG configurations. At Reynolds numbers 400 and 2000, the Nusselt number for CTWVG with six holes enhanced by 75.25% and 40.10%; pressure drop increased by 107.88% and 125.51%, respectively. On the other hand, friction is reduced by a factor of 8.1% in CTWVG with 6 holes compared to CTWVG without holes. The CTWVG with six holes performs better than other CTWVG configurations reported in the literature [48,54]. HTPF has increased by 30.96% (compared to rectangular winglet [48]) and 27.69% (compared to curved rectangular winglet [54]) with respect to values reported in the literature. The London area goodness factor (LAGF) has been increased by 275% compared to Modi et al. [48]. © 2023
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| 22. |
- Saini, P., et al.
(författare)
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Performance evaluation of a parabolic trough collector with a uniform helical wire coil flow insert
- 2024
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Ingår i: Results in Engineering (RINENG). - : Elsevier. - 2590-1230. ; 21
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Tidskriftsartikel (refereegranskat)abstract
- Solar energy is an extremely useful and dependable renewable energy source for meeting our society's diverse energy demands. Solar concentrator-based energy systems are currently the most efficient methods of using solar energy. Among these technologies, the parabolic trough collector is a mature and effective concentrating solar power technology with a wide range of real-world applications using solar alone or in combination with other energy sources. Flow insert is a potential approach for improving parabolic trough solar collector performance through enhanced heat transfer and heat absorption. The purpose of this study is to determine the feasibility of using a uniform helical wire coil flow insert in the LS-2 parabolic trough solar collector module. A computational fluid dynamic model developed in Ansys 18.1 is used in the current investigation. A uniform helical wire coil flow insert is modeled and compared with the plain tube without any insert inside it. Flow analysis, overall efficiency, exergy efficiency, and thermal efficiency are compared in the evaluation process. The overall efficiency and exergy efficiency of the parabolic trough collector are the most critical criteria in determining its performance. The parabolic trough collector is examined using a range of inlet fluid temperatures ranging from 303 K to 603 K and a volumetric flow rate of 50 L per minute to 250 L per minute. The pumping work is found to be the lowest, indicating that the increase in pressure drop has a negligible effect on the overall system performance. For the flow rate of 50 L per minute and inlet heat transfer fluid temperature of 303 K, the overall, exergy and thermal efficiency using a uniform helical wire coil flow insert are found to be 2.07 %, 2.1 %, and 2.2 %, respectively. © 2024 The Authors
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| 23. |
- Singh, S., et al.
(författare)
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A novel hybrid grey-fuzzy optimization model for assessment of solar technologies considering different scenarios of the Indian market
- 2024
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Ingår i: Energy Reports. - : Elsevier. - 2352-4847. ; 11, s. 2023-2034
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Tidskriftsartikel (refereegranskat)abstract
- This paper examines the various solar photovoltaic technologies available in India. Seven commercially available photovoltaic technologies are compared using thirteen criteria that mainly contribute to sustainability, such as social, economic, and environmental, along with technical criteria under various conditions. Three distinct cases were developed (case I: considering all the thirteen criteria, case II: considering twelve criteria and freezing LCOE criteria, and case III: considering twelve criteria and freezing efficiency criteria) to determine the best technology available for multiple stakeholders to invest in at different conditions. The assessment integrates grey system theory, fuzzy set theory, and multi-criteria decision-making methods. The grey and fuzzy-based Analytical Hierarchy Process is used to determine the significance of the criteria. In contrast, the grey and fuzzy-based COmplex PRoportional ASsessment is used for ranking these technologies. According to the results, the most favorable technology in all three cases is Cadmium Telluride (CdTe) if developed in the Indian zone. The CdTe technology has a lower levelized cost of electricity and module cost, high efficiency, and, most importantly, high technological maturity compared to other technologies. © 2024 The Authors
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| 24. |
- Singh, S., et al.
(författare)
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End of life management of crystalline silicon and cadmium telluride photovoltaic modules utilising life cycle assessment
- 2023
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Ingår i: Resources, Conservation and Recycling. - : Elsevier. - 0921-3449 .- 1879-0658. ; 197
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Tidskriftsartikel (refereegranskat)abstract
- The rapid global adoption of solar photovoltaic (PV) modules created the issue of recycling and disposal at their end of life. Several PV modules installed in the late 1980s or early 1990s have reached the end of their 30-year useful life and are now being removed as PV trash. This enormous amount of PV trash acknowledges recycling as a crucial and significant area in the value chain of PV industries. Hence, this study uses an end-of-life perspective to discuss the life cycle evaluation of two market-dominant PV technologies— c-Si and CdTe. This method examines recycling and avoided burden due to recovered material independently in order to determine the overall environmental benefit. The study concludes that recycling glass, metals like copper and aluminium, and semiconductor material from both c-Si and CdTe PV modules has a lower environmental effect than mining, providing, and refining the same components from original sources. © 2023 The Author(s)
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| 25. |
- Singh, S., et al.
(författare)
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Reduced global warming potential in carbon-based perovskite solar modules : Cradle-to-gate life cycle analysis
- 2023
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Ingår i: Journal of Cleaner Production. - : Elsevier. - 0959-6526 .- 1879-1786. ; 426
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Tidskriftsartikel (refereegranskat)abstract
- Given the superior stability, technologically developed and cost effectiveness of carbon-based perovskite solar cells over conventional metallic electrode-based architectures, this work investigates the environmental performance of two industrial front-runners architectures i.e., high temperature processed carbon-based perovskite solar modules (CPSMs) and low temperature processed CPSMs using cradle-to-gate Life Cycle Assessment analysis assuming a manufacturing plant in India. According to the study, most of the impacts are due to energy consumption in the annealing and screen print paste process used in ETL, perovskite, HTL and cathode layer for both the architectures. Material selection for the perovskite and other layers has a significant environmental impact on both architectures. Compared to low temperature processed architecture, high temperature processed CPSMs have a greater environmental impact. For a five-year lifetime, the global warming potential (GWP) values for high temperature and low temperature processed CPSMs are 0.180 kg CO2-eq and 0.126 kg CO2-eq, respectively, which are marginally higher than those indicated for commercially available silicon solar cells. Thus, a sensitivity analysis was performed to determine the minimum lifetime required to compete with GWP values comparable to commercial PVs. High and low temperature processed CPSM needed 16 and 11 years of lifetime, respectively, to match silicon's 25 years of lifetime. On the other hand, the study finds the human toxicity contribution by mono-silicon is extremely high compared to the two CPSM architectures because of the contribution by electricity (44.01%) and use of heavy metals such as copper (16.83%) and steel (11.52%). © 2023 The Authors
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- Thakur, H., et al.
(författare)
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Investigation of continuous stirred tank reactors for improving the mixing in anaerobic digestion : A numerical study
- 2023
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Ingår i: Results in Engineering (RINENG). - : Elsevier. - 2590-1230. ; 19
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, mechanical impeller mixing has been analyzed through CFD which has proven to be a useful method for simulating mixing before manufacturing the digester. In this work, simulations were done for five different digester designs for TS level of 12.1%. While the fifth digester was cylindrical, the other four were cubical in design with varying impeller diameters and the number of impellers. The power law model was used to resemble the sewage sludge as a non-Newtonian fluid. The modified versions of dead volume and uniformity index were used along with velocity gradient and mixing energy level to quantify the quality of mixing. An analysis of the temperature distributions during mixing and heating was done using a thermal study. The operating speed of 250 rpm was finalized after testing at continuously increasing speeds from 50 to 600 rpm for a flat blade type impeller. As per the thermal model, a 250-W heater raised the temperature by around 15 °C in just 10 min. It was found that cylindrical vessels worked better than cubical digesters and larger impellers also helped in improving the mixing. The cylindrical digester which achieved about 67% homogeneity at a mixing energy level of around 0.95 W/m3, was the optimum design among the investigated digesters. © 2023 The Authors
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