• Book : 455()
• Pub. Date : 2025
• Page : pp.116156
• Keyword :

Abstract

A preliminary approach has been made to assess the concentrated solar energy applications in cement production as well as greenhouse gas mitigation potential. The work starts with identification of processes that utilize thermal energy in cement production. Then, a cluster of cement plants located at different locations in the country has been made. Also, the availability of solar radiation and wind speed at each plant location have been identified. Subsequently, the solar industrial process heating systems have been developed for different locations in the country. Further, solar reactor output, number of heliostats, total land area and mirror surface have been estimated. All these estimations are done by considering three types of thermal losses in solar reactors, i.e., 15, 30 and 45%, respectively. Solar energy can provide a total of 738.11 PJ of thermal energy, which is needed to fulfill the process heating requirement of the calcination process for the manufacturing of cement in India. Solar industrial process heating systems for cement production in India can reduce yearly CO2 emissions by 2457-7648 thousand tons.

• Book : 147(1)
• Pub. Date : 2025
• Page : pp.011009
• Keyword :

Abstract

The physical mechanism, evolution process, and control method on pulsation caused by flow-induced excitation vortex in an axial flow pump are elaborated by numerical calculation and experiment. The mechanism formulation of flow-induced excitation vibration and the unique hydrodynamic design method of airfoil are proposed with three contrast models. According to the action law of inertial centrifugal force in the rotor-stator interaction (RSI) region and guide vane airfoil, the evaluation method between vortex transport, turbulent kinetic energy (TKE) and flow structure under transient and steady-state of internal flow field is established, which navigates the instability of energy intensity determined by the uneven gradient distribution. The distribution characteristics of flow-induced excitation pulsation in the RSI region and the static region are quantitatively verified by experiment. Along the streamwise direction, the excitation loss changes from impact loss to flow loss, with the RSI vortex affected by wake-jet flow vortices transforming into intervane vortex in the guide vane. In pulsation evaluation, the excitation pulsation form changes from blade frequency fBPF to low frequency band. Overall, the generation analysis of the excitation pulsation is realized based on the hydrodynamic optimal design with the comparison of models, which provides guidance for the optimization design of the axial flow pump to reduce vibration and energy consumption of the cooling system.

• Book : 147(1)
• Pub. Date : 2025
• Page : pp.011203
• Keyword :

• Book : 210()
• Pub. Date : 2025
• Page : pp.110858
• Keyword :

• Book : 210()
• Pub. Date : 2025
• Page : pp.110846
• Keyword :

Abstract

The ground ultraviolet (UV) solar radiation is relevant due to its impacts on plastics degradation (mainly UVA) and on human health (UVB and erithemic UV (UVE)). UV ground measurements are not as ubiquitous as the relatively common global horizontal irradiance (GHI) measurements. Three simple models that estimate the UVA, UVB, and UVE components of solar irradiance from GHI and ozone column information are locally adjusted and validated. Five one-minute datasets from three sites in southeastern South America and two in the United States are used for simultaneous solar irradiance and UV data. All sites correspond to temperate mid-latitude regions. Simultaneous atmospheric total ozone column information is obtained from the reanalysis modern-era retrospective analysis for research and applications (MERRA-2) database for each site. Aside from locally adjusted models, average models with a single set of coefficients are also evaluated. For instance, the best average model is able to estimate UVE with a typical uncertainty below 12% and mean biases between ±3%, relative to the average of the measurements. Similar results are reported for the UVB and UVA components. These results, which can be useful in regions with similar climate and geography, provide a simple way to estimate UV irradiance under all-sky conditions with known uncertainty. This is an alternative to global satellite-based UV estimates, which can have high uncertainties at specific locations. Because MERRA-2 information has a global coverage, when coupled with good satellite-based estimates for GHI, UV irradiances can be estimated by this method over a large territory.

• Book : 147(2)
• Pub. Date : 2025
• Page : pp.021001
• Keyword :

• Book : 210()
• Pub. Date : 2025
• Page : pp.110878
• Keyword :

• Book : 210()
• Pub. Date : 2025
• Page : pp.110851
• Keyword :

Abstract

Subchannel analysis codes are presently a requirement for design and safety analysis of nuclear reactors. Among the crucial inputs for these codes, the turbulent mixing factor holds particular significance. However, acquiring this factor through experimental means proves to be a challenging endeavor, primarily due to the necessity for precise pressure equilibrium between subchannels. Consequently, this requirement leads to the undertaking of expensive and intricate experiments for each new reactor or in cases where there are modifications in fuel bundle design. The need for direct numerical simulation (DNS) stems from the challenges and costs involved in experimental techniques, and the uncertainties due to empiricism in computational fluid dynamics (CFD) models. In this study, DNS has been conducted across six Reynolds numbers, ranging from 17,640 to 1.176 × 105, in the geometry of a pressurized water reactor (PWR) subchannel. The resulting turbulent flow structures have been computed and their dynamics are examined. Furthermore, this paper presents a methodology for directly calculating the turbulent mixing factor from the fluctuating velocity field obtained from DNS data. The turbulent mixing process has been scrutinized in-depth, and a correlation for the turbulent mixing factor is developed. It is noted that most of the mixing occurs in the near-wall region. The study suggests different mixing factors for mass and momentum mixing. This paper aims to provide a comprehensive insight into the turbulent mixing phenomenon.

• Book : 11(2)
• Pub. Date : 2025
• Page : pp.021001
• Keyword :

Abstract

Purpose

Concurrent chemoradiation has been the mainstay of treatment for cervix cancer. We aimed to evaluate the non-inferiority of hypofractionated chemoradiation.

Methods

This study was designed as a phase 2, 1:1 randomized, investigator-blinded, controlled, non-inferiority trial and we report the interim results after 50% accrual. Cervical cancer patients with FIGO stages IIA-IIIC were recruited from April 2021 to September 2022. The intervention consisted of 40 Gy of 3D-conformal radiation therapy (RT) in 15 fractions over 3 weeks. In the control group, patients received standard chemoradiation of 45 Gy in 25 fractions over 5 weeks. Both groups received concurrent weekly cisplatin (40 mg/m²). Intravaginal brachytherapy of 28 Gy in 4 weekly fractions was delivered starting 1 week after the end of chemoradiation. The primary outcome was complete clinical response(CCR) at 3 months. Secondary outcomes included acute gastrointestinal (GI), genitourinary(GU), skin, and hematologic toxicities. A p value less than 0.05 was considered significant for analyses.

Results

59 patients were randomized; 30 in the control group and 29 in the intervention group. 20/30 (66.7%) of the patients in the control group and 19/29 (65.5%) in the intervention group achieved a CCR (absolute difference of 0.011, 95% CI − 0.23 to 0.25, p value: 0.13). There was a significantly higher rate of acute grade ≥ 3 GI toxicity in the intervention group (27.6%) compared with the control group (6.7%) (p value 0.032).

Conclusions

Despite an absolute difference of 1.1% in the 3-month CCR, our interim analysis failed to show the non-inferiority of the hypofractionated chemoradiation. Due to the higher GI toxicities, we will continue this trial using intensity-modulated radiation therapy.

Registration number and date

ClinicalTrials.gov: NCT04831437, 2021.4.1.

• Book : 150(1)
• Pub. Date : 2025
• Page : pp.20
• Keyword :