Investigation on the thermal-hydraulic performance in a PCHE with airfoil fins for supercritical LNG near the pseudo-critical temperature under the rolling condition

In this study, thermal and hydraulic performance of supercritical liquefied natural gas (LNG) is numerically studied in a printed circuit heat exchanger (PCHE) with airfoil fins under a rolling condition. Effects of operating pressures and rolling parameters are investigated. Results indicate that the PCHE has better thermal performance but worse hydraulic performance at a lower pressure condition. The instantaneous Nusselt numbers and the instantaneous Darcy friction factors present quasi-sine patterns against time, with a period same as the rolling period. The rolling condition gives larger time-averaged Nusselt numbers and Darcy friction factors, compared with the static condition, and the thermal and hydraulic performance increases with increasing rolling amplitude and rolling frequency. However, the rolling amplitude has a prevailing effect on the performance, in comparison to the rolling frequency

Parametric study and optimization on heat transfer and flow characteristics in a rectangular channel with longitudinal vortex generators

In this study, effects of various geometrical parameters of a new winglet longitudinal vortex generator (LVG) on heat transfer and flow characteristics in a rectangular channel were investigated by a numerical method, and the influence of various parameters was analyzed. A comparative study of effects of elliptical pole parameters, the thickness, the length, the height, the attack angle, the transverse pitch and the longitudinal pitch of LVGs on heat transfer and pressure loss performance was conducted. The results showed that the intensity of heat transfer could be greatly increased by the increase of the length, the height, the attack angle and the transverse pitch of LVGs, accompanied with an increase of pressure drop. The Nusselt number decreased by increasing the longitudinal pitch of LVGs. The short axis and major axis of the elliptical poles and the thickness of LVGs had a small influence on the average heat transfer coefficient and average friction factor at the present condition. The design parameters of this configuration were optimized by the Taguchi method. Sixteen kinds of models were made by compounding levels on each factor, and heat transfer and flow characteristics of each model were analyzed. The results allowed us to quantitatively estimate the various parameters affecting heat transfer performance, and the main factors for optimal design of a rectangular channel with LVGs were selected. The optimal condition was also acquired by two analytical results

Air inlet angle influence on the air-side heat transfer and flow friction characteristics of a finned oval tube heat exchanger

In this study, the influence of various air inlet angles on the heat transfer and flow friction characteristics of a 2-row plain finned oval tube heat exchanger is analyzed by experimental and numerical methods. The experimental results show that an air inlet angle 45° provides the best heat transfer performance, and an air inlet angle 90° provides the smallest pressure drop, while an air inlet angle 30° provides the worst heat transfer performance associated with the largest pressure drop. The 3-D numerical simulation results indicate that with the decrease of the air inlet angle, the uniformity of the air velocity distribution in the z-direction of the heat exchanger becomes worse. The heat transfer characteristics at different air inlet angles are analyzed from the prospective of the field synergy principle and the effect of the air velocity distribution uniformity. The overall heat transfer performance is also evaluated by the JF factor under the same air mass flow rate. The results show that the air inlet angle 45° offers the best overall heat transfer performance, next is the air inlet angle 60°, while the air inlet angle 30° has the worst overall heat transfer performance

Augmented GBM Nonlinear Model to Address Spectral Variability for Hyperspectral Unmixing

Spectral unmixing (SU) is a significant preprocessing task for handling hyperspectral images (HSI), but its process is affected by nonlinearity and spectral variability (SV). Currently, SV is considered within the framework of linear mixing models (LMM), which ignores the nonlinear effects in the scene. To address that issue, we consider the effects of SV on SU while investigating the nonlinear effects of hyperspectral images. Furthermore, an augmented generalized bilinear model is proposed to address spectral variability (abbreviated AGBM-SV). First, AGBM-SV adopts a generalized bilinear model (GBM) as the basic framework to address the nonlinear effects caused by second-order scattering. Secondly, scaling factors and spectral variability dictionaries are introduced to model the variability issues caused by the illumination conditions, material intrinsic variability, and other environmental factors. Then, a data-driven learning strategy is employed to set sparse and orthogonal bases for the abundance and spectral variability dictionaries according to the distribution characteristics of real materials. Finally, the alternating direction method of multipliers (ADMM) optimization method is used to split and solve the objective function, enabling the AGBM-SV algorithm to estimate the abundance and learn the spectral variability dictionary more effectively. The experimental results demonstrate the comparative superiority of the AGBM-SV method in both qualitative and quantitative perspectives, which can effectively solve the problem of spectral variability in nonlinear mixing scenes and to improve unmixing accuracy

Mechanisms of PANoptosis and relevant small-molecule compounds for fighting diseases

Abstract Pyroptosis, apoptosis, and necroptosis are mainly programmed cell death (PCD) pathways for host defense and homeostasis. PANoptosis is a newly distinct inflammatory PCD pathway that is uniquely regulated by multifaceted PANoptosome complexes and highlights significant crosstalk and coordination among pyroptosis (P), apoptosis (A), and/or necroptosis(N). Although some studies have focused on the possible role of PANpoptosis in diseases, the pathogenesis of PANoptosis is complex and underestimated. Furthermore, the progress of PANoptosis and related agonists or inhibitors in disorders has not yet been thoroughly discussed. In this perspective, we provide perspectives on PANoptosome and PANoptosis in the context of diverse pathological conditions and human diseases. The treatment targeting on PANoptosis is also summarized. In conclusion, PANoptosis is involved in plenty of disorders including but not limited to microbial infections, cancers, acute lung injury/acute respiratory distress syndrome (ALI/ARDS), ischemia-reperfusion, and organic failure. PANoptosis seems to be a double-edged sword in diverse conditions, as PANoptosis induces a negative impact on treatment and prognosis in disorders like COVID-19 and ALI/ARDS, while PANoptosis provides host protection from HSV1 or Francisella novicida infection, and kills cancer cells and suppresses tumor growth in colorectal cancer, adrenocortical carcinoma, and other cancers. Compounds and endogenous molecules focused on PANoptosis are promising therapeutic strategies, which can act on PANoptosomes-associated members to regulate PANoptosis. More researches on PANoptosis are needed to better understand the pathology of human conditions and develop better treatment

Remote Sensing Detection of Vegetation and Landform Damages by Coal Mining on the Tibetan Plateau

In order to satisfy the needs of constant economic growth, the pressure to exploit natural resources has been increasing rapidly in China. Particularly with the implementation of the National Western Development Strategies since 1999, more and more mining activities and related infrastructure constructions have been conducted on the Tibetan Plateau (TP). Mining activities are known to have substantial impacts on plant dynamics and hence the water and energy cycles. Identifying mining activities and quantifying their effects on vegetation cover are critical to the monitoring and protection of the pristine TP environment. Thus, this study aims to develop an automated approach that detects the timing of initial mining development and assess the spatial distribution of mining-ruined vegetation. The Breaks for Additive Seasonal and Trend (BFAST) algorithm was used to decompose the signal in the normalized difference vegetation index (NDVI) time series derived from high-frequency MODIS images, and to detect abrupt changes of surface vegetation. Results show that the BFAST algorithm is able to effectively identify abrupt changes in vegetation cover as a result of open-mining development on the studied alpine grassland. The testing study in Muli Town of Qinghai Province shows that the mining development began in 2003 and massive destructions of vegetation cover followed between 2008 and 2012. The integrated use of Landsat imagery and multi-temporal DEMs further reveals detailed areal and volumetric changes in the mining site. This study demonstrates the potential of applying multi-mission satellite datasets to assess large-scale environmental influences from mining development, and will be beneficial to environmental conservation and sustainable use of natural resources in remote regions

Publisher Correction: Dietary arginine affects the insulin signaling pathway, glucose metabolism and lipogenesis in juvenile blunt snout bream Megalobrama amblycephala

A correction to this article has been published and is linked from the HTML version of this paper. The error has been fixed in the paper