Spherical Geometry of Hilbert Schemes of Conics in Adjoint Varieties

For each adjoint variety not of type $A$ or $C$, we study the irreducible component of the Hilbert scheme which parametrizes all smooth conics. We prove that its normalization is a spherical variety by using contact geometry, and then compute the colored fan of the normalization. As a corollary, we describe the conjugacy classes of conics in the adjoint variety and show smoothness of the normalization. Similar results on the Chow scheme of the adjoint variety are also presented.Comment: 42 pages, comments are welcom

Morphology of Galaxies in JWST Fields: Initial Distribution and Evolution of Galaxy Morphology

A recent study from the Horizon Run (HR5) cosmological simulation has predicted that galaxies with ${\rm log}~M_{\ast}/M_{\odot}\lesssim 10$ in the cosmic morning ($10\gtrsim z\gtrsim 4$) dominantly have disk-like morphology in the $\Lambda$CDM universe, which is driven by the tidal torque in the initial matter fluctuations. For a direct comparison with observation, we identify a total of about $19,000$ James Webb Space Telescope (JWST) galaxies with ${\rm log}~M_{\ast}/M_{\odot}>9$ at $z=0.6-8.0$ utilizing deep JWST/NIRCam images of publicly released fields, including NEP-TDF, NGDEEP, CEERS, COSMOS, UDS, and SMACS J0723$-$7327. We estimate their stellar masses and photometric redshifts with the redshift dispersion of $\sigma_{\rm NMAD}=0.009$ and outlier fraction of only about $6\%$. We classify galaxies into three morphological types, `disks', `spheroids', and `irregulars', applying the same criteria used in the HR5 study. The morphological distribution of the JWST galaxies shows that disk galaxies account for $60-70\%$ at all redshift ranges. However, in the high-mass regime (${\rm log}~M_{\ast}/M_{\odot}\gtrsim11$), spheroidal morphology becomes the dominant type. This implies that mass growth of galaxies is accompanied with morphological transition from disks to spheroids. The fraction of irregulars is about 20\% or less at all mass and redshifts. All the trends in the morphology distribution are consistently found in the six JWST fields. These results are in close agreement with the results from the HR5 simulation, particularly confirming the prevalence of disk galaxies at small masses in the cosmic morning and noon.Comment: Accepted for publication in ApJ, 30 pages, 14 figures, 5 tables, 3 appendice

Interpolation time-optimized aortic pulse wave velocity estimation by 4D flow MRI

Abstract Four-dimensional flow magnetic resonance imaging-based pulse wave velocity (4D flow PWV) estimation is a promising tool for measuring regional aortic stiffness for non-invasive cardiovascular disease screening. However, the effect of variations in the shape of flow waveforms on 4D flow PWV measurements remains unclear. In this study, 4D flow PWV values were compared using cross-correlation algorithm with different interpolation times (iTs) based on flow rate and beat frequency. A critical iT (iTCrit) was proposed from in vitro study using flexible and stiff phantom models to simultaneously achieve a low difference and a low computation time. In vivo 4D flow PWV values from six healthy volunteers were also compared between iTCrit and the conventionally used interpolation time of 1 ms (iT1 ms). The results indicated that iTCrit reduced the mean difference of in vitro 4D flow PWV values by 19%, compared to iT1 ms. In addition, iTCrit measured in vivo 4D flow PWV, showing differences similar to those obtained with iT1 ms. A difference estimation model was proposed to retrospectively estimate potential differences of 4D flow PWV using known values of PWV and the used iT. This study would be helpful for understanding the differences of PWV generated by physiological changes and time step of obtained flow waveforms

Cooling Performance Prediction for Hydraulic Thermoelectric Radiant Cooling Panels with Experimental Validation

Thermoelectric technology has been developed as a substitute for existing refrigerants in heating, ventilation, and air-conditioning system applications for building decarbonization. A hydraulic thermoelectric radiant cooling panel (hTERCP) operated based on the Peltier effect can alternate a conventional cooling system using a chiller with refrigerators. This study aimed to develop a cooling performance prediction model for a hTERCP-integrated free cooling system according to the desirable range of five design factors. A mockup model of the hTERCP was constructed and tested in an environmental chamber to verify the proposed simulation model. The simulation and the experimental analysis confirmed that the heat rejection performance of the thermoelectric module (TEM) significantly affects the cooling performance of the hTERCP. The cooling water temperature was the primary design factor for releasing heat from the hot side of the TEM and significantly influenced the cooling performance of the hTERCP. A parametric analysis of the five design factors was conducted to investigate a method for improving the coefficient of performance (COP) of the hTERCP. The cooling water temperature affected the COP by 38.6–45.7%, and the heat exchange area of the cooling surface greatly influenced the cooling performance by 41.4%. The cooling water flow rate, heat exchange effectiveness of the water block, and heat resistance of the hot side were confirmed to have relatively little influence as 9.7–10.2%, 11.9–24.8%, and 0.7–11.1%, respectively

Cooling Performance Prediction for Hydraulic Thermoelectric Radiant Cooling Panels with Experimental Validation

Thermoelectric technology has been developed as a substitute for existing refrigerants in heating, ventilation, and air-conditioning system applications for building decarbonization. A hydraulic thermoelectric radiant cooling panel (hTERCP) operated based on the Peltier effect can alternate a conventional cooling system using a chiller with refrigerators. This study aimed to develop a cooling performance prediction model for a hTERCP-integrated free cooling system according to the desirable range of five design factors. A mockup model of the hTERCP was constructed and tested in an environmental chamber to verify the proposed simulation model. The simulation and the experimental analysis confirmed that the heat rejection performance of the thermoelectric module (TEM) significantly affects the cooling performance of the hTERCP. The cooling water temperature was the primary design factor for releasing heat from the hot side of the TEM and significantly influenced the cooling performance of the hTERCP. A parametric analysis of the five design factors was conducted to investigate a method for improving the coefficient of performance (COP) of the hTERCP. The cooling water temperature affected the COP by 38.6–45.7%, and the heat exchange area of the cooling surface greatly influenced the cooling performance by 41.4%. The cooling water flow rate, heat exchange effectiveness of the water block, and heat resistance of the hot side were confirmed to have relatively little influence as 9.7–10.2%, 11.9–24.8%, and 0.7–11.1%, respectively

Morphology of Galaxies in JWST Fields: Initial Distribution and Evolution of Galaxy Morphology

A recent study from the Horizon Run 5 (HR5) cosmological simulation has predicted that galaxies with $\mathrm{log}\,{M}_{* }/{M}_{\odot }\lesssim 10$ in the cosmic morning (10 ≳ z ≳ 4) dominantly have disk-like morphology in the ΛCDM universe, which is driven by the tidal torque in the initial fluctuations of matter. For a direct comparison with observation we identify a total of about 19,000 James Webb Space Telescope (JWST) galaxies with $\mathrm{log}\,{M}_{* }/{M}_{\odot }\gt 9$ at z = 0.6–8.0 utilizing deep JWST/NIRCam images of publicly released fields, including North Ecliptic Pole Time-Domain Fields, Next Generation Deep Extragalactic Exploratory Public survey, Cosmic Evolution Early Release Science Survey, Cosmic Evolution Survey, UltraDeep Survey, and SMACS J0723-7327. We estimate their stellar masses and photometric redshifts with the redshift dispersion of σ _NMAD = 0.009 and an outlier fraction of only about 6%. We classify galaxies into three morphological types, disks, spheroids , and irregulars , applying the same criteria used in the HR5 study. The morphological distribution of the JWST galaxies shows that disk galaxies account for 60%–70% at all redshift ranges. However, in the high-mass regime ( $\mathrm{log}\,{M}_{* }/{M}_{\odot }\gtrsim 11$ ), spheroidal morphology becomes the dominant type. This implies that the mass growth of galaxies is accompanied by a morphological transition from disks to spheroids. The fraction of irregulars is about 20% or less at all masses and redshifts. All the trends in the morphology distribution are consistently found in the six JWST fields. These results are in close agreement with the results from the HR5 simulation, particularly confirming the prevalence of disk galaxies at small masses in the cosmic morning and noon

The effects of individual and organizational interventions on space tourism : applying EMGB and fsQCA

There is limited theoretically informed research on sustainability in the space tourism market. An extended model of goal-directed behaviour (EMGB) is created and verified with individual and organizational interventions, comparing space tourism experienced and non-experienced travellers. Results revealed that individual intervention has fully significant effects on all MGB constructs, while organizational intervention has partially significant impacts, which in turn influence desire relevant to behavioural intention. The findings from fsQCA showed the different profiles of experienced and non-experienced tourists

Aluminum textile-based binder-free nanostructured battery cathodes using a layer-by-layer assembly of metal/metal oxide nanoparticles

Despite considerable interest in textile-based battery electrodes with large surface areas and mechanical flexibility, issues have restricted further advances in the energy performance of textile electrodes. These issues include the ineffective incorporation of conductive and/or active components into textile frameworks, the poor charge transfer between energy materials, and the formation of numerous unstable interfaces within textile electrodes. Herein, we introduce an aluminum textile-based lithium-ion battery cathode with remarkable areal capacity, high rate performance, and good cycling stability. Ligand exchange reaction-induced layer-by-layer (LbL) assembly of metal nanoparticles and small molecule linkers, with subsequent metal electroplating, perfectly converted polyester textiles to 3D-porous aluminum textiles that can be used as current collectors and high-energy reservoirs. The consecutive LbL assembly of high-energy LiFePO4 and conductive indium tin oxide nanoparticles onto the aluminum textiles using small organic linkers significantly increased the areal capacity and cycling stability (at least 580 cycles) of the resultant cathode, allowing facile charge transfer within the textile electrodes. Furthermore, the areal capacity of these textile electrodes increased from 1.07 to 3.28 mA h cm-2, with an increase in the folding number from 0 to 2. © 2021 Author(s).1

Numerical Analysis of a TEG and mPCM Enhancement System for BIPVs Using CFD

Building-integrated photovoltaics (BIPVs) are the most promising systems for net-zero energy buildings. However, there are few practical cases because of shortcomings, such as the lack of solar tracking and the rapid rise in PV surface temperature. Therefore, methods of increasing the efficiency of BIPVs have been proposed and studied. These include using phase change material (PCM) or heat fins, wavelength selection, decreasing the PV surface temperature, or using a thermoelectric generator (TEG) and convection cooling to utilize the waste heat from the PV. Many preceding studies have been conducted on TEG and convection heat dissipation methods to utilize as much waste heat as possible. Therefore, in this study, a TEG–PCM hybrid system using mPCM was proposed to improve constructability. Herein, the appropriate phase change temperature of the PCM, the heat fin spacing in the PCM container, and the TEG arrangement were analyzed through computational fluid dynamics (CFD)-based simulations. The appropriate melting temperature of the PCM, the heat fin interval, and the arrangement of the TEG for the proposed system are 25 °C, 20 mm, and 140 mm, respectively. In order to achieve optimal efficiency, it is necessary to consider an appropriate amount of heat transfer, and it has been confirmed that if there are too many thermoelectric elements, the opposite effect occurs