Significance of Parameters Affecting the Performance of a Passive Down-Draft Evaporative Cooling (PDEC) Tower with a Spray System

PDEC towers with spray systems are known to achieve substantial energy savings. Various parameters such as the wet-bulb depression, the tower height, and the wind speed have been known to be key factors affecting the performance of the system. To date, the significance of these parameters and other important factors have not been adequately treated in the literature. There also has been a lack of models that can successfully investigate potential benefits of the system under various conditions where this particular system could be applicable. To address these critical issues, this study performed a parametric analysis by using a FLUENT model validated against experimental data. It demonstrated the significance of individual parameters including water droplet sizes. As a result, practical design guidelines for important system parameters were presented. A statistical analysis was then used to formulate analytic models that account for all of the relationships found in this study between the parameters and the supply air conditions of the system. Two regression equations were formulated for predicting supply air temperature and velocity

Competence of a Spray Passive Down-draft Evaporative Cooling (PDEC) System for Space Cooling

A spray PDEC system has been relatively less considered than other passive cooling strategies as one of the viable low-energy solutions in the cooling of buildings while having a great potential in energy savings. This study is intended to evaluate the capability of a spray PDEC system for space cooling. It comprises four simulation scenarios to see the system response and influence of indoor thermal environment when a spray PDEC system is adopted as a primary cooling system in two different climates. The simulation results show that a spray PDEC system causes a substantial variation in the indoor thermal environment and sensible cooling rates while substantiating significant energy savings

Analysis of the system response of a spray passive downdraft evaporative cooling system

A spray Passive Downdraft Evaporative Cooling (PDEC) system achieves great savings for space cooling and improves indoor environmental quality by supplying a large amount of fresh outdoor air. As previous studies heavily focused on the energy saving capability of a spray PDEC system due to lack of methods for a detailed analysis, the influence of cool humid supply air from a spray PDEC system in a space in buildings has not been comprehensively studied. This study is intended to evaluate the competence of a spray PDEC system as a primary cooling system in typical spaces in a primary school building by developing a method using building energy simulation tool. It runs one-day simulations in a hot dry climate and a warm moderate climate in order to distinctly examine the benefits and the areas that should be advanced. It analyses how a spray PDEC system responds to the space cooling loads and spaces conditioned by the system thermally behave. The results of the simulations affirm that a spray PDEC system is capable of conditioning building spaces in the two climates, indicating some areas to be improved

Performance Control of a Spray Passive Down-Draft Evaporative Cooling System

A spray passive down-draft evaporative cooling system has been regarded as a low-energy cooling system that leads significant energy savings in the cooling of buildings. While the energy saving capability of the system has been proven, the ability to control a comfortable indoor environment is still inadequate due to strong climatic dependency. This study seeks viable solutions to advance the control competence of the system by mitigating critical problems of the system to be a reliable cooling application in the cooling of buildings. It proposes potential control strategies for the system and alternative operations. It develops a control algorithm for the proposed control strategies and implements the algorithm in EnergyPlus. A simulation analysis follows to examine the functionality of each proposed control strategy and alternative operations. The results of the simulations ascertain that a spray PDEC system with a water flow control performs better. In addition, a spray PDEC system contributes most when it operates as a secondary cooling system to abate space cooling loads and to maintain a steady thermal environment by reducing 62.1% electricity for space cooling and 47.9% water consumption in a warm-moderate climate

Ubiquitination and degradation of SUMO1 by small-molecule degraders extends survival of mice with patient-derived tumors

Discovery of small-molecule degraders that activate ubiquitin ligase–mediated ubiquitination and degradation of targeted oncoproteins in cancer cells has been an elusive therapeutic strategy. Here, we report a cancer cell–based drug screen of the NCI drug-like compounds library that enabled identification of small-molecule degraders of the small ubiquitin-related modifier 1 (SUMO1). Structure-activity relationship studies of analogs of the hit compound CPD1 led to identification of a lead compound HB007 with improved properties and anticancer potency in vitro and in vivo. A genome-scale CRISPR-Cas9 knockout screen identified the substrate receptor F-box protein 42 (FBXO42) of cullin 1 (CUL1) E3 ubiquitin ligase as required for HB007 activity. Using HB007 pull-down proteomics assays, we pinpointed HB007’s binding protein as the cytoplasmic activation/proliferation-associated protein 1 (CAPRIN1). Biolayer interferometry and compound competitive immunoblot assays confirmed the selectivity of HB007’s binding to CAPRIN1. When bound to CAPRIN1, HB007 induced the interaction of CAPRIN1 with FBXO42. FBXO42 then recruited SUMO1 to the CAPRIN1-CUL1-FBXO42 ubiquitin ligase complex, where SUMO1 was ubiquitinated in several of human cancer cells. HB007 selectively degraded SUMO1 in patient tumor–derived xenografts implanted into mice. Systemic administration of HB007 inhibited the progression of patient-derived brain, breast, colon, and lung cancers in mice and increased survival of the animals. This cancer cell–based screening approach enabled discovery of a small-molecule degrader of SUMO1 and may be useful for identifying other small-molecule degraders of oncoproteins

Non-vacuum, single-step conductive transparent ZnO patterning by ultra-short pulsed laser annealing of solution-deposited nanoparticles

A solution-processable, high-concentration transparent ZnO nanoparticle (NP) solution was successfully synthesized in a new process. A highly transparent ZnO thin film was fabricated by spin coating without vacuum deposition. Subsequent ultra-short-pulsed laser annealing at room temperature was performed to change the film properties without using a blanket high temperature heating process. Although the as-deposited NP thin film was not electrically conductive, laser annealing imparted a large conductivity increase and furthermore enabled selective annealing to write conductive patterns directly on the NP thin film without a photolithographic process. Conductivity enhancement could be obtained by altering the laser annealing parameters. Parametric studies including the sheet resistance and optical transmittance of the annealed ZnO NP thin film were conducted for various laser powers, scanning speeds and background gas conditions. The lowest resistivity from laser-annealed ZnO thin film was about 4.75 x 10(-2) Omega cm, exhibiting a factor of 10(5) higher conductivity than the previously reported furnace-annealed ZnO NP film and is even comparable to that of vacuum-deposited, impurity-doped ZnO films within a factor of 10. The process developed in this work was applied to the fabrication of a thin film transistor (TFT) device that showed enhanced performance compared with furnace-annealed devices. A ZnO TFT performance test revealed that by just changing the laser parameters, the solution-deposited ZnO thin film can also perform as a semiconductor, demonstrating that laser annealing offers tunability of ZnO thin film properties for both transparent conductors and semiconductors.N

Fiber laser annealing of indium-tin-oxide nanoparticles for large area transparent conductive layers and optical film characterization

Indium tin oxide (ITO) coatings are widely used as transparent electrodes for optoelectronic devices. The most common preparation methods are sputtering, evaporation, and wet chemical deposition. ITO coatings can also be manufactured by solution deposition of ITO nanoparticles followed by furnace thermal annealing with the major motivation to reduce equipment investment. However, conventional furnace annealing is energy intensive, slow, and limited by the peak processing temperature. To overcome these constraints, we suggest using a laser beam for ITO nanoparticle annealing over a large area. It is shown in the present study that a low cost, high power, and high efficiency laser can yield large area functional ITO films in a process that carries substantial promise for potential industrial implementation. Furthermore, laser annealing generates higher electrical conductivity than conventional, thermally annealed nanoparticle films. The optical and electrical properties of the annealed ITO films can also be altered by adjusting laser parameters and environmental gases.N

Electrochemical Performance of Chemically and Solid State-Derived Chevrel Phase Mo₆T₈ (T = S, Se) Positive Electrodes for Sodium-Ion Batteries

Chevrel phases, or CPs (Mo₆T₈; T = S, Se), can accommodate cations (Li⁺, Mg²⁺ etc.) within the Mo₆T₈ open framework at room temperature due to their unusually high electronic conductivity and ionic mobility and are hence proposed as positive electrodes for secondary batteries. However, cation insertion into Mo₆T₈ generates strong repulsion between the cation–cation or cation–Mo atoms, leading to partial charge trapping within the Mo₆T₈ structure. The present work examines CPs as positive electrodes for sodium-ion batteries. In this regard, ternary CPs of Cu_<i>x</i>Mo₆S₈ and Cu_<i>x</i>Mo₆Se₈ phase were prepared by solution chemistry and high energy mechanical milling (HEMM) routes, respectively, followed by acid leaching of copper. X-ray diffraction and scanning electron micrographs revealed the formation of 1–1.5 μm size cuboidal Cu_1.8Mo₆S₈ particles, whereas, HEMM of CuSe, MoSe₂ and Mo powder followed by heating leads to the formation of Cu₂Mo₆Se₈ phase. Results from cyclic voltammetry and galvanostatic cycling of Na/Mo₆S₈ and Na/Mo₆Se₈ cells within 1.2–2.2 V versus sodium revealed that two-step sodiation/desodiation reaction occurs with a gradual capacity fade due to Na-ion trapping within two terminal compositions, Na_<i>x</i>Mo₆T₈ (T = S, Se; <i>x</i> ∼ 1 and 3). Electrochemical impedance spectroscopy at ∼0.1 V intervals during the sodiation/desodiation process illustrates that partial Na-ion trapping resulted in an increase in charge transfer resistance, <i>R</i>_e, due to the formation of stable Na_∼1Mo₆S₈ phase after the first charge cycle. However, charge trapping continues to occur during the first and second cycles in the case of Mo₆Se₈ phase. Nevertheless, the ease of fabrication, stable capacity, and high Coulombic efficiency render Mo₆T₈ (T = S, Se) as promising Na-ion positive electrodes for stationary electrical energy storage (EES) applications