In this paper, two desiccant-coated heat exchangers, which are actually fin-tube heat exchanging devices coated with silica gel and polymer materials respectively, are investigated experimentally. ...Due to the hygroscopic properties of the desiccant materials, both the sensible heat and the latent heat of the process air can be handled by using this kind of heat exchanger. An experimental setup was designed and built to test the performance of this unit. It is found that this desiccant-coated fin-tube heat exchanger well overcomes the side effect of adsorption heat which occurs in desiccant dehumidification process, and achieves good dehumidification performance under given conditions. The silica gel coated heat exchanger behaves better than the polymer one. The influences of regeneration temperature, inlet air temperature and humidity on the system performance in terms of average moisture removal rate
D
avg and thermal coefficient of performance COP
th were also analyzed.
Based upon the fast development of energy efficiency, energy safety and use of renewable and sustainable energy, various energy systems related to residential refrigeration, power generation and ...storage have been developing. Some of them are in large scale application, while others are still under development. Current status of residential refrigeration, power generation and energy storage technologies have been briefly summarized in this paper. Also, future residential refrigeration, power generation and energy storage technologies are highlighted, and some roadmaps are discussed.
▸ Current status and future development of residential refrigeration have been briefly summarized and discussed. ▸ Current status and future development of power generation have been briefly summarized and discussed. ▸ Current status and future development of energy storage have been briefly summarized and discussed.
A mathematical model for predicting the performance of novel silica gel haloid compound desiccant wheel is established. Both the gas side resistance and the solid side resistance are considered in ...the model. It is found that the results of this model agree better to the experiments than the results of a former model which does not take the solid side resistance into account at all. Then the model is adopted to analyze the effects of some main parameters on system performance. It is found that the compound desiccant wheel has a better performance in a climate with moderate temperature or in a climate with high humidity ratio. Then under the basic conditions for the simulations (ambient air is of 35
°C, 15
g/kg and wheel thickness of 100
mm), an angle of the regeneration section between 100° and 160°, a regeneration temperature between 80
°C and 95
°C, a flow rate of process air between 2.0
m/s and 3.5
m/s and that of regeneration air between 2.5
m/s and 3.5
m/s are recommended. Also, there exists an optimal rotation speed to achieve the maximal moisture removal, which is about 12
r/h. At last, the influences of the main parameters on optimal rotation speed are discussed.
In this paper, an experimental setup of a desiccant dehumidification unit silica gel coated fin-tube heat exchanger is installed and investigated. In this unit, two silica gel coated heat exchangers ...(SCHE) are adopted and switched to provide continuous dehumidification capacity. Meanwhile, hot water from vacuum tube solar collector is used to regenerate silica gel. System performance is evaluated in terms of moisture removal mass and thermal COP. Influences of major parameters on system performance are tested and analyzed under Shanghai summer conditions. It is found that system performance is affected significantly by cycle time between dehumidification and regeneration, and optimal cycle time is 600 s under test conditions. For actual system, the unit can be independently used as dehumidifier with 100% fresh air under mild conditions. But when the outside humidity is too large, it can be used in combination with primary return air-conditioning to provide satisfied supply air.
•We first introduce a novel desiccant dehumidification unit.•Experiments are conducted to evaluate performance of the unit under summer conditions.•The variation rules of the unit under different conditions have been summarized and discussed.
In this paper, we present a systematic approach for fuel-economy optimization of a connected automated truck that utilizes motion information from multiple vehicles ahead via vehicle-to-vehicle (V2V) ...communication. Position and velocity data collected from a chain of human-driven vehicles are utilized to design a connected cruise controller that smoothly responds to traffic perturbations while maximizing energy efficiency. The proposed design is evaluated using a high-fidelity truck model and the robustness of the design is validated on real traffic data sets. It is shown that optimally utilizing V2V connectivity leads to around 10% fuel economy improvements compared to the best nonconnected design.
Desiccant coated heat exchangers (DCHEs), utilizing an inner cooling source to remove sorption heat, are promising alternatives for evaporators and condensers (DCEs/DCCs) in vapor compression (VC) ...heat pumps. A mathematical model is necessary to facilitate the design, analysis and performance prediction of the component and the relevant systems. In this study, a three-dimensional model of DCEs/DCCs is proposed, accounting for the two-phase phenomena, the periodical switchover, the solid-side resistance, the fluid transport in multiple directions and the coupled heat and mass transfer. Study reveals that, high latent load (inlet humidity) reduces the sensible heat handling capacity of the DCEs, while the dehumidification capacity is almost independent of its sensible heat load. DCEs possess a satisfying effect of dehumidification above the dew point, thus it is unnecessary to employ low evaporation temperature. Meanwhile, the adsorption-desorption temperature difference of 30 °C seems to be the optimal value for the commonly adopted evaporation temperatures (10 °C-20 °C). For a specific coating thickness, there is a critical switchover period where the best performance of dehumidification is obtained. Switchover period shorter than the critical time should be avoided, and elongating the switchover cycle helps balance the ability of the system to handle the sensible and latent heat loads at the same time.
The substitution of Zn in hydroxyapatite (HA) crystals was examined via comprehensive characterization techniques. Nanosized HA crystals were synthesized by the wet chemical method in aqueous ...solutions including various amounts of Zn ions. X-ray fluorescent spectroscopy was used to examine the amount of Zn in the HA precipitates. Scanning electron microscopy and high-resolution transmission electron microscopy were employed to examine the effects of Zn on the morphology and crystal size of the precipitates. Conventional powder X-ray diffraction and the Rietveld refinement method revealed the apatite lattice parameters and phase changes with the inclusion of Zn. The results indicated that Zn ions partially substituted for Ca ions in the apatite structure. They were not simply adsorbed on the apatite surface or in the amorphous phase. The precipitates maintained the apatite phase up to a Zn:(Zn
+
Ca) ratio of 15–20
mol.% in the solution. Pure HA was well crystallized and the crystals had regular shapes, whereas the Zn-substituted apatite crystals became irregular and formed agglomerates. The lattice parameters,
a and
c, decreased at a Zn:(Zn
+
Ca) ratio of 10
mol.%.
Memristors with tunable resistance states are emerging building blocks of artificial neural networks. However, in situ learning on a large-scale multiple-layer memristor network has yet to be ...demonstrated because of challenges in device property engineering and circuit integration. Here we monolithically integrate hafnium oxide-based memristors with a foundry-made transistor array into a multiple-layer neural network. We experimentally demonstrate in situ learning capability and achieve competitive classification accuracy on a standard machine learning dataset, which further confirms that the training algorithm allows the network to adapt to hardware imperfections. Our simulation using the experimental parameters suggests that a larger network would further increase the classification accuracy. The memristor neural network is a promising hardware platform for artificial intelligence with high speed-energy efficiency.
Despite the remarkable success of immunotherapy in many types of cancer, pancreatic ductal adenocarcinoma has yet to benefit. Innate immune cells are critical to anti-tumor immunosurveillance and ...recent studies have revealed that these populations possess a form of memory, termed trained innate immunity, which occurs through transcriptomic, epigenetic, and metabolic reprograming. Here we demonstrate that yeast-derived particulate β-glucan, an inducer of trained immunity, traffics to the pancreas, which causes a CCR2-dependent influx of monocytes/macrophages to the pancreas that display features of trained immunity. These cells can be activated upon exposure to tumor cells and tumor-derived factors, and show enhanced cytotoxicity against pancreatic tumor cells. In orthotopic models of pancreatic ductal adenocarcinoma, β-glucan treated mice show significantly reduced tumor burden and prolonged survival, which is further enhanced when combined with immunotherapy. These findings characterize the dynamic mechanisms and localization of peripheral trained immunity and identify an application of trained immunity to cancer.
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