H2O Vapor Research Articles

Feasibility study of a new solar based trigeneration system for fresh water, cooling, and electricity production

The utilization of solar energy to generate electricity, cooling, and freshwater in remote areas in a sustainable way still poses lots of challenges to researchers. The aim of the current study is to design a new solar-operated trigeneration system to produce electricity, cooling, and fresh water using parabolic trough collectors in remote areas. Electric power is generated by using Organic Rankine Cycle, and cooling and fresh water (using freezing desalination technique) are obtained by two-stage NH3–H2O vapor absorption system run by solar energy. Simulation results show that for PTC arrays of 200 m2, an electrical output obtained is 3.3 kW, cooling rate is 20.4 kW, and mass flow rate of freshwater produced is 36 kg/h for an average solar irradiation of 0.7 kW/m2. Furthermore, sensitivity analysis is conducted by varying the parameter like solar irradiation, evaporator temperature, seawater inlet temperature, etc. and their effect on performance characteristics of the overall setup is investigated.

The UV Effect on the Chemiresistive Response of ZnO Nanostructures to Isopropanol and Benzene at PPM Concentrations in Mixture with Dry and Wet Air

Towards the development of low-power miniature gas detectors, there is a high interest in the research of light-activated metal oxide gas sensors capable to operate at room temperature (RT). Herein, we study ZnO nanostructures grown by the electrochemical deposition method over Si/SiO2 substrates equipped by multiple Pt electrodes to serve as on-chip gas monitors and thoroughly estimate its chemiresistive performance upon exposing to two model VOCs, isopropanol and benzene, in a wide operating temperature range, from RT to 350 °C, and LED-powered UV illumination, 380 nm wavelength; the dry air and humid-enriched, 50 rel. %, air are employed as a background. We show that the UV activation allows one to get a distinctive chemiresistive signal of the ZnO sensor to isopropanol at RT regardless of the interfering presence of H2O vapors. On the contrary, the benzene vapors do not react with UV-illuminated ZnO at RT under dry air while the humidity’s appearance gives an opportunity to detect this gas. Still, both VOCs are well detected by the ZnO sensor under heating at a 200–350 °C range independently on additional UV exciting. We employ quantum chemical calculations to explain the differences between these two VOCs’ interactions with ZnO surface by a remarkable distinction of the binding energies characterizing single molecules, which is −0.44 eV in the case of isopropanol and −3.67 eV in the case of benzene. The full covering of a ZnO supercell by H2O molecules taken for the effect’s estimation shifts the binding energies to −0.50 eV and −0.72 eV, respectively. This theory insight supports the experimental observation that benzene could not react with ZnO surface at RT under employed LED UV without humidity’s presence, indifference to isopropanol.

Engineering Model for Predicting the Intradiffusion Coefficients of Hydrogen and Oxygen in Vapor, Liquid, and Supercritical Water based on Molecular Dynamics Simulations

Molecular dynamics simulations are carried out to compute the intradiffusion coefficients of H2 and O2 in H2O for temperatures ranging from 275.15 to 975.15 K and pressures ranging from 0.1 to 200 MPa. These conditions span vapor, liquid, and supercritical conditions. For the vast majority of the state points examined, experimental data are not available. The accuracy of six H2 and six O2 force fields is tested in reproducing the available experimentally measured densities, self-diffusivities, and shear viscosities of the pure gas and the intradiffusivity of the gas in H2O. Namely, we screen the H2 force fields developed by Buch, Vrabec and co-workers, Hirschfelder et al., Cracknell, a modified Silvera–Goldman, and Marx and Nielaba. For O2, the force fields by Bohn et al., Miyano, Coon et al., Hansen et al., Vrabec et al., and Watanabe are tested. Overall, the force fields by Buch and Bohn for H2 and O2, respectively, were found to perform the best, and combined with the TIP4P/2005 H2O force field are used to compute the intradiffusivities in the entire temperature and pressure range. The new data are used to develop an engineering model that can predict the H2 and O2 intradiffusivity in vapor, liquid, and supercritical H2O. The new model uses 11 parameters and has an accuracy of 4–11%. The model is validated with other available experimental and simulation data for H2 and O2 in H2O and pure H2O. Aside from the extensive collection of new data for the intradiffusivities of H2 and O2 in H2O, we present new data for the densities, shear viscosities, and self-diffusivities of pure TIP4P/2005 H2O in the same wide temperature and pressure range. The new data and the engineering model presented here can be used for the design and optimization of chemical processes, for which the knowledge of H2 and O2 diffusivities in H2O is important.

Cubes to Cubes: Organization of MgO Particles into One-Dimensional and Two-Dimensional Nanostructures.

Developing simple, inexpensive, and environmentally benign approaches to integrate morphologically well-defined nanoscale building blocks into larger high surface area materials is a key challenge in materials design and processing. In this work, we investigate the fundamental surface phenomena between MgO and water (both adsorption and desorption) with particles prepared via a vapor-phase process (MgO nanocubes) and a modified aerogel process (MgO(111) nanosheets). Through these studies, we unravel a strategy to assemble individual MgO nanoparticles into extended faceted single-crystalline MgO nanosheets and nanorods with well-defined exposed surfaces and edges. This reorganization can be triggered by the presence of H2O vapor or bulk liquid water. Water adsorption and the progressive conversion of vapor-phase grown oxide particles into hydroxides give rise to either one-dimensional or two-dimensional (1D or 2D) structures of high dispersion and surface area. The resulting Mg(OH)2 lamella with a predominant (001) surface termination are well-suited precursor structures for their topotactic conversion into laterally extended and uniform MgO(111) grain surface configurations. To understand the potential of polar (111) surfaces for faceting and surface reconstruction effects associated with water desorption, we investigated the stability of MgO(111) nanosheets during vacuum annealing and electron beam exposure. The significant surface reconstruction of the MgO(111) surfaces observed shows that adsorbate-free (111)-terminated surfaces of unsupported MgO nanostructures reconstruct rather than remain as charged planes of either three-fold coordinated O2– ion or Mg2+ ions. Thus, here we demonstrate the role water can play in surface formation and reconstruction by bridging wet chemical and surface science inspired approaches.

A tenuous, collisional atmosphere on Callisto

A simulation tool which utilizes parallel processing is developed to describe molecular kinetics in 2D, single- and multi-component atmospheres on Callisto. This expands on our previous study on the role of collisions in 1D atmospheres on Callisto composed of radiolytic products (Carberry Mogan et al., 2020) by implementing a temperature gradient from noon to midnight across Callisto’s surface and introducing sublimated water vapor. We compare single-species, ballistic and collisional O2, H2 and H2O atmospheres, as well as an O2+H2O atmosphere to 3-species atmospheres which contain H2 in varying amounts. Because the H2O vapor pressure is extremely sensitive to the surface temperatures, the density drops several orders of magnitude with increasing distance from the subsolar point, and the flow transitions from collisional to ballistic accordingly. In an O2+H2O atmosphere the local temperatures are determined by H2O near the subsolar point and transition with increasing distance from the subsolar point to being determined by O2. When radiolytically produced H2 is not negligible in O2+H2O+H2 atmospheres, this much lighter molecule, with a scale height roughly an order of magnitude larger than that for the heavier species, can cool the local temperatures via collisions. In addition, if the H2 component is dense enough, particles originating on the day-side and precipitating into the night-side atmosphere deposit energy via collisions, which in turn heats the local atmosphere relative to the surface temperature. Moreover, the difference between H2 atmospheric escape rates in single-species and multi-species atmospheres is small: the H2 only has to diffuse through a few hundred km of the heavier gases before it is the lone species in the atmosphere out to the Hill sphere. Finally, we discuss the potential implications of this study on the presence of H2 in Callisto’s atmosphere and how the simulated densities correlate with expected detection thresholds at flyby altitudes of the proposed JUpiter ICy moons Explorer (JUICE) spacecraft.

Thinking green: modelling respirator reuse strategies to reduce cost and waste

ObjectivesTo compare the impact of respirator extended use and reuse strategies with regard to cost and sustainability during the COVID-19 pandemic.DesignCost analysis.SettingUSA.ParticipantsAll healthcare workers within the USA.InterventionsNot applicable.Main outcome measuresA...

Removal of elemental mercury using magnetic Fe-containing carbon prepared from sludge flocculated with ferrous sulfate by zinc chloride activation

In this work, sewage sludge flocculated with ferrous sulfate (SFS) was treated by one-step pyrolysis and ZnCl2 activation to obtain magnetic Fe-containing carbon, which was used to remove elemental mercury (Hg0) from flue gas. When 30% ZnCl2 was added to SFS (names as SFS-30), sulfides, chloride, magnetic FexOy, as well as a suitable BET surface area were produced during pyrolysis. SFS-30 showed a maximum mercury removal efficiency of 96.1%. The presence of O2 and a low SO2 concentration enhanced Hg0 removal, while H2O vapor and a high concentration of SO2 inhibited it. The addition of ZnCl2 increased the BET surface area as well as the conversion of sulfate to sulfide, which were both beneficial for Hg0 removal. In addition, the generated magnetism during the pyrolysis process assisted in the recovery and utilization of SFS-30 in flue gas. After being magnetically separated from a mixture with fly ash, spent SFS-30 was thermally regenerated and recycled. After 8 Hg0 capture and regeneration cycles, the removal efficiency was not notably degraded, demonstrating that SFS-30 prepared by one-step pyrolysis with ZnCl2 activation can be used for Hg0 removal. The results of this study have guiding significance for practical engineering applications of this material.

Reactivity of anatase and rutile titanium dioxide powder with hydrogen peroxide vapour: Implication for reactive coating systems for laundry enzymes

The reactivity of solid particles of two forms of TiO2, rutile and anatase, with H2O2 vapour was investigated for use as reactive coatings protecting granular formulations of enzymes. Reactivity tests using potassium titanium oxide oxalate as a competition probe showed a high reactivity of anatase at both high and low H2O2 pressure, whereas rutile was moderately reactive only at high H2O2 pressure. Heating H2O2-treated rutile and anatase led to release of oxygen, but not of surface-bound H2O2. For rutile, electron spin resonance measurements showed formation of radical intermediates. Anatase showed a mechanism comprising reversible binding of H2O2 and catalytic cleavage of H2O2 without formation of radicals. Anatase-coated detergent enzyme granules confirmed the protection against H2O2 vapour. Overall, this work shows the potential of anatase as a reactive coating material in laundry granules as an alternative to the current formulation.

Nano-Laminated Metal Oxides/Polyamide Stretchable Moisture- and Gas-Barrier Films by Integrated Atomic/Molecular Layer Deposition.

Stretchable barrier films capable of maintaining high levels of moisture- and gas-barrier performance under significant mechanical strains are a critical component for wearable/flexible electronics and other devices, but realization of stretchable moisture-barrier films has not been possible due to the inevitable issues of strain-induced rupturing compounded with moisture-induced swelling of a stretched barrier film. This study demonstrates nanolaminated polymer/metal oxide stretchable moisture-barrier films fabricated by a novel molecular layer deposition (MLD) process of polyamide-2,3 (PA-2,3) integrated with atomic layer deposition (ALD) metal oxide processes and an in situ surface-functionalization technique. The PA-2,3 surface upon in situ functionalization with H2O2 vapor offers adequate surface chemisorption sites for rapid nucleation of ALD oxides, minimizing defects at the PA-2,3/oxide interfaces in the nanolaminates. The integrated ALD/MLD process enables facile deposition and precise structural control of many-layered oxide/PA-2,3 nanolaminates, where the large number of PA-2,3 nanolayers provide high tolerance against mechanical stretching and flexing thanks to their defect-decoupling and stress-buffering functions, while the large number of oxide nanolayers shield against swelling by moisture. Specifically, a nanolaminate with 72 pairs of alternating 2 nm (5 cycles) PA-2,3 and 0.5 nm HfO2 (five cycles) maintains its water vapor transmission rate (WVTR) at the 10-6 g/m2 day level upon 10% tensile stretching and 2 mm-radius bending, a significant breakthrough for the wearable/flexible electronics technologies.

The petrologic and degassing behavior of sulfur and other magmatic volatiles from the 2018 eruption of Kīlauea, Hawaiʻi: melt concentrations, magma storage depths, and magma recycling

Kīlauea Volcano’s 2018 lower East Rift Zone (LERZ) eruption produced exceptionally high lava effusion rates and record-setting SO2 emissions. The eruption involved a diverse range of magmas, including primitive basalts sourced from Kīlauea’s summit reservoirs. We analyzed LERZ matrix glasses, melt inclusions, and host minerals to identify melt volatile contents and magma storage depths. The LERZ glasses and melt inclusions span nearly the entire compositional range previously recognized at Kīlauea. Melt inclusions in Fo86-89 olivine from the main eruptive vent (fissure 8) underwent 70–170 °C cooling during transport in LERZ carrier melts, causing extensive post-entrapment crystallization and sulfide precipitation. Many of these melt inclusions have low sulfur (400–900 ppm) even after correction for sulfide formation. CO2 and H2O vapor saturation pressures indicate shallow melt inclusion trapping depths (1–5 km), consistent with formation within Kīlauea’s Halemaʻumaʻu and South Caldera reservoirs. Many of these inclusions also have degassed δ34S values (− 1.5 to − 0.5‰). Collectively, these results indicate that some primitive melts experienced near-surface degassing before being trapped into melt inclusions. We propose that decades-to-centuries of repeated lava lake activity and lava drain-back during eruptions (e.g., 1959 Kīlauea Iki) recycled substantial volumes of degassed magma into Kīlauea’s shallow reservoir system. Degassing and magma recycling from the 2008–2018 Halemaʻumaʻu lava lake likely reduced the volatile contents of LERZ fissure 8 magmas, resulting in lower fountain heights compared to many prior Kīlauea eruptions. The eruption’s extreme SO2 emissions were due to high lava effusion rates rather than particularly volatile-rich melts.

Experiment based modeling of CO2 solubility in H2O at 313.15–473.15 K and 0.5–200 MPa

CO2 solubility data in water at subsurface temperature and pressure conditions is important in global carbon cycle research. We measured the solubility of CO2 in H2O at a wide range of temperature from 313.15 to 473.15 K, and at the pressures from 0.5 to 200 MPa, and analyzed the effect of H2O vapor in the high-pressure-high-temperature (HPHT) system. The measured solubility is remarkably similar to published data at similar pressure/temperature ranges, while greater than the calculated values of existing prediction models at HPHT. This discrepancy is caused by the unneglectable increase of H2O vapor at HPHT, i.e., the decrease of liquid H2O in the system. The experiment data also suggests the dependence of CO2 solubility on temperature and pressure varies in different pressure-temperature regions. In the low-pressure region, the solubility depends predominantly on pressure and the value is small (generally smaller than 1 mol/kg). In the intermediate pressure region, solubility depends mostly on pressure, but the dependency is less than that in the low-pressure region. In the high-pressure region, temperature outweighs pressure in influencing the solubility. The sectional model provides more accurate estimations of CO2 solubility in H2O.

Boosting CsPbBr3‐Driven Superior and Long‐Term Photocatalytic CO2 Reduction under Pure Water Medium: Synergy Effects of Multifunctional Melamine Foam and Graphitic Carbon Nitride (g‐C3N4)

Achieving high‐efficiency and long‐term CO2 photoreduction under an aqueous environment is still a challenge for CsPbBr3‐based catalysts due to the poor humidity resistance. Herein, multifunctional melamine foam (MF) and graphitic carbon nitride (g‐C3N4) are selected to modify CsPbBr3, successfully realizing efficient and long‐term CO2 reduction under pure H2O medium. The 3D framework of MF can support CsPbBr3, avoiding its degradation due to direct contact with the aqueous solution. In addition, the abundant porosity of MF can accelerate H2O evaporation, achieving sufficient blending of CO2 with H2O vapor. These functions lead to the enormously enhanced conversion efficiencies of MF/CsPbBr3 and MF/g‐C3N4 compared to powdery catalysts. Photocatalytic activities of MF/CsPbBr3‐g‐C3N4 are further improved due to the accelerated charge migration, and accordant sites of electron accumulation and CO2 adsorption in composites. The best product yield of the composite is 975.57 μmol g−1 h−1, and the corresponding electron consumption rate reaches 2571.27 μmol g−1 h−1, surpassing almost all the already reported CsPbBr3‐based catalysts whether in H2O or organic solvent media. Moreover, the strong surface hydrophobicity and excellent photothermal effect of MF/CsPbBr3‐g‐C3N4 result in long‐term and stable photocatalytic activity, with no obvious CO and CH4 decrease after continuous reaction for 76 h.

Influences of 4ZnO·B2O3·H2O whisker based intumescent flame retardant on the mechanical, flame retardant and smoke suppression properties of polypropylene composites

AbstractIn this work, the influences of 4ZnO·B2O3·H2O zinc borate (ZB) whisker based intumescent flame retardant (IFR) containing ammonium polyphosphate and dipentaerythritol on the mechanical, flame retardant and smoke suppression properties of polypropylene (PP) composites were characterized by the universal testing machine, UL‐94, limiting oxygen index (LOI), and cone calorimeter tests, respectively. The results indicate that only 1 phr of ZB could effectively improve the LOI value and slow down the burning rate of PP composite. The peak heat release rate, average of HRR, total heat release, peak smoke production rate, and total smoke production values are all decreased from 413.8 kW/m2, 166.3 kW/m2, 82.3 MJ/m2, 0.0995 m2/s, and 17.9 m2 for PPc/20IFR composite to 267.8 kW/m2, 128.3 kW/m2, 66.8 MJ/m2, 0.0478 m2/s, and 12.6 m2 for PPc/20IFR/1ZB composite, respectively. The scanning electron microscopy images, energy dispersive spectrometry, and Raman spectra of char residue reveal that ZB is helpful to form a compact and graphitized intumescent char residue so that the heat diffusion and oxygen transmission are greatly hindered. The thermogravimetry analysis‐fourier transform infrared spectroscopy (TGA‐FTIR) results show that less combustible volatiles and more H2O vapor are generated with the appearance of ZB. Hence, the combustion mechanism in gas phase is suppressed.

Crystalline hydroxyapatite coating by hydrolysis using β-tricalcium phosphate target by pulsed-laser deposition

Α β-tricalcium phosphate target was employed to decrease the annealing temperature for crystalline hydroxyapatite coating through a hydrolysis process by pulsed-laser deposition. The crystalline hydroxyapatite content of calcium phosphate coating layers was quantitatively evaluated using Raman spectroscopy and X-ray diffraction, and compared with that of pure polycrystalline powder. Calcium phosphate changes from an amorphous phase to crystalline hydroxyapatite through a crystalline α-tricalcium phosphate phase at around 400 °C under an H2O vapor pressure of 0.1 Torr. The crystalline hydroxyapatite content increases steeply by hydrolysis at 500 °C as the H2O vapor pressure is increased from vacuum to 0.15 Torr, but then decreases somewhat at higher pressure. These results indicate that excessive gas pressure blocks small ablated particles such as atoms, ions, molecules, and clusters that would typically be completely hydrolyzed instantaneously following deposition on the substrate.

High-resolution neutron imaging reveals kinetics of water vapor uptake into a sessile water droplet

•High-resolution neutron imaging visualizes the evaporation of a sessile droplet •The neutron imaging traces a deuterated component in the evaporating droplet •FTIR spectroscopy and diffusion-based model support the neutron imaging observation The spatiotemporal distribution of multiple components and phases governs their evaporation and condensation at the liquid-vapor interface. However, in situ methods to characterize the distribution remain challenging, despite the significance of understanding the ubiquitous mass transport phenomena. Here, we introduce high-resolution neutron imaging as a versatile method to quantify the composition of a sessile droplet in situ, under evaporation and condensation. To prove the concept, we perform a neutron transmittance analysis of a sessile heavy water (D2O) droplet and measure the fraction change of H2O to D2O by the sorption of ambient H2O vapor during the evaporation. Our observations are consistent with ex situ Fourier transform infrared spectroscopy measurements and our diffusion-based numerical model. Our results demonstrate that, with deuterated components having a physicochemical similarity with their hydrogenated counterparts, high-resolution neutron imaging can trace composition changes in nonequilibrium phenomena, such as evaporation and condensation. The spatiotemporal distribution of multiple components and phases governs their evaporation and condensation at the liquid-vapor interface. However, in situ methods to characterize the distribution remain challenging, despite the significance of understanding the ubiquitous mass transport phenomena. Here, we introduce high-resolution neutron imaging as a versatile method to quantify the composition of a sessile droplet in situ, under evaporation and condensation. To prove the concept, we perform a neutron transmittance analysis of a sessile heavy water (D2O) droplet and measure the fraction change of H2O to D2O by the sorption of ambient H2O vapor during the evaporation. Our observations are consistent with ex situ Fourier transform infrared spectroscopy measurements and our diffusion-based numerical model. Our results demonstrate that, with deuterated components having a physicochemical similarity with their hydrogenated counterparts, high-resolution neutron imaging can trace composition changes in nonequilibrium phenomena, such as evaporation and condensation.

Recovery of calcium sulfide from Tunisian phosphogypsum and olive mill wastewaters: a thermogravimetric and kinetic study

Large amounts of phosphogypsum (PG) and olive mill wastewaters (OMW) are rejected regularly in the environment. This paper deals with the valorization of both PG and OMW from Tunisia in order to recover calcium sulfide. It consists in studying the reduction of the former using the latter as a source of carbon, in nitrogen atmosphere with or without H2O vapor. Experiments were carried out by thermogravimetry in non-isothermal mode, and the solids were identified by X-ray diffraction. Raw (OMWR) and preheated samples (OMWP) of OMW were used, and the PG over OMW mass ratio was varied to find the stoichiometric proportion of the reaction between CaSO4 and carbon. It was found that in pure N2 atmosphere the use of OMW as a carbon source allows to significantly reduce both the onset reduction temperature and the reduction temperature interval: the PG reduction takes place in the temperature range of 600–750 °C (instead of 750–1080 °C with pure carbon) leading to CaS formation. Utilizing Kissinger–Akahira–Sunose, Flynn–Wall–Ozawa, Kissinger, Satava-Sestak and master plots methods, activation energies, pre-exponential factors and the mechanism models of the reduction reaction were determined. The best models for PG + OMWP at 1.42 mass ratio and PG + OMWR at 0.23 mass ratio mixtures are Avrami-Erofeev A3 and A2 mechanisms, respectively. The kinetic models corresponding to the latter mixtures are: $$\frac{{{\text{d}}\alpha }}{{{\text{d}}t}} = 2.68~ \times 10^{{13}} {\text{~exp}}\left( { - \frac{{242.70~ \times 10^{3} }}{{RT}}} \right) \times 3\left( {1 - \alpha } \right)\left( { - \ln \left( {1 - \alpha } \right)} \right)^{{{\raise0.7ex\hbox{$2$} \!\mathord{\left/ {\vphantom {2 3}}\right.\kern-\nulldelimiterspace} \!\lower0.7ex\hbox{$3$}}}}$$ and $$\frac{{{\text{d}}\alpha }}{{{\text{d}}t}} = 1.32~ \times 10^{{12}} ~\exp \left( { - \frac{{214.92~ \times 10^{3} }}{{RT}}} \right) \times 2\left( {1 - \alpha } \right)\left( { - \ln \left( {1 - \alpha } \right)} \right)^{{{\raise0.7ex\hbox{$1$} \!\mathord{\left/ {\vphantom {1 2}}\right.\kern-\nulldelimiterspace} \!\lower0.7ex\hbox{$2$}}}}$$ , respectively. In wet atmosphere, the conversion rate of this reaction decreases by about 16% and the determined activation energies in that atmosphere were higher than in pure N2 one, supposing that the reduction reaction was influenced negatively by the wet atmosphere.

Atomic-level insights into the activation of nitrogen via hydrogen-bond interaction toward nitrogen photofixation

Summary As the activation of N2 molecules is generally regarded as the bottleneck in N2 reduction, it is of significant importance to develop promising strategies to efficiently activate N2 molecules. Herein, we discovered an innovative approach to activate N2 molecules via hydrogen-bond interaction in N2 photofixation. Porous Cu with surface modification of S atoms (3%-S/Cu) exhibited remarkable catalytic activity and stability in N2 photofixation. Further mechanistic studies revealed that surface S atoms directly participated in the catalytic process by accepting and donating H atoms. In addition, the forming S–H bond significantly promoted the activation of N2 molecules via hydrogen-bond interaction, contributing to the enhanced catalytic activity.

Cell cycle regulation in human hair follicle dermal papilla cells using nonthermal atmospheric pressure plasma-activated medium.

Nonthermal atmospheric pressure (NAP) plasmas have recently been developed and have been used for wound healing, blood coagulation, and cancer therapy. NAP plasmas can induce either cell proliferation or cell death, depending on the dose. Due to their efficacy and application easily, plasma activated mediums (PAMs) have been used in human cells recently.In atmosphere, NAP plasmas react with molecular content of air such as N2, O2, H2O vapor, etc, and generate a variety of reactive oxygen and nitrogen species. High reactive oxygen species (ROS) levels promote damage of cellular DNA, proteins, and lipids. Such damage can lead to cell-cycle arrest, and cellular death. However, low levels of ROS have been caused an increase in cell cycle progression.Human skin is arranged in 3 layers, including (from top to bottom) the epidermis (and its appendages), the dermis, and the hypodermis. Human dermal papilla cells (DPCs) are located in the middle or even deep part of the dermis. DPCs play a key role in hair regeneration, and a lot of effort have been made to promote DPC hair formation ability. DPC is increased proliferation, delayed senescence, and enhanced hair by depending on the amount of ROS through the NAP-PAM treatment.In this study, we used NAP plasmas to the human hair follicle DPCs exposed from 0 to 20 minutes, so we were investigated the effects of PAM on cell proliferation and cell cycle progression. After NAP-PAM treatment for 24 hours, cell cycle was arrested in the G0/G1 phase. The NAP-PAM-treated human hair follicle DPCs recovered gradually after 48 hours of the treatment compared to the untreated cells.Therefore, this approach offers promising results for further application of NAP-PAM in clinical dermatology. In future, it can be applied clinically in the form of active water that can delay the progression of baldness and alopecia areata.

Surface activation of poly(methyl methacrylate) for microfluidic device bonding through a H2O plasma treatment linked with a low-temperature annealing

This paper reports on a rapid, lossless process for the bonding of poly(methyl methacrylate) (PMMA) substrates for use in microfluidic devices for blood tests, utilizing H2O plasma, and H2O linked rapid thermal annealing (RTA) treatments. The bonding of PMMA produced with H2O plasma linked with RTA was analyzed, and its effect on the bonding of free radicals was investigated. The PMMA surface treatment was performed at constant RF power and H2O vapor flow but changing plasma treatment times in both processes. The surface modification of the PMMA subjected to the H2O plasma treatment was studied by optical emission spectroscopy, which confirmed that the relative intensity of hydroxyl radicals and oxygen emission peaks. The surface of the PMMA after being subjected to the plasma linked with RTA treatment was also characterized. The free energy increased with the plasma treatment time. The tensile test results revealed that the strength of OH bonds on the PMMA surface increased with a high plasma treatment time of 120 s. After bonding, UV–visible transmission spectrum measurements revealed that the transparency of the microfluidic device increased. We demonstrated the bonding of a microfluidic device with plasma treatment without deformation. This method provides an ideal bonding technique for the manufacture of microfluidic devices with PMMA. This technique has more advantages than other bonding techniques.

Modeling and analysis of CO2 capture by aqueous ammonia + piperazine blended solution in a spray column

Chemical scrubbing using NH3/PZ solution is a promising pathway for mitigating CO2 emission from fossil-fuel combustion. Herein, we developed an advanced model that can predict CO2 absorption using the blended solvent in a spray column. The model was established in the computational fluid dynamics framework coupled with the properties of the blended solvent. The blended properties were evaluated using the linear combination of each single solvent. The established model was also verified by our previous experimental results. The deviations were found to be within ±15%. Further case studies revealed crucial characteristics of the scrubbing process. Due to the entrainment effect, intensive back-mixing behavior was observed in the gas flow. Energy analysis showed that the heat for water warming-up and evaporation mainly comes from the heat released by the CO2 absorption. The profiles of the gaseous species demonstrated that gaseous concentrations of NH3 and H2O vapor quickly approached their equilibrium values, whereas gaseous CO2 concentration exhibited different variation trends along the column. We also found that the gas-side mass-transfer coefficient was two orders of magnitude greater than the liquid-side. Moreover, the spatial separation of the maximum mass-transfer coefficients and the driving force led to a low CO2 absorption rate. The comparisons of the upward and downward spraying schemes indicated that the upward spraying can mitigate the spatial separation and increase droplet residence time and volume fraction, significantly improving the CO2 removal efficiency from 48.2% to 55.9%.