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We propose a novel interference alignment (IA) technique with receive antenna partitioning (RAP) for simultaneous wireless information and power transfer (SWIPT)-enabled downlink fog radio access networks (F-RANs). The basic idea of the proposed scheme is to apply a generalized downlink IA for each access point (AP) and to divide receive antennas at each user into two groups for information decoding (ID) and energy harvesting (EH), respectively. With the proposed scheme, an optimal receive antenna configuration at each user is obtained to maximize the weighted sum of achievable rate and the sum of harvested energy of the network. Also we develop an antenna configuration selection algorithm to obtain near-optimal performance with low computational complexity. Through extensive computer simulations, it is shown that the proposed scheme significantly improves a rate-energy region compared with existing techniques.

In this paper, we mathematically analyze bit-error rate (BER) and diversity order of physical-layer network coding (PNC) scheme in the two-way relay channel (TWRC) under the assumption of multiple antennas at relay node. We assume the quadrature phase shift keying (QPSK) modulation for simple data transmission in IoT applications, and max–min transmit antenna selection (TAS) scheme in the broadcast (BC) phase for achieving full diversity gain. In particular, we obtain the upper bound of BER at the multiple access (MA) phase, while deriving the exact BER performance at the BC phase. To the best our knowledge, the mathematical analysis in this paper is the first analytical results in the literature. Through computer simulations, the analytical results are validated.

Ammonia can be applied as a hydrogen carrier and used directly as a hydrogen production supply. In this paper, a technique for mass-producing hydrogen from ammonia water is proposed by applying a liquid phase plasma (LPP) discharge technique and a photocatalyst. In this reaction, N- and Fe ion codoped TiO2 (N/Fe/TiO2) photocatalysts were prepared and applied as a visible light-sensitive photocatalyst. N/Fe/TiO2 (NFT) had a similar crystal shape and size to anatase TiO2, but the surface was doped with metal ions. The bandgap of the NFT photocatalyst obtained from the spectrum measured by photoluminescence spectroscopy was approximately 2.4 eV. Nitrogen and Fe ions played a role in narrowing the gap between the conduction band (CB) and valence band (VB) of TiO2, effectively reducing the bandgap. In the decomposition reaction of ammonia water by LPP irradiation, the NFT photocatalyst showed the highest hydrogen evolution rate. The amount of hydrogen produced from ammonia water by LPP irradiation on the NFT photocatalyst was approximately 133 L/h. The hydrogen production rate obtained from ammonia water by the photocatalyst and LPP irradiation was significantly higher than that obtained by the ammonia electrolysis process.

Here, catalytic fast pyrolysis (CFP) was studied as a method to valorize rice husk (RH). Specifically, the effects of RH pretreatment, i.e., NaOH treatment, on the CFP efficiency and selectivity over a Ga-loaded HZSM-5 (SiO2/Al2O3 ratio = 38) were investigated. In addition to NaOH pretreatment, it was investigated how pyrolysis medium (N2, CH4, or a gas stream evolved from ex-situ CH4 decomposition over a Ni/La2O3/CeO2/Al2O3 catalyst (Ni/La2O3/CeO2 = 2/1/1) at 923 K (d-CH4)) influences the CFP of pretreated RH. The NaOH treatment reduced the content of ash and increased the content of cellulose in the RH sample. Thus, the effect of pyrolysis medium on the CFP of cellulose was studied at first, followed by that on CFP of NaOH-treated RH. With regard to the pyrolysis medium, the yield of aromatic compounds such as benzene, toluene, ethylbenzene, and xylene (BTEX) achieved with both cellulose and the NaOH-treated RH enhanced in an order; d-CH4 > CH4 > N2. The removal of ash from RH with the NaOH pretreatment increased the BTEX yield up to 22.3 wt% as ash (mineral impurities) affects pyrolytic behavior of cellulose and lowers accessibility of pyrolytic volatiles to acid sites on zeolite. This study gives helpful information about how different parameters influence the conversion of RH into BTEX via CFP process.

In this study, europium (Eu) was precipitated in TiO2 powder using liquid phase plasma (LPP) process to prepare a photocatalyst with higher activity, even in the visible light range. Eu was uniformly deposited on the surface of TiO2 by the LPP method. It was observed that the amount of Eu precipitated on the TiO2 surface increased with increasing precursor concentration. XPS and EDS analysis showed that Eu was precipitated as europium oxide. The precipitation of Eu shifted the position of the Raman peak to a higher wavelength; with higher Eu content, the band gap energy decreased. Particularly, the photocatalytic efficiency of the Eu doped TiO2 photocatalyst (EDTP) in the visible light source was much higher than that of bare TiO2, and with higher Eu content, the photocatalytic activity was improved. Acetylsalicylic acid was attacked by HO∙ produced on the EDTP’s surface and assumed to be finally mineralized to H2O and CO2 via two decomposition pathways, namely, decarboxylation and deacetylation.

Alkaline earth (AE) metals are irreplaceable ingredients in the synthesis of AE metal-based antiperovskite oxides, and it can be achieved by a chemical reduction of a stable AE metal compound. In this study, hydrogen and carbothermal reduction of BaO and BaCO3 were employed, and we here report an undesirable side reaction creating barium hydroxide (Ba(OH)2) as the product of the reaction with the small amount of water in ultra-high purity inert gas used in the reduction processes. Such side reaction pathways and products are hardly identifiable in a high-temperature reaction; yet, systematic investigations on phase evolutions using X-ray diffraction, IR spectroscopy, and thermogravimetric analysis enabled the detection of Ba(OH)2·xH2O. Unintentional creation of alkaline earth metal oxides in intermediate and subsequent hydration even under a negligible amount of H2O may lead to an unexpected loss of alkaline earth metal element and, consequently, its deficiency in a desired final product.

This cross-sectional study examined the relationship between depression, physical health, interpersonal problems, and binge-eating behavior among South Korean nurses. Self-report questionnaires were answered by 187 nurses from five hospitals. Mediating roles of depression and physical health between interpersonal problems and binge-eating behavior were examined using mediation analyses with bootstrapping. Total and direct effects of interpersonal problems on binge-eating behavior were significant. Indirect effects of path through depression and physical health as mediators, and through single mediation of physical health were significant, while indirect effects through depression were not. Thus, physical health affects nurses' vulnerability to interpersonal problems and binge-eating behavior.

Present study evaluated the catalytic steam gasification of furniture waste to enhance the biohydrogen production. To do this, 10 wt% nickel loaded catalysts on the variety of supports (Al2O3, CeO2, CeO2-La2O3, and CeO2–ZrO2) were prepared by the novel solvent deficient method. The hydrogen selectivity (vol%) order of the catalysts was achieved as Ni/CeO2–ZrO2>Ni/CeO2>Ni/Al2O3≃Ni/CeO2-La2O3. The best catalytic activity of Ni/CeO2–ZrO2 catalyst (~82 vol % H2 at 800 °C) was ascribed to the smaller size of nickel crystals, finely dispersed Ni on the catalyst surface, and Ce1-xZrxO2-δ solid solution. The role of Ce1-xZrxO2-δ solid solution in Ni/CeO2–ZrO2 catalyst was observed as bi-functional; acceleration of water-gas-shift and oxidation of carbon reaction. The high resistance of Ni/CeO2–ZrO2 towards the coke formation showed its potential to establish a cost-effective commercial-scale biomass steam gasification process. This study is expected to provide a promising solution for the disposal of furniture wastes for production of clean energy (biohydrogen).

Different types of cobalt-based mixed oxide catalysts (20 wt%Co/MgO, 5 wt%Cu-20 wt% Co/MgO, 20 wt%Co/50%MgO–50%Al2O3) were synthesized by the co-precipitation method and applied for hydrogen production from glycerol steam reforming. The catalysts were characterized using X-ray diffraction (XRD), H2-Temperature-programmed reduction (H2-TPR), CO2-Temperature Programmed desorption, CO-Chemisorption, and CHN techniques. The H2-TPR analysis showed the reducibility of cobalt-oxide (5Cu20CM; 5 wt%Cu-20 wt% Co/MgO) was enhanced by the copper, and reduction profiles of cobalt oxide shifted to a lower temperature (

Solving the shuttle effect caused by lithium polysulfide (LPS) dissolution is important in lithium−sulfur batteries. The anchoring of LPSs to carbon combined with sulfur is a method of suppressing the shuttle effect. This first-principles study is the first to report that amorphous carbon offers the best ability to anchor LPSs. The adsorption energies of LPSs on amorphous carbon are at least six times higher than those on graphene and at least two times higher than those on pyridinic-N doped graphene. The LPSs adsorbed on amorphous carbon undergo significant molecular distortion and/or partial dissociation due to the S-to-C electron transfer of 1.2–1.8 e per molecule, as well as the formation of strong bonds between both the Li and S atoms and the sp- and sp2-site C atoms. We propose an amorphous carbon−graphite hybrid anchoring material, because amorphous carbon can strongly capture LPSs and graphite can act as an electron channel.

Catalytic co-conversion of Kraft lignin (KL) and linear low-density polyethylene (LLDPE) over mesostructured catalysts was examined using a micro-pyrolyzer equipped with gas chromatography-mass spectrometry/flame ionization detector (MPy-GC/MS/FID). Mesoporous catalysts of Al-SBA-15 and mesoZSM-5 were synthesized and characterized by N2 sorption, ammonia temperature programmed desorption, and X-ray diffraction. The characterization results indicated that mesoZSM-5 had the smaller average pore size (4.10 nm) than Al-SBA-15 (10.70 nm), but its total acidity (both weak and strong acid sites) was much higher than Al-SBA-15. When they were applied as catalysts in the pyrolysis of KL and LLDPE, the mesoZSM-5 exhibited higher catalytic activity for aromatic hydrocarbon production due to its higher acidity and MFI pore structure. Indeed, synergistic synthesis of aromatic hydrocarbons was achieved via the catalytic co-pyrolysis of KL and LLDPE because of the H-donating effect of LLDPE; the experimental yields (GC/MS area; abundance vs. time) of aromatic hydrocarbons in the oils obtained from catalytic co-pyrolysis of KL/LLDPE (1:1) over Al-SBA-15 (8.76 × 107) and mesoZSM-5 (27.58 × 107) were ∼1.5 fold higher than the theoretical yields.

Ethanolamine released from a nuclear power plant was degraded by photocatalytic decomposition using plasma in the liquid phase with metal-incorporated photocatalysts. Metal-incorporated titanium dioxide photocatalysts were employed with carbon nanotubes and carbon nanofibers as a support. The photocatalytic decomposition of ethanol amine-contained water induced the degradation of ethanolamine and H2 evolution, simultaneously. The degradation of ethanolamine and H2 evolution were elevated by incorporating Ni on titanium dioxide nanocrystallites. The rate of H2 evolution in the ethanolamine-containing water was higher than that in pure water, which was attributed to the additional H2 evolution by the photodecomposition of ethanolamine in water.

To improve the photocatalytic performance of TiO2 photocatalysts, a new method, liquid phase plasma (LPP) method, was used to introduce nitrogen and iron oxide. Interstitial or substitutional nitrogen and Fe3+ iron nanoparticles were impregnated on the surface of TiO2 by LPP reaction without additional chemical reduction agent and the amount of iron of modified TiO2 photocatalysts was affected by the amount of initial precursor. The adsorption edge of modified TiO2 photocatalysts was shifted to the visible region in proportion to the amount of nitrogen and iron oxide, and the band gap energy was decreased, and the photocatalytic activity was confirmed by PL and EPR analysis. The photocatalytic activities of modified TiO2 photocatalysts were measured under UV and blue LED lamps and compared with pure TiO2 powder (P-25). The modified TiO2 exhibited better photocatalytic degradation performance than pure TiO2 under blue LED light conditions, but exhibited low degradation activity under UV LED light conditions. Through GC–MS analysis, it was found that the methylene blue was finally decomposed into an inorganic substance through intermediates such as benzene sulfonic acid and phenol by OH radicals. From these results, we found that the modified TiO2 photocatalysts can be easily prepared using the LPP method and can be used in the visible region.

The degradation of chloroform in a liquid phase plasma (LPP) reactor was examined according to the operating parameters and other influencing factors. The operating parameters included the applied voltage, frequency, and pulse width. The effects of titanium dioxide, hydrogen peroxide, and their combination on the degradation of chloroform were evaluated in terms of the influencing factors. Increasing the operating parameters up to the maximum allowed in the LPP process made chloroform decompose much faster than that of the minimum. On the other hand, increasing either the titanium dioxide or hydrogen peroxide concentrations in the reactant solution did not always destroy the chloroform efficiently compared to degradation without their loading. Although the impact of titanium dioxide was slightly higher than that of hydrogen peroxide, the synergistic effect between them enhanced the breakdown of chloroform further. Overall, both the operating parameters and influencing factors should be determined carefully to maximize the decomposition efficiency in the given treatment system, particularly for processes involving the LPP reaction.

The preparation of LaAlO3 perovskite catalysts for the oxidative coupling of methane (OCM) using a very simple solid-state method with good reproducibility is described. To obtain high performance LaAlO3 catalysts, preparation conditions such as time, temperature, and oxygen content, which have a strong effect on the catalytic activity, are controlled during the calcination process. As the calcination time and temperature increase, the catalytic activity of LaAlO3 improves due to the good homogeneity and high crystallinity of LaAlO3 perovskite. Especially, the LaAlO3 catalyst calcined at 1350 °C for 24 h shows the highest selectivity and yield of C2 hydrocarbons. LaAlO3 catalysts calcined at various oxygen fractions show a volcano-shaped curve with respect to oxygen content in calcination gas, and the LaAlO3 catalyst prepared with an oxygen content of 5 % exhibits the best catalytic performance in this reaction. The appropriate oxygen fraction provides the LaAlO3 catalyst with a large amount of electrophilic lattice oxygen species and a sufficient amount of adsorption oxygen species, which are known to play key roles in the OCM reaction. This study clearly reveals this simple, highly reproducible, and mass-productive solid-state method as a promising preparation method for high performance LaAlO3 perovskite catalysts for OCM.

Herein, the relationship between the structure and base properties of Mg–Al hydrotalcite catalysts was comprehensively investigated in relation to heat treatment and rehydration processes, which are well known as memory effects of hydrotalcite. The structure of Mg–Al hydrotalcites changed from layered double hydroxide (LDH) to mixed metal oxide and subsequently to a spinel structure during heat treatment, and it was returned from mixed metal oxide to a LDH structure by rehydration. Based on various characterizations, we successfully proposed a detailed mechanism of memory effect. We also confirmed that the Mg–Al hydrotalcites had weak or strong base sites and that their base properties could be systematically tuned by heat treatment and rehydration. The prepared Mg–Al hydrotalcites were applied to a model reaction, isomerization of glucose to fructose, as base catalysts. Among the catalysts tested, the rehydrated Mg–Al hydrotalcite efficiently produced fructose due to its appropriate base and structure properties. We finally concluded that the base sites of Mg–Al hydrotalcites can be designed as desired by heat treatment and rehydration. Moreover, through systematic design of the base sites of Mg–Al hydrotalcites, these can be promising catalysts for various heterogeneous reactions over base catalysts, giving excellent catalytic performances.

In this paper, we propose a cooperative maximum-ratio transmission (C-MRT) technique with multi-antenna relay nodes for tactical mobile ad-hoc networks (MANETs) where both the location and the number of antennas of relay nodes are arbitrary. Each relay node is assumed to know both the wireless channel coefficient from the source node to itself and the wireless channel from itself to the destination node, which is known as local channel state information (CSI) assumption. Maximum-ratio combining (MRC) and MRT techniques are used for beamforming the transmit and receive signals of the relay node, respectively. In addition, we mathematically analyze the overall outage probability of the proposed technique with moment generating function (MGF). It is shown that the mathematical analysis on the overall outage probability of the proposed C-MRT technique is matched well with the simulation results especially in high transmit power regimes. It is also observed that the proposed technique outperforms other schemes such as phase steering (PS) and optimal relay selection (ORS) in terms of outage probability.

Understanding the performance and mechanism of the degradation of various contaminants is essential for the effective design of wastewater treatment systems. This study examined the degradation of 1,4-dichlorobenzene in a photocatalytic system, which embedded TiO2 particles (as a thin film) on alumina balls (as a solid support). Decomposition of the parent compound was assessed by introducing a TiO2 photocatalyst, microwave irradiation, and ultraviolet irradiation jointly or separately (in terms of the system configuration) with and without an adjustment for the microwave intensity, pH, and hydrogen peroxide levels (in terms of the operating conditions) to the photocatalytic system. The results showed that the photocatalytic system adopting multiple processes concomitantly improved the degradation performance of the parent compound that was resistant to the single-unit processes. On the other hand, the decomposition efficiency was increased further with the sophisticated control of the operating conditions, specifically the pH and hydrogen peroxide levels. A dechlorination process as well as substitution and addition reactions involving the hydroxyl radical appeared to occur in the degradation pathway to produce four degradation products from the parent compound. The significance of this study lies in the introduction of a systematic approach to optimizing the operating conditions that facilitate the decomposition efficiency in a given photocatalytic system at no extra cost.

Water splitting from wastewater has been in the limelight because it has advantages which are hydrogen production and electrochemical oxidation at the same time. For efficient water splitting even in wastewater condition, water splitting electrodes should have cost-effectiveness and high durability. Here, we fabricated highly stable and electrocatalytic graphene on copper-nickel alloy to electrochemically produce hydrogen from wastewater in presence of carbon layer between nickel and copper. The electrode fabrication was performed by alloying the copper with nickel and growing graphene on the surface at the same time. The copper and nickel contents of electrode surface were kept by carbon layer hindering the metal diffusion at high temperature. Highly electrocatalytic activity (onset potential = 95 and 158 mV, Tafel slope = 58 and 80 mV dec−1), high durability and pH independence of graphene on copper-nickel alloy were confirmed in acidic and alkaline wastewater containing formaldehyde.

In this study, a consecutive doping method was used to improve the electrochemical properties of a commercial activated carbon (YP50f) as an electrode material for organic electric double-layer capacitors (EDLCs). In the consecutive doping method, nitrogen doping is carried out after an oxygen-doping process. Using the consecutive doping method, we prepared a carbon material with both a large specific surface area and high electrical conductivity. The specific surface area of the carbon material was mainly developed during the oxygen-doping step, whereas electrical conductivity was enhanced in the nitrogen-doping step. On the basis of the properties of the consecutively doped carbon material, we expected the prepared carbon material to exhibit good electrochemical properties when used as electrode materials for organic EDLCs. From the results of electrochemical characterizations, we observed that the consecutively doped carbon material showed a highly improved capacitance compared to the YP50f under all of the applied charge–discharge rates. Consequently, we concluded that the consecutive doping method is an effective method to prepare carbon materials with good electrochemical properties as electrode materials for organic EDLCs as a result of both their enhanced specific surface area and their enhanced electrical conductivity.

Experimental binary equilibrium data for the adsorption of hydrocarbon mixtures on activated carbon at given temperature are presented and discussed. Pure-component adsorption isotherms were fitted by using Langmuir model. Then adsorption isotherms were determined for different binary mixtures. Adsorption isotherms of binary mixtures were calculated using the real adsorbed solution theories, which requires the calculation of the activity coefficients for the components in the adsorbed phase. Activity coefficients are evaluated using Margules activity model and UNIQUAC model. We described the adsorption equilibria using proposed model parameters with taken to be equal to those of VLE. The results show that, except for a few systems, the calculated results were in good agreement with experimental adsorption equilibrium data. Keywords: Adsorption equilibria, Real adsorption solution theory, Gas-adsorbed equilibrium