The adsorption equilibria of CO 2 on zeolite 13X and zeolite X/activated carbon composite (Zeocarbon) were measured by a static volumetric method. The equilibrium experiments were conducted at (273.15, 293.15, 313.15, 333.15, and 353.15) K and at pressures up to 102.0 kPa for zeolite 13X and 99.7 kPa for Zeocarbon. The experimental data obtained were correlated by the Toth, UNILAN, and Sips models, which are generally used for microporous adsorbents such as zeolites and activated carbon. The isosteric enthalpies of adsorption were calculated for CO 2 on both adsorbents. IntroductionThe emission of CO 2 from power plants that burn fossil fuels is a major reason for the accumulation of CO 2 in the atmosphere, which causes long-term environmental problems. 1 Recently, much attention has been paid to the global warming effect caused by the excessive emission of CO 2 into the atmosphere. 2 Separation can play a key role in alleviating this problem, and the adsorption of gases and vapors by microporous solids has attracted much attention because of its great practical importance in the fields of gas separation, gas purification, and environmental problems. Therefore, adsorption is one of the most effective methods for the separation of emitted CO 2 .Information concerning the relevant adsorption equilibria is generally an essential requirement for the analysis and design of an adsorption separation process. 3 For practical applications, the adsorption equilibria must be known over a broad range of operation temperatures. Also, the isotherms of pure species are fundamental information for the dynamic simulation of adsorbers. 4 Furthermore, it is important to select the proper adsorbent for the design of an efficient adsorption process.Whereas fossil resources are limited, biomass as an adsorbent is an inexpensive, renewable, and environmentally friendly additional resource that can be found readily all over the world. 5 Recently, a zeolite X/activated carbon composite (Zeocarbon) was synthesized from rice hulls that can be used in packed beds in pelletized form. However, little information is available in the literature concerning the adsorption of any components on Zeocarbon at various temperatures.Zeocarbon was selected as an adsorbent in this study, and adsorption isotherms for CO 2 on Zeocarbon were measured and compared with those for CO 2 on zeolite 13X, which were measured previously. 6,7 In this study, commercial adsorbent pellets of zeolite 13X and Zeocarbon were used instead of crystals. The experimental data obtained at various temperatures were correlated with existing adsorption isotherm models such as the Toth, UNILAN, and Sips models.

The pH dependence and solvent isotope sensitivity of three discrete steps in the reductive half-reaction of xanthine oxidase have been investigated. The pH dependence of both kcat/Km from steady-state experiments and kred/Kdfrom rapid reaction experiments with xanthine as substrate indicate that enzyme reacts preferentially with the neutral form of substrate and that an ionizable group in the active site having a pKa of approximately 6.6 must be unprotonated for reaction to take place. The solvent kinetic isotope effect on kred/Kd is 2.4, once a uniform shift on going to D2O of approximately 1 unit for both pKa values is taken into account. The pH dependence of the formation and decay of Ered-P formed in the course the reaction of xanthine oxidase with lumazine has also been examined. Formation of this complex exhibits bell-shaped pH dependence, with pKa values of 6.5 and 7.8, consistent with the results obtained with xanthine. Decay of the Ered-P complex is base-catalyzed with a pKa > 11 and exhibits a small solvent kinetic isotope effect of 1.7 at pH/D 8.5. By contrast, the catalytic intermediate giving rise to the "very rapid" EPR signal that is transiently observed in the course of the reaction of enzyme with the substrate 2-hydroxy-6-methylpurine is found to undergo acid-catalyzed breakdown with an associated pKa < 6. Formation and decay of this species exhibit solvent kinetic isotope effects of 2.0 and 3.5 at pH 10. The results are discussed in the context of a specific reaction mechanism for the reductive half-reaction of xanthine oxidase, in which discrete ionizations associated with the molybdenum center of the active site play critical roles in determining the magnitude of the rate constants by which the Mo(IV)-P and Mo(V)-P intermediates form and decay.

Middle East respiratory syndrome (MERS) is a lethal respiratory disease — caused by MERS-coronavirus (MERS-CoV) which was first identified in 2012. Especially, pregnant women can be expected as highly vulnerable candidates for this viral infection. In May 2015, this virus was spread in Korea and a pregnant woman was confirmed with positive result of MERS-CoV polymerase chain reaction (PCR). Her condition was improved only with conservative treatment. After a full recovery of MERS, the patient manifested abrupt vaginal bleeding with rupture of membrane. Under an impression of placenta abruption, an emergent cesarean section was performed. Our team performed many laboratory tests related to MERS-CoV and all results were negative. We report the first case of MERS-CoV infection during pregnancy occurred outside of the Middle East. Also, this case showed relatively benign maternal course which resulted in full recovery with subsequent healthy full-term delivery without MERS-CoV transmission.

Only a few reports have been published on women with an infectious respiratory viral pathogen, such as Middle East Respiratory Syndrome (MERS) Coronavirus delivering a baby. A laboratory confirmed case of MERS was reported during a MERS outbreak in the Republic of Korea in a woman at gestational week 35 + 4. She recovered, and delivered a healthy baby by emergency cesarean section (C-sec). We present the clinical course and the emergency C-sec in a pregnant woman with MERS.

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A facile Mn surface doping process is proposed to improve the thermal and structural stabilities of Ni-rich layered cathode materials (Ni ≥ 80%) for lithium-ion batteries in electric vehicles. Herein, we demonstrate that the surface structure of the Ni-rich layered cathode materials can be stabilized by the introduction of a thin Mn-rich surface layer. This layer effectively reduces the direct exposure of the highly reactive Ni on the surface of the cathode materials, thus enhancing thermal stability and mitigating side reactions associated with highly reactive Ni that causes the loss of reversible capacity. In practice, the Mn surface-doped Ni-rich layered cathode material exhibits a high specific capacity with an improved cycling stability even at a high temperature (60 °C). We believe that our simple approach offers more opportunities to upscale production without any extra caution.

High-Ni cathode materials with a layered structure generally suffer from structural instability induced by a highly reactive Ni component, especially at the surface. Crystalline LiNbO 3 , with excellent thermal stability and ionic conductivity, has the potential to considerably enhance the interfacial stability of these cathode materials. By optimizing the crystalline coating of bifunctional LiNbO 3 on a high-Ni cathode material, we are able to improve cycle performance and rate capability by minimizing the direct exposure of Ni with electrolytes. Since a LiNbO 3 coating layer directly affects electrochemical performance, we also focus on the correlation of LiNbO 3 crystallinity with electrochemical behaviors of Li + in the cathode materials. We show that the Li + conducting behaviors are closely related to the crystallinity of LiNbO 3 . Highly crystalline LiNbO 3 effectively suppresses the structural changes of the cathode materials by facilitating strain relaxation induced by repeated Li + intercalation and deintercalation into and from the host structure. Moreover, it offers strong enhancement in mechanical and thermal stabilities at elevated temperatures above 60 °C. In this regard, this research provides a practical solution for successfully utilizing high-Ni layered cathode materials in commercial LIBs.

Cervical length measured by transvaginal ultrasonography is a useful and independent predictor of successful labor induction and the duration of induction and provides better predictability of successful labor induction than the Bishop score does.