Abernathymatthiesen9088

Sodium tantalate (NaTaO3) is an attractive functional material for photocatalysis. To understand its physical properties, significant efforts for milli-sized single-crystal growth of NaTaO3 have been made. However, the growth was difficult due to the smaller size in solid-state growth or probable decomposition and melting in melt growth. Recently, we grew milli-order NaTaO3 single crystals in Na2MoO4 flux. However, the reproducibility of the growth was not sufficient and hindered the stable supply of the crystal for physicochemical evaluations and further growth. The poor reproducibility was assumed to be due to the inhomogeneous, unstable growth field in response to the external atmosphere provided by nonoptimal experimental conditions. A saturated solution is considered the most suitable crystal growth field because it has the highest solubility and facilitates crystal growth with suppressed nucleation. Since supersaturation is the driving force for crystal growth, we considered that large crystals could be obtained with high frequency if growth could be controlled in the region where solubility changes rapidly. To compile a guideline for crystal growth under the control of supersaturation, the solubility of NaTaO3 in Na-based fluxes, including Na2MoO4, was studied. Using NaTaO3 molding pellets immersed in molten flux, the solubility curve for NaTaO3 was successfully measured. Based on the solubility, the optimal experimental conditions, that is, the heating temperature, the slow-cooling section, and the amount of flux as a solvent, were determined. Finally, we demonstrated the growth of NaTaO3 in Na2MoO4 flux and achieved milli-order crystals with high frequency. Our findings regarding the solubility of NaTaO3 in molten flux may assist in the stable supply of milli-order single crystals for material evaluation and larger crystal growth.Simultaneous capture of SO2 and NO x from flue gas is critical for coal-fired power generation. In this study, environmentally friendly and high-performance deep eutectic solvents based on ethylene glycol and ammonium bromide were designed to capture SO2 and NO2 simultaneously. The SO2 and NO2 absorption performances and absorption mechanisms were systematically investigated by 1H NMR and Fourier transform infrared (FT-IR) spectroscopy in combination with ab initio calculations using Gaussian software. The results showed that EG-TBAB DESs can absorb low concentrations of SO2 and NO2 from the flue gas simultaneously at low temperatures (≤50 °C). 1H NMR, FT-IR, and simulation results indicate that SO2 and NO2 are absorbed by forming EG-TBAB-SO2-NO2 complexes, Br- is the main active site for NO2 absorption, and NO2 is more active in an EG-TBAB-NO2-SO2 complex than SO2. EG-TBAB DESs exhibit outstanding regeneration capability, and absorption capacities remain unchanged after five absorption-desorption cycles. The fundamental understanding of simultaneous capture of SO2 and NO2 from this study enables DES structures to be rationally designed for efficient and low-cost desulfurization and denitrification reagents.γ-Aminobutyrate (GABA) is an important chemical by itself and can be further used for the production of monomer used for the synthesis of biodegradable polyamides. Until now, GABA production usingCorynebacterium glutamicum harboring glutamate decarboxylases (GADs) has been limited due to the discrepancy between optimal pH for GAD activity (pH 4.0) and cell growth (pH 7.0). In this study, we developed recombinant C. glutamicum strains expressing mutated GAD from Escherichia coli (EcGADmut) and GADs from Lactococcus lactis CICC20209 (LlGAD) and Lactobacillus senmaizukei (LsGAD), all of which showed enhanced pH stability and adaptability at a pH of approximately 7.0. In shake flask cultivations, the GABA productions of C. glutamicum H36EcGADmut, C. glutamicum H36LsGAD, and C. glutamicum H36LlGAD were examined at pH 5.0, 6.0, and 7.0, respectively. Finally, C. glutamicum H36EcGADmut (40.3 and 39.3 g L-1), H36LlGAD (42.5 and 41.1 g L-1), and H36LsGAD (41.6 and 40.2 g L-1) produced improved GABA titers and yields in batch fermentation at pH 6.0 and pH 7.0, respectively, from 100 g L-1 glucose. The recombinant strains developed in this study could be used for the establishment of sustainable direct fermentative GABA production from renewable resources under mild culture conditions, thus increasing the availability of various GADs.Rapid development of highly integrated electronic and telecommunication devices has led to urgent demands for electromagnetic interference (EMI) shielding materials that incorporate flame retardancy, and more desirably the early fire detection ability, due to the potential fire hazards caused by heat propagation and thermal failure of the devices during operation. Here, multifunctional flexible films having the main dual functions of high EMI shielding performance and repeatable fire detection ability are fabricated by vacuum filtration of the mixture of MXene and aramid nanofiber (ANF) suspensions. ANFs serve to reinforce MXene films via the formation of hydrogen bonding between the carbonyl groups of ANFs and the hydroxyl groups of MXene. When the ANF content is 20 wt %, the tensile strength of the film is increased from 24.6 MPa for a pure MXene film to 79.5 MPa, and such a composite film (9 μm thickness) exhibits a high EMI shielding effectiveness (SE) value of ∼40 dB and a specific SE (SSE) value of 4361.1 dB/mm. Upon fire exposure, the composite films can trigger the fire detection system within 10 s owing to the thermoelectric property of MXene. The self-extinguishing feature of ANFs ensures the structural integrity of the films during burning, thus allowing for continuous alarm signals. Moreover, the films also exhibit excellent Joule heating and photothermal conversion performances with rapid response and sufficient heating reliability.Hydrogen sulfide is toxic and corrosive gas abundantly available in nature. The activation of hydrogen sulfide to produce hydrogen and elemental sulfur is of great significance for possible applications in toxic pollutant control and hydrogen energy regeneration. The activation of H2S by transition metal atoms (M = Cr, Mn, and Fe) has been studied by low-temperature matrix isolation infrared spectroscopy and quantum chemical calculations. Experimental and theoretical results indicate that the reaction between ground-state M atoms and H2S is inhibited by the repulsive interactions between the reactants. After being excited upon photolysis, the corresponding excited-state M atoms react with H2S molecules spontaneously. The produced insertion product HMSH further decomposed to metal sulfides upon full-arc mercury lamp irradiation by the splitting of hydrogen.In this study, halogen-free flame retardants and metal synergist materials were used to enhance the flammability of PA6. PA6-based composites including various fractions of additives were manufactured using a twin-screw extruder and an injection molding machine. Mechanical, thermal, physical, morphological, and flame retardant properties were investigated with several characterization methods. The study aims to meet R22 requirements based on the EN45545 standard for fire protection of railway vehicles, according to which limiting oxygen index (LOI), smoke density, and conventional index of toxicity (CIT) values under HL3 hazard levels have to be min 32%, max 300, and max 1.5, respectively. 15FR-2MH, 15FR-5MH, 15FR-1MH-1ZB, 15FR-1MH-1BOH, and 15FR-1MH-1SIL composites exhibited both the required smoke density, CIT, and LOI values for R22. It can be said that hybrid synergists provide all requirements according to the R22-EN45545 standard. Instead of using 15FR-2MH, 15FR-1MH-1BOH led to a lower smoke density value for PA6.The deep mining of coal mines in North China faces the serious threat of water inrush from karst aquifers in the coal seam floors, and regional advance grouting technology (RAGT) is an effective means to prevent and control such disasters. However, it is difficult to choose the grouting pressure during the implementation of RAGT, and excessive grouting pressure will lead to the splitting of karst fracture and reduce the grouting effect. AZD1152-HQPA In this study, based on the Bernoulli equation, the relationship between the ground grouting pressure and critical grouting pressure during grouting is established. Based on the Hoek-Brown (H-B) strength criterion and a fracture mechanics analysis of hydraulic fracturing, a theoretical equation of the critical grouting pressure for fracture splitting during grouting is obtained. The determination methods of the main parameters, such as the length of the fracture, internal friction angle, and H-B constant of the intact rock and geological strength index, and their effects on the critical grouting pressure, are discussed. The results show that the joint influence of the H-B constant and geological strength index of the intact rock is the key factor influencing the critical grouting pressure. The theoretical research results are applied to the Xujiazhuang limestone grouting reinforcement project of the floor of coal seam 11 in the Zhaoguan coal mine. The critical grouting pressure of the aquifer is determined to be 14.54 MPa, which guides the smooth implementation of the project.In this work, an HB pencil electrode (HBPE) was electrochemically modified by amino acids (AAs) glycine (GLY) and aspartic acid (ASA) and designated as GLY-HB and ASA-HB electrodes. They were used in the detection of dihydroxybenzene isomers (DHBIs) such as hydroquinone (HQ), catechol (CC), and resorcinol (RS), by cyclic voltammetry (CV), and by differential pulse voltammetry. HBPE was characterized by scanning electron microscopy and energy-dispersive X-ray spectroscopy. These three electrodes showed a linear relationship of current with concentration of DHBIs, and the electrochemical processes were diffusion controlled in all cases. In simultaneous detection, the limit of detection, based on signal-to-noise ratio (S/N = 3), for HQ, CC, and RS was 12.473, 16.132, and 25.25 μM, respectively, at bare HBPE; 5.498, 7.119, and 14.794 μM, respectively, at GLY-HB; and 22.459, 25.478, and 38.303 μM, respectively, at ASA-HB. The sensitivity for HQ, CC, and RS was 470.481, 363.781, and 232.416 μA/mM/cm2, respectively, at bare HBPE; 364.785, 282.712, and 135.560 μA/mM/cm2, respectively, at GLY-HB; and 374.483, 330.108, and 219.574, respectively, at ASA-HB. The interference studies clarified the suitability and reliability of the electrodes for the detection of HQ, CC, and RS in an environmental system. Real sample analysis was done using tap water, and the proposed electrodes expressed recovery with high reproducibility. Meanwhile, these three electrodes have excellent sensitivity and selectivity, which can be used as a promising technique for the detection of DHBIs simultaneously.Nanotechnology advancements and applications have paved the way for new possibilities in regenerative medicine and tissue engineering. It is a relatively new field that has the potential to improve stem cell differentiation and therapy greatly. Numerous studies have demonstrated that nanomaterials can function as a physiological niche for the formation and differentiation of stem cells. However, quantum dots (QDs), such as carbon quantum dots (CQDs) and graphene quantum dots (GQDs), have shown considerable promise in the field of regenerative medicine. To date, most research has focused on stem cell tracking and imaging using CQDs. However, their interaction with stem cells and the associated possibility for differentiation by selectively focusing chemical signals to a particular lineage has received scant attention. In this mini-review, we attempt to categorize a few pathways linked with the role of CQDs in stem cell differentiation.