A CO2‐mediated hydrogen storage energy cycle is a promising way to implement a hydrogen economy, but the exploration of efficient catalysts to achieve this process remains challenging. Herein, ...sub‐nanometer Pd–Mn clusters were encaged within silicalite‐1 (S‐1) zeolites by a ligand‐protected method under direct hydrothermal conditions. The obtained zeolite‐encaged metallic nanocatalysts exhibited extraordinary catalytic activity and durability in both CO2 hydrogenation into formate and formic acid (FA) dehydrogenation back to CO2 and hydrogen. Thanks to the formation of ultrasmall metal clusters and the synergic effect of bimetallic components, the PdMn0.6@S‐1 catalyst afforded a formate generation rate of 2151 molformate molPd−1 h−1 at 353 K, and an initial turnover frequency of 6860 molH2
molPd−1 h−1 for CO‐free FA decomposition at 333 K without any additive. Both values represent the top levels among state‐of‐the‐art heterogeneous catalysts under similar conditions. This work demonstrates that zeolite‐encaged metallic catalysts hold great promise to realize CO2‐mediated hydrogen energy cycles in the future that feature fast charge and release kinetics.
Sub‐nanometer Pd–Mn clusters were encaged within silicalite‐1 zeolites by a ligand‐protected method under direct hydrothermal conditions. The obtained zeolite‐encaged metallic nanocatalysts exhibited a record formate generation rate of 2151 molformate molPd−1 h−1 at 353 K, and an excellent initial turnover frequency of 6860 molH2
molPd−1 h−1 for CO‐free formic acid decomposition at 333 K without any additive.
Electrostatics of granules and granular flows: A review Zhao, Yanlin; Liu, Min; Wang, Chi-Hwa ...
Advanced powder technology : the international journal of the Society of Powder Technology, Japan,
January 2023, 2023-01-00, Letnik:
34, Številka:
1
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•A review of electrostatics of granules and granular flows.•Granule-wall collision causes electrification.•Work function plays a significant role in granule charging.•Granule charging ...progress is usually influenced by many factors.•The electrostatics of granules and granular flows will develop as interdisciplinary issues with other subjects.
In past decades, the electrostatics of granules and granular flows has obtained more and more attention due to many industrial problems and the associated development of new technologies. Granule-wall collision causes electrification, where charge transfer can be characterized by work function, electron transfer, ion transfer, and material transfer. Electrification is affected by many factors and increases with granule processing, and the charge amount can reach a saturated state where electrification no longer increases, which has been confirmed by single granule and granule conveying systems. In addition, the presence of electrostatic charges has profound influences in relevant areas, including chemistry, chemical engineering, energy, pharmaceuticals, and so on. The measurement technology of electrostatics used in granule conveying systems has been improved with the continuous progress of industry. Furthermore, electrostatics of granules and granular flows will be developed into a more accurate area together with other subjects as an interdisciplinary problem to be concerned. In addition, in the pneumatic conveying system, granule-wall and granule-granule collision or friction can cause material transfer due to material breakage. The working mechanism of the material transfer due to collision or friction has never been fully understood. Such problems will be solved gradually in the future.
To investigate maximum tolerated dose (MTD) of axitinib, a selective vascular endothelial growth factor receptor 1-3 inhibitor, in combination with radiotherapy (RT) for advanced hepatocellular ...carcinoma (HCC).
This phase I study followed the rule of traditional 3 + 3 design. Major eligibility included: (1) patients with advanced HCC unsuitable for surgery, radiofrequency ablation or transarterial chemoembolization, or who failed after prior local-regional treatment; (2) failure on sorafenib or no grant for sorafenib from health insurance system. Eligible patients with advanced HCC received axitinib for total 8 weeks during and after RT. Three cohorts with axitinib dose escalation were planned: 1 mg twice daily (level I), 2 mg twice daily (level II) and 3 mg twice daily (level III). The prescribed doses of RT ranged from 37.5 to 67.5 Gy in 15 fractions to liver tumor(s) and were determined based on an upper limit of mean liver dose of 18 Gy (intended isotoxic RT for normal liver). The primary endpoint was MTD of axitinib in combination with RT. The secondary endpoints included overall response rate (ORR), RT in-field response rate, acute and late toxicities, overall survival (OS) and progression free survival (PFS).
Total nine eligible patients received axitinib dose levels of 1 mg twice daily (n = 3), 2 mg twice daily (n = 3) and 3 mg twice daily (n = 3). Dose-limiting toxicity (DLT) did not occur in the 3 cohorts; the MTD was defined as 3 mg twice daily in this study. ORR was 66.7%, including 3 complete responses and 3 partial responses, at 3 months after treatment initiation. With a median follow-up of 16.6 months, median OS was not reached, 1-year OS was 66.7%, and median PFS was 7.4 months.
Axitinib in combination with RT for advanced HCC was well tolerated with an axitinib MTD of 3 mg twice daily in this study. The outcome analysis should be interpreted with caution due to the small total cohort. Trial registration ClinicalTrials.gov (Identifier: NCT02814461), Registered June 27, 2016-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT02814461.
A bisindole-bridged-porphyrin tweezer (1), a pair of zinc porphyrins (P Zn ’s) connected to bisindole bridge (BB) via the CuI-mediated alkyne–azide click chemistry, exhibited unique switching in ...forward and backward photoinduced energy transfer by specific guest bindings. The addition of Cu2+ caused a change in electronic absorption and fluorescence quenching of 1. MALDI-TOF-MS and FT-IR analyses indicated the formation of stable coordination complex between 1 and Cu2+ (1-Cu(II)). Without Cu2+ coordination, the excitation energy flows from BB to P Zn ’s with significantly high energy transfer efficiency. In contrast, the direction of energy flow in 1 was completely reversed by the coordination of Cu2+. The difference in fluorescence quantum yield between 1 and 1-Cu(II) indicates that more than 95% of excitation energy of P Zn flows into Cu(II)-coordinated BB. The energy transfer efficiency was further controlled by bidentate ligand coordination onto 1-Cu(II). When pyrophosphate ion was added to 1-Cu(II), the recovery of fluorescence emission from P Zn was observed. The quantum mechanical calculations indicated that the Cu(II)-coordinated BB has square planar geometry, which can be distorted to form octahedral geometry due to the coordination of bidentate ligands.
Bio-heavy oil (BHO), a crude mixture of fatty acids (FAs) and mono-, di-, and triglycerides unavoidably generated as waste during biodiesel production processes, is an alternative replacement of ...petro-heavy oil as a fuel for power generation. It is reported for the first time that upgrading the quality of raw BHO (lowering the acid value (AV) of BHO) can be achieved via a low-pressure non-catalytic esterification process. Esterification of the FAs contained in raw BHO on solid acid catalysts (tungsten trioxide and niobium pentoxide) were investigated by comparison with the non-catalytic method. The AV of raw BHO can be successfully reduced from 116 to ∼38 in 2 h under a low pressure (0.1 bar) via the non-catalytic esterification process. Catalytic esterification with Nb2O5 or WO3 showed similar performance to the non-catalytic esterification. It can be suggested a possibility to make a high-quality renewable fuel (e.g., BHO with a low acid value) for power generation from inexpensive feedstock.
In this study, the conversion of fat, oil and grease (FOG) into fatty acid methyl esters (FAMEs) without pre-treatment of FOG is investigated. A thermally induced process to accomplish simultaneous ...esterification of free fatty acids (FFAs) and transesterification of lipids is introduced. Despite high contents of impurities in FOG (∼14 wt%), the maximum achievable yield of FAMEs on feedstock mass basis was >86% for 10 s reaction time without removal of impurities prior to the reaction while conventional acid catalyzed reaction only produced <27.7% FAMEs from FOG. This means that the introduced technique can be effective for the conversion of low-quality raw material (e.g., FOG) into biodiesel. This study would suggest the potential not only for developing a sustainable integrated treatment process of FOG requiring no separation of lipids and FFAs in wastewater treatment facilities but also for using FOG as a renewable energy resource.
•FOG contains high contents of free fatty acids (∼14 wt.%).•FAMEs from FOG via thermally induced simultaneous esterification/transesterification.•>86% total FAME yield from FOG on feed mass basis with no pre-treatment of FOG.
A positive bias temperature instability (PBTI) recovery transient technique is presented to investigate trap properties in HfSiON as high-k gate dielectric in nMOSFETs. Both large- and small-area ...nMOSFETs are characterized. In a large-area device, the post-PBTI drain current exhibits a recovery transient and follows logarithmic time dependence. In a small-area device, individual trapped electron emission from HfSiON gate dielectric, which is manifested by a staircase-like drain current evolution with time, is observed during recovery. By measuring the temperature and gate voltage dependence of trapped electron emission times, the physical mechanism for PBTI recovery is developed. An analytical model based on thermally assisted tunneling can successfully reproduce measured transient characteristics. In addition, HfSiON trap properties, such as trap density and activation energy, are characterized by this method.
The Taylor–Couette bioreactor used in this study was demonstrated to achieve increased cell proliferation rate and the better cell distribution in the porous biodegradable scaffolds. The high mass ...transfer rate of oxygen and nutrient provided by the Taylor vortex could also improve the yield of desired product of PEX protein.
•We produced the anti-tumor PEX protein by transfected QM7 cells in a Taylor–Couette bioreactor.•The yield of PEX protein could be increased about 30 times as compared with control.•The 3D cell culture was achieved in the porous scaffold.•The cells grow well in the Taylor–Couette device without sparging due to sufficient oxygen provided by the bioreactor.
In recent decades, many practical applications were developed with regard to the Taylor–Couette device, for example, reaction, filtration, extraction and bioreactor. In this study, the Taylor–Couette bioreactor was used to culture cells seeded in a biodegradable porous scaffold and produce PEX protein. Two different cell lines (NIH/3T3 and QM7) were seeded into PLGA sponges, which were fabricated using a solvent-free supercritical gas foaming method, and then cultured in the Taylor–Couette bioreactor. Cell proliferation was characterized using Quant-iT™ PicoGreen® dsDNA assay and the results indicated that high mass transfer rate in the Taylor–Couette bioreactor enhanced cell proliferation. Qualitative distribution of live/dead cells was characterized using LIVE/DEAD® Viability/Cytotoxicity assay and SEM and the results showed that cells cultured in static control mainly proliferated on the outer surface while the cells of Taylor-vortex bioreactor group could penetrate into the scaffold. The production yield of PEX protein, from QM7 cells transfected with pM9PEX, was quantified using PEX ELISA and the results showed a much higher PEX mass per scaffold for bioreactor than the control. As such, there is potential for the use of Taylor–Couette bioreactor in the mass production of PEX protein.
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