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A new tomato juice concentration technology using CO2 hydrate formation is presented. The CO2 hydrate equilibrium conditions were measured by the isochoric pressure search method and tomato juice concentration experiments were carried out in a high-pressure stirred reactor. Moreover, the dehydration ratio was defined and CO2 hydrate formation rate constants were calculated with different feed pressures. The effects of feed pressure, temperature, and juice volume on the dehydration ratio were investigated. The results show that the tomato juice used in this work has almost no effect on CO2 hydrate phase equilibrium conditions, but can accelerate CO2 hydrate formation. The dehydration ratio increased with increasing the feed pressure from 1.81 to 3.95 MPa; the maximum dehydration ratio reached 63.2% at a feed pressure of 3.95 MPa, and the optimum tomato juice volume was 80 mL. These results demonstrated that removal of water with the help of CO2 hydrate is an efficient technology for tomato juice concentration. [ABSTRACT FROM AUTHOR]

Classic fluorescent dyes, such as coumarin, naphthalimide, fluorescein, BODIPY, rhodamine, and cyanines, are cornerstones of various spectroscopic and microscopic methods, which hold a prominent position in biological studies. We recently found that 9-amino-benzo[c]cinnoliniums make up a novel group of fluorophores that can be used in biological studies. They are featured with a succinct conjugative push-pull backbone, a broad absorption band, and a large Stokes shift. They are potentially useful as a small-molecule alternative to R-phycoerythrin to pair with fluorescein in multiplexing applications. [ABSTRACT FROM AUTHOR]

Nitrite is a heavily assayed substrate in the fields of food safety, water quality control, disease diagnosis, and forensic investigation and more recently in basic biological studies on nitric oxide physiology and pathology. The colorimetric Griess assay and the fluorimetric 2,3-diaminonaphthalene (DAN) assay are the current gold standards for nitrite quantification. They are not without limitations, yet have amazingly survived 156 and 44 years, respectively, due to the lack of a practical alternative. Both assays exhibit slow detection kinetics due to inactivation of nucleophiles under strongly acidic media, require an extensive incubation time for reaction to go completion, and hence offer a limited detection throughput. By converting an intermolecular reaction of the Griess assay intramolecularly, we designed a novel probe (NT555) for nitrite detection, which displays superior detection kinetics and sensitivity. NT555 was constructed following our "covalent-assembly" probe design principle. Upon detection, it affords a gigantic bathochromic shift of the absorption spectrum and a sensitive turn-on fluorescence signal from a zero background, both of which are typical of an "assembly" type probe. Overall, NT555 has addressed various difficulties associated with the Griess and the DAN assays and represents an attractive alternative for practical applications. [ABSTRACT FROM AUTHOR]

A novel separation process was developed for orange juice concentration via CO2 hydrate formation. The CO2 hydrate equilibrium conditions were measured by an isochoric pressure search method. The effects of feed pressure, temperature, juice volume, and stirring speed on dehydration ratio were investigated. The dehydration ratio increased with increasing the feed pressure; the maximum dehydration ratio of 57.2% was reached at feed pressure of 4.10 MPa; dehydration ratio maintained around 45.8% in the temperature range of 274.8-279.8 K; the optimum orange juice volume is 80 mL. The CO2 hydrate formation rate constants increased from 0.67 x 10-8 to 1.91 x 10-8 mol2/(s J) in relation to the feed pressure increasing from 1.96 to 4.10 MPa. The results demonstrated that removal of water by formation of CO2 hydrate is an efficient technology for orange juice concentration. [ABSTRACT FROM AUTHOR]

Vapour phase tert-butylation of toluene with tert-butylalcohol was studied over ultra-stable Y zeolite (USY) catalyst. The effects of reaction temperature, toluene/TBA molar ratio and liquid space velocity on conversion of toluene and selectivity for 4-tert-butyltoluene were studied. The deactivation and regeneration of the catalyst was also investigated. The results showed that the USY zeolite catalyst offered better toluene conversion of about 30% and 4-tert-butyltoluene selectivity of about 89% at the suitable reaction condition as follows: reaction temperature of 120 °C, toluene/TBA ratio of 2:1 and liquid space velocity of 2 ml/g•h. The clogging of micropores by the formed carbon or oligomers was the main reason for the deactivation of the catalyst. By combustion at 550 °C, the catalyst just lost about 5% in toluene conversion and about 2% in para-tert-butyltoluene (PTBT) selectivity. [ABSTRACT FROM AUTHOR]

Controlled release formulations have been shown to have potential in overcoming the drawbacks of conventional plant growth regulators formulations. A controlled-release formulation of 1-naphthylacetic acid (NAA) and indole-3-butyric acid (IBA) simultaneous intercalated MgAl-layered double hydroxides (LDHs) was prepared. The synthetic nanohybrid material was characterized by various techniques, and release kinetics was studied. NAA and IBA anions located in the gallery of MgAl-LDHs with bilayer arrangement, and the nanohybrids particles were of typical plate-like shape with the lateral size of 50-100 nm. The results revealed that NAA and IBA have been intercalated into the interlayer spaces of MgAl-LDHs. The release of NAA and IBA fits pseudo-second-order model and is dependent on temperature, pH value, and release medium. The nanohybrids of NAA and IBA simultaneously intercalated in LDHs possessed good controlled release properties. [ABSTRACT FROM AUTHOR]

Accurate travel time prediction allows passengers to schedule their journeys efficiently. However, cyclical factors (time intervals of the day, weather conditions, and holidays), unpredictable factors (incidents, abnormal weather), and other complicated factors (dynamic traffic conditions, dwell times, and variation in travel demand) make accurate bus travel time prediction complicated. This paper aims to achieve accurate travel time prediction. To do so, we propose a clustering method that identifies travel time paradigms of different route links and clusters them based on their similarity using the nonnegative matrix factorization algorithm. Additionally, we propose a deep learning model based on CNN with spatial–temporal attention and gating mechanisms to select the most relevant features and capture their dependencies and correlations. For each defined cluster, we train a separate model to predict the travel time at various time intervals over the day. As a result, the travel times of all journey links from related prediction models are aggregated to predict the total journey time. Extensive experiments using data collected from four different bus lines in Beijing show that our method outperforms the compared baselines. [ABSTRACT FROM AUTHOR]

The ZSM-5, γ-Al2O3, SiO2 and MgO supported Pd-catalysts were prepared for the phenol hydrogenation to cyclohexanone in liquid-phase. The natures of these catalysts were characterized by XRD, N22 adsorption-desorption analysis, H2-TPR, CO2-TPD and NH3-TPD. The catalytic performance of the supported Pd-catalyst for phenol hydrogenation to cyclohexanone is closely related to nature of the support and the size of Pd nanoparticles. The Pd/MgO catalyst which possesses higher basicity shows higher cyclohexanone selectivity, but lower phenol conversion owing to the lower specific surface area. The Pd/SiO2 catalyst prepared by precipitation gives higher cyclohexanone selectivity and phenol conversion, due to the moderate amount of Lewis acidic sites, and the smaller size and higher dispersion of Pd nanoparticles on the surface. Under the reaction temperature of 135 °C and H2 pressure of 1 MPa, after reacting for 3.5 h, the phenol conversion of 71.62% and the cyclohexanone selectivity of 90.77% can be obtained over 0.5 wt% Pd/SiO2 catalyst. [ABSTRACT FROM AUTHOR]

Co-doped ZnAl layered double hydroxides (LDH) were papered by coprecipitation. The prepared samples were characterized by multiple techniques including X-ray Diffraction (XRD), Brunauer- Emmett-Teller (BET) surface area, Scanning Electronic Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS) and UV-Vis Diffuse-Reflectance Spectroscopy (UV-Vis DRS). The incorporation of Co2+ into the ZnAl LDH sheets as CrO6 octahedron forms a new energy level which contributes for the excitation of electrons under visible light. The doped Co2+ at a reasonable content also serves as photo-generated charges separator and improves the visible light photocatalytic activity of ZnAl LDH. A degradation mechanism based on the hydroxyl radical as the active species was proposed. [ABSTRACT FROM AUTHOR]

Mg-Al layered double hydroxides (LDHs) adsorbent was synthesized in situ on γ-Al2O3 for the removal of Cr(VI) from aqueous solution. The material was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electronic microscopy and thermogravimetry and differential thermal analysis. Compared to the LDHs powder, the calcined LDHs sorbent prepared in situ on γ-Al2O3 had higher specific surface area and was easy to recover and reuse. The adsorptive capacity for removing Cr(VI) from aqueous solution was resulting from the memory effect of LDHs based on the XRD results. Both the pseudo-second-order kinetic model and the Langmuir model fit the experimental data well. Furthermore, the adsorbent exhibits excellent sorption-regeneration performances. [ABSTRACT FROM AUTHOR]