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Facile fabrication of low cost photocatalyst with enhanced activity and high atomic utilization has been in increasing demand for solar energy usage and/or conversion. In this work, a series of mesoporous carbon nitride nanosheets with enlarged specific surface area were synthesized via an inorganic acid-assisted exfoliation method without any soft or hard templates. Ultralow loading of downsized noble metal Pt was anchored on these porous nanosheets and warranted enhanced photocatalytic activity. The formation of mesoporous nanosheets in carbon nitride was expected to boost mass transfer and shorten charge carrier transfer route during photocatalytic reaction. Characterizations revealed that the enlarged conductivity and photocurrent of carbon nitride nanosheets also contributed to the enhanced H2 evolution. The maximum H2 production rates of 172.92 μmol/h and 321 μmol/h could be achieved over these nanosheets derived from melamine and urea under visible light irradiation, which are 10.92 and 2.22 folds as high as that of corresponding bulk carbon nitride, respectively. This exfoliation method was demonstrated to be an efficient and universal method for the preparation of carbon nitride nanosheets with mesoporous structure and high atomic utilization of co-catalyst for H2 evolution from water.

Shape-stable phase change materials (ss-PCMs) are extensively applied in renewable energy storage. The core for realizing high latent heat and good thermal stability of ss-PCMs is the designation of suitable supporting skeletons that can effectively preserve the PCMs from leaking out. In this study, ss-PCMs impregnated by D-mannitol were prepared using a waste yeast-derived carbon (YC) as the support material. YC possesses a large surface area (669.90 m2/g), which can provide sufficient phase transition space and nucleation sites for D-mannitol. The results indicated that a reduced supercooling of 44.76 °C for YC/D-mannitol ss-PCMs can be realized. The ss-PCMs also exhibited good cycling stability, with latent heat loss rates of 4.00% and 2.15% after 200 thermal cycles. We further demonstrate that YC provides restricted space for mannitol to inhibit the supercooling mechanism. The YC/D-mannitol ss-PCMs exhibited great promise for solar heat storage and industrial waste heat recovery in the medium temperature domain.

This paper aimed to use the major part of carbohydrate fractions in enzymatic hydrolysate of sweet sorghum bagasse, acetone-butanol-ethanol (ABE) fermentation was performed following the ethanol fermentation of hexoses. In batch ethanol fermentation stage, 50.8 ± 3.2 g/L of ethanol was produced from 111.5 g/L of glucose in hydrolysate. After ethanol recovery by batch vacuum distillation, 123.6 ± 15.6 g/L of ethanol was obtained in the distillate, while 47.2 ± 2.5 g/L of xylose was remained in the fermentation broth. The ethanol-free broth was further used as the substrate for ABE fermentation. Compared with yeast remaining scenario, the cell-free ethanol fermentation broth showed a better performance in ABE production. 7.37 ± 0.33 g/L of butanol and 10.93 ± 0.54 g/L of ABE solvent were produced after 120 h of batch fermentation. Based on the biorefinery strategy that cascade two-types of fermentation process, the overall solvents yield boosted significantly, about 144.8 g of ethanol, 17.3 g of butanol and 4.8 g of acetone can be produced from 1 kg sweet sorghum bagasse.

Filtration via a porous medium is a ubiquitous process where high-fidelity physical models are needed. The classical cell model oversimplifies the filtration medium and results in biased and inaccurate predictions of the filter performance. This paper presents the discrete framework of a polydisperse cell model that can incorporate any measured pore size distribution. A new equation connecting the polydisperse cell efficiencies and the medium efficiency is derived from first principles. For ceramic filters, the discrete model demonstrates a generic prediction capability of the filtration efficiency with a root-mean-squared difference of 5.4%, while the counterpart of the classical cell model is 26.4%. In addition, the discrete model eliminates the biased predictions of the classical cell model on sub-100 nm particles.

In order to overcome bottlenecks of the high amount of cellulase consumption in lignocellulosic l -Lactic acid (LA) production, a non-sterilized fed-batch simultaneous saccharification and fermentation (SSF) -membrane separation integration process was established in this current work. During the process, residual cellulase that remaining in the waste aqueous solution and solid residuals of corn stover (CS) were recycled and reused in subsequent fermentations. A total 6 rounds of operation were performed. Averagely, LA yield of 0.389 g g−1 (pretreated CS) was achieved, which was 1.20 times higher than that of the conventional process without waste stream recycling. Moreover, the wastewater discharge and the cost of nutrients for fermentation can also hugely decrease. Results indicated that cellulase, wastewater discharge and nutrients consumption of the process reduced by 47.4 %, 73.7 % and 86.1 %, respectively. This study opens a promising way for the reduction of second-generation LA production cost, which could significantly change the economic feasibility of the LA biorefineries.

This study aimed to investigate the differential effects of remifentanil and sufentanil anesthesia on post-operative pain and recovery of cognitive functions following surgical resection of human colon cancer orthotopically transplanted in rats. Human colon cancer cells HT-29 were used to establish a rat model of orthotopically transplanted colon cancer on to the cecal wall of rats. The transplanted tumors were then surgically removed after 5 weeks, using different doses of remifentanil and sufentanil anesthesia. At 24 h after the surgery, von Frey test, hot plate test and voluntary wheel running test were used to evaluated post-operative pain in the rats. Morris water maze test and fear conditioning test were employed to assess cognitive functions. Serum and colon tissues of the rats were also subjected to ELISA to measure levels of stress response factors, while colon tissues were analyzed by RT-PCR and Western blot to measure expression of inflammation response factors and NF-κB pathway-related factors. Sufentanil showed better effect in reducing post-operative pain, while remifentanil showed better recovery of cognitive functions after surgery. In addition, remifentanil resulted in less stress and inflammation response, caused milder activation of NF-κB pathway-related factors after surgery. Remifentanil and sufentanil exhibited differential effects on post-operative pain and recovery of cognitive function. Specifically, remifentanil caused lower stress and inflammation response, associated with dampened activation of the NF-κB pathway. Our results could provide theoretical basis for adopting appropriate analgesic strategy and agents according to the characteristics of individual patients.

The facile fabrication of low-cost photocatalysts with enhanced activity and high atomic utilization is becoming increasingly necessary for solar energy usage and/or conversion. In this work, a series of mesoporous carbon nitride nanosheets with an enlarged specific surface area was synthesized

Fresh corn stover, which could be separated into fermentable juice and lignocellulosic bagasse, is considered as an alternative raw material for second-generation ethanol production. However, the influence of harvest time of corn stover on ethanol yield has not been evaluated yet. In this work, aiming to improve ethanol yield from fresh corn stover, the harvest time was redefined and optimized. Liquefaction plus simultaneous saccharification and co-fermentation (L + SScF) was carried out to define the realistic ethanol yields. Results showed that compared with the corn stover harvested in the end of physiological stage, the conventional harvest stage, the corn stover harvested in dent stage provided the highest theoretical ethanol yield of 9.92 t/ha (5.64 t/ha for the case that exclude xylan derives). 3.53 t/ha of ethanol was produced from the fresh stover harvested in dent stage, which was 1.64 times higher than using the stover obtained in the conventional harvest time. This study demonstrated that bio-ethanol yield was hugely influenced by harvest time of corn stover, and the stover harvested in dent stage has the highest ethanol yield.

Potassium volatility and activity in a novel K–Ca–Si–O glass catalyst was investigated over extended periods of soot oxidation. Soot was continuously deposited and oxidized by maintaining a glass catalyst-coated filter at temperatures above the oxidation balance point to provide a soot mass equivalent to 100 000 miles of engine operation. Testing revealed the 52-SiO2, 35-K2O, and 13-CaO wt % glass catalysts show a significant improvement in soot oxidation performance over a Pt catalyst. The glass catalyst retains soot oxidation catalytic activity even after testing equivalent to 100 000 miles of use. Migration of potassium in the catalyzed filter from the inlet to the outlet channels was observed. Although potassium was detected on an uncoated downstream core after 50 h of testing, showing that some volatilization of K occurs, the catalyst retains remarkable activity. Surface analysis characterization shows K enrichment of the catalytic glass surface relative to the bulk, which supports the proposed mecha...

Background This study aimed to investigate the effect of preoperative ultrasound-guided stellate ganglion block (SGB) on the perioperative stress responses and gastrointestinal functions of patients undergoing laparoscopic colorectal cancer surgery. Methods A total of 60 colorectal cancer patients were enrolled in study and were randomized to be treated with or without SGB therapy. In the SGB group, patients were injected with 7 mL 0.5% ropivacaine in stellate ganglion under ultrasound guidance before anesthesia. Mean artery pressure (MAP), heart rate (HR), recovery of bowel sound and first exhaust, as well as levels of motilin, gastrin, norepinephrine, cortisol, interleukin-6 (IL-6) and C-reactive protein (CRP) were recorded at various time points. Results 26 patients in the SGB group and 27 patients in the control group were analyzed. No significant differences in MAP or HR were observed between the two groups before, during and after the surgery. SGB promoted recovery of gastrointestinal functions, as evidenced by earlier recovery of bowel sound and first exhaust, as well as increased motilin and gastrin levels. SGB also attenuated stress responses, as shown in reduced norepinephrine, cortisol, IL-6 and CRP levels. Conclusions SGB promotes the recovery of gastrointestinal functions and reduces stress responses of colorectal patients undergoing laparoscopic colorectal cancer surgery.

To reduce the butanol fermentation wastewater (BFW) discharge and to address the difficulties in BFW treatment, a novel fermentation–pervaporation hybrid process was performed. After each batch of acetone–butanol–ethanol (ABE) fermentation, ABE in the fermentation broth was ex situ separated by pervaporation. The retentate was used as the buffer and the solution for the following batches of enzymatic hydrolysis and fermentation, respectively. Results showed that there were little negative influences of the phenols and acid inhibitors on the fermentation performances using the recycled BFW. Benefits from the process for BFW discharge reduction were obvious. After 4 cycles of BFW, ∼86% of the BFW was saved. Over 94% of ABE with concentrations of 42.5–50.2 g/L was recovered by pervaporation. Therefore, the novel process can effectively eliminate the disadvantage of large BFW discharge in the ABE fermentation processes.

K-containing soot oxidation catalysts are promising to reduce or replace noble metal usage in combustion engine emission abatement systems. In this paper, we introduce a facile approach for applying a K-containing glass catalyst onto structured wire mesh monoliths to achieve low temperature soot removal. A polyvinyl butyral (PVB) modified sol-gel process was developed to yield a crack-free thickness that is 6 times that of the conventional sol-gel process. An intermediate SiO2 barrier layer was found to be effective to insure stability of the glass catalyst over extended cycling periods. The catalytically coated wire mesh can lower the soot ignition temperature (Tig) to ∼370 °C with O2, and offers catalytic stability for long term combustion cycling.

The fabrication of noble-metal-free and low-cost photocatalysts with high efficiency has been under increasing demand for solar energy usage and conversion. In this work, a series of surface-modified Ni/graphitic carbon nitride (g-C3N4) photocatalysts derived from metal–organic frameworks (MOFs) were synthesized by the in situ pyrolysis of Ni-based benzenedicarboxylic acid Ni2(BDC)2 in the presence of graphitic carbon nitride under Ar protection. The as-prepared samples displayed highly efficient H2 evolution under visible-light irradiation, with a maximum H2 production rate of 2989.5 μmol g−1 h−1, which was about 22.1 times higher than the value of carbon nitride (135.2 μmol g−1 h−1). This exceptionally enhanced photocatalytic activity originated from the tight bonding between the Ni-based cocatalyst and g-C3N4 as well as fast and efficient electron transfer with the help of conductive carbon loaded on the surface of the Ni species during Ni2(BDC)2 pyrolysis.

With ever-tightening emission regulations, particulate filters are critical for internal combustion engines to meet the stringent particulate matter emission standards. A fast way to predict the filter performance, instead of numerically solving the governing differential equations, is needed for filter design and selection, real-time control, malfunction detection, and deposit load sensing. Approximate analytical solutions for wall flow filters, considering asymmetric channels and arbitrary deposit amounts, are derived by a technique of successive approximation. The analytical predictions of filter pressure drop have been validated against both steady state and transient experimental measurements. Moreover, over a broad range of filter operating conditions, the accuracy of the second-order analytical solution is validated by comparisons with the numerical predictions. The derivation also provides analytical expressions for channel and wall velocity profiles along the filter length. This study reveals the...

The hydrothermal stability of K-Ca-Si-O glass soot oxidation catalysts has been improved by substitution of Ce and Zr for Ca. This work demonstrates that glasses can be tailored to withstand the challenging diesel exhaust hydrothermal environment by considering the field strengths and partial molar free energies of the hydration reactions (&Delta, Gi) of the cation species in the glass. The result is a glass that shows less formation of precipitates after 2 h hydrothermal exposure in air with 7% H2O at temperatures ranging from 300&ndash, 700 &deg, C. A K-Ca-Si-O glass with a soot T50 (the temperature when 50% of the soot is oxidized) of 394 &deg, C was found to degrade to 468 &deg, C after a 2 h, 700 &deg, C hydrothermal exposure, whereas the improved K-Ce-Zr-Si-O glass only changed from 407 &deg, C to 427 &deg, C after the same treatment.

Cu-SSZ-13 catalysts have been widely used for NOx reduction via SCR for diesel aftertreatment applications due to their high SCR efficiency. Hydrothermal aging and sulfur poisoning are two areas of research on Cu-SSZ-13 catalysts due to their significant relevance to real world applications. In addition to the effects of 650 °C hydrothermal aging, this work also investigates the corresponding sulfur poisoning effects upon aging. Hydrothermal aging results in decreasing SCR reactivity with constant activation energy. Upon sulfation at 400 °C, the catalyst displays decreasing SCR reactivity with lower activation energy. However, upon longer aging duration prior to sulfation, the decrease in SCR reactivity becomes less and the catalyst becomes more resistant toward sulfur poisoning with less sulfur loading. The enhanced sulfur poisoning resistance of Cu-SSZ-13 catalyst can be mainly ascribed to the gradual conversion of ZCuOH to Z2Cu upon aging as suggested by results from NH3 TPD and DRIFTS.

Engine particulate filters have been widely applied across the world to control engine exhaust particulate matter (or particulate number) emissions. With increasing vehicle mileage, ash accumulation deteriorates vehicle fuel economy and complicates on-board control. Extending filter service life with ash loading has significant economic and environmental impacts. Many studies have been conducted in characterizing ash accumulation and evaluating its impacts on filter performance. However, comprehensive reviews covering all the key issues in the field are rather rare. This paper reviews the extensive prior research on filter ash, and not only summarizes the experimental observations but also elucidates the fundamental mechanisms. The review covers the areas of ash origin, accumulation, transport, evolution, and artificial acceleration methods. The previously reported data of ash properties is compiled and analyzed. The advantages and disadvantages of ash acceleration approaches are also discussed in detail. Based on the cumulative understanding, a few potential ways to improve ash management are discussed in this paper. In short, the present work systematically reviews the previous observations and understanding of ash aging in particulate filters and identifies areas that need further research, which can be useful guidance for future studies.

The nanocomposite preparation procedure plays an important role in achieving a well-established heterostructured junction, and hence, an optimized photocatalytic activity. In this study, a series of g-C3N4/ZnO nanocomposites were prepared through two distinct procedures of a low-cost, environmentally-friendly, in-situ fabrication process, with urea and zinc acetate being the only precursor materials. The physicochemical properties of synthesized g-C3N4/ZnO composites were mainly characterized by XRD, UV–VIS diffuse reflectance spectroscopy (DRS), N2 adsorption-desorption, FTIR, TEM, and SEM. These nanocomposites’ photocatalytic properties were evaluated in methylene blue (MB) dye photodecomposition under UV and sunlight irradiation. Interestingly, compared with ZnO nanorods, g-C3N4/ZnO nanocomposites (x:1, obtained from urea and ZnO nanorods) exhibited weak photocatalytic activity likely due to a “shading effect”, while nanocomposites (x:1 CN, made from g-C3N4 and zinc acetate) showed enhanced photocatalytic activity that can be ascribed to the effective establishment of heterojunctions. A kinetics study showed that a maximum reaction rate constant of 0.1862 min-1 can be achieved under solar light illumination, which is two times higher than that of bare ZnO nanorods. The photocatalytic mechanism was revealed by determining reactive species through adding a series of scavengers. It suggested that reactive ●O2− and h+ radicals played a major role in promoting dye photodegradation.