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Efficient purification of oily sewage, recycling, and standard discharge have become key issues for the sustainable development of oil fields. In this study, the surface of PPFS was organically modified by a silane coupling agent. Then, covalently bonded cationic block inorganic-organic composite coagulant was prepared by chosen sodium polyacrylate as the template. This unique structure significantly enhances the positive charge and molecular chain length of the coagulant, thus improving its ability to perform charge neutralisation, adsorption bridging, and sweep coagulation. The characteristic functional groups and thermophysical properties of the composite coagulant were analysed by FTIR and thermogravimetric analysis. The transformation of random copolymers to block copolymers was determined by 1 H NMR, thus confirming the successful synthesis of the cationic block structures. The turbidity removal and oil removal properties of oily sewage were investigated by coagulation experiment. The Zeta potential, dynamic and static light scattering, and field emission scanning electron microscopy (SEM) were used to study the effect of composite coagulants on the microscopic morphology and coagulation of flocs. Finally, the coagulation mechanism of the compound coagulant was analyzed with the dynamic change of the particle size of the flocs. The cationic block structure in TP(AM-DAC-PPFS) can effectively neutralise the negative charges on the surface of impurity particles and emulsified oil. The optimal dosage of TP(AM-DAC-PPFS) was 30 mg·L−1, at which the turbidity and oil removal rates can reach 98.3% and 93.8%, respectively. [Display omitted] • The covalently linked composite coagulant TP(AM-DAC-PPFS) was successfully prepared. • The cationic block structure increases the coagulation capacity and avoids polymer agglomeration. • The organic molecular chain destroys the structure of the emulsified oil droplets. • Coagulation mechanism of charge neutralization, adsorption bridging and sweeping is improved synergistically [ABSTRACT FROM AUTHOR]

• PPFS-PAD-RGO compound coagulants were successfully prepared. • The coagulability of PPFS-PAD-RGO has been enhanced. • PPFS-PAD-RGO has certain demulsification ability. • The oil content of oily sludge is reduced. During oil extraction, a substantial volume of oily sewage (water-in-oil emulsion) is generated. The existence of emulsified oil diminishes the effectiveness of conventional coagulants used for purification. Furthermore, coagulants frequently precipitate emulsified oil as impurities, leading to resource wastage. Hence, there is an urgent need to develop multifunctional coagulation/demulsification agents that are environmentally safe. In this study, we synthesized the branched-chain compound coagulant (PPFS-PAD-RGO) and investigated its coagulation and demulsification properties. The results of dynamic and static light scattering and FTIR show that chitosan grafted onto the surface of modified PPFS forms a dendritic flocculation system. In addition, PPFS-PAD is fixed to a reduced graphene oxide carrier with a high specific surface area, which improves the positive charge density and dispersion of the coagulant. The layered structure amplifies the effect of adsorption bridge formation and net aggregation. At a concentration of 80 mg/L, PPFS-PAD-RGO exhibited a turbidity removal rate of 96.15 % and demulsification rate of 74 %. By comparing the structure of PPFS, it was found that the floc volume of PPFS-PAD-RGO is larger. This demulsification ability is mainly attributed to an amine matrix in the chitosan extension chain, which destroys the oil–water interface of the oil-in-water emulsion and induces demulsification. The introduction of RGO increases the local concentration of coagulant molecules. Therefore, the coagulation effect of PPFS-PAD-RGO in oily sewage is attributed to the introduction of demulsifier groups and nanomaterials, which strengthen the synergistic effect of charge neutralization, bridge adsorption and sweeping. [ABSTRACT FROM AUTHOR]

• A method of gravity coagulation was proposed. • The covalently linked coagulant microcapsules was successfully prepared. • The coagulant capsule has able to release its contents slowly upon water impact. • The mechanism of The coagulant capsule was studied. If untreated, oilfield sewage generated during the oil exploitation process can lead to severe environmental pollution. The coagulation/flocculation process plays a pivotal role in the comprehensive treatment of oilfield sewage on a large scale, yet traditional methods exhibit significant limitations. To address the disparity between laboratory experiments and large-scale implementation, this study introduces an innovative coagulant microcapsule. Prepared under gentle conditions, these microcapsules effectively eliminate colloidal particles from water when introduced at the coagulation tank inlet. Featuring a core–shell structure, coagulant microcapsules demonstrate controlled content release upon contact with water. The coagulation process occurs as sewage enters the coagulation tank. The core of the coagulant microcapsule consists of the inorganic polymer coagulant (PASS-C16) with hydrophobic association capabilities. Upon contact with sewage at a specific flow rate, the coagulant is released gradually from the microcapsule. Upon reaching the bottom of the coagulation pool, the coagulant comes into full contact with colloidal particles, influenced by gravity. Ultimately, through integration with Fluent simulation and analysis of floc particle size changes, it was determined that the primary mechanisms of coagulant capsules in aquatic conditions involve charge neutralization and bridging adsorption. The sweeping action is effective only when the test water tends to be static. This technology is viable for application in the coagulation sedimentation tanks of diverse sewage treatment plants. Gravity coagulation demonstrates potential as a replacement for conventional mechanical mixing methods, offering increased efficiency and potential energy savings in various water treatment processes. [ABSTRACT FROM AUTHOR]

The CO 2 capture and separation performances are enhanced by improving structural polarity and providing CO 2 adsorption sites through introduced functional groups and Li. There is a synergistic effect between these modifications in improving performances. Notably, TpPa-SO 3 Li demonstrates the highest CO 2 capture capacity of 136.11 cm3 cm−3, along with the CO 2 over N 2 /CH 4 selectivity of 264.22/164.38, respectively. [Display omitted] • CO 2 capture and separation performances are evaluated in TpPa COFs modified by functional group and Li using GCMC and DFT. • There is a synergistic effect between functional groups and metal Li in enhancing the selective CO 2 capture performance. • TpPa-SO 3 Li exhibits the best CO 2 capture capacity of 136.11 cm3 cm−3 with the CO 2 over N 2 /CH 4 selectivity of 264.22/164.38, respectively. • Improved structural polarity and additional metal adsorption sites are the main reasons for optimized performances. Covalent organic frameworks (COFs) have emerged as promising materials for CO 2 capture and separation owing to their exceptional structural stability. Herein, grand canonical Monte Carlo simulation (GCMC) and density functional theory (DFT) were used to first screen the most favorable functional group in the COFs consisting of 1,3,5-triformylphloroglucinol (Tp) and p-phenylenediamine (Pa) functionalized with –OH, –COOH, and –SO 3 H, respectively (TpPa-X). Subsequently, the H atoms of –SO 3 H, the best functional group, were replaced by Li atoms to form –SO 3 Li, revealing the synergies of functional group –SO 3 H and Li modification on selective CO 2 capture. TpPa-OLi/COOLi were also constructed to confirmed the universality of this synergistic effect. The introduction of functional groups enhanced the CO 2 capture and separation performances by creating a more suitable pore environment. The Li introduction increased the structural polarity and provided strong adsorption sites, further improving the selective CO 2 capture performance. Notably, TpPa-SO 3 Li exhibited a remarkable CO 2 adsorption capacity of 136.11 cm3 cm−3 with the CO 2 over N 2 /CH 4 selectivity of 264.22/164.38, respectively, at 298 K and 1.0 bar. Structural stabilities, pore characteristics, gas adsorption distribution, isothermal adsorption heat, and interactions were adopted to reveal the synergistic effect between functional groups and Li in enhancing CO 2 capture and separation. [ABSTRACT FROM AUTHOR]

The CO 2 capture and separation performance is enhanced by the improved structural polarity and additional adsorption sites created by anchoring alkali metal Li/Na/K. And the increase shows a positive correlation with AM concentration. Specially, UPC-6Li presents the best CO 2 capture capacity of 221.64 cm3 cm−3, along with the CO 2 over N 2 /CH 4 selectivity of 308/206, among UPC-AMs. [Display omitted] • CO 2 capture and separation performance were evaluated in 2D-COFs anchored by different concentration alkali metal (Li, Na, and K). • UPC-6Li exhibited the best CO 2 capture capacity of 221.64 cm3 cm−3 and CO 2 over N 2 /CH 4 selectivity of 308/206. • Improved structural polarity and additional metal adsorption sites are the main reasons for optimized performance. The development of advanced adsorbents with high CO 2 capture and separation performances is essential for decreasing atmospheric CO 2 concentration. Herein, grand canonical Monte Carlo and density functional theory were employed to investigate the adsorption and separation properties of CO 2 , N 2 , and CH 4 in 2D covalent organic framework (COFs) anchored by alkali metal (AMs) Li, Na, and K (UPC-nAMs, n = 3 or 6) at 298 K and 0–1.0 bar. The anchoring of AMs formed favorable adsorption sites, endowing UPC-nAMs with better CO 2 capture and separation performances. This effect was more evident with an increase in Li/Na/K concentration. The CO 2 adsorption capacity of UPC-6Li/Na/K was ∼ 221.64, 188.28, and 140.50 cm3 cm−3. The smaller atomic size of Li occupied less adsorption space, resulting in the highest CO 2 capture capacity of 221.64 cm3 cm−3 with selectivity of 308/206 over N 2 /CH 4 in UPC-6Li at 298 K and 1.0 bar. Structural stability, pore characteristics, isothermal adsorption heat, van der Waals and Coulomb interactions, gas distribution density, adsorption configuration, and gas radial distribution function were analyzed to identify the intrinsic mechanism of anchoring Li/Na/K to improve CO 2 capture and separation performances. [ABSTRACT FROM AUTHOR]

Natural rubber is a key agro-industrial product in Asia, Africa, America, and Oceania, with widespread applications (e.g. tires, latex gloves, wet suits). The energy consumption of the traditional rubber drying process is very high and improvements should be investigated to both reduce the energy consumption, and reduce the cost of the rubber processing. The research investigated both heat recovery and solar air heating (SAH) to minimize the energy consumption of the drying process. A complete assessment of an industrial rubber drying plant in China demonstrated that a heat recovery can reduce the energy consumption by 16 to 44%. If moreover SAH is applied, further energy savings can be achieved. A pilot-scale SAH was tested. Its solar transfer efficiency was between 30% and 50%. Experimental data were theoretically validated, and used in a scale-up design strategy, resulting in an overall drying energy saving of 60 to 77%. The corresponding total investment and payback period are 300 and 420 k€ and 2 to 3.3 years respectively. The novel layout of the energy-efficient rubber dryer, and its energy performance are illustrated. [Display omitted] • Natural rubber is a key agro-industrial product. • The energy consumption for rubber drying is very high. • Energy savings are achieved by integrated heat recovery. • Solar air heating can further reduce the energy consumption. • A total saving on drying energy of 60 to 77% is achieved. [ABSTRACT FROM AUTHOR]

• The octopus tentacle-like composite coagulant was prepared. • This special structure can improve performance of the coagulant. • Destabilizing O/W emulsified oil droplets. • The treated sewage meets the reinjection standard. The complexity of oily sewage from oilfields has risen with the advancement of polymer flooding technology, thereby increasing the treatment challenge. In this study, a composite coagulant, PVPAM-PPFS, was proposed, inspired by octopus tentacles, with PVP as the backbone. FTIR, 1H NMR and Rg radius of gyration were used to characterize the functional groups and conformation of PVPAM-PPFS in aqueous environments. The composite coagulant exhibits facile dispersion in water. Upon hydrolysis of PVPAM-PPFS, numerous molecular chains resembling octopus tentacles are formed and confirmed through Atomic Force Microscopy (AFM). When applied to oily sewage in oilfields, PVPAM-PPFS demonstrates enhanced interaction with emulsified oil layers, capturing colloidal particles in water and thereby facilitating efficient separation of oil, water, and flocs. Lastly, the mechanism of PVPAM-PPFS was analyzed through a combination of coagulation experiments and detection of floc morphology. PVPAM-PPFS will better interact with colloidal particles in water through increased charge neutralization, bridging adsorption, and sweeping capabilities. Significantly, an enhanced crude oil recovery rate is observed from the recovered oil droplets following the disruption of the emulsion layer. [ABSTRACT FROM AUTHOR]

High operation and maintenance costs, and 'last-mile' issues for populations not connected to municipal water infrastructure, have limited the utility of centralized reverse osmosis (RO) systems to alleviate water availability issues for rural communities. To address these challenges, a decentralized RO module which employs tubular RO membranes was designed and investigated. The system represents an appropriate technology because it requires minimal pretreatment and it fits in self-contained, low-profile suitcase. This compact desgin also incorporated innovative 3D printed static mixers to minimize salt concentration polarization and to improve performance. Since grid electricity may also be discontinuous in the target use cases, the system was tested with two direct current (DC) power solutions: a photovoltaics-battery configuration and an alternator-battery. The final prototype weighs less than 15 kg and was found to have a production capacity of ∼8 L/h, consuming ∼100 W of pumping power. Experiments of the prototype module revealed a 96% rejection rate of salt from a 1000–2000 ppm synthetic groundwater solution and a >99% rejection coefficient for bovine serum albumin protein and humic acid. From these performance metrics, it was estimated that 36 sets of this decentralized system (with a total CapEx of US$23,400) could provide drinking water for ∼600 rural households at a unit cost of water of 1 LKR/L (0.005 USD/L) in Sri Lanka. Overall, this study demonstrates how computational modeling and 3D printing can be leveraged to develop a compact and cost-effective decentralized RO package that could be rapidly deployed to water-stressed rural areas and in disaster relief applications. [Display omitted] • A plug-and-play, compact DC driven mobile RO desalination system was developed. • Both alternator-battery and solar PV- battery power solutions were designed and tested. • The system is less than 15 kg and can produce 8 L/h of water with 100 W of power. • Rejection of 96% for salt and >99% for both protein and humic acid was observed. • The levelized cost of water of water was found to be < 0.005 USD/L. [ABSTRACT FROM AUTHOR]

The paper assesses the behavior of cohesive Geldart C-type particles, when fluidized by air with the aid of vibration. Together with their poor flowability and irregular hopper discharge, bubbling fluidization is very difficult to achieve due to the possible particle agglomeration and gas channeling. When trying to fluidize cohesive particles, the gas drag force cannot break the inter-particle bonds. Despite all these handling and operation problems, ultrafine particles of micron- or nanosize are increasingly applied in industrial processes. To disrupt the stable gas channels and cracks, a mechanical vibration is one of the easier and preferred methods to improve the fluidity of the cohesive particles. In the present study, several 2 to 40 μm particles were used. A comparison with Geldart A-type particles was also made. Experimental results were used to validate a more fundamental approach based upon the balance of forces acting on the particles. This resulted in a new delineation of the Geldart C/A boundary where the critical transition particle size for particles of given absolute density, ρ p , Hamaker constant, H , and inter-particle distance, z 0 , decreases with an increasing vibration intensity, I , according to d crit 2 ρ p = 8.03 H z 0 2 1 + I g. Mechanical vibration is a non-intrusive method to improve the fluidity of the cohesive particles and a new Geldart C/A boundary was modified for an increasing vibration intensity. [Display omitted] • Assesses the behavior of cohesive Geldart C-type particles, when fluidized by air with the aid of vibration. • Despite handling and operation problems, ultrafine particles are increasingly applied in industrial processes. • Mechanical vibration is a non-intrusive method to improve the fluidity of the cohesive particles. • Several 2 to 40 μm particles were examined and compared with Geldart A-type particles. • Experimental results and a balance of forces provided a new Geldart C/A boundary for an increasing vibration intensity [ABSTRACT FROM AUTHOR]

• A new method of chemical modification of bamboo was studied. • The green modification of perilladehyde improves the anti-fungal performance and dimensional stability of bamboo. • Chemical components of bamboo such as lignin and hemicellulose can serve as binding sites for perilladehyde. • Revealed the connection between the modification mechanism of perillaldehyde and bamboo properties. Bamboo exhibits potential as a viable substitute for wood; nevertheless, its vulnerability to mold poses a significant obstacle to its practical implementation. To address this issue, prevalent techniques, including heat treatment, chemical modification, and compression treatment, alter the characteristics of bamboo and safeguard it against mold. However, these modifications are limited by substantial energy consumption, elevated expenses, and low sustainability. In light of these challenges, perillaldehyde (PAE) emerges as a natural antimicrobial agent capable of impeding the proliferation of diverse mold strains. In this study, the immobilization of PAE in bamboo was achieved for the first time using diethylenetriamine, forming a Schiff base structure with bamboo components. The modified bamboo exhibited three-fold enhanced surface hydrophobicity, which effectively prevented mold infections. Additionally, the modification process improved the dimensional stability of bamboo, albeit at the expense of a slight reduction in elasticity and hardness. The structural analysis of bamboo by FTIR, XPS, and XRD techniques revealed that lignin and hemicellulose served as potential reactive components of PAE. This study presents a novel approach to bamboo preservation utilizing natural components, thereby enhancing the resistance against mold and improving the physical characteristics of bamboo. [ABSTRACT FROM AUTHOR]

In this paper, we study the immersed finite element (IFE) method for the multi-layer porous wall model for the drug-eluting stents. Firstly, under some realistic assumptions on the initial data and the body force, we deduce the long time p r i o r i stability for the variational problem for all t ∈ R +. Then, based on these results, the uniform optimal error estimates for both the semi-discrete IFE method and the fully discrete Euler IFE method are proved. Finally, some numerical experiments are performed to verify the theoretical predictions. [ABSTRACT FROM AUTHOR]

• Salicylic acid (SA) treatment suppressed the pericarp browning of harvested longans. • SA treatment retained higher levels of pericarp pigments in harvested longans. • SA treatment lowered cell membrane permeability in the pericarp of harvested longans. • SA treatment increased ROS scavenging capacity in the pericarp of harvested longans. • SA treatment reduced membrane lipid peroxidation in the pericarp of harvested longans. Longans is popular among consumers because of its rich nutritional value, but it is prone to pericarp browning as it is harvested in the high-temperature season. This work was to investigate the effects of salicylic acid (SA) on the metabolisms of reactive oxygen species (ROS) and membrane lipid and their relationship with pericarp browning of postharvest longans. 'Fuyan' longans were soaked in the solution of 0.3 g L-1 SA for 5 min, then stockpiled at 28 °C. The results showed that, the pericarp browning index in SA-treated fruit was 42% lower than that in the control fruit at day 5 of storage. Meanwhile, SA treatment reduced the damage severity of cell membrane structure, and maintained a low level of cell membrane permeability, which was 25% lower than that in the control fruit at day 5 of storage. Additionally, compared to the control fruit, SA-treated longans displayed higher levels of pericarp L* , flavonoid, chlorophyll, carotenoid, total phenolics, and anthocyanin, higher activities of pericarp superoxide dismutase, catalase, and ascorbate peroxidase, higher values of pericarp reducing power and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability, and higher amounts of pericarp ascorbic acid and glutathione, but lower levels of pericarp ROS and malondialdehyde. Moreover, SA-treated samples exhibited lower activities of pericarp phospholipase, lipase, and lipoxygenase, lower levels of pericarp phosphatidic acid and saturated fatty acids (SFA), but higher values of pericarp phosphatidylcholine, phosphatidylinositol, and unsaturated fatty acids (USFA), higher index of USFA, and higher ratio of USFA to SFA. These findings corroborated that SA delayed-browning occurrence in the pericarp of fresh longans was because SA enhanced the capacity to remove ROS, and reduced ROS accumulation and the membrane lipid degradation, thus maintaining the cellular membrane structure, reducing the degradation of pigments, and allowing the fresh longans to maintain a better appearance. Consequently, SA could be an effective means for suppressing pericarp browning and improving the commercial value of fresh longans. [ABSTRACT FROM AUTHOR]

Highlights • High quality Cr,Er:YAG crystal was grown successfully by the Czochralski method. • Maximum single-pulse energies of 0.99 and 1.52 J are obtained on Er:YAG and Cr,Er:YAG. • Slope efficiencies are 1.31% and 1.80% for Er:YAG and Cr,Er:YAG, respectively. • Cr3+ can improve laser efficiency of Cr,Er:YAG without affecting beam quality. • Cr,Er:YAG may be a potentially mid-infrared radiation-resistant laser material. Abstract We demonstrated an improvement of laser performance by co-doping Cr3+ into Er:YAG crystal grown by the Czochralski method. The result of X-ray rocking curve suggested that the crystal had high crystalline quality. Two strong absorption bands centered at 450 and 596 nm indicated the Cr,Er:YAG crystal was more suitable for xenon lamp pumping. A maximum single pulse energy of 1.52 J was obtained on the Cr,Er:YAG crystal operated at 5 Hz and 2.94 μm, corresponding to the slope efficiency and electrical-to-optical efficiency of 1.80% and 1.28%, but those of the Er:YAG crystal were only 0.99 J, 1.31% and 0.83%, respectively. Therefore, the Cr,Er:YAG crystal may be a potentially mid-infrared radiation-resistant laser material with higher single pulse energy and efficiency. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • 5-HMF can be converted to DFF by a green photocatalytic selective oxidation process. • 10.5% WO 3 /g-C 3 N 4 composite catalyst exhibits good performance under visible light. • A high DFF selectivity of 87.2% can be achieved under visible light. • The catalytic process follows a Z-scheme mechanism. Abstract WO 3 /g-C 3 N 4 (graphitic carbon nitride) composite was prepared via a directly calcination method with ammonium tungstate hydrate and melamine as raw materials, and applied in the photocatalytic oxidation of 5-hydroxymethylfurfural (5-HMF) to 2,5-diformylfuran (DFF) for the first time. Its physicochemical properties were characterized by HR(TEM), XRD, FT-IR, XP, UV-vis, PL, PC and EIS methods. The results revealed that the doping of WO 3 into g-C 3 N 4 can reduce the possibility of charge recombination and thus enhancing the photocatalytic activity. The impact factor, such as incident wavelength, reaction time, and solvent were also studied on the photocatalytic behavior. 4.7%WO 3 /g-C 3 N 4 composite catalyst exhibits the highest 5-HMF conversion of 27.4% with DFF selectivity of 87.2% under the irradiation of visible-light (>400 nm). As the active species, O 2 − and h+ plays an important role to convert 5-HMF to DFF. Finally, the Z-scheme mechanism and reaction route were proposed by combining the photocatalytic performance with the active oxygen species research of the WO 3 /g-C 3 N 4 catalyst. [ABSTRACT FROM AUTHOR]

A new Cr 3+ , Yb 3+ , Ho 3+ , and Pr 3+ co-doped GYSGG (Gd 2 YSc 2 Ga 3 O 12 ) single crystal with a size of Φ 26 mm × 80 mm was grown successfully using the Czochralski method for the first time. Absorption spectrum is studied, and main absorption bands are centered at 449, 638, and 934 nm. The fluorescence spectrum shows a broad emission band around 2.8 µm, indicating the Cr 3+ and Yb 3+ ions can act as the sensitizer for the Ho 3+ ions. The fluorescence lifetimes of the 5 I 6 and 5 I 7 levels of the Ho 3+ ions are fitted to be 0.39 and 5.31 ms, respectively. By comparison with those of the Cr,Yb,Ho:GYSGG crystal, the Pr 3+ ions acting as the deactivator can decrease efficiently the lifetime of the lower laser level 5 I 7 of the Ho 3+ ions. Additionally, a flash lamp pumping 2.84 µm laser with maximum average power of 257 mW is achieved. These results indicate the Cr,Yb,Ho,Pr:GYSGG crystal is a new promising radiation-resistant laser gain medium applied in radiant environment. [ABSTRACT FROM AUTHOR]

Particle suspensions can be used in Solar Power Towers to capture the solar heat at a high temperature, and convey it to the storage and the subsequent use in the power block. Thermal Energy Storage (TES) needs to be integrated. Temperatures of 600–900 °C foster the use of high-efficiency power generation cycles. Appropriate Phase Change Materials (PCMs) in that temperature range were examined, i.e. Sb 2 O 3 for the lower melting point range, and BaCO 3 and its Na 2 CO 3 compounds as high melting PCMs. Cooling rates of the melt and solid phases follow a linear-time relationship. The time for solidification of the melt is also measured. Rates and times are compared with the theoretical approaches of unsteady state conduction and phase transition. The cooling rate of the melt is significantly higher than the cooling rate of the solid phase. The time of phase transition is a function of the latent heat. Natural convection within the melt enhances the heat transfer, and is predicted by assigning an effective thermal conductivity to the melt. The thermal cycling of the encapsulated PCMs demonstrates that the selected encapsulation material retains its mechanical properties for 1250 charge/discharge cycles. Practical considerations on TES design conclude the research. [ABSTRACT FROM AUTHOR]

Solar thermal electricity generated by concentrated solar power (CSP) plants is increasingly implemented. CSP plants can supply electricity on a fully matched supply-demand basis if equipped with a thermal energy storage. To increase the efficiency and reduce both capital and operating costs, a next generation of CSP concepts is required. Particle suspensions can be applied to meet these targets and can be used throughout the CSP conversion process, as high temperature heat transfer medium in the receiver, for heat storage, and in the power block of the plant. This work presents the novel concept of using particle suspensions as heat carriers, mostly further to initial testing at the CNRS 1 MW solar furnace of Odeillo Font-Romeu (F). Values of the heat transfer coefficient up to 1100 W/m 2 K (bare tubes) and 2200 W/m 2 K (finned tubes) were obtained for operation at low superficial gas velocities of 0.04–0.19 m/s, thus limiting heat losses by the exhaust air. Despite additional costs for particle handling and for an appropriate boiler, the required overall investment and operating costs are expected to be significantly lower than for common equivalent molten salt CSPs, leading to a reduction in Levelized Cost of Electricity (LCOE) from approximately 125 €/MWh to below 100 €/MWh. [ABSTRACT FROM AUTHOR]

• Laser performance of LD side-pumped Er:LuYSGG bonding crystal was demonstrated. • Maximum output power of 20.76 W is achieved and improved effectively by bonding. • M 2 factors of 6.80/6.74 of the bonding crystal are better than that of un-bonding one. • Er:LuYSGG bonding crystal is a promising 2.8 μm gain element operated at high power. We demonstrate the laser performance of 970 nm LD side-pumped LuYSGG/Er:LuYSGG/LuYSGG bonding crystal in a frequency range of 50–800 Hz. The thermal distribution simulation implies that the bonded Er:LuYSGG crystal possesses a higher cooling efficiency compared with the un-bonded one. The maximum average power of 20.76 W is realized at a frequency of 150 Hz and a pulse width of 200 μs, corresponding to a slope efficiency of 23.94 % and optical-to-optical conversion efficiency of 19.22 %. A single laser wavelength of 2797.5 nm is observed. The M 2 factors of the bonding rod are 6.80/6.74, indicating a relatively high beam quality. Therefore, the LuYSGG/Er:LuYSGG/LuYSGG bonding crystal exhibits an improvement of laser performance operated at 2.8 μm due to excellent heat dissipation ability, which is a promising gain element and can be applied to the harsh radiation environment. [ABSTRACT FROM AUTHOR]

Bamboo's long-acting mold resistance is essential to its durability and applications. Cinnamaldehyde can be used to protect bamboo against microorganisms, but bonding linkages are easily broken, resulting in poor anti-mold performance. In this study, for the first time, cinnamaldehyde was successfully introduced into bamboo constituents via an in-situ Mannich reaction. As a result of the modification, stronger anti-mold resistance was observed for bamboo with a cinnamaldehyde Schiff base structure. The increased surface hydrophobicity of modified bamboo caused by various levels of cinnamaldehyde fixation effectively negated mold affection. Multiple approaches were used to identify bamboo lignin and xylan as cinnamaldehyde binding sites, revealing the underlying mechanisms of reaction. This study provides new insight into green chemistry-based strategies for bamboo preservation under Mannich reactions, in addition to demonstrating a reliable pathway to improve the mold resistance of bamboo. [Display omitted] • A novel approach to improving bamboo's mold resistance was developed. • Lignin and hemicellulose were identified as the targeted biopolymers. • The mechanisms behind bamboo's linkages and changes in morphology were shown. [ABSTRACT FROM AUTHOR]

In this work, different synthetic methods of polymeric aluminum silicate sulfate (PASS) and their coagulability to oily sewage were comparatively studied. PASS was synthesized by two methods: gravity supercritical method and basic titration method, denoted as PASS-B and PASS-S, respectively. The results show that the PASS prepared by gravity supercritical method has better Alb and stability. By applying two coagulants to oily sewage, it was found that PASS-B exhibited better turbidity and oil removal. It was found that PASS-B still has good coagulation by testing its coagulation after placing the coagulant for 2 months. In acidic test water, PASS-B exhibited stronger deprotonation ability. Finally, the polymerization mechanism and coagulation mechanism of PASS-B were analyzed in combination with Al morphology distribution and coagulation experiments. Gravity supercritical method as a new polymerization method may replace the traditional preparation method of inorganic polymer coagulants in the future, especially in large-scale applications. [Display omitted] • Gravity supercritical method can reduce PASS preparation time. • Gravity supercritical method can improve the stability and the Alb of the PASS. • This method may replace traditional polyaluminum preparation process in the future. [ABSTRACT FROM AUTHOR]

• Hydrophobically associated PASSi-C16 was successfully prepared. • PASSi-C16 has a similar structure to the emulsion layer. • PASSi-C16 can better interact with the emulsion layer. • PASSi-C16 composite needs for large-scale applications. When the amount of anionic polyacrylamide (APAM) and petroleum sulphonate in polymer-flooding oily sewage increases, a stable emulsification system forms. This makes the treatment of oily sewage increasingly difficult. To better develop high-efficiency coagulants from scratch, this study first determined the structure and carbon number of petroleum sulphonate using 1H NMR and 13C NMR spectroscopy. Then, hydrophobic monomers with different chain lengths were copolymerised with aluminium salts to prepare inorganic polymer coagulants with different hydrophobic association abilities. Three novel coagulants were successfully prepared, as verified by FTIR and hydrodynamic radius detection, and their coagulation mechanism and performance in oily sewage were investigated and compared with (polyaluminium silicate sulphate) PASSi. The particle size and morphology of flocs after the addition of coagulant were detected by laser particle size analysis and scanning electron microscopy. The structure-activity relationship between emulsifiers and coagulants with different chain lengths was studied via the second virial coefficient A 2. Polyaluminium silicate sulphate-hexadecyltrimethoxy (PASSi-C16) was determined to have the best coagulation effect by turbidity, oil removal rate and Zeta potential detection. This may have been due to PASSi-C16 containing a similar lipophilic group to the carbon chain structure of petroleum sulphonate, which could easily destroy the emulsion layer. These results provide insights into methods to improve the hydrophobic association capacity and for the targeted use of associative coagulants in large-scale applications. [ABSTRACT FROM AUTHOR]

• Influence of 60Co gamma-ray irradiation on the Er:LuYSGG crystal was demonstrated. • Maximum average output power of 886 mW is achieved after irradiation. • Maximum output power and slope efficiency are reduced by only 2.5% and 3.7%. • Lifetime ratio between lower and upper laser levels is reduced after irradiation. • Er:LuYSGG crystal is a potential 2.79 μm radiation-resistant laser material. We demonstrate the influence of gamma-ray irradiation on the structure, spectroscopies, and laser performance of Er:LuYSGG crystal. After 100 Mrad 60Co gamma-ray irradiation, the crystal structure remains unchanged, the absorption near 968 nm and emission within 2.7 ∼ 3 μm are almost unaffected, the level lifetimes are reduced, and the maximum output power of 886 mW is achieved with a maximum slope efficiency of 20.8%. The maximum output power and slope efficiency decrease by only 2.5% and 3.7% after irradiation, respectively, and the M 2 factor is little affected by irradiation. The results indicate that the Er:LuYSGG crystal is a potential mid-infrared radiation-resistant laser material applied in radiation environments. [ABSTRACT FROM AUTHOR]

Structure, defects, and spectroscopic properties of a Yb,Ho,Pr:YAlO 3 (Yb,Ho,Pr:YAP) single crystal grown by the Czochralski method were investigated. The effective segregation coefficients of the Yb 3+ , Ho 3+ , and Pr 3+ ions are 1.06, 1.32, and 0.90 in YAP host, respectively. The structural parameters are obtained by the X-ray Rietveld refinement method. A high crystalline quality of the Yb,Ho,Pr:YAP is determined by the X-ray rocking curve. The dislocations of (100), (010), and (001) faces are studied using the chemical etching with the phosphoric acid etchant. The absorption spectra show that there exists strong absorption in the wavelength range of 900–1000 nm, and the fluorescence spectrum excited by 970 nm LD presents that the strongest emission is located at 2853 nm, indicating the Yb 3+ ions can be acted as the sensitizer for the Ho 3+ ions. The level lifetimes indicate that the Pr 3+ ions can play a deactivator role for the Ho 3+ ions. All these results imply that the Yb,Ho,Pr:YAP crystal can be regarded as a promising candidate for realizing 2.8–3.1 μm laser output. [ABSTRACT FROM AUTHOR]

Thermal energy storage (TES) transfers heat to storage media during the charging period, and releases it at a later stage during the discharging step. It can be usefully applied in solar plants, or in industrial processes, such as metallurgical transformations. Sensible, latent and thermo-chemical media store heat in materials which change temperature, phase or chemical composition, respectively. Sensible heat storage is well-documented. Latent heat storage, using phase change materials (PCMs), mainly using liquid–solid transition to store latent heat, allows a more compact, efficient and therefore economical system to operate. Thermo-chemical heat storage (TCS) is still at an early stage of laboratory and pilot research despite its attractive application for long term energy storage. The present review will assess previous research, while also adding novel treatments of the subject. TES systems are of growing importance within the energy awareness: TES can reduce the LCOE (levelized cost of electricity) of renewable energy processes, with the temperature of the storage medium being the most important parameter. Sensible heat storage is well-documented in literature and applied at large scale, hence limited in the content of the present review paper. Latent heat storage using PCMs is dealt with, specifically towards high temperature applications, where inorganic substances offer a high potential. Finally, the use of energy storage through reversible chemical reactions (thermo-chemical storage, TCS) is assessed. Since PCM and TCS storage media need to be contained in a capsule (sphere, tube, sandwich plates) of appropriate materials, potential containment materials are examined. A heat transfer fluid (HTF) is required to convey the heat from capture, to storage and ultimate re-use. Particle suspensions offer a valid alternative to common HTF, and a preliminary assessment confirms the advantages of the upflow bubbling fluidized bed and demonstrates that particulate suspensions enable major savings in investment and operating costs. Novel treatments of the TES subject in the review involve the required encapsulation of the latent and chemical storage media, the novel development of powder circulation loops as heat transfer media, the conductivity enhancement of PCMs, the use of lithium salts, among others. [ABSTRACT FROM AUTHOR]

A novel application of powders relies on their use as heat transfer medium for heat capture, conveying and storage. The use of powders as heat transfer fluid in concentrated solar systems is discussed with respect to current technologies. The specific application reported upon is the use of powder loops in Solar Power Tower plants. In the proposed receiver technology, SiC powder is conveyed as a dense particle suspension through a multi-tube solar receiver in a bubbling fluidization mode, the upwards flow being established by pressurizing the powder feed. Tests were conducted with a single-tube receiver unit at the 1 MW solar furnace of CNRS (Odeillo Font-Romeu, F). The measured wall-to-suspension heat transfer coefficient is a function of operating temperature, applied air velocity and imposed solid circulation flux: values increased with increasing solids flux from ∼430 to 1120 W/m 2 K. Empirical approaches and a heat transfer model were applied to compare experimental and predicted values of the heat transfer coefficient, with a fair agreement obtained. The research moreover provides initial data concerning the overall economy of the system. The high temperature of the circulating powder leads to an increased power cycle efficiency, an increased storage density, reduced thermal power requirements, reduced heliostat field size, reduced parasitic power consumption and increased plant capacity factor. [ABSTRACT FROM AUTHOR]

New developments of fluidized beds are focusing on their use in powder circulation systems for thermal energy capture, storage and re-use. Although fast particle motion and associated high degree of mixing favor the high rate of heat transfer in fluidized beds, they however cause inter-particle collision and bed-to-wall impacts, both leading to particle attrition. Experimental work on attrition was carried out in batch gas fluidized beds of 6.62 cm and 10 cm I.D. The rate of attrition was determined both for bubbling fluidized bed conditions, and when adding jet-orifices above the distributor. The attrition was determined from the variation in composition of bed material and collected carryover. A literature survey determined the dominant fluidization parameters, including operating superficial gas velocity, orifice velocity and size, bed weight and diameter, and particle characteristics. Analysis of the experimental findings resulted in a correlation that encompasses all relevant operating characteristics. As a result, the attrition rate can be correlated as the sum of the bubble-induced and jet-induced contribution: R t = K 1 γ U − U m f ⋅ W D + K 2 n or ⋅ d or 2 ⋅ U or 2 with K 1 and K 2 , the intrinsic attrition rate constants, being mainly a function of particle characteristics. K 1 is ~ 10 − 5 for soft, ~ 10 − 6 for hard and ~ 10 − 7 for very hard particles, respectively. K 2 is ~ 10 − 5 for silica sand. In general, attrition is negligible at low superficial gas velocities, but significantly increases through the jet-induced contribution if the orifice velocity exceeds ~ 30 m/s. [ABSTRACT FROM AUTHOR]

Lu 2.4 Y 0.6 Al 5 O 12 (LuYAG) crystals with three different doping concentrations of Tm 3+ and Ho 3+ were grown successfully by the Czochralski method. The crystals exhibit broad absorption band at 783 nm and the full width at half maximum (FWHM) are about 11 nm. Excited by 783 nm laser diode (LD), strong fluorescence peaks are observed near 2.9 μm, suggesting that the Tm 3+ ions can act as the sensitizer for Ho 3+ ions. The stimulated emission cross-sections at 2.911 μm are calculated to be 5.49 × 10 −18 cm 2 , 3.11 × 10 −18 cm 2 , and 4.04 × 10 −18 cm 2 , respectively. Compared with the Tm,Ho:LuAG, and Tm,Ho:YAG crystals, the Tm,Ho:LuYAG crystal with 3 at.% Tm 3+ and 1 at.% Ho 3+ has a relatively longer lifetime 0.138 ms for the upper level 5 I 6 and a shorter lifetime 7.25 ms for the lower level 5 I 7 , which is advantageous to the population inversion. These results indicate that the Tm,Ho:LuYAG crystal with 3 at.% Tm 3+ and 1 at.% Ho 3+ is a new potential candidate for realizing the 2.911 μm laser output. [ABSTRACT FROM AUTHOR]

A novel Yb,Ho,Pr:LuYAG laser crystal was successfully grown and investigated in detail, which belongs to the cubic system with a space group of I a-3d. The X-ray rocking curve of the as-grown crystal implied high crystalline quality. The dislocation defects were revealed by the chemical method. Moreover, the density, thermal expansion coefficient and thermal conductivity were determined. The absorption coefficient at 935 nm and the emission cross-section at 2.911 μm were obtained to be about 15.18 cm−1 and 2.23 × 10−21 cm2, respectively. The lifetime of the lower laser level 5I 7 was shown to decrease from 7.58 to 5.88 ms, while that of the upper laser level 5I 6 basically remained unchanged, suggesting that the co-doped Pr3+ possessed an efficient deactivation effect and was beneficial in attaining population inversions of Ho3+. The corresponding findings illustrate that the Yb,Ho,Pr:LuYAG crystal can serve as a novel promising gain medium for realizing the 2.911 μm laser pumped by ~ 940 nm high-power InGaAs laser diode. • A novel Yb,Ho,Pr:LuYAG laser crystal was successfully grown by Czochralski method. • The crystal possesses a high thermal conductivity, which is helpful in dissipating heat during laser action. • Yb3+ makes the crystal suitable for 935 nm LD pumping and Pr3+ can inhibit self-termination phenomenon. • High absorption coefficient at 935 nm and large emission cross-section at 2911 nm are beneficial in realizing ∼2.9 μm laser. • The Yb,Ho,Pr:LuYAG crystal is a new promising gain medium for realizing 2.911 μm laser. [ABSTRACT FROM AUTHOR]

Cocrystallization can improve physical and chemical properties of active pharmaceutical ingredient, and this feature has great potential in pharmaceutical development. In this study, the cocrystal of piracetam and 3-hydroxybenzoic acid under grinding condition has been characterized by Raman and terahertz spectroscopical techniques. The major vibrational modes of individual starting components and cocrystal are obtained and assigned. Spectral results show that the vibrational modes of the cocrystal are different from those of the corresponding parent materials. The dynamic process of such pharmaceutical cocrystal formation has also been monitored directly with Raman and THz spectra. The formation rate is pretty fast in first several 20 min grinding time, and then it becomes slow. After ∼35 min, such process has been almost completed. These results offer us the unique means and benchmark for characterizing the cocrystal conformation from molecule-level and also provide us rich information about the reaction dynamic during cocrystal formation process in pharmaceutical fields. [ABSTRACT FROM AUTHOR]

Vibrational spectra of hydrated and anhydrous lamivudines, and also the dynamic process of polymorphic transformation have been characterized by Fourier transform infrared (FT-IR) and Raman spectroscopic techniques. The vibrational modes of both polymorphic lamivudines are assigned. FT-IR and Raman spectral results show that the interaction between crystalline water and lamivudine molecular has an important effect on the molecular vibration motions of polymorphic lamivudines. The two characteristic Raman peaks at 783 and 798 cm −1 represent hydrated and anhydrous lamivudine respectively. The relationship between changes of two characteristic peak normalized areas and heating time could be fitted with single exponential functions, and the dynamic information of polymorphic transformation of lamivudine drug is obtained. The decay rate of characteristic peak for hydrated lamivudine and the growth rate of that for anhydrous lamivudine are consistent during dehydration transformation process. The reported results provide us important benchmark for qualitatively monitoring different polymorphic drugs and also establishing the corresponding model for the polymorphic transformation of drugs in related pharmaceutical research fields. [ABSTRACT FROM AUTHOR]

Yb,Ho:YAP and Yb,Ho,Pr:YAP laser crystals with high optical quality are successfully grown using the Czochralski method. The absorption coefficient and band width of the two crystals at 970 nm are increased because of the doping of Yb 3+ sensitizer. The three strongest fluorescence peaks of the two crystals are located at approximately 2844, 2853, and 2912 nm, which correspond to the 5 I 6 → 5 I 7 level transitions of Ho 3+ ions. Lifetime measurements indicate that the deactivator Pr 3+ ions can efficiently decrease the lifetime of the lower level 5 I 7 from 8.848 ms to 1.258 ms. Energy-transfer mechanisms are also studied and analyzed, and up-conversion luminescence spectra provide the further evidence that Pr 3+ ions can efficiently depopulate Ho 3+ ions at the 5 I 7 level. All these results show that Yb,Ho,Pr:YAP crystal may be a promising laser medium for realizing 2.8–3.1 μm lasers pumped using a 970 nm laser diode. [ABSTRACT FROM AUTHOR]

Highlights: [•] Photocatalytic activity of the WO3 nanoplates is much higher than commercial WO3. [•] OH is proved the active species responsible for photocatalytic reactions over WO3. [•] The photocatalytic reaction mechanism of the WO3 nanoplates is confirmed. [•] The template-free hydrothermal route is facile, cost effective and can be scaled up. [Copyright &y& Elsevier]

Highlights: [•] A new Cr,Yb,Ho,Eu:YAP laser crystal was grown by the CZ method for the first time. [•] Thermal properties indicate the suitable crystal growth direction is the b axis. [•] Spectroscopic measurements show Cr3+ and Yb3+ can act as sensitizers of Ho3+ ions. [•] Eu3+ ions can act as deactivator in decreasing threshold and increasing efficiency. [ABSTRACT FROM AUTHOR]

• The hydrophobic association PASS was prepared by a base titration method. • PASS with a small amount of lipophilic group could be improving charge neutralization ability. • The crude water containing polymer was effectively treated. • Floc properties were comparatively investigated. The use of oil recovery technologies has resulted in the weakening of interfacial tension between oil and water in oilfield wastewater due to a large amount of polymer present. This leads to the formation of stable emulsified colloidal systems and increases the difficulty of oilfield wastewater treatment. This study investigated hydrophobically-modified polyaluminium silicate sulphate (PASS-C) as a coagulant for oilfield wastewater treatment. PASS-C was prepared by the condensation polymerisation of Al 2 (SO 4) 3 ·18H 2 O with dialysed and hydrolysed KH570 [3-(trimethoxysilyl)propyl methacrylate] under titration with NaAlO 2 and water glass at low temperature. The zeta potential of PASS-C showed that the introduction of hydrophobic groups increased its charge neutralisation ability. Additionally, compared with conventional PASS, PASS-C showed a satisfactory oil removal rate from simulated polymer flooding oily wastewater. When the hydrophobic group content was 1% and the dosage of PASS-C was 140 mg·L–1, the optimal oil removal rate and turbidity removal rate was 95% and 98%, respectively. The particle size and morphology of the coagulated flocs were characterised by laser particle size analysis and SEM. Compared with PASS, PASS-C formed a larger and more compact floc. These findings indicated that the good flocculability of PASS-C for crude oil wastewater was attributable to the synergistic effects of charge neutralisation, hydrophobic associations and adsorption bridging. [ABSTRACT FROM AUTHOR]

Two-dimensional layered semiconductor photocatalysts have attracted much attention due to their excellent performance. Layered photocatalyst, however, generally has low visible-light utilization and is easy to self-polymerize. In this study, layered photocatalyst Ni x Sr 1-x TiO 3 was prepared by doping Nickelin perovskite, and then loaded on RGO with a larger specific surface area. Heterojunction photocatalyst with high performance was successfully prepared. The results show that doping Ni will introduce an occupied energy level between the band gaps, effectively reducing the forbidden bandwidth, and the wavelength of 600 nm still has a high optical response. Much elevated photocatalytic degradation was investigated after further loading Ni x Sr 1-x TiO 3 onto RGO. As a carrier, RGO can improve the self-polymerization of the catalyst and form heterojunction with NixSr1-xTiO 3. The transfer of photogenerated carriers is promoted relying on the potential difference between the two sides of the heterojunction interface and the electron transport channel of RGO. We also noticed that the unique amphoteric molecular properties of RGO can improve the dispersion of Ni x Sr 1-x TiO 3 -RGO in dye wastewater. To sum up, the synergistic effect of reducing band gaps, inhibiting heterojunction structure and improving dispersion are the reasons for more efficient activity. [Display omitted] • 2D lamellar perovskite improves the separation of electron-hole pairs. • The doping of Ni particles broadens the light response range. • NixSr 1-x TiO 3 was successfully loaded on RGO with a larger specific surface area to improve its dispersion. • Heterojunction layered catalysts show better performance. [ABSTRACT FROM AUTHOR]

Abstract: Hydrogen sulfide (H2S) is a novel gaseous mediator that plays important roles in atherosclerosis. The present study investigated the effect of a novel H2S-releasing aspirin, ACS14 (2-acetyloxybenzoic acid 4-(3-thioxo-3H-1,2-dithiol-5-yl)phenyl ester), on atherosclerotic plaques in fat-fed apoE–/– mice and the underlying mechanism with respect to CX3C chemokine receptor 1 (CX3CR1) in macrophages. Mouse macrophage cell line RAW264.7 or mouse peritoneal macrophages were preincubated with aspirin (50, 100 or 200μM), ACS14 (50, 100 or 200μM) or vehicle for 6h, and then stimulated with interferon (IFN)-γ (500U/ml) or lipopolysaccharide (LPS; 10μg/ml) for 12h. ACS14, but not aspirin, dose-dependently inhibited IFN-γ or LPS-induced CX3CR1 expression and CX3CR1-mediated chemotaxis in macrophages. The inhibitory effect of ACS14 on CX3CR1 expression was abolished by pretreatment with GW9662, a selective peroxisome proliferator-activated receptor (PPAR)-γ antagonist, suggesting that suppression of macrophage CX3CR1 expression by ACS14 is PPAR-γ dependent. Eight-week-old male apoE–/– mice received intraperitoneal ACS14 (15 or 30μmol/kg/day) or aspirin (15 or 30μmol/kg/day) 4 weeks after fat feeding. Twelve weeks after ACS14 or aspirin treatment, mice were sacrificed to evaluate the extent of atherosclerosis and CX3CR1 expression in brachiocephalic artery (BCA). We found that ACS14, but not aspirin, significantly downregulated CX3CR1 expression in atherosclerotic plaques. ACS14 considerably impeded the formation and development of atherosclerosis as compared to a molar equivalent dose of aspirin. These data indicate that ACS14 may prevent the progression of atherosclerosis by downregulating macrophage CX3CR1 expression via a PPAR-γ-dependent mechanism. [Copyright &y& Elsevier]

Abstract: A new exogenous glutamic acid-independent γ-PGA producing strain was isolated and characterized as Bacillus subtilis C10. The factors influencing the endogenous glutamic acid supply and the biosynthesis of γ-PGA in this strain were investigated. The results indicated that citric acid and oxalic acid showed the significant capability to support the overproduction of γ-PGA. This stimulated increase of γ-PGA biosynthesis by citric acid or oxalic acid was further proved in the 10L fermentor. To understand the possible mechanism contributing to the improved γ-PGA production, the activities of four key intracellular enzymes were measured, and the possible carbon fluxes were proposed. The result indicated that the enhanced level of pyruvate dehydrogenase (PDH) activity caused by oxalic acid was important for glutamic acid synthesized de novo from glucose. Moreover, isocitrate dehydrogenase (ICDH) and glutamate dehydrogenase (GDH) were the positive regulators of glutamic acid biosynthesis, while 2-oxoglutarate dehydrogenase complex (ODHC) was the negative one. [Copyright &y& Elsevier]

Abstract: By using the first-principles calculations based on the density-functional theory (DFT), we study the stability and the nonlinear elasticity of two-dimensional (2D) hexagonal structures of Si and Ge. The reproduced structure optimization and phonon–dispersion curves demonstrate that Si and Ge can form stable 2D hexagonal lattices with low-buckled structures, and provide a good agreement with the previous DFT calculations. The second- and third-order elastic constants are calculated by using the method of homogeneous deformation. The present results of the linear elastic moduli agree well with the previous results. In comparison with the linear approach, the nonlinear effects really matter while strain is larger than approximately 3.5%. The force–displacement behaviors and the breaking strength of 2D hexagonal Si and Ge are discussed using the nonlinear stress–strain relationship. By using the available results of graphene, we reasonably demonstrate that the radius of the atom increases and breaking strength of this element decreases for 2D hexagonal structures of group IV-elements. [Copyright &y& Elsevier]

Abstract: This work proposed a gas sensor for the determination of tert-butyl mercaptan, one of the highly toxic volatile sulfur compounds, which was based on cataluminescence emission during its catalytic oxidation on the surface of nanosized V2O5. The cataluminescence characteristics and the optimum conditions, including the morphology of sensing material, the wavelength of cataluminescence emission, the oxygen flow rate and working temperature were investigated in detail. Under the optimized conditions, the calibration curve of the relative cataluminescence intensity versus the concentration of tert-butyl mercaptan vapor was made, with the linear range of 5.6–196μgmL−1 and the detection limit of 0.5μgmL−1 (S/N =3). The relative standard deviation (R.S.D.) (n =5) of relative cataluminescence intensity for 84μgmL−1 tert-butyl mercaptan was 3.6%. There is no or weak response to some common substances, such as formic acid, alcohol (methanol, ethanol, propanol, isopropanol, n-butanol, isoamyl alcohol), o-dichlorobenzene, acetonitrile, ethyl acetate, aldehyde (formaldehyde, acetaldehyde and propanal), 1,2-dichloroethane and ammonia. Furthermore, the proposed sensor was successfully used for determining tert-butyl mercaptan in four artificial samples, with a good recovery. The results demonstrated that the proposed gas sensor had a promising capability for the tert-butyl mercaptan in routine monitoring. [Copyright &y& Elsevier]

Abstract: The use of electrostatic collection was investigated in quantifying airborne environmental allergens and toxins. The experiments were conducted with two 96-well plates filled with water and placed into the electrostatic sampler designed in this study. The combinations of different electrostatic fields: 0.63, 1.25kV/cm, and different sampling flow rates: 5, 12.5L/min, were tested with the electrostatic sampler. As a reference, a BioSampler operating at 12.5L/min was simultaneously placed in the same environments. The sampling lasted for 40min both for electrostatic sampler and the BioSampler in each test. House dust allergens, endotoxin and (1,3)-β-d-glucans in the air samples collected were analyzed using enzyme-linked immunosorbent assay (ELISA) and Limulus amebocyte lysate (LAL) method, respectively. The entire experiments were conducted both in office environment and hotel rooms. The concentrations of airborne allergens (Der p 1 and Der f 1) and toxins (endotoxin and (1,3)-β-d-glucans) obtained by the electrostatic sampler were shown significantly higher than those by the BioSampler in most cases. Paired t-tests (n=9) indicated that the sampling difference was statistically significant (p-value <0.05). For allergens, the concentration ratio was up to 5.6, and for toxins the concentration ratio was up to 10.8 when the electrostatic sampler was operated at 1.25kV/cm and 5L/min. In general, the concentration ratio decreased for both allergens and toxins when the electrostatic field strength decreased or when the sampling flow rate increased for the electrostatic sampler. Paired t-tests (n=9) also indicated there were statistically significant effects of electrostatic field strength and the sampling flow rates on the performance of the electrostatic sampler when collecting the airborne allergens and toxins. This study presented an airborne environmental allergen and toxin monitoring technology, which holds broad promise for detecting and quantifying low level environmental allergen and toxins. [Copyright &y& Elsevier]

As a hybrid of the Parallel Two-stage Flowshop problem and the Multiple Knapsack problem, we investigate the scheduling of parallel two-stage flowshops under makespan constraint, which was motivated by applications in cloud computing and introduced by Chen et al. [3] recently. A set of two-stage jobs are selected and scheduled on parallel two-stage flowshops to achieve the maximum total profit while maintaining the given makespan constraint. We give a positive answer to an open question about its approximability proposed by Chen et al. [3]. More specifically, based on guessing strategies and rounding techniques for linear programs, we present a polynomial time approximation scheme (PTAS) for the case when the number of flowshops is a fixed constant. As the case with two flowshops is already strongly NP-hard, our PTAS achieves the best possible approximation ratio. [ABSTRACT FROM AUTHOR]

A Nd3+-doped Y 2.8 ScAl 4.2 O 12 (Nd:YSAG) single crystal was grown successfully via the Czochralski technology. The crystal structure and crystalline quality of the as-grown Nd:YSAG crystal were determined by the X-ray powder diffraction and X-ray rocking curve, respectively. By X-ray fluorescence analysis, the effective segregation coefficient of Nd3+ is calculated to be 0.33 in the YSAG crystal. Using the chemical etching method, the dislocation density on the (111)-crystalline face is obtained to be about 3.45 × 102 cm−2. The large absorption cross-section (2.95 × 10−20 cm2) and wide FWHM (9.8 nm) around 808.8 nm imply a high LD pumping efficiency. The high emission cross-section (3.53 × 10−20 cm2) at 1336.3 nm and long fluorescence lifetime of Nd3+ ions (286.20 μs) are beneficial to realize laser output. Thereby, all the results indicate that the Nd:YSAG crystal is a potentially new gain material pumped by a LD for near-infrared laser at 1336.3 nm. • A Nd3+:Y 2.8 ScAl 4.2 O 12 crystal was grown successfully by the Czochralski method. • Dislocation density on the (111)-crystalline face is obtained to be 3.45 × 102 cm−2. • A large absorption cross-section (2.95 × 10−20 cm2) implies high pumping efficiency. • High emission cross-section (3.53 × 10−20 cm2) is beneficial to realize 1336.3 nm laser. • All results indicate this crystal is a potential gain material for 1336.3 nm laser. [ABSTRACT FROM AUTHOR]

Hydrogen is a common reactant in the petro-chemical industry and moreover recognized as a potential fuel within the next 20 years. The production of hydrogen from biomass and carbohydrate feedstock, though undoubtedly desirable and favored, is still at the level of laboratory or pilot scale. The present work reviews the current researched pathways. Different types of carbohydrates, and waste biomass are identified as feedstock for the fermentative bio-hydrogen production. Although all techniques suffer from drawbacks of a low H 2 yield and the production of a liquid waste stream rich in VFAs that needs further treatment, the technical advances foster the commercial utilization. Bacterial strains capable of high hydrogen yield are assessed, together with advanced techniques of co-culture fermentation and metabolic engineering. Residual VFAs can be converted. The review provides an insight on how fermentation can be conducted for a wide spectrum of feedstock and how fermentation effluent can be valorized by integrating fermentation with other systems, leading to an improved industrial potential of the technique. To boost the fermentation potential, additional research should firstly target its demonstration on pilot or industrial scale to prove the process efficiency, production costs and method reliability. It should secondly focus on optimizing the micro-organism functionality, and should finally develop and demonstrate a viable valorization of the residual VFA-rich waste streams. • Hydrogen is a common reactant in the chemical industry and a potential fuel. • Review of the current researched fermentation bio-hydrogen pathways. • New developments (e.g. metabolic engineering, H 2 separation) are assessed. • Fermentation has low H 2 production yields. The fermentation effluent, rich in VFAs, needs further treatment. [ABSTRACT FROM AUTHOR]

The fabrication of poly(vinylidene fluoride) (PVDF) based foam with complicated three-dimensional (3D) geometry and excellent piezoelectric property remains great challenge worldwide. In this study, microcellular PVDF/multiwalled carbon nanotube (MWCNT) nanocomposite foaming part was fabricated by supercritical carbon dioxide (scCO 2) bead foaming technology. With the assistance of the ball milling, the good dispersion of MWCNT particles in PVDF matrix was achieved, which promoted the heterogeneous nucleation and enhancement effects of MWCNT on PVDF, resulting in the formation of more unique and denser cells, e.g. from 3.4 × 105 cells/cm3 of pure foam to 1.7 × 106 cells/cm3 of the composite foam when MWCNT content was 1.5%, and high compression strength, i.e. 3.1 MPa with 1.5% MWCNT at 10% compressive strain, about 1.1 MPa higher than that of pure foam. During the bead foaming process, the induced crystallization effect of MWCNT as well as the plasticizing and squeezing effect of scCO 2 on PVDF matrix contributed to the increase of the β-phase crystal in PVDF matrix, thus endowing the composite foaming part with good piezoelectric property, i.e. 6.5 V of output voltage under periodic compression, which lightened 4 LEDs and made the foaming part had wide potential application in smart electronic field. [ABSTRACT FROM AUTHOR]

The control of laccase-catalyzed efficiency often relies on the utilization of modifying enzyme molecules and shielding agents. However, their elevated costs or carcinogenicity led to the inability for large-scale application. To address this concern, we found that a low-cost protein from soybean meal can reduce lignin's ineffective adsorption onto enzymes for improving the efficiency of thymol grafting to lignosulfonate. The results demonstrated that by adding 0.5 mg/mL of additional soybean meal protein, the thymol reaction ratio of the modified lignosulfonate (L-0.5 S) significantly boosted from 18.1 % to 35.0 %, with the minimal inhibitory concentrations of the L-0.5 S against Aspergillus niger dramatically improved from 12.5 mg/mL to 3.1 mg/mL. Multiple characterization methods were employed to better understand the benefit of the modification under the addition of the soybean meal protein. The C O and R 1 -O group content increased from 20.5 % to 37.8 % and from 65.1 % to 75.5 %, respectively. The proposed potential reaction mechanism was further substantiated by the physicochemical properties. The incorporation of soybean meal effectively mitigated the non-specific adsorption of lignosulfonate, resulting in a reduction of the surface area of lignin from 235.0 to 139.2 m2/g. The utilization of soybean meal as a cost-effective and efficient shielding agent significantly enhanced the efficiency of subsequent enzyme catalysis. Consequently, the application of soybean meal in commercial enzyme catalysis holds considerable appeal and amplifies the relevance of this study in preservative industries. [ABSTRACT FROM AUTHOR]

• Er,Pr:YAP crystals with two different Pr3+ concentrations are grown by CZ method. • Influence of Pr3+ concentrations on the luminescence and laser properties are investigated contrastively. • Watt-level ∼2.7 μm laser is achieved on the Er,0.1Pr:YAP crystal by LD end-pumping. • ∼2.7 μm laser power can be improved by optimizing the concentrations of deactivating Pr3+. High-quality Er,Pr:YAP crystals with two different Pr3+ concentrations are grown successfully, and the spectra and laser performances are studied in contrast. Both two crystals exhibit a wide absorption band with a central wavelength at 972 nm and high transmittance of over 80% in the wavelength range of 2.5 to 5 μm. The luminescence and laser properties are improved when the concentration of Pr3+ decreased from 0.2 at% to 0.1 at%. The maximum powers of 1040 and 835 mW are achieved in the Er,0.1Pr:YAP, and Er,0.2Pr:YAP crystals, corresponding to slope efficiencies of 13.97% and 10.94%, respectively. All the results indicate that co-doping with an appropriate concentration of deactivating Pr3+ is an effective method to attenuate the self-termination effect of Er3+, and then further improve the laser performance. [ABSTRACT FROM AUTHOR]

Five substituted gadolinium gallium garnet crystals with different Ca2+/Mg2+/Zr4+ stoichiometric ratio concentrations (Zr4+: 13.0, 15.0, 15.3, 16.3, 19.5 at.%, as well as increasing Ca2+ and Mg2+ concentrations in proportion) were grown by Czochralski technique. Their structure, defect, thermal and optical properties were comparatively studied and analyzed. The lattice parameters are achieved to be 12.47–12.54 Å which are 0.7–1.2 % larger than that of Gd 3 Ga 5 O 12. A linear equation with Zr4+ concentration is fitted to adjust the lattice parameter for demand. X-ray rocking curves with narrow FWHMs of 1.67′, 1.97′, 1.75′, 2.12′, 2.99′, respectively, indicating high crystalline quality when the Zr4+ concentration is below 16.3 at.%. The dislocation densities are 62, 47, 63, 315 and 3184 cm−2, suggesting the value increases rapidly when the Zr4+ concentration exceeds 16.3 at.% due to large lattice distortion. The thermal expansion coefficients are about 8.55 × 10−6 to 8.72 × 10−6 K−1, respectively. All the transmittances are above 80 % from visible to infrared wavelengths, and Sellmeier coefficients of refraction index equation were fitted, which is benefit for CaMgZr:GGG as substrate and optics application. The above results suggest that a more suitable substrate can be obtained for the series YIG magnetic-optic thin films by optimizing the Ca2+/Mg2+/Zr4+ concentrations. ● Five SGGG single crystals with different Ca2+/Mg2+/Zr4+ concentrations were successfully grown by Cz method. ● Relationship of concentrations and lattice constants can be described by fitting equation to adjust lattice parameter better. ● The Ca2+/Mg2+/Zr4+ concentrations have significative effect on crystalline quality, dislocation density and thermal expansion. ● Experimental refractive index and energy gaps data for different SGGG single crystals are provided. ● Potential and economic application value of SGGG in laser gain medium or substrate for series YIG magneto-optical thin films. [ABSTRACT FROM AUTHOR]

In this paper, we study an on-line scheduling problem that is motivated by applications such as carpooling. The ride requests arrive on-line over-list and specify the service locations (among m locations). The goal is to determine a schedule that maximizes the number of satisfied requests using k servers. We consider two variants of the problem with respect to constraints on the service location: in the monotone service direction variant, the service locations of the requests assigned to a server must be monotonic; in the strict monotone service direction variant, the service locations must be strictly monotonic. We present lower bounds on the competitive ratio for both variants. For the monotone service direction variant, we give an optimal straightforward algorithm if k ≥ m and we prove that no deterministic on-line algorithm can achieve a constant competitive ratio if k < m. For the strict monotone service direction variant, we give a lower bound max ⁡ { 2 (m − 1) m , 1 } on the competitive ratio of barely deterministic algorithms if k > 2 , and a lower bound of max ⁡ { m 2 , 1 } if k ≤ 2. We propose a Balanced Interval Algorithm for the strict monotone service direction variant if k > 2 and report some numerical experiments to evaluate the efficiency of this algorithm. • We introduce two on-line algorithm problems with monotone service direction constraints which are applied for carpooling system. • We discuss the lower bounds and upper bounds of these two problems. • We propose a balanced interval algorithm and measure the algorithm performance with numerical experiments. [ABSTRACT FROM AUTHOR]

In this study, the effects of dicyclohexylcarbodiimide (DCC) and disodium succinate (DS) treatments on the pericarp browning (PB) development in postharvest longan were elucidated by measuring PB-related phenotypes and the metabolisms of antioxidants, membrane lipids, and phenolics. Compared to the control, DCC-treated longan displayed the higher levels of PB index, CMP, ROS, PA, DAG, and SFAs, the higher activities of POD, PPO, and MLMEs including PLD, PC-PLC, PI-PLC, lipase, and LOX, and the higher expression levels of DlPPO1 , DlPOD1 , and genes encoding MLMEs. In contrast, the lower levels of chromaticity values, pigments, TP, PC, PI, and USFAs, the lower activities of RSEs including SOD, CAT, and APX, the lower expression levels of genes encoding RSEs, and a lower non-enzymatic antioxidant capacity were also noted in DCC-treated longan. These results imply that the exacerbated PB induced by DCC was associated with the activation of MLMEs by up-regulating the expression of genes encoding MLMEs, which expedited the damage of cell membrane. This membrane damage was also regulated by the accelerated accumulation of ROS triggered by DCC. The increased membrane permeability after the damage prompted an enzymatic oxidation between phenol oxidase and phenolics. However, the opposite effect occurred in the DS-treated longan. • DCC accelerated pericarp browning, but DS delayed pericarp browning in fresh longan. • DCC lowed antioxidant ability, but DS raised antioxidant ability in longan pericarp. • DCC induced ROS accumulation in longan pericarp, but DS showed the reverse effects. • DCC promoted cell membrane damage of longan pericarp, but DS retarded this damage. • DCC raised phenolics oxidation in longan pericarp, but DS delayed this process. [ABSTRACT FROM AUTHOR]