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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]

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]

• 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]

• 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]

• 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]

A novel structural composite (Fe-N/FeS@C) was synthesized via a self-doping strategy by the pyrolysis of a solid mixture of lignosulfonate and ferric nitrate pretreated by mechanical activation. The as-synthesized composite contained 7.5 wt% of single atomic iron moieties and 16.0 wt% of encapsulated FeS nanoparticles, with a high surface area of 1095.81 m2 g–1 and plentiful micropores and mesopores (0.4–10 nm). The Fe-N/FeS@C composite was confirmed to possess outstanding catalytic activity for sulfite activation in the degradation of methylene blue, with a high reaction rate constant (0.77 g g–1 min–1) and long cycling stability (83.1% of initial activity retention after 10 recycles). Moreover, the composite exhibited satisfactory activity recovery via a simple rinsing process with ethanol and HCl, and performed well in a wide pH range of 3–11. Density functional theory calculation results further demonstrated that the reaction energy of the rate-determining step, in which SO 3 •− was produced from SO 3 2– on atomic Fe moieties, was lower than that of the formation of FeSO 3 + by Fe3+ and SO 3 2–. The excellent performance of Fe-N/FeS@C was mainly attributed to the combination of the high mass loading of active sites of atomic Fe moieties anchored into carbon matrix with encapsulated FeS nanoparticles. This study provides new insight into the development of environment-friendly, stable and atomic dispersion iron composite for sulfite activation to efficiently remove organic pollutants. [Display omitted] • A composite (Fe-N/FeS@C) was developed by MA and pyrolysis technology. • Activation of sulfite using the composite exhibits a superior catalytic activity. • Both SO 4 •− and •OH are identified as the main reactive oxygen species. • Single atomic irons and encapsulated FeS in the catalyst are key active sites. [ABSTRACT FROM AUTHOR]

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]

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]

• Cr,Er:YSGG crystal with thermal bonding and concave end-face is pumped by Xenon lamp. • Thermal distribution simulation shows thermal bonding can improve heat dissipation capability. • Thermal focal length indicates concave end-face can compensate thermal lens effect. • High single pulse energy of 3.48 J obtained for the concave thermal bonding Cr,Er:YSGG at 5 Hz. • Maximum energy of 1.155 J and slope efficiency of 3.65 % are achieved for the concave thermal bonding Cr,Er:YSGG at 20 Hz. We demonstrate the influence of thermal bonding and concave end-face on the 2.79 μm laser performance of Cr,Er:YSGG crystal. The simulation results of temperature distribution suggest that the two pure YSGG crystals bonded on the Cr,Er:YSGG as end-caps are beneficial to improve the heat dissipation capability. The experimental results of thermal focal length show that the thermal effects of un-bonding, planar thermal bonding, and concave thermal bonding Cr,Er:YSGG crystals are in descending tendency. The maximum output energies and slope efficiencies for concave thermal bonding Cr,Er:YSGG crystal are 3.480 J, 3.33 %@5 Hz; 2.126 J, 3.65 %@10 Hz; 1.384 J, 3.63 %@15 Hz; 1.155 J, 3.65 %@20 Hz, respectively, and the beam quality factors M x 2/ M y 2 are determined to be 7.68/8.63. The result is much better than the previous work, indicating that the xenon lamp pumped concave thermal bonding Cr,Er:YSGG crystal is a promising method to realize high energy laser output. All the results indicate that the thermal bonding and concave end-faces are promising methods to reduce the thermal effect and improve the laser performance of Cr,Er:YSGG crystal pumped by the xenon lamp. [ABSTRACT FROM AUTHOR]

The efficient removal of oil droplets and particles from volumes of a stable emulsified oil-contaminated polymer-flooding wastewater has been an interesting yet challenging research topic within the oilfield. In this work, a highly efficient composite flocculant (PAC-PSi-PDMDAAC) was prepared by modifying activated silicic acid onto polyaluminium chloride (PAC) through Si-O-Al bond firstly and then combined with polydimethyldiallyl ammonium chloride (PDMDAAC) by physical blending, the preparation conditions and the flocculation parameters that influence of the turbidity removal and oil removal were experimentally investigated. The optimal conditions are shown as follows: pH= 3.04, PAC/PSi = 5:1, PAC/PDMDAAC = 1:0.3. The characterization of composites were analyzed by Fourier infrared (FTIR), Thermogravimetry (Tg) and Static light scattering (SLS). The results revealed that PAC underwent the addition of PSi and PDMDAAC to form high-polymeric species. In addition, the formation of more denser flocs in wastewater treatment was affirmed with scanning electron microscope (SEM) analysis. The flocculation experiments results showed that the maximum turbidity removal rate and oil removal efficiency for polymer-flooding wastewater could reached 98.3% and 91.3% at dosage of 120 mg/L, respectively, and its flocculation efficiency was much better than that of flocculants (PAC, PAC-PSi and PAC-PDMDAAC), which confirmed the synergistic enhancement of performance of PAC by PSi and PDMDAAC. However, the Zeta potential results indicated that the maximum Zeta potential value of PAC-PDMDAAC treatment was not beneficial for oil and particles removal, which indicated the adsorption bridging effect of lager aggregates played a most significant role in the flocculation process. And this newly synthesized PAC-PSi-PDMDAAC would be a promising flocculant for polymer-flooding oily wastewater treatment to reduce oil and particulate matters. [Display omitted] [ABSTRACT FROM AUTHOR]

• High-quality Ho:YAP crystal was fabricated by the Czochralski method. • The structure, spectroscopy and J-O parameters of Ho:YAP were discussed. • For the first time, ∼3 μm CW laser was realized in single Ho-doped crystal host. • Maximum power of 176 mW and slope efficiency of 3.36% was obtained. We demonstrate the spectroscopy and mid-infrared laser performance on the Ho:YAP oxide crystal grown by the Czochralski method in detail. The crystal belongs to orthorhombic system of Pnmb (62) space group and shows high crystalline quality. The lifetimes of 5I 6 and 5I 7 levels are 0.412 and 4.485 ms, respectively. Particularly, under 1150 nm Raman fiber laser pumping, a 3.01 μm CW laser with a maximum power of 181 mW and slope-efficiency of 3.35% is achieved. The M2 factor of 1.35/1.37 indicates that the yield laser has excellent beam quality. The results reveal that the Ho:YAP crystal possesses great potential for developing efficient 3.0 μm mid-infrared lasers. [ABSTRACT FROM AUTHOR]

• Cascade Er:YSGG crystal pulsed lasers near 1.6 and 2.8 μm are realized at room temperature. • The slope efficiency of MIR laser increases to 4.2 % from 1.9 % by cascade process. • Four laser wavelengths of 2.793, 2.821, ∼2.860, 2.917 μm in Er:YSGG laser are discovered. • The cascade process can improve the MIR laser performance based on the Er:YSGG crystal. We demonstrate a pulsed cascade laser on LD end-pumped Er:YSGG crystal near 1.6 and 2.8 μm at room temperature for the first time. The slope efficiency of mid-infrared laser with the assistance of cascade process is significantly improved. Under the working frequency of 100 Hz and pump pulse width of 6 ms, a maximum power of 243 mW centered at 2.79 μm is achieved with increasing slope efficiency of 4.2 %, while the slope efficiency of non-cascade is only 1.9 %. Under high pump power, four laser wavelengths of 2.793, 2.821, ∼2.860, and 2.918 μm are discovered and the phenomenon is explained according to the Boltzmann factors. This work would be conducive to the exploration of pulsed cascade laser based on the Er:YSGG crystal. [ABSTRACT FROM AUTHOR]