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Hierarchical silicon nitride (Si 3 N 4) membranes were fabricated by catalytic growth of α-Si 3 N 4 nanowires onto the rod-like β-Si 3 N 4 grains. Compared to the bare asymmetric structure of β-Si 3 N 4 membranes, the average pore size reduced from 0.9 µm to 0.67 µm, while the porosity decreased slightly from 47 ± 0.6% to 45.3 ± 1.1%. Inorganic nanoparticles derived from organosilane were used to further modify the membranes. The membranes displayed super-hydrophobic characteristics with a water contact angle of 155 ± 1° due to the multilevel hierarchical structure and the -Si-CH 3 low energy terminal groups. The super-hydrophobic membranes were successfully applied for the water-in-oil emulsion separation process. At various driving pressures, the water rejection of the water-in-oil emulsion was higher than 95%. This work's durable super-hydrophobic ceramic membrane has promise for the purification of a variety of oil products. [Display omitted] [ABSTRACT FROM AUTHOR]

Robust super-hydrophobic ceramic membranes consisting of layered structure Si 2 N 2 O grains and organosilane-derived inorganic nanoparticles were successfully fabricated and employed for membrane distillation. First, phase inversion and sintering method were used to prepare porous Si 2 N 2 O membranes. The slurry composition and sintering temperature were optimized to obtain a pure phase Si 2 N 2 O membrane with high bending strength, tailored average pore size, and high permeability. Then, the Si 2 N 2 O membranes were modified with organosilane-derived inorganic nanoparticles through ammonolysis and pyrolysis reactions. Due to the micro and nano-hierarchical rough structures and the presence of -Si-CH 3 groups, the membranes showed super-hydrophobicity with a water contact angle of 152 ± 1°. Finally, the membranes were applied to desalinate seawater by sweeping gas membrane distillation. A stable water flux of 76 ± 0.9 L/(m2 day) with a salt rejection of > 99% was recorded during 30 h distillation test at 75 °C, demonstrating the stability and durability of the membranes. [Display omitted] • Layered structure Si 2 N 2 O membrane with naturally rough grains was fabricated. • Super-hydrophobicity was obtained after modifying by the inorganic nanoparticles. • The super-hydrophobic membrane has micro and nano-hierarchical rough structures. • The membrane was successfully employed in membrane distillation process. [ABSTRACT FROM AUTHOR]

Robust hydrophobic membranes are promising for effective separation of water-in-oil emulsion, which is becoming extremely critical challenge in many sectors, including oil refinery and petrochemical industries. In this paper, robust hydrophobic ceramic membrane was fabricated and successfully applied for the water-in-oil emulsion separation process. First, porous β-silicon nitride (Si 3 N 4) membranes with unique rod-like grains and three-dimensional network structure were fabricated. The preparation procedure was optimized considering the morphological properties, porosity, permeability and mechanical characteristics. Then, the optimized membrane was converted to a hydrophobic structure with water contact angle of 136.1°. The hydrophobic modification was achieved using organosilane pyrolysis coating method, which resulted in the formation of a robust inorganic-organic hybrid hydrophobic coating layer on the membrane structure. The hydrophobic membrane was employed for the separation of water-in-oil emulsion. At a feed pressure of 1 bar, a permeate flow of 80 L/m2 h with a water rejection of 94.3% was obtained. The presented hydrophobic silicon nitride membrane in this study is promising for a range of water-in-oil emulsion separation applications, particularly in harsh conditions. [Display omitted] • β-Si 3 N 4 membrane with three-dimensional network structure were fabricated. • The membrane was converted to a hydrophobic by inorganic-organic hybrid coating. • The coating layer contains covalent internal structure and -CH 3 terminal groups. • The coated membrane was successfully applied in separation of water-in-oil emulsion. [ABSTRACT FROM AUTHOR]

Abstract Morphological engineering of silicon nitride (Si 3 N 4) hollow fiber membrane was carried out by considering hydrodynamic viscous fingering phenomena, which govern the formation of the finger-like micro-voids layer in membranes. The influence of the solvent, the air gap, and the rate of internal coagulant on the finger-like/spongy layer thickness ratio, porosity, bending strength, pore size distribution, and water permeation, was thoroughly investigated. The viscosity of the suspension played an important role in the development of the microstructure. Membrane morphology can be controlled by optimizing fabrication parameters in order to achieve the desirable fiber structure for the final functional application. The membrane used in microfiltration tests was produced by using N-methyl-2-pyrrolidone (NMP) as a solvent, with an air gap of 5 cm, and an internal coagulant rate of 10 mL⋅min−1. The membranes comprised a selective finger void-free spongy layer on the outer surface, and displayed high permeation features. The membranes successfully treated highly concentrated (21000 ppm) oil-field-produced-water, and an oil rejection of 95% as well as a stable permeate flux of 480 L m−2 h−1 were achieved. Highlights • Viscous fingering phenomena allowed morphological control of Si 3 N 4 membranes. • The type of solvent, air gap, and internal coagulant rate were influential factors on membrane morphology. • The optimized Si 3 N 4 membranes were successfully used in microfiltration water treatment. [ABSTRACT FROM AUTHOR]

Abstract This paper addresses distributed mixed H 2 ∕ H ∞ sampled-data output feedback control design for a semi-linear parabolic partial differential equation (PDE) with external disturbances in the sense of spatial L ∞ norm. Under the assumption that a finite number of local piecewise measurements in space are available at sampling instants, a static sampled-data output feedback controller is suggested, where the sampling interval in time is bounded. The local piecewise measurements bring additional difficulty for the exponential stability and performance analysis since the existing Poincaré-Wirtinger inequality in 1D spatial domain is not applicable. By constructing an appropriate Lyapunov–Krasovskii functional candidate and employing Wirtinger's inequalities, a variant of Poincaré-Wirtinger inequality in 1D spatial domain, as well as Agmon's inequality, it is shown that the suggested static sampled-data output feedback controller not only guarantees the output exponential stability of the resulting closed-loop PDE in the spatial L ∞ norm but also ensures the mixed H 2 ∕ H ∞ performance index defined in the spatial L ∞ norm, if the sufficient conditions presented in terms of standard linear matrix inequalities (LMIs) are fulfilled. The satisfactory and better performance of the suggested sampled-data feedback controller is demonstrated by numerical simulation results of an illustrative example. [ABSTRACT FROM AUTHOR]

Highlights • Aroma losing in 'Nanguo' pears was closely related to LOX and ethylene-related pathway. • Preharvest CaCl 2 treatment inhibited aroma losing in 'Nanguo' pears during shelf life after refrigerated storage. • Preharvest CaCl 2 treatment can kept higher expression level of aroma-related genes in LOX and ethylene-related pathway. Abstract Refrigerated storage postponed the post-ripening of 'Nanguo' pears (Pyrusussuriensis Maxim.), but the aromatic esters of the pears were apt to weaken when the fruit was transferred to room temperature. CaCl 2 treatment, in which the pears were sprayed with 4% CaCl 2 during the days before harvest, inhibited the appearance of aromatic weakening of the postharvest pears after long-term refrigerated storage in the study. CaCl 2 -treated pears presented higher respiration rate, ethylene production and aliphatic acids during ripening in shelf life at room temperature. Higher genes expression of lipoxygenase (LOX), and hydroperoxide lyase (HPL), which were associated with LOX pathway, were found in the CaCl 2 -treated fruit during the ripening in shelf life. The expression levels of genes ACS, ACC, PuEIN4 and PuEIN2 were up-regulated, which were related to ethylene-related pathway. These results demonstrated that the aroma weakening of 'Nanguo' pears can be effectively inhibited by CaCl 2 treatment and the potential inherent mechanisms are discussed. [ABSTRACT FROM AUTHOR]

Abstract This paper reports on the successful fabrication of γ-Y 2 Si 2 O 7 membranes with low thermal conductivity, which is an important membrane property for achieving high performance in membrane distillation process. Single-phase γ-Y 2 Si 2 O 7 powder was first synthesized by calcination of SiO 2 and Y 2 O 3 powders, with 3 wt% LiYO 2 as a sintering aid. The membrane was produced by tape-casting of a suspension of this powder. After sintering at 1300 °C for 4 h, a flat membrane was obtained, which had a thickness of 0.5 mm, 49% porosity, 0.9 μm pore diameter, and low thermal conductivity of 0.497 W/m⋅K at 32 °C, and 0.528 W/m⋅K at 100 °C. The obtained membrane presented hydrophobic features (water contact angle was 132°) after surface modification, which resulted in formation of a strongly adhered robust hydrophobic SiNCO nanoparticle layer on its surface. The resultant hydrophobic membrane was tested in water desalination experiments using a sweeping gas membrane distillation (SGMD) device. High water flux of 10.07 L⋅ m−2⋅ h−1 was achieved for a 20 wt% NaCl feeding solution and a temperature at the feed of 90 °C. Stable water flux and rejection rates were recorded in long-term experiments (>400 h). [ABSTRACT FROM AUTHOR]

Highlights • Browning in 'Nanguo' pears was closely related to the membrane metabolism. • CaCl 2 treatment inhibited browning in 'Nanguo' pears during shelf life after refrigerated storage. • Changes in enzymes of activity and expression involved in membrane metabolism were studied. Abstract The post-harvest ripening of 'Nanguo' pears (Pyrus ussuriensis Maxim.) can be effectively postponed by refrigerated storage. However, peel browning (PB) often appears in the pears after refrigerated storage during the shelf life at room temperature. In order to find an effective method to relieve PB of pears, 2% CaCl 2 was used to treat the fruit after low temperature. In the study, CaCl 2 treatment on the pears has efficiently restrained the appearance of PB. Higher firmness and polyphenol content were detected in CaCl 2 -treated fruit during the shelf life. Electrolyte leakage and malondialdehyde (MDA) concentration were lowered in CaCl 2 -treated fruit. Gene expression levels of phospholipase D (PLD) and polyphenol oxidase (PPO) were inhibited by CaCl 2 treatment, and the activities of PLD and PPO were lower in CaCl 2 -treated fruit. The activity and gene expression of superoxide dismutase (SOD) were promoted under CaCl 2 treatment. Consequently, CaCl 2 treatment effectively alleviated the PB appearance of 'Nanguo' pears after refrigerated storage during the shelf life at room temperature and brown-related genes are regulated by CaCl 2 to varying degrees, which can help improve the quality of postharvest pears undergoing long term refrigeration and gene modification of brown pears. [ABSTRACT FROM AUTHOR]

The postharvest ripening and senescence of ‘Nanguo’ pears ( Pyrus ussuriensis Maxim. ) can be effectively delayed by low temperature storage. However, peel browning (PB) often occurs in pear fruit during shelf life at room temperature. In this study, ATP treatment on ‘Nanguo’ pears has efficiently inhibited the occurrence of PB. Higher flesh firmness, ATP concentration and energy charge (EC) were detected in ATP-treated fruit during shelf life. Malondialdehyde (MDA) concentration and electrolyte leakage were lowered in ATP-treated fruit. Gene expression levels of ATP synthase ( ATPase ), NADH dehydrogenase ( NDA ) and vacuolar proton-inorganic pyrophosphatase ( VPP ) were promoted by ATP treatment, and the activities of ATPase , NDA and VPP were higher in ATP-treated fruit. The elevated activity and gene expression of phospholipase D ( PLD ) were restrained under ATP treatment. ATP treatment effectively alleviated the PB of ‘Nanguo’ pears and the possible mechanisms were discussed. [ABSTRACT FROM AUTHOR]

Refrigeration delayed the ripening of ‘Nanguo’ pears ( Pyrusussuriensis Maxim.), but the aroma of the pears was apt to fade when the fruit was transferred to room temperature. ATP treatment, in which the pears were exposed to 1 mol/L ATP for 2 h on the day of removal from refrigeration for 150 d, alleviated the occurrence of aroma fading of the pears in this study. ATP-treated pears showed higher firmness, TSS, ethylene production, and respiration rate during the whole shelf life. Increasing ATP concentration and energy charge (EC) were found in ATP-treated fruit. The concentration of fatty acids was higher in the ATP-treated fruit. Higher enzymes activities and genes expression of transcripts for lipoxygenase ( LOX ), alcohol dehydrogenase ( ADH ), and alcohol acyltransferase ( AAT ), which were associated with LOX pathway, were detected in the treated fruit during the shelf life. These results indicated that the aroma fading of ‘Nanguo’ pears can be effectively alleviated by ATP treatment and the possible inherent mechanisms are discussed. [ABSTRACT FROM AUTHOR]

The red-emitting Sr[LiAl 3 N 4 ]:Eu 2+ (SLA) phosphor was synthesized under flowing N 2 gas. A thin organosilica layer (about 5–10 nm) was coated on the surface of SLA phosphors by a very simple method, which transformed the phosphor surface from hydrophilicity to hydrophobicity. The contact angle of water droplets on the surface of the packed SLA phosphors was more than 140°. Compared with the unmodified sample, the modified SLA phosphors could keep at a high emission intensity for more than twice the time under an extremely high moisture level (at relative humidity of 100%, 85 °C). The hydrophobic modification could also improve the uniform dispersion of phosphors during assembly process of white LED. [ABSTRACT FROM AUTHOR]

This paper deals with the problem of exponential stabilization for a linear distributed parameter system (DPS) using pointwise control and non-collocated pointwise observation, where the system is modeled by a parabolic partial differential equation (PDE). The main objective of this paper is to construct an output feedback controller for pointwise exponential stabilization of the linear parabolic PDE system using the non-collocated pointwise observation. The observer-based output feedback control technique is utilized to overcome the design difficulty caused by the non-collocation pointwise observation. We construct a Luenberger-type PDE state observer to exponentially track the state of the PDE system. A collocated pointwise feedback controller is proposed based on the estimated state. A variation of Poincaré – Wirtinger inequality is derived and the spatial domain is decomposed into multiple sub-domains according to the number of the actuators and sensors. By using Lyapunov’s direct method, integration by parts, and the variation of Poincaré – Wirtinger inequality at each sub-domain, sufficient conditions for the existence of the observer-based out feedback controller are developed such that the resulting closed-loop system is exponentially stable, and presented in terms of standard linear matrix inequalities (LMIs). Furthermore, the closed-loop well-posedness analysis is also provided by the C 0 -semigroup approach. Extensive numerical simulation results are presented to show the performance of the proposed output feedback controller. [ABSTRACT FROM AUTHOR]

As a thermal energy storage medium (TESM) at moderate-high temperature of concentrating solar power (CSP), the molten NaCl-MgCl 2 has sharp corrosive action on a metal container. The influence of MgCl 2 content on a metal corrosion behavior is not clear. The corrosion behavior of a Fe based alloy (GH1140) in molten NaCl-MgCl 2 (at 1123 K) with different content of MgCl 2 (wt%：0.0，48.9，61.0，93.6) were studied by the submergence corrosion experience. Results show that: after corrosion for 5 h, there is a negative correlation between the weight loss of samples and the content of MgCl 2 . In the molten salt without MgCl 2 , the sample was corroded according to the mechanism of “dissolution as anode- oxidizing- peeling off of oxide film”. After adding a little MgCl 2 in the molten salt, an unprotected MgO shell was formed on the sample surface. The samples weight decreased and obeyed a line law. The elements of Fe and Cr deplete in the corrosion layer. Corrosion mechanism is “dissolution as anode- oxidizing- reduction- chlorination”. When the content of MgCl 2 is very high in the molten salt, partial pressure of Cl 2 increases. The corrosion mechanism is similar to what in the molten salt with a little MgCl 2 , but the chlorination reaction is more severe. [ABSTRACT FROM AUTHOR]

As a solar energy storage medium at moderate-to-high temperature, molten chlorate severally corrodes metal vessels. The corrosion behavior and mechanisms of pure nickel (Ni), GH4033 and GH4169 in 793 K molten eutectic NaCl-MgCl 2 were studied. During the initial stage of corrosion, pure Ni and GH4033 gain weight from the many plate-like shells formed on the sample surface. After corrosion for 40 h, all sample surfaces were rather porous and loosened. MgO nuclei that were attached to the loosened microstructure surface fell off with the microstructures, which led to a continual decrease in the sample weight. The three sample surfaces were mainly composed of MgO and Ni or (Ni, Fe) from the sample substrate. Al and Ti were preferentially oxidized and stably excited on the GH4033 surface, which inhibits the corrosion process. The corrosion rate of GH4169 was the highest for the δ phase, which is rich in Nb, and phase boundaries were corroded preferentially. In the anode reaction, metal atoms escape from the corrosion system in the form of chlorides or aqueous chlorides. [ABSTRACT FROM AUTHOR]

Zeolitic imidazolate frameworks (ZIFs) have attracted great attention due to their potential applications in gas adsorption, catalytic membrane reactors, chemical sensing and gas separation. To achieve the massive industrial application, a number of attempts have been made to prepare supported-ZIF membranes. We successfully synthesized a well-intergrown continuous ZIF-8 membrane on the outer surface of silicon nitride hollow fibers by a one-step hydrothermal method. Through controlling ZIF-8 nucleation and growth rates, the membranes were compact and well-coated. Single gas permeation of H 2 , N 2 and CO 2 at 25 °C, 0.25 MPa indicated the sieving behavior of the obtained membranes. N 2 permeance did not change with permeation time, while H 2 permeance increased in the beginning and keep steady at 8.35×10 −7 mol/m 2 Pa s due to the high storage properties of ZIF-8, and CO 2 permeance decreased in the first hour, then maintained at 1.15×10 −7 mol/m 2 Pa s due to the strong CO 2 adsorption in the ZIF-8 and the cooperative interactions of adsorbed CO 2 molecules with CO 2 passing through. The H 2 /CO 2 separation factor of 11.67 could be achieved in the separation of 50%H 2 /50%CO 2 mixture. [ABSTRACT FROM AUTHOR]

Novel microporous β-Sialon (Si 6– z Al z O z N 8– z , z = 1–4) ceramic hollow fiber membranes have been successfully prepared by a combined phase-inversion and sintering method. The influence of dispersant concentrations on the viscosity curve was first studied to obtain a stable precursor suspension. Different z value and sintering temperature were studied to get asymmetric hollow fibers with a good combination of high bending strength (369 MPa), suitable pore size (0.8 μm), large gas and water flux, which are suitable for membrane distillation (MD). The membranes also exhibited a much lower thermal conductivity. After modified to hydrophobic by grafting fluoroalkylsilane (FAS), the membranes were applied to vacuum membrane distillation (VMD) and direct contact membrane distillation (DCMD). They exhibited satisfactory water flux and a salt rejection rate of 99–100% for both methods. Most importantly, the permeate flux in DCMD reaches 63% of that in VMD due to the lower thermal conductivity, indicating their potential industrial applications. [ABSTRACT FROM AUTHOR]

Localized drug delivery strategies for cancer therapy have been introduced for decades as a means of increasing drug concentration at tumor target site and minimizing systemic toxicities. In this paper, a combination of microspheres (MSs) and sucrose acetate isobutyrate (SAIB) in situ -forming implants (ISFIs) was evaluated for improving antitumor efficacy via intratumoral injection. Monodispersed cucurbitacin (Cuc)-loaded Poly (lactic-co-glycolic acid) (PLGA) MSs with mean diameter of about 5 μm were fabricated by Shirasu porous Glass (SPG) membrane emulsification technique, and their properties were investigated. The in vitro drug release pattern, antimelanoma efficiency, and drug distribution in tumor of three different intratumoral injection systems, that is, MSs, SAIB ISFIs, and combination of MSs and SAIB ISFIs (SAIB-MSs), was investigated. The Cuc-loaded MSs prepared by PLGA (LA/GA = 50:50, inherent viscosity = 0.87 dL/g), has an appropriate release pattern with lower initial burst and delayed drug release. SAIB-MSs have a much slower drug release rate than that of MSs or SAIB ISFIs. SAIB-MSs showed the best antitumor efficacy in melanoma-bearing mice model, and the results of drug distribution in tumor revealed that the incorporation MSs in SAIB solution obviously extended the residence of drug in tumor. The low Cuc concentration in tumor periphery region after intratumoral administration of SAIB-MSs demonstrated poor drug penetration of this system. For further improving the antitumor efficacy of intratumoral chemotherapy, elegant designing to carriers with both extended residency and wide drug distribution in tumor is needed. [ABSTRACT FROM AUTHOR]

This paper addresses the problem of feedback control design for a class of linear cascaded ordinary differential equation (ODE)–partial differential equation (PDE) systems via a boundary interconnection, where the ODE system is linear time-invariant and the PDE system is described by an Euler–Bernoulli beam (EBB) equation with variable coefficients. The objective of this paper is to design a static output feedback (SOF) controller via EBB boundary and ODE measurements such that the resulting closed-loop cascaded system is exponentially stable. The Lyapunov’s direct method is employed to derive the stabilization condition for the cascaded ODE–beam system, which is provided in terms of a set of bilinear matrix inequalities (BMIs). Furthermore, in order to compute the gain matrices of SOF controllers, a two-step procedure is presented to solve the BMI feasibility problem via the existing linear matrix inequality (LMI) optimization techniques. Finally, the numerical simulation is given to illustrate the effectiveness of the proposed design method. [ABSTRACT FROM AUTHOR]