Simultaneous Design of Parallel Distributed Output Feedback and Anti‐windup Compensators for Constrained Takagi‐Sugeno Fuzzy Systems

This paper is devoted to developing a novel approach to deal with constrained continuous‐time nonlinear systems in the form of Takagi‐Sugeno fuzzy models. Here, the disturbed systems are subject to both input and state constraints. The one‐step design method is used to simultaneously synthesize the dynamic output feedback controller and its anti‐windup strategy. A parameter‐dependent version of the generalized sector condition is used together with Lyapunov stability theory to derive linear matrix inequality design conditions. Based on this result and for different design specifications, the synthesis of an anti‐windup based dynamic output feedback controller is expressed on the form of convex optimization problems. A physically motivated example is given to illustrate the effectiveness of the proposed method.     

Hydrothermal and Pyrolytic Conversion of Biomasses into Catalysts for Advanced Oxidation Treatments

Biomasses are very important natural products. Transferring biomass into catalysts for the advanced oxidation process (AOP) via heat treatment has attracted extensive attention. This review systematically introduces and summarizes two kinds of innovative biomass-based catalysts according to the treating temperature. At low temperature ( < 300  ° C), biomasses are converted into hydrothermal carbonation carbon (HTCC) with semiconductive properties for photocatalysis application. At high temperature ( > 300  ° C), by contrast, the products lose their semiconductive nature and become a conductive carbon-based conductor (biochar). They usually work as AOP catalysts by activating oxidant of O₂, H₂O₂, and peroxysulfate for environmental treatment. This review summarizes and compares HTCC and biochar according to their formation process, structure, catalytic mechanism, and key points for the activity enhancement. The active units in HTCC are the sp²-hybridized polyfuran unit while those in biochar are the persistent free radicals, nitrogen-containing unit, or defects. HTCC converts water into OH radicals by using the photoexcited electron/hole pairs induced by solar illumination, while biochar activates oxidants via the active unit on its surface. More importantly, this review summarizes and demonstrates the key points to obtain high-efficiency HTCC and biochar catalysts. Finally, conclusions are drawn and the future aspects for biomass-based catalysis are given.     

Do whatever works: A robust approach to fault-tolerant autonomous control

This paper describes a highly distributed fault-tolerant control system capable of compensating for deficiencies in system-level performance even when the cause of a fault cannot be explicitly identified. Developed for an autonomous underwater vehicle that must remain operational for several weeks without human intervention, this system must be capable of dealing with events that cannot be anticipated at design time. A unique aspect of this system is that it handles such events by attempting to do whatever works if it is unable to diagnose and correct specific faults. The software architecture used in this approach is applicable to a wide range of complex autonomous control applications.     

Nb-Mediated Grain Growth and Grain-Boundary Engineering in Mg3Sb2-Based Thermoelectric Materials

The poor carrier mobility of polycrystalline Mg₃Sb₂ at low temperatures strongly degrades the thermoelectric performance. Ionized impurities are initially thought to dominate charge carrier scattering at low temperatures. Accordingly, the increased electrical conductivity by replacing Mg with metals such as Nb is also attributed to reduced ionized impurity scattering. Recent experimental and theoretical studies challenge this view and favor the grain boundary (GB) scattering mechanism. A reduction of GB scattering improves the low-temperature performance of Mg₃(Sb, Bi)₂ alloys. However, it is still elusive how these metal additions reduce the GB resistivity. In this study, Nb-free and Nb-added Mg₃Sb₂ are studied through diffraction, X-ray absorption spectroscopy, solid-state nuclear magnetic resonance spectroscopy, and atom probe tomography. It is shown that Nb does not enter the Mg₃Sb₂ matrix and remains in the metallic state. Besides, Nb diffuses along the GB forming a wetting layer, which modifies the interfacial energy and accelerates grain growth. The GB resistivity appears to be reduced by Nb-enrichment, as evidenced by modeling the electrical transport properties. This study not only confirms the GB scattering in Mg₃Sb₂ but also reveals the hitherto hidden role of metallic additives on enhancing grain growth and reducing the GB resistivity.     

An Exceptionally Selective DNA Cooperatively Binding Two Ca2+ Ions

Ca²⁺ is a highly important metal ion in biology and in the environment, and thus there is extensive work in developing sensors for Ca²⁺ detection. Although many Ca²⁺‐binding proteins are known, few nucleic acids can selectively bind Ca²⁺. DNA‐based biosensors are attractive for their high stability and excellent programmability. We report a RNA‐cleaving DNAzyme, EtNa, cooperatively binding two Ca²⁺ ions but to only one Mg²⁺. Four DNAzymes with known Ca²⁺‐dependent activity were compared, and the EtNa had the best selectivity for Ca²⁺. The EtNa is 90 times more active in Ca²⁺ than in Mg²⁺. Phosphorothioate (PS) modification showed that both non‐bridging oxygen atoms at the scissile phosphate contribute equally to Ca²⁺ binding. The pH–rate profile suggests two concurrent deprotonation reactions. EtNa was further engineered for Ca²⁺ sensing, and found to have a detection limit of 17 μm Ca²⁺ and excellent selectivity. The detection of Ca²⁺ in tap water was performed, and the result was comparable with that by ICP‐MS. This study offers new fundamental insights into Ca²⁺ binding by nucleic acids and improved metal selectivity by having multiple cooperative metal binding sites.     

Digestion of pre‐treated food waste in a hybrid anaerobic solid–liquid (HASL) system

The hybrid anaerobic solid–liquid (HASL) system was developed to be used in industrial‐scale operations to minimize the amount of food waste for disposal in Singapore. Thermal pre‐treatment of food waste at 70 °C for 2 h (experiment E1) or at 150 °C for 1 h (experiment E2) facilitated the hydrolytic and acidogenic processes in the acidogenic reactor and methanogenesis in the methanogenic reactor in the HASL system. The highest dissolved chemical oxygen demands in the effluents from the acidogenic reactors were 17 575, 19 980 and 24 235 mg dm^?3 in the control with food waste without thermal pre‐treatment and experiments E1 and E2, respectively. The maximum concentrations of methanogens in the methanogenic reactor were 2.3 × 10⁷, 3.8 × 10⁷, 4.3 × 10⁷ cells cm^?3 for the control and experiments E1 and E2, respectively. However, the performances of the methanogenic phase in terms of specific activity of methanogens did not differ significantly for the control and experiments E1 and E2. Use of thermally pre‐treated food waste halved the time to produce the same quantity of methane in comparison with anaerobic digestion of fresh food waste. The fluorescent measurements of co‐enzyme F₄₂₀ and oligonucleotide probe Arc915 specifically bound (hybridized) with 16S rRNA were used for monitoring of methanogens during anaerobic digestion of food waste. There was a linear correlation between these parameters and the concentration of methanogens in the effluent from the methanogenic reactor. Copyright © 2005 Society of Chemical Industry     

Effect of fish oil on cancer cachexia and host liver metabolism in rats with prostate tumors

The aim of this study was to investigate whether tumor-induced cachexia and aberrations in host liver metabolism, induced by the MAT-LyLu variant of the Dunning prostate tumor, could be prevented by ω3 fatty acids from fish oil. On day 0, adult Copenhagen-Fisher rats fed normal chowad libitum were inoculated with 10⁶ MAT-LyLu cells (n=14) or saline (n=9). On day 7, when tumors were palpable, four tumor-bearing (TB) and four nontumorbearing (NTB) rats were put on isocaloric diets with 50% of total energy as fish oil. The introduction of fish oil-enriched diets caused a reduction in energy intake to less than half of the energy intake by animals fed normal diets during days 7–14 (difference by dietary group: NTB,P<0.001; TB,P<0.001). During days 14–21, energy intake in fish oil-fed animals returned to approximately 75% of energy intake by animals fed normal diets (difference by dietary group: NTB,P<0.003; TB,P=0.001). Carcass weight of animals on day 21, when the study was terminated, was significantly related to initial weight (P=0.05) and mean food intake during the study (P=0.01). When data were adjusted for these variables using analysis of covariance, with NTB animals on normal diets being the reference group, significant loss of carcass weight was observed in TB animals on normal diets only (mean ±SEM 58±10 g loss,P<0.001), but not in TB animals on fish oil diets (8±18 g loss,P=0.67). This positive effect of fish oil diets on carcass weight in TB animals was statistically significant (50±19 g,P<0.02), implicating that the fish oil enriched diet inhibited tumor-induced weight loss by more than 85%. No effect of fish oil diets on tumor growth was detected. In all TB animals, regardless of diet, hepatic [P_i]/adenosine triphosphate] ratios measured by³¹P magnetic resonance spectroscopy (MRS)in vivo andin vitro were elevated, and absolute concentrations of phosphocholine, glycerophosphocho-line, glycerophosphoethanolamine and glucose-6-phosphate as determined by³¹P MRSin vitro were reduced. Ultrastructural studies of liver tissue revealed increased numbers of mitochondria and increased amounts of endoplasmic reticulum in the host liver of TB animals, without differences between dietary group. In conclusion, fish oil supplementation partially inhibited MAT-LyLu tumor-induced cachexia, but did not prevent the majority of³¹P MRS-detectable alterations in host liver metabolism.     

High performance encapsulation structures utilizing Russian Doll architectures

A Russian Doll encapsulation architecture utilizing pairs of free-standing barrier films and epoxy seals separated by nitrogen spacers is presented, enabling the use of low-cost epoxy to attach two or more free-standing barrier films to a substrate with improved barrier performance. The performance of various Russian Doll encapsulations was evaluated with the calcium thin film optical transmission test, showing improved performance of the Russian doll configuration relative to a non-nested barrier/spacer architecture, and demonstrating that water vapor transmission rates (WVTR) of 0.00021 g/(m², day) or below can be achieved with low-cost materials in this architecture. This WVTR correlates to a predicted lifetime of more than 10 years for bulk heterojunction solar cell modules fabricated and tested by Konarka Technologies (Lowell, MA, USA).     

An automatic controller extractor for HDL descriptions at the RTL

Extracting controlling finite-state machines can significantly reduce state space and thereby speed functional verification. The controller extraction algorithm uses an approach that frees it from restrictions on HDL code writing style