Catalytic oxidation with Al-Ce-Fe-PILC as a post-treatment system for coffee wet processing wastewater

The effluent from the anaerobic biological treatment of coffee wet processing wastewater (CWPW) contains a non-biodegradable compound that must be treated before it is discharged into a water source. In this paper, the wet hydrogen peroxide catalytic oxidation (WHPCO) process using Al-Ce-Fe-PILC catalysts was researched as a post-treatment system for CWPW and tested in a semi-batch reactor at atmospheric pressure and 25 °C. The Al-Ce-Fe-PILC achieved a high conversion rate of total phenolic compounds (70%) and mineralization to CO(2) (50%) after 5 h reaction time. The chemical oxygen demand (COD) of coffee processing wastewater after wet hydrogen peroxide catalytic oxidation was reduced in 66%. The combination of the two treatment methods, biological (developed by Cenicafé) and catalytic oxidation with Al-Ce-Fe-PILC, achieved a 97% reduction of COD in CWPW. Therefore, the WHPCO using Al-Ce-Fe-PILC catalysts is a viable alternative for the post-treatment of coffee processing wastewater.     

Numerical conjugate air mixed convection/non-Newtonian liquid solidification for various cavity configurations and rheological models

Unsteady 2D natural convection/phase change of a non-Newtonian liquid inside a square container caused by external mixed convection of a Newtonian fluid with various cavity configurations has been studied numerically. Air was chosen as external cooling fluid and modified non-Newtonian water as the internal solidifying fluid. Conjugate convective fluid and heat transport, described in terms of non-linear coupled continuity, momentum, and energy equations, were solved by using the finite volume method with the SIMPLE algorithm. Effects of four external fluid inlet/outlet locations and four non-Newtonian rheological models were studied. Results for the time evolution of streamlines, isotherms and freezing curves are analyzed. The effect of the cavity inlet/outlet configuration on streamlines of the external fluid is remarkable, near the region close to the non-Newtonian liquid filled container.     

A hybrid multi-level optimization approach for the dynamic synthesis/design and operation/control under uncertainty of a fuel cell system

During system development, large-scale, complex energy systems require multi-disciplinary efforts to achieve system quality, cost, and performance goals. As systems become larger and more complex, the number of possible system configurations and technologies, which meet the designer’s objectives optimally, increases greatly. In addition, both transient and environmental effects may need to be taken into account. Thus, the difficulty of developing the system via the formulation of a single optimization problem in which the optimal synthesis/design and operation/control of the system are achieved simultaneously is great and rather problematic. This difficulty is further heightened with the introduction of uncertainty analysis, which transforms the problem from a purely deterministic one into a probabilistic one. Uncertainties, system complexity and nonlinearity, and large numbers of decision variables quickly render the single optimization problem unsolvable by conventional, single-level, optimization strategies.To address these difficulties, the strategy adopted here combines a dynamic physical decomposition technique for large-scale optimization with a response sensitivity analysis method for quantifying system response uncertainties to given uncertainty sources. The feasibility of such a hybrid approach is established by applying it to the synthesis/design and operation/control of a 5 kW proton exchange membrane (PEM) fuel cell system.     

Effects of calcium salts of fatty acids and proportion of forage in diet on ruminal fermentation and nutrient flow to duodenum of cows.

Four Holstein cows fitted with ruminal and duodenal cannulas were used in a 4 x 4 Latin square to investigate the effects of calcium salts of long-chain fatty acids (fat) and proportion of forage in diet on ruminal fermentation, flow of nutrients to the small intestine, and animal performance. Treatments, arranged in a 2 x 2 (fat x forage) factorial, were 1) low (50%) forage, no fat; 2) low forage, fat; 3) high (67%) forage, no fat; and 4) high forage, fat. Feeding fat decreased OM intake and OM truly digested in the rumen. Feeding high forage diets decreased intakes of OM and starch and increased intakes of ADF and NDF. Ruminal pH and ratio of acetate to propionate were increased with high forage diets compared with low forage diets. Feeding fat and different amounts of forage to cows did not alter the flows of NAN and microbial N to the duodenum or efficiency of microbial growth. Production of milk and 4% FCM and percentage of fat in milk were increased by feeding fat. Feeding high forage diets decreased milk production, increased percentage of fat in milk, increased the yield of fat, and caused no change in 4% FCM production. The percentage of protein in milk was decreased by feeding high forage diets and fat, but yield of milk protein was decreased only by feeding high forage diets to cows.     

Effect of temperature and water availability during late maturation of the soybean seed on germ and cotyledon isoflavone content and composition

BACKGROUND: Isoflavone content in soybean seeds is strongly influenced by both environment and genotype. However, little is known about the effect of environment and genotype on isoflavones in germ versus cotyledons. To determine the effect of temperature and soil moisture status during soybean seed development on seed isoflavone concentration and composition, a set of two French and three US cultivars of similar maturity were grown in the greenhouse. At the R6 growth stage, plants were subjected to one of three night/day temperature regimes (13/23°, 18/28° or 23/33 °C) in either optimal or sub‐optimal soil water conditions. RESULTS: In cotyledons, a three‐ to six‐fold variation in total isoflavone content was observed between the high and low temperature treatments, whereas the germ contents had less than a two‐fold variation. Soil water supply had less effect than temperature on the isoflavone contents and compositions. In both seed parts, the isoflavone concentrations were highly dependent on the cultivar. CONCLUSION: These results show that isoflavone content and composition in cotyledon and germ are unrelated and it should be possible to independently manipulate these seed traits through plant breeding and crop management systems. Copyright © 2007 Society of Chemical Industry     

Identifying and classifying Great Lakes ship transits using a state machine approach

Invasive, aquatic organisms have entered the North America Great Lakes from ships' ballast water, often originating from Europe. Current approaches for preventing the introduction of such organisms in ballast water include ballast water treatment (BWT) or ballast water exchange (BWE). This paper examines BWE, which is conducted in (1) waters >200 nautical miles (nm) from shore, or (2) waters >50?nm from shore and >200?m deep. We used historical records of ships transiting from Europe to the Great Lakes during one year (2014) to determine the duration (in days) that ships were within waters that met the criteria for BWE. Ship paths were classified based upon transitions between location-assigned “states” (e.g., from European waters across the North Atlantic Ocean to North America), and from these state transitions, four types of routes were identified. On average, ships sailing these routes had between 3.5 and 4.7 d to perform BWE in areas >200?nm from shore and 4.7 to 6.2 d when >50?nm from shore and >200-m deep water. Conducting BWE in daylight hours, if deemed necessary for safety, shortened the time window for BWE, especially in winter months, by approximately 50–70%. The state “machine” approach could, in the future, be used to identify ships from specific regions (e.g., ports within waterways at high risk of harboring potentially invasive species). Reshaping the definition of regional boundaries based upon time-of-year, water temperature, or other variables would further refine the ability to identify high-risk transits.     

Inactivation of Escherichia coli O157:H7 on surface-uninjured and -injured green pepper (Capsicum annuum L.) by chlorine dioxide gas as demonstrated by confocal laser scanning microscopy

Cells of Escherichia coli O157:H7 on uninjured and injured surfaces of green pepper were inactivated by 0·15–1·2 mg l⁻¹ClO₂gas treatments. A membrane-surface-plating method was used for resuscitation and enumeration of E. coli O157:H7 treated with ClO₂. The location and viability ofE. coli O157:H7 on uninjured and injured green pepper surfaces after ClO₂gas treatments were visualized using confocal laser scanning microscopy (CLSM). Live and dead cells of E. coli O157:H7 on pepper surfaces were labeled with a fluorescein isothiocyanate-labeled antibody and propidium iodide, respectively. A 7·27 log reduction of E. coli O157:H7 on uninjured green pepper surfaces was obtained with a 0·60 mg l⁻¹ClO₂gas treatment for 30 min at 20°C under 90–95% relative humidity. For injured surfaces, a 6·45 log reduction was achieved with a 1·2 mg l⁻¹ClO₂gas treatment. Each ClO₂gas treatment (0·15–1·2 mg l⁻¹ClO₂) for inoculated bacteria on uninjured surfaces showed significantly more reductions (1·23–4·24 log) than for those on injured surfaces (P<0·05). The microphotographs of CLSM showed that bacteria preferentially attached to injured surfaces and those bacteria could be protected from bacterial reduction by the injuries. This study indicates that ClO₂gas treatment can be a potential effective method of pathogen reduction for fresh fruits and vegetables.     

Multitoxin biosensor-mass spectrometry analysis: a new approach for rapid, real-time, sensitive analysis of staphylococcal toxins in food

Biomolecular interaction analysis mass spectrometry (BIA-MS) was applied to detection of bacterial toxins in food samples. This two-step approach utilizes surface plasmon resonance (SPR) to detect the binding of the toxin(s) to antibodies immobilized on a surface of a sensor chip. SPR detection is then followed by identification of the bound toxin(s) by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Staphylococcal enterotoxin B (SEB) was readily detected in milk and mushroom samples at levels of 1 ng/ml. In addition, non-specific binding of food components to the immobilized antibody and to the sensor chip surface was detected. To evaluate the applicability of BIA-MS in the analysis of materials containing multiple toxic components, sample containing both SEB and toxic-shock syndrome toxin-1 was analyzed. Both toxins were successfully and simultaneously detected through the utilization of multiaffinity sensor chip surfaces.     

防浪涌芯片不只是控制电流

许多电子系统必须保证不间断的、连续的工作.因此技术员们必须在不关闭电源的情况下向这些"高可用性的"系统中添加新的板卡,或者更换其中报废的及受损的板卡.不过,将板卡从通电的底板抽出,或者插入底板,都会带来问题.底板从本质上来说,往往等效于在板卡边缘连接器和电源的大容量电容间的大电感.如果通电的板卡与周围断开时,底板中会出现环振和高压尖峰.例如,在一个-48V的分布式系统中,拔走一块带电板卡会产生足以损伤连接器接触点的电弧.更糟糕的是,当插入新板卡、电压线刚一接触时,对板卡的大容量电容进行充电的、极大的底板电流会在周围电路上产生有害的瞬态浪涌.     

Free Energy Control of Charge Photogeneration in Polythiophene/Fullerene Solar Cells: The Influence of Thermal Annealing on P3HT/PCBM Blends

The function of organic solar cells is based upon charge photogeneration at donor/acceptor heterojunctions. In this paper, the origin of the improvement in short circuit current of poly(3‐hexylthiophene)/6,6‐phenyl C₆₁‐butyric acid methyl ester (P3HT/PCBM) solar cells with thermal annealing is examined. Transient absorption spectroscopy is employed to demonstrate that thermal annealing results in an approximate two‐fold increase in the yield of dissociated charges. The enhanced charge generation is correlated with a decrease in P3HT's ionization potential upon thermal annealing. These observations are in excellent quantitative agreement with a model in which efficient dissociation of the bound radical pair into free charges is dependent upon the bound radical state being thermally hot when initially generated, enabling it to overcome its coulombic binding energy. These observations provide strong evidence that the lowest unoccupied molecular orbital (LUMO) level offset of annealed P3HT/PCBM blends may be only just sufficient to drive efficient charge generation in polythiophene‐based solar cells. This has important implications for current strategies to optimize organic photovoltaic device performance based upon the development of smaller optical bandgap polymers.