Relationship concerning the nature and concentration of Fe(III) species on the surface of TiO2 particles and photocatalytic activity of the catalyst

There have been contradictory results concerning the effect of doping TiO₂ with Fe(III) upon its photocatalytic activity. We believe that this is due to the method used in adding the Fe(III) to TiO₂. This paper addresses this issue by using a precise adsorption process for loading stable aqueous suspensions (sols) of TiO₂ doped with Fe(III). In this manner, we control the speciation of Fe(III) on the surface of TiO₂ and subsequently use these loaded sols to produce stable thin-film photocatalysts. Adsorption isotherms for these systems at different pH (2.0 and 2.5) values showed that both pH and the concentration of Fe(III) in solution influence the adsorption density of Fe(III), the stability of the resulting sols, and the speciation (degree of polymerization) of Fe(III) ions on the surface of the TiO₂ nano-particles. UV-Vis spectroscopy on selected systems was the technique employed to confirm these results. The pore structure of the resulting gels (xerogels) prepared from these sols, as well as thermal stability of porous materials prepared by firing the xerogels have been determined by measuring N₂ adsorption as a function of firing temperature. Thermal analysis (TG–DTA) studies on xerogels obtained from some of these systems showed that the presence of Fe(III) species on the TiO₂ retards the conversion of anatase into rutile and therefore increases the thermal stability of the gel microstructure. Lastly, porous films, resulting from the casting of the sols on glass rings and subsequent firing, were used in photocatalytic studies. In the presence of UV light, these supported films were capable of degrading ethanol in the gas phase. While photocatalytic activity for Fe(III) loaded TiO₂ films is less than for TiO₂ films without Fe(III), the speciation of Fe(III) on the surface directly influences the behavior of the intermediate—acetaldehyde—formed in this reaction. Since we have only evaluated the effect of iron speciation on the degradation of ethanol, other target species may be influenced either advantageously or deleteriously depending upon the state of Fe(III) on the surface of TiO₂ photocatalysts.     

Feedback design in control reconfigurable systems

This paper is concerned with the design of reconfigurable control laws for fault-tolerant systems. From the control design point of view the issue of performance robustness during the system normal operation versus failure sensitivity at the time of a system component failure is addressed. To achieve a balanced design, a parametrized set of controllers satisfying a prescribed performance level is first constructed, and then the parameter is optimized under a detection criterion that sensitizes the measurements to some specific failures. An example involving aircraft surface impairment is given to explain the procedure for obtaining the optimized design.     

The Early Bird Gets the Worm,But the Second Mouse Gets the Cheese: Non‐Technological Innovation in Creative Industries

In the context of economic turmoil, firms in the creative industries (CIs) must make fast decisions as to when to break through with innovations. This paper discusses non‐technological, organizational innovation of early‐adopters, first movers and early followers in order to overcome persistent economic decline, and the implication of different strategies for innovation success. The strategic principle of the pioneer's advantage rests on pre‐emption – the premise that ‘the early bird gets the worm’ and this often applies to business model innovation (BMI). ‘But the second mouse gets the cheese’ points at early followers who may have a more systematic, strategic approach towards innovation. Greater understanding of the advantages of each strategic approach and their significance for innovation performance is critical for CIs where unpredictability and the accelerating pace of change pervade the decisions concerning innovation. Drawing on five exemplary cases of archaeological firms in Spain, this paper explores different innovation process dynamics. The study develops a contingency model where pioneers who challenge their current business model, may be outperformed by early followers who incorporate complementary management innovation (MI) initiatives into the BMI.     

Functional characterization of protein stabilized emulsions: Emulsifying behaviour of proteins in a valve homogenizer

Protein stabilised emulsions have been prepared in a valve homogeniser incorporated into a recirculating emulsification system, where the power input and number of passes have been varied. The food proteins studied were a soy-bean protein isolate, a whey protein concentrate (WPC) and a sodium caseinate. The emulsions obtained were characterized in terms of particle size distribution and amount of protein adsorbed on to the fat surface (protein load). Generally, the final fat surface area of the emulsions obtained increases more as a function of power input than as a function of number of passes. Distribution width, c_s, decreases mostly with increasing power supply and number of passes, but at the highest power input c_s increases. The protein load on the fat globules is largely determined by the fat surface area and by the type of protein adsorbed. The soy proteins give a high protein load and the caseinates give a low protein adsorption at small fat surface areas created. This relation is reversed at large surface areas of the fat globules. The relation between percentage protein adsorbed from bulk as a function of surface area suggests that the caseinates mainly cover the newly created interface by adsorption from the bulk, whereas the soy proteins fulfil this task mostly by spreading at the interface. Salt addition to 0.2M-NaCl enhances protein adsorption at the fat globule interface in the case of soy protein and caseinate, but for the whey proteins protein load is higher in distilled water.     

Feedback passivity of nonlinear discrete-time systems with direct input-output link

This paper is devoted to the study of the feedback passivity property in nonlinear discrete-time systems. The relative degree and zero dynamics of the non-passive system are related to the feedback passivity of the system. Two main results are presented. First, some relative degree-related properties of passive systems in general form are stated. Second, sufficient conditions in order to render a multiple-input multiple-output (MIMO) system passive by means of a static state feedback control law are obtained.     

European American and Chinese parents' responses to children's success and failure: Implications for children's responses.

The authors examined cultural differences in parents' responses to their children's performance. In Study 1 (N = 421), Chinese 5th graders reported that their parents de-emphasized their academic success and emphasized their academic failure, whereas their American counterparts reported that their parents did the opposite. This partially accounted for Chinese (vs. American) children responding less positively to success and more negatively to failure. In Study 2 (N = 128), Chinese and American mothers' responses to their 4th and 5th graders' performance were observed in the laboratory. The cultural differences in children's reports of parents' responses documented in Study 1 were replicated; mothers' responses were also associated with children's subsequent performance. In addition, Chinese mothers were more involved than were American mothers, but their affect was similar. Taken together, the results suggest that parents' responses to children's performance may be a channel for cultural transmission and perpetuation of responses to performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The intelligent help system COMFOHELP

The paper is concerned with the question of whether and under what conditions active help systems with plan recognition components that have been developed in the environment of artificial intelligence research are able to prove their value in the real context of commercial application programs. The question is investigated using the development of the COMFOHELP intelligent help system as an example. COMFOHELP supports the COMFOTEX graphical text processing program and has been developed by the Linguistic Information Science Group at the University of Regensburg since 1988. The system recognizes erroneous and suboptimal plans pursued by the user by analyzing the dialog history and comparing them with the correct plan for achieving the user's goal.Section 2 discusses the research situation and elaborates on those problems which up to now prevented research concepts for plan recognition and intelligent help systems from being practically applied. Testing error situations empirically is a first prerequisite since potential erroneous plans can only be established in real-world tests. The second prerequisite is a special system architecture which counteracts the problem of ambiguities in plan recognition. Section 3 introduces a first still restricted prototype version of COMFOHELP whose efficiency was verified in a statistical hypothesis test. The users performing their text processing tasks with the support of COMFOHELP came off significantly better than members of a reference group working without the intelligent help. Section 4 shows that the proposed COMFOHELP system architecture is reconfirmed by the results of extensive empirical investigations (with more than 100 users) of erroneous plans when using a more complex version of COMFOTEX. The architecture still proves to be worthwhile even when functionality is increased by a factor of three to four.     

Cheyletid fauna associated with stored products in Czechoslovakia

During the survey of the fauna of food processing factories in Czechoslovakia in the years 1962 through 1978, over 10,000 mites of the family Cheyletidae belonging to 10 species were found in 1560 samples. Cheyletus eruditus (Schrank) was a dominant species followed by C. malaccensis Oud. and C. trouessarti Oud. The species C. aversor Rohd., Cheletomorpha lepidopterorum (Shaw), C. hendersoni Baker, Cheyletia papillifera Volgin, Ker bakeri Zaher and Soliman and Grallacheles bakeri De Leon were obtained less frequently, the four last species being reported for the first time from Czechoslovakia. Acaropsellina sollers (Kuzin) may prove to be a junior synonym of Acaropsellina docta (Berlese).     

Determination of metals in fish livers by flameless atomic absorption spectroscopy

The samples are digested in nitric acid and evaporated to near dryness. Hydrogen peroxide is then added for complete oxidation of fat residues. Determination of metals is performed by flameless AAS with graphite furnace and results evaluated by the method of standard addition. The method is suitable for the determination of some non-volatile metals in fish livers in which the amount of available sample is limited; Pb, Cd, Cu and Zn have been determined in such samples.