A generalized Ufnarovski graph

An important tool for studying standard finitely presented algebras is the Ufnarovski graph. In this paper we extend the use of the Ufnarovski graph to automaton algebras, introducing the generalized Ufnarovski graph. As an application, we show how this construction can be used to test Noetherianity of automaton algebras.     

An experience sampling study of emotional reactions to music: Listener, music, and situation.

The Experience Sampling Method was used to explore emotions to music as they naturally occurred in everyday life, with a focus on the prevalence of different musical emotions and how such emotions are related to various factors in the listener, the music, and the situation. Thirty-two college students, 20 to 31 years old, carried a palmtop that emitted a sound signal seven times per day at random intervals for 2 weeks. When signaled, participants were required to complete a questionnaire on the palmtop. Results showed that music occurred in 37% of the episodes, and in 64% of the music episodes, the participants reported that the music affected how they felt. Comparisons showed that happiness-elation and nostalgia-longing were more frequent in episodes with musical emotions, whereas anger-irritation, boredom-indifference, and anxiety-fear were more frequent in episodes with nonmusical emotions. The prevalence of specific musical emotions correlated with personality measures and also varied depending on the situation (e.g., current activity, other people present), thus highlighting the need to use representative samples of situations to obtain valid estimates of prevalence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A lithographic approach to determine volume expansion factors during anodization: Using the example of initiation and growth of TiO2-nanotubes

The present work investigates the formation of nanotubes by anodizing titanium at 20 V in glycerol containing either 0.175 M or 0.35 M NH₄F. A photoresist-masking method of thin Ti films allows to use SEM cross-sections to directly obtain information on oxide morphology, layer thickness and metal substrate loss. Therefore not only features of the initial growth stages but also oxide expansion factors can accurately be determined. The expansion factors were found to be 2.4 for the initial formation of a barrier layer, 1.7–1.9 during pore initiation and 2.7–3.1 as the main nanotubes develop. These values (>2.6) suggest substantial contribution to steady state tube growth by a plastic oxide flow mechanism. Combined with RBS efficiency measurements the method presented here allows facile and direct investigation of the mechanism of pore/tube formation.     

Implementation of energy efficiency measures in compressed air systems: barriers,drivers and non-energy benefits

Increased global competition and resource scarcity drives industrial companies to cut costs. Energy can be a significant component of such cuts, particularly for energy-intensive companies. Improving energy efficiency in industry is complex, as it pertains to various energy-using processes that are heavily intertwined. One such process is the compressed air system (CAS), which is used in most industrial companies worldwide. Since energy efficiency improvement measures for various types of energy-using processes differ, technology-specific measures might encounter different barriers to and drivers for energy efficiency. The same applies to the non-energy benefits (NEBs) related to energy efficiency improvement measures; since measures vary between various energy-using processes, the perceived NEBs might be different as well. The aim of this paper is to study the barriers to, drivers for and NEBs of CAS energy efficiency improvement measures from the perspectives of three actors. Carried out as an interview study combined with a questionnaire, the paper merges the perspectives of users, audit experts and suppliers of CASs. The results showed that the major barriers are related to the investment, or are of an organisational character, and that organisational and economic factors seemed to be important for making positive decisions on energy efficiency investments and measures in CASs. Major NEBs for CASs include productivity gains and the avoidance of capital expenditures. The results of this study also address the importance of having a comprehensive approach to recognise additional effects of energy efficiency improvements in CASs.     

Offshore wind power policy and planning in Sweden

The main objective of this paper is to analyze the role of policy support schemes and planning systems for inducing offshore wind power development in Sweden. Specifically, it highlights the different types of economic, political and planning-related conditions that face offshore wind power investors in Sweden, and provides brief comparisons to the corresponding investment conditions in Denmark, Norway and the UK. The analysis shows that in Sweden existing policy incentives are generally too weak to promote a significant development of offshore wind power, and the paper provides a discussion about a number of political and economic aspects on the choice between different support schemes for offshore wind in the country. Swedish permitting and planning procedures, though, appear favorable to such a development, not the least in comparison to the corresponding processes in the other major offshore wind countries in Europe (e.g., the UK). On a general level the paper illustrates that the success and failure stories of national offshore wind policies and institutions cannot be easily transferred across country borders, and the analysis shows that both the political and the legal frameworks governing the investment situation for offshore wind farms in Denmark, Norway, Sweden and the UK differ significantly.     

An interdisciplinary perspective on industrial energy efficiency

This paper combines engineering and social science approaches to enhance our understanding of industrial energy efficiency and broaden our perspective on policy making in Europe. Sustainable development demands new strategies, solutions, and policy-making approaches. Numerous studies of energy efficiency potential state that cost-effective energy efficiency technologies in industry are not always implemented for various reasons, such as lack of information, procedural impediments, and routines not favoring energy efficiency. Another reason for the efficiency gap is the existence of particular values, unsupportive of energy efficiency, in the dominant networks of a branch of trade. Analysis indicates that different sectors of rather closed communities have established their own tacit knowledge, perceived truths, and routines concerning energy efficiency measures. Actors in different industrial sectors highlight different barriers to energy efficiency and why cost-effective energy efficiency measures are not being implemented. The identified barriers can be problematized in relation to the social context to understand their existence and how to resolve them.     

di/dt Noise in CMOS Integrated Circuits

This is an overview paper presenting di/dtnoise from a designers perspective. Analysis and circuit designtechniques are presented taking package parasitics into account.The main focus is on digital CMOS design, but analysis and designsuggestions can easily be extended to mixed-mode design.     

Backstepping approach for design of PID controller with guaranteed performance for micro-air UAV

Flight controllers for micro-air UAVs are generally designed using proportional-integral-derivative (PID) methods, where the tuning of gains is difficult and time-consuming, and performance is not guaranteed. In this paper, we develop a rigorous method based on the sliding mode analysis and nonlinear backstepping to design a PID controller with guaranteed performance. This technique provides the structure and gains for the PID controller, such that a robust and fast response of the UAV (unmanned aerial vehicle) for trajectory tracking is achieved. First, the second-order sliding variable errors are used in a rigorous nonlinear backstepping design to obtain guaranteed performance for the nonlinear UAV dynamics. Then, using a small angle approximation and rigorous geometric manipulations, this nonlinear design is converted into a PID controller whose structure is naturally determined through the backstepping procedure. PID gains that guarantee robust UAV performance are finally computed from the sliding mode gains and from stabilizing gains for tracking error dynamics. We prove that the desired Euler angles of the inner attitude controller loop are related to the dynamics of the outer backstepping tracker loop by inverse kinematics, which provides a seamless connection with existing built-in UAV attitude controllers. We implement the proposed method on actual UAV, and experimental flight tests prove the validity of these algorithms. It is seen that our PID design procedure yields tighter UAV performance than an existing popular PID control technique.     

A 3D Cu-Naphthalene-Phosphonate Metal–Organic Framework with Ultra-High Electrical Conductivity

A conductive phosphonate metal–organic framework (MOF), [{Cu(H₂O)}(2,6-NDPA)_0.5] (NDPA = naphthalenediphosphonic acid), which contains a 2D inorganic building unit (IBU) comprised of a continuous edge-sharing sheet of copper phosphonate polyhedra is reported. The 2D IBUs are connected to each other via polyaromatic 2,6-NDPA's, forming a 3D pillared-layered MOF structure. This MOF, known as TUB40, has a narrow band gap of 1.42 eV, a record high average electrical conductance of 2 × 10² S m⁻¹ at room temperature based on single-crystal conductivity measurements, and an electrical conductance of 142 S m⁻¹ based on a pellet measurement. Density functional theory (DFT) calculations reveal that the conductivity is due to an excitation from the highest occupied molecular orbital on the naphthalene-building unit to the lowest unoccupied molecular orbital on the copper atoms. Temperature-dependent magnetization measurements show that the copper atoms are antiferromagnetically coupled at very low temperatures, which is also confirmed by the DFT calculations. Due to its high conductance and thermal/chemical stability, TUB40 may prove useful as an electrode material in supercapacitors.