Application to cleaning of waste plastic surfaces using atmospheric non-thermal plasma jets

The removal of paint on the surface of waste plastics is difficult by the conventional process; in this research, a new cleaning mechanism using atmospheric plasmas was examined through optical emission spectroscopy, electron spectroscopy for chemical analysis, and scanning electron microscopy. Results indicate that an increase of pulse frequency enables for a short processing time for the removal of the paint film, signifying that the production of radicals in plasma, especially oxygen radicals, can be controlled by pulse frequency.Plasma jets were generated under the experimental conditions of an input power of 250 W to 400 W, a pulse frequency of 2 kHz to 12 kHz, and a plasma gas flow rate of 30 L/min. Examination of the intensity ratio of the reactive species, as measured by emission spectroscopy, showed that the O/N value increased with an increase in pulse frequency. Results of analysis with electron spectroscopy for chemical analysis show that nitrogen atoms and molybdenum in only the paint film decreased through plasma processing.     

Block checker/diagonal transformation matrices,their properties,and the interplay with fast-lifting

This article introduces what we call block checker matrices with some specific structures characterised by a set of integers, and then introduces the permutation matrices called block checker/diagonal (BCD) transformation matrices that relate block checker matrices with block diagonal matrices through similarity transformations. The study is motivated by the importance of the fast-lifting technique in control theory, especially in the study of sampled-data systems and time-delay systems. More precisely, it is partly motivated by the desire for alleviating the bother of describing the class of the matrices commuting with block diagonal matrices, and for such a purpose the permutation with BCD transformation matrices is helpful. The study further extends to investigating the various useful properties among BCD transformation matrices, as well as their interplay relations with various variants of fast-lifting, e.g. full-vector fast-lifting and subvector-wise fast-lifting, or one-stage fast-lifting and two-stage fast-lifting. The usefulness of the results in the context of the fast-lifting treatment is also suggested.     

Trace formula of linear continuous-time periodic systems via the harmonic Lyapunov equation

In the former part of this paper, a trace formula is established for the H 2 norms of a class of finite-dimensional linear continuous-time periodic (FDLCP) systems based on the solution of the harmonic Lyapunov equations. This trace formula is quite similar in form to what we have for the H 2 norm of an LTI continuous-time system apart from the fact that infinite-dimensional matrices are involved in the FDLCP setting. Based on this formula, in the latter part of this paper some trace formulas are developed via the approximate modelling and truncating approach, which are numerically implementable in most practical FDLCP systems. There are numerical examples to illustrate the efficacy of the trace formulas suggested.     

Formation of high-purity organic thin films by gas flow deposition and the effect of impurities on device characteristics

A gas flow deposition (GFD) system was developed to manufacture large-scale organic light-emitting diodes (OLEDs). A N,N′-di(1-naphthyl)-N,N′-diphenylbenzidine (α-NPD) thin film with a high purity of 99.97% was obtained using the GFD system. The film properties such as morphology, and electrical and optical characteristics were almost the same as those of films made by conventional vacuum thermal evaporation.     

Context-dependent product line engineering with lightweight formal approaches

This paper proposes a new style of product line engineering methods. It focuses on constructing embedded systems that take into account the contexts such as the external physical environments. In current product line development projects, Feature Analysis is mainly conducted from the viewpoint of system configurations: how hardware and software components are configured to constitute a system. In most cases, contexts are not considered explicitly. As a result, unexpected and unfavorable behavior might emerge in a system if a developer does not recognize any possible conflicting combinations between the system and contexts. To deal with this problem, this paper provides the notion of a context-dependent product line, which is composed of the system and context lines. The former is obtained by analyzing a family of systems. The latter is obtained by analyzing features of contexts associated to the systems. The system and context lines contain reusable core assets. The configuration of selected system components and contexts can be formally checked at the specification level. In this paper, we show a development process that includes the creation of both product line assets as well as context assets.     

Robust model-following controller design for LTI systems affected by parametric uncertainties: a design example for aircraft motion

This article addresses the design problem of a robust model-following controller (MFC) which minimises the error between plant controlled output and model output for a linear time-invariant (LTI) plant system affected by parametric uncertainties and an LTI target model. To design such an MFC, a previously proposed MFC scheme, whose applicability has already been demonstrated with flight controller design, is adopted in this article. Our design procedure is as follows: first, a basic MFC is designed using the nominal LTI plant model and the LTI target model while a structured free matrix in the MFC is not assigned; second, model-following performance of the MFC for appropriately defined disturbance input and model input for the parametric uncertain plant model and the LTI target model is minimised using the structured free matrix; and finally, a robust MFC is obtained using the basic MFC and the optimal structured matrix. In the second step, an iterative design method for robust H ₂ controllers for LTI parameter-dependent (LTIPD) systems using parameter-dependent Lyapunov functions (PDLFs), which is also proposed in this article, is applied. Two MFCs for the lateral-directional (L/D) motions of a research aircraft, which has been developed for an in-flight simulator, for two different real aircraft models, i.e. a Boeing 747 model and a Lockheed Jetstar model, are designed and their performance is confirmed via numerical simulations and flight tests.     

An ESR study of the film formation steps of vapor deposition polymerization of polyamic acid

A film of polyamic acid is formed by vapor deposition polymerization of pyromellitic dianhydride (PMDA) and 4,4′-diaminodiphenyl ether (ODA). We have taken ESR spectrum during the polymerization process and compared it with the ESR spectrum of films obtained from solution polymerization. In the intermediate polymers during vapor deposition polymerization, the amide bond (? CONH? ) is coplanar with the benzene ring and two protons in the PMDA molecule. This intermediate polymer has one unpaired electron that interacts with the two nitrogen nuclei equally. On the other hand, in the polymer obtained by solution polymerization, the amide bond and the benzene ring of PMDA are not coplanar. In this polymer, too, some of the molecules have an unpaired electron that seems to have almost no coupling with NH groups. These results imply that the polymer formation via vapor deposition proceeds through different intermediates and different molecular configurations from that via the solution process.     

Analysis of nonlinear transient responses of piezoelectric resonators

The electric transient response method is an effective technique to evaluate material constants of piezoelectric ceramics under high-power driving. In this study, we tried to incorporate nonlinear piezoelectric behaviors in the analysis of transient responses. As a base for handling the nonlinear piezoelectric responses, we proposed an assumption that the electric displacement is proportional to the strain without phase lag, which could be described by a real and constant piezoelectric e-coefficient. Piezoelectric constitutive equations including nonlinear responses were proposed to calculate transient responses of a piezoelectric resonator. The envelopes and waveforms of current and vibration velocity in transient responses observed in some piezoelectric ceramics could be fitted with the calculation including nonlinear responses. The procedure for calculation of mechanical quality factor Q(m) for piezoelectric resonators with nonlinear behaviors was also proposed.     

A performance evaluation of disassembly systems with reverse blocking

For sustainable manufacturing, manufacturers should construct and design inverse manufacturing systems consisting of assembly and disassembly systems. The sorting process in the disassembly system is the first process of the whole inverse manufacturing system. Therefore, it can become a bottleneck and decrease the productivity of the whole inverse manufacturing systems.This study focuses on a disassembly system with reverse blocking in a sorting process [Yamada, T., & Matsui, M. (2003). Disassembly production systems and its design issues. Reprints of Japan Industrial Management Association, Spring meeting, Chofu, Japan, May, 144–145 (in Japanese)]. It generalizes the queuing model and discusses the performance of the disassembly system by mathematical and numerical analysis. First, the sorting process with reverse blocking is generally modeled as a queuing system. Next, the stationary state equations of the system are formulated, and the objective function is set as the throughput. Finally, the system performance is discussed by mathematical and numerical analysis in cases of a different number of stations and buffers, and also an example of the system design is shown and discussed in view of the busy rate, blocking probability and throughput.