Special Manner Research Articles

Special fluorescence enhancement and aggregation in Langmuir–Blodgett films of 4,4′-dicyano-(3,4-dibutyl-2-thienylethynyl)biphenyl

In this paper, we report the synthesis of a new rigid compound, 4,4′-dicyano-(3,4-dibutyl-2-thienylethynyl)biphenyl (1), as well as the preparation and spectroscopic characterizations of its Langmuir–Blodgett (LB) films. Absorption and emission spectra have shown molecular aggregation of 1 in LB films. An unexpected irradiation-induced luminescence enhancement (IILE) was observed when these LB films were exposed under ultraviolet (UV) irradiation. Because no difference could be observed in UV–visible (UV–vis), fluorescence bands, infrared and X-ray diffraction spectra of these LB films before and after UV irradiations, changes of the molecular structure could be ruled out. But aggregates obtained with other methods, such as from water–tetrahydrofuran binary solution and solution casting films or dispersed microcrystals, did not show this IILE effect. This suggested that the IILE effect should be resulted from the special aggregation manner of 1 in the LB films.

Numerical analysis of the Toda lattice equations

Numerical solutions to three systems of integrable evolutionary equations from the Toda lattice hierarchy are analyzed. These are the classical Toda lattice, the second local dispersive flow, and the second extended dispersive flow. Special attention is given to the properties of soliton solutions. For the equations of the second local flow, two types of solitons interacting in a special manner are found. Solutions corresponding to various initial data are qualitatively outlined.

The structural characterization and its influence on photoluminescence of lithium tetra-(8-hydroxy-quinolinato) Boron

Lithium tetra-(8-hydroxy-quinolinato) boron (LiBq4) is one kind of blue light-emitting material with good performances. In this paper, LiBq4 sample was synthesized and purified. The purity is up to 97.6%. In order to investigate the influence of LiBq4 structure on its optical characteristics, especially on the shift of photoluminescence (PL) central wavelength, compared with that of tris-(8-hydroquinoline) aluminum (Alq3), a joint experiment based on a combination of X-ray diffraction (XRD) spectrum, infrared absorption (IRA) spectrum, hydrogen nuclear magnetic resonance (HNMR) spectrum, absorption and photoluminescence spectra of LiBq4 was performed. IRA and HNMR spectra generally make certain the molecular structure, and illuminate the interaction among the atoms in LiBq4. Absorption and photoluminescence spectra qualitatively suggest the basic optical characteristic of LiBq4 and that the emitted light results from 8-hydroxyquinoline rings. By comparing LiBq4 with Alq3, the conclusion that besides B−N covalent bond, B−O is another important factor which heavily influence on the PL peak can be drawn. Furthermore, the influence of LiBq4‘s special coupling manner on PL peak is demonstrated too.

REMARKS ON H*infin; CONTROLLER DESIGN FOR SISO PLANTS WITH TIME DELAYS 1

The skew Toeplitz approach is one of the well developed methods to design H*infin; controllers for infinite dimensional systems. In order to be able to use this method the plant needs to be factorized in some special manner. This paper investigates the largest class of SISO time delay systems for which the special factorizations required by the skew Toeplitz approach can be done. Reliable implementation of the optimal controller is also discussed. It is shown that the finite impulse response (FIR) block structure appears in these controllers not only for plants with I/O delays, but also for general time-delay plants.

Design of an anisotropic quarter-wave polariser without insertion loss caused by mismatch

The authors present novel high-performance polariser designs. The polarisers provide perfect linear-to-circular polarisation transformation without insertion loss at the centre frequency. Four designs are discussed for use in two situations. In the first situation, a polariser is inserted into an isotropic medium and, in the second, a polariser is sandwiched between two isotropic media with different intrinsic impedances. For the first situation, two designs are proposed based on the dielectric window and impedance matching. For the second, two further designs are proposed. In the first, two anisotropic media are cascaded in a special manner to perform the polarisation transformation without insertion loss. For a simpler uniaxial medium, the design utilises an impedance transformer and the polariser mentioned in the first situation. One of the resulting polarisers has an infinite transmission bandwidth, if the medium is nondispersive. Hence, the bandwidth of the polariser is solely determined by the axial ratio bandwidth. Based on the two-transmission-lines model, the polariser can be examined easily using commercial radio-frequency software. Some examples and simulated results are presented to validate these designs.

Kanchipuram Sari: Design for Auspiciousness

October 01 2005 Kanchipuram Sari: Design for Auspiciousness Aarti Kawlra Aarti Kawlra Search for other works by this author on: This Site Google Scholar Author and Article Information Aarti Kawlra Online ISSN: 1531-4790 Print ISSN: 0747-9360 © 2005 Massachusetts Institute of Technology2005 Design Issues (2005) 21 (4): 54–67. https://doi.org/10.1162/074793605774597451 Cite Icon Cite Permissions Share Icon Share Facebook Twitter LinkedIn MailTo Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Search Site Citation Aarti Kawlra; Kanchipuram Sari: Design for Auspiciousness. Design Issues 2005; 21 (4): 54–67. doi: https://doi.org/10.1162/074793605774597451 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsDesign Issues Search Advanced Search This content is only available as a PDF. © 2005 Massachusetts Institute of Technology2005 Article PDF first page preview Close Modal You do not currently have access to this content.

Assessing the Environmental-Hazard Potential for Life Cycle Assessment, Eco-Efficiency and SEEbalance (8 pp)

BASF has developed the eco-efficiency analysis tool to address not only strategic issues but also issues posed by the marketplace, politics and research. The goal was to develop a tool for supporting decision-making processes, which is useful for many of applications in the Chemical and other industries. A part of the eco-efficiency analysis involves the evaluation of the toxicity and the eco-toxicity potential. Many life cycle analyses do not include an assessment of the toxicity potential nor the eco-toxicity potential. However, in order to arrive at a comprehensive assessment of products and processes, it is often the eco-toxicity potential, which constitutes an important factor with regard to the evaluation of sustainability. The cradle-to-grave approach is also important for this calculation and will be done based on a database that will be discussed also in this paper. The method used for the determination of the eco-toxicity potential follows the basic rules of the European Union Risk Ranking System (EURAM). The other criteria of the ecological fingerprint are combined with the economical results in the eco-efficiency portfolio. The results of the studies are shown in a simple diagram, the eco-efficiency portfolio. Therefore ecological data are summarized in a special manner as described previously. It has been shown that the weighting factors, which are used in our method, have a negligible impact on the results. In most cases, the input data have the dominant impact on the results of the study. The eco-toxicity assessment will be a part of the ecological calculation. Because of the cradle-to-grave approach, substances of the whole life cycle can be identified that might have a toxic impact to the environment. The results can be used for optimization of the process. The new calculation model allows the assessment of eco-toxicological substances in an appropriate and easy way. In most of the cases the data from a European safety data sheet are sufficient for the calculation. The normalized data can be incorporated very easily in the ecological fingerprint and in the drawing of the eco-efficiency portfolio. LCA in combination with the evaluation of the eco-toxicity potential will for reasons of optimizing for least impact become more important in certain cases. Especially in those systems where water emissions are likely, the use of the evaluation system in the eco-efficiency analysis is recommended. This new methodology allows the calculation of eco-toxicity potentials in a short time with a small set of input information. The analytical eco-efficiency tool helps in implementing more sustainable processes and products in the future.

Criteria for the Optimization of Parameters of a Multibunch Scheme of Wakefield Acceleration

We propose criteria for the optimization of a wakefield acceleration scheme in a dielectric-lined waveguide structure, which is aimed at increasing the efficiency of energy transfer from the driving to witness (driven) electron bunches with simultaneous increase in the accelerating field gradient. It is suggested to use a multimode acceleration structure excited by a train of short electron bunches profiled in a special manner. The proposed scheme provides for a maximum energy transformer ratio simultaneously with an increase in the wakefield as compared to the values typical of the traditional linear acceleration scheme.

Nonlinear adjustment in the forward premium: evidence from a threshold unit root test

This paper considers testing the mean reversion of the forward premium in a nonlinear framework. In contrast to previous studies, we consider a novel approach that allows for testing for a unit root in the forward premium while explicitly allowing for nonlinearity in the data. Within this approach, we employ bootstrap methods based on threshold autoregressive (TAR) models to investigate whether the 1- and 3-month forward premia for six industrialized countries are mean-reverting. Overall, we are able to reject the null hypotheses of linearity and nonstationarity indicating nonlinear mean reversion. Furthermore, large deviations of the forward premium from its equilibrium band are found to have faster speed of mean reversion than small deviations, which are strongly persistent. In all, the results support the view that the forward premium exhibits mean reversion, but in a special manner not captured by the usual linear tests. Finally, the results have important implications for foreign exchange market efficiency under risk aversion.

Consultation with the Specialist

Consultation with the Specialist

How 'postmodern' is 'postmodernism'?

This article sets out to question the claim that “postmodernism” is merely a development of the second half of the 20th century. What is unique about contemporary postmodernism is the way in which it has combined intellectual developments that emerged during the past five hundred years in a special manner. Therefore the supposed relatively recent origin of postmodernity it is not only misleading but also historically unsound. This is shown by going back to the pre- Enlightenment roots of both “modernity” and “postmodernity” – and it is done by accounting for the emergence and historical sources of modern irrationalism, historicism and the so-called “linguistic turn”.

A Gust Model for Wind Turbine Design

A new method, so called constrained stochastic simulation, has been developed in order to generate extreme gust time series, to be used to calculate the extreme loading of wind turbines. A constrained simulation corresponds to the addition, in a special manner, of turbulence and a deterministic part (which resembles the auto correlation function of turbulence). The stochastic gusts produced in this way has been denoted NewGust and it is proved that they are, in a statistical sense, not distinguishable from gusts selected from a (very long) stochastic time series, with the same amplitude. The NewGust method forms a part of on overall probabilistic method to determine the distribution of the wind turbine response on gusts. This new probabilistic method enables wind turbine manufacturers to build more reliable and optimised wind turbines. The theoretical mean gust shape, as well as the probability of occurrence of gusts, has been verified by measurements. In addition preliminary comparisons between numerical load simulations and wind turbine load measurements have been carried out.

Reprogramming of epigenetic inheritance by somatic cell nuclear transfer

Somatic cloning by nuclear transfer returns a differentiated cell to a totipotent stage, a process termed nuclear reprogramming. During this de-differentiation process, genes inactivated during tissue differentiation are re-activated in a temporal and spatial special manner. It is believed that tissue differentiation occurs through epigenetic mechanisms, genetic inheritance that does not involve changes in DNA sequences. Developmental abnormalities and a high mortality rate in cloned offspring have frequently been observed and probably result from incomplete nuclear reprogramming. In this review, the reprogramming of two epigenetic mechanisms, imprinting and X chromosome inactivation, as well as recent attempts to modify pre-existing epigenetic marks in donor cells to improve nuclear transfer efficacy, are discussed.

Convergence Acceleration of Some Continued Fractions

The tails of a continued fraction satisfy a bilinear recurrent equation. Transforming iteratively these tails (in a special manner) as well as these equations one may obtain finally, for a given fraction, a new, so-called diagonal continued fraction (DF) having the same value. For many important classes of continued fractions the DF has a calculable analytical form and converges qualitatively faster. Using the same method one may transform some hypergeometrical series directly into fast convergent DFs.

Stochastic gust model for design calculations of wind turbines

A new probabilistic method has been developed in order to determine the long-term distribution of the extreme response of wind turbines. The probabilistic method relies on the quick determination of the response to a single gust, with a given amplitude, by means of the so-called constrained simulation. A constrained simulation corresponds to the addition, in a special manner, of turbulence and a deterministic part (which resembles the autocorrelation function of turbulence). The stochastic gusts produced in this way has been denoted NewGust and are, in a statistical sense, not distinguishable from gusts selected from a (very long) stochastic time series, with the same amplitude.

'An entirely special manner': Mozart's piano concerto No. 14 in E flat, K.449, and the stylistic implications of confrontation

A HIGH POINT in Mozart's career as a composer-performer in Vienna came during the spring of 1784. In a letter to his father Leopold, dated 4 March 1784, Mozart listed an astonishing 22 engagements for the period 26 February to 3 April, including three concerts in a subscription series at the Trattnerhof, two at the Burgtheater (one of which was subsequently cancelled) and several at the salons of Prince Galitsin and Count Esterhazy.' According to Mozart, the Trattnerhof and Burgtheater performances were particularly well received: he 'won extraordinary applause', had a hall that was 'full to overflowing' and was praised repeatedly for the first subscription concert on 17 March. He described the Burgtheater concert-for which he performed the Piano Concertos Nos. 15 and 16 in B flat and D, K.450 and 451, and the Quintet for piano and winds, K.452-as 'most successful' and remarked that it was 'greatly to my credit that my listeners never got tired'.2 Even if Mozart can hardly be relied upon as an impartial witness to his own success, his list of subscribers to the Trattnerhof series, containing 176 names ('thirty more than Richter and Fischer together'), many from the highest artistic, intellectual, cultural and aristocratic echelons of society,3 testifies to the high regard in which he was held. The Wunderkind who had charmed the Viennese in his youth had become a fully endorsed member of the Viennese musical establishment. The foundation for Mozart's considerable successes in early 1784 was laid by the three piano concertos composed for the aforementioned Trattnerhof and Burgtheater concerts, K.449 in E flat, K.450 in B flat, and K.451 in D (Nos. 14-16), as well as by K.453 in G (No. 17), performed by Mozart at a subsequent concert at the Burgtheater on 29 April.4 Sending these works to his father on 15 May 1784, Mozart distinguished K.449 from the later three concertos on the grounds that it was scored for a smaller accompanying orchestra:

Preserving Your Revenue-management System as a Trade Secret

Abstract A hotel's or airline's revenue-management system is ( 1 ) quite valuable and ( 2 ) a trade secret. Trade secrets involve special proprietary information and processes, including publicly available information that is assembled in a special manner by the trade secret's owner. Establishing that a process is a trade secret involves demonstrating that it is, in fact, a secret, that information about the process is restricted to employees and licensess, and that the owner makes a specific effort to shield the information. Hotels' revenue-management systems are particularly at risk for either general disclosure or corporate espionage because of the relatively rapid turnover of employees and the fact that those employees often go to work for competitors. Thus, a wise hotelier will take the following steps to protect the company's revenue-management system: ( 1 ) maintain the information's physical security by restricting access, ( 2 ) place restrictive legends on the information stating that it is in fact confidential, ( 3 ) state in employee handbooks that the revenue-management information is a trade secret and will be shared only in confidence, ( 4 ) require revenue-management employees to sign confidentiality agreements, ( 5 ) train employees and remind them regularly of the confidentiality of the revenue-management information, and ( 6 ) ask exiting employees to reaffirm their agreement not to share the confidential trade secrets. The former employer may also consider sending an advisory letter to a departing employee's new employer stating that the revenue-management information is confidential, but that letter-writing step involves other issues that require legal counsel.

Tensile bond strengths of four different dentin adhesives on irradiated and non‐irradiated human dentin in vitro

This study evaluated the influence of irradiation on dentin bond strength. Sixty irradiated and 60 non‐irradiated human third molars were used. The irradiation dose of 60 Gy was fractionally applied over 6 weeks (2 Gy day−1, 5 days week−1). All teeth were prepared in a special manner allowing the simulation of intra‐pulpal pressure and dentin perfusion. Dentin specimens with a thickness of 2·0 mm were obtained under standardized conditions. The specimens were randomly assigned to four experimental groups. Tensile bond strength of four different dentin bonding agents (Scotchbond™ 1, Solobond Plus®, Prime&Bond™ 2·1 and Syntac®) was evaluated using an Instron Universal testing machine. Pairwise comparison did not show any significant differences between the irradiated and non‐irradiated groups. The influence of the different dentin adhesives was significant (P=0·0001; ANOVA). Compared with Solobond Plus® and Prime&Bond™ 2·1, the use of Scotchbond™ 1 resulted in a significantly higher tensile bond strength in non‐irradiated specimen (P< 0·05; closed test procedure based on Kruskal–Wallis test). Within the limitations of an in vitro study, it can be concluded that adhesive restoration procedures can be successfully used in patients irradiated for cancer of the head and neck.

Detection of small comets with a ground‐based telescope

The Iowa Robotic Observatory (IRO) located in the Sonoran desert near Sonoita, Arizona, was used for an optical search for small comets in the vicinity of Earth during the period October 1998 through May 1999. The previous reports of detection of the small comets with an optical telescope were based on the search with the Space watch Telescope during November 1987, January 1988, and April 1988. The searches with both of these telescopes required that their fields of view be moved in a special manner across the celestial sphere in order to maximize the dwell times of the comet images on a small set of pixels of the telescopes' array detectors. There were sightings of nine small comets in the set of 1500 usable images which were gained with the IRO. The possibility that these events were spurious owing to random fluctuations of the responses in the sensors was eliminated in two different ways. The first method was the use of a shutter to provide either two or three trails for the same small comet. In the two‐trail mode, no events were seen with three trails, and for the three‐trail mode, no events were seen with two trails. The second assurance that the trails were not due to noise was provided by a rigorous determination of the signals S and signal‐to‐noise ratios (S/N) in the trails due to random statistical fluctuations, or “random trails,” and the subsequent comparison with these parameters for the small‐comet sightings. The diameter of the primary mirror of the IRO is significantly smaller than that of the Spacewatch Telescope, and thus the uncertainties in the number densities of the small comets are greater with the IRO. However, within a factor of 2 or 3, the average number densities of small comets detected with the IRO are similar to those observed previously with the Spacewatch Telescope, that is, about 10−18/m3.

Liporecycling: A Technique for Facial Rejuvenation and Body Contouring

Background. Soft tissue augmentation using autologous fat is a standard method in facial rejuvenation and in refinement of body contouring. Different procedures by different authors have been described, each with its specific advantages and disadvantages. Objective. The purpose of this article is to describe a method of harvesting, processing, and reinjection of fat that provides new aspects and advantages compared to previously described procedures. Methods. We report about a new method of autologous fat grafting. Fat is harvested during machine-assisted liposuction in tumescent local anesthesia with microcannulas, processed in a special open manner, and reinjected through a 24-gauge needle for intra- and subdermal augmentation. Results. Short- and long-term results are equivalent to other methods of fat cell grafting. Conclusion. Advantages of the described method include easy harvesting during conventional machine-assisted liposuction, the possibility of removing undesired bands of fibrous tissue from the graft, and easy passage through a 24-gauge needle. Thus sub- and intradermal augmentation is possible with the same material and syringe.