Measurements of neutral atom diffusion and electron-ion recombination by laser enhanced ionisation and planar laser induced fluorescence in an air-acetylene flame

The spatial and temporal evolution of a depleted atomic distribution created by laser enhanced ionisation (LEI) was employed to determine both a diffusion coefficient for sodium (Na) and an electron (e(-)) and sodium ion recombination rate coefficient in an analytical air-C2H2 flame. A depleted distribution of neutral sodium atoms was produced in a flame by ionising approximately 80% of the irradiated sodium atoms in a well defined region using a two step LEI excitation scheme. Following depletion by ionisation, planar laser induced fluorescence (PLIF) images of the depleted region recorded the diffusion and decay of the depleted Na distribution for different depletion-probe delays. From measurements of the diffused width of the distribution, an accurate diffusion coefficient D = (1.19 +/- 0.03) x 10(-3) m(2) s(-1) for Na was determined in teh burnt gases of the flame. Measurements of the integrated fluorescence intensity in the depleted region for different depletion-probe delays were related to an increase in atomic sodium concentration caused by electron-ion recombination. At high concentrations (greater than or equal to 50 mu g ml(-1)), where the electron and ion concentrations in the depleted region were assumed equal, a recombination rate coefficient of 4.2 x 10(-9) cm(3) s(-1) was calculated. (C) 1997 Elsevier Science B.V.

Young people's beliefs about intergenerational communication - An initial cross-cultural comparison

This article examines young people's perceptions of their conversations with older people (age 65-85) across nine cultures-five Eastern and four Western. Responses from more than 1,000 participants were entered into a cross-national factor analysis, which revealed four initial factors that underlie perceptions of intergenerational conversations. Elder nonaccommodation was when young participants reported that older people negatively stereotyped the young and did not attend to their communication needs. On the other hand, elder accommodation was when older people were perceived as supportive, attentive and generally encouraging to young people. A third factor was respect/obligation and a fourth factor labeled age-irrelevant positivity described a situation where young people felt conversations with much older people were emotionally positive and satisfying, age did not matter: Examining cross-cultural differences, some East versus West differences were observed, as might be expected, on the basis of simplistic accounts of Eastern collectivism versus Western individualism. However the results challenge commonsense notions of the status of old age in Eastern versus Western cultures. On some dimensions, participants from Korea, Japan, People's Republic of China, Hong Kong, and the Philippines appear to have relatively less positive perceptions of their conversations with older people than the Western cultures-the United States, Australia, New Zealand and Canada. But there was also evidence of considerable cultural variability, particularly among Eastern cultures-variability that has heretofore all too often been glossed over when global comparisons of East versus West are made. A range of explanations for these cultural differences is explored and implications for older people in these societies are also considered.

Antiphase dynamics of a chaotic multimode laser

Antiphase dynamics of an optically pumped NH3 bidirectional ring laser under the chaotic, phase-sensitive mode coupling is experimentally observed. Our experimental result suggests strongly that the dynamics is a generic behavior of the laser.

Sintering kinetics of Mo-free cermets

Titanium carbonitride-based cermets are important materials for contemporary cutting tools. Ceramic powders of Ti(CN), TaC, WC were mixed, compacted and heat-treated at high temperatures to form (Ti, W, Ta)(C, N) solid solution, which was then ball-milled to fine powders before being mixed with metallic binder and compacted. Liquid-phase sintering of the samples was carried out in a nitrogen atmosphere at different sintering temperatures and holding times. The microhardness and porosity of the sintered cermets were studied. It is demonstrated that the microhardness increases with sintering temperature, but at the same time, the porosity level also goes up with temperature and time. At the beginning of sintering (zero holding time), the majority of the pores are small (0.1 similar to 1 mu m); during sintering, the larger ports grow at the expense of smaller pores and the resulting pores are all concentrated in the 10 similar to 100 mu m range. The number of larger pores increases with temperature and prolonged holding time, which results in deteriorated properties. (C) 1997 Elsevier Science S.A.

A compact shock-assisted free-piston driver for impulse facilities

A free-piston driver that employs entropy-raising shock processes with diaphragm rupture has been constructed, which promises significant theoretical advantages over isentropic compression. Results from a range of conditions with helium and argon driver gases are reported. Significant performance gains were achieved in some test cases. Heat losses are shown to have a strong effect on driver processes. Measurements compare well with predictions from a quasi-one-dimensional numerical code.

Enabling International Communication among Brazilian Occupational Therapists: Seeking Consensus on Occupational Terminology

The purpose of this study was to examine how key occupational therapy terminologies are used by Brazilian occupational therapists. A nominal group approach combined with a Delphi technique involving 31 Brazilian occupational therapists was applied. A sociolinguistic approach was adopted since it broadens our understanding of the social and cultural determinants of terminology consolidation. Brazilian occupational therapists were found to adopt the term activity more often than human action or doing. Even less often were praxis and occupation applied. No consensus was reached regarding which of the terms is most preferred. While Brazilian occupational therapists have been developing their profession from international standards, it is still embedded in local demands and policies. Additionally, the political context must be considered when building an international dialogue between members of a professional body. Such a dialogue could engage professionals from different countries in meaningful exchanges about their practices. These exchanges may lead to the development of solid professional communities that can contribute meaningfully to social change. Copyright (C) 2010 John Wiley & Sons, Ltd.

Validation of ASHA FACS-Functional Assessment of Communication Skills for Alzheimer Disease Population

This study vas aimed to validate the American Speech-Language-Hearing Association Functional Assessment Of Communication Skills (ASHA FACS) for a Brazilian population. The scale was translated and adapted into Portuguese. Thirty-two patients with mild Alzheimer disease (AD). 25 patients with moderate AD. and 51 elderly without dementia were examined with Mini Mental State Examination, Geriatric Depression Scale. and Alzheimer Disease Assessment Scale-Cognitive subscale (ADAS-cog). The ASHA FACS was answered by their relative/caregiver. The scale`s internal consistency. its inter-examiner and intra-examiner`s reproducibility. and scale`s criterion validity were researched by correlation with ADAS-cog,. The sensitivity and specificity Were also researched. Statistical analyses indicated that the ASHA FACS has excellent internal consistency (Cronbach alpha = 0.955), test-retest reliability (interclass correlation coefficient = 0.995; P < 0.001). and inter-examiners (interclass correlation coefficient = 0.998: P < 0.001). It showed excellent criterion validity when correlated with ADAS-cog,. The ASHA FACS scale showed good sensitivity (75.0%) and specificity (82.4%) values once it is an ecologic and broad evaluation. The ASHA FACS Portuguese version is a valid and reliable instrument to verify communication alterations in AD patients and fills an important gap of efficiency indicators for speech language therapy in our country.

Assessing deaf and hearing children`s communication in Brazil

In Brazil there are no specific tests for either signed or spoken language for deaf children. A protocol evaluating communicative abilities independent of modality of communication (sign language or spoken language), and comprising assessments of (a) pragmatic profile; (b) modality of communication and linguistic level; (c) complexity of communication; and (d) style and efficacy of communication between parent and child was administered to 127 deaf and hearing children. The children, aged 3-6 years old, were distributed in three groups: 20 with severe hearing loss, 40 with profound hearing loss and 67 normally hearing. Deaf children were found to be delayed, independent of their linguistic level and preferred modality of communication. The protocol in this study proved to be an useful instrument for gathering relevant information about the three groups of preschool children`s communicative abilities, and particularly suitable for use in countries where standardized assessments are not available. Learning outcomes: The reader will be introduced to the use of an assessment protocol comprising its development, application and data analysis. The reader will be informed about assessment of deaf children`s preferred modality of communication, by the participation of a bilingual (sign language user) professional. Communication abilities can be assessed independently of the linguistic modality. In developing countries in general, where simple and easy to administer assessments tools are scarce, such a protocol is of specific value. (c) 2010 Elsevier Inc. All rights reserved.

Crystal structure at 1.1 angstrom resolution of alpha-conotoxin PnIB: Comparison with alpha-conotoxins PnIA and GI

Conotoxins are small, cysteine-rich peptides isolated from the venom of Conus spp. of predatory marine snails, which selectively target specific receptors and ion channels critical to the functioning of the neuromuscular system. alpha-Conotoxins PnIA and PnIB are both 16-residue peptides (differing in sequence at only two positions) isolated from the molluscivorous snail Conus pennaceus. In contrast to the muscle-selective alpha-conotoxin GI from Conus geographus, PnIA and PnIB block the neuronal nicotinic acetylcholine receptor (nAChR). Here, we describe the crystal structure of PnIB, solved at a resolution of 1.1 Angstrom and phased using the Shake-and-Bake direct methods program. PnIB crystals are orthorhombic and belong to the space group P2(1)2(1)2(1) with the following unit cell dimensions: a = 14.6 Angstrom, b = 26.1 Angstrom, and c = 29.2 Angstrom. The final refined structure of alpha-conotoxin PnIB includes all 16 residues plus 23 solvent molecules and has an overall R-factor of 14.7% (R-free of 15.9%). The crystal structures of the alpha-conotoxins PnIB and PnIA are solved from different crystal forms, with different solvent contents. Comparison of the structures reveals them to be very similar, showing that the unique backbone and disulfide architecture is not strongly influenced by crystal lattice constraints or solvent interactions. This finding supports the notion that this structural scaffold is a rigid support for the presentation of important functional groups. The structures of PnIB and PnIA differ in their shape and surface charge distribution from that of GI.

A comparison of the expressive communication skills of triplet, twin and singleton children

Few studies have focused on the language acquisition of higher multiple birth sets. In this study, the communication skills of 51 triplet children are described. The measures used were: mean length of utterance; type-token ratio; conversational nets; phoneme repertoire; and number of different types of phonological processes used. The data gained were used to compare the communication skills of triplets with those of twins, singletons and normative data available in the literature. Siblings within triplet sets were also compared using language samples obtained from adult-child interactions and when the three children were playing together. The results indicated that the triplets' early communication skills were different from those of both singletons and twins. The triplets' difficulties included delayed syntactic development, limited use of different language functions and delayed phonological development. In contrast, twins' communication profile is characterised by disordered phonological development.

Simultaneous two-wavelength holographic interferometry in a superorbital expansion tube facility

A new variation of holographic interferometry has been utilized to perform simultaneous two-wavelength measurements, allowing quantitative analysis of the heavy particle and electron densities in a superorbital facility. An air test gas accelerated to 12 km/s was passed over a cylindrical model, simulating reentry conditions encountered by a space vehicle on a superorbital mission. Laser beams with two different wavelengths have been overlapped, passed through the test section, and simultaneously recorded on a single holographic plate. Reconstruction of the hologram generated two separate interferograms at different. angles from which the quantitative measurements were made. With this technique, a peak electron concentration of (5.5 +/- 0.5) x 10(23) m(-3) was found behind a bow shock on a cylinder. (C) 1997 Optical Society of America.

Homoclinic orbits and chaos in a multimode laser

We show experimentally that under certain conditions the chaotic intensity dynamics of an optically pumped NH3 bidirectional ring laser could be well described in terms of Shil'nikov homoclinic orbits and chaos. We found that the mechanism that resulted in this kind of dynamics of the laser is the competition between effects caused by the mode interaction between the forward and the backward modes of the laser and by the intrinsic single-mode dynamics of the interacting modes. (C) 1997 Optical Society of America.

Genetic algorithms for continuous optimization problems - a concept of parameter-space size adjustment

The concept of parameter-space size adjustment is pn,posed in order to enable successful application of genetic algorithms to continuous optimization problems. Performance of genetic algorithms with six different combinations of selection and reproduction mechanisms, with and without parameter-space size adjustment, were severely tested on eleven multiminima test functions. An algorithm with the best performance was employed for the determination of the model parameters of the optical constants of Pt, Ni and Cr.

The impact of staff empowerment and communication style on customer evaluations: The special case of service failure

Empowering front-line staff to deal with service failures has been proposed as a method of recovering from service breakdown and ensuring greater customer satisfaction. However, no empirical study has investigated consumer responses to empowerment strategies. This research investigates the effect on customer satisfaction and service quality of two employee characteristics: the degree to which the employee is empowered (full, limited, and none), and the employee's communication style (accommodative - informal and personal, and underaccommodative-formal and impersonal). These employee characteristics are studied within the context of service failures. Subjects were shown videotaped service scenarios, and asked to complete satisfaction and service quality ratings. Results revealed that the fully empowered employee produced more customer satisfaction than the other conditions, but only when the service provider used an accommodating style of communication. Fully empowered and nonempowered employees were not judged differently when an underaccommodating style of communication was adopted. (C) 1997 John Wiley & Sons, Inc.