F2 Transition Research Articles

American English diphthong transitions and the acoustic vowel space: A pilot comparison of two tasks

The purpose of the present study is to evaluate the potential relationship(s) between diphthong transitions and the acoustic vowel space parameters in two speaking tasks. Diphthongs are associated with acoustic changes that reflect changes in vocal tract configurations, affording unique opportunities for investigating the articulatory-acoustic link. The acoustic vowel space, a representation of monophthong vowels in a two-dimensional plane defined by the first and second formant frequencies (F1 and F2), has been widely used to interpret articulatory-acoustic consequences and to index articulatory integrity. Nevertheless, limited is known as to how diphthongs and monophthong vowels account for the acoustic working space together [Lee et al., JASA 136(4), 1880–1894 (2014)]. To add to this inquiry, transitions of American English diphthongs /ei/, /ɑɪ/, /ɑʊ/, /oʊ/, and /ɔi/, defined by the primary F2 transition, are examined with respect to the quadrilateral vowel space anchored by /i/, /æ/, /ɑ/, and /u/. The speech sounds were obtained from four male speakers in two tasks, sentence reading and connected speech, that have been shown to elicit vowel space changes. It is hypothesized that greater diphthong transitions are associated with parameters corresponding to a larger vowel space. Findings will be discussed within the framework of the acoustic theory.

Effects of Speaking Rate on Variability of Second Formant Frequency Transitions in Dysarthria

Introduction: This study examined the utility of multiple second formant (F2) slope metrics to capture differences in speech production for individuals with dysarthria and healthy controls as a function of speaking rate. In addition, the utility of F2 slope metrics for predicting severity of intelligibility impairment in dysarthria was examined. Methods: Twenty three speakers with Parkinson’s disease and mild to moderate hypokinetic dysarthria (HD), 9 speakers with various neurological diseases and mild to severe ataxic or ataxic-spastic dysarthria (AD), and 26 age-matched healthy control speakers (CON) participated in a sentence repetition task. Sentences were produced at habitual, fast, and slow speaking rate. A variety of metrics were derived from the rising F2 transition portion of the diphthong /ai/. To obtain measures of intelligibility for the two clinical speaker groups, 15 undergraduate SLP students participated in a transcription experiment. Results: Significantly shallower slopes were found for the speakers with HD compared to control speakers. Steeper F2 slopes were associated with increased speaking rate for all groups. Higher variability in F2 slope metrics was found for the speakers with AD compared to the two other speaker groups. For both clinical speaker groups, there was a negative association between intelligibility and F2 slope variability metrics, indicating lower variability in speech production was associated with higher intelligibility. Discussion: F2 slope metrics were sensitive to dysarthria presence, dysarthria type, and speaking rate. The current study provided evidence that the use of F2 slope variability measures has additional value to F2 slope averaged measures for predicting severity of intelligibility impairment in dysarthria.

Second Formant Transition Characteristics in Persian-Speaking People With Broca’s Aphasia

Background and Objectives: This study aims to examine the acoustic characteristics of the second formant (F2) transition produced by Persian-speaking Broca’s aphasics compared to normal speakers. Methods: Eight subjects diagnosed with Broca’s aphasia and eight normal speakers participated in this study. The subjects produced six words (/ bâd / - / pâ / - / tâb / - / dâs / - / kâr / and / gâz /). The samples were analyzed using PRAAT and the F2 transition was measured for these words. F2 values were compared to the data available in the literature. Results: Since the data distribution was abnormal in this study, the Mann-Whitney U test was applied. The results of this study show that the mean of the second formant transition in healthy people and people with aphasia are significantly different from each other in the words /Bâd/ and /Kâr/ (P<0.05), in which the mean of the second formant transition in both words was higher in the group of people with aphasia compared to healthy people. The results also showed that the mean of the second-formant transition in these six words is significantly different and higher in the group of aphasic people compared to the group of healthy people (P<0.05). Conclusion: In patients with Broca’s aphasia, the F2 value was higher than normal speakers. The nature of Broca’s aphasia suggests that subjects with Broca’s aphasia show higher F2 values. Also, the focus on Broca’s aphasia indicates difficulties in applying secondary articulation to a sufficient extent. The results of these studies are likely clinically applicable in particular to improving assessment approaches and therapeutic programs for Persian speakers with Broca’s aphasia.

Structural, morphological, and photoluminescence properties of RE (RE = Dy3+ , Eu3+ , Sm3+ )-doped CaAlBO4 phosphor synthesized by combustion method.

The CaAlBO4 :RE (RE = Dy3+ , Eu3+ , Sm3+ ) phosphor were prepared via combustion synthesis and studied by X-ray diffraction (XRD), Fourier-transform infrared (FTIR) analysis, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), photoluminescence (PL) spectra and CIE coordinates. The phase formation of the obtained phosphor was analyzed by XRD and the result was confirmed by standard PDF Card No. 1539083. XRD data successfully indicated pure phase of CaAlBO4 phosphor. The crystal structure of CaAlBO4 phosphor is orthorhombic with space group Ccc2 (37). The SEM image of CaAlBO4 phosphor reveals an agglomerated morphology and non-uniform particle size. The EDS image provides evidence of the elements present and the chemical makeup of the materials. Under the 350 nm excitation, the emission spectrum of Dy3+ activated CaAlBO4 phosphor consists of two main groups of characteristic peaks located at 484 and 577 nm which are ascribed to 4 F9/2 → 6 H15/2 and 4 F9/2 → 6 H13/2 transition of Dy3+ respectively. The PL emission spectra of CaAlBO4 :Eu3+ phosphor shows characteristics bands observed around 591 and 613 nm, which corresponds to 5 D0 → 7 F1 and 5 D0 → 7 F2 transition of Eu3+ respectively, upon 395 nm excitation wavelength. The emission spectra of Sm3+ activated CaAlBO4 phosphor shows three characteristic bands observed at 565, 601 and 648 nm which emits yellow, orange and red color. The prominent emission peak at the wavelength 601 nm, which is attributed to 4 G5/2 → 6 H7/2 transition, displays an orange emission. The CIE color coordinates of CaAlBO4 :RE (RE = Dy3+ , Eu3+ , Sm3+ ) phosphor are calculated to be (0.631, 0.368), (0.674, 0.325) and (0.073, 0.185). As per the obtained results, CaAlBO4 :RE (RE = Dy3+ , Eu3+ , Sm3+ ) phosphor may be applicable in eco-friendly lightning technology.

Luminescence properties of red phosphor YVO4:Eu3+, Ba2+

Solid-state reaction can resoundingly compound phosphors Y0.95−xBaxVO4:5%Eu3+ (0 ≤x ≤ 0.10). The solid samples could be recognized isomorphs. Their luminescent performance can be researched under UV and VUV stimulation. Managing at 619 nm, a powerful expansive absorption could be increased by integrating Ba2+ into the lattices of YVO4:Eu3+. Stimulated by 254 nm or 147 nm, phosphors of Y0.95−xBaxVO4: Eu3+(0 ≤x ≤ 0.1) demonstrated powerful red light emitting at around 619 nm according with the electric dipole 5D0 -7F2 transition of Eu3+. With doping of Ba2+, the luminous intensity of Y0.95−xBaxVO4: Eu3+(0 ≤x ≤ 0.1) increased and then reduced, the best luminescence intensity along with integration of 5 mol% Ba2+.

Effect of Speaker Age on Listener Perceptions of Word-Final /l/.

This study investigated an effect of speaker age on listeners' perception of word-final /l/ produced by child and adult speakers of Southern White Vernacular English, a dialect that shows higher rates of word-final /l/ vocalization than other dialects of English. Stimuli included children and adults' word-final /l/ embedded in monosyllabic words in two vowel contexts (/i, ɪ/ and /ɔ, ɑ/). A total of 25 monolingual adult listeners listened to each word and were asked to judge the /l/-likeness using a visual analog scale. Average listener ratings and three acoustic measures (F2 transition rate [F2 TR] and F2-F1 [Hz] values at 20% and 80% time points along the vowel-/l/ duration) were analyzed. Adult productions were rated more as correct /l/ than those of children in both vowel contexts, despite the similarity in their F2 TR and F2-F1 values at the 80% time point. Correlation between the acoustic measures and the average listener ratings were weak for all three measures for adults' productions. For children's productions, while the correlation with F2 TR values were weak, moderate significant correlations were found for F2-F1 values at the 20% and 80% time points. In terms of vowel context, word-final /l/ in the high front vowel context was rated more as /l/ than those in low back vowel context. Findings suggest that listeners are more likely to accept word-final /l/ as being correct when produced by adult speakers, regardless of their acoustic characteristics, but more likely to perceive an error when produced by a child and attend more to acoustic information for their perceptual judgment. This highlights the importance of considering children's dialectal background when judging word-final /l/, which is more likely to be vocalized in certain dialects and certain vowel contexts, and thus can be misjudged without such consideration.

Eu3+ Activated Red Phosphor Ca3 YAl3 B4 O15 with Low Thermal Quenching Behavior.

This paper reports a sequence of Ca3 YAl3 B4 O15 : xEu3+ red phosphor prepared by a high-temperature solid-state reaction. At the excitation of 396 nm, the samples emit intense red emission centered around 623nm, which can be attributed to the 5 D0 →7 F2 transition of the Eu3+ ion. The results showed that the optimum Eu3+ doping concentration of Ca3 YAl3 B4 O15 : Eu3+ phosphor is x= 80mol%, and the concentration quenching mechanism of Ca3 YAl3 B4 O15 : Eu3+ red phosphor belongs to the exchange coupling between Eu3+ ions. The CIE coordinate and color purity of Ca3 Y0.2 Al3 B4 O15 : 0.8Eu3+ were calculated as (0.6375, 0.3476) and 95.5%, respectively. Moreover, the red emission of the obtained phosphor Ca3 YAl3 B4 O15 : 0.8Eu3+ exhibits low thermal quenching behavior with an intensity retention rate of 92.85% at 150 °C. The above results manifest that the Eu3+ -activated Ca3 YAl3 B4 O15 phosphor is predicted to be a promising red luminescent component for the white light-emitting diodes.

Thermally stable red luminescence from Eu3+ -activated telluro zinc phosphate glass under near-ultraviolet light excitation for photonic applications.

Telluro zinc phosphate (TZP) glasses doped with different concentrations of Eu3+ ions were prepared and their physical, structural, and luminescence properties were studied in detail to reveal the utility of the as-prepared glass for white light-emitting diode (w-LED) applications. The broad hump in the diffraction pattern specified the amorphous behaviour of the TZP glass. The various vibrational shoulder linkages were characterized using the Fourier transform infrared (FT-IR) spectroscopy. The optical absorption spectrum was measured in the ultraviolet (UV)-visible (Vis) light region for the Eu3+ -doped TZP (TZPE) glass and the optical band gap was found to be 3.12 eV. Eu3+ -doped TZP glasses showed several emission peaks in the visible region including an intense red emission peak due to the 5 D0 →7 F2 transition under an excitation wavelength of λex = 393 nm, which was matched with the emitting wavelength of the near-UV LED chip. Commission Internationale de I'Eclairage (CIE)chromaticity coordinates were situated in the red region and nearly matched with the coordinates of the commercial red phosphor (Y2 O3 S:Eu3+ ). The decay profile of the TZPE50 glass exhibited a single exponential fit with a decay time ( of 1.76 ms. Temperature-dependent photoluminescence (TDPL) studies demonstratethat the as-prepared glass consist of excellent thermal stability. The detailed analysis and results confirmed that the red-emitting TZPE glasses were potential candidates for white-LED and other photonic applications.

Enhanced electrocatalytic water splitting by Sm and Gd-doped ceria electrocatalysts on Ni foam substrate

CeO2 is attractive for water splitting due to its various valence oxidation states, however, its catalytic performance in alkaline medium is challenging. In this study, we synthesized novel ceria-based electrocatalysts: Gd-doped CeO2 nanocrystals (GDC) and Sm-doped CeO2 nanospheres (SDC) on Ni foam using sol–gel and one-step hydrothermal methods, respectively. These ceria-based electrocatalysts, GDC and SDC, depict excellent activity in the OER and HER, respectively. The GDC/NF showed promising OER performance, achieving an exceptional overpotentials of 300 and 420 mV to keep current densities of 10 and 100 mA cm−2, respectively. In addition, SDC/NF exhibited excellent HER activity with overpotentials of 117 and 325 mV to reach current densities of 10 and 100 mA cm-2, respectively. Furthermore, both GDC and SDC were ultra-stable at a fixed current density of 50 mA cm−2 for 25 h. Moreover, the complete anion-exchange membrane (GDC/NF||SDC/NF) demonstrated 1.6 Vcell to accomplish 10 mA cm-2 current density, with ultra-durability for 40 h at 50 mA cm-2. The versatile electrochemical performance of ceria-based catalysts is attributed to diverse-valence Ce3+/Ce4+ redox states and positive entropy contribution of the f0–f1 transition. Notably, doping with Gd and Sm led to an easy and strong reduction owing to the oxygen voids created and hydroxyls. Moreover, dopants stabilized ceria and assisted the generation of metal–H groups, which improved the kinetic activity of ceria for electrochemical water splitting.

PRESSURE DEPENDENCES OF LINE PARAMETERS OF THE 𝝂𝟑 + 𝝂𝟒 R(7)F1 TRANSITION OF METHANE DILUTED IN NITROGEN USING THE HARDAND SOFT-COLLISION MODELS

In this work, the affection of the Dicke narrowing effect on the spectral shape of the 𝜈3 + 𝜈4 R(7)F1 transition of methane diluted in nitrogen was studied using the Hard- and the Soft- collision line-shape models. Room-temperature absorption spectra of CH4 broadened by N2 were measured at a wide range of pressure using a difference-frequency laser spectrometer. Measured spectra of the studied transition were then one-by-one fitted with the simple Voigt profile as well as the two line-shape models considered the Dicke narrowing effect at two different assumptions of velocity-changing collisions: hard- and soft- collisions. The obtained results confirmed that using these two models leads to better qualities of fit with respect to the Voigt profile. Pressure-dependences of the line-shape parameters were also observed for the considered transition. The results showed a good agreement with other studies.

Spectroscopic characteristics and optimization of (Gd3+/Eu3+) co-doped in alkal borate glasses for solid state lighting material

The physical, structural, and luminescence properties of lithium aluminum borate glasses as a function of Gd2O3 and Eu2O3 concentration were reported. The glasses composition of 25Li2O–5Al2O3-YGd2O3-(70-Y-Z)B2O3-ZEu2O3 system was successfully synthesized through a conventional melt-quenching technique. The various Gd2O3 concentration, 2.5 mol% is suitably added into the host composite, supporting by X-ray induced luminescence and photoluminescence analysis. The influence of the Eu2O3 concentration doped glasses system has been investigated in different concentrations of Eu3+ ions. It was found that the emission intensity increase with an increase of Eu2O3 concentration up to 3.0 mol% (luminescence quenching. The maximum intensity peaks were located at 614 nm (red emission), which was due to 5 D0→7 F2 transitions of Eu3+ ions. The decay profile is measured to prove the occurrence of maximum energy transfer efficiency (Eu3+-Eu3+) obtained is as high as 15.36% for their potential candidature in solid state device applications.

АКУСТИЧНИ ОСОБЕНОСТИ НА МЕКИ ВЕЛАРНИ СЪГЛАСНИ ОТ ИЗТОЧНОБЪЛГАРСКИ И ЗАПАДНОБЪЛГАРСКИ ТИП / ACOUSTIC FEATURES OF THE SOFT VELAR CONSONANTS OF THE EASTERN BULGARIAN AND THE WESTERN BULGARIAN TYPE

This pilot study discusses the results of the measurement of the acoustic properties of the soft velar plosives [gj] [kj] of the eastern Bulgarian and the western Bulgarian types of articulation in CVC isolated syllables in comparison with the properties of the hard velar plosives [g] and [k] before the vowel [a] and the front vowel [ɛ]. According to the Bulgarian phonetic literature velar consonants preceding front vowels are realized as allophones of the hard consonants, whose articulation and acoustic features are very similar to those of their soft correlates. For the purposes of this study, we chose several acoustic parameters – consonant duration, formant transition duration (F2), F2 onset and F2 offset (Hz), F3 onset and F3 offset (Hz) – and measured them with the Praat software. The main goal is to establish the degree of differentiation between the eastern Bulgarian and the western Bulgarian articulation with respect to velar plosives. The results show that the F2 transition duration is a distinctive feature that sets apart the eastern and the western types of articulation, as well as hard and soft velar plosives. The type of F3 transition can also be considered as a differrentiator between soft and hard velar plosives. The consonant duration could hardly serve to distinguish between the two types of articulation but is relevant for the differentiation of voiced vs. voiceless plosives. Keywords: velar plosives, soft consonants, acoustic measures, Bulgarian, western articulation, eastern articulation

Metabolic signatures across the full spectrum of non-alcoholic fatty liver disease

Background & AimsNon-alcoholic fatty liver disease (NAFLD) is a progressive liver disease with potentially severe complications including cirrhosis and hepatocellular carcinoma. Previously, we have identified circulating lipid signatures associating with liver fat content and non-alcoholic steatohepatitis (NASH). Here, we develop a metabolomic map across the NAFLD spectrum, defining interconnected metabolic signatures of steatosis (non-alcoholic fatty liver, NASH, and fibrosis).MethodsWe performed mass spectrometry analysis of molecular lipids and polar metabolites in serum samples from the European NAFLD Registry patients (n = 627), representing the full spectrum of NAFLD. Using various univariate, multivariate, and machine learning statistical approaches, we interrogated metabolites across 3 clinical perspectives: steatosis, NASH, and fibrosis.ResultsFollowing generation of the NAFLD metabolic network, we identify 15 metabolites unique to steatosis, 18 to NASH, and 15 to fibrosis, with 27 common to all. We identified that progression from F2 to F3 fibrosis coincides with a key pathophysiological transition point in disease natural history, with n = 73 metabolites altered.ConclusionsAnalysis of circulating metabolites provides important insights into the metabolic changes during NAFLD progression, revealing metabolic signatures across the NAFLD spectrum and features that are specific to NAFL, NASH, and fibrosis. The F2–F3 transition marks a critical metabolic transition point in NAFLD pathogenesis, with the data pointing to the pathophysiological importance of metabolic stress and specifically oxidative stress.Clinical Trials registrationThe study is registered at Clinicaltrials.gov (NCT04442334).Lay summaryNon-alcoholic fatty liver disease is characterised by the build-up of fat in the liver, which progresses to liver dysfunction, scarring, and irreversible liver failure, and is markedly increasing in its prevalence worldwide. Here, we measured lipids and other small molecules (metabolites) in the blood with the aim of providing a comprehensive molecular overview of fat build-up, liver fibrosis, and diagnosed severity. We identify a key metabolic ‘watershed’ in the progression of liver damage, separating severe disease from mild, and show that specific lipid and metabolite profiles can help distinguish and/or define these cases.

The temporal unfolding of register reveals distinct mechanisms at play: A case study of Western Khmer

Register distinctions are a type of suprasegmental contrasts manifested in several acoustic dimensions, e.g., pitch, vowel quality, and voice quality. However, several aspects of register production remain unclear (Brunelle & Kirby, 2016). In this paper, we focus on whether a target laryngeal configuration may be responsible for the multiplicity of acoustic cues to register. We approach this question through a production study of Western Khmer, an Austronesian language spoken in Chanthaburi, Thailand. Data were collected from 19 speakers producing words with modal or breathy register in a carrier sentence. The measurements we took are trajectories of F0, F1, H1*-H2*, and H1*-A1*. Our results show that all cues are significant in distinguishing the two registers, confirming static measurement results in the previous literature (Wayland, 2001). However, a dynamic study of these register cues reveals a dissociation in their temporal alignment. The F1 transitions that mark changes in vowel quality are not aligned with the transitions of H1*-H2* and H1*-A1* that mark changes in voice quality. These findings suggest that separate asynchronous mechanisms may be responsible for the voice quality and vowel quality components of register production.

Synthesis and luminescence characterization of Eu3+ -doped Ca7 Mg2 (PO4 )6 phosphor for eco-friendly white light-emitting diodes and thermoluminescence dosimetric applications.

A Eu3+ -activated Ca7 Mg2 (PO4 )6 phosphor was prepared at high temperature (800°C) using a solid-state reaction method. The crystal structure, phase formation of the prepared phosphor was characterized using X-ray diffraction patterns and Fourier transformed infrared analysis. The luminescence properties of the synthesized phosphor were characterized using photoluminescence and thermoluminescence techniques. The prepared phosphor showed two emission peaks at 594 nm with an orange colour due to the 5 D0 →7 F1 transition and at 612 nm a red colour due to the 5 D0 →7 F2 transition under 396 nm near-UV excitation. The prepared phosphors were irradiated with different doses of γ-rays from a 60 Co gamma irradiation source. Thermoluminescence glow curves for this sample phosphor were obtained using a Nucleonix 1009I TL reader. Synthesized phosphor samples were exposed to a 3.6 kGy dose of γ-rays. The thermoluminescence glow curve of the Ca7 Mg2 (PO4 )6 :0.05 mol%Eu3+ phosphor showed maximum intensity at all concentrations of Eu3+ ions. The Ca7 Mg2 (PO4 )6 :0.05 mol%Eu3+ phosphor was irradiated with different doses of 60 Co γ-irradiation and a linear response was observed between 0.6 kGy and 3.6 kGy. Trapping parameters such as activation energy, frequency factor and order of kinetics were calculated. The CIE chromaticity diagram showed the colour coordinates of the synthesized phosphor in the orange and red regions of the visible spectrum; this spectral feature revealed high colour purity and excellent chromaticity coordinate characteristics. Photoluminescence and thermoluminescence properties revealed that the prepared phosphor could be a potential red-emitting phosphor for eco-friendly white light generation and an excellent thermoluminescent dosimeter material for thermoluminescence dosimetric applications.

Formant Trajectory Patterns of American English /l/ Produced by Adults and Children.

Purpose Most acoustic and articulatory studies on /l/ have focused on either duration, formant frequencies, or tongue shape during the constriction interval. Only a limited set of data exists for the transition characteristics of /l/ to and from surrounding vowels. The aim of this study was to examine second formant (F2) transition characteristics of /l/ produced by young children and adults. This was to better understand articulatory behaviors in the production of /l/ and potential clinical applications of these data to typical and delayed /l/ development. Method Participants included 17 children with typically developing speech between the ages of 2 and 5 years, and 10 female adult speakers of Southern American English. Each subject produced single words containing pre- and postvocalic /l/ in two vowel contexts (/i, ɪ/ and /ɔ, ɑ/). F2 transitions, out of and into /l/ constriction intervals from the adjacent vowels, were analyzed for perceptually acceptable /l/ productions. The F2 transition extent, duration, and rate, as well as F2 loci data, were compared across age groups by vowel context for both pre- and postvocalic /l/. Results F2 transitions of adults' /l/ showed a great similarity across and within speakers. Those of young children showed greater variability, but became increasingly similar to those of adults with age. The F2 loci data seemed consistent with greater coarticulation among children than adults. This conclusion, however, must be regarded as preliminary due to the possible influence of different vocal tract size across ages and variability in the data. Conclusions The results suggest that adult patterns can serve as a reliable reference to which children's /l/ productions can be evaluated. The articulatory configurations associated with the /l/ constriction interval and the vocal tract movements into and out of that interval may provide insight into the underlying difficulties related to misarticulated /l/.

Synthesis and optical properties of GdVO4: Eu3+ phosphor

In the present work, we have synthesized GdVO4 doped Eu3+ using a facile sol-gel method and analysed the effect of concentration variation and annealing temperature on the optical properties. Tetragonal (I41/amd) zircon type crystal structure of the material was confirmed by x-ray diffraction (XRD) study. The photoluminescence (PL) spectra were recorded with an ultraviolet (UV) excitation of wavelength 325 nm. GdVO4 doped Eu3+ (1 mol%) gives prominent red emission. This optimized sample was annealed at different temperature and as annealing temperature raises, the crystallinity of the material increases resulting in the improved emission intensity. The emission spectra of this phosphor exhibit intense peaks at wavelengths 593 nm (orange) and 618 nm (red) which corresponds to 5D0-7F1, 5D0 -7F2 transitions of Eu3+ ions. 5D0 -7F2, the electric dipole transition is dominant indicating that Eu3+ ions situated at a non-centrosymmetric site in the crystal structure. GdVO4: Eu3+(1 mol%) annealed at 800 °C gives eminent red emission which can be further used as the potential candidate for bioimaging, lighting, temperature sensing and display devices.

Preparation and luminescence properties of Tb3+ -doped garnet Y2 Mg2 Al2 Si2 O12 luminescent materials.

We prepared Y2 Mg2 Al2 Si2 O12 :xTb3+ (x = 0.02, 0.04, 0.06, 0.08, 0.10, 0.12, 0.14 and 0.16) luminescent materials using a nodulizing procedure. The phase and luminescence properties of these materials were investigated. X-ray diffraction results demonstrated that Tb3+ ions doped into Y2 Mg2 Al2 Si2 O12 hosts successfully and the Y2 Mg2 Al2 Si2 O12 :xTb3+ materials showed a pure cubic phase. Y2 Mg2 Al2 Si2 O12 :xTb3+ materials had the characteristic Tb3+ emission bands derived from 5 D4 →7 F6 , 7 F5 , 7 F4 , and 7 F3 transitions when excited at 365 nm. The green emission band that derived from the 5 D4 →7 F5 transition was highest due to the high possibility of both electric-dipole and magnetic-dipole transitions. Emission spectra indicated that the critical concentration of Tb3+ in the Y2 Mg2 Al2 Si2 O12 host was 0.14. The concentration quenching of Y2 Mg2 Al2 Si2 O12 :Tb3+ was derived from a dipole-dipole interaction.

Unusual Magnetic Field Responsive Circularly Polarized Luminescence Probes with Highly Emissive Chiral Europium(III) Complexes.

Chirality is ubiquitous within biological systems where many of the roles and functions are still undetermined. Given this, there is a clear need to design and develop sensitive chiral optical probes that can function within a biological setting. Here we report the design and synthesis of magnetically responsive Circularly Polarized Luminescence (CPL) complexes displaying exceptional photophysical properties (quantum yield up to 31 % and |glum| up to 0.240) by introducing chiral substituents onto the macrocyclic scaffolds. Magnetic CPL responses are observed in these chiral EuIII complexes, promoting an exciting development to the field of magneto‐optics. The |glum| of the 5D0 → 7F1 transition increases by 20 % from 0.222 (0 T) to 0.266 (1.4 T) displaying a linear relationship between the Δglum and the magnetic field strength. These EuIII complexes with magnetic CPL responses, provides potential development to be used in CPL imaging applications due to improved sensitivity and resolution.

Articulatory strategies and their acoustic consequences: Investigating tongue retraction and lip protrusion tradeoffs in talkers with amyotrophic lateral sclerosis

Observations of tradeoffs between lip protrusion and tongue retraction during productions of /u/ suggest that typical talkers can vary their articulatory strategies without affecting their acoustic output. In this study we tested the hypothesis that talkers with dysarthria due to amyotrophic lateral sclerosis (ALS) may take advantage of such trading relations and exaggerate lip protrusion to preserve speech acoustics in the presence of impaired tongue retraction. 14 talkers with mild to moderate dysarthria due to ALS (8 females, 6 males) and 14 age- and sex-matched controls produced “Tomorrow Mia may buy you toys again” five times at their habitual rate. Speech kinematics were recorded using electromagnetic articulography. Tongue retraction and lip protrusion were measured by calculating the displacement of the posterior tongue and upper lip sensors in the anterior-posterior dimension of the midsagittal plane during the production of “buy you.” F2 transition extent was measured by calculating the change in F2 (F2 maximum-minimum) during “you.” Group means of kinematic and acoustic variables were compared to determine between-group differences in articulatory and acoustic performance. Linear regressions were used to determine the contribution of each articulator as well as the combined effect of both articulators to F2 transition extent within each group.