Relative Intensity Measurements Research Articles

CAN SIMPLE REACTION TIME TO A VISUAL STIMULUS BE USED AS A MEASURE OF THE BALANCE TASK INTENSITY?

Correctly determining the frequency, intensity and duration of balance tasks (BT) is crucial for effective balance training. While the frequency and BT duration are well defined, understanding BT intensity remains limited. Higher BT intensity demands greater attentional capacity for postural control. To assess the role of attention in postural control the dual-task paradigm including BT with reaction time (RT) is often used, suggesting RT as a potential measure of BT relative intensity. The study aimed to determine whether simple RT can be a surrogate for the relative BT intensity. Twenty randomly selected participants performed six repetitions of two-legged and one-legged stances on firm and compliant surfaces on a force plate. During the execution of the BT, the participants had to react on illumination of the light by pressing a switch held in their dominant hand. The center of pressure (COP) velocity and the RT were investigated. The BT were categorized into low, moderate and high intensities. The results showed a significant increase in COP velocity from low to high intensity BT (p=0.001; η2=0.79). Moderate intensity BT resulted in a 123.6% increase in COP velocity compared to the low intensity BT. During high-intensity BT COP velocity increased by 244.2 % (p < 0.001). There were no differences in RT between different BT intensities (p=0.596; η2=0.03). The results suggest that RT may not accurately reflect the BT intensity. Therefore, it can be concluded that simple visual RT could not be used as a measure of relative intensity of BT.

Fluorination effects on non-covalent binding forces: A rotational study on the 2-(trifluoromethyl)acrylic acid–water complex

This study explores the effects of the −CF3 group on non-covalent interactions through a comprehensive rotational investigation of the 2-(trifluoromethyl)acrylic acid–water complex. Employing Fourier transform microwave spectroscopy complemented by quantum chemical calculations, two isomers, i.e., s-cis and s-trans structures, have been observed in the pulsed jet. Based on relative intensity measurements, the s-cis to the s-trans population ratio was experimentally estimated to be ∼ 1:1.2. Subsequently, a comparison of the non-covalent interactions was carried out between the three similar complexes, acrylic acid–water, methacrylic acid–water, and 2-(trifluoromethyl)acrylic acid–water, offering quantitative insights into fluorination affecting the strength of the formed hydrogen bonds important, e.g., in molecular recognition.

Conformational equilibria in acrolein-CO2: the crucial contribution of n → π* interactions unveiled by rotational spectroscopy.

Using gas phase Fourier-transform microwave spectroscopy complemented by theoretical analysis, this study delivers a comprehensive depiction of the physical origin of the 'n → π* interaction' between CO2 and acrolein, one of the most reactive aldehydes. Three distinct isomers of the acrolein-CO2 complex, linked through a C⋯O tetrel bond (or n → π* interaction) and a C-H⋯O hydrogen bond, have been unambiguously identified in the pulsed jet. Relative intensity measurements allowed estimation on the population ratio of the three isomers to be T1/T2/C1 ≈ 25/5/1. Advanced theoretical analyses were employed to elucidate the intricacies of the noncovalent interactions within the examined complex. This study not only sheds light on the molecular underpinnings of n → π* interactions but also paves the way for future exploration in carbon dioxide capture and utilization, leveraging the fundamental principles uncovered in the study of acrolein-carbon dioxide interactions.

Structure and dynamics of 3'-aminoacetophenone and 4'-aminoacetophenone from rotational spectroscopy.

The rotational spectra of 4'-aminoacetophenone, and those of two conformers (Z and E arrangement of the CO and NH2 groups) of 3'-aminoacetophenone and their 13C and 15N isotopologues were investigated both in the microwave (2-8 GHz) and millimetre (59.6-74.4 GHz) frequency regions using chirped pulse Fourier transform and free-jet absorption techniques, respectively. The spectra consist of μa and μb type lines that show a hyperfine structure due to both the nuclear quadrupole coupling of the 14N nucleus and the methyl internal rotation. Relative intensity measurements show that the Z form in 3'-aminoacetophenone is favoured with respect to E and the measured energy difference upper limit is about 5.5(1) kJ mol-1. Barriers to methyl internal rotation are V3 = 7.04(2) and 6.530(6) kJ mol-1 for 3'(Z)- and 4'-aminoacetophenone, respectively. Flexible model analyses of the amino inversion motion based on ab initio potential energy paths, suggest that the corresponding vibrational splitting increases up to 78% from aniline to 3'(E)-, 3'(Z), and 4-aminoacetophenone. However, due to supersonic expansion cooling, no splitting related to amine inversion is observed.

High resolution curvature sensor based on enhanced backscattering in side polished optic fiber

A high-resolution curvature sensor based on enhanced backscattering in side polished optic fiber is proposed and experimentally investigated. Directional curvature sensor fabrication procession and operating principle are introduced. A push–pull structure with 2 side polished curvature sensors sticking on opposite sides of an elastic beam is used to enhance sensitivity and responsive linearity. Experiments are carried out by high accuracy relative intensity (RI) measurement system based on modified pulse self-referencing technology. Experimental results show that curvature sensor can achieve a sensitivity of 15.21 dB/m−1 in the curvature range of −0.48–0.48 m−1, and the curvature resolution is as low as 2 × 10−5m−1.

The Conformations of Isolated Gallic Acid: A Laser-Ablation Rotational Study

The rotational spectrum of laser-ablated gallic acid has been recorded using CP-FTMW spectroscopy. Two rotamers have been detected, and their rotational spectra have been assigned and analyzed to obtain the molecular spectroscopic parameters. The observed rotamers have been unambiguously identified in the light of theoretical computations, based on the comparison of the experimental line intensities and rotational parameters with the rotational constants and electric dipole moments predicted from theoretical calculations. The values of the planar inertial moments confirm that the observed conformers are planar, and their relative stability and population have been determined from relative intensity measurements. The B3LYP-D3/6-311++G(2d,p) level has been shown to be the best method among a series of levels normally used to predict the rotational parameters in rotational spectroscopy. In the observed conformers, the three adjacent OH groups are arranged in a sequential form, and the only difference between them lies in the orientation of the COOH group. Although weak attractive OH···O interactions seem to exist, the analysis of the electron density topology does not show the existence of any critical point corresponding to these interactions.

Rotational spectroscopy of urea up to 500 GHz: The ground and eight excited vibrational states

Urea, ((NH2)2CO) is an important industrial and biological molecule. The new generation of the submillimeter telescopes, in particular ALMA, allows detection of extraterrestrial molecular spectra at unprecedented spatial and spectral resolutions. Some of the data presented here facilitated the recent definitive identification of urea in the interstellar medium (Belloche et al. Astron. & Astrophys. 628 (2019) A10:1-62). Its detection yields valuable insight into the mechanisms governing formation of complex prebiotic interstellar molecules. This paper reports spectroscopic analysis of the broadband rotational spectra of urea in the 210–500 GHz spectral range for the vibrational ground state and eight lowest excited vibrational states. The lowest excited vibrational state is only 61 cm−1 above the ground state and could be a useful temperature marker for astrophysical urea. The next two lowest pairs of excited states show significant interstate coupling, which has been successfully fitted with a Coriolis coupling model. Higher vibrational states also show evidence of significant coupling. Intensities of some rotational transitions of urea display nuclear spin statistical weights arising from the equivalence of the two ammonia groups, which enabled the assignment of symmetric and antisymmetric vibrational symmetry to the six lowest studied excited states. The vibrational energies of the new states have been determined from extensive relative intensity measurements and, together with vibrational symmetry, give insight into the highly anharmonic vibrational energy level structure.

Symmetry Breaking Charge Transfer in DNA-Templated Perylene Dimer Aggregates.

Molecular aggregates are of interest to a broad range of fields including light harvesting, organic optoelectronics, and nanoscale computing. In molecular aggregates, nonradiative decay pathways may emerge that were not present in the constituent molecules. Such nonradiative decay pathways may include singlet fission, excimer relaxation, and symmetry-breaking charge transfer. Singlet fission, sometimes referred to as excitation multiplication, is of great interest to the fields of energy conversion and quantum information. For example, endothermic singlet fission, which avoids energy loss, has been observed in covalently bound, linear perylene trimers and tetramers. In this work, the electronic structure and excited-state dynamics of dimers of a perylene derivative templated using DNA were investigated. Specifically, DNA Holliday junctions were used to template the aggregation of two perylene molecules covalently linked to a modified uracil nucleobase through an ethynyl group. The perylenes were templated in the form of monomer, transverse dimer, and adjacent dimer configurations. The electronic structure of the perylene monomers and dimers were characterized via steady-state absorption and fluorescence spectroscopy. Initial insights into their excited-state dynamics were gleaned from relative fluorescence intensity measurements, which indicated that a new nonradiative decay pathway emerges in the dimers. Femtosecond visible transient absorption spectroscopy was subsequently used to elucidate the excited-state dynamics. A new excited-state absorption feature grows in on the tens of picosecond timescale in the dimers, which is attributed to the formation of perylene anions and cations resulting from symmetry-breaking charge transfer. Given the close proximity required for symmetry-breaking charge transfer, the results shed promising light on the prospect of singlet fission in DNA-templated molecular aggregates.

The potential of microcalorimeter X-ray spectrometers for measurement of relative fluorescence-line intensities

We have previously used an array of cryogenic microcalorimeters with 4 eV energy resolution to measure emission-line profiles and energies of the characteristic L-shell X rays of four elements of the lanthanide series: praseodymium, neodymium, terbium, and holmium. We consider the power of the same data set for the estimation of the lines’ relative intensities. Intensities must be corrected for detector efficiency and self-absorption, and we estimate uncertainties on the corrections. These data represent one of the first uses of cryogenic energy-dispersive sensors to estimate the relative intensities of X-ray fluorescence lines. They show that a future measurement of thin-film samples with microcalorimeter detectors could achieve systematic uncertainties below 1% on relative line intensities over a broad energy range.

Which-way identification by an asymmetrical double-slit experiment with monochromatic photons

Recently, a laser beam asymmetrical double-slit experiment was proposed and performed, concerning ontological physical reality in quantum mechanics, under an assumption of single-photon interference. In the present study, by controlling better for saturation effects and upgrading the slit’s shape, we succeed in producing new interference samples with acceptable quality. Applying almost the same geometrical set-up, the present experiment makes the ”which-way” identification with higher experimental confidence. In the results, the ontological which-way effect observed in our recent experiment is well reconfirmed without any additional measurement of relative integral intensity.

Rotational spectra and conformational analysis of 2-bromobutane

The rotational spectra of 2-bromobutane were obtained by using a chirped-pulse Fourier-transform microwave (CP-FTMW) spectrometer in the frequency range 8–18 GHz. Hyperfine structures of both bromine isotopologues (I = 3/2) for the three conformers (G+, A, and G−) have been investigated to determine the rotational constants, centrifugal distortion constants, and nuclear quadrupole coupling constants of bromine (Br). The conformational compositions for G+, A, and G− in the supersonic jet, estimated by relative intensity measurements, are 55%, 28%, 17%, respectively, for the 79Br species, and 52%, 33%, 15%, respectively, for the 81Br species. However, the small zero-point energy differences of isotopomers can be negligible and can be considered as an average value instead of individual values, which is 54%, 30%, 16% for G+, A, and G− species. The nuclear quadrupole coupling tensors (χxx, χyy, and χzz) of Br and the quadrupolar angles were obtained, and the χzz value of 2-bromobutane is compared with those of other alkyl bromides. The spectroscopic constants, rs coordinates of Br and the dipole moments of the most stable G+ conformer are predicted well from the ab initio calculations at the MP2/6–311++G(2d,2p) level.

3D printing of Fresnel lenses with wavelength selective tinted materials

Well-established manufacturing processes for Fresnel lenses fabrication are available. However, adapting additive manufacturing is often desirable, as it opens a plethora of design and manufacturing possibilities. The current study aims to demonstrate the feasibility of 3D printing of optical devices such as Fresnel lenses with customized designs and optical properties. The study investigates the 3D modeling of Fresnel lenses with a computer-aided design tool and selecting suitable materials for the 3D printing process. The process parameters of digital light processing 3D printing were tailored to get the desired features with accurate geometric dimensions in the final printed lenses. The suitable ink colors were introduced into the liquid monomer resin to 3D print tinted Fresnel lenses having the potential in selective color filtering, focusing and sensing applications. The focusing ability of the printed lenses was characterized by using customized optical setups with the help of relative power intensity and transmission spectra measurements. Surface wettability was analyzed using contact angle measurement that revealed the hydrophilic nature of lens material. 3D printed Fresnel lenses are promising optical elements, offering custom-built optical designs, tailored tinted materials and they have the potential to be integrated with both active and passive optical sensors for sensing applications.

Relative Intensity Measurements of Libs Emission Spectra of Alkali Halides and their Application to Elemental Analysis of Mineralogical Samples

Relative Intensity Measurements of Libs Emission Spectra of Alkali Halides and their Application to Elemental Analysis of Mineralogical Samples

Hitz-bukaerako herskariak: kontsonante talkak

Euskaraz hitz-bukaerako herskariek oso maiztasun txikia dute hiztegian, baina oso maiztasun handia solasean; /-t/ eta /-k/ kontsonanteak maiztasun handiko atzizki batzuetan aurkitzen baitira. Lan honetan hitz-bukaerako herskarien gauzatze fonetikoa aztertzen dugu, eta bereziki bi hitzen arteko kontsonante taldeetan jartzen dugu arreta. Datuak elkarrizketa libretik atera ditugu. Intentsitate neurketak erakusten du talde horietan kontsonanteak oso ahulak direla gehienetan. Espektrogramak miatuz baieztatzen dugu /-k/ eta /-t/ kontsonanteak beste kontsonante baten aurrean gehiengoetan galtzen edo hurbilkari ahostun gisa ahoskatzen direla. Bestalde, ahoskabetze gertakariak (adib. /k#b/ --> [p]) ez dira batere normalak gure corpusean.

Differences in Therapeutic Efficacy in Pancreatic Cancer Between Interstitial and Superficial Light Delivery Strategies in Targeted Photo Therapy

The purpose of this study was to determine if therapeutic efficacy of a Cetuximab based near-infrared (NIR) targeted photo therapy (TPT) was dependent on light delivery strategies. We examined the cytotoxic effects of TPT in a pancreatic cancer mouse model, when administered to tumors interstitially and superficially. A subcutaneous mouse model of pancreatic cancer using BXPC-3 - GFP cells was established in male athymic (nu/nu) mice. The mice received intravenous (IV) injection of Cetuximab-IR700DX, 24 hours prior to near-infrared light irradiation. Interstitial illumination was administered at a 400mW/cm fixed power output, at a light dose of 100 J/cm to half the mice and at 300 J/cm to the remaining mice. Superficial illumination was administered at a 150mw/cm2 fixed power density at a dose of 50 J/cm2 to half the mice, and at 250 J/cm2 to the other half. Cellular damage and decrease in cell viability was determined by the decrease in GFP fluorescence intensity levels in whole animal images and in relative intensity measurements. Interstitially administered TPT resulted in greater long-term permanent damage (72 hours post treatment) to tumor cells (0% recovery at low dose, and 11% recovery at high dose) compared to superficially administered TPT (1% recovery at low dose, and 44% recovery at high dose). While these results demonstrated that near-infrared targeted photo therapy efficacy was dependent on the type of light delivery strategy, overall, both superficial and interstitial Cet-IR700DX based near-infrared targeted photo therapy can effect significant long-term damage (less signal recovery) to pancreatic cancer cells in vivo at lower doses regimens, compared to higher dose regimens (higher signal recovery).

Forecasting the labor intensity and labor income share for G7 countries in the digital age

The development of digital technology has raised concerns about a decline in labor activity. In this paper, we offer predictions of the possible dynamics of the share of labor income for G7 countries, based on an assessment of the parameters of the factor-augmenting CES function. Particular attention is paid not only to the parameter of elasticity of substitution, but also to the measurement of relative labor intensity, which is ignored in most similar works. We show that a decrease in the share of labor income under a substitution elasticity of less than one occurs due to a trend towards an increase in relative labor intensity while reducing the ratio of investment to output. This pattern is a theoretical anomaly and can be reasonably explained by the growth of monopoly power under the development of the digital economy. Continuation of this trend in the next 30 years may lead to a decrease in the share of labor income in the G7 countries by an average of 5–16%.

An Analysis of the $B^{3}\Pi _{2} - X^{3}\Delta _{2}$ (0, 0) Band System of the TiO Molecule in Laboratory and Sunspot Spectra

The $B^{3}\Pi _{2} - X^{3}\Delta _{2}$ (0, 0) band system of the titanium monoxide (TiO) molecule was excited in a DC copper arc with a constant deviation spectrometer. The resulting spectrum has been analyzed using image J software. Relative intensity measurements of the P- and R-branch molecular lines of the (0, 0) band with rotational quantum ( $J$ ) numbering have been obtained. The measured intensity of rotational molecular lines and the $J$ numbering were used to estimate the excitation rotational temperature of the source emitting the spectrum of TiO molecules. Also the presence of TiO spectral lines of the $B^{3}\Pi _{2} - X^{3}\Delta _{2}$ (0, 0) band in the wavenumber region of 14 500 to 16 000 cm−1 has been confirmed in the umbral spectrum, from the atlases recorded at the National Solar Observatory using the Fourier transform spectrometer (FTS) of the McMath-Pierce Solar Telescope on Kitt Peak. The combined laboratory and sunspot spectral line measurements have been used to obtain the improved molecular structure parameters for the electronic states $B^{3}\Pi _{2}$ and $X^{3}\Delta _{2}$ of the TiO molecule. Using equivalent width measurements of well resolved and identified lines in the sunspot spectrum with known rotational quantum number, the effective rotational temperature was found to be $2555 \pm 780$ K. This proves the presence of TiO molecules in sunspot and other higher temperature astrophysical sources.

Modeling and measurement of relative intensity of acoustic arrivals within the beaufort duct

The Beaufort Duct, located at approximately 175 m depth in the Canada Basin, allows for long-range acoustic propagation from sources moored within the duct. As part of the Canada Basin Acoustic Propagation/Glider Experiment (CANAPE/CABAGE), LFM sweeps with frequencies around 250 Hz were transmitted by broadband moored sources and received by two Seagliders traversing between them. In addition to receiving acoustic data, these Seagliders measured temperature, pressure, and salinity, providing measurements of the sound speed profile throughout the CANAPE study region. These profiles were used as inputs for broadband acoustic parabolic equation predictions. Measured data receptions within the duct show intense peak arrivals prior to the final cutoff that are higher in relative intensity than predicted. The duct properties of the measured sound speed profiles are parameterized and acoustic predictions using actual profiles as well as idealized profiles are used to study the predictability of these intense peaks within the duct.

Acute Exercise Increases Pain Threshold And Subjective Psychoactive Mood State

Prescription pain medication can be addictive and have long-term health consequences. Alternative pain-relieving strategies are becoming increasingly sought after. Exercise is known to have a pain-relieving effect which is thought to be mediated through the dopaminergic system. PURPOSE: To examine the relationships between minimum pain threshold (MPT), exercise blood lactate (EBL), and the self-reported psychoactive effects of exercise based on questions from the Morphine-Benzedrine Group, Morphine and Excitement subscales of the Addiction Research Center Inventory (ARCI) following acute exercise in college aged students. METHODS: Twelve college aged students (age = 20.9 ± 0.5yr) underwent 5 minutes of light leg cycling as a warmup. Following the warmup, they cycled for 20 minutes at 8 METS with an additional 5-minute cooldown. Measurements were taken prior to exercise and just before the cool down. EBL was collected as a measure of relative exercise intensity. The MPT was measured using a Wagner “Pain Test” algometer on the extensor carpi radialis. Results were assessed using a Student’s T-Test. RESULTS: Following exercise the MPT was increased by 62.1% ± 2.8 (P<0.001). Women had a greater increase in MPT (25.7 ± 9.1%) relative to men (15.8 ± 9.4%; P<0.05). EBL increased from an average of 1.8 ± 0.6 mmol/L at baseline to 4.1 ± 0.7 mmol/L following exercise (P<0.01). There was a positive linear correlation between MPT and EBL (r2=0.59; P<0.05). Indicating greater EBL levels were related to increased MPT. Positive responses from the ARCI subscale increased by 27 ± 3.3% following exercise (P<0.05). There was no effect of sex nor EBL on positive responses on the ARCI. CONCLUSIONS: These data suggest moderate intensity exercise can increase MPT and to a greater extent in women. Further, MPT correlated with increased EBL indicating that greater relative exercise intensity may modulate a greater increase MPT. Moderate intensity exercise increased positive responses on the ARCI providing evidence that the dopaminergic system may drive changes to MPT. However, positive responses did not correlate to EBL which may suggest another variable may augment pain reduction with increased exercise intensity.

REFLECTION OF LIGHT FROM THE DIFFRACTION GRATING WITH TRIANGULAR PROFILE

we study the light diffraction at a reflective grating with triangular profile in scalar wave optics approximation. The case of 1D diffusively reflective rough surface can be described in the first approximation as a random set of reflective gratings with triangular profiles, which are characterised by normal (Gaussian) distribution of amplitude and spatial period. We have obtained the condition for amplitude and period of a diffraction grating in the case of absence of secondary reflections, and the dependence of optical path difference on amplitude and spatial period of the triangular profile. We have investigated the influence of triangular profile parameters on the intensity of reflected wave. We have measured the relative intensity (reflection coefficients) of rough surface reference samples in the case of normal incidence. The relative intensity of reflected wave in the case of normal incidence is used in the design of optical contactless methods for the characterisation of rough surfaces in range of 0.05…0.25 mm. We suggested an optical scheme for the surface roughness measurements, and tested it on the reference samples of rough surfaces. We investigated the dependence of reflected wave intensity on the diffraction angle, and simulated it using numerical solutions of Maxwell equation (FDTD methods). Therefore, we demonstrate that measurements of relative intensity of the reflected wave in the normal to sample plane direction in an objective focal plane allow for determination of the roughness of diffusely reflective surfaces