Fv Values Research Articles

Correlation studies between physical properties and concentration of voids entrenched in V2O5 mixed lead bismuth silicate glass system by means of positron annihilation spectroscopy

In this investigation we have estimated the fraction of free volume defects and also their size (to the nanoscale) entrenched in V2O5 doped PbO added Bi2O3–SiO2 glass system (by means of positron annihilation spectroscopy (PAS) studies) with a view to understand the influence of such defects on several physical properties of this glass system. The glasses of the chemical composition viz., 30PbO–5Bi2O3‒ (65- x) SiO2:x V2O5 (0 ≤ x ≤ 0.6, insteps of 0.1) are used in this study. Glasses were prepared by traditional melt quenching technique. PAS studies were perormed using 22Na (0.1 MBq) positron radioactive source. Positron annihilation lifetime is found to be significantly affected by the concentrations of V2O5 dopant. The third component I3 of positrons is found to be feeble in all the glasses. For this reason, initially, we have used a simple two component positron trapping model (ignoring the third component) to calculate annihilation parameters viz., the bulk average positron lifetime (τb), positron trapping rate in defect (κd), fraction of trapped positrons (η), the average lifetime for all the positrons (τavg) and defect-related time (τd). The calculations were repeated with three component positron model. The results of positron annihilation studies have indicated that concentration of free volume nano sized defects, the fraction (fv) of volume defects and their radius (R) are the lowest for the glass V3. Such minimal value of defect concentration is ascribed to dominant existence of vanadium ions in V5+ valence state that involves in glass network forming with VO5 structural units. Whereas, the observed increased value of fv with increase of V2O5 from 0.3 to 0.6 mol% is attributed to growing concentration of vanadyl complexes (VO)2+ that have acted as modifiers. Quantitative information obtained on dependence of concentration of free volume imperfections on V2O5 content in the studied glass is observed to be in good agreement with the inferences drawn from several macroscopic properties that include electrical properties reported earlier.

Assessment of radionuclide transfer factors and transfer coefficients near phosphate industrial areas of South Tunisia.

The activity concentrations of naturally occurring and anthropogenic radionuclides in agriculture soils as well as in several food products at four locations within the phosphate area of South Tunisia were investigated. Soil-to-plant transfer factors as well as feed-to-animal products transfer coefficients were determined for the first time for the region. Activity concentrations of 40K, 210Pb, 226Ra, 228Ra and 137Cs in soils of agriculture fields were lower than worldwide average values. The soil-to-plant transfer factors (TFs) for 40K in leafy vegetables were higher than those in fruit vegetables. Soil-to-grass transfer factor (Fv) values were in the following order: 40K > 210Pb > 226Ra. The grass-to-milk transfer coefficient (Fm) values for 40K and 210Pb ranged between 2 × 10-3 and 4 × 10-3(day L-1). The concentration ratios for the animal products (CRmilk-feed, CRmeat-feed and CRegg-feed) varied in the ranges of 2 × 10-2-4 × 10-2 L kg-1, 1 × 10-2-2 × 10-1 (L kg-1)and 5 × 10-2-1 (L kg-1)for 40K, 210Pb and 226Ra, respectively. Transfer parameters determined in the present study were compared with those reported in International Atomic Energy Agency reports and other published values. The absorbed gamma dose rate in air and the external hazard index associated with these natural radionuclides were computed to assess the radiation hazard of radioactivity in this region, and the results indicated that these areas are within set safety limits.

Design principles based on analysis in [formula omitted] space to achieve near-perfect full-spectrum volumetric solar-thermal conversion

Although achieving efficient solar-thermal conversion with nanofluids (NFs) plays an important role in developing photothermal technologies, full-spectrum energy usage is still challenging currently. In this work, dimensionless methods of designing NFs are proposed in complex permittivity (ε) space, to make the most of solar energy. Firstly, an effective regime Ω′ for each size parameter x is determined, in which an ideal photothermal efficiency can be guaranteed if only the NPs’ permittivity falls into this area. Besides, on the other hand, by introducing a dimensionless parameter Qi, our methods also allow to actively chose properties of NFs with a desirable solar-to-thermal efficiency, including volume concentration of NPs (fv) and thickness of NFs (L). Based on the proposed principles, results show that SiO2@Ni and SiO2@TiN NFs perform better with efficiency 15–30% improved than other widely used materials, such as SiO2@Ag(Au, Al) counterparts. Further, genetic algorithms are employed to verify the above results. Consistently, it suggests that near-perfect full-spectrum photothermal efficiency of SiO2@Ni or SiO2@TiN NFs can be obtained, reaching to 99% under certain conditions. In addition, regarding these two superior NFs, appreciable performance can also be protected with considerably small values of fv and L, which helps to reduce costs and is attractive in practice. The proposed principles offer a powerful tool to actively design optimized NP-related NFs for achieving perfect photothermal conversion, which will also potentially stimulate the development of other advanced photothermal technologies.

Oxygen barrier, free volume and miscibility properties of fully bio-based polyamide 1010/poly(vinyl alcohol) blends

Fully bio-based polyamide 1010 (PA1010) was successfully melt-blended with poly (vinyl alcohol) (PVA03, PVA05, PVA08 and PVA14) to prepare PA1010xPVAzy blends. The PA1010xPVA03y, PA1010xPVA05y, PA1010xPVA08y and PA1010xPVA14y films demonstrated the lowest oxygen transmission rates (OTR), free volume fraction (Fv), mean volume of the free volume holes (Vf) and mean number of free volume holes per unit volume (I3) values, when the PVA concentration in each PA1010xPVAzy series reached a corresponding critical value of 22.5, 20, 17.5 and 12.5 wt%, respectively. OTR, Fv, Vf and I3 values obtained for the best PA101087.5PVA1412.5, PA101082.5PVA0817.5, PA101080PVA0520 and PA101077.5PVA032.25 films reduced gradually as the degree of polymerization of PVA reduced. The results of dynamical mechanical and other experimental characterizations demonstrated that PA1010 and PVA are compatible to some extent, when the PVA are ≤ the corresponding critical concentration. The significantly enhanced oxygen permeation resistance and free volume characteristics for optimal PA1010xPVAzy films is at least partly due to the improved hydrogen-bonded molecular interactions between PA1010 C=O groups and PVA O-H groups.

Deterioration of Brain Neural Tracts in Elderly Women with Sarcopenia

Sarcopenia is known to be associated with increased stiffness in brain arteries, which causes deterioration in brain structure and function. In this study, the authors evaluated the deterioration of neural tracts using diffusion tensor tractography (DTT) in elderly women with sarcopenia and investigated whether deterioration of neural tracts is consistent with clinical findings. Twenty elderly women with sarcopenia were recruited. Muscle mass was measured by dual energy x-ray absorptiometry. Hand-grip power and gait speed were also assessed. Memory function was evaluated using the Seoul Neuropsychological Screening Battery. Additionally, using DTT-Studio software, the authors evaluated eight neural tracts: the corticospinal tract (CST), corticoreticular pathway, fornix, cingulum, superior longitudinal fasciculus, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, and optic radiation. The authors measured the DTT parameters (fractional anisotropy [FA] and fiber volume [FV]) for each neural tract. The FA and FV values were decreased in all the evaluated neural tracts, compared with those of the 20 normal comparison subjects. The FVs of the CST were significantly correlated with the hand-grip power of elderly women with sarcopenia. The FVs of the fornix and cingulum in elderly women with sarcopenia were significantly correlated with their memory function. The authors found that the neural tracts in elderly women with sarcopenia were extensively deteriorated, and their hand-grip power and memory function were associated with related neural tracts. The DTT seems to be a useful tool for evaluating structural changes in the brains of people with sarcopenia.

PREDICTORS OF LONG-TERM ADVERSE PROGNOSIS IN PATIENTS WITH ACUTE CORONARY SYNDROME WITH ST-SEGMENT ELEVATION

Aim: Identification of predictors of unfavorable annual prognosis in patients with acute coronary syndrome with ST-segment elevation (STEMI). Material and methods: The study included 69 patients with STEMI who were hospitalized in the period from March 2014 to January 2017 in the hospital named after Zhadkevich. The follow-up period was 12±3 months after the index STEMI Longterm prognosis was established in 62 (89.8%) patients. Results: the fatal outcome was observed in 7 (11.3%) patients. Nonfatal myocardial infarction developed in 10 (16.2%), hospitalization with heart failure decompensation - in 5 (8%), nonfatal acute cerebrovascular accident - in 3 (4.8%) patients. Predictors of adverse prognosis were: age >60 years, level of brain natriuretic peptide (BNP) >29.2 pmol/l, C-reactive protein (CRP) >4.7 mg/l, left ventricular ejection fraction (LVF) 60 years and BNP level >29.2 pmol/l. Conclusion: Adverse factors affecting the long-term outcome of the disease (12±3 months after the STEMI) are: BNP level >29.2 pmol/l, CRP level >4.7 mg/l, LV FV value 60 years.

A study on sensitivity of seismic site amplification factors to site conditions for bridges

Seismic site amplification factors and seismic design spectra for bridges are influenced by site conditions that include geotechnical properties of soil strata as well as the geological setting. All modern seismic design codes recognize this fact and assign design spectral shapes based on site conditions or specify a 2-parameter model with site amplification factors as a function of site class, seismic intensity and vibration period (short and long). Design codes made a number of assumptions related to the site conditions while specifying the values of short (Fa) and long period (Fv) site amplification factors. Making these assumptions was necessary due to vast variation in site properties and limited availability of actual strong motion records on all site conditions and seismic setting in a region. This paper conducted a sensitivity analysis for site amplification factors for site classes C and D in the AASHTO bridge design code by performing a 1-D site response analysis in which values of site parameters like strata depth, travel-time averaged shear wave velocity in the top 30 m strata (Vs30), plasticity index (PI), impedance contrast ratio (ICR) and intensity of seismic ground motion were varied. The results were analyzed to identify the site parameters that impacted Fa and Fv values for site classes C and D. The computed Fa and Fv values were compared with the corresponding values in the AASHTO bridge design code and it was found that the code-based Fa and Fv values were generally underestimated and overestimated respectively.

Reply to Discussion of “Effect of Site Conditions on Site Amplification Factors and Seismic Design Spectra for Bridges” by Alireza Eskandarinejad

Site amplification factors and seismic design spectra for bridges are affected by site conditions. Influence of the following parameters on site amplification factors, Fa and Fv, is investigated herein: (1) confining pressure used in Modulus and Reduction Damping (MRD) curves, (2) shear wave velocity (Vs) of seismic input motions and (3) necessity of using nonlinear site response analysis. It was concluded that the mentioned parameters had an insignificant impact on Fa and Fv values in majority of the analysis cases and had a low to moderate impact for a small number of analysis cases in few site classes only when subjected to a limited set of ground motions.

Properties of polyamide 612/poly(vinyl alcohol) blends and their impact on free volume and oxygen barrier properties

Oxygen transmission rates and free volume properties (i.e. average volumes of free-volume-cavities (Vf), mean number of the free volume cavities per unit volume (I3) and fractional free volume (Fv)) values of bio-based polyamide 612 (PA612)/poly(vinyl alcohol) (PVA) (i.e. PA612xPVA03y, PA612xPVA05y, PA612xPVA08y and PA612xPVA14y) blend films were reduced to a minimum value, when their PVA content reached corresponding optimal values of 25, 20, 15 and 10 wt%, respectively. The minimum oxygen transmission rate, Vf, I3 and Fv value obtained for the best PA61290PVA1410, PA61285PVA0815, PA61280PVA0520 and PA61275PVA0325 bio-based blown films reduced considerably with decreasing PVA degrees of polymerization. As evidenced by the results of dynamical mechanical analysis, differential scanning calorimetry, wide angle X-ray diffraction and Fourier transform infrared spectroscopic experiments, PA612 and PVA are miscible to some extent at the molecular level when their PVA contents are ≤ the corresponding optimal values. The significantly improved oxygen barrier and free volume properties for the PA612xPVAzy blend films with optimized compositions is at least in part to the enhanced intermolecular interactions between PA612 carbonyl groups and PVA hydroxyl groups.

Oxygen barrier, free volume, and blending properties of polyamide 12/poly (vinyl alcohol) blends

Oxygen permeation rates, average volumes of free‐volume‐cavities (Vf), and fractional free volumes (Fv) of polyamide 12 (PA12)/poly(vinyl alcohol) (PVA) (ie, PA12xPVA05y, PA12xPVA08y, and PA12xPVA14y) blend films with varying PVA degrees of polymerization reduced to a minimum value when their PVA contents reached a corresponding optimal value, respectively. The minimum oxygen permeation rates, Vf, and Fv values obtained for the optimal PA12xPVAzy blown films were reduced considerably with decreasing PVA degrees of polymerization. Experimental findings from dynamic mechanical analysis, differential scanning calorimetry, wide angle X‐ray diffraction, and Fourier transform infrared spectroscopy of the PA12xPVAzy blend series suggest that PA12 and PVA in PA12xPVAzy are miscible to some extent at the molecular level when their PVA contents are near and less than the corresponding critical values. The considerably enhanced oxygen barrier properties of the PA12xPVAzy blend films with optimized compositions are attributed to the significantly reduced local free volume characteristics.

Properties of polyamide 6,10/poly(vinyl alcohol) blends and impact on oxygen barrier performance

AbstractThe oxygen transmission rate, average volume of free‐volume cavities (Vf) and fractional free volume (Fv) of polyamide 6,10 (PA610)/poly(vinyl alcohol) (PVA) (i.e. PA610xPVA05y, PA610xPVA08y and PA610xPVA14y) blend films reduced to minimum values when their PVA contents reached corresponding optimal values. Oxygen transmission rate, Vf and Fv values obtained for optimal PA610xPVAzy blown films were reduced considerably with decreasing PVA degrees of polymerization. The oxygen transmission rate of the optimal bio‐based PA61080PVA0520 blown film was only 2.4 cm3 (m2·day·atm)−1, which is about the same as that of the most often used high‐barrier polymer, ethylene–vinyl alcohol copolymer. Experimental findings from dynamic mechanical analysis, differential scanning calorimetry, wide‐angle X‐ray diffraction and Fourier transform infrared spectroscopy of the PA610xPVAzy blends indicate that PA610 and PVA in the blends are miscible to some extent at the molecular level when the PVA contents are less than or equal to the corresponding optimal values. The considerably enhanced oxygen barrier properties of the PA610xPVAzy blend films with optimized compositions are attributed to the significantly reduced local free‐volume characteristics. © 2017 Society of Chemical Industry

Dependence of Nanostructure and the Optical Properties of Ni Thin Films with Different Thicknesses on the Substrate Temperature

Nickel films with the thicknesses of 30 and 120 nm were deposited on glass substrates, at different substrate temperatures (313 to 600 K) under uhv condition. The nano-structure of the films and mean diameter of grains was obtained for each films using atomic force microscopy (AFM). Their optical properties were measured by spectrophotometry in the spectral range of 190-2500 nm. Kramers-Kronig method was used for the analysis of the reflectivity curves. The Effective Medium Approximation (EMA) analysis was used to determine the values of volume fraction of voids (fv)and establish the relationship between the nanostructure of the film and EMA predictions. Qualitatively good agreements between structure Zone Model (SZM) as a function of substrate temperature and the values of (fv), is achieved. There is good agreement between these values and the results of mean diameter of grains for Ni films too. The absorption peaks of Ni thin films at ~ 1.4 eV and 5 eV are observed, with an additional bump at about 2 eV. The 1.4 eV peak is in particular much stronger than that obtained in earlier works on Ni thin films (Johnson and Christy (1974)) and on bulk Ni sample (Lynch et al (1971) and Ehrenrich et al (1963)). This is resulted from producing thin films under uhv condition. The conductivities σ1 and σ2 calculated from ɛ1 and ɛ2 for Ni films and were plotted vs energy.

Simultaneous measurements of gas temperature, soot volume fraction and primary particle diameter in a sooting lifted turbulent ethylene/air non-premixed flame

Simultaneous, planar measurements of flame temperature (T), soot volume fraction (fv), primary particle diameter (dp) and the derived number density of primary particles (Np) are reported in a well characterized, lifted ethylene jet diffusion flame, both to increase confidence in measurement accuracy and to provide new joint statistics. Planar measurements of temperature were performed using non-linear excitation regime two-line atomic fluorescence (nTLAF) of indium with an improved optical arrangement over those reported previously, and were found to yield good agreement with previous measurements obtained with coherent anti-Stokes Raman spectroscopy (CARS). Planar measurements of soot volume fraction and primary particle diameter were performed using time-resolved laser-induced incandescence (TiRe-LII). On the flame centreline, both the measured values of dp and fv grow with axial distance to peak near to the mid height of the flame. The joint probability density functions (PDF) of the measured T, fv, dp and derived Np were obtained from the two-dimensional images and assessed at 15 locations in the flame (5radial×3axial locations). Strong correlations were found between fv, dp and Np, while they exhibit a moderate correlation with flame temperature. The changes in PDFs with radial and axial locations and the most probable values are also reported.

The use of the rapid visco analyser (RVA) to sequentially study starch properties in commercial malting barley (Hordeum vulgare)

The aim of this study was to evaluate the use of the rapid visco analyser (RVA) instrument as a tool to sequentially analyse barley (Hordeum vulgare) malting varieties in order to visualise and interpret the effect of amylose and amylose complexes on its pasting properties. The RVA sequential profiles derived from the barley samples analysed showed a large peak (peak viscosity, PV) at the start of each cycle alternating with viscosity troughs during the hot paste viscosity cycle. The sequential cycles caused a slight decrease in both PV and (final) FV values in all barley varieties analysed. The addition of silver nitrate to the barley flour samples tends to slightly increase the PV value independently of the time of the analysis. The development of this methodology will provide with better tools to study starch pasting properties as well as to study the interactions between amylose and amylopectin with other compounds in various malting varieties.

Venous flow volume measured by duplex ultrasound can be used as an indicator of impaired tissue perfusion in patients with peripheral arterial disease

Aim: In this study, we aimed to investigate the arterial and venous flow volume rate (FV) in order to determine the tissue perfusion using duplex ultrasonography (DU). We hypothesized that FV provides reliable information regarding tissue perfusion in patients with peripheral arterial disease (PAD). Material and methods: The study comprised 38 patients (72 legs) with PAD. In all patients, common femoral, popliteal, anterior tibial, posterior tibial arteries and veins were examined with DU. Measurements were obtained in the supine position with 15 cm elevation of the foot to neutralise central venous pressure. The diameter, blood flow velocity, and FV of arteries and veins were measured for each patient. Results: The FV of the common femoral artery and vein (p = 0.001), popliteal artery and vein (p=0.003), and posterior tibial artery and vein (p = 0.008) had statistically significant differences. However, there was no statistically significant difference between the FV of the anterior tibial vein and artery (p = 0.408). The mean FV values of all veins were significantly lower than those of homonymous arteries in patients with PAD. Conclusions: Our study showed that venous FV measured by DU can be used as an indicator of impaired tissue perfusion in patients with PAD.

Venous flow volume measured by duplex ultrasound can be used as an indicator of impaired tissue perfusion in patients with peripheral arterial disease.

In this study, we aimed to investigate the arterial and venous flow volume rate (FV) in order to determine the tissue perfusion using duplex ultrasonography (DU). We hypothesized that FV provides reliable information regarding tissue perfusion in patients with peripheral arterial disease (PAD). The study comprised 38 patients (72 legs) with PAD. In all patients, common femoral, popliteal, anterior tibial, posterior tibial arteries and veins were examined with DU. Measurements were obtained in the supine position with 15 cm elevation of the foot to neutralise central venous pressure. The diameter, blood flow velocity, and FV of arteries and veins were measured for each patient. The FV of the common femoral artery and vein (p = 0.001), popliteal artery and vein (p=0.003), and posterior tibial artery and vein (p = 0.008) had statistically significant differences. However, there was no statistically significant difference between the FV of the anterior tibial vein and artery (p = 0.408). The mean FV values of all veins were significantly lower than those of homonymous arteries in patients with PAD. Our study showed that venous FV measured by DU can be used as an indicator of impaired tissue perfusion in patients with PAD.

Respostas fisiológicas da mandioca à aplicação de herbicidas

Analysis of chlorophyll a fluorescence has been used to improve the understanding of the mechanisms of photosynthesis, as well as in the evaluation of plant photosynthetic capacity altered by biotic or abiotic stresses. The objective of this study was to evaluate the sensitivity of cassava plants to herbicides with different mechanisms of action, as well as the damage caused by the application of herbicides on the photosynthetic apparatus of these plants. An experiment was conducted in a randomized block design with four replications. The treatments were constituted of the application of the following post- emergence herbicides in cassava: bentazon, clomazone, fomesafen, fluazifop-p-buthyl, glyphosate, nicosulfuron, chlorimuron, fluazifop-p-buthyl + fomesafen, sulfentrazone, besides a control without application. The visual intoxication and chlorophyll a fluorescence assessments were performed at 2, 9, 16 and 23 days after herbicide application. The herbicides evaluated affected differently the cassava plants. Sulfentrazone and glyphosate promoted plant death. Herbicides clomazone, fomesafen, fluazifop-p-buthyl and chlorimuron-ehtyl caused low toxicity to cassava plants and did not affect the ratio Fv / Fm and ETR. However, for the mixture nicossulfuron and fluazifop-p-buthyl + fomesafen values of Fv / Fm were suboptimal in the first evaluation times but plants treated with these herbicides had recovered. Physiological evaluations can be used as a way to evaluate the selectivity of herbicides in cassava crop as presented similar answers to those observed for visual intoxication symptoms.

Soot formation in diffusion oxygen-enhanced biodiesel flames

The focus of this work is the experimental investigation of soot formation in coflow flames formed of two fatty acid methyl esters (FAMEs) by employing the light extinction/scattering technique. Three different sets of experiments were conducted in this study. In the first set, radial soot volume fraction (fv) profiles of flames of vaporized neat canola methyl ester (B100CME) and neat soy methyl ester (B100SME) fuels both using air as the oxidizer were obtained. In the second set of experiments, the effect of oxygen content in the oxidizer stream on soot formation was studied in both FAME formed flames by increasing the oxygen content in the oxidizer stream from 21% to 35%, 50% and 80%. In the third set of experiments, the effect of fuel blending on the formation of soot particulates was studied in flames formed using CME blended with No. 2 diesel. The blends consisted of 80% biodiesel/20% diesel (B80) and 50% biodiesel/50% diesel (B50). The flames were scanned in the radial direction at various heights above the burner (HAB). For the B100CME-air flame the measured soot volume fraction fv peak was 4.04 ppm and was located at the symmetry axis at a HAB of 16.25 mm. For B100SME-air, the fv peak was measured to be 4.22 ppm at approximately the same flame height as in the CME-air flame. For the B100CME oxygen enriched-air flames the peak values at 35%, 50% and 80% were 6.50, 5.82 and 3.22 ppm, respectively. It was observed that by increasing the oxygen content in the B100CME flame from 21% to 35% oxygen, the fv peak increases by approximately 61%. However, a further increase in oxygen content in the oxidizer stream suppressed soot formation. A similar trend in the fv was observed for B100SME oxygen-enhanced flames. Furthermore, the increase of diesel fuel in the blending of B50CME resulted in significantly higher fv values compared to the B80CME. The addition of oxygen content in the oxidizer stream in these blended fuel flames (from air to 35%) resulted in an increase in the fv peak of approximately 47% and 71%, respectively. Centerline temperatures were measured at various HAB for selected flames.

Mathematical computation of water quality index of Vea dam in upper east Region of Ghana

The effect of sulfite on barley seedlings was investigated through Chl content, the electron transport activity of the photosystem, and Chl fluorescence. Barley leaves were harvested every 12 hrs during greening periods, and were then treated with a sulfite solution in either light or dark conditions. In both cases, the Chl content decreased in comparison with the control at any greening period. After sulfite treatment in the light, the activity of PS Ⅰ decreased slightly. yet that of PS Ⅱ showed a decrease of about 15%. The values of Fv, qP and qE decreased. however the value of qI increased compared with the control. In addition, the value of qE decreased in leaves greened more than 12 hrs compared with that of the control. This indicates that the photosynthetic complex involved in energy dependent fluorescence quenching is undeveloped in a 12 hrs greened leaf, accordingly, it was a hardly affected by sulfite. After sulfite treatment in the dark, the activities of PS Ⅱ and PS Ⅰ decreased slightly. there was a small change in the value of Fv, qP decreased, and qE and the ratio of qNP/q increased in comparison with the control. As a result, PS Ⅱ and PS Ⅰ were not inhibited, however, the redox of Q_(A) was inhibited, and the excited energy was lost through the nonphotochemical pathway. The effects of sulfite in light or dark conditions were not remarkably different according to the PS Ⅰ and Ⅱ activity measurement method yet were considerably different with the Chl fluorescence quenching analysis method. In both light and dark conditions, the value of qP significantly decreased with sulfite compared to that of the control. This implies that the redox of Q_(A) was inhibited by sulfite in both light and dark conditions.

Toward a multifunctional monolithic device based on pyroelectricity and the electrocaloric effect of thin antiferroelectric HfxZr1−xO2 films

Antiferroelectric HfxZr1−xO2 (HZO, x=0.1–0.3) films are reported herein as new Si-compatible materials for monolithic devices for pyroelectric energy harvesting, electrocaloric cooling, electrostatic energy storage, and infrared sensing. Hf0.2Zr0.8O2 and Hf0.3Zr0.7O2 films could work as pyroelectric energy harvesters using the Olsen cycle with the harvested energy densities of 11.5 and 5.7Jcm−3cycle−1, which are ~7.6 and ~3.7 times larger than the largest value ever reported. The electrocaloric effect (ECE) of HZO films was also firstly examined, and the maximum ΔT values of the Hf0.2Zr0.8O2 and Hf0.3Zr0.7O2 films were 13.4 (at 307K) and 9.8K (at 448K), respectively. The wide temperature range for the large ECE of the HZO films was highly promising for the actual cooling cycle with large reversible work values. Moreover, the large capacitance of the HZO films due to the field-induced phase transition between the poled and anti-poled states can be used for electrostatic energy storage and high-charge capacitors. The k2 and Fv values, which are the figures of merit for conventional pyroelectric energy conversion and infrared detection for thermal imaging, of the Hf0.2Zr0.8O2 film were 24.4×10−3 and 32.0×10−2m2C−1, respectively, which prove that Hf0.2Zr0.8O2 is also a promising material for these applications.