Integral Intensity Research Articles

Quantitative models and potential surrogates for rapid evaluation and surveillance of chlorine disinfection efficacy in reclaimed water

Chlorine disinfection has become the most widely applied and indispensable technology in wastewater treatment and reuse to mitigate microbial risk and guarantee water safety. However, owing to complexities and high concentrations of contaminants in reclaimed water, rapid evaluation of chlorine disinfection efficacy is a crucial but challenging issue. Based on intensive experimental and statistical analyses, this study has established kinetic models and potential surrogates for rapid indication of the inactivation of microbial indicators and opportunistic pathogens during chlorine disinfection in different reclaimed waters. Overall, the constructed Selleck models performed very well to simulate log removal values (LRVs) of fecal coliforms, Pseudomonas aeruginosa and heterotrophic plate counts in all reclaimed water samples (R2 = 0.877–0.990). Moreover, total and Peak A fluorescence intensity as well as fluorescence integral intensities in Regions II and IV were found to have high response sensitivities during the chlorination process. Nevertheless, their effectiveness to act as potential surrogates of LRVs of microbial indicators needs to be further validated. The results from this study can provide valuable information on microbial safety surveillance of disinfection toward sustainable and long-term water reuse.

Eu2+ and Mn2+ co-doped Lu2Mg2Al2Si2O12 phosphors for high sensitivity and multi-mode optical pressure sensing

The Eu2+ and Mn2+ co-doped Lu2Mg2Al2Si2O12 phosphor has two independent high sensitivities, 1.77 and 3.53 nm GPa−1. The decay degree of the overall integral intensity and the fluorescence intensity ratio (FIR) were put forward for pressure sensing.

Understanding the broadband near-infrared luminescence in a highly distorted garnet Ca4HfGe3O12:Cr3+ phosphor.

Broadband near-infrared (NIR) spectroscopy generated from a phosphor-converted light-emitting diode (pc-LED) has multifunctional applications, including food-quality analysis, bio-medical and night-vision, stimulating the demand for developing various NIR phosphors with desired properties. Herein, we selected a highly distorted garnet Ca4HfGe3O12 as the host and explored the near-infrared luminescence of Cr3+. As expected, this material achieved a long-wavelength NIR emission and excellent absorption efficiency based on the effect of Jahn-Teller distortion. The synthesized Ca4HfGe3O12:Cr3+ phosphor exhibits a broadband NIR emission peaking at 840 nm with a full width at half maximum of 150 nm, and the absorption efficiency reaches 48.0%. However, the internal quantum efficiency of the 6 mol% Cr3+-doped sample was measured to be only 35.3% and the integral emission intensity at 373 K kept only 60.1% of the initial intensity. The possible reasons for the unsatisfactory internal quantum efficiency and thermal stability were systematically analyzed, which provided a comprehensive understanding of the relationship between the crystal structure and the luminescent properties of Cr3+-activated garnet-type phosphors. Nevertheless, the as-prepared NIR pc-LED device exhibits a NIR output of 16.52 mW with a NIR photoelectric conversion efficiency of 5.92% driven by 100 mA current, indicating the potential of this material for application in NIR pc-LED.

Large Eddy Simulation Study on the Turbulence and Flame Characteristics under Analogical Integral Scale and Turbulence Intensity of Turbulent Premixed Flames

Large Eddy Simulation Study on the Turbulence and Flame Characteristics under Analogical Integral Scale and Turbulence Intensity of Turbulent Premixed Flames

Interaction of Isonicotinic Acid Hydrazide with Carboxylic Acid Anhydrides

There has been presented data on the synthesis of monoamides and cyclic imides which are derivatives of isonicotinic acid hydrazide. Cyclic anhydrides of carboxylic acids (succinic, maleic and phthalic) easily react with the hydrazide of isonicotinic acid with cycle opening, forming isonicotinoylhydrazide of dicarboxylic acids, and under more severe conditions the latter are transformed into cyclic acid imides. The structures of the synthesized compounds were studied using 1H- and 13C-NMR spectroscopy, as well as data from twodimensional COSY (1H-1H) and HMQC (1H-13C) spectra. The values of chemical shifts, multiplicity and integral intensity of 1H and 13C signals in one-dimensional NMR spectra were determined. Homo- and heteronuclear interactions confirming the structure of the studied compounds were established using spectra in the COSY (1H-1H) and HMQC (1H-13C) formats. In the approximation of the density functional B3LYP with a base set of 6-31G(d), the enthalpy of the reactions ΔHr in the absence and in the presence of a solvent — isopropanol (self-consistent reaction field method) were calculated quantum-chemically

OBSERVATIONS OF DECAMETER CARBON RADIO RECOMBINATION LINES IN SEVERAL GALACTIC DIRECTIONS Part 2. ANALYSIS OF PHYSICAL CONDITIONS IN DIFFUSE CII REGIONS

Subject and Purpose. In Part 2 of the current paper, we seek to analyze the observational results of decameter carbon radio recombi- nation lines (RRLs) detected near the frequency 26 MHz through the UTR-2 radio telescope towards the S140 emission nebula and the GSH 139-03-69 super shell. These lines have proven themselves as a highly effective tool for cold, rarefied interstellar medium (ISM) diagnostics. The aim is to determine an association of line-forming regions (CII regions) with other ISM components and study physical conditions (electron temperature Te and electron density Ne) in these regions. Methods and Methodology. By iterative comparison of detected and modeled integral intensities of decameter carbon RRLs, we determine physical state ranges where recorded experimental data best fit the model values for various combinations of Te , Ne , and path lengths s. Results. It has been found that the characteristics of the detected decameter carbon RRLs are consistent with the higher-frequency data for both the S140 line of sight and other Galactic plane directions, including the GSH 139-03-69 direction. Ranges of physical con- ditions where recorded data and model values are in the best agreement have been determined, being Te 50 ÷ 100 K, Ne 0.01 cm–3, and s 10 pc — for the S140 nebula direction and its vicinity and, also, Te 50 ÷ 100 K, Ne 0.01 cm–3, and s 5 ÷ 7 pc — for the GSH 139-03-69 super shell direction. Conclusions. The obtained results indicate that the detected decameter carbon RRLs originate from CII regions associated with clouds of diffuse neutral hydrogen HI in the Galactic plane. The lines are seen against a background Galactic radio emission whose brightness temperature increases as frequency decreases.

Highly efficient near-infrared solid solution phosphors with excellent thermal stability and tunable spectra for pc-LED light sources toward NIR spectroscopy applications.

Near-infrared (NIR) luminescent materials have attracted wide research interest due to their unique photophysical properties for designing NIR light-emitting diodes (NIR LEDs). Here, a series of Cr3+-activated NIR-emitting solid solution phosphors, Gd1-xLux(Al1-xScx)3(BO3)4:0.01Cr3+ (GLASB:Cr3+) (x = 0 to 0.5), are successfully synthesized via a cosubstitution approach. The GLASB:Cr3+ phosphors reveal extraordinary optical performance with a desirable high IQE of 93.6%, considerable broadened FWHM (from 128 nm to 196 nm) and redshift of 119 nm (747 → 866 nm) as the amount of [Lu3+-Sc3+] ion doping increases. Moreover, their photoluminescent thermal stability is substantially improved, maintaining 105.7% of the initial integral intensity up to 150 °C, namely zero-thermal-quenching. The NIR pc-LED fabricated using the GLASB:Cr3+ phosphor generates an NIR output power of 46 mW and an electro-optical efficiency of 37% at a 120 mA input current. Finally, the characteristic NIR emission of this phosphor can not only be utilized in the fields of night-vision technology and biometric identification, but also exhibits a perfect match with the absorption of the bacteriochlorophyll (BChl) and light-harvesting protein (LHP) of photosynthetic bacteria (PSB), presenting a high application prospect for improving PSB photosynthesis.

Improving upconversion luminescence intensity of BiTa7O19:Er3+/Yb3+ by polyvalent Sb co-doping.

BiTa7O19:Er3+/Yb3+/Sb phosphors were successfully synthesized by high temperature solid sintering. X-ray diffraction (XRD), fluorescence spectrometry and X-ray photoelectron spectroscopy (XPS), were used to analyze the phase structure, upconversion luminescence (UCL) features and Sb valence state, respectively. The results suggest that polyvalent Sb with Sb3+ and Sb5+ can replace the Ta5+ sites in a BiTa7O19 host to form a pure phase. Compared with BiTa7O19:0.1Er3+/0.4Yb3+, polyvalent Sb doping further improves UCL intensity by 1.2 times under 980 nm laser stimulation with a powder density of 44.59 W cm-2. This is due to the adjustment of the local lattice structure of BiTa7O19 by the polyvalent Sb. The maximum absolute sensitivity (SA) and relative sensitivity (SR) can be estimated from the UCL variable-temperature spectra as 0.0098 K-1 at 356 K and 0.0078 K-1 at 303 K using the luminescence intensity ratio (LIR) approach. The outcomes show that host local lattice adjustment using polyvalent elements is an effective way to improve luminescence intensity, and it is possible to use BiTa7O19:Er3+/Yb3+/Sb as a temperature sensor.

MOLECULAR BINDING OF 2-PHENYLETHYLAMINE BY β-CYCLODEXTRIN

The paper considers the results of an experimental study of the synthesis of 2-phenylethylamine, a biogenic amine, which is the initial link in natural neurotransmitters and is used in pharmacological practice as an antidepressant and a remedy for the treatment of neurological disorders. The target amine was synthesized by reduction of phenylacetonitrile with lithium borohydride and decarboxylation of the sodium salt of phenylalanine. The reduction reaction proceeds in aqueous ethanol at room temperature, which increases the yield of the product. At the same time, the resulting product quickly passes in air into an insoluble carbonate. Decarboxylation occurs when the sodium salt of phenylalanine is fused with an alkali, which leads to the partial formation of a condensation product, 3,6-dibenzylpiperazine-2,5-dione, at a high temperature. It is shown that both methods lead to the synthesis of the product with yields of about 45%. The inclusion complex of phenylethylamine with β-cyclodextrin, acting as an encapsulator - a container for molecular binding, was obtained by the suspension method. Binding occurs in an aqueous suspension, followed by washing the amine with acetone. The structure of the obtained compounds was proved by the method of nuclear magnetic resonance spectroscopy on 1H nuclei, as well as by thin-layer chromatography. Comparison of the integral intensities of the signals of the protons of the cyclodextrin framework and protons of the amino group of phenylethylamine showed that the process is accompanied by a transition to the bound form of 65% amine at a ratio of cyclodextrin : amine 3:2. It can be expected that such binding can be used in pharmacological practice to increase the stability of the amine, its targeted transport in the body and prevent premature processes of its destruction under the action of the monoamine oxygenase enzyme.

СПЕКТРЫ КОМБИНАЦИОННОГО РАССЕЯНИЯ УГЛЕРОДНЫХ МАТЕРИАЛОВ, ИСПОЛЬЗУЕМЫХ В КАЧЕСТВЕ КАТОДОВ АВТОЭМИССИОННЫХ ИСТОЧНИКОВ ИЗЛУЧЕНИЯ

Structured carbon materials are widely used in engineering and scientific research, in particular as materials for the auto-emission cathode of cathodoluminescent lamps. We apply Raman spectroscopy to determine the effect on fine-grained graphite (MPG-6), pyrolytic graphite, and PAN fibers when used as cathodes. Raman scattering spectra of all three materials were recorded before and after in the spectral range from 1000 to 2000 cm–1. In addition to the main lines of G, D, and D’ of carbon materials, we found a line in the range of (1450–1460) cm–1 in the initial pyrolytic graphite, in pyrolytic graphite after use as a cathode, and in the MPG-6 sample after use as a cathode. We observed the greatest change in the relative integral intensity of line D in pyrolytic graphite and MPG-6. This intensity increased in pyrolytic graphite and decreased in MPG-6 after use as a cathode. It will be possible to use the relative integral intensity of line D to evaluate the operation of a cathodoluminescent lamp.

Определение остаточной водонасыщенности и ее распределения в горных породах по данным компьютерной томографии с использованием интегральных интенсивностей спектров поглощения рентгеновского излучения

This article describes the methodology and results of studies to assess the distribution of residual water saturation in real core samples using X-ray computed tomography. The algorithm for determining residual water saturationis based on the analysis of integral intensities of absorption spectra, which is also used in other methods of studying the chemical composition of a substance, for example, infrared spectroscopy, nuclear magnetic resonance.This technique has been tested on standard petrophysical samples of terrigenous and carbonate deposits, characterized by various filtration-capacitance properties and collector type. The developed technique made it possible to determine the distribution of residual water in core samples, which can serve as additional information for development engineers of oil and gas fields.

Development of an untraditional technique to control the structure of the output flow from a vortex chamber

A technique of using coherent vortex formations of the dead-end zone of the vortex chamber of the end type as a controlling factor influencing the structure and characteristics of the output flow has been developed. The kinematic parameters of the flow relative to chambers with elongated and extremely short dead-end parts in the range of Reynolds numbers according to the parameters of the nozzle Re=47080–86530 were investigated. The reaction of the flow structure in the output sections of the vortex chambers was determined experimentally using thermoanemometry. Profiles of time-averaged transversal and axial velocity projections, as well as corresponding values of the relative intensity of velocity pulsations, were obtained. It was found that at Re=86530, the elongation of the dead-end part of the chamber leads to a decrease in the initial cross-section of the transversal component by 15 % with an increase in the axial component by 19.7 %, and, at Re=47080, to a decrease in the transversal component by 21 % with an increase in the axial component by 8.5 %. This indicates the redistribution of kinetic energy from transversal to axial energy motion, which is confirmed by the analysis of the corresponding intensity profiles of the velocity pulsations in the output section of the chamber in the near-wall and near-axis zones of the flow. The integral intensity of the velocity pulsations along the initial cross-section of comparable chamber designs increases in a chamber with an elongated dead-end part with almost no additional energy losses. The obtained results form the basis of a rational method of controlling the macro- and microstructure of flows, which determines the efficiency of mass exchange and heat exchange processes in vortex chambers of the end type. Such designs are characteristic of vortex mixers, burners of industrial furnaces, furnace devices of hot water and steam boilers, and other technological and power equipment

Quasielastic Light Scattering in the Broadband Brillouin Spectra of Relaxor Ferroelectric PbMg1/3Nb2/3O3

In this paper, the behavior of quasielastic light scattering (QELS) in a PbMg1/3Nb2/3O3 (PMN) crystal under broadband Brillouin light scattering in a temperature range from 750 K to 80 K was studied. It was shown that QELS consists of two components: narrow (0.9 GHz to 11 GHz) and wide (80 GHz to 600 GHz). The dependencies of the intensity, I, of these components on the frequency, ν, are well described by the power law I ~ eνα, with different α, and are determined by the distribution of the relaxation times. The analysis of the Brillouin spectra showed that the behavior of the relaxation time of both the components of QELS with temperature change is well described by the Arrhenius law. Additionally, in the vicinity of the intermediate temperature T* ≈ 380 K, a critical relaxation time behavior for the narrow component of QELS was detected. In the vicinity of the same temperature, a maximum in the integral intensity of both the components of QELS was observed, which is adjacent to another maximum in the region of the Vogel-Fulcher temperature TVF ≈ 250 K corresponding to the transformation of the crystal to a nonergodic state.

UV Light Irradiation Effects in P-Doped Diamonds: Total Content Determination of Phosphorus Donors.

Upon the UV light irradiation of single-crystal diamonds doped with phosphorus, several effects have been observed. The integral intensity of phosphorus lines in FTIR absorption spectra under UV radiation was increased. A saturation effect depending on the power of the laser radiation was demonstrated. Narrowing of the phosphorus lines, as well as the redistribution of the intensities in their doublets caused by the Jahn-Teller distortion of the donor ground state, was observed. It was found that these effects are associated with the decompensation of the phosphorus donors. An easy, fast, sensitive, and nondestructive, fully optical method for the determination of the total phosphorus donor's concentration in semiconducting diamonds, as well as its compensation ratio, was proposed.

Label-free testing strategy to evaluate packed red blood cell quality before transfusion to leukemia patients

Patients worldwide require therapeutic transfusions of packed red blood cells (pRBCs), which is applied to the high-risk patients who need periodic transfusions due to leukemia, lymphoma, myeloma and other blood diseases or disorders. Contrary to the general hospital population where the transfusions are carried out mainly for healthy trauma patients, in case of high-risk patients the proper quality of pRBCs is crucial. This leads to an increased demand for efficient technology providing information on the pRBCs alterations deteriorating their quality. Here we present the design of an innovative, label-free, noninvasive, rapid Raman spectroscopy-based method for pRBCs quality evaluation, starting with the description of sample measurement and data analysis, through correlation of spectroscopic results with reference techniques' outcomes, and finishing with methodology verification and its application in clinical conditions. We have shown that Raman spectra collected from the pRBCs supernatant mixture with a proper chemometric analysis conducted for a minimum one ratio of integral intensities of the chosen Raman marker bands within the spectrum allow evaluation of the pRBC quality in a rapid, noninvasive, and free-label manner, without unsealing the pRBCs bag. Subsequently, spectroscopic data were compared with predefined reference values, either from pRBCs expiration or those defining the pRBCs quality, allowing to assess their utility for transfusion to patients with acute myeloid leukemia (AML) and lymphoblastic leukemia (ALL).

Wind characteristics in typhoon boundary layer at coastal areas observed via a Lidar profiler

Information about typhoon wind characteristics provides a basis and is a prerequisite for conducting anti-typhoon studies and practices. Despite the great efforts and active exploration made in the field of typhoon measurements using various equipment over the past decades, how to effectively obtain both the mean and fluctuating components of typhoon wind especially within the atmospheric boundary layer around the inner region of the storm still remains as a challenge. In recent years, Lidar wind profilers have been attracting increasing attention and showing great promise owing to their advantages, such as wide detection range, high sampling frequency, handiness, and flexible layout. However, the results for turbulent wind components using Lidar wind profilers tend to be biased due to the intrinsic spatial average in remote sensing detection. In view of the above, this paper explores the use of the Lidar wind profiler to conduct legitimate measurements of typhoon averages and fluctuating wind field characteristics. Firstly, wind field measurements in the inner regions of two typhoons were successfully captured during their passage with the flexible deployment of equipment in coastal areas. Based on the data obtained, the mean wind field characteristics of the typhoons were examined during different transitional stages and under different exposure conditions, with a focus on the influence of inner boundary layer on the vertical wind speed profile and its key parameters, such as surface roughness and zero-plane displacement. A method based on a wind spectrum model is proposed to correct the typical fluctuating wind field parameters, which include turbulence integral length scale, turbulence intensity, and gust factor. The difference between these wind turbulence parameters before and after the correction was significant, but the corrected results were in better agreement with similar existing results, reflecting the necessity and validity of the correction work. The presented results are expected to be helpful for further understanding of the wind characteristics in the middle and upper portions of typhoon boundary layer, and contribute to the development of using Lidar profiler for observing wind turbulence.

Tuning the thermal quenching properties of Ga3+-modified LiTaO3:Bi3+ phosphor through defect engineering strategy

Defects inside fluorescent materials are often an important cause of the anti-thermal quenching of fluorescent materials. Adjusting the thermal compensation effect of defects on luminous centers is often achieved by adjusting the types, quantities and depths of defect traps. In this contribution, we found that doping Ga3+ into LiTaO3 matrix containing intrinsic defects of lithium vacancies (VLi，) and antisite-tantalum (TaLi4+) resulted in Bi3+ from non-luminescence to luminescence. It is speculated that the luminescence is mainly due to the charge compensation of Ga3+ instead of Ta5+, which promotes the conversion from Bi2+ to Bi3+, and then makes phosphor produce obvious luminescence. Interestingly, due to the increase of Ga3+ content, when excited at 304 nm, the integral intensity of sample (0.10 Ga3+) at 420–470 nm is 1.98 times that of sample (0.01 Ga3+). The effect of defect traps on luminescent properties was characterized by thermoluminescence (TL) and X-ray photoelectron spectroscopy (XPS). It is confirmed that the thermal compensation from 303 to 383 K comes from VO··, BiLi2+, TaLi4+ and GaLi2+. And the proportion of these defects will change with the change of the heterovalent substitution of Ga3+/Ta5+. At the same time, the increase of Ga3+ concentration from 1 to 10% in defect modification results in the change of crystal structure, which also increases the Bi3+ band gap from 3.40 eV to 3.50 eV, thus increasing the proportion of the integral intensity of 423 K to original intensity of 303 K at 420–470 nm from 0.45 to 0.67. This defect engineering strategy of Ga3+ modification is helpful for a more complete understanding of the causes for the change of luminescence and thermal quenching characteristics of phosphors in the process of heterovalent substitution, as well as the development of anti-thermal quenching phosphors for high-quality w-LEDs.

Transcranial direct current stimulation combined with amantadine in repetitive mild traumatic brain injury in rats

BackgroundBalance and memory deficits are common in patients with repetitive mild traumatic brain injury (mTBI).ObjectiveTo investigate the combined effects of amantadine and transcranial direct current stimulation (tDCS) on balance and memory in repetitive mTBI rat models.MethodsIn this prospective animal study, 40 repetitive mTBI rats were randomly assigned to four groups: tDCS, amantadine, combination of amantadine and anodal tDCS, and control. The tDCS group received four sessions of anodal tDCS for four consecutive days. The amantadine group received four intraperitoneal injections of amantadine for four consecutive days. The combination group received four intraperitoneal injections of amantadine and anodal tDCS for four consecutive days. Motor-evoked potential (MEP), rotarod test, and novel object test results were evaluated before mTBI, before treatment, and after treatment.ResultsAll groups showed significant improvements in the rotarod and novel object tests, particularly the combination group. The combination group showed a significant improvements in duration (p < 0.01) and maximal speed in the rotarod test (p < 0.01), as well as an improvement in novel object ratio (p = 0.05) and MEP amplitude (p = 0.05) after treatment. The combination group exhibited a significant increase in novel object ratio compared to the tDCS group (p = 0.04). The GFAP integral intensity of the left motor cortex and hippocampus was the lowest in the combination group.ConclusionCombination treatment with amantadine and tDCS had positive effects on balance and memory recovery after repetitive mTBI in rats. Therefore, we expect that the combination of amantadine and tDCS may be a treatment option for patients with repetitive mTBIs.

The beam stop as an intensity monitor

Free-electron lasers (FELs) provide unique possibilities in investigating matter down to femtosecond time and nanometer length scales, as well as in the regime of non-linear light-matter interaction. Due to the nature of FEL sources, the produced beam is significantly more unstable than beams produced by 3rd generation synchrotrons. As a result, pulse-resolved normalization of measurement data becomes essential and can be challenging. The intensity monitors permanently installed at a facility might indeed accurately measure the pulse intensities at a certain point of the beamline, but cannot precisely normalize experimental data. For example the impact of pointing instabilities and hence different clipping of the beam downstream on the way to the actual experiment is not reflected in the intensity measurement. Here, we show how the integral intensity of the FEL beam transmitted through the sample can be measured by photodiodes providing a proper normalization of measurement data.

Application of quantitative analysis for aluminum alloy in femtosecond laser-ablation spark-induced breakdown spectroscopy using one-point and multi-line calibration

To achieve the quantitative elemental analysis of aluminum alloy samples, the one-point and multi-line calibration (OP-MLC) method and femtosecond laser-ablation spark-induced breakdown spectroscopy (fs-LA-SIBS) were combined in this study. An ultrafast Ti: sapphire laser with high single-pulse energy and high repetition–rate operation was used as the laser source to ablate the sample at a 1k Hz pulse repetition rate and achieve re-excitation using spark discharge. Subsequently, an enhanced spectral peak intensity was achieved, which increased the sensitivity and analytical capabilities of laser-induced breakdown spectroscopy (LIBS) technique. Considering only one confirmed sample, the OP-MLC method was used to calculate the concentration ratios of trace elements Mg, Cr, Cu, Mn and Zn in four aluminum alloy samples to the calibration samples by the integral intensity ratio of the elemental characteristic lines between the two samples. The average relative errors with the identified concentrations were 3.99%, 15.13%, 8.76%, 9.30% and 9.64%, respectively. The results showed that the combination of OP-MLC method and fs-LA-SIBS has good accuracy in the quantitative analysis of elements, and has the advantages of simplicity, rapidity and high sensitivity.