Peak Width Research Articles

Thermoluminescence in pumice stone collected from the Mediterranean coast.

Pumice is a low-density, light-coloured volcanic rock (igneous rock) formed when the magma from a volcanic eruption is suddenly cooled. It has a porous structure and can be different colours and have different densities. Pumice stone, unlike other rock, does not sink in water because it has a low density. In the present study, the thermoluminescent (TL) dosimetric characteristics, such as the dose-response, TL signal fading as a function of storage time, heating rate, and reusability of pumice collected on the Mediterranean coast were investigated. From this study, it was concluded that the pumice stone showed TL properties with a TL glow curve including an obviously wide peak at ∼200°C. A wide linear dose-response region up to 144 Gy, low fading of the TL signal when it was kept in a dark room for a long time, and poor reusability properties were observed for dosimetry use.

The use of a mini-ridge filter with cyclotron-based pencil beam scanning proton therapy.

Pencil beam scanning (PBS) proton therapy allows for far superior dose conformality compared with passive scattering techniques. However, one drawback of PBS is that the beam delivery time can be long, particularly when treating superficial disease. Minimizing beam delivery time is important for patient comfort and precision of treatment delivery. Mini-ridge filters (MRF) have been shown to reduce beam delivery time for synchrotron-based PBS. Given that cyclotron systems are widely used in proton therapy it is necessary to investigate the potential clinical benefit of mini-ridge filters in such systems. To demonstrate the clinical benefit of using a MRF to reduce beam delivery time for patients with large target volumes and superficial disease in cyclotron-based PBS proton therapy. A MRF beam model was generated by simulating the effect of a MRF on our clinical beam data assuming a fixed snout position relative to the isocenter. The beam model was validated with a series of measurements. The model was used to optimize treatment plans in a water phantom and on six patient DICOM datasets to further study the effect of the MRF and for comparison with physician-approved clinical treatment plans. Beam delivery time was measured for six plans with and without the MRF to demonstrate the reduction achievable. Plans with and without MRF were reviewed to confirm clinical acceptability by a radiation oncologist. Patient-specific QA measurements were carried out with a two-dimensional ionization chamber array detector for one representative patient's plan optimized with the MRF beam model. Results show good agreement between the simulated beam model and measurements with mean and maximum deviations of 0.06mm (0.45%) and 0.61mm (4.9%). The increase in Bragg peak width (FWHM) ranged from 2.7mm at 226MeV to 6.1mm at 70 MeV. The mean and maximum reduction in beam delivery time observed per field was 29.1s (32.2%) and 79.7s (55.3%). MRFs can be used to reduce treatment time in cyclotron-based PBS proton therapy without sacrificing plan quality. This is particularly beneficial for patients with large targets and superficial disease such as in breast cancer where treatment times are generally long, as well as patients treated with deep inspiration breath hold (DIBH).

Theoretical study on spin-dependent zigzag-direction thermoelectric transport properties of Mn-doped blue phosphorene

With the increasing demand for energy, it has become imperative to investigate the thermoelectric properties that can be beneficial to directly converting heat into electric energy. Here, we theoretically study the thermoelectric transport of the Mn-doped blue phosphorene (blue-P) along the zigzag direction. We show that the spin-polarized electronic transport in the blue-P can be produced by the Mn-doping induced half-metallic energy band structure, and the Seebeck coefficients can take positive and negative values, indicating that the main carriers may be holes and electrons. Thus, the spin-down, spin, and charge Seebeck coefficients show a high peak and a deep valley, while the spin and charge thermoelectric figures of merit show two wide peaks. Moreover, the spin and charge thermoelectric figures of merit are found to be so large that the Mn-doped blue-P along the zigzag direction can be used as good thermoelectric materials. In addition, we consider the effect of the doping concentration on the electronic structure and thermoelectric transport properties. This research should be an important reference for designing spin caloritronic and thermoelectric devices.

The influence of torrefaction on the biochar characteristics produced from sesame stalks and bean husk

Torrefaction encourages homogeneity and enhances the energy-producing capabilities of biomass. In the current study, bean husk (BH) and sesame stalks (SS) were torrefied for 30 and 60 min at operating temperatures of 200, 225, 250 and 275, and 300 °C with nitrogen purging. Mass yield (MY), higher heating value (HHV), energy yields (EY), and torrefaction severity index (TSI) were examined. The variations of the biochar characteristics, pyrolysis kinetics by applying two models (Coats and Redfern (CR) and Direct Arrhenius (DA)), and crystallinity index (CRI) were depicted. Depending on pyrolysis kinetics, thermodynamic activation parameters were derived to elucidate biomass pyrolysis. The alterations in the torrefied materials’ composition were also analyzed using Fourier transform infrared spectroscopy (FTIR). The calculations revealed that the torrefied SS and BH decreased MY by 32.74, 29.02% and decreased EY 26, 20.97%, increased high heating values by 14.1, 13.52%, increased fixed carbon by 55.1, 39.91% respectively, and had a slight reduction in bulk density (approximately 2%). Generally, 275 °C and 30 min were the optimal conditions for a balanced torrefaction of SS and BH based on the HHV that reached to 20.5, 16.2 MJ/kg and EY that reached to 86.16 and 85.56% respectively. The FTIR, XRD, and the thermogravimetric results showed that the torrefaction treatment altered samples owing to carbohydrate breakdown, a rise in lignin, and a reduction in hemicellulose as the temperature of the torrefaction process increased. The CR methodology yielded greater frequency factor (A) and activation energy (Ea) values than the DA method. The broadest peak width, lowest average Ea, and lnA were seen in sesame stalks that had been torrefied at 300 °C and 30 min that reached to 107.85 (kJ/mol) and 13.57 (min−1). Results indicated an excellent linear relationship with the index of comprehensive pyrolysis (CPI), CRI, atomic H/C ratio, severity index, and EY.

Application of Poultry Gelatin to Enhance the Physicochemical, Mechanical, and Rheological Properties of Fish Gelatin as Alternative Mammalian Gelatin Films for Food Packaging.

This study aimed to describe the properties of cold water fish gelatin (FG) blended with poultry gelatin (PG) for a production of a sachet containing olive oil. To find a desirable film, the different ratio of FG-PG-based films were characterized in terms of mechanical properties. As the proportion of PG in PG-FG-based increased, the tensile strength and Young's modulus were increased, and the elongation at break and heat seal strength of the films were decreased. The 50-50 film had favorable characteristics to use as a sachet. The amount of acid index and peroxide of the oil stored in the sachets after 14 days showed that there is a significant difference (p < 0.05) between the films. The barrier properties of the films including the water vapor permeability and oxygen permeability of films were increased from 1.21 to 4.95 × 10-11 g m-1 Pa-1 s-1 and 48 to 97 cm3 mµ/m2 d kPa, respectively. Dark, red, yellow, and opaque films were realized with increasing PG. Fourier transform infrared (FTIR) spectra approved a wide peak of approximately 2500 cm-1. The rheological analysis indicated that, by adding PG, viscosity, elastic modulus (G') and loss modulus (G'') were increased significantly (p < 0.05) about 9.5, 9.32 and 18 times, respectively. Therefore, an easy modification of FG with PG will make it suitable for oil sachet packaging applications for the food industry.

Research Progress on the Point-defect Relaxation in β-Ti Alloys

The anelastic relaxation is measured at a low and high frequency from low to high temperature in some Ti alloys, most of which are usually recorded in the internal friction-temperature spectra. In this paper, the point-defect relaxation in β-Ti alloys is described and discussed. The point defects are the interstitial impurity atoms, substitution atoms and vacancies in β-Ti alloys. The reorientation of interstitial impurity O atoms around matrix Ti and substitute atoms produces Snoek-type peaks. The various interactions between the interstitial impurity atoms (O,N,et al.) and matrix atoms/substitute atoms (Ti, Nb,Mo,V,et al. ) can also produce a complex relaxation spectra consisting of several Snoek-type peaks. The concentrations of interstitial impurity atoms and the substitute atoms have important roles on the height and width of the Snoek-type peaks. The reorientation of defect pairs consisting of the interstitial impurity atoms and vacancies is also involved in the relaxation processes. At high temperatures, the Mo-Mo atom-pairs can be reoriented under the inducing of cycle stress and produce similar Zener relaxation peak.

Rapid and simultaneous determination of two immunosuppressants in whole blood by high performance liquid chromatography

Cyclosporine A and sirolimus are immunosuppressants that are widely used in many organ transplantation procedures. They exhibit some complementary mechanisms of action and interact synergistically when used together. However， they are critical-dose drugs and have a narrow therapeutic index. They provide the desired therapeutic effect with acceptable tolerability only within a specific range of blood concentrations. Therefore， the rapid and simultaneous detection of the concentrations of cyclosporine A and sirolimus in whole blood could provide valuable information on planning medicine administration after organ transplantations. In this study， firstly， the chromatographic behaviors of cyclosporine A and sirolimus on a biological liquid chromatography （BioLC） column and traditional liquid chromatography （TraLC） columns were investigated systematically under the same chromatographic conditions. The results suggested that the peak height and peak width of cyclosporine A and sirolimus on the BioLC column， ZORBAX 300SB C8 （250 mm×4.6 mm， 5.0 μm）， were the highest and narrowest， respectively. The number of theoretical plates of cyclosporine A and sirolimus on the ZORBAX 300SB C8 column increased significantly when the volume ratio of acetonitrile in the mobile phases was greater than 70%. Their retention time on the BioLC and TraLC columns was negligibly affected by the use of formic acid and trifluoroacetic acid as the mobile phases. In the range of the experimental column temperature， the number of theoretical plates of cyclosporine A and sirolimus on the ZORBAX 300SB C8 column was significantly higher than that on the two TraLC columns. Furthermore， the relationship between the retention factor and column temperature of cyclosporine A on the ZORBAX 300SB C8 column was different from that on the two TraLC columns. Subsequently， a high performance liquid chromatography method based on the ZORBAX 300SB C8 column was established for the rapid separation and determination of cyclosporin A and sirolimus in whole blood. A sample of whole blood with a volume of 50 μL was prepared by protein precipitation with 1 mol/L sodium hydroxide and then extracted into 500 μL of ether-methanol （95∶5， v/v）. After centrifugation at 14000 r/min for 10 min， the organic layer was removed and evaporated under a stream of nitrogen at 50 ℃. The residue was then reconstituted in 200 μL of methanol for use. Cyclosporin A and sirolimus were separated through isocratic elution on the ZORBAX 300SB C8 column. The column temperature was set at 60 ℃. The mobile phase was acetonitrile-water （70∶30， v/v） and the flow rate was 1.0 mL/min. The detection wavelengths were 205 nm for cyclosporine A and 278 nm for sirolimus. The injection volume was 20 μL. The external standard method was used to quantify cyclosporine A and sirolimus. Under the optimized conditions， cyclosporine A and sirolimus were well-separated within 6 min with a resolution of 3.7 at 205 nm. In addition， the endogenous substances in whole blood negligibly interfered in the detection of sirolimus， while two endogenous substances slightly affected the detection of cyclosporine A. Cyclosporine A and sirolimus both showed good linear relationships in their respective concentration （r>0.997）. The limits of detection （LODs） of cyclosporine A and sirolimus were respectively calculated to be 10 ng/mL and 1 ng/mL based on a signal-to-noise ratio of 3， and the limits of quantification （LOQs） were 30 ng/mL and 2 ng/mL based on a signal-to-noise ratio of 10. In the whole blood samples， the recoveries of cyclosporine A and sirolimus at three spiked levels were in the ranges of 83.5%-89.7% and 95.8%-97.8% with relative standard deviations （RSDs） of 3.2%-9.0% and 3.4%-6.7% （n=5）， respectively. The established method is simple in operation， can be performed with a simple mobile phase， has a short analysis time， and provides a wide linear range and high sensitivity； hence， it can be applied to the determination of cyclosporine A and sirolimus in whole blood.

Abstract 162: Molecular And Microstructural Alterations In Cerebral Amyloid Angiopathy-related Hemorrhagic Manifestations

Background and Purpose: We aimed to compare the amyloid load and degree of microstructural injury among Cerebral Amyloid Angiopathy (CAA) patients with either higher lobar cerebral microbleed (CMB) counts or higher cortical superficial siderosis (cSS) extent against CAA patients with lower hemorrhagic load. Methods: The study included 38 cognitively healthy probable CAA patients with lobar intracerebral hemorrhage (ICH) and 38 age, sex-matched healthy controls (HC) who underwent advanced MRI, and Pittsburgh Compound B (PiB) PET scans. Patients were categorized into CMB-Dominant (CMB-D) and cSS-Dominant (cSS-D) based on the number and extent of CMB and cSS using previously identified cutoffs (Figure). The mean global cortical amyloid load was calculated from PiB-PET scans and represented by PiB-DVR. Within the CAA cohort, the Peak Width of Skeletonized Mean Diffusivity (PSMD) was calculated from diffusion MRIs and used as a marker of microstructural integrity. Results: Patients with CAA had significantly higher PiB-DVR than HCs (1.40±0.24 vs. 1.19±0.22, p&lt;0.001). Both CMB-D and cSS-D CAA patients had significantly higher amyloid and increased (worse) PSMD compared to CAA patients with a non-dominant low hemorrhagic load (Figure). These results did not change in separate regression models corrected for age and sex. PiB-DVR significantly correlated with increased PSMD (r=0.346, p=0.033). Conclusions: Our findings support the view that vascular amyloid load drives higher CMB counts, more extensive cSS, and microstructural injury in patients with CAA. Furthermore, the correlations among these markers suggest that these MRI-based categorizations (CMB-D and cSS-D patients) can be used for disease staging and further research.

Short-Term and Long-Term Outcomes of Fetal Ventriculomegaly beyond Gestational 37 Weeks: A Retrospective Cohort Study.

Birth defects have brought about major public health problems, and studying the clinical outcomes of the most common prenatal central nervous system abnormality, namely, fetal ventriculomegaly (VM), is helpful for improving reproductive health and fertility quality. This is a retrospective cohort study from 2011 to 2020 in the West China Second University Hospital, Sichuan University, aiming to evaluate the short-term and long-term outcomes of VM over 37 weeks' gestation to exclude the influence of preterm birth. The study analyzed data from 401 term pregnancies, with 179 VM and 222 controls. From the short-term outcomes, the rate of the neonatal intensive care unit (NICU) admission under the VM group (10.06%) was comparatively higher than the control (0.45%), but Apgar scores between both groups at 1 min, 5 min and 10 min were not significantly different. From the long-term outcomes, there were more infants with abnormal neurodevelopment under the VM group than control (14.53% vs. 2.25%, p < 0.001). In addition, NICU admission (p = 0.006), peak width of lateral ventricles (p = 0.030) and postnatal cranial ultrasound suggestive with VM (p = 0.002) were related to infants' long-term outcomes. NICU admission during the perinatal period was an independent risk factor for the adverse long-term outcomes (OR = 3.561, 95% CI 1.029-12.320, p = 0.045). In conclusion, VM impairs short-term and long-term outcomes of term infants. Short-term outcome, especially NICU admission, could predict their adverse long-term outcomes.

Association between Coffee Consumption and Brain MRI Parameters in the Hamburg City Health Study.

Despite associations of regular coffee consumption with fewer neurodegenerative disorders, its association with microstructural brain alterations is unclear. To address this, we examined the association of coffee consumption with brain MRI parameters representing vascular brain damage, neurodegeneration, and microstructural integrity in 2316 participants in the population-based Hamburg City Health Study. Cortical thickness and white matter hyperintensity (WMH) load were measured on FLAIR and T1-weighted images. Microstructural white matter integrity was quantified as peak width of skeletonized mean diffusivity (PSMD) on diffusion-weighted MRI. Daily coffee consumption was assessed in five groups (<1 cup, 1-2 cups, 3-4 cups, 5-6 cups, >6 cups). In multiple linear regressions, we examined the association between brain MRI parameters and coffee consumption (reference group <1 cup). After adjustment for covariates, 3-4 cups of daily coffee were associated with lower PSMD (p = 0.028) and higher cortical thickness (p = 0.015) compared to <1 cup. Moreover, 1-2 cups per day was also associated with lower PSMD (p = 0.022). Associations with WMH load or other groups of coffee consumption were not significant (p > 0.05). The findings indicate that regular coffee consumption is positively associated with microstructural white matter integrity and cortical thickness. Further research is necessary to determine longitudinal effects of coffee on brain microstructure.

A Robust Method for the Elaboration of SiO2-Based Colloidal Crystals as a Template for Inverse Opal Structures.

Photonic crystals (PCs) are nanomaterials with photonic properties made up of periodically modulated dielectric materials that reflect light between a wavelength range located in the photonic band gap. Colloidal PCs (C-PC) have been proposed for several applications such as optical platforms for the formation of physical, chemical, and biological sensors based on a chromatic response to an external stimulus. In this work, a robust protocol for the elaboration of photonic crystals based on SiO2 particle (SP) deposition using the vertical lifting method was studied. A wide range of lifting speeds and particle suspension concentrations were investigated by evaluating the C-PC reflectance spectrum. Thinner and higher reflectance peaks were obtained with a decrease in the lifting speed and an increase in the SP concentrations up to certain values. Seven batches of twelve C-PCs employing a SP 3% suspension and a lifting speed of 0.28 µm/s were prepared to test the reproducibility of this method. Every C-PC fabricated in this assay has a wavelength peak in a range of 10 nm and a peak width lower than 90 nm. Inverse-opal polymeric films with a highly porous and interconnected morphology were obtained using the developed C-PC as a template. Overall, these results showed that reproducible colloidal crystals could be elaborated on a large scale with a simple apparatus in a short period, providing a step forward in the scale-up of the fabrication of photonic colloidal crystal and IO structures as those employed for the elaboration of photonic polymeric sensors.

Implementation of Sphinx/Lynx as daily QA equipment for scanned proton and carbon ion beams.

Reporting on the first implementation of a proton dedicated commercial device (IBA Sphinx/Lynx) for daily Quality Assurance (QA) of scanned proton and carbon ion beams. Daily QA trendlines over more than 3 years for protons and more than 2 years for carbon ions have been acquired. Key daily QA parameters were reviewed, namely the spot size and position, beam range, Bragg peak width, coincidence (between beam and imaging system isocenters), homogeneity and dose. The performance of the QA equipment for protons and carbon ions was evaluated. Daily QA trendlines allowed us to detect machine performance drifts and changes. The definition of tolerances and action levels is provided and compared with levels used in the literature. The device has been successfully implemented for routine daily QA activities in a dual particle therapy facility for more than 2 years. It improved the efficiency of daily QA and provides a comprehensive QA process.

A Study Coastal Protection Using Stones Crushed and Tetrapod (Case study at Ujong Blang Beach)

Ujong Blang Beach and Jagu Beach are in Lhokseumawe City. The purpose of this study was to plan a breakwater along the coast of Ujong Blang as an alternative for coastal protection. This includes specifying the details of the breakwater layers and calculating the dimensions of the breakwater. Applying the Hudson method to obtain the diameter and weight of stones grains. The protective layer material uses crushed stones and tetrapods. The results of the analysis obtained breakwater dimensions obtained based on a slope of 1: 2. The results of the analysis that have been obtained are made in the drawing 2D as a result of designing rock mounds with a slope of 1: 2. Breakwaters are planned in a position to protect the coast from waves. The planned breakwater height is 6.32 meters so it has the same elevation and crest dimensions, but the material volume will change less due to the lower contour differences in the sea.This type of breakwater is suitable for Ujong Blang beach, because it will have a good effect on the tourism business. The number of protected layer grains on a slope of 1:2 has a material use of 0.23 tons of tetrapods and a peak width of 3.5 meters.

Charge Transfer Reactions from I- to Polar Protic Solvents Studied Using Ultrafast Extreme Ultraviolet Photoelectron Spectroscopy.

Charge transfer reactions from I- to solvent water, methanol, and ethanol were studied using extreme ultraviolet time-resolved photoelectron spectroscopy (EUV-TRPES). This technique eliminates spectral broadening, previously seen in UV-TRPES, caused by electron inelastic scattering in liquids, and enables clear observation of the temporal evolution of the spectral shape. The peak position, width, and intensity of the electron binding energy distribution indicate electron detachment and subsequent solvation and thermalization processes. Geminate recombination between detached electrons and iodine atoms is discussed using a diffusion equation and a global fitting analysis based on a kinetics model.

Peak Width of Skeletonized Mean Diffusivity: A Neuroimaging Marker for White Matter Injury.

A leading cause of white matter (WM) injury in older individuals is cerebral small vessel disease (SVD). Cerebral SVD is the most prevalent vascular contributor to cognitive impairment and dementia. Therapeutic progress for cerebral SVD and other WM disorders depends on the development and validation of neuroimaging markers suitable as outcome measures in future interventional trials. Diffusion-tensor imaging (DTI) is one of the best-suited MRI techniques for assessing the extent of WM damage in the brain. But the optimal method to analyze individual DTI data remains hindered by labor-intensive and time-consuming processes. Peak width of skeletonized mean diffusivity (PSMD), a recently developed fast, fully automated DTI marker, was designed to quantify the WM damage secondary to cerebral SVD and reflect related cognitive impairment. Despite its promising results, knowledge about PSMD is still limited in the radiologic community. This focused review provides an overview of the technical details of PSMD while synthesizing the available data on its clinical and neuroimaging associations. From a critical expert viewpoint, the authors discuss the limitations of PSMD and its current validation status as a neuroimaging marker for vascular cognitive impairment. Finally, they point out the gaps to be addressed to further advance the field.

2H-MoS 2 Modified Nitrogen-Doped Hollow Mesoporous Carbon Spheres as the Efficient Catalytic Cathode Catalyst for Aprotic Lithium-Oxygen Batteries

2H-MoS ₂ Modified Nitrogen-Doped Hollow Mesoporous Carbon Spheres as the Efficient Catalytic Cathode Catalyst for Aprotic Lithium-Oxygen Batteries

1D Chiral Lead Bromide Perovskite with Superior Second-Order Optical Nonlinearity, Photoluminescence, and High-Temperature Reversible Phase Transition.

Multifunctional materials are an attractive research area. Organic-inorganic hybrid perovskites are widely used in the design of these materials due to their rich properties and flexible composition. It is easy to obtain more photoelectric properties by introducing chiral groups as ligands. In this work, we synthesized chiral one-dimensional organic-inorganic hybrid perovskites, namely (R/S-3-HP)PbBr3 (1R/1S) (3-HP=3-hydroxy-piperidine). The enantiomer compounds undergo reversible phase transition at 349/336 K. Under the excitation light of 339 nm, 1R and 1S have a wide emission peak at 635 nm, showing orange light. In addition, the indirect bandgap is 3.29 eV and the SHG intensity is comparable to that of KDP. This work provides a way to design multifunctional chiral perovskite materials.

Electronic structure and anharmonic phonon mode in BaIr2Ge7 with two-dimensional Ba-Ge networks studied by photoemission spectroscopy

We report the electronic structure of ${\mathrm{BaIr}}_{2}{\mathrm{Ge}}_{7}$ with two types of cage structure by means of angle-resolved photoemission spectroscopy (ARPES) and hard x-ray photoemission spectroscopy. ARPES spectra reveal the three-dimensional and multiband Fermi surfaces (FSs) originating from the hybridized Ir $5d$ and Ge $4p$ orbitals. The observed FSs show ${C}_{2}$ symmetry, reflecting the orthorhombic $Ammm$ crystal structure of ${\mathrm{BaIr}}_{2}{\mathrm{Ge}}_{7}$. The temperature dependence of the ARPES spectra exhibits the thermal spectral broadening, and the width of the spectral peak shows a concave-downward behavior with temperature. Considering the effect of anharmonic phonon modes, we have reproduced the temperature dependence of the electrical resistivity as well as the thermal spectral broadening. The resultant renormalized phonon frequencies ${\ensuremath{\omega}}_{\mathrm{r}0}^{(1)}=146.9\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ and ${\ensuremath{\omega}}_{\mathrm{r}0}^{(2)}=70.6\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ are comparable to the Einstein temperatures estimated from the previous specific heat measurement. Our results suggest the existence of the weak anharmonic phonon modes in ${\mathrm{BaIr}}_{2}{\mathrm{Ge}}_{7}$.

Improving the spectral resolution and measurement range of quantum microwave electrometry by cold Rydberg atoms

We theoretically and experimentally studied quantum microwave electrometry in a cold atomic system using Rydberg electromagnetic induction transparency (EIT) and Autler–Townes splitting (EIT-AT splitting). In cold atoms, a spectral linewidth of ∼500 kHz for EIT was achieved owing to a significant reduction in residual Doppler width, i.e. by at least an order of magnitude, compared to that in vapor cells at room temperature. Therefore, the minimum microwave electric field intensity (E MW) that can be measured is 430 µV cm−1, which is one order higher sensitivity in the EIT-AT regime than that in vapor cells at room temperature. Unlike microwave electrometry in atomic vapor cells, EIT-AT splitting cannot be observed if E MW is so large that the EIT-AT splitting interval exceeds the absorption peak width of the cold atom while scanning the frequency of the probe laser (ω p ). Moreover, EIT-AT splitting can be observed if exceeds the natural linewidth of the intermediate states while scanning the coupling laser (ω c ) and maintains a high spectral resolution with a high signal-to-noise ratio. While scanning ω c , the upper microwave electric field intensity is limited by the scanning range of our setup. Using our system, we measure the maximum field to be 21.6 mV cm−1, nearly three times higher than that of 6.8 mV cm−1 while scanning ω p . The results indicate that the linear range of E MW measured using EIT-AT splitting considerably improves in cold Rydberg atoms.

Identification Protocols for Horizontal-to-Vertical Spectral Ratio Peaks

ABSTRACTPeaks in horizontal-to-vertical spectral ratios (HVSRs) of Fourier amplitudes from three-component recordings of ground vibrations without undue local anthropogenic influence are used to identify site resonances, which are an important component of site response. We address two topics: (1) how should HVSR peaks be identified and (2) are there appreciable differences in HVSR derived using different instruments recording microtremors and seismic strong ground motions? We propose identifying peaks by considering peak amplitudes relative to neighboring ordinates and peak width. The procedure incorporates a regression tree algorithm that can be tuned to conform with user preferences toward relatively “conservative” or “liberal” peak identification (producing few or many sites with peaks, respectively). We then investigate the consistency of microtremor-based HVSRs (mHVSRs) derived from seismometers and accelerometers, which show a high rate of false negatives (missed peaks) from accelerometers with a full scale of ± 2g or greater. In contrast, mHVSRs derived from collocated temporary and permanent seismometers (optimized to record teleseismic signals) have about 60%–80% consistency (with no apparent bias in peak attributes). This indicates that mHVSRs from accelerometers having a broad full scale are unreliable but that mHVSRs can be reliably obtained from temporary or permanent seismometers. Finally, we compare seismometer-based HVSR from microtremor and earthquake (eHVSRs) sources. Results are consistent for 60%–70% of sites (i.e., both either do or do not have significant peaks, and when peaks are present, they occur at similar frequencies, &amp;lt;20% change). For sites with an mHVSR peak, the rate of corresponding eHVSR peaks is nearly 50%, whereas for sites without an mHVSR peak the eHVSR peak rate is low (about 20%). The mismatch rate for mHVSR peak sites is sufficiently high that the use of eHVSR to derive site response models is likely too optimistic (overestimates model effectiveness); mHVSR is preferred for consistency with information available in forward applications.