FWHM Research Articles

Enhancement of the optical properties of a Dy3+:Sr3Gd2(BO3)4 crystal by Ca2+ co-doping

In this work, polycrystalline Dy3+:(Sr1-xCax)3Gd2(BO3)4 (x = 0–0.9) compounds doped with different concentrations of Ca2+ were synthesized by solid-state reaction. On the basis of their structural and spectral data, the optimal Ca2+ ions doping concentration of 60 at.% was determined. Then the Dy3+:(Sr0.4Ca0.6)3Gd2(BO3)4 crystal was obtained by the Czochralski (Cz) method. The crystal has a relatively high absorption cross-section at 453 nm, which is 0.98 × 10−21 cm2 (E//c) with a full width at half maximum (FWHM) of 9 nm (E//c). The maximum emission cross-section of the 4F9/2 → 6H13/2 transition at 576 nm is 5.62 × 10−21 cm2 (E//c) with a FWHM of 14 nm. The fluorescence quantum efficiency is 52.5 %. Compared with the Dy3+:Sr3Gd2(BO3)4 crystal, the emission cross-section and fluorescence quantum efficiency of the Dy3+:(Sr0.4Ca0.6)3Gd2(BO3)4 crystal have been significantly improved. These further increase the possibility of the crystal emitting a yellow laser.

Pressure-Induced Remarkable Spectral Red-Shift in Mn2+ -Activated NaY9 (SiO4 )6 O2 Red-Emitting Phosphors for High-Sensitive Optical Manometry.

To settle the low sensitivity of luminescent manometers, the Mn2+ -activated NaY9 (SiO4 )6 O2 red-emitting phosphors with splendid pressure sensing performances are developed. Excited by 408nm, the resulting products emit bright red emission originating from 4 T1 (4 G) → 6 A1 transition of Mn2+ , in which the optimal concentration of the activator ion is ≈1 mol%. Moreover, the admirable thermal stability of the developed phosphors is studied and confirmed by the temperature-dependent emission spectra, based on which the activation energy is derived to be 0.275eV. By analyzing the pressure-dependent Raman spectra, the structural stability of the synthesized compounds at extreme conditions is verified. Furthermore, the designed phosphors exhibit remarkable spectral red-shift at elevated pressure. Especially, as pressure increases from 0.75 to 7.16GPa, the emission band centroid shifts from 617.2 to 663.4nm, resulting in a high sensitivity (dλ/dP) of 7.00nm GPa-1 , whereas the full width at half maximum (FWHM) increases from 83.0 to 110.6nm, leading to the ultra-high sensitivity (dFWHM/dP) of 10.13nm GPa-1 . These achievements manifest that the designed red-emitting phosphors are appropriate for ultrasensitive optical manometry. More importantly, the developed manometer is a current global leader in sensitivity, when operating in the band-width mode, that is, FWHM.

In situ precipitation of high efficiency and high thermostability CsPbBr3 quantum dots in borosilicate glass for wide color gamut display

In situ precipitation of CsPbBr3 quantum dots (QDs) in glass is considered as one of the effective methods to overcome its instability and to achieve practical applications. However, it still faces the great challenges of low photoluminescence quantum yield (PLQY), poor thermostability and photostability at present. Herein, we successfully prepared CsPbBr3 QDs in situ within a well-designed glass matrix (CsPbBr3 QDs@glass), which exhibits symmetric narrowband emission at 523 nm with a full width at half maximum (FWHM) of 25 nm, giving a PLQY of up to 52.15 % under 455 nm excitation. Meanwhile, it can keep 45.25 % of the initial luminescence intensity at 373 K, better than that of most reported CsPbBr3 QDs@glass materials. As a demonstration of a conceptual application, a white LED backlight strip was fabricated at home by encapsulating CsPbBr3 QDs@glass composite and K2SiF6:Mn4+ red phosphor on blue chips with silicone, achieving a wide color gamut of 128.6 % and 95.8 % of NTSC and Rec. 2020 color gamut, respectively. The assembled CsPbBr3 QDs@glass-based LCD screen exhibits excellent color reproduction and color saturation. All these results demonstrate that this CsPbBr3 QDs@glass composite material is a promising green emitter for wide color gamut LCD display.

A simulation of a high-resolution cadmium zinc telluride positron emission tomography system.

A CZT (cadmium zinc telluride) PET (positron emission tomography) system is being developed at Stanford University. CZT has the promise of outperforming scintillator-based systems in energy and spatial resolution but has relatively poor coincidence timingresolution. To supplement GATE (GEANT 4 Application for Emission Tomography) simulations with charge transport and electronics modeling for a high-resolution CZT PET system. A conventional GATE simulation was supplemented with electron-hole transport modeling and experimentally measured single detector energy resolution to improve the system-level understanding of a CZT high-resolution PET system in development at Stanford University. The modeling used GATE hits data and applied charge transport in the crystal and RC-CR processing of the simulated signals to model the electronics, including leading-edge discriminators and peak pick-off. Depth correction was also performed on the simulation data. Experimentally acquired data were used to determine energy resolution parameters and were compared to simulationdata. The distributions of the coincidence timing, anode energy, and cathode energy are consistent with experimental data. Numerically, the simulation achieved 153 ns FWHM coincidence time resolution (CTR), which is of the same order of magnitude as the raw 210 ns CTR previously found experimentally. Further, the anode energy resolution was found to be 5.9% FWHM (full width at half maximum) at 511 keV in the simulation, which is between the experimental value found for a single crystal of 3% and the value found for the dual-panel setup of 8.02%, after depth correction. Developing this advanced simulation improves upon the limitations of GATE for modeling semiconductor PET systems and provides a means for deeper analysis of the coincidence timing resolution and other complementary electron-hole dependent systemparameters.

High sensitivity and optimum design of LSPR-based sensors by coupled nano-rings for cancer detection

Plasmonic RI sensors are widely used in various fields due to their high sensitivity and specificity; and is based on the change of the refractive index of the system. In this research work, we investigate an LSPR-based sensor consisting of two coupled silver nano-rings on a SiO2/Si substrate. The sensor's sensitivity, full width at half maximum (FWHM), and figure of merit (FOM) of the sensor are measured to be 393.14 nm/RIU, 53.2 nm, 7.39 RIU−1, respectively. The resonance peak is generated by the focused electric field in the elliptical area between the nano-rings. By assuming an etched area filled with the solution under the elliptical area between the nano-rings, we enhance the interaction between the solution and the penetrated electrical field in the SiO2 layer. This approach increases the sensitivity, FWHM, and FOM to 524.3 nm/RIU, 52.3 nm, 10.024 RIU−1, respectively. The designed sensor as a bio-sensor is capable of effectively detecting different types of cancerous cells from healthy cells, since the refractive index of a cell that affected by cancer, is higher than healthy cell. The simulation results show good selectivity for each type of cancer, with a FOM of approximately 9.5 RIU−1.

Essential Tremor and Essential Tremor Plus Are Essentially Similar Electrophysiologically.

The merits of classifying the heterogeneous group of essential tremors into essential tremor (ET) and essential tremor plus (ETP) are debated. We studied the electrophysiological and spiral characteristics of tremor in ET and ETP. We reviewed standardized videos from a tremor database and clinically classified patients into ET, ETP, or dystonic tremor (DT). The following variables were derived from combined tri-axial accelerometry-surface electromyography (EMG)-peak frequency, total power, peak power, full width half maximum, tremor stability index and EMG-coherence. We analyzed hand-drawn spirals to derive mean deviation, tremor variability, inter-, and intra-loop widths. We compared these variables among the groups. We recruited 72 participants (81.9% male) with mean age 47.7 ± 16.1 years and Fahn-Tolosa-Marin Tremor Rating Scale total score 31.1 ± 14.1. Patients with ET were younger (P = 0.014) and had less severe tremor (P = 0.020) compared to ETP and DT. In ETP group, 48.6% had subtle dystonia. Peak frequency was greater in ETP (7.3 ± 0.3 Hz) compared to DT (6.1 ± 0.4 Hz; P = 0.024). Peak power was greater in ETP and DT for postural tremor. Rest tremor was recordable on accelerometry in 26.7% of ET. Other variables were similar among the groups. Electrophysiological evaluation revealed postural tremor of frequency 6 to 7 Hz in ET, ETP, and DT with subtle differences more severe tremor in ETP and DT, and higher frequency in ETP compared to DT. Our findings suggest a similar tremor oscillator in these conditions, supporting the view that these entities are part of a spectrum of tremor disorders, rather than distinct etiological entities.

High Output Power and High Quantum Efficiency in Novel NIR Phosphor MgAlGa0.7 B0.3 O4 :Cr3+ with Profound FWHM Variation.

There is strong demand for ultraefficient near-infrared (NIR) phosphors with adjustable emission properties for next-generation intelligent NIR light sources. Designing phosphors with large full-width at half-maximum (FWHM) variations is challenging. In this study, novel near-ultraviolet light-emitting diode(LED)-excited NIR phosphors, MgAlGa0.7 B0.3 O4 :Cr3+ (MAGBO:Cr3+ ), with three emission centers achieve ultra-narrowband (FWHM = 29nm) to ultra-broadband (FWHM = 260nm) emission with increasing Cr3+ concentration. Gaussian fitting and decay time analysis reveal the alteration in the FWHM, which is attributed to the energy transfer occurring between the three emission centers. The distinct thermal quenching behaviors of the three emission centers are revealed through the temperature-dependent decay times. The ultra-broadband NIR phosphor MAGBO:0.05Cr3+ exhibits high thermal stability (85%, 425 K) and exceptional external quantum efficiency of 68.5%. An NIR phosphor-converted LED (pc-LED) is fabricated using MAGBO:0.05Cr3+ phosphor, exhibiting a remarkable NIR output power of 136mW at 600mA in ultra-broadband NIR pc-LEDs. This study describes the preparation of highly efficient phosphors and provides a further understanding of the tunable FWHM, which is vital for high-performance NIR phosphors with versatile applications.

Hybrid fiber–solid-state laser with 3D-printed intracavity lenses

Microscale 3D-printing has revolutionized micro-optical applications ranging from endoscopy, imaging, to quantum technologies. In all these applications, miniaturization is key, and in combination with the nearly unlimited design space, it is opening novel, to the best of our knowledge, avenues. Here, we push the limits of miniaturization and durability by realizing the first fiber laser system with intra-cavity on-fiber 3D-printed optics. We demonstrate stable laser operation at over 20 mW output power at 1063.4 nm with a full width half maximum (FWHM) bandwidth of 0.11 nm and a maximum output power of 37 mW. Furthermore, we investigate the power stability and degradation of 3D-printed optics at Watt power levels. The intriguing possibilities afforded by free-form microscale 3D-printed optics allow us to combine the gain in a solid-state crystal with fiber guidance in a hybrid laser concept. Therefore, our novel ansatz enables the compact integration of a bulk active media in fiber platforms at substantial power levels.

Tailoring quantum dots through citric acid modulation of CoFe2O4 ferrite

In the pursuit of advancing materials science, the focus has been on the development of Quantum dot CoFe2O4, a fascinating realm where the minuscule holds the key to great potential. By utilizing the cost-effective sol-gel method and adjusting the concentration of citric acid, we embarked on a journey to explore the intricacies of this magnetic material. XRD measurements determined the phase and structural characteristics of the synthesized cobalt ferrite. The Rietveld refinement clearly shows the single-phase cubic structure described by Fd-3m space group. The broad peak indicates the Quantum dots and nano sized particles depending on the FWHM, also the Debye Scherrer formula has been used to calculate the crystallite size of the prepared sample. It was found that the average crystallite size of different samples of CoFe2O4 lied in the range of 4.8–38.4 nm (Quantum dot to Nanometer range). The FWHM (full width at half maximum) broadening varied according to the citric acid, as the amount of citric acid increased, the FWHM decreased, which has been clearly seen in the XRD pattern. The required calculations were performed to ascertain micro-strain in the sample with the help of the W–H plot. For the surface morphological study, Field Emission Scanning Electron Microscopy (FE-SEM) was performed for all samples, which suggested that all samples were well prepared and were in spherical shape. The EDAX confirmed the elemental composition present in the prepared samples of CoFe2O4. The Raman spectra supports our XRD data also deconvoluted Raman spectras suggest about the vibrational modes present in the sample and the three strong first-order Raman modes Eg, T2g, and A1g, were observed. As we delved deeper into vibrational harmonies, Raman spectroscopy unveiled a symphony of modes. The presence of different chemical bonds has been confirmed by the Fourier Transform Infrared Rays (FTIR) Spectroscopy.

FMMAS-OCT: Aberration correction for high-resolution cellular imaging

In optical coherence tomography (OCT), spatial resolution and signal strength often suffer due to aberrations from both the imaging system and the sample. In this work, we introduce a novel method, FMMAS (Forward-Model Multiple Aperture Synthesis), which effectively compensates for these aberrations. It combines forward-model (FM) based method for transverse resolution restoration and multiple aperture synthesis (MAS) to mitigate depth domain aberrations. Our proof-of-concept experiment demonstrates a significant improvement in the mean transverse full width at half maximum (FWHM) of microparticles by 46.1 %. Compared to original OCT and FM method, FMMAS produces sharper, 'pencil beam'-like imaging, resolving cell nuclei in swine esophagus ex vivo and human blood cells in vivo, suggesting a potential for significant enhancements in OCT image quality.

Electromagnetic jet produced with loaded waveguide ended by an optimized multi-rectangular sections tip

Previous works have demonstrated that a parallel plate waveguide, equipped at the end with a tip, can be used to initiate an “electromagnetic jet (Ej)” (this name generalizes the photonic jet (Pj) phenomenon regardless of the wavelength). In addition to being easy to manufacture, a rectangular shape improves energy concentration, however concurrently the full-width at half maximum (FWHM) is slightly degraded. This article aims to introduce tips with multi-rectangular sections reducing the drawbacks previously mentioned. This article proposes the use of Aperiodic Polynomial Modal Method (A-PMM) as an efficient yet robust method to model and optimize an outgoing Ej, equipped with this kind of dielectric tips. Thus, a three rectangular sections tip can improve energy concentration and can reduce the FWHM beyond the diffraction limit compared to a single section tip.

Centimeter-Sized Single Crystals of Tetrahedral Manganese (II) Halide Hybrids for Wide-Color Gamut Backlighting Displays.

Phosphors with narrow-band green emissions and high photoluminescent quantum efficiency (PLQY) are significantly required for backlighting displays with wider color gamut. In this work, two centimeter-sized manganese (II) halide single crystals TMG2MnCl4 and TMG2MnBr4 (TMG = 1,1,3,3-tetramethylguanidine) are synthesized, exhibiting bright narrow-band green emissions with high PLQYs up to 62% and 90%, respectively. The narrow-band green light emission is located at 520nm with a full-width at half-maximum (FWHM) of only 57nm. The photoluminescence mechanisms of two single crystals are elaborated. Two white-light-emitting diodes for backlighting displays (BD-WLEDs) based on them are fabricated, exhibiting the widest color gamut of 122% National Television Standards Committee (NTSC), and a luminous efficacy reached ≈93lmW-1 with excellent luminescence stability at high temperatures. These properties indicate the potential applications of tetrahedral manganese (II) hybrids in wide-color gamut backlighting displays.

Thermally stable broadband near-infrared emitting pyrochlore oxide phosphors codoped with Cr3+ and Yb3+ ions

The advance of portable and smart near-infrared (NIR) light sources has sparked significant interest. However, achieving high-performance NIR emission at longer wavelengths remains a formidable challenge. In this study, we prepared broadband NIR phosphors by codoping pyrochlore oxide Y2GaSbO7 (YGSO) with Cr3+ and Yb3+ ions using a conventional high-temperature solid-state reaction. Upon excitation by blue light, YGSO: 0.03Cr3+ exhibited a broadband NIR emission centered at 765 nm with a full width at half maximum (FWHM) of 160 nm. The purposeful incorporation of Yb3+ ions facilitated efficient energy transfer from Cr3+ to Yb3+, resulting in a newly observed NIR emission peak at 970 nm. Notably, the addition of Yb3+ improved the overall thermal quenching resistance owing to its inherent thermal stability. Furthermore, we encapsulated the as-obtained phosphors with commercial blue LED chips to create prototype phosphor-converted light-emitting diodes (pc-LEDs). The Cr3+ and Cr3+-Yb3+ codoped pc-LEDs achieved output powers of 120 mW@660 mA with a photoelectric conversion efficiency of 12.66%@30 mA, and 131.7 mW@1020 mA with a photoelectric conversion efficiency of 13.93%@30 mA, respectively. These broadband NIR pc-LEDs hold promise for optical imaging applications.

Effects of retarders on the rheological properties of coal fly ash/superfine iron tailings-based 3D printing geopolymer: Insight into the early retarding mechanism

To increase the utilization rate of superfine iron tailings (SIT), a novel coal fly ash (CFA)/SIT-based three-dimensional printing geopolymers (CS-3DPG) were synthesized for high-value resource application of SIT. The optimal preparation parameters of CS-3DPG were sodium citrate of 0.4%, water-solid ratio of 38%, SiO2/Na2O molar ratio of 1 and alkali activator of 6%, with the compressive strength of 32.14 MPa. Besides, the yield stress and plastic viscosity (rheological properties) of CS-3DPG reached 284 Pa and 18.8 Pa·S, respectively. The sodium aluminum silicate hydrate (N-A-S-H) gels were identified as dominant hydration products by the selective chemical extractions. Microstructural analysis also successfully indicated that the retarder caused some CFA and SIT to be unreacted, resulting in the decrease of early compressive strength compared with CS-3DPG. Based on the full width at half-maximum (FWHM) values, kinetics of hydration and hydration kinetic contribution degree results, retarders effectually inhibited nucleation and growth (NG) and diffusion (D). The phase-boundary interaction (I) reaction played a major role after adding retarders. This work successfully reveals the early retarding mechanism of CS-3DPG, and provides the possibility of large-scale resource application of SIT-based 3DPG in 3D printing construction.

Characterization and effect of mechanical and thermal activation in mining tailings for use as supplementary cementitious material

The objective of this work is to evaluate the potential use of gold and silver tailings (GST) as Supplementary Cementitious Material (SCM). Physical, chemical, and mineralogical characteristics of GST were evaluated. Based on the initial characterization of GST, mechanical and thermal activation were proposed to improve GST reactivity. The effect of both activation processes in crystallite size and Full Width at Half Maximum (FWHM) were determined by X-Ray Diffraction (XRD). Mechanical activation at 140 min of milling and thermal activation at 1000 °C allowed the most significant reduction of crystallite size and particle size. The unconfined compressive strength (UCS) and the Strength Activity Index (SAI) were tested in mortar cubes partially substituted with activated tailings. Results showed that 10, 15, and 20 wt% substitution with activated tailings exceed the 75% SAI according to ASTM standards. Micrographs showed the presence of a calcium silicate hydrate (C-S-H) gel rich matrix in experimental mortars.

Efficient energy levels and lifetimes regulation of excited states for narrowband thermally activated delayed fluorescence

Multiple resonance thermally activated delayed fluorescence (MR-TADF) materials attract much attention owing to their 100 % exciton utilization, high photoluminescence quantum yield (PLQY) and narrowband emission with high color purity. However, how to regulate the energy levels and lifetimes of excited states for long-wavelength and short delayed fluorescence lifetime MR-TADF materials is still a challenge. Herein, an electron acceptor unit of pyrimidine derivative is introduced with steric-hinerance effect. The emission spectrum of BN-DPP is red shifted with 15 nm and the full width at half maximum (FWHM) is even narrower of 20 nm compared with that of DtCZB. A yellow-green MR-TADF material, called BN-DPBQ, is fabricated by extended the conjugation. Moreover, the delayed fluorescence lifetime of BN-DPBQ is half of that of BN-DPP. The BN-DPP based devices exhibit greenish blue emission with peak locating at 494 nm and maximum external quantum efficiency (EQE) of 23.6 %. BN-DPBQ based ones show much red shifted spectrum with emission peak at 538 nm and maximum EQE of 20.3 %. The results indicate that introducing electron acceptor units with steric-hinerance effect and extending the conjugation of resonance skeleton are effective ways to regulate energy levels and lifetimes of excited states for MR-TADF.

Robust efficiency stability and excellent aging resistance broadband NIR all-inorganic LEDs based on Tellurium-doped germanate glasses for multifunctional applications

Broadband near-infrared (NIR) spectroscopy based on glass-converted light-emitting diodes (gc-LEDs) has been of great interest to multifunctional applications ranging from night vision to chemical industry, stimulating the demand for exploring broadband NIR gc-LEDs with sufficient efficiency stability and aging resistance. Herein, an all-inorganic broadband NIR LEDs based on Te cluster-doped germanate glass is developed. Via adjustment of melting atmosphere and network topology of the glass matrix, active NIR Te cluster centers can be generated and stabilized in germanate glass and show a broad emission at 770 nm with a full width at half maximum (FWHM) of 260 nm under blue light excitation. By combining the Te-doped glass with a commercial blue LED chip, a high-performance NIR gc-LEDs is fabricated with an NIR output power of 14.21 mW@10.1% under a driving current of 400 mA. Particularly, the fabricated NIR-LED device exhibits high efficient stability with a relatively low-efficiency drop of 0.0023 %mA−1, and excellent aging resistance while retaining an electroluminescence intensity up 90 % of their initial value after aging for 480 h under harsh conditions, which is comparable to the commercial phosphors. Finally, its multifunctional application of gc-LEDs is also demonstrated.

Precisely Regulation of Peripheral Decoration of Multi‐Resonance Molecules and Construction of Highly Efficient Solution‐Processed Orange–Red OLEDs with External Quantum Efficiency Approaching 20%

AbstractThe advent of multi‐resonance thermally activated delayed fluorescence (MR‐TADF) materials, heralding cutting‐edge emitters with superior efficiency and color fidelity, represents a momentous stride in the realm of organic light‐emitting diodes (OLEDs). In this particular investigation, substantial advancements have been made by enhancing, synthesizing, and characterizing three distinct MR‐type emitters through meticulous control of peripheral decorations using frontier molecular orbital engineering. Through strategic attachment of various pyrimidine derivatives to the positions of the lowest unoccupied molecular orbitals (LUMO) of the parent molecule, the molecular excited state attributes are meticulously tailored, leading to the development of orange‐red MR‐TADF emitters. These designed molecules have demonstrated an emission spectrum shift from orange‐red to orange, exhibiting peak wavelengths spanning the range of 585–608 nm and full width at half‐maximums (FWHM) between 36 and 43 nm. This signifies a remarkable precision in managing the emission maxima of MR‐TADF emitters. Astonishingly, the solution‐processed OLEDs have showcased vibrant orange‐red electroluminescence, characterized by peak wavelengths ranging from 587 to 611 nm, accompanied by a notable external quantum efficiency nearing 20%.

A peripheral modification strategy for high performance multi-resonance TADF emitters to construct sensitized OLEDs

Multiple resonance thermally activated delayed fluorescence (MR-TADF) emitters show great application potential in high color purity and high-resolution organic light-emitting diodes (OLEDs) display. However, the high-performance narrowband MR-TADF based OLEDs are still scarce. In this work, two new MR-TADF emitters Me-PABCZ and Me-PABDPA with high photoluminescence quantum yields (PLQYs) of 94.6 % and 91.8 % respectively, are designed and synthesized by a one-shot electrophilic C–H borylation reaction. The full-width at half-maximum (FWHM) values of photoluminescence spectra in the high dispersion state of Me-PABCZ and Me-PABDPA luminogens are 22 nm and 29 nm, respectively. By coating large steric carbazole or diphenylamine units around the multi-resonance core, the intermolecular interactions are suppressed and the aggregation-induced emission quenching effect is inhibited. As a result, the TADF-sensitized TADF (TST) device utilizing Me-PABCZ as sensitizer and Me-PABDPA as emitter achieves a maximum external quantum efficiency (EQE) of 27.9 %. Such a type of light-emitting device exhibits a weak dopant concentration dependence characteristic. The incorporation of molecule conformational engineering and device structural engineering into the MR-TADF technology could usher in a new paradigm of OLEDs.

Role of carbonization parameters on surface and microstructural and crystalline properties of mesoporous coconut shell char: Quantitative and structural study

The present work focuses on the synthesis of inactive mesoporous char using the carbonization method. The experiment was conducted at various conditions using a constant flow of nitrogen gas with variable temperature ramp and carbonization temperature i.e., 5 °C /min to 20 °C /min and 400 °C to 800 °C respectively. The product was identified by calculating its surface area, pore size, micro strain, interplanar spacing, packing density, full-width half maximum, crystallite size, lateral size, no of layers, dislocation density, crystallinity index, and morphological characterization. It was revealed that the best results in terms of surface area, pore size, micropore volume, and burn-off value of the char were observed at a carbonization temperature of 700 °C with a heating rate of 10 °C/min. The calculated values of surface area, pore size, micropore volume, and burn-off were found to be 211.816 m2/g, 2.288 nm, 0.121 cm3/g, and 20.2 % respectively.