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At least 235 records · Page 13

Improvements to sample processing and measurement to enable more widespread environmental application of tritium

Previous measurements have demonstrated the wealth of information that tritium (T) can provide on environmentally relevant processes. We present modifications to sample preparation approaches that enable T measurement by proportional counting on small sample sizes equivalent to 120 mg of water and demonstrate the accuracy of these methods on a suite of standardized water samples. This enhanced method should provide the analytical flexibility needed to address persistent knowledge gaps in our understanding of T behavior in the environment.

low background↗

Ambient Mass Spectrometry Rapid Analysis Methods for Trace Inorganics

The ability to rapidly detect and characterize the chemistry of trace quantities of inorganic species has multiple potential applications, including nuclear safeguards, nuclear forensics, and environmental monitoring. Some mass spectrometric methods currently exist, but they are costly and time-intensive, often destroying chemical information in the process of ionization. Ambient mass spectrometry is a relatively new analytical method in which samples are introduced to the mass spectrometer from atmospheric pressure, rather than from high vacuum. Ambient MS can operate with gentler ionization methods such as electrospray ionization (ESI) and paper-spray ionization (PSI), reducing fragmentation and preserving the chemical information of the analyte. This may be useful for determining the intended purpose of material in a sample. Strontium, part of nuclear fallout, is analyzed here to test these new analytical methods for viability. Electrospray ionization mass spectrometry functions by spraying the sample as a solution through a needle charged to a few kV. A nebulizing gas flows out along with the sample to create the spray before droplets enter a drying chamber with heated drying gas to remove the solvent molecules. From there bare analyte ions enter the mass spectrometer. This method has the advantage of relatively fast sample preparation and stable ionization. More stable ionization produces higher-quality data. Paper-spray ionization mass spectrometry operates by applying sample to a paper triangle. The paper triangle is then electrified in a metal clamp to a few kV before spray solvent is applied. The spray solvent transports analyte in the sample to the tip, where it is ionized and enters the mass spectrometer. One advantage of this method is reduced sample preparation - an analyst can even swipe a surface and cut a triangle directly from the swipe. The data analysis serves to rapidly process tens of samples all at once. The mass spectrometer outputs a file containing a few hundred spectra for each sample. The pipeline processes each one to identify peaks of interest. A full palette of data analysis metrics are generated, including plots of the raw data and plots of calculated values such as isotopic ratios. The pipeline filters the raw data to remove noise and background peaks, as well as peaks representing detector saturation. A heat map is generated to show the overall spectrum in mass-time- intensity space. Post-processing, we obtained the desired calibration curves, demonstrating that both ESI-MS and PSI-MS are viable methods for quantifying trace amounts of inorganics while retaining their chemical speciation information. ESI-MS demonstrated a linear response region of 100 ppb to 20 ppm, with a limit-of-detection of around 100 ppb. At top left is an example spectrum with the {sup 88}SrNO{sub 3} peak identified to show the retention of chemical speciation. PSI-MS showed a linear response region of around 1 ppb to 1 ppm, with a limit-of-detection of near 1 ppb. PSI-MS produced more erratic results than ESI-MS, likely due to the variability in ionization resulting from manual positioning of the paper triangle near the MS inlet. Future efforts will focus on improving the repeatability of PSI-MS as well as analyzing other species of interest such as cerium and uranium. Improvements will also be made to create more reliable data extraction and intelligent data filtering.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Rapid Assessment of Contaminants and Interferences in Mass Spectrometry Data Using Skyline

Proper sample preparation in proteomic workflows is essential to the success of modern mass spectrometry experiments. Complex workflows often require reagents which are incompatible with MS analysis (e.g., detergents) necessitating a variety of sample cleanup procedures. Efforts to understand and mitigate sample contamination are a continual source of disruption with respect to both time and resources. To improve the ability to rapidly assess sample contamination from a diverse array of sources, I developed a molecular library in Skyline for rapid extraction of contaminant precursor signals using MS1 filtering. This contaminant template library is easily managed and can be modified for a diverse array of mass spectrometry sample preparation workflows. Utilization of this template allows rapid assessment of sample integrity and indicates potential sources of contamination. .

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Electrodeposition as an alternate method for preparation of environmental samples for iodide by AMS

This paper presents an evaluation of an alternate method for preparing environmental samples for 129 I analysis by accelerator mass spectrometry (AMS) at Idaho National Laboratory. The optimal sample preparation method is characterized by ease of preparation, capability of processing very small quantities of iodide, and ease of loading into a cathode. Electrodeposition of iodide on a silver wire was evaluated using these criteria. This study indicates that the electrochemically-formed silver iodide deposits produce ion currents similar to those from precipitated silver iodide for the same sample mass. Furthermore, precipitated silver iodide samples are usually mixed with niobium or silver powder prior to loading in a cathode. Using electrodeposition, the silver is already mixed with the sample and can simply be picked up with tweezers, placed in the sample die, and pressed into a cathode. The major advantage of this method is that the silver wire/electrodeposited silver iodide is much easier to load into a cathode.

129I↗

Luminescence switching in Ce{sup 3+} ion sensitized YPO{sub 4}:Tb{sup 3+} through Redox reaction

Highlights: • Simple polyol method for preparation of Ce{sup 3+} sensitized Tb{sup 3+} ion doped YPO{sub 4} nanophosphor. • Enhanced green color emission with incorporation of Ce{sup 3+} ion into the matrix of YPO{sub 4}:Tb{sup 3+} nanophosphor. • Highly crystalline tetragonal YPO{sub 4}:Tb{sup 3+} without any impurity phase. • Use of alternate oxidising and reducing agent for luminescence switching (ON and OFF). - Abstract: Ce{sup 3+} sensitized Tb{sup 3+} ion doped YPO{sub 4} nanophosphor is synthesized by simple polyol method using ethylene glycol as capping agent as well as reaction medium. Green emission from Tb{sup 3+} ion doped YPO{sub 4} nanophosphor has been enhanced with incorporation of Ce{sup 3+} ion into the matrix of YPO{sub 4}:Tb{sup 3+}. XRD of YPO{sub 4}:Tb{sup 3+} annealed at 900 °C reveals crystalline tetragonal structure without any impurity phase. Morphology of YPO{sub 4}:Tb{sup 3+} nanophosphor was also studied. Homogenous incorporation of rare earth, RE (RE = Tb{sup 3+}, Ce{sup 3+}) ion into the host matrix were given in EDAX spectra. TGA/DTA analysis shows phase transformation of the as-prepared sample. Also, it is found that the as-prepared sample were readily re-dispersible in water due to presence of −OH group. By using an alternate oxidising and reducing agent, behaviour of luminescence switching (ON and OFF) can be examined. Lifetime decay of Tb{sup 3+} ion doped YPO{sub 4} nanophosphor was also studied.

36 MATERIALS SCIENCE↗

Study of synergistic effects and compositional dependence of hydrogen evolution reaction on MoxNiy alloy thin films in alkaline media

In this paper hydrogen evolution reaction (HER) on the molybdenum-nickel thin films has been studied. The Mo x Ni y thin films were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). A change in the crystal structure of the samples prepared at different temperatures was observed. The structure of the samples prepared at 25 °C are bcc or amorphous. The structure of alloys sputtered at 800 °C changed to fcc. Tafel plots were constructed for each Mo x Ni y alloy sample. The mechanism of HER was determined from Tafel slope analysis. Values of charge transfer resistance were also determined by impedance spectroscopy. The compositional dependence of activity and the stability of Mo x Ni y thin films in 1 M NaOH were determined by cycling and chronoamperometry. Our results demonstrate that Mo x Ni y thin films prepared at 800 °C show significantly improved activity compared to pure Mo and Ni metals. On the other hand, Mo x Ni y thin films sputtered at 25°C do not show increased activity in comparison to pure Ni metal. Furthermore, this points to a synergistic effect between fcc Mo and fcc Ni in thin films sputtered at elevated temperatures. Mo 63 Ni 67 thin films alloy prepared at 800 °C shows the best values of catalytic activity for HER from all investigated compositions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Integrative Multi-PTM Proteomics Reveals Dynamic Global, Redox, Phosphorylation, and Acetylation Regulation in Cytokine-treated Pancreatic Beta Cells

Studying regulation of protein function at a systems level necessitates an understanding of the interplay among diverse post-translational modifications (PTMs). A variety of proteomics sample processing workflows are currently used to study specific PTMs but rarely characterize multiple types of PTMs from the same sample inputs. Method incompatibilities and laborious sample preparation steps complicate large-scale physiological investigations and can lead to variations in results. The single-pot, solid-phase-enhanced sample preparation (SP3) method for sample cleanup is compatible with different lysis buffers and amenable to automation, making it attractive for high-throughput multi-PTM profiling. Herein, we describe an integrative SP3 workflow for multiplexed quantification of protein abundance, cysteine thiol oxidation, phosphorylation, and acetylation. The broad applicability of this approach is demonstrated using cell and tissue samples, and its utility for studying interacting regulatory networks is highlighted in a time-course experiment of cytokine-treated ß-cells. We observed a swift response in global regulation of protein abundances consistent with rapid activation of JAK-STAT and NF-?B signaling pathways. Regulators of these pathways as well as proteins involved in their target processes displayed multi-PTM dynamics indicative of a complex cellular response stages: acute, adaptation, and chronic (prolonged stress). PARP14, a negative regulator of JAK-STAT, had multiple co-localized PTMs that may be involved in intraprotein regulatory crosstalk. Our workflow provides a high-throughput platform that can profile multi-PTMomes from the same sample set, which is valuable in unraveling the functional roles of PTMs and their co-regulation.

proteomics, PTM, automation, SP3, cysteine thiol o↗

Luminescent nanocrystals in the rare-earth niobate–zirconia system formed via hydrothermal method

Luminescent nanocrystals based on the rare-earth niobates (Ln{sub 3}NbO{sub 7}, Ln=Y, Eu) and zirconia (ZrO{sub 2}) that were composed of 50 mol% Ln{sub 3}NbO{sub 7} and 50 mol% ZrO{sub 2}, were hydrothermally formed as cubic phase under weakly basic conditions at 240 °C. The lattice parameter of the as-prepared nanoparticles corresponding to the composition of Y{sub 3−x}Eu{sub x}NbO{sub 7}–4ZrO{sub 2} that was estimated as a single phase of cubic gradually increased as the content of europium x increased. The existence of small absorbance peaks at 395 and 466 nm corresponding to the Eu{sup 3+7}F{sub 0}→{sup 5}L{sub 6}, and {sup 7}F{sub 0}→{sup 5}D{sub 2} excitation transition, respectively, was clearly observed in the diffuse reflectance spectra of the as-prepared samples containing europium. The optical band gap of the as-prepared samples was in the range from 3.5 to 3.7 eV. The photoluminescence spectra of the as-prepared nanocrystals containing europium showed orange and red luminescences with main peaks at 590 and 610 nm, corresponding to {sup 5}D{sub 0}→{sup 7}F{sub 1} and {sup 5}D{sub 0}→{sup 7}F{sub 2} transitions of Eu{sup 3+}, respectively, under excitation at 395 nm Xe lamp. The emission intensity corresponding to {sup 5}D{sub 0}→{sup 7}F{sub 2} transition increased as heat-treatment temperature rose from 800 to 1200 °C. - Graphical abstract: This graphical abstract shows the excitation and emission spectra and a transmission electron microscopy image of nanocrystals (with composition based on the rare-earth niobates (Ln{sub 3}NbO{sub 7}, Ln=Y, Eu) and zirconia (ZrO{sub 2}) that were composed of 50 mol% Ln{sub 3}NbO{sub 7} and 50 mol% ZrO{sub 2}) formed via hydrothermal route. Display Omitted - Highlights: • Nanocrystals composed of 50 mol% Y{sub 3−x}Eu{sub x}NbO{sub 7} and 50 mol% ZrO{sub 2} was directly formed. • The nanocrystals were hydrothermally formed under weakly basic conditions at 240 °C. • The Y{sub 3}NbO{sub 7} showed an UV-blue and broad-band emission under excitation at 240 nm. • The emission is originated from the niobate octahedral group [NbO{sub 6}]{sup 7−}. • The nanocrystals showed orange and red luminescences ({sup 5}D{sub 0}→{sup 7}F{sub 1} and {sup 5}D{sub 0}→{sup 7}F{sub 2} , Eu{sup 3+})

36 MATERIALS SCIENCE↗

Ultra-Microtome for the Preparation of TEM Samples from Battery Cathodes

An ultra-microtome method is developed for the preparation of transmission electron microscopy (TEM) specimens from the cathodes of Li-ion battery. Results indicate that the samples prepared with the ultra-microtome method yield atomic resolution imaging from the core area of particles of hundreds to thousands of nanometers. Analysis of the TEM samples prepared with ultra-microtome indicates that no observable structural damage, such as microcracking, is introduced during the cutting process, and the cathodes cut by ultra-microtome exhibit unchanged micro-morphologies compared with the uncut ones. These results demonstrate that ultra-microtome is a promising method for the preparation of TEM specimens and revealing in-depth microstructures of fragile materials such as battery cathodes.

transmission electron microscopy, Sample Preparati↗

Data Trend Shifts Induced by Method of Concentration for Trace Metals in Seawater: Automated Online Preconcentration vs Borohydride Reductive Coprecipitation of Nearshore Seawater Samples for Analysis of Ni, Cu, Zn, Cd, and Pb via ICP-MS

This research compares performance, reproducibility, and detection limits of ambient seawater analysis for trace metals using both borohydride reductive co-precipitation and an automated chelation column (seaFAST™ 2) co-preconcentration for matrix interferent elimination on total and dissolved grab samples in nearshore to marine waters, over a broad concentration range, prior to ICP-MS injection. A move to an online preconcentration method both minimizes sample preparation, and eliminates correction errors when accounting for trace impurities in precipitated samples, induced via reagents. The reproducability of the online preconcentration method described, coupled with low blanks and method detection limits (MDLs), demonstrates an effective move to an automated procedure using ethylenediaminetriacetic and iminodiacetate acid chelation exchange resin and multi-analyte determination via ICP-MS for total and dissolved Ni, Cu, Zn, Cd, and Pb in marine water samples. Average CASS-5 recoveries using the online preconcentration method (n=9) were 109±7%, 104±5%, 103±7%, 101±3%, and 86±8% respectively. The MDLs obtained from the automated method for Ni, Cu, Zn, Cd and Pb were 3.3, 1.8, 13.5, 4, and 10 times lower, respectively, than for the Borohydride method. There were statistically significant differences between the methods for CASS-5 recoveries of Ni, Cu, Zn (p < 0.0001), and Pb (p = 0.0024). Comparison of methods gave high concordance (rC = 0.90) between methods for total and dissolved Ni, Cu, Zn, and Pb, and total Cd.

seaFAST, borohydride, seawater, Ethylenediaminetet↗

Effect of ultrasound treatment on the morpho-structural and luminescent characteristics of cerium doped yttrium silicate phosphors

Highlights: • Y{sub 2}SiO{sub 5}:Ce is prepared by gel combustion in ultrasound conditions (US). • Morpho-structural characteristics are revealed based on FTIR, SEM, XRD, BET. • Incorporation of Ce{sup 3+} in X1/X2 type centers depends on preparative conditions. • US treatment increases the luminescent performances up to 151%. - Abstract: Cerium activated yttrium silicate (Y{sub 2}SiO{sub 5}:Ce) phosphors were prepared by gel-combustion, using yttrium–cerium nitrate as oxidizer, aspartic acid as fuel and TEOS as source of silicon. Two modalities for samples preparation were approached namely: the classical gel-combustion and sonication gel-combustion. The ultrasound treatment during the gelling stage has a positive effect on the structural and luminescent characteristics of the final product. Therefore, a well crystallized single X2–Y{sub 2}SiO{sub 5} phase phosphor was obtained at 1200 °C. Based on FT-IR and XRD investigations, conversion of X1 to X2–Y{sub 2}SiO{sub 5} phases is observed as the firing temperature is varied (1100 °C, 1200 °C, 1300 °C 1400 °C). The ultrasound treatment leads to smaller particle size and enhances the luminescent performances up to 151% in comparison with samples prepared by classical way.

36 MATERIALS SCIENCE↗

Strongly extended diffusion length for the nonequilibrium magnons in Y 3 F e 5 O 12 by photoexcitation

Y 3 Fe 5 O 12 (YIG) is known for its long magnon diffusion length. Although it has the known lowest damping rate, an even longer diffusion distance is still highly desired since it may lead to a much more efficient information transmission and processing. While most of previous works focused on the generation and detection of magnons in YIG, here we demonstrate how to depress the damping rate during the diffusion of magnon. By selectively exciting the spin state transition of the Fe ions in YIG, we successfully increase magnon diffusion length by one order of magnitude, i.e., from the previous reported ~10 μm up to ~156 μm (for the sample prepared by liquid phase epitaxy) and ~180 μm (for the sample prepared by pulsed laser deposition) at room temperature. The diffusion length, determined by nonlocal geometry, is ~30 μm for the magnons induced by visible light and above 150 μm for the laser of 980 nm. In addition to thermal gradient, light excitation affects the electron configuration of the Fe 3+ ion in YIG. Long-wavelength laser is more effective since it causes a transition of the Fe 3+ ions in FeO 6 octahedron from a high spin to a low spin state and thus causes a magnon softening which favors a long-distance diffusion. Furthermore, the present work paves the way toward an efficient tuning of magnon transport which is crucially important for magnon spintronics.

36 MATERIALS SCIENCE↗

New experimental perspectives for soft x-ray absorption spectroscopies at ultra-low temperatures below 50 mK and in high magnetic fields up to 7 T

A new ultra-low temperature experiment including a superconducting vector magnet has been developed for soft x-ray absorption spectroscopy experiments at third generation synchrotron light sources. The sample is cooled below 50 mK by a cryogen free {sup 3}He-{sup 4}He dilution refrigerator. At the same time, magnetic fields of up to ±7 T in the horizontal direction and ±0.5 T in the vertical direction can be applied by a superconducting vector magnet. The setup allows to study ex situ and in situ prepared samples, offered by an attached UHV preparation chamber with load lock. The transfer of the prepared samples between the preparation section and the dilution refrigerator is carried out under cryogenic temperatures. First commissioning studies have been carried out at the Variable Polarization XUV Beamline P04 at PETRA III and the influence of the incident photon beam to the sample temperature has been studied.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

The Grain Boundary Relaxation (GBR) Approach for Manufacturing High Strength Nanocrystalline Lightweight Metals

The overarching goal of the project was to conduct research and development work as proposed in the Statement of Project Objective (SOPO) of the award document DE-FE-0009116. The project had 4 tasks and 12 milestones. All the milestone deliverables were completed. The accomplishments of the project objectives and technical discussions are described in Sections 3 and 4, respectively. The modeling and simulation work indicated that to increase the strength and stability of nanocrystalline aluminum (Al), selection of dopants, such as Mg, is necessary. It was predicted that the crystallite size should be less than 50 nm to give high strength. On the basis of modeling, cryo-milling of Al was conducted with the addition of Mg as a function of different times. The crystallite size of the cryo-milled powders was determined by XRD and TEM. Both measurements showed that the actual crystallite size of the grain was <40 nm. The thermal stability of the grain size was established as a function of temperature. It was established that the grain size was < 50 nm up to 500C. The crystallite size of the bulk sample prepared by spark plasma sintering (SPS) and cold spray (CS) additive manufacturing was less than <40 nm. The mechanical properties of the bulk samples prepared by SPS and CS, showed excellent microhardness, good tensile properties (>200 MPa) with moderate ductility and improved fatigue performance. Adding yttria stabilized zirconia (YSZ) improved the build thick of the CS sample, however the YSZ was getting embedded into the sample. A highly dense SPS samples sent for 3rd party testing to the Innovation Testing Services showed a minimum hardness of 180 HV with an average tensile strength of 512.5 MPa. The high cycle fatigue tests also showed an endurance limit of 179.5 MPa. The Energy cost evaluations showed an overall energy cost of around $\$$17.05 for the cryomilling and SPS processes and the total manufacturing cost calculations of $\$$78.14 for 1 kg of sample. The energy cost to prepare a Kg of CS sample is $\$$17.60 and the overall manufacturing cost is $\$$86.85.

36 MATERIALS SCIENCE↗

Spatially-Resolved Proteomics: Rapid Quantitative Analysis of Laser Capture Microdissected Alveolar Tissue Samples

Global proteomics approaches allow characterization of whole tissue lysates to an impressive depth. However, it is now increasingly recognized that to better understand the complexity of multicellular organisms, global protein profiling of specific spatially defined regions/substructures of tissues (i.e. spatially-resolved proteomics) is essential. Laser capture microdissection (LCM) enables microscopic isolation of defined regions of tissues preserving crucial spatial information. However, current proteomics workflows entail several manual sample preparation steps and are challenged by the microscopic mass-limited samples generated by LCM, and that impact measurement robustness, quantification, and throughput. Here, we coupled LCM with a fully automated sample preparation workflow that with a single manual step allows: protein extraction, tryptic digestion, peptide cleanup and LC-MS/MS analysis of proteomes from microdissected tissues. Benchmarking against the current state of the art in ultrasensitive global proteomic analysis, our approach demonstrated significant improvements in quantification and throughput. Using our LCM-SNaPP proteomics approach, we characterized to a depth of more than 3,400 proteins, the ontogeny of protein changes during normal lung development in laser capture microdissected alveolar tissue containing ~4,000 cells per sample. Importantly, the data revealed quantitative changes for 350 low abundance transcription factors and signaling molecules, confirming earlier transcript-level observations and defining seven modules of coordinated transcription factor/signaling molecule expression patterns, suggesting that a complex network of temporal regulatory control directs normal lung development with epigenetic regulation fine-tuning pre-natal developmental processes. Furthermore, our LCM-proteomics approach facilitates efficient, spatially-resolved, ultrasensitive global proteomics analyses in high-throughput that will be enabling for several clinical and biological applications.

60 APPLIED LIFE SCIENCES↗

X-Ray Fluorescence Quantitative and Qualitative Analysis Using Micro Glass Beads

The fused glass bead method is the accepted 'best practice' method of preparation of samples for X-ray fluorescence (XRF) analysis. It minimizes the effects of sample heterogeneity and simplifies calibration by dissolving the sample into a uniform glass matrix. Glass fusion XRF samples are typically prepared by grinding sample powder with Lithium Tetraborate / Lithium Bromide and fusing the mixture at 1000 deg. C. In most cases sample-to-flux ratios of between 1:1 to 1:10 are used (1:1 for determination of trace elements and 1:10 for major elements). Typical sample mass consumed is in the range of 1000 to 2500 mg. It would be advantageous to reduce this sample mass in cases where the sample material is rare, valuable or highly radioactive. This study examines the effects of using lower sample-to-flux ratios and smaller fusion bead size on the detection and quantification of major and trace elements by XRF analysis. We have employed a micro fused glass bead process, using sample-to-flux ratios of 1:10, 1:15 and 1:25, to determine the effects on measurement precision, accuracy and detection limit. Objectives: - Created micro fused glass beads of a series of standards and andesite sample with sample-to-flux ratios of 1:10, 1:15 and 1:25. - Perform an qualitative analysis of the different sample-to-flux ratio micro beads and compare the results with the 1:5.3 beads routinely used at SRNL. - Quantitate the major components in the different sample-to-flux ratio micro beads using a wavelength dispersive x-ray fluorescence instrument. Advantages: - Reduce sample amount needed. - Speed up waste tank characterization. - Reduce personnel exposure. - Potential sealed source. Fused micro glass beads with sample-to-flux ratios of 1:10, 1:15 and 1:25 were created using sample amounts of 123 mg, 82 mg and 52 mg respectively. It was possible to detect most of the major oxides and some trace elements in the fused micro glass beads with different sample-to-flux ratios. The quantitative analysis showed good linear correlation between the intensity of the analysis and the concentration of the elements. Good precision and accuracy results were obtained for the majority of the major oxides in the three fused micro glass beads with different sample-to-flux ratios. Path Forward: Enhance the precision and accuracy of the method by optimizing different sample preparation steps, such as weighing and sample transfer. Continue to increase the sample-to-flux ratio to determine the minimum amount of sample needed to perform a multielement analysis. Consider the use of synthetic standards to lower the detection limit of the analysis. Used the micro bead sample preparation method to analyze radioactive samples.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗