Brookhaven Technology Group (United States)

Abstract The formation of long-range ordered phases has long been debated as a potential concern in nuclear power applications. The Ni2Cr phase is known to cause hardening, embrittlement and matrix lattice contraction in Ni-Cr alloys, but the timescale associated with its formation in commercial alloys is unclear. In this study, we isothermally age alloys 690, 625, and 625 plus (625+) at four temperatures, 330, 360, 418, and 475 °C, for up to 50,000 hours. Samples are characterized by synchrotron x-ray diffraction and microhardness. Alloy 690 shows matrix lattice contraction, short range ordering, and a small amount of hardening (~6 %) at 418 and 475 °C, but no long-range ordered peaks after 50k hours due to its high Fe content. Thus, Ni2Cr long-range ordering is sluggish in alloy 690 at LWR-relevant temperatures and further timepoints are needed to quantify its potential formation and effects on mechanical properties. The synchrotron x-ray diffraction patterns do not reveal the long-range ordered Ni2Cr phase in alloy 625 after 50k hrs but significant matrix lattice contraction and noticeable hardening (~28 %) occur at the 475 °C temperature, which saturate after 10k hrs. The synchrotron x-ray diffraction patterns also do not show the long-range ordered Ni2Cr phase in alloy 625+ after 50k hrs, but the matrix and γ” phases gradually contract and harden (~15 %) after 50k hrs at 475 °C, thought to relate to γ’ formation.

ABSTRACTNeural stem cells (NSCs) in the mouse hippocampal dentate gyrus (DG) – a structure important to learning and memory – generate new neurons postnatally and throughout adult life. However, the regulators that enable this lifelong neurogenesis remain incompletely understood. Here we show that the chromatin regulator KDM6B is required for both the establishment and maintenance of NSCs in the mouse DG. Conditional deletion ofKdm6bin embryonic DG precursors results in an adult hippocampus that is essentially devoid of NSCs, and hippocampal-dependent behaviors are defective.Kdm6b-deletion causes precocious neuronal differentiation, and the NSC population fails to become established in the postnatal DG. Using single cell RNA sequencing (scRNA-seq), we observed thatKdm6b-deletion disrupts the transcriptomic signature of NSC maintenance. Furthermore, deletingKdm6bin adult DG NSCs induces early neuronal differentiation, and the NSC population is not properly maintained. These data illustrate the critical role thatKdm6bplays in adult DG neurogenesis, which may help understand how mutations in this chromatin regulator result in cognitive disorders in human patients.

The performance and reliability of magnets made from second generation (2G), exfoliated, YBCO conductors are highly improved by use of narrow, stacked, multifilamentary cable instead of a single wide tape. This paper reports on tests of five mini-coils wound from 2.4 mm wide ExoCable™, which is comprised of eight, stacked, exfoliated, YBCO filaments. The filaments are coupled electrically through a re-flow process, which results in enhanced electrical connectivity between the adjacent layers. The coils were tested at 77 K (up to 500 A) in liquid nitrogen and at 22 K (up to 700 A) in a conduction-cooled mode. The cable carries 500 A critical current at 77 K. A six-layer coil wound from 10.5 m of the cable, the largest coil created in the study, demonstrates a critical current of 280 A at 77 K at 0.4 T magnetic field on the winding. The coils were fully impregnated with Stycast 1266 and Henkel W19 low-viscosity epoxies. Repeated thermal cycling, to 77 and 22 K, does not degrade the coil’s performance. The cable AC loss and the coil winding magnetization are compared with the traditional 2G wide tape pancake geometry at 77 K. We observe a five times reduction of the winding magnetization when the 12 mm tape is replaced by a 2.4 mm cable, which is explained by the smaller magnetic moment of the cable winding. The field hysteresis profiles recorded at 22 and 77 K are presented to demonstrate the effect of the operation temperature on the winding magnetization. A finite element analysis of the winding magnetization shows a good agreement between the experimentally measured trapped field value, and the critical state model prediction. Finally, we discuss the stability of an ExoCable™ coil in a conduction-cooled operation.

Because the incidence rate of renal impairment is 2-10% for patients treated with high-dose methotrexate and renal impairment develops in 0-12.4% of patients treated for osteosarcoma, we sought to evaluate the efficacy of glucarpidase, a recently approved drug that rapidly hydrolyzes methotrexate to inactive metabolites, which allows for nonrenal clearance in patients with delayed renal methotrexate elimination. Pooled analysis of efficacy data from four multicenter single-arm compassionate-use clinical trials using protocols from 1993 to 2007. Of 476 patients with renal toxicity and delayed methotrexate elimination who were treated with intravenous glucarpidase for rescue after high-dose methotrexate, 169 patients had at least one preglucarpidase (baseline) plasma methotrexate concentration greater than 1μmol/L and one postglucarpidase methotrexate concentration measurement by high-performance liquid chromatography and were included in the efficacy analysis; renal recovery was assessed in 436 patients who had at least one recorded preglucarpidase and postglucarpidase serum creatinine concentration measurement. Efficacy was defined as rapid and sustained clinically important reduction (RSCIR) in plasma methotrexate concentration, with a concentration of 1μmol/L or lower at all postglucarpidase determinations. Median age of efficacy-evaluable patients was 20years (range 5weeks-84years). Osteosarcoma (36%), non-Hodgkin lymphoma (27%), and acute lymphoblastic leukemia (20%) were the most frequent underlying diagnoses. Median preglucarpidase serum methotrexate was 11.7μmol/L. At the first (median 15minutes) through the last (median 40hours) postglucarpidase measurement, plasma methotrexate concentrations demonstrated consistent 99% median reduction. RSCIR was achieved by 83 (59%) of 140 patients. A total of 64% of patients with renal impairment greater than or equal to Common Terminology Criteria for Adverse Events grade 2 recovered to grade 0 or 1 at a median of 12.5days after glucarpidase administration. Glucarpidase caused a clinically important 99% or greater sustained reduction of serum methotrexate levels and provided noninvasive rescue from methotrexate toxicity in renally impaired patients.

A solution method was developed to calculate the simultaneous phase and chemical equilibria in high-pressure methanol synthesis (P = 20 MPa, 463 <T <553 K). Algorithms were developed that explicitly consider the existence of a condensed phase and include dew point calculations. A modification of the Soave-Redlich-Kwong equation of state was used to correct for nonideal effects. Binary interaction coefficients were derived from literature data on high-pressure binary vapor liquid equilibria. Predicted equilibrium conversions, with and without formation of a liquid phase, were successfully verified with new experimental results on high-pressure methanol synthesis obtained in a packed bed methanol synthesis reactor. Experimental data coincide very well with model predictions for the equilibrium conversion and gas composition. Remarkably, in some situations the model calculations appeared to predict condensation followed by a disappearing liquid phase (retrograde-like behavior) with increasing extent of the methanol synthesis reactions. Finally, at equilibrium only a gas phase remained present.

紙の最適な物理特性と品質を保証するには，十分に制御された紙の地合いが必要である。紙の地合いを評価するために製紙メーカーは，フロック寸法およびその分布等の紙の地合い情報に加えて，透かし地合い（LT），フロック異方性，周期性マーク及び傾向等の視覚的な制御をしていかなければならない。Techpap社は，先進のビデオ分析技術に基づいた2次元オンライン地合いセンサーを新たに開発したので紹介する。なお，最初の2次元地合いシステムは，1990年台半ばに設置され，その後，世界中の市場で数多く使用されている。

Experimental studies of fundamental structure of nucleons require an electron-ion collider of a center-of- mass energy up to 90 GeV at luminosity up to 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">35</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> s <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> with both beams polarized. A CEBAF-based collider of 9 GeV electrons/positrons and 225 GeV ions is envisioned to meet this science need and as a next step for CEBAF after the planned 12 GeV energy upgrade of the fixed target program. A ring-ring scheme of this collider developed recently takes advantage of the existing polarized electron CW beam from the CEBAF and a green-field design of an ion complex with electron cooling. We present a conceptual design and report design studies of this high-luminosity collider.

We consider the possibilities of developing smart nano-structured coverings that allow one dynamically change their color in the reflected light by modify spectral position of their reflection coefficient. The suggested technology is based on the recent progresses in the field of photonics and the fabrication of silicon-compatible photonic band gap (PBG) materials, photonic crystals. It is suggested to compose the PBG structures of porous silicon and infiltrate them with active nano-compounds whose optical features can be changed by the application of the electric field, current or illumination. As a result, the controlled change of color of the composed structure can be achieved.

In low bit-rate harmonic speech coding, voicing information is often specified by a cut-off frequency of the spectrum. Many approaches of cut-off estimation depend on spectral matching, where a fixed prototype spectrum is used to model voiced harmonics. However, voiced harmonics do not always show a regular shape. One of the causes is harmonic interference. We propose an analysis-by-synthesis voicing cut-off determination scheme that takes into account harmonic interactions in spectral matching. The proposed scheme has been embedded in a 2.4 kb/s harmonic coder. Subjective listening tests show that the scheme performs well and is robust against noise.