392 research outputs found
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Estimation of Maximum Wall Thickness Loss of Five DSTs (AN-107, AP-102, AW-101, AZ-102, and SY-101)
The DST Integrity Plan requires the ultrasonic wall thickness measurement of two vertical scans of the tank primary wall from a single riser. The resulting measurements are then used in an extreme value methodology to predict the minimum wall thickness expected for the entire tank. The methodology was developed in previous work by the authors of this report. A component of the methodology is to consider the possible impact of riser differences had multiple risers instead been used. The approach is based on previous analyses of Tank AY-101 which had measurements taken from multiple risers. This report presents estimated maximum wall thickness loss for five DST's with associated uncertainty estimation and confidence bounds. Several sources of variability are incorporated since the individual sources cannot be separated. These sources include original manufacturing plate thickness and the precision of the measurement process, as well as loss due to corrosion, the actual feature of interest
Potential and distribution of transplanted hematopoietic stem cells in a nonablated mouse model
Increasingly, allogeneic and even more often autologous bone marrow transplants are being done to correct a wide variety of diseases. In addition, autologous marrow transplants potentially provide an opportune means of delivering genes in transfected, engrafting stem cells. However, despite its widespread clinical use and promising gene therapy applications, relatively little is known about the mechanisms of engraftment in marrow transplant recipients. This is especially so in the nonablated recipient setting. Our data show that purified lineage negative rhodamine 123/Hoechst 33342 dull transplanted hematopoietic stem cells engraft into the marrow of nonablated syngeneic recipients. These cells have multilineage potential, and maintain a distinct subpopulation with stem cell characteristics. The data also suggests a spatial localization of stem cell niches to the endosteal surface, with all donor cells having a high spatial affinity to this area. However, the level of stem cell engraftment observed following a transplant of stem cells was significantly lower than that expected following a transplant of the same number of unseparated marrow cells from which the purified cells were derived, suggesting the existence of a nonstem cell facilitator population, which is required in a nonablated syngeneic transplant setting
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Ultrasonic Examination of Double-Shell Tank 241-AN-102 Examination Completed July 2008.
AREVA Federal Services LLC (AFS), under a contract from CH2M Hill Hanford Group (CH2M Hill), has performed an ultrasonic examination of selected portions of Double-Shell Tank 241-AN-102. PNNL is responsible for preparing a report(s) that describes the results of the AFS ultrasonic examinations
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Ultrasonic Examination of Double-Shell Tank 241-AP-107 Examination Completed February 2008
AREVA Federal Services LLC (AFS), under a contract from CH2M HILL Hanford Group (CH2M HILL), has performed an ultrasonic examination of selected portions of Double-Shell Tank 241-AP-107. The purpose of this examination was to provide information that could be used to evaluate the integrity of the wall of the primary tank. The requirements for the ultrasonic examination of Tank 241-AP-107 were to detect, characterize (identify, size, and locate), and record measurements made of any wall thinning, pitting, or cracks that might be present in the wall of the primary tank. Any measurements that exceed the requirements set forth in the Engineering Task Plan (ETP), RPP-Plan-34301 (Castleberry 2007) and summarized on page 1 of this document, are to be reported to CH2M HILL and the Pacific Northwest National Laboratory (PNNL) for further evaluation. Under the contract with CH2M HILL, all data is to be recorded on electronic media and paper copies of all measurements are provided to PNNL for third-party evaluation. PNNL is responsible for preparing a report(s) that describes the results of the AFS ultrasonic examinations
Cells Capable of Bone Production Engraft from Whole Bone Marrow Transplants in Nonablated Mice
Allogeneic and autologous marrow transplants are routinely used to correct a wide variety of diseases. In addition, autologous marrow transplants potentially provide opportune means of delivering genes in transfected, engrafting stem cells. However, relatively little is known about the mechanisms of engraftment in transplant recipients, especially in the nonablated setting and with regard to cells not of hemopoietic origin. In particular, this includes stromal cells and progenitors of the osteoblastic lineage. We have demonstrated for the first time that a whole bone marrow transplant contains cells that engraft and become competent osteoblasts capable of producing bone matrix. This was done at the individual cell level in situ, with significant numbers of donor cells being detected by fluorescence in situ hybridization in whole femoral sections. Engrafted cells were functionally active as osteoblasts producing bone before being encapsulated within the bone lacunae and terminally differentiating into osteocytes. Transplanted cells were also detected as flattened bone lining cells on the periosteal bone surface
Quantum Eavesdropping without Interception: An Attack Exploiting the Dead Time of Single Photon Detectors
The security of quantum key distribution (QKD) can easily be obscured if the
eavesdropper can utilize technical imperfections of the actual implementation.
Here we describe and experimentally demonstrate a very simple but highly
effective attack which even does not need to intercept the quantum channel at
all. Only by exploiting the dead time effect of single photon detectors the
eavesdropper is able to gain (asymptotically) full information about the
generated keys without being detected by state-of-the-art QKD protocols. In our
experiment, the eavesdropper inferred up to 98.8% of the key correctly, without
increasing the bit error rate between Alice and Bob significantly. Yet, we find
an evenly simple and effective countermeasure to inhibit this and similar
attacks
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