5,620 research outputs found

    Three-Dimensional Magnetic Page Memory

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    The increasing need to store large amounts of information with an ultra-dense, reliable, low power and low cost memory device is driving aggressive efforts to improve upon current perpendicular magnetic recording technology. However, the difficulties in fabricating small grain recording media while maintaining thermal stability and a high signal-to-noise ratio motivate development of alternative methods, such as the patterning of magnetic nano-islands and utilizing energy-assist for future applications. In addition, both from sensor and memory perspective three-dimensional spintronic devices are highly desirable to overcome the restrictions on the functionality in the planar structures. Here we demonstrate a three-dimensional magnetic-memory (magnetic page memory) based on thermally assisted and stray-field induced transfer of domains in a vertical stack of magnetic nanowires with perpendicular anisotropy. Using spin-torque induced domain shifting in such a device with periodic pinning sites provides additional degrees of freedom by allowing lateral information flow to realize truly three-dimensional integration

    What Scanners do at L7? Exploring Horizontal Honeypots for Security Monitoring

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    Honeypots are a common means to collect data useful for threat intelligence. Most efforts in this area rely on vertical systems and target a specific scenario or service to analyse data collected in such deployment. We here extend the analysis of the visibility of honeypots, by revisiting the problem from a horizontal perspective. We deploy a flexible honeypot system hosting multiple services, relying on the T-Pot project. We collect data for 5 months, recording millions of application requests from tens of thousands of sources. We compare if and how the attackers interact with multiple services. We observe attackers that always focus on one or few services, and others that target tens of services simultaneously. We dig further into the dataset, providing an initial horizontal analysis of brute-force attacks against multiple services. We show, for example, clear groups of attackers that rely on different password lists on different services. All in all, this work is our initial effort to build a horizontal system that can provide insights on attacks

    Three Endocrine Neoplasms: An Unusual Combination of Pheochromocytoma, Pituitary Adenoma, and Papillary Thyroid Carcinoma

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    Background: Three endocrine neoplasms?bilateral pheochromocytomas, somatotrophic pituitary adenoma inducing acromegaly, and papillary carcinoma of the thyroid?occurred concurrently in a patient. A genetic mutation was hypothesized. Possible previously described genetic mutations were explored. Methods: Clinical assessments, laboratory data, images of tumors, histopathology, and immunohistochemistry of excised tissues documented the three neoplasms. Clinical assessment of the patient, family history, and a review of the literature sought a familial basis for the disorders. Results: The methods confirmed the presence of three endocrine neoplasms. Each neoplasm was surgically excised and histologically verified. Surgical and 131I treatments reduced the papillary carcinoma, but eventually this tumor progressed to a lethal degree. History, including that of nine siblings, uncovered no familial neoplasms. No similar case was found in the literature, but possible associations with germline mutations were considered. Conclusions: The concurrent development of pheochromocytomas, pituitary somatotrophic adenoma, and papillary thyroid carcinoma appears to be unique. Nevertheless, such tumors, particularly bilateral pheochromocytomas, strongly suggest a de novo germline mutation in a gene not previously associated with multiple endocrine neoplasia syndromes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98488/1/thy%2E2011%2E0345.pd

    Following Bimolecular Excited-State Proton Transfer between Hydroxycoumarin and Imidazole Derivatives

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    The ultrafast dynamics of a bimolecular excited-state proton transfer (ESPT) reaction between the photoacid 7-hydroxy-4-(trifluoromethyl)-1-coumarin (CouOH) and 1-methylimidazole (MI) base in aprotic chloroform-d1 solution were investigated using ultrafast transient infrared (TRIR) and transient absorption (TA) spectroscopies. The excited-state lifetime of the photoacid in solution is relatively short (52 ps), which at the millimolar photoacid and base concentrations used in our study precludes any diffusion-controlled bimolecular ESPT reactions. This allows the prompt ESPT reaction between hydrogen-bonded CouOH and MI molecules to be studied in isolation and the “contact” ESPT dynamics to be unambiguously determined. Our time-resolved studies reveal that ultrafast ESPT from the CouOH moiety to hydrogen-bonded MI molecules occurs within ∼1 ps, tracked by unequivocal spectroscopic signatures of CouO–* photoproducts that are formed in tandem with HMI+. Some of the ESPT photoproducts subsequently π-stack to form exciplexes on a ∼35 ps time scale, minimizing the attractive Coulombic forces between the oppositely charged aromatic molecules. For the concentrations of CouOH and MI used in our study (up to 8 mM), we saw no evidence for excited-state tautomerization of coumarin anions

    Review of Alpha-Ketoglutaric Acid (AKGA) Hydrazine and Monomethylhydrazine (MMH) Neutralizing Compound

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    The Johnson Space Center (JSC) White Sands Test Facility (WSTF) and NASA Engineering and Safety Center (NESC) were requested by NASA Associate Administrator for Space Operations to perform an evaluation of a proposed hydrazine/monomethylhydrazine (MMH) fuel treatment method using alpha-ketoglutaric acid (AKGA). This evaluation request was prompted by preliminary tests at the Kennedy Space Center (KSC), suggesting cost and operational benefits to NASA for the Space Shuttle Program (SSP) and other hardware decontamination and decommissioning, in addition to hydrazine and MMH waste treatment activities. This paper provides the team's position on the current KSC and New Mexico Highlands University (NMHU) efforts toward implementing the AKGA treatment technology with flight hardware, ground support equipment (GSE), hydrazine and MMH spills, and vapor control. This evaluation is current to the last data examined (approximately September 2008)
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