Acceleration Of Protons To Above 6 MeV Using H2O >Snow> Nanowire Targets

A scheme is presented for using H2O >snow> nanowire targets for the generation of fast protons. This novel method may relax the requirements for very high laser intensities, thus reducing the size and cost of laser based ion acceleration system.Physic

Probabilistic modeling of noise transfer characteristics in digital circuits

Device scaling, the driving force of CMOS technology, led to continuous decrease in the energy level representing logic states. The resulting small noise margins in combination with increasing problems regarding the supply voltage stability and process variability creates a design conflict between efficiency and reliability. This conflict is expected to rise more in future technologies. Current research approaches on fault-tolerance architectures and countermeasures at circuit level, unfortunately, cause a significant area and energy penalty without guaranteeing absence of errors. To overcome this problem, it seems to be attractive to tolerate bit errors at circuit level and employ error handling methods at higher system levels. To do this, an estimate of the bit error rate (BER) at circuit level is necessary. Due to the size of the circuits, Monte Carlo simulation suffers from impractical runtimes. Therefore the needed modeling scheme is proposed. The model allows a probabilistic estimation of error rates at circuit level taking into account statistical effects ranging from supply noise and electromagnetic coupling to process variability within reasonable runtimes

5.5-7.5 MeV Proton generation by a moderate intensity ultra-short laser interaction with H2O nano-wire targets

We report on the first generation of 5.5-7.5 MeV protons by a moderate intensity short-pulse laser (4.5 \times 1017 W/cm^2, 50 fsec) interacting with H2O nano-wires (snow) deposited on a Sapphire substrate. In this setup, the laser intensity is locally enhanced by the tip of the snow nano-wire, leading to high spatial gradients. Accordingly, the plasma near the tip is subject to enhanced ponderomotive potential, and confined charge separation is obtained. Electrostatic fields of extremely high intensities are produced over the short scale length, and protons are accelerated to MeV-level energies.Comment: submitted to PRL, under press embargo. 6 figure

Characterization and evolution of cell division and cell wall synthesis genes in the bacterial phyla Verrucomicrobia, Lentisphaerae, Chlamydiae and Planctomycetes and phylogenetic comparison with rRNA genes

In the past, studies on the relationships of the bacterial phyla Planctomycetes, Chlamydiae, Lentisphaerae, and Verrucomicrobia using different phylogenetic markers have been controversial. Investigations based on 16S rRNA sequence analyses suggested a relationship of the four phyla, showing the branching order Planctomycetes, Chlamydiae, Verrucomicrobia/Lentisphaerae. Phylogenetic analyses of 23S rRNA genes in this study also support a monophyletic grouping and their branching order—this grouping is significant for understanding cell division, since the major bacterial cell division protein FtsZ is absent from members of two of the phyla Chlamydiae and Planctomycetes. In Verrucomicrobia, knowledge about cell division is mainly restricted to the recent report of ftsZ in the closely related genera Prosthecobacter and Verrucomicrobium. In this study, genes of the conserved division and cell wall (dcw) cluster (ddl, ftsQ, ftsA, and ftsZ) were characterized in all verrucomicrobial subdivisions (1 to 4) with cultivable representatives (1 to 4). Sequence analyses and transcriptional analyses in Verrucomicrobia and genome data analyses in Lentisphaerae suggested that cell division is based on FtsZ in all verrucomicrobial subdivisions and possibly also in the sister phylum Lentisphaerae. Comprehensive sequence analyses of available genome data for representatives of Verrucomicrobia, Lentisphaerae, Chlamydiae, and Planctomycetes strongly indicate that their last common ancestor possessed a conserved, ancestral type of dcw gene cluster and an FtsZ-based cell division mechanism. This implies that Planctomycetes and Chlamydiae may have shifted independently to a non-FtsZ-based cell division mechanism after their separate branchings from their last common ancestor with Verrucomicrobia

TUNNEL GEOLOGY AS SEEN BY GEOLOGISTS: MANHATTAN, NEW YORK CITY

Current exploratory boring operations in and around Manhattan, New York City are providing geologists and geotechnical engineers with a plethora of new and interesting geological information, which has not been previously reported. The rocks encountered, mostly medium to high-grade metamorphic rocks, with both mafic and felsic intrusives, are highly variable in competency and mechanical durability. One of the most frequently encountered rock types is a garnetiferous-muscovite-biotite schist which grades into schistose gneiss and displays a wide variety of structural, compositional, and textural attributes. Metamorphic minerals showing the variable degree of metamorphism include graphite, talc, garnet, kyanite, tourmaline, emory, and occasionally sillimanite. The presence of magnetite-rich zones within the muscovite-garnet schist suggests a mechanism for the concentration of iron during metamorphism. Concentrations of garnet both in the schist and intrusive pegmatite is perhaps indicative of anatectic melting of the protolith. Marble is the dominant rock type east of CAMERON\u27S LINE and it varies from pure white calcitic to dolomitic coarsely crystalline marble, to siliceous calcitic to dolomitic marble. In places, highly pyrite-rich zones, perhaps suggesting hydrothermal alteration of the parent rock due to subsequent mineral-rich fluid flow, are observed. The timing of the sulfide-rich fluid-flow through the original bedrock is yet to be determined. Partial dissolution of marble at various depths has resulted in void (cave) formation and has posed a threat to the boring operations. Rocks of lower abundance include amphibolite, granodiorite, quartzite, serpentinite, and aplite. The overall structural fabric is controlled by the Taconic and Acadian Orogenic events and manifested in the development of characteristic foliation, joint patterns, intrusives, and the degree of metamorphism of the protoliths

Evolution of the electric fields induced in high intensity laser-matter interactions

Multi MeV protons \cite{snavely2000intense} and heavier ions are emitted by thin foils irradiated by high-intensity lasers, due to the huge accelerating fields, up to several teraelectronvolt per meter, at sub-picosecond timescale \cite{dubois2014target}. The evolution of these huge fields is not well understood till today. Here we report, for the first time, direct and temporally resolved measurements of the electric fields produced by the interaction of a short-pulse high-intensity laser with solid targets. The results, obtained with a sub-$100$ fs temporal diagnostics, show that such fields build-up in few hundreds of femtoseconds and lasts after several picoseconds

Hasbara 2.0: Israel’s Public Diplomacy in the Digital Age

The Internet has been a counter-public space for Palestinian liberation politics for over a decade, and digital technologies have become an increasingly important tool for solidarity groups across the world. However, the Israeli state and Zionist supporters worldwide are harnessing the same technologies and platforms to mobilize technology primarily to increase pro-Israel sentiments. The aims of this article are to examine hasbara [Israeli public diplomacy] through an exploration of similar diplomacy programmes; to illustrate how social media have affected the basic algorithms of hasbara; and to probe the assertions of hasbara in the light of pro-Palestinian solidarity. Through a study of public diplomacy, this article critically analyzes hasbara as a site of contestation and a method that is hampered by contradictions. On the one hand, there has been a massive growth in hasbara in recent years—indicated by the increase in funding for it and by its professionalized and centralized character; and on the other hand, hasbara has attracted sharp critiques in Israel for its reputed failures. To understand this contradiction, hasbara must be placed within the context of Israel’s settler-colonialism, which sets the state apart from other ‘post-conflict’ states. This article reviews the methods utilized in hasbara, as well as their readjustment in the context of recent wars. Events in 2014 illustrate that hasbara actually destabilizes Israel’s diplomacy. Online journalism and the suppression of solidarity for Palestine together stimulate more criticism and, in turn, help to shift public opinion. Paradoxically, therefore, adjustments (‘hasbara 2.0’) have underlined the image of Israel as a colonial power engaged in violent occupation

AN UPDATE ON GROUNDWATER CONDITIONS AT THE SITE OF THE YORK COLLEGE CUNY CAMPUS IN SOUTHEASTERN QUEENS COUNTY, NEW YORK CITY

The wells operated by the Jamaica Water Supply Company in Queens represent the only large scale utilization of groundwater for public water supply in New York City in recent years. These wells were shut down, for the most part, beginning in 1996. Since that time, water table elevations in the area, which had been drawn down by the withdrawal activity of the Jamaica Water Supply Company, have risen significantly causing some high groundwater problems, including flooding of basements. The New York City Department of Environmental Protection (NYCDEP) has held public hearings on a contemplated resumption of ground water withdrawal in Southeast Queens, presumably to supplement surface reservoir water supply during drought years and to drawdown the water table, thus alleviating some of the difficulties due to high water table levels. One possible problem with the planned resumption of withdrawal is the existence of a site in the area contaminated with chlorinated hydrocarbons, (PERC), due to a chemical spill. The NYCDEP is contemplating a recovery well, or wells, to isolate the contaminated area from the proposed supply wells. Monitoring wells have been installed on the campus of York College (CUNY). These are being used to establish baseline ground water quality conditions, as well as changes in water table elevation, groundwater flow direction and hydraulic gradient at the York College site. This data will aid in the setup of a groundwater recovery program and help monitor its effectiveness once it begins. The wells will also serve as an on-campus hydrogeological laboratory facility for undergraduate students taking Groundwater Hydrology, Pollution Control Technology, Water Quality Analysis and Management Courses