590 research outputs found
Synthesis and Properties of Bis(nitrocarbamoylethyl) Nitramine - A New Energetic Open-Chain Nitrocarbamate
The nitrocarbamate derivative of the well-known and intensively investigated nitro ester DINA was prepared and studied. Starting with bis(hydroxyethyl) nitramine obtained from DINA, the corresponding carbamate was obtained by treatment with chlorosulfonyl isocyanate (CSI). Using fuming nitric acid only as nitration reagent, the target compound bis(nitrocarbamoylethyl) nitramine was synthesized. Furthermore, a route to the salt bis(nitrocarbamoylethyl)ammonium nitrate by a simple two step synthesis starting from diethanolamine was revealed. The compounds were fully characterized by NMR spectroscopy, X-ray diffraction, differential thermal analysis, vibrational analysis and elemental analysis. The sensitivities towards impact and friction of the energetic compounds were measured, as well as their energetic properties determined by using the energies of formation, calculated on the CBS4-M level of theory, with the EXPLO5 computer code
Privacy Architectures: Reasoning About Data Minimisation and Integrity
Privacy by design will become a legal obligation in the European Community if
the Data Protection Regulation eventually gets adopted. However, taking into
account privacy requirements in the design of a system is a challenging task.
We propose an approach based on the specification of privacy architectures and
focus on a key aspect of privacy, data minimisation, and its tension with
integrity requirements. We illustrate our formal framework through a smart
metering case study.Comment: appears in STM - 10th International Workshop on Security and Trust
Management 8743 (2014
Genetic Variability of the European Corn Borer, Ostrinia nubilalis, Suggests Gene Flow Between Populations in the Midwestern United States
The European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), is a widely distributed and serious economic pest to corn production in the U.S. Genetic variability of O. nubilalis was studied in 18 sub-populations in the upper Midwestern United States using amplified fragment length polymorphism. The relatively low GST values indicate that more variation exists within populations than between populations. High gene flow (Nm) values were indicated across the entire O. nubilalis population; the lowest degree of gene flow was in the northern samples (Nm = 1.96) and the highest degree of gene flow was in the southern samples (Nm = 2.77). The differences observed in the respective regions (north vs. south) may be explained by the voltinism patterns (univoltine vs. multivoltine, respectively) of O. nubilalis: southern multivoltine populations have opportunities for multiple matings for the duration of the year, further mix alleles. AMOVA results also indicated that most of the genetic variation was within sub-populations (≈ 81% of total variation); less variation (≈ 13%) was detected among populations within each of the three regions as designated for this study. However, the most striking and unexpected result was the low percentage of variation between all groups (≈ 6%), further supporting implications of a high degree of gene flow. These results provide support for current requirements of refugia corn planting in Bt-corn management. These results also indicate that if resistance to Bt were to evolve in O. nubilalis, quick action would be necessary to deter the rapid spread of the gene for resistance
FACT -- the First Cherenkov Telescope using a G-APD Camera for TeV Gamma-ray Astronomy (HEAD 2010)
Geiger-mode Avalanche Photodiodes (G-APD) bear the potential to significantly
improve the sensitivity of Imaging Air Cherenkov Telescopes (IACT). We are
currently building the First G-APD Cherenkov Telescope (FACT) by refurbishing
an old IACT with a mirror area of 9.5 square meters and construct a new, fine
pixelized camera using novel G-APDs. The main goal is to evaluate the
performance of a complete system by observing very high energy gamma-rays from
the Crab Nebula. This is an important field test to check the feasibility of
G-APD-based cameras to replace at some time the PMT-based cameras of planned
future IACTs like AGIS and CTA. In this article, we present the basic design of
such a camera as well as some important details to be taken into account.Comment: Poster shown at HEAD 2010, Big Island, Hawaii, March 1-4, 201
Characterization of Western Corn Rootworm (Coleoptera: Chrysomelidae) susceptibility to foliar insecticides in northeast Nebraska
Foliar-applied insecticides are commonly used for adult Western Corn Rootworm (WCR), Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), control in Nebraska but little efficacy data is available. Anecdotal reports of reduced efficacy in areas of northeast Nebraska led to the conduct of this study. Objectives were to (i) evaluate the efficacy of commercial applications of commonly used formulated insecticides (bifenthrin, lambda-cyhalothrin, chlorpyrifos, or tank mixes) for WCR control in 7 northeast Nebraska counties during 2019 and 2020 and (ii) conduct adult WCR concentration-response vial bioassays with bifenthrin, chlorpyrifos, and dimethoate active ingredients on a subset of field populations. Whole plant counts (WPC) were used to measure WCR densities in insecticide-treated and untreated maize fields before and after insecticide application. Field control was excellent with organophosphate/pyrethroid tank mixes as proportional change in mean WPC of treated fields was significantly reduced (\u3e0.90) versus untreated fields where little change in WPC occurred. The exception was one treated Boone County field where proportional reduction in WPC was ≤0.78. Bioassays revealed LC50s and resistance ratios of most populations exposed to bifenthrin and dimethoate were not significantly different than the susceptible control. Most populations exhibited a low level of chlorpyrifos resistance when compared to the susceptible control. Field and lab data suggest the local onset of practical WCR field-evolved resistance to bifenthrin in Boone County and chlorpyrifos in Boone and Colfax counties. Results of this study will increase our understanding of WCR resistance evolution, serve as a comprehensive baseline for future research, and inform WCR management programs
FACT -- The G-APD revolution in Cherenkov astronomy
Since two years, the FACT telescope is operating on the Canary Island of La
Palma. Apart from its purpose to serve as a monitoring facility for the
brightest TeV blazars, it was built as a major step to establish solid state
photon counters as detectors in Cherenkov astronomy. The camera of the First
G-APD Cherenkov Telesope comprises 1440 Geiger-mode avalanche photo diodes
(G-APD), equipped with solid light guides to increase the effective light
collection area of each sensor. Since no sense-line is available, a special
challenge is to keep the applied voltage stable although the current drawn by
the G-APD depends on the flux of night-sky background photons significantly
varying with ambient light conditions. Methods have been developed to keep the
temperature and voltage dependent response of the G-APDs stable during
operation. As a cross-check, dark count spectra with high statistics have been
taken under different environmental conditions. In this presentation, the
project, the developed methods and the experience from two years of operation
of the first G-APD based camera in Cherenkov astronomy under changing
environmental conditions will be presented.Comment: Proceedings of the Nuclear Science Symposium and Medical Imaging
Conference (IEEE-NSS/MIC), 201
Women at Altitude: Sex-Related Physiological Responses to Exercise in Hypoxia.
Sex differences in physiological responses to various stressors, including exercise, have been well documented. However, the specific impact of these differences on exposure to hypoxia, both at rest and during exercise, has remained underexplored. Many studies on the physiological responses to hypoxia have either excluded women or included only a limited number without analyzing sex-related differences. To address this gap, this comprehensive review conducted an extensive literature search to examine changes in physiological functions related to oxygen transport and consumption in hypoxic conditions. The review encompasses various aspects, including ventilatory responses, cardiovascular adjustments, hematological alterations, muscle metabolism shifts, and autonomic function modifications. Furthermore, it delves into the influence of sex hormones, which evolve throughout life, encompassing considerations related to the menstrual cycle and menopause. Among these physiological functions, the ventilatory response to exercise emerges as one of the most sex-sensitive factors that may modify reactions to hypoxia. While no significant sex-based differences were observed in cardiac hemodynamic changes during hypoxia, there is evidence of greater vascular reactivity in women, particularly at rest or when combined with exercise. Consequently, a diffusive mechanism appears to be implicated in sex-related variations in responses to hypoxia. Despite well-established sex disparities in hematological parameters, both acute and chronic hematological responses to hypoxia do not seem to differ significantly between sexes. However, it is important to note that these responses are sensitive to fluctuations in sex hormones, and further investigation is needed to elucidate the impact of the menstrual cycle and menopause on physiological responses to hypoxia
FACT - The First G-APD Cherenkov Telescope: Status and Results
The First G-APD Cherenkov telescope (FACT) is the first telescope using
silicon photon detectors (G-APD aka. SiPM). It is built on the mount of the
HEGRA CT3 telescope, still located at the Observatorio del Roque de los
Muchachos, and it is successfully in operation since Oct. 2011. The use of
Silicon devices promises a higher photon detection efficiency, more robustness
and higher precision than photo-multiplier tubes. The FACT collaboration is
investigating with which precision these devices can be operated on the
long-term. Currently, the telescope is successfully operated from remote and
robotic operation is under development. During the past months of operation,
the foreseen monitoring program of the brightest known TeV blazars has been
carried out, and first physics results have been obtained including a strong
flare of Mrk501. An instantaneous flare alert system is already in a testing
phase. This presentation will give an overview of the project and summarize its
goals, status and first results
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