Liquid oxygen/metal gelled monopropellants

The objectives of this program were to establish the feasibility of metallized/liquid oxygen monopropellants and select the best monopropellant formulation for continued study. The metal powders mixed with the liquid oxygen were aluminum/magnesium (80/20), silicon and iron (Iron was only tested for burning properties). The formulations were first evaluated on whether they detonated when ignited or burned. The formulations only burned when ignited. The viscosity for the formulations ranged from 900 cps to 100 cps at shear rates up to 300 seconds(sup -1). Two percent (by weight) of Cab-O-Sil was added to the aluminum and aluminum/magnesium formulations for gelling while the silicon formulation used three percent. Within a seven hour period, settling was suggested only in the 29 percent aluminum and 29 percent aluminum/magnesium formulations. The monopropellants were burned in a cylinder submerged in a liquid nitrogen bath. Experimental data at ambient pressure indicated that the monopropellants were extinguished when the flame front reached regions submerged under the liquid nitrogen. The burn rate increased dramatically when burned in a cylinder enclosure with less heat sink available to the monopropellant. The test results were inconclusive as to whether the increased burn rate was due to the lower heat sink capacity or the small amount of pressure (2 psi) generated during the burning of the monopropellant. The burning of the aluminum and aluminum/magnesium resulted in a brilliant white flame similar to that of an arc welder. These monopropellants burned in a pulsating manner with the aluminum/magnesium appearing to have less pulsating combustion. The silicon monopropellant burned with an orange glow. No sparks or energetic burning was apparent as with the aluminum or aluminum/magnesium

Comment on "Hypersharp Resonant Capture of Neutrinos as a Laboratory Probe of the Planck Length"

In Phys. Rev. Lett. 102, 091804 (2009) [arXiv:0903.0787], R.S. Raghavan claims that due to motional averaging by lattice vibrations, 18.6 keV electron antineutrinos emitted/captured without recoil from 2-body decay in the 3H/3He system embedded in Nb metal will be observable with natural width. In this comment we argue that 1) stochastic relaxation processes and 2) inhomogeneities in the metal matrices will prevent the generation of antineutrinos with natural width in the 3H/3He system, 3) the different lattice-deformation energies of 3H and 3He in the Nb matrix will drastically decrease the fraction of phononless emission/detection of antineutrinos, 4) the age itself of the 3H source does not affect the linewidth

Transformer bushings and oil leaks: A cost effective way to address oil and nitrogen leaks

Many oil-filled large power transformers have been in service for years. One issue with aging transformers is addressing oil leaks. This article describes a cost-effective technique for repairing these oil leaks. Repairs can be made without draining the oil, or removing bushings. Often the repairs can be made with the transformer in service. This article presents the techniques used by a company that has been performing leak repairs on electric substation equipment since 1988, and works exclusively on electric substation equipment

Self-Care Among Patients with Inflammatory Bowel Disease: An Interview Study

Inflammatory bowel disease (IBD) is a chronic disease of unknown etiology. The disease occurs early in life and the burden of symptoms is significant. Patients need to perform self-care to handle their symptoms, but knowledge about what kind of self-care patients do is limited and these individuals need to learn how to manage the symptoms that arise. The aim of this study was to explore self-care among patients with IBD. Twenty adult patients with IBD, 25–66 years of age, were interviewed. Data were analyzed by performing a qualitative content analysis. Four categories with 10 subcategories emerged from the analysis of the interviews. The self-care patients perform consists of symptom recognition (subcategories: physiological sensations and psychological sensations), handling of symptoms (subcategories: adapting the diet, using medical treatment, stress management, and using complementary alternative medicine), planning life (subcategories: planning for when to do activities and when to refrain from activities), and seeking new options (subcategories: seeking knowledge and personal contacts). Self-care consists of symptom recognition, handling life through planning, and accommodating the existing situation with the ultimate goal of maintaining well-being. Being one step ahead facilitates living with IBD. A decision to actively participate in care of a chronic illness is a prerequisite for self-care. Healthcare professionals must consider patients\u27 potential for and desire for self-care when giving advice on self-care activities. Doing so may help people better cope with IBD

Development of a Self-Care Questionnaire for Clinical Assessment of Self-care in Patients with Inflammatory Bowel Disease: A Psychometric Evaluation

Background: Patients with inflammatory bowel disease have lifelong needs to learn how to manage their symptoms and life situation. The range of actions that patients take in order to manage daily life and maintain health is referred to as self-care. Assessment of self-care inpatients with inflammatory bowel disease could allow targeted support and education by health care professionals.There are no existing measures assessing self-care in patients with inflammatory bowel disease. Objectives: The aim was to develop and evaluate the self-care questionnaire for assessment of self-care among patients with inflammatory bowel disease. Methods: Qualitative and quantitative methods were used to develop inflammatory bowel disease self-care questionnaire. The development and evaluation process was performed in three phases: (1) item generation based on interviews with patients with inflammatory bowel disease(n=20), (2) content validation in a panel of experts (n=6) and patients(n=100) assessed with the content validity index, cognitive interviews and quantifying and ranking the items to determine the usability of the questionnaire, and (3) final evaluation through a pilot study (n=93) with test-retest evaluation (n=50). An expert review group of three nurses and one physician continuously discussed the result during the development process. Results: A total of 91 patients with Crohn\u27s disease and 102 with ulcerative colitis participated. The final self-care questionnaire consists of 22 items. Assessment of content validity indicated that the items were adequate and easy to understand. Test-retest reliability was confirmed with intraclass correlations above 0.6 after a three week interval, for all items except one. Conclusion: An inflammatory bowel disease-specific self-care questionnaire was developed using structured methods. The evaluation indicated good validity and reliability. The questionnaire may be a useful tool to assess the ability of patients with inflammatory bowel disease to perform routine self-care

Mossbauer spectroscopy study of the "mysterious" magnetic transition in lambda-(BETS)2FeCl4

The compound lambda-(BETS)2FeCl4 provides an effective demonstration of the interaction of pi-conduction electron and d-electron localized moment systems in molecular crystalline materials where antiferromagnetic insulating and magnetic field induced superconducting states can be realized. The metal-insulator transition has been thought to be cooperative, involving both the itinerant pi- electron and localized d-electron spins where antiferromagnetic order appears in both systems simultaneously. However, recent specific heat data has indicated otherwise [Akiba et al., J. Phys. Soc. Japan 78,033601(2009)]: although the pi-electron system orders antiferromagnetically and produces a metal-insulator transition, a "mysterious" paramagnetic d-electron state remains. We report 57Fe Mossbauer measurements that support the paramagnetic model, provided the d-electron spins remain in a fast relaxation state below the transition. From the measured hyperfine fields, we also determine the temperature dependence of the pi-d electron exchange field.Comment: 10 pages, 3 figures, 1 tabl

Source control options for reducing emission of priority pollutants from urban areas.

The overall aim of the ScorePP project is to develop comprehensive and appropriate source control strategies that authorities, cities, water utilities and the chemical industry can employ to reduce emissions of priority pollutants (PPs) from urban areas into the receiving water environment. Focus is on the 33 priority and priority hazardous substances and substance groups identified in the European Water Framework Directive. However, this list may be expanded to include emerging pollutants or reduced if appropriate model compounds can be identified. The initial work focuses on 67 substances, including substances identified in the proposed European environmental quality standard (EQS) directive as well as the defined example compounds and several organometallic derivatives. Information on inherent properties, environmental presence and fate, and legislative issues is made available in open database format, and a data management system combining chemical identification (CAS#), NACE economic activity classifications and NOSE-P emission source classifications has been developed as a basis for spatial characterisation of PP sources using GIS. Further work will focus on dynamic urban scale source-flux models, identifying emission patterns and optimising monitoring programmes in case studies and multi-criteria comparison of source control versus end-of-pipe mitigation options in relation to their economic, social and environmental impacts

Recoilless Resonant Emission and Detection of Electron Antineutrinos

Recoilless resonant capture of monoenergetic electron antineutrinos (Moessbauer antineutrinos) emitted in bound-state beta-decay in the system 3H - 3He is discussed. The recoilfree fraction including a possible phonon excitation due to local lattice expansion and contraction at the time of the nuclear transition, homogeneous and inhomogeneous line broadening, and the relativistic second-order Doppler effect are considered. It is demonstrated that homogeneous line broadening is essential due to stochastic magnetic relaxation processes in a metallic lattice. Inhomogeneous line broadening plays an equally important role. An essential issue which has been overlooked up to now, is an energy shift of the resonance line due to the direct influence of the binding energies of the 3H and 3He atoms in the lattice on the energy of the electron antineutrinos. This energy shift as well as the second-order Doppler shift exhibit variations in a non-perfect (inhomogeneous) lattice and may seriously jeopardize the observation of Moessbauer antineutrinos. If successful in spite of these enormous difficulties, Moessbauer antineutrino experiments could be used to gain new and deep insights into the nature of neutrino oscillations, determine the neutrino mass hierarchy as well as up to now unknown oscillation parameters, search for sterile neutrinos, and measure the gravitational redshift of electron antineutrinos in the field of the Earth.Comment: To appear in Journal of Physics: Conference Series; Proceedings of Neutrino 2008, Christchurch, New Zealan

Magnetic excitations in coupled Haldane spin chains near the quantum critical point

Two quasi-1-dimensional S=1 quantum antiferromagnetic materials, PbNi2V2O8 and SrNi2V2O8, are studied by inelastic neutron scattering on powder samples. While magnetic interactions in the two systems are found to be very similar, subtle differences in inter-chain interaction strengths and magnetic anisotropy are detected. The latter are shown to be responsible for qualitatively different ground state properties: magnetic long-range order in SrNi2V2O8 and disordered ``spin liquid'' Haldane-gap state in PbNi2V2O8.Comment: 15 figures, Figs. 5,9, and 10 in color. Some figures in JPEG format. Complete PostScript and PDF available from http://papillon.phy.bnl.gov/publicat.ht