961 research outputs found

    A feasibility study on using inkjet technology, micropumps, and MEMs as fuel injectors for bipropellant rocket engines

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    Control over drop size distributions, injection rates, and geometrical distribution of fuel and oxidizer sprays in bi-propellant rocket engines has the potential to produce more efficient, more stable, less polluting rocket engines. This control also offers the potential of an engine that can be throttled, working efficiently over a wide range of output thrusts. Inkjet printing technologies, MEMS fuel atomizers, and piezoelectric injectors similar in concept to those used in diesel engines are considered for their potential to yield a new, more active injection scheme for a rocket engine. Inkjets are found to be unable to pump at sufficient pressures, and have possibly dangerous failure modes. Active injection is found to be feasible if high pressure drop along the injector plate are used. A conceptual design is presented and its basic behavior assessed

    The GALILEO GALILEI small-satellite mission with FEEP thrusters (GG)

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    The Equivalence Principle, formulated by Einstein generalizing Galileo’s and Newton’s work, is a fundamental principle of modern physics. As such it should be tested as accurately as possible. Its most direct consequence, namely the Universality of Free Fall, can be tested in space, in a low Earth orbit, the crucial advantage being that the driving signal is about three orders of magnitude stronger than on Earth. GALILEO GALILEI (GG) is a small space mission designed for such a high-accuracy test. At the time of print, GG has been selected by ASI (Agenzia Spaziale Italiana) as a candidate for the next small Italian mission. Ground tests of the proposed apparatus now indicate that an accuracy of 1 part in 1017 is within the reach of this small mission

    Special Memory for Addition to Process Emulation Ibm Pc / Xt

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    To avoid errors charging program into the EPROM emulator created a device as a temporary substitute for the position of the EPROM emulator. This tool serves as a pilot program before it is loaded into the EPROM emulator. Because this type of equipment, including types of memory devices, then to occupy the memory address of the IBM PC / XT had to be recognized and this address is not used by other memory devices. To berkomnukasi with the IBM PC system required interfacing and programming language that can be directly translated by the IBM PC system

    Parabolic oblique derivative problem in generalized Morrey spaces

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    We study the regularity of the solutions of the oblique derivative problem for linear uniformly parabolic equations with VMO coefficients. We show that if the right-hand side of the parabolic equation belongs to certain generalized Morrey space than the strong solution belongs to the corresponding generalized Sobolev-Morrey space

    Oral health-related quality of life in partially edentulous patients before and after implant therapy: a 2-year longitudinal study

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    The aim of this study was to measure the Oral Health-Related Quality of Life (OHRQoL) before and after a prosthodontic implant therapy so to determine the physical and psychological impact of implant-supported fixed partial dentures (IFPD) rehabilitation among edentulous patients. Methods. 50 partially edentulous patients aged 40-70 years, treated with IFPD, completed the OHRQoL questionnaire before the implant surgery (Time 0) and 2 years after their whole implant-prosthetic rehabilitation (Time 1). The questionnaire was proposed in a short version of Oral Health Impact Profile (OHIP-14, range 0-56) and analyzed through the ‘additive method’. We evaluated statistical mean, standard deviation, median, variance and mode of all OHIP-14 domains and the statistical significance about oral changes at Time 0 and Time 1 using the Chi-square test (p-values 0.05). Patients with I and IV Kennedy’s class edentulism showed better improvement (p < 0.05). Preoperative and post-treatment assessments of OHRQoL exhibited significant differences. The IFPD treatment had a positive effect on the OHRQoL, which improved better in patients with I and IV Kennedy’s edentulous class

    Atomic force microscopy of bacteria from periodontal subgingival biofilm: Preliminary study results

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    OBJECTIVE: Atomic force microscope (AFM) is a technology that allows analysis of the nanoscale morphology of bacteria within biofilm and provides details that may be better useful for understanding the role of bacterial interactions in the periodontal disease. MATERIAL AND METHODS: Five patients with periodontal ≥5 mm pockets diagnosed as generalized periodontitis and five patients with slight gingivitis were selected for the investigation. Bacteria biofilms were collected and morphologically investigated by AFM application. RESULTS: The investigation revealed how periodontitis bacteria are characterized by specific morphologic features of the cell wall. The major representative species of bacteria causing periodontal diseases have been reproduced by a three-dimensional reconstruction showing the bacteria surface details. CONCLUSIONS: The presence of complex glycocalyx structures, bacteriophage-like vesicles, spirochetes (classic and cystic morphology) and bacterial co-aggregation has been identified by the AFM analysis. The results suggest that AFM is a reliable technique for studying bacterial morphology and for examining microbial interactions in dental plaque

    CAR T-Cell Therapies in Italy: Patient Access Barriers and Recommendations for Health System Solutions

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    CAR T-cell therapy has emerged as a potentially transformative immunotherapy for certain B-cell malignancies including relapsed/refractory diffuse large B-cell lymphoma (DLBCL). Unhindered and appropriate access for eligible patients is essential to enable optimal outcomes and depends on effective interplay of stakeholders and processes along the patient’s therapeutic journey. In Italy, CAR T-cell therapies have been awarded innovation status by the Italian Medicines Agency (AIFA) and were integrated into routine patient care under specific criteria. However, our analysis indicates that fewer than one in five DLBCL patients eligible under the EMA authorization, or around one in three DLBCL patients eligible under the AIFA criteria, received treatment with a licensed CAR T-cell therapy product in 2020. This publication describes key patient access barriers to CAR T-cell therapies in Italy and provides recommendations on potential solutions at the health system level

    Dynamical response of the "GGG" rotor to test the Equivalence Principle: theory, simulation and experiment. Part I: the normal modes

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    Recent theoretical work suggests that violation of the Equivalence Principle might be revealed in a measurement of the fractional differential acceleration η\eta between two test bodies -of different composition, falling in the gravitational field of a source mass- if the measurement is made to the level of η1013\eta\simeq 10^{-13} or better. This being within the reach of ground based experiments, gives them a new impetus. However, while slowly rotating torsion balances in ground laboratories are close to reaching this level, only an experiment performed in low orbit around the Earth is likely to provide a much better accuracy. We report on the progress made with the "Galileo Galilei on the Ground" (GGG) experiment, which aims to compete with torsion balances using an instrument design also capable of being converted into a much higher sensitivity space test. In the present and following paper (Part I and Part II), we demonstrate that the dynamical response of the GGG differential accelerometer set into supercritical rotation -in particular its normal modes (Part I) and rejection of common mode effects (Part II)- can be predicted by means of a simple but effective model that embodies all the relevant physics. Analytical solutions are obtained under special limits, which provide the theoretical understanding. A simulation environment is set up, obtaining quantitative agreement with the available experimental data on the frequencies of the normal modes, and on the whirling behavior. This is a needed and reliable tool for controlling and separating perturbative effects from the expected signal, as well as for planning the optimization of the apparatus.Comment: Accepted for publication by "Review of Scientific Instruments" on Jan 16, 2006. 16 2-column pages, 9 figure
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