Synthesis of calculational methods for design and analysis of radiation shields for nuclear rocket systems

Eight computer programs make up a nine volume synthesis containing two design methods for nuclear rocket radiation shields. The first design method is appropriate for parametric and preliminary studies, while the second accomplishes the verification of a final nuclear rocket reactor design

Quantum Trajectory Approach to the Stochastic Thermodynamics of a Forced Harmonic Oscillator

I formulate a quantum stochastic thermodynamics for the quantum trajectories of a continuously-monitored forced harmonic oscillator coupled to a thermal reservoir. Consistent trajectory-dependent definitions are introduced for work, heat, and entropy, through engineering the thermal reservoir from a sequence of two-level systems. Within this formalism the connection between irreversibility and entropy production is analyzed and confirmed by proving a detailed fluctuation theorem for quantum trajectories. Finally, possible experimental verifications are discussed.Comment: 16 pages, 3 figures, submitted to PRE; expanded introduction and conclusion, corrected typos, new figure

On time and the quantum-to-classical transition in Jordan-Brans-Dicke quantum gravity

Any quantum theory of gravity which treats the gravitational constant as a dynamical variable has to address the issue of superpositions of states corresponding to different eigenvalues. We show how the unobservability of such superpositions can be explained through the interaction with other gravitational degrees of freedom (decoherence). The formal framework is canonically quantized Jordan-Brans-Dicke theory. We discuss the concepts of intrinsic time and semiclassical time as well as the possibility of tunneling into regions corresponding to a negative gravitational constant. We calculate the reduced density matrix of the Jordan-Brans-Dicke field and show that the off-diagonal elements can be sufficiently suppressed to be consistent with experiments. The possible relevance of this mechanism for structure formation in extended inflation is briefly discussed.Comment: 10 pages, Latex, ZU-TH 15/93, BUTP-93/1

Statistical Communication Theory

Contains reports on six research projects

2023 Updated MASCC/ESMO Consensus Recommendations: prevention of radiotherapy-and chemoradiotherapy-induced nausea and vomiting

Purpose Radiotherapy and chemoradiotherapy-induced nausea and vomiting (RINV and C-RINV) are common and distressing, and there is a need for guidance for clinicians to provide up to date optimal antiemetic prophylaxis and treatment. Through a comprehensive review of the literature concerning RINV and C-RINV, this manuscript aims to update the evidence for antiemetic prophylaxis and rescue therapy and provide a new edition of recommendations for the MASCC/ESMO antiemetic guidelines for RINV and C-RINV. Methods A systematic review of the literature including data published from May 1, 2015, to January 31, 2023, was performed. All authors assessed the literature. Results The searches yielded 343 references; 37 met criteria for full article review, and 20 were ultimately retained. Only one randomized study in chemoradiation had the impact to provide new recommendations for the antiemetic guideline. Based on expert consensus, it was decided to change the recommendation for the “low emetic risk” category from “prophylaxis or rescue” to “rescue” only, while the drugs of choice remain unchanged. Conclusion As for the previous guideline, the serotonin receptor antagonists are still the cornerstone in antiemetic prophylaxis of nausea and vomiting induced by high and moderate emetic risk radiotherapy. The guideline update provides new recommendation for the management of C-RINV for radiotherapy and concomitant weekly cisplatin. To avoid overtreatment, antiemetic prophylaxis is no longer recommended for the “low emetic risk” category

Individualising drug dispensaries in a university hospital

BACKGROUND: In hospitals and other healthcare institutions drugs are routinely stored in designated satellite areas on the wards. Often ad hoc decisions are made by clinicians and nurses regarding drug type and quantity to be stored. As a result the number of different drugs and drug packages in storage tends to increase, which may lead to inefficient drug handling and become a potential risk factor in the medication control process. Based on an extended analysis of drug inventories on three different wards it was hypothesized that a ward-individualised formulary (WIF) can halve the number of different drugs and drug packages in a drug dispensary and hence reduce bound capital, money lost through expired drugs, and facilitate safer drug handling. The interdisciplinary intervention described here took place on three 40-bed wards in a 700-bed university hospital housing patients in general internal medicine, haematology, nephrology and oncology. METHODS: A WIF was defined by including all drugs from the hospital formulary ordered at least three times in the past six months. A pharmacist, a nurse and a clinician reviewed the inclusion list of drugs and clinicians were strongly encouraged to prescribe drugs primarily from the WIF. Drugs excluded from the WIF were removed from the drug dispensaries and the number of included drug packages stored in the remote dispensaries was reduced according to their order history. Drug inventory on the wards was monitored from February 2004 to April 2006. RESULTS: The initial drug dispensary inventories on wards A, B and C consisted of 2031, 1667 and 1536 packages with 943, 897 and 831 different drugs valued at h 83 931, h 44 590 and h 57 285. respectively. After adjusting the drug dispensaries according to the WIF drug dispensary inventories on wards A, B and C consisted of 808 (-60%), 600 (-64%) and 485 (-68%) packages with 415 (-56%), 334 (-63%) and 376 (-55%) different drugs valued euro 28 012 (-67%), euro 10 381 (-77%) an euro 17 898 (-69%). The overall reductions the number of packages, the different drugs and the drug value were comparable (<50%) and remained low during the entire observation time (A: 18 months, B: 13 months, C: 8 months). CONCLUSION: Rearranging dispensaries by individualizing the drug inventory according to the needs of the ward by introducing a WIF is a valuable means to significantly (<50%) reduce [1] the number of drug packages, [2] the number of different drugs stored and [3] the capital bound drugs. The positive effects of the WIF are supported by the interdisciplinary interaction of the different professional groups involved in the medication process. The leaner drug dispensaries offer optimal basic conditions for introducing new IT-based systems to further increase the safety of the medication process

Analysis of the Hydrogen-rich Magnetic White Dwarfs in the SDSS

We have calculated optical spectra of hydrogen-rich (DA) white dwarfs with magnetic field strengths between 1 MG and 1000 MG for temperatures between 7000 K and 50000 K. Through a least-squares minimization scheme with an evolutionary algorithm, we have analyzed the spectra of 114 magnetic DAs from the SDSS (95 previously published plus 14 newly discovered within SDSS, and five discovered by SEGUE). Since we were limited to a single spectrum for each object we used only centered magnetic dipoles or dipoles which were shifted along the magnetic dipole axis. We also statistically investigated the distribution of magnetic-field strengths and geometries of our sample.Comment: to appear in the proceedings of the 16th European Workshop on White Dwarfs, Barcelona, 200

Landslide mapping for susceptibility and hazard assessment: North York Moors, UK

The British Geological Survey (BGS) has developed a multi-stage methodology for landslide mapping by augmenting traditional mapping techniques with new geospatial technologies. This allows better characterisation and understanding of the country’s landslides: an essential requirement for landslide susceptibility modelling, risk assessment and resilient infrastructure planning. The BGS methodology has most recently been applied to the North York Moors National Park in northern England, UK: an area with steep slopes, landslide-prone lithologies and an exposed coastal section but few recorded landslide events. Over 550 landslides have now been identified and data on the characteristics and mechanisms of these have been used to inform hazard assessments and susceptibility modelling research including the National Landslide Database, the National Landslide Domains Map and the National Geohazard Assessment

Optimal Resource Allocation in Random Networks with Transportation Bandwidths

We apply statistical physics to study the task of resource allocation in random sparse networks with limited bandwidths for the transportation of resources along the links. Useful algorithms are obtained from recursive relations. Bottlenecks emerge when the bandwidths are small, causing an increase in the fraction of idle links. For a given total bandwidth per node, the efficiency of allocation increases with the network connectivity. In the high connectivity limit, we find a phase transition at a critical bandwidth, above which clusters of balanced nodes appear, characterised by a profile of homogenized resource allocation similar to the Maxwell's construction.Comment: 28 pages, 11 figure