1,229 research outputs found
Issues concerning centralized versus decentralized power deployment
The results of a study of proposed lunar base architectures to identify issues concerning centralized and decentralized power system deployment options are presented. The power system consists of the energy producing system (power plant), the power conditioning components used to convert the generated power into the form desired for transmission, the transmission lines that conduct this power from the power sources to the loads, and the primary power conditioning hardware located at the user end. Three power system architectures, centralized, hybrid, and decentralized, were evaluated during the course of this study. Candidate power sources were characterized with respect to mass and radiator area. Two electrical models were created for each architecture to identify the preferred method of power transmission, dc or ac. Each model allowed the transmission voltage level to be varied at assess the impact on power system mass. The ac power system models also permitted the transmission line configurations and placements to determine the best conductor construction and installation location. Key parameters used to evaluate each configuration were power source and power conditioning component efficiencies, masses, and radiator areas; transmission line masses and operating temperatures; and total system mass
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Provision of disability adaptations to the home: analysis of household survey data
The move towards greater provision of healthcare at home has been a significant policy intention for the last two decades (Ham et al. 2012). Key to this ambition is the need to provide suitable accommodation for disabled households by installing a range of possible adaptations. Using data from English Housing Surveys of 2003/4 and 2009/10, we compare levels of the provision of adaptations with a number of socio-cultural variables, and report on some significant correlations. This includes most importantly, bias against non-white disabled households and younger disabled households, a significant link between rented accommodation and disabled households, and a worrying increase in the proportion of adaptations deemed by the householders to be ‘not needed’, from 7% to 25%, over that six year time period.
We discuss the context of these results and conclude with an outline plan for future research, which is urgently needed to verify and understand the issues raised
Interview of Kevin J. Harty, Ph.D.
Dr. Kevin J. Harty was born in Brooklyn, New York in 1948. He grew up in Brooklyn until his family moved to Chicago when he was about twelve years old. His father worked for the telephone company, which spurred the family’s move to Chicago, and his mother stayed home and cared for the family. Dr. Harty attended high school in the suburbs of Chicago, graduating when he was fifteen and a half years old. Between high school and college, he worked for a year in a department store, and briefly considered going into the fashion industry. He attended Marquette University for his undergraduate degree, graduating in 1970 at the age of twenty-two, with a B.A. in English and German. He then attended the University of Pennsylvania, earning a master’s degree in English in 1971 and a Ph.D. in English in 1974. After earning his Ph.D., Dr. Harty began his teaching career at Centenary College of Louisiana and taught for brief periods at Rhode Island College and Temple University before starting a position as an English professor at La Salle University in 1982. Dr. Harty won the 1992 Lindback Award for Distinguished Teaching at La Salle University. He went on to become the chair of the English department, and served as chair from 2002 to 2018, winning the Faculty Distinguished Scholarship Award in 2015. He recently stepped down as chair and continues to teach a wide variety of English courses at La Salle. Dr. Harty is trained as a medievalist and is considered a specialist in Medieval Literature; Chaucer; Vikings; literary traditions of King Arthur, Joan of Arc, and Robin Hood; film representations of the Middle Ages; cinematic adaptations of literary texts, and pop culture as related to AIDS. He is a renowned scholar and has written several books and many articles on a variety of his specialties, many of which have become industry standards
High-fidelity quantum logic gates using trapped-ion hyperfine qubits
We demonstrate laser-driven two-qubit and single-qubit logic gates with
fidelities 99.9(1)% and 99.9934(3)% respectively, significantly above the
approximately 99% minimum threshold level required for fault-tolerant quantum
computation, using qubits stored in hyperfine ground states of calcium-43 ions
held in a room-temperature trap. We study the speed/fidelity trade-off for the
two-qubit gate, for gate times between 3.8s and 520s, and develop a
theoretical error model which is consistent with the data and which allows us
to identify the principal technical sources of infidelity.Comment: 1 trap, 2 ions, 3 nines. Detailed write-up of arXiv:1406.5473
including single-qubit gate data als
High-fidelity trapped-ion quantum logic using near-field microwaves
We demonstrate a two-qubit logic gate driven by near-field microwaves in a
room-temperature microfabricated ion trap. We measure a gate fidelity of
99.7(1)\%, which is above the minimum threshold required for fault-tolerant
quantum computing. The gate is applied directly to Ca "atomic clock"
qubits (coherence time ) using the microwave
magnetic field gradient produced by a trap electrode. We introduce a
dynamically-decoupled gate method, which stabilizes the qubits against
fluctuating a.c.\ Zeeman shifts and avoids the need to null the microwave
field
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Consequences of Biomarker Analysis on the Cost-Effectiveness of Cetuximab in Combination with FOLFIRI as a First-Line Treatment of Metastatic Colorectal Cancer: Personalised Medicine at Work
Background
Therapies may be more efficacious when targeting a patient subpopulation with specific attributes, thereby enhancing the cost-effectiveness of treatment. In the CRYSTAL study, patients with metastatic colorectal cancer (mCRC) were treated with cetuximab plus FOLFIRI or FOLFIRI alone until disease progression, unacceptable toxic effects or withdrawal of consent.
Objective
To determine if stratified use of cetuximab based on genetic biomarker detection improves cost-effectiveness.
Methods
We used individual patient data from CRYSTAL to compare the cost-effectiveness, cost per life-year (LY) and cost per quality-adjusted LY (QALY) gained of cetuximab plus FOLFIRI versus FOLFIRI alone in three cohorts of patients with mCRC: all randomised patients (intent-to-treat; ITT), tumours with no detectable mutations in codons 12 and 13 of exon 2 of the KRAS protein (‘KRAS wt’) and no detectable mutations in exons 2, 3 and 4 of KRAS and exons 2, 3 and 4 of NRAS (‘RAS wt’). Survival analysis was conducted using RStudio, and a cost-utility model was modified to allow comparison of the three cohorts.
Results
The deterministic base-case ICER (cost per QALY gained) was £130,929 in the ITT, £72,053 in the KRAS wt and £44,185 in the RAS wt cohorts for cetuximab plus FOLFIRI compared with FOLFIRI alone. At a £50,000 willingness-to-pay threshold, cetuximab plus FOLFIRI has a 2.8, 20 and 63% probability of being cost-effective for the ITT, KRAS wt and RAS wt cohorts, respectively, versus FOLFIRI alone.
Conclusion
Screening for mutations in both KRAS and NRAS may provide the most cost-effective approach to patient selection
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