Preliminary design of a mobile lunar power supply

A preliminary design for a Stirling isotope power system for use as a mobile lunar power supply is presented. Performance and mass of the components required for the system are estimated. These estimates are based on power requirements and the operating environment. Optimizations routines are used to determine minimum mass operational points. Shielding for the isotope system are given as a function of the allowed dose, distance from the source, and the time spent near the source. The technologies used in the power conversion and radiator systems are taken from ongoing research in the Civil Space Technology Initiative (CSTI) program

Ab-initio modelling of defects in MgO

The energetics of the key defects that are observed to occur during simulations of radiation damage in MgO are analysed using density functional theory. The results are compared with those from the empirical potentials used to carry out the radiation damage studies. The formation energies of vacancies, interstitials, Frenkel pairs, di-vacancies and di-interstitials are calculated as a function of the increasing supercell size in order to ensure good convergence. The supercell geometries were chosen to maximise the separation distance between periodic images. Their sizes ranged from cells containing 32 atoms up to cells containing 180 atoms. Results are presented for the formation energies of the first, second and third nearest neighbour defects. Results show that the di-vacancy formation energy is in the region of 4–6 eV and that formation energies for di-interstitials are more than double this, lying in the range 12–16 eV. Comparison of the results show that empirical potentials overestimate the formation energy of di-vacancies by 1–3 eV and underestimate the formation energies of di-interstitials by about 1–2 eV. The relative stability of the defects is, however, correctly predicted by the empirical potentials. The direction and the magnitude of the displacements of the atoms surrounding the defects are in good agreement for all the systems containing interstitials. For the systems containing vacancies the direction of the displacements are in agreement but the empirical potentials predict larger displacements in all cases

HUBUNGAN ANTARA GULA DARAH PUASA (GDP) DENGAN KEJADIAN PERIFERAL ARTERIAL DISEASE PADA PENDERITA DIABETES MELITUS TIPE 2 DI RSUP PROF DR.R.D. KANDOU MANADO

Peripheral Arterial Disease (PAD) tiga kali lebih sering terjadi pada pengidap Diabetes Melitus dibandingkan non-penderita diabetes. PAD cenderung untuk menyerang segmen arteri bawah lutut. Sehingga kita perlu deteksi dini untuk melihat kondisi pembuluh darah perifer. Faktor yang diteliti begitupula dengan nilai ABI dan handheld doppler sangat mudah untuk digunakan dan bersifat non invasif yang dapat menggambarkan kondisi pembuluh darah perifer. Tujuan dari penelitian ini adalah untuk mengetahui hubungan antara faktor GDP dengan kejadian PAD pada pasien Diabetes Melitus tipe 2. Penelitian ini merupakan penelitian analitik observasional dengan jenis desain penelitian cross sectional. Sampel penelitian yang diperoleh sebanyak 156 responden yang merupakan pasien diabetes melitus tipe 2 di RSUP Prof Dr.R.D.Kandou Manado. Pengambilan data dilakukan dengan cara mengambil data ABI dan penunjang lainnya dari rekam medis. Hasilnya akan dianalisa secara statistik dengan menggunakan uji analisis bivariat. Dari hasil analisis terdapat 87 (55,77%) pasien diabetes melitus tipe 2 mengalami PAD, sebanyak 67 (69,1%) GDP ? 126. Berdasarkan uji analisis bivariat didapatkan  p<0,05 (p=0,000). Dengan itu dapat diambil kesimpulan bahwa terdapat hubungan yang signifikan antara GDP dengan kejadian PAD pada pasien Diabetes Melitus tipe 2 di RSUP Prof.R.D. Kandou Manad

Widespread Partisan Gerrymandering Mostly Cancels Nationally, but Reduces Electoral Competition

Congressional district lines in many U.S. states are drawn by partisan actors, raising concerns about gerrymandering. To separate the partisan effects of redistricting from the effects of other factors including geography and redistricting rules, we compare possible party compositions of the U.S. House under the enacted plan to those under a set of alternative simulated plans that serve as a non-partisan baseline. We find that partisan gerrymandering is widespread in the 2020 redistricting cycle, but most of the electoral bias it creates cancels at the national level, giving Republicans two additional seats on average. Geography and redistricting rules separately contribute a moderate pro-Republican bias. Finally, we find that partisan gerrymandering reduces electoral competition and makes the partisan composition of the U.S. House less responsive to shifts in the national vote.Comment: 10 pages, 4 figures, plus references and appendi

Testing management scenarios for the North Sea ecosystem using qualitative and quantitative models

The complexities of ecosystem-based management require stepwise approaches, ideally involving stakeholders, to scope key processes, pressures, and impact in relation to sustainability and management objectives. Use of qualitative methods like Fuzzy Cognitive Mapping (FCM) with a lower skill and data threshold than traditional quantitative models afford opportunity for even untrained stakeholders to evaluate the present and future status of the marine ecosystems under varying impacts. Here, we present the results applying FCM models for subregions of the North Sea. Models for the southern North Sea, Skagerrak, Kattegat, and the Norwegian Trench were developed with varying level of stakeholder involvement. Future scenarios of increased and decreased fishing, and increased seal biomass in the Kattegat, were compared with similar scenarios run on two quantitative ecosystem model. Correspondence in response by the models to the same scenarios was lowest in the southern North Sea, which had the simplest FCM model, and highest in Norwegian Trench. The results show the potential of combining FCM and quantitative modelling approaches in integrated ecosystem assessments (IEAs) and in future ecosystem-based management advice, but to facilitate such comparisons and allow them to complement and enhance our IEAs, it is important that their components are aligned and comparable

Testing management scenarios for the North Sea ecosystem using qualitative and quantitative models

The complexities of ecosystem-based management require stepwise approaches, ideally involving stakeholders, to scope key processes, pressures, and impact in relation to sustainability and management objectives. Use of qualitative methods like Fuzzy Cognitive Mapping (FCM) with a lower skill and data threshold than traditional quantitative models afford opportunity for even untrained stakeholders to evaluate the present and future status of the marine ecosystems under varying impacts. Here, we present the results applying FCM models for subregions of the North Sea. Models for the southern North Sea, Skagerrak, Kattegat, and the Norwegian Trench were developed with varying level of stakeholder involvement. Future scenarios of increased and decreased fishing, and increased seal biomass in the Kattegat, were compared with similar scenarios run on two quantitative ecosystem model. Correspondence in response by the models to the same scenarios was lowest in the southern North Sea, which had the simplest FCM model, and highest in Norwegian Trench. The results show the potential of combining FCM and quantitative modelling approaches in integrated ecosystem assessments (IEAs) and in future ecosystem-based management advice, but to facilitate such comparisons and allow them to complement and enhance our IEAs, it is important that their components are aligned and comparable

Evaluating Bias and Noise Induced by the U.S. Census Bureau's Privacy Protection Methods

The United States Census Bureau faces a difficult trade-off between the accuracy of Census statistics and the protection of individual information. We conduct the first independent evaluation of bias and noise induced by the Bureau's two main disclosure avoidance systems: the TopDown algorithm employed for the 2020 Census and the swapping algorithm implemented for the 1990, 2000, and 2010 Censuses. Our evaluation leverages the recent release of the Noisy Measure File (NMF) as well as the availability of two independent runs of the TopDown algorithm applied to the 2010 decennial Census. We find that the NMF contains too much noise to be directly useful alone, especially for Hispanic and multiracial populations. TopDown's post-processing dramatically reduces the NMF noise and produces similarly accurate data to swapping in terms of bias and noise. These patterns hold across census geographies with varying population sizes and racial diversity. While the estimated errors for both TopDown and swapping are generally no larger than other sources of Census error, they can be relatively substantial for geographies with small total populations.Comment: 21 pages, 6 figure