1,143 research outputs found
The Closing of the Gates The Politics of Xenophobia in Immigrant Nations
The following study seeks to explain the reason for increasing immigration restriction in countries with strong histories of immigration. The main country of focus is the United States, with Argentina and Canada analyzed in comparison. After exploring the conventional answers of: right-wing populism, economic explanations, and security concerns, the study makes the argument that a history of deep-rooted xenophobia is the best explanation for increasing immigration restriction in all three countries of analysis
Hybrid adiabatic quantum computing for tomographic image reconstruction -- opportunities and limitations
Our goal is to reconstruct tomographic images with few measurements and a low
signal-to-noise ratio. In clinical imaging, this helps to improve patient
comfort and reduce radiation exposure. As quantum computing advances, we
propose to use an adiabatic quantum computer and associated hybrid methods to
solve the reconstruction problem. Tomographic reconstruction is an ill-posed
inverse problem. We test our reconstruction technique for image size, noise
content, and underdetermination of the measured projection data. We then
present the reconstructed binary and integer-valued images of up to 32 by 32
pixels. The demonstrated method competes with traditional reconstruction
algorithms and is superior in terms of robustness to noise and reconstructions
from few projections. We postulate that hybrid quantum computing will soon
reach maturity for real applications in tomographic reconstruction. Finally, we
point out the current limitations regarding the problem size and
interpretability of the algorithm
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One-fifth-scale and full-scale fuel element rocking tests. [HTGR]
Using /sup 1///sub 5/-scale and /sup 1///sub 1/-scale (prototype H451) fuel elements, one, two, or three stacked elements on a clamped base element were rocked from an initial release position. Relative displacement, rock-down loads, and dowel pin shear forces were measured. A scaled comparison between /sup 1///sub 5/-scale and /sup 1///sub 1/-scale results was made to evaluate the model scaling laws, and an error analysis was performed to assess the accuracy and usefulness of the test data
Dietary supplementation with lactose or artificial sweetener enhances swine gut Lactobacillus population abundance
The commensal bacteria Lactobacillus are widely used as probiotic organisms conferring a heath benefit on the host. They have been implicated in promoting gut health via the stimulation of host immunity and anti-inflammatory responses, as well as protecting the intestinalmucosa against pathogen invasion. Lactobacilli grow by fermenting sugars and starches and produce lactic acid as their primary metabolic product. For efficient utilisation of varied carbohydrates, lactobacilli have evolved diverse sugar transport and metabolic systems, which are specifically induced by their own substrates. Many bacteria are also capable of sensing and responding to changes in their environment. These sensory responses are often independent of transport or metabolism and are mediated through membrane-spanning receptor proteins. We employed DNA-based pyrosequencing technology to investigate the changes in the intestinal microbiota of piglets weaned to a diet supplemented with either a natural sugar, lactose or an artificial sweetener (SUCRAM®, consisting of saccharin and neohesperidin dihydrochalcone (NHDC); Pancosma SA). The addition of either lactose or saccharin/NHDC to the piglets' feed dramatically increased the caecal population abundance of Lactobacillus, with concomitant increases in intraluminal lactic acid concentrations. This is the first report of the prebiotic-like effects of saccharin/NHDC, an artificial sweetener, being able to influence the commensal gut microbiota. The identification of the underlying mechanism(s) will assist in designing nutritional strategies for enhancing gut immunity and maintaining gut healt
Исследование влияния технологического процесса изготовления обмоток на дефектность корпусной изоляции асинхронных двигателей
В работе проведено исследование влияния колебаний режимов работы статорообмоточных станков WST-660 и пазоизолировочных станков ИПС-3 на дефектность корпусной изоляции. Получены математические модели дефектообразования в корпусной изоляции обмотки с учетом режимов работы технологического оборудования и качества материала корпусной изоляции в состоянии поставки. Установлено, что изменением режимов работы технологического оборудования можно добиться требуемого качества корпусной изоляции при максимальной производительности оборудования
Mapping warming reefs—An application of multibeam acoustic water column analysis to define threatened abalone habitat
Robust definition of the spatial extent of seafloor habitats and how they may be changing through time is a holy grail for ecosystem management, particularly if an ecosystem is approaching a tipping point beyond which irreversible changes may occur. Here we generate and explore a new data set for the management of warming reefs in eastern Tasmania, Australia that will significantly improve the baseline maps required for fine-scaled spatial modelling and management that is, both robust at regional scales and is highly resolved within the water column. This procedure enabled the relative density of kelp vegetation to be identified in a region that is being overwhelmed by the range extension of a destructive grazer, the Longspined Sea Urchin, Centrostephanus rodgersii. We present a new online tool to visualize multibeam water column acoustic data as surfaces of kelp density at high resolution (50 cm) scale over seafloor terrain maps (spanning a total straight-line distance of 594 km and a total area of 29.14 km2) to reveal the types of reef structure on the East Coast of Tasmania where abalone habitat is threatened by kelp loss
Eight Weeks Later - The Unprecedented Rise of 3D Printing during the COVID-19 Pandemic : a Case Study, Lessons Learned, and Implications on the Future of Global Decentralized Manufacturing
The eruption of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (corona virus disease, COVID-19) in Wuhan, China, and its global spread has led to an exponentially growing number of infected patients, currently exceeding over 6.6 million and over 390,000 deaths as of the 5th of June 2020. In this pandemic situation, health systems have been put under stress, and the demand for personal protective equipment (PPE) exceeded the delivery capabilities of suppliers. To address this issue, 3D printing was identified as a possible solution to quickly produce PPE items such as face shields, mask straps, masks, valves, and ear savers. Around the world, companies, universities, research institutions, and private individuals/hobbyists stepped into the void, using their 3D printers to support hospitals, doctors, nursing homes, and even refugee camps by providing them with PPE. In Germany, the makervsvirus movement took up the challenge and connected thousands of end users, makers, companies, and logistic providers for the production and supply of face shields, protective masks, and ear savers. The Karlsruhe Institute of Technology (KIT) also joined the makervsvirus movement and used its facilities to print headbands for face shield assemblies and ear savers. Within this paper, the challenges and lessons learned from the quick ramp up of a research laboratory to a production site for medium-sized batches of PPE, the limitations in material supply, selection criteria for suitable models, quality measures, and future prospects are reported and conclusions drawn
Selective detection of nitroexplosives using molecular recognition within self-assembled plasmonic nanojunctions
We demonstrate that the reproducibility of sensors for nitroaromatics based on surface-enhanced Raman spectroscopy (SERS) can be significantly improved via a hierarchical aqueous self-assembly approach mediated by the multifunctional macrocyclic molecule cucurbit[7]uril (CB[7]). Our approach is enabled by the novel host–guest complexation between CB[7] and an explosive marker 2,4-dinitrotoluene (DNT). Binding studies are performed using experimental and computation techniques to quantify key binding parameters for the first time. This supramolecular complexation allows DNT to be positioned in close proximity to the plasmonic hotspots within aggregates of CB[7] and gold nanoparticles, resulting in significant SERS signals with a detection limit of ∼1 μM. The supramolecular ensemble is selective against a structurally similar nitroaromatics owing to the molecular-recognition nature of the complexation as well as tolerant against the presence of model organic contaminants that bind strongly to the SERS substrates
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