1,275 research outputs found

    Solid-state electronic spin coherence time approaching one second

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    Solid-state electronic spin systems such as nitrogen-vacancy (NV) color centers in diamond are promising for applications of quantum information, sensing, and metrology. However, a key challenge for such solid-state systems is to realize a spin coherence time that is much longer than the time for quantum spin manipulation protocols. Here we demonstrate an improvement of more than two orders of magnitude in the spin coherence time (T2T_2) of NV centers compared to previous measurements: T20.5T_2 \approx 0.5 s at 77 K, which enables 107\sim 10^7 coherent NV spin manipulations before decoherence. We employed dynamical decoupling pulse sequences to suppress NV spin decoherence due to magnetic noise, and found that T2T_2 is limited to approximately half of the longitudinal spin relaxation time (T1T_1) over a wide range of temperatures, which we attribute to phonon-induced decoherence. Our results apply to ensembles of NV spins and do not depend on the optimal choice of a specific NV, which could advance quantum sensing, enable squeezing and many-body entanglement in solid-state spin ensembles, and open a path to simulating a wide range of driven, interaction-dominated quantum many-body Hamiltonians

    Managing Change: Considering the Relevance of Place Identity for Planning in British Columbia?s Communities in Transition. An Applied Research Case Study of Three Vancouver Island Communities.

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    Beginning in 1980, large forestry corporations in British Columbia began to rapidly downsize and restructure their operations. The combination of volatile international market conditions, increasing demands for environmental conservation, First Nation?s land claims, higher stumpage rates, American protectionism, a declining timber supply, and introduction of labor saving technologies, made it no longer profitable for these companies to employ large numbers of workers under a Fordist organizational structure. The tremendous job losses seriously compromised the sustainability of forestry dependent communities throughout the province. The responses from forestry based communities in B. C. have been diverse. Some have chosen to take a more passive approach and have become bedroom communities to larger urban centers or retirement destinations. Others have actively pursued economic diversification through increased entrepreneurial activities. No matter which alternative individual communities have chosen to pursue, it is evident that they are all undergoing a significant transformation. This exploratory study examines how the identity (or image) of these places has evolved, and investigates the impact this has had on local residents. The three Vancouver Island communities of Chemainus, Sooke, and Port Alberni have been selected as case studies. A variety of quantitative and qualitative research methods are employed including a resident survey, personal interviews, and review of real estate guides and promotional materials. Overall the findings suggest that the identity associated with each case study community has both positively and negatively perceived elements. With a greater appreciation for these elements, it was possible for the researcher to make a variety of justifiable recommendations to improve current planning policies and processes, in each of the case studies, which will help them build a stronger, more positive image, and therefore become healthier, more viable, and sustainable communities. By emphasizing the significance of identity for community planning, and by outlining the participatory methods necessary to conduct an in depth identity investigation, this study also paves the way for future investigations on other British Columbia communities in transition and for the widespread use of the principle of identity as a contributory decision-making strategy in the planning profession

    Can cattle handling affect morbidity?

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    Urban Heritage Surabaya

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    [No abstract available

    De architectuur en stedebouw in de West-Indische archipel. Een verkenning vanuit Curaçao

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    Jakarta's Urban Heritage. Herstel van het stedelijk geheugen van Kota

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    If guide-lines for re-planning stay out, the structure and form of Old Batavia will be wiped out for good. At present an ambitious project of the Indonesian and Dutch ministries to the reorganization of Jakarta's northern border compares the meaning of Kota as a historic nucleus with her value to Jakarta the metropolis. The urban heritage research divides the old town into parcels and lots. The historic features of these parcels and fragments of buildings, the present morphological characteristic and functional potencies of buildings and urban space to renewal and urban function were analyzed. The historic value of the plan and its contribution to the historic town as a whole has been weighed. This way every block was researched after three themes: historic development and background: present situation both and functional and morphological characteristic. The program of the preservation of Kota as a historic town and on the other hand the re-organization after a revised plan with a high future value are both meant to revitalize the old town. This revitalization also means that the raising of the functional value of the old town is coupled to a high value of experience of space and buildings, which experience is almost completely defined by Kota's historic character. To the preservation of Kota as a historic town strengthening of the original plan is necessary. The building-blocks however must preserve possibilities for development at the same time. In a historic basic or memory map of Kota the historic plan, objects and historic features have been made visible. These aspects are the starting point of the program for a revised town plan. Also the morphological characteristics of space and buildings are important. The contribution of each of the town-blocks to the coherent whole hereby is central. Because of Kota's historic orientation to the sea as an unmistakable datum of her urban identity the block of Pasar Ikan plays a vital role in the town plan. To be able to determine the nature and scope of the functional transformations which are necessary for a durable revitalization, Kota's role on the level of the metropolis Jakarta must be considered anew. Kota's geographic situation contains unique possibilities. The present gudang or warehouse-function of Kota will have to be replaced by a more dynamic and productive usage. Regional reflection on Kota will have to reconsider the meaning of Kota as a historic nucleus in the metropolis Jakarta and within the continually extending megatown JABOTABEK. Next to the two historic axes (one of these the axe of the completed fortification Kota), the third early 19th century axe can gain in meaning as a spatial identity-axe to a growing Jabotabek. This axe also has potency to be developed into a program for cultural tourism to the former islands of the Dutch United East-Indian Company

    Anaplasmosis in Beef Cattle

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    8 pp., 2 tablesAnaplasmosis is an infectious disease of cattle that destroys red blood cells. The disease is caused by a parasite, Anaplasma marginale, found in the red blood cells of infected cattle. It can be transmitted from infected to healthy cattle by insects or surgical instruments. The stages of the disease, control programs, and methods of treating and halting an outbreak are discussed

    Texas Adapted Genetic Strategies for Beef Cattle X: Frame Score, Frame Size, and Weight

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    4 pp., 4 photos, 1 tableBody size is an important genetic factor in beef cattle production. Size is most accurately estimated by considering several factors, such as weight, skeletal size and body condition. Frame Scores are a way of estimating skeletal size based on hip height