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Topic Review
Unbiunium
Check temperatures Ubu: no input for C, K, F. Check temperatures Ubu: no input for C, K, F. Unbiunium, also known as eka-actinium or simply element 121, is the hypothetical chemical element with symbol Ubu and atomic number 121. Unbiunium and Ubu are the temporary systematic IUPAC name and symbol respectively, until a permanent name is decided upon. In the periodic table of the elements, it is expected to be the first of the superactinides, and the third element in the eighth period: analogously to lanthanum and actinium, it could be considered the fifth member of group 3 and the first member of the fifth-row transition metals. It has attracted attention because of some predictions that it may be in the island of stability, although newer calculations expect the island to actually occur at a slightly lower atomic number, closer to copernicium and flerovium. Unbiunium has not yet been synthesized. Nevertheless, because it is only three elements away from the heaviest known element, oganesson (element 118), its synthesis may come in the near future; it is expected to be one of the last few reachable elements with current technology, and the limit may be anywhere between element 120 and 124. It will also likely be far more difficult to synthesize than the elements known so far up to 118, and still more difficult than elements 119 and 120. The team at RIKEN in Japan has plans to attempt the synthesis of element 121 in the future after its attempts on elements 119 and 120. The position of unbiunium in the periodic table suggests that it would have similar properties to its lighter congeners, scandium, yttrium, lanthanum, and actinium; however, relativistic effects may cause some of its properties to differ from those expected from a straight application of periodic trends. For example, unbiunium is expected to have a s2p valence electron configuration instead of the s2d of its lighter congeners in group 3, but this is not expected to significantly affect its chemistry, which is predicted to be that of a normal group 3 element; it would on the other hand significantly lower its first ionisation energy beyond what would be expected from periodic trends.
  • 5.7K
  • 25 Oct 2022
Topic Review
Unbibium
Unbibium /uːnˈbɪbiəm/, also known as eka-thorium or simply element 122, is the currently hypothetical chemical element in the periodic table with the placeholder symbol of Ubb and atomic number 122. Unbibium and Ubb are the temporary systematic IUPAC name and symbol respectively, until a permanent name is decided upon. In the periodic table of the elements, it is expected to follow unbiunium as the second element of the superactinides, or the g-block and the fourth element of the 8th period. It has attracted recent attention, for similarly to unbiunium, it is expected to fall within the range of the island of stability. Despite many attempts, unbibium has not yet been synthesized, and therefore no natural isotopes have been found to exist. It is currently predicted that it has a g-orbital, the second element of which to have such besides unbiunium, which also has yet to be synthesized. It will most likely require nuclear fission to be produced artificially. In 2008, it was claimed to have been discovered in natural thorium samples but that claim has now been dismissed by recent repetitions of the experiment using more accurate techniques.
  • 3.3K
  • 29 Nov 2022
Topic Review
Unbiased Expectation Theory
Unbiased expectation theory (UET), which posits that long-term interest rates are determined by the market’s expectations of future short-term interest rates, is a fundamental concept in the field of fixed-income securities. According to the expectation hypothesis, forward interest rates should be unbiased estimates of expected future spot interest rates.
  • 566
  • 09 Jan 2024
Topic Review
Unbalanced Oil and Vinegar
In cryptography, the Unbalanced Oil and Vinegar (UOV) scheme is a modified version of the Oil and Vinegar scheme designed by J. Patarin. Both are digital signature schemes. They belong to the group of multivariate cryptography. The security of this signature scheme is based on an NP-hard mathematical problem. To create and validate signatures a minimal quadratic equations system must be solved. Solving m equations with n variables is an NP-hard problem, which means the problem is almost certainly difficult to solve efficiently in the worst case, even when using a quantum computer. While the problem is easy if m is either much much larger or much much smaller than n, importantly for cryptographic purposes, the problem is thought to be difficult in the average case when m and n are nearly equal, even when using a quantum computer. As a result, a number of signature schemes have been devised based on multivariate equations with the goal of achieving quantum resistant signatures.
  • 426
  • 17 Nov 2022
Topic Review
Unawareness of Chronic Kidney Disease in Germany
Chronic kidney disease (CKD) is associated with an increased risk for cardiovascular events, hospitalizations, end stage renal disease and mortality. Main risk factors for CKD are diabetes, hypertension, and older age. Although CKD prevalence is about 10%, awareness for CKD is generally low in patients and physicians, hindering early diagnosis and treatment. We analyzed baseline data of 3305 participants with CKD Stages 1–4 from German cohorts and registries collected in 2010. Prevalence of CKD unawareness and prevalence ratios (PR) (each with 95%-confidence intervals) were estimated in categories of age, sex, CKD stages, BMI, hypertension, diabetes and other relevant comorbidities. We used a log-binomial regression model to estimate the PR for CKD unawareness for females compared to males adjusting for CKD stage and CKD risk factors. CKD unawareness was high, reaching 71% (68–73%) in CKD 3a, 49% (45–54%) in CKD 3b and still 30% (24–36%) in CKD4. Prevalence of hypertension, diabetes or cardiovascular comorbidities was not associated with lower CKD unawareness. Independent of CKD stage and other risk factors unawareness was higher in female patients (PR = 1.06 (1.01; 1.10)). Even in patients with CKD related comorbidities, CKD unawareness was high. Female sex was strongly associated with CKD unawareness. Guideline oriented treatment of patients at higher risk for CKD could increase CKD awareness. Patient–physician communication about CKD might be amendable. 
  • 442
  • 18 Nov 2021
Topic Review
UNAVCO
UNAVCO is a non-profit university-governed consortium that facilitates geoscience research and education using Geodesy. UNAVCO is funded by the National Science Foundation (NSF) and The National Aeronautics and Space Administration (NASA) to support geoscience research around the world. UNAVCO operates the GAGE Facility (Geodetic Facility for the Advancement of Geoscience) on behalf of the NSF and NASA. As a university-governed consortium, UNAVCO supports the goals of the academic scientific community. UNAVCO has 120 US academic members and supports over 110 organizations globally as associate members.
  • 650
  • 17 Nov 2022
Topic Review
Unabsorbed Slack Resources and Enterprise Innovation
In 1963, Cyert & March defined slack resources as “the difference between total resources needed by the enterprise organization to maintain the status quo and the resources actually possessed by the organization”. There exist different forms of slack resources, such as idle machinery and equipment, surplus cash, extra employees, and semi-finished products in processing.  Technological innovation plays an important role in the success of enterprises and it is a critical factor for them to gain strong short-term market performance and long-term competitive advantage. Due to long cycles, large investments, and high adjustment costs, adequate resource support is essential to ensure the sustainability of innovation activities.
  • 729
  • 13 Apr 2022
Topic Review
UN-SPIDER
UN-SPIDER ("United Nations Platform for Space-based Information for Disaster Management and Emergency Response") is a platform which facilitates the use of space-based technologies for disaster management and emergency response. It is a programme under the auspices of the United Nations Office for Outer Space Affairs (UNOOSA).
  • 278
  • 18 Oct 2022
Topic Review
UN Sustainable Development Goals
Reaching the land-related UN Sustainable Development Goals (SDGs) and similar goals articulated by the EU Green Deal (GD) by 2030 presents a major challenge and requires a pragmatic approach focused on joint learning by land users (mostly farmers), researchers and other stakeholders in “Living Labs” and system experiments at experimental farms of research organizations. Defining specific indicators and thresholds for ecosystem services in line with land-related SDGs is crucial to establish “Lighthouses” that can act as inspiring examples if they meet the various thresholds.
  • 622
  • 25 Apr 2022
Topic Review
UN and COVID-19: Economic Stimulation in Fragile States
United Nations support for fragile economies to overcome COVID-19's economic impact .
  • 536
  • 25 Nov 2021
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