Existing opportunities to adapt the Rio Grande/Bravo Basin Water Resources Allocation Framework

The study of the Rio Grande/Bravo (RGB) Basin water allocation demonstrates how the United States (U.S.) and Mexico have consolidated a transboundary framework based on water sharing. However, the water supply no longer meets the ever-increasing demand for water or the expectations of different stakeholders. This paper explores opportunities for an enhanced management regime that will address past problems and better examine how to balance demands for a precious resource and environmental needs. Based on an overview of the RGB Basin context and the water allocation framework, as well as a discussion on stakeholders’ ability to achieve solutions, this paper explores three key questions: (1) Does the current binational water allocation framework meet current and future human and environmental needs? (2) How can the U.S.-Mexico water allocation framework be adapted to balance social and environmental water demands so it can support and preserve the RGB Basin ecosystem? (3) What are the main opportunities to be explored for expanding the U.S.-Mexico water resources allocation framework? The U.S.-Mexico water resources framework is subject to broad interpretation and may be adapted to the circumstances taking the fullest advantage of its flexibility. Policy recommendations highlight the existing flexibility of the binational framework, the potential to move forward with an ad hoc institutional arrangement, and the creation of political will to achieve change through stakeholders recommendations

Growth in brine, at low temperature and different organic acids, of yeasts from table olives

The evolution of the main yeast species related to table olives (Pichia anomala, Pichia membranaefaciens, Pichia minuta, Saccharomyces cerevisiae, Candida diddensii, Candida famata, and Debaryomyces hansenii) at low temperature (7ºC) and different physico-chemical brine conditions was studied, using the log of the relative growth as response. In general, the NaCl concentration had a reduced effect, which was slightly greater at pH 3.5, although it was never significant. The effects of pH and type of acid were significant: the presence of acetic acid always diminished the yeast population with time; however the population was maintained, or even slightly increased, in the presence of lactic acid. Such effects were higher at pH 3.5 than at pH 4.0. The behavior of the yeast species was diverse. Sacch. cerevisiae, P. membranaefaciens, C. famata y Deb. hansenii disminished with time in 8% NaCl. The yeast population markedly decreased at pH 3.5, mainly in the case of Sacch. cerevisiae and C. famata. The presence of acetic acid decreased the yeast population in most species and always lead to a progressive diminution of it with time. No differences between species due to lactic acid was observed. These results can be of interest for the development of commercial presentations of table olives to be preserved at low temperature and with a reduced level of sodium.Se ha estudiado la evolución de las principales especies de levaduras relacionadas con las aceitunas de mesa (Pichia anomala, Pichia membranaefaciens, Pichia minuta, Saccharomyces cerevisiae, Candida diddensii, Candida famata , y Debaryomyces hansenii) a baja temperara (7ºC) y en diversas condiciones físico-químicas en las salmueras, utilizando el log del crecimiento relativo como respuesta. En general, la concentración de sal tiene un efecto muy limitado, que se aprecia algo más a pH 4, pero sin llegar a ser significativo. Los efectos del tipo de ácido y pH fueron significativos; la presencia de acético disminuye la población con el tiempo, mientras que con el láctico se mantiene e, incluso, se eleva ligeramente. Estos efectos se acentúan a pH 3,5. El comportamiento de cada levadura frente a las diferentes variables ha sido diverso. La población relativa de las especies Sacch. cerevisiae , P. membranaefaciens , C. famata y Deb. hansenii disminuyó con el tiempo en presencia del 8 % de NaCl. A pH 3,5 disminuye muy sensiblemente la población inicial en todos los casos, siendo tal influencia más destacada en Sacch. cerevisiae y C. famata. La presencia de acético disminuye de forma importante la población inicial inoculada en la mayoría de los casos y provocó siempre un descenso paulatino en las mismas. No se observó diferencias entre las especies debido al ácido láctico. Estos estudios pueden ser de interés para el desarrollo de presentaciones comerciales de aceitunas de mesa refrigeradas y con reducido nivel de sodio.Los autores desean expresar su gratitud a la CICYT (AGL2000-1539-CO2-01) y a la Unión Europea (FAIR-97-9526) por la financiación parcial de esta investigación.Peer reviewe

Crystal chemistry of type paulkerrite and establishment of the paulkerrite group nomenclature

A single-crystal structure determination and refinement has been conducted for the type specimen of paulkerrite. The structure analysis showed that the mineral has monoclinic symmetry, space group P21/c, not orthorhombic, Pbca, as originally reported. The unit-cell parameters are aCombining double low line10.569(2), bCombining double low line20.590(4), cCombining double low line12.413(2)Å, and βCombining double low line90.33(3)°. The results from the structure refinement were combined with electron microprobe analyses to establish the empirical structural formula A1[(H2O)0.98K0.02]ς1.00 A2K1.00 M1(Mg1.02Mn0.982+)ς2.00 M2(Fe1.203+Ti0.544+Al0.24Mg0.02)ς2.00 M3(Ti0.744+ Fe0.263+)ς1.00 (PO4)4.02X[O1.21F0.47(OH)0.32]ς2.00(H2O)10.3.95H2O, which leads to the end-member formula (H2O)KMg2Fe2Ti(PO4)4(OF)(H2O)10.4H2O. A proposal for a paulkerrite group, comprising orthorhombic members benyacarite, mantiennéite, pleysteinite, and hochleitnerite and monoclinic members paulkerrite and rewitzerite, has been approved by the International Mineralogical Association's Commission for New Minerals, Nomenclature and Classification. The general formulae are A2M12M22M3(PO4)4X2(H2O)10.4H2O and A1A2M12M22M3(PO4)4X2(H2O)10.4H2O for orthorhombic and monoclinic species, respectively, where ACombining double low lineK, H2O, (Combining double low linevacancy); M1Combining double low lineMn2+, Mg, Fe2+, Zn (rarely Fe3+); M2 and M3Combining double low lineFe3+, Al, Ti4+ (and very rarely Mg); XCombining double low lineO, OH, F. In monoclinic species, K and H2O show an ordering at the A1 and A2 sites, whereas O, (OH), and F show a disordering over the two non-equivalent X1 and X2 sites, which were hence merged as X2 in the general formula. In both monoclinic and orthorhombic species, a high degree of mixing of Fe3+, Al, and Ti occurs at the M2 and M3 sites of paulkerrite group members, making it difficult to get unambiguous end-member formulae from the structural determination of the constituents at individual sites. To deal with this problem an approach has been used that involves merging the compositions at the M2 and M3 sites and applying the site-total-charge method. The merged-site approach allows end-member formulae to be obtained directly from the chemical analysis without the need to conduct crystal-structure refinements to obtain the individual site species. Copyright

Перспективы развития фундаментальных наук: сборник научных трудов XI Международной конференция студентов и молодых ученых, г. Томск, 22-25 апреля 2014 г.

Сборник содержит труды участников XI Международной конференции студентов и молодых учёных "Перспективы развития фундаментальных наук". Включает доклады студентов и молодых ученых, представленные на секциях "физика", "химия", "математика", "технология", наноматериалы и нанотехнологии», "IT-технологии и электроника". В рамках секций представлены доклады студентов представленные для соискания стипендий по программе У.М.Н.И.К. Сборник представляет интерес для студентов, аспирантов, молодых ученых, преподавателей в области естественных наук и высшей математик

Crystal chemistry of type paulkerrite and establishment of the paulkerrite group nomenclature

A single-crystal structure determination and refinement has been conducted for the type specimen of paulkerrite. The structure analysis showed that the mineral has monoclinic symmetry, space group P21/c, not orthorhombic, Pbca, as originally reported. The unit-cell parameters are a=10.569(2), b=20.590(4), c=12.413(2) Å, and β=90.33(3)∘. The results from the structure refinement were combined with electron microprobe analyses to establish the empirical structural formula A1[(H2O)0.98K0.02]Σ1.00 A2K1.00 M1(Mg1.02Mn0.982+)Σ2.00 M2(Fe1.203+Ti0.544+Al0.24Mg0.02)Σ2.00 M3(Ti0.744+ Fe0.263+)Σ1.00 (PO4)4.02 X[O1.21F0.47(OH)0.32]Σ2.00(H2O)10 ⋅ 3.95H2O, which leads to the end-member formula (H2O)KMg2Fe2Ti(PO4)4(OF)(H2O)10 ⋅ 4H2O. A proposal for a paulkerrite group, comprising orthorhombic members benyacarite, mantiennéite, pleysteinite, and hochleitnerite and monoclinic members paulkerrite and rewitzerite, has been approved by the International Mineralogical Association's Commission for New Minerals, Nomenclature and Classification. The general formulae are A2M12M22M3(PO4)4X2(H2O)10 ⋅ 4H2O and A1A2M12M22M3(PO4)4X2(H2O)10 ⋅ 4H2O for orthorhombic and monoclinic species, respectively, where A= K, H2O, □ (= vacancy); M1 = Mn2+, Mg, Fe2+, Zn (rarely Fe3+); M2 and M3 = Fe3+, Al, Ti4+ (and very rarely Mg); X= O, OH, F. In monoclinic species, K and H2O show an ordering at the A1 and A2 sites, whereas O, (OH), and F show a disordering over the two non-equivalent X1 and X2 sites, which were hence merged as X2 in the general formula. In both monoclinic and orthorhombic species, a high degree of mixing of Fe3+, Al, and Ti occurs at the M2 and M3 sites of paulkerrite group members, making it difficult to get unambiguous end-member formulae from the structural determination of the constituents at individual sites. To deal with this problem an approach has been used that involves merging the compositions at the M2 and M3 sites and applying the site-total-charge method. The merged-site approach allows end-member formulae to be obtained directly from the chemical analysis without the need to conduct crystal-structure refinements to obtain the individual site species.</p

Alite calcium sulfoaluminate cement: chemistry and thermodynamics

Calcium sulfoaluminate (C$A) cement is a binder of increasing interest to the cement industry and is undergoing rapid development. Current formulations do not contain alite; however, alite calcium sulfoaluminate (a-C$A) cements can combine the favourable characteristics of Portland cement (PC) with those of C$A cement while also having a lower carbon dioxide footprint than the current generation of PC clinkers. This paper presents two results on the formation of a-C$A clinkers. The first is a thermodynamic study demonstrating that the production of a-C$A clinker is possible without the use of mineralisers, doping with foreign elements, or using multiple stages of heating. It is established that a-C$A clinker can be readily produced in a standard process by controlling the oxygen and sulfur dioxide fugacity in the atmosphere. This allows for the stabilisation of ye’elimite to the higher temperatures required for alite stability. The second result establishes that when using fluorine to mineralise a-C$A clinker production, the iron content in the clinker is also an important variable. Although the exact mechanism of alite stabilisation is not known, it is shown that alite formation increases with the combination of calcium fluoride and iron (III) oxide in the mix

State Capacity and the Environmental Investment Gap in Authoritarian States

We construct an n-period, constrained optimization model where the authoritarian ruler maximizes expected rents subject to budget constraint of available surplus. We show that the larger state capacity is in the previous period, the worse environmental quality will be in the next period: while infrastructural investment and environmental protection increase with state capacity, the former increases at a faster rate which enlarges the gap between the two?the environmental investment gap. Given infrastructural public goods typically damage the environment, the larger this gap is the worse the environmental quality would be. This follows from rulers? optimizing logic of equating marginal returns once we assume the declining marginal productivity of factors of production of surplus. We model three types of air and water pollutants in autocracies as a function of state capacity and other relevant variables. State capacity is associated with higher levels of all three types of pollutants

Deep Learning-Based Dose Prediction for Automated, Individualized Quality Assurance of Head and Neck Radiation Therapy Plans

PURPOSE: This study aimed to use deep learning-based dose prediction to assess head and neck (HN) plan quality and identify suboptimal plans. METHODS AND MATERIALS: A total of 245 volumetric modulated arc therapy HN plans were created using RapidPlan knowledge-based planning (KBP). A subset of 112 high-quality plans was selected under the supervision of an HN radiation oncologist. We trained a 3D Dense Dilated U-Net architecture to predict 3-dimensional dose distributions using 3-fold cross-validation on 90 plans. Model inputs included computed tomography images, target prescriptions, and contours for targets and organs at risk (OARs). The model\u27s performance was assessed on the remaining 22 test plans. We then tested the application of the dose prediction model for automated review of plan quality. Dose distributions were predicted on 14 clinical plans. The predicted versus clinical OAR dose metrics were compared to flag OARs with suboptimal normal tissue sparing using a 2 Gy dose difference or 3% dose-volume threshold. OAR flags were compared with manual flags by 3 HN radiation oncologists. RESULTS: The predicted dose distributions were of comparable quality to the KBP plans. The differences between the predicted and KBP-planned D CONCLUSIONS: Deep learning can predict high-quality dose distributions, which can be used as comparative dose distributions for automated, individualized assessment of HN plan quality