Jackson Roehrig

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Many countries are adopting water policies and legislative instruments for water management in conformance to the agenda 21. According to this agenda, the use and protection of surface water and groundwater are coordinated at a river basin level. The success of river basin management systems relies upon coordinated actions, including provision of and access(More)
We have constructed an image-stabilization system that measures wave-front tilt over a telescope aperture that is due to atmospheric turbulence. This system uses small features on the Sun as point sources. The wave-front tilt power spectral density has been measured with this system out to more than 500 Hz. The spectra show three distinct asymptotic slopes(More)
In this paper, the water level fluctuations of eight Ethiopian Rift Valley lakes were analyzed for their hydrological stability in terms of water level dynamics and their controlling factors. Long-term water balances and morphological nature of the lakes were used as bases for the analyses. Pettit’s homogeneity test and Mann–Kendall trend analysis were(More)
Introduction Guarani Aquifer System (SAG) is the formal denomination for a transboundary aquifer underlying four countries (Argentina, Brazil, Paraguay and Uruguay) in South America. Due to its strategic importance, a joint research project aiming for sustainable management and preservation of the aquifer was initiated by the four neighbour countries(More)
A large cylindrical drift chamber has been constructed for the,MARK III detector at SPEAR. The inner layer has a high density of sense wires for the measurement of kinks, vees, and dE/dx. The outer layers have a cell design with three sense wires, giving uniform drift behavior and left/right ambiguity resolution within a cell. The chamber has both current(More)
Lake Hawassa is a topographically closed lake in the Central Main Ethiopian Rift Valley. The water level of this lake has been reported to dramatically rise without falling back to the original level. The cause of this rise is not yet sufficiently investigated and subjected to this study. This study argues that the general variability in the lake level and(More)
Measurements of the branching ratios of ten Cabibbo suppressed hadronic weak decays of the II+ and Do are presented from data collected with the Mark III detector at SPEAR. In addition to the previously observed channels Do --) K-K+ and T-T+, we report new measurements of Do + r-rr+~O and ?r-n+rr-7rlr+; and D+ + I?OK+ , TOT+, I?*‘(892)K+, r&r+, K-K+x+, and(More)
Hydromorphological deficits of European rivers and creeks are a major reason for the fact that the good ecological status stipulated by the European Water Framework Directive has not been achieved. In order to overcome these deficits, the German state of North Rhine-Westphalia calls for the implementation of a radiating effect concept to facilitate the(More)
Tw point ed fro o s, wj. amphtude f propor tional to (R'), the mean-square K' charge radius. The normalization problem is solved by the double-beam technique, ""i.e., by observing the two butions. In the naive, nonrelativistic quark model (R2) should be finite and negative, since the two (s and d) quarks orbit about their center of mass, with the lighter d(More)
Pairs of 7 leptons produced at fi = 3.77 GeV have been studied in ep, ee and pp final states. The leptonic branching ratios have been measured to be B(r ---) evv) = 18.2 f 0.7 f 0.5% and B( 7 + IVY) = 18.0 f 1.0 f 0.6%. Limits have been set for the two-body decays 7 -+ eG and 7 + pG, where G is a light Goldstone boson. Submitted to Physical Review Letters *(More)