Water Conservation with Urban Landscape Plants

Water shortages are a common problem in much of the southwest. Increasing urbanization and increasing population places greater demands on dwindling water supplies. Over half of the water used in urban areas of the southwest is used in the irrigation of landscapes. To help cope with increased urban water demands and low water supplies, research was conducted from March 1981 to July 1983 at The Texas Agricultural Experiment Station at Dallas to gain information relative to consumptive water use by native and non-native landscape plants. Twenty weighing lysimeters were constructed and installed and plants established in the lysimeters and adjacent areas. The lysimeters were made from 0.6 X 0.9 m undisturbed cores of Austin silty clay soil. Plants used in the lysimeter study were buffalograss, St. Augustine grass, cenizo, boxwood and Texas barberry. All plants are native to Texas except boxwood and St. Augustine grass. Four lysimeters were planted to each plant type. This allowed two moisture levels and two replications of each plant type. There was no difference in water use by St. Augustine grass and buffalo grass during the year of establishment. Daily water use ranged from 0.49 to 0.08 cm per day but was generally 50% class A pan evaporation. St. Augustine grass used 0.03 cm/day more water than buffalo grass during 1982. -Irrigation treatments used in 1982 did not influence water use by either grass type but buffalo grass retained higher quality under dry treatment (irrigated at 0.40 bar moisture tension) than St. Augustine grass. Water use from May to July 1983 was highest (of all treatments) by St. Augustine grass when irrigated at 0.25 bar soil moisture tension at 76 cm depth and lowest (of all treatments) by buffalograss when irrigated at 0.75 bar soil moisture tension at 76 cm depth. Application of 50% class A pan evaporation each week appears to be an acceptable guideline for irrigation of either turfgrass but research should be conducted over a longer time period to obtain more specific guidelines for each grass species. Water use by shrubs in lysimeters was variable and not influenced by plant type during the period of establishment (Fall 1981). During 1982 water use was influenced more by plant size than by specie or water level. Cenizo had much faster growth rate than the other shrubs in the study. Water use by container grown plants indicated that cenizo had higher water use efficiency than boxwood or Indian Hawthorn. Water use was determined for several native shrubs and of the ones compared, Texas barberry appeared to have the most promise for use in water conserving landscapes

Resposta de cultivares de tomateiro para processamento industrial a fertirrigacao por gotejamento subterraneo.

bitstream/item/103100/1/pa-6.pd

Water Conservation with Urban Landscape Plants

Water shortages are a common problem in much of the southwest. Increasing urbanization and increasing population places greater demands on dwindling water supplies. Over half of the water used in urban areas of the southwest is used in the irrigation of landscapes. To help cope with increased urban water demands and low water supplies, research was conducted from March 1981 to July 1983 at The Texas Agricultural Experiment Station at Dallas to gain information relative to consumptive water use by native and non-native landscape plants. Twenty weighing lysimeters were constructed and installed and plants established in the lysimeters and adjacent areas. The lysimeters were made from 0.6 X 0.9 m undisturbed cores of Austin silty clay soil. Plants used in the lysimeter study were buffalograss, St. Augustine grass, cenizo, boxwood and Texas barberry. All plants are native to Texas except boxwood and St. Augustine grass. Four lysimeters were planted to each plant type. This allowed two moisture levels and two replications of each plant type. There was no difference in water use by St. Augustine grass and buffalo grass during the year of establishment. Daily water use ranged from 0.49 to 0.08 cm per day but was generally 50% class A pan evaporation. St. Augustine grass used 0.03 cm/day more water than buffalo grass during 1982. -Irrigation treatments used in 1982 did not influence water use by either grass type but buffalo grass retained higher quality under dry treatment (irrigated at 0.40 bar moisture tension) than St. Augustine grass. Water use from May to July 1983 was highest (of all treatments) by St. Augustine grass when irrigated at 0.25 bar soil moisture tension at 76 cm depth and lowest (of all treatments) by buffalograss when irrigated at 0.75 bar soil moisture tension at 76 cm depth. Application of 50% class A pan evaporation each week appears to be an acceptable guideline for irrigation of either turfgrass but research should be conducted over a longer time period to obtain more specific guidelines for each grass species. Water use by shrubs in lysimeters was variable and not influenced by plant type during the period of establishment (Fall 1981). During 1982 water use was influenced more by plant size than by specie or water level. Cenizo had much faster growth rate than the other shrubs in the study. Water use by container grown plants indicated that cenizo had higher water use efficiency than boxwood or Indian Hawthorn. Water use was determined for several native shrubs and of the ones compared, Texas barberry appeared to have the most promise for use in water conserving landscapes

Dynamic Mean-Field Glass Model with Reversible Mode Coupling and Trivial Hamiltonian

Often the current mode coupling theory (MCT) of glass transitions is compared with mean field theories. We explore this possible correspondence. After showing a simple-minded derivation of MCT with some difficulties we give a concise account of our toy model developed to gain more insight into MCT. We then reduce this toy model by adiabatically eliminating rapidly varying velocity-like variables to obtain a Fokker-Planck equation for the slowly varying density-like variables where diffusion matrix can be singular. This gives a room for nonergodic stationary solutions of the above equation.Comment: 9 pages, contribution to the Proceedings of the Merida Satellite Meeting to STATPHYS21 (Merida, Mexico, July 9-14, 2001). To appear in J. Phys. Condens. Matte

Kinetically driven glassy transition in an exactly solvable toy model with reversible mode coupling mechanism and trivial statics

We propose a toy model with reversible mode coupling mechanism and with trivial Hamiltonian (and hence trivial statics). The model can be analyzed exactly without relying upon uncontrolled approximation such as the factorization approximation employed in the current MCT. We show that the model exhibits a kinetically driven transition from an ergodic phase to nonergodic phase. The nonergodic state is the nonequilibrium stationary solution of the Fokker-Planck equation for the distribution function of the modelComment: 10 pages, 1 figure, contribution to the Proceedings of the Barcelona Workshop 'Glassy Behavior of Kinetically Constrained Models'. To appear in J. Phys. Condens. Matte

Low Temperature Anomaly in Mesoscopic Kondo Wires

We report the observation of an anomalous magnetoresistance in extremely dilute quasi-one-dimensional AuFe wires at low temperatures, along with a hysteretic background at low fields. The Kondo resistivity does not show the unitarity limit down to the lowest temperature, implying uncompensated spin states. We suggest that the anomalous magnetoresistance may be understood as the interference correction from the accumulation of geometric phase in the conduction electron wave function around the localized impurity spin.Comment: Four pages, five figure

On the relevance of chaos for halo stars in the solar neighbourhood

We show that diffusion due to chaotic mixing in the neighbourhood of the Sun may not be as relevant as previously suggested in erasing phase space signatures of past Galactic accretion events. For this purpose, we analyse solar neighbourhood-like volumes extracted from cosmological simulations that naturally account for chaotic orbital behaviour induced by the strongly triaxial and cuspy shape of the resulting dark matter haloes, among other factors. In the approximation of an analytical static triaxial model, our results show that a large fraction of stellar halo particles in such local volumes have chaos onset times (i.e. the time-scale at which stars commonly associated with chaotic orbits will exhibit their chaotic behaviour) significantly larger than a Hubble time. Furthermore, particles that do present a chaotic behaviour within a Hubble time do not exhibit significant diffusion in phase space.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plat

Granular-cell tumor of trachea masquerading as hurthle-cell neoplasm on fine-needle aspirate: A case report

We report on a case of extraluminal tracheal granular-cell tumor which was interpreted as a Hurthle-cell neoplasm of the thyroid on fine-needle aspirate. Review of the literature reveals only one other such case. The patient was a 35-yr-old female who presented with an enlarged thyroid. Aspiration cytology revealed a syncytium of cells with abundant granular cytoplasm interpreted as a thyroid follicular neoplasm with Hurthle-cell change. However, histology of the resection specimen with immunohistochemistry confirmed it as a granular-cell tumor. The cytologic differential diagnosis of neoplasms with oncocytoid cytoplasm in and around the thyroid should include granular-cell tumor of the trachea. Diagn. Cytopathol. 22:379–382, 2000. © 2000 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/35305/1/10_ftp.pd

First experimental evidence of one-dimensional plasma modes in superconducting thin wires

We have studied niobium superconducting thin wires deposited onto a SrTiO$_{3}$ substrate. By measuring the reflection coefficient of the wires, resonances are observed in the superconducting state in the 130 MHz to 4 GHz range. They are interpreted as standing wave resonances of one-dimensional plasma modes propagating along the superconducting wire. The experimental dispersion law, $\omega$ versus $q$, presents a linear dependence over the entire wave vector range. The modes are softened as the temperature increases close the superconducting transition temperature. Very good agreement are observed between our data and the dispersion relation predicted by Kulik and Mooij and Sch\"on.Comment: Submitted to Physical review Letter

The Geometry of Integrable and Superintegrable Systems

The group of automorphisms of the geometry of an integrable system is considered. The geometrical structure used to obtain it is provided by a normal form representation of integrable systems that do not depend on any additional geometrical structure like symplectic, Poisson, etc. Such geometrical structure provides a generalized toroidal bundle on the carrier space of the system. Non--canonical diffeomorphisms of such structure generate alternative Hamiltonian structures for complete integrable Hamiltonian systems. The energy-period theorem provides the first non--trivial obstruction for the equivalence of integrable systems