2,680 research outputs found
General procedure to initialize the cyclic soil water balance by the Thornthwaite and Mather method
The original Thornthwaite and Mather method, proposed in 1955 to calculate a climatic monthly cyclic soil water balance, is frequently used as an iterative procedure due to its low input requirements and coherent estimates of water balance components. Using long term data sets to establish a characteristic water balance of a location, the initial soil water storage is generally assumed to be at field capacity at the end of the last month of the wet season, unless the climate is (semi-) arid when the soil water storage is lower than the soil water holding capacity. To close the water balance, several iterations might be necessary, which can be troublesome in many situations. For (semi-) arid climates with one dry season, Mendon a derived in 1958 an equation to quantify the soil water storage monthly at the end of the last month of the wet season, which avoids iteration procedures and closes the balance in one calculation. The cyclic daily water balance application is needed to obtain more accurate water balance output estimates. In this note, an equation to express the water storage for the case of the occurrence of more than one dry season per year is presented as a generalization of Mendon a's equation, also avoiding iteration procedures
A Simple, Quick, and Precise Procedure for the Determination of Water in Organic Solvents
A procedure for the UV/VIS-spectroscopic determination of water by the use of a solvatochromic pyridiniumphenolate betaine is given. The water content of organic solvents is calculated by a two parameter equation from λmax of the dye. A typical, detection limit is of the order of 1 mg in 1 ml solvent for routine spectrometers. The parameters for the determination of water are given for a number of commonly used solvents
Glucocorticoids delivered by inorganicâorganic hybrid nanoparticles mitigate acute graftâversusâhost disease and sustain graftâversusâleukemia activity
Glucocorticoids (GCs) are widely used to treat acute graftâversusâhost disease (aGvHD) due to their immunosuppressive activity, but they also reduce the beneficial graftâversusâleukemia (GvL) effect of the allogeneic T cells contained in the graft. Here, we tested whether aGvHD therapy could be improved by delivering GCs with the help of inorganicâorganic hybrid nanoparticles (IOHâNPs) that preferentially target myeloid cells. IOHâNPs containing the GC betamethasone (BMPâNPs) efficiently reduced morbidity, mortality, and tissue damage in a totally MHC mismatched mouse model of aGvHD. Therapeutic activity was lost in mice lacking the GC receptor (GR) in myeloid cells, confirming the cell type specificity of our approach. BMPâNPs had no relevant systemic activity but suppressed cytokine and chemokine gene expression locally in the small intestine, which presumably explains their mode of action. Most importantly, BMPâNPs delayed the development of an adoptively transferred B cell lymphoma better than the free drug, although the overall incidence was unaffected. Our findings thus suggest that employing IOHâNPs could diminish the risk of relapse associated with GC therapy of aGvHD patients while still allowing to efficiently ameliorate the disease
Determinação de coeficientes de cultura para o milho durante um experimento de evapotranspiração em um oxisol do Brasil
Soil water balance components were measured during two periods (from 1989 to 1991) on a Dark Red Latosol (oxisol) in Piracicaba,SP, Brazil. The change in soil water storage and the soil water fluxes at the lower limit of the rooting zone were calculated for a transect of 25 observation plots. Hydraulic head gradients were determined by tensiometer measurements. Soil water flux densities were estimated through Darcy's equation. The actual evapotranspiration of the crops and weeds and the actual evaporation of bare soil were obtained from the water balance equation and this for two periods under different crop rotations. For the first period the sequence was bare soil-corn-weeds and for the second period it was stubble mulch-weeds-corn. For assessing the crop coefficients the potential evapotranspiration was calculated according to two different methods. The first method was based on the modified Penman equation with grass as a reference crop, to obtain this way reference coefficients, and the second method was based on the pan "A" evaporation data in order to obtain pan coefficients. These coefficients were compared with the tabulated crop coefficients. In general when there was no shortage of water during the corn growth, the crop coefficients k c"A" and k c ref were very close to the k c values.Os componentes do balanço hĂdrico foram medidos durante dois perĂodos (de 1989 a 1991) em terra roxa estruturada, em Piracicaba,SP, Brasil. As variaçÔes de armazenamento de ĂĄgua e os fluxos de ĂĄgua no solo no limite inferior da zona radicular foram calculados para uma transeção de 25 parcelas experimentais. Gradientes hidrĂĄulicos foram determinados por meio de medidas tensiomĂ©tricas. Densidades de fluxo de ĂĄgua foram estimadas atravĂ©s da equação de Darcy. A evapotranspiração atual das culturas e das ervas daninhas e a evaporação atual do solo nĂș foram obtidas da equação do balanço hĂdrico, para dois perĂodos, sob diferentes rotaçÔes de cultura. Para o primeiro perĂodo a seqĂŒĂȘncia foi solo nĂș - milho - ervas daninhas e para o segundo cobertura morta - ervas daninhas - milho. Para determinar os coeficientes de cultura, a evapotranspiração potencial foi calculada por dois mĂ©todos. O primeiro foi baseado na equação de Penman modificada, com a grama como cobertura de referĂȘncia, obtendo assim os coeficientes de referĂȘncia, e o segundo baseado no tanque de evaporação tipo classe "A", obtendo os coeficientes de tanque. Estes coeficientes foram comparados com os coeficientes de cultura tabulados. De uma forma geral, em perĂodos sem falta de ĂĄgua para a cultura, os coeficientes de referĂȘncia e de tanque se assemelharam bastante aos coeficientes de cultura
Noise Thresholds for Higher Dimensional Systems using the Discrete Wigner Function
For a quantum computer acting on d-dimensional systems, we analyze the
computational power of circuits wherein stabilizer operations are perfect and
we allow access to imperfect non-stabilizer states or operations. If the noise
rate affecting the non-stabilizer resource is sufficiently high, then these
states and operations can become simulable in the sense of the Gottesman-Knill
theorem, reducing the overall power of the circuit to no better than classical.
In this paper we find the depolarizing noise rate at which this happens, and
consequently the most robust non-stabilizer states and non-Clifford gates. In
doing so, we make use of the discrete Wigner function and derive facets of the
so-called qudit Clifford polytope i.e. the inequalities defining the convex
hull of all qudit Clifford gates. Our results for robust states are provably
optimal. For robust gates we find a critical noise rate that, as dimension
increases, rapidly approaches the the theoretical optimum of 100%. Some
connections with the question of qudit magic state distillation are discussed.Comment: 14 pages, 1 table; Minor changes vs. version
Dispersion of the high-energy phonon modes in NdCeCuO
The dispersion of the high-energy phonon modes in the electron doped
high-temperature superconductor NdCeCuO has been studied
by inelastic neutron scattering. The frequencies of phonon modes with Cu-O
bond-stretching character drop abruptly when going from the Brillouin zone
center along the [100]-direction; this dispersion is qualitatively similar to
observations in the hole-doped cuprates. We also find a softening of the
bond-stretching modes along the [110]-direction but which is weaker and
exhibits a sinusoidal dispersion. The phonon anomalies are discussed in
comparison to hole-doped cuprate superconductors and other metallic
perovskites
Scalability of quantum computation with addressable optical lattices
We make a detailed analysis of error mechanisms, gate fidelity, and
scalability of proposals for quantum computation with neutral atoms in
addressable (large lattice constant) optical lattices. We have identified
possible limits to the size of quantum computations, arising in 3D optical
lattices from current limitations on the ability to perform single qubit gates
in parallel and in 2D lattices from constraints on laser power. Our results
suggest that 3D arrays as large as 100 x 100 x 100 sites (i.e.,
qubits) may be achievable, provided two-qubit gates can be performed with
sufficiently high precision and degree of parallelizability. Parallelizability
of long range interaction-based two-qubit gates is qualitatively compared to
that of collisional gates. Different methods of performing single qubit gates
are compared, and a lower bound of is determined on the
error rate for the error mechanisms affecting Cs in a blue-detuned
lattice with Raman transition-based single qubit gates, given reasonable limits
on experimental parameters.Comment: 17 pages, 5 figures. Accepted for publication in Physical Review
Applied Remote Sensing Program (ARSP)
There are no author-identified significant results in this report
Entangling flux qubits with a bipolar dynamic inductance
We propose a scheme to implement variable coupling between two flux qubits
using the screening current response of a dc Superconducting QUantum
Interference Device (SQUID). The coupling strength is adjusted by the current
bias applied to the SQUID and can be varied continuously from positive to
negative values, allowing cancellation of the direct mutual inductance between
the qubits. We show that this variable coupling scheme permits efficient
realization of universal quantum logic. The same SQUID can be used to determine
the flux states of the qubits.Comment: 4 pages, 4 figure
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