Making nutrition decisions in high-cost environments

Take home messages • At average fertiliser costs, return on investment to nitrogen applications exceed 5:1, i.e. every dollar spent on nitrogen results in $5 of additional profit • When N prices double, growers are still receiving$2.10 in profit for every dollar spent on nitrogen, and at triple the cost nitrogen is still expected to return $0.85 in additional profit for every dollar spent • With higher N prices profitable N responses to winter cereals are only expected under favourable grain prices or seasonal conditions • Soil testing and precision/variable nutrient application become more valuable as nutrition costs rise

1996 USCID water management conference

Presented at Competing interests in water resources - searching for consensus: proceedings from the USCID water management conference held on December 5-7, 1996 in Las Vegas, Nevada.Jordan does not have a water supply sufficient for current and future irrigation, domestic, and industrial needs. The Jordan Valley Authority (JVA) provides irrigation water to about 23,000 hectares (57,000 acres) of land in the Jordan Valley where a variety of crops are raised. Water supplied from the Jordan River and its tributaries is limited, and storage is very limited. Domestic and industrial water supplies are also taken from the river, and demands will increase as the population and industrial base expands. Per capita water use is very low, so opportunities to conserve domestic water are limited. Thus the agricultural sector is faced with losing an ever increasing amount of water to domestic and industrial uses; however, much of this water will return to the agricultural sector as treated waste water. There are several opportunities for improving the efficiency of water use in the Jordan Valley including: rehabilitation of the irrigation water delivery system; improvement of the operation and maintenance of the system; upgrading the skills of JVA operations and maintenance personnel; development of water delivery schedules that are compatible with cropping patterns and on-farm irrigation systems, particularly micro-irrigation systems; providing water of adequate quality for use with micro-irrigation delivery systems; training and providing information and technical assistance to farmers; and assisting in the development of water user organizations. This paper discusses the activities that are currently underway and are proposed to conserve water in the Jordan Valley

Optical and electrochemical studies of passive film formation in amorphous Ni‐Cr‐P‐C alloys

The investigation of passivation of an amorphous Ni‐l4Cr‐17P‐0.5C alloy in lN H2 SO4 through anodic polarization and near‐normal optical reflectance is reported. It was found that the alloy passivates with a current density of 10− 1 A/m2 extending to 1.0 V with current density dependent upon surface morphology. In the transpassive region under constant current density conditions the reflectance of the film exhibits strong interference phenomena and overall exponential decay in intensity. The behavior of the system in this region is described with a single thin‐film optical model consistent with the formation of a chromium phosphate deposit layer which increases in thickness at a rate of 7 nm/s at a 1.67 mV/s sweep rate

Delayed phase of Hematoporphyrin-Induced Phototoxicity: Modulation by Complement, Leukocytes, and Antihistamines

We have investigated the role of complement, leukocytes, and histamine in the delayed phase of hematoporphyrin-induced phototoxicity in guinea pigs. The phototoxic response was quantified by the accumulation of intravenously injected [125I]bovine serum albumin in the skin. There was a greater than 6-fold increase in the vascular response at the completion of irradiation, which subsided partially to reach a plateau of twice the preirradiation level between 0.5 h and 12 h. At 18 h the vascular responsiveness returned to the baseline value. The 7 h timepoint was selected in this study to evaluate the modulation of the delayed phase. In complement-depleted guinea pigs, as well as in leukopenic animals, the enhancement in the vascular response was significantly suppressed (p vs control, < 0.0001 and 0.0022. respectively). Cimetidine, when administered prior to irradiation, significantly suppressed the phototoxic response (p vs control, 0.0365). The combination of diphenhydramine and cimetidine, administered 6 h after the induction of phototoxicity, also suppressed the vascular response (p vs control, < 0.0001). These data indicate that the expression of the delayed phase of hematoporphyrin-iuduced phototoxicity, similar to the early phase, requires the presence of an intact complement system, leukocytes, and histamine

Hybrid Method for Digits Recognition using Fixed-Frame Scores and Derived Pitch

This paper presents a procedure of frame normalization based on the traditional dynamic time warping (DTW) using the LPC coefficients. The redefined method is called as the DTW frame-fixing method (DTW-FF), it works by normalizing the word frames of the input against the reference frames. The enthusiasm to this study is due to neural network limitation that entails a fix number of input nodes for when processing multiple inputs in parallel. Due to this problem, this research is initiated to reduce the amount of computation and complexity in a neural network by reducing the number of inputs into the network. In this study, dynamic warping process is used, in which local distance scores of the warping path are fixed and collected so that their scores are of equal number of frames. Also studied in this paper is the consideration of pitch as a contributing feature to the speech recognition. Results showed a good performance and improvement when using pitch along with DTW-FF feature. The convergence rate between using the steepest gradient descent is also compared to another method namely conjugate gradient method. Convergence rate is also improved when conjugate gradient method is introduced in the back-propagation algorithm

Numerical modeling of thermal refraction in liquids in the transient regime

We present the results of modeling of nanosecond pulse propagation in optically absorbing liquid media. Acoustic and electromagnetic wave equations must be solved simultaneously to model refractive index changes due to thermal expansion and/or electrostriction, which are highly transient phenomena on a nanosecond time scale. Although we consider situations with cylindrical symmetry and where the paraxial approximation is valid, this is still a computation-intensive problem, as beam propagation through optically thick media must be modeled. We compare the full solution of the acoustic wave equation with the approximation of instantaneous expansion (steady-state solution) and hence determine the regimes of validity of this approximation. We also find that the refractive index change obtained from the photo-acoustic equation overshoots its steady-state value once the ratio between the pulsewidth and the acoustic transit time exceeds a factor of unity

All-Optical Modulation Via Nonlinear Cascading In Type-Ii 2Nd-Harmonic Generation

Utilizing a type II interaction for second-harmonic generation in a crystal of potassium titanyl phosphate, we experimentally demonstrate the all-optical action of a light modulator with both signal and output at the same optical wavelength. This modulator is controlled by the intensity of the injected signal, a characteristic that makes it a suitable candidate for all-optical transistor action and ultrafast analog processing in transparent networks for telecommunications

Life and Death at the Edge of a Windy Cliff

The survival probability of a particle diffusing in the two dimensional domain $x>0$ near a ``windy cliff'' at $x=0$ is investigated. The particle dies upon reaching the edge of the cliff. In addition to diffusion, the particle is influenced by a steady ``wind shear'' with velocity $\vec v(x,y)=v\,{\rm sign}(y)\,\hat x$, \ie, no average bias either toward or away from the cliff. For this semi-infinite system, the particle survival probability decays with time as $t^{-1/4}$, compared to $t^{-1/2}$ in the absence of wind. Scaling descriptions are developed to elucidate this behavior, as well as the survival probability within a semi-infinite strip of finite width $|y|<w$ with particle absorption at $x=0$. The behavior in the strip geometry can be described in terms of Taylor diffusion, an approach which accounts for the crossover to the $t^{-1/4}$ decay when the width of the strip diverges. Supporting numerical simulations of our analytical results are presented.Comment: 13 pages, plain TeX, 5 figures available upon request to SR (submitted to J. Stat. Phys.