2,322 research outputs found
Integration-free interval doubling for Riccati equation solutions
Various algorithms are given for the case of constant coefficients. The algorithms are based on two ideas: first, relate the Re solution with general initial conditions to anchored RE solutions; and second, when the coefficients are constant the anchored solutions have a basic shift-invariance property. These ideas are used to construct an integration free superlinearly convergent iterative solution to the algebraic RE. The algorithm, arranged in square-root form, is thought to be numerically stable and competitive with other methods of solving the algebraic RE
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A social cost benefit analysis of grid-scale electrical energy storage projects: a case study
This study explores and quantifies the social costs and benefits of grid-scale electrical energy storage (EES) projects in Great Britain. The case study for this paper is the Smarter Network Storage project, a 6 MW/10MWh lithium battery placed at the Leighton Buzzard Primary substation to meet growing local peak demand requirements. This study analyses both the locational and system-wide benefits to grid-scale EES, determines the realistic combination of those social benefits, and juxtaposes them against the social costs across the useful lifecycle of the battery to determine the techno-economic performance. Risk and uncertainty from the benefit streams, cost elements, battery lifespan, and discount rate are incorporated into a Monte Carlo simulation. Using this framework, society can be guided to cost-effectively invest in EES as a grid modernization asset to facilitate the transition to a reliable, affordable, and clean power system
The thermal ignition problem in a cube
Steady state solutions for spontaneous thermal ignition in a unit cube are considered. For the unit sphere there are numerous solutions possible: these appear as ``wiggles'' in the bifurcation diagram. For the unit sphere this has been shown analytically. In contrast, for the unit cube analytic solutions are not possible and hence we must resort to numerical methods to determine the corresponding bifurcation diagram. Comparisons between the cube and the sphere are made
Land Use Planning in Integrated Watershed Development Program for Improving Livelihoods
Globally, rain-fed agriculture plays an important
role to achieve food security (Rockstrom et al. 2007)
as 80% of the world’s agricultural land area is rainfed
and generates 58% of the world’s staple foods
(SIWI 2001). Most food for poor communities in the
developing countries is produced in rain-fed areas
for e.g. in sub-Saharan Africa (SSA) more than 95%
of the farmed land is rain-fed, whereas the corresponding
figure for Latin America is nearly 90%,
for South Asia about 60%, for East Asia 65% and
for Near East and North Africa 75%. In India, 60%
of 142 million ha (Mha) arable land is rain-fed. The
rain-fed areas are the hot spots of poverty, malnutrition,
water scarcity, severe land degradation;
and the investments in the rainfed agriculture pose
serious challenges as large numbers of households
are small land holders (Wani et al. 2009). These areas
are also prone to more adverse impacts of climate
change due to lack of technologies and necessary
resource to cope with the challenges of global
warming
Fast semi-automatic segmentation of focal liver lesions in contrast-enhanced ultrasound, based on a probabilistic model
Combustion waves in a model with chain branching reaction and their stability
In this paper the travelling wave solutions in the adiabatic model with
two-step chain branching reaction mechanism are investigated both numerically
and analytically in the limit of equal diffusivity of reactant, radicals and
heat. The properties of these solutions and their stability are investigated in
detail. The behaviour of combustion waves are demonstrated to have similarities
with the properties of nonadiabatic one-step combustion waves in that there is
a residual amount of fuel left behind the travelling waves and the solutions
can exhibit extinction. The difference between the nonadiabatic one-step and
adiabatic two-step models is found in the behaviour of the combustion waves
near the extinction condition. It is shown that the flame velocity drops down
to zero and a standing combustion wave is formed as the extinction condition is
reached. Prospects of further work are also discussed.Comment: pages 32, figures 2
Optimization of explants, media, plant growth regulators and carbohydrates on callus induction and plant regeneration in Citrus jambhiri Lush.
Callus induction was attempted from the four explants viz. root, cotyledon, epicotyl, and leaf segments excised from in vitro raised seedlings of C. jambhiri. Among various MS media supplementations with growth regulators and carbohydrates, the maximum (95.50%) and the earliest (8.30 days) callogenesis was obtained in epicotyl segments, when cultured on MS medium supplemented with NAA (10.0 mgl-1) + BAP (1.0 mgl-1) + sucrose (8%). The modified MS (macro and micro-nutrients reduced to half) fortified with BAP (5.0 mgl-1) + GA3 (3.0 mgl-1) recorded maximum shoot regeneration (43.10%) from callus, with an average of 5.30 shoots per callus after 35.50 days of culturing. However, prolonged exposure to GA3 resulted in thin elongated shoots and leaves. The age of the callus substantially influenced the plant regeneration frequency. The potency of the callus to regenerate decreased significantly with an increase in the age of the callus. Shoot regeneration was recorded maximum (43.43%) in 60 days old calli, followed by 90 days old (30.48%) calli, whereas it was minimum (10.46%) in 150 days old calli. The maximum (79.50%) shoot proliferation was recorded in MS medium supplemented with BAP (1.0 mgl-1) + Kin (0.5 mgl-1) with an average of 5.06 shoots per culture. The MS medium fortified with NAA (1.0 mgl-1) + IBA (1.0 mgl-1) induced maximum (77.33%) rooting, with an average of 3.19 roots per shoot after 13.4 days of culturing. Rooted plants were hardened and survived the best (83.6%) on the potting mixture consisting of cocopeat + vermiculite + perlite (2:1:1)
Gas phase production of NHD2 in L134N
We show analytically that large abundances of NH2D and NHD2 can be produced
by gas phase chemistry in the interiors of cold dense clouds. The calculated
fractionation ratios are in good agreement with the values that have been
previously determined in L134N and suggest that triply-deuterated ammonia could
be detectable in dark clouds. Grain surface reactions may lead to similar NH2D
and NHD2 enhancements but, we argue, are unlikely to contribute to the
deuteration observed in L134N.Comment: 6 pages, 2 figures, uses psfig.sty and emulateapj.sty, to appear in
Astrophysical Journal, vol 55
The impact of language and ethnicity on preparation for endoscopy: A prospective audit of an East London hospital ward
Rationale, aims and objectives:
The efficacy, cost-effectiveness and safety of a number of endoscopic procedures is largely dependent on optimal preparation. Despite this however, inadequate or suboptimal preparation is relatively common. Most studies have revealed inadequate preparation for between 20-30% of patients. This audit sought to examine the impact of English language proficiency, and ethnicity, on endoscopic preparation and procedure success or failure
Method:
A prospective audit was developed. Using convenience sampling, participants were consecutive patients recruited over a six-month period, who were aged 18 and over, attending an east London endoscopy ward for a routine (pre-booked) endoscopy procedure for which they had received preparation instructions to carry out at home.
Results:
Almost one third of the sample had adequate or very poor English proficiency. When an interpreter was used it was overwhelmingly a member of the patients’ family or a member of staff. There was no significant relationship between gender, age, ethnic group, English language proficiency, whether an interpreter was needed, the type of procedure carried out and inadequate preparation
Conclusions:
Amongst these patients we found that a little more than 20% of participants were inadequately prepared for their endoscopic procedure. We found no relationship between language proficiency on preparation. Given the mixed literature on interventions to improve preparation before endoscopic procedures, further directions are identified to work toward the development and testing of a novel intervention amongst this population. In identifying those who may be at risk for inadequate preparation for endoscopic procedures, practice needs to take into account a range of factors beyond language and ethnicity. Furthermore, the persistent reliance on family members to interpret information sheets and preparation advice suggests that revision and / or development of culture and language-specific materials is necessary
A new index to assess soil quality and sustainability of wheat-based cropping systems
Sustainability index was calculated to assess soil quality under the influence of different fertilizer management practices. It is based on the area of the triangle in which nutrient index, microbial index and crop index of soil represented the three vertices of a triangle. Nutrient index reflected the nutrient status of soil and was calculated from the measurements of various soil chemical parameters. Microbial index was calculated by determining various soil microbial and biochemical activities and crop index by measuring of crop yield parameters. Eighteen soil indicators were determined to assess nutrient index, microbial index and crop index in order to compare the effect of different sources of nutrients such as green manure, farmyard manure and chemical fertilizer in a rice/corn-wheat rotation. The indices were applied to assess the sustainability of five field experiments with respect to the different fertilizer treatments. The long-term application of organic manures in rice/corn-wheat cropping system increased the index value because it increased the nutrient index, microbial index and crop index of soils. The use of only chemical fertilizers in the rice-wheat cropping system resulted in poor soil microbial index and crop index. In corn-wheat system, additional application of FYM at 10 t ha-1 before sowing corn made the system more sustainable than application of 100% NPK; the sustainability index values were 2.43 (the highest for this system) and 0.93, respectivel
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