6,976 research outputs found
CREATING AGRIBUSINESS OPPORTUNITIES FOR SMALL SCALE FARMERS IN THABA NCHU BY INTRODUCING WATER HARVESTING TECHNIQUES: A PROFITABILITY AND RISK ANALYSIS
Thaba Nchu is a semi-arid area with low and erratic annual rainfall not exceeding 600mm. Various dryland crops are produced with relatively low yields and high risk of failure. Lack of appropriate technology and other constraints has led to most of the arable land being unused thus restricting agribusiness opportunities in an area where unemployment and food insecurity are thriving. Rainwater harvesting has a huge potential to increase crop yields in Thaba Nchu and reduce the risk of losses, and thus improve food security and enhance sustainability. Different in-field rainwater harvesting (IRWH) techniques have been tested and applied at Glen and Thaba Nchu. This paper gives comparative results for three crops produced with regard to relative profitability and risk of failure. This is done by integrating crop enterprise budgets with crop yield simulations models to calculate per hectare profits over an 81-year period and developing and analyzing cumulative probability functions.Land Economics/Use, Resource /Energy Economics and Policy, Risk and Uncertainty,
Dynamics and Decay of Heavy-Light Hadrons
Recent signals for narrow hadrons containing heavy and light flavours are
compared with quark model predictions for spectroscopy, strong decays, and
radiative transitions. In particular, the production and identification of
excited charmed and cs states are examined with emphasis on elucidating the
nature of and states. Roughly 200 strong decay amplitudes of
and states up to 3.3 GeV are presented. Applications include determining
flavour content in mesons and the mixing angle in and wave
states and probes of putative molecular states. We advocate searching for
radially excited states in B decays.Comment: 19 pages, 7 figures, revtex. A numerical error is corrected. Some
strong decay rates have change
The red rain phenomenon of Kerala and its possible extraterrestrial origin
A red rain phenomenon occurred in Kerala, India starting from 25th July 2001,
in which the rainwater appeared coloured in various localized places that are
spread over a few hundred kilometers in Kerala. Maximum cases were reported
during the first 10 days and isolated cases were found to occur for about 2
months. The striking red colouration of the rainwater was found to be due to
the suspension of microscopic red particles having the appearance of biological
cells. These particles have no similarity with usual desert dust. An estimated
minimum quantity of 50,000 kg of red particles has fallen from the sky through
red rain. An analysis of this strange phenomenon further shows that the
conventional atmospheric transport processes like dust storms etc. cannot
explain this phenomenon. The electron microscopic study of the red particles
shows fine cell structure indicating their biological cell like nature. EDAX
analysis shows that the major elements present in these cell like particles are
carbon and oxygen. Strangely, a test for DNA using Ethidium Bromide dye
fluorescence technique indicates absence of DNA in these cells. In the context
of a suspected link between a meteor airburst event and the red rain, the
possibility for the extraterrestrial origin of these particles from cometary
fragments is discussed.Comment: 18 pages, 15 figures, accepted for publication in Astrophysics and
Space Scienc
Strong Decays of Excited Heavy Mesons In Chiral Perturbation Theory
We construct an effective Lagrangian describing the interaction of soft pions
and kaons with mesons containing a heavy quark and light degrees of freedom in
an orbital wave. The formalism is easily extended to heavy mesons and
baryons in arbitrary excited states. We calculate the leading contributions to
the strong decays \dtwo\to\d\pi, \dtwo\to\dstar\pi and \done\to\dstar\pi.
We confirm the relations between the rates previously obtained by Isgur and
Wise using heavy quark symmetry, and find that the absolute widths are
consistent with na\"\i ve power counting. We also estimate the branching ratios
for the two pion decays \dtwo\to\dstar\pi\pi, \done\to\dstar\pi\pi and
\done\to\d\pi\pi, which are dominated by pole graphs. Our predictions depend
on the masses and widths of the as yet unseen scalar-pseudovector -wave
doublet. Heavy quark spin symmetry predicts \Gamma(\dtwo\to\dstar\pi\pi):
\Gamma(\done\to\dstar\pi\pi):\Gamma(\done\to\d\pi\pi)=3:1:2, but this relation
is badly violated in practice because effects arising purely from
kinematics are large.Comment: (14 pages, 2 figures available from the authors, harvmac.tex
required), SLAC-PUB-5812, UCSD/PTH 92-1
Enhancing food and livelihood security in the context of the food and financial crisis: challenges and opportunities for small scale rainwater harvesting and conservation
The world recently experienced the food and financial crisis. The food crisis was an indicator of the challenges towards sufficiently feeding an increasing world population. Food production through rainfed and irrigated agriculture account for the bulk of the freshwater used globally but the water is still sufficient to meet the MDG goal on hunger reduction. Agricultural water management is thus an important challenge for feeding humanity; creates the need to find sustainable methods of managing water that will include all water users. Some of these methods include rainwater harvesting which has great potential in increasing food production as compared to irrigation. This paper aims to identify challenges and opportunities for small scale rainwater harvesting in enhancing food and livelihoods security. Given the large array of practices that are classified as rainwater harvesting, infield rainwater harvesting (IRWH) developed and mainly practised in the Free State Province, South Africa is used. The technique has been in use in villages around Thaba Nchu for a couple of years. Previous studies have shown that the technique increased yield significantly, reduced risk and thus improved household food security. The paper traces the evolution of the technique based of previous studies and recent data, to identify the potential and challenges faced by adopting households. It is concluded that IRWH has great potential to improve household food security as well as contribute to sustainable rural livelihoods mainly as it can reduce dependence on market sourced food supplies.food security, livelihoods, rainwater harvesting, household, yield, Food Security and Poverty, Resource /Energy Economics and Policy,
Essays on the Economics of Student Achievement
Parents, lawmakers, and economists are all keenly interested in what affects student performance. This dissertation explores factors influencing student achievement in West Virginia with special attention devoted to public education resources and gender. Politicians and many parents of school age children believe increased levels of education funding or resources result in higher student achievement. Chapters 2 and 3 delve into this topic by exploring student achievement at different grade levels in West Virginia. The first public education funding or resource change to be analyzed occurred during a time period when the base for public education financing was expanding and funding levels were converging across school districts in the state. Data is a school-district level panel, including student achievement scores, from 1989 to 2002. The results suggest that rising expenditure levels may have had a positive effect on student achievement especially in areas with below average levels of spending prior to the policy change. The second
Options for the SELEX state D_{s\J}^+(2632)
We consider possible assignments for the D_{s\J}^+(2632), which was
recently reported in D and DK final states by the SELEX
Collaboration at Fermilab. The most plausible quark model assignment for this
state is the first radial excitation () of the
D, although the predicted mass and strong decay branching fractions
for this assignment are not in agreement with the SELEX data. The reported
dominance of D over DK appears especially problematic. An intriguing
similarity to the K is noted. --^3\D_1 configuration
mixing is also considered, and we find that this effect is unlikely to resolve
the branching fraction discrepancy. Other interpretations as a -hybrid
or a two-meson molecule are also considered, but appear unlikely. Thus, if this
state is confirmed, it will require reconsideration of the systematics of
charmed meson spectroscopy and strong decays.Comment: 6 revtex4 pages, 2 eps figure
P-Wave Charmed-Strange Mesons
We examine charmed-strange mesons within the framework of the constituent
quark model, focusing on the states with L=1. We are particularly interested in
the mixing of two spin-states that are involved in and the
recently discovered . We assume that these two mesons form a pair
of states with J=1. These spin-states are mixed by a type of the spin-orbit
interaction that violates the total-spin conservation. Without assuming
explicit forms for the interactions as functions of the interquark distance, we
relate the matrix elements of all relevant spin-dependent interactions to the
mixing angle and the observed masses of the L=1 quartet. We find that the
spin-spin interaction, among various types of the spin-dependent interactions,
plays a particularly interesting role in determining the spin structure of
and
A Sketch of Bangor
Jacob Buswell came to Bangor in 1769, and settled on the banks of the Penobscot River, near the foot of what is now Newbury Street. Others from Massachusetts and elsewhere soon followed him.
The settlement was originally called and written Condeskeag. Later, when it became large enough to be incorporated, its name was Sunbury; but in 1791 an act of incorporation was obtained, and the town was named Bangor, from an old psalm-tune popular at that time.
For thirty years succeeding the advent of the first pioneer, few people came to this locality, -- there being but 277 inhabitants in 1800; in 1830 there were but 2,868.
In 1834 Bangor was incorporated a city. At present (1882) its population is about 20,000; but being the shire-town of Penobscot County, centrally located at the head of navigation on the Penobscot River, and the headquarters of a large lumber business, it gives the impression of being much more populous. Surrounded as it is by numerous small towns and a large agricultural district, it is a trade-centre of no little importance.https://digicom.bpl.lib.me.us/books_pubs/1271/thumbnail.jp
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