1,516 research outputs found
Effects of organic fertilisers and compost extracts on organic tomato production
The effects of various fertilizers and different compost extracts on crop health and tomato yield were studied in the field in 2004â2005 in two locations in Iran. Treatments included different fertilizers (cattle, sheep and chicken manures, green waste and household composts and chemical fertilizers) and five aqueous extracts (from cattle manure, chicken manure, green-waste and house-hold composts and water as control). The effect of fertilizer type on tomato yield was significant in both locations (P < 0.05). Organic fertilizer use did not obtain higher yields compared to using chemical fertiliser. Generally, chicken manure and green-waste compost led to the highest and lowest tomato yield among different organic fertilizers, respectively. The effect of aqueous extracts was not significant on either crop health or tomato yield with these results were being very limited and inconsistent. Improved efficacy of acceptable alternatives to agrochemicals, especially in organic farming, is required
Equity Returns and Business Cycles in Small Open Economies
This is the first paper in the literature to match key business cycle moments and long-run equity returns in a small open economy with production. These results are achieved by introducing three modications to a standard real business cycle model: (1) borrowing and lending costs are imposed to increase the volatility of the intertemporal marginal rate of substitution; (2) investment adjustment costs are assumed to make equity returns more volatile; and (3) GHH preferences are employed to smooth consumption. We also decompose the contributions of productivity, the world interest rate, and government expenditure shocks to the equity premium. Our results are based on data from Argentina, Brazil, and Chile.Asset Pricing; Equity Returns; Dynamic Stochastic General Equilibrium Model; Real Business Cycle; Small Open Economy.
Reaction Chemistry of Silver(I) Trifluoromethanesulfonate Complexes of Nitrogen-Confused \u3cem\u3eC\u3c/em\u3e-Scorpionates
Two new C-scorpionate ligands with a bis(3,5-dimethylpyrazol-1-yl)methyl group bound to the 3 position of either an N-tosyl (TsL*) or an NâH pyrazole (HL*) ring have been prepared. The silver(I) complexes of these new ligands and the two previously reported analogous ligands with unsubstituted bis(pyrazol-1-yl)methyl groups (TsL and HL) in both 1:1 and 2:1 ligand/metal ratios were investigated to explore the effects of ligand sterics on their physical and chemical properties. The structurally characterized derivatives of the type [Ag(L)2](OTf) are four-coordinate, where the confused pyrazolyl is not bound to the metal. On the other hand, three 1:1 complexes [Ag(L)](OTf) had all pyrazolyls bound, while the ÎŒâÎș1,Îș1-TsL derivative had an unbound confused pyrazolyl. The molecularity of the latter four ranged from polymeric to dimeric to monomeric in the solid with increasing steric bulk of the ligand. The utility of these complexes in stoichiometric ligand-transfer reactions and in styrene aziridination was demonstrated. Thus, tricarbonylmanganese(I) complexes were prepared as kinetically inert models for comparative solution diffusion NMR studies. Also, [Fe(HL)2](OTf)2 was prepared for similar reasons and to compare the effects of anion on spin-crossover properties
Flux Expulsion - Field Evolution in Neutron Stars
Models for the evolution of magnetic fields of neutron stars are constructed,
assuming the field is embedded in the proton superconducting core of the star.
The rate of expulsion of the magnetic flux out of the core, or equivalently the
velocity of outward motion of flux-carrying proton-vortices is determined from
a solution of the Magnus equation of motion for these vortices. A force due to
the pinning interaction between the proton-vortices and the neutron-superfluid
vortices is also taken into account in addition to the other more conventional
forces acting on the proton-vortices. Alternative models for the field
evolution are considered based on the different possibilities discussed for the
effective values of the various forces. The coupled spin and magnetic evolution
of single pulsars as well as those processed in low-mass binary systems are
computed, for each of the models. The predicted lifetimes of active pulsars,
field strengths of the very old neutron stars, and distribution of the magnetic
fields versus orbital periods in low-mass binary pulsars are used to test the
adopted field decay models. Contrary to the earlier claims, the buoyancy is
argued to be the dominant driving cause of the flux expulsion, for the single
as well as the binary neutron stars. However, the pinning is also found to play
a crucial role which is necessary to account for the observed low field binary
and millisecond pulsars.Comment: 23 pages, + 7 figures, accepted for publication in Ap
AntiPlag: Plagiarism Detection on Electronic Submissions of Text Based Assignments
Plagiarism is one of the growing issues in academia and is always a concern
in Universities and other academic institutions. The situation is becoming even
worse with the availability of ample resources on the web. This paper focuses
on creating an effective and fast tool for plagiarism detection for text based
electronic assignments. Our plagiarism detection tool named AntiPlag is
developed using the tri-gram sequence matching technique. Three sets of text
based assignments were tested by AntiPlag and the results were compared against
an existing commercial plagiarism detection tool. AntiPlag showed better
results in terms of false positives compared to the commercial tool due to the
pre-processing steps performed in AntiPlag. In addition, to improve the
detection latency, AntiPlag applies a data clustering technique making it four
times faster than the commercial tool considered. AntiPlag could be used to
isolate plagiarized text based assignments from non-plagiarised assignments
easily. Therefore, we present AntiPlag, a fast and effective tool for
plagiarism detection on text based electronic assignments
Carrier Recombination and Generation Rates for Intravalley and Intervalley Phonon Scattering in Graphene
Electron-hole generation and recombination rates for intravalley and
intervalley phonon scattering in Graphene are presented. The transverse and the
longitudinal optical phonon modes (-modes) near the zone center
(-point) contribute to intravalley interband carrier scattering. At the
zone edge (-point), only the transverse optical phonon mode
(-mode) contributes significantly to intervalley interband scattering
with recombination rates faster than those due to zone center phonons. The
calculated recombination times range from less than a picosecond to more than
hundreds of picoseconds and are strong functions of temperature and electron
and hole densities. The theoretical calculations agree well with experimental
measurements of the recombination rates of photoexcited carriers in graphene.Comment: 6 pages, 9 figure
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Chemical Characterization and Source Apportionment of PM2.5 in Rabigh, Saudi Arabia
Schwinger Effect in Non-parallel D1-branes: A Path Integral Approach
We study the Schwinger effect in a system of non-parallel D1-branes for the
bosonic strings using the path integral formalism. We drive the string pair
creation rate by calculating the one loop vacuum amplitude of the setup in
presence of the background electric filed defined along one of the D1-branes.
We find an angle dependent minimum value for the background field and show that
the decaying of vacuum into string pairs takes place for the field above this
value. It is shown that in limit the vacuum
becomes stable and thus no pair creation occurs
Air quality in Mecca and surrounding holy places in Saudi Arabia during Hajj: initial survey.
The Arabian Peninsula experiences severe air pollution, the extent and sources of which are poorly documented. Each year in Saudi Arabia this situation is intensified during Hajj, the Holy Pilgrimage of Islam that draws millions of pilgrims to Mecca. An initial study of air quality in Mecca and surrounding holy sites during the 2012 Hajj (October 24-27) revealed strongly elevated levels of the combustion tracer carbon monoxide (CO, up to 57 ppmv) and volatile organic compounds (VOCs) along the pilgrimage route-especially in the tunnels of Mecca-that are a concern for human health. The most abundant VOC was the gasoline evaporation tracer i-pentane, which exceeded 1200 ppbv in the tunnels. Even though VOC concentrations were generally lower during a follow-up non-Hajj sampling period (April 2013), many were still comparable to other large cities suffering from poor air quality. Major VOC sources during the 2012 Hajj study included vehicular exhaust, gasoline evaporation, liquefied petroleum gas, and air conditioners. Of the measured compounds, reactive alkenes and CO showed the strongest potential to form ground-level ozone. Because the number of pilgrims is expected to increase in the future, we present emission reduction strategies to target both combustive and evaporative fossil fuel sources
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