432 research outputs found
The Relevance of Information Communication Technologies (ICTs) In Agroforestry Practices
This paper x-rays the relevance of ICTs in Agroforestry practices. Existing areas of applications such as forest andenvironmental management, specie identification and research publications are identified. The paper also looked into futurepossible usage of ICT and concludes that while the application of ICTs to Agroforestry practices in the 21st century is oftremendous importance it is important to know that there are still more areas where ICT would be applicable in Agroforestrywhich are yet to be discoveredKeywords – ICTs, Agroforestry, Applications, Fuzzy Logic, Environmental management
THE RELEVANCE OF INFORMATION COMMUNICATION TECHNOLOGIES (ICTs) IN AGROFORESTRY PRACTICES
Heathcote (2000) posited that “Within half a century, computers and information technology have changed the world andaffected millions of lives in ways that no one could have foreseen”. The great impacts, contributions to knowledge,importance and economic achievements that have emerged from the fields of computer science (information science) andelectronic engineering, in the 21st century, are revolutionary and mind boggling (Bamgbade,2011). This paper explores theextent to which ICT applications have improved agro-forestry practices and discussed areas of application such as forestryand environmental management, species identification, research publication, ICT in agroforestry education, plant pathologystudies, wood anatomy, biometrics, Data management, modeling, analysis and miningKeywords: ICTs, Agroforestry, Impact, Management, Computers, Practices and Applications
Resonant Three-Photon Ionization of Atomic Hydrogen in a Finite-Bandwidth Laser Field and a Static Electric Field
We derive a set of density matrix equations describing laser photo-excitation and ionization of
atomic hydrogen in the presence of an external electric field. The equations are relevant as a description of multiphoton
ionization of hydrogen (or deuterium) atoms in laser-produced transient plasmas. The laser wavelength
is 243 nm, so that the photoionization is resonant with the 2 s 1/2 level. The electric field causes Stark mixing of
the 2 s 1/2 level with the 2 p 1/2 and 2 p 3/2
levels. Because the electric field is taken in the same direction as the linear
polarization of the laser, only states with equal
m j are coupled, and the atom can be described with a four-level
density matrix. The laser bandwidth is taken into account by using the stochastic model of a chaotic laser field
introduced by Zoller [1]. We present a few calculations of the probabilities for ionization and excitation of a
single hydrogen atom as a function of laser intensity and wavelength
Black hole solutions in massive gravity
The static vacuum spherically symmetric solutions in massive gravity are
obtained both analytically and numerically. The solutions depend on two
parameters (integration constants): the mass M (or, equivalently, the
Schwarzschild radius), and an additional parameter, the "scalar charge" S. At
zero value of S and positive mass the standard Schwarzschild black hole
solutions are recovered. Depending on the parameters of the model and the signs
of M and S, the solutions may or may not have horizon. Those with the horizon
describe modified black holes provided they are stable against small
perturbations. In the analytically solvable example, the modified black hole
solutions may have both attractive and repulsive (anti-gravitating) behavior at
large distances. At intermediate distances the gravitational potential of a
modified black hole may mimics the presence of dark matter. Modified black hole
solutions are also found numerically in more realistic massive gravity models
which are attractors of the cosmological evolution.Comment: Original version + erratu
Classical, novel and atypical isoforms of PKC stimulate ANF- and TRE/AP-1-regulated-promoter activity in ventricular cardiomyocytes
Cultured neonatal rat ventricular myocytes were co-transfected with expression plasmids encoding protein kinase C (PKC) isoforms from each of the PKC subfamilies (classical PKC-α, novel PKC-ε or atypical PKC-ξ) together with an atrial natriuretic factor (ANF) reporter plasmid. Each PKC had been rendered constitutively active by a single Ala→Glu mutation or a small deletion in the inhibitory pseudosubstrate site. cPKC-α, nPKC-ε or aPKC-ξ expression plasmids each stimulated ANF-promoter activity and expression of a reporter gene under the control of a 12-O-tetradecanoylphorbol 13-acetate-response element (TRE). Upregulation of the ANF promoter is characteristic of the hypertrophic response in the heart ventricle and a TRE is present in the ANF promoter. Thus all subfamilies of PKC may have the potential to contribute to hypertrophic response in cardiomyocytes
Wavelength dependent collective effects in the multiphoton ionization of atomic deuterium
This paper presents the results of an experimental investigation into collective effects in the transient plasma
formed by multiphoton ionization of atomic deuterium with a pulsed laser. The laser wavelength is varied in a
narrow range around 243 nm, so that the photoionization is resonant with the metastable 2S1/2 state. The ion
yield, the ion time-of-flight spectra, and the yield of Lyman-a photons have been measured as a function of
laser intensity ~from 1 to 340 MW/cm2! and laser detuning around the 1S1/2-2S1/2 two-photon resonance.
During and shortly after the laser pulse, collective effects resulting from the mutual interaction of the photoelectrons
and the ions affect the spatial and temporal distribution of the ions. Because of the near-degeneracy
of the 2S1/2, 2P1/2 , and 2P3/2 states, the resonant multiphoton ionization is affected by the Stark mixing of
these states in the collective field. As a result, the time-dependent yields of ions and of Lyman-a photons are
modulated by the interplay of the multiphoton ionization of the atoms and the collective effects in the plasma.
From the measurements it is deduced that collective effects are important above a critical charge density of
33108 ions/cm3. An asymmetry is observed in the line profile of the total ion yield as a function of laser
detuning. This asymmetry is interpreted to be due to the effect of the collective field upon the intermediate
resonant 2S1/2 state of the photoionization process
Wavelength dependent collective effects in the multiphoton ionization of atomic deuterium
This paper presents the results of an experimental investigation into collective effects in the transient plasma
formed by multiphoton ionization of atomic deuterium with a pulsed laser. The laser wavelength is varied in a
narrow range around 243 nm, so that the photoionization is resonant with the metastable 2S1/2 state. The ion
yield, the ion time-of-flight spectra, and the yield of Lyman-a photons have been measured as a function of
laser intensity ~from 1 to 340 MW/cm2! and laser detuning around the 1S1/2-2S1/2 two-photon resonance.
During and shortly after the laser pulse, collective effects resulting from the mutual interaction of the photoelectrons
and the ions affect the spatial and temporal distribution of the ions. Because of the near-degeneracy
of the 2S1/2, 2P1/2 , and 2P3/2 states, the resonant multiphoton ionization is affected by the Stark mixing of
these states in the collective field. As a result, the time-dependent yields of ions and of Lyman-a photons are
modulated by the interplay of the multiphoton ionization of the atoms and the collective effects in the plasma.
From the measurements it is deduced that collective effects are important above a critical charge density of
33108 ions/cm3. An asymmetry is observed in the line profile of the total ion yield as a function of laser
detuning. This asymmetry is interpreted to be due to the effect of the collective field upon the intermediate
resonant 2S1/2 state of the photoionization process
Comparison of the serious injury pattern of adult bicyclists, between South-West Netherlands and the State of Victoria, Australia 2001-2009
Background: Head injury is the leading cause of death and long term disability from bicycle injuries and may be prevented by helmet wearing. We compared the pattern of injury in major trauma victims resulting from bicyclist injury admitted to hospitals in the State of Victoria, Australia and South-West Netherlands, with respective high and low prevalence of helmet use among bicyclists. Methods: A cohort of bicycle injured patients with serious injury (defined as Injury Severity Score > 15) in South-West Netherlands, was compared to a cohort of serious injured bicyclists in the State of Victoria, Australia. Additionally, the cohorts of patients with serious injury admitted to a Dutch level 1 trauma centre in Rotterdam, the Netherlands and an Australian level 1 trauma centre in Melbourne, Australia were compared. Both cohorts included patients admitted between July 2001 and June 2009. Primary outcome was in-hospital mortality and secondary outcome was prevalence of severe injury per body region. Outcome was compared using univariate analysis and mortality outcomes were also calculated using multivariable logistic regression models. Results: A total of 219 cases in South-West Netherlands and 500 cases in Victoria were analyzed. Further analyses comparing the major trauma centres in each region, showed the percentage of bicycle-related death was higher in the Dutch population than in the Australian (n = 45 (24%) vs n = 13(7%); P < 0.001). After adjusting for age, mechanism of injury, GCS and head injury severity in both hospitals, there was no significant difference in mortality (adjusted odds ratio 1.4; 95% confidence interval = 0.6, 3.5). Patients in Netherlands trauma centre suffered from more serious head injuries (Abbreviated Injury Scale ≥ 3) than patients in the Australian trauma centre (n = 165 (88.2%) vs n = 121 (62.4%); P < 0.001). The other body regions demonstrated significant differences i
Humeral shaft fractures: Retrospective results of non-operative and operative treatment of 186 patients
Background: Humeral shaft fractures account for 1-3% of all fractures and 20% of the fractures involving the humerus. The aim of the current study was to compare the outcome after operative and non-operative treatment of humeral shaft fractures, by comparing the time to radiological union and the rates of delayed union and complications. Methods: All patients aged 16 years or over treated for a humeral shaft fracture during a 5-year period were included in this retrospective analysis; periprosthetic and pathological fractures were excluded. Radiographs and medical charts were retrieved and reviewed in order to collect data on fracture classification, time to radiographic consolidation and the occurrence of adverse events. Results: A total of 186 patients were included; 91 were treated non-operatively and 95 were treated operatively. Mean age was 58.7 ± 1.5 years and 57.0% were female. In 83.3% of the patients, only the humerus was affected. A fall from standing height was the most common cause of the fracture (72.0%). Consolidation time varied from a median of 11-28 weeks. The rate of radial nerve palsy in both groups was similar: 8.8% versus 9.5%. In 5.3% of the operatively treated patients, the palsy resulted from the operation. Likewise, delayed union rates were similar in both groups: 18.7% following non-operative trea
Електрофізичні властивості системи політетрафторетилен – вуглецеві нанотрубки
Проведено дослідження комплексної діелектричної проникності та електропровідності в надвисокочастотному діапазоні (9 ГГц) і на низьких частотах (0,1; 1 та 10 кГц) двох систем політетрафторетилен – багатошарові вуглецеві нанотрубки з вихідними та диспергованими у водному середовищі . Введення диспергованих нанотрубок в полімер знижує поріг перколяції з 4,5 % до 2,6 % (мас.) за рахунок рівномірного розподілу наповнювача у полімері, що призводить до зростання міжфазної поверхні взаємодії полімер – вуглецеві нанотрубки, яка проявляється в збільшенні значень дійсної та уявної складової комплексної діелектричної проникності.Проведены исследования комплексной диэлектрической проницаемости и электропроводности в сверхвысокочастотном диапазоне (9 ГГц) и на низких частотах (0,1; 1; 10 кГц) двух систем политетрафторэтилен–многослойные углеродные нанотрубки с исходными и диспергированными у водной среде. Введение диспергированных нанотрубок в полимер снижает порог перколяции с 4,5% до 2,6 % (масс.) за счет равномерного распределения наполнителя в полимере, что приводит к возрастанию межфазной поверхности взаимодействия полимер – углеродные нанотрубки, которая проявляется в увеличении значений действительной и мнимой составляющей комплексной диэлектрической проницаемости.Complex dielectric permeability and conductivity of two systems, namely polytetrafluorethylene – intact carbon nanotubes and polytetrafluorethylene – carbon nanotubes dispersed in aqueous media, has been studied in super high-frequency range (9 GHz) and at low frequencies (0,1; 1 and 10 kHz). Doping of the polymer with the dispersed nanotubes decreases percolation threshold (limit ) from 4,5 wt. % to 2,6 wt. % due to uniform distribution of the filler in the polymer. This results to increase of interface interaction polymer - carbon nanotubes that is demonstrated by increase of value of real and imaginary component of complex dielectric permeability
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