Assessment of wood waste generation and utilization in Makurdi metropolis: Implication for sustainable management of forest resources

This study assessed forest waste generation and utilization in Makurdi metropolis. The increasing quantities of wood wastes from timber sheds, furniture industries and chainsaw millers possess a threat to the sustainable management of forest resources and environmental sustainability. Descriptive statistics such as frequency, mean, percentages and tables, were used  to analyze the result. A five-point Likert scale was used to determine the level of utilization ofwood wastes. The findings of the study revealed three major sources of wood waste which were: timber sheds (37.8%), furniture factories (33%) and chainsaw millers (29.2%) while the types of wood wastes include: sawdust (14.9%), wood chippings (12.8%), wood shavings (21.1%), offcuts (20.2%) and trims (21%). Generated wood wastes were utilized as: animal beddings (39.4%) mulching (28%), generation of household energy (22.7%) briquettes production (6.0%) and engineered wood production (3.9%). The result on the level of utilization of wood waste indicated that it was low with Weighted Mean Score (WMS) of 1.9042. Lack of awareness (55.9%) was the most limiting factor of wood waste utilization followed by lack of technical know-how (18.6%), lack of start-up capital (25%) while the least limiting factor was inadequate raw material (0.5%). This study therefore concludes that the level of utilization of wood waste in Makurdi metropolis was very low. It is therefore, recommended that policy measures or incentives should be provided to wood merchants to encourage investments into utilization of wood wastes in Makurdi metropolis. Keywords: Wood waste, Wood generation, Wood utilization, Sustainable managemen

Totemic Beliefs and Biodiversity Conservation among the Tiv People of Benue State, Nigeria.

Biodiversity depletion has been a major problem in many communities of the world including Benue State, Nigeria. The use of indigenous beliefs by some communities has been reported to assist in the conservation of biodiversity. Therefore, this study was conducted with the aim of identifying such beliefs that have been used or are still being used as tools for biodiversity conservation by the Tiv tribe of Central Nigeria. Both in-depth interview with key informants (IDI) and Focus Group Discussions (FGDs) methods were used. In the case of IDI, traditional rulers as custodians of the peoples’ culture were purposively chosen while in FGD, elders among households were chosen. It was found that 18 totems which included animal, plants and shrines/deities exert significant influence in the conservation of biodiversity in the study area. Therefore Totemism should be used pari-pasu with other conventional methods to conserve biodiversity. Key words: Totem, biodiversity depletion, indigenous beliefs, conservation

High-quality genome sequence and description of Paenibacillus dakarensis sp. nov.

AbstractStrain FF9T was isolated in Dakar (Senegal) from a blood-culture taken from a 16-month-old child. MALDI-TOF analysis did not allow for identification. After sequencing, strain FF9T exhibited 98.18% similarity with the 16SrRNA sequence of Paenibacillus uliginis. A polyphasic study of phenotypic and genomic analyses showed that strain FF9T is Gram variable, catalase-positive, and presents a genome of 4,569,428 bp (one chromosome but no plasmid) with 4,427genes (4,352 protein-coding and 75 RNA genes (including 3 rRNA operons). The G+C content is 45.7%. On the basis of these genomic and phenotypic data analyses, we propose the creation of Paenibacillus dakarensis strain FF9T

Conflict and HIV: A framework for risk assessment to prevent HIV in conflict-affected settings in Africa

In sub-Saharan Africa, HIV/AIDS and violent conflict interact to shape population health and development in dramatic ways. HIV/AIDS can create conditions conducive to conflict. Conflict can affect the epidemiology of HIV/AIDS. Conflict is generally understood to accelerate HIV transmission, but this view is simplistic and disregards complex interrelationships between factors that can inhibit and accelerate the spread of HIV in conflict and post conflict settings, respectively. This paper provides a framework for understanding these factors and discusses their implications for policy formulation and program planning in conflict-affected settings

High-order Harmonic Generation and Dynamic Localization in a driven two-level system, a non-perturbative solution using the Floquet-Green formalism

We apply the Floquet-Green operator formalism to the case of a harmonically-driven two-level system. We derive exact expressions for the quasi-energies and the components of the Floquet eigenstates with the use of continued fractions. We study the avoided crossings structure of the quasi-energies as a function of the strength of the driving field and give an interpretation in terms of resonant multi-photon processes. From the Floquet eigenstates we obtain the time-evolution operator. Using this operator we study Dynamic Localization and High-order Harmonic Generation in the non-perturbative regime

Harmonic generation in ring-shaped molecules

We study numerically the interaction between an intense circularly polarized laser field and an electron moving in a potential which has a discrete cylindrical symmetry with respect to the laser pulse propagation direction. This setup serves as a simple model, e.g., for benzene and other aromatic compounds. From general symmetry considerations, within a Floquet approach, selection rules for the harmonic generation [O. Alon Phys. Rev. Lett. 80 3743 (1998)] have been derived recently. Instead, the results we present in this paper have been obtained solving the time-dependent Schroedinger equation ab initio for realistic pulse shapes. We find a rich structure which is not always dominated by the laser harmonics.Comment: 15 pages including 7 figure

Transmission Properties of the oscillating delta-function potential

We derive an exact expression for the transmission amplitude of a particle moving through a harmonically driven delta-function potential by using the method of continued-fractions within the framework of Floquet theory. We prove that the transmission through this potential as a function of the incident energy presents at most two real zeros, that its poles occur at energies $n\hbar\omega+\varepsilon^*$ ($0<Re(\varepsilon^*)<\hbar\omega$), and that the poles and zeros in the transmission amplitude come in pairs with the distance between the zeros and the poles (and their residue) decreasing with increasing energy of the incident particle. We also show the existence of non-resonant "bands" in the transmission amplitude as a function of the strength of the potential and the driving frequency.Comment: 21 pages, 12 figures, 1 tabl

Changes in Floquet state structure at avoided crossings: delocalization and harmonic generation

Avoided crossings are common in the quasienergy spectra of strongly driven nonlinear quantum wells. In this paper we examine the sinusoidally driven particle in a square potential well to show that avoided crossings can alter the structure of Floquet states in this system. Two types of avoided crossings are identified: on type leads only to temporary changes (as a function of driving field strength) in Floquet state structure while the second type can lead to permanent delocalization of the Floquet states. Radiation spectra from these latter states show significant increase in high harmonic generation as the system passes through the avoided crossing.Comment: 8 pages with 10 figures submitted to Physical Review

Exact exchange-correlation potential for a time-dependent two electron system

We obtain an exact solution of the time-dependent Schroedinger equation for a two-electron system confined to a plane by an isotropic parabolic potential whose curvature is periodically modulated in time. From this solution we compute the exact time-dependent exchange correlation potential v_xc which enters the Kohn-Sham equation of time-dependent density functional theory. Our exact result provides a benchmark against which various approximate forms for v_xc can be compared. Finally v_xc is separated in an adiabatic and a pure dynamical part and it is shown that, for the particular system studied, the dynamical part is negligible.Comment: 23 pages, 6 figure

Floquet Formalism of Quantum Pumps

We review Floquet formalism of quantum electron pumps. In the Floquet formalism the quantum pump is regarded as a time dependent scattering system, which allows us to go beyond the adiabatic limit. It can be shown that the well-known adiabatic formula given by Brouwer can be derived from the adiabatic limit of Floquet formalism. We compare various physical properties of the quantum pump both in the adiabatic and in the non-adiabatic regime using the Floquet theory.Comment: Latex2e 16 pages, 6 figures. A review paper to appear in Int. J. Mod. Phys.