Some factors affecting agricultural production .and productivity in Iraq including selected climate variables and crops

In this study of factors affecting Iraqi agricultural production and productivity, it has been found essential to deal both with socioeconomic and technical factors on the one hand and environmental conditons on the other. The ultimate objective of this study is to assess the impact of selected climatic factors on the production and productivity of some principal crops. Such assessment, however, cannot be achieved in isolation from the influence of the socio-economic and technical factors. Considerable variability over time of the latter factors, caused by specific institutional changes such as the land reform of 1958, resulted in changes in agricultural conditions as a whole. Therefore, in Chapters Two to Nine are examined the national and regional conditions of Iraqi agriculture during the 1950-1975 period, i.e. planning and investment, land utilization, land tenure system and land reform, agricultural cooperatives and other organizations, new input factors including farm machinery and, finally, water resources and irrigation methods. The inescapable conclusion of this section of the study is that there were no significant medium or long-term improvement trends in the yields of principal crops despite varying but considerable additional inputs and planning attention. Moreover, the controls exerted by climate and weather appear crucial factors in both the irrigated and rainfed area. In Chapters Ten and Eleven we therefore turn to a direct examination of climatic and weather factors. In Chapters Twelve and Thirteen a study is made of the relationship between selected weather variables, i.e. rainfall, temperature and relative humidity, and wheat and barley yield. These two crops were chosen because of their importance to Iraqi agriculture as a whole, and in particular to the rainfed area of northern Iraq where environmental modifications by man are least strong. The first point appearing from this analysis shows that yields of these two crops are significantly affected by climatic and weather factors during specific periods within the growing season. The significance of statistical correlations between yields and certain critical climatic factors appear sufficiently valid for crop forecasting with a certain degree of accuracy. As a by-product of this analysis, it appears that there was a significant dislocation period following the implementation of land reform measures. In conclusion, it is clear that agricultural production and productivity must be dealt with in the context of a whole set of factors, socio-economic, technical and environmental, if significant developments in agriculture and rural welfare are to be achieved

Randomised feasibility study of a novel experience-based internet intervention to support self-management in chronic asthma.

ElectronicPeer reviewedPublisher PD

Three Dimensional Mapping of Texture in Dental Enamel

We have used synchrotron x-ray diffraction to study the crystal orientation in human dental enamel as a function of position within intact tooth sections. Keeping tooth sections intact has allowed us to construct 2D and 3D spatial distribution maps of the magnitude and orientation of texture in dental enamel. We have found that the enamel crystallites are most highly aligned at the expected occlusal points for a maxillary first premolar, and that the texture direction varies spatially in a three dimensional curling arrangement. Our results provide a model for texture in enamel which can aid researchers in developing dental composite materials for fillings and crowns with optimal characteristics for longevity, and will guide clinicians to the best method for drilling into enamel, in order to minimize weakening of remaining tooth structure, during dental restoration procedure

Correlation between TcT_c and anisotropic scattering in Tl2_2Ba2_2CuO6+δ_{6+\delta}

Angle-dependent magnetoresistance measurements are used to determine the isotropic and anisotropic components of the transport scattering rate in overdoped Tl$_2$Ba$_2$CuO$_{6+\delta}$ for a range of $T_c$ values between 15K and 35K. The size of the anisotropic scattering term is found to scale linearly with $T_c$, establishing a link between the superconducting and normal state physics. Comparison with results from angle resolved photoemission spectroscopy indicates that the transport and quasiparticle lifetimes are distinct.Comment: 5 pages, 3 figures, accepted for publication in Physical Review Letter

Transient macroscopic chemistry in the DSMC method

In the Direct Simulation Monte Carlo method, a combination of statistical and deterministic procedures applied to a finite number of `simulator' particles are used to model rarefied gas-kinetic processes. Traditionally, chemical reactions are modelled using information from specific colliding particle pairs. In the Macroscopic Chemistry Method (MCM), the reactions are decoupled from the specific particle pairs selected for collisions. Information from all of the particles within a cell is used to determine a reaction rate coefficient for that cell. MCM has previously been applied to steady flow DSMC simulations. Here we show how MCM can be used to model chemical kinetics in DSMC simulations of unsteady flow. Results are compared with a collision-based chemistry procedure for two binary reactions in a 1-D unsteady shock-expansion tube simulation and during the unsteady development of 2-D flow through a cavity. For the shock tube simulation, close agreement is demonstrated between the two methods for instantaneous, ensemble-averaged profiles of temperature and species mole fractions. For the cavity flow, a high degree of thermal non-equilibrium is present and non-equilibrium reaction rate correction factors are employed in MCM. Very close agreement is demonstrated for ensemble averaged mole fraction contours predicted by the particle and macroscopic methods at three different flow-times. A comparison of the accumulated number of net reactions per cell shows that both methods compute identical numbers of reaction events. For the 2-D flow, MCM required similar CPU and memory resources to the particle chemistry method. The Macroscopic Chemistry Method is applicable to any general DSMC code using any viscosity or non-reacting collision models and any non-reacting energy exchange models. MCM can be used to implement any reaction rate formulations, whether these be from experimental or theoretical studies. ©2009 American Institute of Physic

Evaluation of gas explosion overpressures at configurations with irregularly arranged obstacles

Rapid analytical methods for the calculation of gas explosion overpressures in confined and congested regions are of great value where a benchmark value is sought rather than a time consuming detailed analysis obtainable by computational fluid dynamics (CFD). While earlier correlations have been compared directly to experiments, the geometries used were often simplistic and displayed homogeneity in confinement and congestion. Realistic geometries typically display a high degree of inhomogeneity in confinement and congestion. Here the authors examine geometries where the confinement and congestion were deliberately varied such that some of the geometries possessed inhomogeneity of both parameters. Little experimental data exists for such configurations and hence the authors examine these configurations using CFD. The CFD overpressure predictions at various target locations for 400 scenarios are compared with the results from a newly derived correlation and the correlation of the guidance for the application of the multi-energy method (GAME). It is found that the overpressure predictions obtained using the correlation still better agrees with the CFD modeling results compared with the GAME correlation suggesting. To show the importance of increased accuracy in these cases, a structural damage level evaluation process is used to place the damage levels for four monitor points on a p-i curve, and the results show that often these damage levels are near critical, demonstrating the need for improved accuracy

Adsorption of iron ions from palm oil mill effluent using novel adsorbent of alginate–mangrove composite beads coated by chitosan

This study was about the investigation of the removal of iron ions from Palm Oil Mill Effluent (POME) by using novel adsorbent which is Alginate–Mangrove Composite Beads Coated by Chitosan (AMCBCC). The adsorbent was characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM) with Energy Dispersive X-ray Spectroscopy (EDX) to prove the successful coating by Chitosan and also to provide an evidence of iron ions were adsorbed on the surface of the beads. Batch studies were conducted by using different parameters, such as pH, dosage, contact time, and initial concentration. It was found that at pH value of 3, 300 g/L of AMCBCC concentration, and a contact time of 72 hours the maximum removal of iron ions was 92.7%. The isotherm equilibrium data were followed Freundlich isotherm model and the adsorption kinetic data were well fitted by the pseudo second order

First record of Atractoscion aequiden (Sciaenidae) from the Arabian Sea Coasts of Oman and Acanthopagrus catenula (Sparidae) from the Oman Sea (Gulf of Oman), northwestern Indian Ocean (Teleostei, Sciaenidae, Sparidae)

Primer registro de Atractoscion aequidens (Sciaenidae) en las costas del mar de Arabia de Omán y de Acanthopagrus catenula (Sparidae) en el mar de Omán (golfo de Omán), al noroeste del océano Índico (Teleostei, Sciaenidae, Sparidae) Los primeros registros de Atractoscion aequidens en las costas del mar de Arabia de Omán y de Acanthopagrus catenula en las aguas próximas a la ciudad de Muscat, en el mar de Omán, se efectúan a partir de un espécimen de 671 mm de longitud estándar y diez especímenes de 111 a 257 mm de longitud estándar, respectivamente. Este informe da cuenta del segundo registro de A. aequidens en el norte del océano Índico y del registro más septentrional de A. catenula efectuado en dicho océano. Se especifican los datos morfométricos y merísticos de ambas especies y se comparan con los de los especímenes recolectados en otras partes del mundo. En este trabajo se corrige asimismo la distribución meridionThe first record of Atractoscion aequidens from the Arabian Sea coasts of Oman and Acanthopagrus catenula from waters around City of Muscat on the Sea of Oman is reported based on one (671 mm in SL) and ten specimens (111-257 mm SL), respectively. This account represents the second record of A. aequidens in the northern Indian Ocean and the northernmost record of A. catenula in the same ocean. Morphometric and meristic data are provided for the two species and compared with those from specimens collected from other parts of the world. The southern distribution of A. catenula is corrected in this report.Primer registro de Atractoscion aequidens (Sciaenidae) en las costas del mar de Arabia de Omán y de Acanthopagrus catenula (Sparidae) en el mar de Omán (golfo de Omán), al noroeste del océano Índico (Teleostei, Sciaenidae, Sparidae) Los primeros registros de Atractoscion aequidens en las costas del mar de Arabia de Omán y de Acanthopagrus catenula en las aguas próximas a la ciudad de Muscat, en el mar de Omán, se efectúan a partir de un espécimen de 671 mm de longitud estándar y diez especímenes de 111 a 257 mm de longitud estándar, respectivamente. Este informe da cuenta del segundo registro de A. aequidens en el norte del océano Índico y del registro más septentrional de A. catenula efectuado en dicho océano. Se especifican los datos morfométricos y merísticos de ambas especies y se comparan con los de los especímenes recolectados en otras partes del mundo. En este trabajo se corrige asimismo la distribución meridio

Fractal Antennas for Wireless Communications

When the length of the antenna is less than a quarter of the wavelength of the operating frequency, good radiation properties are difficult to obtain. However, size limitations can be overcome in this case using a fractal geometry antenna. The shape is repeated in a limited size such that the total length of the antenna is increased to match, for example, half of the wavelength of the corresponding desired frequency. Many fractal geometries, e.g., the tree, Koch, Minkowski, and Hilbert fractals, are available. This chapter describes the details of designing, simulations, and experimental measurements of fractal antennas. Based on dimensional geometry in terms of desired frequency bands, the characteristics of each iteration are studied carefully to improve the process of designing the antennas. In depth, the surface current distribution is investigated and analyzed to enhance the circular polarization radiation and axial ratio bandwidth (ARBW). Both, simulation and experimental, results are discussed and compared. Two types of fractal antennas are proposed. The first proposed fractal antenna has a new structure configured via a five-stage process. The second proposed fractal antenna has a low profile, wherein the configuration of the antenna was based on three iterations

Angle dependent magnetoresistance measurements in Tl2_2Ba2_2CuO6+δ_{6+\delta} and the need for anisotropic scattering

The angle-dependent interlayer magnetoresistance of overdoped Tl$_2$Ba$_2$CuO$_{6+\delta}$ has been measured in high magnetic fields up to 45 Tesla. A conventional Boltzmann transport analysis with no basal-plane anisotropy in the cyclotron frequency $\omega_c$ or transport lifetime $\tau$ is shown to be inadequate for explaining the data. We describe in detail how the analysis can be modified to incorporate in-plane anisotropy in these two key quantities and extract the degree of anisotropy for each by assuming a simple four-fold symmetry. While anisotropy in $\omega_c$ and other Fermi surface parameters may improve the fit, we demonstrate that the most important anisotropy is that in the transport lifetime, thus confirming its role in the physics of overdoped superconducting cuprates.Comment: 14 pages, 13 Figure