Assessment of impact of climatic change on groundwater quality around Igbokoda Coastal area, southwestern Nigeria

Hydrochemical assessment of 39 groundwater samples within Igbokoda coastal zone are presented and discussed in terms of impact of coastal saltwater on the quality and subsequent hydrochemical evolution. The pH range from 6.8 to 9.8, temperature from 28.3 to 33.5oC, EC from 67 to 2440µS/cm and TH from 66.36 to 369.22mg/L. Hydrochemical results showed higher concentrations of Na+ (3.56 – 624.14mg/L) compared to Ca2+ (19.21 – 104.32mg/L), K+ (1.49 – 62.94mg/L) compared to Mg2+ (3.36 – 75.01mg/L) and Cl- (72.0 – 2592.00mg/L) compared to HCO3- (15.25 – 152.50mg/L). This hydrochemical profile reflects a Na-Cl dominated water type suggesting impact of salt water on the groundwater system. Nonetheless, with the exception of higher Cl- values, the major ions concentrations are within recommended WHO standard for drinking water while the concentrations of Fe (0.01-13.4mg/L) and Mn (0.00-1.00mg/L) above the WHO guideline values in about 88% and 35% of the samples respectively call for concern. Estimated major ionic ratios such as Mg/Ca (0.13 – 3.09), Cl/HCO3 (1.18 – 25.50) signify brackish water in most of the locations due to impact of saltwater mixing. This is clearly reflected in the water characterization that revealed largely Na-(K)-Cl-SO4 water type as brackish water and minor occurrence of Ca-(Mg)-HCO3 water type as freshwater sources

Meta-stable SUSY Breaking Model in Supergravity

We analyze a supersymmetry (SUSY) breaking model proposed by Intriligator, Seiberg and Shih in a supergravity (SUGRA) framework. This is a simple and natural setup which demands neither extra superpotential interactions nor an additional gauge symmetry. In the SUGRA setup, the U(1)R symmetry is explicitly broken by the constant term in the superpotential, and pseudo-moduli field naturally takes non-zero vacuum expectation value through a vanishing cosmological constant condition. Sfermions tend to be heavier than gauginos, and the strong-coupling scale is determined once a ratio of sfermion to gaugino masses is fixed.Comment: 13 page

Orion\u27s Veil. IV. H\u3csub\u3e2\u3c/sub\u3e Excitation and Geometry

The foreground Veil of material that lies in front of the Orion Nebula is the best studied sample of the interstellar medium because we know where it is located, how it is illuminated, and the balance of thermal and magnetic energy. In this work, we present high-resolution STIS observations toward the Trapezium, with the goal of better understanding the chemistry and geometry of the two primary Veil layers, along with ionized gas along the line of sight. The most complete characterization of the rotational/vibrational column densities of H2 in the almost purely atomic components of the Veil are presented, including updates to the Cloudy model for H2 formation on grain surfaces. The observed H2 is found to correlate almost exclusively with Component B. The observed H2, observations of CI, CI*, and CI**, and theoretical calculations using Cloudy allow us to place the tightest constraints yet on the distance, density, temperature, and other physical characteristics for each cloud component. We find the H2 excitation spectrum observed in the Veil is incompatible with a recent study that argued that the Veil was quite close to the Trapezium. The nature of a layer of ionized gas lying between the Veil and the Trapezium is characterized through the emission and absorption lines it produces, which we find to be the blueshifted component observed in S iii and P iii absorption. We deduce that, within the next 30–60 thousand years, the blueshifted ionized layer and Component B will merge, which will subsequently merge with Component A in the next one million years

Physical Conditions in Orion\u27s Veil. II. A Multicomponent Study of the Line of Sight toward the Trapezium

Orion\u27s Veil is an absorbing screen that lies along the line of sight to the Orion H II region. It consists of two or more layers of gas that must lie within a few parsecs of the Trapezium cluster. Our previous work considered the Veil as a whole and found that the magnetic field dominates the energetics of the gas in at least one component. Here we use high-resolution STIS UV spectra that resolve the two velocity components in absorption and determine the conditions in each. We derive a volume hydrogen density, 21 cm spin temperature, turbulent velocity, and kinetic temperature for each. We combine these estimates with magnetic field measurements to find that magnetic energy significantly dominates turbulent and thermal energies in one component, while the other component is close to equipartition between turbulent and magnetic energies. We observe H2 absorption for highly excited v, J levels that are photoexcited by the stellar continuum, and detect blueshifted S+2 and P+2 ions. These ions must arise from ionized gas between the mostly neutral portions of the Veil and the Trapezium and shields the Veil from ionizing radiation. We find that this layer of ionized gas is also responsible for He I λ3889 absorption toward the Veil, which resolves a 40 year old debate on the origin of He I absorption toward the Trapezium. Finally, we determine that the ionized and mostly atomic layers of the Veil will collide in less than 85,000 yr

Functional characterization of generalized Langevin equations

We present an exact functional formalism to deal with linear Langevin equations with arbitrary memory kernels and driven by any noise structure characterized through its characteristic functional. No others hypothesis are assumed over the noise, neither the fluctuation dissipation theorem. We found that the characteristic functional of the linear process can be expressed in terms of noise's functional and the Green function of the deterministic (memory-like) dissipative dynamics. This object allow us to get a procedure to calculate all the Kolmogorov hierarchy of the non-Markov process. As examples we have characterized through the 1-time probability a noise-induced interplay between the dissipative dynamics and the structure of different noises. Conditions that lead to non-Gaussian statistics and distributions with long tails are analyzed. The introduction of arbitrary fluctuations in fractional Langevin equations have also been pointed out

Impact of Cover Crops and Phosphorus Fertilizer Management on Nutrient Cycling in No-Tillage Corn-Soybean Rotation

The objective of this study was to quantify the effects of cover crops and different fertilizer management techniques on the amount of nutrients being removed and recycled in the soil system. This study was conducted at Ashland Bottoms, KS, from 2014-2016. A 2 × 3 factorial design with three replicates was utilized in this study. The fertilizer management treatments included a control of 0 lb/a P2O5, along with fall broadcast and spring injected applications of P2O5 based on a build and maintain recommendation system. Results show that total uptake of K2O and recycling of P2O5 and K2O are directly influenced by cover cropping. Application of P2O5 fertilizer also statistically impacted the yield of soybeans during the 2016 growing season

Physical Conditions in Orion\u27s Veil

Orion\u27s veil consists of several layers of largely neutral gas lying between us and the main ionizing stars of the Orion Nebula. It is visible in 21 cm H I absorption and in optical and UV absorption lines of H I and other species. Toward θ1 Ori C, the veil has two remarkable properties, a high magnetic field (~100 μG) and a surprising lack of H2, given its total column density. Here we compute photoionization models of the veil to establish its gas density and its distance from θ1 Ori C. We use a greatly improved model of the H2 molecule that determines level populations in 105 rotational/vibrational levels and provides improved estimates of H2 destruction via the Lyman-Werner bands. Our best-fit photoionization models place the veil 1-3 pc in front of the star at a density of 103-104 cm-3. Magnetic energy dominates the energy of nonthermal motions in at least one of the 21 cm H I velocity components. Therefore, the veil is the first interstellar environment in which magnetic dominance appears to exist. We find that the low ratio of H2/H0 (\u3c10-4) is a consequence of high UV flux incident on the veil due to its proximity to the Trapezium stars and the absence of small grains in the region

Thermal Evolution of the Non Supersymmetric Metastable Vacua in N=2 SU(2) SYM Softly Broken to N=1

It has been shown that four dimensional N=2 gauge theories, softly broken to N=1 by a superpotential term, can accommodate metastable non-supersymmetric vacua in their moduli space. We study the SU(2) theory at high temperatures in order to determine whether a cooling universe settles in the metastable vacuum at zero temperature. We show that the corrections to the free energy because of the BPS dyons are such that may destroy the existence of the metastable vacuum at high temperatures. Nevertheless we demonstrate the universe can settle in the metastable vacuum, provided that the following two conditions are hold: first the superpotential term is not arbitrarily small in comparison to the strong coupling scale of the gauge theory, and second the metastable vacuum lies in the strongly coupled region of the moduli space.Comment: 32 pages, 30 figure

Yukawa couplings and masses of non-chiral states for the Standard Model on D6-branes on T6/Z6'

The perturbative leading order open string three-point couplings for the Standard Model with hidden USp(6) on fractional D6-branes on T6/Z6' from arXiv:0806.3039 [hep-th], arXiv:0910.0843 [hep-th] are computed. Physical Yukawa couplings consisting of holomorphic Wilsonian superpotential terms times a non-holomorphic prefactor involving the corresponding classical open string Kaehler metrics are given, and mass terms for all non-chiral matter states are derived. The lepton Yukawa interactions are at leading order flavour diagonal, while the quark sector displays a more intricate pattern of mixings. While N=2 supersymmetric sectors acquire masses via only two D6-brane displacements - which also provide the hierarchies between up- and down-type Yukawas within one quark or lepton generation -, the remaining vector-like states receive masses via perturbative three-point couplings to some Standard Model singlet fields with vevs along flat directions. Couplings to the hidden sector and messengers for supersymmetry breaking are briefly discussed.Comment: 52 pages (including 8p. appendix); 5 figures; 14 tables; v2: discussion in section 4.1.3 extended, footnote 5 added, typos corrected, accepted by JHE

Lectures on Supersymmetry Breaking

We review the subject of spontaneous supersymmetry breaking. First we consider supersymmetry breaking in a semiclassical theory. We illustrate it with several examples, demonstrating different phenomena, including metastable supersymmetry breaking. Then we give a brief review of the dynamics of supersymmetric gauge theories. Finally, we use this dynamics to present various mechanisms for dynamical supersymmetry breaking. These notes are based on lectures given by the authors in 2007, at various schools.Comment: 47 pages. v2: minor correction