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Groundwater is the main source of freshwater for drinking and irrigation in Edea. However, growing demands from agriculture, population growth and urbanization have adversely affected groundwater quality in the area. Hence, the objectives of this study were to evaluate the suitability of groundwater for drinking and irrigation uses and quantify the human health risks associated with consuming nitrate-contaminated water in the study area. Groundwater samples were collected and analyzed to evaluate water quality based on thirteen hydrochemical parameters: pH, electrical conductivity (EC), total dissolved solids (TDS), total hardness (TH), calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), bicarbonate (HCO3−), chloride (Cl−), nitrate (NO3−), sulfate (SO42−), and phosphate (PO43−). The study revealed that anion abundances followed the order of HCO3−> NO3−> Cl−> SO42−> PO43−while cation abundances were Ca2+> Mg2+> Na+> K+. According to WHO standards, the pH, HCO3−, PO43−and NO3−levels exceeded their prescribed limits. The main source of nitrate was identified as fertilizer usage in agricultural fields. The groundwater was predominantly characterized as Ca–Mg–HCO3and Ca–Mg–Cl–SO4types, which resulted primarily from water–rock interactions. Water Quality Index (WQI) analysis found that the groundwater was generally good for drinking. Regarding irrigation suitability, the groundwater in the region generally met the criteria for %Na, SAR, RSC, KI, PS and PI, making it suitable for irrigation. However, 43.48% of the samples were deemed unsuitable based on the magnesium hazard. Furthermore, the study observed that the corrosivity ratios in 39.13% of samples were high enough to potentially cause corrosion when transporting water through metal pipes. The health risk assessment revealed that children in the study area faced a higher risk compared to teenagers and adults. The study proposed management measures to protect groundwater resources in the area.

A geoelectric survey was carried out in parts of the Sanaga maritime division where the limited quality of surface water sources, insufficient geophysical knowledge and a growing population have had a significant impact on the assessment and development of groundwater in the area. Forty-six vertical electrical soundings (VES) involving the Schlumberger electrode configuration were carried out across the study area to assess the groundwater potential and vulnerability which will assist in the proper siting of wells/boreholes. The VES survey was carried out using the ABEM SAS 1000 instrument with a maximum current electrode spread (AB/2) of 120 m. Field data obtained were curve-matched and iterated using the JOINTEM software to estimate groundwater repositories. The modelling results revealed three to five geoelectric layers including the topsoil, laterite, weathered formation, cracked gneiss and gneiss. VES curves obtained included the A, AA, H, HA, HK, HKH, KH, KHK, and QH. A correlation between borehole logs and the VES lithology was made and is in agreement. The aquifer unit was identified at the third and fourth geoelectric layers with thickness and resistivity ranging from 18 to 47 m and 93-16500 m, respectively. The evaluated aquifer parameters (longitudinal conductance, transverse resistance, hydraulic conductivity, transmissivity, reflection coefficient and fracture contrast) ranged: 0.0026 to 0.28 mhos, 1981 to 702,405 , 0.05 to 5.67 m/day, 2-150 , -0.67 to 0.93, and 0.19 to 29, respectively. Contour maps were drawn from the estimated aquifer parameters to show their distribution in the study area, from which groundwater potential areas were delineated. The distribution of longitudinal conductance showed poor to moderate protective capacity throughout the study area. The findings of this study hold significant value as a reference for guiding groundwater exploration and development activities in the study area.

The force field conversion from one MD program to another one is exhausting and error-prone. Although single conversion tools from one MD program to another exist not every combination and both directions of conversion are available for the favorite MD programs Amber, Charmm, Dl-Poly, Gromacs, and Lammps. We present here a general tool for the force field conversion on the basis of an XML document. The force field is converted to and from this XML structure facilitating the implementation of new MD programs for the conversion. Furthermore, the XML structure is human readable and can be manipulated before continuing the conversion. We report, as testcases, the conversions of topologies for acetonitrile, dimethylformamide, and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate comprising also Urey-Bradley and Ryckaert-Bellemans potentials. © 2017 Wiley Periodicals, Inc., (© 2017 Wiley Periodicals, Inc.)