Importancia de las competencias laborales como generadores de productividad en las empresas colombianas.Importance of labor skills as generators of productivity in Colombian companies.

A comprehensive kinetic model for methanation of syngas on Ni-Mo-SiO2catalyst was developed on a fixed bed reactor data. The CO and H2conversion, methane selectivity and yield were obtained in a wide range of operating conditions including 300 < T < 450°C, 1 < H2/CO <4 and 0.1 < P < 1.5 MPa with the total weight hourly space velocity (WHSV) of 60000 ml/h/g. A 6-step reaction scheme defined to the description of a reaction network that considers both catalytic and gas-phase as well as primary and consecutive reaction steps to predict the performance of the syngas methantion. Orthogonal design method was adopted to select test points with temperature, pressure and feed compositions as factors and the kinetic rates involved Langmuir – Hinshelwood equation kinetic model. The kinetic rate parameters were estimated using the Least Square Method by MATLAB. Comparing the experimental and model predicted data showed that presented model has a reasonable fit between the experimental data and the predicted values with average absolute relative deviation of ±9.8%.

Background This study aims to determine the influence of vitrectomy combined with macular epiretinal membrane dissection and internal limiting membrane (ILM) peeling and phacoemulsification on choroidal vasculature in patients with unilateral idiopathic epiretinal membrane (IERM) and concurrent cataract using optical coherence tomography (OCT). Methods This retrospective study included 26 eyes of 26 patients (8 males and 18 females) with unilateral IERM without vitreomacular traction (VMT) (group 1) and the patients’ fellow eyes (n = 26, group 2). Three-port 25-G pars plana vitrectomy (PPV) combined with macular epiretinal membrane dissection and ILM peeling and phacoemulsification was performed on all patients. The comprehensive ophthalmologic examinations of all patients involved OCT measurements at every visit before and after surgery, and the choroidal thickness (CT), central macular thickness (CMT) and choroidal vascularity index (CVI) were calculated. Results The mean age of the IERM patients was 66.58 ± 7.06 years. Postoperatively, best corrected visual acuity (BCVA) was significantly greater than baseline (P = 0.023). The CVI of the IERM eyes was significantly lower (P < 0.01) than that of the fellow eyes at baseline. The subfoveal CT in the IERM eyes was lower than that in the fellow eyes (P = 0.023), but there was, no significant difference in the average CT between the two groups at baseline (P = 0.071). In eyes with IERM, the CVI significantly increased at 1 week, 1 month (P < 0.001), and 3 months (P = 0.049) postoperatively, the subfoveal CT was markedly thickened 1 month after surgery (P = 0.001), the temporal 3 mm and nasal CT significantly increased at 1 week and 1 month postoperatively (P = 0.041, P = 0.022 for temporal 3 mm; P < 0.001, P = 0.047 for nasal 1.5 mm; P = 0.01, P = 0.001 for nasal 3 mm), and only the temporal 3 mm CT increased significantly at 3 months postoperatively (P = 0.017). The baseline CMT of the IERM eyes was significantly thicker than that of the fellow eyes (P < 0.001). CMT significantly decreased at 3 months postoperatively in IERM eyes(P = 0.033). Conclusions The increase in the CVI in the IERM eyes without VMT after combined PPV with ILM peeling and phacoemulsification persists for at least 3 months.