Arcesio Londoño Palacio, un caldense con proyección nacional

Arcesio Londoño Palacio, gracias a la formación de jurista recibida en el Colegio Mayor de Nuestra Señora del Rosario y como digno representante de Caldas, desarrolló un papel preponderante en el Senado de la Republica, en el Directorio Liberal Caldense y en el Directorio Nacional Liberal, y en su calidad de presidente de la Federación Nacional de Comerciantes FENALCO, Logró un mayor sentido de pertenencia. Su vida y obra constituyen una oportunidad para encontrar no solo paginas de nuestra historia, con todos los detalles de política y las diversas concepciones del estado, sino interesantes capítulos de la historia universitaria, departamental y empresarial de la primera mitad del siglo XX.

氟碳铈矿萃取分离过程中的热力学和动力学研究

本论文遵循基础一应用一基础的研究思路，围绕“攀西稀土矿饰、牡、稀土萃取分离流程”开展了工作。为该流程的工业试验提供了重要参数，并系统研究了萃取过程的热力学和动力学机理，发现了一种完全不同于传统协萃效应的被萃物质之间的协同效应，并利用萃取第三相制备了纳米粉。1、首次将伯胺萃针工艺应用于攀西矿，为工业试验提供了重要参数并在工业试验中得到验证；优化了Cyanex 923萃饰流程的工艺参数，去除了反萃段分离牡工艺，使流程大大简化。2、首次模拟攀西氟碳饰矿料液系统研究了复杂体系中Cyanex923萃取饰和氟的热力学，推导了萃取过程中的化学反应，为萃取分离和回收氟提供了理论依据，硼酸使氟的萃取率明显上升，即硼酸对萃取氟存在热力学协同效应。3,得出了Cyanex 923萃取饰以及饰和氟的动力学方程，推导了界面反应机理，首次发现了单一萃取剂体系中被萃物质之间存在动力学协萃效应，即氟使萃取饰的速率明显加快。硼酸对萃取饰的动力学没有影响。4、揭示了Cya1eX923萃取硫酸或硫酸饰溶液过程中出现第三相的机理和三相的相行为，发现萃取剂浓度越高，形成第三相的临界水相酸度越高，饰的引入也使临界水相酸度升高。首次利用萃取第三相制备了纳米级氧化饰粉末。

The Modelling of Photovoltaic, Solar Thermal, and Photovoltaic/Thermal Domestic Hot Water Systems

Solar heating of potable water has traditionally been accomplished through the use of solar thermal (ST) collectors. With the recent increases in availability and lower cost of photovoltaic (PV) panels, the potential of coupling PV solar arrays to electrically heated domestic hot water (DHW) tanks has been considered. Additionally, innovations in the SDHW industry have led to the creation of photovoltaic/thermal (PV/T) collectors, which heat water using both electrical and thermal energy. The current work compared the performance and cost-effectiveness of a traditional solar thermal (ST) DHW system to PV-solar-electric DHW systems and a PV/T DHW system. To accomplish this, a detailed TRNSYS model of the solar hot water systems was created and annual simulations were performed for 250 L/day and 325 L/day loads in Toronto, Vancouver, Montreal, Halifax, and Calgary. It was shown that when considering thermal performance, PV-DHW systems were not competitive when compared to ST-DHW and PVT-DHW systems. As an example, for Toronto the simulated annual solar fractions of PV-DHW systems were approximately 30%, while the ST-DHW and PVT-DHW systems achieved 65% and 71% respectively. With current manufacturing and system costs, the PV-DHW system was the most cost-effective system for domestic purposes. The capital cost of the PV-DHW systems were approximately $1,923-$2,178 depending on the system configuration, and the ST-DHW and PVT system were estimated to have a capital cost of $2,288 and $2,373 respectively. Although the capital cost of the PVT-DHW system was higher than the other systems, a Present Worth analysis for a 20-year period showed that for a 250 L/day load in Toronto the Present Worth of the PV/T system was approximately $4,597, with PV-DHW systems costing approximately $7,683-$7,816 and the ST-DHW system costing $5,238.

Synergistic extraction and recovery of Cerium(IV) and Fluorin from sulfuric solutions with Cyanex 923 and di-2-ethylhexyl phosphoric acid

Synergistic extraction and recovery of Cerium(IV) (Ce(IV)) and Fluorin (F) from sulfuric solutions using mixture of Cyanex 923 and di-2-ethylhexyl phosphoric acid (D2EHPA) in n-heptane have been carried out. in order to investigate the synergistic extraction of Cyanex 923 + D2EHPA, extraction Ce(IV), F, Ce(III) and Ce-F mixture solution using D2EHPA or Cyanex 923 as extractant alone were studied firstly, and then Synergistic extraction of Ce(IV), F and Ce(IV)-F mixture solution with D2EHPA + Cyanex 923 were carried out. The largest synergistic coefficient of Ce(IV) is obtained at the mole fraction X-Cyanex (923) = 0.8. The synergistic enhancement coefficients (R-max) obtained for Ce(IV) are 23.12 in Ce(IV) solution, and in Ce-F mixed solution R-max for Ce(IV) and F are 2.24 and 3.25 respectively.

Operator and organizational maintenance manual : armament subsystem, helicopter, 7.62 millimeter machine gun-2.75 inch rocket launcher, M21 (1090-923-5971) (used on UH-1B and UH-1C helicopters).

Includes index.

Organizational maintenance repair parts and special tools list : armament subsystem, helicopter, 7.62 millimeter machine gun-2.75 inch rocket launcher, M21 (1090-923-5971) (used on UH-1B and UH-1C helicopters).

Includes index.

Direct support, general support, and depot maintenance repair parts and special tools list : armament subsystem, helicopter, 7.62 millimeter machine gun-2.75 inch rocket launcher, M21 (1090-923-5971) (used on UH-1B and UH-1C helicopters).

"October 1970."

SEM, EDS and vibrational spectroscopic study of dawsonite NaAl(CO3)(OH)2

In this work we have studied the mineral dawsonite by using a combination of scanning electron microscopy with EDS and vibrational spectroscopy. Single crystals show an acicular habitus forming aggregates with a rosette shape. The chemical analysis shows a phase composed of C, Al, and Na. Two distinct Raman bands at 1091 and 1068 cm−1 are assigned to the CO32− ν1 symmetric stretching mode. Multiple bands are observed in both the Raman and infrared spectra in the antisymmetric stretching and bending regions showing that the symmetry of the carbonate anion is reduced and in all probability the carbonate anions are not equivalent in the dawsonite structure. Multiple OH deformation vibrations centred upon 950 cm−1 in both the Raman and infrared spectra show that the OH units in the dawsonite structure are non-equivalent. Raman bands observed at 3250, 3283 and 3295 cm−1 are assigned to OH stretching vibrations. The position of these bands indicates strong hydrogen bonding of the OH units in the dawsonite structure. The formation of the mineral dawsonite has the potential to offer a mechanism for the geosequestration of greenhouse gases.

Diphenylantimony(V) oxo/chloro carboxylates and phosphinates: crystal structures of {SbPh2Cl[O2P(C6H11)2]}2O and [SbPh2(O2CPh)2]2O

Reaction of SbPh(2)Cl(3) (1 mol) with the silver salt of dicyclohexylphosphinic acid (2 mol) afforded {SbPh(2)Cl[O2P(C6H11)(2)]}O-2 1, a similar reaction with AgO2P(C8H15)(2) gave a product formulated as {SbPh(2)Cl[O2P(C8H15)(2)]}O-2 2. Similar reactions with silver carboxylates (1:3 stoichiometry) led to the crystalline derivatives [SbPh(2)(O(2)CR)(2)]O-2 (R = Ph 3, CHPh(2) 4, 2,4,6-Me(3)C(6)H(2) 5, 2-MeC(6)H(4) 6 or 4-MeC(6)H(4) 7), whereas the 1:2 reaction afforded crystalline SbPh(2)Cl(O(2)CR)(2) (R = Ph 8, 2-MeC(6)H(4) 9 or 4-MeC(6)H(4) 10). Interconversion of the previously known compounds [SbPh(2)(O(2)CMe)(2)]O and Sb(4)Ph(8)O(6) . 3MeCO(2)H was achieved and established by H-1 NMR spectroscopy. Compounds 1 and 3 were further characterized by X-ray diffraction; the antimony in 1 is six-co-ordinated with bridging phosphinates whereas in 3 it is seven-co-ordinated with chelating benzoates. Short Sb-O (oxo) distances (1.923 Angstrom) and near linearity at the bridging ox

Thermoelectric properties of Fe(0.2)Co(3.8)Sbi(12-x)Te(x) skutterudites

Skutterudites Fe(0.)2Co(3.8)Sb(12),Te-x (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6) were synthesized by induction melting at 1273 K, followed by annealing at 923 K for 144 h. X-ray powder diffraction and electron microprobe analysis confirmed the presence of the skutterudite phase as the main phase. The temperature-dependent transport properties were measured for all the samples from 300 to 818 K. A positive Seebeck coefficient (holes are majority carriers) was obtained in Fe0.2Co3.8Sb 12 in the whole temperature range. Thermally excited carriers changed from n-type to p-type in Fe(0.)2Co(3.8)Sb(12),Te-x 19Te0.1 at 570 K, while in all the other samples, Fe(0.)2Co(3.8)Sb(12),Te-x (x = 0.2, 0.3, 0.4, 0.5, 0.6) exhibited negative Seebeck coefficients in the entire temperature range measured. Whereas for the alloys up to x = 0.2 (Fe(0.)2Co(3.8)Sb(12),Te-x ) the electrical resistivity decreased by charge compensation, it increased for x> 0.2 with an increase in Te content as a result of an increase in the electron concentration. The thermal conductivity decreased with Te substitution owing to carrier phonon scattering and point defect scattering. The maximum dimensionless thermoelectric figure of merit, ZT = 1.04 at 818 K, was obtained with an optimized Te content for Fe0.2Co3.8Sb1 1.5Te0.5 and a carrier concentration of,,J1/ =- 3.0 x 1020 CM-3 at room temperature. Thermal expansion (a = 8.8 x 10-6 K-1), as measured for Fe(0.)2Co(3.8)Sb(12),Te-x , compared well with that of undoped Co4Sb12. A further increase in the thermoelectric figure of merit up to ZT = 1.3 at 820 K was achieved for Fe(0.)2Co(3.8)Sb(12),Te-x , applying severe plastic deformation in terms of a high-pressure torsion process. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Soluble Angiopoietin Receptor Tie-2 In Patients With Acute Myocardial Infarction And Its Detection By Optical Protein-Chip

The Tie-2 receptor has been shown to play a role in angiogenesis in atherosclerosis. The conventional method assaying the level of soluble Tie-2 (sTie-2) was ELISA. However, this method has some disadvantages. The aims of this research are to establish a more simple detection method, the optical protein-chip based on imaging ellipsomtry (OPC-IE) applying to Tie-2 assay. The sTie-2 biosensor surface on silicon wafer was prepared first, and then serum levels of sTie-2 in 38 patients with AMI were measured on admission (day 1), day 2, day 3 and day 7 after onset of chest pain and 41 healthy controls by ELISA and OPC-IE in parallel. Median level of sTie-2 increased significantly in the AMI patients when compared with the controls. Statistics showed there was a significant correlation in sTie-2 results between the two methods (r=0.923, P0.01). The result of this study showed that the level of sTie-2 increased in AMI, and OPC-IE assay was a fast, reliable, and convenient technique to measure sTie-2 in serum.

Liquid-liquid extraction of cerium(IV) from nitric acid media by di-(2-ethylhexyl) 2-ethylhexyl phosphonate (DEHEHP)

In this paper, the extraction of Ce(IV) from nitric acid solutions is investigated using di-(2-ethylhexyl) 2-ethylhexyl phosphonate (DEHEHP, B) in heptane as extractant. Ce(IV) can be extracted effectively from nitric acid solution, whereas it is poorly extracted from sulfuric acid solution. Compared with some other organophosphorus esters, DEHEHP has moderate extractablity for Ce(IV). The extraction efficiency varies with diluent in the order: aliphatic hydrocarbons > nitrobenzene > aromatic hydrocarbons > carbon tetrachloride > chloroform. Regeneration and loading capacities of DEHEHP have also been examined. Ce(IV) extraction in HNO3 solutions as well as extraction of HNO3 and H2O have been systematically studied. The Ce(IV) extraction increases with an increasing of HNO3 concentration and exhibits the maximum distribution ratio at 1-1.5 mol/L HNO3. Nitric acid, as a source of nitrate ion, enhances the extraction of metal ion. But it also competes with metal ions for extractant molecules by its own extraction under high acidities. The proposed extraction process is described by the following equilibrium equations

Determination of Hg(II) in waters by on-line preconcentration using Cyanex 923 as a sorbent - Cold vapor atomic absorption spectrometry

Using a solid phase extraction mini-column home-made from a neutral extractant Cyanex 923, inorganic Hg could be on-line preconcentrated and simultaneously separated from methyl mercury. The preconcentrated Hg (11) was then eluted with 10% HNO3 and subsequently reduced by NaBH4 to form Hg vapor before determination by cold vapor atomic absorption spectrometry (CVAAS). Optimal conditions for and interferences on the Hg preconcentration and measurement were at 1% HCl, for a 25 mL sample uptake volume and a 10 mL min(-1) sample loading rate. The detection limit was 0.2 ng L-1 and much lower than that of conventional method (around 15.8 ng L-1). The relative standard deviation (RSD) is 1.8% for measurements of 40 ng L-1 of Hg and the linear working curve is from 20 to 2000 ng L-1 (with a correlation coefficient of 0.9996). The method was applied in determination of inorganic Hg in city lake and deep well water (from Changchun, Jilin, China), and recovery test results for both samples were satisfactory.