[en] Highlights: • The enthalpies of solution of C-alkylresorcin[4]arenes in alcohols were measured. • The character exothermic or endothermic do not vary monotonically. • Transfer enthalpies were calculated and solvation enthalpies were estimated. - Abstract: Enthalpies of solution of five C-alkylresorcin[4]arenes (alkyl = ethyl, n-butyl, n-pentyl or n-hexyl) in methanol, ethanol and propanol as a function of molal concentration were measured by semiadiabatic calorimetry at T = 298.15 K. The enthalpies at infinite dilution and the enthalpies of transfer from propanol were calculated. The enthalpies of solvation were estimated and their values are negative. The (solute + solvent) interactions between C-ethylresorcin[4]arene, C-butylresorcin[4]arene, and C-pentylresorcin[4]arene and alcohols are principally determined by van der Waals interactions, whereas hydrogen bonds are the predominate factor in alcoholic solutions of C-methylresorcin[4]arene and C-hexylresorcin[4]arene.

[en] The understanding of water flow paths around a wetland is based on the hydrologic information interpretation. Although the incorporation of non-conventional techniques like hydrochemistry and isotopic hydrology allows a major compression level of hydrologic systems: They allow identify origin and evolution of water, movement times, permanence in the hydrologic cycle components. Cienaga Colombia wetland and its catch area, represent a strategic ecosystem located in the Bajo Cauca antioqueno. The natural conditions and the consequences of the human intervention on the wetland impose the need to approach its study and understanding, seeking to be able lo design effective measures to guarantee its sustainability. We presents the firsts results of the project developed by Antioquia University and IAEA: Hydrochemical and Isotopic techniques for the assessment of hydrological processes in the wetlands of Bajo Cauca Antioqueno which is part of the program: Isotopic techniques for assessment of hydrological processes in wetlands by International Atomic Energy Agency, IAEA. The general objective of the study is evaluate the dynamic of water flow, in and out of the wetland in the Bajo Cauca Antioqueno, using geochemical and isotopic techniques.

[en] The process of crude distillation impacts the economy of any refinery in a considerable manner. Therefore, it is necessary to improve it taking good advantage of the available infrastructure, generating products that conform to the specifications without violating the equipment operating constraints or plant restrictions at industrial units. The objective of this paper is to present the development of an optimization model for a Crude Distillation Unit (CDU) system at a ECOPETROL S.A. refinery in Barrancabermeja, involving the typical restrictions (flow according to pipeline capacity, pumps, distillation columns, etc) and a restriction that has not been included in bibliographic reports for this type of models: the heat integration of streams from Atmospheric Distillation Towers (ADTs) and Vacuum Distillation Towers (VDT) with the heat exchanger networks for crude pre-heating. On the other hand, ADTs were modeled with Meta models in function of column temperatures and pressures, pumparounds flows and return temperatures, stripping steam flows, Jet EBP ASTM D-86 and Diesel EBP ASTM D-86. Pre-heating trains were modeled with mass and energy balances, and design equation of each heat exchanger. The optimization model is NLP, maximizing the system profit. This model was implemented in GAMSide 22,2 using the CONOPT solver and it found new operating points with better economic results than those obtained with the normal operation in the real plants. It predicted optimum operation conditions of 3 ADTs for constant composition crude and calculated the yields and properties of atmospheric products, additional to temperatures and duties of 27 Crude Oil exchangers.

[en] This report describes the software development for the plutonium attribute verification system - AVNG. A brief synopsis of the technical solution for the measurement system is presented. The main tasks for the software development that is underway are formulated. The development tasks are shown in software structural flowcharts, measurement system state diagram and a description of the software. The current status of the AVNG software development is elucidated.

[en] The process of crude distillation impacts the economy of any refinery in a considerable manner. Therefore, it is necessary to improve it taking good advantage of the available infrastructure, generating products that conform to the specifications without violating the equipment operating constraints or plant restrictions at industrial units. The objective of this paper is to present the development of an optimization model for a Crude Distillation Unit (CDU) system at a ECOPETROL S.A. refinery in Barrancabermeja, involving the typical restrictions (flow according to pipeline capacity, pumps, distillation columns, etc) and a restriction that has not been included in bibliographic reports for this type of models: the heat integration of streams from Atmospheric Distillation Towers (ADTs) and Vacuum Distillation Towers (VDT) with the heat exchanger networks for crude pre-heating. On the other hand, ADTs were modeled with Metamodels in function of column temperatures and pressures, pump a rounds flows and return temperatures, stripping steam flows, Jet EBP ASTM D-86 and Diesel EBP ASTM D-86. Pre-heating trains were modeled with mass and energy balances, and design equation of each heat exchanger. The optimization model is NLP, maximizing the system profit. This model was implemented in GAMSide 22,2 using the CONOPT solver and it found new operating points with better economic results than those obtained with the normal operation in the real plants. It predicted optimum operation conditions of 3 ADTs for constant composition crude and calculated the yields and properties of atmospheric products, additional to temperatures and duties of 27 Crude Oil exchangers.

[en] Retrospective analysis of 137 patients with limited stage small cell lung carcinoma who received radiotherapy between 1978 and 1990 and literature review. The actuarial survival rate was 20 % at 2 years and 9 % at 5 years. It was 25 % at 2 years and 17 % at 5 years for 12 patients with surgical resection. For patients who did not undergo surgical resection, it was 20 % at 2 years and 9 % at 5 years for 96 patients belonging to group 2, while it was 14 % at 2 years and 3.5 % at 5 years for group 1. Deaths due to local relapse reached 48 % in the group treated with 45 Gy and 33 % in the group treated with 65 Gy(NS). For the 33 patients who were more than 70 years old at the time of treatment, the actuarial survival rate was 18 % at 2 years and 6 % at 5 years with death from other causes twice as high as that of patients who were less than 70 years old at the time of treatment. For the 59 patients who were less than 70 years old at the time of treatment, in whom supraclavicular node, pleural effusion or superior vena cava syndrome were not depicted and were treated with the highest dose (4 % of the total number of patients), the actuarial survival rate was 20 % at 2 years and 14 % at 5 years. Literature analysis shows that treatment of limited small cell lung cancer with chemotherapy and thoracic irradiation increased the overall survival rate from 16.5 % to 23 % at 2 years and the local control from 23 % to 48 %, in comparison with chemotherapy alone. Although these results are modest, they seem to be improved with more effective chemotherapy, especially with the association of radiotherapy and concomitant chemotherapy. (author)

[en] The place of radiation therapy for the treatment of ENT tumors has changed over the last 15 years under the influence of several factors including advances in imaging techniques; introduction of first-line chemotherapy; advances in surgery, in particular reconstructive therapy; advances in radiation therapy, including widespread use of simulators and computerized dosimetry, better control of the time factor (reduced interruption times, changes in the fractionating of external-beam radiation therapy, optimal dose rate during brachytherapy); improved knowledge of the beneficial effects of brachytherapy; use of radiosensitizing treatments; and advances in the prevention and treatment of complications of radiation therapy, in particular use of pentoxifylline and hyperbaric oxygen to treat radionecrosis. (authors). 10 refs

[en] As Merkel tumour treatment modalities are still a matter of discussion, the authors report the experience gained on 21 patients in the radiotherapy department of the Henri Mondor Hospital between 1990 and 2005. The treatment always comprised a surgical exeresis followed by radiotherapy. The authors analyse the obtained results which confirm the interest of postoperative radiotherapy. The detailed analysis of modalities (radiation type, total dose, irradiation volume) allows an optimal irradiation scheme to be proposed. Short communication

[en] An external beam therapy with two fractions a day giving 48 Gy with 16 fractions and 45 days, initially palliative, has been shown to be well adapted for a simultaneous radiosensitizing chemotherapy employment. Associated to a cisplatin, fluorouracil, etoposide and hydrea based chemotherapy, it has been applied to 46 patients with inoperable stages IV ORL tumors including 91% T4, 9% T3, 48% N2N3, 72% performance status equal or less than 2. With a 30 months observation median delay a clinical complete response at 4 months is observed in 93%, with further locoregional relapses in 38%. One year survival is 58%, 2 years 40%, 3 years 35%. These results are equal or better than those obtained with hyperfractionated, accelerated, hyperfractionated and accelerated, and classical radiotherapy. (authors)

[en] Full text: The subject of radiation doses to the general public as a result of exposition to natural materials is comparatively recent, and, as in most developing countries, has not received much attention in Colombia. The Department of Physics at National University in Bogota is just starting a master's program in medical physics and wishes to establish some lines of research in radiation related subjects. In this context we want to start a project in environmental radiation, including, but not limited to, radon and radiation associated with materials of construction. This paper describes a preliminary study of samples of sand, Portland cement and bricks used in the construction industry in Colombia. The activity of ⁴⁰K, ²²⁶Ra and ²³²Th was determined, using a high-purity germanium detector, which was calibrated using the energy peaks of a punctual Eu-152 source. The samples were milled, screened and sealed in 640 cm³ glass containers for at least 30 days to attain radioactive equilibrium. The activity of the non-punctual samples was determined by a semi-empirical method based on the method developed by Helmer (1983). From the activity in the construction materials the radium equivalent activity (Ra_eq) and annual dose rates will be evaluated and compared to the values obtained in other countries, as Egypt, Italy and Brazil. (author)