Kinetic study of Mongolian coals by thermal analysis

Thermal analysis was used for the thermal characterization of the coal samples. The experiments were performed to study the pyrolysis and gasification kinetics of typical Mongolian brown coals. Low rank coals from Shivee ovoo, Ulaan ovoo, Aduun chuluun and Baganuur deposits have been investigated. Coal samples were heated in the thermogravimetric apparatus under argon at a temperature ranges of 25-1020ºC with heating rates of 10, 20, 30 and 40ºC/min. Thermogravimetry (TG) and derivative thermogravimetry (DTG) were performed to measure weight changes and rates of weight losses used for calculating the kinetic parameters. The activation energy (Ea) was calculated from the experimental results by using an Arrhenius type kinetic model

Investigation on pyrolysis of some organic raw materials

We have been working on pyrolysis of some organic raw materials including different rank coals, oil shale, wood waste, animal bone, cedar shell, polypropylene waste, milk casein and characterization of obtained hard residue, tar and pyrolytic water and gas after pyrolysis. The technical characteristics of these organic raw materials have been determined and the thermal stability characteristics such as thermal stability indices (T5% and T25%) determined by using thermogravimetric analysis. The pyrolysis experiments were performed at different heating temperatures and the yields of hard residue, tar, pyrolysis water and gaseous products were determined and discussed. The main technical characteristics of hard residue of organic raw materials after pyrolysis have been determined and the adsorption ability of pyrolysis hard residue and its activated carbon of organic raw materials also determined. The pyrolysis tars of organic raw materials were distilled in air condition and determined the yields of obtained light, middle and heavy fractions and bitumen like residue with different boiling temperature. This is the first time to investigate the curing ability of pyrolysis tars of organic raw materials for epoxy resin and the results of these experiments showed that only tar of milk casein has the highest (95.0%), tar of animal bone has certain (18.70%) and tars of all other organic raw materials have no curing ability for epoxy resin

HYPERMEDIA COMPUTER-BASED EDUCATION IN SOCIAL WORK EDUCATION- * 0

tterson and J oan ne Ya f fe Hypermedia computer-based education (CBE) is an emerging information ' * ' technology that makes possible user-directed, nonsequential exploration of, and interaction with, information presented through a variety of media including text, animation, graphics, sound, and video. This article describes hypermedia CBE and briefly reviews the research on its instructional efficacy. A synopsis of the theoretical foundation covers cognitive theory concepts of information networks and associative learning, web teaching.<..7s>j: principles, andragogical theory as it relates to social work education, and hypermedia CBE structure. Examples of current and potential applications in social work education demonstrate that hypermedia CBE can emulate the dynamic, iterative learning process of knowledge acquisition, knowledge testing, and content integration through practice simulation. T he c o n veya nc e of the social work knowledge base is a multifaceted task in social work education. Informa tion is transferred in the classroom, through texts, among peers, and in field placements. In recent years, computer-based education (CBE) has assumed a small role in the dissemination of infor mation within social work educatio

Análisis de estado y evaluación estructural de recovas semicubiertas en la nueva ciudad de Federación

Dentro de las diversas construcciones de La Nueva Ciudad de Federación, ubicada en el noreste de la Provincia de Entre Ríos, se distinguen diecisiete recovas a manera de rasgo iconográfico de la ciudad. Realizadas a lo largo de su acceso, y a ambos lados de su calle principal, estas obras características fueron realizadas en el año 1970 utilizando hormigones premoldeadosy se constituyen mediante bases, columnas, vigas y canalones de gran porte. Este trabajo surge como efecto del colapso producido sobre una sección localizada de una de ellas y consta, en principio, de un análisis de estado en conjunto y una evaluación estructuradle estas diecisiete estructuras. Surgen así, datos sobre sus hormigones constitutivos y su estado actual, datos constructivos y un programa efectivo de mantenimiento durante su vida útil