Volume 22, No. 4 (2016)

MICRO DETERMINATION OF DOPAMINE IN BIOLOGICAL SAMPLES BY COUPLING REACTION

AHMED JASSIM MUKLIVE AL-OGAIDI (*1,2)

The paper presents the development of an analytical method to determine dopamine by coupling reaction with diazotized solution of 4-Aminoantipyrine in basic media to give a compound with a single azo dye salt having orange color soluble in water. A calibration curve for a range of concentration (9.14x10-5 – 2.28x10-3 μg.mL-1) was realized and the value of molar absortivity was 1.5x103 L.mol-1.cm-1, with a relative standard deviation more than 1.26% and a recovery 98.77%. As we study the nature of the azo dye by mole fraction method, from the practical value we found that the mole fraction of the dye compound is 1:1 (dopamine: 4- amino antipyrine) and the stability factor reach to 1.4x106 L.mol-1. The described procedure is very simple, low-time-consuming, provides high throughput of examined samples, and could be used for routine screening and confirmatory analyses as well. The method was successfully validated to the analysis of the dopamine in biological samples.

OPTIMIZATION AND ENERGY SAVING WHEN CHOOSING THE SITE OF INSTALLATION OF A CRUSHING STATION IN A MOUNTAINOUS TERRAIN CASE OF THE DJBEL EL BORDJ CAREER, SIDI BELABBAS, ALGERIA

RACHID KHEBBAB(1), SAMIR REMLI(2,3), ISSAM ROUAIGUIA(2), AISSA BENSELHOUB (*4)

In open pit or underground mines and quarries, especially in mountainous terrain, the choice of the perfect place to install a crushing station requires a decision finalized by a detailed study of the areas close to the quarries such as the water drainage, the morphology of the deposit, the installed capacity, the opening mode of the deposit etc. For this purpose, in this article we will propose an installation of the crushing station of the quarry Djbel El Bordj which serves to save energy throughout the life of the quarry, and also will gain the transportation distance of the stones that determines the number of dumpers needed for planned production.

DETERMINATION OF BACKPACK MASS LIMIT FOR STUDENTS IN A UNIVERSITY IN ABEOKUTA, SOUTHWESTERN NIGERIA

SALAMI OLASUNKANMI ISMAILA (*1)

The aim of this study was to use the Froude number to determine the mass of the backpack that a student should carry in tertiary institutions. A model was developed using the Froude number with leg length and power of the students as inputs. It was established that a student in tertiary institutions should carry a backpack with a mass of at most 10 % of the body mass. Similar studies are recommended for primary and secondary schools.

TOWARDS IMPLEMENTATION OF INNOVATIVE METHODOLOGIES IN CONSTRUCTION ENGINEERING IN CHILE. A CASE STUDY

PEDRO MUÑOZ(1), VIVIANA LETELIER(2), LUMINITA BIBIRE (*3), LUIS MUÑOZ(4)

The demands of society are changing rapidly, which in turn enhances the need to prepare qualified professionals with up-dated skills and competencies. Due to this fact, universities must be able to develop new teaching strategies which should be focused, not only in the curricula, but on teaching methodology. This paper shows an experience, developed for the subject matter of electrical installations within the Construction Engineering degree of the Autonomous University of Chile. The aim is to show a Project-Based Learning model using cooperative as well as collaborative strategies, while taking into ac-count both the particular situation of higher education in Chile and the socio-cultural factors of students. The methodology and tools used for its implementation are described and related to obtained results within the Chilean context. It concludes that this teaching method contributes with learning enhancement in terms of strengthening of technical and transversal competencies, while also resulting in a significant improvement of grades, as well as a marked reduction in the absenteeism rate.

STUDIES ON THE APPLICATION OF HOLLOW FIBER MEMBRANES IN THE FIELD OF ULTRAFILTRATION

LAURENȚIU TATARU (*1), VALENTIN NEDEFF(1, 2), NARCIS BARSAN(1), MIRELA PANAINTE-LEHADUS(1), EMILIAN MOSNEGUTU(1), DANA-ALEXANDRA CHITIMUS(1)

This study is a review of knowledge and understanding of organic fiber membrane behavior in wastewater ultrafiltration processes. Current research is increasingly focusing on the use of state-of-the-art technologies for the elimination of pollutants in water and the use of membranes. This study focuses on testing hollow fiber organic membranes for the ultrafiltration process as a precursor to osmosis processes. The major advantages of ultrafiltration are the elimination of many small organic and inorganic compounds from the water, which cannot be eliminated in microfiltration processes, offering superior quality water. This review highlights the effectiveness of organic membranes from hollow fibers in relation to the dependence between filtering parameters and those related to the membrane type structure, respectively the membrane structure of the polyacrylonitrile. The results of the study on the testing of such membranes have shown that filtration efficiency increases inversely with the degree of fouling on the surface of the membrane; the permeate quality being superior in the early stages of the membrane lifecycle, decreasing with increasing use time. In other words, the aging of the membrane decreases the volume of the permeate and at the same time changes the dependence of the parameters: pressure, temperature, flow if it is desired to obtain the same amount of permeate. Finding the best solutions for streamlining the membrane structure and running under the best conditions will be presented in the current paper.

EFFICIENCY OF WATER FILTERING PROCESS DEPENDING ON THE FILTER LAYER POROSITY AND FLOW - A MATHEMATICAL MODEL

OANA TIRTOACA (IRIMIA)(*1), VALENTIN NEDEFF(1, 2), MIRELA PANAINTE-LEHADUS(1), CLAUDIA TOMOZEI(1)

Mathematical modeling represents a challenge for any researcher or engineers that working in the field of applied sciences. The experimental approach to the water filtering process allowed achieving and verification a three-dimensional mathematical model, depending on the intake flow of the filter, the porosity of the filter layer and the nature of the filter layer. The mathematical model was developed and verified using the software Table Curve 3D. It was found that the mathematical model proposed offers a viable and robust method for determining the mechanical filtration efficiency of water.