Volume 1 (2000)

Articles

STUDII CU PRIVIRE LA SINTEZA SI STRUCTURA UNOR DERIVATI AI ACIZILOR FENOLICI

GEORGESCU MILPOMENIA, LEONTE MIRCEA

In the paper, the aromatic Mannich bases were prepared using ß-resorcylic acid, pyrogallol carboxylic acid and its methylic ester, as well as gentysic acid. The Mannich bases structures has been determined chemically and physicochemically. The study of antioxidizing action was performed by using sun-flower broth.

STUDIUL INFLUENTEI APEI MAGNETICE FOLOSITE LA IRIGARE ASUPRA COMPOZITIEI CHIMICE A UNOR PLANTE LEGUMICOLE

CĂLIN MARIA, POPA GHEORGHE, SERPE MIHAELA

The experiments of irrigation with magnetic water were made in the Vegetable Research Station Bacau during 1990 - 1994. The use of magnetic water determined the increase of the harvest content in sodium with 8.30 mg/100 g (tomatoes) and vitamin C with 2.94 g/100 g (onions). The use of magnetic water determined the decrease of the harvest content in sugar with 2 mg/100 g (onions); vitamin C (pepper, tomatoes, carrots); mineral matter (pepper, onions, carrots); sodium (pepper, onions, carrots).

THE STUDY OF “IN VITRO” MULTIPLICATION OF SUGAR BEET (BETA VULGARIS L.)

PRISECARU MARIA (1), GHEORGHIŢĂ GOGU (1), FÎNARU ADRIANA (2)

By using the basal medium MS (Murashige - Skooge, 1962) supplemented with various concentrations of auxins and cytokinins, callus cultures were obtained from all the 19 genotypes tested by using cotyledons, hypocotyls, petioles and leaves as sources of explants. The best results were obtained on the medium with cytochinins (BAP, Kinetin) 5mg/L, associated with 2,4-D 0.1mg/L. The green, friable callus transferred on the regeneration medium (BAP 5mg/L, NAA 0.1mg/L, GA3 0.05mg/L,) developed buds and shoots. By transferring the shoots on the medium with IAA 2mg/L, and Kinetin 0.02mg/L, all shoots developed roots after approximately 3 weeks. The complete pants regenerated were successfully adapted to the septic conditions, both in the laboratory and in the greenhouse. Passing off explants directly on the regeneration medium showed their answering ability through direct organogenesis. The intensity of the direct and indirect organogenesis process was satisfactory, despite of nature of initial explants. The genotypes Pl6, Pl7 (diploid) and SG29 (tetraploid) excelled in producing a high yield of regenerates.

MATERIALE SUPORT PENTRU IMOBILIZAREA ENZIMELOR

ALBU ANGELA

The immobilization of the enzymes is one of the most modern processes in the food industry. There are a lot of carriers for immobilization, both of inorganic and organic nature. To choose a carrier is a problem not very easy to solve because it has to protect the enzyme against other factors and to let the enzyme to catalyze the process.

REACTOARE ENZIMATICE CU UMPLUTURA

ALBU ANGELA

This paper is concerning about the description of a reactor with fix packed bed from the general standing point and of the mathematical model. This type of reactor is used in most of the applications whith immobilised enzymes.

EFECTUL UNOR TRATAMENTE FIZICO – CHIMICE ASUPRA CONSERVABILITATII DROJDIEI DE PANIFICATIE

DABIJA ADRIANA

The effect of some physical (shaking, aeration) and chemical treatments (acid, salts, oxidants) upon the fermentative capacity of Saccharomyces cerevisiae was studied both for a yeast suspension and a compressed yeast industrially produced by S.C. „Bere-Lichior Margineni” S.A. Bacau. Using 0.5 g H2O2/100 g biomass, which have an oxidant effect upon the SH group and which stimulate the intracellular protease, or 50 g formic acid/100 g biomass, which has a bacteriostatic effect, the shelf life of the yeast was extended with a period of 12-22 days.

POSIBILITATILE DE CONTAMINARE MICROBIOLOGICA A PRODUSELOR ALIMENTARE DE ORIGINE ANIMALA DE-A LUNGUL FLUXULUI TEHNOLOGIC

PUIU-BERIZINŢIU LĂMÎIŢA

In concordance with technical literature data, this study is pointing the importance of respecting the hygiene regulations on flow sheet of the food products of animal origin. In this context, the work presents the microbiological contamination possibilities of the foods – milk, meat and meat prepared – on the flow sheet, emphasizing the critical -contamination points.

CERCETARI PRIVIND CALCULUL STERILIZARII PRODUSELOR ALIMENTARE PRIN TRATARE TERMICA

FLORESCU IULIAN(1), STUPU DANIELA(2)

Le travail propose une méthode pratique de détermination de la stérilisation des produits alimentaires par le traitement thermique avec l’utilisation d’une méthode graphique. Le diagramme a été obtenu après les expérimentations pour les conserves. Les coefficients de calcul ont été détermine avec ce diagramme.

CONSIDERATII PRIVIND FORMAREA AMBALAJELOR DE UNICA FOLOSINTA ÎN INDUSTRIA ALIMENTARA

FLORESCU IULIAN(1), STUPU DANIELA(2)

RÉSUMÉ: Le travail propose une nouvelle installation pour obtenir des produits de papeterie d’unique utilisation pou l’industrie alimentaire qui utilisent une technologie moderne avec le vide, ainsi que la méthode de calcul pour la grosseur des support des fibres qui se déposent.

STRATEGIA DE MEDIU ÎN JUDETUL BACAU

MĂCĂRESCU BOGDAN

The paper comprises the plan – Environmental Strategy of Bacau – which includes the way of analysis and achievements. The main targets that we are having in view are presented in tables 3 - 5. The concrete action plan is made up on the basis of the negotiations with the industries giving us the guarantee of its fulfillment. The main stages are: minimizing losses, updating, achieving the depollution devices.

MODEL MATEMATIC PENTRU CALCULUL DISPERSIEI UNUI POLUANT EMIS DIN SURSE MULTIPLE

NAGACEVSCHI VALERIU, MACOVEANU MATEI

The selected mathematical modeling is based on a classical “Gaussian” model. Are proposed multiple sources of pollution. The control of pollution is made by a variable number of receivers. Each receiver can locally measure the concentration of pollutant from each source, or can indicate the total local concentration. The atmospherical conditions, as the pollution of the atmosphere can vary, being registred into a period of 24 hours. The experimental dates of the model involve the localization on the ground of all sources of pollution, as of all receivers. It was elaborated a computer program for the monitoring simulation of the atmospheric pollution.

DEPOLLUTION D‘EFFLUENTS AQUEUX PAR COMPLEXATION DU CUIVRE ET DU COBALT AVEC DES EXTRACTANTS ORGANOPHOSPHORES

DIDI MOHAMED-AMINE(1), AZZOUZ ABDELKRIM(2)

The performances of trioctyle-phosphine oxide (TOPO) and tributyle phosphite (TBP’) in the removal of Cu and Co from aqueous wastes was investigated. The optimization study achieved highlighted the occurrence of a synergy effect in the Cu liquid-liquid extraction using a mixture (TOPO + lauric acid). Extraction yields of ca. 75% by cycle were obtained.

PROCES ECOLOGIC DE DEPUNERE A CROMULUI DIN ELECTROLITII PE BAZA DE CROM TRIVALENT

BORCEA AURICA(1), BELDIE CAMELIA(2)

Due to the excellent corrosion and wear resistant properties of chromium deposits, researches to deposit chromium coatings of high quality from environmentally more acceptable Cr (III) electrolytes, in order to replace the highly toxic chromium (VI) processes currently employed have been made. The effects of composition and operating conditions on deposits quality and current efficiencies were investigated in a trivalent chromium plating process containing chromium alum, sodium citrate and sodium thiocyanate.

CONSIDERATII PRIVIND DEGAZAREA SI REGLAREA pH-ULUI APEI DE ALIMENTARE A CAZANELOR DE ABUR

GAVRILĂ LUCIAN(1), GAVRILĂ DANIELA(2)

The paper presents a case study concerning the influence of the boiler feed water characteristics (mainly pH and dissolved oxygen) on the corrosion processes that may occur in the steam generation plant. The role of ammonia as pH regulator is analyzed, evidencing the operating problems created by ammonia overdosing in the feed water. Several solutions for boiler’s operation improvement are presented.

ASPECTE PRACTICE PRIVIND TRATAREA APELOR DE RACIRE RECIRCULATE DINTR UN COMPLEX DE ÎNGRASAMINTE AZOTOASE

GAVRILĂ LUCIAN(1), GAVRILĂ DANIELA(2)

The paper presents a case study on the consequences of circulating cooling water treatment on the operating conditions of a urea plant. Water treatment lead to reduced fresh water and energy consumption, corrosion mitigation, scale inhibition and microbiological slime fouling decrease.

CONSIDERATII TEHNICE PRIVIND PROCESELE DE COROZIUNE POSIBILE ÎNTR-O INSTALATIE DE OBTINERE SI UTILIZARE A ACIDULUI AZOTIC

JUMANCA VALERIU, CIOBANU DOMNICA

This work propose on the basis of theoretical and experimental studies, the elucidation and clearing up of some corrosion problems, in unforeseeable conditions, for the recycling of nitric acid used in the manufacture of several organic products.

CONVERTOR ANALOG - NUMERIC CU DAC08

ROTAR DAN, LIVINŢI PETRU

In the design of management information and control systems, a good deal of attention is devoted to what are called peripherals – facilities external to central processor (or computer), whose purpose is to gather, reduce and convey data from source to sink. In this paper is described an feedback analog-to-digital converter build whit DAC08 digital-to-analog converter. The structure of the analog-to-digital converter are presented and mode of operation are analyzed. The experimental results are presented and the time performances are considered.

CRESTEREA PRECIZIEI DE POZITIONARE LA SISTEMELE CU MOTOARE PAS CU PAS PRIN COMANDA MIXTA PASI - MICROPASI

ROTAR DAN, LIVINŢI PETRU

The switched reluctance motor (SRM) is currently the focus of increasing attention because of its begin operational features and its attractive control mechanisms. Its fault tolerant make the use of the SR machine convenient in applications requiring high reliability. This paper presents a control method for a SRM, based of both steps and micro steps control. The control method is described in which a digital-to-analog converter is used to regulate the current of the phase of SR motor. This method make to increase the precision of the positioning systems.

AUTOMATIZAREA INSTALATIEI DE AZOT DE LA COMBINATUL DE ÎNGRASAMINTE CHIMICE BACAU

ROTAR DAN, LIVINŢI PETRU

RÉSUMÉ: Dans cet ouvrage on présentera l‘automatisation de la installation de production de l’azote liquéfié de C.I.Ch. Bacau. L’installation électrique d’automatisation est composé de tableau de commande, l’appareillage pour mesure des paramètres technologiques et des câbles aux connexions.

CONSIDERATII PRIVIND CONDUCEREA PROCESELOR CU AJUTORUL CALCULATOARELOR IBM-PC

ROTAR DAN, LIVINŢI PETRU

The advent of digital technologies has brought a new dimension to process control. The rapid progress in computer and digital electronics go to replace the analog control with the digital control. This paper describes a way to control of the process with an IBM-PC compatible computer. After a brief description of the microcomputers the interface process is described. The schedule of the process interface and the theses performances are described. An example of implementation of the process control with the IBM-PC compatible computer are presented and the performances are discussed.

APARAT PENTRU PROTECTIA LA TEMPERATURA A LAGARELOR DE LA MASINILE DE FABRICAT HÂRTIE

ROTAR DAN, LIVINŢI PETRU

RÉSUMÉ: L’ouvrage présente la solution constructive pour réalisation du appareil pour protection au température à des paliers des machines pour fabriqué le papier. L’appareil est compose de l’indicateur numérique de température et le programmeur pour la limite supérieure de température.

COMANDA AUTOMATA ÎN SISTEM MICROPROCESOR A ACTIONARILOR ELECTRICE A UTILAJELOR CU VITEZA REGLABILA

PUIU-BERIZINŢIU MIHAI, ROTAR DAN

The paper presents the way of use a micro system for the rotation speed control of asynchronous motor for electric drives with adjustable speed. It is treating the case of a system with closed-loop control of speed/torque and magnetic flux by the method of vector control with orientation on the rotor flux. It is shows the base configuration of a micro system with 8086 microprocessor duty to execution he control laws for speed and rotor flux with statoric currents references elaboration for PWM - inverter’s command used for the asynchronous motor’s supply.

RADUCTOR NUMERIC DE TURATIE PENTRU MASINI ELECTRICE

LIVINŢI PETRU, ROTAR DAN

RÉSUMÉ: The paper presents the way of use a micro system for the rotation speed control of asynchronous motor for electric drives with adjustable speed. It is treating the case of a system with closed-loop control of speed/torque and magnetic flux by the method of vector control with orientation on the rotor flux. It is shows the base configuration of a micro system with 8086 microprocessor duty to execution he control laws for speed and rotor flux with statoric currents references elaboration for PWM - inverter’s command used for the asynchronous motor’s supply.