Numar curent

Volumul 12 (2021), Nr. 2

Sisteme CBTC de supraveghere a traficului feroviar
CBTC systems for railway traffic supervisory
Alexandru BADEA, Gabriel POPA, Monica VALU Constantin BIBIRE, Claudiu-Nicolae BADEA, George DUMITRU

Aceasta lucrare ofera o imagine detaliata a proiectului pentru o reteaua CBTC - „Communications-based train control” (sistem de siguranta si control a circulatiei trenului bazat pe comunicatii / transmiterea datelor - semnalelor) pentru circulatia feroviara. In lucrare au fot evidentiate utilizarile in modul „ad-hoc” a sistemelor Wi-fi. Un tren poate pur si simplu sa transmita pachete de date. Cand un AP - „Access Point (punct de acces) primeste un pachet, il poate redirectiona catre urmatorul AP si asa mai departe, putand crea astfel un lant de AP-uri. La capatul lantului, dupa ce pachetele au ajuns la destinatie, pentru minimizarea interferentelor, transmisia datelor se face pe frecvente multiple. In plus, redundanța este asigurata de un AP care nu numai ca trimite semnalul catre cel mai apropiat vecin, ci si catre suma tuturor celorlalti vecini apropiati. Cercetarile dezvoltate in acest domeniu analizeaza performanta acestui nou proiect de transmitere a datelor utilizand simularea pe calculator. Un numar mare de scenarii au fost analizate cu scopul de a examina rezistența, redundanta si scalabilitatea sistemului.
This paper provides a detailed picture of the project for a CBTC network - "Communications-based train control" (safety and control system for train traffic based on communications / data transmission - signals) for rail traffic. The paper highlighted the "adhoc" use of Wi-Fi systems. A train can simply transmit data packets. When an AP - "Access Point" receives a packet, it can redirect it to the next AP and so on, creating a dates flux of APs. At the end of the chain, after the packets have reached their destination, to minimize interference, the data is transmitted on multiple frequencies. In addition, redundancy is ensured by a PA that not only sends the signal to the nearest neighbor, but also to the sum of all other close neighbors. The research developed in this field analyzes the performance of this new data transmission project using computer simulation. A large number of scenarios were analyzed in order to examine the strength, redundancy and scalability of the system.

CBTC systems for railway traffic supervisory

Particularitati ale circuitelor de forta de curent continuu specifice locomotivelor electrice Seria BB 16500
Specifications of dc power circuits specific to electric locomotives BB 16500 series
Melania TUDOSE DUMITRU, Victor Mihai POPA, Alexandra DRAGNEA, Adrian DUTAN, Adrian Ioan MUNTEAN, George DUMITRU

Locomotivele electrice produse de „Alstom” din seria BB 16500 si locomotivele electrice din seria BB 25500 sunt versiuni ale acelorasi variate de locomotive respectiv locomotivele electrice seria BB 17000 si seria BB 8500, care sunt identice. Acestea au fost alocate in Franta, la depoul Montrouge din Paris (regiunea de vest), precum si depoul din Dôle (regiunea de sud - est) au primit prima locomotiva noua din seria BB 25500, in vara anului 1964. In depoul Montrouge, sosirea locomotivelor s-a produs simultan cu sporirea numarului de km de linie electrificata la tensiunea de 25 [kV] si 50 [Hz] a liniei Le Mans - Laval - Rennes. In regiunea Franche - Comté, locomotivele seria BB 25500 din depoul Dôle au inlocuit locomotivele seria BB 16500 si seria BB 12000, care au fost utilizate pana atunci sub liniile electrificate la tensiunea de 25 [kV] si 50 [Hz]. În Romania, au fost importate si sunt patru unitați din seria de locomotive BB 16500 fiind redenumite 41-6 si doisprezece unitați din seria de locomotive BB 25000, care au fost redenumite 42-55.
The electric locomotives produced by 'Alstom' in the BB 16500 series and the electric locomotives in the BB 25500 series are versions of the same variety of locomotives, namely the BB 17000 and BB 8500 series electric locomotives, which are identical. They were allocated in France at the Montrouge depot in Paris (western region) and the Dôle depot (south-eastern region) received the first new locomotive in the BB 25500 series in the summer of 1964. In the Montrouge depot, the arrival of the locomotives occurred simultaneously with the increase of the number of km of electrified line at the voltage of 25 [kV] and 50 [Hz] of the Le Mans - Laval - Rennes line. In the Franche-Comté region, the BB 25500 series locomotives in the Dôle depot replaced the BB 16500 series and BB 12000 series locomotives, which had until then been used under electrified lines at 25 [kV] and 50 [Hz]. In Romania, were imported and are four units from the series of locomotives BB 16500 being renamed 41-6 and twelve units from the series of locomotives BB 25000, which were renamed 42-55.

Specifications of dc power circuits specific to electric locomotives BB 16500 series

Unele tipuri de concasoare cu falci pentru prelucrarea agergatelor minerale in laborator
Some types of jaw crushers for mineral aggregates processing in laboratory
Amelitta LEGENDI, Cristian PAVEL

Aceasta lucrare prezinta cateva tipuri noi de concasoare cu falci utilizate in prezent pentru a deservi operatiile de prelucrare a agregatelor minerale în cadrul laboratoarelor din industria materialelor de construcţii. Astfel, se prezinta principalele materiale ce pot fi procesate cu ajutorul acestor tipuri de concasoare cu falci, aspecte privind precoesul tehnologic de strivire, avantajele si dezavantajele aferente, precum si performanţele ce pot fi atinse de aceste echipamente.
This paper focuses several new types of jaw crushers currently used to service mineral aggregate processing operations in laboratories in the construction materials industry. Thus, the main materials that can be processed using these types of jaw crushers, aspects regarding the technological pre-crushing, the advantages and disadvantages, as well as the performances that can be achieved by these equipments are presented.

Some types of jaw crushers for mineral aggregates processing in laboratory

Dinamica masinilor de ridicat. Influenta dinamicii ridicarii sarcinilor asupra stabilitatii macaralelor turn
Dynamics of lifting machines. The influence of load lifting dynamics on the stability of tower cranes
Cristina SESCU-GAL, Catalin FRANCU

Macaralele sunt instalatii esentiale sectorului de constructii – montaj. Fie ca vorbim de utilizarea clasica a acestora in construirea unui obiectiv, in activitatea de interventii asupra constructiilor, la montarea unor echipamente sau structuri dar si ca utilaje inglobate in sisteme BIM, cunoasterea comportarii dinamice a acestora este importanta in egala masura pentru proiectant cat si pentru utilizator. Scopul urmarit in cercetarile din domeniu sunt caracteristice stabilirii factorilor perturbatori datorat functionarii mecanismelor, a comportarii structurii portante supusa solicitarilor dinamice precum si in asigurarea stabilitatii in exploatare. Prezenta lucrare este centrata pe determinarea modului in care miscarea de ridicare a sarcinilor de pe o suprafata de sprijin influenteaza stabilitatea la rasturnare a acestor instalatii. De retinut ca o influenta majora asupra stabilitatii o constituie cazurile particulare regasite in situatia descarcarii instantanee a sarcinii si in cazul actiunii neuniforme a vantului, situatii care fac obiectul unor tratate viitoare.
Cranes are essential installations for the construction - assembly sector. Whether we are talking about their classic use in the construction of an objective, in the activity of interventions on constructions, in the installation of equipment or structures but also as equipment embedded in BIM systems, knowing their dynamic behavior is equally important for the designer and for user. The aim pursued in the researches in the field are characteristic for establishing the disturbing factors due to the functioning of the mechanisms, the behavior of the load-bearing structure subject to dynamic demands as well as in ensuring the stability in operation. This paper focuses on determining how the lifting movement of loads on a support surface influences the overturning stability of these installations. It should be noted that a major influence on stability is the particular cases found in the situation of instantaneous discharge and in the case of uneven action of the wind, situations which are the subject of future treaties.

Dynamics of lifting machines. The influence of load lifting dynamics on the stability of tower cranes

Raspunsul dinamic al articulatiei cotului sub actiunea vibratiilor – metode de studiu
Analysis of the dynamic response of the elbow joint under the action of vibrations – study methods
Marina DOGARU, Cristian PAVEL Radu PANAITESCU-LIESS

Preocuparile noastre cu privire la influenta vibratiilor asupra corpului uman au fost continuate prin realizarea unor cercetari experimentale efectuate de catre colega noastra Marina Dogaru in cadrul ICECON si in cadrul Facultatii de Utilaj Tehnologic, cu scopul de a determina raspunsul articulatiilor corpului omenesc sub actiunea vibratiilor. In acest scop s-au utilizat senzori profesionali si accelerometre compatibile cu placutele de dezvoltare Arduino.
Our concerns about the influence of vibrations on the human body were continued by our colleague Marina Dogaru at ICECON and the Faculty of Technological Equipment, in order to determine the response of human body joints under the action of vibrations. For this purpose, professional sensors and accelerometers compatible with Arduino development boards were used.

Analysis of the dynamic response of the elbow joint under the action of vibrations – study methods

Cercetari experimentale privind obtinerea unor structuri biocompozite cu proprietati fonoabsorbante
Experimental research on obtaining biocomposite structures with soundproofing properties
Andreea Silvia NITU, Radu IATAN, Ion DURBACA

Lucrarea abordeaza posibilitatea obtinerii unor structuri biocompozite, din deseuri, care prezinta un coeficient crescut de absorbtie a sunetului, de diferite dimensiuni si compozitii. Se porneste de la faptul ca valoarea acestui coeficient este influentata direct de natura componentelor utilizate pentru obtinerea biocompozitelor si de grosimea straturilor. Determinarea coeficientului de absorbtie in cadrul experminentului propus s-a efectuat prin intermediul tubului Kundt. Analizand rezultatele obtinute in urma determinarii coeficientului de absorbtie pentru structurile biocompozite obtinute in cadrul experimentului, se poate afirma ca din aceste structuri biocompozite se pot realiza panouri fonoabsorbante care pot fi utilizate la scara larga pentru diminuarea zgomotului in diferite incaperi.
The paper addresses the possibility of obtaining biocomposite structures from waste, which have an increased coefficient of sound absorption of different sizes and compositions. It starts from the fact that the value of this coefficient is directly influenced by the nature of the components used to obtain biocomposites and by the thickness of the layers. The determination of the absorption coefficient in the proposed experiment was performed using the Kundt tube. Analyzing the results obtained by determining the absorption coefficient for biocomposite structures obtained in the experiment, it can be stated that from these biocomposite structures can be made sound-absorbing panels that can be widely used to reduce noise in different rooms.

Experimental research on obtaining biocomposite structures with soundproofing properties

Caracteristici tehnice ale panourilor fonoabsorbante si fonoizolatoare
Technical characteristics of sound-absorbing and soundproofing panels
Oana TONCIU

Materia prima principala din cauciuc utilizata la fabricarea panourilor consta in anvelopele uzate ELT (End – Life – Tires) marunțite si clasate pe sorturi compozite. In amestecul de materiale din care va rezulta in final cauciucul utilizat la fabricarea panourilor fonoizolatoare si fonoabsorbante, se introduc agenți de legare (liant poliuretanic) si agenti chimici de ignifugare. Prin reutilizarea cauciucului aflat in alcatuirea anvelopelor folosite se aduce un aport considerabil la reducerea depozitelor de deseuri si la eliminarea riscului de mediu pe care l-ar constitui anvelopele uzate abandonate in natura. De asemenea, in lucrare vor fi prezentate principalele caracteristici acustice determinate experimental pe panourile fonoizolatoare si fonoabsorbante. In acest fel, rezulta ca acestea corespund cerintelor de performanța si ca pot fi utilizate potrivit scopului urmarit.
The main rubber raw material recycled in the manufacture of the panels consists of used ELT (End – Life – Tires) tires shredded and sorted into composite aprons. The reuse of used rubber makes a considerable contribution to reducing waste landfills and eliminating the environmental risk posed by used tires abandoned in nature. Also, in the paper will be presented the main acoustic characteristics determined experimentally on the sound-insulating and sound absorbing-panels. In this way, it follows that they meet the performance requirments and can be used according to the intended purpose.

Technical characteristics of sound-absorbing and soundproofing panels

 
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