Comparison of gamma ray effects on EPROMs and E2PROMs

This paper compares the reliability of standard commercial Erasable Programmable Read Only Memory (EPROM) and Electrically Erasable Programmable Read Only Memory (E2PROM) components exposed to gamma rays. The results obtained for CMOS-based EPROM (NM27C010) and E2PROM (NM93CS46) components provide the evidence that EPROMs have greater radiation hardness than E2PROMs. Moreover, the changes in EPROMs are reversible, and after erasure and reprogramming all EPROM components restore their functionality. On the other hand, changes in E2PROMs are irreversible. The obtained results are analyzed and interpreted on the basis of gamma ray interaction with the CMOS structure

Radiation effects in polycarbonate capacitors

The aim of this paper is to examine the influence of neutron and gamma irradiation on the dissipation factor and capacitance of capacitors with polycarbonate dielectrics. The operation of capacitors subject to extreme conditions, such as the presence of ionizing radiation fields, is of special concern in military industry and space technology. Results obtained show that the exposure to a mixed neutron and gamma radiation field causes a decrease of capacitance, while the loss tangent remains unchanged

Uticaj zračenja na starenje solarnih ćelija

Široka primena fotonaponskih (PV) solarnih sistema nameće potrebu izrade solarnih ćelija od različitih materijala i struktura u cilju poboljšanja njihovih osobina i smanjenja cene solarnih ćelija i struktura. Iako efikasnost pojedinih savremenih solarnih ćelija baziranih na pn spoju, u laboratorijskim uslovima dostiže 25% (što je blizu teorijskog maksimuma od 31%), dalje poboljšanje osobina ovih uređaja danas predstavlja glavni preduslov njihove šire upotrebe. Poslednjih godina, tržište fotonaponskih uređaja je izuzetno napredovalo, uz godišnji rast od oko 30% godišnje (u poslednjih 5 godina). Iz tog razloga je proučavanje spoljašnjih činilaca koji utiču na osobine solarnih ćelija, dovodeći do pogoršanja njenih osnovnih parametara od izuzetnog značaja. U ovom radu prikazani su rezultati dobijeni analizom uticaja zračenja na starenje, pa samim tim i na kvalitet solarnih ćelija kao fotonaponskih generatora

Comparative properties of composite poly(lactic-co-glycolic acid)/poly(acrylic acid) implants synthesized using ultraviolet and gamma irradiation

Composite implants comprising a biodegradable hydrophobic polymer matrix and crosslinked hydrogel with fixed ion exchange groups are promising materials for the construction of controlled drug delivery systems. Poly(lactic-co-glycolic acid)/poly(acrylic acid) (PLGA/PAA) composite implants in our study were synthesized using the sequential application of irradiation and immersion precipitation. Precursor solutions with all functional components were dispensed into a disc-shaped non-stick mold and cured either by ultraviolet (UV) or gamma irradiation. Cured disks were subsequently immersed in the phosphate buffer saline bath to finalize phase separation and solidification of the implants. The synthesized implants were characterized by FTIR-ATR and DSC, and their basic properties such as ion exchange capacity, swelling degree, and swelling kinetics were examined. Synthesis using gamma irradiation resulted in implants with similar ion exchange capacity, but the greater swelling degree and faster swelling kinetics compared to the implants prepared with UV irradiation. Gamma irradiation also resulted in altered and less homogeneous chemical composition compared to the implants synthesized with UV irradiation. Further investigations are required to determine the differences in drug release kinetics and degradation behavior of the synthesized implants

Comparison of Gamma Ray Effects on EPROMs and E2PROMs

This paper compares the reliability of standard commercial Erasable Programmable Read Only Memory (EPROM) and Electrically Erasable Programmable Read Only Memory (E2PROM) components exposed to gamma rays. The results obtained for CMOS-based EPROM (NM27C010) and E2PROM (NM93CS46) components provide the evidence that EPROMs have greater radiation hardness than E2PROMs. More over, the changes in EPROMs are reversible, and after erasure and reprogramming all EPROM components restore their functionality. On the other hand, changes in E2PROMs are irreversible. The obtained results are analyzed and interpreted on the basis of gamma ray interaction with the CMOS structure

Mogućnosti poboljšanja karakteristika solarnih ćelija-novi pristup

Sve veća potreba čovečanstva za energijom u svakom aspektu života, donela je, pored izuzetno brzog napretka tehničke civilizacije, a samim tim i uslova života ljudi i niz teškoća. Do sada najčešće korišćena fosilna goriva dovodila su, a i sada dovode do veoma velike degradacije životne sredine, što uz činjenicu da spadaju u neobnovljive izvore energije i da su dostupne količine ove vrste goriva ograničene, predstavlja glavne nedostatke. Iz tog razloga održivi razvoj i prelazak na obnovljive izvore energije su jedina moguća dugoročna perspektiva. Fotonaponska (PV) konverzija sunčeve energije u tom pogledu predstavlja jednu od najsavremenijih tehnologija koja omogućava primenu PV sistema za različite namene. Meñutim, kao i drugi izvori energije i PV konverzija ima odreñena ograničenja koja se u prvom redu odnose na relativno nisku efikasnost PV modula. Poslednjih godina, u svetskim razmerama, postoji uočljivo povećanje ulaganja u istraživanja i razvoj fotonaponske konverzije, kako bi se što jeftinije i efikasnije proizvodile PV komponente i time bitno povećala njihova primena. U ovom radu prikazane su neke mogućnosti povećanja efikasnosti PV sistema, kako sa stanovišta klasičnih (poluprovodničkih) modula i panela, tako i upotrebe novih materijala

Određivanje temperaturske zavisnosti karakteristika solarnih ćelija merenjima frekventnog šuma i faktora idealnosti

Prilikom procesa detekcije zračenja uticaj temperature i termički indukovan šum u fotodetektorima su veoma značajni. Degradacija električnih i optičkih karakteristika fotodetektora pri povišenim temperaturama su jedan od glavnih ograničavajućih faktora za njihovu upotrebu. S obzirom na to da većina električnih procesa u poluprovodničkim uređajima u manjoj ili većoj meri zavisi od temperature, istraživanja na temperaturama višim od sobne mogu da otkriju moguće promene izlaznih karakteristika uređaja. Sa tehnološkog stanovišta, termički izazvan šum povećava minimalni signal koji može da se detektuje, što je posebno značajno za nisko energetske detektore i detektore nejonizujućeg zračenja. U ovom radu je uticaj povišene temperature proučavan preko merenja frekvetno zavisnog šuma i osnovnih izlaznih karakteristika solarnih ćelija

Construction of an autogenerator dynamic model applicable to nuclear processes

We propose a new method for constructing a mathematical model of a non-linear system in an auto-oscillation regime. The method is based on the divergence of a vector field having a constant value along the corresponding periodical motion. The variants of the obtained model could be used for describing nuclear processes that are represented by the systems of differential equations analogous to that of the presented model

Stabilization of gas-filled surge arrester's characteristics by use of ionizing radiation

U radu se razmatra stabilizacija električnog pražnjenja u gasovima primenom spoljašnjeg jonizujućeg zračenja. Razmatrano je pražnjenje modela gasnog odvodnika prenapona u pasivnom i aktivnom radnom režimu. Korišćen je originalno razvijen model gasnog odvodnika prenapona. Parametri merenja su bili pritisak gasa i međuelektrodno rastojanje. Primenjeno zračenje je bilo: α-zračenje, γ-zračenje, X-zračenje i neutronsko zračenje. Merenja su vršena pod dobro kontrolisanim laboratorijskim uslovima. Kombinovana merna nesigurnost primenjenog postupka procenjena je na manje od 5%. Dobijenim rezultatima je dato teorijsko tumačenje. Osnovni rezultat je da jonizujuće zračenje ne mora nužno da ograničava funkciju gasnih odvodnika prenapona, već da je, pod određenim uslovima, poboljšava.This paper investigates the stabilization of electrical discharges in gases by means of external ionizing radiation. Discharges in a gas-filled surge arrester model were studied in both passive and active regimes of the device. An originally developed model of the gas-filled surge arrester was used. Gas pressure and the interelectrode gap were the variable parameters in our measurements. Applied radiation types included α-particles, γ-rays, X-rays, and neutrons. Measurements were performed under highly controlled laboratory conditions. The combined measurement uncertainty of the applied procedure was estimated as being under the 5% level. The results obtained are followed by a theoretical explanation. The crucial result is the conclusion that ionizing radiation does not necessarily degrade the gas-filled surge arrester's functionality but that it, rather, improves it under certain conditions