Sodium channel inactivation kinetics of rat sensory and motor nerve fibres and their modulation by glutathione

Na+ channel currents of rat motor and sensory nerve fibres were studied with the patch-clamp technique on enzymatically demyelinated axons. Differences between motor and sensory fibres in multi-channel inactivation kinetics and the gating of late single-channel currents were investigated. In the axon-attached mode, inactivation of multi-channel Na+ currents in sensory axons was best fitted with a single time constant while for motor axons two time constants were needed. Late single-channel currents in sensory axons were characterized by short openings whereas motor axons exhibited additional long single-channel openings. In contrast, in excised, inside-out membrane patches, no differences between motor and sensory fibres were found: in both types of fibre inactivation of multi-channel Na+ currents proceeded with two time constants and late single-channel currents showed short and long openings. After application of the reducing agent glutathione to the cytoplasmic side of excised inside-out patches, inactivation of Na+ currents in both motor and sensory fibres proceeded with a single, fast exponential time constant and late currents appeared with short openings only. These data indicate that the axonal metabolism may contribute to the different inactivation kinetics of Na+ currents in motor and sensory nerve fibres

Sodium channel inactivation kinetics of rat sensory and motor nerve fibres and their modulation by glutathione

Na+ channel currents of rat motor and sensory nerve fibres were studied with the patch-clamp technique on enzymatically demyelinated axons. Differences between motor and sensory fibres in multi-channel inactivation kinetics and the gating of late single-channel currents were investigated. In the axon-attached mode, inactivation of multi-channel Na+ currents in sensory axons was best fitted with a single time constant while for motor axons two time constants were needed. Late single-channel currents in sensory axons were characterized by short openings whereas motor axons exhibited additional long single-channel openings. In contrast, in excised, inside-out membrane patches, no differences between motor and sensory fibres were found: in both types of fibre inactivation of multi-channel Na+ currents proceeded with two time constants and late single-channel currents showed short and long openings. After application of the reducing agent glutathione to the cytoplasmic side of excised inside-out patches, inactivation of Na+ currents in both motor and sensory fibres proceeded with a single, fast exponential time constant and late currents appeared with short openings only. These data indicate that the axonal metabolism may contribute to the different inactivation kinetics of Na+ currents in motor and sensory nerve fibres

Distributed control of manufacturing resources: Security related issues

Paradigma industrije 4.0 diktira visoko efikasnu i fleksibilnu proizvodnju uvođenjem konfigurabilnih proizvodnih sistema i resursa koji odlikuju modularnost, interoperabilnost, skalabilnost i mogućnosti komunikacije. Trenutno se širom sveta istražuju različiti pristupi u nastojanju da se dostigne sledeći nivo proizvodnih tehnologija bez ugrožavanja same proizvodnje. Razmatrani pristupi podrazumevaju implementaciju Ciber Phisical Sistem-a, Interneta stvari i generacije proizvodnih sistema Digital Tvins. Složeni industrijski upravljački sistemi, koji su tradicionalno ožičeni i smatraju se sigurnim, sada postaju distribuirani, povezani na internet, obično se zasnivaju na bežičnoj komunikaciji i širom su otvoreni za sve vrste zlonamjernih podviga s potencijalno fatalnim posledicama. U ovom radu predstavljen je pregled bezbednosnih pitanja koja su ključna za razvoj sigurnije bežične distribucije kontrole proizvodnih resursa, pogodnih za izazove u narednim vremenima.Industry 4.0 paradigm dictates highly efficient and flexible production through introduction of reconfigurable manufacturing systems and resources characterized by modularity, interoperability, scalability and communication capabilities. Various approaches are currently researched worldwide in an effort to achieve the next level of production technologies without compromising the production itself. Considered approaches imply implementation of Cyber Physical Systems, Internet of Things and generation of manufacturing systems Digital Twins. Complex industrial control systems, which were traditionally wired and considered safe, are now becoming distributed, internet-connected, usually based on wireless communication and wide open for all kinds of malicious exploits with potentially fatal consequences. This paper presents a review of security related issues that are crucial in developing safer wireless distributed control of manufacturing resources, ADEPT for challenges in coming times

Distributed control of manufacturing resources: Security related issues

Paradigma industrije 4.0 diktira visoko efikasnu i fleksibilnu proizvodnju uvođenjem konfigurabilnih proizvodnih sistema i resursa koji odlikuju modularnost, interoperabilnost, skalabilnost i mogućnosti komunikacije. Trenutno se širom sveta istražuju različiti pristupi u nastojanju da se dostigne sledeći nivo proizvodnih tehnologija bez ugrožavanja same proizvodnje. Razmatrani pristupi podrazumevaju implementaciju Ciber Phisical Sistem-a, Interneta stvari i generacije proizvodnih sistema Digital Tvins. Složeni industrijski upravljački sistemi, koji su tradicionalno ožičeni i smatraju se sigurnim, sada postaju distribuirani, povezani na internet, obično se zasnivaju na bežičnoj komunikaciji i širom su otvoreni za sve vrste zlonamjernih podviga s potencijalno fatalnim posledicama. U ovom radu predstavljen je pregled bezbednosnih pitanja koja su ključna za razvoj sigurnije bežične distribucije kontrole proizvodnih resursa, pogodnih za izazove u narednim vremenima.Industry 4.0 paradigm dictates highly efficient and flexible production through introduction of reconfigurable manufacturing systems and resources characterized by modularity, interoperability, scalability and communication capabilities. Various approaches are currently researched worldwide in an effort to achieve the next level of production technologies without compromising the production itself. Considered approaches imply implementation of Cyber Physical Systems, Internet of Things and generation of manufacturing systems Digital Twins. Complex industrial control systems, which were traditionally wired and considered safe, are now becoming distributed, internet-connected, usually based on wireless communication and wide open for all kinds of malicious exploits with potentially fatal consequences. This paper presents a review of security related issues that are crucial in developing safer wireless distributed control of manufacturing resources, ADEPT for challenges in coming times

Hardened properties of 3D printed concrete - experimental investigation

At the end of the last century, 3D printing of concrete became an innovative method for producing concrete structures. The beginning of the application of 3D printing in the concrete construction industry is referred to the Contour Crafting printing method. In addition to Contour Crafting, other methods such as Fused Deposition Modeling, Shotcrete 3D Printing, and ink printing method, developed and utilized by D-Shape, have been applied in this field. Through the use of these technologies, numerous structures have been successfully created, including one-story and multi-story houses, residential buildings, pedestrian bridges, as well as individual elements like columns, walls, facade panels and outdoor furniture. However, the wider implementation of this technology has revealed various challenges, such as the lack of regulations and standards for the production and testing of these concrete materials as well as the structural analysis of 3D printed structures. The topic of this research is the investigation of the hardened properties of 3D printed concrete. The focus is on the physical and mechanical properties such as the bulk density of concrete, compressive strength, flexural strength and interlayer bond strength. This paper gives an overview of previous research on these properties, while the experimental part gives insight into the results of own research. Two types of specimen processing were used: full-notch removal (series 1) and printed samples (series 2). Additionally, samples with four or six layers were analyzed. The obtained values for bulk density were 1964.46 kg/m³ for full-notch removal samples and 1859.62 kg/m³ for printed samples. The compressive strength was 25 MPa for perpendicular and lateral directions, while the bending strength was 5.57 MPa. A significant influence of layering on fracture patterns and results was observed during the bond strength testing. The obtained values ranged from 1.59 to 2.91 MPa, the lowest value was obtained in the axial tension test, while the highest value was achieved in the shear test. The highest uniformity of results was achieved for series 1 samples tested in axial tension and splitting tests

Projektovanje mostova prema zahtevima životne sredine

Zaštita životne sredine nesumnjivo postaje primarni zadatak čovečanstva u 21. veku. Razvoj tehnologije i tehnike doneo je mnoge lagodnosti ljudima, ali istovremeno je negativno uticao na njihovu okolinu. U okviru ovoga rada predstavljen je uticaj mostovskih konstrukcija na životnu sredinu. Pregledom literature, utvrđeni su određeni negativni efekti kroz različite faze projekta, od izvođenja do sanacija konstrukcija mostova. Pokazani su rezultati primene koncepta Ocene životnog ciklusa (Life Cycle Assessment - LCA) u projektovanju mostova na određenim primerima. Studijom slučaja je prikazana mogućnost upotrebe integralnih mostova u smanjenju zagađenja životne sredine. U zaključnim razmatranjima, predstavljen je model uvođenja zahteva životne sredine u proces projektovanja i izvođenja

Distribuirano upravljanje pneumatskim robotom bazirano na IEC 61499 i 802.15.4 standardima

Potrebe današnjeg tržišta nameću primenu i razvoj novih tehnologija koje omogućavaju efikasno generisanje malih proizvodnih serija uz ekstremno brzu reakciju prilikom pojave zahteva za novim proizvodima. Proizvodnja mora biti fleksibilna, sa proizvodnim sredstvima koja poseduju rekonfigurabilnu hardversku i softversku strukturu. Decentralizacijom upravljanja i distribucijom upravljačkih zadataka na više inteligentnih uređaja pojednostavljuje se konfigurisanje i rekonfigurisanje automatskih proizvodnih sistema, čime se mogu ostvariti značajne uštede u energiji, materijalu i vremenu. U okviru ovog rada opisan je distribuirani sistem upravljanja pneumatskim robotom za bojenje, zasnovan na standardu IEC 61499, uz upotrebu IEC 802.15.4 bežičnog komunikacionog protokola

Primena distribuiranog sistema upravljanja baziranog na IEC 61499 i 802.15.4 standardima

Savremene proizvodne sisteme karakteriše potreba za kratkim odzivom na nove tržišne zahteve, uz vrhunski kvalitet proizvoda i maksimalnu efikasnost. Tako visok tehnološki nivo dostiže se primenom fleksibilnih tehnologija, čiji su osnov proizvodna sredstva sa rekonfigurabilnom hardverskom i softverskom strukturom. Distribuirano upravljanje podržava opisani pristup proizvodnji kroz decentralizovano izvršavanje upravljačkog zadatka na više inteligentnih (pametnih) uređaja. Uz adekvatnu primenu, distribuirano upravljanje može dovesti do značajnih ušteda energije, materijala i vremena. U okviru ovog rada opisan je distribuirani sistem upravljanja pneumatskim robotom zasnovan na standardu IEC 61499, uz upotrebu komunikacije bazirane na standardu IEC 802.15.4

Uporedna analiza betonskog integralnog nadputnjaka pri različitim karakteristikama tla

U okviru rada razmatran je betonski integralni nadputnjak raspona 30 metara na magistralnom putu koji je fundiran na šipovima. Analiziran je uticaj krutosti tla na vrednosti statičkih uticaja merodavnih za dimenzionisanje elemenata konstrukcije nadputnjaka i vrednost napona u šipovima konstrukcije. Korišćena su tri slučaja tla čija krutost je određena shodno karakteristikama slojeva. Za potrebe analize korišćen je numerički model nadputnjaka napravljen u softverskom paketu CSiBridge v20 gde je tlo modelirano u formi "opruga" (fleksibilnih oslonaca) postavljenih po visini šipa čija krutost odgovara krutosti sloja tla kroz koji prolazi šip

Procedure for definition of end-effector orientation in planar surfaces robot applications

Razvoj moćnih metoda za programiranje robota koje su ujedno i korisnički prilagođene je tema značajnih istraživanja u robotskoj zajednici. Radi olakšavanja programiranja robota, pojavljuje se ideja o razvoju standardnih procedura za programiranje najčešće prisutnih robotskih zadataka, a koje se mogu univerzalno lako upotrebiti kao gotov deo (ready-made) korisničkog programa. Važna klasa aplikacija industrijskih robota podrazumeva kretanje hvatača (end-effector) u paralelnim ravnima. U ovom radu je prikazan razvoj procedure jezika za programiranje robota koja služi za određivanje normale ravni objekta u odnosu na koordinatni sistem od značaja, kao i osnova procedure za automatizovani postupak programiranja orijentacije hvatača u odnosu na ravan objekta. Ova procedura se može koristiti kao integralni deo task oriented metoda programiranja robota, a takođe kao i procedura eksplicitnog robotskog programskog jezika, i ilustrovana je kroz praktični primer na robotu Lola 15.Design of user-friendly and at the same time powerful robot programming methods is the subject of significant efforts undertaken by the international robotics community. For the purpose of facilitating robot programming, with regard to the most common present-day applications in industry, it would be useful to develop programming procedures for frequently used manipulator tasks which could be easily implemented and used as ready-made application software. Important class of industrial robot applications involves end-effector trajectories in planar surfaces. Development of robot programming language procedure intended for determination of object plane normal with respect to frame of interest, as well as programming of end-effector orientation is presented in this paper. This procedure can be used as integral part of task oriented robot programing applications as well as a procedure for explicit programming languages, and it is illustrated in practical example with the robot Lola 15