Developing a Model for Sustainable Conversion of Blockhouse Bunkers in Serbia

Blockhouses represent a type of small-span aboveground bunkers, originally built in England but later also in other parts of the world. These specific forms of military heritage, which were largely built during the WWII in Balkan, are forgotten witnesses of the past. As the old military concepts and doctrines have been abandoned, the strategic interest for the blockhouses has been lost, while the questions about their future arose. While the developed countries are actively engaged in the search for sustainable solutions that consider finding the non-military uses for these military structures, it is still quite a rarity in Serbia. Many blockhouses are located in the areas of outstanding natural values or within the urban zones; so consequently, they do have a potential to be integrated into contemporary urban dynamics. The paper examines reasons and possibilities for the reuse of blockhouse bunkers, taking into account the principles of sustainability and the indicators for adaptability, analysing their spatial, functional transformation through the development of a model for sustainable conversion. In order to check the debated postulates, a design proposal of a blockhouse converted into a single-family house is presented and discussed from the aspect of layout flexibility and development of a modular extension, as a plausible and sustainable scenario

Primena CAD/CAM tehnologije u projektovanju i izradi mostova pune anatomske forme na bazi cirkonijum-dioksida

Daily progress of dentistry, especially in the field of prosthodontics is introducing new materials and technologies. With the increasing need for aesthetically acceptable and non-metal materials, it came to development and improvement of ceramic materials and computer based systems (CA). The patient came in order to compensate the missing left lateral incisor. Since the adjacent teeth are brushed and the print was taken, casted model has been scanned using 3Shape D800 laboratory scanner. Dental restoration has been designed using 3Shape DentalSystem Premium software and the available tools. After completing the virtual design, the data are sent to the program responsible for CAM Zenotec® mini CAD/CAM device. As a result, the compensation with the full morphology was obtained without the need for finishing works.Stomatologija, posebno stomatološka protetika svakodnevno napreduje uvođenjem novih materijala i tehnologija. Kako se javlja sve veća potreba za estetski prihvatljivim i bezmetalnim materijalima, došlo je do razvoja i unapređenja keramičkih materijala i računarima podržanih sistema (CA). Pacijent se javio radi nadoknade nedostajućeg levog bočnog sekutića. Pošto su susedni zubi zbrušeni i uzet otisak, izliven je model koji je skeniran pomoću 3Shape D 800 laboratorijskog skenera. Zubna nadoknada je dizajnirana pomo ću 3Shape DentalSystem Premium softvera korišćenjem raspoloživih alata. Nakon završenog dizajna virtuelni podaci su poslati u program odgovoran za CAM Zenotec® mini CAD/CAM uređaja. Kao rezultat, dobijena je nadoknada pune morfologije bez potrebe za dorađivanjem

Challenges of the Integration of Micromobility Vehicles into Modern Traffic and Transportation Systems

This paper presents the main challenges of integrating micromobility vehicles into modern traffic and transportation systems. Although micromobility seems to be an effective concept for the first and last mile, the reality points to the potential problems that the integration of micromobility vehicles can create and that must be resolved appropriately. Micromobility vehicles are characterised by extensive development, which is not accompanied by appropriate legal regulations. The street design has its spatial limitations and usually separates non-motorised and motorised users, which is a notion that could be disrupted by new micromobility options. When it comes to Serbia, the existing legislation does not recognise the majority of micromobility vehicles, which results in the lack of safety of these participants and their place in the street profile. The aim of this paper is to provide guidelines for improving the existing regulations and integrating these vehicles into the traffic system of Serbia, with special reference to general recommendations through which micromobility vehicles can be treated in other countries. The results of this paper can be useful to decision-makers but also to all other participants in the process of developing effective policies and strategies for the integration of micromobility vehicles into traffic and transportation systems

Re-CAD/CAM pristup projektovanju i izradi zubnih keramičkih navlaka u kombinaciji sa ručnim individualnim prilagođavanjem

CAD/CAM technology in dentistry offers high-end ceramic restorations, known for its quality, preciseness, swiftness and repeatability. However, some features are still human-dependent. A young female patient required smile enhancement, since suffering from colour change on three devitalized frontal teeth. After fiber post placement, teeth were prepared for metal-free restoration. Consequently, abutments were scanned using extraoral scanner (Sirona, InEos Blue; Beinsheim, Germany). CAD software (version 3.8) has been used to create three crown copings, with cut-back in the incisal region. After finalization of the virtual modeling, data file has been transferred to a milling unit (Sirona, MCXL, Beinsheim, Germany) that produced crown copings out of a ceramic block (IPS e.max CAD, Ivoclar Vivadent, Schaan, Liechtestein). Crowns were tried for the fit and occlusion in the so-called blue stage, after which final strength and shape has been achieved by thermal treatment in the ceramic furnace. Individualization has been done manually, creating special effect in the cut-back region. Crowns were cemented adhesively. CAD/CAM offers modern and relevant way of producing ceramic restorations, however, special effects still require manual adjustments.CAD/CAM tehnologije u stomatologiji nude visoko kvalitetne keramičke zamene, poznate po kvalitetu, preciznosti, brzini izrade i ponovljivosti. Međutim neke opcije još uvek zavise od ljudske intervencije. Mlada pacijentkinja je imala zahtev za poboljšanjem osmeha, pošto je patila od promene boje na tri prednja nezdrava zuba. Posle instalacije vlaknene podloge, zubi su bili spremni za bez-metalnu reparaciju. Otisci su bili skenirani ekstraoralnim skenerom (Sirona, InEos Blue, Beinsheim, Nemačka). CAD softver (verzija 3.8) je korišćen za generisanje tri navlake. Po završetku virtuelnog modeliranja podaci su prebačeni na glodalicu (Sirona, MCXL, Beinsheim, Nemačka) koja je izradila navlake od keramičkih blokova (IPS-a, max CAD, Ivoclar Vivadent, Schaan, Lihtenštajn). Navlake su posle isprobane zbog procene naleganja i začepljenja u tzv. plavoj etapi, posle čega je konačno očvršćavanje i oblikovanje postignuto termičkom obradom u peći za keramiku. Individualno prilagođavanje je izvršeno ručno, sa izradom posebnog efekta u zadnjem delu. Navlake su cementirane adhezijom. CAD/CAM nudi moderan i važan način u izradi keramičkih implanta ali posebni efekti još uvek zahtevaju intervenciju čoveka

In vitro procena citotoksičnosti 3D štampanog polimera na bazi epoksi smole namenjenog za upotrebu u stomatologiji

Background/Aim. There is limited published evidence on the cytotoxicity of 3D printed polymer materials for dentistry applications, despite that they are now widely used in medicine. Stereolithography (SLA) is one of the foremost 3D processes used in 3D printing, yet there are only a small number of resin materials reported to be suitable for medical applications. The aim of this study was to investigate, in vitro, the cytotoxic effect of the 3D printed resin in order to establish the suitability for its usage in dentistry and related medical applications such as surgical dental guides, occlusal splits and orthodontic devices. Methods. To examine the cytotoxicity of the 3D printed polymer-based epoxy resin, Accura® ClearVue™ (3D-Systems, USA), two cell cultures were used: mouse fibroblasts L929, and human lung fibroblasts MRC-5. The cell viability was determined by the Mosmann's colorimetric (MTT) test and the agar diffusion test (ADT). Results. Direct contact of the tested material with the ADT test showed nontoxic effects of tested material in any cell culture. The tested material showed no cytotoxic effect after 3 days of extraction of the eluate by the MTT, but mild cytotoxic effect after 5, 7 and 21 days on both cell lines. The cytotoxicity increased with increasing the time of the eluate extraction. Conclusion. The 3D printed polymer-based epoxy resin, Accura® ClearVue™ (3D-Systems, USA) is considered appropriate for making surgical dental implant guides according to the cytotoxic behavior. According to the mild level of cytotoxicity after the longer extraction periods, there is a need for further evaluation of biocompatibility for its application for the occlusal splints and orthodontic devices.Uvod/Cilj. Malo je objavljenih dokaza o citotoksičnosti 3D štampanih polimernih materijala za upotrebu u stomatologiji, bez obzira na njihovu sve širu primenu u medicini. Stereolitografija (SLA) jedan je od najvažnijih 3D procesa koji se primenjuje za 3D štampu, ali postoji samo Mali broj materijala na bazi smola za koje je dokazano da su pogodni za medicinsku primenu. Cilj ove studije je bio da se ispita, in vitro, citotoksični efekat 3D štampanog polimera kako bi se utvrdila mogućnost za njegovu upotrebu u stomatologiji i srodnim medicinskim oblastima, kao što su hirurške dentalne vođice, okluzalni splintovi i ortodontski aparati. Metode. Da bi se ispitala citotoksičnost 3D štampanog polimera na bazi epoksi smole, Accura® ClearVue ™ (3D-Sistems, USA), korišc'ene su dve c'elijske kulture: fibroblasti miša L929 i humani fibroplasti pluc'a MRC-5. Vijabilnost c'elija utvrđena je Mosmannovim kolorimetrijskim testom (MTT) i testom difuzije agara (ADT). Rezultati. Direktan kontakt testiranog materijala ispitan pomoću ADT pokazao je da materijal nije imao citotoksičan efekat ni na jednu ćelijsku kulturu. Testitrani materijal je imao blag citotoksični efekat posle 5, 7 i 21 dana ekstrakcije eluata primenom MTT na obe ćelijske linije. Citotoksičnost je rasla sa produženjem vremena ekstrakcije eluata. Zaključak. 3D štampani polimer na bazi epoksi smole, Accura® ClearVue ™ (3D-Sistems, USA) se može smatrati pogodnim za izradu hirurških dentalnih implantnih vođica sa tačke gledišta njegovog citotoksičnog uticaja. Zbog pokazanih blagih citotoksičnih efekata nakon dužih ekstrakcionih perioda eluata potrebna su dalja istraživanja u oblasti biokompatibilnosti materijala da bi se taj polimer mogao koristiti za izradu okluzalnih splintova i ortodontskih aparata

Utvrđivanje korozionih karakteristika stomatološke legure sa induktivno spregnutim plazma masenim spektrometrom

Corrosion resistance is one of the characteristics that dental alloy should possess as it should be placed in the oral cavity. Adverse tissue reactions of the gingiva and the periodontium close to dental cast alloys may be caused by the effects of released metal elements. Corrosion effect of dental Co-Cr-Mo alloy was investigated by ICP MS according to the EN ISO 10271 and EN ISO 22674. Co- Cr dental alloy Remanium GM 800+ (Dentaurum Ispringen, Germany was tested in artificial saliva for 7 days at 37ºC. The released metals were detected by Nexion 300X ICP MS (Perkin Elmer, USA). The results showed that the metal release was very low for Co, Cr and Mo, far below the permitted levels. ICP-MS can be considered as very reliable method for such a research.Otpornost na koroziju je jedna od karakteristika koju poseduju stomatološke legure koje trebaju biti postavljene u usnoj duplji. Neželjene reakcije tkiva gingive i parodoncijuma sa stomatološkim legurama može biti uzrokovano efektima oslobođenih metalnih elemenata. Efekat korozije stomatološke Co- Cr -Mo legure ispitana je ICP MS prema EN ISO 10271 i EN ISO 22674 . Co- Cr stomatološke legure Remanium GM 800 + ( Dentaurum Ispringen , testirano u Nemačkoj u veštačkoj pljuvački tokom 7 dana na 37º C. Otkriveni su oslobođeni metali Nekion 300Ks ICP MS ( Perkin Elmer , SAD ). Rezultati su pokazali veoma slabo oslobađanje metala, Cr i Mo , daleko ispod dozvoljenih nivoa. ICP -MS može smatrati veoma pouzdan metod za ovakvo istraživanje

Toxic, Oviposition Deterrent and Oxidative Stress Effects of Thymus vulgaris Essential Oil against Acanthoscelides obtectus

Simple Summary Compounds of botanical origin, including essential oils (EOs), which coevolved as plant defense mechanism against herbivores and pathogens have been proposed as a promising strategy for post-harvest control of stored product insects. Despite several drawbacks, such as low stability, phytotoxicity and food odor changes at high concentrations, EOs are believed to be safe for human and environmental health and thus have an advantage comparing to conventional insecticides. The present study was aimed to examine acute toxicity and effects of thyme (Thymus vulgaris) EO on longevity, behavior and physiology of the bean weevil (Acanthoscelides obtectus), a major pest of stored bean seeds. We found that exposure to thyme oil reduced adult survival and longevity and induced damages to lipids and proteins in a concentration-dependent manner. Sublethal EO concentrations also deterred female egg laying and strongly inhibited adult emergence. Efficacy of such low EO concentrations in suppression of adult emergence implies that thyme EO might be cost-effective and environmentally low risk botanical insecticide for bean seed protection against A. obtectus. The bean weevil Acanthoscelides obtectus Say (Coleoptera: Chrysomelidae: Bruchinae) can cause significant losses in production of its primary host common bean Phaseolus vulgaris L. To avoid bean protection with environmentally risky chemical insecticides and provide sustainable and safe production of food, new pest management methods based on natural compounds are investigated. In the present study, we evaluated protective potential of the essential oil (EO) from the common thyme Thymus vulgaris L. applied on bean seeds. We assessed residual contact toxicity of thyme EO and its effects on A. obtectus longevity, oviposition and adult emergence. Furthermore, to elucidate the role of oxidative stress in thyme EO toxicity, we estimated the levels of oxidatively damaged proteins and lipids, as well as the level of thiols which have important role for antioxidant capacity. We found that thyme oil significantly reduced adult survival and longevity, induced oxidative damage to lipids and proteins and depleted protein and non-protein thiols in a concentration-dependent manner. Females appeared to be more tolerant to thyme oil treatment than males. Sublethal EO concentrations affected oxidative stress indices, deterred oviposition and strongly inhibited adult emergence. The results suggest that thyme oil has the potential to be used as an ecofriendly insecticide for A. obtectus control

Analysis of accuracy and precision of optical 3D digitisation devices in dental computer-aided-design and computer-aided-manufacturing systems

The implementation of intraoral and extraoral computer-aided-design and computer-aided-manufacturing (CAD/CAM) systems in prosthetic dentistry has simplified the procedure, shortened the period of design and manufacture and improved accuracy and aesthetic properties of dental restorations. Three-dimensional (3D) digitisation has become an adequate replacement for conventional dental impressions. The market offers a variety of diverse optical intraoral and extraoral CAD/CAM systems equipped with digitisation devices that are based on different working principles. The main goal of this research is to determine whether precision and accuracy differ among optical digitisation devices. The research includes five high-end devices: Cerec AC, Cerec InEos, Trios, KaVo Everest and Sinergia Scan. The evaluation methodology of the experiment is based on CAD inspection. The results, obtained from accuracy and precision measurements with tolerance levels of 0.01, 0.25 and 0.05 mm, indicate that there is a difference in accuracy and precision between optical digitisation devices based on different working principles

IN VIVO STUDY OF THE NANOMECHANICAL PROPERTIES OF LEUCITE GLASS CERAMIC PREPARED WITH DIFFERENT SURFACE FINISHING PROCEDURES

This paper reports the nanomechanical properties of Leucite glass ceramic prepared with three different surface finishing procedures: polishing, glazing and grinding, using the Nanoindenter. Also, AFM analysis was done in order to determine the roughness parameter Ra. The nanoindentation were performed in order to define the hardness (HV) and Young's modulus (E) of the surface structure using Berkovich diamond pyramid and the experiment was organized in a 3x4 array. Indentation imprints were investigated using the optical and Atomic Force Microscopy. The obtained results of nanomechanical properties mostly depend of applied surface finishing procedures.Publishe

Kupusnjače u pokrovnim usevima

In addition to true cereals (Poaceae) and legumes (Fabaceae), which are most commonly used as cover crops, plant species from the mustard family (Brassicaceae) are increasingly used due to their biological and agronomic characteristics. Crucifers grow fast, develop high biomass, achieve great land coverage ( gt 80%) and possess high nutrient uptake. These are the reasons that their use as cover crops has a beneficial effect on soil fertility, erosion prevention, weed suppression and groundwater quality protection. Majority of crucifers contain glucosinolates, the enzymatic conversion of which releases biologically active compounds into the soil, which are toxic to soil pathogens, nematodes and some weeds. In this way, crucifers act as soil biofumigants, and this effect is used in the control of harmful organisms within the cover crops technology. Due to different production systems and agroecological conditions, the release of these compounds in the soil is not constant, so the efficiency is not always the same. In this regard, biofumigation as a biological measure should be seen as a part of an integrated pest management strategy. With its flowers, crucifers attract a large number of insects: pollinators, predators and parasitoids, thus positively affecting the biodiversity of beneficial insects and the biocontrol of harmful ones. The most commonly used multipurpose cover crops are: rapeseed (Brassica napus L.), white mustard (Sinapis alba L.), brown mustard (Brassica juncea (L.) Czern.), charcoal turnip (Brassica rapa rapifera), fodder radish (Raphanus sativus L.), oil radish (Raphanus sativus var. oleifera) and others.Osim pravih žita (Poaceae) i leptirnjača (Fabaceae) koje se najčešće koriste u pokrovnim usevima, zbog svojih bioloških i agronomskih osobina sve više se koriste biljne vrste iz porodice kupusnjača (Brassicaceae). Kupusnjače brzo rastu, imaju veliku produkciju biomase, ostvaruju veliku pokrivenost zemljišta (>80%), a usvajanju i velike količine hranljivih materija. Zbog svega toga, primenom u pokrovnim usevima, povoljno utiču na plodnost zemljišta, sprečavaju njegovu eroziju, guše korove i štite kvalitet podzemnih voda. Većina kupusnjača sadrži glukozinolate, čijom enzimskom konverzijom se u zemljištu oslobađaju biološki aktivna jedinjenja, koja su toksična za zemljišne patogene, nematode i neke korove. Time kupusnjače u zemljištu deluju kao biofumiganti, a ovaj efekat u okviru tehnologije pokrovnih useva koristi se u kontroli štetnih organizama. Zbog različitih sistema proizvodnje i agroekoloških uslova, oslobađanje tih jedinjenja u zemljištu nije konstantno, pa efikasnost nije uvek ista. U tom smislu biofumigaciju kao biološku meru, treba posmatrati kao deo integrisanog pristupa kontrole štetnih organizama. Svojim cvetovima biljne vrste kupusnjača privlače veliki broj insekata: polinatora, predatora i parazitoida, pa tako pozitivno utičući na biodiverzitet korisnih insekata i biokontrolu štetnih. U pokrovnim usevima za različite namene najčešće se koriste: uljana repica (Brassica napus L.), bela slačica (Sinapis alba L.), smeđa slačica (Brassica juncea (L.) Czern.), repa ugarnjača (Brassica rapa rapifera), stočna rotkva (Raphanus sativus L.), uljana rotkva (Raphanus sativus var. oleifera) i druge