Determination of joint reactions in a rigid multibody system, two different approaches

U ovom radu su prikazane dve različite metode za određivanje sila i momenata reakcija idealnih veza u zglobovima. Razmatrani sistem više tela ima strukturu otvorenog kinematskog lanca. Prva metoda se odnosi na određivanje glavnih vektora i momenata reakcija veza u simboličkoj formi koja se zasniva na Rodrigezovom pristupu i pogodna je za simboličko računanje. Druga prikazana metoda je vektorska metoda koja je bazirana na vektorima momenata masa i vektorima rotatorima vezanih za pol i usmerenu osu. Oba primera su prikazana i diskutovana na sistemu tri kruta tela.In this paper two different methods for determination of frictionless joint reaction forces and moments are presented. The considered multibody system has an open kinematic chain structure. The first method refers to the determination of resultant joint reaction forces and moments based on the Rodrigues approach suitable for computation in a symbolic form. The second method presented is the method based on the so-called vectors of the body mass moments and vector rotators coupled for a pole and oriented axes. Both approaches are presented and discussed on the three- like rigid multibody system

Determination of joint reactions in a rigid multibody system, two different approaches

U ovom radu su prikazane dve različite metode za određivanje sila i momenata reakcija idealnih veza u zglobovima. Razmatrani sistem više tela ima strukturu otvorenog kinematskog lanca. Prva metoda se odnosi na određivanje glavnih vektora i momenata reakcija veza u simboličkoj formi koja se zasniva na Rodrigezovom pristupu i pogodna je za simboličko računanje. Druga prikazana metoda je vektorska metoda koja je bazirana na vektorima momenata masa i vektorima rotatorima vezanih za pol i usmerenu osu. Oba primera su prikazana i diskutovana na sistemu tri kruta tela.In this paper two different methods for determination of frictionless joint reaction forces and moments are presented. The considered multibody system has an open kinematic chain structure. The first method refers to the determination of resultant joint reaction forces and moments based on the Rodrigues approach suitable for computation in a symbolic form. The second method presented is the method based on the so-called vectors of the body mass moments and vector rotators coupled for a pole and oriented axes. Both approaches are presented and discussed on the three- like rigid multibody system

Standard industrial guideline for mechatronic product design

Danas, moderni proizvodi predstavljaju sveobuhvatne mehaničke sisteme sa kompletnom integrisanom elektronikom i informacionom tehnologijom (IT). Takvi proizvodi, koji se smatraju mehatroničkim proizvodima, zahtevaju drugi pristup za efikasan razvoj kao čisto mehanički, elektronski-električni ili IT proizvodi. Industrijski i naučni razvoj mehatroničkih proizvoda dovode do značajnog iskustva i kao prirodna posledica primene industrijskih uputstava pojavljuje se u projektovanju proizvoda kao što su mehatronički proizvodi. Široko prihvaćena industrijska uputstva predlažu važne korake i mere sa ciljem efikasnog finaliziranja i sa cenom prihvatljivih mehatroničkih proizvoda. Na kraju, pored prezentacije i komentara na predstavljena industrijska uputstva, ilustrovana je praktična primena na primeru veš mašina. .Modern products are comprehensive mechanical systems with fully integrated electronics and information technology (IT). Such products, which are considered mechatronic products, demand another approach for efficient development as pure mechanical, electronic/electric and IT products. Industrial and scientific evolutions of mechatronic products have led to substantial experience and as a natural consequence industrial guideline have emerged for the product design of mechatronic products. Widely accepted industrial guidelines proposed crucial steps and measures to finalize efficient and cost-efficient mechatronic products. Aside from the presentation of and comments on such industrial guidelines, some examples for practical application are also given - washing machines.

Standard industrial guideline for mechatronic product design

Danas, moderni proizvodi predstavljaju sveobuhvatne mehaničke sisteme sa kompletnom integrisanom elektronikom i informacionom tehnologijom (IT). Takvi proizvodi, koji se smatraju mehatroničkim proizvodima, zahtevaju drugi pristup za efikasan razvoj kao čisto mehanički, elektronski-električni ili IT proizvodi. Industrijski i naučni razvoj mehatroničkih proizvoda dovode do značajnog iskustva i kao prirodna posledica primene industrijskih uputstava pojavljuje se u projektovanju proizvoda kao što su mehatronički proizvodi. Široko prihvaćena industrijska uputstva predlažu važne korake i mere sa ciljem efikasnog finaliziranja i sa cenom prihvatljivih mehatroničkih proizvoda. Na kraju, pored prezentacije i komentara na predstavljena industrijska uputstva, ilustrovana je praktična primena na primeru veš mašina. .Modern products are comprehensive mechanical systems with fully integrated electronics and information technology (IT). Such products, which are considered mechatronic products, demand another approach for efficient development as pure mechanical, electronic/electric and IT products. Industrial and scientific evolutions of mechatronic products have led to substantial experience and as a natural consequence industrial guideline have emerged for the product design of mechatronic products. Widely accepted industrial guidelines proposed crucial steps and measures to finalize efficient and cost-efficient mechatronic products. Aside from the presentation of and comments on such industrial guidelines, some examples for practical application are also given - washing machines.

Genetic variation and correlations of life-history traits in gypsy moths (Lymantria dispar L.) from two populations in Serbia

Periodic fluctuations in density impose different selection pressures on populations of outbreaking Lepidoptera due to changes in their nutritional environment. The maternal effects hypothesis of insect outbreak predicts the transmission of this nutritional "information" to subsequent generations and alterations in offspring life-history traits. To test for these time-delayed effects of the parental generation, we compared life-history traits and their variation and covariation among laboratory-reared gypsy moths hatched from egg masses collected from low- and medium-density populations. Decreased individual performance was recorded in offspring from the medium-density population, indicating reduced egg provisioning under crowding conditions. Genetic variance and covariance were also shown to be sensitive to density of the parental generation. In gypsy moths from the medium-density population, quantitative genetic analysis revealed significantly higher broad-sense heritabilities for development duration traits and demonstrated a trade-off between development duration and body size

Uticaj polimorfizma Fokl gena za vitamin D receptor i TNFa-308 gena za faktor nekroze tumora na težinu i ishod bolesti kod dece sa juvenilnim idiopatskim artritisom

Оur main objective was to investigate possible influence of tumor necrosis factor alpha (TNF-α-308) and FokI Vitamin D receptor (VDR) gene polymorphism on long term disease outcome in JIA patients treated with biologics. We have retrospectively analyzed data from our registry of JIA patients treated with biologics in whom 6 years follow-up data could be obtained and genomic deoxyribonucleic acid (DNA) extracted to test TNF-α–308 promoter and FokI VDR polymorphism. Disease activity was evaluated by ACR Pedi core set criteria for inactive disease. Among 78 JIA patients was not significant distribution difference of TNF-α-308 and FokI VDR gene polymorphism among different JIA subtypes. Patients with -308 GG (p=0,004) and GA (p=0,026) genotype achieved clinical response significantly more frequently than those with the -308 AA genotype after 36 month of follow up period. Patients with FF (p=0,006) and Ff (p=0,036) genotypes had a reduction of disease activity and more frequently reached clinical response to biologics with respect to the ff genotype at the end of the observational period. There was no influence of distribution of the -308 TNF-α on achieving remission, but there was different distribution of FokI polymorphism on possibility to achieve remission at the end of the observational period. Patients resistant to biologics had significantly more frequent ff genotype, while those achieved remission had significantly more frequent Ff genotype (χ2=6,52, p=0,038). JIA patients carrying TNF-α-308 AA genotype and those with VDR ff genotype despite biological treatment, have lesser chance to achieve remission

The influence of modification methods on physico-chemical and sorption properties of sepiolite Umnoženo za odbranu.

Predmet ove doktorske disertacije je proučavanje uticaja modifikacije prirodnog sepiolita primenom soli N-[(3-trimetoksi)propil]etilendiamintriacetatne kiseline ((CH3O)3Si(CH2)3N(CH2COONa)N(CH2)2N(CH2COONa)2), [3-(2- aminoetilamino)propil]trimetoksisilana ((CH3O)3Si(CH2)3NH(CH2)2NH2)), 3- merkaptopropiltrimetoksisilana (HS(CH2)3Si(OCH3)3) i gvožñe(III)-hlorida u baznoj sredini na fizičko-hemijska svojstva sepiolita, kao i na sorpciju Cu2+, Co2+ i Ni2+ jona iz vodenih rastvora i sorpciju organskih jedinjenja iz gasovite faze. Karakteristično svojstvo površine, tačka nultog naelektrisanja, pHtnn, odreñena je u rastvoru elektrolita različite koncentracije, kao i u prisustvu jona Cu2+, Co2+ i Ni2+. Utvrñeno je da se tačka nultog naelektrisanja ne menja sa promenom koncentracije rastvora KNO3, dok se u prisustvu Cu2+, Co2+ i Ni2+ jona pomera ka nižim pH vrednostima, što ukazuje na specifčnu sorpciju jona. Postupak modifikacije prirodnog sepiolita merkapto-silanom i amino-silanom nije doveo do povećanja sorpcije jona. Uzorak modifikovan oksidom gvožña pokazao se kao efikasan sorbent u sorpciji Cu2+, Co2+ i Ni2+ jona, dok je u slučaju modifikacije vodenim rastvorom natrijumove soli N-[(3-trimetoksi)propil]etilendiamintriacetatne kiseline uočen porast sorpcionog kapaciteta za Ni2+ jone. Sorpcija jona Cu2+, Co2+ i Ni2+ iz vodenog rastvora rezultat je istovremenog odigravanja procesa jonske izmene sa Mg2+ jonima iz sepiolitske strukture i specifične sorpcije. Poreñenjem maksimalnih sorpcionih kapaciteta utvrñeno je kod svih ispitanih sorbenata najveća sorpcija Cu2+ jona, zatim Co2+ jona a najmanja sorpcija Ni2+ jona. Proces sorpcije ispitanih jona na prirodnom, kao i na modifikovanim sepiolitima najbolje se opisuje Langmuir-ovom izotermom. Promena pH vrednosti, u oblasti u kojoj ne dolazi do rastvaranja sorbenta i hidrolize jona, nije bitno uticala na količinu sorbovanih jona na prirodnom sepiolitu, kao ni na modifikovanim uzorcima. Sorpcija jona Cu2+, Co2+ i Ni2+ jona raste sa porastom temperature. Pozitivne vrednosti promene entalpije sorpcije pokazuju da je sorpcija endoterman proces. Ispitivanje kinetike sorpcije, pri istoj polaznoj koncentraciji jona metala pokazalo je da kinetički model pseudo-drugog reda najbolje opisuje eksperimentalne rezultate, za sve ispitane sorbente. Vrednosti konstanti jonizacije uzorka sepiolita modifikovanog gvožñe(III)- hloridom u baznoj sredini (Fe-SEP) iznose: p 1 int a K = 6,7 ± 0,1 i p 2 int a K = 10,2 ± 0,1. Uzorak ima veću relativnu kiselost površinskih funkcionalnih grupa u odnosu na prirodni sepiolit, usled prisustva gvožñe(III)-oksihidroksida u strukturi modifikovanog sepiolita. Primenom inverzne gasne hromatografije u uslovima nulte prekrivenosti u temperaturnom opsegu 483-513 K izračunate su vrednosti osnovnih termodinamičkih parametara adsorpcije (slobodne površinske energije, standardne entalpije i standardne entropije adsorpcije) na uzorku Fe-SEP, kao i specifična i disperzivna komponenta slobodne energije adsorpcije. Rezultati ispitivanja interakcija uzorka Fe-SEP i kiselih, baznih i amfoternih organskih molekula pokazali su da je površina ispitanog uzorka baznog karaktera. Na osnovu dobijenih adsorpcionih izotermi za n-heksan, benzen, hloroform i tetrahidrofuran na sepiolitu Fe-SEP primenom inverzne gasne hromatografije u uslovima konačne prekrivenosti u temperaturnom opsegu 483-513 K i B.E.T. jednačine izračunate su vrednosti specifične površine, izosterične toplote adsorpcije, kao i raspodela adsorpcione energije. Površina sepiolita pokazuje povećani afinitet prema hloroformu usled uspostavljanja jakih kiselo-baznih interakcija.The aim of this study was to investigate the influence of modification of natural sepiolite using: 3-mercaptopropyltrimethoxysilane (HS(CH2)3Si(OCH3)3), [3-(2- aminoethylamino)propyl]trimethoxysilane ((CH3O)3Si(CH2)3NH(CH2)2NH2)), N-[3- (trimethoxysilyl)propyl], ethylenediamine triacetic acid trisodium salt ((CH3O)3Si(CH2)3N(CH2COONa)N(CH2)2N(CH2COONa)2) and iron(III)chloride in basic conditions, on physico-chemical properties, sorption of Cu2+, Co2+ and Ni2+ ions from water solutions and sorption of organic molecules from the gas phase. The point of zero charge, pHtnn, as an important surface parameter, was determined in electrolyte solutions with different initial concentration and in the solution of M2+ ions. The value of pHtnn remains constant with changing concentration of the KNO3 solution. The shift of the point of zero charge of sepiolite samples was determined in the presence of Cu2+, Co2+ and Ni2+ ions indicating that specific sorption of M2+ ions onto sepiolite samples had occurred. The improvement of the sorption efficiency of samples obtained by modification of sepiolite with mercapto-silane and amino-silane was not observed. Modification of natural sepiolite by iron oxyhydroxide resulted in formation of an effective sorbent for sorption of Cu2+, Co2+ and Ni2+ ions, while in the case of modification by ethylenediamine triacetic acid trisodium salt from water solution, the increase of sorption capacity was deteced for sorption of Ni2+ ions. The sorption of Cu2+, Co2+ and Ni2+ ions from water solutions is the result of the process of ion exchange of Mg2+ ions from the sepiolite structure and specific sorption. According to maximal sorption capacities, the sorption was the highest in the case of Cu2+ ions, then Co2+, and the lowest in case of Ni2+ ions, for used all sorbent. The equilibrium sorption process, for all investigated ions, on natural, as well as on modified samples, was well described by the Langmuir isotherm model. The change of the initial pH value, in the pH range where sorbent dissolution and hydrolysis of ions can be excluded, did not affect the change of capacities of sorption, on natural, as well on modified samples. The quantity of sorbed Cu2+, Co2+ and Ni2+ ions increased with increasing temperature. The positive enthalpy change indicates that the process of removal of M2+ ions from water solution by sepiolites was endothermic. The sorption kinetic study showed that pseudo-second order was the model that best described the experimental sorption data for all investigated ions and all the sorbents used, indicating that the sorption may be controlled by chemical sorption. The ionization constants of the surface functional groups of sepiolite modified with iron(III)chloride in basic conditions (Fe-SEP) determined from the potentiometric titration data, were p int a1 K = 6.7 ± 0.1 and p int a2 K = 10.2 ± 0.1. The relative acidity of the surface functional groups was lower comparing to natural sepiolite sample, that can be assigned to the presence of iron oxyhydroxide particles at the surface of modified material. The thermodynamic parameters (free energy, enthalpy, entropy) of adsorption as well as dispersive and specific components of free energy of adsorption were calculated from the inverse gas chromatography measurements for the probes on the sample Fe- SEP in temperature range 483-513K. The results of interactions of Fe-SEP amd bacis, acid and amphoteric organic probes indicate that Fe-SEP surface has basic character. The sorption isotherms for n-hexane, benzene, chloroform and tetrahydrofurane, on sample Fe-SEP, determined by inverse gas chromatography at finite concentration condition in the temperature range 483-513 K, were used to estimate the surface area, isosteric heat of adsorption and adsorption energy distribution function. The strong interaction between Fe-SEP surface and chloroform, due to acid-base interactions, was established

Ectomycorrhiza of coniferous tree species in Montenegro with special attention to mycorrhiza of Pinus heldreihii Christ

Mikoriza predstavlja zajednicu između grupe gljiva koje žive u zemljištu i korena viših biljaka. Mikoriza se javlja u svim terestričnim ekosistemima i ima važnu ulogu u usvajanju hranljivih materija. Osim toga, biljke sa mikorizom su otpornije na bolesti i sušu. Ekrtomikoriza je tip mikorizne simbioze karakterističan za drveće iz familija Betulaceae, Pinaceae, Fagaceae i Salicaceae, koje predstavlja ekološki i ekonomski najznačajnije drvenaste vrste, dominantne u borealnim, mediteranskim šumama i šumama umerenog pojasa. Analiza diverziteta i rasprostranjenja ektomikorize je značajna za razumevanje njene ekološke uloge. Na osnovu objavljenih podataka, dosadašnjim istraživanjima je u Crnoj Gori zabeleženo 48 rodova ektomikoriznih gljiva: 12 rodova Ascomycota (50 taksona) i 38 rodova Basidiomycota (267 taksona), što predstavlja oko trećinu makromiceta zabeleženih u Crnoj Gori. Munika (Pinus heldrechii Christ.), tercijalni relikt i subendemit, predstavlja jedan od najinteresantnijih elemenata dendroflore Balkana. Zajednice gljiva u šumama munike su slabo istražene, dok ektomikorizne zajednice munike nisu do sada opisivane, niti potvrđene. Zbog svoje ekološke plastičnosti munika se može koristiti za pošumljavanje ekstremnih terena. U tom smislu pažnju zavređuju i ektomikorizne gljive koje opstaju baš na ovakvim staništima. Cilj ove doktorske disetacije bio je upoznavanje sa ektomikoriznim zajednicama munike, kao i ispitivanje mogućnosti primene i korišćenja autohtonih ektomikoriznih gljiva u rasadničkoj proizvodnji četinara. Formirana je kolekcija koja je sadržala oko 40 kultura pretpostavljeno ektomikoriznih gljiva sa prostora Crne Gore, koje su korišćene u daljim istraživanjima. Upotrebom različitih metoda inokulacije u laboratorijskim uslovima ostvarena je ektomikoriza između munike i 18 vrsta gljiva...Mycorrhizas are symbiotic associations formed between the group of specialized soil fungi and roots of higher plants. Mycorrhizas are present in all terrestrial ecosystems and play a central role in the nutrient uptake. In addition, mycorrhizal plants are often more resistant to diseases caused by microbial soil borne pathogens and to the effects of drought. Ectomycorhiza is being established with roots of trees, especially the families Betulaceae, Pinaceae, Fagaceae and Salicaceae, representing ecologically and economically most important tree species being dominated in boreal, Mediterranean forests and forests in temperate region. Analysis of diversity and distribution of ectomyccorhizas is important for understanding of their ecological function. According to published data, 50 ectomycorrhizal fungal genera have been recorded in Montenegro until now: 12 Genera of Ascomycota (50 taxa) and 38 Genera of Basidiomicota (267 taxa), representing c.ca one third of the total number of macromycetes’ records here. Pinus heldrechii Christ, being tertiar relict and subendemic, is one of the most interesting elements of Balkan’s dendroflorae. Fungal communities in P. heldreichii forests are only slightly examined, while their ectomycorrhizal communities have not been described or even confirmed. Due to evident ecological adaptibility, P. heldreichii could be used for afforestation of extreme terrains. In that sense, ectomycorrhizal fungi surviving on these soils should receive a special scientific attention. The overall aim of this doctorial dissertation was to introduce the ectomycorrhizal communities of Pinus heldreichii, also as to examine the possibilities of application of ectomycorrhizal fungi in nurrsery production of conifers. The collection of c.ca 40 of fungal culture’s isolates of putative ectomycorrhizal fungi from Montenegro area was established and used in further researches..

Fractal boundary value problems for integral and differential equations with local fractional operators

In the present paper we investigate the fractal boundary value problems for the Fredholm and Volterra integral equations, heat conduction and wave equations by using the local fractional decomposition method. The operator is described by the local fractional operators. The four illustrative examples are given to elaborate the accuracy and reliability of the obtained results

Fractal boundary value problems for integral and differential equations with local fractional operators

In the present paper we investigate the fractal boundary value problems for the Fredholm and Volterra integral equations, heat conduction and wave equations by using the local fractional decomposition method. The operator is described by the local fractional operators. The four illustrative examples are given to elaborate the accuracy and reliability of the obtained results