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

Uticaj sistema za vantelesni krvotok na sistemski inflamatorni odgovor i funkciju trombocita kod pacijenata koji se podvrgavaju revaskularizaciji miokarda

Although surgical revascularization of the myocardium is routine and one of the most performed procedures in cardiac surgery, complications that occur during and after surgery, such as systemic inflammation and sepsis, as well as bleeding due to impaired platelet function, have a high share in such high mortality. The extracorporeal bloodstream system has a special role in these processes. Determination of levels of new biomarker for detection infectious complications - presepsin, with CRP and leukocyte formula, is just one of these diagnostic combinations of tests that allow assessment of the immune status of a cardiac patient and the need for further examination and / or therapy of patients who may potentially develop systemic inflammatory response syndrome (SIRS) or sepsis. On the other hand, the application of aggregometry gives precise data on the functional changes of platelets, which enables adequate care of complications in terms of increased postoperative bleeding or thrombosis. The study included 100 patients of both sexes, 22 women (21.6%) and 78 men (76.5%), mean age 64.63 ± 7.48 years. Patients were divided into two groups in relation to the use of extracorporeal blood circulation device. Postoperatively, there was a decrease in the number of erythrocytes (p <0.001), hemoglobin (p <0.001), hematocrit (p <0.001), platelet count (p <0.001), ADP HS (p <0.001) and ASPI (p <0.05)test), and increases in the number of leukocytes (p <0.001) and the concentration of CRP (p <0.001) and presepsin (p <0.001 in the group of patients with ECC, with statistical significance of p <0.001 for all measured variables.The average perioperative blood loss was 1250 (1100.0-1700.0) ml, and there was no statistically significant difference between patients with and without EKK (Z = 1,653, p = 0,098) Serious bleeding (> 1800ml) was present in 15 patients (15 in the group where the extracorporeal circulatory system was applied, 17.64% of patients (9/51) met the clinical criteria for SIRS with elevated presepsin values of 600 pg / ml and more, while in the second group of patients 2 of 49 (4.08%) met the clinical and laboratory criteria for SIRS.The ECC system significantly affects the development of SIRS and inhibition of platelet function in patients where it was applied during surgery

Mineral Nutrition of Two Potato Cultivars Diff ering in Aluminium Tolerance, as Affected by Liming and Soil Acidity

Acid soil is one of the most important limitations in agricultural production worldwide. The application of lime and the growth of Al-tolerant genotypes are the most commonly employed strategies for the amelioration of acidic soil constraints. This study evaluates the effect of soil acidity and liming on the growth and mineral nutrition of Al-tolerant potato cv. Tresor and Al-sensitive potato cv. Canberra (Solanum tuberosum L.). Liming increased the total shoot and root dry matter (DM) of cv. Canberra, and the leaf DM of cv. Tresor. ‘Tresor’ retained a greater ability to acquire nutrients from acidic soil, especially P, Ca, and Mg. In addition, the Al content in the root tips and in other vegetative parts of acidic soil-grown plants indicates, on one hand, the complexity of acidic soil toxicity that was not solely related to Al toxicity and, on the other, the possible involvement of multiple mechanisms of Al tolerance that could be partly related to better nutrient uptake from acidic soil

Adaptronika in dinamika pralnega stroja

V želji po trajnostnem razvoju si v industrijskih podjetjih prizadevajo dosegati zelo lahke konstrukcije proizvoda s kar najmanjšim vplivom na okolje. Dober primer so pralni stroji, pri katerih je obvladovanje vibracij in hrupa kot stranski in neželeni učinek zelo pomembna naloga pri razvoju konkurenčnega proizvoda. Zato se tudi v industriji bele tehnike uporabljajo dognanja s področja adaptronike in adaptronskih sistemov, ki so sicer večinoma domena avtomobilske in letalske industrije. Prispevek prikazuje praktičen primer uporabe magnetnoreoloških dušilcev za analizo in razvoj dinamike pralnega stroja pri doseganju želenih funkcionalnih lastnosti. V dinamiki sistemov je tak tehnični sistem dušenja poznan kot sistem delno aktivnega ali adaptivnega obvladovanja (kontrole) vibracij. Opisane so tudi možnosti uporabnosti adaptronskih sistemov pri drugih elementih in komponentah pralnega stroja.COBISS.SI-ID 6531225

Cauchy-Schwarz and Grüss-Landau inequalities for elementary operators and inner product type transformers on Q and Q* ideals of compact operators

Неједнакости Коши-Шварца и Грис-Ландауа за елементарне операторе и трансформере типа унутрашњег производа на Q и Q∗ идеалима компактних оператора Резиме: Листа од раније познатих и недавно установљених Cauchy-Schwarz-ових неједнакости за елементарне операторе, σ−елементарне трансформере и трансформере типа унутрашњег производа допуњена је следећом варијантом Cauchy-Schwarz-ове неједнакости у Schatten-von Neumann-овим идеалима: ZΩ AtA∗ t dµ(t) 12q − 1Z2 Ω AtXBt dµ(t)ZΩ Bt∗Bt dµ(t) 1 2r − 12 p 6 ZΩ A∗ t At dµ(t) 12q XZΩ BtBt∗ dµ(t) 1 2r p за све X 2 C p(H) и све p, q, r > 1 такве да је 2 p = 1q + 1r, уколико су фамилије оператора fAtgt∈Ω, fA∗ tgt∈Ω, fBtgt∈Ω, fBt∗gt∈Ω јако квадратно интеграбилне, такве да су RΩ AtA∗ t dµ(t) и RΩ Bt∗Bt dµ(t) (ограничено) инвертибилни оператори. Разматраће се такође и друге варијанте оваквих неједнакости, омогућене додатним условима комутативности и нормалности операторних фамилија fAng∞ n=1, fBng∞ n=1, fAtgt∈Ω и fBtgt∈Ω, односно степеном p-модификације унитарно инваријантних норми, као и примене ових неједнакости на одређене проблеме у теорији оператора, укључујући норма неједнакости за генерализоване функцијске деривације Pick-ових оператор вредносних функција и оператор вредносних Fourier-ових трансформација комплексних мера, као и неједнакости Grüss-Landau-овог типа.List of already known and recently established Cauchy-Schwarz inequalities for elementary operators, σ−elementary transformers and inner product type transformers is complemented by the next variant of Cauchy-Schwarz inequality in Schatten-von Neumann ideals: ZΩ AtA∗ t dµ(t) 12q − 1Z2 Ω AtXBt dµ(t)ZΩ Bt∗Bt dµ(t) 1 2r − 12 p 6 ZΩ A∗ t At dµ(t) 12q XZΩ BtBt∗ dµ(t) 1 2r p for all X 2 C p(H) and for all p, q, r > 1 which satisfes 2 p = 1q + 1r, if families of operators fAtgt∈Ω, fA∗ tgt∈Ω, fBtgt∈Ω, fBt∗gt∈Ω are strongly square integrabile, such that RΩ AtA∗ t dµ(t) and RΩ Bt∗Bt dµ(t) are (boundedly) invertible operators. Enabled by some additional conditions of commutativity and normality for operator families fAng∞ n=1, fBng∞ n=1, fAtgt∈Ω and fBtgt∈Ω, as well as by the degree of p-modifcations of unitary invariant norms, some others variants of those inequalities will also be considered, including their applications to the certain problems in operator theory, norm inequalities for generalized function derivations of Pick operator values functions and operator values Fourier transformations of complex measures, as well as some Grüss-Landau type inequalities

Fiziologija bilja

Fiziologija bilja egzaktna je znanost koja proučava životne procese u biljkama, od klijanja sjemena, vegetativnog rasta i razvoja, cvatnje, stvaranja plodova i sjemena do starenja i ugibanja. Fiziologija bilja izravno je povezana sa svakom biljnom proizvodnjom te je poznavanje fizioloških procesa u biljci temelj svake agronomske struke. Ovaj je priručnik namijenjen studentima preddiplomskih studija Agronomskog fakulteta, kao temeljna literatura za polaganje ispita iz modula Fiziologija bilja, ali i za sve studente koji se žele upoznati s osnovama funkcioniranja biljnog organizma

Equations of Motion of Robotic System With Piezo‐Modified Viscoelastic and Magnetorheological Elements of Fractional Order

In this communication, the Rodriguez method is proposed for modeling dynamics of the robotic system, where Lagrange’s equations of second kind of rigid bodies system in covariant form are used. Discrete hybrid elements with so called piezomodified Kelvin-Voight (PKV) and magnetorheological (MRD) type of viscoelastic models with fractional order derivatives are introduced in to the system of motion equations by means of generalized forces. The results obtained are illustrated by numerical examples

Equations of Motion of Robotic System With Piezo‐Modified Viscoelastic and Magnetorheological Elements of Fractional Order

In this communication, the Rodriguez method is proposed for modeling dynamics of the robotic system, where Lagrange’s equations of second kind of rigid bodies system in covariant form are used. Discrete hybrid elements with so called piezomodified Kelvin-Voight (PKV) and magnetorheological (MRD) type of viscoelastic models with fractional order derivatives are introduced in to the system of motion equations by means of generalized forces. The results obtained are illustrated by numerical examples

Generalized Forces of the Robotic System with Fractional Order Thermoviscoelastic Element

In this paper, we analyze generalized forces of a discrete fractional order Kelvin-Voigt thermoviscoelasic element connected into a multibody robotic system. An efficient numerical approximation scheme is used to approximate fractional order derivative. The effects of fractional order derivative and temperature change on generalized forces are examined through the numerical example of simple three rigid body robotic syste