A Study on Determination of Optimum Partial Transmission Ratios of Mechanical Driven Systems Using a Chain Drive and a Three-Step Helical Reducer

Author(s):  
Nguyen Thi Hong Cam ◽  
Vu Ngoc Pi ◽  
Nguyen Khac Tuan ◽  
Le Xuan Hung ◽  
Tran Thi Phuong Thao
Keyword(s):  
Author(s):  
Petro D. Kryvyy ◽  
Ihor M. Bey ◽  
Oksana I. Shymanska ◽  
Petro P. Kryvyy

Abstract The analysis of the available calculation methods of chain-drives load-carrying ability is given according to the criterion of the tolerance unit pressure in a single profile chain joint [p]0. It is shown, that the values of [p]0 were determined according to the deterministic ideas without consideration of the distribution law of both random varieties of contact step of inner and outer rings and lengths of drive strands of the first and second profile of the chain drive. Probability task of determination of the tolerance unit pressure in two profile chain joints [p0]q is solved, when the structural, technological and physical-mechanical characteristic of the chain, that is, the lengths of drive strand of a chain-drive, accuracy of contact steps and stiffness of a drive roller chain are considered. The measurement procedure and the empirical dependencies for determination of drive roller chains deformation and stiffness are presented. As a result, the dependencies for the determination of [p0]q as the basic criterion according to which selection of a chain dimension-type, as well as characteristics used for the comparative estimation of a drive chain quality of different manufacturers when certain probability estimations are taken into consideration, were obtained.


1979 ◽  
Author(s):  
Daniel Walz ◽  
Thomas Brown

Human prothrombin activation is unique in that, in addition to the release of fragment 1.2 (FI.2) from the NH-terminus of prothrombin by factor Xa during the generation of thrombin, an additional 13 residue polypeptide, fragment 3 (F3), is autocatalytically removed from the amino-terminus of the thrombin A chain. We have developed a rapid radioimmunoassay for human F3 which incorporates short incubation times and the use of a preprecipitated second antibody; the assay can be performed in three hours. Specificity studies in buffer systems show prothrombin and prethrombin 1 cross-reacting at a level of 0.001; purified thrombin does not cross-react. In the presence of 5% BSA, prothrombin displays considerably less cross-reactivity. No immunoreactive material to F3 antibodies could be detected in 400 μL of plasma. Serum, obtained from whole blood clotting, contained measurable quantities of F3 (40-100 ng/mL). This amount in serum represents only 5-10% of the theoretical amount available should all of the fragment be hydrolytically cleaved during the conversion of prothrombin to thrombin. This assay procedure is currently being utilized to monitor the activation of purified human prothrombin in the absence and presence of selected plasma inhibitors. (Supported in part by NIH 05384-17 and the Michigan Heart Association).


Author(s):  
Shanzhong Duan ◽  
Kurt S. Anderson

Abstract The paper presents a new hybrid parallelizable low order algorithm for modeling the dynamic behavior of multi-rigid-body chain systems. The method is based on cutting certain system interbody joints so that largely independent multibody subchain systems are formed. These subchains interact with one another through associated unknown constraint forces f¯c at the cut joints. The increased parallelism is obtainable through cutting the joints and the explicit determination of associated constraint loads combined with a sequential O(n) procedure. In other words, sequential O(n) procedures are performed to form and solve equations of motion within subchains and parallel strategies are used to form and solve constraint equations between subchains in parallel. The algorithm can easily accommodate the available number of processors while maintaining high efficiency. An O[(n+m)Np+m(1+γ)Np+mγlog2Np](0<γ<1) performance will be achieved with Np processors for a chain system with n degrees of freedom and m constraints due to cutting of interbody joints.


2021 ◽  
Vol 4 (1) ◽  
pp. 29-35
Author(s):  
Nafisa Saidho’jaeva ◽  

The article deals with the calculation of the drive and chain transmission of the newly created mechanized drying plant for drying melon slices. The essence of the utility model: the machine contains a horizontal tunnel chamber, inside which is mounted a chain conveyor with driving and driven sprockets, load-carrying elements, the IR emitters with reflectors on top of the camera mounted electric air heater, fan, an annular heat exchanger equipped with inlet and outlet nozzles of the drying agent. On the branches of the conveyor chain, lodgments with folding clamps are mounted, on which load-bearing elements are fixed, which are used as wooden poles. The calculation of the drive and chain transmission of the drying plant conveyor was carried out according to the existing method according to the scheme shown in the figure. Thus, the main parameters of the drive and chain transmission parts of the mechanized chamber-chain drying plant for drying melon fruits were determined by calculation


2001 ◽  
Vol 14 (1-2) ◽  
pp. 39-84 ◽  
Author(s):  
Sonja Brentjes

This paper investigates the affiliation of Book I of the Latin translation of Euclid's Elements attributed to Hermann of Carinthia with the Arabic transmission of the Greek mathematical work. It argues that it is a translation of a text of the Arabic secondary transmission, that is, of an Arabic edition mixed with comments. Two methodological claims are made in the paper. The first insists that the determination of a text whose transmission was as multifaceted and complex as the Euclidean Elements needs to be based on a systematic investigation of entire books rather than on selected theorems or diagrams of global, mostly structural relevance. The second claim starts from the experience that almost all results regarding the place of a particular document in a chain of transmission are conjectural. It acknowledges that individual results are more or less persuasive, depending upon the qualitative status of the argument. It suggests that the quantitative accumulation of similarities, differences, errors, regularities, or peculiarities allows one to recognize patterns and thus improves the reliability of judgment.


2000 ◽  
Vol 55 (9) ◽  
pp. 773-784 ◽  
Author(s):  
Hans Bock ◽  
Erik Heigel ◽  
Norbert Nagel

Imidodiphosphates ⊖N[PO(OR)2]2 and Imidodiphosphonates ⊖N[POR2]2 are effective chelating ligands for a variety of metal cations including even Na⊕, for which a lipophilically wrapped hexameric polyion cluster has been structurally characterized. The corresponding hexameric lithium and polyrubidium ion complexes reported here exhibit considerable structural differences: The rather small Li⊕ cations of coordination number five and tetraphenylimidodiphosphate form an isolated hexameric aggregate analogous to the Na⊕ one, whereas the larger Rb⊕ with coordination number seven and (3,4-dimethylphenyl)substituents crystallizes as a chain polymer. Based on the crystal structures, the dominant Coulomb attractions between cations and anions, the spatial requirement of the ligands and the essential phenyl/phenyl interactions in their lipophilic skin are discussed


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