Part Accuracy Management by Topological Mapping of Deviations

2016 ◽  
Vol 859 ◽  
pp. 210-216
Author(s):  
Gabriel Frumuşanu ◽  
Alexandru Epureanu
Keyword(s):  
Geometrical Model ◽  
Synthetic Approach ◽  
Concrete Case ◽  
Topological Map ◽  
New Approach ◽  
Part Geometry ◽  
Real Geometry ◽  
Geometric Deviations ◽  
New Type ◽  
Modern Manufacturing

Despite modern manufacturing processes are characterized by a continuously increasing accuracy, geometric deviations inherently appear on every manufactured part so, for quality-aware companies, it is essential to control and to manage them. This paper introduces a new type of part geometrical model, namely the part topological map, in connection with a new approach in part accuracy management. The part topological map enables a global analytical & synthetic approach of the problems related to tolerancing domain and a generalization of the “part accuracy” concept. The part geometry is seen as a stand-alone ensemble of surfaces dimensionally related, unitary and with its own shape, dimensions and position. The real geometry has also a global, unitary deviation, characterized through deviation features. Each component surface is represented in a particular manner, unrolled, while its deviation features are assessed by using series expansion of the deviations corresponding to a cloud of measured points. A method for effectively realizing the topological map of a part deviation and a numerical exercise to illustrate the method application in a concrete case are also included.

Click Reactions in Chemistry of Triterpenes - Advances Towards Development of Potential Therapeutics

2018 ◽  
Vol 25 (5) ◽  
pp. 636-658 ◽  
Author(s):  
Jan Pokorny ◽  
Lucie Borkova ◽  
Milan Urban
Keyword(s):  
Biological Activities ◽  
Synthetic Approach ◽  
Clinical Use ◽  
New Approach ◽  
Click Reactions ◽  
Drug Candidates ◽  
The Past ◽  
Low Toxicity ◽  
New Compounds ◽  
Potential Therapeutics

Triterpenoids are natural compounds with a large variety of biological activities such as anticancer, antiviral, antibacterial, antifungal, antiparazitic, antiinflammatory and others. Despite their low toxicity and simple availability from the natural resources, their clinical use is still severely limited by their higher IC50 and worse pharmacological properties than in the currently used therapeutics. This fact encouraged a number of researchers to develop new terpenic derivatives more suitable for the potential clinical use. This review summarizes a new approach to improve both, the activity and ADME-Tox properties by connecting active terpenes to another modifying molecules using click reactions. Within the past few years, this synthetic approach was well explored yielding a lot of great improvements of the parent compounds along with some less successful attempts. A large quantity of the new compounds presented here are superior in both activity and ADME-Tox properties to their parents. This review should serve the researchers who need to promote their hit triterpenic structures towards their clinical use and it is intended as a guide for the chemical synthesis of better drug candidates.

scholarly journals Cryogenic Exfoliation of 2D Stanene Nanosheets for Cancer Theranostics

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Jiang Ouyang ◽  
Ling Zhang ◽  
Leijiao Li ◽  
Wei Chen ◽  
Zhongmin Tang ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Density Functional ◽  
Biomedical Application ◽  
Density Functional Theory Calculations ◽  
Free Electrons ◽  
Functional Theory ◽  
New Approach ◽  
New Type ◽  
Average Size ◽  
Cancer Theranostics

Abstract Stanene (Sn)-based materials have been extensively applied in industrial production and daily life, but their potential biomedical application remains largely unexplored, which is due to the absence of the appropriate and effective methods for fabricating Sn-based biomaterials. Herein, we explored a new approach combining cryogenic exfoliation and liquid-phase exfoliation to successfully manufacture two-dimensional (2D) Sn nanosheets (SnNSs). The obtained SnNSs exhibited a typical sheet-like structure with an average size of ~ 100 nm and a thickness of ~ 5.1 nm. After PEGylation, the resulting PEGylated SnNSs (SnNSs@PEG) exhibited good stability, superior biocompatibility, and excellent photothermal performance, which could serve as robust photothermal agents for multi-modal imaging (fluorescence/photoacoustic/photothermal imaging)-guided photothermal elimination of cancer. Furthermore, we also used first-principles density functional theory calculations to investigate the photothermal mechanism of SnNSs, revealing that the free electrons in upper and lower layers of SnNSs contribute to the conversion of the photo to thermal. This work not only introduces a new approach to fabricate 2D SnNSs but also establishes the SnNSs-based nanomedicines for photonic cancer theranostics. This new type of SnNSs with great potential in the field of nanomedicines may spur a wave of developing Sn-based biological materials to benefit biomedical applications.

scholarly journals Scientia est potentia

2009 ◽  
pp. 43-60
Author(s):  
Ülo Kaevats
Keyword(s):  
Modern Science ◽  
New Approach ◽  
Natural Laws ◽  
Modern Times ◽  
Natural Objects ◽  
Deductive Method ◽  
New Type ◽  
The Subject ◽  
Understanding Of Science ◽  
Object Of Study

Oma algses mitmetähenduslikkuses on see F. Baconi aforism kõige tihendatum tõdemus, mis tõmbab olemusliku eraldusjoone ühelt poolt antiikse ja keskaegse ning teisalt uusaegse arusaama vahele teadusest ja teadusteadmisest. Artiklis püüab autor anda võimaluste piires tervikpildi uusaja teaduse industriaalselt (tehnoloogiliselt) orienteeritud teadmistüübi tekkimisest. Uusaja teaduse kujunemiseks vajaliku pöörde maailmavaateliste eeldustena tuleb käsitleda: (1) põhimõtteliselt uut subjekti ja objekti käsitust; (2) täiesti uut väärtusruumi, uut teaduse ideoloogiat (ilmalikkus, kriitiline vaim, tõesus ja praktiline kasulikkus); (3) tunnetuslaadi muutust — kontemplatsioonilt interventsioonile, kvaliteedi kirjeldamiselt kvantiteedi uurimisele; (4) looduse käsitlemist Kosmose asemel seaduspäraselt korrastatud objektide “väljana”. Uue tunnetusstiili — empiirilise ja teoreetilise tunnetuse kokkuviimine, hüpoteetilis-deduktiivse metodoloogia kujundamine Galilei poolt, abstraktse ja sünteetilis-tekstilise loomuga spekulatsiooni asendumine uurimisobjekti ehituse, korrapära ja põhjuslikkuse objektiivse analüüsiga, universaalsete loodusseaduste doktriini kujunemine jms—kujunemine konstitueeris uut tüüpi teadmise. Teadmise kui nähtava maailma piltkoopia asemele luuakse teadmine kui loodusobjektide seaduspära analüütiline rekonstruktsioon. See on vormiltmatemaatiline, päritolult eksperimentaalne ning loodusobjektide kontrollimisele ja ümbertegemisele suunatud nn valdamisteadmine.This F. Bacon's aphorism in its original ambiguity is the most condensed belief that draws a distinctive essential line between ancient and medieval understanding of science and scientific knowledge on one hand and modern understanding on the other. The author aims at providing, as far as possible, an integral overview of emerging of the industrially (technologically) orientated type of knowledge of modern times. Ideological/philosophical preconditions of the change necessary for emerging of modern science are: (1) a fundamentally new approach to the subject and object; (2) a completely new system of values, a new ideology of science (secularity, critical spirit, trueness and utilitarianism); (3) a change in manner of cognizance - from contemplation to intervention, from describing quality to studying quantity; (4) treating nature as a naturally organised "field" of objects instead of the Cosmos. Emerging of a new style of cognizance - bringing together of empirical and theoretical cognition, the devise of the hypothetical-deductive method by Galilei, replacement of speculations abstract and synthetic-textual in nature with objective study of the structure, regularity and causality of the object of study, establishment of the doctrine of universal natural laws etc - constituted a new type of knowledge. Knowledge as a copy of the visible world is replaced by knowledge as an analytical reconstruction of the regularity of natural objects. It is so-called dispositive knowledge, morphologically mathematical, originally experimental and aimed at control and alteration of natural objects.

scholarly journals AILU FOR HELMHOLTZ PROBLEMS: A NEW PRECONDITIONER BASED ON THE ANALYTIC PARABOLIC FACTORIZATION

2001 ◽  
Vol 09 (04) ◽  
pp. 1499-1506 ◽  
Author(s):  
MARTIN J. GANDER ◽  
FRÉDÉRIC NATAF
Keyword(s):  
Numerical Experiments ◽  
New Approach ◽  
New Type

We investigate a new type of preconditioner which is based on the analytic factorization of the operator into two parabolic factors. Approximate analytic factorizations lead to new block ILU preconditioners. We analyze the preconditioner at the continuous level where it is possible to optimize its performance. Numerical experiments illustrate the effectiveness of the new approach.

scholarly journals Constructive basis for the development of the extreme zones of Siberia and the Russian arctic

2018 ◽  
Vol 7 (2.13) ◽  
pp. 75
Author(s):  
Tat'yana Sarvut
Keyword(s):  
Structural Changes ◽  
Irreversible Process ◽  
World Ocean ◽  
Weather Conditions ◽  
Russian Arctic ◽  
Protective Measures ◽  
New Approach ◽  
The World ◽  
The Face ◽  
New Type

The paper describes the constructive basis for building and structure designing in the difficult regions of Siberia and the Russian Arctic and development of a new approach to the design of buildings and structures in the Russian Arctic in the face of climate change. Severe climate and weather conditions of the northwestern territories of Russia are rapidly changing due to the global warming. The structural changes in development and construction, following this irreversible process, are highlighted and discussed in relation to the foundations and constructive systems. The paper provides an overview of methods and technological approaches to the extreme zone construction. The application of modern methods of design and construction with the involvement of competent "practitioners" increases the pace of construction and reduces its cost; Architectural and constructive solutions should focus on the developing areas of business and tourism. We suggest the possible protective measures against the transgression of the World Ocean and thawing of the permafrost. The term “special Arctic bases”, denoting the new type of settlements in the Russian Arctic, is introduced. The introduction of constructive solutions and the development of planning solutions for the bases will help to ensure a stable activity in the region.  

Nonlinear Dynamic Response of a Thin Plate in a Fractional Viscoelastic Medium under Internal Resonance 1:1:2

2014 ◽  
Vol 518 ◽  
pp. 60-65 ◽  
Author(s):  
Yury Rossikhin ◽  
Marina Shitikova
Keyword(s):  
Nonlinear Equations ◽  
Time Scales ◽  
Viscoelastic Medium ◽  
Equations Of Motion ◽  
Multiple Time Scales ◽  
Multiple Time ◽  
Internal Resonances ◽  
Nonlinear Dynamic Response ◽  
New Approach ◽  
New Type

Dynamic behaviour of a nonlinear plate embedded in a fractional derivative viscoelastic medium and subjected to the conditions of the internal resonances two-to-one has been studied by Rossikhin and Shitikova in [1]. Nonlinear equations, the linear parts of which occur to be coupled, were solved by the method of multiple time scales. A new approach proposed in this paper allows one to uncouple the linear parts of equations of motion of the plate, while the same method, the method of multiple time scales, has been utilized for solving nonlinear equations. The new approach enables one to find a new type of the internal resonanse, i.e., one-to-one-to-two, as well as to solve the problems of vibrations of thin bodies more efficiently.

Error Minimization in Layered Manufacturing Parts by Stereolithography File Modification Using a Vertex Translation Algorithm

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Gaurav Navangul ◽  
Ratnadeep Paul ◽  
Sam Anand
Keyword(s):  
Layered Manufacturing ◽  
Conversion Error ◽  
File Size ◽  
Profile Error ◽  
Multiple Points ◽  
New Approach ◽  
Stl File ◽  
Part Geometry ◽  
Translation Error ◽  
Part Surface

Layered manufacturing (LM) machines use stereolithography (STL) files to build parts by creating continuous slices on top of each other. An STL file approximates the surface of a part with planar triangles. This results in geometric errors being introduced in the part surface during the conversion from the CAD model to the STL file format, which in turn leads to errors in the LM manufactured part. CAD packages have built-in export options to reduce this CAD to STL conversion error. However, this is applied to the entire part geometry which leads to an increase in the file size and preprocessing time in LM machines. This paper presents a new approach to locally reduce this CAD to STL translation error. This approach, referred to as vertex translation algorithm (VTA), compares an STL facet to its corresponding CAD surface, computes the chordal error at multiple points on the STL surface, and translates the point with the maximum chordal error until it lies on the design surface. This translation results in the reduction of the chordal error locally without unnecessarily increasing the size of the STL file. In addition, a facet isolation algorithm (FIA) has also been developed and presented in this paper. This isolation algorithm extracts the STL facets corresponding to the surfaces and features of the part that have to be modified by the translation algorithm. The VTA is applied in conjunction with the FIA on a sample service part to reduce the form and profile error of critical features of the part in order to satisfy the tolerance callouts on the part.

scholarly journals Land classification based on hydrological landscape units

2011 ◽  
Vol 8 (3) ◽  
pp. 4381-4425
Author(s):  
S. Gharari ◽  
F. Fenicia ◽  
M. Hrachowitz ◽  
H. H. G. Savenije
Keyword(s):  
Conceptual Models ◽  
Overland Flow ◽  
Surface Flow ◽  
Landscape Classification ◽  
Surface Slope ◽  
New Approach ◽  
Digital Elevation ◽  
New Type ◽  
Elevation Model ◽  
Landscape Units

Abstract. This paper presents a new type of hydrological landscape classification based on dominant runoff mechanisms. Three landscape classes are distinguished: wetland, hillslope and plateau, corresponding to three dominant hydrological regimes: saturation excess overland flow, storage excess sub-surface flow, and deep percolation. Topography, geology and land use hold the key to identifying these landscapes. The height above the nearest drain (HAND) and the surface slope, which can be readily obtained from a digital elevation model, appear to be the dominant topographical parameters for hydrological classification. In this paper several indicators for classification are tested as well as their sensitivity to scale and sample size. It appears that the best results are obtained by the simple use of HAND and slope. The results obtained compare well with field observations and the topographical wetness index. The new approach appears to be an efficient method to "read the landscape" on the basis of which conceptual models can be developed.

scholarly journals G˚arding Cones and Bellman Equations in the Theory of Hessian Operators and Equations

2017 ◽  
Vol 63 (4) ◽  
pp. 615-626
Author(s):  
N M Ivochkina ◽  
N V Filimonenkova
Keyword(s):  
Partial Differential Equations ◽  
Differential Operators ◽  
Comparison Theorems ◽  
Symmetric Matrices ◽  
New Approach ◽  
Bellman Equations ◽  
Nonlinear Differential Operators ◽  
Algebraic Properties ◽  
New Type ◽  
Continue Investigation

In this work, we continue investigation of algebraic properties of G˚arding cones in the space of symmetric matrices. Based on this theory, we propose a new approach to study of fully nonlinear differential operators and second-order partial differential equations. We prove new-type comparison theorems for evolution Hessian operators and establish a relation between Hessian and Bellman equations.

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