The Mechanics of Ideal Forming

1994 ◽  
Vol 61 (1) ◽  
pp. 176-181 ◽  
Author(s):  
K. Chung ◽  
O. Richmond
Keyword(s):  
Process Design ◽  
Three Dimensional ◽  
Field Equations ◽  
Starting Point ◽  
Deformation Processes ◽  
External Forces ◽  
Minimum Work ◽  
Yield Conditions ◽  
The Ideal

In this paper, the mechanics of ideal forming theory are summarized for general, three-dimensional, nonsteady processes. This theory has been developed for the initial stages of designing deformation processes. The objectives is to directly determine configurations, both initial and intermediate, that are required to ideally form a specified final shape. In the proposed theory, material elements are prescribed to deform along minimum plastic work paths, assuming that the materials have optimum formabilities in such paths. Then, the ideal forming processes are obtained so as to have the most uniform strain distributions in final products without shear tractions. As solutions, the theory provides the evolution of intermediate shapes of products and external forces as well as optimum strain distributions. Since the requirement of ideal forming to follow minimum work paths involves an over determination of the field equations, the theory places constraints on constitutive and boundary conditions. For example, tool interfaces must be frictionless and yield conditions must have vertices to achieve self-equilibrating three-dimensional deformations in most cases. Despite these constraints, the theory is believed to provide a useful starting point for deformation process design.

Theoretical determination of the structures of CaSiO3 perovskites

2006 ◽  
Vol 62 (6) ◽  
pp. 1025-1030 ◽  
Author(s):  
Razvan Caracas ◽  
Renata M. Wentzcovitch
Keyword(s):  
Crystal Structure ◽  
Experimental Data ◽  
Density Functional Theory ◽  
Density Functional ◽  
Theoretical Determination ◽  
Functional Theory ◽  
Starting Point ◽  
Atomic Coordinates ◽  
The Ideal

Density functional theory is used to determine the possible crystal structure of the CaSiO3 perovskites and their evolution under pressure. The ideal cubic perovskite is considered as a starting point for studying several possible lower-symmetry distorted structures. The theoretical lattice parameters and the atomic coordinates for all the structures are determined, and the results are discussed with respect to experimental data.

scholarly journals Structure of human dual-specificity phosphatase 7, a potential cancer drug target

2015 ◽  
Vol 71 (6) ◽  
pp. 650-656 ◽  
Author(s):  
George T. Lountos ◽  
Brian P. Austin ◽  
Joseph E. Tropea ◽  
David S. Waugh
Keyword(s):  
Catalytic Domain ◽  
Three Dimensional ◽  
Mitogen Activated Protein Kinase ◽  
Cancer Drug ◽  
Dual Specificity Phosphatase ◽  
Dual Specificity ◽  
Starting Point ◽  
Mitogen Activated Protein ◽  
Dual Specificity Phosphatases

Human dual-specificity phosphatase 7 (DUSP7/Pyst2) is a 320-residue protein that belongs to the mitogen-activated protein kinase phosphatase (MKP) subfamily of dual-specificity phosphatases. Although its precise biological function is still not fully understood, previous reports have demonstrated that DUSP7 is overexpressed in myeloid leukemia and other malignancies. Therefore, there is interest in developing DUSP7 inhibitors as potential therapeutic agents, especially for cancer. Here, the purification, crystallization and structure determination of the catalytic domain of DUSP7 (Ser141–Ser289/C232S) at 1.67 Å resolution are reported. The structure described here provides a starting point for structure-assisted inhibitor-design efforts and adds to the growing knowledge base of three-dimensional structures of the dual-specificity phosphatase family.

scholarly journals The Development of a Repetition-Load Scheme for the Eccentric- Only Bench Press Exercise

2013 ◽  
Vol 38 ◽  
pp. 23-31 ◽  
Author(s):  
Gavin L. Moir ◽  
Kyle F. Erny ◽  
Shala E. Davis ◽  
John J. Guers ◽  
Chad A. Witmer
Keyword(s):  
Linear Function ◽  
Bench Press ◽  
Three Dimensional ◽  
Load Condition ◽  
Vertical Force ◽  
Starting Point ◽  
Stretch Shortening Cycle ◽  
Analysis System ◽  
Repetitions To Failure

Abstract The purpose of the present study was to develop a repetition-load scheme for the eccentric-only bench press exercise. Nine resistance trained men (age: 21.6 ± 1.0 years; 1-repetition maximum [RM] bench press: 137.7 ± 30.4 kg) attended four testing sessions during a four week period. During the first session each subject’s 1-RM bench press load utilizing the stretch-shortening cycle was determined. During the remaining sessions they performed eccentric-only repetitions to failure using supra-maximal loads equivalent to 110%, 120% and 130% of their 1-RM value with a constant cadence (30 reps·min-1). Force plates and a three dimensional motion analysis system were used during these final three sessions in order to evaluate kinematic and kinetic variables. More repetitions were completed during the 110% 1-RM condition compared to the 130% 1-RM condition (p=0.01). Mean total work (p=0.046) as well as vertical force (p=0.049), vertical work (p=0.017), and vertical power output (p=0.05) were significantly greater during the 130% 1-RM condition compared to the 110% 1-RM condition. A linear function was fitted to the number of repetitions completed under each load condition that allowed the determination of the maximum number of repetitions that could be completed under other supra-maximal loads. This linear function predicted an eccentric-only 1-RM in the bench press with a load equivalent to 164.8% 1-RM, producing a load of 227.0 ± 50.0 kg. The repetition-load scheme presented here should provide a starting point for researchers to investigate the kinematic, kinetic and metabolic responses to eccentric-only bench press workouts.

Process Design of Laser Forming for Three-Dimensional Thin Plates

2004 ◽  
Vol 126 (2) ◽  
pp. 217-225 ◽  
Author(s):  
Jin Cheng ◽  
Y. Lawrence Yao
Keyword(s):  
Process Design ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Thin Plates ◽  
Laser Forming ◽  
Heat Condition ◽  
Bending Strain ◽  
Doubly Curved ◽  
Made In

Extensive efforts have been made in analyzing and predicting laser forming processes of sheet metal. Process design, on the other hand, is concerned with determination of laser scanning paths and laser heat condition given a desired shape. This paper presents an approach for process design of laser forming of thin plates with doubly curved shapes. The important feature of this method is that it first calculates the strain field required to form the shape. Scanning paths are decided based on the concept of in-plane strain, bending strain, principal minimal strain and temperature gradient mechanism of laser forming. Heating condition is determined by a lumped method. Effectiveness of the approach is numerically and experimentally validated through two different doubly curved shapes.

Buckling Delamination of the Rectangular Orthotropic Thick Plate With an Edge Rectangular Crack

2010 ◽  
Author(s):  
Surkay Akbarov ◽  
Nazmiye Yahnioglu ◽  
Esra Eylem Karatas
Keyword(s):  
Compressive Loading ◽  
Three Dimensional ◽  
Initial Imperfection ◽  
Critical Force ◽  
Geometrical Parameters ◽  
Field Equations ◽  
Rectangular Crack ◽  
Anisotropic Bodies ◽  
Buckling Delamination

The buckling delamination problem for the rectangular plate made from composite (orthotropic) material is studied. It is supposed that the plate has a rectangular edge-crack and edge-surfaces of that have an initial infinitesimal imperfection. The development of this initial imperfection with an external compressive loading acting along the crack is studied in the framework of the three-dimensional geometrically nonlinear field equations of the elasticity theory of anisotropic bodies. For the determination of the values of the critical force the initial imperfection criterion is used. The corresponding boundary-value problems are solved by employing the boundary form perturbation techniques and the FEM. The influence of the material or geometrical parameters of the plate on the values of critical force is discussed.

The comparison of the westernization process in ottoman and Russian empires

2016 ◽  
Author(s):  
Melih Cosgun
Keyword(s):  
Ottoman Empire ◽  
Social Life ◽  
Russian Empire ◽  
Political Life ◽  
Social Patterns ◽  
Starting Point ◽  
Transition To Capitalism ◽  
The Russian Empire ◽  
External Forces

The point of origin in the comparison of the Ottoman Empire and the Russian Empire were not as different from each other unlike the similarities. Both empires has chosen to shape with their own internal dynamics and enclosed social life over the years. In addition, they have taken samples the West as their model for modernization. These Empires have been described as “other” by Western because of “Islam” in Ottoman Empire and “Orthodoxy” in Russian Empire. Similar social patterns, political unrest and modernization moves has been the starting point of the study. The study referred to in the title of “comparison” did not include the concept of the just determination of similarity. Although both empires have many similarities, there were many striking differences each other. The most obvious differences in etymologic, Ottoman bureaucracy designate modernization as “Westernization”, other side Russian administrators named modernization as “Europeanism”. Another notable element was observed in various economic lives. The transition to capitalism in the Ottoman Empire directed by external forces on the other hand, Russia gave direction to this transformation of its own volition. The purpose of study is to show the similarities and differences in the Ottoman and Russian modernization with using the comparative historical sociological method.Keywords: ottoman empire, russian empire, modernization, westernization, political life

Conformation of Ribosomes from Escherichia Coli

1974 ◽  
Vol 32 ◽  
pp. 210-211
Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins
Keyword(s):  
Binding Sites ◽  
Ribosomal Proteins ◽  
Fluorescent Dyes ◽  
Protein Biosynthesis ◽  
Three Dimensional ◽  
Spatial Arrangement ◽  
Dimensional Structure ◽  
Complete Understanding ◽  
And Function

The present knowledge of the three-dimensional structure of ribosomes is far too limited to enable a complete understanding of the various roles which ribosomes play in protein biosynthesis. The spatial arrangement of proteins and ribonuclec acids in ribosomes can be analysed in many ways. Determination of binding sites for individual proteins on ribonuclec acid and locations of the mutual positions of proteins on the ribosome using labeling with fluorescent dyes, cross-linking reagents, neutron-diffraction or antibodies against ribosomal proteins seem to be most successful approaches. Structure and function of ribosomes can be correlated be depleting the complete ribosomes of some proteins to the functionally inactive core and by subsequent partial reconstitution in order to regain active ribosomal particles.

Criteria and Methods for Reliable Three-Dimensional Image Reconstruction

1974 ◽  
Vol 32 ◽  
pp. 330-331
Author(s):  
R. A. Crowther
Keyword(s):  
Image Reconstruction ◽  
Finite Number ◽  
Density Distribution ◽  
Electron Micrographs ◽  
Mathematical Problem ◽  
Three Dimensional ◽  
Ideal Case ◽  
Dimensional Image ◽  
General Object ◽  
The Ideal

The reconstruction of a three-dimensional image of a specimen from a set of electron micrographs reduces, under certain assumptions about the imaging process in the microscope, to the mathematical problem of reconstructing a density distribution from a set of its plane projections.In the absence of noise we can formulate a purely geometrical criterion, which, for a general object, fixes the resolution attainable from a given finite number of views in terms of the size of the object. For simplicity we take the ideal case of projections collected by a series of m equally spaced tilts about a single axis.

Identification of N-Substituted Triazolo-azetidines as Novel Antibacterials using pDualrep2 HTS Platform

2019 ◽  
Vol 22 (5) ◽  
pp. 346-354
Author(s):  
Yan A. Ivanenkov ◽  
Renat S. Yamidanov ◽  
Ilya A. Osterman ◽  
Petr V. Sergiev ◽  
Vladimir A. Aladinskiy ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Large Scale ◽  
Underlying Mechanism ◽  
Luciferase Assay ◽  
Reporter System ◽  
E Coli ◽  
Starting Point ◽  
High Concentrations ◽  
Mic Value

Aim and Objective: Antibiotic resistance is a serious constraint to the development of new effective antibacterials. Therefore, the discovery of the new antibacterials remains one of the main challenges in modern medicinal chemistry. This study was undertaken to identify novel molecules with antibacterial activity. Materials and Methods: Using our unique double-reporter system, in-house large-scale HTS campaign was conducted for the identification of antibacterial potency of small-molecule compounds. The construction allows us to visually assess the underlying mechanism of action. After the initial HTS and rescreen procedure, luciferase assay, C14-test, determination of MIC value and PrestoBlue test were carried out. Results: HTS rounds and rescreen campaign have revealed the antibacterial activity of a series of Nsubstituted triazolo-azetidines and their isosteric derivatives that has not been reported previously. Primary hit-molecule demonstrated a MIC value of 12.5 µg/mL against E. coli Δ tolC with signs of translation blockage and no SOS-response. Translation inhibition (26%, luciferase assay) was achieved at high concentrations up to 160 µg/mL, while no activity was found using C14-test. The compound did not demonstrate cytotoxicity in the PrestoBlue assay against a panel of eukaryotic cells. Within a series of direct structural analogues bearing the same or bioisosteric scaffold, compound 2 was found to have an improved antibacterial potency (MIC=6.25 µg/mL) close to Erythromycin (MIC=2.5-5 µg/mL) against the same strain. In contrast to the parent hit, this compound was more active and selective, and provided a robust IP position. Conclusion: N-substituted triazolo-azetidine scaffold may be used as a versatile starting point for the development of novel active and selective antibacterial compounds.

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