scholarly journals Improved second-order unconditionally stable schemes of linear multi-step and equivalent single-step integration methods

2020 ◽  
Author(s):  
Huimin Zhang ◽  
Runsen Zhang ◽  
Pierangelo Masarati
Keyword(s):  
Unconditional Stability ◽  
Single Step ◽  
Second Order ◽  
Step Method ◽  
Unconditionally Stable ◽  
Integration Methods ◽  
Optimal Accuracy ◽  
Intermediate Variables ◽  
First Time ◽  
Multi Step Methods

AbstractSecond-order unconditionally stable schemes of linear multi-step methods, and their equivalent single-step methods, are developed in this paper. The parameters of the linear two-, three-, and four-step methods are determined for optimal accuracy, unconditional stability and tunable algorithmic dissipation. The linear three- and four-step schemes are presented for the first time. As an alternative, corresponding single-step methods, spectrally equivalent to the multi-step ones, are developed by introducing the required intermediate variables. Their formulations are equivalent to that of the corresponding multi-step methods; their use is more convenient, owing to being self-starting. Compared with existing second-order methods, the proposed ones, especially the linear four-step method and its alternative single-step one, show higher accuracy for a given degree of algorithmic dissipation. The accuracy advantage and other properties of the newly developed schemes are demonstrated by several illustrative examples.

High Accuracy Method for Magnetohydrodynamics System in Elsässer Variables

2015 ◽  
Vol 15 (1) ◽  
pp. 97-110 ◽  
Author(s):  
Nicholas Wilson ◽  
Alexander Labovsky ◽  
Catalin Trenchea
Keyword(s):  
Test Problem ◽  
Correction Method ◽  
High Accuracy ◽  
Unconditional Stability ◽  
Step Method ◽  
Order Accuracy ◽  
Unconditionally Stable ◽  
The Third ◽  
Coupling Terms ◽  
Mhd System

AbstractA method has been developed recently by the third author, that allows for decoupling of the evolutionary full magnetohydrodynamics (MHD) system in the Elsässer variables. The method entails the implicit discretization of the subproblem terms and the explicit discretization of coupling terms, and was proven to be unconditionally stable. In this paper we build on that result by introducing a high-order accurate deferred correction method, which also decouples the MHD system. We perform the full numerical analysis of the method, proving the unconditional stability and second order accuracy of the two-step method. We also use a test problem to verify numerically the claimed convergence rate.

Unique perforated graphene derived from Bougainvillea flowers for high-power supercapacitors: a green approach

Nanoscale ◽  
2017 ◽  
Vol 9 (14) ◽  
pp. 4801-4809 ◽  
Author(s):  
Rajendra P. Panmand ◽  
Purnima Patil ◽  
Yogesh Sethi ◽  
Sunil R. Kadam ◽  
Milind V. Kulkarni ◽  
...  
Keyword(s):  
Surface Area ◽  
High Power ◽  
High Surface ◽  
High Surface Area ◽  
Single Step ◽  
Step Method ◽  
Green Approach ◽  
Template Free ◽  
First Time

Herein, we demonstrated a green approach for the synthesis of high surface area (850 m2 g−1) mesoporous perforated graphene (PG) from Bougainvillea flower for the first time using a template free single-step method.

scholarly journals Feedback Control of a Foldable Delta Mechanism with Integrated Inkjet-Printed Angle Sensors

2021 ◽  
Author(s):  
Dila Türkmen ◽  
Merve Acer Kalafat
Keyword(s):  
Feedback Control ◽  
Single Step ◽  
Radius Of Curvature ◽  
Step Method ◽  
Angle Sensor ◽  
Proportional Control ◽  
Printed Sensors ◽  
Hinge Position ◽  
The Difference ◽  
First Time

Foldable robotics is accepted as one of the leading technologies in the soft robotics field. Integrating the sensing components, including hinge angle proprioception, into the robot with a single fabrication method is a part of the field’s ultimate goal. Here we present a cheap single-step method for angle sensing integration into the hinges, with an accurate and reproducible performance. We use silver nanoparticle inkjet printing on the flexible structural layer (PET) of the foldable robot (i.e. Delta robot), using an office-type printer. Silver printed sensors were studied for slight bending applications; however, we report their behavior under a 1 mm minimum radius of curvature, an advanced range both for silver strain sensors and any printed hinge position sensors. Among the three patterns studied, one gave a mean absolute dynamic hysteresis error below 1 degree. Reproducibility of a printed angle sensor behavior is reported for the first time, with three prototypes of each pattern (2degree standard deviation). Printed sensor feedback is tested with proportional control for the first time, via set-point and tracking tasks. On-off control law is also implemented and errors below 1 degree are achieved. Proportional control performances are compared with encoder feedback control and the difference between the realized trajectories are found to be under 1 mm in the task plane.<br>

scholarly journals Feedback Control of a Foldable Delta Mechanism with Integrated Inkjet-Printed Angle Sensors

2021 ◽  
Author(s):  
Dila Türkmen ◽  
Merve Acer Kalafat
Keyword(s):  
Feedback Control ◽  
Single Step ◽  
Radius Of Curvature ◽  
Step Method ◽  
Angle Sensor ◽  
Proportional Control ◽  
Printed Sensors ◽  
Hinge Position ◽  
The Difference ◽  
First Time

Foldable robotics is accepted as one of the leading technologies in the soft robotics field. Integrating the sensing components, including hinge angle proprioception, into the robot with a single fabrication method is a part of the field’s ultimate goal. Here we present a cheap single-step method for angle sensing integration into the hinges, with an accurate and reproducible performance. We use silver nanoparticle inkjet printing on the flexible structural layer (PET) of the foldable robot (i.e. Delta robot), using an office-type printer. Silver printed sensors were studied for slight bending applications; however, we report their behavior under a 1 mm minimum radius of curvature, an advanced range both for silver strain sensors and any printed hinge position sensors. Among the three patterns studied, one gave a mean absolute dynamic hysteresis error below 1 degree. Reproducibility of a printed angle sensor behavior is reported for the first time, with three prototypes of each pattern (2degree standard deviation). Printed sensor feedback is tested with proportional control for the first time, via set-point and tracking tasks. On-off control law is also implemented and errors below 1 degree are achieved. Proportional control performances are compared with encoder feedback control and the difference between the realized trajectories are found to be under 1 mm in the task plane.<br>

scholarly journals One-Parameter Controlled Non-Dissipative Unconditionally Stable Explicit Structure-Dependent Integration Methods with No Overshoot

2021 ◽  
Vol 11 (24) ◽  
pp. 12109
Author(s):  
Veerarajan Selvakumar ◽  
Shuenn-Yih Chang
Keyword(s):  
Time Integration ◽  
Unconditional Stability ◽  
Second Order ◽  
Numerical Dissipation ◽  
Implicit Methods ◽  
Time Step ◽  
Order Accuracy ◽  
Structural Dynamic ◽  
Integration Methods ◽  
New Family

Although many families of integration methods have been successfully developed with desired numerical properties, such as second order accuracy, unconditional stability and numerical dissipation, they are generally implicit methods. Thus, an iterative procedure is often involved for each time step in conducting time integration. Many computational efforts will be consumed by implicit methods when compared to explicit methods. In general, the structure-dependent integration methods (SDIMs) are very computationally efficient for solving a general structural dynamic problem. A new family of SDIM is proposed. It exhibits the desired numerical properties of second order accuracy, unconditional stability, explicit formulation and no overshoot. The numerical properties are controlled by a single free parameter. The proposed family method generally has no adverse disadvantage of unusual overshoot in high frequency transient responses that have been found in the currently available implicit integration methods, such as the WBZ-α method, HHT-α method and generalized-α method. Although this family method has unconditional stability for the linear elastic and stiffness softening systems, it becomes conditionally stable for stiffness hardening systems. This can be controlled by a stability amplification factor and its unconditional stability is successfully extended to stiffness hardening systems. The computational efficiency of the proposed method proves that engineers can do the accurate nonlinear analysis very quickly.

Purification of Urokinase from Complex Mixtures Using Immobilized Monoclonal Antibody Against Urokinase Light Chain

1983 ◽  
Vol 49 (01) ◽  
pp. 024-027 ◽  
Author(s):  
David Vetterlein ◽  
Gary J Calton
Keyword(s):  
Monoclonal Antibody ◽  
Light Chain ◽  
Culture Media ◽  
Biological Fluids ◽  
Single Step ◽  
High Yield ◽  
Step Method ◽  
Commercial Preparation ◽  
E Coli ◽  
Tissue Culture Media

SummaryThe preparation of a monoclonal antibody (MAB) against high molecular weight (HMW) urokinase light chain (20,000 Mr) is described. This MAB was immobilized and the resulting immunosorbent was used to isolate urokinase starting with an impure commercial preparation, fresh urine, spent tissue culture media, or E. coli broth without preliminary dialysis or concentration steps. Monospecific antibodies appear to provide a rapid single step method of purifying urokinase, in high yield, from a variety of biological fluids.

scholarly journals Broad scope gold(i)-catalysed polyenyne cyclisations for the formation of up to four carbon–carbon bonds

2017 ◽  
Vol 15 (10) ◽  
pp. 2163-2167 ◽  
Author(s):  
Zhouting Rong ◽  
Antonio M. Echavarren
Keyword(s):  
Single Step ◽  
Simultaneous Formation ◽  
Broad Scope ◽  
Carbon Carbon Bonds ◽  
Carbon Bonds ◽  
First Time ◽  
High Stereoselectivity

The polycyclisation of polyeneynes catalyzed by gold(i) has been extended for the first time to the simultaneous formation of up to four carbon–carbon bonds, leading to steroid-like molecules with high stereoselectivity in a single step with low catalyst loadings.

scholarly journals Second-order neutrosophic boundary-value problem

2021 ◽  
Author(s):  
Sandip Moi ◽  
Suvankar Biswas ◽  
Smita Pal(Sarkar)
Keyword(s):  
Differential Equation ◽  
Boundary Value Problem ◽  
Differential Calculus ◽  
Boundary Value ◽  
Second Order ◽  
Numerical Examples ◽  
Different Types ◽  
First Time

AbstractIn this article, some properties of neutrosophic derivative and neutrosophic numbers have been presented. This properties have been used to develop the neutrosophic differential calculus. By considering different types of first- and second-order derivatives, different kind of systems of derivatives have been developed. This is the first time where a second-order neutrosophic boundary-value problem has been introduced with different types of first- and second-order derivatives. Some numerical examples have been examined to explain different systems of neutrosophic differential equation.

scholarly journals Pioneer Legislation on Second Order of Sexual Harassment: Sociolegal Innovation in Addressing Sexual Harassment

2021 ◽  
Author(s):  
Ana Vidu ◽  
Gema Tomás ◽  
Ramon Flecha
Keyword(s):  
Sexual Harassment ◽  
Women's Studies ◽  
Legal System ◽  
Scientific Evidence ◽  
Second Order ◽  
Bystander Intervention ◽  
Policy Implications ◽  
Women’S Studies ◽  
Key Innovation ◽  
First Time

Abstract Backgroud Countless efforts to combat sexual harassment have been proposed, and for the first time in history, the second order of sexual harassment (SOSH) has been legislated under the term second-order violence (SOV) by a unanimous vote of the Catalan Parliament. Advances in preventing and responding to sexual harassment contribute to highlighting the intervention as being crucial to supporting survivors against retaliation. A lack of support provides a general explanation on why bystanders tend not to intervene and highlights the reality that reprisals are suffered by those who support victims. Methods From the existing knowledge about sexual harassment prevention and response mechanisms, this paper analyzes scientific evidence through a review of the literature published in databases, as well as legislation, reports, and other materials. Results The context that enables SOV legislation is grounded in three realms: (1) bystander intervention and protection, (2) the role of support networks in protecting survivors, and (3) awareness and legislation of SOSH. An active bystander refers to the involvement of someone who is aware of potential sexual harassment situations. Conclusions The lack of legislation against SOSH limits bystander intervention and support; therefore, legislating protection for supporters has become urgent and necessary. Legislating SOSH has great social implications because gender equality cannot be fully achieved if bystander protection is not legally considered. Policy Implications: As no legal system has previously contemplated SOSH, its pioneering parliamentarian approval and establishment by Catalan law constitute a legal key innovation for the field of gender and women’s studies. In fact, evidence reported here are important in developing further regulations and policy. Policy Implications As no legal system has previously contemplated SOSH, its pioneering parliamentarian approval and establishment by Catalan law constitute a legal key innovation for the field of gender and women’s studies. In fact, evidence reported here are important in developing further regulations and policy.

scholarly journals High-resolution limited-angle phase tomography of dense layered objects using deep neural networks

2019 ◽  
Vol 116 (40) ◽  
pp. 19848-19856 ◽  
Author(s):  
Alexandre Goy ◽  
Girish Rughoobur ◽  
Shuai Li ◽  
Kwabena Arthur ◽  
Akintunde I. Akinwande ◽  
...  
Keyword(s):  
Integrated Circuit ◽  
Deep Neural Networks ◽  
Tomographic Reconstruction ◽  
Synthetic Data ◽  
Single Step ◽  
Training Set ◽  
Step Method ◽  
3 Dimensional ◽  
Dimensional Reconstruction ◽  
Optical Domain

We present a machine learning-based method for tomographic reconstruction of dense layered objects, with range of projection angles limited to ±10○. Whereas previous approaches to phase tomography generally require 2 steps, first to retrieve phase projections from intensity projections and then to perform tomographic reconstruction on the retrieved phase projections, in our work a physics-informed preprocessor followed by a deep neural network (DNN) conduct the 3-dimensional reconstruction directly from the intensity projections. We demonstrate this single-step method experimentally in the visible optical domain on a scaled-up integrated circuit phantom. We show that even under conditions of highly attenuated photon fluxes a DNN trained only on synthetic data can be used to successfully reconstruct physical samples disjoint from the synthetic training set. Thus, the need for producing a large number of physical examples for training is ameliorated. The method is generally applicable to tomography with electromagnetic or other types of radiation at all bands.

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