Time Domain NMR in Polymer Science: From the Laboratory to the Industry

Highly controlled polymers and nanostructures are increasingly translated from the lab to the industry. Together with the industrialization of complex systems from renewable sources, a paradigm change in the processing of plastics and rubbers is underway, requiring a new generation of analytical tools. Here, we present the recent developments in time domain NMR (TD-NMR), starting with an introduction of the methods. Several examples illustrate the new take on traditional issues like the measurement of crosslink density in vulcanized rubber or the monitoring of crystallization kinetics, as well as the unique information that can be extracted from multiphase, nanophase and composite materials. Generally, TD-NMR is capable of determining structural parameters that are in agreement with other techniques and with the final macroscopic properties of industrial interest, as well as reveal details on the local homogeneity that are difficult to obtain otherwise. Considering its moderate technical and space requirements of performing, TD-NMR is a good candidate for assisting product and process development in several applications throughout the rubber, plastics, composites and adhesives industry.

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Small-Angle Scattering from Fractional Brownian Surfaces

Symmetry ◽

10.3390/sym13112042 ◽

2021 ◽

Vol 13 (11) ◽

pp. 2042

Author(s):

Eugen Mircea Anitas

Keyword(s):

Small Angle ◽

Structural Parameters ◽

Small Angle Scattering ◽

Distribution Functions ◽

Advanced Materials ◽

Two Phase ◽

Amorphous Phases ◽

Angle Scattering ◽

Recent Developments ◽

New Generation

Recent developments in nanotechnology have allowed the fabrication of a new generation of advanced materials with various fractal-like geometries. Fractional Brownian surfaces (fBs) are often used as models to simulate and characterize these complex geometries, such as the surface of particles in dilute particulate systems (e.g., colloids) or the interfaces in non-particulate two-phase systems (e.g., semicrystalline polymers with crystalline and amorphous phases). However, for such systems, a realistic simulation involves parameters averaged over a macroscopic volume. Here, a method based on small-angle scattering technique is proposed to extract the main structural parameters of surfaces/interfaces from experimental data. It involves the analysis of scattering intensities and the corresponding pair distance distribution functions. This allows the extraction of information with respect to the overall size, fractal dimension, Hurst and spectral exponents. The method is applied to several classes of fBs, and it is shown that the obtained numerical values of the structural parameters are in very good agreement with theoretical ones.

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Recent developments in low-voltage SEM of polymers

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100150162 ◽

1993 ◽

Vol 51 ◽

pp. 866-867

Author(s):

S.J. Krause ◽

W.W. Adams

Keyword(s):

Low Voltage ◽

Chromatic Aberration ◽

Thermal Electron ◽

Analytical Technique ◽

Recent Developments ◽

Beam Currents ◽

New Generation ◽

First Time ◽

Voltage Scanning ◽

Beam Damage

Over the past decade low voltage scanning electron microscopy (LVSEM) of polymers has evolved from an interesting curiosity to a powerful analytical technique. This development has been driven by improved instrumentation and in particular, reliable field emission gun (FEG) SEMs. The usefulness of LVSEM has also grown because of an improved theoretical and experimental understanding of sample-beam interactions and by advances in sample preparation and operating techniques. This paper will review progress in polymer LVSEM and present recent results and developments in the field.In the early 1980s a new generation of SEMs produced beam currents that were sufficient to allow imaging at low voltages from 5keV to 0.5 keV. Thus, for the first time, it became possible to routinely image uncoated polymers at voltages below their negative charging threshold, the "second crossover", E2 (Fig. 1). LVSEM also improved contrast and reduced beam damage in sputter metal coated polymers. Unfortunately, resolution was limited to a few tenths of a micron due to the low brightness and chromatic aberration of thermal electron emission sources.

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The Development of Lagoons in Venezuela

Water Science & Technology ◽

10.2166/wst.1987.0126 ◽

1987 ◽

Vol 19 (12) ◽

pp. 55-60 ◽

Cited By ~ 1

Author(s):

M. Lansdell

Keyword(s):

Treatment Option ◽

Sewage Treatment ◽

Operational Experience ◽

Cost Information ◽

Anaerobic Baffled Reactor ◽

Space Saving ◽

Under Construction ◽

Space Requirements ◽

New Generation ◽

Lagoon Systems

The operational experience of early lagoons is outlined. The construction of a new generation of lagoons of 2000 PE to 1.000.000 PE capacity and associated practical difficulties are described. Those with innovative and space saving features treated in some detail. One includes an anaerobic baffled reactor with sludge draw-off facilities which entered service in September 1986 and which is being monitored for compliance with “Engelberg Requirements”. Cost information and space requirements for the different systems under construction are included.It is concluded that lagoon systems properly designed and sited are the most appropriate and indeed the only financially viable sewage treatment option to suit Venezuelan circumstances.

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A Reference Framework to Combine Model-Based Design and AR to Improve Social Sustainability

Sustainability ◽

10.3390/su13042031 ◽

2021 ◽

Vol 13 (4) ◽

pp. 2031

Author(s):

Fabio Grandi ◽

Riccardo Karim Khamaisi ◽

Margherita Peruzzini ◽

Roberto Raffaeli ◽

Marcello Pellicciari

Keyword(s):

Positive Impact ◽

Cost Effective ◽

Digital Models ◽

Model Based ◽

Digital Contents ◽

Recent Developments ◽

Virtual Simulations ◽

Product And Process ◽

The Impact ◽

Time Information

Product and process digitalization is pervading numerous areas in the industry to improve quality and reduce costs. In particular, digital models enable virtual simulations to predict product and process performances, as well as to generate digital contents to improve the general workflow. Digital models can also contain additional contents (e.g., model-based design (MBD)) to provide online and on-time information about process operations and management, as well as to support operator activities. The recent developments in augmented reality (AR) offer new specific interfaces to promote the great diffusion of digital contents into industrial processes, thanks to flexible and robust applications, as well as cost-effective devices. However, the impact of AR applications on sustainability is still poorly explored in research. In this direction, this paper proposed an innovative approach to exploit MBD and introduce AR interfaces in the industry to support human intensive processes. Indeed, in those processes, the human contribution is still crucial to guaranteeing the expected product quality (e.g., quality inspection). The paper also analyzed how this new concept can benefit sustainability and define a set of metrics to assess the positive impact on sustainability, focusing on social aspects.

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Concept for an integrated product and process development of electric drives using a knowledge-based system

2017 7th International Electric Drives Production Conference (EDPC) ◽

10.1109/edpc.2017.8328157 ◽

2017 ◽

Cited By ~ 9

Author(s):

Andreas Mayr ◽

Alexander Meyer ◽

Philipp Gonnheimer ◽

Jonas Gramlich ◽

Maximilian Reiser ◽

...

Keyword(s):

Process Development ◽

Electric Drives ◽

Knowledge Based System ◽

Knowledge Based ◽

Product And Process

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Development of a computer-aided concurrent net shape product and process development environment

Robotics and Computer-Integrated Manufacturing ◽

10.1016/s0736-5845(97)00015-x ◽

1997 ◽

Vol 13 (4) ◽

pp. 337-360 ◽

Cited By ~ 16

Author(s):

Yuh-Min Chen

Keyword(s):

Process Development ◽

Development Environment ◽

Computer Aided ◽

Product And Process

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Modal Control by Modal Force Technique

13th Biennial Conference on Mechanical Vibration and Noise: Modal Analysis, Modeling, Diagnostics, and Control — Analytical and Experimental ◽

10.1115/detc1991-0363 ◽

1991 ◽

Author(s):

C. D. Tsai ◽

M. S. Ju ◽

Y. G. Tsuei

Keyword(s):

Feedback Control ◽

Control Problem ◽

Efficient Method ◽

Time Domain ◽

Modal Control ◽

Global Dynamic ◽

Recent Developments ◽

Modal Force ◽

Frequency Domain Approach ◽

Direct Feedback

Abstract Modal control of structure requires the estimation of the modal states variables for feedback. One approach that does not require modal states variables estimation is the direct feedback control. Recent developments in modal control for direct feedback are mainly time domain methods. In this paper, an efficient method based on frequency domain approach named Modal Force Technique is developed. The method not only allows one to modify the global dynamic behavior of the synthesized structure but also can be utilized for modal control problem if the acceleration, velocity and displacement feedbacks are used.

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