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Documentation in support of your JEOL product.

Introduction of a method to analyze 3D structures using homonuclear couplings_NM210004E

Structural analysis by NMR can provide not only a planar molecular structure but also three-dimensional structural information. In this Note, we describe a method for obtaining information on dihedral angles by using 1H-1H coupling constants (JHH values). For example, hydrogen atoms attached to a cyclohexane ring are either located in axial or equatorial positions in respect to the cyclohexane ring (Fig. 1). The dihedral angles between vicinal protons are known to be ∠Hax-C-C-Hax ≈ 180°, ∠Hax-C-Heq ≈ 60°, and ∠Heq-C-C-Heq ≈ 60°. If we look at the Karplus curve shown in Fig. 2, we can see that 3JHH of around 4 Hz can be expected in the case of the dihedral angle of 60°, while 3JHH of around 13 Hz corresponds to the dihedral angle of 180°. In reality, 3JHH values depend on substituents attached to the cyclohexane ring in substituted cyclohexanes, so the analysis is not straightforward, but the basic trend of having a larger J-value for a 180° dihedral angle compared to a 60° dihedral angle remains unchanged. Therefore, from the value of 3JHH of the methylene protons, it is possible to differentiate between the dihedral angle of 60° or 180°.

20 T/m high field gradient strength diffusion measurement system_NM210006E

The new generation diffusion probe is specially designed for diffusion applications that requires a large magnetic field gradient. By improving the design around the coil, the recovery time after field gradient pulse has been significantly shortened compared to the conventional model. Using a newly developed 50A bipolar magnetic field gradient power supply, a magnetic field gradient of 20 T/m (2000 G/cm) can be applied, making it possible to measure diffusion coefficients on the order of 10-14 m2/s. This system is ideal for measuring the diffusion of ions in solid electrolytes.

Lithium Ion Battery Note

The applications for lithium ion batteries (LIB) cover a wide range, from power sources for personal computers and mobile devices to automobiles, and there is always a demand for even better performance and safety. In order to ensure the performance and quality of LIB, analysis and evaluation using high-performance assessment systems is necessary. JEOL offers a full line-up of equipment to support the development of new LIB technologies and to improve product quality, including instruments for morphology observation and surface analysis, chemical analysis systems to perform structural analysis on a molecular level, as well as fabrication systems to create high-performance coatings and powders. This LIB note offers solutions for researchers and engineers who are looking for the best equipment for their application.

Food Analysis Solutions

JEOL offers numerous analytical tools to support both "food safety & security" as well as various evaluations of primary, secondary and tertiary functions of foodstuffs which are useful for a wide range of users associated with this field. This Foodnote introduces the features of each of the instruments and actual analysis examples, and is designed for researchers and engineers who are considering purchases of instruments. This brochure also presents comprehensive evaluations and analysis solutions that can be achieved with combinations of multiple instruments.

Learning Polymer Materials Analysis from Natural Lacquer (Urushi)

Introduction: In recent years, polymer materials have become more complex due to increased composition and diversification so that a one-sided analysis is insufficient and multifaceted observations and analyses are required. In response to this need, JEOL has engaged in applied research under the keyword of "YOKOGUSHI" (multifaceted cross-instrumental) using various instruments organically. In this Urushi Note, multifaceted analysis methods for polymer materials are illustrated using the examples of natural lacquer (urushi) analysis.

JEOL Case Study: Lowell NMR

University of Massachusetts Lowell’s NMR Spectroscopy Facility Manager, Wendy Gavin, discusses the importance of an NMR vendor that supports the constant challenge to be innovative. With over 13 years spent working in industry, 11 in a large pharmaceutical company, it is safe to say that Wendy Gavin knows the secret to successful nuclear magnetic resonance (NMR). Wendy has worked at the university for over six years and, as well as being the NMR Core Research Facility Manager, she also manages the University’s Analytical Chemistry lab. Her experience working in industry has provided unique insights into a customer’s requirements and enables her to ensure that the NMR facility at the University of Massachusetts Lowell is providing high quality data. Here, she explains the difference it makes to have an instrumentation vendor that goes the extra mile to support all users.

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Corona - Glow Discharge (DART Ion Source)

February 22, 2020
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