12 Dokumente gefunden

Alcoholic Compounds : Physical Properties and Classification Categories, Including Monohydric, Dihydric, Polyhydric and Carbohydrate…

The relationships between molar mass ( M ), density ( ρ ), relative static permittivity ( ε r ), and refractive index ( n D 20 $n_{\text{D}}^{20}$ ) of alcohol derivatives are investigated. It is important to determine the partial molar concentration of hydroxyl groups ( N OH ) and the partial molar…
Weinheim: Wiley, 2025-09-22

Understanding and Employing (Non-)Linearities in Attenuated Total Reflection Spectroscopy

When Beer's law is interpreted through electromagnetic theory, it becomes clear that assuming a linear relationship between molar concentration and the imaginary part of the dielectric function is more accurate than using the absorption index function. A similar relationship holds true for attenuated…
Sage UK: London, England: SAGE Publications, 2025-01-13

Theoretical Calculation and Simulation of Peak Distortion of Absorption Spectra of Complex Mixtures

Attenuated total reflection (ATR) spectroscopy in infrared is a standard tool used in most analytical labs, as it allows a rapid chemical analysis with virtually no sample preparation. However, when the sample contains materials with a high refractive index, special care must be taken as the resulting…
Sage UK: London, England: SAGE Publications, 2024-12-10

Developing Correction Methods by Revisiting the Concept of Effective Thickness in Attenuated Total Reflection Spectroscopy

We propose a new way of deriving the effective thickness in attenuated total reflection (ATR) spectroscopy, initially introduced by Hansen and Harrick in 1965. While following Hansen's approach, our derivation is more straightforward and includes an intermediate approximation that more closely aligns…
Sage UK: London, England: SAGE Publications, 2024-09-13

Combining Infrared Refraction and Attenuated Total Reflection Spectroscopy

We have specified and obtained a ZnSe prism with an unconventional face angle cut to 30°. This prism, with internal incidence angles ranging from 30° to 48°, allows users to record internal reflection spectra below the critical angle and attenuated total reflection (ATR) spectra above the critical angle…
Sage UK: London, England: SAGE Publications, 2024-08-10

Understanding Advanced Attenuated Total Reflection Correction : The Low Absorbance Assumption

We present an attenuated total reflection (ATR) correction scheme capable of rectifying ATR spectra while considering the polarization state for arbitrary angles of incidence, provided that this angle exceeds the critical angle for the entire ATR spectrum. Due to its reliance on the weak absorption approximation,…
Sage UK: London, England: SAGE Publications, 2024-08-01

Simple, Fast and Convenient Magnetic Bead-Based Sample Preparation for Detecting Viruses via Raman-Spectroscopy

We introduce a magnetic bead-based sample preparation scheme for enabling the Raman spectroscopic differentiation of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2)-positive and -negative samples. The beads were functionalized with the angiotensin-converting enzyme 2 (ACE2) receptor…
Basel: MDPI, 2023-05-30

The Global Polarity of Alcoholic Solvents and Water : Importance of the Collectively Acting Factors Density, Refractive Index…

The D HBD quantity represents the hydroxyl group density of alcoholic solvents or water. D HBD is purely physically defined by the product of molar concentration of the solvent ( N ) and the factor Σn=n× f which reflects the number n and position ( f ‐factor) of the alcoholic OH groups per molecule.…
Weinheim: Wiley-VCH-Verl., 2022-10-25

Structures for surface-enhanced nonplasmonic or hybrid spectroscopy

Absorption, scattering, and fluorescence are processes that increase with electric field intensity. The most prominent way to enhance electric field intensity is to use localized or propagating surface plasmon polaritons (SPPs) based on metallic particles and nanostructures. In addition, several other,…
Berlin: De Gruyter, 2020-03-18

Periodic array-based substrates for surface-enhanced infrared spectroscopy

At the beginning of the 1980s, the first reports of surface-enhanced infrared spectroscopy (SEIRS) surfaced. Probably due to signal-enhancement factors of only 10 1 to 10 3 , which are modest compared to those of surface-enhanced Raman spectroscopy (SERS), SEIRS did not reach the same significance up…
Berlin: De Gruyter, 2018-01-01

Generalized dispersion analysis of arbitrarily cut crystals with unknown orientation

To perform generalized dispersion analysis of arbitrarily cut crystals with a priori unknown orientation an appropriate set of spectra and evaluation scheme to reproduce the measured spectra is necessary. In this thesis a detailed procedure that respects the characteristic symmetries of each crystal…

Smart Error Sum Based on Hybrid Two-Trace Two-Dimensional (2T2D) Correlation Analysis

Based on hybrid 2D correlation analysis, we recently derived and introduced a “smart error sum,” a sophisticated loss function that can be used for solving nonlinear inverse problems like the determination of optical constants and oscillator parameters from a series of optical spectra in the infrared…
Sage UK: London, England: SAGE Publications, 1952