H Kaur Book Spectroscopy Pdf 17l
Hermogenes Smardon
The present study gives a brief introduction to sum-frequency generation (SFG) vibrational spectroscopy with an overview of the role of second-order nonlinear optical process. Here, we have emphasized on theoretical aspects of the SFG spectroscopy and the spectral analysis to extract the molecular structure and orientation of interfacial molecules. The interfacial structural information of various polymer materials plays an important role to determine properties like adhesion, friction, and wettability. Therefore, we have investigated the molecular structure of polydimethylsiloxane (PDMS) polymer films at the air/polymer interface by using SFG spectroscopy. The vibrational signatures of the PDMS polymer and the intensity of the SFG signal are recorded by varying the molecular weight of the PDMS polymer. The average orientation tilt angle and angular distribution width of methyl groups for each PDMS polymer are determined. The SFG results reveal the change in the intensity of SFG signals and the change in molecular tilt angle and angular distribution of methyl groups at air/PDMS film interface with the variation in the molecular weight of PDMS. The SFG spectral analysis reveals that the molecular tilt angle of the methyl group varies from 49 to 75 with respect to the surface normal and the angular distribution varies from 0 to 30 for all the PDMS polymer samples. It is interesting to find that the tilt angle of the methyl functional group of the PDMS polymer at the air/polymer interface can be controlled by varying the molecular weight of the polymer.
N2 - The present study gives a brief introduction to sum-frequency generation (SFG) vibrational spectroscopy with an overview of the role of second-order nonlinear optical process. Here, we have emphasized on theoretical aspects of the SFG spectroscopy and the spectral analysis to extract the molecular structure and orientation of interfacial molecules. The interfacial structural information of various polymer materials plays an important role to determine properties like adhesion, friction, and wettability. Therefore, we have investigated the molecular structure of polydimethylsiloxane (PDMS) polymer films at the air/polymer interface by using SFG spectroscopy. The vibrational signatures of the PDMS polymer and the intensity of the SFG signal are recorded by varying the molecular weight of the PDMS polymer. The average orientation tilt angle and angular distribution width of methyl groups for each PDMS polymer are determined. The SFG results reveal the change in the intensity of SFG signals and the change in molecular tilt angle and angular distribution of methyl groups at air/PDMS film interface with the variation in the molecular weight of PDMS. The SFG spectral analysis reveals that the molecular tilt angle of the methyl group varies from 49 to 75 with respect to the surface normal and the angular distribution varies from 0 to 30 for all the PDMS polymer samples. It is interesting to find that the tilt angle of the methyl functional group of the PDMS polymer at the air/polymer interface can be controlled by varying the molecular weight of the polymer.
AB - The present study gives a brief introduction to sum-frequency generation (SFG) vibrational spectroscopy with an overview of the role of second-order nonlinear optical process. Here, we have emphasized on theoretical aspects of the SFG spectroscopy and the spectral analysis to extract the molecular structure and orientation of interfacial molecules. The interfacial structural information of various polymer materials plays an important role to determine properties like adhesion, friction, and wettability. Therefore, we have investigated the molecular structure of polydimethylsiloxane (PDMS) polymer films at the air/polymer interface by using SFG spectroscopy. The vibrational signatures of the PDMS polymer and the intensity of the SFG signal are recorded by varying the molecular weight of the PDMS polymer. The average orientation tilt angle and angular distribution width of methyl groups for each PDMS polymer are determined. The SFG results reveal the change in the intensity of SFG signals and the change in molecular tilt angle and angular distribution of methyl groups at air/PDMS film interface with the variation in the molecular weight of PDMS. The SFG spectral analysis reveals that the molecular tilt angle of the methyl group varies from 49 to 75 with respect to the surface normal and the angular distribution varies from 0 to 30 for all the PDMS polymer samples. It is interesting to find that the tilt angle of the methyl functional group of the PDMS polymer at the air/polymer interface can be controlled by varying the molecular weight of the polymer.
Infrared spectroscopy became useful in the analysis of bacteria only with the advent of Fourier transform infrared (FTIR) instruments, improvements in laser design, higher signal to noise ratio coupled with significant advances in computing power and the utilization of chemometric analysis (Naumann et al. 1991). Chemometrics techniques enabled replacement of complex multidimensional spectral dataset by a simplified version with fewer dimensions which facilitates easy analysis of variance. Moreover recent advances in detector technology and attenuated total reflectance (ATR) accessory have made the analysis of biological samples simpler and faster (Movasaghi et al. 2008). The major advantage of infrared spectroscopy is reagent-less analysis. Fourier transform infrared (FT-IR) spectroscopy combined with multivariate statistical tools has been used to identify and classify microorganisms based on their specific biochemical fingerprint in various fields such as clinical applications (Horbach et al. 1988; Helm et al. 1991a, 1991b; Maquelin et al. 2002; Miguel Gómez et al. 2003); food industry (Amiel et al. 2000; Lefier et al. 2000; Lucia et al. 2001; Guibet et al. 2003) and to monitor microbial spoilage in food products (Ellis and Goodacre 2001; Kummerle et al. 1998; Ellis et al. 2002; Nicolaou and Goodacre 2008; Lu and Rasco 2010). FTIR spectroscopy has been successfully compared with the classical methods of identification and classification (Van der Mei et al. 1993). Al-Qadiri et al. (2006) had successfully employed FTIR spectroscopy and multivariate analysis to detect Pseudomonas aeruginosa and Escherichia coli in bottled drinking water.
The charge character of Andreev bound states (ABSs) in a three-terminal semiconductor-superconductor hybrid nanowire was measured using local and nonlocal tunneling spectroscopy. The device is fabricated using an epitaxial InAs/Al two-dimensional heterostructure with several gate-defined side probes. ABSs give rise to distinct local and nonlocal conductance signatures which evolve as a function of magnetic field and gate voltage. At high magnetic fields, ABSs are found to oscillate around zero as a function of gate voltage, with modifications of their charge consistent with expectations for the total Bardeen-Cooper-Schrieffer charge of ABSs.
In the Kaur Lab, the research aims to understand the complex biology and interactions of immune cells and their effector molecules with the sensory cells in the cochlea of the inner ear and how these interactions influence hearing, hearing loss and sensory cell development, degeneration, repair, survival, and plasticity. Inner ear contains a resident population of macrophages (innate-immune cells). Importantly, sensorineural hearing loss due to ototoxic side effects of certain medications, noise trauma, infections or healthy aging is associated with inflammation and robust activation and increase in numbers of macrophages. However, the precise functions of macrophages and inflammation are unclear. We are addressing these fundamental questions by utilizing cutting-edge mouse genetics, electrophysiological, pharmacological, high resolution fluorescent and electron microscopy, tissue culturing, mass spectroscopy, omics, molecular and biochemical approaches. Our long-term goal is to decipher the diversity and functions of immune cells and molecules in normal and pathological ears and to develop novel immunotherapies to prevent and/or restore loss of hearing and sensory cells and to maximize hearing aids and cochlear implant technologies for treating sensorineural hearing loss.
As one chemical composition, nicotine content has an important influence on the quality of tobacco leaves. Rapid and non-destructive quantitative analysis of nicotine is an important task in the tobacco industry. Near-infrared (NIR) spectroscopy as an effective chemical-composition analysis technique has been widely used. In this paper, we propose a one-dimensional Fully Convolutional Network (1D-FCN) model to quantitatively analyze the nicotine composition of tobacco leaves using NIRspectroscopy data in a cloud environment. This 1D-FCN model uses one-dimension convolution layers to directly extract the complex features from sequential spectroscopy data. It consists of five convolutional layers and two full connection layers with the max-pooling layer replaced by a convolutional layer to avoid information loss.Cloud computing techniques are used to solve the increasing requests of large-size data analysis and implement data sharing and accessing.Experimental results show that the proposed 1D-FCN model can effectively extract the complex characteristics inside the spectrum and more accurately predict the nicotine volumes in tobacco leaves than other approaches. This research provides a deep learning foundation for quantitative analysis of NIR spectra data in the tobacco industry.
It is well known that plasmonic nanostructures are capable of harvesting light and concentrating it in the near field. This special behavior results from the collective oscillation of the conduction electrons in a metallic nanostructure, and has enabled a plethora of exciting applications such as plasmon-enhanced solar cells, photonic circuits, superlenses, chemical and biological sensing, and the detection of single molecules. Underlying many of these processes is the ability of plasmon excitation to greatly enhance electromagnetic fields at the particle surface. The Camden group is working to develop new applications of plasmonic nanostructures and to understand fundamental features of the molecule-plasmon couplings underlying these applications. Our current research efforts include: (1) Understanding the flow of plasmonic energy from nanoparticles at interfaces and into molecules, (2) Development of fast, portable, and cost-effective analytical methods for small molecules based on SERS, and (3) Exploration of surface-enhanced nonlinear spectroscopy, and (4) Direct imaging of plasmon-enhanced fields using electron microscopy.
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