Experimental Methods for Measuring Optical Rotatory Dispersion:Survey and Outlook

The measurement of optical rotation (OR) and optical rotatory dispersion has been finding renewed interest for some years, because of advancement in computational methods and in the performance of new experiments. Here, we shortly review the traditional and most-used experimental methods. We define and discuss the two main types of approaches in measuring OR: the intensity method and the optical null method. We report on some new results obtained by redesigning experiments based on the first approach, by adapting nonsophisticated hardware to current circular dichroism instrumentation

Dipole and rotational strengths for overtone transitions of a C2-symmetry HCCH molecular fragment using Van Vleck perturbation theory

Contact transformation theory up to second order is employed to treat CH-stretching overtone transitions and to calculate dipole and rotational strengths. A general Hamiltonian describing two interacting CH-stretching oscillators is considered, and the Darling–Dennison resonance is appropriately taken into account. The two CH bonds are supposed to be dissymmetrically disposed, so as to represent a chiral HCCH fragment, endowed with C2 symmetry. Analytical expressions of transition moments and dipole and rotational strengths are given in the hypothesis of general electric and magnetic dipole moments with quadratic dependence on coordinates and momenta. Dipole and rotational strengths are then calculated together with frequencies for the fundamental and first three overtone regions in the simplifying hypothesis of the valence optical approach on the coupled-oscillator framework. Simplified analytical expressions thereof in the relevant parameters are presented

Motivation and personality traits for choosing religious tourism. A research on the case of Medjugorje.

Religion has long been a primary motivation for journeys and it is considered the oldest non-economic reason for travelling. The purpose of this paper is to investigate the reasons tourists choose to travel to sacred sites, with the specific aim of discovering relationships between personality traits and motivations for religious travel. Participating in the research were 679 Italian travellers to Medjugorje sanctuary, who completed the travel motivation scale and big five questionnaire. The results show that motivation is focused prevalently on the need for discovery in men and socialisation in women. Multiple regression analyses demonstrated that personality traits are predictive of motivation factors differently for males and females

Radiation and magnetic field effects on new semiconductor power devices for HL-LHC experiments

The radiation hardness of commercial Silicon Carbide and Gallium Nitride power MOSFETs is presented in this paper, for Total Ionizing Dose effects and Single Event Effects, under gamma, neutrons, protons and heavy ions. Similar tests are discussed for commercial DC-DC converters, also tested in operation under magnetic field

Evolution of the electronic structure across the filling-control and bandwidth-control metal-insulator transitions in pyrochlore-type Ru oxides

We have performed photoemission and soft x-ray absorption studies of pyrochlore-type Ru oxides, namely, the filling-control system Sm$_{2-x}$Ca$_x$Ru$_2$O$_7$ and the bandwidth-control system Sm$_{2-x}$Bi$_x$Ru$_2$O$_7$, which show insulator-to-metal transition with increasing Ca and Bi concentration, respectively. Core levels and the O 2$p$ valence band in Sm$_{2-x}$Ca$_x$Ru$_2$O$_7$ show almost the same amount of monotonous upward energy shifts with Ca concentration, which indicates that the chemical potential is shifted downward due to hole doping. The Ru 4$d$ band in Sm$_{2-x}$Ca$_x$Ru$_2$O$_7$ is also shifted toward the Fermi level ($E_F$) with hole doping and the density of states (DOS) at $E_F$ increases. The core levels in Sm$_{2-x}$Bi$_x$Ru$_2$O$_7$, on the other hand, do not show clear energy shifts except for the Ru 3$d$ core level, whose line shape change also reflects the increase of metallic screening with Bi concentration. We observe pronounced spectral weight transfer from the incoherent to the coherent parts of the Ru 4d $t_{2g}$ band with Bi concentration, which is expected for a bandwidth-control Mott-Hubbard system. The increase of the DOS at $E_F$ is more abrupt in the bandwidth-control Sm$_{2-x}$Bi$_x$Ru$_2$O$_7$ than in the filling-control Sm$_{2-x}$Ca$_x$Ru$_2$O$_7$, in accordance with a recent theoretical prediction. Effects of charge transfer between the Bi 6$sp$ band and the Ru 4$d$ band are also discussed.Comment: 11 pages, 6 figure

Slowing the fast fashion industry: an all-round perspective

The fashion sector contributes significantly to global environmental pollution. Clothing manufacturing and transportation produce a large amount of greenhouse gas emissions. Recent research has shown that nowadays, the number of consumers that are more willing to pay higher prices for clothes with high sustainability content is growing. This paper provides a broad framework of current trends in the fashion, textile, and garment industry, highlighting circular and slow fashion values that companies and policymakers should address in the coming years to maintain their competitiveness in the market and promote sustainable development. The EU Strategy for Sustainable and Circular Textiles is expected to help fashion enterprises achieve more circular, sustainable, and resilient value chains. Notably, encouraging natural and recycled textiles, design for reuse and recycling, second-hand retail and repair, and product-as-a-service models, particularly for items with high turnover rates, have been highlighted as critical factors for reducing the fashion industry's environmental implications

A Vibrational Circular Dichroism Approach To The Determination Of The Absolute Configuration Of Flexible And Transparent Molecules: Fluorenone Ketals Of 1,N-Diols

The infrared absorption (IR) and vibrational circular dichroism (VCD) spectra for five ketal molecules, three of which obtained from 1,2-diols and two from 1,3-diols, were recorded in the mid-IR region. The spectra have been satisfactorily reproduced by DFT calculations, even with not too large wavefunction basis sets, especially due to the low number of conformers to be considered. The mobility of some moieties provides a recognizable signature. A characteristic couplet of VCD bands attributed to normal modes involving the methine and a phenyl ring bonded to the stereogenic carbon atom is evidenced for two ketals of the series as a signature of the absolute configuration; due comparison with existing literature is made. A relation is discussed of the present VCD data with the literature VCD data of simple alcohols and diols

Experimental and ab-initio calculated vcd spectra of the first OH-stretching overtone of (1R)-(-) and (1S)-(+)-endo-borneol

The near infrared (NIR) absorption and NIR-vibrational circular dichroism (NIR-VCD) spectra of dilute solutions of the two enantiomers of endo-borneol have been measured in the first OH-stretching overtone region (1600–1300 nm). By density functional theory (DFT) we calculate mechanical parameters, i.e. the harmonic mechanical frequency and the anharmonicity constant for the OH stretching, and anharmonic electrical parameters; i.e. the dependence on OH-bond length of atomic polar tensors and atomic axial tensors. We evaluate transition integrals for the calculations of rotational and dipole strengths by Morse anharmonic wavefunctions depending on mechanical harmonic frequencies and mechanical anharmonicity parameters that are calculated ab initio. Experimental and calculated spectra compare quite well and this fact allows us to associate differently signed NIR-VCD features with different conformational states of the OH-bond. Absorption features for the fundamental and for the second overtone of the OH stretching are also compared with experiment

Interleukin-18 mediates cardiac dysfunction induced by western diet independent of obesity and hyperglycemia in the mouse

Obesity and diabetes are independent risk factors for heart failure and are associated with the consumption of diet rich in saturated fat and sugar, Western diet (WD), known to induce cardiac dysfunction in the mouse through incompletely characterized inflammatory mechanisms. We hypothesized that the detrimental cardiac effects of WD are mediated by interleukin-18 (IL-18), pro-inflammatory cytokine linked to cardiac dysfunction. C57BL/6J wild-type male mice and IL-18 knockout male mice were fed high-saturated fat and high-sugar diet for 8 weeks. We measured food intake, body weight and fasting glycemia. We assessed left ventricular (LV) systolic and diastolic function by Doppler echocardiography and cardiac catheterization. In wild-type mice, WD induced a significant increase in isovolumetric relaxation time, myocardial performance index and left ventricular end-diastolic pressure, reflecting an impairment in diastolic function, paired with a mild reduction in LV ejection fraction. IL-18 KO mice had higher food intake and greater increase in body weight without significant differences in hyperglycemia. Despite displaying greater obesity, IL-18 knockout mice fed with WD for 8 weeks had preserved cardiac diastolic function and higher left ventricular ejection fraction. IL-18 mediates diet-induced cardiac dysfunction, independent of food intake and obesity, thus highlighting a disconnect between the metabolic and cardiac effects of IL-18

Deploying a Communicating Automatic Weather Station on an Alpine Glacier

The cost and effort of installing and maintaining an automatic weather station (AWS) on a glacier may be mitigated by the possibility of gathering sensor data in near real-time, and of controlling and programming the station remotely. In this paper we report our experience with upgrading an existing AWS, operating over an Italian glacier, from a mere datalogger into a networked sensing station. Design choices, energy constraints and power-aware programming of the station determined by harsh environment are discussed. Deployment operations and results are described. The upgraded AWS provides low-power connectivity from a remote location and is able to serve as a base station for a wireless sensor network working in the glacier