An effect of extra compactified dimensions of space in the molecule $$\hbox {NO}_{{2}}$$

The theory of large extra compactified dimensions of space (ADD-model) predicts that gravity may become strong in a compactification space of the size of a molecule and may affect the vibrational motion of a molecule. In triatomic molecules like $$\hbox {NO}_{{2}}$$ NO 2 nuclear dynamics is strongly coupled to electronic dynamics at the intersection of electronic states (conical intersection). We discuss experimental results on $$\hbox {NO}_{{2}}$$ NO 2 which reveal that the collision-free molecule optically excited into a symmetric stretch vibration mode of an electronic state with conical intersection undergoes an irreversible non-radiative transition into an asymmetric stretch vibration mode in combination with a change of the electronic state. We suggest ascribing this irreversible non-radiative transition to a gravitational perturbation on the vibrational motion in $$\hbox {NO}_{{2}}$$ NO 2 . This gravitational perturbation deactivates the upper state of the optical transition. The width of the absorption line is given by the characteristic time of the gravitational perturbation and not by the radiative lifetime of the excited molecular state. Graphical abstract

A First Step towards Determining the Ionic Content in Water with an Integrated Optofluidic Chip Based on Near-Infrared Absorption Spectroscopy

In this work, we present a feasibility study of integrated optofluidic chips to measure the ionic content in water using differential absorption spectroscopy. The second overtone of the OH-stretch vibration of water is used as indicator for both the type and concentration of the dissolved ions. The optofluidic chips are based on silicon nitride (TripleX) containing Mach–Zehnder interferometers (MZI) with two 5 cm sensing paths for the sample and reference arms, respectively. Simulations show that, theoretically, the determination of both the type and concentration of a mixture of four electrolytes is possible with the techniques presented. However, the performance of the chips deviated from the expected results due to the insufficient reproducibility and precision in the fabrication process. Therefore, at this early stage, the chips presented here could only determine the ion concentration, but not differentiate between the different ion types. Still, this work represents the first steps towards the realization of an online and real-time sensor of ionic content in water.

Solvation effects on wavenumbers and absorption intensities of the OH-stretch vibration in phenolic compounds – electrical- and mechanical anharmonicity via a combined DFT/Numerov approach

A previously measured oscillatory intensity pattern in phenolic compounds between different solvents was successfully reproduced for the first time, employing modern grid-based methods to solve the time-independent vibrational Schrödinger equation.

Removal of Procion Red MX- 5B from aqueous solution by adsorption on Parkia speciosa (stink bean) peel powder

The potential of Parkia speciosa peel (SBP) for removal of procion red mx-5B (PR) through the adsorption process was investigated. PR is a type of azo dye which is toxic to the environment especially in water. Sustainable adsorbents such as agricultural wastes have been promising to reduce the amount of pollution in wastewater due to their accessibility and more economic. The batch study was performed to examine the influence of varies exploratory conditions by fluctuating the dosage, adsorption time, and initial concentration. The main functional groups involved in the dye removal were analysed by Fourier transform infrared spectrometry (FTIR). The isotherm data were examined by the Langmuir, Freundlich and Temkin models. The result showed the equilibrium studies were perfectly associated by the Freundlich isotherm with R2= 0.9993, 0.9786 and 0.9728 for 1, 3 and 5 g of adsorbent dosage that corresponded with pseudo-second-order at a rate constant of 1x10-3/min. The FTIR spectrum of SBP after adsorption showed that changing of the functional groups of PR was presented by the stretch vibration of amine N-H and aromatic C=C, stretching vibrations for azo compound N=N. The remarkable data attained that the stink bean peel can be used as an alternative biosorbent for the removal of organic pollutants including the textile effluent industry.

Function Groups Analysis of Wood-Plastic Composite with Plasctic Waste and Pelawan’s Wood Sawdust (Tristaniopsis merguensis)

One of the efforts in tackling the increasingly large amount of plastic waste is to synthesize composite material from plastic waste with Pelawan’s wood sawdust (Tristaniopsis merguensis) as a raw material for the uphold of pepper plants. Pelawan is one of the endemic plants in the Bangka Belitung Islands Province. The characteristic observed in this study is the functional group of plastic waste composites with Pelawan’s wood sawdust, which was obtained from FTIR analysis. The method used in this study is to mix plastic waste and wood dust against contraper with variation ratio (wt / wt). The results of this FTIR show that there is an effect of the ratio of the amount of plastic waste and wood dust against the intensity of IR absorption. Based on IR data, the presence of absorption peak of FTIR spectrum at wave number 3327 cm-1 and widening of absorption in the region of wave number 3000-3550 cm-1 indicates the presence of O-H functional groups. The absorption band of the O-H vibrations is due to the presence of water molecules found in cellulose contained in the Pelawan’s wood sawdust. The absorption peak at wave number 1737 cm-1 indicates the existence of strain vibrations from the functional group C=O. While the absorption peak at wave number 1300-1000 cm-1 indicates the existence of stretch vibration from C-O. Therefore, the absorption tapes indicate the presence of cellulose originating from Pelawan’s wood sawdust which has been bound to plastic.