In solution, α-helices are stabilized at the termini by a variety of different capping interactions. Study of these interactions in the gas phase provides a unique means to explore the intrinsic properties that cause this stabilization. Evidence of helical and globular conformations is presented here for gas-phase, doubly charged peptides of sequence XAnK, wherein X is D, N, Q, or L. The relati...

Two-phase flow measurement has attracted a major interest in the past four decades due to its wide range of applications in industry. This paper introduces a new method to separate the gas phase from the liquid phase through a blind source separation algorithm, without a separate device, based on the assumption that the two phases are separated and their independence is reflected in the statist...

In this research, Quantum-mechanical calculations were performed at the HF method with the 6-31+G*basis set and at the B3LYP method with the 6-31+G* basis set in the gas phase and five solvents such as water, DMSO, methanol, ethanol and dichloromethane at six temperatures. According to these theoretical results of IR, we extracted thermo chemical parameters such as enthalpy (∆H Kcal/mol), Gibbs...

Lu Han and Muthanna H. Al-Dahhan A gaseous tracer technique and procedures were developed and implemented to measure the axial dispersion of gas phase in a slurry bubble column reactor using air-water-glass beads (100ìm). Residence time distribution curves were obtained by measuring the response of gaseous tracer pulse input. The gas phase axial dispersion coefficient, Dg, was determined from m...

The temperature dependence of the irreversible phase transition from a two-dimensional gas to an ordered zero-dimensional solid on the Si(111)-7 × 7 surface was studied using photoemission spectroscopy. With increasing Na coverage, the two-dimensional Na gas, which is a state of highly mobile Na atoms, undergoes a phase transition into ordered zero-dimensional magic nanoclusters at room tempera...

The synthesis of metallic nanoparticles is an active area of academic and, more significantly, applied research in nanotechnology. Several methods have been introduced for the synthesis of these materials. The techniques for synthesizing aluminum nanoparticles can be divided into solidphase, liquid-phase and gas-phase processes. The solid-phase techniques include mechanical ball milling and mec...

Complexes of cyclodextrins with amino acid analytes are produced in the gas phase and are ideal for the study of molecular recognition. In this Account, we discuss the evidence for the presence of gas-phase inclusion complexes and the nature of the interaction. The use of cyclodextrins as chiral selectors in gas-phase guest-exchange reactions is illustrated, and the nature of the enantioselecti...

Uptake kinetics of gas phase nitrous acid (HONO) by a pH-controlled aqueous solution was investigated by using a wetted wall flow tube. The gas phase concentration of HONO after exposure to the aqueous solution was measured selectively by the chemical ionization mass spectrometer in a high sensitive manner. The uptake rate of the gaseous HONO was found to depend on the pH of the solution. For t...