The Fourier transform infrared spectra of the thin layers of 2-methyl-4-nitroaniline (MNA) and its deuterated analog were recorded in the 500-4000 cm(-1) region in the 10-300 K temperature range. Activation energies of the -CH(3), -NH(2), and -NO(2) groups reorientations were estimated. The (1)H-NMR spin-lattice relaxation time, T(1), and the second moment of (1)H-NMR resonance line, M(2), measured in the 80-298 K temperature range, were used to determine the parameters of the -CH(3) group motion. The experimental potential barriers for the amine, nitro, and methyl group reorientations are considered in the context of strengths of the N-H([ellipsis (horizontal)])O, C-H([ellipsis (horizontal)])O intermolecular hydrogen bonds, and other short contacts, recognized recently [U. Okwieka et al., J. Raman Spectrosc. 39, 849 (2008)], and they agree with the barriers calculated by quantum chemical methods. The dynamical disorder found in the MNA crystal in the large temperature range seems to be important from the point of view of its nonlinear optical and other properties.

This article presents the developed methodology of classifying and evaluating the causes of accidents involving construction scaffolding. This methodology allows the causes of accidents to be identified, classified into generic groups, and also allows the importance of individual causes in their generic groups to be assessed. For the classification of causes, the Technical-Organizational-Human (TOH) method was used. Its assumption is the division of causes into technical (T), organizational (O), and human (H) ones. Pareto-Lorenz analysis and ABC classification were used to identify the most important causes. The developed methodology was used to analyze and assess the causes of accidents that involve construction scaffolding using the data of accidents that occurred in Poland as an example. The use of the proposed methodology in different countries will enable the results of the conducted studies and analysis to be compared, and conclusions that would be of a great importance in accident prevention to be drawn.

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Polarized FT-IR, Raman, neutron scattering (IINS), and UV-Vis-NIR spectra of 2-methyl-4-nitroaniline (MNA) crystal plates, powder, and solutions were measured in the 10-50 000 cm −1 range. The FT-IR spectrum of deuterated MNA (DMNA) in KBr pellet, the Raman spectrum of the DMNA powder as well as the EPR spectrum of the MNA powder were also recorded. Complete assignments of bands to normal vibrations have been proposed. Density functional theory (DFT) calculations of wavenumbers and potential energy distribution (PED) have been performed to strengthen the assignments. The analysis of vibrational and electronic spectra has revealed vibronic couplings in MNA molecules in solutions and in crystals. In the polarized FT-IR spectra of the crystal five unusually large bands are observed in MIR and NIR regions. Their origin is discussed in terms of N-H· · ·O, C-H· · ·O, C-H· · ·H-N hydrogen bonds, intermolecular charge transfers, electrostatic interactions, and ion radicals formation in the crystal. The role of a methyl group introduction to 4-nitroaniline is analyzed. The crystal structure of MNA at the room temperature was re-investigated.

The article presents an analysis and evaluation of the accident rate in selected European Union countries. On the basis of available statistical data, the analysis of accidents in various sectors of the European Union economy was carried out. Afterwards, a ranking of countries regarding accidents in the construction industry was developed.For the selected representative countries, analysis of changes in the indicators which characterize the accident rate during the period between 2008 and 2012 was carried out. Conclusions resulting from the conducted research were formulated.

Appropriate planning and effective monitoring of the execution of construction projects is important with regard to their successful sustainment of implementation. Time and cost are key elements that determine the success or failure of construction projects. The obtaining of a rational S-curve course before the start of a construction project that reflects reality is important for all the participants involved in implementing an investment task. The article proposes an original methodology for planning the course of the cumulative cost curve in construction projects. It uses a method of shaping the S-curve, which is well-known in both literature and practical approaches. On the basis of the authors' own research carried out in a homogeneous research group of hotel facilities, the areas of the curve for the correct planning of costs in construction projects were designated, which determine the boundaries of the predicted costs accumulated over time. The data for the development of the authors' research methodology is the result of the authors' own experience and professional work. The authors carried out Bank Investment Supervision in the years 2006-2019 on behalf of the banks that grant investment loans for non-public contracts. Knowing the total cost and duration of the planned construction project, which were determined on the basis of project documentation, cost estimates, and also their own database regarding planned and completed deadlines and budgets of similar investments, 6th degree polynomials of the real costs of the construction works were determined. This approach enabled the correct planning of costs over time and the determination of planned monthly amounts of construction works to be executed.

Polarized Fourier transform-infrared (FT-IR) reflectance spectra and powder Raman spectra have been measured for 1,3-dinitrobenzene crystal in order to revise the assignments of bands by means of the oriented gas model reinforced with quantum chemical [density functional theory (DFT)] calculations. Longitudinal optical/transverse optical (LO-TO) splitting of some bands is observed indicating medium strong, long-range, dipole-dipole interactions. The analysis of overtones in the polarized FT-NIR spectra has allowed us to estimate the anharmonicity of vibrations in the crystal. The molecular motions of the nitro groups are analyzed on the basis of temperature-dependent polycrystalline IR spectra. Based on the values of the energy difference ( ν el ) between the forbidden A 1g →B 2u transition in the benzene molecule in the gas phase and the first electronic transition in 1,3-dinitrobenzene, it has been concluded that the intermolecular interactions are medium strong. The nitro group interactions are proposed to play the main role in the optical nonlinearity.

Defining the basic determinants of the level of reliability with regards to the use of residential buildings and determining the function of the intensity of their characteristic defects are important issues concerning renovation strategy. The distribution of the exploitation time of residential buildings, the function of their reliability, and the distribution of the defect intensity of examined buildings are interdependent terms. Therefore, it can be assumed that the defect intensity of an object will be higher with an increase in its exploitation time. However, it is neither an increase reflecting the length of the building’s service life nor the value directly proportional to its age. The article presents a model and method of testing the defects and reliability of a representative group of traditional downtown residential buildings, which were erected in Wroclaw, Poland at the turn of the 19th and 20th centuries. A basic conclusion was drawn regarding the mechanism of damage of residential buildings: for the period of using the facility, in which the time of correct operation until failure has an exponential distribution, the average remaining time of failure-free operation is unchanged at any time. It was confirmed that the tested residential buildings, after a certain period of failure-free operation, fulfil their functions, just like new buildings. The optimal moment of renovation occurs after the end of the second period of operation, before the period of rapid wear. The study of the course of the damage intensity function over time reflects the wear process of a residential building in a representative sample of downtown residential buildings that were erected using traditional methods. Defining the average duration of the correct failure-free operation of an object by the reliability function, which determines the probability with which the correct operation time of an object will be longer than its age, has a practical application in the exploitation of a residential building and its components.