The drainage consolidation method has been efficiently used to deal with soft ground improvement. Nowadays, it has been suggested to use a new sand soil which is a composite of sand and recycled glass waste. The permeability performance of glass-sand soil was explored to judge the feasibility of glass-sand soil backfilled in the drainage consolidation of sand-drained ground. For comparison purposes, different mix proportions of recycled glass waste, fineness modulus, and glass particle size were analyzed to certify the impact on the permeability coefficient and the degree of consolidation. The numerical results show that adding a proper amount of recycled glass waste could promote the permeability performance of glass-sand soil, and the glasssand soil drain could be consolidated more quickly than a sand drain. Experiments showed that glass-sand soil with the a 20% mix of recycled glass waste reveals the optimum performance of permeability.

In the presented work, the author introduces the ballistic energy absorbed by the shield m_pV²_BL/2 to elaborate the results of firing on homogeneous plates and multi – layered constructional shields. The introduced criterion V²_BL is used to determine ballistic thickness h_BL and ballistic velocity V_BL under normal firing 7.62 mm ŁPS bullets.

The experimental tests were performed on an unified test stand to investigate ballistic resistance of materials in field conditions. The stand was developed at the Naval University of Gdynia and then patented. The design of this test stand was based on the construction of ballistic pendulum arranged for measuring: the impact forces, the turn angle of ballistic pendulum φ, initial and residual velocities of the bullet. All the measurement data were transmitted to a digital oscilloscope and personal computer. The energy absorbed by the shield was subject to further analysis of V²_BL[R] according to Recht’s and Ipson’s method and of V²_BL[Z] according to author’s method. The verification of the above-mentioned dependences was based on the results of the tests. The ballistic velocities V_BL[R] and V_BL[R] of the steel and steel – aluminium alloy shields with air interlayer thicknesses of 0, 6, 12 mm were approximately equal, however, they were quite different for aluminium alloy multi – layered shields, according to the results of firing 7.62 mm ŁPS bullets. These properties were confirmed by the average mass coefficients α²_s and average effectiveness coefficients β_s of the V²_BL for the tested methods.

Liquid forging alias squeeze casting gives the combined advantage of casting and forging. Optimum process parameters are important to get a cost-efficient process. In this study, four materials have been identified, which are extensively used in industries. These materials are commercially pure Al and three Al-alloys namely, 2124, 2218 and 6063. The pouring temperature and the mold temperature is maintained at 700oC and 250oC respectively. The materials were developed at seven pressure variations from 0 to 150 MPa. The effect of the pressure on the microstructures, porosity, and hardness has been reported. The coefficient of solubility is estimated for all materials and a polynomial relationship is found to be the best fit with the applied pressure. The pressure of 100 MPa gives better increment in hardness. The melting point and the freezing coefficient of the materials under study have been determined. A linear relationship between the pressure and the freezing time is deduced. It is observed that the solubility and the freezing coefficients depend on the pressure as well, in addition to the composition and temperature.

The article presents the method to assess the diffusion coefficient D in the sub-layer of intermetallic phases formed during hot-dip

galvanizing “Armco” iron and ductile cast iron EN-GJS-500-7. Hot-dip galvanizing is one of the most popular forms of long-term

protection of Fe-C alloys against corrosion. The process for producing a protective layer of sufficient quality is closely related to diffusion

of atoms of zinc and iron. The simulation consist in performed a hot-dip galvanizing in laboratory condition above Fe-C alloys, in the

Department of Engineering of Cast Alloys and Composites. Galvanizing time ranged from 15 to 300 seconds. Then metallographic

specimens were prepared, intermetallic layers were measured and diffusion coefficient (D) were calculated. It was found that the diffusion

coefficient obtained during hot-dip galvanizing “Armco” iron and zinc is about two orders of magnitude less than the coefficient obtained

on ductile cast iron EN-GJS-500-7.

The purpose of this study is to find the value of the discharge coefficient (Cd) on a sieve with a circular perforated plate so that it can be used for application in the field. The method used is to make a physical model test of the screen weir in the laboratory with a width of 40 cm and a length of 797 cm, then the screen is made variations in the diameter of the hole 6, 8, 10 and 12 mm, flowrate Q = 453–4 481 cm3∙s–1 and the slope of the screen θ = 20–45°. The result was quite ef-fective, the sediment did not enter above the screen and did not clog the screen even the catch was quite good about 80% of the screen rods. The discharge coefficient (Cd) is directly proportional to the square value of the number Froude (Fr), the slope of the screen (θ) and the ratio of distance, diameter of the screen (a:d) and inversely proportional to the value of the specific energy square (E). From modelling the average value of the discharge coefficient (Cd) between 0.1–2.75 with NSE = 0.71, MAE = 0 and RMSE = 0.12.

The paper is dedicated to the discussion of elastic coefficients of wood. Parameters for wood presented in the literature are critically evaluated and discussed. The orthotropic mathematical model, with nine different elastic parameters, is one of the most often used models of wood. However, mathematical limitations on these parameters for the correct model are not well known. Based on these limitations, the verification of orthotropic elastic parameters for different species of wood is presented. The analysis shows that the published data are often unclear and sometimes wrong. The attempt to relate experimental results to the mean values specified in the standards is the second aspect considered in this paper. The designer, a user of these standards, should have clear information that the given parameters are specified for specific mathematical model and species of wood. This paper attempts to propose such a classification.

The frictional resistance coefficient of ventilation of a roadway in a coal mine is a very important technical parameter in the design and renovation of mine ventilation. Calculations based on empirical formulae and field tests to calculate the resistance coefficient have limitations. An inversion method to calculate the mine ventilation resistance coefficient by using a few representative data of air flows and node pressures is proposed in this study. The mathematical model of the inversion method is developed based on the principle of least squares. The measured pressure and the calculated pressure deviation along with the measured flow and the calculated flow deviation are considered while defining the objective function, which also includes the node pressure, the air flow, and the ventilation resistance coefficient range constraints. The ventilation resistance coefficient inversion problem was converted to a nonlinear optimisation problem through the development of the model. A genetic algorithm (GA) was adopted to solve the ventilation resistance coefficient inversion problem. The GA was improved to enhance the global and the local search abilities of the algorithm for the ventilation resistance coefficient inversion problem.

The basic tests that allow the mechanical properties of grained material to be evaluated are tests of an aggregate’s resistance to crushing - the Los Angeles coefficient, and resistance to abrasion - the micro-Deval coefficient. These parameters primarily depend on the physical and mechanical properties of the raw material from which they are produced. The available literature widely describes the relationship between these parameters and bulk density, porosity, ultrasonic wave velocity, compression strength, tensile strength and point strength. This paper presents the relationship between the mechanical properties of aggregates and their geometrical properties. The analysis was carried out for the relationship between the Los Angeles and micro- Deval coefficients and the flatness and shape indices. As a result of the conducted considerations, the influence of the aggregate assortment on the analysed coefficients was also noted. All of the tests were carried out for aggregates (arch stones and mixtures) produced from sandstones from the Magura, Cergo and Krosno layers.

The paper presents the solution to a problem of determining the heat flux density and the heat transfer coefficient, on the basis of temperature measurement at three locations in the flat sensor, with the assumption that the heat conductivity of the sensor material is temperature dependent. Three different methods for determining the heat flux and heat transfer coefficient, with their practical applications, are presented. The uncertainties in the determined values are also estimated.