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In the lowland part of Croatia, heavy machinery such as forwarders is mainly used for the purpose of extracting wood from even-aged forest stands. According to the forest management plan, forwarders are used intensively in the winter period when the soil is mostly saturated with water and when their activity can cause significant damage to the soil. The aim of this study was to determine changes in soil characteristics as a consequence of the repeated passage of a loaded 8-wheel forwarder on silty clay loam type of soil. The research was conducted in an area where the forwarder usually works and in a way that did not significantly disrupt his normal workflow. The results indicate that during the study period the soil had a good bearing capacity and that the observed changes in soil characteristics (bulk density, total soil porosity, soil moisture, particle density, soil water retention capacity etc.) occurred as a result of breaking structural soil aggregates after soil compaction by multiple passes. Characteristic points (T) of equalized penetration curves indicate the compaction of the soil surface layer. Cone penetration index (CI) values did not show a proportional increase as the number of forwarder passes increased, although significant differences in their values with respect to the number of passes were found. Shear strength (τ) did not significantly increase with increasing the number of passes, but a statistically significant difference in the measured values was detected at the soil surface, which was not observed at a depth of 15 cm. Exceeding the rut depth limit of 10 cm occurred only after the 20th pass. Our results indicate that the soil at the harvesting site had a good bearing capacity during the study period.

Fuel consumption of forest machinery and vehicles depends mainly on terrain conditions, working methods, drivers’ skills, engine load under working conditions, engine speed, type and technical characteristics of the machine. In timber harvesting operations, fuel consumption is significant for both, economic (costs), and environmental issues (80-95% of exhaust emissions and soot particles are associated with fuel consumption). The objective of this study was to compare fuel consumption in two different forwarders and to analyse two different measuring devices for fuel consumption. Fuel consumption was measured on a 6-wheeled Valmet 840.2 forwarder and an 8-wheeled Valmet 860.4 during roundwood and energy wood extraction in winter period. A differential fuel flow meter and a fuel measuring probe were used for measuring fuel consumption as well as a Fleet Management System (FMS) for transmitting measured data. Fuel consumption was expressed in six different ways depending on the stage of the working cycle, time, travelled distance, load volume and load mass. Finally, both the advantages and disadvantages of the used fuel measuring devices were gained. The results indicated higher fuel consumption of the smaller Valmet 840.2 forwarder due to lower soil bearing capacity and longer extraction distances. For both forwarders, higher fuel consumption (expressed in l t-1 km-1) was observed while extracting energy wood due to its lower overall mass.

The problem of exposure to harmful vibrations in forestry arises with the use of the first chainsaws in logging and construction. Although working with chainsaws was many times faster, more productive, and physically less demanding than manual felling, chainsaws emitted large amounts of vibration and over time had a negative impact on the health of forest workers. White finger disease (Raynaud's syndrome) has become a real problem with great potential for reducing workers' working ability. Along with the use of chainsaws, some operations still require hand tools in forestry. The main theme of this paper is to compare daily vibration exposure in cleaning operations when operating a chainsaw and billhook. EU Directive 2002/44/ EC clearly establishes limit values for daily vibration exposure, A(8), which serve as a measure against excessive vibration exposure. In this paper, the A(8) values for working with a chainsaw and working with a billhook in cleaning are estimated. The timeshares of individual cleaning operations were obtained using time study methods on videos of effective work. The result of the time analysis indicates that the worker spends 46.7% of his time in cutting, while the rest of the time is spent in different ways of carrying a chainsaw. In working with the billhook, the worker makes an average of 27 cuts per minute. Vibration levels were recorded with a Brüel & Kjaer 4447 vibrometer and calculated according to ISO 5349 standards. A(8) values of 4.9 m/s2 on the right hand and 3.4 m/s2 on the left hand when operating the chainsaw were obtained, and 13.7 m/s2 on the right hand when operating the billhook. The results point to a serious misconception when organizing work and using human resources. The common belief that working with a billhook, to which workers with disabilities are mostly allocated, is "easier" than working with a chainsaw and can have serious health consequences for the health of workers. The results of this study indicate the direction in which the forestry profession should be guided in organizing cleaning operations that will comply with the applicable regulations for the protection of the health of workers. [ABSTRACT FROM AUTHOR]

Background: It has been argued that human ancestors evolved greater sensitivity to certain traits that signal dominance in potential leaders. From this perspective, modern voters still favor certain physical characteristics during political elections. Indeed, previous studies have shown that voters prefer dominant candidates, especially when primed with wartime scenarios, and with conservative voters being more likely to choose a dominant leader. Because facial width-to-height ratio (fWHR) was found to be positively associated with perceived dominance, we sought to investigate the effect of fWHR on leader preference by taking into an account voting context and voters' political ideology., Participants and Procedure: A total of 148 participants took part in two online experiments in which we manipulated standardized facial images to represent faces with low and high fWHR. Furthermore, we assessed participants' political ideology and asked them to rate the extent to which faces with low and high fWHR looked like leaders during wartime and peacetime scenarios., Results: Preference for leaders with high fWHR was positively related to participants' political ideology, but only in a wartime scenario, suggesting that the more conservative participants were, the higher was their preference for leaders with high fWHR. This is consistent with the notion that preferences for dominant-looking leaders vary as a function of the contextual (voting context) and individual differences (political ideology)., Conclusions: The present findings provide new evidence for the contribution of fWHR in leader preference and significantly adds to the results of previous research demonstrating the roles of voters' political ideology and politicians' physical characteristics in perceiving leadership abilities., (Copyright © Institute of Psychology, University of Gdansk.)

To identify the unknown values of the parameters of Burger's constitutive law, commonly used for the evaluation of the creep behavior of the soft soils, this paper demonstrates a procedure relying on the data obtained from multiple sensors, where each sensor is used to its best advantage. The geophysical, geotechnical, and unmanned aerial vehicle data are used for the development of a numerical model whose results feed into the custom-architecture neural network, which then provides information about on the complex relationships between the creep characteristics and soil displacements. By utilizing InSAR and GPS monitoring data, particle swarm algorithm identifies the most probable set of Burger's creep parameters, eventually providing a reliable estimation of the long-term behavior of soft soils. The validation of methodology is conducted for the Oostmolendijk embankment in the Netherlands, constructed on the soft clay and peat layers. The validation results show that the application of the proposed methodology, which relies on multisensor data, can overcome the high cost and long duration issues of laboratory tests for the determination of the creep parameters and can provide reliable estimates of the long-term behavior of geotechnical structures constructed on soft soils.

Biodiesel, which was earlier used only as an alternative fuel, is now an indispensable component of commercial diesel. Conventional production processes are unable to cope with the increasing demand for biodiesel, and therefore more and more work is being done to intensify the existing processes. The intensification of the biodiesel production process, taking into account the environmental and economic factors, is based on increasing productivity. One way to achieve that is by reducing the volume of production units. The application of the enzymatic reaction path, while reducing the volume of process equipment to the micro-level, has significantly magnified the productivity of the biodiesel production process, which is primarily due to better mass transfer in microsystems. Additional breakthrough is the use of deep eutectic solvents (DES) instead of buffers for enzyme stabilization. In this study, a lipase from Thermomyces lanuginosus (TlL) (both commercial and produced by solid-state fermentation) was used as a catalyst for biodiesel production. Edible and waste sunflower oil, as well as methanol, were used as substrates. The reaction mediums were buffer and DES. The transesterification reaction was carried out in a batch reactor and the emphasis was made on different microreactor configurations. The highest yield of 32% for residence time of only τ = 30 min was obtained in the microreactor system with an emulsion of waste oil and a commercial enzyme suspended in a buffer. This indicates that enzymatic transesterification could be a valuable reaction path for dealing with waste oils. Furthermore, biodiesel synthesis in DES showed somewhat lower yields, but by increasing the water content in the system, the reaction could prove much better results. In the end, the effects of reaction conditions on the volumetric productivity of the process were analyzed.

Grouted rock bolts represent one of the most used elements for rock mass stabilization and reinforcement and the grouting quality has a crucial role in the load transfer mechanism. At the same time, the grouting quality as well as the grouting procedures are the least controlled in practice. This paper deals with the non-destructive investigation of grouting percentage through an analysis of the rock bolt's natural frequencies after applying an artificial longitudinal impulse to its head by using a soft-steel hammer as a generator. A series of laboratory models, with different positions and percentages of the grouted section, simulating grouting defects, were tested. A comprehensive statistical analysis was conducted and a high correlation between the grouting percentage and the first three natural frequencies of rock bolt models has been established. After validation of FEM numerical models based on experimentally obtained values, a further analysis includes consideration of grout stiffness variation and its impact on natural frequencies of rock bolt.

Key regulators of the Wnt signalling, DVL1, DVL2 and DVL3, in astrocytomas of different malignancy grades were investigated. Markers for DVL1, DVL2 and DVL3 were used to detect microsatellite instability (MSI) and gross deletions (LOH), while immunohistochemistry and immunoreactivity score were used to determine the signal strengths of the three DVL proteins and transcription factors of the pathway, TCF1 and LEF1. Our findings demonstrated that MSI at all three DVL loci was constantly found across tumour grades with the highest number in grade II (P = 0.008). Collectively, LOHs were more frequent in high-grade tumours than in low grade ones. LOHs of DVL3 gene were significantly associated with grade IV tumours (P = 0.007). The results on protein expressions indicated that high-grade tumours expressed less DVL1 protein as compared with low grade ones. A significant negative correlation was established between DVL1 expression and malignancy grades (P < 0.001). The expression of DVL2 protein was found similar across grades, while DVL3 expression significantly increased with malignancy grades (P < 0.001). The signal strengths of expressed DVL1 and DVL3 were negatively correlated (P = 0.002). However, TCF1 and LEF1 were both significantly upregulated and increasing with astrocytoma grades (P = 0.001). A positive correlation was established between DVL3 and both TCF1 (P = 0.020) and LEF1 (P = 0.006) suggesting their joint involvement in malignant progression. Our findings suggest that DVL1 and DVL2 may be involved during early stages of the disease, while DVL3 may have a role in later phases and together with TCF1 and LEF1 promotes the activation of Wnt signalling., (© 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)