At the time when economy is growing, there is strong competition in the market, and customers have increasingly higher expectations as regards quality of service and products. Under such conditions, ...organizations need to improve. One of the areas of improvement for an organization is to research the level of customer satisfaction. The article presents results of customer satisfaction surveys conducted by the Servqual method in a pharmaceutical service company. Use of this method allowed to improve the services provided by that pharmaceutical wholesaler, identify areas that need to be improved as soon as possible in order to improve the level of service provided.
Liquid biofuels for compression ignition engines are often based on vegetable oils. In order to be used in compression ignition engine the vegetable oils have to be processed because of their high ...viscosity or it is also possible to use vegetable oils in fuel blends. In order to decrease the viscosity of the fuel blends containing crude vegetable oil the alcohol-based fuel admixtures can be used. The paper describes the effect of rapeseed oil–diesel fuel–n-butanol blends on combustion characteristics and solid particles production of turbocharged compression ignition engine. The 10% and 20% concentrations of n-butanol in the fuel blend were measured and analysed. The engine Zetor 1204, located in tractor Zetor Forterra 8641 with the power of 60kW and direct injection was used for the measurement. The engine was loaded through power take off shaft of the tractor using mobile dynamometer MAHA ZW500. The measurement was carried out in stabilized conditions at 20%, 60% and 100% engine load. The engine speed was kept at 1950 rpm. Tested fuel blends showed lower production of solid particles than diesel fuel and lower peak cylinder pressure and with increasing concentration of n-butanol in the fuel blend the ignition delay was prolonged and premixed phase of combustion was increased.
This article deals with the influence of some cutting parameters (geometry of cutting edge, wood species, and circular saw type) and cutting conditions on the wood crosscutting process carried out ...with circular saws. The establishment of torque values and feeding power for the crosswise wood cutting process has significant implications for designers of crosscutting lines. The conditions of the experiments are similar to the working conditions of real machines, and the results of individual experiments can be compared with the results obtained via similar experimental workstations. Knowledge of the wood crosscutting process, as well as the choice of suitable cutting conditions and tools could decrease wood production costs and save energy. Changing circular saw type was found to have the biggest influence on cutting power of all factors tested.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The research presented supported a comprehensive assessment of the condition of real oil samples of the HM quality class and VG 46 viscosity grade as functions of oil usage time in the hydraulic ...system of two round timber sorting and transport carriages (RSTW
and RSTW
) Baljer & Zembrod intended for handling wood logs by following the degradation and concentration of abrasive metals in the oil. The oil data were collected every Δ = 500 operating hours during one year by off-line monitoring of hydraulic oil. Measured values were compared to the acceptability limits. Multivariate associations were analysed using a principal component analysis (PCA; Statistica 12.0) to describe the patterns of co-variation among the examined traits. Based on the data obtained, it was observed that the oil in RSTW
was more oxidatively stressed in contrast to the oil in RSTW
despite it being subjected to an excessive wear mode.
Chainsaw operation is associated with several hazards, including exposure to wood dust, a risk factor which requires serious attention due to health impacts such as respiratory disease. This study ...aims to investigate the effect of saw chain type and wood species on the mass concentration of airborne wood dust during chainsaw cross-cutting operations. Real-time inhalable and respirable dust measurements in the breathing zone of the chainsaw operator were carried out using a desktop aerosol monitor. Three types of cutter shape (semi chisel, full chisel, and chamfer chisel) and four types of wood species (oak, beech, spruce, and fir) were used in the experiments. The split-plot ANOVA results showed that both respirable and inhalable mass concentrations of wood dust were affected exclusively by wood species. No statistically significant differences were found among particular levels of cutter shape. The highest average mass concentrations of airborne dust were generated by the combination of oak wood and a full chisel cutter.
Viscosity is considered to be a key factor in the quality of lubrication by oil and engine manufacturers and is therefore one of the most monitored parameters of lubricants. FTIR (Fourier-transform ...infrared) spectrometry in combination with Partial Least Squares (PLS) and Principal Component Regression (PCR) was therefore proposed and tested as an alternative to the standardized method for determining the kinematic viscosity at 100 °C with an Ubbelohde capillary viscometer (CSN EN ISO 3104) of worn-out motor oil grade SAE 15W-40. The FTIR-PLS model in the spectral region of 1750–650 cm−1 with modification of the spectra by the second derivative proved to be the most suitable. A significant dependence of R = 0.95 was achieved between the viscosity values of 190 samples of worn-out motor oils, which were determined by a standardized laboratory method, and the values predicted by the FTIR-PLS model. The Root Mean Square Error of Calibration (RMSEC) parameter reached 0.148 mm2s−1 and the Root Mean Square Error of Prediction (RMSEP) parameter reached 0.190 mm2s−1. The proposed method for determining the kinematic viscosity at 100 °C by the FTIR-PLS model is faster compared to the determination according to the CSN EN ISO 3104 standard, requires a smaller amount of oil sample for analysis and produces less waste chemicals.
Biomass energy for heating is going to be part of the spectrum of renewable energy sources. However, biomass combustion produces emissions of various pollutants with negative effects at both local ...and global scales. To reduce some of the locally important pollutant load, thermally treated biomass fuels may offer a partial solution. In this study, two biomass feedstocks, i.e., spruce chips and rapeseed straw, were thermally treated at 300 °C to produce biochars. Subsequently, both original materials and biochars were burned in a 25 kW retort combustion device. In both cases, the biochar showed lower emissions of carbon monoxide and nitrogen oxides, usually almost across the whole range of tested combustion conditions. In total, for the emission production per unit of net calorific value, the spruce biochar showed reductions in CO and NOx productions of 10.8% and 14.5%, respectively. More importantly, in rapeseed straw biochar, the difference was more pronounced. The total production was reduced by 28% and 42%, again in CO and NOx emissions, respectively.
The contribution brings the evaluation of selected materials regarding wear resistance under conditions of two experiments. The following materials had been chosen for these experiments: steel E295, ...steel C 45 after heat treatment, steel C 45 after quenching and steel 16MnCr5 after carburizing and quenching. The experiment was performed on a test device belonging to the category of “pin – disk“ test devices. The resistance of selected materials was evaluated regarding energy consumption, and it was compared to sizes of weight loss. It was observed that the material C 45 after heat treatment reached the highest values of wear resistance in conditions of adhesive wear without lubrication. The material 16MnCr5 indicated the best results in conditions of abrasive wear.
Condition monitoring and fault diagnosis of engineering systems are critical for the stable and reliable operation in various areas as mobile technology (primarily agricultural, forestry, mining and ...construction machinery), railways, airlines and large fleets. Thus, to achieve a satisfactory level of reliability for the life of a machine, proactive maintenance strategy is the only key. This means that the application of classical reliability methods suitable for components with sudden failures can be complemented by technical diagnostic methods which have the potential to provide the information about the system condition. In this article we focus on the diagnostic signal related to the used oil – tribodiagnostic measures and is an interesting theoretical item related to the evaluation of the quality of lubricants in the aspect of operation. This is because the oil is in direct contact with single parts of the assessed technical systems. Results tests were reviewed and derived from various parameters of lubricants and their limits that highlight the condition and state of the lubricants under varying categories which include, physiochemical, elemental (wear), contamination and additive analysis.
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