The use of image analysis to study the effect of moisture content on the physical properties of grains.

Designing machines and equipment for post-harvest operations of agricultural products requires information about their physical properties. The aim of the work was to evaluate the possibility of introducing a new approach to predict the moisture content in bean and corn seeds based on measuring their dimensions using image analysis using artificial neural networks (ANN). Experimental tests were carried out at three levels of wet basis moisture content of seeds: 9, 13 and 17%. The analysis of the results showed a direct relationship between the wet basis moisture content and the main dimensions of the seeds. Based on the statistical analysis of the seed material, it was shown that the characteristics examined have a normal or close to normal distribution, and the seed material used in the investigation is representative. Furthermore, the use of artificial neural networks to predict the wet basis moisture content of seeds based on changes in their dimensions has an efficiency of 82%. The results obtained from the method used in this work are very promising for predicting the moisture content.

The use of a Mamdani-type fuzzy model for assessing the performance of a boom stabilization systems in a field sprayer.

Fuzzy logic models are increasingly used to control simple and complex devices, as well as entire operating systems. In this study, a fuzzy logic model was applied to assess the performance a boom stabilization system in a field sprayer. The model was tested on a field sprayer with a trapezoid system for stabilizing the sprayer boom with a length of 21 m. Measuring cables for registering the displacement of the boom's terminal segments (right and left) in the vertical and horizontal plane were installed on the sprayer. The field sprayer was connected to a tractor. The model was based on two linguistic variables: "absolute displacement of the boom's terminal segments" and "boom stability index". It was assumed that the sprayer boom was stable when the displacement of the boom's terminal segments did not exceed 0.25% of boom length. The study demonstrated that the proposed model can be reliably used to assess boom stability in real time (during field operations). The time required to achieve boom stability was more than 2.5 times shorter in the vertical than in the horizontal plane, which can be attributed mainly to the structure of the stabilization system. The proposed model is universal, and it can be applied to evaluate other boom stabilization systems in field sprayers.

Effect of using deflector in the distributor head of a pneumatic seed drill on the oat seed sowing unevenness.

This paper presents an innovative solution for a distributor head equipped with a deflector (controlled plate)-intended to change the tilt angle (realignment) of the pneumatic seed drill distributor head cover. We compared two qualitative parameters of seed sowing, coefficient of variation and coefficient of lateral unevenness of seed sowing (δ). Values were obtained on the test stand with an innovative deflector built into the distributor head at three angles of inclination (0°, 5° and 10°). Statistical analyses revealed a significant effect of airflow velocity and deflector angle, which corrects the deviation from the vertical plane of the distributor head, on the uniformity of seed sowing. In addition, regression equations were determined to predict the quality of the seed sowing process. The developed and manufactured innovative distributor head with a deflector that tilts in two planes, designed to improve the distribution evenness of the air stream transporting seed to individual coulters in pneumatic seed drills, received a positive review. The use of a deflector with automatic control of its position angle, correcting the deviation of the distributor head from a vertical plane in pneumatic seed drills improves the uniformity of seeding. Therefore, it is reasonable to use this solution for new pneumatic seed drills and those in use on soils with different relief (undulating surface). Moreover, the solution fits in with modern agricultural manufacturing in accordance with the ideas of precision agriculture.

Direct Vertebral Rotation (DVR) Does Not Improve Clinical and Radiological Results Compared to Differential Rod Contouring (DRC) in Patients Treated Surgically for Idiopathic Scoliosis.

Direct vertebral rotation (DVR) is the most widespread method to correct axial vertebral rotation. Differential rod contouring (DRC) also includes derotation, but not to the same extent as DVR. DVR requires additional surgical effort with potential consequences, which are absent in DRC; moreover, the data concerning the clinical benefits of apical derotation are not convincing. In the present study, clinical and radiological outcomes were compared in patients who underwent surgery for adolescent idiopathic scoliosis (AIS), having DVR and DRC vs. DRC only. In total, 73 AIS patients with curves of 40-85°, consecutively operated on by one surgeon, participated in this study and were followed up over 2 years. Scores from the SRS-22 questionnaire were analysed, the angles of trunk rotation (ATR) were measured with an inclinometer and a radiographic assessment of coronal and sagittal spinal profiles was conducted. In 38 cases, only DRC was performed, and in 35 DRC was performed and followed by DVR; the groups did not differ from an epidemiological point of view. Total SRS-22 scores after 2 years were similar in both groups (4.23 (±0.33) in DRC vs. 4.06 (±0.33) in DRC/DVR, p = 0.1). In all components of SRS-22, the differences were minor, with p being way above 0.05. The mean ATR in the DRC/DVR group was slightly smaller (8 ± 4°) than that of the DRC group (10 ± 5°), p = 0.16. Radiographic analysis did not show significant differences. The coronal curve was corrected by 66 ± 12% for DRC and 63 ± 15% for DVR, p = 0.28. Thoracic kyphosis in the DRC/DVR group increased by 1°, whereas in the DRC group the average kyphosis increased by 5° with a p value of 0.07. The complication rates were similar in both groups. This investigation did not show any advantages of the combination of DRC and DVR in scoliosis correction over DRC only, both radiologically and clinically, yet it affected intraoperative parameters, extending the operation time with only a minor increase in blood loss.

Analysis of the physical properties of spindle seeds for seed sorting operations.

The relationships between the basic physical properties of seeds of selected spindle species were evaluated for the needs of seed sorting operations. Physical properties were measured in the seeds of five spindle species, and the presence of relationships between these attributes was determined in correlation and regression analyses. The average values of the evaluated parameters were determined in the following range: terminal velocity-from 9.2 to 10.3 m s-1, thickness-from 2.57 to 3.26 mm, width-from 2.87 to 3.74 mm, length-from 3.94 to 5.52 mm, angle of external friction-from 20.7° to 24.6°, mass-from 16.5 to 33.8 mg. Spindle seeds were arranged in the following ascending order based on their geometric mean diameter: winged spindle, Hamilton's spindle, large-winged spindle, broadleaf spindle and European spindle. Spindle seeds should be separated in a sieve equipped with at least two mesh screens with slotted apertures. Depending on the processed spindle species, aperture size should range from ≠ 2.7 to ≠ 3.5 mm in the top screen, and from ≠ 2.4 to ≠ 3.0 mm in the bottom screen.

The Effect of the Distribution Head Tilt and Diffuser Variants on the Evenness of Sowing Rye and Oat Seeds with a Pneumatic Seed Drill.

Due to the sustainable development of agriculture machines with large working widths of 4-6 m or even 9-12 m are increasingly often used for agrotechnical operations. The sowing machinery whose working widths are much bigger than the width of the seed box is equipped with a pneumatic system for transporting seeds from the seed box to coulters. One of the structural elements that affect the sowing accuracy in such seed drills is the distribution head with a diffuser. This article is about research on the influence of the distribution head deviation from the vertical position and constructional variants of the diffuser (the number of diffusion rings and the configuration of their position in the diffuser pipe, which is the distance between them) on the accuracy of distribution of a stream of rye and oat seeds (a seed-and-air stream), which differ in physical characteristics. The main elements, i.e., the innovative stream distributor in the head and the diffusion rings were made using an original design and the rapid prototyping method. The research proved that a change of 0-10° in the angle of the distribution head deviation from the vertical position significantly affected the sowing quality of oat seeds only. The position (density) of the diffusion rings in the lower section of the diffuser (near the supply elbow) was the most effective for both oat and rye seeds, where the average values of the coefficient of variation were 5.31% and 4.62%, respectively. The research results can be used to redesign the construction of the diffuser of the seed drill distribution head so as to reduce the resistance of transport of the seed-and-air mixture in order to improve seed sowing evenness.

Socioeconomic Determinants of the Anthropometric Characteristics and Motor Abilities of Polish Male University Students: A Cross-Sectional Study Conducted in 2000-2018.

Aim: The aim of this study was to determine the relationships between socioeconomic factors, anthropometric characteristics and motor abilities of male university students. Materials and Methods: The study was conducted from 2000 to 2018 on 2691 male university students aged 19.98 ± 1.05 years, who were randomly selected from students attending obligatory physical education (PE) classes. The participants' body mass and height were measured, and students participated in 13 motor ability tests that assessed their speed/agility, flexibility, strength and endurance abilities. Multiple independent samples were compared with the Kruskal-Wallis test or the mean-ranks post-hoc test when significant differences were observed in the participants' motor abilities. Results: Factors such as the place of permanent residence, students' monthly budget, and mother's and father's educational background, significantly (p < 0.05) influenced the body mass, BMI and motor abilities of first-year university students. The participants' motor abilities (speed/agility, flexibility-partly, strength, strength endurance, and endurance) were most frequently and most significantly determined by their monthly budgets, and were least frequently and least significantly determined by their place of permanent residence. Conclusions: The students' body height, BMI and motor abilities generally increased with a rise in population in the place of permanent residence, monthly budget, and the parents' educational attainment.

International Standards for the 3-Minute Burpee Test: High- Intensity Motor Performance.

The aim of this study was to develop international standards for evaluating strength endurance with the use of the 3-Minute Burpee Test. The results of 3862 women (Poland - 2502, Great Britain - 500, Hungary - 412, Serbia - 448) and 5971 men (Poland - 4517, Great Britain - 500, Hungary - 451, Serbia - 503) aged 18-25 (mean age of 20.36 ± 0.94 and 20.05 ± 1.25 y, respectively) were collated between 2004 and 2018. The students' strength endurance was evaluated in the 3-Minute Burpee Test. The results were expressed on a uniform scale with the 3-sigma rule which was used to develop the T-score scale for the 3-Minute Burpee Test. Men completed 56.69 cycles/3 min and women - 48.84/3 min on average. The best male participant completed 82 burpees, and the best female participant - 73 burpees. The majority of male and female participants (66.71% and 68.18%, respectively) were characterized by average strength endurance in the 3-Minute Burpee Test (range of scores: 47-66 and 37-60 cycles/3 min, respectively). Very good strength endurance (76-85 and 72-83 cycles/3 min, respectively) was noted in the smallest percentage of male and female participants (0.52% and 0.26%, respectively). Similar studies should be carried out in other countries and in different age groups to develop objective international classification standards for variously-aged individuals.

Modelling of the Temperature Difference Sensors to Control the Temperature Distribution in Processor Heat Sink.

This paper has three main purposes. The first is to investigate whether it is appropriate to use a planar thick-film thermoelectric sensor to monitor the temperature difference in a processor heat sink. The second is to compare the efficiency of two heat sink models. The third is to compare two kinds of sensors, differing in length. The model of the CPU heat sink sensor system was designed for numerical simulations. The relations between the CPU, heat sink, and the thermoelectric sensor were modelled because they are important for increasing the efficiency of fast processors without interfering with their internal structure. The heat sink was mounted on the top of the thermal model of a CPU (9.6 W). The plate fin and pin fin heat sinks were investigated. Two planar thermoelectric sensors were mounted parallel to the heat sink fins. These sensors monitored changes in the temperature difference between the CPU and the upper surface of the heat sink. The system was equipped with a cooling fan. Switching on the fan changed the thermal conditions (free or forced convection). The simulation results showed the temperature gradient appearing along the sensor for different heat sinks and under different thermal conditions. Comparison of the results obtained in the simulations of the CPU heat sink sensor systems proves that changes in the cooling conditions can cause a strong, step change in the response of the thermoelectric sensor. The results suggest that usage of the pin fin heat sink model is a better solution for free convection conditions. In the case of strong forced convection the heat sink type ceases to be significant.

Rapid continuous microwave-assisted synthesis of silver nanoparticles to achieve very high productivity and full yield: from mechanistic study to optimal fabrication strategy.

Systematic studies of silver nanoparticle synthesis in a continuous-flow single-mode microwave reactor using polyol process were performed, revealing that the synthesis is exceptionally effective to give very small metal particles at full reaction yield and very high productivity. Inlet concentration of silver nitrate or silver acetate, applied as metal precursors, varied between 10 and 50 mM, and flow rates ranged from 0.635 to 2.5 dm3/h, to give 3-24 s reaction time. Owing to its much higher reactivity, silver acetate was shown to be far superior substrate for the synthesis of small (10-20 nm) spherical silver nanoparticles within a few seconds. Its restricted solubility in ethylene glycol, applied as the solvent and reducing agent, appeared to be vital for effective separation of the stage of particle growth from its nucleation to enable rapid synthesis of small particles in a highly loaded system. This was not possible to obtain using silver nitrate. All the observations could perfectly be explained by a classical LaMer-Dinegar model of NPs' formation, but taking into account also nonisothermal character of the continuous-flow process and acetate dissolution in the reaction system. The performed studies indicate an optimal strategy for the high-yield fabrication of metal particles using polyol method.

Sauna-induced body mass loss in young sedentary women and men.

The aim of the study was to evaluate the relationship between body mass index (BMI) and body mass loss (BML) induced by thermal stress in a dry sauna. The study was conducted on a group of 674 sedentary students, 326 women and 348 men aged 19-20. The correlations between BMI scores and BML were determined. The subjects were placed in supine position in a dry sauna for two sessions of 10 minutes each with a 5-minute break. The influence of BMI on the amount of BML in the sauna was determined by nonlinear stepwise regression. The smallest BML was noted in underweight subjects; students with normal weight lost more weight, whereas the greatest BML was reported in overweight and obese subjects. Persons with a high BMI are at higher risk of dehydration, and they should pay particular attention to replenishing fluids during a visit to the sauna. The proposed equations for calculating BML based on a person's BMI can be useful in estimating the amount of fluids that should be replenished by both men and women during a visit to a dry sauna.

Development and validation of an HPLC method for the simultaneous analysis of 23 selected drugs belonging to different therapeutic groups in human urine samples.

We have developed and validated a new and reliable gradient reversed-phase high-performance liquid chromatography (RP-HPLC) method with a diode array detector (DAD) for the simultaneous separation and determination of 23 frequently prescribed selected drugs belonging to different therapeutic groups in human urine samples. For the drugs listed below, this method of analysis for human urine was also successfully applied to determine urine concentrations of these drugs in samples from treated patients: enalapril (ENA), paracetamol (PAR), sotalol (SOT), dipyrone (DIP), vancomycin (VAN), captopril (CAP), fluconazole (FLU), cefazolin (CEF), metoprolol (MET), aspirin (ASP), ticlopidine (TIC), prednisolone (PRE), propranolol (PRO), digoxin (DIG), sildenafil (SIL), furosemide (FUR), dexamethasone (DEX), carvedilol (CAR), ketoprofen (KET), nifedipine (NIF), terbinafine (TER), acenocoumarol (ACE) and spironolactone (SPI). Separation of the analytes was achieved by RP-HPLC-DAD with a mobile phase composed of acetonitrile, methanol and 0.05% trifluoroacetic acid in water using a gradient elution program. Good linear relationships over the investigated concentration ranges were observed with values of r2 higher than 0.998 for all of the drugs. The intra-day and inter-day precisions of this method were evaluated with RSD values less than 4.26 and 5.42%, respectively. The relative recoveries of the 23 investigated compounds ranged from 93.60 to 106.00% with RSD values less than 4.46%. An expanded uncertainty budget was constructed for all investigated drugs in human urine samples.

Determination of selected drugs in human urine by differential pulse voltammetry technique.

A new, simple and selective differential pulse voltammetry (DPV) method for the simultaneous determination of selected drugs in model solutions and spiked human urine samples with prior extraction was developed and validated. The objects of analysis were paracetamol, furosemide, dipyrone, cefazolin and dexamethasone belonging to four different therapeutic groups (antibiotics, analgesic, demulcent and diuretic). Analytical methods for the preparation of urine samples for voltammetric analysis (liquid-liquid extraction--LLE and solid-phase extraction--SPE) were worked out and optimized. Hanging mercury drop electrode (HMDE) and graphite electrode were used as working electrodes. Reference electrode was Ag|AgCl|KCl((sat.)), whereas auxiliary electrode--platinum electrode. The optimal conditions for quantitative determination were obtained in a Britton-Robinson (BR) buffer at pH 2.4. Quantification was performed by means of calibration curve and standard addition methods. The calibration curves of analysed drugs are linear within the range of concentration: 6.61-66.10, 6.05-54.42, 6.00-65.00, 4.20-33.58 and 0.51-3.06 microM for paracetamol, furosemide, dipyrone, cefazolin and dexamethasone, respectively. The levels of analysed compounds in human urine can be successfully determined using this developed method with no matrix effect.

Simultaneous determination of L-arginine and 12 molecules participating in its metabolic cycle by gradient RP-HPLC method: application to human urine samples.

We have developed and described a highly sensitive, accurate and precise reversed-phase high-performance liquid chromatography (RP-HPLC) method for the simultaneous determination of L-arginine and 12 molecules participating in its metabolic cycle in human urine samples. After pre-column derivatization with ortho-phthaldialdehyde (OPA) reagent containing 3-mercaptopropionic acid (3MPA), the fluorescent derivatives were separated by a gradient elution and detected by fluorescence measurement at 338 nm (excitation) and 455 nm (emission). L-Arginine (ARG) and its metabolites: L-glutamine (GLN), N(G)-hydroxy-L-arginine (NOHA), L-citrulline (CIT), N(G)-monomethyl-L-arginine (NMMA), L-homoarginine (HARG), asymmetric N(G),N(G)-dimethyl-L-arginine (ADMA), symmetric N(G),N(G')-dimethyl-L-arginine (SDMA), L-ornithine (ORN), putrescine (PUT), agmatine (AGM), spermidine (SPERMD) and spermine (SPERM) were extracted in a cation-exchange solid-phase extraction (SPE) column and after derivatization separated in a Purospher STAR RP-18e analytical column. The calibration curves of analysed compounds are linear within the range of concentration: 45-825, 0.2-15, 16-225, 12-285, 0.1-32, 15-235, 0.1-12, 0.1-12, 10-205, 0.02-12, 0.1-24, 0.01-10 and 0.01-8 nmol mL(-1) for GLN, NOHA, CIT, ARG, NMMA, HARG, ADMA, SDMA, ORN, PUT, AGM, SPERMD and SPERM, respectively. The correlation coefficients are greater than 0.9980. Coefficients of variation are not higher than 6.0% for inter-day precision. The method has been determined or tested for limits of detection and quantification, linearity, precision, accuracy and recovery. All detection parameters of the method demonstrate that it is a reliable and efficient means of the comprehensive determination of ARG and its 12 main metabolites, making this approach suitable for routine clinical applications. The levels of analysed compounds in human urine can be successfully determined using this developed method with no matrix effect.