Process behavior and product quality in fertilizer manufacturing using continuous hopper transfer pan granulation—Experimental investigations

Fertilizers are commonly used to improve the soil quality in both conventional and organic agriculture. One such fertilizer is dolomite for which soil application in granulated form is advantageous. These granules are commonly produced from ground dolomite powder in continuous pan transfer granulators. During production, the granulator’s operation parameters affect the granules’ properties and thereby also the overall performance of the fertilizer. To ensure product granules of certain specifications and an efficient overall production, process control and intensification approaches based on mathematical models can be applied. However, the latter require high-quality quantitative experimental data describing the effects of process operation parameters on the granule properties. Therefore, in this article, such data is presented for a lab-scale experimental setup. Investigations were carried out into how variations in binder spray rate, binder composition, feed powder flow rate, pan inclination angle, and angular velocity affect particle size distribution, mechanical stability, and humidity. Furthermore, in contrast to existing work samples from both, pan granules and product granules are analyzed. The influence of operation parameter variations on the differences between both, also known as trajectory separation, is described quantitatively. The results obtained indicate an increase in the average particle size with increasing binder flow rate to feed rate and increasing binder concentration and the inclination angle of the pan. Compressive strength varied significantly depending on the operating parameters. Significant differences in properties were observed for the product and the intermediate (pan) samples. In fact, for some operation parameters, e.g., binder feed rate, the magnitude of the separation effect strongly depends on the specific value of the operation parameter. The presented concise data will enable future mathematical modeling of the pan granulation process, e.g., using the framework of population balance equations

Combined Use of High-Sensitive Cardiac Troponin, Copeptin, and the Modified HEART Score for Rapid Evaluation of Chest Pain Patients.

Clinical short-term risk stratification is a recommended approach in patients with chest pain and possible acute myocardial infarction (AMI) to further improve high safety of biomarker-based rule-out algorithms. The study aim was to assess clinical performance of baseline concentrations of high-sensitivity cardiac troponin T (hs-TnT) and copeptin and the modified HEART score (mHS) in early presenters to the emergency department with chest pain. This cohort study included patients with chest pain with onset maximum of 6 h before admission and no persistent ST-segment elevation on electrocardiogram. hs-TnT, copeptin, and the mHS were assessed from admission data. The diagnostic and prognostic value for three baseline rule-out algorithms: (1) single hs-TnT < 14 ng/l, (2) hs-TnT < 14 ng/l/mHS ≤ 3, and (3) hs-TnT < 14 ng/l/mHS ≤ 3/copeptin < 17.4 pmol/l, was assessed with sensitivity and negative predictive value. Primary diagnostic endpoint was the diagnosis of AMI. Prognostic endpoint was death and/or AMI within 30 days. Among 154 enrolled patients, 44 (29%) were classified as low-risk according to the mHS; AMI was diagnosed in 105 patients (68%). For ruling out AMI, the highest sensitivity and NPV from all studied algorithms were observed for hs-TnT/mHS/copeptin (100%, 95% CI 96.6-100, and 100%, 95% CI 75.3-100). At 30 days, the highest event-free survival was achieved in patients stratified with hs-TnT/mHS/copeptin algorithm (100%) with 100% (95% CI 75.3-100) NPV and 100% (95% CI 96.6-100) sensitivity. The combination of baseline hs-TnT, copeptin, and the mHS has an excellent sensitivity and NPV for short-term risk stratification. Such approach might improve the triage system in emergency departments and be a bridge for inclusion to serial blood sampling algorithms

Analiza wykorzystania czasu pracy kierowców

W artykule przedstawiono najważniejsze czynniki i ograniczenia wpływające na efektywność wykorzystania czasu pracy kierowców. Badania wykonało dwóch kierowców w ciągu czterech tygodni, pracując na trasach dalekodystansowych z naczepą podkontenerową oraz kurtynową. Średni dzienny czas pracy kierowców wyniósł odpowiednio 11:55 i 10:27, dzienny czas jazdy – 5:30 i 6:21, a odległość dzienna 499 i 506 km. Współczynnik efektywności czasowej osiągnął wartość 0,45.The most important factors and limitations, that affecting of the efficiency of time consumption by truck drivers were presented. The study was done basic on data collected by two drivers during four weeks of work on long-haul routes with container and curtain trailer. The average daily working time of drivers was 11 hours 55 minutes and 10 hours 27 minutes. Daily driving time 5 hours 30 minutes and 6 hours 21 minutes. Daily distance 499 km and 506 km per driver. Time efficiency factor reached 0.45

Common greenhouse conditioning plants compared with versatile geothermal system in Ames, Iowa

Energy consumption is one of the most important factors related to profitability in greenhouse systems, and it is a factor in both financial considerations and environmental impacts. Competitiveness in the greenhouse industry is highly dependent upon the energy demand of heating systems. This paper focuses on the use of geothermal energy in agricultural sector. A ground source heat pump system was designed for a new greenhouse complex in Ames, Iowa. An accurate study of the external air temperatures, solar radiation, time, wind speed, and boundary conditions was conducted. Electrical and heating energy, and power demands were analysed. For the greenhouse design presented, the greatest power demand was 350 kW for heating and 620 kW for cooling. These values permitted the greenhouse to be maintained at the temperature of 16.7 ºC, when the external temperature ranged from -20 ºC to 30 ºC. An economic analysis was conducted considering only the energy demand cost, and this cost was compared with the equivalent energy cost of fuel oil and natural gas systems for heating and the equivalent energy cost of the fan and pad systems for cooling. For heating purposes, the economic analysis showed that the total energy demand cost over the nine years of using a closed-loop GWHP was around 120,000 USD, whereas the fuel oil system was 364,000 USD, and the natural gas system was 253,000 USD. This yields cost savings of 67 % and 53 %, respectively. For the cooling purposes, the economic analysis is inconsistent, and the fact, the energy cost difference between the closed-loop ground source heat pump cooling system and fad and pad systems is huge, 83,000 USD for closed-loop ground source heat pump cooling and around 5,200 USD for the fan and pad system energy in nine years