ENGINEERING FOR RURAL DEVELOPMENT DOSAGE UNIFORMITY OF RAINFALL SIMULATOR DEPENDING ON NOZZLE TYPE AND PRESSURE

Abstract. Water erosion and its symptoms represent a worldwide problem. In the Czech Republic conditions are at risk by water erosion more than in half of the agricultural land. A rainfall simulator is a promising method of measuring of erosion values such as infiltration rate, surface runoff and amount of washed off soil. At the Department of Agricultural Machines (Czech University of Life Sciences Prague) the rainfall simulator for the mentioned measurements has been developed. For the operation of the rainfall simulator it is necessary to know the progress of the surface dose of the rainfall simulator for individual nozzles. Three types of nozzles were selected. Two of the nozzles have a circular spray pattern and the third has a square spray pattern. Firstly, the flow through the nozzles was measured for different operating pressures. Secondly, the surface dose of water per unit area was measured. The measurements showed the lack of the nozzle with the square spray pattern. The correlation between precision in the surface dose and operating pressure was also observed

Anténa sekundárního přehledového radaru

This paper deals with a secondary surveillance radar (SSR) array antenna, which is intended for a system combining the secondary surveillance radar antenna and the primary surveillance radar antenna. It describes the patch array elements and the synthesis for the secondary surveillance radar array, considering both elevation and azimuth patterns for sum, difference, and sidelobe-suppression beams, and suspended stripline couplers. The utilization of multilayer techniques allows the connection of layers with patch radiating elements and layers with beamforming networks

Construction of Larger Molecular Aluminophosphate Cages from the Cyclic Four-Ring Building Unit

New molecular aluminophosphates of different nuclearity are synthesized by a stepwise process and structurally characterized. The alkane elimination reaction of bis(trimethylsiloxy)phosphoric acid, OP-(OH)(OSiMe3)(2), with trialkylalanes, AlR3 (R = Me, Et, Bu-i), provides the cyclic dimeric aluminophosphates, [(AlR2{mu(2)-O2P(OSiMe3)(2)})(2)) (R = Me (1), Et (2), Bu-i (3)). Unsymmetrically substituted cyclic aluminophosphonate [(AlMe2{mu(2)-O2P(OSiMe3)((c)Hex)})(2)] (cis/trans-4) is prepared by dealkylsilylation reaction of (c)HexP(O)(OSiMe3)(2) with AlMe3. Molecules 1-4 containing the [Al-2(mu(2)-O2P)(2)] inorganic core are structural and spectroscopic models for the single four-ring (S4R) secondary building units (SBU) of zeolite frameworks. Compound 1 serves as a starting point in construction of larger molecular units by reactions with OP(OH)(OSiMe3)(2) as a cage-extending reagent and with diketones, such as Hhfacac (1,1,1,5,5,5-hexafluoropentan-2,4-dione) and Hacac (pentan-2,4-dione), as capping reagents. Reaction of 1 with 4 equiv of Hhfacac leads to new cyclic aluminophosphate [(Al(hfacac)(2){mu(2)-O2P(OSiMe3)(2)})(2)] (5), existing in two isomeric (D-2 and C-2h) forms. Reaction of 1 with 2 equiv of OP(OH)(OSiMe3)(2) and 1 equiv of Hhfacac provides a molecular aluminophosphate [AlMe{Al(hfacac)}(2){mu(3)-O3P(OSiMe3)}(2){mu(2)-O2P(OSiMe3)(2)}(2){OP-(OSiMe3)(3)}] (6), while by adding first the Hhfacac and using 3 equiv of OP(OH)(OSiMe3)(2) we isolate [Al{Al(hfacac)}(2){mu(3)-O3P(OSiMe3)}(2){mu(2)-O2P(OSiMe3)(2)}(2)H{OP(O)(OSiMe3)(2)}(2)] (7). These molecules contain units in their cores that imitate 4=1 SBU of zeolite frameworks. Reaction with the order of component mixing 1, Hhfacac, OP(OH)(OSiMe3)(2) at a 1:2:2 molar ratio lead to formation of a larger cluster [(Al(AlMe){Al(hfacac)}{mu(3)-O3P(OSiMe3)}(2){mu(2)-O2P(OSiMe3)(2)}(3))(2)] (8) containing both S4R and 4=1 structural units. Similarly, Hacac (pentan-2,4-dione) provides an isostructural [Al(AlMe){Al(acac)}{mu(3)-O3P(OSiMe3)}(2){mu(2)-O2P(OSiMe3)(2)}(3))(2)] (9). Both molecules display Al centers in three different coordination environments

Monitoring of Khorasan (Triticum turgidum ssp. Turanicum) and Modern Kabot Spring Wheat (Triticum aestivum) Varieties by UAV and Sensor Technologies under Different Soil Tillage

Khorasan wheat (Triticum turgidum ssp. turanicum (Jakubz.)) is an ancient tetraploid spring wheat variety originating from northeast parts of Central Asia. This variety can serve as a full-fledged alternative to modern wheat but has a lower yield than modern varieties. It is commonly known that wheat growth is influenced by soil tillage technology (among other things). However, it is not known how soil tillage technology affects ancient varieties. Therefore, the main objective of this study was to evaluate the influence of different soil tillage technologies on the growth of the ancient Khorasan wheat variety in comparison to the modern Kabot spring wheat (Triticum aestivum) variety. The trial was arranged in six small plots, one half of which was sown by the Khorasan wheat variety and the other half of which was sown by the Kabot wheat variety. Three soil tillage methods were used for each cultivar: conventional tillage (CT) (20–25 cm), minimum tillage (MTC) with a coulter cultivator (15 cm), and minimization tillage (MTD) with a disc cultivator (12 cm). The soil surface of all of the variants were leveled after tillage (harrows & levelling bars). An unmanned aerial vehicle with multispectral and thermal cameras was used to monitor growth during the vegetation season. The flight missions were supplemented by measurements using the GreenSeeker hand-held sensor and plant and soil analysis. The results showed that the Khorasan ancient wheat was better suited the conditions of conventional tillage, with low values of bulk density and highvalues of total soil porosity, which generally increased the nutritional value of the yield in this experimental plot. At the same time, it was found that this ancient wheat does not deplete the soil. The results also showed that the trend of developmental growing curves derived from different sensors was very similar regardless of measurement method. The sensors used in this study can be good indicators of micronutrient content in the plant as well as in the grains. A low-cost RGB camera can provide relevant results, especially in cases where equipment that is more accurate is not available

Nonaqueous synthesis of molecular zinc amide phosphate

Three new molecular zinc compounds were prepared by nonaqueous reactions of Zn[N(SiMe3)(2)](2) and ZnEt2 with trimethylsilylesters of phosphoric acid, OP(OSiMe3)(3) and OP(OSiMe3)(2)(OH). Single-crystal Xray diffraction analyses of crystalline products revealed molecular structures of two mononuclear complexes [ZnX2OP(OSiMe3)(3)] (X = N(SiMe3)(2) (1), hfacac = hexafluoroacetylacetonate, (2)) and one dinuclear zinc phosphate [(Zn{(py)N(SiMe3)(2)}{mu(2)-O2P(OSiMe3)(2)})(2)] (3). Compound 1 is only the second structurally characterized adduct of zinc bisamide with an oxygen donor and a three-coordinate Zn atom. The cyclic inorganic core {Zn(mu(2)-O2PO2)}(2) in 3 is a model for the most common single four-ring (S4R) building unit of open-framework zinc phosphates. The molecule of 3 possesses reactive amide and tri-methylsiloxy groups that can be employed in further studies on the formation of extended structures by condensation reactions. Spectroscopic properties and thermal behavior of the molecular products were examined. Compounds 1 and 3 were converted to alpha-Zn2P2O7 by calcination. (C) 2013 Elsevier B. V. All rights reserved

Effect of soil tillage technologies on soil properties in long term evaluation

Soil compaction is a major problem of modern agriculture. Soil compaction increases due to growth of the weight of agricultural machines and the number of passes over land. Soil compaction may be significantly reduced by using suitable soil tillage. One indicator of compaction can be cone index. It was established field trial with six variants of tillage. On 3 variants were used ploughing systems and other 3 used reduced systems of tillage. Experiment was conceived as a multi-annual and was run from 2010 to 2014. The soil on the land was shallow sandy loam cambisol. Registration penetrometer was used for measurement. Cone index was measured at the depth of 0.04 m to 0.32. Each plot had size 6 x 50 m. The results were evaluated after 5 years of the experiment. The results showed a difference of the cone index values between variants. The variants with ploughing are apparent initial favourable effect of loosening with a strong transition of not processed layers. There are no visible transitions in variants with reduced tillage. But the values of cone index in the surface layers have higher values than the variants with ploughingVytauto Didžiojo universitetasŽemės ūkio akademij

Through-Space Paramagnetic NMR Effects in Host–Guest Complexes: Potential Ruthenium(III) Metallodrugs with Macrocyclic Carriers

The potential of paramagnetic ruthenium­(III) compounds for use as anticancer metallodrugs has been investigated extensively during the past several decades. However, the means by which these ruthenium compounds are transported and distributed in living bodies remain relatively unexplored. In this work, we prepared several novel ruthenium­(III) compounds with the general structure Na⁺[<i>trans</i>-Ru^IIICl₄(DMSO)­(L)]⁻ (DMSO = dimethyl sulfoxide), where L stands for pyridine or imidazole linked with adamantane, a hydrophobic chemophore. The supramolecular interactions of these compounds with macrocyclic carriers of the cyclodextrin (CD) and cucurbit­[<i>n</i>]­uril (CB) families were investigated by NMR spectroscopy, X-ray diffraction analysis, isothermal titration calorimetry, and relativistic DFT methods. The long-range hyperfine NMR effects of the paramagnetic guest on the host macrocycle are related to the distance between them and their relative orientation in the host–guest complex. The CD and CB macrocyclic carriers being studied in this account can be attached to a vector that attracts the drug-carrier system to a specific biological target and our investigation thus introduces a new possibility in the field of targeted delivery of anticancer metallodrugs based on ruthenium­(III) compounds

Through-Space Paramagnetic NMR Effects in Host–Guest Complexes: Potential Ruthenium(III) Metallodrugs with Macrocyclic Carriers

The potential of paramagnetic ruthenium­(III) compounds for use as anticancer metallodrugs has been investigated extensively during the past several decades. However, the means by which these ruthenium compounds are transported and distributed in living bodies remain relatively unexplored. In this work, we prepared several novel ruthenium­(III) compounds with the general structure Na⁺[<i>trans</i>-Ru^IIICl₄(DMSO)­(L)]⁻ (DMSO = dimethyl sulfoxide), where L stands for pyridine or imidazole linked with adamantane, a hydrophobic chemophore. The supramolecular interactions of these compounds with macrocyclic carriers of the cyclodextrin (CD) and cucurbit­[<i>n</i>]­uril (CB) families were investigated by NMR spectroscopy, X-ray diffraction analysis, isothermal titration calorimetry, and relativistic DFT methods. The long-range hyperfine NMR effects of the paramagnetic guest on the host macrocycle are related to the distance between them and their relative orientation in the host–guest complex. The CD and CB macrocyclic carriers being studied in this account can be attached to a vector that attracts the drug-carrier system to a specific biological target and our investigation thus introduces a new possibility in the field of targeted delivery of anticancer metallodrugs based on ruthenium­(III) compounds

Long-Term Monitoring of Different Field Traffic Management Practices in Cereals Production with Support of Satellite Images and Yield Data in Context of Climate Change

Cereals in Europe are mainly grown with intensive management. This often leads to the deterioration of the physical properties of the soil, especially increasing bulk density due to heavy machinery traffic, which causes excessive soil compaction. Controlled traffic farming (CTF) technology has the potential to address these issues, as it should be advantageous technology for growing cereals during climate change. The aim of this study was to compare the yield potential of CTF and standardly used random traffic farming (RTF) technology using yield maps obtained from combine harvester and satellite imagery as a remote sensing method. The experiment was performed on a 16-hectare experimental field with a CTF system established in 2009 (with conversion from a conventional (ploughing) to conservation tillage system). Yield was compared in years when small cereals were grown, a total of 7 years within a 13-year period (2009&ndash;2021). The results show that CTF technology was advantageous in dry years. Cereals grown in the years 2016, 2017 and 2019 had significantly higher yields under CTF technology. On the contrary, in years with higher precipitation, RTF technology had slightly better results&mdash;up to 4%. This confirms higher productivity when using CTF technology in times of climate change