Toward Polymeric and Polymer Composites Impeller Fabrication

Impellers are referred to as a core component of turbomachinery. The use of impellers in various applications is considered an integral part of the industry. So, increased performance and the optimization of impellers have been the center of attention of a lot of studies. In this regard, studies have been focused on the improvement of the efficiency of rotary machines through aerodynamic optimization, using high-performance materials and suitable manufacturing processes. As such, the use of polymers and polymer composites due to their lower weight when compared to metals has been the focus of studies. On the other hand, methods of the manufacturing process for polymer and polymer composite impellers such as conventional impeller manufacturing, injection molding and additive manufacturing can offer higher economic efficiency than similar metal parts. In this study, polymeric and polymer composites impellers are discussed and conclusions are drawn according to the manufacturing methods. Studies have shown promising results for the replacement of polymers and polymer composites instead of metals with respect to a suitable temperature range. In general, polymers showed a good ability to fabricate the impellers, however in more difficult working conditions considering the need for a substance with higher physical and mechanical properties necessitates the use of composite polymers. However, in some applications, the use of these materials needs further research and development.

Cloud Point Extraction with Liquid Ion Exchange for Separation and Determination Magnesium (II) as anion

Liquid Ion Exchange joined with Cloud point extraction methodology was used for the separation of Magnesium (II) from aqueous and determine whereas 10 mL aqueous solution that contains 50 µg Mg2+ ion is complex with 1×10-3M 8-Hydroxy quinoline (8-HQ) at a suitable basic medium it well give higher extraction efficiency at optimum conditions, needs heating the aqueous solution in suitable temperature degree for enough time to form a cloud point layer (CPL). Therefore, the optimum conditions that yielded the good CPL have a small aggregation volume which is appropriate for continuing the ion pair association Complex between Magnesium ion and 8-Hydroxy quinoline.

Single-step and double-step heath recuperation of waste water from thermal baths

Thermal baths in Slovakia are producers of wastewater, which hides considerable energy potential. The wastewater from the thermal pools has often exceeds the maximum permissible value of the temperature of the wastewater discharged into the water recipient. As a result, there is undesirable damage to the environment, which results in sanctions for the operators of these facilities. Our aim is to present the concept of a single- and double-step heat recuperation system of waste pool water using applications of various types of heat exchangers or heat pumps. The aim of this application is to ensure a suitable temperature to the discharged waste pool water, efficient use of the energy potential of the waste water and saving of primary energy in the form of geothermal water, thus extending the life of the entire system.

Assessing suitability of temperature-based reference evapotranspiration methods for semi-arid basin of Maharashtra

FAO Penman-Monteith (FAO-PM) is deemed as a sole standard method for estimating reference evapotranspiration (ET ). However, limited availability of meteorological data at spatial and temporal o scales restricts the application of this method. To address this issue, the FAO 56 experts suggested three methods when only maximum and minimum temperature data are available: (i) Temperature-based Penman-Monteith (PMT-1) method wherein T ≈ T (ii) PMT-2 wherein T ≈ T -2.5, and (iii) dew min dew min Hargreaves method. These ET methods were assessed for a semi-arid basin of Western India which lacks adequate climatic data. The performances of the ET methods were evaluated against the standard FAO-PM method using salient statistical and graphical indicators, together with the sensitivity analysis. The results of the three temperature-based methods had a tendency of over-predication of ET in the study area. The PMT-1 method, however, provided superior ET estimates compared to PMT-2 and Hargreaves methods. For estimating monthly ET , the FAO-PM method was most sensitive to temperature. Further, ET of the monsoon season over the study area increased from 5 to 12% during 'drought' years compared to 'normal' years. It was concluded that PMT-1 method is the most suitable temperature-based method for estimating ET in semi-arid regions under limited climatic condition.

Towards Optimal Thermal Distribution in Magnetic Hyperthermia

A linear combination of spherically symmetric heat sources is shown to provide optimal stationary thermal distribution in magnetic hyperthermia. Furthermore, such spatial location of heat sources produces suitable temperature distribution in biological medium even for assemblies of magnetic nanoparticles with a moderate value of specific absorption rate (SAR), of the order of 100 - 150 W/g. We also demonstrate the advantage of using assemblies of magnetic nanocapsules consisting of metallic iron nanoparticles covered with non magnetic shells of sufficient thickness in magnetic hyperthermia. Based on numerical simulation we optimize the size and geometric structure of biocompatible capsules in order to minimize the influence of strong magneto-dipole interaction between closely spaced nanoparticles. It is shown that assembly of capsules can provide sufficiently high SAR values of the order of 250 - 400 W/g at moderate amplitudes H0·= 50 - 100 Oe and frequencies f = 100 - 200 kHz of alternating magnetic field, being appropriate for application in clinics.

Influence of Concentration and Temperature on Stability of Imipenem Focused on Solutions for Extended Infusion

Background Imipenem remains active against most Gram-positive and Gram-negative organisms. This study aimed to evaluate chemical stability of imipenem in 2 commonly used concentrations when stored in 3 various temperatures. Methods Imipenem injection powder was used to prepare 5 mL and 10 mg/mL of imipenem in .9% sodium chloride solution. Prepared solutions in PVC bags were stored at 25°C, 30°C, and 40°C. The solutions were investigated over 0, 1, 2, 3, 4, and 6 hours using HPLC analysis. The association between drug stability, temperature, and concentration was determined. Results The 5 mg/mL solutions of brand A and B imipenem mL were stable for 6 hours at 25°C, 30°C, and 40°C, respectively. For 10 mg/mL, the solution of brand A was stable for 3 hours and brand B was stable for 6 hours at 25°C. Also, brand A and B imipenem solutions at the concentration of 10 mg/mL were stable for less than 1 hour at 30°C and 40°C. Conclusion The stability of imipenem injection solution was affected by temperature and concentration. Increasing in temperature and drug concentration resulted in decreased stability of imipenem. Suitable temperature and drug concentration should be concerned when this drug is given by extended infusion.

Invasion Leptoglossus occidentalis Heidemann, 1910 (Heteroptera: Coreidae) in the conditions of Voronezh (Russia)

The article presents new data on the distribution and acclimatization of an alien species of the American coniferous bug (Leptoglossus occidentalis Heidemann, 1910) from the European part of Russia. This bug was discovered in the autumn of 2019 on the territory of the city of Voronezh in the Arboretum of the Voronezh State University of Forestry and Technologies. Currently, L. occidentalis spreads on the territory of Russia only in an urban environment, where it finds optimal environmental conditions (suitable temperature, humidity and shelter for winter locations). Surveys of a number of park and forest park zones, squares and separately growing coniferous trees conducted in 2019-2020 in Voronezh did not reveal the presence of this species. At the moment, in the conditions of the Voronezh region, the center of the spread of this bug is located only in the Arboretum of the Voronezh State University of Forestry and Technologies. In 2020, an increase in the number of the identified group of L. occidentalis was recorded. Further spread of the bug is predicted on the territory of Voronezh. At the moment, no danger to conifers in the European part of Russia from L. occidentalis has been identified and is not yet expected, but constant monitoring of the detected group is required.

Overwinter Storage of European Beech and Norway Spruce Planting Stock: Effect of Different Methods and Temperature Conditions

The aim of this research was to compare methods of overwinter storage of forest tree species planting stock and to specify of the optimal and the minimal temperature for freezing. Planting stock of European beech and Norway spruce were stored three times over a period of dormancy (2015/2016, 2016/2017, 2017/2018) (1) in freezers, (2) in an air-conditioned warehouse, (3) in a cave and (4) in soil (bare-rooted plants) and at a holding area (containerized plants), i.e., an open storage. During storage, the vitality of plants was determined using the root electrolyte leakage (REL) parameter, and in 2016 also by restoring growth in a sample of plants. The stored plants were always planted in a forest research plot in the spring and their basic morphological parameters and mortality were evaluated at the end of the growing season. The most suitable temperature for storage of both bare-rooted and containerized beech and spruce was in the range from −3.4 °C to −1.7 °C. The plants after overwinter storage showed no significant mortality after planting–they showed a high vitality of the fine roots and a normal increment, and were not damaged by frost, mold or other negative factors during storage.

Myzus persicae Management through Combined Use of Beneficial Insects and Thiacloprid in Pepper Seedlings

Excessive insecticide application has posed a threat to pollinators and has also increased insecticide resistance of Myzus persicae Sulzer. Therefore, it is urgent to develop an economical and effective strategy, especially for greenhouse vegetables. Firstly, we selected a neonicotinoid insecticide that is specifically fatal to M. persicae but relatively safe to predators and bumblebees by laboratory toxicity tests and risk assessments. Then, we tested the effectiveness of the neonicotinoid insecticide under different temperature conditions. According to the LC50 values and the hazard quotients, thiacloprid met the requirements. Greenhouse trails indicated that thiacloprid was quite efficient, while control dropped to 80% without the application of thiacloprid. As for biological control, Harmonia axyridis effectively controlled 90% of aphids with thiacloprid or not. However, Aphidoletes aphidimyza performed better above 20 °C. Our results indicated that it is cost-effective to control M. persicae with A. aphidimyza in suitable temperature conditions and H. axyridis was more effective at low temperatures. Practically, thiacloprid could be used either as an emergency option to control aphids’ abundance alone or in combination with natural enemies.