Effect Of Temperature Factors Research Articles

Температурный фактор культивирования как регулятор морфогенеза растений картофеля in vitro

Introduction of biotechnological methods of reproduction in potato seed production has significantly increased the quality of seed material and rate of introduction of healthy and new high-yield varieties in production. The most important factors determining the success of micropropagation and the rate of multiplication of seed starting volume include nutritional factors (composition of nutrient media), hormonal factors (ratio of phytohormonal drugs in the nutrient solution) and physical cultivation factors (temperature and illumination). Many researchers have pointed out the importance of these parameters, but their recommended parameters vary considerably. This paper presents the results of studies on the effect of temperature factor on the development of cultivated potato plants. Regenerated potato plants of Rodrigo,Lyubava, Golubizna, Tuleevsky, Grand, Gulliver, Impala, Fritella, Innovator varieties were the objects of the study. During the studies established that at a phytotron temperature of 26±2°C, the development parameters of all varieties studied were higher than in the variant with a phytotron temperature of 22±2°C. The increase in height was between 36% and 190%, the number of internodes grew by 53-146%, and root formation by 12-42%, depending on the variety. Thus, this temperature regime contributes to more intensive organogenesis, and therefore contributes to the increase of potato multiplication coefficient in in vitro culture.

Optimal control of temperature feedback control ratchets

<sec>Biomolecular motors are macromolecules of enzyme proteins that convert chemical energy into mechanical energy. Experimental studies have shown that the directed movement of the biomolecular motor fully participates in the material transport process in the cell. Theoretically, the directed movement of biomolecular motors can be studied by the ratchet model. However, in most of feedback control ratchet models, none of the influences of external factors on experimental manipulation is considered, especially the inevitable random error, systematic error and human error in the experiment. Therefore, in order to further study the influences of error factors on feedback control ratchets, Cao's research group (Feito M, Cao F J <ext-link ext-link-type="uri" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://doi.org/10.1140/epjb/e2007-00255-7"> 2007 <i>Eur. Phys. J. B</i> <b>59</b> 63</ext-link>) pioneered the idea of error probability and discussed the transport behavior of feedback ratchets in the presence of error probability.</sec><sec>Based on Cao's error ratchet model, in this paper the temperature factor in introduced to further control the feedback ratchets, and the directed transport characteristics of the coupled Brownian particles in the temperature feedback ratchets are studied. The effects of temperature factor, phase difference and temperature frequency on the directed transport of coupled Brownian particles are discussed in detail. It is found that the temperature factor does not always reduce the directed transport of Brownian particles. There is a minimum value which means that the temperature factor can enhance the directed transport of the feedback ratchets within a certain change interval. In addition, in a small temperature amplitude range, the directed transport of the coupled particles exhibits a multi-peak structure with the change of temperature frequency. It is means that the appropriate temperature change frequency can enhance the directed transport of the feedback ratchets multiple times. The conclusions obtained in this paper can not only inspire experimental selection of appropriate temperature feedback information to optimize the directed transport of the Brownian ratchets, but also provide theoretical references for analyzing and processing the experimental data, especially error analysis.</sec>

A Numerical Model for the Temperature Regime of a Concrete Gravity Dam in the Climatic Conditions of Northern Vietnam

One of the main impacts on concrete gravity dams is the temperature factor. The effect of temperature factor on concrete dams will create additional deformation and stress, which can lead to tensile stresses and so gives rise to the thermal cracking. So, forecasting the thermal regime and thermal stress state in concrete gravity dams is a difficult task because taking into account a large number of influencing factors. This paper presents numerical modeling results on the temperature regime of the Banmong (Son La Province, Vietnam) concrete gravity dam with a height of 45m. The model has created by the MIDAS software package and can assess the influence of temperature factors on the dam structure during construction and operation period. The results obtained may be used when designing and making appropriate recommendations.

Influence of temperature factor on probabilistic characteristics of main mechanical properties and safety factors

Effect of temperature factor on probabilistic characteristics of main mechanical properties and safety factors has been investigated; this effect should be taken into account in the approaches when strength and lifetime of the structures working at low climatic temperatures under the conditions of Siberia and Extreme North are calculated. It is shown that in these conditions the main damaging factors for industrial facilities, equipment and main pipelines are low operating temperature, snow and ice loads. According to the data of experiment with using standard specimens and literature data for steel 15H2NMFA and steel 3 conducted by the proposed procedure the probabilistic characteristics of strength and plasticity under the conditions of homogeneous stress state at both normal and negative temperatures have been determined. In determining these characteristics, the initial data obtained during standard tests of laboratory samples under static loading (up to 30 samples) at room temperature were taken as the basis. The special aspects of distributions over some characteristics of general mechanical properties have been noted and a computational methodology for determining these characteristics at low temperatures is presented. The approaches to determination of probabilistic safety factors have also been considered. It is noted that an increase in the strength characteristics and the coefficient of operational loading with a decrease in temperature leads to a decrease in the safety factors with probability values of 1%.

ВЕГЕТАЦИОННЫЙ ПЕРИОД НОВЫХ КОЛЛЕКЦИОННЫХ ОБРАЗЦОВ БРОККОЛИ В ЮЖНОМ РЕГИОНЕ ДАГЕСТАНА

Background. Broccoli has valuable chemical composition, is a source of mineral elements, ascorbic acid, a significant amount of nitrogenous and biologically active substances, and has medicinal properties. For the year-round cultivation of this valuable crop in Dagestan, it is required to develop a conveyor of varieties and hybrids of different ripening groups, and determine the timing of planting seeds and transplanting seedlings. Materials and methods . Fourteen varieties and hybrids of broccoli from the global collection of VIR were studied in comparison with the 'Tonus' reference variety. Research was carried out at Dagestan Experiment Station of VIR in 2015-2017 in the summer/autumn season of crop cultivation. Seeds for seedlings were sown in open ground in the second 10-day period of June; shoots were obtained on June 23-24. Transplanting of the seedlings was carried out in the third 10-day period of July. The planting scheme was 70x40 cm; the plot area for one accession was 8.4 m2. Agricultural practice used for cultivation is generally accepted for cabbage family crops in the region. Results and conclusions. In the summer/autumn season of cultivation, it is possible to harvest high-quality broccoli crop in Derbent District. During the study, the length of the growing season for the accessions and the quality of the harvest were determined, taking into account the effect of temperature factors in the year of study. Optimal doses of mineral fertilizers and the best number of chemical treatments against pests were identified. To obtain a marketable head in broccoli, the main limiting factors are the temperature and humidity of soil and air. The longer the temperature stays within the range from 15 to 20°C during the growth period in the first phase after planting before the start of head formation, the higher is the yield. The longer the temperature remains above 25°C during the period from the beginning of head formation to the accession's full commercial fitness, the lower is the quality of the marketable head. The longer are the periods with temperatures between 15 and 20°C during the first growth phase and with temperatures between 10 and 15°C during the formation of the head, the lower is the percentage of broccoli heads with a rough uneven surface. The temperature above 20°C in the second phase was conducive to the formation of loose heads with emergence of flowers. Uniform formation of marketable heads was observed in the reference variety 'Tonus': 10% of central heads were formed on the 82nd day, and 100% on the 90th, that is within only eight days. Early-ripening broccoli varieties showed poor head quality: large buds, uneven surface, and rapid divarication of heads. Experimental data on the cultivation of marketable broccoli heads may be recommended to farmers and amateur vegetable growers.

Stimulated Brillouin scattering in Yb3+-doped dual-clad fiber lasers based on the temperature-dependent model

Temperature-dependent high power Yb3+-doped dual-clad fiber lasers model with stimulated Brillouin scattering (SBS) is proposed. The numerical simulation results show that the temperature distribution, laser power, pump power and Stokes powers propagating along axial positions are obtained after only few iteration times using number sequence transition method based on MATLAB BVP solvers (NSTM-BVPs). Compared the results of the fiber laser model without temperature factor, the SBS threshold powers and corresponding laser output powers at different fiber lengths and core diameters in our fiber laser model are obtained in detail. The effect of temperature factor on the SBS threshold power cannot be negligible for short fiber length less than 15m. While for long fiber length, the influences of temperature factor on the SBS threshold powers can be disregarded with fiber core diameter from 20μm to 40μm. In addition, the temperature factor has practically no effect on the corresponding laser output power to SBS threshold power.

Physicochemical Modeling of Hypergene Mineralization Processes in the Solnechnaya Reclamation Plant Tailing Dump (Khabarovsky Region) in the Temperature Range from -5 to +45 °C

The article presents the results of physicochemical modeling of hypergene processes in the tailing dump of the Solnechnaya Reclamation Plant (SRP). The effect of temperature factor on the hypergene minerals crystallization and pore solutions formation was researched.

Winter severity effects on the nonuniformity of winter flow formation in a river basin

Results of studying winter flow formation in the Northern Dvina and Lovat’ river basins are presented. Substantial effect of temperature factor on water exchange between upper and lower parts of a river basin is established.

Investigation of clorine trifluoride absorption by crystalline calcium carbonate

The effect of temperature factor on the efficiency of absorption of fluorine- and chlorine gas by a chemical absorbent, marble chips of a grade CA-MC, was researched. The degree of absorption of fluoride compounds at room temperature was 91%. The degree of recovery of total chlorine was 47.3%, that is because the low reactivity of the absorbent and an increase in an amount of Cl2 in gases due to displacement of it by the fluorides from formed CaCl2. Calculation of thermodynamic characteristics of the processes showed that the equilibrium constant for the reaction of chlorine with CaCO3 increased with a temperature growth, which proved larger intensity of the chlorine absorption by the hot absorbent. According to the suggested method, the gases containing chlorine fluorides successively passed through three distinct temperature zone of calcium carbonate: 230–600°C, 25–35°C and 300–600°C. In this case, the degree of recovery of fluorine compounds was 99%, and 98% of elemental chlorine was absorbed.

Three-dimensional biomechanical study of functional stresses in composite restorations of masticatory teeth

The aim of the present work was to study and evaluate the intensity of stresses in the adhesive bond in composite restorations of masticatory teeth after light-curing, under temperature changes and masticatory loads. Data for the 3D model generation of a maxillary premolar were obtained during a routine CT head scan. Thirty-three cross-sections of tooth 25 were selected and used to create a 3D geometric model enmeshed using the finite element method (FEM) (made up of 106556 elements and 608724 nodes). The pulp cavity and the periodontal ligament were constructed in the same way and integrated into the premolar model. Eight cavity configurations with converging walls were designed, resistant to masticatory forces (enamel/dentin = 1/1). A comparative computer simulation was carried out of the polymerization shrinkage forces of the composite material (CM), temperature changes in the oral cavity and functional masticatory loads. The distribution of the generated stress on the adhesive bond was evaluated in eight different class I and II cavity configurations. The location of crack formation was assessed in the cases of rupture of the adhesive bond. In all cavity configurations, stress concentration in the adhesive layer is higher at the interface with the dental tissues. Low temperatures (5 degrees C) generate forces that are greater than the strength of the adhesive bond in all studied cavity configurations. The distribution of the generated stresses under the effect of axial and tangent forces of 300 N is similar to that under the effect of temperature factors. The axial masticatory forces have a pronounced adverse effect on the adhesive bond in all cavity configurations. Low temperatures and axial masticatory forces play an important role for the marginal integrity. They exacerbate the adverse effects of polymerization shrinkage in composite restorations of masticatory teeth.

Effect of temperature factors on the optical properties of undyed fabrics

Effect of temperature factors on the optical properties of undyed fabrics

Effect of temperature factor and turbulence of the impinging stream on the transition in the boundary layer with gradient flow

An experimental study is made of the start of the transition and the extent of the transition zone in flow over a cooled wing profiled by a stream with an increased degree of turbulence in a wide range of Reynolds numbers.

Relative effect of temperature factor on turbulent gas boundary layer at finite reynolds numbers

Relative effect of temperature factor on turbulent gas boundary layer at finite reynolds numbers

Effect of scale and temperature factors on the compressive and shear strengths of plastics

Results are given of investigations of certain strength characteristics of a number of thermosetting plastics in relation to the scale of specimens reduced to 1/5 the standard size, i. e., the effect of the scale factor on the mechanical characteristics of plastics in compression and shear. In addition, results of a study of the dependence of the mechanical characteristics of plastics on the degree of heating in the temperature range from 20 to 200°C, i. e., the effect of the temperature factor on these characteristics, are also given.