High Frost Research Articles

The Effect of the Structure of the Alcohol Component on the Plasticizing Ability of the Ester of Aliphatic Dicarboxylic Acid

Esters of aliphatic dicarboxylic acids are promising plasticizers of polyvinyl chloride due to their low toxicity and high biodegradability. Plasticized PVC materials containing them are characterized by high frost resistance and heat resistance. In this regard, esters of adipic acid and alkoxylated alcohols with various structures have been obtained. The influence of alcohol structure on the plasticizing ability of ether has been determined. A theoretical assessment of the plasticizing effect of diesters in relation to PVC was performed based on the calculation of Hansen solubility parameters. For this purpose, the thermodynamic compatibility of adipates with PVC was investigated. The processability of esters in the composition of PVC compositions was studied according to the values of the critical temperature of dissolution of PVC. The intervals of transition of plastics from a glassy to a highly elastic state, as well as the depression of the glass transition temperature of compounds containing adipates, were determined. Rheological characteristics of PVC compositions based on the obtained adipates were investigated. It is shown that the chemical structure of the alcohol group determines the important technological and operational characteristics of esters in the composition of polymer materials.

Economic and biological assessment of a new medium-ripened variety of soft winter wheat Priazovye

Relevance. In the Russian Federation, winter common wheat is the main food and strategic crop. Permanent improvement of productivity and quality of wheat grain, reducing its production costs is the main task of agricultural production. To solve this problem, the leading place is given to the continuous and constant creation and introduction into production of new competitive wheat varieties, highly adapted to stress factors, with guaranteed high yields and high grain quality.Methods. The research was carried out in the southern zone of the Rostov region at the experimental sites of the Federal State Budgetary Scientific Institution ANTS “Donskoy” in 2021–2023 in order to create a new variety of soft winter wheat capable of forming not only high yields, but also having high frost resistance, drought resistance, resistance to leaf diseases, possessing high rheological and technological properties of grain and flour.Results. The winter common wheat variety Priazovie was developed by stepwise hybridization using the varieties Voyazh and Tanya. This is a highly productive variety. On average, over three years (2021–2023) of study in the competitive variety testing, the productivity of the variety laid in green manure fallow was 9.88 t/ha, exceeding that of the standard variety by 1.56 t/ha. The variety is capable of producing high yields after various forecrops. The maximum productivity of the variety (12.23 t/ha) was obtained in green manure fallow in 2022. The variety forms a high stem capacity (up to 800 pcs/m²), and is characterized by high resistance to the main leaf diseases, such as powdery mildew, brown and yellow mildew, loose smut, leaf blotch, etc. According to the main indicators of grain and flour quality, it belongs to valuable wheat, in terms of frost resistance (73.3%) it surpasses the standard Ermak variety (69.2%).

РОЛЬ САСО3 У ФОРМУВАННІ МІЦНІСНИХ І ДЕКОРАТИВНИХ ВЛАСТИВОСТЕЙ ПОРОШКОВОГО ЛУЖНО-АКТИВОВАНОГО ШЛАКОПОРТЛАНДЦЕМЕНТНОГО БЕТОНУ

The article discusses approaches to the formation of compositions of alkali-activated decorative Portland slag cements containing Portland cement type CEM1 5...45% with high performance and decorative properties. The optimization of the compositions of decorative alkali-activated Portland slag cements was carried out using statistical methods for designing experiments. Finely dispersed TiO2 and CaCO3 additives with a whiteness of 90% were used as bleaching components. The alkaline component is sodium metasilicate in the form of a non-hygroscopic powder. The research carried out made it possible to obtain decorative Portland slag cements with a whiteness of 45...77%, which allows them to be used to produce colored cements with a wide range of colors from white to black. It has been established that alkali-active decorative Portland slag cements have an activity of 37...59 MPa at the age of 28 days. All compositions have good hardening dynamics and, based on the strength at the age of 2 days  22...36.6 MPa, they can be classified as fast-hardening. Based on them, it is possible to produce dry construction mixtures. All mortar compositions based on alkali-active decorative Portland slag cements demonstrate fairly high frost resistance  F200. This allows them to be used for the manufacture of products and solutions both for indoor use and when exposed to atmospheric influences without loss of design characteristics and decorative appeal. The inherent shrinkage strains of decorative alkali-activated Portland slag cements are 0.51...0.61 mm/m, which eliminates cracking and premature destruction of products. The use of the CaCO3 additive is especially effective for controlling the shrinkage deformations. Thus, the CaCO3 additive performs the functions of not only a decorative component, but also a structure-forming component. Concrete and mortar mixtures can be used to produce decorative products using the traditional method, extrusion, 3D printing on construction printers, etc. And not too long setting times and a rapid increase in strength make it possible to produce products without thermal treatment or with minimal consumption of thermal energy.

Optical microscopy of ceramic materials based on fly ash from thermal power plants

The data on the annual release of ash and slag waste as a result of the operation of thermal power plants (TPP) in Siberia and the Far East of the Russian Federation are presented. The main reasons for the insignificant use of ash in the construction industry (about 5-8% of the total waste output) and the problems hindering its use for the production of ceramic wall materials are considered. A brief description of the composition and properties of the raw materials used in this work for the manufacture of ceramic wall materials is given. The compositions of the developed fly ash-based charges and the method of manufacturing ceramic samples with a matrix structure are given. The results of the study of the structure of ceramic materials by optical microscopy are presented. It is established that during the firing process, a matrix (dispersion medium) is formed from the fusible shell of aggregated complexes, and granules from fly ash are transformed into cores (dispersed phase) of a ceramic matrix composite. It was revealed that the kernels have an oval shape due to the deformation of the granules during pressing. Clusters are formed in the nuclei, consisting of a large number of small crystalline grains connected by an amorphous substance and edged with thin chains of pores. It is shown that the developed pore space inside the cores is mainly represented by frost-proof and reserve pores, which ensures high frost resistance of ceramic samples based on fly ash.

Phenotypic characteristics of black apricot Prunus × dasycarpa cultivar ‘Shlor-Tsiran’ in Armenia

ABSTRACT ‘Shlor-Tsiran’ (literally called ‘Plum-Apricot’) is an old black apricot cultivar, which is traditionally cultivated in Armenia. Taxonomically, it belongs to Prunus × dasycarpa Ehrh., which is a spontaneous hybrid of apricot and cherry plum (P. armeniaca L. × P. cerasifera Ehrh.). Currently, ‘Shlor-Tsiran’ is considered to be very rare in Armenia and it occurs as single trees in old home orchards of the Ararat Valley. It is characterised by high frost and disease resistance, late flowering and fruiting compared with other cultivated apricots, and is of interest for the development of apricot cultivars displaying delayed fruit ripening and enhanced frost resistance. This study aims to phenotype the cv. ‘Shlor-Tsiran’ taking into consideration 67 quantitative and qualitative characteristics of vegetative and generative organs, growth and development. Morphological description of the cv. ‘Shlor-Tsiran’, comparing with its parent species, P. armeniaca and P. cerasifera, was performed. Data on fertility and viability of pollen grains, biochemical and nutritional properties of fruits and tree productivity are provided. The data obtained should contribute to a wider use and conservation of the black apricot cv. ‘Shlor-Tsiran’ gene pool, which can be used for breeding purposes as well. The article is illustrated with tables and original photographs.

Применение бентонитовой глины в качестве гидроизоляционного материала

Purpose: analytical study of usability bentonite is a natural mineral with high waterproofing and adsorption properties in various fields. Methods: methods of comparative analysis, synthesis, generalization, analogy were used. Results: this article examines various applications of bentonite, allowing to position bentonite as a universal material, which is widely used in various industries due to its unique properties. The advantages of bentonite over other waterproofing materials are noted, including environmental friendliness, durability, efficiency and economy. The properties of bentonite clay have been studied, the ability of which to swell and create a waterproofing barrier in contact with water makes it an effective material for protection against moisture. It is indicated that the high frost resistance of bentonite is ensured due to the complex structure of the material consisting of metal oxide atoms and silicon atoms, which form a dense structure. The interlayer space in which the exchange cations are concentrated is the physical and physicochemical basis for the sorption activity of bentonite clay rocks. Bentonite has been found to be of value in its self-healing properties, as is the case when used at negative temperatures. This is due to its molecular structure. The microscopic particles that make up bentonite have a negative charge, they are able to adsorb water molecules. Practical significance: waterproofing works are carried out in many areas of construction. However, bentonite materials are not widely used. In this aspect, the article describes in detail such waterproofing materials as bentonite mats, clay lock, injectable bentonite waterproofing. The authors believe that the demand for the use of bentonite as a reliable and promising means of waterproofing in the construction industry will increase.

Life cycle assessment of active spring frost protection methods in viticulture: A framework to compare different technologies

In viticulture, the risk of spring frost is mainly due to earlier budbreak, increasing the vulnerability of buds and green organs to freezing temperatures. Active Spring Frost Protection Methods (ASFPMs) aim to mitigate this risk by increasing the temperature in the bud area. ASFPMs are often seen as highly labour-intensive and resource consuming practices. ASFPM technologies are diverse and influenced by different external drivers, affecting differently their application strategies and the required equipment for efficiency. This study proposes a framework for analysing and comparing ASFPMs’ potential environmental impacts using Life Cycle Assessment (LCA) methodology. We illustrate this proposal with an example: Winter cover, wind machine, sprinkler and anti-frost candles comparison in Loire Valley conditions. We modeled the attributional LCAs with Impact world + characterisation method using Abribalyse 3.1 and Ecoinvent 3.8 databases. Application and climatic scenarios were elaborated to set conditions of ASFPMs use. The overall combination of attributional LCAs and external scenarios designs a context-specific LCA. Required time of application for each ASFPM to protect 1 ha during frost hours was determined using linear regression of ASFPM application time in function of total seasonal frost hours based on a recent decade (2013–2023). Sensitivity analysis consisted in varying frost hours theoretically with a step of 1 unit, using the lowest and highest frost hour numbers from 2013 to 2023 as boundaries. Overall, the ranking between ASFPM environmental scores changes based on the theoretical frost duration. The implementation of context-specific elements allowed for the development of system boundaries in attributional LCA, enabling the analysis and comparison of different types of technologies. The framework of this study showed its relevance in the context of ASFPM technologies through a concrete example in Loire Valley viticulture. Future research may consider other contextual elements and ASFPM technologies. This framework could be used in different fields of study to analyse and compare contrasted technologies in terms of environmental impacts.

Frost Resistance of Silicate Bricks

The article presents the results of a research frost resistance of silicate bricks one of the Russian factories produced in different periods. The change in appearance, weight and strength of silicate bricks during alternate freezing-thawing was evaluated. It has been established that silicate bricks, can meet high frost resistance grades F150-200, in terms of appearance, while the reduction in compressive strength does not exceed 9%. Some increase in brick strength at the initial stage of testing was noted, which is probably explained by the processes of carbonization of free calcium hydroxide and high-basic calcium hydrosilicates, accompanied by their recrystallization into low-basic ones, which is confirmed by the results of differential-thermal and X-ray phase analysis. It is concluded that the frost resistance of silicate bricks is decisively influenced by the mineralogical composition of the cementitious bond. High strength and frost resistance of silicate concrete is provided by the simultaneous presence of low-basic calcium hydrosilicates and α-C2S hydrate in the composition of the new formations. The condition for the formation of such composition of neoplasms is excessive content of lime in the composition of the raw material mixture.

High risk, high gain? Trade-offs between growth and resistance to extreme events differ in northern red oak (Quercus rubra L.).

Information about the resistance and adaptive potential of tree species and provenances is needed to select suitable planting material in times of rapidly changing climate conditions. In this study, we evaluate growth responses to climatic fluctuations and extreme events for 12 provenances of northern red oak (Quercus rubra L.) that were tested across three trial sites with distinct environmental conditions in Germany. Six provenances each were sourced from the natural distribution in North America and from introduced stands in Germany. We collected increment cores of 16 trees per provenance and site. Dendroecological methods were used to compare provenance performance and establish climate-growth relationships to identify the main growth limiting factors. To evaluate the provenance response to extreme drought and frost events, three site-specific drought years were selected according to the Standardized Precipitation Evapotranspiration Index (SPEI) and 2010 as a year with an extreme late frost event. Resistance indices for these years were calculated and assessed in relation to overall growth performance. We observed a high variation in growth and in the climate sensitivity between sites depending on the prevailing climatic conditions, as well as a high intra-specific variation. Overall, summer drought and low temperatures in the early growing season appear to constrain the growth of red oak. The resistance of provenances within sites and extreme years showed considerable rank changes and interaction effects. We did not find a trade-off between growth and resistance to late frost, namely, fast growing provenances had a high frost hardiness. Further, there was no evidence for a trade-off between growth and drought hardiness. Still, responses to drought or late frost differ between provenances, pointing to dissimilar adaptive strategies. Provenances from introduced (i.e. German) stands represent suitable seed sources, as they combine a higher growth and frost hardiness compared to their North American counterparts. Drought hardiness was slightly higher in the slow-growing provenances. The results provide a better understanding of the variable adaptive strategies between provenances and help to select suitable planting material for adaptive forest management.

Effect of freeze-thaw cycles on water permeability of sand mixtures with nanoclay

The mixtures of sands and nanoclays are used to isolate municipal and industrial solid wastes. Compared with natural clayey soils, these mixtures are characterized by homogeneous composition, workability, and low compressibility. This study investigated the effect of freeze–thaw cycles on their permeability. The mixtures of four sands and a saponite clay suspension generated by diamond ore processing were studied. The mixtures were prepared on the basis of 4 % and 8 % clay from sand weight. The tests were performed using an apparatus consisting of four devices for measuring frost heave and permeability, which were placed in containers with water. The water level was decreased gradually to ensure sample freezing or increased to ensure sample thawing. The frost heave of the mixtures with 4 % clay was 10.0–16.4 % under an external load of 2 kPa, and the five freeze–thaw cycles resulted in an increase in the hydraulic conductivity by 2.0–4.7 times. The mixtures with 8 % clay were tested under a load of 12 kPa, because of their high frost susceptibility. The hydraulic conductivity increased by approximately the same value as in the first case, i.e., by 1.2–2.0 times. The experiments have shown that the examined mixtures are suitable for isolating wastes. However, to eliminate the above effect, a waterproof liner should be covered with inert soil, which would reduce the depth of frost penetration and apply the load on it.

Implementation of Large-Format 3D Façade Components Using Glass Fibre Reinforced Concrete:ČSOB Hradec Králové, C&A Zürich, Illuster Uster

Glassfibre reinforced concrete (GRC) is a close-grained concrete material reinforced with glass fibres that allows architects complete freedom in designing rear-ventilated façades. It can be shaped, coloured, surface-treated or otherwise tailored to the specific needs of their projects without significant limitations. The main properties of GRC material include its long life-time and sustainability. The results are visually appealing façade panels that can withstand adverse weather conditions for decades. The characteristic high strength and durability is achieved by dispersing glass fibres within the base mixture of Portland cement, sand, water and further refining additives. Fine-grained particles in the composite structure ensure low water absorbency and high frost resistance. This article is an overview of the technical solution and process of GRC façade design. It deals with the design possibilities for anchoring large-format and 3D shaped façade panels. The article further presents all of the above-mentioned characteristics and process details as they are used on three specific structures. The first presented project is the ČSOB Central Office in Hradec Králové, with its typical distinct ledges combined with glazed surfaces. The cascading entrance portal is a significant element of its façade. The next implementation chosen is the renovation of the C&A department store building in Zürich, Switzerland. This building’s façade is comprised of structured large-area panels with distinctive frames. The article concludes with the creatively implemented renovation of the Illuster shopping centre in Switzerland, with its kaleidoscopic façade made up of glassfibre reinforced concrete panels.

Holocene warming of alpine rockwalls decreased rockwall erosion rates

Alpine rockwall erosion studies suggest that deglaciated rockwalls in the European Alps are eroding slower today than at earlier times in the Holocene. Explanations for this have included a waned glacial debuttressing effect since the retreat of Last Glacial ice loads and the establishment of more moderate climates, but seldom have such explanations been robustly tested. We combine field data with modelling to reconstruct changes in rockwall erosion and associated climate drivers, in an alpine valley of the European Alps since the beginning of the Holocene. Paleo (Holocene to decadal-scale) erosion rates were calculated from talus accumulation below rockwalls, and compared with recent rates (2016–2019) measured from repeat laserscan surveys of the same rockwalls. We reconstructed the glacial retreat history in the valley, and modelled Holocene changes in permafrost distribution and frost cracking using calibrated rockwall temperature reconstructions. We found that rockwalls that have been free of glacier ice since ∼10 ka experienced higher Holocene-averaged erosion rates compared to recent erosion rates. Our modelling suggests this relates to periods of higher intensities of frost cracking and cycles of permafrost aggradation and degradation in the Holocene, relative to today. For a recently deglaciated high-elevation rockwall, erosion rates were 1–2 orders of magnitude greater than the lower-elevation sites, but decayed rapidly over time since deglaciation. A high, but rapidly decaying rate results from short-lived paraglacial adjustment, permafrost thaw and high frost cracking activity. Our findings suggest that periglacial activity strongly influences the rates and patterns of erosion of deglaciated alpine rockwalls. This helps to explain why paleo Holocene deglaciated rockwall erosion rates tend to exceed recent rates in the European Alps.

Study of Using Quartz Powder as a Mineral Admixture to Produce Magnesium Oxysulfate Cement

Magnesium oxysulfate (MOS) cement features potential advantages, including light weight, green and environmental protection, low thermal conductivity, and high frost- and fire-resistance, but its poor mechanical strength limits the extensive utilization in the architectural engineering. In this study, low-cost quartz (Q) was used as a mineral admixture to increase the mechanical strength of MOS pastes. The impact of the filler Q on the early and later mechanical strength of MOS cement was investigated, in which also had an impact on fluidity, setting times, volume stability, hydration processes, phase transformations, and microstructure. The results show that hydration of periclase to form 5Mg(OH)2·MgSO4·7H2O (phase 5-1-7) in this system was a multi-stage reaction process. 3Mg(OH)2·MgSO4·8H2O was the first sediment in this system and was converted into phase 5-1-7. The dilution and dispersion effects of the filler Q increased the early hydration rate, shortened the setting time, and increased the content and crystallite size of phase 5-1-7, increasing the early mechanical strength of MOS cement, while the volume-filling effect of the filler Q reduced the content of large pore and total pore volume, and improved the pore structure of the MOS cement, improving the later mechanical strength of MOS cement. MOS cement containing 15 wt.% of filler Q exhibited the highest early and later mechanical strength, and the lowest volume shrinkage, which is more suitable for application in architectural engineering. Based on these results, filler Q can be used as an enhancer in MOS cement, however its enhancement mechanisms are effective only when the content of filler Q is no more than 20 wt.%.

An Experimental Study on the Properties of Concrete and Fiber-Reinforced Concrete in Rigid Pavements.

The complex effect of the amount of cement, polypropylene fiber (the fiber length was 39 mm, and the diameter was 0.45 mm), and polycarboxylate superplasticizer on concrete properties for rigid pavement was determined using the methods of experiment planning and experimental-statistical modeling. The fluidity of all the mixtures was S1. The W/C of the mixtures depended on the composition of the concrete and variable from 0.32 to 0.46. It was found that, by increasing the amount of superplasticizer from 1% to 1.8-2%, the compressive strength of concrete increased by 4.5-6 MPa after 3 days and by 7-9 MPa after 28 days. The flexural strength in this case increased by 0.6-0.9 MPa. The use of polypropylene fiber in the amount of 1.5-1.8 kg/m3 increased the compressive strength of concrete by an average of 3 MPa, increased the flexural strength by 0.5-0.6 MPa, reduced the abrasion capacity by 9-14%, and increased the frost resistance by up to 50 cycles. When using a rational amount of superplasticizer and fiber, the compressive strength of concrete, even with a minimum cement amount of 350 kg/m3, was at least 65 MPa, its flexural strength was at least 6 MPa, its frost resistance was F200, and its abrasion capacity was not more than 0.30 g/cm2. Concrete with such properties can be used for roadways of any type. Low abrasion capacity and high frost resistance provide the necessary durability of concrete for rigid pavement during operation.

Frost Tolerances of Turkish Olive (Olea europaea L.) Cultivars

The motherland of the olive is considered as east of the Mediterranean Basin. Turkey is partly located within this basin having a rich source of biodiversity. Olive growing in Turkey is carried out in the Aegean, Marmara, Mediterranean, Southeastern Anatolia and Black Sea Regions. Climatic factors determine the cultivation limits of olive which is not very selective in terms of soil demand. In regions where olives are grown, the Mediterranean climate prevails. Winters are warm and rainy in the region, while summers are hot and dry. On the other hand, severe cold damage in some years can cause significant damage especially in the inner parts of Aegean, Marmara and Black Sea Regions. As a matter of fact, it is known that 31.8% of olive plantations in Turkey are exposed to occasional frost damage. This situation has revealed the necessity of determining the varieties with high frost tolerance and determining the suitable varieties for the regions where cold damage may occur. In the study, 40 registered olive cultivars in “Kemalpaşa Olive Germplasm Bank" in Bornova Olive Research Institute, in İzmir were screened in terms of frost tolerance. To evaluate the frost tolerance (LT50) of cultivars, as estimated by ion leakage (electrical conductivity), leaf samples taken in six different periods over two years were exposed to temperatures at +4 °C (control), -2 °C, -5°C, -8 °C, -11°C, -14 °C, -17 °C and -20 °C. In conclusion; it has been determined that frost tolerance of olive varieties revealed significant variability both genetically and seasonally. Butko, Memeli, Otur, Gemlik, Sinop No 5, Yün Çelebi, Kara Yaprak, Satı and Sarı Ulak were determined as cultivars that were more tolerant of frost. Sinop No 1, Marantelli, Ayvalık, Görvele, Çakır, Samsun Tuzlamalık, Erkence, Saurani, Eşek Zeytini (Tekirdağ), Kan Çelebi, İzmir Sofralık, Çilli, Samsun Yağlık, Domat, Eşek Zeytini (Ödemiş), Saçaklı Otur, Sinop No 4, Memecik, Nizip Yağlık, Tekirdağ Çizmelik and Patos were found to be moderately tolerant cultivars while Edincik, Sinop No 6, Çekişte, Mavi, Kiraz, Kilis Yağlık, Çelebi (İznik), Trabzon Yağlık, Uslu and Girit olive cultivars were grouped as cultivars having low tolerance to frost. In addition, data showed that cold acclimation in the olive is quite important, and exposure to low temperatures for a certain period of time has significantly increased the frost tolerance. However, this condition was not stable and could rapidly become reversed when temperature reached to the point at which adapdation did not ensure.

Selection Effect of Liquid Nitrogen Freeze-Thaw Cycles on Full Pore Size Distribution of Different Rank Coals.

In China, the capacity to produce coalbed methane and extract underground gas is restricted by the prevalence of low-permeability coal seams. Liquid nitrogen fracturing is a new low temperature-high-pressure anhydrous fracturing technology that uses low temperature and high frost heave forces to increase coal permeability. To better understand the liquid nitrogen fracturing effect on coal, we conduct the liquid nitrogen freeze-thaw cycle (LNCFT) experiments on different rank coals from Qinghai, Shanxi, and Shaanxi provinces. We combined the low-pressure nitrogen and carbon dioxide adsorption experiment with the non-local density functional theory model and mercury injection porosimetry with compressibility corrections to examine the full pore size distributions of untreated and water-saturated samples before and after LNCFT. The results found that LNCFT can effectively increase the pore volume (PV) and specific surface area of the water-saturated coal sample. Compared with the raw coal, the increased ratio of the full pore size PV is 70.41-100.17%. However, the scale-selective transformation effect on pores during liquid nitrogen fracturing is noticeable. Under the same conditions, LNCFT can significantly increase the pore volume of micropores (>2 nm) and macropores (>50 nm), and the increase ratios are 24.40-44.16 and 103.55-327.93%, respectively. The PV of mesopores (2-50 nm) shows a slightly increasing trend with the increase in metamorphic degree, and the increase ratio is between 8.7 and 56%. Comparing the full pore size distribution curves before and after LNCFT, it is found that the alteration of high-volatile bituminous coal (BLT coal) and anthracite (SH coal) has more significance in the range of less than 2 and 50-20,000 nm, while middle-volatile bituminous coal (YJL coal) varies between 50 and 2000 nm. Meanwhile, the ratio of micropore and mesopore PV to the total decreased gradually before and after LNCFT, while the proportion of macropores increased, indicating that small-scale pores would intersect and connect to form larger-scale pores during the fracturing. The combined effects of temperature gradient, water-ice phase transition, and heat transmission rate are the key factors that determine the impact of LNCFT on pore size distribution. Our results provide new information for enhancing the permeability of low-permeability coal seams of different ranks.

Effect of Municipal Solid Waste Slag on the Durability of Cementitious Composites in Terms of Resistance to Freeze-Thaw Cycling.

The article presents durability results for cement mortars made with the addition of slag from municipal waste incineration plants as a replacement for natural aggregate. The undertaken durability tests included frost resistance tests and evaluation of strength, microstructure, water absorption and abrasiveness before and after 150 freeze-thaw cycles. The work reveals that MSWI slag in amounts up to 50 vol. % caused deterioration in the workability and water absorption of cement mortars, regardless of the type of cement used. This, in turn, resulted in a reduction in the compressive and flexural strengths of the composites compared to mortars made with sand alone. Nevertheless, the use of a higher grade of cement, CEM I 52.5 R, resulted in an increase in compressive strength and thus increased the mortars' frost and abrasion resistance. In addition, after the induced freeze-thaw cycles, mortars made with MSWI slag showed comparable or higher frost and abrasion resistance than those made using natural aggregate.

Studying varieties of winter durum wheat in interstation test on economic and valuable features

The purpose of the research was to identify sources of economically valuable traits of winter durum wheat for their further use in the breeding process. The material for the research was 53 varieties of winter durum wheat of various ecological origins: Federal State Budgetary Scientific Institution, Agrarian Research Center “Donskoy”, Federal State Budgetary Scientific Institution “National Grain Center named after P.P. Lukyanenko”, Federal State Budgetary Scientific Institution “North Caucasian Federal Scientific Agrarian Center” (Russia) and Selective Genetic Institute (Ukraine). High frost resistance characterized the following varieties: Helios (90.9%), Bosphor (91.1%), Lakomka (92.2%), Terra (92.9%), Amazonka (93.0%), Aksinit (94.6 %), Cyprida (95.4%). The sources of early ripeness were varieties: Diona, Krucha, Donskoy yantar, Helios, Continent, etc., heading, which was noted from May 20 to 22; short stems: Kurant (77.4 cm), Diona (83.6 cm), Donskoy yantar (84.2 cm), Aqueduct (84.9 cm), Zhivitsa (84.6 cm), Continent (85.1 cm) , Laska (85.1 cm); coarse grains: Yakhont, Lakomka (40.3 g), Krucha (41.2 g), Belka (41.5 g), Siniora (41.6 g), Odari (43.0 g), Continent (43.2 g ), Bella (44.5 g), Bosphor (45.3 g); high productivity: Amazonka (8.86 t/ha), Yakhont (8.90 t/ha), Lakomka (9.60 t/ha), Donskoy yantar (8.87 t/ha), Krupinka (9.20 t / ha), Belka (9.21 t/ha), Siniora (9.24 t/ha), Gavan (9.28 t/ha), Citrina (9.65 t/ha), etc. Identified genotypes of valuable traits and properties can contribute to the implementation of breeding programs to create varieties of winter durum wheat.

Productivity and resistance to stress factors of winter wheat varieties bred by ARC “Donskoy”

The purpose of the research is to evaluate modern varieties of winter soft wheat bred by the Federal State Budgetary Scientific Institution Agrarian Research Center “Donskoy” (ARC “Donskoy”) in terms of yield, elements of its structure and resistance to bio and abiotic stress factors. On average, over the years of the study (2019–2021), the yield of winter soft wheat varieties bred by the Federal State Budgetary Scientific Institution ARC “Donskoy” for the predecessor maize for grain changed from 6.33 t/ha for the Don 107 standard to 7.23 t/ha for the new varieties Flagman. Reliable yield increases in all years of the study were formed by the following varieties: Volny Don (+0.61 t/ha; +0.70 t/ha; +0.39 t/ha), Region 161 (+0.67 t/ha; +0.41 t/ha; +0.41 t/ha) and Flagman (+0.57 t/ha, +0.99 t/ha; +1.14 t/ha). An analysis of the correlation relationships between the yield of winter soft wheat varieties with elements of its structure showed that productivity in the conditions of 2019–2021 the following indicators had the maximum influence: productive bushiness (r=0.27±0.15), weight of 1000 grains (r=0.32±0.14) and density of productive stems (r=0.45±0.10). High frost resistance was noted in such varieties as Zhavoronok (74.4%), Region 161 (84.2%) and Aksai (70.5%). According to the results of the correlation analysis of yield with resistance to bio and abiotic environmental factors, no significant relationships were found. This indicates the possibility of combining high productivity and resistance to the studied stress factors in one genotype.

Non‐uniform changes of growing conditions for sweet cherry trees responses to climate warming in main production regions of China

AbstractGiven the strong sensitivity of sweet cherry trees to air temperature and the foreseeable warming under future climates, it becomes urgent to analyse spatiotemporal variability of growing conditions in main production areas of China. Here, we estimated changes of three climate metrics, that is, winter chill, heat accumulation and the risk of spring frost events, by using 22 global climate models over the historical and future (represented by central years 2050s and 2085s) time stages. Statistically downscaled daily maximum and minimum temperatures at 14 sites under representative concentration pathway (RCP) 4.5 and 8.5 scenarios were used. The results show a general increase of available winter chill for most sites in Bohai and Lanzhou–Lianyungang Railway line agro‐climatic zones, and the increase in chill accumulation could reach up to 15.2% in these regions for RCP4.5 by 2085 s. However, the most dramatic winter chill decrease is projected to occur in the southwest region under the RCP8.5 scenario by 2085 s. Additionally, the increase rate of heat accumulation during the forcing period shows spatially consistency, and the most pronounced increase is found in the RCP8.5 by 2085 s. In the north region, median heat accumulation increases by 17.5%–21.0% in the 2050 s under RCP4.5. Similar increasing range could be found in the southwest station. High frost risk areas are found in the southwestern region for both baseline and future climate scenarios. Across the 14 study sites, Mengzi and Kunming have the highest meteorologically defined risk of spring damaging frost with accumulated 335 growing degree days (GDDs) and 264 GDDs before the last spring frost event, respectively. Overall, this study provides projected characteristics of site‐specific growing conditions for sweet cherry trees in main production regions. The results could be useful for decision‐making such as selection of appropriate species and varieties in adapting to future warming.