Microstructure of Lightweight and Decorative Renders with Modified Composition

2015 ◽  
Vol 1100 ◽  
pp. 142-146
Author(s):  
Jiří Bydžovský ◽  
Tomáš Melichar ◽  
Nikol Žižková
Keyword(s):  
Structural Changes ◽  
Raw Materials ◽  
Mechanical Tests ◽  
Short Term ◽  
Aggregate Fractions

Within the research presented in this article the attention was paid to the study of microstructure of lightweight and decorative renders. The composition of these renders was modified using alternative raw materials in amount of 5 % substituting the finest aggregate fractions. For evaluation of microstructure and its changes the combination of three methods SEM, XRD and DTA was used. Samples for the analysis were prepared from 90-day old specimens. The reason was the evaluation of material structural changes within the mid-term scale because considering the character and amount of used raw materials including the results of physical-mechanical tests no more significant changes were assumed in a short-term period. The performed analyses showed only inessential changes in microstructure of modified materials in comparison with the results of physical-mechanical tests.

Ukraine’s foreign trade in meat and meat products: trends and geographical aspects

2020 ◽  
pp. 48-52
Author(s):  
Olena Lyakhovska
Keyword(s):  
Small Businesses ◽  
Structural Changes ◽  
Raw Materials ◽  
Meat Products ◽  
World Market ◽  
Poultry Meat ◽  
Positive Development ◽  
Meat Production ◽  
Meat Industry ◽  
Geographical Structure

Current trends in meat and meat products exports are considered. The dynamics and structural changes in meat exports by types and degree of processing (beef and veal, pork, poultry, finished meat products) are analyzed. The paper proves that in recent years, only meat and edible poultry by-products have taken a competitive position in the world market. Accordingly, the dynamics of exports of this type of meat is positive, and the share of these products in the structure of exported meat is the largest (86.09%). Possible threats to the growth of import dependence on certain types of meat products, in particular, chilled and frozen beef and veal, pork, are indicated. The rating of the largest countries-importers of meat and meat products (by types) from Ukraine is built, their share in the structure of meat exports is determined. Changes in the geographical structure of exports have been studied, which indicate a low level of diversification of the geography of exports of certain types of meat (pork, beef). At the same time, a positive development of the geographical structure of poultry meat exports (exported to more than 100 countries) was revealed. Problems of the export potential development in the meat industry of Ukraine are revealed. In particular, the problems of livestock development (outdated technologies and production techniques that reduce the efficiency and productivity; inefficiency of the organization of purchase and processing of meat, which leads to reduced breeding in small businesses and households; inefficiency of state incentives, etc.) and industrial meat production (lack of raw materials, obsolescence of fixed assets and production technologies, poorly developed logistics, etc.). The solution of these problems requires: a systematic approach, which will encourage the cooperation of agricultural and industrial production, cooperation with importers of meat products and protection of domestic producers in the domestic and international markets, creating a favorable investment and information environment that will promote the meat industry development.

scholarly journals Alkali-Hydrothermal Treatment of K-Rich Igneous Rocks for Their Direct Use as Potassic Fertilizers

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 140
Author(s):  
Aaron Mbissik ◽  
Abdellatif Elghali ◽  
Muhammad Ouabid ◽  
Otmane Raji ◽  
Jean-Louis Bodinier ◽  
...  
Keyword(s):  
Hydrothermal Treatment ◽  
Inductively Coupled Plasma ◽  
Structural Changes ◽  
Raw Materials ◽  
Hydrothermal Process ◽  
Atomic Emission ◽  
Igneous Rocks ◽  
Gravimetric Analysis ◽  
African Countries ◽  
Naoh Solution

Due to the increasing demand for conventional sources of potassium (K) and their inaccessibility by African countries, K-rich igneous rocks are increasingly studied as potential alternative sources. In this study, six potassic igneous rocks (syenites and trachytes) from the Tamazeght, Jbel Boho, Ait Saoun, and El Glo’a regions (Morocco) were sampled and characterized. Then they were hydrothermally treated to enhance their K release for potential use as potassic fertilizers. The raw materials are mainly formed by microcline (up to 74%), orthoclase (20–68%), albite (36–57%), biotite-muscovite (15–23%), and titanite, calcite, hematite, and apatite as accessory minerals. These samples were crushed and milled to reach a particle size <150 µm and mixed with 4 N NaOH solution in an autoclave. The liquid/solid (L/S) ratio was about 44 mL/50 g. The powders were allowed to react with the solution at 170 °C for 7 h. For all tests, NaOH reacted completely with the powders and no liquid was observed after the treatment. X-ray diffraction (XRD), thermal gravimetric analysis (TGA), infrared spectroscopy (IRTF), and scanning electron microscopy (SEM-EDS) were carried out on treated samples to characterize the mineralogical and structural changes due to the alkali-hydrothermal treatment. Indeed, the treated samples revealed the presence of sodic neoformed phases such as thermonatrite, sodalite, analcime, and cancrinite. The treated material was leached for a week using deionized water and the elements released were measured using inductively coupled plasma–atomic emission spectroscopy (ICP-AES). The hydrothermal process showed a strong effect on structure breakdown as well as on the release of K and other nutrients such as P, Fe, Si, Mg, and Ca. Therefore, the alkali-hydrothermal treatment allowed the release of 50.5 wt% K. Moreover, the release of Mg, Ca, Fe, P, K, and Si were significantly increased. Mg, Ca, Fe, P, K, and Si release within raw materials was about (0.5–3.6), (3.5–31.4), (0.01–0.4), (0.01–0.3), (20–55), and (4.6–8) mg/kg, respectively, whereas treated samples showed a higher release of these elements. Quantitatively, Mg, Ca, Fe, P, K, and Si releases were about (10–11.8), (60–70), (7–20), (1.2–15), (218–1278), and (1119–2759) mg/kg, respectively. Consequently, the treated igneous rocks (syenite and trachyte) could be directly used as potassic fertilizers that would also be a source of other nutrients.

scholarly journals The Dynamic Impacts of the COVID-19 Pandemic on Log Prices in China: An Analysis Based on the TVP-VAR Model

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 449
Author(s):  
Chenlu Tao ◽  
Gang Diao ◽  
Baodong Cheng
Keyword(s):  
Exchange Rate ◽  
Structural Changes ◽  
Raw Materials ◽  
Supply And Demand ◽  
Oil Prices ◽  
Control Measures ◽  
Var Model ◽  
Time Varying ◽  
Wood Industry ◽  
The Impact

China’s wood industry is vulnerable to the COVID-19 pandemic since wood raw materials and sales of products are dependent on the international market. This study seeks to explore the speed of log price recovery under different control measures, and to perhaps find a better way to respond to the pandemic. With the daily data, we utilized the time-varying parameter autoregressive (TVP-VAR) model, which can incorporate structural changes in emergencies into the model through time-varying parameters, to estimate the dynamic impact of the pandemic on log prices at different time points. We found that the impact of the pandemic on oil prices and Renminbi exchange rate is synchronized with the severity of the pandemic, and the ascending in the exchange rate would lead to an increase in log prices, while oil prices would not. Moreover, the impulse response in June converged faster than in February 2020. Thus, partial quarantine is effective. However, the pandemic’s impact on log prices is not consistent with changes of the pandemic. After the pandemic eased in June 2020, the impact of the pandemic on log prices remained increasing. This means that the COVID-19 pandemic has long-term influences on the wood industry, and the work resumption was not smooth, thus the imbalance between supply and demand should be resolved as soon as possible. Therefore, it is necessary to promote the development of the domestic wood market and realize a “dual circulation” strategy as the pandemic becomes a “new normal”.

scholarly journals Development of the reproduction number from coronavirus SARS-CoV-2 case data in Germany and implications for political measures

BMC Medicine ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Sahamoddin Khailaie ◽  
Tanmay Mitra ◽  
Arnab Bandyopadhyay ◽  
Marta Schips ◽  
Pietro Mascheroni ◽  
...  
Keyword(s):  
Structural Changes ◽  
Reproduction Number ◽  
National Level ◽  
Transmission Dynamics ◽  
Federal State ◽  
Parameter Estimates ◽  
Time Varying ◽  
Short Term ◽  
Robert Koch Institute ◽  
Federal States

Abstract Background SARS-CoV-2 has induced a worldwide pandemic and subsequent non-pharmaceutical interventions (NPIs) to control the spread of the virus. As in many countries, the SARS-CoV-2 pandemic in Germany has led to a consecutive roll-out of different NPIs. As these NPIs have (largely unknown) adverse effects, targeting them precisely and monitoring their effectiveness are essential. We developed a compartmental infection dynamics model with specific features of SARS-CoV-2 that allows daily estimation of a time-varying reproduction number and published this information openly since the beginning of April 2020. Here, we present the transmission dynamics in Germany over time to understand the effect of NPIs and allow adaptive forecasts of the epidemic progression. Methods We used a data-driven estimation of the evolution of the reproduction number for viral spreading in Germany as well as in all its federal states using our model. Using parameter estimates from literature and, alternatively, with parameters derived from a fit to the initial phase of COVID-19 spread in different regions of Italy, the model was optimized to fit data from the Robert Koch Institute. Results The time-varying reproduction number (Rt) in Germany decreased to <1 in early April 2020, 2–3 weeks after the implementation of NPIs. Partial release of NPIs both nationally and on federal state level correlated with moderate increases in Rt until August 2020. Implications of state-specific Rt on other states and on national level are characterized. Retrospective evaluation of the model shows excellent agreement with the data and usage of inpatient facilities well within the healthcare limit. While short-term predictions may work for a few weeks, long-term projections are complicated by unpredictable structural changes. Conclusions The estimated fraction of immunized population by August 2020 warns of a renewed outbreak upon release of measures. A low detection rate prolongs the delay reaching a low case incidence number upon release, showing the importance of an effective testing-quarantine strategy. We show that real-time monitoring of transmission dynamics is important to evaluate the extent of the outbreak, short-term projections for the burden on the healthcare system, and their response to policy changes.

STUDY OF OIL AND GAS PROSPECTIVE STRUCTURES OF THE ARAL SEA REGION WITH THE FORECAST OF THEIR RESERVES

2021 ◽  
Author(s):  
С.К. Курбаниязов
Keyword(s):  
Oil And Gas ◽  
Raw Materials ◽  
Research Work ◽  
Aral Sea ◽  
Short Term ◽  
Alluvial Deposits ◽  
Hydrocarbon Traps ◽  
Coastal Sea ◽  
Detailed Search ◽  
Gas Potential

В начале барремского времени море отступило и до начала позднего альба территория представляла собой низменную аккумулятивную равнину, в пределах которой происходило накопление аллювиальных и озерно-аллювиальных отложений: красно-коричневых глин, алевролитов с прослоями коричневых песчаников и песков и линзами темно-серого лигнита. В основании толщи отмечаются гравелиты и конгломераты. В раннемальбе произошла кратковременная трансгрессия моря, однако территория современного Восточного Приаралья не была затоплена и представляла собой прибрежно-морскую равнину, где накапливались глины, алевролиты и песчаники. К концу позднего альба море регрессировало, и территория вновь стала представлять собой низменную аллювиально-озерную равнину. По всей территории происходило накопление пестроцветных глин, зеленовато-серых алевролитов, песков и песчаников, а также углей. При проведении иследовательских работ были обоснованы наиболее перспективные типы ловушек углеводородного сырья по стратиграфическим уровням и выявлена зональность их распространения. Дана оценка перспектив района на выявление залежей нефти и газа. Выделены информативные и качественные признаки (критерии) нефтегазоносности. Обоснованы площади и конкретные структуры для постановки детальных поисковых работ на выявление залежей нефти и газа. Рассчитана оценка потенциальных ресурсов углеводородного сырья. At the beginning of the Barremian time, the sea receded and until the beginning of the late Alb, the territory was a low-lying accumulative plain, within which the accumulation of alluvial and lacustrine-alluvial deposits occurred: red-brown clays, siltstones with layers of brown sandstones and sands and lenses of dark gray lignite. Gravelites and conglomerates are noted at the base of the strata.In the Rannemalba, there was a short-term transgression of the sea, but the territory of the modern Eastern Aral Sea region was not flooded and was a coastal-sea plain, where clays, siltstones and sandstones accumulated. By the end of the Late Alb, the sea regressed and the area again became a low-lying alluvial-lacustrine plain. There was an accumulation of variegated clays, greenish-gray siltstones, sands and sandstones, as well as coals throughout the territory. During the research work, the most promising types of hydrocarbon traps were justified by stratigraphic levels and the zoning of their distribution was revealed. The assessment of the prospects of the area for the identification of oil and gas deposits is given. Informative and qualitative signs (criteria) of oil and gas potential are identified. The areas and specific structures for setting up detailed search operations to identify oil and gas deposits are justified. The estimation of potential resources of hydrocarbon raw materials is calculated.

Analytical support of the main trends in the development of the livestock industry

2020 ◽  
pp. 10-21
Author(s):  
Elena Kostyukova ◽  
Alexander Frolov
Keyword(s):  
Rural Areas ◽  
Agricultural Development ◽  
Structural Changes ◽  
Raw Materials ◽  
Animal Husbandry ◽  
Agricultural Economics ◽  
Industrial Complex ◽  
Livestock Industry ◽  
Domestic Livestock ◽  
Livestock Products

Agriculture is the most important area of economic activity for the production of products and services in order to provide the population with quality food, industry with raw materials and promote sustainable development of rural areas. In recent years, there has been a downward trend in the rate of agricultural development, which is lagging behind the growth rate of the Russian economy as a whole. Structural changes in the agro-industrial complex have not produced significant positive results, which is caused by a number of reasons. One of the directions of agricultural policy in Russia is the accelerated development of animal husbandry and increasing the competitiveness of domestic livestock products in the domestic market. The state program for the development of agriculture and regulation of markets for agricultural products, raw materials and food provides for a set of measures for the priority development of animal husbandry. Implementation of these measures requires improved management in order to increase the efficiency of livestock production. The article considers aspects of the formation of accounting and analytical support for management of the livestock industry, economic and statistical analysis of trends and structural changes in the livestock industry. The best practices of Russian scientists in the field of accounting and agricultural Economics are summarized

scholarly journals Tension mechanical properties of recycled glass-epoxy composite material

2012 ◽  
pp. 189-198 ◽  
Author(s):  
Jelena Petrovic ◽  
Darko Ljubic ◽  
Marina Stamenovic ◽  
Ivana Dimic ◽  
Slavisa Putic
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Composite Material ◽  
Composite Materials ◽  
Modulus Of Elasticity ◽  
Epoxy Composite ◽  
Raw Materials ◽  
Mechanical Tests ◽  
Recycled Glass ◽  
Before And After

The significance of composite materials and their applications are mainly due to their good properties. This imposes the need for their recycling, thus extending their lifetime. Once used composite material will be disposed as a waste at the end of it service life. After recycling, this kind of waste can be used as raw materials for the production of same material, which raises their applicability. This indicates a great importance of recycling as a method of the renowal of composite materials. This study represents a contribution to the field of mechanical properties of the recycled composite materials. The tension mechanical properties (tensile strength and modulus of elasticity) of once used and disposed glass-epoxy composite material were compared before and after the recycling. The obtained results from mechanical tests confirmed that the applied recycling method was suitable for glass-epoxy composite materials. In respect to the tensile strength and modulus of elasticity it can be further assessed the possibility of use of recycled glass-epoxy composite materials.

scholarly journals Dynamic Characterization of the Biomechanical Behaviour of Bovine Ovarian Cortical Tissue and Its Short-Term Effect on Ovarian Tissue and Follicles

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3759
Author(s):  
Giulia Pascoletti ◽  
Maddalena Di Nardo ◽  
Gionata Fragomeni ◽  
Vincenza Barbato ◽  
Teresa Capriglione ◽  
...  
Keyword(s):  
Mechanical Test ◽  
Cell Damage ◽  
Ovarian Tissue ◽  
Viscoelastic Behavior ◽  
Mechanical Tests ◽  
Cortical Tissue ◽  
Short Term ◽  
Tissue Properties

The ovary is a dynamic mechanoresponsive organ. In vitro, tissue biomechanics was reported to affect follicle activation mainly through the Hippo pathway. Only recently, ovary responsiveness to mechanical signals was exploited for reproductive purposes. Unfortunately, poor characterization of ovarian cortex biomechanics and of the mechanical challenge hampers reproducible and effective treatments, and prevention of tissue damages. In this study the biomechanical response of ovarian cortical tissue from abattoir bovines was characterized for the first time. Ovarian cortical tissue fragments were subjected to uniaxial dynamic testing at frequencies up to 30 Hz, and at increasing average stresses. Tissue structure prior to and after testing was characterized by histology, with established fixation and staining protocols, to assess follicle quality and stage. Tissue properties largely varied with the donor. Bovine ovarian cortical tissue consistently exhibited a nonlinear viscoelastic behavior, with dominant elastic characteristics, in the low range of other reproductive tissues, and significant creep. Strain rate was independent of the applied stress. Histological analysis prior to and after mechanical tests showed that the short-term dynamic mechanical test used for the study did not cause significant tissue tear, nor follicle expulsion or cell damage.

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