THE STUDY OF STRUCTURAL CHANGES IN MINERALS WITH A DECREASE IN THE SIZE OF THEIR PARTICLES DURING THE RAW MATERIALS PROCESSING BY COMPUTER MODELLING OF THE LIQUID-NANO-SIZE PARTICLE SYSTEM

2017 ◽  
pp. 446-454
Author(s):  
S.P. Ostapenko ◽  
S.P. Mesyats
Keyword(s):  
Structural Changes ◽  
Computer Modelling ◽  
Particle System ◽  
Raw Materials ◽  
Materials Processing ◽  
Size Particle ◽  
Nano Size

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 In particular, the problems of livestock development (outdated technologies and production techniques that reduce the efficiency and productivity; inefficiency of the organization of purchase and processing of meat, which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”.

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

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.

scholarly journals Mechanical Properties of Chitosan-Starch Composite Filled Hydroxyapatite Micro- and Nanopowders

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Jafar Ai ◽  
Mostafa Rezaei-Tavirani ◽  
Esmaeil Biazar ◽  
Saeed Heidari K ◽  
Rahim Jahandideh
Keyword(s):  
Sol Gel ◽  
Weight Ratio ◽  
Tensile Modulus ◽  
Mechanical Analysis ◽  
Sem Images ◽  
Chitosan Hydrogel ◽  
Size Particle ◽  
Average Size ◽  
Hard Tissue Engineering ◽  
Nano Size

Hydroxyapatite is a biocompatible ceramic and reinforcing material for bone implantations. In this study, Starch-chitosan hydrogel was produced using the oxidation of starch solution and subsequently cross-linked with chitosan via reductive alkylation method (weight ratio (starch/chitosan): 0.38). The hydroxyapatite micropowders and nanopowders synthesized by sol-gel method (10, 20, 30, 40 %W) were composited to hydrogels and were investigated by mechanical analysis. The results of SEM images and Zetasizer experiments for synthesized nanopowders showed an average size of 100 nm. The nanoparticles distributed as uniform in the chitosan-starch film. The tensile modulus increased for composites containing hydroxyapatite nano-(size particle: 100 nanometer) powders than composites containing micro-(size particle: 100 micrometer) powders. The swelling percentage decreased for samples containing hydroxyapatite nanopowder than the micropowders. These nanocomposites could be applied for hard-tissue engineering.

DETERMINATION OF OPTIMAL PARAMETERS OF STABILIZATION OF SYMBIOTIC CONSORTIUM USED FOR FRUIT RAW MATERIALS PROCESSING

2021 ◽  
pp. 199-205
Author(s):  
Maria Vladimirovna Samoylenko ◽  
Maria Vladimirovna Babakina ◽  
Anastasia Valerievna Sverdlichenko ◽  
Leonidovna ZolotavinaMaria
Keyword(s):  
Raw Materials ◽  
Materials Processing ◽  
Optimal Parameters

Effect of the Spray-Atomization Characteristics on the Nano Size Particle Exhaust Emissions Characteristics Using Biodiesel-Bioethanol Blended Fuels in a DI Diesel Engine With Common Rail Injection System

2009 ◽  
Author(s):  
Su Han Park ◽  
Seung Hyun Yoon ◽  
Hyung Jun Kim ◽  
Chang Sik Lee
Keyword(s):  
Particle Number ◽  
Cone Angle ◽  
Biodiesel Fuel ◽  
Spray Atomization ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Size Particle ◽  
Blended Fuel ◽  
Blended Fuels ◽  
Nano Size

The purpose of this work is to investigate the spray-atomization, combustion and emissions characteristics of biodiesel-bioethanol (BE) and biodiesel-diesel (BD) blended fuels compared with an undiluted biodiesel fuel. For studying the overall spray characteristics, the spray tip penetration, spray cone angle were analyzed from the spray images, and droplet size and distribution were analyzed from the droplet measuring system. In addition, the combustion and exhaust emissions characteristics including the nano-size particle number and size distribution of particulate matter were studied using the direct injection diesel engine with a single cylinder. In this investigation, it revealed that BE and BD blended fuels have slightly higher spray tip penetration and wider spray cone angle due to the reduction of fuel properties such as fuel density and kinematic viscosity. Fuel droplet sizes of blended fuels were distributed in the region of the lower diameter size, compared to biodiesel fuel. It can be said that the reduced fuel viscosity and surface tension of blended fuels affect the atomization performance of biodiesel fuel. The experimental results of spray characteristics were compared with the predicted results through the numerical method by the KIVA-3V. On the other hand, BD blended fuel has a similar combustion and emission characteristics compared with an undiluted biodiesel fuel. In case of BE blended fuel, the ignition delay becomes longer and the rate of heat release becomes high. In the case of exhaust emission characteristics of BE blended fuel, it has lower soot emission, contrary to the almost same nitrogen oxides, hydrocarbon, and carbon monoxide. In the analysis of particle size and number distribution, the number and size distribution of B100 and BD20 fuels have a similar pattern and value. However, BE blended fuel has a lowest particle number in the region of nuclei mode. Moreover, the increase of the injection pressure affects the increase of the smaller size particle of BE blended fuel.

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