scholarly journals SONOCHEMICAL PROCESSING INDUSTRIAL AND BIOLOGICAL МАТЕRIALS

2021 ◽  
pp. 79-94
Author(s):  
Ярослав Олегович Шабловский
Keyword(s):  
Grain Size ◽  
Heterogeneous Reaction ◽  
Quantitative Characteristic ◽  
Extreme Case ◽  
Dense Phase ◽  
Wave Regime ◽  
Sediment Grain Size ◽  
Reaction Systems ◽  
Qualitative And Quantitative ◽  
Characteristic Features

Проанализированы технологически значимые факторы, обеспечивающие возможности управления сонохимическими процессами. Выявлены качественные и количественные закономерности влияния акустических воздействий на химические процессы в гомогенных и в гетерогенных реакционных системах. Показано, что сонохимический эффект может быть не только положительным (инициирование химической реакции), но и отрицательным (подавление реакции). Соответственно, в экстремальном случае возможен сонохимический резонанс (максимум эффективности акустического воздействия) либо сонохимический антирезонанс (минимум эффективности акустического воздействия). Акустическая обработка конденсированных сред в режиме стоячей волны позволяет контролировать характерный размер частиц плотных фракций: укрупнять частицы кристаллического осадка (соноиндуцированный эффект Тананаева) либо, наоборот, измельчать плотную фазу без использования мелющих тел. The paper deals with technologically essential factors governing sonochemical processes. Qualitative and quantitative characteristic features of sonoinduced chemical processes in homogeneous and heterogeneous reaction systems are revealed and discussed. A sonochemical effect can be either positive (promoting a reaction) or negative (suppressing a reaction). In an extreme case a sonochemical resonance or a sonochemical antiresonance can occur. Ultrasonic processing condensed media in a standing-wave regime enables to control the grain size of dense fractions. Namely, the sediment grain size can be enhanced (Tananayev sonoinduced effect) or, vice versa, a dense phase can be comminuted without grinding.

scholarly journals Soil fungi communities from young Scots pine plantations affected with root rot

2013 ◽  
Vol 42 (2) ◽  
pp. 239-244 ◽  
Author(s):  
Wojciech Szewczyk
Keyword(s):  
Scots Pine ◽  
Root Rot ◽  
Soil Fungi ◽  
Quantitative Characteristic ◽  
Pine Plantations ◽  
Tree Roots ◽  
Qualitative And Quantitative ◽  
Pine Stands ◽  
Characteristic Features ◽  
Forest District

The aim of work was to investigate the qualitative and quantitative characteristic features of soil fungi associations occurring in I class pine stands threatened by pathogens of tree roots in Zielonka Experimental Forest District. During the mycological analyses of soil, a total of 694 isolates of fungi representing 33 species were obtained. The most numerously represented species was <em>Penicillium daleae</em> which made 75% of all isolates. The second place in the ranking belonged to <em>Penicillium janczewski</em> amounting to 11%. In order to define the qualitative and quantitative similarity between the studied areas, a proportional inconformity was determined. The greatest similarity occurred between the associations of soil fungi obtained from site 64c and 35b.

scholarly journals Holocene Key-Marker Tephra Layers in Kamchatka, Russia

1997 ◽  
Vol 47 (2) ◽  
pp. 125-139 ◽  
Author(s):  
Olga A. Braitseva ◽  
Vera V. Ponomareva ◽  
Leopold D. Sulerzhitsky ◽  
Ivan V. Melekestsev ◽  
John Bailey
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Mineral Composition ◽  
Kamchatka Peninsula ◽  
Explosive Eruptions ◽  
Shiveluch Volcano ◽  
Stratigraphic Position ◽  
Tephra Layers ◽  
Characteristic Features ◽  
Important Marker

Detailed tephrochronological studies in Kamchatka Peninsula, Russia, permitted documentation of 24 Holocene key-marker tephra layers related to the largest explosive eruptions from 11 volcanic centers. Each layer was traced for tens to hundreds of kilometers away from the source volcano; its stratigraphic position, area of dispersal, age, characteristic features of grain-size distribution, and chemical and mineral composition confirmed its identification. The most important marker tephra horizons covering a large part of the peninsula are (from north to south; ages given in14C yr B.P.) SH2(≈1000 yr B.P.) and SH3(≈1400 yr B.P.) from Shiveluch volcano; KZ (≈7500 yr B.P.) from Kizimen volcano; KRM (≈7900 yr B.P.) from Karymsky caldera; KHG (≈7000 yr B.P.) from Khangar volcano; AV1(≈3500 yr B.P.), AV2(≈4000 yr B.P.), AV4(≈5500 yr B.P.), and AV5(≈5600 yr B.P.) from Avachinsky volcano; OP (≈1500 yr B.P.) from the Baraniy Amfiteatr crater at Opala volcano; KHD (≈2800 yr B.P.) from the “maar” at Khodutka volcano; KS1(≈1800 yr B.P.) and KS2(≈6000 yr B.P.) from the Ksudach calderas; KSht3(A.D. 1907) from Shtyubel cone in Ksudach volcanic massif; and KO (≈7700 yr B.P.) from the Kuril Lake-Iliinsky caldera. Tephra layers SH5(≈2600 yr B.P.) from Shiveluch volcano, AV3(≈4500 yr B.P.) from Avachinsky volcano, OPtr(≈4600 yr B.P.) from Opala volcano, KS3(≈6100 yr B.P.) and KS4(≈8800 yr B.P.) from Ksudach calderas, KSht1(≈1100 yr B.P.) from Shtyubel cone, and ZLT (≈4600 yr B.P.) from Iliinsky volcano cover smaller areas and have local stratigraphic value, as do the ash layers from the historically recorded eruptions of Shiveluch (SH1964) and Bezymianny (B1956) volcanoes. The dated tephra layers provide a record of the most voluminous explosive events in Kamchatka during the Holocene and form a tephrochronological timescale for dating and correlating various deposits.

scholarly journals Centennial Impacts of the East Asian Summer Monsoon on Holocene Deltaic Evolution of the Huanghe River, China

2021 ◽  
Vol 11 (6) ◽  
pp. 2799
Author(s):  
Yanping Chen ◽  
Wenzhe Lyu ◽  
Tengfei Fu ◽  
Yan Li ◽  
Liang Yi
Keyword(s):  
Grain Size ◽  
Yellow River ◽  
Asian Summer Monsoon ◽  
River Delta ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Sediment Grain Size ◽  
Huanghe River ◽  
Huanghe River Delta ◽  
The Huanghe River

The Huanghe River (Yellow River) is the most sediment laden river system in the world, and many efforts have been conducted to understand modern deltaic evolution in response to anthropological impacts. However, the natural background and its linkage to climatic changes are less documented in previous studies. In this work, we studied the sediments of core YDZ–3 and marine surface samples by grain-size analysis to retrieve Holocene dynamics of the Huanghe River delta in detail. The main findings are as follows: The mean value of sediment grain size of the studied core is 5.5 ± 0.9 Φ, and silt and sand contents are 5.2 ± 2.3% and 8.2 ± 5.3%, respectively, while the variance of clay particles is relatively large with an average value of 86.4 ± 8.5%. All grain-size data can be mathematically partitioned by a Weibull-based function formula, and three subgroups were identified with modal sizes of 61.1 ± 28.9 μm, 30.0 ± 23.9 μm, and 2.8 ± 1.6 μm, respectively. There are eight intervals with abrupt changes in modal size of core YDZ–3, which can be correlated to paleo-superlobe migration of the Huanghe River in the Holocene. Based on these observations, the presence of seven superlobes in the history are confirmed for the first time and their ages are well constrained in this study, including Paleo-Superlobes Lijin (6400–5280 yr BP), Huanghua (4480–4190 yr BP), Jugezhuang (3880–3660 yr BP), Shajinzi (3070–2870 yr BP), Nigu (2780–2360 yr BP), Qikou (2140–2000 yr BP), and Kenli (1940–1780 and 1700–1650 yr BP). By tuning geomorphological events to a sedimentary proxy derived from core YDZ–3 and comparing to various paleoenvironmental changes, we proposed that winter climate dominated Holocene shifts of the Huanghe River delta on millennial timescales, while summer monsoons controlled deltaic evolution on centennial timescales.

East Asian winter monsoon variation during the last 3000 years as recorded in a subtropical mountain lake, northeastern Taiwan

The Holocene ◽  
2021 ◽  
pp. 095968362110190
Author(s):  
Tsai-Wen Lin ◽  
Stefanie Kaboth-Bahr ◽  
Kweku Afrifa Yamoah ◽  
André Bahr ◽  
George Burr ◽  
...  
Keyword(s):  
Grain Size ◽  
East Asian Winter Monsoon ◽  
East Asian ◽  
Winter Monsoon ◽  
Mountain Lake ◽  
Sediment Grain Size ◽  
Global Monsoon ◽  
Asian Winter Monsoon ◽  
The Past ◽  
Monsoon System

The East Asian Winter Monsoon (EAWM) is a fundamental part of the global monsoon system that affects nearly one-quarter of the world’s population. Robust paleoclimate reconstructions in East Asia are complicated by multiple sources of precipitation. These sources, such as the EAWM and typhoons, need to be disentangled in order to understand the dominant source of precipitation influencing the past and current climate. Taiwan, situated within the subtropical East Asian monsoon system, provides a unique opportunity to study monsoon and typhoon variability through time. Here we combine sediment trap data with down-core records from Cueifong Lake in northeastern Taiwan to reconstruct monsoonal rainfall fluctuations over the past 3000 years. The monthly collected grain-size data indicate that a decrease in sediment grain size reflects the strength of the EAWM. End member modelling analysis (EMMA) on sediment core and trap data reveals two dominant grain-size end-members (EMs), with the coarse EM 2 representing a robust indicator of EAWM strength. The downcore variations of EM 2 show a gradual decrease over the past 3000 years indicating a gradual strengthening of the EAWM, in agreement with other published EAWM records. This enhanced late-Holocene EAWM can be linked to the expansion of sea-ice cover in the western Arctic Ocean caused by decreased summer insolation.

Relationships between multibeam backscatter, sediment grain size and Posidonia oceanica seagrass distribution

2010 ◽  
Vol 30 (18) ◽  
pp. 1941-1950 ◽  
Author(s):  
Giovanni De Falco ◽  
Renato Tonielli ◽  
Gabriella Di Martino ◽  
Sara Innangi ◽  
Simone Simeone ◽  
...  
Keyword(s):  
Grain Size ◽  
Posidonia Oceanica ◽  
Sediment Grain Size

scholarly journals Remote sensing of underwater vegetation using single-beam acoustics

2009 ◽  
Vol 67 (3) ◽  
pp. 594-605 ◽  
Author(s):  
Victor Quintino ◽  
Rosa Freitas ◽  
Renato Mamede ◽  
Fernando Ricardo ◽  
Ana Maria Rodrigues ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Grain Size ◽  
Algal Biomass ◽  
Sediment Grain Size ◽  
Coastal System ◽  
Single Beam ◽  
Acoustic Data ◽  
Sediment Types ◽  
Caulerpa Prolifera ◽  
Sandy Sediments

Abstract Quintino, V., Freitas, R., Mamede, R., Ricardo, F., Rodrigues, A. M., Mota, J., Pérez-Ruzafa, Á., and Marcos, C. 2010. Remote sensing of underwater vegetation using single-beam acoustics. – ICES Journal of Marine Science, 67: 594–605. A single-beam, acoustic, ground-discrimination system (QTC VIEW, Series V) was used to study the distribution of underwater macrophytes in a shallow-water coastal system, employing frequencies of 50 and 200 kHz. The study was conducted in Mar Menor, SE Spain, where the expansion of Caulerpa prolifera has contributed to the silting up of the superficial sediments. A direct relationship was identified between algal biomass and sediment-fines content. Acoustic information on sediment grain size and data on algal biomass were obtained in muddy and sandy sediments, including vegetated and non-vegetated seabed. Non-vegetated muddy areas were created by diving and handpicking the algae. The multivariate acoustic data were analysed under the null hypotheses that there were no acoustic differences between bare seabeds with contrasting superficial sediment types or among low, medium, and high algal-biomass areas, having in mind that grain size can act as a confounding factor. Both null hypotheses were rejected, and the results showed that 200 kHz was better than 50 kHz in distinguishing cover levels of algal biomass. The relationship between the 200-kHz acoustic data and algal biomass suggests utility in modelling the latter using the former.

scholarly journals Modelling of Pollution Transport with Sediment on the Example of the Widawa River

2013 ◽  
Vol 39 (2) ◽  
pp. 29-43 ◽  
Author(s):  
Robert Kasperek ◽  
Marian Mokwa ◽  
Mirosław Wiatkowski
Keyword(s):  
Grain Size ◽  
Cross Sections ◽  
Sample Volume ◽  
Industrial Wastes ◽  
Phosphorus Concentration ◽  
Pollution Transport ◽  
Sediment Grain Size ◽  
Run Off ◽  
Odra River ◽  
Geochemical Analyses

Abstract The aim of the study was to determine the contamination transport condition with sediment in the Widawa River, which inflows to the Odra River below Wrocław city. The transport simulations have been performed by means of HEC-RAS model, which was calibrated. Study and geochemical analyses indicate that pollutions are cumulated mainly in sediment of grain size, less than 0,20 mm. It was stated that the main sources of contaminations occurring in the Widawa River bottoms are: superficial run-off, municipal and industrial wastes. Sediment bed quality from the Widawa River in selected cross-sections has been analyzed. Samples of suspended load were collected and divided into eight fractions, for which the phosphorus concentration P was calculated. Deposit particles less than 0,20 mm contained most phosphorus, i.e. 73% (3,52 ppm), and particles greater than 0,20 mm about 27% (1,30 ppm) for the whole sample volume. Relationship between the phosphorus concentration P and the sediment grain size was determined. Analysis showed that the initiation of contamination-sediment suspension in the Widawa River is well described by Engelund criterion. Simulations of the migration of pollutions together with deposits in the Widawa River showed that during average flow discharge, the transport intensity of pollution was equal 2 mg/s, and sediments 6 kg/s. In the present work the water quality of the Widawa River has been also presented.

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