scholarly journals Research on the Migration of the Total Manganese during the Process of Water Icing

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1626 ◽  
Author(s):  
Yan Zhang ◽  
Yuanqing Tang ◽  
Aixin Yu ◽  
Wanli Zhao ◽  
Yucan Liu
Keyword(s):  
Lower Layer ◽  
Water System ◽  
Middle Layer ◽  
Freezing Temperature ◽  
Experimental Methods ◽  
Average Concentration ◽  
Laboratory Simulation ◽  
Ice Thickness ◽  
Ice Water ◽  
Migration Law

Our research focused on the migration law of the total manganese (TMn) during the process of water icing. We utilized two experimental methods: (1) natural icing and (2) simulated icing. While using laboratory simulation, we explored the effects of ice thickness, freezing temperature, and initial concentrations on the migration of TMn in the ice-water system. The distribution coefficient “K” (the ratio of the average concentration of TMn in the ice body to the average concentration of TMn in the under-ice water body) was used to characterize it. The results indicated that TMn continuously migrated from ice to under-ice water during the process of water icing. The concentration of TMn in the ice was the upper layer < middle layer < lower layer, and K decreases as the ice thickness, freezing temperature, and initial concentration increased. We explained the migration of TMn during the process of water icing from the perspective of crystallography. Our research can arouse other researcher’s attention towards the change of TMn concentration in lakes in high latitudes during the icebound period.

scholarly journals The Migration Law of Iron during the Process of Water Icing

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 441
Author(s):  
Yuanqing Tang ◽  
Yan Zhang ◽  
Wanli Zhao ◽  
Tongshuai Liu ◽  
Yucan Liu
Keyword(s):  
Iron Concentration ◽  
Water System ◽  
Freezing Temperature ◽  
Average Concentration ◽  
Initial Concentration ◽  
Before And After ◽  
Shallow Lakes And Ponds ◽  
Solid Liquid ◽  
Ice Water ◽  
Migration Law

In this study, we utilized simulated icing experiments to investigate the effect of icing thickness, freezing temperature and initial concentration on the migration of iron in the ice–water system during water icing. The distribution coefficient “K” (the ratio of the average concentration of iron in the ice to that in the under-ice water) was used to describe the effect. The results indicated that iron partitioned stronger to under-ice water than to ice during the process of water icing, resulting in the concentration of iron in ice–water system before and after freezing being expressed as: ice < pre-freezing water < under-ice water. K decreased with the increase in icing thickness, freezing temperature and initial concentration. The temperature change in the solution will change the solubility of the solvent, so we explained the migration of iron during the process of water icing from the perspective of solid–liquid equilibrium theory. Too high or too low iron concentration may inhibit the growth of algae, thus affecting the underwater ecological environment. We expect that our study will arouse researcher’s attention to the change in iron concentration in shallow lakes and ponds at high latitudes during the icebound period.

scholarly journals The migration law of magnesium ions during freezing and melting processes

2021 ◽  
Author(s):  
Zhang Yan ◽  
Liu Tongshuai ◽  
Tang Yuanqing ◽  
Zhao Wanli ◽  
Ren Fangyun ◽  
...  
Keyword(s):  
Water Layer ◽  
Melting Process ◽  
Freezing Temperature ◽  
Laboratory Simulation ◽  
Ice Thickness ◽  
Magnesium Ions ◽  
Initial Concentration ◽  
Ice Melt ◽  
Initial Ph ◽  
Migration Law

AbstractTo explore the migration law of magnesium ions (Mg2+) during freezing and melting processes, laboratory simulation experiments involving freezing and melting were carried out to investigate the influence of ice thickness, freezing temperature, initial concentration, and initial pH on the distribution of Mg2+ in the ice-water system. The distribution coefficient “K” (the ratio of the Mg2+ concentration in the ice layer to the Mg2+ concentration in the water layer under ice) was used to characterize the migration ability of Mg2+. The results showed that during the freezing process, the concentration distribution of Mg2+ in the ice and water two-phase system was as follows: ice layer < water before freezing < water layer under ice; in other words, it migrated from ice layer to the water layer under ice. “K” decreased with increasing ice thickness, freezing temperature, initial concentration, and initial pH; the higher the ice thickness, freezing temperature, initial concentration, and initial pH were, the higher the migration efficiency of Mg2+ into the water layer under ice was. During the melting process, Mg2+ was released in large amounts (50–60%) at the initial stage (0–25%) and in small amounts (25–100%) uniformly in the middle and later periods. According to the change of Mg2+ concentration in ice melt water, an exponential model was established to predict Mg2+ concentration in ice melt period. The migration law of Mg2+during the freezing and melting process was explained by using first principles.

scholarly journals Distribusi Vertikal Logam Pb, Zn, Cr dan Keterkaitannya Terhadap Karbon Organik Sedimen di Pantai Marunda, Jakarta

2020 ◽  
Vol 9 (2) ◽  
pp. 125-132
Author(s):  
Triyanti Nurhidayah ◽  
Lilik Maslukah ◽  
Sri Yulina Wulandari ◽  
Kurnia Kurnia
Keyword(s):  
Heavy Metals ◽  
Vertical Distribution ◽  
Lower Layer ◽  
Middle Layer ◽  
Average Concentration ◽  
Anthropogenic Activity ◽  
Sediment Texture ◽  
The Relationship ◽  
The Vertical Distribution ◽  
Very High

Pantai Marunda terletak di Teluk Jakarta dan berdekatan dengan muara Sungai Tiram. Kegiatan antropogenik di sekitar Pantai Marunda sangat tinggi, sehingga dapat menyumbang limbah yang mengandung logam berat Pb, Zn dan Cr. Limbah logam berat yang terakumulasi dalam perairan, akan  mengendap dalam sedimen dan seiring berjalannya waktu akan mengalami peningkatan. Tujuan dari penelitian ini, untuk mengetahui konsentrasi Pb, Zn, dan Cr berdasarkan kedalaman vertikal, hubungannya dengan karbon organik total (KOT) dan ukuran butir sedimen di Pantai Marunda. Sampel sedimen diambil menggunakan polietylen sediment core dan dipisahkan berdasarkan kedalamannya (1-3 cm, 4-6 cm, dan 7-9 cm). Logam berat dalam sedimen dianalisis menggunakan metode destruksi asam dan diukur nilai absorbansinya menggunakan AAS, karbon organik total menggunakan metode loss of ignition (LOI) dan analisa tekstur sedimen dengan metode pengayakan dilanjutkan pemipetan. Hasil menunjukkan bahwa konsentrasi rerata logam berat Pb, Zn, Cr secara berurutan pada lapisan atas sebesar 5,14; 107,19; dan 12,79 ppm, lapisan tengah sebesar 4,41; 100,20; 12,28  ppm serta lapisan bawah sebesar 4,8; 101,30; 14,10 ppm. Logam berat Zn dan Cr berkorelasi positif kuat terhadap KOT dan persentase lumpur, sedangkan terhadap Pb berkorelasi negatif. Hasil penelitian ini menggambarkan bahwa distribusi logam berat Pb, Zn dan Cr secara vertikal menunjukkan konsentrasi tinggi pada lapisan permukaan yaitu pada kedalaman sedimen 1-3 cm dan keberadaanya ditentukan oleh konsesntrasi  KOT dan fraksi sedimen jenis lumpur. The Marunda Beach is located on the Jakarta Bay and adjacent to the mouth of the Tiram River. Anthropogenic activity around Marunda Beach is very high, so it can contribute the heavy metals such as Pb, Zn and Cr. The heavy metal will accumulate in the sediment and over time will be increase. The purpose of this study was to determine the vertical distribution of Pb, Zn, Cr, and their relationship to total organic carbon (TOC) and the grain size. Sediment samples were taken using polyethylene cores and this sample separated based on their depth (1-3 cm, 4-6 cm, and 7-9 cm). The heavy metals were analyzed using acid destruction and absorbance values were measured using AAS, TOC using the loss of ignition (LOI) and sediment texture with a sifting method, followed by pipetting. The results showed that the average concentration of Pb, Zn, Cr in the upper layer was 5.14; 107.19; 12.79 ppm, in the middle layer of 4.41; 100.20; 12.28 ppm and in the lower layer 4.8; 101.30; 14.10 ppm, respectively. Zn and Cr are strongly positively correlated to TOC and mud, and vice versa, the relationship to Pb is negative. The results of this study found that the vertical distribution of Pb, Zn and Cr was high in the surface layer (1-3 cm) and their presence was determined by TOC concentration and mud fraction.

scholarly journals Characteristics of opening in the ice cover formed by the gas vents

2018 ◽  
Vol 58 (3) ◽  
pp. 405-416
Author(s):  
G. S. Bordonskiy ◽  
S. D. Krylov ◽  
A. A. Gurulev ◽  
A. O. Orlov ◽  
S. V. Tsyrenzhapov
Keyword(s):  
Baikal Region ◽  
Water System ◽  
Lower Surface ◽  
Eutrophic Lake ◽  
Ice Cover ◽  
Narrow Channel ◽  
Ice Thickness ◽  
Winter Period ◽  
Small Water ◽  
Ice Water

«Proparina» (russ) is a small hole in the ice cover formed by steaming of the ice by the gas vents. Some characteristics of this phenomenon were studied by the example of formation of one proparina found in March 2015 in the ice cover of the shallow eutrophic Lake Shakshinskoye (Trans-Baikal Region). The interest in this object is due to the fact that a proparina, unlike a polynya (small water opening in ice), is formed after the establishment of the ice cover and it can appear in those parts of a reservoir where there is no clearly expressed inflow or outflow of water. Although proparinas do often occur on some water bodies, e.g. Lake Baikal, a detailed description of their structure and process of formation is not available. Research on features of the proparina in the ice of the Lake Shakshinskoye and adjacent areas of this reservoir was carried out on March 25 and 28 in 2015. Melting at the lower and upper ice cover boundaries started at that time, and it was found that the proparina under investigation was formed in the center of a dome-shaped area where the ice thickness decreased compared to the adjoining parts within a distance of 200 meters. Gradient of the lower surface in the dome was on average 5 centimeters per 100 meters at a distance from the center. We found a narrow channel in the ice through which gas came into the proparina in the form of separate portions. The maximum recorded volume of gas that came into the open proparina reached 10 l/min. The channel is supposed to be formed at the end of winter period due to the release of gas during the melting of the lower layers of the ice cover and the subsequent movement of gas bubbles into the center of the dome. To study the ice cover structure, we measured thermo-microwave self-radiation of the “ice-water” system in the centimeter range. Such measurements allow detecting changes in ice thickness with an accuracy of 1 cm. It is assumed that the accumulation of gases under the ice causes the instability of the water column due to warming by the heat fl w from the bottom layers and initiates the circulation and, thus, formation of proparina.

A Study of Ice-Formation Phenomena on Freezing of Flowing Water in a Pipe

1987 ◽  
Vol 109 (4) ◽  
pp. 965-970 ◽  
Author(s):  
T. Hirata ◽  
H. Matsuzawa
Keyword(s):  
Freezing Temperature ◽  
Ice Formation ◽  
Freezing Process ◽  
Ice Thickness ◽  
Flow Transition ◽  
Water Pipe ◽  
Temperature Ratio ◽  
Smooth Change ◽  
Ice Water ◽  
Ice Shapes

Ice-formation phenomena in a water pipe whose wall is kept at a uniform temperature lower than the freezing temperature of water are examined under the conditions of an unstable ice-water interface. The onset conditions for a step or smooth change in ice thickness occurring with flow transition from laminar to turbulent are found to be correlated with ice thickness at the contraction region of the ice band and are expressed as a function of a pipe Reynolds number ReD, and a cooling temperature ratio θ. It is shown that the transient freezing process depends strongly on flow as well as temperature conditions and that the typical ice shapes at steady-state conditions can be classified on a θ-ReD coordinate system.

scholarly journals Migration Law of Atrazine During Freezing of Water

2021 ◽  
Author(s):  
Yan Zhang ◽  
Wanli Zhao ◽  
Aixin Yu ◽  
Yucan Liu ◽  
Fangyun Ren ◽  
...  
Keyword(s):  
Distribution Coefficient ◽  
High Latitude ◽  
Freezing Temperature ◽  
Freezing Process ◽  
Ice Thickness ◽  
Migration Ability ◽  
Initial Concentration ◽  
Atrazine Concentration ◽  
Freezing Period ◽  
Migration Law

Abstract To explore the migration law of atrazine during the freezing process, an indoor simulated freezing experiment was carried out. The distribution coefficient (K) was used to characterize the migration ability of atrazine and explore the effects of freezing thickness, freezing temperature, and initial concentration on the migration of atrazine between ice and water. The research results showed that the concentration relationship between the ice and water phases was: ice < water before freezing < water under the ice. This indicates that atrazine migrated to the water under the ice during the freezing process in our experiment. The K value decreased as the ice thickness, freezing temperature, and initial concentration increased; thus, the greater the ice thickness, the higher the freezing temperature, the greater the initial atrazine concentration, and the greater the ability of atrazine to migrate to the water under the ice. This study provides a reference for managing natural waterbodies in high-latitude and high-altitude environments during the freezing period.

Viability of Edwardsiella tarda and Esherichia coli preserved with glycerol-tryptone soy broth (TSB) kept at freezing temperature

2013 ◽  
Vol 1 (2) ◽  
pp. 154
Author(s):  
Abdur Rohman ◽  
Frans Ijong ◽  
I K Suwetja
Keyword(s):  
Research And Development ◽  
Germ Plasm ◽  
Freezing Temperature ◽  
Experimental Methods ◽  
Edwardsiella Tarda ◽  
Diagnostic Tools ◽  
Glycerol Concentration ◽  
E Coli ◽  
Esherichia Coli ◽  
Escherchia Coli

Preservation of bacteria carried out in relation to the collection and preservation of germ plasm microbe is useful for research and development or for the establishment of diagnostic tools. Glycerol is a good preservation media but it is not known what doses should be used for effective preservation.  This research used two experimental  methods consisting of 2 factors and 3 treatments. This study aimed to find the best glycerol concentration that can be used to preserve Edwarsiella tarda and Escherchia coli in the -20ºC environment, to understand the viability of bacteria after being preserved and to describe the characteristics of the preserved bacteria. Treatments applied were 10%, 15% and 20%  glycerol in TSB. Viability of the bacteria was analyzed after 7, 14, 28, 35, and 42 days of preservation. Results showed that E.coli bacteria preserved in 15%  glycerol had the highest viability, i.e. 84% and preserved in 10% glycerol had the lowest viability, i.e. 80%. But for E. tarda bacteria preserved in 10% glycerol had the highest viability, i.e. 1.83% and preseved in 15% glycerol had the lowest viability, i.e. 0,55%. Preservasi bakteri dilakukan dalam kaitannya dengan koleksi dan konservasi plasma nutfah mikroba yang berguna untuk penelitian dan pengembangan atau untuk pembentukan alat diagnosa. Gliserol merupakan bahan preservasi yang baik, tetapi belum diketahui dosis yang baik dan efektif untuk preservasi bakteri Edwarsiella tarda dan Escherchia coli pada suhu -20ºC. Penelitian ini dilakukan dengan metode eksperimen yang terdiri dari 2 faktor dan 3 taraf perlakuan, masing-masing perlakuan dengan 3 kali ulangan, media preservasi yang digunakan adalah TSB dan gliserol dengan konsentrasi 10%, 15% dan 20%. Parameter yang diukur adalah viabilitas dan kecocokan/penyimpangan karakteristik biokimia. Penelitian ini dilaksanakan di Laboratorium Balai Karantina Ikan Pengendalian Mutu dan Keamanan Hasil Perikanan Manado, dari bulan September sampai dengan November 2013. Tujuan Penelitian ini adalah untuk menentukan konsentrasi gliserol dalam TSB sebagai media preservasi yang efektif dan efisien pada bakteri  Edwarsiella tarda dan Escherchia coli yang dipreservasi dengan suhu -20ºC dan disimpan selama 42  hari. Hasil penelitian menunjukkan adanya penurunan laju pertumbuhan bakteri selama preservasi. Persentase viabilitas  bakteri E. coli yang tertinggi selama preservasi diperoleh dengan penggunaan gliserol konsentrasi 15% dengan jumlah 84% dan yang terendah adalah dengan penggunaan konsentrasi 10% yakni sebesar 80%, sedangkan untuk E. tarda persentase viabilitas  bakteri yang tertinggi selama preservasi diperoleh dengan penggunaan gliserol konsentrasi 10% dengan jumlah 1,83% dan yang terendah adalah dengan penggunaan konsentrasi 15% yakni sebesar 0,55%. Berdasarkan uji statistik analisis variasi (ANAVA) didapat hasil F hitung E. tarda dan E. coli yang lebih besar  dari FTabel dengan tingkat kepercayaan 95 %.

scholarly journals Subglacial hydrology and the formation of ice streams

2014 ◽  
Vol 470 (2161) ◽  
pp. 20130494 ◽  
Author(s):  
T. M Kyrke-Smith ◽  
R. F Katz ◽  
A. C Fowler
Keyword(s):  
Ice Sheet ◽  
Water System ◽  
Coupled Model ◽  
Water Film ◽  
Mass Conservation ◽  
Ice Streams ◽  
Base Level ◽  
Ice Sheet Dynamics ◽  
Ice Water ◽  
Subglacial Meltwater

Antarctic ice streams are associated with pressurized subglacial meltwater but the role this water plays in the dynamics of the streams is not known. To address this, we present a model of subglacial water flow below ice sheets, and particularly below ice streams. The base-level flow is fed by subglacial melting and is presumed to take the form of a rough-bedded film, in which the ice is supported by larger clasts, but there is a millimetric water film which submerges the smaller particles. A model for the film is given by two coupled partial differential equations, representing mass conservation of water and ice closure. We assume that there is no sediment transport and solve for water film depth and effective pressure. This is coupled to a vertically integrated, higher order model for ice-sheet dynamics. If there is a sufficiently small amount of meltwater produced (e.g. if ice flux is low), the distributed film and ice sheet are stable, whereas for larger amounts of melt the ice–water system can become unstable, and ice streams form spontaneously as a consequence. We show that this can be explained in terms of a multi-valued sliding law, which arises from a simplified, one-dimensional analysis of the coupled model.

RESULTS OF PETROGRAPHIC ANALYSIS OF MESHOKO CERAMICS

Kavkazologiya ◽  
2021 ◽  
pp. 12-25
Author(s):  
S.M. OSTASHINSKIJ ◽  
◽  
M.A. KULKOVA ◽  
Keyword(s):  
Lower Layer ◽  
Middle Layer ◽  
Middle Part ◽  
Petrographic Analysis ◽  
Group 4 ◽  
Group 3 ◽  
Biogenic Carbonates ◽  
Group 5 ◽  
Group 2 ◽  
Carbonate Composition

The article presents the results of petrographic analysis of the ceramics of the Chalcolithic settlement of Meshoko. A total of 42 fragments were examined (see appendix), 10 of which belong to the upper part of the monument's sediments (layers 1 and 2a; Fig. 1), 20 refer to the middle part of the sediments (layer 2b; Fig. 2), 12 – to the lower part (layer 3; Fig. 3). Based on the analysis, 5 groups of ceramics were identified (Fig. 4). Group 1 consists of fragments with an admixture of limestone, group 2 – with an admixture of diorite, group 3 – with an admixture of biogenic carbonates and sand, group 4 – with an admixture of calcite, group 5 – with an admixture of diorite and chamotte. Clays of smectite composition predominate in groups 1 and 2, while clays of smectite-carbonate composition predominate in groups 3 and 4. Comparison of these groups with stratigraphy revealed that most of the ceramics of groups 3 and 4 are confined to the lower layer, and groups 1 and 2 to the middle and upper layer (Table 1). In addition, the ceramics of these layers differ in the nature of the external surface treatment. Significant changes in the technology of making ceramics during the transition from the lower layer to the middle layer allow us to assume corresponding changes in the composition of the population.

scholarly journals Tabular Icebergs: Implication from Geophysical Studies of Ice Shelves

1980 ◽  
Vol 1 ◽  
pp. 55-55
Author(s):  
Sion Shabtaie ◽  
Charles R. Bentley
Keyword(s):  
Mass Balance ◽  
Sea Water ◽  
Ice Thickness ◽  
Ice Shelf ◽  
Frictional Drag ◽  
Ice Shelves ◽  
Ross Ice Shelf ◽  
Rift Zones ◽  
Different Characteristics ◽  
Ice Water

Recent geophysical and glaciological investigations of the Ross Ice Shelf have revealed many complexities in the ice shelf that can be important factors in iceberg structure. The presence of rift zones, surface and bottom crevasses, corrugations, ridges and troughs, and other features could substantially modify the hydraulics of iceberg towing and lead to disintegration of the berg in the course of transport.The relationships between the elevation above sea-level and total ice thickness for three ice shelves (Ross, Brunt, and McMurdo) are given; from them, expressions for the thickness/freeboard ratios of tabular icebergs calved from these ice shelves are obtained. The relationships obtained from the measured values of surface elevation and ice thickness are in agreement with models derived assuming hydrostatic equilibrium.Areas of brine infiltration into the Ross Ice Shelf have been mapped. Examples of radar profiles in these zones are shown. Absorption from the brine layers results in a poor or absent bottom echo. It is probable that little saline ice exists at the bottom of the Ross Ice Shelf front due to a rapid bottom melting near the ice front, and that the thickness of the saline ice at the bottom of icebergs calving from the Ross Ice Shelf is no more than a few meters, if there is any at all.We have observed many rift zones on the ice shelf by airborne radar techniques, and at one site the bottom and surface topographies of (buried) rift zones have been delineated. These rift zones play an obvious role in iceberg formation and may also affect the dynamics of iceberg transport. Bottom crevasses with different shapes, sizes, and spacings are abundant in ice shelves; probably some are filled with saline ice and others with unfrozen sea-water. Existence of these bottom crevasses could lead to a rapid disintegration of icebergs in the course of transport, as well as increasing the frictional drag at the ice-water boundary.Radar profiles of the ice-shelf barrier at four sites in flow bands of very different characteristics are shown. In some places rifting upstream from the barrier shows regular spacings, suggesting a periodic calving. Differential bottom melting near the barrier causes the icebergs to have an uneven surface and bottom (i.e. dome-shaped).Electrical resistivity soundings on the ice shelf can be applied to estimate the temperature-depth function, and from that the basal mass-balance rate. With some modifications, the technique may also be applied to estimating the basal mass-balance rates of tabular icebergs.

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