Iron Concretions Research Articles

Soil fertility based on mineralogical properties to support sustainable agriculture management

<p>Detailed information on soil mineral composition has been crucial in providing the basis for designing sustainable agricultural practices, as this information offers long-term insights into natural soil fertility. This research aimed to further investigate the characteristics of soil mineral composition as a basis for managing soil fertility. Three soil profiles representing three different parent materials have been examined in the field, and soil samples have been collected for laboratory analysis. Profile 1 originates from the Raung Volcano Rock Formation (Qhvr). Profile 2 originates from the Sukamade Formation (Toms). Profile 3 originates from Puger Formation (Tmp). The presence of Mount Raung volcanic influence results in distinct soil characteristics in Profiles 2 and 3 compared to typical sedimentary and karst rock soils. The sand fraction minerals in all three profiles are predominantly composed of opaque minerals, followed by rock fragments, ferromagnesian mineral series (olivine, augite, hypersthene, and hornblende), plagioclase minerals (anorthite, biotite, and labradorite), iron concretions, epidote, and tourmaline. The clay fraction minerals in all three profiles consist of illite, kaolinite, and quartz. The minerals illite and ferromagnesian groups in all three profiles play a significant role in increasing the availability of potassium, calcium, and magnesium nutrients, thereby reducing the need for fertilizers for these elements. The soils in all three profiles naturally possess good fertility; however, designing a sustainable agricultural system requires consideration of the morphology, landform, and climate of all three profiles.</p>

IoT for Cathodic Protection System as Iron Concrete’s Corrosion Protection

Iron concrete or reinforcement steel is steel used for reinforcement of concrete construction or known as reinforced concrete. Iron concrete can undergo a corrosion process caused by chemical or electrochemical reactions between reinforcement steel and its environment. One way to protect concrete from corrosion is cathodic protection. There are two types of cathodic protection, namely sacrificial anodes and impressed current cathodic protection (ICCP). ICCP is more commonly used for protection in reinforced concrete structures. In ICCP, negative current flows to the iron concrete and positive current flows to the anode. This is to protect the concrete from corrosion. In addition to the corrosion protection system, there is also a half-cell potential test to measure the chance of corrosion of the concrete. The project used IoT to monitor and control the ICCP. Measurements are made by reading the potential difference between the reference electrode and the iron concrete. The probability of corrosion can be determined by reading the corrosion probability table with ASTM C879-09 standard. The ICCP system in general still uses the manual method so that there are time efficiency problems in controlling the voltage and current for ICCP purposes, cannot schedule the provision of electric current and monitor it at any time, especially if the electric current flowing in the concrete is higher than the standard it should be. Based on the results of the tests carried out, the IoT system can regulate the power supply by setting the voltage and current and can schedule the power supply to provide electric current to the iron concrete and can provide notifications if the electric current flowing in the concrete is more than or less than ICCP standard.

Effects of Mineral Nutrition on Iron Toxicity Severity, Leaf Chlorophyll Levels and Grains Solubles Sugar of Floody Lowland Ratoon Rice (Oryza sp) Nerica L 14 under Rainfed Regime

Field fertilization trials were conducted on 15 cm high rice stubble in lowland rainfed rice to determine mineral nutrition (N-, P-, K-, Ca-, Mg-, and Zn-) effects on iron toxicity, agromorphological parameters, average contents of leaf chlorophyll and grains soluble sugar contents of Nerica L 14. Four complete block design of seven randomized treatments was used. Results indicate that iron toxicity occurred in unfertilized ratoon crops grown on undeveloped gleysol containing some iron concretions in upper layer. Characteristic symptoms covered about 6-25% of the field. Nitrogen fertilization totally corrected these symptoms, significantly increased (p = 0.00) chlorophyll a (0.21 mg.g-1 FL), b (0.30 mg.g-1 FL) and total (0.51 mg.g-1 FL) average contents of the three primaries functional leaves, height (60.11 cm) and tillering (8.56 tillers/plant) average of ratoon rice. In addition, Zn applied to soil induced an increase in grains soluble sugar content (3.23 mg glucose/g DM). Conclusion: iron toxicity, mainly caused by antagonism between Fe2+ and K+ as well as Fe2+ and Mg2+, also remains a constraint to rice ratoon cultivation. Its effects on agromorphological and agrophysiological parameters can be corrected by mineral fertilization and nitrogen applies particularly.

The design and construction of a collimator holder to equip beam tube D of the Tehran research reactor

The continued safe and efficient operation of a research reactor depends on the behavior of the structural materials making up its main components. Many of these materials are difficult to replace in view of hard-to-reach locations after installation or even storage after years of use due to radiation from high exposure to neutrons inside the research reactor structure. The neutron collimator is a major part of the beam-related devices used in a research reactor. This device is installed in the beam tube via a holder. The collimator holder used as a structural component of beam tube D in the Tehran Research Reactor (TRR) has been made of cast iron. This component has been installed inside the beam tube and subjected to irradiation for 30 years. As a result, it has become severely damaged and must be transferred to radioactive waste storage. A necessary measure to recommission beam tube D in TRR is selecting a replacement with higher quality. Suitable candidates for this purpose would be materials that retain the neutron beam quality in addition to being adequate for long lifetime management. In this case, lower induced activity, shorter half-life of produced radioisotopes, and shorter cooling time are desirable. The present work used ORIGEN2 and MCNPX2.6 computational codes to compare various materials, such as barite concrete (type BA), Portland iron concrete, and stainless steel (316), in terms of the induced activity for various reactor operation periods, radiation level for various cooling periods, and neutron and photon beam parameters at the beam tube nozzles. The results indicated that replacing cast iron with Barite concrete (type BA) retains the quality of the neutron beam. In addition, 11.2, 2.81, and 3.63 times more activity was induced in stainless steel, Portland iron concrete, and cast iron, respectively, compared to type-BA barite concrete after 30 years under identical conditions. Since barite concrete is economical and simpler to manufacture, it was a suitable replacement for cast iron as the material for the collimator holder in beam tube D in TRR. In addition, Barite concrete holder was constructed based on the calculations made in this research. The results showed a good agreement between dosimetry experimental data and calculation results with a 3 % error.

The design and optimization of a radiation shield for the Tehran Research Reactor's neutron diffraction facility

In this paper, a novel optimal radiation shield for the Tehran research reactor's neutron powder diffraction facility was designed to reduce undesirable neutron and gamma dose rates. A layer-by-layer methodology was considered based on the design approach to achieve a dose rate of less than 30 μSv/hr. MCNPX was used for this purpose as a Monte Carlo radiation transport code. A combination of neutron and gamma absorbers and moderators was employed to create this shield. The results indicated that the shield's six distinct layers met the design objective, totaling 65 cm in thickness. This newly designed shield comprises 15 cm paraffin, 15 cm Portland iron concrete, another 15 cm paraffin, 5 cm solid boric acid, another 10 cm Portland iron concrete, and 10 cm lead. The neutron and photon dose rates are 9.35 and 12.81 μSv/hr, respectively, which is one-sixteenth and one-third of the current facility shield. Validation of the simulation was accomplished by comparing the results for the current shield to experimental data.

Control of produced water with highly corrosive medium in oil-gas production

The construction of middle oil-gathering facility, in which technological processes are managed in a closed medium is necessary for environmental protection to control highly corrosive medium in oil and gas production. Associated gas separated from the fluid in initial separation unit within middle oil-gathering facility enters gas-gathering point with low pressure, and the liquid - into the pig of oil, water and sand, which should be constructed from iron concrete for cleaning from mechanical impurities sediments and salt as well. The liquid charge from the separation unit and pig of oil, water and sand is based upon the law of communicating vessels. To supply long-life for reservoirs, the inner and outer walls should be covered with a special coating and additionally, electrochemical protection should be provided as well.

Hematite concretions from the Late Jurassic Jhuran sandstone, Kutch, western India: Implications for sedimentary diagenesis and origin of “blueberries” on Mars

The discovery of iron-bearing concretions is one of the most exciting discoveries in the recent past on Mars. We report here an analog terrestrial site hosting hematite-bearing concretions belonging to Jhuran sandstone, Kutch, India. Based on petrography, mineralogy, geochemistry and spectral studies (Visible Near Infrared: VNIR and Mössbauer), we show very good similarity between the Jhuran concretions and the “Martian blueberries”. The Jhuran and Martian concretions share similar textural attributes and are of comparable size, but are geochemically different. Based on VNIR study, the mineralogy of the concretions is constrained to comprise hematite, goethite and kaolinite; however, Mössbauer spectra could not detect the pure hematite phase, and instead, suggest the presence of a poorly crystalline mixture of goetheite and hematite. Thus, the Jhuran concretions are most commonly mixtures of goethite and hematite, and not pure hematite. The enrichment of Ni within concretions as compared to the host sandstones is also comparable with the reported Ni-enrichment of Martian concretions. We propose sedimentary diagenesis as the most feasible process that can explain incorporation of Ni into the concretions by coupled substitution in the iron oxide structure. This is inconsistent with the cosmic spherule hypothesis to explain Martian concretion formation, and instead, sedimentary diagenetic processes appear more likely.Finally, the morphology, texture, geochemistry and spectroscopic investigations suggest that the Jhuran iron concretions most likely formed due to sedimentary diagenetic processes, similar to inferences from other Martian analogue localities. Therefore, this study has relevance for understanding the formation processes of Martian blueberries and diagenetic processes on Mars. The Kutch area also has geological similarity with other aspects of ancient Mars and could be a potential testing site for carrying out future Mars exploration studies on Earth.

Behavior of uranium series in groundwater of the Wajid Formation, Wadi AdDawasir, Saudi Arabia.

The inventories and the possible mechanisms behind the relative deficiency of both radium and uranium release processes within an elevated gamma-anomalous rock were investigated. A field survey was performed on the highest radioactive anomalous zone that was recorded at Jabal Al Alam (20° 13' 10.06″ N and 44° 14' 32.13″), with the ferruginous sandstone, iron oxide band, and iron concretions (with uranium content and reaching up to1500 ppm). The chemical analyses and the laboratory's gamma-ray spectrometric measurements demonstrated high uranium levels in the analyzed rock samples of the Wajid Sandstone (up to 1000 ppm). The borehole geophysical logs further confirmed that the radioactive anomalies are attributed to the sandstone sequence of the Wajid Formation that is often found associated with elevated concentrations of uranium. The groundwater samples taken from the wells tapping the Wajid aquifer showed uranium concentrations ranging from 0.01 to 5.5 ppb (μg/L). The average 226Ra in groundwater samples was 0.2 Bq L-1. The majority of the 226Ra and 228Ra activities were below the lower limit of detection (LLD). The radiochemical analyses of water samples from the Wajid aquifer display low concentrations of both uranium and 226Ra, with relation to uranium content in host rocks. This was attributed to the fact that uranium is susceptible to form iron oxide complexes, causing them to precipitate in a more stable form. Furthermore, iron oxides coat the sand grains of the Wajid Formation and accordingly might act as a foundation for re-adsorption for both uranium and radium, resulting in their relative deficiency in the surrounding water. The coating might also act as a physical barrier resulting in hindrance of the recoil nuclei due to its significant thickness (several orders of magnitude) compared with that of the average (120 nm) whole alpha-recoil track (ART). The coating layer thickness was determined via scanning electron microscopy (SEM) and was found to be up to 180 μm.

Burnt clay or terra bruciata in coastal basins of Southern Lazio, Italy: Evidence for prehistoric ignicoltura or resulting from drainage of Holocene pyritic sediments?

In the Agro Pontino and Fondi basin (Southern Lazio, Italy), burnt clay type material is common and was generally ascribed to the impact of ignicoltura. Based on the widespread occurrence of this material it was hypothesized that in these areas such ignicoltura was widely practiced in pre- and protohistoric times. However, direct evidence thereof, in the form of distinctly fired material, is extremely scarce. Earlier published and recent observations and analyses of a number of characteristic burnt clay sites together provide strong evidence for a pedogenetic origin of this material, i.e. by weathering of Holocene pyritic humic to peaty clays, brought about by their drainage. The process is well known from studies on acid sulphate soils and results in the accumulation of secondary iron concretions that resemble burnt clay but have a pedogenetic origin. Other products formed include jarosite and eventually gypsum, both regularly found in connection with burnt clay type material in these Holocene coastal basins. It is concluded that current hypotheses concerning the role and intensity of ignicoltura in both areas need to be seriously revised. Lastly, it seems likely that such pedogenetic burnt clay also occurs in other Mediterranean coastal basins where during the Holocene pyritic sediments formed and later on were drained for agriculture.

ANALISIS LAJU KOROSI BESI BETON DENGAN MEDIUM TANAH RAWA

The research on corrosion rate analysis of concrete iron with swampsoil medium has been conducted. The aims of this study were to determine thecorrosion rate and the types of corrosion that occurred in concrete iron withswamp soil medium. The methods of this study are Weight Loss method, AtomicAbsorption Spectroscopy (AAS) test, and Scanning Electron Microscope-EnergyDispersion X-Ray (SEM-EDX). This study used a different immersion timevariant, such as 20 days, 40 days, 65 days, and without medium for 65 days. Theconcrete iron used in this study is concrete U-24 or plain concrete iron 10. Thecorrosion rate that occurs in iron concrete with swamp soil medium at 20 daysimmersion is 20977.5868 mmpy, 40 days immersion is 17721.9174 mmpy, 65days immersion is 16932. 9071 and 65 days without a medium are 3023.3793mmpy. The more time, the rate of corrosion become more slowly due to theinfluence of corrosion products that have occurred. The corrosion rate without themedium is slower than the corrosion rate with the medium. The types of corrosionthat occurs in concrete iron with swamp soil medium are crevice corrosion andpitting corrosion.

Armoured sponge spicules from Panarea Island (Italy): Implications for their fossil preservation

A variety of calcareous and siliceous skeletal components are associated with exceptional, still active deposits of modern iron ooids off Panarea, one of the volcanic islands of the Aeolian Arc (Tyrrhenian Sea, Italy). Both ooids and skeletal components occur as loose sediments influenced by submarine hydrothermal fluid vents. Whereas iron ooids are exclusively made of goethite laminae primarily nucleated on volcaniclastic material, sponge spicules – that represent most of the siliceous skeletal component – develop laminated coatings (concretions) of varying sizes. This partial or total coating consists of regularly banded Fe‒rich layers exhibiting the same textural features and mineralogical composition (goethite) of the ooid cortex developed around inorganic cores. Spicules did not reveal any obvious attaching structure or interfingering with the surrounding coating and did not undergo bioerosion or any other evidence of biological intervention during their development. A hydrothermal origin, compatible with the general setting, is therefore proposed for these armoured sponge spicules. We believe that this unique modern case of iron concretions produced on siliceous spicules can contribute to explain other known fossil cases as well as to understand the taphonomy of this type of biogenic silica that seems rarely to have been preserved in such an extreme habitat.

Geochemistry of subsurface Late Quaternary ironstones in Rajshahi and Bogra Districts, Bangladesh: implications for genetic and depositional conditions

The present study deals with the geochemistry of Late Quaternary ironstones in the subsurface in Rajshahi and Bogra districts, Bangladesh with the lithological study of the boreholes sediments. Major lithofacies of the studied boreholes are clay, silty clay, sandy clay, fine to coarse grained sand, gravels and sands with (fragmentary) ironstones. The ironstones contain major oxides, Fe2O3* (* total Fe) (avg. 66.6 wt%), SiO2 (avg. 15.3 wt%), Al2O3 (avg. 4.0 wt%), MnO (avg. 7.7 wt%), and CaO (avg. 3.4 wt%). These geochemical data imply that the higher percentage of Fe2O3* along with Al2O3 and MnO indicate the ironstone as goethite and siderite, which is also validated by XRD data. A comparatively higher percentage of SiO2 indicates the presence of relative amounts of clastic quartz and manganese-rich silicate or clay in these rocks. These ironstones also have significant amounts of MnO (avg. 7.7 wt%) suggesting their depositional environments under oxygenated condition. Chemical data of these ironstones suggest that the source rock suffered deep chemical weathering and iron was mostly carried in association with the clay fraction and organic matter. Iron concretion was mostly formed by bacterial build up in swamps and marshes, and was subsequently embedded in clayey mud. Within the coastal environments, the water table fluctuates and goethite and siderite with mud and quartz became dry and compacted to form ironstone.

The application of quartz grain morphology measurements to studying iron-rich duricrusts

Iron-rich duricrust profiles are commonly located on old flat surfaces. They promote landscape stability by the protective action of ferricrete, providing important records of multiple soil and geomorphic processes, as well as paleoclimatic events. In the Southern Serra do Espinhaço (SSE) in Brazil, iron-rich duricrust profiles occur on flat to slightly convex hills of quartzite at elevations of mostly 1200–1400 m a.s.l. Some of these profiles may be remnants of old paleosurfaces. Here we describe an image analysis technique to measure morphological attributes of quartz grains in thin sections of iron-rich duricrusts; we present a way to investigate the genesis of these materials. Size and shape variations of quartz grains were measured for iron-rich duricrust profiles from four different locations (GS2, PF1, PF2 and PF3). Thin sections of 5 × 7.5 cm from surface horizons and iron-rich duricrusts were studied. Distinct morphological regions (iron concretion and matrix) of iron-rich duricrusts were separately analyzed to identify variations in regolith morphology. A TESCAN VEGA3 scanning electron microscope (SEM) was used to produce backscattered electron (BSE) images for regions of sufficient area to enable the use of image analysis software (ImageJ 1.50i). BSE images provide a clear contrast between quartz grains and iron-rich duricrust matrix allowing resolution of quartz grains for specific investigation. The size, circularity and roundness of many quartz grains were easily determined. This procedure enables the quantitative analysis of soil materials allowing comparisons of soils and the testing of hypotheses for soil genesis. Quartz grains within iron concretions of PF3 had different morphological properties from quartz in the surrounding ferricrete indicating that different processes had occurred during the genesis of the two materials. In contrast, PF1 which showed no evidence of parent material diversity, contained quartz grains that are indicative of a polycyclic character. We observed fragments of iron concretions with pores previously occupied by quartz grains indicating that extensive quartz dissolution had occurred during duricrust evolution.

The method to soften the concretions of ceramics in the \u201cNanhai I\u201d Shipwreck of China Southern Song Dynasty (1127\u20131279AD)

The “Nanhai I” shipwreck of the Southern Song dynasty is the existent oldest and the most integrally preserved shipwreck in the world. Inside the shipwreck most of the ancient ceramics were covered with different types of concretions. In our work, different types of concretions were analyzed using stereomicroscopy, X-ray fluorescence (XRF) and X-ray diffraction (XRD). Based on those analyses, we applied a new physical method of heating and boiling to soften the concretions and remove them from the ceramics. It turned out that this method was efficient to remove the white shellfish concretions, gray concretions and red iron concretions, which not only provided a good basis for the preservation of ancient ceramics of the shipwreck, but also benefited the archaeological research on ancient ceramics.

Excavations of ironware of the third–fifth century from Marvele necropolis (Lithuania)

This study presents the overview of ironware excavations of the third–fifth century demolished tombs from Marvele necropolis. Three axes, four spearheads, two knives and a clasp were excavated in 2006. Afterwards, a metallographic and chemical analysis as well as mechanical properties of artefacts, also metallurgical slag, clinkers and iron concretions found in the surroundings of tombs were tested and presented in this article. General tests were executed in order to compare results with other archaeological and scientific researches. Metallographic analysis and hardness tests’ results revealed that axes were forged from two separate billets of iron, whilst spearheads and knives from one. The results of chemical analysis have affirmed earlier results of other Lithuanian archaeological sites. Although some differences in chemical composition were observed, this fact shows possible not local origin of some ironware.

New methodology for soil aggregate fractionation to investigate phosphorus transformations in iron oxide‐rich tropical agricultural soil

SummaryUnderstanding phosphorus (P) dynamics at the soil aggregate level is necessary to increase P‐use efficiency and for reducing reliance on external P inputs. Traditional methods of soil fractionation are often unsuitable for the study of P dynamics within soil aggregates of tropical soil because of the large amounts of strongly P‐sorbing iron oxide concretions. Here, we present an alternative method of soil fractionation to assess carbon (C), nitrogen (N) and P cycling in a very weathered tropical soil (total P, 883 ± 19 mg P kg−1) rich in iron concretions (total P, 1136 ± 28 mg P kg−1). This wet‐sieving method removes large iron concretions (> 2000 µm) without any marked effect on smaller soil aggregates, which reduces the error associated with overestimation of aggregation. It reduces variation in nutrient content within larger soil aggregates, and also enables nutrient cycling within water‐stable soil aggregates to be studied. In addition, because it uses field‐moist soil it is possible to measure microbial biomass, community structure, or both, within aggregate fractions. Although this method is important for measuring and understanding C, N and P dynamics within soil aggregate fractions, both the nutrient content and biochemical characteristics of the iron concretions need to be considered to obtain a deeper understanding of nutrient dynamics within the whole soil.HighlightsAn aggregate fractionation method for tropical soil rich in iron concretions. This method can separate large iron concretions from soil aggregates. Error and variation in aggregation measurements and associated nutrient concentrations are reduced. Measurement of P in concretions and aggregates separately provides a better understanding of P dynamics.

Bleached mudstone, iron concretions, and calcite veins: a natural analogue for the effects of reducing CO2‐bearing fluids on migration and mineralization of iron, sealing properties, and composition of mudstone cap rocks

AbstractThis study investigates the Wangfu Depression of the Songliao Basin, China, as a natural analogue site for Fe migration (bleaching) and mineralization (formation of iron concretions) caused by reducing CO2‐bearing fluids that leak along fractures after carbon capture, utilization, and storage. We also examined the origin of fracture‐filling calcite veins, the properties of self‐sealing fluids, the influence of fluids on the compositions of mudstone and established a bleaching model for the study area. Our results show that iron concretions are the oxidative products of precursor minerals (pyrite and siderite) during uplift and are linked to H2S and CO2 present in early stage fluids. The precipitation of calcite veins is the result of CO2 degassing and is related to CO2, CH4, and minor heavy hydrocarbons in the main bleaching fluids. In our model, fluids preferentially enter high‐permeability fracture systems and result in the bleaching of surrounding rocks and precipitation of calcite veins. The infilling of calcite veins significantly decreases the permeability of fractures and forces the fluids to slowly enter and bleach the mudstone rocks. The Fe2+ released during bleaching migrates to elsewhere with the solutions or is reprecipitated in the calcite veins and iron concretions. The formation of calcite veins reduces the fracture space and effectively prevents fluid flow. The fluids have an insignificant effect on minerals within the mudstone. In terms of the chemistry of the mudstone, only the contents of Fe2O3, U, and Mo change significantly, with the content of U increasing in the mudstone and the contents of Fe2O3 and Mo decreasing during bleaching.

Iron concretions within a highly altered unit of the Berlins Porphyry, New Zealand: an abiotic or biotic story?

The Berlins Porphyry located on the South Island of New Zealand provides an opportunity to examine iron concretions formed in a subterranean system. Specifically, an alteration zone within the Berlins Porphyry contains iron concretions similar to sedimentary biologically-mediated iron concretions. Here, we provide evidence for two sources of dissolved Fe (II) that potentially aided in the formation of the iron concretions. Furthermore, we discuss the potential for microbial involvement in the anaerobic oxidation of Fe (II) to Fe (III) to form magnetite. Evidence in support of this hypothesis includes the low concentrations of iron and sulfur in the white hydrothermally altered porphyry outcrop and concretion cores; concentrated pyrite and magnetite mineralisation surrounding the cores; and δ13C values indicative of organic carbon (averaging −26 ‰ ± 4 ‰) within the iron cement, porphyry-core-boundary and outer weathered rinds of the concretions. Overall, these unusually preserved iron concretions could represent a new environmental niche for microorganisms and a potential analogue for microbially induced iron-oxidation. More importantly, this study illustrates the many obstacles involved in analysing and interpreting potential subterranean biosignatures.

The blueberry (iron nodule) from the Shark Bay area, Western Australia and its implication to the genetic environments of iron nodules on Mars

Fist-sized iron nodules, extensively found on the ground of Western Australia, were investigated by element analysis (XRF, ICP-MS and ICP-AES), electron microscopes, X-ray diffraction and Mossbauser spectroscopy. Loosely-packed pisoidic structures of a few to >10 mm in size were observed in the cross-section of nodules. Chemically, the nodules are majorly made of O, Si, Fe and Al, and share similar REE pattern with the loess sourced Greatford concretions from New Zealand. Angular quartz particles, nano-sized goethite and hematite are found to be the major mineral phases. Other minerals, such as detrital zircon, barite and Ce-containing particles can also be observed but of very low abundance. No detectable carbonate or amorphous silica implies that these nodules have experienced little underground fluid alteration. The quartz particles showing particularly three sections of fractal size-distributions, together with their extensive broken features and conchoidal fractures, strongly suggest in situ fragmentation of the host rock with minimum later dynamic sorting. These observations indicate the genetic environment of those nodules is always close to the surface of the tectonically stable ground since their formation. Because of the similarity of climatic and geological features, the genesis and preservation environment of these nodules in Western Australia may provide clues on the formation of Martian iron concretions

Calculating the Out-core Radioactivity in VVR-S Reactor after Shutdown

The results of coupled nuclear codes, WIMS-CITATION-ANISN-ORIGEN/MCNP-ORIGEN, and gamma spectrometry measurements of representative samples are compared. Based on this methodology, the radiation level of the reactor block materials at 4050 days after shutdown could be estimated. The aluminum and graphite are the most activated waste material. Iron cast and concrete are radioactive wastes, too.