The Red Sea Metalliferous Sediments

Mapping Intimacies ◽

10.5194/egusphere-egu21-12263 ◽

2021 ◽

Author(s):

M. Clara Modenesi ◽

J. Carlos Santamarina

Keyword(s):

Red Sea ◽

Environmental Conditions ◽

Raw Materials ◽

Soil Classification ◽

Complete Characterization ◽

Liquid Limit ◽

Engineering Properties ◽

Soil Behavior ◽

Sediment Formation ◽

Brine Pools

The demand for metals and raw materials continues to increase as onshore deposits become more depleted. Our oceans contain large unexplored areas that may contain new resources in the form of Mn-nodules, Co-rich crusts, and massive sulfides. A complete characterization and assessment of these deposits are fundamental for the evaluation of resource extraction, separation, and disposal processes.The Red Sea holds unique examples of sediment accumulations formed under distinctive environmental conditions. The Atlantis II deep is located in the central part of the Red Sea at 2 km depth and on top of the spreading axis. This deep accumulates sediments that result predominantly from the discharge of hydrothermal fluids into hot and stratified brine pools. The changes in environmental conditions and the hydro-chemical conditions in the brine pool control sediment formation. The accumulations are enriched with metals, such as Ag, Au, Cu, Co, and Zn. The sediments in this deep hold a record of the formation history and their brine pools tell a story about on-going processes.On-going research at the Energy Geo-Engineering Laboratory EGEL, KAUST includes (1) Geotechnical index properties (liquid limit, grain size distribution, and specific surface) and consolidation tests to infer engineering properties, (2) Sediment classification based on the Revised Soil Classification System, (3) Geochemistry and mineralogy using XRD, ICP-OES and (4) Microstructure and texture with SEM imaging. An advanced sediment characterization of these fine-grained metalliferous deposits gives a comprehensive understanding of the soil behavior.

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Variability in chemical composition and antimicrobial activity of essential oil of Rosa × damascena Herrm. from mountainous regions of Iran

Chemical and Biological Technologies in Agriculture ◽

10.1186/s40538-021-00219-6 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Mansureh Ghavam ◽

Afsaneh Afzali ◽

Maria Manconi ◽

Gianluigi Bacchetta ◽

Maria Letizia Manca

Keyword(s):

Antimicrobial Activity ◽

Chemical Composition ◽

Essential Oil ◽

Essential Oils ◽

Environmental Conditions ◽

Raw Materials ◽

Rosa Damascena ◽

Mountainous Regions ◽

Aspergillus Brasiliensis ◽

Suitable Area

Abstract Background Essential oil of Rosa × damascena Herrm. is one of the most valuable and important raw materials for the flavor and fragrance industry. The cultivation of this plant has ancient origins, and Kashan was one of the first mountainous regions of Iran dealing with the cultivation of R. × damascena. In this study, both chemical composition and antimicrobial activity of different rose essential oils obtained from five mountainous areas of Kashan region (Maragh, Qamsar, Sadeh, Javinan, and Kamoo) has been investigated along with the influence of the environmental conditions on these properties. Results Results showed that yield and chemical composition of essential oils obtained from Rosa × damascena were significantly affected by the collection area. In particular, the yield of oils varied from ~0.08 to ~0.132% and citronellol (36.70-9.18%), geraniol (12.82-0.47%), nonadecane (22.73-10.36%), heneicosane (31.7-11.43%), and 1-nonadecene (6.03-3.93%) have been detected as main compounds in all the plants collected, but at different concentrations depending on the collection area. The best fragrance and the highest yield were found in the oil from Kamoo area. Similarly to the chemical composition, the antimicrobial activity of the essential oils was affected by their origin, and essential oil obtained from plants collected from Kamoo area disclosed the highest antibacterial and antifungal efficacy. Its inhibition halos were 17.33±0.58 mm against Aspergillus brasiliensis, 15.67±0.58 mm against Staphylococcus aureus, and 12.33±0. 58 mm against Streptococcus pyogenes. Essential oils of R. damascena were also effective against Gram-negative Pseudomonas aeruginosa and they had a MIC value of 62.50 μg/mL irrespective of the collection area (except the oil from Javinan area). On the contrary, the highest antifungal power against Candida albicans yeast was reached using the essential oil obtained from plants collected in Javinan region (MIC and MBC ~62.50 μg/mL). Conclusions Overall results underline the influence of environmental conditions of the different areas of Kashan region, on the chemical composition of and antimicrobial activity of the essential oils of Rosa × damascena. In addition, results disclosed that Kamoo seemed to be the most suitable area for the competitive cultivation of R. × damascena to the intensive production of aromatic flower oil and natural antimicrobial essential oils.

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Compressibility behaviour of remoulded, fine-grained soils and correlation with index properties

Canadian Geotechnical Journal ◽

10.1139/t99-128 ◽

2000 ◽

Vol 37 (3) ◽

pp. 712-722 ◽

Cited By ~ 93

Author(s):

A Sridharan ◽

H B Nagaraj

Keyword(s):

Liquid Limit ◽

Plasticity Index ◽

Engineering Properties ◽

Test Results ◽

Index Properties ◽

Initial Water ◽

Fine Grained ◽

Wide Range ◽

The Relationship ◽

Water Contents

Correlating engineering properties with index properties has assumed greater significance in the recent past in the field of geotechnical engineering. Although attempts have been made in the past to correlate compressibility with various index properties individually, all the properties affecting compressibility behaviour have not been considered together in any single study to examine which index property of the soil correlates best with compressibility behaviour, especially within a set of test results. In the present study, 10 soils covering a sufficiently wide range of liquid limit, plastic limit, and shrinkage limit were selected and conventional consolidation tests were carried out starting with their initial water contents almost equal to their respective liquid limits. The compressibility behaviour is vastly different for pairs of soils having nearly the same liquid limit, but different plasticity characteristics. The relationship between void ratio and consolidation pressure is more closely related to the shrinkage index (shrinkage index = liquid limit - shrinkage limit) than to the plasticity index. Wide variations are seen with the liquid limit. For the soils investigated, the compression index relates better with the shrinkage index than with the plasticity index or liquid limit.Key words: Atterberg limits, classification, clays, compressibility, laboratory tests.

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A Bayesian unsupervised learning approach for identifying soil stratification using cone penetration data

Canadian Geotechnical Journal ◽

10.1139/cgj-2017-0709 ◽

2019 ◽

Vol 56 (8) ◽

pp. 1184-1205 ◽

Cited By ~ 6

Author(s):

Hui Wang ◽

Xiangrong Wang ◽

J. Florian Wellmann ◽

Robert Y. Liang

Keyword(s):

Computational Cost ◽

Physical Space ◽

Soil Classification ◽

Feature Space ◽

Soil Behavior ◽

Cone Penetration ◽

Soil Layers ◽

Tip Resistance ◽

Input Dataset ◽

Spatial Configurations

This paper presents a novel perspective to understanding the spatial and statistical patterns of a cone penetration dataset and identifying soil stratification using these patterns. Both local consistency in physical space (i.e., along depth) and statistical similarity in feature space (i.e., logQt–logFrspace, where Qtis the normalized tip resistance and Fris the normalized friction ratio, or the Robertson chart) between data points are considered simultaneously. The proposed approach, in essence, consists of two parts: (i) a pattern detection approach using the Bayesian inferential framework and (ii) a pattern interpretation protocol using the Robertson chart. The first part is the mathematical core of the proposed approach, which infers both spatial pattern in physical space and statistical pattern in feature space from the input dataset; the second part converts the abstract patterns into intuitive spatial configurations of multiple soil layers having different soil behavior types. The advantages of the proposed approach include probabilistic soil classification and identification of soil stratification in an automatic and fully unsupervised manner. The proposed approach has been implemented in MATLAB R2015b and Python 3.6, and tested using various datasets including both synthetic and real-world cone penetration test soundings. The results show that the proposed approach can accurately and automatically detect soil layers with quantified uncertainty and reasonable computational cost.

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Appraisal of Geotechnical Characteristics of Ormara Soil, Baluchistan, Pakistan

International Journal of Economic and Environmental Geology ◽

10.46660/ojs.v10i3.304 ◽

2019 ◽

Vol 10 (3) ◽

pp. 22-26

Author(s):

Abdul Jabbar Khan ◽

Naveed Ahsan ◽

Muhammad Sanaullah ◽

Gulraiz Akhter

Keyword(s):

Triaxial Compression ◽

Liquid Limit ◽

Soil Samples ◽

Engineering Properties ◽

Clay Layer ◽

Compression Tests ◽

Geotechnical Characteristics ◽

Density Values ◽

Construction Plans ◽

Triaxial Compression Tests

Ormara is located 240 km west of Karachi which is a coastal and port city (25° 16' 29N, 64° 35' 10E) ofPakistan. Present study evaluates engineering properties of soils of Ormara for future construction plans and possibleexpansions in the area. Fifty bore holes were done in study area at depths of 20m, 40m and some (10 bore holes) were60m deep. The study area was divided into three major zones i.e. Foot hills, on-shore and off-shore. Groundwater wasencountered at depths of 2.75m on onshore and offshore zones and at 3.65m depth in foothill zone. Laboratory testingi.e. moisture content (12 to 38 %), liquid limit (from 26 to 34), plasticity index (10 to 18) of soil samples indicate thatsoils are low plastic to moderate plastic in nature. Soil samples of granular soils indicate angles of internal friction (ø)varying from 260- 36ºin upper sand layers while 260 to 30º in lower silt layers (encountered after the clay layer) andCohesion ranges 0 to 0.04kg/cm2 in all three zones. Further, unconsolidated undrained triaxial compression tests on aclayey soil sample indicated an undrained cohesion value of 28 kPa. Density values ranges from 1.6 to 2.05gm/cm3.Consolidation (Cv = 0.20 to 0.40 cm2/minute, Cc = 0.149 to 0.17) has been calculated for clay layer. Chemical testscarried out on soil samples indicated that soil and water both are reactive aggressively and may cause corrosion to steeland concrete disintegration.

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Evaluation of Suitability of Red Clay from Selected Areas of Gercus Formation, Sulaimaniyah, North Iraq, for the Construction of Embankment Dams

Iraqi Journal of Science ◽

10.24996/ijs.2021.62.9(si).13 ◽

2021 ◽

pp. 3417-3427

Author(s):

Amera I. Hussain Hussain ◽

Ibraheem I. Ibraheem

Keyword(s):

Ph Value ◽

Soil Classification ◽

Liquid Limit ◽

Dry Density ◽

Maximum Dry Density ◽

Red Clay ◽

Embankment Dams ◽

Filling Materials ◽

The North ◽

Geotechnical Assessment

In this research, a geotechnical assessment was conducted for clay of the Gercus Formation to determine its suitability for embankment dams. The selected area is located in the north of Iraq. Six samples were collected from two sites in Dokan (Sulaimaniyah) and Haibat Sultan mountain (Koysinjaq), three samples each. Various geotechnical (physical, mechanical and chemical) tests were conducted based on standard specifications. The results of the grain size test of clay samples showed their conformity with Zone C curves and their suitability for the construction of embankment dams, according to the Iraqi standard for roads and bridges. The results of the plasticity limits test showed that the soil is made of fine, low plasticity silt (ML), and low plasticity clay (CL), according to the unified standard soil classification. The water content and plasticity limit tests (liquid limit, plastic limit, and plasticity index) demonstrated that these clays are conformable with the limits of the Iraqi standards. The results of the modified compaction test found a maximum dry density value of 1.962 g/cm3 with an optimum moisture content of 11.5%. The results of the permeability index (K) revealed low permeability according to the Das classification and, therefore, showed the suitability of the samples as raw filling materials in the construction of dams. Chemical tests (sulfate content, organic materials content, total dissolved salts, gypsum content, and pH value) showed compatibility with the requirements for the use in dams construction under the Iraqi standard (SoRB/ R5).

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Application of Microbial Bioenzymes in Soil Stabilization

International Journal of Microbiology ◽

10.1155/2020/1725482 ◽

2020 ◽

Vol 2020 ◽

pp. 1-8

Author(s):

Eshetu Mekonnen ◽

Ameha Kebede ◽

Tekle Tafesse ◽

Mesfin Tafesse

Keyword(s):

Soil Stabilization ◽

Raw Materials ◽

Low Cost ◽

Field Tests ◽

Cost Effective ◽

Green Technology ◽

Engineering Properties ◽

Soil Stability ◽

Stabilizing Agents ◽

Dust Generation

Soil stabilization is a mechanical or chemical alteration of one or more soil properties to create an improved soil material possessing the desired engineering properties. The aim of this article was to review bioenzyme-based soil stabilization techniques with an emphasis on bioenzymes production, mechanism of soil stabilization and future challenges, and opportunities of the sector. Soils are stabilized to increase strength and durability or to prevent erosion and dust generation. Cost-effective soil stabilization technology has been a fundamental part of any construction and is very important for economic growth in any country. In some cases, construction has been challenged due to the high cost of soil stabilization processes. Besides, methods of stabilizations using common stabilizing agents are getting costly. Currently, there is a growing interest to identify new and green technology to improve construction techniques and to expand the road network. Therefore, the search for new materials and improved techniques to process the local materials has received an increased focus. For developing countries, bioenzymes are now creating an opportunity to improve soil stability with tremendous effectiveness in the overall process of soil stabilization. In the world, bioenzymes have been used in different projects for several years and are generally proprietary products, often of patented formulation that needs intensive field tests. Currently, the use and production of bioenzymes is becoming the most promising key for the advancement of a country by saving time, energy, and finance. It also reduces environmental pollution due to carbon emission by the conventional stabilizers. Thus, a better understanding of this emerging technology is of utmost importance to exploit any improvement it can offer to soil stability. With little research and practice, it is possible to produce soil stabilizing bioenzymes using local raw materials. Due to this, production of low cost, easily and widely applicable, and environmentally friendly enzymatic formulations from locally available raw materials should be the interest of research and academic institutes of any country.

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Clay-illuvial soils in the Polish and international soil classifications

Soil Science Annual ◽

10.1515/ssa-2015-0038 ◽

2015 ◽

Vol 66 (4) ◽

pp. 204-213 ◽

Cited By ~ 2

Author(s):

Cezary Kabała ◽

Elżbieta Musztyfaga

Keyword(s):

Environmental Conditions ◽

Soil Type ◽

Soil Classification ◽

The Other ◽

Soil Types ◽

Diagnostic Features ◽

Hierarchical Order ◽

History Of

AbstractSoil with a clay-illuvial subsurface horizon are the most widespread soil type in Poland and significantly differ in morphology and properties developed under variable environmental conditions. Despite the long history of investigations, the rules of classification and cartography of clay-illuvial soils have been permanently discussed and modified. The distinction of clay-illuvial soils into three soil types, introduced to the Polish soil classification in 2011, has been criticized as excessively extended, non-coherent with the other parts and rules of the classification, hard to introduce in soil cartography and poorly correlated with the international soil classifications. One type of clay-illuvial soils (“gleby płowe”) was justified and recommended to reintroduce in soil classification in Poland, as well as 10 soil subtypes listed in a hierarchical order. The subtypes may be combined if the soil has diagnostic features of more than one soil subtypes. Clear rules of soil name generalization (reduction of subtype number for one soil) were suggested for soil cartography on various scales. One of the most important among the distinguished soil sub-types are the “eroded” or “truncated” clay-illuvial soils.

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Insights into Red Sea Brine Pool Specialized Metabolism Gene Clusters Encoding Potential Metabolites for Biotechnological Applications and Extremophile Survival

Marine Drugs ◽

10.3390/md17050273 ◽

2019 ◽

Vol 17 (5) ◽

pp. 273 ◽

Cited By ~ 2

Author(s):

Laila Ziko ◽

Mustafa Adel ◽

Mohamed N. Malash ◽

Rania Siam

Keyword(s):

Fatty Acids ◽

Red Sea ◽

Gene Clusters ◽

Specialized Metabolism ◽

Anticancer Effects ◽

Novel Drugs ◽

Atlantis Ii Deep ◽

Brine Pools ◽

Metabolism Gene ◽

Brine Pool

The recent rise in antibiotic and chemotherapeutic resistance necessitates the search for novel drugs. Potential therapeutics can be produced by specialized metabolism gene clusters (SMGCs). We mined for SMGCs in metagenomic samples from Atlantis II Deep, Discovery Deep and Kebrit Deep Red Sea brine pools. Shotgun sequence assembly and secondary metabolite analysis shell (antiSMASH) screening unraveled 2751 Red Sea brine SMGCs, pertaining to 28 classes. Predicted categorization of the SMGC products included those (1) commonly abundant in microbes (saccharides, fatty acids, aryl polyenes, acyl-homoserine lactones), (2) with antibacterial and/or anticancer effects (terpenes, ribosomal peptides, non-ribosomal peptides, polyketides, phosphonates) and (3) with miscellaneous roles conferring adaptation to the environment/special structure/unknown function (polyunsaturated fatty acids, ectoine, ladderane, others). Saccharide (80.49%) and putative (7.46%) SMGCs were the most abundant. Selected Red Sea brine pool sites had distinct SMGC profiles, e.g., for bacteriocins and ectoine. Top promising candidates, SMs with pharmaceutical applications, were addressed. Prolific SM-producing phyla (Proteobacteria, Actinobacteria, Cyanobacteria), were ubiquitously detected. Sites harboring the largest numbers of bacterial and archaeal phyla, had the most SMGCs. Our results suggest that the Red Sea brine niche constitutes a rich biological mine, with the predicted SMs aiding extremophile survival and adaptation.

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