The Role of Clay Mineral Composition on Silicified Coal Genesa Based on X-Ray Diffraction (XRD)

The interesting concern in this study is that in the same outcrop it was found that the first coal seam (coal seam-D) contains silicified coal and the second coal seam (coal seam-E) does not contain silicified coal and how to find out the cause. In general, the characteristics of silicified coal seam-D are in the form of lenses; the distribution extends from a few meters to several tens of meters with a thickness of three to five centimeters and some are in nodules. Environmental conditions are the main factor in the formation of silicified coal where the acidity level of coal bearing sediment seam-D which is between 3.4 (roof sediment) to 4.2 (floor sediment) is higher than coal bearing sediment seam-E which has a pH of 5.4. This condition indicates that the coal bearing sediment seam-D environment is more acidic than coal seam-E. The results of XRD analysis show that the seam-D containing silicified coal has a composition of 47.47% kaolinite, 21.27% illite, 23.73% smectite and 17.54% mixed layer, while the seam-E which does not contain silicified coal has a composition of kaolinite 35.78%, illite 17.88%, smectite 21.59% and mixed layer 24.76%. Acidic environmental conditions (pH) and silica enrichment in clay minerals (kaolinite) in the roof sediments during sedimentation, accelerated the process of deposition of colloidal silica in the wood structure of coal seams into silicified coal.

Silicified collagen scaffold induces semaphorin 3A secretion by sensory nerves to improve in-situ bone regeneration

Sensory nerves promote osteogenesis through the release of neuropeptides.However,the potential application and mechanism in which sensory nerves promote healing of bone defects in the presence of biomaterials remain elusive.The present study identified that new bone formation was more abundantly produced after implantation of silicified collagen scaffolds into defects created in the distal femur of rats.The wound sites were accompanied by extensive nerve innervation and angiogenesis.Sensory nerve dysfunction by capsaicin injection resulted in significant inhibition of silicon-induced osteogenesis in the aforementioned rodent model.Application of extracellular silicon in vitro induced axon outgrowth and increased expression of semaphorin 3 A(Sema3A)and semaphorin 4D(Sema4D)in the dorsal root ganglion(DRG),as detected by the upregulation of signaling molecules.Culture medium derived from silicon-stimulated DRG cells promoted proliferation and differentiation of bone marrow mesenchymal stem cells and endothelial progenitor cells.These effects were inhibited by the use of Sema3A neutralizing antibodies but not by Sema4D neutralizing antibodies.Knockdown of Sema3A in DRG blocked silicon-induced osteogenesis and angiogenesis almost completely in a femoral defect rat model,whereas overexpression of Sema3A promoted the silicon-induced phenomena.Activation of“mechanistic target of rapamycin”(mTOR)pathway and increase of Sema3A production were identified in the DRG of rats that were implanted with silicified collagen scaffolds.These findings support the role of silicon in inducing Sema3A production by sensory nerves,which,in turn,stimulates osteogenesis and angiogenesis.Taken together,silicon has therapeutic potential in orthopedic rehabilitation.

Rationale for creation of capillary breaking layers in cold regions subgrade by pressure injection of waterproofing compounds

In the presents work,the authors have carried out a field study of moisture transfer processes in highway subgrades in a cold region during freezing and laboratory experiments on freezing samples of silicified soils used as a capillary barrier.The study showed that the creation of a capillary barrier from an injected solution,blocking the access of groundwater to the freezing zone,will reduce the amount of heaving to permissible values.Based on the results of laboratory studies,an exponential dependence of the relative deformation due to frost heaving on the relative height of soil silicatization in the freezing zone has been established.For creating a capillary barrier in the already existing subgrade,the authors have proposed designs of injection-silicified soils and substantiated the use of such soils.

Diatoms’ Breakthroughs in Biotechnology: <i>Phaeodactylum tricornutum</i>as a Model for Producing High-Added Value Molecules

With a world growing in population and nutritional needs, diatoms are considered nowadays as microalgae of a very important potential, thus they are exploited in several fields such as ecology, aquaculture, molecular farming, and pharma nutraceuticals. These coveted microalgae are characterized by their diversity, their high division rates, their complex life cycle, likewise their silicified cell walls named frustules. Thus, diatoms have been used for over a century after proving an efficient production of several molecules including Triacylglycerols (TAGs), H2, free fatty acids, vitamins, nutraceuticals, amino acids, proteins, terpenoids, alcohols and carbohydrates like starch, glycogen, and sucrose. Phaeodactylum tricornutum is the most promising diatom exploited to date, especially as a platform of pharmaceutical production. Herein, we expose diatoms’ main features that allowed using them for molecular farming. This review exposes likewise, the metabolism and the post-translational modifications (PTMs) of diatoms as well as current tools and challenges for their molecular and metabolic engineering for a more efficient production of valuable molecules. The knowledge on the biology of the diatoms, the molecular tools, and the various transformation methods available demonstrate the potential in biotechnology of these photosynthetic microorganisms. The widely studied P. tricornutum, as a model organism, is a promising diatom for production of valuable metabolites, despite the challenges and issues related to cultivation.

Investigation and Evaluation of Reservoir Quality of the Upper Cretaceous Rocks (Belqa Group) in North Jordan (NW Irbid)

Upper Cretaceous rocks are widespread in Jordan, covering uncomfortably the rocks of the Lower Cretaceous (Kurnub Sandstone). These rocks consist mainly of limestone, marls, chalk, biogenic chert and phosphate of primarily marine origin. Age determination of these rocks was based on the abundance of macro and microfossil content. Man researchers subdivided the Upper Cretaceous succession. The classification of Powell (1989) is considered in this study, particularly for the Belqa Group, which is of Coniacian to Maastrichtian in age. This investigation will focus on the geology of Wadi Es Sir, Umm Ghudran;Amman silicified limestone, and Al Hisa phosphorite formations, that belong to Ajlun and Belqa Groups respectively. Moreover, sedimentary structures, lithological characteristics Microfacies types and fossil content were evaluated. Using the lithostratigraphy and the fossil content of those formations, 6 Microfacies types were identified. Evaluation of the cross-section, the tectonic processes and the prepared rose diagrams indicate that the study area was affected by compressional as well as by tensional forces. Two major tends of fracturing can be identified in the rose diagrams. The measured physical properties show that the porosity is variable and ranges between 30% and 48%. The bulk density has values between 1.8 and 2.2 g/cm3. The different obtained results point out that the studied rocks represent good reservoir.