Remoulded Strength of High Plasticity Marine Silt Retrieved from Maintenance Dredging

Nearshore’s facilities are often require frequent and regular maintenance dredging in maintaining appropriate water depths and enlarging the access channel and turning basin. A large amount of sediment was spawned from the dredging work. The dredged marine sediments (DMS) are not apt to be used in construction activities because of its poor geophysical properties. The purpose of this research is to study the improvement in moisture content and strength of DMS by using electrokinetic (EK) method. DMS are classified as a high plasticity silt (MH) with 240.74 % of its natural water content. Stainless steel plate was invoked as the electrode, while distilled water (DW), citric acid (CA) and calcium chloride (CaCl2) were applied as the stabilizing agents. The aforementioned stabilizers are electrically injected into the DMS which causing flow of the solutions through the pores in DMS under 50 V/m of applied direct current (DC). The results of treated DMS are presented in moisture content, undrained shear strength and SEM-EDX analysis. The EK treated DMS shows it increases in strength in the dry zone area after the 14 days treatment. The dry zone area was created near the anode and wet zone was made near the cathode. The application of calcium ions in the treatment had increased the strength and alters the pattern of the soil fabric. Largely, EK has significantly improved the quality of DMS even though the strength increase observed was not homogeneous throughout the specimen.

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Maintenance Dredging Required after Port Extensions at Walvis Bay

Coastal Engineering 1998 ◽

10.1061/9780784404119.262 ◽

1999 ◽

Author(s):

R C Coppoolse ◽

J S Schoonees

Keyword(s):

Maintenance Dredging

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Impacts of Navigation Channel Maintenance Dredging on the Coastal Processes of Chatham, Massachusetts

10.21236/ada400385 ◽

2001 ◽

Cited By ~ 2

Author(s):

Donald K. Stauble

Keyword(s):

Coastal Processes ◽

Navigation Channel ◽

Channel Maintenance ◽

Maintenance Dredging

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Assessing population collapse of Drupella spp. (Mollusca: Gastropoda) 2 years after a coral bleaching event in the Republic of Maldives

Hydrobiologia ◽

10.1007/s10750-021-04546-5 ◽

2021 ◽

Author(s):

L. Saponari ◽

I. Dehnert ◽

P. Galli ◽

S. Montano

Keyword(s):

Coral Bleaching ◽

Prey Availability ◽

Coral Cover ◽

Environmental Data ◽

High Plasticity ◽

Bleaching Event ◽

Coral Recovery ◽

The Republic ◽

The Impact ◽

Line Intercept

AbstractCorallivory causes considerable damage to coral reefs and can exacerbate other disturbances. Among coral predators, Drupella spp. are considered as delayer of coral recovery in the Republic of Maldives, although little information is available on their ecology. Thus, we aimed to assess their population structure, feeding behaviour and spatial distribution around 2 years after a coral bleaching event in 2016. Biological and environmental data were collected using belt and line intercept transects in six shallow reefs in Maldives. The snails occurred in aggregations with a maximum of 62 individuals and exhibited a preference for branching corals. Yet, the gastropods showed a high plasticity in adapting feeding preferences to prey availability. Drupella spp. were homogenously distributed in the study area with an average of 9.04 ± 19.72 ind/200 m2. However, their occurrence was significantly different at the reef scale with the highest densities found in locations with higher coral cover. The impact of Drupella spp. appeared to be minimal with the population suffering from the loss of coral cover. We suggest that monitoring programs collect temporal- and spatial-scale data on non-outbreaking populations or non-aggregating populations to understand the dynamics of predation related to the co-occurrence of anthropogenic and natural impacts.

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The Interface Zone of Explosively Welded Titanium/Steel after Short-Term Heat Treatment

Metallurgical and Materials Transactions A ◽

10.1007/s11661-021-06174-z ◽

2021 ◽

Author(s):

Marcin Szmul ◽

Katarzyna Stan-Glowinska ◽

Marta Janusz-Skuza ◽

Agnieszka Bigos ◽

Andrzej Chudzio ◽

...

Keyword(s):

Heat Treatment ◽

Intermetallic Phase ◽

Welding Process ◽

Carbon Diffusion ◽

Sharp Interface ◽

High Plasticity ◽

Interface Zone ◽

Before And After ◽

Wavy Interface ◽

The Waves

AbstractThis work presents a detailed description of a bonding zone of explosively welded Ti/steel clads subjected to stress relief annealing, applied in order to improve the plasticity of the final product. The typical joint formed by the welding process possesses a characteristic wavy interface with melted regions observed mainly at the crest regions of waves. The interface of Ti/steel clads before and after annealing was previously investigated mostly in respect to the melted regions. Here, a sharp interface between the waves was analyzed in detail. The obtained results indicate that the microstructure of a transition zone of that area is different along the width. After the heat treatment at 600 °C for 1.5 hours, titanium carbide (TiC) together with α-Fe phase forms at the interface in local areas of relatively wide interlayer (~ 1 µm), while for most of the sharp interface, a much thinner zone up to about 400 nm, formed by four sublayers containing intermetallic phase and carbides, is present. This confirms that carbon diffusion induced by applied heat treatment significantly influences the final microstructure of the Ti/steel interface zone. Side bending tests confirmed high plasticity of welds after applied heat treatment; however, the microhardness measurements indicated that the strengthening of the steel in the vicinity of the interface had not been removed completely.

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Iron Released after Cryo-Thermal Therapy Induced M1 Macrophage Polarization, Promoting the Differentiation of CD4+ T Cells into CTLs

International Journal of Molecular Sciences ◽

10.3390/ijms22137010 ◽

2021 ◽

Vol 22 (13) ◽

pp. 7010

Author(s):

Shicheng Wang ◽

Man Cheng ◽

Peng Peng ◽

Yue Lou ◽

Aili Zhang ◽

...

Keyword(s):

T Cells ◽

Cd4 T Cells ◽

Antitumor Immunity ◽

Macrophage Polarization ◽

Thermal Therapy ◽

High Plasticity ◽

Antitumor Effects ◽

M1 Macrophages ◽

Splenic Macrophages ◽

M1 Macrophage

Macrophages play critical roles in both innate and adaptive immunity and are known for their high plasticity in response to various external signals. Macrophages are involved in regulating systematic iron homeostasis and they sequester iron by phagocytotic activity, which triggers M1 macrophage polarization and typically exerts antitumor effects. We previously developed a novel cryo-thermal therapy that can induce the mass release of tumor antigens and damage-associated molecular patterns (DAMPs), promoting M1 macrophage polarization. However, that study did not examine whether iron released after cryo-thermal therapy induced M1 macrophage polarization; this question still needed to be addressed. We hypothesized that cryo-thermal therapy would cause the release of a large quantity of iron to augment M1 macrophage polarization due to the disruption of tumor cells and blood vessels, which would further enhance antitumor immunity. In this study, we investigated iron released in primary tumors, the level of iron in splenic macrophages after cryo-thermal therapy and the effect of iron on macrophage polarization and CD4+ T cell differentiation in metastatic 4T1 murine mammary carcinoma. We found that a large amount of iron was released after cryo-thermal therapy and could be taken up by splenic macrophages, which further promoted M1 macrophage polarization by inhibiting ERK phosphorylation. Moreover, iron promoted DC maturation, which was possibly mediated by iron-induced M1 macrophages. In addition, iron-induced M1 macrophages and mature DCs promoted the differentiation of CD4+ T cells into the CD4 cytolytic T lymphocytes (CTL) subset and inhibited differentiation into Th2 and Th17 cells. This study explains the role of iron in cryo-thermal therapy-induced antitumor immunity from a new perspective.

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Characterization of Al2O3 Samples and NiAl–Al2O3 Composite Consolidated by Pulse Plasma Sintering

Materials ◽

10.3390/ma14123398 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3398

Author(s):

Katarzyna Konopka ◽

Marek Krasnowski ◽

Justyna Zygmuntowicz ◽

Konrad Cymerman ◽

Marcin Wachowski ◽

...

Keyword(s):

Fracture Toughness ◽

Mechanical Alloying ◽

Ceramic Composites ◽

Pulse Plasma ◽

High Plasticity ◽

Composite Powders ◽

Microstructural Investigation ◽

Al2o3 Powder ◽

Plasma Sintering ◽

Pulse Plasma Sintering

The paper describes an investigation of Al2O3 samples and NiAl–Al2O3 composites consolidated by pulse plasma sintering (PPS). In the experiment, several methods were used to determine the properties and microstructure of the raw Al2O3 powder, NiAl–Al2O3 powder after mechanical alloying, and samples obtained via the PPS. The microstructural investigation of the alumina and composite properties involves scanning electron microscopy (SEM) analysis and X-ray diffraction (XRD). The relative densities were investigated with helium pycnometer and Archimedes method measurements. Microhardness analysis with fracture toughness (KIC) measures was applied to estimate the mechanical properties of the investigated materials. Using the PPS technique allows the production of bulk Al2O3 samples and intermetallic ceramic composites from the NiAl–Al2O3 system. To produce by PPS method the NiAl–Al2O3 bulk materials initially, the composite powder NiAl–Al2O3 was obtained by mechanical alloying. As initial powders, Ni, Al, and Al2O3 were used. After the PPS process, the final composite materials consist of two phases: Al2O3 located within the NiAl matrix. The intermetallic ceramic composites have relative densities: for composites with 10 wt.% Al2O3 97.9% and samples containing 20 wt.% Al2O3 close to 100%. The hardness of both composites is equal to 5.8 GPa. Moreover, after PPS consolidation, NiAl–Al2O3 composites were characterized by high plasticity. The presented results are promising for the subsequent study of consolidation composite NiAl–Al2O3 powder with various initial contributions of ceramics (Al2O3) and a mixture of intermetallic–ceramic composite powders with the addition of ceramics to fabricate composites with complex microstructures and properties. In composites with complex microstructures that belong to the new class of composites, in particular, the synergistic effect of various mechanisms of improving the fracture toughness will be operated.

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Dental Pulp-Derived Mesenchymal Stem Cells for Modeling Genetic Disorders

International Journal of Molecular Sciences ◽

10.3390/ijms22052269 ◽

2021 ◽

Vol 22 (5) ◽

pp. 2269

Author(s):

Keiji Masuda ◽

Xu Han ◽

Hiroki Kato ◽

Hiroshi Sato ◽

Yu Zhang ◽

...

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Dental Pulp ◽

Genetic Disorders ◽

In Vitro Models ◽

High Plasticity ◽

Human Teeth ◽

Clinical Diagnoses ◽

Models Of Disease

A subpopulation of mesenchymal stem cells, developmentally derived from multipotent neural crest cells that form multiple facial tissues, resides within the dental pulp of human teeth. These stem cells show high proliferative capacity in vitro and are multipotent, including adipogenic, myogenic, osteogenic, chondrogenic, and neurogenic potential. Teeth containing viable cells are harvested via minimally invasive procedures, based on various clinical diagnoses, but then usually discarded as medical waste, indicating the relatively low ethical considerations to reuse these cells for medical applications. Previous studies have demonstrated that stem cells derived from healthy subjects are an excellent source for cell-based medicine, tissue regeneration, and bioengineering. Furthermore, stem cells donated by patients affected by genetic disorders can serve as in vitro models of disease-specific genetic variants, indicating additional applications of these stem cells with high plasticity. This review discusses the benefits, limitations, and perspectives of patient-derived dental pulp stem cells as alternatives that may complement other excellent, yet incomplete stem cell models, such as induced pluripotent stem cells, together with our recent data.

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