The Application of Seabed Silt in the Preparation of Artificial Algal Reefs

Large amounts of silt have been deposited on the seabed in China’s coastal areas due to intensive coastal development and marine raft aquaculture, which are the main causes of local marine environmental disasters. In this study, seabed silt was tested as a potential raw material for artificial reefs. The silt was mixed with cement in four proportions to create concrete specimens for use in silt artificial reefs (SARs). The compressive strength development and nutrient dissolution were examined in the SAR specimens. The hydration products of the SAR paste were investigated through X-ray diffraction (XRD), scanning election microscope (SEM), and differential scanning calorimetry (DSC) techniques. The results showed that the compression strength of the SAR specimens was inversely proportional to their seabed silt content. The SAR specimens were able to continuously dissolve nitrogen-containing nutrients. The presence of Ca(OH)2, commonly found in traditional concrete, was not detected, which may help improve the seaweed adhesion and biological effects of artificial reefs. The effective utilization of seabed silt could serve to restore and improve the marine ecological environment.

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Mannosylated Solid Lipid Nanocarriers Of Chrysin To Target Gastric Cancer: Optimization and Cell line Study.

Current Drug Delivery ◽

10.2174/1567201818666210319142206 ◽

2021 ◽

Vol 18 ◽

Author(s):

Sonia S. Pandey ◽

Farhinbanu I. Shaikh ◽

Arti R. Gupta ◽

Rutvi J. Vaidya

Keyword(s):

Gastric Cancer ◽

Particle Size ◽

Ex Vivo ◽

Biological Effects ◽

Entrapment Efficiency ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Solid Lipid ◽

Lipid Nanocarriers

Background: Despite significant biological effects, the clinical use of chrysin has been restricted because of its poor oral bioavailability. Objective: The purpose of the present research was to investigate the targeting potential of Mannose decorated chrysin (5,7- dihydroxyflavone) loaded solid lipid nanocarrier (MC-SLNs) for gastric cancer. Methods: The Chrysin loaded SLNs (C-SLNs) were developed optimized, characterized and further mannosylated. The C-SLNs were developed with high shear homogenizer, optimized with 32 full factorial designs and characterized by Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM) and evaluated for particle size/polydispersity index, zeta-potential, entrapment efficiency, % release and haemolytic toxicity. The ex-vivo cytotoxicity study was performed on gastric cancer (ACG) and normal cell lines. Results: DSC and XRD data predict the chrysin encapsulation in lipid core and FTIR results confirm the mannosylation of C-SLNs. The optimized C-SLNs exhibited a narrow size distribution with a particle size of 285.65 nm. The % Entrapment Efficiency (%EE) and % controlled release were found to be 74.43% and 64.83%. Once C-SLNs were coated with mannose, profound change was observed in dependent variable - increase in the particle size of MC-SLNs (307.1 nm) was observed with 62.87% release and 70.8% entrapment efficiency. Further, the in vitro studies depicted MC- SLNs to be least hemolytic than pure chrysin and C-SLNs. MC-SLNs were most cytotoxic and were preferably taken up ACG tumor cells as evaluated against C-SLNs. Conclusion: These data suggested that the MC-SLNs demonstrated better biocompatibility and targeting efficiency to treat the gastric cancer.

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Use of sweet sorghum bagasse (Sorghum bicolor (L.) Moench) for cellulose acetate synthesis

BioResources ◽

10.15376/biores.14.2.3534-3553 ◽

2019 ◽

Vol 14 (2) ◽

pp. 3534-3553

Author(s):

José M. da Silva Neto ◽

Líbia de S. C. Oliveira ◽

Flávio L. H. da Silva ◽

José N. Tabosa ◽

José G. A. Pacheco ◽

...

Keyword(s):

Cellulose Acetate ◽

Cellulose Triacetate ◽

Point Of View ◽

Raw Material ◽

Sodium Chlorite ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Sorghum Bagasse ◽

Chemical Inputs ◽

Sorghum Bicolor L

The objective of this work was to synthesize cellulose acetate from sorghum bagasse, a promising raw material for the production of chemical inputs, both from a photosynthetic point of view and the maturation speed compared with that of sugarcane. The bagasse was treated with hydrogen peroxide, and then cellulose was isolated using sodium chlorite, acetic acid, and sodium hydroxide. The cellulose was subjected to an acetylation reaction, from which cellulose triacetate was obtained. By means of statistical analysis, it was observed that the conditions that generated the highest solubilization of lignin (62%) and higher yield from cellulose extraction (39.5%) were 60 °C, a 6% peroxide concentration, and 4 h. Cellulose acetate was obtained with a degree of substitution of 3.66 at 25 °C and 24 h. Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetry, differential thermogravimetry, and differential scanning calorimetry analyses confirmed that the obtained cellulose presented specific characteristics of this material. Also, the reaction of acetylation was confirmed through these techniques.

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Evaluation of the long-term compressive strength development of the sewage sludge ash/metakaolin-based geopolymer

Materiales de Construcción ◽

10.3989/mc.2021.13220 ◽

2021 ◽

Vol 71 (343) ◽

pp. e254

Author(s):

D. Istuque ◽

L. Soriano ◽

M.V. Borrachero ◽

J. Payá ◽

J.L. Akasaki ◽

...

Keyword(s):

Compressive Strength ◽

Sewage Sludge ◽

Strength Development ◽

X Ray Diffraction ◽

Sewage Sludge Ash ◽

Dense Microstructure ◽

Compressive Strength Development ◽

Physicochemical Characterisation ◽

Sludge Ash

This paper aimed to evaluate the long-term compressive strength development of the sewage sludge ash/metakaolin (SSA/MK)-based geopolymer. SSA/MK-based geopolymeric mortars and pastes were produced at 25ºC with different SSA contents (0 - 30 wt.%). Compressive strength tests were run within the 3-720 curing days range. A physicochemical characterisation (X-ray diffraction and scanning electron microscopy) was performed in geopolymeric pastes. All the geopolymeric mortars presented a compressive strength gain with curing time. The mortars with all the SSA evaluated contents (10, 20, 30 wt.%) developed a compressive strength over 40 MPa after 720 curing days at 25ºC. The maximum compressive strength of the mortars with SSA was approximately 61 MPa (10 wt.% of SSA), similarly to the reference mortar (100% MK-based geopolymer). The microstructure analyses showed that the SSA/MK-based geopolymer presented a dense microstructure with N-A-S-H gel formation.

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Characterization of Li2O-Al2O3-SiO2 glass-ceramics produced from a Brazilian spodumene concentrate

Cerâmica ◽

10.1590/0366-69132019653752699 ◽

2019 ◽

Vol 65 (375) ◽

pp. 366-377 ◽

Cited By ~ 2

Author(s):

L. B. Rebouças ◽

M. T. Souza ◽

F. Raupp-Pereira ◽

A. P. Novaes de Oliveira

Keyword(s):

Structural Changes ◽

Glass Ceramics ◽

Nucleating Agent ◽

Raw Material ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Heating Microscopy ◽

Shock Resistance ◽

High Thermal Shock Resistance

Abstract Glass-ceramics in the LAS (Li2O-Al2O3-SiO2) system with high thermal shock resistance were successfully obtained using Brazilian spodumene concentrate as the main raw material (80-70 wt%). Two compositions (Li2O.Al2O3.nSiO2) were produced with n= 2 and 4, near to the stoichiometric compositions of β-eucryptite and β-spodumene. The characteristic temperatures of parent glasses were determined by contact dilatometry, differential scanning calorimetry and heating microscopy. The crystallization mechanism and the effect of the nucleating agent (TiO2.2ZrO2) required to promote volume crystallization in the parent glasses were investigated. Microstructural and structural changes with temperature were also evaluated by optical microscopy and X-ray diffraction. The obtained glass-ceramics presented coefficients of thermal expansion between -0.370x10-6 and 4.501x10-6 °C-1 in the 22 to 700 °C range.

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Reuse of Industrial and Agricultural Waste in the Fabrication of Geopolymeric Binders: Mechanical and Microstructural Behavior

Materials ◽

10.3390/ma14092089 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2089

Author(s):

Jordi Payá ◽

Lourdes Soriano ◽

Alba Font ◽

Maria Victoria Borrachero Rosado ◽

Javier Alejandro Nande ◽

...

Keyword(s):

Agricultural Waste ◽

Research Work ◽

Strength Development ◽

X Ray Diffraction ◽

Silica Source ◽

Compressive Strength Development ◽

Microstructural Behavior ◽

Alkali Activated ◽

Better Than ◽

Lower Carbon

Resource recovery from waste is one of the most important ways to implement the so-called circular economy, and the use of alkali activated materials can become an alternative for traditional PC-based materials. These types of materials are based on waste resources involving a lower carbon footprint and present similar or high properties and good durability compared to that Portland cement (PC). This research work proposes using new waste generated in different types of industries. Four waste types were employed: fluid catalytic cracking residue (FCC) from the petrochemical industry; ceramic sanitary ware (CSW) from the construction industry; rice husk ash (RHA); diatomaceous waste from beer filtration (DB) (food industry). FCC and CSW were employed as precursor materials, and mixtures of both showed good properties of the obtained alkali activated materials generated with commercial products as activators (NaOH/waterglass). RHA and DB were herein used as an alternative silica source to prepare the alkaline activating solution. Mechanical behavior was studied by the compressive strength development of mortars. The corresponding pastes were characterized by X-ray diffraction, thermogravimetric analysis, and microscopy studies. The results were satisfactory, and demonstrated that employing these alternative activators from waste produces alkali activated materials with good mechanical properties, which were sometimes similar or even better than those obtained with commercial reagents.

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Preparation and Composition Optimization of Low-CO2-Emission Cement Containing Belite, Calcium Sulfoaluminate and Ferrite

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.727.1067 ◽

2017 ◽

Vol 727 ◽

pp. 1067-1073 ◽

Cited By ~ 2

Author(s):

Wu Yao ◽

Qiao Ling ◽

Meng Xue Wu

Keyword(s):

Compressive Strength ◽

Cement Clinker ◽

Strength Development ◽

Optimal Composition ◽

X Ray Diffraction ◽

Scattered Electron ◽

X Ray ◽

Calcium Sulfoaluminate ◽

Compressive Strength Development ◽

Composition Optimization

Cement clinker with low CO2 emission was prepared in laboratory, which mainly consist of belite (C2S), calcium sulfoaluminate (C4A3S), and ferrite (C4AF). The mineral composition of clinker was optimized for better compressive strength development. The chemical and physical properties of this prepared cement were characterized through X-ray diffraction (XRD), back scattered electron-scanning electron microscopy (BSE-SEM) and differential thermal analysis (DTA). The results reveal that C4A3S governs most of the compressive strength at early ages, while C2S contributes to the later strength development. C4AF is in liquid when fired to 1300°C, beneficial to the mass transfer but causing high crystallinity of C2S when excessive. Finally the results of experiments suggest that the optimal composition of clinker is 50wt. % C2S, 40wt. % C4A3S and 10wt. % C4AF.

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Study of Polymorphs of Zirconia in the System ZrO2: ƞ wt% Re2O3 Obtained by Polymeric Precursor Method

Materials Science Forum ◽

10.4028/www.scientific.net/msf.727-728.1340 ◽

2012 ◽

Vol 727-728 ◽

pp. 1340-1344

Author(s):

R.A. Muñoz ◽

J.E. Rodriguez ◽

Cosme Roberto Moreira Silva

Keyword(s):

Rare Earth ◽

Rare Earth Elements ◽

Zirconium Oxide ◽

Pechini Method ◽

Synthesis Method ◽

Raw Material ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Dysprosium Oxide ◽

Transmission Electron

In this paper we propose the stabilization of zirconium oxide with controlled additions of a rare earth elements concentrate, in the system ZrO2: ƞ wt% Re2O3 (withƞ=5.36, 10.47, 13.74, 16.91 e 20) whereRe2O3is a rare earth elements concentrate composed mainly of 76.88% of yttrium oxide, 12.1% of Dysprosium oxide, 4.04% of Erbium oxide and 1.94% of Holmium oxide. The synthesis method used was the Pechini method. The results show that additions of 5.36 and 20 wt% of the concentrate are enough to stabilize the tetragonal and cubic zirconia phases respectively, and that zirconium oxide polymorphs can coexist with additions within these limit. In the characterization of the obtained powders are presented and discussed the following results: differential scanning calorimetry, transmission electron microscopy and X-ray diffraction. Also, it was necessary to make analysis by Rietveld refinement because they had severe overlap in the diffraction peaks. One of the most relevant results is obtaining a raw material, cheap to be used in many technological applications.

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Extraction of Al-Si master alloy and alumina from coal fly ash

Journal of Mining and Metallurgy Section B Metallurgy ◽

10.2298/jmmb160616006l ◽

2017 ◽

Vol 53 (2) ◽

pp. 155-162 ◽

Cited By ~ 5

Author(s):

A. Liu ◽

Z. Shi ◽

K. Xie ◽

X. Hu ◽

B. Gao ◽

...

Keyword(s):

Fly Ash ◽

Master Alloy ◽

Power Plants ◽

Coal Fly Ash ◽

Raw Material ◽

Aluminothermic Reduction ◽

Chemical Compositions ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

X Ray

Coal fly ash from coal power plants is a potential raw material for the production of alumina. An objective aluminothermic reduction method for the preparation of Al-Si master alloy and alumina from coal fly ash was investigated. The kinetic analysis using non-isothermal differential scanning calorimetry indicated that the reduction of Al6Si2O13, Fe2O3, and TiO2 by aluminum in coal fly ash occurs at 1618 K, 1681 K, and 1754 K, respectively. Moreover, the influence of reaction temperature on product composition was studied. The phases and morphologies of the products obtained by the aluminothermic reduction of coal fly ash at 1373-1773 K were analyzed by X-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy, respectively. The results from X-ray diffraction show that no oxide reduction has taken place at 1373 K and 1473K, the compositions of the product obtained by aluminothermic reduction of fly ash at 1573K- 1673 K are Al2O3, mullite, Al and Si, while the compositions of the product at 1773 K are Al2O3, Al, and Si. In addition, the chemical compositions of Al-Si alloy obtained at 1773 K are 86.81 wt% Al and 13.19 wt% Si.

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Crystal forms and phase transformation of 1,5-pentanediamine-terephthalate: a bio-based nylon 5T monomer

Acta Crystallographica Section B Structural Science Crystal Engineering and Materials ◽

10.1107/s2052520620006265 ◽

2020 ◽

Vol 76 (4) ◽

pp. 524-533

Author(s):

Zihan Li ◽

Pengpeng Yang ◽

Haodong Liu ◽

Jun Liu ◽

Sha Zhu ◽

...

Keyword(s):

Transition Temperature ◽

Water Activity ◽

Raw Material ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Phase Form ◽

Crystal Forms ◽

X Ray ◽

Thermodynamic Conditions ◽

Biomass Resources

Nylon 5T is one of the bio-based nylons, its raw material 1,5-pentanediamine is derived from biomass resources and produced by biological methods. 1,5-pentanediamine-terephthalate (PDA-TPA) is the monomeric salt for nylon 5T polymerization, and its own product quality has a significant impact on the performance of nylon 5T. PDA-TPA was prepared by anti-solvent crystallization in this study. It exists in two solid forms, a monohydrate [form (I)] and an anhydrous phase [form (II)]. The transition temperature of the two phases was around 65°C in the given ethanol–water binary (7:1) mixture. The characterization of monohydrate and anhydrate phases regarding structures and stabilities was carefully carried out using powder X-ray diffraction, single crystal X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, hot-stage microscopy and Fourier transform infrared spectroscopy. The relationship between the molecular interactions of monohydrate and anhydrate phases under different packing architectures and their thermal behaviours was analysed and established. In addition, the relationships between the structures and thermal behaviours for the two solid forms were analysed and established. In addition, the effect of solvent on phase conversion, the relationships between the temperature and water activity, as well as the relative stability of monohydrate and anhydrate phases under different thermodynamic conditions, were investigated by solid–solid transformation and solvent-mediated transformation experiments. It was obvious that the transition temperature of monohydrate and anhydrate phases of PDA-TPA was significantly influenced by water activity, and the larger the value of water activity is, the higher is the transition temperature. These studies give insight into the transformation of nylon 5T monomer salt and contribute to the control of target crystal preparation.

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Thermal Treatment on MSWI Bottom Ash for the Utilisation in Alkali Activated Materials

KnE Engineering ◽

10.18502/keg.v5i4.6792 ◽

2020 ◽

Author(s):

Boyu Chen ◽

Marc Brito van Zijl ◽

Arno Keulen ◽

Guang Ye

Keyword(s):

Thermal Treatment ◽

Bottom Ash ◽

Waste Incineration ◽

Raw Material ◽

Strength Development ◽

X Ray Diffraction ◽

Mswi Bottom Ash ◽

Alkaline Conditions ◽

Heating Up ◽

Alkali Activated

At present, most municipal solid waste incineration (MSWI) bottom ash is directly landfilled, raising concerns about environmental issues and loss of resources. Due to its high mineral content, MSWI bottom ash is now being considered as a raw material to prepare alkali-activated materials (AAMs). However, the mineral fraction unavoidably contains metallic aluminium (Al) and zinc (Zn) scraps (<1 wt.%), which easily oxidise and generate H2gas under alkaline conditions. As a result, when using MSWI bottom ash to prepare AAMs, the formation of a porous structure, as well as expansive cracks (both detrimental to strength development) can be observed. In this research, thermal treatment of MSWI bottom ash, at temperatures of 500 and 1000 °C, was performed to deal with the issue caused by metallic Al/Zn. A series of tests, including Quantitative X-ray diffraction (QXRD) analysis, fineness measurements (particle size and surface area), and the dissolution test, were conducted to examine the effects of thermal treatment on as-received bottom ash. The results indicate that it is difficult to oxidise metallic Al/Zn at 500°C, but heating up to 1000 °C can realize the complete oxidation of Al/Zn, which in turn allows the wide utilisation of bottom ash in AAMs. Keywords: MSWI bottom ash, thermal treatment, alkali-activated materials.

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