Evolution of Cracks in Nano-CaCO3 Modified Pre-Disintegrated Carbonaceous Mudstone Under Cyclic Wetting and Drying

2020 ◽  
Vol 20 (8) ◽  
pp. 5117-5122
Author(s):  
Ling Zeng ◽  
Yurong Yuan ◽  
Junhui Zhang
Keyword(s):  
Electron Microscopy ◽  
Rapid Development ◽  
Development Stage ◽  
Crack Evolution ◽  
Wetting And Drying ◽  
Ph Values ◽  
Three Stages ◽  
Final Crack ◽  
Scanning Electron ◽  
Stable Stage

To explore the evolution of cracks in the pre-disintegrated carbonaceous mudstone, wetting-drying tests were carried out on nano-CaCO3 modified pre-disintegrated carbonaceous mudstone samples. The samples were prepared with aqueous solutions of different pH values. Scanning electron microscopy (SEM) was performed to clarify the mechanism of crack evolution of pre-disintegrated carbonaceous mudstone modified by nano-CaCO3. The results showed that development of shrinkage and cracks was basically divided into three stages, i.e., the gestation stage, the rapid development stage and the stable stage. For the samples without nano-CaCO3, the final crack rates and pore sizes of samples with pH = 3 and pH = 11 were larger than corresponding values of the sample with pH= 7. Moreover, final crack rate and pore size significantly decreased with the addition of nano-CaCO3 suggesting that nano-CaCO3 can effectively improve cracking resistance of pre-disintegrated carbonaceous mudstone.

Fatigue Test Studies on Reinforced Concrete Hollow Slab Girder

2013 ◽  
Vol 787 ◽  
pp. 825-828
Author(s):  
Hong Bing Zhu ◽  
Yao Zhao ◽  
Bo Xia
Keyword(s):  
Reinforced Concrete ◽  
Rapid Development ◽  
Fatigue Loading ◽  
Development Stage ◽  
Damage Development ◽  
Highway Engineering ◽  
Three Stages ◽  
Last Stage ◽  
Number Of Cycles ◽  
Stable Stage

Reinforced Concrete (RC) Hollow Slab Girder is widely used in Highway Engineering, and fatigue load is an essential aspect of causing damage. In order to accurately calculate the distribution and development laws of RC hollow slab girder fatigue strain, experiment on Amplitude fatigue with five experimental beams were done in the laboratory. The beams obviously presented a rule of three stages: the damage development is fast in fore period and later period; but the hazard from fatigue in the midterm developed steadily relatively. The destruction of fatigue damage is the steel brittle fracture. Fatigue failure could be divided into three periods: rapid development stage, stable stage and destruction stage. In last stage one or two main cracks continues to expand, the rest stop growing and gradually closed, it fatigue fractured at the main crack. With the increase of the number of cycles of fatigue loading, the growth rate slowed down into a relatively stable stage, when approaching destruction there is relatively substantially growth.

Characterization of red sternum syndrome in mud crab farms from Thailand

Biologia ◽  
2010 ◽  
Vol 65 (1) ◽  
Author(s):  
Mayuva Areekijseree ◽  
Thanaporn Chuen-Im ◽  
Busaba Panyarachun
Keyword(s):  
Electron Microscopy ◽  
Cell Walls ◽  
Scylla Serrata ◽  
Mud Crab ◽  
Internal Organs ◽  
Three Stages ◽  
Severity Of The Disease ◽  
Claw Muscle ◽  
Scanning Electron

AbstractSamples of abnormal mud crabs, Scylla serrata (Forskål, 1755) (Decapoda: Portunidae), were collected from crab farms in Samutsongkhram Province, Thailand. These crabs had hard carapaces, red chelipeds and joints, pale hepatopancreas, gills, and soft muscles. They were almost immobile and finally died. The haemolymph revealed three stages of the syndrome, namely orange, orange-white, and milky-white in colors. The haemolymph, integument, hepatopancreas, gills, abdominal and claw muscle, stomach, and heart were dissected and histologically examined using transmission and scanning electron microscopy. Closer examinations found infection with rod-, curve rod-, or coccus-shape bacteria with thin and thick cell walls in all investigated organs and haemolymph. Isolation of the microorganisms from the infected tissues of red sternum syndrome crabs resulted in five types of bacteria. No microorganism growth was observed in normal crabs. Interestingly, the types of isolated bacteria can be classified according to the severity of the disease. Additionally, the degree of bacterial infection found was consistent with the stages of the disease. It was postulated that the bacteria entered the crabs via the gills, and then migrated through circulating haemocytes, before reaching the internal organs.

Development of the neotropical catfish Rhamdia quelen (Siluriformes, Heptapteridae) incubated in different temperature regimes

Zygote ◽  
2009 ◽  
Vol 18 (2) ◽  
pp. 131-144 ◽  
Author(s):  
Alana Marielle Rodrigues-Galdino ◽  
Camila Valente Maiolino ◽  
Mariana Forgati ◽  
Lucélia Donatti ◽  
Jorge Daniel Mikos ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Developmental Stages ◽  
Larval Period ◽  
Early Juvenile ◽  
Temperature Regimes ◽  
Rhamdia Quelen ◽  
Different Temperatures ◽  
Three Stages ◽  
Chemosensory Systems ◽  
Scanning Electron

SummaryThe developmental stages for the embryonic and larval periods of the silver catfish (Rhamdia quelen) kept at different temperatures (21, 24, 27 and 30°C) are described. Fish were analysed under light and scanning electron microscopy. For embryonic development, we described 25 stages, which were grouped into seven periods named zygote, cleavage, blastula, gastrula, segmentation, pharyngula and hatching periods. For larval development, we defined three stages (early, mid, and late larvae). Additionally, the main ontogenetic events during the post-larvae and early juvenile periods were also described. This species presents a well developped lateral line and chemosensory systems that grow up during the larval period, maturing in the post-larvae. All tested temperatures are viable to R. quelen development, but a shorter incubation period was necessary to complete the development at lower temperatures. However, some malformations (heart edema) were verified at 30°C.

A Rapid Setting TTCP-DCPD Cement. Study of the Setting Reaction as a Function of Time

2005 ◽  
Vol 284-286 ◽  
pp. 15-18 ◽  
Author(s):  
E.F. Burguera ◽  
Francisco Guitián ◽  
Laurence C. Chow
Keyword(s):  
Electron Microscopy ◽  
Rapid Development ◽  
Dicalcium Phosphate Dihydrate ◽  
Tetracalcium Phosphate ◽  
Setting Reaction ◽  
Scanning Electron Microscopy Examination ◽  
Phosphate Dihydrate ◽  
Rapid Setting ◽  
Microscopy Examination ◽  
Scanning Electron

The progression of the setting reaction of a tetracalcium phosphate (TTCP) –dicalcium phosphate dihydrate (DCPD) rapid setting cement was investigated as a function of time. Compressive strength and extent of conversion to hydroxyapatite (HA) were obtained at different incubation times. The results indicated a rapid development of both strength and HA conversion in the early stages of the reaction, which slowed down after 4 h, presumably as a result of HA formation on the surface of the reactants. This hypothesis was supported by scanning electron microscopy examination of cement fracture surfaces.

scholarly journals The Progress of Global Antimicrobial Resistance Governance and Its Implication to China: A Review

Antibiotics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1356
Author(s):  
Jia Yin ◽  
Yu Wang ◽  
Xueran Xu ◽  
Yinqi Liu ◽  
Lu Yao ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Central Government ◽  
Rapid Development ◽  
Development Stage ◽  
Policy Recommendations ◽  
Official Document ◽  
Global Trend ◽  
Global Action ◽  
Three Stages ◽  
Catch Up

China has great potential for engaging in global actions on antimicrobial resistance (AMR) control. This study aims to summarize the process of global AMR governance and provide relevant policy recommendations on how China could take more initiative in the global AMR governance. We searched for academic articles and official document published or issued before December 2020 in e-journal databases, official websites of major organizations, and the relevant national ministries. This review revealed that global action on AMR control has experienced three stages: (1) The beginning stage (1980s and 1990s) when actions were mainly sponsored by high-income countries and AMR surveillance was focused on hospitals; (2) The rapid development stage (2000–2010) when global AMR governance began to concentrate on joint actions in multi-sectors, and developing countries were gradually involved in global actions; (3) The comprehensive stage (2011 to present) when global actions on AMR have covered various fields in different countries. China’s AMR governance has fallen behind at the beginning but recently began to catch up with the global trend. The central government should take a far-fetched view, act decisively and positively towards the global efforts of addressing AMR to play a more active and greater role on the international stage.

scholarly journals MODIFIKASI KOPOLIMER KARET ALAM SIKLIS GRAFTING ASAM OLEAT MENGGUNAKAN INISIATOR BENZOIL PEROKSIDA DAN BAHAN PENGISI BENTONIT-CETIL TRIMETIL AMONIUM BROMIDA

2018 ◽  
Vol 16 (1) ◽  
pp. 40
Author(s):  
Ahmad Hafizullah Ritonga ◽  
Barita Aritonang ◽  
Liver Iman Putra Zai
Keyword(s):  
Electron Microscopy ◽  
Oleic Acid ◽  
Natural Rubber ◽  
Ammonium Bromide ◽  
Second Stage ◽  
The Third ◽  
Third Stage ◽  
Ft Ir ◽  
Three Stages ◽  
Scanning Electron

Research on the modification of Cyclic Natural Rubber (CNR) grafting Oleic Acid (OA) copolymer using initiator of Benzoyl Peroxide (BPO) and the filler of bentonite-Cetil Trimethyl Ammonium Bromide (CTAB) has been carried out, which aims to determine the method of modifying Cyclic Natural Rubber (CNR) and Oleic Acid (OA) so it can produce CNR-g-OA copolymer through grafting method with BPO initiator mixed together with bentonite-CTAB. This research was conducted in three stages. The first stage is the process of dissolving CNR using xylene. The second stage is the process of mixing CNR solution and OA with the composition (70:30) phr, followed by the addition of BPO initiator and bentonite-CTAB filler. The third stage is characterization using FTIR and Scanning Electron Microscopy (SEM). The results of the analysis using FT-IR showed an absorption at 1708,23 cm-1 which indicated the presence of C=O bonds from oleic acid which had been grafted on CNR, and increased intensity after addition of bentonite-CTAB at 1568,96 cm-1; 1446,13 cm-1; 1255,66 cm-1; and 866,94 cm-1. Characterization results using SEM showed that the mixing of Bentonite-CTAB in KAS-g-OA was evenly distributed and quite homogeneous.

scholarly journals Synthesis and solubility of brompyromorphite Pb5(PO4)3Br

Mineralogia ◽  
2012 ◽  
Vol 43 (1-2) ◽  
pp. 129-135 ◽  
Author(s):  
Urszula Janicka ◽  
Tomasz Bajda ◽  
Maciej Manecki
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Solubility Product ◽  
X Ray Diffraction ◽  
Ph Measurements ◽  
X Ray ◽  
Ph Values ◽  
Free Energy Of Formation ◽  
Scanning Electron ◽  
Energy Of Formation

AbstractThe bromide analogue of pyromorphite Pb5(PO4)3Br was synthesized and characterized by X-ray diffraction, infrared spectroscopy and scanning electron microscopy. The solubility of the brompyromorphite was measured at 25°C and pH values of 2.0, 2.6 and 3.2. For the 3 pH measurements, the average solubility product, log KSP, for the reaction Pb5(PO4)3Br ⇔ 5Pb2+ + 3PO- 3- + Br- at 25ºC is -77.38 ± 0.70. The free energy of formation, ΔG°f,298, calculated from this measured solubility product is -3724.7 ± 4.3 kJ mol−1. These results confirm that brompyromorphite is more soluble than pyromorphite.

Corrosion in Tinplate Cans Used for Food Storage. Part 3: Effects of Cysteine, NaCl, and Tomatoes on Corrosion of Tin, Iron and Tinplate

CORROSION ◽  
10.5006/3963 ◽  
2021 ◽  
Author(s):  
Kuo-Hsiang Chang ◽  
Belinda Hurley ◽  
Melvin Pascall ◽  
Gerald Frankel
Keyword(s):  
Electron Microscopy ◽  
Chemical Compounds ◽  
Corrosion Products ◽  
Food Storage ◽  
Chemical Components ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ph Values ◽  
Polymeric Layer ◽  
Scanning Electron

Tinplate cans used to contain foodstuff are fabricated from steel coated with a thin layer of tin and then overcoated with a thin polymeric layer. Previous papers in this series investigated the corrosion behavior of tinplate cans containing chopped tomatoes or one of the chemical components found in cans of chopped tomatoes. The amino acid cysteine was found to be an aggressive agent that can cause corrosion and blackening of the can headspace region. In this study, the corrosion phenomena associated with tinplate cans were investigated by studying the behavior, individually, of uncoated pure tin, iron, and tinplate in chopped tomato, NaCl, and cysteine solutions using electrochemistry, optical microscopy, X-ray diffraction, scanning electron microscopy, and Raman spectroscopy. Black corrosion products, identified as sulfides, formed when the tin, iron, and tinplate specimens were exposed to cysteine solution at three different pH values. The black corrosion products were also found on both iron and tinplate when the samples were immersed in tomato solution. These results indicate that blackening on bare iron and tinplate could form easily from the decomposition of chemical compounds in heated tomatoes.

scholarly journals Evolution of Guangzhou Biomedical Industry Innovation Network Structure and Its Proximity Mechanism

2020 ◽  
Vol 12 (6) ◽  
pp. 2456
Author(s):  
Kaihuang Zhang ◽  
Qinglan Qian ◽  
Yijing Zhao
Keyword(s):  
Topological Structure ◽  
Rapid Development ◽  
Development Stage ◽  
Innovation Network ◽  
Policy Recommendations ◽  
Biomedical Industry ◽  
Three Stages ◽  
Innovation Cooperation ◽  
Different Characteristics ◽  
The Relationship

The topological structure and multidimensional proximity evolution mechanism of Guangzhou biomedical industry innovation network are studied by using cooperative patents and cooperative papers from 1998 to 2018 with Ucinet and PLS-SEM. Research shows: ① The evolution of the Guangzhou Biomedical Industry Innovation Network can be divided into three stages, which are the primary budding stage of 1998–2005, the steady development stage of 2006–2012, and the rapid development stage of 2013–2018; ② the number of subjects in the innovation network is increasing, and the types of subjects are constantly increasing. The innovation network has gone from small to large, from closed to open, and from simple to complex. Patents and papers cooperation networks show different characteristics at various stages; ③ the relationship between geographical proximity, cognitive proximity, organizational proximity, and innovation network differs in stages. The interaction of proximity varies with the content of innovation cooperation. Based on this result, we have put forward policy recommendations for different innovative content.

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