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This paper aims to evaluate the influence of initial temperature of fresh concrete on compressive strength and degree of reactions of binder in concrete with and without fly ash. The aggregates are cooled before being used to mix the concrete to achieve the temperatures of fresh concrete of 18°C, 25°C, and 30°C. After 24 hours in the mould, the concrete specimens are continually cured in water at 28 ± 2°C. Test results indicate that the compressive strength of the concrete at an early age decreases when the initial temperature of the fresh concrete decreases. However, the compressive strength of concrete at 91 days increases in the case of low initial temperature of fresh concrete. The effect of initial cooling is more obvious in concrete with higher fly ash content. The bound water, degree of reactions, and C-S-H content, the paste samples were analyzed by TGA. The lower initial temperature of fresh concrete leads to a lower rate of the degree of reaction and produces less amount of C-S-H at an early age. The degree of reaction of the binder at an early age affects early strength and long-term pozzolanic reaction that causes long-term strength. A lower initial temperature of fresh concrete reduces the early hydration of cement and delays the start of the pozzolanic reaction, resulting in an enhancement of the compressive strength at later ages. The degree of reaction and C-S-H content correlated well with the compressive strength of the concrete at early and long-term ages.

Monkey head mushrooms (Hericium erinaceus (Bull.: Fr.) Pers) have been broadly cultivated and widely consumed as traditional medicinal herbs as well as functional food in the Orient for several hundred years of history. The identification of optimal culture conditions for mycelium growth and fruiting body formation is one of the most important steps in cultivation of mushroom. The aim of this study was to investigate the optimal culture conditions including pH level, temperature, media and substrate mixtures for the mycelium growth and cultivation of Hericium erinaceus strain He-2. Results of the study revealed that the optimal conditions for mycelial growth were observed at 25 ± 1 o C and pH 8.0. H. erinaceus was cultured on five different types of culture media: Czapek, Raper, PGA (potato, glucose, agar), PGA supplemented with rice bran, and PGA supplemented with fresh mushrooms. PGA supplemented with fresh mushrooms was found to be the best medium for the growth of mycelia. A media containing 99% grain of rice + 1% CaCO3 was considered as the best mother spawn media for mycelial growth. Among various culture media, the highest mycelium growth rate and biological efficiency of H. erinaceus were obtained when grown on a treatment of 87% sawdust + 4% corn bran + 8% rice bran + 1% CaCO3.

In this study, an unknown mushroom species collected on rotting trunks of Ficus elastica in the Hanoi Botanical Garden was investigated. It was designated as Bt116. Based on the observed morphological characteristics, such as irregularly semi-circular, slightly yellow pileus; very soft, homogeneous, spongy, creamy white context; short and not clear stipes; and basidiospores typical of ganoderma mushrooms, etc., we hypothesized that Bt116 belongs to the Tomophagus Murr. mushroom genus. Some biological characteristics of the Bt116 strain were made. The results indicated that the temperature 35°C was optimal for Bt116 mycelial growth; an alkaline environment (pH 8.0) was conducive for the mycelial growth of Bt116 among a range of pH levels from 4.0 to 9.0; aerobic conditions were better than anaerobic conditions for the growth of Bt116 mycelium; and lighting time showed no significant effects on the growth of Bt116 mycelium.