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Volume 6, Issue No 2, June 2019 <<Previous Volume II Next Volume>>
Issues in Volume 6 Cover Page and Table of Contents Full Articles
Effect of Water Temperature on Specific Gravity of North Pacific Giant Octopus
Enteroctopus dofleini Paralarvae
Yoshizumi Nakagawa; Minoru Sano; Susumu Segawa. 2019. Transactions on Science and Technology, 6(2), 135 - 140 Abstract The North Pacific giant octopus Enteroctopus dofleini is distributed in coastal areas of the North Pacific Ocean from western North America to Japan. This species is an important commercial marine organism in northern Japan. This study examined the effect of water temperature on the specific gravity of E. dofleini in the early paralarval stage under rearing conditions. Specific gravity, which serves as an indicator of larval buoyancy, was examined from egg to six days after hatching (dAH) under starved and dark conditions at 5ºC and 10ºC. After hatching, the specific gravities of E. dofleini paralarvae decreased significantly until 2 dAH at 5°C and until 1 dAH at 10°C. After 2 dAH at 5°C and after 1 dAH at 10°C, specific gravity did not fluctuate significantly. Overall, specific gravity values were lower at 5°C than at 10°C. Water temperature during the early paralarval stage could affect the ability of E. dofleini paralarvae to gain buoyant force. View article
The First Report on Basal Stem Rot Disease Causal Pathogen in Asian Agri Group, North Sumatra, Indonesia
Dedek Haryadi; Hadi Hendra; Manjit Singh Sidhu; Tumpal Panjaitan; Khim Phin Chong. 2019. Transactions on Science and Technology, 6(2), 141 - 149 Abstract Basal stem rot (BSR) is the most serious oil palm disease in Asian Agri Group’s estates in North Sumatra, Indonesia. Up to 2017, a total of 30 palms per hectare (22% per hectare) in Asian Agri Group have been killed by the disease caused a serious threat to the oil palm sustainability. Whether, BSR is caused by the well known reported Ganoderma boninense, the causal pathogen of BSR is uncertain as no basic molecular identification of the causal pathogen has ever conducted in Asian Agri Group. The reports on the causal pathogen of this disease in Asian Agri Group were merely based on their morphology and pathogenicity. This paper is the first comprehensive report on the identification of the BSR causal pathogen from Asian Agri Group in North Sumatra. The identifcation was done using morphological characterization and DNA sequence analysis. The result showed that BSR causal pathogen of Asian Agri Group in North Sumatra was identified as G. boninense and closely related to the aggressive strain of G. boninense isolate GB001 with 99% of maximum silimarity based on phylogenetic analysis. View article Review Article
Review on Enhanced Oil Recovery Methods and Techniques in Different Reservoirs Rock Types, Conditions and Its simulation
Chen-Chong Chung; Jidon Janaun; Abdul Karim Mirasa; Abu Zahrim Yaser; Ravindra Pogaku. 2019. Transactions on Science and Technology, 6(2), 150 - 168 Abstract In view of the current vast worldwide oil extraction and production, the reservoirs storage capacities lessening scenario, the imminent fast oil production depletion in foreseeable near future and due to the fact that very rich volume of heavier residual oil still remaining down inside the trapped reservoirs that account for 40-60% in total; endeavors to salvage and increase oil production of abandoned matured oil fields become critical. The high volume of heavier oil deposit is hard or impossible to be extracted by normal methods, they are still scattering in all the abandoned or semi-abandoned matured oil fields around the world. Considering of the uncertainties and escalations of worldwide oil prices in the last thirty years, numerous methods and techniques have been derived to revive matured oil fields production. These remaining residual heavier oil deposits that normal extraction by making use of reservoir pressure, pumping and conventional water injection or simply by water flooding could not handle. Steam injection, thermal combustion, chemical (polymers, surfactants), gas, microbial and other methods have been used to continue to improve the extraction of heavier residual oil. This stage of enhanced oil recovery and production are commonly called tertiary oil production or enhanced oil recovery. Current research literature review paper here is to bring forward the detailed nature or types of reservoir rocks (tight shale, sandstone, carbonate and conglomerate) conditions and methods including simulation to understand the essential part of enhanced oil recovery. View article |