The desert green algae Chlorella ohadii thrives at excessive high light intensities by exceptionally enhancing the mechanisms that protect photosynthesis from photoinhibition

Although light is the driving force of photosynthesis, excessive light can be harmful. One of the main processes that limits photosynthesis is photoinhibition (PI), the process of light-induced photo-damage. When the absorbed light exceeds the amount that is dissipated by photosynthetic electron flow and other processes, damaging radicals are formed that mostly inactivate photosystem II (PSII). Damaged PSII must be replaced by a newly repaired complex in order to preserve full photosynthetic activity. Chlorella ohadii is a green micro-alga, isolated from biological soil crusts in the desert that thrive under extreme high light and is highly resistant to PI. Therefore, C. ohadii is an ideal candidate for study the molecular protection mechanisms from PI. To charac-terize these protection mechanisms in C. ohadii, we compared thylakoids of cells that were grown under low light versus extreme high light intensities. C. ohadii were found to employ all three known PI protection mechanisms: i) performance of massive reduction of the PSII antenna size; ii) accumulate protective carotenoids; and iii) possess a very fast repair cycle of photo-damaged reaction center proteins. This work elucidated the molecular mechanisms of photoinhibition resistance in one of the most light-tolerant photosynthetic organisms and shows how photoinhibition protection mechanisms evolved to marginal conditions enabling photosynthesis-dependent life in severe habitats.One Sentence HighlightAnalysis of the photosynthetic properties of a desert algae that thrives at extreme high light in-tensities reveals how protection from photoinhibition is achieved by a remarkable enhancement of three protection mechanisms.

Karakteristik Marshall pada Campuran Aspal Dingin dengan Asbuton Akibat Dari Penggunaan Aditif Wetfix-BE

West Nusa Tenggara Province consists of two main islands namely Lombok and Sumbawa. Regency Roads on Lombok Island, especially rural roads, has been severely damaged due to lack of routine maintenance. The types of damage that occur are cracks, small holes, and even large pools that endanger road users. This study aims to obtain a mixture of new materials in order to obtain an easy and fast repair method without reducing the quality during its intended life. In the meantime, repairing with CAD (cold asphalt mixture) requires curing time of 3x24 hours to achieve standard material quality with Marshall Characteristics according to the 2010 Bina Marga Specifications. This study combines CAD using BP (rejuvenating agent) and Wetfix-BE additive to get optimal results without curing process. The BP used is asphalt mixture, kerosene, and bunker oil stirred in a mixing machine into one unit. The results showed the optimum concentration of this mixture was 0.3% wet-be additive, 4.50% BP in CAD with asbuton proportion of 25%. In the fatigue test with a cyclic loading of 100 kPa, the pavement mixture is able to resist a fully loaded truck of 7731 times. In conclusion, this mixture combination is able to speed up the asphalt binding time by making briquettes according to the 2018 Highways Specifications without going through the long curing process.

Study of Tube And Tank Specimens Repaired Using a Carbon Fibre Reinforced Epoxy

Merchant and passenger ships operate in harsh environments where they constantly suffer from corrosion and crack problems. The traditional cutting and welding of the steel parts most often requires redirection of a vessel to a shipyard what results in substantial vessel out-of-service time. In such situations, a ship operator seeks an efficient and fast repair solution to minimise ship delays. Following advancements in research and application of composite materials, an opportunity to implement composite patches made of carbon fibres and epoxy resin has emerged in the shipping industry as one of the cost and time efficient repair solutions. Although, the resin hardens and bonds the fibres strongly to the damaged surface, classification societies still consider this repair as a temporary solution and accept it conditionally, meaning with the frequent obligatory inspections. This is because there hasn’t been enough practical evidence yet to recognise the composite patching as the permanent repair solution. In order to further investigate the efficiency of the composite patching, this paper presents the finite element (FE) strength investigation of 17 patches applied to tube and tank specimens under water pressure. The future work will consider a validation of the obtained FE results by means of pressure testing during the course of the qualification process.

A review: Fast Repair Technology of Cement concrete pavement

Cement concrete pavement Road always damaged under the pressure of traffic, so fast repair technology of cement concrete pavement was an urgent need to be studied. The author introduced the new rapid repair technology of cement concrete pavement from the concrete materials, mixture design, and construction equipment.

AUTOMATION SYSTEM FOR IMPROVING THE EFFICIENCY OF PRODUCTION FOR GAS LIFT WELLS

The paper deals with the problem of automation of one of the methods of mechanized production - gas lift wells operation. The main advantages of this method of operation are its low cost, work with high gas content, simplicity of the design of deep equipment, fast repair in cattle, minimal power consumption and control and automation of the extraction process at the expense of the Gazlift process control system. This complex is designed to control the process of gas-lift oil production by remote control, as well as the collection and processing of information from primary transducers, the ability to control actuators that provide optimal performance of wells, as well as the ability to quickly change the mode of operation of wells.

Fault Identification and Location for Distribution Network with Distributed Generations

Power distribution networks with distributed generations may experience faults. It is essential to promptly locate the fault for fast repair and restoration. This paper presents a novel method for identifying the faulted section and accurate location of faults that occur on power distribution grid. Appropriate matrices are set up to represent meter locations on the grid and the topology of the grid. The voltage and current measurements obtained are utilized to decide the fault sections. Then fault location is determined by solving equations that link measurements and fault locations through bus impedance matrix. The method is applicable to both single and simultaneous, multiple faults that may occur on unbalanced, meshed distribution networks with distributed generations.