Rocks and sand mines have important benefits for life. With the many benefits of rocks, it is a pity if Indonesia has a lot of raw material reserves waste it. Examples of the benefits of rocks that can be converted in...
Rocks and sand mines have important benefits for life. With the many benefits of rocks, it is a pity if Indonesia has a lot of raw material reserves waste it. Examples of the benefits of rocks that can be converted into silica potassium fertilizer by reacting with potassium hydroxide. Examples of rocks that can be taken trass rock. The procedure for making silica potassium is by reacting 100 mesh trass rock with KOH and K2CO3 reagents whose composition is arranged by weight ratio, where the base of the trass rock is 100 gr. The process is carried out at a temperature of 1.250 °C with a reaction time of 1 hour. The results obtained are the best silica potassium fertilizer for K2CO3 reagent which is 500gr: 74gr with SiO2 content: 26.8% and K2O content: 27.3%, with water solubility 24.02%, while for silica potassium fertilizer product from The best trass rock for KOH reagent is with a mol ratio of 400 gr : 60 gr with SiO2 content : 23.6% and K2O content: 22.2%, with 25.65% water solubility. The pore size of silica potassium fertilizer product of this trass rock, the range 350 – 1000 nm.
This study aims to: 1) describe the mechanism of the level 2 IQF (the Indonesian Qualifications Framework) descriptor development for electrical engineering, and 2) formulate a set of detailed-level-2 descriptors for ...
This study aims to: 1) describe the mechanism of the level 2 IQF (the Indonesian Qualifications Framework) descriptor development for electrical engineering, and 2) formulate a set of detailed-level-2 descriptors for electrical engineering. The method used to develop the descriptors is brainstorming between the researcher and several experts from both academicians and practitioners. Meanwhile, the method to formulate the IQF descriptors for electrical engineering is literature review referring to The Indonesian National Work Competency Standard (SKKNI) and focus group discussion involving experts from academicians, Professional Certification Institute Gema PDKB, the Association of Indonesian Electrical Works (APEI), Consortium for Electrical Installation Safety (KONSUIL), and industry practitioners such as PT. LEN Bandung, PT. Bukaka Teknik Utama, PT. Schneider Electric Indonesia, and PT. Smart Energi Semesta. The descriptors are in the form of the guttman scale questionnaire. The questionnaire was then tested on limited-scale respondents. The KR 20 method was employed to examine the reliability and resulted in r11 = 0.9; thus, the guttman scale questionnaire was considered 'very reliable'. The respondents consisted of 8 academicians, 8 electrical engineering teachers at vocational high schools, and 8 industrial practitioners. The collected data were then analyzed descriptively. This study resulted in a set of level 2 IQF descriptors which were designed according to the taxonomy of electricity system, namely electric power transmission system descriptors, electric power distribution system descriptors, and electric power utilization descriptors. In regard to electric power transmission system, 103 out of 154 (67%) descriptors were approved by more than 80% of respondents; for electric power distribution system, 83 descriptors (75%) were approved by more than 80% of respondents; and for electric power utilization system, 61 descriptors (94%) were approved by more tha
At the Unit Laka Lantas Polres Lhokseumawe determining accident-prone areas on roads in Lhokseumawe still using manual systems. Determination of accident-prone areas are less effective because the police Unit Laka Lan...
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The delay in construction projects undertaken by contractors is impeding the economic growth of a region. Medan city which is one of the big cities in Indonesia is suffering from it. This study aims to identify the do...
The delay in construction projects undertaken by contractors is impeding the economic growth of a region. Medan city which is one of the big cities in Indonesia is suffering from it. This study aims to identify the dominant factors causing delays in construction projects conducted by private contractors. The interview method with questionnaires is used to involve 20 contractors, 10 consultants, and 10 owner representatives in the study. From the 45 identified factors causing delays, the highest ranking is the change of work demand by the project owners with 71.84% importance index.
This research addresses the impact of the building integrated photovoltaic (BIPV) solutions on the performance of a residential building with the area of 2247 m 2 at different regions of Coastal Anatolia. Three citie...
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This research addresses the impact of the building integrated photovoltaic (BIPV) solutions on the performance of a residential building with the area of 2247 m 2 at different regions of Coastal Anatolia. Three cities are chosen with respect to their solar heat gain as the lowest, highest and average. Hourly performances are calculated using the DOE software of Energyplus and installed peak PV power calculated as 84.2 kW. Our preliminary results showed that the annual heating and cooling energy consumption for the three locations vary between 1.44 kWh/m 2 -9.12 kWh/m 2 and 22.2 kWh/m 2 -56.9 kWh/m 2 , respectively. The cooling demand is much higher than the heating demand for these coastal locations of Anatolia (as expected). The maximum use of the three cities is 56.9 kWh/m 2 and according to results this load can be easily supplied by an 84.2 kWp PV. As these are preliminary results they can be treated within margins of ± 20 kW depending on the orientation of the building facades and the type of the solar cells.
Design of fishing boat for Pelabuhanratu fisherman as one of effort to increase production of capture fisheries. The fishing boat should be proper for the characteristic of its service area, as; capacity of fishing bo...
Design of fishing boat for Pelabuhanratu fisherman as one of effort to increase production of capture fisheries. The fishing boat should be proper for the characteristic of its service area, as; capacity of fishing boat up to 60 GT, the fishing boat has minimum 6 fish holds and location of fish hold in the middle body, the fishing boat hull has the bilge keel plate, and the material of hull fishing boat to be made of wooden, steel, aluminium, or fiberglass. Main dimesion of fishing boat is Length Over All = 25.436 m, Breadth = 4.55 m, Draft = 1.6 m, Speed = 12.5 knots. The research had been known every thing that will be supporting the production of capture fisheries like ; amount of fish production = 25.030 ton per day, the fishing port capacity approximately 268.957GT per day, the area of fishing port < 30 hectares, the zone of fish processing industry had not completed, therefore all data research result less than standard of Oceanic Fising Port. So Pelabuhanratu National Fishing Port can not be changed to Oceanic Fishing Port.
Water is a very important resource for life on earth. Nowadays, water scarcity is a big issue around the world. Especially people who live in wetland areas, river is an important water source for their daily life. Unf...
Water is a very important resource for life on earth. Nowadays, water scarcity is a big issue around the world. Especially people who live in wetland areas, river is an important water source for their daily life. Unfortunately, the water becomes salty due to seawater intrusion into the river. The objective of this work is to apply desalination via pervaporation process of wetland saline water using pure silica membranes employ TEOS (tetraethyl orthosilicate) as a precursor. A two-step acid-base catalysed method has been applied to produce silica sols. The pure silica membranes were calcined under RTP (Rapid Thermal Process) method at 600°C for 1 hour. The various temperatures (20, 40 & 60 °C have been set in pervaporation set up in order to investigate the performance of silica membranes. It was found that at high temperature, silica membranes start to densify and give the lowest rejection compare to lower temperatures (84.9 %). In contrary, there was 100% of water flux increases when the feed temperature increases (from 0.61 to 1.19 kg m-2 h-1)
Root canal treatment failures generally caused by microorganisms that have ability to invade dentinal tubules. Chlorhexidine is widely known to effectively eradicate broad spectrum bacteria that infected dentinal tubu...
Root canal treatment failures generally caused by microorganisms that have ability to invade dentinal tubules. Chlorhexidine is widely known to effectively eradicate broad spectrum bacteria that infected dentinal tubules. The delivery of chlorhexidine to the infected site of root canal still becomes an issue. In order to increase the stability and to regulate the release of chlorhexidine, encapsulation of chlorhexidine digluconate was conducted by employing nanocellulose and alginate nanocomposites. Nanocellulose was prepared from palm kernel cake using acid hydrolysis method. Transmission electron microscopy images showed the formation of whisker and fiber nanocellulose with the average diameter of 20 nm. Resulting nanocellulose was combined with alginate in the presence of Ca2+ crosslinker. Scanning electron microscopy images displayed sphere and oval morphologies of microcapsules with diameter of 500 nm. The microcapsules were further loaded with chlorhexidine digluconate 2% (w/v). In vitro drug release properties were evaluated in PBS at pH 7.4 (normal tooth environment) and at pH 5.5 (infected tooth environment). The UV-VIS results showed that chlorhexidine digluconate has higher release rate at pH 5.5 than at pH 7.4, suggesting that the microcapsule is a good candidate for the delivery of chlorhexidine digluconate to the infected root canal tooth environment.
In this study, silica thin film pH=6 (precursor TEOS:tetraethyl ortosilicate) developed from sol gel process and deposited (2 layers) directly onto alumina substrate(tubular support with 100 nm pore size) without depo...
In this study, silica thin film pH=6 (precursor TEOS:tetraethyl ortosilicate) developed from sol gel process and deposited (2 layers) directly onto alumina substrate(tubular support with 100 nm pore size) without depositing interlayer (interlayer-free).Then, the desalination process via pervaporation was applied to test the membranesperformanceusing artificial saline water and wetland saline water. Results show the decrease of water flux (1.9 to 1.43 kg m-2 h-1) and salt rejection(97 to 95%) when using artificial salty water (0-7.5 wt%) and the long-term stability of silica membrane was stable at 1.7 kg m-2 h-1 for over 100 hours when using wetland saline water as a feed.
High calcium fly ash geopolymer composite was prepared by incorporating short carbon fiber in the geopolymer matrix. The carbon fiber (CF) content was varied from 0 to 1%, the liquid to ash ratio was controlled at 0.5...
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High calcium fly ash geopolymer composite was prepared by incorporating short carbon fiber in the geopolymer matrix. The carbon fiber (CF) content was varied from 0 to 1%, the liquid to ash ratio was controlled at 0.5. The workability, mechanical and electrical properties of the geopolymer composites were examined. The result showed that the incorporation of 0.5%CF and above resulted in the ductile failure of specimen. The increasing CF content also resulted in decreasing workability and mechanical strength. The electrical resistivity was also reduced and was more stable to the curing age and temperature. The cyclic voltammetry (CV) curve of 60°C curing provided less peaks than that of 25°C.
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