Startegi Peningkatan Prestasi Belajar Siswa SD X di Salatiga Ditinjau dari Motivasi Belajar dan Kedisiplinan

Pendidikan formal dimulai dari tahap sekolah dasar dimana seorang anak mendapatkan semua informasi yang dialami dalam kehidupan sehari-hari. Luas wilayah Indonesia yang sangat luas menjadi salah satu faktor kurangnya kemerataan kualitas, mutu dan sumberdaya yang ada. Kualitas pendiidkan dapat dilihat dari hasil belajar siswa. Salah satu faktor yang mempengaruhi hasil belajar adalah motivasi belajar dan kedisiplinan. Kedua hal tersebut memiliki keterkaitan satu sama lain terhasap hasil belajar. Oleh karena itu, dilakukan sebuah penelitian tentang apa strategi yang dilakukan untuk meningkatkan prestasi belajar siswa SD X di Salatiga ditinjau dari motivasi belajar dan kedisiplinan. Untuk mendapatkan jawaban dari pertanyaan di atas maka dilakukan sebuah penelitian dengan teknik pengumpulan data berupa wawancara dan pengambilan nilai sebagai hasil belajar siswa. Setelah data dianalisis dapat diketahui bahwa data tersebut normal sehingga dilakukan tindak lanjut dengan medan ggunakan uji normalitas data menggunakan metode stepwise. Uji tersebut menghasilkan faktor yang paling mempengaruhi hasil belajar siswa adalah disiplin. Berdasarkan hasil analisis yang dilakukan, maka perlu dilakukan treatment khusus pada disiplin siswa sehingga dapat berpengaruh juga pada hasil belajar

Microbial Enhanced Heavy Oil Recovery by the Aid of Inhabitant Spore-Forming Bacteria: An Insight Review

Crude oil is the major source of energy worldwide being exploited as a source of economy, including Oman. As the price of crude oil increases and crude oil reserves collapse, exploitation of oil resources in mature reservoirs is essential for meeting future energy demands. As conventional recovery methods currently used have become less efficient for the needs, there is a continuous demand of developing a new technology which helps in the upgradation of heavy crude oil. Microbial enhanced oil recovery (MEOR) is an important tertiary oil recovery method which is cost-effective and eco-friendly technology to drive the residual oil trapped in the reservoirs. The potential of microorganisms to degrade heavy crude oil to reduce viscosity is considered to be very effective in MEOR. Earlier studies of MEOR (1950s) were based on three broad areas: injection, dispersion, and propagation of microorganisms in petroleum reservoirs; selective degradation of oil components to improve flow characteristics; and production of metabolites by microorganisms and their effects. Since thermophilic spore-forming bacteria can thrive in very extreme conditions in oil reservoirs, they are the most suitable organisms for the purpose. This paper contains the review of work done with thermophilic spore-forming bacteria by different researchers

Isolation and screening of Bacillus subtilis MJ01 for MEOR application: biosurfactant characterization, production optimization and wetting effect on carbonate surfaces

Abstract The bacterial strain MJ01 was isolated from stock tank water of one of the Iranian south oil field production facilities. The 16S rRNA gene of isolate, MJ01, showed 99% similarity to Bacillus subtilis. The results revealed that biosurfactant produced by this strain was lipopeptide-like surfactin based on FTIR analysis. Critical micelle concentration of produced surfactin in distilled water was 0.06 g/l. Wettability study showed that at zero salinity surfactin can change original oil-wet state to water-wet state, but in seawater salinity it cannot modify the wettability significantly. To utilize this biosurfactant in ex situ MEOR process, economical and reservoir engineering technical parameters were considered to introduce a new optimization strategy using the response surface methodology. Comparing the result of this optimization strategy with the previous optimization research works was shown that significant save in use of nutrients is possible by using this medium. Furthermore, using this method leads to less formation damage due to the incompatibility of injecting fluid and formation brine, and less formation damage due to the bioplugging

Production, Characterization and Application of Bacillus licheniformis W16 Biosurfactant in Enhancing Oil Recovery

The biosurfactant production by Bacillus licheniformis W16 and evaluation of biosurfactant based enhanced oil recovery using core-flood under reservoir conditions were investigated. Previously reported nine different production media were screened for biosurfactant production, and two were further optimized with different carbon sources (glucose, sucrose, starch, cane molasses or date molasses), as well as the strain was screened for biosurfactant production during the growth in different media. The biosurfactant reduced the surface tension and interfacial tension to 24.33+0.57mN m-1 and 2.47+0.32mN m-1 respectively within 72h, at 40 C, and also altered the wettability of a hydrophobic surface by changing the contact angle from 55.67°+1.6° to 19.54°+0.96°. The critical micelle dilution values of 4X were observed. The biosurfactants were characterized by different analytical techniques and identified as lipopeptide, similar to lichenysin-A. The biosurfactant was stable over wide range of extreme environmental conditions. The core flood experiments showed that the biosurfactant was able to enhance the oil recovery by 24-26% over residual oil saturation (Sor). The results highlight the potential application of lipopeptide biosurfactant in wettability alteration and microbial enhanced oil recovery processes

Analysis of Bacterial Diversity in Different Heavy Oil Wells of a Reservoir in South Oman with Alkaline pH

The identification of potential hydrocarbon utilizing bacteria is an essential requirement in microbial enhanced oil recovery (MEOR). Molecular approaches like proteomic and genomic characterization of the isolates are replacing the traditional method of identification with systemic classification. Genotypic profiling of the isolates includes fingerprint or pattern-based technique and sequence-based technique. Understanding community structure and dynamics is essential for studying diversity profiles and is challenging in the case of microbial analysis. The present study aims to understand the bacterial community composition from different heavy oil contaminated soil samples collected from geographically related oil well areas in Oman and to identify spore-forming hydrocarbon utilizing cultivable bacteria. V4 region of 16S rDNA gene was the target for Ion PGM™. A total of 825081 raw sequences were obtained from Ion torrent from all the 10 soil samples. The species richness and evenness were found to be moderate in all the samples with four main phyla, Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria, the most abundant being Firmicutes. Bacillus sp. ubiquitously dominated in all samples followed by Paenibacillus, which was followed by Brevibacillus, Planococcus, and Flavobacterium. Principal Coordinate Analysis (PCoA) and UPGMA dendrogram clustered the 10 soil samples into four main groups. Weighted UniFrac significance test determined that there was significant difference in the communities present in soil samples examined. It can be concluded that the microbial community was different in all the 10 soil samples with Bacillus and Paenibacillus sp. as predominating genus. The 16S rDNA sequencing of cultivable spore-forming bacteria identified the hydrocarbon utilizing bacteria as Bacillus and Paenibacillus sp. and the nucleotide sequences were submitted to NCBI GenBank under accession numbers KP119097–KP119115. Bacillus and Paenibacillus sp., which were relatively abundant in the oil fields, can be recommended to be chosen as candidates for hydrocarbon utilization study

Sophorolipids production by Candida bombicola ATCC 22214 and its potential application in microbial enhanced oil recovery

Biosurfactant production using Candida bombicola ATCC 22214, its characterization and potential applications in enhancing oil recovery was studied at laboratory scale. The seed media and the production media were standardized for optimal growth and biosurfactant production. The production media were tested with different carbon sources: glucose (2%w/v) and, corn oil (10%v/v) added separately or concurrently. The samples were collected at 24h interval up to 120h and checked for growth (OD660), and biosurfactant production (Surface tension and Interfacial tension). The medium with both glucose and corn oil gave better biosurfactant production and reduced both surface tension and interfacial tension to 28.56 + 0.42mN/m and 2.13 + 0.09mN/m, respectively within 72h. The produced biosurfactant was quite stable at 13-15% salinity, pH range of 2-12, and at temperature up to 100°C. It also produced stable emulsions (%E24) with different hydrocarbons (pentane, hexane, heptane, tridecane, tetradecane, hexadecane, 1-methylnaphthalene, 2,2,4,4,6,8-heptamethylnonane, light and heavy crude oil). The produced biosurfactant was extracted using ethyl acetate and characterized as a mixture of sophorolipids. The potential of sophorolipids in enhancing oil recovery was tested using core-flooding experiments, under reservoir conditions, where additional 27.27% of residual oil (Sor) was recovered. This confirmed the potential of sophorolipids for applications in microbial enhanced oil recovery

Dendrogram using maximum likelihood method.

<p>Ln Likelihood = -2263.74583. The isolate, <i>P</i>. <i>ehimensis</i> strain BS1was found to be unique from those sequences retrieved from NCBI GenBank.</p