Direct numerical simulation of gas transfer across the air-water interface driven by buoyant convection

A series of direct numerical simulations of mass transfer across the air-water interface driven by buoyancy-induced convection has been carried out to elucidate the physical mechanisms that play a role in the transfer of heat and atmospheric gases. The buoyant instability is caused by the presence of a thin layer of cold water situated on top of a body of warm water. In time, heat and atmospheric gases diff use into the uppermost part of the thermal boundary layer and are subsequently transported down into the bulk by falling sheets and plumes of cold water. Using a specifically-designed numerical code for the discretization of scalar convection and diffusion, it was possible to accurately resolve this buoyant instability induced transport of atmospheric gases into the bulk at a realistic Prandtl number (Pr = 6) and Schmidt numbers ranging from Sc = 20 to Sc = 500. The simulations presented here provided a detailed insight into instantaneous gas transfer processes. The falling plumes with highly gas-saturated fluid in their core were found to penetrate deep inside the bulk. With an initial temperature difference between the water surface and the bulk of slightly above 2 K peaks in the instantaneous heat flux in excess of 1600 W/m² were observed, proving the potential effectiveness of buoyant convective heat and gas transfer. Furthermore, the validity of the scaling law for the ratio of gas and heat transfer velocities K_L / H_L ∼ (Pr/Sc)^0:5 for the entire range of Schmidt numbers considered was confirmed. A good time-accurate approximation of K_L was found using surface information such as velocity fluctuations and convection cell size or surface divergence. A reasonable time-accuracy for the K_L estimation was obtained using the horizontal integral length scale and the root-mean-square of the horizontal velocity fluctuations in the upper part of the bulk.The German Research Foundation (DFG grant UH242/6-1). Additional funding by the Helmholtz Water Network

IMPACTS OF SOCIAL MEDIA TOWARDS LANGUAGE SHIFT AMONG UNIVERSITY STUDENTS

Social Media Applications are inevitable in today’s people’s lives, especially for university students who cannot be separated with their gadgets. It is undeniable that the use of social media changes the way people communicate with each other, from oral communication to written text communication. This study tries to find out whether social media usage influences the language used in communication, especially among university students. Another question addressed by this study is whether students with ethnic language background still maintain their ethnic languages when communicating using social media. Forty (40) English Department students of Bina Nusantara University were conveniently selected as participants for this study. They were given a questionnaire consisting of two parts, the first relating to the language use in daily communication and the second relating to the language use in social media communication. Research revealed that social media affect the way students communicate to each other. There is a shift in the use of language from ethnic language to Indonesian. Yet, a shift from Indonesian to English will not happen in a short time

Konten Pengungkapan Perasaan Pelaku Friend With Benefit (FWB) di Media Sosial (Analisis isi akun Instagram @fwb.bercerita)

Instagram @fwb.bercerita is an account that accommodates actors in Friends with Benefits (FWB) relationships to share stories, experiences and feelings anonymously. Through Instagram feed posts, FWB perpetrators reveal various aspects of their relationship, including the feelings of happiness, sadness, disappointment, neutrality that FWB perpetrators feel when they are in a FWB relationship. This research is to describe the extent of the content of messages expressing the feelings of FWB perpetrators in posts on the Instagram account @fwb.bercerita. The concept used in this research is that communication in friendships contains variations in self-disclosure (Devito, 2007). Through social media, communication is not only for finding friends or just posting pictures for entertainment, but can also be a means for sharing information and can even be a medium for expressing feelings for someone or a cathartic medium for channeling their emotions through healthy and non-harmful methods that can reduce stimulation. emotional and a tendency to carry out aggressive attacks against other people (Wahyuningsih, 2017). This research uses a content analysis method with a quantitative approach and descriptive data type. The object of this research is the Instagram feed of the @fwb.bercerita account which is analyzed from the three category structures used, namely the level of expression of feelings, the motive of the FWB perpetrator and the target of the FWB perpetrator. Data collection uses documentation techniques. The results of the research show that of the 10 posts that have been studied, there is a level of expression of feelings referring to feelings of pleasure that is most often felt by FWB perpetrators. Then, the motive for most FWB perpetrators is mutual desire and the targets of most FWB perpetrators are college students. It can be concluded that FWB perpetrators can use the Instagram account @fwb.bercerita as a cathartic medium that accommodates perpetrators in expressing their feelings

Direct numerical simulation of turbulent scalar transport across a flat surface

To elucidate the physical mechanisms that play a role in the interfacial transfer of atmospheric gases into water, a series of direct numerical simulations of mass transfer across the air-water interface driven by isotropic turbulence diffusing from below has been carried out for various turbulent Reynolds numbers ( RT=84,195,507). To allow a direct (unbiased) comparison of the instantaneous effects of scalar diffusivity, in each of the DNS up to six scalar advection-diffusion equations with different Schmidt numbers were solved simultaneously. As far as the authors are aware this is the first simulation that is capable to accurately resolve the realistic Schmidt number, Sc=500, that is typical for the transport of atmospheric gases such as oxygen in water. For the range of turbulent Reynolds numbers and Schmidt numbers considered, the normalized transfer velocity KL was found to scale with RT-1/2 and Sc-1/2, which indicates that the largest eddies present in the isotropic turbulent flow introduced at the bottom of the computational domain tend to determine the mass transfer. The KL results were also found to be in good agreement with the surface divergence model of McCready, Vassiliadou & Hanratty (AIChE J., vol. 32, 1986, pp. 1108-1115) when using a constant of proportionality of 0.525. Although close to the surface large eddies are responsible for the bulk of the gas transfer, it was also observed that for higher $R-T$ the influence of smaller eddies becomes more important. © 2014 Cambridge University Press

The Translation of English Passive Voice Into Indonesian

English and Indonesian have different grammatical patterns and cultural values. That is why, many problems that students studying translation subject have to face. One of them is how to translate English Passive Voice into Indonesian. That is the reason the writer aims to do the research. The research is to describe the translation of English passive voice into Indonesian by analyzing two novels, which are Kristan Higgins' Waiting on You and its translation Nina Andiana's Penantian Terpanjang. This research uses qualitative method. The writer collected, identified, the data concerning with the translation of English passive voice. The results of the research shows that there are two categories of translating English passive voice into Indonesian, namely English passive voice can be translated both into Indonesian passive voice and English passive voice can be translated into Indonesian active voice. English passive voice is translated into Indonesian passive voice by using prefixes di- and ter-, meanwhile English passive voice is translated into Indonesian active voice by using prefixes me-, men-, and ber-. From forty one data which are identified there are 32 data (78.04%) of English passive voices translated into Indonesian passive voices and 9 data (21.96%) of English passive voices translated into Indonesian active voices

PENGARUH MOTIVASI BELAJAR DAN EFIKASI DIRI TERHADAP HASIL BELAJAR MATA PELAJARAN KEARSIPAN PADA SISWA ADMINISTRASI PERKANTORAN DI SMK SEJAHTERA JAKARTA

ABSTRACT HERLINA. 8105132199. The Influence of Learning Motivation and Self Efficacy to Learning Result Subject on Office Administration Student at SMK Sejahtera Jakarta. Skripsi. Jakarta: Economic Education Studies Program, Faculty of Economics, Jakarta State University, 2017. This study aims to determine whether there is influence of learning motivation and self efficacy to learning result subject on office administration student at SMK Sejahtera Jakarta. This research was conducted for three months from March to May 2017. The research method used is survey method and documentation method with correlational approach. The sample used in this research is 105 students by using proportional random sampling technique. Y variable data (Learning result) is secondary data obtained from data of second and third daily test result. While the data variable X1 (Learning Motivation) and variable data X2 (Self Efficacy) instrument used is a questionnaire model using the Likert scale model. Prior to use, validity and reliability tests were performed on the research instrument. Data analysis technique using SPSS program version 21.0 begins by searching for trial. Test, multiple linear regression test, hypothesis test. Based on the results of data analysis can be known partially between the motivation of learning with learning outcomes. Can be seen from the results of data analysis showing thitung value of 3.880> ttable of 1.659. Partial self-efficacy partially to the learning outcomes, this is seen from the results of data analysis showing the value of t countitung 6.622> ttable value. Motivation learning and self efficacy simultaneously for learning outcomes, this is seen from the results of data analysis showing the value of Fhitung 37.434> Ftabel value. Regression equation obtained is Y = 40,044 + 0,167X1 + 0,291X2. Based on the review of R2 value of 0.423, which means learning motivation (X1) and self efficacy (X2) results on learning outcomes (Y) of 42.3%. This study is a positive and significant between learning motivation and self efficacy on the results of learning archival subjects in students at SMK Sejahtera Jakarta. Therefore, it is expected that the school can improve the motivation to learn to overcome external motivation, especially to create a conducive learning environment for students and also to increase selfefficacy of students, especially in working on difficult tasks / questions given so that students can get the results of learning as expected. Keywords: Self Efficacy, Learning Results, Learning Motivatio

Deproteinase Effect of Hydrocolloid Flour Made of “Gembili Tuber” (Dioscorea esculenta L.) on Chemical and Technical Functional Properties

Hydrocolloid flour extracted of gembili tuber studied in this research to know the chemical and technical functional properties. Hydrocolloid flour extracted directly with distilled water (HFC) and hydrocolloid flour which has reduced protein (deproteinase) by hydrolysis with 0.05% protease of Aspergillus oryzae (HFD). Compared to the chemical properties and technical functional properties covering proximate test, total sugars, solubility, power and emulsion stability, power and  foaming stability, water holding capacity (WHC), oil holding capacity (OHC), viscosity to changes in temperature and viscosity to changes in pH. The results showed that different test t-test (α = 0.05) moisture content, ash content and fat content between HFC and HFD not significant, while the levels of protein and carbohydrates are significant. Deproteinase the process of hydrocolloid  flour made of  gembili tuber with 0.05% protease enzyme use in the extraction able to lower protein content by 49.57% and increase of carbohydrates by 11.39%.   In addition, the process deproteinase effect the technical functional properties of hydrocolloid flour increase solubility, emulsion stability, foam stability, WHC and OHC. Increasing in the temperature by  10-90 °C lower the viscosity by 70%  (56.33 ± 0.19mp to 17.05 ± 0.03 mp) of HFC and  73% (26.16 ± 1.28 mp to 7 , 08 ± 0.79 mp) of HFD. The highest viscosity hydrocolloids flour (HFC and HFD) contained at pH 7 and decrease with acidic or alkaline conditions

ANALISIS ASPEK LEKSIKAL DAN ASPEK KONTEKS DALAM LAGU OEMAR BAKRI KARYA IWAN FALS

Penelitian ini tidak tergantung pada tempat tertentu karena menggunakan tinjauan pustaka. Hal yang akan dibicarakan dalam analisis ini yaitu aspek leksikal dan aspek konteks. Tujuan dari penelitian ini adalah untuk mengidentifikasi aspek leksikal dan aspek konteks dalam lagu Oemar Bakri Iwan Fals. Metode yang digunakan adalah metode deskriptif. Semua fenomena dalam lagu Oemar Bakri karya Iwan Fals akan disajikan dan dijelaskan secara rinci. Berdasarkan hasil analisis, ditemukan bahwa lagu Oemar Bakri karya Iwan Fals tidak ditemukan kesepadanan (ekuivalensi). Konteks kultural yang terkandung dalam lagu Oemar Bakri karya Iwan fals bahwa kurangnya perhatian pemerintah terhadap kesejahteraan guru mengakibatkan timbulnya budaya bolos kerja dikalangan guru.Kata kunci: aspek leksikal dan kontek