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"This book summarizes the gathering of information on and the growing understanding of M33 from the 1920s, when Hubble first determined its true nature, to the 21st century, when the Hubble Telescope probed deeply into its many secrets. With its regular symmetrical spiral structure, and its being not tilted too much and near enough to allow detailed studies of its stars, M33 is well-suited for the study of a typical spiral galaxy. In this work, Paul Hodge places current research on M33 (and similar galaxies) in both historical and global perspectives."

"The andromeda galaxy and the rise of modern astronomy examines the astronomical studies of Andromeda and its importance to our developing knowledge of the universe. The book discusses how M31 was described both by the Ancients, but more importantly, by astronomers from the nineteenth century to the present. While at the start of the twentieth century the universe was thought of as a finite cosmos dominated by the Milky Way, the study of Andromeda galaxy shattered that image, leading ultimately to the conception of an infinite universe of countless galaxies and vast distances. Even today, M31 is a major focal point for new astronomical discoveries, and it also remains one of the most popular (and rewarding) celestial objects for amateur astronomers to observe and study. This book reveals the little-known history of M31 and the scientists who study it."

"Indonesia khususnya Jawa Timur mengalami bencana luapan lumpur yang disebabkan oleh eksplorasi minyak dan gas. Bencana ini dikenal dengan sebutan lumpur Sidoarjo (lusi) atau lumpur Lapindo. Lumpur pada dasarnya adalah campuran antara partikel padat dan air yang membentuk suatu suspensi. Pada saat lumpur diangkut dengan menggunakan pipa, dan jika kecepatan alir tidak cukup tinggi maka lumpur tidak akan bertahan membentuk suspensi sehingga terjadi pengendapan. Dalam pipa spiral dengan rasio pitch perdiameter tertentu, terjadi aliran puntir sehingga mampu mempertahankan kecepatan aliran.Tujuan penelitian ini adalah untuk mengetahui karakteristik aliran lumpur dalam pipa spiral. Tegangan geser dan regangan geser dihitung dengan mengukur perbedaan tekanan (pressure drop) dan laju aliran volumetrik dalam pipa. Nilai indeks power law sekitar 0,93-1,0 untuk konsentrasi berat (Cw) lumpur sebesar 45%, 30% dan 20%. Diameter partikel adalah 0,95 mm dan massa jenis adalah 2,19 x 103 (kg/m3). Hubungan viskositas sesaat dengan regangan geser menunjukkan hubungan yang tidak konstan. Koefisien gesek di dalam pipa spiral dengan rasio pitch per diameter (P/Di) = 6,7 lebih rendah dari pipa bulat dan pipa spiral dengan P/Di = 3,9 ; 4,3 dan 7,0. Hal ini menunjukkan bahwa pipa spiral menyebabkan penurunan hambatan (drag reduction) aliran lumpur. Nilai drag reduction sekitar 28% untuk Cw = 30% pada Reynolds generalis, Re? = 3,2 x 104 . Analisis model matematika dari nilai koefisien gesek aliran lumpur pada pipa spiral sebagai fungsi dari kepadatan lumpur, rasio pitch/diameter, dan bilangan Reynolds generalis dapat ditunjukkan.

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Indonesia particularly East Java has been suffering from eruption of gas and mud slurry, caused by oil and gas exploration. Everyone calls this disaster as Sidoarjo mud or Lapindo mud. Mud slurry is essentially a mixture of a carrying fluid and solid particles held in suspension. When the mud slurry flow speed is not sufficiently high the particles will not be maintained in suspension. In spiral pipe twisted with a constant pitch in relation to the diameter a swirling flow occurs when fluids flow in the pipe.The aim of this study is to examine characteristics of the hydraulic transport of mud slurry flowing in the spiral pipe with three-shaps groove pipe walls. Measurements of pressure drop was carried out for tap water and mud slurry solution in circular pipes and spiral pipes by means of a manometer. The shear stress and the shear strain are calculated by measuring the pressure drop and the volumetric flow rate in circular pipe, respectively. The power law index were about 0.93 ? 1.0 for mud slurry solution of 45%, 30% and 20% of weight concentrations. The diameter of particles was ± 0.95 mm and the density was 2.19 x 103 (kg/m3). The apparent viscosity of mud slurry solution is not constant to the shear rate but the relationship is approximated by model of power law. The friction factor of mud slurries in a spiral pipe with ratio pitch per diameter 6.7 is lower than circular pipe and spiral pipe with P/Di= 3.9, 4.3 and 7.0. It was shown that the spiral pipe caused drag reduction in flowing of mud slurries. The drag reduction ratio of spiral pipe was about 28% for Cw=30% at Reynolods generalis, Re?=3,2 x 104. Analysis of mathematical models of the value of the coefficient of friction on the mud flow as a function of weight concentration, the ratio of pitch per diameter, and generalist Reynolds number can be shown."

"Dalam transportasi fluida menggunakan pipa, koefisien gesek merupakan besaran yang sangat penting karena berkaitan dengan konsumsi energi. Pipa berpenampang seperti pipa spiral digunakan untuk pencampuran fluida kerja. Tujuan dari penelitian ini untuk menganalisis perubahan nilai koefisien gesek pada sejumlah pipa dengan penambahan nano partikel Al2O3 yang dicampurkan ke dalam air sebagai fluida dasar. Pipa yang digunakan adalah pipa bundar (D=3 mm) dan pipa spiral (Diameter hidrolis = 6 mm) . Variasi konsentrasi yang dipakai adalah 100 ppm, 200 ppm, dan 300 ppm. Variasi lamanya waktu pencampuran adalah 30, 60, dan 90 menit. Hasil dari penilitian ini adalah tidak ditemukannya pengurangan koefisien gesek di rentang nilai Reynolds 5000-10000.

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On fluid transportation using pipes, friction factor is an important thing because it influences energy consumption. Special pipes, like spiral pipe, are used for mixing the fluids. The purpose of this research is to analyze friction factor?s change caused by adding Al2O3 nano particles to water as base fluid. This research used two kinds of pipe, circular pipe (inner diameter=3 mm) and spiral pipe (diameter of hydrolic = 6 mm). The variation of concentration are 100 pm, 200 ppm, and 300 ppm. The variations of mixing time are 30, 60, and 90 minutes. The results of this research is there is no drag reduction on any pipe on Reynolds number between 5000 and 10000."

"Berdasarkan paper Gupta [1] telah dihitung massa dari 12 gugusan galaksi (dengan data Chandra X-ray) menggunakan persamaan Tolman-Oppenheimer-Volkov (TOV) dari kesetimbangan hidrostatik dan persamaan keadaan gas ideal. Rumus secara penghitungan analitik untuk kerapatan gas dan temperatur untuk gugusan ini, sebelumnya telah diturunkan oleh Vikhlinin, dkk [2]. Lalu digunakan untuk menentukan massa klaster/gugusan. Kemudian massa berbasis persamaan TOV ini diselisihkan dengan massa dari persamaan hidrostatika Newton lalu dibandingkan dengan penghitungan yang diperoleh menggunakan persamaan hidrostatika Newton (ΔM/M). Ditemukan hasil bahwa hanya sedikit perbedaan antara dua massa tersebut, perbedaannya sebesar suku 10^(-5), sehingga efek relativistik dapat diabaikan. Disini penulis akan menggunakan pendekatan yang lain untuk menghitung perbandingan massa nya (ΔM/M), yaitu dengan prinsip ketidakpastian diperumum/GUP, serta teori gravitasi termodifikasi EiBI (Eddington-inspired Born Infeld) dan BHG (Beyond Horndeski Gravity), tetapi dalam tinjauan non-relativistik dan kesetimbangan hidrostatik. Parameter bebas dari GUP dan masing-masing teori gravitasi termodifikasi ini kemudian dikaitkan dengan data-data gugusan galaksinya pada literatur, nantinya dapat diperoleh koreksi massanya serta persentase perbandingan massanya. Berdasarkan hasil yang diperoleh dalam karya ilmiah tesis ini dengan mudah dapat dijelaskan impak dari GUP dan teori gravitasi termodifikasi EiBI dan BHG pada objek di gugus galaksi. Hasil yang diperoleh adalah bahwa pendekatan GUP/Entropic Force (dengan parameter β_0 = -1,656 × 10^43 [3]) tidak terlalu berdampak pada massa objek galaksi, karena nilai koreksi massa yang diperoleh dari penghitungan GUP orde nya sangat kecil yaitu 10^(-67). Agar berdampak, paramaternya divariasikan, didapat β_0 = -1,656 × 10^110 ≈ -10^110. Dampaknya yaitu massa globular (galaksi) semakin besar. Pada teori gravitasi EiBI (dengan parameter κ = 5 m^2 [4]) juga tidak terlalu memberikan dampak pada massa objek galaksi disebabkan hasil orde koreksi massa dengan EiBI juga kecil yaitu 10^(-46). Lalu agar memiliki dampak, maka parameter κ divariasikan dan diperoleh nilai rentangnya yaitu 5 × 10^38 ≤ κ ≤ 5 × 10^40 m^2. Dampaknya adalah massa globular semakin kecil. Namun untuk teori gravitasi BHG, langsung memberikan dampak terhadap massa galaksi dengan tanpa memvariasikan parameternya, dengan parameter Υ = -0,1655 [5]. Dampak yang terjadi adalah memperbesar keseluruhan massa galaksi klaster. Kemudian dampak dari teori BHG ini adalah memperkecil nilai korelasi-R (regresi linear kurva), yang diperoleh dengan fitting ratio dari persamaan M = (M_dyn^c)/(M_bar^c ) [6] yang awalnya diperoleh M = 0,84 ± 0,04 [6] menjadi M = 0,316 ± 0,00044, maka dapat disimpulkan bahwa akibat perubahan massa pada teori BHG dapat memperkecil nilai korelasi-R nya.

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Based on Gupta’s paper [1] has been calculated the mass of 12 galaxy clusters (with Chandra X-ray data) using the Tolman-Oppenheimer-Volkov (TOV) equation of hydrostatic equilibrium and the equation of state for an ideal gas. The analytically calculated formulas for gas density and temperature for these clusters have previously been derived by Vikhlinin et al. [2] Then, it is used to determine the mass of the clusters/galaxy groups. Then the mass based on the TOV equation is subtracted from the mass from Newton’s hydrostatic equation and then compared with the calculations obtained using Newton’s hydrostatic equation (ΔM/M). It was found that there was only a slight difference between the two masses; the difference was in terms of 10^(-5), so the relativistic effect could be neglected. Here we calculate the mass ratio (ΔM/M) by considering the effect of the Generalized Uncertainty Principle (GUP), as well as the modified EiBI (Eddington-inspired Born Infeld) and BHG theories of gravity (Beyond Horndeski Gravity), but within non-relativistic hydrostatic equilibrium. The constraint parameters of GUP and each modified theory of gravity are then linked to the data on their galaxy clusters in the literature, so that later mass corrections can be obtained as well as the percentage ratio of their masses. So that from the results, we can easily explain the impact of the GUP and the modified EiBI and BHG theories of gravity on objects in galaxy clusters. The results obtained are that the GUP/Entropic Force approach (with parameter β_0 = -1,656 × 10 ^43 [3]) does not have much impact on the mass of the galaxy object, because the mass correction value obtained from the calculation of the order GUP is minimal, namely 10^(-67). In order to have an impact, the parameters are varied, we get β_0 = -1,656 × 10^110 ≈ -10^110. The impact is that the mass of globular (galaxies) is getting bigger. In the theory of gravity, EiBI (with parameter κ = 5 m^2 [4]) also does not have much impact on the mass of galaxy objects because the result of the order of mass correction with EiBI is also small, namely 10^(-46). Then in order to have an impact, the κ parameter is varied, and the range value is 5 × 10^38 ≤ κ ≤ 5 × 10^40 m ^2. The impact is that the globular mass is getting smaller. However, the BHG theory of gravity directly impacts the mass of the galaxy without varying its parameters, with the parameter Υ = -0,1655 [5]. The impact that occurs is to increase the overall mass of the cluster galaxy. Then the impact of this BHG theory is to reduce the value of the R-correlation (linear regression of the curve), which is obtained by fitting ratio from the equation M = (M_dyn^c)/(M_bar^c ) [6] originally obtained M = 0,84 ± 0,04 [6] becomes M = 0,316 ± 0,00044, it can be concluded that due to changes in mass in the BHG theory can reduce the value of its R-correlation."

"ABSTRAKSamsung merupakan salah satu merek terbesar di industri tekonologi komunikasi sedangmengalami krisis menjelang akhir tahun 2016 tepatnya pertengahan Oktober 2016 dimana salah satuproduk smartphone terbaru mereka yakni Samsung Galaxy Note dilaporkan meledak oleh konsumenmereka yang awalnya ada salah satu konsumen yang mengungah video di Youtube mengenai kejadiantersebut yang menjadi viral dan setelah itu muncul laporan-laporan lain mengenai kejadian tersebutdari berbagai Negara bahkan sampai ada pelarangan menggunakan telepon genggam tersebut di dalampenerbangan pesawat karena produk tersebut dianggap berbahaya sehingga hal ini menjadi berita yangbesar dan Samsung-pun melakukan penarikan kembali terhadap produk tersebut dengan memberikanpergantian uang juga voucher untuk pembelian produk Samsung yang lain namun hal tersebut tidakmembuat kepercayaan banyak konsumen Samsung terhadap merek Samsung itu sendiri menjadi pudarhal itu didapatkan dari beberapa survei online salah satunya dari Reportlinker.com yang menyatakanbahwa 86% dari 500 responden menyatakan bahwa mereka akan memikirkan untuk memilih Samsungkembali pada dalam pembelian telepon genggam baru di waktu yang akan datang. Oleh sebab itupenulis membahas konsep brand trust terhadap konsumen terhadap produk Samsung yang membuatkonsumen untuk tetap percaya terhadap Samsung, penulis juga menggunakan konsep brand experiencedan word of mouth dalam kasus ini karena pengalaman konsumen sebelumnya juga berpengaruhterhadap brand trust dan word of mouth konsumen yang positif di forum-forum online maupunkomentar di media sosia seperti Youtube juga membantu merek untuk menghadapi krisis.

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ABSTRACTSamsung is one of the biggest in the communication and technologies industry who facing a crisistowards the end of 2016 precisely on mid-October 2016 in which one their latest smartphone productthe Samsung Galaxy Note reportedly exploded by their customers that initially there was one of theircustomer uploaded a video on Youtube about the incident and that became viral, after it appeared thereare another reports on the incident from various countries moreover there is ban to bring cell phone inthe aircraft's flight because these products are considered dangerous, so it is becoming big news andSamsung also conduct a recall of these products by providing money turnover also vouchers for thepurchase of another Samsung product, but it does not make a lot confidence towards Samsung itself hasfaded. it obtained from several online surveys, one of which came from Reportlinker.comwhich states that 86% of the 500 respondents said that they would think of to chooseSamsung back on the purchase of a new mobile phone in the future. Therefore, the authorsdiscuss the concept of brand trust of the consumer to the product Samsung, which led consumers tocontinue to believe against Samsung, the author also uses the concept of brand experience and word ofmouth in this case because the consumer experience previously also affects brand trust and positiveword of mouth consumers in online forums and their comments on social media like Youtube also helpthe brand to face the crisis."

"Menguji validitas relativitas umum dapat dilakukan dengan memodifikasinya untuk mencari penyimpangan. Beberapa teori gravitasi termodifikasi menghasilkan potensial gravitasi dengan suku eksponensial yang menyerupai potensial Yukawa untuk aproksimasi medan lemah. Walaupun pengujian eksperimental dari koreksi Yukawa masih terbatas pada skala sistem tata surya, beberapa penelitian terbaru telah menggunakan data dari kurva rotasi galaksi untuk membatasi parameter Yukawa ini secara observasional, namun dengan asumsi bahwa barion terkopel secara lemah dengan gravitasi untuk memenuhi batasan gravitasi lokal. Studi kami mengabaikan asumsi ini dan menganalisis suku koreksi Yukawa baik dalam halo materi gelap maupun komponen bariyonik. Kami menyelidiki empat model: Newton, Almeida, MG, dan MG Duo, berdasarkan keberadaan suku koreksi Yukawa dalam komponennya dan kopling antar jenis partikel. Kami menguji keempat model ini pada tiga set data yang berbeda dari galaksi Bima Sakti, termasuk data Sofue (2015, 2017, dan 2020) dan data kurva rotasi dari Gaia DR3 oleh Wang (2023) dan Zhou (2023). Kami menemukan dukungan statistik yang kuat melalui faktor Bayes untuk model MG Duo yang menunjukkan kopling terpisah antara baryon-baryon dan baryon-DM. Namun, data observasional yang lebih tepat yang mencakup rentang radius galaksi yang lebih luas masih diperlukan untuk meningkatkan pemahaman tentang modifikasi di wilayah dalam galaksi Bima Sakti.

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Testing the validity of general relativity can be done by modifying it to search for potential deviations. Several modified gravity theories introduce a Yukawa-like exponential term in the gravitational potential for weak-field limits. While experimental tests of the Yukawa-correction are limited to Solar system scales, recent studies have used galactic rotation curve data to observationally constrain these Yukawa parameters, although assuming that baryons are weakly coupled to gravity to satisfy local gravity constraints. In our study, we relax this assumption and analyze the Yukawa-correction in both dark matter halo and baryonic components. We investigate four models: Newtonian, Almeida, MG and MG Duo models, based on the presence of the Yukawa-correction term in the components and the coupling between particle species. We tested these models on three Milky Way datasets: Sofue (2015, 2017, 2020) and rotation curves by Wang (2023) and Zhou (2023) derived from Gaia DR3 data. We find strong statistical favor through the Bayes factor for the MG Duo model that presents a separated coupling between baryon-baryon and baryon-DM. However, more precise observational data covering a broader range of galactic radii is still required to enhance our understanding of modifications in the inner regions of the Milky Way."

"The aim of this symposium was to bring together these two groups to exchange ideas and new results on the many evolutionary aspects of and open issues concerning dwarf galaxies. The main topics addressed include, the birth of dwarf galaxies: theoretical concepts and observable relics across wavelengths and time, the morphological, structural and chemical evolution of dwarf galaxies, possible evolutionary connections between early-type and late-type dwarfs, the star formation history of dwarf galaxies and its dependence on intrinsic and environmental properties, the origin and implications of starburst activity in dwarf galaxies, the fate of dwarfish systems born out of tidally ejected matter in galaxy collisions."

"ABSTRAKTesis ini merupakan sebuah studi mengenai teori spiral of silence yang dilakukan dengan mengamati perilaku seseorang dalam melakukan sensor diri dan aktivitas politik di media sosial. Seperti kita ketahui, media sosial belakangan ini telah menjadi wadah pengungkapan pendapat politik yang nyaman bagi penggunanya. Kondisi ini kemudian membuat penulis bertujuan untuk meneliti eksistensi dari efek spiral of silence di kalangan pengguna media sosial. Tesis ini dilakukan dengan menggunakan metodologi penelitian kuantitatif melalui penyebaran kuesioner secara online pada kalangan mahasiswa yang tergabung sebagai pengurus harian Badan Eksekutif Mahasiswa tingkat fakultas di kampus UI. Data yang berhasil dihimpun kemudian diolah dengan menggunakan perhitungan statistik. Hasil dari penelitian tesis ini adalah dapat dibuktikan bahwa efek spiral of silence masih berlaku di kalangan pengguna media sosial Indonesia, di mana mereka masih berupaya untuk melakukan penyesuaian sosial dengan tidak memperlihatkan pendapat mereka atas suatu peristiwa politik di media sosial Facebook, Twitter, Instagram, Line, dan Whatsapp.

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ABSTRACTThis thesis is a study about spiral of silence theory in social media, with the concentration to willingness to self censorship and political posting activity behavior. The condition that showed social media has become a convenient medium to show political opinion of its users had pumped the couriosity of the author to know about the existence of spiral of silence effect on this kind of digital media. As one of the popular mass media effects theory, the spiral of silence has the fear of social isolation as the key variable that drives spiral effect. This thesis is done by using quantitative research through the dissemination of cross sectional design questionnaire online. The questionnaire which contains questions about the Zaadit 39 s Yellow Card event which became a popular agenda in social media was disseminated to a group of students who were members of the daily board of the Student Council in Universitas Indonesia. The collected data then processed using statistical calculations. The result of this thesis is that it can be proven that the spiral of silence effect is still prevalent among Indonesian social media users, which they did not want to show their opinion about a political issue on social media such as Facebook, Twitter, Instagram, Line, and Whatsapp. Nevertheless, the authors will conduct research conducted on different populations that will be able to produce different findings, given that this research is conducted on respondents who came from mass affluent backgrounds. "