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Abstrak :
The geomagnetic fields in the atmosphere can be affected by phenomena in the Earth, so that changes of geomagnetic intensity might be used as an indicator of earthquake occurrences. Variations of geomagnetic data have been analyzed in association with the Tohoku Earthquake on March 11th 2011. The Geomagnetic data have been derived from Memambetsu (MMB), Kakioka (KAK) and Kanoya (KNY) Observatories, which are INTERMAGNET observatories. The analysis was performed by calculating the power spectral density (psd) of the ULF signal of Z and H components and then polarizations are observed by comparing the psd of Z and of H. The results showed the difference psd of Z and of H between the KAK observatory (the nearest position to the epicenter) with MMB and KNY (at some greater distance from the epicenter) is quite significant, which can be observed over a period of 10 days before the earthquake occurrence. The polarizations of Z/H in KAK indicate a highest change of intensity which occurred at 18 days prior to the earthquake.

Abstrak :
Why do some Americans oppose social distancing and lockdown policies in response to the COVID-19 pandemic? This study argues that, given the current trends in affective polarization, partisanship is a factor that could influence individuals’ attitudes and behaviors toward social distancing and lockdown policies. Moreover, the effect of partisanship on individuals’ attitudes and behaviors toward social distancing and lockdown policies can be mediated by their level of trust in partisan leadership’s information. By conducting chi-square tests, t tests, and ANOVA tests on a public opinion survey implemented by the Kaiser Family Foundation during March 25th-30th, 2020, we find that being a Republican is strongly related to holding negative behaviors and attitudes toward social distancing and lockdown policies. Furthermore, by employing logistic regression, multinomial logistic regression, and causal mediation analysis, we find that Republicans have a higher likelihood of opposing social distancing and lockdown policies because they trust president Trump to provide them with reliable information on the coronavirus.

Abstrak :
Dalam sistem komunikasi WLAN, peran antena merupakan elemen penting berfungsi sebagai pengirim dan penerima gelombang elektromagnetik yang berisi informasi-informasi dari media kabel ke udara atau sebaliknya. Teknologi nirkabel dengan standar IEEE 802.11 dan berdasarkan peraturan KOMINFO 2019 menuntut memiliki antena yang dapat menyesuaikan diri terhadap lingkungan yang berubah-ubah. Antena yang digunakan dalam jaringan WLAN disesuaikan dengan lingkup jangkauan yang diharapkan. Antena polarisasi melingkar adalah pilihan paling jelas bagi peneliti dimana dapat mengatasi kelemahan pada polarisasi linier, seperti, kerugian akibat ketidaksesuaian polarisasi, kerentanan terhadap efek multipath dan fading, rotasi Faraday, dan kondisi cuaca buruk. Untuk memenuhi perkembangan teknologi saat ini jenis antena mikrostrip adalah solusi yang baik, karena memiliki beberapa keunggulan seperti bentuk yang sederhana, bobot yang ringan, pembuatan yang mudah dan biaya yang murah. Pada buku tesis ini diusulkan antena mikrostrip yang dapat rekonfigurasi polarisasi dengan menggunakan U-slot pada frekuensi 2,4 GHz untuk aplikasi WLAN. Teknik U-slot yang disisipkan pada patch antena membuat pengaruh hasil polarisasi menjadi melingkar kiri atau kanan. Diusulkan rekonfigurasi polarisasi antena mikrostrip dengan menggunakan dua (2) buah switching on dan off yang dinyalakan salah satu maupun bersamaan. Simulasi yang dilakukan menunjukkan bahwa antena 1 dan antena 2 memiliki polarisasi linier (LP), antena 1 memiliki bandwidth 75 MHz (2,40 GHz – 2,48 GHz) dan antena 2 memiliki bandwidth 77 MHz (2,40 GHz – 2,48 GHz) dengan batasan nilai S- parameter ≤­9,54 dB. Antena 3 memiliki polarisasi melingkar LHCP (left-hand circular polarized) dengan nilai bandwidth 133 MHz (2,35 GHz – 2,48 GHz) dan antena 4 memiliki polarisasi melingkar RHCP (right-hand circular polarized) dengan nilai bandwidth 133 MHz (2,39 GHz – 2,48 GHz) pada batasan Axial Ratio (AR) ≤3. Hasil pengukuran yang diperoleh pada antena 1 dan antena 2 memiliki polarisasi linier, dimana antena 1 memiliki nilai bandwidth sebesar 85 MHz (2,39 GHz – 2,48 GHz) sedangkan pada antena 2 memiliki bandwidth 68 MHz (2,40 GHz – 2,46 GHz). Antena 3 memiliki polarisasi melingkar LHCP dengan bandwidth sebesar 69 MHz (2,40 GHz – 2,46 GHz). Pada antena 4 memiliki polarisasi melingkar RHCP dengan nilai bandwidth sebesar 75 MHz (2,39 GHz – 2,46 GHz). Seluruh antena pada hasil simulasi dengan hasil pengukuran sesuai memiliki spesifikasi antena WLAN sehingga antena ini dapat beroperasi untuk WLAN. ......In WLAN communication systems, the role of the antenna is an important element to function as a sender and receiver of electromagnetic waves containing information from cable media to air or vice versa. Wireless technology with the IEEE 802.11 standard and based on the 2019 KOMINFO regulations demands having an antenna that can adapt to changing environments. The antennas used in WLAN networks are adjusted to the expected coverage scope. Circular polarizing antennas are the most obvious choice for researchers in overcoming weaknesses in linear polarization, such as losses due to polarization mismatch, susceptibility to multipath and fading effects, Faraday rotation, and adverse weather conditions. To meet current technological developments this type of microstrip antenna is a good solution, because it has several advantages such as a simple shape, light weight, easy manufacture and low cost. In this thesis book proposed a microstrip antenna that can reconfigure polarization using U-slot at a frequency of 2.4 GHz for WLAN applications. The U-slot technique inserted in the antenna patch makes the polarization result affect the left or right circular. It is proposed to reconfigure the polarization of the microstrip antenna by using two (2) switching on and off which are turned on one or simultaneously. The simulation shows that Antenna 1 and Antenna 2 have linear polarization (LP), antenna 1 has a bandwidth of 75 MHz (2.40 GHz – 2.48 GHz) and antenna 2 has a bandwidth of 77 MHz (2.404 GHz – 2.481 GHz) with a limitation of the value of the S-parameter ≤9.54 dB. Antenna 3 has LHCP (left-hand circular polarized) circular polarization with a bandwidth value of 133 MHz (2.35 GHz – 2.48 GHz) and antenna 4 has RHCP (right-hand circular polarized) circular polarization with a bandwidth value of 133 MHz (2.39 GHz – 2.48 GHz) at the Axial Ratio (AR) limit of ≤3. The measurement results on antenna 1 and antenna 2 have linear polarization, where antenna 1 has a bandwidth value of 85 MHz (2.39 GHz – 2.48 GHz) while antenna 2 has a bandwidth of 68 MHz (2.40 GHz – 2.46 GHz). Antenna 3 has LHCP circular polarization with a bandwidth of 69 MHz (2.40 GHz – 2.46 GHz). Antenna 4 has a circular polarization RHCP with a bandwidth value of 75 MHz (2.39 GHz – 2.46 GHz). All antennas in the simulation results with the appropriate measurement results have WLAN antenna specifications so that this antenna can operate for WLAN.

Abstrak :
Prevalensi konsumsi diet tinggi lemak yang menimbulkan obesitas meningkat cepat dalam 2 dekade terakhir. Diabetes melitus tipe 2 berasosiasi dengan kenaikan konsentrasi penanda inflamasi berupa protein fase akut dalam darah yaitu high sensitive C-reactive protein ( hs-CRP), serum sialic acid, dan fibrinogen. Diabetes melitus tipe 2 merupakan kombinasi dari gaya hidup dan faktor genetik. Berdasarkan hal tersebut, individu dengan First Degree Relative ( FDR) diabetes melitus memiliki risiko yang lebih tinggi mengembangkan diabetes melitus. Sel T merupakan leukosit yang berkembang dalam timus dan berperan dalam respons imun adaptif. Polarisasi sel T akan menggambarkan profil sel imun adaptif pada gejala inflamasi kronis. Maka dari itu, penelitian ini bertujuan untuk mengetahui polarisasi sel T pada subjek First Degree Relative (FDR) yang beresiko diabetes melitus tipe 2 yang diinduksi dengan diet tinggi lemak. 30 subjek NFDR dan FDR yang telah masuk parameter inklusi diberikan diet tinggi lemak 250 ml per hari selama 5 hari. Sample darah subjek sebelum dan sesudah induksi dilakukan uji profil darah dan diperiksa subset sel T menggunakan metode flowcytometry. Pada penelitian ini didapatkan bahwa Keadaan Th17 yang tinggi pada sebelum dan sesudah HFD yang di dominasi NFDR diikuti dengan naiknya sel Treg dan  kadar IL-10 Pre HFD yang tinggi secara signifikan akan menurunkan produksi kolesterol dan LDL secara signifikan. ......The prevalence of high-fat diet consumption that triggered obesity is increasing in last 2 decades. Type 2 diabetes mellitus is associated by the increasing number of inflammation marker, acute phase protein in blood serum. In type 2 diabetes mellitus, combination of lifestyle and genetic factors is the most influential factors. Due to that fact, person with First Degree Relative ( FDR) in type 2 diabetes mellitus has the higher risk to develop into type 2 diabetes mellitus. T cell is one of leucocyte that has a significance role in adaptive immune response.T cell polarization will show the profile of adaptive immune response in chronic inflammation. This study is purposed to analyse how T cell polarized in First Degree Relative (FDR) subject in risk of type 2 diabetes mellitus with high fat diet treatment. 30 NFDR subjects and 30 FDR subjects who included in parameter inclusion were treated with 250 mL whipping cream per day in 5 days. Pre and post treatment blood collection were tested for blood profile and flowcytometry intraseluler staining. This study found that there is a change in Th17 dominantly in NFDR subject followed by the significantly increasing amount of Treg cell and IL-10 which decreasing the cholesterol and LDL significantly.

Abstrak :
Komunikasi nirkabel menjadi kebutuhan mendasar seiring dengan perkembangan teknologi komunikasi karena menawarkan biaya yang lebih rendah, fleksibilitas dan kenyamanan yang lebih tinggi, peningkatan kecepatan dan konektivitas yang konstan, serta aksesibilitas ke daerah yang jauh. Salah satu contoh teknologi komunikasi yang berkembang pesar saat ini adalah teknologi VSAT (Very Small Aperture Terminal). VSAT adalah stasiun bumi satelit dua arah yang beroperasi pada frekuensi C-band dan Ku-band, dengan dua macam polarisasi (linear dan melingkar) di C-band dan polarisasi linear di Ku-band. Agar data yang dipancarkan satelit dapat dimanfaatkan oleh pengguna sistem komunikasi, maka dibutuhkan antena pada sisi pengguna yang memiliki karakteristik dual wideband dengan dual-polarization. Penelitian ini merancang antena planar dual wideband dual-polarization dengan metode pemasangan dua port. Dalam proses perancangan antena dualband, pemberian slot pada patch mampu menghasilkan karakteristik dualband. Selain untuk memberikan karakteristik polarisasi melingkar, metode pertubasi juga dapat dilakukan untuk menambahkan karakteristik wideband pada antena. Agar antena dapat menghasilkan karakteristik polarisasi melingkar, dapat dilakukan dengan memberikan slot pada ground antena. Rancangan antena yang diusulkan memiliki frekuensi resonan yaitu 3,75 – 4,68 GHz dan 5,6 – 9,3 GHz pada port 1 serta 3,13 – 5,72 GHz dan 10,41 – 12,29 GHz pada port 2. Antena memiliki karakteristik polarisasi melingkar (RHCP) pada port 1 dan polarisasi linear pada port 2. Pada port 1, gain di frekuensi 4,2 GHz dan 6,2 GHz masing-masing terukur pada nilai 3,4 dB dan 4,5 dB, sedangkan pada port 2, gain di frekuensi 3,9 GHz, 6,13 GHz dan 11,8 GHz masing-masing terukur pada nilai 2,12 dB, 2,52 dB dan 6,13 dB. Antena mampu beresonansi di sebagian frekuensi C-band (port 1), baik pemancar dan penerima, serta sebagian frekuensi penerima Ku-band (port 2). Antena yang diusulkan memiliki dimensi yang kecil (30 mm x 39 mm x 1,52 mm), serta desain yang lebih compact dan sederhana sehingga memudahkan proses fabrikasi.

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Wireless communication has become a fundamental requirement along with the development of communication technology because it offers lower costs, higher flexibility and convenience, constant increases in speed and connectivity, as well as accessibility to remote areas. One example of a communication technology that is currently developing rapidly is VSAT (Very Small Aperture Terminal) technology. VSAT is a two-way satellite earth station operating on the C-band and Ku-band frequencies, with two kinds of polarization (linear and circular) in the C-band and linear polarization in the Ku-band. In order for the data transmitted by the satellite to be utilized by users of the communication system, an antenna on the user side that has dual wideband characteristics with dual-polarization is needed. This study designed a dual-polarization planar antenna with a two-port installation method. In the process of designing a dualband antenna, providing a slot on the patch can produce dualband characteristics. In addition to providing circular polarization characteristics, the pertubation method can also be used to add wideband characteristics to the antenna. So that the antenna can produce circular polarization characteristics, it can be done by providing a slot in the antenna ground. The proposed antenna design has resonant frequencies, namely 3.75 - 4.68 GHz and 5.6 - 9.3 GHz on port 1 and 3.13 - 5.72 GHz and 10.41 - 12.29 GHz on port 2. The antenna has a circular polarization characteristic (RHCP) on port 1 and linear polarization on port 2. At port 1, the gain at a frequency of 4.2 GHz and 6.2 GHz is measured at a value of 3.4 dB and 4.5 dB, respectively, while at port 1 port 2, the gain at a frequency of 3.9 GHz, 6.13 GHz and 11.8 GHz, respectively measured at a value of 2.12 dB, 2.52 dB and 6.13 dB. The antenna is capable of resonating on part of the C-band (port 1) frequencies, both transmitter and receiver, as well as part of Ku-band (port 2) receiver frequencies. The proposed antenna has small dimensions (30 mm x 39 mm x 1.52 mm), as well as a more compact and simple design that facilitates the fabrication process.

Abstrak :
Penelitian ini dilakukan di lapangan GB untuk mendeteksi keberadaan mineral emas dengan metode Induced Polarization IP . Berdasarkan geologi, terdapat adanya sistem epitermal sulfidasi tinggi di wilayah ini. Hal ini ditandai dengan munculnya keberadaan mineral-mineral logam seperti Au, Cu, dan konsentrasi yang cenderung asam di permukaannya. Mineral emas sendiri merupakan mineral yang bersifat diamagnetik, lunak, dan berasosiasi dengan mineral sulfida. Emas terbentuk akibat dari adanya proses magmatisme atau pengkonsentrasian di permukaan. Mineral emas terangkut oleh fluida hidrotermal ke permukaan dan terbentuk dalam lingkungan hidrotermal dimana ia terbawa ke permukaan bersama dengan senyawa-senyawa yang berikatan dengannya. Metode IP memanfaatkan beda potensial sebagai parameter dalam melakukan pengukuran untuk mendeteksi keberadaan mineral-mineral konduktif di bawah permukaan tanah. Kelebihan metode IP dibanding metode lain adalah kemampuannya mendeteksi mineral logam yang tersebar. Pada penelitian ini digunakan dari 6 data line IP yang dibentangkan ke arah Barat ndash; Timur serta didukung oleh data magnetik. Data diolah dengan inversi 2D dan dimodelkan secara 3D dengan membentangkan hasil secara paralel. Hasilnya, nilai chargeability tertinggi bernilai > 200 ms pada kedalaman 400 meter. Hal ini didukung dengan nilai resistivity yang mencapai > 1000 ohm-meter. Dari data magnetik, nilai magnetik berkisar antara -199.3 nT sampai 244 nT. ......This research was conducted in field GB to identify the presence of gold minerals by Induced Polarization IP method. Based on geology, there is a high sulfidation epithermal system in the region. This can be determined by the presence of metal minerals such as Au, Cu, and acid concentrations on the surface. Gold is a typical of mineral that is diamagnetic, pliable, and associated with sulphide minerals. It is formed as a result of the process of magmatism or metasomatism on the surface. The hydrothermal fluid content transports gold to the surface along with the other elements associated to it and is formed in hydrothermal environment. The IP method utilizes a potential difference as a parameter in performing measurements to detect the presence of underground conductive minerals. The advantage of IP methods compared to other methods is its ability to detect disseminated conductive minerals. This research use 6 line datas of IP which is extended to West ndash East and supported by magnetic data. Data is processed with 2D inversion and modeled in 3D by spreading results in parallel. As a result, the highest value of chargeability is 200 ms at a depth of 400 meters. This is supported by a resistivity value of 1000 ohm meter. From magnetic data, magnetic values range from 199.3 nT to 244 nT.

Abstrak :
Komunikasi Satelit adalah suatu sistem komunikasi dengan media transmisinya menggunakan satelit, yang berfungsi sebagai repeater tunggal. Letak satelit yang jauh dan terbatasnya alokasi frekuensi mengakibatkan dibuatkannya perbedaan arah rambatan gelombang radio (polarisasi) menjadi dua polarisasi yaitu polarisasi horizontal dan polarisasi vertikal. Perbedaan polariasi akan mengakibatkan terjadinya Cross Polarization Interference (CPI) / crosspol yang berdampak terjadinya penurunan kualitas transmisi, maka tes crosspol merupakan salah satu solusinya. Satelit melakukan pergerakan terhadap posisi bumi tetapi masih di daerah posisi opersionalnya (box keeping). Hal ini bertujuan untuk mempertahankan posisi satelit terhadap bumi yang melakukan pergerakan juga. Pergerakan satelit ini berdampak terhadap perubahan kondisi arah polarisasi, maka pergerakan satelit dibatasi sebesar 0,05°. Skripsi ini bertujuan untuk mengetahui seberapa besar dampak dari pergerakan satelit terhadap nilai crosspol, yang dapat diketahui dengan hasil perhitungan link budget. Berdasarkan hasil pengukuran crosspol dan perhitungan C/Ntotal didapati kondisi link yang pergerakan satelitnya dibatasi sebesar 0,05 dalam keadaan baik, karena nilai C/Ntotal yang fluktuatif tidak terlalu besar perubahannya.

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Satellite communication is a communication system using satellite transmission media, which functions as a single repeater. Location of satellite remote and limited frequency allocation resulted in differences in the direction of propagation of radio waves (polarization) into two polarization of horizontal polarization and vertical polarization. Polariasi differences will result in Cross Polarization Interference (CPI) / crosspol which affects the transmission quality decrease, then the test crosspol is one solution. Satellite earth-movement against the position but still in the area opersionalnya position (box keeping) it aims to maintain the position of the satellite to the earthmovement as well. This satellite movement resulted in a change of polarization direction conditions, the satellite movement is restricted by 0.05 °. This essay aims to find out how big the impact of satellite movement against crosspol value, which can be determined by the calculation of link budget. Based on the results of measurements and calculations crosspol C/Ntotal found to condition the movement of satellite links is limited by 0.05 in good condition, because the value of C/Ntotal fluctuation is not too large changes.

Abstrak :
It has been shown the response of two dimension a VLF electromagnetik wave to homogenous and isotropic limestone models (karst area) with both air cavities (cave) only and air civities(cave) with a river flow in the cave.....

Abstrak :
Hyperduplex Stainless Steel 3207 (SAF 3207 HD) is one of the materials used in the oil and gas industry, especially for umbilical, which is a system to connect cables or instrumental setups between control platforms and wellhead station. It is used in deep water containing high chloride ion (Cl-), so it needs high tensile strength and must be a highly corrosion-resistant material. In this research, several corrosion resistance tests were conducted on 3207 hyperduplex stainless steel such as polarization and weight loss testing. Roughness surface tests were carried out to observe alterations to the surface caused by underwater corrosion. SAF 3207 HD can form a passive layer due to an environmental reaction; to observe this phenomenon, an EIS test was conducted at the interface of the material. The weight loss test was conducted on a particular sample, in accordance with ASTM G48-97 method B. The corrosion test was carried out at temperatures of 60-90°C (at 5°C intervals) in 6% FeCl3 solution. The results show that SAF 3207 HD has good crevice corrosion resistance, although crevices were not seen below temperatures of 70oC, which is known as critical crevice temperature. At this temperature, the corrosion rate reached 10.032 mm/year and the crevice depth was 1.034 ?m. This means that the operating temperature of the umbilical can be increased up to 70oC.