Siti Nurul Khotimah
Institut Teknologi Bandung

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PENGARUH POSISI INTRUDER TERHADAP BENTUK PERMUKAAN BED GRANULAR PADA EFEK KACANG BRASIL DUA-DIMENSI Viridi, Sparisoma; Khotimah, Siti Nurul; Wibowo, Hari Anggit Cahyo; Ain, Trise Nurul; Aji, Dimas Praja Purwa
Jurnal Spektra Vol 16, No 1 (2015): Spektra: Jurnal Fisika dan Aplikasinya
Publisher : Jurnal Spektra

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Abstract

AbstrakEfek kacang Brasil dua-dimensi dengan partikel bed dan intruder terbuat dari keping akrilik diamati dengan vibrasi sinusoidal yang diselingi waktu diam sehingga memudahkan untuk mengambil foto yang baik untuk diproses lebih lanjut. Parameter vibrasi adalah f = 13 Hz dan Γ = 2. Dalam tulisan ini disajikan evolusi posisi intruder dengan waktu apung Trise = 67 langkah, dengan posisi awal intruder saat sisi bawahnya mengenai dasar wadah dan posisi akhir saat sisi atasnya menyentuh permukaan bed partikel. Tinggi bed partikel awal adalah 21 buah dan lebarnya adalah 19 buah. Rasio intruder dan bed kira-kira 2.545. Bentuk permukaan bed paling melengkung diamat saat posisi intruder berada di antara konfigurasi awal dan akhir dalam observasi.AbstractTwo-dimension Brazil-nut effect using acrylic plate as intruder and bed particles is observed under non-continuous sinusoidal vibration in order to obtain sufficient image quality for further process. Vibration parameters are f = 13 Hz and Γ = 2. In this work time series of intruder position is presented, which shows that it has rise time Trise = 67 steps, with initial position defined as lower side of intruder in touch with bottom of the container and final position is defined as upper side of intruder is on the bed particle surface. Initial height and width of bed particles are 21 and 92 particles, respectively. Ratio of intruder and bed particle diameter is about 2.545. Most curved of bed particle surface is observed while intruder position is about in the middle between its initial and final configurations.Keywords: Brazil-nut effect, granular materials, two-dimension system, vertical vibration, rise time.
Analisis Spektral Daya dan Koherensi EEG Pada Anak Penderita Autism Spectrum Disorders (ASD) Handayani, Nita; Pratama, Sra Harke; Khotimah, Siti Nurul; Arif, Idam; Haryanto, Freddy
Wahana Fisika Vol 2, No 2 (2017): Desember
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/wafi.v2i2.9374

Abstract

Autism Spectrum Disorders (ASD) adalah kondisi neurodevelopmental yang berkaitan dengan defisit dalam fungsi eksekutif, emosi, bahasa, dan komunikasi sosial. Beberapa teknik neuroimaging dan neurofisiologi digunakan untuk memahami hubungan antara fungsionalitas otak dan perilaku autis. Quantitative Electroencephalography (QEEG) adalah sebuah teknik non-invasif yang dapat digunakan untuk memberikan gambaran fungsionalitas otak melalui beberapa besaran fisis yang dikaji. Pada paper ini akan dibahas tentang karakteristik sinyal listrik otak pada penderita austis berdasarkan analisis QEEG.  Perekaman sinyal otak menggunakan Emotiv Epoc 14 channel (AF3, F7, F3, FC5, T7, P7, O1, O2, P8, T7, FC6, F4, F8, AF4) dan 2 channel referensi (CMS dan DRL). Jumlah subjek uji dalam penelitian sebanyak 6 anak penderita autis dan 5 anak sehat sebagai kontrol dengan rentang usia antara 10-15 tahun. Perekaman otak dilakukan pada kondisi rileks dan mata terutup selama 15 menit. Metode analisis data meliputi pre-processing data EEG untuk menghilangkan noise dan artefak, perhitungan spektral daya menggunakan periodogram Welch, dan analisis konektivitas fungsional otak dengan menghitung besarnya koherensi intra-hemisphere dan inter-hemisphere. Dari hasil studi diperoleh bahwa pada anak autis terjadi peningkatan spektral daya pada pita delta dan penurunan spektral daya pada pita alpha dibandingkan dengan subjek kontrol. Analisis konektivitas fungsional otak pada anak autis menunjukkan nilai koherensi intra-hemisphere dan inter-hemisphere yang lebih rendah pada pita delta dan theta, khususnya pada area frontal. QEEG dapat digunakan untuk karakterisasi sinyal otak pada penderita autis dan membedakannya dari subjek normal.      Kata Kunci   :  Retardasi Mental; Spektral Daya; Koherensi; EEG;  Sinyal Otak Autism Spectrum disorder (ASD) is a neurodevelopmental disorder associated with deficits in executive function, emotions, language, and social communication. Several neuroimaging and neurophysiology techniques are used to understand the relationship between brain functionality and autistic behavior. Quantitative Electroencephalography (QEEG) is a non-invasive technique that can be used to illustrate the functionality of the brain through the analysis of several physical quantities. This paper will discuss about the characteristics of electrical brain signals in austistic children based on QEEG analysis. Recording of brain signals using  Emotiv Epoc 14-channels (AF3, F7, F1, O2, P8, T7, FC6, F4, F8, AF4) and 2 reference channels (CMS and DRL). The number of test subjects in the study were 6 autistic children and 5 healthy children as controls with an age range between 10-15 years old. Brain recording performed on resting state and eyes closed for 15 minutes. The methods of analysis data includes pre-processing EEGs data to remove noise and artifacts, power spectral analysis using Welch Periodogram, and brain functional connectivity analysis by calculating the magnitude of intra-hemisphere and inter-hemisphere coherences. The results of the study found that an increased of power spectral in the delta band and a decreased of power spectral in the alpha band in autistic children compared to control subjects. Analysis of functional connectivity of the brain in autistic children shows lower intra-hemisphere and inter-hemisphere coherences in the delta and theta bands, particularly in the frontal area. QEEG can be used to characterized brain signals in autistic children and differentiated them from the normal subjects.          Keywords  : Mental Retardation; Power Spectral; Coherence; EEG; Brain Signal
Fertility Age Couples Motivation On Cervical Cancer Early Detection Khotimah, Siti Nurul; Ernawati, Dwi
International Journal of Health Science and Technology Vol 3, No 2 (2021): November
Publisher : Universitas 'Aisyiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31101/ijhst.v3i2.1977

Abstract

Cervical cancer is most often attacking women. After breast cancer, cervical cancer becomes second cancer infecting women. (WHO, 2014). This research aims to get the results from the fertility age couples' motivation on cervical cancer early detection.The preparation of a scoping review adapted the Arksey O'Malley framework consisted of 5 stages: research questions with the PEOs framework (Population, Exposure, and Outcomes), searching literature using relevant databases. The 12 articles used to consist of 3 themes, namely sexual and reproductive health problems, sexual health problems, and sexual and reproductive health.