Judul: Analisis Volatilitas Return Saham Konvensional dan Syariah Sebelum dan Saat Pandemi Covid-19
Abstrak: Volatilitas return saham merupakan suatu acuan risiko yang terjadi di pasar saham. Adanya pandemi Covid-19 dan guncangan makroekonomi berdampak pada volatilitas return saham konvensional dan syariah. Penelitian ini menggunakan metode analisis ARCH/GARCH untuk menganalisis volatilitas dan metode ARDL-ECM untuk menganalisis faktor makroekonomi yang berpengaruh terhadap volatilitas. Hasil penelitian menunjukkan bahwa volatilitas pada pasar saham syariah lebih stabil jika dibandingkan dengan pasar saham konvensional pada periode sebelum dan saat pandemi Covid-19. Temuan ini juga diperkuat dengan hasil analisis dengan metode ARDL menunjukkan bahwa pasar saham syariah lebih cepat untuk kembali pada keseimbangan. Sensitivitas terhadap guncangan indikator makroekonomi dari pasar saham syariah lebih rendah dibandingkan dengan saham konvensional. Indikator makroekonomi yang berpengaruh terhadap volatilitas saham konvensional yaitu Indeks Harga Konsumen, harga minyak dunia, dan pandemi Covid-19. Sementara untuk saham syariah hanya dipengaruhi Indeks Produksi Industri dalam jangka panjang., The volatility of stock returns was a reference for risks that occurred in the stock market. The emergence of the Covid-19 pandemic and macroeconomic shocks impacted the volatility of Conventional and Sharia returns. The research used the ARCH/GARCH analysis method to analyze volatility and the ARDL-ECM method to analyze macroeconomic factors that influence volatility. The results showed that volatility in the Islamic stock market is more stable when compared to the conventional stock market in the period before and during the Covid-19 pandemic. The sensitivity to macroeconomic indicator shocks from the Islamic stock market is lower than Conventional stocks. Macroeconomic indicators that influenced stock convention volatility were the CPI, world oil prices, and the Covid-19 pandemic. Meanwhile, Sharia stocks only affected IPI in the long run.
Keyword: Conventional Stock Index,, Pandemic, Sharia Stock Index, Stock Return, Volatility

Judul: Analysis of Returns and Risks of Sharia Stocks Portfolio and Conventional Stocks Portofolio with the Efficient Frontier Method
Abstrak: Kondisi pandemi di Indonesia, yang menjadi salah satu penyebab jumlah investor saham naik signifikan, membuat saham syariah semakin diminati. Kenaikan jumlah peminat tersebut harus dibarengi dengan kenaikan angka literasi saham syariah agar umat islam di Indonesia bisa berinvestasi dan tetap menjalankan aturannya sebagai seorang muslim. Perlu dilakukan analisis portofolio saham syariah dan konvensional agar bisa diketahui potensi dari kedua portofolio saham. Data yang digunakan untuk portofolio saham syariah adalah data saham Telkom dan Unilever, sedangkan untuk portofolio saham konvensional adalah data saham BCA dan BRI periode 1 Januari 2012-31 Desember 2018. Dilakukan pemodelan ARMA-GARCH untuk menghilangkan efek autokorelasi dan heteroskedastisitas pada galat. Setelah itu dilakukan pemodelan Copula untuk membentuk fungsi sebaran bersama galat baku. Selanjutnya dibuat grafik efficient frontier dari kedua portofolio dan dianalisis dengan asumsi risiko minimum, imbal hasil maksimum, dan reward-to-variability ratio maksimum. Hasil analisis tersebut menunjukkan portofolio saham syariah relatif lebih cocok dipilih bagi investor moderat, sedangkan portofolio saham konvensional relatif lebih cocok dipilih bagi investor agresif., Pandemic conditions in Indonesia, which one of the causes the number of stock investors increase significantly, the sharia stock becomes more interesting. The increase in the number of enthusiasts must be accompanied by an increase in the literacy rate of the sharia stock so that Muslims in Indonesia can invest and continue to carry out their rules as a muslim. It is necessary to analyze the returns and risks of sharia and conventional stock portfolio so that the potential of these two stocks portfolio can be seen. The data used for sharia stocks portfolio are Telkom and Unilever, whereas the data used for conventional stocks portfolio are BCA and BRI for the period 1 January 2012-31 December 2018. ARMA-GARCH modeling was carried out to eliminate the effects of autocorrelation and heteroscedasticity on the errors. After that, Copula modeling was carried out to form a joint cumulative distribution function of standard errors. Next, an efficient frontier graphs were made of those portfolios and analyzed with the assumption of minimum risk, maximum return, and maximum reward-to-variability ratio. The results of the analysis show that the sharia stock portfolio is relatively more suitable for moderate investors, while the conventional stock portfolio is relatively more suitable aggresive investors.
Keyword: return, risk, sharia stock, conventional stock, efficient frontier

Judul: Membran Selulosa Berbahan Dasar Kulit Buah Nanas sebagai Adsorben Zat Warna Tekstil Biru Metilena
Abstrak: Treatment of various fruit pineapple in daily life created a problem of the environment, such as build up of peel waste. The waste could be transformed further to microbial cellulose (nata de pina) by using microorganisms Acetobacter xylinum. The application of microbial cellulose produced flux of 4.72-65.56 L/m2.h. The rejection membrane of methylene blue was 90 - 98 %, meaning that the membrane was able to adsorb methylene blue. Based on analysis using Fourier transform infrared and scanning electrone microscope the membrane composed of cellulose, with the type of asymmetry, and has pore size 20-50 nm as ultrafiltration membrane.
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