Judul: Pembuatan Hidrogel Nanofiber Selulosa dari Tandan Kosong Kelapa Sawit (TKKS)
Abstrak: Serat selulosa telah berhasil diisolasi dari tandan kosong kelapa sawit (TKKS) melalui proses delignifikasi menggunakan larutan KOH 6% selama 12 jam, kemudian dilanjutkan dengan proses bleaching menggunakan hipoklorit selama 5 jam. Berdasarkan uji ADF NDF, selulosa yang didapatkan memiliki kadar selulosa 69,55%, hemiselulosa 17,76%, dan lignin 5,81%. Selanjutnya nanofiber diisolasi dari selulosa melalui proses mechanical treatment. Gambar SEM menunjukkan bahwa ukuran nanofiber selulosa yang berhasil diisolasi adalah ± 30 nm. Nanofiber selulosa tersebut kemudian dibentuk menjadi hidrogel menggunakan proses vacum filtration dan alkaline treatment. Hidrogel yang dihasilkan menunjukkan bentuk yang lebih stabil dengan tingkat daya serap air yang tinggi. Hidrogel tersebut memiliki potensi untuk digunakan sebagai penutup luka.
Keyword: selulosa, nanofiber selulosa, hidrogel, alkaline treatment

Judul: Isolasi Selulosa nanokristal (SNK) dari Tandan Kosong Kelapa Sawit dengan Hidrolisis Asam Sulfat
Abstrak: Industri minyak kelapa sawit menghasilkan tandan kosong kelapa sawit sekitar 25-26%. Selulosa dalam tandan kosong kelapa sawit mencapai 36,67%, hal ini menjadi peluang baik untuk sintesis selulosa nanokristal (SNK). Sintesis SNK dilakukan dengan menggunakan metode asam kuat (asam sulfat). Asam sulfat menghilangkan sisi amorf selulosa sehingga bagian kristalin dapat diisolasi. Uji berat pulp setelah hidrolisis SNK menunjukan faktor suhu, waktu, konsentrasi asam, interaksi antara suhu dan konsentrasi asam, serta interaksi waktu dan konsentrasi asam berpengaruh secara signifikan terhadap berat pulp setelah hidrolisis SNK. Berat pulp setelah hidrolisis terbaik sebesar 14,98 g, didapat pada hidrolisis dengan suhu 35°C selama 6 jam dan konsentrasi asam 55%. Uji kristalinitas menunjukan faktor suhu, waktu, konsentrasi asam, dan interaksi antar faktor selama hidrolisis tidak berbeda signifikan terhadap persen kristalinitas SNK. Persen kristalinitas sebesar 31,1 %, didapatkan pada hidrolisis dengan suhu 45°C selama 3 jam dan konsentrasi asam 55%. Uji ukuran rata-rata menunjukan faktor suhu, waktu, konsentrasi asam, dan interaksi antar faktor berpengaruh secara signifikan dengan hasil terbaik yaitu 894,25 nm, didapatkan pada hidrolisis dengan suhu 35°C dan konsentrasi asam 60% selama 6 jam. Warna SNK yang dihasilkan berwarna putih dengan dispersi terbaik pada hidrolisis dengan suhu 35°C dan konsentrasi asam 55% selama 6 jam.
Keyword: hidrolisis asam sulfat, selulosa nanokristal, tandan kosong kelapa sawit

Judul: Exchange Market Pressure and Central Bank Intervention for Three ASEAN Countries
Abstrak: Two of the exchange rate systems which are adopted by many countries are the floating and the fixed exchange rate system. Both the exchange rate systems have different characteristics. Countries that implement fixed exchange rates system tend to set their domestic currency exchange rate at a certain point. On the contrary, countries which implement floating exchange rate system tend to let their domestic currency exchange rate to move flexibly and thus their value will always change according to the demand and supply of the currency in the foreign exchange market. Countries which implement floating exchange rate system are facing the risk of fluctuation in the exchange rate of their domestic currency against foreign currencies. The currency exchange rate fluctuation may be caused by economic problems such as a financial crisis. A country can also be potentially affected by other countries’ earlier financial crisis. This effect could potentially happen if these countries are in the same region, such as ASEAN. The 1997 ASEAN economic crisis was an example of a country’s financial crisis could affect other countries. At that time, some countries such as Indonesia, Malaysia and Thailand had to change their currency exchange rate system from the fixed exchange rate system to the floating exchange rate system due to the high costs which has to be incurred if they were to enforce the fixed exchange rate system. During 2002 until 2012, the domestic exchange rate of Indonesia, Malaysia and Thailand against the U.S. dollar had tended to fluctuate. If the domestic currency exchange rate fluctuated excessively then the central bank would intervene to stabilize the exchange rate in the foreign exchange market. The pressure on domestic currency exchange rate pressures has forced the central bank to intervene. The amount of those pressures can be analyzed by calculating the Exchange Market Pressure (EMP) index. Apart from that, the time when interventions are done by the central bank can be known based on EMP by calculating the Exchange Market Intervention (EMI) index. The purposes of this study were to determine the level of international pressure on the currency exchange market and monetary authorities intervene in three ASEAN countries, as well as to determine the effect of the monetary authorities intervene on the exchange rate of the domestic currency against the U.S. dollar in those three ASEAN countries. Based on the EMP index calculation results which are obtained during 2002 to 2012 period, the exchange rate of Indonesia, Malaysia and Thailand’s domestic currency had always fluctuated and the results of the EMP index indicated that each country were under diverse level of currency exchange rate appreciation and depreciation pressures. Thailand was the country with the highest currency exchange rate pressure compared to Indonesia and Malaysia. The results on the intervention index calculation showed that Indonesia, Malaysia and Thailand have intervention index between zero and one and more than one. We can also see from the intervention index that Indonesia and Thailand implement the controlled floating currency exchange rate instead of the freely floating one. Based on the calculation of the currency exchange rate by comparing
Keyword: exchange rate, exchange market pressure, intervention