Judul: Efek Inflasi Dan Nilai Tukar Terhadap Preferensi Memegang Uang Fiat atau Uang Berbasis Logam Mulia: Studi Eksperimental
Abstrak: Penurunan nilai rupiah ini disebabkan oleh menguatnya Dollar Amerika Serikat (AS), kondisi perekonomian global yang memanas akibat adanya perang dagang AS dan China dan kenaikan Federal Funds Rate yang menyebabkan Indonesia mengalami dampak dari fenomena tersebut, salah satu dampaknya adalah melemahnya nilai tukar rupiah terhadap dollar, hal tersebut menandakan nilai tukar Indonesia masih sangat dipengaruhi oleh kondisi eksternal. Sehingga dollar dinilai lebih menguntungkan daripada rupiah. Penelitian ini menggunakan metode eksperimental dengan regresi logistik, menggunakan SPSS yang bertujuan melihat preferensi individu terhadap pilihan jenis uang jika dihadapkan dengan informasi-informasi, hasil penelitian menunjukkan bahwa informasi inflasi dan nilai tukar dapat mempengaruhi pilihan jenis uang yang akan digunakan individu. Lalu untuk variabel karakteristik yang berpengaruh terhadap pilihan jenis uang didominasi oleh variabel usia, pendapatan dan universitas.
Keyword: Eksperimental, Fluktuasi, Nilai tukar, Preferensi, SPSS

Judul: Preferensi Penggunaan Uang Fiat Dibandingkan Uang Berbasis Logam Mulia (Studi Eksperimen Berdasarkan Motif Transaksi, Berjagajaga dan Spekulasi).
Abstrak: Penelitian ini berupaya memberikan opsi lain bagi instrumen pembayaran di Indonesia berupa uang berbasis logam mulia, yaitu uang yang memiliki nilai intrinsik karena mengandung beberapa gram emas sesuai dengan nominal uang. Untuk mengetahui sejauh mana uang berbasis logam mulia dapat diterima oleh masyarakat, maka akan diteliti preferensi penggunaan uang fiat dibandingkan uang berbasis logam mulia serta faktor yang memengaruhinya. Metode analisis yang digunakan adalah analisis deskriptif dan regresi logistik dengan pendekatan eksperimental ekonomi. Hasil penelitian menunjukkan bahwa uang berbasis logam mulia lebih banyak dipilih daripada uang fiat (Rupiah dan Dolar) pada motif transaksi dan berjaga-jaga serta motif spekulasi. Secara umum, usia dapat memengaruhi preferensi pada motif transaksi dan berjaga-jaga sedangkan faktor yang memengaruhi preferensi pada motif spekulasi terdiri dari usia, pendapatan dan pilihan menyimpan uang tunai atau di bank.
Keyword: eksperimental ekonomi, preferensi, uang berbasis logam mulia, uang fiat

Judul: Application of phycocyanin from microalgae Spirulina platensis as light harvesting in anatase TiO2 nanoparticle solar cell.
Abstrak: The dye sensitized solar cell (DSSC) has been assemblied used hybrid titanium oxide (TiO2) film/phycocyanin. The TiO2 film was synthesized by sol gel method with titanium chlorida (TiCl4) as precursor by hydrolysis used sulfuric acid (H2SO4). Furthermore, it calcinated for 2,5 hours in variation of annealing temperature (400oC, 600oC, 800oC, dan 1000oC). In XRD patterns exhibited which annealing temperature at 400oC to 800oC were anatase phase all. When annealed at temperature 1000oC, it caused phase transformation from anatase to rutile. The crystals size according to XRD patterns were 13,75 nm, 20,79 nm, 25,25 nm, 48,88 nm and particle size from SEM images were 43,06 nm, 44,91 nm dan 64,99 nm, 80,40 nm, respectively. The crystals and particle size increased with annealing temperature. The film thickness influenced material absorption. The optical measurement of TiO2 film and TiO2/phycocyanin hybrid film used UV-Vis spectrophotometer. Additional phycocyanin caused peak width of absorbed region from ultraviolet to visible region. The band gap energy of TiO2 can be calculated using the cut off wavelength obtained from the absorbance spectrum of a nanoparticles TiO2 films. Based on intersection between linear and energy (hv) axis. In this study just limited for anatase phase. It was caused anatase band gap is wider than rutile phase. That’s meaningful for solar cell application such as dye sensitized solar cell (DSSC). The absorption coefficient average at difference annealing temperature such as at 400oC, 600oC, 800oC were 8,1600x102, 1,7535x103 and 4,0154x102, where α < 104 include to direct transition. Band gap energy 400oC, 600oC, 800oC were 3,79 eV, 3,59 eV, and 3,35 eV, respectively. Based on this result, exhibition that band gap energy of TiO2 semiconductor film decreased with increasing annealing temperature. Spirulina platensis was cultivated in technical modification (Hastuti) with aeration under light intensity about 3000 lux. The cell density (stationer phase) for eighth day which OD value was more than 0,5. It means, the culture can be harvested. In 80 liters Spirulina platensis culture have been produced biomass dry about 10,46 gram and extracted phycocyanin in dry powders was 5,50 gram. The phycocyanin absorption spectrum at the wavelength of 619,36 nm (visible region) which had relaxation energy was 2,945 eV. The emission peak at the wavelength of 708,55 nm with relaxation energy about 2,793 eV. The Stokes shift based on difference energy absorption and emission calculated about 0,152 eV. Both of this showed phycocyanin can absorbed and radiated the sun light which received. This choice characteristic pigment was a good one related to sensitizer in solar cell application. Integration between light harvesting protein and TiO2 semiconductor surface had important role in improving of output as solar cell materials. The presence of carboxylate group (-COOH) made pigment be more efficient was due to anchored to the surface of TiO2 ampoter. The phycocyanin pigment had carboxylate group which reacted with TiO2 surface formed ester. The carboxylate group increased of dye electronics couple from excited state (p anti bonding orbital) to semiconductor acceptor state (TiO2 conduction band). The samples which made based on annealing temperature variation formed be solar cell respectively. Furthermore, cells be assembled for
Keyword: anatase, dye sensitized solar cell, efficiency, gap energy, phycocyanin