Judul: Penentuan Tahanan Nanofiltrasi Menggunakan Model Tahanan Seri Pada Pemisahan Beta-Karoten dan Alfa-Tokoferol Minyak Sawit Dalam Isopronal
Abstrak: Palm oil contains high concentration of carotenoids anf tochoperols that can be recoveredby adsorption using attapulgite and desorption in isopropanol and then applying membrane technology to separate the beta-carotene and alpha-condition of nanofiltration and to obtain resistance of membranes using the series resistance model. titania membraneswith different pore diameters (5 and 10 nm) were used to conduct the study on nanofiltration membranes. Applied pressure was range from 1.5 to 2.5 bar and crossflow velocity was range from 0.14 to 0.97 m s-1. It was found that membrane 5 nm had optimum transmembrane pressure at 2 bar and feed flow velocity at 0.42 m s-1 with permeate flux 0.96 L m-2 h-1. On n the other side, membrane 10 nm had optimum transmembrane pressure at 2.2 bar and feed flow velocity at 0.69 m -1' with permeate flux 2.4 L m-2 h-1 . The intrinsic membrane resistances, Rm, the total membrane resistances, R'm, and the fouling T esistances, Rf, of membrane 5 nm were 0.25, 2.08 and 1.29 bar m2 h -1, respectively, with the resistance index, Ø, was 1.04 m2 h -1. On the other side, membrane 10 nm had Rm, R'm and Rf 0.78, 0.49 and 0.24 bar m2 h L-1, respectively, with 0 was 0.42 m2 h L-I. The conclusion of this research is nofiltration 5 and 10 nm are ineffective to separate beta-carotene and alpha- tocopherol in isopropanol because permeate flux and rejection are very low with resistances of membranes and resistance index are very high. So that to increase V g gg the permeate flux and rejection needed study about usage of different membrane and solvent type, conditioning of feed and controlling of aggregate alpha- tocopherol in isopropanol.
Keyword: Nanofiltration, Series resistance, Beta-carotene, Alpha-tocopherol, Isopropanol, Vitamin E, Reologi, Membran, Model tahanan seri, Nilai tahanan foulig (Rf), Nilai indeks polarisasi konsentrasi, Pengaruh laju air umpan terhadap Flulig

Judul: The Effect of Pressure Variations on the Application of Nanofiltration Membranes in Aquaculture Recirculating Systems
Abstrak: Penggunaan membran nanofiltrasi dengan pengoperasian jangka panjang sebagai unit pengolahan menimbulkan fouling yang tak terhindarkan akibat adanya proses polarisasi konsentrasi pada permukaan membran. Konsentrasi terpolarisasi dan kenaikan tekanan osmotik juga penyebab penurunan fluks permeate. Penelitian bertujuan menganalisis pengaruh tekanan yang diterapkan pada sistem resirkulasi akuakultur dengan teknologi membran nanofiltrasi terhadap konsentrasi kontaminan permeate. Penelitian ini dilakukan pada bulan Maret – Juli 2023 yang berlokasi di Laboratorium Terpadu Departemen Teknik Sipil dan Lingkungan, Fakultas Teknologi Pertanian, Institut Pertanian Bogor. Penelitian ini menggunakan tiga variasi tekanan yang berbeda yakni tekanan 5, 6, dan 7 bar. Variasi 7 bar memiliki nilai efisiensi penolakan kontaminan amonia dan nitrit sebesar 100%. Pemodelan dilakukan untuk estimasi konsentrasi kontaminan nitrit di permeate membran nanofiltrasi. Hasil uji validasi dengan regresi linear menunjukkan pengembangan pemodelan sangat baik dalam mengestimasi konsentrasi kontaminan permeate membran nanofiltrasi karena memiliki indikator nilai R square mendekati satu., The use of nanofiltration membranes with long-term operation as a treatment unit causes unavoidable fouling due to the concentration polarization process on the surface of the membrane. Polarized concentrations and increased osmotic pressure also cause a decrease in permeate flux. The aim of this study was to analyze the effect of pressure applied to the aquaculture recirculating system with nanofiltration membrane technology on the concentration of permeate contaminants. This research was conducted in March – July 2023 located at the Integrated Laboratory of the Department of Civil and Environmental Engineering, Faculty of Agricultural Technology, Bogor Agricultural University. This study used three different pressure variations, namely 5, 6, and 7 bar. The 7 bar variation has an efficiency value of 100% for rejecting ammonia and nitrite contaminants. Modeling was performed to estimate the concentration of nitrite contaminants in the permeate nanofiltration membrane. The results of the validation test with linear regression showed that the development of modeling was very good in estimating nanofiltration membrane permeate contaminant concentrations because it had an indicator value of R square close to one.
Keyword: estimasi konsetrasi, fluks, membran nanofiltrasi, tekanan

Judul: Keanekaragaman Burung di Jalur Pendakian Cemoro Sewu Gunung Lawu.
Abstrak: Gunung Lawu adalah gunung di Pulau Jawa yang memiliki potensi burung berbeda pada setiap ketinggian. Adanya aktivitas wisata alam di Gunung Lawu dapat berpengaruh terhadap keberadaan burung. Penelitian ini bertujuan untuk mengidentifikasi jenis-jenis burung, mengidentifikasi respons komunitas burung terhadap aktivitas manusia berdasarkan jarak dari jalur pendakian dan menghitung keanekaragaman jenis burung berdasarkan perbedaan ketinggian. Penelitian dilaksanakan di jalur pendakian Cemoro Sewu Gunung Lawu pada Mei–Juni 2018. Metode yang digunakan adalah metode titik hitung. Hasil penelitian menunjukkan total jumlah jenis burung yang ditemukan adalah 24 jenis dari 16 famili. Terdapat variasi nilai keanekaragaman berdasarkan jarak dari jalur pendakian dan perbedaan ketinggian tempat. Keanekaragaman tertinggi berdasarkan jarak dari jalur pendakian terdapat di zona paling dekat dengan jalur pendakian (H’=2,13). Keanekaragaman tertinggi berdasarkan perbedaan ketinggian terdapat di ketinggian 1900 mdpl (H’=1,94). Penelitian ini menduga bahwa komunitas burung tidak terganggu oleh adanya aktivitas manusia di jalur pendakian.
Keyword: burung, keanekaragaman, aktivitas manusia, ketinggian tempat