Sintesis dan Karakterisasi Enkapsulat Katalis Nikel (II) pada Silika Mesopori Modifikasi

Ni(II)-BF3/MCM-41 was synthesized for heterogeneous catalyst. The boron trifluoride modified mesoporous silica BF3/MCM-41 was studied to investigate its ability as supporting agent in heterogeneous catalysis system. For this purpose, the structural directing agent remaining in as-synthesis MCM-41 removed by solvent extraction. Surface modification of mesoporous silica MCM-41 with aniline and boron trifluoride was carried out. Then, the surface of boron trifluoride modified mesoporous silica was subjected to an encapsulation with Ni(II) ions. These solid materials were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and atomic absorption spectroscopy (AAS). In the FTIR spectra of the modified silica mesoporous, the presence of vibration band >Si-O-B confirm the success of modification of support. While, the shifting of the vibration band >Si-O-Si< is considered an indication of the proof of Ni(II) species onto the modified mesoporous silica. From the SEM photograph, it can be seen that the morphology of the Ni(II)-BF3/MCM-41 tend to form aggregates of smaller particles. Based on measurement of metal content by AAS, it was known that the value of metal loading is 33%. While for the leaching test, Ni(II)-BF3/MCM-41 lost only 0.014 % of Ni metal. It indicates the stability of the interaction between the N(II) and support of the modified mesoporous silica

STRATEGI KOMUNIKASI ANTARBUDAYA DALAM MENGURANGI STEREOTIPE NEGATIF TERHADAP SUKU BATAK DI RUSUNAWA KEUDAH, BANDA ACEH

ABSTRAKCangkang pala (Myristica fragrans) merupakan salah satu limbah yang diolah menjadi adsorben logam berat. Pada penelitian ini cangkang pala yang digunakan sebagai adsorben Cr (II) telah diaktivasi dengan larutan ZnCl2 1 M pada beberapa variasi waktu aktivasi. Adsorpsi ion logam krom (Cr (NO3)2) oleh arang aktif berlangsung cukup baik pada semua kondisi. Pada waktu pembakaran 2 jam, serapan minimum sebesar 98,90% terjadi pada waktu aktivasi menit ke-60 dengan waktu kontak 90 menit dan serapan terbaik terjadi pada pada waktu aktivasi 15 menit dengan waktu kontak 45 menit, dimana serapan ion logam krom (Cr (NO3)2) mencapai 100%. Sementara itu pada pembakaran 4 jam, serapan minimum sebesar 98,79% terjadi pada waktu aktivasi 30 menit dengan waktu kontak 45 menit dan serapan terbaik terjadi pada pada waktu aktivasi 30 menit dengan waktu kontak 90 menit, dimana serapan ion logam krom (Cr (NO3)2) mencapai 100%. Proses adsorpsi ion logam krom (Cr (NO3)2) sudah dapat berlangsung secara efektif pada pembakaran arang selama 2 jam. Kata Kunci: Logam berat, Myristica fragrans, Uji adsorpsiABSTRACTShell of nutmeg (Myristica fragrans) is one of the waste that is processed into heavy metal adsorbent. In this study, nutmeg shells used as adsorbent of Cr (II) has been activated with a solution of 1 M ZnCl2 activation time in several variations. Adsorption of metal ions chromium (Cr (NO3)2) by activated charcoal lasted quite well in all conditions. At the time of the burning of 2 hours, a minimum of 98.90% uptake occurs at the time of activation of the 60th minute with a contact time of 90 minutes and the best absorption occurs at the activation time of 15 minutes with a contact time of 45 minutes, where the uptake of metal ions chromium (Cr (NO3)2) to reach 100%. Mean while, the burning of 4 hours, a minimum of 98.79% uptake occurs at activation time 30 minutes with a 45 minute contact time and the best absorption occurs at the activation time of 30 minutes with a contact time of 90 minutes, where the uptake of metal ions chromium (Cr (NO3)2) reaches 100%. The process of adsorption of metal ions chromium (Cr (NO3)2) was able to take place effectively at burning charcoal for 2 hours. Keywords: Heavy metals, Myristica fragrans, adsorptio

Pengaruh Modifikasi Fisika pada Komposisi, Struktur Kristal dan Sifat Katalitik Lempung Solok

Mineral lempung yang diperoleh dari Kabupaten Solok, Sumatera Barat, telah dimodifikasi secara fisika melalui pemanasan pada 105°C, 450°C dan 850°C. Aktivitas katalitiknya telah diuji dalam transesterifikasi minyak jelantah untuk menghasilkan metil ester asam lemak. Komposisi utama lempung ditemukan terdiri dari Si, Al dan Fe serta unsur-unsur minor lainnya seperti K, Ti, Na, Ca Mg, dan Mn (pengukuran XRF). Jenis mineral utama sampel lempung adalah kaolinite dan illite (karakterisasi XRD). Kalsinasi pada suhu 850 °C mengakibatkan penurunan fasa kaolinit yang menandakan telah terjadi transformasi parsial menjadi metakaolin (analisis XRD). Pengujian aktivitas katalitik di bawah kondisi reaksi tertentu dari semua lempung menunjukkan bahwa lempung yang dikalsinasi pada 850°C menghasilkan dua jenis senyawa biodiesel yaitu metil ester asam palmitat dan metil ester asam oleat (analisis GC-MS). Tanah liat yang dipanaskan pada suhu 110 dan 450 oC sama sekali tidak menunjukkan aktivitas kataliti

The Classification of Diffeomorphism Classes of Real Bott Manifolds

A real Bott manifold (RBM) is obtained as the orbit space of the n-torus T^n by a free action of an elementary abelian 2-group ZZ_2^n. This paper deals with the classification of some particular types of RBMs of dimension n, so that we know the number of diffeomorphism classes in such RBMs

Stability of Smoker Population Model

— In this article, a model for the smoking habits distribution is studied. The distribution model of smoking habits is divided into three compartments, namely potential smokers (P), active smokers (S), and permanent non-smokers (R). Based on the model analysis, two equilibrium points are obtained, they are the smoke-free equilibrium point and the endemic equilibrium point. Analytical study is carried out by analyzing the stability of the model around the equilibrium point based on the eigen values of the Jacobian matrix. The stability of the model is also associated with the basic reproduction number (Ro) or the parameter that determines the population is free from active smokers or the prevalence of smoking habits occurs. The numerical simulations performed show asymptotically stable smoking population around the smoker-free equilibrium point with  Ro1