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"ABSTRAKDeposit laterit adalah salah satu jenis bijih nikel yang memiliki kandungan nikelterbanyak di bumi. Di dalam lapisan laterit, saprolit memiliki kandungan nikelyang lebih tinggi dibandingkan lapisan lainnya. Saprolite biasanya diproses secarasmelting (pirometalurgi) karena memiliki kandungan magnesium yang tinggi.Penelitian ini bertujuan untuk mengetahui sejauh mana keefektifan proseshidrometalurgi dengan lixiviant amonium bikarbonat terhadap perolehan nikel.Bijih saprolit dikarakerisasi secara EDX dan AAS untuk mengetahui komposisiawal bijih. Saprolit direduksi menggunakan batubara 33.33 % wt pada temperatur1250 oC selama 120 menit. Hasil reduksi pemanggangan kemudian diuji denganXRD. Proses pelindihan agitasi pada bijih saprolit yang direduksi dan bijih yangtidak direduksi dilakukan dengan menggunakan larutan amonium bikarbonat padavariasi konsentrasi yaitu 1 M, 2 M, 3 M, 4 M. Kandungan nikel yang larut dalampregnant leach solutiont dihitung menggunakan Atomic Absorbance Spectroscopy(AAS).Hasil XRD saprolit menunjukkan terjadi transformasi fasa dari goethite dan Fe2O3sebelum reduksi pemanggangan menjadi Fe3O4, NiO dan FeNi setelah reduksipemanggangan Hasil penelitian menunjukan % perolehan Ni semakin meningkatdengan peningkatan konsentrasi amonium bikarbonat. Perolehan nikel tertinggiyang diperoleh adalah 1.61 % pada konsentrasi pada konsentrasi 4 M amoniumbikarbonat.

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AbstractLaterite deposit is a kind of nickel ores that has the greatest of nickel reserves in theworld. In the lateritic layer, saprolite has higher nickel content more than otherlayers. Saprolite is usually process with smelting method (pyrometallurgy)because it has higher magnesium content.The aim of this research is to know the effectiveness of hydrometallurgy processusing ammonium bicarbonate as lixiviant to nickel recovery from saprolite ore.Saprolite was caracterized with Energy Dispersive X-Ray (EDX) and AtomicAbsorbance Spectroscopy (AAS) to determine it?s chemical composition. Floatsinkprocess was apllied to saprolite to separate material based on it?s weigth.Saprolite was reduced at 1250 oC for 120 minutes utilized coal 33.33% wt as areductant, then it was tested with XRD. Agitation leaching process was applied toreduced and unreduced saprolite utilized ammonium bicarbonate solution as lixiviantat various concentration which was 1 M, 2 M, 3 M, 4 M. Nickel content thatdissolved in lixiviant was determined with Atomic Absorbance Spectroscopy(AAS).Result of XRD characterization shows phase transformation in saprolite fromgoethite and Fe2O3 before reduction roasting to Fe3O4, NiO and FeNi afterreduction roasting. The result of research shows that % recovery of Ni is tend toincrease along with the increasing of ammonium bicarbonat concentration. Thehigest nickel recovery in research is 1.61 % at 4 M ammonium bicarbonatconcentration."

"Formulasi serbuk inhalasi rifampisin carrier-free dapat menghantarkan rifampisin dalam jumlah yang adekuat untuk menjamin efektivitas terapi tuberkulosis. Diperlukan serbuk inhalasi rifampisin dengan sifat aerodinamis yang baik agar dapat terdeposisi di paru-paru. Penelitian bertujuan untuk menghasilkan sediaan serbuk inhalasi rifampisin yang memiliki sifat aerdonamis yang baik dengan adanya penambahan l-leusin dan/atau amonium bikarbonat, dengan pelepasan obat yang baik dalam medium makrofag paru. Serbuk inhalasi rifampisin (F1) diformulasikan dengan leusin 30% (F2), amonium bikarbonat 2% (F3) atau kombinasinya (F4) dan dibuat dengan metode semprot kering. Serbuk yang diperoleh kemudian dikarakterisasi rendemen, kandungan lembab, ukuran partikel geometris dan aerodinamis, serta kelarutan dan profil disolusinya dalam medium simulasi cairan paru pH 7,4 dan medium simulasi makrofag paru pH 4,5. Penambahan leusin 30% (F2) berhasil sedikit memperbaiki sifat aerodinamis serbuk inhalasi rifampisin (F1) dengan diameter aerodinamis rata-rata 8,21 μm, FPF 30,73% dan EF 42,60%, serta meningkatkan pelepasan rifampisin dalam medium simulasi makrofag alveolar (pH 4,5) menjadi 13,14 ± 0.08% dengan peningkatan 1,62x dibanding serbuk rifampisin (F1).

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A carrier-free dry powder inhaler of rifampicin formulations could deliver adequate amounts of rifampicin to provide the effectiveness of tuberculosis therapy. Inhaled rifampicin powder with good aerodynamic properties was required to be deposited in the lungs. The aim of the study was to produce a rifampicin inhaled powder that had good aerodynamic properties with the addition of L-leucine and/or ammonium bicarbonate, with good drug release in the medium of lung macrophages. Inhaled rifampicin powder (F1) was formulated with 30% leucine (F2), 2% ammonium bicarbonate (F3), or a combination thereof (F4) and was prepared by spray dry method. The obtained powder was then characterized by yield, moisture content, geometric and aerodynamic particle size, as well as solubility and dissolution profile in lung fluid simulation medium (pH 7.4) and lung macrophage simulation medium (pH 4.5). The addition of 30% leucine (F2) succeeded in slightly improving the aerodynamic properties of the inhaled rifampicin powder (F1) with an average aerodynamic diameter of 8.21 μm, FPF 30.73%, and EF 42.60%, as well as increasing the drug release of rifampicin in the alveolar macrophage simulation medium (pH 4.5) to 13.14 ± 0.08% with an increase of 1.62x compared to rifampicin powder (F1)."