Judul: Adsorpsi Timbal dengan Hibrida Merkapto-Silika dari Abu Jerami Padi
Abstrak: Silica gel is an adsorbent mostly used to adsorb heavy metals. Raw material for preparing silica gel is silicate (SiO2). Rice straw ash contains 94.5% Si, so that it is potential to be synthesized to silica gel. The weakness of silica gel as adsorbent is its low effectiveness toward metals adsorption, therefore active groups are needed to enhance its effectiveness. Silica gel mercapto-silica hybrid was made by adding HCl 3M to the mixture of 3-(trimethoxylil)-1-propanethiol (TMSP) and Na2SiO3 solution obtained from rice straw ash fused using NaOH until pH 7. The results were characterized using fourier transform infrared spectroscopy (FTIR), X-ray diffraction, energy dispersive x-ray (EDX), and scanning electron microscope. FTIR analysis showed that there were functional group of –CH2 on the silica gel TMSP but the expected –SH group was not detected. However, EDX result showed there was a composition of sulfur compound on silica gel TMSP. The modified silica gel with TMSP enhanced the capacity of Pb(II) adsorption. Commercial silica gel, the synthesized silica gel, and silica gel TMSP were all following Langmuir isotherm.
Keyword: rice straw ash, Pb adsorption, mercapto-silica hybrid

Judul: Sintesis Material Silika Mcm-41 Serta Aplikasinya Sebagai Penjerap Logam Pb(II)
Abstrak: Timbal (Pb) merupakan salah satu logam berat yang berbahaya bagi lingkungan. Metode yang paling sering digunakan untuk mengurangi polutan Pb adalah penjerapan menggunakan adsorben. Tujuan penelitian ini adalah menyintesis adsorben berbasis material silika MCM-41 dan NH2-MCM-41 serta menguji aplikasinya sebagai penjerap Pb(II). Sintesis MCM-41 dilakukan dengan metode Stöber dan difungsionalisasi dengan gugus amina menggunakan metode kokondensasi. Hasil analisis difraktogram sinar-X mengindikasikan material MCM- 41 telah berhasil disintesis. Hasil mikroskop elektron pemayaran menunjukkan distribusi ukuran partikel yang masih cukup lebar dengan rentang skala mikrometer. Spektrum inframerah menunjukkan bahwa proses modifikasi dengan gugus amina pada dinding silika MCM-41 belum berhasil dilakukan. Kondisi terbaik untuk menjerap ion logam Pb(II) adalah dengan menggunakan bobot penjerap 0.05 g dan waktu kontak selama 120 menit. Pola penjerapan Pb(II) menggunakan MCM-41 mengikuti model isoterm Langmuir.
Keyword: adsorpsi, MCM-41, NH2-MCM-41, Pb(II)

Judul: Pengukuran Jantung Kelinci New Zealand White (Oryctolagus cuniculus) dengan Radiografi Toraks
Abstrak: This research was conducted to evaluate radiographs heart size of anaesthetized New Zealand White rabbits (Oryctolagus cuniculus) under different combination of ketamine and xylazine. The rabbits were divided into three groups. Group A were anaesthetized using a 35 mg/kg and 5 mg/kg combination of ketamine and xylazine (n=5). Group B were anaesthetized using a 40 mg/kg and 5 mg/kg combination of ketamine and xylazine (n=3) while group C were anaesthetized using 45 mg/kg and 5 mg/kg combination of ketamine and xylazine (n=3). Parameter of observation from left laterolateral view were: 1) the apicobasilar length of the heart (AB), 2) the width of the heart (CD), 3) the distance between the cranial edge of the fifth rib and the caudal edge of the seventh rib perpendicular to the spine (R5-7), and 4) the vertical depth of the toraks (H). Parameter of observation from dorsoventral view were: 1) the length of the heart (L), 2) the width of the heart (W), and 3) the width of the thorax (T). The result from the heart parameters observation that were measured in left laterolateral view and dorsoventral view shows theres no significantly differ among the groups (P > 0.05). The vertebrae heart size (VHS) values obtained from the sum of the length of the long and the short axes on left laterolateral view. The long axes mean values (A) were 4.35±0.26 v and the short axes mean values (B) were 3.59±0.30 v, therefore VHS mean values were 7.94±0.49 v. On the dorsoventral view, the length of the heart mean values (L) were 4.32±0.29 cm, the width of the heart mean values (W) were 3.33±0.26 cm, and the width of the thorax mean values (T) were 5.85±0.30 cm. In normal conditions, the width of the heart should be less than two-thirds the width of the thorax and values obtained of 3.33<3.72 it shows that the heart is in the normal range. The best ratio to calculated the normal heart dimension in the left laterolateral view was compared the long axes with the vertical depth of the thorax, whereas in dorsoventral view, the length of the heart was compared with the width of the heart.
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