Optimization of the MCM-48 Synthesis Method as a Catalyst in the Esterification of Nyamplung Seed Oil into Biodiesel

This study was conducted to synthesize MCM-48 based on the surfactants (cetyltrimethylammonium bromide (CTAB) and Triton X-100). The effect of surfactant on MCM-48 was studied in the esterification of Nyamplung seed oil. Optimization of the amount of surfactant in the MCM-48 catalyst in the esterification of Nyamplung seed oil was carried out by washing and calcination methods. Comparison of GC-MS method and acid-base titration was also studied to determine the activity of the MCM-48 catalyst in the esterification. The results of the Mann-Whitney statistical test showed that there was no significant difference (Asymp. Sig. (2-tailed) = 0.967) for the two methods. The effect of the active site on the MCM-48 catalyst activity in the esterification was characterized by FTIR and XRD. The catalyst's activity is significantly influenced by both the percentage transmittance of the silanol active site and the surfactant removal method. The MCM-48 catalyst manufactured by calcination (CTAB-MCM-48/650) performed 12.31% better than the washing approach (CTAB-MCM-48/1w). However, the CTAB-MCM-48 catalyst can be applied to the simultaneous reaction (esterification and transesterification) of the conversion of Nyamplung seed oil into biodiesel

Imaging Breast Microcalcifications Using Dark-Field Signal in Propagation-Based Phase-Contrast Tomography

Breast microcalcifications are an important primary radiological indicator of breast cancer. However, microcalcification classification and diagnosis may be still challenging for radiologists due to limitations of the standard 2D mammography technique, including spatial and contrast resolution. In this study, we propose an approach to improve the detection of microcalcifications in propagation-based phase-contrast X-ray computed tomography of breast tissues. Five fresh mastectomies containing microcalcifications were scanned at different X-ray energies and radiation doses using synchrotron radiation. Both bright-field (i.e. conventional phase-retrieved images) and dark-field images were extracted from the same data sets using different image processing methods. A quantitative analysis was performed in terms of visibility and contrast-to-noise ratio of microcalcifications. The results show that while the signal-to-noise and the contrast-to-noise ratios are lower, the visibility of the microcalcifications is more than two times higher in the dark-field images compared to the bright-field images. Dark-field images have also provided more accurate information about the size and shape of the microcalcifications

PEMANFAATAN AMPAS SAGU SEBAGAI BIOSORBEN ION Cd(II),Cu(II) Ni(II) dan Cr(VI)

ABSTRAK TEKNOSAINS 2009Keberadaan ion-ion logam berat seperti Cd(II),Ni(II) dan Cr(VI) dalam lingkungan perairan dapat menimbulkan gangguan kesehatan pada manusia. Untuk itu upaya penghilangan ion-ion tersebut perlu dilakukan. Biosorpsi yang menggunakan biomaterial merupakan metode alternative yang menjanjikan terutama dalam hal efektivitas dan biaya yang diperlukan untuk penyiapan biosorbennya. Berbagai biosorben dapat digunakan termasuk limbah industry.Dalam penelitian ini,penghilangan ion-ion logam tersebut diuji dengan menggunakan limbah yang diperoleh dari industry pembuatan sagu. Tujuan dari penelitian ini adalah untuk menentukan kondisi optimum (waktu dan PH larutan) dari biosorpsi ion-ion logam,menentukan orde dan tetapan laju biosorpsi,mengetahui kemampuan ampas sagu dalam mengadsorpsi ion-ion Cd(II),Cu(II),Ni(II) dan Cr(VI) dari dalam larutannya,dan gugus fungsi yang terlibat dalam biosorpsi ion-ion oleh ampas sagu.Hasil menunjukkan bahwa waktu optimum biosorpsi ion Cd(II),Cu(II),Ni(II)dan Cr(VI) berturut-turut adalah 20,10,15,dan 120 menit.Biosorpsi keempat ion logam oleh ampas sagu memenuhi kinetika orde dua semu dengan tetapan laju (k2)berturut-turut 0,24;5,16;0,56;dan 0,05 g menit-1mg-1 Untuk ion Cd(II),C(II),Ni(II),dan Cr(VI) PH optimum biosorpsi ion-ion tersebut adalah 5 untuk Cd(II) dan Ni(II)4,untuk Cu(II)dan 2 untuk Cr(VI) Biosorpsi keempat ion tersebut memenuhi isothermal langmiur dengan kapasitas biosorpsi 11,79;10,92;11,01 dan 3,05 mg/g berturut-turut untuk ion-ion Cd(II),Cu(II),Ni(II) dan Cr(VI).Berdasarkan data FTIR,gugus fungsi yang terlibat dalam interaksi ini adalah gugus hidroksil.Agen pendesorpsi adalah HN03 0,1 M untuk ion Cd(II),H2S04 0,1 M untuk ion Cu(II),EDTA untuk ion Ni(II),dan NaHC03 untuk ion Cr(VI).Biosorpsi ion-ion logam dari larutan yang mengandung campuran keempat ion logam dapat dilakukan dengan ampas sagu

Kinetics and Adsorption of Molecularly Imprinted Polymers Dibutylphthalate

Molecularly Imprinted Polymers (MIP) are polymers with active sites that can recognize target molecules selectively. This study aims to determine the kinetics and adsorption capacity of MIP_DBP. The method used in the synthesis of MIP_DBP was precipitation polymerization using methacrylic acid (MAA) monomer, Ethyleneglycol Dimethacrylate (EGDMA) cross linker, DBP as a template molecule, and toluene as a solvent. The MIP_DBP obtained is a white solid. The results of the MIP_DBP adsorption kinetics test followed the pseudo-second-order kinetics model and the adsorption capacity according to the Freundlich isothermal adsorption model with the adsorption capacity value for DBP was 9.38 mg/g

Pengaruh pH dan Waktu Terhadap Kemampuan Adsorpsi Mip_TFMAA-co-Egdma

A molecularly imprinted polymers (MIP) can be synthesized using functional monomers and template molecules through polymerization with the aid of cross linker. In previous studies, MIP_TFMAA-co-EGDMA was synthesized using the main ingredient tryfluoromethylacrylic acid (TFMAA) as functional monomer, b-sitosterol as a template molecule and ethyleneglycol dimethacrylate (EGDMA) as cross linker. The ability of adsorption against the effects of pH and contact Time of MIP has been evaluated. Variations of pH standard solution b-sitosterol were 4, 5, 6, and 7, while the time variation used were 30, 60, 90, and 120 minutes. The data of b- sitosterol concentrations adsorbed by MIP_TFMAA-co-EGDMA because of the influence of pH and contact times were analyzed using high pressure liquid  chromatography (HPLC). pH5 gives the most influence on the adsorption capacity MIP_TFMAA-co-EGDMA against b-sitosterol. The number of b-sitosterol adsorbed on the pH was 1.0265 mg/g, while at 90 minutes was the best time for the MIP b- sitosterol adsorb as much as 1.3486 mg/g. Based on the adsorption kinetics study, the adsorption ability MIP_TFMAA-co-EGDMA against b-sitosterol in accordance with the pseudo second order kinetic model