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"There is an abundant source of naturally occurring mordenitein the Bayah region of Indonesia. In this work we studied how acid dealumination of this indigenous zeolite affected its physical, chemical and catalytic properties. The results are compared to those obtained with another natural mordenite and a commercially available synthetic mordenite. Acid dealumination of mordenites is known to affect the pore structure and therefore enhance the adsorption-properties of the zeolite and the accessibility to its acidic sites. A series of dealuminated mordenite samples were prepared. They were refluxed in constant boiling HCl as a function of time. The samples were each subsequently exchanged with IN ammonium nitrate. The Si/Al ratio was determined by X-Ray Fluorescence. The presence of other metals was detected with Atomic Adsorption Spectroscopy and Inductively Coupled Plasma Spectroscopy. Nitrogen Adsorption was used to determine the surface area and the pore size distribution. Crystallinity and unit cell size were determined via X-Ray Diffraction. The surface morphology was probed with Scanning Electron Microscopy. An n-hexane cracking test was utilized to probe catalytic activity and selectivity. The results of this study indicate that up to and including sixteen hours of reflux, dealumination of this natural Indonesian mordenite increases the crystallinity and the average pore size, however the surface area and the unit cell size remain constant. Additional reflux, beyond sixteen hours, destroyed a portion 'of the zeolitic framework, indicated by a loss in crystallinity. Cracking activity increased through sixteen hours .of ref lux and was found to be constant thereafter. Total' C2, C3 and C4 {including isobutene) selectivity improved through sixteen hours of reflux and then also remained constant. In comparison to a commercially available sample of synthetic mordenite, the modified Indonesian mordenite ,is less active, but has comparable selectivity. However, compared to the naturally occuring U.S. mordenite, the modified Indonesian mordenite has improved physical and catalytic properties."

"Among semiconductors, zinc oxide (ZnO) has received great attention due to its wide band-gap and high electron mobility, resulting in various strategic applications. Controlling the physical properties of ZnO is therefore a critical issue in the fabrication of related electronic and optical devices. In this study, ZnO nanorods layers were grown on an ITO glass substrate via chemical bath deposition at low temperature. Prior to the growing process, the layers were deposited using a spin-coating technique. The seeding solution was made by dissolving zinc nitrate tetrahydrate and hexamethylene tetraamine in cold water (0oC) for an hour using a cooler bath. The as-synthesized ZnOs were further subjected to different post-hydrothermal treatment series at a temperature of 150oC for three hours at atmospheric pressure and at 100°C for one hour under one bar of nitrogen gas (N2) pressure. The characterization was performed using scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and UV-Vis spectroscopy. The SEM results showed that the ZnO nanorods were grown as a vertically aligned hexagonal structure, while the XRD patterns showed a high intensity at the (002) plane. On the basis of investigation, it was found that under post-hydrothermal treatment at 150oC for three hours with atmospheric pressure, the synthesis procedure resulted in nanostructures in the form of ZnO rods. Meanwhile, post-hydrothermal treatment at 100°C for one hour under one bar of nitrogen gas (N2) produced ZnO rods and tubes. In general, the post-hydrothermal process provided a high degree of crystallinity. The optimum ZnO layer was obtained after post-hydrothermal treatment at 150oC for three hours at atmospheric pressure, with a crystallite size and band-gap energy of ~18 nm and 3.20 eV, respectively."

"Penelitian telah dilakukan di Teluk Jakarta mengenai pemodelan hubungan antara struktur komunitas mangrove dengan stok karbon dan kondisi fisika kimia perairan. Penelitian ini bertujuan untuk mendesain pola hubungan yang terjadi antara struktur komunitas mangrove dengan stok karbon dan kondisi fisika kimia perairan di Teluk Jakarta. Desain model didapatkan setelah melalui serangkaian penelitian lapangan di Teluk Jakarta yang berada di Tangerang-Jakarta Utara-Bekasi, sehingga didapatkan data primer dan sekunder. Pembuatan model ini menggunakan pemodelan system dynamic dengan software powersim studio 10 kemudian dilakukan simulasinya. Hasilnya adalah hubungan antara struktur komunitas mangrove dengan stok karbon dan kondisi fisika kimia perairan mengalami pertumbuhan yang lambat. Hutan mangrove yang terletak di pesisir Teluk Jakarta telah mengalami suksesi dan seleksi alam sehingga terjadi dominansi dari spesies Avicennia marina, A.Lanata, Rhizophora aviculata, R.Mucronata, Soneratia caseolaris, S.Alba. Rata-rata Indeks Nilai Penting (INP) hutan mangrove ini adalah rendah yaitu untuk tingkat pohon sebesar 113,57%, tingkat anakan 92,93%, dan tingkat semai 80,60%. Rendahnya INP ini menyebabkan kandungan stok karbon rendah yaitu 10,214 t.C/ha (hubungan positif). Hasil pemodelan memperlihatkan daya ungkit dari permasalahan ini adalah debit air sungai (207,775 m³/detik/hari), dan arus laut pantai (0,04 m/detik). Kedua parameter ini menyebabkan perubahan secara signifikan pada parameter lain yaitu parameter salinitas, oksigen terlarut, logam berat, dan kecerahan yang berpengaruh pada pertumbuhan dan kehadiran spesies mangrove. Semakin besar debit air dan semakin kecil arus air laut, maka semakin lambat pertumbuhannya. Oleh karena itu perbaikan dalam pengelolaan hutan mangrove pada daerah terganggu seperti ini perlu dilakukan dengan memfokuskan pada perbaikan daya ungkitnya, sehingga efisiensi dan efektifitas dalam pengelolaan hutan mangrove dapat dilakukan. Harapan dari hasil penelitian ini adalah agar ekosistem hutan mangrove yang berada didaerah terganggu dapat terselamatkan.

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Research has been carried out at Jakarta Bay regarding of the relationship between mangrove community structure and carbon stocks and physical chemical condition of marine water. This study aims to design the pattern of relationships that occured between the structure of mangroves community, carbon stocks, and the physical chemical conditions of the coastal marine waters in Jakarta Bay. The model design was obtained after going through a series of field studies in Jakarta Bay located in Tangerang-North Jakarta-Bekasi, so the primary and secondary data were obtained. Designed this model by system dynamic modeling using software powersim studio 10 then simulating. The result was obtained relationship between the structure of magrove community, C-stocks, and physical chemical conditions experience in slow growth. Mangrove forest in Jakarta Bay beach has experienced in succession and natural selection so the dominance species has overdue such as Avicennia marina, A.Lanata, Rhizophora aviculata, R.Mucronata, Soneratia caseolaris, S.Alba. Average of important value index (IVI) was low, in tree level 113,57%, sapling level 92,93%, seedling level 80,60%. The low of IVI caused the low of C-stocks 10,214 t.C/ha (positif relationship).

The result of modeling showed leverage of this problem are water river discharge (207,775 m³/s) and ocean current 0,04 m/s. This two parameters caused significant changed on other parameters such as salinity, disolved oxygen, heavy metal, and brightness which had influencing of growth and presence (frequency) of species. The higher of water river discharge and the less of ocean current made the slowest growth of mangroves. This made sense to repairing of mangrove forest management in disturbing area to focus on the leverage so would be efective and effisience. Hope this research result would be part of problem solving  in mangrove forest which had led in disturbing area."