In this study, a simple method to obtain silica from corncob ash has been investigated using a nonthermal and thermal method. The Nonthermal method was done by various acid treatment with HCl, HBr and citric acid at room temperature. Thermal method was performed for HCl-leached, HBr-leached, and citric acid-leached corncob in the furnace at 750 ºC for 5 hours. Corncob ash was characterized by Energy Dispersive X-ray fluorescence spectroscopy (EDXRF), Fourier transforms infrared spectroscopy (FTIR), X-Ray diffraction (XRD), and Scanning electron microscope-electron dispersive X-ray (SEM-EDX). In this study silica content increase after acid treatment (leaching) and combustion at high temperatures. The result established that silica is most obtained with HCl treatment that is equal to 79,95% with lower metallic oxide impurity content. The FTIR spectra with different intensity shows silanol group at 1636 -1641 cm -1 , whereas siloxane group at 1037 -1106 cm , and 459-469 cm -1 . X-Ray diffractogram shows silica transition pf amorphous (2θ = 21 -25º) to quartz crystalline (2θ = 26.66º) phase. The surface morphology of silica that characterized with SEM-EDX shows amorphous and crystalline silica corresponds to XRD result. The high intensity spectra of Si and O in EDX shows the presence of silica in corncob ash.

Study of Dynamics of Phosphate in the Water Quality in Bogor of Upstream Ciliwung River ABSTRAKSungai Ciliwung telah ada dan menjadi bagian penting masyarakat sejak zaman purba. Namun seiring dengan berlalunya waktu dan perkembangan pesat, sejak tahun 2009 Sungai Ciliwung telah tercemar dari hulu. Salah satu polutan yang bisa menurunkan kualitas air sungai adalah fosfat. Keberadaan fosfat yang berlebihan di badan air dapat menyebabkan kondisi pengayaan nutrisi (eutrofikasi), dan dengan dukungan nitrat dapat menyebabkan algae blooming yang menjadi salah satu masalah lingkungan. Penelitian ini dilakukan untuk mengetahui dinamika senyawa fosfat Sungai Ciliwung apakah pencemarannya berkurang, sama, atau lebih buruk. Ruang lingkup penelitian meliputi pengambilan sampel air sungai pada tiga titik Katulampa, Pasar Bogor, dan Warung Jambu dengan interval waktu sampling 8 jam dalam sehari, dan dilakukan setiap minggu selama 3 minggu berturut-turut. Kemudian dilakukan analisis sampel di laboratorium, serta interpretasi data dengan membandingkan hasilnya terhadap PP No.82 tahun 2001. Nilai total fosfat di air sungai Ciliwung Hulu tidak memenuhi standar kualitas lingkungan PP. 82 tahun 2001, dan diindikasikan berada dalam kondisi eutrofikasi.

Characteristics  Of Arabica Ground Coffee (Coffea arabica L) Fermented by Saccharomyces cerevisiae Coffee is one of the plantation commodities that have higher economic value among other plantation crops. Arabica coffee has superior quality and taste compared to others. Coffee has been widely processed into grounded coffee products. The quality of ground coffee is influenced by many factors; one of them is processing. In the processing of coffee fruit into coffee beans the process that is certain to occur is fermentation. Fermentation affects ground coffee quality products. This study focused on observing the quality of arabica ground coffee fermented by Saccharomyces cerevisiae. The quality parameters of the ground coffee observed include water content, coffee extract and caffeine content. Other qualities supporting parameters are pH of ground coffee and phytochemical test. In addition, the fermentation pH was also observed in the fermentation process, reducing sugar content and qualitative testing of ethanol. Saccharomyces cerevisiae concentration was varied 0% (K0), 1% (K1), 2% (K2), 3% (K3) and 4% (K4) with duration of fermentation is  for 24 hours. The quality of arabica ground coffee products is in accordance with SNI Ground Coffee 01-3542-2004 with the following values: Water content 2,3-1,6% b/b. Coffee extract 30,7-30,3% b/b. Caffeine content 1,18-1,01% b/b. The pH of brewed ground coffee is 6,5-5,1. Alkaloids, saponins and tannins were detected in all different treatments of ground coffee samples. Flavonoids were only detected in the treatment of K0 ground coffee samples. The fermentation pH at the initial state was 5,61 and after fermentation was 4,91-3,89. Reducing sugar content at the initial state was 32,35% b/b and after fermentation 21,2-4,3% b/b. Ethanol was detected in all samples before and after fermentation.Keywords: Coffea Arabica L, Ground Coffee Quality, Fermentation, Saccharomyces cerevisiae ABSTRAK Kopi merupakan salah satu komoditi perkebunan yang memiliki nilai ekonomis yang cukup tinggi diantara tanaman perkebunan lainnya. Kopi Arabika memiliki karakteristik dan cita rasa superior dibanding yang lainnya. Kopi banyak diolah menjadi produk kopi bubuk. Karakteristik kopi bubuk dipengaruhi oleh banyak faktor salah satunya adalah berdasarkan cara pengolahan. Pada pengolahan dari buah kopi sampai menjadi biji kopi suatu proses yang pasti dilalui, yaitu fermentasi. Fermentasi berpengaruh terhadap karakteristik kopi bubuk yang dihasilkan. Penelitian ini difokuskan mengamati karakteristik kopi bubuk Arabika hasil fermentasi menggunakan Saccharomyces cerevisiae. Parameter karakteristik kopi bubuk yang diamati meliputi kadar air, sari kopi dan kadar kafein. Parameter penunjang karakteristik lainnya, yaitu pH seduhan kopi bubuk dan uji fitokimia. Selain itu, pada proses fermentasi juga diamati pH fermentasi, kadar gula pereduksi dan uji kualitatif etanol. Konsentrasi Saccharomyces cerevisiae divariasikan 0% (K0), 1% (K1), 2% (K2), 3% (K3) dan 4% (K4) dengan durasi waktu fermentasi selama 24 jam. Karakteristik kopi bubuk Arabika yang dihasilkan sesuai dengan SNI Kopi Bubuk 01-3542-2004 dengan nilai sebagai berikut: kadar air 2,33–1,6% b/b, sari kopi 30,7 – 30,3% b/b, kadar kafein 1,18–1,01% b/b dan pH seduhan kopi bubuk 6,5–5,1. Alkaloid, saponin dan tanin terdeteksi pada semua perlakuan sampel kopi bubuk. Flavonoid hanya terdeteksi pada perlakuan sampel kopi bubuk K0. pH fermentasi pada keadaan awal 5,61 dan setelah fermentasi 4,91–3,89. Kadar gula pereduksi pada keadaan awal 32,35% b/b dan setelah fermentasi 21,2–4,3% b/b. Etanol terdeteksi pada semua sampel sebelum dan setelah fermentasi.Kata kunci: Coffea Arabica L, mutu kopi bubuk, Fermentasi, Saccharomyces cerevisiae

Ex-situ conservation of Sumatran tigers (Panthera tigris sumatrae) in Ragunan wildlife park, Jakarta                 Sumatran tiger (Panthera tigris sumatrae) is one of the endemic species of Indonesia, which until now still live on the island of Sumatra. According to the International Conservation Agency, the existence of the animal is approaching extinction. Taman Marga Satwa Ragunan is one of Sumatran tiger conservation institution. The purpose of the research was to know the breeding of Sumatran tiger in Ragunan Wildlife Park conservation area, to know the proper conservation strategy for Sumatran tiger and to know Sumatran tiger activity ex-situ. The research was conducted at the Sumatran Tiger in Taman Marga Satwa Ragunan. Data were analyzed by descriptive analysis. Taman Marga Satwa Ragunan has made a proper effort in tiger conservation, this is marked by an increase in the Sumatran Tiger population.Keywords: Sumatran Tiger, Conservation, Ragunan Wildlife Park ABSTRAK Harimau sumatera (Panthera tigris sumatrae) merupakan salah satu satwa endemik Indonesia, yang hingga saat ini masih hidup di pulau Sumatera. Menurut lembaga konservasi Internasional keberadaan satwa ini sudah mendekati kepunahan.Taman Marga Satwa Ragunan adalah salah satu lembaga konservasi Harimau Sumatera.Tujuan penelitian ini adalah mengetahui perkembangbiakan harimau sumatera dikawasan konservasi TMR, mengetahui strategi konservasi yang tepat untuk harimau sumatera dan mengetahui aktivitas harimau sumatera secara ex-situ.Penelitian ini di lakukan di kandang Harimau Sumatera di Taman Marga Satwa Ragunan, hasil dianalisis dengan analisis deskriptif.Taman Margasatawa Ragunan merupakan tempat konservasi yang cocok bagi Harimau Sumatera, ini ditandai dengan adanya peningkatan populasi dari awal tahun pendirian TMR (Tahun 1980) sampai dengan saat sekarang iniKata Kunci : Harimau Sumatera, Konservasi, TMR

Increase environmental problems, such as air pollution and temperatures increase in DKI Jakarta, make the existence of urban forests very important. Trees have an important role becausethey function as the most efficient carbon sink and storage in urban areas. Along with the<br />increasing number of visitors carrying vehicles, the higher the potential for air pollution in Ragunan Wildlife Park (TMR). The objectives of this study are: To analyze the community structure of tree species that have potential carbon stocks, and estimate carbon stocks stored in tree trunks. The study was conducted in four regions (north, west, east, south) Ragunan Wildlife<br />Park, DKI Jakarta. Vegetation analysis was carried out by calculating the Important Value Index (INP), and carbon stock analysis was carried out through the Allometric approach. The highest INP value was mahoni (Swietinia macrophylla) amounting to 45.51%, cengal pasir (Hopea<br />odorata) 33.31%, and dao (Dracontomelon dao) 28.26%. The largest amount of carbon reserves is found in the western region, which is 52,503 kg / ha, and the largest contribution of carbon stocks is from dao trees (Dracontomelon dao) of 30,091 kg / ha, cengal sand 25,372 kg / ha, oil<br />palm (Elaeis guinensis).