Produksi Etanol dari Tetes Tebu oleh Saccharomyces Cerevisiae Pembentuk Flok (NRRL – Y 265)

Efisiensi produksi bioetanol diperoleh melalui ketepatan pemilihan jenis mikroorganisme, bahan baku, dan kontrol proses fermentasi. Alternatif proses untuk meminimalisasi biaya produksi etanol adalah dengan mengeliminasi tahap pemisahan sentrifugasi sel dari produk karena memerlukan biaya instalasi dan biaya perawatan yang tinggi. Proses sentrifugasi merupakan tahapan penting untuk memisahkan sel mikroba dari medium fermentasi pada produksi bioetanol. Untuk meminimalisir biaya produksi akibat proses tersebut digunakan inokulum Saccharomyces cerevisiae pembentuk flok dan tetes tebu sebagai sumber gula. Penelitian ini bertujuan untuk mendapatkan konsentrasi penambahan inokulum Saccharomyces cerevisiae pembentuk flok dan konsentrasi sumber gula dalam tetes tebu yang tepat dalam produksi etanol yang maksimum. Saccharomyces cerevisiae sebanyak 5%, 10%, dan 15% (v/v) diinokulasikan pada medium tetes tebu hasil pretreatment dengan kandungan gula 15%, 20%, dan 25% (b/v) pada pH 5. Fermentasi dilakukan pada suhu 30°C dan agitasi 100 rpm selama 72 jam. Etanol tertinggi didapat pada kondisi konsentrasi inokulum 10% (v/v) dan konsentrasi sumber gula 15% (b/v) yaitu sebesar 8, 792% (b/v) dengan yield etanol sebesar 65%

ANALISIS DAN PERANCANGAN INFRASTRUKTUR PRIVATE CLOUD DENGAN OPENSTACK

Abstrak: Pusat TIK Nasional menggunakan infrastuktur IT konvensional dimana penggunaan resource masih bersifat boros, dan manajemen serta monitoring yang rumit. Oleh karena itu, perlu dirancang sebuah infrastruktur private cloud menggunakan Openstack yang dapat melakukan resource sharing. Tujuan perancangan privat cloud adalah melakukan efisiensi dan skalabilitas yang tinggi serta memudahkan akses, monitoring dan manajemen secara terpusat. Berdasarkan hasil penelitian yang dilakukan, sistem infrastruktur private cloud yang dirancang dan dibangun dengan Openstack versi Kilo menggunakan satu node controller dan satu node compute mampu melakukan efisiensi sumber daya infrastruktur IT sebesar 1 CPU dan 638.296 bytes RAM dan mampu melakukan resource sharing infrastruktur IT.Kata Kunci: Cloud Computing, Private Cloud, Infrastructure as a Service, IaaS, Openstac

Influence of nonseasonal river discharge on sea surface salinity and height

© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Chandanpurkar, H. A., Lee, T., Wang, X., Zhang, H., Fournier, S., Fenty, I., Fukumori, I., Menemenlis, D., Piecuch, C. G., Reager, J. T., Wang, O., & Worden, J. Influence of nonseasonal river discharge on sea surface salinity and height. Journal of Advances in Modeling Earth Systems, 14(2), (2022): e2021MS002715, https://doi.org/10.1029/2021MS002715.River discharge influences ocean dynamics and biogeochemistry. Due to the lack of a systematic, up-to-date global measurement network for river discharge, global ocean models typically use seasonal discharge climatology as forcing. This compromises the simulated nonseasonal variation (the deviation from seasonal climatology) of the ocean near river plumes and undermines their usefulness for interdisciplinary research. Recently, a reanalysis-based daily varying global discharge data set was developed, providing the first opportunity to quantify nonseasonal discharge effects on global ocean models. Here we use this data set to force a global ocean model for the 1992–2017 period. We contrast this experiment with another experiment (with identical atmospheric forcings) forced by seasonal climatology from the same discharge data set to isolate nonseasonal discharge effects, focusing on sea surface salinity (SSS) and sea surface height (SSH). Near major river mouths, nonseasonal discharge causes standard deviations in SSS (SSH) of 1.3–3 practical salinity unit (1–2.7 cm). The inclusion of nonseasonal discharge results in notable improvement of model SSS against satellite SSS near most of the tropical-to-midlatitude river mouths and minor improvement of model SSH against satellite or in-situ SSH near some of the river mouths. SSH changes associated with nonseasonal discharge can be explained by salinity effects on halosteric height and estimated accurately through the associated SSS changes. A recent theory predicting river discharge impact on SSH is found to perform reasonably well overall but underestimates the impact on SSH around the global ocean and has limited skill when applied to rivers near the equator and in the Arctic Ocean.This research was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004) with support from the Physical Oceanography (PO) and Modeling, Analysis, and Prediction (MAP) Programs. High-end computing resources for the numerical simulation were provided by the NASA Advanced Supercomputing Division at the Ames Research Center