19 research outputs found
Uji Aktivitas Antioksidan Mikrokapsul Ekstrak Limbah Serabut Kelapa Sawit (Elaeis Guineensis Jacq) Dengan Metode 1,1-difenil-2-pikrilhidrazil (Dpph)
Limbah serabut kelapa sawit merupakan salah satu limbah yang pemanfaatannya kurang optimal. Choo et al. (1996) dalam Neoh et al. (2011) menyebutkan bahwa limbah serabut kelapa sawit mengandung karotenoid, tokoferol, tokotrienol, dan sterol. Senyawa dalam limbah serabut kelapa sawit memiliki potensi sebagai antioksidan.Namun, senyawa-senyawa tersebut bersifat tidak stabil dan mudah rusak karena pengaruh lingkungan (cahaya, lembab, dan oksigen) sehingga perlu dilakukan inovasi untuk meningkatkan stabilitas dan melindungi senyawa tersebut salah satunya dengan teknik mikroenkapsulasi.Penelitian ini bertujuan untuk mengetahui karakteristik dan aktivitas antioksidan sediaan mikrokapsul ekstrak limbah serabut kelapa sawit.Ekstrak didapatkan dengan cara maserasi menggunakan pelarut metanol basa dengan perbandingan 1:10.Selanjutnya dilakukan mikroenkapsulasi ekstrak menggunakan metode spray drying. Uji aktivitas antioksidan mikrokapsul dilakukan dengan metode 1,1-difenil-2-pikrilhidrazil (DPPH). Penelitian menunjukkan mikrokapsul ekstrak limbah serabut kelapa sawit mampu memberikan aktivitas antioksidan pada konsentrasi 10, 20, 30, 40, dan 50 ppm dengan nilai rata-rata EC50sebesar 125,4341 ppm dan baku Butyl Hydroxy Toluene (BHT) memiliki nilai rata-rata EC50sebesar 4,7650 ppm. Mikrokapsul yang dihasilkan memiliki rendemen mikrokapsul 10,90%, kadar air 5,74%, dan kelarutan 99,02%
Carbon emissions from oil palm induced forest and peatland conversion in sabah and Sarawak, Malaysia
© 2020 by the authors. Licensee MDPI, Basel, Switzerland. The palm oil industry is one of the major producers of vegetable oil in the tropics. Palm oil is used extensively for the manufacture of a wide variety of products and its production is increasing by around 9% every year, prompted largely by the expanding biofuel markets. The rise in annual demand for biofuels and vegetable oil from importer countries has caused a dramatic increase in the conversion of forests and peatlands into oil palm plantations in Malaysia. This study assessed the area of forests and peatlands converted into oil palm plantations from 1990 to 2018 in the states of Sarawak and Sabah, Malaysia, and estimated the resulting carbon dioxide (CO2) emissions. To do so, we analyzed multitemporal 30-m resolution Landsat-5 and Landsat-8 images using a hybrid method that combined automatic image processing and manual analyses. We found that over the 28-year period, forest cover declined by 12.6% and 16.3%, and the peatland area declined by 20.5% and 19.1% in Sarawak and Sabah, respectively. In 2018, we found that these changes resulted in CO2 emissions of 0.01577 and 0.00086 Gt CO2-C yr−1, as compared to an annual forest CO2 uptake of 0.26464 and 0.15007 Gt CO2-C yr−1, in Sarawak and Sabah, respectively. Our assessment highlights that carbon impacts extend beyond lost standing stocks, and result in substantial direct emissions from the oil palm plantations themselves, with 2018 oil palm plantations in our study area emitting up to 4% of CO2 uptake by remaining forests. Limiting future climate change impacts requires enhanced economic incentives for land uses that neither convert standing forests nor result in substantial CO2 emissions
Isoprene hotspots at the Western Coast of Antarctic Peninsula during MASEC′16
Isoprene (C5H8) plays an important role in the formation of surface ozone (O3) and the secondary organic aerosol (SOA) which contributed to the climate change. This study aims to determine hourly distribution of tropospheric isoprene over the Western Coast of Antarctic Peninsula (WCAP) during the Malaysian Antarctic Scientific Expedition Cruise 2016 (MASEC′16). In-situ measurements of isoprene were taken using a custom-built gas chromatography with photoionization detector, known as iDirac. Biological parameters such as chlorophyll a (chl-a) and particulate organic carbon (POC) were compared to the in-situ isoprene measurements. Significant positive correlation was observed between isoprene and POC concentrations (r2 = 0.67, p < 0.001), but not between isoprene and chl-a. The hotspots of isoprene over maritime Antarctic were then were investigated using NAME dispersion model reanalysis. Measurements showed that isoprene mixing ratio were the highest over region of King George Island, Deception Island and Booth Island with values of ∼5.0, ∼0.9 and ∼5.2 ppb, respectively. Backward trajectory analysis showed that air masses may have lifted the isoprene emitted by marine algae. We believe our findings provide valuable data set of isoprene estimation over the under sampled WCAP
Nowcasting and Forecasting Economic Growth in the Euro Area Using Principal Components
Search Space and Average Proof Length of Resolution
In this paper we introduce a definition of search trees for resolution based proof procedures. This definition describes more clearly the differences between the restrictions of resolution. Applying this concept to monotone restrictions of the resolution it is shown that the average proof length for propositional formulas is at most four times as large as for unrestricted resolution. The search trees used within this paper also allow the representation of space bounded resolution. 1 Introduction Many efforts have been made to classify proof procedures like resolution, restrictions of resolution and other systems like cutting plane systems, Davis--Putnam algorithms etc. with respect to the minimal proof length, e.g. see [6]. Also restrictions of the resolution proof procedure can be classified in this way [2], [3], [4], [5], [9], [10]. But these papers deal with worst--case complexities. In practice many restrictions show to be very efficient --- e.g. N--resolution --- whereas they are..
An Algorithm for Resource-based Configuration
We present an architecture independent algorithm for resource based configuration. A description of a knowledge base (static part) is presented along with its realization (data structure). A description of the configuration algorithm is given in terms of a search path, employed heuristics and cost based cut--off optimization. An architecture independent implementation and its parallelisation are described. Finally, heuristics which guide the search algorithm are presented and analyzed. Our goal --- the investigation of heuristics and mechanization of the learning process by means of massive parallel machines --- is outlined. 1 Introduction Configuration is usually described as the process of composing a technical system from a predefined set of objects. The result of such a process is called This work is supported by the DFG-SFB 376 "Massive Parallelit¨at". y WWW: http://www.uni-paderborn.de/fachbereich/AG/agklbue/ configuration too and has to fullfill a set of constraints give..
Northern Hemisphere temperature reconstruction during the last millennium using multiple annual proxies
A Penentuan Parameter Desain Mesin Perontok Sorgum Berdasarkan Karakteristik Fisik dan Mekanik Tanaman Sorgum: Identification of the Physical Characteristics of Sorghum Bioguma for the Design of a Sorghum Thresher Machine
An effective and efficient threshing mechanism for sorghum plants requires information about technical properties, including the physical and mechanical properties of this sorghum plant. This study aims to determine some of the physical properties of the sorghum variety Bioguma in the seeds, stems, and leaves for the threshing mechanism of the sorghum seeds and stems. This study used a descriptive method with several repetitions from 3 to 30, depending on the measured parameters. All sampling was done randomly. The sorghum plants tested were from several fields in Majalengka and Bogor. The dimensions of the Bioguma variety of sorghum seeds, which have values ranging from 4.23 mm to 5.88 mm in width, 2.49 mm to 2.85 mm in thickness, and 3.95 mm to 4.98 mm in height, are considered in the design of threshing cylinder sieve sizes, namely using a perforated plate with a diameter of 6 mm; threshing power requirements with threshing cylinder speed on the designed threshing machine, assuming a threshing cylinder diameter of 51 cm and a rate of 700 rpm requires a power of 9.17 kW.Proses mekanisme perontokan tanaman sorgum yang efektif dan efisien memerlukan informasi tentang sifat-sifat teknis yang meliputi sifat fisik maupun mekanik dari jenis tanaman sorgum tersebut. Penelitian ini bertujuan untuk menentukan beberapa sifat fisik tanaman sorgum varietas Bioguma pada bagian biji, batang dan daun untuk proses mekanisme perontokan biji dan batang tanaman sorgum. Penelitian ini menggunakan metode deskriptif dengan jumlah ulangan 3 sampai 30 tergantung dari parameter yang diukur. Semua pengambilan sampel dilakukan secara acak. Tanaman sorgum yang diuji adalah dari beberapa lahan Majalengka dan Bogor. Dimensi biji sorgum varietas Bioguma yang memiliki nilai kisaran lebar 4.23 mm hingga 5.88 mm, tebal 2.49 mm hingga 2.85 mm, dan tinggi 3.95 mm hingga 4.98 mm menjadi pertimbangan disain ukuran saringan silinder perontok yaitu menggunakan plat berlubang dengan diameter 6 mm; kebutuhan daya perontokan dengan kecepatan silinder perontok pada mesin perontok yang dirancang, diasumsikan diameter silinder perontok 51 cm dan kecepatannya 700 rpm dibutuhkan daya 9,17 Kw