230 research outputs found

    Synthesis and Characterization of Chitosan-Citrate Microparticle Using Ionic Gelation Methods

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    A study has been conducted aimed to synthesize chitosan-citrate using the ionic gelation method and its characterization with FTIR, SEM, SAA, and PSA, as well as solubility and swelling tests. The results showed that chitosan reacted with sodium citrate producing chitosan-citrate particles. The product of chitosan-citrate has a rough and thickened surface morphology. Surface area is obtained by 35.233 m2/g and pore size is 0.027 cc/g, smaller than chitosan. Based on solubility and swelling tests in acidic, alkaline, and neutral media, chitosan-citrate has good resistance and low swelling effect

    Ekstraksi Dan Karakterisasi Kitosan Dari Kulit Udang Windu (Penaeus monodon) Serta Proses Depolimerisasi Kitosan Dengan Hidrogen Peroksida Berdasarkan Variasi Suhu Pemanasan

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    An extraction of chitin from shell of the tiger shrimp (Penaeus monodon), a convertion chitin into chitosan and depolymerization chitosan into oligochitosan using hydrogen peroxide based on variations in heating temperature have been done. Chitosan had depolymerized and it’s molecular weight had tested by end group analysis method and it’s degree of deacetylation had tested by UV-Vis spectrophotometry method. Oligochitosan had obtained from the conversion of chitin is isolated from the shell of tiger shrimp and from commercial chitin. The content of chitin obtained in tiger shrimp shells was 35.90% while the result of the conversion of commercial chitin into chitosan amounted to 62.33%.  Characterization of functional groups using FTIR spectrophotometry showed that the conversion of chitosan from chitin commercial have absorption bands of 3617.56 (OH), 3050.47 - 3127.63 (-NH stretching), 2894.24 (-CH methylene), 1679.06 (-C = O), 1564.30 (-NH bending), and 1076.30 cm-1 (-CO-). The commercial chitosan which is characterized by FTIR spectrophotometric method also supports the results of the conversion of chitosan from chitin commercial.  In the process of depolymerization of chitosan by hydrogen peroxide was found that the greater heating temperature was used, the smaller the percent yield and molecular weight of oligochitosan were at 40 oC, 50 oC, 60 oC and 70 oC gained weight average molecular oligochitosan were 1030.12 g/mol, 1019, 28 g/mol, 978.12 g/mol, and 908.82 g/mol, respectivel

    Ekstraksi Dan Karakterisasi Kitosan Dari Kulit Udang Windu (Penaeus monodon) Serta Proses Depolimerisasi Kitosan Dengan Hidrogen Peroksida Berdasarkan Variasi Suhu Pemanasan

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    An extraction of chitin from shell of the tiger shrimp (Penaeus monodon), a convertion chitin into chitosan and depolymerization chitosan into oligochitosan using hydrogen peroxide based on variations in heating temperature have been done. Chitosan had depolymerized and it’s molecular weight had tested by end group analysis method and it’s degree of deacetylation had tested by UV-Vis spectrophotometry method. Oligochitosan had obtained from the conversion of chitin is isolated from the shell of tiger shrimp and from commercial chitin. The content of chitin obtained in tiger shrimp shells was 35.90% while the result of the conversion of commercial chitin into chitosan amounted to 62.33%.  Characterization of functional groups using FTIR spectrophotometry showed that the conversion of chitosan from chitin commercial have absorption bands of 3617.56 (OH), 3050.47 - 3127.63 (-NH stretching), 2894.24 (-CH methylene), 1679.06 (-C = O), 1564.30 (-NH bending), and 1076.30 cm-1 (-CO-). The commercial chitosan which is characterized by FTIR spectrophotometric method also supports the results of the conversion of chitosan from chitin commercial.  In the process of depolymerization of chitosan by hydrogen peroxide was found that the greater heating temperature was used, the smaller the percent yield and molecular weight of oligochitosan were at 40 oC, 50 oC, 60 oC and 70 oC gained weight average molecular oligochitosan were 1030.12 g/mol, 1019, 28 g/mol, 978.12 g/mol, and 908.82 g/mol, respectivel

    Ekstraksi Dan Karakterisasi Kitosan Dari Kulit Udang Windu (Penaeus monodon) Serta Proses Depolimerisasi Kitosan Dengan Hidrogen Peroksida Berdasarkan Variasi Suhu Pemanasan

    Get PDF
    An extraction of chitin from shell of the tiger shrimp (Penaeus monodon), a convertion chitin into chitosan and depolymerization chitosan into oligochitosan using hydrogen peroxide based on variations in heating temperature have been done. Chitosan had depolymerized and it’s molecular weight had tested by end group analysis method and it’s degree of deacetylation had tested by UV-Vis spectrophotometry method. Oligochitosan had obtained from the conversion of chitin is isolated from the shell of tiger shrimp and from commercial chitin. The content of chitin obtained in tiger shrimp shells was 35.90% while the result of the conversion of commercial chitin into chitosan amounted to 62.33%.  Characterization of functional groups using FTIR spectrophotometry showed that the conversion of chitosan from chitin commercial have absorption bands of 3617.56 (OH), 3050.47 - 3127.63 (-NH stretching), 2894.24 (-CH methylene), 1679.06 (-C = O), 1564.30 (-NH bending), and 1076.30 cm-1 (-CO-). The commercial chitosan which is characterized by FTIR spectrophotometric method also supports the results of the conversion of chitosan from chitin commercial.  In the process of depolymerization of chitosan by hydrogen peroxide was found that the greater heating temperature was used, the smaller the percent yield and molecular weight of oligochitosan were at 40 oC, 50 oC, 60 oC and 70 oC gained weight average molecular oligochitosan were 1030.12 g/mol, 1019, 28 g/mol, 978.12 g/mol, and 908.82 g/mol, respectivel

    Real-Gas Effects and Phase Separation in Underexpanded Jets at Engine-Relevant Conditions

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    A numerical framework implemented in the open-source tool OpenFOAM is presented in this work combining a hybrid, pressure-based solver with a vapor-liquid equilibrium model based on the cubic equation of state. This framework is used in the present work to investigate underexpanded jets at engine-relevant conditions where real-gas effects and mixture induced phase separation are probable to occur. A thorough validation and discussion of the applied vapor-liquid equilibrium model is conducted by means of general thermodynamic relations and measurement data available in the literature. Engine-relevant simulation cases for two different fuels were defined. Analyses of the flow field show that the used fuel has a first order effect on the occurrence of phase separation. In the case of phase separation two different effects could be revealed causing the single-phase instability, namely the strong expansion and the mixing of the fuel with the chamber gas. A comparison of single-phase and two-phase jets disclosed that the phase separation leads to a completely different penetration depth in contrast to single-phase injection and therefore commonly used analytical approaches fail to predict the penetration depth.Comment: Preprint submitted to AIAA Scitech 2018, Kissimmee, Florid

    PELATIHAN CODING MENGGUNAKAN SCRATCH KEPADA SISWA-SISWI SD NEGERI 100 MALUKU TENGAH

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    The purpose of this activity is to explore the effectiveness of coding training using Scratch for students of Elementary School (SD) Negeri 100 Central Maluku. The training method is carried out through a series of sessions designed to introduce basic programming concepts and the use of Scratch as a visual programming tool. This research involved students of SD Negeri 100 Central Maluku as the subject of this activity. Data was collected through pre and post training tests, as well as participatory observation during training sessions. The results showed that coding training using Scratch was effective in increasing students' understanding of programming concepts and their ability to create interactive projects using Scratch. In addition, this training also improves students' critical thinking skills, creativity, and cooperation. These findings provide strong support for the introduction of coding using Scratch at the elementary education level and emphasize the importance of integrating programming into the school curriculu

    Peningkatan Nilai Ekonomis Kelapa melalui Pembuatan Cuka dari Air Kelapa di Desa Morella

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    Vinegar is a seasoning that gives food a sour taste. Vinegar is obtained from the fermentation of ethanol by bacteria anaerobically. Ingredients that can be used to make alcoholic fermentation include dates, rice, and coconut water. Young coconut water is directly consumed, while coconut water from ripe fruit is disposed of as waste. Morella village is located on the coast of the island of Ambon, where coconut plants are in abundance. The abundance of this coconut plant is directly proportional to the old coconut water that is dumped into the environment. To decrease the coconut water waste, it is necessary to conduct training on making vinegar from coconut water for the people of Morella village. This community service was carried out based on counseling and training on making vinegar for the Morella Village people. Counseling was done to convey the benefits of Vinegar and how to make it. The training was carried out by demonstrating the procedure for making vinegar and providing tools and materials to partners and videos to produce vinegar independently. The results of vinegar products from Morella Village are reported to the service team and used as evidence of the success of the vinegar-making training. The results provide information that vinegar are products that the people of Morella village can cultivate as an opportunity to increase their economy.Cuka merupakan salah satu produk olahan dari air kelapa yang merupakan hasil fermentasi. Cuka hasil fermentasi air kelapa memberikan tambahan nilai ekonomis. Penambahan nilai ekonomis ini dipicu oleh manfaat yang dimiliki oleh cuka tersebut. Masyarakat Desa Morella berada pada pesisir pantai pulau Ambon, yang ditumbuhi tanaman kelapa secara melimpah. Melimpahnya tanaman kelapa ini belum secara maksimal dimanfaatan oleh masyarakat desa Morella. Dengan adanya masalah ini, maka mendorong pelaksanaan pelatihan pembuatan Cuka kepada masyarakat desa Morella, Pulau Ambon. Pengabdian kepada masyarakat ini dilakukan berbasis penyuluhan dan pelatihan pembuatan cuka kepada masyarakat Desa Morella. Penyuluhan dilakukan untuk menyampaikan mengenai manfaat Cuka dan cara pembuatannya. Pelatihan dilakukan dengan cara memperagakan prosedur pembuatan cuka serta memberikan alat dan bahan kepada mitra serta video untuk dapat memproduksi cuka secara mandiri. Hasil produk cuka dari masyarakat Desa Morella dilaporkan kepada tim pengabdian dan dijadikan sebagai bukti keberhasilan pelatihan pembuatan cuka. Hasil yang didapatkan memberikan informasi bahwa produk cuka adalah produk yang dapat diusahakan oleh masyarakat desa Morella sebagai peluang peningkatan perekonomian mereka

    Tear fluid biomarkers in ocular and systemic disease: potential use for predictive, preventive and personalised medicine

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    In the field of predictive, preventive and personalised medicine, researchers are keen to identify novel and reliable ways to predict and diagnose disease, as well as to monitor patient response to therapeutic agents. In the last decade alone, the sensitivity of profiling technologies has undergone huge improvements in detection sensitivity, thus allowing quantification of minute samples, for example body fluids that were previously difficult to assay. As a consequence, there has been a huge increase in tear fluid investigation, predominantly in the field of ocular surface disease. As tears are a more accessible and less complex body fluid (than serum or plasma) and sampling is much less invasive, research is starting to focus on how disease processes affect the proteomic, lipidomic and metabolomic composition of the tear film. By determining compositional changes to tear profiles, crucial pathways in disease progression may be identified, allowing for more predictive and personalised therapy of the individual. This article will provide an overview of the various putative tear fluid biomarkers that have been identified to date, ranging from ocular surface disease and retinopathies to cancer and multiple sclerosis. Putative tear fluid biomarkers of ocular disorders, as well as the more recent field of systemic disease biomarkers, will be shown
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