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AKTIVITAS ANTIBAKTERI KITOSAN TERHADAP BAKTERI S.aureus Mardiyah Kurniasih; Dwi Kartika
Molekul Vol 4, No 1 (2009)
Publisher : Universitas Jenderal Soedirman

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (127.248 KB) | DOI: 10.20884/1.jm.2009.4.1.56

Abstract

Chitosan is the N-deacetylated derivative of chitin. Chitosan is biodegradable, biocompatible and non-toxic. Chitosan is polycationic in acidic media and give antibacterial activity. In this paper, antibacterial activity of chitosan have been studied.Chitosan had been isolated from white shrimp. Antibacterial activity of chitosan solutions was examined against S. aureus The result showed that antimicrobial effect on S. aureus was strengthened as the choitosan concentrate decreased.
KECEPATAN ADUK DAN WAKTU KONTAK OPTIMUM PEMBUATAN BIODIESEL DARI MINYAK JELANTAH Dwi Kartika; Eva Vaulina; Senny Widyaningsih; Moch. Chasani
Molekul Vol 5, No 1 (2010)
Publisher : Universitas Jenderal Soedirman

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (241.422 KB) | DOI: 10.20884/1.jm.2010.5.1.74

Abstract

Synthesis of biodiesel from waste cooking oil using activated natural zeolite catalyst has been done. Activation of the natural zeolite was done by refluxing with HCl 6M for 30 min, calcining and oxydizing at 500°C for 2 hours, consecutively. The variation of stirring speed were 350, 700, 1100 and 1200 rpm. The variation of reaction time were varied from 15, 30, 45, 60, and 120 min. The conversion of biodiesel was determined by 1H NMR spectrometer. The results showed that the optimum condition of biodiesel synthesis using esterification process were reached at 700 rpm and 15 minutes, which gave biodiesel conversion of 100%.
PEMANFAATAN KATALIS NI/ZEOLIT PADA HIDROGENASI KATALITIK ETIL PALMITAT MENJADI SETIL ALKOHOL Dwi Kartika; Triyono Triyono; Karna Wijaya; Dewi Yuanita L; D. Setyawan PH D. Setyawan PH
Molekul Vol 5, No 2 (2010)
Publisher : Universitas Jenderal Soedirman

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (111.534 KB) | DOI: 10.20884/1.jm.2010.5.2.80

Abstract

The catalytic hydrogenation of methyl palmitate to cetyl alcohol using Ni supported on activated natural zeolite catalysts (Ni/Zeolite) has been carried out. In this work, the effect of catalyst amounts and H2 flow rate on methyl palmitate conversion and yield of cetyl alcohol were studied. Catalytic hydrogenation was performed in stainless steel fixed bed reactor. The methyl palmitate (10 g) was loaded into the reactor vessel at 400 °C for 30 minutes. In order to study the effects of catalyst amount at constant H2 flow rate, the catalyst were varied i.e. 5, 10, and 15 g. To investigate the effects of H2 flow rate were varied from 20, 40, and 60 mL.min-1 at constant catalyst amount. The composition of the products was analyzed by GC and GC-MS. The results showed that methyl palmitate conversion increase with the increasing of catalyst amount. The highest methyl palmitate conversion (45.62 %) and yield of cetyl alcohol (36.44 %) were obtained for 15 g catalyst and 40 mL. min-1 H2 flow rate.
Immobilization and Characterization of Bacillus Thuringiensis HCB6 Amylase in Calcium Alginate Matrix Zusfahair Zusfahair; Dian Riana Ningsih; Dwi Kartika; Amin Fatoni; Indah Permatawati
Molekul Vol 12, No 1 (2017)
Publisher : Universitas Jenderal Soedirman

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (508.968 KB) | DOI: 10.20884/1.jm.2017.12.1.249

Abstract

Free enzyme in solution react with substrates to result in products which cannot be recovered for reuse. These problems can be overcome to a certain extent by the use of enzyme immobilization method. Immobilized enzymes are more robust and more resistant to condition changes. More importantly, the heterogeneous immobilized enzyme systems allow an easy recovery of both enzymes and products, multiple re-uses of enzymes, and continuous operation of enzymatic processes. Entrapment of enzymes in Ca-alginate is one of the simplest methods of immobilization. The aim of this research was to obtain the optimum condition of the making of immobilized amylase beads using a Ca-alginate bead and to determine its characteristics. The optimization of immobilized amylase beads includes variation of sodium alginates and variations of enzyme contact time with CaCl2. The characterization of immobilized amylase includes determination of optimum substrate concentration, optimum pH, and optimum incubation time as well as amylase stability test. Amylase activity was determined by using dinitro salicylic (DNS) method. The results showed that the optimum immobilized amylase obtained at alginate concentrations of 5% (w/v), contact time of 60 minutes and immobilization efficiency of 67.5%. Furthermore, immobilized amylase showed optimum substrate concentration of 1.5-2.5% (w/v), optimum pH of 6, an optimum incubation time of 20 minutes with the activity of 179.8 U/mL. The KM value for free amylase and immobilized amylases were 0.3 mM and 0.12 mM respectively. Vmax value for free amylase and immobilized amylases were 105.3 U/mL and 10.1 U/mL respectively. Immobilized Amylase can be used up to six times with the residual activity of 52.7%.
Pelatihan Teknis Pembuatan Instalasi Sederhana Pengolahan Air Hujan Menjadi Air Minum Bagi Masyarakat Desa Banteran Kecamatan Sumbang Kabupaten Banyumas Muhammad Sehah; Urip Nurwijayanto Prabowo; Dwi Kartika
Serambi Abdimas Vol 3 No 2 (2022): Jurnal Serambi Abdimas
Publisher : Universitas Jenderal Soedirman

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20884/1.sa.2022.3.2.6815

Abstract

Pelatihan teknis pembuatan instalasi sederhana pengolahan air hujan menjadi air minum bagi masyarakat Desa Banteran Kecamatan Sumbang Kabupaten Banyumas telah dilaksanakan. Tujuan kegiatan adalah untuk memberikan pelatihan teknis bagi masyarakat Desa Banteran terkait pembuatan instalasi sederhana pengolahan air hujan menjadi air minum. Tahapan kegiatan yang telah dilakukan meliputi pelatihan teknis dan realisasi pembuatan instalasi. Kegiatan ini diharapkan memberikan kontribusi bagi pemerintah dan masyarakat dalam membantu penyediaan air minum yang murah dan mudah sehingga terwujud pola hidup sehat dan ekonomis. Setelah pelatihan teknis dan realisasi instalasi dilaksanakan, selanjutnya dilakukan observasi. Hasil observasi menggunakan kuisioner menunjukkan bahwa sebagian besar peserta memberikan respon positif terhadap kegiatan ini. Hal ini ditunjukkan dari capaian rata-rata keberhasilan kegiatan sebesar 78,83%; dengan nilai capaian tertinggi sebesar 88,33% untuk item dukungan dilakukan kegiatan pelatihan teknis untuk menambah wawasan masyarakat desa tentang teknologi tepat guna; serta nilai capaian terendah sebesar 66,67% untuk kesediaan peserta menjadi pioneer dalam menyebarluaskan hasil kegiatan pelatihan teknis. Rendahnya nilai capaian ini diperkirakan karena peserta belum memiliki kesiapan dan pemahaman yang cukup untuk menjadi pioneer penyebarluasan hasil-hasil kegiatan. Hal ini didukung pemahaman peserta terhadap materi pelatihan teknis yang telah disampaikan tim dosen yang hanya memperoleh capaian sebesar 73,33%.
Pemanfaatan CaCO3 Terkalsinasi Dalam Pembuatan Biodiesel dari Minyak Biji Kapuk Dwi Kartika; Inna Sofyana Ulyan Nisa; Dadan Hermawan
Jurnal Serambi Engineering Vol. 9 No. 2 (2024): April 2024
Publisher : Faculty of Engineering, Universitas Serambi Mekkah

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Biodiesel production from kapok seed oil using calcined CaCO3 has been done. The objective of this study is to investigate the impact of varying concentrations of calcined CaCO3 catalysts on the biodiesel manufacturing process. The production of biodiesel involves two distinct processes, namely esterification and transesterification. The variation concentrations of the CaCO3 catalyst used in the experiment were 1%, 2%, 3%, 4%, and 5% (w/w). The results showed that the biodiesel nearly satisfied the ASTM D-1298 standard. The biodiesel generated using a CaCO3 catalyst with a concentration of 1% (w/w) and a contact period of 120 minutes exhibited the highest quality, with a biodiesel conversion rate of 41.57%.