Determination of effective diffusion coefficient of immobilized Baker's yeast invertase in various concentration of PVA-alginate matrix

Baker's yeast invertase is immobilized in PVA-alginate matrix using an improved method. PVA beads were prepared by adding calcium alginate to improve its stability, mechanical and chemical properties. Boric acid was used as the cross-linking agent and additional chemicals consisting of 10% boric acid and sodium sulphate solution was used as a treatment solution to harden the PVA-alginate beads. The determination of the effective diffusion of PVA-alginate matrix the vital step in optimizing the preparation of immobilized and water-soluble biocatalyst. In this study the two-level full factorial design was used to investigate the effect of PVA and boric acid concentrations and diffusions coefficient. Diffusion coefficient (De) is one of the factors that significantly affect the mass transport within the immobilization matrix. De value varies for each concentration of PVA and boric acid. The result concluded that both factors significantly affect the De. A maximum De value of 5.0141 x 10(-5) cm2s-1 was obtained at boric acid and PVA concentraion of 7w/v and 10.5 w/v respectively

Peranan Satuan Polisi Pamong Praja dalam Menata dan Membina Pedagang Kaki Lima di Kota Banda Aceh

Salah satu wujud kewenangan Satuan Polisi Pamong Praja adalah penegakan Qanun Nomor 3 Tahun 2007 tentang pengaturan dan pembinaan pedagang kaki lima. Pemerintah Kota berwenang untuk menata dan membina tempat USAha pedagang kaki lima sesuai dengan Rencana Tata Ruang Wilayah Kota. Penelitian ini bertujuan untuk menjelaskan peranan Satuan Polisi Pamong Praja Kota Banda Aceh dalam menata dan membina pedagang kaki lima dan menjelaskan faktor-faktor yang mempengaruhi pengaturan dan pembinaan yang dilakukan oleh Satuan Polisi Pamong Praja terhadap pedagang kaki lima di Kota Banda Aceh. Metode Penelitian menggunakan pendekatan hukum empiris. Hasil penelitian menunjukkan bahwa Satuan Polisi Pamong Praja Kota Banda Aceh telah berusaha mengatasi permasalahan ketidakteraturan pedagang kaki lima dengan melakukan penataan, penertiban dan pembinaan serta pengawasan terhadap pedagang kaki lima yang masih berjualan di tempat yang sudah dilarang beraktifitas dan memindahkan para pedagang kaki lima ketempat relokasi yang telah ditetapkan. Namun Kenyataannya pedagang kaki lima kembali berjualan di bahu jalan dan trotoar, karena pedagang kaki lima beranggapan akan lebih mudah dijangkau oleh pembeli dan mendapatkan keuntungan yang besar. Hal tersebut dipengaruhi oleh faktor internal berupa sumber daya manusia, sarana dan prasarana dan perangkat hukum belum tersedia. Sedangkan faktor eksternal meliputi tingkat kesadaran pedagang kaki lima masih kurang dan tingkat koordinasi antar lintas sektoral kurang mendapat dukungan. One of the existences of the Municipal Police authorities is enforcing Qanun Number 3, 2007 on the Regulation and Guiding for Street Vendors. The Government has power to regulate and manage street vendors based on the municipal spatial planning. This research aims to explore the roles of the Municipal Police in making public order and guiding the street vendors, to explain factors influencing the regulation and guidance done by the Municipal Police towards the street vendors in Banda Aceh. The research method used is the empirical legal research. The research shows that the municipal police of Banda Aceh has been striving to overcome the problems of troubles of the vendors by organized, guiding and supervising the vendors who are still trading at the forbidden places for it and moving them to the relocated spaces that has been made. Nevertheless, they are coming back to trade at the forbidden places namely, vendor places as they are assuming that by trading at the places and the vendors it will be easier to sale and to get buyers and get profit bigger. Some obstacles are influencing it, namely; internal factors that human resource capacity, infrastructures and the absence of laws. Meanwhile, the external factors are comprising the level of awareness/the obedience of the vendors themselves which is lack and the inter-sectors coordination that is lack of support

Determination of the Nucleotide Sequence of a Thermostable Xylanase Gene from Bacillus Coagulans ST-6

PBNXI is a recombinant plasmid containing vector plasmid pUC19 and a 2.6 kb fragment of Bacillus coagulans ST-6 genomic DNA which contains a xylanase gene. PBNX2 is another recombinant plasmid with the same insert DNA but in a pUC 18 vector. Both plasmids expressed xylanase activity when grown on RBB-Xylan agar plates. Preliminary to nucleotide sequencing, the recombinant plasmids were modified using restriction enzyme deletion to remove a segment of the insert DNA. The original insert DNA which was 2.6 kb was successfully reduced to a 0.8 kb and a 1.8 kb fragment in pBNXIA and pBNX2A respectively. The deletion was done using restriction endonuclease Sail and the resulting deletion mutants together with the original clones were used to determine the nucleotide sequence of the xylanase gene. By primer walking, 1420 bp of the forward sequence was obtained where an open reading frame (ORF) was found at 544 bp of the insert DNA. This 630 bp frame was preceeded by the putative E.coli - 10 and -35 promoters. No sequence corresponding to the signal peptide was found in this sequence. The open reading frame (ORF) was translated into a peptide of 2 1 0 amino acid residues. This protein belonged to Family G 11 of the Glycosyl Hydrolase family and had 59% homology with Bacillus stearothermophilus xylanase and 54% homology with xylanase from Aeromonas caviae. Eleven out of 20 completely conserved amino acids in this family were also conserved in this sequence and two conserved glutamate residues, E 104 and E 186 were directly involved in the enzyme's acid-catalytic mechanism. Secondary structure prediction showed that this enzyme consisted of two a-helices and 10 B-strands. Phylogenic studies showed that the primary structure of the enzyme was most closely related to Bacillus pumilus xylanase's primary structure. The analysis of the deduced amino acid sequence showed that there were five cysteine residues in this sequence compared to none in four other mesophilic xylanases. These cysteine residues can form internal disulfide bonds among themselves which can increase the stability of the protein. Analyzing the predicted secondary structure, an extra a-helical structure which is a more stable secondary structure was observed in comparison to other mesophilic xylanases. These two factors namely the presence of cysteine residues and the extra a-helical structure may have an important role in determining the thermo stability of this enzyme

Flame propagation and burning rates of methane-air mixtures using schlieren photography

Different methodology have been shown to produce different results for Markstein length and laminar burning velocity of methane-air mixture. This study attempts to determine the aforesaid parameters using the newly developed closed vessel combustion chamber with Schlieren photography. Markstein length and burning rate of methane-air mixture was determined under the initial pressure of 1 atm, temperature range of 298-302K and equivalence ratio range of 0.7-1.3. Experiments were performed in a centrally ignited 29.16L cylindrical constant volume combustion chamber. Ignition energy was set at 25mJ for each experiment. The images of spherically expanding flame were recorded using Schlieren photography technique at a speed of 2000 frame per second. Analysis of the flame area yield flame radii from which the flame speed and stretch rate could be obtained. These parameters would allow the determination of Markstein length and burning rate of the flame. Results show that Markstein length magnitude increases proportionally with equivalence ratio with a magnitude ranging from 0.125cm to 0.245cm. Maximum burning rate occurs at equivalence ratio of 1.1 with a magnitude of 0.366 m/s. Flame of each equivalence ratio also exhibits fluctuation arising from acoustic disturbance. This disturbance becomes more apparent at higher equivalence ratio