Dynamics of DNA Bubble in Viscous Medium

The damping effect to the DNA bubble is investigated within the Peyrard-Bishop model. In the continuum limit, the dynamics of the bubble of DNA is described by the damped nonlinear Schrodinger equation and studied by means of variational method. It is shown that the propagation of solitary wave pattern is not vanishing in a non-viscous system. Inversely, the solitary wave vanishes soon as the viscous force is introduced.Comment: 4 pages. arXiv admin note: substantial text overlap with arXiv:1112.471

Nonlinear conformation of secondary protein folding

A model to describe the mechanism of conformational dynamics in secondary protein based on matter interactions is proposed. The approach deploys the lagrangian method by imposing certain symmetry breaking. The protein backbone is initially assumed to be nonlinear and represented by the Sine-Gordon equation, while the nonlinear external bosonic sources is represented by $\phi^4$ interaction. It is argued that the nonlinear source induces the folding pathway in a different way than the previous work with initially linear backbone. Also, the nonlinearity of protein backbone decreases the folding speed.Comment: 6 pages, 1 figur

Conformation changes and protein folding induced by \phi^4 interaction

A model to describe the mechanism of conformational dynamics in protein based on matter interactions using lagrangian approach and imposing certain symmetry breaking is proposed. Both conformation changes of proteins and the injected non-linear sources are represented by the bosonic lagrangian with an additional \phi^4 interaction for the sources. In the model the spring tension of protein representing the internal hydrogen bonds is realized as the interactions between individual amino acids and nonlinear sources. The folding pathway is determined by the strength of nonlinear sources that propagate through the protein backbone. It is also shown that the model reproduces the results in some previous works.Comment: 8 pages, Proceeding of the Conference in Honour of Murray Gell-Mann's 80th Birthday : Quantum Mechanics, Elementary Particles, Quantum Cosmology, Complexity (2011) 472-47

Determining the Number of Parallel RC Branches in Polarization / Depolarization Current Modeling for XLPE Cable Insulation

An important element in the electric power distribution system is the underground cable. However continuous applications of high voltages unto the cable, may lead to insulation degradations and subsequent cable failure. Since any disruption to the electricity supply may lead to economic losses as well as lowering customer satisfaction, the maintenance of cables is very important to an electrical utility company. Thus, a reliable diagnostic technique that is able to accurately assess the condition of cable insulation operating is critical, in order for cable replacement exercise to be done. One such diagnostic technique to assess the level of degradation within the cable insulation is the Polarization / Depolarization Current (PDC) analysis. This research work attempts to investigate PDC behaviour for medium voltage (MV) cross-linked polyethylene (XLPE) insulated cables, via baseline PDC measurements and utilizing the measured data to simulate for PDC analysis. Once PDC simulations have been achieved, the values of conductivity of XLPE cable insulations can be approximated. Cable conductivity serves as an indicator to the level of degradation within XLPE cable insulation. It was found that for new and unused XLPE cables, the polarization and depolarization currents have almost overlapping trendlines, as the cable insulation’s conduction current is negligible. Using a linear dielectric circuit equivalence model as the XLPE cable insulation and its corresponding governing equations, it is possible to optimize the number of parallel RC branches to simulate PDC analysis, with a very high degree of accuracy. The PDC simulation model has been validated against the baseline PDC measurements

Komunikasi Pembangunan Partisipatif Untuk Pemberdayaan Buruh Migran

: The profession of migrant worker in rural communities remains as the most promising job for better welfare. Participatory Rural Apprasial is used as the method, meanwhile the data is collected through FGD, interviews, observation, and documentation. The informants are former and potential migran workers in Sidaurip and Karangtawang village of Cilacap district. Using interactive analysis and SWOT, the results show that participatory development communication is important in planning and implementing empowerment program, to get the people involved to develop their village, including to choose to stay in the village instead of become migrant worker as the most important profession

Optimasi Formula Tablet Dispersible Ekstrak Daun Jambu Biji dengan Kombinasi Bahan Penghancur Croscarmellose Sodium dan Sodium Starch Glycolate

Khasiat dan keamanan daun jambu biji (Psidium guajava L.) sebagai antidiare telah diuji secara praklinik dan klinik. Bentuk sediaan yang ada saat ini kebanyakan susah ditelan, waktu disintegrasinya lama serta memiliki rasa dan bau yang kurang enak, sehingga perlu diformulasikan sediaan yang lebih akseptabel bagi anak-anak. Penelitian ini bertujuan untuk mengoptimasi formula tablet dispersible ekstrak air daun jambu biji menggunakan variasi bahan penghancur croscarmellose sodium (CCS) dan sodium starch glycolate (SSG) dengan metode simplex lattice design (SLD). Tablet dispersible dibuat 5 formula dengan metode granulasi kering yaitu formula I (100% CCS), II (75% CCS : 25% SSG), III (50% CCS : 50% SSG), IV (25% CCS : 75% SSG) dan V (100% SSG). Standarisasi ekstrak yang dilakukan meliputi uji organoleptik, susut pengeringan dan kromatografi lapis tipis (KLT). Tablet dispersible yang diperoleh, diuji sifat fisik keseragaman bobot, kerapuhan, kekerasan, waktu disintegrasi, waktu dispersi, waktu pembasahan serta KLT. Data dianalisis menggunakan software Design Expert® versi 7.1.4.0 untuk mendapatkan formula optimum. Hasil penelitian menunjukkan bahwa kombinasi bahan penghancur CCS-SSG mempengaruhi sifat fisik tablet. Semakin besar jumlah SSG maka semakin besar kekerasan, waktu disintegrasi, waktu dispersi dan waktu pembasahan tablet. Formula optimum yang diperoleh adalah formula dengan kombinasi 71% CCS dan 29% SSG