Journal of Mathematical and Fundamental Sciences
Not a member yet
737 research outputs found
Sort by
Magnetic and Electrical Properties of Leachate
Get PDFHeavy metals content as well as magnetic and electrical properties of leachate from Sarimukti, West Java were studied in an attempt to seek correlation between heavy metals content and magnetic/electrical properties. Such correlation is expected to open the way for the use of magnetic/electrical properties as proxy indicators for the concentration of heavy metals in the leachate. The number of leachate samples studied is 21; 15 were taken spatially at depth of 1 m while the remaining 6 samples were taken vertically at a particular point. Measurement results showed that the heavy metals content in the leachate has a smaller concentration, except for Fe. The correlation between magnetic susceptibility and heavy metals content was found to be not so significant. The best correlation coefficient between magnetic susceptibility with heavy metals in leachate was found in Zn. Correlation between electrical conductivity and heavy metal is also not so significant, except for Zn and Cd. The use of magnetic properties as proxy indicator for heavy metals content in leachate is plausible provided that the magnetic susceptibility exceeds certain threshold value. Correlation between magnetic susceptibility, electrical conductivity and heavy metal content would be good if each quantity has a large value
Seismogram Analysis of C052198B Earthquake, Minahasa at Observatory Stations in Australia
Get PDFThe earth structure between the Minahasa earthquake, coded as C052198B, and observatory stations in Australia has been investigated through analysis in the time domain of three-component seismograms. The synthetic seismograms are constructed from an earth model, the CMT solution of the earthquake and station locations. The calculation is based on the GEMINI method, and the corner frequency is set at 20 mHz. Using deconvolutions of the station instruments responses, the measured and synthetic seismogram can be compared with the same units. The seismogram comparison indicates discre-pancies between recorded data and synthetic seismograms calculated from the anisotropic PREM model, in the travel times of Rayleigh and Love surface wave, as well as the S and core reflected ScS and ScS2 body waves. Discrepancies of Love wave travel time and the number of oscillations are explained by changes in the crustal velocity model and by setting the positive gradient of bh in the upper mantle. While for Rayleigh waves and arrival times of body waves, corrections to the zero order coefficients of b are needed at layers in the mantle. The interpretation of the results of the waveform analyses indicates strong anisotropy in the upper mantle. The anisotropy also occurs, to a lesser extent, at layers beneath the upper mantle
The Use of Biofiltration Technology and 3-dimensional Cubical Bamboo Shelters for Nursery Phase Productivity Improvement of Giant Freshwater Prawns
Get PDFThis experiment was aimed at finding out the effects of usingnitrifying bacteria and Chlorella sp. and the application of a differing number of 3-dimensional cubical bamboo shelters for enhancing the growth performance of Giant Freshwater Prawns (Macrobrachium rosenbergii de Man) during the nursery phase in an indoor system. During 28 days of culture, treatment II (application of 4 shelters ~40% culture volume occupation) resulted in better prawn growth and culture performance compared to control (no shelter application) (p<0,05). At the end of the experiment, treatment II showed the highest biomass, specific growth rate, mean body weight and length of prawns with (1.96+0.05) g.cage-1, 8.24% BW.day-1, (2.18+0,89) g and (6.50+0.91) cm, respectively. However, these results were not significantly different compared to treatment I (application of 2 shelters ~20% culture volume occupation). The survival rate after treatment I and II (treatment I=90%, and treatment II=92%) was significantly higher compared to control (78%). During the experiment the increase of the concentration of ammonium and nitrate was controlled by the addition of nitrifying bacteria and microalgae, which can keep the microbial loop between ammonium reduction by bacteria and nitrate uptake by microalgae in balance. The addition of nitrifying bacteria and microalgae, and the availability of 40% bamboo shelter occupation in the culture can improve prawn culture productivity
Domain Motion in 3-isopropylmalate dehydrogenase: A Strategy to Enhance its Thermal Stability
Get PDFIn order to elucidate the thermal properties of Thermus thermophilus 3-isopropylmalate dehydrogenase, mutant structures with mutations at the C-terminus were compared with each other. The structural movement can be anticipated from the structural changes among mutants in regions of a minor groove and pillar. Our previous studies revealed that the open-close movement of the active site groove antagonizes to that of the minor groove (like a paperclip) and the thermostability of the enzyme increases when the active site groove is closed. In the present study, it is shown that the motion of the enzyme mainly occurs in the first domain and strand D in the pillar structure is a hinge-bending region of the movement. The motion of the first domain to expand the minor groove may close the active site groove suggesting a mechanism for the enhanced thermal stability of 3-isopropylmalate dehydrogenase
Expanding Super Edge-Magic Graphsâ
Get PDFFor a graph G, with the vertex set V(G) and the edge set E(G) an edge-magic total labeling is a bijection f from V(G)UE(G) to the set of integers {1,2,...., |V(G)|+|E(G)} with the property that f(u) + f(v) +f(uv) = k for each uv elemen E(G) and for a fixed integer k. An edge-magic total labeling f is called super edge-magic total labeling if f(E(G)) = {|V(G)+1, |V(G)+2,....., |V(G)+E(G)|}. In this paper we construct the expanded super edge-magic total graphs from cycles C, generalized Petersen graphs and generalized prisms
Pemodelan Hubungan Hujan, Limpasan dan Kapasitas Erosi pada Suatu DAS yang Masuk ke Palung Sungai
Get PDFThis paper present the results of the mathematical model study on the relation between rain fall pattern, surface run off flows and land erodibility of a catchment area and river sedimentation. The influences of catchment area characteristics such as land use, soil behavior, topography condition and other related physical condition is encountered. Surface flow assessment is done at each sub catchment area by using mathematical model named ANSWER. Case study on Cipeles Catchmen area had shown that land use and rain fall pattern are the main parameter. Good agreement between model result and observation is shown on surface run off flow and sediment pattern, but there is still significant inaccuracy in its magnitude. This inaccuracy could be minimized not only by improving the model but also using a better data calibration, such as highly correlated rain fall and river discharge data with catchment area land use condition
Analisis Sandi Diferensial terhadap AES, DES dan AE1
Get PDFSince 1977, DES officially became America encryption algorithm. And then this algorithm spreads over the world to be used in banking, financial industries, and economics. Because of the short of the key, in 2001, DES is replaced by AES. One of the most important problem in cryptology is how to prove the security of algorithm against cryptanalysis. In this paper, we will discuss differential attack to examine the security of DES, AES and AE1. AE1 is block cipher that we proposed. Although differential attack has been proposed since 1990, all of cryptographers in the world still use it to examine the strength of ciphers till now. Our contribution is providing a proof that AE1 can be resistant to differential attack and that our cipher is more secure than DES and AES against differential attack. Unfortunately, our cipher is slower than DES or AES
Correlation and Relativistic Effects on the Level Structure of Negative Ions of Atoms with Half-filled p Shell
No full textThe level structure for negative ions (anions) of some atoms with half-filled p shell have been investigated using the multiconfiguration Hartree-Fock method with Breit-Pauli relativistic effects (MCHF+BP method). Thus, we have performed a systematic calculation including correlation and relativistic corrections for negative ions of these atomic systems. Investigations into the level structures of negative ions provide valuable insight into the fundamental problem of many-body motion. The correlation and relativistic effects in negative ions relative to neutral atoms and positive ions are greatly expected. In this work, we also discuss calculations for these effects in view of the MCHF+BP method
Effect of Chlorine Plasma Treatment on Electronic Properties of GIZO Thin Film Grown on SiO2/Si Substrate
Get PDFThe effect of chlorine plasma treatment on electronic properties of GIZO grown on SiO2/Si by RF magnetron sputtering was investigated using X-ray photoelectron spectroscopy (XPS), reflection electron energy loss spectroscopy (REELS), and secondary ion mass spectroscopy (SIMS). SIMS depth profiles indicated that the concentration of InO and ZnO on the surface was decreased after Cl2 plasma treatment. REELS data showed that the band gap increased from 3.4 to 3.7 eV. XPS showed that Ind5/2 and Zn2p3/2 shifted to the higher binding energies by 0.5 eV and 0.3 eV, respectively. These phenomena were caused by oxygen deficiency and hydrocarbon contamination reduction as indicated by Cl atom bonding with In and Zn cations that are present on the surface after Cl2 plasma treatment
Identifikasi dan Klasifikasi Sinyal EEG terhadap Rangsangan Suara dengan Ekstraksi Wavelet dan Spektral Daya
Get PDFIn this research the development of identification and classification technique of three wave components of EEG signal, named alpha, beta and theta, is considered. The technique is combination of wavelet transform and power spectral analysis. Wavelet transform was used to extract the wave components so it reduces the data without loss of the information. The wavelet transform also reduces the aspects of non-stationary of the EEG signal. The EEG's wave classification was based on the appearance of the wave, synchronization between symmetric hemispheres, and the wave energy dominance, in its frequency region. The EEG signals used in this research were obtained from 5 individually-independent subjects after 2.5 minutes sound stimulation. 10 sounds of music and 2 natural sounds were used as sound stimulation in this research. Then, 16 channels of EEG signals, obtained from every individual subject after a sound stimulation, were analyzed. The technique shows that the sound stimulation increases the appearance of the alpha wave by 75% and decreases beta and theta waves by 48% and 56%, respectively. Furthermore, the sound stimulations were used in the research to increase the synchronization balance between symmetric channels by 75%. In addition, this research shows that the signal extraction using wavelet packet provided small deviation and reduced non-stationary aspects, so that it improves the power spectral analysis used in the technique