Abstract: In this paper we show the method Ψ to  estimate the structure and parameters of a non-lienar function of real value ƒ(.;Ɵ):Ɽn→Ɽ from a data set {(x1, x2, …, xj, …, xn,; y1)}i=m i=n taken from that function. The technique Ψ is based in the Holland’s genetic algorithm, this employ the genetic operations of selection, crossover and mutation. But unlike this, the individuals are dynamic structures called trees, allowing its size can grow without restrictions and these ones can become a better representation of the desired response. The experimentation shows that the method is efficient for both linear and nonlinear functions as well as for multivaried cases.

Abstract: X-ray fluorescence analysis is a powerful analytical tool for the determination of almost all the elements present in a sample. The aim of this paper was to study the X-ray fluorescence emissions from some fish tissue samples. The excitation source used was an annular radioactive source of Am-241 and the X-ray fluorescence from the sample were counted using a high purity Germanium (HPGe) detector. The spectra obtained were analyzed using a Multi-Channel Analyzer-3 analyzer and Microsoft Excel. Seven fish samples of Indian Mackerel were bombarded with Am-241 photons without any sample preparation. Each data were collected for four hours. The X-ray fluorescence spectra from these samples were complex due to the presence of natural tissues of the fish. From the spectra obtained, there were some trace elements suggested to be present in the samples. The possible trace elements present in the sample were Manganese (Mn), Iron (Fe), Rubidium (Rb), Niobium (Nb), and Molybdenum (Mo). The presence of these trace elements might due to the essential nutrition of the fish.

Abstract: This article presents variables and their respective impacts on the continuous improvement (CI) of a Brazilian electric company. In the case study conducted, a measuring instrument verified which CI organic behaviors were noticed by employees. The resulting data from these measurements were analyzed through factorial and descriptive examination methods. The factorial analysis identifies the four most important factors (abilities) that boost the organization into CI practices. The most significant one is the Commitment to the CI, that represents 25.4% of impact in the factorial model that impersonates the CI, followed by: Encouragement of the CI process (17.5%), Understanding of the CI meaning (16.9%); and Analyzing the CI (13.9%). The descriptive analysis indicates that the ability less perceived by the interviewees is the Encouragement of the CI process, with a 66.3% perception, and that the most perceived one is the Commitment to the CI, with 78.6%.

Abstract: Mount Bromo in East Java, Indonesia is erupting from 23 November 2021 and ejects ash with a maximum height of 1,500 meter and throws lava as high as 50-300 meters from the crater. In any eruptions the presence of natural radioelements is evident with high concern to affect the human health living near the volcano. This survey was aimed to determine the levels of radiation from the volcanic ash. We measured radiation dose rate, soil gamma-ray concentration, soil heavy metals contents and dust/ash concentration at four spots along the volcano’s caldera located at the village of Cemorolawang, District of Probolinggo just 2 km east of the crater. It was revealed that the radiation exposure rate was 14-16 μR/hr and the concentrations of K-40, Ra-226 and Th-232 were 760.8±84.6 Bq/kg, 31.9±4.2 Bq/kg and 57.0±6.8 Bq/kg, respectively. We also found that the concentra-tion of the particulate (PM10) was 52.9±5.1 μg/m3.

Abstract: Bachtiar (2009) and Bachtiar and James (BJ, 2012) proposed a new kinematic dynamo model called by Quasipas model. Quasipas flow is a modification of Pekeris, Accad, and shkollar flow. They proposed this flow in their effort to find planar velocity dynamos. In this work, we revisited the fully planarized version of Quasipas model. Based on the results of Bachtiar (2009) and BJ (2012), we tried to increase the portion of planarized poloidal part of this flow. We suspected that planarized poloidal part plays an important role in improving the magnetic field’s rate. We found that the magnetic field’s rate of fully planarized Quasipas has improved, however we could not find any successful dynamo.

Abstract: Asbestos fibre has been used as traditional base material in brake pads manufacture, but due to its health hazard, non-renewability, cost, non-biodegradability and difficulty in processing, its replacement has been sought. For the purpose of improving their properties, the fibres were retted, bleached and modified using mercerization, acetylation and semi-carbonisation methods to obtain three modified fibres in addition to the crude fibre. The four fibre types (crude, mercerised, acetylated and semi-carbonised) were evaluated for moisture absorption, density and porosity. Brake pads were produced from each of the four fibre types (each 15 % by weight) using a randomised factorial experimental design (1x 3 x 3), where the concentrations of the polyester (15 %, 20 % and 25 % by weight ) and filler(70 %, 65 % and 60 % by weight) were used. These materials or ingredients were mixed at 600 rpm for 5 minutes and then hot pressed at 175 0C under a moulding pressure of 32.5 MPa, which was held for 1 minute. A total of 36 samples of kenaf brake pads were produced and evaluated. Comparison among treatment means using the least significance difference (LSD) showed that at 20 % of polyester, water absorption in crude, mercerized, acetylated and semi-carbonized samples was not significantly different when 65 % weight of filler changed to 60 % by weight but the water absorption was significantly different when polyester changed from 20 % to 25 %. Also, the performance evaluation results indicated that  kenaf brake pads have high percentage of water absorption capacity, porosity and density with an average value of 0.067 g, 38 %  and 2.984 g/cm3 respectively than all the samples investigated.

Abstract: In this paper, we studied the temperature  and the magnetic field distribution in the infinitely long, eccentric tube carrying a steady, axial current and placed parallel to an infinite line current. Numerical example and graphs are presented for the temperature in the medium and for the magnetic field components in the region between the two cylinders is considered. The distance between the tube and the line current is let to vary and the results are discussed.. Numerical results are given and illustrated graphically.

Abstract: In this paper, we have applied the method of averaging to obtain periodic solutions of some nonlinear differential equation (NLDE). Then we have determined the averaging system to obtain the stability of periodic solution of NLDE. And the main result is the following proposition: The butterfly type catastrophe occurs in case of NLDE of fifth degree.

Abstract: Ampelocissus cavicaulis bast fibres were extracted from the young plant stems using water retting extraction procedure, and the resulting fibres were uniform with almost circular cross-sections. Phytochemical analysis revealed the presence of residual tannins, alkaloids, steroids, glycosides, and proteins, with the absence of free reducing sugars and flavonoids. Further analysis revealed the quantity of tannins, alkaloids and steroids to be 0.01±0.002, 6.40±0.28 and 0.03±0.004%w/w respectively. Lipophilic and alcoholic extractives obtained using soxhlet   technique with n-hexane / methanol as extracting solvents were found to be 1.96%w/w and 9.21%w/w respectively.  Moisture and ash content were found to be 5.60± 0.071%w/w and 2.88±0.90%w/w respectively. Structural component on %w/w basis shows that cellulose is 38.66±1.15%, acid insoluble lignin 33.21±2.76%, hemicellulose 25.91±1.29%, acid soluble lignin 1.47±0.01%, and the acid soluble lignin derived product-vanillic, p-coumaric and ferulic acids were found to be 1.346±0.022%w/w, 0.034±0.02%w/w and 0%w/w respectively. Cellulose lignin ratio is 1.16. The physical and mechanical parameters of the fibre determined include diameter 0.9174mm, tensile   strength   238.28MPa,   percentage elongation 3.0 % and Young’s modulus 3971.33MPa. The results obtained show that   A. cavicaulis   lignocellulose  bast  fibre has comparable properties with other natural fibres and some synthetic fibres.

Abstract: Water volume quantity may overflow on the surface not only due to natural phenomena, but also because water is less or no longer able to become absorbed into the soil and just flowed on the surface, flooding and damaging the region in its path. This study aims to analyze the influence of rainfall intensity variations and its relationships towards the percolation, which the observe rainfall intensity variations in this study are equal to 120 mm /hour, 275 mm /hour, and 450 mm/hour againts variations of soil density 40%, 60%, 80% for the original soil and soil with  variations of sand content 0%, 25%, 50% in a normal type rain and torrential rain, with solum shallow soil depth (25 cm), without vegetation, and without slope. This study is done by measuring the intensity of rainfall using a rainfall simulator which was designed in such a way so it can obtain the rainfall intensity which is determined on soil samples that had been prepared in the test bucket with a thickness of 25 cm sample. The results showed that the highest percolation value is equal to 1.47 x 10-8 m3/sec for 120 mm/h  of the rainfall intensity on 40% of soil density with 50% of sand content. The highest runoff values is equal to 3.75 x 10-8 m3 for 450 mm / h of rainfall intensity at 0% of soil density and 80% of sand content.