169 research outputs found

    Simplest Cubic Fields

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    Let Q(α)Q(\alpha) be the simplest cubic field, it is known that Q(α)Q(\alpha) can be generated by adjoining a root of the irreducible equation x3kx2+(k3)x+1=0x^{3}-kx^{2}+(k-3)x+1=0, where kk belongs to QQ. In this paper we have established a relationship between α\alpha, α\alpha' and k,kk,k' where α\alpha is a root of the equation x3kx2+(k3)x+1=0x^{3}-kx^{2}+(k-3)x+1=0 and α\alpha' is a root of the same equation with kk replaced by kk' and Q(α)=Q(α)Q(\alpha)=Q(\alpha')

    Feasibility Study of a Facility to Produce Injection Molded Parts for Automotive Industry

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    [EN] This study aims at the preliminary assessment in designing a complete stand-alone industrial facility to produce injection molded parts for the automotive industry. A draft design solution to allow the company to evaluate the capital investment was performed giving an estimated solution in project profitability. Proposed successive design steps were developed. It includes the definition of input data and information, quantity determination, plat layout diagrams, machine selection, selection of material handling equipment, plant layout design including space requirements of production centers, aísles, support functions. Moreover, the outdoor facility masterplan design is also proposed. Finally, investment calculation via cash flow analysis is calculated.Yudianto, A.; Tan, H.; Qu, Z.; Xue, Q.; Naveen, A.; Mushtaq, M.; Gopi, K. (2020). Feasibility Study of a Facility to Produce Injection Molded Parts for Automotive Industry. International Journal of Production Management and Engineering. 8(1):45-57. https://doi.org/10.4995/ijpme.2020.12360455781Al-Aomar, R. (2006). Capacity-constrained production scheduling of multiple vehicle programs in automotive pilot plant. International Journal of Production Research, 44(13), 2573-2604. https://doi.org/10.1080/00207540500521212Cagliano, A. C., Chiabert, P. (2018). Plant and manufacturing system lecture notes. Politecnico di Torino, Italy.Chingua, S. Nyemba, W. R., Boora, K., Mbohwa, C. (2019). Feasibility study of the materials handling and development of a sustainable conveying system in plastics recycling and manufacture. Procedia Manufacturing, 33, 383-390. https://doi.org/10.1016/j.promfg.2019.04.047Derhami, S., Smith, J. S., Gue, K. R. (2019). Space-efficient layouts for block stacking warehouse. IISE Transaction, 51(9), 957-971. https://doi.org/10.1080/24725854.2018.1539280Eksangsri, T., Jaiwang, T. (2014). Feasibility study on reuse of washed water in electronic industry: case study for flexible printed circuit board manufacturing in Thailand. Procedia Environmental Sciences, 20, 206-214. https://doi.org/10.1016/j.proenv.2014.03.027Fu, M., Kaku, B. K. (1997). Minimizing work-in-process and material handling in the facilities layout problem. IIE Transactions, 29, 29-36. https://doi.org/10.1080/07408179708966309Halil, F. M., Nasir, N. M., Hassan, A. A., Shukur, A. S. (2016). Feasibility study and economic assessment in green building projects. Procedia-Social and Behavioral Sciences, 222, 56-64. https://doi.org/10.1016/j.sbspro.2016.05.176Hazaras, M. J., Swartz, C. L. E., Marlin, T. E. (2013). Industrial application of a continuous-time scheduling framework for process analysis and improvement. I&EC research Industrial & Engineering Chemistry Research, 53, 259-273. https://doi.org/10.1021/ie4006904Hwang, D. K., Cho, K., Moon, J. (2019). Feasibility study on energy audit and data driven analysis procedure for building energy efficiency: bench-marking in Korean hospital buildings. Journal Energy 12(15), 3006. https://doi.org/10.3390/en12153006Jung, S., Ng, D., Ovalle, C. D., Roman, R, V., Mannan, M. S. (2011). New approach to optimizing the facility sitting and layout for fire and explosion scenarios. I&EC research Industrial & Engineering Chemistry Research, 50, 3928-3937. https://doi.org/10.1021/ie101367gKingenberg, W., Boksma, J. D. (2010). A conceptual framework for outsourcing of material handling activities in automotive: differentiation and implementation. International Journal of Production Research, 48(16), 4877-4899. https://doi.org/10.1080/00207540903067177Kovàcs, G. (2019). Layout design for efficiency improvement and cost reduction. Bull. Pol. Ac.: Tech., 67(3), 547-555. https://doi.org/10.24425%2Fbpasts.2019.129653Ma, T., Yang, H., Lu. L., Qi, R. (2017). Feasibility study of developing a zero-carbon-emission green deck in Hong Kong. Energy Procedia 105, 1155-1159. https://doi.org/10.1016/j.egypro.2017.03.487Morgan, B., Hejdenberg, J., Krapels, S. H., Amstrong, D. (2018). DO feasibility studies contribute to, or avoid, waste in research? PLos ONE 13(4), e0195951. https://doi.org/10.1371/journal.pone.0195951Pòvoa, A. P. B., (2002). Optimal design and layout of industrial facilities: a simultaneous approach. Ind. Eng. Chem. Res, 41, 3601-3609. https://doi.org/10.1021/ie010660sSchaller, J. (2008). Incorporating cellular manufacturing into supply chain design. International Journal of Production Research, 46(17), 4925-4945. https://doi.org/10.1080/00207540701348761Stephens, M. P., Meyers, F. E., (2013). Manufacturing facilities design and material handling - fifth edition. Purdue University Press, West Lafayette, Indiana.Sun, L., Luan, F., Pian, J. (2015). An effective approach for scheduling of refining process with uncertain iterations in steel-making and continuous casting process. IFAC-PapersOnLine, 48(3), 1966-1972. https://doi.org/10.1016/j.ifacol.2015.06.376Yang, Z., Djurdjanovic, D., Ni, J. (2007). Maintenance scheduling for a manufacturing system of machines with adjustable throughput. IIE Transactions, 39, 1111-1125. https://doi.org/10.1080/0740817070131533

    Antihypertensive Activity of Aqueous-Methanol Extract of Berberis Orthobotrys Bien Ex Aitch in Rats

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    Purpose: To investigate the hypotensive potential of Berberis orthobotrys Bien Ex Aitch (Family: Berberidaceae) in both normotensive and hypertensive rats.Methods: Aqueous-methanol (70:30) extract of Berberis orthobotrys at doses of 25, 50, 75 and 100 mg/kg was evaluated for its effect on blood pressure and heart rate using non-invasive blood pressure measuring apparatus. After initial screening, 100 mg/kg dose that produced a maximum effect was selected for the antihypertensive study. Median lethal dose (LD50) and sub-chronic toxicity of the extract were also determined. Various biochemical parameters and organ weight were measured usingstandard procedures.Results: The extract produced a significant (p < 0.01) decrease in systolic blood pressure (SBP), mean blood pressure (MBP), diastolic blood pressure (DBP) and heart rate of normotensive rats at all test doses with maximum effect at 100 mg/kg. Similarly, a significant antihypertensive and negative chronotropic effect was observed in both hypertensive models. LD50 of the extract was 200 mg/kg in mice. The extract also exhibited a reduction (p < 0.05) in serum alanine transaminase (ALT), aspartate aminotransaminase (AST), alkaline phosphatase (ALP), triglycerides and low density lipoprotein (LDL) levels while a significant (p < 0.05) increase in high density lipoproteins (HDL) level was observed.Conclusion: It seems that the aqueous-methanol extract of Berberis orthobotrys possesses active compounds which may be responsible for the antihypertensive and negative chronotropic effects in rats.Keywords: Berberis orthobotrys, Antihypertensive, Egg feed diet, Blood lipid

    Hamiltonian Study of Improved U(1U(1 Lattice Gauge Theory in Three Dimensions

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    A comprehensive analysis of the Symanzik improved anisotropic three-dimensional U(1) lattice gauge theory in the Hamiltonian limit is made. Monte Carlo techniques are used to obtain numerical results for the static potential, ratio of the renormalized and bare anisotropies, the string tension, lowest glueball masses and the mass ratio. Evidence that rotational symmetry is established more accurately for the Symanzik improved anisotropic action is presented. The discretization errors in the static potential and the renormalization of the bare anisotropy are found to be only a few percent compared to errors of about 20-25% for the unimproved gauge action. Evidence of scaling in the string tension, antisymmetric mass gap and the mass ratio is observed in the weak coupling region and the behaviour is tested against analytic and numerical results obtained in various other Hamiltonian studies of the theory. We find that more accurate determination of the scaling coefficients of the string tension and the antisymmetric mass gap has been achieved, and the agreement with various other Hamiltonian studies of the theory is excellent. The improved action is found to give faster convergence to the continuum limit. Very clear evidence is obtained that in the continuum limit the glueball ratio MS/MAM_{S}/M_{A} approaches exactly 2, as expected in a theory of free, massive bosons.Comment: 13 pages, 15 figures, submitted to Phys. Rev.

    Behavior and Impact of Zirconium in the Soil–Plant System: Plant Uptake and Phytotoxicity

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    Because of the large number of sites they pollute, toxic metals that contaminate terrestrial ecosystems are increasingly of environmental and sanitary concern (Uzu et al. 2010, 2011; Shahid et al. 2011a, b, 2012a). Among such metals is zirconium (Zr), which has the atomic number 40 and is a transition metal that resembles titanium in physical and chemical properties (Zaccone et al. 2008). Zr is widely used in many chemical industry processes and in nuclear reactors (Sandoval et al. 2011; Kamal et al. 2011), owing to its useful properties like hardness, corrosion-resistance and permeable to neutrons (Mushtaq 2012). Hence, the recent increased use of Zr by industry, and the occurrence of the Chernobyl and Fukashima catastrophe have enhanced environmental levels in soil and waters (Yirchenko and Agapkina 1993; Mosulishvili et al. 1994 ; Kruglov et al. 1996)

    Counting on the mental number line to make a move: sensorimotor ('pen') control and numerical processing

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    Mathematics is often conducted with a writing implement. But is there a relationship between numerical processing and sensorimotor ‘pen’ control? We asked participants to move a stylus so it crossed an unmarked line at a location specified by a symbolic number (1–9), where number colour indicated whether the line ran left–right (‘normal’) or vice versa (‘reversed’). The task could be simplified through the use of a ‘mental number line’ (MNL). Many modern societies use number lines in mathematical education and the brain’s representation of number appears to follow a culturally determined spatial organisation (so better task performance is associated with this culturally normal orientation—the MNL effect). Participants (counter-balanced) completed two consistent blocks of trials, ‘normal’ and ‘reversed’, followed by a mixed block where line direction varied randomly. Experiment 1 established that the MNL effect was robust, and showed that the cognitive load associated with reversing the MNL not only affected response selection but also the actual movement execution (indexed by duration) within the mixed trials. Experiment 2 showed that an individual’s motor abilities predicted performance in the difficult (mixed) condition but not the easier blocks. These results suggest that numerical processing is not isolated from motor capabilities—a finding with applied consequences

    How land use/land cover changes can affect water, flooding and sedimentation in a tropical watershed: a case study using distributed modeling in the Upper Citarum watershed, Indonesia

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    [EN] Human activity has produced severe LULC changes within the Upper Citarum watershed and these changes are predicted to continue in the future. With an increase in population parallel to a 141% increment in urban areas, a reduction of rice fields and the replacement of forests with cultivations have been found in the past. Accordingly, LCM model was used to forecast the LULC in 2029. A distributed model called TETIS was implemented in the Upper Citarum watershed to assess the impact of the different historical and future LULC scenarios on its water and sediment cycles. This model was calibrated and validated with different LULCs. For the implementation of the sediment sub-model, it was crucial to use the bathymetric information of the reservoir located at the catchment's outlet. Deforestation and urbanization have been shown to be the most influential factors affecting the alteration of the hydrological and sedimentological processes in the Upper Citarum watershed. The change of LULC decreases evapotranspiration and as a direct consequence, the water yield increased by 15% and 40% during the periods 1994-2014 and 2014-2029, respectively. These increments are caused by the rise of three components in the runoff: overland flow, interflow and base flow. Apart from that, these changes in LULC increased the area of non-tolerable erosion from 412 km(2) in 1994 to 499 km(2) in 2029. The mean sediment yield increased from 3.1 Mton -yr(-1) in the 1994 LULC scenario to 6.7 Mton-yr(-1) in the 2029 LULC scenario. An increment of this magnitude will be catastrophic for the operation of the Saguling Dam.This study was partially funded by the Spanish Ministry of Economy and Competitiveness through the research projects TETISMED (CGL2014-58,127-C3-3-R) and TETISCHANGE (RTI2018-093717-B-I00). The authors are also thankful to the Directorate General of Higher Education of Indonesia (DIKTI) for the Ph.D. funding of the first author.Siswanto, SY.; Francés, F. (2019). How land use/land cover changes can affect water, flooding and sedimentation in a tropical watershed: a case study using distributed modeling in the Upper Citarum watershed, Indonesia. Environmental Earth Sciences. 78(17):1-15. https://doi.org/10.1007/s12665-019-8561-0S115781
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