Graphical Integration Method Research Articles

ANALISIS ENDAPAN SEDIMEN DASAR BENDUNG KAMUN TERHADAP TINGGI MERCU DAN KEHILANGAN DEBIT AIR SALURAN INDUK CILUTUNG BARAT KABUPATEN MAJALENGKA

Kamun Dam is a permanent weir with its water intake in the Cilutung River Basin (DAS). One major factor affecting water reduction at the weir is sediment settling at the upstream base. Effective and efficient management is crucial for irrigation water and networks to maximize benefits. Water loss from primary to secondary and tertiary channels negatively impacts irrigation system performance. The water flow through weirs and structures with varying discharges influences the water surface profile and its characteristics.This research aimed to determine the water level, total sediment transport capacity, water discharge loss in the West Cilutung main channel, and the water surface profile shape. The data comprised primary data from field investigations and secondary data, including average discharge data from 2008-2017.Water level analysis was performed using hydraulic formulas and the Trial and Error method. The highest water level recorded was 0.74 m in April, and the lowest was 0.22 m in August. Sediment transport analysis, using the Meyer-Peter Muller method, estimated that it would take approximately 13 years to fill the upstream of Kamun Dam with 1,436,470.04 m³ of sediment, without dredging, given a river width of 74.15 m and height of 3 m. Water discharge loss analysis, using the inflow and outflow method, showed Qrenc results from BLK.1-BLB.1 at 0.06 m³/sec and Qactual at 0.27 m³/sec. The water surface profile analysis, using the graphical integration method, yielded Qrenc results for profile I f(y) = 4786 and Qactual results for profile I f(y) = 789

Estimation of Activity and Molar Excess Gibbs Energy of Binary Liquid Alloys Pb-Sn, Al-Sn and In-Zn from the Partial Radial Distribution Function Simulated by Ab Initio Molecular Dynamics

For the present, it is difficult to obtain thermodynamic data for binary liquid alloys by experimental measurements. In this study, the molecular dynamics processes of the binary liquid alloys Pb50-Sn50, Al50-Sn50, and In50-Zn50 were simulated by using the ab initio molecular dynamics (AIMD) principle, and their partial radial distribution functions (PRDF) were obtained at different simulation steps. Combined with the relevant binary parameters of the Molecular Interaction Volume Model (MIVM), Regular Solution Model (RSM), Wilson Model, and Non-Random Two-Liquid (NRTL) models. The integral terms containing the PRDF were computed using the graphical integration method to obtain the parameters of these models, thus estimating their activity and molar excess Gibbs energy. The total average relative deviations (ARD) of the activity and molar excess Gibbs energy estimates of the four models for the binary liquid alloys Pb50-Sn50, Al50-Sn50, and In50-Zn50 at full concentration when the PRDF is obtained by the symmetry method are MIVM: 21.59% and 59.35%; RSM: 21.63% and 60.27%; Wilson: 24.27% and 86.7%; NRTL: 23.9% and 83.24%. When the PRDF is obtained by the asymmetric method: MIVM: 22.86% and 68.08%; RSM: 32.84% and 68.66%; Wilson: 25.14% and 82.75%; NRTL: 24.49% and 85.74%. This indicates that the estimation performance of the MIVM model is superior to the other three models, and the symmetric method performs better than the asymmetric method. The present study also derives and verifies the feasibility of Sommer’s equation for estimating the molar excess Gibbs energy and activity of binary liquid alloy systems in the Miedema model by using different equations of enthalpy of mixing versus excess entropy given by Tanaka, Ding, and Sommer. The total ARD of Tanaka, Ding, and Sommer’s relational equations in the Miedema model for estimating the activities and molar excess Gibbs energies of the binary liquid alloys Pb-Sn, Al-Sn, and In-Zn are 3.07% and 8.92%, 6.09% and 17.1%, and 4.1% and 14.77%. The results indicate that the estimation performance of the Miedema model is superior to the other four models.

Comparison between Methods for Estimating Length of G.V.F. Curves in Mild Circular Open Channel with Experimental Length

Abstract- A gradually varied flow computation is important for the design of water structures. To design dimensions of channels, examining the depth of water in a gradually varied flow is required. In this study, experiments study were performed to evaluate different methods for calculating the lengths of gradually varied flow curves in mild slope circular open channel. The study was performed in a circular flume with an inner diameter equal to 24.40 cm with a mild slope equal to 0.00083 for different discharges from 2.38 l/sec to 14.08 l/sec. The objective of this study is to compare water surface profiles resulting from experimental measurements with the water surface profiles computed from graphical integration method), direct step method, and Runge-Kutta method for two gradually varied flow curves M3 and M2. The graphical integration method has a minimum percentage error of -0.18% and a maximum of -8.68% for M3 curves, while it has a minimum percentage error of 0.78% and a maximum of 8.37% for M2 curves. The direct step method has a minimum percentage error of 0.04% and a maximum of 9.34% for M3 curves while having a minimum percentage error of 0.91% and a maximum of 8.25 for curves M2 curves. For the Runge-Kutta method, the maximum error in water surface for all runs is -5.00% for M3 curves and 1.95% for M2 curves. The Runge-Kutta method perfectly fits in the circular channels.

Strength and energy exchange of deep sandstone under high hydraulic conditions

To investigate the influence of confining pressure and pore water pressure on strength characteristics, energy storage state and energy release intensity at peak failure of deep sandstone, a series of triaxial compression tests under hydraulic coupling conditions are carried out. By analyzing the process of rock deformation and failure, the stress thresholds of the rock are obtained. The change trend of total energy density, elastic energy density and dissipated energy density of deep sandstone in the pre-peak stage is obtained by the graphical integration method. By comparing the dynamic energy storage level of rocks under different confining pressures, the influence of pore water pressure on the energy dissipation at stress thresholds of crack closure stress, crack initiation stress, crack damage stress and peak stress is analyzed. Based on the ratio of pre-peak total energy density to post-peak total energy density, the interaction mechanism of confining pressure and pore water pressure for the rock burst proneness of deep sandstone is studied. The experimental results show that the peak stress of sandstone increases with the increase of confining pressure, while the existence of pore water pressure can weaken the peak stress of sandstone. In the stress stage from crack closure stress to peak stress, the dynamic energy storage level of rock presents a trend of the inverse “check mark”. Meanwhile, the larger the confining pressure, the higher the energy storage level of rock. However, the pore water pressure increases the degree of energy dissipation of rock and reduces the energy storage capacity of rock, and the degree of dissipation is linear with pore water pressure. The increase of confining pressure aggravates the instability and failure of deep sandstone, while pore water pressure has the opposite effect. The research results will provide necessary data support for the stability analysis of rock mass excavation in sandstone stratum under high stress and high pore water pressure.

Kinetics and Thermodynamics of Adsorption–Desorption of Water Vapors on Microsized Powders of Layered Molybdenum Disulfide

Experimental kinetic data on the adsorption and desorption of water vapors on molybdenum disulfide in relative humidity ranges of the gas phase from zero to 100% are presented. Microsized layered molybdenum disulfide powders (manufactured by Climax Molybdenum Co., USA) were used in the experiment. The adsorption–desorption kinetics of water vapors was studied by the gravimetric method. In the continuous automatic mode, the weight changes in the test sample and the process rate were recorded. An air stream with a relative humidity of 100% was used for water vapor adsorption. Desorption was studied under decrease in the partial pressure of air flow water vapors to 55% of the relative humidity in isothermal and nonisothermal conditions (temperature increase and decrease in the range 20–130°C). The time dependence of the adsorptive process of water vapors in a flowing system with 100% humidity of the gas phase is close to parabolic. The dependence of adsorption on water vapor pressure (V = f(Pi) is S-shaped with the bend point in the region of transition to condensation-induced filling of absorption volumes. The desorption rate exceeds the adsorption rate. The adsorption potential theory of Polanyi, Dubinin, and Radushkevich was used to assess the bonding energy between the water molecules and nonuniform MoS2 porous structure. The change in the adsorptive forces and the Pi/Ps ratio depending on the change in adsorbate volume were characterized. Adsorption isotherms for water vapors were plotted at 30 and 50°C. The graphical integration method was applied to determine the differential rate of forming the water adsorption volumes (dVi) at water partial pressures 0 < Pi < 5 kPa. The kinetic features of the stepwise process are shown to depend on the potential energy of interaction between the adsorbed volumes and adsorbent. The nature of the adsorption process does not change in temperature changes. The coordinates of intensive formation of the adsorption volume changed towards increase in the partial pressure of water vapors.

Investigation on the Linear Energy Storage and Dissipation Laws of Rock Materials Under Uniaxial Compression

To investigate the energy evolution characteristics of rock materials under uniaxial compression, the single-cyclic loading–unloading uniaxial compression tests of four rock materials (Qingshan granite, Yellow sandstone, Longdong limestone and Black sandstone) were conducted under five unloading stress levels. The stress–strain curves and failure characteristics of rock specimens under the single-cyclic loading–unloading uniaxial compression tests basically corresponded with those of under uniaxial compression, which indicates that single-cyclic loading–unloading has minimal effects on the variations in the loading–deformation response of rocks. The input energy density, elastic energy density and dissipated energy density of four rocks under five unloading stress levels were calculated using the graphical integration method, and variation characteristics of those three energy density parameters with different unloading stress levels were explored. The results show that all three energy density parameters above increased nonlinearly with increasing unloading stress level as quadratic polynomial functions. Meanwhile, both the elastic and dissipated energy density increased linearly when the input energy density increased, and the linear energy storage and dissipation laws for rock materials were observed. Furthermore, a linear relationship between the dissipated and elastic energy density was also proposed. Using the linear energy storage or dissipation law, the elastic and dissipated energy density at any stress levels can be calculated, and the internal elastic (or dissipated) energy density at peak compressive strength (the peak elastic and dissipated energy density for short) can be obtained. The ratio of the elastic energy density to dissipated energy density with increasing input energy density was investigated using a new method, and the results show that this ratio tends to be constant at the peak compressive strength of rock specimens.

Aplikasi Perhitungan Profil Aliran dengan Metode Integrasi Grafis dan Tahapan Langsung pada Saluran Berpenampang Trapesium

Dalam suatu proyek bendungan pasti dibutuhkan perhitungan yang digunakan untuk membantupembangunan. Perhitungan yang dibuat ini merupakan perhitungan profil aliran dengan metodaintegrasi grafis dan metoda tahapan langsung. Tujuan perhitungan profil aliran untuk membantudalam pembangunan bendungan agar aliran sungai mengalir dengan baik menuju bendung. Tujuandari pembuatan aplikasi ini untuk mempermudah perhitungan secara manual. Aplikasi yang dibuatini menggunakan bahasa pemrograman Java dengan database MySQL. Sumber data yangdiperoleh dari literatur dan pengujian aplikasi dengan membandingkan perhitungan aplikasi danperhitungan secara manual.

Field test for hydraulic turbine discharge and efficiency based on current-meter method

Hydraulic turbine efficiency is one of the important indicators during acceptance inspection. One of the difficulties in field test for hydraulic turbine efficiency is discharge measurement. Current-meter method is widely applied because of its intuition and accuracy. Through test in a Francis turbine with a circular penstock, turbine discharge and efficiency calculation based on current-meter method is discussed in this paper. Test results indicate that integration step-size needs to be small enough to get accurate discharge in graphical integration method. Uncertainty estimation is important and requisite in field test for turbine efficiency, which reflects the actual reliability of test results.

Direct work exchanger network synthesis of isothermal process based on improved transshipment model

Abstract Research on work exchange between high and low-pressure streams to reduce consumption of relatively expensive mechanical energy has great significance for improving energy efficiency in chemical plants. A novel methodology for the synthesis of direct work exchanger network of isothermal process is first proposed in this article. It is developed based on an improved transshipment model in a linear programming formulation. Two heuristic strategies and six matching rules that explicitly assist identifying feasible match between high and low-pressure streams are proposed. The former strategy is to construct intermediate pressures of low-pressure streams for solving pressure constraints of stream matches. The latter one is applied to find more feasible matches for further reducing both utility consumption and the number of work exchangers. Compared with solutions gained by graphical integration method, the presented method is proved to be more efficient by two examples where specific utility consumption is reduced by 23.4% and 17.6%, respectively.

A graphical method for integrating work exchange network

Based on the characteristics of work exchanger, a graphical integration method is developed for work exchange network. In this method, the composite curves of work sinks and work sources are plotted in the lnP versus W diagram. Two linearly approximated sink auxiliary lines are proposed to assist identifying the feasible match, one is ΔPmin greater than the sink composite curve; the other is ΔPmin less than the sink composite curve. Five matching rules are proposed for identifying the feasible match between the work sink and work source. Based on this, the maximum energy recovery, the minimum work utility and corresponding matching network can be identified. Two cases are analyzed by the proposed method, and the results show that with this method, significant energy can be saved.

Finite Element Analysis of Shaft of Centrifugal Pump

Centrifugal pump is world one of the oldest water pumping devises. The current work deals study Shaft of centrifugal pump for static and dynamic analysis. As we know rotodynamic machineries are designed keenly as there is lot of fluctuation in the loads and speeds. The shaft is analyzed by using finite element analysis technique for stresses and deflections. The total work is carried out in two stages first stage is static analysis. In this stage pump shaft is analyzed for stresses and deflection and same results are verified using graphical integration method. And second for dynamic analysis, in this stage result obtained by static analysis are used to calculate dynamic forces coming in pump shaft. Again shaft is analyzed in dynamic input condition and results are verified by using graphical integration method. The software used for the finite element meshing is HYPERMESH and solver used is RADIOSS. Result values obtained for deflection and stresses are compared in both cases. Result obtained by graphical method and FEA are nearly similar and are in acceptable limits.

Implementation of a minimal set of biological tests to assess the ecotoxic effects of effluents from land-based marine fish farms

Environmental monitoring plans (EMP) that include chemical analysis of water, a battery of bioassays and the study of local hydrodynamic conditions are required for land-based marine aquaculture. In this study, the following standardized toxicity tests were performed to assess the toxicity of effluents from eight land-base marine fish farms (LBMFFs) located on the northwest coast of Spain: bacterial bioluminescence (with Vibrio fischeri at 15 and 30min), microalgal growth (with Phaeodactyllum tricornutum and Isochrysis galbana) and sea urchin larval development (with Paracentrotus lividus and Arbacia lixula). These bioassays were evaluated for inclusion in routine fish farm monitoring. Effective concentrations (EC5, EC10, EC20, EC50) for each bioassay were calculated from dose–response curves, obtained by fitting the bioassay results to the best parametric model. Moreover, a graphical method of integrating the results from the battery of bioassays and classifying the toxicity was proposed, and the potential ecotoxic effects probe (PEEP) index was calculated. The bacterial bioluminiscence test at 30min, growth of I. galbana and larval development of A. lixula were found to be the most sensitive and useful tests. Graphical integration of these test results enabled definition of the ecotoxicological profiles of the different farms. The PEEP index, considering EC20, efficiently reflected the toxic loading potential of LBMFF effluents. In conclusion, a battery of bioassays with species from different low trophic levels is recommended as a rapid and cost-effective methodology for assessing LBMFF discharges. The graphical integration method and the PEEP index are proposed for consideration in EMPs for such farms.

Photoelastic analysis of polymerization contraction stresses in resin composite restorations

Objectives: The objective of this study was to determine the distribution and the magnitude of the internal stresses in a resin composite restoration resulting from polymerization shrinkage by using photoelastic analysis. Methods: Butt-joint box-shaped cavities (5.0 × 2.0 mm, 2.0 mm in depth) prepared in bovine teeth and in composite moulds were filled with the light-activated transparent composite. The restoration was cross-sectioned perpendicularly to the longitudinal side of the cavity and observed with polarized microscopes. The principal stresses of the restoration, normal and shear stresses at the cavity wall were evaluated by the graphical integration method. The integrity of the bond along the cavity wall was also examined by staining method. Results: The internal stresses of the restorations in bovine teeth were not large enough to observe, apparently because the gaps along the dentinal wall acted as a stress relief. On the other hand, there were no gaps along the cavity walls at the restorations in the composite moulds. As flow of the resin composite was severely limited, the maximum normal tensile stress at the cavity wall, which occurred near the internal line angle of the cavity, was calculated to reach as high as 23 MPa. The stress level near the internal line angle was higher than that near the cavo-surface margin. Conclusion: The distribution of the internal stresses in a composite restoration in a box-shaped cavity is considered to be unfavorable for the deep dentin bond. A good understanding of these phenomena may improve the clinical effectiveness of resin composite restoration.

Determination of the thermodynamic properties of [formula omitted] (s, sln) from a solid-electrolyte galvanic cell in the temperature range 1163 to 1318 K

The thermodynamic activities of MgO in the NaCl-type solid solutions which can exist in “x MgO + (1 − x) MnO’ have been determined in the temperature range 1163 to 1318 K from a solid-state galvanic cell incorporating MgF 2 as the solid electrolyte. The activities of MnO have been calculated by a graphical Gibbs-Duhem integration method. The activities of both the components exhibit positive deviations from ideality over the entire composition range. The excess molar enthalpies are found to be positive. Further, “x MgO + (1 − x) MnO’ does not conform to regular-solution behaviour. The origin of the excess thermodynamic properties is discussed in relation to the cationic size disparity and the crystal-field effects.

Heat transfer in a tunnel pasteuriser. Part III. Application of the Schultz-Olson theory

It was found that changes with time in the temperature of liquid heated in a glass bottle in a pasteuriser module can be represented by a straight line on semilogarithmic coordinates. Values of f (1/slope) and j (1/intercept) were calculated according to the method of Schultz-Olson. The influence on f of the volume-to-surface ratio of a bottle and of liquid concentration was determined. It was further established that the value of f does not depend on the initial temperature of the liquid or on the initial temperature difference. The value of the lag factor also does not depend on initial liquid temperature or on initial temperature difference. At the slowest heating point j is much larger than it is at other points in the bottle, and is greater than 1. The value of j does not depend on liquid concentration. Analysis of the relation of f and j to the ratio of heat transfer resistances showed that the lag factor, in principle, depends on the glass, whereas f depends on the properties of both the heated liquid and the glass. It was found that the overall heat transfer coefficient calculated from f differs from that obtained by the graphical integration method. The difference is a function of j. It is suggested that the heating of a liquid in a bottle may be treated as the heating of two media in series. The values of f and j depend on the relation between the accumulation of heat by the glass and the convective heating of liquid.

Nitrate Reductase Activity During Ontogeny of the Fruit of Cashew (Anacardium occidentale L.)

The in vivo nitrate reductase (NR) activity was assayed in the pedicel (apple), the fruit wall (shell) and the ovule (kernel) of cashew at 5-day intervals after fertilization. The pericarp showed high rates of enzyme activity during fresh weight accumulation, but activity remained low in the pedicel during its development. Estimation, using a graphical integration method, of total nitrate reduced by individual parts of the fruit showed that the pericarp contributed the maximum (67.5%) and the pedicel the least (7.8%) to the total nitrate assimilated in the fruit. The rate of NR activity varied with tissue nitrate content in any fruit part but was not related to the pattern of organic nitrogen accumulation except in the case of the ovule. However, NR activity of the true fruit (the nut) was accountable for about 3-4% of the total organic nitrogen present at maturity. Besides its major role in nitrate assimilation, there was evidence that the pericarp exports about 60% of its nitrogen to the seed.

On the calculation of stability constants. A computer version of Fronaeus' graphical integration method

On the calculation of stability constants. A computer version of Fronaeus' graphical integration method

A statistical study of daily maximum temperatures at Madras during the summer months

Daily maximum temperature data. of Madras for the months April, May and June for the period 1945.1964 have been analysed. The frequency of spells of days having the same type of maximum temperature tendencies appear to follow a random probability model sc =Kpx, K and p being the parameters determinable from the data. sx representing the frequencies of spells of x days duration. It is also shown that low level wind field over Madras and Anantapur at OOZ can be utilised in predicting the day's maximum temperature. Maximum temperature forecast diagrams for May the hottest mouth, have been constructed on the basis of graphical integration method; and utility of these diagrams discussed.

Scattering of Light by Gel Structures. I. Regenerated Cellulose

A low-angle light scattering photometer is described and applied to the study of regenerated cellulose gels. The scattering patterns were recorded over the angular range from 0.5° to ∼75° for the fresh gel in water (F film) and for the same sample solvent exchanged to an imbibition liquid of refractive index 1.543 (PF film). A sharp drop in over-all turbidity was recorded in going from F to PF film, indicating an intimate penetration of the nonswelling imbibition liquid into the cellulose fine structure. The observed scattering for these samples was interpreted in terms of the Debye-Bueche correlation function using the graphical integration method. The size of the regions of correlated variation in refractive index was 5800 Å for the F film and 6500 Å for the PF film; this corresponded to refractive index fluctuations of 0.005 and 0.001, respectively. It is calculated that these fluctuations in refractive index could arise from about a 3% variation in the degree of order over the respective correlation distances. Such structure heterogeneities would then be associated with a second level organization of the fine structure.

Pressure Dependence of the Magnetization of Cobalt

Single-crystal and polycrystalline specimens of cobalt were subjected at room temperature to hydrostatic pressures up to about 5 kbars, and the effects on their magnetizations were measured in fields up to 14 kOe. For the single crystal magnetized along its easy axis, complete saturation was achieved at about 3 kOe, and above this field the pressure dependence of the magnetization (per g) remained constant at a saturation value, σs−1 (∂σs/∂p), of −2.18×10−4 kbars−1. This value is shown to be identifiable with the pressure dependence of the atomic moment at 0°K and has the same sign and even roughly the same magnitude as the recent low-temperature pressure results for iron and nickel. For the cobalt polycrystal, the change in magnetization with pressure varied widely (though smoothly) with field before attaining the above saturation value at about 13 kOe. The lack of saturation at lower fields was attributed entirely to magneto-crystalline anisotropy, and a graphical integration method applied to the data gave the result: K−1(∂K/∂p) = −23.2×10−4 kbars−1, where K is the total anisotropy energy (per g) and is linearly related to the anisotropy coefficients, K1 and K2. The similarity in sign and the order of magnitude difference between the K−1(∂K/∂p) and σs−1 (∂σs/∂p) values for cobalt are closely analogous to the situation previously found in iron and an iron-silicon alloy.