Hysteretic Implications for Graded Bed Load Sediment Transport in Symmetrical Hydrograph Flows

Differential parametric values associated with bed load sediment transport, that result at the same discharge levels on the rising and falling limbs of a flood hydrograph, are usually defined as bed load hysteresis. This hysteresis in bed load sediment transport rates is of considerable interest in the field of fluvial hydraulics. Within this study, a series of well-defined, symmetrical hydrograph flows are generated over a graded, mobile sediment bed to fully examine the hysteresis of the resulting bed load sediment transport in terms of the threshold of motion, and differential bed load transport rates and bed load yields during the hydrographs. The experiments are conducted in a titling flume without sediment supply specified at the upstream inlet, thereby representing typical river reach conditions immediately downstream of a dam that are exclusively subject to net in-channel bed degradation from sediment transport initiated during flood events. Our results show that the fractional bed load transport of defined fine, medium and coarse size classes within the graded sediment bed generally display clockwise, no/mixed and counter-clockwise hysteresis patterns, respectively, with clockwise hysteresis most commonly found for the coarse size class mobilised by hydrographs with long durations. By contrast, counter-clockwise hysteresis is usually observed for fine size class transported by hydrographs with short durations. Accordingly, the corresponding reference stresses for each size class vary between different hydrographs and are primarily controlled by the hydrograph flashiness (i.e. unsteadiness) and magnitude (i.e. total water work). Moreover, it is shown that the hysteresis effect, particularly for those size classes and hydrograph combinations that result in clockwise and counter-clockwise behaviour, should be fully accounted for when reproducing bed load transport rates using separate-limb based method. Finally, we investigate the relative fractions of the overall bed load yields generated during the rising and falling limbs of all symmetrical hydrographs (i.e. the bed load yield ratio), which are found to be primarily dependent on bed load transport hysteresis. Finally, the relationship between the bed load yield ratio and the ratio of reference stresses for the fractional sediment motion of each size class on both limbs is found to follow a power law.

Parameter selection of Polystyrene-Dietilenetriaminepenta acetate Resin Synthesis for the separation of rare Earth Elements by using Plackett-Burman Experimental Design

The development of the separation method has an essential role in developing science and technology for the separation and purification of an element or compound from other mixtures based on differences in physical and chemical properties. This research is more focused on the selection parameters of polystyrene-based resin production using diethylene triamine penta-acetate (DTPA) light, which used as a prototype for improved scale production. The Plackett-Burman design was used to select variables that have significant influence in Methylaminopolystyrene-Diethylenetriaminepentaacetate (MAP-DTPA) resin synthesis. Eleven variables such as mol ratio of Methylamino Polystyrene and diethylene triamine penta-acetate ligands, solvent volume, reaction time, stirring rate, reaction temperature, total volume, reaction pH, incubation time, ammonia concentration, and the addition of methanol were carried out for the selection of parameters or variables in the process of MAP-DTPA resin synthesis through a statistical approach in studies for design experiments using Software Design Expert 9.0.6.2. Of the eleven variables in resin synthesis obtained, six variables have a positive influence on the yield ratio value (percent yield ratio) of MAP-DTPA resin are the mol ratio of MAP and DTPA, Stirring Rate, reaction temperature, total volume, degree of acidity, and ammonia concentration.

Quantifying the Effect of Initial Fluctuations on Isospin-Sensitive Observables from Heavy-Ion Collisions at Intermediate Energies

Initial fluctuation is one of the ingredients that washes fingerprints of the nuclear symmetry energy on observables in heavy-ion collisions. By artificially using the same initial nuclei in all collision events, the effect of the initial fluctuation on isospin-sensitive observables, e.g., the yield ratio of free neutrons with respect to protons Nn/Np, 3H/3He yield ratio, the yield ratio between charged pions π−/π+, and the elliptic flow ratio or difference between free neutrons and protons v2n/v2p (v2n-v2p), are studied within the ultrarelativistic quantum molecular dynamics (UrQMD) model. In practice, Au + Au collisions with impact parameter b = 5 fm and beam energy Elab = 400 MeV/nucleon are calculated. It is found that the effect of the initialization on the yields of free protons and neutrons is small, while for the yield of pions, the directed and elliptic flows are found to be apparently influenced by the choice of initialization because of the strong memory effects. Regarding the isospin-sensitive observables, the effect of the initialization on Nn/Np and 3H/3He is negligible, while π−/π+ and v2n/v2p (v2n-v2p) display a distinct difference among different initializations. The fingerprints of symmetry energy on π−/π+ and v2n/v2p can be either enhanced or reduced when different initializations are utilized.

Study on the Choice of Wastewater Treatment Process Based on the Emergy Theory

With the increase in industrialization and urbanization, water pollution has become increasingly serious, and wastewater treatment has become a common step in preventing this. For a greater understanding of the sustainability of different wastewater treatment systems, two processes, Anaerobic Baffled Reactor + Anaerobic-Anoxic-Oxic and Anaerobic Baffled Reactor + Cyclic Activated Sludge System, were selected, and their sustainability was evaluated based on three indicators, namely emergy yield ratio, environmental load rate, and emergy sustainability development index, according to emergy theory. The results show that the emergy yield ratio and environmental load rate of the ABR + CASS process were lower than those of the ABR + A2/O process, and the emergy sustainability development index of the ABR + CASS process was higher than that of the ABR + A2/O process, showing better sustainability. The research methods and findings of this study play an important role for decision makers in selecting sustainable wastewater treatment processes.

FORWARD BACKWARD ELECTRON YIELD RATIO FOR α-PARTICLE INDUCED EMISSION FROM DIFFERENT MATERIALS

In this work, the ratio of forward and backward electron yields for emission induced by the isotropic flux of α-particles from zinc was measured. On the basis of the measured values and experimental data obtained in earlier experiments for other materials, a systematization of the electron yield ratio for forward and backward emission was done, and a relationship of the ratio with stopping power of an ion in a substance was found. The dependence of work function for various materials on the ratio of the electron emission yields was analyzed.

Analisis Kebijakan Hutang dan Deviden terhadap Nilai Perusahaan Terdaftar di Bursa Efek Indonesia

Penelitian ini bertujuan untuk mengetahui antara lain: 1) menganalisis pengaruh kebijakan hutang debt to equity ratio berpengaruh terhadap nilai perusahaan, 2) menganalisis pengaruh kebijakan hutang debt to asset ratio berpengaruh terhada nilai persahaan, 3) menganalisis pengaruh kebijakan deviden devidend yield ratio terhadap nilai perusahaan, 4) menganalisis pengaruh kebijakan devidend payout ratio terhadap nilai perusahaan. Metode pengambilan sampel yang digunakan adalah motode purposive sampling diperoleh sebanyak 13 sampel. Jenis data yang digunakan dalam penelitian ini merupakan data skunder berupa laporan tahunan dan laporan keuangan perusahaan. Analisis regresi berganda digunakan dalam penelitian ini untuk melihat pengaruh variabel secara individu. Hasil menunjukan bahwa selama periode 2016-2018, 1) debt to equity ratio secara parsial berpengaruh negatif signifikan terhadap price book value, 2) debt to asset ratio secara parsial tidak berpengaruh signifikan terhadap price book value, 3) devidend yield ratio secara parsial berpengaruh positif terhadap price book value, 4) devidend payout ratio secara parsial berpengaruh positif signifikan terhadap price book value.

FORWAND BACKWARD ELECTRON YIELD RATIO FOR α-PARTICLE INDUCED EMISSION FROM DIFFERENT MATERIALS

In this work, the ratio of forward and backward electron yields for emission induced by the isotropic flux of α-particles from zinc was measured. On the basis of the measured values and experimental data obtained in earlier experiments for other materials, a systematization of the electron yield ratio for forward and backward emission was done, and a relationship of the ratio with stopping power of an ion in a substance was found. The dependence of work function for various materials on the ratio of the electron emission yields was analyzed.