Impact of hydropower dam on total suspended sediment and total organic nitrogen fluxes of the Red River (Vietnam)

The Red River is a typical example of the Southeast Asian rivers, which has been strongly affected by human activities. This paper analyses the change of total suspended sediment (TSS) load of the Red River from 1960 to 2015 in which numerous new dams in both China and Vietnam have been constructed. A strong decrease of TSS load of the whole Red River (from 79±26×106 t yr−1 in 1960s to 6±1×106 t yr−1 in 2010s) allocated to the dam impoundments in spite of population and deforestation increase. Base on the experimental equation describing the relationship between TSS and total organic nitrogen (TON) concentrations, and on the available data of TSS concentration and river discharge, the longterm TON concentrations and fluxes were calculated for the three tributaries and the whole Red River. The annual average of TON concentrations spatially varied from 0.41 to 3.19 mg L−1, averaging 0.98 mg L−1 for the whole period; the lowest was found for the Da River where the new dams have been impounded. The highest TON concentrations and fluxes occurred in the wet season in relationship with the highest sediment loads and river discharges. The riverine TON fluxes transferred to estuary significantly decreased from 141×103±38×103 t yr−1 (equivalent to 902±247 kg km−2 yr−1) in 1960s to 32×103±5×103 t yr−1 (equivalent to 207±35 kg km−2 yr−1) in 2010s. The TSS flux decrease has driven a clear reduction of associated elements like nitrogen, which let to hypothesis a change in biogeochemical processes in the coastal zone.

RESEARCH ON BUILDING FOR DEPENDENCE OF INSULATION PARAMETERS OF THE 6kV GRID WITH THE ENVIROMENT AND STRUCTURAL PARAMETERS OF OPEN-PIT MINES IN THE QUANG NINH AREA

Medium voltage insulation indicators depend on many factors such as environment, length of feeders, numbers of transformers and motors connected on the grid...The values determined by experimental measurements will be used to build up maths distributions. Base on these results, an experimental equation will be formed for determining capacitance and impedance of 6kV grid to ground in QuangNinh open pit coalmines.

Statistical Moment Theory and Non-Compartmental Analysis

Mathematical model a numerical classification of the biological framework and utilized to state quantitative connections. A pharmacokinetic compartment is a numerical idea that portrays a space in the body that medication seems to possess These models just mediate the test information and permit an experimental equation for the assessment of medication focus with time. A non- compartmental model is a pharmacokinetic model that does not involve the consequence of a definite compartment model is called a Non-compartment model. This approach is based on the consequence that the drugs or substances created in a metabolic process follow direct kinetics, which is the basis that this approach can be functional to any compartment model. The non- compartmental analysis gives an elective strategy to portraying drug pharmacokinetics without appointing a specific compartmental model to the medication.

An Improved Experimental Equation for Precise Wave Spring Design Using Finite Element Method and Tests

This paper presents an improved experimental equation for representing wave spring behaviors. Wave springs were widely used for automobile automatic transmission and have to be precisely controlled. In fact an experimental equation was provided by mechanical design handbook. However the accuracy of the equation is not suitable. Therefore we tried to optimally modify correction factor K used in the equation without modifying the whole equation. For this different models of springs were manufactured to test and simulate. Theses results were analyzed and redefined correction factor K. To evaluate the proposed approach modified correction factor K was applied into various models and good agreement was obtained.

Theory and Verify of Mensurate Cl- Ion by Flow Injection-Cathodic Potentiometric Stripping Analysis

In this paper, the theoretical equation of flow injection-cathodic potentiometric stripping analysis for Cl-ion determination was derived from theoretical analysis, and the experimental equation was summarized using multiple linear regression method. The result shows that the theoretical equation of flow injection-cathodic potentiometric stripping analysis for Cl-ion is: (dt/dE)max=K Apr-1/2D2/3-1/6Vf1/2teCx-/is;that the experimental equation of multiple linear regression method is: (dt/dE)max Cl-1.86×1010Vf0.568teCCl-/is. The two results are similar on Vf-average flow rate, te-concentrate time, CCl--Cl-ion concentration and isconstant current.

Optimize the Dielectric Slab of the Tunable Active Frequency Selective Surface Absorbing Material

Active frequency selective surface (AFSS) absorber loaded with PIN diodes is a new type of structural absorber with tunable absorption properties. This absorber is similar to a sandwich, the surface is an AFSS, the middle is a dielectric slab, and the bottom is a metallic ground. In order to design and fabricate a thin and good performance absorber, the selection of dielectric slab is very important. In this paper, we detailed investigated the effects of the dielectric slab parameters (permittivity and thickness) to the absorption properties by experiments, and an experimental equation was proposed to provide a better description about their relationship. The measured results indicated there was an optimum thickness for the dielectric slab to produce the broadest bandwidth. The experimental equation was useful to optimize the design of the absorber.