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Statistical Parameters Applied to the Analysis of Partial Discharge Signals in Power Cables

100%

Guo C. , Huang C. , Yao L. , Jiang X.

tom R. 86, nr 3

282-285

To analyze the partial discharge signals in power cables, statistics method is investigated according to the experiment data of defect models. Phase resolved partial discharge graphics and associated pulse distributions are acquired to show the characteristics of defect PD events. 28 statistical parameters are extracted and employed to find the different representation of the defect models in power cables. The results show that statistics method and are useful and effective in the partial discharge signals analysis.

Do analzy sygnału częściowego wyładowania w kablach użyto metod statystycznych. Rozkład statystyczny impulsu wyładowania pozwala na określenie defektu. 28 parametrów statystycznych zostało wydobytych i wykorzystanych do określania rodzaju defektu w kablu. Wyniki wskazują że metody statystyczne są dobrym narzędziem analizy sygnału częściowego wyładowania.

Temporal and spatial variations in soil TOC, TN, and TP, and their relationships in bioretention tanks

88%

Guo C. , Li J. , Li H. , Liu Z. , Li P.

nr 6

This study aims to explore the temporal and spatial variations of soil total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), and the relationships between C/N, C/P and TOC, TN, and TP in bioretention tanks. Two bioretention tanks (tank No. 1: depth of 0~20 cm was vacant aquifer layer, 20~90cm, filled with planting soil, 90~105 cm, filled with gravel; tank No. 3: 0~20 cm was aquifer layer, 20~50 cm, filled with planting soil, 50~90 cm, filled with blast furnace slag and sand; 90~105cm, filled with gravel) were used in simulation stormwater runoff purification experiments to collect planting soil samples at intervals of one hour before inflow and 24 hours after the end of inflow. The results revealed that soil TN, TP, and TOC in 2 bioretention tanks were mainly concentrated at 10~30 cm in soil. The contents of TN and TP varied from 0.32 g kg⁻¹ to 0.50 g kg⁻¹ and from 0.83 g kg⁻¹ to 1.35 g kg⁻¹ within the investigated zone, respectively. Soil TN content in the 2 bioretention tanks before the inflow was slightly greater than after the inflow, but the opposite was true for TP, as it was less before the inflow than after. The potential of TN and TP fixation in No. 1 was higher than that in No, 3 within the upper 30 cm depth, which were related to the infiltration rate of underlying fillers (the underlying fillers of No. 1 is planting soil, and which is the blast furnace slag and sand in No. 3). The TOC content in the 2 bioretention tanks varied from 4.24 g kg⁻¹ to 8.97 g kg⁻¹, and the average contents decreased with the increasing depths. The C/N and C/P were positively correlated with TOC, while they were negatively correlated with TN and TP contents, which showed that soil C/N and C/P were mainly controlled by TOC in soil. The conclusions can provide references for the design and operation evaluation of bioretention facilities.

Beta-hydroxybutyrate, glucose, calcium, phosphorus, and vitamin C concentrations in blood of dairy cows with subclinical ketosis during the early lactation

75%

Zhang Z. , Liu G. , Li X. , Wang Z. , Kong T. , Zhang N. , Guo C.

nr 1

71-74

The objective of this study was to examine the association between β-hydroxybutyrate (BHBA) and glucose, calcium (Ca), phosphorus (P), and vitamin C concentrations in dairy healthy and with subclinical ketosis cows during an early lactation period. The blood from 99 healthy cows and 26 sub-clinically ketotic cows within the first two months of lactation was sampled. Serum concentration of BHBA was measured by enzymatic-rate method, glucose by oxidase method, and P by colorimetric method. These tests were performed in a biochemical auto-analyser. Serum Ca concentration was measured by atomic absorption spectrometer followed by acid digestion. Vitamin C was measured by HPLC. The results showed that in ketotic cows serum BHBA was significantly increased (P<0.01) and glucose and Ca concentrations were significantly decreased (P<0.01) as compared to healthy cows, while vitamin C and P concentrations were similar in the both groups of cows (P>0.05). The serum BHBA concentration was negatively correlated with the serum glucose and Ca concentrations (P<0.01). Vitamin C and P status of cows with subclinical ketosis was not affected by BHBA. Serum Ca concentration can be used as a reference index for the diagnosis of subclinical ketosis.