Inhomogeneity detection in the rainfall series for the Mae Klong River Basin, Thailand

An accurate and complete rainfall record is prerequisite for climate studies. The purpose of this research study was to evaluate the homogeneity of the rainfall series for the Mae Klong River Basin in Thailand. Monthly rainfall data of eight stations in the Mae Klong River Basin for the period 1971–2015 were used. The double mass curve analysis was used to check the consistency of rainfall data, whereas the absolute homogeneity was assessed using the Pettitt test, standard normal homogeneity test, Buishand test, and von Neumann test at a 5% significance level. The results of these tests were qualitatively classified as ‘useful’, ‘doubtful’, and ‘suspect’ according to the null hypothesis. Results of the monthly time series indicated the rainfall data as ‘useful’ for 75% of the stations, while two stations’ data were classified as ‘doubtful’ (Stn130221) and ‘suspect’ (Stn376401). On an annual scale, seven out of eight stations data were classified as ‘useful,’ while one station (Stn376401) data were classified as ‘suspect’. Double mass curve analysis technique was used for the adjustment of inhomogeneous data. The results of this study can help provide reliable rainfall data for climate studies in the basin.

Evaluation of external contamination on the vial surfaces of some hazardous drugs that commonly used in Chinese hospitals and comparison between environmental contamination generated during robotic compounding by IV: Dispensing robot vs. manual compounding in biological safety cabinet

Objectives The aims of the study were to evaluate the external contamination of hazardous drug vials used in Chinese hospitals and to compare environmental contamination generated by a robotic intelligent dispensing system (WEINAS) and a manual compounding procedure using a biological safety cabinet (BSC). Methods Cyclophosphamide, fluorouracil, and gemcitabine were selected as the representative hazardous drugs to monitor surface contamination of vials. In the comparative analysis of environmental contamination from manual and robotic compounding, wipe samples were taken from infusion bags, gloves, and the different locations of the BSC and the WEINAS robotic system. In this study, high-performance liquid chromatography coupled with double mass spectrometer (HPLC-MS/MS) was employed for sample analysis. Results (1) External contamination was measured on vials of all three hazardous drugs. The contamination detected on fluorouracil vials was the highest with an average amount up to 904.33 ng/vial, followed by cyclophosphamide (43.51 ng/vial), and gemcitabine (unprotected vials of 5.92 ng/vial, protected vials of 0.66 ng/vial); (2) overall, the environmental contamination induced by WEINAS robotic compounding was significantly reduced compared to that by manual compounding inside the BSC. Particularly, compared with manual compounding, the surface contamination on the infusion bags during robotic compounding was nearly nine times lower for cyclophosphamide (10.62 ng/cm2 vs 90.43 ng/cm2), two times lower for fluorouracil (3.47 vs 7.52 ng/cm2), and more than 23 times lower for gemcitabine (2.61 ng/cm2 vs 62.28 ng/cm2). Conclusions The external contamination occurred extensively on some hazardous drug vials that commonly used in Chinese hospitals. Comparison analysis for both compounding procedures revealed that robotic compounding can remarkably reduce environmental contamination.

Using four different approaches to separate the effects of climate change and human activities on sediment discharge in karst watersheds

<p>Quantifying the relative contributions of climate and human activities to changes in sediment discharge is closely related to regional water resources, soil management and even the healthy operation of ecosystems. However, few studies used different methods to decompose influences of climatic variability and human activities on sediment discharge change, especially in karst regions of southwest China where experiencing severe soil erosion. This study systematically reviewed four different methods including simple linear regression method, double mass curve method, sediment identify factor analysis, and elastic coefficient method to separate the contribution of climate change and human activities to sediment discharge variation in four karst watersheds of southwest during 1955 to 2015. The trend and abrupt change year of sediment discharge in four watersheds were obtained by nonparametric Mann-Kendall test. Result showed that the sediment discharge in four watersheds all decreased significantly (<em>P</em><0.05), and the abrupt change years were 2003, 2003, 2004 and 2004 for Wujiang, Yujiang, Hongshui, and Xijiang watersheds, respectively. The simple linear regression method, double mass curve method and elastic coefficient method all indicated that the sediment discharge was mainly influenced by human activities, with the contribution rate ranging from 73% to 101%. For the sediment identify factor analysis method, the sediment concentration is the principal factor influencing sediment discharge variation, and the contribution rate of sediment discharge varied from 100% to 154%. The results can provide good reference value for evaluating the influence of the climate and human activities on sediment discharge, and is significance for proper formulation of regional soil conservation policy in karst watersheds.</p>

Condition optimization for organizing the operation of connected trains on an ongoing basis on the Trans-Siberian Railway of the Eastern operational range of the railway network

A target function has been developed for solving the problem of increasing the carrying capacity of loaded lines by organizing the motion of connected (double) trains on an ongoing basis, providing for the minimization of investment and operating costs. Conditions of constant circulation of connected trains on the Skovorodino—Smolyaninovo line section of the Trans-Siberian Railway, where the prospective freight flows exceed the available carrying capacity, are considered. All solutions are designed especially for this section. It is taken into account that the main investments for the implementation of the new method are related to the development of stations for working with connected trains, as well as to strengthening the power supply system for driving connected trains of double mass. Additional operating costs are determined by the need to perform various technological operations with connected trains. Estimated number of connected trains Nрасч has been established to ensure the required long-term carrying capacity. In order to save costs, the value of N расч is minimized on the basis of comparing the values of the maximum possible number of connected as well as single trains with the required carrying capacity on different sections of the line. The article considers methodology for the placement of stations for connecting/disconnecting trains, maximally combined with stations for changing locomotive crews, which provides savings in investment and operating costs. The optimal one was chosen from three possible options of such stations placement. Two schematic diagrams of stations for connecting/disconnecting trains are considered — with sequential and parallel execution of operations. It is shown that the minimization of costs is ensured by the sequential (flow) execution of these operations. In order to save investments, the development of a technical design for the implementation of a new method should provide the possibility of using auxiliary stations for connecting/disconnecting trains and changing locomotive crews of auxiliary stations with more favorable topographic conditions and the location of the station buildings for its development. Specific proposals on this issue are given for the considered line section of the Trans-Siberian Railway. Taking into account the current provisions, a method has been developed for calculating the operating fleet of locomotives handling connected trains, the size of which is minimized. Organization of the driving of connected trains on an ongoing basis ensures the effective development of the prospective freight traffic.

Riparian zone hydrological rehabilitation along the Gyöngyös stream (Hungary)

<p>Climate change induced drought periods are likely to cause decline in groundwater level,<br>which can degrade riparian ecosystems (such as riparian forest). With a reasonable water<br>supply, water scarcity can be stopped and these valuable ecosystems can be preserved.</p><p>The aim of the research was to evaluate the impact of water supply interventions regarding<br>habitat reconstruction of Doroszló meadows near Kőszeg (west Hungary). Groundwater<br>monitoring wells have been installed at 4 representative sites of the area. Groundwater wells<br>were 3–5 m deep and screened at their bottoms (2–4 m). The water level of the wells was<br>recorded manually, on a weekly basis, with an accuracy of 1 mm. In the neighborhood of the<br>wells surface close soil moisture values were also measured. Data from April 2019 to<br>October 2020 were collected. Local meteorological data measured in Kőszeg were also<br>used for analysis.</p><p>Evaluating the data from each well in the pre-intervention period (the analysis of the<br>relationship of the wells with the control well), we came to the conclusion that the Well-1 and<br>Well-2 behave similarly. The impacts of the water supply on the groundwater level were<br>analysed using a “double mass curve” and a “treatment-control space-time deviations”<br>approach. Result showed that the intervention had a positive effect only on the Well-3 from<br>the examined wells. The data evaluation denoted that unfortunately the control well was also<br>affected by water supply interventions.</p><p>This research has been supported by the Ministry of Agriculture in Hungary.</p>