Identifying Correlation of Coal Seams in the Tien Hai Area, Northern Vietnam by Using Multivariate Statistic Methods

In northern Vietnam, the Tien Hai area is considered a high potential area of coal deposits. Twohundred fifty-six geochemical coal samples of 13 cores in the Tien Hai area investigate coal seams andcoal deposits to identify the correlation of coal seams. According to the statistical method and clusteranalysis of geochemical samples, the results indicate that the Mg, V, As, Ca, Zn, Cr, Co, K, Na, Sr, Fe,Ge, Re, U, Mo, Th, and Ga elements are good indicator elements of the major and trace elements in coal.Most of them comply with the normal or lognormal distribution rules. Besides, the Yb, Sc, Ho, Er, Tm,Lu, Y, Tb, Pr, Dy, and Sm elements are also good indicator elements for rare earth elements in the region.Therefore, the selected elements are used to identify the correlation of the coal seams in the Tien Hai area.Based on the similarity degree between studied objects, the results of grouping boreholes in coal seamsshow that the correlation of coal seam TV2-11 is suitable and acceptable, the coal seams TV3-6a, TV3-6b, and TV3-6c can be grouped into the coal seam TV3-6. These results present that the models can helpstudy geochemical coal samples and identify the correlation of the coal seams in the Tien Hai area.Additionally, the statistical analysis shows a remarkable degree to determine the correlation of the coalseams. Geochemical coal data can help to evaluate the indicator elements of the major, trace elements,and rare earth elements in coal seams and coal rashing of adjoining and pillar rocks in the Tien Hai area,northern Vietnam.

Influencing Factors of Student Satisfaction With the Teaching Quality of Fundamentals of Entrepreneurship Course Under the Background of Innovation and Entrepreneurship

Innovation and entrepreneurship education is a key way to cultivate applied talents in colleges and universities. This article aimed to optimize the teaching quality of the Fundamentals of Entrepreneurship courses by constructing a conceptual model of “teaching quality–student satisfaction.”Teaching quality is divided into four indicator elements, teaching content, teaching methods, teaching conditions, and teaching management. A student satisfaction questionnaire was designed to measure the teaching quality of a Fundamentals of Entrepreneurship course. The reliability and validity of survey data from Linyi University were analyzed using SPSS.20 software. Through correlation and multiple regression analysis, it can be seen that the teaching content, teaching methods, teaching conditions and teaching management have a significant positive correlation with the teaching quality of the Fundamentals of Entrepreneurship course, which is an important factor affecting student’s satisfaction, and there is a certain gap between the expectation of teaching quality and student’s satisfaction. On this basis, suggestions are put forward to improve student satisfaction with the teaching quality of Fundamentals of Entrepreneurship courses, and to provide empirical evidence and recommendations for continuously improving the teaching quality of Fundamentals of Entrepreneurship courses, thereby improving college students’ employment and entrepreneurship ability.

The i̇nfluence of water on the change i̇n engi̇ne oi̇l quali̇ty i̇ndi̇cators

Introduction. One of the main types of deposits in an internal combustion engine is an emulsion or sludge formed by water, decomposition of fuel residues and solid residues. The sludge usually settles on the colder surfaces of the engine, such as the bottom of the crankcase pan, valve chambers and upper boards. The main problem is that this type of deposits can be collected by the engine oil and transferred to areas such as the oil pump, intake valve or oil channels, where the sludge can interfere with the flow of oil and cause a failure of the lubrication mode. In addition to the disruption in the operation of the above-mentioned systems, the engine oil quality indicators are also undergoing changes for the worse.Materials and methods. To monitor the condition of the engine oil, it is necessary to determine the characteristics of its performance, such as: kinematic viscosity at 40 oC and at 100 oC, acid number, base number and determine the number of elements – indicators of additives and wear products contained in the engine oil. The viscosity was determined using a Stabinger SVM 3000 viscometer. It measures the dynamic viscosity and density of oils and fuels in accordance with ASTM D7042 and automatically calculates the kinematic viscosity, viscosity index and outputs the measurement results. The acid and base numbers were determined using an automatic titrator TitroLine alpha plus, and the presence of indicator elements in engine oil using an inductively coupled plasma optical emission spectrometer of the iCAP 7000 series, designed for analysis and determination of the number of indicator elements in liquid and solid samples.Results. The dynamics of changes in the performance characteristics of the Gazpromneft Diesel Ultra 10W-40 engine oil with an extended replacement interval, which is applicable for equipment operating in severe conditions, depending on the water content in the samples of this lubricant, was analyzed.Conclusion. The consequences that may occur due to water entering the engine oil are indicated.

Stream Sediments of the Pestrinsk Silver-Bearing System (Northeastern Russia)

The composition, structure, and formation features of the exogenous anomalous geochemical fields (AGCFs) identified through stream sediments (SSs) are considered here within the Pestrinsk silver-bearing system and the Goltsovy silver-polymetallic deposit. The research was performed in the southern part of the Balygychan-Sugoy trough (northeastern Russia). The exogenous AGCFs of the main indicator elements of ores, formed in cryolithogenesis zone conditions, were studied. We used the results of multi-scale areal geochemical surveys of SSs. A survey of SSs at 1:200,000 scale was found to be effective at the stage of regional forecasting. Indeed, it is characterized by simplicity and the possibility of obtaining information operatively regarding the metallogeny of the area. It was found that at the local forecast stage, when prospecting for mineralization, the most effective was a survey of SSs at 1:50,000 scale. The AGCFs identified during this survey were distinguished by a richer component composition, higher contrast, and closer relationship with ores. During the lithochemical sampling of the watercourse heads, where alluvial sediments were found to be almost completely absent, a positive result was obtained by the bryolithochemical method, which is based on moss sampling together with a fine fraction of alluvium held by a moss cushion. The method enabled the sampling of watercourse heads and thus yielded information about the presence or absence of anomalous concentration fields of ore elements.

The Brent Crater: An Alkaline Igneous Complex

The Brent Crater was discovered in 1951 from aerial imagery. The Crater was thoroughly investigated in the 1950s to early 1970s. The consensus throughout this period of exploration was that the crater was the result of a chondrite impact. This theory was disputed in 1971 in a paper by K.L. Currie who proposed that the crater was the result of alkaline volcanic activity within the Nipissing Alkaline Petrographic Province which resulted in geochemically and morphologically similar formations in the area of Lake Nipissing. Little research has been conducted to further verify or dispute this theory since. A 1977 national Uranium reconnaissance program followed up by a 1983 and 1984 field exploration and airborne geophysics program located a verified alkaline volcanic structure 15 km east of the crater known as the Allan Lake Carbonatite. The geophysical and geochemical data acquired from this work was processed to create aweighted probability raster of indicator elements of alkaline igneous materials. The Allan Lake anomaly demonstrates a more significant anomaly than the anomaly present at the Brent Crater. This anomaly is proposed to be the result of higher erosional rates in the crater. This hypothesis was tested by analyzing lake sediment concentrations of indicator elements in the nearby lakes. Given the world-renowned status of the Brent Crater as an example of a chondrite impact crater, it is important to either confirm Currie’s theory as a fact or disprove the theory to allow the structure to continue to act as an analogue without uncertainty.

Indicator Elements Combination’s Characteristic and Genesis of Four Types of Uranium Mineralization in China

China uranium mineralization in accordance with different metallogenic host rocks are mainly divided into four types: granite type uranium mineralization, volcano rock type uranium mineralization, the carbonate-siliceous-politic rock type and sandstone type uranium mineralizations, four types of uranium mineralization is due to different genesis and metallogenic environment, the indicator elements also have bigger difference. In this paper, through the national uranium resources potential evaluation project research results, describes characteristics of indicator elements of four types uranium mineralization, and from the perspective of element geochemistry, analyzes causes of the indicator elements combination.