Rapid determination of wastewater COD using Mn（H2PO4）2 as catalyst

A new rapid determination method of wastewater COD in mixed acid solution H_2SO_4-H_3PO_4,with Mn(H_2PO_4)_2 as catalyst,has been proposed in this paper. Through orthogonal experiment, the optimal test conditions have been determined: Mn(H_2PO_4)_2:0. 3g,H_2SO_4:H_3PO_4=6:1(V/V),reflux time:5 minutes. The results were similar to that of the standard method, but the test time was only 1/24 of that and the test cost decreased 85%.

Regularized determination of interfacial heat transfer coefficient during ZL102 solidification process

The interfacial heat transfer coefficient(IHTC)between the casting and the mould is essential to the numerical simulation as one of boundary conditions.A new inverse method was presented according to the Tikhonov regularization theory.A regularized functional was established and the regularization parameter was deduced.The functional was solved to determine the interfacial heat transfer coefficient by using the sensitivity coefficient and Newton-Raphson iteration method.The temperature measurement experiment was done to ZL102 sand mold casting,and the appropriate mathematical model of the IHTC was established.Moreover, the regularization method was used to determinate the IHTC.The results indicate that the regularization method is very efficient in overcoming the ill-posedness of the inverse heat conduction problem(IHCP),and ensuring the accuracy and stability of the solutions.

LoRa Sense:Sensing and Optimization of LoRa Link Behavior Using Path-Loss Models in Open-Cast Mines

The Internet of Things(IoT)has orchestrated various domains in numerous applications,contributing significantly to the growth of the smart world,even in regions with low literacy rates,boosting socio-economic development.This study provides valuable insights into optimizing wireless communication,paving the way for a more connected and productive future in the mining industry.The IoT revolution is advancing across industries,but harsh geometric environments,including open-pit mines,pose unique challenges for reliable communication.The advent of IoT in the mining industry has significantly improved communication for critical operations through the use of Radio Frequency(RF)protocols such as Bluetooth,Wi-Fi,GSM/GPRS,Narrow Band(NB)-IoT,SigFox,ZigBee,and Long Range Wireless Area Network(LoRaWAN).This study addresses the optimization of network implementations by comparing two leading free-spreading IoT-based RF protocols such as ZigBee and LoRaWAN.Intensive field tests are conducted in various opencast mines to investigate coverage potential and signal attenuation.ZigBee is tested in the Tadicherla open-cast coal mine in India.Similarly,LoRaWAN field tests are conducted at one of the associated cement companies(ACC)in the limestone mine in Bargarh,India,covering both Indoor-toOutdoor(I2O)and Outdoor-to-Outdoor(O2O)environments.A robust framework of path-loss models,referred to as Free space,Egli,Okumura-Hata,Cost231-Hata and Ericsson models,combined with key performance metrics,is employed to evaluate the patterns of signal attenuation.Extensive field testing and careful data analysis revealed that the Egli model is the most consistent path-loss model for the ZigBee protocol in an I2O environment,with a coefficient of determination(R^(2))of 0.907,balanced error metrics such as Normalized Root Mean Square Error(NRMSE)of 0.030,Mean Square Error(MSE)of 4.950,Mean Absolute Percentage Error(MAPE)of 0.249 and Scatter Index(SI)of 2.723.In the O2O scenario,the Ericsson model showed superior performance,with the highest R^(2)value of 0.959,supported by strong correlation metrics:NRMSE of 0.026,MSE of 8.685,MAPE of 0.685,Mean Absolute Deviation(MAD)of 20.839 and SI of 2.194.For the LoRaWAN protocol,the Cost-231 model achieved the highest R^(2)value of 0.921 in the I2O scenario,complemented by the lowest metrics:NRMSE of 0.018,MSE of 1.324,MAPE of 0.217,MAD of 9.218 and SI of 1.238.In the O2O environment,the Okumura-Hata model achieved the highest R^(2)value of 0.978,indicating a strong fit with metrics NRMSE of 0.047,MSE of 27.807,MAPE of 27.494,MAD of 37.287 and SI of 3.927.This advancement in reliable communication networks promises to transform the opencast landscape into networked signal attenuation.These results support decision-making for mining needs and ensure reliable communications even in the face of formidable obstacles.

A New Rapid Determination Method of Soil Organic Carbon Adsorption Coefficients of Pesticides with Soil Column Liquid Chromatography

Soil column liquid chromatography (SCLC) was developed to determine soil organic carbon adsorption coefficients (E-oc) for chemicals. The uptake by soil of pesticides from water can be conveniently calculated from the related breakthrough curves (BTC). The nine pesticides chosen for determination in this study are soluble ones, with their water solubility ranging from 62 mg/L to Z mg/L. In comparing with existing methods of K-oc, SCLC possesses rapid, online and accurate characteristics.

Prediction and determination of both friction coefficient and forming force on sheet metal deep-drawing

On the basis of the criterion of no-wrinkle, the principle and method of prediction and determination of both friction coefficient and forming force on sheet metal deep-drawing are put forward, and proved it's expedience and practicability. They are suitable for assessment of lubricant properties. Friction coefficient and forming force are a function of material parameter, design parameter and process parameter, especially relative prevent wrinkle blank-holder force. Product of both friction coefficient and prevent wrinkle blank-holder force is only function of process parameter after determining material parameter and design parameter.

The Use of Yanai’s Generalized Coefficient of Determination to Reduce the Number of Variables in DEA Models

This paper proposes a new method to reduce the dimensionality of input and output spaces in DEA models. The method is based on Yanai’s Generalized Coefficient of Determination and on the concept of pseudo-rank of a matrix. In addition, the paper suggests a rule to determine the cardinality of the subset of selected variables in a way to gain the maximal discretionary power and to suffer a minimal informational loss.

Determination of Integrated Molar Absorption Coefficients for Gaseous Phenol Infrared Bands and Influence of Water Vapor on Their Values

The integrated molar absorption coefficients for ν(OH) (3655 cm-1), δ(OH) (Q branch at 1176 cm-1 or whole bands), [ν(CCring) + δ(OH)] (Q branch at 1344 cm-1 or whole bands) and γ(CH) (752 cm-1) were determined at 342 K, by recording infrared spectra of pure gaseous phenol at different partial pressure (from 0 to 33 Pa). The integrated molar absorption coefficients (ε) values were obtained with a good reproducibility and the relative uncertainty on the given values is below 2%. The influence of water on the integrated molar absorption coefficients of phenol has been investigated in a large range of nwater/nphenol values (from 0.5 to 6.1 and from 44 to 94) using distinct setups. The infrared spectra of a gas mixture containing a constant amount of phenol and different amount of water were recorded (closed cell) whereas in dynamic condition (under flow) the water partial pressure was kept constant at 1.3 kPa and the phenol partial pressure was increased from 0 to 30 Pa. It is here demonstrated that, at 342 or 355 K, the presence of water does not affect the epsilon values of δ(OH) and [ν(CCring) + δ(OH)] bands.

Research into Uncertainty in Measurement of Seawater Chemical Oxygen Demand by Potassium Iodide-Alkaline Potassium Permanganate Determination Method

Using the glucose and L-glutamic-acid to prepare the standard substance according to the ratio of 1：1, and the artificial seawater and the standard substance to prepare a series of standard solutions, the distribution pattern of uncertainty in measurement of seawater COD is obtained based on the measured results of the series of standard solutions by the potassium iodide-alkaline potassium permanganate determination method. The distribution pattern is as follows： Uncertainty in measurement is big and not constant at the high end, but small and constant at the low end.

Three industries and wastewater and COD discharge of Beijing

With the swift development of economy, the water quality of Beijing is becoming worse day by day and hampers the sustainable development obviously. In this paper, the current conditions of the municipal wastewater structure in the industrial sectors are analysed and discussed in terms of the indicators, such as direct wastewater\|discharge coefficient, complete wastewater\|discharge coefficient, direct discharge coefficient of COD and complete discharge coefficient of COD, by taking a year of 1990s as the base year. Some countermeasures are studied and the corresponding recommendations are put forward in order to improve the water environment in Beijing. This provides a scientific ground for coordinating the relationship between the aquatic environment and economic growth in this city.

Investigati on sonsimultaneous determination of silver and mercury in catalytic－ligandsub stitution reaction with stopped－flow technique calibrated by synergistic effect

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On a special type of Ma-Minda function

We introduce a primitive class of analytic functions, by specializing in many wellknown classes, classify Ma-Minda functions based on its conditions and their interesting geometrical aspects. Further, study a newly defined subclass of starlike functions involving a special type of Ma-Minda function introduced here for obtaining inclusion and radius results. We also establish some majorization, Bloch function norms, and other related problems for the same class.

Evaluating the relative importance of predictors in Generalized Additive Models using the gam.hp R package

Generalized Additive Models(GAMs)are widely employed in ecological research,serving as a powerful tool for ecologists to explore complex nonlinear relationships between a response variable and predictors.Nevertheless,evaluating the relative importance of predictors with concurvity(analogous to collinearity)on response variables in GAMs remains a challenge.To address this challenge,we developed an R package named gam.hp.gam.hp calculates individual R^(2) values for predictors,based on the concept of'average shared variance',a method previously introduced for multiple regression and canonical analyses.Through these individual R^(2)s,which add up to the overall R^(2),researchers can evaluate the relative importance of each predictor within GAMs.We illustrate the utility of the gam.hp package by evaluating the relative importance of emission sources and meteorological factors in explaining ozone concentration variability in air quality data from London,UK.We believe that the gam.hp package will improve the interpretation of results obtained from GAMs.

A Comparative Study of Two Tree-Based Models for Predicting Flyrock Velocity at Open Pit Bench Mining

Blasting is a cost-effective technique to break hard rock volumes by using explosives in the mining and civil engineering realms. Moreover, although blasting is a designed process and plays an indispensable role in these industries, it can also have multiple adverse environmental impacts. One such effect is flyrock, which poses risks to nearby machinery, and residential structures, and can even lead to injuries or fatalities. To optimize blasting efficiency as well as restrict side effects, prediction of the blast aftereffects is vital. Therefore, the present work focuses on using two machine learning methods to predict the velocity of flyrock in the open pit mine. To address this issue, a comprehensive dataset was gathered from the open pit mine. Then, Decision Tree and Random Forest algorithms were employed to predict flyrock velocity. The Random Forest model demonstrated superior performance compared to the Decision Tree model. Nonetheless, the performance of the Decision Tree model was deemed satisfactory, as evidenced by its coefficient of determination value of 0.83, mean squared error (MSE) of 4.2, and mean absolute percentage error (MAPE) of 5.6%. Considering these metrics, it is reasonable to conclude that tree-based algorithms can be effective in predicting flyrock velocity.

Application of ACP Nonlinear Math in Analyzing Arithmetic and Radiation Transmission Data (Application 1 & 2) [4-21-2024, 820P] (V)

In this study, we explore the application of ACP (asymptotic curve based and proportionality oriented) Alpha Beta (αβ) Nonlinear Math to analyze arithmetic and radiation transmission data. Specifically, we investigate the relationship between two variables. The novel approach involves collecting elementary “y” data and subsequently analyzing the asymptotic cumulative or demulative (opposite of cumulative) Y data. In part I, we examine the connection between the common linear numbers and ideal nonlinear numbers. In part II, we delve into the relationship between X-ray energy and the radiation transmission for various thin film materials. The fundamental physical law asserts that the nonlinear change in continuous variable Y is negatively proportional to the nonlinear change in continuous variable X, expressed mathematically as dα = −Kdβ. Here: dα {Y, Yu, Yb} represents the change in Y, with Yu and Yb denoting the upper and baseline asymptote of Y. dβ {X, Xu, Xb} represents the change in X, with Xu and Xb denoting the upper and baseline asymptote of X. K represents the proportionality constant or rate constant, which varies based on equation arrangement. K is the key inferential factor for describing physical phenomena.

一种快速测定化学需氧量(COD)的方法

提出用混酸来代替单一酸测定废水中的化学需氧量(COD)含量的方法。采用混酸(硫酸∶磷酸=4∶1)、重铬酸钾反应体系,氧化反应时间由标准方法的2h缩短为15min,是原来的1/8。用两种方法分别测试了标准物质所配制的废水和实际废水,经t检验和相关性分析,两种测试方法间不存在显著性差异,相关系数为0.95,相关性良好,同时实验得出本方法的检测限为5.15mg/L。本方法由于具有反应时间短,节省药剂和电费等优点,具有一定的可行性。

用MnSO_4作催化剂开管测定废水COD

本研究介绍了用硫酸锰代替硫酸银作催化剂快速开管测定废水中COD的方法。该方法降低了分析成本 ,且使样品的回流时间缩短到 12min ,而准确度和精密度同标准法基本相同。此法取样量少 ,消解速率快 ,适用于大批量水样的测定。

COD测定方法研究进展

近年来,许多科学工作者针对标准方法测定化学需氧量(COD)存在的问题和不足开展了大量研究工作。本文作者对掩蔽剂、催化剂、氧化剂、消解方法、结果测定方式等方面的研究新进展进行了整理与分析,并作简要综述。

用MnSO_4作催化剂测定废水中的COD

介绍了用 Mn SO4代替 Ag2 SO4作催化剂测定废水中 COD的方法。该方法可降低分析成本 ,且使回流时间缩短为 30 m in,方法的变异系数、回收率分别为 0 .6 5 %和 96 .8%～10 0 .8%

不同浓度范围废水COD检测条件探讨

针对一些废水在处理过程中COD范围差异大，COD测定准确度、精密度低的问题。考察了不同浓度范围影响COD测定的关键性因素，结果显示：在440、600nm处，Cr（Ⅵ）浓度不适会引起COD测定准确度、精密度降低。采用c（1／6KzCr20，）为0．02、0．05、0．5mol／L的重铬酸钾溶液，分别对COD为0-50、50～150、150—1500ms／L的溶液作标线，标线的线性回归系数R^2均〉0．999，平行水样相对偏差为1．19％～2．61％，加标回收率为95．3％-104．4％。