bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance Evaluation of a Pulse Detonation Engine Using Vortex Generators as Obstacles in the Combustion Chamber
Authors: Yadav Mukesh , Jha Avhishek , Bista Manish , Arora BB
Published: September 2020

Propulsion based engines have been known for their exemplary thrust but also for lower fuel efficiency and speed of operation which is limited to subsonic and the level of intermittent vibrations produced. Pulse Detonation Engine (PDE) is similar to a Pulse Jet Engine (PJE) except for the fact that the flame formed inside the combustion chamber of PDE travels at supersonic speed, whereas in PJE, it is subsonic. The supersonic speed of flame front in PDE is because of the detonation wave formed during the combustion of the fuel mixture which is in the order of 2000 m/s and is based on constant volume combustion. A process called Deflagration to Detonation Transition (DDT) can be used for which turbulence has to be created inside the combustion chamber. The obstacles used in this study were vortex generators and the CAD model of the engine and the obstacles assembly was made in SOLIDWORKS 19.0 software. ANSYS (FLUENT) 16.0 was used for the simulation of the combustion inside the combustion chamber using the Species Transport Model for the performance evaluation.
Differences in Gut Microbiota Profiles and Functions Between End-stage Renal Disease and Healthy Populations 
Authors: Wu Ping-Hsun , Lin Ting-Yun , Ho Hsiu J. , Tseng Ching-Hung , Lin Yi-Ting , Liang Shih-Shin , Lee Hei-Hwa , Kuo Mei-Chuan , Hung Szu-Chun , Chiu Yi-Wen , Wu Chun-Ying
Published: September 2020

Background: Patients with end-stage renal disease (ESRD) have extremely high risks of mortality and morbidity, as well as altered gut microbiota and impaired intestinal barrier function. The translocation of gut-derived molecules in ESRD contributes to systemic complications. In this study, we evaluated the gut microbiome difference in ESRD patients compared to age- and gender-matched subjects without kidney disease in discovery and validation cohorts.Results: Compared to controls with normal renal function, an increased α-diversity and distinct β-diversity were found in ESRD subjects. The increase in α-diversity was correlated with protein-bound uremic toxins, particularly hippuric acid. A higher microbial dysbiosis index (MDI) was found in ESRD patients with the following enriched genera: Facealibacterium, Ruminococcus, Fusobacterium, Dorea, Anaerovorax, Sarcina, Akkemansia, Streptococcus, and Dysgonomonas. MDI at the genus level demonstrated highly differentiated accuracies between ESRD and control subjects in the discovery cohort (area under the curve [AUC] of 81.9%) and between ESRD and control subjects in the validation cohort (AUC of 83.2%). On functional enrichment analysis with gut metabolic modules, ESRD subjects presented with increased saccharide and amino acid metabolism when compared with matched controls.Conclusions: An enriched but dysbiotic gut microbiota was presented in ESRD patients, in which the bacteria that were present increase amino acid metabolism linked to the production of protein-bound uremic toxins.
Biodata Mining-based Elucidation of Mechanisms of Hesperetin as a Candidate for Atherosclerosis
Authors: Huang Lianzhou , Huang Zexiu , Chen Yuanqiu , Jin Xin , Xiao Ji , Ren Zhe , Wang Yiliang
Published: September 2020

BackgroundHesperetin, an active ingredient derived from Citrus × aurantium L., possesses a wide range of biological activities, including anti-inflammatory, anti-oxidation, and anti-cancer activity. Notably, hesperetin has been proposed as a candidate for atherosclerosis owing to the lipid-regulating and anti-inflammatory effect, while the underlying mechanisms remains obscure.ResultsIn our present study, the pharmacological and molecular properties of hesperetin were first evaluated to determine the druggability of hesperetin. Subsequently, 53 hesperetin-atherosclerosis crossover targets were collected to establish the protein-protein interaction network. The result of Gene Ontology enrichment analysis indicated that the crossover targets were involved in the regulation of lipid metabolism and inflammatory response. Moreover, the Kyoto Encyclopedia of Genes and Genomes pathway analyses demonstrated that the crossover targets were highly correlated with the pathogenesis of atherosclerosis, such as fluid shear stress and atherosclerosis pathway and the TNF signaling pathway. Finally, an entire hesperetin-target-pathway network was constructed to provide a systematic overview of the pharmacological mechanisms of action of hesperetin against atherosclerosis.ConclusionsThe pharmacological mechanisms of actions of hesperetin against atherosclerosis was unveiled based on biodata mining from the public database and the bioinformatics data analysis-based strategy in this study, contributing to a deeper understanding of the molecular mechanisms of hesperetin in the treatment of atherosclerosis. Based on the results of network pharmacology analysis, we can conclude that hesperetin is surely an excellent candidate for atherosclerosis. We believe our work would be beneficial for further research and development of hesperetin as a natural active ingredient derived from Citrus × aurantium L. for the treatment of atherosclerosis.
ABOUT DARSY’S LAW DURING FLUIDS MOTION IN THE MICRO-CRACKED CHANNELS
Authors: Mammadova Maleyka
Published: September 2020

Firstly it has been experimentally revealed that during fluid motion in the micro-cracked channel and in the equivalent porous medium an unknown additional resistance arises in the scientific technical literature that is the “microcrack-fluid” effect. It has been demonstrated that the determined “microcrack-fluid” effect is the cause of linear Darcy’s law violation in the micro-cracked channels.

It has been revealed in the work that during fluids moving in the microcracked channel there is a critical size of crack for the homogeneous fluid (water, viscous and anomalous fluids) and a hydrodynamic effect as so-called “microcrack-fluid” is manifested.

So for the first time we determined the critical value of opening − hcr on the basis of experimental investigations in cracks. It was found that at h<hcr the anomalous properties are manifested for viscous fluids and rheological parameters are increased for anomalous fluids, and at h≥hcr these effects disappear. It has been established that the reason of the anomalous behavior of fluids in the microcrack with h<hcr opening is the effect occurred in the “microcrack-fluid” system.

It is shown that microcrack with certain opening can be considered as a model but the ultra-low permeable porous medium is nature.

It has been determined that the critical value of the Reynolds number calculated for viscous and abnormal fluids in the microcracked channel and in the equivalent porous medium in the microcrack is Re<1.

The new fact about Darcy’s law violation during fluids flow in microcrack with h<hcr opening has been experimentally revealed i.e. micro-cracked effect of “microcrack-fluid” system is a cause of Darcy’s law violation.

It is recommended to taking into consideration the microcracked effect in the “fluid-medium” system for regulation and creation of the new technical and technological processes in the different branches of industry
DEVELOPMENT OF AN ADVANCED METHOD OF VIDEO INFORMATION RESOURCE COMPRESSION IN NAVIGATION AND TRAFFIC CONTROL SYSTEMS
Authors: Yevseiev Serhii , Abdalla Ahmed , Osiievskyi Serhii , Larin Volodymyr , Lytvynenko Mykhailo
Published: September 2020

The Earth's aerospace monitoring (ASM) systems use state-of-the-art integrated information technologies that include radio-based detection and surveillance systems using telecommunications. One of the main tasks of ASM systems is to increase the efficiency of decision-making necessary for the timely prevention, detection, localization and elimination of crisis situations and their probable consequences. Modern conditions impose stricter requirements for efficiency, reliability and quality of the provided video data. To ensure compliance with the requirements, it is necessary to provide the appropriate capabilities of the onboard equipment. On the basis of the existing information and communication systems it is necessary to carry out: continuous or periodic assessment of a condition of objects of supervision and control; continuous (operational) collection, reception, transmission, processing, analysis and display of information resources. It is proposed to use UAVs (unmanned aerial vehicles) as a means to perform ASM tasks. The time of organizing communication sessions and delivery of information should vary from a few seconds to 2.5 hours. Untimely processing and delivery of a specific information resource in the management process leads to its obsolescence or loss of relevance, which contributes to erroneous decisions. One way to reduce time is to encode the data. To do this, it is proposed to use video compression algorithms. However, based on the analysis of the possibility of modern methods of video information compression, taking into account the specifics of the onboard equipment of the UAV, the coding problem is not completely solved. The research results show the expediency of using an improved method of video information compression to reduce the computing resources of the software and hardware complex of the onboard UAV equipment and to ensure the requirements for efficiency and reliability of data in modern threats to ASM systems as a whole.
CORRECTIONAL STRATEGY AND TACTICS OF EQUILIBRIUM DISORDERS OVERCOMING OF PRESCHOOLERS
Authors: Bochkov Pavel , Moga Nikolay
Published: September 2020

The article describes planning system features of corrective actions for the balance function formation in preschool children with musculoskeletal system disorders. The analysis of the existing planning approaches of physical education and physical rehabilitation is made: the insufficiency of the substantiated scientific methodological bases in planning of corrective actions for balance function improvement in preschool children with musculoskeletal system disorders is found out. The general principles of adaptive physical education planning of preschoolers with musculoskeletal disorders are considered. On this basis, a method of step-by-step planning of equilibrium function purposeful formation was developed, which reflects the logic of five channels stimulating of the postural aplomb system and takes into account the peculiarities of postural deficit in each case. Conclusions present the algorithm of corrective actions planning system, which improves balance function of the specified children category. Research prospects of effective ways of postural deficit overcoming of preschool children with musculoskeletal system disorders are briefly marked.
INTERRELATIONS BETWEEN GROWTH DIFFERENTIATION FACTOR 15, P-SELECTIN AND GALECTIN-3 AND CLINICAL COURSE IN PATIENTS WITH ARTERIAL HYPERTENSION AND TYPE 2 DIABETES MELLITUS
Authors: Bilchenko Anton , Vysotska Кaterina
Published: September 2020

The aim of our study was to determine the base levels of Growth Differentiation Factor 15, P-selectin and Galectin-3 in blood plasma in patients with AH and T2DM and to assess their association with the diseases clinical course.

Materials and methods. A total of 121 patients were included in our study (60 female and 61 male, mean age 64.7±10.6 years, with AH and/or T2DM).

Patients were divided into three groups: 1st group with AH only (51 patient), 2nd group with AH and T2DM (57 patients) and 3rd group with T2DM only (13 patients, control group). GDF-15, Galectin-3 and P-selectin tests were performed using standard enzyme-linked immunosorbent assay kits (ELISA).

Results. Compared with AH without T2DM and T2DM only groups, AH with T2DM group had a statistically significant higher level of GDF-15. Grade 3 hypertension group had a significantly lower level of GDF-15 compared with Grade 1&2 hypertension groups. P-selectin mean level was significantly higher in Grade 3 hypertension group GDF-15 compared with Grade 1&2 hypertension groups. We observed weak correlation between Galectin-3 and GDF-15 in blood plasma, which was confirmed by linear regression analysis.

Conclusions. A combination of hypertension and type 2 diabetes mellitus revealed a significant increase of GDF-15 levels in compare with patients with only hypertension or type 2 diabetes mellitus, which may be due to a greater response to oxidative stress and low-intensity systemic inflammation.

P-selectin mean level was higher in patients with grade 3 hypertension, which reflects a greater platelet activation as a part of the systemic inflammatory response.

Galectin-3 mean level was higher in patients with stage 3 hypertension compared with patients with stages 1 and 2 due to possibly more pronounced fibrosis progression.
COMPARATIVE ASPECTS OF PLACENTAL DYSFUNCTION IN WOMEN USING DIFFERENT METHODS OF CONTRACEPTION IN ANAMNESIS
Authors: Lubkovska Oleksandra
Published: September 2020

The aim. To reduce the incidence of perinatal pathology in women who have used various methods of contraception, based on the study of the functional state of the fetoplacental complex (FPS), as well as improving diagnostic measures and tactics of pregnancy.

Materials and methods. 140 pregnant women were studied with their division into control and 3 test groups depending on the method of contraception in the anamnesis, using clinical, laboratory and instrumental research methods during pregnancy and childbirth.

Results. The study found that women with a history of intrauterine contraception (IUC), in contrast to combined oral contraception (COC) and combined oral contraception containing folate (COC+F), had a higher incidence of complications during pregnancy and childbirth, as well as fewer newborns with a satisfactory condition at birth. Assessment of folic acid levels at 6-8 weeks of gestation showed significantly better results among women with a history of COC+F, compared with IUC and COC. In the group of women with IUC in the anamnesis, significantly worse mean endocrinological values prevailed, and there was also a greater number of pregnant women with disorders of fetal-placental blood flow. More pronounced dystrophic changes in the placentas of women in this group were pathomorphologically confirmed.

Conclusions. The presence in the anamnesis of IUC is accompanied by a high proportion of pregnant women with various pathological conditions and is a risk factor for FPS dysfunction. The use of COC+F in the anamnesis is the best option for women of different risk groups.
Los fundamentos de posibilidad de una educación política desde la perspectiva kantiana
Authors: Vallejo Merino Isabel Cristina
Published: September 2020

El artículo presenta algunos de los fundamentos de posibilidad de una educación política desde el corpus kantiano. Para esto, tiene como objetivos 1) interpretar lo que entiende Kant por educación y su relación con la virtud a través del concepto de carácter de índole moral; 2) analizar la relación del carácter con el republicanismo; y 3) comprender la manera como se vincula esta forma de gobierno con el juicio estético. Lo anterior, se realizó con base en el enfoque interpretativo y el método del análisis textual. Se encuentran como resultados, que la formación del carácter de índole moral resulta crucial para una educación política basada en la teoría del filósofo de Königsberg, además se prueba, mediante los criterios de objetividad, universalidad y necesidad, que el republicanismo es la mejor forma de gobierno para el carácter moral y por último, se enuncian aquellos fundamentos de posibilidad de una educación política, primero desde una perspectiva antropológica, segundo, desde un plano metafísico y tercero, desde el fortalecimiento del juicio estético. Se concluye que, el republicanismo es posible, esperable y necesario, ya que es el más acorde con el último fin de la educación, el de la formación del carácter de índole moral.
The role of genomics and genetics in pulmonary arterial hypertension
Authors: Swietlik Emilia M , Gräf Stefan , Morrell Nicolas W
Published: September 2020

[No abstract. Showing first paragraph of article]Although pulmonary hypertension (PH) had been recognised for centuries, it was not until the invention of cardiac catheterisation in the 1950s that enabled an accurate gene encoding bone morphogenetic protein receptor type 2, in patients with familial and clinical diagnosis. The discovery of heterozygous germline mutations in BMPR2, the idiopathic forms of pulmonary arterial hypertension (PAH) was another breakthrough in understanding the disease and initiated a new era in care of patients with this condition.
The lamp of medicine of Ancient Egypt is still burning
Authors: Butrous Ghazwan , Maron Bradley , Yacoub Magdi
Published: September 2020

[No abstract. Showing first paragraph of article]In the land of Ancient Egypt, where the Pharaonic civilization flourished, one can encounter sophisticated methods of treating human illnesses. The Ancient Egyptians considered a disease and its treatment as a part of the divine intervention . The Biblical text of the Passover story tells that the divine can send a series of ten plagues, most are diseases that affected various aged groups (Exodus 7:8-12:30; Psalm 77:42-51; 104:26-36). Not only were surgery and medicine practiced with care some 5000 years ago; the Pharaonic public health systems were innovative, providing water and removing waste in many places.
Application of PCA-K-means++ combination model to construction of light vehicle driving conditions in intelligent traffic
Authors: Guo Shuqing , Wu Kangkai , Zhang Guoqing
Published: September 2020

The construction of typical driving condition of vehicles in line with the actual road traffic conditions in China requires the selection of the same vehicle for two months to collect driving data and the obtention of 496000 driving condition data of light vehicles. The sample data are preprocessed by using multivariate statistical theory and MATLAB. After the elimination of abnormal data, the effective data are extracted before being divided into 3020 kinematic segments. Then, it takes a principal component analysis to reduce the dimension of the characteristic parameter matrix. Through K-means++ clustering algorithm, the six principal components obtained by principal component analysis are clustered into two categories. Then the typical kinematic segments are selected from various fragment libraries by using correlation coefficient method, so as to construct a typical driving condition of the vehicles in a certain city. With the application of PCA-K-means and PCA-K-means++ clustering algorithm, a driving condition curve with a duration of 1200s is constructed before its effectiveness and accuracy being compared and analyzed. The results show that the error rate of driving condition between sample data and driving condition constructed by PCA-K-mean++ clustering algorithm is less than 6 % and the error rate of average speed and acceleration standard deviation is less than 1 %. The correlation degree between working condition curve constructed by PCA-K-means ++ clustering algorithm and sample data is increased by 4.08 %. The proportion of deceleration time and idle time in vehicle driving state is obviously different, which indicates that PCA-K-means++ is a better way to solve the problem and the clustering algorithm can effectively construct the driving condition curve of light vehicles suitable for local cities.
Non-reflecting boundary used for simulating ground born vibrations caused by the moving train loads
Authors: Mekonnen Aynalem
Published: September 2020

In the very early the problem of train induced ground vibrations has received considerable attention, due to the sever effect of wheel-rail interaction force on the railway infrastructures and nearby buildings. To predicate and mitigate such vibration problems, three dimensional finite element packages are most recently and widely used numerical method, although method of achieving non-reflecting boundary condition to avoid the boundary-related wave reflection is still problem. In most case, wide finite element models far from the field that is capable of minimizing the reflection is favored by researchers. However, modelling wide finite element mesh is time consuming and it is the most difficult issue to determine whether the cross-sectional model is sufficient. Thus, other schemes such as the material property of the non-reflecting soil model have to incorporate to minimize the size in the cross-sectional directions. Hence, a parametric study by using ABAQUS is conducted in this paper to identify the paramount important parameters of the soil that may affect the boundary-related wave reflection caused by the moving train loads. With this perspective, the finite element model is divided into two regions, called the near-field and far-field. The near-field includes the moving train loads and other geometric/material properties of the entire railway infrastructure represented by the finite element, while the far-field is covered the non-reflecting model placed at the truncated boundaries. To this end, a systematic study is carried out to examine the sensitivity of damping ratio, length, Young’s modulus and Poisson’s ratio of the boundary in suppressing the reflections. The results demonstrate the beneficial role of the boundaries and their parameters in suppressing the reflection, if the paramount important parameters are properly selected.
A fault pattern recognition method for rolling bearing based on CELMDAN and fuzzy entropy
Authors: Liu Ning , Liu Bing , Wei Jiaxin , Xi Cungen
Published: September 2020

The vibration signal of rolling bearing often has the characteristics of strong noise, nonlinearity and non-stationary, so the accurate fault feature information cannot be obtained directly from the measured vibration signal. Therefore, a fault pattern recognition method for rolling bearing based on complete ensemble local mean decomposition with adaptive noise (CELMDAN) and fuzzy entropy is deeply studied. Firstly, the reason of modal aliasing existing in local mean decomposition (LMD) method is explained. According to the previous methods for modal aliasing processed in other methods, CELMDAN method is proposed. The experiment proves that the proposed CELMDAN method can better handle the vibration signals with nonlinear and non-stationary. Then, the principle and properties of the fuzzy entropy are introduced in detail, and the fault feature of rolling bearing can be reflected. Finally, extreme learning machine (ELM) is introduced as the pattern recognition method based on the effective fault feature of rolling bearing. Combined with the verification of experimental signal, it is proved that the proposed method can extract the fault features of rolling bearing accurately and effectively, and the fault pattern recognition of rolling bearing can be realized.
Fault severity assessment of rolling bearings method based on improved VMD and LSTM
Authors: Liang Zhihua , Cao Jiangtao , Ji Xiaofei , Wei Peng
Published: September 2020

In order to solve the problem of selection of appropriate wavelet basis function and clearly show the physical meaning of Empirical Mode Decomposition (EMD), an improved Variational Mode Decomposition (VMD) method with Long Short-Term Memory (LSTM) neural network is proposed. With the Cuckoo Search (CS) algorithm, the central frequency updating rules of VMD are optimized. And the low efficiency and local optimum problem is avoided. Meanwhile the decomposition layer number is found by the instantaneous frequency theory. For improving the prediction accuracy in traditional regression prediction methods, a LSTM neural network is designed for regression prediction of time sequence characteristics. The proposed method is implemented on actual bearings data which is derived from the bearing laboratory of Case West Reserve University in the United States and the University of Cincinnati Bearing Data Center. The experimental results showed that the improved VMD method was more robust and more accurate than the other traditional methods. And it has some practical value for real application and guiding significance for theory.
Effects of non-meat proteins on the quality of fermented sausages
Authors: Velemir Ana , Mandić Snježana , Vučić Goran , Savanović Danica
Published: September 2020

Introduction. Non-meat proteins are widely used in meat processing. In our study, we analyzed the effects of whey and soy protein isolates on the physicochemical and sensory properties of domestic fermented sausage.

Study objects and methods. Five groups of sausages were traditionally fermented under industrial conditions. The sausage group without the additives was labelled the control, while other sausages were manufactured with the addition of 0.5% and 1.5% protein isolates of whey and soybean. Using a quantitative descriptive test, we assessed the sensory characteristics of the sausages and instrumentally determined their color, hardness, water activity (aw), and pH.

Results and discussion. The proteins added to fermented sausages improved emulsification, texture, as well as water and fat binding capacity, which was confirmed by the results for hardness. Using a 0.5% soy protein isolate resulted in a firmer product. The additives had a minor effect on the color: the samples with the additives had a slightly lower L* value, and those with a soy protein had higher yellowness (b*).

Conclusion. Using the additives did not have a significant effect on the chemical composition and overall sensory quality of all tested samples (P > 0.05).
Evaluation of environmental indicators of RO seawater desalination: case study coastal strip of Hormozgan province, Iran
Authors: Jouzdani Somayeh Mohammadi , Zerafat Mohammad Mahdi , Arasteh Peyman Daneshkar , Vagharfard Hassan
Published: September 2020

In recent years, desalination has been turned into a fresh water supply as a solution in some areas which suffer from water shortage. Desalinated water as an industrial product causes environmental problems. The objectives of this study are investigating environmental sustainability indicators related to seawater desalination via reverse osmosis (SWRO) on the coastline of Hormozgan province to provide a better insight for current and future water and energy demands related to this alternative. The selected indicators are specific energy consumption, seawater withdrawal, and brine volume in desalination, fuel consumption, carbon emission and water withdrawal in electric power generation. Using a solution-diffusion model, the direct indicator of energy consumption was obtained as used to calculate indirect indicators from the energy generation sector. Analysis of results indicates that desalination can lead to out-of-area side effects resulting from fuel type consumed and the practical power of the power plant, in addition to the regional environmental effects that are mostly affected by total dissolved solids of feed water. Based on the results, the environmental issues should be considered for the regions where desalination was planned as the most feasible alternative for water supply. This result can help policymakers to manage water supply and demand for sustainable development appropriately.
Evaluating the performance of low impact development practices in urban runoff mitigation through distributed and combined implementation
Authors: Samouei Sina , Özger Mehmet
Published: September 2020

Rapid urbanization and increasing impervious surfaces in cities lead to a serious reduction in infiltration rate of the surface and cause challenges in stormwater management. The Low Impact Development (LID) concept is considered as a potential solution for sustainable urban growth by contributing in urban flood mitigation. However, its effects on hydrologic response of the urbanized catchments, especially in broad scale implementation, are not fully understood and practically examined. In this study a hydrologic-hydraulic model of a small catchment was developed in EPA storm water management model (SWMM) program and calibrated and validated through field measurements. The hydrologic response of the catchment was investigated after replacing proportions of impervious surfaces with combinations of LID practices such as green roof, permeable pavement and bio-retention cell, through four land cover conversion scenarios and under five different designed storm events. The simulation results which are derived by comparison of outflow hydrographs between each scenario and conventional drainage system indicated that implementing 5–20% of LIDs has a noticeable impact on runoff peak flow and volume reduction, especially in storm events with shorter return periods. Also the runoff reduction trends show a linear response due to the increase in LID implementation ratio in the study area.
Response of redox zonation to recharge in a riverbank filtration system: a case study of the Second Songhua river, NE China
Authors: Su Xiaosi , Chen Yaoxuan , Lyu Hang , Shi Yakun , Wan Yuyu , Zhang Yiwu
Published: September 2020

Bank filtration induced by groundwater pumping results in redox zonation along the groundwater flow path. Besides the river water, recharge from other sources can change local redox conditions; therefore, redox zonation is likely to be complex within the riverbank filtration (RBF) system. In this study, hydrodynamics, hydrogeochemistry, and environmental stable isotopes were combined together to identify the redox conditions at an RBF site. The recharge characteristics and redox processes were revealed by monitoring the variations of water level, δ2H and δ18O, and redox indexes along shallow and deep flow paths. The results show that local groundwater is recharged from river, regional groundwater, and precipitation. The responses of redox zonation are sensitive to different sources. In the river water recharge zone near shore, O2, , Mn(IV), Fe(III), and are reduced in sequence, the ranges of each reaction are wider in deep groundwater because of the high-velocity deep flow. In the precipitation vertical recharge zone, precipitation intermittently drives O2, , and organic carbon to migrate through vadose zone, thereby decreasing the groundwater reducibility. In the regional groundwater lateral recharge zone in the depression cone, the reductive regional groundwater is continuously recharging local groundwater, leading to the cyclic reduction of Mn(IV) and Fe(III).
A field investigation on rill development and flow hydrodynamics under different upslope inflow and slope gradient conditions
Authors: Tian Pei , Pan Chengzhong , Xu Xinyi , Wu Tieniu , Yang Tiantian , Zhang Lujun
Published: September 2020

Few studies focus on the quantitative impact of upslope inflow rate and slope gradient on rill development and erosion processes. Field plot experiments under varying inflow rates (6–36 L min−1m−1) and slope gradients (26, 42 and 57%) were conducted to address this issue. The results showed soil loss rates significantly demonstrated temporal variability in relevance to the rill developing process. Rill erosion and its contribution to soil loss increased with increasing inflow rates and slope gradients by power functions. There was a threshold inflow discharge (12–24 L min−1m−1), under which, rill erosion became the dominant erosion pattern. At the initial stage, downcutting of rill bottom and headward erosion were obvious, whereas rill broadening was significant at the actively rill developing period. Rill density increased with slope gradient increasing from 26% to 42%, and then decreased. For the 57% slope under high inflow rates (24–36 L min−1m−1), gravity caused an increase in the collapse of rills. Mean rill width increased with increasing inflow rates but decreased as slope gradients increased, while mean rill depth increased with increasing inflow rates and slope gradients. Stream power and rill flow velocity were the best hydrodynamic parameter to simulate rill erosion and rill morphology, respectively.
Multi-time scale co-integration forecast of annual runoff in the source area of the Yellow River
Authors: Zhang Jinping , Li Hongbin , Sun Bin , Fang Hongyuan
Published: September 2020

In order to reveal the multi-time scale of rainfall, runoff and sediment in the source area of the Yellow River and improve the accuracy of annual runoff forecast, the Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN) method is introduced to decompose the measured rainfall, runoff and sediment data series of the Tangnahai hydrological station in the source area of the Yellow River of China. With the co-integration theory, two new error correction models (ECMs) for the forecast of annual runoff in the source area of the Yellow River are constructed. The application of these two methods solves the problem of pseudo-regression caused by nonlinearity and non-stationary of hydrological time series. The results show that rainfall, runoff and sediment in the source area of the Yellow River have multi-time scales and the component sequences have co-integration relationships. For two new ECMs, the CEEMDAN component ECM has better forecast accuracy than the original sequence one. The relative error of all forecasted values is less than 15% except 2009, and the accuracy has reached level A.
Analysis of total monthly precipitation of Susurluk Basin in Turkey using innovative polygon trend analysis method
Authors: Ceribasi Gokmen , Ceyhunlu Ahmet Iyad
Published: September 2020

The effects of climate change caused by global warming can be seen in changes of climate variables such as precipitation, humidity, and temperatures. These effects of global climate change can be interpreted as a result of the examination of meteorological parameters. One of the most effective methods to investigate these effects is trend analysis. The Innovative Polygon Trend Analysis (IPTA) method is a trend analysis method that has emerged in recent years. The distinctive features of this method compared with other trend methods are that it depends on time series and can compare data series among themselves. Therefore, in this study, the IPTA method was applied to total monthly precipitation data of Susurluk Basin, one of Turkey's important basins. Data from ten precipitation observation stations in Susurluk Basin were used. Data were provided by the General Directorate of State Meteorology Affairs. The length of this data series was 12 years (2006–2017). As a result of the study, since there is no regular polygon in IPTA graphics of each station, it is seen that precipitation data varies by years. While this change is seen increasingly at some stations, it is seen decreasingly at other stations.
Association between concentrations of chromium in drinking water and mortality due to suicide in Alabama
Authors: Whitaker Caitlyn C. , Cates Marshall E. , Cruthirds Danielle L. , Gorman Gregory S.
Published: September 2020

Preclinical studies and clinical data from case series and placebo-controlled trials suggest that chromium might have antidepressant effects. We conducted an observational study in order to assess the association between concentrations of chromium in drinking water and mortality due to suicide in Alabama. Publicly available databases were used to determine both county-level concentrations of chromium in drinking water and county-level rates of mortality due to suicide in the years 2005–2015. Data analyses comparing county-level concentrations of total chromium in drinking water with mortality rate due to suicide were conducted using a two-tailed nonparametric Spearman's rank correlation, with statistical significance set at p ≤ 0.01 and 99% confidence interval. Sub-analyses were conducted examining males, females, whites, and blacks/other minorities. There were no statistically significant findings concerning concentrations of chromium and suicide rate in the general population (p = 0.35, r = −0.12); however, there was a statistically significant inverse relationship between the concentration of chromium and suicide deaths in whites (p = 0.009, r = −0.32). There were no statistically significant findings in the remaining demographic subgroups. Chromium in drinking water might have a protective effect against mortality due to suicide, at least in the Caucasian population.
Hydrological principle behind the development of series of bunds in ancient tank cascades in small catchments, Sri Lanka
Authors: Perera K. T. N. , Wijayaratna T. M. N. , Jayatillake H. M. , Manatunge J. M. A. , Priyadarshana Tilak
Published: September 2020

Utilisation of water harvesting systems of ancient origin for present-day requirements can be seen in many regions of the world. The adoption of ancient tank cascades as the smallest hydrological unit of river basin development in Sri Lanka is such a practice. However, these systems are associated with unsuccessful experiences in agricultural performance while being vulnerable to both floods and droughts. Therefore, the identification of principles behind the development of cascades is vital. This study reviewed historical evidence, definitions, terminologies and studies on the development and operation of these systems. A hypothesis was then developed and tested for a specimen tank cascade using a HEC-HMS model. The routing mechanism showed that the existence of a series of bunds increases the robustness of the tank systems for flood inflows. Accordingly, the development of tank cascades is a technique used to regulate experienced peak inflows with limited technologies. This principle and the new cascade definition developed should be prime considerations along with the focus on storage when restoring the tanks in cascades. The findings provide insights into the crucial need for identifying development principles behind the ancient hydrological systems in any region of the world to adapt them sustainably.
A simplified method to improve water distribution and application uniformity for sprinkler irrigation on sloping land: adjustment of riser orientation
Authors: Hui Xin , Yan Haijun , Zhang Lin , Chen Junying
Published: September 2020

To improve the water application uniformity for sprinkler irrigation on sloping land, indoor tests were conducted on an artificial slope (slopes of 0, 0.05, 0.10 and 0.15) to evaluate the effects of two riser orientations, vertical (VO) and perpendicular (PO) to the slope, on the uniformity of sprinkler rotation, radius of throw, water distribution of an individual sprinkler and the overlapped water application uniformity (WAU). Compared with the VO, the PO could effectively improve the water distribution on sloping land and minimize the risk of soil erosion. Additionally, the PO was superior in the WAU, and a rectangular arrangement could dramatically enhance the WAU at smaller sprinkler spacing, while larger acceptable sprinkler spacing was accepted in a triangular arrangement. The riser orientation and sprinkler spacing had the most significant effect on the WAU, followed by the slope and sprinkler arrangement, suggesting that the adjustment of riser orientation or sprinkler spacing was helpful in improving the WAU. However, from the aspects of investment cost and installation convenience for irrigation projects, the method of PO was recommended. Therefore, when designing the sprinkler irrigation systems on the slope, choosing PO is the simplest and most effective way to achieve good irrigation uniformity.
Seasonal patterns in phytoplankton growth, composition, and predominance in relation to water quality at Northwest El-Manzala Lake, Egypt
Authors: Deyab Mohamed , Abu Ahmed Seham , Ward Fatma
Published: September 2020

The physicochemical properties and phytoplankton community structure were investigated seasonally at four stations representing Northwest El-Manzala Lake, Egypt, during 2019. Results indicated wide local and seasonal variations in the concentrations of various physicochemical parameters. There was a noticeable variation in levels of nitrogen and phosphorus forms; higher ammonia, nitrite, and nitrate contents of 11.6 (in autumn), 2.28 (in winter), and 2.32 mg L-1 (in autumn), respectively, were detected at Shatt Greba (site IV). Total-P and ortho-P exhibited higher levels of 7.14 and 0.96 mg L−1, respectively, at site IV in summer. The greatest amounts of sodium, potassium, calcium, barium, and lithium were 102.88 g L−1, 9.12 g L−1, 8.56 g L−1, 345.8 mg L−1, and 1.62 mg L−1, respectively, during summer. Two-way ANOVA presented a highly significant local and seasonal effect of physicochemical parameters on phytoplankton biomass. There were high levels of autumn algal biomass (65.96 mg L−1) and low levels of winter algal biomass (32.28 mg L−1). Cyanophyta, Chlorophyta, and Pyrrophyta dominated in the autumn, whereas Bacillariophyta dominated in the winter. Cyanophyta and Pyrrophyta biomass showed high local variations in contrast to Bacillariophyta and Chlorophyta. The species diversity index revealed that the study area was mildly to moderately polluted water.
Simulation of nitrogen and phosphorus pollution in typical agricultural and forested basins as well as relevant reduction effect based on SWAT model
Authors: Li Wu , Zhe Chen , Hui-ying Liu , Dun-qiu Wang
Published: September 2020

Non-point source nitrogen and phosphorus pollution is a critical threat to aquatic ecosystems and a potential risk to drinking water safety. To precisely control nitrogen and phosphorus pollution in the river basin, in this study, we identified key pollution areas of the river basin, analyzed the main characteristics of pollution sources as well as their contribution to the river basin pollution, and conducted simulation analysis on reduction measures based on the SWAT model. The results showed the following. (1) The simulation effect of the calibrated model was good, and sub-basins 3, 39 and 96 were the key source areas, the main sources of pollution were combined pollution from livestock and poultry breeding and planting industry. (2) Crops had the largest input and output for both nitrogen and phosphorus, the output of which was 6,137.8 t/a and 562.4 t/a respectively. The urban point sources had the highest output rates of nitrogen and phosphorus, 75.7% and 67.5% respectively. (3) With the optimal combination of reduction measures, nitrogen and phosphorus were reduced by 1,438.9 t and 85.3 t respectively, i.e., the reduction rates were the highest. The reduction effect for total nitrogen was better than that for total phosphorus.
Use of bottom slots and submerged vanes for controlling sediment upstream of duckbill weirs
Authors: Tajari Mahla , Dehghani Amir Ahmad , Meftah Halaghi Mehdi , Azamathulla Hazi
Published: September 2020

Duckbill weir is one of the water level control structures in irrigation networks, which is of interest to many engineers. Sediments transported in irrigation networks that accumulate upstream of duckbill weirs cause problems in operation, and affect the upstream water level. In this paper, submerged vanes and bottom slots are investigated for flushing the sediment downstream of the said weir. The experiments were conducted in a rectangular flume, 12 m long, and 0.6 m wide. The vanes placed in four sections were perpendicular to the sidewall. Flow-3D software was used for simulation of flow and sedimentation patterns. The results showed that submerged vanes create a secondary flow which is very useful for flushing the sediment, especially in the value of (H is head over the sidewall and P is the weir height). Further, the results showed duckbill weir efficiency (which is defined as the ratio of sediment trap to flow capacity of the weir) is as high as 47% (for values of H/P = 0.1–0.5 and total models). Finally, image processing results showed a maximum relative error of 14.4% for the simulation of the sediment pattern with Flow-3D software.
Experimental study on filtration effect of oilfield sewage based on new polyurethane modified materials
Authors: Liu Bingcheng , Li Hongsong , Liu Ning , Jia Wenguang
Published: September 2020

In the process of oilfield wastewater treatment, the polymer-modified materials with special wettability have been recognized by many scholars for their high filtration efficiency and good adsorption effect. In this paper, we used micro-computed tomography scanning and infrared scanning technology to further explore the internal structure and surface chemistry of polyurethane modified materials and then established an experimental platform for the filtration performance of polyurethane modified materials. The change of suspended solids concentration and oil content in the sewage was tested under different filtration rate, filter layer thickness, and water quality. The results showed that the porosity of the filter material and the oil-absorbing material was 65.85% and 56.03% respectively, and the difference in the number of oxygen-containing functional groups on the surface of these two materials indicated different adsorption force for sewage impurities. And the polyurethane modified materials had good filtration performance. Through these experiments, we demonstrated that the quality of water filtrated by the polyurethane modified materials met the requirements of the ‘National Comprehensive Wastewater Discharge Standards’, and the filtration efficiency for suspended particles and oils in oily sewage was higher than 80%. These materials have important practical significance for the harmless treatment of oily sewage.
La(OH)3 nano-rods/polyacrylonitrile nanofibers: fabrication, characterization and application for phosphate removal
Authors: He Jiaojie , Yang Yue , Xu Yuhong , Wang Zichuan , Xu Bing , Huang Yuheng , Yang Liwei
Published: September 2020

In this study, an excellent phosphate adsorbent was prepared for removing phosphate to an extremely low concentration. The La(OH)3 nano-rods stabilizing in polyacrylonitrile (PAN) nanofibers (PLNFs) were prepared by electrospinning and a subsequent in situ precipitation. PAN nanofibers were employed as the matrix of the composite nanofibers, where the well-dispersed La(OH)3 nano-rods were encapsulated as the active species for highly efficient phosphate capture owing to the strong binding between phosphate and lanthanum. On account of the nano-structure, the maximum phosphate adsorption capacity was 151.98 mg P/g (La), much higher than the result of La(OH)3 nano-crystal, produced by precipitation without PAN or any organic surfactants. Moreover, the PLNFs could remove phosphate (2 mg P/L) to an extremely low concentration within 20 min, which could lead to a nutrient deficient condition to protect water quality and ecosystem. The optimization of PLNFs design was implemented through parameter adjustment of electrospinning. Lanthanum salt content, humidity, concentration of solution and applied voltage were chosen to analyze the influences on the composition, diameter and morphology of the nanofibers, giving the result that the most effective adsorbent was the PLNFs with spider-web-like nano-structures.