Groundwater is critical for supplying drinking water to billions of people worldwide.However,their excessive permeability makes them more vulnerable to retaining and spreading contamination.Assessing groundwater vulne...Groundwater is critical for supplying drinking water to billions of people worldwide.However,their excessive permeability makes them more vulnerable to retaining and spreading contamination.Assessing groundwater vulnerability is crucial for sustainable management,as it aids in reducing the risks associated with contamination of this valuable resource.As a result,the primary aim of this paper is to critically review and synthesize recent advances in groundwater vulnerability and risk assessment using hydrogeochemical parameters.A summary of groundwater contamination,sources,and consequences is presented.Information on hydrogeochemical factors and groundwater vulnerability is summarised.A review of the most commonly used groundwater vulnerability assessment methods is covered.It also covers the assessment of groundwater vulnerability using hydrogeochemical parameters and statistical approaches.Furthermore,these approaches are supported by global case studies.Finally,the limitations,conclusion,and future recommendations are presented.It can be concluded that integrating hydrogeochemical parameters with groundwater vulnerability models is an effective method for assessing the risk of groundwater contamination and developing management plans.Researchers in the fields of health,earth sciences,environmental studies,and water sciences will find this comprehensive review to be a valuable reference,as it offers an in-depth understanding of the current knowledge on the integration of hydrogeochemical parameters in groundwater vulnerability and risk assessment studies.展开更多
This study was conducted to evaluate four different parental oriental varieties with their F1 crosses to estimate inheritance of some morphological traits, such as plant hight, number of leaves, total dry weigh and ch...This study was conducted to evaluate four different parental oriental varieties with their F1 crosses to estimate inheritance of some morphological traits, such as plant hight, number of leaves, total dry weigh and chemical compounds, especially nicotine and sugars during sun-curing period. The oriental varieties Kozarsko 541, Plovdiv 50 and Krumovgrad 17 from Bulgaria and Basma Xanthi 101 from Greece and their respective crosses with Basma Xanthi 101 were studied. The study was set up in 2014 and 2015 in experimental field of the Tobacco and Tobacco Products Institute, Plovdiv, using randomized block design with four replications. Common agricultural practices were applied during the growing season. The result indicated that in hybrid combination with parental varieties Kozarsko 541 and Plovdiv 50, except total dry weight, additive gene effects are important for traits height of plant and number of leaves. Height of plant and number of leaves are inherited partially dominant to parent with higher value and total dry weight inheritance was over dominant. In hybrid combination Krumovgrad 17 x Basma Xanthi 101, inheritance of the plant height and leaves number were over dominant type. Total dry weight is inherited partially dominant. In a word, prevailing mode for inheritance of plant hight and total dry weight was the over dominance and for number of leaves it was partial dominance. In sun-curing with yellowing stage, nicotine decreased and sugars increased in all tested varieties with a highest percentage in variety Kozarsko 541 （nicotine） and Krumovgrad 17 （sugars）.展开更多
Quantum chemical parameters of 10 amino acids with D- and L-configurations were firstly calculated with semi-empirical AM1 method. Furthermore, the relationship between molecular structures of D-, L-amino acids and t...Quantum chemical parameters of 10 amino acids with D- and L-configurations were firstly calculated with semi-empirical AM1 method. Furthermore, the relationship between molecular structures of D-, L-amino acids and their sweetness were observed. The results show that upon different configurations of amino acids, the sweetness is relative with their formation heat, dipole moment, energy gap of frontier orbital and other parameters. The formation heats of the same amino acids possessing D- and L-configurations are different except glycine. The algebraic value of D-amino acid is generally larger than that of corresponding L-configuration with only one except of tyrosine. The dipole moment of D-amino acid is generally larger than that of corresponding L-amino acid except tyrosine and lysine. The lowest unoccupied orbital energy （ELUMO） of D-amino acid is higher than that of corresponding L-configuration except phenylalanine. △E of D-amino acid is larger than that of L-amino acid except histidine, phenylalanine and lysine. The larger gap will have advantage for its matching with frontier orbital energy of human protein acceptor, which strengthens the interaction between D-amino acid and sweet taste acceptor. Besides, the changing rules of these parameters are generally identical.展开更多
Objective: The study aims to investigate some physical and technological parameters of varieties of maize collected from the most representative areas of maize production in the southern part of Benin, and mainly used...Objective: The study aims to investigate some physical and technological parameters of varieties of maize collected from the most representative areas of maize production in the southern part of Benin, and mainly used by the populations of those areas. Method: The chemical composition, physical and technological characteristics of the grains were determined using standard methods. Results: The results showed that the weight of 1000 grains ranges from 158.01 to 305.12 g, the length from 0.79 to 1.81 cm, the average width from 0.74 to 1.51 cm, thickness from 0.36 to 0.85 cm and density from 1.07 to 1.25. Regarding the technological parameters, the hardness of the grains before and after cooking was between 16.78 and 47.20 kgf, and 0.23 and 0.71 kgf respectively, while the cooking time varies from 71.00 and 158.33 mn. There was a positive and significant correlation (r = 0.405;p < 0.026) between the hardness after cooking and the weight of 1000 grains, between the hardness after cooking and grain width (r = 0.460;p < 0.011). A positive and highly significant correlation (r = 0.527, p < 0.003) was also observed between the hardness after cooking and the grain length, between the hardness after cooking and the thickness of grain (r = 0.476, p < 0.008), and between the grain density and the weight of 1000 grains (r = 0.481, p < 0.007). A positive and highly significant correlation (r = 0.923, p < 0.000) was also observed between maize grain length and width, and between grain length and grain thickness (r = 0.764, p < 0.000) and between the width and thickness (r = 0.764, p < 0.000). On the other hand, a significant negative correlation (r = -0.394, p < 0.031) was found between the hardness before cooking and the thickness and between the hardness before cooking and sphericity index (r = -0465*, p Conclusion: Through its chemical and technological characteristics the maize constitutes an important raw material for many culinary recipes in West African region.展开更多
Chemical bond parameters, that is, bond covalency, bond valence, macroscopic linear susceptibility, and oxidation states of elements in Sr3MRhO6(M-Sm, Eu, Tb, Dy, Ho, Er, Yb) have been calculated. The results indicat...Chemical bond parameters, that is, bond covalency, bond valence, macroscopic linear susceptibility, and oxidation states of elements in Sr3MRhO6(M-Sm, Eu, Tb, Dy, Ho, Er, Yb) have been calculated. The results indicate that the bond covalency of M-O decreases sharply with the decrease of ionic radius of M3+ from Sm to Yb, while no obvious trend has been found for Rh-O and Sr-O bonds. The global instability index indicates that the crystal structures of Sr3MrhO6(M=Sm, Eu, Tb, Dy, Ho) have strained bonds.展开更多
The comparative study is designed to monitor the physico-chemical and biological quality of the water upstream and downstream of the Manantali hydroelectric dam. The physico-chemical parameters are sampled at 3 measur...The comparative study is designed to monitor the physico-chemical and biological quality of the water upstream and downstream of the Manantali hydroelectric dam. The physico-chemical parameters are sampled at 3 measuring points located at Station 1 of the dam’s reservoir, immediately downstream of the dam and hydroelectric power station at the level of the damping basin, and at the Bafing-Bakoye confluence at Bafoulabe (Bafing side), the biological parameter (ichthyological fauna) is characterized by ichthyological inventories of landings in the various fishing camps around the reservoir and at the Mahina market (Bafing side). The study assesses the environmental impact of hydroelectric structures and facilities on the physico-chemical and biological quality of the water. Physical parameters such as temperature, conductivity, pH, turbidity and chemical parameters such as dissolved oxygen, nitrite, nitrate, manganese, hydrogen sulfide, ammonium, iron, silica and phosphorus are measured in order to identify the various variations existing between the different measurement points. Analysis of the values obtained shows very high similarities between the various measuring points, and most parameters comply with WHO standards, with the exception of turbidity, manganese, hydrogen sulfide and iron. These data attest to good water quality, allowing normal development of flora and fauna with a low level of degradation. Comparative analysis of the ichthyological fauna shows the existence of 34 species of fish belonging to 11 families at the fishing camps around the Manantali dam reservoir, and 37 species belonging to 12 families at Mahina on the Bafing River. At Mahina on the Bafing, the specific composition of the catches is characterized by the presence of the Claroteidae family and four species (Alestes sp., Brycinus leuciscus, Auchenoglanis occidentalis, Distichodus engycephalus) not recorded at the camps. In contrast, all the fish families recorded in the camps are present in Mahina, and only one species (Hydrocynus brevis) is absent from the Mahina landings. The difference in species richness could be explained by the upwelling of some fish from the Bakoye to the Bafing at the confluence. The Shannon diversity index of 4.07 at Mahina is higher than the 2.98 recorded at camp level, and the equitability index of 0.78 at Mahina and 0.58 at the camp level indicate average diversity and the non-dominance of one species over the others. The diversification index values of 3.09 and 3.08 at camp level and Mahina respectively show that the number of theoretical habitats is three.展开更多
The two-dimensional Quantitative Structure-Activity Relationship （2D-QSAR） models have been developed to estimate and predict the inhibitory activities of a series of HEPT analogues against HIV-1 by using quantum ch...The two-dimensional Quantitative Structure-Activity Relationship （2D-QSAR） models have been developed to estimate and predict the inhibitory activities of a series of HEPT analogues against HIV-1 by using quantum chemical parameters and physicochemical parameters. The best model of three parameters yields r = 0.908, r^2A = 0.800 and s = 0.467 based on stepwise multiple regression （SMR） method. The stability of the model has been verified by t-test, and the results show that the model has perfect robustness. The predictive power of QSAR models has been tested by Leave-One-Out （LOO） and Leave-Group（regularly random set）-Out（LGO） procedure Cross-Validation methodology. The r^2cv of 0.755 and r^2pred of 0.759 were obtained, respectively.展开更多
Understanding the hydrochemical and hydrogeological physiognomies of subsurface water in a semi-arid region is important for the effective management of water resources.This paper presents a thorough review of the hyd...Understanding the hydrochemical and hydrogeological physiognomies of subsurface water in a semi-arid region is important for the effective management of water resources.This paper presents a thorough review of the hydrogeology and hydrochemistry of the Hadejia-Yobe basin.The hydrochemical and hydrogeological configurations as reviewed indicated that the Chad Formation is the prolific aquifer in the basin.Boreholes piercing the Gundumi formation have a depth ranging from 20-85 meters.The hydrochemical composition of groundwater revealed water of excellent quality,as all the studied parameters were found to have concentrations within WHO and Nigeria’s standard for drinking water quality.However,further studies are required for further evaluation of water quality index,heavy metal pollution index,and irrigation water quality.Also,geochemical,and stable isotope analysis is required for understanding the provenance of salinity and hydrogeochemical controls on groundwater in the basin.展开更多
The indispensable role of energy in the correct functioning of economies and the current depletion of fossil fuels which are not renewable, have made the search for alternative energy sources a major point of reflecti...The indispensable role of energy in the correct functioning of economies and the current depletion of fossil fuels which are not renewable, have made the search for alternative energy sources a major point of reflection worldwide. Vegetable oils are increasingly being considered as a possible replacement for fossil fuels in countries of the south and North. In order to vulgarize the use of vegetable oil as fuel, it is essential that analytical protocols and standards are elaborated to assure the quality of oils as fuels. This work aims at developing protocols for the characterization of oilseeds and their resultant oils in a bid to ensure their quality for direct use as Biofuels or better still to serve as raw material in producing Biofuels. These protocols have the advantage of being reproducible, fast, and simple to implement compared to those used in Europe to characterize the oils (very complex and expensive, applied to petroleum products). Cotton, Jatropha curcas, white sesame, and peanut grains were acquired from the Zogona local market, Ouagadougou, and oil extraction was done at the village level. The resultant oils were characterized. Their physicochemical parameters (water content, oil content, acid index, the calorific value, density, and viscosity....) were evaluated at the Biomass Energy and Biofuels Laboratory (LBEB) of the International Institute for Water and Environmental Engineering (2iE) and the Burkinabé National Hydrocarbons Authority (SONABHY) Laboratory. The oilseed grain cakes (moisture, ash rate, rate of volatile matter, and oil content...) were also analysed.展开更多
Despite the abundant water resources available in Lebanon, it still faces a water shortage. Pollution is one of the main stresses on Lebanon’s water resources. This study was carried out in Nabaa El Tasseh Spring, th...Despite the abundant water resources available in Lebanon, it still faces a water shortage. Pollution is one of the main stresses on Lebanon’s water resources. This study was carried out in Nabaa El Tasseh Spring, the main water supply source in the Nabatiyeh Region. The aim of this study is to assess water quality of the spring of Nabaa El Tasseh during winter and spring seasons to determine the Water Quality Index (WQI). At the Environmental Laboratory of Lebanese University, Faculty of Agronomy, water was tested physiochemical parameters including temperature, hydrogen potential (pH), electrical conductivity (EC), total dissolved solids (TDS), anions (NO3−, Cl−, SO42−), and cations (Mg2+, Ca2+, Na+, K+ and Fe2+). The majority of the physical and chemical parameters under investigation fell below the international and Lebanese norms, including WHO recommendations. Additionally, fecal Streptococcus, total coliforms, and fecal coliforms were determined using microbiological testing. Due to its proximity to agricultural activities, the Nabaa El Tasseh Spring water was contaminated by total coliforms. Fecal Coliforms and Fecal Streptococcus, on the other hand, are a sign of animal or human sewage contamination in groundwater. WQI was calculated using the Weighted Arithmetic Index approach. This study has shown that water quality in Nabaa El Tasseh Spring was not acceptable for consumption without treatment in February 2019 with WQI values equal to 88.608, but it became 31.51 acceptable during April and 18.22 in December 2022. An index is a useful tool for conveying water quality information to the public and legislative decision-makers. Although the WQI is excellent in the spring, there is microbiological pollution, thus water treatment is required. The results indicated that Principal Component Analysis (PCA) could clearly explain the pollution trends in the spring over several months. The study’s findings indicate that before the water of Nabaa El Tasseh Spring can be used for drinking or residential purposes, it must first undergo extensive treatment.展开更多
The physical and chemical properties of the air-dried residual coal after soaking in the goaf will change,resulting in an increase in its spontaneous combustion tendency.This study aimed to look into the features and ...The physical and chemical properties of the air-dried residual coal after soaking in the goaf will change,resulting in an increase in its spontaneous combustion tendency.This study aimed to look into the features and mechanism of soaked-dried coal's spontaneous combustion.Five samples of coal were dried to various degrees,and the weight loss features during thermal processing were examined.Based on this,the pore structure and chemical structure characteristics of the coal samples with the highest tendency to spontaneous combustion were quantitatively examined,and the mechanism by which soaking-drying afected the spontaneous combustion heating process of the remaining coal in goaf was investigated in turn.The results show that T1 decreases with the increase of drying time,T2–T6 shows a fuctuating change,and the ignition activation energy of 36-S-Coal is smaller than that of other coal samples.The pore type of 36-S-Coal changes from a oneend closed impermeable pore to an open pore,and the pore group area is large.During the 36 h drying process,the internal channels of the coal were dredged,and a large number of gravels and minerals were precipitated from the pores with the air fow.A large number of gravels were around the pores to form a surface structure that was easy to adsorb various gases.Furthermore,infrared spectroscopy was used to analyze the two coal samples.It was found that soaking and drying did not change the functional group types of coal samples,but the fatty chain degree of 36-S-Coal was reduced to 1.56.It shows that the aliphatic chain structure of coal is changed after 36 h of drying after 30 days of soaking,which leads to the continuous shedding of aliphatic chain branches of residual coal,and the skeleton of coal is looser,which makes the low-temperature oxidation reaction of 36-S-Coal easier.Based on the above results,the coal-oxygen composite mechanism of water-immerseddried coal is obtained,and it is considered that the key to the spontaneous combustion oxidation process of coal is to provide oxygen atoms and accelerate the formation of peroxides.展开更多
The results of an expert system of lanthanide intermetallic compounds using artificial neural networks and chemical bond parameter method were reported. Two pattern recognition neural models, one for prediction of the...The results of an expert system of lanthanide intermetallic compounds using artificial neural networks and chemical bond parameter method were reported. Two pattern recognition neural models, one for prediction of the occurrence of 1 : 1 lanthanide intermetallic compounds with CsClstructure and the other for prediction of congruent or incongruent melting types, were developed. Four regression neural models were also developed for prediction of melting point of these compounds. In order to get rid of overfitting, cross-vahdation method was used for the neural models. And satisfactory results were obtained in all of the neural models in this paper.展开更多
The unsteady stagnation-point flow of a hybrid nanofluid over a stretching/shrinking sheet embedded in a porous medium with mass transpiration and chemical reactions is considered.The momentum and mass transfer proble...The unsteady stagnation-point flow of a hybrid nanofluid over a stretching/shrinking sheet embedded in a porous medium with mass transpiration and chemical reactions is considered.The momentum and mass transfer problems are combined to form a system of partial differential equations,which is converted into a set of ordinary differential equations via similarity transformation.These ordinary differential equations are solved analytically to obtain the solution for velocity and concentration profiles in exponential and hypergeometric forms,respectively.The concentration profile is obtained for four different cases namely constant wall concentration,uniform mass flux,general power law wall con-centration and general power law mass flux.The effect of different physical parameters such as Darcy number Da^(1-1),mass transpiration parameter V_(C),stretching/shrinking parameter (d),chemical reaction parameter(β)and Schmidt number (Sc)on velocity and concentration profile is examined.Results show that,the axial velocity will decreases as the shrinking sheet parameter increases,regardless of whether the suction or injection case is examined.The concentration decreases with an increase in the shrinking sheet parameter and the chemical reaction rate parameter.展开更多
Nineteen preschisanartane-type schinortriterpenoids(SNTs),among which eleven ones were previously undescribed,were isolated from two Schisandra species,S.sphaerandra and S.rubriflora.Their structures were determined u...Nineteen preschisanartane-type schinortriterpenoids(SNTs),among which eleven ones were previously undescribed,were isolated from two Schisandra species,S.sphaerandra and S.rubriflora.Their structures were determined using 1 D and 2 D NMR spectroscopic analyses,NMR data comparison,quantum chemical calculation of NMR parameters,electronic circular dichroism(ECD),X-ray single crystal diffraction,and chemical derivation.Furthermore,structural re-examination of a few previously reported preschisanartane-type SNTs led to the structural revision of preschisanartanin J.Besides,it is suggested that the reported structures of arisanlactone D and schilancidilactone W should be re-checked.Finally,a few isolated SNTs were found to possess neurite outgrowthpromoting activities,and protective activities against neural injuries.展开更多
The partial replacement of durum wheat semolina with local flours such as soybeans and yam reduces the dependence of durum wheat semolina for the production of pasta</span><span style="font-family:Verdan...The partial replacement of durum wheat semolina with local flours such as soybeans and yam reduces the dependence of durum wheat semolina for the production of pasta</span><span style="font-family:Verdana;">.</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">The</span><span style="font-family:""><span style="font-family:Verdana;"> main objective of this study is to develop yam flour (A) from Dioscorea alata in the manufacture of pasta made with durum wheat semolina (B) and soy flour (C) (raw materials). The methodology adopted consists first of all in the characterization of yam, soybean </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> durum wheat semolina. An experimental design was developed to bring out the balanced mixing plan in well-defined proportions with ten (10) tests. Chemical and functional analyzes were carried out on the pastes obtained from these formulations. The functional properties allowed us to determine the optimal mixing plan using a mathematical model. The sensory properties of the optimal compound dough were estimated in comparison with the control doughs. The results on the chemical properties of raw materials A, B </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> C obtained on the water content vary from 10.29% to 12.29%;those of ashes vary from 0.91% to 5.74% and those of proteins vary from 3.24% to 20.17%. The results of the chemical and functional parameters of compound pasta gave very diverse values. We find that the water content, the ash content, the protein content </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> the acidity rate of the series of 10 tests are respectively from 6.60% to 14.97%, from 0.97% to 1.67%, from 7.15% to 12.10% </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> from 1.35% to 3.60%. Regarding the optimal cooking time for this series of 10 tests, it varies from 15 min to 20 min with a swelling index which is between 59.70% and 107.12%. Statistical tests (test F) from the different models indicate that the main regression effects are not significant with a p-value probability greater than 0.05. The models obtained were significant with a good value for the coefficient of determination R</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">. The sensory test approved that optimal compound pasta has good overall acceptability compared to 100% durum wheat pasta. The 20.40% yam flour mixture (102.020 g);55.19% of durum wheat semolina (275.982 g) and 24.39% of soy flour (121.998 g) has good potential in the preparation of compound pasta.展开更多
We present the results of studies conducted on the assessment of groundwater quality observed on several water samples taken from water supply sources in the Pul-e-Charkhi region,which is located near the eastern part...We present the results of studies conducted on the assessment of groundwater quality observed on several water samples taken from water supply sources in the Pul-e-Charkhi region,which is located near the eastern part of Kabul and has seen steady growth in population after the U.S.completed its withdrawal from Afghanistan on 30 August 2021.The water in the basin serves as the main source of water supply and it consists of water discharge from nearby local industries,automobile repair and wash,Osman House,Gradation Place,International Standards Region,and many other regional sources that create a mix of contaminants in discharge to the basin.We collected several samples from each groundwater source for this investigation and transported them carefully to the research laboratory,maintaining the integrity of the samples.The main objective of this study is to assess groundwater quality for the determination of contaminants in groundwater to see what limitations it may pose for recycling and reuse.Such a study is necessary since the region requires persistent sources of water due to a steady increase in population and an associated shortage of water supply due to arid conditions.Furthermore,there is unavailability of similar data since the region served to support military operations since 2001.The samples were analyzed for temperature,electro-conductivity,dissolved oxygen,total dissolved solids,salinity,pH,color,turbidity,hardness,chemicals,and heavy metals.The results obtained suggest that the parameters can be used efficiently to design filtration strategies based on region-specific contamination for the specific catchments located in and around the Kabul Basin.An effort to add additional characterization techniques is described to detect micro/nano plastics and new and emerging contaminants.The efforts reported here are consistent with the 2030 agenda for Sustainable Development Goals.展开更多
Optical fiber sensors(OFSs)have attracted more and more attention in the field of in-situ ocean observation because of their advantages of the small size,light weight,low cost,and intrinsic immunity to electromagnetic...Optical fiber sensors(OFSs)have attracted more and more attention in the field of in-situ ocean observation because of their advantages of the small size,light weight,low cost,and intrinsic immunity to electromagnetic interference.Here,we comprehensively reviewed the development of various advanced physical and chemical OFSs for in-situ measurement of ocean key parameters,including temperature,salinity,pressure,acoustics,flow velocity and turbulence,potential of hydrogen(pH),heavy metal ions,nitrates,and gases.Moreover,the performances of different kinds of OFSs and their practical sea trial reports for in-situ measurement in the marine environment are provided.As we discussed,the field of OFS is rapidly evolving and is poised to make essential breakthroughs in marine monitoring,leading to better utility of marine resources.展开更多
In this study,heat and mass transfer in a viscous fluid which is squeezed between parallel plates Is investigated numerically using the fouith-order Runge-Kutta method.The numerical investigation is carried out for di...In this study,heat and mass transfer in a viscous fluid which is squeezed between parallel plates Is investigated numerically using the fouith-order Runge-Kutta method.The numerical investigation is carried out for different governing parameters namely;the squeeze number,Prandtl number,Eckert number,Schmidt number and the chemical reaction parameter.Results show that Nusselt number has direct relationship with Prandtl number and Eckert number but it has reverse relationship with the squeeze number.Also it can be found that Sherwood number increases as Schmidt number and chemical reaction parameter increases but it decreases with increases of the squeeze number.展开更多
文摘Groundwater is critical for supplying drinking water to billions of people worldwide.However,their excessive permeability makes them more vulnerable to retaining and spreading contamination.Assessing groundwater vulnerability is crucial for sustainable management,as it aids in reducing the risks associated with contamination of this valuable resource.As a result,the primary aim of this paper is to critically review and synthesize recent advances in groundwater vulnerability and risk assessment using hydrogeochemical parameters.A summary of groundwater contamination,sources,and consequences is presented.Information on hydrogeochemical factors and groundwater vulnerability is summarised.A review of the most commonly used groundwater vulnerability assessment methods is covered.It also covers the assessment of groundwater vulnerability using hydrogeochemical parameters and statistical approaches.Furthermore,these approaches are supported by global case studies.Finally,the limitations,conclusion,and future recommendations are presented.It can be concluded that integrating hydrogeochemical parameters with groundwater vulnerability models is an effective method for assessing the risk of groundwater contamination and developing management plans.Researchers in the fields of health,earth sciences,environmental studies,and water sciences will find this comprehensive review to be a valuable reference,as it offers an in-depth understanding of the current knowledge on the integration of hydrogeochemical parameters in groundwater vulnerability and risk assessment studies.
文摘This study was conducted to evaluate four different parental oriental varieties with their F1 crosses to estimate inheritance of some morphological traits, such as plant hight, number of leaves, total dry weigh and chemical compounds, especially nicotine and sugars during sun-curing period. The oriental varieties Kozarsko 541, Plovdiv 50 and Krumovgrad 17 from Bulgaria and Basma Xanthi 101 from Greece and their respective crosses with Basma Xanthi 101 were studied. The study was set up in 2014 and 2015 in experimental field of the Tobacco and Tobacco Products Institute, Plovdiv, using randomized block design with four replications. Common agricultural practices were applied during the growing season. The result indicated that in hybrid combination with parental varieties Kozarsko 541 and Plovdiv 50, except total dry weight, additive gene effects are important for traits height of plant and number of leaves. Height of plant and number of leaves are inherited partially dominant to parent with higher value and total dry weight inheritance was over dominant. In hybrid combination Krumovgrad 17 x Basma Xanthi 101, inheritance of the plant height and leaves number were over dominant type. Total dry weight is inherited partially dominant. In a word, prevailing mode for inheritance of plant hight and total dry weight was the over dominance and for number of leaves it was partial dominance. In sun-curing with yellowing stage, nicotine decreased and sugars increased in all tested varieties with a highest percentage in variety Kozarsko 541 （nicotine） and Krumovgrad 17 （sugars）.
文摘Quantum chemical parameters of 10 amino acids with D- and L-configurations were firstly calculated with semi-empirical AM1 method. Furthermore, the relationship between molecular structures of D-, L-amino acids and their sweetness were observed. The results show that upon different configurations of amino acids, the sweetness is relative with their formation heat, dipole moment, energy gap of frontier orbital and other parameters. The formation heats of the same amino acids possessing D- and L-configurations are different except glycine. The algebraic value of D-amino acid is generally larger than that of corresponding L-configuration with only one except of tyrosine. The dipole moment of D-amino acid is generally larger than that of corresponding L-amino acid except tyrosine and lysine. The lowest unoccupied orbital energy （ELUMO） of D-amino acid is higher than that of corresponding L-configuration except phenylalanine. △E of D-amino acid is larger than that of L-amino acid except histidine, phenylalanine and lysine. The larger gap will have advantage for its matching with frontier orbital energy of human protein acceptor, which strengthens the interaction between D-amino acid and sweet taste acceptor. Besides, the changing rules of these parameters are generally identical.
文摘Objective: The study aims to investigate some physical and technological parameters of varieties of maize collected from the most representative areas of maize production in the southern part of Benin, and mainly used by the populations of those areas. Method: The chemical composition, physical and technological characteristics of the grains were determined using standard methods. Results: The results showed that the weight of 1000 grains ranges from 158.01 to 305.12 g, the length from 0.79 to 1.81 cm, the average width from 0.74 to 1.51 cm, thickness from 0.36 to 0.85 cm and density from 1.07 to 1.25. Regarding the technological parameters, the hardness of the grains before and after cooking was between 16.78 and 47.20 kgf, and 0.23 and 0.71 kgf respectively, while the cooking time varies from 71.00 and 158.33 mn. There was a positive and significant correlation (r = 0.405;p < 0.026) between the hardness after cooking and the weight of 1000 grains, between the hardness after cooking and grain width (r = 0.460;p < 0.011). A positive and highly significant correlation (r = 0.527, p < 0.003) was also observed between the hardness after cooking and the grain length, between the hardness after cooking and the thickness of grain (r = 0.476, p < 0.008), and between the grain density and the weight of 1000 grains (r = 0.481, p < 0.007). A positive and highly significant correlation (r = 0.923, p < 0.000) was also observed between maize grain length and width, and between grain length and grain thickness (r = 0.764, p < 0.000) and between the width and thickness (r = 0.764, p < 0.000). On the other hand, a significant negative correlation (r = -0.394, p < 0.031) was found between the hardness before cooking and the thickness and between the hardness before cooking and sphericity index (r = -0465*, p Conclusion: Through its chemical and technological characteristics the maize constitutes an important raw material for many culinary recipes in West African region.
文摘Chemical bond parameters, that is, bond covalency, bond valence, macroscopic linear susceptibility, and oxidation states of elements in Sr3MRhO6(M-Sm, Eu, Tb, Dy, Ho, Er, Yb) have been calculated. The results indicate that the bond covalency of M-O decreases sharply with the decrease of ionic radius of M3+ from Sm to Yb, while no obvious trend has been found for Rh-O and Sr-O bonds. The global instability index indicates that the crystal structures of Sr3MrhO6(M=Sm, Eu, Tb, Dy, Ho) have strained bonds.
文摘The comparative study is designed to monitor the physico-chemical and biological quality of the water upstream and downstream of the Manantali hydroelectric dam. The physico-chemical parameters are sampled at 3 measuring points located at Station 1 of the dam’s reservoir, immediately downstream of the dam and hydroelectric power station at the level of the damping basin, and at the Bafing-Bakoye confluence at Bafoulabe (Bafing side), the biological parameter (ichthyological fauna) is characterized by ichthyological inventories of landings in the various fishing camps around the reservoir and at the Mahina market (Bafing side). The study assesses the environmental impact of hydroelectric structures and facilities on the physico-chemical and biological quality of the water. Physical parameters such as temperature, conductivity, pH, turbidity and chemical parameters such as dissolved oxygen, nitrite, nitrate, manganese, hydrogen sulfide, ammonium, iron, silica and phosphorus are measured in order to identify the various variations existing between the different measurement points. Analysis of the values obtained shows very high similarities between the various measuring points, and most parameters comply with WHO standards, with the exception of turbidity, manganese, hydrogen sulfide and iron. These data attest to good water quality, allowing normal development of flora and fauna with a low level of degradation. Comparative analysis of the ichthyological fauna shows the existence of 34 species of fish belonging to 11 families at the fishing camps around the Manantali dam reservoir, and 37 species belonging to 12 families at Mahina on the Bafing River. At Mahina on the Bafing, the specific composition of the catches is characterized by the presence of the Claroteidae family and four species (Alestes sp., Brycinus leuciscus, Auchenoglanis occidentalis, Distichodus engycephalus) not recorded at the camps. In contrast, all the fish families recorded in the camps are present in Mahina, and only one species (Hydrocynus brevis) is absent from the Mahina landings. The difference in species richness could be explained by the upwelling of some fish from the Bakoye to the Bafing at the confluence. The Shannon diversity index of 4.07 at Mahina is higher than the 2.98 recorded at camp level, and the equitability index of 0.78 at Mahina and 0.58 at the camp level indicate average diversity and the non-dominance of one species over the others. The diversification index values of 3.09 and 3.08 at camp level and Mahina respectively show that the number of theoretical habitats is three.
文摘The two-dimensional Quantitative Structure-Activity Relationship （2D-QSAR） models have been developed to estimate and predict the inhibitory activities of a series of HEPT analogues against HIV-1 by using quantum chemical parameters and physicochemical parameters. The best model of three parameters yields r = 0.908, r^2A = 0.800 and s = 0.467 based on stepwise multiple regression （SMR） method. The stability of the model has been verified by t-test, and the results show that the model has perfect robustness. The predictive power of QSAR models has been tested by Leave-One-Out （LOO） and Leave-Group（regularly random set）-Out（LGO） procedure Cross-Validation methodology. The r^2cv of 0.755 and r^2pred of 0.759 were obtained, respectively.
文摘Understanding the hydrochemical and hydrogeological physiognomies of subsurface water in a semi-arid region is important for the effective management of water resources.This paper presents a thorough review of the hydrogeology and hydrochemistry of the Hadejia-Yobe basin.The hydrochemical and hydrogeological configurations as reviewed indicated that the Chad Formation is the prolific aquifer in the basin.Boreholes piercing the Gundumi formation have a depth ranging from 20-85 meters.The hydrochemical composition of groundwater revealed water of excellent quality,as all the studied parameters were found to have concentrations within WHO and Nigeria’s standard for drinking water quality.However,further studies are required for further evaluation of water quality index,heavy metal pollution index,and irrigation water quality.Also,geochemical,and stable isotope analysis is required for understanding the provenance of salinity and hydrogeochemical controls on groundwater in the basin.
文摘The indispensable role of energy in the correct functioning of economies and the current depletion of fossil fuels which are not renewable, have made the search for alternative energy sources a major point of reflection worldwide. Vegetable oils are increasingly being considered as a possible replacement for fossil fuels in countries of the south and North. In order to vulgarize the use of vegetable oil as fuel, it is essential that analytical protocols and standards are elaborated to assure the quality of oils as fuels. This work aims at developing protocols for the characterization of oilseeds and their resultant oils in a bid to ensure their quality for direct use as Biofuels or better still to serve as raw material in producing Biofuels. These protocols have the advantage of being reproducible, fast, and simple to implement compared to those used in Europe to characterize the oils (very complex and expensive, applied to petroleum products). Cotton, Jatropha curcas, white sesame, and peanut grains were acquired from the Zogona local market, Ouagadougou, and oil extraction was done at the village level. The resultant oils were characterized. Their physicochemical parameters (water content, oil content, acid index, the calorific value, density, and viscosity....) were evaluated at the Biomass Energy and Biofuels Laboratory (LBEB) of the International Institute for Water and Environmental Engineering (2iE) and the Burkinabé National Hydrocarbons Authority (SONABHY) Laboratory. The oilseed grain cakes (moisture, ash rate, rate of volatile matter, and oil content...) were also analysed.
文摘Despite the abundant water resources available in Lebanon, it still faces a water shortage. Pollution is one of the main stresses on Lebanon’s water resources. This study was carried out in Nabaa El Tasseh Spring, the main water supply source in the Nabatiyeh Region. The aim of this study is to assess water quality of the spring of Nabaa El Tasseh during winter and spring seasons to determine the Water Quality Index (WQI). At the Environmental Laboratory of Lebanese University, Faculty of Agronomy, water was tested physiochemical parameters including temperature, hydrogen potential (pH), electrical conductivity (EC), total dissolved solids (TDS), anions (NO3−, Cl−, SO42−), and cations (Mg2+, Ca2+, Na+, K+ and Fe2+). The majority of the physical and chemical parameters under investigation fell below the international and Lebanese norms, including WHO recommendations. Additionally, fecal Streptococcus, total coliforms, and fecal coliforms were determined using microbiological testing. Due to its proximity to agricultural activities, the Nabaa El Tasseh Spring water was contaminated by total coliforms. Fecal Coliforms and Fecal Streptococcus, on the other hand, are a sign of animal or human sewage contamination in groundwater. WQI was calculated using the Weighted Arithmetic Index approach. This study has shown that water quality in Nabaa El Tasseh Spring was not acceptable for consumption without treatment in February 2019 with WQI values equal to 88.608, but it became 31.51 acceptable during April and 18.22 in December 2022. An index is a useful tool for conveying water quality information to the public and legislative decision-makers. Although the WQI is excellent in the spring, there is microbiological pollution, thus water treatment is required. The results indicated that Principal Component Analysis (PCA) could clearly explain the pollution trends in the spring over several months. The study’s findings indicate that before the water of Nabaa El Tasseh Spring can be used for drinking or residential purposes, it must first undergo extensive treatment.
基金supported by the fnancial support of the General Projects of National Natural Science Foundation of China(52074156).
文摘The physical and chemical properties of the air-dried residual coal after soaking in the goaf will change,resulting in an increase in its spontaneous combustion tendency.This study aimed to look into the features and mechanism of soaked-dried coal's spontaneous combustion.Five samples of coal were dried to various degrees,and the weight loss features during thermal processing were examined.Based on this,the pore structure and chemical structure characteristics of the coal samples with the highest tendency to spontaneous combustion were quantitatively examined,and the mechanism by which soaking-drying afected the spontaneous combustion heating process of the remaining coal in goaf was investigated in turn.The results show that T1 decreases with the increase of drying time,T2–T6 shows a fuctuating change,and the ignition activation energy of 36-S-Coal is smaller than that of other coal samples.The pore type of 36-S-Coal changes from a oneend closed impermeable pore to an open pore,and the pore group area is large.During the 36 h drying process,the internal channels of the coal were dredged,and a large number of gravels and minerals were precipitated from the pores with the air fow.A large number of gravels were around the pores to form a surface structure that was easy to adsorb various gases.Furthermore,infrared spectroscopy was used to analyze the two coal samples.It was found that soaking and drying did not change the functional group types of coal samples,but the fatty chain degree of 36-S-Coal was reduced to 1.56.It shows that the aliphatic chain structure of coal is changed after 36 h of drying after 30 days of soaking,which leads to the continuous shedding of aliphatic chain branches of residual coal,and the skeleton of coal is looser,which makes the low-temperature oxidation reaction of 36-S-Coal easier.Based on the above results,the coal-oxygen composite mechanism of water-immerseddried coal is obtained,and it is considered that the key to the spontaneous combustion oxidation process of coal is to provide oxygen atoms and accelerate the formation of peroxides.
文摘The results of an expert system of lanthanide intermetallic compounds using artificial neural networks and chemical bond parameter method were reported. Two pattern recognition neural models, one for prediction of the occurrence of 1 : 1 lanthanide intermetallic compounds with CsClstructure and the other for prediction of congruent or incongruent melting types, were developed. Four regression neural models were also developed for prediction of melting point of these compounds. In order to get rid of overfitting, cross-vahdation method was used for the neural models. And satisfactory results were obtained in all of the neural models in this paper.
文摘The unsteady stagnation-point flow of a hybrid nanofluid over a stretching/shrinking sheet embedded in a porous medium with mass transpiration and chemical reactions is considered.The momentum and mass transfer problems are combined to form a system of partial differential equations,which is converted into a set of ordinary differential equations via similarity transformation.These ordinary differential equations are solved analytically to obtain the solution for velocity and concentration profiles in exponential and hypergeometric forms,respectively.The concentration profile is obtained for four different cases namely constant wall concentration,uniform mass flux,general power law wall con-centration and general power law mass flux.The effect of different physical parameters such as Darcy number Da^(1-1),mass transpiration parameter V_(C),stretching/shrinking parameter (d),chemical reaction parameter(β)and Schmidt number (Sc)on velocity and concentration profile is examined.Results show that,the axial velocity will decreases as the shrinking sheet parameter increases,regardless of whether the suction or injection case is examined.The concentration decreases with an increase in the shrinking sheet parameter and the chemical reaction rate parameter.
基金supported by the National Natural Science Foundation of China(No.81903520)the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(No.2019QZKK0502)
文摘Nineteen preschisanartane-type schinortriterpenoids(SNTs),among which eleven ones were previously undescribed,were isolated from two Schisandra species,S.sphaerandra and S.rubriflora.Their structures were determined using 1 D and 2 D NMR spectroscopic analyses,NMR data comparison,quantum chemical calculation of NMR parameters,electronic circular dichroism(ECD),X-ray single crystal diffraction,and chemical derivation.Furthermore,structural re-examination of a few previously reported preschisanartane-type SNTs led to the structural revision of preschisanartanin J.Besides,it is suggested that the reported structures of arisanlactone D and schilancidilactone W should be re-checked.Finally,a few isolated SNTs were found to possess neurite outgrowthpromoting activities,and protective activities against neural injuries.
文摘The partial replacement of durum wheat semolina with local flours such as soybeans and yam reduces the dependence of durum wheat semolina for the production of pasta</span><span style="font-family:Verdana;">.</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">The</span><span style="font-family:""><span style="font-family:Verdana;"> main objective of this study is to develop yam flour (A) from Dioscorea alata in the manufacture of pasta made with durum wheat semolina (B) and soy flour (C) (raw materials). The methodology adopted consists first of all in the characterization of yam, soybean </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> durum wheat semolina. An experimental design was developed to bring out the balanced mixing plan in well-defined proportions with ten (10) tests. Chemical and functional analyzes were carried out on the pastes obtained from these formulations. The functional properties allowed us to determine the optimal mixing plan using a mathematical model. The sensory properties of the optimal compound dough were estimated in comparison with the control doughs. The results on the chemical properties of raw materials A, B </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> C obtained on the water content vary from 10.29% to 12.29%;those of ashes vary from 0.91% to 5.74% and those of proteins vary from 3.24% to 20.17%. The results of the chemical and functional parameters of compound pasta gave very diverse values. We find that the water content, the ash content, the protein content </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> the acidity rate of the series of 10 tests are respectively from 6.60% to 14.97%, from 0.97% to 1.67%, from 7.15% to 12.10% </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> from 1.35% to 3.60%. Regarding the optimal cooking time for this series of 10 tests, it varies from 15 min to 20 min with a swelling index which is between 59.70% and 107.12%. Statistical tests (test F) from the different models indicate that the main regression effects are not significant with a p-value probability greater than 0.05. The models obtained were significant with a good value for the coefficient of determination R</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">. The sensory test approved that optimal compound pasta has good overall acceptability compared to 100% durum wheat pasta. The 20.40% yam flour mixture (102.020 g);55.19% of durum wheat semolina (275.982 g) and 24.39% of soy flour (121.998 g) has good potential in the preparation of compound pasta.
文摘We present the results of studies conducted on the assessment of groundwater quality observed on several water samples taken from water supply sources in the Pul-e-Charkhi region,which is located near the eastern part of Kabul and has seen steady growth in population after the U.S.completed its withdrawal from Afghanistan on 30 August 2021.The water in the basin serves as the main source of water supply and it consists of water discharge from nearby local industries,automobile repair and wash,Osman House,Gradation Place,International Standards Region,and many other regional sources that create a mix of contaminants in discharge to the basin.We collected several samples from each groundwater source for this investigation and transported them carefully to the research laboratory,maintaining the integrity of the samples.The main objective of this study is to assess groundwater quality for the determination of contaminants in groundwater to see what limitations it may pose for recycling and reuse.Such a study is necessary since the region requires persistent sources of water due to a steady increase in population and an associated shortage of water supply due to arid conditions.Furthermore,there is unavailability of similar data since the region served to support military operations since 2001.The samples were analyzed for temperature,electro-conductivity,dissolved oxygen,total dissolved solids,salinity,pH,color,turbidity,hardness,chemicals,and heavy metals.The results obtained suggest that the parameters can be used efficiently to design filtration strategies based on region-specific contamination for the specific catchments located in and around the Kabul Basin.An effort to add additional characterization techniques is described to detect micro/nano plastics and new and emerging contaminants.The efforts reported here are consistent with the 2030 agenda for Sustainable Development Goals.
基金the National Natural Science Foundation of China(Grant Nos.62375248 and 62035006)Shandong Provincial Natural Science Foundation,China(Grant Nos.ZR2021MF123 and ZR2023MD067)+1 种基金Independent Research Project for Graduate Students of Ocean University of China(Grant No.202261011)Program of Marine Economy Development Special Fund under Department of Natural Resources of Guangdong Province,China[Grant No.GDNRC[2023]23].
文摘Optical fiber sensors(OFSs)have attracted more and more attention in the field of in-situ ocean observation because of their advantages of the small size,light weight,low cost,and intrinsic immunity to electromagnetic interference.Here,we comprehensively reviewed the development of various advanced physical and chemical OFSs for in-situ measurement of ocean key parameters,including temperature,salinity,pressure,acoustics,flow velocity and turbulence,potential of hydrogen(pH),heavy metal ions,nitrates,and gases.Moreover,the performances of different kinds of OFSs and their practical sea trial reports for in-situ measurement in the marine environment are provided.As we discussed,the field of OFS is rapidly evolving and is poised to make essential breakthroughs in marine monitoring,leading to better utility of marine resources.
文摘In this study,heat and mass transfer in a viscous fluid which is squeezed between parallel plates Is investigated numerically using the fouith-order Runge-Kutta method.The numerical investigation is carried out for different governing parameters namely;the squeeze number,Prandtl number,Eckert number,Schmidt number and the chemical reaction parameter.Results show that Nusselt number has direct relationship with Prandtl number and Eckert number but it has reverse relationship with the squeeze number.Also it can be found that Sherwood number increases as Schmidt number and chemical reaction parameter increases but it decreases with increases of the squeeze number.
