Crude oil spills have inflicted extensive disruption upon the Niger Delta ecosystem, resulting in crop loss and severe environmental damage. Such spills exacerbate heavy metal concentration within soil due to the pres...Crude oil spills have inflicted extensive disruption upon the Niger Delta ecosystem, resulting in crop loss and severe environmental damage. Such spills exacerbate heavy metal concentration within soil due to the presence of metallic ions. The Okpare-Olomu community has borne the brunt of crude oil pollution from illicit bunkering, sabotage, and equipment malfunction. This study targets an evaluation of ecological hazards linked to heavy metals (HMs) in crude oil impacted agriculturally soils within Okpare-Olomu in Ughelli South LGA of Delta State. In this study, 24 topsoil samples were obtained from areas affected by crude oil pollution;the heavy metal content was evaluated through atomic absorption spectrometry. The concentration ranges for HMs (mg/kg) in soil were: 24.1 - 23,174 (Cu);0.54 - 37.1 (Cd);9.05 - 54 (Cr);12 - 174 (Ni);18.5 - 8611 (Pb);and 148 - 9078 (Zn) at a soil depth of 0 - 15 cm. Notably, metal concentrations were recorded to be above permissible World Health Organization limits. Predominantly, Zn and Pb recorded higher heavy metal concentration when compared to other heavy metals analysed, notably at sampling points PT7 through PT24. Zinc and Pb contamination exhibited highly significant contamination factors, and contamination severity was evidenced across all sample points, signifying a grave risk level. Pollution load indices indicated pervasive extreme pollution levels. Geoaccumulation indices signaled moderate to strong pollution, mainly by Pb and Zn. Ecological risk assessments revealed variable levels of heavy metal contamination, from low to very high, with potential ecological risk reflecting markedly elevated levels. This study underscores the imperative for soil remediation to rectify ecological imbalances in agriculturally affected soil constituents.展开更多
Heavy metal contaminated water sources pose serious health risks for humans,animals,and plants.Exposure to and ingestion of heavy metals have been associated to liver,kidney,and brain function.Objective:The aim of thi...Heavy metal contaminated water sources pose serious health risks for humans,animals,and plants.Exposure to and ingestion of heavy metals have been associated to liver,kidney,and brain function.Objective:The aim of this research is to comparatively examine the metal removal efficacy of three solid bidentate chemicals and four plant materials.Study Design&Methods:Standard solutions of zinc(II)and lead(II)ions with concentrations of 1,000 ppm were respectively treated with OA(Oxalic Acid),dibasic bidentate ligands(sodium hydrogen phosphate and sodium carbonate).Then,the solutions were placed on a shaker for 15 h,centrifuged,and the supernatant was analyzed using ICP-AES(Inductively Coupled Plasma-Atomic Emission Spectrometry).Results:All the solid bidentate adsorbents were very effective in removing zinc and lead(>90%).However,more lead than zinc was removed across all adsorbents except for lemon where equal percent of zinc and lead(49%)were removed.OA and Na2HPO4 removed about equal amount of lead(>99%).The plant materials(SP(Spinach),bell pepper and GBP(Green Bell Pepper)),respectively and preferentially removed more lead(98.9%,98.3%,81.5%)than zinc(91.7%,46%,46%).Conclusion:Although plant materials have gained attraction for the remediation of heavy metal,however,some bidentate chemical ligands such as OA,sodium carbonate and sodium hydrogen phosphates are even more effective in removing these metals from contaminated water.Furthermore,heavier metals are preferentially removed than lighter metals.展开更多
Recognition of pulse repetition interval(PRI)modulation is a fundamental task in the interpretation of radar intentions.However,the existing PRI modulation recognition methods mainly focus on single-label classificati...Recognition of pulse repetition interval(PRI)modulation is a fundamental task in the interpretation of radar intentions.However,the existing PRI modulation recognition methods mainly focus on single-label classification of PRI sequences.The prerequisite for the effectiveness of these methods is that the PRI sequences are perfectly divided according to different modulation types before identification,while the actual situation is that radar pulses reach the receiver continuously,and there is no completely reliable method to achieve this division in the case of non-cooperative reception.Based on the above actual needs,this paper implements an algorithm based on the recurrence plot technique and the multi-target detection model,which does not need to divide the PRI sequence in advance.Compared with the sliding window method,it can more effectively realize the recognition of the dynamically varying PRI mo dulation.展开更多
Statistical comparison of two remediation methods: Remedial nutrient solution and enhanced natural attenuation were analyzed in terms of TPH of different soil samples collected from Khana Local Government Area of Rive...Statistical comparison of two remediation methods: Remedial nutrient solution and enhanced natural attenuation were analyzed in terms of TPH of different soil samples collected from Khana Local Government Area of Rivers State, Nigeria at different locations and placed inside sample bottles labelled A to D and replicated into two, one for each of the above treatment technique. The TPH of the soil was determined using GC analyzer after solvent extraction was carried out using hexane/dichloromethane mixture. Three batches of treatment were performed on the samples at every interval of eight weeks for a duration of six months. The result obtained was analyzed using a two-way ANOVA factorial experimental design to test the significance of the various sources of variation. From the result obtained, source of variation for sample and interactions were non-significantly different from each other which means that irrespective of the number of samples analyzed or the combination of both samples and batches of treatment, they will still not be significantly different from each other. The source of variation for batch and replications were significantly different from each other and this means that irrespective of the batches of treatment applied or the number of replications (methods of treatment used), they will always be significantly different from each other. The individual comparison of each sample showed that the efficiency of the Remedial Nutrient Solution method was better than Enhanced Natural Attenuation method.展开更多
Iron-based amorphous crystalline powder Fe_(78)Si_(9)B_(13)^(AP)is used as a permeability reaction barrier(PRB)combined with an electrokinetic method(EK-PRB)to study the removal rate of Cu in contaminated soil.After t...Iron-based amorphous crystalline powder Fe_(78)Si_(9)B_(13)^(AP)is used as a permeability reaction barrier(PRB)combined with an electrokinetic method(EK-PRB)to study the removal rate of Cu in contaminated soil.After treating Cucontaminated soil for 5 days under different voltage gradients and soil water content,the soil pH is between 3.1 and 7.2.The increase of voltage gradient and soil water content can effectively promote the movement of Cu^(2+) to the cathode.The voltage gradient is 3 V/cm,and the water content of 40%is considered to be an optional experimental condition.Therefore,under this condition,the effects of Fe_(78)Si_(9)B_(13)^(AP)and zero-valent iron(ZVI)as PRB on the removal rate of total Cu in soil and the transformation of chemical forms of Cu are studied.Compared with ZVI,Fe_(78)Si_(9)B_(13)^(AP)as PRB has a better remediation effect.EK-Fe_(78)Si_(9)B_(13)^(AP)can remove 80.3%of total Cu in soil,and the biologically available Cu is reduced to 3.6%,which effectively reduces the environmental risk of contaminated soil.展开更多
The contamination of shampoo with bacteria is not very common but can happen and can be a potential cause of conjunctivitis. This case report describes a 24-year-old male who developed conjunctivitis after using a Ser...The contamination of shampoo with bacteria is not very common but can happen and can be a potential cause of conjunctivitis. This case report describes a 24-year-old male who developed conjunctivitis after using a Serratia marcescens contaminated shampoo in a fitness club. The patient had redness, swelling, and discharge in both eyes. Cultures of the shampoo and eye swabs were positive for S. marcescens with indistinguishable DNA fingerprints. The patient was treated with an eye drop antibiotic and his symptoms resolved within a week. This case highlights the possibility of exposure in places where shampoos containers are refilled or shared. The avoidance of refilling them and using replaceable cartridges, single-sealed refill bags, or bringing personal shampoo is highly recommended to prevent such incidents.展开更多
The comparative effectiveness of remediating water polluted with crude oil, using environment-friendly bacteria (Pseudomonas aeruginosa) and fungi (Aspergillus niger) were investigated. The samples were separately tre...The comparative effectiveness of remediating water polluted with crude oil, using environment-friendly bacteria (Pseudomonas aeruginosa) and fungi (Aspergillus niger) were investigated. The samples were separately treated with Aspergillus niger and Pseudomonas aeruginosa. The bioremediation kinetic efficiency for these systems was studied. At the end of the bioremediation periods, the oil and grease content of the samples decreased from 47.0 mg/L in the untreated sample to 7.0 mg/L after 20 days when inoculated with bacteria while the sample inoculated with fungi decreased to 10.0 mg/L. Post analysis when inoculated with bacteria showed a fall in the value of the biological oxygen demand (BOD) from 73.84 mg/L to 33.28 mg/L after 20 days, while, the fungi inoculated sample showed a reduction from 73.84 mg/L to 38.48 mg/L. The biodegradation process with the bacteria was consistent with the pseudo-first-order model with a rate constant of 0.0891 day<sup>-1</sup>, while the biodegradation process with the fungi was consistent with the first order reaction model with a rate constant of 0.422 day<sup>-1</sup>. The degree of degradation after the 20<sup>th</sup> day of inoculation with Pseudomonas aeruginosa was 85.11%, while with Aspergillus niger was 78.72%. Thus, the results obtained showed that, Pseudomonas aeruginosa performed better than Aspergillus niger. The bioremediation data with fungi fitted the first-order model, while that of the bacteria fitted the pseudo-first-order model. Therefore, the data obtained in this study could be applied in the design of a bioremediation system for potential application to remediation of crude oil polluted water.展开更多
Two non-destructive analytical techniques (gamma spectrometer and X-ray diffractometer) were employed in the analysis of bauxite and rutile ore and their vicinity soil and control sourced within the Kanam and Wase min...Two non-destructive analytical techniques (gamma spectrometer and X-ray diffractometer) were employed in the analysis of bauxite and rutile ore and their vicinity soil and control sourced within the Kanam and Wase mineral exploration sites. The activity concentrations of natural radionuclides <sup>238</sup>U, <sup>232</sup>Th, and <sup>40</sup>K in the soil samples received from bauxite and rutile mineral mining vicinities revealed high concentrations of <sup>238</sup>U, <sup>232</sup>Th, and <sup>40</sup>K compared to the control soil samples sourced 500 m away from the mineral exploration vicinities. Radiological detriments RLI, AUI, Hin and Hex unveiled values exceeding the radiation standard concentration (>1) for soil. X-ray diffraction characterization of bauxite ore revealed the interlocking minerals of Bauxite (18)%, Albite (11)%, Garnet (15)%, Illite (6)% and Muscovite (43)% in various proportions obtained within the 2θ range (9.18 to 64.4) and a peak value (intensity, cps) of 3400. Pure bauxite percentage in the ore meets metallurgical grade (15 - 25)%. X-ray diffraction of rutile ore revealed the minerals of rutile (40)%, quartz (21.4)%, ilmenite (27)% and garnet (11.8)% found within the 2θ range (27.5 to 35.6) and a peak value intensity of 31.1 - 100.0 cps also meeting the metallurgical grade of 15% - 25%. The major environmental concern associated with the mineral-sands industry is the radiation hazards, pollution of ground-water sources from heavy metals, mineral transport with heavy equipment’s, dredging operations in fragile coastal area and clearing of vegetation.展开更多
A total of 7,788 tons of treated radioactive water had been discharged into the Pacific Ocean from Japan’s wrecked Fukushima Daiichi Nuclear Power Plant by September 11 in the first round of disposal as planned,said ...A total of 7,788 tons of treated radioactive water had been discharged into the Pacific Ocean from Japan’s wrecked Fukushima Daiichi Nuclear Power Plant by September 11 in the first round of disposal as planned,said the plant operator Tokyo Electric Power Company(TEPCO),according to Japanese daily newspaper Sankei Shimbun.The second round of discharge scheduled for early October will release some 7,800 tons of nuclear-contaminated water.展开更多
The consumption of maize and cowpea in Africa and developing countries is high,owing to the fact that they are readily available,coupled the with nutritional benefits they provide.Growth loss has been seen in crops cu...The consumption of maize and cowpea in Africa and developing countries is high,owing to the fact that they are readily available,coupled the with nutritional benefits they provide.Growth loss has been seen in crops cultivated on heavy metal polluted soils as a consequence of alterations in physiological and biochemical processes.This study was aimed at assessing the growth indices of seeds(maize and cowpea)grown on heavy metal contaminated soil treated with ginger extracts.The study adopted a Complete Randomized Design(CRD)in which growth indices of either maize or cowpea were examined from each crop type grown on soil without any pollutant or treatment and soils with metal pollutants;with or without treatment with ginger extracts in the individual experiments.Data were analyzed using ANOVA.The results showed that ginger extract induced oxidative stress on cowpea after 10 days of cultivation with root length significantly(P≤0.05)higher on the normal control-G-M and+L-G which recorded 7.60 and 7.3 cm respectively.Patterns of growth indices noticed after 30 and 40 days of cowpea cultivation were variable showing least growth in leaf development.Highest maize root(27.00 cm),shoot(8.85 cm)and leaf(25.25 cm)development were recorded in maize grown on soil without metal contamination but treated with ginger(+G-M-positive control)after days 10,40 and 40 after cultivation.It was observed that the soil contaminated with heavy metals affected the growth pattern of the crops thereby causing stunted growth,chlorosis,discoloration and wilting.It could be concluded that cowpea performed better in shoot of both treated and untreated soils even though the values were not significantly different from that of root and leaf while maize showed a decrease in shoot even though the values for root and leaf were not significantly different.展开更多
Fractional factorial split-plot design has been widely used in many fields due to its advantage of saving experimental cost. The general minimum lower order confounding criterion is usually used as one of the attracti...Fractional factorial split-plot design has been widely used in many fields due to its advantage of saving experimental cost. The general minimum lower order confounding criterion is usually used as one of the attractive design criterion for selecting fractional factorial split-plot design. In this paper, we are interested in the theoretical construction methods of the optimal fractional factorial split-plot designs under the general minimum lower order confounding criterion. We present the theoretical construction methods of optimal fractional factorial split-plot designs under general minimum lower order confounding criterion under several conditions.展开更多
中国生态系统研究网络(Chinese Ecosystem Research Network,CERN)生物长期样地背景和植被分类特征本底数据集是22个CERN自然生态系统生态站95个长期样地的本底数据的综合集成。基于对CERN生态站长期样地地理位置、建立时间、面积、样...中国生态系统研究网络(Chinese Ecosystem Research Network,CERN)生物长期样地背景和植被分类特征本底数据集是22个CERN自然生态系统生态站95个长期样地的本底数据的综合集成。基于对CERN生态站长期样地地理位置、建立时间、面积、样地代表性等背景信息的梳理,依据样地建立之初的植物群落调查数据,参照最新的中国植被分类系统,对每个样地植物群落所属的植被型组、植被型、植被亚型进行了明确划分,并依据每个样地的优势种名单,对样地植被所属群系和群丛进行了鉴定和命名。本数据集构建通过了多轮的专家审核-台站核查-专家复审-台站接受等过程,包含生态站代码、生态站名称、样地代码、样地名称、样地类别、样地代表性、地理位置、海拔高度、样地面积及形状、样地建立时间和设计使用年数、植被型组、植被型、植被亚型、群系、群丛、优势种等信息。本数据集可以为植物区系、植被资源分布、生物多样性保护等方面的研究提供基础数据支持。展开更多
文摘Crude oil spills have inflicted extensive disruption upon the Niger Delta ecosystem, resulting in crop loss and severe environmental damage. Such spills exacerbate heavy metal concentration within soil due to the presence of metallic ions. The Okpare-Olomu community has borne the brunt of crude oil pollution from illicit bunkering, sabotage, and equipment malfunction. This study targets an evaluation of ecological hazards linked to heavy metals (HMs) in crude oil impacted agriculturally soils within Okpare-Olomu in Ughelli South LGA of Delta State. In this study, 24 topsoil samples were obtained from areas affected by crude oil pollution;the heavy metal content was evaluated through atomic absorption spectrometry. The concentration ranges for HMs (mg/kg) in soil were: 24.1 - 23,174 (Cu);0.54 - 37.1 (Cd);9.05 - 54 (Cr);12 - 174 (Ni);18.5 - 8611 (Pb);and 148 - 9078 (Zn) at a soil depth of 0 - 15 cm. Notably, metal concentrations were recorded to be above permissible World Health Organization limits. Predominantly, Zn and Pb recorded higher heavy metal concentration when compared to other heavy metals analysed, notably at sampling points PT7 through PT24. Zinc and Pb contamination exhibited highly significant contamination factors, and contamination severity was evidenced across all sample points, signifying a grave risk level. Pollution load indices indicated pervasive extreme pollution levels. Geoaccumulation indices signaled moderate to strong pollution, mainly by Pb and Zn. Ecological risk assessments revealed variable levels of heavy metal contamination, from low to very high, with potential ecological risk reflecting markedly elevated levels. This study underscores the imperative for soil remediation to rectify ecological imbalances in agriculturally affected soil constituents.
文摘Heavy metal contaminated water sources pose serious health risks for humans,animals,and plants.Exposure to and ingestion of heavy metals have been associated to liver,kidney,and brain function.Objective:The aim of this research is to comparatively examine the metal removal efficacy of three solid bidentate chemicals and four plant materials.Study Design&Methods:Standard solutions of zinc(II)and lead(II)ions with concentrations of 1,000 ppm were respectively treated with OA(Oxalic Acid),dibasic bidentate ligands(sodium hydrogen phosphate and sodium carbonate).Then,the solutions were placed on a shaker for 15 h,centrifuged,and the supernatant was analyzed using ICP-AES(Inductively Coupled Plasma-Atomic Emission Spectrometry).Results:All the solid bidentate adsorbents were very effective in removing zinc and lead(>90%).However,more lead than zinc was removed across all adsorbents except for lemon where equal percent of zinc and lead(49%)were removed.OA and Na2HPO4 removed about equal amount of lead(>99%).The plant materials(SP(Spinach),bell pepper and GBP(Green Bell Pepper)),respectively and preferentially removed more lead(98.9%,98.3%,81.5%)than zinc(91.7%,46%,46%).Conclusion:Although plant materials have gained attraction for the remediation of heavy metal,however,some bidentate chemical ligands such as OA,sodium carbonate and sodium hydrogen phosphates are even more effective in removing these metals from contaminated water.Furthermore,heavier metals are preferentially removed than lighter metals.
基金supported by the National Defense Science and Technology Outstanding Youth Science Fund Project(2018-JCJQ-ZQ-023)the Hunan Provincial Natural Science Foundation of Innovation Research Group Project(2019JJ10004)。
文摘Recognition of pulse repetition interval(PRI)modulation is a fundamental task in the interpretation of radar intentions.However,the existing PRI modulation recognition methods mainly focus on single-label classification of PRI sequences.The prerequisite for the effectiveness of these methods is that the PRI sequences are perfectly divided according to different modulation types before identification,while the actual situation is that radar pulses reach the receiver continuously,and there is no completely reliable method to achieve this division in the case of non-cooperative reception.Based on the above actual needs,this paper implements an algorithm based on the recurrence plot technique and the multi-target detection model,which does not need to divide the PRI sequence in advance.Compared with the sliding window method,it can more effectively realize the recognition of the dynamically varying PRI mo dulation.
文摘Statistical comparison of two remediation methods: Remedial nutrient solution and enhanced natural attenuation were analyzed in terms of TPH of different soil samples collected from Khana Local Government Area of Rivers State, Nigeria at different locations and placed inside sample bottles labelled A to D and replicated into two, one for each of the above treatment technique. The TPH of the soil was determined using GC analyzer after solvent extraction was carried out using hexane/dichloromethane mixture. Three batches of treatment were performed on the samples at every interval of eight weeks for a duration of six months. The result obtained was analyzed using a two-way ANOVA factorial experimental design to test the significance of the various sources of variation. From the result obtained, source of variation for sample and interactions were non-significantly different from each other which means that irrespective of the number of samples analyzed or the combination of both samples and batches of treatment, they will still not be significantly different from each other. The source of variation for batch and replications were significantly different from each other and this means that irrespective of the batches of treatment applied or the number of replications (methods of treatment used), they will always be significantly different from each other. The individual comparison of each sample showed that the efficiency of the Remedial Nutrient Solution method was better than Enhanced Natural Attenuation method.
基金This research was funded by the National Natural Science Foundation of China(NSFC)[Grant Nos.51661015 and 52061024]the University Innovation Fund Project of Gansu Provincial Department of Education[Grant No.2021B-553]the Natural Science Foundation of Zhejiang Province,China(4304030).
文摘Iron-based amorphous crystalline powder Fe_(78)Si_(9)B_(13)^(AP)is used as a permeability reaction barrier(PRB)combined with an electrokinetic method(EK-PRB)to study the removal rate of Cu in contaminated soil.After treating Cucontaminated soil for 5 days under different voltage gradients and soil water content,the soil pH is between 3.1 and 7.2.The increase of voltage gradient and soil water content can effectively promote the movement of Cu^(2+) to the cathode.The voltage gradient is 3 V/cm,and the water content of 40%is considered to be an optional experimental condition.Therefore,under this condition,the effects of Fe_(78)Si_(9)B_(13)^(AP)and zero-valent iron(ZVI)as PRB on the removal rate of total Cu in soil and the transformation of chemical forms of Cu are studied.Compared with ZVI,Fe_(78)Si_(9)B_(13)^(AP)as PRB has a better remediation effect.EK-Fe_(78)Si_(9)B_(13)^(AP)can remove 80.3%of total Cu in soil,and the biologically available Cu is reduced to 3.6%,which effectively reduces the environmental risk of contaminated soil.
文摘The contamination of shampoo with bacteria is not very common but can happen and can be a potential cause of conjunctivitis. This case report describes a 24-year-old male who developed conjunctivitis after using a Serratia marcescens contaminated shampoo in a fitness club. The patient had redness, swelling, and discharge in both eyes. Cultures of the shampoo and eye swabs were positive for S. marcescens with indistinguishable DNA fingerprints. The patient was treated with an eye drop antibiotic and his symptoms resolved within a week. This case highlights the possibility of exposure in places where shampoos containers are refilled or shared. The avoidance of refilling them and using replaceable cartridges, single-sealed refill bags, or bringing personal shampoo is highly recommended to prevent such incidents.
文摘The comparative effectiveness of remediating water polluted with crude oil, using environment-friendly bacteria (Pseudomonas aeruginosa) and fungi (Aspergillus niger) were investigated. The samples were separately treated with Aspergillus niger and Pseudomonas aeruginosa. The bioremediation kinetic efficiency for these systems was studied. At the end of the bioremediation periods, the oil and grease content of the samples decreased from 47.0 mg/L in the untreated sample to 7.0 mg/L after 20 days when inoculated with bacteria while the sample inoculated with fungi decreased to 10.0 mg/L. Post analysis when inoculated with bacteria showed a fall in the value of the biological oxygen demand (BOD) from 73.84 mg/L to 33.28 mg/L after 20 days, while, the fungi inoculated sample showed a reduction from 73.84 mg/L to 38.48 mg/L. The biodegradation process with the bacteria was consistent with the pseudo-first-order model with a rate constant of 0.0891 day<sup>-1</sup>, while the biodegradation process with the fungi was consistent with the first order reaction model with a rate constant of 0.422 day<sup>-1</sup>. The degree of degradation after the 20<sup>th</sup> day of inoculation with Pseudomonas aeruginosa was 85.11%, while with Aspergillus niger was 78.72%. Thus, the results obtained showed that, Pseudomonas aeruginosa performed better than Aspergillus niger. The bioremediation data with fungi fitted the first-order model, while that of the bacteria fitted the pseudo-first-order model. Therefore, the data obtained in this study could be applied in the design of a bioremediation system for potential application to remediation of crude oil polluted water.
文摘Two non-destructive analytical techniques (gamma spectrometer and X-ray diffractometer) were employed in the analysis of bauxite and rutile ore and their vicinity soil and control sourced within the Kanam and Wase mineral exploration sites. The activity concentrations of natural radionuclides <sup>238</sup>U, <sup>232</sup>Th, and <sup>40</sup>K in the soil samples received from bauxite and rutile mineral mining vicinities revealed high concentrations of <sup>238</sup>U, <sup>232</sup>Th, and <sup>40</sup>K compared to the control soil samples sourced 500 m away from the mineral exploration vicinities. Radiological detriments RLI, AUI, Hin and Hex unveiled values exceeding the radiation standard concentration (>1) for soil. X-ray diffraction characterization of bauxite ore revealed the interlocking minerals of Bauxite (18)%, Albite (11)%, Garnet (15)%, Illite (6)% and Muscovite (43)% in various proportions obtained within the 2θ range (9.18 to 64.4) and a peak value (intensity, cps) of 3400. Pure bauxite percentage in the ore meets metallurgical grade (15 - 25)%. X-ray diffraction of rutile ore revealed the minerals of rutile (40)%, quartz (21.4)%, ilmenite (27)% and garnet (11.8)% found within the 2θ range (27.5 to 35.6) and a peak value intensity of 31.1 - 100.0 cps also meeting the metallurgical grade of 15% - 25%. The major environmental concern associated with the mineral-sands industry is the radiation hazards, pollution of ground-water sources from heavy metals, mineral transport with heavy equipment’s, dredging operations in fragile coastal area and clearing of vegetation.
文摘A total of 7,788 tons of treated radioactive water had been discharged into the Pacific Ocean from Japan’s wrecked Fukushima Daiichi Nuclear Power Plant by September 11 in the first round of disposal as planned,said the plant operator Tokyo Electric Power Company(TEPCO),according to Japanese daily newspaper Sankei Shimbun.The second round of discharge scheduled for early October will release some 7,800 tons of nuclear-contaminated water.
文摘The consumption of maize and cowpea in Africa and developing countries is high,owing to the fact that they are readily available,coupled the with nutritional benefits they provide.Growth loss has been seen in crops cultivated on heavy metal polluted soils as a consequence of alterations in physiological and biochemical processes.This study was aimed at assessing the growth indices of seeds(maize and cowpea)grown on heavy metal contaminated soil treated with ginger extracts.The study adopted a Complete Randomized Design(CRD)in which growth indices of either maize or cowpea were examined from each crop type grown on soil without any pollutant or treatment and soils with metal pollutants;with or without treatment with ginger extracts in the individual experiments.Data were analyzed using ANOVA.The results showed that ginger extract induced oxidative stress on cowpea after 10 days of cultivation with root length significantly(P≤0.05)higher on the normal control-G-M and+L-G which recorded 7.60 and 7.3 cm respectively.Patterns of growth indices noticed after 30 and 40 days of cowpea cultivation were variable showing least growth in leaf development.Highest maize root(27.00 cm),shoot(8.85 cm)and leaf(25.25 cm)development were recorded in maize grown on soil without metal contamination but treated with ginger(+G-M-positive control)after days 10,40 and 40 after cultivation.It was observed that the soil contaminated with heavy metals affected the growth pattern of the crops thereby causing stunted growth,chlorosis,discoloration and wilting.It could be concluded that cowpea performed better in shoot of both treated and untreated soils even though the values were not significantly different from that of root and leaf while maize showed a decrease in shoot even though the values for root and leaf were not significantly different.
文摘Fractional factorial split-plot design has been widely used in many fields due to its advantage of saving experimental cost. The general minimum lower order confounding criterion is usually used as one of the attractive design criterion for selecting fractional factorial split-plot design. In this paper, we are interested in the theoretical construction methods of the optimal fractional factorial split-plot designs under the general minimum lower order confounding criterion. We present the theoretical construction methods of optimal fractional factorial split-plot designs under general minimum lower order confounding criterion under several conditions.
文摘中国生态系统研究网络(Chinese Ecosystem Research Network,CERN)生物长期样地背景和植被分类特征本底数据集是22个CERN自然生态系统生态站95个长期样地的本底数据的综合集成。基于对CERN生态站长期样地地理位置、建立时间、面积、样地代表性等背景信息的梳理,依据样地建立之初的植物群落调查数据,参照最新的中国植被分类系统,对每个样地植物群落所属的植被型组、植被型、植被亚型进行了明确划分,并依据每个样地的优势种名单,对样地植被所属群系和群丛进行了鉴定和命名。本数据集构建通过了多轮的专家审核-台站核查-专家复审-台站接受等过程,包含生态站代码、生态站名称、样地代码、样地名称、样地类别、样地代表性、地理位置、海拔高度、样地面积及形状、样地建立时间和设计使用年数、植被型组、植被型、植被亚型、群系、群丛、优势种等信息。本数据集可以为植物区系、植被资源分布、生物多样性保护等方面的研究提供基础数据支持。
