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Author(s):  
Ebimobowei Assayomo ◽  
Dorcas Dauta Bawo ◽  
Gbe-emi kemepade Dieware ◽  
Amaka Mariagoretti Buseri ◽  
Ebikabowei John Debekeme

Aims: Anthropogenic activities such as crude oil exploration and exploitation has led to the suspicion of heavy metals contamination in the study area. This study investigated the concentration of zinc, nickel, lead and cadmium in the soil extracted from the area where Scent Leaf (Ocimum gratissimum) and Pawpaw tree (Carica papaya) are grown in Amassoma community, Bayelsa State, Nigeria. Study Design: Scent leaf (Ocimum gratissimum) and Pawpaw tree (Carica papaya) soils from where these plants are grown were randomly collected for heavy metal analysis from within Amassoma community in Southern Ijaw Local Government Area of Bayelsa State, Nigeria Place and Duration of Study: This study was carried out in Biological Sciences, Faculty of Science, Niger Delta University, Wilberforce Island, Amassoma, Bayelsa State between March 2019 to September 2019 Methodology:  Scent leaf (Ocimum gratissimum) and Pawpaw tree (Carica papaya) soils were digested and analyzed for heavy metals using Atomic Absorption Spectrophotometer (AAS, model S471096). The method used was wet-ashing method for the analysis. Results: the concentrations of Lead (Pb), Nickel (Ni), Cadmium (Cd), and Zinc (Zn), in pawpaw soil and scent leaf soil. From the sample data analysis, the average lead (Pb) contents in pawpaw soil and scent leaf soil were 1.283 mg/kg and 1.44 mg/kg respectively. The average Cadmium (Cd) in pawpaw soil and scent leaf soil were 0.256 mg/kg and 0.256 mg/kg respectively. The average Nickel (Ni) compositions in pawpaw soil and scent leaf soil were 4.71 mg/kg and 5.09 mg/kg respectively. While the Average Zinc (Zn) in pawpaw soil and scent leaf soil is 2.280 mg/kg and 2.160 mg/kg respectively. The soil analyzed for heavy metals were below the threshold target values recommended by the WHO. Conclusion: The Scent leaf (Ocimum gratissimum) and Pawpaw tree (Carica papaya) soils analyzed for heavy metals were below the permissible limit recommended by WHO for soil safety. The result from the present study revealed that there may not be soil contamination as a result of the selected heavy metals, however, It is recommended that caution should be taken in regulating the anthropogenic activities that may tend to elevate the level of heavy metals in the surrounding to prevent contamination of soil over time which could be detrimental to the health of the populace.


Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1554
Author(s):  
Mohammed Alnahhal ◽  
Diane Ahrens ◽  
Bashir Salah

Shipment consolidation is one of main initiatives to reduce CO2 emissions and transportation cost. It reduces the number of shipments per customer and reduces transportation costs by using larger shipments. This paper investigates the temporal consolidation process in a central consolidation center in a make-to-order supply chain. This research was motivated by a case study of a design furniture company that has many suppliers and customers in large parts of Europe. Simulation was used to check the effect of a new and a special time-based temporal consolidation on the response time in outbound logistics. A soft delivery deadline that is less than the average lead time was used because of the long lead time. Arena Software was used to model the supply chain in order to find the best circumstances to use consolidation. Results showed that temporal consolidation could be more effective when order preparation time is with larger variability. The useful waiting is more when there is at least one order every four days. A formula that approximates the percent of reduced shipments was found. Furthermore, many shipments can be reduced without severely affecting the average response time. The value of the study is that it investigates consolidation problems in a high-mix low-volume environment that was overlooked by previous research.


2021 ◽  
pp. 106002802110233
Author(s):  
C. Michael White

Objective Assess the current daily interim reference level of lead and the amount contained in current mineral and multivitamin-multimineral (MVM) products. Data Sources PubMed search from 1980 to May 15, 2021, limited to the English language, via the search strategy ((mineral OR multivitamin OR calcium OR iron OR magnesium OR copper OR zinc OR chromium OR selenium) AND (heavy metals OR Pb OR lead)). Study Selection and Data Extraction Narrative review of studies assessing lead content in mineral or MVM products. Data Synthesis Products containing different calcium forms (dolomite, bone meal, natural carbonate) have historically had higher lead levels than others (refined carbonate, lactate, gluconate, acetate, sevelamer), but the gap has closed considerably since the year 2000. Although only limited assessments of magnesium and zinc supplements have been conducted, no alarming average lead amounts were found. MVM products assessed since 2007 had low median or mean lead concentrations. However, large interproduct differences exist, with many products having very little lead and some products having concerning amounts. Relevance to Patient Care and Clinical Practice It is difficult for pharmacists and consumers to know the amount of lead in an actual product unless it is tested in an independent third-party lab. The United States Pharmacopeia and NSF International will provide a seal on the products stating that the products have a low level of lead, but even so, children could receive more lead than the Food and Drug Administration’s Interim Reference Level. Conclusions The threat from lead exposure in mineral and MVM products have diminsihed considerably over time but some products can still have excessive amounts. Without third-party testing, it is difficult for clinicians and consumers to know which outlier products to avoid.


2021 ◽  
Vol 70 (1-2) ◽  
pp. 11-14
Author(s):  
Miroslava Polovinski Horvatović ◽  
Ivan Radović ◽  
Igor Jajić ◽  
Saša Krstović ◽  
Mile Mirkov

Summary The purpose of this research is to investigate the occurrence of two heavy metals (namely cadmium (Cd) and lead (Pb)) in the liver of hogs bred in different locations in Vojvodina. A total of 30 liver samples were collected from ten pig farms in Vojvodina for experimental purposes in the period from December 2017 to January 2018. The samples collected were analysed for the presence of lead and cadmium. The average concentration of lead in all the samples was 0.39 mg/kg wet weight, whereas the samples from only one farm of the ten considered were found to contain a slightly higher average lead concentration than permitted by the Serbian standard. A lead concentration of 0.86 mg/kg wet weight was detected in one liver sample from this farm. The maximum permitted lead concentration was exceeded in the liver samples obtained from three farms. However, all the liver samples analysed were found to contain the permitted levels of cadmium, with an average cadmium concentration of 0.12 mg/kg wet weight and a maximum cadmium concentration of 0.48 mg/kg wet weight. The occurrence of heavy metals and their origin in the pig’s offals should be examined in greater detail in future research, especially because pig’s offals are used in the meat processing industry.


Author(s):  
Christian Reiter ◽  
Thomas Prohaska

SummaryTwo different strands of hair taken from Beethoven’s head after his death were examined for heavy metals using scanning electron microscopy (SEM) and laser ablation-ICP-MS (inductively coupled plasma–mass spectroscopy). The results revealed the presence of small lead particles on the surface of Beethoven’s hairs and fluctuating lead levels in hair medulla along the length of the hair due to alternating lead exposure, with an average lead exposure of 100 times the normal value. The time-line attached to the peaks of these fluctuating values correlate with the pneumonia treatment and the paracenteses performed, including the subsequent treatment of the procedure wounds. While the administration of lead-containing drugs and treatments had been proven to resolve the pneumonia, it had simultaneously caused massive liver failure, accelerated by pre-existing cirrhosis. The question as to whether Beethoven’s death was a case of malpractice can only be answered from a forensic point of view ex ante, since the state of the medical knowledge of the time has to be taken into account.


2021 ◽  
Author(s):  
Philipp Büttner ◽  
Jens Gutzmer ◽  
Jonathan Engelhardt ◽  
Mirko Martin

<p>The Davidschacht tailings storage facility (TSF), operated from 1944 to 1964, represents one of the largest tailings dams in the historic Freiberg mining district. It contains a volume of 760,000 m³ of sulfidic flotation tailings, residues of former base metal and silver ore beneficiation. The tailings material still contains elevated concentrations of valuable elements such as zinc (0.4 wt.% on average), lead (0.2 wt.%) and copper (0.05 wt.%) as well as indium (10 ppm). The material has thus become the focus of efforts to enable eventual re-mining and recovery of valuable metals. However, such efforts have to take into account a number of important interests of the public. The first of these is the fact that the unrehabilitated tailings pose a significant risk to the environment. Cd (44 ppm on average) and As (0.6 wt.%) concentrations are particularly high – and have a marked influence on the adjacent water bodies, such as the Freiberg Mulde river. Curbing this influence has been the subject of multiple remediation studies, but pressure to act has risen recently due to increasing regulatory demands on the quality of surface water (EU Water Framework Directive of 2000). This is, in principle, very much in favor of re-mining the tailings in an effort to remove also hazardous components. Counteracting this reclamation scenario is the fact that the TSF is part of the UNESCO World Heritage Site “Erzgebirge / Krusne Hory” that was awarded in 2019. Another restriction pertains to the highly protected status of individual species (esp. sand lizard) settling on the TSF surface. This constellation obviously provides ample space for discussion as to how to deal with the tailings material contained in the Davidschacht TSF in future. Different sustainable development goals (SDG) have to be weighed against each other in order to find a holistic and sustainable. Airlift reactor-based bioleaching has been considered as an opportunity to maximize the sustainability of re-mining activities on the Davidschacht TSF. This innovative approach – and its circumstantial limitations – are documented in this contribution.</p>


Author(s):  
Gregory J. Stumpf ◽  
Alan E. Gerard

AbstractThreats-in-Motion (TIM) is a warning generation approach that would enable the NWS to advance severe thunderstorm and tornado warnings from the current static polygon system to continuously updating polygons that move forward with a storm. This concept is proposed as a first stage for implementation of the Forecasting a Continuum of Environmental Threats (FACETs) paradigm, which eventually aims to deliver rapidly updating probabilistic hazard information alongside NWS warnings, watches, and other products.With TIM, a warning polygon is attached to the threat and moves forward along with it. This provides more uniform, or equitable, lead time for all locations downstream of the event. When forecaster workload is high, storms remain continually tracked and warned. TIM mitigates gaps in warning coverage and improves the handling of storm motion changes. In addition, warnings are automatically cleared from locations where the threat has passed. This all results in greater average lead times and lower average departure times than current NWS warnings, with little to no impact to average false alarm time. This is particularly noteworthy for storms expected to live longer than the average warning duration (30 or 45 minutes) such as long-tracked supercells that are more prevalent during significant tornado outbreaks.


Author(s):  
H. N. Kharkhal ◽  
L. P. Titov ◽  
O. O. Yanovich

The objective of the article was to determine the variability of meningococcal house-keeping gene alleles circulating in Belarus. House-keeping genes sequencing was made by Sanger (ABI 3500). The phylogenetic analysis was done in MEGA X. SNPs were analyzed at pubMLST.org. 60 Belarusian meningococci, collected during 8 years, contain 17 alleles of abcZ gene (5.9 % first identified in Belarus – abcZ 1016) encoding 5 variants of the ABC transporter; 16 adk gene alleles – 2 variants of adenylate cyclase; 17 alleles of aroE gene (11.8 % Belarusian – aroE 944 and aroE 972) – 14 variants of shikimat dehydrogenase; 24 alleles of fumC gene (4.2 % Belarusian – fumC 988) – 4 variants of fumarate dehydratase; 18 alleles of gdh gene (16.7 % first identified in Belarus – gdh 560, gdh 985 and gdh 1083) – 4 variants of glucose-6-phosphate dehydrogenase; 18 alleles of pdhC gene – 11 variants of pyruvate dehydrogenase subunit and 20 alleles of pgm gene – 13 variants of phosphoglucomutase (5.6 and 5 % of Belarusian alleles − pdhC 888 and pgm 1099 respectively). Dominant alleles are abcZ 8 – 25 %, adk 5 – 30, aroE 6 – 28.3, fumC 17 – 30, gdh 560 – 20, pdhC 18 – 21.7, pgm 2 – 25 %. The Belarusian meningococcal population is diverse and includes both its own house-keeping gene alleles (7.7 %) and those circulating in other countries (92.3 %). The number of SNPs is varied from 29 (adk) to 125 (aroE). Single nucleotide polymorphisms are mostly synonymous and, on average, lead to amino acid substitutions in the range from 0.6 % in adenylate cyclase and up to 26.4 % in shikimat dehydrogenase.


2020 ◽  
Vol 15 (2) ◽  
pp. 192-204
Author(s):  
Soh Ann-Ni ◽  
Puah Chin-Hong ◽  
Arip M. Affendy

AbstractA growing interest is surfacing toward the non-linearities in tourism demand forecasting. This paper aims to construct a tourism composite indicator to anticipate the cyclical movement for the tourism demand in Fiji. The time duration tackled in the current study is under the span of approximately two decades from 2000 to 2017. Apart from an indicator construction approach and turning point dating algorithm, we proposed a two regime Markov switching model to analyse the Fijian tourism cycle. The empirical results revealed the composite leading indicator accorded a signalling approach for Fijian tourism demand with an average lead time of 2.75 months. Furthermore, the prior-recognition of the tourism economic transition with adequate dating evaluation of the tourism cycle is obtained from the filtered probabilities through the Markov switching models.


2020 ◽  
Vol 496 (4) ◽  
pp. 4255-4265
Author(s):  
D R Ballantyne ◽  
X Xiang

ABSTRACT Warm coronae, thick (τT = 10–20, where τT is the Thomson depth) Comptonizing regions with temperatures of ∼1 keV, are proposed to exist at the surfaces of accretion discs in active galactic nuclei (AGNs). By combining with the reflection spectrum, warm coronae may be responsible for producing the smooth soft excess seen in AGN X-ray spectra. This paper studies how a warm corona must adjust in order to sustain the soft excess through large changes in the AGN flux. Spectra from one-dimensional constant density and hydrostatic warm corona models are calculated assuming that the illuminating hard X-ray power law, gas density, Thomson depth, and coronal heating strength vary in response to changes in the accretion rate. We identify models that produce warm coronae with temperatures between 0.3 and 1.1 keV, and measure the photon indices and emitted fluxes in the 0.5–2 and 2–10 keV bands. Correlations and anticorrelations between these quantities depend on the evolution and structure of the warm corona. Tracing the path that an AGN follows through these correlations will constrain how warm coronae are heated and connected to the accretion disc. Variations in the density structure and coronal heating strength of warm coronae will lead to a variety of soft excess strengths and shapes in AGNs. A larger accretion rate will, on average, lead to a warm corona that produces a stronger soft excess, consistent with observations of local Seyfert galaxies.


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