manganese concentration
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Author(s):  
Meixian Wang ◽  
Yan Tian ◽  
Ping Yu ◽  
Nana Li ◽  
Ying Deng ◽  
...  

Abstract To investigate the correlation between maternal manganese and iron concentrations and the risk of CHD among their infant. A multi-center hospital-based case control study was conducted in China. There were 322 cases and 333 controls have been selected from pregnant women who received prenatal examinations. Correlations between CHDs and maternal manganese and iron concentrations were estimated by conditional logistic regression. Moreover, the interaction between manganese and iron on CHDs was analyzed. Compared with the controls, mothers whose hair manganese concentration was 3.01 μg/g or more were more likely to have a child with CHD than those with a lower concentration. The adjusted OR was 2.68 (95%CI = 1.44–4.99). The results suggested that mothers whose iron content was 52.95 μg/g or more had a significantly higher risk of having a child with CHD (aOR = 2.87, 95%CI = 1.54–5.37). No interaction between maternal manganese and iron concentrations was observed in the multiplicative or additive model. The concurrently existing high concentration of manganese and iron may bring higher risk of CHD (OR = 7.02). Women with excessive manganese concentrations have a significantly increased risk of having offspring with CHDs. The high maternal iron status also correlates with CHDs. The concurrently existing high concentration of manganese and iron may bring higher risk of CHD.


2021 ◽  
Vol 2086 (1) ◽  
pp. 012129
Author(s):  
A N Babkina ◽  
M S Kovova ◽  
E V Kulpina ◽  
A S Pavliuk ◽  
K S Zyryanova ◽  
...  

Abstract A series of lithium-germanate glasses with different manganese concentration is synthesized. Li2Ge7O15 nanocrystals nucleate in the glass matrix via standard volume crystallization technique thus obtaining lithium-germanate glass-ceramics. The glass-ceramics possess intense emission near 660-670 nm under two-band excitation at 330 and 450 nm. The luminescence lifetime is 550 μs for 0.05 mol.% MnO2-doped glass-ceramics. The glass-ceramics obtained can be used as a source of deep-red radiation.


Author(s):  
А.В. Селюков ◽  
М.Ю. Семенов ◽  
И.С. Байкова

Рассматривается опыт применения озонирования речной воды в лабораторных и пилотных масштабах. Вода реки Тобол – жесткая минерализованная со средними значениями цветности 24 град, содержанием марганца в зимний период более 0,8 мг/дм3. После определения рабочих доз реагентов (коагулянт гидроксохлорид алюминия, флокулянт Praestol 650TR) проводилось пробное озонирование с последующей реагентной обработкой на лабораторном флокуляторе. Для достижения норматива по содержанию марганца в речной воде 0,1 мг/дм3 потребовались высокие дозы озона – от 35 мг/дм3. Подщелачивание исходной воды до рН 9 позволило снизить дозу озона до 23 мг/дм3. Снижение цветности до 15 град происходит при дозах озона 6–7 мг/дм3. Очистка речной воды на пилотной установке производительностью 50 л/ч проводилась по полной технологической схеме (озонирование, обработка коагулянтом и флокулянтом, отстаивание, фильтрование через песчаный фильтр, фильтрование через угольный фильтр, опреснение-умягчение обратным осмосом). Доза коагулянта составляла 5 мг/дм3, флокулянта – 0,3 мг/дм3. В стационарном режиме работы пилотной установки при дозе озона 25 мг/дм3 были достигнуты следующие показатели качества фильтрата песчаного фильтра: цветность 5–7 град; марганец 0,05–0,15 мг/дм3; железо общее 0,02–0,03 мг/дм3; алюминий 0,05–0,08 мг/дм3; перманганатная окисляемость 3–4 мг/дм3. Исходя из расчетных показателей состава воды р. Тобол, для концентрации марганца в воде 0,8 мг/дм3теоретическая доза озона составляет ≈ 8 мг/дм3, проектная доза озона может быть принята 10 мг/дм3 (г/м3). The experience of using ozonation of river water on a laboratory and pilot scale is considered. The water of the Tobol River is hard and mineralized with an average color value of 24 degrees, a manganese concentration in the winter period of more than 0.8 mg/dm3. After determining the operational doses of the chemicals (polyaluminum chloride coagulant, Praestol 650TR flocculant), test ozonation was carried out followed by the chemical treatment in a laboratory flocculator. To achieve the standard for manganese concentration in river water of 0.1 mg/dm3, high doses of ozone were required – from 35 mg/dm3. Alkalinization of the initial water to pH 9 provided for reducing the ozone dose to 23 mg/dm3. A decrease in color to 15 degrees occurred at ozone doses of 6–7 mg/dm3. River water purification at a pilot plant with a capacity of 50 l/h was carried out according to the complete process flow scheme (ozonation, treatment with coagulant and flocculant, sedimentation, filtration in a sand filter, filtration in a carbon filter, desalination-softening by reverse osmosis). The coagulant dose was 5 mg/dm3, and that of the flocculant – 0.3 mg/dm3. In the steady run of the pilot plant at an ozone dose of 25 mg/dm3, the following quality indicators of the sand filter filtrate were achieved: color 5–7 degrees; manganese 0.05–0.15 mg/dm3; total iron 0.02–0.03 mg/dm3; aluminum 0.05–0.08 mg/dm3; permanganate index 3–4 mg/dm3. Based on the estimate indicators of the Tobol River water composition related to the manganese concentration in water of 0.8 mg/dm3, the theoretic dose of ozone is ≈ 8 mg/dm3, the design dose of ozone can be assumed as 10 mg/dm3 (g/m3).


2021 ◽  
Vol 11 (3) ◽  
pp. 134-145
Author(s):  
Ibiang Arikpo Oka ◽  
Sylvanus Akpak Upula

Inadequate safe and portable water supply particularly in underdeveloped and developing countries has been associated with posing serious public health implications, especially as water related diseases continue to be a major health challenge in resource limited settings worldwide. Physicochemical and bacteriological parameters of borehole and spring water sources in a sub-urban community were assessed to determine their potability and correlation index. Twenty (20) water samples, 10 from boreholes and 10 from springs were randomly collected from different locations and analysed using standard microbiological and physicochemical methods. The results were compared with NIS and WHO standards for drinking water. Physicochemical parameters including; temperature, pH, turbidity, electrical conductivity, total hardness, total dissolved solid, Iron, Manganese, Zinc, Chloride, Sodium, Nitrate, Ammonium and Potassium were determined following the procedures prescribed by American Public Health Association Standard Method. Results obtained revealed that 99.3% of the analysed physicochemical parameters were within the maximum acceptable limits of NIS and WHO guidelines for drinking water except borehole iron concentration (0.52mg/L) and Manganese concentration (0.14mg/L). The total heterotrophic bacterial count (THB), total coliform count and faecal coliform count ranged from 1.6x103cfu/100ml to 4.7x103cfu/100 ml, 8.0cfu/100ml to 25cfu/ml, 0cfu/100ml to 14cfu/100ml respectively for boreholes, and 1.7x103cfu/100ml to 4.6x103cfu/100ml, 10cfu/100ml to 21cfu/100ml, 9cfu/100ml to 17cfu/100ml respectively for samples from spring water supply. Phenotypic characterization of the samples revealed the presence of certain organisms with pathogenic potentials such as Staphylococcus aureus 27.5%, followed by E. coli 19.6%, P. aeruginosa 11.8%, Klebsiella spp. 9.8%, Enterobacter spp. 7.8%, Enterococcus spp. 7.8%, Lactobacillus spp. 5.9%, Proteus spp. 3.9%, Shigella spp. 3.9% and Vibrio cholerae 2.0%. Pearson’s correlation analysis showed significantly strong positive correlation between total heterotrophic bacteria count and total coliforms (r = 0.643) and strong negative correlation between pH and total dissolved solids (r = -0.640). Other parameters such as faecal coliform, temperature, pH, turbidity, Zinc, Ammonium and Sodium shows significant correlation among variables.


2021 ◽  
pp. 1-8
Author(s):  
Michal Ordak ◽  
Natalia Sloniewicz ◽  
Tadeusz Nasierowski ◽  
Elzbieta Muszynska ◽  
Magdalena Bujalska-Zadrozny

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3081
Author(s):  
Lena Heemann ◽  
Farhad Mostaghimi ◽  
Bernd Schob ◽  
Frank Schubert ◽  
Lothar Kroll ◽  
...  

Medium manganese steels can exhibit both high strength and ductility due to transformation-induced plasticity (TRIP), caused by metastable retained austenite, which in turn can be adjusted by intercritical annealing. This study addresses the laser additive processability and mechanical properties of the third-generation advanced high strength steels (AHSS) on the basis of medium manganese steel using Laser Powder Bed Fusion (LPBF). For the investigations, an alloy with a manganese concentration of 5 wt.% was gas atomized and processed by LPBF. Intercritical annealing was subsequently performed at different temperatures (630 and 770 °C) and three annealing times (3, 10 and 60 min) to adjust the stability of the retained austenite. Higher annealing temperatures lead to lower yield strength but an increase in tensile strength due to a stronger work-hardening. The maximum elongation at fracture was approximately in the middle of the examined temperature field. The microstructure and properties of the alloy were further investigated by scanning electron microscopy (SEM), hardness measurements, X-ray diffraction (XRD), electron backscatter diffraction (EBSD) and element mapping.


2021 ◽  
Vol 12 ◽  
Author(s):  
Mahendar Thudi ◽  
Yinglong Chen ◽  
Jiayin Pang ◽  
Danamma Kalavikatte ◽  
Prasad Bajaj ◽  
...  

Chickpea—the second most important grain legume worldwide—is cultivated mainly on marginal soils. Phosphorus (P) deficiency often restricts chickpea yields. Understanding the genetics of traits encoding P-acquisition efficiency and P-use efficiency will help develop strategies to reduce P-fertilizer application. A genome-wide association mapping approach was used to determine loci and genes associated with root architecture, root traits associated with P-acquisition efficiency and P-use efficiency, and any associated proxy traits. Using three statistical models—a generalized linear model (GLM), a mixed linear model (MLM), and a fixed and random model circulating probability unification (FarmCPU) —10, 51, and 40 marker-trait associations (MTAs), respectively were identified. A single nucleotide polymorphism (SNP) locus (Ca1_12310101) on Ca1 associated with three traits, i.e., physiological P-use efficiency, shoot dry weight, and shoot P content was identified. Genes related to shoot P concentration (NAD kinase 2, dynamin-related protein 1C), physiological P-use efficiency (fasciclin-like arabinogalactan protein), specific root length (4-coumarate–CoA ligase 1) and manganese concentration in mature leaves (ABC1 family protein) were identified. The MTAs and novel genes identified in this study can be used to improve P-use efficiency in chickpea.


2021 ◽  
Vol 8 (2) ◽  
pp. 109-119
Author(s):  
Mudasra Munir ◽  
Kafeel Ahmad ◽  
Zafar Iqbal Khan ◽  
Asmat Zahra ◽  
Asma Ashfaq ◽  
...  

Heavy metals are considered as most important contaminations due to industrialization of countries and an influence on its existence in soil, plant and milk. A study was carried out to check manganese content in soil, forage and milk at three sites of city Jhang, Punjab, Pakistan. All samples (milk, soil, water, fodder plants and ground water) were analyzed for manganese by Atomic Absorption Spectrophotometer. Different health indices were also studied to check Mn flow in food chain. Level of Mn in samples was found within acceptable limits. Manganese level was higher in soil samples collected from Site-III than other sites. Manganese showed higher value (2.595 to 10.402 mg/kg) in soil than other samples. Fodders were found to accumulate manganese from 0.008 to 0.022 mg/kg. Manganese concentration was found to be 0.1482 to 1.241 mg/L, 0.164 to 0.9708 mg/L in water and milk, respectively. BCF and PLI values for manganese were also found to be less than 1. Estimated daily intake (EDI) and THQ of manganese are found within permissible limits in milk of cows feeding on fodders irrigated with wastewater and ground water. So, use of wastewater for irrigation purpose should be properly checked due to possible toxic effects.


2021 ◽  
pp. 108-116
Author(s):  
Emad M. Elsehly

Carbon nanotubes (CNTs) based filters have a prospective advantage compared to the commercial filters due to their lightweight and ability to work without electricity or heat. The manganese (Mn) removal from aqueous solutions by oxidized multi-walled carbon nanotubes (O-MWCNTs) was investigated. The filtration performance was studied under ambient conditions: the solution pH, the initial manganese concentration, and the MWCNT-filter mass. The samples of MWCNT-filters were investigated using energy dispersive X-ray spectroscopy (EDS) and rutherford backscatter spectrometry (RBS) to account for the manganese content within the MWCNT-filter. These techniques were conducted to study the oxidation effect on the morphology of MWCNTs and evaluate the oxygen functional groups and the average diameter distribution. Based on these examinations, the competence of Mn removal may exceed 91% for 50 ppm initial concentration of Mn, proposing that functionalized MWCNTs is a promising filter. The Mn removal was achieved at low pH with removal enhancement at the pH of 2. Functionalized MWCNTs based filters are promising candidate for heavy metal ions removal from industrial wastewater.


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