scholarly journals The Chemical Study of Calotropis

2013 ◽  
Vol 20 ◽  
pp. 74-90 ◽  
Author(s):  
Vishwa Nath Verma
Keyword(s):  
Temperature Effects ◽  
Chemical Properties ◽  
Chemical Study ◽  
Calotropis Procera ◽  
Cobalt Chromium ◽  
Ph Values ◽  
Lead And Zinc ◽  
Similar Chemical ◽  
Tlc Plates ◽  
Nickel Lead

Calotropis (Asclepiadaceae) commonly known as “madar” is a useful medicinal plant. The two species i.e. Calotropis gigantea and Calotropis procera are to a great extent having a very similar chemical properties, but the colours of their flowers are different. The pH of latex of these two species has been found different in the present study. The temperature effects have been noticed on their pH values which is varying from 7.2 to 8.1 between the temperatures 25 °C to 45 °C and then remains constant for Calotropis gigantia. The milky latex contains hydrocarbons, fatty acids, sterols and terpenels. Seven spots have been observed on the TLC plates; out of which 3 were identified as calotoxin, uscharin and calactin. Aluminum, calcium, cadmiun, cobalt, chromium, copper, iron, magnese, magnesium, nickel, lead, and zinc metal elements were investigated in the latex and similarly in the leaves and bark from the AA spectra. The amount of magnese was found the highest in the latex of both species but calcium was found highest in leaves and bark of both species. Copper, chromium and lead were not found at all in latex but a very little amount of copper and lead were found in leaves and bark. The atomic absorption spectrophotometer was used to investigate the metals which were measured in the order of ppm.

Estimation of Reference Values for Cadmium, Cobalt, Chromium, Copper, Nickel, Lead, and Zinc in Brazilian Soils

2006 ◽  
Vol 37 (7-8) ◽  
pp. 945-959 ◽  
Author(s):  
Francisco de S. Fadigas ◽  
Nelson M. B. do Amaral Sobrinho ◽  
Nelson Mazur ◽  
Lúcia Helena Cunha dos Anjos
Keyword(s):  
Reference Values ◽  
Cobalt Chromium ◽  
Copper Nickel ◽  
Lead And Zinc ◽  
Brazilian Soils ◽  
Nickel Lead

Monitoring of Heavy Metals in the Water and Sediments of the Ganga River, India

1987 ◽  
Vol 19 (9) ◽  
pp. 107-117 ◽  
Author(s):  
Mohammad Ajmal ◽  
Mujahid A. Khan ◽  
Azhar A. Nomani
Keyword(s):  
Atomic Absorption Spectrophotometry ◽  
The Other ◽  
Sampling Station ◽  
Ganges River ◽  
Cobalt Chromium ◽  
Absorption Spectrophotometry ◽  
Lead And Zinc ◽  
Iron Manganese ◽  
The Ganges ◽  
Nickel Lead

The concentrations of cadmium, cobalt, chromium, copper, iron, manganese, nickel, lead and zinc in the water and sediments of the Ganges river were determine by Atomic Absorption Spectrophotometry in the year 1981. The respective ranges of concentrations of cadmium, cobalt, chromium, copper, iron, manganese, nickel, lead and zinc found in the water were ND-0.53, ND-4.89, 3.20–56.6, ND-27.57, 22.0–133.8, 35.0–93.0, ND-2.22, 2.0–5.6 and 7.37–67.36 µgl−1 and in the sediments were ND-3.48, 2.35–14.4, 9.0–83.16, 11.27–95.0, 2168.0–11624.8, 110.5–470.0, 3.45–28.80, 0.55–21.8 and 72.0–418.6 µgg−1. The data showed that there was considerable variation in the elements from one sampling station to the other. The sediments collected from different sampling stations were also analysed for pH, calcium carbonate, organic matter, potassium and phosphorus.

Investigation of Some Water Quality Parameters of Pond Water under Mymensingh Municipality

2015 ◽  
Vol 8 (1) ◽  
pp. 85-89
Author(s):  
F Zannat ◽  
MA Ali ◽  
MA Sattar
Keyword(s):  
Water Quality ◽  
Water Samples ◽  
Chemical Properties ◽  
Pond Water ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Urban Region ◽  
Mn Toxicity ◽  
Ph Values ◽  
Drinking Water Standard

A study was conducted to evaluate the water quality parameters of pond water at Mymensingh Urban region. The water samples were collected from 30 ponds located at Mymensingh Urban Region during August to October 2010. The chemical analyses of water samples included pH, EC, Na, K, Ca, S, Mn and As were done by standard methods. The chemical properties in pond water were found pH 6.68 to 7.14, EC 227 to 700 ?Scm-1, Na 15.57 to 36.00 ppm, K 3.83 to 16.16 ppm, Ca 2.01 to 7.29 ppm, S 1.61 to 4.67 ppm, Mn 0.33 to 0.684 ppm and As 0.0011 to 0.0059 ppm. The pH values of water samples revealed that water samples were acidic to slightly alkaline in nature. The EC value revealed that water samples were medium salinity except one sample and also good for irrigation. According to drinking water standard Mn toxicity was detected in pond water. Considering Na, Ca and S ions pond water was safe for irrigation and aquaculture. In case of K ion, all the samples were suitable for irrigation but unsuitable for aquaculture.J. Environ. Sci. & Natural Resources, 8(1): 85-89 2015

scholarly journals Critical importance of pH and collector type on the flotation of sphalerite and galena from a low-grade lead–zinc ore

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abdolrahim Foroutan ◽  
Majid Abbas Zadeh Haji Abadi ◽  
Yaser Kianinia ◽  
Mahdi Ghadiri
Keyword(s):  
Iron Ore ◽  
Low Grade ◽  
Zinc Recovery ◽  
Flotation Process ◽  
Ph Values ◽  
Lead And Zinc ◽  
Optimum Ph ◽  
Iron And Zinc ◽  
Lead Zinc ◽  
Zinc Concentrate

AbstractCollector type and pulp pH play an important role in the lead–zinc ore flotation process. In the current study, the effect of pulp pH and the collector type parameters on the galena and sphalerite flotation from a complex lead–zinc–iron ore was investigated. The ethyl xanthate and Aero 3418 collectors were used for lead flotation and Aero 3477 and amyl xanthate for zinc flotation. It was found that maximum lead grade could be achieved by using Aero 3418 as collector at pH 8. Also, iron and zinc recoveries and grades were increased in the lead concentrate at lower pH which caused zinc recovery reduction in the zinc concentrate and decrease the lead grade concentrate. Furthermore, the results showed that the maximum zinc grade and recovery of 42.9% and 76.7% were achieved at pH 6 in the presence of Aero 3477 as collector. For both collectors at pH 5, Zinc recovery was increased around 2–3%; however, the iron recovery was also increased at this pH which reduced the zinc concentrate quality. Finally, pH 8 and pH 6 were selected as optimum pH values for lead and zinc flotation circuits, respectively.

scholarly journals Shellfish Chitosan Potential in Wine Clarification

2021 ◽  
Vol 11 (10) ◽  
pp. 4417
Author(s):  
Veronica Vendramin ◽  
Gaia Spinato ◽  
Simone Vincenzi
Keyword(s):  
Molecular Structure ◽  
Chemical Properties ◽  
Allergic Reactions ◽  
Chitin Content ◽  
Deacetylation Degree ◽  
Physical Chemical ◽  
Similar Chemical ◽  
Fungal Chitosan ◽  
Significant Difference ◽  
Fish Industry

Chitosan is a chitin-derived fiber, extracted from the shellfish shells, a by-product of the fish industry, or from fungi grown in bioreactors. In oenology, it is used for the control of Brettanomyces spp., for the prevention of ferric, copper, and protein casse and for clarification. The International Organisation of Vine and Wine established the exclusive utilization of fungal chitosan to avoid the eventuality of allergic reactions. This work focuses on the differences between two chitosan categories, fungal and animal chitosan, characterizing several samples in terms of chitin content and degree of deacetylation. In addition, different acids were used to dissolve chitosans, and their effect on viscosity and on the efficacy in wine clarification were observed. The results demonstrated that even if fungal and animal chitosans shared similar chemical properties (deacetylation degree and chitin content), they showed different viscosity depending on their molecular weight but also on the acid used to dissolve them. A significant difference was discovered on their fining properties, as animal chitosans showed a faster and greater sedimentation compared to the fungal ones, independently from the acid used for their dissolution. This suggests that physical–chemical differences in the molecular structure occur between the two chitosan categories and that this significantly affects their technologic (oenological) properties.

Group III-Sb Metamorphic Buffer on Si for p-Channel all-III-V CMOS: Electrical Properties, Growth and Surface Defects

2015 ◽  
Vol 1790 ◽  
pp. 13-18
Author(s):  
Shun Sasaki ◽  
Shailesh Madisetti ◽  
Vadim Tokranov ◽  
Michael Yakimov ◽  
Makoto Hirayama ◽  
...  
Keyword(s):  
Surface Defects ◽  
Lattice Mismatch ◽  
Chemical Properties ◽  
Antiphase Domain ◽  
Hole Transport ◽  
Heteroepitaxial Growth ◽  
Group Iii ◽  
Similar Chemical ◽  
Unintentional Doping ◽  
P Type

ABSTRACTGroup III-Sb compound semiconductors are promising materials for future CMOS circuits. Especially, In1-xGaxSb is considered as a complimentary p-type channel material to n-type In1-xGaxAs MOSFET due to the superior hole transport properties and similar chemical properties in III-Sb’s to those of InGaAs. The heteroepitaxial growth of In1-xGaxSb on Si substrate has significant advantage for volume fabrication of III-V ICs. However large lattice mismatch between InGaSb and Si results in many growth-related defects (micro twins, threading dislocations and antiphase domain boundaries); these defects also act as deep acceptor levels. Accordingly, unintentional doping in InGaSb films causes additional scattering, increase junction leakages and affects the interface properties. In this paper, we studied the correlations between of defects and hole carrier densities in GaSb and strained In1-xGaxSb quantum well layers by using various designs of metamorphic superlattice buffers.

scholarly journals Development of multivariate calibration method for simultaneous determination of nickel, lead and zinc in tap water

2015 ◽  
Vol 18 (2) ◽  
pp. 145-151
Author(s):  
Chau Minh Huynh ◽  
Thu Du Ly ◽  
Thach Thai Pham ◽  
Tran Thi Bao Pham ◽  
Minh Khanh Duong ◽  
...  
Keyword(s):  
Simultaneous Determination ◽  
Absorption Spectra ◽  
Multivariate Calibration ◽  
Tap Water ◽  
Calibration Method ◽  
Calibration Model ◽  
Determination Of Nickel ◽  
Lead And Zinc ◽  
Nickel Lead

Conventional spectrophotometric methods for simultaneous determination of nickel, lead and zinc in forms of complexes with a reagent is not feasible due to the overlap of their absorption spectra. A multivariate calibration method was used to overcome this problem. In this study, the calibration model was constructed based on absorption spectra of 30 mixture standards in the range from 490 to 600 nm. Factors influencing experimental results such as amount of reagents, pH, and color development time were optimized. The standard calibration ranges for determination of nickel, lead and zinc were found at 0.5-5 ppm. The method was applied for determination of these ions in tap water samples at ppm level, with recoveries (and RSD) of nickel, lead and zinc were 103.3 % (3.0 %), 74.9 % (11.5 %) and 104.6 % (4.6 %), respectively.

Diamonds are Forever and Zirconium is for Submarines

2013 ◽  
Author(s):  
Lars Öhrström
Keyword(s):  
Transition Metals ◽  
Periodic Table ◽  
Chemical Properties ◽  
Pure Metal ◽  
Cubic Zirconia ◽  
Love Story ◽  
Zirconium Silicate ◽  
Similar Chemical ◽  
Engagement Rings

The appearance of a diamond engagement ring in the long and convoluted love story between Botswana’s First Lady Detective, Mma Ramotswe, and the owner and brilliant mechanic of Tlokweng Road Speedy Motors, Mr J. L. B. Matekoni, seems to signal an end to this particular sub-plot, stretching over several volumes of Alexander McCall Smith’s bestselling and original series of crime novels (that we met in Chapter 1). However, a slight problem involving cubic zirconia is discovered, and the story lingers on until the next book in the series. Similar names for elements and their compounds are a nuisance in chemistry, but oft en arise historically, and zirconium is just one such example. Apart from the pure metal we have zircon and zirconia, all three of which have important applications. Zircon is zirconium silicate, with the formula ZrSiO4, and cubic zirconia is a special form of zirconium dioxide, ZrO2. The latter, as you may have guessed, is an excellent diamond substitute in, among other applications, engagement rings. We are not going to dwell on the details of the element zirconium, but you should know that within the Periodic Table it is located in the large middle chunk called the transition metals. You have probably heard of its cousin titanium, immediately above it, and a sibling, hafnium, straight down the ladder. Why do I call them siblings? Because in the Periodic Table elements in the same column tend to have similar chemical properties. In particular, in the family of transition metals in the central section containing 27 elements—each with a number of properties in common—the two lower elements in each column tend to be the most similar. The similar chemical properties of zirconium and titanium means that we can usually find zirconium where we mine the much more plentiful titanium, and also that once we have separated the titanium from zirconium there will be a small quantity of hafnium trailing along—an impurity that is much harder to get rid of. The sleek jeweller in Gaborone will not care if his fake diamonds contain trace levels of HfO2 mixed with the ZrO2.

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