scholarly journals Influence of Physicochemical Properties and Parent Material on Chromium Fractionation in Soils

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1073
Author(s):  
Claudia Campillo-Cora ◽  
Laura Rodríguez-González ◽  
Manuel Arias-Estévez ◽  
David Fernández-Calviño ◽  
Diego Soto-Gómez
Keyword(s):  
Physicochemical Properties ◽  
Contaminated Soils ◽  
Research Work ◽  
Parent Material ◽  
The Other ◽  
Oxidation States ◽  
Diethylenetriaminepentaacetic Acid ◽  
Remediation Strategies ◽  
Exchangeable Aluminum ◽  
Efficient Extraction

Chromium is an element that possess several oxidation states and can easily pass from one to another, so its behavior in soils is very complex. For this reason, determining its fate in the environment can be difficult. In this research work we tried to determine which factors affect the chromium fractionation in natural soils, conditioning chromium mobility. We paid special attention to the parent material. For this purpose, extraction experiments were carried out on spiked soils incubated for 50–60 days, using H2O, CaCl2 and diethylenetriaminepentaacetic acid (DTPA). The most efficient extraction rate in all soils was achieved using water, followed by CaCl2 and DTPA. We obtained models with an adjusted R2 of 0.8097, 0.8471 and 0.7509 for the H2O Cr, CaCl2 Cr and DTPA Cr respectively. All models were influenced by the amount of chromium added and the parent material: amphibolite and granite influenced the amount of H2O Cr extracted, and schist affected the other two fractions (CaCl2 and DTPA). Soil texture also played an important role in the chromium extraction, as well as the amounts of exchangeable aluminum and magnesium, and the bioavailable phosphorus. We concluded that it is possible to make relatively accurate predictions of the behavior of the different Cr fractions studied, so that optimized remediation strategies for chromium-contaminated soils can be designed on the basis of a physicochemical soil characterization.

Response to Jean-Pierre Chretien

1990 ◽  
Vol 19 (1) ◽  
pp. 41-41
Author(s):  
René Lemarchand
Keyword(s):  
Research Work ◽  
The Other ◽  
Other Hand ◽  
Excellent Work ◽  
The One

My apologies to Mr. Chrétien and to your readers for “developing some simplistic formulas on Burundi” in my quest for “media success.” No such simplistic formulas enter his criticism of my Congressional testimony. On the one hand, I am taken to task for not conceding that my interpretation of the Hutu-Tutsi conflict as a recent phenomenon is the product of Chrétien’s “patient research work” over the last quarter of a century; on the other hand, “some very similar analysis” had appeared in my “excellent work of 1970,” which came out long before Mr. Chrétien embarked on his patient research! Try to figure that one out if you can.

scholarly journals GENOTOXIC AND CARCINOGENIC STUDIES OF NORGESTREL IN DROSOPHILA MELANOGASTER

2018 ◽  
Vol 11 (10) ◽  
pp. 372
Author(s):  
Abou-eisha A ◽  
Adel E El-din
Keyword(s):  
Somatic Mutation ◽  
Cellular Proliferation ◽  
Research Work ◽  
The Body ◽  
The Other ◽  
Direct Stimulation ◽  
Carcinogenic Activity ◽  
Genetic Examination ◽  
First Time

Objective: The aim of this study was to investigate, for the first time, the possible in vivo genotoxic and carcinogenic activity associated with exposure to norgestrel (NGT) drug through employing the very recently established and adjusted genotoxic and tumorigenic methods in Drosophila melanogaster.Methods: Two in vivo genotoxic test systems were used; one detects the somatic mutation and recombination effects (somatic mutation and recombination test [SMART] wing-spot test) and the other detects the primary DNA damage (the comet test) in the body cells of D. melanogaster. On the other hand, the warts (wts)-based SMART assay is a vital genetic examination in Drosophila used to identify and characterize cancer potential of compounds.Results: Four experimental doses of NGT were used (ranging from 0.24 μM to 16 μM). NGT was found to be non-genotoxic at all tested concentrations even at the highest dose level 16 μM and failed to increase the frequency of tumors in the somatic cells of D. melanogaster.Conclusion: Our results strengthen the hypothesis that steroidal drugs might act through a non-genotoxic carcinogen mechanism where the carcinogenic properties occur by direct stimulation of cellular proliferation through a steroid receptor-mediated mechanism. In addition, the results obtained in this research work may contribute to highlighting the importance of NGT as a potent neuroprotective antioxidant drug.

scholarly journals Selenium– and tellurium–halogen reagents

2018 ◽  
Vol 3 (12) ◽  
Author(s):  
Tristram Chivers ◽  
Risto S. Laitinen
Keyword(s):  
Oxidation State ◽  
Halogen Bond ◽  
The Other ◽  
Oxidation States ◽  
Alkyl Aryl ◽  
Organic Selenium ◽  
Formal Oxidation State ◽  
Wide Range ◽  
Inorganic And Organic

Abstract Selenium and tellurium form binary halides in which the chalcogen can be in formal oxidation states (IV), (II) or (I). They are versatile reagents for the preparation of a wide range of inorganic and organic selenium and tellurium compounds taking advantage of the reactivity of the chalcogen–halogen bond. With the exception of the tetrafluorides, the tetrahalides are either commercially available or readily prepared. On the other hand, the low-valent species, EX2 (E = Se, Te; X = Cl, Br) and E2X2 (E = Se, Te; X = Cl, Br) are unstable with respect to disproportionation and must be used as in situ reagents. Organoselenium and tellurium halides are well-known in oxidation states (IV) and (II), as exemplified by REX3, R2EX2 and REX (R = alkyl, aryl; E = Se, Te; X = F, Cl, Br, I); mixed-valent (IV/II) compounds of the type RTeX2TeR are also known. This chapter surveys the availability and/or preparative methods for these widely used reagents followed by examples of their applications in synthetic inorganic and organic selenium and tellurium chemistry. For both the binary halides and their organic derivatives, the discussion is subdivided according to the formal oxidation state of the chalcogen.

scholarly journals The Literary «Ekphrasis» of Castel Nuovo: A Contribution to Value the Cultural Identity of the Ideal City Government, Promoted by Aristocratic Courts and Civil Administrations in the XIV Century

2014 ◽  
Vol 11 ◽  
pp. 483-488
Author(s):  
Sara Cipolla
Keyword(s):  
Cultural Identity ◽  
Research Work ◽  
Italian Literature ◽  
City Government ◽  
The Other ◽  
The Political ◽  
Ripe Fruit ◽  
Surface Projection ◽  
Medieval Italian Literature ◽  
The Ideal

The research work concerns the development in the Italian literature of the French theme of Neuf Preux, and Particularly Took into account a crown of sonnets of nine famous men linked to an alleged cycle of paintings attributed to Giotto's in the palace of Castel Nuovo in Naples. The survey highlighted how in medieval Italian literature, beyond the more or less explicit recovery of the French literary tradition, occupies a prominent place the function that these poems take in the view of the literature of the time. The survey actually shows the two faces of the series of famous heroes, which on one hand is the mouthpiece of the political ideals and civil inspired by the courteous and Roman antiquities, on the other hand appears to be ripe fruit of a didactic poem in which the adherence to the motto of "ut pictura poesis" become as a kind of surface projection of images.

scholarly journals Co-existence of two plasma phases in solar and AGN coronas

1998 ◽  
pp. 43-53
Author(s):  
A. Kubicela ◽  
J. Arsenijevic ◽  
L.C. Popovic ◽  
N. Trajkovic ◽  
E. Bon
Keyword(s):  
Solar Corona ◽  
Active Galactic Nuclei ◽  
Research Work ◽  
Neutral Hydrogen ◽  
Galactic Nuclei ◽  
Theoretical Explanation ◽  
The Other ◽  
Solar Photosphere ◽  
Hydrogen Lines ◽  
Hot Corona

Here we have juxtaposed two distant cosmic locations of the Sun and AGN where neutral hydrogen appears in a close connection with hot coronas. Besides the solar photosphere, chromosphere and prominences where the presence of neutral hydrogen is well established, its emission quite high in hot solar corona is still puzzling. Some of earlier observations where H? emission in solar corona was detected in eclipse and in daily coronagraphic observations are reviewed. A proper theoretical explanation of this cold chromospheric-type emission in the hot corona does not exist yet. On the other side, a similar emission of hydrogen lines is present in Active Galactic Nuclei (AGNs). Much research work is currently being done in this field. We outline some of the concepts of the AGN structure prevailing in the astrophysics today.

scholarly journals A review of Nadi Parikshan in various Ayurvedic Samhita with its clinical methods

2020 ◽  
Vol 4 (06) ◽  
Author(s):  
Pooja Babaso Kamble
Keyword(s):  
Diagnostic Tool ◽  
Common Factor ◽  
Research Work ◽  
Cost Effective ◽  
The Other ◽  
Diagnostic Tools ◽  
Healthy Individuals ◽  
Medical Field ◽  
Clinical Methods ◽  
Time Region

Nadi Pariksha is the most effective diagnostic tool known in the medical field. It is cost effective,  accurate,  safe,  and gives quick results. We can conduct Nadi Pariksha on healthy individuals as well as all patients irrespective of stage of the disease also,  and even pregnant woman,  children,  elderly can undergo without any harm or side effects. However,  this technique is not being widely practised at present,  because of lack of training,  practise and knowledge about it in the present day among Ayurveda vaidyas. An iconic factor for identification of a physician,  irrespective of the time,  Region,  Nadi Pariksha can be highlighted as a common factor or even System of Medicine or Civilization of the known world. Thus,  we can perceive that Nadi Pariksha or the pulse examination remains as an effective diagnostic tool since ages. Nadi Pariksha was not been discussed among the Brihatrayees of Ayurveda. Acharya Sharangdhara was the first to document in the doctrines of Ayurveda. Thus Acharya Sharangdhara is considered as ‘The Founder of Nadi Pariksha’in Ayurveda. Nadi Pariksha was titled under the Pancha-Nidana by Acharya Sharangdhara and Ashta Sthana Pariksha by Acharya Yogaratnakara. It was the Foremost among all the other diagnostic tools mentioned by him. Later Acharyas like Acharya Bhava Mishra,  Acharya Yogaratnakara,  Acharya Basavaraja,  Acharya Kanada Maharishi,  and Acharya Ravana have contributed in giving more descriptions and importance. In the recent days Dr. Vasant lad and Dr. Sarvadeva Upadhaya’s research work interest and scope of Nadi Pariksha.

scholarly journals A CONTRIBUTION TO THE HYDROCHEMISTRY AND WATER TYPOLOGY OF THE AMAZON RIVER AND ITS TRIBUTARIES

2019 ◽  
Vol 20 (72) ◽  
pp. 360-374 ◽  
Author(s):  
Maria do Socorro Rocha da Silva ◽  
Eduardo Antonio Ríos-Villamizar ◽  
Hillândia Brandão da Cunha ◽  
Sebastião Átila Fonseca Miranda ◽  
Sávio José Filgueiras Ferreira ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Physicochemical Properties ◽  
Amazon Basin ◽  
The Other ◽  
Amazon River ◽  
Left Bank ◽  
Guiana Shield ◽  
Ionic Charge ◽  
Physical Chemical ◽  
Geological Diversity

The geological diversity of the Amazon Basin, as well as the pluvial regime, influences the characteristics of the waters. To know the water types of the rivers of the Amazon basin, 288 superficial water samples were collected, 94 of them along the Amazon River and 194 in their tributaries, from March 2009 to September 2012. The physical, chemical, and physicochemical properties were analyzed. Rivers with pH between 6.5 and 7.6 and electrical conductivity (40.00 - 80.00 μS cm-1) are water bodies that are influenced by the Andean region (e.g., the Amazon River and some of its right bank tributaries). On the other hand, the rivers with pH in the range of 3.5 to 5.5 and conductivity <30.00 μS cm-1, which are Amazon River’s left bank tributaries, reflect the characteristics of the Guiana Shield. The rivers with pH (6.0 to 7.0), low ionic charge, and conductivity <40.0 μS cm-1, such as the lower Amazon River’s right bank tributaries (Tapajos and Xingu) which are influenced by the Central Brazilian Shield, and also the middle/upper Amazon River’s right bank tributaries (Tefé, Coari and Jutaí).

scholarly journals The Politics of Masculinity in Tony Gould’s Imperial Warriors: Britain and the Gurkhas

2021 ◽  
pp. 34-42
Author(s):  
Ram Prasad Rai
Keyword(s):  
Qualitative Research ◽  
Hegemonic Masculinity ◽  
Research Work ◽  
The Other ◽  
Main Concern ◽  
Journal Articles ◽  
Related Area ◽  
The World ◽  
The Future ◽  
Second World

The main concern of this paper is to study on masculinity and more importantly the hyper masculinity of the Gurkhas in Imperial Warriors: Britain and the Gurkhas by Tony Gould. The writer describes the courage with discipline and dedication, the Gurkhas had while fighting for Nepal, their homeland during the Anglo-Nepal War (1814-1816) and for Britain in the First and Second World Wars, following the other wars and confrontations in many parts of the world. Despite a lot of hardships and pain in wars, they never showed their back to the enemies, but kept Britain’s imperial image always high with victories. They received Victoria Crosses along with other bravery medals. As a masculinity, the hegemonic masculinity is obviously present in the book since the high ranked British Officers are in the position to lead the Gurkha soldiers. However, the masculinity here is associated with the extreme level of bravery and that is the hyper-masculinity of the Gurkhas. Since this is a qualitative research work, the researcher has consulted various books, reviews and journal articles related to the Gurkhas. It is a new concept in the study of the Gurkhas in the particular book by Gould. So, it will certainly be a new insight for the future researchers in the related area.

scholarly journals ECONOMICS OF NITROGEN USE IN DAIRYING

1982 ◽  
pp. 70-75
Author(s):  
D.A.L. Buxton
Keyword(s):  
New Zealand ◽  
Research Work ◽  
Dairy Farms ◽  
Early Spring ◽  
The Other ◽  
Stocking Rate ◽  
Nitrogen Use

During the last 10 to 15 years, the use of fertiliser N at low rates on New Zealand dairy farms has become more popular. There are many ways in which fertiliser N can be used to increase pasture and milkfat production. Five of those options are analysed, viz. I. High rates of N. 2. Bridging a spring feed deficit. 3. Increasing stocking rate. 4. Earlier calving. 5. More cow condition. Research work is finding the best times and rates of application of N. The extra pasture produced must then be utilised to maximise milkfat responses. Trials have shown that the use of high rates of fertiliser N ( > 80 kg N/ha) is unlikely to be profitable on N.Z. dairy farms. N used to enable more cows to be wintered, and then milked in early spring, appears to be very profitable, due to better utilisation of later spring-autumn pasture growth. The other three options are also profitable, but the increase in total farm milkfat production is only 3 to 4%. The options need to be tested more thoroughly with models and grazing experiments.

scholarly journals Stock Price Prediction Using Deep Learning Models

2021 ◽  
Author(s):  
Jaydip Sen ◽  
Sidra Mehtab ◽  
Gourab Nath
Keyword(s):  
Deep Learning ◽  
Stock Prices ◽  
Stock Price ◽  
Regression Models ◽  
Research Work ◽  
The Other ◽  
Learning Models ◽  
Stock Price Prediction ◽  
Price Prediction ◽  
Other Hand

Prediction of future movement of stock prices has been a subject matter of many research work. On one hand, we have proponents of the Efficient Market Hypothesis who claim that stock prices cannot be predicted, on the other hand, there are propositions illustrating that, if appropriately modeled, stock prices can be predicted with a high level of accuracy. There is also a gamut of literature on technical analysis of stock prices where the objective is to identify patterns in stock price movements and profit from it. In this work, we propose a hybrid approach for stock price prediction using five deep learning-based regression models. We select the NIFTY 50 index values of the National Stock Exchange (NSE) of India, over a period of December 29, 2014 to July 31, 2020. Based on the NIFTY data during December 29, 2014 to December 28, 2018, we build two regression models using <i>convolutional neural networks</i> (CNNs), and three regression models using <i>long-and-short-term memory</i> (LSTM) networks for predicting the <i>open</i> values of the NIFTY 50 index records for the period December 31, 2018 to July 31, 2020. We adopted a multi-step prediction technique with <i>walk-forward validation</i>. The parameters of the five deep learning models are optimized using the grid-search technique so that the validation losses of the models stabilize with an increasing number of epochs in the model training, and the training and validation accuracies converge. Extensive results are presented on various metrics for all the proposed regression models. The results indicate that while both CNN and LSTM-based regression models are very accurate in forecasting the NIFTY 50 <i>open</i> values, the CNN model that previous one week’s data as the input is the fastest in its execution. On the other hand, the encoder-decoder convolutional LSTM model uses the previous two weeks’ data as the input is found to be the most accurate in its forecasting results.

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