scholarly journals The Effect of Stoichiometry, Mg-Ca Distribution, and Iron, Manganese, and Zinc Impurities on the Dolomite Order Degree: A Theoretical Study

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 702
Author(s):  
Yuliya Zvir ◽  
Carlos Pimentel ◽  
Carlos M. Pina
Keyword(s):  
Partial Substitution ◽  
Ideal Stoichiometry ◽  
Order Degree ◽  
Diffraction Peaks ◽  
Intensity Ratios ◽  
Structure Lead ◽  
Different Origins ◽  
Iron Manganese ◽  
The Ideal

The determination of the degree of Mg-Ca order in the dolomite structure is crucial to better understand the process or processes leading to the formation of this mineral in nature. I01.5/I11.0 intensity ratios in the X-ray powder diffractograms are frequently measured to quantify dolomite cation order in dolomites. However, the intensity of diffraction peaks can be affected by factors other than the Mg-Ca distribution in the dolomite structure. The most relevant among these factors are (i) deviations from the ideal dolomite stoichiometry, and (ii) the partial substitution of Mg and Ca atoms by Fe, Mn, and Zn impurities. Using the VESTA software, we have constructed crystal structures and calculated I01.5/I11.0 ratios for dolomites with Mg:Ca ratios ranging from 0.5 to 1.5, and with Fe, Mn, and Zn contents up to 30%. Our results show that both deviations from dolomite ideal stoichiometry and the presence of impurities in its structure lead to a significant decrease in I01.5/I11.0 intensity ratios, an effect which must be considered when cation orders of natural dolomites from different origins are compared.

Metabolic response to temperature stress in the Colombian freshwater crab Neostrengeria macropa (H. Milne Edwards, 1853) (Decapoda: Brachyura: Pseudothelphusidae)

2021 ◽  
Author(s):  
David M Hudson
Keyword(s):  
Metabolic Response ◽  
Infrastructure Development ◽  
Predator Prey ◽  
Temperature Range ◽  
Indicator Group ◽  
Response To Temperature ◽  
Performance Results ◽  
The City ◽  
The Ideal

Abstract Freshwater crustaceans are distributed throughout the montane and lowland areas of Colombia, and are therefore a useful indicator group for how aquatic species will respond to climate change. As such, metabolic determination of physiological performance was evaluated for the Colombian pseudothelphusid crab, Neostrengeria macropa (H. Milne Edwards, 1853), over a temperature range inclusive of current temperatures and those predicted by future scenarios in the plateau around the city of Bogotá, namely from 8 °C to 30 °C. The performance results mostly aligned with previous exploratory behavioral determination of the ideal temperature range in the same species, although the metabolism increased at the highest temperature treatments, a point when exploratory behavior declined. These results indicate that this species of montane crab behaviorally compensates for increased thermal stress by decreasing its physical activity, which could have negative predator-prey consequences with changes to community structure as different species undergo climate-mediated geographic range shifts in the region. As this species is endemic to the plateau surrounding Bogotá, it also experiences a number of other stressors to its survival, including infrastructure development and invasive species.

scholarly journals Determination of Organic Compounds, Fulvic Acid, Humic Acid, and Humin in Peat and Sapropel Alkaline Extracts

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2995
Author(s):  
Laurynas Jarukas ◽  
Liudas Ivanauskas ◽  
Giedre Kasparaviciene ◽  
Juste Baranauskaite ◽  
Mindaugas Marksa ◽  
...  
Keyword(s):  
Humic Acid ◽  
Fulvic Acid ◽  
Humic Substances ◽  
Organic Compounds ◽  
Chemical Constituents ◽  
Acid Amide ◽  
Extraction Methods ◽  
Ultrasound Extraction ◽  
Different Origins

Black, brown, and light peat and sapropel were analyzed as natural sources of organic and humic substances. These specific substances are applicable in industry, agriculture, the environment, and biomedicine with well-known and novel approaches. Analysis of the organic compounds fulvic acid, humic acid, and humin in different peat and sapropel extracts from Lithuania was performed in this study. The dominant organic compound was bis(tert-butyldimethylsilyl) carbonate, which varied from 6.90% to 25.68% in peat extracts. The highest mass fraction of malonic acid amide was in the sapropel extract; it varied from 12.44% to 26.84%. Significant amounts of acetohydroxamic, lactic, and glycolic acid derivatives were identified in peat and sapropel extracts. Comparing the two extraction methods, it was concluded that active maceration was more efficient than ultrasound extraction in yielding higher amounts of organic compounds. The highest amounts of fulvic acid (1%) and humic acid and humin (15.3%) were determined in pure brown peat samples. This research on humic substances is useful to characterize the peat of different origins, to develop possible aspects of standardization, and to describe potential of the chemical constituents.

Theoretical determination of the structures of CaSiO3 perovskites

2006 ◽  
Vol 62 (6) ◽  
pp. 1025-1030 ◽  
Author(s):  
Razvan Caracas ◽  
Renata M. Wentzcovitch
Keyword(s):  
Crystal Structure ◽  
Experimental Data ◽  
Density Functional Theory ◽  
Density Functional ◽  
Theoretical Determination ◽  
Functional Theory ◽  
Starting Point ◽  
Atomic Coordinates ◽  
The Ideal

Density functional theory is used to determine the possible crystal structure of the CaSiO3 perovskites and their evolution under pressure. The ideal cubic perovskite is considered as a starting point for studying several possible lower-symmetry distorted structures. The theoretical lattice parameters and the atomic coordinates for all the structures are determined, and the results are discussed with respect to experimental data.

scholarly journals Methods to Form the Pedagogical Culture of Parents in the Educational System of the School

2020 ◽  
pp. 38-42
Author(s):  
Galina Veniaminovna Sorokoumova ◽  
Anastasiia Olegovna Bespalova
Keyword(s):  
Common Sense ◽  
Educational System ◽  
High Efficiency ◽  
Educational Institution ◽  
Parenting Skills ◽  
The Family ◽  
The Impact ◽  
The Ideal ◽  
Pedagogical Culture

The article deals with the concept of pedagogical culture of parents, the goals of development of pedagogical culture of parents and methods of formation and improvement of the level of pedagogical culture of parents. The paper focuses on the tasks of interaction between an educational institution and the family in the upbringing of children. Methods of study. To study the possibility of forming a pedagogical culture of parents, we used a questionnaire to survey the needs of parents to interact with the educational institution and the interest of teachers in working with the family, the «Ideas about the ideal parent» method by R. V. Ovcharova, Y.A. Degtyareva, «Family Biofield» inquirer by V. V. Boyko and «Determination of parenting skills» questionnaire by O.L. Zvereva. Results of the study. The article shows the results of the impact of the program, which includes a seminar using the case technology «pedagogical culture of parents» and parent training based on the program «education based on common sense» on the formation of the pedagogical culture of parents. Conclusion. The results of the study proved the possibility of purposeful formation of the pedagogical culture of parents in the educational system of the school and the high efficiency of practice – and personality-oriented methods of such work, and also showed greater competence and awareness among parents and kindergarten teachers in the education of children.

scholarly journals ARAH BARU KAJIAN TAFSIR: KAJIAN METODOLOGI PENELITIAN AKSIN WIJAYA DALAM KARYANYA SEJARAH KENABIAN PERSPEKTIF TAFSIR NUZULI MUHAMMAD IZZAT DARWAZAH

QOF ◽  
2018 ◽  
Vol 2 (2) ◽  
pp. 161-174
Author(s):  
Cholid Ma'arif
Keyword(s):  
Research Methods ◽  
Family Life ◽  
Research Methodology ◽  
Comparative Research ◽  
The People ◽  
Four Books ◽  
Interpretation Method ◽  
The Ideal

Abstrak This paper will explore aspects of research methodology of exegesis written by Aksin Wijaya related to methods nuzuli ala Muhammad Izzat Darwazah. For that, the focus of this discussion is the methodology of his research in his own book of under title Sejarah Kenabian Dalam Perspektif Tafsir Nuzuli Muhammad Izzat Darwazah, finding out how people review mufassir. Specifically, the methodical determination of the previous his experienced has moved soon of orientation from the critical to the descriptive while facing of four books, namely: Tafsir al Hadith, 'Ashr al Nabiy wa Biatuhu Qabla al Bi'tsah, Sirah al Rasul; Suwar Muqtabasah min al Qur'an, and ad Dustur al Qur'an fi Su'uni al Hayat works of thinkers and historians. From his reading, he at least analyzes his views into two important parts, namely; 1) the interpretation method of nuzuli and the ideal concept it contains, 2) it then draws it into the realm of pre-Islamic, personal and family life of the prophet Muhammad, to the condition of the people of prophetic era through the perspective of nuzuli Izzat Darwazah exegesis. According to the reviewer, there are other research elements in writing the work of the exegesis, namely some models of research methods of interpretation at once, such as: comparative research, character research, and thematic-nuzuli research. Whereas although placed more as an overview of nuzuli interpretation, at least he invites readers, especially in Indonesia to re-read the tafsir nuzuli treasury and see which is as worthy to be developed in the turats of Islam Nusantara. Abstrak Tulisan ini hendak menelusuri aspek metodologi penelitian tafsir yang dilakukan oleh Dr. Aksin Wijaya terkait metode nuzuli ala Muhammad Izzat Darwazah. Untuk itu, fokus dari pembahasan ini adalah tentang metodologi penelitiannya dalam buku berjudul Sejarah Kenabian Dalam Perspektif Tafsir Nuzuli Muhammad Izzat Darwazah untuk mengetahui bagaimana orang mengkaji mufassir. Dimana secara khusus mulai penentuan metodis dari sebelumnya ia mengalami pergeseran orientasi dari kritis ke deskriptif dalam menghadapi empat kitab hasil perburuannya, yaitu: Tafsir al Hadits, ‘Ashr al Nabiy wa Biatuhu Qabla al Bi’tsah, Sirah al Rasul; Suwar Muqtabasah min al Qur’an, dan ad Dustur al Qur’an fi Su’uni al Hayat karya tokoh pemikir dan sejarawan. Dari pembacaannya tersebut, ia setidaknya menganalisa pandangannya menjadi dua bagian penting, yaitu; 1) metode tafsir nuzuli dan konsep ideal yang dikandungnya, 2) kemudian ia menariknya ke ranah kehidupan masyarakat pra-islam, pribadi dan keluarga nabi Muhammad saw, hingga kondisi masyarakat era kenabian melalui perspektif tafsir nuzuli Izzat Darwazah. Pun demikian, menurut penulis ada unsur penelitian lain dalam penulisan karya Aksin tersebut, yaitu beberapa model metode penelitian tafsir sekaligus, seperti: penelitian perbandingan, penelitian tokoh, dan penelitian tematik-nuzuli. Dimana walaupun diletakkan lebih sebagai gambaran umum tafsir nuzuli, setidaknya ia mengajak pembaca khususnya di Indonesia untuk meneelaah kembali khazanah tafsir nuzuli dan memandang mana yang sekira layak untuk dikembangkan dalam turats Islam ke-Indonesia-an.

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