scholarly journals Chemical properties of complex aluminum ions

Author(s):  
Dennis Renato Manzano Vela

The objective of this research work was to study the synthesis of metallic salts and to analyze their properties. For this purpose, tests were carried out using basic and acid solutions. These tests allowed to identify that the reaction of aluminum in the presence of sulfuric acid is an exothermic reaction whose first stage is the formation of the tetrahydroxoaluminate (III) ion complex, a process in which a significant amount of heat is released from the system and a large amount of hydrogen gas for the oxidation of aluminum, a second stage in which sulfuric acid was added to neutralize the basicity of the solution transforming the complex into disulfate-aluminate (III), Then a third stage consisted in subjecting the solution in an ice bath to decrease the solubility of the complex and the formation of whitish crystals and finally the removal of excess crystals by washing with ethanol, these tests revealed the importance of excess sulfuric acid in the stabilization of the aluminate ion and the ease of the complex ion to bind to water molecules, thus determining important properties of the reaction as the type, orientation, solubility and the intermediates affected by the metal catalysis.

2018 ◽  
Vol 12 (3) ◽  
Author(s):  
O. O. Bondarchuk

Physical and chemical properties of cream multistep modes of ripening and fermentations are investigation and their role in the production of sour-cream butter is studied. The process of ripening of cream was carried out multistep, regimes were selected depending on seasonal changes in the composition of milk fat. For raw materials of the autumn-winter period, for the values of iodine number 29.1–34.5, the first stage of ripening was carried out at a temperature of 8°C for 2 hours, the second stage – at 21°C for 7 hours, the third stage – at 13°C for 10 hours. For raw of spring-summer period, for the values of iodine number 34.5–40.1, the first stage of ripening was carried out at 21°C for 6 hours, the second stage – at 13°C for 4 hours, the third stage – at 8°C for 8 hours. It has been established that individual modes of low-temperature cream preparation, taking into account seasonal changes in the composition of milk fat, make it possible to obtain cream before churning almost with the same indexes of effective viscosity. The content of the crystalline phase of milk fat under both temperature regimes was 38.7–40.1%, which is sufficient to obtain of proper consistency sour-cream butter. The content of diacetyl and volatile organic acids more depend on the level of fermentation of cream than on the technological regimes of ripening and seasonality of raw materials. It has been proved that an increase in the fermentation degree of cream promotes an increase in the acidity of plasma and the content of aroma-producing components in the butter, and, accordingly, affects the degree of the sour taste. It is recommended for the production of cultured butter to begin the cream when the acidity of the plasma reaches 60ºT, which ensures the formation of high sensorial characteristic of the finished product.


2009 ◽  
Vol 79-82 ◽  
pp. 1975-1978
Author(s):  
Oleg Figovsky ◽  
Sergey Usherenko

Now there is a motivation for creation of the materials possessing a considerable difference of physical and chemical properties in volume of composite materials 1 . Composite materials allow realizing a complex of various properties which cannot be realized simultaneously in mono material. The perspective in reception of a new smart nanomaterial is basically defined by possibilities which create processing conditions Choosing and manufacturing of fibers refers to the second stage of composite material reinforcement. Process of assemblage of a composite material from the details made at first two stages of process refers to the third stage. But at each stage of process of manufacturing of a composite material there are specific problems. The basic problem at composite material creation, as a rule, is essential contradictions between engineering solutions for various stages of process.


2021 ◽  
Vol 6 (2) ◽  
pp. 148-152
Author(s):  
Shah Md. Istiaque ◽  
Asif Iqbal Khan ◽  
Zaber Al Hassan ◽  
Sajjad Waheed

The research work titled “Smart Intrusion Detection System Comprised of Machine Learning and Deep Learning” was published in European Journal for Engineering and Technology Research (EJERS) online journal in the October edition where a smart IDS model was proposed. In this present work, validation of the IDS model is conducted. KDD Cup'99 intrusion detection dataset was used to build the IDS model. A unique method is incorporated to test the performance of the model. Here, training is conducted by using the KDD'99 dataset. But testing is done through the NSL-KDD dataset. Testing is conducted in three-stage. In the first stage, using generic 41 features the accuracy, sensitivity, and FPR of detecting attack was 95.240%, 93.103%, 1.936% respectively for Random Forest and for MLP it is 87.811%, 90.065%, and 15.168% respectively. In the second stage selective 15 features are used where accuracy, sensitivity, and FPR of detecting attack is 70.808%, 81.992%, 43.971% respectively for Random Forest and for MLP it is 67.637%, 87.660%, 54.266% respectively. In the third stage selective 22 features are used where accuracy, sensitivity, and FPR of detecting attack is 97.001%, 96.643%, 2.272% for Random Forest respectively and for MLP it is 85.442%, 82.350 and 10.472 respectively. Total 3,11,021 record is used for training and 22,544 record is used for testing purpose. The final accuracy, sensitivity and FPR of the model can be resulted as 95.24%, 70.808%, 96.988% for 41 features, 93.103%, 87.68%, 97.233% for 15 features, 1.936%, 43.97%, 3.36% for 22 features. Therefore, the IDS model is efficient and effective.


1974 ◽  
Vol 52 (18) ◽  
pp. 3235-3246 ◽  
Author(s):  
R. J. Routil ◽  
D. Barham

The formation of SrFe12O19 in the Fe2O3–Na2CO3–SrSO4 system was found to proceed through three stages, first an endothermic reaction between Fe2O3 and Na2CO3 to form Na2Fe2O4 and CO2, second an exothermic reaction of Na2Fe2O4 with SrSO4 to produce Na2SO4, Sr7Fe10O22, and SrFe12O19, third an exothermic reaction between Sr7Fe10O22 and Fe2O3 towards more SrFe12O19. The yield of SrFe12O19 depended on the molar ratio of the reactants and on temperature. Below 700 °C the formation did not proceed beyond the second stage. Samples prefired at 900–1200 °C contained SrFe12O19 in all cases when the original relative molar concentrations xFe2O3,yNa2CO3, and zSrSO4 satisfied the condition (x − y + z)/z > 5/7 or x/y > 5/7 ≥ x/z. Substitution of Na2CO3 in the reaction mixtures with equivalent amounts of NaOH or other precursors of Na2O did not affect the second and the third stage of the reaction and the final yield of SrFe12O19. On the ternary diagram of the Fe2O3–Na2O–SrSO4 system the SrFe12O19 region was represented by the area of a quadrilateral with the corner points located at the composition points 98-1-1, 1-1-98, 26-36-38, and 50-49-1 mole percent. The highest yields were obtained from the mixtures represented by the molar ratio 6Fe2O3:1 Na2O:1SrSO4. The hexagonal lattice parameters of SrFe12O19 were determined as a0 = 5.885 Å and c0 = 23.047 Å. X-Ray diffraction reflections of SrFe12O19 were indexed and reassignment of several indices in ASTM 7-276 for BaFe12O19 was suggested.


2015 ◽  
Vol 5 (3) ◽  
pp. 185-200
Author(s):  
Robert Z. Birdwell

Critics have argued that Elizabeth Gaskell's first novel, Mary Barton (1848), is split by a conflict between the modes of realism and romance. But the conflict does not render the novel incoherent, because Gaskell surpasses both modes through a utopian narrative that breaks with the conflict of form and gives coherence to the whole novel. Gaskell not only depicts what Thomas Carlyle called the ‘Condition of England’ in her work but also develops, through three stages, the utopia that will redeem this condition. The first stage is romantic nostalgia, a backward glance at Eden from the countryside surrounding Manchester. The second stage occurs in Manchester, as Gaskell mixes romance with a realistic mode, tracing a utopian drive toward death. The third stage is the utopian break with romantic and realistic accounts of the Condition of England and with the inadequate preceding conceptions of utopia. This third stage transforms narrative modes and figures a new mode of production.


2019 ◽  
Author(s):  
Lucy Armstrong ◽  
Lorna Hogg ◽  
Pamela Charlotte Jacobsen

The first stage of this project aims to identify assessment measures which include items on voice-hearing by way of a systematic review. The second stage is the development of a brief framework of categories of positive experiences of voice hearing, using a triangulated approach, drawing on views from both professionals and people with lived experience. The third stage will involve using the framework to identify any positve aspects of voice-hearing included in the voice hearing assessments identified in stage 1.


2021 ◽  
Vol 57 (4) ◽  
pp. 166-180
Author(s):  
Maria-Minodora Marin ◽  
Madalina Georgiana Albu Kaya ◽  
George Mihail Vlasceanu ◽  
Jana Ghitman ◽  
Ionut Cristian Radu ◽  
...  

Type II collagen has been perceived as the indispensable element and plays a crucial role in cartilage tissue engineering. Thus, materials based on type II collagen have drawn farther attention in both academic and research for developing new systems for the cartilage regeneration. The disadvantage of using type II collagen as a biomaterial for tissue repairing is its reduced biomechanical properties. This can be solved by physical, enzymatic or chemical cross-linking processes, which provide biomaterials with the required mechanical properties for medical applications. To enhance type II collagen properties, crosslinked collagen scaffolds with different cross-linking agents were prepared by freeze-drying technique. The present research work studied the synthesis of type II collagen biomaterials with and without crosslinking agents. Scaffolds morphology was observed by MicroCT, showing in all cases an appropriate microstructure for biological applications, and the mechanical studies were performed using compressive tests. DSC showed an increase in denaturation temperature with an increase in cross-linking agent concentration. FTIR suggested that the secondary structure of collagen is not affected after the cross-linking; supplementary, to confirm the characteristic triple-helix conformation of collagen, the CD investigation was performed. The results showed that the physical-chemical properties of type II collagen were improved by cross-linking treatments.


Author(s):  
Priyobrata Nath ◽  
Agnish Mukherjee ◽  
Sougata Mukherjee ◽  
Sabyasachi Banerjee ◽  
Samarpita Das ◽  
...  

: Isatin is an endogenous and a significant category of fused heterocyclic component, widely been a part of several potential biologically useful synthetics. Since its discovery, tons of research work has been conducted with respect to the synthesis, chemical properties, and biological and industrial applications. It contains indole nucleus having both lactam and keto moiety which while being a part of a molecular framework exerted several biological effects, viz.; antimicrobial, antitubercular, anticonvulsant, anticancer etc. Isatin derivatives are synthetically significant substrates, which can be utilized for the synthesis of huge diversified chemical entities of which few members emerged to be a drug. The reason for this review is to provide extensive information pertaining to the chemistry and its significance in altering several pathological states of isatin and its derivatives. A Structure Activity Relationships study thus developed through a gamut of scientific information indicates the importance of mostly electron withdrawing groups, halogens, nitro, alkoxy and to a minor extent groups with positive inductive effects, such as methyl at position 1, 5, 6 and 7 of isatin in alleviating several clinical conditions. It is also observed from the survey that the presence of two oxo groups at position 2 and 3 sometimes become insignificant as fusion with a heterocycle at those position resulted in a biologically relevant compound.


2021 ◽  
pp. 1-24
Author(s):  
Philipp Klar ◽  
Georg Northoff

The existential crisis of nihilism in schizophrenia has been reported since the early days of psychiatry. Taking first-person accounts concerning nihilistic experiences of both the self and the world as vantage point, we aim to develop a dynamic existential model of the pathological development of existential nihilism. Since the phenomenology of such a crisis is intrinsically subjective, we especially take the immediate and pre-reflective first-person perspective’s (FPP) experience (instead of objectified symptoms and diagnoses) of schizophrenia into consideration. The hereby developed existential model consists of 3 conceptualized stages that are nested into each other, which defines what we mean by existential. At the same time, the model intrinsically converges with the phenomenological concept of the self-world structure notable inside our existential framework. Regarding the 3 individual stages, we suggest that the onset or first stage of nihilistic pathogenesis is reflected by phenomenological solipsism, that is, a general disruption of the FPP experience. Paradigmatically, this initial disruption contains the well-known crisis of common sense in schizophrenia. The following second stage of epistemological solipsism negatively affects all possible perspectives of experience, that is, the first-, second-, and third-person perspectives of subjectivity. Therefore, within the second stage, solipsism expands from a disruption of immediate and pre-reflective experience (first stage) to a disruption of reflective experience and principal knowledge (second stage), as mirrored in abnormal epistemological limitations of principal knowledge. Finally, the experience of the annihilation of healthy self-consciousness into the ultimate collapse of the individual’s existence defines the third stage. The schizophrenic individual consequently loses her/his vital experience since the intentional structure of consciousness including any sense of reality breaks down. Such a descriptive-interpretative existential model of nihilism in schizophrenia may ultimately serve as input for future psychopathological investigations of nihilism in general, including, for instance, its manifestation in depression.


2002 ◽  
Vol 67 (3) ◽  
pp. 417-433 ◽  
Author(s):  
Kent V. Flannery

In Mesoamerica and the Near East, the emergence of the village seems to have involved two stages. In the first stage, individuals were distributed through a series of small circular-to-oval structures, accompanied by communal or “shared” storage features. In the second stage, nuclear families occupied substantial rectangular houses with private storage rooms. Over the last 30 years a wealth of data from the Near East, Egypt, the Trans-Caucasus, India, Africa, and the Southwest U.S. have enriched our understanding of this phenomenon. And in Mesoamerica and the Near East, evidence suggests that nuclear family households eventually gave way to a third stage, one featuring extended family households whose greater labor force made possible extensive multifaceted economies.


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