scholarly journals The preparation of oxygen by electrolysis of baryta

Author(s):  
Eric M. Stoddart ◽  
Frederick George Donnan

Morley, in his classical researches, pointed out that various impurities were present in the gases produced by electrolysis of sulphuric acid and potassium hydroxide solutions. Using the latter method, Lord Rayleigh, by addition of a small quantity of baryta, attempted to minimize the amount of hydrocarbons present in the hydrogen as impurity, derived from the carbonate present in the alkali. Baker pointed out that the action of baryta on potassium carbonate is a reversible one, particularly in the presence of such a large excess of potash, and concluded that Rayleigh's precaution might not be particularly effective. Baker recommended the electrolysis of pure barium hydroxide solution, in which barium carbonate is insoluble, and which consequently must give hydrogen tree from hydrocarbons. He also noted that, with the use of pure baryta solution, the oxygen is apparently free from ozone and hydrogen peroxide. It is to be noted that Baker gave no details concerning the shape and material of his electrodes, or of the currents employed in the electrolysis. The method of electrolysing baryta, using nickel electrodes has become a standard method of preparing small quantities of pure oxygen. The present author has employed the apparatus shown in fig. 1 for this purpose during the past few months. The apparatus consists of two vessels, A and B, constructed from 1-inch internal diameter tubing, carrying nickel electrodes, the upper ends of which are welded to platinum wires sealed through the glass, the seals being sufficiently strong to allow currents up to 2 amperes to pass without cracking the glass. The use of nickel is justified owing to its low hydrogen and oxygen over-voltages. The electrodes are constructed from 18 S. W. O. pure nickel wire, 3 feet of which is coiled up as shown. These electrodes have a fairly large surface area—approximately 34 sq cm. The baryta solution was saturated at room temperature and a layer of pure barium hydroxide was allowed to settle on the bottom of the outer jar. The electrolysis was carried out, using a current of 1 ampere, which kept the temperature of the solution at about 60°C. The oxygen was used in experiments, and was found at first to be highly satisfactory.

Author(s):  
R. Varughese ◽  
S. W. Thompson ◽  
P. R. Howell

Ever since Habraken and Economopoulos first employed the term granular bainite to classify certain unconventional transformation products in continuously cooled steels, the term has been widely accepted and used, despite the lack of a clear consensus as to the detailed nature of the transformation products which constitute granular bainite. This paper presents the preliminary results of a TEM investigation of an 0.04 wt% C, copper-containing steel (designated HSLA-100). It is suggested that the term granular ferrite rather than granular bainite is a more accurate description of this multiphase reaction product.Figure 1 is a light micrograph of a sample which had been air-cooled from 900°C to room temperature. The microstructure is typical of that which has been termed granular bainite in the past and appears to consist of equiaxed ferritic grains together with other minor transformation products. In order to examine these structures in more detail, both continuously cooled and isothermally transformed and quenched materials have been examined with TEM. Granular bainite has been found in virtually all samples.


1961 ◽  
Vol 06 (03) ◽  
pp. 435-444 ◽  
Author(s):  
Ricardo H. Landaburu ◽  
Walter H. Seegers

SummaryAn attempt was made to obtain Ac-globulin from bovine plasma. The concentrates contain mostly protein, and phosphorus is also present. The stability characteristics vary from one preparation to another, but in general there was no loss before 1 month in a deep freeze or before 1 week in an icebox, or before 5 hours at room temperature. Reducing agents destroy the activity rapidly. S-acetylmercaptosuccinic anhydride is an effective stabilizing agent. Greatest stability was at pH 6.0.In the purification bovine plasma is adsorbed with barium carbonate and diluted 6-fold with water. Protein is removed at pH 6.0 and the Ac-globulin is precipitated at pH 5.0. Rivanol and alcohol fractionation is followed by chromatography on Amberlite IRC-50 or DEAE-cellulose. The final product is obtained by isoelectric precipitation.


2017 ◽  
pp. 5-21 ◽  
Author(s):  
E. Yasin

The article is devoted to major events in the history of the post-Soviet economy, their influence on forming and development of modern Russia. The author considers stages of restructuring, market reforms, transformational crisis, and recovery growth (1999-2011), as well as a current period which started in2011 and is experiencing serious problems. The present situation is analyzed, four possible scenarios are put forward for Russia: “inertia”, “mobilization”, “decisive leap”, “gradual democratic development”. More than 30 experts were questioned in the process of working out the scenarios.


Author(s):  
Josh Kun

Ever since the 1968 student movements and the events surrounding the Tlatelolco massacre, Mexico City rock bands have openly engaged with the intersection of music and memory. Their songs offer audiences a medium through which to come to terms with the events of the past as a means of praising a broken world, to borrow the poet Adam Zagajewski’s phrase. Contemporary songs such as Saúl Hernández’s “Fuerte” are a twenty-first-century voicing of the ceaseless revolutionary spirit that John Gibler has called “Mexico unconquered,” a current of rebellion and social hunger for justice that runs in the veins of Mexican history. They are the latest additions to what we might think about as “the Mexico unconquered songbook”: musical critiques of impunity and state violence that are rooted in the weaponry of memory, refusing to focus solely on the present and instead making connections with the political past. What Octavio Paz described as a “swash of blood” that swept across “the international subculture of the young” during the events in Tlatelolco Plaza on October 2, 1968, now becomes a refrain of musical memory and political consciousness that extends across eras and generations. That famous phrase of Paz’s is a reminder that these most recent Mexican musical interventions, these most recent formations of a Mexican subculture of the young, maintain a historically tested relationship to blood, death, loss, and violence.


Synthesis ◽  
2020 ◽  
Author(s):  
Narendra R. Chaubey ◽  
Anant R. Kapdi ◽  
Biswanath Maity

AbstractOrganophotocatalytic C–H bond functionalization has attracted a lot of attention in the past several years due to the possibility of catalyzing reactions in a metal- and peroxide-free environment. Continuing on these lines, an organophotoredox-catalyzed C–H functionalization of imidazo[1,2-a]pyridines and related heterocycles with bromomalonates under mild conditions is reported, providing excellent yields of the products at room temperature. This is the first report involving malonates as coupling partners leading to the synthesis of a range of functionalized products including total synthesis of zolpidem, a sedative­-hypnotic drug molecule.


2021 ◽  
Vol 10 (11) ◽  
pp. 2457
Author(s):  
Birgit J. Gerecke ◽  
Rolf Engberding

Noncompaction cardiomyopathy (NCCM) has gained increasing attention over the past twenty years, but in daily clinical practice NCCM is still rarely considered. So far, there are no generally accepted diagnostic criteria and some groups even refuse to acknowledge it as a distinct cardiomyopathy, and grade it as a variant of dilated cardiomyopathy or a morphological trait of different conditions. A wide range of morphological variants have been observed even in healthy persons, suggesting that pathologic remodeling and physiologic adaptation have to be differentiated in cases where this spongy myocardial pattern is encountered. Recent studies have uncovered numerous new pathogenetic and pathophysiologic aspects of this elusive cardiomyopathy, but a current summary and evaluation of clinical patient management are still lacking, especially to avoid mis- and overdiagnosis. Addressing this issue, this article provides an up to date overview of the current knowledge in classification, pathogenesis, pathophysiology, epidemiology, clinical manifestations and diagnostic evaluation, including genetic testing, treatment and prognosis of NCCM.


Author(s):  
Sally McManus ◽  
Paul E. Bebbington ◽  
Leonie Tanczer ◽  
Sara Scott ◽  
Louise M. Howard

Abstract Purpose Threatening or obscene messaging is repeated, unwanted texts, emails, letters or cards experienced by the recipient as threatening or obscene, and causing fear, alarm or distress. It is rarely examined as an aspect of intimate partner violence. We describe the prevalence of exposure to threatening/obscene messaging from a current or ex-partner; characteristics of victims; and associations with other forms of violence and abuse, mental disorder, self-harm, and suicidality. Methods Cross-sectional probability-sample survey of the general population in England aged 16 + . Multivariable regression modelling tested associations between receipt of threatening/obscene messaging and current common mental disorder, past-year self-harm and suicidality. Results Threatening/obscene messages were received from a current/ex-partner by 6.6% (95%CI: 5.9–7.3) of adults who had been in a relationship; 1.7% received these in the past year. Victims were more likely to be female, under 35, single or divorced, socioeconomically disadvantaged, and to have experienced other forms of sexual and partner violence and abuse. Those who received threatening/obscene messages in the past year were more likely to experience common mental disorder (adjusted odds ratio 1.89; 1.01–3.55), self-harm (2.31; 1.00–5.33), and suicidal thoughts (2.00; 1.06–3.78). Conclusion Threatening/obscene messaging commonly occurs in the context of intimate partner violence. While often occurring alongside sexual and physical violence, messaging has an additional association with mental disorder and suicidality. Routine enquiry in service settings concerning safety, including those working with people who have escaped domestic violence, should ask about ongoing contact from previous as well as current partners. This should include asking about messaging, as well as other forms of potentially technology-enabled abuse which may become increasingly common.


1996 ◽  
Vol 452 ◽  
Author(s):  
Karen L. Moore ◽  
Leonid Tsybeskov ◽  
Philippe M. Fauchet ◽  
Dennis G. Hall

AbstractRoom-temperature photoluminescence (PL) peaking at 1.1 eV has been found in electrochemically etched mesoporous silicon annealed at 950°C. Low-temperature PL spectra clearly show a fine structure related to phonon-assisted transitions in pure crystalline silicon (c-Si) and the absence of defect-related (e.g.P-line) and impurity-related (e.g.oxygen, boron) transitions. The maximum PL external quantum efficiency (EQE) is found to be better than 0.1% with a weak temperature dependence in the region from 12K to 400K. The PL intensity is a linear function of excitation intensity up to 100 W/cm2. The PL can be suppressed by an external electric field ≥ 105 V/cm. Room temperature electroluminescence (EL) related to the c-Si band-edge is also demonstrated under an applied bias ≤ 1.2 V and with a current density ≈ 20 mA/cm2. A model is proposed in which the radiative recombination originates from recrystallized Si grains within a non-stoichiometric Si-rich silicon oxide (SRSO) matrix.


KronoScope ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 7-27
Author(s):  
Carl Humphries

Abstract “Being is said in many ways,” claimed Aristotle, initiating a discussion about existential commitment that continues today. Might there not be reasons to say something similar about “having been,” or “having happened,” where these expressions denote something’s being located in the past? Moreover, if history – construed not only as an object of inquiry (actual events, etc.) but also as a way of casting light on certain matters – is primarily concerned with “things past,” then the question just posed also seems relevant to the question of what historical understanding amounts to. While the idea that ‘being’ may mean different things in different contexts has indisputable importance, the implications of other, past-temporal expressions are elusive. In what might any differences of substantive meaning encountered there consist? One starting point for responding – the one that provides the subject matter explored here – is furnished by the question of whether or not a certain way of addressing matters relating to the past permits or precludes forms of intelligibility that could be said to be ‘radically historical.’ After arguing that the existing options for addressing this issue remain unsatisfactory, I set out an alternative view of what it could mean to endorse or reject such an idea. This involves drawing distinctions and analogies connected with notions of temporal situatedness, human practicality and historicality, which are then linked to a further contrast between two ways of understanding the referential significance of what is involved when we self-ascribe a relation to a current situation in a manner construable as implying that we take ourselves to occupy a unique, yet circumstantially defined, perspective on that situation. As regards the latter, on one reading, the specific kind of indexically referring language we use – commonly labelled “de se” – is something whose rationale is exhausted by its practical utility as a communicative tool. On the other, it is viewed as capturing something of substantive importance about how we can be thought of as standing in relation to reality. I claim that this second reading, together with the line of thinking about self-identification and self-reference it helps foreground, can shed light on what it would mean to affirm or deny the possibility of radically historical forms of intelligibility – and thus also on what it could mean to ascribe a plurality of meanings to talk concerning things being ‘in the past.’


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