III.—On the Reduction of Ferric Iron (1) by Sulphurous Acid and (2) by Zinc Dust

1913 ◽  
Vol 32 ◽  
pp. 12-16
Author(s):  
Alexander Charles Cumming ◽  
E. W. Hamilton Smith

So many papers have appeared on this subject that some apology seems desirable before making an additional contribution. The amount of published work on reduction with sulphurous acid is in itself an indication that many workers have found difficulties. It has been shown that the reduction does not take place in presence of large excess of hydrochloric or sulphuric acid, but the reduction will still occur while the reaction of the solution is strongly acid. On the other hand, Hillebrand (“Analysis of Silicate and Carbonate Rocks,” U.S. Bulletin, 442, p. 113) states if the solution after addition of sulphite is red in colour, it is too alkaline and acid must be added.

1976 ◽  
Vol 29 (4) ◽  
pp. 865 ◽  
Author(s):  
CP Joshua ◽  
PK Ramdas

Photolysis of 2,2'-dinitrodiphenylmethane (1) in isopropyl alcohol affords dibenzo[c,f][l,2]diazepin-11-one 5-oxide (7) as the major product. Dibenzo[c,f][l,2]diazepin-11-one 5,6-dioxide (6), acridone (8) and 2,2'-dinitrobenzophenone (9) are also formed in the reaction. Irradiation of (1) in ethanolic sulphuric acid on the other hand yields 3-(2'-nitropheny1)-2,l-benzisoxazole (11) as the major product; small amounts of (7), (8) and (9) are also isolated. Photoconversion of (1) in triethylamine and alcoholic triethylamine proceeds very slowly and compounds (7), (8) and (9) only are isolated from the photolysed solution. Some aspects of the mechanism are discussed.


The following experiments were carried out in the year 1905. Taking a simple voltaic cell, consisting of an anode and cathode of zinc and carbon, and an electrolyte of dilute sulphuric acid, it was found that polarisation, which takes place when the cell is joined to a local circuit of low resistance, could be diminished or completely abolished, by passing through the cell an alternating current of suitable value. Fig. 1 illustrates the arrangement of the cell, D, joined up to deliver current through the ampèremeter, B; under these conditions the cell is very quickly polarised, and the continuous current falls to a very low figure. On the other hand, if a suitable strength of alternating current of. say, 100 periods per second is sent through the cell from the leads A, the cell D will be completely depolarised and will give its full current delivery. L is a self-induction and K a capacity to prevent the alternating and continuous currents from flowing in each other's circuit, the only part of the circuit common to both being through the cell.


1955 ◽  
Vol 33 (1) ◽  
pp. 148-162 ◽  
Author(s):  
R. U. Lemieux ◽  
W. P. Shyluk ◽  
G. Huber

The acetolyses of the alpha and beta methyl D-glucopyranoside tetraacetates in 1:1 acetic acid – acetic anhydride 0.5 M with respect to sulphuric acid were followed at 25 °C. by isotopic dilution analysis of products isolated after various intervals of time. The reaction of the α-glucoside was found to proceed mainly with inversion of the anomeric center. On the other hand, the β-glucoside was found to undergo acetolysis with retention of configuration concurrent with anomerization. It was shown that the polarimetric changes observed in the course of the reactions could be satisfactorily accounted for on the basis of these reaction routes. Reaction mechanisms are suggested.


Geologija ◽  
2021 ◽  
Vol 64 (2) ◽  
pp. 189-203
Author(s):  
Jože ČAR ◽  
Jernej JEŽ ◽  
Blaž MILANIČ

The area between the villages of Reka in the Idrijca Valley, Bukovo and Zakriž near Cerkno belongs geographically and geotectonically to the Dinarides. The area consists of two large inner thrust blocks of the Trnovo nappe, which were thrusted for tens of kilometers in the direction of SW to their present position. They are overlain by the Tolmin nappe, the lowest thrust unit of the Southern Alps. The Tolmin nappe was thrusted from N to S and consists of two inner thrust blocks and a smaller intermediate inner sheet. In the western part of the area the contact between Southern Alps and the Dinarides runs along the regional Sovodenj fault.Although the rocks in the considered thrust units are about the same age, different stratigraphic settings could be recognized. The lithostratigraphic features of the Ladinian-Lower Carnian Pseudizilian beds are particularly striking. Succession of clastic and carbonate rocks was deposited in deep-marine Slovenian basin. In both the Trnovo and Tolmin nappe, Pseudozilian beds occur in the lithologically characteristic sequences but, in the Tolmin nappe, they are developed in a much greater thickness than in the Trnovo nappe and pass continuously upwards into Amphyclina beds, while in the Trnovo nappe, on the other hand, the succession of Pseudozilian beds is much thinner and is overlain by the platform Cordevol dolomite.


2019 ◽  
Vol 10 (1) ◽  
pp. 70 ◽  
Author(s):  
Juan Martinez-Tomas ◽  
Juan A. Marin-Garcia

<p class="Abstract">In previously published research, a great difference is observed concerning salary components that are used in different national contexts. In the present study, we will focus on the Spanish case by using data taken from the salary structure survey (ESS) conducted by the INE (Spanish National Statistical Organization). This protocol raises several research questions. Our main objective is to find out the incidence and degree of use of extrinsic motivation programs in the Spanish labour context. For that purpose, we propose a methodology to analyse the ESS, as well as to find out whether any research has been carried out in this regard. 2006’s pilot analysis is being presented in this moment in order to illustrate step by step the method of analysis.</p><p class="Abstract">Our results show that both degree of use and intensity of the economic remuneration programs related to extrinsic motivation are low (e.g. in monthly payments, the most frequent component is fixed income supplements not related to shifts, which represent 75% of people from ESS2006. Then, we find variable supplements (29%) and fixed supplements related to shifts (15%). Regarding intensity, basic monthly salaries dominate by far as the major part of a salary (73%) while variable extraordinary payments (1.8%), supplements related to shifts (1%), extra hours (&lt;1%) and payment in kind (&lt;1 per thousand) represent a marginal amount of the total salary paid). On the other hand, our results also indicate the existence of several factors that may influence the presence of variable complements (sectoral differences, market scope, organization size, educational level or labour agreement).</p><p class="Abstract">As additional contribution to our work, the present study allows us to know whether the sample collected by academic research is representative or not, since the incidence and extend of use of the economic participation programme should lead to similar results to those provided by the INE. On the other hand, we can identify those adjustment variables that influence in the salary distribution composition. All work done so far allows us to confirm that the research hypotheses are, at least, relevant because they have not been answered up in the literature published to date.</p>


1856 ◽  
Vol 7 ◽  
pp. 11-15 ◽  

Chemists have long been aware of the fact that some acids unite with bases in one proportion only, others in two or more proportions. Thus a given quantity of nitric acid forms with what is termed its equivalent of potash, a definite nitrate of potash; if less than this equivalent quantity of potash were added to the nitric acid, the product would be a mechanical mixture of the same nitrate of potash with uncombined nitric acid; if more than the equivalent of potash were added, the excess of alkali would remain uncombined. Sulphuric acid, on the other hand, is capable of forming two compounds with potash, and it depends upon the proportions in which the two substances are brought together whether the neutral or acid sulphate is formed.


1853 ◽  
Vol 143 ◽  
pp. 67-107 ◽  

Action of Alkalies and Alkaline Earths on Rubian. In the first part of this paper I have described, in general terms, the effect produced on rubian by alkalies. It is only the fixed alkalies that are capable of effecting the decomposition of rubian. Ammonia produces no perceptible change in a watery solution of this substance, except that of altering its colour from yellow to blood-red. This blood-red colour remains unchanged even after long-continued boiling, and the solution still contains rubian, for on supersaturating the ammonia with acid, the solution again becomes yellow, and not the slightest precipitate is produced. The fixed alkalies, on the other hand, act very differently. On adding caustic soda to a solution of rubian, the colour of the solution first changes to blood-red. On boiling the liquid, however, its colour soon changes again from blood-red to purple. This alteration in colour indicates the formation of alizarine. If the boiling be continued, there is deposited, as the liquid becomes more concentrated, a dark purple powder, which consists mainly of a compound of alizarine and soda, and separates in conse­quence of its insolubility in caustic lye. After the liquid has been boiled for some time, then, provided the quantity of soda employed be sufficiently large, the rubian is entirely decomposed. On now adding sulphuric acid in excess, a quantity of orange- coloured flocks, exactly like those produced by the action of acids on rubian, is pre­cipitated, while the liquid becomes almost colourless. These flocks are separated by filtration and washed with cold water, until the sulphate of soda and sulphuric acid are entirely removed. They now consist mainly of four substances, viz. 1st, Alizarine ; 2ndly, Rubiretine ; 3rdly, Verantine and 4thly, a substance which has not hitherto been observed, and to which I shall give the name of Rubiadine .


1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.


Author(s):  
A. V. Crewe

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.


Author(s):  
K.H. Westmacott

Life beyond 1MeV – like life after 40 – is not too different unless one takes advantage of past experience and is receptive to new opportunities. At first glance, the returns on performing electron microscopy at voltages greater than 1MeV diminish rather rapidly as the curves which describe the well-known advantages of HVEM often tend towards saturation. However, in a country with a significant HVEM capability, a good case can be made for investing in instruments with a range of maximum accelerating voltages. In this regard, the 1.5MeV KRATOS HVEM being installed in Berkeley will complement the other 650KeV, 1MeV, and 1.2MeV instruments currently operating in the U.S. One other consideration suggests that 1.5MeV is an optimum voltage machine – Its additional advantages may be purchased for not much more than a 1MeV instrument. On the other hand, the 3MeV HVEM's which seem to be operated at 2MeV maximum, are much more expensive.


Sign in / Sign up

Export Citation Format

Share Document