scholarly journals V. The soil solution and the mineral constituents soil

1914 ◽  
Vol 204 (303-312) ◽  
pp. 179-200 ◽  
Keyword(s):  
Phosphoric Acid ◽  
Soil Solution ◽  
Point Of View ◽  
Plant Food ◽  
Soil Particles ◽  
Low Degree ◽  
Short Season ◽  
In Virtue Of ◽  
Low Solubility ◽  
Mineral Constituents

It has long been the accepted theory that plants obtain the mineral constituents they require from the soil through the intermediary of a solution that is formed in the water with which the soil particles remain in contact. As, however, the amounts of phosphoric acid and potash revealed by analysis are always far in excess of the requirements of the crop, and as the variation in these quantities in no way determines the need or otherwise for a further supply of the constituents in the shape of fertilisers, Daubeny suggested a distinction between dormant and available plant food in the soil, the latter being the more readily soluble compounds of phosphoric acid and potash, which in virtue of their solubility determine the amount of each constituent obtainable during the short season of a plant’s growth. This point of view was revived by B. Dyer in 1894, and has been subjected to considerable examination, without, however, revealing any constant correspondence between the quantities of easily soluble plant food and the response of the soil to particular fertilisers. A new aspect of the problem was set forth in 1903 by M. Whitney and F. K. Cameron, who maintained that as all soils contain practically the same compounds of phosphoric acid and potash possessing a very low solubility, the soil solution must become saturated with these constituents to the same low degree of concentration in all soils, irrespective of the actual amounts of phosphoric acid and potash there present.

scholarly journals The Analysis of the Soil by means of the Plant

1905 ◽  
Vol 1 (1) ◽  
pp. 65-88 ◽  
Author(s):  
A. D. Hall
Keyword(s):  
Phosphoric Acid ◽  
Field Experiments ◽  
Weak Acid ◽  
Point Of View ◽  
Barley Straw ◽  
Plant Food ◽  
Living Plant ◽  
Ash Composition ◽  
Modern Methods ◽  
Plant Grown

One of the main problems placed before the agricultural chemist is the estimation of the requirements of a given soil for specific manures, or the interpretation, by means of data obtained in the laboratory, of the behaviour of the soil towards these manures, as seen in properly arranged field experiments. For various reasons the obvious method of determining the proportions of Nitrogen, Phosphoric Acid, and Potash in the soil fails in many cases to give the required information; even the more modern methods of measuring only the quantities of these materials which are attacked by weak acid solvents, and in consequence regarded as available to the plant, by no means always accord with the results of experience. Hence from time to time attempts have been made to attack the problem from another side and to use the living plant as an analytical agent. The scheme is to take a particular plant grown upon the soil in question, and determine in its ash the proportions of constituents like phosphoric acid and potash. Any deviations from the normal in these proportions may then be taken as indicating deficiency or excess of the same constituent in the soil and therefore the need or otherwise of specific manuring in that direction. The theory rests on two assumptions, first that each plant has a typical ash composition, constant when the plant is grown under similar conditions; secondly that the variations in the proportion of such a constituent as phosphoric acid will reflect the amount of that plant food available in the soil, as measured by the response of the crop to phosphatic manuring. From this point of view a number of investigations have already been made: Hellriegel discussed the relative variations of the proportion of potash in the ash of barley straw and of the soil in which it was grown; Heinrich analysed the roots of oats and fixed certain minima, below which the need for specific manuring was indicated.

The composition of milk. Part II: Variation in the percentage of mineral constituents in cow’s milk, and their relationship with the solids not fat and protein content

1927 ◽  
Vol 17 (1) ◽  
pp. 72-93 ◽  
Author(s):  
H. T. Cranfield ◽  
D. G. Griffiths ◽  
E. R. Ling
Keyword(s):  
Standard Deviation ◽  
Phosphoric Acid ◽  
Protein Content ◽  
Ash Content ◽  
Probable Error ◽  
Cow’S Milk ◽  
Frequency Distributions ◽  
Cow's Milk ◽  
Mineral Constituents

1. 670 samples of the mixed milk from 15 herds were analysed, and the average percentages of total ash, soluble ash, insoluble ash, lime and phosphoric acid are given.2. Tables showing frequency distributions are also given, with the standard deviation, mean and probable error of mean for each constituent determined.3. Various correlations of these constituents with solids not fat and protein have been prepared, and these correlations are illustrated by graphs.It is observed that the total ash falls with the solids not fat until low values of solids not fat are reached, when the ash content appears to rise. This variation is confirmed by a curve illustrating the variation in ash content of samples of individual cow’s milk. Soluble ash rises as the solids not fat falls, but the insoluble ash shows a reverse variation. Lime and phosphoric acid both fall with the solids not fat.

Leadership Styles of Public Schools Principals in the City of Hail in the Kingdom of Saudi Arabia: أنماط القيادة لدى مدراء مدارس التعليم العام في مدينة حائل في المملكة العربية السعودية

2021 ◽  
Vol 5 (41) ◽  
pp. 161-138
Author(s):  
Fahad Husain Alshammari Fahad Husain Alshammari
Keyword(s):  
Public Schools ◽  
Leadership Style ◽  
School Principals ◽  
Statistical Significance ◽  
Point Of View ◽  
Years Of Experience ◽  
Public School Principals ◽  
Low Degree ◽  
Study Population ◽  
High Degree

    This study aimed to: Identify the leadership style prevailing among public school principals in Hail from the teachers ’point of view, and to reveal the statistical significance of the differences in the estimates of the study sample individuals of the leadership style prevailing among school principals, which may due to variables of (educational stage, number of years of experience, and specialization). The researcher used the descriptive method, and prepared a questionnaire consisting of (24) statements distributed to (3) dimensions, which are: Democratic style, authoritarian style and chaotic style. The current study population included all the teachers of public education schools in Hail, who numbered (9390) teachers. The questionnaire was applied to a random sample of (296) teachers. The study found a set of results, the most important of which are: The prevailing leadership style among school principals is the democratic style, followed by the authoritarian style, and then the chaotic style. Where the democratic style obtained a mean (4.18) and a high degree of approval from the study sample, while the domineering style obtained a mean (1.83) and a low degree of approval from the study sample, and the chaotic style obtained an average (1.73) and a low degree of approval. Very members of the study sample. The results also showed that there are statistically significant differences in the degree of the study sample’s estimates of the leadership style prevailing among school principals due to the variable of years of experience, while there are no statistically significant differences in the degree of the study sample’s estimates of the leadership style prevailing among school principals due to the variables of the educational stage or specialization. In light of these results, the researcher recommended organizing training courses for school principals to enlighten them about the modern trends in educational leadership, and urged school principals to follow the democratic style of administration.

scholarly journals Status of the quality of education and accountability unit in the educational process from the point of view of the principals of Kasbah Al Mafraq schools: واقع الاستفادة من وحدة جودة التعليم والمساءلة في العملية التربوية من وجهة نظر مديري مدارس قصبة المفرق بالأردن

2020 ◽  
Vol 4 (7) ◽  
Author(s):  
Muneera Abdalkareem Alshdefat
Keyword(s):  
Evaluation Criteria ◽  
Educational Leaders ◽  
Educational Process ◽  
Point Of View ◽  
Quality Of Education ◽  
Development Methodology ◽  
Low Degree ◽  
Study Results ◽  
The Status

This Present study aimed at finding out the Status of the quality of education and accountability unit in the educational process from the point of view of the principals of Kasbah Al Mafraq schools To achieve the goal of the study, a descriptive development methodology was developed, which was developed in three areas (evaluation criteria, cooperation and coordination, feedback and incentives) (21) items, and verified their validity and stability, and then distributed to the sample of the study consisting of (167) managers and directors in schools Kasbah Mafraq. The study results showed that the degree of appreciation and the reality of Status of the quality of education and accountability unit in the educational process from the point of view of the principals of Kasbah Al Mafraq schools was at low degree The average of the tool as a whole was (2.00) with a standard deviation of (.55) and at the level of domains, All of them were rated low, with feedback and incentives having the highest average (2.09) followed by evaluation criteria (2.00) and cooperation and coordination (1.90), and the results showed that there were no statistically significant differences in The study sample of the Status of the quality of education and accountability unit in the educational process from the point of view of the principals of Kasbah Al Mafraq schools, according to gender, at the macro level of the instrument and on all dimensions. The study recommended in light of those results the necessity for that efforts should be join efforts to support and deepen the concept of quality of education and accountability, cooperation and coordination between the quality unit of education and accountability and educational leaders, and try to provide incentives and thanks to those who deserve it, to achieve the concept of guidance and support.

XIX.—On the Composition of Milk as affected by Increase of the Amount of Calcium Phosphate in the Rations of Cows

1915 ◽  
Vol 35 ◽  
pp. 195-202 ◽  
Author(s):  
A. Lauder ◽  
T. W. Fagan
Keyword(s):  
Calcium Phosphate ◽  
Phosphoric Acid ◽  
General Result ◽  
Food Supply ◽  
General Consensus ◽  
The Subject ◽  
Mineral Constituents

The various factors which are supposed to influence the composition of milk have already been the subject of numerous investigations. The general result of these has been to show that within very wide limits the composition of milk is very little affected by the nature of the food supplied. As regards the mineral constituents the results of some of the investigations are rather conflicting, and while there is a general consensus of opinion that the composition and amount of the mineral constituents are independent of the food-supply, certain investigators claim to have been able to increase both the calcium and phosphoric acid in the milk by slight amounts.

scholarly journals A NEW METHOD OF MEASURING THE CONCENTRATION OF THE SOIL SOLUTION AROUND THE SOIL PARTICLES

Science ◽  
1915 ◽  
Vol 42 (1084) ◽  
pp. 507-508 ◽  
Author(s):  
G. Bouyoucos ◽  
M. M. McCool
Keyword(s):  
Soil Solution ◽  
New Method ◽  
Soil Particles

OSCILLATORY BEHAVIOR AS ELECTROCHEMICAL FLUCTUATIONS DURING THE TRANSPASSIVE ELECTRODISSOLUTION OF COPPER IN PHOSPHORIC ACID

2001 ◽  
Vol 01 (03) ◽  
pp. L171-L180 ◽  
Author(s):  
ALI EFTEKHARI
Keyword(s):  
Phosphoric Acid ◽  
Electrochemical Noise ◽  
Oscillatory Behavior ◽  
Copper Electrode ◽  
Point Of View ◽  
General Study ◽  
Potential Region ◽  
Acid Media ◽  
Electrochemical Oscillation ◽  
Current Potential

Transpassive electrodissolution of copper in phosphoric acid was studied froma dynamical point of view. A new electrochemical oscillation named corrosion oscillation as the form of electrochemical noise appears at the corrosion region. The pre-passivated copper electrode in phosphoric acid media shows a fluctuated current within the active potential region. The current oscillation in this system, and generally in electrochemical systems, is sensitive to the initial condition of the electrode surface from heterogeneity point of view. We show that the noise in the current-potential curve is caused by a tiny instability of the passive film, a transition from the passive to extrapassive states and vice versa. Here we demonstrate that the current oscillations can also be observed in the low scale of electrochemical noise. Moreover, the possible mechanism for the electrochemical noise and generally the other noises are also described. The study is of interest from an interdisciplinary point of view as shown by complicated processes such as noises, can be recognized in a dynamical system by applying a closer view in a lower scale. Thus, it is a typical (but not general) study for investigation and monitoring tiny processes in scale, whereas they are so complicated.

scholarly journals How do moral theories stand to each other?

2020 ◽  
Vol 3 (2) ◽  
pp. 279-299
Author(s):  
Svantje Guinebert
Keyword(s):  
Virtue Ethics ◽  
Moral Theory ◽  
Point Of View ◽  
Deontological Ethics ◽  
Basic Orientation ◽  
Moral Theories ◽  
In Virtue Of

AbstractMoral theories, such as the variations on virtue ethics, deontological ethics, contractualism, and consequentialism, are expected – inter alia – to explain the basic orientation of morality, give us principles and directives, justify those, and thereby (if all goes well) guide our actions. I examine some functions and characteristics of the extant moral theories from a moral metatheoretical point of view, in order to clarify the generally assumed rivalry between them. By thinking of moral theories in analogy to languages it is argued that different moral theories are neither simply competing nor simply complementary; their respective orientations justify using them, in virtue of the problems they help to solve. But even if considerations about the functionality of a theory and the context in which it is created play an important role, they can neither be sufficient to determine these theories’ relations to one other nor for choosing between them. The challenge is to set criteria for the quality of a moral theory on a moral metatheoretical level and, in particular, to make room for future views on morality.

Bonding of Rubber to Metal by Means of New Chemical Derivatives of Rubber

1950 ◽  
Vol 23 (1) ◽  
pp. 281-291 ◽  
Author(s):  
Jacques Gossot
Keyword(s):  
Ph Value ◽  
Chemical Reactivity ◽  
Point Of View ◽  
Physical Point ◽  
General Application ◽  
Chemical Derivatives ◽  
Special Cases ◽  
Practical Standpoint ◽  
In Virtue Of ◽  
Derivatives Of

Abstract The bonding process which has been described is of general application to all types of rubber mixtures, to metals, and to various other materials, without any change in composition of the bonding agent for the different materials. Although the problem of adhesion has been approached in this work only from the purely practical standpoint, it should be realized how little progress has been made in the theoretical knowledge of the problem. As a matter of fact, only a few authors have attempted to explain, on a basis of general concepts, certain special cases of adhesion, and there is still no real insight into the problem as a whole which might open the way to material progress. If one turns to the works of MacBain, Delmonte, and Buchan among the most important contributions to the phenomena of adhesion, the ultimate conclusion must be drawn that little has been accomplished in orienting investigations in this field toward more productive ends. From the physical point of view, particular attention must be paid to the condition of the state of the surface of the material to be bonded, to the surface tension, to the viscosity, and to the pH value of the adhesive. The chemical structure of the latter is that of a long-chain compound and, as has been proved conclusively in the present investigation, certain groups play a fundamental role, both in virtue of their chemical reactivity, and in virtue of the polar moment which they confer upon the molecule.

scholarly journals PROBLEMS AND PROSPECTS OF PRODUCTION AND QUALIFICATION OF PHOSPHORIC ACID

2017 ◽  
Vol 60 (7) ◽  
pp. 48
Author(s):  
Nicolay N. Smirnov ◽  
Daria N. Smirnova ◽  
Aleksandr P. Ilyin ◽  
Sergey P. Kochetkov
Keyword(s):  
Phosphoric Acid ◽  
Raw Materials ◽  
Point Of View ◽  
Effective Parameters ◽  
Wet Process ◽  
Thermophysical Model ◽  
Fluorine Compounds ◽  
Sulfuric Acid Decomposition ◽  
Almost All ◽  
Solid Liquid

The qualification of phosphoric acid is carried out depending on the use of phosphates of various deposits and the necessary quality of the final products. An acquisition of phosphoric acid of the required quality should be carried out taking into account three aspects: resource-energy, ecology and complex processing. Solving the problems of one aspect entails solving the problems of the other aspects. The rational use of natural resources and the reduction of environmental pollution is the determining factor in the choice of technological regimes for complex processing of raw materials with a reduction in the volume of waste of all kinds or transferring them into forms easily recyclable or specially stored. The absence of economically sound technologies for processing phosphogypsum determines its preferential warehousing. The second component that requires recycling is fluorine. In this regard, the purification of phosphoric acid from fluorine should use technologies that realize the trapping of fluorine compounds released into the gas phase. This is relevant from the point of view of the complexity of processing raw materials with the extraction of rare-earth elements. The use of mechanochemical activation makes it possible to achieve a nanoscale level. To a lesser extent, this aspect relates to the stage of sulfuric acid decomposition, proceeding with the participation of three phases: solid, liquid and gas. In turn, the surface structure of the gas-liquid layer plays the role of an energy barrier for evaporation. To establish the basic energy patterns of concentration and defluorination n the disc apparatus and to optimize the process, a thermophysical model was developed in which the range of effective parameters was determined by the joint solution of a number of equations for the desired ingredients in the phosphoric acid concentration range of 52-65%. The solution of the problem of complex purification of wet-process phosphoric acid can be carried out by adsorption methods that allow to remove to some extent almost all impurities.For citation:Smirnov N.N., Smirnova D.N., Ilyin A.P., Kochetkov S.P. Problems and prospects of production and qualification of phosphoric acid. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 7. P. 48-56.

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