Economic control of fertilizer in highly productive pastoral systems. III. A hypothetical model to quantify upgrading from a primitive into a highly productive state

A model suitable for quantifying the upgrading of primitive pasture by phosphatic fertilizer is described; the model, based on the Mitscherlich-Spillman equation, provides a criterion for judging when upgrading is complete. Such information is essential to permit a successful experimental attack on the problem of providing fertilizer-advice for highly productive systems where the nutritional requirements both of pasture plants and grazing animals have to be satisfied. The advice must therefore have a sound basis in physiology as well as in economics; but, the generally accepted modern approach cannot be integrated into a logically consistent and practically possible solution to this complex problem. Consequently, the present proposals involve a number of innovations to replace inadequate concepts in the current approach; the most important of these are as follows.

1. Replacement of the economic theory of isoquantal substitution by production function analysis of long term average response by pasture to a complete (physiologically balanced) mixture of fertilizers.
2. Use of a hypothetical model justified by biological theory rather than an empirical model justified by a least squares-best fit criterion.
3. Replacement of multilevel factorial field experiments by simple 3-level trials representatively dispersed over the whole of the commercially productive area and carried on for a decade.
4. Exclusion of grazing animals from the main phase of a simple trial, but with their heterotrophic cycling of nutrients effectively simulated by a modified experimental technique.
5. Systematic use of foliar chemical analysis, which in one way or another is essential to supplement each of the first 4 innovations.

     

Mathematical modeling and predicting wildland fire effects

A qualitative assessment is made of the role of mathematical modeling in predicting the effects of wildland fires. Specific roles for mathematical models of physical processes involved in causing fire effects are identified in creating decision aids for helping managers make better decisions in planning fire use and in strategic planning of wildfire suppression. More direct roles are seen in helping to strengthen our knowledge base about fire effects through more efficient use of research resources. In assessing the potential utility of mathematical models in these roles, a novel taxonomy of wildland fire effects is introduced, based on longevity of the effect, time delay between fire and emergence of effect, and distance between fire and effect. Physical processes are identified as candidates for mathematical modeling, as factors complicating the realization or use of the models. Candidate modeling topics are identified as

1. Heat transfer in and near the fire environment,
2. Combustion processes and products,
3. Heat and mass transport in porous media,
4. Chemical and physical responses of fire-heated soils,
5. Erosion and hydrology of fire-affected sites,
6. Fluid mechanics of wind and fires,
7. Transport, dispersion, and aging of fire emissions in the atmosphere, and
8. Global atmospheric effects.

Then, using the fire-effects taxonomy described, qualitative practical limits on the predictability of processes involved in them are deduced by considering contributing complicating factors that are identified as not likely to be modeled reliably. By so doing, the list of candidate topics for mathematical modeling is refined and reduced to the following recommended set. Heat transfer to, and thermal response of, live vegetation parts within and near the fire environment. Heat transfer to soil under burning duff. Heat transfer to soil exposed to fire environment without duff cover. Heat and mass transfer in fire-heated porous media. Physical, chemical, and hydrological responses of soils to high-temperature environments. Fluid mechanics of wind fields interacting with fire and vegetation cover.     

Nouveau type de piles Leclanché

The performances of the couple Zn/MnO₂ have been studied with a new electrolyte Mg(ClO₄)₂-Mg(OH)₂. The principal improvements introduced, with respect to the traditional Leclanché cell, concern the ability to retain capacity when stored at high temperatures and the specific power. The characteristics of the cells thus achieved (in the form of the R6 type of cell) are:

1.42 V for the rest potential

only 15% of loss of capacity after 4 months of storage at 60°C

improvement in the efficiency of the manganese dioxide during continuous discharge at high current

flatter discharge level.

     

Quality control in fruit processing

The attainment of high-quality palm products at minimum cost demands that more emphasis be placed on the production side, i.e., the effort must be concentrated at the field and mill level. All field and mill personnel must be involved in quality control and must be responsible for the quality requirements. A long-range effort at developing employee responsibility and job enlargement is required. For this to have a real chance of success, the following should be present:

?Top management’s commitment: The estate manager and the mill manager are the key to assuming responsibility for quality. Estate and mill managers must be openly and actively committed to improving quality.

?Quality policy: Estate and mill managers must decide what level of quality they can deliver to the marketplace, as well as how they expect to accomplish their goals.

?Quality responsibility: Estate and mill organizations should be structured to utilize quality improvement efforts through quality control circles (QCC).

?Quality supervision: Field supervisors, mill foreman and mill supervisors should be trained in human relations and quality control methods.

?Quality consultation: Quality control department should be well run to assist field and mill personnel in establishing good quality practices and procedures.

?Quality training: QCC should be provided with in-house training on basic statistical tools and cause/effect diagrams.

?Quality incentives: Compensation of workers and QCC should be linked to reduction of product losses, reduced downtime, etc.

?Quality recognition: Public recognition should be provided for groups and individuals responsible for quality improvements and suggestions.

?Quality feedback: A well-organized system should exist to disseminate information and improve quality improvement. Continuous informal and formal interaction should occur between design and mill personnel, thereby stimulating quality improvement in the milling stage.

The activities needed to achieve high-quality palm products are scattered among many persons in many specialized departments. Some of these are in-house, while others may be a part of vendor companies, subsidiaries, etc.     

Agriculture and energy with special reference to mineral fertilization

1. The world consumption of energy is roughly 250 EJ. It increases with the level of technology and gross national product of a country. More than 83% of world energy consumption is used by the industrialized countries with one third of the world population; not quite 17% is used by the developing countries with two thirds of the world population. The world's resources of fossil fuels are estimated at 364,560 EJ; about 5–13% of this, and 31% in the case of natural gas, are considered reserves that are economically recoverable and utilizable with current technologies.
2. Agriculture's share of the economy's energy consumption in the Federal Republic of Germany is about 3.4%. It was five times higher per hectare of agricultural land in 1975 than in 1880, but the productivity of the energy was only half as high because of the enormous increase in productivity per unit of labor and area. In absolute terms, however, energy production per unit area increased tremendously, with gross agricultural production two and a half times its earlier size.
3. As a producer of plant material, agriculture qualifies as an energy producer, while as a producer of livestock it also is an energy consumer. In fact, through plant production agriculture becomes the only branch of our economic system that produces more energy than it consumes as fossil energy. Agriculture uses about 40% of its energy requirement for fuel, about 20% for machinery repair and replacement, 30% for mineral fertilizers, about 10% for electricity, and 1–2% for chemical crop protection. Forestry can be evaluated as particularly favorable from the energy viewpoint, while hothouse crops are very unfavorable. Agricultural chemicals support the energy output of green plants; agriculture as a whole is on balance energetically.
4. Solar energy and photosynthesis are the primary sources of energy to our plant. About 3 million EJ solar energy are radiated to the earth annually; 3000 EJ are fixed photosynthetically (2 ? 10¹¹ tons vegetable matter); the food requirement of 4 billion people is 15EJ. Another item of interest on the periphery of the energy balance is the enrichment of our atmosphere with oxygen, which has been accomplished for millions of years solely by the photosynthesis of green plants.
5. Through their additional yield effect, mineral fertilizers increase the energy output of plants more strongly than just the equivalent of the energy input. They cause the plant to produce more foliage and thereby promote more intensive assimilation, which means that mineral fertilizers enable the plant to utilize free solar energy better. A calculation of the energy involved in long-term field trials in cereals disclosed energy input: energy output ratios of 1:5.8 and 1:6.1.
6. Chemical crop protection has a similar effect since it protects against loss of plantproduced energy. Based on an average energy expenditure of 263 MJ ha^?1 per kg ha^?1 ‘typical’ active ingredient for a crop protection product, additional yields of only 4–4.5% — or considerably less in the case of high-energy crops such as cereals or sugar beets — would be sufficient to cover the energy expenditure; as a rule, however, the productivity of the chemical crop protectants is higher. The biological potential of our crops to utilize solar energy also has been improved considerably compared to earlier times — with cereals, for example, from 0.25% per unit area during the Middle Ages to 1.5% today; theoretically 4% is possible. The thesis that agrochemical aids in agriculture and horticulture are a waste of energy is unjustified.
7. Biomass also creates energy. Experts estimate the utilizable annual production of biomass in the Federal Republic of Germany to be 30 million tons mineral coal units (1 coal unit = 29.3 MJ), whereby undersized and refuse wood, straw and biogas are of special significance. Especially “fuel forests' of, for example, willows, poplars and alders could produce the equivalent of 486,000 MJ by way of 30 tha^?1 biomass, contributing sizably to the fuel supply of the nation; at the moment, the conventional form of forestry produces only 30,240 MJ. It is considered feasible in Sweden to supply the entire energy requirement of the country from 93,000 km² of ‘fuel forest’, and it must be remembered that mineral fertilization could be used to increase the productivity of land used for this purpose relatively quickly if the need were to become acute. The extraction of alcohol from crops offers other interesting aspects; the currently highest yield fuel crops (sugar beet, sugarcane and cassava) produce between 4,900 and 10,700 l ha^?1 alcohol.
8. The energy problem of modern economies will not find its complete answer in the green plant. Prudent and well contemplated use of the green plant, however, may eventually do much to take the edge off today's energy dilemma.

     

Anodic pickling of stainless steels in sulphuric acid

Potentiostatic pickling in 20% aqueous H₂SO₄ was investigated on hot- and cold-rolled strips of stainless steels from industrial lines, in order to assess the potentiality of this technique. Experimental evidences for AISI Types 202, 304, 316, 410 and 430 are given. Optimum pickling conditions were defined on the basis of the potentiodynamic behaviour of oxidized specimens. Visual and electrochemical evaluation of pickled surfaces showed that:

1. The potentiostatic technique makes descaling and pickling of stainless steels quite feasible in sulphuric baths;
2. remarkable advantages result over ordinary chemical treatments in terms of speed of scale removal;
3. a higher efficiency of restoration of passivity properties also results.

     

Fresh water from the sea,a new process

• 1. 1. The process is designed to produce ice crystals uniform in shape and size, without the formation of other new nuclei.
• 2. 2. Nucleation and crystal growth are separate operations; the former is batch-wise; the latter is continuous.
• 3. 3. The predetermined number of nuclei charged to the crystal chamber is equal to the production per unit divided by crystal weight.
• 4. 4. The refrigerant is supplied along the flow path in the chamber at a rate equivalent to the crystal growth rate.
• 5. 5. Separation of the uniform crystals from the residual sea water is a true gravity operation - the less dense ice floating away from the more dense residual sea water.

     

Chemical modification of polymers I. Applications and synthetic strategies

This paper does not claim to be an exhaustive review of chemical modification but rather aims to illustrate with some examples the vast possibilities offered by this method of synthesis. Grafting and crosslinking reactions as such, which lie outside the present concept of chemical modification (defined as the application of macromolecules in the traditional reactions of organic chemistry) as well as reactions in heterogeneous media do not form part of this review. Five aspects of main interest are:

• •—synthesis of copolymers not accessible by classical means,
• •—comparison of polymer modification and polymerization of functional monomers,
• •—aids to the analysis of polymer microstructures,
• •—introduction of reactive sites along a polymer chain,
• •—fixation of active molecules.

Chemical modification of polymers is generally undertaken to synthesize polymers for well defined applications as can be seen in the case of supported catalysts and reagents, phase transfer catalysts, supported syntheses, and pharmacological use. The synthetic strategies will be described in more detail in Part II (fixation of acids on a polymeric chain). Part III will emphasize the kinetic aspects of the chemical modification of polymers and Part IV will deal with complex reactions.     

Some important fermented foods of Mid-Asia,the Middle East,and Africa

Other speakers in this Symposium discussed fermented foods of China, Japan, and Southeast Asia; I will describe several other fermented foods that are very important in Mid-Asia, the Middle East, and Africa. These fermentations, unlike those of the Orient, use bacteria and yeasts instead of filamentous fungi. They are acid products prepared from cereals traditionally grown in the areas, notably sorghum, millet, maize, and wheat. Since African, Middle Eastern, and Mid-Asian fermented foods are often supplemented with milk or legumes, the final protein content may be rather good. For example, bouza and ogi have a protein content of 11 to 13% on a dry weight basis, while in kishk the protein content is about 23.5%. In the Indian food idli, the protein average content is 15.3%. Advantages of acid fermented food products are:

? Preservation of the fermented product because of the organic acids produced. These acid products are sometimes dried to give even longer keeping times.

? They are high in fiber content.

? Because some are dried, they may be transported easily from one place to another.

? They probably have enhanced nutritional value because of the vitamins formed during production.

? They are foods used for centuries and therefore culturally acceptable.

? Unlike some of the other fermented foods discussed, they are used as main course dishes rather than flavoring agents.

An example of a Mideast food prepared by lactic acid bacteria is tarhana of Turkey, which consists of parboiled wheat meal, yogurt, and added vegetables which are then allowed to ferment and then sun dried. In Central and South Africa, kaffir beer (Bantu beer) is made by malting maize or sorghum, fermenting with lactic acid bacteria to give a low pH, and then finally fermenting with a yeast. The protein content ranges from 8.5 to 11.9%. A second commercially produced product is mahewu (magou) prepared by the natural fermentation of maize to produce an acid mash which is then dried. This food has a content of 7–9% protein.     

Electrochemical properties of aluminium alloys containing indium,gallium and thallium

The electrochemical behaviour of aluminium alloyed with small amounts (up to 0.2%) of indium, gallium and thallium has been investigated. It has been found that these additions result in:

1. A considerable shift of the rest potential in the negative direction (to 1.4–1.7 V versus SCE),
2. A significant increase of the passivating current density (up to 0.1–1 Acm^?2) and
3. A considerable decrease in the negative difference effect (increase of the faradaic efficiency to

99.5%) compared to the behaviour of pure aluminium. Except for the gallium alloy, the rate of corrosion of the alloys in neutral salt solutions is also decreased compared to that of pure aluminium. A ternary alloy, Al-0.01 In-0.01 Ga, exhibited a more negative rest potential than the Al-In alloy and a corrosion stability superior to that of the Al-Ga alloy. The negative difference effect was found to depend on the cation of the neutral salt in solution. The lowest effect was obtained in ammonium chloride solutions.     

Effect of different nitrogen levels,plant population and soil nutrient status on yield and yield components of maize (Zea mays L.) in different ecological zones of Nigeria

Field studies on the effect of nitrogen levels, plant population and soil nutrient status on maize yield and yield components at eight different sites representing six different ecological maize growing zones of Nigeria conducted during 1976, 1977 and 1978 indicated that N significantly influenced yield at six of the eight sites, NIFOR, Umudike and Uyo (rain forest zone), Mokwa and Samaru (Savanna zone) and Riyom (derived savanna zone). Optimum N required for maize varies between 50 and 100 kgN in the different zones. There was no response to spacing except at Umudike, Uyo and Riyom, and no significant interaction between N and spacing at any location. Nitrogen application significantly influenced earweight at Ikenne, NIFOR, Umudike, Uyo and Mokwa. Nitrogen application had a significant effect on the number of cobs at NIFOR, Uyo and Mokwa, while spacing significantly influenced number of cobs at all locations except Uyo. Husk weight was significantly increased by nitrogen application at four locations, NIFOR, Uyo, Mokwa and Samaru, but spacing had no effect on this yield component in any of the other locations except Umudike. There was an N by spacing interaction on husk weight at Umudike and Mokwa. Nitrogen application significantly influenced lodging at tasseling at Uyo, Mokwa and Riyom, whilst there was a significant effect of spacing at Uyo and Samaru. At harvest, lodging was not influenced by N application but spacing significantly affected lodging at Ibadan and NIFOR. Both N application and spacing had no significant effect on shelling percentage at any location. The high correlation between relative yield and available Zn(r = 0.77), Cu (r = 0.63) and Fe (r = ? 0.66) of the soil at all the locations has shown that:

1. other nutrients besides N, P and K affected maize yield, therefore the inclusion of other nutrients besides N, P and K in the fertilizer recommendation for maize should be encouraged;
2. different levels of NPK fertilizer plus other nutrients are required in each ecological zone and this can be determined by soil testing.

     

Synthesis of amines from higher aliphatic esters,ammonia and hydrogen

• 1.1. A study was made of the effect of operational parameters on amination of esters on a fused iron catalyst. Conditions were found to obtain aliphatic amines with a yield of up to 85–86%.
• 2.2. During amination of aliphatic esters both the acid and the alcoholic group of the initial ester take part in the formation of amines.

     

Inhibiting properties of thio- and dithiophenates of transition metals in oxidation of pentaerythritol and monocarboxylic acid esters

• 1.1. Transition metal complexes studied which contain, sulphur are oxidation inhibitors of lubricating oils based on petaerythritol and monocarboxylic acid esters of a C−C₉ fraction.
• 2.2. The antioxidative effect of metal complexes is due to chain termination by the reaction with peroxyl radicals with simultaneous repeated decomposition of hydroperoxides with low free radical yield in the volume.

     

Conversions of propylene on CaNaY and NiNaY zeolites

• 1.1. Studies were made of conversions of propylene on CaNaY and NiNaY zeolites at temperatures ranging from 150 to 350°. It was found that olefins and paraffins (C₂ and C₄) are formed as a result of the breakdown of polymer products formed.
• 2.2. On increasing temperature to 250°, butylene yield increases by 4–5% wt. on the zeolites studied with a practically constant yield of ethylene. A further increase of temperature has no effect on butylene yield, but increases ethylene yield.

     

Preparation of p-isopropylphenol by selective oxidation of p-di-isopropylbenzene

• 1.1. A method was developed for preparing p-isopropylphenol by oxidation of p-di-isopropylbenzene with a monohydroperoxide yield of 90%.
• 2.2. In acidic decomposition of monohydroperoxide of p-di-isoprophybenzene in the presence of cation exchange resins p-isopropylphenol yield was 98–99%. Kinetic studies of acidic decomposition of monohydroperoxide of p-di-isoprophylbezene show that the rate of acidic decompositon in the presence of catalysts containing a nitro-group is doubled.

     

Preparation of maleic anhydride derivatives by catalytic oxidation of halogenobutadienes

• 1.1. A study was made using a laboratory continuous device of oxidation of chloroprene to chloromaleic anhydride (chloromaleic acid) in a fluidized layer of a vanadium-phosphorus catalyst. At the optimum temperature of 470°C, a contact time of 0·80 sec maximum chloromaleic acid yield (32·0 wt.%) is ensured; catalyst output is 203 g of chloromaleic acid/l.·cat·hr.
• 2.2. A study was made of oxidation of hexachlorobutadiene to dichloromaleic anhydride on a VP catalyst. The optimum temperature was found to be 480°C, contact time 0·70 sec. Under the conditions observed process selectivity was 80 mole % with 90% conversion of hexachlorobutadiene.

     

Isolation and f.i.m.s. analysis of saturated hydrocarbons from tar sand bitumens

Saturated hydrocarbons in two Utah tar sand bitumens were determined via compound-type isolation and mass spectral analyses. Four analytical methods for isolating saturated hydrocarbons were evaluated:

• 1.1) dewaxing,
• 2.2) modified deasphaltening,
• 3.3) adsorption and complexation chromatography,
• 4.4) desorptive Soxhlet extraction followed by complexation chromatography.

The latter method was preferred for concentrating the greatest amount of saturated hydrocarbons without overlap from aromatic or heteroatom-containing species. Field ionization mass spectrometry (f.i.m.s.) adequately profiled these hydrocarbons by molar mass (m/z) and by Z-series type. The sample of Northwest Asphalt Ridge bitumen was comprised of a wax of mostly acyclic and monocycloalkanes; whereas, the saturates from the sample of Asphalt Ridge bitumen were mostly tetracyclo- and penatcycloalkanes. Based upon a comparison of the saturate distributions in the samples of bitumen, the sample from the Northwest Asphalt Ridge deposit was found to have undergone less biodegradation. This wax-like sample of bitumen may have migrated to the deposit at a later time than the major bitumen generation and/or resulted from physicochemical segregation of waxy organic matter in the reservoir.     

Ion-conductive macromolecular gels and membranes for solid lithium cells

The formation of a quasi-solid gel electrolyte and its utilization in a lithium cell are described. The conditions of compatibility between constituents are defined as gelling of the system and absence of selfdischarge. Also defined are the electrical, mechanical, and thermal properties required. Two types of electrolytes are considered:

1. Ternary thermoplastic gels, principally based on polyvinyl acetals and polyacrylonitrile. Thin separators made of these materials generally require a porous or mesh support.
2. Thermosetting self-supporting gels, obtained by cross-linking hydroxylated polyvinyl acetals or certain fluorinated polymers, which give the best compromise between mechanical properties, ionic conductivity, and solvent retention. Discharge tests made on single Li/CuS cells and on 10 V batteries indicate that these new solid elements show definite promise for applications which require high energy densities (1 kWh dm^?3) at low drains (?1 mA cm^?2).

     

N-2-pyridyldialkylthioamides as additives to lubricating oils

• 1.1. New compounds — N-2-pyridyldialkylthioamides — have been synthesized.
• 2.2. These compounds are effective anticorrosion additives to M-11 oil and in this respect are superior to additive ABS-2 (a compound of similar structure) and equivalent to thioformpiperidine.
• 3.3. N-2-Pyridyldialkylthioamide has greater antiscuff properties than thioformpiperidine and additive ABS-2.
• 4.4. Increase in the number of thiocarbonyl groups (C=S) in the thioamide molecules leads to an improvement in their antiscuff properties.

     

Preparation of benzothiophen compounds from bicyclic sulphides

• 1.1. Bicyclic sulphides of 2,3-dihydrobenzothiophen and thiochroman series readily undergo dehydrogenation and dehydro-isomerization to compounds of benzothiophen series in the presence of catalysts with aprotonic acidity (Al₂O₃; 10, 20% ZnCl₂/Al₂O₃). Transformations of thiochroman take place with compression of the six-membered heterocycle.
• 2.2. 20% ZnCl₂/Al₂O₃ is the optimum catalyst for aromatization of compounds of the 2,3-dihydrobenzothiophen series. Yields of benzothiophen compounds from mono-substituted bicyclic sulphides (2- and 3-methyl-2,3-dihydrobenzothiophens) reach 56–72% with a process selectivity of 85–96%. The yield of benzothiophen compounds from a di-substituted bicyclic sulphide (2,2-dimethyl-2,3-dihydrobenzothiophen) exceeds 50% with a process selectivity of 75%.
• 3.3. 10% ZnCl₂/Al₂O₃ is the optimum catalyst in aromatization of thiochroman. Benzothiophen yield exceeds 50% with a process selectivity of 82%.
• 4.4. The proposed catalytic method of obtaining benzothiophen compounds is simple and promising as bicyclic oil sulphides may be used as raw materials for this purpose.