Phonological units for phonological change: synchrony shall provide them

The question of what types of units and domains are needed in order to capture phonological change is a reasonable one to ask. To answer this question, however, we first need to properly define how we understand phonological change, and the definition that we adopt for that clearly depends on the phonological framework that is assumed. I consider several influential frameworks here and then come to the conclusion that the same condition holds for all of them: change can only be described in terms of the same units (and domains) as are used for synchronic description. This leads to the following conclusion: the set of units for phonological change is a subset of the set of units that are needed for synchronic phonological description. However, it is also unlikely that some units needed for synchronic description can be fully ignored for all descriptions of changes, which leads us to the conclusion that the set of units that are needed for phonological change is also a superset of that set. The sets are thus equal: the phonological units needed for synchronic description are the units needed to account for phonological change, and the question above is meaningless

Polarized Protons in HERA

Polarized proton beams at HERA can currently only be produced by extracting a beam from a polarized source and then accelerating it in the three synchrotrons at DESY. In this paper, the processes which can depolarize a proton beam in circular accelerators are explained, devices which could avoid this depolarization in the DESY accelerator chain are described, and specific problems which become important at the high energies of HERA are mentioned. At HERA's high energies, spin motion cannot be accurately described with the isolated resonance model which has been successfully used for lower energy rings. To illustrate the principles of more accurate simulations, the invariant spin field is introduced to describe the equilibrium polarization state of a beam and the changes during acceleration. It will be shown how linearized spin motion leads to a computationally quick approximation for the invariant spin field and how to amend this with more time consuming but accurate non-perturbative computations. Analysis with these techniques has allowed us to establish optimal Siberian Snake schemes for HERA

The use of processed polyethylene products in the manufacture of plastic lubricants

It is proposed to expand the raw material base for the production of greases by using used motor oils and solid waste polyethylene products. The results of a laboratory study have been presented; they made it possible to establish that the optimal concentration of the thickener in oil fluctuates within a rather narrow range of 5.0–7.0 wt%. Thus, the obtained greases are identical in quality to the greases of the type Estan 2 (Exxon Co.) and AGIP Grease CC 2 but are much cheaper in produc-tion. The approach to attracting secondary energy resources to the technological process of greases production will meet the existing demand for lubricants and significantly reduce the envi-ronmental burden on the environment

The prospects of obtaining plastic greases from secondary hydrocarbon raw material

The paper presents the results of producing lubricating grease from industrial and household waste in the laboratory. Partially prepared diesel engine oil SAE 10W-40 was used as a dispersion environment, and high and low pressure polyethylene (household polyethylene bags used) was used as thickener. It has been established that by using selected base oil, thickener and anti-wear additive DF-11, recy-cling oils can be obtained, which will be classified according to DIN 51502 to K2PF-30 and K3PF-30. It is proposed to expand the raw material base for the production of recycling oils through the using of waste industrial, hydraulic, transmission oils, as well as high-boiling petroleum fractions extracted from oil sludge or acidic tar and selective waste distillate oils. On the basis of the analysis of the researching results, it was established that on the basis of exhausting motor oil and polyethylene with the addition of additives of different functional purpose, it is possible to obtain a number of antifriction plastic lub-ricants used in swing bearings, railway and protective greases that can be used in the range of oper-ating temperatures, on average up to 100ºC

Production of plastic lubricants on the basis of waste lubricated oils

The results of studies of used lubricating oils, various functional purposes and greases obtained on their use as a thickener 5 wt % of secondary low-pressure polyethylene have been presented. Depending on the operating conditions in the samples of waste oils, the content of water and mecha-nical impurities varies in the range of 0.03-0.3 wt %, 0.08-1.30 wt %. Heating the oils to a temperature of 230°C showed that in the area of heating to a temperature of 200°C, the mass loss and decrease in viscosity are not significant, however, if this temperature is exceeded, an intensive process of destruction of oil hydrocarbons begins, and it will negatively affect the quantitative yield and perfor-mance properties of the lubricant. The obtained results showed that the lower the viscosity of the base oil from which the grease is made, the less stable it is during storage and operation, the worse its adhesive properties. Waste motor and transmission gear oils are advisable to use in the production of antifriction greases while hydraulic and industrial plastic lubricants are better to use in the production of protective greases

Possibility of producing plastic lubricants by thermal destruction of solid domestic wastes

The results of non-catalytic thermal destructive processing of solid domestic waste at atmospheric pressure and temperature of 360°C, which are represented by products of low pressure polyethylene, are presented. The products obtained during degradation can be divided into fuel products (gas, liquid hydrocarbon fraction, coke residue) and fraction (with the beginning of boiling in the temperature range 200-320°C), which can be used in the production of greases. After the heat treatment and cooling of these fractions, a product with properties similar to NYCO 65 VASELINE (Technical petrolatum (GREASE)) can be obtained. For the production of plastic lubricants with other properties and a large temperature interval of application, a scheme has been proposed, it provides for the addition of fillers and additives of different functional purpose to the lubricant obtained

Production of plastic lubricants on the basis of waste lubricated oils

The results of studies of used lubricating oils, various functional purposes and greases obtained on their use as a thickener 5 wt % of secondary low-pressure polyethylene have been presented. Depending on the operating conditions in the samples of waste oils, the content of water and mecha-nical impurities varies in the range of 0.03-0.3 wt %, 0.08-1.30 wt %. Heating the oils to a temperature of 230°C showed that in the area of heating to a temperature of 200°C, the mass loss and decrease in viscosity are not significant, however, if this temperature is exceeded, an intensive process of destruction of oil hydrocarbons begins, and it will negatively affect the quantitative yield and perfor-mance properties of the lubricant. The obtained results showed that the lower the viscosity of the base oil from which the grease is made, the less stable it is during storage and operation, the worse its adhesive properties. Waste motor and transmission gear oils are advisable to use in the production of antifriction greases while hydraulic and industrial plastic lubricants are better to use in the production of protective greases

Technology of recycling waste lubricant greases

A scheme for the production of plastic greases based on high-boiling fractions of oil sludge and used lubricating oils, as well as polymer waste, in the form of HDPE, LDPE, and PP, that is used as a thickener, has been proposed. Based on the used lubricating oils and polymer thickeners, grease lubricants were obtained. They can be used in the temperature range, on average, up to 80–130 °C (depending on the polymer) and speed mode in the bearing up to 4000 rpm. These greases are not worse in their properties to classical ones; analogs obtained based on distillate fractions, thickened with metal soaps, which are widely used in industry today