A study was undertaken to investigate the effects of crumb rubber on the strength and mechanical behaviour of Rubberized cement soil (RCS). In the present investigation, 26 groups of soil samples were prepared at five different percentages of crumb rubber content, four different percentages of cement content and two different finenesses of crumb rubber particle. Compressive strength tests were carried out at the curing age of 7 days, 14 days, 28 days and 90 days. The test results indicated that the inclusion of crumb rubber within cement soil leads to a decrease in the compressive strength and stiffness and improves the cement soil’s brittle behaviour to a more ductile one. A reduction of up to 31% in the compressive strength happened in the 20% crumb content group. The compressive strength increases with the increase in the cement content. And the enlargement of cement content is more efficient at low cement content.
In the era of an aging society, age friendly cities planning is gaining in importance. Due to the low mobility of these people, it is important to plan their immediate living environment, ensuring access to facilities and areas that meet the basic needs of this special group of urban space users. The paper analyzes the potential accessibility of older people to green areas, sports and recreation facilities, service and commercial facilities, culture and health care facilities, and public transport stops, in order to delimit problem areas characterized by functional and spatial deficits in this area. In addition, the level and quality of accessibility of older people to the abovementioned elements of development.
The scope of the paper refers to long- and medium-run trends of labour supply in Poland. The main purpose is to determine current trends in the labour supply and its projections till the year 2050. In the theoretical part of the paper determinants of labour supply are considered. The projections are based on the population forecasts till 2050 made by the Central Statistical Office of Poland (CSO) and by the authors’ own simulations. Several variants of upper limit of working age and activity rates are taken into account. The population forecasts by the CSO indicate it will occur big decrease of working age population till 2050. The biggest decrease will refer to the group of working age 18–59/64 years and the lowest decrease in the age group 18–66 years. The analysis shows that the declines in labour supply in the years 2020–2050 will occur in all variants of working age population, the biggest decline in the variant assuming the age group 18–59/64 and the smallest decline – in the group 15–74 years. Retirement age is of big importance for the size of labour supply. This is why it is recommended to encourage older people to prolong their economic activity. It is also necessary to increase activity rates in the working age population.
This article is devoted to the subject of age and the elderly in the Middle Ages, and the manner of viewing elderly people in those times. The author uses Jan Długosz’s Annals, books 9–12, as his basic source. His analysis concentrates on the following questions: Whom did the Polish historian consider worthy of remembrance in his Annals? How did he describe those figures? What words did he use to describe the phenomenon of age or aging? The author analyses the Latin terms used to describe specific older persons, and also presents the perceptions of older women, older men, and elderly people as a group. An attempt is made to answer the question of whether old age was a period of well-being and prosperity in medieval times.
The focus of the article is the Vatin culture settlement at the site of Vinča-Belo Brdo in Northern Serbia. The general idea is that this settlement, whose existence was relatively short in time, benefited from being established by the Danube — a great connective factor in the world of the Middle Bronze Age. It shares many characteristics with the contemporary settlements in the southernmost part of the Carpathian basin, starting from the position in the vicinity of the Danube, at the places which had already been settled in prehistory, prior to the Middle Bronze Age. Not only do they have pottery style in common, but the wider repertoire of finds illustrating the material culture. What’s more, comparison of the material remains from Vinča with the neighbouring sites from the left Danube bank enlightens how the Vatin culture was integrated into a wider space of the Bronze Age cultures of the Carpathian basin, influencing the Balkans hinterland, too.
We measured the bone-specific alkaline phosphatase (ALP) isoenzyme activity in 67 plasma samples from 14 newborn Holstein calves using both a conventional method (featuring heat inactivation) and a commercial agarose gel electrophoresis (AGE) kit; the relevant isoenzymes were termed bone-specific ALP (BAP) and ALP isoenzyme 3 (ALP3). We explored whether the AGE kit afforded reliable data when used to analyze samples from Holstein calves. The blood was collected from the jugular vein of each calf immediately prior to the first colostrum feeding (pre-feeding), 20 and 40 h after pre-feeding, and on days 4 and 7; whereas three samples (from three calves) were not obtained. The total plasma ALP activity varied widely, exceeding the ranges of reference values. On electrophoresis, 52 of 67 plasma samples (77.6 %) clearly contained both ALP isoenzyme 2 and ALP3, as did control human serum. The total ALP activity of the 52 samples ranged from 166–1989 U/L (median: 1013 U/L), whereas the values for the other 15 samples (22.4%) exhibiting abnormal isoenzyme fractionation ranged from 1014–5118 U/L (median: 1780 U/L). In the 52 plasma samples exhibiting clearly separated isoenzymes, ALP3 and BAP activities were strongly positively correlated as revealed by Deming regression (y = 0.93x + 22.6, p<0.0001) and Bland-Altman analysis (ALP3/BAP activities limit of agreement: −5.1%). Thus, the AGE kit yields useful information on newborn calves, and can replace the conventional method when the total plasma ALP activity is less than approximately 1000 U/L.
This paper presents a new approach to study the palaeoecological and archaeological benefits of the previously investigated Szeged-Öthalom area. The aim was to combine the archaeological results with the palaeoecological ones by a new integral view. Age-depth models of 14C dated charcoal were calculated via Bayesian method to reconstruct the sediment accumulation rates in the investigated loess- palaeosol sequences. Moreover, the age of a Mammoth bone found in 1935 at the nearby Palaeolithic site was correlated with the calculated accumulation rates. Through our new results, the age of the Palaeolithic site could be correlated to the late LGM dust-accumulation-peak period. Even if this period is considered as cold and dry, the palaeoecological settings indicated dense forest cover and cool climate in the investigated area. This means that the palaeoenvironment may have encouraged the diffusion of Gravettian hunters in this area, founding campsites like Öthalom in the southern part of the Carpathian Basin.
Searching and exploring the motives of continuing in the profession may be an important objective of efforts undertaken by researchers and people directly responsible for the organization and quality of work. Identifying the needs and expectations of the employee is an important element of her/his adaptation in the work environment. Because the age of life is one of the factors affecting the perception of the world and work, in this article motives of continuing professional activity in group of special educators are described in the age of life context.
Humidity is probably the most important abiotic factor influencing life cycles, distribution, survival, and population dynamics of stored product pests. Although most of these pests can complete their life cycles in any given relative humidity, their prolonged development time, as well as decreased emergence rate and fecundity, have been well documented in several previous studies. In the present study, we evaluated the changes in energetic substances (lipids, soluble carbohydrates, glycogen, and proteins) accumulated in different life stages of larvae and adults of Tribolium castaneum in response to different relative humidity levels (5, 12, 22, 30, 45, and 65%). The results showed that young larvae were more susceptible to low relative humidity levels and desiccation stress. Larvae tended to accumulate higher proportions of lipids during earlier stages while their energy content shifted towards proteins with an increase in their age. Adult beetles experienced a significant decrease in their protein content immediately after they initiated reproduction. The importance of these fluctuations in the biology of the red flour beetles was discussed in detail.
Room temperature vulcanized (RTV) silicone rubber is widely used to prevent pollution flashover with its excellent hydrophobicity and hydrophobicity transfer. However, RTV coatings are at the risk of deterioration and failure in heavily polluted operating environment. In this paper, RTV coated insulators with different suspension heights operating in coal ash polluted areaswere sampled. Pollution degree, pollution composition and aging degree of coatings were tested. The result shows that the insoluble pollution contains Al(OH)3 filler precipitated from RTV coating, which indicates the aging of the RTV coating. The top surface coating is more affected by ultraviolet and rainwater than the bottom surface resulting in more serious degradation. As the pollution degree of the lower phase insulator is heavier than that of the upper phase insulator, the erosion effect of pollution on the RTV coating is more intense. The fillers and rubber molecules of RTV continuously precipitate into the pollution layer, leading to further aging. Therefore, the overall aging degree of the lower insulator coating is more serious than that of the upper insulator coating.
The stance of mysticism on language is located in the field of tensions between the fundamental inability to express the essence of God through the medium of language and the imperative, or the need, to talk about it. In the space betwixt and between, there extends mystic silence as a paradoxical, but effective way of communication and insight. Depending on individual mystics, whose selection from the Middle Ages to the Baroque is presented in the text, silence receives also various additional aspects.
This study aims to explore the effects of age across adult groups on selected aspects of language learning. To achieve the aim, a study was conducted at the Open University of University of Warsaw. It focuses on reasons for taking up learning, relative importance of individual skills, major difficulties, individual goals, emotions and self-assessed ability to learn. The assumption that adults represent a single age group is questioned and the results are interpreted in terms of practical implications for course design.
APNB (alkaline phenolic no bake), widely known as Alphaset is one of the major sand binder systems used in foundries to make molds and cores without application of heat or gas. This is a two part system comprising of a phenol-formaldehyde resin in alkaline medium as binder and range of esters of dibasic acids and/or polyhydric alcohols as hardeners.
Resin performance varies depending upon formulations. Major variables in formulations are mole ratio of phenol: formaldehyde, total alkali content, ratio of two alkalis (NaOH & KOH) and molecular weight of polymers i.e. chain length.
In present work, one mole ratio of phenol & formaldehyde has been chosen to prepare 8 resins with following details.
Table 1.
Physical and chemical properties of eight (fresh) resins, A to H
Properties | A | B | C | D | E | F | G | H |
Viscosity at 30°C (mPs-a) | 56 | 47 | 66 | 51 | 39 | 44 | 49 | 52 |
Na (%) | 5.94 | 3.21 | 5.94 | 3.21 | nil | 2.73 | nil | 2.73 |
K (%) | nil | 3.31 | nil | 3.31 | 7.18 | 3.87 | 7.18 | 3.87 |
Molecular weight | Low | Low | High | High | Low | Low | High | High |
Gel Time at 121°C, mt-sec | 27-0 | 29-30 | 24-0 | 30-0 | 30-0 | 27-30 | 26-30 | 26-0 |
Moisture (%) | 52.43 | 52.42 | 53.01 | 53.75 | 55.58 | 54.12 | 51.61 | 54.03 |
Non-volatile Content (%) | 48.74 | 47.25 | 49.10 | 49.35 | 47.63 | 47.32 | 48.06 | 48.29 |
Specific Gravity | 1.182 | 1.177 | 1.183 | 1.180 | 1.172 | 1.184 | 1.178 | 1.188 |
Free Phenol (%) | 0.47 | 0.42 | 0.44 | 0.43 | 0.37 | 0.27 | 0.41 | 0.20 |
Properties of these 8 formulations have been studied for strength and viscosity over a period of 12 weeks in 4 week interval.
Attempt has been made to develop a simple test for simulating hot & retained strength of molds in laboratory. Process followed for chasing hot and retained strength is described under clause 2.
With more and more understanding of the chemistry of alphaset system in last three & half decades it has been possible to identify role of variables contributing towards specific properties vis a vis developing tailor made formulations to fulfill requirements of individual foundries right from mold making to de coring.