THE PAPER ESTIMATES THE CONTRIBUTION OF ELASTICITY OF TAX REVENUES TO THE GROWTH OF PUBLIC EXPENDITURES IN THE 50 STATES SINCE 1960. THE ANALYSIS SUGGESTS THAT FEDERAL AID, RATHER THAN TAX ELASTICITY, IS THE BEST PREDICTOR OF STATE EXPENDITURE GROWTH, WHILE LEGISLATIVE CHANGES IN TAX STRUCTURE HAVE HELPED STATES KEEP PACE WITH RISING DEMAND FOR REVENUE DUE TO GROWTH IN POPULATION AND REAL INCOME.
AbstractThis paper reviews the design and performance of constructed wetlands for the treatment of domestic sewage. Horizontal‐flow systems have now become accepted for secondary treatment where only BOD and SS consents are required. However, in recent years there has been increasing interest in systems such as vertical‐flow and hybrid systems which are capable of achieving good nitrification. These systems have a greater and more reliable capability for oxygen transfer. As yet, there are only a few systems of this type in the UK, but the number is likely to increase. The paper describes the performance of (a) secondary and tertiary treatment systems, and (b) sludge‐drying reed‐beds.
Ideas about war & its implications are investigated among a sample of 300 English Sch children at diff ages between 6 & 16 yrs. A cross-cultural comparison is made with a sample of 110 Japanese children in a limited part of the inquiry. It is found that the English children pass through a series of stages in their development & are subject to long & short term influences in their thinking. A number of hyp's are proposed to account for aspects of development & for the apparant limitations placed upon adult thought: (1) There is a close connection between reasoning about war & the roles, strategies & logistics learned earlier in games & play. Nuclear war appears late in the scene, & is subjected to qualitatively similar thought as conventional war. (2) Understanding of the actions of others leans heavily upon an interpretation of their psychol as motivated by hostile instincts. This perception demands at least the cognitive skill of the teenager. (3) Hostile patriotism develops out of defense against potential opponents, & retaliatory attack follows as a means of punishing them. (4) Physical hazards to the self are denied. When faced with a provocative situation, the individual lacks the temporal or spatial imagination to conceive of the consequences, which he knows are likely, as affecting himself. (5) Reasoning about personal, soc & internat'l conflict is linked together into a coherent whole under certain conditions & with a common structure. There is an interchange between ideas about them; this org of ideas is termed the `schema of conflict.' IPSA.
AbstractThe biological filter was introduced during the latter part of the last century but, in 1913, a radical new process was developed which resulted in a four‐fold reduction in the size of sewage‐treatment plants. This new method was called the 'activated‐sludge process', and whilst biological filters are still in use ‐ especially for small works ‐ activated sludge is now the dominant secondary treatment process and is the 'engine'around which modern treatment systems are constructed.This paper (a) reviews the milestones in the evolution of the activated‐sludge process from 1913 to 1954, centering on reliable removal of BOD and suspended solids, (b) highlights the improvements in design capabilities (1955‐74), with the emphasis on the attainment of consistent nitrification, and (c) discusses the removal of nitrogen and phosphorus (1975‐97), with brief reference to computer modelling and the control of sludge properties.
ABSTRACTThis paper reviews the design and performance experience with sludge‐drying reed‐beds over the past fourteen years. Whilst there are very few of these systems in the UK, there is much experience in Europe and particularly in Denmark. The Danish experience is reviewed in some detail. The design of and experience gained from two UK systems is described. The final dry‐solids concentration depends upon the concentration in the initial sludge dose. It is possible, when treating anaerobically digested sludges containing 3–4% DS, to achieve about 90% volume reduction and a final dry‐solids content of up to 40%. With thinner activated sludges containing 0.3–0.6% DS, a reduction (in volume) of greater than 97% is possible with a final solids concentration in the range 10–20%.
ABSTRACTThe paper reviews the current capabilities of processes for phosphorus and nitrogen removal in relation to the EC urban waste water treatment Directive. The Directive is briefly described and the implications for the UK are discussed. This is followed by a review of biological and chemical processes for nutrient removal with special reference to their current state of application and performance. Particular attention is paid to processes for biological phosphorus removal which, in the past, was said to be less reliable than the chemical options but which is now being more widely applied in other parts of Europe as well as South Africa and North America. Processes for modifying both activated sludge and biological filter systems to meet the Directive are briefly described.
ABSTRACTIn the past five years sewage‐treatment systems, based on artificial reed beds, have created much interest in Europe. In the UK, reed bed treatment systems have attracted this interest because of their potential for producing cost‐effective treatment for small communities. In 1985 a UK coordinating group was established to produce an integrated research and development programme for evaluating the process.This paper briefly describes the principles lying behind reed bed treatment systems, and outlines the progress which has been made to January 1988. The results of performance from eight full‐scale and pilot‐scale systems are presented in detail.
