A system dynamics-based scenario analysis of residential solid waste management in Kisumu, Kenya

The problem of solid waste management presents an issue of increasing importance in many low-income settings, including the progressively urbanised context of Kenya. Kisumu County is one such setting with an estimated 500 t of waste generated per day and with less than half of it regularly collected. The open burning and natural decay of solid waste is an important source of greenhouse gas (GHG) emissions and atmospheric pollutants with adverse health consequences. In this paper, we use system dynamics modelling to investigate the expected impact on GHG and PM_{2.5} emissions of (i) a waste-to-biogas initiative and (ii) a regulatory ban on the open burning of waste in landfill. We use life tables to estimate the impact on mortality of the reduction in PM_{2.5} exposure. Our results indicate that combining these two interventions can generate over 1.1 million tonnes of cumulative savings in GHG emissions by 2035, of which the largest contribution (42%) results from the biogas produced replacing unclean fuels in household cooking. Combining the two interventions is expected to reduce PM_{2.5} emissions from the waste and residential sectors by over 30% compared to our baseline scenario by 2035, resulting in at least around 1150 cumulative life years saved over 2021–2035. The contribution and novelty of this study lies in the quantification of a potential waste-to-biogas scenario and its environmental and health impact in Kisumu for the first time

Theory and practice of compilation

Compilation is the translation of high level language programs into machine code. Correct translation can only be achieved if syntax and semantics of programming languages are clearly defined and strictly obeyed by compiler constructors. The author presents a simple extendable scheme for syntax and semantics to be defined rigorously. This scheme fits many programming languages, especially ALGOL-like ones. The author considers statements and programs to be notations of state transformations; in special cases storage state transformations. (5 refs)

Compositional verification of real-time applications

To support top-down design of distributed real-time systems, a framework of mixed terms has been incorporated in the verification system PVS. Programs and assertional specifications are treated in a uniform way. We focus on the timed behaviour of parallel composition and hiding, presenting several alternatives for the definition of a denotational semantics. This forms the basis of compositional proof rules for parallel composition and hiding. The formalism is applied to an example of a hybrid system, which also serves to illustrate our ideas on platform-independent programming

Semantics and implementation problems in LOGLAN with its many level prefixing concept

Lecture held at the ''International Seminar on New Tools of Programming and Means for the Analysis of Programs'', Radziejowice (Poland), Sep 1984SIGLECopy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman