Improved asymptotic bounds for codes using distinguished divisors of global function fields

For a prime power $q$, let $\alpha_q$ be the standard function in the asymptotic theory of codes, that is, $\alpha_q(\delta)$ is the largest asymptotic information rate that can be achieved for a given asymptotic relative minimum distance $\delta$ of $q$-ary codes. In recent years the Tsfasman-Vl\u{a}du\c{t}-Zink lower bound on $\alpha_q(\delta)$ was improved by Elkies, Xing, and Niederreiter and \"Ozbudak. In this paper we show further improvements on these bounds by using distinguished divisors of global function fields. We also show improved lower bounds on the corresponding function $\alpha_q^{\rm lin}$ for linear codes

MANAGEMENT PRACTICES OFWASTEWATER SLUDGE

Large amounts of wastewater sludge, a secondary pollutant of wastewater treatment plants, commonly containing over 90% water and pathogens, organic pollutants and heavy metals, are produced daily worldwide.  Main treatment routes of wastewater sludge are: landfill, anaerobic digestion, land application and incineration. Anaerobic sludge digestion is a technology employed worldwide to reduce solids, stabilize organic matter, and destroy pathogens and to produce biogas as a source of energy.Compositing is applied for sludge treatment and conversion of complex biowaste into a stabilized product that can be used as organic fertilizer in agriculture. In this paper we present the main practices employed in the management of wastewater sludge, in order to reduce its volume, to capitalize it and to protect the environment

RESEARCH ON HOUSEHOLD COMPOSTING EQUIPMENT USED FOR PROCESSING ORGANIC WASTE

Organic waste management is a great challenge for authorities in the context of the continuous increase of the quantities annually generated. When is brought to the municipal separation and treatment stations, the organic waste is highly contaminated and difficult to process, therefore one of the best management solutions is considered the treatment at source, using specialized household composting equipment. This paper proposes to analyze the main characteristics of household composters, emphasizing the advantages and disadvantages of this treatment technique

THERMOCHEMICAL CONVERSION TECHNOLOGIES FOR PRODUCING BIOFUELS FROM AGRICULTURAL BIOMASS

Biomass generated as residue from various agricultural activities is a renewable resource for producing energy, being available in abundant quantities and having low negative impact on environment quality. Biomass can be converted to biofuel using different thermal, biological and physical processes, however these technologies are not yet fully developed, to be able to successfully replace the classic sources of energy production. In this paper, will be assessed the main technologies for converting biomass into biofuels, exploring the physical and chemical characteristics of energy potential from agricultural biomass sources