The use of plant viruses as bioherbicides represents a fascinating and promising frontier in modern agriculture and weed management. This review article delves into the multifaceted world of harnessing plant viruses for herbicidal purposes, shedding light on their potential as eco-friendly, sustainable alternatives to traditional chemical herbicides. We begin by exploring the diverse mechanisms through which plant viruses can target and control weeds, from altering gene expression to disrupting essential physiological processes. The article highlights the advantages of utilizing plant viruses, such as their specificity for weed species, minimal impact on non-target plants, and a reduced environmental footprint. Furthermore, we investigate the remarkable versatility of plant viruses, showcasing their adaptability to various weed species and agricultural environments. The review delves into the latest advancements in genetic modification techniques, which enable the engineering of plant viruses for enhanced herbicidal properties and safety. In addition to their efficacy, we discuss the economic and ecological advantages of using plant viruses as bioherbicides, emphasizing their potential to reduce chemical herbicide usage and decrease the development of herbicide-resistant weeds. We also address the regulatory and safety considerations associated with the application of plant viruses in agriculture. Ultimately, this review article underscores the immense potential of plant viruses as bioherbicides and calls for further research, development, and responsible deployment to harness these microscopic agents in the ongoing quest for sustainable and environmentally friendly weed management strategies.

Plasma thermal gasification can be one of the most relevant and environmentally friendly technologies for waste treatment and has gained interest for its use in thethermos-conversion of biomass. In this perspective, the objective of this study is to evaluate the gasification of sugarcane bagasse by studying the effective areas of operation of this process and to establish a comparison with conventional autothermal gasification. A thermochemical equilibrium model was used to calculate the indicators that characterize the performance of the process on its own and integrated with a combined cycle. As a result, it was obtained that plasma and gasification of bagasse is technically feasible for the specific net electrical production of 4 MJ with 30 % electrical efficiency, producing a gas with higher calorific value than autothermal gasification. The operating points where the electrical energy production and the cold gas efficiency reach their highest values were determined; then the effects of the operational parameters on these performance indicators were analyzed.

Heat recovery is one of the measures proposed for the appropriate use of ammonia in tropical countries. This article analyzes a heat recovery system installed in an industrial refrigeration plant. Based on comparative readings of operating parameters of the installation, determined the effectiveness of the heat exchange, the increase in the efficiency of the refrigeration system, as well as the fuel saved by heating water in the industry. The results obtained reported that the thermal design based on heat exchange in annular spaces allows a significant saving of resources and a high rate of thermal utilization.

This paper uses Public Choice analysis to examine the case for and experience with Public-Private Partnerships (PPPs). A PPP is a contractual platform which connects a governmental body and a private entity. The goal is to provide a public sector program, service, or asset that would normally be provided exclusively by a public sector entity. This paper focuses on PPPs in developed countries, but it also draws on studies of PPPs in developing countries. The economics literature generally defines PPPs as long-term contractual arrangements between a public authority (local or central government) and a private supplier for the delivery of services. The private sector supplier takes responsibility for building infrastructure components, securing financing of the investment, and then managing and maintaining this facility.

However, in addition to those formed through contracts, PPPs may take other forms such as those developed in response to tax subvention or coercion, as in the case of regulatory mandates. A key element of PPP is that the private partner takes on a significant portion of the risk through a schedule of specified remuneration, contingency payments, and provision for dispute resolution. PPPs typically are long-term arrangements and involve large corporations on the private side, but may also be limited to specific phases of a project.

The types of PPPs discussed in this paper exclude arrangements which may result from government mandates such as the statutory emission mandates imposed on automobile manufacturers and industrial facilities (e.g., power plants). It also excludes PPP-like organizations resulting from US section 501(c)(3) of the Internal Revenue Code, which provides tax subsidies for certain public charities, scientific research organizations, and organizations whose goals are to prevent cruelty to animals or erect public monuments at no expense to the government. This paper concludes that an array of Public Choice tools are applicable to understanding the emergence, success, or failure of PPPs. Several short case studies are provided to illustrate the practicalities of PPPs.