RESUMO
The economic evaluation of mastitis control is challenging. The objective of this study was to perform the economic evaluation of mastitis control, under different intervention scenarios, quantifying the total cost of mastitis caused by S. aureus in Holstein cows in Argentina. A model was set for a dairy herd of Holstein cows endemically infected with S. aureus. A basic mastitis control plan including proper milking procedures, milking machine test, dry cow therapy, and treatment for clinical mastitis, was compared against other more complex and costly interventions, such as segregation and culling of chronically infected cows. Sensitivity analysis was performed by modifying the intramammary infection transition probabilities, economic parameters, and efficacy of treatment strategies. The basic mastitis control plan showed a median total cost of USD88.6/cow per year, which was close to the infected cows culling scenarios outputs. However, the segregation scenario was the most efficient, in which the total cost was reduced by about 50%. Such cost was more sensitive to probabilities and efficacy than the economic parameters. The model is flexible and can be customized by producers and veterinarians according to different control and herd settings.
RESUMO
Abstract The urban transport electrification is going upward in many countries. However, this electrification faces many hurdles, among them, the limited range and cost that present-day electric vehicles (EV) have. This paper analyzes which Battery Electric Vehicles (BEV) could meet the current car travel needs in different uses. The results from a survey about distance travelled in daily trips in La Havana, allow the assessment of maximum average daily distance travel (MADT) by the private owners, cars in public service, taxis and leasing. The Lognormal distribution adjusts to MADT´s histogram in each group, and yields estimates characterizing its behavior. The use of a database of BEV with more than 60 electric vehicles allows to select an appropriate model for each use. The BEV´s range is normally expressed using several driving cycles, being EPA (Environmental Protection Agency) the most adequate, but the range by EPA is not always available. A regression analysis was made to obtain the EPA range as a function of range by others driving cycles. Finally, a Total Cost of Operation (TCOp) is calculated considering the purchase cost, energy cost, maintenance, etc. The outcomes are that for the private use, only small BEV with a strong subsidy or battery leasing can compete with an Internal Combustion Engine Vehicle (ICEV). In the public, taxis and leasing sector, the BEV are competitive in several years. The daily mileage and electricity cost are decisive. The use of renewable energy to charge batteries can reduce this period to some extent.
RESUMO
The reverse osmosis (RO) process has been increasingly applied to landfill leachate treatment. The published literature reports several studies that investigated the technical feasibility of RO. However, information about process costs is scarce. Also, companies that run leachate treatment plants do not provide actual costs. To fill this gap, this study aimed to evaluate the treatment costs of a full-scale RO for the treatment of landfill leachate located in Rio de Janeiro State, Brazil. A procedure was proposed to estimate the capital expenses (CAPEX), operational expenses (OPEX), and specific total treatment cost, the total cost per m3 of treated leachate, of the leachate treatment by membrane process, and the results obtained are discussed. The CAPEX for this full-scale RO was estimated at MUS$ 1.413, and OPEX ranged from US$ 0.132 to US$ 0.265 m-3 per year. The cost of leachate treatment has been estimated at US$ 8.58 m-3 considering the operation of the RO-unit for 20 years after landfill closure.