The blue crab (Callinectes sapidus), originally from the western Atlantic Ocean, has recently spread to the Mediterranean and is now considered one of the one hundred most invasive species in that region. This opportunistic species, known for its adaptability to different temperatures and salinities, negatively impacts biodiversity and human activities such as fishing and tourism in the Mediterranean. However, the blue crab is gaining interest as a potential food resource due to its high nutritional value and delicate, sweet flavor. Its meat is rich in protein (14% to 30%), omega-3 fatty acids (EPA and DHA) and other essential nutrients beneficial for human health such as vitamins, and minerals. Utilizing this species in the production of new foods could help mitigate the negative impact of its invasiveness and offer economic opportunities. One challenge with this potential resource is the generation of waste. Approximately 6–8 million tonnes of crab shells are produced worldwide each year, leading to disposal problems and concerns regarding environmental sustainability. To improve economic and environmental sustainability, there is a need to valorize these residues, which are an important source of proteins, lipids, chitin, minerals, and pigments that can be processed into high-value-added products. However, especially in areas with industrial pollution, attention should be paid to the heavy metal (Cd and As) contents of blue crab shells. Studies suggest that blue crab by-products can be used in various sectors, reducing environmental impacts, promoting a circular economy, and creating new industrial opportunities.
The authors conducted a comparative test to determine whether the introduction of a hydraulic slack puller allowed reducing the physiological workload of operators assigned to log winching tasks. The tests were conducted in northern Italy, on the mountains near Como. The study involved five volunteer subjects, considered representatives of the regional logging workforce. Physiological workload was determined by measuring the operators' heart rate upon completion of specific tasks. The slack puller improved the efficiency of downhill winching, since it allowed a single operator to pull out the cable on his own, without requiring the assistance of a colleague. However, introduction of the slack puller did not result in any reductions of operator physiological workload. The main stressor when working on a steep slope is moving up and down the slope: pulling a cable is only a secondary stressor. Any measures targeting secondary stressors are unlikely to produce dramatic reductions of operator workload.
The quality requirements of wood biofuels are regulated by a series of harmonized international standards. These standards define the technical parameter limits that influence the quality of solid biomass as a fuel. In 2014 the European reference standard for solid biofuel was replaced by the International ISO standard. In the case of wood chips, the main difference between the European and International standards is the definition of particle size distribution classes. In this context, this study analyses the quality of wood chips and its variation over the years according to the “former” (EN 14691-4) and “in force” (ISO 17225-4) standards. A Soft Independent Modelling of Class Analogy (SIMCA) model was built to predict the best quality of wood chips and to clarify the relationship between quality and standard parameters, time and changes in the standard regulations. The results show that, compared to the EN standards, classification with the ISO standards increases the samples belonging to the best quality classes and decreases the not classified samples. Furthermore, all the SIMCA models have a high sensitivity (>90%), reflect the differences introduced to the quality standards and are therefore suitable for monitoring the quality of wood chips and their changes.
This study presents the analysis of panel data on steep terrain logging productivity in Norway. Given the specification of a Cobb Douglas stochastic frontier production function in which the technical inefficiency is a function of six different environmental factors, it was found that only one (terrain hindrance) decreased the efficiency significantly. The estimated efficiencies for the sample crews ranged from 0.43 to 0.99. Because of the nature of the inefficiency factors, one way to improve the efficiency could be to train the crews for working on steep slopes. This would also improve the safety when exposing workers to these types of environmental hazards.
2 January 2014 in International Journal of Forest Engineering
This paper provides evidence of improvement in cable yarder operator proficiency through initial training on a controlled site. Five subjects were included in the study: one expert (as control), two with limited experience in operating similar machines, and two with no experience. A 1:3 scale tower-yarder modeled on the Owren 400 was used as a test rig. A wireless control with two joysticks, used individually and in combination, covered all yarder and carriage functionality. The time taken to individually yard five logs was measured and repeated six times over two days for each subject. Cable tension in the system was simultaneously monitored as an indicator of operating consistency. Evidence of a distinct learning curve was obtained through statistical analysis by applying mixed-effects models. The standard deviations of times and tensions of the limited-experience group rapidly emulated the profiles of the expert, and subjects in the no-experience group were comfortable with the operation of the yarder controls after the six trial replications. A reduction in initial large fluctuations in cable tension demonstrated the usefulness of training. On-the-job training with full-scale machines under similar conditions could have led to system failure, with possible breakage of the tail spar, guy lines or mainline and potential material loss and human injury.
4 September 2023 in Bio-based and Applied Economics
With a view to integration into the European Union, the efficiency and competitiveness of the Kosovo’ different sectors (including agriculture) must be improved. This paper assesses the technical efficiency (TE) of horticultural farms through Data Envelopment Analysis (DEA) applying output orientation. It was founded that the TE of these farms is positively affected by their size, with large-size farms presenting overall higher technical efficiency. The research findings indicate that the degree of agricultural education does not have a significant impact on TE, whereas public assistance through subsidies and grants has a substantial and negative impact on TE, as confirmed by statistical analysis.