Log Splitter Research Articles

Beneath the bark: associations among Sirex noctilio development, bluestain fungi, and pine host species in North America

1. Invasive species with global distributions encounter unique environmental and biotic variables that can greatly affect the magnitude of their impact. The European woodwasp, Sirex noctilio Fabricius, is a prime example that has invaded climatically and ecologically distinct ecosystems across the Southern Hemisphere and, more recently, North America.2. Northeastern North America presents a unique set of conditions, including pine host species, native parasitoids, a diverse assemblage of native co‐colonising insects, and fungal associates of these co‐colonisers. In North America, S. noctilio attacks both a naturalised ancestral host (Pinus sylvestris L.) from Europe and a naïve native host (P. resinosa). A large assemblage of insects and their associated bluestaining ophiostomatoid fungi colonise these pines. Competition between S. noctilio and this group is a hypothesised mechanism of biotic resistance in the invaded region of North America, possibly via superior resource capture abilities or alteration of host tissue by bluestain fungi.3. Investigating these ecological interactions is challenging because they manifest deep in the xylem tissue. To overcome this, 30 experimentally stressed trees were systematically dissected with an electric log splitter to investigate the effects of bluestain fungi and tree factors on S. noctilio development and parasitism by native hymenopterans.4. Body size and colonisation density were affected by pine species, with S. noctilio being 25% larger and densities three‐fold greater in P. sylvestris than P. resinosa. Survivorship was slightly negatively correlated with the proportional volume of bluestain infection. Interestingly, rhyssine (Rhyssa and Megarhyssa spp.) parasitism responded positively to greater S. noctilio density, but there was no density relationship with Ibalia leucospoides ensiger parasitism. Pine host species appears to play a strong role in S. noctilio development, which is important considering uninvaded regions of North America have a diversity of pine species that likely vary in their susceptibility to this woodborer.

Log Splitter Design and Construction

Heating by solid fuels, and especially fi re wood, belongs to the most asked and requested types of heating in cottages. One of the main problems of heating is wood splitting as a fi rst operation. A very useful tool for splitting of wood material is a log splitter. This contribution is focused on how to apply a screw type log splitter in wood splitting. A set of experiments have been realized to get an appropriate shape of the splitting cone, which will provide an improved splitting action. The cone has been manufactured on the basis of the experimental results. The experimental apparatus has been developed to determine the validity of the splitting cone and its geometry design.

Technical analysis and re-design of a screw log splitter: new methods of risk management

In the recent years, the proper design of agricultural machines for both professional and non-professional use has assumed a relevant role in workers protection and accident avoidance. The activities related to cutting and sawing of firewood is the main cause of injuries or death of the operator. This is often due to the use of inadequately built or modified machines, improper use of equipment and use of tools intended for other purposes. This study aimed to design a conical screw log splitter that meets the criteria of the European Directive 2006/42/EC and the technical standards of EN 609-2:1999+A1:2009(E) guideline. For a proper design we determined the forces that influence the machine during its use, and sized the machine accordingly. The log splitter was scanned and digitalized in three dimensions. From the digital model we obtained a real model in 5:1 scale. Comparing the created log splitter with other solutions available on the market we confirmed its similar costs with the costs of tools currently marketed. The productivity of the machine was only slightly lower than that of machines not equipped with protections, but its safety was significantly improved.

An accidental death when working with a screw log splitter. A case report

A case of the accidental death of a 42-year-old male injured by a screw log splitter in the yard of a private house necessitated a post-mortem examination and the technical evaluation of the machinery. The autopsy revealed fatal traumatic lesions to the head, caused by impact with a downward-moving log. Analysis of the scene of the accident showed that the machinery was not equipped with safety systems and was used incorrectly by the operators. The decision of the Criminal Court determined the absence of liability of the parties to be persecuted.

Combining Mathematical Programming and SysML for Automated Component Sizing of Hydraulic Systems

In this paper, we present a framework for automated component sizing to extend a designer's ability to evaluate a particular configuration during the architecture exploration phase of a design process. Component sizing is a hard problem to solve, both from a computational and modeling aspect. This is because of competing objectives, requirements from multiple disciplines, and the need to find a good solution quickly for the architecture being considered. In current approaches, designers rely on heuristics and iterate over the multiple objectives and requirements until a satisfactory solution is found. To improve on this state of practice, we introduce advances in the following two areas: (a) solving the problem efficiently so that all of the imposed requirements are satisfied simultaneously and the solution obtained is mathematically optimal and (b) modeling a component sizing problem in a manner that is convenient to designers. An acausal, algebraic, equation-based, declarative modeling approach using mathematical programming (GAMS) is taken to solve these problems more efficiently. The object management group systems modeling language (OMG SysML™) is used to model component sizing problems in order to facilitate problem formulation, model reuse and automatic generation of low-level code that can be solved using GAMS and its solvers. This framework is demonstrated by applying it to an example of a hydraulic log splitter. Based on this initial example, we discuss two advantages of this framework—total time taken in solving multiple scenarios for a given configuration and the graphical representation of a problem in SysML.

Compositional Modelling of Fluid Power Systems using Predictive Tradeoff Models

AbstractSystem-level decisions can have a large impact on the success of any design project, including those in the fluid power domain. Regardless of efforts by designers to optimize individual fluid power components, poor decisions at the systems level can lead to poor system performance and unsatisfied design requirements. In this paper, the principles of system-level decision making are applied to the design of fluid power systems. Describe a methodology for modelling fluid power component technology using predictive modelling and data mining techniques in a way that facilitates system-level modelling and decision making is described. This approach is demonstrated on the design of a hydraulic log splitter.

A review of log splitter safety

A wide range of log splitters is used in the UK, most of them are imported. This means an increase in the number of accidents with these machines caused mainly by bad design and incorrect use. Twenty-eight log splitters were investigated and many were demonstrated in use. The hazard areas were discussed with the operators and noted. A small number of reported accident cases are also studied. A summary of the main hazards involving the use and misuse of log splitters has been drawn up to aid future design and safe operations.