353 research outputs found
Notes on interesting scythridids in the Zoological Museum, Helsinki, Finland (Lepidoptera, Scythrididae)
In this paper 28 species of the family Scythrididae from Asia and Africa are treated, six of which are described as new species, viz. Scythris felesella sp. n., S. kailai sp. n., S. kullbergi sp. n., S. kyzylensis sp. n., S. subcassiterellasp.n. and S. terekholensis sp. n. Most of the specimens were collected during expeditions made by members of the staff of the Zoological Museum in Helsinki. Genitalia not illustrated before are described, the distribution range ofeach species treated is given and some other experiences are presented
Notes on Palaearctic scythridids, with descriptions of nine new species (Lepidoptera: Scythrididae)
Nine new species of the microlepidopteran family Scythrididae from the Palaearctic region are described: Enolmis tunisiae sp.n., Scythris deprinsi sp. n., Scythris divergens sp. n., S. kaschmirica sp.n., S. linnavuorii sp.n., S. nepalensis sp. n., S. shafferi sp. n., S. tuzensis sp. n. and S. unguicella sp. n. Information on geographical distribution is given for some species recorded for the first time from various countries
Trade Union Cooperation in the EU: Views Among Swedish Trade Unions and Their Members
This article compares views among Swedish trade unions with those of their members regarding cross-national union cooperation in Europe or the EU. Data are derived from two different surveys, one among trade unions in 2010–2011 and the other among employees in 2006. It turns out that trade unions are generally more affirmative than their members to transnational union cooperation. In the employee survey, differences appear between members of the three peak-level organizations—the LO (manual workers), the TCO (white-collar workers), and Saco (professionals). However, controlling for education, these differences cannot be verified statistically. Higher education—which above all Saco members have—is linked to more positive attitudes toward transnational union cooperation. The gap between the organizations and their affiliates concerning engagement in European issues appears to be larger in the LO than in Saco, with the TCO somewhere in the middle
Energy reduction of stochastic time-constrained robot stations
This paper looks at the problem of reducing the energy use of robot movements in a robot station with stochastic execution times, while keeping the productivity of the station. The problem is formulated as a stochastic optimization problem, that constrains the makespan of the station to meet a deadline with a high probability. The energy use of the station is a function of the execution times of the robot operations, and the goal is to reduce this energy use by finding the optimal execution times and operation order. A theoretical motivation to why the stochastic variables in the problem, under some conditions, can be approximated as independent and normally distributed is presented, together with a derivation of the max function of stochastic variables. This allows the stochastic optimization problem to be approximated with a deterministic version, that can be solved with a commercial solver. The accuracy of the deterministic approximation is evaluated on multiple numerical examples, which show that the method successfully reduces the energy use, while the deadlines of the stations are met with high probabilities
Non Destructive Detection of Decay in Living Trees
It is shown that four point resistivity measurements can be used to detect decay in living trees. A low frequency alternating current is injected into the trunk and the induced voltage is measured between two points along the trunk. With additional measurement of the cross section area, the effective resistivity of the trunk is estimated. A comparison within a group of trees shows that trees in decay have approximately a factor of two lower effective resistivity than sound trees. The method is tested on several different groups of spruce (Picea abies); in total more than 300 trees are examined. The tests show that the method can detect decay caused by Heterobasidion annosum with high accuracy. Finite element modeling and simulations are used to validate the method
Structure of the Natural Transgene PgiC2 in the Common Grass Festuca ovina
BACKGROUND: A horizontal gene transfer has brought an active nuclear gene, PgiC2, from a polyploid Poa species (P. palustris or a close relative) into the common grass sheep's fescue (Festuca ovina). The donor and the receptor species are strictly reproductively separated, and PgiC2 occurs in a polymorphic state within F. ovina. The active gene copy is normally closely linked to a very similar pseudogene. METHODOLOGY/PRINCIPAL FINDINGS: By genome walking we have obtained the up- and downstream sequences of PgiC2 and of corresponding genes in the donor and recipient species. Comparisons of these sequences show that the complete upstream region necessary for the gene's expression is included in the transferred segment. About 1 kb upstream of PgiC2 a fragment with transposition associated properties has been found (TAF). It is present in P. palustris and its polyploid relatives, though not at the homologous position, and is absent from many other grasses, including non-transgenic F. ovina plants. It is possible that it is a part of a transposing element involved in getting the gene into a transferring agent and/or into the recipient chromosome. CONCLUSIONS/SIGNIFICANCE: The close similarity of the up- and downstream regions with the corresponding regions in P. palustris excludes all suggestions that PgiC2 is not a HGT but the result of a duplication within the F. ovina lineage. The small size of the genetic material transferred, the complex nature of the PgiC2 locus, and the associated fragment with transposition associated properties suggest that the horizontal transfer occurred via a vector and not via illegitimate pollination
A revision of the Elachista regificella Sircom -complex (Lepidoptera: Elachistidae)
The Elachista regificella complex (Elachistidae) is revised and considered to consist of three closely related species: E. regificella Sircom, presently only recorded from Great Britain, E. geminatella (Herrich-Schäffer), stat. rev. (= E. nieukerkeni Traugott-Olsen, syn. nov.) and E. tengstromi nom. nov. (= E. magnificella Tengström, 1848, nec Duponchel, 1843). The latter two species are widely distributed e.g. in Central Europe, the range of E. tengstromi extending to Japan. The species are diagnosed and illustrated. Life history records indicate that the species have, at least to some extent, different host plant preferences: Luzula sylvatica is recorded as the host plant of E. regificella and E. geminatella, of which the latter probably exploits other host plants as well. L. pilosa is the only known host plant of E. tengstromi in Europe, with further host plants recorded in Japan. Neotypes are designated for Elachista regificella Sircom and Poeciloptilia geminatella Herrich-Schäffer
Reduced-order synthesis of operation sequences
In flexible manufacturing systems a large number of operations need to be coordinated and supervised to avoid blocking and deadlock situations. The synthesis of such supervisors soon becomes unmanageable for industrial manufacturing systems, due to state space explosion. In this paper we therefore develop some reduction principles for a recently presented model based on self-contained operations and sequences of operations. First sequential operation behaviors are identified and related operation models are simplified into one model. Then local transitions without interaction with other operation models are removed. This reduction principle is applied to a synthesis of non-blocking operation sequences, where collisions among moving devices are guaranteed to be avoided by a flexible booking process. The number of states in the synthesis procedure and the computation time is reduced dramatically by the suggested reduction principle
Control of Homogeneous Charge Compression Ignition (HCCI) Engine Dynamics
The Homogeneous Charge Compression Ignition (HCCI) combustionconcept lacks direct ignition timing control, instead the autoignition depends on the operating condition. Since auto ignition of ahomogeneous mixture is very sensitive to operating conditions, a fastcombustion timing control is necessary for reliable operation. Hence,feedback is needed and the crank angle of 50% burnt (CA50) has provedto be a reliable feedback indicator of on-going combustion inpractice. CA50 or other methods for detecting on-going cylinderpressure used in the feedback control of a HCCI engine all rely onpressure sensors. This paper presents a newcandidate for control of HCCI engine by using the electronicconductive properties in the reaction zone. This phenomenon is calledion current. This paper perform combustion timing control based on ioncurrent and compare it with control based on pressure sensor. Thecombustion timing control is performed on cycle-to-cycle basis and the engine is a one-cylinder version of a heavy duty engine equipped with a port injection system using dual fuels
Planning transport sequences for flexible manufacturing systems
When designing a manufacturing system it is important to plan what the system
should do. One important activity in most manufacturing systems is to transport products or
resources between different positions. In a flexible manufacturing system it can be challenging
to design and plan these transport operations due to their complex logical behavior. This paper
presents a method that identifies, creates and visualizes these transport operations based on
inputs from a standard virtual manufacturing tool and a high level product operation recipe.
The planning of the created transport operations is transformed into a problem of finding a
non-blocking solution for a discrete model of the product refinement
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