A new vernal species of Hesperapis from the lower Midwestern United States (Hymenoptera: Melittidae)

A new species of vernal Hesperapis Cockerell (Melittidae: Dasypodainae: Hesperapini) is described and figured from localities spanning Texas, Oklahoma, and southern Kansas in the United States. Hesperapis (Carinapis) infuscata Engel & Michez, new species, is distinguished from its relatives in subgenus Carinapis Stage and particularly the carinata species group, to which it belongs.  The species is most notable for the apically infuscate wings and is possibly specialized (broadly oligolectic) on Gaillardia Foug., Helianthus L., Ratibida Raf., and Rudbeckia L. (Asteraceae).

Validation of some species- and genus-group names in Melitta (Hymenoptera: Melittidae)

Four recently proposed names in the genus Melitta Kirby (Melittidae: Melittinae) were left as nomenclaturally unavailable owing to minor conflicts with the recently established criteria for electronic publication.  These oversights are here corrected, thereby validating the following new names: Melitta (Afromelitta) Michez & Kuhlmann, new subgenus; Melitta (Afromelitta) richtersveldensis Michez & Kuhlmann, new species; Melitta (Plesiomelitta) Michez & Kuhlmann, new subgenus; and M. (Plesiomelitta) avontuurensis Michez & Kuhlmann, new species

Supplementary note on the solitary bee fauna from the Suez Canal region of Egypt (Hymenoptera: Apoidea)

Previous surveys (2011–2013) of the bee fauna from the Suez Canal region, Egypt, recorded a total of 55 species.  Those surveys did not include important floral species among the Asteraceae, a family known to be associated with various oligolectic bees.  The aim of the present note is to report bees visiting four uncultivated species of Asteraceae that are common in the region during the Spring of 2014.  Nine species of bees were recorded from these flowers, these increasing the number of species recorded from the Suez Canal region to 62.  Some species, such as Daypoda sinuata Pérez (Melittidae) and Panurgus dentatus Friese (Andrenidae), are known oligoleges of Asteraceae.

Electrical and optical measurements of the bandgap energy of a light-emitting diode

International audienceSemiconductors materials are at the basis of electronics. Most electronic devices are made of semiconductors. The operation of these components is well described by quantum physics which is a little mysterious to students. One of the intrinsic parameters of semiconductors is their bandgap energy Eg. In the case of light-emitting diodes (LEDs) Eg fixes the colour of the light emitted by the diodes. We propose in this article a lab work allowing a comparison of Eg of a green LED obtained by both electrical and optical measurements. The two slightly different results can be explained by the theoritical knowledges of the students on solid physics and electronic devices internal architecture

An introduction to photocatalysis through methylene blue photodegradation

International audienceWe described a simple experimental setup for a lab work on the photocatalytic degradation of methylene blue by T iO 2 nanoparticles. The photocatalysis process can be used for many applications. Treatments for diluted wastewaters industries, air purifying in underground car parks, preventing fouling on glass surfaces, these are some of the things this phenomenon has the ability to do. The described experiment is easy to perform and the interpretation can be easily adapted to different level of students: from high school students demonstrating their interests on a sustainable development, to students who are getting Masters in the science department that want to propose a full explanation of all the phenomenon of the photocatalytic process. Starting by a description of the experimental setup , we analysed the photocatalyst nanoparticles and applied the Langmuir-Hinshelwood model to our experimental data. Finally we discussed shortly on the respective energetic levels of the photocatalyst semiconductor and the methylene blue

New records of bees (Hymenoptera: Apoidea) from the Maltese Islands

A total of 95 bee species have been recorded from the Maltese Islands (central Mediterranean Sea).  The aim of the present note is to report newly recorded species within the study area.  A total of nine new species belonging to four families are recorded here: Andrenidae (1 species), Apidae (1 species), Halictidae (5 species), and Megachilidae (2 species)

Mn5Ge3C0.6/Ge(111) Schottky contacts tuned by a n-type ultra-shallow doping layer

International audienceMn 5 Ge 3 Cxcompound is of great interest for spintronics applications. 10 The various parameters of Au/Mn 5 Ge 3 C 0.6 /Ge(111) and Au/Mn 5 Ge 3 C 0.6 /δ-doped Ge(111) Schottky diodes were measured in the temperature range of 30-300 K by using current-voltage and capacitance-voltage techniques. The Schottky barrier heights and ideality factors were found to be temperature dependent. These anomaly behaviours were explained by Schottky barriers inhomogeneities 15 and interpreted by means of Gaussian distributions model of the Schottky barrier heights. Following this approach we show that the Mn 5 Ge 3 C 0.6 /Ge contact is described with a single Gaussian distribution and a conduction mechanism mainly based on the thermoionic emission. On the other hand the Mn 5 Ge 3 C 0.6 /δ-doped Ge contact is depicted with two Gaussian distributions according to the 20 temperature and a thermionic-field emission process. The differences between the two types of contacts are discussed according to the distinctive features of the growth of heavily doped germanium thin films

Book review: The Bumblebees of the Himalaya – An Identification Guide, by Paul H. Williams

Book review: The Bumblebees of the Himalaya – An Identification Guide, by Paul H. William