Standardization of surface potential measurements of graphene domains

We compare the three most commonly used scanning probe techniques to obtain a reliable value of the work function in graphene domains of different thickness. The surface potential (SP) of graphene is directly measured in Hall bar geometry via a combination of electrical functional microscopy and spectroscopy techniques, which enables calibrated work function measurements of graphene domains with values ~4.55+/-0.02 eV and ~4.44+/-0.02eV for single- and bi-layer, respectively. We demonstrate that frequency-modulated Kelvin probe force microscopy (FM-KPFM) provides more accurate measurement of the SP than amplitude-modulated (AM)-KPFM. The discrepancy between experimental results obtained by different techniques is discussed. In addition, we use FM-KPFM for contactless measurements of the specific components of the device resistance. We show a strong non-Ohmic behavior of the electrode-graphene contact resistance and extract the graphene channel resistivity

Les pavillons russes aux Expositions Universelles du XIXe siècle: expression de l’identité qui n’a jamais existé

La Russie a pris part presque à toutes les Expositions Universelles de la deuxième moitié du XIXe siècle. Elle a commencé par les sections du bâtiment principal, puis elle a élargi sa présence aux expositions avec des édifices thématiques et de grands pavillons nationaux. La réaction des visiteurs de ces Expositions influençait l’établissement de l’esthétique particulière des pavillons russes suivant le style folklorique. Ils créent l’idée de la Russie fausse au fond mais intéressante et familière aux Européens, celle du pays oriental et préindustriel.La Russia ha partecipato a quasi tutte le esposizioni universali della seconda metà del XIX secolo. Partendo con le sezioni dell’edificio principale, ha poi ampliato la propria presenza nelle mostre con edifici di alta qualità e grandi padiglioni nazionali. La reazione dei visitatori di questi spettacoli ha influenzato la definizione della particolare estetica dei padiglioni russi secondo uno stile folklorico. Tali costruzioni creano un’idea fasulla della Russia, ma interessante e familiare agli Europei: quella di un paese orientale e preindustriale.Russia took part almost in all World Exhibitions of the second half of the 19th century. Starting with sections in the central exhibition hall, it gradually expanded its presence at exhibitions at the expense of separate thematic buildings and big national pavilions. The special design of Russian pavilions in their national style was created under the influence of visitors’ opinion. They propagated a false yet interesting and habitual European image of Russia, as the eastern and preindustrial country

Private Colleges, State Aid, and the Establishment Clause

Using local scanning electrical techniques we study edge effects in side-gated Hall bar nanodevices made of epitaxial graphene. We demonstrate that lithographically defined edges of the graphene channel exhibit hole conduction within the narrow band of similar to 60-125 nm width, whereas the bulk of the material is electron doped. The effect is the most pronounced when the influence of atmospheric contamination is minimal. We also show that the electronic properties at the edges can be precisely tuned from hole to electron conduction by using moderate strength electrical fields created by side-gates. However, the central part of the channel remains relatively unaffected by the side-gates and retains the bulk properties of graphene.Funding Agencies|NMS under the IRD Graphene Project (NPL); EMRP</p

Indicators of Mineral Metabolism Depending on the Body Mass Index

n this study, the elemental status of the hair of adolescent girls in the Orenburg region (n=120) with different levels of body mass index was studied and their average daily diet was evaluated. A nutrition assessment program was used to study the diet. Estimation of the element status was carried out through the study of the chemical composition of the hair by ICP-AES and ICP-MS. It was found that there was a general imbalance of elements in the diet of all of the studied groups, and students with obesity had lower consumption levels of all elements, except Mg and Se. Similarly, obese students had lower levels of all elements in their hair except Se, P, and Zn. Thus, changes in the level of body mass index, as well as geochemical features of the territory of the Orenburg region, affect the content of most macro- and microelements. Keywords: metabolic syndrome, trace elements, body mass inde

Influence of the Indicators of Carbohydrate Metabolism on the Elemental Status

This study examined the elemental status of the hair and blood biochemistry of young men in the Orenburg region (n=38) with different glucose levels. Estimation of the element status was carried out through the study of the chemical composition of the hair by ICP-AES and ICP-MS. It was found that the studied serum parameters (Ca, Mg, Fe, P cholesterol, thyroxine, TSH and testosterone) were within normal values, and no statistically significant differences were obtained when comparing the groups. The concentration of chemical elements in the hair of the men in each group was in the range of physiologically acceptable values for this region. In the group with elevated glucose levels, there was a tendency for the men to have lower values of Ca and Mg, and higher levels of K, Na, P and a number of toxic elements (Al, Cd, Sn, Hg, Pb). Keywords: elemental status, trace elements, diabetes mellitus, metabolis