Apparently mundane, amorphous nanostructures of carbon have optical properties which are as exotic as their crystalline counterparts. In this work we demonstrate a simple and inexpensive mechano-chemical method to prepare bulk quantities of self-passivated, amorphous carbon dots. Like the graphene quantum dots, the water soluble, amorphous carbon dots too, exhibit excitation-dependent photoluminescence with very high quantum yield (~40%). The origin and nature of luminescence in these high entropy nanostructures are well understood in terms of the abundant surface traps. The photoluminescence property of these carbon dots is exploited to detect trace amounts of the nitro-aromatic explosive — 2,4,6-trinitrophenol (TNP). The benign nanostructures can selectively detect TNP over a wide range of concentrations (0.5 to 200 µM) simply by visual inspection, with a detection limit of 0.2 µM, and consequently outperform nearly all reported TNP sensor materials.

Governance, Institutional quality, Economic growth, O17, O47, P14,

S evere fever with thrombocytopenia syndrome (SFTS) is an emerging tickborne disease caused by the SFTS virus (SFTSV; genus Banyangvirus, family Phenuiviridae, order Bunyavirales). The disease is prevalent in East Asia countries. It was first detected in China in 2009 and later in Japan and South Korea (1) and is suspected to be widely spread across other parts of the world (2). The recent identification of SFTSV in Xinjiang, China (3), expanded our awareness of epidemic areas of SFTS and suggested the possibility of SFTSV spreading to bordering countries like Pakistan. However, the presence of SFTSV in Pakistan has been unclear. We investigated the seroprevalence of SFTSV in humans in Pakistan. The Study For this study, we randomly collected human serum samples (n = 1,657) from 4 provinces in Pakistan during 2016-2017 (Figure). All participants were farmers of livestock (sheep, goats, cattle, buffaloes, and camels). We recorded and summarized testing results by sex, age, and geographic location (Table). The collection of human serum samples and subsequent tests were reviewed and approved by the Ethics Committees of

The detailed features of the design of a sampling tube, such as area ratio, inside clearance, cutting edge taper angle, etc., have an important influence on the disturbance caused when a tube sampler is pushed into cohesive soil. Currently, most tube sampler designs have evolved on the basis of empirical design rules, and local good practices, developed for particular soil conditions. The strain path method provides a basis upon which the influence and importance of different features of tube sampler design can be evaluated, and the design of future samplers optimized. This paper examines the use of Baligh's strain path method for the assessment of tube sampling disturbance, and implements the method via a finite-element approach to assess the influence of area ratio, cutting-edge angles and inside clearance, on sample disturbance evaluated on the basis of the strains imposed on the centre-line of a soil sample. Les caractéristiques précises du modèle de tube d'échantillonnage, comme le rapport de section, le jeu interne, l'angle de cône du bord coupant, etc., ont une influence prépondérante sur la perturbation causée par Penfoncement d'un échantillonneur à tubes dans un sol cohérent. A heure actuelle, la plupart des modèles d'échantillonneur à tubes sont conçus a partir de r6gles de calcul empiriques et de pratiques locales adaptées au conditions de terrain particulières. La méthode des courbes de contrainte fournit un moyen permettant d'une part, d'évaluer l'influence et l'importance des diff&entes caractéristiques du modèle d'échantillonneur à tubes et d'autre part, d'optimiser le dimensionnement des futurs échantillonneurs. Ce papier expose utilisation de la méthode des courbes de contrainte de Baligh pour étudier la perturbation de l'échantillonnage tubulaire, et décrit la méthode à é1éments finis mise en oeuvre pour évaluer l'influence du rapport de section, des angles de bord coupant et du jeu interne, sur la perturbation de l'échandllon évaluée en s'appuyant sur les contraintes impos&aucte;es sur l'axe d'un &aucte;chantilIon de sol.

Excitation-dependent, multicolor emission from different varieties of 0D carbon systems have attracted immense research attention. It is generally accepted that some variants of 0D carbon exhibit excitation dependent emission, while...

No abstract

Nitrogen-functionalized graphene quantum dots embedded in a polyaniline matrix (NGQD–PANI) are extremely promising candidates for the development of next-generation sensors and for thermoelectric materials design with the distinct advantage of tunability of electronic properties by controlled doping and/or by controlling the inherent disorder in the microstructure. While their application is increasing in photovoltaics, energy storage, and sensing technologies, a clear understanding of conduction in these hybrid systems is lacking. Here, we report a comprehensive study of NGQD–PANI composites with varying NGQD doping levels over a wide range of temperature. We show distinct regimes of conduction as a function of temperature, which include: a transition from Efros–Shklovskii and Larkin–Khmelnitskii variable range hopping at low temperatures to thermally driven electron transport at higher temperatures. Importantly, we find a remarkable 50-fold enhancement in conductivity for 10% NGQD-doped samples and tunability of the crossover temperature between different regimes as a function of the applied voltage bias and doping. Our work provides a general framework to understand the interplay of extrinsic parameters like temperature and voltage bias with intrinsic material properties like doping, which drives the electronic properties in these hybrid systems of technological importance.

No abstract