Scaling Law for Electrospray Droplet Formation

There has been a lot of research on liquid atomization by means of electrospray, particularly because of its many practical applications. Nevertheless, full understanding and control of the electrospray mechanisms are still incomplete. An experimental setup was developed in order to investigate the frequency characteristics of droplet formation and ejection at the tip of Taylor's cone of aqueous electrosprays. Droplet formation and oscillations were monitored using a Kodak Ektapro high-speed camera. The frequency of droplet formation at the tip of the capillary needle was analyzed. Droplet frequency formation appears to exhibit three distinct regimes with an abrupt transition from one regime to another. Droplet formation was recorded at different needle-plate electrode distances. Based on the analysis of experimental data a scaling law for droplet formation was found.     

Investigating the implications of extending synchronized sequencing in automotive supply chains: the case of suppliers in the European automotive sector

In recent years automakers have paid considerable attention to synchronizing supply chain material flow. Potential benefits associated with synchronization include stability in both demand and supply patterns, inventory reduction, elimination of demand amplification and better long-term planning. In major European production sites, the geographic proximity of suppliers to the vehicle assembly plants provided the motivation for examining the feasibility of extending the synchronized sequenced delivery of components upstream in the vehicle supply chain. The value stream used in the research concerned the seating systems at two major European production sites. The results of extending synchronized sequencing from the first to the second tier showed a reduction in demand amplification to negligible levels, achieved overall synchronization levels of 99–100% and considerably reduced overall pipeline inventory between the vehicle assembly plant and the second tier component supplier. The findings suggest how the geographic proximity of suppliers can be used to implement multi tier synchronized sequencing of components to improve supply chain performance. Based on the results of the study a series of recommendations are provided concerning the supply chain implications of multi tier synchronized sequencing.     

World fertilizer nutrient reserves: a view to the future

The increasing need for food production in subtropical regions likely translates to a need for additional plant nutrients. As a consequence, knowledge of world fertilizer nutrient reserves is of particular relevance to sustainable agriculture in the subtropics. The stewardship responsibilities of agriculture include the wise use of the raw materials from which commercial fertilizers are produced. Development and implementation of fertilizer best management practices with focus on the 4Rs-right source, right rate, right time, right place-are timely not only for short-term economic and environmental reasons, but also for the wise stewardship of the non-renewable nutrient resources upon which food, feed, fiber, and fuel production depend.     

The use of dihydrazides as latent curing agents in diglycidyl ether of bisphenol A coatings

Dihydrazides of different structure were synthesized and tested as curing agents for DGEBA epoxy coatings. By calorimetric studies their latent characteristics were proved and the kinetics of the curing studied. The temperatures of activation are usually dependant on the melting point of the dihydrazide. The acceleration by base and Lewis acids was proved, but the latent character was diminished. FTIR/ATR allowed characterizing the final structures of the thermosets and confirming that the fully cured was achieved. The thermal stability of the materials and their thermomechanical characteristics were evaluated by TGA and DMTA, respectively. Mechanical properties of the thermosets were also determined.     

Absorbance and fluorometric sensing with capillary wells microplates

Detection and readout from small volume assays in microplates are a challenge. The capillary wells microplate approach [Ng et al., Appl. Phys. Lett. 93, 174105 (2008)] offers strong advantages in small liquid volume management. An adapted design is described and shown here to be able to detect, in a nonimaging manner, fluorescence and absorbance assays minus the error often associated with meniscus forming at the air-liquid interface. The presence of bubbles in liquid samples residing in microplate wells can cause inaccuracies. Pipetting errors, if not adequately managed, can result in misleading data and wrong interpretations of assay results; particularly in the context of high throughput screening. We show that the adapted design is also able to detect for bubbles and pipetting errors during actual assay runs to ensure accuracy in screening.     

Critical evaluation of the indentation data analyses methods for the extraction of isotropic uniaxial mechanical properties using finite element models

Two different definitions of indentation strain and two different definitions of contact radius are being used in the current literature, leading to inconsistent estimates of mechanical properties (especially plastic properties). In this paper, we critically evaluate the validity of the different definitions of both the indentation strain and the contact radius by applying the protocols on datasets generated from a finite element simulation of spherical indentation. The finite element models allow assignment of a wide range of elastic–plastic properties to the sample while circumventing many of the uncertainties faced in experimental investigations, and thereby offer unique opportunities for critical validation of the different data analysis procedures. In particular, we are able to establish important connections between the indentation stress–strain curves and the conventional uniaxial stress–strain curves.     

Thermophoresis particle deposition in natural convection over inclined surfaces in porous media

The present paper is focused on the analysis of heat and mass transfer in boundary-layer free convection over an inclined flat plate embedded in a fluid saturated porous medium in the presence of thermophoresis. The governing equations are transformed into a set of coupled differential equations, which are solved numerically using the local non-similarity method. A comparison between the results given by this method and the local similarity method is also presented. For various values of the problem parameters, graphs of thermophoretic wall velocity, Nusselt number and concentration profiles in the boundary layer are presented. Variation of the dimensional thermophoretic wall velocity along the plate for different angles of inclination are presented in a physical relevant case.     

Organokines in Rheumatoid Arthritis: A Critical Review

Rheumatoid arthritis (RA) is a systemic autoimmune disease that primarily affects the joints. Organokines can produce beneficial or harmful effects in this condition. Among RA patients, organokines have been associated with increased inflammation and cartilage degradation due to augmented cytokines and metalloproteinases production, respectively. This study aimed to perform a review to investigate the role of adipokines, osteokines, myokines, and hepatokines on RA progression. PubMed, Embase, Google Scholar, and Cochrane were searched, and 18 studies were selected, comprising more than 17,000 RA patients. Changes in the pattern of organokines secretion were identified, and these could directly or indirectly contribute to aggravating RA, promoting articular alterations, and predicting the disease activity. In addition, organokines have been implicated in higher radiographic damage, immune dysregulation, and angiogenesis. These can also act as RA potent regulators of cells proliferation, differentiation, and apoptosis, controlling osteoclasts, chondrocytes, and fibroblasts as well as immune cells chemotaxis to RA sites. Although much is already known, much more is still unknown, principally about the roles of organokines in the occurrence of RA extra-articular manifestations.     

Ein einfacher Syntheseweg zu Lösungsmittel‐ stabilisierten Metallnanopartikeln und ihre Anwendung in der Hydrierung

By using a dedicated solvent and an appropriate metal precursor species, it is possible to build stable nanoparticle solutions in a fast and effective way. These solutions can be simply used in chemical reactions directly as a catalyst solution. With different transition metal species and solvents of variable polarity and density, a great number of catalytic reactions can be carried out. The catalyst can easily be recycled and, depending on the selection of the catalytic system, the solutions were stable over months.