Unimpeded permeation of water through helium-leak-tight graphene-based membranes

Permeation through nanometer pores is important in the design of materials for filtration and separation techniques and because of unusual fundamental behavior arising at the molecular scale. We found that submicron-thick membranes made from graphene oxide can be completely impermeable to liquids, vapors and gases, including helium, but allow unimpeded permeation of water (H2O permeates through the membranes at least 10^10 times faster than He). We attribute these seemingly incompatible observations to a low-friction flow of a monolayer of water through two dimensional capillaries formed by closely spaced graphene sheets. Diffusion of other molecules is blocked by reversible narrowing of the capillaries in low humidity and/or by their clogging with water

The Making of Cloud Applications An Empirical Study on Software Development for the Cloud

Cloud computing is gaining more and more traction as a deployment and provisioning model for software. While a large body of research already covers how to optimally operate a cloud system, we still lack insights into how professional software engineers actually use clouds, and how the cloud impacts development practices. This paper reports on the first systematic study on how software developers build applications in the cloud. We conducted a mixed-method study, consisting of qualitative interviews of 25 professional developers and a quantitative survey with 294 responses. Our results show that adopting the cloud has a profound impact throughout the software development process, as well as on how developers utilize tools and data in their daily work. Among other things, we found that (1) developers need better means to anticipate runtime problems and rigorously define metrics for improved fault localization and (2) the cloud offers an abundance of operational data, however, developers still often rely on their experience and intuition rather than utilizing metrics. From our findings, we extracted a set of guidelines for cloud development and identified challenges for researchers and tool vendors

Assessing online e-marketing and disposal in Neyveli Lignite Corporation Limited (India)

Marketing function per se is undergoing a shift in managing transaction in a transparent emarketing way (Kauffman et al, 2004) especially in Indian Public Sector Undertakings (PSU) – see Reynolds et al (2007). The effectiveness of e-marketing and disposal system of scrap and purchases in PSUs, namely NLC Ltd and ICF, have been studied. Factors such as e-auction offers, time of auction, experience, security deposit (EMD), basic rate per unit, allotment of bid, acceptance of bid; payment and delivery of successful bids on select items in two PSUs over a period of three to five years have been dealt with. The study adds strength to the concept of e-marketing as well as to the theory of marketing

Comparative study between open versus laparoscopic inguinal hernioplasty

Background: Inguinal hernia repair is one of the commonly performed procedure and has undergone a paradigm shift from open to laparoscopic approach in the era of minimally invasive surgery but the superiority is still debatable. The aim was to compare open (Lichtenstein) versus laparoscopic transabdominal preperitoneal approach (TAPP) hernia repair techniques. Methods: A total of 60 patients were enrolled in the study and divided into two equal groups (open versus laparoscopic) were compared. Results: It was observed that laparoscopic repair (TAPP) has statistically significant superiority than open inguinal hernioplasty in terms of lesser post-operative pain (VAS score of 4.8±0.66, 3.67±0.66, 2.53±0.82 versus 6.7±0.92, 5.03±0.72, 3.83±0.65 at 24 hours, 48 hours and 72 hours post operatively, p value <0.001), shorter duration of hospital stay (3.1±0.71 days versus 5.83±0.75 days, p value <0.001) and early resumption to regular activities (10.57±2.28 days versus 12.2±1.52 days, p value 0.002). It also showed that incidence intra operative and post-operative complications was lesser in laparoscopic group but not statistically significant. Whereas duration of surgery was prolonged in laparoscopic group (104±27.49 min versus 61.5±17.08 min, p value <0.001). Conclusions: Laparoscopic inguinal hernioplasty (TAPP) is superior to open inguinal hernioplasty in terms of lesser intra operative and post-operative complications, lesser post-operative pain, shorter duration of hospital stay with early resumption to regular activities having better subjective and objective cosmetic results in short term follow-up. However, duration of surgery was prolonged on comparison with Lichtenstein open inguinal hernioplasty

Conjugate 18cm OH Satellite Lines at a Cosmological Distance

We have detected the two 18cm OH satellite lines from the $z \sim 0.247$ source PKS1413+135, the 1720 MHz line in emission and the 1612 MHz line in absorption. The 1720 MHz luminosity is $L_{\rm OH} \sim 354 L_\odot$, more than an order of magnitude larger than that of any other known 1720 MHz maser. The profiles of the two satellite lines are conjugate, implying that they arise in the same gas. This allows us to test for any changes in the values of fundamental constants, without being affected by systematic uncertainties arising from relative motions between the gas clouds in which the different lines arise. Our data constrain changes in $G \equiv g_p [\alpha^2/y]^{1.849}$, where $y \equiv m_e/m_p$; we find $\Delta G/G = 2.2 \pm 3.8 \times 10^{-5}$, consistent with no changes in $\alpha$, $g_p$ and $y$.Comment: 5 pages, 1 figure. Minor changes to match published versio

DC Inclined-Plane Tracking and Erosion Test of Insulating Materials

The paper reviews previous work on the DC inclined plane test and suggests equivalent DC voltage levels in parallel to AC voltage in the ASTM inclined plane tracking and erosion test. The aim of this work is to provide a basis for standardizing the inclined plane test for DC voltage. Round robin tests done in five laboratories on five specimens of a silicone rubber material were done with the purpose of establishing appropriate ratios by which the equivalent DC voltages can be determined with respect to the corresponding AC voltages. These levels were determined as 67% and 87%, for +DC and-DC respectively, of the AC initial tracking voltage, and for practical purposes, these levels are rounded to 70 and 90%.Peer reviewed: YesNRC publication: Ye

Exploring the relationship between EMG feature space characteristics and control performance in machine learning myoelectric control

In myoelectric machine learning (ML) based control, it has been demonstrated that control performance usually increases with training, but it remains largely unknown which underlying factors govern these improvements. It has been suggested that the increase in performance originates from changes in characteristics of the Electromyography (EMG) patterns, such as separability or repeatability. However, the relation between these EMG metrics and control performance has hardly been studied. We assessed the relation between three common EMG feature space metrics (separability, variability and repeatability) in 20 able bodied participants who learned ML myoelectric control in a virtual task over 15 training blocks on 5 days. We assessed the change in offline and real-time performance, as well as the change of each EMG metric over the training. Subsequently, we assessed the relation between individual EMG metrics and offline and real-time performance via correlation analysis. Last, we tried to predict real-time performance from all EMG metrics via L2-regularized linear regression. Results showed that real-time performance improved with training, but there was no change in offline performance or in any of the EMG metrics. Furthermore, we only found a very low correlation between separability and real-time performance and no correlation between any other EMG metric and real-time performance. Finally, real-time performance could not be successfully predicted from all EMG metrics employing L2-regularized linear regression. We concluded that the three EMG metrics and real-time performance appear to be unrelated

A study on curcuminoid profile of Curcuma longa L. varieties as affected by processing method

An attempt was made to understand the variation in the curcuminoid profile of turmeric varieties. Eight cultivars namely, Local (check), IISR-Alleppey Supreme, IISR-Kedaram, IISR-Prabha, IISRPrathibha, Suvarna, Suguna and Sudharshana were utilized for the study. Curcuminoid content of fresh, dried and cured varieties after methanolic extraction and quantification through HPLC revealed that Local (check) turmeric in fresh form was significantly superior in curcuminoid content. IISR-Prabha and IISR-Prathibha in dry and cured form respectively, also exhibited high curcuminoid content. &nbsp

Turbulence measurements from HI absorption spectra

We use the millennium Arecibo 21 cm absorption-line survey measurements to examine the issue of the non-thermal contribution to the observed Galactic HI line widths. If we assume a simple, constant pressure model for the HI in the Galaxy, we find that the non-thermal contribution to the line width, v_{nt} scales as v^2_{nt} \propto l^{\alpha}, for v_{nt} larger than \sim 0.7 km s^{-1}. Here l is a derived length scale and \alpha \sim 0.7 \pm 0.1. This is consistent with what one would expect from a turbulent medium with a Kolmogorov scaling. Such a scaling is also predicted by theoretical models and numerical simulations of turbulence in a magnetized medium. For non-thermal line widths narrower than \sim 0.7 km s^{-1}, this scaling breaks down, and we find that the likely reason is ambiguities arising from Gaussian decomposition of intrinsically narrow, blended lines. We use the above estimate of the non-thermal contribution to the line width to determine corrected HI kinetic temperature. The new limits that we obtain imply that a significantly smaller (\sim 40% as opposed to 60%) fraction of the atomic interstellar medium in our Galaxy is in the warm neutral medium phase.Comment: 5 pages, 7 figures. Corrected typos. Accepted for publication in MNRAS Letters. The definitive version will be available at http://www.blackwell-synergy.co