Understanding depletion forces beyond entropy

The effective interaction energy of a colloidal sphere in a suspension containing small amounts of non-ionic polymers and a flat glass surface has been measured and calculated using total internal reflection microscopy (TIRM) and a novel approach within density functional theory (DFT), respectively. Quantitative agreement between experiment and theory demonstrates that the resulting repulsive part of the depletion forces cannot be interpreted entirely in terms of entropic arguments but that particularly at small distances ($\lesssim$ 100 nm) attractive dispersion forces have to be taken into account

Sustainable cooling method for machining titanium alloy

Hard to machine materials such as Titanium Alloy TI-6AI-4V Grade 5 are notoriously known to generate high temperatures and adverse reactions between the workpiece and the tool tip materials. These conditions all contribute to an increase in the wear mechanisms, reducing tool life. Titanium Alloy, for example always requires coolant to be used during machining. However, traditional flood cooling needs to be replaced due to environmental issues, and an alternative cooling method found that has minimum impact on the environment. For true sustainable cooling of the tool it is necessary to account for all energy used in the cooling process, including the energy involved in producing the coolant. Previous research has established that efficient cooling of the tool interface improves the tool life and cutting action. The objective of this research is to determine the most appropriate sustainable cooling method that can also reduce the rate of wear at the tool interface

The National Clinical Assessment Tool for Medical Students in the Emergency Department (NCAT-EM)

Introduction: Clinical assessment of medical students in emergency medicine (EM) clerkships is a highly variable process that presents unique challenges and opportunities. Currently, clerkship directors use institution-specific tools with unproven validity and reliability that may or may not address competencies valued most highly in the EM setting. Standardization of assessment practices and development of a common, valid, specialty-specific tool would benefit EM educators and students. Methods: A two-day national consensus conference was held in March 2016 in the Clerkship Directors in Emergency Medicine (CDEM) track at the Council of Residency Directors in Emergency Medicine (CORD) Academic Assembly in Nashville, TN. The goal of this conference was to standardize assessment practices and to create a national clinical assessment tool for use in EM clerkships across the country. Conference leaders synthesized the literature, articulated major themes and questions pertinent to clinical assessment of students in EM, clarified the issues, and outlined the consensus- building process prior to consensus-building activities. Results: The first day of the conference was dedicated to developing consensus on these key themes in clinical assessment. The second day of the conference was dedicated to discussing and voting on proposed domains to be included in the national clinical assessment tool. A modified Delphi process was initiated after the conference to reconcile questions and items that did not reach an a priori level of consensus. Conclusion: The final tool, the National Clinical Assessment Tool for Medical Students in Emergency Medicine (NCAT-EM) is presented here. [West J Emerg Med. 2018;19(1)66-74.

Design of a wearable LED based device for phototherapy applications

Phototherapy with UV or visible wavelengths is used to treat skin disorders such as psoriasis, eczema and vitiligo. Traditionally, phototherapy is carried out in a clinical environment and utilises large fluorescent lamps. These are now being replaced with more efficient light-emitting diodes (LEDs), a trend that is set to contin ue thanks to the progress of LED technology. LEDs are also facilitating the emergence of at-home devices to improve patient convenience and decrease demand on the healt hcare system [1]. Current at-home devices consist of rigid LED arrays, which limits their conformability and produces non-uniform light distribution over the treatment area, in turn limiting their efficacy and wearability [2]. As a solution to this problem, we are engineering a flexible light therapy device that combines LEDs and a sub-mm-thick polydimethylsiloxane (PDMS) light sheet in an edge-lit configuration

Wearable LED-based device for phototherapy applications

Phototherapy with UVA/B or visible wavelengths is used to treat skin disorders such as psoriasis, eczema and vitiligo. Traditionally, phototherapy is carried out in a clinical environment and utilises large fluorescent lamps. hese are now being replaced with more efficient light-emitting diodes (LEDs), a trend that is set to continue thanks to the progress of UV LED technology. LEDs are also facilitating the emergence of at-home devices to improve patient convenience and decrease de mand on the healthcare system [1] . Current at-home devices consist of inflexible LED arrays, which limits their conformability and produces non-uniform light distribution over the treatment area, in turn limiting their efficacy and wearability [2] . As a solution to this problem, we are engineering a flexible light therapy device that combines LEDs and a sub-mm-thick polydimethylsiloxane (PDMS) light sheet in an edge-lit configuration. PDMS has previously been shown as an effective flexible light guide [3 ]; its high transparency from 290 nm upwards and its biocompatibility make it an ideal substrate for a wearable phototherapy device. We will describe the effect of coupling LEDs to our PDMS sheet and discuss design strategies for efficient and uniform light extraction to the treatment area. The PDMS acts as a waveguide and the light diffused through the top surface of the sheet is measured as irradiance (μW/cm2). By adding scattering particles for light extraction a 10-fold enhancement in irradiance has been demonstrated. Utilising a UV LED (385 nm) at an optical power of 25 mW, this approach produces a uniform emission of 140 μW/cm2 over a treatment area of 225 mm2 ( fig. 1). Simulations have shown that the addition of diffractive patterns to the sheet also produces an increased uniform emission

Evaluation of serological tests for Trichinella infections in pigs

The Dutch slaughter pig population is practically free of Trichinella spiralis. However, at slaughter every pig is tested for presence of larvae using the digestion method for export certification . A new 2006 EU directive concerning meat inspection for Trichinella spp. offers new opportunities to monitor Trichinella at herd level instead. Also serological methods are allowed when approved by the Commumty Reference Laboratory (CRL). To evaluate the usefulness of serological tests for momtoring a virtually free population for Trichinella, Bayesian methodology was used to estimate the diagnostic test parameters sensitivity and specificity, in the absence of a Gold Standard test

Hybrid GaN LED/elastomer membrane for uniform area illumination

A mechanically-flexible device for uniform area illumination is presented. The device consists of a 1mm-thick elastomeric membrane edge-lit by a GaN LED. Homogenous irradiance above 0.13 mW/cm2 at 450 nm over a 2.5 cm2 area is reported. Performance improvements, scalability and operation at other wavelengths are discussed