Functionalization of Carbon Nanotube Yarn by Acid Treatment

Carbon nanotube (CNT) yarn was functionalized using sulfuric and nitric acid solutions in 3:1 volumetric ratio. Successful functionalization of CNT yarn with carboxyl and hydroxyl groups (e.g., COOH, COO–, OH, etc.) was confirmed by attenuated total reflectance spectroscopy. X-ray diffraction revealed no significant change to the atomic in-plane alignment in the CNTs; however, the coherent length along the diameter was significantly reduced during functionalization. A morphology change of wavy extensions protruding from the surface was observed after the functionalization treatment. The force required to fracture the yarn remained the same after the functionalization process; however, the linear density was increased (310%). The increase in linear density after functionalization reduced the tenacity. However, the resistivity density product of the CNT yarn was reduced significantly (234%) after functionalization

Male Partners Involvement in Spousal Contraceptive Use: A Perspective of a Contemporary African Setting

Background: Contraceptive use by women is one of the tools used for promoting family health and slowing population growth. Evidence has suggested that contraceptive use in Nigeria is below acceptable levels in spite of the fact that family planning services are readily available, accessible and affordable. The involvement and participation of males in spousal contraceptive use is seen as the driver to achieving better reproductive outcomes. Hence, this study aimed to determine the level of male involvement in spousal contraceptive use so as to provide evidence based and people oriented information on the available male partner support system for contraceptive use and factors influence it.Methodology: This was a cross sectional study conducted among 80 male partners between April and May, 2017 using quantitative method of data collection and SPSS version 20 was used for data analysis.nbsp Crude and adjusted odds ratios as well asnbsp 95% confidence interval were used in this study with a p-value of le 0.05 considered statistically significant.Results: The mean age of the respondents in the study was 40.0 plusmn 10 years with only 13 (16.3%) of the respondents adjudged as being involved in their spousal contraceptive use. Currently use of male contraceptive method was found to significantly influence involvement in spousal contraceptive use (AOR = 7.1 95% CI = 2.1092 ndash 10.5818 P = 0.015). Conclusion: This study has demonstrated a low level of male involvement in spousal contraceptive use hence, relevant male educational intervention on contraception is required

Compressive and Bending Performance of Selectively Laser Melted AlSi10Mg Structures

Selective laser melting (SLM) is a widely used additive manufacturing technique that effectively manufactures complex geometries such as cellular structures. However, challenges such as anisotropy and mechanical property variation are commonly found due to process parameters. In a bid to utilize this method for the commercial production of cellular structures, it is important to understand the behavior of a material under different loading conditions. In this work, the behavior of additively manufactured AlSi10Mg under compression, bending, and tension loads was investigated. Vertical and horizontal build directions are compared for each type of loading. Specimens were manufactured using the reduced build volume (RBV) chamber of the Renishaw AM 250 SLM machine

Spectrally-resolved Imaging of the Transverse Modes in Multimode VCSELs

Vertical-cavity surface-emitting lasers (VCSELs) enable a range of applications such as data transmission, trace sensing, atomic clocks, and optical mice. For many of these applications, the output power and beam quality are both critical (i.e. high output power with good beam quality is desired). Multi-mode VCSELs offer much higher power than single-mode devices, but this comes at the expense of lower beam quality. Directly observing the resolved mode structure of multi-mode VCSELs would enable engineers to better understand the underlying physics and help them to develop multi-mode devices with improved beam quality. In this work, a low-cost, high-resolution (\u3c3 \u3epm) Echelle grating spectrometer system is used to map the two-dimensional VCSEL near-field emission profile. The system spectrally disperses the VCSEL beam and images it with high magnification onto a CMOS camera. The narrow spectral content of each LP mode allows direct observation of the modal content of the VCSEL

The Fukushima Daiichi Accident

The Fukushima Daiichi Accident consists of a Report by the IAEA Director General and five technical volumes. It is the result of an extensive international collaborative effort involving five working groups with about 180 experts from 42 Member States with and without nuclear power programmes and several international bodies. It provides a description of the accident and its causes, evolution and consequences, based on the evaluation of data and information from a large number of sources available at the time of writing. The set contains six printed parts and five supplementary CD-ROMs. Contents: Report by the Director General; Technical Volume 1/5, Description and Context of the Accident; Technical Volume 2/5, Safety Assessment; Technical Volume 3/5, Emergency Preparedness and Response; Technical Volume 4/5, Radiological Consequences; Technical Volume 5/5, Post-accident Recovery; Annexes. The JRC contributed to volumes 1,2 and 3, which are attached.JRC.F.5-Nuclear Reactor Safety Assessmen

Mechanical Performance of Sandwich Composites with Additively Manufactured Triply Periodic Minimal Surface Cellular Structured Core

Sandwich composite structures are comprised of a low-density core (commonly honeycomb) and facesheets. They are typically used in applications that require lightweight for efficient design, such as in the marine and aerospace industries. This work investigates the feasibility of adopting triply periodic minimal surface (TPMS) cellular structures as the core for sandwich composites. Sandwich structures were manufactured using a carbon fiber-reinforced polymer (CFRP) facesheet and three different 304 L stainless steel core structures (honeycomb, gyroid TPMS, and diamond TPMS). Three mechanical tests, namely edgewise compression, three-point bend, and impact test, were carried out to evaluate the performance of each sandwich configuration. The experimental results of the non-traditional sandwich configurations were compared against those of a honeycomb core sandwich composite. The edgewise compression test showed that the ultimate edgewise compressive strength increased by 7% when the honeycomb core was replaced by the gyroid core and reduced by 2% when the diamond core replaced the honeycomb core. The three-point bend test showed that the traditional honeycomb core sandwich configuration had a higher shear yield stress when compared to the non-traditional sandwich structures. The shear yield stress was reduced by 54% when non-traditional sandwich cores were used. The shear ultimate stress was reduced by 41% and 37% when the honeycomb core was replaced by the gyroid and diamond structure, respectively. Impact test results, on the other hand, showed that the peak force recorded during the impact event was reduced, while the absorbed energy was increased when non-traditional cores were used. Peak force was reduced by 28% and 39%, while the absorbed energy was increased by 9% and 16% when the honeycomb core was replaced by the gyroid and diamond cores, respectively

The Influence of Build Parameters on the Compressive Properties of Selective Laser Melted 304L Stainless Steel

Process parameters used during Selective Laser Melting (SLM) process have significant effects on the mechanical properties of the manufactured parts. In this study, the influence of two build parameters (build orientation and hatch angle) on the compressive properties of 304L stainless steel was evaluated. SLM 304L samples were manufactured using three hatch angles, 0°, 67°,105° and two orientations, z-direction and x-direction, and tested using a compression frame according to ASTM E9-09. Bulk density was measured according to ASTM C373-17 before compression. Properties evaluated were the bulk density, yield strength, strength at 15% plastic-strain and strength at 30% plastic-strain. Results showed that bulk density varied minutely with respect to variation in hatch angle and build orientation, but compressive yield strength and plastic flow stress were strongly influenced by these two process parameters. Highest compressive yield strength was measured when samples were built in the x-direction using hatch angle 67°.Mechanical Engineerin

An Official ATS/AACN/ACCP/ESICM/SCCM Policy Statement : Responding to Requests for Potentially Inappropriate Treatments in Intensive Care Units

Background: There is controversy about how to manage requests by patients or surrogates for treatments that clinicians believe should not be administered. Purpose: This multisociety statementprovides recommendations to prevent and manage intractable disagreements about the use of such treatments in intensive care units. Methods: The recommendations were developed using an iterative consensus process, including expert committee development and peer review by designated committees of each of the participating professional societies (American Thoracic Society, American Association for Critical Care Nurses, American College of chest Physicians, European Society for Intensive Care Medicine, and Society of Critical Care). Main Results: The committee recommends: (1) Institutions should implement strategies to prevent intractable treatment conflicts, including proactive communication and early involvement of expert consultants. (2) The term "potentially inappropriate" should be used, rather than futile, to describe treatments that have at least some chance of accomplishing the effect sought by the patient, but clinicians believe that competing ethical considerations justify not providing them. Clinicians should explain and advocate for the treatment plan they believe is appropriate. Conflicts regarding potentially inappropriate treatments that remain intractable despite intensive communication and negotiation should be managed by a fair process of conflict resolution; this process should include hospital review, attempts to find a willing provider at another institution, and opportunity for external review of decisions. When time pressures make it infeasible to complete all steps of the conffict-resolution process and clinicians have a high degree of certainty that the requested treatment is outside accepted practice, they should seek procedural oversight to the extent allowed by the clinical situation and need not provide the requested treatment. (3) Use of the term "futile" should be restricted to the rare situations in which surrogates request interventions that simply cannot accomplish their intended physiologic goal. Clinicians should not provide futile interventions. (4) The medical profession should lead public engagement efforts and advocate for policies and legislation about when life-prolonging technologies should not be used. Conclusions: The multisociety statement on responding to requests for potentially inappropriate treatments in intensive care units provides guidance for clinicians to prevent and manage disputes in patients with advanced critical illness