Innovative all composite multi-pultrusion truss system for stressed arch deployable shelters

Trusses are one of the successful structural forms that have been utilised, at extended scale, since the nineteen century. Fibre composite materials are relatively new to civil engineering applications. The increased interest in using composites in civil applications can be attributed to advantages when compared to other construction materials that offset their associated costs. Using conventional approaches for truss systems in composite materials can undermine their efficiency. This is mainly due to concentration of stresses at connections which usually govern the truss design. The Military Modular Shelter System (M2S2) initiative is a research project that aims to develop a fibre composite re-deployable arched shelter system with rigid PVC or fabric cladding. The main frames are formed from modular fibre composite panels that are connected and stressed into position by prestressing cables. Different geometries can be obtained using this system by changing the number of panels per frame and the packer sizes between panels. This paper presents the development and testing of innovative fibre composite truss modules that were investigated as part of this project. The truss system is based on using multi-pultrusion sections for the chord and vertical members. Truss bracing is provided by a double skin laminated web. This structure offers many advantages including semi-ductile failure that occurred outside the joint area and ease of manufacturing. In spite of being developed for the M2S2 system, the concept is similarly applicable as a general purpose truss system

Two-dimensional wind-tunnel tests of a NASA supercritical airfoil with various high-lift systems. Volume 1: Data analysis

High-lift systems for a NASA, 9.3%, method for calculating the viscous flow about two-dimensional multicomponent airfoils was evaluated by comparing its predictions with test data. High-lift systems derived from supercritical airfoils were compared in terms of performance to high-lift systems derived from conventional airfoils. The high-lift systems for the supercritical airfoil were designed to achieve maximum lift and consisted of: a single-slotted flap; a double-slotted flap and a leading-edge slat; and a triple-slotted flap and a leading-edge slat. Agreement between theoretical predictions and experimental results are also discussed

Entanglement of Two Impurities through Electron Scattering

We study how two magnetic impurities embedded in a solid can be entangled by an injected electron scattering between them and by subsequent measurement of the electron's state. We start by investigating an ideal case where only the electronic spin interacts successively through the same unitary operation with the spins of the two impurities. In this case, high (but not maximal) entanglement can be generated with a significant success probability. We then consider a more realistic description which includes both the forward and back scattering amplitudes. In this scenario, we obtain the entanglement between the impurities as a function of the interaction strength of the electron-impurity coupling. We find that our scheme allows us to entangle the impurities maximally with a significant probability

Risk management for drinking water safety in low and middle income countries: cultural influences on water safety plan (WSP) implementation in urban water utilities

We investigated cultural influences on the implementation of water safety plans (WSPs) using case studies from WSP pilots in India, Uganda and Jamaica. A comprehensive thematic analysis of semi-structured interviews (n = 150 utility customers, n = 32 WSP ‘implementers’ and n = 9 WSP ‘promoters’), field observations and related documents revealed 12 cultural themes, offered as ‘enabling’, ‘limiting’, or ‘neutral’, that influence WSP implementation in urban water utilities to varying extents. Aspects such as a ‘deliver first, safety later’ mind set; supply system knowledge management and storage practices; and non-compliance are deemed influential. Emergent themes of cultural influence (ET1 to ET12) are discussed by reference to the risk management, development studies and institutional culture literatures; by reference to their positive, negative or neutral influence on WSP implementation. The results have implications for the utility endorsement of WSPs, for the impact of organisational cultures on WSP implementation; for the scale-up of pilot studies; and they support repeated calls from practitioner communities for cultural attentiveness during WSP design. Findings on organisational cultures mirror those from utilities in higher income nations implementing WSPs – leadership, advocacy among promoters and customers (not just implementers) and purposeful knowledge management are critical to WSP success

Medical-Legal Partnerships to Support Continuity of Care for Immigrants Impacted by HIV: Lessons Learned from California.

The United States (US) has experienced a surge of anti-immigrant policies and rhetoric, raising concerns about the influence on health outcomes for immigrants living in the US. We conducted qualitative interviews (n = 20) with health care and social service providers, attorneys, and legal/policy experts in California to understand how agencies were maintaining access to HIV care and prevention for immigrant clients. We conducted a thematic analysis to describe the role of medical-legal partnerships (MLPs) and document best practices. Informants reported high demand for legal services. Referrals were facilitated by case managers, medical providers, and pre-existing relationships between clinics and legal agencies. Informants identified a need for additional funding and further guidance on screening for and supporting patients with legal needs. MLPs have the capacity to create sustainable, efficient, comprehensive structural changes that minimize barriers to HIV prevention and treatment and improve health outcomes among immigrant populations

Phytoremediation and rhizosphere manipulation using different amendments

In two pot experiments using two different crop ryegrass (Lolium perenne) and two flax (Linum usitatissimum) varieties Viola and Elise, ryegrass decreased in the pool of heavy metals compared with bare soil using EDTA as extractant. NH4+ decreased the soil pH, increased EDTA-extractable Zn and increased the Zn uptake. Lime addition increased the pH and depressed Zn uptake. The pool of extractable EDTA was not changed by growing both of the flax varieties. Lime increased EDTA-extractable Cu and Pb significantly, but decreased the Zn, and pH increased in this order NH4+NH4++lime>NH4+>NO3-. Ammonium decreased the pH more than other treatments. In agar using Bromocresol purple indicator NH4+ increased the pH in the rhizosphere of different plants. With two different initial pH treatments (7 and 3.2) the NH4_ decreased the pH in the rhizosphere at high initial pH 7 and maintained the low pH at initial pH 3.2 to 4 against the buffer capacity. At different initial pH 4, 5, 6, 7 and 8 the ammonium decreased the high pH and maintained the low pH, but NO3- had no effect on the pH. Ammonium increased the toxicity of Zn due to pH decreases. There was no effect of both nitrogen sources NH4+ or NO3- on rhizosphere pH when applied as a foliar application. These indicated that the NH4+ can decrease the pH in the rhizosphere of plants and could play an important role in manipulation of the rhizosphere bioavailability of heavy metals. Toxicity of the three metals is Cu>Pb>Zn in this order and the crops tolerance is following this order pea>flax>barley. An agar-Hoagland nutrient solution contaminated with two soils, sewage treated soil (SBS) and galena soil (G), was used with flax as a test crop. The ammonium treatment lowered the pH in both soils, but with galena treated greater than SBS soil, this is attributed to the buffering capacity of the SBS soil. Averaged over all the concentrations the NF4+ treatments resulted in higher Zn shoot content that NO3- treatment, while in Cu shoot content nitrate was more than ammonium. The transfer factor of lead with ammonium treatment was greater than nitrate treatments at the 0.1 and 0.25% galena and the transfer factor of the Zn and Pb more than Cu in all treatments. At high initial pH 8 and high concentration of Zn and Cu barley grew well and this is attributed to immobilisation of Zn and Cu compared with low pH 5 and 6.5 where the barley plant did not survive. Ammonium lowered the high pH 8 and caused lower biomass production of barley than nitrate

International Trade and Investment in Algeria: An Overview

Article published in the Michigan State International Law Review