Automated Low-Pressure Carbonate Eluent Ion Chromatography System with Postsuppressor Carbon Dioxide Removal for the Analysis of Atmospheric Gases and Particles

We present a low-pressure, automated, semi-continuous Gas-Particle Ion Chromatograph to measure soluble ionogenic gases and soluble ionic constituents of PM_2.5. The system utilizes a short separation column, an isocratic carbonate eluent and post suppressor CO₂ removal. Measured constituents include ammonium, nitrate, and sulfate in the particle fraction, and nitric acid, sulfur dioxide, and ammonia among soluble gases. Two independent sampling channels are used. In one channel, a wet denuder collects soluble gases. In the second channel, following removal of large particles by a cyclone and soluble gases by a wet denuder, a hydrophobic filter-based particle collector collects and extracts the soluble components of PM_2.5. The aqueous particle extract is aspirated by a peristaltic pump onto serial cation and anion preconcentrator columns. Gas samples are similarly loaded onto another set of serial cation and anion preconcentrator columns. The cation preconcentrator is eluted with NaOH and the evolved NH₃ is passed across a membrane device whence it diffuses substantially into a deionized water receptor stream; the conductivity of the latter provides a measure of NH₃ (NH₄ ⁺). The anion preconcentrator column(s) are subjected to automated periodic analysis by ion chromatography. This system provides data every 30 min for both particles (NO₃ ^?, SO₄ ^{2 ?} and NH₄ ⁺) and gases (HNO₃, SO₂ and NH₃). Gas and particle extract samples are each collected for 15 min. The analyses of the gas and particle samples are staggered 15 min apart. The limit of detection (S/N = 3) for NO₃ ^?, SO₄ ^2? and NH₄ ⁺ are 2.6, 5.3, and 2.1 ng/m³, respectively.     

Strain-sensitive Raman spectroscopy and electrical resistance of carbon nanotube-coated glass fibre sensors

This paper presents the development of glass fibres coated with nanocomposites consisting of carbon nanotubes (CNTs) and epoxy. Single glass fibres with different CNT content coating are embedded in a polymer matrix as a strain sensor for composite structures. Raman spectroscopy and electrical response of glass fibres under mechanical load are coupled for in situ sensing of deformation in composites. The results show that the fibres with nanocomposite coating exhibit efficient stress transfer across the fibre/matrix interface, and these with a higher CNT content are more prone to fibre fragmentation at the same matrix strain. A relationship between the fibre stress and the change in electrical resistance against the fibre strain is established. The major finding of this study has a practical implication in that the fibres with nanocomposite coating can serve as a sensor to monitor the deformation and damage process in composites.     

A hexapod-based machine tool with hybrid structure: Kinematic analysis and trajectory planning

This paper shows kinematic analysis and trajectory planning for a novel machine tool structure consisting of a six degree-of-freedom hexapod machine and a two-degree-of-freedom rotary table. Accordingly, to operate the proposed machine tool, eight coordinates should be defined. Since a conventional part programming can define at the most five axes, the three remaining coordinates should be defined by using appropriate trajectory planning. An analytical model is developed that defines the relationships among the parameters in the proposed structure. A rule-based model is also developed to select the redundant coordinates without going through any complex and time-consuming calculations.     

Meta-linguistic axioms as a foundation for computing with words

Meta-linguistic axioms are proposed in analogy to the axioms of classical theory as a foundation for Computing With Words. Consequences of these meta-linguistic expressions are explored in the light of Interval-valued Type-2 Fuzzy Sets. The mapping of meta-linguistic axioms to Fuzzy Disjunctive and Conjunctive Canonical forms generate two set theoretic axioms for each meta-linguistic axiom that is composed of two elements such as commutativity and four set theoretic axioms for each meta-linguistic axiom that is composed of three elements such as associativity as opposed to one axiom that is generated in the classical theory. The set theoretic axioms double or quadruple because the basic equivalences of the classical theory break down in fuzzy theory. In this setting, we become aware that first, these new axioms hold as a matter of degree, and secondly there is an upper and lower limit with which they hold as a matter of degree.     

Surface-initiated ring opening polymerization of N-carboxy anhydride of benzyl-l-glutamate monomers on soft flexible substrates

The potential of pulsed plasma deposited polyallylamine (PAA) adlayer has been successfully demonstrated for fabrication of polypeptide brushes functionalized soft flexible polymeric surfaces. Polymeric substrates functionalized with the plasma deposition PAA adlayer resulted in polymeric surfaces functionalized with amino groups, which are the suitable initiating moieties for ring-opening polymerization (ROP) of N-carboxy anhydride of benzyl-l-glutamate (NCA-BLG) monomer. Poly(γ-benzyl-l-glutamate) (PBLG) brushes were grown on PAA functionalized polypropylene (PP), and polytetrafluoroethylene (PTFE) polymeric substrates. These substrates were intentionally chosen for their inert chemical nature towards most wet chemical surface modification reactions. Surface grafted thin films of poly(γ-benzyl-l-glutamate) PBLG on both the PP and PTFE polymeric substrates yielded high density PBLG brushes. PBLG chain orientation, secondary structure and grafting density were characterized by infra-red spectroscopy. The synthesis of PBLG brushes on a flexible polymeric substrate is unprecedented and technologically important, since PBLG possess good electro-optical activity. Analysis of brush layers by Attenuated Total Reflectance Infra-Red (ATR-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS) as well as atomic force microscopy (AFM) fully corroborated the success of the plasma activated soft surface grafting approach.     

CNN features with bi-directional LSTM for real-time anomaly detection in surveillance networks

Multimedia Tools and Applications - In current technological era, surveillance systems generate an enormous volume of video data on a daily basis, making its analysis a difficult task for computer...     

AMA: a new approach for solving constrained real-valued optimization problems

Memetic algorithms (MA) have recently been applied successfully to solve decision and optimization problems. However, selecting a suitable local search technique remains a critical issue of MA, as this significantly affects the performance of the algorithms. This paper presents a new agent based memetic algorithm (AMA) for solving constrained real-valued optimization problems, where the agents have the ability to independently select a suitable local search technique (LST) from our designed set. Each agent represents a candidate solution of the optimization problem and tries to improve its solution through co-operation with other agents. Evolutionary operators consist of only crossover and one of the self-adaptively selected LSTs. The performance of the proposed algorithm is tested on five new benchmark problems along with 13 existing well-known problems, and the experimental results show convincing performance.     

Comparison and analysis of eight scheduling heuristics for the optimization of energy consumption and makespan in large-scale distributed systems

In this paper, we study the problem of scheduling tasks on a distributed system, with the aim to simultaneously minimize energy consumption and makespan subject to the deadline constraints and the tasks’ memory requirements. A total of eight heuristics are introduced to solve the task scheduling problem. The set of heuristics include six greedy algorithms and two naturally inspired genetic algorithms. The heuristics are extensively simulated and compared using an simulation test-bed that utilizes a wide range of task heterogeneity and a variety of problem sizes. When evaluating the heuristics, we analyze the energy consumption, makespan, and execution time of each heuristic. The main benefit of this study is to allow readers to select an appropriate heuristic for a given scenario.     

Fabrication of CdO–graphene embedded mesoporous TiO2 composite for the visible-light response and its organic dye remediation

ABSTRACT

In this study, mesoporous CdO–graphene and mesoporous TiO₂ were successfully synthesized using a facile method. The results indicated that photocatalytic activity can be enhanced with the combination of mesoporous CdO–graphene and mesoporous TiO₂. The photocatalytic performance of the mesoporous CdO–graphene–TiO₂ photocatalyst presents significantly improved photocatalytic activity of safranine O, reactive black B, and GA due to the improvement of the surface area and the small average pore size distribution of the as-prepared mesoporous CdO–graphene–TiO₂. The photodegradation rate was optimized by safranine O at a pH solution of 11 and by GA at the dosage amount of 0.07 g photocatalyst.