Double Edge Research Articles

Synthesis of sulfonated Sesamum indicum L. seed oil and its application as a fatliquor in leather processing

Fatliquor is an oil-in-water emulsion that improves the physical properties of leather such as tensile strength, flexibility, and softness by lubricating the leather fibres. Sulfonated Sesamum indicum oil was synthesized, characterized, and examined for consideration as a substitute for imported fatliquor in Nigeria. The sulfonation of the oil was confirmed by the significant observations made in the FTIR, 1H NMR, 13C NMR, and 13C NMR DEPT analysis results. A remarkable difference was observed in the physicochemical properties results of both unsulfonated and sulfonated oils. The sulfonated sesame fatliquor was applied onto goatskin and compared with a commercial sulfated fatliquor in the processing of shoe upper leather using standard methods. The average results for tensile strength, double edge tear, elongation, and softness results for the commercial and synthesized fatliquors are as follows: 14.27 N/mm2; 13.77 N/mm2, 50.61 N; 60.11 N, 38.06%; 54.28%, 25.2; 25.0. A comparable level of lubrication of the leather treated with the sulfonated Sesamum indicum oil and that treated with the commercial leather fatliquor was revealed by the Sudan IV stain test as well as scanning electron microscopy analysis results. Experimental analyses, therefore, show that the as-synthesized sulfonated Sesamum indicum oil could be considered as a substitute for imported fatliquor in the leather industry.Graphical abstract

Anisotropic Evaporator with a T-Shape Design for High-Performance Solar-Driven Zero-Liquid Discharge.

Solar-driven evaporation is regarded as a sustainable wastewater treatment strategy for clean water recovery and salt condensation. However, achieving both high evaporation rate and long-term stability remain challenging due to poor thermal management and rapid salt accumulation and blocking. Here, a T-shape solar-driven evaporator, composed of a surface-carbonized longitudinal wood membrane (C-L-wood) is demonstrated as the top "" for solar harvesting/vapor generation/salt collection and another piece of natural L-wood as the support "" for brine transporting and thermally insulating. The horizontally aligned micro-channels of C-L-wood have a low perpendicular thermal conductivity and can effectively localize the thermal energy for rapid evaporation. Meanwhile, the brine is guided to transport from the support L-wood ("") to the centerline of the top evaporator and then toward the double edge (""), during which clean water is evaporated and salt is crystallized at the edge. The T-shape evaporator demonstrates a high evaporation rate of 2.43 kg m-2 h-1 under 1 sun irradiation, and is stable for 7 days of the outdoor operation, which simultaneously realizes clean water evaporation and salt collection (including Cu2+ , CrO42- , Co2+ ), and achieves zero-liquid discharge. Therefore, the T-shape design provides an effective strategy for high performance wastewater treatment.

FDI and Economic Growth in SAARC Countries: An Empirical Analysis

Foreign Direct Investment (FDI has been considered as a powerful weapon of globalization with double edge that cuts both ways mean it impacts positively and negatively. Its impacts positively by supporting the host country’s economy in terms of capital inflows and up-to date technology but FDI also affect the host country by overexploiting its resources. Despite all these thing, this capital provides an opportunity to underdeveloped and developing countries by providing to access new markets, advance technology, cost effective production facilities and more investment opportunities. It is a two way mechanism for both the countries first, from where FDI comes and second where FDI is invested in form Greenfield and Brownfield. For the host country, it is a new way to economic development. This chapter has been investigated the effect of FDI on economic growth of host country and effect of economic growth on FDI by applying regression analysis and found that that the overall model is positive and significant at 5 percent significance level for seven countries namely Afghanistan, Bhutan, India, Maldives, Nepal, Pakistan and Sri Lanka. However, for Bangladesh the model is found to be insignificant, at second stage, ADF test is employed to data for Stationarity check. ADF calculations indicate that both the variables are stationary at level and first difference at 1 percent level of significance; however few exceptions are there, at the final stage.

Circularly Polarized Rectangular Micro Strip Patch Antenna Design, Analysis for C Band Applications

Now a days the wireless communication system development requires the low cost, low profile, minimal weight antenna development which is accomplished of continuing great presentation completed a wide frequency range. This forward-looking abilities style has supported into the MSPA (Micro Strip Patch Antenna) plan. In this administrative work presents a working recurrence of 4.85 GHz roundabout polarization rectangular miniature strip fix radio wire is planned and mimicked. The proposed rectangular miniature strip fix reception apparatus is double miniature strip-edge-took care of circularly spellbound miniature strip radio wire. The proposed receiving wire can plan and invigorate Left Hand Circular Polarization (LHCP) and Right Hand Circular Polarization (RHCP) with utilizing cross coupler is straight associated with miniature strip radio wire to get polarization of round. The proposed paper work resonant frequency or operating frequency is 4.85 GHz which is mainly used for satellite communications, full-time satellite TV networks or raw satellite feeds. This operating frequency is the IEEE 802.11a version C band frequency and this C band frequency is also used in Wi-Fi devices and Radio LAN. The proposed roundabout polarization rectangular miniature strip fix receiving wire on FR-4 (Flame Retardant and type 4) epoxy substrate material thickness of substrate is 1.6 mm. The dielectric steady of FR4 epoxy is 4.4. The double miniature strip edge took care of round polarization rectangular miniature strip fix radio wire is planned and reenacted utilizing CSTMWS (Computer Simulation Technology Micro Wave Studio) programming. The thunderous or working recurrence of proposed reception apparatus presents at 4.85 GHz for remote correspondences that gives S boundaries (return misfortune), transmission capacity and radiation example of Gain and directivity.

Situating ethno-territorial claims: dynamics of land exclusion in the Guarayos Forest Reserve, Bolivia

ABSTRACT Indigenous people have effectively employed ethno-territorial belonging as a rationale to claim land. However, as sympathetic scholar-activists, we run the risk of assuming that such rationale necessarily empowers the dispossessed. I show that this is not always the case by examining past and contemporary land disputes in the Guarayos Forest Reserve in northeast Bolivia. I thus argue for the need to situate ethno-territorial claims in specific conjunctures and in full recognition of the exclusion's double edge as observed by Hall, Hirsch and Li (2011). Doing so, in turn, calls for greater attention to class differentiation within competing ethnic groups.

Explanatory models of regional innovation performance in Europe: policy implications for regions

Research and Innovation Strategies for Smart Specialization (RIS3) was integrated as a key piece of the cohesion policy for the European Union (EU) for 2014–2020. During the recent years, more than 120 RIS3 have been developed, being a large-scale EU experience aimed to develop innovation-driven economic transformations at national and regional levels. The objective of this article is to explore the models that best explain innovative employment and the emergence of new markets in Europe’s regions. For that purpose, the latest dataset of the Regional Innovation Scoreboard 2019 was used, and regressions performed to identify the main factors behind the impact of regional innovation. The results unveil the ‘double edge role’ that some variables have on regional innovation, indicating the difficulties of managing different trade-offs and of a standalone innovation policy strategy. Policy measures are discussed to best manage these critical compromises and increase the impact of RIS3.

Covalent functionalization in graphene nanoribbon: Theoretical modeling and sensitivity analysis

The alteration of electronic properties in chemically modified graphene can be utilized for chemical and biosensing applications. Thus, it is essential to understand how the alteration of density of states and conductance spectra of functionalized zigzag and armchair graphene nanoribbon (GNR) affects its sensitivity. In this aspect, the current–voltage characteristics of GNR based sensors are modeled using the non-equilibrium Green's function method. Our findings show that the presence of chemical moiety at one edge of the zigzag GNR structure opens the bandgap that reduces the current conduction and enhances the sensitivity for detection. However, double edge functionalization restores the semi-metallic character of the zigzag ribbon that reduces the sensitivity. Both single and double edge atomic substitution in armchair ribbon makes it n-type, which shows the alteration in current conduction for detecting the presence of the chemical species. We further found that increasing the width of the ribbon decreases the device sensitivity while it increases for the double edge substituted zigzag structure. The study thus provides essential information and insights into utilizing and operating different edge structures of graphene based sensors for effective detection of chemical and biomolecular species.

Switchable X-Ray Orbital Angular Momentum from an Artificial Spin Ice.

Artificial spin ices (ASI) have been widely investigated as magnetic metamaterials with exotic properties governed by their geometries. In parallel, interest in x-ray photon orbital angular momentum (OAM) has been rapidly growing. Here we show that a square ASI with a patterned topological defect, a double edge dislocation, imparts OAM to scattered x rays. Unlike single dislocations, a double dislocation does not introduce magnetic frustration, and the ASI equilibrates to its antiferromagnetic (AFM) ground state. The topological charge of the defect differs with respect to the structural and magnetic order; thus, x-ray diffraction from the ASI produces photons with even and odd OAM quantum numbers at the structural and AFM Bragg conditions, respectively. The magnetic transitions of the ASI allow the AFM OAM beams to be switched on and off by modest variations of temperature and applied magnetic field. These results demonstrate ASIs can serve as metasurfaces for reconfigurable x-ray optics that could enable selective probes of electronic and magnetic properties.

Quad-Fabry-Perot etalon based Rayleigh Doppler lidar for 0.2-60km altitude wind, temperature and aerosol accurate measurement

Rayleigh Doppler lidar based on a quad Fabry-Perot etalon (FPE) is proposed that is capable of accurately detecting wind speed, as well as temperature and aerosol from 0.2 to 60km altitude. The structure of lidar is designed and its measurement principle is analyzed. One of the four FPEs, i.e. FPE-L is used for locking and measuring the outgoing laser frequency, and the other three, i.e. FPE-1, -2 and -3 form a three-stage FPE. The first-stage FPE (FPE-1) can effectively filter out Mie backscattering signal, thereby suppressing its effects on wind measurement and measuring the aerosol backscatter ratio as well. The transmission spectra of the second- and third-stage FPEs (FPE-2,-3) form double edge for simultaneous wind and temperature measurements by using Rayleigh backscattering signal. The parameters of the quad FPE are optimized. The FWHM and relative peak position of FPE-1,-2,-3,-L are 0.6, 1.2, 1.2, 0.6GHz and 0, -1, 1, 0.3GHz, respectively. The performance of the proposed lidar is simulated and results show that for 0.3WSr−1m-2nm−1@355nm sky brightness, by using a 350mJ pulse energy, 50Hz repetition frequency laser and a 0.8m aperture telescope, with temporal resolution of 2min@0.2∼20km, 20min@20∼60km and vertical resolution of 45m@0.2∼10km, 90m@10∼ 20km, 180m@20∼40km, 1km@40∼60km, the measurement errors of temperature, aerosol backscattering ratio and vertical wind speed are below 5.3K, 3.0×10-3, 1.1m/s in nighttime and below 14.6K, 8.1×10-3, 2.5m/s in daytime from 0.2 to 60km altitude; the measurement error of two other orthogonal LOS wind speed with fixed zenith angle of 25.8° is below 1.3m/s in nighttime and 3.5m/s in daytime within the LOS wind speed dynamic range of ±50m/s from 0.2 to 60km altitude.

Axial compressive behavior of non-symmetric cold-formed angular column with complex edge

Currently, the assembled-type light steel (ATLS) modular house is increasingly used for apartments, schools, hotels, and other similar buildings with repetitive units, in which the non-symmetric cold-formed angular section is usually served as column in the module unit. However, the compressive behavior and design method of the non-symmetric cold-formed angular column remain unknown due to the complex edge. In this paper, a series of tests were conducted on the axial compressive behavior of the non-symmetric cold-formed angular column. A total of 12 specimens with complex edge were tested under monotonic axial compression. A special support was designed at the end of the column to apply the axial compression along different loading axes of the complex section. The failure mode and axial compressive capacity of the test specimens were revealed and discussed in detail. It indicated that the loading axis significantly influenced the failure mode and axial compressive capacity of the non-symmetric cold-formed angular column. Furthermore, a 3D finite element model was developed and validated against the test results to broaden the research. Lastly, given that the current design codes for steel structures, as used in Europe, Australia/New Zealand and North, the relevant codified design was utilized to evaluate the axial compressive capacity of unequal angular column with a double edge fold stiffener, based on the obtained test data.

Double Edge Wedge Splitting Test to Characterize the Design Postcracking Parameters of Fiber-Reinforced Concrete Subjected to High Temperatures

AbstractThe determination of the postcrack tensile properties of steel fiber–reinforced concrete (SFRC) after exposure to elevated temperatures is a current methodological challenge. The objective ...

RETRACTED ARTICLE: Influence of crumb rubber particle sizes on rutting, low temperature cracking, fracture, and bond strength properties of asphalt binder

The present study aimed at evaluating the effect of Crumb Rubber (CR) particle size on rutting, low temperature cracking, fracture, and bond strength properties of asphalt binder. Three different CR particle sizes (#10–20, #30–40, and #60–80) were considered in this research work. Rutting performance was evaluated using Multiple Stress Creep Recovery (MSCR) tests. Although the addition of CR was found to improve the rutting performance, asphalt binder combination with higher CR particle size exhibited better performance compared to asphalt binder combination with lower CR particle size. Similarly, low temperature cracking properties were evaluated using Bending Beam Rheometer (BBR). It was found that the addition of CR has positive impact on the low-temperature performance of asphalt binder. Fracture property was evaluated using Double Edge Notch Tension (DENT) test and found to be improving with the increase in CR particle size. Finally, the effect of CR particle size on moisture damage resistivity potential was evaluated using the recently developed Bitumen bond strength (BBS) test. Although the addition of CR was found to have deteriorating impact on bond strength behavior, the degree of impact was found to be lower for asphalt binder containing the lowest considered CR particle size.

Making multigraphs simple by a sequence of double edge swaps

We show that any loopy multigraph with a graphical degree sequence can be transformed into a simple graph by a finite sequence of double edge swaps with each swap involving at least one loop or multiple edge. Our result answers a question of Janson motivated by random graph theory, and it adds to the rich literature on reachability of double edge swaps with applications in Markov chain Monte Carlo sampling from the uniform distribution of graphs with prescribed degrees.

Chemo-mechanical modeling of static fatigue of high density polyethylene in bleach solution

High density polyethylene (HDPE) is increasingly used in infrastructure applications with a design service lifetime of several decades. In many cases, the HDPE member is exposed to a corrosive environment, such as in pipes carrying potable water, where the dissolved bleach selectively attacks the loosely packed amorphous phase of the polymer. The failure mechanism of HDPE transitions from a ductile to a brittle mode as the corrosion level increases. This leads to subcritical crack propagation, which deteriorates the load capacity of the structure. In this study, we develop a coupled chemo-mechanical model to simulate stress corrosion cracking (SCC) in HDPE members exposed to a bleach solution. The mechanical response of the polymer is described by a constitutive model that separately considers the individual deformation and damage behaviors of the amorphous and the crystalline phases. The model accounts for the intermolecular deformation and homogeneous void growth in the crystalline and amorphous phases, along with the resistance of the entangled network and craze damage in the amorphous phase. The embrittlement due to corrosion is captured by relating the constitutive parameters of amorphous phase to the molecular weight of the polymer. The diffusion and chemical reaction of bleach are described by a reduced order kinetics model that links the extent of polymer oxidation to the reduction of the molecular weight. The material constitutive model and diffusion–reaction model are combined in a single finite element (FE) code to investigate the SCC behavior of double edge notched HDPE specimens. The simulation yields the stress-life curves and fracture kinetics under different environments. The predicted stress-life curve qualitatively matches the measured stress-life data of polymer pipes. It is shown that the stress-life curve exhibits different regimes corresponding to distinct failure mechanisms, as indicated by the stress and strain distributions in the specimen.

Evaluation of the Energetic Release During Tensile tests in Notched Specimens by means of Experimental and Numerical Techniques

Static Thermographic Method is a rapid test procedure able to predict the fatigue limit of the material evaluating the end of the thermoelastic phase during a static tensile test. In order to investigate the energetic release of the material, experimental tests have been carried out on double edge steel notched specimens. During the test, the surface temperature was monitored with an infrared camera and the true stress-strain curve of the material was retrieved. Numerical simulations have been carried out to predict the temperature evolution of the material under monotonic load. The relationship between the elasto-plastic behavior and the energetic release has been investigated comparing numerical and experimental data. The rise of irreversible plastic deformation severally affects the temperature trend introducing an additional heat amount that leads to a deviation from the linearity of the thermoelastic effect. The analysis of the temperature evolution during a static tensile test may be adopted as a novel approach to relate the local stress state with a macroscopic stress value that introduce in the material the first micro plasticization.

Mechanical properties and self-healing capacity of Ultra High Performance Fibre Reinforced Concrete with alumina nano-fibres: Tailoring Ultra High Durability Concrete for aggressive exposure scenarios

The effects of alumina nano-fibres are investigated in this paper on the mechanical performance of Ultra High Performance Fibre Reinforced Cementitious Concrete and their efficacy in enhancing the durability of the cementitious composite when exposed to extremely aggressive conditions, with main reference to the stimulated autogenous crack sealing and self-healing capacity. A tailored characterization of the flexural and tensile behaviour of the composite has been first of all performed, also with the purpose of validating an experimental and analytical approach for the identification of the tensile stress vs. strain/crack opening constitutive relationship, which makes use of a purposely conceived indirect tensile test methodology, called Double Edge Wedge Splitting test. Secondly the crack sealing and self-healing capacity have been investigated, considering the recovery of both mechanical flexural performance and durability properties (water permeability) and cross analysing the results for a thorough validation. Microstructural investigations have complemented the aforementioned experimental programme to confirm the efficacy of alumina nano-fibres in enhancing the durability performance of the investigated composites. Superior performance of the mix with alumina nano-fibres with respect to parent companion ones has been highlighted and explained through both a nano-scale reinforcing effects which helps in controlling the cracking process since its very onset as well as through their hydrophilic nature which is likely to foster cement and binder hydration reactions, which can usefully stimulate crack sealing and performance healing recovery at both the macroscopic and mesoscopic fibre-matrix interface) level.

A Nonlocal Model for Dislocations with Embedded Discontinuity Peridynamics

We develop a novel nonlocal model of dislocations based on the framework of peridynamics. By embedding interior discontinuities into the nonlocal constitutive law, the displacement jump in the Volterra dislocation model is reproduced, intrinsic singularities in classical elasticity are regularized, and the surface effect in previous peridynamics models is avoided. The extended embedded discontinuity peridynamics overcomes unphysical dissipation in treating discontinuity and is still easy to be solved with the particle-based meshless method. The properties of the proposed dislocation model are compared with classical elasticity solutions under the case of an edge dislocation, double edge dislocations, a screw dislocation, and a circular dislocation loop. Numerical results show a high consistency in the displacement field while no singularity appears in the peridynamics model, the interaction force is in agreement with the Peach-Koehler formula down to the core region and high accuracy can be reached in 3D with limited computational cost. The proposed model provides a feasible tool for multiscale modeling of dislocations. Though dislocation is modeled as a pre-defined displacement jump, it is straightforward to extend the method to model various fracture conditions.

Characterization tests for predicting the mechanical performance of SFRC floors: identification of fibre distribution and orientation effects

In the context of the evaluation of the load-bearing capacity of a steel fibre reinforced concrete (SFRC) elevated slab recently built in northern Italy, this paper presents the study addressing the effects of fibre distribution and orientation. An extensive experimental programme was carried out in a collaboration between Politecnico di Milano and Universitat Politècnica de Catalunya. The programme included mechanical tests on four shallow beams and six notched standard beams. Additionally, uniaxial tensile tests (UTTs), double edge wedge splitting tests (DEWSTs) and double punching tests (DPTs) on 192 drilled core samples extracted from the shallow beams were performed. Inductive tests, measuring the self-induction change that occurs when a SFRC sample is placed inside a coil, were performed on all samples subjected to DPTs to assess fibre distribution. This paper compares direct and indirect tensile tests for the definition of the FRC post-cracking constitutive law, highlighting advantages and disadvantages of each test type. A comparison between standard and non-standard mechanical tests is also presented. Mechanical and non-destructive tests on drilled core samples extracted in different directions and at different locations have allowed the evaluation of the effects of fibre distribution and fibre orientation which provide an estimation of the possibility of using these tests as simplified tests for production control.

Characterization tests for predicting the mechanical performance of SFRC floors: design considerations

The paper presents an experimental program carried out to check the load bearing capacity of a steel fibre reinforced concrete (SFRC) floor in northern Italy. The extensive mechanical characterization focused on the suitability of 3 non-standardized test methods for quality control and tensile constitutive curve assessment was performed, this consisting of: uniaxial tensile test (UTT), double edge wedge splitting test (DEWST) and double punching test (DPT) to characterize the post-cracking mechanical properties of the material. The joint experimental programme, carried out at the Politecnico di Milano and at the Universitat Politècnica de Catalunya, included the flexural characterization of four shallow beams (1.5 × 0.5 × 0.25 m3) and six standard notched beams (0.55 × 0.15 × 0.15 m3). All the samples were produced from the same batch and with the same SFRC mix which was applied for the floor. After that, 192 cores were drilled from the shallow beams and subjected to either UTTs, DEWSTs or DPTs. The stress level, the scatter and the constitutive curves derived from the non-standardized tests were identified and analysed. The calculated constitutive curves were used to predict the behaviour of the shallow beams.

Double and single edge sign hydrodissection: An experimental study

Introduction: Achieving correct hydrodissection in fascia plane blocks increases their success rate. With the use of ultrasound, it exceeds 80%, which is still far from 100%. This experimental study addresses the causes that lead to an approximate 20% failure probably due to the injection of the local anaesthetic between epimysium and fascia and not between fascia and fascia, as it should be. This leads to the corresponding ultrasound images: double-edge (correct sign) and single-edge (wrong sign). Method: The experiments were conducted with abdominal aponeurosis of dead pigs with the use of ultrasound and ejection with the use of epidural needles. First, the analogue sonographic images were generated and then, the surgical exposure of the tip of the needles and the distribution of the local anaesthetic was performed. Results: When the Fig. 1a,b were captured showing the right placement of the needle and the correct hydrodissection (double-edge) that was obtained, the Fig. 1c was acquired by carrying out the surgical exposure of the tip of the needle between the fascia.