Environment-friendly Structure Research Articles

Reinforced soil wall with gabion facing – a case study of water front structure

The increasing demand for utilities infrastructure and development projects has become a key factor in providing feasible and economical solutions in recent decades. There is a need of the day, to utilize locally available resources while designing such projects. The Reinforced Soil Wall (RSW) with Gabion Facing provides a flexible modular environment-friendly structure that is proven to be suitable for waterfront structures, and feasible with available boulders in the vicinity. This paper showcases a case study of RS wall with Gabion Facing for the diversion of Ulwe River - a part of Navi Mumbai International Airport (NMIA) Project. A roughly 3.2km long river diversion has been widened, moreover, an approximately 90 mt high hill was flattened to pave the way for NMIA, adjacent to Panvel Creek. The proposed channel dimensions of the diversion river were increased after studying the data for the last 100 years of rainfall, so that the heavy rainwater can be discharged without flooding. The composite solution of the RS wall with metal gabions as a facia has facilitated the diversion of the Ulwe River to divert water flow up to Panvel Creek. The geogrids were installed with the stone–filled metal gabions, along with connector rods to form a positive connection. To prevent the scouring of the non-rocky river bed at RS wall base, the Gabion mattresses were provided.

Boosting ensembles for estimation of discharge coefficient and through flow discharge in broad-crested gabion weirs

Gabion weirs are environment-friendly structures widely used for irrigation and drainage network purposes. These structures' hydraulic performance is fundamentally different from solid weirs' due to their porosity and the existence of a through-flow discharge. This paper investigates the reliability and suitability of a number of Machine learning models for estimation of hydraulic performance of gabion weirs. Generally, three different Boosting ensemble models, including Gradient Boosting, XGBoost, and CatBoost, are compared to the well-known Random Forest and a Stacked Regression model, with respect to their accuracy in prediction of the discharge coefficient and through-flow discharge ratio of gabion weirs in free flow conditions. The Bayesian optimization approach is used to fine-tune model hyper-parameters automatically. Recursive feature elimination analysis is also performed to find optimum combination of features for each model. Results indicate that the CatBoost model has outperformed other models in terms of estimating the through flow discharge ratio (Qin/Qt) with R2 = 0.982, while both XGBoost and CatBoost models have shown close performance in terms of estimating the discharge coefficient (Cd) with R2 of CatBoost equal to 0.994 and R2 of XGBoost equal to 0.992. Weakest results were also produced by Decision tree regressor with R2 = 0.821 and 0.865 for estimation of Cd and Qin/Qt values.

Product pricing and green decision-making considering consumers' multiple preferences under chain-to-chain competition

PurposeIt is necessary to implement green supply chains. But green development needs to be gradual and coexist with ordinary products in the market. This paper aims to study the green and ordinary product pricing and green decision-making under chain-to-chain competition.Design/methodology/approachThis paper considers consumers' multiple preferences and takes two competitive supply chains with asymmetric channels as the research object. Through the construction of the game models involving different competitive situations, this paper studies the pricing, green decision-making and the supply chains' profits, and discusses the impact of consumer green preference, channel preference, green investment and competition on the decision-making and performance. Finally, this paper further studies the impact of the decision structure on the environmental and economic benefits of supply chains.FindingsThe results show that consumer green preference has an incentive effect on the green supply chain and also provides an opportunity for the regular supply chain to increase revenue. Specifically, consumers' preference for green online channels improves the product greenness, but its impact on the green retailer and regular supply chain depends on the green investment cost. Moreover, competition not only fosters product sustainability, but also improves supply chain performance. This paper also points out that the decentralization of the regular supply chain is conducive to the environmental attributes of the green product, while the environment-friendly structure of the green supply chain is different under different conditions. In addition, the profit of a supply chain under centralized decision is not always higher than that under decentralized decision.Originality/valueThe novelty of this paper is that it investigates the pricing of two heterogeneous alternative products and green decision-making for the green product under the competition between two supply chains with asymmetric channels, in which the green supply chain adopts dual channels and the regular supply chain adopts a single retail channel.

The consistency measure of hunan’s electric power industry prosperity index

In view of the problem that the traditional electric power prosperity index lacks the support of the mixed frequency and multi-dimension data, a new consistency measure method is constructed, which uses time difference correlation analysis and principal component and consider the linkage of electric power and economy at the same time. Take the Hunan province for example, we set the pool of kinds of sectional electricity power consumption and other relatives data, use the method of principal component analysis to capture main character of electricity’s change. The results show that the proposed consistency measurement model can describe the fluctuation characteristics of Hunan’s Power Prosperity Index well. The model can be used for monitor the changes in the power industry status and promoting the policy-making about the adjustment of the energy-saving and environment-friendly structure.

Design of acrylic acid/nanoclay grafted polysaccharide hydrogels as superabsorbent for controlled release of chlorpyrifos

In the present study, acrylic-bonded starch nanocomposite hydrogels were synthesized in the presence of montmorillonite nanoclay. N,N′-methylenebisacrylamide was used as a crosslinker and ammonium persulfate was used as an initiator. The hydrogel performance was investigated as superabsorbent for water absorption under different synthesis conditions such as acrylic acid to starch ratio, crosslinker, initiator, and nanoclay amounts, and pH. Synthetic nanocomposites were characterized and approved using FTIR, XRD, FESEM-EDX, and DTA techniques. Under optimal conditions (acrylic acid to the starch ratio: 7 to 1, potassium persulfate: 0.04 g, methylenebisacrylamide: 0.002 g, nanoclay: 1 g, and pH = 7), the swelling ratio of synthetic hydrogel reached up to 400 times of the gel strength of the matrix. This superabsorbent was then investigated as a carrier for the controlled release of chlorpyrifos after in situ loading in different concentrations. The hydrogel with 1.0 M chlorpyrifos content showed a release percentage of 85% after 14 days. This proposed nanocomposite with excellent water absorbency, controlled release of chlorpyrifos, the economical and environment-friendly structure can be useful in agricultural applications.

Structural and Building Engineering – an Introduction

Construction is a reflection of the current state of society. The construction is created as a result of a creative process including preparation, all stages of design and implementation. Current trends of modern building structures with a large span are characterized by the introduction of new types of load-bearing structural systems with excellent ecological, economic and aesthetic properties. The paper aim is to introduce the interaction and context in design and create a reliable economic and environmental friendly structure that will serve the required purposes.

Life-cycle sustainability design of RC frames under the seismic loads

Seismic design codes have minimal criteria and serviceability limits for the strength of structures against a selected earthquake hazard level, neglecting the structural performance during the lifetime. Life-cycle cost analysis (LCCA) includes all the expected damage costs in the lifetime of buildings in terms of all-natural hazards such as the earthquake. In addition, to create an environment-friendly structure, environmental impacts of the entire life-cycle period should be identified and evaluated. Therefore, a novel approach for the sustainable design of reinforced concrete (RC) frames is defined in terms of the life-cycle cost components and societal effects associated with environmental impacts. Expected damage costs included the structural, non-structural, and social damage costs. Environmental impacts have been estimated based on the material consumption during the lifetime due to initial production and operation periods due to repair, and then these impacts were scored. Given the nonlinear behavior of the structure under earthquake excitation, simple response functions have been generated to reduce the analysis time. In this way, the number of nonlinear dynamic analyses which is time-consuming was reduced considerably. The proposed method was used for a RC frame to achieve optimally designed structures by introducing three objective functions. The results indicated that using the proposed methodology, sustainable RC frames were obtained with low computational costs.

APPLICATION POSSIBILITIES OF BACTERIA AND MICROALGEA IN TEXTILE DYEING AND PRINTING

Textile dyeing and printing sector which has an important place in the country’s economy, has been discussed for long years because of its environmental impact depending upon the excess amounts of water consumption and harmfull dyes released into waste water at the end of dyeing and treatment processes. The necessary deying pigments have been obtained from some kinds of vegetables and animals or from the synthesis of lickens and fungus in ancient times. As a result of the invention of synthetic dyes in 19th century, the interest on natural dyeing materials has lessened. Though the ecological damage they caused has been proven radically, the use of synthetic dyes still continues. Today biological materials and bacterial pigments which have been studied as an alternative to syhthetic dyes have been preferred because of their bio-degradable and environmental-friendly structure. However, since studies subjecting bacteria and algea are at the stage of R&D, they have not been placed in textile industrial applications but only used by avangard artists as a form of art. Pigmentation of microalgae which is an innovative study domain, attracts attention because of artistic, environmental and innovative sides. Thus, this paper aims the sample the studies of designers who employ bacterial pigments and microalgae in their textile dyeing and printing researches. Keywords: bacteria, microalgae, textile dye-print, textile design

DFT calculations based insight into bonding character and strength of Fe2Al5 and Fe4Al13 intermetallics at Al-Fe joints

The joining of aluminum and steel has been considered as the efficient combination to develop lightweight and environmental friendly structures. However, due to the significant differences in mechanical and physical properties of aluminum and steel, the joining of these two metals is challenging, where typically several intermetallic phases are formed at the interface. Origin of intermetallic phases at the Al-Fe interface is inevitable due to the low intermixing of Al and Fe. Thus in order to achieve reliable joining, it is necessary to have basic understanding about these intermetallic phases. This paper aims to describe mechanical and bonding properties of the two most commonly observed phases, Fe4Al13 and Fe2Al5. The formation energy, elastic properties and nature of bonding of Fe4Al13 and Fe2Al5 have been calculated. The results show that Fe2Al5 is thermodynamically more stable than Fe4Al13, and it seems to be less brittle than Fe4Al13. Electron localization plots of these compounds show a combination of covalent and metallic bonding, where Fe4Al13 shows a stronger tendency of covalent character than Fe2Al5

Seismic Behavior of Rammed Earth Walls with Precast Concrete Tie Columns

Rammed earth (RE) constructions are widespread in underdeveloped rural areas in developing countries. However, these RE constructions are often susceptible to earthquake damage due to their poor seismic performance. Precast concrete tie columns and ring beam (tie bars) were proposed to improve the seismic behavior of RE constructions. Four RE walls, including a traditional RE wall and three RE walls with precast concrete tie columns and ring beam (tie bars), were tested under reversed cyclic loading, and the seismic behavior of these tested specimens was evaluated in terms of failure pattern, energy dissipation, displacement ductility, and stiffness degradation. The results showed that a significant increase of the load‐bearing and deformation capacity could be achieved with the application of precast concrete tie columns in combination with RE. The load‐bearing capacity and deformation capacity of traditional RE wall were increased by an average of 113% and 417%, respectively. These test results could provide reference to the design and construction of the environmental‐friendly structures in rural areas.

Assessing heuristic models through k-fold testing approach for estimating scour characteristics in environmental friendly structures

Scouring downstream of grade control structure is a common problem. W-weir structures are recommended for controlling, reducing soil erosion, and development aquatic organisms habitat. W-weir structures can provide energy dissipation, increased aquatic habitat, grade-control, and bank and bed stabilization through the diversion of conveyance with the river-channel center. The current study aimed at analyzing the scour geometry downstream of W-weirs in the sinuous channels using heuristic gene expression programming (GEP) and support vector machine (SVM) models. A comparison was also made between the GEP and SVM with traditional multi variable linear regression (MLR) technique. The cross-validation technique (i.e. k-fold testing) was used to assess the developed models. Observations revealed that the scour typology affects the maximum scour depth value. The obtained results showed that both the GEP and SVM models give promising results in simulating the scour depth and scour length magnitudes. Assessing the models confirmed that using the k-fold testing cross validation is very necessary as all the available patterns can participate in training and testing stages, which reduces the risk of over fitting.

Preparation of new diatomite-chitosan composite materials and their adsorption properties and mechanism of Hg(II).

A new composite absorbent with multifunctional and environmental-friendly structures was prepared using chitosan, diatomite and polyvinyl alcohol as the raw materials, and glutaraldehyde as a cross-linking agent. The structure and morphology of the composite absorbent, and its adsorption properties of Hg(II) in water were characterized with Fourier transform infrared (FT-IR) spectra, scanning electron microscope (SEM), X-ray diffraction (XRD), Brunauer Emmett Teller (BET) measurements and ultraviolet–visible (UV–Vis) spectra. The effect of the pH value and contact time on the removal rate and absorbance of Hg(II) was discussed. The adsorption kinetic model and static adsorption isotherm and regeneration of the obtained composite absorbent were investigated. The results indicated that the removal of Hg(II) on the composite absorbent followed a rapid adsorption for 50 min, and was close to the adsorption saturation after 1 h, which is in accord with the Langmuir adsorption isotherm model and the pseudo-second-order kinetic model. When the pH value, contact time and the mass of the composite absorbent was 3, 1 h and 100 mg, respectively, the removal rate of Hg(II) on the composite absorbent reached 77%, and the maximum adsorption capacity of Hg(II) reached 195.7 mg g−1.

순환유동층 애시를 자극제로 사용한 고로슬래그 미분말 기반 비소성 시멘트의 수화 및 단열 특성

As people have more interest in environment-friendly structures recently, many researchers are actively researching non-sintered cement in Korea and other countries. Non-sintered cement shows various characteristics of its reaction products and hardeners, depending on the kind of alkali activators. Thus, this study manufactures ground granulated blast furnace slag based non-sintered cement binder by using circulating fluidized bed combustion ash, which is a kind of industrial byproduct, as a stimulant, and investigated its hardening characteristics and hydration, depending on the rate of circulating fluidized bed combustion ash. Besides, this study investigated its insulation property according to the weight lightening of non-sintered cement. As a result, ettringite and C-S-H were mainly formed in the hydration, and it was possible to manufacture a non-sintered cement hardener over 50 MPa. Lastly, it was possible to manufacture a non-sintered cement hardener in a thermal conductivity level of 0.127 W/m·K when the compressive strength was 10 MPa for weight lightening.

Coastal protection measures, case study (Mediterranean zone, Egypt)

The rapid erosion in most coastlines is considered a major problem not only in Egypt, but also around the world. The main causes are due to anthropogenic activities and/or coastal hydrodynamics. The coastal zone suffers from sedimentation, accretion, and pollution problems as well as the side effect of climate change. The climate change will increase sea level rise, salt water intrusions, and storm surge. Major efforts has been exerted to manage coastal erosion problems and to restore coastal capacity in order to protect housing, infrastructure and the cultivated land. These problems were encountered with various types of hard structures, but most of these methods response were limited due to lack in evaluation of the entire ecological situation. This encouraged the coastal engineers to think about new types of environmental friendly structures work better with ecological situation. In this study, the protection measures worldwide is reviewed and divided mainly into four groups, hard, soft, combined, innovative measures. The usage and side effect of each type is mentioned briefly. It is clear that there is a predominant approach towards the soft engineering, the eco-engineering techniques, or combination between them in order to enhance the ecological situation. Recently, there are several efforts to apply these new technologies to protect the coastal zone as well as the environment by taking into consideration the effect of climate change. These new approaches in coastal protection are multi used, environmentally friendly, easy to modify and maintain, and efficient from an economic perspective. Previous efforts in solving coastal problems in Egypt are analyzed and discussed taking into consideration the experience of similar cases worldwide. It is clear that the environmental friendly coastal structure is more suitable to solve most of our coastal problems with saving our ecosystem and reduce the protection cost.

Investigation on Mechanical Properties of Natural Fiber Composite Using RTM Manufacturing Method

In this study, an investigation on mechanical properties of flax/vinyl ester natural fiber composite was performed. Vacuum Assisted Resin Transfer Molding (VARTM) manufacturing method was adopted for manufacturing the flax fiber composite specimen. The mechanical properties of the manufactured flax composites were compared with flax composite data cited from some references. Based on this, the experimental data showed that the flax/vinyl ester composite has some advantages when it is applied to environment-friendly structure.

AMANWANA RESORT: INSPIRING NATURE CONSERVATION AND COMMUNITY EMPOWERMENT

The triple bottom line of economy, ecology and socio-cultural benefits is the means to sustainable tourism, suggesting that the success of a tourism company is not only defined by the monetary gains but also by the impacts that the company's activities have on environment and society as a whole. Recognizing the sustainability of its operation rests on its ability to work harmoniously in its environmental and social settings, the Amanwana Resort management has particularly focus on direct and indirect contributions to natural environment conservation and community empowerment. As an ecotourism-based resort located in Moyo Island where the greater terrestrial part is a Hunting Park and the surrounding body of water is a Marine Recreational Park which formed the major tourism attractions, Amanwana's planning and development of the attractions were concentrated on the need to co-exist with the fragile naturalenvironment. Amanwana's pro-environment commitment was demonstrated byminimum alteration of local surroundings, environmental-friendly structures, the Moyo Conservation Fund to preserve forest and coral reefs habitats, nature trail walks, and employment of local villagers to protect nature from illegal logging, illegal fishing and destruction. The company's pro-social commitment was indicated by the facilities and infrastructural development in the nearby village and local employment. As much as 85-95% of the total 120 Amanwana staffs were Indonesian, and of these 35% were locals. Residents also enjoyed the additional economic benefits of tourists staying at Amanwana Resort. Almost 20 years after its establishment, no natural disasters, ecological disturbance and social conflicts related to Amanwana Resort have been recorded.