The Influence of Incorporating Plastic within Concrete and the Potential Use of Microwave Curing; A Review

In recent decades, researchers have used plastic to replace natural aggregates (NAs), or as filler and fibre within the concrete. This particular paper puts forward a review that gives comprehensive consideration to the properties and drawbacks, of concrete that contains plastic. As such, it may be hypothesised that poor bond capacity and higher air content due to inclusion of plastic aggregate (PA) within concrete are the predominant factors that reduce the properties in terms of mechanics and durability. In that regard, this study has put forward a new method of curing using microwave irradiation for improvement with respect to those factors. So, that there can be further improvement with regard to overall durability with respect to advanced chemical and hydrophobic resistivity and enhanced performance for conventional concrete with respect to bonding and ductility

Sustainability Reporting : Companies’ selection of material aspects

Sammanfattning I och med ökat antal globala kriser och ökad intressentmedvetenhet kring företagens samhällspåverkan har hållbar utveckling blivit en central och viktig fråga både för företag och enskilda individer. Till följd av detta har företag ett ansvar att arbeta hållbart och ta miljö- och socialhänsyn, genom att hållbarhetsredovisa försöker företag tillgodose samhällets behov och erhålla legitimitet. Vad en väsentlig hållbarhetsfråga är kan variera från en bransch till en annan, att studera och förstå likheter och skillnader mellan företags val av väsentlighetsaspekter är en viktig fråga som tidigare forskning inte har undersökts i större utsträckning. Syftet med denna studie att öka förståelse för väsenlighetsaspekter som offentliggörs i företagens hållbarhetsredovisningar utifrån Global Reporting Initiatives (GRI) riktlinjer. Det regelverk som ligger till grund för studien är GRI:s (G4) riktlinjer tillsammans med teorier såsom intressentteorin och legitimitetsteorin, samt en beskrivning av olika koncept bland annat Corporate Social Responsibility (CSR), Tripple Bottom Line (TBL), hållbar utveckling och hållbarhetsredovisning. För uppnå studiens syfte har en kvalitativ innehållsanalys används som metod, där tolv företags hållbarhetsredovisningar från konfektion- och skogsbranschen har granskats. I studiens empiri presenteras företagens väsentlighetsanalys som redogör för hur företagen identifierar sina väsentlighetsaspekter, vidare beskrivs deras val av väsentlighetsaspekter utifrån miljö- och socialkategorin. I analysen framförs vilka likheter och skillnader som finns mellan företagens val av väsentlighetsaspekter utifrån branschtillhörighet. Studiens slutsats är att det finns både likheter och skillnader mellan konfektion- och skogsföretagens val av väsentlighetsaspekter. Betydelsefulla och återkommande aspekter hos både branscherna var bland annat utsläpp, avlopp och avfall och mångfald och jämställdhet. Vidare visar resultatet att aspekterna både ur miljö- och socialkategorin redovisas i större utsträckning av företagen inom skogsbranschen. En förklaring till detta kan vara att branscher som har större miljöpåverkan såsom skogsbranschen redovisar flera aspekter inom båda kategorierna. Slutligen visar studien att konfektionsbranschen offentliggör mer information om verksamhetens sociala påverkan, en förklaring till detta kan vara att konfektionsbranschen har större socialpåverkan i jämförelse till miljöpåverkan.Abstract   Due to increased global crises and increased stakeholder awareness about business’ societal impacts sustainable development has become a central and important issue both for businesses and individuals. As a result of this companies have a responsibility to work sustainably, taking society and environment into consideration, through sustainability reporting companies try to satisfy the expectations of society and obtain legitimacy. The materiality of sustainability issues differ across one branch to another, to study and understand similarities and differences between companies’ selection of material aspects is an important question which previous research has not investigated to a greater extent. The purpose of this study is to increase understanding of the material aspects which is disclosed in companies’ sustainability reports based on Global Reporting Initiave’s (G4) guidelines. The guidelines used in this study is based on GRI’s (G4) framework, along with theories such as stakeholder and legitimacy theory and also a description of different concepts such as Corporate Social Responsibility (CSR), Tripple Bottom Line (TBL), sustainable development and sustainability reporting. In order to fulfill the purpose of the study, a qualitative content analysis has been used as a method for reviewing twelve companies' sustainability reports from the apparel and forestry sectors. The empirical section of the study presents the company's materiality analysis, which describes how companies identify their materiality aspects and also gives a further description of companies’ selection of material aspects from the environmental category and social category. The analysis identifies the similarities and differences between the companies' choice of material aspects based on sector affiliation. The study's conclusion is that there are both similarities and differences in the selection of material aspects between the companies in apparel and forestry sectors. Significant and recurring aspects for both sectors: emission, effluents and waste, diversity and equal opportunity. Furthermore, the result shows that the aspects from both the environmental and social categories are more widely reported by companies in the forestry sector. An explanation for this could be that sectors with greater environmental impact, such as the forestry sector report more aspects in both categories. Finally, the study shows that the apparel sector publishes more information about the social impact of the business. An explanation for this could be that the apparel sector has greater social impact in comparison to environmental impact.      

Routing flexibility for unequal–area stochastic dynamic facility layout problem in flexible manufacturing systems

It is indispensable that any manufacturing system is consistent with potential changes such as fluctuations in demand. The uncertainty also makes it more essential. Routing Flexibility (RF) is one of the necessities to any modern manufacturing system such as Flexible Manufacturing System (FMS). This paper suggests three mixed integer nonlinear programming models for the Unequal–Area Stochastic Dynamic Facility Layout Problems (UA–SDFLPs) by considering the Routing Flexibility. The models are proposed when the independent demands follow the random variable with the Poisson, Exponential, and Normal distributions. To validation of the proposed models, many small-sized test problems has solved that derived from a real case in literature. The large-sized test problems are solved by the Genetic Algorithm (GA) at a reasonable computational time. The obtained results indicate that the discussed models for the UA–SDFLPs are valid and the managers can take these models to the manufacturing floor to adapt to the potential changes in today's competitive market

A mathematical model for vehicle routing and scheduling problem with cross-docking by considering risk

Today, many companies after achieving improvements in manufacturing operations are focused on the improvement of distribution systems and have long been a strong tendency to optimize the distribution network in order to reduce logistics costs that the debate has become challenging. Improve the flow of materials, an activity considered essential to increase customer satisfaction. In this study, we benefit cross docking method for effective control of cargo flow to reduce inventory and improve customer satisfaction. Also every supply chain is faced with risks that threaten its ability to work effectively. Many of these risks are not in control but can cause great disruption and costs for the supply chain process. In this study we are looking for a model to collect and deliver the demands for the limited capacity vehicle in terms of disruption risk finally presented a compromised planning process. In fact, we propose a framework which can consider all the problems on the crisis situation for decision-making in these conditions, by preparing a mathematical model and software gams for the following situation in a case study. In the first step, the results presented in mode of a two-level planning then the problem expressed in form of a multi-objective optimization model and the results was explained

Estimation of Gaussian mixture models via tensor moments with application to online learning

In this paper, we present an alternating gradient descent algorithm for estimating parameters of a spherical Gaussian mixture model by the method of moments (AGD-MoM). We formulate the problem as a constrained optimisation problem which simultaneously matches the third order moments from the data, represented as a tensor, and the second order moment, which is the empirical covariance matrix. We derive the necessary gradients (and second derivatives), and use them to implement alternating gradient search to estimate the parameters of the model. We show that the proposed method is applicable in both a batch as well as in a streaming (online) setting. Using synthetic and benchmark datasets, we demonstrate empirically that the proposed algorithm outperforms the more classical algorithms like Expectation Maximisation and variational Bayes

Robust optimization in an agricultural closed-loop supply chain network design with a price and freshness-dependent demand:hybrid rat with particle swarm optimization algorithm

This study seeks to develop a closed-loop network for managing the pistachio Supply Chain (SC) under uncertainty. Then, a Mixed-Integer Linear Programming model is suggested to achieve optimal costs of the SC such transportation, production costs and CO2 emissions tax. It is assumed that the demand for the product depends on the freshness and price of the product and, to deal with uncertainty, a robust optimization approach is used. Furthermore, GAMS software as an exact solution method and four meta-heuristics algorithms including Whale Optimization Algorithm, Particle Swarm Optimization, Rat Swarm Optimizer and a new hybrid algorithm are used as the solution approach. The accuracy of the planned model is examined using a case study and to more measurement, a sensitivity analysis is performed. Finally, the computational time of the mentioned algorithms and their obtained results are compared. The numerical analysis showed that the hybrid algorithm, although having more computational time, is superior to others, which the results had a difference between 0.9 and 2.7% with the exact method. Therefore, it is showed that the hybrid approach is a valid approach to solve large-scale problems. Our findings are helpful for pistachio-producing countries.</p

Pedicle subtraction osteotomy in patient with congenital kyphosis

Abstract Introduction A disorder causes congenital kyphosis in the last stages of ossification and cartilage formation during embryonic development. The main treatment for this disease is surgery with various methods. The present study was performed to evaluate the results of the posterior surgery. Methods This study was a descriptive study comparing the results before and after surgery which was performed in 2022 on 14 patients with the congenital kyphosis referred to Al-Zahra Hospital in Isfahan. Initial assessments were performed, and the patient underwent surgery. The patients were re-evaluated immediately after surgery which were followed up and evaluated two years after surgery. Data were collected by a checklist and described and analyzed in SPSS software version 22. Results The mean age of the patients was 23.15 ± 13.24 years, 7 patients (50%) were male, and the mean duration of surgery was 405.85 ± 123.99 min. Seven patients (50%) were under 18 years old. No disease died and the highest T12 involvement was in 5 patients (35.8%). Sagittal Vertical Axis, Kyphosis Angle and Lumbar Lordosis decreased in two stages immediately after surgery and follow-up, which were statistically significant (P  0.05). The mean Kyphosis Angle were significantly different in adults, and children at follow-up stages (P < 0.05). Because one of the children had a device filler in the follow-up stage. Conclusions PSO can be used as a safe and effective technique to treat and correct Sagittal Vertical Axis, Kyphosis angle, Lumbar lordosis

The study of advanced oxidation process (UV/H2O2) performance in removal of the ceftriaxone antibiotic from aqueous solution

Background : The presence of antibiotics in water sources indicates inadequacy of conventional treatment processes for antibiotics removal. The objective of the present study is to investigate the effectiveness of the advanced oxidation process, UV/H2O2, in the removal of ceftriaxone from an aqueous solution on a laboratory scale. Materials and Methods: This experimental study was conducted on a lab scale in a reactor with a capacity of 5800 ml. Aqueous solutions containing ceftriaxone with concentrations of 9, 18, and 27 mg/l were produced. The effect of different variables including the initial concentrations of the antibiotic, pH, retention time, different lamp voltages, and H2O2 concentrations were investigated. The ceftriaxone concentrations were measured using HPLC method. Results: The results of the study showed that the UV/H2O2 method is able to remove 75% of a 9 mg/l concentration of ceftriaxone from an aqueous solution in 3 hours. The removal rates for ceftriaxone are affected by parameters such as pH, the initial concentration of ceftriaxone, the concentration of H2O2 and the intensity of UV radiations. Acidic pH (pH=3), low concentrations of ceftriaxone (9 mg/l), high H2O2 concentrations (15 mg/l) and higher radiation levels (36 Watt) resulted in higher removal rates. Conclusion: The advanced oxidation method UV/ H2O2 is able to effectively remove ceftriaxone from aqueous solutions under proper environmental conditions