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.      

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

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