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Article
Publication date: 7 June 2020

Yilu Gong, Tantan Shao and Lijun Chen

Fluorine materials have received the keen attention of many researchers because of their water repellency and low surface free energy. The purpose of this paper is to prepare…

Abstract

Purpose

Fluorine materials have received the keen attention of many researchers because of their water repellency and low surface free energy. The purpose of this paper is to prepare fluorine-containing soap-free acrylic emulsion, which sodium allyoxypropyl hydroxypropyl sulfonate (COPS-1) and anionic emulsifier sodium a-alkenyl sulfonate (a-AOS) were combined as polymerizable emulsifier, and undecylenic acid (UA) and dodecafluoroheptyl methacrylate(DFMA) were introduced as functional monomer.

Design/methodology/approach

The fluorinated polyacrylate emulsion was successfully prepared by semi-continuous seed emulsion polymerization, wherein the main monomers were methyl methacrylate (MMA) and butyl methacrylate (BA), and the initiator was potassium persulfate (KPS). Sodium alloxypropyl sulfonate (COPS-1) and an anionic emulsifier sodium a-alkenyl sulfonate (a-AOS) were compounded as a polymerizable emulsifier. Besides, undecylenic acid (UA) and dodecafluoroheptyl methacrylate (DFMA) were introduced as the functional monomers.

Findings

The optimum recipe of preparing the modified latex is as follows: the amount of emulsifier was 4%, the ratio of emulsifier (COPS-1: AOS) was 3: 1, and the content of initiator was 0.6%. In this case, the conversion rate of acrylic polymer emulsion was high and the polymerization stability was good. When the amount of monomer UA was 2% and the amount of DFMA was 4%, the overall performance of the emulsion was the best.

Originality/value

The fluorine-containing soap-free acrylic emulsion is prepared via semi-continuous seeded emulsion polymerisation, which sodium allyoxypropyl hydroxypropyl sulfonate (COPS-1) and anionic emulsifier sodium a-alkenyl sulfonate (a-AOS) were combined as polymerizable emulsifier, and undecylenic acid (UA) and dodecafluoroheptyl methacrylate (DFMA) were introduced as functional monomer. There are two main innovations. One is that the fluorine-containing soap-free acrylic emulsion is prepared successfully. The other is that the undecylenic acid is introduced as functional monomer.

Details

Pigment & Resin Technology, vol. 50 no. 1
Type: Research Article
ISSN: 0369-9420

Keywords

Book part
Publication date: 1 January 2005

Daniel Bodansky

Although the general theory of greenhouse warming has been understood by scientists since the end of the nineteenth century, an international regime to address the problem of…

Abstract

Although the general theory of greenhouse warming has been understood by scientists since the end of the nineteenth century, an international regime to address the problem of climate change began to develop only in the late 1980s.1 In the decade and a half since then, the regime has undergone a remarkable evolution. In 1992, states adopted the UN Framework Convention on Climate Change (UNFCCC), which took effect in 1994 and serves as the “constitution” for the international climate change regime.2 In 1997, the UNFCCC was supplemented by the Kyoto Protocol, which requires industrialized countries to reduce their emissions of carbon dioxide and five other gases that contribute to the greenhouse effect (so-called “greenhouse gases” or GHGs for short). And the 2001 Marrakesh Accords further elaborate the Kyoto Protocol's regulatory regime, setting forth detailed rules for how the Kyoto Protocol will operate.

Details

Perspectives on Climate Change: Science, Economics, Politics, Ethics
Type: Book
ISBN: 978-0-76231-271-9

Case study
Publication date: 30 April 2020

Armando Borda, Gonzalo Guerra García, Carlos Cordova and Miguel Cordova

The learning outcomes are as follows: to analyze host market characteristics and consumer behavior to develop sound value propositions; to distinguish the characteristics of…

Abstract

Learning outcomes

The learning outcomes are as follows: to analyze host market characteristics and consumer behavior to develop sound value propositions; to distinguish the characteristics of traditional retail as opposed to the ones of modern retail; to identify the potential benefits and challenges of working with traditional retail; to discuss how informality may affect business relations; and to identify potential avenues to align divergent interests between the focal firm and traditional retailers.

Case overview/synopsis

The case described the situation faced by French International Company (FICO), a leading manufacturer of cigarettes, after the acquisition of Fosforera Colombiana (FOCOSA) in Colombia. FICO aimed to leverage the leadership position of FOCOSA and of its flagship brand Ferrari Lights that possess a 60% market share. However, after just a few months, it was clear that the acquired subsidiary was not performing adequately. The financial results obtained were disastrous. To face this situation, FICO appointed as the new marketing director to Waldo Tarantini who has experienced dealing with informal markets. To be aligned to the Colombian consumption pattern of five cigarettes daily, Waldo decided to launch a new presentation of the leading brand denominated Ferrari five, a package of 5 cigarettes at COP 1000. Considering that more than 60% of the sale can be explained by traditional retail, it was mandatory to secure its participation. Nevertheless, traditional retailers obtained up to 56% margin by selling single sticks. Waldo and his team rapidly needed to craft a commercial strategy to secure the participation of traditional retailers in a market plagued by informality, smuggling products and lack of control from national authorities.

Complexity academic level

The case is intended to be used at the early stages of post-graduate studies and in executive education programs addressing issues such as emerging markets, informality, the base of the pyramid, trade marketing and product launches. In particular, the case can be used in MSc in Marketing’s students, first-year MBA students or executives following short courses. The field of studies in which the case should be taught is marketing or trade marketing in particular when analyzing emerging economies.

Supplementary materials

Teaching notes are available for educators only.

Subject code

CSS 8: Marketing.

Book part
Publication date: 10 July 2006

Dimiter M. Dimitrov

Knowledge about cognitive operations and processes (COPs) required for success (1=correct, 0=incorrect) on test items or learning tasks is very important for in-depth…

Abstract

Knowledge about cognitive operations and processes (COPs) required for success (1=correct, 0=incorrect) on test items or learning tasks is very important for in-depth understanding of the nature of student performance and the development of valid instruments for its measurement. A key problem in obtaining such knowledge is the validation of hypothesized COPs and their role in the measurement properties of test items. To provide validation feedback for both normally achieving students and students with learning disabilities, it is important to obtain information on the validity of the COPs for students at different ability levels and individual test items (or tasks). To address this issue, the present chapter introduces a method of estimating the probability for correct performance on individual COPs at fixed ability levels thus providing validity information across ability levels and individual test items. When item response theory (IRT) estimates of the item parameters are known (e.g., in a test bank of IRT calibrated items or published research), the proposed validation method does not require information about raw (or ability) scores of examinees. This method is illustrated for algebra test items and reading comprehension test items calibrated in IRT.

Details

Applications of Research Methodology
Type: Book
ISBN: 978-0-76231-295-5

Article
Publication date: 10 August 2018

Nesrin Köken

The purpose of this paper is to prepare poly[allyl amino bis(methylene phosphonic acid)-ran-acrylic acid]s by two different routes. In the first route, poly(allyl…

Abstract

Purpose

The purpose of this paper is to prepare poly[allyl amino bis(methylene phosphonic acid)-ran-acrylic acid]s by two different routes. In the first route, poly(allyl amine-ran-acrylic acid)s were produced by radical copolymerization of a mixture of ally amine and acrylic acid, then converted into poly[allyl amino bis(methylene phosphonic acid)-ran-acrylic acid]s by the Mannich reaction with a mixture of formaldehyde and phosphonic acid. In the second route, allyl amino bis(methylene phosphonic acid) monomer was synthesized and copolymerised with acrylic acid. The aim of this work is to produce low-molecular-weight copolymer with the low amount of nitrogen and phosphorous having better scale inhibiting performance than commercial low-molecular-weight poly(acrylic acid)s.

Design/methodology/approach

Poly(allyl amine-ran-acrylic acid)s were prepared by radical copolymerisation of a mixture of ally amine and acrylic acid, and the molecular weight of copolymers was regulated by using an effective chain transfer compound and the formed copolymer was reacted with a mixture of formaldehyde and phosphorous acid. Allyl amino bis(methylene phosphonic acid) monomer was prepared and then copolymerised with acrylic acid using radical initiators.

Findings

Poly[allyl amino bis(methylene phosphonic acid)-ran-acrylic acid] produced with both routes, especially low-molecular weight ones have better anti-scaling performance than low-molecular-weight commercial poly(acrylic acid).

Research limitations/implications

By using an excess of formaldehyde and phosphonic acid, a limited increase in the conversion of amine groups of poly(allyl amine-ran-acrylic acid) to amino methylene phosphonic acid groups was achieved, so unreacted amine groups were always present in the structure of the final copolymers.

Practical implications

The low-molecular-weight poly[allyl amino bis(methylene phosphonic acid)-ran-acrylic acid] may be used as a better anti-scaling polymer in industry.

Social implications

The low-molecular-weight poly[allyl amino bis(methylene phosphonic acid)-ran-acrylic acid] is an alternative polymer for scale inhibition in the water boilers.

Originality/value

The low-molecular-weight poly[allyl amino bis(methylene phosphonic acid)-ran-acrylic acid] copolymers containing both carboxylic acid and amino bis(methylene phosphonic acid) are more effective anti-scaling additives than poly(acrylic acid)s in water boilers.

Article
Publication date: 21 April 2020

Wanjie Hu, Jianjun Dong, Bon-Gang Hwang, Rui Ren and Zhilong Chen

Underground logistics system (ULS) is recognized as sustainable alleviator to road-dominated urban logistics infrastructure with various social and environmental benefits. The…

Abstract

Purpose

Underground logistics system (ULS) is recognized as sustainable alleviator to road-dominated urban logistics infrastructure with various social and environmental benefits. The purpose of this study is to propose effective modeling and optimization method for planning a hub-and-spoke ULS network in urban region.

Design/methodology/approach

Underground freight tunnels and the last-mile ground delivery were organized as a hierarchical network. A mixed-integer programming model (MIP) with minimum system cost was developed. Then a two-phase optimization schema combining Genetic-based fuzzy C-means algorithm (GA-FCM), Depth-first-search FCM (DFS-FCM) algorithm and Dijkstra algorithm (DA), etc. was designed to optimize the location-allocation of ULS facilities and customer clusters. Finally, a real-world simulation was conducted for validation.

Findings

The multistage strategy and hybrid algorithms could efficiently yield hub-and-spoke network configurations at the lowest objective cost. GA-FCM performed better than K-means in customer-node clustering. The combination of DFS-FCM and DA achieved superior network configuration than that of combining K-means and minimum spanning tree technique. The results also provided some management insights: (1) greater scale economies effect in underground freight movement could reduce system budget, (2) changes in transportation cost would not have obvious impact on ULS network layout and (3) over 90% of transportation process in ULS network took place underground, giving remarkable alleviation to road freight traffic.

Research limitations/implications

Demand pairs among customers were not considered due to lacking data. Heterogeneity of facilities capacity parameters was omitted.

Originality/value

This study has used an innovative hybrid optimization technique to address the two-phase network planning of urban ULS. The novel design and solution approaches offer insights for urban ULS development and management.

Details

Engineering, Construction and Architectural Management, vol. 27 no. 8
Type: Research Article
ISSN: 0969-9988

Keywords

Book part
Publication date: 1 January 2005

Dale Jamieson

In this chapter I claim that climate change poses important questions of global justice, both about mitigating the change that is now under way and about adapting to its…

Abstract

In this chapter I claim that climate change poses important questions of global justice, both about mitigating the change that is now under way and about adapting to its consequences.1 I argue for a mixed policy of mitigation and adaptation, and defend one particular approach to mitigation. I also claim that those of us who are rich by global standards and benefit from excess emissions have strenuous duties in our roles as citizens, consumers, producers, and so on to reduce our emissions and to finance adaptation.

Details

Perspectives on Climate Change: Science, Economics, Politics, Ethics
Type: Book
ISBN: 978-0-76231-271-9

Article
Publication date: 19 March 2021

Wai Tung Ho and Fu Wing Yu

This study aims to apply association rule mining (ARM) to uncover specific associations between operating components of a chiller system and improve its coefficient of performance…

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Abstract

Purpose

This study aims to apply association rule mining (ARM) to uncover specific associations between operating components of a chiller system and improve its coefficient of performance (COP), hence reducing the electricity use of buildings with central air conditioning.

Design/methodology/approach

First, 13 operating variables were identified, comprising measures of temperatures and flow rates of system components and their switching statuses. The variables were grouped into four bins before carrying out ARM. Strong rules were produced to associate the variables and switching statuses with different COP classes.

Findings

The strong rules explain existing constraints on practising chiller sequencing and prioritise variables for optimisation. Based on strong rules for the highest COP class, the optimal operating strategy involves rescheduling chillers and their associated components in pairs during a high load operation. Resetting the chilled water supply temperature is the next best strategy, followed by resetting the condenser water entering temperature, subject to operating constraints.

Research limitations/implications

This study considers the even frequency method with four bins only. Replication work can be done with other discretisation methods and different numbers of classes to compare potential differences in the bin ranges of the optimised variables.

Practical implications

The strong rules identified by ARM highlight associations between variables and high or low COPs. This supports the selection of critical variables and the operating status of system components to maximise the COP. Tailor-made optimisation strategies and the associated electricity savings can be further evaluated.

Originality/value

Previous studies applied ARM for chiller fault detection but without considering system performance under the interaction of different components. The novelty of this study is its demonstration of ARM’s intelligence at discovering associations in past operating data. This enables the identification of tailor-made energy management opportunities, which are essential for all engineering systems. ARM is free from the prediction errors of typical regression and black-box models.

Article
Publication date: 1 December 1995

Robert J. Kaminski and David W.M. Sorensen

Uses data on 1,550 nonlethal assaults recorded by Baltimore County Police Department. Examines factors that are associated with the likelihood of officer injury after an assault…

1123

Abstract

Uses data on 1,550 nonlethal assaults recorded by Baltimore County Police Department. Examines factors that are associated with the likelihood of officer injury after an assault. Notes that factors affecting the probability of assault do not necessarily correspond with the factors that affect the likelihood of injury. Analyzes a broader spectrum of contributory factors than those addressed by other research. Finds inter alia that greater officer proficiency in unarmed defensive tactics may reduce their assault‐related injuries, since most incidents do not involve arms; that in‐service training should be biased toward less experienced officers who are at greater risk; that officer height is a significant variable; that many officers suffer multiple attacks; that domestic disturbances do not rank higher than other dangers, but that this may reflect the possibility that officers anticipate potential violence and take better precautions before attending the scene.

Details

American Journal of Police, vol. 14 no. 3/4
Type: Research Article
ISSN: 0735-8547

Keywords

Article
Publication date: 16 December 2022

Luis E. Arango and Ingri K. Quevedo

The authors estimate the determinants of the value of purchases of semi-durable goods using permanent and transitory income, and the demographic characteristics of customers. The…

Abstract

Purpose

The authors estimate the determinants of the value of purchases of semi-durable goods using permanent and transitory income, and the demographic characteristics of customers. The purpose is to identify whether individuals face remaining liquidity constraints, and how this friction affects their purchases.

Design/methodology/approach

This study uses anonymized data of 516,525 credit card holders, with more than 7,501,065 records of purchases between 2010 and 2015. The authors decompose the income of individuals into permanent and transitory components to test the prevalence of the life cycle–permanent income hypothesis (LC–PIH). Determinants of the value of purchases for constrained and unconstrained consumers are estimated, considering the period in which individual characteristics are valid, the decisions not to make purchases in some months, and the potential endogeneity of the interest rate and the transitory component of income.

Findings

The authors present evidence of liquidity constraints for individuals who have used a high percentage of the credit limit on their cards. For these restricted customers, the value of purchases is inelastic to the interest rate, whereas the response is sizable for customers who are less restricted. The restricted customers increase the value of purchases when faced with increases in their credit limit. The elasticity of the value of purchases of semi-durable goods to permanent income is less than that for transitory income; regardless of the constraints, this still supports the LC–PIH.

Research limitations/implications

This credit card is targeted at low- and middle-income individuals in Bogotá. Although the results might be considered as indicative of the behavior of those with similar characteristics in Colombia, the authors regard this work as the study of a particular case. A limitation of this work is that the authors do not have alternative sources of credit at an individual level.

Practical implications

The broad credit channel of monetary policy does not apply to the restricted customers. This should be considered not only by the monetary authority, to understand the true extent of this policy, but also by the financial institutions that use this business model. The monetary authority should be cautious not to overreact when intervening in the money market to try to prompt an adequate consumer response.

Social implications

Financial institutions have the policy of modifying the credit limits of their customers' credit cards which affects the well-being of restricted customers. Given that the card is aimed at low and middle income individuals, the credit limits of customers who use a high percentage of their credit limit might be increased.

Originality/value

This is the first paper to study liquidity restrictions with a retail credit card in Colombia and Latin America using information on customers' characteristics. The results are highly relevant for the implementation of monetary policy.

Details

International Journal of Emerging Markets, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1746-8809

Keywords

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