Ion exchange membrane systems: Modeling and optimization for salinity gradient energy generation

Energy can be sustainably generated by harnessing natural salinity gradients in coastal environments. Power derived from the mixing of freshwater and seawater can be recovered as electrical energy by regulated ion transport in reverse electrodialysis (RED) systems. Cation exchange membranes and anion exchange membranes, known together as ion exchange membranes (IEMs), are crucial components to the energy generation efficiency in RED stacks. Considering the fundamental nature of electrochemical systems, it is conceivable that membrane functional properties, including ionic conductivity and permselectivity, have significant effects on RED energy performance. A better understanding of these determining factors is therefore critical to advance commercialization feasibility. This study focused on advancing the understanding of IEMs through modeling, simulation and experimental validation in addition to novel approaches for RED energy performance improvement. Specifically, conductivity gains were realized through implementation of ion exchange resin in low-concentration compartments. Mathematical modeling and experimental validation were leveraged to infer crucial factors in membrane conductivity and other physical property determinations. In addition, this framework was extended to illuminate the role of nanoparticle introduction during the synthesis process. Modeling and simulation results were successful in revealing the underlying dependencies of IEM characterization and improving the system energy performance. A majority of these theories and simulations are generalized – potentially yielding broad impacts to similar membrane-based systems and processes (e.g., electrodialysis).Ph.D

U.S. Luxury Fashion Consumption: Factors Affecting Attitude and Purchase Intent

With the widespread economic downturn, luxury fashion goods sales in the U.S. seem to be at risk. However, the U.S. remains the world’s largest luxury goods market, accounting for over one-fourth of the overall value sales of luxury goods in 2012 (CPP-LUXURY.COM, 2012). As the U.S. economic situation slowly recovers, the growth of the U.S. luxury goods market is expected to be more positive (Silverstein, 2012). In line with this issue, luxury retailers are well advised to understand the U.S. consumers’ attitude towards luxury goods and purchase intent and the differences and similarities to consumers’ attitudes in other regions to better address the customers’ unique characteristics

Enhancing fouling resistance of polyethylene anion exchange membranes using carbon nanotubes and iron oxide nanoparticles

This work presents the enhancement of organic fouling resistance of nanocomposite anion exchange membranes made from a commercial polyethylene anion exchange membrane and a negative thin layer. This layer is composed of sulfonated poly (2,6-dimethyl-1,4-phenylene oxide) (sPPO) and two nanomaterials of different geometry and composition, oxidized multi-walled carbon nanotubes CNTs-COO− (0.2% g g− 1 to 0.8% g g− 1) or sulfonated iron oxide nanoparticles Fe2O3-SO42 − (0.2% g g− 1 to 0.6% g g− 1). The novel nanocomposite membranes showed a relevant improvement in fouling resistance caused by the modification of some physicochemical characteristics of membrane surface such as charge, roughness and hydrophilicity. The nanocomposite layer did not show a change in the membrane resistance. No remarkable differences were detected when changing the nanomaterial during characterization of nanocomposite membranes. The optimized loading of iron oxide nanoparticles and carbon nanotubes at 0.4% and 0.6% improved membrane fouling resistance by 45% and 53%, respectively. The improved fouling resistance of the best nanocomposite membranes AM-0.6CNTs remained after 12 h of operation. Energy savings between 49% and 60% were also achieved.Financial support from MICINN under project CTM2014-57833-R and CTQ2013-48280-C3-1-R-D is gratefully acknowledged. The authors thank the Ministry of Education for the FPI grant BES-2012-053461 and the scholarship EEBB-I-15-10268. In addition, this research was partially supported by the U.S. National Science Foundation CBET-1235166

Shopping Orientations, Retail Attributes and Retail Format Choice Among Generation Y Apparel Shoppers

Generation Y shoppers represent a significant percentage of the population, are recognized as an important and distinctive market segment, and demonstrate differences in shopping styles as compared to previous generational cohorts (Pentecost and Andrews, 2010; Bakewell and Mitchell, 2003, TRU, 1999), yet there is a lack of extant patronage research specific to the cohort. While initial steps to understand Generation Y shoppers have been taken (e.g., Seock and Bailey, 2008; Carpenter, Moore, Turner and Joshi, 2005), few extant studies move forward to empirically link shopping orientations to specific patronage behaviors among Generation Y shoppers. This study explores shopping orientations, desired retail attributes and retail format choice among a sample of Generation Y apparel shoppers in the U.S. (N = 215). The research links shopping orientations (e.g., price consciousness, brand/fashion consciousness, brand loyalty) and important retail attributes (e.g., sales staff, atmosphere, service, pricing, product selection, location) to retail format choice within eleven distinct retail formats (upscale department stores, traditional department stores, value department stores, specialty stores, specialty fast fashion stores, discounters, off-price stores, factory outlets, Internet only retailers, mail order catalogs, and television shopping). The findings provide guidance to both academics and retailers with regard to approaching and attracting Generation Y shoppers

Polynomial stability of the Rao-Nakra beam with a single internal viscous damping

International audienc

U.S. Luxury Fashion Consumption: Factors Affecting Attitude and Purchase Intent

With the widespread economic downturn, luxury fashion goods sales in the U.S. seem to be at risk. However, the U.S. remains the world’s largest luxury goods market, accounting for over one-fourth of the overall value sales of luxury goods in 2012 (CPP-LUXURY.COM, 2012). As the U.S. economic situation slowly recovers, the growth of the U.S. luxury goods market is expected to be more positive (Silverstein, 2012). In line with this issue, luxury retailers are well advised to understand the U.S. consumers’ attitude towards luxury goods and purchase intent and the differences and similarities to consumers’ attitudes in other regions to better address the customers’ unique characteristics.</p

Analysis of College Girls and Fashion Proportion in Mademoiselle, 1960-1974

The period of the 1960s and 1970s was a transitional era characterized by the Vietnam War, Civil Rights, ambiguous gender roles, and the increased use of recreational drugs. It was also a time marked by great changes for women, The approval of the oral contraceptive pill, the 1963 release of The Feminine Mystique, and President John F. Kennedy's Presidential Commission on the status of Women, which spoke to gender inequality, ushered in a second-wave of feminism. In addition to challenges, such as official legal inequalities, women gained greater opportunities, as a larger percentage of American women than ever before attended college and entered the labor force. During this period, young women in particular used appearance to express their identities and individuality. Pas researchers examined proportion of women's daywear and changes in females' roles from 1945 to 1995 in Vogue and found that the proportion of women's fashion was influenced by the increasing diversity and complexity of women's roles. Due to the great transitions of the 1960s and 1974, the researchers were interested in exploring how proportions were expressed in a magazine dedicated to college women during this time.This proceeding is from 70th Annual Conference of the International Textile and Apparel Association (2013): pp. 35-36. Posted with permission.</p

Enhanced Ionic Conductivity and Power Generation Using Ion-Exchange Resin Beads in a Reverse-Electrodialysis Stack

Reverse electrodialysis (RED) is a promising technique for harvesting energy by mixing seawater with river water. The energy production is usually limited by ionic conductivity in dilute compartments of a RED system. Novel tests were conducted in this research, which used ion-exchange resin beads (IERB) to replace nonconductive spacer fabrics in RED compartments with dilute NaCl solution in a modified stack containing Fumasep FKS and Fumasep FAS membranes. We compared the conductivity of an IERB packed bed with that of an inert glass-beads-packed bed as a control to confirm IERB’s effectiveness. When applied in a RED system, IERB decreased the stack resistance by up to 40%. The maximum gross power density improved by 83% in the RED stack compared to that in a regular RED stack at 1.3 cm/s average linear flow velocity. IERB-filled stack resistance was modeled. The model results fit well with experimental data, thereby confirming the effectiveness of the new approach presented here. The net power density is also estimated based on the measured pressure drop and pumping energy model. Both gross and net power density was improved by over 75% at higher flow rate. A net power density of 0.44 W/m² was achieved at a cell thickness of 500 μm. To the best of our knowledge, this research is the first to study the impact of IERB on power generation and establishes a new approach to improving the power performance of a RED system

Analysis of College Girls and Fashion Proportion in Mademoiselle, 1960-1974

The period of the 1960s and 1970s was a transitional era characterized by the Vietnam War, Civil Rights, ambiguous gender roles, and the increased use of recreational drugs (Rielly, 2003). It was also a time marked by great changes for women. The approval of the oral contraceptive pill, the 1963 release of The Feminine Mystique, and President John F. Kennedy’s Presidential Commission on the Status of Women, which spoke to gender inequality, ushered in a second-wave of feminism.</p