Lignocellulosic biomass for bioethanol production: Current perspectives,potential issues and future prospects

During the most recent decades increased interest in fuel from biomass in the United States and worldwide has emerged each time petroleum derived gasoline registered well publicized spikes in price. The willingness of the U.S. government to face the issues of more heavily high-priced foreign oil and climate change has led to more investment on plant-derived sustainable biofuel sources. Biomass derived from corn has become one of the primary feedstocks for bioethanol production for the past several years in the U.S. However, the argument of whether to use food as biofuel has led to a search for alternative non-food sources. Consequently, industrial research efforts have become more focused on low-cost large-scale processes for lignocellulosic feedstocks originating mainly from agricultural and forest residues along with herbaceous materials and municipal wastes. Although cellulosic-derived biofuel is a promising technology, there are some obstacles that interfere with bioconversion processes reaching optimal performance associated with minimal capital investment. This review summarizes current approaches on lignocellulosic-derived biofuel bioconversion and provides an overview on the major steps involved in cellulosic-based bioethanol processes and potential issues challenging these operations. Possible solutions and recoveries that could improve bioprocessing are also addressed. This includes the development of genetically engineered strains and emerging pretreatment technologies that might be more efficient and economically feasible. Future prospects toward achieving better biofuel operational performance via systems approaches such as risk and life cycle assessment modeling are also discussed.     

The role of modelling in achieving information systems success: UML to the rescue?

Much computer science literature addresses the mechanics of the Unified Modelling Language (UML) and requirements modelling, but little research has addressed the role of UML in the broader organizational and project development context. This study uses a socio-technical approach to consider UML as a technology embedded in a social environment. In this study, project developers were interviewed in detail about their use of UML along with influences on their decisions to use this approach and the results of using it. Data were analyzed using causal mapping. Major findings included: (1) that definitions of success may differ by unit of analysis (e.g., developer, project, organization) and that the relationship among these definitions are complex; (2) a very large number of variables impacting project success were identified; (3) a number of important variables exist in complex (non-linear) relationships with project success; and (4) the majority of interviewees linked the use of UML to project success.     

Understanding information systems continuance: The case of Internet-based learning technologies

Our research model expanded the Bhattacherjee's IS continuance model by adding a moderating effect (IS habit) to IS continuance intention and IS continued usage, postulating direct links between satisfaction and IS continued usage, as well as between prior behavior and IS continued usage. The model was tested with an Internet-based learning technology in a longitudinal setting. Data collected from 505 students were examined using partial least squares analysis. The results presented strong support for the theoretical links of IS continuance model, and for the new moderating effect. Both satisfaction and prior behavior were found to have significant impact on IS continuance. In addition, our findings confirmed the theoretical argument that the strength of intention to predict continuance was weakened by a high level of IS habit.     

User switching of information technology: A theoretical synthesis and empirical test

As competing technological choices emerge in the marketplace, an inevitable consequence is user switching from one IT product or service to another. However, we know very little of this phenomenon or the key drivers of user switching. We examined the reasons for IT switching by proposing a model that synthesized and extended current theories of IT acceptance and customer satisfaction. We believed that IT switching was driven by user dissatisfaction with an incumbent product or service and the fact that the customer was aware of the availability of a potentially superior product or service. Further, to explain differential switching patterns across an adopter population, we posited personal innovativeness as an individual difference variable that moderated the effect of user dissatisfaction and relative advantage of a new IT on users’ switching intention. Our model was empirically validated using a longitudinal survey of web browser switching among student subjects. We hope that our study will generate researchers’ interest in an understudied area of research and that the model will serve as a starting point for furthering our understanding of IT switching.     

The membrane emulsification process—a review

Membrane emulsification has received increasing attention over the last 10 years, with potential applications in many fields. In the membrane emulsification process, a liquid phase is pressed through the membrane pores to form droplets at the permeate side of a membrane; the droplets are then carried away by a continuous phase flowing across the membrane surface. Under specific conditions, monodispersed emulsions can be produced using this technique. The purpose of the present paper is to provide a review on the membrane emulsification process including: principles of membrane emulsification, influence of process parameters and industrial applications. Small‐scale applications such as drug delivery systems, food emulsions, and the production of monodispersed microspheres are also included. Compared with conventional techniques for emulsification, membrane processes offer advantages such as control of average droplet diameter by average membrane pore size and lower energy input. Copyright © 2004 Society of Chemical Industry     

Factors motivating software piracy: a longitudinal study

The objective of this paper is to gain a better understanding of factors influencing software piracy. A model explaining the contribution of different factors to software piracy intention and its subsequent effect on actual software piracy is constructed based on established theories of human behavior. The model is then tested empirically in a longitudinal study with a survey. Findings show that social factors and beliefs concerning consequences of software piracy have significant effects on software piracy intentions. The data also show that while habits and facilitating conditions were significantly related to actual piracy behavior, intentions did not necessarily lead to the actual act of software piracy. The implications of the findings to research and practice are discussed.     

Selective assessment of judgmental inconsistencies in pairwise comparisons for group decision rating

Pairwise comparison methods are convenient procedures for providing a sound weight vector from a set of binary comparisons between elements to be rated. In such procedures, each decision maker is asked to separately consider pairs of elements which are not necessarily independent from each other. For this reason the votes collected are liable to contain inconsistencies. In this paper we are providing a selective indicator that focuses on the inconsistencies the decision group is willing to correct in conformity with its vote strategy.     

What makes consumers buy from Internet? A longitudinal study ofonline shopping

The objective of this study is to investigate the factors affecting online shopping. A model explaining the impact of different factors on online shopping intentions and behavior is developed based on the theory of planned behavior. The model is then tested empirically in a longitudinal study with two surveys. Data collected from 705 consumers indicate that subjective norms, attitude, and beliefs concerning the consequences of online shopping have significant effects on consumers' intentions to buy online. Behavioral control and intentions significantly influenced online shopping behavior. The results also provide strong support for the positive effects of personal innovativeness on attitude and intentions to shop online. The implications of the findings for theory and practice are discussed     

Antimicrobial strategies for limiting bacterial contaminants in fuel bioethanol fermentations

Bioethanol continues to be offered as a viable solution for complex problems ranging from global warming and national energy security to local economic development. Fuel bioethanol burns cleaner than gasoline, is derived from renewable agricultural products, and creates local jobs and income. In December 2007, President Bush signed into law the Energy Independence and Security Act, which increased the renewable fuel standard that was mandated under energy Policy Act of 2005 to 36 billion gallons by 2022.In order to achieve this goal, ethanol production would need to be generated primarily from corn and cellulosic materials. Bioethanol producers are currently involved in variety of technological innovations to reduce energy consumption and production costs, increased efficiency and reduced emissions using the best available control technologies. However, industrial ethanol fermentation is a non-sterile process and contaminant microorganisms can lead to a decrease in industrial productivity and significant economic loss. Currently, bioethanol industries use different antimicrobials including antibiotics to control the contaminants in the fermentors. The emergence of antibiotic resistance among contaminant bacteria in bioethanol fermentors warrants the need for alternative antimicrobials to retain bioethanol production at a profitable level. In addition more and more ethanol producers are seeking to generate distillers grains that can be labeled antibiotic free to be sold in international markets where some restrictions are already in place for reducing and/or eliminating antibiotics usage in animal feed. This review examines the contamination problems, various intervention methods, emergence of antibiotic resistance in contaminant bacteria, and potential alternative options to elucidate antimicrobial products from various natural sources. In particular, emphasis has been given for natural antibacterial products from plant derived products to suggest a new research avenue for the search of new, non-conventional antimicrobial agents to control the contamination problem in the fuel bioethanol industries.     

3D Social Virtual Worlds: Research Issues and Challenges

Today's social virtual worlds (SVW) are beginning to realize Stephenson's vision of the metaverse: a future massive network of interconnected digital worlds. Tens of millions of people already use these kinds of environments to communicate, collaborate, and do business. Big companies are also moving into these digital realms. Thus, in a context in which the Web is becoming increasingly social, we believe that SVWs are beginning to shape the knowledge-based and glo balized societies and economies of tomorrow. Obviously, an urgent need exists to further understand SVWs and their implications for theory and practice. This article constitutes a first attempt to bring researchers into some of the business, social, technical, legal, and ethical issues related to SVWs. We anticipate that researchers will need to build new theories and concepts for SVWs, to explore the frontiers between reality and virtuality.