Sustainability metrics for eco-technologies assessment, part I: preliminary screening

This work presents a preliminary screening of eco-technologies for dimethyl carbonate (DMC) production. Through sustainability metrics, the assessment of six different chemical routes allows comparisons according to economical and environmental criteria, to determine the most sustainable route. CO₂ sequestration potential is also considered. The alternatives are scored according to the adopted metrics, leading to the decision of a suitable route based on economic and environmental grounds, prioritizing pollution-preventing technologies herein referred to as eco-technologies. Casting of technologies was based on alternatives available in the literature: Route 1 production of DMC from methanol and phosgene [Ono in Pure Appl Chem 68(2):367–375, 1996]; Route 2 production of DMC from methyl nitrite and CO [Ono in Pure Appl Chem 68(2):367–375, 1996]; Route 3 production of DMC from CO and methanol [Ono in Pure Appl Chem 68(2):367–375, 1996]; Route 4 production of DMC from urea and methanol (Wang et al. in Ind Eng Chem Res 46:8972–8979, 2007); Route 5 production of DMC from ethylene oxide and CO₂ [Ono in Pure Appl Chem 68(2):367–375, 1996]; Route 6 production of DMC from CO₂ and methanol (Choi et al. in Green Chem 4:230–234, 2002). The analysis shows that Routes 4 and 5 combine intermediate values of the total (sustainability) score, CO₂ sequestration potential and industrial feasibility, therefore entitled as eco-technologies, based on the adopted metrics. Although the two technologies are potentially ecological, they are recommended for a more rigorous analysis on the grounds of process simulation and life cycle analysis.     

Beta autoregressive moving average models

We build upon the class of beta regressions introduced by Ferrari and Cribari-Neto (J. Appl. Stat. 31:799–815, 2004) to propose a dynamic model for continuous random variates that assume values in the standard unit interval (0,1). The proposed βARMA model includes both autoregressive and moving average dynamics, and also includes a set of regressors. We discuss parameter estimation, hypothesis testing, goodness-of-fit assessment and forecasting. In particular, we give closed-form expressions for the score function and for Fisher’s information matrix. An application that uses real data is presented and discussed.     

Environmental and risk screening for prioritizing pollution prevention opportunities in the U.S. printed wiring board manufacturing industry

Modern manufacturing of printed wiring boards (PWBs) involves extensive use of various hazardous chemicals in different manufacturing steps such as board preparation, circuit design transfer, etching and plating processes. Two complementary environmental screening methods developed by the U.S. EPA, namely: (i) the Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts (TRACI) and (ii) Risk-Screening Environmental Indicators (RSEI), are used to quantify geographic and chemical environmental impacts in the U.S. PWB manufacturing industry based on Toxics Release Inventory (TRI) data. Although the release weight percentages of industrial chemicals such as methanol, glycol ethers and dimethylformamide comprise the larger fraction of reported air and water emissions, results indicate that lead, copper and their compounds' releases correspond to the highest environmental impact from toxicity potentials and risk-screening scores. Combining these results with further knowledge of PWB manufacturing, select alternative chemical processes and materials for pollution prevention are discussed. Examples of effective pollution prevention options in the PWB industry include spent etchant recovery technologies, and process and material substitutions. In addition, geographic assessment of environmental burden highlights states where promotion of pollution prevention strategies and emissions regulations can have the greatest effect to curb the PWB industry's toxic release impacts.     

A new green index as an overall quantitative green performance indicator of a facility

Green assessment tools such as the Building Research Establishment Environmental Assessment Method, Leadership in Energy and Environmental Design, Comprehensive Assessment System for Building Environmental Efficiency, GREEN STAR and HK-BEAM have been used worldwide. These tools, which utilise qualitative, credit-based rating system have several limitations. Firstly, they can only provide a relative measure of the greenness of a facility. Secondly, there is the possibility that the ratings assigned may differ from one user to another depending on the needs and priorities of an organisation, a country, or a region. Several studies have also highlighted that such credit-based systems involve piece-meal (Zuo and Zhou in Renew Sustain Energy Rev 30:271–281, 2014), as opposed to integrated evaluation of the green criteria, and the greenness of a facility. This paper proposes a new Green Index (GI) as a tool for assessing the level of greenness of a facility that overcomes the aforementioned limitations. The use of stock market composite index as a basis for the GI development has enabled an established tool for assessing stock market performances to progress into the domain of industrial and commercial facility management. Development of the GI involves two steps, namely the development of a weighting scheme using the factor analysis approach, followed by the composite GI formulation that is based on the stock market composite index. The developed Green Index is based on quantitative analysis and measurement of parameters, and hence, reflect the actual measure of the overall impact of a facility on the environment. With only a single indicator to represent multiple green elements, it makes it easier for facility managers to effectively and quantitatively monitor, analyse, compare and benchmark the actual level of greenness of facilities in new systems designs or a retrofit or conservation programme.     

A time-discrete model for dynamic fracture based on crack regularization

We propose a discrete time model for dynamic fracture based on crack regularization. The advantages of our approach are threefold: first, our regularization of the crack set has been rigorously shown to converge to the correct sharp-interface energy Ambrosio and Tortorelli (Comm. Pure Appl. Math., 43(8): 999–1036 (1990); Boll. Un. Mat. Ital. B (7), 6(1):105–123, 1992); second, our condition for crack growth, based on Griffith’s criterion, matches that of quasi-static settings Bourdin (Interfaces Free Bound 9(3): 411–430, 2007) where Griffith originally stated his criterion; third, solutions to our model converge, as the time-step tends to zero, to solutions of the correct continuous time model Larsen (Math Models Methods Appl Sci 20:1021–1048, 2010). Furthermore, in implementing this model, we naturally recover several features, such as the elastic wave speed as an upper bound on crack speed, and crack branching for sufficiently rapid boundary displacements. We conclude by comparing our approach to so-called “phase-field” ones. In particular, we explain why phase-field approaches are good for approximating free boundaries, but not the free discontinuity sets that model fracture.     

Top journals selectivity index and “me-too” drugs

To assess the probability of success of an analgesic drug we have proposed a bibliometric indicator, the Top Journals Selectivity Index (TJSI) (Kissin 2011). It represents the ratio (as %) between the number of all types of articles on a particular drug in the top 20 biomedical journals and the number of articles on that drug in all (>5,000) journals covered by Medline over the first 5 years after that drug’s introduction. The aim of this study was to demonstrate that TJSI may be used for the assessment of follow-on drugs (those that follow a first-in-class drug). The study tested two hypotheses. First, TJSI can detect the difference (in the same class) between drugs with distinguishing features and drugs without them (“me-too” drugs) better than other publication indices, i.e., the number of all types of articles on a drug in journals presented by Medline (AJI), and the number of articles covering only randomized controlled trials (RCT). Second, there is a relationship between the TJSI of “me-too” drugs and the order (sequential number) in which those drugs reached the market. The study was based on drug classes approved for marketing between the 1960’s and the early 2000’s. The eight classes that had 4 or more drugs were included for analysis. Five specific indicators were used to determine drug’s distinguishing pharmacological properties. It was found that TJSI can detect the difference between follow-on drugs with distinguishing features and those without them better than the other publication indices (AJI or RCT). Our analysis also demonstrated a negative correlation (r = −0.372, p = 0.014) between the TJSI of drugs without distinguishing features (“me-too” drugs) and the order of the drug’s market entry. This implies that TJSI could be useful for the assessment of situations with multiple market entrants in the same class when a new addition has a questionable value.     

Can a bibliometric indicator predict the success of an analgesic?

In the assessment of success of new analgesic drugs over the past 50 years (Kissin, Anesth Analg 110:780–789, 2010) we observed a difference in the publication response to a new drug between biomedical journals in general and top journals: number of published articles on a drug increased (and declined) more rapidly in the top journals. Based on this phenomenon we present a new publication indicator—the Top Journal Selectivity Index (TJSI). It represents the ratio between the number of all types of articles in the top 20 biomedical journals and the number of articles in all (>5,000) journals covered by Medline, over 5 years after a drug’s introduction. Ten analgesics developed during the period 1986–2009 were selected for analysis. Three publication indices were used for assessment: the number of all types of articles presented in Medline, the number of articles covering only randomized controlled trials (RCT), and the Top Journal Selectivity Index. We also assessed the success score in the development of these analgesics based on the following criteria: novelty of molecular target, analgesic efficacy, and response by the pharmaceutical market. The relationships between the publication indices and analgesic’s success score were determined with the use of the Pearson correlation coefficient. Positive relationship was found only with the Top Journal Selectivity Index (r = 0.876, p < 0.001). We suggest that this index can predict success in drug development at least in the field of analgesics.     

John Bardeen and the Theory of Superconductivity: A Study of Insight,Confidence, Perseverance,and Collaboration

A biographical narrative of John Bardeen’s study of superconductivity from the 1930s through 1957, when he and his postdoc Leon Cooper and his graduate student J. Robert Schrieffer put forth BCS theory. This paper, adapted from L. Hoddeson and V. Daitch [1].     

The effect of indentation-induced microcracks on the elastic modulus of hydroxyapatite

The presence of microcracks in materials affects a wide range of mechanical properties including elastic modulus, Poisson’s ratio, fracture strength, and fracture toughness. The microcrack-induced reductions of the Young’s modulus, E, and Poisson’s ratio, υ, are functions of the size, geometry, and number density of microcracks. In this study, an array of Vickers indentation-induced microcracks was placed on the surfaces of two hydroxyapatite (HA) specimens with totals of 391 and 513 indentations per specimen. This study tests the validity of theoretical studies of microcrack damage-induced changes in E and υ, where the changes are expressed either by (i) the volumetric crack number density, N and (ii) the crack damage parameter, ε. All elasticity measurements were done via resonant ultrasound spectroscopy. For both the HA specimens included in the study and alumina specimens indented in an earlier study [J Mater Sci 38:1910. doi: , 1], E and υ decreased approximately linearly with increasing microcrack damage. The slopes of the E and υ versus N and ε are also computed and compared to the available theoretical models.     

Analysis of the ch-index: an indicator to evaluate the diffusion of scientific research output by citers

This paper focuses the attention on the ch-index, a recent bibliometric indicator similar to the Hirsch (h) index, to evaluate the published research output of a scientist (Ajiferuke and Wolfram, Proceedings of the 12th international conference of the international society for scientometrics and informetrics. Rio de Janeiro, pp. 798–808, 2009). Ch-index is defined as the number such that, for a general group of scientific publications, ch publications are cited by at least ch different citers while the other publications are cited by no more than ch different citers. The basic difference from the classical h is that, according to ch, the diffusion of one author’s publication is evaluated on the basis of the number of different citing authors (or citers), rather than the number of received citations. The goal of this work is to discuss the pros and cons of ch and identify its connection with h. A large sample of scientists in the Quality Engineering/Management field are analyzed so as to investigate the novel indicator’s characteristics. Then, the analysis is preliminarily extended to other scientific disciplines. The most important result is that ch is almost insensitive to self-citations and/or citations made by recurrent citers, and it can be profitably used for complementing h.     

C-K design theory: an advanced formulation

C-K theory is a unified Design theory and was first introduced in 2003 (Hatchuel and Weil 2003). The name “C-K theory” reflects the assumption that Design can be modelled as the interplay between two interdependent spaces with different structures and logics: the space of concepts (C) and the space of knowledge (K). Both pragmatic views of Design and existing Design theories define Design as a dynamic mapping process between required functions and selected structures. However, dynamic mapping is not sufficient to describe the generation of new objects and new knowledge which are distinctive features of Design. We show that C-K theory captures such generation and offers a rigorous definition of Design. This is illustrated with an example: the design of Magnesium-CO₂ engines for Mars explorations. Using C-K theory we also discuss Braha and Reich’s topological structures for design modelling (Braha and Reich 2003). We interpret this approach as special assumptions about the stability of objects in space K. Combining C-K theory and Braha and Reich’s models opens new areas for research about knowledge structures in Design theories. These findings confirm the analytical and interpretative power of C-K theory.

Stability analysis of undrained adiabatic shearing of a rock layer with Cosserat microstructure

Stability of undrained shearing in a classical Cauchy continuum has been first analyzed by Rice (J Geophys Res 80(11):1531–1536, 1975) who showed that instability occurs when the underlying drained deformation becomes unstable (i.e. in the softening regime of the corresponding drained stress-strain curve). However Vardoulakis (Int J Numer Anal Methods Geomech 9:339–414, 1985; Int J Numer Anal Methods Geomech 10:177–190, 1986) has shown that Rice’s linear stability analysis, if performed at the state of maximum deviator, leads to a sharp transition from infinitely stable to infinitely unstable behaviour, which indicates that the solution of the considered initial-value problem does not exist and consequently that the corresponding problem is mathematically ill-posed. Vardoulakis (Géotechnique 46(3):441–456, 1996; Géotechnique 46(3):457–472, 1996) proposed a regularization of the ill-posed problem in the softening regime by resorting to a second grade extension of plasticity theory. In this paper, the kinetics of a granular material is described by a Cosserat continuum as first suggested by Mühlhaus and Vardoulakis (Géotechnique 37:271–283, 1987) and we incorporate the effect of shear heating due to the dissipation of the frictional work. The undrained adiabatic limit is applicable as soon as the slip event is sufficiently rapid and the shear zone broad enough to effectively preclude heat or fluid transfer as it is the case during an earthquake or a landslide. It is shown that shear heating has a destabilizing effect and that instability can occur in the hardening regime if the amount of dilatant strengthening is not sufficient as compared to the effect of thermal pressurization of the pore fluid. It is shown that the linear stability analysis with macro and micro inertia terms leads to the selection of a preferred wave length of the instability mode corresponding to the instability mode with fastest (but finite) growth coefficient.     

Exploiting group symmetry in truss topology optimization

We consider semidefinite programming (SDP) formulations of certain truss topology optimization problems, where a lower bound is imposed on the fundamental frequency of vibration of the truss structure. These SDP formulations were introduced in Ohsaki et al. (Comp. Meth. Appl. Mech. Eng. 180:203–217, 1999). We show how one may automatically obtain symmetric designs, by eliminating the ‘redundant’ symmetry in the SDP problem formulation. This has the advantage that the original SDP problem is substantially reduced in size for trusses with large symmetry groups.     

The “Mendel syndrome” in science: durability of scientific literature and its effects on bibliometric analysis of individual scientists

The obsolescence and “durability” of scientific literature have been important elements of debate during many years, especially regarding the proper calculation of bibliometric indicators. The effects of “delayed recognition” on impact indicators have importance and are of interest not only to bibliometricians but also among research managers and scientists themselves. It has been suggested that the “Mendel syndrome” is a potential drawback when assessing individual researchers through impact measures. If publications from particular researchers need more time than “normal” to be properly acknowledged by their colleagues, the impact of these researchers may be underestimated with common citation windows. In this paper, we answer the question whether the bibliometric indicators for scientists can be significantly affected by the Mendel syndrome. Applying a methodology developed previously for the classification of papers according to their durability (Costas et al., J Am Soc Inf Sci Technol 61(8):1564–1581, 2010a; J Am Soc Inf Sci Technol 61(2):329–339, 2010b), the scientific production of 1,064 researchers working at the Spanish Council for Scientific Research (CSIC) in three different research areas has been analyzed. Cases of potential “Mendel syndrome” are rarely found among researchers and these cases do not significantly outperform the impact of researchers with a standard pattern of reception in their citations. The analysis of durability could be included as a parameter for the consideration of the citation windows used in the bibliometric analysis of individuals.     

A variational void coalescence model for ductile metals

We present a variational void coalescence model that includes all the essential ingredients of failure in ductile porous metals. The model is an extension of the variational void growth model by Weinberg et al. (Comput Mech 37:142–152, 2006). The extended model contains all the deformation phases in ductile porous materials, i.e. elastic deformation, plastic deformation including deviatoric and volumetric (void growth) plasticity followed by damage initiation and evolution due to void coalescence. Parametric studies have been performed to assess the model’s dependence on the different input parameters. The model is then validated against uniaxial loading experiments for different materials. We finally show the model’s ability to predict the damage mechanisms and fracture surface profile of a notched round bar under tension as observed in experiments.     

The discipline dependence of citation statistics

This study compares the citations characteristics of researchers in engineering disciplines with other major scientific disciplines, and investigates variations in citing patterns within subdisciplines in the field of engineering. Utilizing citations statistics including Hirsch’s (Proc Natl Acad Sci USA 102(46):16569–16572, 2005) h-index value, we find that significant differences in citing characteristics exist between engineering disciplines and other scientific fields. Our findings also reveal statistical differences in citing characteristics between subdisciplines found within the same engineering discipline.     

Citations among communication journals and other disciplines: a network analysis

This article describes the results of a network analysis based on the citation among Communication journals and those academic disciplines that are cited by those journals labeled as “Communication” by the Web of Science. The results indicate that the journals indexed solely as Communication rather than those also tagged as another social science are more central in the citation network. Further, a cluster analysis of the cited disciplines revealed three groupings, a micro psychological cluster, a macro socio-political group and a woman’s studies clique. A two-mode network analysis found that the most central Communication journals cited multiple clusters, while the peripheral journals cited only one, suggesting that the structure of influence on the field of Communication is more complex than suggested by Park and Leydesdorff (Scientometrics 81(1):157–175, 2009). Also, the results indicate that the macro cluster is about twice as influential as the micro cluster, rather than as Park and Leydesdorff suggest that Psychology is the discipline’s primary influence.     

Understanding the role of open peer review and dynamic academic articles

We welcome the commentary by L. Egghe (Scientometrics, this issue) stimulating discussion on our recent article “Natural selection of academic papers” (NSAP) (Scientometrics, 85(2):553–559, 2010) that focuses on an important modern issue at the heart of the scientific enterprise—the open and continuous evaluation and evolution of research. We are also grateful to the editor of Scientometrics for giving us the opportunity to respond to some of the arguments by L. Egghe that we believe are inaccurate or require further comment.