Continuous improvement planning through sustainability assessment of product-service systems

The paper presents a methodology for the integrated sustainability assessment of a product-service system lifecycle, with the purpose to support continuous improvement on the side both of the manufacturer and of the user. Its eight steps are an extension of ISO 14040 life cycle assessment and consider all three sustainability dimensions – economic, environmental and social – and a service perspective, using the service unit. A set of indicators for the three dimensions, aligned to the service unit concept, is proposed based on literature suggestions

QCD Event Generators

This report is a survey on QCD Event Generator issues of relevance for LEP 2. It contains four main sections: a summary of experience from LEP 1, extrapolations to LEP 2 energies, Monte Carlo descriptions and standardization issues.Comment: 84 pages, LaTeX2e, eps figures included in file using filecontents environments, gzipped, uuencoded, to appear in the proceedings of the LEP 2 Worksho

Search for Neutral Heavy Leptons Produced in Z Decays

Weak isosinglet Neutral Heavy Leptons ($\nu_m$) have been searched for using data collected by the DELPHI detector corresponding to $3.3\times 10^{6}$ hadronic~Z$^{0}$ decays at LEP1. Four separate searches have been performed, for short-lived $\nu_m$ production giving monojet or acollinear jet topologies, and for long-lived $\nu_m$ giving detectable secondary vertices or calorimeter clusters. No indication of the existence of these particles has been found, leading to an upper limit for the branching ratio $BR($Z$^0\rightarrow \nu_m \overline{\nu})$ of about $1.3\times10^{-6}$ at 95\% confidence level for $\nu_m$ masses between 3.5 and 50 GeV/$c^2$. Outside this range the limit weakens rapidly with the $\nu_m$ mass. %Special emphasis has been given to the search for monojet--like topologies. One event %has passed the selection, in agreement with the expectation from the reaction: %$e^+e^- \rightarrow\ell \bar\ell \nu\bar\nu$. The results are also interpreted in terms of limits for the single production of excited neutrinos

Investigation of the splitting of quark and gluon jets

The splitting processes in identified quark and gluon jets are investigated using longitudinal and transverse observables. The jets are selected from symmetric three-jet events measured in Z decays with the Delphi detector in 1991-1994. Gluon jets are identified using heavy quark anti-tagging. Scaling violations in identified gluon jets are observed for the first time. The scale energy dependence of the gluon fragmentation function is found to be about two times larger than for the corresponding quark jets, consistent with the QCD expectation TeX . The primary splitting of gluons and quarks into subjets agrees with fragmentation models and, for specific regions of the jet resolution TeX , with NLLA calculations. The maximum of the ratio of the primary subjet splittings in quark and gluon jets is TeX . Due to non-perturbative effects, the data are below the expectation at small TeX . The transition from the perturbative to the non-perturbative domain appears at smaller TeX for quark jets than for gluon jets. Combined with the observed behaviour of the higher rank splittings, this explains the relatively small multiplicity ratio between gluon and quark jets

Measurement of the Quark and Gluon Fragmentation Functions in Z0Z^0 Hadronic Decays

The fragmentation functions and multiplicities in $b\overline{b}$ and light quark events are compared. The measured transverse and longitudinal components of the fragmentation function allow the gluon fragmentation function to be evaluated

Search for Lepton Flavour Number violating Z0Z^0-Decays

A search for lepton flavour number violating $Z^0$ decays in the channels \begin{center} $Z^0\rightarrow \mu\tau$,\\ $Z^0\rightarrow e\tau$, \\ $Z^0\rightarrow e\mu$, \\ \end{center} using the DELPHI detector with data collected during the 1991--94 LEP runs, is described. No signal was found. Upper limits at 95\% confidence level for the respective branching fractions of $1.2\times 10^{-5}$, $2.2\times 10^{-5}$, and $0.25\times 10^{-5}$, were obtained

Search for neutral heavy leptons produced in ZZ decays

Weak isosinglet Neutral Heavy Leptons (νm) have been searched for using data collected by the DELPHI detector corresponding to 3.3 × 106 hadronic Z0 decays at LEP1. Four separate searches have been performed, for short-lived νm production giving monojet or acollinear jet topologies, and for long-lived νm giving detectable secondary vertices or calorimeter clusters. No indication of the existence of these particles has been found, leading to an upper limit for the branching ratio BR(Z0 → νmν̄) of about 1.3 × 10-6 at 95% confidence level for νm masses between 3.5 and 50 GeV/c2. Outside this range the limit weakens rapidly with the νm mass. The results are also interpreted in terms of limits for the single production of excited neutrinos. © Springer-Verlag 1997

Measurement of Trilinear Gauge Couplings in e+e−e^+ e^- Collisions at 161 GeV and 172 GeV

Trilinear gauge boson couplings are measured using data taken by DELPHI at 161~GeV and 172~GeV. Values for $WWV$ couplings ($V=Z, \gamma$) are determined from a study of the reactions \eeWW\ and \eeWev, using differential distributions from the $WW$ final state in which one $W$ decays hadronically and the other leptonically, and total cross-section data from other channels. Limits are also derived on neutral $ZV\gamma$ couplings from an analysis of the reaction \eegi

Life cycle based and triple bottom line assessment of sustainability impacts in product-service systems

Purpose Research suggests that Product-Service Systems and Sustainability are connected topics: by designing new business models based on the integration of products and services, new opportunities of decreasing sustainability burdens arise. Given this frame, a methodology for the triple bottom line assessment of impacts of a Product-Service System in its whole life cycle has been developed, with the purpose to enhance the integrated sustainability assessment of Product-Service Systems, and to overcome the limitations of current sustainability models in literature. Design/methodology/approach The methodology suggests an extension of the four procedural steps of ISO 14040 Life Cycle Assessment into an eight-step procedure which considers all three sustainability dimensions-economic, environmental and social-and a service perspective, through the use of the Service Unit concept, substituting the functional unit of Life Cycle Assessment. Moreover, a set of indicators for the three dimensions is proposed based on literature suggestions and developed with the Service Unit concept accordingly. Originality/value The methodology envisions a decision support for companies during New Product/Service Development, especially keeping into account four potential uses through the illustration of an industrial case study. The methodology can be adopted to evaluate a Product-Service System solution from both the sides of developer and user. The main value of the proposal is subsequent to the adoption of the Service Unit concept, in order to enable the integration of the three sustainability dimensions guided by completeness, consistency and avoidance of double counting of effects. Such a combination is also improving the existing integrations of economic-environmental dimensions, while providing a rationale for further development for what concerns the social dimension