Challenges in integrating requirements management with PLM

Nowadays, requirements management (RQM) is mostly not included in the current structures of product lifecycle management (PLM) systems, although RQM has become a critical activity throughout the PLM. Customer requirements with all related product information need not only be integrated with each other, but with all processes and stakeholders involved through the related business functions of product lifecycle. In this paper, we examine the various challenges of RQM, especially related to PLM. Company-specific challenges are identified, when integrating RQM with PLM in a case company acting in the automotive industry. The objective of this study is to find out how product-related information on customer requirements could better be utilised and integrated with PLM. We propose a new integration framework according to which the challenges at different integration levels are categorised. As a final conclusion, the study shows the core points where and how the concepts of PLM and RQM should be developed, as to create requirements integrated solutions for extended products and systems through the lifecycle.     

Effect of fuel injection pressure on a heavy-duty diesel engine nonvolatile particle emission

The effects of the fuel injection pressure on a heavy-duty diesel engine exhaust particle emissions were studied. Nonvolatile particle size distributions and gaseous emissions were measured at steady-state engine conditions while the fuel injection pressure was changed. An increase in the injection pressure resulted in an increase in the nonvolatile nucleation mode (core) emission at medium and at high loads. At low loads, the core was not detected. Simultaneously, a decrease in soot mode number concentration and size and an increase in the soot mode distribution width were detected at all loads. Interestingly, the emission of the core was independent of the soot mode concentration at load conditions below 50%. Depending on engine load conditions, growth of the geometric mean diameter of the core mode was also detected with increasing injection pressure. The core mode emission and also the size of the mode increased with increasing NOx emission while the soot mode size and emission decreased simultaneously.     

The effects of operating conditions on emissions from masonry heaters and sauna stoves

Emissions from masonry heaters and sauna stoves were studied. In the sauna stove the production of organic gaseous carbon (OGC) at 10 gC kg^?1 (per kilogram of fuel), carbon monoxide (CO) at 55 g kg^?1, fine particle mass (PM₁) at 5 g kg^?1 and number emissions (N) at 1.8 × 10¹⁵ kg^?1 was higher than in other measured appliances. In a modern technology masonry heater with a unique grate, the emissions were very low: 0.4 gC kg^?1 OGC, 14 g kg^?1 CO and 0.7 g kg^?1 PM₁. Conventional masonry heaters, using small logs, clearly produced higher emissions when compared to using large logs. Doubling the fuel load caused emission factors to increase by up to 4- times (OGC), except for the number emission, which decreased from 4.0 × 10¹⁴ to 2.0 × 10¹⁴ kg^?1. From the conventional masonry heater 90% of the PM was emitted during the firing phase. Its combustion process is different to that in stoves or conventional open fireplaces. The insufficient supply of air, due to too fast pyrolysis, and increased ash release, due to the high combustion temperature, are the main parameters which cause high particle and gas emissions in masonry heaters and sauna stoves.     

On-Line Characterization of Morphology and Water Adsorption on Fumed Silica Nanoparticles

The first wetting layer on solid nanoparticles has direct implications on the roles these particles play in industrial processes and technological applications as well as in the atmosphere. We present a technique for online measurements of the adsorption of the first few water layers onto insoluble aerosol nanoparticles. Atomized fumed silica nanoparticles were dispersed from aqueous suspension and their hygroscopic growth factors (HGF) and number of the adsorbed water layers at subsaturated conditions were measured using a nanometer hygroscopic tandem differential mobility analyzer (HTDMA). Particle morphology was characterized by electron microscopy and particle density was determined by mobility analysis. The HGFs of the size-selected particles at mobility diameters from 10 to 50 nm at 90% relative humidity (RH) varied from 1.05 to 1.24, corresponding to 2–6 layers of adsorbed water. The morphology of the generated fumed silica nanoparticles varied from spheres at 8–10 nm to agglomerates at larger diameters with effective density from 1.7 to 0.8 g/cm³ and fractal dimension of 2.6. The smallest spheres and agglomerates had the highest HGFs. The smallest particles with diameters of 8 and 10 nm adsorbed two to three water layers in subsaturated conditions, which agreed well with the Frenkel, Halsey, and Hill (FHH) isotherm fitting. In comparison to the small spheres or large agglomerates, the compact agglomerate structure containing a few primary particles increased the number of adsorbed water layers by a factor of ～1.5. This was probably caused by the capillary effect on the small cavities between the primary particles in the agglomerate.     

The ELPI Response and Data Reduction II: Properties of Kernels and Data Inversion

The first part of this article reports the analytical form of the Electrical Low Pressure Impactor (ELPI) kernel functions. In this latter part, the numerical quality of ELPI response matrices is studied and an example of an inversion algorithm is given. The ELPI assemblies with and without an electrical filter stage and with smooth or sintered impaction plates are studied and compared with basic impactor kernels and the kernels for the calculation of the aerosol mass distribution. It is shown that the ELPI assembly with the electrical filter stage and smooth impaction plates should be the best choice for the inversion of data if no bounce occurs. The comparison to a mass impactor shows that the devices are on par in data inversion. The inversion ELPI data is studied with a Bayesian algorithm assuming a bimodal lognormal size distribution of the aerosol. The algorithm includes a novel procedure for obtaining an initial guess of the distribution parameters. To our knowledge, it is also the first algorithm to use ELPI current readings as its input. Simulations and diesel emission measurements show that the proposed algorithm is a useful tool in the study of ELPI data.     

Nanoparticle Synthesis by Copper (II) Acetylacetonate Vapor Decomposition in the Presence of Oxygen

Crystalline nanometer-sized Cu 2 O and CuO particle formation was studied by vapor thermal decomposition of copper (II) acetylacetonate in a vertical laminar flow reactor at ambient pressure. Experiments were carried out at 3 furnace temperature profiles (maximum values of t furn = 432, 596, 705°C) and with 2 carrier gases (oxygen/nitrogen with mixture ratios of 0.5/99.5 and 10.0/90.0). The results of computational fluid dynamics simulations are presented. The introduction of oxygen into the system was found to increase the decomposition rate and removed impurities from particles. The size of produced primary particles varied from 10 to 200 nm. Particle crystallinity was found to depend on both the oxygen concentration and the furnace temperature. A model taking into account the detailed chemical reaction mechanisms during the particle formation is proposed. The model allows one to build a dynamic phase diagram of the condensed products formed during the decomposition and is in good agreement with the experimental results.     

Studies on steam condensation and particle diffusiophoresis in a heat exhanger tube

In this paper, studies on steam condensation and aerosol behaviour in a heat exchanger are presented. The heat exchanger is a model of one single tube of a Passive Containment Condenser (PCC) that is used in the European Simplified Boiling Water Reactor (ESBWR). A hot carrier gas containing nitrogen and steam with Ag and CsOH particles flows through the heat exchanger. The walls of the heat exchanger are cooled with a water jacket, thus causing steam condensation and diffusiophoretic particle deposition. The amount of condensed steam is measured, as well as the temperatures, particle mass concentrations and size distributions before and after the heat exchanger. The experiments are done with different proportions of steam and nitrogen in the carrier gas. Heat and mass transfer in the system are modelled with well known engineering correlations, producing results that agree nicely with the experimental results. The diffusiophoretic particle deposition velocity is shown to be proportional to the steam condensation rate, as expected.     

Electrostatic precipitator performance and trace element emissions from two Kraft recovery boilers

Fine particle emissions from combustion sources have gained attention recently due to their adverse effects on human health. The emission depends on the combustion process, fuel, and particulate removal technology. Particle concentrations at Kraft recovery boiler exits are very high, and the boilers are typically equipped with electrostatic precipitators (ESP). However, little data are available on the ESP performance in recovery boilers. Particle concentrations and size distributions were determined at two modern, operating recovery boilers. In addition, we determined the fractional collection efficiency of the ESPs by simultaneous measurements at the ESP inlet and outlet and the particulate emissions of trace metals. The particle mass concentration atthe ESP inlet was 11-24 g/Nm3 at the two boilers. Particle emissions were 30-40 mg/ Nm3 at boiler A and 12-15 mg/Nm3 at boiler B. The particle size distributions had a major particle mode at around 1 microm. These fume particles contained most of the particle mass. The main components in the particles were sodium and sulfate with minor amounts of chloride, potassium, and presumably some carbonate. The ESP collection efficiency was 99.6-99.8% at boiler A and 99.9% at boiler B. The particle penetration through the ESP was below 0.6% in the entire fume particle size range of 0.3-3 microm. Trace element emissions from both boilers were well below the limit values set by EU directive for waste incineration.     

Organising for infrastructure development programmes: Governing internal logic multiplicity across organisational spaces

Programme organisations operate in complex environments under the influence of multiple institutional logics. Previous studies have focused on how these kinds of organisations respond to external demands by implementing appropriate governance structures. This, however, produces an understanding of programme organisations as being unitary and working to integrate programme activities and practices under one dominant internal institutional logic. In this paper, we study the consequences of internal logic multiplicity for the governance of programme organisations. Drawing on data from a major Danish construction programme we show how, in order to achieve its mission, the programme organisation incorporates three distinct logics into its daily activities and practices. The findings illustrate how a compartmentalised structural approach is applied to differentiate and independently deal with the three logics in structurally distinct organisational spaces. To avoid fragmentation and ensure coordination, governance mechanisms are put in place that coordinate activities and practices across the organisational spaces whilst maintaining their compartmentalisation. The paper thus contributes to the literature on programme management with insights on how the institutional context influences programme structures and operations, and how governance mechanisms are implemented to manage activities and practices across organisational spaces guided by different logics.     

The effect of positive feedback on industrial housekeeping and accidents; A long-term study at a shipyard

The experiments aimed to determine the effects of performance feedback on housekeeping behavior and consequently, on injuries over a longer period of time, and also to assess the validity of well-known Heinrich's axioms with respect to accident causation. The study was conducted at two production halls of a shipyard. Nine performance targets were set for housekeeping performance. An observation method was developed to measure performance. After we determined the baseline, feedback on performance was given by posting the results of each observation round as a large graph on the wall. The housekeeping index was significantly improved in both halls after the feedback was started. The effect persisted throughout the two-year follow-up period. Accidents were reduced by 70–90%, much more than expected merely on the basis of improved housekeeping. The effect of feedback on accidents persisted for the three-year follow-up period. The possible mechanisms are discussed.