Search

Globally, more than 1 billion waste tyres are produced every year, and environmentally friendly end-of-life scenarios are highly sought after. Incineration to capture energy is a common practice. An improvement to sustainability is a cascaded use, where worn-out tyres are first being deployed in a meaningful way, e.g. as noise barriers or as embankment stabilization, where they can add value for several years to decades, before they are incinerated. The novel innovative use cases for tyres were found to offer advantages for the environment, while saving costs over materials that are being deployed today. This paper presents two recent innovations with waste tyres by a private inventor, and also highlights critical success factors for this type of innovator. Perseverance is one character trait a private inventor has to demonstrate in order to land a true innovation, focus a critical activity. Waste tyres can be considered an underutilized raw material. Keywords: Innovation; Private Inventor; Upcycling; Waste Management; Sustainability; Invention

Innovation is considered a key factor for companies operating in competitive markets. In consequence, the European Society for Engineering Education (SEFI) considers it as one of the crucial skills that newly graduated engineers should be educated on. It can be seen as a responsibility of universities’ staff to provide the needed knowledge, skills, and attitudes that would enable graduated engineers to identify the companies' needs to obtain effective innovations. To develop this last aspect, the University must allow students to have the opportunity to get acquainted with students from other countries working in the same innovation development project.In this paper, an experience is presented that analyses the collaboration among five university partners. Students of these institutions have collaborated in 8 innovation engineering projects that were carried out in the fall of 2019. In February 2020, a symposium was organized in Eindhoven, The Netherlands, where students showcased their innovations. In total, about 67 students from different nationalities collaborated in these 8 projects. This paper will cover the experiences of students and teachers in these international innovation engineering projects.

On the surface, the process landscape for fixed income securities trading within most banks has changed only slightly in the past four decades. The value chain remains divided amongst front-, middle-, and back office, with IT in support. Front office negotiates deals with customers and other banks, middle office manages risks and reporting, and back office ensures that payments are made in exchange for a transfer of the bonds that have been traded. Though these processes have gradually migrated to electronic mediums, much of the work in all functional areas remains manual. But the advent of digital technologies, primarily process automation software and data integration in an open software architecture, allows banks to dramatically change how the processes along the value chain are carried out. Repetitive and predictable tasks can be performed by automated software, allowing humans to concentrate on complex activities that require flexibility and discretion. Those tasks that remain in the hands of humans can also be made more efficient by extracting data from software applications along the entire process chain and providing them to the human user at the right point in time in the right system.

Conventional Fused Filament Fabrication (FFF) equipment can only deposit materials in a single direction, limiting the strength of printed products. Robotic 3D printing provides more degrees of freedom (DOF) to control the material deposition and has become a trend in additive manufacturing. However, there is little discussion on the strength effect of multi-DOF printing. This paper presents an efficient process framework for multi-axis 3D printing based on the robot to improve the strength. A multi-DOF continuous toolpath planning method is designed to promote the printed part’s strength and surface quality. We generate curve layers along the model surfaces and fill Fermat spiral in the layers. The method makes it possible to take full advantage of the multi-axis robot arm to achieve smooth printing on surfaces with high curvature and avoid the staircase effect and collision in the process. To further improve print quality, a control strategy is provided to synchronize the material extrusion and robot arm movement. Experiments show that the tensile strength increases by 22–167% compared with the conventional flat slicing method for curved-surface parts. The surface quality is improved by eliminating the staircase effect. The continuous toolpath planning also supports continuous fiber-reinforced printing without a cutting device. Finally, we compared with other multi-DOF printing, the application scenarios, and limitations are given.

Even though extensive research has been directed toward optimization of the strain, media, and the process, yet there is limited knowledge on the performance and viability of large-scale PHB produc...

There is an urgent need to assess European citizens’ perspective regarding their plastic consumption and to evaluate their awareness of the direct and indirect effect of plastics on human health in order to influence current behavior trends. In this study, the evaluation has been cross-related with scientific facts, with the final aim of detecting the most recommendable paths in increasing human awareness, reducing plastic consumption, and consequently impacting human health. A statistical analysis of quantitative data, gathered from 1000 European citizens via an online survey in the period from May to June 2020, showed that a general awareness about the direct impact of plastic consumption and contamination (waste) on human health is high in Europe. However, only a few participants (from a higher educational group) were aware of the indirect negative effects that oil extraction and industrial production of plastic can have on human health. This finding calls for improved availability of this information to general public. Despite the participants’ positive attitude toward active plastic reduction (61%), plastic consumption on a daily basis is still very high (86%). The most common current actions toward plastic reduction are plastic bag usage, reusage, or replacement with sustainable alternatives (e.g., textile bags) and selecting products with less plastic packaging. The participants showed important criticism toward the information available to the general public about plastics and health. This awareness is important since significant relation has been found between the available information and the participants’ decisions on the actions they might undertake to reduce plastic consumption. The study clearly showed the willingness of the participants to take action, but they also requested to be strongly supported with joint efforts from government, policies, and marketing, defining it as the most successful way toward implementing these changes.

Complex structures and a high level of customization in architecture and construction industries require the usage of industrial robots for milling or additive manufacturing applications. Due to economic aspects and the intensive research on robot machining, conventional machine tools are increasingly superseded for specific tasks by industrial robots. However, assembling errors during the manufacturing process and low structural stiffness of industrial robots are still main reasons for inaccuracies of robotic based machining. This paper presents a comparison between industrial robots and cnc machine tools and evaluates their strength and weaknesses. Furthermore, recently published works considering robot calibration and offline compensation strategies in order to increase the absolute and machining accuracy are presented. Finally, the adaption of an existing robot machining process chain with additional components underlines the potential of robots for machining tasks.

State-of-the-art 3D-printing with metal filaments based on the Fused Filament Fabrication (FFF) process is discussed in this paper, by a literature review and own printing tests. Commercially available metal filaments (composites with metal powder content) are flexible enough to be processed on a low budget 3D-printer and, by debinding and sintering the produced objects, it is possible to reach 80% and more of the mechanical strength of machined metal counterparts. A market research for available metal filaments from different sellers was conducted. The filament in question is compared by price and its printing and sintering properties, and particularities have been outlined. The prices for these metal filaments range from about €100/kg to €500/kg, with one exception: a filament which contains titanium is being offered for nearly €1500/kg. Objects have been successfully printed from a purchased, sinterable metal filament (“Ultrafuse® 316L” filament from BASF containing steel (DIN 1.4404, X 2 CrNiMo 17 13 2)) with the use of a low-budget 3D-printer to verify its feasibility. The testing model for printing was a “benchy”, which is a common test object in the hobby area of 3D-printing. Physical adjustments which had to be made to the printer itself and the printing parameters, as well as the difficulties faced while printing, are described in detail. This paper should serve hobbyist makers in doing the transition from plastics FFF to metal FFF to allow them to produce more durable parts.

Ceramic materials offer a variety of desirable material properties, but due to being particularly hard and brittle, are challenging to machine in subtractive processes. Additive manufacturing of ceramics parts requires costly machines and raw materials, limiting the use of additively produced ceramic parts to the professional realm. Fused Filament Fabrication (FFF) has become a widespread additive manufacturing technology, due to low cost of machines and materials (typically polylactic acid (PLA) and ABS)). This paper addresses the suitability of the FFF process to manufacture ceramics parts cost-effectively.

Since the last decade, the industry of 3D printing is sharply on the rise. A new trend in the manufacturing of polymers deals with the production of upscaled products that exceed an object size of one cubic meter. This trend has still some challenges to overcome that aim to reduce the costs and the process time in order to enable a more economical production. A method called Fused Granular Fabrication (FGF) uses thermoplastic pellets as a working material. FGF faces the challenges of upscaled 3D printing. Plastic pellets come to a friction of the cost of filament rolls for typical 3D printing application. Furthermore, they offer a greater variety of materials and can be refilled constantly during the printing process, which guarantees a production of almost unlimited big 3D prints. This paper deals with an industrial robot application of the UAS Technikum Wien that is equipped with a simple pellet extruder. The process parameters for good 3D prints were evaluated in a series of tests. All the tests were performed with Ingeo 4034D PLA pellets. A developed cooling system could speed up the process time by 17% for qualitative 3D prints. This work shows the potential of the FGF method and focuses on the build of an upscaled vase with a height of one meter. It was found out that the system still has an insufficient print speed for larger plastic objects, because of the slow feed rate of the used pellet extruder. As a result, a new research started for an alternative pellet extruder. Some of the potential extruders were good substitutes to produce upscaled 3D prints but they come to a high cost. As a self-made solution a new concept for a pellet extruder was designed. The introduced concept should achieve a material flowrate above 2 kg/h, to enable the 3D print of upscaled plastic products within a single day. As industrial robots are already an essential part of our modern industry 4.0, this technology allows it to easily produce individual products with existing systems. The designed pellet extruder can be mounted and exchanged smoothly to make the modern production more efficient.

In general, composite materials are difficult to recycle. Tires belong to this class of materials. On top, one of their main constitutents, vulcanized rubber, is as elastomer, which cannot be remolten and hence is particularly challenging to put to a new use. Today, the main end-of-life routes of tires and other rubber products are landfilling, incineration in e.g., cement plants, and grinding to a fine powder, generating huge quantities and indicating a lack of sustainable recycling of this valuable material. True feedstock recycling is not feasible for complex mixtures such as tires, but devulcanization can be done to reactivate the cross-linked polymer for material recycling in novel rubber products. Devulcanization, i.e., the breaking up of sulfur bonds by chemical, thermophysical, or biological means, is a promising route that has been investigated for more than 50 years. This review article presents an update on the state-of-the art in rubber devulcanization. The article addresses established devulcanization technologies and novel processes described in the scientific and patent literatures. On the one hand, tires have become high-tech products, where the simultaneous improvement of wet traction, rolling resistance, and abrasion resistance (the so-called “magic triangle”) is hard to achieve. On the other hand, recycling and sustainable end-of-life uses are becoming more and more important. It is expected that the public discussion of environmental impacts of thermoplastics will soon spill over to thermosets and elastomers. Therefore, the industry needs to develop and market solutions proactively. Every year, approximately 40 million tons of tires are discarded. Through the devulcanization of end-of-life tires (ELT), it is possible to produce new raw materials with good mechanical properties and a superior environmental footprint over virgin products. The devulcanization process has become an interesting technology that is able to support the circular economy concept.

Environmental surfaces and their role in the incidence of nosocomial infections are the most common causes that affect hospitalized patients. Several approaches have been developed in surface technology, which offer an opportunity for investigation of novel materials with antimicrobial activity to avoid colonization of harmful microorganisms on non-living surface. Inorganic materials such as metals and metal oxides represent increasingly important materials as antimicrobial agents for numerous biological, chemical, biomedical and pharmaceutical applications. In this study, the morphology effect of molybdenum trioxides on their antimicrobial activity is reported. Our empirical results show that the crystal structures of molybdenum oxides including orthorhombic, monoclinic and hexagonal polymorphs exhibit an excellent to good antimicrobial activity, respectively. The authors suggest that molybdenum oxides can prevent the growth of various harmful microorganisms because of their different crystals and might be also reason of their different specific surface areas. These materials can provide a long-lasting antibacterial effect and are ideal for inanimate surfaces, which can be used in public and healthcare environments.

A fiber-based remote measurement setup for tunable diode laser absorption spectroscopy, introducing an electrically pumped, micromechanical vertical-cavity surface-emitting laser with single-mode emission spectrum, narrow linewidth of 40 MHz, and broadband, continuous wavelength coverage of 51 nm around 1.55 mum is presented. The tunable laser spectrometer is employed for analysis of heterogeneous gas compositions and simultaneous detection of two species, ammonia and carbon monoxide, in a single continuous wavelength sweep. Broadband absorbance spectra are captured at elevated temperatures up to 300 degC revealing opposed temperature dependencies for selected transitions.

The carbon conversion of different solid fuels (i.e. beech wood, fir wood, bituminous coal) was investigated in the freeboard of a laboratory-scale fluidized bed combustor by in situ tunable diode laser absorption spectroscopy. A room temperature continuous wave InGaAsSb/AlGaAsSb quantum well ridge diode laser emitting at 2.3–2.35 μm was wavelength tuned at 300 Hz to determine simultaneously CH 4 and CO during devolatilization and char combustion in situ 10 mm above the fuel particles. The lower detection limit was 0.2 vol% (5000 ppm m) for both species. In addition, CO, CO 2 and O 2 were determined ex situ by conventional methods. The experimental results obtained for the bituminous coal were compared to a detailed chemical kinetic model. The in situ measurements proved to be advantageous compared to conventional ex situ concentration measurements. The calculations confirm the determination of the primary products of solid fuel combustion during devolatilization and char combustion. A rather simple model for the devolatilization products was proven to describe well the release rates of CH 4 and CO for the bituminous coal.

The laser-induced ignition of methane/air-mixtures at elevated pressures was investigated by an absorption spectroscopic technique. A room temperature continuous wave InGaAsSb/AlGaAsSb quantum well ridge diode laser was wavelength tuned around 2.55 μm by periodically modulating the injection current from 0 to 174 mA at a 5 kHz repetition rate. The laser heat sink temperature was fixed at 291 K. The infrared laser beam was sent through the pressurized combustion vessel perpendicularly to the igniting laser beam (Nd:YAG laser, 10 ns pulse duration, 20 mJ) at the position of the ignition spark. Fuel-rich to fuel-lean mixtures of methane/air (air equivalence ratio 0.89, 1.06, 1.42, 2.50) were investigated at initial pressures of up to 3 MPa. The initial temperature was 473 K, the volume of the combustion vessel 0.9×10−3 m3. The formation of water vapor in the vicinity of the laser spark was tracked by the diode laser. The time resolution of the measurements was 0.2 ms for a total continuous measurement time of up to 1 s. In this way, the laser-induced ignition and its accompanying effects could be investigated on a time scale spanning four orders of magnitude. Apart from the absorbance of water vapor which could be determined semi-quantitatively (due to the effects of severe pressure broadening at high pressures and the ignorance of the exact temperature distribution after ignition), the emissions from the flame (broadband, 1–10 μm) and a gas inhomogeneity index were recorded. The gas inhomogeneity index was obtained by extracting a frequency variable from the time-dependent fluctuations of the transmitted laser intensities and calculating its derivation. The absorbance of water vapor, the emissions from the flame and the gas inhomogeneity index were found to be a powerful tool to characterize laser-induced ignition. Major implications of in situ species concentration measurements at high pressures for the design and development of high-load combustors are presented.

Oberflächenemittierende Diodenlaser (engl. VCSEL, Vertical-cavity surface-emitting laser) werden zur raschen direkten In-situ-Molekülspektroskopie eingesetzt. Nach dem Verfahren der Absorptionsspektroskopie mittels durchstimmbarer Diodenlaser wird Sauerstoff bei 760 nm, Ammoniak bei 1540 nm, Methan bei 1680 nm sowie Chlorwasserstoff und Wasser bei 1810 nm detektiert. Druckverbreiterte und hochaufgelöste Spektren werden gezeigt und das Prinzip eines langzeitstabilen Spektrometers vorgestellt. Die Wellenlängenmodulation der VCSEL mit der Temperatur und dem Strom wird untersucht. Während der Temperaturkoeffizient in etwa derselbe ist wie für herkömmliche Diodenlaser im nahen Infrarot (DFB-Laser), lassen sich VCSEL deutlich weiter mit dem Strom durchstimmen. Darüber hinaus können VCSEL thermisch wesentlich schneller moduliert werden als konventionelle Kantenemitter. Repetitionsraten bis 5 MHz werden demonstriert. Die neu eröffneten Anwendungsfelder im Hinblick auf den weiten, modensprungfreien Durchstimmbereich (Messung bei hohem Druck, mehrere Spezies, Temperaturverteilungen) und die rasche Modulierbarkeit (Messung extrem transienter Prozesse) werden diskutiert. Weiter werden spektroskopisch interessante Eigentümlichkeiten der VCSEL (geringer Schwellstrom und Strombedarf als Vorteil für batteriebetriebene mobile Geräte, Austestmöglichkeit auf der Waferebene) beleuchtet. Die langwelligen VCSEL mit λ > 1 μm auf InP-Basis existieren noch nicht lange. Es wird angenommen, dass diese demnächst verstärkten Einzug in die Molekülspektroskopie halten werden und das Einsatzgebiet von auf Diodenlasern basierenden Geräten beträchtlich nach höheren Drücken und schwierigen Bedingungen hin erweitern werden.

A single-frequency VCSEL has been used for the first time for high-resolution spectroscopy near 1.5 μm. The incorporated buried-tunnel-junction technology enabled the realization of a long-wavelength InGaAlAs/InP VCSEL with low threshold current (0.925 mA), high output powers (0.576 mW) and low series resistance (60 Ω). The high-speed tuning capability of the long-wavelength VCSEL was investigated and used to conduct high-speed absorption spectroscopy. The peak tuning speed was measured to be 3.4 cm-1/μs and a 4.5-cm-1-wide NH3 spectrum was recorded in 2 μs. The VCSEL was used to measure highly resolved low-pressure spectra for pressures ranging from 9.6 mbar to 1 bar. The measured Doppler-broadened linewidth of 0.02 cm-1 agrees within 3% with the theoretical calculations. The availability and various advantages of 1.3–2-μm single-frequency VCSELs as compared to edge-emitting diode lasers, such as a large current tuning range even at very high tuning frequencies, and low production costs, should significantly expand the application fields for near-infrared laser gas sensors.

A 1.8 µm wavelength single frequency InGaAlAs–InP vertical-cavity surface-emitting laser (VCSEL) was used successfully for the first time for high resolution absorption spectroscopic measurements. As a demonstration of the multi-species measurement capability, spectra of HCl, CH4 and H2O gases were measured at pressures ranging from 0.07 to 1.5 bar and compared with calculations based on the HITRAN2000 database. In general, good agreement was observed. The laser threshold was 0.9 mA, the temperature tuning rate was 0.125 nm K−1 (0.38 cm−1 K−1) and the current tuning rate was 0.9 nm mA−1 (2.75 cm−1 mA−1). A continuous mode-hop-free single frequency current tuning range of 8.4 cm−1 (2.8 nm) was achieved using a 0–4.1 mA driving current. Single frequency VCSELs show a variety of advantages compared to edge emitting semiconductor lasers, such as wide current tuning range, very high tuning speeds (MHz) and therefore very good time resolution, little susceptibility to optical feedback and low manufacturing costs. The availability of long wavelength single frequency VCSELs (1.3–2 µm) should make VCSEL the preferred choice for diode-laser gas sensing and process control applications and help to significantly expand the application fields for infrared diode-laser gas sensors.

A GaAs-based quantum cascade laser was used to record the absorption spectrum of product gas from a biomass steam gasification plant. The quantum cascade laser, processed as distributed feedback laser, emitted single mode. Its emission wavelength was tuned from 886.76 to 889.16 cm −1 by sweeping the operation temperature of the laser from 185 to 225 K. The spectrum of the biomass steam gasification gas was compared to the measured spectra of C 2 H 4 and NH 3 that agree well with the HITRAN 2000 database. The biomass steam gasification gas was found to contain 2% of C 2 H 4 . NH 3 could not be detected.

An electrically pumped InP-based vertical-cavity surface-emitting laser (VCSEL) emitting at 1.685 µm (5935 cm−1) was used to probe rovibrational transitions of methane in the 2ν3 band at pressures ranging from 10 mbar to 1.3 bar. For the first time a long-wavelength VCSEL at 1.68 µm was used for the demonstration of high-speed gas sensing at repetition rates as high as 5 MHz. The observed tuning rate at 1 MHz was 5.2 cm−1 µs−1. The maximum continuous current tuning range was more than 16 cm−1 (4.5 nm), which is very useful for measurements in high-pressure environments. At 1 MHz the tuning range was as large as 2.6 cm−1, at 5 MHz it was still approximately 0.36 cm−1. The measured tuning rates of the VCSEL were −3.05 cm−1 mA−1 (+0.86 nm mA−1) and −0.40 cm−1 K−1 (+0.11 nm K−1). Survey spectra measured with the VCSEL were compared to calculations using the HITRAN2000 spectroscopic database and found to be in good agreement. A VCSEL was directly contacted on a section of its wafer to demonstrate 'on-chip' testing ability as opposed to edge-emitting lasers that have to be singularized and individually mounted prior to characterization for spectroscopic applications. It is expected that VCSELs will considerably expand the range of operation for diode lasers in rapid in situ species concentration measurements because of their ability of fast and far mode-hop free single longitudinal and transverse mode tuning properties.

Combustion is an important and ubiquitous process, which supplies 85% of the worldwide energy as heat and power. In this article, fundamentals of combustion science are briefly reviewed: aspects of combustion chemistry, heat transfer and common fuels in solid, liquid and gaseous state. Biomass and safety-related concerns are also covered. In the main section, combustion technology is explained: Common combustors such as boilers, power plants, reactors and engines are presented. Combustion synthesis for the production of advanced materials and a section on combustion-derived pollutants and how to mitigate their effects such as climate change conclude this article. Keywords: combustion; furance; fire; power; fuel

Laser ignition has been discussed widely as a potentially superior ignition source for technical appliances such as internal combustion engines. Ignition strongly affects overall combustion, and its early stages in particular have strong implications on subsequent pollutant formation, flame quenching, and extinction. Our research here is devoted to the experimental investigation of the early stages of laser-induced ignition of CH4/air mixtures up to high pressures. Tests were performed in a 0.9–l combustion cell with initial pressures of up to 25 bar with stoichiometric to fuel-lean mixtures using a 5-ns 50-mJ 1064-nm Nd:YAG laser. Laser-induced fluorescence (LIF) was used to obtain two dimensionally resolved images of the OH radical distribution after the ignition event. These images were used to produce an animation of laser ignition and early flame kernel development. Schlieren photography was used to investigate the laser-induced shock wave, hot core gas, and developing flame ball. We extend existing knowledge to high-pressure regimes relevant for internal combustion engines.

The design, technology and characteristics as well as sensing applications of micromachined long-wavelength (~1.55μm) tunable vertical-cavity surface-emitting lasers are reported. The laser combines an active optical component (so-called half-VCSEL) and an agile mechanical component (MEMS) in a hybrid assembly. Electrothermal actuation expands the enclosed air-gap and continuously shifts the cavity resonance towards longer wavelengths. A curved mirror membrane is deployed to solely excite the desired fundamental mode with high output power and high sidemode suppression. The comparatively high stiffness of the MEMS lifts its mechanical resonance frequency to values around 150 kHz as measured by laser Doppler vibrometry under electrostatic actuation and - at the same time - reduces its susceptibility to Brownian motion. Laser linewidths as narrow as 32MHz are demonstrated by using the self-heterodyning technique and the wavelength dependent linewidth variation is presented for the first time. After successful absorption spectroscopy experiments under steady laboratory conditions the tunable VCSEL is used for trace gas detection in a combustion process. Preliminary experimental results are shown and practically encountered problems are discussed.

Absorption spectroscopy of CO and CO2 at wavelengths around 1.55mum via an all fiber based remote measurement setup is presented as application where a singlemode MEMS-VCSEL can feature its broadband (51 nm) continuous tuning characteristics

HCCI (Homogeneous Charge Compression Ignition), laser-assisted HCCI and spark plug-assisted HCCI combustion was studied experimentally in a modified single cylinder truck-size Scania D12 engine equipped with a quartz liner and quartz piston crown for optical access. The aim of this study was to find out how and to what extent the spark, generated to influence or even trigger the onset of ignition, influences the auto-ignition process or whether primarily normal compressioninduced ignition remains prevailing. The beam of a Qswitched Nd:YAG laser (5 ns pulse duration, 25 mJ pulse energy) was focused into the centre of the cylinder to generate a plasma. For comparison, a conventional spark plug located centrally in the cylinder head was alternatively used to obtain sparks at a comparable location. No clear difference in the heat releases during combustion between the three different cases of ignition start could be seen for the fuel of 80/20 iso-octane/nheptane used. However, with optical diagnostic methods, namely PLIF (Planar Laser-Induced Fluorescence), Schlieren photography and chemiluminescence imaging, differences in the combustion process could be evaluated.

A laser-based system should be advantageous to a spark-plug based ignition system. Free choice of the ignition spot and precise timing constitute two major advantages. Multi point laser ignition could lead to higher efficiencies, and laser ignition as such is capable of igniting leaner mixtures than a spark plug, thereby decreasing thermal NOx and soot emissions. This paper is devoted to advances in optical diagnostics of laser ignition for future internal combustion engines. The focus of this paper is on diagnostics at high pressures, that is engine-like conditions. Laser ignition tests were performed with the fuels methane, hydrogen and biogas in static combustion cells with dimensions comparable to stationary engines. A Nd:YAG laser (5 ns pulse duration, wavelength 1064 nm, 1–20 mJ pulse energy) was used to ignite gaseous fuel/air mixtures at initial pressures of 1–3 MPa. Schlieren photography and laser-induced fluorescence (LIF) were used for optical diagnostics (flame kernel development, shock wave propagation). The lean burn characteristics were investigated. Schlieren photography was used to determine the velocity of the shock wave and to study the influence of the shock wave on temperature rise and energy loss. Using planar laser-induced fluorescence (PLIF), the spatial distribution of the combustion intermediates OH and formaldehyde were recorded. The temporally resolved imaging shows that the initial stages of the flame front evolution closely follows the turbulence and density fluctuations caused by the shock and pressure wave induced by the laser spark. In this paper, results from LIF spectroscopy and Schlieren photography are compared. Depending on the laser pulse energy and focus size, at later stages after the ignition the flame front propagation approaches the laminar burning regime and flame front speed decrease. Flame front break up at lean conditions indicates the limit of the ignitable mixture fraction when the speed due to spark-induced convection exceeds the flame propagation rate.

Laser-induced ignition of hydrocarbon/air mixtures was investigated using a tunable InGaAsSb/AlGaAsSb diode laser at 2.55 /spl mu/m. The three parameters resonant water absorbance, flame emissions and a special gas inhomogeneity index were combined to characterize ignition.

Integrated marketing communications (IMC) is an approach to increase sales of a product by concerted actions in various promotional channels that achieve synergy. IMC has been applied extensively to consumer products. This paper shows that IMC is a valuable tool for the commercialisation of intellectual property (IP), e.g., patents and know-how, in a business to business (B2B) setting, that is for the commercialisation of patents and other types of IP. The value of IP depends strongly in its perceived value or utility for the business-customer, which can be conveyed in an advantageous way bv IMC. Hence, this paper addresses a new strategy for the successful commercialisation of IP. Patent marketing can increase the value of a patent or patent portfolio can be significantly. The business case is the central building block for IMC of intellectual property (IP). An important aspect for inventors is to keep in mind that it is not the technical sophistication of their innovation which brings them success, but its market. Marketing is a key for IP commercialisation.

Optical access to combustion chambers via windows is desirable for combustion diagnostics as well as for laser ignition. By nature, combustion deposits can form on the inner surface of the light-transmitting window, leading to malfunction. We investigated whether a Nd:YAG ignition laser could cope with combustion-chamber deposits by means of ablation. In a 1.8-kW four-stroke internal combustion engine an optical window was installed to couple in the laser light. Ignition was carried out by a spark plug. Due to inherent high fuel and oil consumption, a deposit layer would form on the substrate within some tens of minutes. Elementary analysis showed carbonaceous as well as inorganic compounds gradually reducing light transmission. With cyclic 5-ns laser shots through the window, the pass-through stayed essentially free of deposits provided the energy fluence was around 10 mJ/mm2. Microanalysis showed evidence of the soundness of the principle. In addition, even single shots with a higher flux were enough to remove a relatively thick layer of deposits at once. Thus an optical window in an internal combustion engine can in principle be kept transmissive by the action of a compact solid-state laser.

The spectroscopic application of a new broadband microelectromechanical-system-tunable vertical cavity surface-emitting laser with single-mode coverage of 60 nm (245 cm−1) in a single, continuous sweep is described. The operation of the device is illustrated with high-resolution spectra of CO and CO2 over 110 cm−1 (27 nm) and 67 cm−1 (17 nm), respectively, with the CO band shown for high-pressure scans between 1 and 3 bars (0.1-0.3 MPa). The achieved tuning range opens up new opportunities for tunable diode laser absorption spectroscopy. The spectra were compared with HITRAN-derived model calculations. The benefits of a sensor based on this laser are greater speed, laser power, and tuning range.

With the buried tunnel junctions technology a breakthrough in the dynamic and stationary losing performance has been achieved for long-wavelength InP-based VCSELs making these lasers ideally suited for broadband communications and gas sensing applications.

This chapter focuses on computational fluid dynamics (CFD) modeling for gas explosions. Recent results obtained at both laboratory and industrial scales are reviewed. It is pointed out the central role of large eddy simulation (LES) as the most adequate tool for describing the inherently unsteady interplay of flame propagation, flow field, and geometry underlying explosion phenomena. Modeling, numerical, and computational issues yet to be afforded are discussed as relevant to realize fully the potential of explosion LES. Keywords: gas explosions; modeling; computational fluid dynamics; unsteady Reynolds-averaged Navier–Stokes approach; large eddy simulation