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Our regional burns service has gained experience in managing paediatric hand friction burns due to vacuum cleaners (VC). We aimed to evaluate our 10 year experience managing these injuries as well as reviewing national data trends in order to identify those at risk of injury. Materials and Methods A International Burns Injury Database (IBID) request was made to review the number of burn injuries recorded due to Vacuum cleaner injuries (VCIs). In addition, a local IBID request was made to identify the number of burn injuries managed within our regional burns service. Results We identified 288 VCIs which have increasingly occurred in England and Wales between 1996–2020 and 32 children who sustained these injuries within our regional burns service. A general theme from both national and local data highlighted that these injuries occurred in males (78%, n=25) with a mean age of 20 months (9 months–4.5 years) affecting children’s hands (94%). In 25 cases (78%) these injuries involved an interphalangeal joint. 85% (n = 27) of injuries were deep dermal/full thickness with eleven children (34%) undergoing surgical excision and skin grafts. Discussion Significant paediatric burn injuries can be sustained from VCs. Greater awareness is indicated for these injuries and legislation should be considered in order to improve the safety of vacuum cleaners. International burn societies are urged to collect data of these injuries in order to co-ordinate improved prevention strategies and change within the VC industry.

Background: The initial aim was to study the effects of face masks worn by recently infected individuals on the airborne spread of SARS-CoV-2, but findings motivated us to proceed with comparing the presence of SARS-CoV-2 in air samples near infected individuals at home with those near infected intensive care unit (ICU) patients. Aim: To assess the presence of SARS-CoV-2 in the air of homes of infected individuals and in ICU rooms of critically ill patients with COVID-19 who were undergoing different forms of potential aerosol-generating medical procedures. Methods: A high-volume air sampler method was developed that used a household vacuum cleaner with surgical face masks serving as sample filters. SARS-CoV-2 RNA was harvested from these filters and analysed by polymerase chain reaction. Fog experiments were performed to visualize the airflow around the air sampler. Air samples were acquired in close proximity of infected individuals, with or without wearing face masks, in their homes. Environmental air samples remote from these infected individuals were also obtained, plus samples near patients in the ICU undergoing potential aerosol-generating medical procedures. Findings: Wearing a face mask resulted in a delayed and reduced flow of the fog into the air sampler. Face masks worn by infected individuals were found to contain SARS-CoV-2 RNA in 71% of cases. SARS-CoV-2 was detected in air samples regardless of mask experiments. The proportion of positive air samples was higher in the homes (29/41; 70.7%) than in the ICU (4/17; 23.5%) (P < 0.01). Conclusion: SARS-CoV-2 RNA could be detected in air samples by using a vacuum cleaner based air sampler method. Air samples in the home environment of recently infected individuals contained SARS-CoV-2 RNA nearly three times more frequently by comparison with those obtained in ICU rooms during potential aerosol-generating medical procedures.

In the current hectic schedule, cleaning houses and surrounding environment is more arduous. At present, there are vacuum cleaners which require humans to handle it. Thus, there is a dire need to implement vacuum cleaner which works without human intervention. An efficient method to clean the desired area has been implemented through this project. By using this vacuum cleaner, hazardous places can be cleaned which thereby reduce risks to mankind. This is achieved by implementing an autonomous system. Here, RC car which is embedded with a vacuum cleaner is used. This system has an ultrasonic sensor attached to it, that helps in avoiding large obstacles such as tables, chairs, walls etc. By measuring the distance via this sensor, the car takes the direction where the distance between obstacle and car is more, hence avoiding the collision with the obstacles. The vacuum cleaner is designed with a CPU fan and a pipe is attached to the mouth of the bottle. The entire system is run by batteries.

In a globally connected business environment, a variety of stakeholders, aside from the owner of smart products, aim to operate and extract information from the smart product through smart services. The smart services are generated through aggregation of data to operations and information and recombination of these entities. Smart services offer a great potential to enrich the functionalities of smart products. In this paper we propose a novel design methodology to incorporate not only the resources of manufacturers of smart products but also a multitude of interested stakeholder using a robotic vacuum cleaner.

Natural draft chimneys are the traditional chimneys, which are being the most used because of its low cost and simple design compared to solar and other smart chimneys. However, the use of traditional chimneys reported the problem of back drafting particularly in colder regions. Utilization of various suction devices such as exhaust fan, vacuum cleaner and dryers lead to the development of negative pressure inside the house, which in turn causes possibilities of back drafting in chimneys. This allows the outside air to get into the house and affects the entire ventilation system. Stack effect of dwellings and other environmental factors such as seasonal temperature and pressure changes are the influential factors for back drafting along with the furnace on and off conditions. A numerical analysis of the flow of motion in the chimney was performed to visualize its behavior under all conditions including back drafting. CFD simulation results shown that the inside pressure gradient and temperature gradient of chimney determine the direction of hot dry air gases because of the variation in density of gas with respect to temperature change. The numerical study can be used to modify the design of vertical chimney duct such that flow can get only accelerated on moving towards the top of the chimney.

Modern households are becoming more automated thereby delivering convenience and reducing time spent on house chores. While vacuum cleaners have made home cleaning easier, they are largely noisy and bulky for everyday use. It is therefore sine qua non to improve the technology of vacuum cleaning to reduce these deficiencies. Here, we report the development of a compact and efficient vacuum cleaner robot for potential office and home use. The developed robot is disk-shaped, equipped with vacuuming and cleaning technology and controlled by Arduino mega microcontroller. It sucks dirt via a retractable dustbin on top of which a cooling fan is mounted, and two sweepers each driven by a 3 V DC motor. The robot navigates via two motor shield controlled rear wheels and a front caster wheel which also governs its turning. Four ultrasonic sensors, placed at 90° apart, detect obstacles and subsequently help the robot navigate. The robot is powered by 3 batteries (28.8 V DC), rechargeable via an embedded AC-DC adapter. It is 12 cm wide and 9 cm tall making it easy for maneuvering its environment. Because of the light weight battery, cardboard based dustbin and small blower used, its weight is about 1.5 kg. The total current consumed is ∼1102 mA. When fully charged, a 2200 mAh-capacity battery works continuously for two hours and cleans floor efficiently. With this capability, the device will be deployed for office and home use thereby making cleaning a fully autonomous duty. Keywords: Vacuum cleaner, Robot, Control

Centrifugal fans have several technical applications. Their aerodynamic performance is well-optimized nowadays, but the same does not apply to their acoustic performance. Noise control studies of centrifugal fans are often focused on designed operating conditions or operating conditions close to the onset of instability. This paper seeks to find an alternative geometry of the centrifugal fan impeller which would improve noise control of centrifugal fans in a wide range of operating conditions. In this paper, the term noise control refers to noise level reduction and additionally to manipulating the psychoacoustic properties of noise. The experimental work and numerical calculations focus on the centrifugal fan in vacuum cleaners. The experimental work, based on numerical simulations, is described to investigate the influence of the triangular cross section on the flow channel, formed by two inclined blades in opposite directions, on aerodynamic properties and the psychoacoustic performance of the impeller. The study demonstrates that impellers with a triangular flow channel achieve an aerodynamic performance which is comparable to that of standard impellers. The results also show that impellers with inclined blades deliver superior results in psychoacoustic metrics compared to impellers with upright blades.

Many governments have instructed the population to wear simple mouth-and-nose covers or surgical face masks to protect themselves from droplet infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in public. However, the basic protection mechanisms and benefits of these masks remain controversial. Therefore, the aim of this work is to show from a fluid physics point of view under which circumstances these masks can protect against droplet infection. First of all, we show that the masks protect people in the surrounding area quite well, since the flow resistance of the face masks effectively prevents the spread of exhaled air, e.g. when breathing, speaking, singing, coughing and sneezing. Secondly, we provide visual evidence that typical household materials used by the population to make masks do not provide highly efficient protection against respirable particles and droplets with a diameter of 0.3–2 μm as they pass through the materials largely unfiltered. According to our tests, only vacuum cleaner bags with fine dust filters show a comparable or even better filtering effect than commercial particle filtering FFP2/N95/KN95 half masks. Thirdly, we show that even simple mouth-and-nose covers made of good filter material cannot reliably protect against droplet infection in contaminated ambient air, since most of the air flows through gaps at the edge of the masks. Only a close-fitting, particle-filtering respirator offers good self-protection against droplet infection. Nevertheless, wearing simple homemade or surgical face masks in public is highly recommended if no particle filtrating respiratory mask is available. Firstly, because they protect against habitual contact of the face with the hands and thus serve as self-protection against contact infection. Secondly, because the flow resistance of the masks ensures that the air remains close to the head when breathing, speaking, singing, coughing and sneezing, thus protecting other people if they have sufficient distance from each other. However, if the distance rules cannot be observed and the risk of inhalation-based infection becomes high because many people in the vicinity are infectious and the air exchange rate is small, improved filtration efficiency masks are needed, to take full advantage of the three fundamental protective mechanisms these masks provide., Highlights • A simple mouth-and-nose cover or a surgical mask is able to effectively limit the spread of air and aerosol. • Wearing a mask is very useful to contain a pandemic by protecting people in the vicinity from droplet infection. • A mouth-and-nose cover or a surgical mask does not fit tightly enough on the face to protect against droplet infection. • Only a particle-filtering half-mask that fits tightly offers protection against droplet infection. • Common household materials, however, do not have a sufficient filter effect to protect against droplet infection.

Inhalation exposure to the resuspended biological particles from public places can cause adverse effects on human health. In this work, carpet dust samples were first collected from twenty example conference and hotel rooms by a vacuum cleaner. A bipedal robot was then used to simulate children's walking with three different shoes (cotton socks, PVC shoes and EVA shoes) in a hotel room. The particle resuspensions were simultaneously monitored by an aerosol spectrometer. In addition, air samples were also taken using a cyclone liquid impinger operated at 400 L min−1, and further subjected to gene sequencing analysis. Our results showed that dominant bacterial genera in the carpet dusts included those containing respiratory pathogens such as Staphylococcus, Acinetobacter and Pseudomonas. The bacterial structures in carpet dusts were shown different among the samples from hotel and conference rooms (p

Robotics technology has been constantly developing during the past two decades. Over recent years, several researches have been conducted to develop climbing robots to eliminate humans from laborious and dangerous tasks. Cleaning of walls of tall buildings is one of the applications of the climbing robot. The wall cleaning robot proposed in this paper consists of base module and cleaning module. We are using an electric ducted fan (EDF) and support ropes from base module placed on the parapet for adhering the cleaning module to the glass wall. This robot is designed in such a way that the cleaning module alone can also be used to clean the floor in which the EDF acts as a vacuum cleaner along with a vacuum pump to spray the cleaning fluid. Hence both dry and wet cleaning of floor can be done. The floor cleaning system is manually controlled using bluetooth signal from a smart phone, while wall cleaning is carried out automatically using sensors.

The development of efficient blowers for battery-operated vacuum cleaners is exploited to increase the portability of high resolution DMAs. A Halfmini DMA run by the blower of the iRobot Roomba 500 powered by a variable DC voltage is tested with electrosprayed molecular ions and the serum albumin protein. Sheath gas flow rates Q from 13 L/min up to 200 L/min are controlled, consuming from 0.28 to 12.5 W of electrical power. A pack of 6 Li batteries with 3.4 Ah charge capacity would run the DMA blower at 200 L/min for 6.5 h. The tetraheptylammonium ion monomer peak was completely resolved from the dimer ion even at Q=13 L/min, when it was classified at 10 V.

Integrating product design with appropriate end-of-life (EoL) processing is widely recognized to have huge potentials in improving resource recovery from electronic products. In this study, we investigate both the product characteristics and EoL processing of robotic vacuum cleaner (RVC), as a case of emerging electronic product, in order to understand the recovery fate of different materials and its linkage to product design. Ten different brands of RVC were dismantled and their material composition and design profiles were studied. Another 125 RVCs (349 kg) were used for an experimental trial at a conventional ‘shred-and-separate’ type preprocessing plant in Denmark. A detailed material flow analysis was performed throughout the recycling chain. The results show a mismatch between product design and EoL processing, and the lack of practical implementation of ‘Design for EoL’ thinking. In the best-case scenario, only 47% of the total materials in RVCs are ultimately recycled. While this low material recovery is mainly due to the lower plastic recycling rate, other market realities and the complex material flows in the recycling chain also contribute to it. The study provides a robust methodological approach for assessing the EoL performance based on the knowledge of a product and its complex recycling chain. The lessons learned can be used to support both the design and EoL processing of products with similar features, which carry a high potential for resource recovery, especially at the initial stage of the recycling chain. Integrating product design with appropriate end-of-life (EoL) processing is widely recognized to have huge potentials in improving resource recovery from electronic products. In this study, we investigate both the product characteristics and EoL processing of robotic vacuum cleaner (RVC), as a case of emerging electronic product, in order to understand the recovery fate of different materials and its linkage to product design. Ten different brands of RVC were dismantled and their material composition and design profiles were studied. Another 125 RVCs (349 kg) were used for an experimental trial at a conventional ‘shred-and-separate’ type preprocessing plant in Denmark. A detailed material flow analysis was performed throughout the recycling chain. The results show a mismatch between product design and EoL processing, and the lack of practical implementation of ‘Design for EoL’ thinking. In the best-case scenario, only 47% of the total materials in RVCs are ultimately recycled. While this low material recovery is mainly due to the lower plastic recycling rate, other market realities and the complex material flows in the recycling chain also contribute to it. The study provides a robust methodological approach for assessing the EoL performance based on the knowledge of a product and its complex recycling chain. The lessons learned can be used to support both the design and EoL processing of products with similar features, which carry a high potential for resource recovery, especially at the initial stage of the recycling chain.

This study investigated muscle activity and discomfort of the upper limb as a function of weight distributions in a handle of a cordless stick-type vacuum cleaner. Seventeen female college students with the experience of vacuum cleaner-use were recruited for testing. Handle mock-ups with five different centers of mass (top front, top rear, bottom front, bottom rear, and center) were manufactured, and muscle activity (electromyography) and discomfort (Borg CR10) were measured during vacuuming with the mock-ups. The results showed that the %MVC of the Extensor Carpi Ulnaris (p = 0.0155) and Upper Trapezius (p = 0.0228) decreased when the center of mass moved from the bottom to top of the mock-up. However, the %MVC of the Biceps Brachii had reverse propensities under the same conditions (p = 0.0151). Meanwhile, the discomfort on the hand (p = 0.0080), upper arm (p = 0.0160), shoulder (p = 0.0112), and neck (p = 0.0226) decreased when the center of mass moved from the bottom to top of the mock-up.

The present study was conducted to examine the concentrations, profiles, and mass distributions of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs), and polybrominated dibenzo-p-dioxins/furans (PBDD/Fs) based on the particle sizes of house dust samples from five homes in Japan. After removal of impurities from house dust from vacuum cleaner bags, selected indoor dust samples were size fractionated (>2 mm, 1–2 mm, 0.5–1 mm, 250–500 μm, 106–250 μm, 53–106 μm, and 250 μm in size and fluffy dust were included. The conclusion is that particulate dust

The vacuum cleaner robot should have a mechanism such as the artificial intelligence to solve the problem of cleaning the entire environment areas taking into account some factors such as the number of turns and the length of the trajectory. This robot’s mechanism or task is known as the path planning of coverage region (PPCR). In this paper, to resolve the problem of PPCR in a room environment, we propose an evolutionary approach. The latter is based on Genetic Algorithms (GA) which, consist of several steps to get the solutions. Each gene represents the robot position and some of chromosomes represent also the mini-path. In addition, this algorithm helps the robot to pass through every part of the environment by avoiding obstacles using different sensors. The results of simulation and comparison studies demonstrate the effectiveness and efficiency of the proposed approach.

It is shown that dust content of urban environment affects the morbidity rate. The study of dispersive soil (loessial and clay rocks) dust emission has been undertaken, 60% of such kind of soil are involved in earthworks in the Nizhnee Povolzhie region. It has been revealed that the nature of dust emission in the development of dispersive solid depends on the physical and mechanical properties (moisture, porosity, plasticity indices) and the depth of development. Dust emissions are allocated in the depth zone. The relationship between dust emission in loessial rocks and the composition of the underlying stratum deposits has been noted. If the loessial stratum covers the clay soil, during the development it leads to a smaller release of dust than when bedding on sandy rocks. Clay development is characterized by low dust emission figures; they depend on the variability of properties at different depth. It has been found that properties of rocks in the walls of borrows and grooves change over time. We have described the working principle and the main constituent elements of industrial vacuum cleaner, which is recommended to be used for cleaning pollutants that have accumulated after the construction work, during the development of dispersive soil, on city streets, in dead zones of joints of horizontal and vertical planes.

The first Oregon case of New Delhi metallo-β-lactamase-1 (NDM-1)-producing Escherichia coli was reported during November 2013. Epidemiologic investigation revealed only local outpatient medical care and no travel outside Oregon for both the patient and his household contact. Environmental sampling discovered a matching isolate from the patient’s household vacuum cleaner, suggesting environmental persistence.

Phthalate esters (PAEs) are widely used as household and industrial products in residential apartments. Sixteen PAEs in the settled dust from five surfaces in 17 residential apartments in Xi'an, China were investigated from February 2019 to August 2019. A hairbrush and vacuum cleaner were used to collect the dust samples. Four PAEs, namely dimethyl phthalate, diisobutyl phthalate, dibutyl phthalate, and bis (2-ethylhexyl) phthalate (DEHP), were detected in the dust. DEHP was the most predominant compound in the settled dust (median value of 965.1 μg/g). The total PAEs concentrations in the settled dust on the five different indoor surfaces were significantly different. The highest concentration was found for dust samples on equipment surfaces where dust can easily deposit (median value of 3442.5 μg/g), which was nearly 3 times higher than that from infrequently swept surfaces (median value of 1297.0 μg/g). The PAE concentration in dust from the frequently swept surfaces (median value of 2299.8 μg/g) was significantly higher than that from the infrequently swept surfaces. The composition profile of PAEs in dust from the five surfaces was completely different. Therefore, settled dust on different surfaces should be distinguished when conducting field investigations. In addition, increased concentrations with increasing temperature were found for dust from the infrequently swept surfaces, thereby suggesting that temperature may influence the phthalate concentrations in dust.

An eco-friendly process for recycling obsolete PCBs to get enriched rare-metal concentrate using physical separation technique is discussed. Metal concentration in digital video disc (DVD) PCBs is ∼43 wt.% whereas in vacuum cleaner (VC) PCBs ∼30 wt.% with rare metal of ∼ 2.8%. Concentrate grade of ∼88% total metals including ∼5.85% rare metals in-case of DVD-PCBs while ∼90% of total metals including ∼2.81% rare metals in-case of VC-PCBs was achieved by froth flotation. While ∼75% total metals including ∼9.41% rare metals for DVD-PCBs and ∼65% total metals including ∼5.10% rare metals for VC-PCBs was obtained by pneumatic separation.

Cyber-Physical-Social Systems integrate various resources from physical network, cyberspace, and social world.These systems rely on communication, computation and control infrastructures commonly consisting of several levels for the three worlds with various resources as sensors, actuators, computational resources, services, humans, etc. Efficient interaction of these resources is essential for cyber-physical-social systems operation. The paper presents multi-level self-organization approach for cyber-physical-social systems that distinguishes three main level for the system resource interaction: physical level, planning level, and strategic level. Smart home cleaning scenariois proposedas an example of multi-level self-organization approach. Robot vacuum cleaner creates room map using the light-sensitive sensors and clean room using the map. For the efficient cleaning, it requires the lights switch on in the cleaning room. For this purposes the vacuum cleaner has to interact with the adaptive illumination control system.Manipulating robot move light furniture (e.g. chairs, or coffee table) or decorative elements (pots with flowers, vases, etc.). It interacts with the vacuum cleaner for synchronization of moving light furniture.For the strategic level, a special strategic planning service has been identified that determines general strategy of resources behavior in the scenario based on interaction with personal mobile device and current situation in smart home. Example of general strategies can be for example reduction in energy consumption, excellent cleaning. For the planning level, a special room management services have been proposed that provide general behavior the cyber-physical-social systems resources in physical level. Example of these strategies can be clean room 1 completely, after that clean room 2 or vice versa. For the physical level a vacuum cleaner, manipulating, and light control services have been proposed. The paper present ontology-based information model for smart home devices interaction. It allows the services of physical level linked to the appropriate smart room devices interact in cyber space while physical devices interact in physical space. Every resource in physical level of cyber-physical-social system is described by the ontology. Appropriate ontologies of vacuumcleanerrobot, adaptive illumination control system, and manipulating robothave been proposed in the paper.

Perfluorooctanoic acid (PFOA) has long been an environmental contaminant of concern owing to its potential health risk. However, exposure to perfluorinated carboxylic acids (PFCAs) other than PFOA is not well understood. In this study, we investigated the concentrations of PFCAs in vacuum cleaner dust in Japan to measure the PFCAs contamination in an indoor environment. Most of the 77 samples contained PFCAs with 6-13 carbon atoms. The median concentration of perfluorononanoic acid (PFNA, 23.2 ng g(-1)) was highest among PFCAs, followed by PFOA (20.8 ng g(-1)) and perfluoroundecanoic acid (PFUnDA, 12.9 ng g(-1)). The 90th percentile concentrations of PFNA, PFUnDA and perfluorotridecanoic acid (PFTrDA) were 948, 283 and 110 ng g(-1), respectively, and these were detected at greater concentrations than neighboring, even-numbered PFCAs. The proportion of long-chain PFCAs in vacuum cleaner dust from Japan was relatively higher than those reported for other countries. Factor analysis showed three independent factors. Odd-numbered long chain PFCAs (PFNA, PFUnDA and PFTrDA), which can correspond to factor 1, were major components of PFCAs in vacuum cleaner dust. Short chain PFCAs (factor 2) and even numbered long chain PFCAs (factor 3) were also statistically separated. These findings suggest that there are several sources of PFCAs with different origins in indoor environment. Further investigations into the origins of PFCAs are needed to evaluate indoor contamination with PFCAs.

In order to compensate for the weaknesses of existing environmental product assessment tools, this paper proposes a new model developed by integrating the most salient features of the existing tools. This integrated model is intended for electrical and electronics products regulated under the European Directives WEEE, RoHS and EuP. This paper briefly describes the weaknesses of the existing environmental product assessment tools and the framework of the integrated model. Since the use of raw materials comes in the first stage in the product life cycle, the integrated environmental product assessment model described in this paper focused on the use of raw material stage. A vacuum cleaner was used to demonstrate the main concepts involved in using the integrated model to assess the environmental performance of the product.

In this paper we present a system for fault detection and isolation of electrical motors for vacuum cleaners, which serves for on-line quality assessment at the end of the production line. The main focus of the paper is on detection of incipient mechanical faults by means of sound analysis. A detailed description of the procedures for detection and isolation of faults with mechanical origin is given. One of the contributions concerns innovative implementation of the feature extraction algorithm in a way that spectral procedures used in system analysis are substituted by much simpler and computationally more effective algorithms. Herewith the system is able to accurately isolate three different types of mechanical faults. Additional contribution regards diagnostic system integration which generates highest product end quality and traceability. In order to fully utilize a huge amount of diagnostic data, possibilities for the upgrade of the present diagnostic system with advanced production line supervision support are indicated.

Noise emitted by a vacuum cleaner suction unit consists of airborne and structure-borne noise. The airborne noise is generated mainly by the turbo blower and the structure-borne noise is generated mainly by the driving electric motor. The structure-borne noise depends on the suction unit design and on operating conditions, and is especially distinct at partial flow rates when rotating stall and surge appear. Among geometrical parameters, the stator of the blower and the electric motor, or metal shield if any, have the greatest effect on the structure-borne noise. Therefore, in this part of the paper, the effects of vibrations of the electric motor structure on the noise characteristics have been measured and analysed at the design and off-design operation. The contribution of structure-borne sound to the total sound pressure level becomes relatively less important at higher flow rates and with a vaned diffuser built-in the blower.

Among all household appliances, the vacuum cleaner is the most powerful source of noise. The built-in suction unit, consisting of an electric motor and a centrifugal blower, represents the main source of noise; this is partially aerodynamic, mechanical and electromagnetic in origin. The contribution of the particular origin of noise generation to the total noise level depends on the geometry of the suction unit and operating conditions. The aerodynamically generated noise within the blower mostly prevails in the total emitted noise at design and off-design operations, and is especially distinct at partial flow rates when rotating stall and surge appear. The vaned diffuser built into the blower has an important effect on the emitted noise, so on the airborne as well as on the structure-borne noise and their spectra. Detailed analyses of measurement results have shown that the built-in vaned diffuser has numerous disadvantages, including: increase in the tonal and turbulent noise, increase in production costs and reduction of the flow rate, therefore, it could be omitted or replaced by a vaneless one. In this paper, an overview of the effects of the vaned diffuser on the aerodynamic, mechanical and electromagnetic noise origins at different operating conditions is given.

Polychlorinated biphenyls (PCBs) have been used in diverse purposes such as indoor paints. Removal of these paints with dust creating techniques, like sandblasting, will result in contamination of building surfaces with PCB-containing dust. Objectives of this study was to analyze the PCB concentrations on surfaces after sandblasting with silica using wipe samples and estimate the resulting health risks and further calculate the risk based acceptable PCB surface concentrations that do not cause incremental lifetime cancer risk higher that 10(-5) or does not cause immunosupression effects in residential use or in occupational settings. Both deterministic and probabilistic approaches were used. The total PCB concentrations on surfaces ranged from 10 to 1100 microg/m(2). Estimated cancer risk was 1.2 x 10(-4) for childhood exposure, 1.3 x 10(-5) for adult residents and 1.5 x 10(-5) for occupational exposure. Probabilistic risk assessment revealed that point estimates were quite reasonable and located between 45th and 79th percentiles on probabilistic distribution of risk. The noncancer risks were calculated as hazard quotients (HQ) which ranged from 3.3 to 35 depending on the exposure scenario. Acceptable surface concentrations based on noncancer effects that are protective for 95% of exposed population were 7 microg/m(2) for residential use, 65 microg/m(2) for residential use if only adults will be exposed and 140 microg/m(2) for occupational use. Preliminary cleanup experiment revealed that when contaminated dust was carefully removed with industrial vacuum cleaner and further washed with terpene containing liquid the surface concentration dropped below the acceptable levels calculated in this study.

Background Carpets are large reservoirs of the dust mite allergen Der p 1. The effect of vacuum cleaning on the distribution of Der p 1 in carpets is poorly understood. Methods Samples were cut from 7 used household carpets, all over 5 years of age. From each carpet, 10 samples were left untreated, 10 vacuumed with an upright vacuum cleaner, and 10 vacuumed with a canister vacuum cleaner. Each section was then cut into 3 horizontal layers: the top 2 mm, the remainder of the carpet pile, and the carpet base. The mass of Der p 1 as a proportion of carpet volume was then determined. Results The concentrations of Der p 1 in each depth layer varied considerably between the 7 untreated carpets. In the top layer, Der p 1 concentrations were (median; 25th–75th percentiles): 41.9; 28.3–92.6 pg/mm3. For the middle layer they were similar (38.1; 22.4–108.5 pg/mm3), and for the carpet base, higher (212.4; 98.8–456.2 pg/mm3). In most cases, cleaning using either type of vacuum cleaner resulted in no significant reduction in allergen concentration throughout all depth layers. A subset of carpets showed an apparent increase in Der p 1 concentration in one or more layers following vacuum cleaning. In all tests Der p 1 was collected in the vacuum cleaners’ filter bags. Conclusions The depth-distribution of Der p 1 differs widely amongst used carpets. Vacuum cleaning changes the distribution of Der p 1 within such carpets but does not necessarily result in a reduction in the overall content.

Inadvertent soil ingestion, especially by young children, can be an important route of exposure for many environmental contaminants. The introduction of exterior soil into the interior environment is a significant element of the exposure pathway. The unintentional collection of outside soil on footwear followed by subsequent deposition indoors is a principal route of soil ingress. Here we have investigated likely rates of dry and wet soil deposition on indoor hard surface flooring as a result of mass transfer from soiled footwear. In this pilot study, testing involved both single track-in events (with deposition resulting from a single progression of transfer steps) and multiple tracking actions (with deposition and dispersion resulting from repeated transfer steps). Based on soil mass recovery from the floor surface it was found that any contamination introduced by one-time track-in events was of limited spatial extent. In contrast, under repeated tracking conditions, with multiple soil incursions, widespread floor surface contamination was possible. Soil mass recovery was accomplished by brushing, by vacuum cleaner removal and by wet wiping. All the clean-up methods operated imperfectly and failed to remove all initially deposited soil. The level of floor surface soiling that resulted from the track-in tests, and the incomplete clean-up strongly suggest that under unrestricted transfer conditions rapid accumulation and dispersal of soil on indoor flooring is likely.

This paper presents the potential of modelling a product's life-cycle using the Unified Modelling Language (UML). The potential benefits and limitations are discussed. An example of a vacuum cleaner is cited in support of this approach. Model consistency across the various life cycle stages of the product is of major concern and an algorithm for constraint management is proposed and prospective research directions highlighted.

The objectives of this study were to develop a leaf picking device for cucumber and to evaluate its performance. The picking device consisted of a picking rotor composed from knives and brushes, a motor and a vacuum cleaner. In laboratory experiments the performances of suction, cutting, torque and shredding were investigated to achieve the optimum mechanical setting. In a greenhouse experiment, the performance of suction, cutting and shredding were investigated.

A product consists of various sub-functions elaborated by alternative design principles which results in many combinations. In collaborative design, designers expect that their preferences over the combinations be respected during the combination process of sub-functions, resulting in compatible combinations. We formulate the selection of compatible combinations as a combinatorial problem by: (i) defining a design principle as a list of variables with their domain and direction of designer's preferences, (ii) considering constraints among design principles, (iii) characterizing the compatibility level of combinations. A vacuum cleaner is considered with dust bag, plastic bin or cyclonic design principles for the dust collection sub-function.

This paper addresses the problem of the detailed quality end-test of vacuum cleaner motors at the end of the manufacturing cycle. For the prototyping purposes a test rig has been constructed and is presented in short. The diagnostic system built hereto takes advantage of vibration, sound and commutation analysis as well as parity relation checks. The paper focuses on the sound analysis module and provides two main contributions. First, an analysis of sound sources is performed and a set of appropriate features is suggested. Second, efficient signal processing algorithms are developed in order to detect and localise bearing faults, defects in fan impeller, improper brush–commutator contacts and rubbing of rotating surfaces. A thorough laboratory study shows that the underlying diagnostic modules provide accurate diagnosis, high sensitivity with respect to faults, and good diagnostic resolution.

In-depth and automatic quality end-tests in modern manufacturing represent an important means for the assurance of top-quality and flawless products. Tough competition on the market of vacuum cleaner motors is increasing the need for fast, reliable and objective quality assessment of every single unit at the end of the assembly cycle. As a step towards meeting these objectives, a prototype version of the diagnostic system for quality tests of vacuum cleaner motors has been designed. The core of the system contains four modules for features extraction that employ, respectively: analysis of commutation, vibration analysis, sound analysis and check of parity relations. The symptoms resulting therefrom are processed by an approximate reasoning module, which utilises the technique referred to as the transferable belief model (TBM). The comprehensive diagnostic procedure is able to clearly distinguish a faulty motor from a non-faulty one and to infer about the tentative fault location. Main contributions of the paper refer to the novel feature extraction procedures, which provide a reliable estimate of the motor's condition. The system performance has been surveyed on a set of about 100 motors subjected to a detailed experimental study. An excerpt is also presented, reflecting the key properties of the diagnostic system performance, such as precision, accuracy, robustness and reliability.

We conducted a cleaning trial in 40 northern New Jersey homes where home renovation and remodeling (RR) activities were undertaken. Two cleaning protocols were used in the study: a specific method recommended by the US Department of Housing and Urban Development (HUD), in the 1995 "Guidelines for the Evaluation and Control of Lead-Based Paint Hazards in Housing," using a high-efficiency particulate air (HEPA)-filtered vacuum cleaner and a tri-sodium phosphate solution (TSP); and an alternative method using a household vacuum cleaner and a household detergent. Eligible homes were built before the 1970s with potential lead-based paint and had recent RR activities without thorough cleaning. The two cleaning protocols were randomly assigned to the participants' homes and followed the HUD-recommended three-step procedure: vacuuming, wet washing, and repeat vacuuming. Wipe sampling was conducted on floor surfaces or windowsills before and after cleaning to evaluate the efficacy. All floor and windowsill data indicated that both methods (TSP/HEPA and non-TSP/non-HEPA) were effective in reducing lead loading on the surfaces (P0.001). When cleaning was applied to surfaces with initial lead loading above the clearance standards, the reductions were even greater, above 95% for either cleaning method. The mixed-effect model analysis showed no significant difference between the two methods. Baseline lead loading was found to be associated with lead loading reduction significantly on floors (P0.001) and marginally on windowsills (P = 0.077). Such relations were different between the two cleaning methods significantly on floors (P0.001) and marginally on windowsills (P = 0.066), with the TSP/HEPA method being favored for higher baseline levels and the non-TSP/non-HEPA method for lower baseline levels. For the 10 homes with lead abatement, almost all post-cleaning lead loadings were below the standards using either cleaning method. Based on our results, we recommend that contractors or homeowners can use a household vacuum cleaner and a household detergent to clean lead-contaminated environments after RR activities when HUD-recommended equipment is not available.

A prototype of a diagnostic system for quality end-tests of vacuum cleaner motors is presented. The core of the system are four modules for features extraction based on vibration analysis, sound analysis, analysis of commutation and check of parity relations respectively. The symptoms resulting there from are processed by a reasoning module relying on the Transferable Belief Model (TBM). The result of such a comprehensive diagnostic procedure is detection of faulty motors and localisation of tentative fault origins along with accompanying belief measures. Attributes of the system performance and an excerpt from results obtained in an experimental study over a series of motors are provided.

Static extraction, supercritical fluid extraction (SFE), pressurized liquid extraction (PLE) and Soxhlet extraction were compared for simultaneous extraction of di(2-ethylhexyl) phthalate (DEHP) and nonionic surfactants from house dust. Homogenized office floor dust from a vacuum cleaner dust bag (“standard dust”) was used for the evaluation. One portion of the extracts was used for analysis of nonionic surfactants with LC–MS and another portion was used for DEHP analysis with GC–MS. The extraction yield of DEHP was comparable for all the methods whereas SFE and PLE were the most efficient extraction techniques for the nonionic surfactants. The PLE extraction was found most suitable as a routine method for simultaneous extraction of both types of compounds and was used in a field study of floor dust from 15 Danish schools. The mean concentration of DEHP in the school dust samples was ∼4 times higher than observed in other studies of dust from homes in different countries. The concentrations of nonionic surfactants were one order of magnitude lower than soap and linear alkylbenzene sulfonates measured in other studies of floor dust from offices and other public buildings. However, for the first time nonionic surfactants have been identified in house dust.

Lead in house dust has long been recognized as a principal source of excess lead absorption among children at the Bunker Hill Superfund Site (BHSS) in northern Idaho. House dust lead concentration from homeowner's vacuum cleaner bags has been monitored since the epidemic of childhood lead poisoning in 1974. Geometric mean house dust lead concentrations decreased from >10000 mg/kg in 1974 to approximately 4000 mg/kg in 1975, in response to air pollution control initiatives at the defective primary lead smelter. After smelter closure, 1983 mean dust lead concentrations were near 3000 mg/kg and were most dependent on soil sources. Following emergency soil removals from public areas and roadsides and fugitive dust control efforts in the mid-1980s, house dust lead decreased by approximately 40-60% to 1200-1500 mg/kg. In 1992, a cleanup goal of 500 mg/kg dust lead community average, with no individual home exceeding 1000 mg/kg, was adopted. This goal was to be achieved by a combination of contaminated soil removals and fugitive dust control efforts throughout the 21 square mile BHSS. Continual reductions in house dust lead concentrations have been noted throughout the residential area soil cleanup. Geometric mean house dust lead concentrations averaged approximately 500-600 mg/kg from 1996 to 1999 and dropped below 500 mg/kg in 2000. Analysis of these data indicates that approximately 20% of the variance in dust lead concentrations is attributed to yard, neighborhood, and community soil lead concentrations. Since 1996, dust lead concentrations and dust and lead loading rates have also been measured by dust mats placed at entryways into the homes. Neighborhood soil lead concentrations, household hygiene, the number of adults living in the home, and the number of hours a child spends outdoors in summer explain approximately 26% of the variance in mat dust lead loading rates. It is estimated that post-remedial house dust lead concentrations will stabilize at 400-500 mg/kg, as compared to approximately 200 mg/kg in socio-economically similar background communities; the difference possibly attributed to residual soil concentrations (3-6 times background), recontamination of rights-of-way, tracking of non-residential mining district soils and dusts, fugitive dusts associated with the remediation, and residual structural or carpet dusts.

A method was developed to analyse linear alkylbenzene sulfonates (C10-C13 LAS) in vacuumed floor dust in office buildings by the use of HPLC chromatography. Floor dust was sampled with a specially designed vacuum cleaner and fractionated into fibres and particles. The content of LAS in the particle fraction of floor dust sampled from seven different public buildings varied between 34 microg LAS g(-1) dust and 1,500 microg LAS g(-1) dust, while the content of the fibre fractions was generally higher with up to 3,500 microg LAS g(-1) dust. The use of a cleaning agent with LAS resulted in increases approximately 30% of the amount of LAS in the floor dust after floor wash relative to just before floor wash. However, the most important source of LAS in the indoor floor dust appeared to be residues of detergent in clothing. Thus, a newly washed shirt contained 2,960 microg LAS g(-1) clothing. The analysis of the office dust samples indicated that LAS (and probably other detergents) might be of importance for the indoor environment.

In 1998, 100 g of highly tritiated carbon dust and flakes containing an estimated 1 g of Tritium were removed from the JET machine using a vacuum cleaner with a cyclone dust separator during the Remote Exchange of the divertor tiles. Two pots of flakes were filled and transferred, in drums, to the Active Gas Handling System where they were stored and ventilated to the Exhaust Detritiation System (EDS). A ventilated glovebox allowed the material to be handled safely and undergo calorimetric tritium assay. The glovebox had an air atmosphere with a continuous purge to the EDS with a facility for argon purging of isolators within the glovebox. Design features of the glovebox, operational experiences in handling tritiated carbon with a specific activity in excess of 1 TBq/g and results of the tests are discussed.

Floor dust from Danish offices was collected and analyzed. The dust was to be used in an exposure experiment. The dust was analyzed to show the composition of the dust which can be a source of airborne dust indoors. About 11 kg of dust from vacuum cleaner bags from seven Danish office buildings with about 1047 occupants (12 751 m 2 ) was processed according to a standardized procedure yielding 5.5 kg of processed bulk dust. The bulk dust contained 130.000–160.000 CFU g −1 microorganisms and 71.000–90.000 CFU g −1 microfungi. The content of culturable microfungi was 65–123 CFU 30 g −1 dust. The content of endotoxins ranged from 5.06–7.24 EU g −1 (1.45 ng g −1 to 1.01 ng g −1 ). Allergens (ng g −1 ) were from 147–159 (Mite), 395–746 (dog) and 103–330 (cat). The macro molecular organic compounds (the MOD-content) varied from 7.8–9.8 mg g −1 . The threshold of release of histamine from basophil leukocytes provoked by the bulk dust was between 0.3 and 1.0 mg ml −1 . The water content was 2% (WGT) and the organic fraction 33%. 6.5–5.9% (dry) was water soluble. The fiber content was less than 0.2–1.5% (WGT) and the desorbable VOCs was 176–319 μg g −1 . Most of the VOC were aldehydes. However, softeners for plastic (DBP and DEHP) were present. The chemical composition includes human and animal skin fragments, paper fibers, glass wool, wood and textilefibers and inorganic and metal particles. The sizes ranged from 0.001–1 mm and the average specific density was 1.0 g m −3 . The bulk dust was resuspended and injected into an exposure chamber. The airborne dust was sampled and analyzed to illustrate the exposures that can result from sedimented dirt and dust. The airborne dust resulting from the bulk dust reached concentrations ranging from 0.26–0.75 mg m −3 in average contained 300–170 CFU m −3 . The organic fraction was from 55–70% and the water content about 2.5% (WGT). The content of the dust was compared to the similar results reported in the literature and its toxic potency is estimated to be relatively low. The storage of the bulk dust during the experiment had little effect on the specific biological and chemical composition.

Background: High-quality vacuum cleaners and vacuum cleaner bags are often recommended to allergic patients as a means of reducing indoor allergen exposure. A number of vacuum cleaners on the market today claim to capture 99.9% of particles 0.3 μm or larger entering the vacuum cleaner, and many vacuum cleaner bags are now being sold as microfiltration bags. Objective: The purpose of this study was to compare the allergen-trapping abilities of vacuum cleaners and to use a new technique for testing vacuum cleaner bags that are recommended for allergic patients. Methods: Vacuum cleaners were tested in an 18-m 3 laboratory room permeated with dust containing high levels of cat allergen by using techniques previously described. Air was sampled with parallel filters in conjunction with a particle counter. The filters were assayed by ELISA for cat allergen (Fel d 1). Vacuum cleaner bags were tested by using a modified dust trap to pull sieved house dust containing a known amount of Fel d 1 across the material used for the bag. Allergen passing through the bag was trapped on a filter covering the exit of the trap and analyzed for Fel d 1. Results: In general, vacuum cleaners designed for allergic patients leaked lower amounts of allergen ( 3 ) than that found in our previous studies ( 3 ). Single-layer vacuum cleaner bags performed poorly (1250-2640 ng recovered) compared with most of the 2- and 3-layer microfiltration bags (0.53-2450 ng recovered). The range of allergen recovered from the 2-layer bags (0.93-2450 ng recovered) highlighted the variability found between manufacturers. Conclusion: The results suggest that although allergen leakage has been reduced, there is still room for improvement. A method of testing allergen leakage by using Fel d 1 should be applied to vacuum cleaners and bags recommended for allergic patients. (J Allergy Clin Immunol 1999;104:1079-83.)

Vacuum cleaners may increase the level of airborne allergens by leakage through the cleaners or by disturbance of floor dust by the exhaust air produced.The aim of this study was to evaluate the short-term effect of vacuum cleaning with two different types of cleaners on airborne cat allergen analyzed by a biologic and by an immunochemical test.Ten homes with cats were cleaned in random order with a 1-week interval by a traditional canister type vacuum cleaner (T) and a semi-stationary vacuum cleaner (S) that conducts the air to the exterior through a valve in the wall. Airborne particles were collected by air sampling for 2 hours and cat allergen, Fel d 1, was quantified biologically by basophil histamine release test (HR test) and immunochemically by enzyme linked immunosorbent assay (ELISA).Using the S resulted in smaller amounts of airborne cat allergen than the T (mean 2.1 ng/m3 air (range .8 to 12.5) versus 5.2 ng/m3 (1.3 to 13.3), P.002 measured by ELISA). Results from ELISA and HR test correlated well (r = .91, P.001).The use of S with exhaust to the outside of the dwelling gave rise to less airborne low particle size allergen during the cleaning procedure than a T method. The basophil histamine release test could be a valid alternative method to establish allergen content in environmental samples especially in allergen systems with no available monoclonal antibodies.

Disinfection in animal houses means always a combination between cleaning and disinfection because the high amount of organic material present in such an environment will neutralize rapidly each disinfectant brought to the surface if no cleaning step had been done before. Depending on the kind of material, cleaning gives a 3 log reduction of total bacterial count on the surface and disinfection another 3 log reduction. This means that under practical conditions generally 103 cfu of bacteria remain per cm2 of surface, mostly sporeformers. The choice of disinfectant depends on the purpose of disinfection. In the case of notifiable diseases, it must be active against a defined pathogen. In the case of prophylactic disinfection, it must be active against a broad spectrum of microorganisms. Only disinfectants which are tested for their activity on surfaces which are representative for animal houses e.g. wood should be used, otherwise the failure under practical conditions can be predicted and work, as well as money, will be wasted. The optimal temperature for the liquids used in cleaning and disinfection is 40°C and the optimal temperature of surfaces is 20°C. Colder surfaces require higher concentrations of active substances in the solution, below 10°C the effect of practical disinfection is incomplete. Low air humidity and high air velocity have a negative influence on the action of most disinfectants on surfaces. The amount of disinfectant necessary to disinfect a surface in an animal house is at least 0.4 l/m2. Transport vehicles are very difficult to disinfect, especially in winter-time. They should be cleaned with hot water, the remaining liquid should be removed by a suitable vacuum cleaner and the concentration of the disinfectant should be elevated at least for the factor 3. Mechanic action will improve the disinfecting effect in vehicles as well as preliminary disinfection prior cleaning.

Pilot investigations using stable lead isotope and scanning electron microscopic analyses have been undertaken in different environments ranging from mining and smelting to urban in order to better understand the source of, and relationships between, soil and house dust. House dust is characterised by vacuum cleaner dust and/or surface wipes and compared with long-term dust (dust fall) accumulations over a > 3-month interval or with airborne particulates. Finer grain sizes of soils have lead concentrations from 2 to 9 times those measured in the bulk fractions. In Broken Hill isotopic ratios show that the major source of lead in soils is from the orebody, with rare examples containing lead from paint sources. In inner Sydney, soil lead values vary from 37 to 2660 ppm Pb in bulk samples and up to 3130 ppm in the finer fractions. The lead may be from diverse sources such as gasoline or paint. Finer fractions of vacuum cleaner dust from both Broken Hill and Sydney may contain up to three times the amount of lead measured in the bulk samples. In Broken Hill, the percentages by weight of total lead in the −250-μm fraction range from 11 to 51%. Bulk vacuum cleaner dusts from Broken Hill contain up to 4490 ppm Pb. Bulk vacuum cleaner dusts from inner Sydney contain up to 2950 ppm Pb. Isotopic variations in fractions of vacuum cleaner dust containing > 1000 ppm Pb from inner Sydney indicate that the lead in dust has come from different sources and such differences lessen the usefulness of analyses of bulk vacuum cleaner dust. Our results reinforce the importance of analysing the finer fraction of soil and house dust, especially those in the −150-μm (or even −100-μm) fraction for soils and the −100-μm fraction for vacuum cleaner dust. Dust-fall accumulations have many advantages over more conventional methods for estimating lead in house dust, such as vacuum cleaner dust or surface wipes. These advantages include: low cost; no power source required; can be set up by a technician; minimal inconvenience to householder (i.e., no power required, no noise, out of the way, a few minutes to set up and collect); integrates lead flux over a specific period; usually unbiased (in contrast to vacuuming or wipes where the householder may clean prior to a sampling visit); easy to ‘control’ by placement of other dishes in the same house. For Broken Hill, a strong correlation ( r = 0.95) was obtained between the isotopic composition of lead in blood and dust-fall accumulation.

The management of seven children with vacuum cleaner friction burns is described. Six of the children sustained full thickness burns. Four were treated operatively. Indications for surgery are outlined and important accident prevention strategies are highlighted.

Background: Vacuum cleaners are essential for the removal of dust from the surface of carpets; however, they may also contribute to airborne dust both by leakage through the cleaner and disturbance of floor dust. Methods: The present studies used established techniques for measuring airborne Fel d I to study the effects of vacuum cleaners on airborne cat allergen under laboratory conditions and in houses with cats. Nine different models were loaded with dust containing 50 mg Fel d I and run for 15 minutes in a laboratory room (volume∼18 m 3 ). Leakage was expressed as the airborne concentration of allergen in nanograms per cubic meter. Results: Cleaners incorporating a double-thickness dust bag either did not leak, that is, less than 0.4 ng Fel d I/ m 3 or had minor leakage∼5 ng/ m 3 . Vacuum cleaners with single-thickness paper bags leaked more, that is, 15 to > 90 ng/m 3 with the exception of the cleaner with an efficient outer bag. Detailed studies on a vacuum cleaner that leaked showed that placing dust in the bag, replacing the dust bag with a double-thickness bag, and placing an electrostatic filter over the exhaust reduced levels from greater than 90 ng/m 3 to less than 2 ng/m 3 . Two water-filter vacuum cleaners each emitted cat allergen (up to > 100 ng/m 3 ) with a mean of ∼90% on particles less than 2.5 μm diameter. This emission could be almost completely controlled by taping electrostatic filter paper over the air outlet. Conclusions: In houses with cats, different models of vacuum cleaners could either reduce or increase total airborne allergen, and could also selectively increase certain particle sizes. These results suggest that cat allergen is a good model for studying the effectiveness of vacuum cleaners recommended to allergic patients.

The effects of some everyday activities on concentrations of airborne fungal spores in Finnish home environments were examined to provide basic information needed to evaluate the importance of varying levels of fungal spores in the air. The activities studied were opening of a cellar door, handling of different organic materials, resuspension of spores as a result of cleaning activities and transport of spores on clothes and pets. Airborne spores were sampled using six-stage impactors and surface samples were taken from the materials used in the experiments with sterile swabs or with a vacuum cleaner. Most of the activities had an obvious effect on the spore counts. However, vacuum cleaning, humidifying of house plants and baking caused no marked changes in the spore concentration. The short-term activities studied in a house explain most of the wide variation previously observed in fungal spore concentrations in indoor air. These activities have to be taken into account when designing sampling strategies for airborne fungi, in evaluation of the microbial quality of indoor air and when making comparisons with recommended values.

Environmentally clean products and manufacturing technologies are vital in order to be competitive in the future. Beside functional requirements product design must be more and more oriented on ecological effects throughout the life-cycle of products. Life-cycle-analysis permits the comparison and evaluation of various alternatives from the ecological and economical point of view. The method for life-cycle-analysis is illustrated. For two alternative suction tubes for a vacuum cleaner the first approach for an “ecobalance” is outlined.