Safety Considerations during Different Stages of a Project Life Cycle in the Manufacturing Industry

At sites with multiple employers, efficient safety management is essential to ensure safety for both customers and providers. However, implementing effective safety management is challenging, particularly for companies that provide services. Provider companies encounter difficulties managing the safety of service projects for many reasons, including the variety of customers and changes in work environment. Proper preparation and integration of safety into the different project life cycle stages improves safety, but the topic has not received much attention to date. This article discusses the integration of safety considerations into service projects. Material was collected from Finnish manufacturing companies via interviews and a questionnaire. The results show that systematic methods for developing and producing services have not been adopted in the provider companies, but these are often implemented as a result of practical experience. On the other hand, providers and customers both believed that safety is taken into account during different stages of a given service project—safety issues were to some extent taken into account during the tendering and contract stages of a project, and preventive safety measures were commonly implemented during the delivery of services. However, safety performance often was not evaluated after completion of work. For this reason, companies may not have an accurate estimation of each other's safety performance in these types of multi‐employer situations. The results of this study can be used in provider organizations to help systematize safety considerations during service projects and to focus efforts on the most essential points of service project safety management.     

Effect of strain rate on the strain-induced <Emphasis Type="Italic">γ</Emphasis> → <Emphasis Type="Italic">α</Emphasis>′-martensite transformation and mechanical properties of austenitic stainless steels

The effect of strain rate on strain-induced γ → α′-martensite transformation and mechanical behavior of austenitic stainless steel grades EN 1.4318 (AISI 301LN) and EN 1.4301 (AISI 304) was studied at strain rates ranging between 3×10⁻⁴ and 200 s⁻¹. The most important effect of the strain rate was found to be the adiabatic heating that suppresses the strain-induced γ → α′ transformation. A correlation between the work-hardening rate and the rate of γ → α′ transformation was found. Therefore, the changes in the extent of the α′-martensite formation strongly affected the work-hardening rate and the ultimate tensile strength of the materials. Changes in the martensite formation and work-hardening rate affected also the ductility of the studied steels. Furthermore, it was shown that the square root of the α′-martensite fraction is a linear function of flow stress. This indicates that the formation of α′-martensite affects the stress by influencing the dislocation density of the austenite phase. Olson-Cohen analysis of the martensite measurement results did not indicate any effect of strain rate on shear band formation, which was contrary to the transmission electron microscopy (TEM) examinations. The β parameter decreased with increasing strain rate, which indicates a decrease in the chemical driving force of the α → α′ transformation.     

Microstructures of a powder metallurgy-hot-isostatically pressed super duplex stainless steel forming in industrial heat treatments

The microstructures of a powder metallurgy/hot-isostatically pressed super duplex stainless steel, designed and manufactured for massive components of paper machines, were studied after heat treatments simulating the industrial production. It was shown that copper precipitates in the ferrite phase as ɛ phase. Morphologically, the copper precipitates are of two types—nearly spherical particles of typical size from 30 to 50 nm, and rodlike particles 30- to 35-nm wide, and up to 700-nm long. The main observations on copper precipitation in modern super duplex stainless steels are similar to those in low-alloy steels. Copper particles were shown to be the nucleation sites for the formation of secondary austenite and to pin the boundaries of sigma phase.     

Improvement of a-C:H film adhesion by intermediate layers and sputter cleaning procedures on stainless steel, alumina and cemented carbide

The adhesion of amorphous hydrogenated carbon (a-C:H) films deposited in a radio frequency (r.f.) plasma discharge on stainless steel, alumina and cemented carbide with different intermediate layers (Ni, Ti and TiC) and sputter cleaning procedures was studied. The composition of the carbon films and the intermediate layers as well as the interface between the coating and the substrate was determined by secondary ion mass spectroscopy (SIMS). The adhesion experiments were carried out using a scratch tester. Tested specimens were also studied by scanning electron microscopy (SEM) to reveal the morphology of the coatings and the scratches.

Without any intermediate layer, the a-C:H coatings generally had insufficient adhesion to the substrate materials studied. For stainless steel and cemented carbide substrates, the TiC intermediate layer and, for alumina substrates, the titanium intermediate layer gave the best adhesion values evaluated by the scratch test. Also, the sputter cleaning of the substrates prior to deposition was necessary for sufficient adhesion of the coating. The intermediate layers also change the failure mode of the coating in the scratch test in some cases.     

Conjugate gradient optimization applied to a copper converter model

Exothermic copper conversion reactions release heat energy which can be used to melt fluxing materials required in the reverberatory furnace. Oxygen enrichment of the air supplied to the converter results in shorter processing times and increased ability to smelt flux but with increased air supply costs.

A conjugate gradient method in function space is employed to determine the optimal rate of flux addition to a calibrated mathematical model of the converter for various levels of enriched oxygen. The smelting of flotation concentrates in the converter and the effect of converter parameter variations in the optimal solutions are also considered. The mathematical model is derived from material and heat balance relationships and is calibrated using data from an operating converter.

The paper also shows how the method of conjugate gradients in function space can be applied to a bounded control problem, in particular, one in which intervals of singular optimal control arise. The conjugate gradient method is found to converge substantially faster to a higher value of the performance index than a conventional steepest ascent procedure.     

Wireless ATM MAC performance evaluation,a case study: HIPERLAN type 1 vs. modified MDR

This paper deals with wireless ATM and in particular with MAC (Medium Access Control) mechanisms. The requirements for wireless ATM MAC are discussed, and contentionbased and TDMA/reservation based MAC protocols are compared. The objective is to find out the suitability of current wireless MAC schemes for ATM interworking, in comparison to new wireless ATM MAC proposals. Two candidate mechanisms, EYNPMA used in HIPERLAN type 1, and a modified MDR protocol, are discussed in more detail and their performance in different traffic scenarios is evaluated through simulations.     

Reconstruction of 3-D geometry using 2-D profiles and a geometric prior model

A method has been developed to reconstruct three-dimensional (3-D) surfaces from two-dimensional (2-D) projection data. It is used to produce individualized boundary element models, consisting of thorax and lung surfaces, for electro- and magnetocardiographic inverse problems. Two orthogonal projections are utilized. A geometrical prior model, built using segmented magnetic resonance images, is deformed according to profiles segmented from projection images. In the authors' method, virtual X-ray images of the prior model are first constructed by simulating real X-ray imaging. The 2-D profiles of the model are segmented from the projections and elastically matched with the profiles segmented from patient data. The displacement vectors produced by the elastic 2-D matching are back projected onto the 3-D surface of the prior model. Finally, the model is deformed, using the back-projected vectors. Two different deformation methods are proposed. The accuracy of the method is validated by a simulation. The average reconstruction error of a thorax and lungs was 1.22 voxels, corresponding to about 5 mm     

Vacuum extraction based response equipment for recovery of fresh fuel spills from soil

Accidental overturns of fuel tankers can have, depending on soil types, severe consequences. This applies, particularly in areas of shallow soils where the groundwater is located 2-4m below the ground surface. By rapid, vacuum extraction based recovery emergency services, which would normally be the first to arrive on the scene, could minimize consequences of fresh fuel spills and even prevent groundwater contamination, the primary purpose of emergency response. Powerful vacuum extraction-based response (PER), equipment has been developed to recover freshly spilt volatile fuels from the soil, primary by emergency services, but also by other trained responders. The main components of mobile PER-equipment are perforated extraction pipes, a recovery vacuum tank, a vacuum pump and an incinerator. The PER-equipment has been tested in summer and sub-zero winter conditions, and in both cases 50-80% of fresh gasoline spilled into sandy soil was recovered during the first 2h of operation. Gasoline was recovered in both liquid and vapor form, and hydrocarbon vapors were destroyed by controlled incineration at a safe distance from the spill. Recovery of less volatile diesel oil is not so effective from the sandy soil, but about 30% of it could be pumped from a fresh pool directly after a seepage time of 15 min.     

Conversion of magnetocardiographic recordings between two different multichannel SQUID devices

Comparison of biomagnetic measurements performed with different multichannel magnetometers is difficult, because differing sensor types and locations do not allow measurements from the same locations in respect to the body. In this study, two transformation procedures were utilized to compare magnetocardiograms (MCG) recorded with two different multisensor systems. Signals from one sensor array were used to compute parameters of a multipole expansion or minimum-norm estimates at 1-ms steps over the cardiac cycle. The signals of the second sensor array were then simulated from the computed estimates and compared against measured data. Both the multipole- and the minimum-norm-based transformation method yielded good results; the average correlation between simulated and measured signals was 93%. Thus, the methods are useful to compare MCG recordings performed using differing sensor configurations, e.g., for multicenter patient studies. This study provides the first empirical basis for assessing the transformation of MCG data of differing devices by general model-based field reconstructions.     

Fatty acid composition of erythrocyte,platelet, and serum lipids in strict vegans

The fatty acid composition of erythrocytes, platelets, and serum lipids was compared between subjects who had been eating a strict uncooked vegan diet (“living food”) for years and omnivore controls. The vegan diet contains equal amounts of fat but more monounsaturated and polyunsaturated and less saturated fatty acids than the mixed diet of the control group. In vegans, the proportion of linoleic acid was greater in all lipid fractions studied. Also, the levels of other n−6 fatty acids were greater, with the exception of arachidonic acid levels, which were similar in most fractions. In erythrocytes, platelets and serum phospholipid fractions, this increase was mainly at the expense of the n−3 fatty acids. The proportions of eicosapentaenoic and docosahexaenoic acid were only 29–36% and 49–52% of those in controls, respectively. In vegans the ratio of n−3 to n−6 fatty acids was only about half that in omnivores. In addition to the lower levels of n−3 fatty acids, the proportions of palmitic and stearic acids were lower in serum cholesteryl esters, triglycerides and free fatty acids of vegans. The proportion of oleic acid was slightly lower only in serum cholesteryl esters and erythrocyte phosphatidylserine. The results show that, in the long term, the vegan diet has little effect on the proportions of oleic and arachidonic acids, whereas the levels of n−3 fatty acids are depressed to very low levels with prolonged consumption of the high linoleic and oleic acid components of this diet.