Stanowisko badawcze do oceny efektów utwardzania mas ze szkłem wodnym

W pracy przedstawiono wyniki badań nad możliwością zastosowania nowego stanowiska badawczego do oceny, na podstawie końcowejzawartości wody, finalnego efektu utwardzania wybranymi metodami mas ze szkłem wodnym. Badania wykonano na innowacyjnym,mobilnym stanowisku mikrofalowej linii szczelinowej wykorzystującej zjawisko występowania fali stojącej w falowodzie. Badaniompoddano pięć mas sporządzonych z dostępnymi w handlu gatunkami szkła wodnego, które utwardzano trzema, wybranymi metodami:mikrofalową, klasyczną oraz w procesie CO2. Wykazano, na przykładzie mas ze szkłem wodnym, że prezentowane, mobilne stanowiskopomiarowe może, na podstawie określenia końcowej zawartości wody, służyć z powodzeniem do oceny ostatecznego efektu utwardzaniamas formierskich i rdzeniowych

Determination of the binder in sand molds with the use of microwaves

The paper presents results of preliminary examinations of possibility to measure binder content in traditional moulding sands using a new method employing electromagnetic waves. The presented examinations were carried-out with use of an innovative test station, the so-called microwave slot line. The measurements of binder content in moulding sand were based on the results of power balance investigation of microwaves affecting the specimen. An advantage of the suggested, new method of binder content measurement is short measuring time

Examination and analysis of influence of compaction degree on dielectricproperties of moulding sand components

In the paper, presented are results of a research on influence of compaction degree on dielectric properties of components of moulding sands. During recent years, intensive research works on possibilities of using microwave heating in foundry technique are carried-out. However, introduction of such innovative, environment-friendly and efficient heating processes to foundry technologies is accompanied by a shortage of basic knowledge about behaviour of components of moulding sands in microwave field. In this case, of particular importance becomes knowledge of electrical properties of components of moulding and core sands, i.e. their permittivity εr and dielectric loss factor tgδ that characterise efficiency of absorbing electromagnetic radiation and thus prove effectiveness of the heating process

Effect of compaction degree on permittivity of water-glass containing moulding sand

The presented basic research was aimed at determining a correlation between compaction degree of moulding sand and its permittivity εr at 2,45•109 s-1. The measurement results make a basis for mathematical description of a multilayer technological system as is a combination of moulding sand and foundry instrumentation. Analysis of the results shows that compaction significantly influences permittivity of the sandmix containing water-glass, because permittivity value increases with increasing compaction degree

Are older people putting themselves at risk when using their walking frames?

Background Walking aids are issued to older adults to prevent falls, however, paradoxically their use has been identified as a risk factor for falling. To prevent falls, walking aids must be used in a stable manner, but it remains unknown to what extent associated clinical guidance is adhered to at home, and whether following guidance facilitates a stable walking pattern. It was the aim of this study to investigate adherence to guidance on walking frame use, and to quantify user stability whilst using walking frames. Additionally, we explored the views of users and healthcare professionals on walking aid use, and regarding the instrumented walking frames (‘Smart Walkers’) utilized in this study. Methods This observational study used Smart Walkers and pressure-sensing insoles to investigate usage patterns of 17 older people in their home environment; corresponding video captured contextual information. Additionally, stability when following, or not, clinical guidance was quantified for a subset of users during walking in an Activities of Daily Living Flat and in a gait laboratory. Two focus groups (users, healthcare professionals) shared their experiences with walking aids and provided feedback on the Smart Walkers. Results Incorrect use was observed for 16% of single support periods and for 29% of dual support periods, and was associated with environmental constraints and a specific frame design feature. Incorrect use was associated with reduced stability. Participants and healthcare professionals perceived the Smart Walker technology positively. Conclusions Clinical guidance cannot easily be adhered to and self-selected strategies reduce stability, hence are placing the user at risk. Current guidance needs to be improved to address environmental constraints whilst facilitating stable walking. The research is highly relevant considering the rising number of walking aid users, their increased falls-risk, and the costs of falls. Trial Registration Not applicable

Possibilities of using microwave heating in disposal process of thermo and selfsetting sandmixes

The paper presents a semi-industrial reactor designed for microwave utilization of waste moulds and cores made of moulding sands prepared in furane resin technology. It was found that a possibility exists of effective incinerating this way prepared residues of cores separated from moulding sands or waste moulds left after casting. The preliminary tests evidenced that microwave heating is an effective way of disposing waste moulding sands and the applied apparatus permits effective control of the microwave heating process