Caregivers’ attitudes toward potential robot coworkers in elder care

Technological advances in robotics increase progressively. Elder care is one of the work areas which have potential to involve robotic workforce. So, it is important to focus on interaction between humans and potential robot workers to prepare the organization for possible challenges. The current study examined the relationships between trust in robots and anthropomorphism of robots, intention to work with robots and preference of automation levels. For this purpose, 102 caregivers who work for elder care in a nursing home (aged between 19 and 40) participated in an experimental study. According to the results, anthropomorphism of robots did not make any difference in terms of trust in them. Trust in robots was significantly related to intention to work and preference of automation levels. Organizations may consider employees’ trust in robots as an important factor before adapting them to workplace area.

     

Anionic polymerisation of methyl methacrylate with complex initiator system

Summary Polymerisation of methyl methacrylate was conducted by using alkyl lithium/dimethylsulfoxide (DMSO) system as initiator in toluene. A special attention was focused on using some lithium polyetheralkoxides as polymerisation promoters at ambient temperatures. Poly(methyl methacrylate) samples were characterized with Gel Permeation Chromatography (GPC), Nuclear Magnetic Resonance Spectroscopy (¹H NMR) and Differential Scanning Calorimetry (DSC). The positive effect of the μ/σ type ligands such as lithium 2-(2-methoxyethoxy)ethoxide (LiOEEM), 2-(methoxy)ethoxide (LiOEM) on controlling the living character, molecular weight, stereo regularity and the yield of the produced polymers was demonstrated. It has been found that this approach provided high polymerisation yields and low polydispersity but low initiator efficiency. Received: 9 April 2002 / Revised version: 10 May 2002 / Accepted: 15 June 2002     

The influences of glucose on corrosion behaviour of copper in chloride solution

Glucose is an organic molecule whose characteristics are corrosion inhibitors. The adsorption and inhibitory effect of glucose on copper surfaces in alkaline (pH 8.0) Chloride solutions were investigated by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). The data obtained indicate that glucose behaves as a mixed-type inhibitor by physically adsorbing onto copper surfaces according to the Langmuir isotherm. The inhibition activity of glucose increases with increasing the concentration of glucose.     

Cement composites with limestone dust and different grades of wood sawdust

This paper presents a parametric experimental study which investigates the potential use of limestone powder wastes (LPW) and wood sawdust wastes (WSW) combination for producing a lightweight composite as a building material. Some of the physical and mechanical properties of brick materials having various levels of LPW and WSW with different particle sizes are investigated. The obtained compressive strength, flexural strength, unit weight, ultrasonic pulse velocity (UPV) and water absorption values satisfy the relevant international standards. The results show the effect of high level replacement of WSW with LPW does not exhibit a sudden brittle fracture even beyond the failure loads, indicates high energy absorption capacity, reduce the unit weight dramatically and introduce a smoother surface compared to the current bricks in the market. It shows a potential to be used for walls, wooden board substitute, alternative to the concrete blocks, ceiling panels, sound barrier panels, absorption materials, etc. Recycling of unmanaged WSW and LPW as new brick material supplements appears to be viable solution not only to the environmental problem but also to the problem of the economic design of buildings.     

Investigation of factors affecting the dispersibility of clays and estimation of dispersivity

Dispersive soils have caused failure of many slopes and earth fills due to external and internal erosion. This study aims to investigate various factors used for identification of dispersivity and to develop some new approaches for the prediction of dispersivity of clays. To achieve this purpose, physical and index properties, as well as degree of dispersivity of 29 clay samples taken from five different locations in and around the city of Ankara were determined. Various statistical prediction models were used for prediction of new dispersivity classes obtained by weighting ranking method. It was determined that dispersivity classes obtained from physical and chemical dispersivity tests performed on the same clay samples using distilled water were different from each other. In addition, crumb and pinhole tests were performed by using test waters with varying TDS values on five selected samples to find the impact of water chemistry on dispersivity. It is concluded from all dispersivity tests that total dissolved salts (TDS) values and sodium percentage (SP) remarkably affect the degree of dispersivity, and the use of these two parameters give more reliable results for the determination of dispersivity. By considering all these facts and to predict the most reliable dispersivity class, all dispersivity classes obtained from physical and chemical dispersivity tests were reevaluated by a weighted ranking system, and new dispersivity classes were assigned. In order to estimate these new dispersivity classes, various statistical models were established by using results of chemical analysis of pore water of clay samples. For this purpose, prediction models including soft computing methods such as decision tree and logistic regression are used and most reliable prediction models having the highest prediction performance are suggested.     

Partial substitution of hydrogen for conventional fuel in an aircraft by utilizing unused cargo compartment space

Options are being actively sought in aviation to switch from petroleum-based fuels to alternative fuels, of which hydrogen is a promising candidate, despite challenges associated with its production and storage. The possibility is demonstrated in this study of using hydrogen in place of some mission fuel without making substantial aircraft modifications and while utilizing only available unused baggage space in the lower-deck cargo compartments of aircraft. The environmental impact reduction and weight increase are obtained accounting for a broad range of factors including aircraft model, seat capacity, passenger and baggage load factors, annual landing and take off cycles, container type, and costs of metal hydride and gaseous hydrogen storage units of various sizes. It is found that, while there may be a cost increase, CO₂ emissions are substantially reduced, by 25,000–570,000 tonnes annually in several cases and by up to 1.1 million tonnes annually for the 10 types of aircraft considered. It is also determined that with present technology, despite the low density of hydrogen, the weight of storage systems constitutes more of a challenge than their volume in aviation. Large-body aircraft are found to have more difficulties than the narrow-body aircraft regarding storage system weight. For the most frequently used narrow- and large-body aircraft considered, the number of the available containers within the required limits of weight and volume respectively are found to be 3 and 4 for the B 737-800 aircraft and 2 and 10 for the A 340-300 aircraft. Overall, the combined usage of hydrogen and kerosene investigated here may be feasible in the future, but is a challenging option with present technology and aircraft due to various factors.     

Performance of cryogenically treated M35 HSS drills in drilling of austenitic stainless steels

In this study, performance of cryogenically treated M35 high speed steel (HSS) twist drills in drilling of AISI 304 and 316 stainless steels was evaluated in terms of thrust force, surface roughness, tool wear, tool life, and chip formation. To present the differences in tool performance between untreated and treated drills, and machinability between AISI 304 SS and AISI 316 SS, a number of experiments were performed at different combinations of cutting speed, and feed rate. As the results of the conducted experiments, the treated drills showed better performance than untreated drills in terms of thrust force, surface roughness, and tool wear and tool life for both types of stainless steels. Tool lives of treated HSS drills in drilling of AISI 304 SS and AISI 316 SS improved 32% and 14%, respectively, when compared with untreated drills. Experimental results also showed that machinability of AISI 304 SS was harder than the machinability of AISI 316 SS.     

Comparative relationships of direct, indirect, and semi-direct ultrasonic pulse velocity measurements in concrete

An experimental study is conducted to compare direct, indirect and semi-direct ultrasonic pulse velocity (UPV) measurements on a total of 30 concrete blocks 30 × 30 × 25 cm³ in size that came from different mix batches and have cube compressive strength grades varying between 18.8 and 79.9 MPa. The correlations are established between the direct UPV and indirect UPV in the concrete casting direction as well as in the horizontal direction and semi-direct UPV measurements via statistical analysis. The statistical analysis reveals that the average value of direct UPV is 9%, 4%, and 4% higher than the average of indirect UPV in the casting direction, indirect UPV in the horizontal direction, and semi-direct UPV, respectively. The average value of indirect UPV in the horizontal direction is 5% higher than that in the casting direction. The text was submitted by the authors in English.     

Co-Fe films: effect of Fe content on their properties

The characterizations of Co-Fe films electrodeposited on Ti substrates under potentiostatic conditions were investigated as a function of the Fe content in the films. The compositional analysis was carried out by energy dispersive X-ray spectroscopy. Scanning electron microscopy used to analyze the surface morphology of the films revealed that the film surface became rather smooth with the increase of the Fe contents. X-ray diffraction patterns showed that the crystal structure changed depending on the Co:Fe ratio in the films. It was observed that the crystal structure converted from the predominant face-centered-cubic to the body-centered-cubic with increasing Fe content. All films showed anisotropic magnetic resistance, but their magnitudes decrease as the Fe content increases. Magnetic data obtained from by vibrating sample magnetometer revealed that the changes observed in the saturation magnetization and coercivity values may arise from the Fe content of the films. The different magnetic and magnetotransport properties may come from the structural differences caused by the Fe content.     

Photothermal Characterization of Nanocomposites Based on High Density Polyethylene (HDPE) Filled with Expanded Graphite

The effective thermophysical and optical properties of high density polyethylene (HDPE) filled with 50???m and 5???m particle sizes of expanded graphite (EG50, EG5) are characterized. The methods used were front- and back-detection modulated photothermal radiometry (FD-, BD-PTR) and BD-flash IR thermography. Results were interpreted according to one-dimensional heat diffusion models. The absolute thermal diffusivity was determined at low frequency from FD- and BD-PTR spectra, while the volumetric heat capacity, the thermal effusivity, and the optical absorption coefficient were determined from broad-band FD-PTR spectra. The directly obtained diffusivity values compare well with those calculated from the heat capacity and thermal effusivity, and with BD-flash results. The errors caused by the finite absorption coefficient of diluted samples are also evaluated and corrected for. A particle-size effect with the opposite influence on thermal and optical properties has been observed. Heat transport parameters of HDPE/EG composites are significantly enhanced (factor of 3 to 4 in thermal diffusivity) at low particle charge before reaching saturation above a 0.10 particle volume fraction. These features are explained in the framework of effective medium models by strongly non-spherical EG particles.