Hybrid carbon nanotube/nanodiamond structures as electron emitters for cold cathodes

The field emission properties of hybrid carbon nanotubes/nanodiamond structures produced by one-step chemical vapor deposition (CVD) process have been investigated in order to assess their application as electron emitters for cold cathodes. The electron emission properties of a series of samples have been investigated by current-pressure, current-voltage and current-time measurements with the aim of testing the emission stability under working conditions relevant to technological applications. Stable emission, high values of current density and lack of arcing have been observed during prolonged working cycles, and without degradation of the material structure.     

Design, implementation and clinical tests of a wire-based robot for neurorehabilitation.

This paper presents the development of and clinical tests on NeReBot (NEuroREhabilitation roBOT): a three degrees-of-freedom (DoF), wire-driven robot for poststroke upper-limb rehabilitation. Basically, the robot consists of a set of three wires independently driven by three electric motors. The wires are connected to the patient's upper limb by means of a splint and are supported by a transportable frame, located above the patient. By controlling wire length, rehabilitation treatment (based on the passive or active-assistive spatial motion of the limb) can be delivered over a wide working space. The arm trajectory is set by the therapist through a very simple teaching-by-showing procedure, enabling most common "hands on" therapy exercises to be reproduced by the robot. Compared to other rehabilitation robots, NeReBot offers the advantages of a low-cost mechanical structure, intrinsically safe treatment thanks to the use of wires, high acceptability by the patient, who does not feel constrained by an "industrial-like" robot, transportability (it can be easily placed aside a hospital bed and/or a wheelchair), and a good trade-off between low number of DoF and spatial performance. These features and the very encouraging results of the first clinical trials make the NeReBot a good candidate for adoption in the rehabilitation treatment of subacute stroke survivors. Clinical trials were performed with a 12-patient experimental group and a 12-patient control group. Resulted that the patients who received robotic therapy in addition to conventional therapy showed greater reductions in motor impairment (in terms of Medical Research Council score, the upper limb subsection of the Fugl-Meyer score, and the Motor Status Score) and improvements in functional abilities (as measured by the Functional Independence Measure and its motor component). No adverse effects occurred and the robotic approach was very well accepted. According to these results, the NeReBot therapy may efficaciously complement standard poststroke multidisciplinary rehabilitation and offer novel therapeutic strategies for neurological rehabilitation.     

Effect of nitrogen fertilisation levels on melon fruit quality at the harvest time and during storage

BACKGROUND: The quality of melon fruit depends upon many factors that can be affected by growing conditions and post-harvest management. The aim of this work was to investigate the effect of nitrogen fertilisation levels on the fruit quality at harvest time and during storage. Experiments were performed in an open field using melon plants (Cucumis melo L. Var. Reticulatus cv. Prodigio). The nitrogen (N) was applied through fertigation using four fertilisation levels: 0, 55, 110 and 165 kg ha⁻¹. After harvest the fruits were stored at 10 °C for 8 days. At harvest time the yield, flesh firmness, skin and pulp colours, content of carotenoids, total phenols, ascorbic acid (AsA) and ethylene production were measured on fruits differently fertilised. RESULTS: The total marketable fruit yield and fruit nitrogen content linearly increased with N levels. Antioxidant compounds decreased after storage but were not affected by N fertilisation levels. However, total carotenoids, total phenols, and AsA declined during storage. CONCLUSION: All the quality parameters did not appear to be affected by N level at either harvest time or after storage. Therefore it is advisable to reduce nitrogen input for cultivation without compromising quality and yields. Copyright © 2007 Society of Chemical Industry     

Aroma compounds and sensory characteristics as biomarkers of quality of differently processed Tunisian virgin olive oils

The influence of the extraction system (continuous vs. discontinuous) and the degree of freshness of olives on the chemical composition and the quality of Chemlali and Chétoui virgin olive oil has been studied. Analytical data mainly concerning the volatile and sensory profiles revealed statistically significant differences in relation to the extraction system. All quality indices and sensory characteristics showed statistically significant differences associated with the degree of freshness of fruits. These results further confirm the general consensus that volatile compounds can be very useful as biomarkers of the quality of virgin olive oil and show correlations with the sensory characteristics.     

Diabetes in urban African Americans. V. Use of discussion groups to identify barriers to dietary therapy among low-income individuals with non-insulin-dependent diabetes mellitus

The purpose of the present study is the presentation of the available literature on obesity in Greece. The heterogeneity of design, small sample size and limited number of studies conducted, complicates the delineation of definite trends. Nevertheless, the existing literature appears to point at a high prevalence of obesity among Greek children. Childhood obesity, may partly be accounted for by the over-protection and forced feeding by Greek parents. With regard to the incidence of obesity among Greek adolescents, studies have yielded controversial results. On the other hand, the existing evidence appears to indicate a high prevalence of obesity among Greek adults and the elderly, particularly those above 30 years of age. In contrast to the females, males appear to be characterised by central obesity. These observations highlight a need for primary prevention measures.     

Rate evolution of benzonitrile nitration under heterogeneous conditions

The development of the nitration process in heterogeneous mixtures of benzonitrile and mixed acids of different compositions is followed in a batch stirred isothermal reactor. Preliminary evaluation of the distribution of the chemical species between the organic and acid phases allows mathematical modelling of benzonitrile nitration under heterogeneous conditions to be achieved on the basis of the previously assessed homogeneous nitration kinetics.     

Synbiotic potential of fresh cream cheese supplemented with inulin and Lactobacillus paracasei in co-culture with Streptococcus thermophilus

The influence of the addition of Lactobacillus paracasei and Streptococcus thermophilus on the fructan content at the beginning and at the end of storage at 4 ± 1 °C of a potentially synbiotic fresh cream cheese manufactured with inulin was investigated. Three cheese-making trials were prepared, all supplemented with a lactic culture of S. thermophilus (T1, T2 and T3). L. paracasei subsp. paracasei was added in T1 and T2. Inulin was added in T2 and the fructan content was measured after 1 and 21 days of storage. Samples of T2 possessed similar mean concentrations of fructans after 1 and 21 days of storage, 7.32% and 7.27%, respectively, and no significant difference was observed. These results indicated that the metabolism of starter and probiotic bacteria did not degrade the fructans present in those cheeses. Additionally, synbiotic cheeses possessed a fructan content higher than 7 g per 100 g, sufficient to confer prebiotic potential during the entire storage period of these products.     

A Technique to Analytically Formulate and to Solve the 2-Dimensional Constrained Trajectory Planning Problem for a Mobile Robot

A new technique for trajectory planning of a mobile robot in a two-dimensional space is presented in this paper. The main concept is to use a special representation of the robot trajectory, namely a parametric curve consisting in a sum of harmonics (sine and cosine functions), and to apply an optimization method to solve the trajectory planning problem for the parameters (i.e., the coefficients) appearing in the sum of harmonics. This type of curve has very nice features with respect to smoothness and continuity of derivatives, of whatever order. Moreover, its analytical expression is available in closed form and is very suitable for both symbolic and numerical computation. This enables one to easily take into account kinematic and dynamic constraints set on the robot motion. Namely, non-holonomic constraints on the robot kinematics as well as requirements on the trajectory curvature can be expressed in closed form, and act as input data for the trajectory planning algorithm. Moreover, obstacle avoidance can be performed by expressing the obstacle boundaries by means of parametric curves as well. Once the expressions of the trajectory and of the constraints have been set, the trajectory planning problem can be formulated as a standard mathematical problem of constrained optimization, which can be solved by any adequate numerical method. The results of several simulations are also reported in the paper to show the effectiveness of the proposed technique to generate trajectories which meet all requirements relative to kinematic and dynamic constraints, as well as to obstacle avoidance.