Turbulent Motion of Liquids in Hydraulic Resistances with a Linear Cylindrical Slide-Valve.

We analyze the motion of viscous and incompressible liquids in the annular space of controllable hydraulic resistances with a cylindrical linear slide-valve. This theoretical study focuses on the turbulent and steady-state motion regimes. The hydraulic resistances mentioned above are the most frequent type of hydraulic resistances used in hydraulic actuators and automation systems. To study the liquids' motion in the controllable hydraulic resistances with a linear cylindrical slide-valve, the report proposes an original analytic method. This study can similarly be applied to any other type of hydraulic resistance. Another purpose of this study is to determine certain mathematical relationships useful to approach the theoretical functionality of hydraulic resistances with magnetic controllable fluids as incompressible fluids in the presence of a controllable magnetic field. In this report, we established general analytic equations to calculate (i) velocity and pressure distributions, (ii) average velocity, (iii) volume flow rate of the liquid, (iv) pressures difference, and (v) radial clearance.

Fallout radionuclide-based techniques for assessing the impact of soil conservation measures on erosion control and soil quality: an overview of the main lessons learnt under an FAO/IAEA Coordinated Research Project.

This paper summarizes key findings and identifies the main lessons learnt from a 5-year (2002-2008) coordinated research project (CRP) on "Assessing the effectiveness of soil conservation measures for sustainable watershed management and crop production using fallout radionuclides" (D1.50.08), organized and funded by the International Atomic Energy Agency through the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture. The project brought together nineteen participants, from Australia, Austria, Brazil, Canada, Chile, China, Japan, Morocco, Pakistan, Poland, Romania, Russian Federation, Turkey, United Kingdom, United States of America and Vietnam, involved in the use of nuclear techniques and, more particularly, fallout radionuclides (FRN) to assess the relative impacts of different soil conservation measures on soil erosion and land productivity. The overall objective of the CRP was to develop improved land use and management strategies for sustainable watershed management through effective soil erosion control practices, by the use of ¹³7Cs (half-life of 30.2 years), ²¹°Pb(ex) (half-life of 22.3 years) and 7Be (half-life of 53.4 days) for measuring soil erosion over several spatial and temporal scales. The environmental conditions under which the different research teams applied the tools based on the use of fallout radionuclides varied considerably--a variety of climates, soils, topographies and land uses. Nevertheless, the achievements of the CRP, as reflected in this overview paper, demonstrate that fallout radionuclide-based techniques are powerful tools to assess soil erosion/deposition at several spatial and temporal scales in a wide range of environments, and offer potential to monitor soil quality. The success of the CRP has stimulated an interest in many IAEA Member States in the use of these methodologies to identify factors and practices that can enhance sustainable agriculture and minimize land degradation.

[Economic evaluation of telehomecare in chronic lung diseases]. / Valutazione economica del telemonitoraggio domiciliare in malattie polmonari croniche.

OBJECTIVES: We attempted to quantify the cost-effectiveness ratio in telemonitoring lung function of patients affected by Cystic Fibrosis (CF). MATERIALS AND METHODS: We examined the costs of Telehomecare (THC) in the follow-up of CF patients. We considered the failed hospitalizations as incomes. A standardized questionnaire was submitted by e-mail to verify the patient satisfaction and expectation levels. We studied 3 groups of patients: a) 17 CF patients in THC; b) 28 CF patients not followed by THC and c) 28 non-CF patients affected by chronic diseases and not followed by THC. Some parameters with no market value were evaluated using "willingness to pay" (WTP). RESULTS: An annual saving of €.5241 was calculated for single FC patient followed by THC. The WTP analysis showed that patients affected by chronic diseases expected very much from new technologies. CONCLUSIONS: The THC use in CF shows several advantages as fewer hospitalization and economical saving in a general trend of limited economical resources. Further studies are needed to confirm our data.

Iron oxide-based nanoparticles with different mean sizes obtained by the laser pyrolysis: structural and magnetic properties.

Nano-sized iron oxide-based particles have been directly synthesized by the laser induced pyrolysis of a mixture containing iron pentacarbonyl/air (as oxidizer)/ethylene (as sensitizer). In this paper we further demonstrate the possibility to vary the chemical composition and the nanoparticle dimensions of the iron oxide-based materials by handling the oxidation procedure in the frame of the laser pyrolysis process. Thus, nanoparticles with major maghemite/magnetite content may change composition into mixtures with variable amounts of three components: major gamma-Fe2O3/Fe3O4 iron oxide, metallic Fe and cementite Fe3C. By X-ray diffraction (XRD) it is found that the relative proportion of these phases differs in function of the reaction temperature (laser power). As revealed by transmission electron microscopy (TEM), mean particle sizes between about 4 nm and 6 nm and between about 9 and 11 nm may be prepared by varying the oxidation procedure and the laser power, respectively. By the controlled heating of samples (maximum temperature 185 degrees C), increased crystallinity for the gamma-Fe2O3/Fe3O4 oxide phase was found as well as an increase of the mean particle diameters. The examination of the magnetization curves for samples obtained for different laser powers indicates notable differences in the magnetic behavior and parameters. The temperature dependent Mossbauer measurements confirm the formation of larger particles at higher laser power densities as well as the presence of inter-particle magnetic interactions. On this basis, the estimation of phase composition for the different representative samples is given.

U4O9: atoms in general sites giving the hkl extinctions of special sites.

In U4O9, most of the atoms are in general 48-fold [48(e)] sites of the space group I43d and yet the hkl reflections obey the extinction rules for atoms occupying special 12-fold [12(b)] sites. An explanation is given for this effect, which can be generalized to any space group.

Maximum-likelihood reconstruction with ordered subsets in bone SPECT.

UNLABELLED: This study was aimed at determining whether the ordered-subset expectation maximum (OSEM) is more effective than filtered backprojection (FBP) for bone SPECT in the routine clinical context. METHODS: Fifty-seven consecutive bone SPECT studies were analyzed. They included pelvic and lumbar spine, thoracolumbar spine, head and neck, feet and shoulders. A 64-projection SPECT study was acquired over 360 degrees by single-head cameras 2-3 h after the injection of 750 MBq 99mTc-methylene diphosphonate. Three observers compared the OSEM and FBP reconstructed images. RESULTS: Streak artifacts, always present with FBP, were rarely generated with the OSEM. When present (n = 24), artifacts associated with negative values near hyperactivities in FBP were not generated with the OSEM in 67% of the cases (n = 16), permitting a satisfactory interpretation of these regions. In half of the other cases (17%, n = 4/24), interpretation was precluded. In only one case did the three observers agree that more hyperactivities were seen with the OSEM. Ninety-six percent of the OSEM pictures were superior or equal to FBP for anatomic resolution and were clearly better in 12% of the cases. The extent of the lesion with the OSEM seemed better or equally defined in 96% and clearly better in 14% of the cases. The low-activity regions were better or equally visualized in all cases and were clearly better seen in 23% of the cases. The quality of the pictures was found to be better or superior with the OSEM in 98% of the cases and definitely better in 65% of the cases. CONCLUSION: Replacement of FBP by the OSEM in bone SPECT would be beneficial to clinical practice.

The stimulation of fibronectin synthesis by high peak power electromagnetic energy (Diapulse).

The effect of Diapulse therapy (pulsed electromagnetic energy of 27.12 MHz frequency) on post-operative wound healing and plasma fibronectin concentration is investigated. Patients treated with Diapulse, locally and over hepatic area present higher fibronectin levels starting 3d day after surgery. These higher values correlate well with a clear improvement of wound healing processes.

Positive 67Ga-citrate scintigraphy: vertebral, satellite lymph node and gallbladder foci in a case of gastroenteritis with salmonella.

We report a case of salmonella gastroenteritis with recurrent fever and sepsis, slight transient lumbar pain and positive 67Ga-citrate scintigraphy. The 67Ga scan made a major contribution to the positive diagnosis of a subclinical spondylodiscit and to the correct treatment leading to the disappearance of the infectious foci.

[Prevention of postsurgical thromboembolism with small doses of heparin]. / Profilaxia bolii tromboembolice postoperatorii cu doze mici de heparina.

The study includes 390 patients of different age, operated for various conditions during the last quarter of 1975, and systematically treated post operatively with heparin (the cases in which heparin was contraindicated were not included). None of the patients developed signs of thromboembolism after the operation. The drawbacks of the method are virtually inexistent as compared to the gravity of postoperative thrombolic complications. A further study included 1708 operated patients of whom 223 (13.0%) received the heparin treatment and 1485 (87.0%) did not. There was no thrombolic-embolic complication in the former lot and 12 cases (0.8%) in the latter. Three of 15 patients (20%) in whom the postoperative heparin treatment was interrupted immediately or very soon, developed thromboembolism. The method is efficient provided it is applied after the operation up to complete mobilization of the patient. The method is readily applicable, there is no risk and haemostasis is insured.

[Effect of pulmonary ventilation capacity on the postoperative course in thoraco-pulmonary surgery]. / Influenta posibilitatilor de ventilatie pulmonara asupra evolutiei postoperatorii in chirurgia toracopulmonara

The authors made a statistical investigation of the postoperative evolution in thoraco-pulmonary surgery and found diffuse hemorrhage, alterations in the evolution of wound healing, failures, higher death-rate and longer hospitalization, higher incidences being noted, inverse relationship with the pulmonary ventilation. These phenomena are attributed to the respiration disturbances, without patient clinical manifestations. The utility of the global spyrogram is acknowledged, when there are no other dysfunctions. The authors consider as lower limits of the spyrographic data, under which the surgical indications are fraught with too high a risk, values between 50 and 60% of the theoretical ones.