170,735 research outputs found
Heating, ventilation and air conditioning of a manufacturing hall
No full textDiplomsko delo predstavlja problem prezračevanja in klimatizacije v proizvodni hali, v kateri je zaradi pridobitve novih obdelovalnih centrov sistem prezračevanja potreben posodobitve. V prvem delu predstavimo pomembne parametre in sestavne dele centralnega sistema, nato se lotimo preračuna toplotnih dobitkov zaradi transmisije in sevanja ter notranjih toplotnih dobitkov zaradi obratovanja strojev in emisije toplote delavcev v prostoru. Preračun hladilne obremenitve in izbira klimata z adiabatnim hlapilnim hlajenjem kažeta, da ob izbiri notranjih pogojev 26 °C in 62 % RV razvlaževanje ni potrebno. V tem primeru za hlajenje potrebujemo 39,39 kW hladilne moči. Zaradi rekuperatorja in adiabatnega hlajenja potrebujemo za prezračevanje in hlajenje le 15 kW električne moči.The diploma represents a problem of ventilation and air conditioning of an expanding machining and production hall. In the first part we discuss important parameters and components of a central ventilation and air conditioning system, then we tackle heat gain calculations based on heat transmission, solar gain and internal heat gains caused by operating machinery and heat emission from workers. Heating load calculation and our choice of using an adiabatic evaporative cooling air handling unit, show us that with internal design conditions of 26 °C and 62 % RH, dehumidification is not necessary. In this instance we need 39,39 kW of cooling capacity. Because of our use of a heat exchanger and adiabatic evaporative cooling, we need 15 kW of electricity for cooling and ventilation combined
The influence of common ions on the conductivity of electrolytic mixtures
No full textS konduktometrično metodo smo v termostatirani celici merili vpliv iona na prevodnost elektrolitov pri 25℃. Za merjenje prevodnosti smo pripravili raztopine NaCl, KCl in NaNO3 s koncentacijo od 0,001 do 0,01 mol/L. Mešanice soli smo pripravili tako, da je bila skupna koncentracija vedno 0,01 mol/L. Spreminjali smo sestavo mešanic in merili spremembe prevodnosti. V raztopini NaCl in KCl smo preučevali vpliv skupnega aniona, v NaCl in NaNO3 vpliv skupnega kationa, v mešanici KCl in NaNO3 pa ni skupnega iona, ki bi vplival na skupno prevodnost.
S pomočjo grafov čistih elektrolitov smo potrdili Kohlrausch-ev zakon. Molske prevodnosti mešanic se gibljejo med vrednostmi čistih raztopin in so odvisne od sestave elektrolitske mešanice in od gibljivosti skupnih ionov.Using the conductometric method, the ion influence on the electrolyte conductivity at 25°C was measured in a thermostated cell. To measure the conductivity, solutions of NaCl, KCl and NaNO3 were prepared with a concentration of 0.001 to 0.01 mol / L. The salt mixtures were prepared in such a way that the total concentration was always 0.01 mol / L. We changed the composition of the mixtures and measured the changes in conductivity. We studied the effect of the common anions in the NaCl and KCl solution, and the effect of the common cations in the NaCl and NaNO3 solution. There were no common ions in the KCl and NaNO3 mixture that would affect total conductivity.
Using the graphs of pure electrolytes we confirmed Kohlrausch\u27s law. The molar conductivity of the mixtures varies between the values of the pure solutions and depends on the composition of the electrolytic mixture and the mobility of the common ions
Home-based Functional Electrical Stimulation rescues permanently denervated muscles in paraplegic patients with complete lower motor neuron lesion.
No full textNeurorehabil Neural Repair. 2010 Oct;24(8):709-21. Epub 2010 May 11.
Home-based functional electrical stimulation rescues permanently denervated muscles in paraplegic patients with complete lower motor neuron lesion.
Kern H, Carraro U, Adami N, Biral D, Hofer C, Forstner C, Mödlin M, Vogelauer M, Pond A, Boncompagni S, Paolini C, Mayr W, Protasi F, Zampieri S.
Source
Ludwig Boltzmann Institute of Electrostimulation and Physical Rehabilitation, Vienna, Austria.
Abstract
BACKGROUND:
Spinal cord injury causes muscle wasting and loss of function, which are especially severe after complete and permanent damage to lower motor neurons. In a previous cross-sectional study, long-standing denervated muscles were rescued by home-based functional electrical stimulation (h-bFES) training.
OBJECTIVE:
To confirm results by a 2-year longitudinal prospective study of 25 patients with complete conus/cauda equina lesions.
METHODS:
Denervated leg muscles were stimulated by h-bFES using a custom-designed stimulator and large surface electrodes. Muscle mass, force, and structure were determined before and after 2 years of h-bFES using computed tomography, measurements of knee torque during stimulation, and muscle biopsies analyzed by histology and electron microscopy.
RESULTS:
Twenty of 25 patients completed the 2-year h-bFES program, which resulted in (a) a 35% cross-sectional increase in area of the quadriceps muscle from 28.2 ± 8.1 to 38.1 ± 12.7 cm(2) (P < .001), a 75% increase in mean diameter of muscle fibers from 16.6 ± 14.3 to 29.1 ± 23.3 μm (P < .001), and improvements of the ultrastructural organization of contractile material; and (b) a 1187% increase in force output during electrical stimulation from 0.8 ± 1.3 to 10.3 ± 8.1 N m (P < .001). The recovery of quadriceps force was sufficient to allow 25% of the subjects to perform FES-assisted stand-up exercises.
CONCLUSIONS:
Home-based FES of denervated muscle is an effective home therapy that results in rescue of muscle mass and tetanic contractility. Important immediate benefits for the patients are the improved cosmetic appearance of lower extremities and the enhanced cushioning effect for seating.
PMID:
20460493
[PubMed - indexed for MEDLINE
New approach for the synthesis of [F-18]fluoroethyltyrosine for cancer imaging: Simple, fast, and high yielding automated synthesis
No full textO-(2-[F-18]fluoroethyl)-L-tyrosine ([(18)]FET) is one of the first F-18-labeled amino acids for imaging amino acid metabolism in tumors. This tracer overcomes the disadvantages of [F-18]fluorodeoxyglucose, [F-18]FDG, and [C-11]methionine, [C-11]MET. Nevertheless, the various synthetic methods providing F-18[FET]exhibit a big disadvantage concerning the necessity of two purification steps during the synthesis including HPLC purification, which causes difficulties in the automation, moderate yields, and long synthesis times >60 min. A new approach for the synthesis of [F-18]FET is developed starting from 2-bromoethyl triflate as precursor. After optimization of the synthesis parameters including the distillation step of [F-18]-FCH2CH2Br combined with the final purification of [F-18]FET using a simple solid phase extraction instead of an HPLC run the synthesis [F-18]FET could be significantly simplified, shortened, and improved. The radiochemical yield (RCY) was about 45% (not decay corrected and calculated relative to [F-18]F activity that was delivered from the cyclotron). Synthesis time was only 35 min from the end of bombardment (EOB) and the radiochemical purity was >99% at the end of synthesis (EOS). Thus, this simplified synthesis for [F-18]FET offers a very good option for routine clinical use. (C) 2009 Elsevier Ltd. All rights reserved
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Electrical stimulation of denervated muscles: first results of a clinical study
No full textTo evaluate the effects of electrical stimulation on denervated muscles in spinal cord injured humans, the EU Project RISE was started in 2001. The aims of this project are: to design and build sufficient stimulators; to develop stimulation protocols by means of mathematical models, animal experiments, and practice in humans with denervated lower limbs; to develop examination methods and devices for evaluation of electrical stimulation training effects; and to acquire basic scientific knowledge on denervated and stimulated denervated muscle. In the clinical study 27 spinal cord injured individuals were included, furthermore 13 pilot patients participated. After a series of initial examinations they underwent an electrical stimulation program for their denervated lower limb muscles. Some of the patients have already follow up examinations. A marked increase of muscle mass and quality was observed, the trophic situation of the denervated lower limbs had improved obviously
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
A Multidisciplinary Perspective on Person-Environment Fit: Relevance, Measurement, and Future Directions
No full textKandler C, Kühn S, Mönkediek B, Forstner AJ, Bleidorn W. A Multidisciplinary Perspective on Person-Environment Fit: Relevance, Measurement, and Future Directions. Current Directions in Psychological Science . 2024.Environments shape people, and at the same time, people are attracted to environments that fit their characteristics because fit facilitates the achievement of people's desired life outcomes, such as relationship satisfaction, work success, and well-being. In this article, we outline how persons and environments can fit, the relevance of fit and misfit for different life outcomes, and the benefits and pitfalls of different (mis)fit measures. We propose three directions for future research: (a) the use of both subjective and objective (mis)fit measures; (b) the consideration of complex dynamics between person and environment characteristics via pathways through multiple biological, experiential, behavioral, and social layers across the life span; and (c) the integration of insights from different disciplines, including psychology, sociology, neuroscience, and genetics, to move the field forward
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
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