940 resultados para FNDC clipping on-line
Resumo:
A flow system coupled to a tungsten coil atomizer in an atomic absorption spectrometer (TCA-AAS) was developed for As(III) determination in waters, by extraction with sodium diethyldithiocarbamate (NaDDTC) as complexing agent, and by sorption of the As(III)-DDTC complex in a micro-column filled with 5 mg C18 reversed phase (10 µL dry sorbent), followed by elution with ethanol. A complete pre-concentration/elution cycle took 208 s, with 30 s sample load time (1.7 mL) and 4 s elution time (71 µL). The interface and software for the synchronous control of two peristaltic pumps (RUN/ STOP), an autosampler arm, seven solenoid valves, one injection valve, the electrothermal atomizer and the spectrometer Read function were constructed. The system was characterized and validated by analytical recovery studies performed both in synthetic solutions and in natural waters. Using a 30 s pre-concentration period, the working curve was linear between 0.25 and 6.0 µg L-1 (r = 0.9976), the retention efficiency was 94±1% (6.0 µg L-1), and the pre-concentration coefficient was 28.9. The characteristic mass was 58 pg, the mean repeatability (expressed as the variation coefficient) was 3.4% (n=5), the detection limit was 0.058 µg L-1 (4.1 pg in 71 µL of eluate injected into the coil), and the mean analytical recovery in natural waters was 92.6 ± 9.5 % (n=15). The procedure is simple, economic, less prone to sample loss and contamination and the useful lifetime of the micro-column was between 200-300 pre-concentration cycles.
Resumo:
Levoluci que ha experimentat la societat, les grans ciutats, la industrialitzaci i molts altres factors han modificat lestil de vida de les persones accentuant-ne, irremediablement, el sedentarisme i labstinncia de realitzar exercici fsic. La prctica esportiva i/o dexercici fsic realitzada sota les condicions recomanades pels professionals, s beneficiosa per millorar el nivell de salut o mantenir-lo en tot el possible, ja que provoca modificacions beneficioses sobre el metabolisme, el sistema cardiovascular i laparell locomotor. Lamentablement, lhbit de realitzar exercici fsic no s com en totes les persones, ja sigui per lestil de vida que genera incompatibilitats dhoraris amb la feina, fills i familiars o b per mandra o desgana dhaver daprofitar aquelles estones de temps lliure per dedicar-los al culte del cos i de la salut. Els efectes negatius que suposa una modalitat de vida sedentria per a la salut sn notablement elevats, amb la qual cosa, cal buscar sistemes per augmentar l inters de la poblaci per la prctica de lesport i lactivitat fsica. La creaci daquest projecte neix de la idea dunir el fet denginyar un mtode per incrementar linters de les persones per lexercici fsic amb els avenos tecnolgics que shan realitzat aquesta ltima dcada relacionats amb el desenvolupament web i multimdia. A grans trets, la idea general daquest projecte es basa en el cas dun gimns real i en actiu, amb necessitat de crear un portal web que serveixi alhora de pgina web informativa i deina de gesti acadmica del centre proporcionant certes funcionalitats als clients tot presentant-los una nova modalitat de realitzar exercici fsic dirigit: realitzar-lo des de casa. Per desenvolupar tot el sistema informtic que ho dur a terme, desprs de realitzar una recerca, anlisi i elecci de les eines mitjanant les quals poder-ho realitzar, sha optat per crear lentorn web mitjanant els llenguatges HTML i PHP en combinaci amb els fulls destil CSS. Pel que fa a lentorn de desenvolupament, sha utilitzat Notepad++ i com a entorn de proves, WAMP Server. Per ltim, pel que fa a la transmissi del contingut multimdia (vdeos de les sessions dactivitats) sha utilitzat Flash Media Interactive Server en combinaci de Flash Media Live Encoder per codificar-ne el contingut. Lusuari final, des de qualsevol punt del planeta, podr realitzar (sempre i quan disposi del temps i el material necessari i una connexi a Internet) en temps real i en directe les classes dirigides que es realitzen al centre. Tanmateix, tamb sha desenvolupat una botiga virtual on qualsevol persona podr comprar-hi, entre daltres coses relacionades amb la prctica de lexercici fsic, tot el material necessari per realitzar qualsevol de les activitats que simparteixen al gimns i ho rebr cmodament a casa. Aprofitar unes circumstncies econmiques adverses per generar una nova manera de captar clients proporcionant-los una alternativa econmica, diferent, nova i original danar al gimns. Temps de crisis, temps doportunitats. Aquesta s la moralitat que pretn donar aquest projecte.
Resumo:
En aquests moments, el mercat no es troba en una bona situaci, per aquest motiu les empreses han de buscar noves maneres de crixer, expandir-se i noves formes dinteractuar amb els clients. La idea original daquest projecte sorgeix de la necessitat de disposar duna manera diferent de promocionar-se i oferir nous serveis a travs dinternet mitjanant una pgina web. Degut a la situaci actual, el preu s un aspecte molt important i influent a lhora de realitzar una obra. Per aquest motiu es va pensar que seria molt interessant que el client pogus demanar de forma fcil i rpida un pressupost, i a linstant tingus un preu orientatiu del que li pot costar la obra. Daquesta manera linteressat sestalvia i agilitza molts passos previs abans de comenar una obra. Desprs danalitzar quina era la millor manera de portar a terme el projecte informtic, sha determinat que la pgina web es desenvolupar utilitzant els llenguatges HTML i PHP combinant-lo amb el framework CodeIgniter. El disseny de la web es realitzar mitjanant fulles destil CSS conjuntament amb el framework BootStrap. Per realitzar laplicaci web que realitza els pressupostos sutilitzar AJAX i jQuery perqu daquesta manera el procs sigui dinmic. Lentorn de desenvolupament escollit s el NetBeans i per provar el projecte sutilitza el XAMPP. Un usuari noms necessitar un navegador i connexi a internet per fer servir totes les funcions de la web. Podr realitzar pressupostos, concertar visites, contactar i per suposat veure tota la part informativa de la pgina
Resumo:
A liquid chromatography-tandem mass spectrometry method with atmospheric pressure chemical ionization (LC-APCI/MS/MS) was validated for the determination of etoricoxib in human plasma using antipyrin as internal standard, followed by on-line solid-phase extraction. The method was performed on a Luna C18 column and the mobile phase consisted of acetonitrile:water (95:5, v/v)/ammonium acetate (pH 4.0; 10 mM), run at a flow rate of 0.6 mL/min. The method was linear in the range of 1-5000 ng/mL (r>0.99). The lower limit of quantitation was 1 ng/mL. The recoveries were within 93.72-96.18%. Moreover, method validation demonstrated acceptable results for the precision, accuracy and stability studies.
Resumo:
A simple and sensitive on-line flow injection system for determination of zinc with FAAS has been described. The method is based on the separation and preconcentration of zinc on a microcolumn of immobilized Alizarin Red S on alumina. The adsorbed analyte is then eluted with 250 L of nitric acid (1 mol L-1) and is transported to flame atomic absorption spectrometer for quantification. The effect of pH, sample and eluent flow rates and presence of various cations and anions on the retention of zinc was investigated. The sorption of zinc was quantitative in the pH range of 5.5-8.5. For a sample volume of 25 mL an enrichment factor of 144 and a detection limit (3S) of 0.2 g L-1 was obtained. The precision (RSD, n=7) was 3.0% at the 20 g L-1 level. The developed system was successfully applied to the determination of zinc in water samples, hair, urine and saliva.
Resumo:
The present work purposes the preparation of a silica gel sorbent organically modified with 2-aminoethyl-3-aminobutylmethyldimethoxysilane (AAMDMS) and imprinted with Cu2+ ions by means surface imprinting technique and its use for selective on-line sorbent preconcentration of Cu2+ ions with further UV-VIS spectrophotometric determination by flow injection analysis. The Cu2+-imprinted silica gel, when compared with non imprinted silica gel and silica gel, showed from the binary mixture of Cu2+/Ni2+ relative selectivity coefficient (k') of 6.84 and 5.43 and 6.64 and 19.83 for the mixture Cu2+/Pb2+, thus demonstrating higher selectivity of Cu2+-imprinted silica gel towards Cu2+ ions. Under optimized condition, the on-line preconcentration method provided detection limit of 3.4 μg L-1 and linear range ranging from 30.0 up to 300.0 μg L-1 (r = 0.995). The accuracy of method was successfully assessed by analyzing different kind of spiked water samples with recovery values ranging from 92.2 up to 103.0%.
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A portable microcontrolled system is proposed to monitor conductivity, temperature and pH in on-line, in situ and remote way from a water reservoir faraway 200 m. The system comprises two modules: one for data reception (located in laboratory) and another for data acquisition/transmission (located near water reservoir). It uses a microcontroller and a transceiver to remote data transmission/reception by radio frequency. Variations of water parameters were simultaneously monitored without interruption during a period of ten hours with a relative error about 4.0 %. The developed system showed simple, stable, accurate, robust and low-cost to determine parameters of water in field.
Resumo:
The focus in this thesis is to study both technical and economical possibilities of novel on-line condition monitoring techniques in underground low voltage distribution cable networks. This thesis consists of literature study about fault progression mechanisms in modern low voltage cables, laboratory measurements to determine the base and restrictions of novel on-line condition monitoring methods, and economic evaluation, based on fault statistics and information gathered from Finnish distribution system operators. This thesis is closely related to masters thesis Channel Estimation and On-line Diagnosis of LV Distribution Cabling, which focuses more on the actual condition monitoring methods and signal theory behind them.
Resumo:
OBJETIVO: Foi testar a validade e a confiabilidade de uma verso on-line do Female Sexual Function Index (FSFI). MTODOS: Uma verso on-line do FSFI foi comparada verso tradicional, em papel. Para tanto, estudantes de Fisioterapia de trs cidades foram alocadas randomicamente em dois grupos - G-pp/ol (n=126) e G-ol/pp (n=147). As mulheres do G-pp/ol responderam ao FSFI do modo tradicional, em papel e caneta, enquanto o G-ol/pp respondeu a uma verso on-line do mesmo questionrio. Aps 15 dias de intervalo, houve nova coleta, quando o G-pp/ol respondeu a verso on-line enquanto o G-ol/pp respondeu no papel. Todos os dados foram transportados para o software estatstico SPSS. Diferenas demogrficas entre os dois grupos foram reveladas pelo teste t de Student ou pelo teste exato de Fischer (IC95%; p>0,05). A associao e a correlao entre as respostas entre G-pp/ol e G-ol/pp durante cada coleta foram acessadas pelo teste t e o coeficiente de Pearson. Estratgia idntica foi utilizada para as comparaes intragrupo. RESULTADOS: Um total de 273 mulheres participou do estudo e 28 (10,2%) desistiram da segunda coleta. No houve diferenas demogrficas entre os grupos. Houve associao entre 15 das 19 questes do FSFI entre os dois grupos, tanto no teste quanto no reteste. A anlise intragrupo revelou que todas as questes e os escores do FSFI estiveram associados, mas fracamente correlacionados para um mesmo grupo durante as duas coletas. CONCLUSO: A verso on-line do FSFI apresentou validade e confiabilidade aceitveis quando comparada verso em papel, o que pode justificar a opo por essa modalidade, especialmente em estudos envolvendo sexualidade.
Resumo:
The purpose of this research was to provide a deeper insight into the consequences of electronic human resource management (e-HRM) for line managers. The consequences are viewed as used information system (IS) potentials pertaining to the moderate voluntaristic category of consequences. Due to the need to contextualize the research and draw on line managers personal experiences, a qualitative approach in a case study setting was selected. The empirical part of the research is loosely based on literature on HRM and e-HRM and it was conducted in an industrial private sector company. In this thesis, method triangulation was utilized, as nine semi-structured interviews, conducted in a European setting, created the main method for data collection and analysis. Other complementary data such as HRM documentation and statistics of e-HRM system usage were utilized as background information to help to put the results into context. E-HRM has partly been taken into use in the case study company. Line managers tend to use e-HRM when a particular task requires it, but they are not familiar with all the features and possibilities which e-HRM has to offer. The advantages of e-HRM are in line with the companys goals. The advantages are e.g. an transparency of data, process consistency, and having an efficient and easy-to-use tool at ones disposal. However, several unintended, even contradictory, and mainly negative outcomes can also be identified, such as over-complicated processes, in-security in use of the tool, and the lack of co-operation with HR professionals. The use of e-HRM and managers perceptions regarding e-HRM affect the way in which managers perceive the consequences of e-HRM on their work. Overall, the consequences of e-HRM are divergent, even contradictory. The managers who considered e-HRM mostly beneficial to their work found that e-HRM affects their work by providing information and increasing efficiency. Those managers who mostly perceived challenges in e-HRM did not think that e-HRM had affected their role or their work. Even though the perceptions regarding e-HRM and its consequences might reflect the strategies, the distribution of work, and the ways of working in all HRM in general and cant be generalized as such, this research contributed to the field of e-HRM and it provides new perspectives to e-HRM in the case study organization and in the academic field in general.
Resumo:
Biopolttoaineet ovat trke energianlhde suomalaisessa energiantuotannossa. Biopoltto- aineille on kuitenkin ominaista laadun vaihtelevuus. Yksi trkeimmist laatutekijist on kosteus, joka vaikuttaa mys polttoaineen energiasisltn. Laatutekijt puolestaan vai- kuttavat polttoaineksittelyyn, polttoprosessiin ja koko laitoksen hytysuhteeseen. Tmn tyn tarkoituksena oli tutkia voisiko biopolttoaineiden online-laadunmittaus tuoda lisarvoa energiantuotantolaitokselle. Esimerkkin kytettiin yht online-laadunmittaus- sovellusta, InrayFuel-rntgenmittausjrjestelm. Sill voidaan seurata biopolttoaineiden kosteutta ja polttoaineen sisltmi vierasaineita. Tyss on laadittu kustannusanalyysi, jolla pyritn selvittmn, onko nykyisen kertaluontoisen mittausmenetelmn korvaami- nen jatkuvatoimisella kannattavaa. Esimerkkilaitoksena on Etel-Savon Energian Pur- sialan voimalaitos, jossa rntgenmittausjrjestelmn on testattu. Saatujen tulosten mukaan investoiminen esimerkkimittausjrjestelmn maksaisi itsens takaisin alle vuodessa. Kun laitoksella pystytn seuraamaan polttoaineen laatua jatkuva- toimisesti, laadunhallinta paranee ja sit kautta voidaan saavuttaa kustannussstj. Polt- toaineesta johtuvat hiritilanteet vhenevt, polttoaine on mahdollista optimoida edulli- semmaksi polton kannalta ja poltto-olosuhteita voidaan st paremmin, jolloin pstt vhenevt ja hytysuhde kasvaa. Tyss kytetty laskenta analysoi kuitenkin hyvin ylei- sell tasolla, sill kytss ei ollut laitoksen omaa taselaskentajrjestelm. Laskenta siis sislt paljon oletuksia. Tmn ja rohkaisevien tulosten vuoksi tutkimusta jatkuvatoimi- sen laadunmittauksen hydyist kannattaa tehd enemmn.
Resumo:
Valuable minerals can be recovered by using froth flotation. This is a widely used separation technique in mineral processing. In a flotation cell hydrophobic particles attach on air bubbles dispersed in the slurry and rise on the top of the cell. Valuable particles are made hydrophobic by adding collector chemicals in the slurry. With the help of a frother reagent a stable froth forms on the top of the cell and the froth with valuable minerals, i.e. the concentrate, can be removed for further processing. Normally the collector is dosed on the basis of the feed rate of the flotation circuit and the head grade of the valuable metal. However, also the mineral composition of the ore affects the consumption of the collector, i.e. how much is adsorbed on the mineral surfaces. Therefore it is worth monitoring the residual collector concentration in the flotation tailings. Excess usage of collector causes unnecessary costs and may even disturb the process. In the literature part of the Masters thesis the basics of flotation process and collector chemicals are introduced. Capillary electrophoresis (CE), an analytical technique suitable for detecting collector chemicals, is also reviewed. In the experimental part of the thesis the development of an on-line CE method for monitoring the concentration of collector chemicals in a flotation process and the results of a measurement campaign are presented. It was possible to determine the quality and quantity of collector chemicals in nickel flotation tailings at a concentrator plant with the developed on-line CE method. Sodium ethyl xanthate and sodium isopropyl xanthate residuals were found in the tailings and slight correlation between the measured concentrations and the dosage amounts could be seen.
Resumo:
A method using L-cysteine for the determination of arsenous acid (As(III)), arsenic acid (As(V)), monomethylarsonic acid (MMAA), and dimethylarsinic acid (DMAA) by hydride generation was demonstrated. The instrument used was a d.c. plasma atomic emission spectrometer (OCP-AES). Complete recovery was reported for As(III), As(V), and DMAA while 86% recovery was reported for MMAA. Detection limits were determined, as arsenic for the species listed previously, to be 1.2, 0.8, 1.1, and 1.0 ngemL-l, respectively. Precision values, at 50 ngemL-1 arsenic concentration, were f.80/0, 2.50/0, 2.6% and 2.6% relative standard deviation, respectively. The L-cysteine reagent was compared directly with the conventional hydride generation technique which uses a potassium iodide-hydrochloric acid medium. Recoveries using L-cysteine when compared with the conventional method provided the following results: similar recoveries were obtained for As(III), slightly better recoveries were obtained for As(V) and MMAA, and significantly better recoveries for DMAA. In addition, tall and sharp peak shapes were observed for all four species when using L-cysteine. The arsenic speciation method involved separation by ion exchange .. high perfonnance liquid chromatography (HPLC) with on-line hydride generation using the L.. cysteine reagent and measurement byOCP-AES. Total analysis time per sample was 12 min while the time between the start of subsequent runs was approximately 20 min. A binary . gradient elution program, which incorporated the following two eluents: 0.01 and 0.5 mM tri.. sodium citrate both containing 5% methanol (v/v) and both at a pH of approximately 9, was used during the separation by HPLC. Recoveries of the four species which were measured as peak area, and were normalized against As(III), were 880/0, 290/0, and 40% for DMAA, MMAA and As(V), respectively. Resolution factors between adjacent analyte peaks of As(III) and DMAA was 1.1; DMAA and MMAA was 1.3; and MMAA and As(V) was 8.6. During the arsenic speciation study, signals from the d.c. plasma optical system were measured using a new photon-signal integrating device. The_new photon integrator developed and built in this laboratory was based on a previously published design which was further modified to reflect current available hardware. This photon integrator was interfaced to a personal computer through an AID convertor. The .photon integrator has adjustable threshold settings and an adjustable post-gain device.
