917 resultados para Loading and unloading
Resumo:
The Road Rater is a dynamic deflection measuring apparatus for flexible base pavements. The Road Rater replaces the Benkelman Beam which was last used by the Iowa DOT in 1977. Road Rater test results correlate reasonably well (correlation coefficient = 0.83) with Benkelman Beam test data. The basic differences between the Road Rater and Benkelman Beam are as follows: 1. The Benkelman Beam uses a static 18,000 lb. load while the Road Rater uses a dynamic 800 to 2,000 lb. loading. 2. The Road Rater tests much faster and more economically than the Benkelman Beam. 3. The Road Rater better simulates a moving truck than the Benkelman Beam. The basic operating principle of the Road Rater is to impart a dynamic loading and measure the resultant movement of the pavement with velocity sensors. This data, when properly adjusted for temperature by use of a nomograph included in this report, can be used to determine pavement life expectancy and estimate overlay thickness required. Road Rater testing will be conducted in the spring, when pavements are in their weakest condition, until seasonal correction factors can be developed. The Road Rater does not have sufficient ram weight to effectively evaluate load carrying capacity of rigid pavements. All rigid pavements react similarly to Road Rater testing and generally deflect from 0.65 to 1.30 mils. Research will be contined to evaluate rigid pavements with the Road Rater, however. The Road Rater has proven to be a reliable, troublefree pavement evaluation machine. The deflection apparatus was originally front-mounted,but was rear-mounted during the winter of 1977-78. Since that time, van handling has greatly improved, and front suspension parts are no longer overstressed due to improper weight distribution.
Resumo:
Staff and Beaver Creeks are two tributaries of the Upper Iowa River (UIR). Additional acres that drain directly into the UIR bring the size of the project area to 41,328 acres. The goal of the project is to reduce sediment loading and excess nutrients from reaching the streams which ultimately reach the UIR. Staff/Beaver Water Quality Project initially received funding as part of the FY 2005 WSPF/319 grant application cycle. Tremendous progress has been accomplished towards the original goals of the project. Due to the large number of Best Management Practices (BMPs) installed and the continued high interest for those practices, more work remains to be done. The heavy rains received in 2008 caused severe erosion and has dramatically increased interest in conservation practices. A thorough watershed assessment was completed in the fall of 2008. Data from this assessment indicates additional work is needed. The initial grant funding will be exhausted within fiscal year 2009. Therefore, the Howard Soil and Water Conservation District is seeking 3 years of funding. The District believes interest in the water quality project is at an all time high and that with an additional three years of funding, even more progress can be achieved in reducing sediment delivery and excess nutrients to these priority streams.
Resumo:
Bridge deck expansion joints are used to allow for movement of the bridge deck due to thermal expansion, dynamics loading, and other factors. More recently, expansion joints have also been utilized to prevent the passage of winter de-icing chemicals and other corrosives applied to bridge decks from penetrating and damaging substructure components of the bridge. Expansion joints are often one of the first components of a bridge deck to fail and repairing or replacing expansion joints are essential to extending the life of any bridge. In the Phase I study, the research team focused on the current means and methods of repairing and replacing bridge deck expansion joints. Research team members visited with Iowa Department of Transportation (DOT) Bridge Crew Leaders to document methods of maintaining and repairing bridge deck expansion joints. Active joint replacement projects around Iowa were observed to document the means of replacing expansion joints that were beyond repair, as well as, to identify bottlenecks in the construction process that could be modified to decrease the length of expansion joint replacement projects. After maintenance and replacement strategies had been identified, a workshop was held at the Iowa State Institute for Transportation to develop ideas to better maintain and replace expansion joints. Maintenance strategies were included in the discussion as a way to extend the useful life of a joint, thus decreasing the number of joints replaced in a year and reducing the traffic disruptions.
Resumo:
The primary objective of this project was to determine the effect of bridge width on deck cracking in bridges. Other parameters, such as bridge skew, girder spacing and type, abutment type, pier type, and number of bridge spans, were also studied. To achieve the above objectives, one bridge was selected for live-load and long-term testing. The data obtained from both field tests were used to calibrate a three-dimensional (3D) finite element model (FEM). Three different types of loading—live loading, thermal loading, and shrinkage loading—were applied. The predicted crack pattern from the FEM was compared to the crack pattern from bridge inspection results. A parametric study was conducted using the calibrated FEM. The general conclusions/recommendations are as follows: -- Longitudinal and diagonal cracking in the deck near the abutment on an integral abutment bridge is due to the temperature differences between the abutment and the deck. Although not likely to induce cracking, shrinkage of the deck concrete may further exacerbate cracks developed from thermal effects. -- Based upon a limited review of bridges in the Iowa DOT inventory, it appears that, regardless of bridge width, longitudinal and diagonal cracks are prevalent in integral abutment bridges but not in bridges with stub abutments. -- The parametric study results show that bridge width and skew have minimal effect on the strain in the deck bridge resulting from restrained thermal expansion. -- Pier type, girder type, girder spacing, and number of spans also appear to have no influence on the level of restrained thermal expansion strain in the deck near the abutment.
Resumo:
Farmers Creek is a moderately flowing stream that winds through seventeen miles of central Jackson County, encompassing a watershed area of 30,590 acres. Due to nutrient loading and sedimentation, the stream was placed on Iowa’s 303(d) List of Impaired Waters in 2002. A three year grant project was initiated in January 2005 to reduce both sediment delivery and phosphorus levels by 40% in critical areas along the stream corridor. Over thirty-five BMP’s were started in the first nine months of this project. Funding through WIRB is being requested specifically for streambank stabilization and protection projects not covered by other cost-share programs. Innovative project designs and techniques will be installed and act as demonstration sites. Projects may include jetties, weirs, cedar revetments, cattle crossings, and fencing. To assist in excluding cattle from the stream, watering systems such as slingpumps, pasture pumps, or water rams will be installed, in conjunction with filter strips and riparian buffers.
Resumo:
Farmers Creek is a moderately flowing stream that winds through seventeen miles of central Jackson County, encompassing a watershed area of 30,590 acres. Due to nutrient loading and sedimentation, the stream was placed on Iowa’s 303(d) List of Impaired Waters in 2002. A three year grant project was initiated in January 2005 to reduce both sediment delivery and phosphorus levels by 40% in critical areas along the stream corridor. Over thirty-five BMP’s were started in the first nine months of this project. Funding through WIRB is being requested specifically for streambank stabilization and protection projects not covered by other cost-share programs. Innovative project designs and techniques will be installed and act as demonstration sites. Projects may include jetties, weirs, cedar revetments, cattle crossings, and fencing. To assist in excluding cattle from the stream, watering systems such as slingpumps, pasture pumps, or water rams will be installed, in conjunction with filter strips and riparian buffers.
Resumo:
Työn tavoitteena oli kehittää sohvakalusteita valmistavan yrityksen tuotannon- ja materiaalinohjausta. Tuotanto on sekä varasto-ohjautuvaa, että tilausohjautuvaa kokoonpanoa. Kehittämisessä pääpaino oli läpäisyaikojen lyhentämisellä molemmissa tuotantomuodoissa, vaihto-omaisuuden arvon alentamisessa sekä kriittisten materiaalien ohjauksen tehostamisessa. Työssä on ensin selvitetty tuotannon- ja materiaalin-ohjauksen teoriaa, tilaus-toimitus-prosessia ja tietojärjestelmiä osana tuotannonohjausta. Tavoitteena on ollut valita käytännössä hyvin toimivia ohjausmenettelyitä ja soveltaa niitä kohdeyrityksessä, jotta asetetut tavoitteet saavutettaisiin mahdollisimman nopealla aikataululla. Raporttien ja seurantatyökalujen kehittäminen tietojärjestelmässä on ensisijaisen tärkeää, että voidaan mitata tuloksia ja asettaa tavoitteita. Varastoinnin painopisteen siirtäminen valmistuotevarastosta puolivalmis-tasolle tulee toteuttaa kuluvan vuoden aikana. Avainsanoja läpäisyajan lyhentämisessä tilausohjautuvassa tuotannossa ovat nopea tilausten aloittaminen, turhien alkuvaiheiden poistaminen, nopea leikkuu, töiden visuaalinen ohjaaminen, sähköisten kotiinkutsumenettelyiden kehittäminen ja toimittajayhteistyö. Varasto-ohjautuvilla tuotteilla taas puolivalmisteet, imuohjausmenettelyt ainakin puolivalmisteiden tekemisen ohjauksessa, vedossuunnittelun ja hienokuormituksen yksinkertaistaminen ja luonnollisesti kaikki materiaalinohjausta parantavat toimenpiteet. Konsignaatiovarastojen käyttö päälliskangasvarastossa alentaisi huomattavasti vaihto-omaisuuden määrää. Kehittämiskohteet on valittu, kehittämistyö on aloitettu ja toimintamallit luotu, Niiden impelementointi ja tietojärjestelmän loppuun kehittäminen vaativat vielä työtä, mutta saavutettavat hyödyt ovat suuret ja turvaavat tehtaan menestymisen tulevaisuudessakin.
Resumo:
Työn tavoitteena oli kartoittaa teknisen tukkukaupan asiakastoimitusprosessin eri vaiheet ja tarjota ratkaisuvaihtoehtoja kuljetusvirheisiin johtavien prosessin vaiheiden kehittämiseksi ja asiakastyytyväisyyden parantamiseksi. Tutkimuksen taustamateriaalia analysoimalla saatiin perusteet käytännön selvitystyön rajaamiseksi pakkaus-, lähettämö- ja lastaustoimintaan sekä kuljetusliikkeiden toimintatapojen tarkasteluun. Selvitystyön perusteella tehtiin johtopäätös, että kuljetusvirheisiin johtavien virhelähteiden ei voida konkreettisesti osoittaa olevan jossain tietyssä prosessin vaiheessa. Merkittävimpiä ongelmakohtia ovat lähettämötoiminnan kontrolloimattomuus sekä lähtevän tavaran puutteelliset merkinnät ja huolimaton käsittely. Tämän seurauksena keskeisiä kuljetusvirheitä ovat tuotteiden katoaminen ja rikkoutuminen. Tutkimustuloksena todetaan, että hyvin organisoidun lähettämötyöskentelyn, selkeiden merkintöjen ja elektronisten seurantajärjestelmien avulla on mahdollista parantaa asiakastoimitusprosessin hallittavuutta sekä vähentää virheiden määrää merkittävästi. Työn lopuksi tehtiin Access –tietokannasta saatuun reaaliaikaiseen reklamaatiodataan perustuva analyysi. Analyysi vahvisti sen, että kuljetusvirheiden määrässä tai syissä ei ole tapahtunut olennaisia muutoksia tutkimuksen aikana eli tutkimustulokset ovat valideja. Analyysiin perustuen tehtiin myös johtopäätös, että tulevaisuudessa pitää panostaa keräilyvirheiden määrän vähentämiseen analysoimalla niiden taustalla olevia tekijöitä.
Resumo:
Tässä työssä tarkastellaan haja-asutusalueilla käytössä olevia kiinteistökohtaisia jäteveden käsittelymenetelmiä. Koelaitteistona oli biologinen pienpuhdistamo, jonka toimintaa tutkittiin tavanomaisessa kotitalouskäytössä. Tarkoituksena oli selvittää jäteveden biologisen suodatuksen soveltuvuutta haja-asutuksen jätevesien käsittelyyn. Kirjallisuusosiossa käsitellään haja-asutuksen jätevesien aiheuttamia ympäristövaikutuksia, ympäristölainsäädäntöä ja yleisesti käytössä olevia erilaisia jäteveden käsittelymenetelmiä, sekä vaihtoehtoisia käymäläratkaisuja. Ennen kokeellisen osuuden alkua asennettiin pienpuhdistamo oheislaitteineen omakotitalon viemärijärjestelmään. Tämän jälkeen päästiin tutkimaan puhdistamon puhdistustehokkuutta ja ympäristökuormitusta lähtevästä jätevedestä keräilynäyttein. Puhdistamolta lähtevän jäteveden kuormitusarvoja verrattiin Ympäristöministeriössä suunnitteilla oleviin enimmäisrajoihin: BOD7 5 g/(d,as), kokonaisfosfori 0,33 g/(d,as) ja kokonaistyppi 8,4 g/(d,as). Mitatut BOD7- ja kokonaistyppikuormitukset alittivat raja-arvot kerran. Muilla mittauskerroilla kuormitus oli enimmäisrajoja suurempi. Kokonaisfosforikuormitus oli kaikilla mittauskerroilla moninkertainen enimmäisrajaan verrattuna. Puhdistamon todellinen BOD7-reduktio oli noin 60 %. Kokonaisfosforin ja kokonaistypen reduktiot vaihtelivat paljon ollen kokonaisfosforilla korkeimmillaan 12 % ja kokonaistypellä 29 %.
Resumo:
This thesis deals with a hardware accelerated Java virtual machine, named REALJava. The REALJava virtual machine is targeted for resource constrained embedded systems. The goal is to attain increased computational performance with reduced power consumption. While these objectives are often seen as trade-offs, in this context both of them can be attained simultaneously by using dedicated hardware. The target level of the computational performance of the REALJava virtual machine is initially set to be as fast as the currently available full custom ASIC Java processors. As a secondary goal all of the components of the virtual machine are designed so that the resulting system can be scaled to support multiple co-processor cores. The virtual machine is designed using the hardware/software co-design paradigm. The partitioning between the two domains is flexible, allowing customizations to the resulting system, for instance the floating point support can be omitted from the hardware in order to decrease the size of the co-processor core. The communication between the hardware and the software domains is encapsulated into modules. This allows the REALJava virtual machine to be easily integrated into any system, simply by redesigning the communication modules. Besides the virtual machine and the related co-processor architecture, several performance enhancing techniques are presented. These include techniques related to instruction folding, stack handling, method invocation, constant loading and control in time domain. The REALJava virtual machine is prototyped using three different FPGA platforms. The original pipeline structure is modified to suit the FPGA environment. The performance of the resulting Java virtual machine is evaluated against existing Java solutions in the embedded systems field. The results show that the goals are attained, both in terms of computational performance and power consumption. Especially the computational performance is evaluated thoroughly, and the results show that the REALJava is more than twice as fast as the fastest full custom ASIC Java processor. In addition to standard Java virtual machine benchmarks, several new Java applications are designed to both verify the results and broaden the spectrum of the tests.
Resumo:
Työssä tutkittiin pienpuhdistamon ylijäämälietteen ominaisuuksia ja käyttäytymistä pienpuhdistamon ylijäämälietteen tiivistys- tai kuivausmenetelmän kehittämisen teoriapohjaksi. Työ sisältää myös lietteiden tiivistysmenetelmien kustannustarkastelua. Kokeellisessa osuudessa käytettiin työn teettäjän Oy KWH Pipe Ab:n valmistamien pienpuhdistamojen ylijäämälietettä. Tutkittava ylijäämäliete oli peräisin asukasvastineluvultaan 5–95 pienistä aktiivilietelaitepuhdistamoista. Tiivistys- tai kuivausmenetelmän kehittämisen tarkoituksena on saavuttaa kustannussäästöjä pienpuhdistamon ylijäämälietteen kuljetusmatkojen vähentämisen kautta. Soveltuvia vertailtavia sovelluksia ovat staattiseen laskeuttamiseen perustuvat menetelmät, mekaaniset ruuvi- ja linkokuivaimet, kuivauslava ja flotaatio. Tarkasteltavien menetelmien tuli olla käytöltä ja huollolta sekä käyttökuluiltaan edullisia ja yksinkertaisia. Ylijäämälietteiden ominaisuuksia ja käyttäytymistä tutkittiin kirjallisuuslähteistä ja käytännön kokein. Kokeissa tarkasteltiin ylijäämälietteen laskeutumis- ja nousuominaisuuksia, redox-potentiaalin vaihtelua seisovassa näytteessä ja flotaation onnistumista testattavalle lietteelle. Kokeet tehtiin kullakin kerralla eri ajankohtana otetuille lietenäytteille, käytettyjä puhdistamoja oli useita ja mitoitus, kuormitus sekä jäteveden laatu vaihteli paljon.
Resumo:
The objective of the research was to study the influence of temperature, oxygen pressure, catalysts loading and initial COD concentration of debarking wastewater on the pollutants during the catalytic oxidation. More importantly, how the addition of catalyst affects the wet oxidation process. The whole work was divided into two main sections, theoretical and experimental parts. The theoretical part reviews the pulp and paper industry from wood processing to paper production as well as operations that generate wastes. Treatment methods applicable for industrial pulp and paper mill effluents were also discussed. Wet oxidation and catalytic wet oxidation processes including mechanism, reactions, kinetics and industrial applications were previewed. In the experimental part, catalytic wet oxidation process were studied at 120-180°C, 0-10 bar oxygen pressure, 0-1 g/L catalyst concentration and 1000-3000 mg/L initial COD concentration. Responses, such as Chemical oxygen demand (COD), Total organic carbon (TOC), colour, lignin/tannin, Biochemical oxygen demand (BOD) and pH were measured. In the experiment, the best conditions occurred at 180°C, 10 bar, l g/L catalyst concentration and 3000mg/L initial COD. At these conditions; 74% COD, 97% lignin/tannin, 54% TOC, 90% colour were removed from the wastewater. pH was greatly reduced from 7 to 4.6. Lignin/tannin was removed most. Lignin/tannin showed linear dependency with colour during oxidation. Temperature made the most impact in reducing contaminants in debarked wastewater.
Resumo:
La efectividad técnica de golpeo (ET) se ha identificado como un buen parámetro pronosticador del rendimiento en el tenis y la frecuencia de golpeo de pelotas (FGP), aunque es un parámetro de carga técnica y condicional poco utilizado, es un indicador capaz de detectar diferencias en el juego. El objetivo del estudio fue caracterizar la ET en función de la FGP en una jugadora profesional de máximo nivel competitivo, utilizando un protocolo maximal, continuo de intensidad progresiva y registrando paralelamente parámetros de carga y fisiológicos. Se ejecutaron un total de 212 golpes obteniendo una ET del 81.6 % de aciertos, los valores oscilaron a lo largo de la prueba entre un rango del 81.6 a 93.3 % de aciertos y únicamente disminuyeron hasta el 70.7 % en el último periodo alcanzado (UP) y a partir del punto de disminución de ET (PDET). Se alcanzó una FGP máxima (FGPmax) de 21 golpes·min-1, una duración de la prueba (DP) de 14:07 (min:s) correspondiente a un UP de 7. Se concluye que la jugadora presenta una elevada ET y una importante capacidad de mantener unos elevados indicies de ET, a pesar del incremento de la FGP y de la fatiga metabólica asociada.
Resumo:
The amphiphilic nature of metal extractants causes the formation of micelles and other microscopic aggregates when in contact with water and an organic diluent. These phenomena and their effects on metal extraction were studied using carboxylic acid (Versatic 10) and organophosphorus acid (Cyanex 272) based extractants. Special emphasis was laid on the study of phase behaviour in a pre neutralisation stage when the extractant is transformed to a sodium or ammonium salt form. The pre neutralised extractants were used to extract nickel and to separate cobalt and nickel. Phase diagrams corresponding to the pre neutralisation stage in a metal extraction process were determined. The maximal solubilisation of the components in the system water(NH3)/extractant/isooctane takes place when the molar ratio between the ammonia salt form and the free form of the extractant is 0.5 for the carboxylic acid and 1 for the organophosphorus acid extractant. These values correspond to the complex stoichiometry of NH4A•HA and NIi4A, respectively. When such a solution is contacted with water a microemulsion is formed. If the aqueous phase contains also metal ions (e.g. Ni²+), complexation will take place on the microscopic interface of the micellar aggregates. Experimental evidence showing that the initial stage of nickel extraction with pre neutralised Versatic 10 is a fast pseudohomogeneous reaction was obtained. About 90% of the metal were extracted in the first 15 s after the initial contact. For nickel extraction with pre neutralised Versatic 10 it was found that the highest metal loading and the lowest residual ammonia and water contents in the organic phase are achieved when the feeds are balanced so that the stoichiometry is 2NH4+(org) = Nit2+(aq). In the case of Co/Ni separation using pre neutralised Cyanex 272 the highest separation is achieved when the Co/extractant molar ratio in the feeds is 1 : 4 and at the same time the optimal degree of neutralisation of the Cyanex 272 is about 50%. The adsorption of the extractants on solid surfaces may cause accumulation of solid fine particles at the interface between the aqueous and organic phases in metal extraction processes. Copper extraction processes are known to suffer of this problem. Experiments were carried out using model silica and mica particles. It was found that high copper loading, aromacity of the diluent, modification agents and the presence of aqueous phase decrease the adsorption of the hydroxyoxime on silica surfaces.
Resumo:
Initially, all major factors that affect the rate of the AldH-catalyzed reaction (enzyme concentration, substrate concentration, temperature and pH) were investigated. Optimal activity was observed between pH values of 7.5 and 9.5 in the temperature range of 25 to 50 ºC. Kinetic parameters, such as Km (2.92 µmol L-1) and Vmax (1.33 10-2 µmol min-1) demonstrate a strong enzyme-substrate affinity. The sensors were based on screen-printed electrodes modified with the Meldola Blue-Reinecke salt (MBRS) combination. Operational conditions (NAD+ and substrate contents, enzyme loading and response time) were optimized. Also, two enzyme immobilization procedures were tested: entrapment in poly(vinyl alcohol) bearing styrylpyridinium groups (PVA-SbQ) and crosslinking with glutaraldehyde. Chronoamperometry was employed to observe the biosensor responses during enzymatic hydrolysis of propionaldehyde and also to construct inhibition curves with maneb and zineb fungicides. Best results were found with the following conditions: [NAD+] = 0.25 mmol L-1; [propionaldehyde] = 80 µmol L-1; enzyme loading = 0.8 U per electrode; response time = 10 min, and inhibition time = 10 min. Current intensities around 103 ± 13 nA with the sensors and good stability was obtained for both immobilization procedures. Detection limits, calculated using 10% inhibition were 31.5 µg L-1 and 35 µg L-1 for maneb and zineb, respectively. Results obtained with other MBRS-modified electrodes consisting of mono and bi-enzymic sensors were compared. The ability to catalyze NADH oxidation by MB was also highlighted.