Injection Duration (injection + duration)

Distribution by Scientific Domains


Selected Abstracts


New supplying evaporation precursor method with CVD

HEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 5 2009
Motohiro Oshima
Abstract We propose a novel system of chemical vapor deposition (CVD), i.e., flash boiling spray CVD (SF-CVD) to eliminate several kinds of problems, such as the decomposition of precursors in the supply line and evaporator. In this method, liquid precursors are supplied directly to the vacuum chamber through an injector, just like fuel for an automobile engine, without any vaporizers, so as to induce an unsteady and intermittent flash boiling spray in the chamber. However, it is necessary to keep the lowest ambient pressure possible because the saturated vapor pressure of the precursors is very low. Thus, this is very useful for modifying the saturated vapor pressure of the precursors. A technique of lowering the vaporization pressure is proposed by mixing a more saturated vapor-pressure organic solvent with a precursor. To determine the principles underlying FS-CVD, we first formed SiO2 film on the Si substrate. A mixed solution of tetraethylorthosilicate (TEOS) and n-pentane was used as the mixing solution. The film thickness distribution of SiO2 film on a 100-mm-diameter Si wafer was ±4% using this method. Furthermore, this method enabled us to control film with various thicknesses by optimizing the injection duration, cycle, and injection cycle per second. © 2009 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20235 [source]


An experimental investigation on manifold-injected hydrogen as a dual fuel for diesel engine system with different injection duration

INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 15 2009
N. Saravanan
Abstract Stringent emission norms and rapid depletion of petroleum resources have resulted in a continuous effort to search for alternative fuels. Hydrogen is one of the best alternatives for conventional fuels. Hydrogen has both the benefits and limitation to be used as a fuel in an automotive engine system. In the present investigation, hydrogen was injected into the intake manifold by using a hydrogen gas injector and diesel was introduced in the conventional, mode which also acts as an ignition source for hydrogen combustion. The flow rate of hydrogen was set at 5.5,l,min,1 at all the load conditions. The injection timing was kept constant at top dead center (TDC) and injection duration was adjusted to find the optimized injection condition. Experiments were conducted on a single cylinder, four stroke, water-cooled, direct injection diesel engine coupled to an electrical generator. At 75% load the maximum brake thermal efficiency for hydrogen operation at injection timing of TDC and with injection duration of 30°CA is 25.66% compared with 21.59% for diesel. The oxides of nitrogen (NOX) emission are 21.7,g,kWh,1 for hydrogen compared with diesel of 17.9,g,k,Wh,1. Smoke emissions reduced to 1 Bosch smoke number (BSN) in hydrogen compared with diesel of 2.2 BSN. Hydrogen operation in the dual fuel mode with diesel exhibits a better performance and reduction in emissions compared with diesel in the entire load spectra. Copyright © 2009 John Wiley & Sons, Ltd. [source]


A study on the effect of the duration of subcutaneous heparin injection on bruising and pain

JOURNAL OF CLINICAL NURSING, Issue 3 2008
Ayten Zaybak PhD
Aim., This study was carried out to determine the effect of injection duration on bruising and pain following the administration of the subcutaneous injection of heparin. Background., Although different methods to prevent bruising and pain following the subcutaneous injection of heparin have been widely studied and described, the effect of injection duration on the occurrence of bruising and pain is little documented. Design., This study was designed as within-subject, quasi-experimental research. Method., The sample for the study consisted of 50 patients to whom subcutaneous heparin was administered. Heparin was injected over 10 seconds on the right abdominal site and 30 seconds on the left abdominal site. Injections areas were assessed for the presence of bruising at 48 and 72 hours after each injection. Dimensions of the bruising on the heparin applied areas were measured using transparent millimetric measuring paper. The visual analog scale (VAS) was used to measure pain intensity and a stop-watch was used to time the pain period. Data were analysed using chi-square test, Mann,Whitney U, Wilcoxon signed ranks tests and correlation. Results., The percentage of bruising occurrence was 64% with the injection of 10 seconds duration and 42% in the 30-second injection. It was determined that the size of the bruising was smaller in the 30-second injection. Pain intensity and pain period were statistically significantly lower for the 30-second injection than for the 10-second injection. Conclusions., It was determined that injection duration had an effect on bruising and pain following the subcutaneous administration of heparin. This study should be repeated on a larger sample. Relevance to clinical practice., When administering subcutaneous heparin injections, it is important to extend the duration of the injection. [source]


Study of onset time-shift and injection duration in DCE-MRI: a comparison of a reference region model with the general kinetic model

NMR IN BIOMEDICINE, Issue 4 2010
Ing-Tsung Hsiao
Abstract In dynamic contrast-enhanced MR imaging (DCE-MRI), sampling of the arterial input function (AIF) is required for analysis using the general kinetic model (GKM). Alternatively, the recently proposed reference region model (RRM) may be employed to avoid the need of acquiring the AIF. This study aimed to evaluate the influence of the AIF onset-time shift and the injection duration, under various sampling intervals, on physiological parameter estimation in DCE-MRI using the GKM, and to compare the performance between GKM and RRM. Computer simulations were performed to assess the mean error (ME) and coefficient of variation (CoV) of Ktrans,TOI and ve,TOI from shifted and dispersed AIF with temporal resolution of 1, 5 and 10,s. With 5-s sampling, the maximal ME of Ktrans,TOI was roughly 22% for the GKM and 0.5% for the RRM. With 10-s sampling, they increased to around 28% and 0.7%, respectively. The maximal MEs of ve,TOI for all cases were under 5%. However, owing to the lower SNR in the reference region, the CoV obtained by the RRM were all higher than those by the GKM. The results suggested that with compromised temporal resolution, the RRM was relatively less sensitive to the AIF onset-time shift and the injection duration compared with the GKM. Copyright © 2009 John Wiley & Sons, Ltd. [source]