Fill Time Research Articles

A Back Propagation Artificial Neural Network Prediction Model of the Gate Freeze Time for Injection Molded Polypropylenes

This paper presents a back propagation artificial neural network (BP ANN) prediction model of the gate freeze time (tgf) for injection molded polypropylenes. An orthogonal design method was applied to enhance the BP ANN performance. The test results on the performance of the BP ANN prediction model showed that it can predict tgf with reasonable accuracy. Utilizing the BP ANN prediction model, the effects of the process factors, melt temperature (Tme), fill time (tf), gate area (Ain), packing pressure (Pp), and mold temperature (Tmo) on tgf were investigated. The simulation results showed that the most important process factor affecting tgf was Tme, followed by tf, Ain, and Pp, with Tmo having the least effect. The gate freeze time increased with elevated Tme, tf, Ain, and Pp.

Ignition capsules with aerogel-supported liquid DT fuel for the National Ignition Facility

For high repetition-rate fusion power plant applications, capsules with aerogel-supported liquid DT fuel can have much reduced fill time compared to β-layering a solid DT fuel layer. The melting point of liquid DT can be lowered once liquid DT is embedded in an aerogel matrix, and the DT vapor density is consequently closer to the desired density for optimal capsule design requirement. We present design for NIF-scale aerogel-filled capsules based on 1-D and 2-D simulations. An optimal configuration is obtained when the outer radius is increased until the clean fuel fraction is within 65 – 75% at peak velocity. A scan (in ablator and fuel thickness parameter space) is used to optimize the capsule configurations. The optimized aerogel-filled capsule has good low-mode robustness and acceptable high-mode mix.

A microfluidic anti-Factor Xa assay device for point of care monitoring of anticoagulation therapy

The development of new point of care coagulation assay devices is necessary due to the increasing number of patients requiring long-term anticoagulation in addition to the desire for appropriate, targeted anticoagulant therapy and a more rapid response to optimization of treatment. The majority of point of care devices currently available for hemostasis testing rely on clot-based endpoints which are variable, unreliable and limited to measuring only certain portions of the coagulation pathway. Here we present a novel fluorescence-based anti-Factor Xa (FXa) microfluidic assay device for monitoring the effect of anticoagulant therapy at the point of care. The device is a disposable, laminated polymer microfluidic strip fabricated from a combination of hydrophobic and hydrophilic cyclic polyolefins to allow reagent deposition in addition to effective capillary fill. Zeonor was the polymer of choice resulting in low background fluorescence (208.5 AU), suitable contact angles (17.5°± 0.9°) and capillary fill times (20.3 ± 2.1 s). The device was capable of measuring unfractionated heparin and tinzaparin from 0-0.8 U ml(-1) and enoxaparin from 0-0.6 U ml(-1) with average CVs < 10%. A linear correlation was observed between the device and the fluorescent assay in the plate for plasma samples spiked with UFH, with an R(2) value of 0.99, while correlations with tinzaparin and enoxaparin resulted in sigmoidal responses (R(2) = 0.99). Plasma samples containing UFH resulted in a linear correlation between the device and a standard chromogenic assay with an R(2) value of 0.98, with both LMWHs resulting in sigmoidal relationships (R(2) = 0.99).

플라스틱 레귤레이터 레일 성형 최적화연구

플라스틱 소재를 사용한 사출성형부품은 차량 경량화뿐만 아니라 충격흡수를 통한 운전자와 보행자 보호, 제품 디자인의 자율성등의 우수한 장점을 가지고 있어 그 사용량이 급속히 증가하고 있다. 유리섬유함유 플라스틱재료를 이용한 레귤레이터 레일의 사출성형시 불량률최소화를 위해 유한요소해석과 실험계획법을 사용하여 성형공정중의 휨변형량(warpage)과 수축변형를 최소화할 수 있는 최적의 성형조건을 제시하고자 한다. 또한 유리섬유의 유동성과 냉각효율의 확보를 위해 최적의 게이트 및 런너방식을 설정한다. 사출금형을 제작하여 제품을 성형제작한 후 휨변형등의 성능확인을 통해 해석방법의 유효성과 최적화의 실효성을 확인하고자 한다. Injection molding product is commonly used for reducing the weight of automotive vehicle, and door regulator guide rail with plastic material is also made by injection molding process. In order to improve the injection molding performance of plastic regulator guide rail, optimal molding condition is suggested by numerical simulation and DOE after obtaining the sensitivity of parameters for regulator rail manufacturing on warpage and fill time. Furthermore, multi direct gate method and optimal cooling circuit are introduced to get the uniform temperature distribution and better cooling efficiency in molding product. The effect of the proposed design on the injection molding performance is verified by the test of prototype of plastic regulator guide rail.

Computation of Filling Time of a Ship Lock

In this paper, Steady-flow Integration Approach (SIA) and Volume of Fluid (VOF) method are both used to calculate the filling time of a ship lock. The values of filling time derived from these two different methods have the same order of magnitude. SIA is only used to give a quick but coarse estimation; however in the application of more time-consuming VOF approach, the fluctuations of water surface are additionally considered and computed, It provides a more precise estimation of the filling time and a more realizable details about the filling process. In practical engineering, the geometry of ship lock will be far more complex than here; the SIA is not enough to satisfy the demands for a desired design. The VOF method will be a nice choice and give reasonable predictions of filling time, water fluctuations and velocity fields in the ship lock.

Arterial Sampler Filling Time During Arterial and Venous Punctures, and Its Relationship with Mean Arterial Pressure in Human Subjects

When obtaining an arterial blood sample via percutaneous puncture, there is a risk of accidentally obtaining venous blood. Conventional methods of confirming arterial blood at the bedside, such as blood color and pulsatile return, can be misleading in patients with low blood pressure or hypoxemia. To determine if the arterial sampler filling time can be an accurate indicator of obtaining an arterial blood sample in subjects with various blood pressures. Our hypotheses were that there would be a statistically significant negative correlation between sampler filling time during arterial puncture and mean arterial blood pressure, and a statistically significant difference between venous and arterial filling times in human adults. Prior to an arterial puncture, we measured and recorded arterial blood pressure noninvasively. During the arterial and venipuncture procedures we measured the amount of time it took to fill the sampler and the volume of blood obtained. A t test for independent samples was calculated to determine if mean arterial sampler filling times were significantly different between the arterial and venous groups. Pearson correlation coefficient was calculated to determine the relationship between mean arterial pressure and seconds of filling time per milliliter in the arterial group. This study included 38 human subjects; 22 were adult patients ordered for arterial blood gases by arterial puncture; 16 were normal, healthy, adult volunteers who had a venipuncture performed using an arterial blood sampler. The mean ± SD filling time was 15 ± 4 s/mL for the arterial group and 115 ± 48 s/mL for the venous group, and the difference was significant (P < .001). The range of mean arterial pressures was 69-125 mm Hg; the average mean arterial pressure was 91 ± 13 mm Hg, and the Pearson correlation coefficient for mean arterial pressures and sampler filling times was -0.49 (P = .02). Our results were consistent with a laboratory study showing a significant difference between arterial and venous filling times and a negative correlation between mean arterial pressure and sampler filling time, but our times in adult subjects were longer. Respiratory therapists may find arterial sampler filling time as a useful indicator of successful arterial puncture at the bedside.

Modeling and design of anX-band rf photoinjector

A design for an $X$-band rf photoinjector that was developed jointly by SLAC National Accelerator Laboratory (SLAC) and Lawrence Livermore National Laboratory (LLNL) is presented. The photoinjector is based around a 5.59 cell rf gun that has state-of-the-art features including: elliptical contoured irises; improved mode separation; an optimized initial half cell length; a racetrack input coupler; and coupling that balances pulsed heating with cavity fill time. Radio-frequency and beam dynamics modeling have been done using a combination of codes including PARMELA, HFSS, IMPACT-T, ASTRA, and the ACE3P suite of codes developed at SLAC. The impact of lower gradient operation, magnet misalignment, solenoid multipole errors, beam offset, mode beating, wakefields, and beam line symmetry have been analyzed and are described. Fabrication and testing plans at both LLNL and SLAC are discussed.

Simulating the effect of temperature elevation on clamping force requirements during rigid-tool Liquid Composite Moulding processes

Moulds used for rigid-tool Liquid Composite Moulding (LCM) processes, namely Resin Transfer Moulding (RTM) and Compression RTM, are often subjected to large internal forces which originate due to resin injection and from the compaction of fibre reinforcements. Appropriate clamping equipment (e.g. press or perimeter clamps) is necessary to equilibrate these forces. An optimal selection (or design) of such clamping equipment calls for an accurate prediction of the tooling forces generated. This work aims to introduce a comprehensive numerical scheme which addresses this issue, including the case of non-isothermal mould filling. A hybrid Finite Element/Finite Difference (FE/FD) methodology is utilised for solving the coupled flow/energy/species equations. A new fibre compaction model, developed in order to reduce computational complexity while maintaining solution accuracy, is implemented into the simulation algorithm. The force predictions obtained for a planar axisymmetric part reveal that the chosen combination of mould and resin temperatures, together with other process variables, plays a crucial role in allowing fast fill times while keeping setup costs low.

Tissue Doppler Time Intervals Predict the Occurrence of Rehospitalization in Chronic Heart Failure: Data from the Daunia Heart Failure Registry

Patients with chronic heart failure (HF) are often rehospitalized; rehospitalization identifies subjects with a poorer quality of life and a worse prognosis. Estimates of the time intervals by tissue Doppler imaging (TDI) in patients with chronic HF has not been fully investigated, despite recent studies having explored the prognostic role of TDI-derived parameters in major cardiac diseases, such as HF. We, therefore, aimed to assess the prognostic value of time intervals evaluated by TDI in patients with chronic HF. A total of 249 patients with chronic HF enrolled in the Daunia Heart Failure Registry underwent echocardiography assessment and were followed prospectively for a mean 284 ± 210 days. Conventional echocardiography and TDI parameters were calculated; time intervals were calculated by TDI: ST (systolic time), ET (ejection time), FT (filling time), and ICT (isovolumic contraction time). We also have calculated ICT/ET and tissue myocardial performance index ([ICT+IRT]/ET). At univariate analysis, ET (RR: 0.80, 95% confidence interval [CI] 0.71-0.90, P < 0.001), ST (RR: 0.88, 95% CI 0.78-0.99, P < 0.05), FT (RR: 0.88, 95% CI 0.78-0.99, P < 0.05), ICT/ET (RR: 1.21, 95% CI 1.07-1.37, P < 0.01) were related to the occurrence of rehospitalization during follow-up. At multivariate Cox regression analysis, correlations remained significant for ET and ST (P < 0.05 and P < 0.01, respectively). Time intervals assessed by TDI may be helpful in predicting the risk of rehospitalization in subjects with chronic HF.

Assessment of cerebral venous return by a novel plethysmography method

Magnetic resonance imaging and echo color Doppler (ECD) scan techniques do not accurately assess the cerebral venous return. This generated considerable scientific controversy linked with the diagnosis of a vascular syndrome known as chronic cerebrospinal venous insufficiency (CCSVI) characterized by restricted venous outflow from the brain. The purpose of this study was to assess the cerebral venous return in relation to the change in position by means of a novel cervical plethysmography method. This was a single-center, cross-sectional, blinded case-control study conducted at the Vascular Diseases Center, University of Ferrara, Italy. The study involved 40 healthy controls (HCs; 18 women and 22 men) with a mean age of 41.5 ± 14.4 years, and 44 patients with multiple sclerosis (MS; 25 women and 19 men) with a mean age of 41.0 ± 12.1 years. All participants were previously scanned using ECD sonography, and further subset in HC (CCSVI negative at ECD) and CCSVI groups. Subjects blindly underwent cervical plethysmography, tipping them from the upright (90°) to supine position (0°) in a chair. Once the blood volume stabilized, they were returned to the upright position, allowing blood to drain from the neck. We measured venous volume (VV), filling time (FT), filling gradient (FG) required to achieve 90% of VV, residual volume (RV), emptying time (ET), and emptying gradient (EG) required to achieve 90% of emptying volume (EV) where EV = VV - RV, also analyzing the considered parameters by receiver operating characteristic (ROC) curves and principal component mathematical analysis. The rate at which venous blood discharged in the vertical position (EG) was significantly faster in the controls (2.73 mL/second ± 1.63) compared with the patients with CCSVI (1.73 mL/second ± 0.94; P = .001). In addition, respectively, in controls and in patients with CCSVI, the following parameters were highly significantly different: FT 5.81 ± 1.99 seconds vs 4.45 ± 2.16 seconds (P = .003); FG 0.92 ± 0.45 mL/second vs 1.50 ± 0.85 mL/second (P < .001); RV 0.54 ± 1.31 mL vs 1.37 ± 1.34 mL (P = .005); ET 1.84 ± 0.54 seconds vs 2.66 ± 0.95 seconds (P < .001). Mathematical analysis demonstrated a higher variability of the dynamic process of cerebral venous return in CCSVI. Finally, ROC analysis demonstrated a good sensitivity of the proposed test with a percent concordant 83.8, discordant 16.0, tied 0.2 (C = 0.839). Cerebral venous return characteristics of the patients with CCSVI were markedly different from those of the controls. In addition, our results suggest that cervical plethysmography has great potential as an inexpensive screening device and as a postoperative monitoring tool.

Impact of Final Short-Fill Rule on Medicare Part D Costs and Long-Term Care Pharmacy Dispensing

To evaluate the impact of the final Centers for Medicare & Medicaid Services' (CMS) "short-fill" rule regarding the appropriate dispensing of prescription drugs in long-term care facilities. A prospective study to determine rates of unconsumed medication and the net-cost impact on Medicare Part D prescription drug plans based on the proposed and final CMS rule and other scenarios under consideration by CMS. Four hundred twenty-five long-term care facilities in six states. Residents covered by Medicare Part D. Rates of unconsumed medication, average dispensing fees, potential reduction in unconsumed medication, incremental fills, incremental dispensing fees, net cost or savings to Medicare Part D plans, and percentage increase in fills. Total estimates of the cost of unconsumed medication charged to Medicare Part D plans for residents in long-term care facilities are $87 million for brand products and $39 million for generics annually. Based on current dispensing fees, it is likely that implementation of the final rule will result in incremental costs to CMS plans in the range of $30 million annually. The number of Medicare Part D prescription fills will increase by about 20%. A seven-day fill requirement on brand products would raise incremental costs to more than $150 million annually, and inclusion of generic products in a seven-day fill requirement would result in incremental costs in the range of $850 million annually. The final CMS rule on short-fills is unlikely to result in savings to Medicare Part D plans. Shorter fill times and inclusion of generic products would significantly raise costs to these plans.

New Methord of Optimizing the Filling Time in Injection Molding

In order to acquire the best filling time, Mold trial is made by setting different injection time, or Moldflow software is used to analysis data recorded by computer. Whether doing successive trials or being simulated point by point, is very tedious. Put forward a method of using the Lagrange to simulate a curve based on the mold flow analysis, the minimum of the curve is the best filling time. This method can gain the best filling time as quickly as possible, and improve the efficiency of the mold flow analysis.

Nutrient demand interacts with grass particle length to affect digestion responses and chewing activity in dairy cows

Effects of grass particle length on dry matter intake (DMI), milk production, ruminal fermentation and pool sizes, digestion and passage kinetics, and chewing activity and the relationship of these effects with preliminary DMI (pDMI) were evaluated using 15 ruminally and duodenally cannulated Holstein cows in a crossover design with a 14-d preliminary period and two 18-d treatment periods. During the preliminary period, pDMI of individual cows ranged from 22.6 to 29.8kg/d (mean=25.8kg/d) and 3.5% fat-corrected milk yield ranged from 29.2 to 56.9kg/d (mean=41.9kg/d). Experimental treatments were diets containing orchardgrass silage chopped to either (a) 19-mm (long) or (b) 10-mm (short) theoretical length of cut as the sole forage. Grass silages contained approximately 46% neutral detergent fiber (NDF); diets contained 50% forage, 23% forage NDF, and 28% total NDF. Preliminary DMI, an index of nutrient demand, was determined during the last 4 d of the preliminary period when cows were fed a common diet and used as a covariate. Main effects of grass particle length and their interaction with pDMI were tested by ANOVA. Grass particle length and its interaction with pDMI did not affect milk yield, milk composition, or rumen pH. Long particle length tended to decrease DMI compared with short particle length, which might have been limited by rumen fill or chewing time, or both. Passage rates of feed fractions did not differ between long and short particle lengths and were not related to level of intake. As pDMI increased, long particles decreased ruminal digestion rate of potentially digestible NDF at a faster rate than short particles. As a result, long particles decreased or tended to decrease rates of ruminal turnover for NDF, organic matter, and dry matter and increased their rumen pools compared with short particles for cows with high pDMI. Long particles increased eating time, which affected cows with high intake to the greatest extent, and total chewing time compared with short particles. As intake increased, ruminal digestion (kg/d) and digestibility (%) of starch decreased, rumen pool size of starch increased, and postruminal digestion and digestibility of starch increased quadratically. When grass silage was the only source of forage in the diet, increasing chop length from 10 to 19mm tended to decrease DMI but did not negatively affect productivity of cows, which were fed adequate fiber.

Biodegradation of benzene-toluene-xylene in petrochemical industries wastewater through anaerobic sequencing biofilm batch reactor in bench scale

Aims: This study aims to evaluate the performance of the anaerobic sequencing batch biofilm reactor (ASBBR) for biodegradation of Benzene-Toluene-Xylene (BTX) that is present in petrochemical synthetic wastewater. Materials and Methods: A laboratory-scale ASBBR was used to treat a synthetic substrate mixture representing petrochemical wastewater that contained BTX. The operation schedule was: Fill time: 10 minutes, reaction time: 22.8 hours, settling time: 60 minutes, and decant time: 10 minutes, at 35΀C. The BTX samples were analyzed by gas chromatography-flame ionization detector (GC-FID) equipped with head space. Results: After reaching to stable operation, the reactor was exposed to influent BTX concentrations of 5, 20, and 50 mg/l, with overall organic loading rate of 3 g COD/l.d resulting in 61, 79, and 50% removal efficiencies for the BTX, respectively. At this time, the removal efficiencies for COD were 75, 90, and 70%.Conclusions: The optimum BTX removal of 79% was achieved in 3 g COD/l.d and HRT of 3.8 days, at influent BTX concentration of 20 mg/l. Thus, it could be concluded that ASBBR was a feasible, efficient, and consistent technology for treatment of petrochemical wastewaters containing BTX. The ASBBR might be an alternative to intermittent systems as well as batch systems due to its superior operational flexibility.

Aperture Effect Influence and Analysis of Wideband Phased Array Radar

Wideband phased array becomes a research focus with the development of modern radar technology.Wideband phased array radar is one of the advanced radar technology. However, the aperture fill time results in the beam pointing offset, limits the instantaneous bandwidth and effects of the 1-D target range profile. This paper analyses the scheme of sub-array compensation for aperture fill time. For LFM signals system, we analyze the compensation using filters for aperture fill time, and for stepping frequency signal system, we analyze the scheme of interveinal phase matching, then simulate by Matlab. The simulation results show that the sub array division technology can compensate the aperture effect and increase the instantaneous bandwidth effectively. Both the filter and the interveinal phase matching methods can solve the main lobe expansion and targets range migration; lastly get the high resolution range profile.

Modeling Extreme Bottom-Up Filling of Through Silicon Vias

Extreme bottom-up superfilling of through silicon vias (TSV) was recently described wherein deposition occurs on the bottom surface of the vias with negligible deposition on their sidewalls or the field around them. The process uses a deposition suppressing adsorbate subject to breakdown through the metal deposition reaction. Positive feedback associated with this suppressor disruption coupled with resistive electrolyte losses underlies the bottom-up feature filling dynamic by distributing the applied potential between the interface double layer and the bulk electrolyte in a time dependent manner. A simple pseudo steady state model that links suppressor disruption with the potential drop between the reference and working electrodes in resistive electrolytes is shown to capture essential aspects of the bottom-up filling process. Understanding the coupling of potential and additive concentration gradients provides a rational design strategy for bottom-up filling of recessed surface features that offers to minimize unneeded deposition on the substrate surface thereby substantially decreasing fill times and improving materials utilization.

Plating Opportunities in 3D

Through Silicon Via's (TSV) are one of the key enabling technologies towards 3D packaging. Copper electroplating is frequently mentioned as candidate to fill TSV's besides polySi or ink-jetting conductive inks and attracts high attention. In addition to copper plating solder plating offers the next opportunity. Last but not least the ultimate target of an “all wet TSV” where also barrier and seed layers are electroplated, was demonstrated already. This paper targets to introduce the 3D related plating technologies and will encourage a discussion about targets to be meet in order to enable 3D. Even so copper plating is well introduced to the IC industry for Dual Damascene plating, TSV copper filling challenges the plating technology. One of the reasons why is that TSV dimensions are almost one magnitude larger than dual damascene structures. So in order to meet the industries target of fast and void free copper filling, type and function of organic additives applied in copper plating bathes need to be re investigated. Galvanic copper electrolytes contain three organic additives. Carrier is a mild plating suppressor, Brightener is an accelerator, and Leveler is a strong suppressor and locally deactivates the Brightener. The Leveler component mainly affects the properties of the copper deposits. This paper will give an overview about type and role of organic additives used for TSV application. We will also discuss how namely the Leveler controls the filling mechanism and copper deposit properties. Two different acidic copper systems were used for TSV-filling. System A shows a super-conformal filling behavior and different copper grain structures at the surface compared to the TSV body. System B shows a bottom-up filling with similar copper grain structure at surface and TSV body. Both systems vary further regarding stress of the copper deposits, recrystallization temperature, incorporation of additives, and coefficient of thermal expansion. The paper discusses the influence of organic copper additives to the mechanical, thermal, and electrical properties of the copper deposits. Even so process technology to fill TSV's is still fast progressing we like to give a snapshot of fill times per TSV dimension reached using System B. Other potential plating applications in 3D stacking are eventually plating solder and/or diffusion barriers. This paper intends to introduce the basic principles of electrochemical and electroless plating and give application examples for Tin and Nickel/Palladium electroless plated layers applied for 3D packaging applications. Last but not least the concept of “all wet TSV” appears in the literature, targeting to substitute the barrier and seed layer so fare deposited by vacuum deposition technology by plating technologies. We will shortly review the literature and will introduce work currently under progress in Atotech towards an “all wet TSV”.

Coiled-tube heat exchanger for High-Pressure Metal Hydride hydrogen storage systems – Part 1. Experimental study

This two-part study explores the development and thermal performance of a coiled-tube heat exchanger for hydrogen fuel cell storage systems utilizing High-Pressure Metal Hydride (HPMH). The primary purpose of this heat exchanger is to tackle the large amounts of heat released from the exothermic hydriding reaction that occurs when the hydrogen is charged into the storage vessel and is absorbed by the HPMH. The performance of heat exchanger was tested using 4 kg of Ti 1.1CrMn at pressures up to 280 bar. Tests were performed to assess the influence of different operating conditions on the effectiveness of the heat exchanger at removing the heat in a practical fill time (time required to complete 90% of the hydriding reaction). It is shown that distance of metal hydride particles from the coolant tube has the most dominant influence on hydriding rate, with particles closer to the tube completing their hydriding reaction sooner. Faster fill times were achieved by reducing coolant temperature and to a lesser extent by increasing pressurization rate. By comparing tests with and without coolant flow, it is shown that the heat exchanger reduces fill time by 75% while occupying only 7% of the storage pressure vessel volume. The second part of this study will present a 3D computational heat transfer model of the storage vessel and heat exchanger, and compare the model predictions to the experimental data.

Comparative Analysis of Automotive Interior Trim Materials Based on Moldflow

The influence of different materials on the formability of plastic injection molding has been studied in current work. The automotive glove box trim cover was chosen as analytical model. This study has been focused on the influence on fill time, warpage, sink mark depth and clamp force of different materials. PP+T15, PP+T20, PP+T25, PP+T30, PP+T35, PP+T40 and ABS+PC were used for analysis in this study. The injection molding processes of automotive interior trim of different materials were analyzed by using Moldflow software, the rationality of the material choice was evaluated. Merits and drawbacks of different materials were found out through the analysis done in Moldflow. There is positive influence on reducing mold cycle and negative influence on advancing the dimension stability of part by using the kind of PP materials. Oppositely, there is negative influence on reducing mold cycle and positive influence on advancing the dimension stability of part by using ABS. It can be reduce extremely the cost for manufacturing the mold, and shorten the development cycle by using this method.

The inevitable queue: exploring the impact of wait time at sporting events

While the goal of almost any service provider is to eliminate wait from the consumption experience, there are a number of service environments where this ideal may be impractical, if not impossible, to deliver, among them live sport. Live sporting events often have queues at entry and exit gates, facility concessions and toilets. This study tests a model featuring antecedents not used in prior research on waiting. Findings suggest that facility layout features and waiting fill time both have a positive influence on spectators' feelings about a wait. Most interestingly perhaps, these same antecedents may also serve as a cue that long waits are likely.