High Collection Rate Research Articles

Integrated Science Investigation of the Sun (ISIS): Design of the Energetic Particle Investigation

The Integrated Science Investigation of the Sun (ISIS) is a complete science investigation on the Solar Probe Plus (SPP) mission, which flies to within nine solar radii of the Sun’s surface. ISIS comprises a two-instrument suite to measure energetic particles over a very broad energy range, as well as coordinated management, science operations, data processing, and scientific analysis. Together, ISIS observations allow us to explore the mechanisms of energetic particles dynamics, including their: (1) Origins—defining the seed populations and physical conditions necessary for energetic particle acceleration; (2) Acceleration—determining the roles of shocks, reconnection, waves, and turbulence in accelerating energetic particles; and (3) Transport—revealing how energetic particles propagate from the corona out into the heliosphere. The two ISIS Energetic Particle Instruments measure lower (EPI-Lo) and higher (EPI-Hi) energy particles. EPI-Lo measures ions and ion composition from ∼20 keV/nucleon–15 MeV total energy and electrons from ∼25–1000 keV. EPI-Hi measures ions from ∼1–200 MeV/nucleon and electrons from ∼0.5–6 MeV. EPI-Lo comprises 80 tiny apertures with fields-of-view (FOVs) that sample over nearly a complete hemisphere, while EPI-Hi combines three telescopes that together provide five large-FOV apertures. ISIS observes continuously inside of 0.25 AU with a high data collection rate and burst data (EPI-Lo) coordinated with the rest of the SPP payload; outside of 0.25 AU, ISIS runs in low-rate science mode whenever feasible to capture as complete a record as possible of the solar energetic particle environment and provide calibration and continuity for measurements closer in to the Sun. The ISIS Science Operations Center plans and executes commanding, receives and analyzes all ISIS data, and coordinates science observations and analyses with the rest of the SPP science investigations. Together, ISIS’ unique observations on SPP will enable the discovery, untangling, and understanding of the important physical processes that govern energetic particles in the innermost regions of our heliosphere, for the first time. This paper summarizes the ISIS investigation at the time of the SPP mission Preliminary Design Review in January 2014.

Use of volume correlation model to calculate lifetime of end-of-life steel

A new mathematical model for calculating the lifetime of steel on an annual basis, called the volume correlation model is presented. The model compares the quantities of scrap collection with the steel consumption as well as evaluates the time difference between the two data sets. The lifetime of steel was calculated for the collected end-of-life steel amounts. The calculations were performed by assuming a full recovery of the steel consumption or a non-re-circulated accumulated steel stock in society denoted the full and true lifetime of steel. Based on the volume correlation model, the lifetime of steel was calculated for the total steel, low alloyed and special steel, and stainless steel in Sweden between 1898 and 2010. Previous studies on the lifetime of steel are based on experimental measurements and numerical calculations. The full lifetime of the total amount of steel from previous studies is 31 and 35 years for the years 2000 and 2006 respectively. Based on the volume correlation model the lifetime for the total steel amount, when assuming a full recovery of the material, was calculated as 34 and 37 years for these two years. This indicates that the lifetime of steel from the volume correlation model is in a similar range, but slightly higher, compared to previously reported data. The present results show that the model could be an alternative method to calculate the lifetime of steel and other recyclable materials on an annual basis. Results show that the lifetime of the total steel amount has continuously increased between 1975 and 2010. This indicates that the accumulated steel stock in society is still large enough to withstand the high collection rate of steel scrap. Furthermore, that there are as yet no lack of untapped resource of end-of-life steel scrap assets in Swedish society.

Characteristics of airborne Staphylococcus aureus (including MRSA) in Chinese public buildings.

The aim of this study was to evaluate the concentration and size distribution of airborne culturable Staphylococcus aureus (S. aureus) (including MRSA) in Chinese public buildings. Air samples were collected, using six-stage Andersen sampler from five different public buildings in one large Chinese community. The mean indoor concentrations of the total and respirable airborne S. aureus were 72 and 50 CFU/m3 in the general hospital, 72 and 49 CFU/m3 in the kindergarten, 76 and 52 CFU/m3 in the hotel, 84 and 57 CFU/m3 in the movie theater, and 55 and 40 CFU/m3 in the university classroom. Respirable S. aureus amounted to approximately 57–73 % of the total S. aureus concentrations. Mean total and respirable concentrations of airborne MRSA were 32 and 20 CFU/m3 in the general hospital, 20 and 13 CFU/m3 in the kindergarten, 23 and 16 CFU/m3 in the hotel, 33 and 20 CFU/m3 in the movie theater, and 24 and 17 CFU/m3 in the university classroom. Respirable MRSA amounted to approximately 61–72 % of the total MRSA concentrations. The ratios of indoor and outdoor concentration for airborne S. aureus and MRSA were more than 1.0 in all the investigated public buildings. The size distribution results showed relatively high collection rates on stage 4 (2.1–3.3 μm) for both airborne culturable S. aureus and MRSA regardless of the type of public buildings.

Estimating the amount of WEEE generated in South Korea by using the population balance model

We estimated the amount of waste electrical and electronic equipment (WEEE) generated in South Korea by using the population balance model (PBM) based on a lifespan distribution analysis. This is the first study to apply PBM to estimate WEEE generation in South Korea. The lifespan distribution analysis of electrical and electronic equipment (EEE) was based on the results of a questionnaire survey of 1000 households, which were analyzed with the Weibull distribution. As a result, we could estimate the domestic service lifespan and lifespan distribution shape parameter for eight selected products. Using the lifespan distribution analysis and other data, such as the shipment volume and the number of products owned by households, we estimated the amount of WEEE generated for the eight selected items from 2000 to 2020. We found that 1.2million air conditioners, 2.5million televisions, 1.3million microwave ovens, 1.2million kimchi refrigerators, 17.0million mobile phones, 1.7million refrigerators, 2.0million vacuum cleaners, and 1.4million washing machines were generated as WEEE in 2010. We also compared our WEEE estimates with the number of items collected through the official WEEE recycling program from 2003 to 2009 and found that in 2009 washing machines had the highest collection rate (28%) and air conditioners had the lowest rate (7%).

On the Throughput Capacity of Wireless Sensor Networks With Mobile Relays

In wireless sensor networks (WSNs), it is difficult to achieve a large data collection rate because sensors usually have limited energy and communication resources. Such an issue is becoming increasingly more challenging with the emerging of information-intensive applications that require high data collection rate. To address this issue, in this paper, we investigate the throughput capacity of WSNs, where multiple mobile relays are deployed to collect data from static sensors and forward them to a static sink. To facilitate the discussion, we propose a new mobile-relay-assisted data collection (MRADC) model. Based on this model, we analyze the achievable throughput capacity of large-scale WSNs using a constructive approach, which can achieve a certain throughput by choosing appropriate mobility parameters. Our analysis illustrates that, if the number of relays is less than a threshold, then the throughput capacity can be linearly increased with more relays. On the other hand, if the number is greater than the threshold, then the throughput capacity becomes a constant, and the capacity gain over a static WSN depends on two factors: 1) the transmission range and 2) the impact of interference. To verify our analysis, we conduct extensive simulation experiments, which validate the selection of mobility parameters and demonstrate the same throughput behaviors obtained by analysis.

A new one-pot method for the synthesis of Cu nanoparticles for low temperature bonding

We developed a new one-pot method for the synthesis of Cu nanoparticles capped with fatty acids and amines from an insoluble salt, such as Cu carbonate and Cu hydroxide, in ethylene glycol. This method could be completed within a short period of time and provides a high collection rate from inexpensive raw materials without impurities. The mean diameter of the Cu nanoparticles was controlled from 93 to 13 nm as the alkyl carbon number increased from C10 to C22. The same fraction of fatty acids and amines used for capping agents was suitable to obtain the minimum size of Cu nanoparticles. The thermal decomposition temperature of the capping layer was lower than 300 °C even in an inert atmosphere. Higher strengths of the Cu plates bonded by the Cu nanoparticles were achieved owing to the more densely packed sintered structures by the smaller Cu nanoparticles. The shear strength of the Cu plates bonded by the Cu nanoparticles was higher than 30 MPa which was the same level as for ordinary solders even though the process temperature of 300 °C was much lower than high-temperature solders. The minimum electrical resistivity of the sintered Cu nanoparticle film was 13 μΩ cm which was obtained after annealing at 300 °C.

Fine Particle Removal Performance of a Two-Stage Wet Electrostatic Precipitator Using a Nonmetallic Pre-Charger

ABSTRACT A novel two-stage wet electrostatic precipitator (ESP) has been developed using a carbon brush pre-charger and collection plates with a thin water film. The electrical and particle collection performance was evaluated for submicrometer particles smaller than 0.01∼0.5 μm in diameter by varying the voltages applied to the pre-charger and collection plates as well as the polarity of the voltage. The collection efficiency was compared with that calculated by the theoretical models. The long-term performances of the ESP with and without water films were also compared in tests using Japanese Industrial Standards dust. The experimental results show that the carbon brush pre-charger of the two-stage wet ESP had approximately 10% particle capture, while producing ozone concentrations of less than 30 ppb. The produced amounts of ozone are significantly lower than the current limits set by international agencies. The ESP also achieved a high collection rate performance, averaging 90% for ultrafine particles, as based on the particle number concentration at an average velocity of 1 m/sec corresponding to a residence time of 0.17 sec. Higher particle collection efficiency for the ESP can be achieved by increasing the voltages applied to the pre-charger and the collection plates. The decreased collection efficiency that occurred during dust loading without water films was completely avoided by forming a thin water film on the collection plates at a water flow rate of 6.5 L/min/m2. IMPLICATIONS Current two-stage electrostatic precipitators (ESPs) have several technical problems such as a drop in collection efficiencies by small-particle re-entrainment during rapping and corrosion of metallic electrodes of the ESPs by corrosive gases. This paper evaluates a novel two-stage ESP that uses a nonmetallic pre-charger and water film collection plates to avoid the above mentioned problems of other ESPs. This ESP can be used not only for industrial applications but also for residential purposes because it has a high removal performance for fine particles with low ozone generation and maintains its efficiency due to the continuous cleaning of the collection plates with water film.

An Analysis of Monopolistic and Competitive Take‐Back Schemes for WEEE Recycling

We study two prevailing types of take‐back schemes for electrical and electronic equipment waste recycling: monopolistic and competitive. We address key market and operating factors that make one scheme preferable to the other from the viewpoints of recyclers, manufacturers, and consumers. To this end, we model competitive decision making in both take‐back schemes as two‐stage sequential games between competing manufacturers and recyclers. Deriving and computing equilibria, we find that the competitive take‐back scheme often accomplishes a win–win situation, that is, lower product prices, and higher recycler and manufacturer profits. Exceptionally, recyclers prefer the monopolistic scheme when the substitutability level between the manufacturers' original products is high or economies of scale in recycling are very strong. We show that consolidation of the recycling industry could benefit all stakeholders when the economies of scale in recycling are strong, provided that manufacturer's products are not highly substitutable. Higher collection rates also render recycler consolidation desirable for all stakeholders. We also identify a potential free rider problem in the monopolistic scheme when recyclers differ in operational efficiency, and propose mechanisms to eliminate the discrepancy. We show that our results and insights are robust to the degree of competition within the recycling industry.

Cherenkov telescopes as optical telescopes for bright sources: today’s specialized 30-m telescopes?

Imaging Atmospheric Cherenkov Telescopes (IACTs) use large-aperture (~ 10 - 30 m) optical telescopes with arcminute angular resolution to detect TeV gamma-rays in the atmosphere. I show that IACTs are well-suited for optical observations of bright sources (V <= 8 - 10), because these sources are brighter than the sky background. Their advantages are especially great on rapid time-scales. Thus, IACTs are ideal for studying many phenomena optically, including transiting exoplanets and the brightest gamma-ray bursts. In principle, an IACT could achieve millimagnitude photometry of these objects with second-long exposures. I also consider the potential for optical spectroscopy with IACTs, finding that their poor angular resolution limits their usefulness for high spectral resolutions, unless complex instruments are developed. The high photon collection rate of IACTs is potentially useful for precise polarimetry. Finally, I briefly discuss the broader possibilities of extremely large, low resolution telescopes, including a 10" resolution telescope and spaceborne telescopes.

Discussion: Career Evaluation and the Decision Process for Plastic Surgery Graduates

I would offer an experiential perspective garnered from time spent in three different careers: a pure (however defined) academic position; a hybrid career within an academic group but a group conducted as a private practice corporation; and, finally, a current situation of half-time academic and halftime private practice. The article by Drs. Davison and Clemens has been distilled from a lecture series at their home institution, Georgetown University. The central tenet or hypothesis, if you will, is that one of the most important, if not the most significant, of the professional decisions of a plastic surgery resident is the career and job choice on graduation from one’s residency. Yet, to continue with iteration of the assumed underlying hypothesis, turnover in jobs and career choices in the early years of practice is high. The authors cite national statistics not for plastic surgery, but for physicians in general, and those numbers for plastic surgery may not be available, but personal observations would indicate that the premise is correct. The second element of that hypothesis, at least by implication, is that plastic surgery residents are ill-informed about the necessary prerequisites to arrive at the correct decision about career/job choice. This well-written exposition will address that deficiency quite well. Some points deserve emphasis. Position searches require substantial forward planning to a degree, in my opinion, not fully appreciated by many if not most residents. Besides the necessary time to locate and select (mutually) a position, a subsequent hiatus is also necessary to become credentialed, by hospitals, outpatient surgery centers, and insurance panels. In most instances, each facility or institution has its own credentialing requirements and process and, for reasons that I have not been able to divine, will contact and communicate with the medical school, residencies, and fellowships (if any), all of whom may be slow to respond. Licensure has similar requirements but, in addition, the state medical licensure board may meet infrequently, even quarterly. A hiatus of 3 or 4 months or longer is common and, by definition, occurs after contractual agreement (if not solo practice) between resident and employer/group. The authors list the two reasons why a practitioner may elect departure from a group practice in primary care. One is a poor cultural fit, and the other is compensation. What is a “poor cultural fit” with an established practice in plastic surgery? As outlined by the authors, these two reasons, fit and compensation, are intertwined. Thus, potential questions to be asked by the prospective hire (beyond what he or she will be paid) are: What is the underlying thrust of the practice, not always evident, toward plastic surgery? Is the emphasis predominately one of cosmetic surgery? If so, established referral patterns may dictate bypass of the group for reconstructive problems that signal in turn a longer duration to establish a practice. How is overhead allocated? Practice expenses are fixed (e.g., rent) or variable (e.g., salaries or supplies). If a disproportionate amount of overhead is assigned to the fixed category, including salaries, and these costs are divided equally among the partners, the high earners are rewarded (percentagewise) and the low earners are punished. Are the variable costs, also termed resource-based, divided on the basis of billings or collections? This factor and the one just described may be among the more common sources of misunderstanding and disagreement between a new signee and the group. Variable cost allocation on the basis of billings, which is one estimation of individual practitioner consumption of resources, may be inequitable, even highly inequitable, if a wide disparity exists in collection rates. For example, a senior partner with a mostly cosmetic practice will have a high ( 90 percent) collection rate; in contrast, the young reconstructive surgeon will have perhaps a 40 percent collection rate. Although total billings may be a more accurate reflection of the use of resources, overhead is paid from collections, and the young practitioner is penalized.

A Study of Appropriate Flow Rate Settings for Cell‐Free and Concentrated Ascites Reinfusion Therapy and Change of Cytokine Concentrations in Ascites

We examined appropriate flow rates for high collection rates of Total Protein (TP) and Albumin (Alb) and a change of IL-6 concentrations in the cell-free and concentrated ascites reinfusion therapy (CART) process. No significant changes were observed in IL-6 concentration in the ascites storage test and the circulatory stimulation test. However, it was confirmed that the quantity of IL-6 in the ascites decreased by means of filtration and concentration. In some cases, it quickly reached high concentration rates at a higher flow rate (200 mL/min) setting, but clogging or pressure increase has occurred in the hollow fiber filter. Therefore, it was concluded that a low flow rate (50 mL/min) setting was best and provides safer conditions for filtration and concentration in order to collect TP and Alb effectively and reuse it as autologous protein, which is the primary objective of CART.

Focus on test and measurement

Focus on test and measurement

Indicators of waste management efficiency related to different territorial conditions

The amount of waste produced and the control of separate collection are crucial issues for the planning of a territorial Integrated Waste Management System, enabling the allocation of each sorted waste fraction to the proper treatment and recycling processes. The present study focuses on assessing indicators of different waste management systems in areas characterized by different territorial conditions. The investigated case study concerns the municipalities of Emilia Romagna (northern Italy), which present a rather uniform socioeconomic situation, but a variety of geographic, urban and waste management characteristics. A survey of waste generation and collection rates was carried out, and correlated with the different territorial conditions, classifying the municipalities according to altitude and population density. The best environmental performances, in terms of high separate collection rate, were found on average in rural areas in the plain, while the lowest waste generation was associated with rural hill towns.

Measuring the status of stainless steel use in the Japanese socio-economic system

To reduce the amount of materials that are extracted from and emitted to the environment, reutilization and long-term use within our socio-economic system are important goals. From this perspective, the average number of times a material comes into use and the total average lifetime of a material are useful indicators for measuring the status of our material use. In general, multiple uses and long lifetime indicate effective and efficient material use. In this article, we estimate these usage and lifetime indicators for stainless steel (SS) for the Japanese socio-economic system and discuss the meanings of these indicators given its main alloying elements. The following conclusions are drawn: (1) Based on Japanese SS use in 2005, SS is estimated to be used 1.9–4.3 times in average over its entire life cycle depending on possible low and high collection rate scenarios of SS obsolete scrap. SS is estimated to be used for 19–100 years in average over its entire life cycle, under the low collection rate and short product lifetime (LCR&SPL) to high collection rate and long product lifetime (HCR&LPL) scenarios. (2) Some SS scrap is used for carbon and other alloyed steels (COAS) production. Although SS scrap that is recycled within COAS cycles no longer functions as SS, iron contained in SS does serve a function in COAS products, considering an elemental interpretation. Iron contained in SS is estimated to be used 3.2–6.8 times and for 56–170 years in average over its entire life cycle, under the LCR&SPL to HCR&LPL scenarios. (3) From the viewpoint of sustainable material use, estimated total average lifetime of SS is not considered to be satisfactory. More effective and efficient material use needs to be achieved through the improvement in collection rates of obsolete scrap and lifetimes of final products.

Trapped ion imaging with a high numerical aperture spherical mirror

Efficient collection and analysis of trapped ion qubit fluorescence is essential for robust qubit state detection in trapped ion quantum computing schemes. We discuss simple techniques of improving photon collection efficiency using high numerical aperture (N.A.) reflective optics. To test these techniques we placed a spherical mirror with an effective N.A. of about 0.9 inside a vacuum chamber in the vicinity of a linear Paul trap. We demonstrate stable and reliable trapping of single barium ions, in excellent agreement with our simulations of the electric field in this setup. While a large N.A. spherical mirror introduces significant spherical aberration, the ion image quality can be greatly improved by a specially designed aspheric corrector lens located outside the vacuum system. Our simulations show that the spherical mirror/corrector design is an easy and cost-effective way to achieve high photon collection rates when compared to a more sophisticated parabolic mirror setup.

Sedimentation processes in a coral reef embayment: Hanalei Bay, Kauai

Oceanographic measurements and sediment samples were collected during the summer of 2006 as part of a multi-year study of coastal circulation and the fate of terrigenous sediment on coral reefs in Hanalei Bay, Kauai. The goal of this study was to better understand sediment dynamics in a coral reef-lined embayment where winds, ocean surface waves, and river floods are important processes. During a summer period that was marked by two wave events and one river flood, we documented significant differences in sediment trap collection rates and the composition, grain size, and magnitude of sediment transported in the bay. Sediment trap collection rates were well correlated with combined wave-current near-bed shear stresses during the non-flood periods but were not correlated during the flood. The flood's delivery of fine-grained sediment to the bay initially caused high turbidity and sediment collection rates off the river mouth but the plume dispersed relatively quickly. Over the next month, the flood deposit was reworked by mild waves and currents and the fine-grained terrestrial sediment was advected around the bay and collected in sediment traps away from the river mouth, long after the turbid surface plume was gone. The reworked flood deposits, due to their longer duration of influence and proximity to the seabed, appear to pose a greater long-term impact to benthic coral reef communities than the flood plumes themselves. The results presented here display how spatial and temporal differences in hydrodynamic processes, which result from variations in reef morphology and orientation, cause substantial variations in the deposition, residence time, resuspension, and advection of both reef-derived and fluvial sediment over relatively short spatial scales in a coral reef embayment.

Continuous-flow laser synthesis of large quantities of iron oxide nanowires in solution

Large quantities of iron oxide nanowires are rapidly synthesized at room temperature bypulsed-laser (248 nm) ablation of iron powder under methanol. By introducing a stream ofmethanol, a continuous flow of nanoscale products is collected. Through control of the flowrate, and hence the residence time of the products within the growth vessel, theirmorphology can be controlled. At high collection rates a lamellate ‘nanobelt’ morphologyis observed, whereas at low collection rates nanowires dominate. Chemical andstructural characterization suggests that the as-synthesized products have thestoichiometry of the goethite [FeO(OH)] phase. Annealing at temperatures above400 °C crystallizes theproducts as hematite (α-Fe2O3).

Evaluation of Metal Toxicity in Chlorella kessleri from the Perspective of the Periodic Table

Abstract The toxicities of 33 metals (36 species of metal ions) in Chlorella kessleri were investigated and compared to several parameters such as ion radii, stability constants with several ligands, solubility products, and heats of formation (enthalpy). Although a universal parameter that could explain the toxicities of all of the metal ions was not identified, the Irving–Williams series and the HSAB (hard and soft Lewis acidity and basicity) are related to the toxicity of metal ions. With regard to aluminum group elements, the amount of free ion determines the toxicity. Metal absorption was also investigated, including its time dependence (transient absorption). The absorption (adsorption) of anionic species (oxoacid) is lower than that of cationic species which in some cases shows a high collection rate of over 90%. Furthermore, absorptivity varies during the different growth regimes of the cell. Among green alga, Chlamydomonas reinhardtii is much more resistant to metal toxicity than Chlorella kessleri. Intracellular distribution of zinc was also determined by using a zinc-fluorescent probe under a confocal laser microscope, and the result shows the intracellular distribution of pH could be an important factor for the intracellular distribution of zinc.

Improved Validation of Peptide MS/MS Assignments Using Spectral Intensity Prediction

A major limitation in identifying peptides from complex mixtures by shotgun proteomics is the ability of search programs to accurately assign peptide sequences using mass spectrometric fragmentation spectra (MS/MS spectra). Manual analysis is used to assess borderline identifications; however, it is error-prone and time-consuming, and criteria for acceptance or rejection are not well defined. Here we report a Manual Analysis Emulator (MAE) program that evaluates results from search programs by implementing two commonly used criteria: 1) consistency of fragment ion intensities with predicted gas phase chemistry and 2) whether a high proportion of the ion intensity (proportion of ion current (PIC)) in the MS/MS spectra can be derived from the peptide sequence. To evaluate chemical plausibility, MAE utilizes similarity (Sim) scoring against theoretical spectra simulated by MassAnalyzer software (Zhang, Z. (2004) Prediction of low-energy collision-induced dissociation spectra of peptides. Anal. Chem. 76, 3908-3922) using known gas phase chemical mechanisms. The results show that Sim scores provide significantly greater discrimination between correct and incorrect search results than achieved by Sequest XCorr scoring or Mascot Mowse scoring, allowing reliable automated validation of borderline cases. To evaluate PIC, MAE simplifies the DTA text files summarizing the MS/MS spectra and applies heuristic rules to classify the fragment ions. MAE output also provides data mining functions, which are illustrated by using PIC to identify spectral chimeras, where two or more peptide ions were sequenced together, as well as cases where fragmentation chemistry is not well predicted.

Evaluation of concurrent collection of in‐line filtered platelets and packed red blood cells by multicomponent apheresis with three last‐generation apparatuses

Multicomponent apheresis enables the collection and procession of different blood products in a single donation. Different apparatuses vary in terms of principle and efficiency. Knowledge of them is essential to analyse cost effectiveness. A total of 30 donors, well matched for baseline parameters, were randomly assigned to the concurrent collection of red blood cells (RBCs) and platelets (PLTs) with the Baxter Amicus (AM), the Haemonetics MCS plus (MCS+), and the Gambro Trima Accel (TA). The procedures were prospectively evaluated, focusing on yield, time, efficiency, citrate donor load and in vitro quality. PLT yield (x 10(11)/unit; mean +/- standard deviation) was 3.09 +/- 0.34 (AM), 2.53 +/- 0.35 (MCS+), 2.51 +/- 0.32 (TA). Absolute RBC mass (ml/unit; mean +/- standard deviation) was 177.4 +/- 2.7 (AM), 161.5 +/- 0.7 (MCS+), and 163.7 +/- 5.4 (TA). The programmed RBC collection target of 160-180 ml was reached by all instruments, whereas the programmed PLT yield of 3.0 x 10(11) was met satisfactorily by AM only. All units contained < 1 x 10(6) WBCs. In vitro RBC quality was equivalent among the systems. No significant differences were noted with collection efficiency, processed whole blood or citrate donor load. Owing to high collection and draw rates, the TA was the fastest of all the systems. The MCS+ had the longest donation/needle time and the highest PLT activation, but compensated with significantly lower draw and citrate infusion rates. The overall processing time was longest with the AM, as a result of manual procedures from donor disconnection to the final products. Multicomponent apheresis was performed safely and efficiently with all three instruments. There was no 'magic apparatus' as each system combined advantages and pitfalls for the diverse parameters evaluated.