Pickup Efficiency Research Articles

Integration of information and optimization models for vehicle routing in urban areas

This paper is about efficient and reliable vehicle routing in urban areas. We enforce customer-oriented tour generation by provision and integration of time-dependent information models. Information models represent typical states of the traffic network in terms of time-dependent travel time data sets. In recent years, large amounts of telematics based traffic data have become available. Common optimization models are not capable of processing such data. Thus, we refer to a Data Mining approach that generates time-dependent information models by sophisticated filtering and aggregation of telematics based traffic data. The main focus is on the integration of different types of time-dependent information models into optimization models. Several information models and time-dependent vehicle routing heuristics are introduced and compared regarding data processing, computational effort and their impact on efficiency and reliability of pickup and delivery tours in urban areas.

Catching Proteins in Liquid Helium Droplets

An experimental approach is presented that allows for the incorporation of large mass-to-charge ratio selected ions in liquid helium droplets. It is demonstrated that droplets can be efficiently doped with a mass-to-charge ratio selected amino acid as well as with the much bigger m ≈ 12,000 amu protein cytochrome C in selected charge states. The sizes of the ion-doped droplets are determined via electrostatic deflection. Under the experimental conditions employed, the observed droplet sizes are very large and range, depending on the incorporated ion, from 10¹⁰ helium atoms for protonated phenylalanine to 10¹² helium atoms for cytochrome C. As a possible explanation, a simple model based on the size and internal energy dependence of the pickup efficiency is given.

Mathematical Model for the Sequestering of Chemical Contaminants by Magnetic Particles

A mathematical model is developed and implemented to characterize the pickup of various liquid chemical contaminants by polyethylene-coated magnetic particles. The model and its associated experimental and analytical protocols were applied to a wide range of liquid chemicals in order to gain insights into the physical basis for the pickup phenomenon. The characteristics of the pickup isotherms range between “ideal” and “nonideal” behaviors that are reflected in the mathematical model by a single parameter, α0, where α0=1 corresponds to ideal behavior and α0>1 corresponds to a departure from idealized behavior that is directly quantified by the magnitude of α0. The parameter α0 is also related to the efficiency of pickup, and since most isotherms observed in the study deviate from ideality, the high efficiency of pickup observed in these systems has been attributed in part to this deviation. The proposed model and its associated experimental and analytical protocols demonstrate great potential for the systematic evaluation of the uptake of chemical contaminants using magnetic particle technology.

Utilization of greenhouse effect for solar drying of cassava chips.

An indirect passive solar dryer was designed, constructed and tested. The dryer was designed to accommodate a total quantity of 45 kg and was tested by carrying out three experiments with fresh cassava chips of approximate sizes of 2.5, 3.0 and 3.5 cm. The highest temperature recorded during the experiments was 60.5°C. The average result shows that the 3.0 cm chips inside the drying chamber were dried from 65% (187% dry basis) to 10% (11% db) moisture content in 4 days, while the samples outside the chamber were dried to 11% (13% dry basis) in 6 days. This result shows that over thirty percent saving in drying time was achieved in the dryer compared to the open sun drying. The calculated drying efficiency and the Pick-up efficiency of the dryer are 31 and 58% respectively. The organoleptic quality test of the dried cassava chips showed that samples in the dryer retained their white colour, thus, indicating no mould growth. Key words: Cassava, chips, dryer, solar-drying, storage.

Construction and evaluation of rotary solar dryer for fish drying

Rotary solar dryer was developed and evaluated for fish drying. People preferred dried prawns in diet in off seasons. Dried prawns are in high demand in the market and hence Prawns (Kolambi) were selected as drying material. Time required for reducing the moisture content from 75 per cent to final moisture content 16 per cent for sun drying werecompared with solar drying. Evaluation parameters were collection efficiency, system drying efficiency, pick-up efficiency, moisture ratio and drying rate. Maximum temperature observed inside the dryer at 13 pm was 57 0C whereas maximum ambient temperature observed was 35.30C at 12:54 pm and solar irradiation was 600 W/m2 at 11:14am. It was observed in total five slots of trays, averagedrying efficiency for salted fish was 14 per cent and unsalted fish was 11 per cent. Inside the drying chamber, increasing profile temperature was observed from bottom tray to upper ray. Humidity inside dryer was minimum as compared to outside condition. Overall collection efficiency was found as 70.97 %. Salted fish inside the dryer required 8 hours to dryprawn’s up to 16.15 per cent while unsalted fish required 15 hours to reach moisture content up to 15.15 per cent in open condition. Unsalted fish inside the dryer took slightly higher time to reach up to moisture content 16.91 per cent whereas salted in open condition required 13 hours to dry up to 16.37 per cent.

Low cost solar dryer for fish

Prawns (Kolambi) were selected as drying material in low cost solar dryer (LCSD). Time required for reducing the moisture content from 75 to 16% were observed in open sun drying and solar drying for its comparison. Salted fish inside the dryer required 8 h in order to dry prawns up to 16.15% while unsalted fish required 15 h to reach moisture content up to 15.15% in open condition. Overall collection efficiency was found as 70.97%. Average drying efficiency for salted fish was 14% and unsalted fish was 11% whereas pickup efficiency for salted and unsalted fish was found as 10 and 9% respectively. Salted prawns were found most liked for its colour and texture than unsalted solar dried sample in sensory evaluation. Unsalted prawns sample dried in solar dryer was overall accepted, while traditionally open sun dried sample was least liked for its colour and texture. The value of F is calculated as 1.98 during the sensory evaluation. The economic cost of solar dryer was compared with mechanical drying for beneficial to local fishermen. The cost of LCSD in Rs. 1700/- is affordable to poor fisherman comparing to other costly mechanical dryer. Local fisherman could recover solar dryer cost within the period of 0.19 years by adopting solar drying technology. Key words: Collection efficiency, system drying efficiency, pick-up efficiency, economics.

Storm-Water Management Using Street Sweeping

Although street sweeping is commonly regarded as a cost-effective storm-water best management practice, there is little quantitative evidence that street sweeping directly improves runoff water quality. In this paper, several previous street sweeping studies were reevaluated using statistical power analysis. Two-group, independent-sample one-sided t -test power analyses were performed using log-transformed event mean concentrations (EMCs) of total suspended solids, suspended sediment concentration or chemical oxygen demand. The effect size between the two groups was estimated using the sweepers’ pickup efficiency, which showed that the failure to detect the difference between mean EMCs of the two sample groups (i.e., unswept and swept groups) is likely due to limited sample numbers. Too few samples, which also resulted in a high coefficient of variation, were analyzed to detect the likely difference between swept and unswept observations. In addition, the temporal gap between street sweeping and subsequen...

Evaluation of street sweeping effectiveness as a stormwater management practice using statistical power analysis

Although street sweeping is commonly regarded as a cost-effective stormwater best management practice, there is little quantitative evidence that street sweeping directly improves runoff water quality. In this paper, several previous street sweeping studies were re-evaluated using statistical power analysis. Two-group, independent-sample one-sided t-test power analyses were performed using log-transformed event mean concentrations (EMCs) of total suspended solids, suspended sediment concentration or chemical oxygen demand. The effect size between the two groups was estimated using the sweepers' pick-up efficiency, which showed that the failure to detect the difference between mean EMCs of the two sample groups (i.e., unswept and swept groups) is likely due to limited sample numbers. Too few samples, which also resulted in a high coefficient of variation, were analysed to detect the likely difference between swept and unswept observations. In addition, the temporal gap between street sweeping and subsequent storm events was not controlled to improve statistical power.

Laparoscopic ovum pick-up followed by in vitro embryo production for the reproductive rescue of aged goats of high genetic value

The efficiency of laparoscopic ovum pick-up (LOPU) followed by in vitro embryo production (IVEP) in the propagation of aged goats with poor reproductive performance was evaluated in the present study. Follicular development was stimulated in donor goats with 80 mg follicle-stimulating hormone and 300 IU equine chorionic gonadotrophin administered 36 h before LOPU. In addition, goats were heat synchronised with intravaginal sponges containing 60 mg medroxyprogesterone acetate for 10 days and a luteolytic injection of 125 microg cloprostenol 36 h before sponge removal and LOPU. Following in vitro maturation (IVM), oocytes were fertilised in vitro with frozen-thawed semen produced using the egg yolk-free Bioxcell extender (IVM, L'Aigle, France). The average number of follicles aspirated (17.9 +/- 8.0 per goat), oocytes recovered (15.7 +/- 8.4 per goat) and cleavage after IVM/in vitro fertilisation followed by a short 24-h in vitro culture in modified synthetic oviduct fluid medium (72 +/- 7%) were similar to results reported previously by our group and others in younger goats. A total of 296 embryos was transferred into 50 heat-synchronised recipients, of which 40 became pregnant (80%) and 38 progressed all the way to term, delivering 86 live kids. The present study indicates that LOPU-IVEP can be used successfully to extend the reproductive life of valuable goats that have acquired difficulties becoming pregnant by artificial insemination after multiple kiddings.

Cargo pick-up from engineered loading stations by kinesin driven molecular shuttles

Exploiting biological motors ex vivo to transport and distribute cargo with high spatial control, as done by cells, requires that we learn how molecular shuttles (microtubules propelled by kinesins) can pick up cargo from defined surface regions (loading stations). The main challenge of building microfabricated cargo loading stations is to adjust the sum of non-covalent interactions such that the station stably holds on to the cargo under static conditions, but allows for transfer when a gliding microtubule collides with station-bound cargo and starts to pull on it. Successful pick-up of cargo could be observed using biotin-anti-biotin interactions and hybridized oligonucleotides. The effect of different tethering chemistries on the efficiency of cargo pick-up was tested.

Experimental study of regenerative desiccant integrated solar dryer with and without reflective mirror

An indirect forced convection with desiccant integrated solar dryer has been built and tested. The main parts are: a flat plate solar air collector, a drying chamber, desiccant bed and a centrifugal blower. The system is operated in two modes, sunshine hours and off sunshine hours. During sun shine hours the hot air from the flat plate collector is forced to the drying chamber for drying the product and simultaneously the desiccant bed receives solar radiation directly and through the reflected mirror. In the off sunshine hours, the dryer is operated by circulating the air inside the drying chamber through the desiccant bed by a reversible fan. The dryer is used to dry 20 kg of green peas and pineapple slices. Drying experiments were conducted with and without the integration of desiccant unit. The effect of reflective mirror on the drying potential of desiccant unit was also investigated. With the inclusion of reflective mirror, the drying potential of the desiccant material is increased by 20% and the drying time is reduced. The drying efficiency of the system varies between 43% and 55% and the pick-up efficiency varies between 20% and 60%, respectively. Approximately in all the drying experiments 60% of moisture is removed by air heated using solar energy and the remainder by the desiccant. The inclusion of reflective mirror on the desiccant bed makes faster regeneration of the desiccant material.

Gas sensor measurement system capable of sampling volatile organic compounds (VOCs) in wide concentration range

A gas sensor measurement system has been developed by using a vapor-generating bubbler, analyte-diluted delivery lines and a detection chamber. The bubbler with a perforated disk design permits to pick up analyte vapor with fixed efficiency under a carrier flow rate of 0.5–100 sccm. The pickup efficiency was modulated logarithmically by varying the bubbler temperature. The practically controllable range in acetone flux was nearly three orders of magnitude through the variation of the carrier flow rate, and an order of magnitude by the use of the bubble temperature, independently. The generated vapor was diluted efficiently through a cascading two-step process which leads to homogeneous mixing up to the flow ratio of dilution:carrier = 500:0.25, and then delivered into a small-gapped planar detection chamber operated at room temperature. The newly-designed planar chamber induces fast equilibrium and high local concentration on a sensor surface, thus resulting in a short detection time and a higher response magnitude. From measuring chemoresistive responses of carbon black-polymer composites upon exposure to acetone analyte, the measurement system was confirmed to be reliably applicable to a wide concentration range of from 3.7 ppm to 10.7%.

Development of an active solar crop dryer: design analysis and performance evaluation

The design analysis and performance evaluation of an active solar crop dryer was undertaken by drying marched cassava. The drying rate, system drying, collector and pick-up efficiencies were 1.6kg/day (14%/day), 9%, 46% and 29% respectively. Comparatively, the drying rate for sun drying was 0.9kg/day. The collector efficiency compared very well to the designed value of 48% and may not need further improvement. The pick-up efficiency also compared well with typical averages for this dryer type. The drying rate and system drying efficiency indicate the need for further development of this dryer. Prediction equations were developed from the results of measured differences in collector, dryer and ambient air temperatures plotted on graphs and applying regression. Keywords : solar crop dryer, performance evaluation, prediction equations, ambient air temperature Botswana Journal of Technology Vol. 14(2) 2005: 32-37

58 EFFICIENCY OF OVUM PICKUP AND EMBRYO PRODUCTION IN VITRO IN CLONED CATTLE

The reproductive performance of cloned cattle was investigated by assessing the efficiency of transvaginal ultrasound-guided ovum pickup (OPU) and embryo production in vitro. Fetal fibroblasts from the endangered species, German Blackpied Cattle, had been used for nuclear transfer to produce three live cloned offspring (Lucas-Hahn et al. 2002 Theriogenology 57, 433). In the three cloned animals at 12–20 months of age, OPU was performed once per week and the total number of collected oocytes was recorded. In the case of Blondie, the procedure was terminated due to too small ovaries associated with insufficient function. Oocytes suitable for IVF were matured in vitro for 24 h and fertilized in vitro with the semen of a fertile bull. Oocytes derived from abbatoir ovaries were processed in parallel as controls. Embryos were in vitro-cultured in SOFaaBSA medium. Cleavage and developmental rates up to the morula/blastocyst stage were recorded in all groups. Statistical significance was tested using ANOVA and the Student-Newman-Keuls test. The results are presented in Table 1. Embryos from clones had lower cleavage and blastocyst rates compared to those derived from abattoir oocytes. However, results may have been confounded by potential OPU effects. Some of the blastocysts produced from Blacky (n = 5) and Paula (n = 2) were transferred to recipients. Two pregnancies resulted from the Paula transfers. The two male calves were delivered normally. After the completion of this experiment, all three cloned animals were artificially inseminated, became pregnant, delivered healthy calves, and are pregnant again at present. Further studies are needed to explore the fertility of cattle derived from somatic cloning. Table 1. OPU and in vitro embryo production in cloned cattle

Experimental investigation of forced convection and desiccant integrated solar dryer

An indirect forced convection and desiccant integrated solar dryer is designed and fabricated to investigate its performance under the hot and humid climatic conditions of Chennai, India. The system consists of a flat plate solar air collector, drying chamber and a desiccant unit. The desiccant unit is designed to hold 75 kg of CaCl 2-based solid desiccant consisting of 60% bentonite, 10% calcium chloride, 20% vermiculite and 10% cement. Drying experiments have been performed for green peas at different air flow rate. The equilibrium moisture content M e is reached in 14 h at an air flow rate of 0.03 kg/m 2 s. The system pickup efficiency, specific moisture extraction rate, dimensionless mass loss, mass shrinkage ratio and drying rate are discussed in this paper.

The effects of twisting and type of aspiration needle on the efficiency of transvaginal ultrasound-guided ovum pick-up in cattle.

The effects of twisting and type (single- or double-lumen) of aspiration needle on the efficiency of transvaginal ultrasound-guided ovum pick-up (US-guided OPU) were investigated in cattle. The first study using slaughterhouse ovaries revealed that twisting of the needle during follicle aspiration improved the oocyte recovery rate without deleterious effects on the attachment of cumulus layers. Vacuum pressure affected the oocyte recovery and cumulus attachment, regardless of the needle type. The needle type did not affect the oocyte recovery or cumulus attachment with an optimized vacuum pressure. In the second study, US-guided OPU was performed in live cows using two types of needles with a vacuum pressure of 75 mmHg. The needle type did not affect the oocyte recovery or cumulus attachment of the recovered oocytes. The results revealed that twisting of the needle is effective in follicle aspiration, and suggested that a single-lumen needle is as useful as a double-lumen needle for US-guided OPU in cattle.

Dynamic Monitoring of the Dust Pickup Efficiency of Vacuum Cleaners

Dynamic Monitoring of the Dust Pickup Efficiency of Vacuum Cleaners

Dynamic monitoring of the dust pickup efficiency of vacuum cleaners.

This study evaluated a new method that uses an optical aerosol photometer for dynamically monitoring dust pickup efficiency during vacuuming. In the first stage of this study the new method was compared with built-in dirt sensors installed by vacuum cleaner manufacturers. Through parallel testing it has been shown that the widely available built-in dirt sensors are not sensitive enough to register small (< 53 microm) dust particles. Therefore, only the optical photometer was used in the rest of the experiments of this study to monitor the dust pickup efficiency while the vacuum cleaner was operated with different nozzles on clean and soiled carpet and vinyl sheet flooring. This method also was used to monitor dust pickup efficiency when vacuuming carpets originating from lead-contaminated homes. The dust pickup efficiencies obtained with the optical aerosol photometer have been compared with the surface lead concentrations found during different stages of cleaning. Results indicate that the dust mass concentration registered with the optical aerosol photometer at the nozzle outlet correlates well with the dust mass collected in the vacuum cleaner filter bag and with the surface lead level. Therefore, dynamic dust pickup monitoring can provide valuable information about the efficiency of cleaning when a vacuum cleaner is used. This suggests that a small aerosol photometer similar to a light-scattering smoke detector would be beneficial in vacuum cleaners used for cleaning surfaces contaminated with leaded dust and biological particles (including allergens).

Role of lower hybrid turbulence in surfing acceleration at perpendicular shocks

The mechanism for excitation of lower hybrid waves by shock surfing pickup ions is proposed. It is based on the modified two‐stream instability. The stationary distribution function of the surfing particles is calculated, which can serve as a driver for the excitation of the lower hybrid waves. The instability growth rate is found, as well as conditions under which waves have enough time to grow while being convected to the shock front together with the solar wind flow. The excited waves are responsible for the velocity diffusion of the surfing particles in the direction opposite to the acceleration. These particles are detrapped from the shock front and escape from the shock surfing acceleration. The flux of escaping particles is calculated in the quasi‐linear approximation, and it is shown to decrease quickly with the mass of the accelerated particles. This result can provide a possible explanation of Voyager observations, which indicate that the injection efficiency of interstellar pickup into the acceleration process at the solar wind termination shock increases significantly for heavy ions in comparison with hydrogen.

Test methods for evaluating the filtration and particulate emission characteristics of vacuum cleaners.

The overall filtration efficiency of a vacuum cleaner traditionally has been tested by placing the vacuum cleaner in a test chamber and measuring aerosol concentrations at the chamber inlet and outlet. The chamber test method was refined and validated in this study. However, this chamber test method shows an overall filtration efficiency of close to 100% for most of the industrial vacuum cleaners and for most of the newly developed household vacuum cleaners of midprice range or higher because all these vacuum cleaners have a high-efficiency particulate air (HEPA) or other highly efficient filter installed at the exhaust. A new test method was therefore developed through which the vacuum cleaner was probed in various internal locations so that the collection efficiency of the individual components could be determined. For example, the aerosol concentration upstream of the final HEPA filter can thus be measured, which permits one to estimate the life expectancy of this expensive component. The probed testing method is particularly suitable for field evaluations of vacuum cleaners because it uses compact, battery-operated optical particle size spectrometers with internal data storage. Both chamber and probed tests gave the same results for the aerosol filtration efficiency. The probed testing method, however, also gives information on the performance of the individual components in a vacuum cleaner. It also can be used to determine the dust pickup efficiency and the degree of reaerosolization of particles collected in the vacuum cleaner.