Effects Of Pack Sizes Research Articles

(Digital Presentation) Using Simulations to Determine the Effects of the Lithium-Ion Battery Pack Sizes on Performance of Electric Vehicles

Internal combustion engine (ICE) vehicles have a longer driving range with a full tank of gas than lithium-ion battery-powered electric vehicles (EVs). Alongside having a higher purchase cost and a lack of charging infrastructure, the range of EVs is a large deterrent to potential buyers. One solution to increasing the range of EVs is using a battery pack with a higher capacity. However, increasing the capacity typically involves an increase in lithium-ion battery cells, which leads to a higher weight, higher vehicle cost, lower energy efficiency, and higher battery charging time. In addition, regenerative braking recovers the vehicle's kinetic energy which is related to speed and weight. To find the optimal battery pack size, a numeric road test simulation can be used to determine how battery pack size affects energy efficiency, driving range, charging time, and cost. This is more optimal than a real-life road test since inconsistent variables like traffic conditions and weather can be controlled. This paper applies work-energy mathematic modeling of an electric vehicle under different EPA dynamometer driving schedules to investigate the problem proposed above, using an EV model with 21700 type lithium-ion cells. In addition, total vehicle weight, motor efficiency, wheel sizes/weight, and the weight of passengers will also be considered. The simulation revealed that when the total vehicle weight reaches a certain point, it can regenerate significant kinetic energy back to the battery pack to increase the range. Figure 1

Investigation of the influence of gravel stuffing in an open drill on the productive characteristics of the well

The negative consequences of sand production from the formation into the wellbore during the operation of wells with unstable rocks are characterized. A highly effective method of preventing sand from entering the well from the formation is the use of gravel packs, which are used in Ukraine and abroad. The types of gravel packs, the conditions for their application, the choice of the diameter of gravel grains for creating gravel pack are given. The types of gravel pack installation are considered depending on the geological and technical conditions of the reservoir. Calculations have been performed using Schlumberger's PipeSim software to assess the effect of gravel pack size and permeability on the performance specification of a gas well. Based on the research results, graphical de-pendences of gas flow rates in the presence of gravel pack on the permeability of the gravel pack at its various thicknesses have been constructed and analyzed. It has been found that the gas flow rate increases with an increase in the thickness of the gravel pack in the considered interval of its variation up to 0.9 m. The effect of the thickness of the gravel pack on the gas flow rate increases with an increase in its permeability. Based on the results of statistical processing of the calculated data using the least-squares method, the optimal values of the gravel pack permeability for various values of its thickness have been determined. The optimal values of the thickness and permeability of the gravel pack have been determined, beyond which the value of the gas flow rate practically does not change. The calculation of the pressure distribution along the bore of a gas well in the presence of gravel pack with certain optimal values of its permeability and thickness is performed. Using the PipeSim software, the influence of the de-gree of relative formation penetration on the productivity of a gas well in the presence of gravel packing has been investigated for determining certain optimal values of permeability and thickness of gravel packing.

Power allocation smoothing strategy for hybrid energy storage system based on Markov decision process

The hybrid energy storage system (HESS) in electric vehicle (EV) requires power allocation for optimal performance. Recent researches show that the Markov decision process (MDP) provides promising characteristics for the energy management. However, the power fluctuation, which is rarely considered, can significantly affect the performance of HESS. The paper adopts the bilinear interpolation to smooth the MDP-based strategy. In this way, the power fluctuation can be mitigated, meanwhile the computation cost is not greatly increased. Given the battery and the ultracapacitor, two types of DC/DC converters are employed and the model of the HESS including the battery capacity degradation is introduced. Considering the energy loss and the energy reserve in the HESS, the reward function is built. Utilizing the cumulative reward function, the effect of ultracapacitor pack size on the performance of power allocation is analyzed in detail, the appropriate ultracapacitor size can be obtained further. Simulation results show that MDP strategy with the bilinear interpolation can not only reduce the energy loss by 5–10%, but also prolong the battery cycle life. Finally, the experimental workbench is built. The master-slave strategy is utilized to achieve the power allocation and DC/DC converter control. The proposed strategy is verified by the experimental results.

Effect of packing size on packed bubble column hydrodynamics

The present article focuses on the hydrodynamics of gas-liquid flow through a packed bubble column (PBC) reactor. Typically used in heterogeneously catalyzed gas-liquid reactions, such reactors employ a stationary packing of solid particles (catalyst) through which gas and liquid phases flow concurrently upwards. Designing the reactor to operate in a regime where the overall reaction rate is independent of mixing and mass transfer phenomena is crucial, and an important part of the design is the choice of the packing particle size, DP. It is well known that liquid-solid mass transfer and intraparticle (void) diffusion limitations drive the choice of the largest acceptable mean particle diameter. In the present work, we provide a condition for smallest acceptable mean particle size based on the consideration of gas-liquid mass transfer. Using experiments in a 10” diameter PBC apparatus and computational fluid dynamics (CFD) simulations, we demonstrate that this condition is related to a balance between bubble buoyancy and surface tension and is given by DP>Kσ/β2ρlg with K≈1.6 and β≈0.84.

Fear or food \u2013 abundance of red fox in relation to occurrence of lynx and wolf

Apex predators may affect mesopredators through intraguild predation and/or supply of carrion from their prey, causing a trade-off between avoidance and attractiveness. We used wildlife triangle snow-tracking data to investigate the abundance of red fox (Vulpes vulpes) in relation to lynx (Lynx lynx) and wolf (Canis lupus) occurrence as well as land composition and vole (Microtus spp.) density. Data from the Swedish wolf-monitoring system and VHF/GPS-collared wolves were used to study the effect of wolf pack size and time since wolf territory establishment on fox abundance. Bottom-up processes were more influential than top-down effects as the proportion of arable land was the key indicator of fox abundance at the landscape level. At this spatial scale, there was no effect of wolf abundance on fox abundance, whereas lynx abundance had a positive effect. In contrast, at the wolf territory level there was a negative effect of wolves on fox abundance when including detailed information of pack size and time since territory establishment, whereas there was no effect of lynx abundance. This study shows that different apex predator species may affect mesopredator abundance in different ways and that the results may be dependent on the spatiotemporal scale and resolution of the data.

Effect of pack size and materials on condom properties - Information from manufacturers

Most condoms, especially those purchased by international aid agencies, are packed in square aluminium foil packs. The alternative rectangular packs use less packing material, and are more compact to ship and store. Polymer packs, which do not contain an aluminium foil layer, offer the potential of easier re-cycling and reduced embodied energy.This article presents data originally generated by condom manufacturers that shows the difference in physical properties of condoms packed in different materials and different shapes. Tensile properties measured by an independent laboratory are also included for one manufacturer's product.It is concluded that there is no evidence that the plastic packs, or rectangular packs, provide inferior protection to the condom.

The effect of relatedness and pack size on territory overlap in African wild dogs

BackgroundSpacing patterns mediate competitive interactions between conspecifics, ultimately increasing fitness. The degree of territorial overlap between neighbouring African wild dog (Lycaon pictus) packs varies greatly, yet the role of factors potentially affecting the degree of overlap, such as relatedness and pack size, remain unclear. We used movement data from 21 wild dog packs to calculate the extent of territory overlap (20 dyads).ResultsOn average, unrelated neighbouring packs had low levels of overlap restricted to the peripheral regions of their 95% utilisation kernels. Related neighbours had significantly greater levels of peripheral overlap. Only one unrelated dyad included overlap between 75%-75% kernels, but no 50%-50% kernels overlapped. However, eight of 12 related dyads overlapped between their respective 75% kernels and six between the frequented 50% kernels. Overlap between these more frequented kernels confers a heightened likelihood of encounter, as the mean utilisation intensity per unit area within the 50% kernels was 4.93 times greater than in the 95% kernels, and 2.34 times greater than in the 75% kernels. Related packs spent significantly more time in their 95% kernel overlap zones than did unrelated packs. Pack size appeared to have little effect on overlap between related dyads, yet among unrelated neighbours larger packs tended to overlap more onto smaller packs’ territories. However, the true effect is unclear given that the model’s confidence intervals overlapped zero.ConclusionsEvidence suggests that costly intraspecific aggression is greatly reduced between related packs. Consequently, the tendency for dispersing individuals to establish territories alongside relatives, where intensively utilised portions of ranges regularly overlap, may extend kin selection and inclusive fitness benefits from the intra-pack to inter-pack level. This natural spacing system can affect survival parameters and the carrying capacity of protected areas, having important management implications for intensively managed populations of this endangered species.

The physical and numerical modeling of sand production and gravel pack in oil wells by designing and manufacturing the machine and presenting a relation estimating sand production rate

This research studies the effect of gravel pack size on sand production by designing and manufacturing a machine and a numerical model to simulate sand and gravel pack. This machine and the numerical model make it possible to test different rock along with various fluids under different stress in order to simulate the production of sand and gravel pack.PFC3D software is applied to create this numerical model. The numerical model consists of sand from 0.22 to 1.1 mm and gravel pack from 3.5 to 4.76, 4.76 to 9.9 to 12.6 and 12.6 to 16.8 mm and the physical model holds gravel from 9 to 4.76 and 4.76 to 9.25. The results from modeling demonstrated that sand is produced the least in the numerical model using gravel from 3.5 to4.76 mm and sand is produced less in the physical model containing gravel pack ranging from 4.76 to 9 mm and the fluid left more output discharge. Moreover, the outcomes from physical modeling proved that as time drags on, the fluid production rate got reduced and then reached to a fixed amount after placing gravel pack. So, it is suggested that gravel pack from 9mm to 4.76mm is more suitable from the viewpoints of fluid production rate and prevention of sand production. Based on dimensional analysis and the results from numerical modeling in a condition without gravel pack, a relation is concluded to estimate sand production rate.

The pack size effect: Influence on consumer perceptions of portion sizes

Larger portions as well as larger packs can lead to larger prospective consumption estimates, larger servings and increased consumption, described as 'portion-size effects' and 'pack size effects'. Although related, the effects of pack sizes on portion estimates have received less attention. While it is not possible to generalize consumer behaviour across cultures, external cues taken from pack size may affect us all. We thus examined whether pack sizes influence portion size estimates across cultures, leading to a general 'pack size effect'. We compared portion size estimates based on digital presentations of different product pack sizes of solid and liquid products. The study with 13,177 participants across six European countries consisted of three parts. Parts 1 and 2 asked participants to indicate the number of portions present in a combined photographic and text-based description of different pack sizes. The estimated portion size was calculated as the quotient of the content weight or volume of the food presented and the number of stated portions. In Part 3, participants stated the number of food items that make up a portion when presented with packs of food containing either a small or a large number of items. The estimated portion size was calculated as the item weight times the item number. For all three parts and across all countries, we found that participants' portion estimates were based on larger portions for larger packs compared to smaller packs (Part 1 and 2) as well as more items to make up a portion (Part 3); hence, portions were stated to be larger in all cases. Considering that the larger estimated portions are likely to be consumed, there are implications for energy intake and weight status.

Opposing effects of group size on reproduction and survival in African wild dogs

For cooperative breeders, we hypothesize that the effects of group size on reproduction and survival might run in opposition if the benefits of grouping cannot be shared without cost. We tested this hypothesis by examining relationships between group size, survival, and reproduction in African wild dogs (Lycaon pictus), cooperative hunters with highly cohesive packs within which reproduction is monopolized by the dominant male and female. The production and survival of pups are known to increase with increasing pack size, but the effect of pack size on adult survival has not been examined previously. Data from 366 individuals over a period of 6 years showed that the survival of adults decreased with increasing pack size, with a 25% difference between the largest and smallest packs after controlling for the effects of age, sex, social status, year of study, and pack identity. Several tests confirmed that undetected dispersal is unlikely to have produced this pattern. These results suggest that cooperative breeding in wild dogs cannot be fully explained by mutual direct benefit, thus reinforcing the prior inference that kin selection plays an important role in the evolution of their cooperation. The results also weaken support for the hypothesis that wild dogs are extinction prone due to group-level Allee effects. More broadly, the relationship of effects of group size on survival and reproduction might be predicted by considering whether cooperation yields benefits that accrue to all group members (e.g., through cooperative vigilance) or benefits that must be apportioned to individuals (e.g., through cooperative hunting).

The adaptive value of morphological, behavioural and life‐history traits in reproductive female wolves

Reproduction in social organisms is shaped by numerous morphological, behavioural and life-history traits such as body size, cooperative breeding and age of reproduction, respectively. Little is known, however, about the relative influence of these different types of traits on reproduction, particularly in the context of environmental conditions that determine their adaptive value. Here, we use 14 years of data from a long-term study of wolves (Canis lupus) in Yellowstone National Park, USA, to evaluate the relative effects of different traits and ecological factors on the reproductive performance (litter size and survival) of breeding females. At the individual level, litter size and survival improved with body mass and declined with age (c. 4-5 years). Grey-coloured females had more surviving pups than black females, which likely contributed to the maintenance of coat colour polymorphism in this system. The effect of pack size on reproductive performance was nonlinear as litter size peaked at eight wolves and then declined, and litter survival increased rapidly up to three wolves, beyond which it increased more gradually. At the population level, litter size and survival decreased with increasing wolf population size and canine distemper outbreaks. The relative influence of these different-level factors on wolf reproductive success followed individual > group > population. Body mass was the primary determinant of litter size, followed by pack size and population size. Body mass was also the main driver of litter survival, followed by pack size and disease. Reproductive gains because of larger body size and cooperative breeding may mitigate reproductive losses because of negative density dependence and disease. These findings highlight the adaptive value of large body size and sociality in promoting individual fitness in stochastic and competitive environments.

Spatio-temporal overlap between Yellowstone bison and elk - implications of wolf restoration and other factors for brucellosis transmission risk

1. In the Greater Yellowstone Ecosystem, bison Bison bison and elk Cervus canadensis nelsoni act as hosts for Brucella abortus. The presence of B. abortus within wildlife populations is an important conservation issue because of the risk of brucellosis transmission from wildlife to cattle. 2. We investigated conditions facilitating contact between bison (40–60% seroprevalence) and elk on a shared winter range in the Madison headwaters area of Yellowstone National Park. We evaluated the effects of snow pack, season, elk and bison population sizes, and wolf Canis lupus predation risk on the degree of spatial overlap between bison and elk from 1991 to 2006. 3. Sixty-eight per cent of 10 093 independent elk observations occurred within the known bison wintering range, 29% occurred within the distribution of bison within the winter range at the time of sampling and 14% occurred within 100 m of bison. Spatial overlap between bison and elk measured across these three spatial scales increased with week of the season, snow pack, and on days when wolves were within the same drainage area as elk, but decreased with cumulative levels of wolf predation risk. 4. Wolves contributed to immediate, short-term responses by elk that increased spatial overlap with bison, but longer-term responses to wolves resulted in elk distributions that reduced spatial overlap with bison. Spatial overlap increased through the winter and peaked when late-term abortion events and parturition occurred for bison. 5. Synthesis and applications. Despite this high level of association, elk exposure to B. abortus in the Madison headwaters (2–4%) was similar to those in free-ranging elk populations that do not intermingle with bison (1–3%), suggesting that B. abortus transmission from bison-to-elk under natural conditions is rare. Our results suggest that risk-driven elk behavioural responses to wolves are unlikely to have important disease implications. Management of brucellosis in greater yellow stone ecosystem elk populations should focus on reducing elk-to-elk transmission risk and, wherever possible, curtailing practices that increase elk density and group sizes during the potential abortion period.

Small pack size imposes a trade-off between hunting and pup-guarding in the painted hunting dog Lycaon pictus

The painted hunting dog or African wild dog, Lycaon pictus, is one of the most endangered large carnivores in Africa, with extinction predicted within a few decades if their dramatic decline is not stopped. It has recently been hypothesized that because of their constraining need for helpers, group size was of major importance in obligate cooperative breeding species, and that the resulting likely existence of a threshold number of adults could create an Allee effect, increasing the group extinction risk. One example where the importance for a critical number of adults may have major repercussions for painted hunting dogs concerns baby-sitting, or pup-guarding, a behavior typical of obligate cooperative breeders. We propose that, as forgoing this behavior is costly because pup guards have the potential to decrease pup mortality, its use is costly too, especially in small packs, because helpers are strongly needed for their cooperative foraging (hunting, protecting the kill and bringing back food to the pups). We present a simple model showing how pup-guarding imposes a cost because it implies that less food per hunt is brought back to more individuals at the den. We complete these analyses with empirical tests of the effect of pack size on the probability of pup-guarding, from field data from the Hwange population in Zimbabwe. Our model, as well as our 5 years of empirical data, both suggest a critical threshold at a size of about five individuals. Key words: African wild dog conservation, Allee effect, cooperative hunting, inverse density dependence, Lycaon pictus, painted hunting dog, pup-guarding. [Behav Ecol 13:20–27 (2002)]

PAEDIATRIC SELECTIONBritish Medical Journal (2001) K. Hawton, E. Townsend & J. Deeks. Effects of legislation restricting pack sizes of paracetamol and salicylate on self poisoning in the United Kingdom: Before and after study. Vol. 322, pp. 1203–1207.

PAEDIATRIC SELECTIONBritish Medical Journal (2001) K. Hawton, E. Townsend & J. Deeks. Effects of legislation restricting pack sizes of paracetamol and salicylate on self poisoning in the United Kingdom: Before and after study. Vol. 322, pp. 1203–1207. - Volume 6 Issue 4

Effects of legislation restricting pack sizes of paracetamol and salicylate on self poisoning in the United Kingdom: before and after study

Objective: To evaluate the effects on suicidal behaviour of legislation limiting the size of packs of paracetamol and salicylates sold over the counter.Setting: UK population, with detailed monitoring of data...

Effect of packing size on chomatographic separation of catechin compounds in Green Tea

EGCG (Epigallocatechin Gallate), one of the catechin compounds abundant mainly in green tea, has chemopreventive effects against carcinogenesis. The extract at 50 ‡C water from the powder of green tea was partitioned with chloroform and ethyl acetate. The resulting solution was further purified on three different columns, 4.6x250 mm (40/63 mm), 4.6x250 mm (15 mm), 3.9x300 mm (10 mm), in order to separate EGCG among catechin compounds from green tea. In a given packing size, the composition of the binary mobile phase, water and acetonitrile, with 0.1% acetic acid was changed to operate in optimized experimental conditions. In a packed column of 40/63 mm packing, catechin compounds were not well separated. With packing sizes of 15 and 10 mm, the resolution of EGCG among catechin compounds was better, and maximum injection volume to separate EGCG purely was 100 and 480 ml, respectively. The study on the effect of packing size may be utilized for preparative chromatographic separation.

Packed bed performance: Effect of packing size and shape

Packed bed performance: Effect of packing size and shape

Personal Equipment Design for Low Coal Mines

This paper presents the results of three studies investigating alternative designs for personal equipment carried by low seam coal miners. The first part reports on an evaluation of a coiled cap-lamp cord designed to reduce the incidence and severity of snagging and catching accidents. The second part reports on the effect of battery pack size and weight on speed of human locomotion. The last part describes a study designed to assess the effect of various configurations of retroreflective material affixed to miner's outer garments on detection in a simulated mine environment.

Time Base Errors in Video Tape Packs

This is a study of time base errors in video tape packs. The tape is viscoelastic. If a wound pack is stored at a constant temperature or subjected to environmental temperature cycles, the stresses relax and the tape creeps. Consequently, inelastic strains in the tape during playback cause distortion in the pictures. Time base error is a measure of inelastic longitudinal strain in the tape at playback. In this paper a mathematical model is developed to predict the effect of storage time, winding pattern, and pack size on time base error. Both the tape and hub are assumed elastic under hydrostatic loading and viscoelastic in shear. A four element fluid model is used for the tape and a Maxwell fluid model is used for the hub. Some comparison with experiments shows reasonable correlation.

A Model of the effect of the distribution of liquid on liquid hold-up in a packed bed and a new concept of static hold-up

An analysis is given of the effect of column diameter, packing size and bed depth on the hold-up through the parameters of the distribution of liquid i