High Circulation Rates Research Articles

Blood Vessels

Abstract: One of the primary target tissues for inflammatory and allergy mediators is the blood vessel, and cytokines have a variety of impacts on it. We describe the usefulness of isolated blood vessels immersed in organ baths as a valuable source of pharmacological data. Contractility assays provide strong potency and selectivity data on agonists, partial agonists, and competitive or noncompetitive antagonists; however, their use in the bioassay of vasoactive drugs is gradually being replaced by more advanced analytical techniques. The human umbilical vein, for instance, has been widely utilized to identify bradykinin B2 receptor ligands. Isolated segments of vascular tissue are highly reactive living tissues, particularly in terms of regulating gene products associated with inflammation (e.g., kinin B1 receptor). The venule’s extremely thin walls have the potential to burst due to their high volume. Venules allow blood to move into larger veins. Both veins and arteries have three layers in their walls. On the other hand, venous pressure is modest. Veins are less elastic and have thin walls, allowing them to maintain a high blood circulation rate. The venous system’s high capacitance enables it to store a significant amount of blood at comparatively low pressures, containing around 75% of the circulating blood at any given time. The veins’ one-way valves permit blood to move forward toward the heart through muscle contractions.

Assessment of experimental methods for measurements of the horizontal flow of fluidized solids under bubbling conditions

Dual fluidized bed systems are indispensable for future energy systems that require solids cycling between different atmospheres. However, controlling the residence time of solids in the reactor, which is crucial for controlling the heat and mass transfer of the fuel, is a significant challenge. This study investigates four experimental techniques to quantify the horizontal flow of solids fluidized under bubbling conditions: integral mass accumulation; differential mass accumulation; thermal tracing; and magnetic solids tracing. Integral mass accumulation entails collecting bed material using a defluidized box within a given time period. Differential mass accumulation measures the material accumulation rate in a section of the bed that is monitored using pressure measurements. Thermal tracing calculates the solids flow rate by solving the heat balance to match the temperature field captured by a thermographic camera. Magnetic solids tracing involves injecting a batch of magnetic tracer solids into the reactor and then measuring the residence time distribution using impedance coils.The experiments were conducted under down-scaled conditions that resemble large-scale operations with a length scaling factor of 0.12. For this study, three operational parameters were varied: the fixed bed height; the volumetric flow rate of the conveying air; and the fluidization velocity in the bed. The horizontal solids circulation rates achieved ranged from 1.7×10−4 to 10 kg/m·s, corresponding to 1.2×10−3 to 70 kg/m·s on a hot up-scaled basis, which is a relevant range to indirect biomass gasification in an industrial setting.The three selected operational parameters led to increases in the horizontal solids flow. While all four methods replicated the trends, quantitative variations in the measured circulation rates occurred due to the inherent characteristics of the methods. High circulation rates resulted in a continuous decrease in the solids inventory, leading to an underestimation of the circulation rate when using the integral mass accumulation method. The accuracy of the differential mass accumulation method relied on transient pressure measurements, which were less-effective at low solids flow rates. Conversely, the accumulation time required for pressure measurements was reduced at high circulation rates, resulting in uncertainties in the analysis. The accuracy of the thermal tracing method decreased drastically with higher solids circulation, resulting in an overestimation of the circulation rate. Moreover, low circulation rates adversely affected the accuracy of the magnetic solids tracing by producing barely discernible tracer concentration gradients.

Passive immunization against COVID-19 by anti-SARS-CoV-2 spike IgG in commercially available immunoglobulin preparations in severe antibody deficiency

Passive immunization against COVID-19 by anti-SARS-CoV-2 spike IgG in commercially available immunoglobulin preparations in severe antibody deficiency

Experimental study of key operating parameters effects on the characteristics of proton exchange membrane fuel cell with anode recirculation

Water management is essential to ensure high performance and stable operation of the proton exchange membrane fuel cell (PEMFC). However, little is known about water management in the hydrogen circulation anode (HCA) mode which can achieve high hydrogen utilization. In this work, the effects of hydrogen circulation rate, a key parameter of HCA mode, on water management and cell performance are experimentally investigated. In particular, transparent fuel cell and printed circuit board segmented fuel cell technologies are used to study the water distribution and the local current density distribution, respectively. Furthermore, the electrochemical properties and PEMFC stability at different hydrogen circulation rates are discussed in detail. The experimental results indicate that increasing the hydrogen circulation rate reduces liquid water in the cathode and anode flow channels, which can effectively alleviate the adverse effects of flooding on overall performance and cell stability. However, subsequent drying of the membrane and catalyst layer results in an increase in ohmic resistance and a decline in cell performance, especially at low current densities. The current density distribution shows that severe local flooding is likely to occur in the hydrogen and air outlet regions at a low hydrogen circulation rate. For a high hydrogen circulation rate, membrane drying will occur in some areas, especially near the hydrogen inlet. To achieve uniform current density distribution and high fuel cell performance, the hydrogen circulation rate should be increased with the load current.

Creative absorber design and optimization for CO2 capture with aqueous piperazine

The Texas Carbon Management Program is preparing a Front-End Engineering Design (FEED) of the PZASTM (Piperazine with the Advanced StripperTM) for CO2 capture at a natural gas combined cycle power plant in West Texas. This paper develops the absorber design for the capture system and studies the operational strategies of the absorber in response to ambient temperature swing. The design uses 2 absorber trains, and each train integrates absorption and a water-wash section in one column. Each column has a cross-section area of 174 m2 and consists of 3 sections of MellapakPlus® 252Y structured packing. Packing heights for each section are 3, 4.9, and 2.7 m from top to bottom. A pump-around intercooler applied at the bottom bed circulates solvent and eliminates the direct contact cooler. The baseline CO2 removal rate is 90% and will vary between 78% and 90% with ambient temperature. The system uses air cooling to eliminate cooling water usage. The water balance in the system will be managed by operating the water wash at a high circulation rate (1300 kg/h) to condense water during the night and make up for water loss during the day. The proposed design reduces the capital cost of the absorber column by minimizing the packing height and eliminating the direct contact cooler (DCC), and improves the energy cost by lowering the pump-around intercooling temperature and increasing the pump-around rate.

Surveillance of seasonal respiratory viruses among Chilean patients during the COVID-19 pandemic.

Surveillance of seasonal respiratory viruses among Chilean patients during the COVID-19 pandemic.

Ultra-Compact Microscale Heat Exchanger for Advanced Thermal Management in Data Centers

Abstract This study is focused on the experimental characterization of two-phase heat transfer performance and pressure drops within an ultracompact heat exchanger (UCHE) suitable for electronics cooling applications. In this specific work, the UCHE prototype is anticipated to be a critical component for realizing a new passive two-phase cooling technology for high-power server racks, as it is more compact and lighter weight than conventional heat exchangers. This technology makes use of a novel combination of thermosyphon loops, at the server-level and rack-level, to passively cool an entire rack. In the proposed two-phase cooling technology, a smaller form factor UCHE is used to transfer heat from the server-level thermosyphon cooling loop to the rack-level thermosyphon cooling loop, while a larger form factor UCHE is used to reject the total heat from the server rack into the facility-level cooling loop. The UCHE is composed of a double-side-copper finned plate enclosed in a stainless steel enclosure. The geometry of the fins and channels on both sides are optimized to enhance the heat transfer performance and flow stability while minimizing the pressure drops. These features make the UCHE the ideal component for thermosyphon cooling systems, where low pressure drops are required to achieve high passive flow circulation rates and thus achieve high critical heat flux values. The UCHE's thermal-hydraulic performance is first evaluated in a pump-driven system at the former laboratory of heat and mass transfer (LTCM)-Swiss Federal Institute of Technology of Lausanne, where experiments include many configurations and operating conditions. Then, the UCHE is installed and tested as the condenser of a thermosyphon loop that rejects heat to a pumped refrigerant system at Nokia Bell Labs, in which both sides operate with refrigerants in phase change (condensation-to-boiling). Experimental results demonstrate high thermal performance with a maximum heat dissipation density of 5455 (kW/m3/K), which is significantly larger than conventional air-cooled heat exchangers and liquid-cooled small pressing depth brazed plate heat exchangers. Finally, a thermal performance analysis is presented that provides guidelines in terms of heat density dissipations at the server- and rack-level when using passive two-phase cooling.

Reinforcement in the Aggregate: Partisan Newspaper Circulation and the Presidential Vote, 1900–1928

ABSTRACT While generally understood as an individual-level effect, we argue that reinforcement effects—or the strengthening of existing party loyalties through media exposure—might also play a role in shaping aggregate-level outcomes. Looking across eight presidential elections from 1900 to 1928, this study provides evidence that partisan newspaper circulation was significantly linked to two-party vote share at the county level. Counties with higher circulation rates of Republican dailies had a smaller percentage of votes cast for the Democratic presidential candidate, while a weaker positive association was found between the circulation of Democratic leaning dailies and Democratic vote in non-Southern counties. Some variance in this effect was observed across elections, with some evidence suggesting a weaker association between circulation and vote share as newspapers moved away from overtly partisan content toward a more professional tone. Further, some of the relationships were reciprocal with votes influencing partisan circulation. Results suggest that greater attention be given to the role of the political media environment and how citizens engage with it when understanding macro-level political outcomes.

Particle separation in cyclones of circulating fluidized bed systems

Circulating fluidized bed (CFB) plants are widely used in energy, petrochemicals, aluminum production (alumina firing), and other industrial sectors. The CFB technology is characterized by relatively high reactor velocity that exceed the transport velocity of medium-sized particles, and the presence of separators (mainly of the cyclone type) with a system for returning trapped particles to the reactor. This ensures a long residence time of the particles in the reaction zone, a high circulation rate, and a stable and relatively low temperature in the reactor. In fact, it is the cyclone capture efficiency that directly determines the multiplicity of circulation and the flow rate of circulating particles and their size characteristics. The report discusses the current state of development and methods for cyclones calculating. Data from our and foreign studies are reviewed and the dependence of the correction on the mass concentration of particles is proposed. A brief description of the test rigs and the results of our own studies of particle separation in cyclones are given. Experimental data on the effect of dust on the capture efficiency are presented in the form of a dependence of the relative entrainment of particles (1-efficiency) on the mass concentration of particles at the entrance to the cyclone. Entrainment is noticeably reduced when the concentration increases, as small particles are attracted by larger ones to the wall of the cyclone.

Reimagining career collections to increase usage and engagement

Purpose The purpose of this study is to describe a case study of building a career collection at an academic library and to assess the use of materials and the services provided to students and the career services office. Design/methodology/approach This study reviewed circulation statistics and COUNTER reports to identify usage of career services resources. Findings The major findings of this study indicated that items in the print career collection experienced higher circulation rate than items in the circulating collection at Lied Library. Originality/value The information and findings of this study can provide a background of services and information on how to build a career collection in an academic library that can be used as an example for other libraries interested in providing career services and/or collections.

High-Capacity Dual-Electrolyte Aluminum–Air Battery with Circulating Methanol Anolyte

Aluminum–air batteries (AABs) have recently received extensive attention because of their high energy density and low cost. Nevertheless, a critical issue limiting their practical application is corrosion of aluminum (Al) anode in an alkaline aqueous electrolyte, which results from hydrogen evolution reaction (HER). To effectively solve the corrosion issue, dissolution of Al anode should be carried out in a nonaqueous electrolyte. However, the main cathodic reaction, known as oxygen reduction reaction (ORR), is sluggish in such a nonaqueous electrolyte. A dual-electrolyte configuration with an anion exchange membrane separator allows AABs to implement a nonaqueous anolyte along with an aqueous catholyte. Thus, this work addresses the issue of anode corrosion in an alkaline Al–air flow battery via a dual-electrolyte system. The battery configuration consisted of an Al anode | anolyte | anion exchange membrane | catholyte | air cathode. The anolytes were methanol solutions containing 3 M potassium hydroxide (KOH) with different ratios of water. An aqueous polymer gel electrolyte was used as the catholyte. The corrosion of Al in the anolytes was duly investigated. The increase of water content in the anolyte reduced overpotential and exhibited faster anodic dissolution kinetics. This led to higher HER, along with a greater corrosion rate. The performance of the battery was also examined. At a discharge current density of 10 mA·cm−2, the battery using the anolyte without water exhibited the highest specific capacity of 2328 mAh/gAl, producing 78% utilization of Al. At a higher content of water, a higher discharge voltage was attained. However, due to greater HER, the specific capacity of the battery decreased. Besides, the circulation rate of the anolyte affected the performance of the battery. For instance, at a higher circulation rate, a higher discharge voltage was attained. Overall, the dual-electrolyte system proved to be an effective approach for suppressing anodic corrosion in an alkaline Al–air flow battery and enhancing discharge capacity.

Comparison of Isobutane/n-Butenes Alkylation over Y-Zeolite Catalyst in CSTR, Fixed Bed and Circulating Flow Reactors

Isobutane/olefin alkylation is an important route to obtain high-quality gasoline. There is an apparent interest to apply zeolite based catalysts for this process to eliminate large scale usage of liquid catalysts such as H2SO4 and HF. Solid catalysts require a specific reactor system design involving frequent catalyst regeneration and operation at low concentration of the olefin. The aim of this work was to compare different reactor types: CSTR, “once-through” fixed bed type and circulating flow reactors (CFR), which are typically considered as suitable options for industrial implementation. The experiments were done on decationated Y-zeolite catalyst. Different paraffin/olefin ratios, temperature and circulation rates were studied. Catalysts and process performance are discussed based on the catalyst lifetime and the alkylate octane number. Analysis of diffusion limitations in different reactor types and optimization of the circulation rate in CFR were done. It was found that isobutane alkylation in a circulating flow reactor shows approximately the same catalyst lifetime even at a high circulation rate not exhibiting any positive impact of back-mixing on this process. However, a circulating flow reactor has demonstrated a much better quality of alkylate with the research octane number higher by 4.9 points. Additional operational costs related to the reactor effluent recycle are fully covered by the alkylate quality improvement even at a high circulation ratio.

Comparative results of thyroid cryoablation in SHR and vistar rats

Introduction. Today, cryosurgery is considered as a promising minimally invasive approach to the treatment of benign nodules of thyroid gland. Blood circulation in the tissue can affect the effectiveness of cryoablation preventing decline of the temperature. This is true for the thyroid gland, which belongs to organs with a high blood circulation rate. The SHR rat can be used for modeling the processes of thyroid cryoablation in people with essential hypertension, which makes it possible to obtain calculated data on reaching the target freezing temperature in patients with arterial hypertension. Aim of the study – make a comparative assessment of histological characteristics of thyroid gland tissue in hypertensive SHR rats and normotensive Wistar rats after cryoablation. Materials and methods. In the experiments, SHR and Wistar rats weighing 250–280 g were used. Cryodestruction of the thyroid gland was carried out in intact animals and rats, which were administrated with a 0.1 % solution of propylthiouracil to induce diffuse thyroid hyperplasia. The operation was performed under general anesthesia. Cryotherapy was carried out for 40 s once on the left lobe of the thyroid gland using a copper cryoprobe, which was cooled to the temperature of liquid nitrogen. On day 21, the animals were taken out of the experiment; the thyroid gland were taken and used for histological studies. Results. It was found that at the site of cryotherapy in gland samples of animals of both lines on day 21, a cone-shaped zone of fibrosis was formed, in which the parenchyma of the gland was replaced by connective tissue with pronounced vascularization and insignificant lymphocytic-histiocytic infiltration. The mean area of fibrosis did not differ significantly between the groups of intact SHR and Wistar rats. After cryoablation of glands with administration of propylthiouracil, a decrease in the area of fibrotic changes was observed: in Wistar rats – by 2 times, in SHR rats – by 3–4 times. Conclusions. Parameters of blood circulation in arterial hypertension did not significantly affect the result of thyroid gland cryoablation in rats. However, after induction of tissue hyperplasia with propylthiouracil, an increase in gland resistance to cryodestruction is observed, which should be taken into account when choosing a cryotherapy regimen.

Young adult literature in translation: The state of research

The aim of the article is to examine the concept of young adult literature, provide its historical timeframe, identify its key components, and, finally, discuss young adult literature in translation by presenting the state of research on the topic. After analysing the concept of a young adult, the article moves on to provide a brief summary of adolescent fiction’s history, concluding that J. D. Salinger’s The Catcher in the Rye and S. E. Hinton’s The Outsiders largely contributed to the recognition of the genre. The paper mentions characteristic style choices employed by the authors of young adult fiction, the most prominent being the blend of registers or ‘code-switching’ between teen and adult speech, as acknowledged by Penelope Eckert and Chuck Wendig. Code-switching constitutes one of the main translation problems and is discussed at large in two compelling papers on the topic of young adult literature translation, namely Translating Young Adult Literature. The High Circulation Rate of Youth Language and Other Related Translation Problems in “The Catcher in the Rye” and “The Outsiders” by Saskia Tempert and Translating Young Adult Literature: Problems and Strategies. John Green`s “An Abundance of Katherines” by Loana Griguta. Both dissertations analyse the language of adolescent novels (in the twentieth and the twenty first century) and devise a list of strategies dedicated to adequately rendering English source versions into Dutch and Romanian, respectively. These writings indicate a growing interest in the field of young adult literature translation. The article expresses the hope that more scholars will elaborate on the topic.

Seroprevalence Investigation of Newcastle Disease in Rural Poultries of the Northern Provinces (Golestan, Gilan, and Mazandaran) of Iran.

Rural poultry farming is common in the Northern provinces. Similar to commercial poultry, rural poultry is susceptible to most infectious diseases. In addition, by increasing the density of poultry farming, the probability of disease incidences has been increased. Newcastle disease is the most highly infectious disease which is endemic in Iran and causes outbreaks among commercial and rural poultry every year. The present study aimed to investigate the prevalence and virus circulation of Newcastle disease among rural poultry in Northern provinces of Iran. In the current study, 70 villages in 3 provinces (20, 30, and 20 villages in Mazandaran, Golestan, and Gilan, respectively) and a total of 1,374 birds (600, 400, and 374 birds in Mazandaran, Golestan, and Gilan, respectively) were sampled. Each village was regarded as an epidemiological unit. In the present study, birds of 67 (96%) villages were positive (presence of antibodies against Newcastle disease virus), including 28 (93.3%), 19 (95%), and 20 (100%) villages in Golestan, Mazandaran, and Gilan, respectively. Moreover, out of 1,374 birds, 616 (45%) of them were seropositive against Newcastle disease virus with 242 (41%), 159 (39.8%), and 211 (56%) samples in Mazandaran, Golestan, and Gilan, respectively. According to the results of the current study, the seroprevalence rate was reported to be high in both villages and birds. Such a high seroprevalence rate was indicative of the continuous exposure of the rural poultry to Newcastle virus and high virus circulation rate in the mentioned provinces which could result in the dissemination of the disease to commercial farms. Consequently, the implementation of proper control and care programs (e.g., vaccination of native poultry) can facilitate the reduction of Newcastle disease prevalence.

Multivariate analysis of metabolic parameters and optimization of antibody production using high cell density hybridoma in hollow fiber bioreactors.

The relationships of manipulation of culture temperature and medium circulation rate on the metabolic parameters were regressed by multiple linear regression analysis in hollow fiber bioreactors (HFB). The high circulation rate could significantly enhance the oxygen consumption of the hybridoma cells and the medium's oxidation-reduction potential. A mildly hypothermic condition of 36°C and a circulation rate of 182.5mL/min could support the hybridoma had the maximal antibody titer of 60.75μg/mL for 20days. When the ammonium ion was 65ppm or lactate close to 2.6g/L, the medium was replaced to maintain the stable and healthy cells at the high cell concentration of 3.33 × 108/mL for continuous antibody production. Two serum-free media could be successfully applied to this perfusion system and maintain hybridoma growth and antibody production. The single-use HFBs could provide the advantages including high cell density, low shear stress, and continuous antibody production.

Effect of electrode compression and operating parameters on the performance of large vanadium redox flow battery cells

Studies in small cells of vanadium redox flow battery have shown electrode compression to have significant effect on the cell performance. However, the results are conflicting and the data have been obtained for very high electrolyte circulation rates. In the present study, experimental investigations have been conducted in vanadium redox flow battery cells of active area of 426 cm2 and 936 cm2 over a wide range of operating conditions typical of large cells and for electrode compressions of 20, 35, 50 and 70%. The influence of operating current density, electrolyte circulation rate and state of charge has been specifically studied for both cell sizes. Cell pressure drop studies have also been conducted. Results show that the beneficial effects of electrode compression are mostly nullified by the loss of permeability at current densities in the range of 30–60 mA cm−2. At higher current densities, intermediate compressions of 35 and 50% are found to be the most optimal. Low state of charge tolerance is found to be better for the larger cell than the smaller cell, presumably due to better convective transport of electrolyte through the electrode arising from higher pressure drop.

Experimental Study for Enhancement the Cooling System and Exhaust Gasses for Gasoline Automotive Engine Using Nano-Fluid.

Adding of nanomaterial to car radiator fluid for 4-stroke gasoline engine was investigated experimentally at different Nanofluid concentrations with different flow rates for variable car speeds and number of passengers. The fluid temperature and exhaust gases emissions have been carried out. Results demonstrate that the increasing of Nanofluid concentration and high fluid circulation rates can improve the heat transfer of the engine radiator response; also using Nanofluids reduces the CO and NOx emissions of the engine exhaust gasses, while the CO2 ratio has been increased.

Modeling of gasification reaction to produce activated carbon from pistachio shells in a spouted bed

A one-dimensional mathematical model has been developed to predict behavior of a spouted bed reactor during the gasification of char obtained from pyrolysis of pistachio shells leading to the production of activated carbons. The pores overlapping phenomenon is considered in the model with no auxiliary empirical correlation used. This model is capable of the prediction of BET surface area of the produced activated carbons besides the gas-solid hydrodynamics and distribution of gas and solid temperature and concentration in the bed. The results revealed that the one-dimensional model well predicts values for char burn-off, BET surface area, and bed temperature in gasification reactions in spouted bed reactor. This is due to the excellent mixing and high circulation rates of the materials inside a spouted bed which reduces radial distributions.

Assessment of Multilingual Collections in Public Libraries: A Case Study of the Toronto Public Library

Abstract
 Objective – The Toronto Public Library has been frequently identified as having an exemplary multilingual collection to serve the information needs of the most diverse population in Canada; however, there is no evidence or collection assessment information available in the literature to validate those claims. This research sought to gain an understanding of the current state of their multilingual collection and compare it to the most recent multicultural population demographics.
 Methods – This was a case study of the Toronto Public Library multilingual collection using data collected from their online public access catalogue in November 2017. Data was collected about all languages available, with English, French, and the 17 most spoken mother tongues explored in more detail. Language results from the Statistics Canada 2016 Census of Population were also collected. Data was used to calculate and compare the English, French, and language collections to the population of reported mother tongues spoken in Toronto.
 Results – It was found that the Toronto Public Library has items in 307 languages. While the collection comprises many languages, there is far more focus on official language items than any other language compared to the population in terms of number of items and variety of formats. All 17 non-official languages that were studied had fewer items proportionally available in the catalogue than the proportion of speakers with that mother tongue.
 Conclusion – The high circulation rates of the Toronto Public Library’s multilingual collection indicate that it has had some success in meeting the needs of its community. However, as the largest library system in Canada with a highly regarded multilingual collection and with many resources for collection development, the Toronto Public Library falls short of having a language collection that is proportional to the languages spoken within the community. While it may not be possible to have a multilingual collection that is entirely representative of the community, this study shows that libraries can use census data to monitor population shifts in order to be responsive to the information needs of their changing communities.