scholarly journals Spiral Vibration Cooler for Continual Cooling of Biomass Pellets

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1060
Author(s):  
David Žurovec ◽  
Lucie Jezerská ◽  
Jan Nečas ◽  
Jakub Hlosta ◽  
Jan Diviš ◽  
...  
Keyword(s):  
Cooling System ◽  
Negative Impact ◽  
Air Flow ◽  
Important Process ◽  
Cooling Process ◽  
Cooling Systems ◽  
Technical Problems ◽  
Insight Into ◽  
Vibrating Feeder

Cooling is an important process during the production of pellets (as post-treatment). The pellet cooling process significantly impacts the quality of the pellets produced and the systematic use of energy. However, the cooling systems currently in use sometimes encounter technical problems, such as clogging of the perforated grids (sieves), the discharge hopper, or pellet degradation may occur. Therefore, a prototype of a new pellet cooling system using a vibrating feeder was tested. The aim of the study is to present a new variation of pellet cooling system using spiral vibration cooler as a possible solution next to a counterflow cooler. The presented system was tested (critically evaluated and discussed) in two design variants. The first variant consists in cooling by chaotic movement of the pellets. The second is then in combination with the chaotic movement of the pellets together with the action of intense air flow using specially placed air hoses. All tests involved pelletization of rapeseed straw. It was found that both cooling system variants could, realistically, be used. However, the variant with an intense air flow was more energy-intensive, a factor which is, however, offset by the higher quality of the pellets. No negative impact of vibrations to pellets quality was occur. Studies provide insight into new usable technologies that do not reduce the efficiency of the process as a result of grate clogging.

Perimeter Cooling Unit and Localized Row-Based Cooling Unit Transient Air Flow Effects Modeling and Characterization in Data Centers

2015 ◽  
Author(s):  
Tianyi Gao ◽  
James Geer ◽  
Bahgat G. Sammakia ◽  
Russell Tipton ◽  
Mark Seymour
Keyword(s):  
Thermal Management ◽  
Data Center ◽  
Data Centers ◽  
Cooling System ◽  
Air Flow ◽  
Cooling Systems ◽  
Dynamic Thermal Management ◽  
Hybrid Cooling ◽  
Cooling Unit ◽  
Cooling Air

Cooling power constitutes a large portion of the total electrical power consumption in data centers. Approximately 25%∼40% of the electricity used within a production data center is consumed by the cooling system. Improving the cooling energy efficiency has attracted a great deal of research attention. Many strategies have been proposed for cutting the data center energy costs. One of the effective strategies for increasing the cooling efficiency is using dynamic thermal management. Another effective strategy is placing cooling devices (heat exchangers) closer to the source of heat. This is the basic design principle of many hybrid cooling systems and liquid cooling systems for data centers. Dynamic thermal management of data centers is a huge challenge, due to the fact that data centers are operated under complex dynamic conditions, even during normal operating conditions. In addition, hybrid cooling systems for data centers introduce additional localized cooling devices, such as in row cooling units and overhead coolers, which significantly increase the complexity of dynamic thermal management. Therefore, it is of paramount importance to characterize the dynamic responses of data centers under variations from different cooling units, such as cooling air flow rate variations. In this study, a detailed computational analysis of an in row cooler based hybrid cooled data center is conducted using a commercially available computational fluid dynamics (CFD) code. A representative CFD model for a raised floor data center with cold aisle-hot aisle arrangement fashion is developed. The hybrid cooling system is designed using perimeter CRAH units and localized in row cooling units. The CRAH unit supplies centralized cooling air to the under floor plenum, and the cooling air enters the cold aisle through perforated tiles. The in row cooling unit is located on the raised floor between the server racks. It supplies the cooling air directly to the cold aisle, and intakes hot air from the back of the racks (hot aisle). Therefore, two different cooling air sources are supplied to the cold aisle, but the ways they are delivered to the cold aisle are different. Several modeling cases are designed to study the transient effects of variations in the flow rates of the two cooling air sources. The server power and the cooling air flow variation combination scenarios are also modeled and studied. The detailed impacts of each modeling case on the rack inlet air temperature and cold aisle air flow distribution are studied. The results presented in this work provide an understanding of the effects of air flow variations on the thermal performance of data centers. The results and corresponding analysis is used for improving the running efficiency of this type of raised floor hybrid data centers using CRAH and IRC units.

scholarly journals Modelling of secondary cooling system with a distributed architecture, using Coloured Petri nets

2019 ◽  
Author(s):  
Carlos Alberto Rojas Gallardo ◽  
Ruth Edmy Cano Buitrón ◽  
José Isidro García Melo
Keyword(s):  
Petri Nets ◽  
Mechanical Engineering ◽  
Structural Model ◽  
Cooling System ◽  
Coloured Petri Nets ◽  
Secondary Cooling ◽  
Cooling Systems ◽  
Control Structures ◽  
Distributed Structure

Currently, cooling systems adjust their control structures with the objective of satisfying the demands of different applications. In consequence, the centralized structure frequently used in this type of applications has evolved towards a distributed structure to increase the quality of response to the current demands of the market. However, a correct specification of this type of structure demands several challenges to be overcome, such as the management of specialized resources, integration methods, coordination of independent subsystems, clarity of information, and increased dynamics of systems. This study addressed the modelling of the secondary cooling system that is located in the refrigeration laboratory of the School of Mechanical Engineering at the Universidad del Valle in Cali, Colombia. A distributed structure was considered by the integration of several modelling tools, such as Coloured Petri nets. Using the structural model and successive refinements, the system behaviour representation was obtained.

scholarly journals Preliminary experimental of GPU immersion-cooling

2019 ◽  
Vol 93 ◽  
pp. 03003 ◽  
Author(s):  
Nugroho Agung Pambudi ◽  
Husin Bugis ◽  
Ilham Wahyu Kuncoro ◽  
Nova Dany Setiawan ◽  
Miftah Hijriawan ◽  
...  
Keyword(s):  
Cooling System ◽  
Dielectric Strength ◽  
Water Cooling ◽  
Cooling Process ◽  
Liquid Cooling ◽  
Immersion Method ◽  
Cooling Systems ◽  
Technology System ◽  
Immersion Cooling ◽  
High Dielectric

A typical information technology system takes around 40% of the total energy used in cooling the system. There are three major classifications of cooling system and they are: water cooling, close loop liquid cooling, and immersion cooling systems. Immersion cooling has been observed to be the latest trend in cooling systems for IT devices. It is a cooling procedure that is carried out through the immersion of all computer components in a dielectric coolant. This research examined the cooling process of GPU using this immersion method. Mineral oil, because of its high dielectric strength, is used as a medium fluid. The temperature difference between the use of fan and immersion cooling was then measured using a benchmark software. The result showed that the immersion cooling produced a lower GPU temperature compared to the conventional fan. The working temperature of the GPU with the use of immersion method was 70°C while it was 80°C with the conventional fan method.

Coping With Stuttering

2014 ◽  
Vol 24 (2) ◽  
pp. 58-68 ◽  
Author(s):  
Eric Swartz ◽  
Farzan Irani ◽  
Rodney Gabel
Keyword(s):  
Quality Of Life ◽  
Mixed Methods ◽  
Speech Therapy ◽  
Negative Impact ◽  
Mixed Methods Approach ◽  
Positive Effects ◽  
Lower Severity ◽  
Qualitative Responses ◽  
Insight Into

Purpose: The purpose of this research was to gain a deeper understanding about coping strategies by adults who stutter (AWS). Methods: A mixed methods approach was used to gather responses from 61 participants in response to a questionnaire with forced choice and open-ended questions. Participants were recruited via speech-language pathologists who forwarded the questionnaire to present and past clients who stutter. Results: Successful coping with stuttering had a positive correlation with a lower stuttering severity. The following themes where indicative of successful coping with stuttering: (1) living your life with stuttering, (2) managing stuttering with no negative impact, and (3) positive effects and speech therapy and techniques on stuttering. Unsuccessful coping with stuttering was described as: (1) avoidance, (2) negative impact on life, (3) treatment did not work, and (4) coping is difficult. Conclusions: The findings from this study indicated that AWS with a lower severity of stuttering cope better with their stuttering. Qualitative responses provided insight into how AWS perceive successful and unsuccessful coping with stuttering and how that impacts their overall quality of life.

scholarly journals Vulvovaginal Candidiasis: A Current Understanding and Burning Questions

2020 ◽  
Vol 6 (1) ◽  
pp. 27 ◽  
Author(s):  
Hubertine M. E. Willems ◽  
Salman S. Ahmed ◽  
Junyan Liu ◽  
Zhenbo Xu ◽  
Brian M. Peters
Keyword(s):  
Reproductive Tract ◽  
Negative Impact ◽  
Vulvovaginal Candidiasis ◽  
Female Reproductive Tract ◽  
Current State ◽  
Child Bearing ◽  
Causative Agents ◽  
Insight Into ◽  
A Current

Candida albicans, along with other closely related Candida species, are the primary causative agents of vulvovaginal candidiasis (VVC)—a multifactorial infectious disease of the lower female reproductive tract resulting in pathologic inflammation. Unlike other forms of candidiasis, VVC is a disease of immunocompetent and otherwise healthy women, most predominant during their child-bearing years. While VVC is non-lethal, its high global incidence and profound negative impact on quality-of-life necessitates further understanding of the host and fungal factors that drive disease pathogenesis. In this review, we cover the current state of our understanding of the epidemiology, host response, fungal pathogenicity mechanisms, impact of the microbiome, and novel approaches to treatment of this most prevalent human candidal infection. We also offer insight into the latest advancements in the VVC field and identify important questions that still remain.

Family Visitation and Its Relationship to Parental Stress Among Jailed Fathers

2018 ◽  
Vol 98 (6) ◽  
pp. 738-759 ◽  
Author(s):  
Jamie S. Martin ◽  
Shannon Womer Phaneuf
Keyword(s):  
Parental Stress ◽  
Negative Impact ◽  
Self Report ◽  
Report Data ◽  
Quantitative Analyses ◽  
Self Report Data ◽  
The Relationship ◽  
Incarcerated Fathers ◽  
Insight Into

This study explores the relationship between jail visitation with children and levels of parental stress among a sample of jailed fathers. Quantitative analyses of the self-report data reveal that jailed fathers experienced stress related to parenthood regardless of whether they had visits from their family. However, the type of stress varied, with fathers who had family visits reporting stress directly related to the visitation, while fathers who did not have visits noted more generalized parental stress. The findings provide insight into the type and quality of incarcerated fathers’ contact with their children and factors that influence the number of visits they receive. The negative impact of the lack of contact visits is also discussed.

scholarly journals The course of depression in late life: a longitudinal perspective

2020 ◽  
Vol 29 ◽  
Author(s):  
Alejandro de la Torre-Luque ◽  
Jose Luis Ayuso-Mateos
Keyword(s):  
Old Age ◽  
Negative Impact ◽  
Late Life ◽  
Late Life Depression ◽  
Symptom Trajectories ◽  
Old Age Depression ◽  
Subclinical Symptoms ◽  
Insight Into ◽  
Course Of Depression

Abstract Depression in old age deserves special attention in view of the fact of progressive population ageing, because of the way in which depression and risk factors interact in this period of life and the particularly negative impact of late-life depression on health and quality of life. This editorial aims to provide some insight into longitudinal aspects of depression in old age. Depression may follow varying trajectories (e.g. episode emergence, recurrence) across the lifespan. Late-life depression is not an exception. A symptom-based approach is presented as an appropriate research method to study the predictors and course of affective syndromes in old age. Findings from our studies on depressive symptom trajectories in old age revealed that participants with a course of unremitting elevated symptoms showed the highest levels of loneliness across the trajectory groups and that participants with subclinical symptoms also showed higher levels of loneliness than their counterparts with a minimal-symptom course trajectory. This highlights the need to address loneliness as a way of dealing with depression in old age.

Research of mold cooling process optimization for production of expanded polystyrene with the application of experimental measurements on the test form

2021 ◽  
Vol 13 (8) ◽  
pp. 168781402110410
Author(s):  
Ján Rusinko ◽  
Petr Baron ◽  
Anton Panda ◽  
Marek Kočiško
Keyword(s):  
Cooling System ◽  
Expanded Polystyrene ◽  
Mold Cavity ◽  
Experimental Measurements ◽  
Thermal Imager ◽  
Water Cooling ◽  
Cooling Process ◽  
Produce Water ◽  
Quality Of Products

An important step in the production cycle of pressing the expanded polystyrene is cooling of the mold and the molding. The paper describes the execution and analysis of experimental measurements in order to identify the influence of the cooling system on the quality of products produced by the technology observed. For the purpose of the experiment, a test mold with specific properties of the mold parts of the mold cavity was designed and manufactured. By means of the measuring circuit, the knowledge of the course of temperatures in the mold cavity during the pressing cycle was obtained. At the same time, the temperature distribution on the moldings and in the mold was monitored by means of a thermal imager. Two press cycles, with and without water cooling, were performed in course of the tests. Subsequently, the quality of the test pieces produced was checked. Based on the experiments conducted, the parameters influencing the water-cooling process of the mold for the production of expanded polystyrene have been identified. A significant element of the water-cooling system, which affects the quality of products and the technological process, is the application of spray nozzles – their location, orientation, and density. In order to optimize the cooling process observed, a multiple-nozzle spray head has been designed to produce water mist as a tool for more efficient distribution and application of the coolant.

scholarly journals Solar Thermal Panels for Small-Medium Scale Air Cleaners in Major Cities

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Francisco J. Arias ◽  
Salvador De Las Heras
Keyword(s):  
Mass Flow ◽  
Cooling System ◽  
Air Flow ◽  
Solar Thermal ◽  
Air Purification ◽  
Small Scale ◽  
Cooling Systems ◽  
Air Mass ◽  
Medium Scale ◽  
Air Cleaners

Air quality in major cities is reaching worrisome levels across the planet owing to large-scale industrialization. As a result, air purification systems are becoming a fertile and emerging field for research. Here, consideration is given to the use of a small-medium scale air purification system for cities using a kind of solar thermal panels by inducing local convective currents intended to be used in parks, housing estates, or similar urban places providing a local improvement of the quality of the air. The main difficulty which arose when attempting to use these convective currents is that the upward flow of hot air, which has been cleaned from contaminant particles during its upward travel, must be returned back to the ground. To accomplish this, air must be cooled during the travel in order to obtain an effective buoyancy. Several possible solutions have been proposed in the past, for example, the use of a dedicated cooling system as is the use of water spraying systems which could be an attractive option for large towers. However, for small-medium scale air cleaners, dedicated spraying cooling systems are out of question either because of the requirement of water flow or because of the high local humidity generated which can be uncomfortable for humans. One possible solution could be taking advantage of vertical panels in which a side of the panel is permanently irradiated and the other is permanently in the shadow; in this way, heating and cooling could be performed eliminating the need for specialized cooling systems, and although the effective buoyancy—and then the purified air mass flow—of such a system is considerably reduced, nevertheless, it could still be acceptable for local small-scale applications. Utilizing a simplified physical model, the effective buoyancy and attainable air mass flow were calculated. It is shown that for a small panel of 5 m-height or thereabouts, an air flow per unit of width ∼0.4 kg/s is attainable, and for a 10 m-height panel, an air flow per unit of width 0.6 kg/s is attainable. Computational fluid dynamics simulations were performed which agree with the analytical results within ±30 %.

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