Experimental Study of a Set of Integrated Cross-Media Heat Exchangers (iCMHXs) for Liquid Cooling in Desktop Computers

2020 ◽  
Author(s):  
Gargi Kailkhura ◽  
Raphael Mandel ◽  
Amir Shooshtari ◽  
Michael Ohadi
Keyword(s):  
Heat Exchangers ◽  
Experimental Studies ◽  
Single Layer ◽  
Post Processing ◽  
Liquid Cooling ◽  
Tube Bank ◽  
Cross Media ◽  
First Case ◽  
Desktop Computers

Abstract The present study is an experimental investigation of a set of five additively-manufactured compact, lightweight, low-cost, air-to-water cross-media heat exchangers suitable for liquid cooling applications in desktop computers, among other applications. The heat transfer between the two fluids is facilitated by solid metallic wires arranged in a staggered tube-bank configuration, in direct contact with both fluids separated by polymer walls. Since the liquid flows externally over the wires instead of flowing inside the tubes in conventional tube-bank fin heat exchangers, smaller wires can be used in iCMHXs, resulting in lighter and more efficient units. The additively-manufactured iCMHX units are post-processed using a conformal polyurethane sealant. The units are experimentally studied in two case studies based on their post-processing techniques. The experimental studies include instrumentation calibration as well as uncertainty analysis. The first case study considers three geometrically identical iCMHX units sharing the same post-processing method. The overall iCMHX performances characterized by the thermal and hydrodynamic parameters, such as thermal resistance and pressure drop for both waterside and airside, are compared. Their experimental results are also compared to 2D CFD predictions. To provide probable reasoning behind the differences in the comparisons, a second case study is then carried out by experimentally investigating two iCMHX units but with variable post-processing approaches such as by using a thinned sealant and by using a single layer of sealant.

Experimental Study of a Set of Integrated Cross-Media Heat Exchangers for Liquid Cooling in Desktop Computers

2021 ◽  
Author(s):  
Gargi Kailkhura ◽  
Raphael Kahat Mandel ◽  
Amir H Shooshtari ◽  
Michael Ohadi
Keyword(s):  
Experimental Study ◽  
Heat Exchangers ◽  
Liquid Cooling ◽  
Cross Media ◽  
Desktop Computers

scholarly journals Assessment of Ground Regeneration around Borehole Heat Exchangers between Heating Seasons in Cold Climates: A Case Study in Bialystok (NE, Poland)

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4793
Author(s):  
Joanna Piotrowska-Woroniak
Keyword(s):  
Heat Exchangers ◽  
Experimental Studies ◽  
Heat Pumps ◽  
Cold Climate ◽  
Ne Poland ◽  
North Eastern ◽  
Recorded Data ◽  
Source Of Information

Based on the experimental studies, the process of ground regeneration around the borehole loaded with brine-water heat pumps working exclusively for heating purposes in the period of four consecutive heating seasons in a cold climate was presented. The research was conducted in north-eastern Poland. The aim of the work is to verify the phenomenon of thermal ground regeneration in the period between heating seasons on the basis of the recorded data and to check whether the ground is able to regenerate itself and at what rate. It was noticed that the ground does not fully regenerate, especially during heating seasons with lower temperatures. In the analyzed period, from 22 September 2016 to 12 October 2020, the ground probably cooled irreversibly by 1.5 °C. In order to illustrate and evaluate the speed of changes in the ground, the one’s profile with an undisturbed temperature field was presented for each month of the year. The presented results can be a very important source of information for the analysis of geothermal conditions occurring in the ground. They can be used to verify mathematical models and conduct long-term simulations that allow us to see the complexity of the processes taking place in the ground.

Comparison between experimental results of different technologies for arsenic removal from water intended for human consumption

2019 ◽  
Vol 14 (4) ◽  
pp. 884-896
Author(s):  
Maria Cristina Collivignarelli ◽  
Silvestro Damiani ◽  
Sabrina Sorlini
Keyword(s):  
Drinking Water ◽  
Arsenic Removal ◽  
Experimental Studies ◽  
Treatment Plant ◽  
Arsenic Contamination ◽  
Full Scale ◽  
Laboratory Scale ◽  
Basic Solution ◽  
First Case

Abstract Arsenic contamination in drinking water is a major issue in the present world. Techniques such as oxidation, precipitation and adsorption have been widely used for arsenic removal. The goal of this work is to analyze four case studies where the problem of arsenic contamination in groundwater is faced with an approach that includes experimental activities at laboratory scale and/or pilot scale. The first case study investigates the mechanisms for enhancing arsenic removal with naturally occurring Fe by the addition of an oxidizing agent (KMnO4) or a concentrated basic solution of MnO4− and AlO2−. In the second case study, different experimental tests are carried out at laboratory scale in order to identify the best combination of treatments to be applied at full scale. The third case study shows the results of experimental studies followed by a full-scale upgrading for a drinking water treatment plant (DWTP) with no specific arsenic treatment in the first configuration. Last, the fourth case study investigates the performance of granular ferric oxide (GFO) with arsenic concentrations close to the Italian regulatory limit. A pilot GFO filter was installed in a DWTP. The monitoring results led to the implementation of the GFO filter at full scale.

A Methodology for Characterizing System-Level ESD Sensitivity

2004 ◽  
Author(s):  
Marie-Pascale Chagny ◽  
John A. Naoum
Keyword(s):  
Electrostatic Discharge ◽  
Computer Systems ◽  
Electronic Equipment ◽  
Experimental Methodology ◽  
Computer Users ◽  
System Level ◽  
Permanent Damage ◽  
Design Improvement ◽  
Desktop Computers

Abstract Over the years, failures induced by an electrostatic discharge (ESD) have become a major concern for semiconductor manufacturers and electronic equipment makers. The ESD events that cause destructive failures have been studied extensively [1, 2]. However, not all ESD events cause permanent damage. Some events lead to recoverable failures that disrupt system functionality only temporarily (e.g. reboot, lockup, and loss of data). These recoverable failures are not as well understood as the ones causing permanent damage and tend to be ignored in the ESD literature [3, 4]. This paper analyzes and characterizes how these recoverable failures affect computer systems. An experimental methodology is developed to characterize the sensitivity of motherboards to ESD by simulating the systemlevel ESD events induced by computer users. The manuscript presents a case study where this methodology was used to evaluate the robustness of desktop computers to ESD. The method helped isolate several weak nets contributing to the failures and identified a design improvement. The result was that the robustness of the systems improved by a factor of 2.

Scales and Units

2018 ◽  
Author(s):  
Kathryn M. de Luna
Keyword(s):  
Language Change ◽  
Historical Linguistics ◽  
Bantu Languages ◽  
The North ◽  
First Case ◽  
Linguistic Evidence ◽  
River Region ◽  
History Of ◽  
Alternative Approaches

This chapter uses two case studies to explore how historians study language movement and change through comparative historical linguistics. The first case study stands as a short chapter in the larger history of the expansion of Bantu languages across eastern, central, and southern Africa. It focuses on the expansion of proto-Kafue, ca. 950–1250, from a linguistic homeland in the middle Kafue River region to lands beyond the Lukanga swamps to the north and the Zambezi River to the south. This expansion was made possible by a dramatic reconfiguration of ties of kinship. The second case study explores linguistic evidence for ridicule along the Lozi-Botatwe frontier in the mid- to late 19th century. Significantly, the units and scales of language movement and change in precolonial periods rendered visible through comparative historical linguistics bring to our attention alternative approaches to language change and movement in contemporary Africa.

Applications of random graphs

2017 ◽  
Author(s):  
A.C.C. Coolen ◽  
A. Annibale ◽  
E.S. Roberts
Keyword(s):  
Social Networks ◽  
Random Graphs ◽  
Interaction Network ◽  
Power Grids ◽  
Protein Protein Interaction ◽  
Topological Features ◽  
First Case ◽  
The Stability ◽  
Protein Protein Interaction Network

This chapter reviews graph generation techniques in the context of applications. The first case study is power grids, where proposed strategies to prevent blackouts have been tested on tailored random graphs. The second case study is in social networks. Applications of random graphs to social networks are extremely wide ranging – the particular aspect looked at here is modelling the spread of disease on a social network – and how a particular construction based on projecting from a bipartite graph successfully captures some of the clustering observed in real social networks. The third case study is on null models of food webs, discussing the specific constraints relevant to this application, and the topological features which may contribute to the stability of an ecosystem. The final case study is taken from molecular biology, discussing the importance of unbiased graph sampling when considering if motifs are over-represented in a protein–protein interaction network.

scholarly journals Food Bioactive Compounds and Emerging Techniques for Their Extraction: Polyphenols as a Case Study

Foods ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 37 ◽  
Author(s):  
José S. Câmara ◽  
Bianca R. Albuquerque ◽  
Joselin Aguiar ◽  
Rúbia C. G. Corrêa ◽  
João L. Gonçalves ◽  
...  
Keyword(s):  
Bioactive Compounds ◽  
Chemical Structure ◽  
Experimental Studies ◽  
Analytical Techniques ◽  
Convincing Evidence ◽  
Protective Effects ◽  
Extraction Techniques ◽  
Biological Impact ◽  
Preventive Effects

Experimental studies have provided convincing evidence that food bioactive compounds (FBCs) have a positive biological impact on human health, exerting protective effects against non-communicable diseases (NCD) including cancer and cardiovascular (CVDs), metabolic, and neurodegenerative disorders (NDDs). These benefits have been associated with the presence of secondary metabolites, namely polyphenols, glucosinolates, carotenoids, terpenoids, alkaloids, saponins, vitamins, and fibres, among others, derived from their antioxidant, antiatherogenic, anti-inflammatory, antimicrobial, antithrombotic, cardioprotective, and vasodilator properties. Polyphenols as one of the most abundant classes of bioactive compounds present in plant-based foods emerge as a promising approach for the development of efficacious preventive agents against NCDs with reduced side effects. The aim of this review is to present comprehensive and deep insights into the potential of polyphenols, from their chemical structure classification and biosynthesis to preventive effects on NCDs, namely cancer, CVDs, and NDDS. The challenge of polyphenols bioavailability and bioaccessibility will be explored in addition to useful industrial and environmental applications. Advanced and emerging extraction techniques will be highlighted and the high-resolution analytical techniques used for FBCs characterization, identification, and quantification will be considered.

Investigating the potential of redundant manipulators in narrow channels

2020 ◽  
pp. 095440622096451
Author(s):  
Ashish Singla ◽  
Jyotindra Narayan ◽  
Himanshu Arora
Keyword(s):  
Case Studies ◽  
Fuzzy Inference ◽  
Redundant Manipulators ◽  
Redundancy Resolution ◽  
Inference System ◽  
Narrow Channels ◽  
First Case ◽  
Task Priority ◽  
Patient Side

In this paper, an attempt has been made to investigate the potential of redundant manipulators, while tracking trajectories in narrow channels. The behavior of redundant manipulators is important in many challenging applications like under-water welding in narrow tanks, checking the blockage in sewerage pipes, performing a laparoscopy operation etc. To demonstrate this snake-like behavior, redundancy resolution scheme is utilized using two different approaches. The first approach is based on the concept of task priority, where a given task is split and prioritize into several subtasks like singularity avoidance, obstacle avoidance, torque minimization, and position preference over orientation etc. The second approach is based on Adaptive Neuro Fuzzy Inference System (ANFIS), where the training is provided through given datasets and the results are back-propagated using augmentation of neural networks with fuzzy logics. Three case studies are considered in this work to demonstrate the redundancy resolution of serial manipulators. The first case study of 3-link manipulator is attempted with both the approaches, where the objective is to track the desired trajectory while avoiding multiple obstacles. The second case study of 7-link manipulator, tracking trajectory in a narrow channel, is investigated using the concept of task priority. The realistic application of minimum-invasive surgery (MIS) based trajectory tracking is considered as the third case study, which is attempted using ANFIS approach. The 5-link spatial redundant manipulator, also known as a patient-side manipulator being developed at CSIR-CSIO, Chandigarh is used to track the desired surgical cuts. Through the three case studies, it is well demonstrated that both the approaches are giving satisfactory results.

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