• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 16
  • 4
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 38
  • 13
  • 11
  • 10
  • 10
  • 5
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Hållbar energi till mobila hem vintertid : Ett koncept för hållbar energiutvinning, utvald med analytisk metodik / Sustainable energy for recreational vehicles during winter season : A product development process with an analytical concept selection

Deljerud, Hampus January 2021 (has links)
Detta projekt har utförts som examinerande moment i kursen: examensarbete för högskoleingenjörsexamen i innovationsteknik och design, MSGC12, 22,5 hp. Projektet inleddes och utfördes av Hampus Deljerud med hjälp av Invencon AB. Handledare på universitetet var Monica Jakobsson, och examinator i kursen var professor Leo de Vin. Ett problem har identifierats att ägare av fritidsfordon har svårt att tillgodose sitt behov av hushållsel under vintern. Under projektet har en rad marknadsundersökningar genomförts där behovet och existerande lösningar har undersökts. Enkäter och andra undersökningsmetoder resulterade i att över hundra respondenter tog sin tid och visade intresse för att svara på frågor och delta i omröstningar. När problemet hade fastställts gjordes en projektplan för att klargöra mål, avgränsningar, milstolpar och deadlines. Detta kompletterades även med riskanalyser i försök att eliminera eventuella fallgropar.  Utifrån litteraturstudier och marknadsundersökningar sammanställdes alla krav i en kravspecifikation. Kravspecifikationen användes för att se till att alla nya koncept uppfyllde alla krav. Idégenereringar utfördes digitalt med hjälp av tre olika grupper över videosamtal. Alla deltagare fick möjlighet att dela sina tankar och idéer direkt över nätet via Google drive. Tjugoen koncept togs fram och sållades ned till fem potentiella lösningar som tillgodosåg de krav som ställdes i kravspecifikationen.   Ett Exceldokument togs fram där väderdata från SMHI användes i en beräkningskalkyl för att hitta den bästa lösningen på grundproblemet. Den bästa lösningen visade sig vara en kombination av energisystem där en del av systemet består av ett hopfällbart vindkraftverk. Vindkraftverkets fällmekanism tar hjälp av generatorn i kraftverket och vajrar. Genom tillämpning av existerande mekanik i dagens vindkraftverk görs konstruktionen med färre delar och resulterar i en lösning som bedöms vara gynnsam ur ett ekonomiskt perspektiv.
22

<b>Measurements for TEG based Energy Harvesting for </b><b>EQS-HBC Body Nodes and </b><b>EM Emanations for Hardware Security</b>

Yi Xie (17683731) 20 December 2023 (has links)
<p dir="ltr">Sensing and communication circuits and systems are crucial components in various electronic devices and technologies. These systems are designed to acquire information from the surrounding environment through sensors, process that information, and facilitate communication between different devices or systems. It plays a vital role in modern electronic devices, enabling them to collect, process, and exchange information to perform various functions in applications such as IoB (Internet of Body), healthcare, hardware security, industrial automation, and more.</p><p dir="ltr">This work focuses on innovations in sensing and communication circuits spanning two independent application areas – human body communication and hardware emanations security.</p><p dir="ltr">First, an ultra-low power ECG monitoring system is implemented to perpetually power itself using Thermoelectric Generator (TEG) to harvest body energy while securely transmitting sensed data through on-body communication, achieving closed-loop operation without external charging or batteries. Custom circuits allow demonstrated feasibility of self-sustaining wearables leveraging Human Body Communication’s advantages.</p><p dir="ltr">Second, investigations reveal vulnerabilities introduced when repairing broken cables, with unintended monopole antennas boosting electromagnetic emissions containing signal correlations. Experiments characterize long-range detection regimes post-repair across USB keyboard cables. Further circuit and structural innovations provide localized shielding at repair points as a potential mitigation. Advancements offer contributions in understanding hardware emission security risks to inform protection strategies.</p><p dir="ltr">The two separate research work demonstrate specialized circuits advancing the state-of-the-art in sensing and communication for wearable body-based systems and hardware security through greater awareness of vulnerabilities from unintended emissions.</p><p><br></p>
23

Effect of whole blood viscosity and red cell mass on canine thromboelastographic tracings

Brooks, Aimee C. 28 August 2014 (has links)
No description available.
24

Thromboelastographic Clot Parameters of Autologous Equine Blood Products Activated by Various Clotting Agents

Ghassab, Sasan 28 August 2014 (has links)
No description available.
25

Exhaust system energy management of internal combustion engines

Wijewardane, M. Anusha January 2012 (has links)
Today, the investigation of fuel economy improvements in internal combustion engines (ICEs) has become the most significant research interest among the automobile manufacturers and researchers. The scarcity of natural resources, progressively increasing oil prices, carbon dioxide taxation and stringent emission regulations all make fuel economy research relevant and compelling. The enhancement of engine performance solely using incylinder techniques is proving increasingly difficult and as a consequence the concept of exhaust energy recovery has emerged as an area of considerable interest. Three main energy recovery systems have been identified that are at various stages of investigation. Vapour power bottoming cycles and turbo-compounding devices have already been applied in commercially available marine engines and automobiles. Although the fuel economy benefits are substantial, system design implications have limited their adaptation due to the additional components and the complexity of the resulting system. In this context, thermo-electric (TE) generation systems, though still in their infancy for vehicle applications have been identified as attractive, promising and solid state candidates of low complexity. The performance of these devices is limited to the relative infancy of materials investigations and module architectures. There is great potential to be explored. The initial modelling work reported in this study shows that with current materials and construction technology, thermo-electric devices could be produced to displace the alternator of the light duty vehicles, providing the fuel economy benefits of 3.9%-4.7% for passenger cars and 7.4% for passenger buses. More efficient thermo-electric materials could increase the fuel economy significantly resulting in a substantially improved business case. The dynamic behaviour of the thermo-electric generator (TEG) applied in both, main exhaust gas stream and exhaust gas recirculation (EGR) path of light duty and heavy duty engines were studied through a series of experimental and modelling programs. The analyses of the thermo-electric generation systems have highlighted the need for advanced heat exchanger design as well as the improved materials to enhance the performance of these systems. These research requirements led to the need for a systems evaluation technique typified by hardware-in-the-loop (HIL) testing method to evaluate heat exchange and materials options. HIL methods have been used during this study to estimate both the output power and the exhaust back pressure created by the device. The work has established the feasibility of a new approach to heat exchange devices for thermo-electric systems. Based on design projections and the predicted performance of new materials, the potential to match the performance of established heat recovery methods has been demonstrated.
26

An Exploration of the Properties of Repair Template DNA that Promote Precision Genome Editing

Ghanta, Krishna S. 03 August 2021 (has links)
CRISPR/Cas9 induced DNA breaks can be precisely repaired by cellular homology-directed repair (HDR) pathways using exogenously provided template DNA (donor). However, the full potential of precision editing is hindered in many model systems by low cutting efficiencies, low HDR efficiencies and, cytotoxicity related to Cas9 and donor DNA. In this thesis, I address these challenges and present methods that we developed to increase HDR efficiencies in multiple model organisms. In Caenorhabditis elegans, we show that by reducing toxicity high editing efficiencies can be achieved with single stranded oligonucleotide (ssODN) donors. We demonstrate that melting dsDNA donors dramatically improves the knock-in efficiencies of longer (1kb) edits. In addition, we describe 5′-terminal modifications to the donor molecules that further increase the frequency of precision editing. With our methodology a single optimally injected animal can yield more than 100 Green Fluorescent Protein (GFP) positive progeny, dramatically enhancing efficiency of genome editing. Next, we demonstrate the generality of 5′ modified donors by extending our studies to human cell cultures and mice zygotes. In mammalian models, 2′OMe-RNA modifications consistently increase HDR efficiencies by several fold over unmodified donors. Furthermore, end-modified donors exhibited a striking reduction in end-joining reactions including reduced concatemer formation and reduced direct ligation into the host genome. Our study demonstrates that HDR can be improved without inhibiting competing end-joining pathways and provides a platform to identify new chemical modifications that could further increase the potency and efficacy of precision genome editing.
27

Využití termoelektrického generátoru pro zvýšení účinnosti otopného tělesa / Using thermoelectric generator to increase the efficiency of the radiator

Kříž, Pavel January 2015 (has links)
This diploma thesis deals with a design layout of the fan power supply that ensures the increase of the efficiency of the heating unit. For usage in the areas without electric power, the power supply is secured by thermoelectric generator. The system has to function on the basis of autonomous system which turns itself on only when necessary. In the introductory part of the paper there is a recherché of thermoelectric generators for general usage. Next it mentions the basic findings in from the field of DC/DC converters for low power applications. In this part attention is given to MPPT algorithm. Furthermore basic knowledge from the field of heat transmission together with its most used elements is described. Subsequently existing applications that increase the effectiveness of heating are mentioned. Their disadvantage however is that they depend on the external source of power supply. The practical part to a large extent covers the analysis of the suitability of the chosen thermoelectric module. For securing of the heat gradient of the generator there was a model created meeting the figures in the manual and there are several simulations in the MATLAB program. Furthermore several measurements of the thermoelectric module took place in order to secure realistic figures. Subsequently a DC/DC converter was chosen. Finally the testing was made on the real composition. In conclusion there is an overall evaluation including the real usage and the economical aspect of the project. The outcomes of the work enable to avoid common mistakes that are part of many specialized articles. The created system is to be used after the adjustment of the cooling to the required aim. At the same time it becomes very effective.
28

MEMS termoelektrický generátor v letecké aplikaci / MEMS Thermoelectric Generator for Aerospace Applications

Janák, Luděk January 2014 (has links)
Tato diplomová práce se zabývá vývojem autonomního zdroje elektrické energie založeného na MEMS termoelektrickém generátoru. Uvažovaný generátor bude následně použit pro napájení autonomní senzorické jednotky pro letecké aplikace. Systémový pohled na autonomní senzorickou jednotku zahrnuje senzor se zpracováním a přenosem dat, energy harvester (termoelektrický generátor), power management, akumulační prvek a autodiagnostiku. Všechny výše uvedené komponenty jsou v práci podrobně popsány. V úvodu práce je provedena široká rešerše existujících termoelektrických generátorů pro letecké aplikace. Následně jsou popsány základní teoretické poznatky z oblasti DC/DC měničů pro energy harvesting. Zvláštní pozornost je věnována metodám MPPT (Maximum Power Point Tracking). Jako základ pro vývoj napájení autonomní senzorické jednotky bylo provedeno množství simulací za pomoci nástroje MATLAB/Simulink Simscape. Pro identifikaci prametrů modelu posloužilo měření na speciálním přípravku. Praktická implementace teoreticky popsaných problémů je provedena na k tomuto účelu navrženém technologickém demonstrátoru. Závěrem je zhodnocena reálná využitelnost navržené technologie pro finální aplikaci v leteckém průmyslu.
29

Mechatronic Design and Verification of Autonomic Thermoelectric Energy Source for Aircraft Application / Mechatronic Design and Verification of Autonomic Thermoelectric Energy Source for Aircraft Application

Ančík, Zdeněk January 2016 (has links)
Předložená disertační práce řeší komplexní mechatronický návrh autonomního termoelektrického zdroje energie pro letecké aplikace. Na základě dostupných zdrojů a literatury práce popisuje současný stav problematiky. V práci jsou prezentovány simulační modely MEMS termoelektrických článků, které jsou ověřeny experimentálním testováním a hodnotami dostupnými od výrobce. Na základě metodiky model-besed design byly navrženy a vyrobeny tři demonstrátory. Jejich vlastnosti byly testovány v reálných podmínkách na letecké pohonné jednotce.
30

The Development of a DC Micro-grid model with Maximum Power Point Tracking for Waste Heat Recovery Systems

Elrakaybi, Ahmed 06 1900 (has links)
Research in sustainable energy sources has become the interest of many studies due to the increasing energy demand and the amount of wasted energy released from existing methods, along with their effect on climate change and environment sustainability. Thermo-Electric Generators (TEGs) are a potential solution that is being studied and implemented as they can convert low grade thermal energy to useful electrical energy at various operating conditions. The integration of a TEG within a heat exchanger (TEG/HX) system connected to an electrical DC micro-grid, using a Maximum Power Point Tracking (MPPT) system is the focus of this study. Using a numerical TEG/HX model from a previous study and a developed DC micro-grid model the interaction between the thermal and electrical aspects were investigated with the focus on the electrical performance of the system. The main concern of this study is to investigate the effect of the sub components of the DC micro-grid on the overall available energy. An analytic model was developed to estimate the power loss in the electrical circuit of the micro-grid, the model utilizes the equations for switching and conduction losses which have been used by several studies. Other variables such as the battery characteristics and electrical load profiles were also investigated by simulating several case studies including changing operating conditions. This study shows the effect of a TEG configuration on the power loss in an electrical system using power loss curves in comparison with the Open Circuit Voltage (OCV) of such configuration. It also covers important modes of operation for the battery, loads and MPPT for a stable and reliable operation of an isolated DC micro-grid system were TEGs are the only source of power. The result of the study presented is a system design that is able to maximize the electrical energy harvested from the TEGs to extend the operation of the dc-micro-grid first by applying a suitable TEG configuration and consequently a suitable electrical circuit. Secondly, by adapting to the changing operating conditions of the TEGs and the loads; and compensating for these changes using the battery storage system. / Thesis / Master of Applied Science (MASc)

Page generated in 0.0147 seconds