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  • 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.
91

Síntese e cicatrização de pele em cães com fio de náilon, fio farpado e grampo cirúrgico / Synthesis and skin healing in dogs with nailon wire, barbed wire and surgical clip

Santos, Eduardo Rosa dos January 2018 (has links)
A dermorrafia é vital para o sucesso do procedimento por ser a última etapa cirúrgica. Este estudo comparou a síntese e o processo de cicatrização de pele em cães com a utilização de três diferentes materiais, fio de náilon (grupo GFN), fio farpado (grupo GFF) e grampo cirúrgico (grupo GGC), após ovariohisterectomia. Foram utilizadas 27 fêmeas caninas aptas a serem castradas eletivamente que não apresentavam comorbidades. Os animais foram divididos randomicamente nos três grupos e submetidos à dermorrafia com os materiais a serem testados. Foram avaliados: o tempo para a sutura da pele, as complicações relatadas pelos tutores e a temperatura local da pele em cicatrização. Foram também avaliados diversos parâmetros clínicos de cicatrização em sete dias de pósoperatório, bem como parâmetros histológicos de biópsias de pele coletadas aos 14 dias. O grampo cirúrgico apresentou o menor tempo (p<0,001) para dermorrafia e a maior ocorrência de deiscências de sutura. O fio farpado apresentou o menor escore (p=0,006) de alterações clínicas aos sete dias de pós-cirúrgico e não apresentou ocorrência de deiscência de sutura. Contudo não houve diferença entre os grupos quanto à avaliação histológica da biópsia cicatricial aos 14 dias. O fio farpado apresentou segurança na sutura e fácil manipulação na dermorrafia de cães, enquanto o grampo cirúrgico utilizado mostrou-se pouco confiável devido ao grau elevado de deiscência. / Dermorrhaphy is vital to the success of the procedure because it is the last surgical step. This study compared the synthesis and the process of skin healing in dogs using three different materials, nylon thread (GFN group), barbed wire (GFF group) and surgical staple [SV1] (GGC group) after ovariohysterectomy. Twenty-seven canine females without comorbidities were electively castrated. The animals were randomly divided into three treatment groups and submitted to dermorrhaphy with the materials to be tested.. The following were evaluated: time to suture the skin with each material, the complications reported by the tutors and the local temperature of the skin in healing process. Several clinical parameters of healing were also evaluated in seven postoperative days, as well as histological parameters of skin biopsies collected at 14 days. The surgical staple showed the shortest time (p<0.001) for dermorrhaphy and the higher occurrence of suture dehiscences. The barbed wire had the lowest score (p=0.006) of clinical changes on the seventh postoperative day and did not presented an occurrence of suture dehiscence. However, there was no difference between the groups regarding the histological evaluation of cicatricial biopsy at 14 days. The barbed wire showed security in the suture and easy manipulation in the dermorrhaphy of dogs, while the surgical staple used proved to be unreliable due to the high degree of dehiscence.
92

Unstructured Computations on Emerging Architectures

Al Farhan, Mohammed 05 May 2019 (has links)
This dissertation describes detailed performance engineering and optimization of an unstructured computational aerodynamics software system with irregular memory accesses on various multi- and many-core emerging high performance computing scalable architectures, which are expected to be the building blocks of energy-austere exascale systems, and on which algorithmic- and architecture-oriented optimizations are essential for achieving worthy performance. We investigate several state-of-the-practice shared-memory optimization techniques applied to key kernels for the important problem class of unstructured meshes. We illustrate for a broad spectrum of emerging microprocessor architectures as representatives of the compute units in contemporary leading supercomputers, identifying and addressing performance challenges without compromising the floating-point numerics of the original code. While the linear algebraic kernels are bottlenecked by memory bandwidth for even modest numbers of hardware cores sharing a common address space, the edge-based loop kernels, which arise in the control volume discretization of the conservation law residuals and in the formation of the preconditioner for the Jacobian by finite-differencing the conservation law residuals, are compute-intensive and effectively exploit contemporary multi- and many-core processing hardware. We therefore employ low- and high-level algorithmic- and architecture-specific code optimizations and tuning in light of thread- and data-level parallelism, with a focus on strong thread scaling at the node-level. Our approaches are based upon novel multi-level hierarchical workload distribution mechanisms of data across different compute units (from the address space down to the registers) within every hardware core. We analyze the demonstrated aerodynamics application on specific computing architectures to develop certain performance metrics and models to bespeak the upper and lower bounds of the performance. We present significant full application speedup relative to the baseline code, on a succession of many-core processor architectures, i.e., Intel Xeon Phi Knights Corner (5.0x) and Knights Landing (2.9x). In addition, the performance of Knights Landing outperforms, at significantly lower power consumption, Intel Xeon Skylake with nearly twofold speedup. These optimizations are expected to be of value for many other unstructured mesh partial differential equation-based scientific applications as multi- and many- core architecture evolves.
93

Výroby závitů závitníky / Production of threads with taps

Nasyrov, Ildar January 2017 (has links)
In the theoretical part of this thesis are described types of threads, methods of production and control of threads, types of taps, types of coatings and cutting fluids, analysis of specific cutting forces during thread cutting and theoretical analysis of the cross-section distribution by taps using. The experimental part of this thesis includes the production of internal threads by cutting tap at constant cutting conditions. The cutting time was measured according to the function of time during the experiment. The measured data were statistically processed and, as a result, the cost of one thread production was calculated.
94

Účel designu u ručního nářadí / The purpose of design for hand tools

Remeš, David January 2018 (has links)
This thesis deals with the effect of the design on hand tools. In the first theoretical part of this thesis, individual manual operations carried out during manufacturing are being further analyzed. The next part then focuses on the individual aspects of the product design and its influence on the hand tools. Followed by the processing of achieved parameters in handwork. The experimental part of this thesis deals with adjustments of the tap wrench´s handles made for manual cutting of internal threads. The utilization of the material when selecting a semi-finished product from blanks as well as the evaluation of the manufacturing in this way itself are also closely described in this part.
95

Zvyšování řezivosti maticových závitníků pomocí PVD povlaků / On the increase of cutting performance of thread cutting taps with PVD coatings

Samešová, Zina January 2012 (has links)
This thesis, in its theoretical part deals with the process of cutting, abrasion-resistant layers properties and their contribution to increasing of cutting properties. The second part of the thesis is experimental. It aims to determine, compare and subsequently evaluate cutting properties of threading tools using matrix taps with different types of PVD coatings. During implementation of the experiment, constant cutting conditions have been ensured and the only variable was the different types of coating layers. Outcome of the experiment is measurement of cutting torques in relation on time and rate of wear of cutting tools.
96

Biomechanická studie profilu závitu zubních implantátů. / Biomechanics study profile thread of dental surgical implant

Konečný, Michal January 2011 (has links)
This thesis deals with mechanical interaction between spiral implant and bone tissue. Also it deals with study which is concerned with threat profiles of certain dental implants. At the beginning of the first part is listed brief history of dental implants with emphasis on the technical progress in this area. Knowledge of orofacial system anatomy (informations about orofacial system anatomy) and more detailed structural analysis focused on implantology are included into another chaps of the first part. The second part of the paper analyses certain types of thread profile. Some of the computed models of dental implant types are solved through the use of the finite element method. After strain-stress analyse differences between mechanical qualities of single thread profiles are evaluated and compared.
97

DirectX 12: Performance Comparison Between Single- and Multithreaded Rendering when Culling Multiple Lights

J'lali, Yousra January 2020 (has links)
Background. As newer computers are constructed, more advanced and powerful hardware come along with them. This leads to the enhancement of various program attributes and features by corporations to get ahold of the hardware, hence, improving performance. A relatively new API which serves to facilitate such logic, is Microsoft DirectX 12. There are numerous opinions about this specific API, and to get a slightly better understanding of its capabilities with hardware utilization, this research puts it under some tests. Objectives. This article’s aim is to steadily perform tests and comparisons in order to find out which method has better performance when using DirectX 12; single-threading, or multithreading. For performance measurements, the average CPU and GPU utilizations are gathered, as well as the average FPS and the speed of which it takes to perform the Render function. When all results have been collected, the comparison between the methods are assessed. Methods. In this research, the main method which is being used is experiments. To find out the performance differences between the two methods, they must undergo different trials while data is gathered. There are four experiments for the single-threaded and multithreaded application, respectively. Each test varies in the number of lights and objects that are rendered in the simulation environment, gradually escalading from 50; then 100; 1000; and lastly, 5000. Results. A similar pattern was discovered throughout the experiments, with all of the four tests, where the multithreaded application used considerably more of the CPU than the single-threaded version. And despite there being less simultaneous work done by the GPU in the one-threaded program, it appeared to be using more GPU utilization than multithreading. Furthermore, the system with many threads tended to perform the Render function faster than its counterpart, regardless of which test was executed. Nevertheless, both applications never differed in FPS. Conclusion. Half of the hypotheses stated in this article were contradicted after some unexpected tun of events. It was believed that the multithreaded system would utilize less of the CPU and more of the GPU. Instead, the outcome contradicted the hypotheses, thus, opposing them. Another theory believed that the system with multiple threads would execute the Render function faster than the other version, a hypothesis that was strongly supported by the results. In addition to that, more objects and lights inserted into the scene did increased the applications’ utilization in both the CPU and GPU, which also supported another hypothesis. In conclusion, the multithreaded program performs faster but still has no gain in FPS compared to single-threading. The multithreaded version also utilizes more CPU and less GPU
98

The Effect of Fe-sulfate on Annual Bluegrass, Silvery Thread Moss, and Dollar Spot Populations Colonizing Creeping Bentgrass Putting Greens

Reams, Nathaniel Frederick 05 June 2013 (has links)
Annual bluegrass (Poa annua L.) is the most problematic weed to control in creeping bentgrass (Agrostis stolonifera L.) putting greens.  The objective of this study was to transition a mixed putting green stand of annual bluegrass and creeping bentgrass to a monoculture by using fertilizers and plant growth regulators that selectively inhibit annual bluegrass.  A 25 year old loamy sand rootzone research green, planted with \'Penn-Eagle\' creeping bentgrass, with roughly 45% initial annual bluegrass coverage was utilized.  The biweekly application of ammonium sulfate (4.8 kg ha-1) with treatments of ferrous sulfate at rates of 0, 12.2, 24.4, and 48.8 kg ha-1 and in combination with seaweed extract (12.8 L ha-1) or paclobutrazol (0.37 L ai ha-1 spring and fall; 0.18 L ai ha-1 summer) were applied March to October, 2011 and 2012.  Plots receiving the highest rate of ferrous sulfate resulted in annual bluegrass infestation declines from an early trial amount of 45% to a final average of 20% but also resulted in unacceptable late-summer events of annual bluegrass collapse.  The ferrous sulfate medium rate resulted in a smooth transition from early-trial annual bluegrass infestation of 45% to an end of trial infestation of 20% and had the highest putting green quality.  Previous research has reported that consistent use of paclobutrazol can effectively and safely reduce annual bluegrass infestations.  In this trial annual bluegrass was reduced to 9% infestation after three months of application.  Two unexpected observations from this trial were that ferrous sulfate, applied at medium to high rates, significantly reduced silvery thread moss (Bryum argentum Hedw.) populations and occurrences of dollar spot (Sclerotinia homoeocarpa F. T. Bennett) disease.  Dollar spot control with ferrous sulfate has not previously been reported in the literature, so additional studies were designed to investigate this phenomenon further.  A creeping bentgrass putting green study was conducted to determine if sulfur, iron, or the two combined as ferrous sulfate decreases dollar spot activity.  Ferrous sulfate resulted in the highest turf quality and suppressed S. homoeocarpa infection, even during high disease pressure.  Fe-EDTA suppressed dollar spot infection as well as ferrous sulfate but quality declined to unacceptable levels during the summer, due to Fe-EDTA only.  Sulfur did not affect or increased S. homoeocarpa infection, indicating that a high and frequent foliar rate of iron is responsible for dollar spot control.  An in-vitro study was conducted to determine if agar pH in combination with iron concentrations affects mycelial growth of S. homoeocarpa.  Results from this trial indicated that 5.4 agar pH is an optimal pH for mycelial growth.  The 10 to 100 mg iron kg-1 concentration had little effect on mycelial growth at 5.0 and 5.5 pH, but increased growth at 4.5 and 6.5 pH.  As the iron concentration was increased from 10 to 100 to 1000 mg kg-1, mycelial growth decreased or stopped.  Our final conclusions are that seasonal biweekly foliar applications of the medium rate of ferrous sulfate (24.4 kg ha-1) safely and effectively reduced annual bluegrass infestation out of a creeping bentgrass putting green, while also effectively suppressing silvery thread moss and dollar spot incidence. / Master of Science
99

A framework for finding and summarizing product defects, and ranking helpful threads from online customer forums through machine learning

Jiao, Jian 05 June 2013 (has links)
The Internet has revolutionized the way users share and acquire knowledge. As important and popular Web-based applications, online discussion forums provide interactive platforms for users to exchange information and report problems. With the rapid growth of social networks and an ever increasing number of Internet users, online forums have accumulated a huge amount of valuable user-generated data and have accordingly become a major information source for business intelligence. This study focuses specifically on product defects, which are one of the central concerns of manufacturing companies and service providers, and proposes a machine learning method to automatically detect product defects in the context of online forums. To complement the detection of product defects , we also present a product feature extraction method to summarize defect threads and a thread ranking method to search for troubleshooting solutions. To this end, we collected different data sets to test these methods experimentally and the results of the tests show that our methods are very promising: in fact, in most cases, they outperformed the current state-of-the-art methods. / Ph. D.
100

Integration of UAVS with Real Time Operating Systems and Establishing a Secure Data Transmission

Ravi, Niranjan 08 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / In today’s world, the applications of Unmanned Aerial Vehicle (UAV) systems are leaping by extending their scope from military applications on to commercial and medical sectors as well. Owing to this commercialization, the need to append external hardware with UAV systems becomes inevitable. This external hardware could aid in enabling wireless data transfer between the UAV system and remote Wireless Sensor Networks (WSN) using low powered architecture like Thread, BLE (Bluetooth Low Energy). The data is being transmitted from the flight controller to the ground control station using a MAVlink (Micro Air Vehicle Link) protocol. But this radio transmission method is not secure, which may lead to data leakage problems. The ideal aim of this research is to address the issues of integrating different hardware with the flight controller of the UAV system using a light-weight protocol called UAVCAN (Unmanned Aerial Vehicle Controller Area Network). This would result in reduced wiring and would harness the problem of integrating multiple systems to UAV. At the same time, data security is addressed by deploying an encryption chip into the UAV system to encrypt the data transfer using ECC (Elliptic curve cryptography) and transmitting it to cloud platforms instead of radio transmission.

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