1,037 research outputs found
Optimizing the load carrying performance of the hydraulic guiding elements with finite elements method
xvi, 55 pages29 cm. 1 CDÖZETHidrolik ve pnömatik sistemlerin uzun süreli sorunsuz çalışmasında önemli bir etkiye sahip olan kılavuz elemanlar, hidrolik ve pnömatik silindirlerde eksene dik olan kuvvetlere direnerek metal-metal temasını önlemek için kullanılır. Kılavuz elemanlarda en sık kullanılan malzemelerden biri olan kompozit malzemelerde, fiber yönelimleri ve takviye malzeme oranları gibi farklı parametreler, ürünün kalitesini ve mukavemetini büyük ölçüde etkiler. Bu çalışmada, kompozit kılavuz elemanların sonlu elemanlar yöntemi kullanılarak malzemeden ürüne geçiş aşamalarının ve Digimat, Moldex3D ve MSC Marc programları kullanılarak simülasyon çalışmaları yapılması amaçlanmıştır. Analiz çalışmaları, kompozit malzeme modellemesinde kullanılan Digimat, plastik enjeksiyon üretiminin simülasyonunda kullanılan Moldex3D ve nihai ürün için doğrusal olmayan analizde kullanılan MSC Marc ile entegre bir şekilde gerçekleştirilmiştir. Yapılan analiz sonucunda ürünün boşluktaki dolum durumu, çekme değeri ve basınç değeri Moldex3D programında görüntülendi. Moldex3D programından dışa aktarılan elyaf oryantasyonları Digimat programında işlendi ve oluşturulan malzeme modeli. Daha sonra hazırlanan malzeme modeli Marc programına aktarılmış, doğrusal olmayan analizler yapılmış ve sonuçlar karşılaştırmalı olarak incelenmiştir. Bu simülasyonların doğrulaması, Kastaş Sızdırmazlık Teknolojileri Test Merkezi'nde yapılan testler ile sağlanmaktadır. Optimizasyon çalışmaları sonucunda kompozit hidrolik taşıyıcı elemanın yük taşıma kabiliyeti artırılmıştır.ABSTRACTGuiding elements, which have an important effect on the long-term trouble-free operation of hydraulic and pneumatic systems, resist the forces perpendicular to the axis in hydraulic and pneumatic cylinders and are used to prevent metal-to-metal contact. In composite materials, which is one of the most frequently used materials in guiding elements, different parameters such as fiber orientations and reinforcement material ratios greatly affect the quality and strength of the product. In this study, it is aimed to analyze the transition steps of composite guiding elements from material to the product by using the finite element method and simulation studies using Digimat, Moldex3D, and MSC Marc programs. The analysis studies were carried out in an integrated manner with Digimat used in composite material modeling, Moldex3D used in simulating plastic injection production, and MSC Marc used in the nonlinear analysis for the final product. As a result of the analysis, the filling status, shrinkage value, and pressure value of the product in the cavity were displayed in the Moldex3D program. The fiber orientations exported from the Moldex3D program were processed in the Digimat program and the material model generated. Then, the prepared material model transferred to the Marc program, nonlinear analysis made, and the results examined comparatively. Validation of these simulations provided by the tests carried out at the Test Center of Kastaş Sealing Technologies. As a result of optimization activities, the load carrying ability of the composite hydraulic bearing element has been increased
Going native through archaeology: the impact of british explorers and archaeologists in the Ottoman Empire in the 19th Century
Once Burned, Twice Shy: Money Market Fund Responses to a Systemic Liquidity Shock
After Lehman's collapse in 2008, investors ran from risky money market funds. In 27 funds, outflows overwhelmed cash inflows, thus forcing asset sales. These funds sold their safest and most liquid holdings. Funds were thus left with riskier and longer maturity assets. Over the subsequent quarter, however, the hard-hit funds reduced risk more than other funds. In contrast, money funds hit by idiosyncratic liquidity shocks before Lehman did not alter portfolio risk. The result suggests that moral hazard concerns with the Treasury Guarantee of investor claims did not increase risk taking. Funds that benefited most from the government bailout reduced risk. Copyright © Michael G. Foster School of Business 2015
The Effect of Agility and Speed Training of Futsal Players Attending School of Physical Education and Sports on Aerobic Endurance
Futsal is ateam game with hibg phsical demands players. Agility, aerobic and anaerobic power outputs of the players support the success in the game. 24 male players attending the Kafkas University having played futsal in the school team for at least one year participated in the study. The players were separated into two groups, The experimental group (G1) performed sprints and circuits (agility training) of 10 m and 20 m integrated into a 30 minute training program after typical futsal training with their coach two days per week (Tuesdays and Thursdays) for six weeks. Additionally, on Thursdays, they participated in collective running at various paces, interval starts, and rank run exercises for aerobic endurance after typical futsal training. The control group (G2) performed their typical futsal training with their coach. The training sessions were planned so that there was at least a period of 36 hours between the two practice days. In order to determine the players’ speed capacity, 10 m-20 m speed tests, a reactive agility tests, and aerobic endurance measurement yo-yo tests were implemented. Descriptive statistics were used in the data analysis, the Mann-Whitney U test was used in comparative analysis of the groups, and the significance was taken to be p<0.05. At the end of the study, it was revealed that the agility training of futsal players attending university for six weeks had an effect on their aerobic endurance
FACTS BRIEF: TEXAS TAXES
This fact book provides: (1) a basic enumeration and explanation of the general taxes that make up the bulk of state and local tax revenues in Texas, (2) an evaluation of the impact of each major tax on efficiency, competitiveness, administrative simplicity, adequacy, and equity, and (3) a glossary of commonly used terms and concepts relating to taxation and public revenue. No attempt is made, herein, to present the numerous user fees, licenses, and other charges that may be imposed by state and local governments to pay for some public facilities and services.Public Economics,
Türk şirket birleşmelerinin satın alınan şirketlerin hisse senedi fiyatları üzerindeki etkileri
Cataloged from PDF version of article.This paper investigates stock-market reactions to mergers and partial sales of non-financial
Turkish firms. Turkish targets earn average cumulative abnormal returns (CAR) of 8.56
percent in the three-day window around merger announcements when bidders purchase
control rights and 2.25 percent when they do not. The results indicate that acquirers pay a
premium to purchase control rights. The smaller magnitude of target CAR in Turkish mergers
(relative to CAR of around 20 percent in US and 10 percent in Europe) may be explained by:
1) the reduction in the power of event study method to capture the effect of merger
announcements due to information leakages and misidentification of announcement dates; and
2) the differences in Turkish regulatory, operational and competitive environment
A comparison of artificial neural network and multinomial logit models in predicting mergers
Cataloged from PDF version of article.A merger proposal discloses a bidder firm's desire to purchase the control rights in a target firm. Predicting who will propose (bidder candidacy) and who will receive (target candidacy) merger bids is important to investigate why firms merge and to measure the price impact of mergers. This study investigates the performance of artificial neural networks and multinomial logit models in predicting bidder and target candidacy. We use a comprehensive data set that covers the years 19792004 and includes all deals with publicly listed bidders and targets. We find that both models perform similarly while predicting target and non-merger firms. The multinomial logit model performs slightly better in predicting bidder firms
Banking Geography and Cross-Fertilization in the Productivity Growth of US Commercial Banks
The US banking industry offers a unique, natural and fertile environment to study geography's effects on banks' behavior and performance. The literature on banks' operating performance, while extensive, says little about the influence of spatial interactions on banks' performance. We compute and examine, using a physical distance-based spatio-temporal empirical model, the state-wide total factor productivity growth (TFPG) indices of US commercial banks for each state for the 1971-1995 period. We observe that the productivity growth of commercial banks in state i depends strongly, positively, and contemporaneously on the productivity growth of commercial banks located in state i's contiguous states. Further, “regulatory space” appears to induce frictions and lessen the documented spatial interactions. These findings support our plea that research on commercial banking sector's behavior need to pay a particular attention to the effects of banking geography.Spatial, Commercial Banks, Total Factor Productivity Growth, Kalman Filter
Non-conventional viticulture as a viable system: a case study in Italy
The food crisis of 2008 and the current financial crisis, coupled with concerns of climate
change, have fueled a renewed interest in alternative food production systems, namely,
local, organic and sustainable food systems. In many countries, research shows that in the
medium to long run, organic and local food systems will be the most resistant and will
provide an effective means to attain food security. Moreover, such systems also support
social and cultural variables and can therefore be important in coping strategies in times
of crisis. Reliable, and sustainable systems will help bear the burden of crises as well as
be economically profitable as more people prefer to eat local due to environmental or
economic concerns. Organic or biodynamic production systems in a local setting offer
both economic and ecological advantages, from the producer and consumer perspectives.
While wine is not food, it supports a wide range of people, industries, and activities, and
therefore plays an important role in local economies, especially in countries like Italy. It
is also deeply rooted in tradition, and is rich in local knowledge and techniques. Wine is
also different in that its quality aspect is an important factor especially in terms of
customer acceptance. Wine is often highly differentiated, even within the same region.
The paper aims to provide a deeper understanding of the viability of the non-conventional
(organic/biodynamic) viticulture and proposes a model for analysis of its economic,
social and cultural context to measure impacts in an effort to evaluate the validity of the
argument that these types of systems are viable and even superior options. Interviews
with producers and local experts, and actual sales data will be used to identify the social,
environmental and economic advantages of such systems, as well as problems, such as
diseconomies of scale. Using selected indicators, the paper will also suggest policies to
overcome these problems and propose some marketing strategies to render such systems
more viable.
In particular, the paper will evaluate for a given locality in Italy:
(i) The profitability for the producer in the actual global and regional context,
with competition from larger and conventional producers
(ii) The probability of such methods to generate positive externalities from field
to glass
(iii) The feasibility of providing a higher quality product at a reasonable price for
the consumer
(iv) The direct and indirect impacts of this type of system for the local economy.
(v) Social aspects in terms of trust and a closer connection between consumers
and producers
(vi) Environmental/ecological implications
The above analysis will then be used to describe the particular viticulture system and
select indicators for social, economic and environmental viability. These will be used in
defining selected policy measures to minimize the costs and negative impacts and help
define targeted marketing strategies
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