Empirical studies on share issuance and repurchase decisions

Financial constraints influence corporate policies of firms, including both investment decisions and external financing policies. The relevance of this phenomenon has become more pronounced during and after the recent financial crisis in 2007/2008. In addition to raising costs of external financing, the effects of financial crisis limited the availability of external financing which had implications for employment, investment, sale of assets, and tech spending. This thesis provides a comprehensive analysis of the effects of financial constraints on share issuance and repurchases decisions. Financial constraints comprise both internal constraints reflecting the demand for external financing and external financial constraints that relate to the supply of external financing. The study also examines both operating performance and stock market reactions associated with equity issuance methods. The first empirical chapter explores the simultaneous effects of financial constraints and market timing on share issuance decisions. Internal financing constraints limit firms’ ability to issue overvalued equity. On the other hand, financial crisis and low market liquidity (external financial constraints) restrict availability of equity financing and consequently increase the costs of external financing. Therefore, the study explores the extent to which internal and external financing constraints limit market timing of equity issues. This study finds that financial constraints play a significant role in whether firms time their equity issues when the shares are overvalued. The conclusion is that financially constrained firms issue overvalued equity when the external equity market or the general economic conditions are favourable. During recessionary periods, costs of external finance increase such that financially constrained firms are less likely to issue overvalued equity. Only unconstrained firms are more likely to issue overvalued equity even during crisis. Similarly, small firms that need cash flows to finance growth projects are less likely to access external equity financing during period of significant economic recessions. Moreover, constrained firms have low average stock returns compared to unconstrained firms, especially when they issue overvalued equity. The second chapter examines the operating performance and stock returns associated with equity issuance methods. Firms in the UK can issue equity through rights issues, open offers, and private placement. This study argues that alternative equity issuance methods are associated with a different level of operating performance and long-term stock returns. Firms using private placement are associated with poor operating performance. However, rights issues are found empirically to be associated with higher operating performance and less negative long-term stock returns after issuance in comparison to counterpart firms that issue private placements and open offers. Thus, rights issuing firms perform better than open offers and private placement because the favourable operating performance at the time of issuance generates subsequent positive long-run stock price response. Right issuing firms are of better quality and outperform firms that adopt open offers and private placement. In the third empirical chapter, the study explores the levered share repurchase of internally financially unconstrained firms. Unconstrained firms are expected to repurchase their shares using internal funds rather than through external borrowings. However, evidence shows that levered share repurchases are common among unconstrained firms. These firms display this repurchase behaviour when they have bond ratings or investment grade ratings that allow them to obtain cheap external debt financing. It is found that internally financially unconstrained firms borrow to finance their share repurchase when they invest more. Levered repurchase firms are associated with less positive abnormal returns than unlevered repurchase firms. For the levered repurchase sample, high investing firms are associated with more positive long-run abnormal stock returns than low investing firms. It appears the market underreact to the levered repurchase in the short-run regardless of the level of investments. These findings indicate that market reactions reflect both undervaluation and signaling hypotheses of positive information associated with share repurchase. As the firms undertake capital investments, they generate future cash flows, limit the effects of leverage on financial distress and ultimately reduce the risk of the equity capital.

Machtverhältnisse und die Problematik des postkolonialen Blicks in Uwe Timms Morenga (1978) und Gerhard Seyfrieds Herero (2003)

Using a postcolonial methodology within a German Cultural Studies framework, this thesis applies a close reading to Uwe Timm’s 1978 novel Morenga and Gerhard Seyfried’s 2003 novel Herero. Both novels narrate the colonial experience in German Southwest Africa during the 1904-1907 Herero and Nama uprising through the eyes of a German male protagonist. I investigate how notions of the ‘other’ become ingrained in the collective cultural imaginary of a nation and manifest themselves as inherent truths used to justify methods of subjugation. I also examine the conflicts that arise due to the clash between these drastically different cultures in the “contact zone”, a term I borrow from Mary Louise Pratt. Emphasis is placed on analyzing the ways in which the natives’ use of mimicry allows for the creation of a cultural hybridity in which power relations are constantly negotiated and re-evaluated. I also problematize the difficulty both protagonists demonstrate in their quest to abandon the colonial gaze in favor of adopting a postcolonial perspective, an attempt that often appears ambivalent at best.

Hardpan and maize root distribution under conservation and conventional tillage in Agro-Ecological Zone IIA, Zambia

Hardpans (plough/hoe pans) are commonly believed to restrict plant root growth and crop yields under conventional small-scale agriculture in sub-Saharan Africa. This study questions the notion of widespread hardpans in Zambia and their remedy under conservation tillage. Soil penetration resistance was measured in 8x12 grids, covering 80 cm wide and 60 cm deep profiles in 32 soil pits. Large and fine maize roots were counted in 8x6 grids. Soil samples from mid-rows were analysed for pH, exchangeable H+, exchangeable Al3+, cation exchange capacity, total N and extractable P (Bray 1) at six depths from 0-10 to 50-60 cm. Cultivation-induced hardpans were not detected. Soils under conservation tillage were more compact at 5 cm depth than soils under conventional tillage. No differences in root distributions between conservation and conventional tillage were found. Maize ( Zea mays L. ) roots were largely confined to a relatively small soil volume of about 30 cm x 30 cm x 30 cm. Root growth appeared to be restricted by a combination of low concentrations of N and P. Soil acidity and Al saturation appeared to play a minor role in root distribution. L-shaped taproots in soils under manual tillage reported earlier were not necessarily due to hardpans, but may rather be caused by temporarily dry, impenetrable subsoils early in the rain season. There is no scientific basis for the recommendation given to farmers by agricultural extension workers to “break the hardpan” in fields under manual or animal tillage in the study areas.

Physical Design Methodologies for Low Power and Reliable 3D ICs

As the semiconductor industry struggles to maintain its momentum down the path following the Moore's Law, three dimensional integrated circuit (3D IC) technology has emerged as a promising solution to achieve higher integration density, better performance, and lower power consumption. However, despite its significant improvement in electrical performance, 3D IC presents several serious physical design challenges. In this dissertation, we investigate physical design methodologies for 3D ICs with primary focus on two areas: low power 3D clock tree design, and reliability degradation modeling and management. Clock trees are essential parts for digital system which dissipate a large amount of power due to high capacitive loads. The majority of existing 3D clock tree designs focus on minimizing the total wire length, which produces sub-optimal results for power optimization. In this dissertation, we formulate a 3D clock tree design flow which directly optimizes for clock power. Besides, we also investigate the design methodology for clock gating a 3D clock tree, which uses shutdown gates to selectively turn off unnecessary clock activities. Different from the common assumption in 2D ICs that shutdown gates are cheap thus can be applied at every clock node, shutdown gates in 3D ICs introduce additional control TSVs, which compete with clock TSVs for placement resources. We explore the design methodologies to produce the optimal allocation and placement for clock and control TSVs so that the clock power is minimized. We show that the proposed synthesis flow saves significant clock power while accounting for available TSV placement area. Vertical integration also brings new reliability challenges including TSV's electromigration (EM) and several other reliability loss mechanisms caused by TSV-induced stress. These reliability loss models involve complex inter-dependencies between electrical and thermal conditions, which have not been investigated in the past. In this dissertation we set up an electrical/thermal/reliability co-simulation framework to capture the transient of reliability loss in 3D ICs. We further derive and validate an analytical reliability objective function that can be integrated into the 3D placement design flow. The reliability aware placement scheme enables co-design and co-optimization of both the electrical and reliability property, thus improves both the circuit's performance and its lifetime. Our electrical/reliability co-design scheme avoids unnecessary design cycles or application of ad-hoc fixes that lead to sub-optimal performance. Vertical integration also enables stacking DRAM on top of CPU, providing high bandwidth and short latency. However, non-uniform voltage fluctuation and local thermal hotspot in CPU layers are coupled into DRAM layers, causing a non-uniform bit-cell leakage (thereby bit flip) distribution. We propose a performance-power-resilience simulation framework to capture DRAM soft error in 3D multi-core CPU systems. In addition, a dynamic resilience management (DRM) scheme is investigated, which adaptively tunes CPU's operating points to adjust DRAM's voltage noise and thermal condition during runtime. The DRM uses dynamic frequency scaling to achieve a resilience borrow-in strategy, which effectively enhances DRAM's resilience without sacrificing performance. The proposed physical design methodologies should act as important building blocks for 3D ICs and push 3D ICs toward mainstream acceptance in the near future.

Galvanic corrosion of two non noble dental alloys

Artigo licenciado sob uma Licença Creative Commons: https://creativecommons.org/licenses/by/4.0/

Removal of BrO3 − from drinking water samples using newly developed agricultural waste-based activated carbon and its determination by ultra-performance liquid chromatography-mass spectrometry

Activated carbon was prepared from date pits via chemical activation with H3PO4. The effects of activating agent concentration and activation temperature on the yield and surface area were studied. The optimal activated carbon was prepared at 450 °C using 55 % H3PO4. The prepared activated carbon was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric-differential thermal analysis, and Brunauer, Emmett, and Teller (BET) surface area. The prepared date pit-based activated carbon (DAC) was used for the removal of bromate (BrO3 −). The concentration of BrO3 − was determined by ultra-performance liquid chromatography-mass tandem spectrometry (UPLC-MS/MS). The experimental equilibrium data for BrO3 − adsorption onto DAC was well fitted to the Langmuir isotherm model and showed maximum monolayer adsorption capacity of 25.64 mg g−1. The adsorption kinetics of BrO3 − adsorption was very well represented by the pseudo-first-order equation. The analytical application of DAC for the analysis of real water samples was studied with very promising results.

School Anxiety Inventory: Reliability and Validity Evidence in a Sample of Slovenian Adolescents

The purpose of this study was to examine the reliability and validity of the School Anxiety Inventory (SAI) using a sample of 646 Slovenian adolescents (48% boys), ranging in age from 12 to 19 years. Single confirmatory factor analyses replicated the correlated four-factor structure of scores on the SAI for anxiety-provoking school situations (Anxiety about School Failure and Punishment, Anxiety about Aggression, Anxiety about Social Evaluation, and Anxiety about Academic Evaluation), and the three-factor structure of the anxiety response systems (Physiological Anxiety, Cognitive Anxiety, and Behavioral Anxiety). Equality of factor structures was compared using multigroup confirmatory factor analyses. Measurement invariance for the four- and three-factor models was obtained across gender and school-level samples. The scores of the instrument showed high internal reliability and adequate test–retest reliability. The concurrent validity of the SAI scores was also examined through its relationship with the Social Anxiety Scale for Adolescents (SASA) scores and the Questionnaire about Interpersonal Difficulties for Adolescents (QIDA) scores. Correlations of the SAI scores with scores on the SASA and the QIDA were of low to moderate effect sizes.

Aplicação de técnicas eletroquímicas na determinação do potencial de corrosividade de ligas de alumínio em água produzida

The resistance of aluminum and their alloys, to the corrosion phenomenon, in aqueous solutions, is a result of the oxide layer formed. However, the corrosion process in the aluminum alloy is associated with the presence a second phase of particles or the presence of chloride ions which promote the disruption of the oxide layer located producing the corrosion process. On the other hand, the term water produced is used to describe the water after the separation of the oil and gas in API separators. The volumes of produced water arrive around 5 more times to the volume of oil produced. The greatest feature of the water is the presence of numerous pollutants. Due to the increased volume of waste around the world in the current decade, the outcome and the effect of the discharge of produced water on the environment has recently become an important issue of environmental concern where numerous treatments are aimed at reducing these contaminants before disposal. Then, this study aims to investigate the electrochemical corrosion behavior of aluminum alloy 6060 in presence of water produced and the influence of organic components as well as chloride ions, by using the electrochemical techniques of linear polarization. The modification of the passive layer and the likely breakpoints were observed by atomic force microscopy (AFM). In the pit formation potential around -0.4 to -0.8 V/EAg/AgCl was observed that the diffusion of chloride ions occurs via the layer formed with the probable formation of pits. Whereas, at temperatures above 65 °C, it was observed that the range of potential for thepit formation was -0.4 to -0.5 V/EAg/AgCl. In all reactions, the concentration of Al(OH)3 in the form of a gel was observed

Dynamics and diversity of Escherichia coli in animals and system management of the manure on a commercial farrow-to-finish pig farm

The objective of this study was to determine the dynamics and diversity of Escherichia coli populations in animal and environmental lines of a commercial farrow-to-finish pig farm in Spain along a full production cycle (July 2008 to July 2009), with special attention to antimicrobial resistance and the presence of integrons. In the animal line, a total of 256 isolates were collected from pregnant sows (10 samples and 20 isolates), 1-week-old piglets (20 samples and 40 isolates), unweaned piglets (20 samples and 38 isolates), growers (20 samples and 40 isolates), and the finishers' floor pen (6 samples and 118 isolates); from the underfloor pits and farm slurry tank environmental lines, 100 and 119 isolates, respectively, were collected. Our results showed that E. coli populations in the pig fecal microbiota and in the farm environment are highly dynamic and show high levels of diversity. These issues have been proven through DNA-based typing data (repetitive extragenic palindromic PCR [REP-PCR]) and phenotypic typing data (antimicrobial resistance profile comprising 19 antimicrobials). Clustering of the sampling groups based on their REP-PCR typing results showed that the spatial features (the line) had a stronger weight than the temporal features (sampling week) for the clustering of E. coli populations; this weight was less significant when clustering was performed based on resistotypes. Among animals, finishers harbored an E. coli population different from those of the remaining animal populations studied, considering REP-PCR fingerprints and resistotypes. This population, the most important from a public health perspective, demonstrated the lowest levels of antimicrobial resistance and integron presence.

Dairy Farm Layout and Design: Building and Yard Design, Warm Climates

The current knowledge revised in this article describes a wide range of facilities in common use on dairy cattle farms in warm climates. A dairy cattle farm consists of several facilities, such as housing system, yards, manure pits, milking center, environmental protection structures, forage storage, and several machines for different facilities. Any facility design tends to be a compromise, often between many factors, and no single solution will be optimal for all concerned.

Deindustrialisation and industrial communities: the Lanarkshire coalfields c.1947-1983

This thesis examines deindustrialisation, the declining contribution of industrial activities to economic output and employment, in Lanarkshire, Scotland’s largest coalfield between the early nineteenth and mid-twentieth century. It focuses on contraction between the National Coal Board’s (NCB) vesting in 1947 and the closure of Lanarkshire’s last colliery, Cardowan, in 1983. Deindustrialisation was not the natural outcome of either market forces or geological exhaustion. Colliery closures and falling coal employment were the result of policy-makers’ decisions. The thesis consists of four thematic chapters: political economy, moral economy, class and community, and generation and gender. The analysis is based on archival sources including Scottish Office reports and correspondence relating to regional policy, and NCB records. These are supported by National Union of Mineworkers Scottish Area and STUC meeting minutes, and oral history testimonies from over 30 men and women with Lanarkshire coalfield backgrounds, as well as two focus groups. The first two chapters analyse the process of deindustrialisation, with the first offering a top-down perspective and the second a bottom-up viewpoint. In chapter one deindustrialisation is analysed through changes in political economy. Shifts in labour market structure are examined through the development of regional policy and its administration by the Scottish Office. The analysis centres upon a policy network of Scottish business elites and civil servants who shaped a vision of modernisation via industrial diversification through attracting inward investment. In chapter two the perspective shifts to community and workforce. It analyses responses to coalfield contraction through a moral economy of customary rights to colliery employment. A detailed investigation of Lanarkshire colliery closures between the 1940s and 1980s emphasises the protracted nature of deindustrialisation. Chapters three and four consider the social and cultural structures which shaped the moral economy but were heavily altered by deindustrialisation. Chapter three focuses on the dense networks that linked occupation, community, and class consciousness. Increasing coalfield centralisation and remote control of pits from NCB headquarters in London, and mounting hostility to coal closures, contributed to an accentuated sense of Scottish-ness. Chapter four illuminates gender and generational dimensions. The differing experiences of cohorts of men who faced either early retirement, redundancy or transfer to alternative sectors, or those who never attained anticipated industrial employment due to final closures, are analysed in terms of constructions of masculinity and the endurance of cultural as well as material losses. This is counterpoised to women who gained industrial work in assembly plants and the perceived gradual attainment of an improved economic and social position whilst continuing to navigate structures of patriarchy.

Economic feasibility analysis of the implementation of a high value-added molecule extraction system in an olive oil mill

The production of olive oil generates several by-products that can be seen as an additional business opportunity. Among them are the olive pits, already used for heat and/or electricity generation in some mills. They contain compounds that are commercially very interesting and, if recovered, contribute to the sustainability of the olive mills. The work presented in this paper is a preliminary evaluation of the economic feasibility of implementing a system based on a batch prototype with 1 m3 for the extraction of high value-added bioactive molecules from olive pits that are separated during the production of virgin olive oil. For the analysis, a small representative olive mill in Portugal was considered and the traditional Discounted Cash Flow Method was applied. Based on the assumptions made, the simple payback for implementation a system for the extraction of value-added molecules from the olive pits is around 7 years.