bluuebunny/crossref_metadata_2025 huggingface dataset:
Business cycle management and firm performance
Authors: Navarro Peter , Bromiley Philip , Sottile Pedro
Published: February 2010

Purpose

Business cycles strongly influence corporate sales and profits, yet strategy research largely ignores the possibility that corporate management practices related to the business cycle influence profitability. This paper aims to offer initial empirical support for the view that high peformance firms use a variety of business cycle management (BCM) practices that low performance firms do not.

Design/methodology/approach

This exploratory study examines the association of firm performance with business cycle management behaviors identified in the prescriptive literature and further developed from a set of case analyses. The empirical analysis uses a matched sample of 35 pairs of high vs low performers from the S&P 500.

Findings

Discriminant and conditional logit analyses provide preliminary evidence that business cycle‐sensitive behaviors such as countercyclical hiring and investment associate positively with firm performance.

Research limitations/implications

Future research should use larger data sets and strictly archival data to overcome the limitations of the small sample size and data coding with some subjective elements.

Practical implications

This research suggests a variety of business cycle related practices dealing with staffing, capital investment, acquisitions and divestitures, capital financing, credit policy, pricing, and advertising may improve firm performance.

Originality/value

This is the first paper to offer evidence of the impact of business cycle related practices across a range of practices and industries.
A serial successful strategic transformer of businesses
Authors: O'Regan Nicholas , Ghobadian Abby
Published: February 2010

Purpose

The purpose of this paper is to demonstrate how key strategic decisions are made in practice at successful FTSE 100 companies.

Design/methodology/approach

The paper is based on a semi‐structured interview with the Chairman of Whitbread plc, Reed Elsevier plc, Mr Anthony Habgood. Mr Habgood has a track record in successfully achieving corporate strategic transformation.

Findings

The paper sheds light on ingredients of successful strategy formulation and implementation, corporate strategic transformation, key elements of successful mergers and acquisitions and leadership as a vital ingredient in corporate performance.

Research limitations/implications

The paper presents views of a successful and highly regarded Chairman of two FTSE 100 companies. Mr Habgood was also the Chief Executive of a third FTSE 100 company. It provides an insight on how strategy is made and executed.

Originality/value

The paper bridges the gap between theory and practice. It provides a practical view and demonstrates how corporate leaders think about key strategic issues.
Does awareness to climate change lead to behavioral change?
Authors: Halady Indrani R. , Rao Purba H.
Published: February 2010

Purpose

The purpose of this paper is to investigate whether awareness to climate change and its adverse impacts have any significant linkages to behavioral changes amongst individual managers who undertake initiatives to minimize/mitigate the impacts.

Design/methodology/approach

A theoretical framework based on different aspects of awareness possibly leading to behavior change has been proposed. Subsequently, the results from an empirical research based on a survey questionnaire as research instrument, are analyzed using exploratory factor analysis and structural equation modeling to validate the framework and the research question.

Findings

Awareness to the climate change phenomenon does lead to significant behavioral change amongst managers in the industry, alleviating the potential and existing threats of climate change phenomenon. In particular, the awareness to health impacts of climate change has significantly impacted individuals taking up the cause to lead climate change campaigns to counter its onslaught.

Research limitations/implications

The research is conducted in a population confined to a single region in India. Its scope needs to be broadened to encompass the entire country.

Originality/value

The findings should lead to widespread awareness campaigns emphasizing on awareness to adverse health disorders as a direct result of climate change and its other adverse impacts, and also the individual initiatives that can be taken up as well as what the industry can do.
Defining and assessing the risk of being harmed by climate change
Authors: Pascal Briguglio Lino
Published: February 2010

Purpose

The purpose of this paper is to assess the risk of a population in a given territory being harmed by climate change by distinguishing between: natural factors, which are associated with inherent vulnerability; and man‐made or policy‐induced factors, which are associated with adaptation. It is argued that this distinction is useful as a methodological approach and for policy making.

Design/methodology/approach

The approach utilises indices of vulnerability and adaptation, and juxtaposes them to arrive at an assessment of risk.

Findings

The major findings of this paper are that the “lowest‐risk” or “managed‐risk” category of territories are mostly port cities in high‐income countries, whereas the “mismanaged‐risk” and “highest‐risk” category of territories are vulnerable port cities located in low‐income countries.

Originality/value

The originality of the paper is that it highlights the distinction between natural and man‐made risks in arriving at a total assessment of risk – a distinction of utmost importance for policy making. An important, although obvious, conclusion is that adaptation does not reduce the inherent vulnerability of the territories concerned, but it serves to enable humans to withstand, bounce back from or absorb the effects of vulnerability to climate change.
The role of afforestation programme in combating desertification in Nigeria
Authors: Idris Medugu Nasiru , Rafee Majid M. , Johar Foziah , Choji I.D.
Published: February 2010

Purpose

The purpose of this paper is to determine the extent to which an afforestation programme as spelt out in the Forestry II programme has checked the encroachment of desert in the arid and semi‐arid zone of northern Nigeria.

Design/methodology/approach

The study is carried out in the afforestation project states aimed at evaluating the success/failure of the program. Field observation and a site visit are conducted on some communities as well as policies relevant to forestry sector are reviewed.

Findings

The preliminary findings of this paper indicate that the afforestation projects had a positive impact on both biophysical and socioeconomic environment and contributed to the sustainability of the afforestation programme.

Research limitations/implications

This paper is primarily focused on the various components of the Forestry II programme and the extent they have helped in combating desertification.

Originality/value

The paper addresses the need for sustainable afforestation projects and discusses on how the community effort and participation of women plays an important role during the afforestation programs.
Biodiversity and climate change in Kuwait
Authors: Omar Asem Samira , Roy Waleed Y.
Published: February 2010

Purpose

The purpose of this paper is to demonstrate the various consequences of climate change on the biodiversity of Kuwait. Many world organizations have established strategic plans for climate change, such as The Global Strategy for Plant Conservation, which is adopted in 2002 by the Conference of the Parties of the Convention on Biological Diversity.

Design/methodology/approach

The paper utlizes a wide range of research projects completed at the Kuwait Institute for Scientific Research (KISR), which provide information leading to the degradding effects and risks of climate change on the biodiversity and ecosystem services of Kuwait.

Findings

The biodiversity of Kuwait is under severe stress due to natural and anthropogenic factors. The region is also threatened physically and biologically by the global warming phenomena. More severe and harsh climatic conditions will cause increase in formation of sand dunes, sand encroachment, and extreme dust storms. In 2008, Kuwait has the worst ever reported summer since 1991 with increase in intensity and frequency of dust storms. Drought will cause more water demand for local consumption and irrigation. The seawater temperature increase would affect the spawning period of fish and shrimp and would cause migration of fish to other more suitable areas. This would cause severe impact on the fish industry in Kuwait and the region. Losses in plant cover will be due to sand encroachment or erratic rainfall periods causing runoff and flooding.

Research limitations/implications

The work is based on various projects at the KISR and by some journal publications that relate to climate change impact on biodivesity. More research work is needed to test the long‐term impact of climate change on bidivesity of Kuwait.

Originality/value

There is a need to develop a strategic plan for climate change mitigation and adaptation in Kuwait. Specific elements of the plan would include: research for identification of vulnerable species, collecting field population data, conducting modeling research to inform conservation programs; monitoring key species; ex situ conservation using living collection and ensuring representation in conservation collection; in situ conservation and increase in protected areas; education and public awareness programs; networking; and sharing knowledge.
Adapting production forests in southern Sweden to climate change
Authors: Felton Adam , Ellingson Lindsey , Andersson Erik , Drössler Lars , Blennow Kristina
Published: February 2010

Purpose

Recent climate scenarios indicate that Sweden's southern region, Götaland, will experience significant climate change over the coming century. Swedish forestry policy guidelines emphasize the need for risk spreading to reduce the potential adverse impacts of these changes. Risk spreading is defined here as reducing the vulnerability of a social‐ecological system by increasing the heterogeneity of its ecological components. Risk spreading may be achieved through the diversification of tree species currently relied upon by the forestry sector. The purpose of this paper is to consider the capacity of the socio‐ecological forest system to adapt to climate change through the use of risk spreading.

Design/methodology/approach

A variety of disciplines contribute to the understanding of the rate at which risk spreading is likely to take place in a system. A synthesis is conducted to unite these insights.

Findings

Five key constraints on the rate at which risk spreading can take place are identified. These include constraints imposed by the silvicultural system itself, voluntary policy measures, forest‐owner perceptions of climate change, motivation among forest owners to respond to risk, and forestry consultants. Potential future directions are discussed and include the need for specifying the goal of risk spreading policy, and the need to evaluate the motivations of those forest owners already altering adopting risk spreading approaches.

Originality/value

Conceptual equivalents of the “risk spreading” approach are international, due to the need for many societies to adapt social‐ecological systems to climate change. The issues raised from this case study/synthesis provide value insights regarding the breadth of systemic constraints which can thwart attempts at rapid adjustment to climate change, and where solutions to these constraints may be found.
Quality of the external auditor, information asymmetry, and bid‐ask spread
Authors: Hakim Faten , Omri Mohamed Ali
Published: February 2010

Purpose

The purpose of this paper is to examine the relationship between information asymmetry and the quality of the external audit in the Tunisian capital market.

Design/methodology/approach

The paper uses panel data methodology.

Findings

The results show that the bid‐ask, a market‐based measure of information asymmetry, is negatively related to the employment of an industry specialist and big auditors; and positively related to audit firm tenure. However, further tests refine those conclusions, in that the positive association between tenure and bids‐ask spread differs between specialist and non‐specialist auditors and between Big 4 and non‐Big 4 auditors. Specifically, the paper finds that bid‐ask spreads is increasing in tenure for clients of non‐specialist and clients of non‐Big 4.

Research limitations/implications

The difficulties in specifying correct models for determining the audit quality, the research analyze the auditor's quality such as big auditor, tenure, and specialist. The paper leaves this and other issues for future research.

Originality/value

Analyzing the effect of auditor's quality on information asymmetry and bid‐ask spreads is an emerging economy such as Tunisia is very appealing because earnings quality is the most important quality investors look for. And this research makes a link between two important areas of auditing and finance.
Leverage, liquidity and IPO long‐run performance: evidence from Taiwan IPO markets
Authors: Chen Anlin , Chen Li‐Wei , Kao Lanfeng
Published: February 2010

Purpose

The purpose of this paper is to examine the long‐run performance of initial public offerings (IPOs) in Taiwan with a five‐factor model on a calendar time basis.

Design/methodology/approach

Besides the Fama‐French three factors, the paper also incorporates leverage and liquidity into the factor model to measure IPO five‐year performance. The sample consists of 261 IPOs issued in Taiwan over‐the‐counter during 1991 and 2002. The actual data cover the period from January 1991 to December 2007.

Findings

Contrary to findings of previous studies on US IPO markets, the paper finds that Taiwan IPOs experience better long‐run performance than the market even after adjusting for the common factors in the capital markets.

Originality/value

This paper argues that survival rate of Taiwan IPOs would be the reason why Taiwan IPOs do not underperform in the long run.
Information technology implementation: evidence in Spanish SMEs
Authors: Pérez Estébanez Raquel , Urquía Grande Elena , Muñoz Colomina Clara
Published: February 2010

Purpose

The purpose of this paper is to use empirical evidence to measure if the small and medium enterprises (SMEs) have adapted to information technologies (ITs) and analyse the extent of IT knowledge and interest in new international accounting standards as factors that align strategies and organizational culture towards continuous improvement.

Design/methodology/approach

The empirical study acquires knowledge of the situation of SMEs in Spain and carries out an analysis of variables based on the results. Contingency tables have been developed to find out whether there are dependent‐effect relationships between the survey items.

Findings

When analysing the sample by sectors, the paper finds that the manufacturing sector has a high level of short‐term IT implementation, using it to deal with accounting, fiscal and financial issues, while the services sector is using IT intensively and is also very interested in sophisticated IT. Moreover, research results reveal a trend towards continuous improvement of Spanish SMEs of all sizes in all sectors as the majority show considerable interest in international accounting standards.

Research limitations/implications

The study has some limitations such as the way in which data are obtained, determining the type and number of questions and the fact that a majority of those responding to the survey are medium‐sized businesses. In addition, those answering are the accounting department managers, leading to a possible bias if the paper tries to extrapolate the results.

Originality/value

This paper provides new information for SMEs, public administrations and academics. The increasing interest in the subject can lead to additional research with causal relationships between IT implementation, SMEs strategy and financial results.
Rethinking MBA accounting module teaching, assessment and curriculum design
Authors: Tse Chin‐Bun
Published: February 2010

Purpose

The purpose of this paper is to investigate Master of Business Administration (MBA) students' performance in handling alternative types of accounting questions in order to generate some insights for future MBA accounting module teaching and assessment design.

Design/methodology/approach

The paper employs two approaches: first, statistical analysis is used on a large sample of MBA students' accounting modules results on two different types of questions. Second, common problems are identified from the assessments and summarized for analysis.

Findings

There is a statistically significant difference in performance between two types of assessment methods. The difference can be logically explained from analyzing the common problems identified in MBA students' accounting assessment scripts.

Research limitations/implications

This paper provides only preliminary findings for the purpose of “rethinking” of future MBA accounting module design. Further work is required to investigate the impacts of MBA students' personal characteristics, e.g. year of working experience, first degree discipline, etc. on their accounting module performance.

Practical implications

This paper provides some important practical insights that suggest that the current MBA accounting module design “may be” incorrect in terms of topic coverage, delivery schedule and expectation.

Originality/value

The paper will initiate a new debate on how future MBA accounting modules should be, and how to teach and assess it.
Nitrate leaching from cut grassland as affected by the substitution of slurry with nitrogen mineral fertilizer on two soil types
Authors: Schröder J. J. , Assinck F. B. T. , Uenk D. , Velthof G. L.
Published: February 2010

A field experiment was conducted to find out whether there is any difference in risk of N leaching to groundwater when cattle slurry and/or mineral fertilizer‐N was applied to cut grassland. The experiment was carried out over two consecutive years on two sites (one with a relatively wet sandy soil and one with a relatively dry sandy soil). Treatments were mineral fertilizer‐N at annual rates of 0–510 kg N ha−1 year−1 and combinations of sod‐injected cattle slurry (85, 170, 250 and 335 kg N ha−1 year−1) and mineral fertilizer‐N (289, 238, 190 and 139 kg N ha−1 year−1). Yield responses indicated that in the short run, 0·44–0·88 (average 0·60) of the slurry‐N was as available as mineral fertilizer‐N. The total N input from mineral fertilizer and slurry was a worse predictor of nitrate leaching ( 0·11) than the N surplus (i.e. the difference between total N input and harvested N) ( 0·60). The effective N surplus, based on the difference between the summed inputs of the plant‐available N and harvested N, proved to be the best indicator of leaching ( 0·86). Annual N application rates of up to 340 kg plant‐available N ha−1 complied with the target nitrate concentration in groundwater of 11·3 mg N L−1 set by the European Union in both years on the wet sandy soil, whereas on the dry sandy soil none of the treatments did.
Effect of humic substances on nutrient uptake by herbage and on production and nutritive value of herbage from sown grass pastures
Authors: Verlinden G. , Coussens T. , De Vliegher A. , Baert G. , Haesaert G.
Published: February 2010

The effect of humic substances on the nutrient uptake, herbage production and nutritive value of herbage from sown grass pastures was studied in six field experiments. Commercial humic substances were applied in combination with mineral fertilizer or slurry, either as a solution (HF liquid; 8·3 kg humic substances ha−1) or incorporated into the mineral fertilizer (HF incorporated; 3·6 to 6·4 kg humic substances ha−1). A series of cuts, ranging from two to five cuts, was taken during the growing season. The general response in herbage production to application of humic substances was an increase in herbage mass of dry matter (DM) at the first cut although this was only significant in two experiments for the HF incorporated treatment. Total herbage production of DM over the growing season, however, was similar for treatments with or without application of humic substances. The overall effect of HF incorporated and HF liquid on the herbage mass of DM at the first cut across the experiments was calculated using a meta‐analysis technique and it was shown that there was a significant proportional increase of 0·14 (P < 0·05) with the HF incorporated treatment and a non‐significant increase of 0·08 with the HF liquid treatment compared to the control treatment. The nutritive value of the herbage at the first cut was similar across all treatments. In general nitrogen, phosphorus and potassium uptake at the first grass cut was higher after application of humic substances but only in one experiment was this increase statistically significant.
Niche saturation reveals resource partitioning among consumers
Authors: Northfield Tobin D. , Snyder Gretchen B. , Ives Anthony R. , Snyder William E.
Published: February 2010

Ecology Letters (2010) 13: 338–348

More diverse communities of consumers typically use more resources, which often is attributed to resource partitioning. However, experimentally demonstrating this role of resource partitioning in diverse communities has been difficult. We used an experimental response‐surface design, varying intra‐ and interspecific consumer densities, to compare patterns of resource exploitation between simple and diverse communities of aphid predators. With increasing density, each single consumer species rapidly plateaued in its ability to extract more resources. This suggests intraspecific competition for a subset of the resource pool, a hallmark of resource partitioning. In contrast, more diverse‐predator communities achieved greater overall resource depletion. By statistically fitting mechanistic models to the data, we demonstrated that resource partitioning rather than facilitation provides the better explanation for the observed differences in resource use between simple and diverse communities. This model‐fitting approach also allowed us to quantify overlap in resource use by different consumer species.
A structured and dynamic framework to advance traits‐based theory and prediction in ecology
Authors: Webb Colleen T. , Hoeting Jennifer A. , Ames Gregory M. , Pyne Matthew I. , LeRoy Poff N.
Published: February 2010

Ecology Letters (2010) 13: 267–283

Predicting changes in community composition and ecosystem function in a rapidly changing world is a major research challenge in ecology. Traits‐based approaches have elicited much recent interest, yet individual studies are not advancing a more general, predictive ecology. Significant progress will be facilitated by adopting a coherent theoretical framework comprised of three elements: an underlying trait distribution, a performance filter defining the fitness of traits in different environments, and a dynamic projection of the performance filter along some environmental gradient. This framework allows changes in the trait distribution and associated modifications to community composition or ecosystem function to be predicted across time or space. The structure and dynamics of the performance filter specify two key criteria by which we judge appropriate quantitative methods for testing traits‐based hypotheses. Bayesian multilevel models, dynamical systems models and hybrid approaches meet both these criteria and have the potential to meaningfully advance traits‐based ecology.
Production of pharmaceutical‐grade recombinant aprotinin and a monoclonal antibody product using plant‐based transient expression systems
Authors: Pogue Gregory P. , Vojdani Fakhrieh , Palmer Kenneth E. , Hiatt Ernie , Hume Steve , Phelps Jim , Long Lori , Bohorova Natasha , Kim Do , Pauly Michael , Velasco Jesus , Whaley Kevin , Zeitlin Larry , Garger Stephen J. , White Earl , Bai Yun , Haydon Hugh , Bratcher Barry
Published: February 2010

Plants have been proposed as an attractive alternative for pharmaceutical protein production to current mammalian or microbial cell‐based systems. Eukaryotic protein processing coupled with reduced production costs and low risk for mammalian pathogen contamination and other impurities have led many to predict that agricultural systems may offer the next wave for pharmaceutical product production. However, for this to become a reality, the quality of products produced at a relevant scale must equal or exceed the predetermined release criteria of identity, purity, potency and safety as required by pharmaceutical regulatory agencies. In this article, the ability of transient plant virus expression systems to produce a wide range of products at high purity and activity is reviewed. The production of different recombinant proteins is described along with comparisons with established standards, including high purity, specific activity and promising preclinical outcomes. Adaptation of transient plant virus systems to large‐scale manufacturing formats required development of virus particle and Agrobacterium inoculation methods. One transient plant system case study illustrates the properties of greenhouse and field‐produced recombinant aprotinin compared with an US Food and Drug Administration‐approved pharmaceutical product and found them to be highly comparable in all properties evaluated. A second transient plant system case study demonstrates a fully functional monoclonal antibody conforming to release specifications. In conclusion, the production capacity of large quantities of recombinant protein offered by transient plant expression systems, coupled with robust downstream purification approaches, offers a promising solution to recombinant protein production that compares favourably to cell‐based systems in scale, cost and quality.
The production of hemagglutinin‐based virus‐like particles in plants: a rapid, efficient and safe response to pandemic influenza
Authors: D’Aoust Marc‐André , Couture Manon M.‐J. , Charland Nathalie , Trépanier Sonia , Landry Nathalie , Ors Frédéric , Vézina Louis‐P.
Published: February 2010

During the last decade, the spectre of an influenza pandemic of avian origin has led to a revision of national and global pandemic preparedness plans and has stressed the need for more efficient influenza vaccines and manufacturing practices. The 2009 A/H1N1 (swine flu) outbreak has further emphasized the necessity to develop new solutions for pandemic influenza vaccines. Influenza virus‐like particles (VLPs)—non‐infectious particles resembling the influenza virus—represent a promising alternative to inactivated and split‐influenza virions as antigens, and they have shown uniqueness by inducing a potent immune response through both humoral and cellular components of the immune system. Our group has developed a plant‐based transient influenza VLP manufacturing platform capable of producing influenza VLPs with unprecedented speed. Influenza VLP expression and purification technologies were brought to large‐scale production of GMP‐grade material, and pre‐clinical studies have demonstrated that low doses of purified, plant‐produced influenza VLPs induce a strong and broad immune response in mice and ferrets. This review positions the recent developments towards the successful production of influenza VLPs in plants, including the production of VLPs from other human viruses and other forms of influenza antigens. The platform developed for large‐scale production of VLPs is also presented along with an assessment of the speed of the platform to produce the first experimental vaccine lots from the identification of a new influenza strain.
Exploring open search strategies and perceived innovation performance from the perspective of inter‐organizational knowledge flows
Authors: Chiang Yun‐Hwa , Hung Kuang‐Peng
Published: February 2010

Based on theories of inter‐organizational knowledge flows and organizational learning, we argue that intensively accessing knowledge from a limited number of external channels, i.e., open search depth, can facilitate the innovating company's incremental innovation performance. We also argue that accessing knowledge from a broad range of external channels, i.e., open search breadth, can enhance the innovating firm's radical innovation performance. Using hierarchical regressions to analyze survey data collected from 184 Taiwanese electronic product manufacturers, we found that open search depth is positively related to the innovating firm's incremental innovation performance, and that open search breadth is positively related to radical innovation performance. As our results differ from those of previous studies, we provide a possible explanation for the discrepancy. Examining the effect of open search strategy from a theoretical angle not yet explored before, our findings can contribute to both scholarly and practitioner knowledge of open innovation.
Nutritional status of children with coeliac disease
Authors: Aurangzeb B , Leach ST , Lemberg DA , Day AS
Published: February 2010

Aims:  The main aim of this study was to assess the nutritional status of children with newly diagnosed Coeliac disease (CD)with comparison to matched controls. A further aim was to assess relationships between presentation patterns and nutrition in childhood CD.

Methods:  The nutritional status of newly diagnosed CD was assessed by anthropometry, Bioelectrical Impedance and serum leptin levels, and contrasted to age and gender matched controls.

Results:  Twenty‐five children with CD (mean age of 8.2 ± 4.5 years) and 25 control children (mean age 8.1 ± 4.4.) were enrolled. Thirteen (52%) children with CD had gastrointestinal symptoms with 14 having a family history of CD. At presentation 8.7% were wasted, 4.2% were stunted and 20.8% overweight, although none were obese. Mean height and weight for age, other nutritional parameters and serum leptin did not differ between the groups. Serum leptin correlated with BMI in both groups.

Conclusions:  Children with CD more commonly present with atypical symptoms than with classical features. Variations in nutrition (under to overnutrition) may be seen at diagnosis, without relationship to the presence of symptoms. Leptin levels were not altered specifically in the setting of CD. Nutritional assessment remains important in the assessment and management of CD in children.
Doing Wrong Without Creating Harm
Authors: Darley John M. , Solan Lawrence M. , Kugler Matthew B. , Sanders Joseph
Published: February 2010

We investigate lay intuitions about the appropriate compensatory and retributive consequences of a wrongdoer putting another in harm's way when harm either does or does not result. Compensation tracked whether the harm actually occurred, though when harm has not yet occurred but might, participants prefer an escrow‐like solution in which money will be available to the victim only if the risk matures into actual harm. Retributive sanctions (punitive damages, fines, prison terms) were largely unaffected by whether the harm materialized but were instead sensitive to whether the wrongdoer exhibited negligent or reckless conduct. Thus, subjects clearly differentiated between the retributive nature of punitive sanctions and the compensatory nature of restorative damages. Finally, subjects often assigned liability to the actor even when the risk‐causing actions were not negligent—and in this way preferred a strict liability stance more than does the current legal doctrine.
Measuring spin of a supermassive black hole at the Galactic centre — implications for a unique spin
Authors: Kato Y. , Miyoshi M. , Takahashi R. , Negoro H. , Matsumoto R.
Published: February 2010

We determine the spin of a supermassive black hole in the context of disc-seismology by comparing newly detected quasi-periodic oscillations (QPOs) of radio emission in the Galactic centre, Sagittarius A* (Sgr A*), as well as infrared and X-ray emissions with those of the Galactic black holes. We find that the spin parameters of black holes in Sgr A* and in Galactic X-ray sources have a unique value of ≈0.44 which is smaller than the generally accepted value for supermassive black holes, suggesting evidence for the angular momentum extraction of black holes during the growth of supermassive black holes. Our results demonstrate that the spin parameter approaches the equilibrium value where spin-up via accretion is balanced by spin-down via the Blandford–Znajek mechanism regardless of its initial spin. We anticipate that measuring the spin of black holes by using QPOs will open a new window for exploring the evolution of black holes in the Universe.
Penal Boundaries: Banishment and the Expansion of Punishment
Authors: Beckett Katherine , Herbert Steve
Published: February 2010

We use this article to argue for greater recognition of legally imposed spatial exclusion—banishment—as a (re)emerging and consequential social control practice. Although the new social control techniques that entail banishment are buttressed by a blend of civil, administrative, and criminal law, they are best understood as punitive in nature. This argument is supported by two empirical findings. First, interviews with the banished indicate that spatial exclusion often has significant negative consequences akin to those identified by Sykes (1958) in his seminal account of the pains of imprisonment. Second, court data show that the growing use of civil and administrative banishment has increased the number of criminal cases involving allegations of noncompliance. These findings suggest that analysts of punishment might usefully broaden their focus to include phenomena that combine civil, criminal, and legal authority, and are not defined as punishment by their advocates.
A New Method for Discharge State Prediction of Micro-EDM Using Empirical Mode Decomposition
Authors: Jia Zhenyuan , Zhang Lingxuan , Wang Fuji , Liu Wei
Published: February 2010

The property of high frequency in micro-EDM (electrical discharge machining) causes the discharge states to vary much faster than in conventional EDM, and discharge states of micro-EDM have the characteristics of nonstationarity, nonlinearity, and internal coupling, all of this makes it very difficult to carry out stable control. Thus empirical mode decomposition is adopted to conduct the prediction of the discharge states obtained through multisensor data fusion and fuzzy logic in micro-EDM. Combined with the autoregressive (AR) model identification and linear prediction, the mathematical model for EDM discharge state prediction using empirical mode decomposition is established and the corresponding prediction method is presented. Experiments demonstrate that the new prediction method with short identification data is highly accurate and operates quickly. Even using short model identification data, the accuracy of empirical mode decomposition prediction can stably reach a correlation of 74%, which satisfies statistical expectations. Additionally, the new process can also effectively eliminate the lag of conventional prediction methods to improve the efficiency of micro-EDM, and it provides a good basis to enhance the stability of the control system.
Computational Study of the Effect of Governing Parameters on a Polymer Injection Molding Process for Single-Cavity and Multicavity Mold Systems
Authors: Tutar M. , Karakus A.
Published: February 2010

In the present study a more complete numerical solution approach using parallel computing technology is provided for the three-dimensional modeling of mold insert polymer injection molding process by considering the effects of phase-change and compressibility for non-Newtonian fluid flow conditions. A volume of fluid (VOF) method coupled with a finite volume approach is used to simulate the mold-filling stage of the injection molding process. The variations in viscosity and density in the polymer melt flow are successfully resolved in the present VOF method to more accurately represent the rheological behavior of the polymer melt flow during the mold filling. A comprehensive high-resolution differencing scheme (compressive interface capturing scheme for arbitrary meshes or CICSAM) is successfully utilized to capture moving interfaces and the pressure-implicit with splitting operators pressure-velocity coupling algorithm is employed to enable a higher degree of approximate relation between corrections for pressure and velocity. The capabilities of the proposed numerical methodology in modeling real molding flow conditions are verified through quantitative and qualitative comparisons with other simulation programs and the data obtained from the experimental study conducted. The present numerical results are also compared with each other for a polypropylene female threaded adaptor pipe fitting model with a metallic insert for varying governing process conditions/parameters to assess the modeling constraints and enhancements of the present numerical procedure and the effects of these conditions to optimize the polymer melt flow for mold insert polymer injection molding process. The numerical results suggest that the present numerical solution approach can be used with a confidence for further studies of optimization of design of mold insert polymer injection molding processes.
Micromachining of Metals, Alloys, and Ceramics by Picosecond Laser Ablation
Authors: Hu Wenqian , Shin Yung C. , King Galen B.
Published: February 2010

Microhole drilling and microstructure machining with a picosecond (ps) Nd:YVO4 laser (pulse duration of 10 ps) in metals, alloys, and ceramics are reported. Blind and through microholes are drilled by percussion drilling as well as trepanning drilling, where the diameters of the holes are in the range of 20–1000 μm. Microfeatures are also machined and the flexibility of ps laser machining is demonstrated. The quality of drilled holes, e.g., recast layer, microcrack, and conicity, and that of the microstructures, are investigated by an optical microscope, a surface profilometer, or a scanning electron microscope. Ps laser ablation rate is studied by experiments and a simplified laser ablation model.
Waterjet and Water-Air Jet Surface Processing of a Titanium Alloy: A Parametric Evaluation
Authors: Chillman Alex , Ramulu M. , Hashish M.
Published: February 2010

High-pressure waterjets have emerged as a viable method for surface texturing, cleaning, and peening of metallic materials. As the material advancements continue, research into alternate surface processing methods must strive to keep pace. One material in particular that has experienced an increase in use in the biomedical and aerospace industries is titanium—due largely to its high strength to weight ratio and corrosion resistance. In this paper, surface preparation of a titanium alloy using waterjet and the water-air jet nozzles at pressures up to 600 MPa was evaluated. A parametric study was performed based on the supply pressure, standoff distance, traverse rate, and applied air flow rate. An analysis of variance was performed on the resulting experimental set to identify the key parameters contributing to the material erosion rates and resulting surface roughness parameters. The supply pressure was found to be the primary contributor to the erosive characteristics of the waterjet followed by the traverse rate. These parameters together govern the total energy per unit area transferred to the workpiece.
Droplet Behavior on a Rotating Surface for Atomization-Based Cutting Fluid Application in Micromachining
Authors: Ghai Isha , Wentz John , DeVor Richard E. , Kapoor Shiv G. , Samuel Johnson
Published: February 2010

The droplet behavior on a rotating surface has been studied to better understand the physics underlying atomized cutting fluid application. To this end, microturning experiments are carried out and the cutting performance evaluated for varying cutting fluids and at different droplet speeds. Microturning experiments indicate that a cutting fluid with low surface tension and low viscosity generates lower cutting temperatures, whereas a fluid with low surface tension and high viscosity generates lower cutting forces. Single-droplet impingement experiments are also conducted on a rotating surface using fluids with different surface tension and viscosity values. Upon impact, the droplet shape is observed to be a function of both the droplet speed and the surface speed. The spreading increases with increased surface speed owing to the tangential momentum added by the rotating surface. Spreading is observed to also increase with a decrease in fluid surface tension and does not change with the fluid viscosity. The evaporation rate is observed to increase for a rotating surface owing to convective heat transfer. Low surface tension and low viscosity are observed to increase the evaporation rate. It is concluded that a fluid with low surface tension and low viscosity is an effective coolant of the cutting zone, whereas a fluid with low surface tension and high viscosity is effective for lubrication.
Melt Pool Temperature Control for Laser Metal Deposition Processes—Part II: Layer-to-Layer Temperature Control
Authors: Tang Lie , Landers Robert G.
Published: February 2010

Heat input regulation is crucial for deposition quality in laser metal deposition (LMD) processes. To control the heat input, melt pool temperature is regulated using temperature controllers. Part I of this paper showed that, although online melt pool temperature control performs well in terms of tracking the temperature reference, it cannot guarantee consistent track morphology. Therefore, a new methodology, known as layer-to-layer temperature control, is proposed in this paper. The idea of layer-to-layer temperature control is to adjust the laser power profile between layers. The part height profile is measured between layers, and the temperature is measured online. The data are then utilized to identify the parameters of a LMD process model using particle swarm optimization. The laser power profile is then computed using iterative learning control, based on the estimated process model and the reference melt pool temperature of the next layer. The deposition results show that the layer-to-layer temperature controller is capable of not only tracking the reference temperature, but also producing a consistent track morphology.
Local Thinning at a Die Entry Radius During Hot Gas-Pressure Forming of an AA5083 Sheet
Authors: Taleff Eric M. , Hector Louis G. , Bradley John R. , Verma Ravi , Krajewski Paul E.
Published: February 2010

Splitting at regions of local thinning below die entry radii is a critically important mechanism of failure in hot gas-pressure forming of sheet materials. Local thinning is controlled by sheet-die friction and die geometry, as well as sheet material properties. In this study, local thinning is investigated at a particularly severe die entry radius during hot forming of a fine-grained AA5083 sheet at 450°C. Particular emphasis is placed on the relationship between local thinning and sheet-die friction conditions. A simple analysis of the mechanics of this thinning phenomenon is presented. Finite element simulation results are presented for different sheet-die friction conditions. Sheet thickness profiles measured from parts produced in forming experiments using three different lubrication conditions are compared with predictions from simulations. Simulation predictions agree well with experimental data for the occurrence and location of thinning below a die entry radius. Additional insights into sheet-die friction for controlling local thinning and preventing premature necking failure are detailed.
Study on Spinning Process of a Thin-Walled Aluminum Alloy Vessel Head With Small Ratio of Thickness to Diameter
Authors: Zhang Yanqiu , Shan Debin , Xu Wenchen , Lv Yan
Published: February 2010

The thin-walled vessel head with the ratio of thickness to diameter less than 3‰ has long been considered to be difficult to be spun because wrinkling is very likely to occur during the thin-walled vessel head spinning process when the thickness is far smaller than the diameter. Based on process experiments and finite element method, the spinning failure of thin-walled vessel head with a small ratio of thickness to diameter is analyzed in the present research. The mechanism of wrinkling is identified and some effective solutions are discussed to prevent the failure. The results show that the feed ratio, the blank geometry, and the roller trajectory are the main factors influencing the spinning qualities. In the shear spinning, the feasible roller feed ratio is found to be within a very small range because of the thin thickness of blanks. Wrinkling will occur if the feed ratio is slightly outside the operation range. Bending the edge of blank or enlarging the blank size can effectively prevent wrinkling at a larger feed ratio, which would increase the operation range of roller feed ratio. Due to the fact that the conventional spinning is a process of multiple passes, there are many factors affecting the forming quality of thin-walled aluminum alloy vessel head. Wrinkling is likely to happen by the influence of roller trajectory in the first pass due to the fact that the thickness of blank is far smaller than the diameter. The straight-line trajectory is the worst trajectory under which wrinkling is most likely to occur.
New Models and Global Stability Charts to Avoid Principal Instabilities and Constraints in Throughfeed Centerless Grinding
Authors: Barrenetxea D. , Álvarez J. , Marquínez J. I. , Madariaga J. , Gallego I. , Perelló I. Muguerza
Published: February 2010

This paper presents new simulation models and global stability charts that have been developed to analyze the principal instabilities and constraints involved in the throughfeed centerless grinding process. In addition to a frequency domain stability analysis of the three characteristic instabilities of the process (geometric lobing, chatter and spinning), new models have been developed and implemented to analyze the other main restrictions, namely, process power, temperature and burning power, roughness, and final part geometrical tolerance due to machine compliance. As a result, new global stability charts have been devised where instabilities are plotted against different productivity rates by combining the two principal variables in the throughfeed process: regulating wheel speed and feed angle. The use of such charts has led to the development of new optimization strategies for throughfeed operation mode and their implementation in a web based SET-UP ASSISTANT software tool developed to improve machining accuracy and productivity in centerless grinding.
Adaptive Control of Pressure Tracking for Polishing Process
Authors: Liao Liang , Xi Fengfeng Jeff , Liu Kefu
Published: February 2010

In this paper, an adaptive controller is developed for the pressure tracking of the pressurized toolhead in order to maintain the constant contact stress for the polishing process. This is a new polishing control method, which combines the adaptive control theory and the constant stress theory of the contact model. By using an active pneumatic compliant toolhead, a recursive least-squares estimator is developed to estimate the pneumatic model, and then a minimum-degree pole-placement method is applied to design a self-tuning controller. The simulation and experiment results of the proposed controller are presented and discussed. The main advantage of the constant contact stress control is high figuring accuracy.