bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of Resistivity Sounding in the Exploration for Nigerian Tarsand
Authors: Ako B. D. , Alabi A. O. , Adegoke O. S. , Enu E. I.
Published: July 2017

The extensive tarsand deposits of Ondo and Ogun States of Nigeria have previously been investigated only by the use of geological methods. In a recently completed exploration programme covering a 17 km2 area north of Agbabu, in the Ifesowapo Local Government area of Ondo State, the electrical resistivity technique was used extensively along with other exploration methods. The electrical resistivity survey was made up of 32 Schlumberger vertical electrical soundings (VES). The resistivity curves were interpreted by curve matching and computer based automatic interpretation techniques. Apparent resistivity values obtained varied between less than 10 ohm-m to greater than 1000 ohm-m. The results permitted fair to excellent correlation between the geoelectrical and Stratigraphic data, particularly the delineation of lithological boundaries and zone of bitumen saturation. The lithological boundaries and zone of bitumen saturation. The geophysical results also confirmed the regional block faulting and the consistent, increase in overburden thickness southwards.
Petroleum Potential of the Siberian Platform and its Exploitation Prospects
Authors: Kontorovich A.E. , Melnikov N.V. , Surkov V.S. , Trofimuk A.A.
Published: July 2017

A detailed technical appraisal is made of the Siberian Platform of the USSR.
The Ninian Pipeline System in the UK North Sea – Developments for the Second Generation of Fields
Authors: Lindop Paul H
Published: July 2017

As the original giant fields of the East Shetland Basin enter their decline period there has been, as with any mature asset, the challenge of managing the pipeline system's potential and cost per barrel. One way to maintain this potential is to keep the system full by bringing other parties' volumes in to take the growing ullage. The Ninian Field, Ninian Pipeline System and Sullom Voe Terminal are, amongst other measures, benefitting from the advances of technology which have moved undeveloped fields from the marginal to the economic, and hence opened up a new generation of fields to use the pipeline system and enhance its value. At the same time as this, rationalisation of the process facilities at Sullom Voe, Europe's largest oil and liquified gas terminal, has as its aim to maintain the terminals efficiency and economic viability.
Changes in World Gas Reserves and Resources
Authors: Cornot-Gandolphe Sylvie
Published: July 2017

The availability of natural gas world wide is reviewed including a detailed analysis of offshore reserves. Gas reserves are increasing year by year and commentary is provided on the new discoveries during 1993. Estimates of ultimate resources are provided together with an analysis of key factors affecting the reserves/resources interface.
Worldwide Criteria Versus Regional Criteria
Authors: De Menezes Fernando Ramos
Published: July 2017

Reserve calculation must be performed according to the intended use of this information. It can be considered for the purpose of (1) defining a production strategy or (2) for computing the assets of a company.

When production strategy is the major concern, the amounts and classification of hydrocarbon reserves are to be related to the development policy of a company, and a detailed reporting of these reserves must be required.

Otherwise, if the goal is to compute the assets for the purpose of comparison or loan security, it becomes necessary to follow a common procedure that will lead to universal comprehension and confidence. This standardized process may be insufficient to meet the needs of a development program from a technical standpoint.

Concluding, in spite of a company feeling the necessity of subdividing its reserves into a detailed form to achieve the best planning of production, that same company cannot deny the importance of reporting these into a single and comprehensive classification to meet the requirements of the world.

The paper describes the detailed classification used at Petrobrás to estimate the risk involved in the development program of the Brazilian fields, and how this classification can be adjusted to provide a universal appraisal of the reserves.
Geographic and Industrial Corporate Diversification: The Level and Structure of Executive Compensation
Authors: Duru Augustine , Reeb David M.
Published: July 2017

We explore the relation between corporate diversification and CEO compensation. We document that geographic diversification provides a compensation premium, while industrial diversification is associated with lower levels of CEO pay. We also examine the effect of corporate diversification on the structure and performance criteria of CEO compensation contracts. We find that both diversification strategies are associated with a greater use of incentive-based compensation and with a greater reliance on market-based, rather than accounting-based measures of firm performance. Finally, we address the question of whether shareholders reward CEOs for corporate diversification. We document that while value-enhancing geographic diversification is rewarded, non-value-enhancing industrial diversification is penalized.
Audit Quality, Management Ownership, and the Informativeness of Accounting Earnings
Authors: Gul Ferdinand A. , Lynn Stephen G. , Tsui Judy S. L.
Published: July 2017

This study has two primary objectives. First, it examines whether audit quality moderates the association between informativeness of accounting earnings and management ownership. Second, it also examines whether audit quality moderates the negative association between management ownership and discretionary accruals. Using Australian data, it is shown that the positive relationship between returns-earnings association and management ownership is signijicantly weaker for firms with Big 6 auditors. Similarly, the negative association between management ownership and discretionary accruals is weaker for firms with Big 6 auditors. These results are consistent with the theory that higher quality audits can mitigate insiders' incentives to exploit accounting-based contractual constraints and manage earnings as a result of the separation of ownership and control.
The Large Audit Firm Fee Premium: A Case of Selectivity Bias?
Authors: Ireland Jen C. , Lennox Clive S.
Published: July 2017

Audit fee studies often find large (Big 5) audit firms earn significantly higher fees than small (non-Big 5) firms, but they treat auditor choice as exogenous. In contrast, this paper takes into account that companies are not randomly assigned to audit firms. We find the effects of auditor selection bias on audit fees are statistically and economically significant. Consistent with the predictions of analytical research, our results suggest large (small) audit firms experience advantageous (adverse) selection in attracting high (low) quality companies. Our results indicate the premium earned by large audit firms is more than twice as large when selectivity effects are taken into account (53.4% compared to 19.2%).
Differential Pricing of Components of Bank Loan Fair Values
Authors: Beaver William , Venkatachalam Mohan
Published: July 2017

This paper examines the capital market pricing implications of nondiscretionary, discretionary, and noise components of loan fair values for a sample of commercial banks. We use a model to partition loan fair values into discretionary and nondiscretionary components using proxies for discretion and nondiscretion. The residual from the model captures the noise component. We hypothesize that the nondiscretionary component is priced on a dollar-for-dollar basis and the residual (noise) component is not priced. The pricing coefficient on the discretionary component is predicted to be positive (negative) depending on whether the motivation for discretion is signaling (opportunism). We find evidence consistent with the hypotheses, implying that the relevance and reliability of loan fair values differs across the three components.
Reactions to Dividend Changes Conditional on Earnings Quality
Authors: Mikhail Michael B. , Walther Beverly R. , Willis Richard H.
Published: July 2017

We investigate if market participants' reactions to dividend changes are related to “earnings quality,” defined as the extent to which a firm's past earnings are associated with its future cash flows. Consistent with predictions from analytical work (Holthausen and Verrecchia [1988]; Kim and Verrecchia [1991]), we find that, controlling for the firm's dividend change, information environment, investment opportunity set, operating risk, and dividend clienteles, the market reacts less to dividend increase announcements from firms with greater earnings quality. Controlling for the firm's dividend change, information environment, and the release of other information around the dividend declaration date, we also document that analyst forecast revisions are significantly lower for firms with higher earnings quality following dividend increases. In both the market reaction and analyst forecast revision tests, our results for dividend decreases are generally not statistically significant.
Historical Accounting and the Endogenous Credibility of Current Disclosures
Authors: Lundholm Russell J.
Published: July 2017

This paper examines how historical financial reporting can serve as an ex post check on more timely voluntary disclosures, and shows that such a check can be sufficient to ensure that the voluntary disclosures are credible most of the time. The model describes an adverse selection setting where an informed seller communicates with an uninformed buyer over time, but there is no exogenous means of making the seller's communication credible. The addition of an ex post report enables the buyer to assess the accuracy of the seller's prior communications and gives the buyer a means to punish a seller who has disclosed falsely in the past. Under certain conditions, this threat of punishment keeps the seller honest in the present most of the time. The model provides a formal means of evaluating the Lundholm (1999) proposal that accounting regulation should turn its attention to supporting credible voluntary disclosures by reporting on the accuracy of past estimates.
Short-Term Contracts, Long-Term Actions, and Information System Design
Authors: Balakrishnan Ramji , Sivaramakrishnan K. , Surysekar K.
Published: July 2017

We examine how “long-term actions” (current period actions that bear fruit in the future) can be motivated when short-term contracts are employed, and derive implications for the design of performance measurement systems. In our two-period model with unknown agent type and moral hazard, the principal chooses between a fine and a coarse performance measurement system. These two systems differ in the information they convey about the agent's unknown type and therefore lead to different retention/firing policies. The principal's retention policy in turn influences the agent's incentives to undertake long-term actions, especially if the agent has advance information about what the performance is likely to be; an employee expecting to get fired is less likely to take actions that will bear fruit only after his departure from the firm. We show that the principal may prefer a coarser performance measurement system because it can substitute for her ability to commit to retention decisions. We also show that the finer the agent's private information is, the greater the benefit for the principal from coarsening the performance measurement system for contracting purposes. We discuss some practical implications of our analysis.
The Auditor-to-Client Revolving Door and Earnings Management
Authors: Geiger Marshall A. , North David S. , O'Connell Brendan T.
Published: July 2017

The recent passing of the Sarbanes-Oxley Act of 2002 resulted in restrictions being placed on the so-called “revolving door,” where a company hires a senior financial reporting executive directly from its external audit firm. This legislative action, despite a lack of empirical research into the practice, reflects concerns about possible impairment of auditor independence through the hiring of personnel from the company's external auditor. Our study examines a sample of firms where financial reporting executives such as the CFO, VP-Finance, or Controller were hired by a public company directly from their external audit firm. Our results indicate that earnings management, in the form of increased accounting accruals, is no greater immediately before or after hiring in the companies engaging in this hiring practice compared to three separate control groups hiring individuals from other sources or retaining their incumbent financial reporting executives. We also find that changes in accruals surrounding the hiring of these former auditors is relatively stable over the 11-year period studied. Overall, our results with respect to changes in levels of reported accounting accruals generally do not support regulators' concerns of significantly impaired auditor independence in these hiring situations.
Harmonization, Comparability, and Fair Value Accounting
Authors: Barlev Benzion , Haddad Joshua Rene
Published: July 2017

In this paper, we focus on the relationships between international accounting harmonization (IAH) and the paradigm of Fair Value Accounting (FVA). Accountants rely on the accounting concept of comparability in defining IAH and are in agreement that a set of internationally implemented Generally Accepted Accounting Principles (GAAP) is required for a “complete harmonization.” We argue, however, that a second requirement—a common denominator for measuring, recording, and reporting business transactions, assets, liabilities, and equities—is necessary to reach a state of a “complete IAH.” We explain the logic behind the requirement of a common denominator and assert that IAH is feasible under the paradigm of FVA, but not under that of Historical Cost Accounting (HCA). This is true because the concept of fair value, but not historical cost, provides the common denominator necessary for a meaningful comparison of accounting data. We then argue that the paradigm of FVA acts as a catalyst in a harmonization cycle: FVA propels IAH and IAH provides more relevant information that may foster the efficiency of global markets, which improves the quality of the FVA figures.
Auditor Fees and Cost of Debt
Authors: Dhaliwal Dan S. , Gleason Cristi A. , Heitzman Shane , Melendrez Kevin D.
Published: July 2017

Using a sample of 560 new debt issues, we investigate the relation between audit, nonaudit, and total auditor fees and firms' cost of debt. The Securities and Exchange Commission (SEC) argues that fees from nonaudit services weaken auditor independence, reduce financial statement reliability, and increase firms' cost of capital. To test this assertion, we examine the association between auditor fees and the cost of debt, as well as the effects of auditor fees on the relation between financial statement information and the cost of debt. We find evidence that nonaudit fees are directly related to the cost of debt for investment-grade issuers. Our results are robust to controlling for auditor tenure and firm governance. We also find evidence that the association between earnings and the cost of debt decreases as audit fees increase. We find no evidence that auditor fees directly affect the cost of debt for the non-investment-grade firms, but we do find that the association between earnings and the cost of debt decreases as nonaudit fees increase.
The Economic Consequence of Voluntary Auditing
Authors: Haw In-Mu , Qi Daqing , Wu Woody
Published: July 2017

A number of Chinese firms voluntarily acquire auditing services for their interim reports, even though the auditing of interim reports is mandatory only for a subset of firms in circumstances that are specified by the state regulators. This unique institutional setting in the Chinese market provides a natural experimental setting to directly investigate why listed firms voluntarily have their financial reports audited, and whether investors place more value on voluntarily audited earnings than on unaudited earnings. Based on a sample of 2,458 semi-annual interim reports released by listed Chinese firms from 1996 to 1999, we find that the choice of voluntary auditing is positively associated with the percentage of tradable shares, profitability, and company size. We also find that the earnings response coefficients of audited firms are higher than those of unaudited firms, especially when the auditing is voluntary. Our findings are consistent with theoretical propositions that managers voluntarily purchase external auditing to enhance the credibility of accounting numbers. This study contributes to the literature, especially on the economic value of voluntary auditing.
An Examination of the Effects of Investor Sophistication on the Pricing of Accruals and Cash Flows
Authors: Barone Gerhard J. , Magilke Matthew J.
Published: July 2017

We examine the role of sophisticated investors in the pricing of both accruals and cash flows (i.e., the naive-investor hypothesis). Unlike prior research, however, we analyze the returns to three specific trading strategies: 1) returns that are specific to a cash-flows trading strategy; 2) returns that are specific to an accruals trading strategy; and 3) returns that are common to both an accruals and a cash-flows trading strategy. We find evidence consistent with predictions of the naive-investor hypothesis with respect to cash flow mispricing. That is, for returns that are specific to a cash-flows trading strategy, we find that relative to naive investors, sophisticated investors are associated with a significant reduction in the mispricing of cash flows. Consistent with Desai et al. (2004), we find no evidence of mispricing related to accruals. That is, for returns that are specific to an accruals trading strategy, we find no evidence of mispricing for either naive or sophisticated investors. Finally, with respect to returns that are common to both the accruals and cash-flows trading strategies, we find evidence consistent with predictions of the naive-investor hypothesis. That is, significant mispricing exists for naive investors, while sophisticated investors are associated with a significant reduction in this mispricing. In general, our results highlight the importance of considering the common returns to hedge trading strategies when examining the effects of external factors on the pricing of accruals and cash flows.
Internal Control Weaknesses and Client Risk Management
Authors: Elder Randal , Zhang Yan , Zhou Jian , Zhou Nan
Published: July 2017

We study auditors' client risk management in the first year of the Sarbanes-Act Oxley (SOX) 404 implementation, and find that a pecking order exists among auditors' strategies to manage control risk resulting from internal control weaknesses. We first examine the relation between internal control weaknesses and audit fees, modified opinions, and auditor resignations, respectively, and establish that these are viable strategies to manage control risk on a stand-alone basis. We also find that changes in audit fees and changes in modified opinions are positively associated with changes in reported internal control weaknesses. When we investigate these strategies simultaneously, descriptive evidence suggests that a pecking order exists among auditors' client risk management strategies. Ordered logit analyses further confirm that, as clients' control risk increases, auditors are likely to respond in the order of audit fee adjustments, modified opinions, and auditor resignations. Our comprehensive evidence suggests that auditors use an array of ordered strategies to manage client-related control risk.
Discussion of “Regulatory Incentives for Earnings Management through Asset Impairment Reversals in China”
Authors: Riedl Edward J.
Published: July 2017

Shimin Chen, Yuetang Wang, and Ziye Zhao (2009) examine motivations for managers of Chinese-listed firms to report asset impairment reversals. The study documents that the reporting of such reversals reflects incentives to avoid delisting from Chinese stock exchanges and that stronger monitoring mechanisms attenuate this opportunistic reporting. The study exploits a unique feature of financial reporting within China, which allows large sample investigation of impairment reversals. I discuss the study's strengths, note some limitations on the analyses and inferences, and suggest recommendations for future research.
Warranted Multiples and Future Returns
Authors: An Jiyoun , Bhojraj Sanjeev , Ng David T.
Published: July 2017

We propose an alternative way of using accounting multiples to predict future returns. We define excess multiple as the difference between an accounting multiple and the warranted multiple based on a firm's fundamental value drivers. Firms with low excess multiples have higher one-to-three years ahead stock returns than firms that have high excess multiples. This difference in returns is economically and statistically significant and cannot be explained by Fama-French three factors or a momentum factor.
Layoffs and Chief Executive Officer (CEO) Compensation: Does CEO Power Influence the Relationship?
Authors: Henderson B. Charlene , Masli Adi , Richardson Vernon J. , Sanchez Juan Manuel
Published: July 2017

We examine the association between layoffs and chief executive officer (CEO) compensation. Because of the public scrutiny and political pressures associated with both CEO compensation and layoffs, we expect firms to alter CEO compensation by reducing bonus pay and increasing equity-based compensation as the magnitude of the layoff increases. Consistent with the predicted substitution, we find that as layoffs intensify, CEOs' bonus compensation decreases and their equity-based compensation increases. When we consider whether these compensation adjustments vary with CEO power, we find that as the layoff magnitude increases, relative to less powerful CEOs, more powerful CEOs experience smaller reductions in bonus pay, a higher likelihood of receiving a bonus, and comparable increases in equity compensation. Finally, we report evidence that post-layoff market performance of firms led by more powerful CEOs is not superior to that of firms led by less powerful CEOs. Collectively, the results suggest that the preferential compensation arrangements afforded more powerful CEOs is inconsistent with efficient contracting. Instead, the combined results are consistent with the managerial power theory.
Distributions of Audit-Detected Errors Partitioned by Internal Control
Authors: Icerman Rhoda C. , Hillison William A.
Published: July 2017

This research reports on the properties of audit-detected errors in accounting populations, including the relationship of those errors with levels of internal control, and whether the errors were booked or waived. As expected, the average number of errors was greater in weak internal control systems than in strong systems. In general, larger errors were discovered in accounts with larger balances and, as such, the size of the error was positively correlated with the size of the company. When the error was scaled by a company-specific deflator, the size of the relative error decreased with increased size of the company. This finding is consistent with the observation that larger companies tend to have stronger control systems. Comparison of the error distributions between weak and strong internal control systems exhibited significant differences. Further, the larger the relative error, the more likely it was booked. In general, the results provide preliminary empirical support for many of the previously unsupported assumptions on the relation of internal controls and accounting errors and irregularities.
Market Reactions to the Information Content of Earnings over Alternative Quarters
Authors: Jones Charles P. , Bublitz Bruce
Published: July 2017

This paper addresses issues left unanswered from prior published research showing that fourth-quarter earnings exhibit higher forecast errors. It offers an explanation for these findings and presents evidence to support this explanation. Unlike prior research, the market's reaction to fourth-quarter earnings as compared to that of the other three quarters is documented using a metric designed to capture both the size and sign of the forecast error.

Our analysis indicates that there is a differential market reaction to earnings surprises over alternative quarters. Large negative unexpected earnings in the fourth quarter are associated with a smaller negative adjustment in stock returns as compared to all other quarters. Such an adjustment agrees with the explanation developed here for the higher forecast errors in the fourth quarter. These results do not support previous research that found counter-intuitive results concerning the relationship between earnings surprises and stock market returns for the fourth quarter.
Accounting for Options, Forwards and Futures Contracts
Authors: Boze Ken M.
Published: July 2017

This paper discusses accounting for options, forward contracts, futures contracts, and other related securities used for hedges. An examination of the accounting and finance literature, authoritative pronouncements, and accounting theories leads to the conclusion that the accounting treatment of hedges does not reflect economic reality. A theoretical framework for accounting for all hedge activities, regardless of the techniques or contracts used to hedge, is presented. The paper concludes that the Financial Accounting Standards Board should not continue its incrementalism approach for establishing accounting standards for options, forwards and futures contracts. Instead, existing GAAP should be codified into one comprehensive statement on hedge accounting.
A Research Note on the Relationship between Regulation and Audit Firm Size on Audit Fees
Authors: Gist Willie E.
Published: July 2017

This study represents an initial attempt to examine some specific factors that might lead to large firms' economies of scale. Multiple regression analysis is used to test hypotheses concerning scale opportunities conferred on large CPA firms in dealing with regulatory complexity faced by the client. An analysis of interaction between audit firm size and variables measuring client regulatory complexity shows that audit fees are lower for all firms in regulated industries compared to nonregulated industries—the difference being much greater, however, for Big Eight (now Big Six) firms, and audit fees charged by Big Eight firms are much lower when the auditor is involved with client security registrations. This relationship does not hold true for non-Big Eight firms involved with client registration statements. Based on these results, it appears that client regulatory complexity confers greater scale opportunities to larger audit firms compared to smaller ones.
Firms' Choice of Estimation Parameters: Empirical Evidence from SFAS No. 106
Authors: Amir Eli , Gordon Elizabeth A.
Published: July 2017

This study explains the cross-sectional variation in firms' selected assumptions (discount rates and health care cost trend rates) used to measure the obligation for postretirement benefits other than pensions (PRB) under SFAS No. 106. Our aim is to examine whether managements manage the reported PRB by choosing either too conservative or too aggressive estimation parameters. In addition, we examine whether investors value the firm's equity based on the cross-section median parameters or based on each firm's selected parameters. We find that firms with relatively larger PRB obligation and more leverage tend to select more aggressive (obligation-reducing) estimation parameters. We also find that firms that amended their PRB plans and firms with extreme earnings-price ratios tend to select more conservative (obligation-increasing) estimation parameters. Finally, we find that investors value the firm's equity using reported rather than adjusted estimation parameters.
Considering Multiple Materialities for Account Combinations in Audit Planning and Evaluation: A Cost Efficient Approach
Authors: Dutta Saurav K. , Graham Lynford E.
Published: July 2017

An analytic framework is provided for incorporating different user perspectives on materiality into the audit process. The framework serves as a tool for disaggregating materiality to specific accounts based on materiality criteria for accounts and account combinations. To improve audit efficiency, the planning method incorporates the relative cost of auditing various account balances. It extends existing models of audit risk and materiality by considering explicitly the materiality of account combinations (sums and ratios) to enhance audit effectiveness.
Discussion: “Who Uses Interest Rate Swaps? a Cross-Sectional Analysis”
Authors: Schrand Catherine M.
Published: July 2017

In recent years, there have been numerous empirical studies of derivatives use because of new data availability that resulted from requirements for annual report disclosures about derivatives activities of nonfinancial firms ( Financial Accounting Standards Board Statements Nos. 105 and 119). Many of these studies test predictions from models of optimal hedging. These models suggest that the use of derivatives to reduce volatility in cash flows is optimal, even though it is costly, when the firm faces even greater exogenous or endogenous costs associated with cash flow volatility. Each of the models assumes the existence of a capital market imperfection that makes cash flow volatility costly. A common approach to testing these models is to examine the cross-sectional variation in the characteristics of firms that use derivatives (or use more derivatives). The explanatory variables represent firm characteristics that the author predicts are related to the proposed costs of volatility that the firm can reduce by hedging.
Discussion: “An Analysis of the Usefulness of Debt Defaults and Going Concern Opinions in Bankruptcy Risk Assessment”
Authors: Altman Edward I.
Published: July 2017

“Much Ado About Nothing?” Not quite, but one wonders where the real contribution is in this paper; indeed, in the several articles that have been written on the paper's central premise. The central premise is that the occurrence of a loan default or loan accommodation adds significantly to the ability of a model to accurately explain and predict bankruptcy. A minor theme involves the examination of whether an auditor's going concern qualification, with or without the already observed loan default/accommodation, adds to our ability to predict bankruptcy.
Accounting Disclosures and Corporate Payout Policy: Special Dividends versus Stock Repurchases
Authors: Gelb David
Published: July 2017

This study examines whether the choice of stock repurchases versus special dividends for one-time cash distributions is related to the level of a firm's accounting disclosures. The results indicate that firms providing more informative accounting disclosures are more likely to announce stock repurchase programs as a means for one-time cash distributions. In contrast, firms that provide less informative accounting disclosures tend to rely on special dividends for one-time cash distributions. These findings are consistent with prior studies that argue that information costs associated with stock repurchases limit their use as a payout method.
Daily Dressing Change Effects on Skin Flora Beneath Subclavian Catheter Dressings During Total Parenteral Nutrition
Authors: Jarrard Marilyn M. , Olson Charles M. , Freeman Joel B.
Published: July 2017

Septicemia is a persistent problem during total parenteral nutrition (TPN). The skin around the catheter insertion site is one possible source of this infection. In previous studies we showed mechanical cleansing of the skin was more important than the ointment applied; however, alternate day dressing changes did not completely eradicate all skin organisms. The present study was designed to examine the effects of daily dressing changes on the skin flora beneath the subclavian dressing. Fifteen patients receiving TPN were studied for a minimum of 11 days each. The dressing was changed daily and the catheter site cultured immediately. The area was then scrubbed with polyvinylpovidine‐iodine, an antibiotic ointment was placed on the catheter insertion site, and a new dressing applied. There were no positive skin or blood cultures in this group during a total study period of 242 patient‐days. The control group consisted of 23 patients receiving identical subclavian catheter care but on an alternate rather than daily basis. In the control group there was a 3.5% incidence of positive skin cultures in 530 patient‐days. Daily dressing changes eliminated all skin organisms beneath the subclavian dressing during TPN and would be useful in patients who are at high risk for septic complications.
Effect of Abrupt Discontinuation of High Glucose Infusion Rates During Parenteral Nutrition SL WERLIN, D WYATT, AND B CAMITTA J Pediatr 124:441–444, 1994
Authors: Christensen Michael L.
Published: July 2017

Serum glucose and insulin concentrations were measured in 15 children older than 2 years of age for 30 minutes after abrupt discontinuation of total parenteral nutrition (TPN). The children ranged in age from 2.4 to 14.2 years (mean 7.9 years). These infants were receiving <10% of their caloric intake by the enteral route. Four patients were receiving corticosteroids. The glucose concentration in the TPN solutions at the time of discontinuation was 15% to 20%. The glucose infusion rate was 0.53 ± 0.23 mmol/kg/min (range 0.22 to 1.2) (9.6 ± 4.2 mg/kg/min; range 4 to 21). Paired glucose and insulin concentrations were measured before, 15, and 30 minutes after the TPN was abruptly discontinued. One child was considered an outlier because of insulin concentrations that were approximately 10‐fold higher than the other children and was not included in the analysis. The initial insulin levels were elevated and rapidly became normal. Glucose concentrations were slightly elevated at the time parenteral nutrition was stopped but were normal and remained stable after 15 minutes. Only one child had a glucose concentration decrease to <3.3 mmol/L (60 mg/dL), and no child had symptomatic hypoglycemia. The investigators found no influence of glucose infusion rate, age, or use of corticosteroid on glucose or insulin concentrations.
The Utility of Impulse Response Functions in Regional Analysis: Some Critical Issues
Authors: Cromwell Jeff B. , Hannan Michael J.
Published: July 2017

Regional scientists have long been interested in measuring the effects of various external and internal stimuli on a regional economy. Measuring the actual size and timing of exogenous and endogenous impacts has been of special interest, as numerical or estimation techniques allow regional actors (governments, business, and others) to make policy-type probability statements and actions in response to changes to these stimuli. Recently, the use of vector autoregressive (VAR) models and, consequently, impulse response functions has become increasingly popular. This paper will closely examine the VAR methodology and its assumptions and will address the types of empirical issues that arise from actual regional implementation. The issues of stationarity, model specification and selection, order determination, and impulse responses are discussed.
Mechanisms of the Volume Filling of Micropores during the Adsorption of Vapours
Authors: Kadlec O.
Published: July 2017

The fundamental equation for the pressure pal of the adsorbed phase is derived by the thermodynamic treatment of micropore volume filling (MVF) process which also takes into account the structural changes of the adsorbate in the field of adsorption forces. The introduction of the principle of hydro-dynamical and mechanical equilibria reveals that MVF mechanisms can be characterized and classified according to the values of the pressures pfal corresponding to the beginning of MVF. The values of these pressures are calculated on the basis of experimental measurements of the length changes of the adsorbent rods during vapour adsorption. It is concluded, that the validity of the potential theory for MVF is based on the equality of the pfal and the standard liquid state pol pressures (mechanism MVF 1). The existence of negative pressures pal is typical for the MVF 2 mechanism. The positive values of pfal are characteristic for the intrusion of liquids into the micropores of solids, not wetted by the liquid (mechanism MVF 3).
Effect of Calcination on the Structure and Texture of Gamma-Alumina Prepared by Thermolysis of Aluminium Sulphate
Authors: Arean C. Otero , Platero E. Escalona
Published: July 2017

Thermal decomposition of aluminium sulphate at 1173 K produces mesoporous γ-alumina with a BET surface area of 134 m2 g−1. This active alumina was subsequently calcined in air at temperatures ranging from 1173 to 1523 K. The microcrystalline structure, surface area and porous texture of the resulting materials were analysed by X-ray diffraction and nitrogen adsorption measurements. The results suggest that γ-alumina is converted into the α-modification in the sequence: γ-alumina → δ-alumina → θ-alumina → α-alumina. All oxides calcined within the temperature range 1173–1473 K were found to be mesoporous. The most frequent pore radius increased slowly, from 10.5 to 13.5 nm, as the temperature was raised from 1173 to 1423 K. However, calcination at 1473 K resulted in a sharp increase of pore radius (up to 18.5 nm) with simultaneous reduction of the BET surface area and total pore volume by over 75%. The sample fired at 1523 K showed a BET surface area smaller than 5 m2 g−1.
Hydrogen and Oxygen Chemisorptions and Titrations by Platinum on Zirconia Catalysts Reduced between 673 and 1273 K
Authors: Tournayan L. , Auroux A. , Charcosset H. , Szymanski R.
Published: July 2017

Some 10 wt % Pt supported on zirconia catalysts were investigated by hydrogen and oxygen chemisorptions and titrations by means of automated catharometric equipment (frontal method). Microcalorimetry was further used to determine the heats of oxygen chemisorption. The temperature of reduction by hydrogen, TR, was varied between 673 and 1273 K. At 673 K, the H and O coverages of Pt were about the same as for Pt supported on SiO2 (Euro Pt catalyst). The increase in TR from 673 to 873 K was accompanied by a strong decrease of the hydrogen to oxygen chemisorption ratio. It is proposed that this is due to Pt1– xZr x alloy formation, with small values of x (≤0·05). When TR was above 873 K, x determined by X-ray diffraction analysis increased up to 0·25. The hydrogen chemisorption is confined to Pt s, while the oxygen chemisorption takes place on Pt s and Zr sO x. The surface composition may be derived and is found twice as rich in Zr as the mean composition of the alloy particles.
A Study of the Micropore Structure of Carbonized Rayon Yarn by Nitrogen Adsorption and Nonane Pre-Adsorption
Authors: Bohra J. N. , Sing K. S. W.
Published: July 2017

Adsorption isotherms of nitrogen have been determined at 77 K on three samples of carbonized rayon yarn, both before and after the pre-adsorption of n-nonane. In their original state the three samples were all highly microporous. Application of the αs-method of isotherm analysis reveals that their micropore volumes were 0·17–0·19 cm3g−1 and their external surface areas 20–27 m2g−1 (the corresponding BET areas being 427–483 m2g−1). Nonane pre-adsorption resulted in blockage of the entire micropore structure only in the case of one sample: micropore volumes ∼0·1 cm3g−1 were still available for nitrogen adsorption in the other two samples. It appears that nitrogen molecules were able to gain access to some parts of these micropore structures through wider pore entrances which were not completely blocked by the pre-adsorbed nonane. The work has shown that the nonane pre-adsorption method requires further investigation before it can be used with confidence for the assessment of microporosity.
Adsorption of Water Vapour on Rutile and Silica-Coated Rutile
Authors: Furlong D. N. , Sing K. S. W. , Parfitt G. D.
Published: July 2017

Adsorption isotherms of water vapour have been determined at 25°C on pure rutile (surface area 22 m2.g−1) and on two samples of the rutile coated with different amounts of dense silica (0·6 & 2·6 wt% SiO2). With each adsorbent, the adsorption measurements were made after outgassing at temperatures of 298, 373, 423 and 573 K, and finally at 298 K in the case of the pure rutile. An upward displacement of the isotherms with an increase in the outgassing temperature was found with each system but a pronounced change in isotherm character was found only with pure rutile. It is concluded that ligand water is incorporated into the surface structure of rutile, thus providing additional sites for the physisorption of water in the hydrogen-bonded form. The addition of 0·6 wt% of silica appeared to be sufficient to block off the cationic sites and the resulting surface then became remarkably similar to that of precipitated silica.
Cyclic Adsorption of Styrene and of Plasticizer on BPL Carbon
Authors: Guo Don , Venkat Chandramouli , Weiss Alvin H.
Published: July 2017

The deactivation of BPL Carbon by styrene and by the plasticizer dimethyl phosphonate, which does not polymerize, was studied in cyclic adsorption-desorption. Breakthrough time for styrene at 323K over a 1 g bed was 225 min in the first cycle at 6900 mg/m3 inlet and 20 mg/m3 breakthrough concentrations. Breakthrough time fell to 140 min in the second cycle, to 101 min by the 40 th cycle. Desorption in vacuo was no more effective than atmospheric airflow at 423K. Similar results were had on plasticizer. Cyclic adsorber systems should be considered for inlet concentrations of these heavy materials above 1000 mg/m3. A non-cyclic adsorber is more economically effective below that concentration.
Comparison of Nitrogen Adsorption and Mercury Penetration Results. Pore Size Distributions for a Series of Mo-A12O3 Catalysis with Increasing MoO3 Content
Authors: Adkins Bruce D , Heink Jill B. , Davis Burtron H.
Published: July 2017

Scanning electron microscopic data, X-ray diffraction patterns and porosity measurements are consistent with a structure for an Mo-A12O3 catalyst series containing a single surface layer of Mo up to the point where the Mo loadings exceed the amount required for a monolayer. For greater Mo loadings than required for a monolayer, three dimensional orthorhombic MoO3 is also present. The cumulative pore volume, on an alumina basis, does not appear to be significantly altered by MoO3 loadings up to about 15 wt.%. The BET surface area, on an alumina basis, remains constant with Mo loading. However, the apparent surface area calculated from mercury penetration data decreases with Mo loading. For these materials with cylindrical pores, the Broekhoff-deBoer model for the calculation of pore size distributions produced closer agreement to the mercury penetration pore size distribution. This is in contrast to materials composed of nonporous spheres where the Broekhoff-deBoer model provided poorer agreement to mercury penetration results than either the Cohan or a packed sphere model. The results show that, within a factor of two the pore size distributions calculated from nitrogen adsorption and mercury penetration data are comparable.
The Effect of Reduction on the Adsorptive Behaviour of the TiO2/Water Interface
Authors: Antonucci V. , Arico' A.S. , Giordano N. , Antonucci P.L.
Published: July 2017

The effect of mild reduction treatment on TiO2 surfaces has been investigated by the ZPC (zero point of charge) potentiometric technique. Different extents of reduction result in a series of oxides distinguished either by their adsorption characteristics or electrochemical properties. Non-stoichiometric surface oxide formation has been demonstrated by X-ray diffraction and flat-band potential (Vfb) measurements. The generation of surface states with essentially acid–base characteristics has been shown to be a determining factor in the photo-oxidation–photodecomposition of water. A number of hypotheses relating to the nature of the adsorption-determining sites have been advanced.
Observations and Comments on the Displacement of Pre-Adsorbed Water from BPL Activated Carbon by Chloropicrin Vapour
Authors: Hall C. Richard , Holmes Richard J.
Published: July 2017

The breakthrough curves of chloropicrin vapour through beds of BPL activated carbon pre-equilibrated at different relative humidities (RH) have been measured. The associated water displacement curves and effluent temperature profiles are also presented. At first, as the experimental RH increases, the slope of the breakthrough curves gradually decreases. However, at high RH (i.e. 80%) the curve becomes distinctly biphasic. It is proposed that the initial steep part of the curve is the result of a build-up of water in the macro (transport) pore structure of the carbon which restricts access of chloropicrin to the micropores. The accumulation of water in the transport pores is a consequence of both the high carbon water content at RH 80% and the limitation on the amount of water that can be carried away in the air- stream (which rapidly reaches saturation). The shape of the water displacement curves is also influenced by re-adsorption of displaced water further along the filter bed. In most experiments there is a significant depression in the temperature of the effluent airstream. At RH 80% the overall process is notably endothermic.
Effect of Temperature on Neopentane Isotherms Determined on Non-Porous Non-Graphitized Carbon Black (Elftex)
Authors: Carrott P.J.M.
Published: July 2017

Adsorption isotherms of neopentane have been determined on the non-porous non-graphitized carbon black Elftex at temperatures from 282.8 K down to 249.0 K, i.e. from the boiling point of bulk neopentane to below its freezing point. It is shown that the shape of the isotherm in the multilayer region, and hence the magnitude of the FHH r value, is not directly affected be temperature, although an indirect effect, occurring as a result of a change in the properties of the adsorbed monolayer, is observed. It is also concluded that, if the properties of an adsorbed phase are dependent on coverage, then the adsorption isostere method is unlikely to lead to reliable values for the heat of adsorption.
X-Ray Computer Tomography: A Non-Destructive Method for Investigating Dynamic Sorption Processes on Activated Carbon
Authors: Wittwer A. , Lavanchy A.
Published: July 2017

The shape and propagation of the adsorption front of vapours and gases in activated carbon beds, e.g. within gas filters, can be visualised and analysed in a non-destructive way by X-ray computer tomography (Lottaz and Lavanchy 1987). A short description of the method is given and experimental results are presented which demonstrate the practical and successful use of this method in applications such as design improvements for gas filter canisters, based on the shape of the adsorption front, and the testing of numeric simulation and prediction models for dynamic sorption processes allowing the comparison of simulated ad- and de-sorption profiles of gravimetric load with experimental results.
Adsorption and Relative Permeability in a Two-Dimensional Bidisperse Anisotropic Pore Network Model
Authors: Schweighart Peter J. , Nicholson David
Published: July 2017

Adsorption isotherms and relative permeabilities have been calculated for a previously studied two-dimensional model for a bidisperse macroheterogeneous porous material containing regions of microporosity embedded in a mesoporous network. Both properties show distinctive features which reflect the underlying pore structure and which differ in several respects from similar results for macro-scopically homogeneous models.