1,589 research outputs found
Corporate social responsibility disclosures and earnings quality: Are they a reflection of managers’ opportunistic behavior?
Purpose – This paper aims to explore the relationship between corporate social responsibility (CSR) disclosures and earnings quality proxied by earnings accruals. Specifically, we examine whether CSR disclosures are context-specific, that is, whether companies dominated by powerful stakeholders are obliged to behave in a responsible manner to constrain earnings management, thereby reporting higher-quality earnings to investors. Design/methodology/approach – This paper explores the relationship between CSR disclosures and earnings quality proxied by earnings accruals. Specifically, we examine whether CSR disclosures are context-specific, that is, whether companies dominated by powerful stakeholders are obliged to behave in a responsible manner to constrain earnings management, thereby reporting higher-quality earnings to investors. Findings – Results show that managers in an emerging economy manage earnings when they provide more CSR disclosures. Such earnings management is achieved through income increasing discretionary accruals. Furthermore, companies from export-oriented industries dominated by powerful stakeholders (international buyers) disclosing more CSR activities, provide transparent financial reports through constraining earnings management. Originality/value – The findings of this study are significant for both investors and policymakers. Investors should not take for granted that firms engage in CSR activities, behave ethically and provide transparent financial reports. As we document that firms might manipulate earnings through discretionary accruals and provide less transparent financial reports to shareholders, the credibility of firms’ CSR policies should be assessed with caution. Policies directing at promoting socially responsible practices instead of motivating the desired behaviour, may provide managers with additional incentives to utilise CSR for opportunistic behaviour. Thus, policymakers need to be cautious about this opportunistic behaviour and enhance monitoring to enforce social compliance. Possibly, some guidelines can be introduced to confirm that CSR disclosures are based on actual practice and not just a “green wash” statement to deceive stakeholders
Conceptual Design of a Condensing Heat Exchanger for Space Systems Using Porous Media
Condensing heat exchangers are used in many space applications in the thermal and humidity control systems. In the International Space Station (ISS), humidity control is achieved by using a water cooled fin surface over which the moist air condenses, followed by "slurper bars" that take in both the condensate and air into a rotary separator and separates the water from air. The use of a cooled porous substrate as the condensing surface provides and attractive alternative that combines both heat removal as well as liquid/gas separation into a single unit. By selecting the pore sizes of the porous substrate a gravity independent operation may also be possible with this concept. Condensation of vapor into and on the porous surface from the flowing air and the removal of condensate from the porous substrate are the critical processes involved in the proposed concept. This paper describes some preliminary results of the proposed condensate withdrawal process and discusses the on-going design and development work of a porous media based condensing heat exchanger at the NASA Glenn Research Center in collaboration with NASA Johnson Space Center
Functional impact of remodeling during healing after non-Q wave versus Q wave anterior myocardial infarction in the dog
AbstractObjectives. This study was undertaken to compare changes in left ventricular remodeling and function during healing after a first anterior non-Q wave versus a Q wave myocardial infarction in the dog.Background. Whether ventricular remodeling is more severe after anterior Q wave than after anterior non-Q wave infarction has not been studied systematically.Methods. Serial remodeling and functional variables (two-dimensional echocardiography), electrocardiography and hemodynamic data were recorded over 6 weeks in 58 instrumented dogs subjected to left anterior descending coronary artery ligation or ligation plus collateral obliteration. Postmortem topography and transmurality (by planimetry) and infarct collagen (hydroxyproline) were measured at 6 weeks.Results. At 6 weeks, infarct collagen was similarly increased in both groups, but the Q wave group had greater infarct size (7.2% vs. 4.5%, p < 0.025) and greater transmurality (88% vs. 58%, p < 0.001), higher left atrial pressures, more infarct expansion (expansion index 2.62 vs. 2.31, p < 0.001), more thinning (thinning ratio 0.62 vs. 0.72, p < 0.001), greater cavity dilation (diastolic volume 88 vs. 72 ml, p < 0.001), more regional bulging in the short-axis view (depth 4.9 vs. 1.9 mm, p < 0.001), more regional asynergy (18% vs. 7%, p < 0.001), lower global ejection fraction (40% vs. 48%, p < 0.001), more endocardial and epicardial bulging in the long-axis view and greater incidence of aneurysm (82% vs. 36%, p < 0.005), left ventricular thrombus (64% vs. 0%, p < 0.0005) and ventricular arrhythmias. Echocardiograms obtained during a 6-week period indicated that left ventricular topographic deterioration and dysfunction were present in the earliest postinfarction study at 2 days in both groups but were more frequent in the Q wave group. Regional myocardial blood flow (24 dogs) was lower in the Q wave than in the non-Q wave group. Scanning electron microscopy (10 dogs) revealed preservation of the epicardial collagen matrix in the non-Q wave but not the Q wave group.Conclusions. Anterior Q wave infarction is associated with greater transmurality and more postinfarction left ventricular remodeling and dysfunction than is non-Q wave infarction
TANGENT BUNDLES OF LP-SASAKIAN MANIFOLD ENDOWED WITH GENERALIZED SYMMETRIC METRIC CONNECTION
The aim of the present work is to study and establish conditions for anLP-Sasakian manifold on the tangent bundle . An LP-Sasakian manifold with the generalized symmetric metric connection on is investigated. Next, the curvature tensor and the Ricci tensor of an LP-Sasakian manifold with respect to the generalized symmetric metric connection on are calculated. Moreover, the projective curvature tensor with respect to the generalized symmetric metric connection on is studied and showed that is not -projectively flat. In particular, if and then is -projectively flat
VGDRA: A Virtual Grid-Based Dynamic Routes Adjustment Scheme for Mobile Sink-Based Wireless Sensor Networks
In wireless sensor networks, exploiting the sink mobility has been considered as a good strategy to balance the nodes energy dissipation. Despite its numerous advantages, the data dissemination to the mobile sink is a challenging task for the resource constrained sensor nodes due to the dynamic network topology caused by the sink mobility. For efficient data delivery, nodes need to reconstruct their routes toward the latest location of the mobile sink, which undermines the energy conservation goal. In this paper, we present a virtual gridbased dynamic routes adjustment (VGDRA) scheme that aims to minimize the routes reconstruction cost of the sensor nodes while maintaining nearly optimal routes to the latest location of the mobile sink. We propose a set of communication rules that governs the routes reconstruction process thereby requiring only a limited number of nodes to readjust their data delivery routes toward the mobile sink. Simulation results demonstrate reduced routes reconstruction cost and improved network lifetime of the VGDRA scheme when compared with existing work
Enhanced Tunnelling in a Hybrid of Single-Walled Carbon Nanotubes and Graphene
Transparent and conductive films (TCFs) are of great technological
importance. The high transmittance, electrical conductivity and mechanical
strength make single-walled carbon nanotubes (SWCNTs) a good candidate for
their raw material. Despite the ballistic transport in individual SWCNTs,
however, the electrical conductivity of their networks is limited by low
efficiency of charge tunneling between the tube elements. Here, we demonstrate
that the nanotube network sheet resistance at high optical transmittance is
decreased by more than 50% when fabricated on graphene and thus provides a
comparable improvement as widely adopted gold chloride ()
doping. However, while Raman spectroscopy reveals substantial changes in
spectral features of doped nanotubes, no similar effect is observed in presence
of graphene. Instead, temperature dependent transport measurements indicate
that graphene substrate reduces the tunneling barrier heights while its
parallel conductivity contribution is almost negligible. Finally, we show that
combining the graphene substrate and doping, the SWCNT thin
films can exhibit sheet resistance as low as 36 /sq. at 90%
transmittance.Comment: 21 pages, 6 figure
Synthesis, Characterization and Bioactivities of Some Novel Oxovanadium(IV) Glycinato Complexes
The novel oxovanadium(IV) complexes, [VIVO(GlyH)(Gly)]+ClO4 - .H2O (1), [VIVO(GlyH)(Gly)]+NO3 - .H2O (2), [VIVO(GlyH)(Gly)]+CH3COO- .H2O (3) were synthesized and characterized by FT-IR, UV-Vis and 1H NMR spectroscopic measurements. The cumulative spectroscopic assessment envisaged that, the complexes adopt a square pyramidal structure, in which the two glycine ligands coordinate to vanadium(IV) center in bidentate fashions conforming a homoleptic structure. The amino nitrogen and a carboxylato oxygen atom coordinate the vanadium(IV) center from both sides making a five members chelate by each side. All the complexes are stable in amorphous state and in aerobic and anaerobic solution. Significantly, all the complexes have the antifungal activities against Aspergillus niger and Penicillium notatum but ineffective against Candida tropicalis. No antibacterial activity was observed for the complexes against tested bacteria and unfortunately, they were found cytotoxic against brine shrimp bioassay
GA Based Sensing of Sparse Multipath Channels with Superimposed Training Sequence
This paper proposes an improved Genetic Algorithms (GA) based sparse multipath channels estimation technique with Superimposed Training (ST) sequences. A non-random and periodic training sequence is proposed to be added arithmetically on the information sequence for energy efficient channel estimation within the future generation of wireless receivers. This eliminates the need of separate overhead time/frequency slots for training sequence. The results of the proposed technique are compared with the techniques in the existing literature -the notable first order statistics based channel estimation technique with ST. The normalized channel mean-square error (NCMSE) and bit-error-rate (BER) are chosen as performance measures for the simulation based analysis. It is established that the proposed technique performs better in terms of the accuracy of estimated channel; subsequently the quality of service (QoS), while retrieving information sequence at the receiver. With respect to its comparable counterpart, the proposed GA based scheme delivers an improvement of about 1dB in NCMSE at 12 dB SNR and a gain of about 2 dB in SNR at 10-1 BER, for the population size set at twice the length of channel. It is also demonstrated that, this achievement in performance improvement can further be enhanced at the cost of computational power by increasing the population size
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