A time-domain control signal detection technique for OFDM

Transmission of system-critical control information plays a key role in efficient management of limited wireless network resources and successful reception of payload data information. This paper uses an orthogonal frequency division multiplexing (OFDM) architecture to investigate the detection performance of a time-domain approach used to detect deterministic control signalling information. It considers a type of control information chosen from a finite set of information, which is known at both transmitting and receiving wireless terminals. Unlike the maximum likelihood (ML) estimation method, which is often used, the time-domain detection technique requires no channel estimation and no pilots as it uses a form of time-domain correlation as the means of detection. Results show that when compared with the ML method, the time-domain approach improves detection performance even in the presence of synchronisation error caused by carrier frequency offset

Heterotopic Ossifications in a Mouse Model of Albright Hereditary Osteodystrophy

Albright hereditary osteodystrophy (AHO) is characterized by short stature, brachydactyly, and often heterotopic ossifications that are typically subcutaneous. Subcutaneous ossifications (SCO) cause considerable morbidity in AHO with no effective treatment. AHO is caused by heterozygous inactivating mutations in those GNAS exons encoding the α-subunit of the stimulatory G protein (Gαs). When inherited maternally, these mutations are associated with obesity, cognitive impairment, and resistance to certain hormones that mediate their actions through G protein-coupled receptors, a condition termed pseudohypoparathyroidism type 1a (PHP1a). When inherited paternally, GNAS mutations cause only AHO but not hormonal resistance, termed pseudopseudohypoparathyroidism (PPHP). Mice with targeted disruption of exon 1 of Gnas (GnasE1−/+) replicate human PHP1a or PPHP phenotypically and hormonally. However, SCO have not yet been reported in GnasE1+/− mice, at least not those that had been analyzed by us up to 3 months of age. Here we now show that GnasE1−/+ animals develop SCO over time. The ossified lesions increase in number and size and are uniformly detected in adult mice by one year of age. They are located in both the dermis, often in perifollicular areas, and the subcutis. These lesions are particularly prominent in skin prone to injury or pressure. The SCO comprise mature bone with evidence of mineral deposition and bone marrow elements. Superficial localization was confirmed by radiographic and computerized tomographic imaging. In situ hybridization of SCO lesions were positive for both osteonectin and osteopontin. Notably, the ossifications were much more extensive in males than females. Because GnasE1−/+ mice develop SCO features that are similar to those observed in AHO patients, these animals provide a model system suitable for investigating pathogenic mechanisms involved in SCO formation and for developing novel therapeutics for heterotopic bone formation. Moreover, these mice provide a model with which to investigate the regulatory mechanisms of bone formation

The Role of Ethnic Directors in Corporate Social Responsibility: Does Culture matter? The Cultural Trait Theory Perspectives

This paper investigates the effect of cultural differences between ethnic directors on corporate social responsibility (CSR) of Public Liability Companies (PLCs) in Nigeria. Using the cultural trait theory, the study focuses on how the ethnic directors are influenced when making decisions concerning CSR. Adopting multiple regression analysis of data, the study investigates the three major ethnic groups (Yoruba, Igbo and Hausa) and finds cultural differences between the ethnic directors affect the adoption of CSR. Empirical results indicate that ethnic directors (Yoruba, Igbo and Hausa) were positively and significantly related to CSR. The paper contributes to the corporate governance and CSR debate concerning how ethnic directors’ decisions impact on CSR activities, particularly on the directors who are individualistic and collectivists towards CSR

Financial and corporate social performance in the UK listed firms: the relevance of non-linearity and lag effects

Using environmental, social and governance scores compiled by Reuters Datastream for each company’s corporate social performance (CSP), we examine the relationship between CSP and corporate financial performance (CFP) of 314 UK listed companies over the period 2002–2015. We further evaluate the relationship between prior and subsequent CFP and prior and subsequent CSP. Based on the system-GMM estimation method, we provide direct evidence that suggests that while CFP and CSP can be linked linearly; however, when we examine the impact of CSP on CFP, the association is more non-linear (cubic) than linear. Our results suggest that firms periodically adjust their level of commitment to society, in order to meet their target CSP. The primary contributions of this paper are testing (1) the non-monotonous relationship between CSP and CFP, (2) the lagged relationship between the two and the optimality of CSP levels, and (3) the presence of a virtuous circle. Our results further suggest that CSP contributes to CFP better during post-crisis years. Our findings are robust to year-on-year changes in CFP and CSP, financial versus non-financial firms, and the intensity of corporate social responsibility (CSR) engagement across industries

Measuring the adhesion of alumina coatings onto Fecralloy supports using a mechanical testing system

Tightening legislation for vehicles across the world has caused the use of monolith catalysts in automotive emission control to become ubiquitous. Control of the surface adhesion of the platinum group metal (PGM) coating onto the monolith block, to maximise catalytic performance for a minimum PGM loading, is therefore paramount. In this paper, an automatic film application is used for coating γ-alumina slurries onto Fecralloy ®, an integral component of metallic monolith catalysts, to achieve the desired coating properties. A newly devised dual compression-tension technique using a mechanical testing system (MTS) is used for measuring the coating adhesion. This method involves compression of the coating with a probe at a fixed load, and then removing the probe together with the coating at right angles to the substrate surface at a speed of 10 mm/min. The MTS results are compared with those from conventional ultrasonic vibration tests. It is found that at 40 wt% solids concentration, the coatings of the finest particles (d 0.9 of 12.14 μm) showed the best adhesion with an ultimate strength of 0.59 MPa and 85-90 mass% coating removal. © 2012 Elsevier B.V

Emissions control catalysts: Links between Fecralloy preoxidation and coating adherence

Tightening emissions legislation for vehicles across the world has caused the use of monolith catalysts in automobile emission control to become ubiquitous. In this study, the physiochemical transformations caused by thermal pre-oxidation of the surface of Fecralloy® foil, an integral component of emissions control catalysts, have been studied to assess their role on coating film adherence. The foil coupons were pre-oxidised at 950°C for 0, 5, 10 and 30 h and the mass gain was found to fit a simplified hyperbolic model. Measurements were made of surface topography and microstructure using laser profiling interferometry (LPI) and scanning electron microscopy (SEM), with phase analysis being obtained from X-ray diffraction (XRD). The optimal surface roughness was obtained after 10 h of pre-oxidation, when the surface contained significant amounts of α-alumina arranged as randomly oriented whiskers. Upon coating of the treated foil coupons with γ–alumina slurry, the sample pre-oxidised for 10 h gave the best performance in terms of coating film loading of 7.94 mass % and adherence of less than 10 mass % loss

Influence of preoxidation on Fecralloy efficacy as a catalyst support

Modern techniques were used to study the physiochemical transformations caused by thermal preoxidation of the surface of Fecralloy foil to assess the influence on coating adherence. These techniques consist of the use of a scanning electron microscope (SEM) and a laser profiling interferometer (LPI

Influence of preoxidation on fecralloy efficacy as a catalyst support

Modern techniques were used to study the physiochemical transformations caused by thermal preoxidation of the surface of Fecralloy foil to assess the influence on coating adherence. These techniques consist of the use of a scanning electron microscope (SEM) and a laser profiling interferometer (LPI