1,887 research outputs found
A beam steering technique using dielectric wedges.
The thesis describes a method of' beam steering aimed at
producing a useful amount of deflection of an antenna beam
from boresight, by a simple and Inexpensive method. For
large antennas, It is difficult, as well as expensive, to
steer the beam by more than a few beamwidths. The method
studied was developed with particular reference to the
beam steering requirements of Direct Broadcast Satellite
flat plate antennas.
The method involves two dielectric wedges, having circular
faces, placed In front of the antenna. By adjusting the
relative angular position of the wedges, the beam can be
steered In any direction, up to a maximum value from the
antenna boresight direction. The maximum value of the
deflection is determined by the wedge angle and the
dielectric constant of the wedge material. This method of
beam steering Is Independent of frequency. Frequency
limitations are, however, set by the need for a matching
layer on the wedge faces to reduce the loss due to
reflection and also due to interference of multiple
reflection effects on the radiation pattern.
Extensive investigations are made (both theoretical and
experimental) to predict the performance of the wedges as
the beam Is steered. The effect of reflection is studied and a new matching technique is devised. Other practical
considerations for example, stepping the wedges for weight
reduction, the effect of loss in the dielectric material
and cross polar performance are also taken into account.
Some effort is given to explore the possibility of using
metal loaded artificial dielectrics using polyurethane as
the base material.
Finally, a number of charts are presented to determine the
amount of beam steering for an arbitrary position of the
wedges
Tourists’ Personal Development Through Participatory Consumer-Generated Content
The paper seeks to investigate key factors influencing the personal development of tourists. This study examines the relationship between participatory consumer-generated content and tourists’ capabilities, emotions, and skills, as well as the moderating effect of previous tourists’ experiences. To evaluate the research model, 301 valid responses were examined using the PLS-SEM technique. The empirical findings showed that participatory consumer-generated content positively relates to tourists’ capabilities, emotions, and skills. Moreover, previous tourists’ experiences moderate the relationships of participatory consumer-generated content with tourists’ capabilities and skills; however, previous tourists’ experiences have no moderation effect on tourists’
emotions. Thus, our paper's findings offer valuable contributions to theory and practice. Practitioners and
authorities should stimulate users to share their tourism experiences and take the initiative to share easily traceable and searchable data. Moreover, businesses should implement activities that encourage tourists to share their experiences as soon as possible and make travel and tourism websites and social media platforms readily available
Corporate Social Responsibility, Sustainability Governance and Sustainable Performance: A Preliminary Insight
This conceptual paper aims to investigate corporate social responsibility (CSR) practises in the tourism sector. Drawing on the existing literature, this study conceptualises the linkage between CSR, sustainability governance, and sustainable performance. Moreover, this study conceptualises three sub-dimensions of CSR. The integration of CSR in the tourism sector is significant and novel. An analytical review is conducted to present conceptual linkage and research implications. The finding implies that CSR positively influences the sustainable performance of organisations and sustainable governance plays a mediating role between relationships. This study provides important implications that help tourism industry practitioners to realise the significance of reducing environmental and social problems, which cause by tourism activities. Further, this study obtains support from institutional theory to explain the relationships of governance mechanism and CSR that leads to economic performance as well as create value for nature and the local community. Additionally, the future direction of research is provided that highlights some important avenues in the sustainability fiel
Carbon neutrality concept and progress
Sufficient scientific evidence now shows that Earth’s temperature is warmer than before. The temperature of the planet (global warming) is becoming s source of climate change that is estimated to have negative consequences for all living beings (Sovacool and Griffiths, 2020). Climate change, if it keeps moving in the direction in which it is heading now, will have severe consequences for anything and everything that exists on this planet. This is not a man-made story; rather, the argument is established upon the data collected by international organizations such as United Nations’ Intergovernmental Panel on Climate Change, Environmental Protection Agency, and NASA, among others. Data on global warming have been gathered across multiple time periods and analyzed for a very long time to arrive at the conclusion of severe and unpleasant consequences for everyone and everything on the planet. Excessive carbon dioxide emis- sions is the main contributing factor of global warming. However, it is not only carbon dioxide that causes global warming—many other gases are harmful to the climate, such as carbon dioxide, methane, and nitrous oxide, as well as hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. This is not an exhaustive list, but for now, think of greenhouse gases as a catch-all term for the harmful substances we are pumping into the atmo- sphere. Since carbon dioxide has the most significant share among harmful gases, academic and nonacademic researchers study carbon dioxide more than other gases
Enhancing business performance through green human resource management practices: an empirical evidence from Malaysian manufacturing industry
Sustainability has come under public policy limelight. Organizations are investing to minimize the impact of environmental degradation to build their image as an environmentally friendly firm, which contributes to their business performance as well. Literature suggests that green
organizational indicators are found to be positively related to firm sustainable performance. More specifically green human resource management (GHRM) practices strengthen the firm’s
environmental practices and enhance employee morale toward green practices. The paper aims to investigate the impact of GHRM indicators on environmental performance (EP) and business
performance (BP)
The differential modulation of receptor tyrosine kinase Axl in human mesenchymal stromal cell responses to modified titanium surfaces
Osseointegration is the process of de novo bone regeneration on the surface of an endosseous
titanium (Ti) implant in vivo. This neo formation of bone underlies the physical integration of a Ti
implant in bone at a level sufficient to restore loss of function; for example, of mastication due to
absent teeth. The outer atoms of a bulk of Ti metal form a stable and passive surface oxide layer
that serves as a substrate for the amalgamation of tissue reparative components, which entail the
formation of an osseous bond between tissue and fixture. This interaction was empirically
demonstrated to be highly affected by the characteristics of the surface an implant in experimental
studies querying the varied effects of additive or subtractive physical modifications, as well as
altered chemical compositions, of Ti implant surfaces on osseointegration. Subsequent clinical and
experimental practices have demonstrated that rough surfaced implants perform comparatively
‘better’ than their smooth surfaced counterparts by promoting bone growth on the fixture. Moreover,
a particular surface modification that yields high surface energy combined with a widely tested
micron scaled topographical roughness (modSLA) has been shown to further promote the timely
enhancement of osseointegration compared to its hydrophobic rough counterpart (SLA). The
biological mechanisms underlying this apparent enhancement of osseointegration by modified Ti
implant surfaces are still subject to intense study due to the materials’ implications in bone related
tissue engineering applications. Amongst the several views being opined is a proposition mainly
arising from in vitro experimentation, which suggests modified Ti implant surfaces possess an
‘intrinsic’ osteoinductive potential that affects uncommitted reparative cells by inducing a temporal
and magnitudinal enhancement in cellular differentiation and function; in turn, implying the early
formation of functional osteoblasts and bone tissue matrix in an in vivo scenario. The observations
of differential cellular behavior include the apparent modulation by the modified surfaces, of a cell
surface receptor tyrosine kinase Axl in human osteoblasts. The proposed role of the receptor in
negatively regulating osteogenic mineralisation in uncommitted pericytic cells suggests an
association with the altered response of cells to these substrates. The aim of this project was to
examine and test the hypothesised differential modulation of Axl in the responses of human marrow
derived mesenchymal stromal cells to modified Ti implant substrates
Preventing oxidation of canola and sunflower oils by addition of pomegranate seed oil
The study was designed to explore the antioxidative effect of pomegranate seed oil (PSO) at different concentrations (5 and 7%) against oxidation of plant-based oils (canola oil and sunflower oil) during storage (60 days) as compared to artificial antioxidant butylated hydroxyanisole (BHA, 200 ppm). Rancimat and Schaal oven analysis were employed for the assessment of potential consequences of PSO against oxidation in plant based oils. The variation in total phenolic contents (TPC), antioxidant activity, peroxide value (POV), and tocopherol contents during storage were evaluated by Schaal oven test at 62 °C. The substantially (P≤0.05) higher induction period (IP) values were observed for PSO blended oil samples as compared to blank oil samples. The addition of PSO in plant-based oils improved the oxidative stability by enhancing the antioxidant potential and TPC, decreasing POV, and slowing down the degradation of tocopherol contents during storage. The findings of the present study suggest that PSO might be used as an alternative potential antioxidant to synthetic antioxidants
Industrial Digitization, the Use of Real-Time Information, and Operational Agility: Digital and Information Perspectives for Supply Chain Resilience
Change is the permanent reality of the digital business world. Firms manage it by their ability and capability to cope with short-term and long-term deviations and disruptions. This paper presents an examination of the supply chain resilience (SCR) of firms operating in the Malaysian Service Sector. The data for this study were collected from 157 managers of 59 firms operating in seven sub-service sectors. Following Organizational Information Processing Theory (OIPT) and reviewing the relevant literature for the conceptualization, we tested a framework that suggests that the use of real-time information (URTI) enhances the
SCR. We also found that the industrial digital environment has an
important link with the URTI. The results indicate that the URTI
is significantly associated with SCR and operational agility, which
partially mediates the relationship between the URTI and SCR.
We further discuss the theoretical contributions and implications
with practical, and policy implications arising from this research
A new cascaded spectral subtraction approach for binaural speech dereverberation and its application in source separation
In this work we propose a new binaural spectral subtraction
method for the suppression of late reverberation. The pro-
posed approach is a cascade of three stages. The first two
stages exploit distinct observations to model and suppress the
late reverberation by deriving a gain function. The musical
noise artifacts generated due to the processing at each stage
are compensated by smoothing the spectral magnitudes of the
weighting gains. The third stage linearly combines the gains
obtained from the first two stages and further enhances the
binaural signals. The binaural gains, obtained by indepen-
dently processing the left and right channel signals are com-
bined using a new method. Experiments on real data are per-
formed in two contexts: dereverberation-only and joint dere-
verberation and source separation. Objective results verify
the suitability of the proposed cascaded approach in both the
contexts
Molecular and biochemical characterization of soil isolates of Aspergillus niger aggregate and an assessment of their antagonism against Rhizoctonia solani
Sixteen Aspergillus niger aggregate isolates collected from different crop fi elds were subjected to RAPDPCR using 20 Operon primers and 8 synthetic primers. Twenty-two primers led to the amplifi cation of 727 fragments ranging from 3500 bp (OPA 11) to 200 bp (primer 06). Two bands were monomorphic, while the rest were polymorphic. Three amplicons produced by OPA 16 were recorded as isolate-specifi c as 2300 bp by AnC2 and AnR3, and as 2800 bp by AnC2 only. The highest genetic similarity (0.79) was measured between AnC2 and AnR3, and the lowest (0.17) between AnC2 and AnR2. Multivariate analysis of genetic similarity revealed three major clusters, named group I, group II and group III. All isolates were ochratoxin A negative
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