887 research outputs found
EXAMINING THE EFFECT OF HIGH SEASONALITY ON FRONTLINE EMPLOYEES: A CASE STUDY OF FIVE STARS HOTELS IN AQABA
In recent times, the impact of seasonality on tourism industry has been recognized. There has been a distinct lack of studies that focus on the effects of high seasonality on front-line employees (the receptionist) in hotels. Therefore, this study attempted to address the importance of the receptionist job in high seasonality and the effect of high seasonality on them. To answer the questions of the study, an instrument was used for evaluation. Also, a questionnaire was addressed to both employees and managers. T-test, ANOVA, and multiple regressions were utilized to test the hypotheses. The findings of the study revealed that the high seasonality in hotels has effects on the receptionists regarding miscommunication and bad relation with others during work hours. Therefore, this study has several recommendations for both the managers and the enterprises
Farmers' perceptions of climate change and its impact on gum Talha (Acacia seyal var. seyal) production in Bahar Alarab locality, East Darfur State, Sudan
Acacia seyal var. seyal is an essential source of income to farmers in the Bahar Alarab locality in Sudan. Farmers’ perceptions of current climate conditions and their subsequent repercussions on Gum Talha (Acacia seyal var. seyal) production remains poorly investigated and understood. To fill this gap, a survey was carried out within six villages at Bahar Alarab locality in East Darfur State, Sudan, and a total of 391 randomly selected farmers were included in the study. Moreover, rainfall and temperature data over 30 years (1988 – 2020) were analysed. The results revealed that climate change signs were perceived by farmers based on the size of gum production (27.4%), early falling of leaves (26.1%), decline in production (24.3%), and persistent insect attack (22.3%). Moreover, farmers also reported increases (65%) and decreases (19%) in temperature. In contrast, 46.5% of farmers reported that rainfall deficiency was a decreasing factor of production. Accordingly, 69% of respondents perceived an increase in temperature, whereas 49.4% reported a decrease in rainfall frequency. Additionally, the results showed that there was long-term variability in temperature over the past three decades. The results of multinomial logistic regression highlighted that household size is an important factor contributing to the increasing trend of temperature. In addition, the growth and productivity of acacia trees were found to be determinants of farmers’ perception of temperature and precipitation change over the past 30 years. The study suggests a tailored policy that could reduce climate-induced impacts on gum Talha productivity and increase farmers’ gain to avoid poverty in this locality
Cytotoxic Effect of Vincarosea Aqueous Crude Extraction Human Brain Carcinoma Cell Line (AMGM) In Vitro
The present study investigated the cytotoxic effects of aqueous crude extracts of Vincarosea leaves, flowers and seeds on Human brain carcinoma cell line (AMGA, Ahmed Majeed Glioblastoma Multiform ) in vitro, by using serial double dilution (concentration between 1.95-1000 µg/ml). The results showed that the cytotoxic effect of extracts was depended on type of parts of plant extracted, concentration and exposure time. The concentration 1000 µg/ml gave inhibition rate (IR), were (34, 49 and 64) % of leaves, flowers and seeds extracts respectively compared with control 100% after 24 hours from exposure time. However, low concentrations of aqueous extracts were found to induce the AMGA cells growth and proliferation (PR), it was 115% by treatment with aqueous extract offlowers extract in 1.95 µg/ml after 24 hours of exposed
PT-symmetric Solutions of Schrodinger Equation with position-dependent mass via Point Canonical Transformation
PT-symmetric solutions of Schrodinger equation are obtained for the Scarf and
generalized harmonic oscillator potentials with the position-dependent mass. A
general point canonical transformation is applied by using a free parameter.
Three different forms of mass distributions are used. A set of the energy
eigenvalues of the bound states and corresponding wave functions for target
potentials are obtained as a function of the free parameter.Comment: 13 page
Modeling of Efficient Control Strategies for LCC-HVDC Systems: A Case Study of Matiari–Lahore HVDC Power Transmission Line
With the recent development in power electronic devices, HVDC (High Voltage Direct Current) systems have been recognized as the most prominent solution to transmit electric power economically. Today, several HVDC projects have been implemented physically. The conventional HVDC systems use grid commutation converters, and its commutation relies on an AC system for the provision of voltage. Due to this reason, there are possibilities of commutation failure during fault. Furthermore, once the DC (Direct Current) system power is interrupted momentarily, the reversal of work power is likely to cause transient over-voltage, which will endanger the safety of power grid operation. Hence, it is necessary to study the commutation failure and transient over-voltage issues. To tackle the above issues, in this paper, the dynamic and transient characteristics of Pakistan’s first HVDC project, i.e., the Matiari–Lahore ±660 kV transmission line has been analyzed in an electromagnetic transient model of PSCAD/EMTDC. Based on the characteristics of the DC and the off-angle after the failure, a new control strategy has been proposed. The HVDC system along with its proposed control strategy has been tested under various operating conditions. The proposed controller increases the speed of fault detection, reduces the drop of AC voltage and DC and suppresses the commutation failure probability of LCC-HVDC (line commutated converter-high voltage direct current). © 2022 by the authors. Licensee MDPI, Basel, Switzerland
Observation of in
Using a sample of events recorded with
the BESIII detector at the symmetric electron positron collider BEPCII, we
report the observation of the decay of the charmonium state
into a pair of mesons in the process
. The branching fraction is measured for the first
time to be , where the first uncertainty is
statistical, the second systematic and the third is from the uncertainty of
. The mass and width of the are
determined as MeV/ and
MeV.Comment: 13 pages, 6 figure
Observation and study of the decay
We report the observation and study of the decay
using events
collected with the BESIII detector. Its branching fraction, including all
possible intermediate states, is measured to be
. We also report evidence for a structure,
denoted as , in the mass spectrum in the GeV/
region. Using two decay modes of the meson ( and
), a simultaneous fit to the mass spectra is
performed. Assuming the quantum numbers of the to be , its
significance is found to be 4.4, with a mass and width of MeV/ and MeV, respectively, and a
product branching fraction
. Alternatively, assuming , the
significance is 3.8, with a mass and width of MeV/ and MeV, respectively, and a product
branching fraction
. The angular distribution of
is studied and the two assumptions of the
cannot be clearly distinguished due to the limited statistics. In all
measurements the first uncertainties are statistical and the second systematic.Comment: 10 pages, 6 figures and 4 table
Observation of and confirmation of its large branching fraction
The baryonic decay is observed, and the
corresponding branching fraction is measured to be
, where the first uncertainty is statistical
and second systematic. The data sample used in this analysis was collected with
the BESIII detector operating at the BEPCII double-ring collider with
a center-of-mass energy of 4.178~GeV and an integrated luminosity of
3.19~fb. The result confirms the previous measurement by the CLEO
Collaboration and is of greatly improved precision, which may deepen our
understanding of the dynamical enhancement of the W-annihilation topology in
the charmed meson decays
Evidence of a resonant structure in the cross section between 4.05 and 4.60 GeV
The cross section of the process for
center-of-mass energies from 4.05 to 4.60~GeV is measured precisely using data
samples collected with the BESIII detector operating at the BEPCII storage
ring.
Two enhancements are clearly visible in the cross section around 4.23 and
4.40~GeV.
Using several models to describe the dressed cross section yields stable
parameters for the first enhancement, which has a mass of 4228.6 \pm 4.1 \pm
6.3 \un{MeV}/c^2 and a width of 77.0 \pm 6.8 \pm 6.3 \un{MeV}, where the
first uncertainties are statistical and the second ones are systematic.
Our resonant mass is consistent with previous observations of the
state and the theoretical prediction of a molecule.
This result is the first observation of associated with an
open-charm final state.
Fits with three resonance functions with additional , ,
, , or a new resonance, do not show significant
contributions from either of these resonances. The second enhancement is not
from a single known resonance. It could contain contributions from
and other resonances, and a detailed amplitude analysis is required to better
understand this enhancement
First observations of hadrons
Based on events collected with
the BESIII detector, five hadronic decays are searched for via process
. Three of them, ,
, and are observed for the first
time, with statistical significances of 7.4, , and
9.1, and branching fractions of ,
, and ,
respectively, where the first uncertainties are statistical and the second
systematic. No significant signal is observed for the other two decay modes,
and the corresponding upper limits of the branching fractions are determined to
be and at 90% confidence level.Comment: 17 pages, 16 figure
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