283 research outputs found
An estimate for the numerical radius of the Hilbert space operators and a numerical radius inequality
We provide a number of sharp inequalities involving the usual operator norms of Hilbert space operators and powers of the numerical radii. Based on the traditional convexity inequalities for nonnegative real numbers and some generalize earlier numerical radius inequalities, operator. Precisely, we prove that if (), , p, q > 1 with and and are non-negative functions on which are continuous such that for all , then
\begin{equation*} w^{2r}\left({\sum\limits_{i = 1}^{n} {\bf X}_i {\bf A}_i^m {\bf B}_i}\right)\leq \frac{n^{2r-1}}{m}\sum\limits_{j = 1}^{m}\left\Vert{\sum\limits_{i = 1}^{n}\frac{1}{p}S_{i, j}^{pr}+\frac{1}{q}T_{i, j}^{qr}}\right\Vert-r_0\inf\limits_{\left\Vert{\xi}\right\Vert = 1}\rho(\xi), \end{equation*}
where , , and
\rho(\xi) = \frac{n^{2r-1}}{m}\sum\limits_{j = 1}^{m}\sum\limits_{i = 1}^{n}\left({\left<{S_{i, j}^r\xi, \xi}\right>^{\frac{p}{2}}-\left<{T_{i, j}^r\xi, \xi}\right>^{\frac{q}{2}}}\right)^2. </p
Development of economical maximum power point tracking system for solar cell
Photovoltaic (PV) power generation system operates under various isolation conditions, which may generate several maximum output power points on the I-V curve of the PV array and raises serious problem on Maximum Power Point Tracking (MPPT) control of the system. This research concerned the design of MPPT for photovoltaic system by using PIC controller. A MPPT unit is developed for the optimum coupling of a Photovoltaic Panel (PVP) to the battery (load)through a controlled Buck type dc-dc converter which has made the difference from the past MPPT
techniques and made it cost effective. The system has high-efficiency, lower-cost and low-power consumption. Moreover it permits easy modifications. This system operates at its maximum power generation with increasing the PV output power by as much as 32-36%. This study includes the
theoretical aspects and experimental results of the proposed method
Temperature effect analysis on magneto-rheological damper’s performance
Magnetorheological (MR) damper is one of the most advanced applications of semi active damper in controlling vibration. Its use is increasing day by day in the vehicle suspension system due to its continuous controllability in both on and off state. MR damper’s damping force can be controlled by changing the viscosity of its internal magnetorheological fluids (MRF). Applying an external magnetic field viscosity of MRF can be controlled. Electromagnet such as solenoid coil is normally used as external magnetic field source. These coils are attached inside the damper’s piston head. When the damper operates these coils create heat. That’s why the conventional MR dampers normally face wide variations in temperature. This change of temperature results decay in MRF viscosity as well as post-yield damping of the damper. In this paper temperature effect on MR fluids viscosity and on MR dampers performance represented analytically and experimentally. Due to this temperature effect the deviation of MR dampers performance has shown here experimentally. Also a novel technique for solving the problem explained clearly
Yield loss assessment of chickpea caused by botrytis gray mold through fungicide (Bavistin) spray
An experiment was conducted to assess the yield loss of chickpea caused by Botrytis gray mold (BGM) through fungicide spray at Pulses Research Centre, Bangladesh Agricultural Research Institute, Ishurdi, Pabna, Bangladesh. Sixteen entries were evaluated following RCB design with three replications. Out of 16 tested germplasms, eight germplasms (92040*52, FLIP97-530 CLIMS, 94-012*98V4006, FLIP98-106C, Gully, FLIP94-509C, 97020-1489 and S95425) showed resistant reaction, while eight and one entries showed susceptible and highly susceptible, respectably, in fungicide sprayed plot. The highest yield increase over BGM inoculated plot were observed in BARWON*98CIH4007 (180.49%) and 97020-1489 (157.96%). The lowest yield increase over BGM inoculated plot were recorded in HEERA*98CZH4010 (6.39%) and 94-012*98V4006 (8.93%) genotypes
Length–weight relationships of 20 fish species from Pahang River, Maran district, Pahang, Malaysia
This study reports the length–weight relationships (LWR) of 20 fish species from the Pahang River, Maran district, Pahang, Malaysia. The river supplies fishes mainly for local consumption and is a principal body of water for freshwater aquaculture in Malaysia. A total of 12 LWR of fishes were unknown to FishBase, and five new maximum lengths of fishes were identified from the study
Comparison of care and outcomes for myocardial infarction by heart failure status between United Kingdom and Japan
Aims: Prognosis for ST-segment elevation myocardial infarction (STEMI) is worse when heart failure is present on admission. Understanding clinical practice in different health systems can identify areas for quality improvement initiatives to improve outcomes. In the absence of international comparison studies, we aimed to compare treatments and in-hospital outcomes of patients admitted with ST elevation myocardial infarction (STEMI) by heart failure status in two healthcare-wide cohorts. Methods and results: We used two nationwide databases to capture admissions with STEMI in the United Kingdom (Myocardial ischemia National Audit Project, MINAP) and Japan (Japanese Registry of All Cardiac and Vascular Diseases-Diagnostic Procedure Combination, JROAD-DPC) between 2012 and 2017. Participants were stratified using the HF Killip classification into three groups; Killip 1: no congestive heart failure, Killip 2–3: congestive heart failure, Killip 4: cardiogenic shock. We calculated crude rate and case mix standardized risk ratios (CSRR) for use of treatments and in-hospital death. Patients were younger in the United Kingdom (65.4 [13.6] vs. 69.1 [13.0] years) and more likely to have co-morbidities in the United Kingdom except for diabetes and hypertension. Japan had a higher percentage of heart failure and cardiogenic shock patients among STEMI during admission than that in the United Kingdom. Primary percutaneous coronary intervention (pPCI) rates were lower in the United Kingdom compared with Japan, especially for patients presenting with Killip 2–3 class heart failure (pPCI use in patients with Killip 1, 2–3, 4: Japan, 86.2%, 81.7%, 78.7%; United Kingdom, 79.6%, 58.2% and 79.9%). In contrast, beta-blocker use was consistently lower in Japan than in the United Kingdom (61.4% vs. 90.2%) across Killip classifications and length of hospital stay longer (17.0 [9.7] vs. 5.0 [7.4] days). The crude rate of in-hospital mortality increased with increasing Killip class group. Both the crude rate and CSRR was higher in the United Kingdom compared with Japan for Killip 2–3 (15.8% vs. 6.4%, CSRR 1.80 95% CI 1.73–1.87, P < 0.001), and similar for Killip 4 (36.9% vs. 36.3%, CSRR 1.11 95% CI 1.08–1.13, P < 0.001). Conclusions: Important differences in the care and outcomes for STEMI with heart failure exist between the United Kingdom and Japan. Specifically, in the United Kingdom, there was a lower rate of pPCI, and in Japan, fewer patients were prescribed beta blockers and hospital length of stay was longer. This international comparison can inform targeted quality improvement programmes to narrow the outcome gap between health systems
The mechanical performance of sugar palm fibres (Ijuk) reinforced phenolic composites
Sugar palm fibres are one of the natural fibres which have many features and need further study to understand their properties. The aim of this work is to investigate the flexural, compressive and impact properties of sugar palm fibres reinforced phenolic composites. Sugar palm fibres were used as a filler (particle size 150 μm) and with loading of 0, 10, 20, 30, and 40 vol.%. The fibres were treated by sea water and then fabricated into composites by hot press technique. Flexural, compressive, and impact tests were carried out as per ASTM D790, ASTM D695-08a, and ASTM D256 standards, respectively. Scanning electron microscopy (SEM) was used to investigate the morphology and the interfacial bonding of the fibres-matrix in composites. The results show that the mechanical properties of the composites improve with the incorporation of fibres. The composite of 30 vol.% particle loading exhibit optimum values which are 32.23 MPa, 61.66 MPa, and 4.12 kJ/m2 for flexural, compressive, and impact strength, respectively. This was because good compatibility of fibre-matrix bonding. Consequently, sugar palm fibre is one of the prospective fibres and could be used as a potential resource to reinforcement polymer composite
Physics Potential of the ICAL detector at the India-based Neutrino Observatory (INO)
The upcoming 50 kt magnetized iron calorimeter (ICAL) detector at the
India-based Neutrino Observatory (INO) is designed to study the atmospheric
neutrinos and antineutrinos separately over a wide range of energies and path
lengths. The primary focus of this experiment is to explore the Earth matter
effects by observing the energy and zenith angle dependence of the atmospheric
neutrinos in the multi-GeV range. This study will be crucial to address some of
the outstanding issues in neutrino oscillation physics, including the
fundamental issue of neutrino mass hierarchy. In this document, we present the
physics potential of the detector as obtained from realistic detector
simulations. We describe the simulation framework, the neutrino interactions in
the detector, and the expected response of the detector to particles traversing
it. The ICAL detector can determine the energy and direction of the muons to a
high precision, and in addition, its sensitivity to multi-GeV hadrons increases
its physics reach substantially. Its charge identification capability, and
hence its ability to distinguish neutrinos from antineutrinos, makes it an
efficient detector for determining the neutrino mass hierarchy. In this report,
we outline the analyses carried out for the determination of neutrino mass
hierarchy and precision measurements of atmospheric neutrino mixing parameters
at ICAL, and give the expected physics reach of the detector with 10 years of
runtime. We also explore the potential of ICAL for probing new physics
scenarios like CPT violation and the presence of magnetic monopoles.Comment: 139 pages, Physics White Paper of the ICAL (INO) Collaboration,
Contents identical with the version published in Pramana - J. Physic
Benzodiazepine use among adults residing in the urban settlements of Karachi, Pakistan: A cross sectional study
<p>Abstract</p> <p>Background</p> <p>There are hardly any studies carried out in Pakistan on the usage of benzodiazepines at the level of community. This research was aimed to determine the frequency of benzodiazepine use, along with its associations with socio-demographic and clinical characteristics among community dwelling adults, residing in two urban settlements of Karachi, Pakistan.</p> <p>Methods</p> <p>We performed a cross sectional study from August 2008 to December 2009, in 2 areas of Karachi, namely Garden and Sultanabad. We followed the systematic sampling strategy to randomly select the households, with an adult of either sex and of age 18 years or more. Data collection was carried out through interview, using a pre-tested questionnaire, with items on socio-demographic position, medical history and benzodiazepine use. Student's t-test and χ<sup>2 </sup>test was employed to determine the associations between socio-demographic and clinical characteristics, and their relationship with benzodiazepine use was determined using applied logistic regression.</p> <p>Results</p> <p>The overall percentage of benzodiazepine consumption was estimated to be 14%. There were significantly more benzodiazepine users in the peri-urban Sultanabad community to the urban community of Garden (p-value = 0.001). The mean age (± SD) for users was 51.3 (± 15.6) years compared to 37.1 (± 14.4) years among non-users. Bromazepam was the most widely used benzodiazepine (29%); followed by diazepam, with a median duration on primary use being 144 weeks (IQR = 48-240). The adjusted logistic regression model revealed that increasing age, location, female sex, unemployment and psychiatric consultation were associated with increased likelihood of benzodiazepine use.</p> <p>Conclusion</p> <p>We believe the unregulated over-the-counter sales of benzodiazepines and social conditions might be playing a role in this high consumption of benzodiazepines in the community.</p
Impact of Rapid Urbanization on the Rates of Infection by Vibrio cholerae O1 and Enterotoxigenic Escherichia coli in Dhaka, Bangladesh
Bangladesh is a country where acute dehydrating diarrhea or cholera is common and is seen at least two times every year and additionally in natural disasters. In addition cholera cases have increased in the country, especially in urban settings such as in the capital city, Dhaka, where the number of hospitalized patients with more severe disease has tremendously increased. In the present observation, we have concentrated on determining the occurrence of diarrhoea caused by the two most common bacterial agents V. cholerae O1 and enterotoxigenic Escherichia coli (ETEC) in a densely populated, disease prone area Mirpur in Dhaka for two years from March 2008 to February 2010. Stool or rectal specimens from diarrheal patients coming to the ICDDR,B hospital from Mirpur were tested for the two bacterial pathogens. We found that V. cholerae O1 was the major bacterial pathogen and a cause of severe cholera disease in 23% of patients (2,647 of a total of 11,395 patients) from Mirpur. We surmise that cholera vaccines, as well as other public health tools that can target such high risk groups in the country, will be able to reduce the disease morbidity and the transmission of pathogens to improve the quality of life in urban settings
- …