1,241 research outputs found

    Characteristics of inhomogeneous jets in confined swirling air flows

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    An experimental program to study the characteristics of inhomogeneous jets in confined swirling flows to obtain detailed and accurate data for the evaluation and improvement of turbulent transport modeling for combustor flows is discussed. The work was also motivated by the need to investigate and quantify the influence of confinement and swirl on the characteristics of inhomogeneous jets. The flow facility was constructed in a simple way which allows easy interchange of different swirlers and the freedom to vary the jet Reynolds number. The velocity measurements were taken with a one color, one component DISA Model 55L laser-Doppler anemometer employing the forward scatter mode. Standard statistical methods are used to evaluate the various moments of the signals to give the flow characteristics. The present work was directed at the understanding of the velocity field. Therefore, only velocity and turbulence data of the axial and circumferential components are reported for inhomogeneous jets in confined swirling air flows

    Behavior of turbulent gas jets in an axisymmetric confinement

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    The understanding of the mixing of confined turbulent jets of different densities with air is of great importance to many industrial applications, such as gas turbine and Ramjet combustors. Although there have been numerous studies on the characteristics of free gas jets, little is known of the behavior of gas jets in a confinement. The jet, with a diameter of 8.73 mm, is aligned concentrically in a tube of 125 mm diameter, thus giving a confinement ratio of approximately 205. The arrangement forms part of the test section of an open-jet wind tunnel. Experiments are carried out with carbon dioxide, air and helium/air jets at different jet velocities. Mean velocity and turbulence measurements are made with a one-color, one-component laser Doppler velocimeter operating in the forward scatter mode. Measurements show that the jets are highly dissipative. Consequently, equilibrium jet characteristics similar to those found in free air jets are observed in the first two diameters downstream of the jet. These results are independent of the fluid densities and velocities. Decay of the jet, on the other hand, is a function of both the jet fluid density and momentum. In all the cases studied, the jet is found to be completely dissipated in approximately 30 jet diameters, thus giving rise to a uniform flow with a very high but constant turbulence field across the confinement

    Effect of sodium chloride concentration on the functional properties of selectec Legume flours

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    Providing safe, nutritious, and wholesome food for poor and undernourished populations has been a major challenge for developing countries. This has led to the necessity of assembling complete food composition tables, yielding information about the traditional foods and on the functional properties of the plant foods that are consumed regularly in the developing countries. Sodium Chloride (NaCl) is the common salt used at household and industry levels to improve palatability of processed foods. Therefore, the main aim of the present study was to investigate the influence of different concentrations of NaCl on the functional properties of selected legume flours. The effect of increasing concentration of NaCl on the protein solubility, emulsifying and foaming properties of white bean, pigeon pea, cowpea and hyacinth bean were studied. The results revealed that the protein solubility of pigeon pea, cowpea and white bean flours significantly increased by increasing salt concentration and reached a maximum at 0.4 M NaCl (for pigeon pea and cowpea flours) and 0.6 M for white bean flour and then gradually decreased at higher salt concentration. The protein solubility profile of hyacinth bean fluctuated with the salt concentration, with the highest solubility at 0.6 M NaCl and lowest solubility at 0.4M NaCl. With the exception of white bean, the maximum emulsifying activity of all selected legume flours was found at 0.4 M NaCl whereas that of white bean was found at 0.2 M NaCl. Generally, with increasing salt concentration, the emulsifying activity slightly decreased for the legume flours, except for cowpea which fluctuated. Addition of NaCl significantly decreased the emulsion stability and foaming capacity of the four of selected legume with the maximum improvement being observed at 0.2 M NaCl, and then decreasing gradually at higher salt concentration. Significant improvement of foaming stability was observed when salt concentration increased. Based on the results of the present study the selected legume flour demonstrated good functional properties following the addition of NaCl, which makes these legume flours potential ingredients for application in salt containing foods.Keywords: functional properties, Legumes, Protein solubilityAfrican Journal of Food, Agriculture, Nutrition and Development, Volume 12 No.

    Secrecy outage performance analysis for energy harvesting sensor networks with a jammer using relay selection strategy

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    In this paper, we study radio frequency energy harvesting (EH) in a wireless sensor network in the presence of multiple eavesdroppers (EAVs). Specifically, the sensor source and multiple sensor relays harvest energy from multiple power transfer stations (PTSs), and then, the source uses this harvested energy to transmit information to the base station (BS) with the help of the relays. During the transmission of information, the BS typically faces a risk of losing information due to the EAVs. Thus, to enhance the secrecy of the considered system, one of the relays acts as a jammer, using harvested energy to generate interference with the EAVs. We propose a best-relay-and-best-jammer scheme for this purpose and compare this scheme with other previous schemes. The exact closed-form expression for the secrecy outage probability (SOP) is obtained and is validated through Monte Carlo simulations. A near-optimal EH time algorithm is also proposed. In addition, the effects on the SOP of key system parameters such as the EH efficiency coefficient, the EH time, the distance between the relay and BS, the number of PTSs, the number of relays, and the number of EAVs are investigated. The results indicate that the proposed scheme generally outperforms both the best-relay-and-random-jammer scheme and the random-relay-and-best-jammer scheme in terms of the secrecy capacity

    Knowledge, attitudes, and willingness of healthcare workers in Iraq’s Kurdistan region to vaccinate against human monkeypox: a nationwide cross-sectional study

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    Although human monkeypox infections had not been recorded in the Kurdistan region of Iraq as of August 2023, the rapid growth of cases worldwide and the detection of monkeypox in neighboring Middle Eastern nations call for careful planning and timely response measures. Educating and empowering frontline healthcare workers (HCWs) so that they can act to curb the spread of monkeypox infections are core elements of primary prevention and protecting public health. Therefore, this study aimed to assess HCWs’ knowledge and attitudes about monkeypox and their willingness to vaccinate against monkeypox. By employing a convenience sampling method, an online survey was disseminated via Google Forms between 1 November 2022 and 15 January 2023. The researchers utilized regression analyses to ascertain the factors associated with the three parameters: knowledge, attitude, and the willingness to vaccinate. A total of 637 HCWs were included in the analysis (ages ranged between 21 and 51 years). The mean overall scores were 8.18 of a max score of 16 (SD 3.37), 3.4 of 5 (SD 1.37), and 2.41 of 5 (SD 1.25) for knowledge, attitude, and willingness to vaccinate, respectively. A multivariate logistic regression analysis demonstrated that HCWs who had heard about monkeypox before 2022 rather than later had a higher level of knowledge (AOR: 4.85; 95% CI: 2.81–8.36; p < 0.001). In addition, those who had newly joined the workforce or had less than 1 year experience in practice had more positive attitudes about curbing monkeypox (AOR: 0.35; 95% CI: 0.20–0.59; p < 0.01) than those who practiced for longer. No significant predictors of willingness to vaccinate against monkeypox were identified. The research revealed that HCWs exhibited a relatively low level of monkeypox knowledge. They also had poor attitudes towards monkeypox vaccination and were therefore reluctant to receive the vaccines. Imparting knowledge about the infectious disease can cultivate better awareness and attitudes among HCWs as to their roles in mitigating the spread of an epidemic in the foreseeable future

    Addenbrooke’s Cognitive Examination III: Psychometric Characteristics and Relations to Functional Ability in Dementia

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    Objectives: The Addenbrooke’s Cognitive Examination (ACE) is a common cognitive screening test for dementia. Here, we examined the relationship between the most recent version (ACE-III) and its predecessor (ACE-R), determined ACE- III cutoff scores for the detection of dementia, and explored its relationship with functional ability. Methods: Study 1 included 199 dementia patients and 52 healthy controls who completed the ACE-III and ACE-R. ACE-III total and domain scores were regressed on their corresponding ACE-R values to obtain conversion formulae. Study 2 included 331 mixed dementia patients and 87 controls to establish the optimal ACE-III cutoff scores for the detection of dementia using receiver operator curve analysis. Study 3 included 194 dementia patients and their carers to investigate the relationship between ACE-III total score and functional ability. Results: Study 1: ACE-III and ACE-R scores differed by ≤1 point overall, the magnitude varying according to dementia type. Study 2: a new lower bound cutoff ACE-III score of 84/100 to detect dementia was identified (compared with 82 for the ACE-R). The upper bound cutoff score of 88/100 was retained. Study 3: ACE-III scores were significantly related to functional ability on the Clinical Dementia Rating Scale across all dementia syndromes, except for semantic dementia. Conclusions: This study represents one of the largest and most clini- cally diverse investigations of the ACE-III. Our results demonstrate that the ACE-III is an acceptable alternative to the ACE-R. In addition, ACE-III performance has broader clinical implications in that it relates to carer reports of functional impairment in most common dementias. (JINS, 2018, 24, 854–863

    Novel VPS13B Mutations in Three Large Pakistani Cohen Syndrome Families Suggests a Baloch Variant with Autistic-Like Features.

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    BackgroundCohen Syndrome (COH1) is a rare autosomal recessive disorder, principally identified by ocular, neural and muscular deficits. We identified three large consanguineous Pakistani families with intellectual disability and in some cases with autistic traits.MethodsClinical assessments were performed in order to allow comparison of clinical features with other VPS13B mutations. Homozygosity mapping followed by whole exome sequencing and Sanger sequencing strategies were used to identify disease-related mutations.ResultsWe identified two novel homozygous deletion mutations in VPS13B, firstly a 1 bp deletion, NM_017890.4:c.6879delT; p.Phe2293Leufs*24, and secondly a deletion of exons 37-40, which co-segregate with affected status. In addition to COH1-related traits, autistic features were reported in a number of family members, contrasting with the "friendly" demeanour often associated with COH1. The c.6879delT mutation is present in two families from different regions of the country, but both from the Baloch sub-ethnic group, and with a shared haplotype, indicating a founder effect among the Baloch population.ConclusionWe suspect that the c.6879delT mutation may be a common cause of COH1 and similar phenotypes among the Baloch population. Additionally, most of the individuals with the c.6879delT mutation in these two families also present with autistic like traits, and suggests that this variant may lead to a distinct autistic-like COH1 subgroup

    Eccrine Angiomatous Hamartoma Mimicking a Traumatic Hemorrhage

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    Eccrine angiomatous hamartoma (EAH) is a rare benign disease that is characterized by an abnormal proliferation of eccrine glands and vascular elements. It is generally congenital, but it can appear before puberty. It usually presents as a single plaque or nodule, but multiple patch-like lesions are also possible. EAH is mostly asymptomatic, but it is sometimes associated with pain or hyperhidrosis. It generally does not require aggressive treatment, but the lesion can be excised due to pain, enlargement and cosmetic reasons. A 3-week-old Korean female presented with a hemorrhagic skin lesion on the right foot since birth. There was no specific birth history. The lesion first appeared on the third toe of the right foot and quickly spread to almost half of the right foot. Histopathology examination revealed acanthosis in the epidermis and a proliferation of eccrine ducts, glands and capillaries. The eccrine glands were immunohistochemically-positive for carcinoembryonic antigen

    Synthesis and in vitro antiproliferative activity of new 1-phenyl-3-(4-(pyridin-3-yl)phenyl)urea scaffold-based compounds

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    A new series of 1-phenyl-3-(4-(pyridin-3-yl)phenyl)urea derivatives were synthesized and subjected to in vitro antiproliferative screening against National Cancer Institute (NCI)-60 human cancer cell lines of nine different cancer types. Fourteen compounds 5a-n were synthesized with three different solvent exposure moieties (4-hydroxylmethylpiperidinyl and trimethoxyphenyloxy and 4-hydroxyethylpiperazine) attached to the core structure. Substituents with different π and σ values were added on the terminal phenyl group. Compounds 5a-e with a 4-hydroxymethylpiperidine moiety showed broad-spectrum antiproliferative activity with higher mean percentage inhibition values over the 60-cell line panel at 10 µM concentration. Compound 5a elicited lethal rather than inhibition effects on SK-MEL-5 melanoma cell line, 786-0, A498, RXF 393 renal cancer cell lines, and MDA-MB-468 breast cancer cell line. Two compounds, 5a and 5d showed promising mean growth inhibitions and thus were further tested at five-dose mode to determine median inhibitory concentration (IC50) values. The data revealed that urea compounds 5a and 5d are the most active derivatives, with significant efficacies and superior potencies than paclitaxel in 21 different cancer cell lines belonging particularly to renal cancer and melanoma cell lines. Moreover, 5a and 5d had superior potencies than gefitinib in 38 and 34 cancer cell lines, respectively, particularly colon cancer, breast cancer and melanoma cell lines
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