A square cored PCF (SC-PCF) sensor is proposed in this paper for the purpose of detecting detrimental chemical analytes (DEHP, BPA, and BPS) that are generally found in different plastic products. ...This SC-PCF sensor is capable of operating in the 1–2 THz regimes. Within this operable range, we found a relatively higher sensitivity of 96.5% along with 95.73% core power fraction, 0.225 numerical aperture, and a lower Aeff of 1.48 × 105 μm2 at 1.9 THz frequency. A tiny confinement loss of 2.68 × 10−13 cm−1 and effective material loss of 0.008 cm−1 are also evaluated. Besides the present fabrication techniques ensures the feasibility of fabrication for this proposed SC-PCF sensor. These estimated results evinced that our proposed sensor can efficiently be used in terms of the noxious chemical compounds, gas, and bio-sensing applications.
Face detection, which is an effortless task for humans, is complex to perform on machines. The recent veer proliferation of computational resources is paving the way for frantic advancement of face ...detection technology. Many astutely developed algorithms have been proposed to detect faces. However, there is little attention paid in making a comprehensive survey of the available algorithms. This paper aims at providing fourfold discussions on face detection algorithms. First, we explore a wide variety of the available face detection algorithms in five steps, including history, working procedure, advantages, limitations, and use in other fields alongside face detection. Secondly, we include a comparative evaluation among different algorithms in each single method. Thirdly, we provide detailed comparisons among the algorithms epitomized to have an all-inclusive outlook. Lastly, we conclude this study with several promising research directions to pursue. Earlier survey papers on face detection algorithms are limited to just technical details and popularly used algorithms. In our study, however, we cover detailed technical explanations of face detection algorithms and various recent sub-branches of the neural network. We present detailed comparisons among the algorithms in all-inclusive and under sub-branches. We provide the strengths and limitations of these algorithms and a novel literature survey that includes their use besides face detection.
Abstract
This work presents the fabrication of Zn
1−x
S:Sn
x
thin films using the chemical bath deposition method and investigates the effects of Sn doping and annealing temperature on the ...structural, optical and electrical properties of ZnS thin films. The XRD patterns show that the relative intensities of the major diffraction peaks increase with Sn dopant incorporation and annealing temperature. Because high-temperature annealing forms several nucleation centers throughout the lattice and dopant incorporation enhances point defects leading to crystallite boundary mobility enhancement, crystallinity is also improved. UV–vis-NIR spectrophotometric studies revealed that the films have good transmittance that is larger than 75% in both visible and near-infrared regions and their optical bandgap ranges from 3.34 eV to 3.90 eV. Both the Sn content and annealing temperature cause the transmittance and the optical bandgap to rise. The absorption edge shifts towards the longer wavelength for higher Sn contents and annealing temperatures. Also, the decreased Urbach energy with increased Sn content or annealing temperature can be attributed to the reduced structural disorders and dislocations of ZnS crystals that are indicated by improved crystallinity. Electrical characterization by the two-point probe method exhibits that at higher annealing temperature grain boundary scattering limits the number of mobile carriers by increasing interatomic binding. On the other hand, due to increased carrier concentration and decreased dislocations resulting from the Sn content or annealing, localized carriers dominate in the bulk crystal state and require higher activation energy to replace an interstitial atom and excite the bulk states.
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•Investigation of energy storage performance of BCT-NZLFO multiferroic composite.•Analysis of negative effect of adding ferrite phase towards energy storage application.•Dependence of ...porosity on ferroelectric properties.
Bulk composite ceramics exhibit promising potential as energy storage materials due to their strong ferroelectric characteristics. To lessen the use harmful Pb based material, multiferroic composite combining ferrite and perovskite ceramics with piezoelectric and ferroelectric traits, have gained prominence for high-efficiency energy systems such as ceramic capacitor. This study focuses on a dual-phase multiferroic ceramic composite, following the formula (1-x) Ba0.77Ca0.23TiO3 + xNi0.6Zn0.25La0.15Fe2O4 (x = 0.0, 0.1, 0.2, and 0.3), prepared via a solid-state reaction process. XRD analysis confirms the presence of cubic perovskite (BaTiO3) and cubic spinel ferrite (NZLFO) phases. SEM images depict uniform microstructures with sporadic pore formations, which decreased in grain size with ferrite addition. The P-E loops reveal relaxor ferroelectric behavior with near-zero remnant polarization (Pr), indicating its suitability as an energy storage medium. The highest energy density efficiency, approximately 54 %, was achieved at x = 0.1. The addition of more than 10 % ferrite significantly affects both the microstructure and energy storage properties.
Household contacts of cholera patients have a 100 times higher risk of developing a cholera infection than the general population. To compare the genetic relatedness of clinical and water source ...Vibrio cholerae isolates from cholera patients' households across three outbreaks, we analyzed these isolates using whole-genome-sequencing (WGS) and multilocus variable-number tandem-repeat analysis (MLVA).
The WGS analyses revealed that 80% of households had source water isolates that were more closely related to clinical isolates from the same household than to any other isolates. While in another 20% of households an isolate from a person was more closely related to clinical isolates from another household than to source water isolates from their own household. The mean pairwise differences in single nucleotide-variant (SNV) counts for isolates from the same household were significantly lower than those for different households (2.4 vs. 7.7 p < 0.0001), and isolates from the same outbreak had significantly fewer mean pairwise differences compared to isolates from different outbreaks (mean: 6.2 vs. 8.0, p < 0.0001). Based on MLVA in outbreak 1, we observed that the majority of households had clinical isolates with MLVA genotypes related to other clinical isolates and unrelated to water source isolates from the same household. While in outbreak 3, there were different MLVA genotypes between households, however within the majority of households, the clinical and water source isolates had the same MLVA genotypes. The beginning of outbreak 2 resembled outbreak 1 and the latter part resembled outbreak 3. We validated our use of MLVA by comparing it to WGS. Isolates with the identical MLVA genotype had significantly fewer mean pairwise SNV differences than those isolates with different MLVA genotypes (mean: 4.8 vs. 7.7, p < 0.0001). Furthermore, consistent with WGS results, the number of pairwise differences in the five MLVA loci for isolates within the same household was significantly lower than isolates from different households (mean: 1.6 vs. 3.0, p < 0.0001).
These results suggest that transmission patterns for cholera are a combination of person-to-person and water-to-person cholera transmission with the proportions of the two modes varying within and between outbreaks.
Household contacts of cholera patients are at a 100 times higher risk of developing cholera than the general population. The objective of this study was to examine the incidence of V. cholerae ...infections among household contacts of cholera patients in a rural setting in Bangladesh, to identify risk factors for V. cholerae infections among this population, and to investigate transmission pathways of V. cholerae using multilocus variable-number tandem-repeat analysis (MLVA).
Stool from household contacts, source water and stored water samples were collected from cholera patient households on Day 1, 3, 5, and 7 after the presentation of the index patient at a health facility. Two hundred thirty clinical and water V. cholerae isolates were analyzed by MLVA. Thirty seven percent of households had at least one household contact with a V. cholerae infection. Thirteen percent of households had V. cholerae in their water source, and 27% had V. cholerae in stored household drinking water. Household contacts with V. cholerae in their water source had a significantly higher odds of symptomatic cholera (Odds Ratio (OR): 5.49, 95% Confidence Interval (CI): 1.07, 28.08). Contacts consuming street vended food had a significantly higher odds of a V. cholerae infection (OR: 9.45, 95% CI: 2.14, 41.72). Older age was significantly associated with a lower odds of a V. cholerae infection (OR: 0.96, 95% CI: 0.93, 0.99). Households with both water and clinical V. cholerae-positive samples all had isolates that were closely related by MLVA.
These findings emphasize the need for interventions targeting water treatment and food hygiene to reduce V. cholerae infections.
As detection of specific deoxyribonucleic acid (DNA) sequences is of great importance in diagnosing many fatal and genetic diseases, there have been renewed interests in designing highly sensitive ...label-free DNA detection platforms. This paper presents a molybdenum diselenide (MoSe
2
)-graphene hybrid structure-based surface plasmon resonance (SPR) biosensor with capability of detecting single-nucleotide polymorphism (SNP) and DNA hybridization events. Because of its better absorption capability the MoSe
2
layer provides strong excitation energy which induces huge charge carrier transfer while the graphene layer serves as a biomolecular recognition element to capture bio-analytes through
π
-stacking force. The silver (Ag) layer is attached to the BK7 prism by a very thin titanium (Ti) adhesion film which also serves as oxidization and corrosion protection layer. The biosensor is optimized by numerical modeling and the optimum structure has an excellent sensitivity of 215.5°/RIU which is better than other reported works. It has been demonstrated that when target DNAs are attached to the probe DNAs pre-immobilized on the sensing surface the change of SPR angle is insignificant for mismatched DNA strands while it is highly prominent for complementary DNA strands. Thus, the proposed sensor can effectively distinguish hybridization event and SNP by examining the level of changes in resonance angle and reflectance spectrum.
During recent decades, Bangladesh has experienced a rapid epidemiological transition from communicable to non-communicable diseases. Coronary heart disease (CHD), with myocardial infarction (MI) as ...its main manifestation, is a major cause of death in the country. However, there is limited reliable evidence about its determinants in this population. The Bangladesh Risk of Acute Vascular Events (BRAVE) study is an epidemiological bioresource established to examine environmental, genetic, lifestyle and biochemical determinants of CHD among the Bangladeshi population. By early 2015, the ongoing BRAVE study had recruited over 5000 confirmed first-ever MI cases, and over 5000 controls "frequency-matched" by age and sex. For each participant, information has been recorded on demographic factors, lifestyle, socioeconomic, clinical, and anthropométrie characteristics. A 12-lead electrocardiogram has been recorded. Biological samples have been collected and stored, including extracted DNA, plasma, serum and whole blood. Additionally, for the 3000 cases and 3000 controls initially recruited, genotyping has been done using the CardioMetabochip+ and the Exome-h arrays. The mean age (standard deviation) of MI cases is 53 (10) years, with 88 % of cases being male and 46 % aged 50 years or younger. The median interval between reported onset of symptoms and hospital admission is 5 h. Initial analyses indicate that Bangladeshis are genetically distinct from major non-South Asian ethnicities, as well as distinct from other South Asian ethnicities. The BRAVE study is well-placed to serve as a powerful resource to investigate current and future hypotheses relating to environmental, biochemical and genetic causes of CHD in an important but under-studied South Asian population.
Unsafe food is linked to the deaths of an estimated two million people annually. Food containing harmful agents is responsible for more than 200 diseases ranging from diarrhoea to cancers. A ...one-sample pilot intervention study was conducted to evaluate the role of courtyard counselling meetings as the means of intervention for improving food safety knowledge and practices among household food handlers in a district of Bangladesh. The study was conducted in three phases: a baseline survey, the intervention and an end-line survey between April and November 2015 where 194 food handlers took part. Data were collected through observations and face-to-face interviews. The mean age of the respondents was 38.8 (±12.4) years, all of whom were females. Hand washing before eating, and washing utensils with soap were significantly improved at the end-line in comparison to the baseline (57% vs. 40% and 83% vs. 69%, respectively). Hand washing with soap was increased by 4%. The mean score of food handling practices was significantly increased after the intervention (20.5 vs. 22.1; P<0.001). However, hand washing after use of toilet was unchanged after the intervention (75% vs.76%). Knowledge about safe food and the necessity of thorough cooking were significantly increased after the intervention (88% from 64% and 34% from 21%, respectively). Mean scores of knowledge and practice on food safety were significantly increased by 1.9 and 1.6, respectively after the one month intervention. Thus this food safety education in rural communities should be scaled up and, indeed, strengthened using the courtyard counselling meetings in Bangladesh.
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