bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Polymerization with Argon Laser and LED on Shear Resistance of Adhesive Systems
Authors: Borja de Melo Téssia Richelly Nóbrega , Youssef Michel Nicolau
Published: January 2023

objective: The aim of this work was to evaluate the shear strength of ceramic brackets as a function of two adhesive systems (kit TransbondTM XT; TransbondTM Plus Self Etching Primer/ 3M Unitek®) and two light sources (LED and Argon Laser).
Method: 28 maxillary premolars were used, divided into two groups (n=14), according to the adhesive system and light source. The teeth were enclosed in ¾-inch PVC tubes, with special stone plaster, perpendicular to the ground and tubes. Brackets were fixed over the exposed crowns. The teeth were stored at 37ºC for 24 hours and then submitted to 1,000 thermal cycles with 30 seconds in each bath (5°C and 55°C). The shear test was performed on a Shimadzu® testing machine at a speed of 0.5mm/min. Enamel surfaces were qualified using the ARI (Adhesive Remaining Index). Data were submitted to statistical analyzes ANOVA, Tukey and Kruskal-Wallis (p<0.05).
Results: the conventional TransbondTM XT kit adhesive system was superior to the self-etching system. LED and Argon Laser showed similar behaviors.
Conclusion: Argon laser did not influence shear strength or ARI scores.
Effect of Nanocalcium Carbonate Content on the Properties of PLA Nanocomposites
Authors: Pundir Ankit , Gopala Krishnan P. Santhana , Nayak Sanjay Kumar
Published: January 2023

Even though poly(lactic acid) is one of the most promising biodegradable polymers, less hydrophilic, low impact strength and heat resistance limits its applications. The current study was undertaken to overcome these limitations. Poly(lactic acid)-calcium carbonate nanocomposites were prepared by melt blending technique upto 3 wt. % using master batch containing 4 wt. % of nanocalcium carbonate content. Water absorption and density increased with increase in nanofiller content. Tensile and flexural strength and heat deflection temperature increased up to 1 wt. % of nanofiller content and marginally decreased thereafter. Impact strength increased with increase in nanofiller content and was attributed to cavitation at the polymer-particle boundaries. Impact strength increased to about 200% upon addition of 3 wt. % of nanofiller. TEM studies indicated good dispersion of nanofiller at 1 wt. % and agglomeration at 3 wt. % of nanofiller content. Nanocomposites had lower thermal stability than pristine polymer.
The Environmental Literacy of Lower Secondary School Pupils, High School and College Students
Authors: Kubiatko Milan
Published: January 2023

It is general known fact, the environment problems are still more and more serious. So the environmental education is the important way, how to learn pupils and students about environment and its protection. The main aim of the study was to find out the environmental literacy level of lower secondary school pupils, high school students and college students. Next the influence of age, gender, residence and other variables was determined. The samples size was created by 245 respondents. As the research tool was used Children's Responsible Environmental Behavior Scale (CREBS). The methods of descriptive (mean score, standard error) and inferential statistics (ANOVA) for the data analysis were used. The Cronbach’s alpha was used for the determination of the reliability. The results showed relatively low level of environmental literacy. Higher level of environmental literacy had boys in comparison with girls, next respondents from village in comparison with respondents from town and also the oldest respondents.
Space Technology Advances Application in Town Planning
Authors: Babayeva Nargiz A. , Amenzade Rayxa B. , Rustamov Rustam B.
Published: January 2023

This paper is dedicated space technology advances use architectural design in town planning for selected area of Gobustan district, Azerbaijan. It describes conceptual approach of the process of use space technology in initial stages of design process. This paper briefly observes an option of remote sensing platform for data collection with further geographical information system (GIS) technology applications.
The decision oriented on the importance of linking remote sensing systems with GIS. The use of GIS is contained in application such as image classification, calibration and environmental modeling.
There is clearly great complimentarily between remote sensing and GIS. Existing remote sensing method and GIS technology are operating and functioning independently. It is necessary to mention that by linking the technology, concepts and theories of remote sensing into GIS, information systems considerable richer and more sophisticated can be created for use in substantive applications.
The fact is that application indicated technology for collection necessary data during execution and decision making of engineering solutions. An advantage of use of space technology is an excellent instrument of merging and integration accessed data into geographical coordination stimulated of easily those definition and importance in all the stage of engineering executions.
Impacts of Wastewater Irrigation on Growth, Yield and Salts Uptake of Barley
Authors: Haddad Marwan , Namrotee Zakiyeh S. , Shtaya Munqez
Published: January 2023

Treated wastewater is promising water resource as alternative or supplementary source for fresh water to be used in agriculture specially for areas of water shortage and crops with good potential of tolerating saline water. In this study long-term irrigation with fresh and wastewater on growth and yield of seven non-local cultivars (S42IL107, BW284, BW281, G400, Scarlett, Bowman and BW290) of Barley (Hordeum vulgare L.) showed that (1) barley cultivars irrigated with both fresh and wastewater had in general the same growth vigor and growth nature, (2) The cultivars irrigated with wastewater gave nearly twice the yield of that irrigated with freshwater. BW290 cultivar showed the best and highest yield among the seven cultivars while S42IL107 had the weakest prostrate growth, (3) The use of wastewater in irrigation increased the nitrogen (N), Phosphorous (P) and potassium (K) contents in soil profiles affecting its texture, (4) barley proved to be a salt-tolerant crop with considerable economic importance, Barley could tolerate saline water until (5µs) without any shortage in the yield of the crop, and (5) barley irrigated with both wastewater and freshwater needed nearly the same time to emergence, stem elongation, flowering and maturity and consequently, wastewater irrigation of barley is a promising water resource as alternatives for fresh water.
Water and Soil Quality in the Vicinity of a Vegetable Oil Producing Company and a Poultry Hatchery
Authors: Mauluka M. M. , Mmangisa G. , Mumba P. , Moyo B.
Published: January 2023

In the vicinity of two factories, one a vegetable oil company and a poultry hatchery lives a farming community. The crops in the community’s fields have either not been germinating or dying before reaching maturity. A study was therefore conducted to assess the quality of effluent discharged into a stream, water in the stream and in the soil in the surrounding fields. Both the effluent and the water at selected points in the stream were analyzed for some parameters in the dry and rainy seasons. In the soil, pH, phosphorus, organic matter, soil respiration, electrical conductivity and nitrogen were analyzed only in the dry season. The results showed that the effluent and the water at all points sampled were slightly acidic in both the dry season and wet season. The dissolved oxygen was low in dry season but was relatively high in rainy season. The electrical conductivity and total dissolved solids had high concentrations in both seasons. Phosphate was high in the effluent in both seasons. The water upstream had higher levels of dissolved oxygen than at all points down the stream in both seasons. Oil was higher in dry season (p
Predicting Case Fatality of Dengue Epidemic: Statistical Machine Learning Towards a Virtual Doctor
Authors: Chattopadhyay S. , Chattopadhyay A.K. , Aifantis E.C.
Published: January 2023

Dengue fever is a self-limiting communicable viral disease, transmitted through mosquito bites. Its Case Fatality Grade (CFG) varies across population due to variations in viral load, immunity of the patient, early diagnosis, and availability of high-end treatment facility. This study describes an initial effort to automate the process of Dengue CFG predictions. Two established Statistical Machine Learning (SML) algorithms, Multiple Linear Regressions (MLR) and Multinomial Logistic Regressions (MnLR), are combined to substitute the existing Deep Learning methods for clinical decision making. We consider a vector of eleven sign-symptoms (independent variables), each weighted between [0,1] on a 3-point scale - ‘Mild’ (CFG<=0.33), ‘Moderate’ (0.33<CFG< 0.66), and ‘Severe’ (CFG>0.66). Results show that both classifiers are effective in early screening with similar accuracy levels (68% for MLR versus 72% for MnLR) although precision levels are far superior with MnLR (88%) than MLR (61%). This study is a futuristic step towards Machine Learning (ML) aided clinical diagnostic paradigms, as an alternative to computationally intensive Artificial Intelligence.
Adult T-Cell Leukemia and Retinoid
Authors: Maeda Yasuhiro , Okamoto Atsushi , Kawaguchi Shin-ichiro , Konishi Akiko , Yamamoto Kenta , Eguchi Go , Yamaguchi Terufumi
Published: January 2023

Adult T-cell leukemia/lymphoma (ATL/ATLL) is an aggressive lymphoid disease caused by human T-cell leukemia virus type 1 (HTLV-1). It is reported that retinoid suppressed the proliferation of malignant cells including ATL cells. In this study, we showed the mechanism of retinoid action for ATL cells. We observed that NF-kB transcriptional activity as well as cell proliferation decreased in HTLV-1-positive T-cell lines by treatment with retinoid. Further, we observed that retinoid reduced HTLV-1 proviral DNA. Interestingly, retinoid significantly inhibited reverse transcriptase (RT) activity similar to azidothimidine (AZT) on HTLV-1-positive T-cell lines. Therefore, AZT was inhibitory of proviral DNA load but not NF-kB transcriptional activity on HTLV-I, however retinoid was inhibitory of both NF-?B and proviral DNA on HTLV-1. Furthermore, we showed cellular senescence in HTLV-I positive T-cell lines and in primary ATL cells obtained from acute ATL patients. The number of senescent cells significantly increased in the HTLV-I positive T-cell lines after treatment with retinoid, but not in the HTLV-I negative ones. These results indicated that retinoid could have three roles, as a NF-?B inhibitor, as a RT inhibitor and as a facilitating cellular senescence.
Growth Factors in the Platelet-Rich Plasma
Authors: Gonzalez Maczy , Arteaga-Vizcaino Melvis , Ruiz Ana , Estevez Jesus , Quintero Jesus , Quintero Maribel , Briceño Olga , Atencio Ricardo , Marcano Ivis
Published: January 2023

PRP is an useful bioproduct to tisular regeneration. The aim of study was evaluate the concentration of growth factors: PDGFBB (platelet-derived growth factor), EGF(epidermal growth factor) and VEGF (vascular endothelial growth factor) present in the Platelet-rich plasma (PRP) in subjects treated with drugs which inhibit platelet aggregation as acetylsalicylic acid (ASA) and clopidogrel before and after administration. We determined by ELISA PDGFBB, EGF and VEGF levels in PRP, Platelet Poor Plasma (PPP), lysate and exudate from 32 healthy subjects before and 24 hours after ingesting acid Acetyl salicylic acid (ASA) and clopidogrel as a single dose. The PRP and PPP were obtained by the method of Anitua by single centrifugation method. To analyze the results of student test and Pearson correlation was applied, with statistical significance level of p < 0.05. PPP and exudate (Clopidogrel: p < 0.001), PRP (Clopidogrel: p < 0.01) statistically significant differences for PDGFBB in PPP (p < 0.01 AAS) were found, and for VEGF in lysate (ASA and Clopidogrel: p < 0.05). No significant difference was found for EGF. Only was no correlation between baseline values of EGF in the ASA group and the respective PRP platelet count (r = 0.726). The results show that the average basal values of the three growth factors measured were considered particularly high in the PRP and lysate, showing the significant decrease for PDGFBB after antiplatelet therapy, especially of Clopidogrel and a significant increase for the VEGF only for the lysate. Although the behavior of three different soluble mediators was different to antiplatelet agents, the observed changes support the conclusion that a single dose of these drugs not markedly affect the secretion and availability of the three growth factors measured in various platelet derived obtained.
Acute Hepatitis B Progression to Chronicity - A Prospective Study at Tertiary Care Centre of Northeren India
Authors: Malhotra Parveen , Malhotra Vani , Sanwariya Yogesh , Pahuja Isha , Chugh Ajay , Akshay
Published: January 2023

Background: There are limited number of studies providing information regarding the progression of acute hepatitis B virus (HBV) infection to chronic phase.
Aim: To determine the percentage of patients of acute hepatitis B who progressed to chronic hepatitis B stage.
Methods: It was a prospective study over a period of four years in which total 409 confirmed acute hepatitis B patients were enrolled but out of them only three hundred and four, (221 men and 83 women, 06–82 years old) were followed regularly for at least six months or more, thus data pertaining to them was analyzed.
Results: Out of total of 304 acute hepatitis B patients, 279 patients resolved and became Hepatitis B surface antigen (HbsAg) and Hepatitis B virus DNA negative whereas 25 patients went into chronic phase. No differences were found between groups with respect to age and sex. However, Serum Bilirubin, Serum amino transaminases, HbeAg and HBV DNA Quantitative levels were significantly lower in patients who progressed to chronic hepatitis stage.
Conclusions: Around 91.78% of acute hepatitis B patients resolved but 8.22% progressed to Chronic hepatitis B stage The twenty five patients who progressed to chronic infection had mild hepatitis on comparison to 279 patients who resolved, thus suggesting that patients with mild acute hepatitis B infection may have a higher risk of progressing to chronic infection.
Theta Frequency is Associated to Morpho-Strcutural and Perfusional Modifications in Subjects with Mild Cognitive Impairment
Authors: Moretti D.V. , Paternicò D. , Prestia A. , Binetti G. , Zanetti O. , Frisoni G.B.
Published: January 2023

Background: In an attempt to find non-invasive biomarkers, researchers have investigated the feasibility of neuroimaging tools, such as MR, SPECT as well as neurophysiological measurements using EEG. The increase of theta frequency has been associated with mild cognitive impairment (MCI) and related to both grey matter (GM) changes of thalamus and basal ganglia and SPECT modifications. Objective: To study the association of prognostic theta frequency with specific GM and perfusional changes of thalamus and basal ganglia to detect biomarkers early predictive of mild cognitive impairment. Methods: 74 adult subjects with mild cognitive impairment underwent EEG recording and high resolution 3D magnetic resonance imaging (MRI). Moreover, 27 adult subjects with mild cognitive impairment underwent also perfusion single-photon emission computed tomography (SPECT) evaluation. The theta/gamma ratio was computed for each subject. Three groups were obtained according to increasing tertiles values of theta/gamma ratio. Grey matter density differences between groups were investigated using a Voxel Based Morphometry technique. Results: Subjects with higher theta/gamma ratio and increase of theta frequency showed minor atrophy in putamina nuclei bilaterally and a lower hippocampal perfusion in subjects with mild cognitive impairment. Conclusion: The integrated analysis of EEG and morpho-functional markers could be useful in the comprehension of anatomo-physiological underpinning of the MCI entity.
The Integration of Quantum Physics in the Transformation of Consciousness in Individuals, Couples and Organizations
Authors: Gregory Bruce , Gregory Birgitta
Published: January 2023

This paper explores the role of the dynamics and principles of quantum physics in the transformation of consciousness. Quantum entanglement, momentum, the uncertainty principle, Dirac’s creation and destruction operators, and the role of opposites are discussed in the contexts of the implied directive, group theory, and the transformation of resistance with individuals, couples, and organizations. The appreciation of novelty, the role of focusing attention, and the needs for depth and containment are explored in the context of recent developments of neuroscience. These developments are explored in the context of applications from set and group theory. Erickson’s resistance protocol is utilized as both a template and metaphor for the role of the consciousness of the professional and the integration of quantum principles and dynamics in the transformation of consciousness.
The Reliability and Validity of the Levels of Emotional Awareness Scale for Children (LEAS-C) in Chinese Children
Authors: Zhang Pengcheng , Wang Zhe , Shen Yongjiang , Wang Haibin
Published: January 2023

Objective: To revise and explore the application of the Levels of Emotional Awareness Scale for Children (LEAS-C) in Chinese Children. Methods: 417 Primary school students from grade four and five were surveyed by the Chinese version of the Levels of Emotional Awareness Scale for Children (LEAS-C) and the Questionnaire on Youth’s Emotional Intelligence (QYEI). Results: (1) The LEAS-C contained self and other two dimensions, and the intra-class correlation coefficient of the overall scale and two subscales were more 0.88 and 0.89 respectively, the Cronbach’s alpha coefficient of full and two subscales were more 0.90, 0.89, and 0.88 respectively, the split-half reliability of the overall scale and two subscales were 0.86, 0.82, and 0.83 respectively; (2) the correlation between two subscales of LEAS-C was 0.87, and the correlation between the total scores and the two subscales were 0.93 and 0.95 respectively; (3) significant positive correlations were found between LEAS-C and QYEI; and (4) the scores of females were higher than those of male on self-, other- and total-LEAS-C scores. Conclusion: The Levels of Emotional Awareness Scale for Children (LEAS-C) has good reliability and validity and can be used in Chinese Children.
Prevalence of Depression and Clinical Anxiety in Patients with Cardiovascular Disease
Authors: Martino Pablo Luis , Mora-Penagos Juan Pablo , Kerbage Soraya , Cervigni Mauricio Alejandro , Bonet José Luis
Published: January 2023

Depression and Clinical Anxiety predict a worse prognosis for Cardiovascular Disease (CVD). Recent studies warn of high rates of clinical depression and anxiety in patients with CVD. The reported percentages range over a wide range. In order to provide new data on the prevalence of Depression and Clinical Anxiety in CVD, the psychological state of 70 Argentine adults attending a Cardiovascular Rehabilitation Program was surveyed. Two psychological scales were administered: the Beck Anxiety Inventory and the Beck Depression Inventory II. It was observed a 17.1% of participants with probable Major Depressive Disorder and a 27.1% with probable Clinical Anxiety. The results of the current study are in accordance with the percentages reported by previous studies. A significant number of patients presented comorbidity between Clinical Depression and Anxiety. No differences were found by gender. It is recommended that health professionals take into consideration the high prevalence of Clinical Depression and Anxiety in patients with CVD.
A Facile One-pot Process for the Synthesis of Stiripentol
Authors: Sudrik Vilas , Bodkhe Arjun , Karpe Dnyaneshwar , Lawande Shamrao
Published: January 2023

A facile one-pot synthesis of Stiripentol (STP) 1 in which Initially 3, 4-dihydroxy benzaldehyde 13 is treated with methylene diiodide using base KOH to get 2 which undergoes in situ Knoevenagel condensation with 3,3-dimethyl 2-butanone using catalytic Phase Transfer Catalyst i.e. Tetrabutylammonium bromide (TBAB) and K2CO3 to get 4 which undergo Regioselective Luche reduction of α-β unsaturated ketone with NaBH4 and Cerium (III) chloride (CeCl3) to get pure Stiripentol 1 which is commercially viable and eco-friendly.
Sonochemical Synthesis, Characterization and Molecular Docking of Thiazole and Triazole Tethered Tetra-Substituted Imidazoles.
Authors: Pandey Himanshu , Kumar Kaushal , Mishra Neha , Yadav Ritu , Shrivastava S. P.
Published: January 2023

Sonochemical synthesis of tetra-substituted imidazole derivatives tethered with thiazole and triazole moieties carried out by condensation reaction, involving aldehyde, benzil, ammonium acetate and selected amino azole moiety with brick clay as catalyst. The synthesized tetra-substituted imidazole derivatives were characterized using FT-IR, NMR spectroscopy. Molecular docking studies of the synthesized tetra-substituted imidazole derivatives for their antimicrobial potency were also performed. These derivatives scored satisfactorily and can be the possible lead for the future drug candidate against microbial pathogens
Assessment of Micro-plastics in Domestic Sewage Water Treatment Plants in India
Authors: Kumar P. , Gupta P.
Published: January 2023

The removal quantity of MPs is investigated in seven STPs in Rewari district, Haryana. An increased sampling approach incorporating a magnetic force flow meter and a quick photographic camera was used to capture twenty-one samples. The concentration of incoming MPs is 1.56-13.69 items/L, and the effluent concentration is 0.20-1.73 items/L, showing that 79.49-97.81% of the MPs are eliminated, the seven STPs are foreseen to unharness 6.5-108 MPs into the treated effluent every day. Plastic polymers structure 62.68 % of the particles, consistent with lightweight microscopic and micro-Raman qualitative analysis, with polystyrene (10.3 per cent), plastic (30.2 per cent), propylene polymer or ethylene polymer (26.9 per cent), polyethene terephthalate (7.5 per cent), and synthetic resin (21.9 per cent) in influent. White (30.4 per cent) and clear make up the bulk of MPs' appearance (19.9 per cent) in the effluent. Pellets (5.6%), fibres (30.4%), fragments (28.0%), and granules (36.0%) are the top typical MP shapes, according to our findings in the effluent.
Geochemical study of the Tongshan intrusion in the Lower Yangtze River metallogenic belt, China: Significances of Cu-Au ore-forming
Authors: Gu Huangling
Published: January 2023

The Tongshan intrusion is located at the Guichi ore cluster field along the Lower Yangtze River metallogenic belt (LYRB) in eastern China. Elemental data and major elements of biotite are reported for Late Mesozoic plutons in the Guichi ore cluster in the Middle-Lower Yangtze River Region, attempting to explain their diagenetic age, petrogenesis, and tectonic implications. The Tongshan intrusion is dated at 146.3±3.2 Ma, with zircon εHf(t) average value of -5.23, illustrating that the Tongshan intrusion could be derived from crust mantle mixing magmatite provenance. The two-stage Hf model ages between 1184~1422 Ma is indicated magma source relationship with those of the Mesoproterozoic basement in south Anhui. The Tongshan intrusion is high-K calc-alkaline, and exhibit adakite-like geochemical feature, such as high Al2O3, Sr contents, Sr/Y value, low Y and Yb contents. The geochemical and reexplained published isotopic data indicate that these adakites are most likely from partial melting of subducted oceanic crust, and mixed with enriched lithospheric mantle components in the rising process.
Geotechnical performance of combined stone columns and piles capped with reinforced concrete raft foundation in soft clay soil
Authors: Ahmed Danish
Published: January 2023

Stone columns consist of granular material compacted in long cylindrical holes. They are used for improving the strength and consolidation characteristics of compressible soils. However, they are still less effective at supporting heavy loads, since they still cannot transfer applied stresses to deeper layers of soil. The main objective of this numerical study was to investigate the geotechnical performance of a combined foundation system composed of stone columns and piles grouped together under a rigid raft foundation in compressible soil. The failure mechanism of this hybrid foundation system was examined, and configurations optimizing the performance of the combined foundation system were explored. An analytical model was developed for predicting the ultimate carrying capacity of the combined system in compressible soils. It was deduced that combining stone columns and piles in one foundation system improved considerably the system’s carrying capacity. Moreover, the uppermost improvement was observed when the piles were installed on the periphery or edge of the raft foundation, while stones columns were placed at the center area of the raft. The failure of the combined foundation system started from the center of the raft and noticeably extended to its edges. Due to the presence of stone columns in the combined foundation system, the piles did not interact. The areas affected or influenced by the soil–pile interaction also did not overlap.
Improving the upper atmospheric temperature accuracy of the ground-based instrument by eliminating noise ways
Authors: Xue Yangyang , Li Cunxia , Hui Ningju , Liu Lina , Tong Junyi , Zhang Rong , Tang Yuanhe
Published: January 2023

In view of the special properties of the upper atmosphere at the altitude of
80–120 km, a ground-based passive remote sensing instrument
ground-based airglow volume emission rate and temperature imaging
interferometer (GBAVTII) is built to detect the atmospheric
temperature used

O

2

(

0
-
1

)

spectral line of night airglow at the
altitude of 94 km. In the process of photographing the upper
atmosphere airglow with the GBAVTII, the stray light (white noise)
such as moonlight, city lights, and starlight will be affected. In
this paper, the theoretical expression of denoising is derived based
on the rotational line temperature measurement of diatomic

O

2

(

0
-
1

)

airglow. Through a slight adjustment
of different parameters in the forward equation of the GBAVTII and
noise reduction in laboratory flat-field fine calibration, and other
denoising methods in the GBAVTII image processing process, the maximum
accuracy of the GBAVTII detection of the upper atmospheric temperature
is enhanced to 2.4 K. Also, the minimum error of the GBAVTII
detecting data with the satellite instrument sounding of atmosphere
using broadband emission radiometry is 0.4 K. Thus, the
absolute accuracy of the GBAVTII in detecting the upper atmospheric
temperature can be improved to

±

(

0.4
−

2.4

)

K

through the theory and method studied
in this paper.
Single LED visible light positioning system based on image sensor and calculated azimuth angle
Authors: Wang Tongyao , Lin Zuojun , Cheng Han , Xiao Chunxian
Published: January 2023

A single-lamp visible light positioning (VLP) system based on an optical camera is proposed and demonstrated. The system uses a circular light-emitting diode (LED) to transmit ID data, and a common smartphone camera for positioning. First, we propose a scheme to calculate the azimuth angle using a marked lamp bead, avoiding the use of a magnetometer, which can improve the accuracy of the azimuth angle. Second, we propose a new positioning method using a chord in the image plane, which passes through the midpoints of two chords parallel to the LED plane. The experimental results show that when the experimental area is

1.8

m

×
3.6

m

, the three-dimensional (3D) average positioning errors are 8.0, 7.5, and 7.2 cm for the heights of 1.75, 1.45, and 1.2 m.
Exhibition of a film’s resonances in ellipsometric spectra and the Berreman effect
Authors: Bortchagovsky Eugene , Mishakova Tetiana
Published: January 2023

Ellipsometry is a powerful and sensitive optical method for the investigation of surfaces and thin films. However, the absence of possibilities for direct interpretation of the ellipsometric spectra creates an impression of the complexity of this method and the difficulty in its application, so any approach for qualitative interpretation of the ellipsometric spectra is very desirable. This work is devoted to this problem with the example of the modulation of the ellipsometric spectra of a substrate by the resonances of a thin deposited film.
Absolute phase measurement method based on bidirectional coding patterns
Authors: Qi Xingyang , Zhou Canlin , Wang Yixiao , Li Hui
Published: January 2023

The stair-phase-coding patterns have been widely used to determine the fringe order for phase unwrapping of the wrapped phase in three-dimensional shape measurement. Although the special coding sequence algorithm can achieve with a large number of codewords, it needs the current codeword and its adjacent codewords to jointly determine the fringe order. If any codeword of the grouped adjacent codewords is incorrectly recognized, it will result in many false fringe orders. It increases the probability of fringe order error in the decoding process. And it is challenging to significantly increase the number of codewords. To solve this problem, we propose an absolute phase measurement method based on bidirectional coding patterns. The wrapped phase of the object is obtained by four-step phase-shifting patterns, and the fringe order is obtained by bidirectional coding patterns. When generating the bidirectional coding patterns, we code two groups of stair phase with different frequencies along the horizontal direction, which respectively represent local fringe order and partition information. Then, we alternately repeat the two groups of stair phase along the vertical direction in the whole pattern to obtain the bidirectional coding patterns. Each local fringe order information and the corresponding partition information in a small region jointly determine the fringe order of pixels in this small region. Fringe order errors in a small region do not affect other regions. To verify the effectiveness of our method, we performed simulations and experiments. Simulation and experimental results show that our method is effective for objects with different sizes and isolated objects.
Sandwich structure magnetometer with a high sensitivity and signal-to-noise ratio based on an ultrahigh-Q CaF2 resonator
Authors: Bai Jiamin , Rong Jiamin , Xing Enbo , Ji Ruipu , Yue Jun , Li Li , Liu Wenyao , Zhou Yanru , Tang Jun , Liu Jun
Published: January 2023

Whispering gallery mode (WGM)
resonators with an ultrahigh quality (

Q

) factor provide an extremely high
resolution for high-precision sensing. However, it is difficult to use
them directly in magnetic sensors because of the transparency to the
magnetic field. In this paper, a sandwich structure consisting of a
neodymium iron boron magnet and calcium fluoride resonator with a

Q

factor of

10

9

is proposed. The experimental results
show that, compared with the conventional magnetometer, the
signal-to-noise ratio of the optical WGM magnetometer reaches
62 dB, with the direct current sensitivity of
42.59 MHz/mT and the AC sensitivity of

794

p
T

H
z

−
1

/

2

at 42 kHz.
Metastability of photonic spin meron lattices in the presence of perturbed spin-orbit coupling
Authors: Lei Xinrui , Du Luping , Yuan Xiaocong , Zhan Qiwen
Published: January 2023

Photonic skyrmions and merons are topological quasiparticles characterized by nontrivial electromagnetic textures, which have received increasing research attention recently, providing novel degree of freedom to manipulate light-matter interactions and exhibiting excellent potential in deep-subwavelength imaging and nanometrology. Here, the topological stability of photonic spin meron lattices, which indicates the invariance of skyrmion number and robustness of spin texture under a continuous deformation of the field configuration, is demonstrated by inducing a perturbation to break the C4 symmetry in the presence spin-orbit coupling in an optical field. We revealed that amplitude perturbation would result in an amplitude-dependent shift of spin center, while phase perturbation leads to the deformation of domain walls, manifesting the metastability of photonic meron. Such spin topology is verified through the interference of plasmonic vortices with a broken rotational symmetry. The results provide new insights on optical topological quasiparticles, which may pave the way towards applications in topological photonics, optical information storage and transfer.
Radiometric cross-calibration of Sentinel-2B MSI with HY-1C SCS based on the near simultaneous imaging of common ground targets
Authors: Xu Heyu , Huang Wenxin , Si Xiaolong , Song Qingjun , Li Xin , Weiwei Xu , Ma Yue , Zhang Liming
Published: January 2023

To simplify the cross-calibration process and improve calibration frequency and accuracy, this paper proposes a cross-calibration method for the multispectral remote sensor Multi-Spectral Instrument (MSI) carried by Sentinel-2B using the hyperspectral remote sensor, that is, the satellite calibration spectrometer (SCS) carried by Hai Yang (HY)-1C, as the reference sensor and establishes the calibration process. Precise spectral response matching between SCS and MSI spectral channels is performed by the interpolation and iteration of hyperspectral data to eliminate the difference in band settings and significantly improve the accuracy of cross-calibration coefficients. The SNO-x inherited from the simultaneous nadir overpass (SNO) method is used as a prediction method to carry out cross-calibration imaging in mid- and low-latitude regions, which improves the cross-calibration frequency and broadens the dynamic range of calibration. The cross-calibration coefficients and offsets of MSI B1∼B7 and B8a were obtained by processing the earth observation images of the MSI and SCS on January 24, 2019. Then, the cross-calibration coefficients and offsets are applied to the ocean, farmland and other ground objects with different reflectance, and the reliability and accuracy of the cross-calibration results are evaluated with the Moderate-resolution Imaging Spectroradiometer (MODIS) carried by Terra as a reference. To improve the accuracy of the evaluation, the spectral band adjustment factor between the corresponding channels of MSI and MODIS is used to correct the measured reflectance of MODIS based on the satellite calibration coefficient. The reflectance directly obtained by processing the MSI image is used as the MSI-measured reflectance, the reflectance obtained based on the cross-calibration coefficient is used as the MSI-calculated reflectance, and the reflectance corrected by the spectral band adjustment factor (SBAF) is used as the MODIS-calculated reflectance. The results show that the mean root-mean-square relative error (RMSRE) between the MODIS-calculated reflectance and the MSI-calculated reflectance is 2.16% and that the mean RMSRE between the MODIS-calculated reflectance and the MSI-measured reflectance is 3.05%, indicating that the reflectance corrected based on calibration coefficients is closer to the MODIS-calculated reflectance. Finally, each uncertainty source in the cross-calibration is analyzed, and the comprehensive uncertainty is found to be 4.03%, indicating that SCS can be used as a reference for MSI cross-calibration.
High-resolution molecular fingerprinting in the 11.6–15 µm range by a quasi-CW difference-frequency-generation laser source
Authors: Elkhazraji Ali , Shakfa Mohammad Khaled , Lamperti Marco , Hakimov Khaiyom , Djebbi Khalil , Gotti Riccardo , Gatti Davide , Marangoni Marco , Farooq Aamir
Published: January 2023

We report an approach for high-resolution spectroscopy using a widely tunable laser emitting in the molecular fingerprint region. The laser is based on difference-frequency generation (DFG) in a nonlinear orientation-patterned GaAs crystal. The signal laser, a CO2 gas laser, is operated in a kHz-pulsed mode while the pump laser, an external-cavity quantum cascade laser, is finely mode-hop-free tuned. The idler radiation covers a spectral range of ∼11.6–15 µm with a laser linewidth of ∼ 2.3 MHz. We showcase the versatility and the potential for molecular fingerprinting of the developed DFG laser source by resolving the absorption features of a mixture of several species in the long-wavelength mid-infrared. Furthermore, exploiting the wide tunability and resolution of the spectrometer, we resolve the broadband absorption spectrum of ethylene (C2H4) over ∼13–14.2 µm and quantify the self-broadening coefficients of some selected spectral lines.
Graphene-based Pancharatnam-Berry phase metasurface in the terahertz domain for dynamically independent amplitude and phase manipulation
Authors: Wu Xiaodong , Cao Hailin , Peng Junhui , Meng Zhenya
Published: January 2023

Dynamic and independent amplitude and phase manipulation are the paramount demand for many advanced wavefronts engineering applications. Currently, the coupling issue between the amplitude and phase hinders the efficient modulation wavefront’s further implementation. This paper proposes and numerically demonstrates the bi-layer stacked graphene Pancharatnam–Berry (P–B) phase metasurface and mono-layer graphene P-B phase metasurface to address the above problem. The simulation results show that the proposed models can achieve the independent control amplitude and phase and significantly reduce their coupling strength. Our findings offer a flexible and straightforward method for precise wave reconstruction applications such as holography, optical tweezers, and high-resolution imaging.
Efficient second-harmonic generation through cascaded optically poled fibers
Authors: Gemechu Wasyhun Asefa , Minoni Umberto , Modotto Daniele , Tonello Alessandro , Couderc Vincent
Published: January 2023

We report the experimental demonstration of efficient second-harmonic generation by splicing optically poled fiber segments. A device made from five segments each 20 cm-long exhibits, at a fundamental average power of 4.2 mW, a maximum increase of 5.5 in the conversion efficiency with respect to a single 20 cm poled fiber, corresponding to a conversion efficiency of 5.4%. For any considered fundamental power, the conversion efficiency at the output of a five-segment device is larger than the efficiency of a single poled fiber having the same length.
1.2-kW all-fiber Yb-doped multicore fiber amplifier
Authors: Ortega Luis F. , Feigenson Thomas , Tam Yin Wan , Reeves-Hall Peter , Fan Tso Yee , Messerly Michael , Yu Charles X. , Hong Kyung-Han
Published: January 2023

We have demonstrated a record-high 1.2 kW, all-fiber multicore amplifier using a six-core single-mode Yb-doped fiber and a multicore pump-signal combiner (PSC). The output power is limited by the pump power of 1.9 kW. We have developed double-clad six-core fibers and PSCs for this demonstration. Each of the six Yb-doped cores has a 17-µm mode-field diameter (MFD) with a trench index profile and is capable of kW-class operation. The potential power scaling to the 10-kW level in a single amplifier with high brightness should be feasible with advanced thermal management and coherent beam combination.
Tuning magneto-electric coherent resonance with a deep-subwavelength localized spoof surface plasmonic structure
Authors: Liu Liangliang , Shen Jinrui , Li Zhuo
Published: January 2023

It has been recently shown that an ultrathin corrugated spiral metal strip can simultaneously support electric and magnetic localized spoof plasmonic modes at lower frequencies. In this Letter, we report a mirror quasi-symmetrical corrugated spiral metal disk which can support coherent resonance of an orthogonal electric dipole and a magnetic dipole to achieve azimuthally symmetric unidirectional scattering. By tuning the geometric dimensions, reconfigurable magneto-electric (ME) coherent resonance enhancement is realized. Excellent agreement between numerical simulations and experimental results verifies the tunable ME coherent resonance phenomenon. Our finding could anticipate future sensitive and versatile functional devices based on high-Q coherent resonance from the microwave to the terahertz bands.
Programmable, high-speed, adaptive optics partially confocal multi-spot ophthalmoscope using a digital micromirror device
Authors: Lee Soohyun , Choi Stacey S. , Meleppat Ratheesh K. , Zawadzki Robert J. , Doble Nathan
Published: January 2023

A high-speed, adaptive optics partially confocal multi-spot ophthalmoscope (AO-pcMSO) using a digital micromirror device (DMD) in the illumination channel and a fast 2D CMOS camera is described. The camera is synchronized with the DMD allowing projection of multiple, simultaneous AO-corrected spots onto the human retina. Spatial filtering on each raw retinal image before reconstruction works as an array virtual pinholes. A frame acquisition rate of 250 fps is achieved by applying this parallel projection scheme. The contrast improves by 2–3 fold when compared to a standard flood illumination architecture. Partially confocal images of the human retina show cone and rod photoreceptors over a range of retinal eccentricities.
Subwavelength structure engineered passband filter for the 2-µm wave band
Authors: He Wenchang , Sun Yuhan , Zhou Peiji , Xia Lipeng , Li Ting , Yi Qiyuan , Shen Li , Cheng Zhenzhou , Zou Yi
Published: January 2023

In this work, we experimentally demonstrate a passband filter for the 2-µm wave band on the silicon-on-insulator platform. The device consists of a strip waveguide and an apodized subwavelength-structured waveguide. Fabricated on a 340-nm-thick silicon membrane, the proposed passband filter shows a 3-dB bandwidth of 16–33 nm, a high sidelobe suppression ratio (SLSR) of 24 dB, and a low insertion loss (IL) of 0.4 dB.
Phase space nonclassicality and sub-Poissonianity of deformed photon-added nonlinear cat states: algebraic and group theoretical approach
Authors: Torkzadeh-Tabrizi Sogand , Faghihi Mohammad Javad , Honarasa Gholamreza
Published: January 2023

In this Letter, we introduce four distinct classes of f-deformed photon-added nonlinear cat state. This would be achieved by recalling a nonlinear coherent states approach, as well as a particular class of Gilmore–Perelomov-type of SU(1,1) coherent state and a class of SU(2) coherent state. We then examine the role of photon addition and nonlinearity functions in the phase space structure and sub-Poissonianity of even, odd, and Yurke–Stoler nonlinear cat states. The effect of photon addition, which results in a π phase shift at the origin of the Wigner function toward negativity, interestingly enhances the nonclassicality by means of the Wigner function and Mandel parameter. Furthermore, owing to photon addition, we can observe a deformation in the Gaussian shape of the Wigner function, which may be found to be potentially useful in quantum noise reduction. Moreover, the deformation function shows a remarkable role in revealing the nonclassical behavior and can increase the depth and the domain of nonclassicality.
Unified statistical thermocline channel model for underwater wireless optical communication
Authors: Qiu Hongcheng , Huang Zhitong , Xu Jie , Zhai Wenmin , Gao Yi , Ji Yuefeng
Published: January 2023

Understanding the effect of ocean turbulence on optical beam propagation is critical to the design and performance evaluation of underwater wireless optical communication systems. In this Letter, we propose a unified Weibull–generalized gamma distribution to characterize the laser beam irradiance fluctuations of turbulent underwater thermocline wireless optical channels. The proposed model shows an excellent agreement with the measured data under various experimental emulated channel conditions that cover turbulences induced by temperature, salinity, and air bubbles. To the best of our knowledge, this is the first model that comprehensively describes the statistics of the laser beam irradiance fluctuations in underwater wireless optical channels due to both thermohaline gradient and air bubbles.
High-efficiency interface between multi-mode and single-mode fibers
Authors: Korichi Oussama , Hiekkamäki Markus , Fickler Robert
Published: January 2023

Multi-mode fibers (MMFs) and single-mode fibers (SMFs) are widely used in optical communication networks. MMFs are the practical choice in terms of cost in applications that require short distances. Beyond that, SMFs are necessary because of the modal dispersion in MMFs. Here, we present a method capable of interfacing an MMF with an SMF using a re-programmable multi-plane light conversion scheme (MPLC). We demonstrate that only three phase modulations are necessary to achieve MMF–SMF coupling efficiencies from 30% to 70%, i.e., an insertion loss from 5 dB to 1.5 dB, for MMFs with core diameters up to 200

μ

m. We show how the obtained coupling efficiency can be recovered if the output field of the MMF changes entirely, e.g., through strong deformation of the fiber, by simple monitoring of the field. Furthermore, we test the influence of the resolution of both essential devices (field reconstruction and MPLC) on coupling efficiencies. We find that commercially available devices with increased speed and efficiency, such as wavefront sensors and deformable mirrors, are sufficient for establishing an MMF–SMF interface that auto-corrects any decoupling in the kilohertz regime.
TailCoR: A new and simple metric for tail correlations that disentangles the linear and nonlinear dependencies that cause extreme co-movements
Authors: Babić Sladana , Ley Christophe , Ricci Lorenzo , Veredas David
Published: January 2023

Economic and financial crises are characterised by unusually large events. These tail events co-move because of linear and/or nonlinear dependencies. We introduce TailCoR, a metric that combines (and disentangles) these linear and non-linear dependencies. TailCoR between two variables is based on the tail inter quantile range of a simple projection. It is dimension-free, and, unlike competing metrics, it performs well in small samples and no optimisations are needed. Indeed, TailCoR requires a few lines of coding and it is very fast. A Monte Carlo analysis confirms the goodness of the metric, which is illustrated on a sample of 21 daily financial market indexes across the globe and for 20 years. The estimated TailCoRs are in line with the financial and economic events, such as the 2008 great financial crisis and the 2020 pandemic.