bluuebunny/crossref_metadata_2025 huggingface dataset:
How to make giant planets via pebble accretion
Authors: Savvidou Sofia , Bitsch Bertram
Published: September 2023

Planet formation is directly linked to the birthing environment that protoplanetary disks provide. The disk properties determine whether a giant planet will form and how it evolves. The number of exoplanet and disk observations is consistently rising, however, it is not yet possible to directly link these two populations. Therefore, a deep theoretical understanding of how planets form is crucial. Giant planets are not the most common exoplanets, but their presence in a disk can have significant consequences for the evolution of the disk itself and the planetary system undergoing formation. Their presence also offers more chances of spotting observational features in the disk structure. We performed numerical simulations of planet formation via pebble and gas accretion, while including migration, in a viscously evolving protoplanetary disk, with dust growing, drifting, and evaporating at the ice lines. In our investigation of the most favorable conditions for giant planet formation, we find that these are high disk masses, early formation, and a large enough disk to host a long-lasting pebble flux, so that efficient core growth can take place before the pebble flux decays over time. Specifically, core growth needs to start before 0.9 Myr to form a giant, with an initial disk mass of 0.04 M⊙ (or higher) and the disk radius needs to be larger than 50 AU. However, small disks with the same mass allow more efficient gas accretion onto already formed planetary cores, leading to more massive gas giants. Given the right conditions, high viscosity (α = 10−3) leads to more massive cores (compared to α = 10−4) and it also enhances gas accretion. At the same time, it causes faster type II migration rates, so the giants have a decreasing final position for increasing viscosity. Intermediate dust fragmentation velocities, between 4 and 7 m s−1, provide the necessary pebble sizes and radial drift velocities for maximized pebble accretion with optimal pebble flux. The starting location of a planetary embryo defines whether a giant planet will form, with the highest fraction of giants originating between 5 and 25 AU. Finally, a dust-to-gas ratio of 0.03 can compensate for lower disk masses with fDG ≤ 0.015, but early formation is still important in order to form giant planets. We conclude that there is no specific initial parameter that leads to giant planet formation; rather, it is the outcome of a combination of complementary factors. This also implies that the diversity of the exoplanet systems is the product of the intrinsic diversity of the protoplanetary disks and it is crucial to take advantage of the increasing number and quality of observations to constrain the disk population properties and ultimately devise planet formation theories.
An In Vitro Method to Quantitate Gaseous Microemboli Production of Bubble Oxygenators
Authors: Sakauye L. M. , Servas F. M. , O’Connor K. B. , Cottonaro C.
Published: September 2023

An in vitro method to collect and quantify volumes of gaseous microemboli generated by a bubble oxygenator has been developed. Gaseous microemboli generated by a bubble oxygenator are captured and collected in a vortex separation test cell. The cells are pressurized and the resultant pressure changes are converted to volume gas readings using a standard calibration curve.

A doppler type ultrasonic detector and this new technique were compared in order to determine correlation between the two techniques. Results of this study indicate that the ultrasonic detector “counts” do not quantitatively relate to volume of air captured in the test cells. The placement of the ultrasonic detector within the circuit can alter its readings, e.g., proximity to turbulent areas caused by connectors or positive/negative pressure excursions due to the blood pump. Significant differences were noted when fresh, bovine blood with physiologically balanced gases were substituted for lactated Ringer's solution and 100% oxygen due to differences in bubble stability and saturation levels.

Based on these findings, the use of vortex collection cells can provide a more accurate profile of gaseous microemboli production by various cardiopulmonary devices. A circuit and procedure are described for this purpose.
Evaluation des Charlson Komorbiditätsindex als prognostisches
Hilfsmittel zur Einschätzung des Verlaufes von
Handinfektionen
Authors: Sorowka Anne , Grünewald Thomas , Kremer Thomas , Rein Susanne
Published: September 2023

Hintergrund Zur prognostischen Analyse von Komorbiditäten wird der
Charlson Komorbiditätsindex (CCI) genutzt. Komorbiditäten,
insbesondere der Diabetes mellitus, sind ein entscheidender Einflussfaktor
für das Entstehen und den Verlauf von Infektionen der Hand. Ziel der
vorliegenden Studie war es, den CCI bei Patienten mit Handinfektionen zu
ermitteln, um zu prüfen, wie Komorbiditäten den Verlauf und die
Schwere von Handinfektionen beeinflussen.

Material und Methoden Neunzig Patienten mit operationsbedürftigen
Handinfektionen, jedoch ohne antibiotische Vorbehandlung, wurden prospektiv
untersucht. Der jeweilige CCI wurde bei stationärer Aufnahme bestimmt.
Eine Gesamtpunktzahl von null Punkten wurde als „niedriger“, ein
bis drei als „mittlerer“ und vier bis neun Punkte als
„hoher“ Index definiert. Das Alter, der CRP-Wert, sowie die
Dauer des stationären Aufenthaltes und die Anzahl der
durchgeführten Operationen wurden dokumentiert und statistisch
ausgewertet.

Ergebnisse Der Median des CCI lag bei 0,5 Punkten bei einer Spannweite von
0–9 Punkten. Die häufigste Komorbidität war ein Diabetes
mellitus ohne Endorganschäden, gefolgt von der Herzinsuffizienz und
chronischen Lungenerkrankungen. Patienten mit einem niedrigen Gesamtpunktwert
(Median 51 Jahre) waren signifikant jünger als die mit einem mittleren
(Median 60 Jahre; p=0,018) oder hohem Wert (Median 66,5 Jahre;
p=0,018). Außerdem hatten die Probanden mit einem niedrigen oder
mittleren Score einen kürzeren stationären Aufenthalt (Median 6
vs. 11,5 Tage; pniedrig=0,003; pmittel=0,005),
benötigten weniger Operationen (Median 1 vs. 3 Operationen;
pniedrig=0,002; pmittel=0,003) und hatten einen niedrigeren
CRP-Wert (Median 8,3 mg/l vs. 7,1 mg/l vs.
86,25 mg/l; pniedrig=pmittel=0,001) als die mit
einem hohen Index. Der CCI korrelierte signifikant positiv mit dem Alter der
Probanden (Spearmans ρ=0,367; p<0,001), sowie der Dauer
des stationären Aufenthaltes (Spearmans ρ=0,261;
p=0,013), der Anzahl der Operationen (Spearmans ρ=0,219;
p=0,038) und dem CRP-Wert (Spearmans ρ=0,212;
p=0,045).

Schlussfolgerungen Der CCI ist ein geeignetes Hilfsmittel zur
prognostischen Einschätzung des Verlaufes und der Schwere von
Handinfektionen, insbesondere in Hinblick auf die Dauer des stationären
Aufenthaltes, der Anzahl der Operationen und die Höhe des
CRP-Wertes.
No Benefit of Robotic-Assisted over Computer-Assisted Surgery for Achieving Neutral Coronal Alignment in Total Knee Arthroplasty
Authors: Klasan Antonio , Anelli-Monti Victoria , Huber Stephanie , Zacherl Maximillian , Hofstaetter Jochen , Kammerlander Christian , Sadoghi Patrick
Published: September 2023

The use of robotic-assisted surgery (RAS) in total knee arthroplasty (TKA) is becoming increasingly popular due to better precision, potentially superior outcomes and the ability to achieve alternative alignment strategies. The most commonly used alignment strategy with RAS is a modification of mechanical alignment (MA), labeled adjusted MA (aMA). This strategy allows slight joint line obliquity of the tibial component to achieve superior balancing. In the present study, we compared coronal alignment after TKA using RAS with aMA and computer-assisted surgery (CAS) with MA that has been the standard in the center for more than 10 years. We analyzed a prospectively collected database of patients undergoing TKA in a single center. Lateral distal femoral angle (LDFA) and medial proximal tibial angle (MPTA) were compared for both techniques. In 140 patients, 68 CASs and 72 RASs, we observed no difference in postoperative measurements (median 90 degrees for all, LDFA p = 0.676, MPTA p = 0.947) and no difference in outliers <2 degrees (LDFA p = 0.540, MPTA p = 0.250). The present study demonstrates no benefit in eliminating outliers or achieving neutral alignment of both the femoral and the tibial components in robotic-assisted versus computer-assisted TKA if MA is the target. To utilize the precision of RAS, it is recommended to aim for more personalized alignment strategies. The level of evidence is level III retrospective study.
The Impact of Smoking on the Complications of Acute Appendicitis
Authors: Rezqallah Raed Esttaifan , Alrubaie Abdulhadi L.
Published: September 2023

Introduction The pathophysiology of appendicitis likely stems from obstruction of the appendiceal orifice leading to an increase in intraluminal and intramural pressure, resulting in small vessel occlusion and lymphatic stasis. Organ supplied by an end artery, such as the appendix, are more prone to the deleterious effects of arterial occlusion. The continuous cigarette smoking might be associated with a greater risk for developing atherosclerosis.

Objectives The aim is to evaluate the effect of cigarette smoking on the incidence of complications of acute appendicitis.

Methods Patients suffered from symptoms and signs suggesting acute appendicitis were examined and investigated. a multiple items collecting data questionnaire including smoking status and exclusion of confounders were constructed. The complicated and non-complicated appendicitis were compared concerning their smoking status.

Results Seventy-two Patients were included in this study; the mean age of studied patients was 24.13 ± 9.1 years. The age of 57% of patients were below the mean age and considered as younger age group, while the remaining 43% of patients were equal or above the mean age which considered as older age group. Thirty-three percentage of patients had ≥ 36 hours prehospital delay and considered as delay group, while the remaining 67% of patients had < 36 hours prehospital delay which considered no delay group, males constitute 54% of studied patients. smokers constitute 29% while the remaining 71% of studied patients were nonsmokers, 61.9% of the smokers developed complications of appendicitis.

Conclusion Perforated acute appendicitis is higher among current tobacco smokers.
Temporary Stomas after Rectal Cancer Resection; Predilection of Being Permanent and Predictors of Complications?
Authors: Metwally Islam H. , Abdelkhalek Mohamed , Zuhdy Mohammad , Elbalka Saleh S.
Published: September 2023

Stomas are essential for colorectal surgery and are widely used not only for selected cases for bowel obstructions but also in rectal cancer operations to divert stool away from low rectal anastomosis. On the other hand, complications with stomas/ stomas reversal are not uncommon. In this study, we aimed at studying the frequency and the predictors of temporary stomas being permanent, and the contributing factors of surgical stoma/stoma closure related complications. In our cohort, only about 40% of the patient closed their initially planned temporary stomas. The occurrence of intestinal leak, wound sepsis, or any type of morbidity with 30 days of operation were significant predictors of permanent stomas. In addition, alarmingly although Hartmann's procedure was uncommon in our practice, only 9% of those who underwent Hartmann's have had it reversed. Moreover, the only factor that significantly increased stoma related complications was having an end colostomy. There was a tendency toward late closure of stomas with median 8.2 months, however early closure did not correlate to complications. In conclusion, further studies are needed to delineate the low rate of stoma closure. Patients who develop postoperative complications, even wound sepsis, would be at a higher risk of living with permanent stomas. Hartmann's procedures are commonly associated with stoma problems, and reluctance to reverse the stomas.
Twenty-four Hours Stay After Colorectal Surgery; A Systematic Review
Authors: Smalbroek Bo P. , Schuffel Inger-Lise , Weijs Teus J. , Dijksman Lea M. , Poelmann Floris B. , Wijffels Niels A.T. , Boerma Djamila , Smits Anke B.
Published: September 2023

Introduction The introduction of Enhanced Recovery After Surgery led to increasing twenty-four hours discharge pathways, for example in laparoscopic cholecystectomy and bariatric surgery. However, implementation in colorectal surgery still must set off. This systematic review assesses safety and feasibility of twenty-four hours discharge in colorectal surgery in terms of readmission and complications in current literature. Secondary outcome was identification of factors associated with success of twenty-four hours discharge.

Methods Pubmed and EMBASE databases were searched to identify studies investigating twenty-four hours discharge in colorectal surgery, without restriction of study type. Search strategy included keywords relating to ambulatory management and colorectal surgery. Studies were scored according to MINORS score.

Results Thirteen studies were included in this systematic review, consisting of six prospective and seven retrospective studies. Number of participants of the included prospective studies ranged from 5 to 157. Median success of discharge was 96% in the twenty-four hours discharge group. All prospective studies showed similar readmission and complication rates between twenty-four hours discharge and conventional postoperative management. Factors associated with success of twenty-four hours discharge were low ASA classification, younger age, minimally invasive approach, and relatively shorter operation time.

Conclusions Twenty-four hours discharge in colorectal surgery seems feasible and safe, based on retro- and prospective studies. Careful selection of patients and establishment of a clear and adequate protocol are key items to assure safety and feasibility. Results should be interpreted with caution, due to heterogeneity. To confirm results, an adequately powered prospective randomized study is needed.
Sampling Reflex as a New Manometric Marker in the Diagnosis of Defecation Disorders - Systematic Review
Authors: Schlenstein Henrique Perobelli , Silva Gabriel Thiago da , Caliman Gabriella Catharino , Andrade Izabella Dias Muniz de , Rodrigues Marina Silva , Vitoretti Matheus , Migliore Renato , Gentile João Kleber de Almeida
Published: September 2023

Introduction Distension of the rectum wall and subsequent momentary relaxation of the internal anal sphincter (IAS) trigger a reflex called the rectoanal inhibitory reflex (RAIR). This same rectal distension causes a reflex contraction of the external anal sphincter (EAS), responsible for conscious continence called rectoanal excitatory reflex (RAER). This set of reflexes are named sampling reflex.

Objectives The sampling reflex is necessary to initiate defecation or flatulence. The objective of this study is to evaluate the sampling reflex and its practical applicability as a manometric marker of the main defecation disorders.

Methodology This review followed the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) items. The development method consisted of searching for articles in the research platforms BVS, PubMed, Cochrane Library, SciELO and ScienceDirect and for the selection of articles the Rayyan Platform was used. The articles resulting from the search strategies were added to the platform and five collaborators were invited for the blind selection. Finally, 6 articles were included in the final review.

Results An intact sampling reflex allows the individual to facilitate discrimination between flatus and stool and to choose whether to discharge or retain rectal contents. On the other hand, an impaired sampling reflex can predispose an individual to incontinence.

Therefore, it was observed that patients with defecation disorders had an impaired sampling reflex, since it was found that constipated patients have incomplete opening of the IAS, lower amplitude of RAIR and increase of RAER. Most incontinent patients present a failure in the recruitment of the EAS, a decrease in the RAER and an increase in the RAIR, in duration and amplitude.

Conclusion The improvement of high-resolution anorectal manometric techniques was essential for understanding the pathophysiology of defecation disorders, as well as the physiological understanding and importance of RAIR and RAER.
Clinical-Epidemiological Characterization of Human anal Papilloma Virus Infection Coloproctology Unit. Central University Hospital Dr. “Antonio Maria Pineda”
Authors: Mendoza Maria Antonieta , Dowling Enez Victoria , Izarra Henriquez Carla
Published: September 2023

Human papillomavirus (HPV) infection is one of the most common sexually transmitted viral diseases. A descriptive cross-sectional study was conducted with the purpose of clinically and epidemiologically characterizing anal HPV infection in patients who attended the Benign Orificial Pathology Consultation of the Coloproctological Unit at the Dr. “Antonio María Pineda” Central University Hospital, during the period March 2022 - February 2023, by selecting 288 patients whose average age was 47.09 ± 14.61 years, being the 41-50 years old group (29.17%) and the 51-60 years old group (19.44%) the most affected groups by pathologies of the anal region, with a predominance of male (54.17%). The sociodemographic characteristics with the highest frequency included married (48.61%) and single (47.22%); secondary level of education (44.44%) and traders (18.05%) and housewives (15, 28%) as predominant occupations. The risk factors were represented by onset of sexual intercourse between 16-20 years of age (65.28%), heterosexuality (91.67%), 22.22% reported having anal sex and 5.56% oral sex. Likewise, 5.56% were reported with a history of genital HPV and 4.17% were HIV positive. In addition, 48.61% stated not to use condoms. The initial clinical diagnosis included hemorrhoidal disease (30.55%), anal fistula (25%) and anal fissure (18.05%), and one patient (1.39%) with anal HPV infection. Anal cytology results showed 8.33% flat epithelial cells with cytopathic changes suggestive of HPV infection and 1.39% squamous cells with cytopathic changes suggestive of HPV infection: 50% mild inflammatory negative for malignancy and 33.33% flat epithelial cells without atypia. In conclusion, the anal cytology investigation should continue to determine the actual frequency of anal HPV infection.
Effect of magnetic field assisted thermal diffusion on microstructure and properties of titanium alloy laser cladding coating
Authors: Wei Xu , Fei Bai Jing , Yong Li
Published: September 2023

Ti–Al composite coating was prepared on the surface of a titanium alloy by the laser cladding technology and coaxial powder feeding under argon protection. The cladding material was AlSi10Mg aluminum alloy powder. The intermediate sample was thermally diffused at high temperature for 6 h and then placed in a certain intensity of the alternating electromagnetic field until completely cooled. The alloy substrate and coating solidified under the action of the alternating electromagnetic field, and the surface coating of a high strength titanium alloy was obtained. The morphology and microstructure of the composite coating were analyzed by SEM, XRD, and energy dispersive spectroscopy (EDS), and the hardness of the coating was measured. The results showed that the high temperature thermal diffusion promoted the interatomic diffusion; repaired some defects, such as cracks and pores; and eliminated the elemental metals that did not participate in the reaction, and the surface hardness of the coating joint reached the maximum. The electromagnetic stirring makes the titanium alloy coating and substrate bond well, the joint is relatively straight, the number of cracks and pores is obviously reduced, and the comprehensive performance of the coating is improved.
Wollemi
Authors: Tidy Samantha , Gyan Rachel
Published: September 2023

Deep in the forest, an ancient wonder is about to be found. Descended from a family of trees going back 200 million years, the Wollemi pine has survived ice, fire and the passing of many generations.

Will a bushfire be the final threat to this living fossil? And how will we protect it, now that everyone wants a dinosaur tree? How can we make sure the Wollemi’s secret location is not discovered and damaged?

Wollemi: Saving a Dinosaur Tree explains the unique and critically endangered status of the Wollemi pine and explores what actions can be taken today to contribute to the conservation of this rare and beautiful tree.

Reading level varies from child to child, but we recommend this book for ages 6 to 9.
A new longevity record for a wild European rabbit (Oryctolagus cuniculus) from South Australia
Authors: Peacock David E. , Sinclair Ron G.
Published: September 2023

A population of wild European rabbits (Oryctolagus cuniculus) was regularly monitored from November 1996 to April 2022, using mark–recapture as part of a longitudinal epidemiological study into two Australian rabbit biocontrol agents, rabbit haemorrhagic disease (RHD) and myxomatosis. A female rabbit, first captured as a subadult on 26 October 2009, was recaptured 16 times before its final capture on 19 February 2019. The longevity of this rabbit, from its calculated birth date to the date of its last capture, was 9.5 years. This is a record lifespan for a wild European rabbit – acknowledging that such longevity might be specific to our site in temperate South Australia. It exceeds our previous reported record from the same site by 2 years.
IETS management of the challenges associated with embryo pathogen interaction
Authors: Thibier Michel , Perry George
Published: September 2023

One of the very first challenges the International Embryo Transfer Society (IETS) addressed was concern about disease transmission via the transfer of in vivo–derived (IVD) bovine embryos. IETS commissioned its Import/Export Committee, later named Health and Safety Advisory Committee (HASAC), to resolve this matter, with the assistance of the Data Retrieval Committee following its formation in 1991. Since its first meeting in 1984, considerable achievements have been made, including meeting the numerous challenges created by the many innovations in this industry. Based on research studies and their designs, the IETS HASAC developed a system for categorising pathogens and diseases potentially susceptible to interaction with IVD embryos. This has been instrumental in defining safe operating protocols and ultimately leading to the development of the now universally accepted techniques for certification of embryo health. The close cooperation of IETS/HASAC with the World Organization of Animal Health (WOAH, formerly OIE) has facilitated the establishment of guidelines for regulators worldwide, thus ensuring the safety of international trade with embryos, while avoiding unjustified regulatory measures. In addition, IETS/HASAC produced and published the IETS Manual: A Procedural Guide and General Information for the Use of Embryo Transfer Technology Emphasising Sanitary Procedures for the embryo transfer industry (1st edition, 1987; 5th edition, 2023). This manual and its updates were designed to provide the industry world-wide with a source of information on safe and sanitary handling procedures for embryos, to describe the procedures necessary to ensure that the transfer of embryos does not result in transmission of pathogenic agents or disease, and to ensure consistent and accurate identification of embryos. The result of these 40 years of IETS/HASAC involvement is that embryo transfer technology is recognised as having a comparative advantage in international movement of germplasm.
Extending methods for assessing fuel hazard in temperate Australia to enhance data quality and consistency
Authors: Pickering Bianca J. , Bennett Lauren T. , Cawson Jane G.
Published: September 2023

Background Assessments of fuel (vegetation) are needed to predict fire behaviour. Broad visual methods support quick in-field management decisions but can be too imprecise to detect variations in fuel for other purposes. Aims We evaluated the utility of integrating more comprehensive fuel measurement techniques into an existing visual fuel hazard assessment method. Methods We developed an extended method for measuring fuel hazard, including line-intercept measurements and clearer tables for assigning fuel hazard scores, and compared it with the existing Overall Fuel Hazard Assessment Guide fourth edition, which is often used in temperate Australia. Methods were tested across 69 eucalypt woodland plots of the same broad fuel type. Key results The existing method estimated higher near-surface and elevated cover compared with the extended method, but less surface cover. Assigned hazard scores changed markedly when using the clearer hazard tables. Over half the plots had differences of one or more in hazard score for surface, near-surface and elevated fuel between the existing and extended methods. Conclusions The extended method provided a more methodical and consistent approach for assessing fuel hazard, but was more time-consuming than the existing method. Implications The extended method provides an alternative method for monitoring and research purposes when data quality is important.
Reward expectations direct learning and drive operant matching in
Drosophila
Authors: Rajagopalan Adithya E. , Darshan Ran , Hibbard Karen L. , Fitzgerald James E. , Turner Glenn C.
Published: September 2023

Foraging animals must use decision-making strategies that dynamically adapt to the changing availability of rewards in the environment. A wide diversity of animals do this by distributing their choices in proportion to the rewards received from each option, Herrnstein’s operant matching law. Theoretical work suggests an elegant mechanistic explanation for this ubiquitous behavior, as operant matching follows automatically from simple synaptic plasticity rules acting within behaviorally relevant neural circuits. However, no past work has mapped operant matching onto plasticity mechanisms in the brain, leaving the biological relevance of the theory unclear. Here, we discovered operant matching in
Drosophila
and showed that it requires synaptic plasticity that acts in the mushroom body and incorporates the expectation of reward. We began by developing a dynamic foraging paradigm to measure choices from individual flies as they learn to associate odor cues with probabilistic rewards. We then built a model of the fly mushroom body to explain each fly’s sequential choice behavior using a family of biologically realistic synaptic plasticity rules. As predicted by past theoretical work, we found that synaptic plasticity rules could explain fly matching behavior by incorporating stimulus expectations, reward expectations, or both. However, by optogenetically bypassing the representation of reward expectation, we abolished matching behavior and showed that the plasticity rule must specifically incorporate reward expectations. Altogether, these results reveal the first synapse-level mechanisms of operant matching and provide compelling evidence for the role of reward expectation signals in the fly brain.
Seeing is believing: The development of optical coherence tomography
Authors: Nathans Jeremy
Published: September 2023

The 2023 Lasker-DeBakey Clinical Medical Research Award is being presented to James Fujimoto, David Huang, and Eric Swanson for their invention and development of optical coherence tomography (OCT), an imaging technology that uses light to visualize microscopic structures within tissues such as the retina. OCT has dramatically changed the practice of ophthalmology and improved the lives of millions of people. It also has great potential in a wide range of other medical fields.
Numerical analysis of ultrasonic spot welding of metal sheets: A review
Authors: Ni Z. L. , Li B. H. , Liu Y. , Huang L. , Nazarov A. , Wang X. X. , Yuan Z. P. , Ye F. X.
Published: September 2023

Ultrasonic spot welding has recently garnered significant attention as a method for joining metal sheets. Numerical simulation plays an important role in understanding the principles of this process and improving the quality of the ultrasonic spot welded joint. This paper aims to summarises the critical parameters in the finite element model of ultrasonic spot welding, including the friction coefficient, thermal field, acoustic and thermal softening, meshing and boundary conditions. Additionally, it provides a detailed review of the research status related to the simulation results, such as welding interface temperature, stress distribution, plastic strain, intermetallic compounds, macrostructure, dynamic recrystallisation and interfacial diffusion. Furthermore, this paper discusses the remaining challenges and the development trend of the numerical simulation.
Ab initio investigation of structural, elastic, and thermodynamic characteristics of tetragonal XAgO compounds (X = Li, Na, K, Rb)
Authors: Allali Djamel , Amari Rabie , Bouhemadou Abdelmadjid , Boukhari Ammar , Deghfel Bahri , Essaoud Saber Saad , Bin-Omran Saad , Radjai Missoum , Khenata Rabah , Al-Douri Yarub
Published: September 2023

The present research utilizes ab initio computations to examine the thermodynamic, structural, and elastic characteristics of XAgO ternary oxides, where X signifies Li, Na, K, and Rb.The GGA-PBE and GGA-WC functionals were used to calculate the ground-state lattice parameters and atomic position coordinates of the title materials. The calculated results were in good agreement with both experimental measurements and theoretical predictions. This suggests that the GGA-PBE and GGA-WC functionals are accurate for describing the structural properties of the material under study.This study offers computational predictions for the elastic properties of monocrystalline structures and polycrystalline aggregates of XAgO compounds. These predictions encompass various key parameters, including single-crystal elastic constants, Young’s modulus, bulk modulus, Lame coefficients, Poisson’s ratio, shear modulus, and Debye temperature. Additionally, the quasi-harmonic Debye approximation is utilized to explore the temperature-dependent behavior of bulk modulus, Debye temperature, volume thermal expansion coefficient, and isobaric and isochoric heat capacities over an extensive temperature range, while maintaining constant pressures. The results obtained from this model are found to be highly successful in accurately predicting the behavior of these properties.
Comparison of single event effect on cascoded low noise amplifier performance metrics for two different frequencies
Authors: Rajendiran P
Published: September 2023

This manuscript examines the impact of single event effects (SEEs) on the well-known cascoded low noise amplifier (LNA) topology connected with an inter-stage inductor sandwiched between the common source (CS) and common gate transistors for boosting the LNA parameters (i.e., gain, etc). In this article, we have considered that the LNA operates at two different frequencies, such as 10 and 30 GHz, in a radiation-prone environment. The effect of SEEs is analyzed in two ways: (i) non-applying a RF input with dc voltage only, and (ii) applying a RF input with dc bias voltage. The first analysis uses basic integration to evaluate the collected charge (QCollected) for a drain terminal momentary current spike with a suitable time period, and the second analysis estimates the LNA output discontinuity (distortion) using a spectrogram (short-time FFT) to determine the radiation strikes on the cascoded LNA. The collected charge is calculated in the temporal analysis, and the discontinuity of LNA’s RF output is analysed using the spectrogram in the frequency domain analysis. From the temporal and frequency analysis, the LNA that operates at a lower frequency (10 GHz) provides more discontinuity in LNA output (causing more disturbance) than the LNA that operates at a higher frequency (30 GHz).
Unimodal distribution of terahertz emission from single-color filament plasma
Authors: Rizaev G E , Pushkarev D V , Koribut A V , Levus M V , Grudtsyn Y A V , Mokrousova D V , Seleznev L V
Published: September 2023

We study the angular distributions of various spectral components of terahertz radiation generated in an air plasma of a single-color filament with a laser wavelength of 930 nm. It is experimentally shown that at a 20-fold excess over the critical power for self-focusing the distribution of terahertz radiation at all studied frequencies is unimodal. The obtained pattern differs significantly from the angular distribution of terahertz radiation observed in the case of filamentation of pulses with a shorter wavelength.
Two-dimensional MXene Ti3C2 for Efficient Photoacoustic Conversion
Authors: Zhou Kuangyu , Shao Zhihua , Qiao Xueguang
Published: September 2023

Two-dimensional MXene are potential photoacoustic conversion materials due to the excellent light absorption and photothermal conversion efficiencies. In this study, we theoretically analyze and experimentally demonstrate the photoacoustic properties of Ti3C2. High-intensity ultrasonic waves are generated by irradiating Ti3C2 films with 532 nm pulsed laser. By comparison, the signal amplitude of Ti3C2 is about twice as much as that of graphene. We validate the potential of Ti3C2 as an efficient functional material for photoacoustic or laser ultrasonic applications.
Sensing Characteristics of a Three-Ring Grating Slit Micro Ring Resonator
Authors: Zhu Yanjie , Liang Longxue
Published: September 2023

In this paper, a micro ring resonator with slit structure of three-ring grating is proposed to make the refractive index micro ring sensor have higher quality factor and sensitivity. Based on the traditional micro ring resonator, the structure adopts three micro rings and adds grating structure to the rings, which can realize the EIT-Like effect at different wavelengths. Furthermore, the quality factor and sensitivity of the micro ring resonator are improved. The structure is simulated using the finite difference time-domain (FDTD) technique and the influence of device parameters on the structure is investigated. Quality factor was found to be up to 24845, over threefold higher than conventional microring sensors. The sensitivity is 224.2nm/RIU, more than two times higher than the conventional micro ring refractive index.
Research on the Development of Chromatic Aberration Selection Model for Optical Bifocal Glass Lens
Authors: Wu Bowen , Hsueh Boren , Lin Wenchieh , Huang Chouchun , Kao Chihchen
Published: September 2023

This research aims to develop a model for selecting bifocal glass lens based on their formal design, configuration, and optical properties, particularly chromatic aberration. The model optimization integrates Taguchi-Fuzzy theoretical analysis. By utilizing the Fuzzy theory system along with Taguchi L9 orthogonal table, the model achieves high-precision experimental results with a minimal number of designs, leading to the identification of the optimal design combination. The first section of the study explains the motivation behind the research and conducts a literature review to analyze the optical quality parameters of bifocal glass lens. The second section focuses on the analysis of lens optical lateral and longitudinal chromatic aberrations, optimizing the chromatic aberration model through the application of the Taguchi-Fuzzy experimental method. The feasibility of the model is then validated through variance analysis. Finally, the third section provides a summary of the bifocal glass lens selection model, highlighting its contributions to design, practicality, analysis, innovation, and overall advancements in the field.
Design and Experimental Analysis of an Optical Fiber Coupling System for a Ground-based Telescope with Adaptive Optics
Authors: Wang Chaoyan , Ge Jian , Cai Jianqing , Li Lingxiao
Published: September 2023

Astronomy photonics has opened up a new era for the application of astronomical optical instruments. The fiber coupling system serves as the crucial link between the telescope and photonic devices. This paper explores a beam shaping method that utilizes a coupled lens to enhance the efficiency of coupling light into an optical single mode fiber. Compared to directly coupling the telescope beam into the fiber, this approach offers improved coupling efficiency and greater adjustment tolerance. The laboratory-based optical fiber coupling system described in this study comprises an imaging component with an F/50 ratio and a fiber coupling component. Theoretical analysis indicates that optimal coupling efficiency is achieved when the diameter of the focusing spot, limited by diffraction, matches the fiber core size. Any axial error, position error, or tip-tilt error between the lens and the fiber will reduce the coupling efficiency. Experimental results confirm that the coupling system achieves an efficiency of approximately 70%, which is close to the theoretical limit of 78%. These findings underscore the effectiveness of the fiber coupling method.
Analysis of Imaging Characteristics of Wide-field Lobster Eye Lens
Authors: Ma Shizhang , Ouyang Mingzhao , Fu Yuegang , Hu Yuan , Zhang Yuhui , Yang Yuxiang , Wang Shengyu
Published: September 2023

The lobster-eye lens is a reflected type focusing optics. It can be used for backscattering imaging that is a single-sided access technology for homeland security, detection of improvised explosive devices, non-destructive testing, and medical imaging. The aim of this study was to investigate the imaging characteristic of meridional lobster-eye lens with a planar imaging surface. The larger the field of view, the greater the spherical aberration, and the larger the field curvature of the edge field of view. Both spherical aberration and field curvature increase the size of the focal spot, and the images become blurry. Rays with a large angle of grazing incidence have large spherical aberration and curvature. The reflectivity of these rays drops sharply as the energy of photons increases. Therefore, spherical aberration and field curvature have a greater effect on photons with low energy. These conclusions can help improve the design of a lobster-eye lens for wide-field imaging applications.
Numerical Solution for a Fractional Differential Equation Arising In Optics
Authors: Feng Yu , Ma Dexiang
Published: September 2023

A new recursive algorithm (named as Abel-ADM) is given to obtain approximate solution for a class of nonlinear fractional differential equation arising in optics. Abel-ADM is a method that combines the generalized Abel equation with the Adomian decomposition method (ADM). The effectiveness of the method was verified through numerical examples.
Study on the Technique for Wavelength Modulation Spectroscopy with Narrow Band Interference Filter Based External Cavity Diode Laser
Authors: Xiao Xiao , Zhang Jianquan , Zhou Guopeng , Yu Fengqi , Lawrence George N. , Wang Zhibin
Published: September 2023

In this study, an improved tunable external cavity diode laser (ECDL) is proposed. It is on the basis of narrow band interference filter, and its theoretical research is carried out as the light source of tunable diode laser absorption spectrum-wavelength modulation spectrum (TDLAS-WMS) system. The proposed model can use piezoelectric ceramic actuator to change and modulate its output central wavelength so that the laser central wavelength could periodically scan the absorption spectral band of the desired gas. Compared with the tunable monolithic diode laser, the narrow band interference filter based tunable ECDL might be able to accurately sense the type and concentration of a large variety of gases. Therefore, it can be used in the TDLAS-WMS system for high precision gas sensing and is expected to replace the tunable monolithic diode laser.
Full-Stokes Polarization Raman Microscope
Authors: Chen Zeyu , Zhang Chunmin
Published: September 2023

Polarization Raman spectroscopy (PRS) can provide additional information regarding molecular orientation and symmetry compared to Raman spectroscopy, while traditional PRS only records parallel and perpendicular components of Raman scattered light. Recently, a channelled polarization Raman microscope was developed to acquire the linear-Stokes polarization Raman spectra. Since the circular polarization Raman spectra may contain important information related to molecular structure, a full-Stokes polarization Raman microscope (FPRM) is presented in this paper. A polarization modulator consisting of two high order retarder and a linear polarizer is used to modulate the full-Stokes polarization information into frequency domain, and the polarization demodulation is achieved by the Fourier transformation method. Only one camera shot is needed to acquire all polarization components of the Raman scattered light, and the feasibility of FPRM is verified by simulations.
Design of a Redundant 6-DOF Parallel Platform for Mirror Precision Pose Adjustment
Authors: Liang Fengchao , Tan Shuang , Fan Jiankai , Zhang Ai , Lin Zhe , Shi Zhicheng
Published: September 2023

The pose control of 6-DOF parallel mechanism depends on the measurement accuracy of the position of the active driving strut, which affects the pose control accuracy of 6-DOF parallel mechanism. In order to overcome the influence of heavy load large impact force on the measurement accuracy of the active drive strut, a redundant 6-DOF parallel mechanism that separates the measurement struts from the active drive struts was proposed. The fixed platform and the moving platform are connected by six identical active drive struts and six redundant measurement struts. The active driving strut is an active motion unit used to achieve various pose movements of the parallel mechanism, and the follower redundant measurement strut is a precision measurement unit, and does not constrain any DOF of the platform. Only the follower accurately measures the distance between the upper and lower hinge points of the redundant hinges. The accurate position and pose of the 6-DOF parallel mechanism are obtained by using the forward kinematics solution. The controller is used to implement the pose closed-loop control algorithm to achieve precise pose control. The design of this redundant 6-DOF parallel mechanism improves the movement accuracy of the parallel mechanism under heavy load. It can be applied to the precision adjustment of the primary mirror or secondary mirror under heavy load in large aperture optics, and has strong engineering application value.
Field Extended Birefringent Static Doppler Wind Imaging Interferometer
Authors: Yan Tingyu , Shu Lingfeng , Luo Wenyi , Han Chao , Zhang Chunmin
Published: September 2023

According to the requirements for wide field of view and high resolution in wind imaging detection, the principle of a novel field extended birefringent wind imaging interferometer is proposed. Based on the principle of birefringent polarization wind imaging interferometer, the new optical system scheme of the field extended birefringent static Doppler wind imaging interferometer is designed, which overcomes the limitation of the field of view in the original birefringent polarization wind imaging interferometer. Compared with the original scheme, the new scheme eliminates the cross-field phase change between the top and bottom fields, and the available field of view of the instrument is no longer limited. The Jones matrix model are used to simulate to prove the correctness of the principal scheme of the field extended birefringent wind imaging interferometer.
Path optimizing of UAV inspection for 500kV AC transmission line cup-tower based on ant colony algorithm
Authors: Guo Hao , Liu Shushan , Xu Li , Wang Zhigang , Li Hui , Chen Bin
Published: September 2023

To ensure unmanned aerial vehicles (UAVs) complete the inspection task of a high-voltage transmission line safely and effectively, it is necessary to consider the interference of a complicated electromagnetic field near a high-voltage transmission line and determine a reasonable inspection distance and path of the UAV. Taking the 500kV EHV AC power line as an instance, firstly, the three-dimensional model of the 500kV ZV1 cup-tower is built, and the finite element method (FEM) is used for computing the electric field and magnetic field of the UAV exterior. According to inspection specifications, the electromagnetic field protection threshold of the UAV is determined, and then the safety area between UAV and the split conductor is determined to be equal to 1.5 m. Combined with the UAV shooting field of view and safety distance, the spatial positions of UAV hovering shooting points are selected to ensure that UAV flies in a safe area. Finally, the path of UAV traversing hovering shooting points is optimized by the ant colony algorithm (ACO), and the optimal path distance is 109.4 m.
Safety Simulation Analysis of Supporting Structure for Live Working Used Insulation Platform on 10KV Lines
Authors: Feng Yu , Wu Shaolei , Wu Kai , Wang Zhijian , Wang Wei
Published: September 2023

The insulation platform mainly comprises insulation tubes, carrying personnel for live working at high altitudes. The structure is prone to deformation, fracture, and vibration under stress. The model of supporting structure is established by Solidworks software. Ansys Workbench is used for static and modal analysis of supporting structures. The results show that the connection between the supporting and front insulation tubes is weak with the maximum stress, and the maximum deformation and vibration occur at the supporting and main platforms. The change of the angle between the supporting insulation tube and the front insulation tube and the angle between the two supporting insulation tubes will cause the maximum stress of the structure to change. The optimal range of the angle is determined finally. The results can be used for the structural optimization of the insulation platform, which is significant for improving its safety performance.
MPC-based energy management strategy for a substation PEDF System
Authors: Zhao Chongjuan , Wang Chang , Jiang Jianjie , Lei Yusong , Zhu Sicheng , Wei Shutian , Zhan Ruifeng , Hu Yuying , Ke Ji
Published: September 2023

According to the optimal scheduling and balanced utilization of power generation units, energy storage, and flexible loads in the PEDF(photovoltaic, energy storage, direct current and flexibility) system of a substation, and realizing stable operation with different time scales and operation modes, this paper proposes a hierarchical control framework, which includes energy management layer, power conversion layer, stability control layer, and an MPC-based energy management strategy based control. Among them, the energy management system uses the prediction of the absorbed power and current of the distributed generation units and loads, and based on the technology of model predictive control to generate the optimal reference power and decision variables for the system to decide the on/off of the system’s dispatchable generation unit and the operation mode of photovoltaic and battery. Finally, the proposed control architecture and strategy are validated by a substation PEDF system.