bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of co-production in a conflictual planning process: the case of Haga station in Gothenburg, Sweden
Authors: Stepanova Olga , Polk Merritt
Published: March 2023

This paper draws on the intersection of the themes of co-production, knowledge use, and planning that are relevant for urban transformation debate. In theory, co-production is seen to have the potential to facilitate conflict resolution, and thereby contribute to inclusive governance and transformative change. However, critical voices argue that these theoretical aspirations have limited effects in practice. Here we analyze the role of co-production in urban planning to better understand its role in conflict resolution and its potential to contribute to urban transformation. We provide a knowledge-based analysis of the possibilities and limitations of institutional and participatory co-production as it is conceived, designed, and applied in a specific conflictual strategic planning process in a case of Haga station which is a part of complex infrastructure development project, the West Link, in Gothenburg, Sweden. Through conducting an in-depth qualitative empirical analysis of the knowledge use practices in the planning of Haga station, we bring the discussion of co-production from theory to practice and take a critical look at its limitations. The results show that co-production worked well within and among the participating governmental organizations, even across distinct organizational boundaries. However, it was more limited between the public organizations and informal opposition actors, despite formal structures and processes aimed specifically at these types of participation. The analysis of knowledge use practices shows how the conflict was exacerbated due to the conflation of incommensurable knowledge claims by the institutional and oppositional actors, leading to a crisis of legitimacy for the involved public agencies.
Pharmacognostic standardisation of the leaves of Costus afer Ker Gawl. (Zingiberaceae) and Palisota hirsuta (Thunb.) K. Schum. (Commelinaceae)
Authors: Sonibare Mubo A. , Isola Aanuoluapo O. , Akinmurele Opeyemi J.
Published: March 2023

Background

Microbes’ resistance to orthodox drugs and continued emergence of new infections call for search of new drugs that can mitigate such resistance and cure newly emerging infections. Despite the therapeutic importance of Costus afer and Palisota hirsuta, the detailed pharmacognostic characters of the two plants are still missing in the literature. Thus, this study evaluated the pharmacognostic characters of these plants and the antimicrobial activity of the plants’ methanol extract. Macroscopic, microscopic, fluorescence analysis, phytochemical screening, heavy metal analysis, proximate, antimicrobial assay and Gas Chromatography–Mass Spectrometry analyses were carried out on both plants.

Results

The microscopic evaluation showed that the epidermal layer of Costus afer is hypostomatic with polygonal shaped epidermal cells and cyclotic stomata on abaxial layer while the epidermal layer of Palisota hirsuta leaf is amphistomatic, having polygonal shape epidermal cell, trichomes and paracytic stomata. The proximate analysis showed that both plants have a high carbohydrate content (C. afer: 59.13% and P. hirsuta: 68.28%) but a low crude fat content (C. afer: 1.867% and P. hirsuta: 0.233%). The heavy metal analysis revealed a high content of Manganese (266.80 mg/100 g) in Palisota hirsua, and a high content of iron (43.94 mg/100 g) in Costus afer. Both plants are free of lead. The phytochemical screening showed that both plants have saponins, tannins, flavonoids, alkaloids and cardiac glycosides. Alkaloids are the highest constituents in Costus afer (9.1%) and Palisota hirsuta (7.1%). The antimicrobial assay showed both plant extracts had the highest inhibitory effect on both bacteria and fungi at 100 mg/kg. Six compounds and 23 compounds were identified by GC–MS in C. afer and P. hirsuta, respectively. Methyl stearate (40.43%) and hexadecanoic acid, methyl ester (25.62%) were the prevailing constituents identified in C. afer and P. hirsuta, respectively.

Conclusion

The pharmacognostic features of Costus afer and Palisota hirsuta shown in this study can be used to design a suitable monograph which would be useful in compilation of another edition of Nigeria Herbal Pharmacopoeial. The dominant compounds in both plants can serve as chemotaxonomic markers for correct identification of the two plants.
Since Time Immemorial
Authors: Yannakakis Yanna
Published: March 2023

In Since Time Immemorial Yanna Yannakakis traces the invention of Native custom, a legal category that Indigenous litigants used in disputes over marriage, self-governance, land, and labor in colonial Mexico. She outlines how, in the hands of Native litigants, the European category of custom—social practice that through time takes on the normative power of law—acquired local meaning and changed over time. Yannakakis analyzes sources ranging from missionary and Inquisition records to Native pictorial histories, royal surveys, and Spanish and Native-language court and notarial documents. By encompassing historical actors who have been traditionally marginalized from legal histories and highlighting spaces outside the courts like Native communities, parishes, and missionary schools, she shows how imperial legal orders were not just imposed from above but also built on the ground through translation and implementation of legal concepts and procedures. Yannakakis argues that, ultimately, Indigenous claims to custom, which on the surface aimed to conserve the past, provided a means to contend with historical change and produce new rights for the future.
Evaluation of nitrate concentrations in groundwater of Llío and San Pablo, Guano – EC
Authors: Mendoza Benito , Barrazueta Rojas Sandra Gabriela , Rivera Castillo María Fernanda , Pacheco Cunduri Mayra Alejandra , Brito Daniela
Published: March 2023

This paper analyzes the groundwater of the Chambo aquifer in the Llío and San Pablo sector, with emphasis on the temporary alternation of nitrate concentration, identifying the anthropogenic activities that may influence this area. This from the cartographic definition of the areas of begging influence the crossing of geological, hydraulic and anthropic activities. The temporality of the geochemical data is 5 years (2016-2020), these results show that water quality meets the requirements of the Ecuadorian national standard,  and that the main composition of water is bicarbonated type of calcium-magnesium. Even if the groundwater in this sector meets the standard, variation in nitrate concentration is evident. This type of concentration is presented by the effect of agricultural activities on the surface of the soil, where nitrates occur naturally due to the nitrogen cycle, and that are dragged into the water table by infiltration when the rainy season occurs. In addition, it was found that the type of rock found underground cannot naturally generate nitrates.
Respecting values and perspectives in biobanking and genetic research governance: Outcomes of a qualitative study in Bengaluru, India
Authors: Vaz Manjulika , Warrier Prasanna , Wai-Loon Ho Calvin , Bull Susan
Published: March 2023

Background: The promise of biobanking and genetic research (BGR) in the context of translational research towards improving public health and personalised medicine has been recognised in India. Worldwide experience has shown that incorporating stakeholders’ expectations and values into the governance of BGR is essential to address ethical aspects of BGR.  This paper draws on engagement with various stakeholders in the South Indian city of Bengaluru to understand how incorporating people’s values and beliefs can inform policy making decisions and strengthen BGR governance within India.

Methods: We adopted a qualitative research approach and conducted six focus group discussions with civil society members and seven in-depth interviews with key informants in BGR, identified through a targeted web search and snowballing methods, until data saturation was reached. Data were thematically analysed to identify emergent patterns.

Results: Specific themes relating to the ethics and governance of BGR emerged. Fears and uncertainty about future sample and data use, possibilities of discrimination and exploitation in the use of findings and the lack of comprehensive data protection policies in India along with expectations of enhanced contributor agency, control in future use of samples and data, benefit sharing, enhanced utility of samples, sustained BGR and public good, reflected tensions between different stakeholders’ values and beliefs. Fair governance processes through an independent governance committee for biobanks and a system of ongoing engagement with stakeholders emerged as best practice towards building trust and respecting diversity of views and values.

Conclusions: Ensuring public trust in BGR requires listening to stakeholders’ voices, being open to counter narratives, and a commitment to long term engagement embedded in principles of participatory democracy. This is central to a ‘people-centred governance framework’ involving a negotiated middle ground and an equilibrium of governance which promotes social justice by being inclusive, transparent, equitable, and trustworthy.
Maps of degree one, LS category and higher topological complexities
Authors: Rudyak Yuli B. , Sarkar Soumen
Published: March 2023

In this paper, we study the relation between the Lusternik-Schnirelmann category
and the topological complexity of two closed oriented manifolds connected by a degree one map.
Derecho de las relaciones exteriores, Derecho internacional comparado y el papel de los tribunales nacionales en la justicia transicional: los casos de Argentina y España
Authors: Perotti Pinciroli Ignacio
Published: March 2023

El presente artículo realiza un estudio comparativo de la aplicación del derecho internacional por parte de los tribunales superiores de Argentina y España, en relación con los modelos de justicia transicional adoptados en cada caso. Para ello, el trabajo adopta los enfoques teóricos y metodológicos propuestos por el Derecho de las relaciones exteriores y por el Derecho internacional comparado, explicados de manera general en la primera parte. La investigación sugiere que el grado de aplicación del derecho internacional por los tribunales de Argentina y España, al decidir acerca de la posibilidad de enjuiciar criminalmente los delitos de lesa humanidad, tiene relación directa con diversos aspectos del derecho interno de cada Estado.
Remote or in-person cancer support? Therapist and service user preferences
Authors: Johnson Caroline , Gallagher Ailish , Rhodes Ellen , Smith Sue
Published: March 2023

Background/Aims

Remote service delivery became a key method of providing therapy for psychological oncology services during the COVID-19 pandemic and beyond. This study aimed to understand the experiences and preferences of both patients and therapists who undertook remote psychological therapy in a cancer support service, with a view to informing ongoing service provision.

Methods

A total of 99 out of 152 invited patients completed an online mixed-methods (quantitative and qualitative) audit survey. All patient participants had accessed therapy with the psycho-oncology support team at Guy's Cancer Centre in London. Of the 12 therapists and four trainee therapists working in this service, 11 and two from each group (respectively) completed a corresponding survey about their experiences as therapists. For quantitative data, descriptive statistics were collated.

Results

Patients rated their experience of remote therapy as positive, reporting that they felt respected, understood and confident during therapy, and acknowledged the associated advantages of increased accessibility and infection control. Despite this, 87% of patients and 100% of therapists expressed a preference to access or deliver therapy in person, with patients identifying human connection and relationship building as key reasons for choosing in-person delivery. Therapists valued the relational aspects of in-person psychological support and reported that remote delivery had negatively affected the quality of therapy delivered.

Conclusions

Understanding the needs and preferences of patients and therapists is important in informing ongoing psychological service delivery. The results highlight the importance of retaining provision for in-person service delivery and offering choice to patients in how they access psychological support, in line with personalised care recommendations made by the NHS Long Term Plan.
Transition from child and adolescent to adult mental health services: an evaluation
Authors: Majumder Pallab , Nair Sreekumar , Saha Anumita , Choudhury Cherry
Published: March 2023

Background/Aims

Evidence has highlighted dissatisfaction among patients with the process of transitioning from child and adolescent mental health services (CAMHS) to adult mental health services. This study aimed to evaluate compliance with and the impact of recommendations made at a mental health trust to improve the transition process after an audit carried out in 2015.

Methods

A nine-item audit tool was developed based on National Institute for Health and Care Excellence guidelines for transition from CAMHS to adult mental health services. Patient records were obtained from the trust's health informatics service and analysed for the calendar year of 2015, looking at compliance with the guidance. The results were used to implement recommendations to improve the transition process, then the audit was repeated for the calendar year of 2017. Data were analysed using descriptive statistics to compare the two periods and identify areas of improvement, or lack thereof.

Results

A total of 52 and 75 case records were audited in the 2015 and 2017 evaluations respectively. Some improvements were seen in some areas over the 2-year period, such as the introduction of a named transition worker and more joint working between child and adolescent and adult mental health services. However, several domains of practice still had low levels of compliance with recommendations in the 2017 audit, particularly items relating to information sharing and communication with patients and their caregivers.

Conclusions

Further work is needed to improve compliance with recommendations for transitional care in mental health services, particularly in terms of communication and involvement of the patient during this process. More research is needed into the barriers to effective transition and any strategies implemented to improve this process should be evaluated using robust methods. Successful strategies will likely require investment in staff recruitment and retention.
Neonatal abstinence syndrome: paediatric case report
Authors: Maddocks Neil
Published: March 2023

Neonatal abstinence syndrome (NAS) is a severe life-threatening condition, characterised as a spectrum of clinical manifestations observed in neonates where maternal opioid use, both prescribed and illicit, has taken place during pregnancy. This article was written after experience of the condition identified a learning outcome, a potential change in practice, and the differences between out-of-hospital and in-hospital managements of NAS. In addition, this article will aim to identify the complications of NAS, the severity of the condition, and the varying methods of treatment.
Lifting the rug…
Authors: Zaroof Nagina
Published: March 2023

This month, Nagina Zaroof confronts the uncomfortable truth about racism in our society
The bigger, the better
Authors: Hart Karen
Published: March 2023

What are the developmental benefits of larger outdoors equipment, and how are some settings using it to provide varied play and learning opportunities? By Karen Hart
Predicting Banana Yield at the Field Scale by Combining Sentinel-2 Time Series Data and Regression Models
Authors: Zhang Haiyang , Zhang Yao , Li Xiuhua , Li Minzan , Tian Zezhong
Published: March 2023

Highlights

A dataset expansion method based on random sampling could improve the robustness of yield estimation models.

CIRE was more suitable for banana yield estimation.

XGBoost-based banana yield estimation method showed good prediction ability of banana yield.

Abstract. Banana yield prediction at the field level offers significant benefits to growers, packinghouses, crop insurance companies, and researchers. This study explored a remote sensing-based approach for forecasting banana yield at the field scale by using Sentinel-2 (S2) image time series and regression models. First, S2 images of critical phenological periods for bananas were acquired from the Google Earth Engine platform, and these images were treated with cloud and cloud shadow removal. Second, the dataset was expanded by randomly selecting pixels for each field to improve the accuracy of yield prediction. Third, nine vegetation indices (VIs) with high correlation with crop yield were compared and analyzed. Chlorophyll Index Red Edge was selected with a particularly high predictive ability in banana yield prediction. Finally, six regression models, namely, least absolute shrinkage and selection operator (LASSO), support vector regression (SVR), k-nearest neighbors (k-NN), random forest (RF), gradient boosted regression trees (GBRT), and extreme gradient boost (XGBoost), were employed, and their performances were compared. Results showed that the best prediction of banana yield was when 70 pixels were selected for each banana field. Out of nine VIs, comparing different regression models, the XGBoost model emerged as the best learner (the average of R2 for 100 runs in 2019 and 2020 were 0.84 and 0.79, respectively). It was followed by the GBRT model with almost the same performance, which explained 82% and 79% of the banana yield variability for 2019 and 2020, respectively. The LASSO model exhibited the lowest performance of all, but it performed best in terms of stability. The proposed framework applied to satellite image time series can achieve reliable banana yield prediction across years at the field scale. Keywords: Banana yield prediction, Extreme gradient boost, Sentinel-2, Vegetation index.
Distribution of Brick- Versus Spherical-Shaped Wireless Sensors as a Function of Gravity-Filling a Storage Silo and their Recovery from the Corn Grain Mass during Unloading
Authors: Aby Guy R , Maier Dirk E
Published: March 2023

Highlights

Brick-shaped wireless sensors tended to settle about 1/3 of a silo diameter around the center of the peaked grain mass whereas spherical-shaped wireless sensors tended to settle about 3/4 of a silo diameter from the center of the peaked grain mass (and within ¼ diameter of the silo wall).

A mix of both spherical- and brick-shaped sensors of different sizes and weights can be used to achieve targeted placement of wireless sensors within the stored grain mass as a function of gravity filling silos of different sizes.

Abstract. The most utilized automated stored grain bulk monitoring technology relies on temperature sensors incorporated into steel cables that are suspended from the roof to the floor of silos. However, cable-based sensors are expensive and require reinforcing roofs to account for the frictional forces exerted by the grain mass on the cables during loading, settling and unloading. Two shapes of wireless sensors (brick and spherical) were studied as an alternative. In-silo experiments investigated the distribution of wireless sensors as a function of gravity filling a farm silo and recovering the sensors during unloading. In the first experiment, five of each sensor shape (brick and spherical) were placed one at a time in a grain stream flowing repeatedly at 28.6 and 39.6 metric tons per hour (MT/h). The drop-out height was 5.30 m in the first and 3.94 m in the second trial. The results indicate that the brick-shaped wireless sensors tended to settle about 1/3 of a silo diameter around the center of the peaked grain mass whereas the spherical-shaped wireless sensors tended to settle about 3/4 of a silo diameter from the center of the peaked grain mass (and within ¼ diameter of the silo wall). In the second experiment, 44, 15, 20, and 25 wireless sensors were randomly placed, respectively, in the grain mass to test their recapture rate during four unloading trials. The results indicated that all wireless sensors were recovered resulting in a 100% recapture rate. Key findings of this study point toward the need for a mix of both spherical- and brick-shaped sensors of different sizes and weights to achieve targeted placement and greater distribution of wireless sensors within the stored grain mass as a function of gravity filling silos of different sizes. Keywords: Brick shape sensor, Grain quality, Sensor distribution, Sensor recovery, Spherical shape sensor.
Opportunities to Mitigate Particle Drift from Ground-Based Preemergent Herbicide Applications
Authors: Kannan Narayanan , Huggins Christina
Published: March 2023

Highlights

Drift data collected from herbicide applications for corn, soybean, and cotton, including three commercial producers.

Drift volumes and drift distances were estimated and correlated to wind speed, boom length, spray height, tractor speed, and droplet size (DV50).

Boom length and spray height appear to be the dominant parameters affecting drift volume and drift distance, respectively.

The results show a three- to fourfold reduction in drift using a hooded sprayer or spraying in calm weather.

Abstract. Although several best practices are available, there are still opportunities to mitigate off-target pesticide drift, protect nearby sensitive crops, and address health concerns for humans/animals. The purpose of the study is to identify opportunities to mitigate drift from ground-based preemergent herbicide applications. Seven herbicide applications were tested for corn, soybean and cotton, including three regional commercial producers. Drift data were collected using water sensitive cards. ImageJ was used to analyze the droplet spectrum. Drift volumes and drift distances were estimated for each experiment. Data collected on wind speed, boom length, spray height, tractor speed, droplet size (DV50), and chemical application rate were used as explanatory variables of drift volume and drift distance. Individual and multiple linear regressions (MLRs) were carried out between drift volume, drift distance, and the explanatory variables. Our results show a three- to fourfold reduction in drift using a hooded sprayer or spraying in calm weather. Boom length and spray height appear to be the dominant parameters affecting drift volume and drift distance, respectively. The MLR results suggest that we can estimate drift (a) volume reasonably using a combination of boom length, DV50, and tractor speed and (b) distance reliably using a combination of spray height, boom length, and DV50. Keywords: Drift distance, Droplet spectrum, Fence board, Herbicide drift, Hooded sprayer, Preemergent herbicide, Water sensitive card.
Modular Multilevel Converter Based Advanced Traction Power Transmission Substation for High Speed Railway Network in India
Authors: Vemulapati Venkatasupura , Vijaykumar Y. N. , Visali N. , Kumar K.
Published: March 2023

The current power transmission system for Indian railways facing difficulties with voltage unbalance, harmonics and circulation of negative sequence current throughout the power transmission line. In addition, the existence of neutral sections between two adjacent traction substations will cause the speed reduction and is considered as the main limitation for high speed. Traction load is a single phase in nature and it is very difficult to estimate the power flow from adjacent substations to locomotive as well as the location of the train. In this paper advanced common phase traction power transmission system is designed which is much appropriate for high speed railway (HSR) by eliminating neutral sections (NS) and overcome all the fore mentioned power quality (PQ) issues. A simplex algorithm is proposed to estimate the power flow and location of the train. The simulation results are analysed and low scale prototype model is built to validate the simulation outcomes. The results obtained are satisfactory and indicates the system suitability for high speed railway network.
Design and Analysis of Solid State DC-AC Transformer
Authors: Suresh K. , Kumaraswamy I. , Arulmozhiyal R.
Published: March 2023

Multimodal single/dual stage conversion (BSDC) based on a new solid-state DC-AC transformer (SDAT) is proposed. The suggested conversion can perform variable or constant DC voltage operation. A variable DC voltage is controlled dynamically in response to changes in DC input side voltage, allowing the DC-DC conversion stage to always operate at its best. New DC-AC power conversion of 2 port two-way choppers (TBDC) and two-way rectifier/inverter conversion (BRIC) was planned for the implementation of the proposed SDAT. SDAT, consisting of a bi-directional step-down-step-up converter and a bi-directional step-up-step-down converter, has been used as a prototype model to check the suggestion system. Functional concepts of this BSDC converter with TBDC are designed and simulated on the MATLAB/simulink environment network. PWM and control methods have been applied for SDAT to accomplish a wide variety of voltage and power loss reduction in the proposed device. Test bench model hardware is designed and tested to validate the effectiveness and benefits of the proposed approach.
An LLC Resonant Half-Bridge Converter Optimal Design Using First Harmonic Approximation: A Complete Step-by-Design
Authors: Kumar G. Kiran , Elangovan D.
Published: March 2023

There are several industrial uses for LLC resonant converters. The outcome of the converter is greatly influenced by the design and analysis methodologies used. An LLC resonant converter has been designed based on first harmonic approximation (FHA) modelling, and an optimal design technique has been provided in this work. The goal of this research is to provide a thorough design technique for an LLC resonant converter, based on rigorous quantitative analysis of the circuit’s steady-state performance. This study uses FHA technique, which greatly facilitates the model of the system, resulting in a linear circuit that can be analyzed using a standard complex ac-circuit analysis. The FHA methodology is used to establish circuit characteristics and to estimate the outcomes. Although half-bridge power converters are frequently employed in isolated, converters with high-voltage inputs, and medium-power applications are frequently constructed with resonant switching to increase efficiency, a feature that adds complexity but also provides various performance benefits. Two major benefits of the LLC resonant architecture are the soft-switching capabilities of the Power MOSFETs and secondary rectifiers, as well as the ability to operate at zero load. Additionally, the LLC resonant converter is simulated and the results are confirmed using PSIM.
Sobre el proceso de lexicalización de las fórmulas honoríficas con el sufijo "ís(s)imo" en español
Authors: Zieliński Andrzej
Published: March 2023

El objetivo de este estudio es analizar el proceso de lexicalización de las fórmulas honoríficas con el sufijo superlativo ísimo en español. A través de un corpus relativamente amplio de textos no ficcionales fechados entre el siglo XV y el XIX señalaremos las principales razones morfosintácticas, semánticas y pragmáticas que propiciaron el cambio en esta expresión tan productiva del español áureo.
Introducció
Authors: Gargallo Gil José Enrique
Published: March 2023

Introducció al monogràfic
Europeismes fràsics en el llibre de paraules e dits de savis e filòsofs. Estudi diacrònic i contrastiu
Authors: Conca Martínez Maria , Guia i Marin Josep
Published: March 2023

En aquest treball ens hem proposat analitzar alguns dels europeismes fràsics presents al Llibre de paraules e dits de savis e filòsofs (entre 1291 i 1295) de Jafudà Bonsenyor, metge jueu de Barcelona. Es tracta d’una obra escrita en llengua catalana, a partir de “llibres aràbics”, útil per a l’estudi de la transmissió sapiencial d’Orient a Occident, a través d’Al Àndalus i Catalunya. Per a l’anàlisi, hem aplicat el mètode de concordances fràsiques, a partir del qual hem seleccionat, descrit, documentat, contrastat i validat deu proverbis com a europeismes. Ens ha interessat sobretot la localització i comparació de les codificacions en llatí medieval i llengües europees de l’època estudiada (segles XIII, XIV i XV).
La problemática terminológica en los estudios paremiológicos
Authors: Crida Álvarez Carlos Alberto , Sevilla Muñoz Julia
Published: March 2023

En la actualidad un número cada vez mayor de investigadores se dedica a los estudios paremiológicos. Sin embargo, sigue faltando una base sólida en la que apoyar tales estudios, pues la falta de consenso en el uso de una terminología unificada en el campo de la investigación paremiológica en el idioma español es una realidad que, en muchos casos, dificulta o entorpece la labor y el entendimiento, principalmente de los que se inician en este campo científico, al tiempo que dilata los textos, al tener que explicar cada vez los términos empleados. Por eso, el objetivo del presente trabajo es revisar algunos de los términos más conflictivos para proponer la terminología más adecuada, en particular los relativos a la clasificación de paremias y a la metodología aplicada habitualmente en este campo. Este trabajo toma como punto de partida las teorías terminológicas desarrolladas por pioneros en la materia, cuya validez está suficientemente comprobada.
Compact lensless Fizeau holographic interferometry for imaging domain patterns in ferroelectric single crystals
Authors: Mach Marek , Psota Pavel , Žídek Karel , Mokrý Pavel
Published: March 2023

Domain patterns in ferroelectric single crystals are physical systems that are fascinating from a theoretical point of view and essential for many applications. A compact lensless method for imaging domain patterns in ferroelectric single crystals based on a digital holographic Fizeau interferometer has been developed. This approach provides a large field-of-view image while maintaining a high spatial resolution. Furthermore, the double-pass approach increases the sensitivity of the measurement. The performance of the lensless digital holographic Fizeau interferometer is demonstrated by imaging the domain pattern in periodically poled lithium niobate. To display the domain patterns in the crystal, we have used an electro-optic phenomenon, which, when an external uniform electric field is applied to the sample, produces a difference in refractive index values in domains with different polarization states of the crystal lattice. Finally, the constructed digital holographic Fizeau interferometer is used to measure the difference in the index of refraction in the antiparallel ferroelectric domains in the external electric field. The lateral resolution of the developed method for ferroelectric domain imaging is discussed.
Magnetic flux leakage detection based on a sensitivity-enhanced fiber Bragg grating magnetic field sensor
Authors: Qin Qiyong , Zhu Wenhua , Xi Beihang , Yang Tao , Wang Ruohui , Qiao Xueguang
Published: March 2023

We propose a sensitivity-enhanced fiber Bragg grating (FBG) magnetic
field sensor for magnetic flux leakage (MFL) detection. The testing
system consists of the FBG, suspended strain concentration structure,
and two ceramic tubes bonded on a Terfenol-D base. We show the
relation between the MFL and the width and depth of the crack, the
lift-off of the sensor away from the surface of the workpiece, and the
angle between the orientation of the sensor and the magnetization
direction. The experimental results are very consistent with those
obtained from finite element analysis simulations. The sensitivity of
the sensor is increased to 81.11 pm/mT for increasing magnetic
fields and 91.55 pm/mT for decreasing magnetic fields. The MFL
test demonstrates that the sensor can identify a crack with a width of
0.5 mm and depth of 2 mm in an 8 mm thick
workpiece. To the best of our knowledge, the magnetic field sensor
proposed in this work has the highest sensitivity compared with the
same types of sensors. Moreover, the application of an FBG-Terfenol-D
based magnetic field sensor in the MFL test shows good performance.
Compared with traditional electrical MFL testing technologies, the
sensitivity-enhanced optical fiber magnetic field sensor has a higher
resolution and longer survival time in harsh environments.
Ultra-compact all-optical plasmonic switch for three telecommunication windows using a nonlinear Kerr material and Fano resonance
Authors: Pooretemad Siavash , Pav Mohammadreza , Ghattan Kashani Zahra , Granpayeh Nosrat
Published: March 2023

In this study, an all-optical plasmonic switch based on a metal–insulator–metal (MIM) waveguide coupled to two rectangular cavities that are perpendicularly connected to each other through a vertical stub is proposed and analyzed both theoretically and numerically. Rectangular cavities are filled with a nonlinear Kerr material, and the switching operation is achieved by applying a high-intensity pump input into the MIM waveguide to obtain nonlinear cross-phase modulation (XPM) effect. The proposed structure is designed so that it can realize the switching operation at each of the three telecommunication windows of 850, 1310, and 1550 nm. Realizing the switching operation at these three wavelength bands is accomplished by the Fano resonance. In fact, the Fano resonance is utilized to create a band-stop area that is crucial for building a suitable OFF state for the switching operation at two of the three telecommunication windows of 1310 and 1550 nm. The theoretical and numerical results are obtained using the transmission-line model (TLM) and the finite difference time domain (FDTD) method, respectively, the results of which comply well. The proposed ultra-compact all-optical switch has significant applications in photonic integrated circuits (PICs).
Effect of symmetry breaking on multi-plasmon-induced transparency based on single-layer graphene metamaterials with strips and rings
Authors: Yang Guangxin , Liu Zhimin , Zhou Fengqi , Zhuo Shanshan , Qin Yipeng , Luo Xin , Ji Cheng , Xie Yadong , Yang Ruihan
Published: March 2023

A single-layer graphene metamaterial consisting of a horizontal graphene strip, four vertical graphene strips, and two graphene rings is proposed to realize tunable multi-plasma-induced transparency (MPIT) by the coupled mode theory and the finite-difference time-domain method. A switch with three modulation modes is realized by dynamically adjusting the Fermi level of graphene. Moreover, the effect of symmetry breaking on MPIT is investigated by controlling the geometric parameters of graphene metamaterials. Triple-PIT, dual-PIT, single-PIT can be transformed into each other. The proposed structure and results provide guidance for applications such as designing photoelectric switches and modulators.
Fourier ptychographic topography
Authors: Wang Hao , Zhu Jiabei , Sung Jangwoon , Hu Guorong , Greene Joseph , Li Yunzhe , Park Seungbeom , Kim Wookrae , Lee Myungjun , Yang Yusin , Tian Lei
Published: March 2023

Topography measurement is essential for surface characterization, semiconductor metrology, and inspection applications. To date, performing high-throughput and accurate topography remains challenging due to the trade-off between field-of-view (FOV) and spatial resolution. Here we demonstrate a novel topography technique based on the reflection-mode Fourier ptychographic microscopy, termed Fourier ptychograhpic topography (FPT). We show that FPT provides both a wide FOV and high resolution, and achieves nanoscale height reconstruction accuracy. Our FPT prototype is based on a custom-built computational microscope consisting of programmable brightfield and darkfield LED arrays. The topography reconstruction is performed by a sequential Gauss-Newton-based Fourier ptychographic phase retrieval algorithm augmented with total variation regularization. We achieve a synthetic numerical aperture (NA) of 0.84 and a diffraction-limited resolution of 750 nm, increasing the native objective NA (0.28) by 3×, across a 1.2 × 1.2 mm2 FOV. We experimentally demonstrate the FPT on a variety of reflective samples with different patterned structures. The reconstructed resolution is validated on both amplitude and phase resolution test features. The accuracy of the reconstructed surface profile is benchmarked against high-resolution optical profilometry measurements. In addition, we show that the FPT provides robust surface profile reconstructions even on complex patterns with fine features that cannot be reliably measured by the standard optical profilometer. The spatial and temporal noise of our FPT system is characterized to be 0.529 nm and 0.027 nm, respectively.
Nonparaxial propagation and the radiation forces of the chirped circular Airy derivative beams
Authors: Yu Jian , Wang Yiping , Bai Zhiyong , Wu Luping , Fu Cailing , Liu Shen , Liu Yu
Published: March 2023

In this paper, we investigate the nonparaxial propagation dynamics of the chirped circular Airy derivative beams (CCADBs) based on vector angular spectrum method. In the case of nonparaxial propagation, the CCADBs still maintains excellent autofocusing performances. Derivative order and chirp factor are two important physical quantities of the CCADBs to regulate the nonparaxial propagation characteristics, such as focal length, focal depth and K-value. In the nonparaxial propagation model, the radiation force on a Rayleigh microsphere induced the CCADBs are also analyzed and discussed in detail. The results demonstrate that not all derivative order CCADBs can achieve stable microsphere trapping effect. The derivative order and chirp factor of the beam can be used to coarse and fine tune the capture effect of Rayleigh microsphere, respectively. This work will contribute to the more precise and flexible use of circular Airy derivative beams in optical manipulation, biomedical treatment and so on.
Robust single frequency index-patterned laser design using a Fourier design method
Authors: Boohan Niall D. , Corbett Brian , O’Reilly Eoin P.
Published: March 2023

We use a Fourier-transform based method to investigate the magnitude and robustness of mode selectivity in as-cleaved discrete-mode semiconductor lasers, where a small number of refractive index perturbations are introduced into a Fabry-Pérot laser cavity. Three exemplar index perturbation patterns are considered. Our results demonstrate the capability to significantly improve modal selectivity by choosing a perturbation distribution function that avoids placing perturbations near to the cavity centre. Our analysis also highlights the ability to select functions that can increase the yield despite facet phase errors introduced during device fabrication.
High-fidelity ghost diffraction through complex scattering media using a modified Gerchberg-Saxton algorithm
Authors: Hao YiNing , Xiao Yin , Chen Wen
Published: March 2023

In this paper, we propose a modified Gerchberg-Saxton (GS) algorithm to generate random amplitude-only patterns as information carriers in ghost diffraction. With the generated random patterns, high-fidelity ghost diffraction through complex scattering media can be realized with a single-pixel detector. The modified GS algorithm adopts a support constraint in the image plane, which is divided into a target region and a support region. In the Fourier plane, amplitude of the Fourier spectrum is scaled to regulate the sum of the image function. A random amplitude-only pattern can be generated to encode a pixel of the data to be transmitted using the modified GS algorithm. Optical experiments are conducted to verify the proposed method in complex scattering environments, e.g., dynamic and turbid water with non-line-of-sight (NLOS). Experimental results demonstrate that the proposed ghost diffraction is of high fidelity and high robustness against complex scattering media. It is expected that an avenue could be opened up for ghost diffraction and transmission in complex media.
Microbubble-probe WGM resonators enable displacement measurements with high spatial resolution
Authors: Liu Bonan , Liu Shen , Zhang Qiang , Hong Guiqing , Liao Changrui , Xu Xizhen , Liu Liwei , Qu Junle , Wang Yiping
Published: March 2023

A microbubble-probe whispering gallery mode resonator with high displacement resolution and spatial resolution for displacement sensing is proposed. The resonator consists of an air bubble and a probe. The probe has a diameter of ∼5 µm that grants micron-level spatial resolution. Fabricated by a CO2 laser machining platform, a universal quality factor of over 106 is achieved. In displacement sensing, the sensor exhibits a displacement resolution of 74.83 pm and an estimated measurement span of 29.44 µm. As the first microbubble probe resonator for displacement measurement, the component shows advantages in performance, and exhibits a potential in sensing with high precision.
Dual-shearing interferometer for multi-modal hyperspectral imaging
Authors: Bai Caixun , Li Jianxin , Wang Guomei , Lu Cheng , Zhang Huanian , Zhao Yue , Zhang Wenfei , Fu Shenggui
Published: March 2023

A dual-shearing interferometer (DSI) for multimodal hyperspectral imaging is presented. Two orthogonally stacked pairs of coherent beams are generated by a pair of novel, to the best of our knowledge, birefringent lateral shearing splitters. Consequently, two sets of interferograms with full pixel resolution are captured alternately in a time sequence in the double Nyquist frequency mode. Modals of dual-field-of-view hyperspectral imaging and differential-polarization hyperspectral imaging are introduced, and verification experiments are performed. The feasibility of other modals is discussed. The proposed method can effectively improve the instrument’s performance in terms of the field of view, polarization, spectral resolution, and spectral range.
High-energy femtosecond pulse generation from a hybrid mode-locked large-mode-area Er:ZBLAN fiber laser
Authors: Yu Linpeng , Tang Ziya , Liang Jinhui , Zeng Qinghui , Wang Jiachen , Luo Xing , Wang Jinzhang , Yan Peiguang , Dong Fanlong , Liu Xing , Lue Qitao , Guo Chunyu , Ruan Shuangchen
Published: March 2023

We report a hybrid mode-locked fiber laser at 2.8 µm based on a large-mode-area Er:ZBLAN fiber. Reliable self-starting mode-locking is achieved via the combination of nonlinear polarization rotation and a semiconductor saturable absorber. Stable mode-locked pulses with a pulse energy of 9.4 nJ and a pulse duration of 325 fs are generated. To the best of our knowledge, this is the highest pulse energy directly generated from a femtosecond mode-locked fluoride fiber laser (MLFFL) to date. The measured M2 factors are below 1.13, indicating a nearly diffraction-limited beam quality. Demonstration of this laser provides a feasible scheme for the pulse energy scaling of mid-infrared MLFFLs. Moreover, a peculiar multi-soliton mode-locking state is also observed, in which the time interval between the solitons varies irregularly from tens of picoseconds to several nanoseconds.
X-ray magnetic circular dichroism spectroscopy at the Fe L edges with a picosecond laser-driven plasma source
Authors: Borchert Martin , Engel Dieter , von Korff Schmising Clemens , Pfau Bastian , Eisebitt Stefan , Schick Daniel
Published: March 2023

Time-resolved x-ray magnetic circular dichroism (XMCD) enables a unique spectroscopic view on complex spin and charge dynamics in multi-elemental magnetic materials. So far, its application in the soft-x-ray range has been limited to synchrotron-radiation sources and free-electron lasers. By combining a laser-driven plasma source with a magnetic thin-film polarizer, we generate up to 30% circular polarization in the soft-x-ray regime, enabling the first XMCD spectroscopy at the Fe L edges in a laser laboratory, to our knowledge. Our approach can be readily adapted to other transition metal L and rare earth M absorption edges, and with a temporal resolution of <10ps, a wide range of ultrafast magnetization studies can be realized.
Evaluating public health strategies for climate adaptation: Challenges and opportunities from the climate ready states and cities initiative
Authors: Joseph Heather A. , Mallen Evan , McLaughlin Megan , Grossman Elena , Holmes Tisha Joseph , Locklear Autumn , Powell Emily , Thie Lauren , Uejio Christopher K. , Vacca Kristen , Williams Courtney , Bishop Tony , Jeffers Carol , Siegel Hannah , Austin Chelsea
Published: March 2023

Evaluation generates critical evidence about the effectiveness of health-focused climate adaptation, who receives what benefits, and how to improve program quality. However, using evaluation to improve climate adaptation outcomes with timeliness and context-specificity is uniquely challenging. The United States Centers for Disease Control and Prevention supports health departments to implement adaptation initiatives through the Climate-Ready States and Cities Initiative (CRSCI) grant and minimize negative health impacts of climate change via the Building Resilience Against Climate Effects (BRACE) framework, which includes evaluation. In this paper, we present current evaluation practice by describing the health-focused adaptation actions that were evaluated among CRSCI recipients, the evaluation approaches they used, and the barriers and enablers encountered. Using a mixed methods approach, we abstracted annual progress report and standardized performance measure data to characterize evaluation activities across 18 grant recipients using basic quantitative descriptive analysis. Through structured interviews with three grant recipients and standard team-based qualitative coding and analysis techniques, we developed qualitative case studies to explore evaluation barriers and enablers in richer context. Recipients reported 76 evaluations over the reporting period (2018–2021). Evaluated programs commonly addressed extreme weather (50.0%), followed by heat (27.6%). The most common purpose was to monitor implementation or improve delivery (57.9%). Case studies highlighted barriers to successful evaluation such as limited specialized evaluation expertise and staff time. Enablers included staff motivation to justify program expansion, strong relationships with community partners, and use of evaluation plans. Case studies revealed diverse strategies to seek input from stakeholders disproportionately impacted by climate change and to reduce health disparities. The experiences of CDC grant recipients provide an opportunity to better understand the barriers and enablers of climate and health evaluation practice and to identify practical strategies to expand the value of evaluation in this nascent field.