bluuebunny/crossref_metadata_2025 huggingface dataset:
Sustainable prefabricated buildings: a holistic approach
Authors: Tsikaloudaki Katerina , Theodosiou Theodore , Tsoka Stella , Chastas Panagiotis
Published: January 2022

Although modern prefabricated buildings may offer many advantages, such as a significant reduction in cost and time, improved quality and accuracy in manufacture, easy dismantle and reuse of its components, etc., they have not gained the attention they deserve in the construction market yet. In this paper, a holistic approach for the formation of prefabricated buildings of advanced performance is presented. Within this context, a new, innovative prefabricated building element is developed, designed to exhibit optimized structural, hygrothermal, energy, acoustic, fire and environmental performance. The improved properties of the building element are ensured by the proper configuration of the layers that compose it with respect to the design objectives; for example, in order to support the heat storage and the control of indoor temperatures, the integration of PCMs in the element's layers is investigated. Furthermore, in order to indicate the contribution of the new building element to the sustainability of the overall construction, the performance of a building formulated with the new element is analyzed in terms of energy and environmental behaviour. The new building element and construction system are expected to systemize the prefabricated element's production, leading eventually to the improvement of the building quality, as well as to the reduction of time and cost of building's erection. In parallel, the new certified and optimized building performance will increase the share of prefabricated buildings in the Mediterranean countries, where housing needs are gradually growing, while at the same time, energy efficient and environmentally friendly construction will be promoted.
The Walsh Transform of a Class of Boolean Functions
Authors: JIANG Niu , ZHUO Zepeng , CHEN Guolong , WANG Liting
Published: January 2022

The Walsh transform is an important tool to investigate cryptographic properties of Boolean functions. This paper is devoted to study the Walsh transform of a class of Boolean functions defined as [see formula in PDF], by making use of the known conclusions of Walsh transform and the properties of trace function, and the conclusion is obtained by generalizing an existing result.
Some Rank Formulas for the Yang-Baxter Matrix Equation AXA = XAX
Authors: DAI Lifang , LIANG Maolin , SHEN Yonghong
Published: January 2022

Let A be an arbitrary square matrix, then equation AXA =XAX with unknown X is called Yang-Baxter matrix equation. It is difficult to find all the solutions of this equation for any given A. In this paper, the relations between the matrices A and B are established via solving the associated rank optimization problem, where B =AXA = XAX, and some analytical formulas are derived, which may be useful for finding all the solutions and analyzing the structures of the solutions of the above Yang-Baxter matrix equation.
Online Latent Dirichlet Allocation Model Based on Sentiment Polarity Time Series
Authors: HUANG Bo , JU Jiaji , CHEN Huan , ZHU Yimin , LIU Jin , SHI Zhicai
Published: January 2022

The Product Sensitive Online Dirichlet Allocation model (PSOLDA) proposed in this paper mainly uses the sentiment polarity of topic words in the review text to improve the accuracy of topic evolution. First, we use Latent Dirichlet Allocation (LDA) to obtain the distribution of topic words in the current time window. Second, the word2vec word vector is used as auxiliary information to determine the sentiment polarity and obtain the sentiment polarity distribution of the current topic. Finally, the sentiment polarity changes of the topics in the previous and next time window are mapped to the sentiment factors, and the distribution of topic words in the next time window is controlled through them. The experimental results show that the PSOLDA model decreases the probability distribution by 0.160 1, while Online Twitter LDA only increases by 0.069 9. The topic evolution method that integrates the sentimental information of topic words proposed in this paper is better than the traditional model.
A Method to Deduce and Synthesize the Dafny Programs
Authors: WANG Changjing , DING Xilong , HE Jiangfei , CHEN Xi , HUANG Qing , LUO Haimei , ZUO Zhengkang
Published: January 2022

We propose a systematic method to deduce and synthesize the Dafny programs. First, the specification of problem is described in strict mathematical language. Then, the derivation process uses program specification transformation technology to perform equivalent transformation. Furthermore, Dafny program is synthesized through the obtained recursive relationship and loop invariants. Finally, the functional correctness of Dafny program is automatically verified by Dafny verifier or online tool. Through this method, we deduce and synthesize Dafny programs for many typical problems such as the cube sum problem, the minimum (or maximum) contiguous subarray problems, several searching problems, several sorting problems, and so on. Due to space limitation, we only illustrate the development process of Dafny programs for two typical problems: the minimum contiguous subarray problem and the new local bubble sorting problem. It proves that our method can effectively improve the correctness and reliability of Dafny program developed. What’s more, we demonstrate the potential of the deductive synthesis method by developing a new local bubble Sorting program.
Non-Blind Image Deblurring Method Using Shear High Order Total Variation Norm
Authors: LU Lixuan , ZHANG Tao
Published: January 2022

In this paper, we propose a shear high-order gradient (SHOG) operator by combining the shear operator and high-order gradient (HOG) operator. Compared with the HOG operator, the proposed SHOG operator can incorporate more directionality and detect more abundant edge information. Based on the SHOG operator, we extend the total variation (TV) norm to shear high-order total variation (SHOTV), and then propose a SHOTV deblurring model. We also study some properties of the SHOG operator, and show that the SHOG matrices are Block Circulant with Circulant Blocks (BCCB) when the shear angle is [see formula in PDF]. The proposed model is solved efficiently by the alternating direction method of multipliers (ADMM). Experimental results demonstrate that the proposed method outperforms some state-of-the-art non-blind deblurring methods in both objective and perceptual quality.
A Wire-Line Secure Communication System Based on CCFD Self-Interference Cancellation
Authors: LU Wenjian , LIU Sanjun , LAI Guohong
Published: January 2022

This paper presents a design scheme of wire-line telephone system using self-interference (SI) cancellation technology in co-frequency co-time full-duplex (CCFD) system to realize absolute secure communication at the physical layer. This scheme can hide the target signal by skillfully releasing the high-power artificial noise to the whole link at the receiving node, and then make use of the receiver’s knowledge of the SI signal to achieve high dB SI cancellation with the help of analog domain SI cancellation technology in CCFD domain, so that the signal-to-noise ratio (SNR) received by the eavesdropper at any position of the link is far lower than that of the legitimate receiver, so as to realize the absolutely secure communication in the sense of Wyner principle. This paper not only puts forward the specific design scheme of absolutely secure communication telephone, but also analyzes the calculation of security capacity under different eavesdropping positions, different SI cancellation capability and different system parameters according to Shannon theory.
Endoscopic characterization of colorectal neoplasia with different published classifications: comparative study involving CONECCT classification
Authors: Bonniaud Paul , Jacques Jérémie , Lambin Thomas , Gonzalez Jean-Michel , Dray Xavier , Coron Emmanuel , Leblanc Sarah , Chevaux Jean-Baptiste , Léger-Nguyen Florence , Hamel Benjamin , Lienhart Isabelle , Rivory Jérôme , Ponchon Thierry , Saurin Jean-Christophe , Monzy Frédéric , Legros Romain , Lépilliez Vincent , Subtil Fabien , Barret Maximilien , Pioche Mathieu
Published: January 2022

Background and study aims The aim of this study was to validate the COlorectal NEoplasia Classification to Choose the Treatment (CONECCT) classification that groups all published criteria (including covert signs of carcinoma) in a single table.

Patients and methods For this multicenter comparative study an expert endoscopist created an image library (n = 206 lesions; from hyperplastic to deep invasive cancers) with at least white light Imaging and chromoendoscopy images (virtual ± dye based). Lesions were resected/biopsied to assess histology. Participants characterized lesions using the Paris, Laterally Spreading Tumours, Kudo, Sano, NBI International Colorectal Endoscopic Classification (NICE), Workgroup serrAted polypS and Polyposis (WASP), and CONECCT classifications, and assessed the quality of images on a web-based platform. Krippendorff alpha and Cohen’s Kappa were used to assess interobserver and intra-observer agreement, respectively. Answers were cross-referenced with histology.

Results Eleven experts, 19 non-experts, and 10 gastroenterology fellows participated. The CONECCT classification had a higher interobserver agreement (Krippendorff alpha = 0.738) than for all the other classifications and increased with expertise and with quality of pictures. CONECCT classification had a higher intra-observer agreement than all other existing classifications except WASP (only describing Sessile Serrated Adenoma Polyp). Specificity of CONECCT IIA (89.2, 95 % CI [80.4;94.9]) to diagnose adenomas was higher than the NICE2 category (71.1, 95 % CI [60.1;80.5]). The sensitivity of Kudo Vi, Sano IIIa, NICE 2 and CONECCT IIC to detect adenocarcinoma were statistically different (P < 0.001): the highest sensitivities were for NICE 2 (84.2 %) and CONECCT IIC (78.9 %), and the lowest for Kudo Vi (31.6 %).

Conclusions The CONECCT classification currently offers the best interobserver and intra-observer agreement, including between experts and non-experts. CONECCT IIA is the best classification for excluding presence of adenocarcinoma in a colorectal lesion and CONECCT IIC offers the better compromise for diagnosing superficial adenocarcinoma.
Expertise in colonoscopy intubation does not predict diagnostic accuracy: a simulation-based study
Authors: Vilmann Andreas S. , Lachenmeier Christian , Svendsen Morten Bo S. , Soendergaard Bo , Park Yoon S. , Svendsen Lars Bo , Konge Lars
Published: January 2022

Background and study aims Studies have linked cecal intubation rate with adenoma detection rate; however, the direct association between technical performance during colonoscopy intubation and withdrawal has never been explored. Thus, it remains unclear whether gentle and efficient intubation predicts superior mucosal inspection. The aim of this study was to investigate the correlation between performance during intubation and withdrawal in a simulation-based setup.

Methods Twenty-four physicians with various experience in colonoscopy performed twice on the Endoscopy Training System (ETS). Intubation skills were evaluated by assessing tasks on the ETS related to intubation (scope manipulation and loop management) and use of a computerized assessment tool called the 3D-Colonoscopy Progression Score (3D-CoPS). Diagnostic accuracy was defined by the number of polyps found during the ETS task of mucosal inspection. Pearson’s correlations were calculated to explore associations between intubation skill and diagnostic accuracy.

Results The correlation analysis between 3D-CoPS and number of polyps found during mucosal inspection revealed a weak and insignificant correlation (0.157, P = 0.3). Likewise, an insignificant correlation was seen between ETS intubation and number of polyps found (0.149, P = 0.32).

Conclusions We found no evidence to support that technical performance during intubation is correlated with mucosal inspection performance in a simulation-based setting.
Identification of diverticular bleeding needs early colonoscopy rather than preparation
Authors: Mizuki Akira , Tatemichi Masayuki , Nakazawa Atsushi , Tsukada Nobuhiro , Nagata Hiroshi , Kanai Takanori
Published: January 2022

Background and study aims When patients present with acute colonic diverticulum bleeding (CDB), a colonoscopy is performed to identify stigmata of recent hemorrhage (SRH), but valuable time can be lost in bowel preparation. This study retrospectively examined groups of patients who either had a standard pre-colonoscopy regimen or no preparation.

Patients and methods This study compared data from 433 patients who either followed a lengthy regimen of bowel preparation (prepared group, 266 patients) or had no preparation (unprepared group, 60 patients). We compared the association between time (hours) between admission before starting a colonoscopy (TMS) and identification of SRH using a chi-square test.

Results In 48 of 60 cases (80.0 %) in the unprepared group, a total colonoscopy was performed and the time to identify SRH was decreased. The respective rates of SRH identification in the unprepared and prepared groups were 55.2 % (16/29) vs. 46.7 % (7/15) if the TMS was < 3 hours; 47.1 % (8/7) vs. 36.8 % (35/95) in 3 to 12 hours; 0 % (0/3) vs. 22.0% (13/59) in 12 to 18 hours; and 21.8 % (3/11) vs. 20.6% (42/204) in > 18 hours. There were no significant differences between the two groups. However, the SRH identification rates before and after 12 hours were 42.3 % (66/156) and 20.9 % (58/277) (P < 0.001).

Conclusions Our data suggest that the bowel preparation method before colonoscopy is an independent variable predicting success in identifying SRH among patients with CDB. Decreasing the time before colonoscopy to no more than 12 hours after admission played an important role in identifying SRH.
Impact of preoperative endoscopy for predicting treatment response and prognosis in patients with gastric cancer after neoadjuvant chemotherapy
Authors: Shoji Yoshiaki , Nunobe Souya , Nishie Naoki , Yagi Shusuke , Makuuchi Rie , Ida Satoshi , Kumagai Koshi , Ohashi Manabu , Ishiyama Akiyoshi , Yoshio Toshiyuki , Hirasawa Toshiaki , Fujisaki Junko , Sano Takeshi
Published: January 2022

Background and study aims Response evaluation criteria in solid tumors (RECIST) have been the gold standard to preoperatively predict treatment response and prognosis in patients with gastric cancer (GC) after neoadjuvant chemotherapy (NAC); however, methods for patients without evaluable lesions by RECIST are not yet confirmed. The aim of this study was to assess the utility of preoperative endoscopy for predicting treatment response and prognosis in patients with GC after NAC.

Patients and methods This retrospective study included 105 patients with initially resectable GC who underwent NAC followed by surgical treatment. Preoperative factors for predicting treatment response and survival outcomes were analyzed.

Results The number of patients classified as responders using preoperative endoscopic assessment, RECIST, and postoperative pathological evaluation were 25 (23.8 %), 28 (26.7 %), and 18 (17.1 %), respectively. Forty-three patients (41 %) were classified as non-targeted disease only, and their treatment responses were not evaluable by RECIST. Multivariate analysis identified endoscopic response as an independent preoperative factor to predict postoperative histological treatment response (odds ratio = 4.556, 95 % CI = 1.169–17.746, P = 0.029). Endoscopic treatment response was the only independent preoperative predictive factor for overall survival (OS) (hazard ratio = 0.419, 95 % confidence interval (CI) = 0.206–0.849, P = 0.016). Further, endoscopic treatment response was available for 33 patients (76.7 %) with non-targeted disease only, which showed significantly different OS between endoscopic responders (80.0 %) and non-responders (43.5 %) (P = 0.025).

Conclusions Endoscopic evaluation was an independent preoperative factor to predict treatment response and prognosis in patients with GC after NAC. Endoscopic assessment may be especially valuable for patients who could not be assessed by RECIST.
Facile Synthesis of Quinoxaline-2-thiol and Quinoxaline from α-Oxosulfines and o-Arylenediamines
Authors: Dong Jun , Huang Xingcai , Chen Youwei
Published: January 2022

A series of quinoxaline-2-thiols and quinoxalines were prepared in moderate to good yields from various phenacyl sulfoxides bearing 1-methyl-1H-tetrazole and o-arylenediamines. The proposed reaction mechanism involves generation of sulfines from the phenacyl sulfoxides bearing 1-methyl-1H-tetrazole through thermolysis elimination. Then, site-selective carbophilic addition of sulfines by o-arylenediamines, followed by elimination, intramolecular nucleophilic addition, and dehydration condensation. The current method provides a direct and simple strategy for the preparation of quinoxaline-2-thiols and quinoxalines.
Conjugated Nanohoops with Dibenzo[a,e]pentalenes as Nonalternant and Antiaromatic π-Systems
Authors: Esser Birgit , Wössner Jan S. , Hermann Mathias
Published: January 2022

Conjugated nanohoops are excellent as candidates for studying structure–property relationships, as optoelectronic materials, and as hosts for supramolecular chemistry. Whereas carbon nanohoops containing aromatics have been well studied, antiaromatic units had not been incorporated until our group recently did so, using dibenzo[a,e]pentalene (DBP). The nonalternant electronic character of the DBP units significantly influences the optoelectronic properties of such nanohoops. Here, we summarize our synthetic strategies toward DBP-containing nanohoops, together with their structural and electronic properties, chirality, and host–guest chemistry. We demonstrate how incorporating antiaromatic units leads to unique properties and opens new synthetic avenues, making such nanohoops attractive as potential electronic materials.

1 Introduction

2 Synthesis

3 Structural Properties

4 Electronic Properties

5 Chirality

6 Host–Guest Chemistry
Tuning the Electrochemical and Photophysical Properties of Osmium-Based Photoredox Catalysts
Authors: Bednářová Eva , Beck Logan R. , Rovis Tomislav , Goldschmid Samantha L. , Xie Katherine , Tay Nicholas E. S. , Ravetz Benjamin D. , Li Jun , Joe Candice L.
Published: January 2022

The use of low-energy deep-red (DR) and near-infrared (NIR) light to excite chromophores enables catalysis to ensue across barriers such as materials and tissues. Herein, we report the detailed photophysical characterization of a library of OsII polypyridyl photosensitizers that absorb low-energy light. By tuning ligand scaffold and electron density, we access a range of synthetically useful excited state energies and redox potentials.

1 Introduction

1.1 Scope

1.2 Measuring Ground-State Redox Potentials

1.3 Measuring Photophysical Properties

1.4 Synthesis of Osmium Complexes

2 Properties of Osmium Complexes

2.1 Redox Potentials of Os(L)2-Type Complexes

2.2 Redox Potentials of Os(L)3-Type Complexes

2.3 UV/Vis Absorption and Emission Spectroscopy

3 Conclusions
Postacute-Stroke Management Problems in Home Care Service: A Qualitative Single-Centered Study in Yogyakarta, Indonesia
Authors: Paryono Paryono , Ar Rochmah Mawaddah , Setyopranoto Ismail , Trisnantoro Laksono
Published: January 2022

Objective This study explores the postacute-stroke management problems, particularly for patients with total dependency (Barthel Index <20), in home care service of Dr. Sardjito Hospital (SH) from the hospital personnel's and caregiver's points of view.

Materials and Methods In-depth interviews with a semi-structured interview guide were conducted with hospital personnel and patients' caregivers based on the purposeful sampling. There were 10 hospital personnel that were interviewed: the director of medical service, head of home care unit, neurologists, general practitioners, nurses, and physiotherapist. There were eight caregivers who participated in the study.

Statistical Analysis Data from the interviews were analyzed using systematic text condensation using Nvivo 12 plus.

Results Our findings showed that all health personnel in SH agreed that home care service is a part of an integrated health care service for continuation of care. However, the preparedness by the hospital management is still lacking in infrastructures, such as standardized operational procedure, quality control, and financial system, as well as in terms of competent human resources and their welfare. In addition, the patient's family and caregiver are lacking in knowledge and independency to take care of the patients with the need of home care services' monitoring to deliver the expected home care for postacute-stroke's patient regularly.

Conclusion Home care service is an act of implementing hospital obligation to fulfill the patients' rights. An established hospital policy to ensure a comprehensive home care service delivery is necessary. The capability and welfare of the health care personnel should be put into account for the standardized human resources.
Regional synapse gain and loss accompany memory formation in larval zebrafish
Authors: Dempsey William P. , Du Zhuowei , Nadtochiy Anna , Smith Colton D. , Czajkowski Karl , Andreev Andrey , Robson Drew N. , Li Jennifer M. , Applebaum Serina , Truong Thai V. , Kesselman Carl , Fraser Scott E. , Arnold Don B.
Published: January 2022

Significance

Imaging of labeled excitatory synapses in the intact brain before and after classical conditioning permits a longitudinal analysis of changes that accompany associative memory formation. When applied to midlarval stage zebrafish, this approach reveals adjacent regions of synapse gain and loss in the lateral and medial pallium, respectively. Such major structural changes could account for the robust nature of memory formation from classical conditioning.
CD169+macrophages in lymph node and spleen critically depend on dual RANK and LTbetaR signaling
Authors: Camara Abdouramane , Lavanant Alice C. , Abe Jun , Desforges Henri Lee , Alexandre Yannick O. , Girardi Erika , Igamberdieva Zinaida , Asano Kenichi , Tanaka Masato , Hehlgans Thomas , Pfeffer Klaus , Pfeffer Sébastien , Mueller Scott N. , Stein Jens V. , Mueller Christopher G.
Published: January 2022

Significance

The CD169+macrophages that play an important role in the fight against infections and cancer are receptive to environmental signals for their differentiation. We show that lymph node and splenic CD169+macrophages require both LTβR and RANK signaling since the conditional deficiency of either receptor results in their disappearance. Using a reporter mouse, we observe RANKL expression by a splenic mesenchymal cell subset and show that it participates in CD169+macrophage differentiation. Their absence leads to a reduced viral capture and a greatly attenuated virus-specific CD8+T cell expansion. Thus, tight control mechanisms operate for the precise positioning of these macrophages at sites where numerous immune-stimulatory forces converge.
Targeted vaccination and the speed of SARS-CoV-2 adaptation
Authors: Gandon Sylvain , Lion Sébastien
Published: January 2022

Significance

The ongoing pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) raises an important question: who should we vaccinate first? Answering this question requires an analysis of both the short-term (epidemiological) and the long-term (evolutionary) consequences of targeted vaccination strategies. We analyze the speed of pathogen adaptation and the cumulative number of deaths in heterogeneous host populations to shed light on the effects of alternative vaccination strategies. This analysis shows that minimizing the speed of pathogen adaptation does not always minimize the number of deaths. This evaluation of both the epidemiological and evolutionary consequences of public health policies provides a practical tool to identify the best vaccination strategy.
The influence of socio-economic status, age, gender, and level of literacy on language attitudes
Authors: Ulysse Gerdine M. , Masaeed Khaled Al
Published: January 2022

This study investigated the relationship between socio-economic status, age, gender, and literacy level and Haitian Gonâviens‘ attitudes towards Haitian Creole or Kreyòl and French. Most studies that investigated language attitudes of Creolophones have found that they have negative attitudes towards Kreyòl. Nevertheless, previous studies often included participants who are affiliated with education such as students, teachers, and language policy makers, or those from higher social classes. The current study, however, utilized a language attitudes questionnaire to collect data from 78 adult informants from diverse backgrounds. These participants included 21 highly literate, 51 partially literate and 6 illiterate Haitians. Findings revealed that participants of higher socio-economic status have more positive attitudes towards French than those from lower socio-economic status. Results also showed that there is a tendency for age, gender, and literacy level to affect language attitudes. For instance, positive attitudes towards Kreyòl were found to be more prevalent among older participants than younger respondents. Similarly, male participants had more negative attitudes towards French than female informants. Moreover, respondents of lower literacy levels had more negative attitudes towards French than those who were highly literate.
Tourism Development in Algeria and the Horizon 2025 Plan
Authors: Azzaoui Imene , Carnicelli Sandro , Khodadadi Masood
Published: January 2022

Despite Algeria’s strategic geographical location as a portal to Africa from Europe and the continuous attempts to reform its tourism sector, this postcolonial country has failed to become a tourism hub in the Mediterranean area. In Algeria, the year 2008 witnessed the birth of a tourism development plan named ‘Horizon 2025’, projecting strategies and goals to be achieved by 2025. However, the plan did not achieve its expected results because of various socio-political and external issues such as the country’s recent political instability and the global Covid-19 pandemic. Surprisingly, Algeria’s domestic market has witnessed noticeable growth in the last 20 years, especially during the global pandemic. The present case study reflects on the development of the Horizon 2025 plan and its contribution to the rebranding of Algeria as a destination and the consequential outcomes that helped the growth of its domestic tourism market. Through the case study, we showcase the efforts made to build Algeria as an attractive destination and how Covid-19 challenged the plan’s forecasted goals while paving the way for the development and promotion of domestic tourism.

Information

The case study is the authors’ collaborative effort, adapted from the PhD thesis of Imene El Azzaoui

© Imene El Azzaoui 2022
MICROSCOPE mission scenario, ground segment and data processing
Authors: Rodrigues Manuel , Touboul Pierre , Métris Gilles , Bedouet Judicael , Bergé Joel , Carle Patrice , Chhun Ratana , Christophe Bruno , Foulon Bernard , Guidotti Pierre-Yves , Lala Stephanie , Robert Alain
Published: January 2022

Testing the weak equivalence principle to a precision of 10−15 requires a quantity of data that give enough confidence on the final result: ideally, the longer the measurement the better the rejection of the statistical noise. The science sessions had a duration of 120 orbits maximum and were regularly repeated and spaced out to accommodate operational constraints but also in order to repeat the experiment in different conditions and to allow time to calibrate the instrument. Several science sessions were performed over the 2.5 years duration of the experiment. This paper aims to describe how the data have been produced on the basis of a mission scenario and a data flow process, driven by a tradeoff between the science objectives and the operational constraints. The mission was led by the Centre National d’Etudes Spatiales (CNES) which provided the satellite, the launch and the ground operations. The ground segment was distributed between CNES and Office National d’Etudes et de Recherches Aérospatiales (ONERA). CNES provided the raw data through the Centre d’Expertise de Compensation de Traînée (CECT: drag-free expertise centre). The science was led by the Observatoire de la Côte d’Azur (OCA) and ONERA was in charge of the data process. The latter also provided the instrument and the Science Mission Centre of MICROSCOPE (CMSM).
On self organization: model for ionization wave propagation with targets of varying electrical properties
Authors: Martinez Luis , Dhruv Akash , Balaras Elias , Keidar Michael
Published: January 2022

This work presents a model for an atmospheric helium plasma interacting with normal and cancer cells. This interaction is simulated through the expansion and impingement of a gaseous jet onto targets with varying electrical permittivity. Simulation results show that for a plasma jet impinging onto two targets with different permittivity placed axis-symmetrically relative to the stagnation point of impingement, the jet is biased toward the target with lower permittivity when the target acts as a floating potential. This trend is reversed when the back surface of the target is grounded. In the case of a floating target, higher target permittivity yields a higher positive surface potential as the material experiences higher polarization in response to the net flux of electrons from the plasma onto the surface. Because of this higher surface potential, targets with higher permittivity generate a smaller electric field in the discharge column relative to materials with lower permittivity. When the back surface of the target is ground, the trend is reversed, with polarization occurring primarily on the back surface due to the response to the reservoir of positive charges introduced by ground. In the ground case, the material experiences more negative charging the front surface which induces a lower electric potential. As a result, the material with higher permittivity and a grounded back surface attracts plasma organization at the interface because of the higher local electric field. These numerical findings support experimental results presented by other researchers, which demonstrate selectivity of plasma jets toward some cancer cells more than others. The mechanism introduced here may help inform targeted treatment of specific cells, including those reported to be more resistant to plasma jets.
Experiment and numerical simulation of the combined effect of winding, cool-down, and screening current induced stresses in REBCO coils
Authors: Ueda Hiroshi , Maeda Hideaki , Suetomi Yu , Yanagisawa Yoshinori
Published: January 2022

This paper overviews the combined effects of winding, cool-down, and screening current-induced stresses in REBCO coils. First, a simulation method to model the circumferential stress modification effect due to the screening-current is overviewed. The simulation includes coil winding, cooling down, and coil charge up to the operating current. Second, we will compare the numerical simulation results with the experimental results. The numerical simulations for a dry coil and an epoxy impregnated coil agree well with the experimental results. Third, the enhanced circumferential stress did not degrade the performance of a dry winding REBCO coil, but the improved increased compressive stress buckled the coil structure. Finally, it is demonstrated that epoxy impregnation has beneficial effects in reducing the stress modification effect. However, the circumferential stress is enormously enhanced at the coil ends, sometimes resulting in degradation of the coil performance.
Equilibrium stochastic delay processes
Authors: Holubec Viktor , Ryabov Artem , Loos Sarah A M , Kroy Klaus
Published: January 2022

Stochastic processes with temporal delay play an important role in science and engineering whenever finite speeds of signal transmission and processing occur. However, an exact mathematical analysis of their dynamics and thermodynamics is available for linear models only. We introduce a class of stochastic delay processes with nonlinear time-local forces and linear time-delayed forces that obey fluctuation theorems and converge to a Boltzmann equilibrium at long times. From the point of view of control theory, such ‘equilibrium stochastic delay processes’ are stable and energetically passive, by construction. Computationally, they provide diverse exact constraints on general nonlinear stochastic delay problems and can, in various situations, serve as a starting point for their perturbative analysis. Physically, they admit an interpretation in terms of an underdamped Brownian particle that is either subjected to a time-local force in a non-Markovian thermal bath or to a delayed feedback force in a Markovian thermal bath. We illustrate these properties numerically for a setup familiar from feedback cooling and point out experimental implications.
Skynet’s New Observing Mode: The Campaign Manager
Authors: Dutton Dylan A. , Reichart Daniel E. , Haislip Joshua B. , Kouprianov Vladimir V. , Shaban Omar H. , Vasquez Soto Alan
Published: January 2022

Built in 2004, the Skynet robotic telescope network originally consisted of six 0.4 m telescopes located at the Cerro-Tololo Inter-American Observatory in the Chilean Andes. The network was designed to carry out simultaneous multi-wavelength observations of gamma-ray bursts (GRBs) when they are only tens of seconds old. To date, the network has been expanded to ≈20 telescopes, including a 20 m radio telescope, that span four continents and five countries. The Campaign Manager (CM) is a new observing mode that has been developed for Skynet. Available to all Skynet observers, the CM semi-autonomously and indefinitely scales and schedules exposures on the observer’s behalf while allowing for modification to scaling parameters in real time. The CM is useful for follow up to various transient phenomena including gravitational-wave events, GRB localizations, young supernovae, and eventually, sufficiently bright Argus Optical Array and Large Synoptic Survey Telescope events.
Prevention of electron cyclotron current drive triggering explosive bursts in reversed magnetic shear tokamak plasmas for disruption avoidance
Authors: Liu Tong , Wang Zheng-Xiong , Wei Lai , Wang Jialei
Published: January 2022

An explosive burst excited by a neoclassical tearing mode (NTM) is one of the possible candidates for disruptive terminations in reversed magnetic shear (RMS) tokamak plasmas. For the purpose of disruption avoidance, numerical investigations have been implemented on the prevention of explosive bursts triggered by the ill-advised application of electron cyclotron current drive (ECCD) in RMS configuration. Under the situation of controlling NTMs by ECCD in RMS tokamak plasmas, a threshold in electron cyclotron driven current has been found. Below the threshold, not only are the NTM islands not effectively suppressed but a deleterious explosive burst could also be triggered, which might contribute to major disruption to tokamak plasmas. In order to prevent this ECCD from triggering explosive bursts, three control strategies have been attempted in this work and two of them have been recognized to be effective. One is to apply differential poloidal plasma rotation in the proximity of outer rational surface during the ECCD control process; the other is to apply two ECCDs to control NTM islands on both rational surfaces at the same time. In the former strategy, the threshold is diminished due to the modification of the classical tearing mode index. In the latter strategy, the prevention is accomplished as a consequence of the reduction of the coupling strength between the two rational surfaces via the stabilization of inner islands. Moreover, the physical mechanism behind the excitation of the explosive burst and the control processes by different control strategies have all been discussed in detail.
High intensity proton beam impact at 440 GeV/c on Mo and Cu coated CfC/graphite and SiC/SiC absorbers for beam intercepting devices
Authors: Maestre J. , Bahamonde C. , Lamas Garcia I. , Kershaw K. , Biancacci N. , Busom J. , Frankl M.I. , Lechner A. , Kurtulus A. , Makimura S. , Nakazato N. , Pérez A.T. , Perillo-Marcone A. , Salvant B. , Seidenbinder R. , Teofili L. , Calviani M.
Published: January 2022

Beam Intercepting Devices (BIDs) are essential protection elements for the operation of the Large Hadron Collider (LHC) complex. The LHC internal beam dump (LHC Target Dump Injection or LHC TDI) is the main protection BID of the LHC injection system; its main function is to protect LHC equipment in the event of a malfunction of the injection kicker magnets during beam transfer from the SPS to the LHC. Several issues with the TDI were encountered during LHC operation, most of them due to outgassing from its core components induced by electron cloud effects, which led to limitations of the injector intensity and hence had an impact on LHC availability. The absorbing cores of the TDIs, and of beam intercepting devices in general, need to deal with high thermo-mechanical loads induced by the high intensity particle beams. In addition, devices such as the TDI — where the absorbing materials are installed close to the beam, are important contributors to the accelerator impedance budget. To reduce impedance, the absorbing materials that make up the core must be typically coated with high electrical conductivity metals. Beam impact testing of the coated absorbers is a crucial element of development work to ensure their correct operation.

In the work covered by this paper, the behaviour of several metal-coated absorber materials was investigated when exposed to high intensity and high energy proton beams in the HiRadMat facility at CERN. Different coating configurations based on copper and molybdenum, and absorbing materials such as isostatic graphite, Carbon Fibre Composite (CfC) and Silicon Carbide reinforced with Silicon Carbide fibres (SiC-SiC), were tested in the facility to assess the TDI's performance and to extract information for other BIDs using these materials. In addition to beam impact tests and an extensive Post Irradiation Examination (PIE) campaign to assess the performance of the coatings and the structural integrity of the substrates, extensive numerical simulations were carried out.
Modeling the systematic behavior at the micro and nano length scales
Authors: Quagliotti Danilo
Published: January 2022

The assessment of the systematic behavior based on frequentist statistics was analyzed in the context of micro/nano metrology. The proposed method is in agreement with the well-known GUM recommendations. The investigation assessed three different case studies with definition of model equations and establishment of the traceability. The systematic behavior was modeled in Sq roughness parameters and step height measurements obtained from different types of optical microscopes, and in comparison with a calibrated contact instrument. The sequence of case studies demonstrated the applicability of the method to micrographs when their elements are averaged. Moreover, a number of influence factors, which are typical causes of inaccuracy at the micro and nano length scales, were analyzed in relation to the correction of the systematic behavior, viz. the amount of repeated measurements, the time sequence of the acquired micrographs and the instrument-operator chain. The possibility of applying the method individually to the elements of the micrographs was instead proven not convenient and too onerous for the industry. Eventually, the method was also examined against the framework of the metrological characteristics defined in ISO 25 178-600 with hints on possible future developments.
Improvement in the microhardness and corrosion behaviour of Ti-14Mn biomedical alloy by cold working
Authors: Gouda M K , Salman Salah A , Ebied Saad
Published: January 2022

β-titanium alloys are essential in many applications, particularly biomedical applications. Ti-14Mn β-type alloy was produced using an electric arc furnace from raw alloying elements in an inert atmosphere. The alloy was homogenized at 1000 °C for 8 h to ensure the complete composition distribution, followed by solution treatment at 900 °C, then quenched in ice water. The alloy was subjected to cold deformation via cold rolling with different ratios: 10, 30, and 90%.

The phases change, microstructure, mechanical properties, and corrosion resistance of Ti-14Mn alloys were evaluated before and after cold rolling. The results showed that the β-phase is the only existed phase even after a high degree of deformation.

The microstructure shows a combination of twinning and slipping deformation mechanisms in the deformed alloy. Microhardness values indicated a linear increase equal to 30% by increasing the ratio of cold deformation due to the strain hardening effect. The corrosion resistance of Ti-14Mn alloy was doubled after 90% cold rolling.
Microstructure evolution, mechanical properties, and fractography of AA7068/ Si3N4 nanocomposite fabricated thorough ultrasonic-assisted stir casting advanced with bottom pouring technique
Authors: Kumar Ashish , Rana Ravindra Singh , Purohit Rajesh
Published: January 2022

Ceramic particulate embedded aluminum metal matrix nanocomposites (AMNCs) possess superior mechanical and surface properties and lightweight features. AMNCs are a suitable replacement of traditional material, i.e., steel, to make automotive parts. The current work deals with developing Si3N4 strengthened high strength AA7068 nanocomposites via novel ultrasonic-assisted stir casting method advanced with bottom pouring setup in the proportion of 0.5, 1.0, 1.5, and 2 wt.%. Planetary ball milling was performed on a mixture of AA7068 powder and Si3N4 (in the proportion of 3:1) before incorporation in aluminum alloy melt to avoid rejection of fine particles. Finite element scanning electron microscope (FESEM), Energy dispersive spectroscopy (EDS), X-Ray diffraction (XRD), and Elemental mapping techniques were used in the microstructural investigation. Significant grain refinement was observed with increasing reinforcing content, whereas agglomeration was found at higher weight %. Hardness, Tensile strength, ductility, porosity content, compressive strength, and impact energy were also examined of pure alloy and each composite. Improvement of 72.71%, 50.07%, and 27.41 % was noticed in hardness value, tensile strength, and compressive strength, respectively, at 1.5 weight % compared to base alloy because of various strengthening mechanisms. These properties are decreased at 2 wt.% due to severe agglomeration. In contrast, nanocomposite’s ductility and impact strength continuously decrease compared to monolithic AA7068. Fracture analysis shows the ductile and mixed failure mode in alloy and nanocomposites.
One Pill, Once a Day: Simplified Treatment Regimens and Retention in HIV Care
Authors: Bor Jacob , Kluberg Sheryl A , LaValley Michael P , Evans Denise , Hirasen Kamban , Maskew Mhairi , Long Lawrence , Fox Matthew P
Published: January 2022

Simplified drug regimens may improve retention in care for persons with chronic diseases. In April 2013, South Africa adopted a once-daily single-pill human immunodeficiency virus (HIV) treatment regimen as the standard of care, replacing a multiple-pill regimen. Because the regimens had similar biological efficacy, the shift to single-pill therapy offered a real-world test of the impact of simplified drug-delivery mechanisms on patient behavior. Using a quasi-experimental regression discontinuity design, we assessed retention in care among patients starting HIV treatment just before and just after the guideline change. The study included 4,484 patients starting treatment at a large public sector clinic in Johannesburg, South Africa. The share of patients prescribed a single-pill regimen increased by over 40 percentage points between March and April 2013. Initiating treatment after the policy change was associated with 11.7–percentage-points’ higher retention at 12 months (95% confidence interval: −2.2, 29.4). Findings were robust to different measures of retention, different bandwidths, and different statistical models. Patients starting treatment early in HIV infection—a key population in the test-and-treat era—experienced the greatest improvements in retention from single-pill regimens.
A Prospective Cohort Study of COVID-19 Vaccination, SARS-CoV-2 Infection, and Fertility
Authors: Wesselink Amelia K , Hatch Elizabeth E , Rothman Kenneth J , Wang Tanran R , Willis Mary D , Yland Jennifer , Crowe Holly M , Geller Ruth J , Willis Sydney K , Perkins Rebecca B , Regan Annette K , Levinson Jessica , Mikkelsen Ellen M , Wise Lauren A
Published: January 2022

Some reproductive-aged individuals remain unvaccinated against coronavirus disease 2019 (COVID-19) because of concerns about potential adverse effects on fertility. Using data from an internet-based preconception cohort study, we examined the associations of COVID-19 vaccination and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection with fertility among couples trying to conceive spontaneously. We enrolled 2,126 self-identified female participants aged 21–45 year residing in the United States or Canada during December 2020–September 2021 and followed them through November 2021. Participants completed questionnaires every 8 weeks on sociodemographics, lifestyle, medical factors, and partner information. We fit proportional probabilities regression models to estimate associations between self-reported COVID-19 vaccination and SARS-CoV-2 infection in both partners with fecundability (i.e., the per-cycle probability of conception), adjusting for potential confounders. COVID-19 vaccination was not appreciably associated with fecundability in either partner (female fecundability ratio (FR) = 1.08, 95% confidence interval (CI): 0.95, 1.23; male FR = 0.95, 95% CI: 0.83, 1.10). Female SARS-CoV-2 infection was not strongly associated with fecundability (FR = 1.07, 95% CI: 0.87, 1.31). Male infection was associated with a transient reduction in fecundability (for infection within 60 days, FR = 0.82, 95% CI: 0.47, 1.45; for infection after 60 days, FR = 1.16, 95% CI: 0.92, 1.47). These findings indicate that male SARS-CoV-2 infection may be associated with a short-term decline in fertility and that COVID-19 vaccination does not impair fertility in either partner.